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   4282篇
  免费   574篇
  国内免费   166篇
耳鼻咽喉   57篇
儿科学   143篇
妇产科学   69篇
基础医学   1046篇
口腔科学   66篇
临床医学   226篇
内科学   639篇
皮肤病学   110篇
神经病学   338篇
特种医学   59篇
外国民族医学   2篇
外科学   534篇
综合类   541篇
预防医学   110篇
眼科学   37篇
药学   371篇
中国医学   205篇
肿瘤学   469篇
  2024年   8篇
  2023年   79篇
  2022年   94篇
  2021年   179篇
  2020年   172篇
  2019年   267篇
  2018年   292篇
  2017年   258篇
  2016年   246篇
  2015年   236篇
  2014年   305篇
  2013年   275篇
  2012年   223篇
  2011年   297篇
  2010年   208篇
  2009年   199篇
  2008年   188篇
  2007年   163篇
  2006年   167篇
  2005年   163篇
  2004年   111篇
  2003年   102篇
  2002年   71篇
  2001年   61篇
  2000年   56篇
  1999年   47篇
  1998年   34篇
  1997年   20篇
  1996年   27篇
  1995年   48篇
  1994年   22篇
  1993年   36篇
  1992年   22篇
  1991年   20篇
  1990年   13篇
  1989年   13篇
  1987年   10篇
  1986年   15篇
  1985年   25篇
  1984年   47篇
  1983年   23篇
  1982年   31篇
  1981年   21篇
  1980年   28篇
  1979年   24篇
  1978年   25篇
  1977年   15篇
  1976年   7篇
  1975年   10篇
  1974年   9篇
排序方式: 共有5022条查询结果,搜索用时 109 毫秒
51.

Aim

To be able to calculate the potential of organ donation from deceased donors in a single hospital, region, and country, it is necessary to develop a useful stratification system for all hospitals taking into account their characteristics in having or not having departments crucial for donor identification and recruitment, such as an intensive care unit (ICU or neurology and neurosurgery departments), number of beds, and patient profiles (pediatric vs adult).

Materials and Methods

There are 1032 hospitals in Poland, and 388 have facilities and tools to confirm death according to neurological criteria. These hospitals with the potential of deceased donation were characterized accordingly to the criteria presented above.

Results

The largest group of institutions were first-degree referral hospitals having ICUs only for adults (161 hospitals), followed by hospitals with ICU and stroke departments for adults (76), then hospitals for adults with ICU and neurological department with no stroke beds (25), and hospitals for adults with second-degree referral and with ICU, stroke departments, and neurosurgery. In the case of pediatric patients and possible pediatric organ donation, the largest group consisted of 5 hospitals with pediatric ICU, pediatric neurology, and pediatric neurosurgery units. The remaining hospitals were unique in the country range.An exemplary analysis of 1 of the 40 stratified groups (19 out of 388 hospitals) showed that differences in actual activity in the donation process between similar hospitals are significant (from 0 to 62 donations in a 3-year period).

Conclusion

We believe the results of this study are fundamental for the calculation of potential donation in the country. Our thesis is that hospitals from the same group should have the same potential and should be active in donation process on the same level. Formal comparative analysis of historical data on donor referral from active and nonactive hospitals will allow us to estimate the lost numbers of possible donations and will help focus efforts to improve transplantation systems.  相似文献   
52.
53.

Objective

Lower extremity bypass (LEB) operations have high rates of surgical site infections (SSI). Phenylephrine is a commonly used vasoconstrictor which may reduce skin blood flow and increase the likelihood of SSI in these patients. We studied the potential effect of phenylephrine infusion during LEB surgery on SSI.

Methods

LEB cases and their demographic data were identified through the Vascular Quality Initiative registry. SSI in this population was identified using the hospital epidemiology surveillance database. Phenylephrine use in this population was identified through chart review.

Results

We identified 699 patients who underwent LEB; 82 (11.7%) developed an SSI, and 244 of 698 (35.0%) were treated with phenylephrine infusion. In bivariate analysis, higher body mass index (28.8 kg/m2 vs 27.3 kg/m2; P = .034), diabetes (14.6% vs 9.4%; P = .035), hypertension (12.6% vs 4.7%; P = .038), groin incision (13.2 vs 5.4%; P = .013) and longer procedure times (17.1% for >220 minutes and 8.9% for ≤220 minutes; P = .003) were associated with higher rates of SSI. Whereas phenylephrine infusion exhibited a trend toward a higher rate (14.8% vs 9.9%; P = .057). In the logistic regression model, diabetes (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.0-3.2; P = .032), total procedure time (OR, 1.85; 95% CI, 1.1-3.1; P = .026) and vertical groin incision (OR, 2.6; 95% CI, 1.1-6.5; P = .035) were independent predictors of increased SSI rates, whereas body mass index (OR, 1.04; 95% CI, 0.99-1.08; P = .09), hypertension (OR, 2.5; 95% CI, 0.6-10.9; P = .22), and phenylephrine infusion (OR, 1.08; 95% CI, 0.63-1.85; P = .78) were not independent predictors of increased SSI rates.

