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   2289篇
  免费   115篇
  国内免费   14篇
耳鼻咽喉   42篇
儿科学   85篇
妇产科学   32篇
基础医学   193篇
口腔科学   39篇
临床医学   178篇
内科学   541篇
皮肤病学   58篇
神经病学   191篇
特种医学   104篇
外科学   423篇
综合类   28篇
一般理论   3篇
预防医学   92篇
眼科学   63篇
药学   156篇
中国医学   5篇
肿瘤学   185篇
  2024年   4篇
  2023年   19篇
  2022年   44篇
  2021年   89篇
  2020年   50篇
  2019年   64篇
  2018年   89篇
  2017年   57篇
  2016年   60篇
  2015年   85篇
  2014年   123篇
  2013年   129篇
  2012年   208篇
  2011年   194篇
  2010年   132篇
  2009年   103篇
  2008年   157篇
  2007年   146篇
  2006年   135篇
  2005年   123篇
  2004年   90篇
  2003年   86篇
  2002年   71篇
  2001年   17篇
  2000年   18篇
  1999年   19篇
  1998年   14篇
  1997年   8篇
  1996年   6篇
  1995年   6篇
  1994年   12篇
  1993年   9篇
  1992年   2篇
  1991年   5篇
  1990年   3篇
  1989年   4篇
  1988年   1篇
  1987年   3篇
  1986年   3篇
  1985年   6篇
  1984年   8篇
  1983年   2篇
  1982年   2篇
  1981年   4篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1976年   1篇
  1961年   3篇
排序方式: 共有2418条查询结果,搜索用时 15 毫秒
991.
The pulmonary-renal cascade may regulate the respiration and skeletal muscle contractility. To evaluate this working hypothetical model, we conducted experiments to ascertain the skeletal muscle tone of the Swiss mice (20-35 g). The animals were evaluated for their skeletal muscle tone via several techniques i.e. inclined plane test, grip strength test and swim test. Groups of mice (n=6) were pre-treated with mefenamic acid (60 mg/kg, i.p), carbenoxolone (100 mg/kg i.p) or vehicle only 15 minutes before the treatment with heparin (500 U/kg, i.v), urokinase (5500 U/kg, i.v) and erythropoietin (150 U/kg, i.v). Heparin potentiated the loss of skeletal muscle tone induced by mefenamic acid and carbenoxolone while urokinase & erythropoietin significantly enhanced the skeletal muscle tone as evaluated by all or one of the tests. Other groups of mice (n=6) were pretreated with mefenamic acid (1 mg i.c.v), carbenoxolone (160 microg i.c.v) or minoxidil (30 microg i.c.v) and the effects of heparin & urokinase and erythropoietin on skeletal muscle tone were evaluated. To study the effects of heparin and urokinase on nerve regeneration, two groups of mice underwent a sham and sciatic nerve crush procedure. The mice treated with urokinase recovered much faster as compared to those treated with heparin or saline. These experimental results suggest that gap junction blockers and potassium channel openers interact with heparin, urokinase and erythropoietin to control the skeletal muscle tone.  相似文献   
992.
Based on reports of synergism between adriamycin and radiation therapy in experimental systems, a trial was initiated testing this combination in 53 adult patients with various advanced malignancies, especially sarcomas. Since studies have suggested a selective sensitization of hypoxic cells when this drug is given prior to radiation, an injection of low-dose adriamycin was given 90 min before radiation. This treatment was repeated every 7 days. The combination was most effective in the 30 patients with soft-tissue sarcomas, with 62% of these patients having partial or complete responses. Responses were less good in patients with gastric adenocarcinoma or with other tumors. The toxicity of the combined treatment was moderate. Further trials of this combination are warranted.  相似文献   
993.
