全文获取类型
收费全文 | 250篇 |
免费 | 8篇 |
国内免费 | 12篇 |
专业分类
儿科学 | 13篇 |
妇产科学 | 6篇 |
基础医学 | 31篇 |
口腔科学 | 5篇 |
临床医学 | 25篇 |
内科学 | 84篇 |
皮肤病学 | 3篇 |
神经病学 | 11篇 |
特种医学 | 23篇 |
外科学 | 11篇 |
综合类 | 10篇 |
预防医学 | 21篇 |
眼科学 | 5篇 |
药学 | 15篇 |
肿瘤学 | 7篇 |
出版年
2023年 | 1篇 |
2021年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 8篇 |
2015年 | 5篇 |
2014年 | 11篇 |
2013年 | 10篇 |
2012年 | 20篇 |
2011年 | 28篇 |
2010年 | 11篇 |
2009年 | 9篇 |
2008年 | 17篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 16篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1968年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有270条查询结果,搜索用时 15 毫秒
81.
82.
紫外分光光度法测定平阳霉素霜的含量 总被引:2,自引:0,他引:2
目的:用紫外分光光度法测定平阳霉素霜的含量,为该药提供质量控制方法。方法:紫外分光光度法。结果:平阳霉素甲醇液在293.5nm处有最大吸收,在30-70μg/ml范围内吸收度与浓度有良好线性关系,其回归方程为A=0.01066C-0.008(r=0.9998),平均回收率(n=5)为100.05%,RSD=0.98%。结论:该法作为平阳霉素霜剂的含量测定方法、快捷准确、简便易行,适用于医院快检。 相似文献
83.
Potential role of platelet FcgammaRIIA in collagen-mediated platelet activation associated with atherothrombosis 总被引:2,自引:0,他引:2
Calverley DC Brass E Hacker MR Tsao-Wei DD Espina BM Pullarkat VA Hodis HN Groshen S 《Atherosclerosis》2002,161(2):261-267
Increased levels of hemostatic factors may play a role in the pathogenesis of myocardial infarction by triggering thrombin formation. We measured factor XII (FXII), factor XI (FXI), plasma prekallikrein (PK) and high-molecular-weight kininogen (HK) in 200 patients having survived myocardial infarction for at least 2 months, and in 100 healthy controls. We found significantly elevated levels of FXI clotting activity (FXI:C), HK:C and of the amidolytic activity of PK (PK:Am) among the patients as compared to the controls. Plasma levels of FXI:C, HK:C and PK:Am in the highest quartile were associated with an odds ratio of 1.9 (95% CI: 1.0-3.8), 2.0 (95% CI: 1.0-4.0) and 5.4 (95% CI: 2.6-11.2), respectively, compared to the respective plasma levels in the lowest quartile. After correction for established clinical and laboratory risk factors, the association between PK:Am plasma levels and myocardial infarction remained significant (P=0.0007). Combination of high PK:Am plasma levels and smoking or arterial hypertension, respectively, resulted in a more than additive relative risk for myocardial infarction. 相似文献
84.
Relationship between serum levels of sex hormones and progression of subclinical atherosclerosis in postmenopausal women 总被引:1,自引:0,他引:1
Karim R Hodis HN Stanczyk FZ Lobo RA Mack WJ 《The Journal of clinical endocrinology and metabolism》2008,93(1):131-138
BACKGROUND: Postmenopausal hormone therapy has been examined extensively in relation to cardiovascular disease. However, research relating serum levels of sex hormones to cardiovascular disease is sparse, and the results are inconclusive. METHODS: We measured sex hormones in longitudinally collected samples of 180 postmenopausal women, 91 randomized to 17beta-estradiol and 89 to placebo, in the Estrogen in the Prevention of Atherosclerosis Trial. Repeated measures of sex hormone levels were tested for an association with carotid artery intima-media thickness (CIMT), which was also assessed longitudinally over 2 yr. RESULTS: In all women, changes in serum estrone (P = 0.02), total estradiol (P = 0.01), free estradiol (P = 0.02), and SHBG (P = 0.005) were significantly inversely associated with CIMT progression, controlling for age and body mass index. All the estrogen compounds and SHBG were significantly inversely related with low-density lipoprotein cholesterol and positively associated with high-density lipoprotein cholesterol (all P < 0.0001), whereas free testosterone was positively related with low-density lipoprotein cholesterol and inversely associated with high-density lipoprotein cholesterol (P < 0.003). Despite an increase in serum-free estradiol with estradiol therapy, women with unchanged SHBG and free testosterone levels had an average (se) progression in CIMT of 8.53 (4.72) microm/yr, whereas women with increased free estradiol and SHBG and decreased free testosterone had the largest reduction in CIMT progression [-5.45 (2.77) microm/yr; trend P = 0.03]. CONCLUSION: Estrogen and SHBG are associated with reduced subclinical atherosclerosis progression in healthy postmenopausal women. These associations are partially mediated by their beneficial effects on lipids. Among women taking estradiol, the most beneficial hormone profile for CIMT progression was increased free estradiol and SHBG with concomitant decreased free testosterone. 相似文献
85.
