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%.

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.

Effect of adipokine and ghrelin levels on BMD and fracture risk: an updated systematic review and meta-analysis.

Context: Circulating adipokines and ghrelin affect bone remodeling by regulating the activation and differentiation of osteoblasts and osteoclasts. Although the correlation between adipokines, ghrelin, and bone mineral density (BMD) has been studied over the decades, its correlations are still controversial. Accordingly, an updated meta-analysis with new findings is needed. Objective: This study aimed to explore the impact of serum adipokine and ghrelin levels on BMD and osteoporotic fractures through a meta-analysis. Data sources: Studies published till October 2020 in Medline, Embase, and the Cochrane Library were reviewed. Study selection: We included studies that measured at least one serum adipokine level and BMD or fracture risk in healthy individuals. We excluded studies with one or more of the following: patients less than 18 years old, patients with comorbidities, who had undergone metabolic treatment, obese patients, patients with high physical activities, and a study that did not distinguish sex or menopausal status. Data extraction: We extracted the data that include the correlation coefficient between adipokines (leptin, adiponectin, and resistin) and ghrelin and BMD, fracture risk by osteoporotic status from eligible studies. Data synthesis: A meta-analysis of the pooled correlations between adipokines and BMD was performed, demonstrating that the correlation between leptin and BMD was prominent in postmenopausal women. In most cases, adiponectin levels were inversely correlated with BMD. A meta-analysis was conducted by pooling the mean differences in adipokine levels according to the osteoporotic status. In postmenopausal women, significantly lower leptin (SMD = -0.88) and higher adiponectin (SMD = 0.94) levels were seen in the osteoporosis group than in the control group. By predicting fracture risk, higher leptin levels were associated with lower fracture risk (HR = 0.68), whereas higher adiponectin levels were associated with an increased fracture risk in men (HR = 1.94) and incident vertebral fracture in postmenopausal women (HR = 1.18). Conclusions: Serum adipokines levels can utilize to predict osteoporotic status and fracture risk of patients. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021224855, identifier CRD42021224855.

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 of 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 observed 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 need to be studied using various endpoints including growth, reproduction, ingestion, and skin damage and such effects can be different depending on the exposure conditions such as MPs concentration and exposure period.

Factors Associated with Gastrointestinal Symptoms among Rotating Shift Nurses in South Korea: A Cross-Sectional Study.

Rotating shift work places a serious burden on nurses' physical and psychological health. Gastrointestinal (GI) symptoms are a common complaint among shift workers. This study assessed GI symptoms and identified the associations between dietary habits, psychological status, and sleep quality among rotating shift nurses. Data from 125 female nurses in rotating shifts who worked at two tertiary hospitals in South Korea were collected using a questionnaire that included the Gastrointestinal Symptoms Questionnaire; the Dietary Habit Questionnaire; the Depression, Anxiety, Stress Scale (DASS)-21; and the Pittsburgh Sleep Quality Index (PSQI). All participants experienced various GI symptoms, and 47% of them complained of at least one severe GI symptom. There were significant differences in GI symptom scores according to the status of depression, anxiety, stress, and sleep quality. In multiple linear regression analysis, the factors associated with an increase in the occurrence and severity of GI symptoms were poor sleep quality and morbid anxiety and stress. The model explained power at 43.2%. As most nurses in rotating shifts experience GI symptoms, they should receive counseling and training programs at work to alleviate psychological symptoms, improve sleep quality, and pay more attention to their health status as well as GI symptom management.

Effects of oligonol on the submandibular gland in ovariectomized rats.

