全文获取类型
收费全文 | 21177篇 |
免费 | 1264篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 344篇 |
儿科学 | 1162篇 |
妇产科学 | 504篇 |
基础医学 | 1834篇 |
口腔科学 | 381篇 |
临床医学 | 1674篇 |
内科学 | 5031篇 |
皮肤病学 | 347篇 |
神经病学 | 1058篇 |
特种医学 | 742篇 |
外科学 | 3827篇 |
综合类 | 468篇 |
一般理论 | 3篇 |
预防医学 | 1144篇 |
眼科学 | 918篇 |
药学 | 1594篇 |
1篇 | |
中国医学 | 77篇 |
肿瘤学 | 1397篇 |
出版年
2023年 | 179篇 |
2022年 | 368篇 |
2021年 | 813篇 |
2020年 | 423篇 |
2019年 | 640篇 |
2018年 | 745篇 |
2017年 | 520篇 |
2016年 | 527篇 |
2015年 | 521篇 |
2014年 | 815篇 |
2013年 | 1013篇 |
2012年 | 1524篇 |
2011年 | 1398篇 |
2010年 | 874篇 |
2009年 | 684篇 |
2008年 | 1028篇 |
2007年 | 1042篇 |
2006年 | 981篇 |
2005年 | 912篇 |
2004年 | 810篇 |
2003年 | 692篇 |
2002年 | 624篇 |
2001年 | 491篇 |
2000年 | 521篇 |
1999年 | 413篇 |
1998年 | 165篇 |
1997年 | 139篇 |
1996年 | 118篇 |
1995年 | 118篇 |
1994年 | 106篇 |
1993年 | 82篇 |
1992年 | 283篇 |
1991年 | 257篇 |
1990年 | 223篇 |
1989年 | 217篇 |
1988年 | 173篇 |
1987年 | 180篇 |
1986年 | 159篇 |
1985年 | 170篇 |
1984年 | 151篇 |
1983年 | 142篇 |
1982年 | 67篇 |
1981年 | 75篇 |
1979年 | 121篇 |
1978年 | 88篇 |
1977年 | 63篇 |
1974年 | 75篇 |
1973年 | 112篇 |
1972年 | 105篇 |
1971年 | 70篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
The indications for elective treatment of the neck in cancer of the major salivary glands. 总被引:8,自引:0,他引:8
J G Armstrong L B Harrison H T Thaler H Friedlander-Klar D E Fass M J Zelefsky J P Shah E W Strong R H Spiro 《Cancer》1992,69(3):615-619
To define the indications for elective neck treatment, the cases of 474 previously untreated patients were reviewed who had locally confined major salivary gland cancers treated between 1939 and 1982. Clinically positive nodes were present in 14% (67 of 474). Overall, clinically occult, pathologically positive nodes occurred in 12% (47 of 407). By univariate analysis, several factors appeared to predict the risk of occult metastases; however, multivariate analysis revealed that only size and grade were significant risk factors. Tumors 4 cm or more in size had a 20% (32 of 164) risk of occult metastases compared with a 4% (nine of 220) risk for smaller tumors (P less than 0.00001). High-grade tumors (regardless of histologic type) had a 49% (29 of 59) risk of occult metastases compared with a 7% (15 of 221) risk for intermediate-grade or low-grade tumors (P less than 0.00001). In view of the low frequency of occult metastases in the entire group, routine elective treatment of the neck is not recommended. High-grade tumors and larger tumors have a high rate of occult neck metastases, and treatment should be considered in this group. 相似文献
22.
