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71.
Linkage mapping and genetic diversity studies with DNA markers in plant species assume that comigrating bands are identical, or at least that they have homologous sequences. To test this assumption in a plant with a large genome, sequence identities of 7 polymorphic amplified fragment length polymorphism (AFLP) markers of garlic, previously used to estimate similarity in genetic diversity studies, were characterized. Among 37 diverse garlic clones, 87 bands from these 7 polymorphisms were excised, amplicons were cloned, and 2 to 6 colonies were sequenced from each band, to yield a total of 191 DNA amplicons. Of these 87 bands, 83 bands (95.4%) contained AFLP amplicons that were identical or highly homologous to the typical marker of that band; only 4 bands contained amplicons with little homology to the same-sized amplicons of other garlic clones. Of these 83 bands, 64 (73.6%) contained only highly homologous amplicons (>90% sequence identity), whereas 19 (21.8%) contained both homologous and nonhomologous amplicons, with sequence identities less than 60%. Of the 37 nonhomologous amplicons identified, 25 (67.5%) differed in length from other amplicons in the band. Sequence conservation of AFLP amplicons followed patterns similar to phylogenetic relationships among garlic clones, making them useful for developing simple PCR-based markers in genetic mapping and diversity assessment.  相似文献   
72.
Carbonic anhydrases (CA: Carbonate hydrolase; E, C,4.2.1.1) from leaves Vicia canencens were purified and were characterized. The purification level of enzyme was 76-fold. The optimum temperature of this enzyme was 70 degrees C. pH optimum was 9.2. Each of the enzyme molecules was a decamer having MW of 262,000 and the subunit MW was 26,400.  相似文献   
73.
New data and records of the genus Chrysotoxum Meigen, 1803 are reported, arising from taxonomic and faunistic examination of adult specimens collected from 1920 to 2011 from four northeastern provinces of Turkey (Erzurum, Bayburt, Kars, and Artvin), and from the neighboring countries of Armenia, Azerbaijan and Iran. Three new species are described: Chrysotoxum antennalis Vuji?, Nedeljkovi? &; Hayat sp. n., C. clausseni Vuji?, Nedeljkovi? &; Hayat sp. n. and C. persicum Vuji?, Nedeljkovi? &; Hayat sp. n. The first two are known only from northeastern Turkey, and the third also occurs in Armenia, Azerbaijan and Iran. These new species have in common an antenna with the basoflagellomere being shorter than the scape and pedicel together.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:4C264678-8E47-4DE0-AC7D-91DABC597BCD  相似文献   
74.
Multimodal signals enhance decision making in foraging bumble-bees   总被引:4,自引:0,他引:4  
Multimodal signals are common in nature and have recently attracted considerable attention. Despite this interest, their function is not well understood. We test the hypothesis that multimodal signals improve decision making in receivers by influencing the speed and the accuracy of their decisions. We trained bumble-bees (Bombus impatiens) to discriminate between artificial flowers that differed either in one modality, visual (specifically, shape) or olfactory, or in two modalities, visual plus olfactory. Bees trained on multimodal flowers learned the rewarding flowers faster than those trained on flowers that differed only in the visual modality and, in extinction trials, visited the previously rewarded flowers at a higher rate than bees trained on unimodal flowers. Overall, bees showed a speed-accuracy trade-off; bees that made slower decisions achieved higher accuracy levels. Foraging on multimodal flowers did not affect the slope of the speed-accuracy relationship, but resulted in a higher intercept, indicating that multimodal signals were associated with consistently higher accuracy across range of decision speeds. Our results suggest that bees make more effective decisions when flowers signal in more than one modality, and confirm the importance of studying signal components together rather than separately.  相似文献   
75.
76.
