Cs-treatments in Kesterite Thin-Film Solar Cells for Efficient Perovskite Tandems

Cu2ZnSn(S,Se)4 (CZTSSe) thin film solar cells are an attractive choice for a bottom cell of the low-cost and environmental tandem solar cells with perovskite. However, the progress in developing efficient perovskite/CZTSSe tandem solar cells has been hindered by the lack of high performance of the CZTSSe bottom cell. Here, an efficient CZTSSe bottom cell is demonstrated by adopting a facile and effective CsF treatment process. It is found that the CsF treatment not only facilitates grain growth and improves phase homogeneity by suppressing the detrimental deep-level defects and secondary phases, but also induces larger band bending and stronger drift force at the P-N junction. As a result, the carrier extraction/transport can be effectively accelerated, while reducing the interfacial recombination. These combined effects eventually result in a significant performance enhancement from 8.38% to 10.20%. The CsF-treated CZTSSe solar cell is finally applied to the mechanically-stacked perovskite/CZTSSe 4-terminal tandem cell by coupling a semi-transparent perovskite top cell, which exhibits the highest reported tandem efficiency of 23.01%.

Hierarchical Heterogeneous NiFe Layered Double Hydroxides for Efficient Solar-Powered Water Oxidation

Highly active, stable, and low-cost oxygen evolution reaction (OER) electrocatalysts are urgently needed for the realization of large-scale industrial hydrogen production via water electrolysis. Layered double hydroxides (LDHs) stand out as one of the most promising nonprecious electrocatalysts worth pursuing. Here, a hierarchical heterogeneous Ni2+Fe3+@Ni2+Fe2+ LDH was successfully synthesized via a sequential electrodeposition technique using separate electrolytes containing iron precursors with different valence states (Fe2+, Fe3+). The underlying highly crystalline Ni2+Fe2+ LDH nanosheet array provides a large surface for the catalytically more active Ni2+Fe3+ LDH overlayer with low crystallinity. The resulting Ni2+Fe3+@Ni2+Fe2+ LDH demonstrates excellent OER activity with overpotentials of 218 and 265 mV to reach current densities of 10 and 100 mA cm-2, respectively, as well as good long-term stability for 30 h even at a high current density of 500 mA cm-2. In an overall water splitting, an electrolyzer using an electrocatalyst of Sn4P3/CoP2 as a cathode requires only a cell voltage of 1.55 V at 10 mA cm-2. Furthermore, the solar-powered overall water splitting system consisting of our electrolyzer and a perovskite/Si tandem solar cell exhibits a high solar-to-hydrogen conversion efficiency of 15.3%.

Responses of earthworms exposed to low-density polyethylene microplastic fragments

The interest in the effect of microplastics (MPs) on the terrestrial environment has been increasing recently. Different species of earthworms have been used to study the effects of MPs on different aspects of earthworm health. However, there is still a need for more studies because different studies report different effects on earthworms depending on the properties (e.g., types, shapes, sizes) of MPs in the environment and exposure conditions (e.g., exposure period). This study used Eisenia fetida as a test earthworm species to investigate the effect of different concentrations of low-density polyethylene (LDPE) MPs (≤125 μm) in soil on the growth and reproduction of earthworms. The exposure of the earthworms to the different concentrations LDPE MPs (0-3% w/w) for 14 d and 28 d neither caused death of the earthworms nor showed significant effects on the earthworm weights in this study. The number of cocoons produced by the exposed earthworms were also similar to that of the controls (i.e., no exposure to MPs). Some previous studies reported similar results to what have been observe in this study, while some studies reported different results. On the other hand, the number of ingested MPs by the earthworms increased with increasing MPs concentrations in soil, suggesting a potential for damage to digestive tract. Also, the earthworm skin surface was damaged after exposure to MPs. The ingested MPs and the skin surface damage suggest that there is a potential for adverse effects on the earthworm growth after a longer-term exposure. Overall, the results of this study show that the effects of MPs on earthworms can be different depending on the properties of MPs and exposure conditions.

Characterization of various tandem solar cells: Protocols, issues, and precautions

In the search for a more efficient solar cell, various types of tandem solar cells (TSCs) have been actively developed worldwide as the performances of the single junction solar cells approach their theoretical limits. Meanwhile, various materials and structures are adopted in TSCs, which makes their characterizations and comparison difficult. Along with the classical monolithic TSC, which exhibits two electrical contacts, devices with three or four electrical contacts have been widely studied as a more performing alternative of commercialized solar cells. For a fair and accurate evaluation of the device performance of TSCs, understanding the effectiveness and limitations of the characterization of the different types of TSCs is crucial. In this paper, we summarize various types of TSCs and discuss their characterization methods.