Conclusions

Phenylephrine infusion did not increase the risk of SSI in patients who underwent LEB.  相似文献   
54.
目的 探讨中药金芪灌洗液对慢性鼻-鼻窦炎(CRS)模型白兔鼻黏膜组织miRNA-155-3p表达的影响。方法 从慢性鼻-鼻窦炎患者的鼻腔分泌物中单独分离出金黄色葡萄球菌菌株,培养后收集菌落并稀释至1.0×1011 cfu/L混悬液,通过手术方式移植到白兔的鼻腔内,复制慢性鼻-鼻窦炎动物模型。将实验白兔随机分为空白组、模型组、庆大霉素组、金芪灌洗液组,每组6只。各组白兔给予相应干预,观察2周后处死取材。采用实时荧光定量聚合酶链反应检测miRNA-155-3p的表达,HE染色观察各组鼻黏膜炎症及结构的变化。结果 模型组、庆大霉素组miRNA-155-3p相对表达量较空白组升高(P <0.05),金芪灌洗液组较空白组降低(P <0.05),金芪灌洗液组miRNA-155-3p相对表达量较模型组降低(P <0.05),庆大霉素组较模型组升高(P <0.05),金芪灌洗液组miRNA-155-3p相对表达量较庆大霉素组降低(P <0.05)。白兔鼻窦黏膜形态学改变显示金芪灌洗液组黏膜形态趋于正常。结论 金芪灌洗液可抑制miRNA-155-3p的表达,起到抗炎作用并修复白兔损伤的鼻黏膜。  相似文献   
55.
目的:探讨血清糖类抗原125(CA125)、微小RNA-139-5p(miRNA-139-5p)、微小RNA-15a(miRNA-15a)水平检测在卵巢癌患者中的临床意义。方法:选取74例卵巢癌患者作为卵巢癌组,选取同期74名该院健康体检者作为对照组,比较卵巢癌组与对照组、不同分化程度卵巢癌患者、不同病理分期卵巢癌患者血清CA125、miRNA-139-5p、miRNA-15a水平,分析血清CA125、miRNA-139-5p、miRNA-15a水平与卵巢癌分化程度和病理分期的相关性。结果:卵巢癌组CA125、miRNA-139-5p水平均高于对照组,miRNA-15a水平低于对照组,差异有统计学意义(P<0.05);卵巢癌低分化患者血清CA125、miRNA-139-5p水平均高于中分化和高分化患者,且中分化患者高于高分化患者;卵巢癌低分化患者miRNA-15a水平低于中分化和高分化患者,且中分化患者低于高分化患者,差异有统计学意义(P<0.05);卵巢癌患者血清CA125、miRNA-139-5p水平随着病理分期升高而升高,即Ⅰ期<Ⅱ期<Ⅲ期<Ⅳ期,卵巢癌患者miRNA-15a水平随着病理分期升高而降低,即Ⅰ期>Ⅱ期>Ⅲ期>Ⅳ期,差异有统计学意义(P<0.05);Pearson相关性分析结果显示,CA125、miRNA-139-5p水平与卵巢癌分化程度呈负相关,与病理分期呈正相关,miRNA-15a水平与卵巢癌分化程度呈正相关,与病理分期呈负相关(P<0.05)。结论:卵巢癌患者血清CA125、miRNA-139-5p水平升高,miRNA-15a水平降低,且与卵巢癌分化程度、病理分期存在相关性,血清CA125、miRNA-139-5p、miRNA-15a水平可为临床卵巢癌患者诊治提供参考依据。  相似文献   
56.
The existing therapies of IgA nephropathy are unsatisfying. Acteoside, the main component of Rehmannia glutinosa with anti-inflammatory and anti-immune effects, can improve urinary protein excretion and immune disorder. Th22 cell is involved in IgA nephropathy progression. This study was determined to explore the effect of acteoside on mesangial injury underlying Th22 cell disorder in IgA nephropathy. Serum Th22 cells and urine total protein of patients with IgA nephropathy were measured before and after six months treatment of Rehmannia glutinosa acteoside or valsartan. Chemotactic assay and co-culture assay were performed to investigate the effect of acteoside on Th22 cell chemotaxis and differentiation. The expression of CCL20, CCL22 and CCL27 were analyzed. To explore the effect of acteoside on mesangial cell injury induced by inflammation, IL-1, IL-6, TNF-α and TGF-β1 were tested. Results showed that the proteinuria and Th22 lymphocytosis of patients with IgA nephropathy significantly improved after combination treatment of Rehmannia glutinosa acteoside and valsartan, compared with valsartan monotherapy. In vitro study further demonstrated that acteoside inhibit Th22 cell chemotaxis by suppressing the production of Th22 cell attractive chemokines, i.e., CCL20, CCL22 and CCL27. In addition, acteoside inhibited the Th22 cell proliferation. Co-culture assay proved that acteoside could relieve the overexpression of pro-inflammatory cytokines, and prevent the synthesis of TGF-β1. TGF-β1 level in mesangial cells was positively correlated with the Th22 cell. This research demonstrated that acteoside can alleviate mesangial cell inflammatory injury by modulating Th22 lymphocytes chemotaxis and proliferation.  相似文献   
57.

