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41.
Pneumonia due to Bordetella bronchiseptica in a cystic fibrosis patient: 16S rRNA sequencing for diagnosis confirmation 下载免费PDF全文
Wallet F Perez T Armand S Wallaert B Courcol RJ 《Journal of clinical microbiology》2002,40(6):2300-2301
Bordetella bronchiseptica was identified as an unusual etiologic agent of pulmonary recurrent exacerbations and pneumonia in a cystic fibrosis (CF) patient by utilizing a 16S rRNA molecular kit in our hospital's clinical laboratory. This method appears to be a useful approach for identifying new emerging CF pathogens when discrepancies exist between phenotypical tests. 相似文献
42.
Laurence Abrami Frédérique Tacnet Pierre Ripoche 《Pflügers Archiv : European journal of physiology》1995,430(3):447-458
Permeabilities to glycerol and small non-electrolytes of three Aquaporin 1 CHIP (AQP1) water channels were measured in AQP1 cRNA-injected Xenopus laevis oocytes and in human AQP1 channels reconstituted in proteoliposomes. By an osmotic swelling assay, significant increases of ethylene glycol, glycerol and 1,3-propanediol apparent permeability coefficients (Psolutes) were found in oocytes expressing human, rat and frog AQP1. p-Chloromercuribenzene sulphonate (PCMBS) and CuSO4 inhibited, by 95% and 58% respectively, apparent glycerol permeability (P
gly) in oocytes expressing human AQP1. pCMBS inhibition was reversed by -mercaptoethanol and CuSO4 inhibition was partly reversed by the Cu2+-binding peptide Gly-Gly-His. Tritiated glycerol uptakes confirmed the augmented P
gly value of AQP1 cRNA-injected oocytes. In contrast, no increases of urea, meso-erythritol, D- or L-threitol, xylitol and mannitol uptakes were detected. Stopped-flow light scattering experiments performed with human AQP1 proteoliposomes also revealed a much greater increase of P
gly than did those with protein-free liposomes; the initial rate of proteoliposomes also swelling was inhibited by 96.2% with HgCl2 and by 72.5% with CuSO4. In AQP1 cRNA-injected oocytes and in proteoliposomes, the value of the glycerol reflection coefficient was 0.74–0.80, indicating that water and glycerol share the same pathway. All these results provide strong evidence that water and certain small solutes permeate the AQP1 channels expressed at the surface of X. laevis oocytes or reconstituted in proteoliposomes. The urea exclusion suggests that the selectivity of the AQP1 channels not only depends on the size of the solutes but probably also on their flexibility and their ability to form H-bonds. 相似文献
43.
Evaluation of the association of nine Helicobacter pylori virulence factors with strains involved in low-grade gastric mucosa-associated lymphoid tissue lymphoma 总被引:5,自引:0,他引:5 下载免费PDF全文
Lehours P Ménard A Dupouy S Bergey B Richy F Zerbib F Ruskoné-Fourmestraux A Delchier JC Mégraud F 《Infection and immunity》2004,72(2):880-888
Helicobacter pylori has been associated with the development of two malignant diseases: gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Although the cag pathogenicity island, especially the cagA gene, has been linked with adenocarcinoma, few data concerning H. pylori pathogenic factors involved in low-grade gastric MALT lymphoma are available. The goal of this study was to analyze the prevalence of and correlation between genes coding for seven H. pylori virulence factors (cagA, cagE, vacA, iceA, babA, hopQ, and oipA) and two novel adhesins (sabA and hopZ) by comparing a collection of 43 H. pylori strains isolated from patients with low-grade gastric MALT lymphoma to 39 strains isolated from age-matched patients with gastritis only. Our results show that taken individually, none of the nine genes tested can be considered associated with MALT strains and allow us to conclude that MALT pathogenesis is not linked with more proinflammatory H. pylori strains. We demonstrated that in patients infected with strains harboring the iceA1 allele, sabA functional status, and hopZ "off" status, the odds of developing a MALT lymphoma were 10 times higher. However, the low prevalence of such strains (10 of 43 MALT strains) renders this triple association a low-sensitivity marker for MALT strains. Our data confirmed that H. pylori virulence factors are correlated with one another. If the involvement of H. pylori in MALT lymphoma is well established, the pathomechanism by which gastric lymphoma occurs remains to be identified. 相似文献
44.
