Metal nutrition and transport in the process of symbiotic nitrogen fixation

Symbiotic nitrogen fixation (SNF) facilitated by the interaction between legumes and rhizobia is a well-documented and eco-friendly alternative to chemical nitrogen fertilizers. Host plants obtain fixed nitrogen from rhizobia by providing carbon and mineral nutrients. These mineral nutrients, which are mostly in the form of metal ions, are implicated in various stages of the SNF process. This review describes the functional roles played by metal ions in nodule formation and nitrogen fixation and specifically addresses their transport mechanisms and associated transporters within root nodules. Future research directions and potential strategies for enhancing SNF efficiency are also discussed.

[Comparison of safety and effectiveness of active migration technique and in situ lithotripsy technique in the treatment of 1-2 cm upper ureteral calculi by flexible ure-teroscopy]

OBJECTIVE

To compare the safety and effectiveness of active migration technique and in situ lithotripsy technique in the treatment of 1-2 cm upper ureteral calculi by retrograde flexible ureteroscopy.

METHODS

A total of 90 patients with 1-2 cm upper ureteral calculi treated in the urology department of Beijing Friendship Hospital from August 2018 to August 2020 were selected as the subjects. The patients were divided into two groups using random number table: 45 patients in group A were treated with in situ lithotripsy and 45 patients in group B were treated with active migration technique. The active migration technique was to reposition the stones in the renal calyces convenient for lithotripsy with the help of body position change, water flow scouring, laser impact or basket displacement, and then conduct laser lithotripsy and stone extraction. The data of the patients before and after operation were collected and statistically analyzed.

RESULTS

The age of the patients in group A was (51.6±14.1) years, including 34 males and 11 females. The stone diameter was (1.48±0.24) cm, and the stone density was (897.8±175.9) Hu. The stones were located on the left in 26 cases and on the right in 19 cases. There were 8 cases with no hydronephrosis, 20 cases with grade Ⅰ hydronephrosis, 11 cases with grade Ⅱ hydronephrosis, and 6 cases with grade Ⅲ hydronephrosis. The age of the patients in group B was (51.8±13.7) years, including 30 males and 15 females. The stone diameter was (1.52±0.22) cm, and the stone density was (964.6±214.2) Hu. The stones were located on the left in 22 cases and on the right in 23 cases. There were 10 cases with no hydronephrosis, 23 cases with grade Ⅰ hydronephrosis, 8 cases with grade Ⅱ hydronephrosis, and 4 cases with grade Ⅲ hydronephrosis. There was no significant diffe-rence in general parameters and stone indexes between the two groups. The operation time of group A was (67.1±16.9) min and the lithotripsy time was (38.0±13.2) min. The operation time of group B was (72.2±14.8) min and the lithotripsy time was (40.6±12.6) min. There was no significant difference between the two groups. Four weeks after operation, the stone-free rate in group A was 86.7%, and in group B was 97.8%. There was no significant difference between the two groups. In terms of complications, 25 cases of hematuria, 16 cases of pain, 10 cases of bladder spasm and 4 cases of mild fever occurred in group A. There were 22 cases of hematuria, 13 cases of pain, 12 cases of bladder spasm and 2 cases of mild fever in group B. There was no significant difference between the two groups.

CONCLUSION

Active migration technique is safe and effective in the treatment of 1-2 cm upper ureteral calculi.

[CD38 dictates cardiac damage through mitochondrial apoptotic pathway under hypoxic-ischemic conditions]

Objective: To explore the mechanism of CD38-mediated cardiac damage under hypoxic-ischemic (H/I) conditions. Methods: Twenty CD38(-/-) male mice (8-week-old) and 20 wild-type (WT) male C57BL/6J mice (8-week-old) were randomly selected to construct the model of approximately 25% of the total body surface area (TBSA) burn injury. The cardiomyocytes (CMs) were separated from neonatal mice (1day) to construct the H/I injury model. Ad-CD38 adenovirus was transfected into CD38(-)/- primary CMs to callback CD38 expression. Animal experiments were grouped into WT-control group, CD38(-/-)-control group, WT-burn group, and CD38(-/-)-burn group (10 mice in each group). Primary CMs were divided into 6 groups: WT-normoxia group, CD38(-/-)-normoxia group, CD38(-/-)+Ad-CD38-normoxia group, WT-H/I group, CD38(-/-)-H/I group, CD38(-/-)+Ad-CD38-H/I group. The release of lactic dehydrogenase (LDH) from CMs and the cell viability were measured to estimate the level of myocardial injury. Ultrastructure of cardiomyocytes was examined by electron microscope. CD38 protein level and mitochondrial apoptosis-related proteins were detected by Western blot. Flow cytometry was used to detect mitochondrial reactive oxygen species (MitoSOX) of CMs under H/I condition. Cardiac function of mice was detected by ultrasonic apparatus. Results: (1) Animal experiments: The expression level of cardiac CD38 in WT-burn group was significantly higher than that in sham group (P<0.001). The heart function of CD38(-/-)-burn group was obviously better than WT-burn group [ejection fraction (EF)%: (84.70±2.31)% vs (76.10±2.96)%, shortening fraction (FS)%: (48.90±5.00)% vs (38.10±2.80)%] (both P<0.001). (2) Cell experiments: The expression level of cardiac CD38 in WT CMs under H/I condition was significantly higher than that in WT CMs under normoxia condition (P<0.05). The level of LDH, apoptotic cell and MitoSOX in CD38(-/-)-H/I group were fewer than WT-H/I group and CD38(-/-)+Ad-CD38(-)H/I group [(11.2±3.0)% vs (18.2±3.4)% and (17.6±4.0)%, (13.0±2.8)% vs (23.1±4.9)% and (23.3±6.0)%, (162±11)% vs (228±18)% and (220±18)%] (all P<0.001). The levels of cleaved-caspase3, Cytochrome-C in CD38(-/-)-H/I group were significantly lower than those in WT-H/I group and CD38(-/-)+Ad-CD38-H/I group (P<0.001). The cell viability in CD38(-/-)-H/I group was higher than that in WT-H/I group and CD38(-/-)+Ad-CD38-H/I group (0.355±0.043 vs 0.280±0.051 and 0.291±0.024) (all P<0.05). Electron microscopy results showed that structure of mitochondria in CD38(-/-)-H/I group was better than in WT-H/I group and CD38(-/-)+Ad-CD38-H/I group. Conclusion: Overexpression of CD38 contributes to cardiac damage by stimulating mitochondrial apoptotic pathway.

Genome-wide analysis of differentially expressed lncRNA in sporadic parathyroid tumors

Diagnosis of parathyroid carcinoma on histological examination is challenging. Thousands of differentially expressed lncRNAs were identified on the microarray data between parathyroid cancer and adenoma samples. Four lncRNAs were significantly dysregulated in further validation. The "lncRNA score" calculated from these lncRNAs differentiated parathyroid carcinomas from adenomas. LncRNAs serve as biomarkers for parathyroid cancer diagnosis.

INTRODUCTION

Diagnosis of parathyroid carcinoma (PC) on histological examination is challenging. LncRNA profile study was conducted to find diagnostic biomarkers for PC.

METHODS

LncRNA arrays containing 91,007 lncRNAs as well as 29,857 mRNAs were used to assess parathyroid specimen (5 carcinomas and 6 adenomas). Bioinformatics analyses were also conducted to compare the microarray results between parathyroid carcinomas and adenomas (PAs). Differentially expressed lncRNAs of 11 PCs and 31 PAs were validated by real-time quantitative PCR.

RESULTS

On the microarray data between PC and PA samples (fold change ≥ 2, P < 0.05), 1809 differentially expressed lncRNAs and 1349 mRNAs also were identified. All carcinomas were clustered in the same group by clustering analysis using dysregulated lncRNAs or mRNAs. Four lncRNAs (LINC00959, lnc-FLT3-2:2, lnc-FEZF2-9:2, and lnc-RP11-1035H13.3.1-2:1) identified were significantly dysregulated in further RT-PCR validation. The global "lncRNA score" calculated from the lncRNAs above also differentiated parathyroid carcinomas from adenomas.

CONCLUSIONS

LncRNA profiling shows distinct differentially expressed lncRNAs in parathyroid neoplasm. They may play a key role in parathyroid cancer and serve as potential biomarkers to distinguish parathyroid cancers from parathyroid adenomas.

[In vitro study of the effect of human antigen R on lysosomal acidification during autophagy in mouse cardiomyocytes]

