94 research outputs found

    Generic models for the integrated design of domestic and global supply chain networks with remanufacturing

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    This research focuses on the modeling of strategic supply chain network design. Several comprehensive mixed-integer-programming models are developed for the strategic integrated design of domestic and global supply chain networks with remanufacturing capacity. The models allow simultaneous determination of supplier selection, manufacturing and distribution facility selection and allocation, production quantities, transportation flows, reverse distribution facility selection, and disassembly plant allocation. Additionally, our models incorporate bill of material (BOM) both in the manufacturing process and in disassembly process. Management policies are also considered in the model formulation so that specific management choices, such as multi- sourcing strategy or single sourcing strategy, can be fulfilled in the strategic supply chain network design. Global factors considered in the model include currency exchange rates, transfer prices, allocation of transportation costs, local content requirements, local income taxes, and tariffs. The models are verified by medium-sized numerical examples. Compared to previous literature, the proposed models have two distinctive features. First, the corresponding integrated logistics problem of a global supply chain is formulated with a generalized mathematical form, and thus is not limited to applications for specific industries. Such a methodological measure is rare in previous literature, and has exhibited its potential advantages in addressing complicated global supply chain problems. Second, remanufacturing factors oriented from the enforcement of corresponding governmental regulations for environmental protection are considered in the proposed model. Thus, the corresponding effects may help to determine solution alternatives to improve the performance of a global supply chain with remanufacturing capacit

    Over-expression of glutamine synthetase genes Gln1-3/Gln1-4 improved nitrogen assimilation and maize yields

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    In agriculture, certain fertilizers that contain nitrogen generally tend to provide the most macronutrients for plant growth and development. The cDNAs of Gln1-3 and Gln1-4 genes, encoding glutamine synthetase isoenzymes (GS1), were fused to the rice actin1 promoter and over-expressed in the inbred maize line DH9632 by AgrobacteĀ¬rium-mediated genetic transformation. PCR assays demonstrated the integration of these genes in six transgenic lines. Transcription of Gln1-3 or Gln1-4 in the transformants was also confirmed by semi-quantitative RT-PCR and qRT-PCR; the transgenic lines had significantly higher expression compared with wild type. Transgenic lines L2 and L7 expressed the most Gln1-3 and Gln1-4 mRNA, respectively, and had the most enzyme activity in leaves below the ear after pollination for 14 days. Over-expression of these two genes led to increased chlorophyll conĀ¬tent and improved photosynthesis after 14 days. In addition, yield-related traits such as ear length, ear diameter, ear weight, grain weight per ear, and hundred-kernel weight were improved in the transgenic lines. The plot yield of transgenic L2 was increased by approximately 20%. These results suggest that overexpression of Gln1-3 and Gln1-4 in maize improves yields and enhances nitrogen using efficiency. Thus, transgenic lines overexpressing Gln1-3 or Gln1-4 in maize could potentially be used in maize breeding

    The Role of Type 2 Innate Lymphoid Cells in Allergic Diseases

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    Allergic diseases are significant diseases that affect many patients worldwide. In the past few decades, the incidence of allergic diseases has increased significantly due to environmental changes and social development, which has posed a substantial public health burden and even led to premature death. The understanding of the mechanism underlying allergic diseases has been substantially advanced, and the occurrence of allergic diseases and changes in the immune system state are known to be correlated. With the identification and in-depth understanding of innate lymphoid cells, researchers have gradually revealed that type 2 innate lymphoid cells (ILC2s) play important roles in many allergic diseases. However, our current studies of ILC2s are limited, and their status in allergic diseases remains unclear. This article provides an overview of the common phenotypes and activation pathways of ILC2s in different allergic diseases as well as potential research directions to improve the understanding of their roles in different allergic diseases and ultimately find new treatments for these diseases

    Thermodynamic Simulation of the RDX-Aluminum Interface Using ReaxFF Molecular Dynamics

