全文获取类型
收费全文 | 4226篇 |
免费 | 207篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 52篇 |
妇产科学 | 45篇 |
基础医学 | 534篇 |
口腔科学 | 157篇 |
临床医学 | 247篇 |
内科学 | 1093篇 |
皮肤病学 | 113篇 |
神经病学 | 432篇 |
特种医学 | 141篇 |
外科学 | 519篇 |
综合类 | 25篇 |
预防医学 | 185篇 |
眼科学 | 95篇 |
药学 | 280篇 |
中国医学 | 6篇 |
肿瘤学 | 519篇 |
出版年
2023年 | 31篇 |
2022年 | 55篇 |
2021年 | 98篇 |
2020年 | 62篇 |
2019年 | 65篇 |
2018年 | 111篇 |
2017年 | 78篇 |
2016年 | 89篇 |
2015年 | 98篇 |
2014年 | 121篇 |
2013年 | 156篇 |
2012年 | 246篇 |
2011年 | 297篇 |
2010年 | 158篇 |
2009年 | 110篇 |
2008年 | 194篇 |
2007年 | 205篇 |
2006年 | 215篇 |
2005年 | 181篇 |
2004年 | 199篇 |
2003年 | 157篇 |
2002年 | 166篇 |
2001年 | 101篇 |
2000年 | 144篇 |
1999年 | 101篇 |
1998年 | 49篇 |
1997年 | 48篇 |
1996年 | 49篇 |
1995年 | 36篇 |
1994年 | 43篇 |
1993年 | 24篇 |
1992年 | 67篇 |
1991年 | 60篇 |
1990年 | 53篇 |
1989年 | 58篇 |
1988年 | 53篇 |
1987年 | 46篇 |
1986年 | 40篇 |
1985年 | 63篇 |
1984年 | 38篇 |
1983年 | 27篇 |
1981年 | 18篇 |
1980年 | 25篇 |
1979年 | 19篇 |
1978年 | 18篇 |
1974年 | 16篇 |
1973年 | 18篇 |
1971年 | 16篇 |
1970年 | 16篇 |
1969年 | 18篇 |
排序方式: 共有4457条查询结果,搜索用时 15 毫秒
41.
A microsomal fraction was obtained from the zona glomerulosa of the bovine adrenal cortex. Glucose-6-phosphate activity of the fraction was found to be much lower than that of the liver. Contents of RNA and phospholipids, besides electron microscopic findings, of the fraction also indicate that it is rich in smooth-surfaced endoplasmic reticulum. Distribution of cytochrome P-450 in the zona glomerulosa was studied using various fractions including the microsomal fraction described above. The amount of cytochrome P-450 in mitochondria and that in microsomes were determined to be 0.73 and 0.32 nmoles/mg protein, respectively. The CO-difference spectrum was affected not only by the concentration of added deoxycholate but also by the incubation time after addition. Approximately 40-50% of cytochrome P-450 in the samples were converted to cytochrome P-420 within 20-30 seconds of incubation with deoxycholate. 相似文献
42.
43.
The incidence and clinicopathologic features of unilateral multicentric breast cancer (UMBC) were studied by mammary gland
serial sectioning in 116 cases of clinically defined monocentric breast cancer (MONBC) examined histopathologically at the
Nagano Cancer Detection Center. UMBC was defined as: 1) histopathologically discontinuous tumors each with an intraductal
spread, 2) at least one tumor-free section separating two tumors, and 3) a large primary tumor and other small secondary tumors.
UMBC was detected in 23 of 116 cases (19.8%), all with one secondary tumor. Primary and secondary tumors were located in the
same quadrant in 34.8% and in different ones in 65.2%. The secondary tumors were <5 mm in size in 56.5%. Secondary tumors,
averaging 8.3 mm in size and 25.5 mm in distance from the primary tumor, were almost exclusively noninvasive carcinomas, including
15 (65.4%) noninvasive ductal carcinomas and several special types. The primary and secondary tumors were of the same histologic
type in 3 of 23 cases. UMBC patients averaged 6 years younger than MONBC patients, and the incidence of UMBC tended to be
higher in younger patients (p<0.1). UMBC tended to occur more frequently in quadrant with an average histologie tumor size
significantly smaller than that in MONBC (p<0.01). The histologie types of the primary tumor in UMBC and MONBC were similar,
with common types predominant. Lymph node metastases tended to be slightly more frequent in MONBC.
