全文获取类型
收费全文 | 22704篇 |
免费 | 1001篇 |
国内免费 | 184篇 |
专业分类
耳鼻咽喉 | 233篇 |
儿科学 | 431篇 |
妇产科学 | 283篇 |
基础医学 | 2866篇 |
口腔科学 | 483篇 |
临床医学 | 1489篇 |
内科学 | 5974篇 |
皮肤病学 | 591篇 |
神经病学 | 1789篇 |
特种医学 | 856篇 |
外科学 | 3467篇 |
综合类 | 59篇 |
一般理论 | 5篇 |
预防医学 | 643篇 |
眼科学 | 720篇 |
药学 | 1515篇 |
中国医学 | 45篇 |
肿瘤学 | 2440篇 |
出版年
2023年 | 128篇 |
2022年 | 313篇 |
2021年 | 538篇 |
2020年 | 269篇 |
2019年 | 356篇 |
2018年 | 447篇 |
2017年 | 348篇 |
2016年 | 444篇 |
2015年 | 499篇 |
2014年 | 628篇 |
2013年 | 759篇 |
2012年 | 1294篇 |
2011年 | 1385篇 |
2010年 | 842篇 |
2009年 | 707篇 |
2008年 | 1240篇 |
2007年 | 1423篇 |
2006年 | 1309篇 |
2005年 | 1483篇 |
2004年 | 1441篇 |
2003年 | 1349篇 |
2002年 | 1364篇 |
2001年 | 447篇 |
2000年 | 366篇 |
1999年 | 436篇 |
1998年 | 366篇 |
1997年 | 266篇 |
1996年 | 269篇 |
1995年 | 223篇 |
1994年 | 197篇 |
1993年 | 203篇 |
1992年 | 254篇 |
1991年 | 210篇 |
1990年 | 225篇 |
1989年 | 219篇 |
1988年 | 163篇 |
1987年 | 154篇 |
1986年 | 153篇 |
1985年 | 132篇 |
1984年 | 101篇 |
1983年 | 83篇 |
1982年 | 66篇 |
1981年 | 67篇 |
1980年 | 49篇 |
1979年 | 103篇 |
1978年 | 76篇 |
1977年 | 60篇 |
1975年 | 37篇 |
1973年 | 38篇 |
1969年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Neutrophil elastase inhibitor reduces hepatic metastases induced by ischaemia-reperfusion in rats. 总被引:2,自引:0,他引:2
Koji Doi Tetsuya Horiuchi Masaru Uchinami Takanori Tabo Narisato Kimura Jun Yokomachi Makoto Yoshida Kuniyoshi Tanaka 《Acta chirurgica》2002,168(8-9):507-510
OBJECTIVE: To investigate the possibility in rats that ONO-5046 Na, a new recombinant inhibitor of neutrophil elastase, can reduce hepatic metastases induced by ischaemia-reperfusion. DESIGN: Laboratory experimental study. SETTING: Research laboratory, Japan. SUBJECTS: Male Fischer rats. INTERVENTIONS: Rats underwent 60 min of 70% partial hepatic ischaemia, after which rat colon adenocarcinoma cells (RCN-H4) were injected into the spleen. The animals were divided into two test groups and a control group. One group was given ONO-5046 Na intravenously at 10 mg/kg/hour. A second group was given a saline solution for the same period, while the controls were not made ischaemic. MAIN OUTCOME MEASURES: Three weeks after inoculation, the number of tumour nodules on the liver surface was counted. The anti-cancer effect of ONO-5046 Na was measured by monotetrazolium assay. RESULTS: Hepatic ischaemia-reperfusion increased the number of liver metastases of RCN-H4 in both clamped and unclamped hepatic lobes. ONO-5046 Na significantly inhibited this in unclamped lobes, but had no anti-cancer effect. CONCLUSION: Neutrophil elastase may have an important role in increasing haematogenous liver metastases by ischaemia-reperfusion, particularly in unclamped lobes. 相似文献
52.
SeveralChlorellavirus CVK2 proteins had chitosanase and/or chitinase activities. A gene coding for an ORF of 328 amino acids (aa) with a predicted molecular mass of 36,769 Da was cloned from the viral genome. The predicted amino acid sequence of an N′-portion (174 aa) of this gene product (vChta-1) showed 22 to 25% identity with various bacterial chitosanases. A glutathioneS-transferase (GST)–vChta-1 fusion protein had strong chitosanase activity. Western blot analysis with antisera raised against the vChta-1 protein identified two proteins of 37 and 65 kDa in virus-infectedChlorellacells beginning at 240 min postinfection and continuing until cell lysis. The larger protein was packaged in the virion, while the smaller one remained in the cell lysate. Both chitosanase proteins were produced from the single gene,vChta-1,by a mechanism of alternative gene expression. 相似文献
53.
MRI in subacute combined degeneration 总被引:13,自引:0,他引:13
We describe a patient with clear lesions in the spinal cord on MRI due to subacute combined degeneration. T2-weighted images clearly showed abnormal high signals in the posterior columns, which disappeared on recovery from the disease. 相似文献
54.
Makoto Watanabe Takashi Fujimoto Masayuki Iwano Hideo Shiiki Shinobu Nakamura 《Nihon Rinshō Men'eki Gakkai kaishi》2002,25(2):191-198
We describe the case of a 61-year-old woman diagnosed with primary Sj?gren's syndrome (SS) after an 8-year history of IgA nephropathy and a 3-year history of recurrent purpuric rashes. Her two daughters had previously been diagnosed with other autoimmune diseases. One daughter had Graves' disease and the other had Hashimoto's disease and systemic lupus erythematosus. The diagnosis of SS was made based on dryness of mucous membranes, Shirmer test, and parotid sialography. Thrombocytopenia, high platelet-aggregated IgG (PA-IgG) level, and normal megakaryocytes count in bone marrow suggested that her recurrent purpuric rashes were due to idiopathic thrombocytopenic purpura (ITP). Patients with SS may develop other autoimmune diseases. This case aids understanding of the immune pathogenesis and genetic background of SS. 相似文献
55.