The aim of this study was to observe the effects of oligonol on submandibular gland dysfunction in ovariectomized rats. We randomly divided female Sprague-Dawley rats into sham-operated, ovariectomized, and oligonol-treated ovariectomized groups. Oligonol was intraperitoneally administered at 30 mg/kg daily for six weeks. Lipogenesis increased after the ovariectomy while fatty acid oxidation increased and intracellular triglyceride levels decreased in response to oligonol treatment. Submandibular gland fibrosis characterized by collagen type I accumulation was observed in the ovariectomized group. However, oligonol markedly reduced fibrosis to a level comparable to that observed in the sham group. Aquaporin 1 and glucose transporter 4 were downregulated in the ovariectomized group. Nevertheless, both factors were significantly upregulated by oligonol treatment. However, aquaporin 5 was significantly downregulated in the oligonol treatment group. Our findings indicate that oligonol protects against damage in postmenopausal rat salivary glands.

Effects of a comprehensive self-management intervention on extraintestinal symptoms among patients with IBS.

OBJECTIVE: Adults with irritable bowel syndrome (IBS) often report extraintestinal pain, fatigue, and sleep disturbances in addition to abdominal pain. Few interventions have sought to reduce these extraintestinal symptoms within the IBS population. To address this, we compared the effects of a comprehensive self-management (CSM) intervention to a control intervention (usual care) on extraintestinal pain, fatigue, and sleep disturbances among patients with IBS. METHOD: Data were obtained from 243 IBS patients participating in two CSM intervention trials. Daily symptom diaries were collected at baseline, 3 and 6 months post-randomization. Daily symptoms of headache, backache, muscle pain, joint pain, fatigue, sleepiness during the day, sleep quality, and refreshed by sleep were analyzed. Analysis of covariance was used to determine the effects of the intervention on each symptom at 3 and 6 months controlling for 'study' and baseline symptom levels. RESULTS: Patients in the CSM intervention group reported decreased symptoms of fatigue, sleep disturbances, backache and headache compared to usual care at 3 and 6 months. The CSM group also reported significantly decreased joint pain at 3 months compared to usual care, but not 6 months. No significant difference was found for muscle pain. CONCLUSIONS: An existing CSM intervention is effective in reducing fatigue and sleep disturbances. However, mixed results for extraintestinal pain indicates a need to better differentiate between underlying mechanisms. Addressing such symptoms is important to decrease the overall burden of IBS, reduce health care expenditures, and improve patients' quality of life. TRIAL REGISTRATION: NCT00907790; NCT00167635.

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 (ΔRrms: -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.

Effects of Cognitive Behavior Therapy on Heart Rate Variability in Young Females with Constipation-predominant Irritable Bowel Syndrome: A Parallel-group Trial.

BACKGROUND/AIMS: The relation between heart rate variability (HRV) as non-invasive biomarkers of autonomic function and cognitive behavior therapy (CBT) as non-pharmacological treatments has rarely been examined in patients with constipation-predominant irritable bowel syndrome (IBS-C). The purpose of this study is to evaluate the efficacy of an 8-week CBT intervention on HRV and IBS symptoms, and the correlation of changes in HRV with changes in IBS symptoms among young female nursing students with IBS-C. METHODS: This study consisted of an exploratory subgroup analysis of 43 participants with IBS-C who had been randomly assigned to receive either 8 weeks of CBT (n = 23) or general medical information (control, n = 20). At baseline and 8, 16, and 24 weeks, participants completed a questionnaire assessing their gastrointestinal (GI) symptoms, anxiety, depression, and stress, and their HRV was measured via electrocardiography. RESULTS: At the 8-week follow-up, the high-frequency (HF) power was significantly higher, and the low-frequency (LF)/HF ratio was lower in the CBT group than in the control group (P < 0.001 for both), and the severity of GI symptoms (P = 0.003), anxiety (P < 0.001), depression (P < 0.001), and stress (P < 0.001) was significantly lower in the CBT group than in the control group. Changes in the HF power were significantly and inversely associated with changes in GI symptoms, anxiety, depression, and stress at 16 and 24 weeks (P < 0.05 for all; range of r from -0.37 to -0.68). Changes in the LF/HF ratio were also significantly and positively associated with changes in GI symptoms, anxiety, depression, and stress at 16 and 24 weeks (P < 0.05 for all; range of r from 0.38 to 0.60). CONCLUSIONS: CBT was effective in managing symptoms in young IBS-C patients and the improvement of symptoms was sustained at 24 weeks following the completion of CBT. Furthermore, indirect measurement of autonomic function using HRV may be a useful objective parameter for assessing response to CBT in young IBS-C patients.