Brix S Kjaer TM Barkholt V Frøkiaer H 《International archives of allergy and immunology》2004,135(3):216-220
BACKGROUND: Microbial components in the environment are potent activators of the immune system with capacity to shift the active immune response towards priming of Th1 and/or Th2 cells. Lipopolysaccharide (LPS), a cell-wall component of Gram-negative bacteria, is extensively present in food products like cow's milk. It is not well established, however, how this presence of LPS affects oral tolerance induction. METHODS: We studied the effect of LPS contamination in a commercial preparation of the cow milk protein beta-lactoglobulin (beta-LG) on antigen-specific immune responses. IgG1/IgG2a production upon intraperitoneal immunization without adjuvant was measured, and oral tolerance induction against beta-LG after administration of either an aqueous solution or water-in-oil (w/o) emulsion of beta-LG was evaluated. RESULTS: LPS contamination of beta-LG provoked a beta-LG-specific IgG2a response, as well as an enhanced beta-LG-specific IgG1 response upon intraperitoneal immunization. Oral tolerance induction to beta-LG was induced by aqueous solutions of beta-LG with and without LPS administration. Conversely, oral administration of w/o-emulsified beta-LG prevented oral tolerance to beta-LG only when the beta-LG was contaminated with LPS. CONCLUSIONS: LPS contamination of an aqueous protein solution does not affect oral tolerance induction, whereas LPS present in emulsion prevents oral tolerance induction towards the food protein. 相似文献
45.
Detection of circulating Aspergillus fumigatus galactomannan: value and limits of the Platelia test for diagnosing invasive aspergillosis 总被引:8,自引:0,他引:8
Pinel C Fricker-Hidalgo H Lebeau B Garban F Hamidfar R Ambroise-Thomas P Grillot R 《Journal of clinical microbiology》2003,41(5):2184-2186
The effectiveness of galactomannan detection with the Platelia test was evaluated in a prospective study of 3,327 sera from 807 patients. The specificity was 99.6% (748 of 751 cases). For the groups of patients with proven and probable invasive aspergillosis, the sensitivity was 50.0% (17 of 34 cases). The disappointing sensitivity associated with the presence of rare false-positive cases underlines the limits of this test. 相似文献
46.
47.
S. Coppola R. Caroppo E. Frömter 《Pflügers Archiv : European journal of physiology》1994,429(2):203-209
Following the technical approach described in the preceding publication we have investigated if, and how, stimulation of gastric HCl secretion affects the basolateral ion transport properties of oxyntopeptic cells of Rana catesbeiana stomach. To this end microdissected gastric glands were punctured with conventional or H+-sensitive glass microelectrodes and the effects of changing bath ion concentrations on the cell membrane potential (V
b) and cell pH (pHi) were determined. Except for a transient alkalinization, histamine (0.5 mmol/l) did not significantly affect V
b or pHi. The latter averaged 7.18±0.03 (mean±SEM, n=5) under resting conditions (0.1 mmol/l cimetidine) and 7.21±0.07 (n=5) in the presence of histamine. In addition, neither the initial velocity nor the final steady-state value of the cell alkalinization following a 101 reduction of bath Cl– concentration changed in the presence of histamine, and the same holds true for the cell acidification following a 101 reduction of bath HCO3
– concentration. These observations indicate that the basolateral Cl–/HCO3
– exchanger was not stimulated by histamine, and that no other base transporters were activated. By contrast, the V
b response to elevation of bath K
+ concentration decreased, and so did the initial depolarizing V
b response to bath Cl– substitution, while the secondary hyperpolarizing response increased. The latter observations are compatible with the notion that stimulation by histamine reduced a pH-insensitive part of the basolateral K+ conductance and reduced also the basolateral Cl– conductance. 相似文献
48.
