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   238篇
  免费   10篇
  国内免费   6篇
儿科学   8篇
妇产科学   6篇
基础医学   13篇
口腔科学   13篇
临床医学   41篇
内科学   49篇
皮肤病学   11篇
神经病学   1篇
特种医学   44篇
外科学   17篇
综合类   23篇
预防医学   9篇
眼科学   3篇
药学   10篇
肿瘤学   6篇
  2021年   2篇
  2020年   4篇
  2018年   4篇
  2017年   2篇
  2016年   2篇
  2015年   5篇
  2014年   10篇
  2013年   11篇
  2012年   7篇
  2011年   8篇
  2010年   20篇
  2009年   14篇
  2008年   9篇
  2007年   15篇
  2006年   7篇
  2005年   3篇
  2004年   6篇
  2003年   2篇
  2002年   3篇
  2001年   2篇
  2000年   6篇
  1999年   6篇
  1998年   15篇
  1997年   8篇
  1996年   11篇
  1995年   9篇
  1994年   10篇
  1993年   3篇
  1992年   2篇
  1991年   2篇
  1990年   2篇
  1989年   1篇
  1988年   5篇
  1987年   3篇
  1986年   5篇
  1985年   3篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1980年   2篇
  1978年   1篇
  1977年   3篇
  1976年   2篇
  1972年   1篇
  1971年   1篇
  1970年   1篇
  1968年   5篇
  1967年   1篇
  1928年   1篇
排序方式: 共有254条查询结果,搜索用时 10 毫秒
81.
82.
Background We describe different possible enhancement patterns in liver hemangiomas with atypical appearance on baseline ultrasound after microbubble-based contrast agent injection. Methods From a series of 253 consecutive lesions that were indeterminate on baseline ultrasound and then scanned after injection of air-filled microbubble contrast agent, 65 focal liver lesions were retrospectively selected on the basis of a diagnosis of liver hemangioma on multiphase contrast-enhanced computed tomography (n = 23), magnetic resonance imaging (n = 27), or histology (n = 15). Each lesion was scanned during arterial phase (30 s after microbubble injection) and late phase (5 min after injection). On-site sonologists performed retrospective assessment of contrast-enhancement patterns by consensus. Results Centripetal fill-in preceded (n = 50) or not preceded (n = 3) by peripheral nodular/rim-like enhancement was the prevalently observed contrast-enhancement pattern, equivalent to the typical enhancement pattern of liver hemangiomas on contrast-enhanced computed tomography or magnetic resonance imaging. In the remaining lesions, additional enhancement patterns (diffuse contrast enhancement with rapid fill-in and a late hyper-isoechoic appearance, n = 6; peripheral nodular enhancement with a late hypoechoic appearance, n = 3; or persistent heterogeneous and hyperechoic appearance, n = 3) were observed. Conclusion Different contrast-enhancement patterns are possible in atypical liver hemangiomas after microbubble injection. Typical centripetal fill-in is the prevalent pattern and its evidence allows diagnosis.  相似文献   
83.
目的:观察正常人近端肾小管上皮细胞(HK2)是否表达黏附分子CD146,初步探讨CD146与肾小管上皮细胞的关系及其生理意义。方法:实验于2005-05/2006-02在上海交通大学医学院临床检验系实验室完成。①实验材料:人近端肾小管上皮细胞株(HK2,由中国科学院上海生物化学与细胞生物学研究所惠赠)。②实验干预:体外培养的HK2连续观察72h。③实验评估:采用倒置显微镜、光学显微镜下观察肾小管上皮细胞的形态;用反转录-聚合酶链反应方法检测CD146 mRNA的表达;流式细胞仪和免疫荧光法测定CD146蛋白质的表达及其定位;进一步在培养细胞的上清液中检测CD146的可溶性形式(sCD146)。结果:①肾小管上皮细胞的形态学观察和鉴定:传代培养的HK2三四天融合后呈铺路石样铺于培养瓶底,相关抗原检测抗人keratin阳性,抗Ⅷ因子相关抗原阴性。②CD146 mRNA水平的表达:HK2在培养早期(24h)即表达CD146 mRNA(0.092±0.012),但延长细胞的培养时间似乎并没有进一步改变CD146 mRNA的表达水平(0.097±0.005,0.113±0.015,P>0.05)。③CD146蛋白质水平的表达和定位:CD146不仅位于肾小管上皮细胞膜上,而且在细胞核和胞浆中也有表达。体外培养的HK2相互融合时,位于细胞膜上的CD146表达增强,呈线性、持续性地表达于细胞-细胞间的连接部位,同时胞内的CD146标记也相应增强。④细胞上清液中sCD146的检测:HK2上清液中存在CD146的可溶性形式(sCD146)。培养细胞观察24~72h,sCD146水平在48h升高[(18.00±0.80)μg/L],到72h达到高峰[(29.33±1.22)μg/L],与24h[(13.87±0.46)μg/L]比较,差异均有显著性意义(P<0.05)。结论:人近端肾小管上皮细胞组成性地表达CD146,是肾小管上皮细胞新的生物学标志;CD146在细胞内外的表达强度有赖于细胞间联系的建立和细胞增殖的程度,CD146在促进细胞生长和维持组织完整性等方面发挥重要作用。肾小管上皮细胞上清液中存在CD146的可溶性形式,sCD146在一定程度上也反映了细胞的生长和增殖状况。  相似文献   
84.
