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Fracture of crystalline silicon (c-Si) solar cells in photovoltaic modules is a big concern to the photovoltaics (PV) industry. Cell cracks cause performance degradation and warranty issues to the manufacturers. The roots of cell fractures lie in the manufacturing and integration process of the cells and modules as they go through a series of elevated temperature and pressure processes, involving bonding of dissimilar materials, causing residual stresses. Evaluation of the exact physical mechanisms leading to these thermomechanical stresses is highly essential to quantify them and optimize the PV modules to address them. We present a novel synchrotron X-ray microdiffraction based techniques to characterize the stress and fracture in the crystalline silicon PV modules. We show the detailed stress state after soldering and lamination process, using the synchrotron X-ray microdiffraction experiments. We also calculate the maximum tolerable microcrack size in the c-Si cells to sustain the residual stress after lamination. We further demonstrate the effect of these residual stresses on the cell fractures using the widely accepted fracture (4-point bending) tests. These test results show that the soldering and lamination induced localized residual stresses indeed reduce the load-carrying capacity of the c-Si cells.
Crystal structure and electronic structure of YMnO3 were investigated by X-ray diffraction and transmission electron microscopy related techniques. According to the density of states (DOS), the individual interband transitions to energy loss peaks in the low energy loss spectrum were assigned. The hybridization of O 2p with Mn 3d and Y 4d analyzed by the partial DOS was critical to the ferroelectric nature of YMnO3. From the simulation of the energy loss near-edge structure, the fine structure of O K-edge was in good agreement with the experimental spectrum. The valence state of Mn (+3) in YMnO3 was determined by a comparison between experiment and calculations.
The value of decolonization as a strategy for preventing methicillin-resistant Staphylococcus aureus (MRSA) in the neonatal intensive care unit (NICU) remains to be determined.
After adding decolonization to further reduce MRSA transmission in our NICU, we conducted this retrospective review to evaluate its effectiveness.
The review included patients who were admitted to our NICU between April 2015 and June 2018 and were eligible for decolonization including twice daily intranasal mupirocin and daily chlorhexidine gluconate bathing over 5 consecutive days. Patients were considered successfully decolonized if 3 subsequent MRSA screenings conducted at 1-week intervals were negative. The MRSA acquisition rate (AR) was calculated as hospital-acquired (HA) MRSA per 1,000 patient days (PD) and was used to measure the effectiveness of the decolonization.
Of the 151 MRSA patients being reviewed, 78 (51.6%) were HA-MRSA, resulting in an overall AR of 1.27 per 1,000 PD. Between April 2015 and February 2016, when only the decolonization was added, the AR was 2.38 per 1,000 PD. Between March 2016 and June 2018 after unit added a technician dedicated to the cleaning of reusable equipment, the AR decreased significantly to 0.92 per 1,000 PD (P < .05). Of the 78 patients who were started on the decolonization, 49 (62.8%) completed the protocol, 11 (14.1%) remained colonized, and 13 (16.7%) were recolonized prior to NICU discharge.
In a NICU with comprehensive MRSA prevention measures in place, enhancing the cleaning of reusable equipment, not decolonization, led to significant reduction of MRSA transmission.
The oriental armyworm, Mythimna separata is an important crop pest in eastern Asia. Nocturnal insects, including nocturnal moths, have phototactic behavior to an artificial light source. Phototactic behavior in insects is species-specific in response to different wavelengths of light sources. Our previous study showed that green (520 nm) light emitting diode (LED) light resulted in a significantly higher phototactic behavior in M. separata moths compared to the other wavelength LED lights. The goal of the present study is to investigate the influence of green light illumination on biological characteristics of different developmental stages in M. separata. Our results revealed that when different developmental stages of M. separata were exposed to the green light illumination in a dark period, several biological characteristics in all developmental stages except for egg stage were positively changed, but those of F1 generation M. separata which are next generation of the adults exposed to the green light did not significantly change compared with the control level. These findings suggest that green light illumination at night (or dark period) has a positive effect on the development and longevity of M. separata.
High-rate lithium ion batteries with long cycling lives can provide electricity grid stabilization services in the presence of large fractions of intermittent generators, such as photovoltaics. Engineering for high rate and long cycle life requires an appropriate selection of materials for both electrode and electrolyte and an understanding of how these materials degrade with use. High-rate lithium ion batteries can also facilitate faster charging of electric vehicles and provide higher energy density alternatives to supercapacitors in mass transport applications.