The effects of cognitive behavioral therapy in female nursing students with irritable bowel syndrome: a randomized trial.

BACKGROUND: Irritable bowel syndrome (IBS) is highly prevalent in young women under stressful conditions. Cognitive behavioral therapy (CBT) has been known to be effective in treating IBS. AIMS: This study aimed to evaluate the clinical outcomes of CBT in female nursing students with IBS. The primary outcome measure of the study was the Bowel Symptom Severity Scale-IBS version. PATIENTS AND METHODS: Ninety diagnosed participants were randomized to each group in a randomized pretest-post-test control group design. The experimental group received an 8-week CBT intervention, and the control group received general information on IBS. Bowel symptom severity, dysfunctional attitudes, and IBS-quality of life were assessed at baseline and after 8, 16, and 24 weeks. Six experimental and eight control participants withdrew during the study because of various reasons. RESULTS: Significant effects were found for bowel symptom severity (frequency: P<0.001; distress: P<0.001; disability: P<0.001) between the experimental (n=39) and the control (n=37) groups. The overall IBS-quality of life improved over time in the CBT group (P<0.001). The CBT also showed the alleviation of dysphoria (P=0.010), interference with activity (P=0.031), and health worry (P=0.009), and the improvement of body image (P=0.008) and relationships (P=0.041) compared with the control group. CONCLUSION: CBT proved to be an effective intervention for improving the clinical states of IBS in young female nursing students.

[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.

(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.

[The effects of abdominal meridian massage on menstrual cramps and dysmenorrhea in full-time employed women].

PURPOSE: This study was designed to examine the effects of abdominal meridian(Kyongrak) massage on menstrual cramps and dysmenorrhea. METHOD: Eighty-five women (of 110 screened) enrolled in this study and were employed full-time with more than 6.0 points (in 0-10.0 VAS scale) in menstrual cramps or more than 20 points on the dysmenorrhea scale (range 13-52). The forty-two participants in the experimental group received abdominal meridian massage for 5 minutes per day during 6 days from the fifth day before menstruation to the first day of menstruation and the forty-three participants in the control group didn't receive any treatment. Data were collected from June 1st to August 30th, 2003 and analyzed using descriptive statistics, chi2-test, and t-test. RESULT: Menstrual cramps and dysmenorrhea of the experimental group were significantly lower after abdominal meridian massage than those of the control group (p<.001). CONCLUSION: Abdominal meridian(Kyongrak) massage was very effective for relief of menstrual cramps and dysmenorrhea. Therefore, we suggest that abdominal Kyongrak massage can be a useful nursing intervention for women with menstrual cramps or dysmenorrhea.

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.

[Screening for high risk population of dementia and development of the preventive program using web].

PURPOSE: This study was to develop a screening model for identifying a high risk group of dementia and to develop and evaluate the web-based prevention program. METHOD: It was conducted in 5 phases. 1) Data were collected from dementia patients and non-dementia patients in a community. 2) A screening model of the high risk population was constructed. 3) The validity test was performed and the model was confirmed. 4) Four weeks-prevention program was developed. 5) The program was administered, and evaluated the effects. RESULT: The model consisted of age, illiteracy, history of stroke and hypercholesterolemia. The program was designed with 12 sessions, group health education using web-based individual instruction program, and 12 sessions of low-intensity physical exercise program. After the completion, their self-efficacy, and health behaviors in experimental group were significantly improved over those in the control group. The perceived barrier in the treatment group is significantly decreased. CONCLUSION: The screening model developed is very simple and can be utilized in diverse community settings. And the web based prevention program will encourage individual learning and timely feedback, therefore it can facilitate their active participation and promote health management behaviors at home.