Hydrocarbon seeps provide inputs of petroleum hydrocarbons to widespread areas of the Timor Sea. Alkanes constitute the largest proportion of chemical components found in crude oils, and therefore genes involved in the biodegradation of these compounds may act as bioindicators for this ecosystem''s response to seepage. To assess alkane biodegradation potential, the diversity and distribution of alkane hydroxylase (alkB) genes in sediments of the Timor Sea were studied. Deduced AlkB protein sequences derived from clone libraries identified sequences only distantly related to previously identified AlkB sequences, suggesting that the Timor Sea maybe a rich reservoir for novel alkane hydroxylase enzymes. Most sequences clustered with AlkB sequences previously identified from marine Gammaproteobacteria though protein sequence identities averaged only 73% (with a range of 60% to 94% sequence identities). AlkB sequence diversity was lower in deep water (>400 m) samples off the continental slope than in shallow water (<100 m) samples on the continental shelf but not significantly different in response to levels of alkanes. Real-time PCR assays targeting Timor Sea alkB genes were designed and used to quantify alkB gene targets. No correlation was found between gene copy numbers and levels of hydrocarbons measured in sediments using sensitive gas chromatography-mass spectrometry techniques, probably due to the very low levels of hydrocarbons found in most sediment samples. Interestingly, however, copy numbers of alkB genes increased substantially in sediments exposed directly to active seepage even though only low or undetectable concentrations of hydrocarbons were measured in these sediments in complementary geochemical analyses due to efficient biodegradation.Alkanes are saturated hydrocarbons that are widespread in marine environments due to a variety of anthropogenic and natural sources. They constitute the major fraction of hydrocarbon components found in crude oils and refined petroleum and are also produced by various marine organisms (e.g., zooplankton) as cellular components (2, 44). Alkanes are considered as pollutants, with short-chained alkanes acting as solvents toward cellular membranes and other lipid components (34) while longer-chained alkanes may contribute to the formation of oil films and slicks that may limit nutrient and oxygen exchange (21). Importantly, alkanes also serve as important carbon and energy sources for some microorganisms. In marine environments, alkanes succumb to various removal and dispersal processes such as dissolution, photochemical oxidation, evaporation, adsorption, and sedimentation. However, the greatest removal pathway for alkanes in marine sediments is via biodegradation by bacteria (13). This mechanism also mediates the transfer of oil-derived carbon to higher trophic levels (28, 37), and therefore these bacteria have an important role in carbon cycling in environments subject to long-term inputs of hydrocarbons such as marine seep-associated ecosystems. Alkane biodegradation is mediated by a diverse range of marine bacteria using various electron acceptors although degradation generally proceeds at greater rates under aerobic conditions than under anaerobic conditions, where the process is relatively slow (8, 26).In the presence of oxygen, well-characterized alkane oxidation pathways are initiated by an activation step whereby oxygen is introduced to the alkane substrate before further catabolic steps can proceed. A number of oxygen-dependent alkane hydroxylase enzyme systems have been discovered that catalyze this initial step including the soluble di-iron methane monooxygenases and the membrane-bound copper-containing methane monooxygenases, both of which act upon short-chain alkanes (i.e., C1 up to C8). Integral membrane non-heme iron alkane hydroxylases (the alk system) that are related to the well-characterized AlkB of Pseudomonas putida GPo1 (also known as Pseudomonas oleovorans TF4-1 I) act upon longer-chain alkanes (i.e., C5 to C16) (40). Other systems exist that include alkane-hydroxylating cytochrome P450 enzymes in addition to other enzyme systems that are known to exist based purely on chemical analyses of metabolites formed during alkane degradation experiments (22, 25, 29); however, knowledge pertaining to the enzymes and genes involved as well as their importance in the environment is limited. Only recently have genes involved in the degradation of long-chain alkanes (e.g., C32 and C36) been identified in Acinetobacter sp. strain DSM 17874 (39) though there is no information about the presence or importance of such enzymes in the environment.Although various chemical and microbiological aspects of petroleum oil and alkane biodegradation in marine systems have been relatively well studied, there is a general lack of knowledge concerning the diversity or abundance of the functional genes involved. The biochemical and molecular aspects of alkB genes and the enzymes they encode have been relatively well studied, and this has enabled the development of molecular tools for the study of alkB genes in the environment (19). Elevated levels of hydrocarbons or the introduction of hydrocarbons to environments has been shown to increase gene copy numbers, indicating the potential use of alkB genes as bioindicators of oil pollution and/or biodegradation (16, 33, 36, 43). However, to date only one study has used culture-independent molecular methods to examine the diversity of alkB genes in a marine environment (20), and no studies have examined hydrocarbon-degrading genes where natural hydrocarbon seepage occurs.In this study, the diversity and relative abundance of alkB genes were examined in sediments of the Timor Sea, a region where natural seeps are sources of widespread petroleum hydrocarbons. It was hypothesized that (i) novel alkB genes may exist in this unique tropical marine environment, (ii) that variations in gene diversity would be found in sediments with different hydrocarbon levels, and (iii) that the abundance of certain alkB gene types may reflect the levels of measured hydrocarbons in sediments, and therefore this assay could be used as a complementary tool for monitoring petroleum inputs into sediments of the Timor Sea.  相似文献   
77.
