全文获取类型
收费全文 | 38889篇 |
免费 | 1856篇 |
国内免费 | 110篇 |
专业分类
耳鼻咽喉 | 930篇 |
儿科学 | 1047篇 |
妇产科学 | 2399篇 |
基础医学 | 5219篇 |
口腔科学 | 1403篇 |
临床医学 | 1881篇 |
内科学 | 7366篇 |
皮肤病学 | 1382篇 |
神经病学 | 3011篇 |
特种医学 | 895篇 |
外国民族医学 | 6篇 |
外科学 | 4990篇 |
综合类 | 215篇 |
一般理论 | 3篇 |
预防医学 | 2815篇 |
眼科学 | 1479篇 |
药学 | 4049篇 |
中国医学 | 126篇 |
肿瘤学 | 1639篇 |
出版年
2022年 | 673篇 |
2021年 | 1055篇 |
2020年 | 565篇 |
2019年 | 918篇 |
2018年 | 1245篇 |
2017年 | 852篇 |
2016年 | 903篇 |
2015年 | 871篇 |
2014年 | 1254篇 |
2013年 | 1730篇 |
2012年 | 2036篇 |
2011年 | 2280篇 |
2010年 | 1347篇 |
2009年 | 1014篇 |
2008年 | 1410篇 |
2007年 | 1586篇 |
2006年 | 1656篇 |
2005年 | 1438篇 |
2004年 | 1489篇 |
2003年 | 1290篇 |
2002年 | 1139篇 |
2001年 | 983篇 |
2000年 | 1000篇 |
1999年 | 799篇 |
1998年 | 257篇 |
1992年 | 410篇 |
1991年 | 353篇 |
1990年 | 375篇 |
1989年 | 428篇 |
1988年 | 488篇 |
1987年 | 468篇 |
1986年 | 461篇 |
1985年 | 450篇 |
1984年 | 426篇 |
1983年 | 324篇 |
1979年 | 567篇 |
1978年 | 360篇 |
1977年 | 291篇 |
1976年 | 279篇 |
1975年 | 376篇 |
1974年 | 526篇 |
1973年 | 527篇 |
1972年 | 439篇 |
1971年 | 415篇 |
1970年 | 393篇 |
1969年 | 419篇 |
1968年 | 355篇 |
1967年 | 274篇 |
1966年 | 301篇 |
1965年 | 183篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
In 1984 and at the beginning of 1985 the authors carried out radioimmunoassays (SORIN-CIS kit) the plasma levels of ACTH in 116 multiple sclerosis patients (m-52, f-64) and in 10 cases this radioimmunoassay was done in the cerebrospinal fluid (m-5, f-5). The control group comprised 90 patients with ischialgia and neuroses. The normal value in the plasma was from 0 to 80.86 pg/ml, and in the fluid it was from 0 to 77.08 pg/ml. In multiple sclerosis patients the plasma ACTH level was from 0 to 286.9 pg/ml, in the cerebrospinal fluid from 0 to 89 pg/ml. The values of ACTH were significantly higher in multiple sclerosis patients, mainly in males. In the fluid the level of ACTH was significantly higher in the studied patients. No significant differences in ACTH levels were found between males and females with multiple sclerosis, and in the control group this level was higher in females. Raised ACTH level was found mainly in multiple sclerosis with lung duration of the disease (10 years) at the time of exacerbations. The authors continue studies on the axis hypothalamus-hypophysis-adrenals, on various hormones, prostaglandins, beta-endorphin, biochemical markers, cAMP, cCMP, arylosulphatase A and B MBC etc. 相似文献
83.
P Moszczyński S S?owiński P Moszczyński 《Gigiena truda i professional'nye zabolevaniia》1991,(3):34-36
Medical examinations were performed among 49 non-smokers, 47 workers who had been smoking for more than 10 years, 19 non-smokers exposed to organic solvents and 41 smoking persons occupationally exposed to organic solvents. Both cigarette smoking and the action of organic solvents. decreased the levels of IgA, AgG, IgM and that of lysozyme. In persons exposed to the actions of both cigarette smoking and benzol and its homologues, more significant decreases of IgA, AgG, IgM and lysozyme concentrations were revealed as compared to those affected by one of the factors. The same concerned the IgD level. The contributors proposed that cigarette smoking should be taken into account when evaluating the immunotoxic properties of industrial factors. 相似文献
84.
85.
Two groups of proteins are present in the vitreous: collagen and non-collagen, deriving probably from the blood serum. The authors examined the proteolytic activity against haemoglobin in the course of some ocular pathological conditions. It was demonstrated that the vitreous digests haemoglobin in the acid division of pH (optimum--3.0-4.5) with various activity dependent on the pathological condition of the eye. 相似文献
86.
