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   524篇
  免费   28篇
  国内免费   2篇
耳鼻咽喉   7篇
儿科学   17篇
妇产科学   7篇
基础医学   78篇
口腔科学   8篇
临床医学   55篇
内科学   87篇
皮肤病学   38篇
神经病学   44篇
特种医学   24篇
外科学   61篇
综合类   6篇
一般理论   1篇
预防医学   35篇
眼科学   22篇
药学   36篇
中国医学   1篇
肿瘤学   27篇
  2023年   7篇
  2022年   24篇
  2021年   40篇
  2020年   20篇
  2019年   31篇
  2018年   28篇
  2017年   21篇
  2016年   19篇
  2015年   12篇
  2014年   23篇
  2013年   22篇
  2012年   39篇
  2011年   46篇
  2010年   20篇
  2009年   16篇
  2008年   21篇
  2007年   25篇
  2006年   17篇
  2005年   14篇
  2004年   13篇
  2003年   12篇
  2002年   9篇
  2001年   7篇
  2000年   9篇
  1999年   5篇
  1996年   2篇
  1993年   1篇
  1991年   2篇
  1990年   3篇
  1989年   1篇
  1988年   4篇
  1987年   1篇
  1986年   1篇
  1985年   4篇
  1984年   2篇
  1983年   2篇
  1982年   1篇
  1981年   2篇
  1977年   1篇
  1975年   1篇
  1974年   2篇
  1973年   3篇
  1972年   2篇
  1971年   1篇
  1970年   2篇
  1969年   2篇
  1968年   3篇
  1967年   6篇
  1966年   1篇
  1936年   1篇
排序方式: 共有554条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
Despite recent advances made in its treatment, multiple myeloma (MM) remains an incurable B cell malignancy. Thus, the objective for treating these patients is to prolong overall survival (OS) and preserve patients’ quality of life. We have analyzed data from 264 consecutive MM patients who had their initial visit between July 1, 2004 and December 1, 2014 and have received treatment in a single clinic specializing in MM. We determined their progression-free survival (PFS, OS, and 5-year OS). The PFS for frontline (n = 165 treatments), salvage (n = 980), and all treatments (n = 1145) were 13.9, 4.6, and 5.5 months, respectively. The median OS of all patients was 98 months with a 5-year survival of 74%. The results of this study show a marked improvement in OS for unselected MM patients compared with historical data. There were no significant differences in OS between patients with different International Staging System (ISS) stages. Younger patients (<65 years old) showed a longer OS. The results of this study should help physicians predict outcomes for MM patients and be encouraging for patients with this B cell malignancy.  相似文献   
85.
The aircraft cabin and flight deck ventilation are supplied from partially compressed unfiltered bleed air directly from the engine. Worn or defective engine seals can result in the release of engine oil into the cabin air supply. Aircrew and passengers have complained of illness following such “fume events”. Adverse health effects are hypothesized to result from exposure to tricresyl phosphate mixed esters, a chemical added to jet engine oil and hydraulic fluid for its anti-wear properties. Our goal was to develop a laboratory test for exposure to tricresyl phosphate. The assay was based on the fact that the active-site serine of butyrylcholinesterase reacts with the active metabolite of tri-o-cresyl phosphate, cresyl saligenin phosphate, to make a stable phosphorylated adduct with an added mass of 80 Da. No other organophosphorus agent makes this adduct in vivo on butyrylcholinesterase. Blood samples from jet airplane passengers were obtained 24-48 h after completing a flight. Butyrylcholinesterase was partially purified from 25 ml serum or plasma, digested with pepsin, enriched for phosphorylated peptides by binding to titanium oxide, and analyzed by mass spectrometry. Of 12 jet airplane passengers tested, 6 were positive for exposure to tri-o-cresyl phosphate that is, they had detectable amounts of the phosphorylated peptide FGEpSAGAAS. The level of exposure was very low. No more than 0.05 to 3% of plasma butyrylcholinesterase was modified. None of the subjects had toxic symptoms. Four of the positive subjects were retested 3 to 7 months following their last airplane trip and were found to be negative for phosphorylated butyrylcholinesterase. In conclusion, this is the first report of an assay that detects exposure to tri-o-cresyl phosphate in jet airplane travelers.  相似文献   
86.
