共查询到20条相似文献,搜索用时 15 毫秒
1.
《Nature biotechnology》2008,26(7):715
With follow-on biologics essentially dead in the water in the US, the decision of the world's largest generics manufacturer to invest in a platform for enhancing protein pharmacokinetics could pay dividends. 相似文献
2.
植物干旱生态生理的研究 总被引:29,自引:2,他引:27
随着科学研究的发展,涉猎的范畴越来越广,探索的问题越来越深,从而由一些单一的学科如物理学、化学、数学、生物学发展出许多边缘学科,如生物物理学、生物化学、生物 相似文献
3.
The majority of the world's population still live without access to healthy water and the contamination of drinking water with protozoan pathogens poses a serious threat to millions of people in the developing world. Even in the developed world periodic outbreaks of diarrhoeal diseases are caused by the protozoan parasites Cryptosporidium sp., Giardia duodenalis and Entamoeba histolytica. Thus, surveillance of drinking water is imperative to minimize such contaminations and ensure continuous supplies of healthy water world-wide. This article reviews the progress in technology for detection and surveillance of these important waterborne parasites. 相似文献
4.
Wackett LP 《Trends in biotechnology》2000,18(1):19-21
There is an increasing interest in environmental biotechnology owing to a worldwide need to feed the world's growing population and to maintain clean soil, air and water. The major technological developments are in plant and microbial biology. Plants can be more readily engineered for resistances that enhance yield or produce new products whereas microorganisms are exploited for their catalytic diversity and ease of genetic engineering. 相似文献
5.
Schubert CJ Coolen MJ Neretin LN Schippers A Abbas B Durisch-Kaiser E Wehrli B Hopmans EC Damsté JS Wakeham S Kuypers MM 《Environmental microbiology》2006,8(10):1844-1856
Inputs of CH(4) from sediments, including methane seeps on the continental margin and methane-rich mud volcanoes on the abyssal plain, make the Black Sea the world's largest surface water reservoir of dissolved methane and drive a high rate of aerobic and anaerobic oxidation of methane in the water column. Here we present the first combined organic geochemical and molecular ecology data on a water column profile of the western Black Sea. We show that aerobic methanotrophs type I are responsible for methane oxidation in the oxic water column and ANME-1- and ANME-2-related organisms for anaerobic methane oxidation. The occurrence of methanotrophs type I cells in the anoxic zone suggests that inactive cells settle to deeper waters. Molecular and biomarker results suggest that a clear distinction between the occurrence of ANME-1- and ANME-2-related lineages exists, i.e. ANME-1-related organisms are responsible for anaerobic methane oxidation below 600 m water depth, whereas ANME-2-related organisms are responsible for this process in the anoxic water column above approximately 600 m water depth. 相似文献
6.
W. STANLEY HARPOLE DANIEL L. POTTS† KATHARINE N. SUDING 《Global Change Biology》2007,13(11):2341-2348
The world's ecosystems are experiencing simultaneous changes in the supply of multiple limiting resources. Two of these, water and nitrogen (N) can strongly limit grassland production and can affect community composition and biogeochemical cycles in different ways. Grassland ecosystems in California may be particularly vulnerable to current and predicted changes in precipitation and N deposition, and ecosystem responses to potential interactive effects of water and N are not well understood. Here, we show strong colimitation of plant production resulting from factorial addition of water and N. In addition, water and N addition in combination led to increased dominance of the two most abundant grass species, while N addition regardless of water availability led to decreased species diversity. Late season carbon (C) flux response to water addition depended on N. Only plots that received additional water, but not N, still showed net ecosystem C uptake at the end of the experiment. Our results suggest that grassland ecosystem response to N deposition will be strongly dependent on future precipitation patterns. 相似文献
7.
STEPHANIE E. HAMPTON LYUBOV R. IZMEST'EVA† MARIANNE V. MOORE‡ STEPHEN L. KATZ§ BRIAN DENNIS¶ EUGENE A. SILOW† 《Global Change Biology》2008,14(8):1947-1958
High-resolution data collected over the past 60 years by a single family of Siberian scientists on Lake Baikal reveal significant warming of surface waters and long-term changes in the basal food web of the world's largest, most ancient lake. Attaining depths over 1.6 km, Lake Baikal is the deepest and most voluminous of the world's great lakes. Increases in average water temperature (1.21 °C since 1946), chlorophyll a (300% since 1979), and an influential group of zooplankton grazers (335% increase in cladocerans since 1946) may have important implications for nutrient cycling and food web dynamics. Results from multivariate autoregressive (MAR) modeling suggest that cladocerans increased strongly in response to temperature but not to algal biomass, and cladocerans depressed some algal resources without observable fertilization effects. Changes in Lake Baikal are particularly significant as an integrated signal of long-term regional warming, because this lake is expected to be among those most resistant to climate change due to its tremendous volume. These findings highlight the importance of accessible, long-term monitoring data for understanding ecosystem response to large-scale stressors such as climate change. 相似文献
8.
