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   1041篇
  免费   39篇
  国内免费   6篇
耳鼻咽喉   11篇
儿科学   28篇
妇产科学   41篇
基础医学   71篇
口腔科学   79篇
临床医学   59篇
内科学   171篇
皮肤病学   11篇
神经病学   111篇
特种医学   101篇
外科学   284篇
综合类   9篇
一般理论   1篇
预防医学   12篇
眼科学   23篇
药学   54篇
肿瘤学   20篇
  2023年   9篇
  2022年   19篇
  2021年   20篇
  2020年   13篇
  2019年   23篇
  2018年   27篇
  2017年   31篇
  2016年   41篇
  2015年   30篇
  2014年   48篇
  2013年   65篇
  2012年   73篇
  2011年   76篇
  2010年   42篇
  2009年   41篇
  2008年   63篇
  2007年   78篇
  2006年   73篇
  2005年   72篇
  2004年   75篇
  2003年   58篇
  2002年   43篇
  2001年   11篇
  2000年   7篇
  1999年   4篇
  1998年   6篇
  1997年   2篇
  1996年   10篇
  1995年   3篇
  1994年   2篇
  1993年   1篇
  1992年   8篇
  1990年   2篇
  1988年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1974年   2篇
  1965年   1篇
排序方式: 共有1086条查询结果,搜索用时 0 毫秒
21.
22.
23.
Toll-like receptors (TLRs) belonging to pattern recognition receptors are involved in maintaining testicular and epididymal immune homeostasis. The purpose of the current study was to investigate TLR4 expression in rat testis and epididymis throughout postnatal development. Weak staining was detected in peritubular myoid cells and immature Sertoli cells while no staining was observed in gonocytes during prepubertal period. However, TLR4 expression began to appear in spermatocytes in pubertal period and gradually increased in spermatids. An intense staining was observed in steps 5–19 spermatids in post pubertal and mature periods. Similarly, TLR4 expression in the testes steadily increased from pubertal period to mature period. Puberty also caused a significant increase in TLR4 expression in epididymis. TLR4 expression in cauda epididymis was lower as compared to those of other epididymal segments. The majority of epididymal epithelial cells exhibited apical TLR4 expression, whereas basal cells showed intense intracytoplasmic immunoreaction. We detected an intense staining in epididymal smooth muscle cells. The expression levels of TLR4 showed dynamic changes in both spermatogenic cells, and entire testicular and epididymal tissues during postnatal development. These results suggest that TLR4 expression contributes not only to inflammation but also to the development of spermatogenic cells.  相似文献   
24.
Aortic stiffness increases in patients with erectile dysfunction (ED) but it is not known whether aortic stiffness affects the degree of ED. In the present study, we aimed to determine whether there is any relationship between aortic stiffness and the severity of ED. Patients with ED were divided into 3 groups according to the International Index of Erectile Function (IIEF) scores. Mild ED was named as group 1, moderate ED as group 2 and severe ED as group 3. The values of fasting blood glucose (FBG), serum lipid values, total testosterone (T. tes), and free testosterone (F tes) were recorded. Aortic stiffness was determined by pulse wave velocity (PWV) and augmentation index (AIX) measurements. The mean or median values of the laboratory parameters among the groups were similar (> .05). No statistical difference was found between the groups in terms of AIX value (p = .386). Mean PWV values were calculated as 7.26, 8.30 and 8.78 in group 1, group 2 and group 3 respectively. PWV values were significantly different between groups (< .0001). PWV values were found to be increased with increasing severity of erectile dysfunction.  相似文献   
25.

Purpose

The aim of this study was to demonstrate regeneration of intervertebral discs undergoing laser therapy with sagittal relaxation time (T2) mapping after a long-term follow-up.

