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   2017篇
  免费   108篇
  国内免费   15篇
耳鼻咽喉   29篇
儿科学   34篇
妇产科学   13篇
基础医学   252篇
口腔科学   292篇
临床医学   166篇
内科学   369篇
皮肤病学   29篇
神经病学   124篇
特种医学   82篇
外科学   260篇
综合类   22篇
一般理论   2篇
预防医学   170篇
眼科学   68篇
药学   117篇
中国医学   11篇
肿瘤学   100篇
  2023年   21篇
  2022年   39篇
  2021年   71篇
  2020年   44篇
  2019年   61篇
  2018年   73篇
  2017年   65篇
  2016年   58篇
  2015年   80篇
  2014年   108篇
  2013年   115篇
  2012年   147篇
  2011年   167篇
  2010年   86篇
  2009年   88篇
  2008年   131篇
  2007年   110篇
  2006年   100篇
  2005年   86篇
  2004年   82篇
  2003年   45篇
  2002年   32篇
  2001年   23篇
  2000年   30篇
  1999年   27篇
  1998年   18篇
  1997年   15篇
  1996年   7篇
  1995年   15篇
  1994年   10篇
  1993年   14篇
  1992年   21篇
  1991年   22篇
  1990年   9篇
  1989年   11篇
  1988年   14篇
  1987年   5篇
  1986年   5篇
  1985年   7篇
  1984年   4篇
  1983年   8篇
  1982年   4篇
  1980年   4篇
  1979年   7篇
  1978年   8篇
  1977年   4篇
  1976年   4篇
  1975年   7篇
  1974年   4篇
  1967年   4篇
排序方式: 共有2140条查询结果,搜索用时 15 毫秒
991.

OBJECTIVE

To compare the effectiveness, safety and tolerability of sildenafil and apomorphine in Brazilian patients with erectile dysfunction (ED) of various causes.

PATIENTS AND METHODS

In all, 108 patients (mean age 55 years, sd 11) and documented ED for ≥6 months were included in 12 centres in Brazil. The patients were initially followed for 2 weeks and then randomized to initial treatment with apomorphine or sildenafil, taken before sexual intercourse, no more than once a day. The initial dose (2 mg apomorphine and 50 mg sildenafil) could be adjusted (to 3 mg apomorphine, or to 25 or 100 mg for sildenafil) depending on the effectiveness and tolerability during the first 4 weeks of treatment. The patients were re‐evaluated after 8 weeks on treatment and, after a wash‐out period of 2 weeks (no treatment), received the other study drug (other than that received in the first phase), and then had the same procedures as in the first phase.

RESULTS

In all, 97 patients were evaluated for therapeutic effectiveness, the overall effectiveness being assessed using two questions; sildenafil had a significantly higher proportion of affirmative answers for both (P < 0.001). Likewise, the estimates for the mean (sd ) proportion of successful sexual intercourse, of 83.3 (4.7)% vs 40.3 (4.7)% and the total ED Inventory of Treatment Satisfaction score, of 86.7 (2.9) vs 56.9 (2.9) (P < 0.001) were higher for sildenafil. At the end of the study, 93.8% of the patients randomized to initial therapy with apomorphine declared a preference for sildenafil, and 81.3% of those initially treated with sildenafil declared a preference for that drug. The two drugs were well tolerated, and the main adverse events for apomorphine were nausea, vomiting, headache, taste perversion and dizziness; for sildenafil they were headache, flushing or vasodilatation, abdominal pain or dyspepsia and nasal congestion.

