全文获取类型
收费全文 | 20329篇 |
免费 | 944篇 |
国内免费 | 149篇 |
专业分类
耳鼻咽喉 | 205篇 |
儿科学 | 403篇 |
妇产科学 | 166篇 |
基础医学 | 2707篇 |
口腔科学 | 410篇 |
临床医学 | 1309篇 |
内科学 | 5120篇 |
皮肤病学 | 379篇 |
神经病学 | 1809篇 |
特种医学 | 764篇 |
外科学 | 3346篇 |
综合类 | 86篇 |
预防医学 | 570篇 |
眼科学 | 572篇 |
药学 | 1291篇 |
中国医学 | 44篇 |
肿瘤学 | 2241篇 |
出版年
2023年 | 131篇 |
2022年 | 250篇 |
2021年 | 450篇 |
2020年 | 231篇 |
2019年 | 356篇 |
2018年 | 451篇 |
2017年 | 371篇 |
2016年 | 465篇 |
2015年 | 471篇 |
2014年 | 610篇 |
2013年 | 749篇 |
2012年 | 1262篇 |
2011年 | 1407篇 |
2010年 | 754篇 |
2009年 | 644篇 |
2008年 | 1233篇 |
2007年 | 1393篇 |
2006年 | 1292篇 |
2005年 | 1418篇 |
2004年 | 1354篇 |
2003年 | 1334篇 |
2002年 | 1252篇 |
2001年 | 273篇 |
2000年 | 207篇 |
1999年 | 290篇 |
1998年 | 291篇 |
1997年 | 220篇 |
1996年 | 194篇 |
1995年 | 200篇 |
1994年 | 147篇 |
1993年 | 141篇 |
1992年 | 162篇 |
1991年 | 149篇 |
1990年 | 132篇 |
1989年 | 133篇 |
1988年 | 119篇 |
1987年 | 122篇 |
1986年 | 106篇 |
1985年 | 63篇 |
1984年 | 75篇 |
1983年 | 65篇 |
1982年 | 40篇 |
1981年 | 48篇 |
1980年 | 45篇 |
1979年 | 43篇 |
1978年 | 40篇 |
1977年 | 23篇 |
1976年 | 21篇 |
1975年 | 28篇 |
1974年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Association of Epstein-Barr virus with oral cancers 总被引:2,自引:0,他引:2
72.
73.
Two cell lines designated IC-KMS and D-KMS were established from human adenovirus type 12-induced tumors of C3Hf/OK mouse. The cell lines retained the characteristics of the original tumor i.e., production of numerous C-type and intracisternal A-type particles, integration of Ad12 E1 region DNA and amplification of the myc gene family. Chromosomal analysis revealed chromosome aberrations in both IC-KMS and D-KMS cells. The modal chromosome number of IC-KMS cells was 54 and that of D-KMS cells was 48. Metacentric chromosomes and minichromosomes were found. Trisomy of chromosome 3, 7 and 12 was seen frequently in D-KMS cells. Although DNA aneuploidy was revealed by flow cytometry, the DNA indices of these cells showed no relation to the copy number of integrated Ad12 DNA. These cells have been propagated by serial culture during the past 17 months. Production of endogenous virus particles is a unique characteristic of IC-KMS and D-KMS cells. These cell lines would be useful materials for examining the contribution of Ad12 carcinogenesis to activation of endogenous virus particles, and also the correlation between Ad12 carcinogenesis and cancer-related genes. 相似文献
74.
BACKGROUND: Japanese cedar pollinosis is an important allergic rhinoconjunctivitis in Japan in spring. We investigated the relationship between the amount of pollen in the air and the prevalence of the disease and sensitization to Japanese cedar pollen in this ecological study. METHODS: The IgE antibody to Japanese cedar pollen (JCP-IgE) was determined in human serum and rhinoconjunctival symptoms were surveyed in 407-510 children in May or June every year from 1995 to 2001. Japanese cedar pollinosis was defined as being JCP-IgE >or=1.5 IU/ml and having any rhinoconjunctival symptom lasting 3 weeks or longer in March or April. RESULTS: Prevalence rates of Japanese cedar pollinosis were 13.8-22.9%. Prevalence rates of being JCP-IgE >or=1.5 IU/ml were 39.0-50.1%, and those of being JCP-IgE >or=15.01 IU/ml were 11.4-23.2%. All prevalence rates were significantly related to the amount of pollen in the air. The proportion of subjects with rhinoconjunctival symptoms was relatively constant in each stratum of low JCP-IgE levels (<0.35, 1.50-2.99, 3.0-14.9 IU/ml). CONCLUSION: High exposure to Japanese cedar pollen was associated with higher levels of JCP-IgE antibody and a high prevalence of Japanese cedar pollinosis. The relationship between the level of JCP-IgE and the proportion of subjects with symptoms was relatively constant. 相似文献
75.
76.
