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   265篇
  免费   8篇
  国内免费   2篇
耳鼻咽喉   6篇
儿科学   6篇
妇产科学   9篇
基础医学   29篇
临床医学   41篇
内科学   60篇
皮肤病学   1篇
神经病学   5篇
特种医学   2篇
外科学   75篇
综合类   4篇
预防医学   5篇
眼科学   3篇
药学   18篇
肿瘤学   11篇
  2023年   2篇
  2022年   3篇
  2021年   1篇
  2019年   1篇
  2018年   4篇
  2017年   1篇
  2016年   2篇
  2015年   5篇
  2014年   4篇
  2013年   8篇
  2012年   12篇
  2011年   17篇
  2010年   5篇
  2009年   11篇
  2008年   14篇
  2007年   16篇
  2006年   18篇
  2005年   19篇
  2004年   15篇
  2003年   7篇
  2002年   19篇
  2001年   5篇
  2000年   14篇
  1999年   12篇
  1998年   3篇
  1997年   3篇
  1996年   2篇
  1995年   6篇
  1994年   1篇
  1993年   3篇
  1992年   5篇
  1991年   5篇
  1990年   4篇
  1989年   6篇
  1987年   4篇
  1986年   3篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1980年   1篇
  1977年   1篇
  1976年   2篇
  1975年   1篇
  1974年   2篇
  1968年   2篇
  1967年   1篇
  1965年   1篇
排序方式: 共有275条查询结果,搜索用时 15 毫秒
1.
This study demonstrates that ZnSO4 induced chemical trauma results in an in situ regeneration of the olfactory epithelium which, when maintained in vitro, provides an enriched population of olfactory neurons. Therefore, the ability of the olfactory epithelium to respond to chemical trauma with increased mitotic activity can be used to increase growth of neurons in culture. Tissue obtained from normal or vehicle-treated adult mice produced few olfactory neurons, when maintained in culture, compared to cultures established from tissue following an in situ ZnSO4 trauma. Maximal neuronal yields were obtained in cultures established from tissue that was removed 4–6 days following chemical trauma. The morphological appearance and the presence of cell specific intermediate filament proteins were used to classify the cell types in these olfactory epithelial cultures. Single cells and aggregates of cells which were immunopositive for keratin, but immunonegative for neurofilament protein and GFAP, were identified as epithelioid. Flattened polygonal cells immunopositive for GFAP were identified as glia. A small population of flattened cells was immunonegative for all of the antibodies used in this study. Cells that had processes were immunonegative for GFAP and keratin. Some were immunopositive for 200 kDa and 160 kDa neurofilament proteins but immunonegative for the 68 kDa neurofilament protein. A few of these cells showed positive immunoreactivity with the olfactory marker protein (OMP) antibody and most likely represented the most mature olfactory neurons in the cultures. This trauma-induced culture model using olfactory tissue from adult mice can serve as a source of CNS neurons for comparison with cultured embryonic neurons.  相似文献   
2.

Background  

Veno-arterial extracorporeal membrane oxygenation (ECMO) is a common modality of circulatory assist device used in children. We assessed the outcome of children who had ECMO following repair of congenital cardiac defects (CCD) and identified the risk factors associated with hospital mortality.  相似文献   
3.
Active-Passive Coping and Skin Conductance and Heart Rate Changes   总被引:1,自引:0,他引:1  
Sixty subjects were administered 33 tasks, selected from the Raven Progressive Matrices, in conditions that differed by type of monetary reinforcement (reward, frustration, and control group). Subjects were tested in pairs. One subject, assigned as the active one, was asked to solve a problem while the other was only a passive observer. Heart rate level and the amplitude of evoked skin conductance responses were measured. Statistical analysis detected a higher heart rate level in active versus passive subjects at the beginning stage of the experiment, as well as a faster heart rate decrease in the former versus the latter group during subsequent blocks of four tasks. Changes in skin conductance response magnitude during the ensuing task phases exhibited a descending trend in passive subjects and an ascending trend in active subjects. The monetary reinforcement manipulation was not effective. The results support a concept put forward by Fowles (1988), who maintained that tonic heart rate and skin conductance response amplitude may serve as indices of the behavioral activation system and behavioral inhibition system, respectively, as postulated by Gray's model of arousal.  相似文献   
4.
