区域生态安全格局研究进展

如何构建一个安全的区域生态格局,对土地可持续利用和区域生态安全有重要意义。区域生态安全格局的构建需要多学科的综合、多角度的分析和多种实现手段的结合,一般从景观格局优化、土地资源优化配置和景观恢复等途径入手,构建结构合理、功能高效、关系协调的区域生态安全模式。在分析国内外相关研究进展的基础上,对区域生态安全格局构建在数量优化、空间优化和综合优化等方法进行了总结,在此基础上提出了构建区域生态安全格局的思路：区域生态现状评价、情景预案与目标设定、区域生态安全格局设计、方案实施及其效果评价、方案调整与管理。未来区域生态安全格局研究的趋势表现为：空间优化模型的进一步改进;区域生态安全标准量化的探索;注重公众参与机制和不同组织水平利益相关者的协调。     

Airway imaging in disease: Gimmick or useful tool?

Airway remodeling is an important pathophysiological mechanism in a variety of chronic airway diseases. Historically investigators have had to use invasive techniques such as histological examination of excised tissue to study airway wall structure. The last several years has seen a proliferation of relatively noninvasive techniques to assess the airway branching pattern, wall thickness, and more recently, airway wall tissue components. These methods include computed tomography, magnetic resonance imaging, and optical coherence tomography. These new imaging technologies have become popular because to understand the physiology of lung disease it is important we understand the underlying anatomy. However, these new approaches are not standardized or available in all centers so a review of their validity and clinical utility is appropriate. This review documents how investigators are working hard to correct for inconsistencies between techniques so that they become more accepted and utilized in clinical settings. These new imaging techniques are very likely to play a frontline role in the study of lung disease and will, hopefully, allow clinicians and investigators to better understand disease pathogenesis and to design and assess new therapeutic interventions.     

金黄色葡萄球菌组分疫苗研究进展

临床上,耐药性的金黄色葡萄球菌日益增多,极其耐药的菌株甚至获得了超级耐药细菌的称谓,难以找到有效的抗菌素控制其感染,因而研制有效的疫苗来防治金黄色葡萄球菌感染显得更加重要。对研制开发的金黄色葡萄球菌荚膜多糖疫苗、纤维粘连结合蛋白疫苗、RNAⅢ激活蛋白疫苗以及核酸疫苗等进行了综述。     

RNA干涉（RNAi）技术应用于哺乳动物细胞的研究策略

RNAi作为新近发展起来的基因功能分析技术,近年来在哺乳动物细胞中的研究已取得了长足进展,且有着广泛的应用前景。对RNAi作用机制及RNAi实验操作技术的探讨是目前研究的热点。研究表明,哺乳动物细胞中的RNAi作用模式与植物有所不同。文章对RNAi作用机制、哺乳动物细胞RNAi实验的一般策略（包括靶siRNA序列选择、siRNA获取方法、siRNA转染、RNAi效果检测等）以及最新研究进展进行简述,以供类似工作的参考。     

蛋白质组学新技术及其在肿瘤标志物探索性研究中的应用

作为基因组研究的延伸,蛋白质组学已成为世界生命科学领域的一个极其活跃的部分,是功能基因组时代或后基因组时代的核心。近年来发展起来的几种蛋白质组学新技术克服了传统蛋白质组学技术的不足,有力推进了肿瘤标志物的探索性研究。尽管如此,我们仍应该强调对实验结果的验证,这一点在探索性研究中尤其重要,力求使结果更精确、可靠和有效。     

肿瘤免疫治疗专题报告 ——遇上最好的时代

肿瘤免疫治疗被称为继手术、放疗、化疗后第 4 种疗法,其可激活特异性、重要的免疫细胞,直接靶向性攻击癌症细胞,具有较高 的疗效和安全性,是目前全球肿瘤治疗研究的热点。报告采用文献调研、数据库检索、数据统计与分析等定性定量研究方法,从市场预测、 发展历程、国内外企业布局情况等方面对肿瘤免疫治疗药物领域进行多角度、多层次的分析,旨在为相关企业明确发展方向、确定产品研 发思路及制定市场策略提供线索和参考。     

复杂疾病基因定位策略与肿瘤易感基因鉴定

对于不存在某单一基因位点经典的孟德尔显性或隐性遗传模式的疾病,称为复杂疾病,肿瘤是最常见的类型之一 . 目前,以连锁和相关分析为基础的功能克隆、功能候选克隆、定位克隆、定位候选克隆、系统生物学等复杂疾病易感基因定位策略逐渐发展起来 . 其中,系统生物学策略由于整合了从 DNA 到蛋白质的各个层面的信息,对复杂疾病基因调控网络做出了良好诠释,使其成为最有潜力的方法之一 . 目前,虽然已有近 100 种肿瘤 / 遗传性癌综合症的易感基因被鉴定出来,但未来的复杂疾病易感基因定位工作仍充满了挑战 .     

