全文获取类型
收费全文 | 11514篇 |
免费 | 515篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 225篇 |
妇产科学 | 123篇 |
基础医学 | 1530篇 |
口腔科学 | 188篇 |
临床医学 | 767篇 |
内科学 | 2766篇 |
皮肤病学 | 131篇 |
神经病学 | 809篇 |
特种医学 | 481篇 |
外科学 | 2393篇 |
综合类 | 25篇 |
预防医学 | 290篇 |
眼科学 | 259篇 |
药学 | 964篇 |
中国医学 | 46篇 |
肿瘤学 | 1025篇 |
出版年
2023年 | 56篇 |
2022年 | 118篇 |
2021年 | 192篇 |
2020年 | 94篇 |
2019年 | 144篇 |
2018年 | 207篇 |
2017年 | 154篇 |
2016年 | 156篇 |
2015年 | 187篇 |
2014年 | 251篇 |
2013年 | 284篇 |
2012年 | 464篇 |
2011年 | 531篇 |
2010年 | 272篇 |
2009年 | 209篇 |
2008年 | 465篇 |
2007年 | 494篇 |
2006年 | 479篇 |
2005年 | 506篇 |
2004年 | 480篇 |
2003年 | 454篇 |
2002年 | 525篇 |
2001年 | 337篇 |
2000年 | 398篇 |
1999年 | 380篇 |
1998年 | 147篇 |
1997年 | 99篇 |
1996年 | 127篇 |
1995年 | 105篇 |
1994年 | 104篇 |
1993年 | 109篇 |
1992年 | 347篇 |
1991年 | 324篇 |
1990年 | 282篇 |
1989年 | 325篇 |
1988年 | 284篇 |
1987年 | 260篇 |
1986年 | 254篇 |
1985年 | 241篇 |
1984年 | 151篇 |
1983年 | 125篇 |
1982年 | 60篇 |
1979年 | 126篇 |
1978年 | 91篇 |
1977年 | 57篇 |
1975年 | 64篇 |
1974年 | 58篇 |
1973年 | 53篇 |
1972年 | 50篇 |
1969年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
Potentiating effect of inhaled acetaldehyde on bronchial responsiveness to methacholine in asthmatic subjects.
下载免费PDF全文
![点击此处可从《Thorax》网站下载免费的PDF全文](/ch/ext_images/free.gif)
BACKGROUND--It has recently been reported that acetaldehyde induces bronchoconstriction indirectly via histamine release. However, no study has been performed to assess whether acetaldehyde worsens bronchial responsiveness in asthmatic subjects so this hypothesis was tested. METHODS--Methacholine provocation was performed on three occasions: (1) after pretreatment with oral placebo and inhaled saline (P-S day), (2) after placebo and inhaled acetaldehyde (P-A day), and (3) after a potent histamine H1 receptor antagonist terfenadine and acetaldehyde (T-A day) in a double blind, randomised, crossover fashion. Nine asthmatic subjects inhaled 0.8 mg/ml acetaldehyde or saline for four minutes. After each inhalation a methacholine provocation test was performed. RESULTS--Methacholine concentrations producing a 20% fall in FEV1 (PC20-MCh) on the P-A day (0.48 mg/ml, 95% CI 0.21 to 1.08) and T-A day (0.41 mg/ml, 95% CI 0.22 to 0.77) were lower than those on the P-S day (0.85 mg/ml, 95% CI 0.47 to 1.54). There was no change in the PC20-MCh between the P-A and T-A days. A correlation was observed between the logarithmic values of PC20-MCh (log PC20-MCh) on the P-S day and the potentiating effect of acetaldehyde on the methacholine responsiveness [(log PC20-MCh on P-A day)-(log PC20-MCh on P-S day)] (rho = 0.82). CONCLUSIONS--Acetaldehyde induces bronchial hyperresponsiveness in patients with asthma by mechanisms other than histamine release. 相似文献
42.
T Bando K Nishi T Ohka M Yasui M Fujimura T Matsuda 《Nihon Kyōbu Shikkan Gakkai zasshi》1992,30(5):856-861
We evaluated the bronchial hyperresponsiveness to methacholine in the two cases of eosinophilic pneumonia with infiltration of eosinophils into bronchial mucosa. Bronchial responsiveness was not increased in either case in spite of marked infiltration of eosinophils into the bronchial mucosa and submucosa. Hypodense eosinophils are reported in the sputum of patients with bronchial asthma. This suggests that infiltration of activated eosinophils into the bronchial mucosa is an essential factor in bronchial hyperresponsiveness. 相似文献
43.
Lugol-combined endoscopic detection of minute malignant lesions of the thoracic esophagus. 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Annals of surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Early-stage esophageal carcinomas, particularly cases of intraepithelial carcinoma and mucosal carcinoma, are extremely difficult to detect because the patients have no particular complaints, and findings on the x-rays are nil. At present, endoscopic examination is the only tool of any value for discerning such lesions. Lugol-combined endoscopy with biopsy has proven to be most effective for detecting the presence and spread of small malignant lesions of the esophagus. Studies were conducted on the diagnostic features of one intraepithelial, five mucosal and 29 submucosal carcinomas of the esophagus, detected through the use of Lugol-combined endoscopy. 相似文献
44.
45.
