全文获取类型
收费全文 | 14110篇 |
免费 | 610篇 |
国内免费 | 87篇 |
专业分类
耳鼻咽喉 | 121篇 |
儿科学 | 267篇 |
妇产科学 | 239篇 |
基础医学 | 1847篇 |
口腔科学 | 261篇 |
临床医学 | 938篇 |
内科学 | 3399篇 |
皮肤病学 | 300篇 |
神经病学 | 943篇 |
特种医学 | 575篇 |
外科学 | 2344篇 |
综合类 | 99篇 |
一般理论 | 2篇 |
预防医学 | 393篇 |
眼科学 | 249篇 |
药学 | 849篇 |
中国医学 | 32篇 |
肿瘤学 | 1949篇 |
出版年
2023年 | 74篇 |
2022年 | 107篇 |
2021年 | 265篇 |
2020年 | 141篇 |
2019年 | 191篇 |
2018年 | 236篇 |
2017年 | 206篇 |
2016年 | 240篇 |
2015年 | 275篇 |
2014年 | 372篇 |
2013年 | 469篇 |
2012年 | 738篇 |
2011年 | 851篇 |
2010年 | 446篇 |
2009年 | 408篇 |
2008年 | 734篇 |
2007年 | 803篇 |
2006年 | 756篇 |
2005年 | 758篇 |
2004年 | 703篇 |
2003年 | 723篇 |
2002年 | 713篇 |
2001年 | 367篇 |
2000年 | 382篇 |
1999年 | 371篇 |
1998年 | 182篇 |
1997年 | 177篇 |
1996年 | 175篇 |
1995年 | 143篇 |
1994年 | 121篇 |
1993年 | 118篇 |
1992年 | 250篇 |
1991年 | 206篇 |
1990年 | 242篇 |
1989年 | 246篇 |
1988年 | 232篇 |
1987年 | 167篇 |
1986年 | 136篇 |
1985年 | 135篇 |
1984年 | 107篇 |
1983年 | 88篇 |
1982年 | 59篇 |
1981年 | 51篇 |
1979年 | 84篇 |
1978年 | 60篇 |
1977年 | 48篇 |
1975年 | 40篇 |
1974年 | 48篇 |
1970年 | 39篇 |
1969年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
Yohei Ogawa Makoto Hiura Toru Kikuchi Keisuke Nagasaki Yukie Iwata Makoto Uchiyama 《Clinical Pediatric Endocrinology》2004,13(1):55-58
This study aimed to investigate the levels of serum low-density lipoprotein
cholesterol (LDLC) using direct measurement in healthy Japanese school children. The
subjects were 621 children (325 boys and 296 girls) aged 9 to 10 in the 4th grade, and 688
children (334 boys and 354 girls) aged 12 to 13 in the 7th grade. The levels of serum LDLC
and high-density lipoprotein cholesterol were measured by direct determination (Cholestest
LDL and Cholestest NHDL; Daiichi Pure Chemicals Co., Ltd., Tokyo, Japan). In boys in the
4th grade, the mean, the 75th, the 90th and the 95th percentiles of LDLC levels (mg/dl)
were 91.6, 104, 124 and 134, respectively. In girls in the 4th grade, they were 92.8, 108,
122 and 130. In boys in the 7th grade, they were 83.4, 96, 113 and 123. In girls in the
7th grade, they were 93.0, 106, 126 and 137. Serum LDLC levels in boys in the 7th grade
were lower than those of other groups. The direct measurement of serum LDLC level is
useful for evaluation of dyslipidemia in healthy school children, because the method is
applicable to non-fasting serum. 相似文献
62.