High-rate lithium ion batteries can play a critical role in decarbonizing our energy systems both through their underpinning of the transition to use renewable energy resources, such as photovoltaics, and electrification of transport. Their ability to be rapidly and frequently charged and discharged can enable this energy storage technology to play a key role in stabilizing future low-carbon electricity networks which integrate large fractions of intermittent renewable energy generators. This decarbonizing transition will require lithium ion technology to provide increased power and longer cycle lives at reduced cost. Rate performance and cycle life are ultimately limited by the materials used and the kinetics associated with the charge transfer reactions and ionic and electronic conduction. We review material strategies for electrode materials and electrolytes that can facilitate high rates and long cycle lives and discuss the important issues of cost, resource availability and recycling.
An experiment was conducted to determine the effects of supplementing different amounts of daidzein in a diet on the growth performance, blood biochemical parameters and meat quality of finishing beef cattle. Thirty finishing Xianan steers were distributed in three groups equilibrated by weight and fed three different dietary treatments (concentrate ratio = 80%): (1) control; (2) 500 mg/kg daidzein and (3) 1000 mg/kg daidzein, respectively. Steers were slaughtered after an 80-day feeding trial. Results showed that daidzein supplementation had no effect on the final body weight, average daily gain and feed conversion rate of steers. Steers fed with 1000 mg/kg daidzein had greater dry matter intake than those fed with control diets. Compared with the control group, the 1000 mg/kg daidzein group had a higher fat thickness, lower shear force and lightness. The pH, drip loss, cooking loss, redness (a*), yellowness (b*), moisture, ash, crude protein and intramuscular fat of the Longissimus dorsi muscle were unaffected by daidzein supplementation. Compared with the control group, the 1000 mg/kg daidzein group significantly increased the serum concentrations of insulin, free fatty acid and Glutamic-pyruvic transaminase. The 500 mg/kg daidzein group significantly increased the serum concentration of tetraiodothyronine compared with the control group. Supplemental daidzein did not affect the blood antioxidant ability and blood immune parameters in serum. In conclusion, daidzein supplementation above 500 mg/day modifies feed intake and metabolic and hormonal profile, with positive and negative effects on meat quality.
Latrophilin (LPH) is known as an adhesion G-protein-coupled receptor which involved in multiple physiological processes in organisms. Previous studies showed that lph not only involved the susceptibility to anticholinesterase insecticides but also affected fecundity in Tribolium castaneum. However, its regulatory mechanisms in these biological processes are still not clear. Here, we identified two potential downstream carboxylesterase (cce) genes of Tclph, esterase4 and esterase6, and further characterized their interactions with Tclph. After treatment of T. castaneum larvae with carbofuran or dichlorvos insecticides, the transcript levels of Tcest4 and Tcest6 were significantly induced from 12 to 72 h. RNAi against Tcest4 or Tcest6 led to the higher mortality compared with the controls after the insecticides treatment, suggesting that these two genes play a vital role in detoxification of insecticides in T. castaneum. Furthermore, with insecticides exposure to Tclph knockdown beetles, the expression of Tcest4 was upregulated but Tcest6 was downregulated, indicating that beetles existed a compensatory response against the insecticides. Additionally, RNAi of Tcest6 resulted in 43% reductions in female egg laying and completely inhibited egg hatching, which showed the similar phenotype as that of Tclph knockdown. These results indicated that Tclph affected fecundity by positively regulating Tcest6 expression. Our findings will provide a new insight into the molecular mechanisms of Tclph involved in physiological functions in T. castaneum.
High dynamic range (HDR) technology is rapidly changing today's video landscape by offering spectacular visual experiences. The development in display technology to support higher luminance levels for commercial and consumer electronic devices such as TVs, smartphones, projectors etc., has created an exponential demand for delivering HDR content to viewers. The essential component of the HDR technology is “expanded contrast,” which allows richer black levels and enhanced brightness, providing dramatic contrast that reveals finer details. The use of “wide color gamut” allows wider color spectrum and richer colors providing aesthetically pleasing true-to-life feel. Such visual enhancements clearly establish HDR as one of the most significant upcoming video technologies.
In this paper, we review major technical advances in this exciting field of study. Quantization of HDR signals is reviewed in the context of transfer functions that convert optical signals to electrical signals and vice versa. They mainly consist of Perceptual Quantization and Hybrid-Log-Gamma approaches. Compression of HDR content is another broad area of study involving several coding approaches, often categorized in terms of backward-compatibility and single/dual layer methods. Some key industry applications of HDR processing systems are also discussed, followed by some future directions of HDR technology.
Hyperbolic polariton modes are highly appealing for a broad range of applications in nanophotonics, including surfaced enhanced sensing, sub-diffractional imaging, and reconfigurable metasurfaces. Here we show that attenuated total reflectance (ATR) micro-spectroscopy using standard spectroscopic tools can launch hyperbolic polaritons in a Kretschmann–Raether configuration. We measure multiple hyperbolic and dielectric modes within the naturally hyperbolic material hexagonal boron nitride as a function of different isotopic enrichments and flake thickness. This overcomes the technical challenges of measurement approaches based on nanostructuring, or scattering scanning near-field optical microscopy. Ultimately, our ATR approach allows us to compare the optical properties of small-scale materials prepared by different techniques systematically.
