不规则零件最小包络矩形的求解研究

通过对不规则零件外轮廓曲线进行离散处理,由离散点构建成多边形,再求解多边形的最小包络矩形,通过该过程将不规则零件转化为规则的矩形件排样,从而可以实现计算机自动排样。     

不正常航班恢复模型的贪婪模拟退火算法研究

为解决不正常航班恢复对航空公司带来的严重影响,研究了不正常航班恢复模型及其优化算法,对现有不正常航班恢复优化模型提出适当改进,重点设计了一种贪婪模拟退火算法。算法融合了GRASP和模拟退火算法的特点,提高了领域解的选择效率并且降低了陷入局部最优解的概率。实例证明这种算法可以处理大规模的不正常航班恢复问题,并且能够达到时间代价与结果质量的均衡。     

非正规就业--大学生弱势群体就业的有效途径

目前．大学生整体的就业形势日趋严峻,而大学生中的弱势群体（如专科生、部分农村出身的大学生、女大学生）的就业形势就显得更加严峻。“非正规就业”也许是大学生弱势群体就业的有效途径。     

浅谈不同需求下营销策略的运用

市场营销是“有效益的满足需求”。然而，从静态上来看，不同的时间、不同的地点、不同的行业，市场的需求状况各不相同；从动态上来看，市场的需求又是每时每刻发生着变化。因此，企业只有从消费的实际需求出发，正确地运用市场营销策略，才能在市场中立于不败之地，否则企业就会面临困境，进而走向倒闭。     

振子的过阻尼与临界阻尼现象的分析

振子由于受到阻尼的作用 ,能量不守恒 .分析了振子在过阻尼和临界阻尼情况下的非周期衰变运动 .     

三种微生物血清抗体水平与冠状动脉病变支数的关系

目的：探讨巨细胞病毒（CMV）、肺炎衣原体（CP）、幽门螺杆菌（HP）感染与冠状动脉病变程度的关系。方法：应用荧光抗体法检测儿2例冠状动脉不同病变程度患者血清巨细胞病毒抗体（CMVIgM）、肺炎衣原体抗体（CPIgG、CPIgM）、幽门螺杆菌抗体（HPIgG、HPIgM）水平，并进行比较。结果：冠状动脉三支病变组CPIgG高于≤二支病变组（x^2=4．197 P=0．04），而两组的CMVIgM、CPIgM、HPIgG及HPIgM无差异（分别P=1．00，P=0．436，P=0．528，P=0，739）；血清HPIgG、CPIgG均阳性与单纯血清HPIgG阳性或单纯血清CPIgG阳性患者比较冠状动脉三支血管病变患者多，（x^2=3．717P=0．043，x^2=6．601P=0．01）。结论：冠状动脉病变程度与CP慢性感染有关；复合慢性感染（HP、CP）对血管病变的程度有影响。     

不规范期刊及其验收工作方法研究

不规范期刊不仅影响图书馆的期刊验收工作效率,而且影响期刊管理的整套流程。文章对不规范期刊的12种表现形式进行了概括,对其验收方法进行了论述,为提高不规范期刊的验收质量提供指导。     

Seroprevalence of SARS-CoV-2 in Croatian solid-organ transplant recipients

IntroductionThe data on the coronavirus disease (COVID-19) in solid-organ transplant recipients (SOTRs) in Croatia is unknown. The aim of this study was to analyze the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Croatian SOTRs.Materials and methodsFrom 7 September to 27 November 2020 (beginning of the second COVID-19 pandemic wave), a cross-sectional screening for COVID-19 was performed in the adult outpatient liver (LTRs; N = 280) and kidney transplant recipients (KTRs; N = 232). Serum samples were initially tested for SARS-CoV-2 IgG antibodies using a commercial enzyme-linked immunosorbent assay (ELISA; Vircell Microbiologists, Granada, Spain). All positive samples were confirmed using a virus neutralization test (VNT). Data on risk exposure and COVID-19 related symptoms were collected using a questionnaire.ResultsThe transplanted cohort’s seroprevalence detected by ELISA and VNT was 20.1% and 3.1%, respectively. Neutralizing (NT) antibodies developed in 15.6% of anti-SARS-CoV-2 ELISA IgG positive SOTRs. The difference in seropositivity rates between LTRs and KTRs was not statistically significant (ELISA 21.1% vs. 19.0%, P = 0.554; VNT 3.6% vs. 2.6%, P = 0.082). Overall VNT positivity rates were higher in patients who reported participation in large community events (5.9% vs. 1.0%; P = 0.027) as well as in patients who reported COVID-19 related symptoms in the past six months. In addition, symptomatic VNT positive patients showed significantly higher (P = 0.031) NT antibody titers (median 128, interquartile range (IQR) = 32-128) compared to asymptomatic patients (median 16, IQR = 16-48).ConclusionsThis study showed that 15.6% of anti-SARS-CoV-2 ELISA positive Croatian SOTRs developed NT antibodies indicating protective immunity. Further studies are needed to determine the dynamic of NT antibodies and COVID-19 immunity duration in immunocompromised populations such as LTRs and KTRs.     

英语不规则动词的演变与英语发展整体趋势的自相似性

本文用混沌学的分形理论分析了英语不规则动词的演变,认为英语不规则动词的演变和英语发展的整体趋势存在自相似性。     

A proof of concept for neutralizing antibody-guided vaccine design against SARS-CoV-2

Mutations and transient conformational movements of the receptor binding domain (RBD) that make neutralizing epitopes momentarily unavailable present immune escape routes for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To mitigate viral escape, we developed a cocktail of neutralizing antibodies (NAbs) targeting epitopes located on different domains of spike (S) protein. Screening of a library of monoclonal antibodies generated from peripheral blood mononuclear cells of COVID-19 convalescent patients yielded potent NAbs, targeting the N-terminal domain (NTD) and RBD domain of S, effective at nM concentrations. Remarkably, a combination of RBD-targeting NAbs and NTD-binding NAbs, FC05, enhanced the neutralization potency in cell-based assays and an animal model. Results of competitive surface plasmon resonance assays and cryo-electron microscopy (cryo-EM) structures of antigen-binding fragments bound to S unveil determinants of immunogenicity. Combinations of immunogens, identified in the NTD and RBD of S, when immunized in rabbits and macaques, elicited potent protective immune responses against SARS-CoV-2. More importantly, two immunizations of this combination of NTD and RBD immunogens provided complete protection in macaques against a SARS-CoV-2 challenge, without observable antibody-dependent enhancement of infection. These results provide a proof of concept for neutralization-based immunogen design targeting SARS-CoV-2 NTD and RBD.