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21.
Fluorescent Amplified Fragment Length Polymorphism Analysis of Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis Isolates 总被引:3,自引:0,他引:3 下载免费PDF全文
Karen K. Hill Lawrence O. Ticknor Richard T. Okinaka Michelle Asay Heather Blair Katherine A. Bliss Mariam Laker Paige E. Pardington Amber P. Richardson Melinda Tonks Douglas J. Beecher John D. Kemp Anne-Brit Kolst? Amy C. Lee Wong Paul Keim Paul J. Jackson 《Applied microbiology》2004,70(2):1068-1080
DNA from over 300 Bacillus thuringiensis, Bacillus cereus, and Bacillus anthracis isolates was analyzed by fluorescent amplified fragment length polymorphism (AFLP). B. thuringiensis and B. cereus isolates were from diverse sources and locations, including soil, clinical isolates and food products causing diarrheal and emetic outbreaks, and type strains from the American Type Culture Collection, and over 200 B. thuringiensis isolates representing 36 serovars or subspecies were from the U.S. Department of Agriculture collection. Twenty-four diverse B. anthracis isolates were also included. Phylogenetic analysis of AFLP data revealed extensive diversity within B. thuringiensis and B. cereus compared to the monomorphic nature of B. anthracis. All of the B. anthracis strains were more closely related to each other than to any other Bacillus isolate, while B. cereus and B. thuringiensis strains populated the entire tree. Ten distinct branches were defined, with many branches containing both B. cereus and B. thuringiensis isolates. A single branch contained all the B. anthracis isolates plus an unusual B. thuringiensis isolate that is pathogenic in mice. In contrast, B. thuringiensis subsp. kurstaki (ATCC 33679) and other isolates used to prepare insecticides mapped distal to the B. anthracis isolates. The interspersion of B. cereus and B. thuringiensis isolates within the phylogenetic tree suggests that phenotypic traits used to distinguish between these two species do not reflect the genomic content of the different isolates and that horizontal gene transfer plays an important role in establishing the phenotype of each of these microbes. B. thuringiensis isolates of a particular subspecies tended to cluster together. 相似文献
22.
Sahrawy M Avila C Chueca A Cánovas FM López-Gorgé J 《Journal of experimental botany》2004,55(408):2495-2503
The pea chloroplastic fructose-1,6-bisphosphatase (FBPase) antisense construct reduced the endogenous level of expression of the corresponding Arabidopsis thaliana gene. The reduction of foliar FBPase activity in the transformants T(2) and T(3) generation ranged from 20% to 42%, and correlated with lower levels of FBPase protein. FBPase antisense plants displayed different phenotypes with a clear increase in leaf fresh weight. Measurements of photosynthesis revealed a higher carbon-assimilation rate. Decreased FBPase activity boosted the foliar carbohydrate contents, with a shift in the sucrose:starch ratio, which reached a maximum of 0.99 when the activity loss was 41%. Nitrate reductase activity decreased simultaneously with an increase in glutamine synthetase activity, which could be explained in terms of ammonium assimilation regulation by sugar content. These results suggest the role of FBPase as a key enzyme in CO(2) assimilation, and also in co-ordinating carbon and nitrogen metabolism. 相似文献
23.
Gijs Teklenburg Madhuri Salker Mariam Molokhia Stuart Lavery Geoffrey Trew Tepchongchit Aojanepong Helen J. Mardon Amali U. Lokugamage Raj Rai Christian Landles Bernard A. J. Roelen Siobhan Quenby Ewart W. Kuijk Annemieke Kavelaars Cobi J. Heijnen Lesley Regan Jan J. Brosens Nick S. Macklon 《PloS one》2010,5(4)
Background
Pregnancy is widely viewed as dependent upon an intimate dialogue, mediated by locally secreted factors between a developmentally competent embryo and a receptive endometrium. Reproductive success in humans is however limited, largely because of the high prevalence of chromosomally abnormal preimplantation embryos. Moreover, the transient period of endometrial receptivity in humans uniquely coincides with differentiation of endometrial stromal cells (ESCs) into highly specialized decidual cells, which in the absence of pregnancy invariably triggers menstruation. The role of cyclic decidualization of the endometrium in the implantation process and the nature of the decidual cytokines and growth factors that mediate the crosstalk with the embryo are unknown.Methodology/Principal Findings
We employed a human co-culture model, consisting of decidualizing ESCs and single hatched blastocysts, to identify the soluble factors involved in implantation. Over the 3-day co-culture period, approximately 75% of embryos arrested whereas the remainder showed normal development. The levels of 14 implantation factors secreted by the stromal cells were determined by multiplex immunoassay. Surprisingly, the presence of a developing embryo had no significant effect on decidual secretions, apart from a modest reduction in IL-5 levels. In contrast, arresting embryos triggered a strong response, characterized by selective inhibition of IL-1β, -6, -10, -17, -18, eotaxin, and HB-EGF secretion. Co-cultures were repeated with undifferentiated ESCs but none of the secreted cytokines were affected by the presence of a developing or arresting embryo.Conclusions
Human ESCs become biosensors of embryo quality upon differentiation into decidual cells. In view of the high incidence of gross chromosomal errors in human preimplantation embryos, cyclic decidualization followed by menstrual shedding may represent a mechanism of natural embryo selection that limits maternal investment in developmentally impaired pregnancies. 相似文献24.
