全文获取类型
收费全文 | 4341篇 |
免费 | 402篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 109篇 |
妇产科学 | 86篇 |
基础医学 | 598篇 |
口腔科学 | 89篇 |
临床医学 | 517篇 |
内科学 | 560篇 |
皮肤病学 | 97篇 |
神经病学 | 628篇 |
特种医学 | 233篇 |
外科学 | 641篇 |
综合类 | 131篇 |
一般理论 | 2篇 |
预防医学 | 366篇 |
眼科学 | 95篇 |
药学 | 250篇 |
中国医学 | 25篇 |
肿瘤学 | 280篇 |
出版年
2021年 | 50篇 |
2020年 | 39篇 |
2019年 | 49篇 |
2018年 | 63篇 |
2017年 | 39篇 |
2016年 | 38篇 |
2015年 | 58篇 |
2014年 | 84篇 |
2013年 | 128篇 |
2012年 | 153篇 |
2011年 | 157篇 |
2010年 | 119篇 |
2009年 | 108篇 |
2008年 | 164篇 |
2007年 | 190篇 |
2006年 | 219篇 |
2005年 | 208篇 |
2004年 | 188篇 |
2003年 | 164篇 |
2002年 | 137篇 |
2001年 | 129篇 |
2000年 | 138篇 |
1999年 | 119篇 |
1998年 | 72篇 |
1997年 | 73篇 |
1996年 | 74篇 |
1995年 | 78篇 |
1994年 | 50篇 |
1993年 | 36篇 |
1992年 | 113篇 |
1991年 | 101篇 |
1990年 | 137篇 |
1989年 | 123篇 |
1988年 | 106篇 |
1987年 | 110篇 |
1986年 | 89篇 |
1985年 | 99篇 |
1984年 | 75篇 |
1983年 | 67篇 |
1982年 | 45篇 |
1981年 | 45篇 |
1980年 | 33篇 |
1979年 | 48篇 |
1978年 | 49篇 |
1977年 | 31篇 |
1976年 | 28篇 |
1975年 | 28篇 |
1974年 | 29篇 |
1973年 | 36篇 |
1972年 | 29篇 |
排序方式: 共有4749条查询结果,搜索用时 0 毫秒
21.
Ca2+-Mg2+ ATPase of mouse cardiac sarcoplasmic reticulum is affected by membrane n-6 and n-3 polyunsaturated fatty acid content 总被引:1,自引:0,他引:1
White mice, 18-20 g, were fed purified diets containing two weight percent safflower oil plus ten weight percent menhaden, corn, or olive oil for 2 wk. Menhaden oil ingestion resulted in significantly higher levels of 22:6(n-3) and 20:5(n-3), particularly 22:6(n-3), and lower levels of 20:4(n-6) and 18:2(n-6) in cardiac sarcoplasmic reticulum (SR) phospholipids than did corn or olive oil ingestion. These changes in fatty acid composition resulted in a significant decrease in the value of the n-6/n-3 fatty acid ratio of cardiac SR phospholipids. The ratio was 2.8 versus 0.2 in choline phospholipids and 1.9 versus 0.2 in ethanolamine phospholipids in SR of mice fed corn or menhaden oil, respectively. This reduction in the n-6/n-3 fatty acid ratio was associated with a lower relative activity of Ca2+-Mg2+ ATPase, and a lower initial rate of calcium transport and maximum calcium uptake in SR vesicles from mice fed menhaden oil rather than olive or corn oils. The specific activity of NADPH cytochrome C reductase (EC 1.6.2.3) of cardiac SR was not affected by dietary lipids. These data indicate that modification of SR by 22:6(n-3) may change the SR bilayer structure resulting in alteration of the calcium transport properties of SR vesicles. In addition, our results suggest that reduction of calcium flux across cardiac SR following fish oil consumption may also reduce the susceptibility of myocytes to rapid changes in calcium concentrations which may occur during ischemia and reperfusion. 相似文献
22.
