Flexible solar cells based on foldable silicon wafers with blunted edges.

Flexible solar cells have a lot of market potential for application in photovoltaics integrated into buildings and wearable electronics because they are lightweight, shockproof and self-powered. Silicon solar cells have been successfully used in large power plants. However, despite the efforts made for more than 50 years, there has been no notable progress in the development of flexible silicon solar cells because of their rigidity1-4. Here we provide a strategy for fabricating large-scale, foldable silicon wafers and manufacturing flexible solar cells. A textured crystalline silicon wafer always starts to crack at the sharp channels between surface pyramids in the marginal region of the wafer. This fact enabled us to improve the flexibility of silicon wafers by blunting the pyramidal structure in the marginal regions. This edge-blunting technique enables commercial production of large-scale (>240 cm2), high-efficiency (>24%) silicon solar cells that can be rolled similarly to a sheet of paper. The cells retain 100% of their power conversion efficiency after 1,000 side-to-side bending cycles. After being assembled into large (>10,000 cm2) flexible modules, these cells retain 99.62% of their power after thermal cycling between -70 °C and 85 °C for 120 h. Furthermore, they retain 96.03% of their power after 20 min of exposure to air flow when attached to a soft gasbag, which models wind blowing during a violent storm.

Teaching environmental health in primary and secondary schools in Shanghai and its association with screening myopia applying multilevel models / 中国学校卫生

Objective@#To understand the status of teaching environmental health in primary and secondary schools and explore its association with myopia, so as to provide a basis for precision myopia prevention and control.@*Methods@#From September to October 2020, a stratified cluster sampling method was used in 16 districts of Shanghai. After matching the teaching environment testing classrooms with the classrooms where the students were surveyed, totally 470 classrooms and 14 624 students were monitored. Trained professional technicians used laser range finder, luxmeter to measure parameters about teaching environmental health. Students were subject vision testing and questionnaires. Multilevel models was used to analyze the association between teaching environment and screening myopia.@*Results@#The qualified rates of each indicators of teaching environmental health were as follows: window to floor area ratio (93.0%), classroom area per capita (82.1%), uniformity ratio of illuminance of blackboard ( 79.7% ), blackboard size (68.7%), daylight factor (67.0%), blackboard hanging height (66.9%), average illuminance on desk (66.4%), uniformity ratio of illuminance of desk (63.6%), reflectance of blackboard (46.8%), average illuminance on blackboard (41.4%), reflectance of wall (33.2%), desk and chair allocation compliance rate (19.8%). The results of two level Logistic model analysis showed that unqualified average illuminance on blackboard was positively associated with screening myopia ( OR =1.24, 95% CI = 1.05 -1.47, P <0.05).@*Conclusion@#Teaching environmental health of primary and secondary schools in Shanghai is not optimistic, teaching environment especially the desk and chair allocation compliance rate need to be improved. The average illumination on blackboard is positively correlated with screening myopia, suggesting that myopia prevention and control can focus on improving the illuminance on blackboard.

Process-Aid Solid Engineering Triggers Delicately Modulation of Y-Series Non-Fullerene Acceptor for Efficient Organic Solar Cells.

Volatile solids with symmetric π-backbone are intensively implemented on manipulating the nanomorphology for improving the operability and stability of organic solar cells. However, due to the isotropic stacking, the announced solids with symmetric geometry cannot modify the microscopic phase separation and component distribution collaboratively, which will constrain the promotion of exciton splitting and charge collection efficiency. Inspired by the superiorities of asymmetric configuration, a novel process-aid solid (PAS) engineering is proposed. By coupling with BTP core unit in Y-series molecule, an asymmetric, volatile 1,3-dibromo-5-chlorobenzene solid can induce the anisotropic dipole direction, elevated dipole moment, and interlaminar interaction spontaneously. Due to the synergetic effects on the favorable phase separation and desired component distribution, the PAS-treated devices feature the evident improvement of exciton splitting, charge transport, and collection, accompanied by the suppressed trap-assisted recombination. Consequently, an impressive fill factor of 80.2% with maximum power conversion efficiency (PCE) of 18.5% in the PAS-treated device is achieved. More strikingly, the PAS-treated devices demonstrate a promising thickness-tolerance character, where a record PCE of 17.0% is yielded in PAS devices with a 300 nm thickness photoactive layer, which represents the highest PCE for thick-film organic solar cells.