BACKGROUND: Accurate measurement of renal function is important for the diagnosis, stratification and management of kidney disease. As the use of recommended filtration markers is limited by cumbersome and costly techniques, renal function is typically estimated by using various specifically derived prediction equations. Most of these equations have been derived from Caucasian patients suffering from varying degrees of chronic kidney disease. This study considers the validity of these equations in an Indian population without known kidney disease. METHODS: One hundred and twenty-two consecutive renal donors who had undergone 99mTc-diethylenetriaminepentaaceticacid (DTPA) glomerular filtration rate (GFR) estimation were enrolled. The predictive capabilities of the Cockcroft and Gault equation for creatinine clearance corrected for body surface area (CG-CrCl), CG-CrCl corrected for GFR (CG-GFR), modification of diet in renal disease (MDRD) 1, MDRD 2 and 24-hr urinary creatinine clearance (urine-CrCl) were evaluated with DTPA GFR as measured GFR. RESULTS: The mean age of the study population was 44.7 yrs with 72.2% being female). The mean measured DTPA GFR was 83.42 ml/min with a range of 61-130 ml/min. The median % absolute difference between the calculated and measured GFR was 19.7, 15.4, 19.3, 20.8 and 25.5, respectively, for CG-CrCl, CG-GFR, MDRD 1, MDRD 2 and urine-CrCl. Pearson's correlation between the measured and estimated GFR varied from 0.09-0.27. The precision as reflected by R2 value was 0.05 for CG-CrCl and CG-GFR, 0.06 for MDRD 1 and MDRD 2 and 0.01 for urine-CrCl. The bias was -14.14, 1.46, 11.89, 17.70 and -2.80 for CG-CrCl, CG-GFR, MDRD 1, MDRD 2 and urine-CrCl, respectively. The accuracy within 30% was 71.3, 85, 86, 76 and 69% for CG-CrCl, CG-GFR, MDRD 1, MDRD 2 and urine-CrCl, respectively. CONCLUSIONS: Our results from a healthy Indian population suggest that of all the predictive equations, MDRD 1 and MDRD 2 were the most precise, MDRD 1 the most accurate and CG-GFR the least biased. However, the poor correlation and error level exhibited by these equations makes them sub-optimal for clinical use.  相似文献   
994.
Membrane surgery and nanosurgical cell isolation using high-intensity femtosecond laser pulses is reported. We demonstrate the applicability of using ultrashort (femtosecond) laser pulses for performing surgery on live mammalian cells. When sub-10 femtosecond pulses were focused onto the cell, precise sub-micron surgical cuts were made on the biological membrane. Traversing the cells relative to the focused laser spot, we report on localized nanosurgical ablation of focal adhesion adjoining epithelial cells. In each study, the surgery was conducted without morphologically compromising the cells.  相似文献   
995.
Fibrillary Glomerulonephritis (FGN) is a rare clinical entity presenting in majority of patients with nephrotic range proteinuria, microscopic hematuria, impaired renal function and hypertension. The mean age of presentation is reported to be beyond 50 years with 50 patients developing end stage renal disease within a few years. A 28-year-old female presented to us with non-nephrotic range proteinuria, rapidly progressive renal failure (RPRF), microscopic hematuria and mild hypertension. The patient had undergone a renal biopsy at a peripheral center, which was reported as membranoproliferative glomerulonephritis (MPGN) and was being treated with steroids without any benefit. The patient on re-biopsy at our center was diagnosed as FGN on electron microscopy (EM). The patient responded to intravenous pulse methylprednislone and oral cyclophosphamide and is off dialysis for 10 months now. This case highlights the varied clinical and histological presentations of FGN which makes the disease difficult to diagnose more so, in a country like ours where EM is available in only a few centers. An accurate diagnosis aided by high index of clinical suspicion and EM can help in the initiation of appropriate therapy, thereby improving the outcome in this disease which otherwise has a poor prognosis.  相似文献   
996.