Deacon E. Harle Keri Davies Rakhee Shah Syma Hussain Susan Cowling Tejinder K. Panesar Jonathan Bourton Bruce J. W. Evans 《Ophthalmic & physiological optics》2007,27(1):100-105
Despite the current popularity of binocular indirect ophthalmoscopy, direct ophthalmoscopes are still commonly used by clinicians for fundus examination. They are considered to be expensive, however, and it has been suggested that this cost can prevent their use by healthcare professionals in developing countries. The Optyse Lens Free Ophthalmoscope is a novel direct ophthalmoscope, without a lens focus system, that allows for comparatively inexpensive manufacture and supply. We compared the clarity of view with the Optyse to that with standard direct ophthalmoscopes, over a sequential cohort of patients with a variety of refractive errors and ocular conditions. The grade of clarity of view with the Optyse Lens Free Ophthalmoscope was less than conventional ophthalmoscopes (Wilcoxon signed rank test, p < 0.0001). This grade of clarity of view was not associated with the ametropia of the ophthalmoscopic observation (Spearman r < or = 0.03, p > or = 0.28) but was with the presence of cataracts (chi2 test, p < 0.0001) with both the Optyse and the conventional ophthalmoscopes. Despite its limitations, the retinal view with Optyse was often within acceptable clinical limits suggesting that this relatively inexpensive ophthalmoscope may have a place when cost prohibits any other type of ophthalmoscope use. 相似文献
23.
24.
This is a report of a patient on treatment for duodenal tuberculosis, who developed obstructive jaundice due to a benign stricture of the terminal common bile duct. This complication of duodenal tuberculosis, to our knowledge, has not been reported before. Percutaneous, transhepatic balloon dilatation of the stricture alleviated the jaundice. 相似文献
25.
We present our experience with twenty children with insulin dependent diabetes mellitus admitted during the past 2 1/2 years.
Sixteen patients were admited with acute onset of ketoacidosis while four were having gradual onset. Active and symptomatic
treatment was started in all diabetic ketoacidotic patients. One patient died during the acute stage. Eleven patients were
followed for 3–6 months or more. Glycosylated hemoglobin was considered as a criteria for control. Three had good control,
two fair and six poor control; six developed diabetic ketoacidosis and three developed hypoglycemia 相似文献
26.
Is antibiotic prophylaxis necessary for routine urodynamic investigations? A controlled study in 100 patients 总被引:1,自引:0,他引:1
The value of a prophylactic antibiotic before a routine cystometrogram has been assessed in a controlled trial of 100 patients. The infection rate was low and not statistically different in both groups. Subsequent symptoms of dysuria and haematuria had a mechanical aetiology. 相似文献
27.
BACKGROUND: Amalgam tattoos result from deposition of metallic particles (eg, silver, mercury, copper, zinc, and tin) into the oral mucosa. Their clinical and histologic appearance is similar to that of decorative tattoos. OBJECTIVE: To describe the successful use of a Q-switched alexandrite laser for removal of an amalgam tattoo. MATERIALS AND METHODS: An amalgam tattoo on the buccal mucosa and gingiva was treated with a QS 755 nm alexandrite laser. Three treatments were delivered at 8-week time intervals (average fluence = 6.8 J/cm2). RESULTS: Significant lightening of the tattoo was achieved after each of the three treatments without adverse sequelae. CONCLUSION: Q-switched alexandrite laser irradiation can safely and effectively eradicate amalgam tattoos. 相似文献
28.
29.
M Davidson L Bastiaens B M Davis M B Shah K L Davis 《Endocrinology & Metabolism Clinics of North America》1988,17(1):149-157
In conclusion, at present, no consistent endocrine abnormalities can be detected in patients suffering from Alzheimer's disease. However, assessment of neuroendocrine function might help identify subpopulations of patients with particular neurotransmission abnormalities who are likely to benefit from a specific pharmacologic strategy. For example, patients in whom cholinomimetic drugs produce the greatest elevation in plasma cortisol concentration appear to derive the most symptomatic benefit from these drugs. 相似文献
30.
D A Kaffenberger C P Shah F R Murtagh C Wilson M L Silbiger 《Journal of computer assisted tomography》1988,12(3):495-498
A case of isolated spinal cord hemangioblastoma with associated extensive syringohydromyelia, which was evaluated by myelography, postmyelographic CT, magnetic resonance (MR), and angiography is presented. The specific preoperative and postoperative advantages of MR are given as well as a brief review of the literature. 相似文献