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   881篇
  免费   31篇
  国内免费   10篇
耳鼻咽喉   27篇
儿科学   27篇
妇产科学   24篇
基础医学   108篇
口腔科学   6篇
临床医学   72篇
内科学   199篇
皮肤病学   20篇
神经病学   105篇
特种医学   21篇
外科学   106篇
综合类   3篇
预防医学   38篇
眼科学   28篇
药学   67篇
肿瘤学   71篇
  2023年   7篇
  2022年   12篇
  2021年   38篇
  2020年   28篇
  2019年   29篇
  2018年   21篇
  2017年   16篇
  2016年   13篇
  2015年   17篇
  2014年   17篇
  2013年   36篇
  2012年   64篇
  2011年   54篇
  2010年   15篇
  2009年   24篇
  2008年   62篇
  2007年   40篇
  2006年   46篇
  2005年   31篇
  2004年   46篇
  2003年   41篇
  2002年   28篇
  2001年   22篇
  2000年   24篇
  1999年   19篇
  1998年   8篇
  1997年   6篇
  1996年   7篇
  1995年   3篇
  1993年   7篇
  1992年   26篇
  1991年   11篇
  1990年   9篇
  1989年   9篇
  1988年   8篇
  1987年   13篇
  1986年   5篇
  1985年   6篇
  1984年   8篇
  1983年   4篇
  1980年   2篇
  1978年   2篇
  1977年   2篇
  1974年   2篇
  1970年   3篇
  1969年   2篇
  1968年   3篇
  1967年   5篇
  1966年   8篇
  1965年   3篇
排序方式: 共有922条查询结果,搜索用时 15 毫秒
1.

Background

Many patients undergoing below knee amputations (BKA) return for subsequent unplanned operations, hospital readmission, or postoperative complications. This unplanned medical management negatively impacts both patient outcomes and our healthcare system. This study primarily investigates the risk factors for unplanned reoperation following BKA.

Methods

Below knee amputations from the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database from the years 2012–2014 were identified by CPT code 27880 for amputation through the tibia and fibula. Our query identified 4631 BKA cases, including 30 day complications. Multivariate logistic regression modeling was performed on several patient demographic and disease factors to assess for independent predictors of unplanned reoperation. Secondary outcomes of unplanned and related readmissions (related to the procedure), major complications, minor complications, and mortality were also included in the analysis.

Results

Of 4631 BKAs identified, 9.63% (446/4631) underwent unplanned reoperations and 8.75% (405/4631) had unplanned and related readmissions. Major complications were experienced by 12.8% (593/4631) and minor complications by 8.7% (401/4631). Thirty day mortality rate was 5.14% (238/4631). The most common procedures for unplanned operations were thigh amputations (128/446, 28.7%), debridement/secondary closure (114/446, 25.6%), and revision leg amputations (46/446, 10.32%). Factors associated with an increased risk of unplanned reoperation included patients transferred from another facility (Adjusted Odds Ratio [AOR]?=?1.28; p?=?.04), recent smokers (AOR?=?1.34; p?=?.02), bleeding disorder (AOR?=?1.30; p?=?.02), and preoperative ventilator use (AOR?=?2.38; p?=?.01).

