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61.

Background  

Pearl millet [Pennisetum glaucum (L.) R. Br.] is a staple food and fodder crop of marginal agricultural lands of sub-Saharan Africa and the Indian subcontinent. It is also a summer forage crop in the southern USA, Australia and Latin America, and is the preferred mulch in Brazilian no-till soybean production systems. Use of molecular marker technology for pearl millet genetic improvement has been limited. Progress is hampered by insufficient numbers of PCR-compatible co-dominant markers that can be used readily in applied breeding programmes. Therefore, we sought to develop additional SSR markers for the pearl millet research community.  相似文献   
62.
The mouse skin cocarcinogens fluoranthene, pyrene, and undecane were used with the indirect-acting carcinogen, benzo(a)pyrene (BP), and the direct-acting alkylating carcinogen, ß-propiolactone (BPL), in an in vitro transformation assay. Dose response, cytotoxicity, and transformation studies with these compounds were performed with a subclone (A31-1-1) of the Balb/3T3 cell line. Transformation frequencies were found to increase with increasing concentrations of BP used up to 1.0 µg/ml or when BPL was used up to 4.0 µg/ml. A significant increase (P<0.05) in the transformation frequency over that seen with carcinogen alone was observed when cells were exposed to a combination of fluoranthene (4.0 µg/ml) and BP (0.063 µg/ml) or pyrene (5.0 µg/ml) and BP (0.063 µg/ml). Thus, the transformation frequency obtained with BP + fluoranthene was 3.8 × 10–4 compared to 1.2 × 10–4 when BP was tested alone. Similarly, the transformation frequency using BP + pyrene was 2.8 × 10–4 vs 1.2 × 10–4 when BP was tested alone. Undecane did not exert any cocarcinogenic effect with BP in the dose range tested. In this in vitro assay, no cocarcinogenic effect was observed when BPL was used with any of the above mouse skin cocarcinogens. All cells isolated from transformed foci showed characteristics of transformed cells including anchorage-independent growth.Abbreviations BP benzo(a)pyrene - BPL ß-propiolactone - CE cloning efficiency - CE50 median CE - RCE relative CE Department of Cell Biology, New York University Medical CenterInstitute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA.Contribution No. L217 from the Laboratory of Organic Chemistry and Carcinogenesis.  相似文献   
63.
Besides inactivating tumour suppressor activity in cells, mutations in p53 confer significant oncogenic functions and promote metastasis and resistance to anticancer therapy. A variety of therapies involving genetic and epigenetic signalling events regulate tumorogenesis and progression in such cases. Pharmacological interventions with HDAC inhibitors have shown promise in therapy. This work explores the changes in efficacy of the four HDAC inhibitors SAHA, MS-275, valproic acid and sodium butyrate on a panel of colon cancer cell lines – HCT116 (p53 wt), HCT116 p53-/-, HT29 and SW480 (with mutations in p53). Clonogenic assays, gene profiling and epigenetic expression done on these cells point to p53 dependent differential activity of the 4 HDAC inhibitors which also elevate methylation levels in p53 mutant cell lines. In silico modelling establishes the alterations in interactions that lead to such differential activity of valproic acid, one of the inhibitors considered for the work. Molecular Dynamic simulations carried out on the valproic acid complex ensure stability of the complex. This work establishes a p53 dependent epigenetic signalling mechanism triggered by HDAC inhibition expanding the scope of HDAC inhibitors in adjuvant therapy for p53 mutant tumours.  相似文献   
64.
Molecular Biology Reports - Rapamycin is hormetic in nature—it demonstrates contrasting effects at high and low doses. It is toxic at moderate/high doses, while it can restrain aging and...  相似文献   
65.
66.
Bifidobacteria play an important role in human health including the enhancement of resistance against infection in infants. To develop an inexpensive whey-based medium for Bifidobaterium bifidum, potential growth promoters — yeast extract, casein, bovine casein digest, tryptone, peptone and glucosamine — singly or in combinations, were evaluated for their bifidus growth-promoting activity. The effect of environmental conditions on growth in cheese whey was also evaluated. A whey-based medium for B. bifidum was formulated. Cheese whey supplemented with N-acetylglucosamine (1 mg/ml) and yeast extract (10 mg/ml) in the presence of sodium thioglycolate (0.1%) at pH 6.8 promoted the growth of B. bifidum at 37°C. Journal of Industrial Microbiology & Biotechnology (2000) 25, 177–179. Received 20 May 2000/ Accepted in revised form 20 July 2000  相似文献   
67.
Fish processing industries generate large quantities of fish scales as processing waste, if not treated leading to environmental pollution. Fish scales are hard to degrade, hence cause difficulty in waste management. In this context present study was made to utilize fish scales as substrate for the production of alkaline protease by Bacillus altitudinis GVC11 and subsequently amino acid rich aqua hydrolyzate. B. altitudinis GVC11 efficiently utilized five types of fish scales as substrates and produced maximum alkaline protease using Labeo rohita (28,150 U/mL) followed by Catla catla (23,320 U/mL) at 48 h and Cyprinus carpio (17,146 U/mL) Mugil cephalus (18,917 U/mL), Cirrhinus mrigala (12,430 U/mL) at 72 h. The HPLC analysis of protein hydrolyzate obtained after fermentation was enriched in essential amino acids, leucine, isoleucine, phenylalanine, lysine and non-essential amino acids, tyrosine, arginine and cysteine which can be used as animal feed supplement and organic fertilizer.  相似文献   
68.
Abstract

