国内生态安全研究知识图谱——基于Citespace的计量分析

以CSSCI中2000—2011年299篇生态安全研究论文为研究对象,采用文献共被引网络、关键词共现网络及突现词分析,以信息可视化为手段,对国内生态安全研究现状进行了分析。研究发现,目前国内生态安全研究已完成了基础理论和研究体系的架构,但研究网络过于集中,前沿分支较少。生态安全研究起源、生态安全基础理论、生态风险评价、生态系统评价、土地生态安全研究是国内生态安全研究的主要知识群组。国内生态安全研究主题集聚成3条核心路径:"生态安全基础理论研究"路径、"生态安全-生态系统评价-区域生态安全评价-生态预警"路径、"生态安全-生态风险评价-农村资源生态系统-土地生态安全研究-生态预警"路径。生态预警及土地生态安全研究成为当前生态安全的研究前沿,生态安全研究更趋向于对特色性的生态系统进行分析与评价。     

Production of prone-to-aggregate proteins

Expression of recombinant proteins in Escherichia coli (E. coli) remains the most popular and cost-effective method for producing proteins in basic research and for pharmaceutical applications. Despite accumulating experience and methodologies developed over the years, production of recombinant proteins prone to aggregate in E. coli-based systems poses a major challenge in most research applications. The challenge of manufacturing these proteins for pharmaceutical applications is even greater. This review will discuss effective methods to reduce and even prevent the formation of aggregates in the course of recombinant protein production. We will focus on important steps along the production path, which include cloning, expression, purification, concentration, and storage.     

Land-plant ecology on the basis of functional traits

The tissue traits and architectures of plant species are important for land-plant ecology in two ways. First, they control ecosystem processes and define habitat and resources for other taxa; thus, they are a high priority for understanding the ecosystem at a site. Second, knowledge of trait costs and benefits offers the most promising path to understanding how vegetation properties change along physical geography gradients. There exists an informal shortlist of plant traits that are thought to be most informative. Here, we summarize recent research on correlations and tradeoffs surrounding some traits that are prospects for the shortlist. By extending the list and by developing better models for how traits influence species distributions and interactions, a strong foundation of basic ecology can be established, with many practical applications.     

Ants find the shortest path: a mathematical proof

In the most basic application of Ant Colony Optimization (ACO), a set of artificial ants find the shortest path between a source and a destination. Ants deposit pheromone on paths they take, preferring paths that have more pheromone on them. Since shorter paths are traversed faster, more pheromone accumulates on them in a given time, attracting more ants and leading to reinforcement of the pheromone trail on shorter paths. This is a positive feedback process that can also cause trails to persist on longer paths, even when a shorter path becomes available. To counteract this persistence on a longer path, ACO algorithms employ remedial measures, such as using negative feedback in the form of uniform evaporation on all paths. Obtaining high performance in ACO algorithms typically requires fine tuning several parameters that govern pheromone deposition and removal. This paper proposes a new ACO algorithm, called EigenAnt, for finding the shortest path between a source and a destination, based on selective pheromone removal that occurs only on the path that is actually chosen for each trip. We prove that the shortest path is the only stable equilibrium for EigenAnt, which means that it is maintained for arbitrary initial pheromone concentrations on paths, and even when path lengths change with time. The EigenAnt algorithm uses only two parameters and does not require them to be finely tuned. Simulations that illustrate these properties are provided.     

Importance of basic research in applied phycology

Utilization of algae has extended considerably from the middle of this century, with the consequence of more and more applied research in various directions and fields, the most important of which deals with phycocolloid production and algal cultivation to provide raw material and foodstuff. It is noteworthy that this research can not avoid the use of knowledge obtained by basic research; applied phycology is especially indebted to basic research in adopting biotechnologies which are typically coming from basic research. In counterpart, such a situation is beneficial to basic research. According to the dependence of applied phycology to basic research and the fact that restricted research programs only are nowadays financially supported, the fate of all research seems to be questionable.     