Objective: To investigate the effect of human antigen R on lysosomal acidification during autophagy in mouse cardiomyocytes cultured in vitro. Methods: The hearts of 20 C57BL/6 mice aged 1-2 days no matter male or female were isolated to culture primary cardiomyocytes which were used in the following experiments. (1) The cells were divided into 5 groups according to the random number table (the same grouping method below), i. e., normal control group and sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups. The cells in normal control group were routinely cultured for 54.0 h with Dulbecco's modified Eagle medium/nutrient mixture F12 (DMEM/F12) medium (the same regular culture condition below), and the cells in sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups were firstly regularly cultured for 53.5, 53.0, 51.0, 48.0 h and then cultured with replaced sugar-free serum-free medium for 0.5, 1.0, 3.0, and 6.0 h, respectively. The protein expressions of microtubule-associated protein 1 light chain 3 Ⅱ (LC3Ⅱ), autophagy-related protein 5, and adenosine triphosphatase V1 region E1 subunit (ATP6V1E1) were detected by Western blotting. (2) The cells were divided into normal control group and sugar-free serum-free 3.0 h group. The cells in corresponding groups were treated the same as those in experiment (1), and the cell lysosomal acidification level was observed and detected under a laser scanning confocal microscope. (3) Two batches of cells were grouped and treated the same as those in experiment (1). The protein expression of human antigen R in the whole protein of cells of one batch and its protein expression in the cytoplasm and nucleus protein of cells of the other batch were detected by Western blotting. (4) The cells were divided into normal control group, simple control small interfering RNA (siRNA) group, simple human antigen R-siRNA1 (HuR-siRNA1) group, simple HuR-siRNA2 group, sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, sugar-free serum-free+ HuR-siRNA1 group, and sugar-free serum-free+ HuR-siRNA2 group. After 48 hours of regular culture, the cells in simple control siRNA group and sugar-free serum-free+ control siRNA group were transfected with negative control siRNA for 6 h, the cells in simple HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA1 group were transfected with HuR-siRNA1 for 6 h, and the cells in simple HuR-siRNA2 group and sugar-free serum-free+ HuR-siRNA2 group were transfected with HuR-siRNA2 for 6 h. Hereafter, the cells in these 8 groups were continuously cultured for 48 h with regular conditon, and then the cells in normal control group and each simple siRNA-treated group were replaced with DMEM/F12 medium, the cells in the other groups were replaced with sugar-free serum-free medium, and they were cultured for 3 h. The protein expression of human antigen R in the whole protein of cells was detected by Western blotting. (5) Two batches of cells were divided into sugar-free serum-free+ control siRNA group and sugar-free serum-free+ HuR-siRNA1 group, and the cells in corresponding groups were treated the same as those in experiment (4). The distribution and expression of human antigen R in the cells of one batch were observed and detected by immunofluorescence method, and the lysosomal acidification level in the cells of the other batch was observed and detected under a laser scanning confocal microscope. (6) Three batches of cells were divided into sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, sugar-free serum-free+ HuR-siRNA1 group, and sugar-free serum-free+ HuR-siRNA2 group, and the cells in corresponding groups were treated the same as those in experiment (4). The protein expressions of cathepsin D in the whole protein of cells of one batch, human antigen R in the cytoplasm protein of cells of one batch, and ATP6V1E1 in the whole protein of cells of the other batch were detected by Western blotting. (7) The cells were divided into normal control group, sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, and sugar-free serum-free+ HuR-siRNA1 group, and the cells in corresponding groups were treated the same as those in experiment (4). The mRNA expression of ATP6V1E1 in cells was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The sample number of each experiment was 3. Data were processed with independent data t test, one-way analysis of variance, least significant difference t test, and Bonferroni correction. Results: (1) Compared with those of normal control group, the protein expressions of LC3Ⅱ and ATP6V1E1 in the whole protein of cells of sugar-free serum-free 1.0, 3.0, and 6.0 h groups were significantly increased (t=12.16, 4.05, 4.82, 11.64, 3.29, 8.37, P<0.05 or P<0.01). Compared with that of normal control group, the protein expression of autophagy-related protein 5 in the whole protein of cells of sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups was significantly increased (t=6.88, 10.56, 5.76, 9.91, P<0.05 or P<0.01). (2) Compared with 1.03±0.08 of normal control group, the lysosomal acidification level in the cells of sugar-free serum-free 3.0 group (2.92±0.30) was significantly increased (t=6.01, P<0.01). (3) There was no statistically significant difference in the overall comparison of protein expression of human antigen R in the whole protein of cells among the 5 groups (F=1.09, P>0.05). Compared with that of normal control group, the protein expression of human antigen R in the cytoplasm protein of cells was significantly increased in sugar-free serum-free 1.0, 3.0, and 6.0 h groups (t=43.05, 11.07, 5.39, P<0.05 or P<0.01), while the protein expression of human antigen R in the nucleus protein of cells was significantly decreased in sugar-free serum-free 3.0 and 6.0 h groups (t=11.18, 12.71, P<0.01). (4) Compared with that of simple control siRNA group, the protein expression of human antigen R in the whole protein of cells of simple HuR-siRNA1 group and simple HuR-siRNA2 group was significantly decreased (t=4.82, 4.44, P<0.05). Compared with that of sugar-free serum-free+ control siRNA group, the protein expression of human antigen R in the whole protein of cells of sugar-free serum-free+ HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA2 group was significantly decreased (t=4.39, 6.27, P<0.05). (5) Compared with those of sugar-free serum-free+ control siRNA group, the distribution of human antigen R in the cytoplasm of cells and its expression level were significantly decreased in sugar-free serum-free+ HuR-siRNA1 group (t=10.13, P<0.01). Compared with 1.00±0.06 of sugar-free serum-free+ control siRNA group, the lysosomal acidification level (0.73±0.06) in the cells of sugar-free serum-free+ HuR-siRNA1 group was significantly decreased (t=3.28, P<0.01). (6) Compared with those of sugar-free serum-free+ control siRNA group, the protein expressions of cathepsin D in the whole protein of cells, human antigen R in the cytoplasm protein of cells, and ATP6V1E1 in the whole protein of cells were significantly decreased in sugar-free serum-free+ HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA2 group (t=4.16, 3.99, 4.81, 5.07, 11.68, 12.97, P<0.05 or P<0.01). (7) Compared with that of normal control group, the mRNA expression of ATP6V1E1 in the cells of sugar-free serum-free 3.0 h group was significantly increased (t=5.51, P<0.05). Compared with that of sugar-free serum-free+ control siRNA group, the mRNA expression of ATP6V1E1 in the cells of sugar-free serum-free+ HuR-siRNA1 group was significantly decreased (t=5.97, P<0.05). Conclusions: After sugar-free serum-free treatment in vitro, the autophagy in mouse primary cardiomyocytes is activated, the lysosomal acidification is enhanced, and the expression of human antigen R in cytoplasm is increased. Human antigen R function is activated and involved in maintaining lysosomal acidification during autophagy in mouse cardiomyocytes.

The effect of postoperative radiotherapy on the survival of patients with resectable stage III-N2 non-small-cell lung cancer: a systematic review and meta-analysis

In the potentially resectable cases of stage III-N2 non-small-cell lung cancer (NSCLC), the optimal post-operative treatment regimen for these patients is uncertain and post-operative radiation therapy (PORT) with chemotherapy is typically recommended. Our aim was to reassess the data of PORT on overall survival (OS) and disease-free survival (DFS) in stage III-N2 NSCLC, in order to figure out whether PORT might lead to a moderate improvement in local control and survival besides resection and adjuvant chemotherapy. A comprehensive search strategy was performed in EMBASE, PubMed, and Cochrane Library for relevant studies comparing PORT combined with adjuvant chemotherapy or adjuvant chemotherapy alone on OS and DFS in resectable stage III-N2 NSCLC. Data were extracted to estimate the effects of PORT on OS and DFS. Eleven studies with 8,928 patients were included. This meta-analysis demonstrated a trend in improving OS associated with the use of PORT (HR=0.88; 95% CI, 0.76 to 1.03; p=0.11) and a significantly difference of effect on DFS associated with the use of PORT (HR=0.78; 95% CI, 0.66 to 0.92; p=0.003). In a subgroup analysis on Caucasian patients, there was a statistically significant benefit (HR=0.88; 95% CI, 0.81 to 0.96; p=0.003) on OS for PORT. Our findings demonstrate that in the postoperative treatment for patients with stage III-N2 NSCLC, PORT is associated with improved OS and leads to a significantly increased DFS.

[Influence of nicotinic acid adenine dinucleotide phosphate on autophagy in hypoxic cardiomyocytes of rats and its mechanism]

Objective: To investigate influence of nicotinic acid adenine dinucleotide phosphate (NAADP) on autophagy in hypoxic cardiomyocytes of rats and its mechanism. Methods: Five neonatal Sprague-Dawley rats were collected and sacrificed to harvest the hearts, and primary cardiomyocytes were separated for the following experiments. (1) Primary cardiomyocytes were collected and divided into normoxia group, hypoxia 9 h group, and hypoxia 9 h+ NAADP group according to random number table, with 5 wells in each group. Cells in normoxia group were cultured routinely in the constant temperature incubator at 37 ℃ for 9 hours. Cells in hypoxia 9 h group and hypoxia 9 h+ NAADP group were cultured in hypoxic incubator with volume fraction 94% nitrogen, 5% carbon dioxide, and 1% oxygen for 9 hours. Before hypoxia, cells in hypoxia 9 h+ NAADP group were dealt with final amount-of-substance concentration 10 μmol/L NAADP. Cell counting kit 8 was used to measure cell viability. (2) Primary cardiomyocytes were collected and divided into normoxia group, hypoxia 9 h group, hypoxia 9 h+ NAADP group, hypoxia 9 h+ tran-Ned-19 group, and hypoxia 9 h+ trans-Ned-19+ NAADP group according to the random number table, with 2 wells in each group. Cells in normoxia group were cultured routinely in the constant temperature incubator at 37 ℃ for 9 hours. And cells in the other 4 groups were cultured in hypoxic incubator as that in experiment (1) Before hypoxia, cells in hypoxia 9 h+ NAADP group were dealt with amount-of-substance concentration 10 μmol/L NAADP, cells in hypoxia 9 h+ tran-Ned-19 group were dealt with amount-of-substance concentration 1 μmol/L trans-Ned-19, and cells in hypoxia 9 h+ trans-Ned-19 + NAADP group were dealt with amount-of-substance concentration 10 μmol/L NAADP and 1 μmol/L trans-Ned-19. Protein expressions of microtubule associated protein 1 light chain 3-Ⅱ and P62 were detected by Western blotting. (3) Primary cardiomyocytes were collected and grouped as those in experiment (1). The lysosomal acidity was determined by immunofluorescence method. Data were processed with one-way analysis of variance and least-significant difference test. Results: (1) The cell viability in normoxia group was 1.114±0.024, which was significantly higher than 0.685±0.079 of cells in hypoxia 9 h group (P<0.01). The cell viability of hypoxia 9 h+ NAADP group was 0.886±0.061, which was obviously higher than that of cells in hypoxia 9 h group (P<0.05). (2) Expressions of microtubule-associated protein 1 light chain 3-Ⅱ and P62 of cells in hypoxia 9 h group were significantly higher than those of cells in normoxia group (P<0.01). Compared with those in hypoxia 9 h group, expression of P62 in hypoxia 9 h+ NAADP group was significantly decreased (P<0.01), while expression of microtubule-associated protein 1 light chain 3-Ⅱ did not change significantly (P>0.05). There were no significantly statistical difference in expressions of microtubule-associated protein 1 light chain 3-Ⅱ and P62 between hypoxia 9 h group and hypoxia 9 h+ trans-Ned-19 group (P>0.05). Compared with those of cells in hypoxia 9 h+ NAADP group, expression of P62 of cells in hypoxia 9 h+ trans-Ned-19+ NAADP group was obviously increased (P<0.01), while expression of microtubule-associated protein 1 light chain 3-Ⅱ did not change significantly (P>0.05). (3) The intensity of green fluorescence of cells in normoxia group was strong and co-localized well with red fluorescence, and internal environment of lysosome was with stronger acidity. The intensity of green fluorescence in cells of hypoxia 9 h group was significantly lower than that of cells in normoxia group, and acidity of internal environment of lysosome was weakened. The intensity of green fluorescence and acidity of internal environment of lysosome in hypoxia 9 h+ NAADP were significantly stronger than those of cells in hypoxia 9 h group, but significantly lower than those of cells in normoxia group. Conclusions: NAADP can improve myocardial cell viability through acidifying internal environment of lysosome of cardiomyocyte after hypoxia, promoting degradation of autophagosomes, reducing autophagic lysosomal accumulation, and repairing damaged autophagic flow.

[Role of hexokinase Ⅱ in the changes of autophagic flow in cardiomyocytes of mice with ischemia-hypoxia in vitro]

