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   5326篇
  免费   274篇
  国内免费   78篇
耳鼻咽喉   96篇
儿科学   52篇
妇产科学   51篇
基础医学   906篇
口腔科学   136篇
临床医学   524篇
内科学   1034篇
皮肤病学   114篇
神经病学   459篇
特种医学   353篇
外科学   741篇
综合类   25篇
预防医学   207篇
眼科学   53篇
药学   457篇
  1篇
中国医学   76篇
肿瘤学   393篇
  2023年   44篇
  2022年   168篇
  2021年   242篇
  2020年   109篇
  2019年   122篇
  2018年   152篇
  2017年   124篇
  2016年   197篇
  2015年   352篇
  2014年   358篇
  2013年   395篇
  2012年   571篇
  2011年   541篇
  2010年   279篇
  2009年   244篇
  2008年   328篇
  2007年   286篇
  2006年   233篇
  2005年   161篇
  2004年   111篇
  2003年   96篇
  2002年   84篇
  2001年   82篇
  2000年   67篇
  1999年   47篇
  1998年   44篇
  1997年   25篇
  1996年   36篇
  1995年   22篇
  1994年   25篇
  1993年   20篇
  1992年   15篇
  1991年   4篇
  1990年   6篇
  1989年   5篇
  1988年   15篇
  1987年   7篇
  1986年   8篇
  1985年   10篇
  1984年   5篇
  1983年   8篇
  1982年   3篇
  1981年   2篇
  1980年   3篇
  1979年   3篇
  1977年   8篇
  1976年   4篇
  1975年   3篇
  1963年   1篇
  1961年   1篇
排序方式: 共有5678条查询结果,搜索用时 15 毫秒
81.

Background

Suspension ligamentoplasty using abductor pollicis longus (APL) tendon without bone tunneling, was introduced as one of the techniques for treatment of advanced first carpometacarpal (CMC) arthritis. The purpose of this study was to evaluate the radiologic and clinical results of APL suspension ligamentoplasty.

Methods

The medical records of 19 patients who underwent APL suspension ligamentoplasty for advanced first CMC arthritis between January 2008 and May 2012 were reviewed retrospectively. The study included 13 female and 6 male patients, whose mean age was 62 years (range, 43 to 82 years). For clinical evaluation, we assessed the grip and pinch power, radial and volar abduction angle, thumb adduction (modified Kapandji index), including visual analogue scale (VAS) and Disabilities of the Arm, Shoulder and Hand (DASH) scores. Radiologic evaluation was performed using simple radiographs.

Results

The mean follow-up was 36 months (range, 19 to 73.7 months). Mean power improved from 18.3 to 27 kg for grip power, from 2.8 to 3.5 kg for tip pinch, and from 4.3 to 5.4 kg for power pinch. All patients showed decreased VAS from 7.2 to 1.7. Radial abduction improved from 71° preoperatively to 82° postoperatively. The modified Kapandji index showed improvement from 6 to 7.3, and mean DASH was improved from 41 to 17.8. The height of the space decreased from 10.8 to 7.1 mm. Only one case had a complication involving temporary sensory loss of the first dorsal web space, which resolved spontaneously.

