全文获取类型
收费全文 | 1026篇 |
免费 | 75篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 81篇 |
妇产科学 | 8篇 |
基础医学 | 88篇 |
口腔科学 | 26篇 |
临床医学 | 71篇 |
内科学 | 182篇 |
皮肤病学 | 27篇 |
神经病学 | 21篇 |
特种医学 | 132篇 |
外科学 | 118篇 |
综合类 | 134篇 |
预防医学 | 67篇 |
眼科学 | 4篇 |
药学 | 55篇 |
中国医学 | 39篇 |
肿瘤学 | 63篇 |
出版年
2023年 | 8篇 |
2022年 | 15篇 |
2021年 | 23篇 |
2020年 | 20篇 |
2019年 | 15篇 |
2018年 | 19篇 |
2017年 | 14篇 |
2016年 | 19篇 |
2015年 | 27篇 |
2014年 | 42篇 |
2013年 | 37篇 |
2012年 | 44篇 |
2011年 | 48篇 |
2010年 | 72篇 |
2009年 | 60篇 |
2008年 | 27篇 |
2007年 | 32篇 |
2006年 | 41篇 |
2005年 | 28篇 |
2004年 | 15篇 |
2003年 | 23篇 |
2002年 | 11篇 |
2001年 | 13篇 |
2000年 | 9篇 |
1999年 | 19篇 |
1998年 | 45篇 |
1997年 | 59篇 |
1996年 | 51篇 |
1995年 | 38篇 |
1994年 | 32篇 |
1993年 | 31篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 23篇 |
1988年 | 19篇 |
1987年 | 17篇 |
1986年 | 16篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 2篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 11篇 |
1979年 | 3篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1958年 | 4篇 |
1957年 | 2篇 |
排序方式: 共有1119条查询结果,搜索用时 15 毫秒
991.
992.
Guidelines for blood utilization review 总被引:11,自引:0,他引:11
L Stehling ; NL Luban ; KC Anderson ; MH Sayers ; A Long ; S Attar ; SF Leitman ; SA Gould ; MS Kruskall ; LT Goodnough ; et al. 《Transfusion》1994,34(5):438-448
Hospitals are required by accrediting agencies to perform blood utilization review. Specific areas that must be addressed are the ordering, distribution, handling, dispensing, and administration of blood components. Monitoring the effects of transfusion on patients is also required. The format of the review process and the criteria for appropriate blood utilization must be developed by each institution. This article provides examples of areas that can be reviewed and procedures that may be used. However, the suggested laboratory values must not be interpreted as defining indications or criteria for transfusion. Each transfusion committee, or its equivalent, is responsible for developing its own institutional blood utilization procedures and audit criteria. Review and approval by the medical staff prior to implementation are essential. The procedures must also be reviewed and revised on a regular basis. 相似文献
993.
Griffin JD; Sabbath KD; Herrmann F; Larcom P; Nichols K; Kornacki M; Levine H; Cannistra SA 《Blood》1985,66(4):788-795
Expression of HLA-DR surface antigens by granulocyte/monocyte colony- forming cells (CFU-GM) may be important in the regulation of proliferation of these cells. Using immunological techniques to enrich for progenitor cells, we investigated the expression of HLA-DR in subsets of CFU-GM. "Early" (day 14) CFU-GM express higher levels of HLA- DR than do "late" (day 7) CFU-GM. Among late CFU-GM, cells destined to form monocyte (alpha-naphthyl acetate esterase-positive) colonies express higher levels of HLA-DR than do CFU-GM destined to form granulocyte (chloroacetate esterase-positive) colonies. Because high- level expression of DR antigen was a marker for monocyte differentiation, we examined several lymphokines for their effects on both DR expression and in vitro commitment to monocyte differentiation by myeloid precursor cells. DR antigen density could be increased by more than twofold over 48 hours upon exposure to gamma-interferon (gamma-IFN), whereas colony-stimulating factors had no effect. This was associated with a dose-dependent inhibition of total CFU-GM number, and a relative, but not absolute, increase in the ratio of monocyte colonies to granulocyte colonies. Similarly, in day 7 suspension cultures of purified myeloid precursor cells, gamma-IFN inhibited cell proliferation and increased the ratio of monocytes to granulocytes. Thus, despite the induction of high levels of HLA-DR antigen on precursor cells (a marker of monocyte commitment), the dominant in vitro effect of gamma-IFN was inhibition of granulocyte differentiation. 相似文献
994.
