DuPont (China)

The expression pattern of 1,529 yeast genes in response to sulfometuron methyl (SM) was analyzed by DNA microarray technology. SM, a potent herbicide, inhibits acetolactate synthase, a branched-chain amino acid biosynthetic enzyme. Exposure of yeast cells to 0.2 microg/ml SM resulted in 40% growth inhibition, a Gcn4p-mediated induction of genes involved in amino acid and cofactor biosynthesis, and starvation response. The accumulation of intermediates led to the induction of stress response genes and the repression of genes involved in carbohydrate metabolism, nucleotide biosynthesis, and sulfur assimilation. Extended exposure to SM led to a relaxation of the initial response and induction of sugar transporter and ergosterol biosynthetic genes, as well as repression of histone and lipid metabolic genes. Exposure to 5 microg/ml SM resulted in >98% growth inhibition and stimulated a similar initial expression change, but with no relaxation after extended exposure. Instead, more stress response and DNA damage repair genes become induced, suggesting a serious cellular consequence. Other salient features of metabolic regulation, such as the coordinated expression of cofactor biosynthetic genes with amino acid biosynthetic ones, were evident from our data. A potential link between SM sensitivity and ergosterol metabolism was uncovered by expression profiling and confirmed by genetic analysis.

A series of constructs that links the rat muscle creatine kinase promoter to the bacterial chloramphenicol acetyltransferase gene was generated. These constructs were introduced into differentiating mouse C2C12 myogenic cells to localize sequences that are important for up-regulation of the creatine kinase gene during myogenic differentiation. A muscle-specific enhancer element responsible for induction of chloramphenicol acetyltransferase expression during myogenesis was localized to a 159-base-pair region from 1,031 to 1,190 base pairs upstream of the transcription start site. Analysis of transient expression experiments using promoters mutated by deletion indicated the presence of multiple functional domains within this muscle-specific regulatory element. A DNA fragment spanning this region was used in DNase I protection experiments. Nuclear extracts derived from C2 myotubes protected three regions (designated E1, E2, and E3) on this fragment from digestion, which indicated there may be three or more trans-acting factors that interact with the creatine kinase muscle enhancer. Gel retardation assays revealed that factors able to bind specifically to E1, E2, and E3 are present in a wide variety of tissues and cell types. Transient expression assays demonstrated that elements in regions E1 and E3, but not necessarily E2, are required for full enhancer activity.

We report a facile, template-free and nontoxic one-pot solvothermal route for synthesizing submicrometer-sized yolk@shell hierarchical spheres, which possess a permeable shell self-assembled by ultrathin anatase TiO2 nanosheets (NSs) with nearly 90% of exposed {001} facets and mesoporous inner sphere with a high specific surface area. Compared to the {001} faceted TiO2 NSs and standard Degussa P25, the anatase TiO2 yolk@shell hierarchical spheres (TiO2 YSHSs) were obtained with surface area up to 245.1 m2 g−1 and their submicrometer scale simultaneously promoted light scattering in the visible region. A light to electricity conversion efficiency (η) of 6.01% was achieved for the DSSCs with TiO2 YSHSs as its photoanode, under 100 mW cm−2 illumination, indicating 49.9% and 34.8% increases compared to the DSSCs with TiO2 NSs (4.01%) and the standard Degussa P25 (4.46%) as photoanodes, respectively. The enhancement can be mainly attributed to the higher dye loading on TiO2 YSHSs (4.35 × 10−5 mol cm−2) than that of TiO2 NSs (3.14 × 10−5 mol cm−2) and P25 (3.32 × 10−5 mol cm−2); longer lifetime of the injected electrons in TiO2 YSHSs film (65.79 ms) than that of in TiO2 NSs film (57.90 ms); and the good capability of light scattering of TiO2 YSHSs in visible light region, which are confirmed by UV-vis spectrophotometer and electrochemical impedance spectroscopy (EIS). The growth mechanism of the TiO2 YSHSs has also been investigated in detail.