This high incidence of UMBC calls for careful attention when considering breast conserving therapy. 相似文献
44.
Iwanaga K Wakabayashi K Yoshimoto M Tomita I Satoh H Takashima H Satoh A Seto M Tsujihata M Takahashi H 《Neurology》1999,52(6):1269-1271
Heart tissues of patients with PD or incidental Lewy body (LB) disease (ILBD) were examined by light and electron microscopy. LBs and alpha-synuclein-positive neurites were identified in the hearts from 9 of 11 patients with PD and from 7 of 7 patients with ILBD. LBs were present in both tyrosine hydroxylase-positive and -negative nerve processes, which are nerves of extrinsic sympathetic and intrinsic origin, respectively. These findings provide histologic evidence that the postganglionic sympathetic and intrinsic neurons in the heart are involved in the PD disease process. 相似文献
45.
Microsomal Cytochrome P-450 Monooxygenase System and Its Drug-metabolizing Activity after Partial Portal Vein Ligation in the Rat 总被引:1,自引:0,他引:1
Kunihiko Izuishi Hisao Wakabayashi Yasutaka Kokudo Takashi Maeba Munemasa Ryu Hajime Maeta 《World journal of surgery》1999,23(1):6-11
RID=" ID=" <E5>Correspondence to:</E5> K. Izuishi, M.D. 相似文献
46.
Impaired glucose tolerance, diabetes mellitus, and gallstone disease: An extended study of male self-defense officials in Japan 总被引:2,自引:0,他引:2
Shizuka Sasazuki Suminori Kono Isao Todoroki Satoshi Honjo Yutaka Sakurai Kazuo Wakabayashi Masato Nishiwaki Hiroaki Hamada Hiroshi Nishikawa Hiroko Koga Shinsaku Ogawa Katsuya Nakagawa 《European journal of epidemiology》1999,15(3):245-251
Few studies have investigated the relation between glucose tolerance status and ultrasonographically determined gallstone disease. Using a 75-g oral glucose tolerance test, we examined the association of impaired glucose tolerance (IGT) and non-insulin-dependent diabetes mellitus (NIDDM) with gallstone disease in Japanese men. Subjects were men aged 48 to 59 of the Japan Self-Defense Forces who received a preretirement health examination between October 1986 to December 1994. After exclusion of 12 men under insulin treatment in the consecutive series of 7637 men, 174 were found to have gallstones; 103 were at the state of postcholecystectomy, and 6899 had normal gallbladder. IGT and NIDDM were associated with a modestly increased risk of gallstone disease; adjusted odds ratios were 1.3 (95% confidence interval [CI]: 0.9–1.8) for IGT and 1.3 (95% CI: 0.8–2.0) for NIDDM after adjustment for hospital, rank, smoking, alcohol use, and body mass index. Adjusted odds ratio for IGT and NIDDM combined was 1.3 (95% CI: 1.0–1.7, p=0.08). When prevalent gallstones and postcholecystectomy were considered separately, NIDDM showed a significant, positive association with postcholecystectomy, but not with prevalent gallstones. The findings add to evidence that glucose intolerance is associated with a modest increase in the risk of gallstone disease. 相似文献
47.
M Z Quan J Kosaka M Watanabe T Wakabayashi Y Fukuda 《Investigative ophthalmology & visual science》1999,40(10):2360-2366
PURPOSE: Peripheral nerve (PN) grafting to the optic nerve stump stimulates not only axonal regeneration of the axotomized retinal ganglion cells (RGCs) into the grafted PN but also their survival. The purpose of the present study was to determine the number, distribution, and soma diameter of only surviving RGCs without regenerated axons and surviving RGCs with regenerated axons in PN-grafted mammals. METHODS: A segment of PN was grafted to the optic nerve stump of adult ferrets. Two months after the PN grafting, surviving RGCs with regenerated axons were retrogradely labeled with granular blue (GB) and stained with RGC-specific antibody C38. Surviving RGCs without regenerated axons were identified as C38-positive cells without GB labeling. RESULTS: Twenty-one percent of RGCs survived axotomy after PN grafting in the area centralis (AC), whereas 47% survived in the peripheral retina. Twenty-six percent of surviving RGCs in the AC exhibited axonal regeneration, which was higher than that in the peripheral retina. Soma diameter histograms revealed that RGCs with regenerated axons showing both GB and C38 positivity were in the large soma diameter ranges. In contrast, the soma diameter distribution of surviving RGCs that did not have regenerated axons showed a peak in the smaller soma diameter ranges. CONCLUSIONS: The present data suggest that PN grafting promotes survival of axotomized RGCs more effectively in the peripheral retina than in the AC. Among surviving RGCs, the larger cells exhibited axonal regeneration into the grafted PN, whereas the axons of smaller cells did not to regenerate in either the AC or the peripheral retina. 相似文献
48.