Hubacek JA Stüber F Fröhlich D Book M Wetegrove S Rothe G Schmitz G 《Genes and immunity》2000,1(6):405-407
Sepsis is characterised by a systemic inflammatory response to bacterial products during infection, which interestingly both in humans and animal models is gender associated with a higher susceptibility of males than females. The CD14 receptor is involved in activation of cells by lipopolysaccharides released from Gram-negative bacteria and, as recently shown, also by products of Gram-positive bacteria (e.g., peptidoglycans and lipoteichoic acid). The functional relevance of a C(-159)T CD14 polymorphism recently has been shown based on correlation of the T allele to higher plasma levels of soluble CD14, and higher membrane expression on monocytes. We, therefore, now analysed this CD14 polymorphism in 204 patients with severe sepsis and 247 controls. No significant difference of allele frequencies was observed between sepsis patients and controls neither for males nor females. Mortality also was not associated with the polymorphism studied. This may suggest that other mechanisms for lipopolysaccharide recognition, such as the recently described Toll-like receptors are important for inflammatory cell activation in sepsis. 相似文献
49.
Prevalence and characterization of a binary toxin (actin-specific ADP-ribosyltransferase) from Clostridium difficile 总被引:2,自引:0,他引:2 下载免费PDF全文
Gonçalves C Decré D Barbut F Burghoffer B Petit JC 《Journal of clinical microbiology》2004,42(5):1933-1939
In addition to the two large clostridial cytotoxins (TcdA and TcdB), some strains of Clostridium difficile also produce an actin-specific ADP-ribosyltransferase, called binary toxin CDT. We used a PCR method and Southern blotting for the detection of genes encoding the enzymatic (CDTa) and binding (CDTb) components of the binary toxin in 369 strains isolated from patients with suspected C. difficile-associated diarrhea or colitis. Twenty-two strains (a prevalence of 6%) harbored both genes. When binary toxin production was assessed by Western blotting, 19 of the 22 strains reacted with antisera against the iota toxin of C. perfringens (anti-Ia and anti-Ib). Additionally, binary toxin activity, detected by the ADP-ribosyltransferase assay, was present in only 17 of the 22 strains. Subsequently, all 22 binary toxin-positive strains were tested for the production of toxins TcdA and TcdB, toxinotyped, and characterized by serogrouping, PCR ribotyping, arbitrarily primed PCR, and pulsed-field gel electrophoresis. All binary toxin-positive strains also produced TcdB and/or TcdA. However, they had significant changes in the tcdA and tcdB genes and belonged to variant toxinotypes III, IV, V, VII, IX, and XIII. We could differentiate 16 profiles by using typing methods, indicating that most of the binary toxin-positive strains were unrelated. 相似文献
50.
Fimbriae-like filaments were demonstrated on the surface of Bordetella pertussis, serotype 1.3, by negative staining and electronmicroscopy. Immunoelectronmicroscopy with a monoclonal antibody specific for strains possessing agglutinogen 3, and colloidal gold, gave strong labelling of these structures. However, incubation with adsorbed polyclonal anti-agglutinogen 3 serum gave only weak labelling of the distal parts of the filaments and of the bacterial surface. The different binding patterns of the two antisera suggested that the epitopes involved were dissimilar. Thus, agglutinogen 3, as defined by conventional adsorbed sera, appeared to be associated with the fimbriae-like structures but was not necessarily identical to the fimbrial subunit protein. The monoclonal antibody, however was more likely directed against the subunits of the fimbriae-like structures on serotype 1.3 bacteria. 相似文献