Most studies underline the contribution of heritable factors for psychiatric disorders. However, heritability estimates depend on the population under study, diagnostic instruments, and study designs that each has its inherent assumptions, strengths, and biases. We aim to test the homogeneity in heritability estimates between two powerful, and state of the art study designs for eight psychiatric disorders.
We assessed heritability based on data of Swedish siblings (N = 4 408 646 full and maternal half-siblings), and based on summary data of eight samples with measured genotypes (N = 125 533 cases and 208 215 controls). All data were based on standard diagnostic criteria. Eight psychiatric disorders were studied: (1) alcohol dependence (AD), (2) anorexia nervosa, (3) attention deficit/hyperactivity disorder (ADHD), (4) autism spectrum disorder, (5) bipolar disorder, (6) major depressive disorder, (7) obsessive-compulsive disorder (OCD), and (8) schizophrenia.
Heritability estimates from sibling data varied from 0.30 for Major Depression to 0.80 for ADHD. The estimates based on the measured genotypes were lower, ranging from 0.10 for AD to 0.28 for OCD, but were significant, and correlated positively (0.19) with national sibling-based estimates. When removing OCD from the data the correlation increased to 0.50.
Given the unique character of each study design, the convergent findings for these eight psychiatric conditions suggest that heritability estimates are robust across different methods. The findings also highlight large differences in genetic and environmental influences between psychiatric disorders, providing future directions for etiological psychiatric research.
Plasma levels of very-long-chain SFA (VLCSFA) are associated with the metabolic syndrome (MetS). However, the associations may vary by different biological activities of individual VLCSFA or population characteristics. We aimed to examine the associations of VLCSFA and MetS risk in Chinese adults. Totally, 2008 Chinese population aged 35–59 years were recruited and followed up from 2010 to 2012. Baseline MetS status and plasma fatty acids data were available for 1729 individuals without serious diseases. Among 899 initially metabolically healthy individuals, we identified 212 incident MetS during the follow-up. Logistic regression analysis was used to estimate OR and 95 % CI. Cross-sectionally, each VLCSFA was inversely associated with MetS risk; comparing with the lowest quartile, the multivariate-adjusted OR for the highest quartile were 0·18 (95 % CI 0·13, 0·25) for C20 : 0, 0·26 (95 % CI 0·18, 0·35) for C22 : 0, 0·19 (95 % CI 0·13, 0·26) for C24 : 0 and 0·16 (0·11, 0·22) for total VLCSFA (all Pfor trend<0·001). The associations remained significant after further adjusting for C16 : 0, C18 : 0, C18 : 3n-3, C22 : 6n-3, n-6 PUFA and MUFA, respectively. Based on follow-up data, C20 : 0 or C22 : 0 was also inversely associated with incident MetS risk. Among the five individual MetS components, higher levels of VLCSFA were most strongly inversely associated with elevated TAG (≥1·7 mmol/l). Plasma levels of VLCSFA were significantly and inversely associated with MetS risk and individual MetS components, especially TAG. Further studies are warranted to confirm the findings and explore underlying mechanisms.
The present study aimed to compare the anti-biofilm activities of four commonly available antiseptic eardrops against biofilms from methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa in vitro.
The anti-biofilm activities of 50 per cent Burow's solution, vinegar with water (1:1), 2 per cent acetic acid solution, and 4 per cent boric acid solution were evaluated using biofilm assays. Additionally, the anti-biofilm activities of the four antiseptic solutions against tympanostomy tube biofilms were compared using a scanning electron microscope.
The inhibition of biofilm formation from methicillin-resistant S aureus and quinolone-resistant P aeruginosa occurred after treatment with 4 per cent boric acid solution, 2 per cent acetic acid solution, and vinegar with water (1:1). However, 50 per cent Burow's solution did not exhibit effective anti-biofilm activity.
The results indicate that 4 per cent boric acid solution and vinegar with water (1:1) are potent inhibitors of biofilms from methicillin-resistant S aureus and quinolone-resistant P aeruginosa, and provide safe pH levels for avoiding ototoxicity.
Northern China has been identified as an independent centre of domestication for various types of millet and other plant species, but tracing the earliest evidence for the exploitation of wild cereals and thus the actual domestication process has proven challenging. Evidence from microscopic analyses of stone tools, including use-wear, starch and phytolith analyses, however, show that in the Shizitan region of north China, various plants have been exploited as far back as 28000 years ago, and wild millets have been harvested and processed by the time of the Last Glacial Maximum, 24000 years ago. This is some 18000–14000 years before the earliest evidence for domesticated millet in this region.