BACKGROUND: Slow flow or no reflow phenomenon is increasingly being recognized as a serious problem during coronary angioplasty and stenting. This phenomenon is seen more often during angioplasty in highly thrombogenic milieux, especially in a setting of acute myocardial infarction. The treatment of this complication is often not satisfactory. efficacy of abciximab, a potent antiplatelet drug, in treating slow flow or no reflow phenomenon during primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI). METHODS: Twenty-one instances of persistent slow flow phenomenon were encountered in 131 consecutive patients subjected to primary PTCA for AMI (16%). It was more common in patients presenting with AMI complicated by cardiogenic shock (nine of 21, 43%). Of these 21 cases of slow flow, 10 patients were given injection abciximab during the procedure of primary PTCA as a bail-out measure after encountering the complication of slow flow or no reflow. A predischarge coronary angiography was carried out in all patients who survived. RESULTS: In seven of 10 patients in the abciximab group flow had improved to TIMI-3. In contrast, in the non-abciximab group TIMI flow improved in only four of 11 patients. Patients with persistent slow In this study the authors assessed the flow had significantly higher mortality at the first 30-day follow-up than patients with TIMI-3 flow (33% versus 1.8%, p<0.001). CONCLUSION: In this small nonrandomized study significant improvement in coronary flow was achieved by using intravenous abciximab after observing slow flow or no reflow phenomenon during primary PTCA. More frequent use of this drug in this milieu might help in preventing the development of this complication. Larger studies are warranted to confirm this life-saving beneficial effect of bail-out administration of abciximab during primary angioplasty. (Int J Cardiovasc Intervent 2000; 3:35–39)  相似文献   
85.
We have previously reported that Morinda citrifolia (noni) puree modulates neonatal calves developmental maturation of the innate and adaptive immune system. In this study, the effect of noni puree on respiratory and gastrointestinal (GI), health in preweaned dairy calves on a farm with endemic salmonellosis was examined. Two clinical trials were conducted whereby each trial evaluated one processing technique of noni puree. Trials 1 and 2 tested noni versions A and B, respectively. Puree analysis and trial methods were identical to each other, with the calf as the experimental unit. Calves were designated to 1 of 3 treatment groups in each trial and received either: 0, 15 or 30 mL every 12 hr of noni supplement for the first 3 weeks of life. Health scores, weaning age, weight gain from admission to weaning, and weaned by 6 weeks, were used as clinical endpoints for statistical analysis. In trial 1, calves supplemented with 15 mL noni puree of version A every 12 hr had a higher probability of being weaned by 6 weeks of age than control calves (P = 0.04). In trial 2, calves receiving 30 mL of version B every 12 hr had a 54.5% reduction in total medical treatments by 42 days of age when compared to controls (P = 0.02). There was a trend in reduced respiratory (61%), and GI (52%) medical treatments per calf when compared to controls (P = 0.06 and 0.08, respectively). There were no differences in weight gain or mortality for any treatment group in either trial.  相似文献   
86.
Objective  To compare the assessment of endometrial maturation parameters in endometrial secretion samples obtained by a novel minimally invasive technique with those assessed in tissue biopsies.
Design  Prospective study.
Setting  University Hospital.
Population  Healthy female volunteers attending a gynaecological outpatient clinic.