Kenji Kashima Shigeo Yokoyama Tsutomu Daa Iwao Nakayama Torn Iwaki 《Virchows Archiv : an international journal of pathology》1997,430(4):333-338
The influence of free radicals on apoptosis was studied in the human heart; 45 autopsy cases were examined by the nick end labelling method (NELM) that detects DNA fragmentation. Immunostaining for copper-zinc superoxide dismutase (CuZn-SOD) and tissue transglutaminase (tTG) induced frequently during apoptosis were also studied. Positive immunoreaction for tTG was detected in mucinous degeneration of myocardial cells; these same cells were also positive for CuZn-SOD but negative for NELM. Myocardial cells showing basophilic alterations after haematoxylin and eosin staining were also positive for CuZn-SOD but negative for the other markers examined. Positive nuclear reaction by NELM was only observed in myocardial cells showing contraction band necrosis or irregularly shaped nuclei surrounding recent or long-standing infarcted foci. In these the other two markers were negative. Since mucinous degeneration lacks the distinguishing morphological features of apoptosis, immunoreactive tTG in this lesion may not imply that the cells are undergoing apoptosis. tTG can be induced in non-apoptotic conditions and may not be involved in apoptosis induced by infarction. Histological disassociation between CuZn-SOD expression and apoptosis suggests the possibility of a cytoprotective role played by endogenous CuZn-SOD against free radical generation in the human heart. 相似文献
77.
A case with multiple myeloma in which serum forms gel precipitation upon exposure to air 总被引:1,自引:0,他引:1
Oita T Yamashiro A Sakizono K Etoh M Mizutani F Imoto S Nagai K Kasakura S 《Rinsho byori. The Japanese journal of clinical pathology》2002,50(4):404-409
We present the case of a 69-years-old man who was admitted to hospital with multiple myeloma. IgG-kappa type monoclonal protein was detected in the serum. When we separated the serum obtained from blood sample of the patient and the lid of the collecting tube was opened, the patient's serum became gelled immediately. When the lid of the collecting tube remained closed, the patient's serum did not become gelled even at 4 degrees C. Moreover, the gelled serum of the patient did not resolve at 56 degrees C. Taken together, these results indicated that gel formation of the patient's serum may not be due to cryoglobulin. It was found that the pH of the patient's serum elevated to pH 8.0 quickly after exposed to air. It was also found that the patient's serum, but not the sera of other IgG-kappa multiple myeloma patients, became gelled as soon as PBS of pH 8.0 was added. These results highly suggest that the patient's serum becomes gelled at pH 8.0. However, the isoelectric focusing of isolated precipitation in the patient showed fractions around the pH 8.5-8.7 zone, which was different from the pH at which the precipitation began to form. We think that this may be the first report of a multiple myeloma patient whose serum becomes gelled after exposed to air. 相似文献
78.
Summary We report on a sporadic case satisfied with a proposed diagnostic criteria for Cohen syndrome. This 10 year-old Japanese boy
had truncal obesity, short stature, mild mental retardation, hypotonia, maxillary hypoplasia, micrognathia, narrow hands and
feet, high-arched palate, prominent upper central incisors, high nasal bridge, but no pigmentary retinopathy. Autosomal recessive
manner of inheritance was suggested by the pedigree. 相似文献
79.
A case of multiple myeloma (IgA-Λ) with marked granulocytosis, which measured up to 9.9×104/mm3 , Is described. Matured neutrophiles were predominant and blasts were not found in the peripheral blood. The serum granulocyte colony-stimulating factor (G-CSF) was notably elevated. The disease ran a chronic course and granulocytosis and elevated serum G-CSF continued. The patient developed atelectasis and bronchopneumonia, and died of respiratory failure. At autopsy, bone marrow showed marked myeloid hyperplasia in varying states of differentiation. The enlarged spleen also disclosed numerous myeloid cells of varying differentiation. Small aggregations of atypical plasma cells were present in the marrow and spleen. Immunohisto-chemically, atyplcal plasma cells were positive for anti-G-CSF antibody, which Indicated G-CSF secretion from the myeloma cells. To our knowledge, this is the first reported case of G-CSF-producing multiple myeloma. 相似文献
80.
A simple and rapid method for the determination of macrophage activating factor is described. A new type of apparatus suitable for the measurement of macrophage chemiluminescence was devised, and the effect of lymphokines on macrophage activities was studied by measuring phorbol myristate acetate-induced luminol-dependent chemiluminescence. An outstanding feature of the new apparatus is that the plastic dish used for the cell culture can be used as the vessel for the chemiluminescence reaction. When thioglycollate-elicited ICR mouse peritoneal macrophages were incubated with lymphokines, their ability to generate chemiluminescence increased rapidly, reaching a maximal level at about 4 h, and then it progressively decreased to the control level at 8 h. Although this increasing effect of lymphokines on macrophage chemiluminescence was short-lived, it could be seen at a relatively low concentration, at which lymphokine-mediated cytotoxic activity of macrophages was not observed. 相似文献