Please cite this paper as: WHO/OIE/FAO. (2012) Continued evolution of highly pathogenic avian influenza A(H5N1): Updated nomenclature. Influenza and Other Respiratory Viruses 6(1), 1–5. Background Continued evolution of highly pathogenic avian influenza A (H5N1) throughout many regions of the eastern hemisphere has led to the emergence of new phylogenetic groups. A total of 1637 new H5N1 hemagglutinin (HA) sequences have become available since the previous nomenclature recommendations described in 2009 by the WHO/OIE/FAO H5N1 Evolution Working Group. A comprehensive analysis including all the new data is needed to update HA clade nomenclature. Methods Phylogenetic trees were constructed from data sets of all available H5N1 HA sequences. New clades were designated on the basis of phylogeny and p‐distance using the pre‐established nomenclature system (Emerg Infec Dis 2008; 14:e1). Each circulating H5N1 clade was subjected to further phylogenetic analysis and nucleotide sequence divergence calculations. Results All recently circulating clades (clade 1 in the Mekong River Delta, 2.1.3 in Indonesia, 2.2 in India/Bangladesh, 2.2.1 in Egypt, 2.3.2, 2.3.4 and 7 in Asia) required assignment of divergent HA genes to new second‐, third‐, and/or fourth‐order clades. At the same time, clades 0, 3, 4, 5, 6, 8, 9, and several second‐ and third‐order groups from clade 2 have not been detected since 2008 or earlier. Conclusions New designations are recommended for 12 HA clades, named according to previously defined criteria. In addition, viruses from 13 clades have not been detected since 2008 or earlier. The periodic updating of this dynamic classification system allows continued use of a unified nomenclature in all H5N1 studies. 相似文献
86.
Estrogen in the prevention of atherosclerosis. A randomized, double-blind, placebo-controlled trial.
H N Hodis W J Mack R A Lobo D Shoupe A Sevanian P R Mahrer R H Selzer C R Liu Cr C H Liu Ch S P Azen 《Annals of internal medicine》2001,135(11):939-953
BACKGROUND: Although observational studies suggest that estrogen replacement therapy (ERT) reduces cardiovascular morbidity and mortality in postmenopausal women, use of unopposed ERT for prevention of coronary heart disease in healthy postmenopausal women remains untested. OBJECTIVE: To determine the effects of unopposed ERT on the progression of subclinical atherosclerosis in healthy postmenopausal women without preexisting cardiovascular disease. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: University-based clinic. PATIENTS: 222 postmenopausal women 45 years of age or older without preexisting cardiovascular disease and with low-density lipoprotein cholesterol levels of 3.37 mmol/L or greater (>/=130 mg/dL). INTERVENTION: Unopposed micronized 17beta-estradiol (1 mg/d) or placebo. All women received dietary counseling. Women received lipid-lowering medication if their low-density lipoprotein cholesterol level exceeded 4.15 mmol/L (160 mg/dL). MEASUREMENTS: The rate of change in intima-media thickness of the right distal common carotid artery far wall in computer image processed B-mode ultrasonograms obtained at baseline and every 6 months during the 2-year trial. RESULTS: In a multivariable mixed-effects model, among women who had at least one follow-up measurement of carotid intima-media thickness (n = 199), the average rate of progression of subclinical atherosclerosis was lower in those taking unopposed estradiol than in those taking placebo (-0.0017 mm/y vs. 0.0036 mm/y); the placebo-estradiol difference between average progression rates was 0.0053 mm/y (95% CI, 0.0001 to 0.0105 mm/y) (P = 0.046). Among women who did not receive lipid-lowering medication (n = 77), the placebo-estradiol difference between average rates of progression was 0.0147 mm/y (CI, 0.0055 to 0.0240) (P = 0.002). Average rates of progression did not differ between estradiol and placebo recipients who took lipid-lowering medication (n = 122) (P > 0.2). CONCLUSIONS: Overall, the average rate of progression of subclinical atherosclerosis was slower in healthy postmenopausal women taking unopposed ERT with 17beta-estradiol than in women taking placebo. Reduction in the progression of subclinical atherosclerosis was seen in women who did not take lipid-lowering medication but not in those who took these medications. 相似文献
87.
