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   32052篇
  免费   2341篇
  国内免费   2018篇
耳鼻咽喉   1488篇
儿科学   222篇
妇产科学   106篇
基础医学   4629篇
口腔科学   909篇
临床医学   2661篇
内科学   1343篇
皮肤病学   173篇
神经病学   8230篇
特种医学   958篇
外国民族医学   2篇
外科学   5884篇
综合类   4180篇
预防医学   414篇
眼科学   2405篇
药学   1528篇
  15篇
中国医学   838篇
肿瘤学   426篇
  2024年   26篇
  2023年   416篇
  2022年   600篇
  2021年   998篇
  2020年   1120篇
  2019年   969篇
  2018年   930篇
  2017年   1207篇
  2016年   1210篇
  2015年   1175篇
  2014年   1915篇
  2013年   1919篇
  2012年   1505篇
  2011年   1682篇
  2010年   1570篇
  2009年   1393篇
  2008年   1585篇
  2007年   1560篇
  2006年   1448篇
  2005年   1226篇
  2004年   1154篇
  2003年   1084篇
  2002年   964篇
  2001年   856篇
  2000年   706篇
  1999年   652篇
  1998年   572篇
  1997年   523篇
  1996年   393篇
  1995年   452篇
  1994年   404篇
  1993年   372篇
  1992年   401篇
  1991年   337篇
  1990年   345篇
  1989年   277篇
  1988年   230篇
  1987年   241篇
  1986年   241篇
  1985年   322篇
  1984年   273篇
  1983年   185篇
  1982年   211篇
  1981年   184篇
  1980年   166篇
  1979年   112篇
  1978年   77篇
  1977年   71篇
  1976年   55篇
  1975年   31篇
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
21.

Objective

To assay peripheral inter-ictal cytokine serum levels and possible relations with non-invasive vagus nerve stimulation (nVNS) responsiveness in migraineurs.

Methods

This double-blinded, sham-controlled study enrolled 48 subjects and measured headache severity, frequency [headache days/month, number of total and mild/moderate/severe classified attacks/month], functional state [sleep, mood, body weight, migraine-associated disability] and serum levels of inflammatory markers [inter-ictal] using enzyme-linked immunoassays at baseline and after 2 months of adjunctive nVNS compared to sham stimulation and suitably matched controls.

Results

No significant differences were observed at baseline and after 2 months for headache severity, total attacks/month, headache days/month and functional outcome [sleep, mood, disability] between verum and sham nVNS. However, the number of severe attacks/month significantly decreased in the verum nVNS group and circulating pro-inflammatory IL-1β was elevated significantly in the sham group compared to nVNS. Levels of anti-inflammatory IL-10 were significantly higher at baseline in both groups compared to healthy controls, but not at 2 months follow-up [p?<?0.05]. Concentrations of high-mobility group box-1 (HMGB-1), IL-6, tumor-necrosis factor-α (TNF-α), leptin, adiponectin, ghrelin remained unchanged [p?>?0.05]. No severe device-/stimulation-related adverse events occurred.

Conclusion

2 months of adjunctive cervical nVNS significantly declined the number of severe attacks/month. Pro-inflammatory IL-1β plasma levels [inter-ictal] were higher in sham-treated migraine patients compared to verum nVNS. However, pro- [IL-6, HMGB-1, TNF-α, leptin] and anti-inflammatory [IL-10, adiponectin, ghrelin] mediators did not differ statistically. Profiling of neuroinflammatory circuits in migraine to predict nVNS responsiveness remains an experimental approach, which may be biased by pre-analytic variables warranting large-scale biobank-based systematic investigations [omics].  相似文献   
22.
The Lapidus bunionectomy is performed to treat hallux valgus. Recurrence of the deformity remains a concern. A transverse intermetatarsal screw spanning the base of the first metatarsal to the base of the second can increase stability. The neurovascular bundle is located within the proximity of this screw. In this study, we assessed the structures at risks with the use of this technique. In 10 specimens, a guide wire was placed, and a 4.0-mm cannulated screw was inserted. The neurovascular bundle was dissected and inspected for direct trauma to the neurovascular bundle, and the proximity of the screw was measured using a digital caliper. Ten cadaveric specimens were used. The dorsalis pedis artery and deep peroneal nerve were free from injury in 9 of 10 specimens. In those 9 specimens, the neurovascular bundle was located dorsal in relation to the screw. The mean distance of the screw to the neurovascular bundle was 7.1 ± 3.3 mm. The mean distance from the screw to the first tarsometatarsal joint (TMTJ) was 14.7 ± 4.3 mm. The mean distance from the screw as it entered the second metatarsal to the second TMTJ was 18.0 ± 7.2 mm. In 1 specimen, the screw was found to be traversing through the neurovascular bundle. The distance from the screw to the first TMTJ was 15.0 mm. The distance of the screw from where it entered the second metatarsal to the second TMTJ was 24.0 mm. Although the intermetatarsal screw avoided the neurovascular cases in most instances, there is some anatomic risk to the neurovascular bundle. Further study is warranted to evaluate clinical results using the intermetatarsal screw for the modified Lapidus procedure.  相似文献   
23.
Introduction: Tumor biology, as well as completeness of surgical resection, are two important prognostic factors when treating retroperitoneal sarcoma (RPS). A frontline extended surgical approach is associated with improved local control and possibly improved survival. However, this approach has to be tailored to each histological subtype, as the patterns of growth and recurrence risks vary significantly among them.

