Simulation and optimization of tool-life in manufacturing centers

This paper presents the development of an optimization and a computer-simulation model to evaluate the process plans of a manufacturing center by analyzing the effect of tool failure on system performance. The GPSS/PC simulation program that is used in this study has been built with variables, functions and matrices so that many experiments could be conducted with the model. Sensitivity analysis is presented and the developed model has proven to be useful in determining optimum sequencing of parts for various operating policies.     

II. Yeast sequencing reports. Sequence of a segment of yeast chromosome II shows two novel genes,one almost entirely hydrophobic and the other extremely asparagine-serine rich

A 3·2 kb EcoRI fragment of yeast Saccharomyces cerevisiae was entirely sequenced. Two new open reading frames were identified. The first is extremely hydrophobic, and would likely be an integral membrane protein. It has significant similarity to only one reported gene, a gene of unknown function from Drosophila melanogaster. The second ORF is asparagine-rich and very serine-rich, with a remarkable stretch of nearly 26 consecutive asparagine residues comprised of the same codon. It has no significant similarity to any reported gene. The fragment maps to chromosome II on the left arm between the CDC27 and ILS1 loci. The nucleotide sequence reported in this paper has been deposited in the GenBank database with the Accession Number M89908.     

战役战术导弹目标价值排序的模糊综合评判法

针对现代战争中战役战术导弹运用的特点，确定了战役战术导弹所打击目标价值的评判指标体系，并从分析目标价值的角度出发，用模糊综合评判法对战役战术导弹所打击目标进行价值分析，建立了打击先后顺序的评判模型．最后，用实例证明了，评判模型对战役战术导弹所打击目标进行价值排序的实用性和可行性。     

Minimizing the number of tool switches on a flexible machine

This article analyzes a tool switching problem arising in certain flexible manufacturing environments. A batch of jobs have to be successively processed on a single flexible machine. Each job requires a subset of tools, which have to be placed in the tool magazine of the machine before the job can be processed. The tool magazine has a limited capacity, and, in general, the number of tools needed to produce all the jobs exceeds this capacity. Hence, it is sometimes necessary to change tools between two jobs in a sequence. The problem is then to determine a job sequence and an associated sequence of loadings for the tool magazine, such that the total number of tool switches is minimized. This problem has been previously considered by several authors; it is here revisited, both from a theoretical and from a computational viewpoint. Basic results concerning the computational complexity of the problem are established. Several heuristics are proposed for its solution, and their performance is computationally assessed.     

大凌河流域典型水生植物微生物群落吸附特征试验分析

本文采用高通测序方法对大凌河流域五刺金鱼藻、格菱、狐尾藻、水蓼及芦苇5种水生植物不同季节的微生物群落进行试验分析,分析表明:藻类密度在沉水植物表层要高于浮叶植物表层,微生物群落在浮叶植物根部的结构与其表面存在明显差异。各水生植物的优势生物群落依次为变形菌、梭菌、柔膜菌、鞭脂杆菌、杆菌、疣微菌门,且各微生物群落在季节丰度上存在明显差异性。由此可见,水环境对生物群落的影响要高于植物类型。研究成果可为大凌河流域生态修复工程提供重要理论依据。     

The T Cell Repertoires from Nickel Sensitized Joint Implant Failure Patients

Nickel (Ni²⁺) is one of the most common allergens, affecting around 10–15% of the general population. As the demand for orthopedic implant surgery rises, the number of surgical revisions due to joint implant failure also increases. There is evidence that some patients develop joint failure due to an immune response to a component of the implant, and we have found that Ni²⁺ is an especially important cause. Hence, understanding the mechanisms by which Ni²⁺ allergy induces joint implant failure becomes a critical research question. The structural basis of Ni²⁺ activation of pathogenic T cells is still not clear. The purpose of this study was to characterize Ni²⁺-reactive T cell repertoires derived from the peripheral blood of joint failure patients due to Ni²⁺ sensitization using single-cell sequencing techniques. We stimulated the proliferation of Ni²⁺ -reactive T cells from two implant failure patients in vitro, and sorted them for single-cell VDJ sequencing (10× genomics). We identified 2650 productive V-J spanning pairs. Both TCR α chains and β chains were enriched. TRBV18 usage is the highest in the P7 CD4+ population (18.1%), and TRBV5-1 usage is the highest in the P7 CD8+ population (12.1%). TRBV19 and TRBV20-1 segments are present in a high percentage of both P7 and P9 sequenced T cells. Remarkably, the alpha and beta chain combination of TRAV41-TRBV18 accounts for 13.5% of the CD4+ population of P7 patient. Compared to current Ni specific T cell repertoire studies of contact dermatitis, the Vα and Vβ usages of these joint implant failure patients were different. This could be due to the different availability of self-peptides in these two different tissues. However, TRBV19 (Vβ17) was among frequently used TCR β chains, which are common in previous reports. This implies that some pathogenic T cells could be similar in Ni²⁺ hypersensitivities in skin and joints. The alignment of the TCR CDR3β sequences showed a conserved glutamic acid (Glu) that could potentially interact with Ni²⁺. The study of these Ni²⁺ specific TCRs may shed light on the molecular mechanism of T cell activation by low molecular weight chemical haptens.     

Molecular Mechanisms and Tumor Biological Aspects of 5-Fluorouracil Resistance in HCT116 Human Colorectal Cancer Cells

5-Fluorouracil (5-FU) is a cornerstone drug used in the treatment of colorectal cancer (CRC). However, the development of resistance to 5-FU and its analogs remain an unsolved problem in CRC treatment. In this study, we investigated the molecular mechanisms and tumor biological aspects of 5-FU resistance in CRC HCT116 cells. We established an acquired 5-FU-resistant cell line, HCT116R^F10. HCT116R^F10 cells were cross-resistant to the 5-FU analog, fluorodeoxyuridine. In contrast, HCT116R^F10 cells were collaterally sensitive to SN-38 and CDDP compared with the parental HCT16 cells. Whole-exome sequencing revealed that a cluster of genes associated with the 5-FU metabolic pathway were not significantly mutated in HCT116 or HCT116R^F10 cells. Interestingly, HCT116R^F10 cells were regulated by the function of thymidylate synthase (TS), a 5-FU active metabolite 5-fluorodeoxyuridine monophosphate (FdUMP) inhibiting enzyme. Half of the TS was in an active form, whereas the other half was in an inactive form. This finding indicates that 5-FU-resistant cells exhibited increased TS expression, and the TS enzyme is used to trap FdUMP, resulting in resistance to 5-FU and its analogs.     

SBR法处理柠檬酸废水pH变化规律研究

探索了用SBR法处理柠檬酸废水过程中pH的变化规律。研究了柠檬酸废水处理过程中pH变化与COD处理效率的关系，研究目的在于利用易于检测的水质参数为实现SBR处理过程的自动监测和调控作基础试验研究。     

UASB-SBR工艺处理城市生活污水的研究

研究了UASB工艺处理城市生活污水的可行性，通过UASB与SBR组合工艺的运行实验，得出在水力停留时间3h时，COD去除率为61．67％-82．32％，出水COD达到国家污水排放二级标准。在氮磷去除效果不佳的情况下，采用SBR工艺处理后，其出水COD、SS、氮、磷等指标均达到国家污水一级排放标准。