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971.
Cressey TR Jourdain G Lallemant MJ Kunkeaw S Jackson JB Musoke P Capparelli E Mirochnick M 《Journal of acquired immune deficiency syndromes (1999)》2005,38(3):283-288
OBJECTIVE: To determine nevirapine (NVP) plasma levels during the postpartum period after a single intrapartum NVP dose for the prevention of mother-to-child transmission. METHODS: Plasma samples at delivery and during days 8 to 45 postpartum were obtained from HIV-infected Thai women who received an intrapartum NVP dose in the Perinatal HIV Prevention Clinical Trial-2 (PHPT-2) for the prevention of perinatal HIV transmission. These data were combined with NVP concentration data from 2 phase 1 studies of NVP for a population analysis. RESULTS: The median NVP level fell to 68 ng/mL (range: <50-228, n = 43) 8 to 14 days after dosing and to 51 ng/mL (range: <50-166, n = 25) between 15 and 21 days. During the second and third weeks postpartum, NVP levels were below the limit of quantitation in 23% and 44% of samples, respectively. Between 21 and 45 days, no sample had a quantifiable NVP concentration. A simulation derived from the population analysis predicts that NVP concentration falls to less than 10 ng/mL in 5% of women by 11 days, in 50% of women by 17.5 days, and in 95% of women by 28 days. CONCLUSIONS: Significant NVP concentrations remained for up to 20 days in these Thai women. To ensure that coverage is maintained until NVP concentrations fall to nonsuppressive levels, 1 month of additional antiretroviral treatment after delivery should be considered to prevent the emergence of resistant viruses. 相似文献
972.
973.
Jaan Noolandi Mark C. Peterman Philip Huie Christina Lee Mark S. Blumenkranz Harvey A. Fishman 《Biomedical microdevices》2003,5(3):195-199
Electronic chips that provide a patterned stimulus to cells in the retina may provide a viable treatment for age-related macular degeneration. A surrogate MEMS device, in the form of a print-head from a desktop printer, has been used to eject a pattern of neurotransmitters (bradykinin) onto living rat pheochromocytoma (PC12) cells. Fluorescent calcium imaging was used to measure the patterned stimulation of individual cells. The chemical stimulation of cells by directed microfluidic delivery may have applications in retinal prosthetic devices, and in other prosthetic implants in the nervous system. 相似文献
974.
975.
Expression of activation markers on alveolar macrophages in allergic asthmatics after endobronchial or whole-lung allergen challenge 总被引:4,自引:0,他引:4
Viksman MY Bochner BS Peebles RS Schleimer RP Liu MC 《Clinical immunology (Orlando, Fla.)》2002,104(1):77-85
We examined the effect of endobronchial (EB) or whole-lung (WL) challenge with ragweed or Timothy grass extract on alveolar macrophage (AM) activation. Expression of 17 constitutive activation markers on AM was examined by flow cytometry. Late-phase bronchial obstruction was greater after WL challenge, while changes in bronchoalveolar lavage cytology (eosinophil accumulation) were greater after EB challenge. After EB challenge, levels of 10 of 17 markers (CD11a, CD11b, CD14, CD18, CD23, CD32, CD63, CD64, HLA-class I, and HLA-DR) were significantly increased (by 33-234%, P < 0.05). Six markers (CD16, CD29, CD33, CD35, CD44, CD71, and HLA-DQ) remained unchanged. Levels of seven markers following EB challenge (CD14, CD16, CD18, CD29, CD32, HLA-class I, and HLA DQ) correlated with airway sensitivity to methacholine. WL challenge only increased expression of HLA-class I. The different results obtained with the two challenge methods probably depend on higher local concentrations of allergen in the EB challenge. We suggest that activation of AM occurs following EB challenge with antigen in asthmatics. 相似文献
976.
Cloning and Characterization of the Rat Gene Encoding GAP-43 总被引:1,自引:0,他引:1
Grabczyk E Zuber MX Federoff HJ Ng SC Pack A Fishman MC 《The European journal of neuroscience》1990,2(10):822-827
977.
