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   1439篇
  免费   99篇
  国内免费   11篇
耳鼻咽喉   4篇
儿科学   58篇
妇产科学   28篇
基础医学   189篇
口腔科学   6篇
临床医学   153篇
内科学   412篇
皮肤病学   19篇
神经病学   103篇
特种医学   33篇
外科学   255篇
综合类   4篇
预防医学   80篇
眼科学   13篇
药学   114篇
中国医学   5篇
肿瘤学   73篇
  2022年   17篇
  2021年   57篇
  2020年   22篇
  2019年   31篇
  2018年   46篇
  2017年   24篇
  2016年   31篇
  2015年   34篇
  2014年   39篇
  2013年   56篇
  2012年   81篇
  2011年   108篇
  2010年   46篇
  2009年   46篇
  2008年   65篇
  2007年   46篇
  2006年   61篇
  2005年   71篇
  2004年   61篇
  2003年   66篇
  2002年   50篇
  2001年   43篇
  2000年   38篇
  1999年   40篇
  1998年   16篇
  1996年   10篇
  1993年   9篇
  1992年   22篇
  1991年   20篇
  1990年   19篇
  1989年   16篇
  1988年   13篇
  1987年   11篇
  1986年   13篇
  1985年   15篇
  1984年   8篇
  1983年   8篇
  1980年   9篇
  1979年   12篇
  1978年   12篇
  1976年   12篇
  1975年   9篇
  1974年   10篇
  1973年   14篇
  1972年   13篇
  1971年   9篇
  1970年   10篇
  1969年   9篇
  1968年   9篇
  1966年   8篇
排序方式: 共有1549条查询结果,搜索用时 15 毫秒
21.
A boy of 3 2/12 years of age with Richner-Hanhart syndrome (plantar and palmar keratosis and chronic keratitis) was found to have hypertyrosinemia and to excrete the hydroxyacids derived from tyrosine. A diet poor in phenylalanine and tyrosine cured the skin and corneal lesions. Clinical and biochemical observations are reported.  相似文献   
22.
The anatomy and function of the gluteus minimus muscle   总被引:1,自引:0,他引:1  
In order to investigate the functional anatomy of gluteus minimus we dissected 16 hips in fresh cadavers. The muscle originates from the external aspect of the ilium, between the anterior and inferior gluteal lines, and also at the sciatic notch from the inside of the pelvis where it protects the superior gluteal nerve and artery. It inserts anterosuperiorly into the capsule of the hip and continues to its main insertion on the greater trochanter. Based on these anatomical findings, a model was developed using plastic bones. A study of its mechanics showed that gluteus minimus acts as a flexor, an abductor and an internal or external rotator, depending on the position of the femur and which part of the muscle is active. It follows that one of its functions is to stabilise the head of the femur in the acetabulum by tightening the capsule and applying pressure on the head. Careful preservation or reattachment of the tendon of gluteus minimus during surgery on the hip is strongly recommended.  相似文献   
23.
Cytomegalovirus (CMV) infection in solid-organ transplantation is associated with increased morbidity and mortality, particularly if a CMV mutant strain with antiviral resistance emerges. Monitoring CMV–specific T cell response could provide relevant information for patient care. We and others have shown the involvement of Vδ2neg γδ T cells in controlling CMV infection. Here, we assessed if Vδ2neg γδ T cell kinetics in peripheral blood predict CMV infection resolution and emergence of a mutant strain in high–risk recipients of kidney transplants, including 168 seronegative recipients receiving organs from seropositive donors (D+R−) and 104 seropositive recipients receiving antithymocyte globulins (R+/ATG). Vδ2neg γδ T cell percentages were serially determined in patients grafted between 2003 and 2011. The growing phase of Vδ2neg γδ T cells was monitored in each infected patient, and the expansion rate during this phase was estimated individually by a linear mixed model. A Vδ2neg γδ T cell expansion rate of ˃0.06% per day predicted the growing phase. The time after infection at which an expansion rate of 0.06% per day occurred was correlated with the resolution of CMV DNAemia (r=0.91; P<0.001). At 49 days of antiviral treatment, Vδ2neg γδ T cell expansion onset was associated with recovery, whereas absence of expansion was associated with recurrent disease and DNAemia. The appearance of antiviral–resistant mutant CMV strains was associated with delayed Vδ2neg γδ T cell expansion (P<0.001). In conclusion, longitudinal surveillance of Vδ2neg γδ T cells in recipients of kidney transplants may predict CMV infection resolution and antiviral drug resistance.  相似文献   
24.
25.
26.
27.
Upper extremity digital ischaemia (UEDI) is a rare heterogeneous condition whose frequency is 40 times less than that of toe ischaemia. Using a large cohort, the aim of this study was to evaluate aetiologies, prognosis and midterm clinical outcomes of UEDI.All patients with UEDI with or without cutaneous necrosis in a university hospital setting between January 2000 to December 2016 were included. Aetiologies, recurrence of UEDI, digital amputation and survival were analyzed retrospectively.Three hundred twenty three patients were included. UEDI due to cardio-embolic disease (DICE) was the highest occurring aetiology with 59 patients (18.3%), followed by DI due to Systemic Sclerosis (SSc) (16.1%), idiopathic causes (11.7%), Thromboangiitis obliterans (TAO) (9.3%), iatrogenic causes (9.3%), and cancer (6.2%). DICE patients tended to be older and featured more cases with arterial hypertension whereas TAO patients smoked more tobacco and cannabis. During follow-up, recurrences were significantly more frequent in SSc than in all other tested groups (P < .0001 vs idiopathic and DICE, P = .003 vs TAO) and among TAO patients when compared to DICE patients (P = .005). The cumulated rate of digital amputation was higher in the SSc group (n = 18) (P = .02) and the TAO group (n = 7) (P = .03) than in DICE (n = 2).This retrospective study suggests that main aetiologies of UEDI are DICE, SSc and idiopathic. This study highlights higher frequency of iatrogenic UEDI than previous studies. UEDI associated with SSc has a poor local prognosis (amputations and recurrences) and DICE a poor survival. UEDI with SSc and TAO are frequently recurrent.  相似文献   
28.
Voltage-gated calcium channels have an important role in neurotransmission. Aberrations affecting genes encoding the alpha subunit of these channels have been associated with epilepsy and neuropsychiatric disorders such as autism or schizophrenia. Here we report three patients with a genomic aberration affecting the CACNA2D1 gene encoding the α2δ subunit of these voltage-gated calcium channels. All three patients present with epilepsy and intellectual disability pinpointing the CACNA2D1 gene as an interesting candidate gene for these clinical features. Besides these characteristics, patient 2 also presents with obesity with hyperinsulinism, which is very likely to be caused by deletion of the CD36 gene.  相似文献   
29.

