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   345篇
  免费   29篇
  国内免费   5篇
耳鼻咽喉   1篇
儿科学   13篇
妇产科学   3篇
基础医学   76篇
口腔科学   10篇
临床医学   41篇
内科学   58篇
皮肤病学   4篇
神经病学   30篇
特种医学   29篇
外科学   30篇
综合类   33篇
预防医学   9篇
眼科学   2篇
药学   5篇
肿瘤学   35篇
  2021年   8篇
  2019年   7篇
  2018年   4篇
  2017年   3篇
  2016年   4篇
  2015年   6篇
  2014年   8篇
  2013年   4篇
  2012年   13篇
  2011年   15篇
  2010年   7篇
  2009年   10篇
  2008年   9篇
  2007年   14篇
  2006年   10篇
  2005年   13篇
  2004年   5篇
  2003年   12篇
  2002年   7篇
  2001年   3篇
  2000年   6篇
  1999年   11篇
  1998年   24篇
  1997年   16篇
  1996年   15篇
  1995年   8篇
  1994年   11篇
  1993年   7篇
  1992年   7篇
  1990年   3篇
  1989年   5篇
  1988年   10篇
  1987年   7篇
  1986年   8篇
  1985年   4篇
  1984年   3篇
  1983年   6篇
  1982年   3篇
  1981年   5篇
  1976年   3篇
  1975年   4篇
  1974年   6篇
  1973年   5篇
  1972年   6篇
  1971年   4篇
  1970年   5篇
  1969年   3篇
  1967年   3篇
  1965年   2篇
  1955年   2篇
排序方式: 共有379条查询结果,搜索用时 20 毫秒
81.
The radiological findings of ultrasound, CT and MR of a case of bilateral subacromial bursitis with macroscopic rice bodies is described. The previous literature is also reviewed.  相似文献   
82.
1. During unilateral leg movements performed while standing, it is necessary to displace the center of gravity toward the other leg to maintain equilibrium. In addition, the orientation of particular segments, such as the head and trunk, which are used as reference values for organizing the motor act, needs to be preserved. The aim of the present study was to investigate the coordination between movement, equilibrium, and local posture. 2. Experiments were carried out on standing subjects who were instructed to raise one leg laterally to an angle of 45 degrees in response to a light. Two sources of light placed in front of the subject indicated the side on which the movement was to be performed. Three main aspects of the posturokinetic sequence were investigated in two populations, naive subjects and dancers: 1) The body weight transfer toward the supporting leg was found to have two components: first, a "ballistic" one, initiated by a thrust exerted by the moving leg; and second, an "adjustment" component during which the displacement of the center of gravity (CG) reaches a final position (steady state). An early burst in the gastrocnemius medialis of the moving leg often precedes the onset of the center of pressure change. Two differences between naive subjects and dancers were observed: first, the new CG position was almost reached in one step very near to the end of the ballistic component and required only a short adjustment in dancers, whereas in naive subjects it was reached in two steps, including a much longer adjustment component. Second, the dancers were able to minimize the CG displacement toward the supporting side; this might be because they form a better internal representation of the biomechanical limits of stability because of their long training. 2) The onset of the lateral displacement of the malleolus marker of the moving leg always occurred when the body weight had almost completed its transfer to above the support foot. This shows that the positioning of the CG in a new position compatible with equilibrium maintenance was a prerequisite for the leg movement to be performed. The relative timing of events during the posturokinetic sequence was fairly fixed in the dancers, whereas it varied from one trial to another in the naive subjects. 3) The coordination between movement, equilibrium, and head-trunk orientation involves two control strategies. An "inclination" strategy was used by the naive subjects; this consisted of an external rotation of the supporting leg around the anteroposterior ankle joint axis. A counter-rotation at the neck level ensured the stability of the interorbital line in the horizontal plane.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
83.
Pneumocystis carinii pneumonia (PCP) occurs commonly in immunocompromised patients. Sulfamethoxazole-trimethoprim (SMX-TMP) is effective prophylaxis, although PCP may still occur despite apparently adequate use. We report three cases of PCP which highlight some of the pitfalls of prophylaxis.  相似文献   
84.
A prospective study of 82 patients with acute renal failure was carried out over the last 2 years. Mean age of the patients was 35.6 years (8-82 years). Male to female ratio was 3.5:1. The etiological factors were septicaemia in 18 patients (21.95%), aminoglycoside toxicity in 16 patients (19.51%), open heart surgery in 8 patients (9.76%), volume depletion and blood loss in 12 patients (14.63%), glomerulonephritis in 4 patients (4.88%), renal allograft dysfunction in 4 patients (4.88%), and miscellaneous causes in 20 patients (24.39%). Non-oliguric renal failure was observed in 39.02 per cent cases. Dialysis support was required in 65.8 per cent of the cases; with average 5.6 (4 to 11) dialysis sessions. Four patients of acute renal failure following open heart surgery were given continuous arterio-venous haemofiltration. Overall mortality was 32.5 per cent, septicaemia accounting for 60 per cent of the deaths.KEYWORDS: Antibiotics, Aminoglycoside, Renal failure acute, Septicemia  相似文献   
85.
86.
87.
