全文获取类型
收费全文 | 22088篇 |
免费 | 1024篇 |
国内免费 | 129篇 |
专业分类
耳鼻咽喉 | 186篇 |
儿科学 | 513篇 |
妇产科学 | 233篇 |
基础医学 | 2677篇 |
口腔科学 | 503篇 |
临床医学 | 1444篇 |
内科学 | 5639篇 |
皮肤病学 | 301篇 |
神经病学 | 1577篇 |
特种医学 | 927篇 |
外科学 | 4493篇 |
综合类 | 99篇 |
一般理论 | 1篇 |
预防医学 | 643篇 |
眼科学 | 463篇 |
药学 | 1307篇 |
中国医学 | 30篇 |
肿瘤学 | 2205篇 |
出版年
2023年 | 128篇 |
2022年 | 279篇 |
2021年 | 484篇 |
2020年 | 260篇 |
2019年 | 325篇 |
2018年 | 406篇 |
2017年 | 342篇 |
2016年 | 388篇 |
2015年 | 421篇 |
2014年 | 551篇 |
2013年 | 684篇 |
2012年 | 1137篇 |
2011年 | 1173篇 |
2010年 | 648篇 |
2009年 | 593篇 |
2008年 | 1040篇 |
2007年 | 1181篇 |
2006年 | 1151篇 |
2005年 | 1159篇 |
2004年 | 1107篇 |
2003年 | 1124篇 |
2002年 | 1081篇 |
2001年 | 585篇 |
2000年 | 611篇 |
1999年 | 557篇 |
1998年 | 369篇 |
1997年 | 240篇 |
1996年 | 229篇 |
1995年 | 187篇 |
1994年 | 173篇 |
1993年 | 145篇 |
1992年 | 390篇 |
1991年 | 391篇 |
1990年 | 346篇 |
1989年 | 344篇 |
1988年 | 323篇 |
1987年 | 321篇 |
1986年 | 285篇 |
1985年 | 273篇 |
1984年 | 166篇 |
1983年 | 179篇 |
1982年 | 96篇 |
1979年 | 149篇 |
1978年 | 85篇 |
1977年 | 92篇 |
1975年 | 96篇 |
1974年 | 94篇 |
1973年 | 112篇 |
1972年 | 94篇 |
1971年 | 84篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Katsunobu Kawahara Shinji Akamine Takao Takahashi Akihiro Nakamura Hiroyuki Kusano Tohru Nakagoe Takayuki Nakazaki Hiroyoshi Ayabe Masao Tomita 《Surgery today》1994,24(12):1101-1103
We report herein the case of a 75-year-old man who developed anal canal metastasis from squamous cell carcinoma of the lung. Initially, he underwent a right middle and lower lobectomy combined with left atrial wall resection under cardiopulmonary bypass. He presented 3 months later with an anal polyp which had prolapsed and bled, for which he underwent a transanal polypectomy. Histologically, the polyp was classified as squamous cell carcinoma and considered to be a metastasis from the primary lung cancer. He is presently well with no signs of recurrence 9 months after his initial operation. To our knowledge, there has been no other case of anal metastasis from lung cancer ever reported. 相似文献
92.
To clarify the circadian aspects of delayed sleep phase syndrome (DSPS) in 4 patients with DSPS, we recorded polysomnograms and rectal temperature before and after chronotherapy. The time interval (2.7 h) between sleep onset and rectal temperature minimum before chronotherapy was shorter than the time interval after chronotherapy (5.3 h). Before chronotherapy, the period of rectal temperature rhythm was 24.7 h. After chronotherapy, the period of rectal temperature rhythm was 24.0 h. These findings lead to the conclusion that in DSPS there is a weakened mechanism of entrainment similar to that in non-24-hour sleep-wake syndrome. 相似文献
93.
