Single Crystal Seed Induced Epitaxial Growth Stabilizes α-FAPbI3 in Perovskite Solar Cells.

FAPbI3 stands out as an ideal candidate for the photoabsorbing layer of perovskite solar cells (PSCs), showcasing outstanding photovoltaic properties. Nonetheless, stabilizing photoactive α-FAPbI3 remains a challenge due to the lower formation energy of the competitive photoinactive δ-phase. In this study, we employ tetraethylphosphonium lead tribromide (TEPPbBr3) single crystals as templates for the epitaxial growth of PbI2. The strategic use of TEPPbBr3 optimizes the evolution of intermediates and the crystallization kinetics of perovskites, leading to high-quality and phase-stable α-FAPbI3 films. The TEPPbBr3-modified perovskite exhibits optimized carrier dynamics, yielding a champion efficiency of 25.13% with a small voltage loss of 0.34 V. Furthermore, the target device maintains 90% of its initial PCE under maximum power point (MPP) tracking over 1000 h. This work establishes a promising pathway through single crystal seed based epitaxial growth for achieving satisfactory crystallization regulation and phase stabilization of α-FAPbI3 perovskites toward high-efficiency and stable PSCs.

Highly Efficient and Stable ITO-Free Organic Solar Cells Based on Squaraine N-Doped Quaternary Bulk Heterojunction.

Simultaneously achieving high efficiency and robust device stability remains a significant challenge for organic solar cells (OSCs). Solving this challenge is highly dependent on the film morphology of the bulk heterojunction (BHJ) photoactive blends; however, there is a lack of rational control strategy. Herein, it is shown that the molecular crystallinity and nanomorphology of nonfullerene-based BHJ can be effectively controlled by a squaraine-based doping strategy, leading to an increase in device efficiency from 17.26% to 18.5% when doping 2 wt% squaraine into the PBDB-TF:BTP-eC9:PC71 BM ternary BHJ. The efficiency is further improved to 19.11% (certified 19.06%) using an indium-tin-oxide-free column-patterned microcavity (CPM) architecture. Combined with interfacial modification, CPM quaternary OSC excitingly shows an extrapolated lifetime of ≈23 years based on accelerated aging test, with the mechanism behind enhanced stability well studied. Furthermore, a flexible OSC module with a high and stable efficiency of 15.2% and an overall area of 5 cm2 is successfully fabricated, exhibiting a high average output power for wearable electronics. This work demonstrates that OSCs with new design of BHJ and device architecture are highly promising to be practical relevance with excellent performance and stability.

Concretized structural evolution supported assembly-controlled film-forming kinetics in slot-die coated organic photovoltaics.

Bulk-heterojunction structured small-area organic solar cells are approaching 20% power conversion efficiency, but the blurred film-forming kinetics in the fabrication of large-area devices causes significant PCE loss and restrains the potential of commercialization. Such blurring came from insufficient knowledge of structural evolution during the film-forming process. Here, we concretize the evolution process with structures detailed to the submolecular level by comprehensive investigations of in-situ UV-vis spectroscopy, Atomic Force Microscope, Grazing Incident Wide Angle X-ray Scattering, and molecular dynamic simulation. With such hierarchical structural knowledge, assembly-controlled film-forming kinetics is proposed to explain the whole picture. Such assembly is determined by molecule configuration and can be tuned via external conditions. Understanding this kinetics will contribute to screening large-area device fabrication conditions, and the detailed structural knowledge could inspire the future design of novel photovoltaic materials that are intrinsically excellent in large-area device fabrications.

High anti-Mullerian hormone level is adversely associated with cumulative live birth rates of two embryo transfers after the first initiated cycle in patients with polycystic ovary syndrome.

