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61.
The ability of carbon nanotubes (CNTs) to undergo surface modification allows them to form nanocomposites (NCs) with materials such as polymers, metal nanoparticles, biomolecules, and metal oxides. The biocidal nature, protein fouling resistance, and fouling release properties of CNT-NCs render them the perfect material for biofouling prevention. At the same time, the cytotoxicity of CNT-NCs can be reduced before applying them as substrates to promote biofilm formation in environmental biotechnology applications. This paper reviews the potential prospects of CNT-NCs to accomplish two widely varying objectives in environmental engineering applications: (i) preventing biofouling, and (ii) promoting the formation of desirable biofilms on materials surface. This paper addresses practical issues such as costs, risks to human health, and ecological impacts that are associated with the application, development and commercialization of CNT-NC technology.  相似文献   
62.

Background  

Human insulin-like growth factor-I (hIGF-I) is a growth factor which is highly resemble to insulin. It is essential for cell proliferation and has been proposed for treatment of various endocrine-associated diseases including growth hormone insensitivity syndrome and diabetes mellitus. In the present study, an efficient plant expression system was developed to produce biologically active recombinant hIGF-I (rhIGF-I) in transgenic rice grains.  相似文献   
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64.
A novel approach to the design of sensitive fluorescent probes for nucleic acids detection is proposed. Suitable modifications of tri- and pentamethine cyanine dyes in the polymethine chain and/or in the heterocyclic residues can result in a significant decrease in unbound dye fluorescence intensity and an increase in dye emission intensity in the presence of DNA compared to the unsubstituted dye. The sharp enhancement in the fluorescence intensity upon dye interaction with double-stranded DNA permits the application of the modified tri- and pentamethine dyes as fluorescent probes in double-stranded DNA detection in homogeneous assays.  相似文献   
65.
The role of sexual dimorphic adipose tissue fat accumulation in the development of insulin resistance is well known. However, whether vitamin A status and/or its metabolic pathway display any sex- or depot (visceral/subcutaneous)-specific pattern and have a role in sexual dimorphic adipose tissue development and insulin resistance are not completely understood. Therefore, to assess this, 5 weeks old Wistar male and female rats of eight from each sex were provided either control or diabetogenic (high fat, high sucrose) diet for 26 weeks. At the end, consumption of diabetogenic diet increased the visceral fat depots (p < 0.001) in the males and subcutaneous depot (p < 0.05) in the female rats, compared to their sex-matched controls. On the other hand, it caused adipocyte hypertrophy (p < 0.05) of visceral depot (retroperitoneal) in the females and subcutaneous depot of the male rats. Although vitamin A levels displayed sex- and depot-specific increase due to the consumption of diabetogenic diet, the expression of most of its metabolic pathway genes in adipose depots remained unaltered. However, the mRNA levels of some of lipid droplet proteins (perilipins) and adipose tissue secretory proteins (interleukins, lipocalin-2) did display sexual dimorphism. Nonetheless, the long-term feeding of diabetogenic diet impaired the insulin sensitivity, thus affected glucose clearance rate and muscle glucose-uptake in both the sexes of rats. In conclusion, the chronic consumption of diabetogenic diet caused insulin resistance in the male and female rats, but did not corroborate with sexual dimorphic adipose tissue fat accumulation or its vitamin A status.  相似文献   
66.
The first computational study of the folding and dynamics of a hydrophobic β-hairpin containing a central heterochiral diproline segment is reported. Linear hydrophobic sequences containing centrally positioned diproline motifs, heterochiral (DL/LD) and homochiral (LL/DD)), are investigated for their ability to form β-hairpins. Heterochiral diproline motifs (LD/DL) reveal the formation of stable β-hairpins with the backbone adopting β-turn conformation and the formation of backbone hydrogen bonds with antiparallel cross-strand registry, whereas the homochiral diproline (LL/DD) containing sequences tend to adopt PPII helix conformation. The competition between the β-turn formation and the backbone H-bond ladder of the antiparallel β-strands in heterochiral diproline containing sequences is employed to validate the hypothesis that β-turn formation precedes inter-strand registry in the folding of a β-hairpin (“zipper” mechanism). The observation of noncanonical hydrogen bonds leads to a folded β-hairpin-like conformation and points to the existence of relatively stable transition state intermediates, between the unfolded (extended) and folded (β-hairpin) states. The MD simulations are in excellent agreement with the experimental studies on the model system and constitute the very first computational investigation of the folding and dynamics of a completely hydrophobic synthetic β-hairpin containing heterogeneous residues of mixed chirality.  相似文献   
67.
68.

Background  

The fatty acids of anaerobic ammonium oxidizing (anammox) bacteria contain linearly concatenated cyclobutane moieties, so far unique to biology. These moieties are under high ring strain and are synthesised by a presently unknown biosynthetic pathway.  相似文献   
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70.

Background  

Analysis of heart rate variation (HRV) has become a popular noninvasive tool for assessing the activities of the autonomic nervous system (ANS). HRV analysis is based on the concept that fast fluctuations may specifically reflect changes of sympathetic and vagal activity. It shows that the structure generating the signal is not simply linear, but also involves nonlinear contributions. These signals are essentially non-stationary; may contain indicators of current disease, or even warnings about impending diseases. The indicators may be present at all times or may occur at random in the time scale. However, to study and pinpoint abnormalities in voluminous data collected over several hours is strenuous and time consuming.  相似文献   
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