The blooming intersection of subfatin and metabolic syndrome.

Metabolic Syndrome (MS) remains the leading cause of mortality and morbidity globally. Adipose tissue releases adipokines that play key roles in metabolic and cardio-cerebro-vascular homeostasis. Subfatin, induced after exercise or upon cold exposure in adipose tissue, is a novel secreted protein homologous to Metrn, a neutrophic factor with angiogenic properties. The protein was proved to be of great significance in the browning of white adipose tissue (BWT) and insulin resistance (IR). It affected insulin sensitivity at least via its local autocrine/paracrine action through AMP-activated protein kinase (AMPK) or peroxisome proliferator-activated receptor δ (PPAR-δ) dependent signaling. Subfatin blocked the release of inflammatory mediators, improved intracellular insulin signal transduction and reversed IR. It also improved glucose tolerance and played a key role in metabolism and cardiovascular and cerebrovascular homeostasis. It was reported that the level of serum subfatin was significantly correlated with the occurrence and severity of coronary heart disease, which might be a new target for the treatment of coronary heart disease. In addition, exercise increased the level of subfatin in circulation and adipose tissue, promoted energy consumption, improved glucose and lipid metabolism, increased the heat production of brown fat, and strengthened the anti-inflammatory mechanism. Given its role in metabolic disorders, subfatin is considered as a candidate biomarker of MS. However, the clinical significance of subfatin remains largely unclear. The purpose of this article is to review the research on the effect of subfatin on MS in recent years.

STC2 Is a Potential Prognostic Biomarker for Pancreatic Cancer and Promotes Migration and Invasion by Inducing Epithelial-Mesenchymal Transition.

Aberrant expression of stanniocalcin 2 (STC2) is implicated in cancer development. STC2 acts as a tumor promoter to drive some cancers. However, its contribution to the development of pancreatic cancer remains unclear. This study showed that the expression of STC2 was significantly upregulated in pancreatic cancer tissues. Moreover, its expression was positively correlated with tumor size and lymph node metastasis and negatively correlated with 5-year survival rate of pancreatic cancer patients. Additionally, the expression levels of STC2 were a novel biomarker for predicting overall survival rate after surgery. Furthermore, overexpression of STC2 could promote the proliferation, migration, and invasion of pancreatic cancer cell lines, while knocking down of STC2 led to antiproliferation and antimetastasis activities. Further mechanistic investigations revealed that the expression of STC2 could significantly promote the epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. These data indicated that the overexpression of STC2 in pancreatic cancer contributes to the metastasis through the promotion of EMT, suggesting that STC2 is a potential prognostic biomarker and therapeutic target for pancreatic cancer.

Physical fitness among middle school students in Henan Province and associated factors / 中国学校卫生

Objective@#To understand physical fitness among students aged 13-18 years in Henan Province and its influencing factors.@*Methods@#Data of 21 785 students aged 13-18 years who participated in the national physical fitness surveys in Henan Province in 2014 were analyzed based on phyical fitness indicators and the questionnarie of physical exercise. The qualified rates of physical fitness indicators were evaluated based on the "National Students Constitutional Health Standards"(2014 revised edition).@*Results@#In 2014, the eligible rate for physical test was 85.6% for boys and 82.5% for girls. Higher eligible rate was observed among boys with sleep duration less than 7 hours, compared to those with higher than 7 hours, while lower eligible rate was more likely observed in boys who reported sweaty and tired in PE class(OR=0.76), sweay and extreme tired in PE class(OR=0.72). Higher eligible rate was more common among girls who attended exercise during recess 2-3 times per day (OR=1.18) compared to those attended exercises higher than 3 times per day. Lower eligible rate was more common among girls with sleep duration less than 7 hours (OR=0.88) and those with low attendance in school recess exercises(OR=0.77). Normal weight, living in urban area, sufficient and regular PE class, daily physical exercise for more than 1 hour, enjoying physical exercise and extracurricular sports activities or long-distance running activities have higher success rates(P<0.05).@*Conclusion@#There is a relatively high eligible rate of phyical fitness among middle school boys and girls in Henan Province. Physical fitness is related to multiple factors. These findings highlight the need to target physical fitness interventions with sufficient time allocation in PE class and physical activity so as to effectively promote the phyical quality of students.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the identification of beta-hemolytic streptococci.