Increased use of the world's natural resources, including water bodies such as the Chesapeake Bay, has resulted in additional burdens being placed on them. If continued, unrestricted use of such resources continues, degradation will occur to such an extent that some areas will be unsuitable for economic, social, and environmental uses. Regional risk assessment strategies must be developed so that actual or perceived risks can be evaluated and predicted on a regional scale. This article presents an initial strategy for the Chesapeake Bay that may be useful to scientists, managers, and elected officials responsible for other bodies of water as well. This article reviews risk assessment practices and proposes a strategy that utilizes appropriate endpoints to ascertain and predict risk. 相似文献
9.
Alzheimer's disease (AD) affects approximately 10% of the world's population with 65 years of age, being the most common form of dementia in adults and is characterized by senile plaquets and cholinergic deficits. Many drugs currently used for the treatment of the AD are based on the improvement of cholinergic neurotransmission achieved by Acetylcholinesterase (AChE) inhibition, the enzyme responsible for acetylcholine hydrolysis. We have focused in this work on the usage of computer-aided molecular design by virtual screening, molecular dynamics with implicit and explicit water solvation, density functional, molecular interaction field studies, docking procedures, ADMET predictions in order to propose novel potential AChE inhibitor for the treatment of Alzheimer's disease. 相似文献
10.
沙漠蝗在史前期就是北非、西亚和印度等热带荒漠地区的河谷与绿洲上的农业大害虫。我国云南和西藏自治区的聂拉木均有沙漠蝗的分布记载 ,虽尚未发生灾害 ,但是沙漠蝗猖獗发生的最大扩散区已达我国云南接壤的缅甸和西藏接壤的尼泊尔、印度。故我国的西藏自治区和云南省的有关边防及农业植物保护机构应予以高度重视并加强监测和预警 ,谨防沙漠蝗的发生危害 相似文献
11.
A majority of the world's lakes are supersaturated with respect to carbon dioxide (CO(2) ). By experimental manipulation of the CO(2) concentration in supersaturated boreal lakes, we demonstrate that phytoplankton primary production was up to 10 times higher in supersaturated lake water in comparison with water with CO(2) at equilibrium concentrations and that CO(2) , together with nutrients, explained most of the variation in pelagic primary production and phytoplankton biomass over a wide variety of unproductive lakes. These results suggest that phytoplankton can be co-limited by CO(2) and nutrients in unproductive lakes. As import of terrestrial organic carbon and its subsequent microbial mineralisation in lakes is a driving force of CO(2) -supersaturation our results suggest that lake productivity and carbon cycling may respond to variations in terrestrial organic carbon export, (e.g. caused by land use or climate change) in ways not described before. 相似文献
12.
Molecular analyses of the sediment of the 11000-m deep Mariana Trench 总被引:10,自引:1,他引:10
Chiaki Kato Lina Li Jin Tamaoka Koki Horikoshi 《Extremophiles : life under extreme conditions》1997,1(3):117-123
We have obtained sediment samples from the world's deepest sea-bottom, the Mariana Trench challenger point at a depth of
10 898 m, using the new unmanned submersible Kaiko. DNA was extracted from the sediment, and DNA fragments encoding several prokaryotic ribosomal RNA small-subunit sequences
and pressure-regulated gene clusters, typically identifed in deep-sea adapted bacteria, were amplifed by the polymerase chain
reaction. From the sequencing results, at least two kinds of bacterial 16S rRNAs closely related to those of the genus Pseudomonas and deep-sea adapted marine bacteria, and archaeal 16S rRNAs related to that of a planktonic marine archaeon were identifed.
The sequences of the amplifed pressure-regulated clusters were more similar to those of deep-sea barophilic bacteria than
those of barotolerant bacteria. These results suggest that deep-sea adapted barophilic bacteria, planktonic marine archaea,
and some of the world's most widespread bacteria (the genus Pseudomonas) coexist on the world's deepest sea-bottom.
Received: October 10, 1996 / Accepted: March 3, 1997 相似文献
13.
The large-scale spatial distribution of seafloor fauna is still poorly understood. In particular, the bathyal zone has been identified as the key depth stratum requiring further macroecological research, particularly in the Southern Hemisphere. Here we analyze a large biological data set derived from 295 research expeditions, across an equator-to-pole sector of the Indian, Pacific, and Southern oceans, to show that the bathyal ophiuroid fauna is distributed in three broad latitudinal bands and not primarily differentiated by oceanic basins as previously assumed. Adjacent faunas form transitional ecoclines rather than biogeographical breaks. This pattern is similar to that in shallow water despite the order-of-magnitude reduction in the variability of environmental parameters at bathyal depths. A reliable biogeography is fundamental to establishing a representative network of marine reserves across the world's oceans. 相似文献
14.
The life and times of ivermectin - a success story 总被引:4,自引:0,他引:4
Since its introduction more than 20 years ago, ivermectin has proved to be one of the most successful therapeutic drugs in veterinary medicine, as well as the basis of one of the most successful public-health programmes of the past century. The drug arose from a unique international collaboration between the public and private sectors. The development process also incorporated the world's first and largest drug-donation programme and involved a unique association between governments, non-governmental organizations and industry. The drug is now being used, free of charge, in two global disease-elimination programmes that are benefiting millions of the world's poorest people. 相似文献
15.
