全文获取类型
收费全文 | 922篇 |
免费 | 30篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 54篇 |
妇产科学 | 19篇 |
基础医学 | 62篇 |
口腔科学 | 38篇 |
临床医学 | 136篇 |
内科学 | 211篇 |
皮肤病学 | 23篇 |
神经病学 | 5篇 |
特种医学 | 250篇 |
外科学 | 72篇 |
综合类 | 29篇 |
预防医学 | 32篇 |
眼科学 | 14篇 |
药学 | 36篇 |
肿瘤学 | 34篇 |
出版年
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 16篇 |
2014年 | 14篇 |
2013年 | 22篇 |
2012年 | 14篇 |
2011年 | 11篇 |
2010年 | 32篇 |
2009年 | 38篇 |
2008年 | 16篇 |
2007年 | 61篇 |
2006年 | 23篇 |
2005年 | 18篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 11篇 |
2001年 | 16篇 |
2000年 | 12篇 |
1999年 | 14篇 |
1998年 | 60篇 |
1997年 | 70篇 |
1996年 | 70篇 |
1995年 | 59篇 |
1994年 | 43篇 |
1993年 | 49篇 |
1992年 | 8篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 40篇 |
1988年 | 24篇 |
1987年 | 36篇 |
1986年 | 12篇 |
1985年 | 25篇 |
1984年 | 15篇 |
1983年 | 23篇 |
1982年 | 19篇 |
1981年 | 17篇 |
1980年 | 20篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 4篇 |
1975年 | 8篇 |
1969年 | 1篇 |
1966年 | 2篇 |
1948年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有1017条查询结果,搜索用时 0 毫秒
11.
Objective: To evaluate the incidence and severity of apnoea and bradycardia in hospitalized preterm infants following immunization at 2 months of age, and identify risk factors.
Methodology: A prospective study of 98 preterm infants, of gestational age 24–31 weeks, immunized at approximately 2 months post natal age with diphtheria-tetanus-whole cell pertussis vaccine (DTPw ) in the neonatal intensive care unit (NICU) at King George V Hospital Sydney. Half the infants also received Haemophilus influenzae type b conjugate vaccine (Hib) simultaneously. All infants were monitored for apnoea and bradycardia in the 24 h periods pre- and post immunization.
Results: Only one infant had apnoea and/or bradycardia pre-immunization compared with 17 post immunization. For 12 infants these events were brief, self-limiting and not associated with desaturations (oxygen saturation <90%). However, for five infants (30%) these events were associated with oxygen desaturation and two of these infants required supplemental oxygen. The group that had apnoea and/or bradycardia and the group that did not were not significantly different in terms of gestational age, birth weight and other variables. Infants who received Hib together with DTPw were less likely to have apnoea and/or bradycardia than those given DTPw alone.
Conclusion: When considering immunization for preterm infants, the benefits of early immunization must be balanced against the risk of apnoea and bradycardia. We recommend that the cardio-respiratory function of hospitalized infants born at less than 31 weeks gestation be monitored for 48 h post immunization. 相似文献
Methodology: A prospective study of 98 preterm infants, of gestational age 24–31 weeks, immunized at approximately 2 months post natal age with diphtheria-tetanus-whole cell pertussis vaccine (DTP
Results: Only one infant had apnoea and/or bradycardia pre-immunization compared with 17 post immunization. For 12 infants these events were brief, self-limiting and not associated with desaturations (oxygen saturation <90%). However, for five infants (30%) these events were associated with oxygen desaturation and two of these infants required supplemental oxygen. The group that had apnoea and/or bradycardia and the group that did not were not significantly different in terms of gestational age, birth weight and other variables. Infants who received Hib together with DTP
Conclusion: When considering immunization for preterm infants, the benefits of early immunization must be balanced against the risk of apnoea and bradycardia. We recommend that the cardio-respiratory function of hospitalized infants born at less than 31 weeks gestation be monitored for 48 h post immunization. 相似文献
12.
13.
Splenic lymphangiomatosis in children 总被引:14,自引:0,他引:14
14.
Human acute leukemia cell line with the t(4;11) chromosomal rearrangement exhibits B lineage and monocytic characteristics 总被引:18,自引:8,他引:18
A cell line, designated RS4;11, was established from the bone marrow of a patient in relapse with an acute leukemia that was characterized by the t(4;11) chromosomal abnormality. The cell line and the patient's fresh leukemic cells both had the t(4;11)(q21;q23) and an isochromosome for the long arm of No. 7. Morphologically, all cells were lymphoid in appearance. Ultrastructurally and cytochemically, approximately 30% of the cells possessed myeloid features. The cells were strongly positive for terminal deoxynucleotidyl transferase. They were HLA-DR positive and expressed surface antigens characteristic for B lineage cells, including those detected by anti-B4, BA-1, BA-2, and PI153/3. Immunoglobulin gene analysis revealed rearrangements of the heavy chain and kappa chain genes. The cells lacked the common acute lymphoblastic leukemia antigen and antigenic markers characteristic of T lineage cells. The cells reacted with the myeloid antibody 1G10 but not with other myeloid monoclonal antibodies. Treatment with 12-O-tetradecanoyl- phorbol-13-acetate induced a monocyte-like phenotype demonstrated by cytochemical, functional, immunologic, and electron microscopic studies. The expression of markers of both early lymphoid and early myeloid cells represents an unusual phenotype and suggests that RS4;11 represents a cell with dual lineage capabilities. To our knowledge, RS4;11 is the first cell line established from t(4;11)-associated acute leukemia. 相似文献
15.
