全文获取类型
收费全文 | 285篇 |
免费 | 19篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 3篇 |
妇产科学 | 9篇 |
基础医学 | 33篇 |
口腔科学 | 9篇 |
临床医学 | 20篇 |
内科学 | 48篇 |
神经病学 | 6篇 |
特种医学 | 4篇 |
外科学 | 23篇 |
综合类 | 41篇 |
预防医学 | 29篇 |
眼科学 | 11篇 |
药学 | 46篇 |
中国医学 | 22篇 |
肿瘤学 | 11篇 |
出版年
2024年 | 3篇 |
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 13篇 |
2020年 | 15篇 |
2019年 | 10篇 |
2018年 | 12篇 |
2017年 | 9篇 |
2016年 | 3篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 14篇 |
2012年 | 20篇 |
2011年 | 20篇 |
2010年 | 13篇 |
2009年 | 12篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 8篇 |
2003年 | 17篇 |
2002年 | 20篇 |
2001年 | 7篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
排序方式: 共有316条查询结果,搜索用时 15 毫秒
31.
The present study tests the hypothesis that dietary Ca2+ supplementation increases acute diuretic and natriuretic responses to volume loading in the NaCl-sensitive spontaneously hypertensive rat (SHR-S). Seven week old male SHR-S and normotensive Wistar-Kyoto rats (WKY) were fed one of the following diets for 2.5 weeks: basal (0.75% NaCl, 0.68% Ca2+); high NaCl (8% NaCl, 0.68% Ca2+); high Ca2+ (0.75% NaCl, 2.0% Ca2+); and high NaCl and Ca2+ (8% NaCl, 2.0% Ca2+). SHR-S on high Ca2+ and on high NaCl and Ca2+ diets for 2 weeks displayed significantly lower systolic arterial pressures (SAP) than SHR-S on basal and high NaCl diets, respectively. WKY displayed no diet-related change in SAP at any time during the study. After 2.5 weeks on the diets, pre-instrumented, conscious SHR-S and WKY received an intravenous infusion (5% body weight) of isotonic NaCl, and urine was collected through a bladder catheter for a period of 90 min. The infusion did not alter the heart rate or the mean arterial pressure in any group. WKY on the high NaCl diet excreted a significantly greater percentage of the volume and Na+ load than WKY on the basal diet. In contrast, SHR-S on the high NaCl (compared to basal) diet did not display significantly enhanced natriuresis or diuresis. SHR-S on the basal diet displayed excretion rates similar to WKY on the basal diet. Dietary Ca2+ supplementation significantly increased the natriuretic and diuretic responses to saline infusion in SHR-S on the high NaCl diet, but not in SHR-S on the basal diet or in WKY on either diet.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
32.
目的 观察一氧化氮(NO)在妊高征患者血清及胎盘组织中的含量变化。方法用硝酸盐还原酶法检测正常妊娠组(30例)、妊高征组(48例)血清及胎盘组织中的硝酸盐含量。 结果 妊高征患者血清及胎盘组织中硝酸盐含量均明显高于正常妊娠组(P相似文献
33.
Tremor is a continuous, repetitive twitching of skeletal muscles, which is usually visible and palpable. Repeated birth of
lambs with neurological disorders in a herd of the region in Northwest of Kerman province of Iran was the reason for careful
examination one of the patients. The 1-day-old lamb with slowly progressive neurologic disturbances consisting of difficulties
in moving and coordination was transferred to the Veterinary Clinic of Shahid Bahonar University of Kerman. The patient suffered
from ataxia and severe tremor. In clinical examination, significant findings were restricted to the nervous system. The animal
was normal in other respects. At necropsy the meningeal blood vessels were congested and occasional small foci of hemorrhage
was seen. Microscopic findings in the brain included ischemic cell change, laminar necrosis, demyelination, diffuse and focal
gliosis, microcavitation, and hemorrhage. Based on the history, clinical, hematological, biochemical, and histopathologic
findings, a severe degenerative process caused the tremor. This is the first report of congenital tremor in an Iranian Fat-Tailed
lamb. 相似文献
34.
