Visible-light-driven, water-surface-floating antimicrobials developed from graphitic carbon nitride and expanded perlite for water disinfection

Waterborne pathogens, especially bacteria and viruses, pose significant health risks to the public, calling for the development of a sustainable, efficient, and robust disinfection strategy with reduced energy footprint and minimized byproduct formation. Here, we developed a sustainable photocatalytic composite for antimicrobial applications by integrating visible-light-responsive graphitic carbon nitride (g-C₃N₄) with low-density porous expanded perlite (EP) mineral, and g-C₃N₄/EP-520 showed a high specific surface area of 45.3 m²/g and optimum performance for disinfection. g-C₃N₄/EP-520 achieved 8-log inactivation of E. coli and MS2 under 180 and 240 min visible-light irradiation without stirring, respectively. Water quality parameters were found to influence the disinfection performance of g-C₃N₄/EP-520: MS2 inactivation was promoted with the increase of dissolved oxygen (DO), proton concentration, salinity (NaCl), and hardness (Ca²⁺). Importantly, g-C₃N₄/EP-520 could fully inactivate MS2 in a real source water sample with prolonged light irradiation, and negligible activity loss was observed in recycle use, demonstrating its viability and robustness for waterborne pathogen removal. Antimicrobial mechanisms of g-C₃N₄/EP-520 were systemically evaluated by radical scavenger addition, and revealed that the inactivation behavior was dependent on the type of microorganisms. Microscopic analyses confirmed that the destruction of bacterial cells and viral particles, leading to the inactivation of microorganisms.

Effects of chronic dexamethasone exposure on bile acid metabolism and cecal epithelia function in goats

Bile acids (BAs) are synthesized in the liver via the oxidation of cholesterol and further metabolized by microbiota in the gut, where they simultaneously impact gut function. In the present study, 10 goats were randomly divided into 2 groups; 1 group was injected with dexamethasone (Dex; 0.2 mg/kg), and the other group was injected with saline as the control (Con) for 21 d. Expression levels of key genes and proteins in the liver and gut mucosa were analyzed and compared to investigate the impact of chronic stress on BA metabolism and related functions in ruminants. The results revealed that Dex decreased plasma total BAs (TBAs) concentration (P < 0.05) but increased TBA concentration in the cecal digesta (P < 0.05). Total cholesterol in the liver decreased moderately in response to Dex. The protein expression of cytochrome P450 family 7 subfamily A member 1 and cytochrome P450 family 27 subfamily A member 1, 2 enzymes that control BA synthesis in the liver, remained unchanged by Dex administration (P > 0.05). The expression of several genes in the cecal mucosa encoding epithelial tight junction proteins, including occludin (P < 0.05), tight junction protein 1 (P < 0.01), and claudin 1 (P < 0.05), increased significantly in response to Dex, and expression of defensin beta 1, which can strengthen the innate immune system, was also upregulated (P < 0.05). In addition, BAs increased the expression of the Solute Carrier family 9 member A 2 (P < 0.01) that encodes a sodium hydrogen exchanger. These results suggest that the Dex-induced disruption of BA homeostasis might be mediated through a liver-independent pathway in goats, and the Dex-induced accumulation of TBAs in the cecal digesta may improve volatile fatty acid transportation and mucosal defense.

Analysis of the correlation between the neutrophil-lymphocyte ratio in peripheral blood and perioperative myocardial damage in pediatric patients with frequent ventricular premature beat

OBJECTIVE

The objective of the present study was to investigate the relationship between the neutrophil-lymphocyte ratio (NLR) in peripheral blood and myocardial damage in pediatric patients with frequent ventricular premature beat (FVPB), and provide a reference for myocardial preservation in these patients.

PATIENTS AND METHODS

A total of 212 pediatric patients who were treated in the Department of Cardiology, Xuzhou Children's Hospital between December 2014 and March 2016 for FVPB, were selected. The results of routine blood exam, and levels of cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) in patients after the onset of FVPB were analyzed, and NLR was calculated. According to NLR levels, patients were divided into four groups using quartiles.

RESULTS

With increases of NLR, the proportion of patients with a history of hypertension and ejection fraction < 50% increased gradually, and white blood cells (WBCs), the peaks of CK-MB and cTnI, and serum creatinine levels were significantly increased (p<0.05, p<0.01). There were no significant differences (p>0.05) in age, sex, body mass index, serum creatinine before treatment, fasting blood glucose, TG, TC, LDL-C, and HDL-C among the four groups. Multiple stepwise regression analysis showed that for patients with FVPB, NLR in peripheral blood was positively correlated with the peak of cTnI (r=0.538, p<0.05). NLR was positively correlated with levels of WBCs (r=0.661, p<0.05) and there was no correlation between NLR and history of hypertension, ejection fraction, and the laboratory results of creatinine peak and CK-MB. The differences were not statistically significant (p>0.05). However, the peak of cTnI was positively correlated with the levels of WBCs (r=0.189, p=0.003).

CONCLUSIONS

NLR and WBCs in patients with FVPB are positively related to the peak of cTnI. NLR may serve as an excellent marker that reflects myocardial damage in pediatric patients with FVPB.

Effect of Surgical Adhesive on the Uterus of Rabbits Following Occlusion

Purpose/Aim of the Study: The present study investigated the effect of surgical adhesives on the uterus of rabbits and the histomorphology alterations following occlusion, to improve the clinical treatment of abnormal fallopian tube with surgical adhesives for in vitro fertilization and embryo transfer (IVF-ET). Materials and Methods: The experimental rabbits received laparotomy and occlusion of the uterus by surgical adhesive adjacent to the two fallopian tubes, while the control rabbits only received laparotomy. The body weight, hysterosalpingography, and histomorphology were measured to evaluate the uterine occlusion at 1 and 6 months after surgery. Results: There was no significant difference in the mortality rate or body weight between the experimental and control groups. In the experimental group, 38 uterine cavities were identified in 19 rabbits, of which 97.37% were occluded, with expanded uterine cavity and tissue oppression at 1 month after surgery. In total, 33 uterine cavities out of the 36 in the control group were occluded, with proliferation of new stratified epithelial cells observed at 6 months after surgery. In the control group, 20 uterine cavities of 10 rabbits were observed to be absent of occlusion at 1 month after surgery, while 18 uterine cavities in the remaining 9 rabbits were also absent of occlusion at 6 months after the surgery. Conclusion: Surgical adhesives are effective in occluding the uterus of rabbits without adverse effects, supporting their potential clinical use to treat the occlusion in abnormal fallopian tubes prior to IVF-ET.

