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   263篇
  免费   5篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   23篇
妇产科学   1篇
基础医学   20篇
口腔科学   1篇
临床医学   22篇
内科学   86篇
皮肤病学   4篇
神经病学   14篇
特种医学   4篇
外科学   41篇
综合类   4篇
预防医学   9篇
眼科学   2篇
药学   27篇
中国医学   1篇
肿瘤学   9篇
  2023年   3篇
  2021年   6篇
  2020年   5篇
  2019年   2篇
  2018年   8篇
  2016年   4篇
  2015年   6篇
  2014年   3篇
  2013年   4篇
  2012年   7篇
  2011年   10篇
  2010年   4篇
  2009年   9篇
  2008年   7篇
  2007年   10篇
  2006年   8篇
  2005年   8篇
  2004年   9篇
  2003年   6篇
  2002年   4篇
  2001年   5篇
  2000年   3篇
  1999年   5篇
  1996年   2篇
  1995年   2篇
  1994年   5篇
  1993年   5篇
  1992年   16篇
  1991年   9篇
  1990年   6篇
  1989年   13篇
  1988年   6篇
  1987年   5篇
  1986年   4篇
  1985年   8篇
  1984年   3篇
  1983年   4篇
  1982年   3篇
  1979年   1篇
  1978年   4篇
  1977年   8篇
  1975年   3篇
  1974年   3篇
  1972年   5篇
  1971年   5篇
  1970年   2篇
  1969年   3篇
  1968年   1篇
  1967年   1篇
  1965年   2篇
排序方式: 共有269条查询结果,搜索用时 15 毫秒
101.
102.
BACKGROUND: Angiogenesis is essential for tumor growth and metastasis. Vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP)/platelet-derived endothelial cell growth factor (PD-ECGF) are involved in increased angiogenic activity and disease progression in solid tumors. However, there is no information regarding the association of these angiogenic factors with clinicopathologic findings in testicular germ cell tumors (GCTs). METHODS: The authors examined the expression of VEGF and TP as well as microvessel density in GCTs and their association with clinicopathologic findings. Expression of VEGF and TP and microvessel density were examined immunohistochemically in 80 GCTs, including 33 seminomas (25 tumors with organ-confined disease and 8 with metastasis) and 47 nonseminomatous testicular GCTs (NSGCTs) (20 tumors with organ-confined disease and 27 with metastasis). Expression of VEGF also was examined in four GCTs and one nonneoplastic testis by immunoblotting. RESULTS: VEGF protein was expressed more highly in GCTs compared with nonneoplastic testes. VEGF expression in GCTs was correlated significantly with microvessel count (P < 0.001). Both VEGF expression and microvessel count were correlated with metastasis in seminoma (P = 0.008 and P < 0.001, respectively), but only VEGF expression was identified as statistically significant by multiple regression analysis (P = 0.006). Conversely, four variables (VEGF expression, microvessel count, the presence of venous invasion, and the presence of embryonal carcinoma elements in the primary tumor) were correlated with metastasis in NSGCT (P < 0.001, P < 0.001, P = 0.004, and P = 0.029, respectively). However, multiple regression analysis revealed that only VEGF expression and microvessel count were significant factors for metastasis (P < 0.007 and P < 0.001, respectively). In contrast, high levels of TP were observed in infiltrating cells, but not in the majority of cancer cells. CONCLUSIONS: The findings of the current study suggest that VEGF expression is involved in tumor development, angiogenesis, and metastasis in GCT.  相似文献   
103.
104.
Hyaluronic acid synthetase (HAS) activity of lyophilized skin from a 49-year-old Japanese man with lichen myxedematosus was assayed. The HAS activity was very high in both diseased and normal appearing skin.  相似文献   
105.