A simple optical model is presented to describe the influence of a planar luminescent down-shifting layer (LDSL) on the external quantum efficiencies of photovoltaic solar cells. By employing various visible light-emitting LDSLs based on CdTe quantum dots or CdSe/CdS core–shell quantum dots and tetrapods, we show enhancement in the quantum efficiencies of thin-film CdTe/CdS solar cells predominantly in the ultraviolet regime, the extent of which depends on the photoluminescence quantum yield (PLQY) of the quantum dots. Similarly, a broad enhancement in the quantum efficiencies of crystalline Si solar cells, from ultraviolet to visible regime, can be expected for an infrared emitting LDSL based on PbS quantum dots. A PLQY of 80% or higher is generally required to achieve a maximum possible short-circuit current increase of 16 and 50% for the CdTe/CdS and crystalline Si solar cells, respectively. As also demonstrated in this work, the model can be conveniently extended to incorporate LDSLs based on organic dyes or upconverting materials.

Human milk provides essential nutrients for infant nutrition. A large proportion of human milk is composed of human milk oligosaccharides (HMOs), which are resistant to digestion by the infant. Instead, HMOs act as a bioactive and prebiotic enriching HMO-utilizing bacteria and cause systematic changes in the host. Several species of Bifidobacterium have been shown to utilize HMOs by conserved, as well as species-specific pathways, but less work has been done to study variation within species or sub-species. B. longum subsp. infantis is a prevalent species in the breast-fed infant gut and the molecular mechanisms of HMO utilization for the type strain B. longum subsp. infantis ATCC 15697 (type strain) have been well characterized. We used growth, transcriptomic, and metabolite analysis to characterize key differences in the utilization of 2'FL, 3FL and DFL (FLs) between B. longum subsp. infantis Bi-26 (Bi-26) and the type strain. Bi-26 grows faster, produces unique metabolites, and has a distinct global gene transcription response to FLs compared to the type strain. Taken together the findings demonstrate major strain specific adaptations in Bi-26 to efficient utilization of FLs.

Even though significant progress has been made in understanding and quantifying the hazards to personnel from electric arcs, additional testing is required to better estimate the incident energy produced by electric arcs on the many different types of electric power distribution systems. Additional arc testing has indicated that placing a three phase arc in a specific cubic box increased the incident energy by a factor of 3 compared to the same arc exposure in open air. Peak noise levels during the three-phase electric arc tests were found to be at levels sufficient to cause traumatic ear damage. Leather work gloves were found to provide protection for hands exceeding that of a Class 2 FR clothing system, but less than that of a Class 1 FR clothing system. Of all the head protective systems evaluated, hoods with 80 mil gold-coated polycarbonate windows were found to be the most protective.

meso-Diaminopimelate dehydrogenase (meso-DAPDH) is an NADP(+)-dependent enzyme which catalyzes the reversible oxidative deamination on the d-configuration of meso-2,6-diaminopimelate to produce l-2-amino-6-oxopimelate. In this study, the gene encoding a meso-diaminopimelate dehydrogenase from Symbiobacterium thermophilum was cloned and expressed in Escherichia coli. In addition to the native substrate meso-2,6-diaminopimelate, the purified enzyme also showed activity toward d-alanine, d-valine, and d-lysine. This enzyme catalyzed the reductive amination of 2-keto acids such as pyruvic acid to generate d-amino acids in up to 99% conversion and 99% enantiomeric excess. Since meso-diaminopimelate dehydrogenases are known to be specific to meso-2,6-diaminopimelate, this is a unique wild-type meso-diaminopimelate dehydrogenase with a more relaxed substrate specificity and potential for d-amino acid synthesis. The enzyme is the most stable meso-diaminopimelate dehydrogenase reported to now. Two amino acid residues (F146 and M152) in the substrate binding sites of S. thermophilum meso-DAPDH different from the sequences of other known meso-DAPDHs were replaced with the conserved amino acids in other meso-DAPDHs, and assay of wild-type and mutant enzyme activities revealed that F146 and M152 are not critical in determining the enzyme's substrate specificity. The high thermostability and relaxed substrate profile of S. thermophilum meso-DAPDH warrant it as an excellent starting enzyme for creating effective d-amino acid dehydrogenases by protein engineering.