Conclusion

Patients that were ongoing/recent smokers, had diagnosed bleeding disorders, required preoperative ventilator use, or were transferred in from another facility were associated with the highest risks of reoperation following BKA. This patient population experiences high rates of reoperation, readmission, complication, and mortality.  相似文献   
2.
Background Oxidative stress and increased inflammation have been reported to be increased in subjects with diabetes and to be involved in the pathogenesis of cardiovascular complications after myocardial infarction (MI). It is well recognized that red wine has antioxidant and anti‐inflammatory activities. We examined the effects of moderate red wine intake on echocardiographic parameters of functional cardiac outcome in addition to inflammatory cytokines and nitrotyrosine (oxidative stress marker), in subjects with diabetes after a first uncomplicated MI. Methods One hundred and fifteen subjects with diabetes who had sustained a first non‐fatal MI were randomized to receive a moderate daily amount of red wine (intervention group) or not (control group). Echocardiographic parameters of ventricular dys‐synchrony, circulating levels of nitrotyrosine, tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6), interleukin‐18 (IL‐18) and C‐reactive protein (CRP) were investigated at baseline and 12 months after randomization. Results After 1 year of diet intervention, concentrations of nitrotyrosine (P < 0.01), CRP (P < 0.01), TNF‐α (P < 0.01), IL‐6 (P < 0.01) and IL‐18 (P < 0.01) were increased in the control group compared with the intervention group. In addition, myocardial performance index (P < 0.02) was higher, and transmitral Doppler flow (P < 0.05), pulmonary venous flow analysis (P < 0.02) and ejection fraction (P < 0.05) were lower in the control group, indicating ventricular dys‐synchrony. The concentrations of nitrotyrosine, CRP, TNF‐α and IL‐6 were related to echocardiographic parameters of ventricular dys‐synchrony. Conclusions In subjects with diabetes, red wine consumption, taken with meals, significantly reduces oxidative stress and pro‐inflammatory cytokines as well as improving cardiac function after MI. Moderate red wine intake with meals may have a beneficial effect in the prevention of cardiovascular complications after MI in subjects with diabetes.  相似文献   
3.
Test properties of the Millon Clinical Multiaxial Inventory (MCMI) were examined in a sample of 419 sex offenders and controls in three different settings. The offender group included sexual aggressives, pedophiles, incest perpetrators and miscellaneous cases. Nineteen of the 20 scales of the MCMI had alpha reliability over 0.60 and for 13 scales it was over 0.80. The scales showed satisfactory discriminant validity from age but 9 scales showed a moderate influence of intelligence scores and education. Criminal history did not influence scale results. The scales unfortunately did show significant correlations with MMPI validity scales. Although the scales were not susceptible to naive lying, they were influenced by social desirability especially. Four factors were extracted in principal axes factor analysis that accounted for 91.2% of the total variance. The first factor explained 58.2% of the variance and was labeled general psychopathology. The other three factors suggested psychotic tendencies, extraversion and the bipolar dependency-antisocial tendencies. When the groups were compared, almost all scales significantly differentiated them. When the MMPI F-K Scale was forced to enter a stepwise discriminant analysis first, five scales still were significant; Narcissistic, Schizoid-Asocial, Alcohol Abuse, Paranoid, & Dependent-Submissive scales. The MCMI taps important dimensions in sex offenders but suffers from validity problems.  相似文献   
4.
Meningiomas have been reported following radiation of the head, usually with a long latent interval between exposure and the diagnosis of the new tumor. We report a benign meningioma resected approximately 3 1/2 years after radiation therapy for a glioma, which represents an unusually short latent interval between radiation and new tumor growth.  相似文献   
5.
We recorded the electro-oculogram from 27 normal subjects by means of green and near-ultraviolet (UVA) stimulation. After a 40-minute dark-adaptation period, baseline responses were recorded. In response to the green stimulus, the electro-oculogram increased from this level by an average (± standard error of the mean) of 49.5% ±4.0%. Although the predicted scotopic effectiveness of the ultraviolet stimulus was more than 3 log units below that of the green stimulus, the near-ultraviolet-induced electro-oculogram increased to an average of 21.9% ±3.0% above baseline. This response cannot be due to lens fluorescence to the near-ultraviolet stimulus, since two aphakic subjects had electro-oculographic responses of 32% and 76% above baseline to near-ultraviolet stimuli. Neither the green nor the ultraviolet electro-oculogram changed significantly with age. These large responses to near-ultraviolet stimulation demonstrate the need for standardizing light sources for electro-oculographic testing because the degree of near-ultraviolet irradiance varies considerably according to their design characteristics.  相似文献   
6.
The authors report a case of extrinsic stenosis of the sigmoid colon due to inflammation of the uterus and adjoining parts. Attention is drawn to the possibility that the radiological images of this condition may be similar to neoplastic diseases.  相似文献   
7.
To analyse the effect of concomitant cognitive or motor task performance on balance control in Parkinson's disease (PD), we performed a posturographic study in 24 PD patients and in 20 sex- and age-matched control subjects. Postural sway was measured with eyes open (EO) and eyes closed (EC) during quiet stance and during performance of calculation or motor sequence of thumb opposition to the other fingers. No difference of centre of foot pressure (COP) parameters was observed during quiet standing (either EO or EC) between patients and controls, but visual deprivation induced in both groups a worsening of postural stability. COP area was significantly increased in PD patients during dual task performance, whereas no difference of COP path and x-y axes was observed. The effects induced by the performance of cognitive or motor task were significantly more evident in PD patients with clinical evidence of postural instability (presence of prior falls in the history). This study demonstrates that dual task interference on postural control can be observed in PD patients during performance of cognitive as well as motor tasks. The balance deterioration during dual task performance was significantly enhanced in patients with history of prior falls. These findings have some implications for the strategies to be used in reducing the risk of fall in PD.  相似文献   
8.
Transglutaminase (TGase) activity was reduced in intact mitogen-stimulated human peripheral blood lymphocytes (PBL) when compared to intact resting PBL. Moreover, a treatment of the same quiescent immunocompetent cells with purified liver TGase and Ca2+ completely suppressed the mitogen-induced blast transformation. A decrease in TGase activity in neoplastically transformed seminal vesicle epithelial cells with respect to their normal parent counterpart was also observed. Our data support the notion of a possible implication of TGase in cell proliferation and transformation.  相似文献   
9.
10.
The effects of sodium arsenite at a sub-MIC concentration (25 mg/l) upon different bacterial functions were studied. This compound reduced the killing activity of nalidixic acid, amikacin, and meropenem. It also promoted the loss of F'lac from bacterial hosts and increased the number of recombinants in conjugation and transduction experiments. Transposition of Tn9 was also enhanced by the salt. In addition, sodium arsenite abolished the lethal effect of temperature on thermosusceptible DNA synthesis mutants in a similar manner to that seen in an anaerobic environment. Finally at a low dose, it induced the SOS response, and the related production of recA-dependent enzymes was reduced as the sodium arsenite concentration increased. It has been suggested that arsenite primarily affects the uvrA gene product, influencing the other bacterial functions studied. The energetic depletion caused by this compound appears to play a role in the activity of autolytic enzymes.  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