Response of ammonia oxidizing archaea and bacteria to decabromodiphenyl ether and copper contamination in river sediments

Ammonia oxidation plays a fundamental role in river nitrogen cycling ecosystems, which is normally governed by both ammonia oxidizing archaea (AOA) and ammonia oxidizing bacteria (AOB). Co-contamination of typical emerging pollutant Polybrominated diphenyl ethers (PBDEs) and heavy metal on AOA and AOB communities in river sediments remains unknown. In this study, multiple analytical tools, including high-throughput pyrosequencing and real-time quantitative PCR (qPCR), were used to reveal the ammonia monooxygenase (AMO) activity, subunit alpha (amoA) gene abundance, and community structures of AOA and AOB in river sediments. It was found that the inhibition of AMO activities was increased with the increase of decabromodiphenyl ether (BDE 209, 1-100 mg kg^-1) and copper (Cu, 50-500 mg kg^-1) concentrations. Moreover, the synergic effects of BDE 209 and Cu resulted in a higher AMO activity reduction than the individual pollutant BDE 209. The AOA amoA copy number declined by 75.9% and 83.2% and AOB amoA gene abundance declined 82.8% and 90.0% at 20 and 100 mg kg^-1 BDE 209 with a 100 mg kg^-1 Cu co-contamination, respectively. The pyrosequencing results showed that both AOB and AOA community structures were altered, with a higher change of AOB than that of AOA. The results demonstrated that the AOB microbial community may be better adapted to BDE 209 and Cu pollution, while AOA might possess a greater capacity for stress resistance. Our study provides a better understanding of the ecotoxicological effects of heavy metal and micropollutant combined exposure on AOA and AOB in river sediments.

New insights into the spatial variability of biofilm communities and potentially negative bacterial groups in hydraulic concrete structures

The composition and distribution characteristics of bacterial communities in biofilms attached to hydraulic concrete structure (HCS) surfaces were investigated for the first time in four reservoirs in the middle and lower reaches of the Yangtze River Basin using 16S rRNA Miseq sequencing. High microbial diversity was found in HCS biofilms, and notable differences were observed in different types of HCS. Proteobacteria, Cyanobacteria and Chloroflexi were the predominant phyla, with respective relative abundances of 35.3%, 25.4% and 13.0%. The three most abundant genera were Leptolyngbya, Anaerolineaceae and Polynucleobacter. The phyla Beta-proteobacteria and Firmicutes and genus Lyngbya were predominant in CGP, whereas the phyla Cyanobacteria and Chloroflexi and genera Leptolyngbya, Anaerolinea and Polynucleobacter survived better in land walls and bank slopes. Dissolved oxygen, ammonia nitrogen and temperature were characterized as the main factors driving the bacterial community composition. The most abundant groups of metabolic functions were also identified as ammonia oxidizers, sulphate reducers, and dehalogenators. Additionally, functional groups related to biocorrosion were found to account for the largest proportion (14.0% of total sequences) in gate piers, followed by those in land walls (11.5%) and bank slopes (10.2%). Concrete gate piers were at the greatest risk of biocorrosion with the most abundant negative bacterial groups, especially for sulphate reducers. Thus, it should be paid high attention to the biocorrosion prevention of concrete gate piers. Overall, this study contributed to the optimization of microbial control and the improvement of the safety management for water conservation structures.

Sediment bacterial communities in a eutrophic lake influenced by multiple inflow-rivers

Sediment bacterial communities are sensitive to environmental fluctuations, particularly external input sources. Studying the relationships between bacterial community distribution and the estuarine environment is critical for understanding the river-lake confluence ecosystem and the effect of inflow-rivers on lakes. In the present study, bacterial communities from the sediments of 14 estuaries and four pelagic sites of the Taihu Lake were investigated via high-throughput sequencing. The results demonstrated that Delta-, Beta-, and Gamma-proteobacteria, Acidobacteria, Nitrospira, Bacilli, Anaerolineae, and Actinobacteria were the major classes in sediment bacterial communities of the Taihu Lake. In general, the inflow-rivers of different pollution types have distinctly different influences on sediment bacterial communities of the lake. The bacterial community composition and physicochemical properties of pelagic sites were closer to those of the estuaries of western region which was polluted by serious industrial and agricultural pollution. The bacterial community diversity of estuaries was lower than those of pelagic sites. Spearman correlation analysis indicated that α-diversity of the bacterial community was significantly correlated with C/N, total nitrogen, and total carbon in estuarine sediments. Redundancy analysis revealed that the variance in bacterial community composition was also significantly associated with C/N (24.9%) followed by total phosphorus (15.8%), nitrite (7.2%), and nitrate (7.7%) among different estuaries. This study provides a reference to understand the influence of inflow-rivers on the lake ecosystem, which offered a basic guidance for maintaining the ecological system and protecting the water environment of lacustrine basin.

Correlation between NFATC1 gene polymorphisms and congenital heart disease in children

OBJECTIVE

To analyze the links between NFATC1 gene polymorphism and congenital heart disease in children.

PATIENTS AND METHODS

In the present study, we selected 85 children patients with congenital heart disease who were hospitalized from February 2013 to February 2015 as research subjects (observation group), and 92 healthy subjects as control group. Restriction fragment length polymorphism (RFLP) was used for analysis of NFATC1 gene in samples from each group.

RESULTS

The distribution of NFATC1 genotype and allele between the observation group (children with congenital heart disease) and the control group showed no significant difference (p >0.05), but AA, GG genotypes, and allele frequency between pathological samples of children with congenital heart disease and the control group displayed significant difference (p <0.05) (X2 = 16.04, p <0.05; X2 = 16.29, p <0.05). Further analyses showed that AA, GG, AG genotype and allele frequency among children with congenital heart disease in observation group also showed a difference, i.e., homozygote (AA, GG) ratio in children with severe congenital heart disease is relatively high.

CONCLUSIONS

There is a correlation between NFATC1 genes and the incidence of congenital heart disease in children, and a correlation between different genotypes and allele frequency and the incidence of the disease.