CONCLUSIONS

Sildenafil is more effective than apomorphine for treating ED, in the domains of erectile function, satisfaction with sexual intercourse and overall satisfaction, and was the drug preferred by most of the patients.  相似文献   
992.
PURPOSE: Several fixation techniques for distal interphalangeal (DIP) joint arthrodesis have been described, with good clinical results and complication rates between 10% and 20%. We propose an alternative technique and fixation method using a lateral approach and 1.3-mm plate and screws fixation. METHODS: Between March and September 2005, 11 patients, totaling 15 fingers, had DIP joint arthrodesis by the described technique. The indications were posttraumatic arthritis in 8 fingers, degenerative or rheumatoid arthritis in 5 fingers, and isolated flexor digitorum profundus tendon lesions in 2 fingers. Patients were analyzed for osseus union, pain relief, and functional mobility of the finger. RESULTS: Arthrodesis relieved pain and restored stability at the 12th week, on average, with osseous union in all patients. All patients maintained full proximal interphalangeal joint motion with pulp-to-palm distance of zero at 6 months of follow-up evaluation. There were no rotational or angular deformities, nail bed lesions, or skin complications. CONCLUSIONS: The lateral approach with plate and screws fixation is an option for DIP joint arthrodesis. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.  相似文献   
993.
The present study examined the effects of local injections of adrenaline (AD) or noradrenaline (NA) in equimolar doses (6, 20, and 60 nmol) into the median raphe nucleus (MRN) on ingestive and non-ingestive behaviors of free-feeding rats. The results showed that the treatment with AD at doses of 20 and 60 nmol increased food intake. While the hyperphagic response evoked by 60 nmol dose of AD was accompanied by a reduction of the latency to start feeding and an increase in the frequency of feeding, the 20 nmol dose of AD was unable to change these behavioral aspects of feeding response. The meal size and non-ingestive behaviors were not affected by AD treatment in the MRN. While water intake remained unchanged after the treatment with 20 nmol of AD in the MRN, this dose decreased the latency to start drinking. Feeding and drinking behaviors were not affected by treatment with NA in the MRN. These data suggest that adrenergic receptors of MRN participate in mechanisms that control food intake initiation or appetite. In addition, our results also indicate that the availability of energetic substrate could affect the adrenergic influence on MRN neurons since previous data indicated that the injection of AD into the MRN of food restricted rats decreased food intake.  相似文献   
994.
A technical innovation of a novel ureter implantation technique on rat kidney allograft transplantation is described. The left kidney graft is transplanted heterotopically into the left infrarenal position, using vascular conduits from donor abdominal aorta and inferior vena cava in continuity to renal vessels, to perform arterial and venous end-to-side anastomoses to the recipient vessels. A new ureter implantation technique was employed by placing a purse-string suture around the uretero-vesical anastomosis and ligated at the end of the anastomosis to invaginate the ureter and relieve tension at its junction to the bladder. This functions as an anti-reflux procedure, also preventing urine leakage. Bilateral native kidneys nephrectomy of the recipient was performed a week post-transplant. This model of rat kidney transplantation was associated with high survival rate (87%) 2 weeks post-transplant with no evidence of vascular anastomoses complications or other technical failures. The technique is easy, reliable, and can be routinely applied to other microvascular transplantation procedures.  相似文献   
995.
BACKGROUND AND PURPOSE: Laparoscopic partial nephrectomy (LPN) has been performed at several institutions using oxidized cellulose (OC) as a means of bleeding and urinary fistula (UF) prevention. However, a foreign-body reaction mimicking either abscess or tumor recurrence has been associated with the use of OC. We evaluated renal-defect healing after LPN with and without OC. MATERIALS AND METHODS: Sixteen female Landrace pigs underwent lower-pole excision; all the collecting systems were entered and then closed with absorbable running suture. In group 1, hemostatic U-shaped stitches were the only method of hemostasis. In group 2, a bolster of OC was added to the renal defect. The pigs were sacrificed at 1, 4, 7, or 21 days, and gross findings such as perirenal collection were observed. A catheter was advanced up to the kidney, and methylene blue was injected with collecting system pressure observation; burst pressure was defined as the appearance of extravasation. High risk for UF was defined as burst pressure <10 mm Hg. RESULTS: Neither hemorrhage nor urinoma was observed during sacrifice. One pig from group 2 had a burst pressure of 4 mm Hg At 7 days (high risk for UF). At 21 days in group 2, the tissue was grossly solid, apparently a granuloma. Suppuration tended to be greater in group 2. The foreign-body reaction was more intense in group 2 and was strongly present at 4, 7, and 21 days. CONCLUSIONS: The use of OC is associated with higher scores of suppuration and foreign-body reaction. After LPN with OC, postoperative day 7 might be a critical time for the development of urinary leakage.  相似文献   
