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   3516篇
  免费   180篇
  国内免费   14篇
耳鼻咽喉   39篇
儿科学   159篇
妇产科学   307篇
基础医学   330篇
口腔科学   48篇
临床医学   290篇
内科学   795篇
皮肤病学   37篇
神经病学   307篇
特种医学   99篇
外科学   522篇
综合类   14篇
一般理论   1篇
预防医学   131篇
眼科学   100篇
药学   176篇
中国医学   5篇
肿瘤学   350篇
  2023年   15篇
  2022年   21篇
  2021年   65篇
  2020年   37篇
  2019年   50篇
  2018年   80篇
  2017年   57篇
  2016年   58篇
  2015年   82篇
  2014年   98篇
  2013年   151篇
  2012年   186篇
  2011年   209篇
  2010年   119篇
  2009年   98篇
  2008年   196篇
  2007年   249篇
  2006年   254篇
  2005年   263篇
  2004年   254篇
  2003年   248篇
  2002年   196篇
  2001年   41篇
  2000年   42篇
  1999年   44篇
  1998年   41篇
  1997年   27篇
  1996年   34篇
  1995年   44篇
  1994年   30篇
  1993年   33篇
  1992年   27篇
  1991年   32篇
  1990年   30篇
  1989年   18篇
  1988年   19篇
  1987年   26篇
  1986年   27篇
  1985年   13篇
  1984年   23篇
  1983年   27篇
  1982年   16篇
  1981年   21篇
  1980年   17篇
  1979年   9篇
  1978年   16篇
  1977年   16篇
  1974年   7篇
  1973年   6篇
  1971年   6篇
排序方式: 共有3710条查询结果,搜索用时 15 毫秒
81.
Midodrine is an alpha-agonist that causes peripheral vasoconstriction, resulting in increased blood pressure. It has been reported to be safe and effective in patients with end stage renal disease (ESRD) and is widely used for hemodialysis-associated hypotension. We report a case report of midodrine-induced ischemia in a patient on hemodialysis and review the literature relating to the safety of midodrine in patients with end stage renal disease.  相似文献   
82.
An association between symptomatic compression neuropathy of the median nerve at the carpal tunnel and "trigger finger" has been reported in endocrine and metabolic disorders. We assessed the incidence of increased median nerve latency in subjects with "trigger finger". 62 consecutive patients with "trigger finger" and no signs or symptoms of median nerve compression underwent nerve conduction studies of the median nerve. 13 healthy adults served as controls. 39/62 patients had increased distal motor latency in the median nerve. Only 1 of 13 subjects in the control group had a borderline value of distal motor latency.  相似文献   
83.
Stress and episodic memory impairment have previously been associated. Acute stress disorder (ASD) is a maladaptive stress response, which develops in some individuals following traumatic life events. Recently, the authors demonstrated a specific deficit in associative memory for emotionally neutral stimuli in ASD and posttraumatic stress disorder (PTSD). This study further tested the relationship between this memory impairment and the course of ASD. We assessed new learning and memory for item and associative information in patients diagnosed with ASD (n=14) and matched trauma naïve controls (n=14). Memory performance and posttraumatic symptoms were examined for approximately 1 and 10 week periods following the traumatic experience. In the two experiments, participants studied a list of stimuli pairs (verbal or visual) and were then tested for their memory of the items (item recognition test), or for the association between items in each pair (associative recognition test). In both experiments, ASD patients showed a marked associative memory deficit compared to the control group. After 10 weeks, ASD symptoms were resolved in most patients. Interestingly, their performance on associative recognition for verbal stimuli improved, while the associative deficit for visual stimuli remained unchanged. Potential mechanisms underlying such an associative memory deficit in post-trauma patients are discussed.  相似文献   
84.
