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   9500篇
  免费   338篇
  国内免费   54篇
耳鼻咽喉   331篇
儿科学   387篇
妇产科学   441篇
基础医学   619篇
口腔科学   348篇
临床医学   786篇
内科学   2241篇
皮肤病学   142篇
神经病学   573篇
特种医学   394篇
外科学   2315篇
综合类   140篇
预防医学   187篇
眼科学   344篇
药学   346篇
中国医学   22篇
肿瘤学   276篇
  2024年   2篇
  2023年   81篇
  2022年   118篇
  2021年   263篇
  2020年   151篇
  2019年   178篇
  2018年   224篇
  2017年   191篇
  2016年   308篇
  2015年   347篇
  2014年   470篇
  2013年   569篇
  2012年   708篇
  2011年   664篇
  2010年   442篇
  2009年   450篇
  2008年   687篇
  2007年   777篇
  2006年   682篇
  2005年   682篇
  2004年   571篇
  2003年   496篇
  2002年   383篇
  2001年   87篇
  2000年   51篇
  1999年   47篇
  1998年   66篇
  1997年   41篇
  1996年   38篇
  1995年   24篇
  1994年   19篇
  1993年   11篇
  1992年   20篇
  1991年   10篇
  1990年   8篇
  1989年   3篇
  1988年   3篇
  1987年   2篇
  1986年   2篇
  1985年   4篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1980年   2篇
  1977年   1篇
  1974年   1篇
  1973年   1篇
  1970年   1篇
  1966年   1篇
排序方式: 共有9892条查询结果,搜索用时 15 毫秒
81.
Study Type – Therapy (case control) Level of Evidence 3b What's known on the subject? and What does the study add? Recently European Association of Urology 2011 guidelines on urolithiasis recommended retrograde intrarenal surgery as the second‐line therapy for the treatment of kidney stones <10 mm in diameter. This study shows that retrograde intrarenal surgery may be an alternative therapy to percutaneous nephrolithotomy, with acceptable efficacy and low morbidity for 2–4 cm stones.

OBJECTIVE

  • ? Currently, the indications for retrograde intrarenal surgery (RIRS) have been extended due to recent improvements in endoscopic technology. In this study, we compare the outcomes of percutaneous nephrolithotomy (PCNL) and RIRS in the treatment of 2–4 cm kidney stones.

MATERIALS AND METHODS

  • ? Between September 2008 and January 2011, 34 patients who had renal stones ranging from 2 to 4 cm in diameter were treated with RIRS. The outcomes of these patients were compared with patients who underwent PCNL using matched‐pair analysis (1:1 scenario).
  • ? The matching parameters were the size, number and location of the stones as well as age, gender, body mass index, solitary kidney, degree of hydronephrosis, presence of previous shock wave lithotripsy and open surgery.
  • ? Data were analysed using Fisher's exact test, Student's t test and the Mann–Whitney U test.

RESULTS

  • ? Stone‐free rates after one session were 73.5% and 91.2% for RIRS and PCNL respectively (P= 0.05). Stone‐free rate in the RIRS group improved to 88.2% after the second procedure.
  • ? Mean operation duration was 58.2 (±) 13.4 min in the RIRS group but 38.7 (±) 11.6 min in the PCNL group (P < 0.0001). Blood transfusions were required in two patients in the PCNL group.
  • ? Overall complication rates in the PCNL group were higher, but the differences were not statistically significant. Hospitalization time was significantly shorter in the RIRS group (30.0 + 37.4 vs 61.4 + 34.0 h, respectively; P < 0.001).

