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   445篇
  免费   18篇
  国内免费   1篇
耳鼻咽喉   17篇
儿科学   34篇
妇产科学   24篇
基础医学   25篇
口腔科学   42篇
临床医学   29篇
内科学   82篇
皮肤病学   29篇
神经病学   23篇
特种医学   44篇
外科学   56篇
综合类   1篇
预防医学   4篇
眼科学   28篇
药学   17篇
肿瘤学   9篇
  2023年   1篇
  2022年   8篇
  2021年   21篇
  2020年   16篇
  2019年   18篇
  2018年   16篇
  2017年   12篇
  2016年   15篇
  2015年   11篇
  2014年   20篇
  2013年   26篇
  2012年   32篇
  2011年   29篇
  2010年   13篇
  2009年   16篇
  2008年   31篇
  2007年   32篇
  2006年   36篇
  2005年   26篇
  2004年   26篇
  2003年   13篇
  2002年   13篇
  2001年   9篇
  2000年   5篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1994年   3篇
  1993年   3篇
  1992年   1篇
  1991年   5篇
  1990年   2篇
  1989年   1篇
排序方式: 共有464条查询结果,搜索用时 17 毫秒
101.
We studied the effects of the specific endothelin (ETA) receptor antagonist, BQ-123, on reperfusion injury in a rat model of kidney transplantation. First, Sprague-Dawley rats were divided into three groups: a sham nephrectomy (SNEPH), an autotransplantation (AUTO-Tx), and an allotransplantation (ALLO-Tx) group. In a fourth group, ALLO-Tx+BQ, allografts were flushed with 20 g BQ-123 containing cold Ringer's lactate before transplantation. For the allograft groups, kidneys from white Wistar albino rats were transplanted into allogeneic Sprague Dawley recipients. Grafts were allowed 120 min of reperfusion after 40 min of cold ischemia. ET-1,2 plasma concentrations in the renal venous blood, and kidney tissue prostaglandin (PG) E2 and leukotriene (LT) B4 levels were studied. Diene conjugates (DC), hydroxyalkanals (HAA), hydroxyalkenals (HAE) and malondialdehyde (MDA) levels, as the products of lipid peroxidation, and protein carbonyls (PC) and protein sulphydryls (PS), as the parameters of protein oxidation, were also analyzed in the kidney tissue. Plasma ET concentrations increased significantly in the AUTO-Tx and ALLO-Tx groups (P<0.05 and P<0.01, respectively) but this increase was reversed in the ALLO-Tx+BQ group. None of the lipid peroxidation products except DCs (P<0.05) increased in the AUTO-Tx group, whereas they all increased in the ALLO-Tx group (P<0.01). Protein oxidation parameters also changed significantly (P<0.01) in the ALLO-Tx group but did not in the AUTO-Tx group (P<0.05). The differences in PGE2 and LTB4 levels were not significant. Histopathologic examination revealed prominent glomerular and tubular injury in the AUTO-Tx and ALLO-Tx groups but less in the ALLO-Tx+BQ group. In the last group, all parameters of lipid peroxidation (P<0.001 for all) and PCs decreased, and PSs were preserved (P<0.001 for both) when compared with the AUTO-Tx and ALLO-Tx groups. We conclude that BQ-123, in addition to inhibiting the binding of ET-1,2 to the ETA receptor, may also inhibit the release and/or synthesis of ET-1,2 and prevent reperfusion injury in kidney transplantation.  相似文献   
102.
The aim of this study was to evaluate the efficacy and safety of fractional carbon dioxide laser for the treatment of acne scars. Thirty-one participants, 15 female and 16 male, whose mean age was 34.84 ± 10.94 years, were included in this prospective study. The study took place between 2012 and 2016. Participants were evaluated with the “ECCA Grading Scale” before the first session, 3 months (short-term evaluation) and 3 years after the last session (long-term evaluation). Participants received two or three treatment sessions at 4-week intervals, with a 10,600 nm fractional carbon dioxide laser with pulse energies ranging between 100 and 160 mJ, 120 spot type, 75–100 spot/cm2 density, and 30 W power. Self-assessments by the participants were done 3 months and 3 years after the last session. The mean ECCA score was 107.90 ± 39.38 before the first session, and 82.17 ± 36.23 at the time of short-term evaluation (p = 0.000). The grade of improvement at the short-term evaluation was as follows: no improvement, mild, moderate, and significant improvement for 7 (22.6%), 11 (35.5%), 9 (29%), and 4 (12.9%) of the participants, respectively. Regarding self-assessments, 80.6 and 61.3% of the participants rated themselves as having at least mild improvement at the short-term and the long-term follow-up periods, respectively. The results of this study suggest that fractional carbon dioxide laser is an efficient treatment option for acne scars. Furthermore, self-assessment results show that more than half of the participants still experience at least mild improvement at the end of 3 years.  相似文献   
103.
Background: Cigarette smoking is one of the most common addictions worldwide. Muslim smokers reduce the number of cigarettes they smoke during Ramadan due to the long fasting hours. Objectives: We aimed to share our experience in a smoking cessation clinic during Ramadan by analyzing the efficacy and adverse effects of once-daily dosing of bupropion or varenicline in a fasting group compared with conventional dosing in a non-fasting group. Methods: We analyzed 57 patients who attended our smoking cessation clinic during Ramadan of 2014 and 2015, and at least one follow-up visit. For the fasting patients, we prescribed bupropion or varenicline after dinner (once daily) as the maintenance therapy. We recorded demographic characteristics of the patients, fasting state, drugs taken for smoking cessation, and the dosage of the medication. At the first follow-up visit, adverse effects seen with the treatment were recorded. We conducted telephone interviews 6 months after the first visits of the patients to learn the current smoking status of the groups. Results: Of the total 57 patients, 20 (35.1%) were fasting and 37 (64.9%) were not fasting. Fasting and non-fasting patients were similar for sex, age, smoking pack-years, marital status, educational status, and mean Fagerström scores (p >.05). Adverse effects and quit rates after 6 months of follow-up were similar between the fasting and non-fasting groups (p >.05). Conclusion: Although our sample size was small, we found no difference in the rates of adverse effects or smoking cessation using a single daily oral dose of bupropion or varenicline between a fasting group and a non-fasting group that received conventional dosing.  相似文献   
