全文获取类型
收费全文 | 1239篇 |
免费 | 93篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 62篇 |
妇产科学 | 20篇 |
基础医学 | 142篇 |
口腔科学 | 32篇 |
临床医学 | 181篇 |
内科学 | 208篇 |
皮肤病学 | 36篇 |
神经病学 | 157篇 |
特种医学 | 89篇 |
外科学 | 119篇 |
综合类 | 19篇 |
一般理论 | 2篇 |
预防医学 | 97篇 |
眼科学 | 21篇 |
药学 | 84篇 |
中国医学 | 1篇 |
肿瘤学 | 56篇 |
出版年
2023年 | 11篇 |
2021年 | 16篇 |
2020年 | 13篇 |
2019年 | 22篇 |
2018年 | 19篇 |
2017年 | 14篇 |
2016年 | 17篇 |
2015年 | 27篇 |
2014年 | 31篇 |
2013年 | 56篇 |
2012年 | 56篇 |
2011年 | 59篇 |
2010年 | 50篇 |
2009年 | 56篇 |
2008年 | 52篇 |
2007年 | 61篇 |
2006年 | 58篇 |
2005年 | 34篇 |
2004年 | 46篇 |
2003年 | 34篇 |
2002年 | 30篇 |
2001年 | 22篇 |
2000年 | 19篇 |
1999年 | 35篇 |
1998年 | 41篇 |
1997年 | 33篇 |
1996年 | 23篇 |
1995年 | 16篇 |
1994年 | 21篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 14篇 |
1989年 | 15篇 |
1988年 | 19篇 |
1987年 | 15篇 |
1986年 | 19篇 |
1985年 | 15篇 |
1984年 | 22篇 |
1983年 | 13篇 |
1982年 | 19篇 |
1981年 | 12篇 |
1979年 | 12篇 |
1978年 | 11篇 |
1977年 | 11篇 |
1976年 | 13篇 |
1975年 | 11篇 |
1974年 | 12篇 |
1972年 | 11篇 |
1968年 | 12篇 |
1967年 | 10篇 |
排序方式: 共有1350条查询结果,搜索用时 15 毫秒
81.
PR Hunziker S Smith M Scherrer-Crosbie N Liel-Cohen RA Levine R Nesbitt SA Benton MH Picard 《Circulation》1999,99(5):1-6
Background--Currently, the reporting and archiving of echocardiographic data suffer from the difficulty of representing heart motion on printable 2-dimensional (2D) media. Methods and Results--We studied the capability of holography to integrate motion into 2D echocardiographic prints. Images of normal human hearts and of a variety of mitral valve function abnormalities (mitral valve prolapse, systolic anterior motion of the mitral leaflets, and obstruction of the mitral valve by a myxoma) were acquired digitally on standard echocardiographic machines. Images were processed into a data format suitable for holographic printing. Angularly multiplexed holograms were then printed on a prototype holographic "laser" printer, with integration of time in vertical parallax, so that heart motion became visible when the hologram was tilted up and down. The resulting holograms displayed the anatomy with the same resolution as the original acquisition and allowed detailed study of valve motion with side-by-side comparison of normal and abnormal findings. Comparison of standard echocardiographic measurements in original echo frames and corresponding hologram views showed an excellent correlation of both methods (P<0.0001, r2=0.979, mean bias=2.76 mm). In this feasibility study, both 2D and 3D holographic images were produced. The equipment needed to view these holograms consists of only a simple point-light source. Conclusions--Holographic representation of myocardial and valve motion from echocardiographic data is feasible and allows the printing on a 2D medium of the complete heart cycle. Combined with the recent development of online holographic printing, this novel technique has the potential to improve reporting, visualization, and archiving of echocardiographic imaging. 相似文献
82.
83.
84.
The distinction between true and suspected poisoning in children has not been made clear in previous work on childhood poisoning. A study of suspected poisoning in children under 15 years of age in a defined population of North East Bristol from November 1970 to July 1973 carried out by the Health Education Council Medical Research Division included 53,000 child-years at risk. The number of suspected poisonings was 3-4/1000 population aged under 15 years per year, with a higher incidence in younger age groups. Detailed investigation of the circumstances of the accidents carried out by a multidisciplinary team showed that at least 65%, and possibly as many as 78% were poisoning scares and not true poisoning. The evidence used by the casualty doctor and by the parents to diagnose poisoning was explored, and in many cases was circumstantial. Children with fathers in nonmanual occupations were over-represented. This may reflect differences in patterns of utilization behaviour rather than true differences in incidence. 相似文献
85.
