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The isolation of two new classes of human docosahexaenoic acid oxidation products, the neuroprostanes and the neurofurans, have been reported. Facile nomenclature systems that will allow the rational differentiation of each of the isomeric structures comprising the families of NeuroP's and NeuroF's, represented, respectively, by 17-F(4t)-NeuroP 1 and 10-epi-ST-Delta(15)-11-NeuroF 2 are presented.  相似文献   

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Tuberculosis, caused by Mycobacterium tuberculosis, kills approximately two million people each year. The infection is characterized by an inflammatory response culminating in the formation of a granuloma, a collection of immune cells that controls the infection. However, the granuloma can be the source of immunopathology that encourages transmission. Recent data support the idea that mycobacterial products can positively and negatively regulate the inflammatory response. Our contention is that induction of the immune response and subsequent granuloma formation is beneficial to the host for control of infection, and is also beneficial to the bacillus, as a place to hide and as a means for transmitting the infection to naive hosts.  相似文献   

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Although the global agricultural system will need to provide more food for a growing and wealthier population in decades to come, increasing demands for water and potential impacts of climate change pose threats to food systems. We review the primary threats to agricultural water availability, and model the potential effects of increases in municipal and industrial (M&I) water demands, environmental flow requirements (EFRs) and changing water supplies given climate change. Our models show that, together, these factors cause an 18 per cent reduction in the availability of worldwide water for agriculture by 2050. Meeting EFRs, which can necessitate more than 50 per cent of the mean annual run-off in a basin depending on its hydrograph, presents the single biggest threat to agricultural water availability. Next are increases in M&I demands, which are projected to increase upwards of 200 per cent by 2050 in developing countries with rapidly increasing populations and incomes. Climate change will affect the spatial and temporal distribution of run-off, and thus affect availability from the supply side. The combined effect of these factors can be dramatic in particular hotspots, which include northern Africa, India, China, parts of Europe, the western US and eastern Australia, among others.  相似文献   

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In a previous paper [9], we have given an algorithm for obtaining the time dependent solution of all polynomial moments of gene frequencies in neutral models. The recurrence formula for the moment generating functions obtained in [9] gives information about the eigenvalues and the eigenfunctions in neutral models. In this article, we solve the eigenvalue problem for the Kolmogorov backward equation for the case of neutral alleles under mutation pressure.  相似文献   

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Probability plotting methods for the analysis for the analysis of data   总被引:1,自引:0,他引:1  
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Du S  Lutkenhaus J 《Molecular cell》2012,46(3):239-240
In this issue of Molecular Cell,Kiekebusch et al. (2012) show that a novel regulatory mechanism of the ATPase cycle of MipZ, together with nonspecific DNA binding, generates the MipZ gradient that spatially regulates Z ring formation in Caulobacter crescentus.  相似文献   

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The Sit-to-Stand (STS) is an activity most people perform numerous times daily. Standing up deals with the transition from two stabilized postures, namely seated to standing, with movement of all body segments except the feet. During the STS the body's Center of Gravity (COG) is moved upward from a sitting position to a standing position without losing balance and requiring a good coordination of many muscles. Three main phases of the STS movement can be recognized. One begins to stand up by inclining the upper body forward, which moves body mass toward the feet in order to maintain balance after lift-off. Prior to leaving the chair, hip and knee extensor muscles are activated to provide antigravity support for these joints, this action is commonly referred to as "weight shift". Finally; after leaving the chair, the leg and trunk joints are straightened to achieve upright stance. The STS task can be considered of major importance for impaired and elderly people to achieve minimal mo- bility and independence. In this paper we detail a procedure for the design of assisting devices to be used for the STS. In par- ticular, an experimental procedure is described firstly to track and record point trajectories and the orientation of the trunk during the STS. This analysis is then used to get information for the design of assisting devices. A proposal and simulation results are presented for a novel mechatronic system. In particular, for the case under study experimental tests are used to drive the actua- tion system for the reported simulation. A functional mechatronic scheme is then proposed to control the device during its operation.  相似文献   

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In vitro whole-embryo culture of chick embryos, originally invented by New, has been widely used for studies of early embryogenesis. Here, a method for electroporation using the New culture and its derivatives is described, to achieve misexpression of exogenous gene in a temporally and spatially controlled manner in gastrulating chick embryos. Detailed information for the devices and procedures, and some experimental examples are presented.  相似文献   

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