Objective: To investigate the role of hexokinase Ⅱ in the changes of autophagic flow in cardiomyocytes of mice with ischemia-hypoxia in vitro. Methods: The hearts of totally six male and female C57BL/6 mice aged from 1 to 2 days were isolated to culture primary cardiomyocytes which were used for the following experiments. (1) The cells were divided into 6 groups according to the random number table (the same grouping method below), i. e., normal control 3, 6, and 9 h groups and ischemia-hypoxia 3, 6, and 9 h groups, with 4 wells in each group. After being regularly cultured for 48 h with Dulbecco's modified Eagle medium/nutrient mixture F12 (DMEM/F12) medium (the same regular culture condition below), the cells in normal control 3, 6, and 9 h groups were cultured with replaced fresh DMEM/F12 medium for 3, 6, and 9 h, respectively, and the cells in ischemia-hypoxia 3, 6, and 9 h groups were cultured with replaced sugar-free serum-free medium in the low-oxygen incubator with a volume fraction of 1% oxygen and a volume fraction of 5% carbon dioxide at 37 ℃ (the same hypoxic culture condition below) for 3, 6, and 9 h, respectively. Cell viability was measured by the cell counting kit 8 (CCK-8) method. (2) The cells were grouped and treated the same as those in experiment (1), with 1 well in each group. Western blotting was used to detect the protein expressions of microtubule-associated protein 1 light chain 3 Ⅰ (LC3Ⅰ), LC3Ⅱ, p62, and hexokinase Ⅱ. (3) The cells were divided into normal control group, simple ischemia-hypoxia 9 h group, and ischemia-hypoxia 9 h+ 2-deoxyglucose (2-DG) group, with 4 wells in each group. After a regular culture for 48 h, the cells in normal control group were cultured with replaced fresh DMEM/F12 medium for 9 h; the cells in simple ischemia-hypoxia 9 h group were replaced with sugar-free serum-free medium, and the cells in ischemia-hypoxia 9 h+ 2-DG group were replaced with sugar-free serum-free medium in which 2-DG was dissolved in a concentration of 10 mmol/L (20 μmol), and then they were cultured with hypoxia for 9 h. Cell viability was measured by CCK-8 method. (4) The cells were grouped and treated the same as those in experiment (3), with 1 well in each group. Western blotting was used to detect the protein expressions of LC3Ⅰ, LC3Ⅱ, and p62. (5) The cells were grouped and treated the same as those in experiment (3), with 2 wells in each group. Transmission electron microscope was used to observe autophagosomes/autolysosomes in cardiomyocytes. (6) The cells were divided into normal control group, simple ischemia-hypoxia 9 h group, ischemia-hypoxia 9 h+ hexosinase Ⅱ small interfering RNA1 (HK-ⅡsiRNA1) group, and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group, with 4 wells in each group. The cells in normal control group and simple ischemia-hypoxia 9 h group were regularly cultured for 48 h, and the cells in ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were respectively transfected with 200 nmol/L HK-ⅡsiRNA1 and HK-ⅡsiRNA2 and then also cultured for 48 h. The cells in normal control group were cultured with replaced fresh DMEM/F12 medium for 9 h, and the cells in simple ischemia-hypoxia 9 h group, ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group, and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were cultured with replaced sugar-free serum-free medium and hypoxia for 9 h. Cell viability was measured by CCK-8 method. (7) The cells were grouped and treated the same as those in experiment (6), with 1 well in each group. Western blotting was used to detect the protein expressions of LC3Ⅰ, LC3Ⅱ, p62, and hexokinase Ⅱ. Except for experiment (5), each experiment was repeated 3 times. Data were processed with one-way analysis of variance and lest significant difference t test, and Bonferroni correction. Results: (1) The viabilities of cardiomyocytes in ischemia-hypoxia 3, 6, and 9 h groups were 0.450±0.022, 0.385±0.010, and 0.335±0.015, respectively, which were significantly lower than 0.662±0.026, 0.656±0.028, and 0.661±0.021 of the corresponding normal control 3, 6, and 9 h groups, respectively (t=6.21, 9.12, 12.48, P<0.01). (2) Compared with those of corresponding normal control 3, 6, and 9 h groups, the LC3Ⅱ/Ⅰ ratio and protein expressions of p62 and hexokinase Ⅱ in cardiomyocytes of ischemia-hypoxia 3, 6, and 9 h groups were significantly increased (t(3 h)=16.15, 10.99, 5.30, t(6 h)=6.79, 10.42, 9.42, t(9 h)=15.76, 16.51, 7.20, P<0.05 or P<0.01). (3) The viability of cardiomyocytes in simple ischemia-hypoxia 9 h group was 0.353±0.022, which was significantly lower than 0.673±0.027 of normal control group (t=9.29, P<0.01). The viability of cardiomyocytes in ischemia-hypoxia 9 h+ 2-DG group was 0.472±0.025, which was significantly higher than that of simple ischemia-hypoxia 9 h group (t=3.60, P<0.05). (4) Compared with those of normal control group, the LC3Ⅱ/Ⅰ ratio and protein expression of p62 in cardiomyocytes of simple ischemia-hypoxia 9 h group were significantly increased (t=9.45, 8.40, P<0.01). Compared with those of simple ischemia-hypoxia 9 h group, the LC3Ⅱ/Ⅰratio and protein expression of p62 in cardiomyocytes of ischemia-hypoxia 9 h+ 2-DG group were significantly decreased (t=4.39, 4.74, P<0.05). (5) In cardiomyocytes of normal control group, only single autophagosome/autolysosome with bilayer membrane structure was observed. Compared with that of normal control group, the number of autophagosome/autolysosome with bilayer membrane structure in cardiomyocytes of simple ischemia-hypoxia 9 h group was increased significantly. Compared with that of simple ischemia-hypoxia 9 h group, the number of autophagosome/autolysosome with bilayer membrane structure in cardiomyocytes of ischemia-hypoxia 9 h+ 2-DG group was significantly decreased. (6) The viability of cardiomyocytes in simple ischemia-hypoxia 9 h group was 0.358±0.023, which was significantly lower than 0.673±0.026 in normal control group (t=9.12, P<0.01). The viabilities of cardiomyocytes in ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were 0.487±0.027 and 0.493±0.022, respectively, which were significantly higher than the viability in simple ischemia-hypoxia 9 h group (t=3.63, 4.28, P<0.05). (7) Compared with those of normal control group, the LC3Ⅱ/Ⅰratio and protein expressions of p62 and hexokinase Ⅱ in cardiomyocytes of simple ischemia-hypoxia 9 h group were significantly increased (t=6.08, 6.31, 4.83, P<0.05 or P<0.01). Compared with those of simple ischemia-hypoxia 9 h group, the LC3Ⅱ/Ⅰ ratio and protein expressions of p62 and hexokinase Ⅱ in cardiomyocytes of ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were significantly decreased (t=5.10, 7.76, 15.33, 4.17, 8.42, 12.11, P<0.05 or P<0.01). Conclusions: Ischemia-hypoxia upregulates the expression level of hexokinase Ⅱ protein in mouse cardiomyocytes cultured in vitro, which decreases the viability of cardiomyocytes by impairing autophagic flow. To inhibit the activity of hexokinase Ⅱ or its expression can alleviate the ischemia-hypoxia damage of cardiomyocytes.

[Multicenter epidemiological investigation of hospitalized elderly, young and middle-aged patients with severe burn]

Objective: To compare and analyze the epidemiological characteristics of hospitalized elderly, young and middle-aged patients with severe burn in recent years, so as to provide reference for the prevention and treatment of elderly patients with severe burn. Methods: Relying on the entry system of epidemiological case data and biological sample of severe burn from multicenter in clinic, medical records of patients with severe burn, aged above 18, hospitalized in 8 burn wards from January 2012 to December 2015 were collected. Six hundred and fifteen patients who were more than 18 years old and less than or equal to 65 years old were included in young and middle-aged group (YM). Eighty-two patients aged more than 65 years old were included in elderly group (E). Data of age, gender, residence, education level, cause of injury, location of injury, season of injury, total burn area, occurrence and area of full-thickness burn injury, wound site, inhalation injury incidence and severity, post burn admission time, proportion of delayed resuscitation, proportion of escharectomy or tangential excision and skin grafting, preinjury systemic disease, system complication during hospitalization, length of hospital stay, outcome of treatment, and reason of abandoning treatment of patients were analyzed. Data were processed with chi-square test and Mann-Whitney U test. The odds ratios of preinjury systemic disease, system complication during hospitalization, and adverse outcome of patients in group YM were compared with those in group E. Results: (1) The majority of patients in the two groups were male, but the proportion of male patients in group YM was higher. There was statistically significant difference in gender distribution of patients between the two groups (χ(2)=18.727, P<0.001). The majority of patients in the two groups were from rural areas, but the proportion of rural patients in group E was higher. There was statistically significant difference in residence distribution of patients between the two groups (χ(2)=9.306, P=0.002). Patients in group YM mainly had secondary education, while patients in group E mainly had primary education. There was statistically significant difference in distribution of education level of patients between the two groups (χ(2)=146.797, P<0.001). (2) The most common causes of injury of patients in the two groups were both flame, but the proportion of patients with flame burn injury in group E was higher. There was statistically significant difference in distribution of cause of injury of patients between the two groups (χ(2)=25.063, P<0.001). The main locations of injury of patients in groups YM and E were respectively public place and private residence. There was statistically significant difference in location distribution of injury of patients between the two groups (χ(2)=46.313, P<0.001). The main seasons of injury of patients in groups YM and E were respectively summer and winter. There was statistically significant difference in season distribution of patients between the two groups (χ(2)=23.143, P<0.001). There was statistically significant difference in distribution of total burn area of patients between the two groups (χ(2)=25.799, P=0.002). The occurrences of full-thickness burn injury of patients in the two groups were similar (χ(2)=2.685, P=0.101), while there was statistically significant difference in area of full-thickness burn injury of patients between the two groups (χ(2)=26.702, P=0.002). There was no statistically significant difference in distribution of wound site of patients between the two groups (χ(2)=3.954, P=0.785). There were no statistically significant differences in incidence and severity distribution of inhalation injury of patients between the two groups (with χ(2) values respectively 0.425 and 0.672, P values above 0.05). (3) There was statistically significant difference in distribution of admission time of patients between the two groups (χ(2)=6.632, P=0.036), but there was no statistically significant difference in proportion of delayed resuscitation of patients between the two groups (χ(2)=1.261, P=0.261). The proportion of escharectomy or tangential excision and skin grafting of patients in group YM was 72.0% (443/615), which was significantly higher than 35.4% (29/82) of group E (χ(2)=44.498, P<0.001). The incidence of preinjury systemic disease of patients in group YM was 13.2% (81/615), which was significantly lower than 61.0% (50/82) of group E (χ(2)=108.337, P<0.001). The risk of preinjury systemic disease of patients in group E was 10.30 times of that of patients in group YM [with 95% confidence interval (CI) of 6.24-17.01, P<0.001]. During hospitalization, 59.8% (49/82) of patients in group E suffered from system complications, which was significantly higher than 36.6% (225/615) of group YM (χ(2)=16.282, P<0.001). The risk of system complication of patients in group E was 2.57 times of patients in group YM (with 95% CI of 1.61-4.12, P<0.001). The length of hospital stay of patients in group E was significantly shorter than that of group YM (U=36 735, P<0.001). There was statistically significant difference in treatment outcome of patients between the two groups (χ(2)=106.251, P<0.001). The risk of adverse outcome of patients in group E was 7.52 times of group YM (with 95% CI of 4.40-12.88, χ(2)=67.709, P<0.001). The proportion of abandoning treatment of patients in group E was significantly higher than that of group YM (χ(2)=150.670, P<0.001). The risk of abandoning treatment of patients in group E was 15.86 times of that of group YM (with 95% CI of 9.36-26.88, P<0.001). There was no statistically significant difference in distribution of reason of abandoning treatment of patients between the two groups (χ(2)=4.178, P=0.243). Conclusions: There were significant differences in the epidemiological characteristics of patients in groups E and YM. In elderly burn patients, the proportion of rural population was higher and the education level was lower. Flame burn was common and burns mostly occurred in private residences and in winter. The total burn area was slightly lower but the area of full-thickness burn injury was larger. The length of hospital stay was shorter and the proportion of surgical treatment was lower. The incidences of preinjury systemic disease and system complication during hospitalization were higher, and therefore the risks of adverse outcome and abandoning treatment were higher.

High-transmission polarization-dependent active plasmonic color filters

Plasmonic color filters, exhibiting great promise as an alternative for existing colorant-based filters, often only output one fixed color. Developing active color filters with controllable color output will lead to more compact color filter-based devices. In this paper, we present an approach to achieve active color filtering with a polarization-dependent plasmonic structural color filter, which comprises arrays of asymmetric cross-shaped nanoapertures in an ultrathin film of silver. A systematical study for aperture size, array period, and the thickness of silver film dependences of color filter properties is carried out, and strategies for polarization-dependent color filter designing are generated. A polarization-dependent and high tunability of color can be achieved by selecting the appropriate nanostructure parameters, which imply many potential applications.

Structure and dynamical properties of liquid Ni64Zr36 and Ni65Hf35 alloys: an ab initio molecular dynamics study

Ab initio molecular dynamics simulations are performed to investigate the atomic structures and dynamics of Ni₆₄Zr₃₆ and Ni₆₅Hf₃₅ metallic liquids in a temperature range of 1400-2500 K. Calculated results are in good agreement with recently reported high temperature experimental data. Local atomic structures are analyzed and compared for Ni₆₄Zr₃₆ and Ni₆₅Hf₃₅ metallic liquids in terms of average bond length, coordination number, Honey-Andersen index, Bond-orientation order, spatial correlation and Voronoi tessellation methods. It is found that Zr-Zr bonds have larger average length of 3.32 Å than 3.22 Å for Hf-Hf bonds, causing sluggish diffusion in Ni₆₅Hf₃₅ liquids. Zr and Hf atom-centered clusters with higher coordination numbers are inclined to aggregate with high-coordinated clusters, while Ni atom-centered clusters with lower coordination numbers prefer to avoiding to be the nearest neighbor with each other. Temperature dependent diffusion coefficients reveal the decoupled diffusion in both liquids, which are related with different spatial correlations for Ni- and Zr- (or Hf-) centered clusters.