Keiichiro Wada Yumiko Motoi Yasuko Komatsuzaki Masashi Takanashi Hideo Mori Takao Urabe Yoshikuni Mizuno 《Brain and nerve》2006,58(1):79-90
We report an 81-year-old patient with progressive dementia, disinhibition, and gait disturbance. He showed visuospacial disorientation, apathy, and gait disturbance at 76 years of age. When he was 77 years old, he was diagnosed Parkinson's disease and treated with the 1-dopa, the dopamine agonist, the amantadin, and the anti-cholinergic drug. These treatments didn't improve his motor disturbances. His motor disturbances, apathy, and abnormal behavior progressed gradually. He was admitted to the hospital at the age of 77. He was severely demented and akinetic. Sometime, violent behavior and hallucination were seen. The brain MRI showed frontotemporal lobe atrophy and severe leukoaraiosis of the frontal white matter. At 79 years of age, he became mute and bedridden. When he was 80 years old, large infarction occurred in his occipital lobe. He died due to renal failure and respiratory suppression at 81 years of age. His brain was examined pathologically. At the neurological CPC, the chief discussant arrived at the conclusion that his diagnosis was Binswanger's disease. Other possibilities discussed were FTD, CBD, and progressive subcortical gliosis. The post-mortem examination revealed diffuse white matter degeneration due to atherosclerotic change of the small artery, many lacunar infarctions, and severe infarction of the occipital lobe. These findings led the diagnosis of Binswanger's disease and cerebral infarction. 相似文献
46.
Tsunao Imamura Rie Takeshita Rikako Koyama Chikao Okuda Kazuo Takeuchi Masamichi Matsuda Masashi Hashimoto Goro Watanabe Hitoshi Yoshida Michio Imawari 《Digestive endoscopy》2006,18(4):303-307
Background: Pancreatic carcinoma is one of the most lethal cancers. Because pancreatic carcinoma is still very difficult to diagnose in its early stage, many of these patients will be considered unsuitable for surgery. If a cytological diagnosis is obtained at initial endoscopic retrograde cholangiopancreatography (ERCP), suitable treatment will be initiated without delay. Methods: To increase the number of exfoliated cells from the pancreatic duct, we devised a new technique, pancreatic duct lavage fluid (PDLF), following bronchoalveolar lavage fluid. The present paper reports the effectiveness of cytological examination using PDLF in the diagnosis of pancreatic carcinoma. We examined 18 pancreatic carcinoma cases. After the endoscopic retrograde pancreatography (ERP), PDLF was collected from a double‐lumen catheter inserted into the main pancreatic duct. Saline injected from the lumen for the injection, and PDLF was aspirated from the other lumen for the guidewire at the same time. The cytological examination was performed using PDLF. Results: Exfoliated cells were more frequently found in PDLF from all patients. In 15 cases (83%), cytological examination of PDLF revealed positive cytological results as the diagnosis of pancreatic carcinoma. Conclusion: Cytological examination using PDLF has a high sensitivity for detection of pancreatic carcinoma. The new examination, PDLF, is simple, safe and effective, so we expect PDLF to become widely popular. 相似文献
47.
In order to study the effect of nef gene expression on viral replication in monocytic cells, we established monocytic (U937 and THP-1) cell transfectants constitutively expressing the human immunodeficiency virus type 1 nef gene. We constructed a plasmid expressing the nef gene derived from an infectious clone, NL432, under the control of SR alpha promoter which can drive a high level of gene expression. We found suppressed viral replication in nef-expressing monocytic cells, although a negative effect of nef was observed, with some variation depending on the virus strain and the cell. We also observed that the expression of the surface CD4 molecule is inversely related to the expression of the nef gene, especially in the U937 transfectants. These results indicate that the suppression of viral replication and the down-modulation of CD4 molecule by nef gene expression occur in monocytic cell lines as in T cell lines. 相似文献
48.
Mayumi Ujihara Sumiko Hamanaka Sachie Matsuda Fumitaka Numa Hiroshi Kato 《The Journal of dermatology》1994,21(1):56-58
A 76-year-old female was admitted with many bullae and erythema on her trunk and extremities. A biopsy specimen showed significant intercellular edema in the lower epidermis and eosinophilic infiltration into the dermis and the epidermis. Immunofluorescent staining revealed the deposition of IgG in the intercellular area of her prickle cells. From these histologic findings and the typical clinical features, we diagnosed her as having pemphigus vulgaris. Examination of her blood revealed that she also suffered from autoimmune hemolytic anemia. Despite intensive treatment with prednisolone, she finally died. This case is of interest because of its rarity and the TNFα detected significantly in the blister fluid of this patient. 相似文献
49.
K Matsuda N Tamura A Iwakura 《Kyobu geka. The Japanese journal of thoracic surgery》1992,45(10):883-885
A 62-year-old woman underwent primary anastomosis for dissecting aortic aneurysm (DeBakey IIIb) using GRF glue. GRF glue consists of mixture of gelatin and resorcin. The mixture is hardened by the addition of medical formaldehyde. Resorcin is diphenole which reacts with formaldehyde, creating tridimentional network. Primary anastomoses were performed after the lumen of dissected aorta was adhered with GRF glue. It appears that primary anastomosis using GRF glue is a simpler and safer operative method for dissecting aortic aneurysm. 相似文献
50.