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   1467篇
  免费   76篇
  国内免费   14篇
耳鼻咽喉   3篇
儿科学   62篇
妇产科学   22篇
基础医学   165篇
口腔科学   32篇
临床医学   217篇
内科学   316篇
皮肤病学   13篇
神经病学   49篇
特种医学   203篇
外科学   122篇
综合类   50篇
一般理论   1篇
预防医学   112篇
眼科学   6篇
药学   138篇
肿瘤学   46篇
  2018年   21篇
  2017年   13篇
  2016年   14篇
  2015年   20篇
  2014年   39篇
  2013年   42篇
  2012年   30篇
  2011年   47篇
  2010年   39篇
  2009年   39篇
  2008年   33篇
  2007年   50篇
  2006年   31篇
  2005年   36篇
  2004年   27篇
  2003年   41篇
  2002年   36篇
  2001年   35篇
  2000年   19篇
  1999年   40篇
  1998年   47篇
  1997年   52篇
  1996年   39篇
  1995年   43篇
  1994年   29篇
  1993年   27篇
  1992年   27篇
  1991年   31篇
  1990年   33篇
  1989年   35篇
  1988年   39篇
  1987年   37篇
  1986年   37篇
  1985年   35篇
  1984年   20篇
  1983年   17篇
  1982年   37篇
  1981年   17篇
  1980年   28篇
  1979年   15篇
  1978年   23篇
  1977年   33篇
  1976年   21篇
  1975年   15篇
  1974年   10篇
  1973年   12篇
  1972年   10篇
  1971年   10篇
  1969年   11篇
  1968年   14篇
排序方式: 共有1557条查询结果,搜索用时 15 毫秒
1.
2.
3.
The changes in bladder function occurring after a surgical alteration in bladder outflow resistance were studied in 20 males undergoing transurethral prostatectomy (TURP) and in 20 females undergoing an endoscopic bladder neck suspension (EBNS). Serial cystometrograms (CMG) were performed before operation, and on alternate days after spontaneous micturition was re-established, for 5 days in the males and for 21 days in the females. CMGs were repeated at 3 months and 1 year after operation. After TURP voiding pressures (Pdet) fell rapidly from a mean of 118 cm H2O before operation to 57 cm H2O at 5 days, with an increase in flow rate during this time from 10.5 ml/s to 24 ml/s. Detrusor instability that had been present in 14 patients resolved within 2 days in 12. There was no further significant urodynamic change over the 1-year study period. After EBNS, there was an early rise in voiding pressure (Pdet rose from 26 cm H2O before operation to 42 cm H2O at 3 days). This continued to increase up to 21 days particularly in those patients with initial large residuals. Three patients developed detrusor instability. Flow rates were greatly reduced at first (27 ml/s before operation and 13 ml/s at 3 days), and gradually increased in line with voiding pressures, yet were still diminished 1 year after operation. The urodynamic changes following a reduction in bladder outflow resistance by TURP are immediate and sustained and unlikely to be the result of structural changes within the bladder wall. EBNS produces an increase in outflow resistance and it can be several weeks before balanced voiding is achieved, with significantly increased detrusor pressures needed to achieve complete bladder emptying at a reduced flow rate.  相似文献   
4.
The morphologic subgroups of intraductal carcinoma in situ (DCIS) of the breast may be biologically different. Thirty-eight patients with comedo-type DCIS treated with local resection with or without radiotherapy are presented. Thirteen of 35 patients had a family history of breast cancer, with 11 patients having an affected first-degree relative. This is significantly increased over other series of breast cancer patients. Recurrence was ipsilateral in all patients and occurred at the site of the original disease. Recurrence occurred in 4 of 30 patients treated with local resection only and 2 of 8 treated with local resection plus radiotherapy. The length of mean follow-up was 39 months. Because of the paucity of studies, these results cannot be compared with others, but there does appear to be a significant incidence of local recurrence after resection for comedo-type DCIS. Immunohistochemical and oncogene studies as they relate to comedo-type DCIS are discussed.  相似文献   
5.
Bladder pain is a difficult symptom to manage. Epidural anaesthesia, which was used in 10 patients with sensory disorders, carries a low morbidity and helps to define those patients with severe bladder pain who might benefit from denervation procedures.  相似文献   
6.
Bottomley  PA; Lee  Y; Weiss  RG 《Radiology》1997,204(2):403
  相似文献   
7.
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   
8.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).  相似文献   
9.
At the Indiana University Medical Center, 99 patients with medically intractable complex partial seizures (MI-CPS) had presurgical evaluation with subsequent anterior temporal lobectomy. The majority of the patients had single photon emission tomography (SPECT) performed interictally as well as during an actual epileptic seizure (ictal scan). Decreased regional cerebral perfusion (rCP) was seen in 54/94 (57%) of the interictal scans corresponding to the eventual site of the surgery. However, ictal scans provided a higher yield; increased rCP in the temporal lobe during an actual seizure was observed in 60/82 (73%) concordant to the side of surgery. SPECT is a useful, noninvasive method of localizing the epilepti-form focus in patients with MI-CPS considered for resective surgery. Both interictal and ictal SPECT need to be performed; combined interictal hypo-perfusion and ictal hyperperfusion in the same focal area are unique to epileptogenic lesions. Ictal SPECT studies can be performed in the majority of patients during the period of continuous video/EEG monitoring with only a little additional effort. Combining the results of functional brain imaging (interictal and ictal SPECT, PET) with clinical semiology of seizures, surface and sphenoidal EEG, magnetic resonance imaging and other non-invasive tests, anterior temporal lobectomy can be recommended in approximately two-thirds of the patients without resorting to potentially dangerous intracranial EEG monitoring.  相似文献   
10.
Cyclosporin A (CyA) toxicity is a common occurrence in pediatric organ transplant patients. We hypothesized that reduced mdr1a expression in newborn and developing mice would affect CyA accumulation within organs and/or toxicity. For functional studies, CyA was administered (5 mg kg(-1) i.p.) to 1-, 12-, and 19-day, and adult male and female mdr1a+/+ and mdr1a-/- mice. Peak blood CyA was lower in 1-, 12-, and 19-day-old (1000 ng ml(-1)) versus adult (1500 ng ml(-1)) mice but was similar in mdr1a+/+ and mdr1a-/- mice. Kidney mdr1a expression (measured by quantitative polymerase chain reaction) increased 2.5-fold in 19-day-old male and female mice and increased another 4-fold in adult females compared with adult males. Liver mdr1a expression increased 6-fold by day 12 compared with neonatal mice. Thereafter, maintenance of hepatic mdr1a expression in females and a reduction to neonatal levels in males was observed. Kidney/blood (8- to 9-fold) and liver/blood (12- to 15-fold) CyA levels were highest on days 12 and 19 and were not dependent on maturational changes in mdr1a mRNA levels. Adults had higher brain expression of mdr1a mRNA (3-fold), a corresponding 5-fold increase in immunodetectable P-glycoprotein, and 80% lower brain accumulation of CyA compared with 1-day-old mice. Conversely, in mdr1a-null mice, brain/blood CyA was similar in newborn and adult mice. A similar pattern was observed for the brain accumulation of the mdr1a substrate 3H-digoxin. We conclude that the risk for central nervous system drug toxicity could be higher in neonates or young children as a consequence of underdeveloped P-glycoprotein.  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