Structural Signature of β-Relaxation in La-Based Metallic Glasses

The secondary β-relaxation is an intrinsic feature in glassy materials. However, its structural origin is still not well understood. Here we report that the β-relaxations in La₅₀Al₁₅Ni₃₅ and La₅₀Al₁₅Cu₃₅ metallic glasses (MGs) mainly depend on the vibration of small Ni and Cu atoms in local cages. By using advanced synchrotron X-ray techniques and theoretical calculations, we elucidate that the tricapped-trigonal-prism-like polyhedra with more large La atoms in shells favor the local vibration of center Ni atoms, leading to the pronounced β-relaxation event. In contrast, the in-cage vibration of Cu atoms is somehow suppressed by the appearance of more shell Cu atoms. Nevertheless, they could easily diffuse out of the cages compared with Ni, thus triggering the onset of α-relaxation. This work provides a pathway to understand the different structural relaxation behaviors in MGs and other disordered materials from their local atomic packing and dynamics points of view.

[Effects of decline of pH value on cardiomyocyte viability of rats and the mechanism]

Objective: To explore the effects of decline of pH value on cardiomyocyte viability of rats, and to analyze the possible mechanism. Methods: Hearts of five newborn Sprague-Dawley rats were isolated, and then primary cardiomyocytes were cultured and used in the following experiments. (1) The primary cardiomyocytes were divided into pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups according to the random number table, with 4 wells in each group. After being routinely cultured for 48 h (similarly hereinafter), cells in pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, and pH 6.0+ 6 h groups were cultured with pH 7.4, pH 7.0, pH 6.5, and pH 6.0 DMEM-F12 medium (similarly hereinafter), respectively, and then they were cultured for 6 h. Cells in pH 6.5+ 1 h and pH 6.5+ 3 h groups were cultured with pH 6.5 medium, and then they were cultured for 1 h and 3 h, respectively. Viability of cells was detected by methyl-thiazolyl-tetrazolium (MTT) method. (2) The primary cardiomyocytes were divided into pH 7.4, pH 6.5, and pH 6.5+ taxol groups according to the random number table, with 2 wells in each group. Cells in pH 7.4 group were cultured with pH 7.4 medium, while cells in pH 6.5 and pH 6.5+ taxol groups were cultured with pH 6.5 medium. Cells in pH 6.5+ taxol group were added with taxol of a final molarity of 0.2 μmol/L in addition, and then they were cultured for 6 h. Morphology and density of microtubule of cells was detected by immunofluorescence assay. (3) The primary cardiomyocytes were grouped and treated as in experiment (2), with 2 wells in each group. The expressions of polymerized microtubulin and free microtubulin were determined with Western blotting. (4) The primary cardiomyocytes were grouped and treated as in experiment (2), with 4 wells in each group. Viability of cells after treated with taxol was detected by MTT method. Data were processed with one-way analysis of variance and LSD-t test. Results: (1) The viability of cells in pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups were 1.00±0.08, 0.90±0.08, 0.85±0.06, 0.83±0.04, 0.91±0.10, and 0.89±0.10, respectively. Compared with that in pH 7.4+ 6 h group, viability of cells in pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups were all decreased in different degrees (t=2.476, 4.002, 4.996, 2.168, 2.400, P<0.05). (2) Microtubules of cells in pH 7.4 group were radially distributed around the nucleus with clear tubular structure. Compared with that in pH 7.4 group, the skeleton of microtubules of cells in pH 6.5 group was obviously damaged, with broken structure of microtubule and reduced density. Compared with that in pH 6.5 group, the damage degree of microtubules of cells in pH 6.5+ taxol group was obviously alleviated, and the structure of microtubules basically returned to normal. (3) Compared with that in pH 7.4 group, the expression of free microtubulin of cells in pH 6.5 group was significantly increased (t=3.030, P<0.05), while the expression of polymerized microtubulin of cells was significantly decreased (t=8.604, P<0.05). Compared with that in pH 6.5 group, the expression of free microtubulin of cells in pH 6.5+ taxol group was significantly decreased (t=4.559, P<0.05), while the expression of polymerized microtubulin of cells was significantly increased (t=5.472, P<0.05). (4) Viability of cells in pH 7.4, pH 6.5, and pH 6.5+ taxol groups were 1.00±0.10, 0.83±0.04, and 0.93±0.10, respectively. Compared with that in pH 7.4 group, the viability of cells in pH 6.5 group was obviously declined (t=4.412, P<0.05). Compared with that in pH 6.5 group, the viability of cells in pH 6.5+ taxol group was obviously increased (t=2.461, P<0.05). Conclusions: The decline of pH value reduces the viability of cardiomyocytes of rats through destroying the skeleton of microtubule. Stabilizing microtubule skeleton can significantly reduce acidic treatment-induced damage and ameliorate cardiomyocyte viability.

Temperature dependent structural evolution in liquid Ag50Ga50 alloy

The temperature dependence of atomic structural evolution in liquid Ag₅₀Ga₅₀ alloy has been studied using an in situ high energy x-ray diffraction (XRD) experiment combined with first-principles molecular dynamics (FPMD) simulations. The experimental data show a reversible structural crossover at the temperature of about 1050 K. Changes in both electrical resistivity and absolute thermoelectric power at about 1100 K strongly support the XRD results. Additionally, FPMD simulations reveal the abnormal temperature dependent behavior of partial coordination number and atomic diffusivity at about 1200 K, elucidating that the partition experimentally observed changes in structure and properties could be linked with the repartition between Ag and Ga atoms in the liquid at around 1050-1200 K. This finding will trigger more studies on the structural evolution of noble-polyvalent metals in particular and metallic liquids in general.

Size effect on atomic structure in low-dimensional Cu-Zr amorphous systems

The size effect on atomic structure of a Cu₆₄Zr₃₆ amorphous system, including zero-dimensional small-size amorphous particles (SSAPs) and two-dimensional small-size amorphous films (SSAFs) together with bulk sample was investigated by molecular dynamics simulations. We revealed that sample size strongly affects local atomic structure in both Cu₆₄Zr₃₆ SSAPs and SSAFs, which are composed of core and shell (surface) components. Compared with core component, the shell component of SSAPs has lower average coordination number and average bond length, higher degree of ordering, and lower packing density due to the segregation of Cu atoms on the shell of Cu₆₄Zr₃₆ SSAPs. These atomic structure differences in SSAPs with various sizes result in different glass transition temperatures, in which the glass transition temperature for the shell component is found to be 577 K, which is much lower than 910 K for the core component. We further extended the size effect on the structure and glasses transition temperature to Cu₆₄Zr₃₆ SSAFs, and revealed that the T_g decreases when SSAFs becomes thinner due to the following factors: different dynamic motion (mean square displacement), different density of core and surface and Cu segregation on the surface of SSAFs. The obtained results here are different from the results for the size effect on atomic structure of nanometer-sized crystalline metallic alloys.

[Effects of change in the activity of vacuolar adenosine triphosphatase of myocardial lysosome on myocardial damage in rats after severe burn and its mechanism]

Objective: To explore the effects of change of activity of vacuolar adenosine triphosphatase (V-ATPase) of myocardial lysosome on myocardial damage in rats after severe burn and its mechanism. Methods: The myocardial lysosomes were extracted from the hearts of 12 SD rats with ultra-high speed gradient density centrifugation, then Western blotting and transmission electron microscope observation were conducted for identification. One hundred and twenty rats were divided into pure burn group, ATP group, normal control group, and bafilomycin group according to the random number table, with 30 rats in each group. Rats in pure burn group and ATP group were inflicted with 40% TBSA full-thickness scald on the back. Immediately after injury, rats in pure burn group were intraperitoneally injected with lactated Ringer's solution in 4 mL·%TBSA(-1)·kg(-1,) and rats in ATP group were intraperitoneally injected with ATP in 0.4 mg/kg at 12 h before burn, immediately after burn, and 12 h after burn. Rats in normal control group did not receive any treatment, and rats in bafilomycin group were intraperitoneally injected with bafilomycin A1 in 0.3 mg/kg at the same time points as those of ATP group. At 24 h after burn, 30 rats from each group were collected for determining activity of V-ATPase of myocardial lysosome with coupled-enzyme assay and the expression of myocardium autophagy-related proteins microtubule-associated protein 1 light chain 3 (LC3) and P62 by Western blotting. Left ventricular arterial blood was collected to detect the content of 5 items of myocardial enzyme spectrum and cardiac troponin T (cTnT). Data were processed with one-way analysis of variance and t test. Results: (1) After identification, both the expression level of lysosome-related membrane protein 1 and purity of lysosome in the sample were high, and the structure of lysosome was intact. (2) At 24 h after burn, the activity values of V-ATPase of myocardial lysosome in rats of pure burn group, ATP group, normal control group, and bafilomycin group were (2.03±0.67), (3.01±0.58), (4.29±0.26), and (1.83±0.52) μmol·mg(-1)·h(-1,) respectively. The activity value of V-ATPase of myocardial lysosome in rats of pure burn group was significantly lower than the values in ATP group and normal control group (with t values respectively 3.14 and 8.87, P values below 0.01). The activity values of V-ATPase of rats in normal control group were significantly higher than those in bafilomycin group (t=11.87, P<0.01). At 24 h after burn, the expressions of myocardial LC3 and P62 in pure burn group were significantly higher than those in ATP group and normal control group (with t values from 3.73 to 5.88, P values below 0.01). The expressions of myocardial LC3 and P62 in normal control group were significantly lower than those in bafilomycin group (with t values respectively 2.64 and 3.07, P<0.05 or P<0.01). At 24 h after burn, the content of 5 items of myocardial enzyme spectrum and cTnT in pure burn group was significantly higher than that in ATP group and normal control group (with t values from 3.24 to 16.72, P values below 0.01). The content of 5 items of myocardial enzyme spectrum and cTnT in normal control group was significantly lower than that in bafilomycin group (with t values from 2.39 to 10. 70, P values below 0.01). Conclusions: The activity of V-ATPase of myocardial lysosome decreased in rats after severe burn, which can result in myocardial damage by inhibiting myocardial autophagy flux.

