具势能衰减的非线性拟抛物方程整体解的不存在性

利用Laplace算子的特征函数法研究了一类具势能衰减的非线性拟抛物方程的初边值问题整体解的不存在性与有限时间爆破．     

Banach空间二阶非线性微分—积分方程两点边值问题整体解的存在性

利用一个新的比较结果和Moench不动点定理，研究了Banach空间二阶非线性微分－积分方程两点边值问题整体解的存在性。     

Banach空间二阶非线性微分-积分方程两点边值问题整体解的存在性

利用一个新的比较结果和Ｍｏｎｃｈ不动点定理,研究了Ｂａｎａｃｈ空间二阶非线性微分－积分方程两点边值问题整体解的存在性     

植物甲基化类黄酮及其O-甲基转移酶研究进展

植物类黄酮是重要的药用成分,其生物学功能与化学结构密切相关.O-甲基化修饰可提高类黄酮的稳定性、蛋白亲和力和生物利用度,从而增强其药用活性.O-甲基转移酶(O-methyltransferase)催化类黄酮合成O-甲基化衍生物,是类黄酮代谢途径中的关键修饰酶.本文综述了植物O-甲基化类黄酮的化学结构、药用功能及其药用价...     

一类广义细菌模型的定解问题

本文讨论一个描述病菌传染的反应一扩散方程组,考虑它的初边值问题．我们用Galerkin方法证明了整体解的存在性和唯一性．     

二阶Volterra型积分微分差分方程非线性边值问题的存在性与唯一性

本文利用微分不等式技巧研究了某一类Volterra型二阶积分微分差分方程非线性边值问题,在上下解存在的条件下,得到了解的存在性和唯一性定理.结果表明:这种技巧为其它边值问题的研究提出了崭新的思路.     

具潜伏期的无免疫型传染病动力学模型解的适定性

考虑一类无免疫型传染病动力学的一阶双曲型方程组的非线性非局部的初边值问题,给出经典解的整体存在唯一性,并同时得到解关于初值条件的连续依赖性.     

糖基化对Notch信号传递系统的影响

Notch信号分子是多细胞生物发育过程中高度保守的一类十分重要的跨膜信 号受体糖蛋白家族.这一信号途径通过局部细胞间的相互作用而产生对多种不成熟细胞分化 的抑制信号, 精确调控细胞的分化潜能,在细胞发育、增殖、分化中起关键作用,参与造血 、T细胞发育、血管生成等重要生理过程.Notch受体分子上具有多种寡糖链,包括N-聚糖、O-岩藻糖聚糖、O-葡萄糖聚糖等,这些寡糖以及相关糖基转移酶对Notch受体-配体结合以及Notch信号传递功能有重要影响.本文就近年来有关Notch受体糖基化及其对Notch信号传递过程的研究进行综述.     

结核分枝杆菌中O-甘露糖基化蛋白功能的研究进展

蛋白质的O-甘露糖基化修饰不仅在真菌和哺乳类细胞中广泛存在,在原核生物中例如分枝杆菌属、棒状杆菌属和链霉菌属中也存在,尤其在引起人类疾病的结核分枝杆菌中研究最多。许多O-甘露糖基化蛋白在结核分枝杆菌毒力以及与宿主相互作用过程中发挥了重要作用。本文就结核分枝杆菌中O-甘露糖基化蛋白生物学功能的进展加以综述。     

表皮生长因子样重复序列糖基化对Notch信号通路的作用

Notch受体是一类存在于多细胞生物中进化上高度保守的跨膜蛋白受体,其介导的信号通路在组织器官的生长发育中起重要作用。糖基化修饰是一类重要的影响多信号通路的蛋白翻译后修饰。Notch受体胞外域的表皮生长因子样重复序列（EGF-R）存在多种糖基化修饰如O-葡聚糖、O-岩藻糖聚糖、O- N-乙酰氨基葡萄糖,这些糖基化修饰可以促进或抑制Notch信号通路。本文主要阐述表皮生长因子样重复序列（EGF-R）的主要糖基化以及对Notch信号通路的影响和其异常导致相关的疾病。     

One pathway, many products

Biosynthetic pathways for secondary metabolites usually make many products, not just one. In this Commentary, we consider why molecular promiscuity might be an evolutionarily advantageous feature of these pathways.     

同一个世界 同一个健康

随着工业化和城镇化水平的持续提高,人类的生活方式发生了翻天覆地的变化,在传统因素依然制约人类健康的同时,食源性疾病与营养结构不合理、畜禽养殖方式转变与宠物快速发展带来人与动物关系深刻变化、生态环境与居住环境变化等非传统因素,对人类健康的制约凸显。面对这些人类健康的新挑战,我们必须因应时代变化,在大力发展医疗卫生事业的同时,树立营养健康、动物健康、环境健康三位一体的现代健康新理念。努力提高营养健康水平,以宠物健康为新的关注点高度重视动物健康,以人居、社区环境为重点营造健康生态环境,建立起现代健康新模式。     

一个带有ATL过程的HTL V-I感染的时滞模型

本文提出并分析了两个关于人体T-细胞淋巴回归Ⅰ型病毒（HTL V-I）感染并带有坏死白血病细胞（ATL）进程的数学模型,一个常微分方程模型,一个离散时滞模型.首先对常微分方程模型进行了分析,运用相应的特征方程得到一个阈值Ro（CD4⁺ T-细胞的基本再生数）.当R₀≤1时,仅有未染病平衡态存在,并且给出了其稳定性;当R₀>1时,有一个染病稳定态存在,并且此时它是稳定的.然后,我们在常微分方程模型中引入了一个离散时滞,通过对时滞模型的超越特征方程的分析,导出了与常微分方程模型中同样的稳定性条件,即时滞模型平衡态的稳定性与时滞的具体值无关.     