Star‐Like Poly(N‐isopropylacrylamide) and Poly(ethylene glycol) Copolymers Self‐Arranged in Newfound Single Crystals and Associated Novel Class of Polymer Brush Regimes with V‐Type Tethers
下载免费PDF全文
![点击此处可从《Macromolecular chemistry and physics.》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mojgan Mahmoudi Samira Agbolaghi Zahra Mozaffari Saleheh Abbaspoor Bakhshali Massoumi Raana Sarvari Nasrin Hosseinzadeh 《Macromolecular chemistry and physics.》2018,219(10)
Linear poly(ethylene glycol) (PEG)‐block‐poly(N‐isopropylacrylamide) (PNIPAM) and star‐like three‐arm PEG‐star‐(PNIPAM)2 copolymers having one PEG and two PNIPAM blocks are synthesized by atom transfer radical polymerization (ATRP). Single crystals of these block copolymers are grown from amyl acetate and toluene dilute solutions. To recognize PNIPAM and PEG thicknesses, small angle X‐ray scattering (SAXS) is applied. V‐type brushes behave differently from linear brushes because doubly grafted PNIPAM blocks from a common point onto PEG substrate exert a higher osmotic pressure, leading to a thinner crystal. In addition to three ordinary regimes, a fourth or extremely stretched regime is detected for V‐type PNIPAM brushes. Although in PEG5000‐star‐(PNIPAM)2 single crystals with overall PNIPAM molecular weight of 37 000 g/mol, each PNIPAM arm is shorter than PNIPAM grafts in linear PEG5000‐block‐PNIPAM26000 single crystals, their switching point from second to third regime is significantly lower (22 vs 33 °C). The V‐type configuration of PNIPAM brushes cause them to be entered into the extremely stretched or fourth regime, which has not been previously detected for coily brushes. The boundary between third and fourth regimes for PEG5000‐star‐(PNIPAM)2 single crystals is verified at 31.5 and 23.5 °C in amyl acetate and toluene, respectively. 相似文献
35.
36.
Few studies have investigated the presence of dyslipidaemia in hypertensive individuals. In addition, few data exist on the concurrent treatment of both conditions for the prevention of cardiovascular disease (CVD). This retrospective cohort study examined treatment patterns for hypertension and dyslipidaemia among hypertensive patients in UK primary care. We defined a population of patients aged > or =40 years from the UK General Practice Research Database. Hypertensive individuals with > or =3 additional cardiovascular risk factors (ARFs) were compared with a cohort comprising hypertensive patients with < or =2 ARFs. We analysed the prevalence of risk factors and the prevalence and incidence of treatment for hypertension, dyslipidaemia and for both conditions between January 1997 and December 2001. A total of 117 840 hypertensive patients were identified (23 655 with > or =3 ARFs, 94 185 with < or =2 ARFs) in 1997; in 2001, the number diagnosed as hypertensive was 133 683 (40 248 > or =3 ARFs, 93 435 < or =2 ARFs). The prevalence of antihypertensive treatment in the hypertensive patients with > or =3 ARFs increased during the study. In 2001, approximately one-third of hypertensive patients with > or =3 ARFs were not receiving antihypertensives. Among those patients who received such treatment, the majority received > or =2 separate agents in accordance with current guidelines. Treatment for concurrent hypertension and dyslipidaemia was initiated in <8% of patients with hypertension and > or =3 ARFs in each year. These findings demonstrate the under-recognition/undertreatment of cardiovascular risk factors in UK primary care among patients at risk of CVD. 相似文献
37.
Melatonin, a promising supplement in inflammatory bowel disease: a comprehensive review of evidences
Inflammation and oxidative process are associated with inflammatory bowel disease (IBD). Regarding anti-inflammatory and antioxidant potentials, melatonin has been found beneficial in several experimental and clinical studies including inflammatory bowel disease (IBD). Our objective in this study is to review and evaluate all non-clinical and clinical studies on the efficacy of melatonin in IBD. All indexing databases were searched for inflammatory bowel disease' and 'melatonin' keywords, without time limit up to May 2011. Three clinical trials and fifteen non-clinical studies are reviewed and analyzed. The majority of these studies indicate that melatonin has a positive impact on IBD with no or negligible side effects. Such results have been mostly explained through free radical scavenging and diminishing inflammation. It is yet crucial to determine the efficacy of melatonin in combination with other established drugs in more clinical trials, not only for further confirmation of its efficacy, but also to investigate its possible side effects in longer durations of therapy. 相似文献
38.