Hodis HN St John JA Xiang M Cushman M Lobo RA Mack WJ 《The American journal of cardiology》2008,101(8):1131-1133
The objective of this study was to determine whether high-sensitivity C-reactive protein (hs-CRP) and serum soluble intercellular adhesion molecule-1 (sICAM-1) correlate with progression of subclinical atherosclerosis. Secondarily, the long-term effect of oral estradiol on hs-CRP and sICAM-1 were determined. Data were analyzed from 180 healthy postmenopausal women aged 45 to 80 years randomly assigned to either unopposed micronized 17beta-estradiol 1 mg/day or placebo in the Estrogen in the Prevention of Atherosclerosis Trial (EPAT). Carotid artery intima-media thickness (CIMT), hs-CRP, and sICAM-1 were measured at baseline and every 6 months thereafter for 2 years. Unopposed 17beta-estradiol significantly increased hs-CRP (p = 0.01) and decreased sICAM-1 compared with placebo (p = 0.04). Changes in hs-CRP and sICAM-1 did not correlate with changes in carotid artery intima-media thickness. In conclusion, although unopposed 17beta-estradiol significantly altered hs-CRP and sICAM-1, neither marker was associated with progression of subclinical atherosclerosis. 相似文献
88.
目的:总结应用多轴向钛螺钉-棒系统椎弓根钉植入技术治疗寰枢椎损伤的特点。方法:选择山东省东营市人民医院、加拿大脊柱外科中心、山东省立医院脊柱外科1999-01/2004-01治疗的寰枢椎损伤患者。应用后路多轴向钛螺钉-棒系统固定融合手术治疗38例,固定位置为寰椎(C1)的双侧块和枢椎(C2)的椎弓根,并与46例采用关节突螺钉复合后方椎板下钢丝固定植骨融合进行对比分析。结果:84例患者全部进入结果分析。①治疗组脊髓损伤的治愈率和总有效率(治愈 有效)高于对照组,但差异无显著性(92%,85%,χ2=0.29,P>0.05)。②治疗组对椎动脉孔的入侵率明显低于对照组(5%,30%,χ2=6.99,P<0.05)。③治疗组对椎管的入侵率明显低于对照组(5%,28%,χ2=6.02,P<0.05)。④术后治疗组α角(寰枢椎角)为(26.8±5.42)°,对照组α角为(25.6±5.82)°,两组对比差异无显著性(t=1.27,P>0.05)。⑤治疗组1例轻度错位(≤7mm),1例神经轻度放射痛,术后5个月取出内固定后消失,余无固定松动、椎动脉损伤、神经压迫征发生,3个月融合28例,6个月全部融合。对照组4例出现骨折所致不稳,3例半脱位,5例不融合,6例神经痛。结论:对急性寰、枢椎损伤患者进行C1双侧块和C2椎弓根后路多轴向钉-棒系统固定融合手术治疗方法简单、易于避开椎动脉,定位准确,直视下进行操作,安全性高,固定可靠。 相似文献
89.
Impaired coronary artery distensibility is an endothelium‐dependent process and is associated with vulnerable plaque composition
下载免费PDF全文
![点击此处可从《Clinical physiology and functional imaging》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Naser Ahmadi Juan Ruiz‐Garcia Fereshteh Hajsadeghi Stanley Azen Wendy Mack Howard Hodis Amir Lerman 《Clinical physiology and functional imaging》2016,36(4):261-268
Coronary endothelial‐dependent microvascular dysfunction, an early reversible stage of coronary artery disease (CAD), is associated with poor clinical outcome. The current study investigated whether coronary artery distensibility index (CDI) is associated with: (i) coronary endothelial‐dependent microvascular dysfunction and (ii) vulnerable plaque composition among subjects with non‐obstructive CAD. Seventy‐four subjects with non‐obstructive CAD (luminal stenosis <30%) were studied. In 20 subjects with and without coronary endothelial‐dependent microvascular dysfunction, coronary flow reserve (CFR) of target segment during intracoronary (IC) infusion of acetylcholine (Ach) and bolus injection of adenosine as well as CDI at rest of corresponding target segment were measured. In 54 subjects, plaque compositions and CDI at rest of 154 non‐obstructive coronary segments as well as proximal segment without disease were measured by intravascular ultrasound (IVUS). CDI was defined as: [(Early‐diastolic cross‐sectional‐area (CSA) – End‐diastolic CSA of target segment)/(end‐diastolic CSA of target segment × coronary‐pulse‐pressure) × 103]. There is a direct association between endothelial dysfunction and impaired CDI of a coronary segment both in the given coronary segment and corresponding microvessels in which a strong agreement between CDI and CFR Ach (r2 = 0·85, P = 0·0001) was observed. Multivariable regression‐analysis showed that CDI was an independent predictor of the vulnerable plaque characteristics. The risk of impaired CDI was 125% higher in segments with necrotic core and 60% higher in segments with fibrofatty components as compared to normal segments (P = 0·001). In conclusions, the current study reveals that impaired CDI is an endothelial‐dependent process of both given coronary segment and corresponding microvessels and is associated with vulnerable plaque composition. 相似文献
90.
“Headache Tools to Stay in School”: Assessment,Development, and Implementation of an Educational Guide for School Nurses
下载免费PDF全文
![点击此处可从《The Journal of school health》网站下载免费的PDF全文](/ch/ext_images/free.gif)