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   440篇
  免费   46篇
  国内免费   3篇
耳鼻咽喉   1篇
儿科学   9篇
妇产科学   6篇
基础医学   62篇
口腔科学   47篇
临床医学   36篇
内科学   113篇
皮肤病学   2篇
神经病学   22篇
特种医学   14篇
外科学   64篇
综合类   4篇
预防医学   60篇
眼科学   1篇
药学   37篇
肿瘤学   11篇
  2023年   8篇
  2022年   8篇
  2021年   15篇
  2020年   9篇
  2019年   15篇
  2018年   20篇
  2017年   15篇
  2016年   19篇
  2015年   9篇
  2014年   9篇
  2013年   19篇
  2012年   30篇
  2011年   35篇
  2010年   14篇
  2009年   17篇
  2008年   18篇
  2007年   22篇
  2006年   32篇
  2005年   17篇
  2004年   26篇
  2003年   36篇
  2002年   24篇
  2001年   4篇
  2000年   3篇
  1999年   3篇
  1998年   7篇
  1997年   2篇
  1996年   3篇
  1995年   4篇
  1994年   4篇
  1993年   4篇
  1992年   1篇
  1991年   2篇
  1990年   2篇
  1989年   4篇
  1988年   5篇
  1987年   5篇
  1985年   1篇
  1984年   2篇
  1983年   4篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1977年   2篇
  1971年   1篇
  1970年   1篇
  1968年   1篇
  1967年   3篇
  1965年   1篇
排序方式: 共有489条查询结果,搜索用时 15 毫秒
91.
Rhabdomyosarcoma (RMS) typically arises from skeletal muscle. Currently, RMS in patients with recurrent and metastatic disease have no successful treatment. The molecular pathogenesis of RMS varies based on cancer sub-types. Some embryonal RMS but not other sub-types are driven by sonic hedgehog (Shh) signaling pathway. However, Shh pathway inhibitors particularly smoothened inhibitors are not highly effective in animals. Here, we show that Shh pathway effectors GLI1 and/or GLI2 are over-expressed in the majority of RMS cells and that GANT-61, a specific GLI1/2 inhibitor dampens the proliferation of both embryonal and alveolar RMS cells-derived xenograft tumors thereby blocking their growth. As compared to vehicle-treated control, about 50% tumor growth inhibition occurs in mice receiving GANT-61 treatment. The proliferation inhibition was associated with slowing of cell cycle progression which was mediated by the reduced expression of cyclins D1/2/3 & E and the concomitant induction of p21. GANT-61 not only reduced expression of GLI1/2 in these RMS but also significantly diminished AKT/mTOR signaling. The therapeutic action of GANT-61 was significantly augmented when combined with chemotherapeutic agents employed for RMS therapy such as temsirolimus or vincristine. Finally, reduced expression of proteins driving epithelial mesenchymal transition (EMT) characterized the residual tumors.  相似文献   
92.
Five pregnant growing rats were orbited for 5 days aboard the Soviet COSMOS 1514 biologic satellite. The bone effects of weightlessness were studied and compared to those of five pregnant rats kept in vivarium and five pregnant conditioned rats. Bone histomorphometric studies were performed to investigate the early effects of weightlessness in loaded (tibia-femur) and unloaded (thoracic and lumbar vertebrae) bones. A short exposure to weightlessness does not induce any change in bone mass and inner structure in either type of bone. In unloaded bones, the number of osteoclasts per square millimeter of the trabecular surface significantly increased when measured after histochemical demonstration of tartrate-resistant acid phosphatase. It is likely that a stimulation of bone resorption activity occurs in the trabeculae of unloaded bones during the early phase of a spaceflight. In tibia, osteoid seam thickness and total osteoclastic resorption surfaces at the endosteal level were not modified.  相似文献   
93.
94.
95.
Several potent and selective A2A adenosine receptor agonists are currently available. These compounds have a high affinity for the A2A receptor and a long duration of action. However, in situations where a short duration of action is desired, currently available A2A receptor agonists are less than ideal. From a series of recently synthesized A2A receptor agonists, two agonists (CVT-3146 and CVT-3033) with low affinity were selected for further characterization as selective and short-acting coronary vasodilators. Both compounds were selective for the A2A adenosine receptor (AdoR) versus the A1, A2B, and A3AdoR in binding and functional studies. CVT-3146 and CVT-3033 appeared to be weak partial agonists to cause cAMP accumulation in PC12 cells, but were full and potent agonists to cause coronary vasodilation, a response that has a very large A2A receptor reserve. However, the durations of action of CVT-3146 and CVT-3033 were remarkably shorter than those of the high-affinity agonists CGS21680 or WRC0470, presumably due to the relative lower affinity of CVT-3146 and CVT-3033 for the A2A receptor. Indeed, an inverse relationship was found between the affinity of the various agonists for the A2A receptor and the duration of their actions. These data indicate that low-affinity agonists can produce a response that is of equivalent magnitude but more rapid in termination than that caused by a high-affinity agonist. Hence, the low-affinity A2A agonists CVT-3146 and CVT-3033 may prove to be superior to currently available high-affinity agonists as coronary vasodilators during myocardial imaging with radionuclide agents.  相似文献   
96.