NK-cell and T-cell functions in patients with breast cancer: effects of surgery and adjuvant chemo- and radiotherapy 总被引:2,自引:0,他引:2
Mozaffari F Lindemalm C Choudhury A Granstam-Björneklett H Helander I Lekander M Mikaelsson E Nilsson B Ojutkangas ML Osterborg A Bergkvist L Mellstedt H 《British journal of cancer》2007,97(1):105-111
Breast cancer is globally the most common malignancy in women. Her2-targeted monoclonal antibodies are established treatment modalities, and vaccines are in late-stage clinical testing in patients with breast cancer and known to promote tumour-killing through mechanisms like antibody-dependent cellular cytotoxicity. It is therefore increasingly important to study immunological consequences of conventional treatment strategies. In this study, functional tests and four-colour flow cytometry were used to detect natural killer (NK)-cell functions and receptors as well as T-cell signal transduction molecules and intracellular cytokines in preoperative breast cancer patients, and patients who had received adjuvant radiotherapy or adjuvant combined chemo-radiotherapy as well as in age-matched healthy controls. The absolute number of NK cells, the density of NK receptors as well as in vitro quantitation of functional NK cytotoxicity were significantly higher in preoperative patients than the post-treatments group and controls. A similar pattern was seen with regard to T-cell signalling molecules, and preoperative patients produced significantly higher amounts of cytokines in NK and T cells compared to other groups. The results indicate that functions of NK and T cells are well preserved before surgery but decrease following adjuvant therapy, which may speak in favour of early rather than late use of immunotherapeutic agents such as trastuzumab that may depend on intact immune effector functions. 相似文献
39.
Christian M Sauer Damian H Tomlin Homayoun Mozaffari Naeini Oleg Gerovichev Nitish V Thakor 《Computer aided surgery》2002,7(6):364-370
Measurement and feedback of vascular properties during microsurgery is generally not available. We carried out real-time in vivo measurement and analysis of microsurgical occlusion of 1-2-mm diameter arteries and veins in rodents. A pair of forceps mounted with strain gauges was designed for applying and directly measuring the force on tissue. Forces between 0 and 450 mN were applied, with the device having a resolution of 0.5 mN. We performed in vivo experiments on the rat femoral (n = 5) and abdominal (n = 8) blood vessels to measure the elastic restoration force of the tissue in response to radial compression at different levels of force. On average, the minimum occlusion force was 57 mN for the rat artery. During steady application of force, the perturbations in the blood vessel due to heartbeat are visible in the force data. These force oscillations ranged between 1 and 3 mN around the mean steady-state force applied. It was determined that the magnitude of the Fourier spectral peak corresponding to heartbeat frequency can be used as a measure of the patency of the blood vessel, and can provide feedback to microsurgeons to avoid damage to the vessel by application of excess force. 相似文献
40.
目的探讨自制心电监护仪导联线保护套对胸心外科危重患者监护效果的影响,以提高心电监护仪导联线的使用寿命,减少科室的耗材成本。方法便利抽样法选择2012年1月至2012年9月在贵港市人民医院抢救室应用心电监护的危重患者124例为研究对象,按入院时间先后将其分为观察组和对照组,每组各62例。观察组用绝缘胶布包裹破损处心电监护仪导联线并埋入剖开的一次性输液管腔内对患者进行监护,对照组直接用绝缘胶布包裹破损心电监护仪导联线对患者进行心电监护。观察两组患者心电示波被干扰的现象及导联线上绝缘胶布松脱的时间。结果两组患者心电示波被干扰现象比较,差异无统计学意义(均P>0.05);观察组患者心电监护导联线出现绝缘胶布松脱时间明显长于对照组,差异有统计学意义(P<0.05)。结论应用自制心电监护仪导联线保护套对患者进行心电监护,监护效果不受影响,但能有效提高心电监护仪导联线的使用寿命,减少科室的耗材成本,值得推广应用。 相似文献