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:      
  示例: 沙坡头地区,人工植被区,变化  检索词用空格隔开表示必须包含全部检索词,用“,”隔开表示只需满足任一检索词即可!
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   1937篇
  免费   47篇
  国内免费   8篇
耳鼻咽喉   28篇
儿科学   80篇
妇产科学   52篇
基础医学   337篇
口腔科学   71篇
临床医学   160篇
内科学   428篇
皮肤病学   41篇
神经病学   157篇
特种医学   48篇
外科学   114篇
综合类   6篇
一般理论   2篇
预防医学   83篇
眼科学   26篇
药学   183篇
中国医学   1篇
肿瘤学   175篇
  2024年   9篇
  2023年   11篇
  2022年   36篇
  2021年   63篇
  2020年   39篇
  2019年   58篇
  2018年   58篇
  2017年   45篇
  2016年   62篇
  2015年   59篇
  2014年   73篇
  2013年   105篇
  2012年   170篇
  2011年   185篇
  2010年   74篇
  2009年   97篇
  2008年   126篇
  2007年   145篇
  2006年   121篇
  2005年   121篇
  2004年   83篇
  2003年   66篇
  2002年   76篇
  2001年   12篇
  2000年   10篇
  1999年   7篇
  1998年   14篇
  1997年   6篇
  1996年   9篇
  1995年   7篇
  1994年   5篇
  1993年   2篇
  1992年   7篇
  1991年   4篇
  1990年   2篇
  1989年   2篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   3篇
  1983年   1篇
  1982年   4篇
  1981年   2篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
排序方式: 共有1992条查询结果,搜索用时 10 毫秒
61.
62.
63.
During this study, we have investigated in vitro activity of N-substituted-3-amino-5-oxo-4-phenyl-2,5-dihydro-1H-pyrazole-1-carbothioamide derivatives with N-ethyl, N-(4-metoxyphenyl) and N-cyclohexyl substituents against Gram-negative Haemophilus influenzae and H. parainfluenzae bacteria. A spectrophotometric assay was used in order to determine the bacterial growth and biofilm formation using a microtiter plate to estimate minimal inhibitory concentration (MIC) and minimal biofilm inhibitory concentration (MBIC). Among the tested N-substituted pyrazole derivatives, only N-ethyl-3-amino-5-oxo-4-phenyl-2,5-dihydro-1H-pyrazole-1-carbothioamide showed a significant in vitro activity against both planktonic cells of H. parainfluenzae (MIC = 0.49–31.25 μg ml?1) and H. influenzae (MIC = 0.24–31.25 μg ml?1) as well as biofilm-forming cells of H. parainfluenzae (MBIC = 0.24–31.25 μg ml?1) and H. influenzae (MBIC = 0.49 to ≥31.25 μg ml?1). The pyrazole compound exerted higher inhibitory effect both on the growth of planktonic cells and biofilm formation by penicillinase-positive and penicillinase-negative isolates of H. parainfluenzae than the activity of commonly used antibiotics such as ampicillin. No cytotoxicity of the tested compound in vitro at concentrations used was found. The tested pyrazole N-ethyl derivative could be considered as a compound for the design of agents active against both pathogenic H. influenzae and opportunistic H. parainfluenzae, showing also anti-biofilm activity. This appears important because biofilms are determinants of bacterial persistence in long-term and recurrent infections recalcitrant to standard therapy.  相似文献   
64.
Invasive mycoses represent a rare but severe complication following hemopoietic SCT (HSCT) in children. Their incidence is related to the type of donor, being higher after allogeneic transplant, especially from alternative donors. Moreover, the incidence of invasive mycoses varies in the different post transplant phases. Neutropenia, lymphopenia, GvHD, high-dose steroids or other immunosuppressive drugs represent well-known risk factors. The clinical features of invasive mycoses after HSCT in children are similar to those observed in adults, and the diagnostic tools, including Aspergillus galactomannan antigen detection, are feasible also in pediatrics. Mortality due to invasive mycoses after HSCT in children is high.  相似文献   
65.

Introduction

Recently several risk scores have been proposed that, beyond traditional risk factors, also include additional inflammatory biomarkers underlying atherothrombosis. The Reynolds Risk Score (RRS) is a point scale assessing the risk of cardiovascular events over 10 years, which takes into account for the first time high-sensitivity C-reactive protein. The aim of this study was to establish clinical usefulness of RRS in men with stable coronary artery disease and preserved left ventricular systolic function.

Material and Methods

In total, 119 symptomatic non-diabetic man (mean age 63.9±9.23) who were directed for an elective coronary arteriography were enrolled in the study. Clinical data were collected including the elevated heart rate ≥70 bpm/min, basic laboratory results, placental growth factor and results of coronary angiography. Patients were analyzed related to RRS: low risk <10% (n=50), moderate risk 10-19% (n=46) and high risk >20% (n=23).

Results

Opposite to high RRS patients, in the low risk group more often occurred marginal or none atherosclerotic coronary arteries (13% vs. 44%, P=0.0214). The findings have revealed the relationship between the higher risk score and the lower frequency of marginal or no atherosclerotic coronary arteries (OR=0.19, 95%CI 0.05–0.67).