Elevational characteristics of the archaeal community in full-scale activated sludge wastewater treatment plants at a 3,660-meter elevational scale

Due to the important roles of archaea in wastewater treatment processes, archaeal communities have been studied extensively in various anaerobic reactors, but the knowledge of archaeal communities in full-scale activated sludge wastewater treatment plants (WWTPs) remains quite poor. In this study, 454-pyrosequencing was for the first time employed to investigate archaeal communities from 20 full-scale activated sludge WWTPs distributed at a 3,660-meter elevational scale in China. Results showed that archaeal communities from WWTPs were dominated by Methanosarcinales (84.6%). A core archaeal population (94.5%) composed of Methanosaeta, Methanosarcina, Methanogenium and Methanobrevibacter was shared among WWTPs. The elevational pattern of archaeal communities was observed in WWTPs, with an elevational threshold associated with archaeal community richness and structures at approximately 1,500 meters above sea level (masl). A declining trend in community richness with increasing elevation was observed at higher elevations, whereas no trend was presented at lower elevations. Spearman correlation analysis indicated that the archaeal community richness at higher elevations was associated with more environmental variables than that at lower elevations. Redundancy analysis indicated that wastewater variables were the dominant contributors to the variation of community structures at higher elevations, followed by operational variables and elevation.

Development and validation of a bacteria-based index of biotic integrity for assessing the ecological status of urban rivers: A case study of Qinhuai River basin in Nanjing, China

With the increasing human disturbance to urban rivers, the extinction and biodiversity losses of some macroorganism species decreased the accuracy of bioassessment. In this study, a novel index of biotic integrity based on bacteria (Ba-IBI) was first developed for Qinhuai River in Nanjing city, China. Thirty-two biofilm samples were collected along the river bank and the bacterial communities were identified by high-throughput sequencing. By the range, responsive, and redundancy tests, four core metrics were selected from the dataset of 78 candidate metrics, including Pielou's evenness index, proportion of Paenibacillus, proportion of OTUs tolerant to organic pollution and proportion of Nitrosomonas. The results showed that the Ba-IBI was able to effectively discriminate different impaired site groups, and had a good correlation with the index of water quality (r = 0.79, p < 0.01) and the qualitative habitat evaluation index (r = 0.51, p < 0.01). Moreover, the Ba-IBI was negatively correlated with the number of population within a 1 km buffer (r = -0.71, p < 0.01). Application of the index showed that most of the sites were in the poor or bad class in the river. Our study revealed that the Ba-IBI is an effective and reliable approach for assessing the ecological status of Qinhuai River basin, which can complement the existing ecological assessment approaches for urban rivers. Meanwhile, repeted surveys and field validations are still needed to further improve the applicability of the index in future studies.

Evolving safety practices in the setting of modern complex operating room: role of nurses

Operating room (OR) nursing previously referred to patient care provided during the intra-operative phase and the service provided within the OR itself. With the expansion of responsibilities of nurses, OR nursing now includes pre-operative and post-operative periods, therefore peri-operative nursing is accepted as a nursing process in OR in the contemporary medical literature. Peri-operative nurses provide care to the surgical patients during the entire process of surgery. They have several roles including those of manager or a director, clinical practitioner (scrub nurse, circulating nurse and nurse anesthetist), educator as well as researcher. Although, utmost priority is placed on insuring patient safety and well-being, they are also expected to participate in professional organization, continuing medical education programs and participating in research activities. A Surgical Patient Safety Checklist formulated by the World Health Organization serves as a major guideline to all activities in OR, and peri-operative nurses are key personnel in its implementation. Communication among the various players of a procedure in OR is key to successful patient outcome, and peri-operative nurses have a central role in making it happen. Setting up of OR in military conflict zones or places that suffering a widespread natural disaster poses a unique challenge to nursing. This review discusses all aspects of peri-operative nursing and suggests points of improvement in patient care.

Ignored fungal community in activated sludge wastewater treatment plants: diversity and altitudinal characteristics

Fungi are important contributors to the various functions of activated sludge wastewater treatment plants (WWTPs); however, the diversity and geographic characteristics of fungal populations have remained vastly unexplored. Here, quantitative polymerase chain reaction and 454 pyrosequencing were combined to investigate the abundance and diversity of the activated sludge fungal communities from 18 full-scale municipal WWTPs in China. Phylogenetic taxonomy revealed that the members of the fungal communities were assigned to 7 phyla and 195 genera. Ascomycota and Basidiomycota were the most abundant phyla, dominated by Pluteus, Wickerhamiella, and Penicillium. Twenty-three fungal genera, accounting for 50.1 % of the total reads, were shared by 18 WWTPs and constituted a core fungal community. The fungal communities presented similar community diversity but different community structures across the WWTPs. Significant distance decay relationships were observed for the dissimilarity in fungal community structure and altitudinal distance between WWTPs. Additionally, the community evenness increased from 0.25 to 0.7 as the altitude increased. Dissolved oxygen and the C/N ratio were determined to be the most dominant contributors to the variation in fungal community structure via redundancy analysis. The observed data demonstrated the diverse occurrence of fungal species and gave a marked view of fungal community characteristics based on the previously unexplored fungal communities in activated sludge WWTPs.

Correlation analysis between GNAS2 gene polymorphisms in children with arrhythmia

OBJECTIVE

The objective of the present study was to analyze the correlation between GNAS2 gene polymorphisms and children with arrhythmia.

PATIENTS AND METHODS

We followed 89 children with arrhythmia treated in our hospital from April 2013 to April 2015, comprising the observation group, while 92 healthy subjects were taken as the control group. We analyzed polymorphisms of the GNAS2 gene from both groups by restriction fragment length polymorphism (RFLP).

RESULTS

There were no significant differences (p>0.05) in GNAS2 genotype or allelic distribution between the observation group and control group. However, there were significant differences in the gene frequency of homozygotes (TT and GG) and alleles between the control group and samples from children with arrhythmia (p<0.05) (X2=16.57, p<0.05; X2=17.48, p<0.05). Further study of samples from both groups indicate that gene frequency of homozygous (TT and GG) or heterozygous (TG) genes and alleles also had differences, indicating that homozygotes (TT and GG) are in relatively high proportion among patients with severe cases of arrhythmia.

CONCLUSIONS

Morbidity in patients with arrhythmia is related to GNAS2 gene polymorphisms. Differences in genotype and allele frequency are related to the severity of illness.

