全文获取类型
收费全文 | 865篇 |
免费 | 58篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 47篇 |
妇产科学 | 13篇 |
基础医学 | 96篇 |
口腔科学 | 31篇 |
临床医学 | 149篇 |
内科学 | 189篇 |
皮肤病学 | 37篇 |
神经病学 | 22篇 |
特种医学 | 132篇 |
外科学 | 61篇 |
综合类 | 37篇 |
预防医学 | 45篇 |
眼科学 | 5篇 |
药学 | 51篇 |
中国医学 | 2篇 |
肿瘤学 | 18篇 |
出版年
2023年 | 3篇 |
2021年 | 13篇 |
2020年 | 13篇 |
2019年 | 21篇 |
2018年 | 11篇 |
2017年 | 17篇 |
2016年 | 19篇 |
2015年 | 27篇 |
2014年 | 29篇 |
2013年 | 38篇 |
2012年 | 22篇 |
2011年 | 19篇 |
2010年 | 51篇 |
2009年 | 41篇 |
2008年 | 27篇 |
2007年 | 35篇 |
2006年 | 20篇 |
2005年 | 21篇 |
2004年 | 16篇 |
2003年 | 18篇 |
2002年 | 14篇 |
2001年 | 14篇 |
2000年 | 14篇 |
1999年 | 12篇 |
1998年 | 46篇 |
1997年 | 40篇 |
1996年 | 38篇 |
1995年 | 25篇 |
1994年 | 33篇 |
1993年 | 28篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 14篇 |
1989年 | 20篇 |
1988年 | 18篇 |
1987年 | 20篇 |
1986年 | 12篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 16篇 |
1981年 | 9篇 |
1980年 | 15篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 14篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1956年 | 3篇 |
1955年 | 2篇 |
排序方式: 共有940条查询结果,搜索用时 31 毫秒
91.
SINAA AL‐AGEEL RACHEL ELLIOTT PETER NOYCE 《The International journal of pharmacy practice》2001,9(Z1):37-37
□ The aim of the study was to obtain perioperative patient‐specific costs associated with orthopaedic anaesthesia □ A prospective observational study design was used to determine fixed, semi‐fixed, and variable costs □ The preliminary results of the first 60 patients reports a mean total perioperative anaesthetic cost of £291 (SD: £103.9, median: £278.09, IQR: £219.3–£369.5) □ Fixed and semi‐fixed costs are a major cost component of anaesthesia; variable costs account for only 12 per cent of total cost □ The results of this study will be used in an economic evaluation examining the use of different anaesthetic techniques in orthopaedics 相似文献
92.
Patients with the syndrome of chronic daily headache often report migrainous symptoms and consequently are diagnosed as having a primary headache syndrome. We report two cases of idiopathic intracranial hypertension causing chronic daily headache with migrainous features in the absence of associated papilledema. 相似文献
93.
94.
The purpose of this study is to examine the effect of percutaneous transluminal coronary angioplasty (PTCA) on quality of life. Secondary purposes are to determine if there is an improvement in state anxiety and physical functioning after PTCA. Data on quality of life in these patients will provide physicians, nurses and other health professionals with a basis to help the angioplasty patient adjust after the procedure. This information will add to the present body of knowledge, serve as a basis for patient education and guide further research. In addition, data on the subjective perception of quality of life may provide an additional index of success or failure of therapy. Subjects scheduled for elective PTCA were mailed a study packet containing three questionnaires. Prior to their admission to the hospital for a scheduled PTCA, subjects completed the Quality of Life Index (QLI), Spielberger's State-Trait Anxiety Inventory and the Physical Functioning Questionnaire. Demographic data were collected from subjects' medical records. Six weeks after a successful PTCA, a second study packet was mailed to subjects. Twenty subjects participated in the study. The majority were employed, Caucasian males with multivessel coronary artery disease and had complained of symptoms less than three months. Paired t-tests demonstrated improvement in the (1) health and functioning subscale (p = less than 0.034), (2) decrease in state anxiety (p = less than 0.030), and (3) increase (p = less than 0.000) in perceived physical functioning. In addition, an inverse relationship was demonstrated between state anxiety and quality of life (r = -0.70, p = 0.000).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
95.
PM Braillon AL Guibal P Pracros-Deffrenne A Serban JP Pracros P Chatelain 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(9):924-929
Ninety five normal Caucasian subjects (51F, 44 M) aged from 2 to 25 y were measured at the hand and wrist level with a small DXA system (pDEXA™) in order to obtain the normal values of the bone mineral content (BMC), density (BMD) and projected area (A) of carpal (c) and metacarpal (m) bones. BMDc ranged from 0.065 ± 0.007 g/cm to 0.365 ± 0.035 g/cm in females and 0.425 ± 0.040 g/cm in males. It presented a sharp change of increase rate at 15.5 and 17 y of age in girls and boys, respectively. Ac presented the same kind of evolution as BMDc, but had a larger value dispersion. The second metacarpal bone had the highest BMCm value in 85% of females and 90% of males. The sum of BMCmi or Ami values (i = 1–5) and the projected mean density of the 5 metacarpal bones was well correlated with BMCc, Ac and BMDc, respectively ( r > 0.90). A volumetric mineral density, dmi, calculated for each of these bones, approximated to a cylinder, was correlated with age ( r > 0.85). 相似文献
96.
