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排序方式: 共有1075条查询结果,搜索用时 31 毫秒
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Twenty-six patients with perennial rhinorrhea were treated by Atrovent, the anticholinergic agent, or placebo in a randomized double-blind crossover trial. The severity and duration of rhinorrhea were significantly reduced by Atrovent. Local side effects were more frequent with the active drug. These were reduced in a later open trial by a reduction in dosage. 相似文献
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Dusinská M Kazimírová A Barancoková M Beno M Smolková B Horská A Raslová K Wsólová L Collins AR 《Mutagenesis》2003,18(4):371-376
In order to investigate the effects of antioxidant supplementation on chromosome damage, a 3 month antioxidant supplementation trial was conducted on groups of 28 myocardial infarction survivors and 57 rural controls, all male. The supplement consisted of vitamin C (100 mg/day), vitamin E (100 mg/day), beta-carotene (6 mg/day) and selenium (50 microg/day). Dietary antioxidants in plasma were measured, as well as the ferric reducing ability of plasma (a measure of total plasma antioxidant status) and the concentration of malondialdehyde as an indicator of oxidative stress. Lymphocytes collected at the beginning and end of the supplementation period were stimulated to proliferate and metaphases accumulated for scoring of chromosome aberrations: per cent aberrant cells and chromatid and chromosome breaks. Supplementation with antioxidants was associated with a decrease in the percentage of cells with chromosome aberrations in the group of rural controls (0.63% before compared with 0.27% after supplementation; P = 0.03). The largest effect of supplementation was seen in smokers in this group (0.12% aberrant cells in supplemented compared with 0.81% in placebo group; P > 0.001). The results support the hypothesis that antioxidants decrease genetic damage. 相似文献
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These studies were undertaken to analyse the genetic control of the immune response to an oligomeric protein and the role of individual subunits in the regulation of the response. Human adult haemoglobin (Hb) was selected as a model for these studies because it is a well-characterized protein and its antigenic structure is being determined in our laboratories. Mice of various congenic strains were immunized with Hb and the lymph node cells from Hb-primed mice were challenged in vitro with Hb, and its alpha-chain and beta-chains as well as an appropriate control antigen. Lymphocyte proliferation was determined by 3H-thymidine incorporation. The data collected indicated that mice of the H-2b and H-2d haplotypes were high responders while H-2k, H-2s, H-2q and H-2j haplotype mice were low responders to Hb. Studies with H-2 recombinant strains indicated that the immune response to Hb and its subunits is determined by genes in the I-A subregion and the D end of the H-2 complex. The significance of these findings in terms of control and regulation of the overall response to native Hb are discussed. 相似文献
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Mustafa Cengiz Cem Onal Ferah Yildiz A Faruk Zorlu 《Radiotherapy and oncology》2004,73(1):109; author reply 109-109; author reply 110
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K Cagdas Kazikdas Bulent Serbetcioglu Ismail Boyraz Kazim Tugyan Guven Erbil Osman Yilmaz Kazim Onal 《Otology & neurotology》2006,27(3):303-307
HYPOTHESIS: The goal of this experimental study was to investigate the specific effect of myringosclerosis on tympanograms in the tympanic membranes of myringotomized rats by using otomicroscopy, tympanometry, and histopathology. BACKGROUND: Myringosclerosis is a common sequela of ventilation tube treatment of otitis media with effusion. The condition involves the hyalinization and calcification of the collagen layer in certain areas of the tympanic membrane. Previous animal experiments suggest an intimate relationship between the formation of myringosclerosis and an increased oxygen concentration in the environment of the wound after myringotomy. The result of a myringotomy therefore is an increased production of free oxygen radicals, initiating irreversible tissue damage involving fibrosis, hyalin degeneration, and finally apoptosis as observed in myringosclerosis. We propose an experimental model specific for creating sclerotic plaques solely on the tympanic membrane and for performing tympanometric measurements on this pure myringosclerosis model without creating any abnormality in the middle ear to test in what proportion myringosclerosis contributes to decrease of amplitude in tympanograms. METHODS: To assess the normal tympanometric values of Wistar albino rats, the pressure and peak admittance of the left middle ears were measured using a semiquantitative computerized clinical admittance meter using a sound frequency of 226 Hz. Twelve animals were randomly selected for the myringotomy group and perforations in the left ears were created. All tympanic membrane perforations in this group had healed and closed prior to the otomicroscopic examination and no pathologic reaction was observed in the external ear canals of rats. Otomicroscopic and tympanometric measurements were carried out on Day 15 and the degree of myringosclerosis was noted before the animals were killed. Twelve specimens in the myringotomy group were histopathologically examined for the presence of myringosclerotic plaques. RESULTS: Under light microscopy, extensive sclerotic lesions were found in the tympanic membranes of the myringotomy group, and these sclerotic deposits were located in the lamina propria. The myringosclerosis occurred predominantly adjacent to the handle of the malleus, but also near the annular region. In all ears with myringosclerosis, the magnitude of the maximum admittance reduced to approximately 50% of the Day-0 values, and this reduction was statistically significant (Z=-3.061, p=0.002). CONCLUSION: The present findings in this study are consistent with the fact that the movement of the tympanic membrane is hampered by lesions of sclerotic material, resulting in a decrease of amplitude in tympanograms (such as Type As) without any effusion or inflammation in the middle ear. 相似文献
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<正>Neurodegeneration is one of the biggest public health problems in modern society.Age-associated neurodegeneration,which is accelerated several-fold in Alzheimer’s disease(AD)alone,is not only an enormous social and economic burden to the affected individuals and their families,but is also a great scientific challenge. 相似文献
20.
Alison E. Brown Ellen Heinsbroek Meaghan M. Kall Hester Allen Kazim Beebeejaun Paula Blomquist Ines Campos-Matos Colin N.J. Campbell Hamish Mohammed Katy Sinka Theresa Lamagni Nicholas Phin the PHE COVID- Mortality Working Group Gavin Dabrera 《Emerging infectious diseases》2021,27(5):1468
Of the 58,186 coronavirus deaths among adults in England during March–December 2020, 77% occurred in hospitals, 93% were in patients >60 years, and 91% occurred within 28 days of positive specimen. Cumulative mortality rates were highest among persons of Black, Asian, other, or mixed ethnicities and in socioeconomically deprived areas. 相似文献