Experimental studies and kinetic modeling of the growth of phenol-degrading bacteria in turbulent fluids

Understanding the interaction between microorganisms and fluid dynamics is important for aquatic ecosystems, though only sporadic attention has been focused on this topic in the past. In this study, particular attention was paid to the phenol-degrading bacterial strains Microbacterium oxydans LY1 and Alcaligenes faecalis LY2 subjected to controlled fluid flow under laboratory conditions. These two strains were found to be able to degrade phenols over a concentration range from 50 to 500 mg/L under different turbulence conditions ranging from 0 to 250 rpm. The time it took to reach total phenol degradation decreased when the turbulence was increased in both strains, with increasing energy dissipation rates ranging from 0.110 to 6.241 W/kg, corresponding to changes in the bacterial diffusive sublayer thickness (δ) and enhanced oxygen uptake. Moreover, the maximum specific growth rates of the two strains also increased with the enhancement of turbulence. A model integrating growth inhibition and fluid motion was proposed based on the self-inhibition Haldane model by introducing a turbulence parameter, α. The resulting modified Haldane model was designed to include fluid motion as a variable in the quantification of the physiological responses of microorganisms. This modified Haldane model could be considered a useful laboratory reference when modeling procedures for water environment bioremediation. Graphical abstract Cell nutrition uptake cartoon schematic diagram for M. oxydans LY1 under different turbulent condition (50 and 200 rpm).

Modeling the Biodegradation of Bacterial Community Assembly Linked Antibiotics in River Sediment Using a Deterministic-Stochastic Combined Model

To understand the interaction between bacterial community assembly and the assembly linked antibiotics biodegradation, a unique model framework containing a Monod kinetic, a logistic kinetic, and a stochastic item was established to describe the biodegradation of bacterial community assembly linked sulfamethoxazole (SMX) in river sediment. According to the modeling results, both deterministic and stochastic processes driving bacterial population variations played important roles in controlling SMX biodegradation, and the relative importance depended on the in situ concentration of SMX. A threshold concentration of SMX, which was biodegraded in the experimental river sediment depending on different processes, was obtained (i.e., 20 μg/kg). The higher introduced concentration of SMX (>20 μg/kg) was found to promote the acclimation of antibiotic degradation bacteria in microbial community through niche differentiation, which resulted in the specific microbial metabolization of SMX. In contrast, the lower introduced concentration of SMX (<20 μg/kg) was not able to lead to a significant increase of deterministic processes and resulted in the biodegradation of SMX through co-metabolism by the coexisting microorganisms. The developed model can be considered a useful tool for improving the technologies of water environmental protection and remediation.

Effect of the pollution level on the functional bacterial groups aiming at degrading bisphenol A and nonylphenol in natural biofilms of an urban river

Bisphenol A (BPA) and 4-nonylphenol (NP) are ubiquitous pollutants with estrogenic activity in aquatic environment and have attracted global concern due to their disruption of endocrine systems. This study investigated the spatial distribution characteristics of the bacterial groups involved in the degradation of BPA and NP within biofilms in an urban river using terminal restriction fragment length polymorphism based on 16S rRNA gene sequences. The effects of the pollution level and water parameters on these groups were also assessed. Hierarchical cluster analysis grouped the sampling sites into three clusters reflecting their varying nutrient pollution levels of relatively slight pollution (SP), moderate pollution (MP), and high pollution (HP) based on water quality data and Environmental Quality Standard for Surface Water of China (GB3838-2002). The BPA and NP concentration in river water ranged from 0.8 to 77.5 and 10.2 to 162.9 ng L(-1), respectively. Comamonadaceae, Pseudomonadaceae, Alcaligenaceae, Bacillaceae, Sphingomonadacea, Burkholderiaceae, and Rhizobiaceae were the dominant bacterial taxa involved in BPA and NP degradation, comprising an average of 9.8, 8.1, 7.6, 6.7, 6.2, 4.1, and 2.8 % of total sequences, respectively. The total abundance of these groups showed a slight upward trend and subsequently rapidly decreased with increasing pollution levels. The average proportion of Comamonadaceae in MP river sections was almost 1.5-2 times than that in SP or HP one. The distribution of functional groups was found related to environmental variables, especially pH, conductivity, ammonium nitrogen (NH3-N), and BPA. The abundance of Comamonadaceae and Rhizobiaceae was both closely related to higher values of pH and conductivity as well as lower concentrations of NP and BPA. Alcaligenaceae and Pseudomonadaceae were associated with higher concentrations of TP and CODMn and inversely correlated with DO concentration. This study might provide effective data on bacterial group changes in polluted urban rivers.

Altitude-scale variation in nitrogen-removal bacterial communities from municipal wastewater treatment plants distributed along a 3600-m altitudinal gradient in China

Microbial ecological information on the nitrogen removal processes in wastewater treatment plants (WWTPs) has been of considerable importance as a means for diagnosing the poor performance of nitrogen removal. In this study, the altitude-scale variations in the quantitative relationships and community structures of betaproteobacteria ammonia-oxidizing bacteria (βAOB) and nitrite-reducing bacteria containing the copper-containing nitrite reductase gene (nirK-NRB) and the cytochrome cd1-containing nitrite reductase gene (nirS-NRB) were investigated in 18 municipal WWTPs distributed along a 3660-masl altitude gradient in China. An altitude threshold associated with the proportions of NRB to total bacteria, NRB to βAOB and nirK-NRB to nirS-NRB was detected at approximately 1500m above sea level (masl). Compared with the stable proportions below 1500masl, the proportions exhibited a pronounced decreasing trend with increased altitude above 1500masl. Spearman correlation analysis indicated that the trend was significantly driven by altitude as well as multiple wastewater and operational variables. The community structure dissimilarity of βAOB, nirK-NRB and nirS-NRB showed significant and positive correlations with altitudinal distance between WWTPs. Redundancy analyses indicated that the variation in community structures above 1500masl were predominantly associated with wastewater, followed by operation and altitude. In summary, although the variations of nitrogen-removal bacterial community in WWTPs were driven dominantly by wastewater and operational variables, altitude was also an important variable influencing the quantitative relationships and community structures of nitrogen-removal bacteria in WWTPs particularly above 1500masl.

