河西走廊山地-绿洲-荒漠复合系统耦合的景观生态学机制

系统耦合的基础为非生物环境的空间异质性,基本条件为具有类型相同并且相互连通的廓道,系统耦合的景观生态学机制为非生物环境的空间分异和各种干扰导致的景观异质化,各种干扰是系统耦合的介质,系统耦合从本质上可以被看作尺度变大过程中景观组分的融合与性质转换的过程,系统耦合根据干扰的性质可以分为自然耦合和人为耦合2类,自然耦合是人为耦合的基础,系统生态生产力的提高取决于人为耦合的优化过程。     

“山地-绿洲-荒漠”复合系统土地利用变化的生态系统服务权衡与协同效应——以张掖市为例

开展复合生态系统土地利用变化的生态服务效应研究可为优化国土空间格局和强化生态系统管理提供重要的基础依据。以干旱区"山地-绿洲-荒漠"复合系统的典型区域张掖市为例,基于1987年、2000年和2018年3期土地利用数据,以乡级行政区为基本单元,引入相对优势度指数划分山地、绿洲、荒漠子系统,研究复合系统的土地利用变化特征及生态系统服务权衡/协同效应。结果表明：（1）张掖市复合系统呈现地域分异特征,由南部山地系统,中部绿洲系统和北部荒漠系统构成;山地系统以林地和草地为主,绿洲系统以耕地和建设用地为主,荒漠系统以未利用地为主。（2）从时间上看,2000-2018年各系统的土地利用变化更强烈,其中,绿洲系统的耕地面积增加量最大,为363.08km²,荒漠系统的建设用地面积增加幅度最大,为78.23%。各系统土地利用转移模式为：山地系统以草地转耕地为主,绿洲系统和荒漠系统以未利用地转耕地为主。（3）张掖市复合系统的生态服务价值呈增加趋势,其中,荒漠系统生态服务价值量的增幅最大,各子系统的价值量之间的关系表现为山地系统 > 绿洲系统 > 荒漠系统,耕地对各系统生态服务价值贡献量最大。（4）张掖市土地利用变化的协同效应大于权衡效应,其中荒漠系统的生态服务之间均为协同关系,山地系统中供给服务与其他服务呈现权衡关系,占比32.73%,绿洲系统中调节服务与其他服务呈现权衡关系,占比18.18%。     

部分国家和地区分级诊疗特点及启示

通过剖析部分国家和地区分级诊疗的特点,即分级诊疗是医疗卫生服务体系健全的自然结果,分级诊疗的实质在于服务整合,合理的支付制度是分级诊疗的重要促进因素;提出以强基层、建机制的原则发展分级诊疗,将医疗机构分工合作、服务功能整合作为分级诊疗的重要路径,增强医保对医疗服务体系的影响力以促进分级诊疗等建议。     

Improving cell-free protein synthesis for stable-isotope labeling

Cell-free protein synthesis is suitable for stable-isotope labeling of proteins for NMR analysis. The Escherichia coli cell-free system containing potassium acetate for efficient translation (KOAc system) is usually used for stable-isotope labeling, although it is less productive than other systems. A system containing a high concentration of potassium l-glutamate (l-Glu system), instead of potassium acetate, is highly productive, but cannot be used for stable-isotope labeling of Glu residues. In this study, we have developed a new cell-free system that uses potassium d-glutamate (d-Glu system). The productivity of the d-Glu system is approximately twice that of the KOAc system. The cross peak intensities in the ¹H–¹⁵N HSQC spectrum of the uniformly stable-isotope labeled Ras protein, prepared with the d-Glu system, were similar to those obtained with the KOAc system, except that the Asp intensities were much higher for the protein produced with the d-Glu system. These results indicate that the d-Glu system is a highly productive cell-free system that is especially useful for stable-isotope labeling of proteins. Electronic Supplementary Material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.     

