全文获取类型
收费全文 | 55343篇 |
免费 | 2589篇 |
国内免费 | 346篇 |
专业分类
耳鼻咽喉 | 806篇 |
儿科学 | 950篇 |
妇产科学 | 856篇 |
基础医学 | 6976篇 |
口腔科学 | 1448篇 |
临床医学 | 3705篇 |
内科学 | 14266篇 |
皮肤病学 | 895篇 |
神经病学 | 4255篇 |
特种医学 | 1892篇 |
外科学 | 9496篇 |
综合类 | 233篇 |
一般理论 | 5篇 |
预防医学 | 1759篇 |
眼科学 | 1035篇 |
药学 | 4216篇 |
中国医学 | 112篇 |
肿瘤学 | 5373篇 |
出版年
2023年 | 325篇 |
2022年 | 658篇 |
2021年 | 1172篇 |
2020年 | 625篇 |
2019年 | 853篇 |
2018年 | 972篇 |
2017年 | 757篇 |
2016年 | 930篇 |
2015年 | 993篇 |
2014年 | 1321篇 |
2013年 | 1660篇 |
2012年 | 2741篇 |
2011年 | 2959篇 |
2010年 | 1715篇 |
2009年 | 1391篇 |
2008年 | 2602篇 |
2007年 | 2917篇 |
2006年 | 2768篇 |
2005年 | 2740篇 |
2004年 | 2612篇 |
2003年 | 2588篇 |
2002年 | 2555篇 |
2001年 | 1757篇 |
2000年 | 1880篇 |
1999年 | 1622篇 |
1998年 | 645篇 |
1997年 | 550篇 |
1996年 | 498篇 |
1995年 | 402篇 |
1994年 | 372篇 |
1993年 | 335篇 |
1992年 | 1160篇 |
1991年 | 965篇 |
1990年 | 945篇 |
1989年 | 984篇 |
1988年 | 853篇 |
1987年 | 855篇 |
1986年 | 797篇 |
1985年 | 784篇 |
1984年 | 548篇 |
1983年 | 435篇 |
1982年 | 233篇 |
1979年 | 489篇 |
1978年 | 277篇 |
1977年 | 259篇 |
1975年 | 211篇 |
1974年 | 228篇 |
1971年 | 234篇 |
1969年 | 233篇 |
1968年 | 219篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Naohito Mikuma Hideki Adachi Keiji Takatsuka Akifumi Yokoo Hideki Wada Atsushi Takahashi 《International journal of urology》1996,3(3):243-244
A rare adult case of a left ectopic ureterocele associated with a duplex horseshoe kidney is reported. To the best of our knowledge, only one pediatric case of horseshoe kidney with an ectopic ureterocele has been reported. The present case was successfully treated by ureteropyelostomy, upper ureterectomy and unroofing of the ureterocele. The patient is currently followed with excretory urograms and renograms. 相似文献
132.
133.
Chromosomal Mapping of Genetic Locus Associated with Thymus-size Enlargement in BUF/Mna Rats 总被引:2,自引:1,他引:1
Yoshiki Murakumo Masahide Takahashi Atsushi Arakawa Mitsuhiro Saito Hiroyuki Amo Hideki Katoh Mutsushi Matsuyama 《Cancer science》1993,84(8):838-840
The thymoma-prone rat of the BUF/Mna strain is a useful model for human thymoma. In this strain thymoma development is regulated by a single autosomal susceptible gene, Tsr-1. At pre-thymoma age, BUF/Mna rats have extremely large thyrauses, when compared to those of other strains of rats. Genetic studies in crosses between BUF/Mna rats with large thymuses and WKY/NCrj rats with small thymuses suggested the presence of a major autosomal gene, Ten-1 , which contributes to thymus enlargement in a backcross population. Linkage studies between Ten-1 and microsatellite markers in backcross rats of (WKY/NCrj×BUF/Mna)Fl×BUF/Mna have led to the localization of Ten-1 in chromosome 1. This result may provide an approach to clone Tsr-1 , which could be allelic to Ten-1. 相似文献
134.
The enzyme activities, which are influenced by the vitamin C level in tissues, were measured to evaluate the vitamin C activity of erythorbic acid (ErA) in guinea pigs administered ErA. Guinea pigs were divided into two groups: animals in one group (control group) were administered 1, 5, and 100 mg/day ascorbic acid (AsA) and those in the other group (supplemented group) were administered 1, 5, 20, and 100 mg/day ErA for 16 days. At the end of the experimental period, they were sacrificed, blood was collected, and their livers were removed. The activities of liver aniline hydroxylase, of liver acid phosphatase, and of serum alkaline phosphatase, and the content of liver cytochrome P-450 were assayed. The activities of aniline hydroxylase and serum alkaline phosphatase and the content of liver cytochrome P-450 of the guinea pigs administered 1 mg ErA were lower than those of the guinea pigs administered 1 mg AsA. However, the enzyme activities and liver cytochrome P-450 content in the guinea pigs administered 5 mg or more of ErA were similar in level to those in the guinea pigs administered 5 mg AsA. These results suggested that administration of a considerably high amount of ErA to guinea pigs showed a similar vitamin C activity to that of AsA, which might suggest that vitamin C activity of ErA may be more than one-twentieth that of AsA, as has been generally believed. 相似文献
135.