Nobuyuki Ishibashi Toshiharu Shin'oka Masakuni Ishiyama Takahiko Sakamoto Hiromi Kurosawa 《European journal of cardio-thoracic surgery》2007,32(2):202-208
OBJECTIVE: Our treatment strategy for pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collateral arteries is a staged repair that comprises the first complete unifocalization (UF) with 'unification' of intrapulmonary arteries and then the definitive repair. The purpose of this study is to evaluate the outcome of our staged repair strategy with complete UF and to determine the results of our current management strategy. METHODS: From 1982 to 2004, 113 consecutive patients were treated with staged repair at our institute. We evaluated the risk of definitive repair failure or death in the 3 years after definitive repair using logistic regression. Furthermore, we compared the early group (patients who underwent UF before December 1995) and the late group (patients who underwent UF after January 1996). RESULTS: The mean follow-up interval was 8.8 years (0.8 months to 23.3 years), and Kaplan-Meier-estimated overall survival rates after first UF were 80.9, 73.8, and 69.9% at 5, 10, and 15 years, respectively. Survival in patients with an absent central pulmonary artery (PA) was significantly lower than in those with a central PA (p<0.05), and the factor that was significantly associated with definitive repair failure or death in the 3 years after definitive repair was central PA morphology (p<0.05). Higher mean PA pressure after UF was detected in patients with hypoplastic central PA, compared with those without hypoplastic PA (30.9 mmHg vs 23.3 mmHg, p<0.05). In the late group, age (in years) at first UF (3.9 vs 8.4, p<0.01), second UF (4.3 vs 9.2, p<0.01), and definitive repair (5.8 vs 9.1, p<0.01) was significantly younger than in early group, and the survival rate after first UF in the late group was 96.2 and 91.3% at 3 and 7 years, respectively. Systolic right ventricular pressure and the pressure ratio between the right and the left ventricles after definitive repair in the late group were significantly lower than in the early group (53.6 mmHg vs 75.0 mmHg, p<0.01; 61.7% vs 75.9%, p<0.05). CONCLUSIONS: Hypoplastic central PA was a significant risk factor in this disease. The overall survival was improved by our current management strategy. Improved RV pressure after definitive repair appears to affect the long-term outcome. 相似文献
63.
Yoichi Kikuchi Taku Sakurada Masato Suzuki Tomoyasu Hirano Katsuyuki Kusajima 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(8):375-378
Off-pump coronary artery bypass grafting has become an attractive surgical alternative for myocar-dial revascularization because
of the advantage of myocardial protection and other benefits of patients. However, it is still regarded as a controversial
treatment for the coronary artery disease accompanied by atrial fibrillation (AF). A significant number of patients in need
of coronary revascularization have chronic AF. Although the Cox-Maze III procedure is the gold standard for the surgical treatment
of AF, few of these patients undergo AF operations at the time of their coronary bypass grafting. We report herein a case
of the pulmonary vein isolation to eliminate the AF by means of epicardial radiofrequency ablation combined with 2 vessels
coronary artery bypass grafting on the beating heart with the aid of cardiopulmonary bypass. 相似文献
64.
Atsushi Nakahira Hitoshi Ogino Hiroaki Sasaki Nobuyuki Katakami 《European journal of cardio-thoracic surgery》2007,32(2):388-390
Malignant pulmonary artery tumors represented by sarcomas are rare, but fatal. Early diagnosis and radical surgical resection offer the only chance for survival. However, surgical intervention has some challenging aspects, and prognosis is poor even after tumor resection. We report a case of a pulmonary artery sarcoma between the right ventricular outflow tract and the pulmonary artery branches. The tumor was aggressively extracted with reconstruction using a cryopreserved pulmonary valved allograft, followed by adjuvant chemoradiotherapy. At 56 months after surgery, the patient is well without any evidence of recurrence, demonstrating that aggressive surgical resection with adjuvant chemoradiotherapy can prolong survival. 相似文献
65.
S Kikuchi Y Takehana S Hamano K Ichikawa H Komatsu T Okegawa S Ikeda 《Nihon yakurigaku zasshi. Folia pharmacologica Japonica》1990,95(3):131-137
We studied the effects of OKY-046 on types II, III and IV allergic reactions, as classified by Coombs and Gell. In Type II, OKY-046 at 30-100 mg/kg intraduodenally (i.d.) and at 1-30 mg/kg intravenously (i.v.) inhibited the bronchoconstriction in a dose-dependent manner after Forssman antigen injection. Aspirin (3 mg/kg, i.v.) also suppressed it. OKY-046 (30-100 mg/kg, i.d.) suppressed the increase of TXB2 level in the plasma in a dose-dependent manner. However, there was no effect of OKY-046 and aspirin on the decrease in complement activity (CH50), platelets and leukocytes. Additionally, OKY-046 (300 mg/kg, p.o.) prolonged the survival time following Forssman antigen injection. However, the immune hemolysis reaction was not prevented by OKY-046 (10(-6)-10(-3) M). FUT-175 protected against the Forssman shock at 1 mg/kg, i.v. and the in vitro immune hemolysis reaction at 10(-5) M. In Type III, OKY-046 (300 mg/kg, p.o.) significantly suppressed the direct passive Arthus reaction and immune complex nephritis in rats. There was no effect of OKY-046 on the delayed-type hypersensitive response to picryl chloride in mice. We think that OKY-046 should be a beneficial drug for the treatment of types II and III allergic reactions. 相似文献
66.