Background

The Great East Japan Earthquake (GEJE) and Tsunami devastated the northeastern coast of Japan on March 11, 2011. This study aimed to determine whether sociopsychological factors, such as sleep disturbance and psychological distress, influenced new-onset subjective knee pain in survivors during the post-disaster phase of the GEJE.

Methods

From November 2012 to February 2013 (2 years after the GEJE) and from November 2013 to February 2014 (3 years after the GEJE), survivors (≥18 years) completed self-reported questionnaires. A total of 1470 survivors responded to the questionnaires and were included in this study. New-onset subjective knee pain was defined as knee pain by encircled response absent at 2 years but present at 3 years after the GEJE. Two years after the GEJE, ≥10/24 points on the Kessler Psychological Distress Scale, and ≥6/24 points on the Athens Insomnia Scale defined the presence of psychological distress and sleep disturbance, respectively. Multiple logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI) of the association between new-onset subjective knee pain and psychological distress or sleep disturbance.

Results

Among the participants, 10.9% (160/1470) reported experiencing new-onset subjective knee pain. Sleep disturbance was significantly associated with new-onset subjective knee pain (OR, 1.57, 95% CI, 1.08–2.29, P = 0.017); however, psychological distress was not (OR, 1.07, 95% CI, 0.65–1.78, P = 0.80).

Conclusions

This is the first study to indicate an association between sleep disturbance and new-onset subjective knee pain among survivors of the GEJE. 247/300.  相似文献   
58.
59.

Background

It remains unclear whether early surgical intervention can reduce mortality after surgery in hip fracture patients. The aim of this study was to investigate the association between time from injury to surgery and mortality rate within 90 days after hip fracture surgery.

Methods

We retrospectively identified 1827 patients who underwent hip fracture surgery in a tertiary care center in Japan between April 2007 and March 2017. After applying exclusion criteria (patients with spontaneous fracture, multiple fractures, revision surgery, total hip arthroplasty, or a refusal to participate), 1734 patients were included. We extracted data concerning patients’ age, race, sex, operative procedure, American Society of Anesthesiologists (ASA) score, days from injury to surgery (injury-surgery days), and days from admission to surgery (admission-surgery days), which could affect 90-day mortality after surgery. Variables associated with 90-day mortality were determined using multivariate logistic regression analysis.

Results

The 90-day postoperative mortality rate was 3.5% (60 of 1734). Multivariable analysis showed that injury-surgery days were not associated with 90-day mortality (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.80 to 1.05; P = 0.19), and that older age (OR, 1.06; 95% CI, 1.02 to 1.10; P = 0.005), male sex (OR, 3.62; 95% CI, 1.86 to 7.03; P < 0.001) and high ASA score (OR, 2.10; 95% CI, 1.06 to 4.18; P = 0.034) significantly increased 90-day mortality. In addition, admission-surgery days were not associated with 90-day mortality (OR, 0.95; 95% CI, 0.83 to 1.09; P = 0.45).

Conclusion

Our results demonstrated that time from injury to surgery was not associated with mortality within 90 days after surgery after adjusting for age, sex, operative procedure, and ASA score.  相似文献   
60.

Background

It is known that complex regional pain syndrome (CRPS) occurs after arthroscopic rotator cuff repair (ARCR); however, few studies have investigated this complication. Therefore, the purpose of the present study was to evaluate CRPS after ARCR.

Methods

A total of 182 patients who underwent ARCR were enrolled in this study. The average age of patients was 62.8 ± 10.0 years, with an average follow-up period of 21.5 ± 38.1 months. CRPS criteria outlined by the Ministry of Health, Labor, and Welfare study team for CRPS in Japan (MHLWJ) and International Association for the Study of Pain (IASP 2005) were utilized for diagnosis. There are two rating systems for the “clinical purpose” and “research purpose” in both criteria, respectively. Clinical outcomes, including Japanese Orthopedic Association (JOA) and University of California, Los Angeles scores, were evaluated using univariate and multivariate analysis.

Results

CRPS exclusively occurred in the hand of the operated limb, developing within 3 months of surgery. Two or more of the following symptoms were noted in patients with the hand lesion associated with CRPS: edema (93.4%), restricted range of motion (83.4%), hyperalgesia (30.1%), paridrosis (20.4%), and atrophic change (12.2%). Under these conditions, the incidences of CRPS were 24.2% (44/182) when evaluated by the MHLWJ rating system for the “clinical purpose;” 11% (22/182) by the MHLWJ rating system for the “research purpose;” 6% (11/182) by the IASP 2005 for the “clinical purpose;” and 0.5% (1/182) by the IASP 2005 for the “research purpose.” Results of multivariate analysis demonstrated that “Function” in the JOA score was a risk factor for the development of CRPS after ARCR, when evaluated by a system for the “clinical purpose” of the MHLWJ.

Conclusion

Following ARCR, CRPS-induced hand lesions occur more frequently than is generally believed, thereby suggesting that its impact on surgical outcomes should be clarified in the future.  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