Reinventing quantitative genetics for plant breeding: something old,something new,something borrowed,something BLUE

The goals of quantitative genetics differ according to its field of application. In plant breeding, the main focus of quantitative genetics is on identifying candidates with the best genotypic value for a target population of environments. Keeping quantitative genetics current requires keeping old concepts that remain useful, letting go of what has become archaic, and introducing new concepts and methods that support contemporary breeding. The core concept of continuous variation being due to multiple Mendelian loci remains unchanged. Because the entirety of germplasm available in a breeding program is not in Hardy–Weinberg equilibrium, classical concepts that assume random mating, such as the average effect of an allele and additive variance, need to be retired in plant breeding. Doing so is feasible because with molecular markers, mixed-model approaches that require minimal genetic assumptions can be used for best linear unbiased estimation (BLUE) and prediction. Plant breeding would benefit from borrowing approaches found useful in other disciplines. Examples include reliability as a new measure of the influence of genetic versus nongenetic effects, and operations research and simulation approaches for designing breeding programs. The genetic entities in such simulations should not be generic but should be represented by the pedigrees, marker data, and phenotypic data for the actual germplasm in a breeding program. Over the years, quantitative genetics in plant breeding has become increasingly empirical and computational and less grounded in theory. This trend will continue as the amount and types of data available in a breeding program increase.Subject terms: Plant sciences, Genetics     

After genomics,what proteomics tools could help us understand the antimicrobial resistance of Escherichia coli?

Proteomic approaches have been considerably improved during the past decade and have been used to investigate the differences in protein expression profiles of cells grown under a broad spectrum of growth conditions and with different stress factors including antibiotics. In Europe, the most significant disease threat remains the presence of microorganisms that have become resistant to antimicrobials and so it is important that different scientific tools are combined to achieve the largest amount of knowledge in this area of expertise. The emergence and spread of the antibiotic-resistant Gram-negative pathogens, such as Escherichia coli, can lead to serious problem public health in humans. E. coli, a very well described prokaryote, has served as a model organism for several biological and biotechnological studies increasingly so since the completion of the E. coli genome-sequencing project. The purpose of this review is to present an overview of the different proteomic approaches to antimicrobial-resistant E. coli that will be helpful to obtain a better knowledge of the antibiotic-resistant mechanism(s). This can also aid to understand the molecular determinants involved with pathogenesis, which is essential for the development of effective strategies to combat infection and to reveal new therapeutic targets. This article is part of a Special Issue entitled: Proteomics: The clinical link.     

红曲菌次生代谢产物生物合成途径及相关基因的研究进展

红曲菌(Monascus spp.)是我国重要的药食两用微生物资源之一,能够产生天然食品添加剂红曲色素、降血酯活性物质Monacolin K等有益次生代谢产物,但也能分泌真菌毒素桔霉素(Citrinin),红曲菌及其相关产品的安全性由此受到质疑.因此,如何促进红曲菌有益代谢产物的产生,减少或抑制桔霉素的产生成为广大科研工作者研究的重点方向.近年来,红曲菌的分子生物学研究有了较快的发展,红曲菌次生代谢产物生物合成及其调控的研究是热点.本文重点介绍红曲色素、Monacolin K和桔霉素生物合成途径及相关基因的研究进展,以期为有效调控红曲菌次生代谢产物的产生、提高红曲产品的安全性提供参考和借鉴.     

Kinetics: a tool to study molecular motors

Molecular motors are enzymes that couple the energy from nucleoside triphosphate hydrolysis to movement along a filament lattice. The three cytoskeletal motor superfamilies include myosin, dynein, and kinesin. However, in the last decade it has become apparent that the nucleic acid-based enzymes (DNA and RNA polymerases as well as the DNA helicases) share a number of mechanistic features in common with the microtubule and actin motors despite the fact that their cellular functions are so different. This review addresses the mechanistic approaches that have been used to study molecular motors. We discuss the basic biochemical techniques used to characterize a protein preparation, including active site determination and steady-state kinetics. In addition, we present the transient-state kinetic approaches used to define a mechanochemical cycle. We attempt to integrate the information obtained from kinetic studies within the context of motility results to provide a better understanding of the contribution of each approach for dissecting unidirectional force generation.     

Ecology, mythology and the organismic way of thinking in limnology

For laymen, the word 'ecology' has become naturally surrounded with mythological mist. The influence of mythological thinking on ecology as a science is not so evident, but it certainly exists and in some aspects it can hardly be overestimated. The idea of the organism as a model or matrix for shaping new knowledge about populations, communities and ecosystems is extremely important in the maintenance of mythological thinking in modern ecology. We may even consider the organismic ideas as a vehicle of mythology in modern ecology. to this article, the problem is illustrated with limnology - an advanced branch of ecology in which it is easier to see the connections and contradictions between the dominant approaches.     