104.
Randomized controlled trials are the gold standard in medical research, providing evidence of the efficacy of a treatment in well-defined patient populations. By contrast, real-world studies explore the effectiveness of treatments in routine clinical practice, often with diverse patient populations. Although both randomized controlled trials and real-world studies contribute to the understanding of the benefits and risks of therapies, they generate different types of data and serve complementary purposes. Real-world studies evaluating the management of neovascular age-related macular degeneration have shown that visual outcomes achieved with anti–vascular endothelial growth factor in clinical practice often differ from those derived from clinical trials, highlighting the importance of assessing such outcomes in real-world studies. Benefits include finding variations in treatment provision, leading to: service improvements; the understanding of the need for continued and higher than previously provided treatment frequency; and new treatment regimens such as treat-and-extend. There is potential for the scope of real-world studies to be expanded to include other patient outcomes, such as quality of life, thus providing decision-makers with additional information to complement the data collected in randomized controlled trials. Physicians, patients, and regulators stand to gain much from further development and the conduct of real-world studies. We provide an overview of the importance of real-world evidence in the management of neovascular age-related macular degeneration with anti–vascular endothelial growth factor therapy, describe sources of real-world evidence, and assess the relative strengths and limitations of randomized controlled trials and real-world studies.  相似文献   
105.
106.
Although the analgesic effect of sucrose on newborns is well established, little is known about whether these solutions are effective in reducing procedural pain in infants beyond the newborn period. The purpose of this study was to determine the effect of sucrose solution given orally on infant crying times and measure the distress in a 16–19-month age group. A total of 537 healthy, 16–19-month-old infants attending for their immunizations with intramuscular diphtheria, tetanus, and acellular pertussis (DTaP)/Haemophilus influenza type b/IPV (along with oral polio vaccination (OPV)), intramuscular pneumococcus and intramuscular hepatitis A were randomized to receive 2 mL of a 75 % sucrose solution, a 25 % sucrose solution or sterile water 2 min before injections. Infants receiving a 75 % sucrose solution had significantly reduced total crying times and Children’s Hospital of Eastern Ontario Pain Scale scores (CHEOPS) compared with infants in the control and 25 % sucrose solution groups (p?Conclusion: Sucrose solution reduces infant distress and is safe and clinically useful even for 16–19-month-old infants.  相似文献   
107.
Background: PCOS was reported to arise from the interaction of genetic and environmental factors. Some studies reported that women with PCOS have DNA damage and chromosome breakage. Such studies bring to mind the genes that are involved in DNA repairing. At present, several DNA repair genes and, as products of these genes, certain polymorphisms that alter the activity of proteins are known in the literature. The aim of this dissertation is to study the genomic instability that have been reported in PCOS cases along with the relationship between XRCC1 Arg194Trp, XRCC1 Arg399Gln, APE1 Asp148Glu, and XPD Lys751Gln polymorphisms in order to contribute to the pathogenesis of PCOS. Methods: Polymorphisms in DNA repair genes have been associated with the increased risk of various diseases and could also be related to the etiology of PCOS. Therefore, we conducted a study including 114 women with PCOS and 91 controls. These polymorphisms were determined by quantitative real time PCR and melting curve analysis using LightCycler. Results: Comparing the control groups at the end of the study, the results have not shown any statistically significant difference as far as XRCC1 Arg194Trp, XRCC1 Arg399Gln, and XPD Lys751Gln polymorphisms are concerned. However, there were notable differences between the groups in terms of APE1 Asp148Glu polymorphism. Associated with this condition, it has been noted that both mutant allele (Glu) frequency (37.72 % in the study group; 19.23% in the control group, p=0.0001) and homozygous mutant genotype (Glu/Glu) frequency (%12.28 in the study group; %6.60 in the control group, p=0.015) have been higher in the study group.  相似文献   
108.
109.
Aim: Our aim was to assess the incidence and risk factors of the puerperal genital hematomas (PGH).

Methods: We retrospectively reviewed recorded cases of PGH at Zekai Tahir Burak Research and Training Hospital, Ankara, Turkey, between January 2010 and 2014. Next three patients were chosen as control group.

Results: There were 47 cases of PGH with an incidence of 1 in 762 deliveries. Patients with PGH were younger, more likely to be nulliparous and had a greater weight gain during pregnancy than the control group. Patients with PGH had a longer first and second stage of labor than the control group. Mediolateral episiotomy and operative delivery were more frequently performed in patients with PGH than the control group. Neonates born to mothers with PGH were heavier than the control group (3525?±?428 versus 3325?±?579; p?=?0.031). In the logistic regression model, nulliparity (OR: 8.68, 95% CI?=?2.96–25.3), instrumental delivery (OR: 7.96, 95% CI?=?1.37–49.0) and mediolateral episiotomy (OR: 6.67, 95% CI?=?2.61–17.1) were factors which had an independent impact on risk of PGH.

Conclusions: Nulliparity, instrumental delivery and mediolateral episiotomy are the main risk factors for hematomas.  相似文献   
110.
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