首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1086123篇
  免费   102007篇
  国内免费   3588篇
耳鼻咽喉   15193篇
儿科学   36850篇
妇产科学   30589篇
基础医学   147314篇
口腔科学   32597篇
临床医学   114508篇
内科学   215453篇
皮肤病学   26029篇
神经病学   90042篇
特种医学   41613篇
外国民族医学   305篇
外科学   165775篇
综合类   23886篇
现状与发展   40篇
一般理论   390篇
预防医学   90065篇
眼科学   24592篇
药学   72799篇
  3篇
中国医学   2039篇
肿瘤学   61636篇
  2021年   9218篇
  2020年   9162篇
  2019年   9042篇
  2018年   16772篇
  2017年   14965篇
  2016年   16613篇
  2015年   17898篇
  2014年   23942篇
  2013年   33101篇
  2012年   32272篇
  2011年   33914篇
  2010年   24742篇
  2009年   25785篇
  2008年   31871篇
  2007年   32574篇
  2006年   34130篇
  2005年   31480篇
  2004年   30248篇
  2003年   28819篇
  2002年   27755篇
  2001年   48656篇
  2000年   49107篇
  1999年   41836篇
  1998年   13099篇
  1997年   11855篇
  1996年   11962篇
  1995年   11321篇
  1994年   10077篇
  1993年   9324篇
  1992年   32927篇
  1991年   32041篇
  1990年   31480篇
  1989年   30363篇
  1988年   27628篇
  1987年   27669篇
  1986年   25759篇
  1985年   24879篇
  1984年   18631篇
  1983年   15795篇
  1982年   9493篇
  1979年   16925篇
  1978年   12334篇
  1977年   10418篇
  1976年   9837篇
  1975年   10237篇
  1974年   12381篇
  1973年   11895篇
  1972年   10955篇
  1971年   10154篇
  1970年   9435篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Lyme disease presenting as urinary retention   总被引:1,自引:0,他引:1  
We report a case of Lyme disease that presented with urinary retention. The individual then experienced lower extremity paralysis. Paralysis and urinary retention resolved with intravenous ceftriaxone antibiotic. To our knowledge this is the first report of a urological manifestation as the initial clinical presentation of Lyme disease. Recognition of clinical symptoms and urological complications of Lyme disease also are discussed.  相似文献   
992.
Among the new techniques available for CyA monitoring, the FPIA offers the advantages of rapidity and simplicity. The present communication assesses the technical performance of this test in comparison with a 3H tracer-based PC-RIA for serum CyA levels using 971 samples obtained during the first 6 posttransplant months from 14 kidney transplant recipients. The FPIA evaluation included verification of CyA concentrations in manufacturer-supplied calibrators and controls by reference methods, determination of intraassay/interassay precision and accuracy, feasibility of specimen dilution and assessed assay sensitivity, and range of linearity. Comparison of FPIA with PC-RIA indicated that trough samples, when assessed by FPIA, averaged 1.3-fold greater than the PC-RIA, whereas non-trough FPIA measurements indicated similarity between the two methods. Although the two assays showed similar trends in most renal transplant recipients, two subjects demonstrated discrepancies, presumably reflecting the differing specificities of the polyclonal antibodies used in each assay. Thus, the FPIA appears to be a useful addition to CyA monitoring technology.  相似文献   
993.
The fate of the remaining bladder following supravesical diversion   总被引:1,自引:0,他引:1  
A retrospective study of 30 adults who underwent supravesical diversion for a variety of benign and malignant conditions was done with special attention to the fate of the residual bladder. Diversion was performed for diverse conditions, including radiation cystitis, cyclophosphamide cystitis, interstitial cystitis, incontinence and trauma. All groups experienced significant morbidity from the remaining in situ bladder. Over-all, 80% of the patients experienced at least 1 complication, chief among which were pyocystis (67%), hemorrhage (23%), severe pain (13%), and unremitting feelings of incomplete emptying and spasm (17%). Complications of sufficient severity to require rehospitalization occurred in 43% of the patients. Several patients required multiple rehospitalizations. Reoperation requiring general or regional anesthesia was necessary in 9 patients (30%) and included 4 cystectomies. Serious consideration should be given to performing primary cystectomy at the time of supravesical diversion in any patient in whom subsequent undiversion is not anticipated.  相似文献   
994.
A 67-year-old man with non-insulin-dependent diabetes mellitus progressively developed, over a 2-year period, lower extremity sensory and motor defects associated with impaired bladder function and perineal and perianal sensation related to a disease of the conus medullaris extending from T12 to S5. The magnetic resonance imaging scan suggested myelomalacia and the diagnosis of progressive necrotic myelopathy was confirmed by surgical intervention.  相似文献   
995.
