全文获取类型
收费全文 | 7601篇 |
免费 | 569篇 |
国内免费 | 111篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 420篇 |
妇产科学 | 374篇 |
基础医学 | 471篇 |
口腔科学 | 27篇 |
临床医学 | 2203篇 |
内科学 | 1632篇 |
皮肤病学 | 15篇 |
神经病学 | 47篇 |
特种医学 | 94篇 |
外科学 | 1098篇 |
综合类 | 940篇 |
预防医学 | 399篇 |
眼科学 | 6篇 |
药学 | 324篇 |
7篇 | |
中国医学 | 75篇 |
肿瘤学 | 135篇 |
出版年
2024年 | 10篇 |
2023年 | 219篇 |
2022年 | 203篇 |
2021年 | 433篇 |
2020年 | 330篇 |
2019年 | 301篇 |
2018年 | 281篇 |
2017年 | 339篇 |
2016年 | 301篇 |
2015年 | 302篇 |
2014年 | 522篇 |
2013年 | 533篇 |
2012年 | 401篇 |
2011年 | 442篇 |
2010年 | 343篇 |
2009年 | 359篇 |
2008年 | 322篇 |
2007年 | 367篇 |
2006年 | 283篇 |
2005年 | 267篇 |
2004年 | 222篇 |
2003年 | 187篇 |
2002年 | 179篇 |
2001年 | 163篇 |
2000年 | 145篇 |
1999年 | 111篇 |
1998年 | 96篇 |
1997年 | 77篇 |
1996年 | 70篇 |
1995年 | 65篇 |
1994年 | 65篇 |
1993年 | 41篇 |
1992年 | 36篇 |
1991年 | 38篇 |
1990年 | 15篇 |
1989年 | 27篇 |
1988年 | 21篇 |
1987年 | 12篇 |
1986年 | 16篇 |
1985年 | 15篇 |
1984年 | 11篇 |
1983年 | 10篇 |
1982年 | 16篇 |
1981年 | 13篇 |
1980年 | 14篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 10篇 |
1973年 | 6篇 |
排序方式: 共有8281条查询结果,搜索用时 15 毫秒
1.
2.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion. 相似文献
3.
Aaron Pitzele Mohammad Rahimi Eric Armbrecht 《The journal of maternal-fetal & neonatal medicine》2015,28(15):1770-1773
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion. 相似文献
4.
Bernard Natukunda Grace Ndeezi Lay See Er Francis Bajunirwe Gayle Teramura Meghan Delaney 《ISBT科学丛刊》2019,14(4):366-373
5.
6.
《Burns : journal of the International Society for Burn Injuries》2021,47(5):1038-1044
IntroductionAlthough blood transfusion is common in burns, data are lacking in appropriate transfusion thresholds. It has been reported that a restrictive blood transfusion policy decreases blood utilization and improves outcomes in critically ill adults, but the impact of a restrictive blood transfusion policy in burn patients is unclear. We decided to investigate the outcome of decreasing the blood transfusion threshold.Material and methodsEighty patients with TBSA > 20% who met our inclusion criteria were included. They were randomly divided into control and intervention groups. The intervention group received packed cells only when Hemoglobin declined to less than 8 g/dL at routine laboratory evaluations. While the control group received packed-cell when hemoglobin was declined to less than 10 g/dl. The total number of the received packed cell before, during and after any surgical procedure was recorded. The outcome was measured by the evaluation of the infection rate and other complications.ResultThe mean hemoglobin level before transfusion was 7.7 ± 0.4 g/dL in the restrictive group and 8.8 ± 0.7 g/dL in the liberal group. The mean number of RBC unit transfusion per patient in the restrictive group was significantly lower than the traditional group (3.28 ± 2.2 units vs. 5.9 ± 3.7 units) (p-value = 0.006). The total number of RBC transfused units varied significantly between the two groups (p-value = 0.014). The number of transfused RBC units outside the operation room showed a significant difference between groups (restrictive: 2.8 ± 1.4 units vs. liberal: 4.4 ± 2.6 units) (p = 0.004). We did not find any significant difference in mortality rate or other outcome measures between groups.ConclusionApplying the restrictive transfusion strategy in thermal burn patients who are highly prone to all kinds of infection, does not adversely impact the patient outcome, and results in significant cost savings to the institution and lower rate of infection. We conclude that the restrictive transfusion practice during burn excision and grafting is well tolerated and effective in reducing the number of transfusions without increasing complications.Clinical Trial Registration ReferenceIRCT20190209042660N1. 相似文献
7.
8.
9.
10.
不同输血方式对肺鳞癌患者围术期TNF—α和IL—lO的影响 总被引:2,自引:0,他引:2
[目的]探讨同种输血和自体输血对肺鳞癌患者围术期肿瘤坏死因子-α(TNF-α)和白细胞介素—10(IL—10)的影响和相互关系。[方法]2001年1月至2003年1月对31例肺鳞癌患者行肺癌根治术,将其分为两组,同种输血组(A组)17例,自体输血组14例(B组)。测定两组围术期血清中TNF-α和IL—10的浓度。[结果]A组输血后d1与输血前相比血清中TNF-α、IL-10浓度增高,以IL—10变化尤为明显,输血后d5TNF-α降低并接近输血前的水平,明显低于B组,IL—10仍明显高于输血前的水平。B组中不同时问IL—10无显著变化,TNF-α于ds明显高于输血前。[结论]肺鳞癌患者围术期同种输血后血清中TNF-α降低与IL—10升高有关,IL—10升高可能是同种输血后免疫抑制的重要原因。自体输血可减轻或去除这一作用。 相似文献