A Thin In2 S3 Interfacial Layer for Reducing Defects and Roughness of Cu2 ZnSn(S,Se)4 Thin-Film Solar Cells

Cu₂ ZnSn(S,Se)₄ (CZTSSe) has generated considerable research interest owing to its composition of abundant elements and excellent light-absorption properties. However, CZTSSe thin-film solar cells suffer from a considerable deficit in the open-circuit voltage (V_OC ), which is mainly due to the severe interfacial recombination induced by the rough surface of CZTSSe and numerous physical defects. In this study, to improve the morphology and reduce the interfacial recombination, an In₂ S₃ passivation layer was introduced between the CZTSSe and CdS layers via a chemical bath deposition process, and the effects of the In₂ S₃ layer on the device performance were systematically examined by performing various electrodynamic analyses. The CZTSSe solar cells with thin In₂ S₃ layers exhibited impressive increases in V_OC and conversion efficiency (from 7.33 to 9.24 %), due to the suppression of physical defects and the refined surface morphology resulting from filling the voids and pinholes. In addition, the nanoscale roughness of the In₂ S₃ /CZTSSe surface increased the number of nucleation sites for the CdS nuclei, which may reduce the activation energy of the heterogeneous nucleation. The presence of In₂ S₃ layer resulted in uniform growth of CdS without macroscopic CdS agglomerates (i. e., reduced roughness of full devices), which improved the quality of the interface. These findings confirmed that the reduction of physical defects and the improved deposition of the CdS layer enabled by the added In₂ S₃ passivation layer improved the device performance.

Roughness-Controlled Cu2ZnSn(S,Se)4 Thin-Film Solar Cells with Reduced Charge Recombination

Copper zinc tin sulfo-selenide (CZTSSe) is a promising light-absorbing material of thin-film solar cells because of its low material cost especially when it is prepared by cost-effective processes like the electrochemical deposition process. The CZTSSe thin-film solar cells, however, suffer from the relatively low efficiency, mostly because of the significant charge recombination. Given that the surface recombination is one of the major recombination paths, controlling the surface roughness, and thus the interfacial area is one of the key factors for improving their device performances. In this study, we demonstrated a simple but effective strategy for reducing the surface roughness during the electrochemical deposition process of the CZTSSe thin films. By adopting an initial nucleation stage with higher deposition currents ahead of the steady-state galvanostatic deposition, the surface of the copper-zinc-tin (CZT) precursor and CZTSSe thin films became significantly smoother and uniform (ΔR_rms: -43.8% for CZT, -28.9% for CZTSSe). The effects of the surface roughness on the photovoltaic properties of the CZTSSe thin-film solar cells have been investigated systematically with various characterization techniques like the diode analysis, lifetime measurement, and the temperature dependency of the open-circuit voltage. The device with the smoother surface exhibited higher open-circuit voltage and fill factor, mostly because of the significantly reduced charge recombination, leading to the high conversion efficiency of 8.64% (active).

Heavy metal and sulfate removal from sulfate-rich synthetic mine drainages using sulfate reducing bacteria

The removals of heavy metals and sulfate in the synthetic acid mine drainages (AMDs) by Desulfovibrio desulfuricans, sulfate-reducing bacteria (SRB), and the indigenous bacteria isolated from the mine area soil sample were studied to compare the AMD treatment efficiencies. The AMD treatment by the D. desulfuricans grown in the Desulfovibrio medium was used to represent bioaugmentation, while the AMD treatment by the indigenous bacteria grown in the Desulfovibrio medium was used to represent biostimulation. The consumption of lactate and sulfate suggested that the zinc (Zn) removal in the Zn-spiked Desulfovibrio medium by D. desulfuricans involved chemical precipitation and biosorption. The complete Zn removal by D. desulfuricans took 24 h, while the indigenous bacteria took 360 h. The significantly lower rate can probably be attributed to the composition of the culture. The removal of Zn in the sulfate-rich synthetic AMD-containing Desulfovibrio medium (i.e., AMD) was adversely affected by the presence of other heavy metals. Also, the sulfate reduction by D. desulfuricans and the indigenous bacteria was reduced from 47% to 20% and from 36% to 6%, respectively. The inhibitive effects on the removal of heavy metals and sulfate were greater with the Zn/Cu-spiked AMD than the Zn-spiked AMD. Overall, the indigenous bacteria showed potential for removing heavy metals and sulfate in AMDs, while the removal efficiency was lower than D. desulfuricans. The continuous supply of carbon sources with an adaptation period may be required to enhance the AMD treatment efficiency by the indigenous bacteria.

Predictors of failure to detect early hepatocellular carcinoma in patients with chronic hepatitis B who received regular surveillance

BACKGROUND

A proportion of chronic hepatitis B (CHB) patients are diagnosed with advanced hepatocellular carcinoma (HCC) despite regular surveillance.