Mark Russell David Benton Michael Kingsley 《Journal of Science and Medicine in Sport》2012,15(4):348-354
ObjectivesThis study investigated the influence of carbohydrate supplementation on skill performance throughout exercise that replicates soccer match-play.DesignExperimentation was conducted in a randomised, double-blind and cross-over study design.MethodsAfter familiarization, 15 professional academy soccer players completed a soccer match simulation incorporating passing, dribbling and shooting on two separate occasions. Participants received a 6% carbohydrate–electrolyte solution (CHO) or electrolyte solution (PL). Precision, success rate, ball speed and an overall index (speed-precision-success; SPS) were determined for all skills. Blood samples were taken at rest, immediately before exercise, every 15 min during exercise (first half: 15, 30 and 45 min; second half: 60, 75 and 90 min), and 10 min into the half time (half-time).ResultsCarbohydrate supplementation influenced shooting (time × treatment interaction: p < 0.05), where CHO attenuated the decline in shot speed and SPS index. Supplementation did not affect passing or dribbling. Blood glucose responses to exercise were influenced by supplementation (time × treatment interaction: p < 0.05), where concentrations were higher at 45 min and during half-time in CHO compared with PL. Blood glucose concentrations reduced by 30 ± 1% between half-time and 60 min in CHO.ConclusionsCarbohydrate supplementation attenuated decrements in shooting performance during simulated soccer match-play; however, further research is warranted to optimise carbohydrate supplementation regimes for high-intensity intermittent sports. 相似文献
86.
A five-drug remission induction regimen with intensive consolidation for adults with acute lymphoblastic leukemia: cancer and leukemia group B study 8811 总被引:23,自引:13,他引:23
Larson RA; Dodge RK; Burns CP; Lee EJ; Stone RM; Schulman P; Duggan D; Davey FR; Sobol RE; Frankel SR 《Blood》1995,85(8):2025-2037
The goal of this phase II multicenter clinical trial was to evaluate a new intensive chemotherapy program for adults with untreated acute lymphoblastic leukemia (ALL) and to examine prospectively the impact of clinical and biologic characteristics on the outcome. One hundred ninety-seven eligible and evaluable patients (16 to 80 years of age; median, 32 years of age) received cyclophosphamide, daunorubicin, vincristine, prednisone, and L-asparaginase; 167 patients (85%) achieved a complete remission (CR), 13 (7%) had refractory disease, and 17 (9%) died during induction. A higher CR rate was observed in younger patients (94% for those < 30 years old, 85% for those 30 to 59 years old, and 39% for those > or = 60 years old, P < .001) and in those who had a mediastinal mass (100%) or blasts with a T-cell immunophenotype. Eighty percent of B-lineage and 97% of T-cell ALL patients achieved a CR (P = .01). The coexpression of myeloid antigens did not affect the response rate or duration. Seventy percent of those with cytogenetic or molecular evidence of the Philadelphia (Ph) chromosome and 84% of those without such evidence achieved a CR (P = .11). Patients in remission received multiagent consolidation treatment, central nervous system prophylaxis, late intensification, and maintenance chemotherapy for a total of 24 months. After a median follow-up time of 43 months, the median survival for all 197 patients is 36 months; the median remission duration for the 167 CR patients is 29 months. Favorable pretreatment characteristics relative to remission duration or survival are younger age, the presence of a mediastinal mass or lymphadenopathy, a white blood cell count (WBC) less than 30,000/microL, L1 morphology, T or TMy immunophenotype, and the absence of the Ph chromosome. The estimates of the proportion surviving at 3 years are 69% for patients less than 30 years old, 39% for those 30 to 59 years old, 89% for those who had a mediastinal mass, 59% with WBC less than 30,000/microL, 63% with L1 morphology, 69% for T or TMy antigen expression, and 62% for those who lack the Ph chromosome. Fifteen patients (8%) had no unfavorable prognostic factors and have an estimated probability of survival at 5 years of 100% (95% confidence interval, 77% to 100%). This intensive chemotherapy regimen produces a high remission rate and a high proportion of durable remissions in adults with ALL. 相似文献
87.
Hendrix RM Lindner JL Benton FR Monteith SC Tuchscherer MA Gray GC Gaydos JC 《Emerging infectious diseases》1999,5(6):798-801
In May 1997, a large, persistent epidemic of adenovirus type 4-associated acute respiratory disease began at Fort Jackson, South Carolina, the largest army basic training center. The epidemic lasted until December and declined when vaccine administration resumed. More than 1,000 male and female trainees were hospitalized; 66.1% of those hospitalized had an adenovirus type 4 isolate. 相似文献
88.
89.
魔芋精粉的降血糖作用 总被引:6,自引:0,他引:6
目的:研究魔芋精粉的降糖作用。方法:以不同剂量魔芋精粉ig正常小鼠和四氧嘧啶糖尿病小鼠,连续10d后,葡萄糖氧化酶法测定正常小鼠的空腹血糖、糖耐量试验以及四氧嘧 啶糖尿病小鼠的血糖尿病小鼠的血糖,以放射免疫法测定血清胰岛素。结果:魔芋精粉有降低正常小鼠血糖作用,呈一定量效关系趋势;且具有改善小鼠糖耐量作用,能明显降低四氧嘧啶糖尿病小鼠血糖,但因清胰岛素水平无明显影响。结论:魔芋精粉可能是通过影响糖代 相似文献