The synthesis of highly uniform (1,08 ≤ M w/M n ≤ 1,13) telechelic poly(ε-caprolactone) terminated at both ends with OH groups and its derivatization leading to poly(ε-caprolactone) with pyrene end-groups are described. The synthesis, carried out in THF at room temperature, involves initiation with (CH3CH2)2AlO(CH2CH2O)3Al(CH2CH3)2, leading to poly(ε-caprolactone) macromolecules growing at both ends. The active centers were deactivated with acetic acid, giving macromolecules with OH end-groups. Reaction of α,ω-dihydroxypoly(ε-caprolactone), HO-poly(εCL)-OH, with 4-(1-pyrenyl)butyryl chloride yields α,ω-di-1-pyrenylpoly(ε-caprolactone), Py-poly(εCL)-Py. Polymers are characterized by GPC, 1H NMR, and UV spectroscopies. The UV spectra of polymers with pyrene end-groups are compared with the UV spectra of the model compound.  相似文献   
5.
Venovenous extracorporeal membrane oxygenation with lepirudin anticoagulation was successfully used for a complicated case of Wegener's granulomatosis and heparin-induced thrombocytopenia. Interestingly, a linear correlation was found between activated partial thromboplastin time and activated clotting time during lepirudin anticoagulation.  相似文献   
6.
The effect of large-dose prednisone therapy (3960 mg over 56 days) on humoral immunological markers and MRI pattern was studied in 25 patients with clinically definite multiple sclerosis. There was a decrease in levels of some studied markers (TNF in CSF, MBP level, IgG index, kappa chains in urine and kappa/creatinine ratio) after the treatment, but the differences reached statistical significance in some groups only. The decrease of total lesion area in MRI was not statistically significant. The obtained results proved clearly, that the above mentioned immunological markers might be helpful for monitoring of therapy in MS patients.  相似文献   
7.
8.
We have demonstrated that controlled electric fields can be used to regulate transport, concentration, hybridization, and denaturation of single- and double-stranded oligonucleotides. Discrimination among oligonucleotide hybrids with widely varying binding strengths may be attained by simple adjustment of the electric field strength. When this approach is used, electric field denaturation control allows single base pair mismatch discrimination to be carried out rapidly (<15 sec) and with high resolution. Electric field denaturation takes place at temperatures well below the melting point of the hybrids, and it may constitute a novel mechanism of DNA denaturation.  相似文献   
9.
The CYP2B1/cyclophosphamide (CPA) suicide gene therapy approach has been shown to be highly promising in clinical trials for the treatment of pancreatic cancer. However, delivering the therapeutic gene to a sufficient number of tumor cells able to trigger a complete response remains a challenge. Target-specific delivery of adenovirus to fibroblast growth factor receptors (FGFRs) has been obtained in a variety of tumor models and has been shown to highly increase transduction efficiency. In the present paper we have tested the therapeutic outcome of retargeting the adenoviral vector, Ad-CYP2B1, to FGFRs, using an FGF2-Fab' conjugate, in pancreatic cancer models. First, we show a heterogeneous subcellular distribution of overexpressed FGFR-1 in pancreatic cancer cells. Higher transduction efficiency was observed in five of the six cell lines studied after FGF2-AdGFPLuc infection. Interestingly, an association between FGFR-1 membrane cell expression and viral entry was found. Moreover, tumors injected with FGF2-AdGFPLuc showed enhanced and persistent transgene expression. Importantly, we demonstrate the relevant enhanced cytotoxic effect of the FGF2-Ad-CYP2B]/CPA system in four of the six cell lines studied. Moreover, retargeting Ad-CYP2B1/CPA to FGFRs resulted in a potent antitumoral effect and in an increased survival rate, in two human pancreatic xenograft models. Thus, our results indicate that redirecting adenoviruses to FGFRs highly increases the potency of the suicide system CYP2B1/CPA. Consequently, it may constitute a promising approach to the treatment of patients with pancreatic tumors, in which a high proportion of FGF receptors precisely localize to the plasma membrane.  相似文献   
10.
Pregnancy co-existing with a complete transverse spinal cord lesion is a very rare case not commonly encountered in everyday clinical practice. The management of pregnancy, delivery, and puerperium poses great difficulties requiring interdisciplinary solutions. The authors present the course of delivery and puerperium in a woman with transverse SCI following traumatic injury to Th4-Th5.  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