Basic networks: Definition and applications

We define basic networks as the undirected subgraphs with minimal number of units in which the distances (geodesics, minimal path lengths) among a set of selected nodes, which we call seeds, in the original graph are conserved. The additional nodes required to draw the basic network are called connectors. We describe a heuristic strategy to find the basic networks of complex graphs. We also show how the characterization of these networks may help to obtain relevant biological information from highly complex protein-protein interaction data.     

从生态学语言向景观生态规划设计语言的转化途径

本研究旨在探索景观规划设计领域中的生态知识（生态学语言）与生态实践（景观生态规划设计语言）之间的转化关系,希望通过一套逻辑严密、步骤清晰、简单有效的转化途径推进这一学界持续讨论的问题。研究首先通过相关综述研究了二者之间的关系,提出景观生态规划设计三层次研究体系,从而确立了应用基础研究在转化过程中的桥梁地位。然后通过剖析基于岛屿生物地理学原理开展的自然保护区规划的经典方法,发现从生态学基础研究通往生态规划设计应用的桥梁是“空间导则与空间格局”的提炼,基于此提出了T-P-C的转化途径。最后,通过T-P-C途径的指导提出了具有普适性的5步骤转化方法。研究希望通过这5步骤的转化方法,引导更多生态学基础知识能够言之有理、行之有效地转化到具体的景观规划设计实践之中。     

Self-consistent quasineutral dust structures

Distributions of the dusty plasma parameters (electron, ion, and dust densities; dust grain charge; and ion drift velocity) in quasineutral dust structures whose dimensions are much greater than the mean free path of the ions in their interactions with neutral particles are calculated numerically under conditions such that ionization sources are located outside the structures. Planar, cylindrical, and spherical structures are investigated. It is shown that static equilibrium structures are governed by a single (basic) parameter: the electrostatic potential drop between the center of the structure and its boundary. It is found that the maximum value of the basic parameter (in energy units) does not exceed the electron temperature. The basic parameter also determines the total number of dust grains in the structure and the power of external ionization sources that are necessary to sustain this structure. The fact that the basic parameter varies within a limited range allows one to consider all the possible structures with a given dimensionality (planar, cylindrical, and spherical).     

间充质干细胞基础研究与临床转化的中美比较

目的：从基础研究、专利申请、临床试验角度对比分析中美间充质干细胞领域发展现状和趋势,了解中美间充质干细胞领域研究的主要特征,为中国间充质干细胞领域的发展提供建议。方法：检索SCI论文数据、DII专利数据及Clinical Trials临床试验数据及新药审批情况,利用Excel、DDA工具对检索结果进行定量分析和讨论。结果：中国在间充质干细胞基础研究、专利申请及临床试验方面虽起步较晚,但近年来发展迅速,论文、专利和临床试验数量快速增长,2014年起发表论文数量及2016年申请专利数量均超过美国,临床试验注册已达200余项;在骨质疏松、脊髓损伤等研究领域,内分泌系统疾病、自体免疫疾病等临床试验方面形成一定优势,已具备坚实的团队与技术基础。但我国间充质干细胞研究仍面临激烈的竞争,存在进步与发展空间。结论：我国间充质干细胞研究应发挥已有优势,加强战略性布局;重视发展以企业为主导的新药开发路径;做精做细以增强国际竞争力与影响力;加大资金投入和产业政策的支持;健全监管机制及评价体系,抓住机遇的同时积极迎接挑战。     

光片荧光显微镜特点及其应用

传统荧光显微镜由于对某些荧光分子存在光毒性、光损伤等方面的缺陷,无法满足对部分活体样本进行长时间观测的需求。光片荧光显微镜（light sheet fluorescence microscope,LSFM）是一种新型荧光显微镜,有别于激光共聚焦显微镜,其特殊的正交光路设计和高效的信号采集装置,使其具备低光毒性、低光漂白、低光损伤和高时空分辨率等优良特性,从而能对细胞及大尺度生物组织样本进行时空连续性较好的记录,尤其适宜于活体生物样品。基于此,概述了光片荧光显微镜的成像原理、成像优势、成像效果的改进与优化历程及其在生命科学领域应用所取得的研究成果,重点对近三年相关应用进行了汇总,并简要介绍了其在神经生物学、发育生物学、动物细胞生物学和植物科学领域中一部分代表性研究内容,最后,总结了光片荧光显微镜的优点与发展至今仍存在的不足,并对其在光遗传学和多组学研究中的潜在应用进行了展望,以期为研究人员提供较为系统的光片荧光显微镜相关基础知识、最新的研究应用进展以及未来的潜在应用方向,为研究人员提供参考。     