Response of bacterial community compositions to different sources of pollutants in sediments of a tributary of Taihu Lake, China

Sediment bacterial communities are sensitive to water conditions in river ecosystems. The objective of this study was to compare the influences of different pollution sources, including urban areas, wastewater treatment plants (WWTPs), suburban areas, and agricultural areas, on sediment bacterial communities along a typical tributary of Taihu Lake, China. The dominant composition of the sediment bacterial community was determined using a combination of terminal restriction fragment length polymorphism (T-RFLP) and a 16S rRNA clone library. The results showed that the sediment bacterial communities were distinctly affected by the four pollution sources. Alphaproteobacteria, Betaproteobacteria, and Actinobacteria (>50 % in total) were the predominant bacterial taxa across the sediment samples. Apart from those, the sediment bacterial community composition (BCC) affected by WWTP effluent was subsequently dominated by Nitrospira (12.4 %) and Bacteroidetes (11.5 %), agriculture was dominated by Firmicutes (13.2 %) and Deltaproteobacteria (7.2 %), while urban and suburban were dominated by Bacteroidetes (7.6 and 7.9 %, respectively) and Deltaproteobacteria (7.9 and 7.6 %, respectively). Cluster analysis indicated that the BCC affected by WWTP effluent was distinct from the BCC in urban, suburban, and agricultural areas. In addition, the bacterial community richness and evenness affected by WWTP effluent were much less than those by the other pollution sources. Redundancy analysis (RDA) indicated that the variation in BCC across the sediment samples was significantly associated with ammonium (17 %), organic matter (12 %), and cadmium (3 %) (p < 0.01). Overall, the results indicated that the four different pollution sources (WWTP, urban, suburban, and agriculture) have dissimilar impacts on the sediment BCC in the tributary of Taihu Lake, while WWTPs exhibited the greatest potential to lead to biotic homogenization in river sediments.

Isolation and characterization of two novel psychrotrophic decabromodiphenyl ether-degrading bacteria from river sediments

Decabromodiphenyl ether (BDE-209) is a brominated flame retardant and a priority contaminant. Currently, little information is available about its significance in the environment, specifically about its susceptibility to aerobic biotransformation at low temperature. In this work, five phylogenetically diverse BDE-209-degrading bacterial strains were isolated from river sediments of northern China. These strains were distributed among four different genera-Acinetobacter, Pseudomonas, Bacillus and Staphylococcus. All five isolates were capable of growing on BDE-209, among which two isolates show better growth. By detailed morphological, physiological, and biochemical characteristics and 16S rDNA sequence analysis, the two strains were identified and named as Staphylococcus haemolyticus LY1 and Bacillus pumilus LY2. The two bacteria can grow in mineral salt medium containing BDE-209 substrate across the temperatures ranging from 2.5 to 35 °C, with an optimum temperature of 25 °C which could be considered as psychrotrophs accordingly. The degradation experiment showed that more than 70.6 and 85.5 % of 0.5 mg/L BDE-209 were degraded and the highest mineralization efficiencies of 29.8 and 39.2 % were achieved for 0.5 mg/L BDE-209 by S. haemolyticus LY1 and B. pumilus LY2, respectively. To the best of our knowledge, this is the first demonstration for the biodegradation of BDE-209 by two psychrotrophic bacteria isolated from environment.

[Phosphatase and tensin homolog deleted on chromosome ten/phosphatidyl Inositol 3-kinase/vascular endothelial growth factor signaling pathway changes in the rabbit Kawasaki disease model]

OBJECTIVE

To observe the changes of phosphatase and tensin homolog deleted on chromosome ten(PTEN)/ phosphatidyl Inositol 3-kinase(PI3K)/ vascular endothelial growth factor(VEGF)signaling pathway in a rabbit Kawasaki disease model.

METHODS

Model of Kawasaki disease was established in weanling Japanese big-eared rabbits with 10% bovine serum venous injection (2.5 ml/kg, 2 times, and 2 week's interval) through the ear. Twenty four rabbits were divided into 4 groups: control group (without injection of 10% bovine serum albumin, six rabbits); 1 day group (sacrificed a the second day after the establishment of Kawasaki disease models, six rabbits); 7 day group (sacrificed at the seventh day after establishment of Kawasaki disease model, six rabbits); 30 day group (sacrificed at the thirtieth day after establishment of Kawasaki disease model, six rabbits). Pathological analysis was performed on coronary artery tissue samples. The express of PTEN and PI3K were detected by immunohistochemistry. The levels of VEGF and CK were also examined with ELISA and white blood cells were counted.

RESULTS

(1) Coronary artery of model groups was thinner, distorted and had enlarged lumen. (2) PTEN expression in 1 d group, 7 d group and 30 d group were 58.5 ± 12.9, 73.2±9.9 and 109.6 ± 24.4, respectively, significantly higher than in the control group (25.5 ± 6.9, P<0.01 or 0.05). (3) The express of PI3K was significantly upregulated in 1 d group(57.2±11.1)and 7 d group(39.9±4.8) compared to control group(19.1±3.5, P<0.01 or 0.05). The expression level of PI3K in 30 d group was 18.8 ± 7.5, which was similar as control group (P>0.05) and significantly lower than 1 d and 7 d group (both P<0.05). (4) Similarly, the level of VEGF in 1 d group, 7 d group ((89.1 ± 15.5) ng/L, (76.9±9.9) ng/L) were significantly higher while it was significantly lower in 30 d group ((19.8 ± 4.4)ng/L) compared with the control group ((33.9 ± 6.7) ng/L, P<0.01 or 0.05). The level of VEGF in 7 d group was significantly lower than in 1 d group (P<0.05) and the level of VEGF was significantly lower in 30 d group than in 7 d group (P<0.01). (5)Creatine kinase levels were significantly higher in 30 d group than in control group (P<0.05) and there were no significantly different between control group, 1 d group and 7 d group(all P>0.05). (6)White blood cell count were significantly higher in 1 d group, 7 d group and 30 d group than in control group (all P<0.01).

CONCLUSION

The level of PTEN/PI3K/VEGF signaling pathway change after establishment of rabbit Kawasaki disease model and the signaling pathway might be involved in this model.