OBJECTIVE: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as promising technology for species identification. The purpose of this investigation was to compare the performance of MS and the traditional method for identification of beta-hemolytic streptococci (BHS). METHODS: Clinical BHS isolates were identified by the BD Phoenix SMIC/ID Streptococcal panels, and two MALDI-TOF MS platforms: the VITEK MS and the Bruker MALDI Biotyper systems respectively. In case of discordant results, 16sRNA sequencing was performed to provide the reference ID. RESULTS: A total of 96 isolates of BHS were analyzed. Thirty-six isolates (20.8%) were re-tested by BD Phoenix for identification failure; and four isolates (4.2%) were rerun on the Bruker system for low identification score. No isolate need a second run for identification by Vitek MS system. Overall, BD Phoenix, BioTyper and Vitek MS automated system accurately identified 76 strains (79.2%), 91 (94.7%) strains and 92 (95.8%) strains, respectively. CONCLUSIONS: Our study suggests that MALDI-TOF MS is a superior method to conventional phenotypic methods for BHS identification.

The value of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in identifying clinically relevant bacteria: a comparison with automated microbiology system.

BACKGROUND: Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been developed as a new-type soft ionization mass spectrometry in the recent year. Increasing number of clinical microbiological laboratories consider it as an innovate approach for bacterial identification. METHODS: A total of 876 clinical strains, comprising 52 species in 27 genus, were obtained from Fudan University Affiliated Zhongshan Hospital. We compared the identification accuracy of the Vitek MS system (bioMerieux, Marcy l'Etoile) to other conventional methods for bacterial identification. 16S rRNA gene sequencing was performed as a reference identification method in cases of discrepant results. RESULTS: The Vitek MS system consistently produced accurate results within minutes of loading, while conventional methods required several hours to produce identification results. Among the 876 isolates, the overall performance of Vitek MS was significantly better than the conventional method both for correct species identification (830, 94.7% vs. 746, 85.2%, respectively, P=0.000). CONCLUSIONS: Compared to traditional identification methods, MALDI-TOF MS is a rapid, accurate and economical technique to enhance the clinical value of microorganism identification.

[Analysis of clinical characteristics and risk factors associated with prognosis of patients with candidemia].

OBJECTIVE: To explore the microbiological and clinical characteristics of patients with candidemia and analyze their prognostic risk factors. METHODS: A retrospective analysis was conducted for hospitalized patients with candidemia from January 2008 to December 2012 at Affiliated Zhongshan Hospital, Fudan University. Pathogen spectrum, resistance pattern, underlying diseases, therapy received and patient prognosis were collected by chart review. The univariate and multivariate Logistic regression analyses were used to determine the prognostic risk factors of candidemia. RESULTS: A total of 138 inpatients were identified. There were 98 males and 40 females with a mean age of (61.3 ± 16.6) years. The morbidity rate of candidemia in annual discharged patients was 0.034%-0.051%. The most common pathogens were Candida albicans (n = 72, 52.2%), Candida parapsilosis (n = 29, 21.0%) and Candida tropicalis (n = 16, 11.6%). The antibiotic susceptible rate of azole for Candida was 90.9%-97.4% while 55.6%-83.3% for Candida tropicalis. The overall case fatality rate of candidemia was 39.1% (54/138) while the attributable case fatality rate 31.9% (44/138). Multivariate Logistic regression analysis indicated acute physiology and chronic health evaluation II(APACHE II) score ≥ 20 points (OR = 8.025, 95%CI: 2.032-31.696, P = 0.003), hypoproteinemia (OR = 6.213, 95%CI: 1.849-20.879, P = 0.003), concurrent bacteremia (OR = 5.541, 95%CI: 1.576-19.487, P = 0.008) and indwelling urethral catheter (OR = 13.776, 95%CI: 1.402-135.352, P = 0.024) were the independent risk factors of candidemia-related mortality, while removal or replacement of central venous catheter (OR = 0.231, 59%CI: 0.075-0.716, P = 0.011) and surgery within 30 days (OR = 0.206, 95%CI: 0.050-0.857, P = 0.030) were the protective factors. CONCLUSIONS: Candida albicans is the most common causative agent. The case fatality rate of candidemia has remained high. APACHE II score ≥ 20 points, hypoproteinemia, indwelling urethral catheter and concurrent bacteremia are independent risk factors attributing to candidemia-related mortality while removal or replacement of central venous catheter and surgery within 30 days are the protective ones.

