全文获取类型
收费全文 | 23936篇 |
免费 | 1795篇 |
国内免费 | 144篇 |
专业分类
耳鼻咽喉 | 216篇 |
儿科学 | 851篇 |
妇产科学 | 659篇 |
基础医学 | 3255篇 |
口腔科学 | 375篇 |
临床医学 | 2500篇 |
内科学 | 4940篇 |
皮肤病学 | 590篇 |
神经病学 | 2687篇 |
特种医学 | 518篇 |
外科学 | 2186篇 |
综合类 | 155篇 |
一般理论 | 37篇 |
预防医学 | 3099篇 |
眼科学 | 295篇 |
药学 | 1473篇 |
1篇 | |
中国医学 | 42篇 |
肿瘤学 | 1996篇 |
出版年
2024年 | 21篇 |
2023年 | 346篇 |
2022年 | 579篇 |
2021年 | 1228篇 |
2020年 | 768篇 |
2019年 | 1013篇 |
2018年 | 1109篇 |
2017年 | 816篇 |
2016年 | 887篇 |
2015年 | 930篇 |
2014年 | 1218篇 |
2013年 | 1462篇 |
2012年 | 2142篇 |
2011年 | 2183篇 |
2010年 | 1133篇 |
2009年 | 953篇 |
2008年 | 1409篇 |
2007年 | 1364篇 |
2006年 | 1270篇 |
2005年 | 1086篇 |
2004年 | 928篇 |
2003年 | 798篇 |
2002年 | 685篇 |
2001年 | 124篇 |
2000年 | 115篇 |
1999年 | 106篇 |
1998年 | 107篇 |
1997年 | 93篇 |
1996年 | 73篇 |
1995年 | 84篇 |
1994年 | 53篇 |
1993年 | 56篇 |
1992年 | 58篇 |
1991年 | 54篇 |
1990年 | 41篇 |
1989年 | 42篇 |
1988年 | 62篇 |
1987年 | 51篇 |
1986年 | 46篇 |
1985年 | 35篇 |
1984年 | 48篇 |
1983年 | 27篇 |
1982年 | 28篇 |
1981年 | 35篇 |
1980年 | 23篇 |
1978年 | 17篇 |
1974年 | 20篇 |
1973年 | 15篇 |
1972年 | 22篇 |
1971年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
131.
Leigh J Beglinger Kevin Duff Sara Van Der Heiden Karen Parrott Douglas Langbehn Roger Gingrich 《Biology of blood and marrow transplantation》2006,12(9):928-935
Delirium has been associated with a high risk of mortality in medical patients. Despite the high incidence of delirium in patients who undergo hemapoietic stem cell transplantation (HSCT), delirium as a risk factor for death has not been examined in this population. Thirty adult patients undergoing HSCT who were admitted to the University of Iowa Blood and Marrow Transplantation Program inpatient unit were assessed prospectively from 1 to 2 weeks before transplantation, throughout their inpatient stay, and at 100 days after transplantation. The Delirium Rating Scale and Memorial Delirium Assessment Scale were used twice weekly during the inpatient period to assess delirium severity and occurence. Patients' self-reports of medical history, computerized medical records, and neuropsychological and psychiatric assessments were used to identify pretransplantation risk factors. The incidence of delirium (Delirium Rating Scale score >12 or Memorial Delirium Assessment Scale score >or=8) was 43% and occurred with highest frequency in the first 2 weeks after transplantion. The presence of delirium at any point during hospitalization after transplantation and transplant type (allogeneic) were highly predictive of mortality (p < .0005; odds ratios, 14.0 and 14.4). In conclusion, this study highlights the importance of monitoring for delirium during the acute recovery period after transplantation and suggests that early or even prophylactic treatment for delirium should be studied. Studies to determine the factors that connect delerium soon after transplantation to mortality are highly warranted. 相似文献
132.
