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   247篇
  免费   5篇
儿科学   24篇
妇产科学   3篇
基础医学   32篇
口腔科学   1篇
临床医学   37篇
内科学   60篇
皮肤病学   11篇
神经病学   14篇
外科学   32篇
综合类   2篇
预防医学   2篇
眼科学   1篇
药学   24篇
肿瘤学   9篇
  2017年   2篇
  2016年   4篇
  2015年   3篇
  2014年   4篇
  2013年   2篇
  2012年   4篇
  2011年   2篇
  2010年   7篇
  2009年   7篇
  2008年   5篇
  2007年   6篇
  2006年   8篇
  2005年   8篇
  2004年   5篇
  2003年   5篇
  2002年   5篇
  2001年   2篇
  2000年   1篇
  1999年   4篇
  1998年   21篇
  1997年   24篇
  1996年   22篇
  1995年   14篇
  1994年   11篇
  1993年   11篇
  1992年   4篇
  1991年   3篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1987年   3篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1980年   4篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1969年   1篇
  1959年   2篇
  1958年   4篇
  1957年   9篇
  1956年   4篇
  1955年   7篇
  1954年   6篇
排序方式: 共有252条查询结果,搜索用时 31 毫秒
71.
72.
This report is concerned with an adult presenting with stenoticbicuspid aortic valve associated with a ventricular septal defect(VSD). The association between aortic regurgitation (AR) andVSD has often been described, but that between a stenosed aorticvalve and VSD has been rarely observed, although bicuspid aorticvalves and ventricular septal defects are probably the two mostcommon congenital heart defects. The development of congestiveheart failure in the presented case was considered to be dueto an increase in the left to right shunt through the VSD. Thiswas attributable to a progressive elevation in left ventricularpressure as a result of the development, with age, of stenosisof the bicuspid aortic valve.  相似文献   
73.
目的 探讨去氢表雄酮(DHEA)的体内抗癌作用及其机制.方法 Buffalo大鼠21只随机分为空白对照组、肿瘤对照组(把Morris肝细胞瘤移植到大鼠的两肋皮下,建立Morris肝细胞瘤移植的Buffalo大鼠的体内模型,基础饲料喂养)、DHEA肿瘤组(建立Morris肝细胞瘤移植模型后,在喂养的基础饲料中添加DHEA)和去氢表雄酮硫酸酯(DHEAs)肿瘤组(建立Morris肝细胞瘤移植模型后,在喂养的基础饲料中添加DHEAs).分别喂养4周后,Western blot和免疫组织化学方法检测磷酸化丝/苏氨酸蛋白激酶(Akt)、PTEN等蛋白的表达,流式细胞术检测大鼠CD3,CD4、CD8和CD4/CD8.单因素方差分析对数据进行处理.结果 DHEA肿瘤组的肝细胞瘤的质量为(8.31±0.61)g,较肿瘤对照组的(14.57±0.56)g显著减轻(P<0.05).Westem blot及免疫组织化学染色结果显示,DHEA肿瘤组的磷酸化Akt蛋白表达量降低,而PTEN蛋白表达增强;CD3阳性细胞百分率(74.97%±8.29%)较肿瘤对照组(56.45%±6.12%)明显提高(t=4.92,P<0.05),CD4/CD8比值升高(1.75±0.22).而DHEAs肿瘤组CD3阳性细胞百分率(60.04%±6.69%)较空白对照组(75.38%±9.76%)明显降低(t=3.87,P<0.05),同时CD4/CD8比值也降低(1.48±0.56).结论 DHEA对体内的肿瘤具有明显的抑制作用,此作用可能是其通过调节体内的Akt信号传导通路和免疫功能来完成的.  相似文献   
74.
Arteriovenous malformation (AVM) is a structural vascular abnormality with no proliferation of cellular components. We report on a 53‐year‐old man who presented with a 15‐year history of a progressively enlarging nodule on his lower lip. A dark‐reddish, easy‐bleeding nodule diagnosed as AVM was resected to reduce the volume and troublesome bleeding. Histologically, the nodule revealed that the proliferating cellular area was composed of endothelial cells and pericytes in addition to the area of dilated vessels. We speculated that the cell proliferation developed secondary to AVM. We also discuss the histological differential diagnosis of spindle cell hemangioma and pseudo‐Kaposi’s sarcoma.  相似文献   
75.
The distribution of human herpesvirus 6 (HHV-6) and varicella-zoster virus (VZV) was examined in autopsy samples from a fatal case with both virus infections. A 9-month-old boy developed convulsive seizures followed by macular skin rashes, rapidly progressed to brain death, and died 15 days after the onset, when signs of varicella were noted. An isolation of HHV-6 from blood and evaluation of antibody activities to various viral agents including HHV-6 were performed before his death. Postmortem examinations included: (i) isolation of HHV-6 and VZV from tissues or organs; (ii) detection of both virus antigens in tissues or organs by an indirect immunofluorescent assay using monoclonal antibodies to both viruses; (iii) amplification of both viruses and human herpesvirus 7 DNA sequences by a nested polymerase chain reaction assay; and (iv) endonuclease digestion of amplified products of HHV-6 DNA for differentation of variants A and B. Human herpesvirus 6 DNA was detected in peripheral blood mononuclear cells (PBMC) and plasma obtained at the eruptive stage but present only in PBMC 15 days after, indicating the primary infection with HHV-6, although the virus was not isolated from the same blood sample and a significant rise in the antibody titers to HHV-6 was not observed. Both virus antigens and DNA were detected in various tissues or organs obtained at autopsy, but only VZV was isolated from these samples, suggesting disseminated infection with both viruses in an infant. All the amplified products of HHV-6 DNA were variant B. Among the findings for the distribution of virus antigens, it was noteworthy that HHV-6 antigen was demonstrated in the endothelial cells of small vessels in the frontal lobe of the brain. There was no evidence of HHV-7 infection. These data indicate that the primary HHV-6 infection closely followed by the primary VZV infection had the potential hazard of an unexpected and apparently life-threatening event, in which disseminated infections with both viruses were noted in multiple tissues or organs including the brain.  相似文献   
76.