Stoff-Khalili MA Scholze R Morgan WR Metcalf JD 《Plastic and reconstructive surgery》2004,114(5):1280-8; discussion 1289-91
Subfascial placement of implants was introduced 3 years ago. Collected data reveal very promising short-term and long-term results in comparison with subglandular and subpectoral positioned implants. The clinical experiences of 69 breast augmentations in the subfascial position are reported. The indications for this technique are proposed. The incidence of complications is described from clinical experiences and compared with that for other methods. From January of 1998 through May of 2002, 328 patients underwent periareolar augmentation mammaplasty; 105 patients had a subglandular mammaplasty, 154 patients had a subpectoral mammaplasty, and from August of 1999 through May of 2002, 69 patients had a subfascial augmentation mammaplasty. The mean postoperative follow-up time was 3.6 years in the subglandular group, 3.5 years in the subpectoral group, and 2.9 years in the subfascial group. In comparing the results of the subglandular augmentation group with those of the subpectoral and subfascial augmentation groups, the total rate of complications diminished significantly. The long-term complications of severe capsular contracture, rippling, and nipple sensation and numbness in subglandular augmentation mammaplasty could be significantly reduced (p < 0.05). The subfascial augmentation mammaplasty unites all the advantages of the subpectoral augmentation mammaplasty but eliminates the disadvantages of increased postoperative discomfort and disturbing muscle movement of the breast. 相似文献
25.
Kriajevska M Fischer-Larsen M Moertz E Vorm O Tulchinsky E Grigorian M Ambartsumian N Lukanidin E 《The Journal of biological chemistry》2002,277(7):5229-5235
Metastasis-associated protein S100A4 (Mts1) induces invasiveness of primary tumors and promotes metastasis. S100A4 belongs to the family of small calcium-binding S100 proteins that are involved in different cellular processes as transducers of calcium signal. S100A4 modulates properties of tumor cells via interaction with its intracellular targets, heavy chain of non-muscle myosin and p53. Here we report identification of a new molecular target of the S100A4 protein, liprin beta1. Liprin beta1 belongs to the family of leukocyte common antigen-related (LAR) transmembrane tyrosine phosphatase-interacting proteins that may regulate LAR protein properties via interaction with another member of the family, liprin alpha1. We showed by the immunoprecipitation analysis that S100A4 interacts specifically with liprin beta1 in vivo. Immunofluorescence staining demonstrated the co-localization of S100A4 and liprin beta1 in the cytoplasm and particularly at the protrusion sites of the plasma membrane. We mapped the S100A4 binding site at the C terminus of the liprin beta1 molecule between amino acid residues 938 and 1005. The S100A4-binding region contains two putative phosphorylation sites by protein kinase C and protein kinase CK2. S100A4-liprin beta1 interaction resulted in the inhibition of liprin beta1 phosphorylation by both kinases in vitro. 相似文献
26.
Andrawiss M 《Genome biology》2002,3(10):reports4033.1-reports40334
A report on the twelfth Congress of Virology, part of 'The world of microbes', the joint meeting of the three divisions of the International Union of Microbiological Societies, Paris, France, 27 July to 1 August 2002. 相似文献
27.