I Pokrzywnicka-Gajek A Jedryka-Góral H Chwalińska-Sadowska J Ferdynus-Chromy T Wagner 《Materia medica Polona. Polish journal of medicine and pharmacy》1992,24(1):57-59
Two cases of sarcoidosis located outside the lungs are reported. In both cases the symptoms of the sicca syndrome were in the foreground. In the first case other clinical manifestations included mediastinal and retroperitoneal lymphadenopathy, and lacrimal gland impairment. In the other case the symptoms of the sicca syndrome were associated with polyneuropathy and maculopapular skin rash. The diagnosis of sarcoidosis was confirmed by histological examination of a biopsy specimen of lower lip mucosa in the first case, and biopsy of skin lesion in the second case. Abnormal results of laboratory tests included only raised erythrocyte sedimentation rate, in both cases and presence of circulating immune complexes in one case. Serological tests failed to demonstrate the presence of rheumatoid factor, antinuclear and anti-ds DNA antibodies. No decrease was observed also in the haemolytic activity of the complement, and cryoglobulins were absent. Regression of clinical signs was obtained in both cases after treatment with glucocorticosteroids. 相似文献
87.
Administration of kainic acid (15 mg/kg, i.p.) or pentetrazole (75 mg/kg, i.p.) to rats evoked recurrent limbic or tonic-clonic seizures, respectively. Radioimmunoassay showed that the level of alpha-neoendorphin (prodynorphin-derived peptide) in the hippocampus was decreased after 3 h (by c. 60%) and 72 h (by c. 40%), but was not changed after 24 h following kainic acid administration. The basal release of alpha-neoendorphin from hippocampal slices of kainic acid-treated rats was decreased after 3, 24 and 72 h following the drug injection by c. 50%. The K(+)-stimulated release was decreased after 3 and 24 h (by c. 300 and 200%, respectively) and was back to the control level after 72 h. An in situ hybridization study showed that kainic acid strongly enhanced the prodynorphin messenger RNA levels in the dentate gyrus after 3 and 24 h (by c. 200%), whereas after 72 h it tended to decrease. Twenty four hours after pentetrazole injection the hippocampal level of alpha-neoendorphin was elevated (by c. 33%) and remained unchanged after 3 and 72 h. No significant changes in the basal or K(+)-stimulated alpha-neoendorphin release from hippocampal slices of pentetrazole-treated rats were found at any time points measured. Three and 24 h after pentetrazole administration the level of prodynorphin mRNA in the dentate gyrus was slightly decreased (by c. 30%), but was back to the control values after 72 h. Hence seizure-related changes in hippocampal prodynorphin neuron activity seem to depend on the experimental model of epilepsy.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
88.
The authors present the results of investigations performed in 28 right-handed, normally seeing persons divided into 2 groups: 15 of them were in productive age and 13 in older age. The authors compared the dynamics of the behaviour of the visual functions in dependence on the age of the subjects and the stay in the glow and sodium light. No adverse influence of the sodium light on the hand localization could be detected, instead it seems that it negatively influenced the selective reaction in older productive persons in the sense of an increased number of faults. 相似文献
89.
The spectrometric analysis of extracts from tobacco and tobacco smoke revealed the presence of pentobarbital in the analyzed substances. Tobacco samples and tobacco smoke were extracted with chloroform, determinations were performed with the Perkin-Elmer Autosystem XL system, on a Turbo Mass spectrometer. Subject to analysis were 4 cigarette brands manufactured in Poland and raw, unprocessed tobacco. The presence of pentobarbital in the analyzed samples was confirmed by the analysis of the mass spectrum of the substance, as well as by comparison of retention time with standard of pentobarbital. The determined pentobarbital concentrations in tobacco amounted to 3-6 microg/cigarette, and in tobacco smoke they were approximately 45% lower. In case of tobacco extracts it can with high probability be excluded that pentobarbital is synthesized during chromatographical analysis. The presence of pentobarbital in tobacco is thus beyond question. 相似文献
90.
The aim of this study was to evaluate the influence of female sex hormones on phenazone pharmacokinetics using as an experimental model female rabbits after a bilateral ovariectomy. Eighteen female rabbits divided into two groups: control animals and experimental rabbits, that underwent ovariectomy, were used in the study. Pharmacokinetic assays were performed in all animals: prior to the study, after 1 month and after 2 months. Blood was sampled within 24 hours after intragastric administration of phenazone at a dose 50 mg/kg b.w. Two compartment open model was used for calculations. Significant increase in AUC and prolongation of phenazone halflife as well as a decrease in the total body clearance were noted. The study demonstrated the possible inhibition of the microsomal mixed-function oxidase system by oestrogens. 相似文献