Methods  Endometrial secretion fluid and tissue sampling 5 days after a spontaneous ovulation assessed with ultrasound.
Main outcome measures  Progesterone (P) receptor, Ki-67 expression and the Noyes criteria were used to date endometrial biopsies. In the endometrial fluid samples, glycodelin A (GdA), leukaemia inhibitory factor (LIF) and P levels were analysed, and protein content and electrophoresis patterns were determined.
Results  All data were correlated to estradiol (E2) and P serum concentrations. The dating according to histology and immunohistochemical staining patterns correlated significantly with GdA levels ( r = 0.376, P = 0.048) in endometrial fluid samples as well with serum levels of E2 ( r = 0.568, P = 0.001) and P ( r = 0.408, P = 0.023). No correlation was observed between tissue dating and LIF levels and protein content in endometrial fluid samples.
Conclusions  The measurement of GdA in endometrial secretion samples may provide a less invasive method for assessing endometrial maturation in potential conception cycles without disrupting implantation.  相似文献   
87.
Objective  To quantify participants' experiences of obtaining and giving information about disorders of sex development (DSD).
Design  Cross-sectional survey study that asked people about their current and past experiences relating to DSD disclosure.
Setting  A large tertiary referral centre for DSD management in the UK.
Population  One hundred of 126 people with a confirmed diagnosis of DSD who were invited to participate in the study formed the usable sample.
Methods  All people who attended clinic for follow-up during the study period and members of a patient support group whose annual meeting fell within the study period were asked to complete the Middlesex Communication Survey.
Main outcome measures  The Middlesex Communication Survey.
Results  Younger participants were more likely to report having been appropriately informed about their diagnosis than older people. Nearly half of the former had been fully informed about their diagnosis by age 15 years, compared with 0% of the older age group. In terms of information sharing, mothers were most likely to be the person with whom the participant had shared (almost/all) DSD information (74%), followed by current partners (71%). Information relating to genital surgery, presence of testes and clitoral anomalies were the least likely aspects to have been unambiguously shared with even the most informed person.
Conclusions  Our results suggest that difficulties in obtaining DSD information from care providers were common, and that communication has improved for younger participants. The study also confirmed that many people with DSD continue to struggle with confiding, even in those closest to them, about aspects of their diagnosis. Care protocol needs to centralise psychological adaptation, which should also be a primary focus for future research.  相似文献   
88.
89.
Almaguer‐Mederosa LE, Falcón NS, Almira YR, Zaldivar YG, Almarales DC, Góngora EM, Herrera MP, Batallán KE, Armiñán RR, Manresa MV, Cruz GS, Laffita‐Mesa J, Cyuz TM, Chang V, Auburger G, Gispert S, Pérez LV. Estimation of the age at onset in spinocerebellar ataxia type 2 Cuban patients by survival analysis. Previous studies have investigated the close association that exists between CAG repeat number and the age at onset in SCA2 = spinocerebellar ataxia type 2. These studies have focused on affected individuals. To further characterize this association and estimate the risk of a carrier developing SCA2 at a particular age as a function of a specific CAG repeat size, we have analyzed a large group of 924 individuals, including 394 presymptomatic and 530 affected individuals with a CAG repeat length of 32–79 units. Using a Kaplan–Meier survival analysis, we obtained cumulative probability curves for disease manifestation at a particular age for each CAG repeat length in the 34–45 range. These curves were significantly different (p < 0.001) and showed small overlap. All these information may be very valuable in predictive‐testing programs, in the planning of studies for the identification of other genetic and environmental factors as modifiers of age at onset, and in the design of clinical trials for people at enlarged risk for SCA2.  相似文献   
90.
Although the incidence of laryngeal tuberculosis has been declining over the past 30 years, it should still be considered in the differential diagnosis of patients with laryngeal pathology. In contrast to the pre-chemotherapy era, few, if any, signs of pulmonary tuberculosis are seen in such cases, and presentation is similar to either chronic non-specific laryngitis or carcinoma. The subglottis is a site rarely involved in laryngeal tuberculosis. Tissue biopsy and culture are diagnostic and a full course of antituberculous chemotherapy usually resolves the condition. Airway insufficiency due to fibrosis, however, often necessitates surgical Intervention. We present a case where the only laryngeal manifestation of tuberculosis was subglottic stenosis.  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