Proliferation of anchorage-dependent contact-inhibited cells. II: experimental results and validation of the theoretical models

This study establishes that the cellular automata models developed in an earlier article capture the essential features of the proliferation process for anchorage-dependent contact-inhibited cells. Model predictions are in excellent agreement with experimental data obtained with bovine pulmonary artery endothelial cells. The models are particularly suitable for predictive purposes since they have no adjustable parameters. All model parameters can be easily obtained from a priori measurements. Our studies also show that proliferation rates are very sensitive to the spatial distributions of seed cells. The adverse effects of seeding heterogeneities become more pronounced as a cell population approaches confluency and they should be accounted for in experimental studies attempting to assess the response of cells to external stimuli.     

A review of surgical techniques for radical prostatectomy

Since the early 20th century, radical prostatectomy has been used in the treatment of prostate cancer. However, before the widespread acceptance of prostate-specific antigen screening, the majority of cancers were clinically advanced and not amenable to cure, so relatively few men were candidates for this procedure. Modern advances have contributed dramatically to the reduction of complications and morbidity associated with radical prostatectomy. As a result, the procedure has become the most common treatment selected by men with localized prostate cancer. This article reviews several issues regarding radical prostatectomy, including surgical techniques, cancer control, intraoperative localization of the cavernous nerves, patient selection, and laparoscopic versus robotic approaches.     

Signaling protein networks as targets of new antineoplastic drugs

In-depth analysis of molecular regulatory networks in cancer holds the promise of improved knowledge of the pathophysiology of tumor cells so that it will become possible to design a detailed molecular tumor taxonomy. This knowledge will also offer new opportunities for the identification and validation of key molecular tumor targets to be exploited for novel therapeutic approaches. Some signaling proteins have already been identified as such, e.g. c-Myc, Cyclin D1, Bcl-XL, kinases and some nuclear receptors. This has led to the successful development of a few function-modulatory drugs (Glivec, SERM, Iressa), providing proof-of-principle of the validity of this approach. Further developments are likely to derive from "-omic" approaches, aimed at the understanding of signaling networks and of the mechanism of action of newfound lead molecules. High-throughput screening of small drug-like molecules from combinatorial chemical libraries or from microbial extracts will identify novel, "intelligent" drug candidates. An additional medicinal chemistry strategy (via 40-50 unit rosary-bead chains) has the potential to be much more effective than small molecules in interfering with protein-protein interactions. This may lead to considerably higher selectivity and effectiveness compared with historical approaches in drug discovery.     

Nanotechnology,bionanotechnology and microbial cell factories

Nanotechnology is increasingly using both materials and nano-objects synthesized by living beings, most of them produced by microbial cells. Emerging technologies and highly integrative approaches (such as 'omics and systems biology), that have been largely proven successful for the production of proteins and secondary metabolites are now expected to become fully adapted for the improved biological production of nanostructured materials with tailored properties. The so far underestimated potential of microbial cell factories in nanotechnology and nanomedicine is expected to emerge, in the next years, in the context of novel needs envisaged in the nanoscience universe. This should prompt a careful revisiting of the microbial cell factories as the most versatile biological platforms to supply functional materials for nanotechnological applications.     

Continuum electrostatic methods applied to pH-dependent properties of antibody-antigen association

Protein association events are a critical component of the functioning of biological systems. Antibody/antigen association, which involves extraordinarily specific interactions, has been a paradigm for the study of structural factors and intermolecular forces controlling protein-protein association. As new experimental approaches to the study of antibody/antigen affinity have become routine, and as more structures of complexes of antibodies and their antigens have become available, it has become possible to use computational approaches to study these interactions. Electrostatic interactions are known to play an important role in protein complex formation. In this review, we focus on the use of continuum electrostatic methods to compute pH-dependent properties of proteins and discuss the use of these methods in the study of antibody/antigen complexes.     

Asymptotic behavior in a deterministic epidemic model

The effects of a periodic contact rate and of carriers are considered for a generalization of Bailey's simple epidemic model. In this model it is assumed that individuals become susceptible again as soon as they recover from the infection so that a fixed population can be divided into a class of infectives and a class of susceptibles which vary with time. If the contact rate is periodic, then the number of infectives as time approaches infinity either tends to zero or is asymptotically periodic depending on whether the total population size is less than or greater than a threshold value. The behavior for large time of the number of infectives is determined for three modifications of the model which involve carriers.     

From artificial kidneys to artificial hearts and beyond: new developments offer great hope

Artificial organs have already become an important part of medical care, and with the advent of new devices, materials, and approaches, either in development or already on the market, they will become even more commonplace in the future.     

Parameter inference for discretely observed stochastic kinetic models using stochastic gradient descent

Background  

Stochastic effects can be important for the behavior of processes involving small population numbers, so the study of stochastic models has become an important topic in the burgeoning field of computational systems biology. However analysis techniques for stochastic models have tended to lag behind their deterministic cousins due to the heavier computational demands of the statistical approaches for fitting the models to experimental data. There is a continuing need for more effective and efficient algorithms. In this article we focus on the parameter inference problem for stochastic kinetic models of biochemical reactions given discrete time-course observations of either some or all of the molecular species.