Objective: Anti-Mullerian hormone (AMH) has been recently identified as a potential predictor of live birth rates (LBRs) following assisted reproductive technology (ART) treatment. This study aimed to investigate the association between AMH levels and the outcomes of in vitro fertilization (IVF) in patients with polycystic ovary syndrome (PCOS). Methods: Patients with PCOS initiating their first ovarian stimulation under the gonadotropin-releasing hormone antagonist protocol at the Guangdong Women and Children Hospital, China, were enrolled from November 2014 to September 2018. A total of 157 patients who underwent fresh embryo transfer (ET) cycles were included in group A, whereas 187 patients who underwent frozen-thawed ET cycles were included in group B. After the failure of the first ET cycle, 94 patients underwent the second ET cycle with frozen-thawed embryos. Of these 94 patients, 52 had failed the first fresh ET cycle (group C) and 42 had failed the first frozen-thawed ET cycle (group D). Successful embryo transfer was defined as live birth. This retrospective cohort study addressed the association between AMH levels and pregnancy outcomes using logistic regression approaches. After adjusting for age, body mass index, antral follicle counts, baseline follicle-stimulating hormone levels and baseline progesterone levels, LBRs were compared among the four groups and the cumulative live birth rate after two embryo transfers (TCLBR) was calculated. Results: The LBRs showed no differences among the four groups. Higher serum AMH levels were found to be associated with a lower TCLBR [adjusted OR 0.937 (0.888-0.987), P = 0.015]. In patients who underwent the second ET cycle, LBRs were inversely proportional to AMH levels [crude OR 0.904 (0.828-0.986), P = 0.022 versus adjusted OR 0.845 (0.754-0.946), P = 0.004, respectively]. In addition, the LBR was approximately 61%-78% lower in the group with AMH levels of >12 ng/mL [crude OR 0.391 (0.168-0.912), P = 0.030 versus adjusted OR 0.217 (0.074-0.635), P = 0.005, respectively]. Conclusions: Among PCOS patients high AMH level (>12 ng/ml) is found to be associated with low TCLBR and low LBR of the second embryo transfer cycles. The results provide limited clinical inferences and warrant further investigation.

Gabapentin for chronic refractory cough: A system review and meta-analysis.

Objective: To evaluate the efficacy and safety of gabapentin in the treatment of chronic refractory cough by Meta-Analysis. Methods: Literatures were retrieved from PubMed, Embase (OvidIP), Cochrane Library, CNKI, VIP, Wanfang Database and China Biomedical Management System and eligible prospective studies were screened. Data were extracted and analyzed by using RevMan 5.4.1 software. Results: Six articles (2 RCTs and 4 prospective studies) with 536 participants were finally included. Meta-analysis showed that gabapentin was better than placebo in cough-specific quality of life (LCQ score, MD = 4.02, 95%CI [3.26,4,78], Z = 10.34, P < 0.00001), cough severity (VAS score, MD = -29.36, 95% CI (-39.46, -19.26), Z = 5.7, P < 0.00001), cough frequency (MD = -29.87, 95% CI [- 43.84, -15.91], Z = 4.19, P < 0.0001) and therapeutic efficacy (RR = 1.37,95%CI [1.13,1.65], Z = 3.27, P = 0.001), and equal in safety (RR = 1.32,95%CI [0.47,3.7], Z = 0.53, P = 0.59). Gabapentin was similar to other neuromodulators in therapeutic efficacy (RR = 1.07,95%CI [0.87,1.32], Z = 0.64, P = 0.52), but its safety was better. Conclusion: Gabapentin is effective in the treatment of chronic refractory cough in both subjective and objective evaluations, and its safety is better than other neuromodulators.

Energy transfer properties of a single-phase Na3Gd(PO4)2:Eu2+,Mn2+ phosphor with excellent thermal stability for w-LEDs.