Sixteen patients with the malignant mediastinal tumors compromising the superior vena cava (SVC) and brachiocephalic veins (BCV) were treated from April 1974 to March 1987. SVC reconstruction by prosthesis combined with or without tumor resection were performed in 6 cases and removal of the tumor with partial resection of SVC and right BCV in one case. Two patients died within one month and two patients survived over 5 years postoperatively. Tumor resection, removal of the right lung and SVC wall, and patch angioplasty were performed in one patient who died three and one half months postoperatively. Resection of the tumor and left BCV were performed in 4 patients. Segmentally resected left BCV was reconstructed with interposed graft in two, prosthesis was implanted between left BCV and right atrium in one and no venous reconstruction was attempted in one. Three patients are alive and one patient died six and one half years after operation. Exploratory mediastinotomy was carried out in 3 cases and radiation therapy alone in one case. All but one patients died within one year after diagnosis. Though the long term results of the surgical treatment for malignant mediastinal tumor was not satisfactory, extensive resection of the tumor was worth attempting, as the patency rate of the prosthetic venous reconstruction was improved.  相似文献   
106.
Katafuchi T  Duan S  Take S  Yoshimura M 《Brain research》2005,1037(1-2):180-186
The preoptic/anterior hypothalamus (POA) is one of the major brain regions where cytokines and their related mediators (i.e., prostaglandins) exert diverse actions. In the present study, the modulatory effects of prostaglandin E(2) (PGE(2)) on the glutamate-induced membrane currents were examined using perforated-patch clamp method in rat POA neurons that had been mechanically dissociated by vibration without enzyme treatment. Application of glutamate through U-tube induced a slow outward current following fast inward ionotroic current at a holding membrane potential of -30 mV. The slow outward current was also induced by N-methyl-d-aspartate (NMDA), accompanied by an increased membrane conductance, and inhibited by perfusion with Ca(2+)-free solution, tetraethylammonium chloride (TEA), and apamin, suggesting a Ca(2+)-dependent K(+) current (KCa) activated by Ca(2+) entry through NMDA channels. Perfusion with PGE(2) at 0.1-10 microM, a principal mediator of fever and neuroendocrine control at the POA, did not produce apparent current by itself, but selectively potentiated the glutamate- or NMDA-induced KCa without affecting inward currents. The KCa induced by activation of NMDA receptors may serve as a feedback mechanism and the modulatory effects of PGE(2) on the KCa may have an important physiological significance.  相似文献   
107.
We present a rare case of a female neonate with an imperforate anus associated with a perineal mass which may correspond to an extrophied rectal duplication. Associated anomalies were thoracic hemivertebrae and a multicystic dysplastic kidney. Excision of the perineal lesion followed by anal transplantation and perineal reconstruction corrected the anomaly.  相似文献   
108.
Aplasia of the dorsal pancreas and choledochal cyst   总被引:2,自引:0,他引:2  
The authors describe a rare case of choledochal cyst and aplasia of the dorsal pancreas complicated with chronic pancreatitis. A 9-year-old boy presented with obstructive jaundice. After biliary drainage using pericutaneous transhepatic gallbladder drainage (PTGBD) technique, the patient underwent choledochal cyst excision with Roux-en-Y hepaticojejunostomy. The association of choledochal cyst and aplasia of the dorsal pancreas with chronic pancreatitis has never been reported previously.  相似文献   
109.
Mutations in the short‐chain enoyl‐CoA hydratase (SCEH) gene, ECHS1, cause a rare autosomal recessive disorder of valine catabolism. Patients usually present with developmental delay, regression, dystonia, feeding difficulties, and abnormal MRI with bilateral basal ganglia involvement. We present clinical, biochemical, molecular, and functional data for four affected patients from two unrelated families of Samoan descent with identical novel compound heterozygous mutations. Family 1 has three affected boys while Family 2 has an affected daughter, all with clinical and MRI findings of Leigh syndrome and intermittent episodes of acidosis and ketosis. WES identified a single heterozygous variant in ECHS1 at position c.832G > A (p.Ala278Thr). However, western blot revealed significantly reduced ECHS1 protein for all affected family members. Decreased SCEH activity in fibroblasts and a mild increase in marker metabolites in urine further supported ECHS1 as the underlying gene defect. Additional investigations at the DNA (aCGH, WGS) and RNA (qPCR, RT‐PCR, RNA‐Seq, RNA‐Array) level identified a silent, common variant at position c.489G > A (p.Pro163=) as the second mutation. This substitution, present at high frequency in the Samoan population, is associated with decreased levels of normally spliced mRNA. To our understanding, this is the first report of a novel, hypomorphic allele c.489G > A (p.Pro163=), associated with SCEH deficiency.  相似文献   
110.
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