97.
OBJECTIVES: Increased vulnerability to stress has been suggested as a possible mechanism behind medically unexplained conditions such as sensitivity to electricity and common smells. This study examined whether subjective environmental annoyance among the general population is associated with increased physiological reactivity or subjective stress scores. METHODS: Four groups were studied (N=141): an electrically annoyed (N=17), a smell-annoyed (N=29), and a generally annoyed group (N=39) and a reference group matched for age, gender, and socioeconomic status (N=56). Over 5 days, the participants collected saliva for cortisol determination at awakening, 30 minutes after awakening, 8 hours after awakening, and at 9 o'clock in the evening. On the evening preceding the fifth day, the participants ingested a 0.5-mg dexamethasone tablet so that possible differential suppression of the hypothalamic-pituitary-adrenal (HPA) axis could be assessed. Each day, the participants also rated their subjective stress and health complaints. RESULTS: No significant differences were found between the groups regarding cortisol secretion over 5 days. The dexamethasone suppression test showed inhibited cortisol secretion in all four groups. No associations were found between the cortisol concentrations and the self-reported stress scores or subjective health complaints. CONCLUSIONS: Although the environmentally annoyed groups showed no signs of increased HPA-axis activation, being annoyed by both electrical devices and smells seems to be related to increased psychological activation in terms of self-reported stress. Because the participants were otherwise healthy and recruited from the general population, the results imply that subtle psychological stress processes may be important in the early development of environmental annoyance.  相似文献   
98.
Objective To investigate the pharmacological effect of Nyctanthes arbortristis (NAT) leaf extract in the prevention of lung injury induced by silica particles. Method Lung injury was induced in Swiss mice through inhalation exposure to silica particles (<5μ) using a Flow Past Nose Only Inhalation Chamber at the rate of -10 mg/m3 respirable mass for 5 h. Lung bronchoalveolar lavage (BAL) fluid collected between 48 and 72 h was subjected to protein profiling by electrophoresis and cytokine evaluation by solid phase sandwich ELISA. Lung histopathology was performed to evaluate lung injury. Results Inhalation of silica increased the level of tumor necrosis factor-α(TNF-α), and of the 66 and 63 kDa peptides in the BAL fluid in comparison to sham-treated control. Pre-treatment of silica exposed mice with NAT leaf extract significantly prevented the accumulation of TNF-α in the BAL fluid, but the 66 and 63 kDa peptides remained unchanged. The extract was also effective in the prevention of silica-induced early fibrogenic reactions like congestion, edema and infiltration of nucleated cells in the interstitial alveolar spaces, and thickening of alveolar septa in mouse lung. Conclusion NAT leaf extract helps in bypassing silica induced initial lung injury in mice.  相似文献   
99.
This study evaluates a rehabilitation program designed to address the social function issues of patients with solvent-induced chronic toxic encephalopathy (TE) and their families. Fourteen newly diagnosed men and their spouses participated in group sessions. The patients were given cognitive training, and crisis intervention measures were implemented. Their spouses were given information about the disease and had an opportunity to talk about their emotions and the disease's impact on the family's functioning. Interviews after the program showed that patients and their spouses were experiencing less psychological distress and increased social activity and had begun reestablishing contacts with friends. Their psychiatric symptoms, measured during a structured interview by a nurse, decreased significantly immediately after the treatment period but increased again after 6 months. Only a long-term follow-up study comparing the experiences of these patients with those of untreated TE patients can determine whether improvement can be sustained over the long term.  相似文献   
100.
A chewing gum containing the antifungal drug miconazole may be convenient for topical treatment of oral candidosis. Therefore a trial was performed to examine the effect and tolerance of miconazole chewing gum in comparison with miconazole gel in the treatment of oral candidosis. The study group consisted of 32 patients with oral candidosis harboring yeasts, predominantly Candida spp. Half of the patients chewed one piece of chewing gum (dose: 3.6 mg of miconazole) four times daily; the other half dispersed a 2% gel (dose: 50 mg of miconazole) in the oral cavity four times daily. After 6 wk of treatment, there was no clinical evidence of yeast infection in either of the two groups. No significant differences between the two groups were found in clinical, mycologic, and cytologic investigations conducted after 3 and 6 wk of treatment or at the follow-up examination 4 wk after termination of the treatment. The results indicate that miconazole released from chewing gum is as effective as miconazole gel. The chewing gum reduced the dosage of miconazole for treatment of oral candidosis, and the patients approved the chewing gum as a pleasant medicament.  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