The short chain fatty acid (SCFA) butyrate, a product of fermentation of dietary fiber in the human colon, is found to exert multiple regulatory processes in colon carcinogenesis. The aim of this study was to find out whether butyrate affects the tumor-promoting genes osteopontin (OPN) and cyclooxygenase (COX)-2, their respective proteins and/or their functional activity in matched normal, adenoma and tumor colon tissues obtained from 20 individuals at colon cancer surgery. Quantitative real-time polymerase chain reaction experiments showed increased levels of OPN and COX-2 messenger RNA in tumor tissues when compared with the adjacent normal samples (P < 0.001). The addition of butyrate reduced OPN and COX-2 mRNA expression in all tissue types compared with the related medium controls (tumor: P < 0.05). In tumor samples, a downregulation of up to median 35% (COX-2) and 50% (OPN) was observed, respectively. Thereby, tumors with lower levels of OPN basal expression were more sensitive to inhibition and vice versa for COX-2 in normal tissue. At the protein and enzyme level, which were determined by using western blot and enzyme immunometric assays, the impact of the SCFA was not clearly visible anymore. The active proteins of OPN and COX-2 (determined by prostaglandin E(2)) were found to correlate with their respective mRNA expression only in 50-63% of analyzed donors. For the first time, our data reveal new insights into the chemoprotective potential of butyrate by showing the suppression of OPN and COX-2 mRNA in primary human colon tissue with the strongest effects observed in tumors.  相似文献   
87.
Insomnia is a costly disorder that affects a significant number of people. In many cases, insomnia is comorbid with other illnesses, which complicates its diagnosis and treatment. Most often it is treated with medication; however, patients are not always safe using hypnotics, and medication does not attack the source of the disorder. Cognitive behavioral therapies are better for long-term treatment because they address factors causing or perpetuating insomnia, as opposed to treatments that focus on symptoms. This article examines various nonpharmacological treatments for insomnia. In addition, because circadian rhythm disorders may exhibit symptoms similar to insomnia, there is also a brief overview of 2 common circadian rhythm disorders, delayed sleep phase syndrome and advanced sleep phase syndrome.  相似文献   
88.
INTRODUCTION: Hair loss is a very common complaint. The diagnosis is based on clinical, dermoscopic and pathological examination. The treatment is usually continuous and requires strong compliance. AREAS COVERED: This article aims to i) summarize current treatment options for the most common forms of hair loss; ii) update the literature on treatment options to emerge over the 3 years since the release of the first edition of this article in 2009; and iii) outline future strategies for treating alopecia. EXPERT OPINION: There is good evidence-based information for the treatment of androgenetic alopecia. There are very few good-quality randomized studies, and no information about long-term results for most of the available treatments for alopecia areata and cicatricial alopecias. Significant research success has been achieved over the past few years through i) discovering the genetic profile of alopecia areata; ii) working on follicular neogenesis in androgenetic alopecia; and iii) discovering the PPAR-γ pathway in scarring alopecia.  相似文献   
89.
We report on a case of a multiple congenital anomalies in a newborn infant whose mother was on allopurinol treatment through the pregnancy. The pattern of congenital anomalies that was noted in our patient was similar to the pattern described in a number of published reports following mycophenolate mofetil [CellCept®] treatment during pregnancy. The anomalies present in our patient include: diaphragmatic hernia, unilateral microtia and absence of external auditory canal, micrognathia, microphthalmia, optic nerve hypoplasia, hypoplasia of the corpus callosum, unilateral renal agenesis, pulmonary agenesis, and cleft lip and palate. Since both allopurinol and mycophenolate mofetil act by disrupting purine biosynthesis and given the similarities in anomalies seen after prenatal exposure, we suggest that allopurinol should also be considered a teratogen. © 2011 Wiley‐Liss, Inc.  相似文献   
90.
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