Post-genomic challenges for collaborative research in infectious diseases

Although high-burden pathogens have been prioritized for sequencing, genomic research has yet to yield effective vaccines, diagnostics or therapeutics for the infectious diseases that burden developing countries. International research partnerships are needed more today than ever before, and we propose that increased participation by scientists in endemic areas would overcome current roadblocks and is an essential path towards translational research outcomes.     

Biological surfaces as catalysts of amyloid aggregate nucleation and primary sites of amyloid toxicity

The themes of protein folding, misfolding, aggregation and aggregate toxicity to living systems are among the most exciting frontiers in molecular and cell biology as well as in molecular medicine. This is testified by the increasingly higher number of publications on these issues and the debate in the scientific community about some basic questions still unresolved. One of the latter is the role performed in vitro by synthetic and in vivo by biological surfaces in favouring or disfavouring protein folding and misfolding, in speeding the rate of aggregate nucleation and as key targets of toxic aggregates. Indeed, recent research has highlighted the roles of surfaces in all these phenomena; it has also stressed that early oligomeric assemblies in the path of fibrillization are endowed with the highest cytotoxicity and that the latter most likely follows aggregate interaction with cell membrane(s). The resulting membrane destabilization and permeabilization with early alterations in intracellular redox status and ion homeostasis possibly culminates with cell death. Each of these steps is most likely influenced by the physicochemical and biochemical features of the membrane(s) themselves in ways that are still under investigation. This review summarizes the most recent advances in these fields.     

农业科研试验数据分析系统－LNT

分析了农业科研试验统计的基本方法,简述了统计软件包－ＬＮＴ的程序总控流程及主要功能,阐述了软件包的主要特点,提出了将农业统计分为方差分析、相关通径、回归分析、遗传分析和数据管理五大类２４小类的思想,编写了１２１种统计方法,运行于各种机型的集成软件包－ＬＮＴ。     

中国旅游生态足迹研究可视化分析

旅游生态足迹是一种定量测算旅游可持续发展的方法,对于全面评估旅游者对旅游地的生态环境响应有重要理论意义和现实价值。基于中国知网2004—2017年关于旅游生态足迹的面板数据,运用CiteSpace信息可视化分析软件,绘制国内旅游生态足迹的发文作者、发文机构以及关键词等内容的科学知识图谱,通过梳理该研究领域的发展现状,探讨其未来发展路径和研究方向。研究结果表明:(1)国内旅游生态足迹的发文数量整体呈现出增长趋势,研究作者群体逐渐增多,核心研究团队逐渐突显,但各研究机构的科研能力差距较大;(2)研究涉及学科领域较广,学科交叉性、多样性、综合性等特征明显;(3)旅游生态足迹模型、旅游生态承载力以及旅游可持续发展是该研究领域的核心关键词,区域旅游生态足迹的动态演变过程及其驱动机制、旅游生态系统服务的多功能性和旅游可持续发展路径等方面,将会是未来需要长期关注的研究话题。     

Differential-Evolution Control Parameter Optimization for Unmanned Aerial Vehicle Path Planning

The differential evolution algorithm has been widely applied on unmanned aerial vehicle (UAV) path planning. At present, four random tuning parameters exist for differential evolution algorithm, namely, population size, differential weight, crossover, and generation number. These tuning parameters are required, together with user setting on path and computational cost weightage. However, the optimum settings of these tuning parameters vary according to application. Instead of trial and error, this paper presents an optimization method of differential evolution algorithm for tuning the parameters of UAV path planning. The parameters that this research focuses on are population size, differential weight, crossover, and generation number. The developed algorithm enables the user to simply define the weightage desired between the path and computational cost to converge with the minimum generation required based on user requirement. In conclusion, the proposed optimization of tuning parameters in differential evolution algorithm for UAV path planning expedites and improves the final output path and computational cost.     

