全文获取类型
收费全文 | 20692篇 |
免费 | 1116篇 |
国内免费 | 127篇 |
专业分类
耳鼻咽喉 | 191篇 |
儿科学 | 399篇 |
妇产科学 | 218篇 |
基础医学 | 2348篇 |
口腔科学 | 568篇 |
临床医学 | 1364篇 |
内科学 | 5631篇 |
皮肤病学 | 677篇 |
神经病学 | 1105篇 |
特种医学 | 967篇 |
外科学 | 3802篇 |
综合类 | 94篇 |
一般理论 | 3篇 |
预防医学 | 571篇 |
眼科学 | 209篇 |
药学 | 1355篇 |
中国医学 | 39篇 |
肿瘤学 | 2394篇 |
出版年
2023年 | 196篇 |
2022年 | 415篇 |
2021年 | 659篇 |
2020年 | 338篇 |
2019年 | 421篇 |
2018年 | 555篇 |
2017年 | 443篇 |
2016年 | 493篇 |
2015年 | 516篇 |
2014年 | 666篇 |
2013年 | 737篇 |
2012年 | 1254篇 |
2011年 | 1377篇 |
2010年 | 749篇 |
2009年 | 576篇 |
2008年 | 1083篇 |
2007年 | 1122篇 |
2006年 | 1028篇 |
2005年 | 942篇 |
2004年 | 821篇 |
2003年 | 723篇 |
2002年 | 696篇 |
2001年 | 454篇 |
2000年 | 502篇 |
1999年 | 413篇 |
1998年 | 159篇 |
1997年 | 135篇 |
1996年 | 146篇 |
1995年 | 102篇 |
1994年 | 105篇 |
1993年 | 109篇 |
1992年 | 377篇 |
1991年 | 329篇 |
1990年 | 323篇 |
1989年 | 330篇 |
1988年 | 317篇 |
1987年 | 298篇 |
1986年 | 258篇 |
1985年 | 244篇 |
1984年 | 180篇 |
1983年 | 166篇 |
1979年 | 103篇 |
1978年 | 71篇 |
1977年 | 78篇 |
1974年 | 76篇 |
1973年 | 73篇 |
1972年 | 74篇 |
1971年 | 70篇 |
1970年 | 80篇 |
1969年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Lung cancer mortality rates among United States and Japanese males were compared and related to smoking and dietary data. Mortality rates increased from 1950 to 1985 in both countries, but the absolute values are consistently lower in Japan (38.2 deaths/100,000 in 1985) than in the U.S. (72.2/100,000). The proportion of smokers is higher in Japan than in the U.S. since 1955. Japanese males start smoking considerably later than U.S. males, but smoke a higher quantity of cigarettes per day. Available information on inhalation practices and yield and type of cigarettes smoked showed no differences among the two countries large enough to account for the differences in mortality rates. Further data in this regard should he obtained. Dietary data show that fat consumption (as percentage of calories) is consistently higher in the U.S. than in Japan from 1950 (40% vs. 7.9%) through 1985 (43.5% vs. 24.5%). A linear relationship is observed between lung cancer mortality and fat intake. Our data support the hypothesis that dietary habits may modulate the carcinogenic effects of tobacco smoking. 相似文献
52.
53.
54.
The angiographic features of left spontaneous carotid-cavernous sinus fistula and multiple dural arteriovenous malformations that developed after transvenous embolization are described. A dural arteriovenous malformation involving the left sigmoid sinus was demonstrated, along with a marked decrease in size of the left carotid-cavernous sinus fistula and the disappearance of venous drainage from the left cavernous to the right cavernous sinus after embolization with spring coils via the left superior ophthalmic vein. The dural arteriovenous malformation of the left sigmoid sinus subsequently extended to the transverse sinus after partial embolization of the sigmoid sinus. Finally, a dural arteriovenous malformation involving the left transverse sinus developed, with the disappearance of the arteriovenous malformation affecting the sigmoid sinus and left carotid-cavernous sinus fistula following complete embolization of the sigmoid sinus via the left transverse sinus. 相似文献
55.
Tissue specimens from patients with the scirrhous type of gastric carcinoma were stained using the peroxidase-antiperoxidase (PAP) method. Nine out of thirty-seven specimens (24 per cent) showed positive estrogen staining, and here tissues from male or older patients were usually stained. Cumulative survival rate in patients whose tissue showed a positive estrogen staining was higher than that in case of a negative estrogen staining. Four out of thirty-one specimens (13 per cent) stained positively for progesterone, all four patients being male. These results suggest that estrogen and progesterone may relate to the growth of the scirrhous type of gastric cancer. 相似文献
56.
