全文获取类型
收费全文 | 8676篇 |
免费 | 361篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 79篇 |
妇产科学 | 65篇 |
基础医学 | 1007篇 |
口腔科学 | 285篇 |
临床医学 | 712篇 |
内科学 | 1885篇 |
皮肤病学 | 272篇 |
神经病学 | 564篇 |
特种医学 | 456篇 |
外科学 | 1613篇 |
综合类 | 50篇 |
一般理论 | 1篇 |
预防医学 | 388篇 |
眼科学 | 78篇 |
药学 | 693篇 |
中国医学 | 28篇 |
肿瘤学 | 832篇 |
出版年
2023年 | 40篇 |
2022年 | 89篇 |
2021年 | 152篇 |
2020年 | 90篇 |
2019年 | 127篇 |
2018年 | 167篇 |
2017年 | 108篇 |
2016年 | 147篇 |
2015年 | 141篇 |
2014年 | 191篇 |
2013年 | 232篇 |
2012年 | 393篇 |
2011年 | 442篇 |
2010年 | 256篇 |
2009年 | 181篇 |
2008年 | 351篇 |
2007年 | 382篇 |
2006年 | 372篇 |
2005年 | 355篇 |
2004年 | 356篇 |
2003年 | 353篇 |
2002年 | 328篇 |
2001年 | 297篇 |
2000年 | 314篇 |
1999年 | 300篇 |
1998年 | 130篇 |
1997年 | 69篇 |
1996年 | 69篇 |
1995年 | 85篇 |
1994年 | 71篇 |
1993年 | 51篇 |
1992年 | 218篇 |
1991年 | 197篇 |
1990年 | 218篇 |
1989年 | 220篇 |
1988年 | 173篇 |
1987年 | 192篇 |
1986年 | 161篇 |
1985年 | 154篇 |
1984年 | 102篇 |
1983年 | 83篇 |
1981年 | 50篇 |
1979年 | 94篇 |
1978年 | 41篇 |
1977年 | 52篇 |
1974年 | 47篇 |
1972年 | 39篇 |
1971年 | 41篇 |
1969年 | 45篇 |
1968年 | 40篇 |
排序方式: 共有9097条查询结果,搜索用时 0 毫秒
61.
Nishiya K Chikazawa H Matsumori A Chijiwa T Tahara K Morita T Hosokawa T Ito H Hashimoto K Fujieda M 《Rinsho byori. The Japanese journal of clinical pathology》1999,47(2):185-187
Antineutrophil cytoplasmic antibodies (ANCA) for two antigens, i.e. myeloperoxidase (MPO) and lactoferrin (LF) in sera from 19 IgA nephropathy (IgAN), 3 adult Henoch-Sch?nlein purpura (HSP) and 8 child HSP patients were examined by enzyme-linked immunoabsorbent assay (ELISA) for immunoglobulin isotypes. All of child HSP patients showed negative ANCA. On the other hand, one IgAN patient and two adult HSP patients showed weak positivity for IgA class anti-MPO antibody. There was no patients who showed positivity for IgG and IgM class anti-MPO antibody. In anti-LF antibody, one IgAN and one adult HSP showed positivity in IgG class; 2 IgAN and 2 HSP in IgA class and 2 IgAN and one HSP in IgM class. These results indicate that adult HSP patients have higher prevalence of IgA class anti-MPO antibody and anti-LF antibody than IgAN or child HSP. 相似文献
62.
Cloning and characterization of the cDNA encoding the HA protein of a hemagglutination-defective measles virus strain 总被引:3,自引:0,他引:3
Hiroyuki Saito Hiroyasu Sato Mariko Abe Seizaburo Harata Ken-Ichi Amano Tsunehisa Suto Morihiro Morita 《Virus genes》1994,8(1):107-113
cDNA clones corresponding to the mRNA for the hemagglutinin of the hemagglutination-defective strain AK-1 of measles virus were isolated and characterized. Compared with the prototype Edmonstron strain, 60 nucleotide substitutions that resulted in 18 amino acid changes were detected. An additional potential N-linked glycosylation site was added by point mutation, which was supported by the observation that the hemagglutinin of the AK-1 strain was stained more heavily after NaDodSO4PAGE and periodic acid-Schiff (PAS) staining than the Edmonston strain. Computer-assisted analysis revealed that three reverse turns in the secondary structure had disappeared in the hemagglutinin of the AK-1 strain. Moreover, one of these structural changes occurred in the closely glycosylated region at amino acid residues 168–240, which appeared to be a biologically important functional domain. The isoelectric point calculated from the predicted amino acid sequence became about 1 pH unit more basic in the AK-1 strain than the Edmonston strain. This present study is the first sequence analysis of the hemagglutinin gene in a hemagglutination-defective strain of the measles virus. 相似文献
63.