We present here the genetic structure existing among five samples of the spotted sea bass Dicentrarchus punctatus, and we compare it to what prevails in the common sea bass D. labrax, a congeneric species sampled on almost the same geographical range. A genetic distance tree inferred from the polymorphism at six microsatellite loci shows a distinct pattern for the two species. D. labrax samples appears to be genetically more homogeneous with a global Fst of 3% as compared to the 10% observed at D. punctatus, indicating a lesser level of gene flow in the latter species. While appearing more differentiated, D. punctatus presents no clear geographical organisation of its genetic variability in opposition to D. labrax samples. This allows us to propose this pair of closely relative species as a good candidate for the study by comparative analysis of the biological and/or historical factors affecting genetic differentiation in marine environment. 相似文献
28.
Sergei Andreev Igor Andreev Elena Nikolaeva Anna Petrukhina Vladimir Zemskov Mariam Vafina 《International journal of peptide research and therapeutics》1998,5(2-3):63-66
Summary The V3 loop from HIV-1 envelope glycoprotein gp120 is involved in viral entry and determines the cellular tropism and HIV-1-induced
cell-cell fusion. Earlier we have shown that V3 loop peptides representing the sequences of syncytia-inducing HIV strains
have high membranotropic activity. These peptides caused the lysis of liposomes of various lipid compositions, could fuse
negatively charged liposomes and induced hemolysis of erythrocytes. In contrast, peptides mimicking the sequences of non-syncytia-inducing
viruses showed no lytic or fusion activities at the same concentrations. Now we have found that the V3 loop synthetic peptides
containing the conserved GPGR region, derived from T-lymphotropic strains (BRU and MN), as opposed to peptides containing
the GPGQ region, are able to cause a pronounced membrane permeabilization (dissipation of the ΔpH and the Δψ) of human peripheral
blood lymphocytes, erythrocytes and plasma membrane vesicles at micromolar concentrations with a dose-dependent kinetics.
Analysis of the secondary structures of the peptides by circular dichroism revealed conformational changes in V3 loop peptides
depending on solvent hydrophobicity: from random coil in water to an α-helix/β-sheet conformation in trifluoroethanol. Such
structural changes of the V3 loop together with the membrane insertion of the gp41 N-terminal fusion peptide may promote the
formation of the fusion pore during virus-cell fusion. 相似文献
29.
Muhammad Farooq Sabar Mustansara Yaqub Mohsin Ahmad Khan Nadeem Ahmad Muhammad Usman Ghani Mariam Shahid 《International journal of peptide research and therapeutics》2010,16(4):239-245
Efficacy of proteins can be enhanced by using polyethylene glycol (PEG) conjugation (PEGylation) to the protein molecules.
Mobile non-toxic PEG chains conjugated to bio-therapeutics increase their hydrodynamic volume and in turn can prolong their
plasma retention time and increase their solubility. An important aspect of PEGylation is the selection of PEG molecule with
suitable structure and molecular weight. In this study, conceiving the idea that branched PEG-conjugates show superior efficacy
over the linear PEG-conjugates, a tri-branched PEG-interferon (mPEG3L2-IFN) was synthesized by reacting a 30 KDa tri-branched mPEG3L2-NHS reagent with IFN to improve its pharmacokinetic properties and reduce the loss of in vitro bioactivity (which is generally
exhibited by PEGylation) of the conjugated protein to some extent. The PEGylation procedure was optimized in terms of concentration
and molar ratios of reactants, reaction time, temperature and pH conditions of the reaction mix. The conjugate was purified
by cation exchange chromatography and characterized by SDS-PAGE and SE-HPLC. Trypsin digestion of mPEG3L2-IFN indicated a single site specificity of PEGylation. Anti viral bioactivity of mPEG3L2-IFN was found to be 2.38 × 107 IU/mg which is approximately 9.52% of native IFNα2 (2.5 × 108 IU/mg) and better than PEGasys from Roche Pharma. Therefore, it is reported that the tri-branched mPEG3L2-NHS reagent has the potential to be used to conjugate proteins for the promising therapeutic results. 相似文献
30.
Mahmood Hossain Siddique Mohammad Raqibul Hasan Rubaiot Abdullah S. M. Costello Liam Matieu Henry Iqbal Md. Zaheer Akhter Mariam 《Wetlands Ecology and Management》2019,27(4):553-569
Wetlands Ecology and Management - Bangladesh has the single largest tract of naturally growing mangrove forest as well as the world’s largest manmade mangrove forest on newly accreted land in... 相似文献