锌酞菁脂质体光动力作用引起小鼠肿瘤的细胞程序性死亡 总被引:3,自引:1,他引:3
电镜观察了锌酞菁脂质体光动力作用引起小鼠MS-2纤维肉瘤的形态学变化。发现其作用很强,并对肿瘤细胞有明显的直接影响。肿瘤细胞的结构表现出明显的程序性细胞死亡(apoptosis,programmedceldeath)的特点:胞核染色质凝聚边集、核固缩、核破裂、染色质凝块流失、胞质内吞噬现象、胞膜表面肿胀粗钝的胞突形成、细胞碎裂等。加深了对锌酞菁脂质体光敏作用机理的认识,但其详细的发生机制和调节途径有待阐明。 相似文献
16.
Leonidas JC; Berdon WE; Valderrama E; Neveling U; Schuval S; Weiss SJ; Hilfer C; Godine L 《Radiology》1996,198(2):377
17.
18.
Templeton AW; Johnson JA; Anderson WH; Cook LT; Dwyer SJ d; Preston DF; Lee KR; Rosenthal SJ; Batnitzky S; Levine E 《Radiology》1984,151(2):527-528
The increasing use of digitally formatted imaging systems requires high-quality interactive gray-scale computer raster graphics systems for the management, display, and analog film recording of digital image and alphanumeric information. These systems are a combination of computer hardware and software and implement a set of graphics protocols. This paper describes a set of interactive graphics protocols that has been developed for clinical use. 相似文献
19.
Suzan?DijkinkEmail author Pieta?Krijnen Aglaia?Hage Gwendolyn?M.?Van der?Wilden George?Kasotakis Dennis?den?Hartog Ali?Salim J.?Carel?Goslings Frank?W.?Bloemers Steven?J.?Rhemrev David?R.?King George?C.?Velmahos Inger?B.?Schipper 《World journal of surgery》2018,42(11):3608-3615
Introduction
The incidence and nature of penetrating injuries differ between countries. The aim of this study was to analyze characteristics and clinical outcomes of patients with penetrating injuries treated at urban Level-1 trauma centers in the USA (USTC) and the Netherlands (NLTC).Methods
In this retrospective cohort study, 1331 adult patients (470 from five NLTC and 861 from three USTC) with truncal penetrating injuries admitted between July 2011 and December 2014 were included. In-hospital mortality was the primary outcome. Outcome comparisons were adjusted for differences in population characteristics in multivariable analyses.Results
In USTC, gunshot wound injuries (36.1 vs. 17.4%, p?<?0.001) and assaults were more frequent (91.2 vs. 77.7%, p?<?0.001). ISS was higher in USTC, but the Revised Trauma Score (RTS) was comparable. In-hospital mortality was similar (5.0 vs. 3.6% in NLTC, p?=?0.25). The adjusted odds ratio for mortality in USTC compared to NLTC was 0.95 (95% confidence interval 0.35–2.54). Hospital stay length of stay was shorter in USTC (difference 0.17 days, 95% CI ?0.29 to ?0.05, p?=?0.005), ICU admission rate was comparable (OR 0.96, 95% CI 0.71–1.31, p?=?0.80), and ICU length of stay was longer in USTC (difference of 0.39 days, 95% CI 0.18–0.60, p?<?0.0001). More USTC patients were discharged to home (86.9 vs. 80.6%, p?<?0.001). Readmission rates were similar (5.6 vs. 3.8%, p?=?0.17).Conclusion
Despite the higher incidence of penetrating trauma, particularly firearm-related injuries, and higher hospital volumes in the USTC compared to the NLTC, the in-hospital mortality was similar. In this study, outcome of care was not significantly influenced by differences in incidence of firearm-related injuries.20.
Digital imaging of the chest 总被引:4,自引:0,他引:4
Fraser RG; Sanders C; Barnes GT; MacMahon H; Giger ML; Doi K; Templeton AW; Cox GG; Dwyer SJ d; Merritt CR 《Radiology》1989,171(2):297-307
During the past several years, image acquisition in nuclear medicine, computed tomography, ultrasonography, subtraction angiography, and magnetic resonance has been by digitization. Despite these advances, research in the development of digital imaging in conventional radiography has lagged behind. Although studies with a variety of digital techniques have been carried out on several fronts, we still do not possess a method that has captured the imagination of the majority of radiologists and other physicians to a point where it could replace conventional screen-film imaging. This article reviews the current status and general principles of the technology, focusing on the four digital radiographic techniques that have shown the greatest promise - film digitization, an image intensifier - based system, photostimulable phosphor plates, and a scanned projection system. The physical aspects of each of the four systems and the clinical results that have been reported to date, as well as the advantages and disadvantages of each system, are presented. 相似文献