全文获取类型
收费全文 | 11319篇 |
免费 | 621篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 102篇 |
儿科学 | 789篇 |
妇产科学 | 340篇 |
基础医学 | 1236篇 |
口腔科学 | 229篇 |
临床医学 | 689篇 |
内科学 | 2233篇 |
皮肤病学 | 366篇 |
神经病学 | 619篇 |
特种医学 | 306篇 |
外国民族医学 | 1篇 |
外科学 | 1601篇 |
综合类 | 278篇 |
一般理论 | 12篇 |
预防医学 | 475篇 |
眼科学 | 559篇 |
药学 | 1200篇 |
中国医学 | 57篇 |
肿瘤学 | 886篇 |
出版年
2023年 | 81篇 |
2022年 | 181篇 |
2021年 | 379篇 |
2020年 | 226篇 |
2019年 | 305篇 |
2018年 | 346篇 |
2017年 | 272篇 |
2016年 | 347篇 |
2015年 | 315篇 |
2014年 | 442篇 |
2013年 | 591篇 |
2012年 | 808篇 |
2011年 | 861篇 |
2010年 | 459篇 |
2009年 | 345篇 |
2008年 | 612篇 |
2007年 | 574篇 |
2006年 | 487篇 |
2005年 | 450篇 |
2004年 | 414篇 |
2003年 | 336篇 |
2002年 | 323篇 |
2001年 | 289篇 |
2000年 | 291篇 |
1999年 | 243篇 |
1998年 | 92篇 |
1997年 | 65篇 |
1996年 | 82篇 |
1995年 | 63篇 |
1994年 | 47篇 |
1993年 | 43篇 |
1992年 | 117篇 |
1991年 | 159篇 |
1990年 | 126篇 |
1989年 | 106篇 |
1988年 | 107篇 |
1987年 | 75篇 |
1986年 | 85篇 |
1985年 | 89篇 |
1984年 | 65篇 |
1983年 | 68篇 |
1979年 | 66篇 |
1978年 | 44篇 |
1977年 | 35篇 |
1975年 | 34篇 |
1973年 | 38篇 |
1972年 | 41篇 |
1971年 | 44篇 |
1969年 | 32篇 |
1968年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
51.
An unusual case of dorsal spinal dysraphism in a four year old child is presented. Various abnormalities including diastematomyelia, an extradural arachnoid cyst arising from one of the two dural tubes, and lipomeningomyelocele with a related rib-like bony structure were demonstrated with Iohexol CT and subsequently confirmed at surgery. 相似文献
52.
To improve the in vivo performance of engineered implants, this study examines the independent effects of surface chemistry and topography on fibroblast morphology and density in vitro. Titanium (Ti) was sputter-coated onto smooth and microtextured polyethylene terephthalate (PET). Test specimens were evaluated in 24-h, fibroblast cultures and assessed with scanning electron microscopy (SEM) for cellular morphology and density. Fibroblast density increased, as the Ti film thickness increased. The fibroblasts exhibited contact guidance on the textured test specimens. The greatest cellular density was found on the Ti-coated, textured test specimens. In conclusion, Ti and surface texture appeared to strongly influence fibroblast density and morphology as compared to PET and smooth surfaces. 相似文献
53.
Joanne R. Less Mitchel C. Posner Thomas C. Skalak Norman Wolmark Rakesh K. Jain 《Microcirculation (New York, N.Y. : 1994)》1997,4(1):25-33
Objective : To measure the geometric resistance to blood flow in human colorectal carcinoma. Although tumor blood flow is of central importance in both the detection and the treatment of cancer, the determinants of blood flow through the neoplastic circulation are poorly understood. Methods : Human colorectal carcinomas (tissue weight = 272 g ± 43 g (SD), n = 6) were perfused ex vivo with a buffered physiological salt solution of known viscosity at flow rates ranging from 2.5 to 40 ml/min and perfusion pressures from 8 to 100 mm Hg. The geometric resistance was determined from the slope of the pressure-flow curve. For examination of the principal determinant of geometric resistance, the vascular architecture, one of the tumors was perfused with Batson's No. 17 polymer and macerated in KOH to produce a positive vascular cast that was used for measurement of vascular branching patterns and dimensions. Results : The pressure-flow relationship was linear at perfusion pressures above 40 mm Hg, and the geometric resistance, z0, was constant at approximately 6.5 ± 109g/cm3. Below 40 mm Hg, z0 increased rapidly. The architecture of the arteriolar and capillary networks of human colorectal carcinoma is similar to those of experimental rodent tumors. Capillaries in planar and nonplanar mesh-works had mean segment diameters of 11 ± 2 and 9.6 ± 2 μm, lengths of 46 ± 24 and 107 ± 40 μm, and intercapillary distances of 46 ± 13 and 74 ± 24 μm, respectively. Conclusions : The geometric flow resistance in neoplastic tissue is 1–2 orders of magnitude higher than that observed in normal tissues. A decrease in functional vascular cross-sectional area may explain the additional increase in resistance at small perfusion pressures. The observed flow resistance may be due to the specialized arteriolar and capillary network architecture, pressures exerted by proliferating cancer cells, and/or coupling between vascular and extravascular flow. These observations demonstrate that tumor vascularity alone may not be indicative of flow resistance or tumor susceptibility to blood-borne therapeutic agents. 相似文献
54.