A high temperature solid state method was used to prepare Na3Gd(PO4)2:Eu2+,Mn2+ phosphors with good thermal stability. The phosphor shows a broadband excitation region of 250-430 nm, which can be matched with the emissions of ultraviolet (UV)/near-ultraviolet (NUV) LED chips for white light emitting diodes (w-LEDs). The energy transfer efficiency is 74.46% from the sensitizer Eu2+ ions to the activator Mn2+ ions, which enhances the intensities of the Na3Gd(PO4)2-based phosphor. In addition, by increasing the Mn2+ doping level in the phosphor, the Na3Gd(PO4)2:Eu2+,Mn2+ phosphor first shows blue light, then turns to white light, and finally emits red light under 365 nm excitation. Besides, the temperature-dependent photoluminescence measurements indicate that the prepared phosphors exhibit good thermal stability. W-LEDs fabricated by combining a 365 nm chip with the Na3Gd(PO4)2:Eu2+,Mn2+ phosphor exhibit bright white light, which has a high color rendering index (CRI) = 91.5, and a relatively low correlated color temperature (CCT) = 5198 K. Moreover, the CIE point is calculated to be at (0.3337, 0.3465), which is located in the white light region. These results indicate that the as-prepared phosphors can be considered as potential candidates for UV/NUV light-excited w-LED applications.

Associations Among Workplace Bullying, Resilience, Insomnia Severity, and Subjective Wellbeing in Chinese Resident Doctors.

BACKGROUND: Although workplace bullying is common among medical workers, its associations with insomnia severity and subjective wellbeing are still unclear. Our study aimed to investigate these associations among resident doctors who are more vulnerable to both workplace bullying and insomnia. METHODS: We conducted a cross-sectional survey of 1,877 resident doctors from 12 hospitals across 7 administrative regions in China. Workplace bullying, resilience, insomnia severity, and subjective wellbeing were evaluated by the Negative Acts Questionnaire-Revised (NAQ-R), the Chinese version of the Connor-Davidson Resilience Scale-10-item (CD-RISC-10), the Insomnia Severity Index, and the Index of Wellbeing, respectively. Further, a logistic regression analysis was used to analyze factors associated with insomnia. In addition, structural equation modeling (SEM) was applied to examine the associations among workplace bullying, resilience, insomnia severity, and subjective wellbeing. RESULTS: In the present study, the rates of workplace bullying and insomnia were 51.4 and 33.2%, respectively. Workplace bullying (OR = 1.056, p < 0.001) and poor resilience (OR = 0.957, p < 0.001) were the factors associated with insomnia after controlling the confounding variables. Further, SEM of the present study revealed a direct relationship between workplace bullying and subjective wellbeing (std-ß = -0.223, p < 0.001). In addition, insomnia severity (std-ß = -0.071, p < 0.001) and resilience (std-ß = -0.092, p < 0.001) can individually or collectively (std-ß = -0.008, p < 0.001) mediate the indirect associations between workplace bullying and subjective wellbeing. However, resilience was found to act as a moderator only in the direct association between workplace bullying and subjective wellbeing. CONCLUSIONS: Workplace bullying and poor resilience were the factors associated with insomnia. Further, greater resilience acted as a buffer in the direct association between workplace bullying and subjective wellbeing, whereas both insomnia severity and resilience were critical mediators in the indirect associations between them.

Aryl-substituted-indanone end-capped nonfullerene acceptors for organic solar cells with a low nonradiative loss.

Three nonfullerene acceptors with different aryl-substituted terminal groups were designed and synthesized. The optimal device obtained a PCE of 11.42%, with a nonradiative energy loss ≤0.16 eV. Non-rigid π-extension of terminal groups is proved to be a feasible strategy to modulate the molecular packing behaviour and reduce nonradiative recombination loss.

Event-based consensus control for multi-agent systems against joint sensor and actuator attacks.

The paper focuses on the observer-based consensus control issue for a class of discrete-time multi-agent systems suffering from the joint actuator and sensor attacks. An event-triggered communication rule with the adaptive threshold update is introduced to reduce the communication burden. A PI-type controller with a finite-time window integral loop is constructed to achieve bounded consensus in the mean-square sense (BCMS). With the help of common properties of Laplace matrices, the closed-loop multi-agent system is converted into an easy-to-analyze pattern. In light of such a pattern, a sufficient condition is derived to realize the desired consensus by the stochastic analysis. Furthermore, the expected gains of the controller and the observer are determined by resorting to matrix inequalities in combination with the cone complementarity linearization algorithm. Finally, a numerical example and a simulation of the platooning vehicle are proposed to illustrate the effectiveness of the proposed control scheme.

