全文获取类型
收费全文 | 9808篇 |
免费 | 500篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 181篇 |
儿科学 | 137篇 |
妇产科学 | 97篇 |
基础医学 | 1238篇 |
口腔科学 | 220篇 |
临床医学 | 623篇 |
内科学 | 2628篇 |
皮肤病学 | 197篇 |
神经病学 | 578篇 |
特种医学 | 358篇 |
外科学 | 1818篇 |
综合类 | 46篇 |
预防医学 | 232篇 |
眼科学 | 102篇 |
药学 | 708篇 |
中国医学 | 28篇 |
肿瘤学 | 1176篇 |
出版年
2023年 | 53篇 |
2022年 | 113篇 |
2021年 | 186篇 |
2020年 | 112篇 |
2019年 | 127篇 |
2018年 | 194篇 |
2017年 | 150篇 |
2016年 | 187篇 |
2015年 | 215篇 |
2014年 | 242篇 |
2013年 | 274篇 |
2012年 | 526篇 |
2011年 | 587篇 |
2010年 | 305篇 |
2009年 | 283篇 |
2008年 | 480篇 |
2007年 | 532篇 |
2006年 | 506篇 |
2005年 | 518篇 |
2004年 | 520篇 |
2003年 | 560篇 |
2002年 | 518篇 |
2001年 | 230篇 |
2000年 | 226篇 |
1999年 | 256篇 |
1998年 | 128篇 |
1997年 | 89篇 |
1996年 | 103篇 |
1995年 | 89篇 |
1994年 | 110篇 |
1993年 | 71篇 |
1992年 | 162篇 |
1991年 | 144篇 |
1990年 | 140篇 |
1989年 | 135篇 |
1988年 | 142篇 |
1987年 | 152篇 |
1986年 | 130篇 |
1985年 | 116篇 |
1984年 | 80篇 |
1983年 | 76篇 |
1982年 | 47篇 |
1980年 | 37篇 |
1979年 | 51篇 |
1977年 | 47篇 |
1973年 | 40篇 |
1972年 | 37篇 |
1971年 | 41篇 |
1969年 | 32篇 |
1968年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Tetsumori Yamashima Takaomi C. Saido Masatoshi Takita Atsuo Miyazawa Jun Yamano Atsuo Miyakawa Hisashi Nishijyo Junkoh Yamashita Seiichi Kawashima Taketoshi Ono Tohru Yoshioka 《The European journal of neuroscience》1996,8(9):1932-1944
To clarify the mechanism of postischaemic delayed cornu Ammonis (CA)-1 neuronal death, we studied correlations among calpain activation and its subcellular localization, the immunoreactivity of phosphatidylinositol 4,5-bisphosphate (PIP2) and Ca2+ mobilization in the monkey hippocampus by two independent experimental approaches: in vivo transient brain ischaemia and in vitro hypoxia-hypoglycaemia of hippocampal acute slices. The CA-1 sector undergoing 20 min of ischaemia in vivo showed microscopically a small number of neuronal deaths on day 1 and almost global neuronal loss on day 5 after ischaemia. Immediately after ischaemia, CA-1 neurons ultrastructurally showed vacuolation and/or disruption of the lysosomes. Western blotting using antibodies against inactivated or activated μ-calpain demonstrated μ-calpain activation specifically in the CA-1 sector immediately after ischaemia. This finding was confirmed in the perikarya of CA-1 neurons by immunohistochemistry. CA-1 neurons on day 1 showed sustained activation of μ-calpain, and increased immunostaining for inactivated and activated forms of μ- and m-calpains and for PIP2. Activated μ-calpain and PIP2 were found to be localized at the vacuolated lysosomal membrane or endoplasmic reticulum and mitochondrial membrane respectively, by immunoelectron microscopy. Calcium imaging data using hippocampal acute slices showed that hypoxia-hypoglycaemia in vitro provoked intense Ca2+ mobilization with increased PIP2 immunostaining specifically in CA-1 neurons. These data suggest that transient brain ischaemia increases intracellular Ca2+ and PIP2 breakdown, which will activate calpain proteolytic activity. Therefore, we suggest that activated calpain at the lysosomal membrane, with the possible release of biodegrading enzyme, will cause postischaemic CA-1 neuronal death. 相似文献
22.
Yutaka Yonemura Masataka Segawa Hisashi Matsumoto Kouichirou Tsugawa Itasu Ninomiya Luis Fonseca Takashi Fujimura Kazuo Sugiyama Kouichi Miwa Itsuo Miyazaki 《Surgery today》1994,24(6):488-493
Because gastric cancers located in the upper third of the stomach are difficult to detect at an early stage, the surgical results remain poor. We performed R4 gastrectomy as a radical procedure for 25 patients, involving complete resection of the latero-aortic and interaorticovenous lymph modes above and below the left renal vein, in combination with the ordinary R2 or R3 gastrectomy (the R4 group). These patients were compared with 156 others who underwent R2 gastrectomy alone (the R2 group). There were no significant differences in operation time, blood loss, or the incidence of complications between the two groups; however, when the survival rates of the patients with tumors invading beyond the subserosa were compared, the 5-year survival rate was found to be significantly higher in the R4 group than in the R2 group. Furthermore, in patients with para-aortic nodal involvement, a significant survival advantage was observed in the R4 group, as compared with the R2 group. These results suggest that the R4 gastrectomy is a rational approach for patients with advanced gastric cancer located in the upper third of the stomach. 相似文献
23.