AIMS

To determine predictors for HCC detection failure in CHB patients who underwent regular surveillance.

METHODS

CHB patients with well-preserved liver function, who underwent ultrasonography and alpha-foetoprotein (AFP) analysis every 6 months, were enrolled. Cox regression analysis was used to identify predictors for detection failure, defined as HCC initially diagnosed at Barcelona Clinic Liver Cancer (BCLC) stage B or C.

RESULTS

Of the 4590 CHB patients (mean age, 52.1 years; men, 61.6%), 169 patients were diagnosed with HCC (3.68%) and 35 (20.7%) HCC patients were initially diagnosed with HCC BCLC stage B or C. The cumulative incidence of HCC detection failure was 0.2% at year 1 and 1.3% at year 5. Multivariate analyses indicated that cirrhosis (hazard ratio [HR], 3.078; 95% CI, 1.389-6.821; P = 0.006), AFP levels ≥9 ng/mL (HR, 5.235; 95% CI, 2.307-11.957; P = 0.010), and diabetes mellitus (HR, 3.336; 95% CI, 1.341-8.296; P = 0.010) were independent predictors of HCC detection failure. Another model that incorporated liver stiffness (LS) values identified LS values ≥11.7 kPa (HR, 11.045; 95% CI, 2.066-59.037; P = 0.005) and AFP levels ≥9 ng/mL (HR, 4.802; 95% CI, 1.613-14.297; P = 0.005) as predictors of detection failure.

CONCLUSIONS

In CHB patients undergoing regular surveillance with ultrasonography and alpha-foetoprotein (AFP) analysis every 6 months, the HCC detection failure rate was not high (0.8% per person; 0.1% per test). However, careful attention should be paid in patients with advanced liver fibrosis (clinical cirrhosis or LS value >11.7 kPa), high AFP levels, or diabetes mellitus, who are prone to surveillance failure.

Exposure to fine particulate matter associated with senile lentigo in Chinese women: a cross-sectional study

BACKGROUND

Skin ageing especially senile lentigo directly affects self-esteem. For decades, senile lentigo has been associated with chronic exposure to solar radiation. However, a study conducted recently in Caucasian subjects suggested that exposure to air pollution was significantly correlated with extrinsic skin ageing, in particular senile lentigines.

OBJECTIVE

To investigate the association between fine particulate matter (PM_2.5 ) and skin ageing, particularly senile lentigo and seborrheic keratosis.

METHODS

The study enrolled 400 Chinese women aged 40-90 years including 210 from the Yanqing county in Beijing (low PM_2.5 exposure group) and 190 from the Xuanwumen in Beijing (high PM_2.5 exposure group). Skin ageing symptoms, particularly senile lentigines and seborrheic keratoses, were clinically assessed using scores of intrinsic and extrinsic skin ageing. An ordinal logistic regression model was used to analyse the effect of PM_2.5 on skin ageing adjusted for factors underlying skin ageing.

RESULTS

In the study population of Xuanwumen, we found that senile lentigo on cheeks and back of hands was 1.48 times and 2.8 times higher, respectively, compared with those from Yanqing county. However, no association was found between PM_2.5 and seborrheic keratosis. We found that other variables such as smoking, second-hand smoking, contact with fossil fuels and skin types were significantly associated with skin ageing.

CONCLUSION

These results indicate that PM_2.5 was another extrinsic factor promoting skin ageing.

[A structural equation modeling on premenstrual syndrome in adolescent girls]

PURPOSE

The aims of this study were to construct a hypothetical structural model which explains the premenstrual syndrome (PMS) in adolescent girls and to test the fitness with collected data.

METHODS

The participants were 1,087 adolescent girls from 3 high schools and 5 middle schools in B city. Data were collected from July 3 to October 15, 2012 using self-reported questionnaires and were analyzed using PASW 18.0 and AMOS 16.0 programs.

RESULTS

The overall fitness indices of hypothetical model were good (χ² =1555, p<.001), χ²/df=4.40, SRMR=.04, GFI=.91, RMSEA=.05, NFI=.90, TLI=.91, CFI=.92, AIC=1717). Out of 16 paths, 12 were statistically significant. Daily hassles had the greatest impact on PMS in the adolescent girls in this model. In addition, PMS in adolescent girls was directly affected by menarche age, Body Mass Index (BMI), amount of menstruation, test anxiety, social support, menstrual attitude and femininity but not by academic stress. This model explained 27% of the variance in PMS in adolescent girls.

CONCLUSION

The findings from this study suggest that nursing interventions to reduce PMS in adolescent girls should address their daily hassles, test anxiety, menstrual attitude and BMI. Also, social support from their parents, friends, and teachers needs to be increased.