Kagayaki Kuroda Daisuke Kokuryo Etsuko Kumamoto Kyohei Suzuki Yuichiro Matsuoka Bilgin Keserci 《Magnetic resonance in medicine》2006,56(4):835-843
Referenceless, or self-reference, thermometry is a technique for mapping temperature differences in the region of interest (ROI) using the baseline phase estimated by extrapolating the field in the surrounding region for estimation (RFE) and subtracting the estimated baseline from the measured field. In the present work a self-reference technique based on complex field estimation using 2D polynomials comprising complex-valued coefficients was proposed and optimized. Numerical simulations with a Gaussian-profiled phase distribution demonstrated that the ROI radius had to be 2.3-2.5 times the standard deviation (SD) of the Gaussian function in order to keep the error below 8% of the peak phase change. The area ratio between the ROI and the RFE had to be larger than 2.0 to maintain the error level. Based on the simulations, and phantom and volunteer experiments, the complex-based method with independently optimized polynomial orders for the two spatial dimensions was compared with the phase-based method using the similar-order optimization strategy. The complex-based method appeared to be useful when phase unwrapping was not removed. Otherwise, the phase-based method yielded equivalent results with less polynomial orders. 相似文献
57.
Eiji Fukuyama Susumu Omura Kiyohide Fujita Kunimichi Soma Katsuyuki Torikai 《The Cleft palate-craniofacial journal》2006,43(6):673-677
OBJECTIVE: This article reports a case of bilateral cleft lip and alveolus (BCLA) for which excessive rapid palatal expansion with a Latham appliance was performed for preoperative alignment of the protruded premaxilla. Postoperative changes of maxillary width were investigated with serial plaster casts. PATIENT AND RESULTS: A 3-month-old girl presented with complete BCLA in which the premaxilla was markedly protruded. Preoperative alignment of the protruded premaxilla with a Latham appliance was planned to facilitate primary lip repair. The appliance was placed when the patient was 4.5 months old. The necessary palatal expansion was estimated to be 7.0 mm in order to move the premaxilla backward into the ideal position. After palatal expansion and posterior repositioning of the protruded premaxilla, the primary operation, including cheiloplasty and gingivoperiosteoplasty, was performed when the patient was 7 months old. Excessive maxillary expansion might be a cause of transverse maxillomandibular discrepancy. Measurement with serial plaster casts demonstrated that maxillary widths increased from 42.3 mm pretreatment to 49.0 mm after orthopedic treatment but relapsed markedly to 43.5 mm at 3 months after the primary operation. Therefore, the net change of maxillary widths was only 1.2 mm. After alignment of the protruded premaxilla, tension-free soft tissue repairs were performed, and a harmonious alveolar arch was obtained without change in maxillary width. CONCLUSION: These results indicate that this method is useful for preoperative management of BCLA with protruded premaxilla. 相似文献
58.
O Yoshida Y Kakehi Y Nishio T Tomoyoshi T Konami T Usui M Igawa I Takenaka K Fujita 《Hinyokika kiyo. Acta urologica Japonica》1992,38(12):1437-1443
The influence of N1-(2-tetrahydrofuryl)-5-fluorouracil plus uracil (UFT) on the recurrence of superficial bladder tumors was evaluated in a randomized clinical study. Group A (n = 196) underwent transurethral resection (TUR) and the intravesical chemoprophylaxis, while group B (n = 193) received 400 mg per a day of UFT orally for 6 months in addition to the instillation therapy. These adjuvant therapy was started one week after TUR. Consequently, 30 patients in group B showed UFT-related toxicity and administration of UFT was discontinued in 10 of them. In addition, 87 patients in group B did not complete the 6-month course of UFT administration. Comparison of 2-year actuarial non-recurrence curves revealed no significant difference between groups A and B. However, UFT seemed to have a favorable prophylactic effect when recurrence rates were compared among those patients with recurrent tumors (generalized Wilcoxon: p = 0.1277), and those with recurrent multiple tumors (p = 0.0847). 相似文献
59.
A case-control study of breast cancer among Japanese women: with special reference to family history and reproductive and dietary factors 总被引:8,自引:0,他引:8
Dr. Ikuko Kato Dr. Shigeto Miura Fijio Kasumi Takuji Iwase Hideya Tashiro Yoshihiro Fujita Hiroki Koyama Tadashi Ikeda Kiyoshi Fujiwara Keiichi Saotome Kazuaki Asaishi Rikiya Abe Mitsuhiro Nihei Tsunehiro Ishida Takao Yokoe Hiroshi Yamamoto Motoi Murata 《Breast cancer research and treatment》1992,24(1):51-59
Summary To study the effects of family history and reproductive, anthropometric, and dietary factors on the risk of breast cancer among low risk populations, we conducted a hospital-based case-control study involving 908 patients with breast cancer and their matched controls, in Japan. A positive family history of breast cancer significantly increased the risk of breast cancer (odds ratio = 1.52, 95% confidence interval: 1.14–2.03). The risk further increased with increasing number of family members affected. Obesity, single marital status, fewer births, a late childbirth, and less consumption of green-yellow vegetables and dairy products were also associated with an increased risk of breast cancer. These associations were independent in multivariate analyses. There was no increase in risk associated with consumption of high fat foods. When analyzed by menopausal status, the association with family history of breast cancer, especially in the first degree of relatives, was more evident for premenopausal breast cancer. The associations with obesity and lower consumption of dairy products were more pronounced for postmenopausal breast cancer, while those with lower parity and single marital status were stronger for premenopausal breast cancer. 相似文献
60.