BACKGROUND: Susceptibility to infections is a major cause of high morbidity and mortality in patients with chronic kidney disease (CKD). Polymorphonuclear leukocytes (PMNs) play a major role in the host defense against various infections. Although the phagocytic function of PMNs in uremic patients has been subjected to repeated evaluation, results have been inconsistent. Also, the effects of progressive uremia and acute hemodialysis (HD) on polymorphonuclear function have been scarcely evaluated. METHODS: In this study, we assessed the phagocytic index (PI) of PMNs following their uptake of IgG-coated sheep erythrocytes in patients with varying severity of CKD and in healthy controls. In patients with advanced renal failure, the effects of acute HD on PI pre- and post-HD were also studied. RESULTS: A total of 30 patients with CKD and 15 healthy controls were studied. Patients with CKD were categorized into two groups: mild to moderate renal failure (S. Creatinine 2-6 mg/dL) and advanced renal failure (S. Creatinine >6 mg/dL) (n=15 for each). All three groups were age and sex matched. Patients with advanced renal failure had significantly impaired PI (4.03 +/- 1.15) as compared to patients with mild to moderate renal failure (7.17 +/- 2.62) and normal controls (8.13 +/- 3.31) (p < 0.001 for both). There was a statistically insignificant decline in the PI in patients with mild to moderate RF when compared to controls (7.17 +/- 2.62 versus 8.13 +/- 3.31). In patients with advanced renal failure, acute HD led to a significant improvement in PI (5.52 +/- 1.55 versus 4.03 +/- 1.15, p < 0.01). CONCLUSION: In patients with CKD, there is a progressive decline in the phagocytic index of the PMNs with increasing severity of uremia. Significant improvement in the phagocytic index following acute hemodialysis suggests the role of a circulating uremic toxin in this PMN dysfunction.  相似文献   
997.
998.
Metallic iris intra ocular foreign body (IOFBs) with minimal ocular damage pose an interventional challenge. We report safe removal of metallic intraocular foreign bodies embedded on the iris, in three cases by use of intraocular magnets. Two eyes had a clear lens with best corrected visual acuity (BCVA) of 20/20, while the third eye had a BCVA of 20/200 with siderotic cataract. Ultrasound biomicroscopy confirmed the superficial impaction of IOFB into the iris. Foreign bodies were successfully removed via the limbal route with a 20 g intravitreal magnet atraumatically in all 3 cases with preservation of their pre-operative BCVA. Case series highlights the usefulness and safety of intraocular magnet for removal of metallic iris foreign bodies in selected cases. Prior ultrasound biomicroscopy to know the actual depth of penetration of IOFB into the iris and preoperative confirmation of magnetic property of IOFB are essential.  相似文献   
999.
A 24-year-old man presented with a large right frontal epidural epidermoid cyst that resulted in right hypoglobus and right upper eyelid ptosis. CT and MRI revealed a bone-destroying mass involving the right frontal bone and eroding through the right orbital roof. Complete surgical removal was performed through a frontal craniotomy. After surgery, there was near-complete resolution of the hypoglobus and ptosis.  相似文献   
1000.
PURPOSE: In a prospective manner we studied various factors affecting fluid absorption during HoLEP. We also simultaneously evaluated changes in serum electrolytes and hemoglobin decrease during HoLEP. MATERIALS AND METHODS: This prospective study comprised of 53 patients who underwent HoLEP at our institute. Irrigation fluid was normal saline tagged with ethanol (1% w/v). Intraoperatively a standard breath analyzer was used to monitor expired breath ethanol levels during the procedure at 10-minute intervals. Patients who absorbed irrigating fluid as indicated by positive intraoperative breath tests were considered absorbers. Serum electrolyte and hemoglobin estimations were done before and after surgery. Total irrigation time, amount of irrigation fluid used, weight of resected tissue and presence of capsular perforation were recorded. Statistical analysis was performed to observe the effects of various factors on the amount of intraoperative fluid absorption. RESULTS: Of 53 patients studied 14 (26.41%) demonstrated fluid absorption in the range of 213 to 930 ml (mean 459). Preoperative prostate weight, total irrigation time, amount of irrigation fluid used and resected tissue weight were all significantly greater in absorbers. Similarly, absorbers had a statistically significant decrease in hemoglobin level postoperatively. There was no statistically significant change in serum electrolytes between absorbers and nonabsorbers. CONCLUSIONS: Preoperative weight of prostate, total irrigation time, amount of irrigation fluid used and weight of resected tissue all directly influence the amount of fluid absorption during HoLEP. There is no significant change in serum electrolytes and no risk of the transurethral resection syndrome.  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