Effects of guar gum ingestion on postprandial blood pressure in older adults

OBJECTIVES

The aim of this study was to investigate the effects of guar gum on postprandial blood pressure in older people.

DESIGN

A randomized, double-blind, placebo-controlled, cross-over design.

SETTING

Community senior centers in B city, South Korea.

PARTICIPANTS

Twenty-two older female adults aged 67 to 88 with postprandial hypotension.

INTERVENTION

The participants were randomly assigned to guar gum (semi-fluid food with 9 gram) or placebo intervention during the first treatment phase. After a washout period of 1 week, the two interventions were switched to the other in the second treatment phase.

MEASUREMENTS

Blood pressure was measured during both phases before having a meal and every 15 minutes during 120 minutes after a meal with automated sphygmomanometer.

RESULTS

Change in systolic blood pressure (SBP) over time was significantly different between guar gum and placebo groups (F=4.07, p=0.001). Compared with placebo group, guar gum group had significantly low prevalence of postprandial hypotension (PPH) (guar gum group=18.2% vs. placebo group=72.7%; χ² =13.20, p<0.001). It also had significant difference in change of diastolic blood pressure (DBP) over time between guar gum and placebo groups (F=2.49, p=0.027).

CONCLUSION

This findings show that guar gum could be effective on postprandial drops in blood pressure in older female adults.

The frequency and impact of ROS1 rearrangement on clinical outcomes in never smokers with lung adenocarcinoma

BACKGROUND

To determine the frequency and predictive impact of ROS1 rearrangements on treatment outcomes in never-smoking patients with lung adenocarcinoma.

PATIENTS AND METHODS

We concurrently analyzed ROS1 and ALK rearrangements and mutations in the epidermal growth factor receptor (EGFR), and KRAS in 208 never smokers with lung adenocarcinoma. ROS1 and ALK rearrangements were identified by fluorescent in situ hybridization.

RESULTS

Of 208 tumors screened, 7 (3.4%) were ROS1 rearranged, and 15 (7.2%) were ALK-rearranged. CD74-ROS1 fusions were identified in two patients using reverse transcriptase-polymerase chain reaction. The frequency of ROS1 rearrangement was 5.7% (6 of 105) among EGFR/KRAS/ALK-negative patients. Patients with ROS1 rearrangement had a higher objective response rate (ORR; 60.0% versus 8.5%; P = 0.01) and a longer median progression-free survival (PFS; not reached versus 3.3 months; P = 0.008) to pemetrexed than those without ROS1/ALK rearrangement. The PFS to EGFR-tyrosine kinase inhibitors in patients harboring ROS1 rearrangement was shorter than those without ROS1/ALK rearrangement (2.5 versus 7.8 months; P = 0.01).

CONCLUSIONS

The frequency of ROS1 rearrangements in clinically selected patients is higher than that reported for unselected patients, suggesting that ROS1 rearrangement is a druggable target in East-Asian never smokers with lung adenocarcinoma. Given the different treatment outcomes to conventional therapies and availability of ROS1 inhibitors, identification of ROS1 rearrangement can lead to successful treatment in ROS1-rearranged lung adenocarcinomas.

(5-Arylfuran-2-ylcarbonyl)guanidines as Cardioprotectives through the Inhibition of Na+/H+ Exchanger Isoform-1

A series of (5-arylfuran-2-ylcarbonyl)guanidines was synthesized and evaluated for the NHE-1 inhibitory activity and cardiprotective efficacy against ischemia-reperfusion injury. Starting with (5-phenylfuran-2-ylcarbonyl)guanidine 47 with a moderate inhibitory effect on NHE-1, the compounds with various substituents at the phenyl ring were investigated with the aim to optimize the potency. In this study, the 2,5-disubstituted compounds appeared to have better activities than the other analogues, and the 2-methoxy-5-chlorophenyl compound 85 was found as a potent inhibitor of NHE-1 (IC(50) = 0.081 microM). Furthermore, 85 showed a marked reduction of infarct size in the rat myocardial infarction model in vivo and significant improvement of cardiac contractile function in the isolated rat heart ischemia model in vitro.

Effects of body position and time after feeding on gastric residuals in LBW infants

PURPOSE

To examine the effects of body position and time after feeding on gastric residuals in low birth weight infants(LBW).

METHODS

A repeated measures design was conducted. Twenty LBW infants being fed via indwelling nasogastric tubes were randomly assigned to one of 5 different position orderings. In each position, gastric residuals were measured at 30, 60, 90, 120, 150, and 180 minutes after feeding.