56.
Seiji Sakate Chieko Megumi Masatsugu Kobayashi Kazuhiro Murata Kiyonobu Sakagami Takashi Kimura 《SANGYO EISEIGAKU ZASSHI》2003,45(5):201-205
The serum triglyceride concentration (TG) tested in health checks after meals cannot properly sort out hypertriglyceridemia with reference to the upper normal limit of fasting TG (150 mg/dl) set by the Japan Arteriosclerosis Society, because TG goes up considerably after a meal. In our survey of a large number of health check examinees (free of abnormal biochemical data other than TG and diseases under medical treatment), the mean (M) of fasting TG + 2 standard deviations (SD) was close to 150 mg/dl. When the screening level was set at M + 2SD for each time span after a meal, the ratio of the screened was distributed between 19.9 and 21.8%, which was close to 23.5%, the ratio of the screened on fasting. Accordingly, the nearest round number ending with zero for the first digit is suggested to be of practical use for the screening level of after-meal TG. The average TG in females was definitely lower than that of males, though proportionately increasing with age. The ratio of the screened among females aged between 20 and 49 was 5.3% on fasting and 3.2-5.8% for after-meal time spans, and that of the screened aged in their fifties was 11.3% and 8.2-12.9% respectively. 相似文献
57.
Estrogenic Induction of NADPH- Diaphorase Activity in the Preoptic Neurons Containing Estrogen Receptor Immunoreactivity in the Female Rat 总被引:1,自引:0,他引:1
Nitric oxide and estrogen have been shown to play a critical role in the control of female reproductive function. In order to determine an anatomical relationship between nitric oxide generating neurons and estrogen target neurons, NADPH-diaphorase histochemistry was combined with estrogen receptor immunohistochemistry in the female medial preoptic area. While only a few weakly stained neurons for NADPH-diaphorase were found in ovariectomized control rats, a drastic increase in NADPH-diaphorase activity was observed in the medial preoptic nucleus of estradiol-treated ovariectomized animals. The total number of NADPH-diaphorase neurons in the estradiol-treated group increased three-fold relative to controls, and more than 80% of those neurons contained estrogen receptor-immunoreactivity in their nuclei. Since neuronal NADPH-diaphorase is nitric oxide synthase, the present result suggests that nitric oxide synthase activity can be positively regulated by estradiol in neurons containing estrogen receptor in the female medial preoptic nucleus. 相似文献
58.
K Nishi M Yamada D Morishita Y Nakamura Y Murata M Fujioka S Muramoto S Murakami K Sasaki M Yasui 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(7):904-908
A rare case of a 25-year-old man with pulmonary aspergillosis is reported. Pulmonary bulla and eosinophilic pneumonia in the right upper lobe were diagnosed by chest roentgenogram and transbronchial lung biopsy. Because the patient developed infective bullae during steroid therapy, we performed transcutaneous thoracic drainage and right upper lobectomy. The resected lung tissue contained numerous hyphae of Aspergillus. Around the hyphae of Aspergillus, granulomatous reaction and eosinophilic infiltration were observed. Antibodies against Aspergillus were detected in the serum of the patient. The number of peripheral blood eosinophils decreased after right upper lobectomy. These findings suggest that pulmonary bullae and eosinophilic pneumonia may be a rare manifestation of pulmonary aspergillosis. 相似文献
59.
Koichi Shimizu M.D. Hirokuni Arai M.D. Tohru Sakamoto M.D. Makoto Sunamori M.D. Akio Suzuki M.D. 《Journal of cardiac surgery》1997,12(3):198-200
A bstract A 61-year-old woman suffering from Jarcho-Levin syndrome (JLS) was associated with atrial septal defect and partial anomalous pulmonary venous return and underwent corrective surgery. Pressure controlled postoperative ventilator therapy is preferred in patients with JLS. 相似文献
60.
Active oxygen species generated by monocytes and polymorphonuclear cells in Crohn's disease 总被引:4,自引:0,他引:4
Tetsuji Kitahora MD Koichi Suzuki MD Hitoshi Asakura MD Takeshi Yoshida MD Makoto Suematsu MD Mamoru Watanabe MD Sadakazu Aiso MD Dr. Masaharu Tsuchiya MD 《Digestive diseases and sciences》1988,33(8):951-955
Chemiluminescence (CL) analysis of monocytes and polymorphonuclear cells (PMNs) was performed on 13 patients with Crohn's disease (CD) and 10 healthy volunteers. The percentages of monocyte populations in mononuclear cells obtained from the patients with CD were greater than those from the healthy volunteers, but the numbers of PMNs were not different between the two groups. The peak level of phorbol myristate acetate (PMA)-induced CL activity generated by diluted whole blood from the patients with CD was more significantly elevated than that from the healthy volunteers, whereas the peak levels of opsonized zymosan-induced CL activity did not differ between the two groups. In monocytes, the peak levels of both PMA- and opsonized zymosan-induced CL activity were significantly higher in the patients with CD than in the healthy volunteers. CL in PMNs, however, showed no significant difference between CD and controls. It is suggested that monocytes of CD have a large capacity to generate active oxygen species. The present study suggests that excessive active oxygen species released by monocytes and perhaps macrophages may play an important role in formation of the intestinal lesions in CD.This work was supported by the Grant of Tokuteishitsukan from the Japanese Ministry of Welfare and Health. 相似文献