A new alkaloid called Litsine E (1) and three known aporphine alkaloids (2-4) were isolated from Litsea glutinosa. The structure of the new compound was established using spectroscopic techniques ...such as HMBC, HSQC, COSY, NOESY, and HRESIMS. Electronic circular dichroism (ECD) calculations were used to estimate its absolute configuration. Subsequently, the newly identified compound was evaluated for its potential to attenuate palmitate-induced viability, demonstrating a significant increase in viability in MIN6 cells.
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The rapid advance of fused-ring electron acceptors (FREAs) has made them a potential substitute to fullerene-based acceptors and offered new avenues for the construction of organic solar cells ...(OSCs). Nonfused-ring acceptors (NFRAs) could significantly reduce the synthetic cost while achieving reasonable power conversion efficiencies (PCEs). Widely used fullerene acceptors have been applied as a second acceptor to regulate the morphology, absorption, and electron transport. To take full advantage of both nonfullerene and fullerene acceptors at the same time, we rationally designed and synthesized two novel NFRAs with phenyl-C
-butyric acid methyl ester (PCBM) as the lateral pendent. With the incorporation of fullerene pendent in
and
, varied UV-vis absorption and photoluminescence (PL) quenching behaviors were observed, and isotropic diffraction patterns were obtained via grazing incidence wide-angle X-ray scattering (GIWAXS) measurements. The bulky, spherical, and electronic isotropic fullerene pendent could effectively suppress severe molecular aggregation and form the preferred blend morphology. This strategy significantly improved the efficiencies for exciton separation and charge collection relative to the control acceptor
. Finally, the
,
, and fill factor (FF) of
-based devices were simultaneously improved and an enhanced PCE of 13.55% was accomplished.
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IJS, KILJ, NUK, PNG, UL, UM
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494.
PR-Miner Li, Zhenmin; Zhou, Yuanyuan
Foundations of Software Engineering: Proceedings of the 10th European software engineering conference held jointly with 13th ACM SIGSOFT international symposium on Foundations of software engineering; 05-09 Sept. 2005,
09/2005
Conference Proceeding
Programs usually follow many implicit programming rules, most of which are too tedious to be documented by programmers. When these rules are violated by programmers who are unaware of or forget about ...them, defects can be easily introduced. Therefore, it is highly desirable to have tools to automatically extract such rules and also to automatically detect violations. Previous work in this direction focuses on simple function-pair based programming rules and additionally requires programmers to provide rule templates.This paper proposes a general method called PR-Miner that uses a data mining technique called frequent itemset mining to efficiently extract implicit programming rules from large software code written in an industrial programming language such as C, requiring little effort from programmers and no prior knowledge of the software. Benefiting from frequent itemset mining, PR-Miner can extract programming rules in general forms (without being constrained by any fixed rule templates) that can contain multiple program elements of various types such as functions, variables and data types. In addition, we also propose an efficient algorithm to automatically detect violations to the extracted programming rules, which are strong indications of bugs.Our evaluation with large software code, including Linux, PostgreSQL Server and the Apache HTTP Server, with 84K--3M lines of code each, shows that PR-Miner can efficiently extract thousands of general programming rules and detect violations within 2 minutes. Moreover, PR-Miner has detected many violations to the extracted rules. Among the top 60 violations reported by PR-Miner, 16 have been confirmed as bugs in the latest version of Linux, 6 in PostgreSQL and 1 in Apache. Most of them violate complex programming rules that contain more than 2 elements and are thereby difficult for previous tools to detect. We reported these bugs and they are currently being fixed by developers.
Grain boundary is the key interface in polycrystalline halide perovskite semiconductors and devices. In this work, first, we present a fundamental discussion on the role of grain boundaries in ...determining the carrier-transport properties and the (electro)chemical stability of halide perovskites. Then, we demonstrate rational chemical approaches for tailoring grain boundaries in halide perovskite thin films, which will not only lead to the reduction of electronic/ionic defects, but also endow grain-boundaries with new functions. High-performance halide perovskite photovoltaic devices are achieved based on engineered grain boundary interfaces. Furthermore, we provide perspectives on the future research directions on halide perovskite grain boundaries for photovoltaics and beyond.
•This is the first standardized smartphone training program developed.•The program had positive effects on smartphone usage competency and quality of life among the elderly.•The study provides the ...strongest possible evidence of the effectiveness of smartphone training for the elderly.
Given that China has free universities dedicated solely to the elderly, such universities may be the perfect place to provide large numbers of elderly with a systematic program of self-management. Yet, testing health applications in this location has not occurred, partly because time-consuming training is required before applications can be used.
This study aimed to develop and implement a smartphone training program for the elderly and to confirm the effects on smartphone competency and quality of life.
A randomized controlled trial was conducted. Participants were randomly assigned to either the intervention group or the wait-list control group. A smartphone operation manual was provided to all participants. The intervention group received the smartphone training program once a week for 20 weeks. After the study was finished, participants in the wait-list control group were permitted to undergo the smartphone training program.