Estrone and estradiol-17 beta concentration in breast cancer tissue are reported to be an order of magnitude higher than those of circulating plasma in breast cancer patients. This high level of estrogen is provided by local production from estrone sulfate (E1-S) through the sulfatase pathway. Then serum E1-S level was determined using direct radioimmunoassay method in order to monitor the estrogen kinetics of post-operative breast cancer patients. Peri-operative sequential E1-S determination was carried out in 10 patients. Among them, extremely higher level, as compared with normal menstruating level of 625-2670pg/ml, was observed just after an administration of tamoxifen (three weeks after operation) in two of 5 pre-menopausal patients. In order to evaluate the effect of tamoxifen on serum level of E1-S in post-operative pre-menopausal patients, serum E1-S level in 42 post-operative outpatients was examined. Although there was no difference in the average level of E1-S in post-menopausal patients treated with or without tamoxifen, average E1-S level in pre-menopausal patients treated with tamoxifen as adjuvant therapy was significantly higher than that in patients without tamoxifen. These results suggests that the administration of tamoxifen to premenopausal patients should be reconsidered from a view point of the estrogen kinetics. 相似文献
94.
95.
M Uchida T Fujiwara T Wada S Nakajima H Sato Y Nakata H Yamaguchi S Kawai R Okada T Kano 《Journal of cardiology》1988,18(4):1043-1050
The effect of hypertension on asymmetrical septal hypertrophy was studied by echocardiography to differentiate idiopathic asymmetrical septal hypertrophy (ASH) from ASH with hypertension. One hundred eight patients with ASH proven by echocardiography were categorized in two groups; 53 patients with hypertension (greater than 160 systolic, greater than 95 diastolic) (hypertensive group: HT) and 55 patients with normal blood pressure (normotensive group: NT). Septal hypertrophy was classified as mid-portion (M-type), diffuse (D-type), and basal (B-type) hypertrophy by the long-axis view, and also diffuse (I-type), anterolateral (II-type), anteroseptal (III-type), and anterior septal (IV-type) by the short-axis view, respectively. Endomyocardial biopsy and left ventriculography were performed in 50 patients (18 hypertensives and 32 normotensives). In the hypertensive group, 45%, 30%, and 25% of cases had diffuse, basal and mid-portion hypertrophy, respectively. There was no case in the basal hypertrophy whose biopsy findings were compatible with hypertrophic cardiomyopathy. In the normotensive group, 78% and 22% of patients had midportion and diffuse hypertrophy, respectively, but none of them had the basal hypertrophy. Type IV was seen in only six patients in the normotensive group. 相似文献
96.
Hiroyoshi Matsukura M.D. Akira Higuchi M.D. Yoshifumi Suzuki M.D. Toshio Okada M.D. 《Pediatrics international》1987,29(2):277-279
A patient presenting with osteomyelitis of the pelvis is described. In this case it was difficult to establish a correct diagnosis by use of scintigraphic scanning, in spite of clear roentgenographic evidence of osteomyelitis. 相似文献
97.
High incidence of multiple kidney stone formation has been observed among workers exposed to cadmium (Cd). Citrate is known to be a protective factor against renal stone formation. To study the direct effect of cadmium on citrate uptake by the renal brush border membrane, we exposed isolated rat renal brush border membrane vesicles (BBMV) to cadmium and determined their citrate uptake characteristics. BBMV were prepared by the divalent cation precipitation method. Citrate uptake was measured by the Millipore rapid membrane filtration technique. Preincubation of BBMV with 2 and 10 mM CdCl2 for 1 min significantly inhibited citrate uptake compared with that of BBMV without Cd. Analysis of the time course of citrate uptake during 30-min preincubation of BBMV with 0.5 mM Cd also revealed significant reduction of the uptake compared with that of the control BBMV without preincubation. These findings indicate that preincubation of BBMV with cadmium results in time-dependent and concentration-dependent inhibition of citrate uptake. 相似文献
98.
Hiroo Takehara M.D. Akira Okada M.D. Masaharu Nishi M.D. Katsuhiro Masamune M.D. 《Pediatrics international》1992,34(5):569-572
We present a case of Peutz-Jegher's syndrome in an 18 year old female who was followed for gastrointestinal polyps for 13 years from the age of 5 years. The patient was treated four times with surgical or endoscopic polypectomy for gastrointestinal polyps. At the age of 14 years, a combined surgical and endoscopic approach for the management of Peutz-Jegher's syndrome was carried out. A large polyp of the ileum required enterotomy for its removal, and another smaller polyp of the upper jejunum was identified and removed by intra-operative total enteroscopy via the anus. Intra-operative enteroscopy allows one to identify polyps that would previously have been missed. A more complete polypectomy can be performed using this technique, allowing the patient with Peutz-Jegher's syndrome a longer interval between laparotomies and a reduction in symptoms attributed to polyps. 相似文献
99.
