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971.
M Wood J Uetrecht J M Phythyon S Shay B J Sweetman O Shaheen A J Wood 《Anesthesia and analgesia》1986,65(5):481-488
Because the H2-receptor antagonist cimetidine has been shown to inhibit drug metabolism, the effects of cimetidine on anesthetic metabolism and toxicity were investigated in a rat model. Cimetidine decreased inorganic plasma fluoride production after methoxyflurane administration both in 21% oxygen (P less than 0.001) and in 100% oxygen (P less than 0.001). Phenobarbital produces an increased fluoride formation after methoxyflurane anesthesia, and this fluoride formation is also reduced by cimetidine (P less than 0.005). There was no significant difference between the plasma fluoride levels in rats anesthetized with halothane or enflurane. Although cimetidine inhibited the in vivo defluorination of methoxyflurane, fluoride levels were still within the nephrotoxic range, and cimetidine is not likely to play a role as part of a preanesthetic regimen that would permit the increased clinical use of methoxyflurane. Cimetidine also inhibited the oxidative metabolism of halothane; cimetidine decreased (P less than 0.05) trifluoroacetic acid concentrations after halothane anesthesia in 21% oxygen and in 100% oxygen and decreased (P less than 0.05) bromide concentrations after halothane anesthesia in 100% oxygen. Trifluoroacetic acid levels were less (P less than 0.02) after halothane anesthesia in 14% oxygen as compared with 100% oxygen, indicating a reduction in oxidative metabolism under hypoxic conditions. However, bromide concentrations were maximal after halothane anesthesia in 21% oxygen, and significantly (P less than 0.001) less after halothane anesthesia in 14% and 100% oxygen. Bromide production, therefore, seems to be inhibited by both hypoxia and hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
972.
Twenty-two patients with recurring attacks of tinnitus, hearing loss and dizziness were treated with transtympanally injected lidocaine. The tinnitus improved in 19, and the pure tone and speech audiometric thresholds decreased in 15 cases. The dizziness and latent spontaneous nystagmus disappeared in all subjects where these symptoms were manifest before treatment. 相似文献
973.
Vecuronium was used as the only neuromuscular blocking agentin 81 paediatric patients (neonates to adolescents) during fentanyland nitrous oxide anaesthesia. The thenar electromyogram wasused to monitor neuromuscular blockade. Neonates and infantshad a mean requirement of vecuronium 105 µg kg1during the first 1 h of anaesthesia, to establish and maintain9098% neuromuscular blockade, compared with a mean requirementof 217 µg kg1 for children aged 310 yr (P< 0.05). Vecuronium 100 and 150 µg kg1 maintainedneuromuscular blockade > 90% for 59 and 110 min, respectively,in neonates and infants, but only for 18 and 38 min in childrenand for 37 and 68 min in adolescents (P < 0.05). Vecuroniummay be regarded as a long-acting neuromuscular blocking agentin patients aged less than 1 yr.
Present address: Department of Anaesthesia, Royal Children'sHospital, Flemington Road, Parkville, Victoria 3052, Australia. 相似文献
974.
975.
976.
977.
Evaluation of anti-C1q capture assay for detecting circulating immune complexes and comparison with polyethylene glycol-immunoglobulin G, C1q-binding, and Raji cell methods. 下载免费PDF全文
An anti-C1q capture method kit (C1q-immunoglobulin G [IgG]) (Ortho Diagnostics, Inc., Raritan, N.J.) for measuring circulating immune complexes (CIC) was evaluated. The kit showed poor diagnostic sensitivity (P less than 0.005) for identifying CIC in patients with systemic lupus, rheumatoid arthritis, and bacterial endocarditis, as compared with polyethylene glycol-IgG and Raji cell tests (12, 24, and 24 positive, respectively, of 31 patients). Of the patients who were positive with the C1q-IgG test, 25% showed discrepancies when their results were compared with the polyethylene glycol-IgG and C1q-binding test results. Gel filtration chromatography of two of these discrepant sera showed the only peak of C1q-IgG activity to be associated with monomeric IgG (molecular weight, less than 200,000). We concluded that the kit method may be measuring substances other than CIC in some sera, because molecules of C1q attached to IgG should exhibit a molecular weight of greater than 500,000. 相似文献
978.
R Malmi K O S?derstr?m 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》1991,99(3):233-243
Histological tissue sections of human testicular embryonal carcinoma from 13 patients and of a xenograft tumour in nude mice, as well as cell lines of human embryonal carcinoma, were investigated with eight different lectins to characterize the distribution of glycoconjugates in embryonal carcinoma. In all cases the malignant cells showed binding with Con A, WGA and RCA I conjugates, whereas other lectins were bound to some, but never to all, tumour cells in each group, revealing the heterogeneity of the malignant cells. A polarization of cancer cells was shown particularly with WGA and RCA I labelling, which was most intense on the luminal borders of the carcinoma cells, where pseudotubular structures were formed. The sugar staining properties were retained in cell culture and in the xenograft tumour. Regardless of the germ cell origin, embryonal carcinoma cells differed from normal germ cells. The distribution of glycoconjugates was also different from that of testicular carcinoma-in-situ germ cells, which share morphological features and the pattern of glycosylation with seminoma cells. However, the similarities in lectin binding pattern of seminomas and embryonal carcinomas suggest the close relationship between the two types of testicular malignancy, without excluding the possibility that embryonal carcinomas were derived from seminomas. Although lectins seem to be less important for differential diagnostic use in testicular cancer, our findings showed the usefulness of lectin histochemistry for characterization of embryonal carcinoma. 相似文献
979.
980.
Using conventional two electrode voltage clamp techniques we have studied the effects of Pb2+, triethyl lead (TEL) and Hg2+ on voltage-activated calcium channels of Aplysia neurons and found that all three metals are potent inhibitors at micromolar concentrations. However, the time course of current reduction or block and its reversibility vary when comparing Pb2+ to TEL and Hg2+. With application of Pb2+ the calcium current decreases immediately and a steady state is reached within three to seven minutes, depending upon the concentration of Pb2+ (IC50 = 61 microM). The block was easily reversed upon wash out of Pb2+ with a time course similar to that of onset. Perfusion with either TEL (5 to 50 microM) or Hg2+ (5 to 200 microM) resulted only in a small reduction of current when the substances reached the cell membrane but with clear reduction within 2 min. The decrease continued at about the same speed for the total duration of the application. Upon washing there was no recovery of the response. At the onset of washing the rate of current decline stopped for several minutes, but then the current continued to decline at a slower rate in the absence of toxicant. Our data suggest that Pb2+ acts by a direct and reversible blockade of the calcium channel. In contrast TEL and Hg2+ act slowly and irreversibly to block calcium channels at concentrations which do not greatly affect membrane potential or resistance. In spite of the slow time course these substances are probably acting directly on the calcium channel. 相似文献