全文获取类型
收费全文 | 11636篇 |
免费 | 571篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 88篇 |
儿科学 | 207篇 |
妇产科学 | 134篇 |
基础医学 | 1412篇 |
口腔科学 | 344篇 |
临床医学 | 744篇 |
内科学 | 3100篇 |
皮肤病学 | 169篇 |
神经病学 | 713篇 |
特种医学 | 309篇 |
外科学 | 2015篇 |
综合类 | 45篇 |
预防医学 | 322篇 |
眼科学 | 315篇 |
药学 | 898篇 |
中国医学 | 36篇 |
肿瘤学 | 1416篇 |
出版年
2023年 | 55篇 |
2022年 | 112篇 |
2021年 | 194篇 |
2020年 | 99篇 |
2019年 | 143篇 |
2018年 | 221篇 |
2017年 | 156篇 |
2016年 | 228篇 |
2015年 | 238篇 |
2014年 | 269篇 |
2013年 | 388篇 |
2012年 | 610篇 |
2011年 | 614篇 |
2010年 | 349篇 |
2009年 | 312篇 |
2008年 | 559篇 |
2007年 | 625篇 |
2006年 | 600篇 |
2005年 | 617篇 |
2004年 | 611篇 |
2003年 | 602篇 |
2002年 | 618篇 |
2001年 | 446篇 |
2000年 | 422篇 |
1999年 | 373篇 |
1998年 | 167篇 |
1997年 | 135篇 |
1996年 | 106篇 |
1995年 | 90篇 |
1994年 | 98篇 |
1993年 | 93篇 |
1992年 | 230篇 |
1991年 | 198篇 |
1990年 | 174篇 |
1989年 | 182篇 |
1988年 | 153篇 |
1987年 | 161篇 |
1986年 | 130篇 |
1985年 | 138篇 |
1984年 | 93篇 |
1983年 | 77篇 |
1982年 | 39篇 |
1980年 | 37篇 |
1979年 | 61篇 |
1978年 | 37篇 |
1977年 | 34篇 |
1974年 | 35篇 |
1972年 | 40篇 |
1971年 | 46篇 |
1969年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
23.
24.
H Shiozaki T Ide J Nakao T Imamura M Nakamura K Shimada Y Miura T Suda 《Japanese journal of cancer research》1992,83(5):499-504
LD78 is a cDNA newly isolated from human stimulated tonsillar lymphocytes. The expression of LD78 is related to inflammatory responses and its structure has a homology with macrophage inflammatory protein 1-alpha, which is known to have an inhibitory effect on murine CFU-S. Using a colony assay technique, we examined the effects of LD78 on human hemopoietic progenitors. The addition of doses of 100 ng/ml or more of LD78 suppressed the colony formation of KMT-2, a factor-dependent myelomonocytic cell line established from cord blood cells; this suppressive activity was neutralized by the addition of antibody against LD78. The same doses of LD78 suppressed the formation of neutrophil, macrophage, and megakaryocytic colonies which were supported by human interleukin-3 and erythropoietin; however, LD78 did not affect colony formation by either non-phagocytic mononuclear cells or sorted CD34+ cells. The conditioned medium of KMT-2 cells or peripheral blood mononuclear cells cultured with LD78 suppressed colony formation by CD34+ cells. From these findings, it is suggested that LD78 affects phagocytic cells and induces factors that are inhibitory for hemopoiesis. We consider LD78 to be a new cytokine that plays an inhibitory role in hemopoiesis. 相似文献
25.
Takuo Fujita Masaaki Fukase Takao Shimada Hironosuke Yamamoto 《Journal of bone and mineral metabolism》1992,10(1):37-40
In addition to estrogen widely used all over the world for the prevention of postmenopausal osteoporosis, calcitonin and vitamin
D derivatives are commonly employed to treat established osteoporosis at higher age in Japan. In order to critically assess
the usefulness of vitamin D derivatives and calcitonin alone or in combination on the advancement of vertebral deformity at
higher age, 32 osteoporotic patients with vertebral deformity with the mean age of 79 were randomly divided into 4 groups
with indistinguishable age and severity of the vertebral deformity. Group 1 served as the control without specific medications
for osteoporosis. Group 2 was treated with 10 units elcatonin (eel calcitonin derivative) injected intramuscularly twice a
week. Group 3 was given 0.75 to 1.5μg/day 1α (OH) vitamin D3 orally. Group 4 was given a combination of treatments used in Groups 2 and 3.
In the lateral X-ray film of the spine taken prior to the test and every 6 months thereafter, the shape of the vertebral body
T8 through L4 was monitored by measuring the anterior, central and posterior heights. Decrease of the vertebral height ratio; anterior
or middle height/posterior or adjacent intact posterior height, by more than 20% of the original value or from above to below
0.80 both appeared to be inhibited during administration of 1α (OH) vitamin D3. Such effect seems to be augmented by simultaneous administration of elcatonin. Actual decrease of vertebral height ratio
values and the per cent fall from the original value significantly less in Groups 3 and 4 than in Group 1. Development of
vertebral deformity assessed by the changes of the vertebral height thus appears to decrease during treatment with 1α (OH) vitamin D3 especially together with calcitonin in established osteoporosis. 相似文献
26.