Takuya Watanabe Keiko Takahashi Tomoko Kanome Shigeki Hongo Akira Miyazaki Shinji Koba Takashi Katagiri Rajbabu Pakara Claude R Benedict 《Hypertension research》2006,29(10):821-831
Human urotensin-II (U-II) is the most potent vasoactive peptide identified to date, and may be involved in hypertension and atherosclerosis. We investigated the effects of the interactions between U-II or other vasoactive agents and mildly oxidized low-density lipoprotein (mox-LDL) or hydrogen peroxide (H2O2) on the induction of vascular smooth muscle cell (VSMC) proliferation. Growth-arrested rabbit VSMCs were incubated with vasoactive agents (U-II, endothelin-1, angiotensin-II, serotonin, or thromboxane-A2) in the presence or absence of mox-LDL or H2O2. [3H]Thymidine incorporation into DNA was measured as an index of VSMC proliferation. On interaction with mox-LDL or H2O2, U-II induced the greatest increase in [3H]thymidine incorporation among these vasoactive agents. A low concentration of U-II (10 nmol/l) enhanced the potential mitogenic effect of low concentrations of mox-LDL (120 to 337%) and H2O2 (177 to 226%). U-II at 50 nmol/l showed the maximal mitogenic effect (161%), which was abolished by G protein inactivator (GDP-beta-S), c-Src tyrosine kinase inhibitor (radicicol), protein kinase C (PKC) inhibitor (Ro31-8220), extracellular signal-regulated kinase (ERK) kinase inhibitor (PD98059), or Rho kinase inhibitor (Y27632). Mox-LDL at 5 microg/ml showed the maximal mitogenic effect (211%), which was inhibited by free radical scavenger (catalase), intracellular and extracellular antioxidants (N-acetylcysteine and probucol), nicotinamide adenine dinucleotide phosphate oxidase inhibitor (diphenylene iodonium), or c-Jun N-terminal kinase (JNK) inhibitor (SP600125). These results suggested that U-II acts in synergy with mox-LDL in inducing VSMC DNA synthesis at the highest rate among these vasoactive agents. Activation of the G protein/c-Src/PKC/ERK and Rho kinase pathways by U-II together with the redox-sensitive JNK pathway by mox-LDL may explain the synergistic interaction between these agents. 相似文献
100.
Shinji Homma Kenji Satoh Hitoshi Matsuo Minoru Yagi Jun Hasegawa Tomoyuki Maruta Naozumi Watanabe Tsuneo Iiai Katsuyoshi Hatakeyama 《Journal of Smooth Muscle Research》2004,40(6):271-280
Electrogastrograms (EGGs) were recorded in patients both before and after receiving proximal gastrectomy plus jejunal interposition (PGJI) or just after receiving total gastrectomy plus jejunal interposition (TGJI). Intraluminal pressure was also recorded in some postoperative patients. The EGG 3 cpm component (2.5-4.9 cpm) remained after PGJI, but subsequently decreased with a significant reduction in the preoperative to postoperative ratio of the 3 cpm components (P<0.05). The mean frequency of the 3 cpm components increased significantly after PGJI (P<0.05) and its instability factor increased. The EGG 10 cpm components became relatively dominant compared to other frequency components in 2 out of 8 of patients having PGJI but the mean amplitude of 10 cpm decreased. In TGJI patients, only the 10 cpm component was conspicuous in EGG as in the case of total gastrectomy and Roux en Y anastomosis procedures. The spectral frequencies of intraluminal pressure in the interposed jejunum were similar to the EGG of 10 cpm components both in the case of PGJI and TGJI patients. In conclusion, surface EGG could record the electrical activities of the interposed jejunum more easily in patients having had TGJI than in PGJI. 相似文献