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    We use reactive molecular dynamics (RMD) simulations to study the interface between cyclotrimethylene trinitramine (RDX) and aluminum (Al) with different oxide layers to elucidate the effect of nanosized Al on thermal decomposition of RDX. A published ReaxFF force field for C/H/N/O elements was retrained to incorporate Al interactions and then used in RMD simulations to characterize compound energetic materials. We find that the predicted adsorption energies for RDX on the Al(111) surface and the apparent activation energies of RDX and RDX/Al are in agreement with ab initio calculations. The Al(111) surface-assisted decomposition of RDX occurs spontaneously without potential barriers, but the decomposition rate becomes slow when compared with that for RDX powder. We also find that the Al(111) surface with an oxide layer (Al oxide) slightly increases the potential barriers for decomposition of RDX molecules, while Ī±-Al_2O_3(0001) retards thermal decomposition of RDX, due to the changes in thermal decomposition kinetics. The most likely mechanism for the thermal decomposition of RDX powder is described by the Avramiā€“Erofeev equation, with n = 3/4, as random nucleation and subsequent growth model. Although the decomposition mechanism of RDX molecules in the RDX/Al matrix complies with three-dimensional diffusion, Janderā€™s equation for RDX(210)/Al oxide and the Zhuralevā€“Lesokinā€“Tempelman (Z-L-T) equation for RDX(210)/Al_2O_3(0001) provide a more accurate description. We conclude that the origin of these differences in dynamic behavior is due to the variations in the oxide layer morphologies

    Identification of pyroptosis-related subtypes and establishment of prognostic model and immune characteristics in asthma

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    BackgroundAlthough studies have shown that cell pyroptosis is involved in the progression of asthma, a systematic analysis of the clinical significance of pyroptosis-related genes (PRGs) cooperating with immune cells in asthma patients is still lacking.MethodsTranscriptome sequencing datasets from patients with different disease courses were used to screen pyroptosis-related differentially expressed genes and perform biological function analysis. Clustering based on K-means unsupervised clustering method is performed to identify pyroptosis-related subtypes in asthma and explore biological functional characteristics of poorly controlled subtypes. Diagnostic markers between subtypes were screened and validated using an asthma mouse model. The infiltration of immune cells in airway epithelium was evaluated based on CIBERSORT, and the correlation between diagnostic markers and immune cells was analyzed. Finally, a risk prediction model was established and experimentally verified using differentially expressed genes between pyroptosis subtypes in combination with asthma control. The cMAP database and molecular docking were utilized to predict potential therapeutic drugs.ResultsNineteen differentially expressed PRGs and two subtypes were identified between patients with mild-to-moderate and severe asthma conditions. Significant differences were observed in asthma control and FEV1 reversibility between the two subtypes. Poor control subtypes were closely related to glucocorticoid resistance and airway remodeling. BNIP3 was identified as a diagnostic marker and associated with immune cell infiltration such as, M2 macrophages. The risk prediction model containing four genes has accurate classification efficiency and prediction value. Small molecules obtained from the cMAP database that may have therapeutic effects on asthma are mainly DPP4 inhibitors.ConclusionPyroptosis and its mediated immune phenotype are crucial in the occurrence, development, and prognosis of asthma. The predictive models and drugs developed on the basis of PRGs may provide new solutions for the management of asthma

    Structural variation and introgression from wild populations in East Asian cattle genomes confer adaptation to local environment

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    BACKGROUND: Structural variations (SVs) in individual genomes are major determinants of complex traits, including adaptability to environmental variables. The Mongolian and Hainan cattle breeds in East Asia are of taurine and indicine origins that have evolved to adapt to cold and hot environments, respectively. However, few studies have investigated SVs in East Asian cattle genomes and their roles in environmental adaptation, and little is known about adaptively introgressed SVs in East Asian cattle. RESULTS: In this study, we examine the roles of SVs in the climate adaptation of these two cattle lineages by generating highly contiguous chromosome-scale genome assemblies. Comparison of the two assemblies along with 18 Mongolian and Hainan cattle genomes obtained by long-read sequencing data provides a catalog of 123,898 nonredundant SVs. Several SVs detected from long reads are in exons of genes associated with epidermal differentiation, skin barrier, and bovine tuberculosis resistance. Functional investigations show that a 108-bp exonic insertion in SPN may affect the uptake of Mycobacterium tuberculosis by macrophages, which might contribute to the low susceptibility of Hainan cattle to bovine tuberculosis. Genotyping of 373 whole genomes from 39 breeds identifies 2610 SVs that are differentiated along a "north-south" gradient in China and overlap with 862 related genes that are enriched in pathways related to environmental adaptation. We identify 1457 Chinese indicine-stratified SVs that possibly originate from banteng and are frequent in Chinese indicine cattle. CONCLUSIONS: Our findings highlight the unique contribution of SVs in East Asian cattle to environmental adaptation and disease resistance