CONCLUSION

  • ? Satisfactory outcomes can be achieved with multi‐session RIRS in the treatment of 2–4 cm renal stones. RIRS can be used as an alternative treatment to PCNL in selected cases with larger renal stones.
  相似文献   
82.
83.
Pilonidal disease has been treated surgically and by various other methods for many years. The most important problem associated with such treatment is recurrence, but cosmetic outcome is another important issue that cannot be ignored. Today, crystallized phenol is recognized as a treatment option associated with good medical and cosmetic outcomes. We hypothesized that the addition of laser depilation to crystallized phenol treatment of pilonidal disease might increase the rate of success, and this study aimed to determine if the hypothesis was true. Patients who were treated with crystallized phenol and 755-nm alexandrite laser depilation were retrospectively analyzed. In total, 42 (31 male and 11 female) patients were treated with crystallized phenol and alexandrite laser depilation and were followed up between January 2009 and January 2012. In all, 38 patients (90.5%) had chronic disease and 4 (9.5%) had recurrent disease. Among the patients, 26 (61.9%) recovered following 1 crystallized phenol treatment, and the remaining patients had complete remission following repeated treatment. Some patients needed multiple treatments, even up to 8 times. None of the patients had a recurrence during a mean 24 months (range, 6–30 months) of follow-up. Whatever method of treatment is used for pilonidal disease, hair cleaning positively affects treatment outcome. The present results support the hypothesis that the addition of laser depilation (which provides more permanent and effective depilation than other methods) to crystallized phenol treatment (a non-radical, minimally invasive method associated with very good cosmetic results) can increase the effectiveness of the treatment and also reduce the recurrence rate of the disease.  相似文献   
84.
Skin defects on the finger tip, are commonly treated with skin grafts or flaps. Hidden areas are usually preferred as donor sites.In this study, skin over the dorsal aspect of the base of the injured finger or another finger in the same area is used as a donor site. Since the donor area can be hidden beneath a ring, it was named as the 'ring graft'. The skin elasticity over this area, allows a fairly large graft. This method was performed in defects of 27 patients involving 32 fingers. Donor sites were closed primarily without any tension.Results on follow-ups of the patients were satisfactory concerning colour and texture match of the graft. We recommend the 'ring graft' as a hidden alternative donor site for resurfacing of a finger in selected cases.  相似文献   
85.
Protective effect of quercetin on renal ischemia/reperfusion injury in rats   总被引:5,自引:0,他引:5  
BACKGROUND: There is increasing evidence to suggest that toxic oxygen radicals play a role in the pathogenesis of ischemia/reperfusion (I/R) injury in the kidney. The aim of this study was to evaluate whether quercetin, an oxygen free radical scavenger, protects kidney tissue. METHODS: A renal I/R injury was induced by a left renal pedicle occlusion by ischemia for 45 min, followed by 60 mins of reperfusion with contralateral nephrectomy in rats. The rats were pretreated intraperitoneally with a quercetin suspension (50 mg/kg) 60 min before the ischemia induction. Thiobarbituric acid reactive substances (TBARS), protein carbonyl content, tumor necrosis factor alpha (TNF-alpha), reduced glutathione (GSH) levels, myeloperoxidase (MPO) catalase (CAT) and superoxide dismutase (SOD) activities were determined in renal tissue. RESULTS: There were 3 groups of rats, the control group, the I/R group and the I/R+Q group. Our results indicate that TBARS, TNF-alpha levels, MPO activity and protein carbonyl content were significantly higher in the I/R group than those in the control group (p<0.05, p<0.01, p<0.01 and p<0.01, respectively). Quercetin administration significantly decreased these parameters (p<0.05, p<0.01, p<0.05 and p<0.01, respectively). GSH levels, SOD, and CAT activities significantly decreased after I/R injury when compared to the control group (p<0.01, p<0.05 and p<0.01, respectively). Quercetin treatment significantly increased GSH levels and activities of these enzymes when compared to the I/R group (p<0.05, p<0.01, p<0.05, respectively). CONCLUSIONS: These results suggest that quercetin reduces renal oxidative injury and facilitates repair. Quercetin can have a role in a renoprotective therapeutic regimen.  相似文献   
86.
Does sodium nitroprusside reduce lung injury under cardiopulmonary bypass?   总被引:4,自引:0,他引:4  
Objective: We hypothesized that direct pulmonary arterial infusion of sodium nitroprusside (SNP) would ameliorate lung injury under cardiopulmonary bypass. Methods: Experiments were performed on 12 adult mongrel dogs of both sexes weighing 20–28 kg. The animals were randomly divided into two groups of six animals each. All animals were subjected to total cardiopulmonary bypass (CPB) and moderate hypothermia (28°C core temperature). During total CPB, the aorta was clamped together with the pulmonary artery to prevent any antegrade flow to the lungs. After cardioplegic arrest for 120 min, the animals were rewarmed, weaned from CPB, and their condition stabilized for another 90 min. After the release of the aortic cross-clamp, the dogs received either a 5% glucose solution as a placebo (group I) or SNP (0.5 μg/kg per min) (group II), both infused into the pulmonary arterial line. The infusion was stopped after 60 min. To measure lung tissue malondialdehyde (MDA), water content and polymorphonuclear leukocytes count, lung tissue samples were taken before CPB and after weaning from CPB. In addition, alveolar-arterial oxygen difference (AaDO2) for tissue oxygenation was calculated by obtaining arterial blood gas samples. Results: Values of MDA before CPB of 42.0±5.3 nmol/g of tissue rose to 67.6±5.7 nmol/g of tissue after weaning from CPB in group I (P=0.028). In group II MDA values also increased from 43.1±4.3 to 52.4±5.7 nmol MDA/g of tissue after weaning from CPB (P=0.046). The MDA increase in group II after CPB was found to be significantly lower than that for group I (P=0.004). The wet-to-dry lung weight ratio in the sodium nitroprusside group was 5.1±0.2, significantly lower than in the control group (6.8±0.4), (P=0.01). AaDO2 increased significantly in group I (P=0.028). There was no statistically significant difference (P=0.065) between groups I and II. During histopathological examination it was observed that neutrophil counts in the lung parenchyma rose significantly after CPB in both groups. The increase in group I was significantly larger than that in group II (P<0.001). Conclusions: The results represented in our study indicate that pulmonary arterial infusion of sodium nitroprusside during reperfusion can reduce lung injury under cardiopulmonary bypass.  相似文献   