Conclusions

The APL suspension ligamentoplasty for treatment of advanced first CMC arthritis yielded satisfactory functional results.  相似文献   
82.
PURPOSEThe aim of this study was to compare the changes in retentive force of stud attachments for implant overdentures by in vitro 2-year-wear simulation.RESULTSA comparison of the initial retentive force revealed the highest value for Kerator, followed by the O-ring and EZ lock attachments. However, no significant difference was detected between Kerator and O-ring (P>.05). After 2500 insertion and removal cycles, the highest retention loss was recorded for O-ring, and no significant difference between Kerator and EZ lock (P>.05). Also, Kerator showed the highest retentive force, followed by EZ lock and O-ring, after 2500 cycles (P<.05). Based on SEM analysis, the polymeric components in O-ring and Kerator were observed to exhibit surface wear and deformation.CONCLUSIONAfter 2500 insertion and removal cycles, all attachments exhibited significant loss in retention. Mechanism of retention loss can only be partially explained by surface changes.  相似文献   
83.
84.
85.
Intracortical microstimulation (ICMS) is a technique that was developed to derive movement representation of the motor cortex. Although rats are now commonly used in motor mapping studies, the precise characteristics of rat motor map, including symmetry and consistency across animals, and the possibility of repeated stimulation have not yet been established. We performed bilateral hindlimb mapping of motor cortex in six Sprague-Dawley rats using ICMS. ICMS was applied to the left and the right cerebral hemisphere at 0.3 mm intervals vertically and horizontally from the bregma, and any movement of the hindlimbs was noted. The majority (80%±11%) of responses were not restricted to a single joint, which occurred simultaneously at two or three hindlimb joints. The size and shape of hindlimb motor cortex was variable among rats, but existed on the convex side of the cerebral hemisphere in all rats. The results did not show symmetry according to specific joints in each rats. Conclusively, the hindlimb representation in the rat motor cortex was conveniently mapped using ICMS, but the characteristics and inter-individual variability suggest that precise individual mapping is needed to clarify motor distribution in rats.

Graphical Abstract

相似文献   
86.
The aim of this study was to evaluate the incidence of and risk factors for the development of diabetic retinopathy (DR) and progression to proliferative DR (PDR) in Korean patients. Patients diagnosed with type 2 diabetes and followed for more than 5 years at a university-based clinic since 2000 were consecutively enrolled in this retrospective cohort study. Based on the DR classification at the initial and final visits, the incidence and progression of DR was determined and patient characteristics were compared according to DR progression. Hazard ratios of each putative risk factor for DR progression were calculated with a multivariate Cox proportional hazard model. Rate of DR development and progression to PDR were 32.1/1,000 and 26.2/1,000 person-years, respectively. A longer duration of diabetes and higher mean HbA1c level were significant risk factors for the development of DR. Regarding progression to PDR, higher mean HbA1c level, higher standard deviation of HbA1c, and higher urine albumin-to-creatinine ratio were significant risk factors. The rates of development of DR and progression to PDR in Koreans with type 2 diabetes are lower than those reported over the last decade. An inadequate blood glycemic control is the common risk factor for development and progression of DR.

Graphical Abstract

相似文献   
87.
A double toxin-double lesion strategy is well-known to generate a rat model of striatonigral degeneration (SND) such as multiple system atrophy-parkinsonian type. However, with this model it is difficult to distinguish SND from Parkinson''s disease (PD). In this study, we propose a new rat model of SND, which is generated by simultaneous injection of 6-hydroxydopamine into the medial forebrain bundle and quinolinic acid into the striatum. Stepping tests performed 30 min after intraperitoneal L-dopa administration at 6 weeks post-surgery revealed an L-dopa response in the PD group but not the SND group. Apomorphine-induced rotation tests revealed no rotational bias in the SND group, which persisted for 2 months, but contralateral rotations in the PD group. MicroPET scans revealed glucose hypometabolism and dopamine transporter impairment on the lesioned striatum in the SND group. Tyrosine hydroxylase immunostaining in the SND group revealed that 74.7% of nigral cells on the lesioned side were lost after lesion surgery. These results suggest that the proposed simultaneous double toxin-double lesion method successfully created a rat model of SND that had behavioral outcomes, multitracer microPET evaluation, and histological aspects consistent with SND pathology. This model will be useful for future study of SND.  相似文献   
88.
89.
90.
Squamoid eccrine ductal carcinoma (SEDC) is an exceedingly rare tumor that shows both squamous differentiation and adnexal ductal differentiation. As our review of the literature revealed, only a total of 7 cases were reported to date. We report an additional case of SEDC occurring on the scalp of a 53-year-old man. Despite complete excision by conventional technique with clear margin, the lesion recurred within a 3-month period, with regional lymph node metastasis. The tumor was completely removed, and the large scalp defect was reconstructed by using scalp rotation flap. We present a case of recurrent SEDC on the scalp, and we surgically resected this tumor. In addition, the large scalp defect was reconstructed successfully with scalp flap, and no recurrence has been observed in the patient's postoperative follow-ups.  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