[Activity of macrolides and fluoroquinolones against intracellular Legionella pneumophila].

OBJECTIVE: To evaluate the activity of macrolides and fluoroquinolones against Legionella pneumophila by intracellular susceptibility testing. METHODS: Minimum inhibitory concentration (MIC) was determined by standard agar dilution test according to the CLSI. For intracellular assays, legionella pneumonia was used to infect human monocytic cell line THP-1. Erythromycin, azithromycin, levofloxacin and moxifloxacin at 1 × MIC, 4 × MIC, 8 × MIC were added following phagocytosis. Number of viable bacteria was enumerated at 24 h on BCYE (buffered charcoal yeast extract) agar in duplicates using standard plate count method. The result was expressed as percentage inhibition. Mann-Whitney U test was used to determine the significant differences in mean percentage inhibition between agents. RESULTS: Percentage inhibition at 24 h were as follows: Erythromycin 1 × MIC (50.18 ± 27.29)%, 4 × MIC (79.48 ± 20.08)%, 8 × MIC (91.46 ± 8.70)%; Azithromycin 1 × MIC (66.77 ± 26.18)%, 4 × MIC (91.73 ± 8.72)%, 8 × MIC (97.10 ± 3.37)%; Levofloxacin 1 × MIC (99.84 ± 0.25)%, 4 × MIC (99.99 ± 0.02)%, 8 × MIC (99.99 ± 0.01)%; Moxifloxacin 1 × MIC (99.90 ± 0.10)%, 4 × MIC (99.99 ± 0.03)%, 8 × MIC (99.99 ± 0.03)%. The fluoroquinolones showed greater inhibitory activity than macrolides against legionella pneumophila(u = 1.0, 2.0, 5.0, P < 0.05). Levofloxacin and moxifloxacin had the same intracellular activity against legionella pneumophila (u = 190, 183, 217, P > 0.05). Azithromycin was more effective than erythromycin in inhibiting intracellular legionella pneumophila (u = 132, 125, 128, P < 0.05). CONCLUSIONS: The fluoroquinolones were more active than macrolides against legionella pneumophila. The intracellular activity of levofloxacin against legionella pneumophila appeared to be similar to moxifloxacin. Azithromycin was demonstrated to have superior activity against legionella pneumophila compared with erythromycin.

[The characteristics of CT imaging and diagnosis of pulmonary cryptococcosis in 42 cases with non-acquired immune deficiency syndrome].

OBJECTIVE: To further elucidate the CT characteristics and diagnostic approaches to non-acquired immune deficiency syndrome patients with pulmonary cryptococcosis. METHODS: The histories of forty-two pulmonary cryptococcosis (PC) patients diagnosed in Zhongshan Hospital from 2003-2008 were collected and analyzed for demography data, underlying conditions, clinical symptoms, chest CT and diagnostic studies. RESULTS: None of the 42 PC patients had avian or its feces contacting history, and 71.4% (30/42) of them were immunocompetent. The most frequent CT lesions were multiple nodules (67.9%) with peripheral predominance (67.9%), and cavitations (50%) often presented within them. Masses/consolidation (31.4%) and patching lesions (2.9%) could exist occasionally. Positive detection rates of non-aggressive examinations including sputum, bronchoalveolar lavage fluid and bronchofibroscopy aspiration were 4.3%, 8.3% and 6.3% respectively, while those of aggressive approaches including transbronchial lung biopsy (TBLB), thin needle aspiration biopsy (TNAB) and pneumonectomy by surgery were 64.7%, 64.3% and 100% respectively. Non-aggressive serum cryptococcus antigen test was performed in 14 patients who had been diagnosed by histopathology or pathogen culture, and all of them were positive. CONCLUSION: Our study suggests that PC is common in immunocompetent population. Avian or its feces contacting is not so important as used opinion to PC differential diagnosis. CT characteristics of PC are diversiform and always change very slowly. Besides the most frequent multiple nodules with subpleural predominance, pulmonary lesions can present as masses, consolidation or patching. Aggressive techniques such as TBLB and TNAB are benefit to clinical diagnosis of PC, and non-aggressive serum cryptococcus antigen test may be promising for its early diagnosis as well as clinical course follow-up and therapeutic effect evaluation.