996.
Second generation antipsychotics have less influence on prolactin levels than conventional antipsychotics (CA), which are commonly associated with sexual dysfunction and hyperprolactinaemia. However, only a few studies have been conducted assessing these newer antipsychotics and sexual function/dysfunction. The aim of this study is to evaluate the sexual function and hormonal profile of male schizophrenic patients taking olanzapine or CA. Sixty-three inpatients with acute episodes of schizophrenia were randomly assigned to take either olanzapine, or go on conventional antipsychotic treatment. The Dickson-Glazer sexual functioning questionnaire was used to assess sexual functioning where serum prolactin, luteinizing hormone, follicle-stimulating hormone, total testosterone, free testosterone, and sex hormone-binding globulin concentrations were measured. All measurements were taken on discharge from the inpatient unit (baseline), and again at 3 and 9 months after discharge. Prolactin levels in the olanzapine group decreased more rapidly and were significantly lower than in the CA group after 3 months (12.1+/-6.3 microg/l, p=0.01; 18.1+/-11.2 microg/l, p=0.564, respectively). After nine months, there was a tendency toward normal levels in both groups, and the frequency of sexual complaints did not differ between the groups. This study showed no difference between olanzapine and conventional antipsychotics regarding sexual complaints in the treatment of schizophrenia, but did show a difference in the hormone level normalization rate.  相似文献   
997.
998.
999.
Euphorbia tirucalli (Euphorbiaceae family), an environmental risk factor for Burkitt's lymphoma, also presents pharmacological activities. In the northeast region of Brazil its latex is used as an antimicrobial, antiparasitic in the treatment of coughs, rheumatism, cancer and other maladies as folk remedy. The present work concerns its developmental toxicity in rats. Wistar rats on the first day post-coitum (dpc) were grouped as control (distilled water) and treated (latex aqueous solution) groups. Animals were treated by oral gavage from the 1st to the 4th (Experiment I) and from the 5th to 7th dpc (Experiment II) and killed on the 5th or 14th dpc, respectively. Maternal variables were: clinical signs of toxicity, body weight, ovaries, liver and kidneys weight and number of corpora lutea. The uterine tubes and cornua were washed for counting and identification of embryos. The embryos and placenta were weighed. Apart from the leucopenia and the higher placental weight observed in treated rats from Experiment II, there were no significant differences between the groups. It is possible to conclude that the latex aqueous solution of Euphorbia tirucalli did not interfere with tubaric embryo development or with implantation, but it seems to alter the placenta morphology.  相似文献   
1000.
Endogenous Ca(2+)-activated Cl(-) currents (CaCCs) are abundant and present in very different cell types. Very good evidence has been provided that endogenous CaCC is produced by anoctamin 1 (Ano1) and Ano2. Insight into the physiological role of anoctamins has been provided for Ano1, Ano2 and Ano6; however, the physiological role of the other seven members of the anoctamin family remains obscure. Anoctamins 1 and 2 may operate as individual Ca(2+)-sensitive channel proteins or may require accessory subunits for complete function. We find that overexpressed Ano1 has properties resembling all those of endogenous CaCCs, although with some noticeable biophysical and regulatory differences when compared with endogenous channels. Apart from Ano1 and Ano2, expression of Ano6 also produces a Cl(-) conductance. Depending on the cellular background, Ano6 currents may have variable properties. Anoctamins 1 and 6 are frequent in epithelial cells, often coexpressed together with Ano8, Ano9 and Ano10. Most available data on anoctamins were obtained from mouse tissues and from cultured cells, which may not be representative of native human tissues.  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