The lifelong IgG replacement therapy for patients with primary immunedeficiencies (PIDD) may be provided by intravenous (IVIG) or by subcutaneous IgG (SCIG) infusions. We investigated the impact of weekly SCIG self-infusions at home on the health-related quality of life, treatment satisfaction, and preferences in patients treated with IVIG at the hospital/doctor's office (Group A) or at home (Group B) before the study started. Forty-four adult North American PIDD patients were included in the study, 28 patients in Group A and 16 in Group B. Patients in Group A reported significantly less limitations with their work/daily activities, a significantly improved vitality, and better general health. Treatment satisfaction was significantly improved in Group A. The preference for the subcutaneous route and for home therapy was respectively 81% and 90% in Group A. In Group B, 69% preferred the subcutaneous route and 92% home therapy.  相似文献   
88.
Epidermal growth factor receptor (EGFR) is occasionally amplified and/or mutated in non-small cell lung cancer (NSCLC) and can be coexpressed with other members of the HER receptor family to form functional heterodimers. We therefore investigated lung cancer cell lines for alterations in EGFR gene copy number, enhanced expression of EGFR and other HER family members, and EGFR coding sequence mutations and correlated these findings with response to treatment with the EGFR inhibitors and the kinetics of ligand-induced signaling. We show here that somatic deletions in the tyrosine kinase domain of EGFR were associated with increased EGFR gene copy number in NSCLC. Treatment with the specific EGFR tyrosine kinase inhibitors (TKI) gefitinib or erlotinib or the EGFR inhibitory antibody cetuximab induced apoptosis of HCC827, a NSCLC cell line with EGFR gene amplification and an exon 19 deletion. H1819, a NSCLC cell line that expresses high levels of EGFR, ErbB2, and ErbB3 but has wild-type EGFR, showed intermediate sensitivity to TKIs. In both cell lines, ligand-induced receptor tyrosine phosphorylation was delayed and prolonged and AKT was constitutively phosphorylated (but remained inhibitable by EGFR TKI). Thus, in addition to EGFR mutations, other factors in NSCLC cells, such as high expression of ErbB family members, may constitutively activate AKT and sensitize cells to EGFR inhibitors.  相似文献   
89.
常用抗高血压药物对血压的时间生物学特征的影响   总被引:1,自引:0,他引:1  
目的 :探讨 3类常用抗高血压药物对非杓型的高血压病患者BP的时间生物学特征的影响。方法 :共入选非杓型BP分布的高血压病患者 16 1例 ,将其随机分为 3组 ,分别给予赖诺普利 (10mg·d-1) ,非洛地平 (2 5mg·d-1) ,或氢氯噻嗪 (5 0mg·d-1) ,并于治疗前后行 2 4h动态BP监测。采用余弦拟合方法分析治疗前后患者BP时间生物学特征的改变。结果 :赖诺普利组与非洛地平组治疗后 2 4hBP均值明显降低 ,但其振幅、峰值相位无变化 ;氢氯噻嗪治疗降压效果不甚理想 ,但显著增加了患者BP的夜间降低幅度 ,使患者BP由非杓型转变为杓型分布。结论 :氢氯噻嗪治疗可能使非杓型分布的高血压病患者的BP转变为杓型分布 ,从而有助于降低患者相关并发症的发生率。  相似文献   
90.
Chou  HC; Ozawa  S; Fu  PP; Lang  NP; Kadlubar  FF 《Carcinogenesis》1998,19(6):1071-1076
Methyl-hydroxylated metabolites of the potent carcinogen, 7,12- dimethylbenz[a]anthracene (DMBA), namely, 7-hydroxymethyl-12- methylbenz[a]anthracene (7-OH-DMBA), 7-methyl-12- hydroxymethylbenz[a]anthracene (12-OH-DMBA) and 7,12- dihydroxymethylbenz[a]anthracene (7,12-diOH-DMBA), were examined as substrates for sulfotransferase bioactivation in different human tissue cytosols. Hepatic cytosols, which were able to catalyze the 3'- phosphoadenosine 5'-phosphosulfate (PAPS)-dependent DNA binding of 7-OH- DMBA, 12-OH-DMBA and 7,12-diOH-DMBA, were highly sensitive to inhibition by dehydroepiandrosterone (DHEA), a specific substrate for human DHEA-steroid sulfotransferase (IC50 = 5 microM). By comparison, 2,6-dichloro-4-nitrophenol, a potent inhibitor of the thermostable (TS)- phenol and estrogen sulfotransferases, did not have an appreciable inhibitory effect. Neither p-nitrophenol, a high affinity substrate for human TS-phenol and estrogen sulfotransferases, nor dopamine, a specific substrate for the thermolabile (TL)-phenol sulfotransferase, significantly inhibited the DNA binding of 12-OH-DMBA catalyzed by hepatic cytosols. Inter-subject variation (n = 12) of the PAPS- dependent DNA binding of 12-OH- and 7,12-diOH-DMBAs also correlated well with DHEA-sulfotransferase activity (r = 0.90; P < 0.00001 and r = 0.92; P < 0.00001, respectively). This sulfation-dependent metabolic activation was not detected in cytosols from human colon, pancreas, larynx or mammary gland. Both TS- and TL-phenol sulfotransferases were active in human liver and colon but only liver contained DHEA- sulfotransferase activity. These results indicate that the sulfotransferase-mediated activation of the methyl-hydroxylated DMBAs is predominantly catalyzed by DHEA-steroid sulfotransferase in human liver and that TS- and TL-phenol sulfotransferases and estrogen sulfotransferase are not involved in the catalysis.   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