全文获取类型
收费全文 | 1252篇 |
免费 | 62篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 71篇 |
妇产科学 | 8篇 |
基础医学 | 141篇 |
口腔科学 | 25篇 |
临床医学 | 147篇 |
内科学 | 292篇 |
皮肤病学 | 52篇 |
神经病学 | 29篇 |
特种医学 | 303篇 |
外科学 | 64篇 |
综合类 | 30篇 |
预防医学 | 46篇 |
眼科学 | 6篇 |
药学 | 76篇 |
中国医学 | 9篇 |
肿瘤学 | 71篇 |
出版年
2023年 | 8篇 |
2022年 | 8篇 |
2021年 | 14篇 |
2020年 | 12篇 |
2019年 | 9篇 |
2018年 | 18篇 |
2017年 | 6篇 |
2016年 | 10篇 |
2015年 | 15篇 |
2014年 | 21篇 |
2013年 | 49篇 |
2012年 | 34篇 |
2011年 | 24篇 |
2010年 | 42篇 |
2009年 | 59篇 |
2008年 | 23篇 |
2007年 | 58篇 |
2006年 | 24篇 |
2005年 | 27篇 |
2004年 | 17篇 |
2003年 | 20篇 |
2002年 | 21篇 |
2001年 | 15篇 |
2000年 | 17篇 |
1999年 | 22篇 |
1998年 | 71篇 |
1997年 | 81篇 |
1996年 | 101篇 |
1995年 | 64篇 |
1994年 | 58篇 |
1993年 | 52篇 |
1992年 | 16篇 |
1991年 | 15篇 |
1990年 | 21篇 |
1989年 | 39篇 |
1988年 | 38篇 |
1987年 | 35篇 |
1986年 | 46篇 |
1985年 | 41篇 |
1984年 | 9篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 12篇 |
1977年 | 9篇 |
1976年 | 13篇 |
1975年 | 14篇 |
1973年 | 2篇 |
排序方式: 共有1371条查询结果,搜索用时 15 毫秒
81.
82.
Jagtap DD Mahale SD Mishra AK Nandedkar TD Iyer KS 《The Journal of endocrinology》2002,172(2):311-320
An in-depth study of the L2beta long-loop region of human chorionic gonadotrophin (hCG), earlier identified to be a conformational bioneutralization epitope and receptor-binding site of the hormone, was carried out. The linear 38-57 hCGbeta peptide and the corresponding cyclic disulphide peptide were synthesized and antipeptide antibodies developed. Binding studies with antibodies to the linear peptide, and with hCGbeta, hCG and human LH suggest that part of the region is buried at the alpha/beta interface and part exposed in hCG. Observation of the surface exposure of residues 47-53 from the crystal structure of hCG was confirmed by epitope mapping studies of the region. The region is not unique to hCG as a majority of the antibodies to both the linear and cyclic peptides did not exhibit the required specificity. Competitive inhibition studies with the linear and cyclic peptides failed to show inhibition of radiolabelled hCG binding to its receptors. However, both the antipeptide antibodies were able to bioneutralize the hormone in an in vivo assay. Taken together, these results seem to indicate that the L2beta long-loop region is not a receptor-binding site of hCG but spatially close to it. 相似文献
83.
Jagtap SA Chincholi S Taneja PK Ismail ND Ram S Sarvagod SB Dongre N Desai A 《Journal of the Indian Medical Association》2003,101(12):764, 766, 727
Valdecoxib, a COX-2 inhibitor, has recently been introduced as a gel formulation. The present study was conducted to evaluate the efficacy, safety and tolerability of valdecoxib gel in adult patients with painful inflammatory joint conditions. The present study was a 10-day prospective, open, multicentric (6 centres) trial. Patients with clinical and radiological diagnosis of painful inflammatory joint conditions were treated with valdecoxib gel (1%). Efficacy was assessed by visual analogue scale (VAS), patient's and physician's global assessment of pain relief. Grading of associated clinical manifestations such as stiffness, swelling, tenderness and restriction of mobility was done. Tolerability and safety was assessed by physical examination, laboratory parameters and evaluation of adverse events. There was a statistically significant decrease in the mean pain visual analogue score (p<0.05). Onset of pain relief was within 15 minutes. There was a reduction of 58.8%, 57.2%, 65.4% and 60.2% in mean scores of stiffness, swelling, tenderness and mobility respectively from the baseline which was statistically significant. The laboratory values were within normal limits. The drug was well tolerated. There was no report of any hypersensitivity reaction. This study confirms that valdecoxib gel (1%) is an effective and safe option for the management of painful inflammatory joint conditions. 相似文献
84.