Conclusions

The Reynolds Risk Score appears to be useful in men with stable coronary artery disease and preserved left ventricular systolic function in stratifying the severity of coronary atherosclerosis.  相似文献   
66.

Objective

The use of antibacterial photodynamic therapy (aPDT) additionally to scaling and root planing (SRP) has been shown to positively influence the clinical outcomes. However, at present, it is unknown to what extent aPDT may represent a potential alternative to the use of systemic antibiotics in nonsurgical periodontal therapy in patients with aggressive periodontitis (AP). The aim of this study was to evaluate the outcomes following nonsurgical periodontal therapy and additional use of either aPDT or amoxicillin and metronidazole (AB) in patients with AP.

Material and methods

Thirty-six patients with AP displaying at least three sites with pocket depth (PD) ≥6 mm were treated with SRP and either systemic administration of AB for 7 days or with two episodes of aPDT. The following clinical parameters were evaluated at baseline and at 6 months: plaque index (PI), bleeding on probing (BOP), PD, gingival recession (GR) and clinical attachment level (CAL).

Results

Thirty-five patients have completed the 6-month evaluation. At 6 months, mean PD was statistically significantly reduced in both groups (from 5.0?±?0.8 to 3.0?±?0.6 mm with AB and from 5.1?±?0.5 to 3.9?±?0.8 mm with aPDT (p?p?p?p?=?0.03). Both therapies resulted in statistically significant reductions in all parameters compared to baseline.

Conclusion

While both treatments resulted in statistically significant clinical improvements, AB showed statistically significantly higher PD reduction and lower number of pockets ≥7 mm compared to aPDT.

Clinical relevance

In patients with AP, the two times application of aPDT in conjunction with nonsurgical periodontal therapy cannot be considered an alternative to the systemic use of amoxicillin and metronidazole.  相似文献   
67.
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive organ-specific autoimmune disorder that is characterized by a variable combination of (i) chronic mucocutaneous candidiasis, (ii) polyendocrinopathy and/or hepatitis and (iii) dystrophy of the dental enamel and nails. We analyzed the AIRE (autoimmune regulator) gene in subjects who presented any symptom that has been associated with APECED, including candidiasis and autoimmune endocrinopathy. We observed that 83.3% of patients presented at least two of the three typical manifestations of APECED, while the remaining 16.7% of patients showed other signs of the disease. Analysis of the genetic diagnosis of these subjects revealed that a considerable delay occurs in the majority of patients between the appearance of symptoms and the diagnosis. Overall, the mean diagnostic delay in our patients was 10.2 years. These results suggest that molecular analysis of AIRE should be performed in patients with relapsing mucocutaneous candidiasis for early identification of APECED.  相似文献   
68.
69.
Background The impact of age on melanoma patient outcomes is uncertain. Objective The aim of the study was to analyze the characteristics and treatment outcomes in cutaneous melanoma patients ≥ 65 years of age with lymph node metastases. Methods We analyzed data from 849 consecutive patients with stage III cutaneous melanoma who were treated between 1994 and 2007 at one institution. Of these, 225 (26.5%) were ≥ 65 years of age. The characteristics and disease‐specific survival (DSS) from lymph node dissection (LND) date of patients ≥ 65 years of age were compared with those of younger patients. Median follow‐up time was 49 months (range: 6–140 months). Results In the ≥ 65 years group (51.6% men), the median Breslow thickness was 5.0 mm and 70% was ulcerated. The 5‐year DSS rate was significantly lower in older patients (34%). Multivariate analysis identified older age as an independent prognostic factor for DSS in the overall group. Independent negative prognostic factors of DSS in the group of older stage III patients were identified as features of nodal metastases (extracapsular invasion, HR = 1.74, P = 0.009; and ≥ 4 involved lymph nodes, HR = 1.5; P = 0.008) and male sex (HR = 1.5; P = 0.039). Conclusions This analysis showed that melanoma patients ≥ 65 years of age are characterized by a higher primary tumor stage and worse prognosis in the presence of regional node metastases than younger patients. Additionally, the results indicate that the same radical surgical therapy is necessary for patients ≥ 65 years old as in younger patients.  相似文献   
70.
Interleukin 6 (IL-6) plays an important role in the initiation and acceleration of chronic inflammation and could contribute to development of microvascular complications in patients with type 1 diabetes (DM1). Therefore, this study was aimed to investigate the association between concentration of IL-6 in relation to glucose control, lipid profile, and body mass index (BMI) in 69 DM1 patients subdivided according to the absence or presence of microvascular complications. BMI, level of fasting plasma glucose (FPG), and concentrations of total cholesterol (TCH), LDL cholesterol (LDL-C), and IL-6 were higher in DM1 patients compared to the control group. In DM1 patients, IL-6 concentration was positively correlated with level of FPG, LDL-C, TCH concentrations, and BMI. These correlations were stronger in the subgroup of patients with microvascular complications. In addition, BMI independently influences IL-6 concentration in DM1 patients. In conclusion, elevated IL-6 concentration is associated with diabetes-related variables which could accelerate progression of microvascular complications in DM1 patients.  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