Villoglandular papillary adenocarcinoma (VGPA) of the uterine cervix is a rare neoplasm, and its treatment has rarely been reported. We report a patient with VGPA stage IIA responding to neoadjuvant chemotherapy with docetaxel (60 mg/m2 as an intravenous infusion) and cisplatin (70 mg/m2 as an intra-arterial infusion). At 3 weeks after completing one course of this regimen, the tumor size was reduced from 5.3 x 4.0 cm to 2.0 x 2.0 cm (81.1% reduction), revealed by computed tomography. Accordingly, the patient underwent radical hysterectomy, and there have been no signs of recurrence. Thus, the combination of docetaxel and cisplatin is suggested to be useful for neoadjuvant chemotherapy of cervical adenocarcinoma.  相似文献   
77.
In 44 neonates (mean birthweight 1207 g and mean gestational age 30.0 weeks), very small central venous catheters were percutaneously inserted via the great saphenous vein on 46 occasions. Catheter-related complications such as catheter blockages in 17 (37%), edema in a unilateral leg in three (6%), and mechanical disruption in two (4%) were noted. Although two of the neonates were found to have bacteremia and five neonates died, none were catheter related. The optimal length of catheter insertion (Y) from the great saphenous vein at the level of the medial maleollus to the inferior vena cava at T9 and L3 was calculated by regression equations utilizing total body length (X). Radiographs taken with extended and flexed leg postures revealed that the catheter tips were retracted with extension of the lower extremities and the degree of displacement ranged from 1 to 4 (mean 2.7) vertebral levels. Because this movement might cause migration into veins that connect to the inferior vena cava, the catheter tip should be located between T9 and L3, except at the renal vein junction. Percutaneous central venous catheterization via the great saphenous vein is safe and useful. Regression equations provided for rapid estimation of the optimal length of insertion.  相似文献   
78.
The role of food-specific antibodies in the pathogenesis of food allergy is controversial. The first step in solving this controversy may be the assessment of antibody response to food antigens in the normal population. Most of the existing data in this field come from studies that used assays of different standards. This study investigated food-specific antibodies in the normal population using standardized assays. Normal levels of antibody titers were also derived for use as reference. Two hundred and eight individuals from different age groups participated. Immunoglobulin G (IgG) antibodies to cow's milk and its component proteins, and to hen's egg ovalbumin, IgA and IgM antibodies to β-lactoglobulin and ovalbumin were measured by enzyme-linked immunosorbent assay. The sepharose-radioallergosorbent test was used to measure IgE antibodies to cow's milk and ovalbumin. Titers of IgG antibodies to cow's milk and its component proteins revealed an age-related trend, peaking in the 5 months-1 year age group and then decreased to negligible values in adults. A similar trend was observed with IgG anti-ovalbumin antibodies. Temporal association was less evident for antibodies of other classes. Only six subjects had positive IgE antibodies to cow's milk, while none had positive IgE anti-ovalbumin antibody. The prevalences of IgG antibodies to cow's milk, its component proteins, and ovalbumin are influenced by age and feeding habits. Cross-reactivity to related food antigens is common. The presence of IgE antibodies to food antigens is not a physiological phenomenon.  相似文献   
79.
We report on a patient with cyclic neutropenia who was treated by granulocyte colony-stimulating factor (G-CSF) and high-dose immunoglobulin. The serial examination revealed cyclic fluctuations in the numbers of neutrophils, monocytes, platelets in peripheral blood, and in the serum G-CSF concentration. Bone marrow examination confirmed a cyclic fluctuation of both progenitor cells (CFU-GM) and CD10-positive B cells. The therapy of G-CSF followed by high-dose immunoglobulin achieved a disappearance of neutrophil oscillations. It suggested that the combination therapy of G-CSF with high-dose immunoglobulin might be effective for cyclic neutropenia.  相似文献   
80.
A 9 year old boy with acute lymphoblastic leukemia (ALL) received recombinant human granulocyte colony-stimulating factor (rhG-CSF) and showed a marked increment of myeloblasts in the peripheral blood. He was administered repeated courses of intermediate-dose cytosine arabinoside (Ara-C) therapy (1500 mg/m2, days 1–5) for frequent central nervous system (CNS) relapse of ALL. The peripheral white blood cell nadir was less than 1000/μL, so he was treated with rhG-CSF. A marked increment of peripheral blood blasts was noted 3–5 days after rhG-CSF treatment. These cells decreased with the appearance of mature myeloid cells and disappeared about 2 weeks after the start of treatment. These findings suggested that the blasts might have the ability to differentiate into mature myeloid cells. A control patient with repeated CNS relapse of ALL showed no increment of peripheral blood blasts after similar repeated courses of Ara-C without rhG-CSF treatment. Cultured peripheral blood blasts obtained from the present patient showed differentiation into mature myeloid cells by morphological studies and surface marker analysis. These findings indicate that the peripheral blood blasts drawn by G-CSF were not leukemic blasts but normal myeloblasts.  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