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   330篇
  免费   21篇
  国内免费   5篇
儿科学   6篇
妇产科学   2篇
基础医学   34篇
口腔科学   15篇
临床医学   35篇
内科学   57篇
皮肤病学   33篇
神经病学   15篇
特种医学   21篇
外科学   46篇
综合类   27篇
预防医学   17篇
眼科学   1篇
药学   6篇
中国医学   26篇
肿瘤学   15篇
  2024年   1篇
  2023年   4篇
  2022年   13篇
  2021年   23篇
  2020年   13篇
  2019年   11篇
  2018年   10篇
  2017年   7篇
  2016年   10篇
  2015年   8篇
  2014年   18篇
  2013年   29篇
  2012年   11篇
  2011年   16篇
  2010年   14篇
  2009年   12篇
  2008年   18篇
  2007年   17篇
  2006年   10篇
  2005年   11篇
  2004年   8篇
  2003年   6篇
  2002年   4篇
  2001年   6篇
  2000年   4篇
  1999年   6篇
  1998年   5篇
  1997年   12篇
  1996年   6篇
  1995年   3篇
  1994年   1篇
  1993年   4篇
  1992年   2篇
  1991年   6篇
  1990年   4篇
  1988年   2篇
  1987年   1篇
  1986年   4篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1981年   2篇
  1980年   3篇
  1977年   1篇
  1976年   1篇
  1972年   2篇
  1967年   1篇
排序方式: 共有356条查询结果,搜索用时 5 毫秒
1.
AimsLocal coronary and systemic inflammation is pronounced in patients with diabetes mellitus (DM). Intracoronary thermography detects local inflammation and C-reactive protein (CRP) is a marker of systemic inflammation. We investigated whether or not, in patients with DM, thermal heterogeneity of culprit lesions (CLs) correlates with that of non-culprit lesions (NCLs) and with systemic inflammation.MethodsWe included DM patients who had two angiographically significant lesions and were undergoing percutaneous coronary intervention. We measured the temperature difference (ΔT) between the lesion and proximal vessel wall.ResultsWe included 104 (n = 208 lesions) patients: 32 (n = 64 lesions) had DM and 72 (n = 144 lesions) were non-DM (control group). ΔT was increased in DM in both CLs and NCLs (CLs: DM = 0.12 ± 0.06 °C; no DM = 0.06 ± 0.04 °C; P < 0.01 versus NCLs: DM = 0.13 ± 0.08 °C versus no DM = 0.06 ± 0.05 °C; P < 0.01). Patients with DM had similar ΔT in CLs and NCLs (P = 0.49). A linear correlation was detected between heat production in all lesions and CRP (R = 0.45; P < 0.01), which was attributed to the correlation of ΔT in lesions of patients with DM and CRP (R = 0.32; P < 0.01). In lesions of patients with low CRP, a greater rate of discrepancy was found, as 100% of lesions in patients with DM versus 66.1% of lesions of patients without DM had a high ΔT in one or both lesions (P < 0.01).ConclusionIn patients with DM, local inflammatory activation is diffuse and correlates with systemic inflammation. However, low systemic inflammatory activation does not always predict an increase in local thermal heterogeneity.  相似文献   
2.
A new type of disposable external defibrillation electrode has been developed to reduce the skin irritation commonly associated with defibrillation and synchronised cardioversion. This design employs an impedance gradient to reduce the proportion of current delivered to the electrode periphery. The temperature distribution under the new electrode was compared with that of four other types of commercially available electrodes after repeated high-energy biphasic defibrillation discharges to domestic swine. Skin temperature distributions were acquired using non-invasive thermography. Measurements of the maximum temperature rise at each electrode site, taken 3.6s after the fifth defibrillation discharge, demonstrated that the new impedance-gradient electrode produced 50–60% less skin heating than two of the three uniform-impedance electrode designs. Histological examination of erythematous sites excised 24h after defibrillation quantified the associated skin damage using a scoring protocol developed for this study. In contrast to previous studies, histological examinations demonstrated second-degree skin burns following defibrillation. The new electrode design, however, induced 44–46% less skin damage than two of the traditional uniform-impedance electrodes.  相似文献   
3.
A case report is presented of a 15-year-old girl with reflex sympathetic dystrophy (RSD). She was referred to hospital because of left upper limb pain. Her left upper limb was cold, edematous and blue with a limited active range of movement. The serum concentration of noradrenaline was lower on the painful side than on the healthy side, and neurotropin, which has an antinociceptive effect to hyperalgesia, was clearly effective. Early diagnosis and management is essential in the treatment of RSD and administration of neurotropin is a useful and non-invasive treatment without severe adverse effects.  相似文献   
4.