Four hundred and sixty-five male and 159 female consecutive autopsy cases of lung cancer, autopsied over the 27 years from 1958 to 1984, were analysed and were compared with other materials and mortality statistics, including statistics from other countries. Malignant tumor autopsy cases are gradually increasing and now comprise more than 60% of total autopsy cases. The percentage of lung cancer cases among all autopsy cases was 7% in males and 4% in females. The percentage of lung cancer in autopsies of patients with malignancies was about 13% for males and 9% for females. The most frequent fatal malignant tumors were gastric cancer, lung cancer, and leukemia. The relative incidence of gastric cancer was decreasing, while that of lung cancer was increasing. In the distribution of the histological types of lung cancer, adenocarcinomas were the most frequent types in both sexes. As has been noted in mortality statistics, we noticed a gradual shift in the peak age of lung cancer autopsy cases towards older patients. During the period under study, the peak shifted from patients in their sixties to patient in their seventies; this was true for most of the major histological types in both sexes. The male/female ratio of all lung cancer cases was 2.9, which was much lower than the ratio found in the United States and Europe, and very similar to the ratio of the mortality rates in Japan and other Asian countries. It was pointed out that the male/female ratios by age-group in each country is a very good reflection of the histological distribution. 相似文献
64.
Autopsy cases of lung cancer, 41,988 in males and 13,818 in females, consecutively registered between 1958 and 1987, were analysed statistically and compared with other case materials and mortality statistics. Cases of malignant tumor showed a gradual increase, and now comprise 60% of the total male and 55% of the total female autopsy cases. The percentage of lung cancer cases among the total autopsy cases was 9% for males and 5% for females. The percentage of lung cancer cases among total cases of malignant tumor was about 17% for males and 9% for females. Among fatal malignant tumors, gastric cancer and lung cancer showed the highest frequency. The relative incidence of gastric cancer was seen to decrease, whereas that of lung cancer increased. Of the histological types of lung cancer in both sexes, adenocarcinoma was the most frequent, followed by squamous cell carcinoma. During the period studied the peak age of patients with lung cancer shifted from the seventh to eighth decade, and a significant elevation of mean age was demonstrated for all of the major histological types in both sexes. The male:female ratio for all lung cancer cases was 3.0, which was much lower than those for the United States and Europe, but very similar to the ratios of mortality statistics in Japan and other Asian countries. As a result of a previous autopsy study at the University of Tokyo, it was also confirmed that the male:female ratio relative to age in each country reflects very well the histological distribution. 相似文献
65.
Nishioji K Okanoue T Itoh Y Narumi S Sakamoto M Nakamura H Morita A Kashima K 《Clinical and experimental immunology》2001,123(2):271-279
To clarify the role of IP-10 in autoimmune liver diseases, we studied the serum levels of IP-10 in 14 patients with autoimmune hepatitis (AIH), 23 patients with primary biliary cirrhosis (PBC), and 65 patients with chronic viral hepatitis (20 type B and 45 type C). The hepatic expression of IP-10 mRNA and the correlation between the serum levels of IP-10 and clinical parameters were also evaluated. In addition to 20 healthy controls, 16 rheumatoid arthritis (RA) patients were included as an extrahepatic inflammatory disease. The serum level of IP-10 was significantly (P < 0.02) higher in patients with AIH, PBC, and chronic hepatitis B and C than in healthy controls, and it was significantly correlated (P < 0.05) with the serum levels of aspartate aminotransferase and alanine aminotransferase in patients with AIH, PBC, and chronic hepatitis B and C. The serum level of IP-10 was not elevated in RA patients. After successful treatment of AIH and chronic hepatitis C, the serum level of IP-10 decreased to the same level as in healthy volunteers. As we previously showed in cases with chronic hepatitis B or C, in situ hybridization in both AIH and PBC cases demonstrated the expression of IP-10 mRNA in hepatocytes around focal or lobular necrosis surrounded by infiltrating mononuclear cells, whereas IP-10 mRNA was not expressed in areas around the damaged bile ducts in PBC cases. The present results suggest that IP-10 is specifically produced by hepatocytes in inflammatory areas irrespective of the aetiology of hepatitis, and that IP-10 may help to recruit T cells to the hepatic lesions in autoimmune liver diseases as well as in chronic viral hepatitis. 相似文献
66.