Granulocyte–macrophage colony-stimulating factor (GM-CSF) is a cytokine used in the treatment of serious conditions resulting from chemotherapy and bone marrow transplantation such as neutropenia and aplastic anemia. Despite these effects, GM-CSF has a very short biological half-life, and it requires frequent injection during the treatment. Therefore, the cytokine production is possible in the body with plasmid-encoded GM-CSF (pGM-CSF) coding for cytokine administered to the body. However, the selection of the proper delivery system for the plasmid is important. In this study, two different delivery systems, encapsulated plasmid such as fucoidan–chitosan (fucosphere) and chitosan microspheres, were prepared and the particle physicochemical properties evaluated. Fucospheres and chitosan microspheres size ranges are 151–401 and 376–681 nm. The zeta potential values of the microspheres were changed between 8.3–17.1 mV (fucosphere) and +21.9–28.9 mV (chitosan microspheres). The encapsulation capacity of fucospheres changed between 84.2% and 94.7% depending on the chitosan molecular weight used in the formulation. In vitro plasmid DNA release from both delivery systems exhibited slower profiles of approximately 90–140 days. Integrity of released samples was checked by agarose gel electrophoresis, and any additional band was not seen. All formulations were analyzed kinetically. The calculated regression coefficients showed a higher r 2 value with zero-order kinetics. In conclusion, the characterizations of the microspheres can be modulated by changing the formulation variables, and it can be concluded that fucospheres might be a potential carrier system for the controlled delivery of GM-CSF encoding plasmid DNA.  相似文献   
78.
BackgroundThe aim of this study was to determine the levels of lipid peroxidation (MDA) and antioxidants such as reduced glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) in the blood serum of patients with cirrhosis and liver transplantation.MethodsIn this study, serum malondialdehyde acid (MDA) levels, superoxide dismutase (SOD), reduced glutathione (GSH), and catalase (CAT) activities were measured spectrophotometrically and compared to the results of the healthy control group.ResultsSOD, CAT and GSH activities were significantly decreased in the patient groups compared to the healthy control group (p<0.05). MDA levels were significantly higher in the patient group compared to the healthy control group (p <0.05).ConclusionsIn conclusion, this study demonstrated that oxidative stress may play an important role in the development of liver cirrhosis and in liver transplantation. This study is the first one to show how MDA, SOD, CAT and GSH levels change in liver cirrhosis and liver transplantation, while further studies are essential to investigate antioxidant enzymes and oxidative stress status in patients with cirrhosis and liver transplantation.  相似文献   
79.
Serum paraoxonase (PON1) is a key enzyme related to high‐density lipoprotein (HDL)‐cholesterol particle. It can prevent the oxidation of low‐density lipoprotein (LDL) and HDL. The present article focuses on the in vitro inhibition role of some antiepileptic drugs (AEDs) such as valproic acid, gabapentin, primidone, phenytoin, and levetiracetam on human paraoxonase (hPON1). Therefore, PON1 was purified from human serum with a specific activity of 3976.36 EU/mg and 13.96% yield by using simple chromatographic methods. The AEDs were tested at various concentrations, which showed reduced in vitro hPON1 activity. IC50 values for gabapentin, valproic acid, primidone, phenytoin, and levetiracetam were found to be 0.35, 0.67, 0.87, 6.3, and 53.3 mM, respectively. Ki constants were 0.261 ± 0.027, 0.338 ± 0.313, 0.410 ± 0.184, 10.3 ± 0.001, and 43.01 ± 0.003 mM, respectively. Gabapentin exhibited effective inhibitory activity as compared with the other drugs. The inhibition mechanisms of all compounds were noncompetitive.  相似文献   
80.
The promise of science lies in expectations of its benefits to societies and is matched by expectations of the realisation of the significant public investment in that science. In this paper, we undertake a methodological analysis of the science of biobanking and a sociological analysis of translational research in relation to biobanking. Part of global and local endeavours to translate raw biomedical evidence into practice, biobanks aim to provide a platform for generating new scientific knowledge to inform development of new policies, systems and interventions to enhance the public’s health. Effectively translating scientific knowledge into routine practice, however, involves more than good science. Although biobanks undoubtedly provide a fundamental resource for both clinical and public health practice, their potentiating ontology—that their outputs are perpetually a promise of scientific knowledge generation—renders translation rather less straightforward than drug discovery and treatment implementation. Biobanking science, therefore, provides a perfect counterpoint against which to test the bounds of translational research. We argue that translational research is a contextual and cumulative process: one that is necessarily dynamic and interactive and involves multiple actors. We propose a new multidimensional model of translational research which enables us to imagine a new paradigm: one that takes us from bench to bedside to backyard and beyond, that is, attentive to the social and political context of translational science, and is cognisant of all the players in that process be they researchers, health professionals, policy makers, industry representatives, members of the public or research participants, amongst others.  相似文献   
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