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   268篇
  免费   12篇
耳鼻咽喉   4篇
儿科学   7篇
妇产科学   25篇
基础医学   45篇
口腔科学   7篇
临床医学   34篇
内科学   41篇
皮肤病学   1篇
神经病学   15篇
特种医学   14篇
外科学   51篇
预防医学   1篇
眼科学   2篇
药学   22篇
肿瘤学   11篇
  2022年   2篇
  2021年   7篇
  2020年   4篇
  2019年   3篇
  2018年   4篇
  2017年   2篇
  2016年   12篇
  2015年   3篇
  2014年   9篇
  2013年   18篇
  2012年   28篇
  2011年   16篇
  2010年   14篇
  2009年   9篇
  2008年   15篇
  2007年   18篇
  2006年   21篇
  2005年   18篇
  2004年   8篇
  2003年   5篇
  2002年   5篇
  2001年   6篇
  2000年   9篇
  1999年   5篇
  1998年   2篇
  1997年   2篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   5篇
  1989年   3篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1984年   2篇
  1980年   1篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1974年   2篇
  1973年   2篇
  1972年   2篇
  1969年   2篇
  1968年   1篇
排序方式: 共有280条查询结果,搜索用时 15 毫秒
161.
162.
Vascular transit time is an important indicator of microcirculatory health. We present a second-order-plus-dead-time (SOPDT) model for robust estimation of kinetic parameters characterizing microvascular bolus passage using two-photon fluorescence microscopy (2PFM) in anesthetized rats receiving somatosensory stimulation. This methodology enables quantification of transit time, time-to-peak, overshoot, and rate of bolus passage through the microvascular network. The overall transit time during stimulation, of 2.2±0.1 seconds, was shorter (P∼0.0008) than that at rest (2.7±0.2 seconds). When compared with conventional γ-variate modeling, the SOPDT modeling yielded better quality of fit both at rest (P<0.0001) and on activation (P<0.001).  相似文献   
163.
Malignant fibrous histiocytoma (MFH) is the most common soft-tissue sarcoma of late adult life occurring predominantly in the extremities and the retroperitoneum. MFH of the ovary is very rare, with only six cases previously reported. A 67-year-old woman with a right pelvic tumor highly suspicious of ovarian carcinoma was submitted to exploratory laparotomy. Total abdominal hysterectomy, bilateral salpingo-oophorectomy, total omentectomy, pelvic and paraaortic lymphadenectomy with right hemicolectomy along with permanent cutaneous ileostomy were performed. Since a storiform-pleomorphic type of MHF was diagnosed from histopathological and immunohistochemical findings, chemotherapy was proposed as the postoperative treatment. Despite extensive surgery with negative surgical margins, the patient had recurrence of the tumor within four months, and was submitted to secondary surgery. A combination of chemo- and radiotherapy was performed postoperatively, but the patient developed respiratory problems and died one year later from the primary diagnosis.  相似文献   
164.
Cell therapy holds promise for tissue regeneration, including in individuals with advanced heart failure. However, treatment of heart disease with bone marrow cells and skeletal muscle progenitors has had only marginal positive benefits in clinical trials, perhaps because adult stem cells have limited plasticity. The identification, among human pluripotent stem cells, of early cardiovascular cell progenitors required for the development of the first cardiac lineage would shed light on human cardiogenesis and might pave the way for cell therapy for cardiac degenerative diseases. Here, we report the isolation of an early population of cardiovascular progenitors, characterized by expression of OCT4, stage-specific embryonic antigen 1 (SSEA-1), and mesoderm posterior 1 (MESP1), derived from human pluripotent stem cells treated with the cardiogenic morphogen BMP2. This progenitor population was multipotential and able to generate cardiomyocytes as well as smooth muscle and endothelial cells. When transplanted into the infarcted myocardium of immunosuppressed nonhuman primates, an SSEA-1+ progenitor population derived from Rhesus embryonic stem cells differentiated into ventricular myocytes and reconstituted 20% of the scar tissue. Notably, primates transplanted with an unpurified population of cardiac-committed cells, which included SSEA-1 cells, developed teratomas in the scar tissue, whereas those transplanted with purified SSEA-1+ cells did not. We therefore believe that the SSEA-1+ progenitors that we have described here have the potential to be used in cardiac regenerative medicine.  相似文献   
165.
There is a high incidence of upper urothelial carcinoma (UUC) in regions affected by Balkan Endemic Nephropathy (BEN). The aim of this study was to compare E-cadherin expression in UUC, in regions affected by BEN, and in control rural and city populations free of BEN. Another aim was to determine the influence of some morphological parameters on the E-cadherin status. In the samples of 85 UUC patients, of whom 40 lived in BEN settlements and 45 served as control subjects, immunoreactions were performed using monoclonal anti-human E-cadherin antibody. Aberrant expression of E-cadherin was more frequent in BEN tumors than in control tumors (p<0.01). Decreased E-cadherin expression was linked to high grade and solid growth in control and BEN tumors (p<0.0001 and <0.05 versus p<0.05 and <0.05, respectively), and to the stage in control tumors (p<0.01). However, BEN low grade and low stage tumors showed aberrant expression more often than did control tumors (p<0.05 and <0.005, respectively). In control tumors, using univariate analysis, E-cadherin status was found to be influenced by grade, stage, and tumor growth (p=0.001, 0.017, 0.015, respectively). In the same group, only the grade was significant according to multistep logistic regression analysis (Wald=6.429 and p=0.011). The growth pattern had a predominant influence on E-cadherin expression in BEN tumors (p=0.005). A significant influence on normal membranous or abnormal cytoplasmic expression of E-cadherin in UUC is exerted by tumor grade, stage, growth, and metaplastic change (p=0.002, 0.048, 0.019, 0.011, respectively), but only by tumor grade in the multistep logistic regression model. These results suggest that decreased expression of E-cadherin in BEN tumors may be linked to tumor growth, while expression of E-cadherin in control tumors may be associated with tumor grade.  相似文献   
166.
Vaginal melanomas account for fewer than 2% of vaginal malignancies. The mean age at diagnosis is 55 years and the prognosis is poor, with an overall 5-year survival rate of 5% to 10%.  相似文献   
167.
At the Institute of Gynecology and Obstetrics over a period of five years, more than 180,000 women were examined; 580 simple and 178 radical vulvectomies were performed.  相似文献   
168.
169.