    ANALGESIC EFFECT OF TRANSCRANIAL DIRECT CURRENT STIMULATION ON CHRONIC PAIN IN A RAT MODEL OF OSTEOARTHRITIS AND ITS MECHANISM

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    Objective To investigate the analgesic effect of transcranial direct current stimulation (tDCS) on chronic pain in a rat model of monosodium iodoacetate (MIA)-induced osteoarthritis (OA) and its mechanism. Methods Healthy male Sprague-Dawley rats were randomly divided into sham-operation group, MIA group, tDCS group, and sham-tDCS group, with 9 rats in each group. The rats in the sham-operation group were given intra-articular injection of normal saline into the left knee joint, and those in the MIA group, the tDCS group, and the sham-tDCS group were given MIA injection at the same site to establish a model of chronic pain in OA. On day 21 after MIA injection, the rats in the tDCS group and the sham-tDCS group were treated with real or sham tDCS, respectively, for 8 d. The pain behavioral test was performed for the rats in each group on day 1, 2, and 7 after treatment; the periaqueductal gray (PAG) of rats were collected on day 2 after treatment and Western blot was used to measure the expression of brain-derived neurotrophic factor (BDNF). Results The pain behavioral test showed that compared with the sham-tDCS group, the tDCS group had a significantly longer thermal paw withdrawal latency at each time point after treatment (F=11.25-21.48,P<0.01) and a significantly higher mechanical paw withdrawal threshold at each time point after treatment (F=54.42-186.40,P<0.01). Western blot showed that compared with the sham-tDCS group, the tDCS group had a significant reduction in the protein expression of BDNF in PAG tissue (F=24.70,P<0.01). Conclusion This study shows that tDCS can effectively alleviate chronic pain in rats with MIA-induced OA, and such therapeutic effect can last till day 7 after treatment; tDCS exerts an analgesic effect possibly by downregulating the expression of BDNF and reducing neuronal excitability in PAG tissue of rats with MIA-induced OA

    A new fault tolerant control scheme for nonā€linear systems by Tā€S fuzzy model approach

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    Abstract This paper is concerned with the problem of fault tolerant control for nonā€linear systems with sensor faults based on the Tā€S fuzzy model approach. First, a fault estimation (FE) observer with Lāˆž technique is designed to estimate the fault. Second, by using the fault estimation information, which are provided by the fault estimation observer, a novel fault tolerant control scheme with a fault compensation mechanism in the premise part of the fuzzy controller is presented to compensate the effect of the fault and stabilize the system. Different from the existing methods, where the fault compensation mechanism is only established in the consequent part of the controller, in the presented method, the fault compensation mechanism is established in the consequent part as well as the premise part of the fuzzy controller. Then, by using the fault compensation mechanism, the bound of the deviation between the normalized membership functions of the fuzzy model and those of the controller can be reduced such that the fault tolerant control design can be relaxed. In the end, an example is given to illustrate the validity of the developed fault tolerant controlĀ scheme

    A goal-driven Self-adaptive Software System Design Framework based on Agent

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    AbstractThe methods currently apply to ensure the robustness and dependability of software system do not effectively map to more open, dynamic environments. A new goal-driven self-adaptive software system design framework based on agent is proposed. Every layer of our model provides specific conceptual descriptions and domain capabilities of their domain. let goal be the core modeling concept, a self-adaptive software system modeling framework driven by goal is proposed; let Agent be core implementing entity, the self-adaptive software system is build in open environment
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