Isolation and growth kinetics of a novel phenol-degrading bacterium Microbacterium oxydans from the sediment of Taihu Lake (China)

Seven phylogenetically diverse phenol-degrading bacterial strains designated as P1 to P7 were isolated from the industry-effluent dump sites of an industrial area near Taihu Lake, China. Through the 16S rDNA sequence analysis, these strains were widely distributed among five different genera: Rhodococcus (P1), Pseudomonas (P2-P4), Acinetobacter (P5), Alcaligenes (P6), and Microbacterium (P7). All seven isolates were capable of growing with phenol as the sole carbon source. Strain P7 was found to be a novel phenol-degrading strain by detailed morphological, physiological and biochemical characteristic analysis as well as the 16S rDNA sequence analyses, and was named Microbacterium oxydans LY1 (M. oxydans LY1 in its short form). Degradation experiments of phenol at various initial concentrations (20-1,000 mg/L) revealed that phenol is an inhibitory substrate to M. oxydans LY1. In a batch culture experiment, more than 95% of the phenol (500 mg/L) was degraded by M. oxydans LY1 at 30°C, pH 7.0 and 120 rpm within 88 h. Phenol concentration higher than 200 mg/L was found to inhibit the bacterial growth. The growth kinetics correlated well with the Haldane model with μmax (maximum specific cell growth rate) = 0.243 h(-1), Ks (saturation constant) = 25.7 mg/L, and Ki (self-inhibition constant) = 156.3 mg/L. This is the first report of the ability of M. oxydans to degrade phenol, and the results could provide important information for bioremediation of phenol-contaminated environments.

A High-sugar High-fat Diet Induced Metabolic Syndrome Shows some Symptoms of Alzheimer's Disease in Rats

OBJECTIVES

Cases of sporadic Alzheimer's disease (SAD) are the predominant form of the age-related dementia. New evidence suggests that metabolic syndrome (MS), a metabolic disorder, is an initiating factor of some SAD cases. A high-sugar high-fat diet could cause MS, we aimed to investigate whether it could directly lead to SAD.

MEASUREMENTS

The characteristic molecules of AD (hippocampus Aβ and Tau) were tested by using ELISA and western blotting to confirm the happening hallmarks of AD in brain. MS and inflammation related biochemical indicators were measured using immunological method. Proteins associated with the insulin resistance signal pathway (JNK, PI-3K, AKT, GSK-3β, GLUT3) were evaluated using western blotting method. The levels of reactive oxygen species (ROS) were measured by immunofluorescence method.

RESULTS

Expressions of hippocampus Aβ, phosphorylation-Tau (p-Tau), inflammatory factors and p-JNK, Gsk-3βwere higher in the model rats than those in the control rats and expressions of p-PI3K, p-AKT and GLUT3 were reversed.

CONCLUSIONS

The MS model animals, which can induce the characteristics symptoms of AD, and therefore it may be preliminarily considered that the AD pertains to the MS-related diseases.

Revealing the relationship between microbial community structure in natural biofilms and the pollution level in urban rivers: a case study in the Qinhuai River basin, Yangtze River Delta

River pollution is one of the most challenging environmental issues, but the effect of river pollution levels on the biofilm communities has not been well-studied. Spatial and temporal distribution characteristics of environmental parameters and the biofilm communities were investigated in the Qinhuai River basin, Nanjing, China. Water samples were grouped into three clusters reflecting their varying pollution levels of relatively slight pollution, moderated pollution, and high pollution by hierarchical cluster analysis. In different clusters, the biofilm communities mainly differed in the proportion of Actinobacteria, Firmicutes, and Proteobacteria. As the dominant classes of Proteobacteria, Alpha-, Beta- and Gammaproteobacteria seemed to show an upward trend followed by a small fluctuation in the abundance with the escalation of water pollution level. Results of redundancy analysis demonstrated that temperature, total nitrogen to total phosphorus ratios (TN/TP) and concentrations of ammonia nitrogen (NH3-N) and TN were mainly responsible for the variation in bacterial community structure. The occurrences of Alpha-, Beta- and Gammaproteobacteria were closely associated with higher temperature, higher concentrations of NH3-N and TN and a lower TN/TP ratio. This study may provide a theoretical basis for the water pollution control and ecological restoration in urban rivers under different pollution levels.

Paucity of Nanolayering in Resin-Dentin Interfaces of MDP-based Adhesives

Self-assembled nanolayering structures have been reported in resin-dentin interfaces created by adhesives that contain 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). These structures have been hypothesized to contribute to bond durability. The objective of the present study was to determine the extent of nanolayering in resin-dentin interfaces after application of commercialized 10-MDP-containing self-etch and universal adhesives to human dentin. Seven commercialized adhesives were examined: Adhese Universal (Ivoclar-Vivadent), All-Bond Universal (Bisco, Inc.), Clearfil SE Bond 2, Clearfil S3 Bond Plus, Clearfil Universal Bond (all from Kuraray Noritake Dental Inc.), G-Premio Bond (GC Corp.), and Scotchbond Universal (3M ESPE). Each adhesive was applied in the self-etch mode on midcoronal dentin according to the respective manufacturer's instructions. Bonded specimens (n = 6) were covered with flowable resin composite, processed for transmission electron microscopy, and examined at 30 random sites without staining. Thin-film glancing angle X-ray diffraction (XRD) was used to detect the characteristic peaks exhibited by nanolayering (n = 4). The control consisted of 15%wt, 10%wt, and 5%wt 10-MDP (DM Healthcare Products, Inc.) dissolved in a mixed solvent (ethanol and water weight ratio 9:8, with photoinitiators). Experimental primers were applied to dentin for 20 s, covered with hydrophobic resin layer, and examined in the same manner. Profuse nanolayering with highly ordered periodicity (~3.7 nm wide) was observed adjacent to partially dissolved apatite crystallites in dentin treated with the 15% 10-MDP primer. Three peaks in the 2θ range of 2.40° (3.68 nm), 4.78° (1.85 nm), and 7.18° (1.23 nm) were identified from thin-film XRD. Reduction in the extent of nanolayering was observed in the 10% and 5% 10-MDP experimental primer-dentin interface along with lower intensity XRD peaks. Nanolayering and characteristic XRD peaks were rarely observed in specimens prepared from the commercialized adhesives. The sparsity of nanolayering in resin-dentin interfaces created by commercialized adhesives challenges its clinical effectiveness as a mechanism for improving bond longevity in dentin bonding.