Synthesis and Luminescence Properties of a Novel Green-Yellow-Emitting Phosphor BiOCl:Pr3+ for Blue-Light-Based w-LEDs.

The development of white-light-emitting diodes (w-LEDs) makes it meaningful to develop novel high-performance phosphors excited by blue light. Herein, BiOCl:Pr3+ green-yellow phosphors were prepared via a high-temperature solid-state reaction method. The crystal structure, luminescent properties, lifetime, thermal quenching behavior, and quantum yield were studied in detail. The BiOCl:Pr3+ phosphors presented several emission peaks located in green and red regions, under excitation at 453 nm. The CIE coordinates could be tuned along with the changed doping concentration with fair luminescence efficiency. The results also indicated that the optimized doping concentration of Pr3+ ions was at x = 0.0075 because of the concentration quenching behavior resulting from an intense exchange effect. When the temperature reached 150 °C, the intensity of the emission peak at 495 nm could remain at 78% of that at room temperature. The activation energy of 0.20 eV also confirmed that the BiOCl:Pr3+ phosphor exhibited good thermal stability. All these results indicate that the prepared products have potential to be used as a high-performance green-yellow-light-emitting phosphor for blue-light-based w-LEDs.

Investigation of Lactic Acid Bacteria Isolated from Giant Panda Feces for Potential Probiotics In Vitro.

The present study aimed to isolate an optimal lactic acid bacterial strain from the feces of healthy giant pandas. The strain exhibited good stability at low pH and high bile salt concentrations, activity against pathogens relevant to pandas, and antibiotic susceptibility. In the current study, 25 isolates were obtained from de Man, Rogosa, and Sharpe agar. Two (E21 and G83) and eight (E1, E2, E16, E18, E21, E69, E70, and G83) isolates demonstrated good performance at pH 2.0 and bile 2% (w/v), respectively. Three isolates (G83, G88, and G90) possessed better antimicrobial effect on enterotoxigenic Escherichia coli CVCC196 (ETEC) than the rest. One isolate (G83) strongly affected Salmonella, whereas three (G83, G87, and G88) exhibited inhibitory activity against Staphylococcus aureus. All isolates were multi-drug resistant. These isolates were identified as Lactobacillus (5 isolates) and Enterococcus (20 isolates) by 16S rRNA sequencing. Virulence genes were detected in Enterococcus isolates. Isolate G83 was identified as Lactobacillus plantarum and was considered as the best probiotic candidate among all of the experimental isolates. This study provided necessary and important theoretical guidance for further experiments on G83 in vivo.

Efficiency and mechanism of atenolol decomposition in Co-FeOOH catalytic ozonation.

Co-incorporated α-FeOOH nanocrystal (Co-FeOOH) was synthesized and applied for the ozonation of atenolol (ATL) in water. The compound was characterized and recognized as a transitional structure from FeOOH to CoFeO4. The presence of Co-FeOOH was observed to support the formation of •OH by promoting ozone decomposition, and the degradation of ATL and TOC was significantly improved during the catalytic ozonation. Catalytic reactions were rationally designed in different water matrices, efficient and simultaneous removal of ATL and natural organic contaminants was achieved. It was found that the reactions kinetics depend strongly on the solution pH which could alter the surface properties of catalyst and influence the ozone-decomposition. Based on the 19 organic intermediates identified by UPLC/Q-TOF-mass spectrometry, possible reaction pathways were accordingly proposed to elucidate the mechanism of atenolol degradation by ozone molecular and •OH. Three positions of ATL structure were concluded as the most vulnerable sites to be attacked by oxygen species to initiate the degradation path.