Five cynomolgus monkeys treated with unilateral carotid ligation, renal hypertension, and beta-aminopropionitrile feeding were studied repeatedly by cerebral angiography to clarify the growth process of saccular cerebral aneurysms. Repeated angiography demonstrated saccular cerebral aneurysms in three of five monkeys; two aneurysms were found 15 months and a third 12 months after the operation. At autopsy, one saccular aneurysm was found to be bilocular in shape, and the others were unilocular. Fusiform aneurysms were also observed in four monkeys. Microscopic studies revealed the walls of the saccular aneurysms were very thin and consisted of fibrous tissue. In one aneurysm, the aneurysmal sac was almost obstructed by a well-organized thrombus. No evidence of intramural hemorrhage was found in any of the saccular cerebral aneurysms. The conversion of early aneurysmal changes into saccular aneurysms was found to occur abruptly, and no consistent growth rate was noted. The multiloculation of saccular aneurysms was closely related to the size of an aneurysm. The present study indicates that a saccular cerebral aneurysm may grow abruptly from one of several different kinds of early aneurysmal changes. 相似文献
67.
Effects of blood coagulation factor XIII on the development of experimental cerebral aneurysms in rats 总被引:1,自引:0,他引:1
Pathological and experimental studies have shown that cerebral aneurysms develop in part as a result of injury to the blood vessel wall. One of the peculiar aspects of aneurysm development is a defective proliferative or healing response to such injury. To examine this phenomenon, blood coagulation Factor XIII, which is known to enhance the healing process of wounds in general, was given to rats to induce experimental cerebral aneurysms. The rats were subjected to ligation of one common carotid artery and induction of hypertension, and were fed beta-aminoproprionitrile. Two weeks thereafter, Factor XIII was injected intravenously daily for 5 days (10 U/100 gm body weight/day). Twelve days after the start of Factor XIII injections, the rats were sacrificed and examined under light and electron microscopy. In seven of 12 bifurcations which developed small aneurysms, prominent intimal thickening was observed in the aneurysm lumen. In the most advanced cases, the aneurysm lumen was completely filled with proliferated smooth-muscle cells and collagen. In five of nine bifurcations that showed no aneurysm development, apparent intimal thickening was found at the site where aneurysms might be expected to grow. In the group of rats studied for induction of cerebral aneurysms but not given Factor XIII, none of 11 bifurcations with or without aneurysms showed such intimal thickening. The results indicated that the proliferative response at the sites of aneurysm development was modified by exogenous Factor XIII. 相似文献
68.
69.
Yuichi Ando Kenji Kikuchi Naoya Ichikawa Kazuhiko Meigata Yuji Nomura Kenshi Watanabe Yoshifumi Beck Hisakazu Degawa Shinji Tomikawa Takeshi Nagao Hisanori Chida 《Surgery today》1997,27(4):353-356
We herein report the case of a 53-year-old man with a nonspecific acute colonic ulcer whose liver function deteriorated after he had undergone hepatectomy. He was referred to our hospital for a hepatoma caused by hepatitis B virus and a right hemihepatectomy was performed. His liver function was poor after the operation, and minor complications such as pleural effusion and biliary fistula developed. A large amount of melena was seen 29 days after the hepatectomy and he developed hemorrhagic shock. Superior mesenteric arteriography revealed pooling of blood in both the hepatic flexure of the ascending colon and the cecum. An emergency right hemicolectomy was performed. There was a 5 x 1-mm ulcer 18 cm distal to the ileocecal valve. Numerous erosions were observed to be scattered throughout the colonic mucosa. The patient recovered slowly and was discharged 6 months after the hepatectomy. This is the first report of an acute colonic ulcer that could have been caused by liver dysfunction. 相似文献
70.
Tsunenori Nakakoshi Nobuyuki Fujita Kan Jong-Hon Noritoshi Takeichi Kazuo Miyasaka 《Journal of magnetic resonance imaging : JMRI》1994,4(4):559-562
To investigate the effects of in vivo copper on magnetic resonance (MR) images, the authors studied Long-Evans cinnamon rats, which develop hepatitis and hepatocellular carcinoma as a result of abnormal copper metabolism. The livers of the rats were imaged before hepatitis developed; the absence of hepatic disease was confirmed histopathologically. The copper that accumulated in the liver of the rats was thought to exist in the form of divalent ions, which were suspected of reducing the T1 and T2 of neighboring protons. However, the signal intensities of the liver on T1- and T2*-weighted images did not change, suggesting that in vivo copper, even when accumulated abnormally, does not influence the signal intensity of MR images. 相似文献