家兔颈后肌受长期应力作用的实验研究   总被引:7,自引:0,他引:7  
目的 建立颈后肌受长期应力作用动物模型并进行相关研究.方法 30只家兔随机分为模型组和对照组,每组15只.模型组家兔置于特制低头位框架中,低头角度为45度,每天1次,每次5小时;对照组除不低头外余条件相同.12周后分别进行颈椎X线、颈后部红外热像图、血清肌酸激酶和乳酸脱氢酶含量以及颈后肌超氧化物歧化酶和丙二醛含量观察.结果 模型组颈椎X线改变积分值实验后明显高于实验前和对照组,差异具有显著性;模型组与对照组颈后部红外热像图有明显差异;模型组血清肌酸激酶、乳酸脱氢酶的含量均明显高于对照组;模型组丙二醛含量明显高于对照组而超氧化物歧化酶含量明显低于对照组.结论 家兔颈后肌受长期应力作用后出现颈部的生物力学和生物化学失衡.  相似文献   
5.
目的 观察重度海水浸泡体温过低症大鼠不同热水浴复温成功率和复温曲线特征。方法 取490只雄性SD大鼠(实验前行温度记录器腹腔置入术),随机分为浸泡组(450只)和对照组(40只),浸泡大鼠在(15.0±0.2)℃海水中分别浸泡不同时长:2 h(100只)、5 h(150只)、10 h(200只),每个浸泡时长的存活大鼠均随机分为5个亚组并给予相应的方法复温:被动复温(被动复温组)、37℃热水浴复温0.5 h(37℃主动复温0.5 h组)、37℃热水浴复温1 h(37℃主动复温1 h组)、42℃热水浴复温0.5 h(42℃主动复温0.5 h组)、42℃热水浴复温1 h(42℃主动复温1 h组);对照组不进行海水浸泡,随机均分为4个亚组,分别给予上述4种不同方法的热水浴复温。计算各组的复温成功率;复温20 h后采集存活大鼠血清检测肌酸激酶同工酶(CK-MB)、丙氨酸转氨酶(ALT)、乳酸脱氢酶(LDH)水平;取出温度记录器读取动态腹腔温度数据,计算被动复温速度、热水浴复温迟发后降效应。结果 随着浸泡时间的延长,浸泡组大鼠低温海水浸泡存活率下降(P<0.05),被动复温组及主动复温组的复温成功率均下降(P<0.05),37℃主动复温1 h组大鼠复温成功率大于或等于其他主动复温组,且大于或等于被动复温组;对照组热水浴后均存活。存活大鼠血清CK-MB、ALT和LDH水平随着浸泡时间延长逐渐升高,主动复温组较对照组均升高(P<0.05),在浸泡时长相同时,37℃主动复温1 h组的CK-MB、ALT和LDH水平低于其他主动复温组,且低于被动复温组,部分差异有统计学意义(P<0.05)。分析复温曲线,被动复温组复温速度随浸泡时间的延长而下降(P<0.05),且死亡大鼠的复温速度低于存活大鼠(P<0.05);热水浴复温大鼠腹腔温度可出现迟发后降效应,迟发后降总效应越大,死亡率越高;对照组37℃热水浴迟发后降效应不明显,42℃热水浴明显(P<0.05)。结论 在重度海水浸泡体温过低症的救治中,恰当的热水浴复温成功率大于被动复温。紧急情况下可以将热水浴作为一种复温选择,但不当的复温条件可降低救治成功率,其可能与迟发后降效应有关。  相似文献   
6.
When the briquetting process of fine-grained material takes place in the roller press unit, the pressure reached is over a hundred megapascals. This parameter is a result, among other factors, of the geometry of a compaction unit and also the properties of the consolidated material. The pressure of the unit is not constant and the changes in value depend on a given place on the molding surface. By the process of generating different types of pressure on the surface of briquettes, their compaction is different as well. The distribution of temperature on the surface of the briquettes may determine the pressure used locally on them. Nevertheless, the distribution of stress in the briquetting material is still a subject of scientific study. However, it is known that the pressure exerted on the briquette is different for different compaction systems. The article includes authors’ further thermography studies on the classical pillow-shaped briquetting process (instead of the saddle-shaped ones that were previously conducted) of four materials (calcium hydroxide and water mixture, mill scale, charcoal fines and starch mixture, as well as a mixture of EAFD, scale, fine coke breeze, molasses, and calcium hydroxide). Immediately after the briquettes left the compaction zone, thermal images were taken of them, as well as forming rollers. Thermograms that were obtained and the variability of temperature at characteristic points of the surface of pillow-shaped briquettes were analyzed. They showed differences in temperature on the surface of briquettes. In all four cases, the highest briquette temperatures were recorded in their upper part, which proves their better densification in this part. The temperature differences between the lower and upper part of the briquettes ranged from 1.8 to 9.7 °C, depending on the mixture.  相似文献   
7.