RESULTS

In comparisons of gastric residuals with position and time, the main effects of position and time were statistically significant (F = 5.038, p = 0.001; F = 429.763, p < 0.001, respectively), but the interaction between position and time was found not to be significant. In pairwise comparisons, the gastric residuals were more reduced in the right anterior oblique and prone positions compared with the left lateral position (p < 0.05) and the differences across time periods were significant (p < 0.001).

CONCLUSIONS

The body position after feeding has a significant affect on gastric residuals over time in LBW infants. The right anterior oblique or prone position is recommended rather than left lateral position after feeding. Knowledge of the proper position and the pattern of gastric emptying over time after feeding may lead to the development of evidence-based nursing care.

Molecular cloning and expression analysis of 3-ketoacyl-ACP synthases in the immature seeds of Perilla frutescens

We report the isolation and expression analysis of two cDNAs encoding 3-ketoacyl-acyl carrier protein synthases (KAS) that are involved in the de novo synthesis of fatty acids in plastids of perilla (Perilla frutescens L.). The cDNAs, designated PfFAB1 and PfFAB24, encoded polypeptides with high sequence identities to those of KAS I and KAS II/IV, respectively, of various plants. Genomic Southern blots revealed that there was a single PfFAB1 gene but two PfFAB24 genes in the perilla genome. Of interest is that the expression of both genes was developmentally regulated in seeds. Their mRNA expression patterns in seeds were also discussed in comparison with the profile of fatty acid accumulation.

Infantile head injury, with special reference to the development of chronic subdural hematoma

An infantile head injury has unique features in that infants are totally helpless and dependent on their parents, and biomechanical characteristics of the skull and brain are very different from those of other age groups. The authors reviewed a total of 16 infant head injury patients under 12 months of age who were treated in our hospital from 1989 to 1997. Birth head injury was excluded. The most common age group was 3-5 months. Early seizures were noted in 7 cases, and motor weakness in 6. Three patients with acute intracranial hematoma and another 3 with depressed skull fracture were operated on soon after admission. Chronic subdural hematomas (SDHs) developed in 3 infants. Initial CT scans showed a small amount of SDH that needed no emergency operation. Resolution of the acute SDH and development of subdural hygroma appeared on follow-up CT scans within 2 weeks of injury. Two of these infants developed early seizures. Chronic SDH was diagnosed on the 68th and 111th days after the injuries were sustained, respectively. The third patient was the subject of close follow-up with special attention to the evolution of chronic SDH in view of our experience in the previous 2 cases, and was found to have developed chronic SDH on the 90th day after injury. All chronic SDH patients were successively treated by subduro-peritoneal shunting. In conclusion, the evolution of chronic SDH from acute SDH is relatively common following infantile head injury. Infants with head injuries, especially if they are associated with acute SDH and early development of subdural hygroma, should be carefully followed up with special attention to the possible development of chronic SDH

Molecular cloning and functional expression of Perilla frutescens 3-ketoacyl-(acyl carrier protein) synthase III

The 3-ketoacyl-acyl carrier protein synthase III (KAS III) is a condensing enzyme catalyzing the initial step of fatty acid biosynthesis. We isolated two KAS III cDNA isoforms (PfKAS3a and PfKAS3b) from a cDNA library specific to Perilla frutescens immature seeds. Two cDNAs coded for 401 and 400 amino acids, respectively, which showed high degree of sequence similarity to corresponding enzymes from various sources. Results of Southern hybridization indicated that the PfKAS3a gene is present as two copies, whereas the PJKAS3b gene is a single copy. While both genes were equally expressed in high levels during early stages of seed maturation in a development-specific manner, the PfKAS3b transcript showed more prolonged appearance. Expression of the functional recombinant perilla KAS III increased the myristate level in E. coli but it exerted no appreciable effect on cell growth.

Noise-induced chaos in an optically injected semiconductor laser model

The chaos induced by an intrinsic spontaneous-emission noise in an optically injected semiconductor laser is investigated through a single-mode injection model. A method is developed to quantitatively study the scale-dependent noise effect in general, and the noise-induced chaotic feature in particular. We find that noise at an experimentally measured level can induce chaos in the system. This suggests that noise-induced chaos may indeed exist in real systems. Certain required characteristics for noise to induce chaos are identified: the periodic state itself, when subject to weak noise, should undergo a process that is much more diffusive than the Brownian motion, and the adjacent chaotic states should still behave chaotically on certain finite scales when subject to noise. We believe they are generic features for noise to induce chaos. The correlation dimension of the clean and noisy attractors is also calculated to study noise-induced changes in the geometrical structure of the attractors.