HIV international clinical research: exploitation and risk

This paper aims to show that to reduce the level of exploitation present in (some) international clinical trials, research sponsors must aim to provide both an ex-ante expected gain in utility and a fair ex-post distribution of benefits for research subjects. I suggest the following principles of fair risk distribution in international research as the basis of a normative definition of fairness: (a) Persons should not be forced (by circumstance) to gamble in order to achieve or protect basic goods; (b) In cases where one party is gambling with basic goods and the other party is not, the distribution of benefits and burdens must be arranged so that they are of greatest benefit to the worst off; (c) In relationships where one party is gambling for basic goods and the other party is not, the party gambling for basic goods must be assured of some guaranteed benefits in addition to the chance of getting some practical benefits. These principles are applied to the case of HIV international research. I conclude that the research (as described) is mutually advantageous but still exploitative because the distribution of surplus benefits is unfair. It is unfair because research subjects are gambling with and for basic goods but they are not assured of a fair ex-post distribution of benefits. Principles (b) and (c) are not satisfied. Research participants are not accorded enough guaranteed benefits to outweigh the risks they undertake.     

社会经济代谢研究:内涵、发现和展望

社会经济代谢是指由于人类活动导致的物质和能量在社会经济系统内部和边界上的迁移和转换。社会经济代谢研究已经成为产业生态学的核心领域。本文结合典型案例介绍了社会经济代谢研究的内涵和基本步骤,总结了社会经济代谢研究的主要发现:提供了追踪物质在社会经济系统的来源、去向和流动路径的方法与模型;揭示了物质材料及其社会经济代谢过程对现代化生产和生活方式的支撑作用;阐明了人类活动驱动与物质代谢相关的生态环境问题的机制;提供了评估资源利用效率、资源供需趋势和城市矿产开发潜力的模型与基础数据。最后指出了社会经济代谢研究的发展方向:增加研究对象并深化对每种对象的研究精度;拓展或细化研究系统的时空边界;引入并融合新的数据来源和研究方法;将社会经济代谢中的物质流对接到与其相关的生态环境影响;建立可共享、可拓展、可累积的数据平台。     

Pathways of innovation: a history of the first effective treatment for sickle cell anemia

The promise of molecular medicine is the prevention and treatment of illness. Understanding the mechanism of the disease should allow one to "fix" it. For sickle cell anemia, however, knowledge of the biochemical basis of the disease was only partly responsible for finding a means of treating the disease--of equal value were hypotheses and conclusions generated from clinical observations. This article describes the research path that led to the first effective treatment for sickle cell anemia, hydroxy-urea. Rather than exemplifying the "bench-to-bedside" model commonly used to describe the process of therapeutic innovation, this history of this research reveals that the critical advances for the development of treatment came not from basic research, but instead from clinical and patient-oriented research. Given that the linear approach is the prevailing paradigm of therapeutic innovation, this history is important because it indicates the inadequacy of this approach for a relatively straightforward single-gene mutation disease such as sickle cell anemia and suggests the need for multiple models of innovation for more complex diseases. Thus, this article questions the expectations of molecular medicine and the dominance of a linear model of therapeutic innovation, which often excludes or subordinates other models of developing treatments.     

建立以章程为统领的现代医院管理制度初探

建立现代医院管理制度是公立医院改革的核心内容,对医院而言,就是要制定章程并以此为统领,构建科学、高效、系统的管理制度体系。以北京协和医院为例,探讨了建立现代医院管理制度的基本路径、关键环节以及需要把握的基本原则,为我国现代医院管理制度建设提供借鉴和启示。     

A historical overview of chemical research on cannabinoids

The chemical research on the plant cannabinoids and their derivatives over two centuries is concisely reviewed. The tortuous path leading to the discovery of the endogenous cannabinoids is described. Future directions, which will probably be followed are delineated.