Background:Musculoskeletal injuries (MSDs) have become a major public health problem worldwide. Current diagnosis techniques for MSDs are often associated with radiation exposure, expensive cost, or contraindication. Infrared thermography (IRT) is becoming a proposed tool to assist in diagnosing MSDs, but current evidence is inconclusive. Thus, herein we aimed to evaluate the diagnostic accuracy of IRT for MSDs.Methods:We will search EMBASE, MEDLINE, EBSCO, Cochrane Library, SCOPUS, Web of Science, CNKI, SinoMed, and Wangfang. Two researchers will independently screen eligible studies. Study quality will be evaluated based on the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Data synthesis will be completed using STATA 14.0 software. A bivariate random-effects analysis will be utilized to estimate the pooled estimation of the diagnostic odds ratio (DOR) and the summary receiver operating characteristics (SROC) curve. Subgroup analyses will be performed to determine heterogeneity sources.Results:This systematic review and meta-analysis will provide reliable evidence about the diagnostic accuracy of IRT for MSDs.Conclusion:The conclusion of this study will be published in a peer-reviewed journal.Ethics and Communication:Given that this is a systematic review of published research, patient consent and ethical approval are not relevant. The findings of this study will be disseminated through conference presentations and publication in peer-reviewed journals.Prospero registration number:CRD42020184867.  相似文献   
8.
This study aimed at evaluating the thermographic changes associated with localized exercise in young and elderly subjects. An exercise protocol using 1 kg load was applied during 3 min to the knee flexors of 14 elderly (67 ± 5 years) and 15 young (23 ± 2 years) healthy subjects. The posterior thigh’s skin temperature of the exercised limb and contralateral limb were measured by infrared thermography on pre-exercise, immediately post-exercise, and during the 10-min period post-exercise. Difference (p < 0.01) between elderly and young subjects was observed on pre-exercise temperature. Although differences were not observed between pre-exercise and immediately post-exercise temperature in the exercised limb, thermographic profile displayed heat concentration in exercised areas for both groups. Temperature reduction was only observed for the young group on the 10-min post-exercise (p < 0.05) in the exercised limb (30.7 ± 1.7 to 30.3 ± 1.5 °C). In contrast, there was a temperature reduction post-exercise (p < 0.01) in the contralateral limb for both groups. These results present new evidences that elderly and young subjects display similar capacity of heat production; however, the elderly subjects presented a lower resting temperature and slower heat dissipation. This work contributes to improve the understanding about temperature changes in elderly subjects and may present implications to the sports and rehabilitation programs.  相似文献   
9.
红外热像图鉴别诊断乳腺良恶性病变的价值   总被引:2,自引:0,他引:2  
目的探讨红外热像图对乳腺病变性质的鉴别诊断价值.材料与方法对133例单侧乳腺病变患者(经术后病理证实恶性病变53例,良性病变80例)术前进行红外热像图扫描.分析热像图像,并记录病变区温度(T)及其与周围区的温差(△T1),患侧乳头、乳晕及全乳与对侧相应区域的温差(依次△T2,△T3及△T4).结果乳腺癌患者T、△T1、△T2、△T3及△T4值均明显高于乳腺良性病变患者.乳腺恶性病变诊断符合率为90.6%(48/53);良性病变诊断符合率为88.8%(71/80).其良恶性鉴别诊断总符合率为89.5%.结论红外热像图是鉴别诊断乳腺良恶性病变的有效影像学方法,可为临床治疗提供可靠的诊断依据.  相似文献   
10.
It is important to accurately characterize the heating of tissues due to the radiofrequency energy applied during MRI. This has led to an increase in the use of numerical methods to predict specific energy absorption rate distributions for safety assurance in MRI. To ensure these methods are accurate for actual MRI coils, however, it is necessary to compare to experimental results. Here, we report results of some recent efforts to experimentally map temperature change and specific energy absorption rate in a phantom and in vivo where the only source of heat is the radiofrequency fields produced by the imaging coil. Results in a phantom match numerical simulation well, and preliminary results in vivo show measurable temperature increase. With further development, similar methods may be useful for verifying numerical methods for predicting specific energy absorption rate distributions and in some cases for directly measuring temperature changes and specific energy absorption rate induced by the radiofrequency fields in MRI experiments. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.  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