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   3138篇
  免费   217篇
  国内免费   12篇
耳鼻咽喉   14篇
儿科学   117篇
妇产科学   134篇
基础医学   560篇
口腔科学   6篇
临床医学   182篇
内科学   596篇
皮肤病学   98篇
神经病学   146篇
特种医学   98篇
外科学   330篇
综合类   142篇
一般理论   2篇
预防医学   262篇
眼科学   122篇
药学   335篇
中国医学   39篇
肿瘤学   184篇
  2022年   41篇
  2021年   56篇
  2020年   25篇
  2019年   46篇
  2018年   56篇
  2017年   32篇
  2016年   51篇
  2015年   69篇
  2014年   94篇
  2013年   133篇
  2012年   239篇
  2011年   263篇
  2010年   123篇
  2009年   98篇
  2008年   178篇
  2007年   158篇
  2006年   173篇
  2005年   164篇
  2004年   144篇
  2003年   140篇
  2002年   111篇
  2001年   97篇
  2000年   95篇
  1999年   74篇
  1998年   49篇
  1997年   26篇
  1996年   20篇
  1995年   23篇
  1994年   28篇
  1993年   23篇
  1992年   57篇
  1991年   47篇
  1990年   37篇
  1989年   38篇
  1988年   29篇
  1987年   30篇
  1986年   35篇
  1985年   30篇
  1984年   22篇
  1983年   17篇
  1982年   11篇
  1979年   12篇
  1978年   15篇
  1977年   13篇
  1976年   11篇
  1975年   11篇
  1974年   11篇
  1973年   15篇
  1972年   11篇
  1968年   12篇
排序方式: 共有3367条查询结果,搜索用时 16 毫秒
41.
Localizing the sites of infection in the body is possible in nuclear medicine using a variety of radiopharmaceuticals that target different components of the infective and inflammatory cascade. Gamma(γ)-emitting agents such as [67Ga]gallium citrate were among the first tracers used, followed by development of positron-emitting tracers like 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG). Though these tracers are quite sensitive, they have limited specificity for infection due to their concentration in sites of non-infective inflammation. White blood cells (WBC) labelled with γ or positron emitters have higher accuracy for differentiating the infective processes from the non-infective conditions that may show positivity with tracers such as 18F-FDG. We present a pictorial review of potential clinical applications of PET/CT using 18F-FDG labelled WBC.  相似文献   
42.
A preliminary comparative measurement between particle imaging velocimetry (PIV) and laser speckle contrast analysis (LASCA) to study pulsatile flow using ventricular assist device in a patient-specific carotid artery phantom is reported. These full-field optical techniques have both been used to study flow and extract complementary parameters. We use the high spatial resolution of PIV to generate a full velocity map of the flow field and the high temporal resolution of LASCA to extract the detailed frequency spectrum of the fluid pulses. Using this combination of techniques a complete study of complex pulsatile flow in an intricate flow network can be studied.OCIS codes: (100.0100) Image processing, (170.0170) Medical optics and biotechnology, (230.0230) Optical devices, (290.0290) Scattering  相似文献   
43.
44.
45.
46.
Context: Talactoferrin alfa (TLF) is a unique recombinant form of human lactoferrin. The hypothesized mechanism of action involves TLF binding to the intestinal endothelium inducing dendritic cell maturation and cytokine release leading to infiltration of tumor with monocytes and T-lymphocytes and inhibition of tumor growth.

Objective: Based on promising phase II trial results, this correlative study was undertaken to examine immune mechanism of action of TLF in metastatic non-small cell lung cancer (NSCLC) patients.

Methods: Talactoferrin was administered orally at 1.5?g bid weeks 1–12 with 2 weeks off on a 14-week cycle. Enrolled patients had a pathologic diagnosis of NSCLC previously treated with at least two lines of systemic treatment. Patients had core biopsy of tumor before initiation of talactoferrin and at week 7 on TLF. Flow cytometry and quantitative immunohistochemistry for immune correlates were performed on the biopsied specimens.

Results: Four patients with metastatic NSCLC were enrolled. The trial was halted pre-maturely in light of negative phase III trial results. For the two patients who had repeat on-treatment tumor biopsies, a consistent increase in monocytes as a percentage of total immune cells was observed. Otherwise, no clear trend of increase or decrease was observed in any other immune cell parameters compared to matched patient pre-treatment biopsies.

Conclusion: Repeat biopsies for immune correlates by flow cytometry and quantitative immunohistochemistry in NSCLC patients are feasible. In the few patients sampled before trial closure, increased monocytes as a total percentage of the immune cell population within tumor was observed in response to TLF.  相似文献   
47.
48.
49.
A synchronized dyshomeostasis of extra- and intracellular Ca(2+), expressed as plasma ionized hypocalcemia and excessive intracellular Ca(2+) accumulation, respectively, represents a common pathophysiologic scenario that accompanies several diverse disorders. These include low-renin and salt-sensitive hypertension, primary aldosteronism and hyperparathyroidism, congestive heart failure, acute and chronic hyperadrenergic stressor states, high dietary Na(+), and low dietary Ca(2+) with hypovitaminosis D. Homeostatic responses are invoked to restore normal extracellular [Ca(2+)](o), including increased plasma levels of parathyroid hormone and 1,25(OH)(2)D(3). However, in cardiomyocytes these calcitropic hormones concurrently promote cytosolic free [Ca(2+)](i) and mitochondrial [Ca(2+)](m) overloading. The latter sets into motion organellar-based oxidative stress, in which the rate of reactive oxygen species generation overwhelms their detoxification by endogenous antioxidant defenses, including those related to intrinsically coupled increments in intracellular Zn(2+). In turn, the opening potential of the mitochondrial permeability transition pore increases, allowing for osmotic swelling and ensuing organellar degeneration. Collectively, these pathophysiologic events represent the major components to a mitochondriocentric signal-transducer-effector pathway to cardiomyocyte necrosis. From necrotic cells, there follows a spillage of intracellular contents, including troponins, and a subsequent wound healing response with reparative fibrosis or scarring. Taken together, the loss of terminally differentiated cardiomyocytes from this postmitotic organ and the ensuing replacement fibrosis each contribute to the adverse structural remodeling of myocardium and progressive nature of heart failure. In conclusion, hormone-induced ionized hypocalcemia and intracellular Ca(2+) overloading comprise a pathophysiologic cascade common to diverse disorders and that initiates a mitochondriocentric pathway to nonischemic cardiomyocyte necrosis.  相似文献   
50.
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