[Mechanism of protective effects of tumor necrosis factor receptor associated protein 1 on hypoxic cardiomyocytes of rats]

Objective: To investigate the mechanism of protective effects of tumor necrosis factor receptor associated protein 1 (TRAP1) on hypoxic cardiomyocytes of rats. Methods: Primary cultured cardiomyocytes were obtained from neonatal Sprague-Dawley rats (aged 1 to 3 days) and then used in the following experiments. (1) Cells were divided into group TRAP1 and control group according to the random number table (the same grouping method below), and then the total protein of cells was extracted. Total protein of cells in group TRAP1 was added with mouse anti-rat TRAP1 monoclonal antibody, while that in control group was added with the same type of IgG from mouse. Co-immunoprecipitation and protein mass spectrography analysis were used to determine the possible proteins interacted with TRAP1. (2) Cells were divided into normoxia blank control group (NBC), normoxia+ TRAP1 interference control group (NTIC), normoxia+ TRAP1 interference group (NTI), normoxia+ TRAP1 over-expression control group (NTOC), and normoxia+ TRAP1 over-expression group (NTO), with 1 well in each group. Cells in group NBC were routinely cultured, while cells in the latter four groups were respectively added with TRAP1 RNA interference empty virus vector, TRAP1 RNA interference adenovirus vector, TRAP1 over-expression empty virus vector, and TRAP1 over-expression adenovirus vector. Another batch of cells were divided into group NBC, hypoxic blank control group (HBC), hypoxic+ TRAP1 interference control group (HTIC), hypoxic+ TRAP1 interference group (HTI), hypoxic+ TRAP1 over-expression control group (HTOC), and hypoxic+ TRAP1 over-expression group (HTO), with 1 well in each group. Cells in hypoxic groups were under hypoxic condition for 6 hours after being treated as those in the corresponding normoxia groups, respectively. The mRNA expression of cytochrome c oxidase subunit Ⅱ (COXⅡ) of cells in each group was detected by real time fluorescent quantitive reverse transcription polymerase chain reaction. Experiments were repeated for three times. (3) Cells were divided into group NBC, group HBC, group HTOC, group HTO, hypoxic+ TRAP1 over-expression+ COXⅡinterference control group (HTOCIC), and hypoxic+ TRAP1 over-expression+ COXⅡinterference group (HTOCI), with 3 wells in each group. Cells in the previous 4 groups were treated as those in experiment (2). Cells in group HTOCIC and HTOCI were respectively transfected with COXⅡ RNA interference empty virus vector and COXⅡ RNA interference adenovirus vector, and then both added with TRAP1 over-expression adenovirus vector. The proliferation activity of cells was determined by cell counting kit 8 and microplate reader, and the ratio of death cells was measured by propidium lodide and Hoechst 33342 staining. Another batch of cells were divided into group NBC, group HBC, group HTIC, group HTI, hypoxic+ TRAP1 interference+ COXⅡover-expression control group (HTICOC), and hypoxic+ TRAP1 interference+ COXⅡ over-expression group (HTICO), with 3 wells in each group. Cells in the previous 4 groups were treated as those in experiment (2). Cells in group HTICOC and HTICO were both transfected with TRAP1 RNA interference adenovirus vector, and then respectively added with COXⅡ over-expression empty virus vector and COXⅡ over-expression adenovirus vector. The proliferation activity of cells and the ratio of death cells were detected as before. Experiments were repeated for three times. Data were processed with one-way analysis of variance and LSD test. Results: (1) The expression of TRAP1 was found in cells of group TRAP1, while that was not found in cells of control group. The possible proteins interacted with TRAP1 were keratin, COXⅡ, and an unknown protein with predicted molecular weight 13×10³. (2) Compared with that in group NBC, the mRNA expression of COXⅡof cells had no significant change in group NTIC and group NTOC (with P values above 0.05), but significantly decreased in group NTI (P<0.01), and significantly increased in group NTO (P<0.01). Compared with that in group NBC, the mRNA expression of COXⅡof cells in group HBC was significantly decreased (P<0.01). Compared with that in group HBC, the mRNA expression of COXⅡof cells had no significant change in group HTIC and group HTOC (with P values above 0.05), but significantly decreased in group HTI (P<0.01), and significantly increased in group HTO (P<0.01). (3) The proliferation activity of cells in group NBC, group HBC, group HTOC, group HTO, group HTOCIC, and group HTOCI was respectively 0.498±0.022, 0.303±0.018, 0.313±0.032, 0.456±0.031, 0.448±0.034, and 0.335±0.026, and the ratios of death cells in above groups were respectively (4.7±1.5)%, (24.7±3.1)%, (26.0±2.7)%, (13.3±2.5)%, (12.7±2.1)%, and (21.0±1.7)%. Compared with those in group NBC, the proliferation activity of cells in HBC was decreased, while the ratio of death cells was increased (with P values below 0.01). Compared with those in group HBC, the proliferation activity of cells and the ratio of death cells in group HTOC had no significant change (with P values above 0.05), while the proliferation activity of cells was increased and the ratio of death cells was decreased in group HTO (with P values below 0.01). Compared with those in group HTO, the proliferation activity of cells and the ratio of death cells in group HTOCIC had no significant change (with P values above 0.05), while the proliferation activity of cells was decreased and the ratio of death cells was increased in group HTOCI (with P values below 0.01). (4) The proliferation activity of cells in group NBC, group HBC, group HTIC, group HTI, group HTICOC, and group HTICO was respectively 0.444±0.025, 0.275±0.016, 0.283±0.021, 0.150±0.009, 0.135±0.011, and 0.237±0.017, and the ratios of death cells in above groups were respectively (3.7±0.6)%, (21.0±2.7)%, (20.3±3.1)%, (31.7±2.5)%, (33.3±3.2)%, and (19.3±1.5)%. Compared with those in group HBC, the proliferation activity of cells and the ratio of death cells in group HTIC had no significant change (with P values above 0.05). Compared with those in group HBC and group HTIC, the proliferation activity of cells was decreased and the ratio of death cells was significantly increased in group HTI (with P values below 0.01). Compared with those in group HTI, the proliferation activity of cells and the ratio of death cells in group HTICOC had no significant change (with P values above 0.05), while the proliferation activity of cells was increased and the ratio of death cells was significantly decreased in group HTICO (with P values below 0.01). Conclusions: TRAP1 can up-regulate the expression of COXⅡ mRNA, and COXⅡ is one of the downstream effector molecules that TRAP1 mediates its protective effects on hypoxic cardiomyocytes.

Comparative study of crystallization process in metallic melts using ab initio molecular dynamics simulations

The crystallization process of liquid metals is studied using ab initio molecular dynamics simulations. The evolution of short-range order during quenching in Pb and Zn liquids is compared with body-centered cubic (bcc) Nb and V, and hexagonal closed-packed (hcp) Mg. We found that the fraction and type of the short-range order depends on the system under consideration, in which the icosahedral symmetry seems to dominate in the body-centered cubic metals. Although the local atomic structures in stable liquids are similar, liquid hcp-like Zn, bcc-like Nb and V can be deeply supercooled far below its melting point before crystallization while the supercooled temperature range in liquid Pb is limited. Further investigations into the nucleation process reveal the process of polymorph selection. In the body-centered cubic systems, the polymorph selection occurs in the supercooled state before the nucleation is initiated, while in the closed-packed systems it starts at the time of onset of crystallization. Atoms with bcc-like lattices in all studied supercooled liquids are always detected before the polymorph selection. It is also found that the bond orientational ordering is strongly correlated with the crystallization process in supercooled Zn and Pb liquids.

Plasmonic reflection color filters with metallic random nanostructures

We develop reflective color filters with randomly distributed nanodisks and nanoholes fabricated with hydrogen silsesquioxane and Ag films on silicon substrate. They exhibit high resolution, angle-independence and easily up-scalable fabrication, which are the most important factors for color filters for industrial applications. We uncover the underlying mechanism after systematically analyzing the localized surface plasmon polariton coupling in the electric-field distribution. The agreement of the experimental results with those from the simulation indicates that tunable colors across the visible spectrum can be obtained by simply varying the diameter of the nanodisks, promoting their applications.

Composition- and temperature-dependent liquid structures in Al-Cu alloys: an ab initio molecular dynamics and x-ray diffraction study

The composition- and temperature-dependent liquid structures in eight Al_rich-Cu binary alloys (from hypoeutectic Al₉₃Cu₇ to hypereutectic Al₇₀Cu₃₀) have been experimentally and computationally studied by x-ray diffraction (XRD) experiments and ab initio molecular dynamics (AIMD) simulations. The remarkable agreements of structure factors for all liquid Al_rich-Cu alloys obtained from high-temperature high-energy XRD measurements and AIMD simulations have been achieved, which consolidates the analyses of structural evolutions in Al_rich-Cu liquids during the cooling processing by AIMD simulations. The heat capacity of liquid Al_rich-Cu alloys continuously increases and presents no abnormal peak when reducing the temperature, which differs from the reported prediction for 55-atom Al_rich-Cu nanoliquids. The diffusivities of Al and Cu undergo an increasing deviation from Arrhenius behavior by tuning Cu concentration from 7 to 30 atomic percentages, correlated to the local ordering in these liquids by means of coordination number, bond-angle distribution, Honeycutt-Andersen index, bond-orientational order and Voronoi tessellation analyses. Upon cooling, the microstructure of the liquid Al_rich-Cu alloys inclines to form Al₂Cu crystal-like local atomic ordering, especially in the hypereutectic liquids. The favorable short-range ordering between Cu and Al atoms could cause the non-Arrhenius diffusion behavior.

[Multicenter epidemiological investigation of hospitalized children with severe burn]

Objective: To analyze the epidemiological characteristics of hospitalized children with severe burn from several regions in China during 3 years, so as to provide evidence for prevention of burns in children. Methods: Relying on the entry system of epidemiology data and biological sample of severe burn from multicenter in clinic, medical records of children with severe burn, aged 18 and under, hospitalized in 6 burn wards from February 2012 to February 2015 were collected. The children were divided into 5 age brackets: less than or equal to 1 year old, more than 1 year old and less than or equal to 3 years old, more than 3 years old and less than or equal to 6 years old, more than 6 years old and less than or equal to 12 years old, more than 12 years old and less than or equal to 18 years old. Meanwhile the children were divided into rural and urban children according to their residences. Data of gender and residence of children in the 5 age brackets, cause of injury, location of injury, total burn area, wound site, inhalation injury and combined injury, and source of hospitalization expenses of children in the 5 age brackets and two types of residence, and outcome and length of hospital stay of the children were analyzed. The cause of injury of children in different location of injury was analyzed. In addition, they were divided into 2 age brackets: less than or equal to 6 years old and more than 6 years old and less than or equal to 18 years old, and then incidences of hand and foot burn injury were compared. Data were processed with chi-square test, and the correlation between age and total burn area was processed with Spearman correlation analysis. Results: Four hundred and forty out of 1 106 inpatients with severe burn were children, accounting for 39.8% who were included in the system. (1) The majority of children were male (270, 61.4%). The number of children more than 1 year old and less than or equal to 3 years old ranked the first (222, 50.5%) in the 5 age brackets. The ratio of children from rural areas to that from urban areas was 2.9∶1.0. There were no statistically significant differences in both gender and residence of children among the 5 age brackets (with χ² values respectively 7.649 and 9.399, P values above 0.05). (2) Scald was the most common cause of burn. There was statistically significant difference in injury cause of children among the 5 age brackets (χ²=136.307, P<0.001). There was no statistically significant difference in injury cause of children among the two types of residence (χ²=5.164, P>0.05). (3) Private house was the most common location of injury. There was statistically significant difference in location of injury of children among the 5 age brackets (χ²=124.930, P<0.001). There was no statistically significant difference in location of injury of children among the two types of residence (χ²=3.364, P>0.05). There was statistically significant difference in injury cause of children in different location of injury (χ²=118.284, P<0.001). (4) Most of children were with total burn areas from 10% to 39% total body surface area. There was statistically significant difference in total burn area of children among the 5 age brackets (χ²=103.568, P<0.001). There was positive correlation between age and total burn area (r=0.177, P<0.001). There was no statistically significant difference in total burn area of children among the two types of residence (χ²=16.213, P>0.05). (5) Trunk, lower extremity, and upper extremity were the most common wound sites, respectively. There was statistically significant difference in wound site of children among the 5 age brackets (χ²=45.674, P=0.019). There was statistically significant difference in incidence of hand and foot burn between children less than or equal to 6 years old and children more than 6 years old and less than or equal to 18 years old (with χ² values respectively 29.188 and 14.612, P values below 0.01). There was no statistically significant difference in wound site of children among the two types of residence (χ²=8.515, P>0.05). (6) Twenty-seven children suffered inhalation injury. The main age bracket was more than 12 years old and less than or equal to 18 years old (8 children). The main residence was rural area (18 children). The main cause of inhalation injury was flame burn (23 children). Nine children suffered combined injury, among which the children more than 12 years old and less than or equal to 18 years old accounted for the highest ratio (5 children), and the urban children accounted for higher ratio (5 children). (7) Among the 437 children, most of their hospitalization expenses were at their own expense. There was statistically significant difference in the source of hospitalization expenses of children among the 5 age brackets (χ²=17.917, P=0.001). There was no statistically significant difference in the source of hospitalization expenses of children among the two types of residence (χ²=0.749, P>0.05). (8) Among the 437 children, 34 children abandoned treatment and were discharged from hospital, attributed to lack of funding. Seventy-eight children were discharged with a better health condition and 347 were cured. The condition of 6 children worsened and 6 children died. Mean length of hospital stay was 28.6 days for all the children, and 8.8 days for the deteriorated and dead children. Conclusions: Children were the major group of patients with severe burn in China. Male children less than or equal to 6 years old were common with scald as the major cause of injury, private house as the major location of injury, and trunk, lower and upper extremity as the most common wound sites, their own expenses as the major source of hospitalization expenses. There were statistically significant differences in cause of injury, location of injury, total burn area, wound site, and hospitalization expenses source of children among the 5 age brackets.