S. J. Carbognin N. M. Solomon F. E. Yeo S. J. Swanson E. M. Bohen J. M. Koff S. G. Sabnis K. C. Abbott 《American journal of transplantation》2006,6(7):1746-1751
Interferon alpha (IFN-alpha) can be effective therapy for patients with chronic kidney disease who have chronic hepatitis C (HCV). However, acute allograft rejection has been reported in association with IFN-alpha following kidney transplantation, and therefore IFN therapy is recommended prior to, rather than after, kidney transplantation whenever feasible. The special case of repeat allograft recipients who contract HCV after the first transplantation presents special difficulties. This report features the case of a repeat allograft recipient who presented with neutropenic fevers after 5 months of pegylated IFN-alpha therapy, initiated 6 months following the functional loss of his third graft and the reinitiation of hemodialysis (HD). Physical exam, radiographic and laboratory findings led to allograft nephrectomy. The pathologic findings supported a diagnosis of acute-on-chronic rejection. This represents a rare case of IFN-alpha induced rejection following allograft failure and return to HD in a repeat allograft recipient. It also calls attention to the need for a high index of suspicion for the development of allograft rejection, which may require allograft nephrectomy even after allograft 'failure'. 相似文献
23.
Tricholemmal carcinoma: 总被引:4,自引:0,他引:4
P.E. Swanson A.J. Marrogi D.J. Williams D.L. Cherwitz M.R. Wick 《Journal of cutaneous pathology》1992,19(2):100-109
Tricholemmal carcinoma (TLC) is a cutaneous adnexal tumor with presumed external hair sheath differentiation. In order to better understand the salient features of this neoplasm, we analyzed the histologic and clinical findings in 10 cases of TLC. Eight patients were males, and two were female; they ranged in age from 55-88 years. Each tumor occurred in hair bearing, sun-exposed skin, and involved the scalp, face, trunk, or upper extremities. The lesions were usually slightly raised, pale tan or reddish, and keratotic; were usually present for less than 1 year; and measured 0.4-2.0 cm. All of them were treated by wide local excision; neither recurrence nor metastasis was reported after 11 to 92 months of clinical followup. Histologically, each TLC was composed of a lobular proliferation centered on the pilar apparatus. Cells with glycogen-rich, mucin-negative, clear or pale eosinophilic cytoplasm predominated. Brisk mitotic activity (4-39 mitoses per 10 high power fields) was typical. Involvement of the interfollicular epidermis was invariably noted, with superficial ulceration in seven tumors. Transitional zones between TLC and the adjacent epidermis were not seen, although pagetoid spread occurred in two examples. Invasion of reticular dermis was present in eight cases, with infiltration to mid-dermis in five TLC. All tumors exhibited areas of tricholemmal type keratinization; dyskeratotic cells were noted in six examples. Hyperkeratosis and parakeratosis were variably present as well. Actinic damage was a constant feature. Despite local invasion at diagnosis, the clinical course of TLC was indolent in all cases. 相似文献
24.
The utility of MRI using magnetization transfer (MT) enhanced pulse sequences to diagnose hepatic cirrhosis in a rat model was investigated. Hepatic T1 was measured with and without MT off-resonance RF pulses in 17 treated and six control rats. The livers were evaluated histologically, and the hydroxyproline content quantitatively measured. We did not find a statistically significant linear correlation between the MR relaxation times and the degree of tissue injury. However, the MR measurements performed with MT were superior to those without differentiating the treated and control groups. Specifically, the T1 times were 695 ±76 ms for the treated group, versus 748 ± 61 ms in the controls; P= 0.095. The T1sat times were also lower in the treated group, with statistical significance: 367 ± 51 ms versus 421 ± 38 ms, P = 0.016. Finally, the change in the relaxation rates (the inverse of the relaxation times) with and without saturation were 1.31 ± 0.22 s?1 (treated group) versus 1.05 ± 0.12 s?1 (controls), which differed significantly, P= 0.001. 相似文献
25.