Susumu Harada Maya Iijima Akiko Nakamura Yoshitsugu Yoshizaki Hiroaki Matsuo Eisin Morita 《Arerugī》2007,56(1):41-48
BACKGROUND: Either omega-5 gliadin or high molecular weight glutenin is known to be a major allergen in wheat-dependent exercise-induced anaphylaxis (WDEIA). It is generally considered that gluten specific IgE score is more reliable than that of wheat specific IgE score for the diagnosis of WDEIA. Our aim was to verify the significance of gluten specific IgE in the diagnosis of WDEIA. METHODS: We evaluated the result of gluten CAP-RAST score and omega-5 gliadin specific IgE score on four WDEIA patients who visited our hospital during the years 2004 and 2005, whose diagnosis were onfirmed by prick tests, immunoblot tests and provocation tests. RESULTS: Contrary to our expectations, all four patients showed negative gluten CAP-RAST scores, however all patient's omega-5 gliadin specific IgE scores were positive. CONCLUSION: Our results suggest that gluten specific CAP-RAST score is unreliable in the diagnosis of WDEIA. On the other hand omega-5 gliadin specific IgE score is possibly a better candidate as a diagnostic tool for WDEIA. 相似文献
67.
Yuichi Takeoka Shao-Yuan Chen Richard L. Boyd Koichi Tsuneyama Nobuhisa Taguchi Shinji Morita Hisashi Yago Seishi Suehiro Aftab A. Ansari Leonard D. Shultz M. Eric Gershwin 《Clinical & developmental immunology》1997,5(2):79-89
It is widely accepted that the thymic microenvironment regulates normal thymopoiesis
through a highly coordinated and complex series of cellular and cytokine interactions. A direct
corollary of this is that abnormalities within the microenvironment could be of etiologic
significance in T-cell-based diseases. Our laboratory has developed a large panel of
monoclonal antibodies (mAbs) that react specifically with epithelial or nonepithelial
markers in the thymus. We have taken advantage of these reagents to characterize the
thymic microenvironment of several genetic strains of mice, including BALB/cJ,
C57BL/6J, NZB/BlnJ, SM/J, NOD/Ltz, NOD/Ltz-scid/sz, C57BL/6J-Hcph
me/Hcph me, and
ALY/NscJcl-aly/aly mice, and littermate control animals. We report herein that control
mice, including strains of several backgrounds, have a very consistent phenotypic profile
with this panel of monoclonal antibodies, including reactivity with thymic epithelial cells
in the cortex, the medulla and the corticomedullary junction, and the extracellular matrix.
In contrast, the disease-prone strains studied have unique, abnormal staining of thymic cortex
and medulla at both the structural and cellular levels. These phenotypic data suggest
that abnormalities in interactions between developing thymocytes and stromal cells characterize
disease-prone mice. 相似文献
68.
69.
Stimulatory effect of vasoactive intestinal polypeptide on catecholamine secretion from isolated guinea pig adrenal chromaffin cells 总被引:1,自引:0,他引:1
The stimulatory effect of vasoactive intestinal polypeptide (VIP) on catecholamine (CA) secretion from isolated guinea pig adrenal chromaffin cell was studied. VIP (1-10 microM) induced dose-dependent CA secretion, which was slow and continued for at least 30 min. This VIP-induced CA secretion was dependent on the presence of Ca2+ in the medium, but no significant increase in Ca2+ uptake by the cells was observed during their stimulation with VIP. Studies on the intracellular free Ca2+ level ([Ca2+]i) using fura-2 showed that acetylcholine and muscarine induced a marked increase in the [Ca2+]i, but that VIP induced only a slight increase. Thus VIP may induce CA secretion by increasing the sensitivity of the secretion of CA to Ca2+. 相似文献
70.
Watanabe M Shin'oka T Tohyama S Hibino N Konuma T Matsumura G Kosaka Y Ishida T Imai Y Yamakawa M Ikada Y Morita S 《Tissue engineering》2001,7(4):429-439
Tissue-engineered vascular autografts (TEVAs) were made by seeding 4-6 x 10(6) of mixed cells obtained from femoral veins of mongrel dogs onto tube-shaped biodegradable polymer scaffolds composed of a polyglycolid acid (PGA) nonwoven fabric sheet and a copolymer of L-lactide and caprolactone (n = 4). After 7 days, the inferior vena cavas (IVCs) of the same dogs were replaced with TEVAs. After 3, 4, 5, and 6 months, angiographies were performed, and the dogs were sacrificed. The implanted TEVAs were examined both grossly and immunohistologically. The implanted TEVAs showed no evidence of stenosis or dilatation. No thrombus was found inside the TEVAs, even without any anticoagulation therapy. Remnants of the polymer scaffolds were not observed in all specimens, and the overall gross appearance similar to that of native IVCs. Immunohistological staining revealed the presence of factor VIII positive nucleated cells at the luminal surface of the TEVAs. In addition, lesions were observed where alpha-smooth muscle actin and desmin positive cells existed. Implanted TEVAs contained a sufficient amount of extracellular matrix, and showed neither occlusion nor aneurysmal formation. In addition, endothelial cells were found to line the luminal surface of each TEVA. These results strongly suggest that "ideal" venous grafts with antithrombogenicity can be produced. 相似文献