Hisashi Ozasa 《Artificial organs》1994,18(10):768-770
Abstract: Extraction of adsorbed proteins from dialysis membranes that had been used during actual hemodialysis procedures was performed. The condition of extraction with SDS plus 2–mercaptoethanol at 95°C is more efficient than with only PBS or with SDS solution without 2–mercaptoethanol at 37°C. 相似文献
24.
International discussions concerning rhinomanometry have been held but no numerical comparisons have been reported. In an attempt to make international comparisons between different rhinomanometric results, nasal resistances were measured by active posterior rhinomanometry with a head-out body plethysmograph produced in Canada and by active posterior and anterior methods with a Japanese commercial rhinomanometer, and the results were compared. No significant differences were found between measurements obtained from the two types of equipment. It is believed that this study is the first project of international comparison of rhinomanometry. 相似文献
25.
N Taguchi N Matsumiya Y Ishizawa S Dohi H Naito 《Masui. The Japanese journal of anesthesiology》1992,41(2):251-254
Anesthesiologists often face the problem of a child with symptoms of an acute upper respiratory infection (URI) presenting for surgery. Anesthesia in the presence of uncomplicated URI may not be contraindicated. However, we experienced three cases of such children in which lung atelectasis developed after the induction of general anesthesia. Because continuous monitoring of arterial oxygen saturation by pulse oximetry (SpO2) was useful for detecting mild hypoxemia in these patients, we retrospectively examined the possible association between URI symptoms and SpO2 in 63 children. Patients with symptoms of URI showed a significantly high incidence of decreased SpO2 to below 95% for 5 minutes. Our results suggest that, with URI symptoms even uncomplicated, symptomatic patients have increased risks for the development of mild hypoxemia during anesthesia. 相似文献
26.
27.
Motohisa Kaneko M.D KO Watanabe M.D Hisashi Kumashiro M.D 《Psychiatry and clinical neurosciences》1992,46(3):711-720
Abstract: The plasma ratio of each neutral amino acid (tryptophan (TRP), tyrosine (TYR), valine, isoleucine, leucine (LEU) or phenylalanine) to the sum of the other neutral amino acids was measured in 16 : manic and 14 : depressed patients. In the manics, there was a correlation between the psychomotor activity and the plasma TRP and LEU ratios. In the depressives, the depressed mood, retardation and global severity were correlated with the TRP ratio. The zotepine responders showed an increase in the TRP ratio after treatment. In the mianserin responders, the TYR ratio, which was high before the treatment, decreased to the normal range after the treatment. But, the plasma amino acid ratios remained unchanged in the patients treated with lithium carbonate or amitriptyhe. These results suggest that, in manic-depressive illness, there might be abnormalities in the metabolism of neutral amino acids, mainly of TRP and TYR, and that the plasma TRP and TYR ratios might be important indicators for determining the efflcacy of some drugs. 相似文献
28.
Hiroyoshi Komai Yasuaki Naito Keiichi Fujiwara Yasuzo Noguchi 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2002,50(2):55-58
OBJECTIVE: Since we developed the procedure in 1996, we have now performed 100 pediatric open heart operations using a lower midline skin incision and a minimal sternotomy approach. METHODS AND RESULTS: To elucidate the benefits of this approach, we analyzed these 100 cases retrospectively. There was no death, and no major complication, caused by this approach, and the resulting scarring in each patient is difficult to be seen under a common undershirt. CONCLUSION: This review shows that the technique of a lower midline skin incision and minimal sternotomy approach is a safe reliable and cosmetically advantageous method for a pediatric cardiac operation. 相似文献
29.
Genetic alteration in carcinoid tumors of the lung. 总被引:1,自引:0,他引:1
Kenji Sugio Toshihiro Osaki Tsunehiro Oyama Mitsuhiro Takenoyama Takeshi Hanagiri Masaru Morita Koji Yamazaki Akira Nagashima Hisashi Nakahashi Yoshihiko Maehara Kosei Yasumoto 《Annals of thoracic and cardiovascular surgery》2003,9(3):149-154
Surgically resected specimens of 13 carcinoid tumors of the lung including nine typical carcinoids and four atypical carcinoids, and eight salivary gland type carcinomas (six mucoepidermoid carcinomas and two adenoid cystic carcinomas) were analyzed regarding p53 expression, loss of heterozygosity (LOH) in chromosome 3p, 9p, and K-ras mutation. The overexpression of p53 was identified in four atypical carcinoid tumors, one mucoepidermoid carcinoma, and one adenoid cystic carcinoma, however, none of typical carcinoids showed p53 immunoreactivity. LOH in 3p14 was demonstrated in three of seven informative cases in all tumors. LOH in 9p was demonstrated in two of five informative cases in all tumors. Two of three cases with LOH at 3p14 had a poor prognosis, one of which also had LOH at 9p. No mutation of the K-ras gene was observed in any of these tumors. These data thus indicate that p53 overexpression might distinguish atypical carcinoid tumors from typical tumors and might therefore be useful as an adjunct modality in the differential diagnosis of pulmonary carcinoid tumors. The presence of LOH at 3p14 or 9p may thus help to identify lung cancer patients with a poor prognosis. 相似文献
30.