大鼠原位肝移植模型建立方法的若干问题探讨 总被引:2,自引:0,他引:2
目的探讨建立大鼠原位肝移植模型的方法与技术。方法用改进的二袖套法行100例Lewis→BN大鼠原位肝移植,术中门静脉、肝下下腔静脉用袖套法吻合,肝上下腔静脉用缝合法吻合,胆管内支架法完成胆道重建。结果供体手术时间(30.9±5.0)min,供肝修整时间(10.0±3.0)min,受体手术时间(50.0±5.5)min,无肝期为(23.0±2.5)min。手术成功率为92%(术后存活2 d以上),1周存活率为87%,1个月存活率为84%。结论通过提高手术技巧,熟悉各种并发症的原因和预防处理措施,可以减少并发症的发生,提高手术成功率,延长大鼠术后存活时间。 相似文献
995.
996.
OBJECTIVES: To determine the usefulness of electrocardiography (ECG) and chest radiography (CXR) in evaluation of patients referred to the pediatric cardiologist for the evaluation of heart murmur or chest pain. DESIGN: In this prospective study, 106 consecutive outpatients were categorized with no heart disease, possible heart disease, or definite heart disease based on history and physical examination; they then underwent ECG and CXR. Studies were reviewed and the examining cardiologist could change the diagnosis and order an echocardiogram. SETTING: Academic pediatric cardiology practice. RESULTS: In patients thought to have no heart disease, the diagnosis was changed to definite heart disease in four solely on the basis of abnormal CXR or ECG. In 25 patients thought to have possible heart disease, the diagnosis was changed to no heart disease (7) or definite heart disease (5) after review of the CXR and ECG. All 25 patients diagnosed with definite heart disease had this confirmed by abnormal CXR (2), ECG (3), both abnormal CXR and ECG, or echocardiogram (18). CONCLUSIONS: ECG and CXR helped diagnose heart disease in four patients thought to have no heart disease, helped to rule out lesions in seven patients with possible heart disease, helped diagnose heart disease in five patients thought to have possible heart disease, and helped confirm heart disease in nine patients. In these days of cost containment, routine ECG and CXR continue to be valuable tools for the pediatric cardiologist in evaluation of patients with heart murmurs or chest pain. 相似文献
997.
998.
Middle-latency somatosensory evoked potentials (MLSEPs) were recorded from 19 scalp electrodes in ten male patients with the fragile X (fraX) syndrome and nine normal controls. One fraX patient was found presenting the so-called “giant” MLSEPs with an amplitude of N60 of about 60 μV and of 40 μV after stimulation of the right and left median nerves, respectively. Tapping of the right hand, in the same patient, induced the appearance of left parietal evoked EEG spikes. These findings further support the already suggested similarity between the epileptic picture of several fraX patients with that of the benign childhood epilepsy with centrotemporal spikes. Color mapping of the MLSEPs recorded in the remaining nine patients, when compared with the control group, showed an abnormally large N30 over the frontal regions, together with an increase in amplitude of P27, over the parietal areas, and of N60 and P100 which also presented abnormal field distributions, being represented preferentially over the frontal regions. These data could suggest the existence of a cortical dysfunction mostly involving the frontal lobes (supplementary motor area, in particular) in the fraX syndrome which could support many behavioral changes usually observed in these patients.
Résumé
Les potentiels évoqués somesthésiques à latence moyenne (MLSEPs) du nerf médian ont été enregistrés avec 19 électrodes chez dix sujets avec le syndrome du chromosome X fragile (fraX) et neuf sujets normaux. Nous avons observé un sujet avec fraX et des MLSEPs géants et une amplitude de l'onde N60 de 60 μV après stimulation du nerf médian droit et de 40 μV après stimulation gauche. Après le toucher de la main gauche, chez le même sujet, on a observé l'apparition de pointes épileptiques pariétales à l'EEG. Ces résultats confirment l'hypothèse déjà proposée de la similitude entre l'épilepsie présentée par quelques sujets avec fraX et l'épilepsie bénigne de l'enfant avec pointes centrotemporales. La cartographie des MLSEPs obtenue chez les neuf autres sujets et confrontée à celle du groupe contrôle a mis en évidence une onde N30 avec amplitude anormalement augmentée sur les régions frontales, une augmentation de l'amplitude de P27 sur les régions pariétales, et de N60 et P100, qui montraient aussi une anormalité de la distribution topographique ; en effet, elles étaient mieux représentées sur les régions frontales. Ces données peuvent indiquer l'existence d'un dysfonctionnement des lobes frontaux (en particulier de l'aire motrice supplémentaire), dans le syndrome du chromosome X fragile, qui peut se corréler à plusieurs modifications du comportement généralement observées chez ces patients. 相似文献999.
Knowledge and awareness of risk factors for cardiovascular disease among Canadians 55 to 74 years of age: results from the Canadian Heart Health Surveys, 1986-1992 总被引:2,自引:1,他引:1 下载免费PDF全文
1000.