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111.
Ger MJ Chen CH Hwang SY Huang HE Podile AR Dayakar BV Feng TY 《Molecular plant-microbe interactions : MPMI》2002,15(8):764-773
Hypersensitive response-assisting protein (HRAP) has been previously reported as an amphipathic plant protein isolated from sweet pepper that intensifies the harpin(Pss)-mediated hypersensitive response (HR). The hrap gene has no appreciable similarity to any other known sequences, and its activity can be rapidly induced by incompatible pathogen infection. To assess the function of the hrap gene in plant disease resistance, the CaMV 35S promoter was used to express sweet pepper hrap in transgenic tobacco. Compared with wild-type tobacco, transgenic tobacco plants exhibit more sensitivity to harpin(Pss) and show resistance to virulent pathogens (Pseudomonas syringae pv. tabaci and Erwinia carotovora subsp. carotovora). This disease resistance of transgenic tobacco does not originate from a constitutive HR, because endogenous level of salicylic acid and hsr203J mRNA showed similarities in transgenic and wildtype tobacco under noninfected conditions. However, following a virulent pathogen infection in hrap transgenic tobacco, hsr203J was rapidly induced and a micro-HR necrosis was visualized by trypan blue staining in the infiltration area. Consequently, we suggest that the disease resistance of transgenic plants may result from the induction of a HR by a virulent pathogen infection. 相似文献
112.
A simple and concomitant esterification method for the synthesis of methyl, ethyl, t-butyl, benzyl, and 9-fluorenylmethyl esters of Fmoc-/Boc-/Z-beta-homoamino acids employing Fmoc-/Boc-/Z-alpha-aminodiazoketones by Wolff rearrangement is described. The method offers good yield with purity. 相似文献
113.
Sharma VM Prasanna P Seshu KV Renuka B Rao CV Kumar GS Narasimhulu CP Babu PA Puranik RC Subramanyam D Venkateswarlu A Rajagopal S Kumar KB Rao CS Mamidi NV Deevi DS Ajaykumar R Rajagopalan R 《Bioorganic & medicinal chemistry letters》2002,12(17):2303-2307
In our endeavor to design and synthesize novel anticancer agents, a new series of indoloquinazoline compounds were prepared and tested initially for anticancer activity in vitro against a panel of human cancer cell lines. Most of these compounds exhibited cytotoxic activity in in vitro screens. Compounds were selected and further evaluated using a modified Hollow Fiber Assay for their preliminary in vivo activity against 12 cell lines implanted in the subcutaneous and intraperitoneal compartments in mice. The results indicate that these compounds may constitute a new class of anticancer agents. 相似文献
114.
Ridley CP Reddy MV Rocha G Bushman FD Faulkner DJ 《Bioorganic & medicinal chemistry》2002,10(10):3285-3290
In order to explore the influence of sulfate groups on the bioactivity profiles of marine alkaloids of the lamellarin class, three such alkaloids, lamellarin alpha, lamellarin alpha 13,20-disulfate and lamellarin H, were synthesized and their activities against HIV-1 integrase and cancer cell lines were compared with those of lamellarin alpha 20-sulfate, which is a selective inhibitor of HIV-1 integrase. Lamellarin alpha does not inhibit HIV-1 integrase but shows moderate cytotoxicity with good cell line selectivity. Lamellarin alpha 13,20-disulfate is a moderate inhibitor of both HIV-1 integrase and cancer cell lines. Lamellarin H is a more potent inhibitor of HIV-1 integrase but lacked the specificity required to be medicinally useful. 相似文献
115.
Plant root mucilage is known to enhance soil quality by contributing towards the soil carbon pool, soil aggregation, detoxification of heavy metal ions and interactions with rhizospheric microflora. Mucilage consists of many monosaccharide units, including fucose which can be used as an indicator for plant root based polysaccharides. This is the first report of an immunological technique developed to use anti-fucose antibodies as markers for probing and localizing fucosyl residues in mucilage polysaccharide and, in turn, for localization of plant root mucilage. Fucose was complexed with bovine serum albumin to raise antibodies against fucose. A fucose-directed antibody was shown to cross-react with root cap mucilages from grasses. This antibody was used to localize root mucilage polysaccharide in maize and wheat root caps using immunogold electron microscopy. Abundant labelling could be localized on the cell wall, and in the intercellular matrix and vesicles of the peripheral root cap cells. Labelling was less intense in cells towards the centre of the root cap tissue. Control experiments confirmed that immunogold localization of fucose was specific and reliable. 相似文献
116.