This study aimed to examine a multi-mediator model explaining how exposure to parent-child physical aggression may link with adolescents’ peer-directed physical aggression and their own subjective happiness, in an understudied Israeli Arab population. Mediators included hostility, anger, need to belong, and self-control. Arab adolescents from northern Israel (N?=?155; 62 % girls, aged 16-17) completed questionnaires regarding parents’ physical violence toward them, their own aggression toward peers, need to belong, happiness, positive emotions, and selfcontrol skills. (a) Parent-child physical aggression linked positively with peerdirected aggression through the mediating associations of hostility with anger; (b) parent-child physical aggression linked negatively with peer-directed aggression and happiness through the mediation of adolescents’ increased need to belong; and (c) parent-child physical aggression was not directly linked with self-control, but selfcontrol directly linked negatively with peer-directed aggression and positively with happiness. Findings highlight pathways through which parent-child physical aggression may simultaneously influence adolescents’ aggressive behavior and happiness. The mediation detected possible process variables (e.g., yearning for belonging, self-control skills, hostile thoughts, and angry feelings) that researchers and clinicians can consider in designing prevention and treatment interventions to break the inter-generational cycle of violence.  相似文献   
85.
86.
87.
88.
We compared exhaled breath condensate (EBC) and induced sputum (IS) for assessing inflammation in pulmonary diseases in patients with obstructive lung disease (n = 20), persistent cough >6 months (n = 20), interstitial lung disease (n = 25) and controls (n = 10). EBC was collected by suspending a Teflon perfluoroalkoxy tube installed in an ice-filled container and connected to a polypropylene test tube. IS was recovered after 20’ inhalation of 3% saline with an ultrasonic nebulizer, and 300 cells were differentially counted in cytospin Giemsa-stained slides. H202 was measured by a method based on oxidation of phenolsulfonphthalein (phenol red) mediated by horseradish peroxidases and H202. Pulmonary function tests were performed by conventional methods. H202 levels in EBC and % eosinophils in IS were significantly different between groups. A positive and significant correlation was found between % eosinophils in IS and the levels of H202 in EBC for each group and for all patients combined.  相似文献   
89.
Studies of visual function in behaving subjects require that stimuli be positioned reliably on the retina in the presence of eye movements. Fixational eye movements scatter stimuli about the retina, inflating estimates of receptive field dimensions, reducing estimates of peak responses, and blurring maps of receptive field subregions. Scleral search coils are frequently used to measure eye position, but their utility for correcting the effects of fixational eye movements on receptive field maps has been questioned. Using eye coils sutured to the sclera and preamplifiers configured to minimize cable artifacts, we reexamined this issue in two rhesus monkeys. During repeated fixation trials, the eye position signal was used to adjust the stimulus position, compensating for eye movements and correcting the stimulus position to place it at the desired location on the retina. Estimates of response magnitudes and receptive field characteristics in V1 and in LGN were obtained in both compensated and uncompensated conditions. Receptive fields were narrower, with steeper borders, and response amplitudes were higher when eye movement compensation was used. In sum, compensating for eye movements facilitated more precise definition of the receptive field. We also monitored horizontal vergence over long sequences of fixation trials and found the variability to be low, as expected for this precise behavior. Our results imply that eye coil signals can be highly accurate and useful for optimizing visual physiology when rigorous precautions are observed.  相似文献   
90.
Erythropoietin (Epo) is the main erythropoietic hormone. Recombinant human Epo (rHuEpo) is thus used in clinical practice for the treatment of anemia. Accumulating data reveals that Epo exerts pleiotropic activities. We have previously shown an anti-neoplastic activity of Epo in murine multiple myeloma (MM) models, and in MM patients. Our findings that this anti-neoplastic effect operates via CD8+ T lymphocytes led us to hypothesize that Epo possesses a wider range of immunomodulatory functions. Here we demonstrate the effect of Epo on B lymphocyte responses, focusing on three experimental models: (i) tumor-bearing mice, (5T2 MM mouse); (ii) antigen-injected healthy mice; and (iii) antigen-injected transgenic mice (tg6), overexpressing human Epo. In the MM model, despite bone marrow dysfunction, Epo-treated mice retained higher levels of endogenous polyclonal immunoglobulins, compared to their untreated controls. In both Epo-treated wild type and tg6 mice, Epo effect was manifested in the higher levels of splenocyte proliferative response induced in vitro by lipopolysaccharide. Furthermore, these mice had increased in vivo production of anti-dinitrophenyl (DNP) antibodies following immunization with DNP-keyhole limpet hemocyanin. Epo-treated mice showed an enhanced immune response also to the clinically relevant hepatitis B surface antigen. These findings suggest a potential novel use of rHuEpo as an immunomodulator.  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