Purpose

To assess the value of the routine use of radiochromic films in abdominopelvic embolization procedures to improve patient follow-up.

Methods

A total of 55 patients who underwent transcatheter abdominopelvic embolization were prospectively included. Six types of procedures were evaluated including hepatic chemoembolization (HCE), gonadal veins embolization (GVE), uterine elective embolization (UEE), uterine urgent embolization (UUE), abdominal elective embolization (AEE), and abdominal urgent embolization (AUE). Dosimetric indicators (DIs) such as air-kerma (AK) and kerma-area-product (KAP) were collected and peak skin dose (PSD) was measured with radiochromic films. Correlations between PSD and DIs were searched for.

Results

The mean (±standard deviation [SD]) PSD for the various procedures were: 1033 ± 502 mGy for HCE; 476 ± 271 mGy for GVE; 460 ± 171 mGy for UEE; 531 ± 263 mGy for UUE; 708 ± 896 mGy for AEE; 683 ± 392 mGy for AUE. Strong correlations were observed between PSD and DIs (r = 0.974 for AK and r = 0.925 for KAP). PSD was > 2 Gy in one procedure and all procedures (7/132) procedures resulted in AK > 2 Gy, mostly for HCE and AEE.

Conclusion

Dosimetry using radiochromic film is only appropriate for HCE, AEE and AUE, whereas dose-mapping systems present a more suitable solution for all embolizations including those with AK that occasionally exceed 2 Gy.  相似文献   
170.
Methicillin-resistant Staphylococcus epidermidis (MRS) predominantly colonizes the skin and mucous membranes of humans and other animals. We describe the case of a male newborn of gestational age 39 weeks whose primary and repeated blood cultures and cerebrospinal fluid samples isolated MRS. The choice and duration of antibiotic therapy were determined by the clinical presentation, infection parameters, and results of bacteriological analyses of blood and cerebrospinal fluid samples obtained from the newborn on the day 5 of life. After 28 days of antibiotic therapy for sepsis accompanied by meningitis, the newborn was discharged home without sequelae.  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