Babu E Takeda M Narikawa S Kobayashi Y Enomoto A Tojo A Cha SH Sekine T Sakthisekaran D Endou H 《Biochimica et biophysica acta》2002,1590(1-3):64-75
The purpose of this study was to investigate the characteristics of ochratoxin A (OTA) transport by multispecific human organic anion transporter 4 (hOAT4) using mouse proximal tubule cells stably transfected with hOAT4 (S(2) hOAT4). Immunohistochemical analysis revealed that hOAT4 protein was localized to the apical side of the proximal tubule. S(2) hOAT4 expressed hOAT4 protein in the apical side as well as basolateral side and the cells were cultured on the plastic dish for experiments. S(2) hOAT4 exhibited a time- and concentration-dependent, and a saturable increase in OTA uptake, with an apparent K(m) value of 22.9+/-2.44 microM. The OTA uptakes were inhibited by several substrates for the OATs. Probenecid, piroxicam, octanoate and citrinin inhibited OTA uptake by hOAT4 in a competitive manner (K(i)=44.4-336.4 microM), with the following order of potency: probenecid > piroxicam > octanoate >citrinin. The efflux of OTA by S(2) hOAT4 was higher than that by mock. Addition of OTA resulted in slight decrease in viability of S(2) hOAT4 compared with mock. These results indicate that hOAT4 mediates the high-affinity transport of OTA on the apical side of the proximal tubule, whereas the transport characteristics of OTA are distinct from those by basolateral OATs. 相似文献
117.
Antimicrobial constituents from the rhizomes of Rheum emodi 总被引:4,自引:0,他引:4
The bioassay-guided chemical examination of the rhizomes of R. emodi resulted in the isolation of two new oxanthrone esters, revandchinone-1, revandchinone-2, a new anthraquinone ether revandchinone-3 and a new oxanthrone ether, revandchinone-4. Their structures were established based on spectroscopic and degradative evidence. Occurrence of oxanthrone ether is reported for the first time. The anti bacterial and anti fungal activity of the isolates is studied. 相似文献
118.
The synthesis of three novel phosphonobile acids from natural bile acids is reported. The CMC of phosphonodeoxycholic acid (PDCA) at pH 8.2 was found to be lower than that of the parent deoxycholic acid (DCA). PDCA micelles were also found to have higher microviscosity compared to DCA micelles, suggesting higher hydrophobicity and tighter packing in the interior of PDCA micelles. PDCA aggregated further to form an aqueous gel at pH 4. 相似文献
119.
In preparing intracellular microbial samples for one- or two-dimensional electrophoresis, trichloroacetic acid (TCA) precipitation is frequently used to remove interfering compounds. Solubilization of TCA precipitate typically requires the addition of a number of chaotropes or detergents, in a multistep process, that requires hours to carry out. In this study, a simple, rapid, one-step method to solubilize TCA precipitated proteins is presented. Precipitated proteins are pretreated with 0.2 M NaOH for less than 5 min, followed by addition of standard sample solubilization buffer (SSSB). When compared to solubilization with SSSB alone, NaOH pretreatment of TCA-precipitated intracellular protein from Aspergillus oryzae and Escherichia coli shows an approximate 5-fold increase in soluble protein. In addition, two-dimensional gel electrophoresis on resolubilized proteins shows an equivalent number of proteins in samples with and without NaOH pretreatment. 相似文献
120.
Arzumanov A Stetsenko DA Malakhov AD Reichelt S Sørensen MD Babu BR Wengel J Gait MJ 《Oligonucleotides》2003,13(6):435-453