全文获取类型
收费全文 | 3378篇 |
免费 | 175篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 79篇 |
妇产科学 | 55篇 |
基础医学 | 519篇 |
口腔科学 | 91篇 |
临床医学 | 317篇 |
内科学 | 582篇 |
皮肤病学 | 53篇 |
神经病学 | 416篇 |
特种医学 | 81篇 |
外科学 | 402篇 |
综合类 | 14篇 |
预防医学 | 291篇 |
眼科学 | 25篇 |
药学 | 401篇 |
中国医学 | 2篇 |
肿瘤学 | 202篇 |
出版年
2022年 | 30篇 |
2021年 | 49篇 |
2020年 | 27篇 |
2019年 | 30篇 |
2018年 | 58篇 |
2017年 | 36篇 |
2016年 | 46篇 |
2015年 | 50篇 |
2014年 | 73篇 |
2013年 | 117篇 |
2012年 | 154篇 |
2011年 | 179篇 |
2010年 | 89篇 |
2009年 | 93篇 |
2008年 | 161篇 |
2007年 | 177篇 |
2006年 | 167篇 |
2005年 | 186篇 |
2004年 | 162篇 |
2003年 | 156篇 |
2002年 | 169篇 |
2001年 | 40篇 |
2000年 | 35篇 |
1999年 | 37篇 |
1998年 | 67篇 |
1997年 | 63篇 |
1996年 | 46篇 |
1995年 | 48篇 |
1994年 | 44篇 |
1993年 | 47篇 |
1992年 | 54篇 |
1991年 | 48篇 |
1990年 | 45篇 |
1989年 | 34篇 |
1988年 | 39篇 |
1987年 | 36篇 |
1986年 | 51篇 |
1985年 | 60篇 |
1984年 | 58篇 |
1983年 | 35篇 |
1982年 | 59篇 |
1981年 | 36篇 |
1980年 | 31篇 |
1979年 | 32篇 |
1978年 | 31篇 |
1977年 | 27篇 |
1975年 | 41篇 |
1974年 | 17篇 |
1973年 | 19篇 |
1967年 | 17篇 |
排序方式: 共有3565条查询结果,搜索用时 15 毫秒
21.
22.
A path analysis of published reports on family resemblance reveals an important role for genetic factors in all lipids and lipoproteins, with no evidence of a discrepancy between twins and other relatives (which might be due to dominance or epistasis) nor between studies which used environmental indices and those which did not. Family environment within population is less important and is significantly greater for twins than for other relatives. 相似文献
23.
24.
Leif Bergdahl Lennart Boquist 《Virchows Archiv : an international journal of pathology》1973,358(3):225-239
Summary A search was made for patients with associated secondary hyperparathyroidism and hypercalcemia: 22 such cases were found in the literature and 22 were recorded among 92 patients operated upon because of parathyroid disease. In the remaining 70 patients the effect of the operation on the serum calcium level was investigated: persisting hypercalcemia after the operation was found in 28 per cent of the cases.The patients reporded in the literature possessed severe renal and skeletary changes and light microscopic evidence of parathyroid adenoma (2 cases), hyperplasia (15 cases), or hyperplasia and adenoma (5 cases).The other 22 patients had histories of long-standing renal disease, most often chronic pyelonephritis, of varying severity. Skeletary roentgenograms were often normal. Morphologic examination of the parathyroids showed adenoma (6 cases) or hyperplasia (16 cases). Postoperatively, normal serum calcium level was found in 9 cases and persisting hypercalcemia in 13 (=59 per cent) cases. One patient possessed also a malignant -cell insuloma and Zollinger-Ellison's syndrome.It is suggested that secondary hyperparathyroidism may develop in patients with only slight or moderate impairment of renal function, that hypercalcemia occurs more often than previously believed in secondary hyperparathyroidism, and that some cases of secondary hyperparathyroidism previously, erroneously have been classified as primary hyperparathyroidism.Supported by grants from the Swedish Medical Research Council (Project No. B72-17X-3499-01), the Swedish Cancer Society (Project No. 552-B71-01P), and the Medical Faculty, University of Umeå. 相似文献
25.
26.