Epidemiological studies are inconclusive regarding the association between dietary fiber intake and endometrial cancer risk. Thus, we aimed to conduct a meta-analysis to clarify the association between dietary fiber and endometrial cancer risk. We searched the PubMed and ISI Web databases for relevant studies through March 2018. The association between dietary fiber and endometrial cancer risk was evaluated by conducting a meta-analysis including 3 cohort and 12 case–control studies. A significant negative association was observed between total dietary fiber intake and endometrial cancer risk in 11 case–control studies (odds ratios (OR) 0.76, 95% confidence interval (CI): 0.64–0.89, I2 = 35.2%, p = 0.117), but a marginal positive association was observed in three cohort studies (relative risk (RR) 1.22, 95% CI: 1.00–1.49, I2 = 0.0%, p = 0.995). Particularly, a negative association was observed in North America (OR = 0.70, 95% CI: 0.59–0.83, I2 = 8.9%, p = 0.362). In addition, a positive association was observed in cereal fiber (RR = 1.26, 95% CI: 1.03–1.52, I2 = 0.0%, p = 0.530, 3 cohort studies) and a negative association was observed in vegetable fiber (OR = 0.74, 95% CI: 0.58–0.94, I2 = 0.0%, p = 0.445, 3 case–control studies). In conclusion, negative associations with endometrial cancer risk were observed for higher total dietary fiber intake and higher vegetable fiber intake in the case–control studies. However, results from the cohort studies suggested positive relationships of higher total fiber intake and higher cereal fiber intake with endometrial cancer risk.

The challenge to the PV industry is to find test methods which assess the durability of modules and their components to multiple stresses. The effectiveness of these methods can be assessed by comparison to known degradation modes observed in the field. We have developed sequential test methods which apply an accelerated exposure of a key environmental stress including UV, temperature, humidity, and mechanical stress in a sequential fashion. These stresses are applied sequentially to address the need for using established environmental equipment and methods. This methodology has been effective in predicting backsheet failures in the field and examples will be provided. Efforts to reduce the total test time will also be discussed.

Material durability is a critical factor in designing systems to sustain decades of continuous operation in terrestrial environments. As service lifetime expectations of PV modules continue to grow, it is important that we understand the implications of durability on module performance and safety so that manufacturers can make informed decisions on materials selection. Of particular interest are polymeric components- encapsulants and backsheets-that must withstand decades of exposure to sunlight and other terrestrial forces, often in aggressive climates. While investigations of polymer degradation due to individual stressors-such as irradiance, temperature, humidity, and external forces-have been widely investigated in the literature, the interdependency of these stressors as encountered in the field is not well characterized. To better understand the collective impact of environmental stressors on module durability, DuPont has developed an unprecedented global program for evaluating and assessing degradation of module components and materials in the field. Our database includes over 355 installations that account for nearly 2 GW of power, with module service lives ranging from years to decades. We present here results and analysis of our field survey through 2019, in which correlations between operational lifetime and degradation are established and recurring instances of severe backsheet degradation are highlighted. Our findings illustrate the temporal nature of backsheet degradation and highlight the importance of materials selection in mitigating financial risk.

A very low indium content (35 cation % In) a-IZO film, denoted as IZO35/65 or a-ZIO, was fabricated at room temperature. The effect of aluminum (Al) incorporation in IZO35/65 was studied systematically, and reasonably high electrical conductivity and optical transmittance were obtained. After Al doping to an optimum extent, the conductivity was interestingly increased 3 times higher than that of a-ZIO, and this effect could not be attributed to the formation of Al clusters as a further increase in Al led to a significant drop in conductivity. Nonlinear and U-shape resistivity-temperature relationship was observed for some Al doped samples. In addition, an obvious conductivity increase accompanying by the Al2O3 nano-crystallites formation was observed, which provided new evidence to the insulator-metal transition model reported by Nagarajan et al. [Nature Mater. 7, 391 (2008)] recently.