Genetic effect of an A/G polymorphism in the HSP70 gene on thermotolerance in chicken

Studying thermotolerance is important for the prevention of thermostress in chickens. This study aimed to analyze the effect of mutations in the heat shock protein 70 (HSP70) gene on chicken thermotolerance. The C.-69A>G SNP in the 5'-flanking region of the HSP70 gene was genotyped in Lingshan and White Recessive Rock (WRR) chickens. Association of this SNP with thermotolerance traits revealed it to be significantly associated with CD4+/CD8+, and potentially associated with heterophil-to-lymphocyte ratio in WRR chickens exposed to thermoneutral temperature (15°C). Online prediction detected a putative myeloid zinc finger protein 1 binding factor in the C.-69A>G mutation. Under acute thermostress, mRNA levels of HSP70 in individuals with different C.-69A>G genotypes varied in the heart, leg muscle, and liver tissues. The HSP70 protein was expressed at higher levels in individuals with the GG genotype than in those with the AA genotype. In heart and liver, protein expression of HSP70 in individuals with the GG genotype was significantly higher than in those with the AA genotype. In leg muscle, protein expression was higher in birds with the GG genotype than in those with the AA and AG genotypes. Luciferase activity of the GG genotype was significantly higher than that of the AA genotype, suggesting that the C.-69A>G SNP regulates HSP70 gene expression. These results indicate that the C.-69A>G SNP in the 5'-flanking region of the HSP70 gene might affect chicken thermotolerance and that the GG genotype might be advantageous for the prevention of thermostress.

Polarization-independent plasmonic subtractive color filtering in ultrathin Ag nanodisks with high transmission

We demonstrate a TE/TM polarization-independent plasmonic subtractive color filtering scheme employing ultrathin two-dimensional Ag nanodisks. These TE/TM polarization-independent subtractive color filters exhibit small feature sizes (below 200 nm) and high transmission up to 70% in the visible spectral region, superior to previously reported plasmonic color filters. Simulated optical transmission spectra and colors are in good agreement with experimental results. The color-filtering behaviors strongly depend on thickness and period of nanodisks. Underlying mechanisms are also discussed in detail.

Role of endothelial TRPV4 channels in vascular actions of the endocannabinoid, 2-arachidonoylglycerol

BACKGROUND AND PURPOSE

Metabolites of the endocannabinoid, 2-arachidonoylglycerol (2-AG) have been postulated to act as endogenous activators of TRPV4, a Ca(2+) -permeable cation channel that plays a critical role in endothelium-dependent relaxation. However, it is unclear if TRPV4 contributes to the vascular actions of 2-AG.

EXPERIMENTAL APPROACH

Isometric tension recording of rat small mesenteric arteries and aortae were used to assess the effect of 2-AG and the synthetic TRPV4 activator, GSK1016790A (GSK) on vascular reactivity. Changes in intracellular Ca(2+) concentration and single-channel currents were measured in TRPV4-expressing human coronary endothelial cells.

KEY RESULTS

In mesenteric arteries, endothelium-dependent relaxation to both 2-AG and GSK was attenuated by structurally distinct TRPV4 antagonists, HC067047, RN1734 and ruthenium red. The responses were inhibited by KCa inhibitors (apamin + charybdotoxin) and a gap junction inhibitor (18α-glycyrrhetinic acid). In contrast to GSK, 2-AG elicited considerable relaxation independently of the endothelium or TRPV4. Inhibition of 2-AG metabolism via monoacylglycerol lipase and COX (by MAFP and indomethacin) caused potentiation, while cytochrome P450 and lipoxygenase inhibitors had no effect on 2-AG relaxation. In coronary endothelial cells, 2-AG (with and without MAFP) induced HC067047-sensitive increases in intracellular Ca(2+) concentration. 2-AG also increased TRPV4 channel opening in inside-out patches. However, in aortae, GSK induced a relaxation sensitive to HC067047 and ruthenium red, whereas 2-AG induced contractions.

CONCLUSIONS AND IMPLICATIONS

These data suggest that 2-AG can directly activate endothelial TRPV4, which partly contributes to the relaxant response to 2-AG. However, the functional role of TRPV4 is highly dependent on the vascular region.

Design of ultrafast laser-driven microactuator based on photoacoustic mechanism

In this work, an ultrafast laser-driven microactuator based on the photoacoustic mechanism was proposed with large amplitude and high response frequency. The microactuator was fabricated by LIGA technology. The displacement of the microactuator could be up to 11 μm at resonance state when the repeat frequency was around 14 kHz using a nanosecond pulse laser. Theoretical model was set up and the calculated results agree reasonably well with the experimental data. The microactuator based on the photoacoustic mechanism provides a more efficient actuation method.

Effect of relative nanohole position on colour purity of ultrathin plasmonic subtractive colour filters

Plasmonic subtractive color filters through patterning periodic nanostructures on ultrathin Ag films deposited on a glass substrate, exhibiting good durability, simple fabrication, and flexible color tunability, have attracted considerable attention due to their tremendous potential applications. While previous studies have mainly focused on their extraordinary physical mechanisms, color purity, which is another key parameter for high quality imaging applications, has been much less investigated. In this work, we demonstrate that the relative position of nanoholes patterned on ultrathin Ag films can largely affect the color purity of plasmonic subtractive color filters. The calculated results agree reasonably well with the experimental data, revealing that the purity of subtractive colors can be improved by changing the nanohole arrays from square lattice to triangular lattice without reducing transmission at visible frequencies. In addition, underlying mechanisms are clarified by systematically analyzing the dominant valley in transmission spectra.

Dynamic properties of a metal photo-thermal micro-actuator

This work presents the design, modeling, simulation, and characterization of a metal bent-beam photo-thermal micro-actuator. The mechanism of actuation is based on the thermal expansion of the micro-actuator which is irradiated by a laser, achieving noncontact control of the power supply. Models for micro-actuators were established and finite-element simulations were carried out to investigate the effects of various parameters on actuation properties. It is found that the thermal expansion coefficient, thermal conductivity, and the geometry size largely affected actuation behavior whereas heat capacity, density, and Young's modulus did not. Experiments demonstrated the dynamic properties of a Ni micro-actuator fabricated via LIGA technology with 1100/30/100 μm (long/wide/thick) arms. The tip displacement of the micro-actuator could achieve up to 42 μm driven by a laser beam (1064 nm wavelength, 1.2 W power, and a driving frequency of 1 HZ). It is found that the tip displacement decreases with increasing laser driving frequency. For 8 Hz driving frequency, 17 μm (peak-valley value) can be still reached, which is large enough for the application as micro-electro-mechanical systems. Metal photo-thermal micro actuators have advantages such as large displacement, simple structure, and large temperature tolerance, and therefore they will be promising in the fields of micro/nanotechnology.

Evolution of atomic structure in Al75Cu25 liquid from experimental and ab initio molecular dynamics simulation studies

X-ray diffraction and electrostatic levitation measurements, together with the ab initio molecular dynamics simulation of liquid Al(75)Cu(25) alloy have been performed from 800 to 1600 K. Experimental and ab initio molecular dynamics simulation results match well with each other. No abnormal changes were experimentally detected in the specific heat capacity over total hemispheric emissivity and density curves in the studied temperature range for a bulk liquid Al(75)Cu(25) alloy measured by the electrostatic levitation technique. The structure factors gained by the ab initio molecular dynamics simulation precisely coincide with the experimental data. The atomic structure analyzed by the Honeycutt-Andersen index and Voronoi tessellation methods shows that icosahedral-like atomic clusters prevail in the liquid Al(75)Cu(25) alloy and the atomic clusters evolve continuously. All results obtained here suggest that no liquid-liquid transition appears in the bulk liquid Al(75)Cu(25) alloy in the studied temperature range.

The crystallization process of liquid vanadium studied by ab initio molecular dynamics

We present a study of the crystallization process in liquid vanadium over a temperature range from 3000 K down to 1500 K using ab initio molecular dynamics simulations. Short-range order evolution during solidification is studied using various structural analysis methods. We show that the icosahedral-like short-range order is detected in the stable liquid phase and grows upon supercooling. The system undergoes a first-order phase transition (from a liquid to a solid state) at a temperature of about 1600 K. The crystal nucleation process is further studied using the time-temperature transformation mechanism by annealing the system at 1650 K. The nucleation is examined using bond-orientational order and density fluctuation analysis. Our finding is that various precursors appear in the region of high bond-orientational order with the majority having body-centered cubic (bcc)-like symmetry. This bcc-like region grows on annealing via thermal fluctuations. Our results reveal that the bond-orientational order precedes the density fluctuation, and is the main driving factor for nucleation.

Atomic structure evolution during solidification of liquid niobium from ab initio molecular dynamics simulations

Atomic structure transitions of liquid niobium during solidification, at different temperatures from 3200 to 1500 K, were studied by using ab initio molecular dynamics simulations. The local atomic structure variations with temperature are investigated by using the pair-correlation function, the structure factor, the bond-angle distribution function, the Honeycutt-Anderson index, Voronoi tessellation and the cluster alignment methods. Our results clearly show that, upon quenching, the icosahedral short-range order dominates in the stable liquid and supercooled liquid states before the system transforms to crystalline body-center cubic phase at a temperature of about 1830 K.

Nutrient density and slaughter age have differential effects on carcase performance, muscle and meat quality in fast and slow growing broiler genotypes

1. A 2 × 2 factorial design was used to investigate the differences in carcase, muscle and meat characteristics between fast and slow growing genotypes fed on low nutrient (LND) or high nutrient diets (HND) at their respective slaughter ages. 2. The birds were randomly assigned to treatments with 5 replicates of 145 birds for Wens Yellow-Feathered Chicken (WYFC, 5·75 birds/m(2)) or 115 birds for White Recessive Rock Chicken (WRRC, 7·25 birds/m(2)), according to the commercial recommendations for the two breeds and were fed on HND or LND. Birds were slaughtered at 63 d and 105 d of age. 3. The results showed WRRC had higher carcase yield and meat yield than that of WYFC, lower fat content, higher moisture content and lower cooking loss. The meat from WRRC was less tender and contained lower levels of polyunsaturated fatty acids (PUFA). 4. Birds fed on HND had higher breast meat yield, myofiber area and protein content in the breast muscle and lower fat content than birds fed on LND. The thigh muscle of birds fed on HND had higher levels of PUFA. Age had a positive effect on carcase parameters, but a negative effect on pH, meat tenderness and cooking loss, and the two genotypes exhibited different responses to the influence of nutrient density and age. 5. Genotype and age had the largest effect on carcase performance and meat quality. LND benefited meat quality and WRRC had larger responses in meat yield and shear force when fed on HND.