Subtotal thyroidectomy was performed for hyperthyroidism on 130 patients; 95 treated before surgery with propranolol (Group I) and 35 given only metoprolol before surgery (Group II). These patient groups were compared with reference to preoperative medication, operative and immediate postoperative course, and late results with follow-up for one to five years. Clinical response was 100% in group II and 94.7% in group I. The median length of preoperative treatment was 7.96 +/- 1.84 days in group I and 6.25 +/- 1.73 days in group II (P less than 0.05). There were no serious adverse effects of the drugs in either treatment group. No anaesthesiologic or cardiovascular complication occurred during operation in either group. Ten patients in group I (10.5%) and six patients in group II (11.4%) observed hyperthyroid manifestations in the immediate postoperative period, eliminated by the administration of the propranolol/metoprolol, and no case of thyroid storm occurred. One patient in group II developed clinical hypocalcaemia. Two patients, one in each group, presented temporary unilateral recurrent laryngeal nerve paralysis. There were two recurrences of toxicity in group I (2.1%) and none in group II. Hypothyroidism occurred in 3 patients (2.3%) two of them were from group I and one was from group II. The postoperative hospital stay was 4.62 +/- 1.61 days in group I and 2.81 +/- 1.32 days in group II (P less than 0.05). One patient from group I died on the third postoperative day due to pulmonary oedema. The results suggest that metoprolol can be safely used and offers the advantages of desired clinical response, shorter preoperative preparation time, simplicity of dosage and shorter postoperative hospital stay in comparison to propranolol for preoperative treatment of hyperthyroidism. 相似文献
55.
56.
57.
Pooja Parashar Ole Erik Iversen Grete Midb?e Ole Myking Line Bj?rge 《The European journal of contraception & reproductive health care》2007,12(4):366-371
OBJECTIVE: The combination of mifepristone and misoprostol is an established method for induction of early first trimester abortion, but there is no consensus about the best evaluation of treatment outcome. We assessed endometrial thickness, determined by ultrasound and serum-human chorionic gonadotropin (s-hCG) as markers of successful management. METHODS: Prospective trial involving 255 women, with a gestation of 62 days or less, who were to undergo medical abortion. In addition to our established routines of performing clinical and ultrasound examinations, we also determined the s-hCG level prior to treatment and at follow-up. RESULTS: Of the 255 subjects treated during the study, 20 (7.8%) were lost to follow-up. The overall complete abortion rate was 94.0%. Fourteen subjects required vacuum aspiration, nine of them prior to the scheduled follow-up and five thereafter. None of the pregnancies were ongoing. A decrease of 99% in s-hCG levels was noted in 99% of the women, when levels determined prior to mifepristone intake and those measured 15-71 days post-abortion were compared. CONCLUSION: This study confirms that s-hCG levels drop sharply after medical abortion. To assess the completeness of medical abortion, we recommend that clinical examination to be combined with determination of s-hCG. Ultrasonography should be carried out only when indicated. 相似文献
58.
Hepatitis induced by traditional Chinese herbs; possible toxic components. 总被引:12,自引:0,他引:12 下载免费PDF全文
Traditional Chinese herbal remedies are widely available in the United Kingdom for the treatment of chronic skin disorders. Their benefits are considerable, but their use is completely unregulated. Two patients are described here who suffered an acute hepatitic illness related to taking traditional Chinese herbs. Both recovered fully. The mixtures that they took included two plant components also contained within the mixture taken by a previously reported patient who suffered fatal hepatic necrosis. These cases high-light the need for greater awareness of both the therapeutic and toxic potential of herbal remedies, as well as greater control of their use. 相似文献
59.
S. S. Borwankar L. S. Kasat A. Naregal M. Jain R. Bajaj 《Pediatric surgery international》1998,14(1-2):129-130
A case of covered exstrophy without sequestration of a bowel segment is reported. A 4-year-old female presented with dribbling
of urine. Treatment to date has been simple excision of the covered membrane with functional closure of the bladder and bilateral
posterior iliac osteotomies, with reconstruction of the bladder neck and genitalia to be performed at a later date. The embryogenesis
of this rare variant, a review of the reported cases, and management options are discussed.
Accepted: 6 November 1997 相似文献
60.
J A DeLisa S S Jain D Campagnolo P H McCutcheon 《American journal of physical medicine & rehabilitation / Association of Academic Physiatrists》1992,71(2):72-76
A 35-item questionnaire, designed to assess the relative importance of various factors to medical students when ranking physical medicine and rehabilitation (PM&R) residency training programs during the Match, was sent to all members of the 1991 senior class after Match Day. This mailing was coordinated with the National Resident Matching Program. The questionnaire was also sent to all PM&R residency training program directors and all physiatrist faculty members at the University of Medicine and Dentistry of New Jersey--New Jersey Medical School (UMDNJ-NJMS). Recipients were asked to grade selection factors based on a numerical scale: 1, extremely important; 2, very important; 3, important; 4, minimally important; 5, not important. A response rate of 41% (73/179) for medical students, 87% (62/71) for residency training directors and 71% (22/31) for UMDNJ-NJMS faculty members was attained. Analysis of the results indicates that, overall, there is no significant difference in ranking of the factors by each of the three groups surveyed. The intergroup responses for one-third of the factors were significantly different. Diversity of the training experience, current house officer satisfaction, it "feels" right and house officer quality were the four most important selection factors to the medical students. 相似文献