27.
The cerebellar Purkinje cells in the hemizygote of the macular mutant mouse contain numerous abnormal mitochondria which show a marked decrease in cytochrome c oxidase activity. Using histochemical methods we studied the activity of other mitochondrial enzymes, such as NADH diaphorase and succinic dehydrogenase, in the cerebellar cortex of this mutant mouse. Such activities were markedly increased in the Purkinje cells, especially in the soma and stem dendrite, from 10 days after birth in the hemizygote as compared with findings in normal littermates. These results were considered to be due to an increased number of abnormal mitochondria.Supported by the Research Grants nos. 2A-5-03 and 3B-1-04 for Nervous and Mental Disorders from the Ministry of Health and Welfare, and by Grant no. 04670492 of the Ministry of Education of Japanese Government 相似文献
28.
Assessment of skull base involvement of nasopharyngeal carcinoma by bone SPECT using three detectors system] 总被引:2,自引:0,他引:2
N Yui T Togawa F Kinoshita F Shimada Y Akiyama 《Kaku igaku. The Japanese journal of nuclear medicine》1992,29(1):37-47
SPECT of the skull was performed on twelve patients with histologically proven nasopharyngeal carcinoma using newly developed three detectors SPECT system (Toshiba GCA 9300A) mounted with fan-beam collimators, for the purpose of early detection of skull base involvement of the disease. This SPECT system has extremely improved resolution with FWHM of 8 mm in the center, and it provides clear tomographic images of the skull which has anatomically complex structure. SPECT image was taken 3 hours after injection of 740 MBq (20 mCi) of 99mTc-MDP following whole body skeletal survey. In twelve patients with confirmed nasopharyngeal carcinoma, 8 patients showed positive findings on SPECT. Three of SPECT positive patients also showed destructive findings on CT. Other five positive patients did not show destructive findings on CT at their initial examinations, but in three of them CT findings turned to positive later. SPECT was superior to CT in early detection of skull base involvement. We believe that SPECT of the skull is a diagnostic tool for early detection of skull base involvement of nasopharyngeal carcinoma. 相似文献
29.
Hiroko Nishida Mitsuru Murata Koichi Miyaki Kazuyuki Omae Kiyoaki Watanabe Yasuo Ikeda 《Blood coagulation & fibrinolysis》2006,17(3):203-207
We used the Gorog Thrombosis Test to analyze the factors influencing the occlusion time, which represents platelet activation and subsequent occlusive thrombus formation, in 132 healthy Japanese volunteers (116 men, 16 women; mean age, 45.0 +/- 12.0 years). The Gorog Thrombosis Test was designed to evaluate platelet aggregation and thrombolytic activity under a high shear stress condition (175 dynes/cm) in a native blood sample in vitro. The mean +/- SD occlusion time was 154.8 +/- 64.7 s (men, 153.4 +/- 64.2 s and women, 165.4 +/- 56.5 s). The occlusion time was inversely correlated with von Willebrand factor ristocetin cofactor activity (VWF:Rco) (r = -0.242, P = 0.0055) and von Willebrand factor antigen (r = -0.230, P = 0.0080). The mean occlusion time in the group with VWF:Rco of at least 170% (137 s) was significantly shorter than that in the group with VWF:Rco less than 170% (156 s, P < 0.05). Platelet counts, other coagulation markers and smoking showed no significant correlations with occlusion time. Red blood cells (r = -0.177, P = 0.0365), hemoglobin (r = -0.191, P = 0.0245) and hematocrit (r = -0.182, P = 0.0329) also showed inverse correlations with the occlusion time. This report is the first to clearly demonstrate the role of von Willebrand factor in the formation of occlusive thrombi in the Gorog Thrombosis Test. 相似文献
30.
A. K. Mukhopadhyay S. Garg G. B. Nair S. Kar R. K. Ghosh S. Pajni A. Ghosh T. Shimada T. Takeda Y. Takeda 《Epidemiology and infection》1995,115(3):427-434
Sixty-nine strains of Vibrio cholerae O1 isolated at different times were analysed to investigate if there were any differences among the O1 strains isolated before, during and after the advent of the O139 serogroup. Of the 69 O1 strains examined, 68 belonged to the Ogawa serotype while one belonged to the Inaba serotype. With the exception of one strain all other strains of V. cholerae O1 belonged to the eltor biotype. A single O1 strain isolated before the emergence of the O139 serogroup could not be classified as either eltor or classical biotype because it was resistant to both classical and eltor specific bacteriophages. Marked variations in the susceptibility to antibiotics of V. cholerae O1 isolated during the different periods were observed. In addition, strains of V. cholerae isolated after the epidemic of serogroup O139 in Calcutta showed an expanding R-type with resistance to a variety of drugs as compared to the O1 strains isolated before the advent of the O139 serogroup. From this study, it is clear that there is a substantial mobility in genetic elements of V. cholerae O1 which necessitates a continuous monitoring to keep abreast of the changing traits of the etiologic agent of cholera. 相似文献