Promoter methylation negatively correlated with mRNA expression but not tissue differential expression after heat stress

DNA methylation plays a central role in gene expression. In this study, we detected the promoter methylation pattern of the chicken heat shock protein 70 (HSP70) gene and its association with messenger RNA (mRNA) expression before and after heat shock. The results showed that mRNA expression increased in response to heat stress and peaked at 3 h before dropping. Hypomethylation of the HSP70 promoter occurred in all of the groups studied, but the difference between groups within tissue type was not significant. The DNA methylation level of the control and the 6-h treatment groups was slightly higher than that of the 3-h treatment group in brain tissue and leg muscle. Correlation analysis between mRNA expression and DNA methylation of HSP70 showed that DNA methylation was negatively associated with mRNA expression in leg muscle (P = 0.0124), indicating that DNA methylation may be negatively associated with the expression of HSP70, although the difference was not significant. We concluded that the expression of HSP70 is heat inducible and tissue dependent and that heat induction may correlate with DNA methylation pattern in the HSP70 promoter, whereas tissue dependence is unrelated to DNA methylation pattern.

Polymorphisms associated with egg number at 300 days of age in chickens

We looked for variations that could be associated with chicken egg number at 300 days of age (EN300) in seven genes of the hypothalamic-pituitary-gonadal axis, including gonadotrophin-releasing hormone-I (GnRH-I), GnRH receptor (GnRHR), neuropeptide Y (NPY), dopamine D2 receptor (DRD2), vasoactive intestinal polypeptide (VIP), VIP receptor-1 (VIPR-1), prolactin (PRL), and the QTL region between 87 and 105 cM of the Z chromosome. Ten mutations in the seven genes were chosen to do marker-trait association analyses in a population comprising 1310 chickens, which were obtained from a company located in Guangdong Province of China. The C1704887T of VIPR-1 was found to have a highly significant association with EN300. The T5841629C of DRD2 and the C1715301T of VIPR-1 were significantly associated with EN300. A highly significant association was also found between the C1704887T-C1715301T haplotypes of VIPR-1 and EN300. H1H3 had the highest EN300. Four PCR-RFLP variations in the candidate QTL region were selected to investigate their genetic effects on EN300. The haplotypes of T32742468C-G32742603A in this region showed a highly significant association with EN300. Bioinformatics analyses showed that both T32742468C and G32742603A were located in intron 1 of the SH3-domain GRB2-like 2 (SH3GL2) gene. We conclude that five SNPs, including C1704887T and C1715301T of VIPR-1, T5841629C of DRD2, and T32742468C and G32742603A of SH3GL2, would be useful as markers for breeding to increase chicken EN300.

Association of Single Nucleotide Polymorphisms of the Insulin Gene with Chicken Early Growth and Fat Deposition

Growth rate, body composition, and fat deposition are important traits in chickens. Insulin plays important roles in hepatic cells, muscle cells, and adipose tissue cells. The purpose of the present study was to analyze association of the insulin (INS) gene with chicken growth and body composition traits. Using a F2 design resource population constructed with the crossing of Chinese native Xinghua chickens and White Recessive Rock chickens, the association of 4 single nucleotide polymorphisms (SNP; A+428G, C+1549T, T+3737C, and A+3971G) of INS gene with 13 growth and body composition traits was studied. The T+3737C genotypes were significantly associated with small intestine length (P = 0.0002), and the A+3971G genotypes were significantly associated with early growth (hatch weight and BW at 28 d of age) (P < 0.0001), breast angle (P = 0.0002), and small intestine length (P < 0.0001). None of the 4 SNP was significantly associated with abdominal fat pad weight (P > 0.05). The haplotypes based on the 4 SNP were also significantly associated with early growth (hatch weight and BW at 28 d of age; P < 0.0001) and breast angle (P < 0.0001) but not with small intestine length (P = 0.0505). These results suggested that variation of the insulin gene was significantly associated with chicken early growth but not with fat deposition. In addition, the data from the present study supported the inference that both the one-SNP-at-a-time and the haplotype-based approaches have their own advantages and disadvantages when association analysis of one SNP and haplotypes with chicken complex traits was conducted.

Single nucleotide polymorphisms of the chicken insulin-like factor binding protein 2 gene associated with chicken growth and carcass traits

Five single nucleotide polymorphisms (SNP) of the chicken insulin-like factor binding protein 2 (IGFBP2) gene were selected to genotype a F2 designed population with restriction fragment length polymorphisms and single stranded-conformation polymorphisms. The associations of the SNP and their haplotypes with chicken growth and carcass traits were analyzed. Results showed that the difference induced by the haplotypes derived from the 5 SNP was more significant than that by the single SNP in the genotype-phenotype association analysis. The haplotypes were associated with BW at hatch and at 21, 28, 42, 49, 56, and 90 d of age, as well as eviscerated weight with giblets (EWG), eviscerated weight (EW), and weights of heart, liver, and gizzard (HLGW) (P < or = 0.01). The haplotypes were also related to BW at 7, 14, and 35 d of age, breast depth, carcass weight, and breast muscle weight (P < or = 0.05). Significant and suggestive dominant effects of H1H5 diplotype were detected for BW at 7, 14, 21, 28, and 90 d of age, as well as breast depth, carcass weight, eviscerated weight with giblets, eviscerated weight, breast muscle weight, leg muscle weight, and weights of heart, liver, and gizzard. It was concluded that H1H5 was the most advantageous diplotype, and H4H10 was the negative diplotype for growth and carcass traits.

Characteristics and superoxide-induced activation of reconstituted myocardial mitochondrial ATP-sensitive potassium channels

Mitochondrial ATP-sensitive potassium (mitoK(ATP)) channels have been suggested as triggers and end effectors in myocardial ischemic preconditioning. However, the intracellular mechanism regulating mitoK(ATP) channels remains unclear. In the present study, mitoK(ATP) channels from bovine ventricular myocardium were reconstituted using planar lipid bilayers, and the effect of superoxide (O(2-.)) on the activity of these reconstituted channels was examined. After incorporation, a potassium-selective current was recorded. The mean conductance of this current was 56 pS at 150 mmol/L KCl, which was substantially inhibited by 1 mmol/L MgATP. 5-Hydroxydecanoate (5-HD, 10 to 100 micromol/L), a selective mitoK(ATP) antagonist, reduced the open state probability (NPo) of these channels in a concentration-dependent manner, whereas diazoxide (10 micromol/L), a selective mitoK(ATP) agonist, significantly increased channel activity. HMR-1098 (100 micromol/L), a selective sarcolemmal K(ATP) antagonist, had no effect on the activity of reconstituted channels. Addition of xanthine/xanthine oxidase (100 micromol/L per 0.038 U/mL), an O(2-.)-generating system, resulted in a marked activation of mitoK(ATP) channels; the NPo of the channels was increased from 0.60+/-0.10 to 1.94+/-0.02. This O(2)(-.)-induced channel activation was completely abolished by pretreatment with 5-HD (100 micromol/L) or a sulfhydryl alkylating compound, N-ethylmaleimide (2 mmol/L). It is concluded that myocardial mitoK(ATP) channels can be reconstituted into lipid bilayers and that O(2-.) activates these channels. The effect of O(2-.) may be associated with its direct action on the sulfhydryl groups of the channel protein.

Production and metabolism of ceramide in normal and ischemic-reperfused myocardium of rats

Ceramide has been shown to be a key signaling molecule involved in the apoptotic effect of tumor necrosis factor alpha (TNF-alpha) and other cytokines. Given the importance of cytokines such as TNF-alpha in myocardial ischemia-reperfusion injury, we hypothesize that ceramide is increased during ischemia or reperfusion, and that the activity of enzymes responsible for its production or breakdown should be increased and/or decreased, respectively. Therefore, in the present study, we characterized the enzymatic activities responsible for ceramide production and metabolism in the myocardium of rats, and determined the contribution of these enzymes to altered ceramide levels during myocardial ischemia and reperfusion. The basal ceramide concentration in the myocardium of rats was 34.0 pmol/mg tissue. As determined by the conversion of 14C-sphingomyelin into ceramide and 14C-choline phosphate, both neutral (N-) and acidic (A-) SMase were detected in the myocardium, with a conversion rate of 0.09 +/- 0.008 and 0.32 +/- 0.05 nmol/min per mg protein, respectively. The activity of A-SMase (78 % of total cellular activity) was significantly higher in microsomes than in cytosol, while the activity of N-SMase was similar in both fractions. Ceramidase, a ceramide-metabolizing enzyme, was also detected in the myocardium of rats. It metabolized ceramide into sphingosine at a rate of 9.94 +/- 0.42 pmol/min per mg protein. In anesthetized rats, 30 min of ischemia had no apparent effect on ceramide concentrations in the myocardium, while 30 min of ischemia followed by 3 h of reperfusion resulted in a significant increase in ceramide by 48 %. The activities of both N- and A-SMase were reduced by 44 % and 32 %, respectively, in the myocardium subjected to ischemia followed by reperfusion, but unaltered in the ischemic myocardium. It was also found that myocardial ischemia followed by reperfusion produced a marked inhibition of ceramidase (by 29 %). These results demonstrate that the myocardium of rats expresses N- and A-SMase and ceramidase, which contribute to the production and metabolism of ceramide, respectively. Tissue ceramide concentrations increased in reperfused myocardium. These increases in ceramide were not associated with enhanced SMase activity, but rather with reduced ceramidase activity.

Ceramide reduces endothelium-dependent vasodilation by increasing superoxide production in small bovine coronary arteries

Ceramide serves as a second messenger in a variety of mammalian cells. Little is known regarding the role of ceramide in the regulation of vascular endothelial function. The present study was designed to determine whether ceramide affects endothelium-dependent vasodilation in coronary arteries and to explore the mechanism of action of ceramide. In isolated and pressurized small bovine coronary arteries, cell-permeable C(2)-ceramide (10(-)(5) mol/L) markedly attenuated vasodilator responses to bradykinin and A23187 (by 40% and 60%, respectively). In the presence of K(G)-nitro-L-arginine methyl ester, ceramide produced no further inhibition on the vasodilation induced by these vasodilators. Ceramide had no effect on DETA NONOate-induced vasodilation. By use of a fluorescence NO indicator (4,5-diaminofluorescein diacetate), intracellular NO was measured in the endothelium of freshly isolated small coronary arteries. It was found that ceramide significantly inhibited bradykinin-induced NO increase within endothelial cells. However, it had no effect on the activity of arterial or endothelial NO synthase. Pretreatment of the arteries with sodium dihydroxybenzene disulfonate (Tiron, 10(-)(3) mol/L), a cell-permeable superoxide scavenger, or polyethylene glycol superoxide dismutase (100 U/mL) largely restored the inhibitory effects of ceramide on the vasodilation and NO increase induced by bradykinin or A23187. Moreover, ceramide time-dependently increased intracellular superoxide (O(2)(-. )) in the endothelium, as measured by a fluorescent O(2)(-. )indicator, dihydroethidium. These results demonstrate that ceramide inhibits endothelium-dependent vasodilation in small coronary arteries by decreasing NO in vascular endothelial cells and that this decrease in NO is associated with increased O(2)(-. ) but not with the inhibition of NO synthase activity within these cells.

Genomic gigantism: DNA loss is slow in mountain grasshoppers

Several studies have shown DNA loss to be inversely correlated with genome size in animals. These studies include a comparison between Drosophila and the cricket, Laupala, but there has been no assessment of DNA loss in insects with very large genomes. Podisma pedestris, the brown mountain grasshopper, has a genome over 100 times as large as that of Drosophila and 10 times as large as that of Laupala. We used 58 paralogous nuclear pseudogenes of mitochondrial origin to study the characteristics of insertion, deletion, and point substitution in P. pedestris and Italopodisma. In animals, these pseudogenes are "dead on arrival"; they are abundant in many different eukaryotes, and their mitochondrial origin simplifies the identification of point substitutions accumulated in nuclear pseudogene lineages. There appears to be a mononucleotide repeat within the 643-bp pseudogene sequence studied that acts as a strong hot spot for insertions or deletions (indels). Because the data for other insect species did not contain such an unusual region, hot spots were excluded from species comparisons. The rate of DNA loss relative to point substitution appears to be considerably and significantly lower in the grasshoppers studied than in Drosophila or Laupala. This suggests that the inverse correlation between genome size and the rate of DNA loss can be extended to comparisons between insects with large or gigantic genomes (i.e., Laupala and Podisma). The low rate of DNA loss implies that in grasshoppers, the accumulation of point mutations is a more potent force for obscuring ancient pseudogenes than their loss through indel accumulation, whereas the reverse is true for Drosophila. The main factor contributing to the difference in the rates of DNA loss estimated for grasshoppers, crickets, and Drosophila appears to be deletion size. Large deletions are relatively rare in Podisma and Italopodisma.