生态产业共生系统仿真研究

通过ABM方法研究生态产业共生系统,利用STARLOGO软件平台,并结合案例分析生态产业共生系统的宏观规律。研究结果表明,(1)对于规模相当的不同的生态产业共生系统,在资源输入一定情况下,直接利用输入资源的企业总规模大于对系统内废弃物再利用的企业总规模是有利于系统稳定的:(2)对于特定的生态产业共生系统,系统稳定性对系统参数改变时的敏感性是不一样的,其中对污染物产出指标最敏感,对污染物产生量与系统产出的比例关系其次,对资源输入指标最不敏感;(3)系统时间序列稳定性的变化主要由节点处企业Ⅱ的不稳定性导致。     

门诊预约服务体系建设中的问题与对策

门诊预约服务在政府的倡导下广泛开展,门诊预约服务体系的建设是现阶段的主要任务。预约体系包括信息系统、服务系统、管理系统和评价系统,各系统相互配合构成统一的整体。目前预约服务还面临着不少难题,对不同系统的主要问题和解决思路作一简要探讨。     

用于体外人工肝支持系统的肝细胞研究

目前,人工肝支持系统正在成为急性肝衰竭患者体外有效的肝支持治疗手段,其中以生物人工肝为主附加血或血浆灌流组成的体外组合型人工肝辅助装置最为人们关注,主要包含肝酶类、肝细胞成分、肝组织片及培养肝细胞系统等,其中又以对肝细胞培养系统的研究最为广泛。本文综述了国内外有关肝细胞的来源、培养方式、所需肝细胞数量等问题的研究进展。     

Co-expression of a prophage system and a plasmid system in Bacillus subtilis

A dual expression system for overexpressing two proteins by a single cell strain has been developed in Bacillus subtilis. This dual expression system combines the phi105MU331 prophage system and a plasmid system within a single cell. Protein expression by the prophage system is heat inducible, while that of the plasmid system is constitutive. Three candidate genes, BPN, BT, and amyE, all of Bacillus origin, were used as test models. Seven strains (BPN, BT, AMY, BS168K, MU331K, BPNK, and BTK) were constructed to investigate the influences of the prophage system and the plasmid system on each other, and to compare the efficiency of the individual expression systems with that of the dual expression system. Individually, the yield of the plasmid system is higher than that of the prophage system, which could be attributed to the constitutive nature of the expression of the plasmid system. Nonetheless, for the dual expression strains, the expression of two enzymes in a single fermentation run can reduce costs in facilities, manpower, and utilities. Fed-batch fermentation of BPNK strains confirmed the feasibility of applying this dual expression system in industrial-scale production.     

The blood vascular system in the head of the herring gull (Larus argentatus)

The structure and development of the blood vascular system in the head of the herring gull (Larus argentatus) have been studied using injection techniques and histological sections. Three different but interconnected divisions of the arterial system are recognized in the adult: the cerebral carotid artery system, the external ophthalmic artery system, and the external carotid artery system. Embryologically, the arterial system is characterized by changes in the relative development of these three divisions; the cerebral carotid system being the most prominent in the first half of the embryonic period. The venous system is divided into two parts, the rostral cephalic system and the caudal cephalic system, which drain separate regions of the head. The Rete ophthalmicum, which is an arteriovenous network associated with the external ophthalmic artery system, can be identified from the fifth day of incubation, and its development appears to be coupled with changes in the arterial supply to the eye. The possibility of a homology between the Rete ophthalmicum of birds and the Rete caroticum of mammals is briefly discussed.     

Escherichia coli K-12 mutants that allow transport of maltose via the beta-galactoside transport system.

We have isolated mutants of Escherichia coli that have an altered beta-galactoside transport system. This altered transport system is able to transport a sugar, maltose, that the wild-type beta-galactoside transport system is unable to transport. The mutation that alters the specificity of the transport system is in the lacY gene, and we refer to the allele as lacYmal. The lacYmal allele was detected originally in strains in which the lac genes were fused to the malF gene. Thus, as a result of gene fusion and isolation of the lacYmal mutation, a new transport system was evolved with regulatory properties and specificity similar to those of the original maltose transport system. Maltose transport via the lacYmal gene product is independent of all of the normal maltose transport system components. The altered transport system shows a higher affinity than the wild-type transport system for two normal substrates of the beta-galactoside transport system, thiomethyl-beta-D-galactoside and o-nitrophenyl-beta-D-galactoside.     

Difference in transport of leucine in attached and suspended 3T3 cells.

