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   1646篇
  免费   105篇
  国内免费   7篇
耳鼻咽喉   45篇
儿科学   58篇
妇产科学   46篇
基础医学   88篇
口腔科学   182篇
临床医学   96篇
内科学   340篇
皮肤病学   19篇
神经病学   119篇
特种医学   62篇
外科学   501篇
综合类   12篇
预防医学   22篇
眼科学   48篇
药学   54篇
中国医学   1篇
肿瘤学   65篇
  2024年   3篇
  2023年   26篇
  2022年   48篇
  2021年   58篇
  2020年   50篇
  2019年   50篇
  2018年   70篇
  2017年   48篇
  2016年   81篇
  2015年   92篇
  2014年   90篇
  2013年   80篇
  2012年   132篇
  2011年   143篇
  2010年   83篇
  2009年   63篇
  2008年   109篇
  2007年   114篇
  2006年   102篇
  2005年   88篇
  2004年   65篇
  2003年   56篇
  2002年   33篇
  2001年   17篇
  2000年   11篇
  1999年   15篇
  1998年   4篇
  1997年   2篇
  1996年   3篇
  1995年   2篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   4篇
  1990年   3篇
  1988年   4篇
  1987年   1篇
  1985年   1篇
  1983年   1篇
排序方式: 共有1758条查询结果,搜索用时 15 毫秒
71.
IntroductionThe diagnostic approach to patients with isolated asymptomatic cervical lymphadenopathy varies between excisional biopsy and follow-up. When the anamnesis, physical examination, laboratory and imaging findings are not sufficient to identify the etiology, an excisional biopsy is performed for the differential diagnosis between early-stage lymphoma and infectious or reactive causes. If the excisional biopsy, which may have some complications, is not performed, it may delay the diagnosis of lymphoma. This diagnostic challenge could be avoided by predictive markers.ObjectivesThis study was planned to determine the predictive value of neutrophil/lymphocyte ratio in the diagnosis of Hodgkin and non-Hodgkin limphoma in patients with asymptomatic, isolated cervical limphadenopathy and underwent excisional biopsy.MethodsA total of 90 patients between the years 2016 ? 2019 admitted to our clinics due to asymptomatic isolated cervical lymphadenopathy, present in at least 4 weeks with lympho nodes in pathological dimensions persisting in the cervical region, were included to our study. An excisional lympho node biopsy was performed in all 90 patients.ResultsOf the 90 patients who underwent excisional biopsy; 34 were diagnosed as reactive lymphadenopathy 30 were non-Hodgkin linphoma, and 26 were Hodgkin linphoma. A total of 56 (62.2%) patients were diagnosed as lymphoma, either Hodgkin or non-Hodgkin, while 34 patients (38.8%) were diagnosed as reactive lymphadenopathy. The median age, total whiteblood count, neutrophil count of the lymphoma groups were significantly higher than reactive lymphadenopathy group, whereas the lymphocyte count was significantly lower in the lymphoma patients. The median neutrophil/ lymphocyte ratio was 1.7 in the reactive lymphadenopathy group, 3.5 in the non-Hodgkin limphoma group, and 3.0 in the Hodgkin limphoma group (p <  0.001).ConclusionAccording to the results of our study, neutrophil/lymphocyte ratio was significantly higher in patients who were admitted with isolated asymptomatic lymphadenopathy and were diagnosed with lymphoma, and who were diagnosed with early-stage Hodgkin and non- Hodgkin lymphoma compared to those who were found to have reactive lymphadenopathy. Neutrophil/lymphocyte ratio, which is a low-cost, fast and easy-to-access test, has a predictive value in the diagnosis of lymphoma in patients with asymptomatic lymphadenopathy.  相似文献   
72.
73.
Complex sacral midline defects following spinal surgery have been traditionally closed with either muscle or musculocutaneous flaps. We present a case with a complicated sacral wound extending to the medulla spinalis after a lipomeningomyelocele excision in an ambulating adult. Wound was repaired with a lumbar perforator-based rotation flap. This well-vascularized flap is relatively easy to harvest, and results in minimal donor site morbidity, provides adequate dimensions, and permits primary closure of donor defect. In addition, the flap allows for anatomic muscle approximation without sacrificing the muscle functions, and provides reliable soft tissue coverage. Level of Evidence: Level V, therapeutic study.  相似文献   
74.