Tea is the most popular beverage next to water, consumed by over two-thirds of the world's population. It is processed in different ways in different parts of the world to give green, black or oolong tea. Experimental studies have demonstrated the significant antimutagenic and anticlastogenic effects of both green and black tea and its polyphenols in multiple mutational assays. In the present review, we have attempted to evaluate and update the comparative antimutagenic and anticlastogenic effects of green tea, black tea and their polyphenols in different test systems, based on available literature. Existing reports have suggested that the protective effects of black tea is as good as green tea, however, more studies on black tea and its polyphenols are needed before a final conclusion can be made. 相似文献
16.
The crisis of emerging infectious disease stems from the absence of comprehensive taxonomic inventories of the world's parasites, which includes the world's pathogens. Recent technological developments raise hopes that the global inventory of species, including potential pathogens, can be accomplished in a timely and cost-effective manner. The phylogenetics revolution initiated by systematists provides a means by which information about pathogen transmission dynamics can be placed in a predictive framework. Increasingly, that information is widely available in digital form on the Internet. Systematic biology is well positioned to play a crucial role in efforts to be proactive in the arena of emerging parasitic and infectious diseases. 相似文献
17.
The world's major crops are deficient in lysine and several other amino acids essential for human and animal nutrition. Increasing the content of these amino acids in cereals, our major source of dietary energy, can help feed a global population whose reliance upon dietary protein is growing faster than crop yields. Here we document the heritable expression in rice, the world's major cereal crop, of tRNA(lys) species that introduce lysine at alternative codons during protein synthesis, resulting in a significant enrichment of the lysine content of proteins in rice seeds without changing the types or quantities of the seed storage proteins. 相似文献
18.
Who puts the tubercle in tuberculosis? 总被引:1,自引:0,他引:1
Russell DG 《Nature reviews. Microbiology》2007,5(1):39-47
Tuberculosis (TB), an illness that mainly affects the respiratory system, is one of the world's most pernicious diseases. TB currently infects one-third of the world's population and kills approximately 1.7 million people each year. Most infected individuals fail to progress to full-blown disease because the TB bacilli are 'walled off' by the immune system inside a tissue nodule known as a granuloma. The granuloma's primary function is one of containment and it prevents the dissemination of the mycobacteria. But what is the role of the TB bacillus in the progression of the granuloma? This Review explores how Mycobacterium tuberculosis influences granuloma formation and maintenance, and ensures the spread of the disease. 相似文献
19.
The extent of extinctions of mammals on islands 总被引:2,自引:0,他引:2
Many of the world's oceanic and oceanic-like islands possessed endemic mammal faunas before they were colonized by humans. These faunas, unbalanced and impoverished compared to continental faunas, usually lacked large mammalian carnivores. In virtually all cases, the arrival of humans and their domesticants and commensals on these islands is related to the extirpation of large numbers of endemic insular mammals. These extinction events affected at least 27% of autochthonous mammal species on the world's oceanic and oceanic-like islands. This percentage rises the 35% when volant mammals are excluded. This reduction in the natural biodiversity brought about the disappearance of several unique biological types that apparently never existed on the continents. 相似文献
20.
Identifying priority areas for conservation: a global assessment for forest-dependent birds 总被引:1,自引:0,他引:1
Limited resources are available to address the world's growing environmental problems, requiring conservationists to identify priority sites for action. Using new distribution maps for all of the world's forest-dependent birds (60.6% of all bird species), we quantify the contribution of remaining forest to conserving global avian biodiversity. For each of the world's partly or wholly forested 5-km cells, we estimated an impact score of its contribution to the distribution of all the forest bird species estimated to occur within it, and so is proportional to the impact on the conservation status of the world's forest-dependent birds were the forest it contains lost. The distribution of scores was highly skewed, a very small proportion of cells having scores several orders of magnitude above the global mean. Ecoregions containing the highest values of this score included relatively species-poor islands such as Hawaii and Palau, the relatively species-rich islands of Indonesia and the Philippines, and the megadiverse Atlantic Forests and northern Andes of South America. Ecoregions with high impact scores and high deforestation rates (2000-2005) included montane forests in Cameroon and the Eastern Arc of Tanzania, although deforestation data were not available for all ecoregions. Ecoregions with high impact scores, high rates of recent deforestation and low coverage by the protected area network included Indonesia's Seram rain forests and the moist forests of Trinidad and Tobago. Key sites in these ecoregions represent some of the most urgent priorities for expansion of the global protected areas network to meet Convention on Biological Diversity targets to increase the proportion of land formally protected to 17% by 2020. Areas with high impact scores, rapid deforestation, low protection and high carbon storage values may represent significant opportunities for both biodiversity conservation and climate change mitigation, for example through Reducing Emissions from Deforestation and Forest Degradation (REDD+) initiatives. 相似文献