Adenosine diphosphate ribose dilates bovine coronary small arteries through apyrase- and 5'-nucleotidase-mediated metabolism

Cyclic adenosine diphosphate ribose and adenosine diphosphate ribose (ADPR) play an important role in the regulation of intracellular Ca(2+) release and K(+) channel activity in the coronary arterial smooth muscle. The role of these signaling nucleotides in the control of vascular tone has yet to be determined. The present study was designed to determine whether ADPR produces vasodilation in coronary arteries and to explore the mechanism of action of ADPR. ADPR (10-60 micromol/l) was found to produce endothelium-independent relaxation in a concentration-dependent manner in isolated and pressurized small bovine coronary arteries. The ADPR-induced vasodilation was substantially attenuated by adenosine deaminase (0.2 U/ml), and the P(1) purinoceptor antagonist 8-(p-sulfophenyl)theophylline (50 micromol/l), with maximal inhibitions of 60 and 80%, respectively. When the coronary arterial homogenates were incubated with ADPR, the production of adenosine and 5'-AMP was detected. The adenosine production was blocked by the 5'-nucleotidase inhibitor, alpha,beta-methylene adenosine 5'-diphosphate (MADP, 1 mmol/l), which was accompanied by a corresponding accumulation of 5'-AMP. This 5'-AMP accumulation was substantially inhibited by the apyrase inhibitor sodium azide (10 mmol/l). Moreover, ADPR was hydrolyzed into 5'-AMP by purified apyrase. In agreement with their inhibitory effect on the adenosine production, MADP and sodium azide significantly attenuated the vasodilator response to ADPR. The metabolism of ADPR to adenosine was only detected in cultured coronary arterial smooth muscle cells but not in endothelial cells. We concluded that ADPR produces vasodilation in small coronary arteries and that the action of ADPR is associated with the adenosine production via an apyrase- and 5'-nucleotidase-mediated metabolism.

Nitric oxide inhibits Ca(2+) mobilization through cADP-ribose signaling in coronary arterial smooth muscle cells

The present study was designed to determine whether the cADP-ribose-mediated Ca(2+) signaling is involved in the inhibitory effect of nitric oxide (NO) on intracellular Ca(2+) mobilization. With the use of fluorescent microscopic spectrometry, cADP-ribose-induced Ca(2+) release from sarcoplasmic reticulum (SR) of bovine coronary arterial smooth muscle cells (CASMCs) was determined. In the alpha-toxin-permeabilized primary cultures of CASMCs, cADP-ribose (5 microM) produced a rapid Ca(2+) release, which was completely blocked by pretreatment of cells with the cADP-ribose antagonist 8-bromo-cADP-ribose (8-Br-cADPR). In intact fura 2-loaded CASMCs, 80 mM KCl was added to depolarize the cells and increase intracellular Ca(2+) concentration ([Ca(2+)](i)). Sodium nitroprusside (SNP), an NO donor, produced a concentration-dependent inhibition of the KCl-induced increase in [Ca(2+)](i), but it had no effect on the U-46619-induced increase in [Ca(2+)](i). In the presence of 8-Br-cADPR (100 microM) and ryanodine (10 microM), the inhibitory effect of SNP was markedly attenuated. HPLC analyses showed that CASMCs expressed the ADP-ribosyl cyclase activity, and SNP (1-100 microM) significantly reduced the ADP-ribosyl cyclase activity in a concentration-dependent manner. The effect of SNP was completely blocked by addition of 10 microM oxygenated hemoglobin. We conclude that ADP-ribosyl cyclase is present in CASMCs, and NO may decrease [Ca(2+)](i) by inhibition of cADP-ribose-induced Ca(2+) mobilization.

[The location of inserting the electrode into the cochlear]

OBJECTIVE

To determine the position of implanting electrode into the scala tympani.

METHOD

The analogous operation of cochlear implantation were made in 50 temporal bones and the anatomic data were measured after the operation.

RESULT

The position of implanting electrode is 2.77 mm below the vestibular window and 0.85 mm anterior to the round window.

CONCLUSION

It suggests that this anatomic parameter provide a reference value to determine the position of cochlear implant electrode into the scala tympani.

[The discrimination rate in the consonant by cochlear implanted]

OBJECTIVE

To evaluate the effect of the discrimination rate in the consonant by cochlear implanted.

METHOD

The four cases by cochlear implanted have rehabilitated with hearing speech for 1.0-1.5 years.

RESULT

The discrimination rate in the four cases by cochlear implanted was 76.0% in the consonant, 94.1% in the vowel.

CONCLUSION

The discrimination rate in common language of Chinese was lower than that of vowel. When the patients discriminated the consonants with the same formants feature, the chance of the auditory is relatively high.

Estradiol enhances the induction of homosynaptic long-term depression in the CA1 region of the adult, ovariectomized rat

An ovarian steroid-dependent cycle of synaptogenesis and synapse shedding occurs naturally in the hippocampus of the adult female rat. The newly formed axospinous synapses in CA1 may differ functionally from extant axospinous synapses, e.g., in terms of their modifiability. Here we assess whether estradiol alters the induction of homosynaptic long-term depression of the Schaffer collateral-CA1 synapses in vitro. Sprague-Dawley rats were bilaterally ovariectomized and, beginning 6-8 days later, received a series of injections of either 17beta-estradiol or sesame oil sc. Field potentials were recorded in hippocampal slices. In estradiol-treated animals, asynchronous, low-frequency stimulation led to significant long-term depression of the activated synapses in CA1 s. radiatum and no change of the inactive synapses in s. oriens. In contrast, this conditioning stimulation did not significantly alter any CA1 responses in oil-treated control animals. Subsequent high-frequency conditioning stimulation significantly potentiated the activated s. radiatum synapses in both estradiol- and oil-treated animals. Thus, given the stimulation conditions used here, estradiol enables the induction of homosynaptic long-term depression at the CA3-CA1 synapses in adult females.

Frequent assimilation of mitochondrial DNA by grasshopper nuclear genomes

Multiple copies of mitochondrial-like DNA were found in the brown mountain grasshopper, Podisma pedestris (Orthoptera: Acrididae), paralogous to COI and ND5 regions. The same was discovered using the ND5 regions of nine other grasshopper species from four separate subfamilies (Podisminae, Calliptaminae, Cyrtacanthacridinae, and Gomphocerinae). The extra ND5-like sequences were shown to be nuclear in the desert locust, Schistocerca gregaria (Cyrtacanthacridinae), and probably so in P. pedestris and an Italopodisma sp. (Podisminae). Eighty-seven different ND5-like nuclear mitochondrial pseudogenes (Numts) were sequenced from 12 grasshopper individuals. Different nuclear mitochondrial pseudogenes, if descended from the same mitochondrial immigrant, will have diverged from each other under no selective constraints because of their loss of functionality. Evidence of selective constraints in the differences between any two Numt sequences (e.g., if most differences are at third positions of codons) implies that they have separate mitochondrial origins. Through pairwise comparisons of pseudogene sequences, it was established that there have been at least 12 separate mtDNA integrations into P. pedestris nuclear genomes. This is the highest reported rate of horizontal transfer between organellar and nuclear genomes within a single animal species. The occurrence of numerous mitochondrial pseudogenes in nuclear genomes derived from separate integration events appears to be a common phenomenon among grasshoppers. More than one type of mechanism appears to have been involved in generating the observed grasshopper Numts.

Thalamic excitation of hippocampal CA1 neurons: a comparison with the effects of CA3 stimulation

CA1 is the major output area for the hippocampus, and current evidence shows that it is excited primarily from ipsilateral and contralateral CA3 pyramidal cells in the rat. Direct connections from the midline thalamic nuclei to the hippocampus have been described anatomically, but the physiological role of these connections has not been reported until the recent observation that these inputs may have a mild excitatory effect (subthreshold for population spikes). In this study, we report a more powerful excitatory effect of thalamic stimulation on the response of the CA1 neurons in the urethane-anesthetized rat. Electrical stimulation to the midline thalamus induced responses similar to responses from stimulation of the contralateral hippocampus (CA3), with well-developed field excitatory postsynaptic potentials and large population spikes. The latency of the CA1 response suggested that the thalamic connection was monosynaptic, and there was a laminar CA1 response profile that depended on the site of stimulation (contralateral CA3 or thalamus). In an initial examination of possible differences in the physiological effects of these two pathways on the CA1 region, we tested both sites for long-term potentiation of CA1, for the effects of repetitive stimulation on CA1 responses (e.g., possible augmenting responses) and for the effect of paired-pulse stimulation. In these three measures, there were clear and statistically significant differences between the effects of CA3 and thalamic stimulation on CA1 responses. This study demonstrates that the well-described thalamic connection to the hippocampus allows for the direct and powerful excitation of the CA1 region. This thalamohippocampal connection bypasses the trisynaptic/commissural pathway that has been thought to be the exclusive excitatory drive to CA1. In addition, preliminary data indicate that the thalamus and CA3 inputs have different physiological effects on CA1 pyramidal cells.

Effect of ceramide on KCa channel activity and vascular tone in coronary arteries

A sphingomyelin metabolite, ceramide, serves as a second messenger in a variety of mammalian cells. Little is known regarding the production and actions of this novel intracellular signaling lipid molecule in the vasculature. The present study was designed to test the hypothesis that a ceramide-mediated signaling pathway is present in coronary arterial smooth muscle and that ceramide serves as an inhibitor of the large-conductance Ca2+-activated potassium (KCa) channels and mediates vasoconstriction in coronary circulation. We found that C2-ceramide produced a concentration-dependent decrease in KCa channel activity in vascular smooth muscle cells from small bovine coronary arteries. The average channel activity of the KCa channels in cell-attached patches decreased from 0.046+/-0.01 to 0. 008+/-0.001 at a C2-ceramide concentration of 10 micromol/L. In inside-out patches, C2-ceramide (1 micromol/L) reduced the average channel activity of the KCa channels from 0.06+/-0.007 to 0.016+/-0. 004. Dithiothreitol, an inhibitor of acidic sphingomyelinase (1 mmol/L), increased the average channel activity of the KCa channels in cell-attached patches from 0.05+/-0.02 of control to 0.26+/-0.04, a 5-fold increase that was reversed by addition of 1 micromol/L ceramide. Glutathione, an inhibitor of neutral sphingomyelinase, was without effect. C2-ceramide significantly reduced the diameter of isolated perfused small coronary arteries in a concentration-dependent manner. Addition of 1 micromol/L C2-ceramide decreased average arterial diameter by 28%. When 14C-sphingomyelin was incubated with coronary arterial homogenates at pH 7.4 and pH 5. 0, 14C-choline phosphate and ceramide were produced. The conversion rates of 14C-sphingomyelin into 14C-choline phosphate and ceramide were 65.1+/-1.0 fmol/min per milligram protein at pH 7.4 and 114. 6+/-8.3 fmol/min per milligram protein at pH 5.0. We conclude that both acidic and neutral sphingomyelinases are present in the bovine coronary arteries and that ceramide inactivates the KCa channel in arterial smooth muscle cells and hence exerts a tonic vasoconstrictor action in coronary microcirculation.