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   2895篇
  免费   343篇
  国内免费   5篇
耳鼻咽喉   27篇
儿科学   178篇
妇产科学   59篇
基础医学   436篇
口腔科学   9篇
临床医学   337篇
内科学   728篇
皮肤病学   24篇
神经病学   258篇
特种医学   52篇
外科学   317篇
综合类   66篇
一般理论   6篇
预防医学   337篇
眼科学   34篇
药学   238篇
中国医学   3篇
肿瘤学   134篇
  2023年   23篇
  2022年   33篇
  2021年   88篇
  2020年   53篇
  2019年   63篇
  2018年   79篇
  2017年   50篇
  2016年   67篇
  2015年   76篇
  2014年   107篇
  2013年   101篇
  2012年   159篇
  2011年   181篇
  2010年   97篇
  2009年   78篇
  2008年   140篇
  2007年   156篇
  2006年   139篇
  2005年   119篇
  2004年   115篇
  2003年   107篇
  2002年   123篇
  2001年   69篇
  2000年   72篇
  1999年   58篇
  1998年   35篇
  1997年   22篇
  1996年   33篇
  1995年   29篇
  1994年   20篇
  1993年   23篇
  1992年   55篇
  1991年   44篇
  1990年   34篇
  1989年   38篇
  1988年   39篇
  1987年   38篇
  1986年   24篇
  1985年   32篇
  1984年   32篇
  1983年   22篇
  1982年   20篇
  1979年   38篇
  1978年   32篇
  1977年   30篇
  1975年   20篇
  1974年   27篇
  1972年   26篇
  1971年   23篇
  1969年   24篇
排序方式: 共有3243条查询结果,搜索用时 15 毫秒
71.

Objective

Adverse events (AEs) are health related events, reported by participants in clinical trials. We describe AEs in the PACE trial of treatments for chronic fatigue syndrome (CFS) and baseline characteristics associated with them.

Methods

AEs were recorded on three occasions over one year in 641 participants. We compared the numbers and nature of AEs between treatment arms of specialist medical care (SMC) alone, or SMC supplemented by adaptive pacing therapy (APT), cognitive behaviour therapy (CBT) or graded exercise therapy (GET). We examined associations with baseline measures by binary logistic regression analyses, and compared the proportions of participants who deteriorated by clinically important amounts.

Results

Serious adverse events and reactions were infrequent. Non-serious adverse events were common; the median (quartiles) number was 4 (2, 8) per participant, with no significant differences between treatments (P = .47). A greater number of NSAEs were associated with recruitment centre, and baseline physical symptom count, body mass index, and depressive disorder. Physical function deteriorated in 39 (25%) participants after APT, 15 (9%) after CBT, 18 (11%) after GET, and 28 (18%) after SMC (P < .001), with no significant differences in worsening fatigue.