Introduction and hypothesis

Little information is available on the effects of concomitant vaginal prolapse repair on the outcomes of the transobturator tape (TOT) procedure. The purpose of this study is to assess the results and complications of TOT when combined with vaginal prolapse repair with a long-term follow-up.

Methods

We conducted a retrospective cohort study of 232 female patients who underwent the TOT procedure at two institutions. There were two groups: group 1 consisted of patients who had undergone TOT alone and group 2 consisted of patients who had undergone concomitant vaginal prolapse repair. The outcomes were analyzed considering four postoperative parameters: objective cure, subjective cure, resolution of urgency urinary incontinence (UUI), and patient satisfaction. The mean follow-up was 66.3 months (range 60–85).

Results

A total of 117 patients in group 1 and 104 patients in group 2 were documented in this study. The subjective and objective cure rates were 87.17 %, 64.95 % in group 1 and 89.42 %, 68.26 % in group 2. Patient satisfaction rates (visual analog scale [VAS] score ≥80) were 71.79 and 83.65 % in groups 1 and 2 respectively (p?=?0.035). Complications were reported according to the Clavien–Dindo classification with grade I 7.7 %, grade II 69.2 %, grade IIIa 7.7 %, and grade IIIb 15.4 %, and grade I 9.5 %, grade II 47.6 %, grade IIIa 42.8 %, and grade IIIb 0 % in groups 1 and 2 respectively.

Conclusions

Concomitant vaginal prolapse repair with TOT does not have any negative effects on continence outcomes; on the contrary, it increases patient satisfaction.  相似文献   
75.
76.

Objective

The clinical suitability of low-shrinkage resin composites for class V cavities has not been investigated in vivo. The purpose of this double-blind randomized clinical trial was to compare the clinical performances of low-shrinkage resin composite Filtek silorane and nanoceramic resin composite Ceram X mono in non-carious cervical lesions (NCCLs) over 36 months.

Materials and methods

Two calibrated operators restored 144 NCCLs in 24 patients by using Filtek silorane with silorane system adhesive (FS/SSA) and Ceram X mono with Clearfil SE (CXM/CSE) or XP bond (CXM/XPB). Then, two blinded, calibrated evaluators assessed the restorations at the baseline and 6, 12, 24, and 36 months thereafter by using the modified US Public Health Service criteria. Data were analyzed with the Freidman and Wilcoxon signed-rank tests at a significance level of 5 % (P?<?0.05).

Results

No restoration was associated with postoperative sensitivity or secondary caries. Further, no group showed significant changes until 12 months. The retention rates of the FS/SSA (97.5 %), CXM/CSE (97.5 %), and CXM/XPB (92.31 %) restorations did not differ significantly (P?>?0.05). Six (4 CXM/XPB, 1 FS/SSA, and 1 CXM/CSE) of the 121 restorations evaluated at 36 months were completely lost. However, no significant intergroup differences were observed in the other evaluation criteria.

Conclusion

The 3-year clinical performances of the restorative materials in NCCLs were not significantly different.