3T3 cells in subconfluent culture take up leucine through a transport system which has a relatively high affinity for leucine (M system). When the culture becomes confluent, the M system is turned off and leucine is transported by another system which has a low affinity for leucine (S system). The M system is reactivated by transferring the cells into subconfluent cultures. In suspension cultures 3T3 cells, initiated from confluent cultures, the M system is not activated and leucine is transported by the S system. In cells suspended from subconfluent culture, the M system continues to operate at a high level for four hours and then is gradually turned off. Tumor virus transformed 3T3 cells (SV3T3 and Py3T3) grow quite well in suspension culture and transport leucine both in monolayer and suspension through a high affinity system, with a high Vmax value. A derivative of 3T3, 3T3/41, which grows in suspension much more slowly than tumor virus transformed 3T3 cells, also takes up leucine through a high affinity transport system both in monolayer and suspension but its Vmax value is lower than that of the transformed cells.     

中国特色现代医院管理制度的基本框架与发展路径

建立现代医院管理制度是提高医院竞争力的紧迫要求,也是我国公立医院改革发展的必然趋势。从内部和外部两个方面对中国特色现代医院管理制度进行了界定,强调现代医院外部管理制度重点是医院管理体制创新,现代医院内部管理制度的核心是建立医院的法人治理结构和机制。阐述了中国特色现代医院管理制度的基本框架,并提出中国现代医院管理制度的发展路径,为构建理想的现代医院管理制度提供了思路。     

Modulation of dynamic parameters of muscle reflex by selective activation of its gamma system

The ability of the gamma system to modify the dynamics of the muscle reflex control system is investigated. The dynamics of the triceps surae muscle in decerebrate cat preparations with intact reflex loops were modulated by contralateral tibial and peroneal nerve stimulation. The parameters of the mathematical models representing the muscle reflex system were estimated by the least squares method. The behaviour of the mathematical models of the system, under various degrees of gamma system stimulation, was then studied in response to disturbance inputs. It is shown that the gamma motor system is an efficient agent for carrying out modifications in the dynamics of the muscle reflex system. The possible functional significance of this phenomenon within the framework of operation of the muscular control system is discussed with reference to optimal adaptive system concepts.     

在胶束非均相体系中竹红菌乙素光敏作用特征的ESR研究

竹红菌乙素（ＨｙｐｏｃｒｅｌｌｉｎＢ,简称ＨＢ）属于脂溶性醌类光敏剂。本文采用近代ＥＳＲ实验技术,探讨了ＨＢ在ＴｒｉｔｏｎＸ—１００胶束非均相体系中光敏反应原初过程的特征。首先证明,在非均相体系中,ＨＢ仍具有产生１Ｏ２的作用,进而证实,ＨＢ通过电子传递亦能产生ＨＢ－,Ｏ２－和·ＯＨ自由基。结果发现,ＨＢ在非均相胶束体系中,上述活性中间体（１Ｏ２和自由基）的相对产额均显著高于均相体系值。这表明,在非均相体系中,ＨＢ光敏反应激发能转移和电子传递具有新的特点和规律。据此推测,ＨＢ在生物非均相体系中的光敏损伤作用将会有新的特征。     

山水林田湖草生态保护修复的系统性认知

系统治理是山水林田湖草生态保护修复的核心,然而在工程实施和评估中如何有效落实和考核山水林田湖草生态保护修复的系统性仍是目前一大难题。通过厘清系统性与整体性的逻辑关系,从山水林田湖草生态保护修复的对象、主体及其耦合联系入手,明晰系统治理是山水林田湖草生态保护修复的必然选择,进而提出关键要素控制与全要素耦合相结合的治理思路,并以云南抚仙湖项目区为例阐明系统治理在山水林田湖草生态保护修复中的实践路径。最后,依据结构-功能复杂度、要素关联紧密度及其认知,将山水林田湖草治理系统分为形态系统、级联系统、过程-响应系统、控制系统等四级递进系统,从流域内和流域外的空间视角出发,提出基于“目标-约束-成本”的山水林田湖草生态保护修复系统性评估方法,为山水林田湖草系统治理的实施与考核提供核心科学支撑。     

植被系统中植物与环境因子相互作用的动态模拟

本文在综合考虑现有植被发展动态模型的基础上提出包含植被,环境因子,人类或其它外力干扰三者间相互作用情况下的植被系统一般动态模型,并从控制论的角度阐述了植被与环境因子间的耦合,反馈作用。最后以线性逼近和微分拟合的方法求取模型的局部解,进而作出外延预测。实例分析表明,模型预测对实际观测有较好的跟踪性能。     