Strain TCF032-E4 was isolated from a traditional Chinese fermented radish. It shares >99% 16S rRNA sequence identity with L. plantarum, L. pentosus and L. paraplantarum. This strain can ferment ribose, galactose, glucose, fructose, mannose, mannitol, N-acetylglucosamine, amygdalin, arbutin, salicin, cellobiose, maltose, lactose, melibiose, trehalose and gentiobiose. It cannot ferment sucrose, which can be used by L. pentosus, L. paraplantarum, L. fabifermentans, L. xiangfangensis and L. mudanjiangensis, as well as most of the L. plantarum strains (88.7%). TCF032-E4 cannot grow at temperature above 32 °C. This strain shares 78.2-83.6% pheS (phenylalanyl-tRNA synthetase alpha subunit) and 89.5-94.9% rpoA (RNA polymerase alpha subunit) sequence identity with L. plantarum, L. pentosus, L. paraplantarum, L. fabifermentans, L. xiangfangensis and L. mudanjiangensis. These results indicate that TCF032-E4 represents a distinct species. This hypothesis was further confirmed by whole-genome sequencing and comparison with available genomes of related species. The draft genome size of TCF032-E4 is approximately 2.9 Mb, with a DNA G+C content of 43.5 mol%. The average nucleotide identity (ANI) between TCF032-E4 and related species ranges from 79.0 to 81.1%, the highest ANI value being observed with L. plantarum subsp. plantarum ATCC 14917T. A novel species, Lactobacillus herbarum sp. nov., is proposed with TCF032-E4T ( = CCTCC AB2015090T = DSM 100358T) as the type strain.

Poly(trimethylene terephthalate) (PTT) which combines properties of polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), is used in everyday products such as apparel and carpet. DuPont has successfully developed a renewably sourced building block, bio‐based 1,3‐propanediol (PDO), through industrial bio‐technology using glucose as the raw material. This green technology has significantly promoted the commercialization of PTT and its development activities. In DuPont's China R&D center, an industrial polymer technology platform has been established to serve the local China market with PTT manufacturing and application support. This platform explores new industrial applications for and modifications to PTT, such as expansion of the application space into engineering polymers (EP), development of fire retardancy, melt viscosity regulation for PTT fiber spinning and the use of PTT in nanocomposite preparations.

The porous silicon wafer filled with acid or Nafion was developed as a proton conduction membrane for micro fuel cells. The pores in size of 3-6 μm penetrated through the silicon wafer were prepared by anodic etching with back illumination. When the sulfuric solution or the Nafion solution sank the porous silicon substrate, it was assembled into the H2/air feed fuel cell test section at ambient conditions using conventional electrodes. For the porous wafer filled with sulfuric solution of 10% and 20%, the open circuit voltages (OCV) of 0.932 V and 0.971 V were obtained and the maximum power density of 12.75 mW/cm2 was achieved. For the Nafion filled porous silicon wafer, an OCV of 0.892 V and a maximum power density of 1.27 mW/cm2 were achieved.

A resistance-grounded power system has a critical element that is often ignored-the neutral-grounding resistor. A resistance-grounded power system should have itpsilas neutral-grounding resistor continuously monitored. During a single-phase-to-ground fault, current flows from the transformer or generator winding through the faulted-phase conductor to the fault and to ground, returning to the source winding through the ground-return path and the neutral-grounding resistor. When a neutral-grounding resistor fails, the failure mode is usually open circuit leaving the ground-return path open. Current-sensing ground-fault protection, which is the type most commonly employed in a resistance-grounded system, will not operate with an open resistor, and the advantages of resistance grounding are unknowingly lost. Inadvertent operation with an ungrounded system and inoperative ground-fault protection can be avoided by using a continuous neutral-grounding-resistor monitor. This paper reviews the benefits of resistance grounding, compares continuous resistor monitoring with planned-maintenance testing and inspection, and defines the characteristics required of a neutral-grounding-resistor-monitor. Three case studies are presented that show the need for continuous monitoring of the neutral-grounding resistor.