Questioning Identity: The Case of One Second-Language Learner

With the goal of illuminating how identity and cognition are in tension in classroom activity, we examine how one second-language learner answers questions in a mainstream second-grade classroom. To understand this learner's participation, we analyze two conflicting "language games." We find the second-language learner often is adept at "passing" as knowing, but that he achieves this identity-preserving expertise at the expense of an understanding of classroom lessons.     

一阶具分布的中立型方程非振动解的判别方法

本文在B-F空间建立的不动点定理的基础上，给出了一阶具分布的中立型方程非振动解存在性的一个判别方法。     

One Bacterial Cell,One Complete Genome

While the bulk of the finished microbial genomes sequenced to date are derived from cultured bacterial and archaeal representatives, the vast majority of microorganisms elude current culturing attempts, severely limiting the ability to recover complete or even partial genomes from these environmental species. Single cell genomics is a novel culture-independent approach, which enables access to the genetic material of an individual cell. No single cell genome has to our knowledge been closed and finished to date. Here we report the completed genome from an uncultured single cell of Candidatus Sulcia muelleri DMIN. Digital PCR on single symbiont cells isolated from the bacteriome of the green sharpshooter Draeculacephala minerva bacteriome allowed us to assess that this bacteria is polyploid with genome copies ranging from approximately 200–900 per cell, making it a most suitable target for single cell finishing efforts. For single cell shotgun sequencing, an individual Sulcia cell was isolated and whole genome amplified by multiple displacement amplification (MDA). Sanger-based finishing methods allowed us to close the genome. To verify the correctness of our single cell genome and exclude MDA-derived artifacts, we independently shotgun sequenced and assembled the Sulcia genome from pooled bacteriomes using a metagenomic approach, yielding a nearly identical genome. Four variations we detected appear to be genuine biological differences between the two samples. Comparison of the single cell genome with bacteriome metagenomic sequence data detected two single nucleotide polymorphisms (SNPs), indicating extremely low genetic diversity within a Sulcia population. This study demonstrates the power of single cell genomics to generate a complete, high quality, non-composite reference genome within an environmental sample, which can be used for population genetic analyzes.     

The theory of feature systems: One feature versus two for Kayardild tense-aspect-mood

Features are central to all major theories of syntax and morphology. Yet it can be a non-trivial task to determine the inventory of features and their values for a given language, and in particular to determine whether to postulate one feature or two in the same semantico-syntactic domain. We illustrate this from tense-aspect-mood (TAM) in Kayardild, and adduce principles for deciding in general between one-feature and two-feature analyses, thereby contributing to the theory of feature systems and their typology.Kayardild shows striking inflectional complexities, investigated in two major studies (Evans 1995a; Round 2013), and it proves particularly revealing for our topic. Both Evans and Round claimed that clauses in Kayardild have not one but two concurrent TAM features. While it is perfectly possible for a language to have two features of the same type, it is unusual. Accordingly, we establish general arguments which would justify postulating two features rather than one; we then apply these specifically to Kayardild TAM. Our finding is at variance with both Evans and Round; on all counts, the evidence which would motivate an analysis in terms of one TAM feature or two is either approximately balanced, or clearly favours an analysis with just one.Thus even when faced with highly complex language facts, we can apply a principled approach to the question of whether we are dealing with one feature or two, and this is encouraging for the many of us seeking a rigorous science of typology. We also find that Kayardild, which in many ways is excitingly exotic, is in this one corner of its grammar quite ordinary.     

One renegade cancer stem cell?

The CSC compartment represents the subpopulation of tumor cells with clonogenic potential and the ability to initiate new tumors. Besides self renewal, one of their main features is their ability to differentiate into variety of cells within the tumor. The question remains whether this potential resides within the single CSC or whether many different CSCs are necessary to generate a heterogeneous population of tumor cells. There is an increasing amount of evidence showing that single CSC indeed has the potential to reconstitute complete tumor phenotype. This is likely to be a general phenomenon and it has been demonstrated in many tumors so far. Here we show that single GBM CSCs have multilineage potential, although not exclusively. Furthermore, our results show that CSCs originating from same tumor are not necessarily uniform in respect to their differentiation potential.     

抗生素耐药防控的One Health策略

抗生素耐药作为威胁公共卫生的巨大挑战已经制约了世界经济发展。我国抗生素使用量大,是世界上抗生素滥用最严重的国家之一。文中对人群、食用动物、环境中抗生素耐药产生的原因以及抗生素耐药现状进行综述,针对我国目前抗生素使用与耐药情况,从One Health理念提出了促进抗生素的科学使用、积极探索新型抗生素研发、建立抗生素立体监测网络系统、推广抗生素耐药教育、预防感染等措施,呼吁建立跨学科、跨部门、跨地域的交流与合作,推进我国抗生素耐药防控工作进一步开展,加强环境保护,维护人类与动物的共同健康。