Allergic contact dermatitis from propyl gallate: dose response comparison using various application methods 总被引:1,自引:1,他引:0
The antioxidant propyl gallate, in a deodorant product, caused an allergic contact dermatitis in 1 subject during developmental controlled use testing. Subsequent dose response elicitation studies with this subject revealed a differing threshold of sensitivity to propyl gallate dependent upon application method. Increasing the level of occlusion increased the elicitation response. Responsiveness from greatest to least was: occluded patch on the upper arm greater than semi-occluded axilla greater than open application on the antecubital fossa. The thresholds determined for propyl gallate (w/v in 25:75 ethanol:water) were: (a) 0.0025% for the upper arm occluded patch; (b) 0.0035% for the underarm without shaving; (c) 0.005% for the underarm with shaving; (d) 0.015% for the antecubital fossa. Occluded patch responsiveness to propyl gallate was monitored and remained unchanged throughout a 2-year period. These data are useful in understanding the relationship between occlusive allergic contact dermatitis patch testing and clinical contact dermatitis. 相似文献
97.
98.
Gamma-carboxylated isoforms of recombinant human protein S with different biologic properties 总被引:3,自引:0,他引:3
Grinnell BW; Walls JD; Marks C; Glasebrook AL; Berg DT; Yan SB; Bang NU 《Blood》1990,76(12):2546-2554
Human protein S (HPS), a regulator of hemostasis, is a vitamin K- dependent plasma protein with potential clinical utility. We have obtained high-level expression of the cDNA for HPS in two mammalian cell lines. Both cell lines secreted single chain recombinant HPS (rHPS) in serum-free medium as determined by Western blot analysis. The ability of the rHPS from both cell lines to act as a cofactor for human protein C (HPC) was determined; the rHPS secreted from the human 293 cell line had an activity six times that of the rHPS from the AV12-664 Syrian hamster cell line. Furthermore, the relative specific cofactor activity of rHPS from the 293 cell line was actually 2.5-fold higher than that of single-chain human plasma-derived HPS. Essentially all of the rHPS secreted from the 293 cell line exhibited a calcium-dependent elution profile on anion exchange chromatography, whereas only 25% to 35% of the hamster cell-derived rHPS exhibited this profile. However, the calcium-eluted rHPS from the AV12 cell line had a high specific cofactor activity, equivalent to that of the 293-derived rHPS. A NaCl- elutable rHPS fraction (calcium nondependent) was isolated from the recombinant AV12-664 cell line, further purified, and found to have reduced activity, only 40% that of the calcium-dependent rHPS. The only observable difference in the calcium-dependent and nondependent rHPS molecules was in the content of gamma-carboxyglutamic acid (Gla); the calcium-dependent material contained approximately 10 mol Gla/mol protein whereas the calcium-nondependent material contained only approximately 8 mol Gla/mol of protein. In addition, the calcium- nondependent rHPS had reduced ability to interact with phospholipid vesicles as evidenced by an eightfold increase in the apparent kd. Our data demonstrate the isolation of rHPS with high specific activity, and show that a reduction in as few as two Gla residues dramatically decreases its functional cofactor activity for HPC, due to a reduction in ability to interact with the phospholipid bilayer. 相似文献
99.
Does reducing capacitance have potential for further miniaturisation of implantable defibrillators? 下载免费PDF全文
E. Alt F. Evans P. D. Wolf J. Pasquantonio L. Stotts S. Heinz A. Schmig 《Heart (British Cardiac Society)》1997,77(3):234-237
OBJECTIVE: To determine whether considerably smaller capacitors could replace 125 microF capacitors as the standard for use in implantable defibrillators. METHODS: Measured energy, impedance, voltage, and current delivered were compared at defibrillation threshold in 10 mongrel dogs for defibrillation using 75 microF and 125 microF capacitors alternated randomly. Defibrillation was attempted with biphasic shocks of comparable tilt between an endocardial lead in the right ventricular apex and a "dummy" active can of an experimental implantable device placed in the subpectoral position. RESULTS: A reduction of capacitor size of 40% was associated with an increase in voltage of 21% and in current of 22%. With a 65% tilt, no significant differences were found between the two capacitances with respect to the impedance or energy required for defibrillation. CONCLUSIONS: Multiple advances in electrode material, electrode configuration, shock morphology, and shock polarity have reduced defibrillation energy requirements. Smaller capacitors could be used in implantable cardioverter/defibrillators without a major decrease in effectiveness. 相似文献
100.
Eric E. Smith MD MPH Martin O'Donnell MD PhD Gilles Dagenais MD MSc Scott A. Lear PhD Andreas Wielgosz MD PhD Mukul Sharma MD MSc Paul Poirier MD PhD Grant Stotts MD Sandra E. Black MD Stephen Strother PhD Michael D. Noseworthy PhD PEng Oscar Benavente MD Jayesh Modi MD Mayank Goyal MD Saima Batool MD Karla Sanchez BSc Vanessa Hill Cheryl R. McCreary PhD Richard Frayne PhD Shofiqul Islam MSc Jane DeJesus BSc Sumathy Rangarajan MSc Koon Teo MD PhD Salim Yusuf MBBS DPhil 《Annals of neurology》2015,77(2):251-261