OBJECTIVE: To determine whether children's food consumption is increased by the size of the group of children in which they are eating. DESIGN: Crossover study. SETTING: University based preschool. PARTICIPANTS: 54 children, aged 2.5-6.5 years. INTERVENTIONS: Each child ate a standardised snack in a group of three children, and in a group of nine children. MAIN OUTCOME MEASURES: Amount each individual child consumed, in grams. RESULTS: Amount eaten and snack duration were correlated (r = 0.71). The association between group size and amount eaten differed in the short (<11.4 min) versus the long (> or =11.4 min) snacks (p = 0.02 for the interaction between group size and snack duration). During short snacks, there was no effect of group size on amount eaten (16.7 (SD 11) g eaten in small groups vs 15.1 (6.6) g eaten in large groups, p = 0.42). During long snacks, large group size increased the amount eaten (34.5 (16) vs 26.5 (13.8), p = 0.02). The group size effect was partially explained by a shorter latency to begin eating, a faster eating rate and reduced social interaction in larger groups. CONCLUSIONS: Children consumed 30% more food when eating in a group of nine children than when eating in a group of three children during longer snacks. Social facilitation of food consumption operates in preschool-aged children. The group size effect merits consideration in creating eating behaviour interventions. 相似文献
85.
86.
87.
假肿瘤性胰腺炎的CT表现 总被引:8,自引:0,他引:8
目的 提高对慢性假肿瘤性胰腺炎的影像学特征的认识,材料与方法 回顾性分析12例经临床、病理诊断的假肿瘤性胰腺炎的特点,结果 12例均见胰产质肿块形成,大多为类圆形,直径为2.5~4cm,边缘规则,肿块较均质,如肿块较大,则密度不均,中心坏死,边缘不规则,8例肿块内有钙化,CT增强扫描肿块大多呈明显强化,11例位于胰头部,1例位于胰体部,7例B超呈低回声,5例为不均匀回声,结论 假肿瘤性胰腺炎与胰腺 相似文献
88.
89.
Blood flows and recirculations with standard and reversed direction of lines were measured by chemical (urea and creatinine) and ultrasound dilution (saline) methods in 47 chronic hemodialysis patients. Thirty-seven patients had 47 dual-lumen, central vein (CV) catheters: 32 were PermCath (Quinton Instruments Company, Seattle, WA), 6 were Access Cath (MEDCOMP, Harleysville, PA), 3 were Soft Cell PC (Vas Cath, Mississauga, Ontario, Canada) and 6 were SNIJ (experimental catheters). Three of these last catheters had the tip staggered 7 mm, and three had flush tips; PermCath, Access Cath, and Soft Cell PC catheters have the tips staggered 23 to 25 mm. Forty-six catheters were implanted into the superior vena cava/right atrium, and one catheter was implanted through the left saphenous vein into the left iliac vein. The catheters were studied 1 to 31 months after implantation (median, 3.0 months). Ten patients with arteriovenous (AV) graft access were also studied. The stop-flow method was used in catheter dialysis, and the slow-flow method was used to calculate recirculations in AV access dialysis with samples for systemic blood concentrations taken from arterial line both before and after samples from the arterial and venous lines. At 500 mL/min pump speed, actual blood flow was 436+/-18 mL/min (mean+/-SD; range, 407 to 464 mL/min) with standard direction of catheter lines. At 500 mL/min pump speed, the arterial chamber pressure was -330+/-48 mm Hg (mean+/-SD; range, -380 to -225 mm Hg, and the venous chamber pressure was 259+/-48 mm Hg (mean+/-SD; range, 140 to 310 mm Hg). Arterial chamber pressure was less negative, and venous chamber pressure was less positive with SNIJ catheters, which had larger internal diameter (2.1 mm) compared with the other catheters (2.0 mm). Recirculation varied with the catheter design and the location of the catheter tip. In the catheters with tip staggered more than 20 mm and with standard line connection at pump speeds of 50 mL/min and 500 mL/min, recirculations were approximately 1 % and 5%, respectively, when measured by the chemical method. In the same catheters with reversed lines, the recirculations were approximately 5% and 27%, respectively. Inflow failure catheters with reversed lines had similar recirculation values to those of well-functioning catheters with reversed lines. In catheters with tips staggered 7 mm, and with standard connection of lines, recirculations were approximately 3% and 8%, respectively, at pump speeds of 50 and 500 mL/min. With reversed lines, at the same pump speeds, the values were 7% and 12%, respectively. In flush-tip catheters, the recirculation was higher at a 50 mL/min pump speed (approximately 17%) than at a pump speed of 500 mL/min (approximately 13%). The ultrasound dilution method usually gave lower values than the chemical methods, most likely because of overestimation of recirculation by chemical methods. At least triplicate measurements are needed because single measurements by the ultrasound dilution method are associated with substantial variation. We conclude that both currently used methods (stop flow and slow flow) of taking systemic samples for measurements of recirculation by chemical methods are flawed because of disequilibrium and recirculation at low flow. 相似文献
90.