Soft drugs. 12. Design, synthesis, and evaluation of soft bufuralol analogues

In the search for more potent but still short-acting beta-blockers (BB), the methyl, ethyl, isopropyl, tert-butyl, cyclohexyl, 2-(1-adamantyl)ethyl, and methylthiomethyl esters of the acidic inactive metabolite of bufuralol were synthesized based on the "inactive metabolite" approach. The cleavage of the ester bond by blood and tissue esterases rapidly deactivates these compounds, resulting in an ultrashort duration of action. The beta-antagonist potencies and time courses of actions of the new "soft" BBs were characterized by recording ECG and intra-arterial blood pressure (BP) in rats. In the isoproterenol-induced tachycardia model, while bufuralol at an iv dose of 1 mg/kg (3.8 micromol/kg) diminished heart rate (HR) for at least 2 h, the effects of the soft drugs lasted for only 10-30 min at equimolar dose. The inactive metabolite did not decrease HR significantly. The first four members of this series of compounds showed the highest beta-blocking potencies, ranging between 25% and 50% of that of bufuralol. Next, the effects of these most active compounds on resting HR and BP were evaluated in comparison to esmolol. Infused for 10 min at a rate of 20 micromol/kg/min, esmolol decreased HR and mean arterial pressure (MAP) by 40% and 60%, respectively. The soft drugs at doses ranging only between 2 and 4 micromol/kg/min resulted in a 20-40% decrease in HR and a 30-50% reduction in MAP. However, the time courses of both the bradycardic and hypotensive effects of the soft drugs were superimposable to that of esmolol, diminishing within 60 min after the discontinuation of the infusions.

Secondary structural and phylogenetic implications of nuclear large subunit ribosomal RNA in the ectomycorrhizal fungus Tricholoma matsutake

The sequence of large subunit (LSU) and 5.8S rRNA genes has been determined for Tricholoma matsutake. A secondary structure model was predicted for both LSU and 5.8S rRNAs, showing most of the structural features consistent with those of the consensus secondary structure model proposed for the eukaryotic cytoplasmic LSU rRNAs. With a reconstructed eukaryotic phylogeny based on full-length LSU rDNA sequences, T. matsutake was placed on the same branch with Cryptococcus neoformans as its closest neighbor. We proposed that T. matsutake be considered as one of the representative members of the division Basidiomycota. Here we report for the first time the complete LSU rRNA gene sequence in T. matsutake, a member of Homobasidiomycetes.

Syntheses and cytotoxicities of four stereoisomers of muricatacin from D-glucose

Four stereoisomers of muricatacin 1a-d were prepared by the reaction of corresponding aldehydes 4a-d, which in turn were prepared from D-glucose, with the anion of triethylphosphonoacetate followed by reduction and cyclization under acidic conditions. Cytotoxicities of four stereoisomers were tested against in vitro A-549 cell line as well as MCF-7 cell line. Stereochemistry at C4 and C5 position of muricatacin did not affect the cytotoxicities significantly.

Small-subunit ribosomal DNA of an ectomycorrhizal fungus tricholoma matsutake: sequence, structure and phylogenetic analysis

A 2861 bp nucleotide sequence containing Tricholoma matsutake SSU rRNA gene and its flanking regions was determined and analyzed. Comparison with known SSU rDNA sequences and primer extension analysis revealed that the SSU rRNA coding region and intergenic spacer 2 (IGS2) are 1805 bp and 1043 bp in length, respectively. The IGS2 has an imperfect direct repeat (type 1) homologous to the region downstream to the 5S rRNA gene and the three imperfect tandem direct repeats (type 2) upstream to the SSU rRNA-encoding sequence. Structural analysis by a comparative method showed that the overall secondary structure of the SSU rRNA is generally similar to that of S. cerevisiae, whereas the secondary structures of the V4 regions predicted by the thermodynamics-based method showed different configurations between distantly related taxa, implying that these structural differences can provide phylogenetically informative features. Phylogenetic trees based on both the aligned SSU rRNA sequences with almost full-length sequences and V4 sequences revealed that T. matsutake is very closely related to other basidiomycetes belonging to Agaricales. Thus we propose that the V4 region is also a good source for the inference of phylogeny to support the SSU rRNA phylogeny.