Clinical relevance

Filtek silorane is suitable for restoring NCCLs.  相似文献   
77.
78.
Background/aimCertain constituents in migraine food triggers and non-steroidal anti-inflammatory drugs (NSAIDs) inhibit sulfotransferases (SULTs) that detoxify drugs/chemicals and play role in the metabolism of neurotransmitters. We aimed to dissect SULT1A1 modulation of CSD susceptibility and behavior in an in vivo experimental model using hesperidin, a SULT1A1 inhibitor found in citrus fruits (known migraine triggers) and mefenamic acid (SULT1A1 inhibitor), an NSAID to simulate medication overuse.MethodsHesperidin was used as SULT1A1 inhibitor found in citrus fruits, known migraine triggers and mefenamic acid (NSAID), another SULT1A1 inhibitor, was used to induce MO in rats. The groups were; 1) Hesperidin (ip) or its vehicle-DMSO (ip) 2) Chronic (4 weeks) mefenamic acid (ip) or its vehicle (ip) 3) Chronic mefenamic acid+hesperidin (ip) or DMSO (ip). CSD susceptibility was evaluated and behavioral testing was performed. SULT1A1 enzyme activity was measured in brain samples.ResultsSingle-dose of hesperidin neither changed CSD susceptibility nor resulted in any behavioral change. Chronic mefenamic acid exposure resulted in increased CSD susceptibility, mechanical-thermal hypersensitivity, increased head shake, grooming and freezing and decreased locomotion. Single dose hesperidin administration after chronic mefenamic acid exposure resulted in increased CSD susceptibility and mechanical-thermal hypersensitivity, increased freezing and decreased locomotion. SULT1A1 enzyme activity was lower in mefenamic acid and mefenamic acid+hesperidin groups compared to their vehicles.ConclusionMefenamic acid and hesperidin have synergistic effect in modulating CSD susceptibility and pain behavior. Sulfotransferase inhibition may be the common mechanism by which food triggers and NSAIDs modulate migraine susceptibility. Further investigations regarding human provocation studies using hesperidin in migraine patients with medication overuse are needed.  相似文献   
79.
Open in a separate window OBJECTIVESMost strokes associated with atrial fibrillation (AF) result from left atrial appendage thrombi. Oral anticoagulation can reduce stroke risk but is limited by complication risk and non-compliance. Left atrial appendage exclusion (LAAE) is a new surgical option to reduce stroke risk in AF. The study objective was to evaluate the safety and feasibility of standalone thoracoscopic LAAE in high stroke risk AF patients.METHODSThis was a retrospective, multicentre study of high stroke risk AF patients who had oral anticoagulation contraindications and were not candidates for ablation nor other cardiac surgery. Standalone thoracoscopic LAAE was performed using 3 unilateral ports access and epicardial clip. Periprocedural adverse events, long-term observational clinical outcomes and stroke rate were evaluated.RESULTSProcedural success was 99.4% (174/175 patients). Pleural effusion occurred in 4 (2.3%) patients; other periprocedural complications were <1% each. One perioperative haemorrhagic stroke occurred (0.6%). No phrenic nerve palsy or cardiac tamponade occurred. Predicted annual ischaemic stroke rate of 4.8/100 patient-years (based on median CHA2DS2-VASc score of 4.0) was significantly higher than stroke risk observed in follow-up after LAAE. No ischaemic strokes occurred (median follow-up: 12.5 months), resulting in observed rate of 0 (95% CI 0–2.0)/100 patient-years (P < 0.001 versus predicted). Six all-cause (non-device-related) deaths occurred during follow-up.CONCLUSIONSStudy proved that a new surgical option, standalone thoracoscopic LAAE, is feasible and safe. With this method, long-term stroke rate may be reduced compared to predicted for high-risk AF population.  相似文献   
80.
Traumatic brain injury (TBI) continues to be a significant public healthcare concern. Neuroinflammation that occurs in the secondary phase of TBI leads to cognitive and physical dysfunction. A number of therapeutic modalities have been evaluated in an attempt to find a suitable treatment. The only drug approved for the treatment of idiopathic pulmonary fibrosis, pirfenidone, has been evaluated for its antifibrotic, anti-inflammatory, and anti-oxidant properties for various disorders, but this is the first study to examine its effects in an experimental TBI model. Twenty-four Wistar rats were randomly divided into three groups: control, trauma, and pirfenidone. The two latter groups underwent experimental diffuse cortical injury mimicking TBI. Neurological assessment was performed using the Garcia test, histological analysis was performed to examine neuroprotective and anti-inflammatory effects, and biochemical analyses of neuron-specific enolase (NSE), S-100B, caspase-3, and thiobarbituric acid reactive substances were performed. The pirfenidone group had a better Garcia test score (P=0.001), an increased anti-inflammatory effect (P<0.001), and an enhanced neuroprotective effect (P=0.007) along with decreased NSE, S100B, and TBARS levels compared to the trauma group. However, pirfenidone did not show a beneficial effect on caspase-3 levels. Pirfenidone may help decrease mortality and morbidity rates after TBI through its anti-inflammatory and antioxidant effects.  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