Conclusions

The numbers of adverse events did not differ significantly between trial treatments, but physical deterioration occurred most often after APT. The reporting of non-serious adverse events may reflect the nature of the illness rather than the effect of treatments. Differences between centres suggest that both standardisation of ascertainment methods and training are important when collecting adverse event data.  相似文献   
72.
Cumulative evidence indicates that song sparrows, Melospiza melodia morphna, of western Washington State prefer territories close to water. Densities of territories were higher within 50m of open water and analysis of stomach contents revealed aquatic organisms. An unusually dry period (less open water) in May and June 1997 had no effect on latency of territorial males to respond to a simulated territorial intrusion (STI), but the number of songs and closest approach to the decoy were lower than those recorded in June 1988 (no major dry periods). A laboratory experiment was conducted in which males and females were exposed to long days to stimulate reproductive development. One group received a bath with water daily and the other group received a dry bath (both groups had ad libitum access to drinking water through a glass tube). Birds with a dry bath tended to show reduced photoperiodically-induced gonadal growth compared with birds that had access to water in the bath. Plasma levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) increased following photostimulation in all groups. However, LH levels were higher in females with access to water. There were no differences in hormone levels in any of the other groups. Taken together these novel data indicate that presence and access to open water could be an important environmental cue for song sparrows in western Washington State. Implications for global climate change and droughts are suggested.  相似文献   
73.
74.
Recently, nontumor specific circulating DNA was shown to be elevated in a broad range of lymphomas, implicating a role as a potential biomarker. Epstein-Barr virus' (EBV) presence within a proportion of lymphomas implies EBV-DNA has potential as a lymphoma-specific disease response biomarker. However, application would be restricted to EBV-associated lymphomas. Neither detailed comparison has been performed of lymphoma-specific versus nonspecific DNA as disease response biomarkers nor have the kinetics of circulating DNA during treatment been established, and the optimal methodology remains unknown. We prospectively evaluated DNA levels and clinical response of 63 lymphoma patients. DNA was measured in paired serum, plasma, and cell samples at five predetermined time-points taken prior, during and following treatment. Both cell-free (c-f) circulating EBV-DNA (in EBV-associated lymphoma) and nonspecific c-f DNA levels (in all lymphomas) were elevated and discriminatory at presentation compared to healthy controls. Nonspecific c-f DNA was significantly associated with baseline serum lactate dehydrogenase. Within EBV-associated lymphomas at presentation, there was a strong correlation between specific and nonspecific circulating c-f DNA (r = 0.9, P < 0.0001). However, only c-f EBV-DNA correlated with clinical/radiological response. In addition, c-f EBV-DNA, and not nonspecific c-f DNA, provided an early marker of relapsed and refractory disease. Serum versus plasma, and single versus multiple-copy EBV-gene targets were equivalent. Lymphoma-specific DNA is a disease response biomarker; however, nonspecific DNA reflected neither lymphoma-specific DNA nor therapeutic response. Lymphoma disease response can be monitored by blood tests, but new lymphoma-specific biomarkers need to be identified to broaden applicability.  相似文献   
75.
76.
77.
This study evaluated four fluorescent-protein conjugates to monitor microcirculatory variables using the murine cremaster muscle and determined acute and long-term responses to repeated administration of FITC-BSA [conjugated at the University of Sheffield (UoS)] within a dorsal microcirculatory chamber (DMC) in rats. For analysis of the cremaster muscle, male C3H/HeN mice were anaesthetized, the cremaster muscle was exteriorized, then TRITC-BSA, TRITC-dextran, FITC-BSA, FITC-BSA (UoS) or FITC-dextran (0.25 ml/100 g) were administered systemically. The microcirculation was viewed with epi-illumination every 10 min for 120 min. For analysis of the DMC, male Wistar rats were implanted with the chamber. Three weeks later, FITC-BSA (UoS) was administered systemically, and the microcirculation response was monitored using three different protocols. In addition, in vitro stability of fluorescent conjugates was measured over 8 h. With regard to the cremaster muscle, initially no differences in interstitial fluorescence or vessel diameter were observed between the four fluorescent conjugates. By the end of the study, interstitial fluorescence from TRITC-dextran, FITC-dextran and FITC-BSA (Sigma) was significantly (p < 0.05) increased compared to FITC-BSA (UoS). With regard to the DMC, there was no interstitial fluorescence leakage after 180 min or 5 weeks despite repeated administration, but a significant (p < 0.05) leak was detected between 4 and 24 h. FITC-BSA (UoS) was the most stable fluorescent conjugate both in vitro and in vivo and was comparable with other conjugates for evaluating skeletal muscle microcirculation using fluorescent in vivo microscopy.  相似文献   
78.
We describe “The Lister Technique”—a new 3 step procedure developed in our department for robotic assisted laparoscopic nephroureterectomy (RANU). Our new technique facilitates the complete excision of the whole ureter including ureteric orifice and reduces this risk of tumour spillage from the distal ureter without the need for bivalving the bladder. Our initial data indicates that the technique is associated with reduction in bladder recurrence post-operatively in comparison to current published series. Longer follow up and larger patient numbers are required to validate these results further.  相似文献   
79.
Male breast cancer (MBC) is unusual, especially in young adults. Most cases of MBC as a secondary malignancy relate to the previous treatment with ionizing radiation. MBC can be associated with mutations in hereditary cancer predisposition syndrome genes (i.e., BRCA2); however, no such association has been reported in patients with Cowden syndrome (involving the phosphatase and tensin homolog [PTEN] gene). We describe a patient with Cowden syndrome who was initially diagnosed with B‐cell lymphoblastic lymphoma at the age of 7 years, then MBC at the age of 31 years, and never received radiation therapy.  相似文献   
80.
The demand for emergency department (ED) services has increased significantly, due to our increasingly ageing population and limited access to primary care. This article reports outcomes from a transprofessional model of care in an ED in Victoria, Australia. Nurses, physiotherapists, social workers, and occupational therapists undertook additional education to increase the range of services they could provide and thereby expedite patient flow through the ED. One hundred patients who received this service were matched against 50 patients who did not. The most common reasons for patient admission were limb injury/limb pain (n = 47, 23.5%) and falls (n = 46, 23.0%). Transprofessional interventions included applying supportive bandages, slings, zimmer splints and controlled ankle motion (CAM) boots, and referral to new services such as case management and mental health teams. The rate of hospital admissions was significantly lower in the transprofessional group (n = 27, 18.0%) than in the reference group (n = 19, 38%, p = 0.005). This group also had a slightly lower re-presentation rate (n = 4, 2.7%) than patients in the reference group (n = 2, 4.0%). There are many benefits that support this model of care that in turn reduces ED overcrowding and work stress. A transprofessional model may offer a creative solution to meeting the varied needs of patients presenting for emergency care.  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