Correlation between magnetic resonance perfusion weighted imaging of radiation brain injury and pathology

We used magnetic resonance perfusion weighted imaging and pathological evaluation to examine different stages of radiation-induced brain injury and to investigate the correlation between the relative cerebral blood volume (rCBV) ratio and vascular endothelial growth factor (VEGF). Thirty adult rats were randomly divided into 2 groups: control and radiation group. The control group was not subjected to irradiation. The irradiation group rats were examined by magnetic resonance imaging and magnetic resonance perfusion weighted imaging at 1, 3, 6, 9, and 12 months after radiation treatment. We measured the rCBV, mean transit time, and time to peak. Hematoxylin and eosin staining, immunohistochemical staining, and electron microscopy were performed. VEGF absorbance was evaluated by immunohistochemical staining. Compared with the control group, the differences in rCBV, mean transit time, time to peak, and VEGF absorbance after 3 months were statistically significant (P < 0.05). rCBV was positively correlated with VEGF (r = 0.94, P < 0.05). Magnetic resonance perfusion weighted imaging can reflect pathophysiological changes in brain tissue after irradiation. Decreased expression of VEGF plays a critical role in the pathogenesis of radiation-induced brain injury.

Modeling the Effects of Hydrodynamic Regimes on Microbial Communities within Fluvial Biofilms: Combining Deterministic and Stochastic Processes

To fully understand the effects of hydrodynamics on a microbial community, the roles of niche-based and neutral processes must be considered in a mathematical model. To this end, a two-dimensional model combining mechanisms of immigration, dispersal, and niche differentiation was first established to describe the effects of hydrodynamics on bacterial communities within fluvial biofilms. Deterministic factors of the model were identified via the calculation of Spearman's rank correlation coefficients between parameters of hydrodynamics and the bacterial community. It was found that turbulent kinetic energy and turbulent intensity were considered as a set of reasonable predictors of community composition, whereas flow velocity and turbulent intensity can be combined together to predict biofilm bacterial biomass. According to the modeling result, the bacterial community could get its favorable assembly condition with a flow velocity ranging from 0.041 to 0.061 m/s. However, the driving force for biofilm community assembly changed with the local hydrodynamics. Individuals reproduction within the biofilm was the main driving force with flow velocity less than 0.05 m/s, while cell migration played a much more important role with velocity larger than 0.05 m/s. The developed model could be considered as a useful tool for improving the technologies of water environment protection and remediation.

Observation of Kawasaki disease-related indexes and the study of relationship between myocardial enzyme changes and coronary artery lesions

OBJECTIVE

To discuss the significance of Kawasaki disease-related laboratory indicators and relationship between myocardial enzyme changes and myocardial enzyme changes in children with Kawasaki disease.

PATIENTS AND METHODS

Make an observation of C-reactive proteins and immune globulin changes in children with Kawasaki disease, and also a comparison about the myocardial enzyme changes between the children with myocardial enzyme changes and others without lesions.

RESULTS

Compare the study group before treatment with the control group of normal children, there are significant differences in the levels of CRP, IgG, and IgM, and the difference was statistically significant (p < 0.05); make a comparison about the levels of AST, LDH, CK, HB-DH, and CK-MB in the group with or without coronary artery lesions, the difference was not statistically significant (p > 0.05).

CONCLUSIONS

Relevant laboratory indices play an important role in the early diagnosis of Kawasaki disease. Myocardial injury and coronary artery lesions in children with Kawasaki disease have no correlation between each other, and there has an inconsistency characteristic.

High-speed measurement of rotational anisotropy nonlinear optical harmonic generation using position-sensitive detection

We present a method of performing high-speed rotational anisotropy nonlinear optical harmonic generation experiments at rotational frequencies of several hertz by projecting the harmonic light reflected at different angles from a sample onto a stationary position-sensitive detector. The high rotational speed of the technique, 10(3) to 10(4) times larger than existing methods, permits precise measurements of the crystallographic and electronic symmetries of samples by averaging over low frequency laser-power, beam-pointing, and pulse-width fluctuations. We demonstrate the sensitivity of our technique by resolving the bulk fourfold rotational symmetry of GaAs about its [001] axis using second-harmonic generation.

124 cases of clinical analysis of children with viral myocarditis

OBJECTIVE

A study on clinical characteristics, diagnostic methods of children's viral myocarditis (VMC) and analysis of the effect of VMC is carried out.

PATIENTS AND METHODS

A retrospective analysis of the clinical data of 124 cases of children with VMC from January 2008 to March 2011 in Xuzhou Children's Hospital is conducted.

RESULTS

The age of onset of 1 VMC is less than 1 year old with the majority, fever, precordial pain, and fatigue as the main manifestation, auxiliary examination of abnormal electrocardiogram (ECG) in 110 cases, accounting for 88.71%, the positive rate of dynamic ECG is 92.31%, and abnormal rate of myocardial enzyme examination is 96.77%. The effective rate of treatment is 94.35%, and the effective rate of treatment of creatine phosphate sodium is 100%.

CONCLUSIONS

For childhood, especially 1 year old children with viral infection in clinical, attention should be paid to the VMC performance, suspected children should be timely ECG, dynamic ECG and myocardial enzyme examined with diagnosis and early treatment. The myocardial protection of creatine phosphate sodium has definite therapeutic effect on VMC of children.

Norepinephrine Regulates Condylar Bone Loss via Comorbid Factors

Degenerative changes of condylar subchondral bone occur frequently in temporomandibular disorders. Although psychologic stresses and occlusal abnormalities have been implicated in temporomandibular disorder, it is not known if these risks represent synergistic comorbid factors that are involved in condylar subchondral bone degradation that is regulated by the sympathetic nervous system. In the present study, chronic immobilization stress (CIS), chemical sympathectomy, and unilateral anterior crossbite (UAC) were sequentially applied in a murine model. Norepinephrine contents in the subjects' serum and condylar subchondral bone were detected by ELISA; bone and cartilage remodeling parameters and related gene expression in the subchondral bone were examined. Subchondral bone loss and increased subchondral bone norepinephrine level were observed in the CIS and UAC groups. These groups exhibited decreased bone mineral density, volume fraction, and bone formation rate; decreased expressions of osterix, collagen I, and osteocalcin; but increased trabecular separation, osteoclast number and surface, and RANKL expression. Combined CIS + UAC produced more severe subchondral bone loss, higher bone norepinephrine level, and decreased chondrocyte density and cartilage thickness when compared to CIS or UAC alone. Sympathectomy simultaneously prevented subchondral bone loss and decreased bone norepinephrine level in all experimental subgroups when compared to the vehicle-treated counterparts. Norepinephrine also decreased mRNA expression of osterix, collagen I, and osteocalcin by mesenchymal stem cells at 7 and 14 d of stimulation and increased the expression of RANKL and RANKL/OPG ratio by mesenchymal stem cells at 2 h. In conclusion, CIS and UAC synergistically promote condylar subchondral bone loss and cartilage degradation; such processes are partially regulated by norepinephrine within subchondral bone.