Renal cell carcinoma. A clinicopathologic and DNA flow cytometric analysis of 103 cases 总被引:2,自引:0,他引:2
D J Grignon A G Ayala A el-Naggar K I Wishnow J Y Ro D A Swanson D McLemore G G Giacco V F Guinee 《Cancer》1989,64(10):2133-2140
Renal cell carcinoma is unpredictable in outcome, although the best predictor is tumor stage, followed by histologic grade. The authors retrospectively assessed the clinicopathologic features and DNA ploidy of 103 cases of renal cell carcinoma, the latter determined by flow cytometry of formalin-fixed, paraffin-embedded tissue. The study group comprised 63 men and 40 women (age, 28-80 years; mean, 57 years). Robson stage at diagnosis was Stage I in 52 patients, Stage II in 21, and Stage III in 30. Statistically significant variables in predicting outcome were Robson stage (P less than 0.0001), DNA ploidy (P = 0.0008), mitotic rate (MR, P less than 0.0001), worst nuclear grade (WNG, P = 0.00009), predominant nuclear grade (P = 0.019), and sex (P = 0.044). Tumor size, cell type, and architectural pattern were also assessed but did not prove to be significant. Statistically significant associations occurred between DNA ploidy and WNG (P less than 0.0001), stage (P = 0.0037), and MR (P = 0.015); between WNG and MR (P less than 0.0001) and stage (P = 0.0007); and between stage and MR (P = 0.002). Cox proportional hazards regression analysis of all significant variables showed Robson stage, tumor ploidy, and MR to be independent, significant predictors of outcome. If ploidy data had not been available, WNG would have been independently significant. The authors conclude that DNA ploidy analysis provides significant predictive information on renal cell carcinoma. 相似文献
26.
27.
Van Buskirk Glenn A. González Mario A. Shah Vinod P. Barnhardt Scott Barrett Colin Berge Stephen Cleary Gary Chan Keith Flynn Gordon Foster Thomas Gale Robert Garrison Raymond Gochnour Scott Gotto Amanda Govil Sharad Gray Vivian A. Hammar James Harder Samuel Hoiberg Charles Hussain Ajaz Karp Carol Llanos Hector Mantelle Juan Noonan Patrick Swanson David Zerbe Horst 《Pharmaceutical research》1997,14(7):848-852
Pharmaceutical Research - 相似文献
28.
M W Swanson 《Journal of the American Optometric Association》1990,61(4):296-308
Metastatic cancer is the most common form of neoplasm affecting the eyes and orbit. Six cases of metastatic cancers with origination or dissemination within the visual system are presented. Typical and atypical characteristics of metastatic cancer of the visual system are discussed. 相似文献
29.
The asymptomatic patient with suspected myocardial contusion 总被引:4,自引:0,他引:4
M B Foil R C Mackersie S R Furst J W Davis M S Swanson D B Hoyt S R Shackford 《American journal of surgery》1990,160(6):638-42; discussion 642-3
Diagnostic criteria and guidelines for hospital admission for suspected myocardial contusion (MCC) remain unclear. This study defines and examines the clinical sequelae of patients admitted with a suspicion of MCC. Criteria for observation following isolated, minor blunt chest trauma are suggested. Hospital and trauma registry records of patients admitted over a 33-month period with suspected MCC were reviewed. Conventional evaluation criteria, cardiac-related complications, and associated injuries were analyzed for 524 patients. Twenty-eight cardiac-related complications occurred in 27 of 524 patients (5%). These complications included 23 dysrhythmias, 3 infarctions, and 2 pericardial effusions. There were 23 patients with abnormal admission electrocardiograms and 4 with normal ones. Of the latter, one patient developed dysrhythmia 4 hours after admission, and three had other major multi-system injuries requiring admission to the intensive care unit. The overall incidence of cardiac-related complications in minimally injured patients was 0.1%. There were no complications in patients with isolated chest wall contusions, a normal admission electrocardiogram, and a normal rhythm at 4 hours. There was no significant association between creatine phosphokinase isoenzymes or echocardiogram and cardiac-related complications. The complete absence of significant cardiac sequelae in patients with isolated chest wall contusion, normal admission and 4-hour electrocardiograms, and no other associated major injuries suggests that these patients need not be admitted. 相似文献
30.
A 60-year-old man with a history of diabetes insipidus presented with a left groin mass, leg edema, and retroperitoneal adenopathy. Biopsy results of the involved lymph nodes were typical of eosinophilic granuloma. The patient was treated with etoposide and prednisone and had a complete regression of his lymphadenopathy and edema. This response suggests that etoposide may be a useful agent in the management of histiocytosis X. 相似文献