High Cell-Density Culture System of Hepatocytes Entrapped in a Three-Dimensional Hollow Fiber Module with Collagen Gel 总被引:2,自引:0,他引:2
Kazuyoshi Takeshita Haruaki Ishibashi Masayuki Suzuki Takumi Yamamoto Toshihiro Akaike Masashi Kodama 《Artificial organs》1995,19(2):191-193
Abstract: A compact three-dimensional (3D) module is needed for hepatocyte culture in order to develop an effective hybrid artificial liver system that can retain hepa-tocellular structure and differentiated functions. We treated the 3D module with collagen gel to entrap rat hepatocytes. This method yielded a high hepatocellular density (2 times 107 cells/ml) over a period of 14 days and maintained the secretion of albumin and ureogenesis at the same level as the control monolayer method. The ammonia removal remained at 43% of the Day 0 value over 8 days of perfusion. Our data show that this approach may be useful for liver support therapy in an ex-tracorporeal circuit. 相似文献
136.
The effects of intraperitoneal
and
methyl ester, specific inhibitors of nitric oxide (NO) synthase, were examined on the pentylenetetrazol (PTZ)-induced seizures in rats. The incidence and latency for the onset of myoclonic jerks, clonic seizures, and tonic generalized extension were observed as specific parameters among PTZ-induced seizures. Both drugs preferentially suppressed the tonic generalized extension and prolonged the latency for the onset of each parameter, suggesting NO has a significant effect on the PTZ-induced seizure. 相似文献
137.
Isao Sekiguchi M.D. Mitsuaki Suzuki M.D. Ikuo Sato M.D. Taeko Ohkawa M.D. Hidetoshi Kawashima M.D. Syuichi Tsuchida M.D. 《Gynecologic oncology》1998,71(3):454-457
We present the fourth known case of endometrial carcinoma, and the second case of endometrial small-cell carcinoma, to be associated with paraneoplastic retinopathy. Initial symptoms were decreased visual acuity and a narrowing of the visual field. Endometrial carcinoma was diagnosed several months later. An antibody to 34-kDa bovine retinal antigen was detected in the patient's serum. Thus, autoimmunity was suspected as the cause of the retinopathy. In patients with endometrial carcinoma with visual disturbance of unknown cause, paraneoplastic retinopathy should be suspected. 相似文献
138.
T Nishiura K Suzuki T Kawaguchi H Nakao N Kawamura M Taniguchi Y Kanayama T Yonezawa S Iizuka N Taniguchi 《Cancer letters》1992,62(3):211-215
We measured the serum levels of manganese-superoxide dismutase (Mn-SOD) in acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL). Serum Mn-SOD level for normal subjects was 94.1 +/- 23.5 ng/ml (mean +/- S.D.), the levels for AML and ALL patients were 159.6 +/- 77.1 ng/ml and 154.4 +/- 77.0 ng/ml, respectively. The serum Mn-SOD levels were unrelated to individual intracellular Mn-SOD levels, but correlated well with serum lactate dehydrogenase values. Regression of the leukemia was accompanied by decrease in the serum level of Mn-SOD. Serum Mn-SOD may thus serve as a measure of the activity of the disease. 相似文献
139.
140.
Atsushi Yokota Munekazu Doi Hisashi Ohtsuka Muneaki Abe 《Journal of orthopaedic research》2003,21(1):36-43
To clarify how the peripheral nerve adapts to elongation during gradual limb lengthening, electrophysiological and histomorphometric examinations were performed on the sciatic nerves in 18 rabbits. External fixators were used to lengthen the right femora by 30 mm (30%), at a daily rate of 0.5 mm (Group 1) or 2.0 mm (Group 2). Examinations were performed immediately after the limb lengthening procedure. Electrophysiologically, mild conduction slowing was observed in Group 1; a conduction block was evident in Group 2. Histologically, the mean diameter of myelinated fibers was unchanged in Group 1, but a significantly decreased diameter was observed in Group 2. Electron microscopy revealed that mild degenerative change of unmyelinated axons occurred sporadically in two cases in Group 2, but neither group showed evidence of thinning of myelin sheath of myelinated fibers. The mean internodal length (between nodes of Ranvier) of teased fibers was 1216+/-295 microm in the control contralateral side, 1484+/-347 microm in Group 1, and 1467+/-322 microm in Group 2. Thus the internodes were lengthened by 22.1% (Group 1) and 20.7% (Group 2) in comparison with those of the controls. Straightening of the geometry of paranodal myelin sheath was significantly correlated with the rate of distraction. These results indicate that myelinated nerve fibers adapt to gradual elongation by lengthening each Schwann cell body, not by proliferation of Schwann cells. 相似文献