Contact lens disinfection systems were evaluated for their effectiveness in killing Acanthamoeba castellanii and Acanthamoeba polyphaga trophozoites and cysts. Amoebae were inoculated into commercially available contact lens cleaning and soaking solutions. At intervals varying from 30 minutes to 24 hours, solutions were filtered. The filters were removed and cultured for Acanthamoeba organisms. Striking differences were observed in the abilities of the different disinfecting solutions to kill the organisms. Solutions containing chlorhexidine were effective at very short exposure times. Solutions containing benzalkonium chloride required slightly longer exposure times but were faster than solutions containing only thimerosal. Solutions containing sorbate, polyaminopropyl biguanide, or polyquaternium-1 were not effective at killing Acanthamoeba organisms in the time allotted for the experiment. Solutions containing hydrogen peroxide were quite effective if the agent was not prematurely catalyzed. A. polyphaga generally required longer exposure to disinfectants than did A. castellanii for complete inhibition to occur.  相似文献   
996.
INLANDER, CHARLES B., LEVIN, LOWELL B., AND WEINER, E.D. Medicine on Trial: The Appalling Story of Medical Ineptitude and the Arrogance that Overlooks It.  相似文献   
997.
998.
Blood volume, blood pressure, plasma concentrations of atrial natriuretic peptide (ANP), cyclic 3',5'-guanosine monophosphate (cGMP), angiotensin II, aldosterone, and arginine vasopressin (AVP), and urinary excretion rates of cGMP, sodium, and water were determined before and after infusion of human albumin 20%, 3.5 ml/kg body-weight to 12 patients with chronic glomerulonephritis and 19 healthy control subjects (Study 1); and before and after frusemide injection, 0.75 mg/kg to 15 patients with chronic glomerulonephritis and 19 healthy control subjects (Study 2). In Study 1 blood volume was expanded to the same degree in patients (8.8 and 7.5%, medians, after 90 and 180 min) and controls (8.6 and 6.1%). ANP was enhanced in the patients (5.9 to 11.0 pmol/l, P less than 0.01) and the controls (4.9 to 7.1 pmol/l, P less than 0.01), but the elevated level was protracted in the patients simultaneously with a delayed sodium excretion. Plasma cGMP increased, aldosterone decreased and AVP was unchanged in both groups, whereas angiotensin II decreased in the patients (P less than 0.01), but not in the controls. In Study 2 blood volume was reduced to a smaller extent in the patients than in the controls (8.9% versus 9.9%, P less than 0.05). ANP an cGMP decreased, and angiotensin II, aldosterone and AVP increased in both patients and controls. In conclusion, patients with glomerulonephritis respond to albumin- and frusemide induced changes in blood volume with essentially the same counter-regulatory changes in ANP, angiotensin II, aldosterone and AVP as do healthy subjects. The more protracted increase in ANP and the decrease in angiotensin II after albumin, and the smaller blood volume reduction after frusemide suggest an abnormal regulation of blood volume in glomerulonephritis.  相似文献   
999.
1000.
The pharmacokinetics and pharmacodynamics of the anticholinergic and calcium antagonistic drug terodiline, N-tert-butyl-1-methyl-3,3-diphenylpropylamine, have been studied in beagle dogs. The bioavailability was about 25% (0.15 and 0.5 mg/kg), the terminal half-life 3 hr, the systemic clearance 40 ml/min..kg, the volume of distribution (V beta) about 7 l/kg and the unbound fraction in serum 0.14. p-Hydroxyterodiline and p-hydroxy-m-methoxyterodiline were quantitated and constituted 15-40% and 25%, respectively, of the amount excreted in urine (about 60% of the dose) and were the main metabolites, as in man. The dog was used as an experimental model to study the chronotropic effect. An increased heart rate was observed after acute administration of high doses of terodiline as well as after p-hydroxyterodiline. A 20% increase in heart rate was observed at a mean serum concentration of 1086 and 1010 micrograms/l following intravenous injection of terodiline or p-hydroxyterodiline, respectively. The corresponding unbound concentrations were 150 and 474 micrograms/l. The potency ratios of terodiline/p-hydroxyterodiline was 0.9 +/- 0.2 (based on total concentrations) and 3.2 +/- 0.8 (based on unbound concentrations). The estimated potency of parent drug and main metabolite and the fact that p-hydroxyterodiline constitutes 10-20% of the terodiline steady-state level in man, indicate that the contribution of the metabolite to the chronotropic effect observed in clinical studies is minor.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号