Materials and methods

Fourteen patients (9 men, 5 women; age range 20–57 years; mean age 36.5 years) treated with percutaneous 908-nm wave-length diode laser nucleoplasty for lumbar disc prolapsus at our clinic between January 2006 and June 2009 were studied. For the application of laser nucleoplasty in the past, patients who did not have central canal stenosis and/or lateral stenosis, sequestered disc fragment, operation scars and bleeding disorders were selected. The intervertebral disc levels undergoing laser therapy were L3–L4 (n = 2) or L4–L5 (n = 12). Patients were called for follow-up visits after a maximum 6-years (n = 2) or a minimum 3 years (n = 3) with a mean of 4.4 years. The patients’ clinical status for leg pain was evaluated according to the visual analog scale (VAS) and subsequently, a lumbar magnetic resonance imaging was performed. Sagittal T2 mapping was performed for the intervertebral discs undergoing laser nucleoplasty. We analyzed the relationship between T2 in the regions of interest (ROIs), which is known to correlate with changes in the composition of intervertebral discs, and the degree of degeneration determined using the Pfirrmann grading system and VAS of patients.

Results

On the basis of the evaluation of the results of intervertebral discs in all patients, there was a significant increase in T2 in the anterior NP (ROI 2, +10.3 ms; p < 0.05). A significant increase was noted in T2 in the middle NP (ROI 3, +24.6 ms; p < 0.001). The most significant increase was recorded for the posterior NP (ROI 4, +28.6 ms; p < 0.001). No significant decrease was found in T2 in the anterior and posterior AF (ROI 1, ?1.5 ms; p = 0.925; ROI 5, ?0.1 ms; p = 0.683). According to the Pfirrmann grading system, disc degeneration grades before laser therapy were recorded as grade III (n = 6) and grade IV (n = 8) whereas disc degeneration grades after laser therapy were found to be grade I (n = 6) and II (n = 8). A significant decrease was noted in Pfirrmann grades of disc degeneration after laser therapy (p < 0.0005).

Conclusions

In this study, there was a prolongation of T2 indicating regeneration in the nucleus pulposus after laser therapy and these results were found to be consistent with VAS measurements after a long-term follow-up. This study, which demonstrates the quantitative efficacy of laser therapy, indicates that MRG can be more effectively used in the future.  相似文献   
26.
Metabolic myopathies due to disorders of lipid metabolism are a heterogeneous group of diseases. Newborns may present with hypotonia and convulsions, while progressive proximal muscle weakness or recurrent episodes of muscle weakness accompanied by rhabdomyolysis/myoglobinuria may be seen in older ages. There is little knowledge on detection of disorders of lipid metabolism by acylcarnitine profile (ACP) analysis by tandem mass spectrometry outside the neonatal period particularly in cases with recurrent rhabdomyolysis first presenting in adolescence and adulthood. Two adolescent female cases presented with episodes of rhabdomyolysis and muscle weakness. A 13-year-old patient had five episodes of rhabdomyolysis triggered by infections. Tandem mass spectrometry was normal. A 16-year-old female patient was hospitalized eight times due to recurrent rhabdomyolysis. Increased levels of C14:2, C14:1, and C14 were determined in tandem mass spectrometry. Final diagnoses were carnitine palmitoyltransferase II (CPT II) deficiency and very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency. Increased serum levels of long-chain acylcarnitine can guide to the diagnosis of lipid metabolism disorders. Serum ACP should be performed before enzyme assay and genetic studies.  相似文献   
27.
We herein report successful cryoablation of paroxysmal atrial fibrillation via right jugular vein in a patient with interrupted inferior vena cava. We preferred cryoablation instead of radiofrequency ablation in the treatment of our patient. For stronger support in aiming the Brockenbrough needle toward the septum, we manuallly curved the needle with a 120° angle about 6 cm proximal to the tip. After successful transseptal puncture, we performed balloon dilatation in the septal puncture zone to facilitate passage. Cryoablation has theoretical advantage, particularly in challenging anatomies, in which it eliminates the need for point‐by‐point ablation around the pulmonary vein.  相似文献   
28.
Metabolic Brain Disease - Cerebellar ataxia (CA) is a form of ataxia that adversely affects the cerebellum. Cell replacement therapy (CRT) has been considered as a potential treatment for...  相似文献   
29.
30.
Paketci  Cem  Edem  Pinar  Okumus  Canan  Sarioglu  Fatma Ceren  Bayram  Erhan  Hiz  Semra  Yis  Uluç 《Journal of neurovirology》2020,26(2):270-272
Journal of NeuroVirology - Acute cerebellitis is one of the most common cerebellar disorders and occurs due to para-infectious, post-infectious, or post-vaccination cerebellar inflammation. Herpes...  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