Of the 344 participants were randomized at the elder university in Huzhou. After 20 weeks of the intervention, the intervention group showed significant improvement in smartphone usage competency (except health applications) and quality of life relative to the wait-list control group (P < 0.05).
This study confirmed the effectiveness of the smartphone training program in the elder university setting. However, further research is needed to strengthen the intervention in the area of health applications.
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Trilayer architectures were designed and investigated to further improve the microwave dielectric properties of the Ba(Mg1/3Nb2/3)O3 (BMN) – Mg4Nb2O9 (MN) system, namely, to achieve temperature ...stability while maintaining high-Q. The calculated phase fractions in randomly distributed (1-x)BMN-xMN ceramics deviated from the designed composition (where the composition with x = 0.045, 0.056, 0.125 and 0.98 was respectively referred to as S1, S2, S3 and MN'), thus allowing it difficult to obtain near-zero τf as expected. In densification studies, doping a little MN was shown to effectively promote the sintering of BMN and provide the possibility for layer-cofired optimization. Fortunately, undesired differences in composition and performance could be suppressed with the weakened ion diffusion occurring at narrow interfaces with a width of ∼2.5 μm in the S1/MN'/S1 trilayer architecture. Considering the influence of cofired compatibility and stress of dielectric layers, the compositionally optimized S3/MN'/S3 ceramics sintered at 1340 °C exhibited excellent microwave dielectric properties of εr = 21.95, Q × f = 110,482 GHz (f0 = 6.870 GHz), and τf = 0.965 ppm/°C. Moreover, the dielectric response mechanism of layered ceramics was clarified by establishing the relationship between the layered architecture, dielectric properties and electric field distribution using the finite element method and high-frequency structure simulator (HFSS). This suggests that layered architectures like S1-3/MN'/S1-3 could effectively compensate for the dielectric properties and hold a promising application prospect of 5G wireless communication.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Hearing loss is a common chronic sensory deficit that has become a major public health concern worldwide. Hearing loss is well documented to be induced by noise and ototoxic drugs, and the ...association of hearing loss with environmental pollutants has received increasing attention. Organochlorine pesticides (OCPs) are an important group of environmental pollutants that exist ubiquitously in the human body and continue to represent a significant environmental health concern. Our case-control study was performed to explore the association between serum levels of OCPs and the risk of hearing loss in China, including 87 case-control pairs. Serum concentrations of 15 OCPs were measured. Pearson's correlation analysis and principal component analysis of frequently detected (>80%) OCPs showed a different distribution pattern, indicating possible exposure sources/scenarios for the case-control adult population. A higher α-hexachlorocyclohexane (α-HCH) level was a risk factor for an increased prevalence of hearing loss. The risk of hearing loss was increased by approximately 5.25-fold in the highest tertile compared with the lowest tertile. Furthermore, a significant association of the α-HCH level with an increased hearing threshold was observed at mid/high frequencies. This study provided the first evidence indicating that exposure to α-HCH might be a potential risk factor for hearing loss.
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•The association between serum OCPs and auditory impairment was evaluated in adults.•Serum α-HCH level was a risk factor of increased prevalence of hearing loss.•Correlation of α-HCH with worse hearing at mid- and high-frequencies.
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Previous retrospective cohort studies have found that, compared with oxygen tension in the uterus and fallopian tubes (2 %-8 %), exposure of pre-implantation embryos to atmospheric oxygen tension ...(AtmO2, 20 %) during assisted reproductive technology(ART) can affect embryo quality, pregnancy outcomes and offspring health. However, current research on the effects and mechanisms of AtmO2 on the development of embryos and offspring is mainly limited to animal experiments. Human embryonic stem cells (hESCs) play a special and irreplaceable role in the study of early human embryonic development. In this study, we used hESCs as a model to elucidate the possible effects and mechanisms of AtmO2 exposure on human embryonic development. We found that exposure to AtmO2 can reduce cell viability, produce oxidative stress, increase DNA damage, initiate DNA repair, activate autophagy, and increase cell apoptosis. We also noticed that approximately 50 % of hESCs survived, adapted and proliferated through high expression of self-renewal and pluripotency regulatory factors, and affected embryoid body differentiation. These data indicate that hESCs experience oxidative stress, accumulation of DNA damage, and activate DNA damage response under the selective pressure of AtmO2.Some hESCs undergo cell death, whereas other hESCs adapt and proliferate through increased expression of self-renewal genes. The current findings provide in vitro evidence that exposure to AtmO2 during the early preimplantation stage negatively affects hESCs.
•hESCs experience oxidative stress, DNA damage accumulation, and activate DNA damage response under the selective pressure of AtmO2.•Some hESCs undergo cell death, while other hESCs adapt and proliferate by increasing the expression of self-renewal genes.•AtmO2 exposure negatively affects hESCs during the pre-implantation stage of ART embryos.
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