Overexpressed TGF-β in subchondral bone leads to mandibular condyle degradation

Emerging evidence has implied that subchondral bone plays an important role during osteoarthritis (OA) pathology. This study was undertaken to investigate whether abnormalities of the condylar subchondral bone lead to temporomandibular joint (TMJ) OA. We used an osteoblast-specific mutant TGF-β1 transgenic mouse, the CED mouse, in which high levels of active TGF-β1 occur in bone marrow, leading to abnormal bone remodeling. Subchondral bone changes in the mandibular condyles were investigated by micro-CT, and alterations in TMJ condyles were confirmed by histopathological and immunohistochemical analysis. Abnormalities in the condylar subchondral bone, characterized as fluctuant bone mineral density and microstructure and increased but uncoupled activity of osteoclasts and osteoblasts, were apparent in the 1- and 4-month CED mouse groups, while obvious cartilage degradation, in the form of cell-free regions and proteoglycan loss, was observed in the 4-month CED group. In addition, increased numbers of apoptotic chondrocytes and MMP9- and VEGF-positive chondrocytes were observed in the condylar cartilage in the 4-month CED group, but not in the 1-month CED group, compared with their respective age-matched controls. This study demonstrated that progressive degradation of mandibular condylar cartilage could be induced by the abnormal remodeling of the underlying subchondral bone during TMJOA progression.

Effect of bilateral deep brain stimulation of the subthalamic nucleus on freezing of gait in Parkinson's disease

OBJECTIVE

A prospective cohort study to evaluate the efficacy of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) on freezing of gait (FOG) in patients with advanced Parkinson's disease.

METHODS

Patients (n = 10) with advanced Parkinson's disease were surgically implanted with microelectrodes to facilitate STN-DBS. Evaluations of FOG, motor function, activities of daily living and neuropsychological function were carried out in on-medication and off-medication states (with and without levodopa treatment), before surgery and at 6 and 12 months postoperatively.

RESULTS

STN-DBS was associated with significant improvement in FOG score and neuropsychological function at both 6 and 12 months postoperatively, compared with preoperatively. Significant postoperative improvements were also observed in motor function and activities of daily living. Daily levodopa dosage was significantly lower at both 6 and 12 months postoperatively.

CONCLUSIONS

STN-DBS improved FOG in patients with advanced Parkinson's disease. The significant reduction in levodopa dosage and improvement in neuropsychological function may be the reason for the therapeutic effect seen with STN-DBS.

Hypoxic preconditioning attenuates global cerebral ischemic injury following asphyxial cardiac arrest through regulation of delta opioid receptor system

This study was designed to investigate whether delta opioid receptor (DOR) is involved in the neuroprotective effect induced by hypoxic preconditioning (HPC) in the asphyxial cardiac arrest (CA) rat model. Twenty-four hours after the end of 7-day HPC, the rats were subjected to 8-min asphyxiation and resuscitated with a standardized method. In the asphyxial CA rat model, HPC improved the neurological deficit score (NDS), inhibited neuronal apoptosis, and increased the number of viable hippocampal CA1 neurons at 24 h, 72 h, or 7 days after restoration of spontaneous circulation (ROSC); however, the above-mentioned neuroprotection of HPC was attenuated by naltrindole (a selective DOR antagonist). The expression of hypoxia-inducible factor-1α (HIF-1α) and DOR, and the content of leucine enkephalin (L-ENK) in the brain were also investigated after the end of 7-day HPC. HPC upregulated the neuronal expression of HIF-1α and DOR, and synchronously elevated the content of L-ENK in the rat brain. HIF-1α siRNA was used to further elucidate the relationship between HIF-1α and DOR in the HPC-treated brain. Knockdown of HIF-1α by siRNA markedly abrogated the HPC induced upregulation of HIF-1α and DOR. The present study demonstrates that the expression of DOR in the rat brain is upregulated by HIF-1α following exposure to 7-day HPC, at the same time, HPC also increases the production of endogenous DOR ligand L-ENK in the brain. DOR activation after HPC results in prolonged neuroprotection against subsequent global cerebral ischemic injury, suggesting a new mechanism of HPC-induced neuroprotection on global cerebral ischemia following CA and resuscitation.

RU486 (mifepristone) ameliorates cognitive dysfunction and reverses the down-regulation of astrocytic N-myc downstream-regulated gene 2 in streptozotocin-induced type-1 diabetic rats

Diabetic cognitive dysfunction (DCD), usually accompanied with chronically elevated glucocorticoids and hippocampal astrocytic alterations, is one of the most serious complications in patients with type-1 diabetes. However, the role for chronically elevated glucocorticoids and hippocampal astrocytic activations in DCD remains to be elucidated, and it is not clear whether astrocytic N-myc downstream-regulated gene 2 (NDRG2, involved in cell differentiation and development) participated in DCD. In the present study, three months after streptozotocin (STZ)-induced type-1 diabetes onset, rats showed cognitive impairments in Morris water maze test as well as elevated corticosterone level. Diabetic rats also presented down-regulation of glial fibrillary acidic protein (GFAP, a key indicator of astrocytic reactivity) and NDRG2 in hippocampus revealed by immunohistochemistry staining, real-time PCR and Western blot. Moreover, the diabetic cognitive impairments were ameliorated by 9-day glucocorticoids receptor (GR) blockade with RU486, and the down-regulation of hippocampal NDRG2 and GFAP in diabetic animals was also attenuated by 9-day GR blockade. These results suggest that glucocorticoids-GR system is crucial for DCD, and that astrocytic reactivity and NDRG2 are involved in these processes. Thus, inhibiting GR activation in the hippocampus may be a novel therapeutic strategy for treating DCD.