A 45-year-old male presented with spontaneous dissecting aneurysm in the anterior cerebral artery manifesting as headache persisting for several days and speech disturbance. Neurological and laboratory examinations showed no abnormalities. Magnetic resonance imaging revealed infarction in the right cingulate gyrus. Angiography revealed occlusion of the right A2. Repeat angiography 8 months later showed a saccular aneurysm had developed. The interhemispheric approach exposed the aneurysm at the junction between the right frontopolar artery and the pericallosal artery. The aneurysm was fusiform due to the right A2 dissection. The aneurysm was trapped and resected. One month after the operation, the patient was discharged without neurological deficits. Cases of dissecting aneurysms in the anterior cerebral artery with ischemic onset are usually treated conservatively. Cases requiring surgery include those due to trauma, growing aneurysms, giant aneurysms, and uncontrolled hypertension. Some dissecting aneurysms of the distal anterior cerebral artery require only resection without bypass surgery. 相似文献
49.
Kubo K Umemoto T Shirahashi K Wakabayashi M Imaizumi M Furuhashi K Kitoh Y 《Nihon Geka Gakkai zasshi》2000,101(10):741-744
We had surgically treated varicose veins in 554 legs of 386 patients as of June 30, 2000. Varicose veins of the stem or segment type without skin changes were treated with sclerotherapy combined with high ligation, while a part of secondary varicose veins and the reticular or web type were treated with sclerotherapy alone. This paper describes our methods for day surgery for this condition. The most important therapeutic consideration in the surgical procedure is achieving sufficient venous collapse to prevent the occurrence of intravenous thrombus. In our 386 patients, a massive intravenous thrombus that was resected occurred in one limb (0.1%). Postoperative bleeding also occurred in one limb (0.1%) of a patient with severe liver cirrhosis. 相似文献
50.
Taro Semba Yasuhiro Funahashi Naoto Ono Yuji Yamamoto Naoko Hata Sugi Makoto Asada Kentaro Yoshimatsu Toshiaki Wakabayashi 《Clinical cancer research》2004,10(4):1430-1438
We reported previously that an angiogenesis inhibitor, E7820, inhibits in vitro tube formation of human umbilical vein endothelial cell through the suppression of integrin alpha2 expression. Here we describe the antiangiogenic and antitumor effects of E7820 in mice and discuss the feasibility of using platelet integrin alpha2 expression on platelets as a biological marker of the efficacy of E7820. Oral administration of E7820 significantly inhibited basic fibroblast growth factor-induced angiogenesis in Matrigel implants and human colon WiDr tumor-induced angiogenesis in a dorsal air sac model. Twice-daily treatment with E7820 clearly inhibited the s.c. tumor growth of seven tumor cell lines derived from human colon, breast, pancreas, and kidney, and completely suppressed the growth of human pancreatic KP-1 and human colon LoVo cell lines. Moreover, E7820 significantly inhibited the growth of KP-1 and human colon tumor Colo320DM cells orthotopically implanted in the pancreas and cecum, respectively. The efficacy of E7820 was comparable in the s.c. and orthotopic transplantation models. Immunohistochemical analyses using anti-CD31 antibody showed that E7820 significantly reduced microvessel density in orthotopically implanted KP-1 tumor. E7820 reduced integrin alpha2 expression on a megakaryocytic cell line, Dami cells, induced by phorbol 12-myristate 13-acetate treatment. It also decreased the expression level of integrin alpha2 on platelets withdrawn from mice bearing s.c. KP-1 tumor at a dosage close to that affording antitumor activity. These data demonstrate that E7820 showed a broad-spectrum antitumor effect in mice through inhibition of angiogenesis and indicate that the decrease of integrin alpha2 on platelets might serve as a biological marker for the antitumor efficacy of E7820. 相似文献