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A hazardous gas detector is an important guarantee for detecting hazardous chemical gas leakage sites, and the traditional detector deployment scheme is inefficient. In this paper, we propose a quantitative deployment scheme of gas detectors by considering various factors that affect gas leakage. First, the leakage scene variables, including leakage source variables and environmental variables, are set. Then, a quantitative deployment model of gas detectors is established to avoid the impact of low‐probability, high‐risk scenes. Then, the artificial bee colony algorithm is improved to solve the model. Finally, the deployment scheme is evaluated from the perspective of economic benefits and risks. The original scheme of a certain chemical industry park is compared with the optimized scheme proposed in this paper. The results show that the cumulative risk value of the optimized scheme is much lower. [ABSTRACT FROM AUTHOR]

WCP/steel surface composites were endowed with gradient structure and prepared by powder metallurgy. The mechanical properties, thermal fatigue properties and microstructure of the composites with different W content in the transition layers were analyzed by scanning electron microscopy, metallographic microscope, compression and thermal shock tests, and the influence of W addition on the composites performances was examined. The results show that the composition and structure between the composite layer and the substrate layer are varied by adding tungsten powder in the transition layer, the conflicts in stress, strain, and thermal expansion between the composite layer and the substrate layer are decreased. With the mass fraction of tungsten powder increasing, the W can diffuse both into the substrate layer and the composite layer, which leads to a new phase appearing in the transition layer. The bond between the substrate layer and the composite layer is reinforced. When the W content in the transition layer reaches 30% in mass fraction, the compressive strength reaches 553MPa, and thermal fatigue resistance of WCP/steel surface composite is improved.

Abstract Background Chronic endometritis (CE) is a condition which results in reduced receptivity of embryos by dysregulated lymphocyte subsets, abnormal expression of cytokines, chemokines and other regulatory molecules in the endometrium (EM). Macroautophagy (autophagy), the highly conserved cellular homeostasis pathway, plays an essential role in the development and function of T lymphocytes, and supports T cell lineage stability and survival fitness. The possible relationships between autophagy and local cytokine milieus in repeated implantation failure (RIF) with CE have not been elucidated yet. Methods This case-control study was performed at a large reproductive medicine center between February 2015 and July 2016. Seventy-five recurrent implantation falliure women with CE who had “strawberry aspect” and 75 women with male factor infertility were included. In this study, endometrial expressions of IL-17, IL-10, TGF-β and autophagy related molecules, including LC3-II and mTORC1 were investigated by qRT-PCR, Western blot, immunofluorescence and immunohistochemistry assays. Results The expression of IL-17 was significantly higher in patients with CE compared to women with male factor infertility, while the expressions of IL-10 and TGF-β were significantly lower. Moreover, the expression of autophagy (LC3-II) is increased, while the expression of mTORC1 was impaired. Conclusions CE is associated with shifted cytokine milieu towards Th17 over Treg immunity in endometrium through impaired autophagy by decreased mTORC1.

The lack of ground control points (GCPs) affects the elevation accuracy of digital surface models (DSMs) generated by optical satellite stereo images and limits the application of high-resolution DSMs. It is a feasible idea to use ICESat-2 (Ice, Cloud, and land Elevation Satellite-2) laser altimetry data to improve the elevation accuracy of optical stereo images, but it is necessary to accurately match the two types of data. This paper proposes a DSM registration strategy based on terrain similarity (BOTS), which integrates ICESat-2 laser altimetry data without GCPs and improves the DSM elevation accuracy generation from optical satellite stereo pairs. Under different terrain conditions, Worldview-2, SV-1, GF-7, and ZY-3 stereo pairs were used to verify the effectiveness of this method. The experimental results show that the BOTS method proposed in this paper is more robust when there are a large number of abnormal points in the ICESat-2 data or there is a large elevation gap between DSMs. After fusion of ICESat-2 data, the DSM elevation accuracy extracted from the satellite stereo pair is improved by 73~92%, and the root mean square error (RMSE) of Worldview-2 DSM reaches 0.71 m.

Premise A novel set of microsatellite markers was developed for Juglans sigillata (Juglandaceae), an endemic walnut species in southwestern China, to facilitate cultivar identification and future investigations into the genetic structure and domestication history of this species and its close relatives. Methods and Results We developed 32 microsatellite loci for J. sigillata using genomic data and used them to examine 60 individuals from three natural populations. A high level of polymorphism was detected by these primers, with up to eight alleles observed per locus, and an average of four alleles across populations. The levels of observed and expected heterozygosity ranged from 0.000–1.000 and 0.000–0.785, respectively. All but two of the loci were also successfully amplified in three closely related Eurasian Juglans species (J. regia, J. cathayensis, and J. mandshurica). Conclusions The microsatellite loci identified here provide a powerful resource for examining the genetic structure and domestication history of Juglans, as well as identification of its cultivars.

This paper proposes a new system whose potential function is with three types of asymmetric potential wells, driven by trichotomous noise. Firstly, the three types of asymmetric bistable system are described in detail, and the changes of asymmetric bistable system potential function under different asymmetric factors are analyzed. Secondly, the effect of potential function parameters, asymmetric factor α, noise intensity D, and the probability of particle transition q is discussed, using numerical simulation. The detection effects of traditional symmetric SR and three types of asymmetric SR are observed and compared under the driving of trichotomous noise and periodic signals. The mean of signal-to-noise ratio gain is the indicator of the system's effectiveness on enhancing weak signal. The results indicate that it can make the detection effect of the asymmetric system better than that of the traditional bistable system by adjusting the parameters of the asymmetric stochastic resonance system and trichotomous noise.

Lincomycin is one of the most important antibiotics in clinical practice. To further understand the regulatory mechanism on lincomycin biosynthesis, we investigated a pleiotropic transcriptional regulator AdpAlin in the lincomycin producer Streptomyces lincolnensis NRRL 2936. Deletion of adpAlin (which generated ΔadpAlin) interrupted lincomycin biosynthesis and impaired the morphological differentiation. We also found that putative AdpA binding sites were unusually scattered in the promoters of all the 8 putative operons in the lincomycin biosynthetic gene cluster (BGC). In ΔadpAlin, transcript levels of structural genes in 8 putative operons were decreased with varying degrees, and electrophoretic mobility shift assays (EMSAs) confirmed that AdpAlin activated the overall putative operons via directly binding to their promoter regions. Thus, we speculated that the entire lincomycin biosynthesis is under the control of AdpAlin. Besides, AdpAlin participated in lincomycin biosynthesis by binding to the promoter of lmbU which encoded a cluster sited regulator (CSR) LmbU of lincomycin biosynthesis. Results of qRT-PCR and catechol dioxygenase activity assay showed that AdpAlin activated the transcription of lmbU. In addition, AdpAlin activated the transcription of the bldA by binding to its promoter, suggesting that AdpAlin indirectly participated in lincomycin biosynthesis and morphological differentiation. Uncommon but understandable, AdpAlin auto-activated its own transcription via binding to its own promoter region. In conclusion, we provided a molecular mechanism around the effect of AdpAlin on lincomycin biosynthesis in S. lincolnensis, and revealed a cascade regulation of lincomycin biosynthesis by AdpAlin, LmbU, and BldA.