Prolonged ethanol intake increases D2 dopamine receptor expression in the rat brain

Dopamine via interaction with its receptor is known to be involved in the behavioral and endocrine actions in the mammalian brain. Behavioral effects produced by ethanol appear to be due to its actions on the dopaminergic system. In the present study using in situ hybridization histochemistry and RNase protection assay, the effect of prolonged ethanol intake on the expression of D2 dopamine receptor mRNA was examined in the rat brain. Specific D1 and D2 receptor mRNA signals were detected in the caudate putamen, nucleus accumbens, olfactory tubercle, hippocampus, dentate gyrus, and amygdaloid complex of the rat brain. Within the hypothalamus, the level of receptor mRNA was low in most nuclei with a somewhat higher level in the arcuate nucleus. Only the supurachiasmatic nucleus showed moderate to dense dopamine receptor mRNAs. Prefrontal cortex showed hybridization signals but their intensity was very low. A considerable amount of D2 mRNA was localized in the substantia nigra but D1 mRNA was not. Ethanol (10%) intake for 5 weeks increased both the density of hybridization signal and number of cells expressing D2 dopamine receptor mRNA in the caudate putamen, and nucleus accumbens, but not in the olfactory tubercle. RNase protection assay revealed about a 1.5-fold increase in the D2 dopamine receptor mRNA level in the corpus striatum. These results provide a basis for the involvement of dopamine D2 receptor expression in alcoholism.

Cementless total hip arthroplasty with AML, PCA and HGP prostheses

Two hundred and fourteen patients who had 270 cementless hip prostheses were followed for 2 to 8 years. PCA (Porous-Coated Monatomic), AML (Monatomic Medullary Locking) and HGP (Harris-Galante-Porous) femoral stems and acetabular cups were used without any preference for the prostheses. The overall clinical results were similar for the three prostheses with average Harris hip scores of 93, 93 and 91 respectively. Four PCA prostheses had radiological aseptic loosening and one was revised because of polyethylene wear. There was no loosening in the AML and HGP prostheses. Pain in the thigh, usually slight, occurred in 17% of AML, 21% of PCA and 19% of HGP prostheses. Five years after operation, radiological changes such as migration, calcar remodelling and radiolucent lines were the same for the 3 prostheses, but bony ingrowth was greater with the AML femoral stems.

Growth hormone replacement therapy in adults with growth hormone deficiency; thrice weekly low dose administration

Recent reports on growth hormone (GH) therapy have shown that GH has various beneficial effects in GH deficient adults. In most of these studies, GH was administered daily. Because GH is still expensive and has to be delivered by subcutaneous injection, we studied the 6-month therapeutic effects of thrice weekly GH injection therapy and compared it with daily therapy. Twenty eight adult patients with GH deficiency were randomly assigned into group 1 (ten cases, thrice weekly injections of GH), group 2 (nine cases, daily injections), and group 3 (nine cases, placebo injections). Lean body mass, serum basal GH levels, and insulin-like growth factor 1 levels significantly increased after six months of GH therapy in both groups 1 and 2. According to computed tomography, the mean mid-thigh muscle mass significantly increased in group 1, while the visceral fat mass significantly decreased in group 2. GH levels significantly increased exercise rate-pressure product and hand grip strength only in group 1. These results suggest that thrice weekly injections of GH are as effective as daily injections in GH deficient adults.

Vascular injury during total hip arthroplasty: the anatomy of the acetabulum

We encountered a massive retroperitoneal haemorrhage due to perforation of the external iliac vein by a drill tip passing through the antero-superior quadrant of the acetabulum during cementless total hip arthroplasty. An anatomical study of the acetabulum was undertaken to determine the safe zones for transacetabular screw fixation. Five cadavera were studied to find the proper locations for screws using acetabular quadrants. The postero-superior and postero-inferior acetabular quadrants have good bone stock and are safe for the transacetabular replacement of screws. The antero-superior and inferior quadrants should be avoided. Screws placed in these quadrants may damage the external iliac artery and vein or the obturator vessels.

[Evaluation of radiation doses in mammography]

A dedicated X-ray mammography was introduced to our hospital from 1987 and an imaging receptor of xeroradiography was applied. We reported previously that the average air exposure was 0.79R and that the absorption dose of skin was 1.00 rad. These data are similar to literature reports. Screen-film mammography was introduced recently. To select the best breast imaging and the least radiation exposure, diverse methods were investigated. A dosimetry (Capintec model 192) and a PS-033 parallel ionization chamber were applied to compare the absorption dose on polystyrene phantom between various exposure factors, the application of breast clamp and the size of exposure field. Retrospective estimation of the radiation dose was obtained from the exposure factors of previous mammography since July, 1990 to May, 1992. There were 1035 xeromammographic examinations and 358 examinations with medium-speed screen-film mammography. Another 61 craniocaudal and 96 mediolateral projections with high-speed screen-film mammography were recruited during the recent two months. An ionization chamber (Exradin, Shonka-Wyckoff A5) with an electrometer (Keithley 617) wer selected to obtain the dose equivalent from air exposure between selected exposure factors. The radiation dose of mammography is linearly correlated with voltage/kV and current/mAs. The application of a breast clump reduces 10% of the skin dose. The average exposure factors of xeromammography are 45.6 kV, 163.5 mAs. These results remain the same as in our previous report. Xeromammography has a greater exposure to air, estimated average glandular dose and absorbed dose than screen-film mammography. The mean exposure factor of rapid screen-film mammography gains half the value of medium screen-film mammography, ie. 26.6 kV, 87.0 mAs vs. 26.0 kV, 164.5 mAs.(ABSTRACT TRUNCATED AT 250 WORDS)