Brodin L Theordorsson E Christenson J Cullheim S Hökfelt T Brown JC Buchan A Panula P Verhofstad AA Goldstein M 《The European journal of neuroscience》1990,2(12):1095-1109
Neurotensin (NT)-like peptides in the CNS of the lamprey Lampetra fluviatilis were studied by radioimmunoassay (C-terminal specific NT antiserum), reverse-phase HPLC and immunohistochemistry. Multiple peaks of NT-immunoreactive (-ir) material were observed upon HPLC, of which a major peak eluted in the position of bovine NT. Immunofluorescence histochemistry showed that a monoclonal antibody recognizing the N-terminal (1 - 11) fragment of NT, as well as two polyclonal NT antisera labelled a large number of cell bodies in the periventricular area of hypothalamus, including the postinfundibular commissural nucleus and the ventral and dorsal hypothalamic nuclei. Additional groups of NT-ir cells were observed in the preoptic nucleus, the postoptic commissural nucleus, the mesencephalic tegmentum (L.fluviatilis), and in the spinal cord (L.fluviatilis and Ichtyomyzon unicuspis). Dense NT-ir fibre plexuses were present in the caudal hypothalamus, corpus striatum, ventral mesencephalon, and in the dorsal horn and lateral margin of the spinal cord. At the ultrastructural level the lateral spinal margin showed NT-ir terminal structures, which in most cases were not associated with synaptic specializations, although occasional synaptic contacts with unlabelled elements were found. The relation between NT-ir and monoamine-containing cells was examined with immunofluorescence double-staining, using antisera to tyrosine hydroxylase (TH), 5-hydroxytryptamine (5-HT), and histamine respectively. In the periventricular nuclei of hypothalamus numerous TH-, 5-HT-, as well as histamine-ir cells were located in close association with NT-ir cells, but none of the aminergic markers could be detected within NT-ir neurons. The chemical properties as well as the anatomical distribution of lamprey NT-like peptides show several similarities with those present in mammals, suggesting that NT-containing neuronal systems in the CNS developed early in vertebrate phylogeny. 相似文献
27.
28.
High exposures to organic solvents among graffiti removers 总被引:3,自引:0,他引:3
Helena Anundi Marie-Louise Lind Lennart Friis Nadja Itkes Sven Langworth Christer Edling 《International archives of occupational and environmental health》1993,65(4):247-251
Summary The exposure to organic solvents among 12 graffiti removers was studied. Health effects were also assessed by structured interview and a symptom questionnaire. Blood and urine samples were collected at the end of the day of air sampling. The concentrations of dichloromethane, glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone in the breathing zone of each worker were measured during one working day. The 8-h time-weighted average exposure to dichloromethane ranged from 18 to 1200 mg/m3. The Swedish Permissible Exposure Limit value for dichloromethane is 120 mg/m3. The air concentrations of glycol ethers, trimethylbenzens and N-methyl-2-pyrrolidinone were low or not detectable. No exposure-related deviations in the serum concentrations of creatinine, aspartate transaminase, alanine transaminase, -glutamyl transpeptidase or hyaluronan or the urine concentrations of 1-microglobulin, R2-microglobulin or N-acetyl--glucos-aminidase were found. Irritative symptoms of the eyes and upper respiratory tract were more prevalent than in the general population. This study demonstrates that old knowledge about work harzards is not automatically transferred to new professions. Another aspect is that the public is also exposed as the job is performed during daytime in underground stations. At least for short periods, bystanders may be exposed to high concentrations of organic solvent vapours. People with predisposing conditions, e.g. asthmatics, may risk adverse reactions. 相似文献
29.
We reviewed the clinical safety of tiagabine HCl (TGB), a selective CNS GABA uptake inhibitor, in nearly 3100 patients from 53 separate clinical trials. TGB was found to have no clinically important effect upon hepatic metabolic processes, serum concentrations of concomitant antiepileptic drugs (AEDs), laboratory values, or important interactions with any common non-AEDs. Adverse effects were usually mild and involved the nervous system. TGB is safe and well-tolerated as add-on therapy for the treatment of partial seizures. 相似文献
30.
Steady-state kinetics of imipramine in patients 总被引:1,自引:0,他引:1
Lars F. Gram Ib Søndergaard Johannes Christiansen Gorm Odden Petersen Per Bech Niels Reisby Ilse Ibsen Jørgen Ortmann Adam Nagy Sven J. Dencker Ove Jacobsen Ole Krautwald 《Psychopharmacology》1977,54(3):255-261
Steady-state plasma level kinetics were studied in 76 patients given imipramine (IP) 150 to 225 mg/day for 2–5 weeks. IP was given in three divided doses at 8.00 a.m., 1.00 p.m. and 5.00 p.m. Plasma concentrations of IP and its active metabolite desipramine (DMI) were determined by quantitative in situ thin-layer chromatography. The plasma levels of IP and DMI showed pronounced flucutations throughout the day with a ratio of about 2 between highest and lowest level. Patients with steady-state levels of IP and/or DMI below 50 g/l reached this within 1 week of treatment. Patients with higher steady-state levels reached steady-state concentrations within 2–3 weeks. There were some intraindividual fluctuations in plasma levels from week to week after steady state had been reached (coefficient of variation: 10–20%). Interindividually, the steady-state levels corrected to a dose of 3.5 mg/kg per day varied considerably: IP: 6–356 g/l, DMI: 24–659 g/l and IP+DMI: 58–809 g/l. The steady-state plasma levels showed a skew distribution that became normal by logarithmic transformation. The IP/DMI ratio ranged from 0.07 to 5.5 with a median value of 0.47. Compared to data from amitriptyline treated patients the IP/DMI ratios had significantly lower median value and larger variation than the corresponding plasma level ratios of amitriptyline/nortriptyline. Several statistically significant differences in steady-state levels between age groups were found. For IP: Women aged 30–39 had lower levels than women aged 20–29, 40–49, and 50–59, and men aged 50–59 and 60–65; men aged 30–39 had lower levels than men aged 60–65. For DMI: Women aged 30–39 had lower levels than women aged 50–59. 相似文献