Feathers from poultry industries are considered a major pollutant and its degradation is a challenging problem due to its recalcitrant nature. The high cost of energy and loss of essential amino acids by conventional methods have paved a way for an environmentally benign approach using microbial keratinolytic proteases. The widespread application of keratinolytic proteases is limited due to autolysis and denaturation of the enzyme upon storage. Immobilization overcomes these disadvantages by adsorbing the enzyme onto a solid support. Recently, electrospun nanofibers have been used due to their increased surface area and porous structure. The biocompatible and hydrophilic polyvinyl alcohol (PVA) has been blended with biodegradable chitosan for immobilization in electrospinning. The present study focuses on feather degradation by immobilized keratinolytic proteases on electrospun nanofibers. The keratinolytic protease production was enhanced by using a media containing hydrolyzed feather under optimized conditions. The immobilized keratinolytic protease on electrospun PVA chitosan (PVA-Ch) nanofibers (100–150?nm diameter) degraded the chicken feathers with 88% efficiency at the end of 72?hr.  相似文献   
69.
The outer membrane of a Gram‐negative bacterium is a crucial barrier between the external environment and its internal physiology. This barrier is bridged selectively by β‐barrel outer membrane proteins (OMPs). The in vivo folding and biogenesis of OMPs necessitates the assistance of the outer membrane chaperone BamA. Nevertheless, OMPs retain the ability of independent self‐assembly in vitro. Hence, it is unclear whether substrate–chaperone dynamics is influenced by the intrinsic ability of OMPs to fold, the magnitude of BamA–OMP interdependence, and the contribution of BamA to the kinetics of OMP assembly. We addressed this by monitoring the assembly kinetics of multiple 8‐stranded β‐barrel OMP substrates with(out) BamA. We also examined whether BamA is species‐specific, or nonspecifically accelerates folding kinetics of substrates from independent species. Our findings reveal BamA as a substrate‐independent promiscuous molecular chaperone, which assists the unfolded OMP to overcome the kinetic barrier imposed by the bilayer membrane. We additionally show that while BamA kinetically accelerates OMP folding, the OMP primary sequence remains a vital deciding element in its assembly rate. Our study provides unexpected insights on OMP assembly and the functional relevance of BamA in vivo.  相似文献   
70.
Agrobacterium-mediated wheat transformation has been attempted employing various bacterial strains, different tissues and explants, and different methods of co-cultivation. Of the various tissues/explants employed, i.e., leaf base, actively growing callus cells, mature seeds and seedlings punctured at the mesocotyl region, the mature seeds emerged as the most suited material for Agrobacterium-mediated gene delivery. Strain A281 of A. tumefaciens was found to be most effective followed by strains A348 and GV2260. Although the GUS activity in tissues/explants co-cultivated with strain GV2260 was relatively low, it indicated an efficient splicing of the intron (inserted in the coding region of the uidA gene). Various genotypes, namely, HD2329, Arjun and CPAN1676 were also screened for susceptibility against Agrobacterium strains and NPTII activity could be demonstrated in all of them, with minor variations.  相似文献   
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