Cementless total hip arthroplasty with PCA prosthesis

Eighty-one cases of cementless porous-coated total hip arthroplasties in 74 patients were analyzed. Hip rating scores as described by Harris were used, and AP and lateral radiographs were made serially: preoperatively, 3 months, 6 months, 1 year, and 2 years postoperatively. The average postoperative hip rating score was 91 points (range: 76 to 100 points) at 1 year and 93 points (range: 74 to 100 points) at 2 years. The overall clinical results were satisfactory in these patients at both 2 and 4 years. However, slight to mild thigh pain was observed in 16 (19.8%) of 81 hips at 2 years, and 10 (21.3%) of 47 hips at 4 years postoperatively. Moderate to severe limp was seen in 11 (13.6%) of 81 hips at 2 years and seven (14.9%) of 47 hips at 4 years postoperatively.

Induction of osteochondromas by periosteal resection

Forty immature and 40 mature rabbits which received periosteal resection from the proximal metaphyses or diaphyses of tibiae were evaluated for the occurrence of osteochondromas at the sites of periosteal defects. Thirteen of 20 immature tibiae with the periosteal defects at their proximal metaphyses showed osteochondromas covered by hyaline cartilage caps. We assume that the occurrence of osteochondroma at the metaphyseal region of growing long bone, where the periosteal defects were made, is due primarily to a decrease in the power of the periosteum to control the circumferential growth of the metaphysis, and is due secondarily to an abnormal proliferation of cartilage progenitors located in Ranvier's groove.

Changes of cardiac output during treadmill exercise by impedance cardiography

Nine athletes and ten nonathletes were selected randomly to study the changes of cardiac function during exercise by impedance cardiography. The speed of the treadmill was maintained at 3.4 mph, and its grade was increased by 1% (Balke protocol). The exercise was continued until the target heart rate (THR), 85% of maximum oxygen uptake (VO2max). The measured parameters for pre- and post-exercise were stroke volume (SV), heart rate (HR), and cardiac output (CO). Average stroke volume of athletes at pre-exercise, 71.1 ml, was higher than that of nonathletes, 64.6 ml, and stroke volume of the former at post-exercise, 97.0 ml, was also higher than that of the latter, 85.2 ml. Therefore, despite the lower heart rate, cardiac outputs of athletes at pre- and post-exercise, 4.98 and 16.3 L/min, were higher than those of nonathletes, 4.87 and 14.2 L/min. For the second phase of the study, cardiac outputs of three subjects were measured during the continuous treadmill exercise with newly developed electrodes and shoes for minimizing motion artifact. Though there were several studies measuring cardiac output during continuous bicycle exercise, this is thought to be the first study in the world measuring cardiac output during continuous treadmill exercise without aid of ensemble averaging.

Effects of ketamine on contractile responses in vascular smooth muscle

This study was designed to determine the effects of ketamine on contractions induced by norepinephrine (NE), K+ or histamine (Hist) and on agonist-induced calcium mobilization, in rabbit thoracic aorta with or without endothelium. Contractile responses to NE, K+ or Hist were markedly attenuated by prior exposure to ketamine. Subsequent addition of ketamine to the rabbit aorta undergoing an isometric contraction induced by NE, K+ or Hist also decreased the contractile responses in a calcium ion concentration-dependent manner. Preincubation with ketamine produced a concentration-dependent inhibition of contractile responses elicited by the addition of calcium ion (1.6 mM) to a Ca(++)-free depolarizing solution. However, the phasic contraction produced by NE with 2mM lanthanum pretreatment, which is release of intracellular calcium, was also inhibited by ketamine. Moreover, the tonic contraction produced by NE after depletion of the agonist-releasable pool of intracellular calcium, which is thought to be due to calcium influx, was depressed by ketamine. These data suggest that ketamine relaxes NE-contracted rings of rabbit thoracic aorta by decreasing calcium entry and by producing an extracellular calcium-independent relaxant effect.

Orderly stimulation of skeletal muscle motor units with tripolar nerve cuff electrode

An electrical nerve stimulation technique, using single tripolar electrode, was shown to be capable of recruiting motor units according to their size, while allowing simultaneous but independent control of firing rate in the active units. Test paradigms consisting of established fundamental physiological concepts of soleus-gastrocnemius architecture, motor units conduction velocity, firing rate behavior of motor units of different sizes, and their susceptibility to fatigue were employed to validate the technique and demonstrate its utility as a basic and applied research tool.