全文获取类型
收费全文 | 1062篇 |
免费 | 70篇 |
国内免费 | 105篇 |
学科分类
医药卫生 | 1237篇 |
出版年
2021年 | 25篇 |
2020年 | 11篇 |
2019年 | 22篇 |
2018年 | 23篇 |
2017年 | 20篇 |
2016年 | 23篇 |
2015年 | 26篇 |
2014年 | 27篇 |
2013年 | 42篇 |
2012年 | 41篇 |
2011年 | 48篇 |
2010年 | 42篇 |
2009年 | 38篇 |
2008年 | 32篇 |
2007年 | 92篇 |
2006年 | 44篇 |
2005年 | 52篇 |
2004年 | 42篇 |
2003年 | 27篇 |
2002年 | 28篇 |
2001年 | 19篇 |
2000年 | 25篇 |
1999年 | 28篇 |
1998年 | 52篇 |
1997年 | 38篇 |
1996年 | 39篇 |
1995年 | 18篇 |
1994年 | 29篇 |
1993年 | 18篇 |
1992年 | 15篇 |
1991年 | 16篇 |
1990年 | 24篇 |
1989年 | 19篇 |
1988年 | 24篇 |
1987年 | 26篇 |
1986年 | 22篇 |
1985年 | 19篇 |
1984年 | 12篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1976年 | 10篇 |
1975年 | 4篇 |
1973年 | 3篇 |
1971年 | 5篇 |
1968年 | 3篇 |
排序方式: 共有1237条查询结果,搜索用时 328 毫秒
1.
目的 本研究使用激光扫描检眼镜(SLO)评价双侧中央暗点患者使用棱镜后的眼球运动反应.方法 本预试验共招募6例有双侧中央暗点的年龄相关性黄斑变性(AMD)患者以及6例正常视力的志愿者.首先用Nidek MP-1微视野仪确认患者的中央暗点和优选视网膜注视点(PRL),然后用Rodenstock SLO,在将视标投射在优选视网膜注视点时拍下实时视网膜像,接着在受检者眼前加入6~8 PD的棱镜,要求受检者保持注视视标,这时通过视网膜标记来测量视网膜像的移位量,以及随后发生的优选视网膜注视点的再次注视.过程中平均移位量和再次注视时间通过图像软件(ImageJ software)来计算.结果 实验组再次注视时的移位量在3个像素点或11.66个弧分之内(x轴:2.90±3.92,y轴:2.53±4.18).对照组再次注视时的移位会准确些(x轴:0.33±1.15,y轴:0.89±2.50),但与实验组差异无统计学意义(tx=1.32,Px>0.05;ty=0.80,Py>0.05).对照组再次注视时间(0.98±0.19)s较实验组(2.83±1.63)s要短,差距有统计学意义(t=5.03,P<0.01).其中有1例实验组受检者没有发生再次注视,其结果被排除并单独分析.结论 研究发现,双眼中央暗点患者对棱镜物像转移后的再注视反应与正常人接近,但实验组再注视明显较对照组慢,并有1例受检者没有发生再注视.该数据说明双侧中央暗点患者无论眼前有没有棱镜,都会利用相同的视网膜位置视物,因此,通过棱镜物像再定位的意义不大. 相似文献
2.
CM Reid M. Nelson P. Beckinsale P. Ryan LMH Wing LJ Beilin MA Brown GLR Jennings CI Johnston J. Marley JJ McNeil TO Morgan J. Shaw ID Steven MJ West 《Clinical and experimental pharmacology & physiology》1997,24(5):370-373
1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial. 相似文献
3.
The prognostic significance of acute renal failure after renal transplantation in patients treated with cyclosporin 总被引:2,自引:0,他引:2
Perez Fontan M; Rodriguez-Carmona A; Bouza P; Valdes F 《QJM : monthly journal of the Association of Physicians》1998,91(1):27-40
We studied 733 cadaveric renal transplant patients (747 transplants) under
cyclosporin immunosuppression, to: (i) establish the risk profile for acute
renal failure (ARF) after renal transplantation in a unit using many
sub-optimal donors; (ii) assess the long-term prognostic relevance of ARF;
and (iii) explore the synergistic prognostic significance of delayed graft
function and acute rejection during the early post-transplant period.
Transplanting from a non-heart-beating or elderly donor, protracted cold
ischaemia, haemodialysis immediately before transplant surgery, poor HLA
matching, and grafting to a hypersensitized recipient without residual
renal function, all independently predicted delayed graft function. This
delay had no detrimental effect on patient or graft survival, but prolonged
ARF was associated with increased mortality from infection. Late markers of
graft dysfunction (poor graft function, proteinuria, hypertension) were
highly prevalent among grafts affected by ARF, specially in prolonged ARF.
Delayed graft function and early acute rejection showed a definite, albeit
not strong, additive impact on late graft survival, and also on the
prevalence of late markers of graft dysfunction.
相似文献
4.
5.
We examined androgen responses in hyperandrogenic (polycystic ovarian disease [PCOD]) and normal women after an acute endogenous insulin elevation. Standard intravenous glucose tolerance tests (IVGTTs), modified to include a tolbutamide injection 20 minutes after IVGTTs, were performed. Polycystic ovarian disease patients were studied in the untreated state, after 6 weeks of ovarian androgen suppression with leuprolide acetate, after a 6-week rest period, and after 6 weeks of antiandrogen therapy with spironolactone. Normal menstruating women were studied during the early follicular, midcycle, and luteal phases of a single cycle. An acute rise in insulin did not alter serum testosterone or androstenedione levels in PCOD or normal women. A significant rise in dehydroepiandrosterone sulfate after modified IVGTTs was found in both hyperandrogenic and normal cycling women. Although these results are not supportive of the theory that insulin acts on the ovary to stimulate androgen production, they may be because of the short time course of insulin elevation that occurs during an IVGTT. 相似文献
6.
7.
8.
9.
10.
BACKGROUND: The recent introduction of urea sensors for dialysis monitoring
has made possible new approaches to urea kinetic modelling. In this study
we show how the equilibrated postdialysis urea concentration (Ceq) and Kt/V
corrected for double-pool urea kinetics (Kt/Vdp) can be accurately
determined using an on-line sensor providing a continuous measure of blood
water urea. A modification of the Smye constant volume double-pool theory
led to the following equations for Ceq and Kt/Vdp [formula: see text] where
Cpre is the blood concentration measured at the start of dialysis, t is the
length of the dialysis session (in min) and S(ex) is the constant slope of
the blood urea logarithm concentration decline following development of the
intercompartmental urea concentration gradient in the first 30-60 min of
dialysis. METHODS: These equations were tested in 11 patients undergoing
165-240 min of paired filtration dialysis with continuous monitoring of
blood urea concentration. Cpre was determined as the plateau concentration
during a preliminary period of 15-20 min of slow isolated ultrafiltration.
S(ex) was accurately determined from linear regression applied to the urea
sensor data from the 80-min point to the end of dialysis. RESULTS: Ceq and
Kt/Vdp determined from the above equations compared closely to values
determined from 25-40 min of urea rebound monitoring with the urea sensor:
10.6 +/- 3.0 versus 10.8 +/- 2.7 mmol/l (mean +/- SD) for Ceq and 1.21 +/-
0.24 versus 1.18 +/- 0.20 for Kt/Vdp, compared to single-pool values of
Kt/V = 1.34 +/- 0.23. CONCLUSION: This technique may be readily programmed
into on-line urea monitors to provide current and extrapolated values of
Ceq and Kt/Vdp from about the first hour of dialysis.
相似文献