两种作物套种生态系统动态模型的建立及分析

本文主要建立小麦、大豆两种作物套种共生生态系统的Volterra方程模型．分析该模型得知,此生态系统是相互竞争的,其自身增长率因环境因素而受抑制,且是全局稳定的．其次计算出该生态系统在平衡状态处受到标准扰动之后,向平衡状态恢复的时间,有利套种作物生长的调控。     

Combined harvesting of a stage structured prey–predator model incorporating cannibalism in competitive environment

In this paper, we propose a prey–predator system with stage structure for predator. The proposed system incorporates cannibalism for predator populations in a competitive environment. The combined fishing effort is considered as control used to harvest the populations. The steady states of the system are determined and the dynamical behavior of the system is discussed. Local stability of the system is analyzed and sufficient conditions are derived for the global stability of the system at the positive equilibrium point. The existence of the Hopf bifurcation phenomenon is examined at the positive equilibrium point of the proposed system. We consider harvesting effort as a control parameter and subsequently, characterize the optimal control parameter in order to formulate the optimal control problem under the dynamic framework towards optimal utilization of the resource. Moreover, the optimal system is solved numerically to investigate the sustainability of the ecosystem using an iterative method with a Runge–Kutta fourth-order scheme. Simulation results show that the optimal control scheme can achieve sustainable ecosystem. Results are analyzed with the help of graphical illustrations.     

Anaerobic fumarate transport in Escherichia coli by an fnr-dependent dicarboxylate uptake system which is different from the aerobic dicarboxylate uptake system.

Escherichia coli grown anaerobically with fumarate as electron acceptor is able to take up C4-dicarboxylates by a specific transport system. The system differs in all tested parameters from the known aerobic C4-dicarboxylate transporter. The anaerobic transport system shows higher transport rates (95 mumol/g [dry weight] per min versus 30 mumol/g/min) and higher Kms (400 versus 30 microM) for fumarate than for the aerobic system. Mutants lacking the aerobic dicarboxylate uptake system are able to grow anaerobically at the expense of fumarate respiration and transport dicarboxylates with wild-type rates after anaerobic but not after aerobic growth. Transport by the anaerobic system is stimulated by preloading the bacteria with dicarboxylates. The anaerobic transport system catalyzes homologous and heterologous antiport of dicarboxylates, whereas the aerobic system operates only in the unidirectional mode. The anaerobic antiport is measurable only in anaerobically grown bacteria with fnr+ backgrounds. Additionally, the system is inhibited by incubation of resting bacteria with physiological electron acceptors such as O2, nitrate, dimethyl sulfoxide, and fumarate. The inhibition is reversed by the presence of reducing agents. It is suggested that the physiological role of the system is a fumarate/succinate antiport under conditions of fumarate respiration.     

生命信息安全控制体系整体结构性构建与分析

在前期生命信息安全控制原理探讨的基础上,基于整体论的思考,旨在构思能表述生命信息安全控制体系实质内涵的几何图形。所作图呈圆台形,自上而下依次为2大部分(内在部分和外延部分),5个层次(特异性识别系统、泛特异性识别系统、皮肤黏膜、共生微生物及外环境开放接触面)。在圆台形生命信息安全控制体系中,圆台形的中心轴为生命信息安全控制轴;特异性识别系统、泛特异性识别系统、皮肤、黏膜和共生微生物组成内在部分;外延部分即外环境开放接触面;内在部分各部间以及与外延部分之间存在物质、能量、信息交流沟通传递的空间界面。特异性识别系统建立在泛特异性识别系统基础上,置于最顶端,寓意着生物进化高级发展的一种客观结局,泛特异性识别系统与特异性识别系统作为一个整体和共生微生物层次联系,其中安插皮肤、黏膜组织层次,符合宏生物与微生物之间存在的完全不可分割的相关关系客观事实。共生微生物层次举足轻重,所占份额最大,主导整个体系的稳定性,成为整个体系的基座。就上述5个层次及其相互关系的解析归纳,证明构建的圆台形几何图能真实客观反映出生命信息安全控制体系各层次之间完全不可分割、相互依存影响的关系。