Optical properties of ZnCdO/ZnO single quantum well (SQW) grown on c-sapphire substrate by pulsed laser deposition were investigated. Temperature dependent photoluminescence (PL) measurement was performed from 10 to 300 K to study the carrier localization effect and peak evolution. The LO-phonon replicas up to third order with Huang–Rhys factor of 0.17 were observed. The SQW exhibited very strong PL from the well layer and extremely weak emission from the ZnO barriers, indicating high quality interfaces and highly efficient relaxation.

Polymeric backsheets are an important component affecting the performance and durability of photovoltaic modules. The optical properties of the backsheet should be considered in the design and performance of a photovoltaic module and the stability and durability of optical properties have an impact on power, safety and appearance. Changes in optical properties in fielded modules and accelerated durability testing are compared. IR analysis was conducted on various backsheet materials in accelerated durability testing and compared to outdoor performance to better understand the relevant chemical changes and associated degradation mechanisms. The connection between optical properties and chemical changes is discussed.

Head smut, caused by the fungus Sphacelotheca reiliana (Kühn) Clint, is a devastating threat to maize production. In this study, QTL mapping of head smut resistance was performed using a recombinant inbred line (RIL) population from a cross between a resistant line "QI319" and a susceptible line "Huangzaosi" (HZS) with a genetic map constructed from genotyping-by-sequencing (GBS) data and composed of 1638 bin markers. Two head smut resistance QTL were identified, located on Chromosome 2 (q2.09HR) and Chromosome 5 (q5.03HR), q2.09HR is co-localized with a previously reported QTL for head smut resistance, and the effect of q5.03HR has been validated in backcross populations. It was also observed that pyramiding the resistant alleles of both QTL enhanced the level of resistance to head smut. A genome-wide association study (GWAS) using 277 diverse inbred lines was processed to validate the mapped QTL and to identify additional head smut resistance associations. A total of 58 associated SNPs were detected, which were distributed in 31 independent regions. SNPs with significant association to head smut resistance were detected within the q2.09HR and q5.03HR regions, confirming the linkage mapping results. It was also observed that both additive and epistastic effects determine the genetic architecture of head smut resistance in maize. As shown in this study, the combined strategy of linkage mapping and association analysis is a powerful approach in QTL dissection for disease resistance in maize.

AIMS: To identify the mechanism in which way maltodextrin enhance bile tolerance in Lactobacillus plantarum Lp-115. METHODS AND RESULTS: value of L. plantarum Lp-115 cultured in MRSB broth with maltodextrin was three times higher than the control value. After supplementing the medium with 4·0% maltodextrin, the highest survival rate was observed when the bile concentration is 0.3%. CONCLUSIONS: In summary, maltodextrin exhibited a significant improvement of bile tolerance and it could enhance cell hydrophobicity, shift the fatty acid composition of the membrane and induce the expression of a bile salt hydrolase gene (pva3) significantly. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report concerning the mechanism of maltodextrin enhancing the bile tolerance. This study promotes the application of maltodextrin as a choice to protect probiotic L. plantarum strains against the bile salt stress.

M for R6G. The spot-to-spot SERS signals show that the intensity variation was less than 10%. Besides, the SERS signals can be maintained over 7 weeks. Further investigation was then successfully carried out to detect polycyclic aromatic hydrocarbons (PAHs), which are commonly used as flammable chemicals. In our perception, this wearable fire-retardant screen-printed SERS array sensor would be an ideal candidate for practical on-site environmental emergency monitoring due to its fire-retardant capability and timely measurement on a portable carrier.