Areas covered: We provide a review of the literature in RPS, describing the behavior of each of the five main histologic subtypes: well-differentiated liposarcoma (WDLPS), dedifferentiated liposarcoma (DDLPS), leiomyosarcoma (LMS), solitary fibrous tumor (SFT) and malignant peripheral nerve sheath tumor (MPNST). The prognostic factors relevant to oncologic outcomes of RPS, the role of margins and the importance of local control are discussed. Finally, a histologic specific surgical approach to RPS is provided in detail.

Expert opinion: While tumor-related factors are paramount, the only intervenable predictive factor is extent and quality of surgery. The extended surgical approach has been advocated for previously and again we describe it in more detail, tailored specifically to the tumor subtype. The aim of this approach is to maximize the possibility of achieving a complete resection through a standardized approach based on histologic behavior and site of origin.  相似文献   

24.

Background

Previous studies suggest that dexmedetomidine has a protective effect against local anaesthetic-induced nerve injury in regional nerve blocks. Whether this potentially protective effect exists in the context of diabetes mellitus is unknown.

Methods

A diabetic state was established in adult male Sprague–Dawley rats with intraperitoneal injection of streptozotocin. Injections of ropivacaine 0.5%, dexmedetomidine 20 μg kg?1 (alone and in combination), or normal saline (all in 0.2 ml) were made around the sciatic nerve in control and diabetic rats (n=8 per group). The duration of sensory and motor nerve block and the motor nerve conduction velocity (MNCV) were determined. Sciatic nerves were harvested at post-injection day 7 and assessed with light and electron microscopy or used for pro-inflammatory cytokine measurements.

Results

Ropivacaine and dexmedetomidine alone or in combination did not produce nerve fibre damage in control non-diabetic rats. In diabetic rats, ropivacaine induced significant nerve fibre damage, which was enhanced by dexmedetomidine. This manifested with slowed MNCV, decreased axon density, and decreased ratio of inner to outer diameter of the myelin sheath (G ratio). Demyelination, axon disappearance, and empty vacuoles were also found using electron microscopy. An associated increase in nerve interleukin-1β and tumour necrosis factor-α was also seen.

Conclusions

Ropivacaine 0.5% causes significant sciatic nerve injury in diabetic rats that is greatly potentiated by high-dose dexmedetomidine. Although the dose of dexmedetomidine used in this study is considerably higher than that used in clinical practice, our data suggest that further studies to assess ropivacaine (alone and in combination with dexmedetomidine) use for peripheral nerve blockade in diabetic patients are warranted.  相似文献   
25.
《Journal of hand therapy》2019,32(3):334-344.e1
Study DesignGrounded theory.IntroductionThe broader perspective of health offered by the World Health Organization's International Classification of Functioning, Disability and Health has had a significant bearing on how we view the measurement of health outcomes after surgical or therapy interventions for peripheral nerve disorders affecting the hand. The value of the patient's perspective is now recognized and outcomes which reflect this are being advocated in the clinical management and support of this population.Purpose of the StudyThis qualitative study sought to explore the lived experience of a hand nerve disorder and in particular the impact on body structure/function, activities, and participation.MethodsIn depth, one-to-one interviews with 14 people with a range of hand nerve disorders were conducted. Constructivist grounded theory methods were used to collect and analyze the data. Patients were also given the option of taking photographs to visually represent what it is like to live with a nerve disorder, to bring with them for discussion during the interview.ResultsThe impact of hand nerve disorders forms part of a wider narrative on adaptation. A process of “struggling” and then “overcoming” was experienced. This was followed by an interior aspect of adaptation described as “accepting.” This gave rise to participants “transforming,” being changed as a result of the journey that they had been on.ConclusionsThis study provides an explanatory theory on the adaptive process following a hand nerve disorder which may inform future patient-therapist interactions.  相似文献   
26.
27.
28.
29.
30.
近年来,腰椎间盘突出症发病率逐渐增高,由于动物模型对于阐明疾病发病机制及评估新的治疗方法具有重要作用,越来越多的学者开始研究如何建立合适的、能够更好地模拟人类腰椎间盘突出的动物模型。近期的研究多选用包括大鼠、兔、羊、猪等动物作为实验对象,通过物理或化学方式直接损伤其椎间盘或神经根,或通过限制实验动物的行为动作、改变其饲养环境以及性别年龄导致的生理因素等方式诱导其出现椎间盘退变。各种造模方法均有其特点及局限性,适用于不同情况,有必要继续完善。  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