Background

Lumbar-flexion-based endurance training, namely cycling, could be effective in reducing pain and improving function and health-related quality of life in older people with chronic low back pain.

Objectives

To assess barriers and facilitators to home-based cycling in older patients with lumbar spinal stenosis (LSS).

Methods

We conducted a retrospective mixed-method study. Patients  50 years old followed up for LSS from November 2015 to June 2016 in a French tertiary care center were screened. The intervention consisted of a single supervised session followed by home-based sessions of cycling, with dose (number of sessions and duration, distance and power per session) self-determined by patient preference. The primary outcome was assessed by a qualitative approach using semi-structured interviews at baseline and 3 months and was the identification of barriers and facilitators to the intervention. Secondary outcomes were assessed by a quantitative approach and were adherence monitored by a USB stick connected to the bicycle, burden of treatment assessed by the Exercise Therapy Burden Questionnaire (ETBQ) and clinical efficacy assessed by change in lumbar pain, radicular pain, disability, spine-specific activity limitation and maximum walking distance at 3 months.

Results

Overall, 15 patients were included and data for 12 were analyzed at 3 months. At baseline, the mean age was 70.9 years (95% CI: 64.9–76.8) and 9/15 patients (60.0%) were women. Barriers to cycling were fear of pain and fatigue, a too large bicycle, burden of hospital follow-up and lack of time and motivation. Facilitators were clinical improvement, surveillance and ease-of-use of the bicycle. Adherence remained stable overtime. The burden of treatment was low [mean ETBQ score: 21.0 (95% confidence interval: 11.5–30.5)]. At 3 months, 7/12 patients (58.3%) self-reported clinical improvement, with reduced radicular pain and disability [mean absolute differences: ?27.5 (?43.3 to ?11.7), P < 0.01 and ?17.5 (?32.1 to ?2.9), P = 0.01, respectively].

Conclusions

For people with LSS, home-based cycling is a feasible intervention.  相似文献   
30.

A substantial number of epileptic patients are resistant to the current medication thus necessitating the search for alternative therapies for intractable forms of the disease. Previous studies demonstrated the acute anticonvulsant properties of the methanol extract of the stem bark of Psychotria camptopus (MEPC) in rats. This study investigated the effects of MEPC on pentylenetetrazole-kindled Wistar rats. Kindling was induced by intraperitoneal injection of pentylenetetrazole (37.5 mg/kg) on every alternate day, 1 h after each daily oral pretreatment of rats (8?≤?n?≤?10) with MEPC (40, 80 and 120 mg/kg), vehicle or diazepam (3 mg/kg) for 43 days. The kindling development was monitored based on seizure episodes and severity. Rats’ brains were collected on day 43 for the determination of oxidative stress parameters. The histomorphological features and neuronal cell viability of the prefrontal cortex (PFC) and hippocampus were also assessed using H&E and Cresyl violet stains. Chronic administration of pentylenetetrazole time-dependently decreased the latency to myoclonic and generalized seizures, and increased seizure scores and the number of kindled rats. MEPC and diazepam significantly increased the latencies to myoclonic jerks and generalized tonic-clonic seizures. These substances also reduced seizure score and the number of rats with PTZ-kindling. MEPC improved glutathione status and decreased lipid peroxidation in the brains of kindled rats. MEPC also exhibited neuroprotection against pentylenetetrazole-induced hippocampal and PFC neuronal damages. These results suggest that P. camptopus has antiepileptogenic activity, which might be related to the augmentation of antioxidant and neuroprotective defense mechanisms, and further confirm its usefulness in the management of epilepsy.

  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