87.
The utilization of the metacarpal bones and interosseous muscles in the reconstruction of the hand should be based on the vascular anatomy of the metacarpal bones and the interosseous muscles. The authors studied the vascular anatomy of the metacarpal bones and the interosseous muscles to design a split metacarpal musculoosseous flap. Eighteen cadaveric hands from 9 cadavers were included in the study. The dorsal metacarpal arteries arise from the arch and course along the metacarpal bones closer to the ulnar borders of the bones supplying their periosteum through the muscular branches. Despite the indistinct pattern of muscular supply and anastomotic branches to the palmar surface, in all hands the arteries extend constantly along the metacarpal bone closer to the ulnar border. For defects or any pathology of the carpal bones, the metacarpal bones could be split at the ulnar border distally and a split metacarpal musculoosseous flap (based proximally depending on the dorsal metacarpal artery) could be performed (or based distally along with a distal intermetacarpal anastomosis).  相似文献   
88.
We aimed to evaluate whether the subtle metabolic cerebral changes are present in normal-appearing white matter on conventional MRI, in patients with acute brucellosis, by using MR spectroscopy (MRS). Sixteen patients with acute brucellosis and 13 healthy control subjects were investigated with conventional MRI and single-voxel MRS. Voxels were placed in normal-appearing parietal white matter (NAPWM). N-Acetyl aspartate (NAA)/creatine (Cr) and choline (Cho)/Cr ratios were calculated. There was no significant difference between the study subjects and the control group in NAA/Cr ratios obtained from NAPWM. However, the Cho/Cr ratios were significantly higher in patients with acute brucellosis compared to controls (p=0.01). MRS revealed metabolic changes in normal-appearing white matter of patients with brucellosis. Brucellosis may cause subtle cerebral alterations, which may only be discernible with MRS. Increased Cho/Cr ratio possibly represents an initial phase of inflammation and/or demyelination process of brucellosis.  相似文献   
89.
Surgery is a stressful experience. Many minor interventions have been shown to cause considerable anxiety in patients, but whether arthroscopy leads to such anxiety is not well-known. Methods for lowering perioperative anxiety have been sought and listening to music or watching a movie have been recommended. The method of permitting patients to watch their own endoscopy has been studied infrequently. Our aim in this study was to find out the effect of watching simultaneous arthroscopic views on postoperative anxiety. A total of 63 patients were randomly divided into two groups: those watching their own arthroscopy formed group W, while patients that were only verbally informed formed group NW. The mean age of patients in both groups were 33 and 34, respectively. Meniscal surgery was the most commonly performed procedure (49/63 patients). The patients filled in state scale of State-trait anxiety inventory (STAI) forms and the study questionnaire (SQ) prepared for this study, just before and after the arthroscopy. Group W had significantly lower postoperative scores of STAI-S, whole questionnaire (Q-score) and all but one of individual statements in SQ. Having a previous operation history did not affect STAI scores. Age and level of education was not correlated with any of the studied parameters either. The ratio of patients that were pleased with the arthroscopy experience in group W and NW were 94 and 63%, respectively. Watching live arthroscopic views has led to a significant decrease in postoperative anxiety and worries about the surgery and the postoperative period, while increasing overall understanding and satisfaction of the patient.  相似文献   
90.
OBJECTIVE: To review the clinical management of alveolar echinococcosis. DESIGN: A retrospective analysis. SETTING: A university-affiliated hospital in Turkey. PATIENTS: Forty patients treated for alveolar echinococcosis between 1987 and 2000. INTERVENTIONS: Curative resection followed by chemotherapy, or medical palliation with chemotherapy only. Palliative procedures such as bilioenteric or external drainage were done for cholestatic jaundice and liver abscess. OUTCOME MEASURES: Results of medical and surgical treatment. RESULTS: Seventeen patients had a resectable tumour and all underwent curative resection. Of the other 23 patients with nonresectable tumour, 11 underwent palliative surgical procedures such as bilioenteric or external drainage for cholestatic jaundice or liver abscess. All patients received long-term albendazole therapy. Four patients with nonresectable tumour died because of chronic liver failure. In a 6.5-year follow-up, there was no recurrence in patients who underwent curative resection. The efficacy of chemotherapy is limited in nonresectable disease. CONCLUSIONS: To increase the rate of early detection and curative resection, screening programs are essential. Research on new chemotherapeutic approaches should be made to improve survival in patients with nonresectable disease.  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