Jose W. Rodriguez Ward G. Kirlin Ronald J. Ferguson Mark A. Doll Kevin Gray Timothy D. Rustan Mark E. Lee Katherine Kemp Paul Urso David W. Hein 《Archives of toxicology》1993,67(7):445-452
Polymorphic expression of arylamine N-acetyltransferase (EC 2.3.1.5) may be a differential risk factor in metabolic activation of arylamine carcinogens and susceptibility to cancers related to arylamine exposures. Human epidemiological studies suggest that rapid acetylator phenotype may be associated with higher incidences of colorectal cancer. We used restriction fragment length polymorphism analysis to determine acetylator genotypes of 44 subjects with colorectal cancer and 28 non-cancer subjects of similar ethnic background (i.e., approximately 25% Black and 75% White). The polymorphic N-acetyltransferase gene (NAT2) was amplified by the polymerase chain reaction from DNA templates derived from human colons of colorectal and non-cancer subjects. No significant differences inNAT2 allelic frequencies (i.e., WT, M1, M2, M3 alleles) or in acetylator genotypes were found between the colorectal cancer and non-cancer groups. No significant differences inNAT2 allelic frequencies were observed between Whites and Blacks or between males and females. Cytosolic preparations from the human colons were tested for expression of arylamine N-acetyltransferase activity. Although N-acetyltransferase activity was expressed for each of the arylamines tested (i.e., p-aminobenzoic acid, 4-aminobiphenyl, 2-aminofluorene, -naphthylamine), no correlation was observed between acetylator genotype and expression of human colon arylamine N-acetyltransferase activity. Similarly, no correlation was observed between subject age and expression of human colon arylamine N-acetyltransferase activity. These results suggest that arylamine N-acetyltransferase activity expressed in human colon is catalyzed predominantly by NAT1, an arylamine N-acetyltransferase that is not regulated byNAT2 acetylator genotype. The ability to determine acetylator genotype from DNA derived from human surgical samples should facilitate further epidemiological studies to assess the role of acetylator genotype in various cancers. 相似文献
978.
The purpose of the present study was to examine the acute and chronic effects of (±)3,4-methylenedioxymethamphetamine (MDMA) in pigeons responding under a delayed-matching-to-sample procedure with 0-, 3-, and 6-s delays. In the absence of drug, accuracy (percent correct responses) was inversely related to delay length. When administered pre-chronically, MDMA (0.32–5.6 mg/kg) generally decreased accuracy and response rates at doses of 3.2 mg/kg and above. Although humans report a distinct hangover when exposure to MDMA ends, performance of pigeons in the present study did not deteriorate when the chronic regimen ended, indicating an absence of behavioral dependence on the drug. Tolerance developed following chronic exposure to 3.2 mg/kg. In general, greater tolerance occurred at the 0-s delay than at longer delays. Although MDMA is reported to have neurotoxic effects, it does not inevitably produce long-lasting or cumulative behavioral impairment.The reported data were collected as part of the M.A. thesis of the first author. The study was supported by a grant from the Western Michigan University Graduate Student Research Fund. 相似文献
979.
Peter J. O'Dwyer Mark J. Cornfeld Ruth Peter Robert L. Comis 《Cancer chemotherapy and pharmacology》1990,27(2):131-134
Summary The ongoing evaluation of combination chemotherapy with 5-fluorouracil (5-FU) and cisplatin in several tumors prompted a phase I clinical trial of cisplatin with 5-FU modulated by leucovorin. A total of 26 patients were treated with varying doses of 5-FU by continuous i.v. infusion for 5 days; 200 mg/m2 leucovorin was given by daily bolus injection for 5 days; and 20 mg/m2 cisplatin was infused over 2 h on each day of treatment. Courses were repeated every 21–28 days. The starting dose of 5-FU was 300 mg/m2. Poor-risk patients (extensive prior radiation, performance status of 2 or worse) did not tolerate the initial dose; the maximum tolerated dose of 5-FU in this group was 200 mg/m2 daily. Good-risk patients tolerated 300 mg/m2, but a majority had excessive toxicity at higher doses. The dose-limiting toxicity was gastrointestinal (mucositis/diarrhea) and/or myelosuppression; additional side effects included were nausea and vomiting (grade 2) and ataxia (one patient). Among 13 patients with colorectal cancer, 4 partial responses were observed. The marked reduction in the tolerable dose of 5-FU occasioned by the addition of modulating doses of leucovorin is noteworthy. The response observed support further investigation of this regimen in phase II trials. 相似文献
980.
Abigail Paterson Mark A. Elliott Louise A. Brown Nicholls Susan Rasmussen 《British journal of health psychology》2023,28(4):1241-1260