Miksch S Lumsden A Guenther UP Foernzler D Christen-Zäch S Daugherty C Ramesar RK Lebwohl M Hohl D Neldner KH Lindpaintner K Richards RI Struk B 《Human mutation》2005,26(3):235-248
Pseudoxanthoma elasticum (PXE) is a systemic heritable disorder that affects the elastic tissue in the skin, eye, and cardiovascular system. Mutations in the ABCC6 gene cause PXE. We performed a mutation screen in ABCC6 using haplotype analysis in conjunction with direct sequencing to achieve a mutation detection rate of 97%. This screen consisted of 170 PXE chromosomes in 81 families, and detected 59 distinct mutations (32 missense, eight nonsense, and six likely splice-site point mutations; one small insertion; and seven small and five large deletions). Forty-three of these mutations are novel variants, which increases the total number of PXE mutations to 121. While most mutations are rare, three nonsense mutations, a splice donor site mutation, and the large deletion comprising exons 23-29 (c.2996_4208del) were identified as relatively frequent PXE mutations at 26%, 5%, 3.5%, 3%, and 11%, respectively. Chromosomal haplotyping with two proximal and two distal polymorphic markers flanking ABCC6 demonstrated that most chromosomes that carry these relatively frequent PXE mutations have related haplotypes specific for these mutations, which suggests that these chromosomes originate from single founder mutations. The types of mutations found support loss-of-function as the molecular mechanism for the PXE phenotype. In 76 of the 81 families, the affected individuals were either homozygous for the same mutation or compound heterozygous for two mutations. In the remaining five families with one uncovered mutation, affected showed allelic compound heterozygosity for the cosegregating PXE haplotype. This demonstrates pseudo-dominance as the relevant inheritance mechanism, since disease transmission to the next generation always requires one mutant allelic variant from each parent. In contrast to other previous clinical and molecular claims, our results show evidence only for recessive PXE. This has profound consequences for the genetic counseling of families with PXE. 相似文献
133.
Amanda B. Spurdle Sara Shankman Michele Ramsay 《American journal of medical genetics. Part A》1995,55(1):53-56
A molecular investigation of 16 Bantu-speaking Black XX true hermaphrodites was undertaken in an attempt to determine the cause of the disorder. Y-specific sequences, including sequences mapping to the sexdetermining region of the Y, were shown to be absent from lymphocyte tissue of all 16 patients tested. Y chromosome sequences were also absent from the ovarian and testicular components of both ovotestes of a single XX true hermaphrodite, thus excluding gonadal mosaicism involving Y chromosome sequences. Since there is evidence for Xp genes involved in testis determination/differentiation, uniparental disomy of the X chromosome was investigated in 14 XXTH families. Uniparental disomy was excluded in 12 of the 14 families, and isodisomy was excluded in the remaining two cases. © 1995 Wiley-Liss, Inc. 相似文献
134.
CD8+-T-Cell Response to Secreted and Nonsecreted Antigens Delivered by Recombinant Listeria monocytogenes during Secondary Infection
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Understanding how existing antivector immunity impacts live vaccine delivery systems is critical when the same vector system may be used to deliver different antigens. We addressed the impact of antivector immunity, elicited by immunization with attenuated actA-deficient Listeria monocytogenes, on the CD8(+)-T-cell response to a well-characterized lymphocytic choriomeningitis virus epitope, NP118-126, delivered by infection with recombinant L. monocytogenes. Challenges of immune mice with actA-deficient and with wild-type recombinant L. monocytogenes generated similar numbers of CD8(+) T cells specific for the NP118-126 epitope. High-dose immunization with actA-deficient L. monocytogenes resulted in substantial numbers of CD8(+) T cells specific for the L. monocytogenes LLO91-99 epitope in the effector and memory stages of the T-cell response. Challenge of these immune mice with recombinant L. monocytogenes resulted in rapid control of the infection and decreased CD8(+)-T-cell responses against both the secreted and nonsecreted form of the recombinant antigen compared to the response of na?ve mice. In contrast, mice immunized with a low dose of actA-deficient L. monocytogenes had approximately 10-fold fewer effector and memory T cells specific for LLO91-99 and a substantially higher CD8(+)-T-cell response against the recombinant antigen after challenge with recombinant L. monocytogenes. Although mice immunized with low-dose actA-deficient L. monocytogenes had a substantial recall response to LLO91-99, which reached the same levels by 5 to 7 days postchallenge as that in high-dose-immunized mice, they exhibited decreased ability to control L. monocytogenes replication. Thus, the level of antivector immunity impacts the control of infection and efficiency of priming responses against new antigens introduced with the same vector. 相似文献
135.
Pilar A Saiz Maria P Garcia-Portilla Celso Arango Blanca Morales Sara Martinez-Barrondo Victoria Alvarez Eliecer Coto Juan Fernandez Manuel Bousono Julio Bobes 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2006,(6):678-680
The aim of this study is to investigate the association between three polymorphisms of the interleukin-1 (IL-1) gene complex and schizophrenia. We genotyped 228 outpatients with schizophrenia (DSM-IV criteria) and 419 unrelated healthy controls. The following polymorphisms were analyzed: IL-1alpha -889 C/T, IL-1beta +3953 C/T, and IL-1RA (86 bp)n. No significant differences in genotype or in allelic distribution of the Il-1alpha, IL-1beta, and IL-1RA polymorphisms were found. Estimated haplotype frequencies were similar in both groups. Our data do not suggest that genetically determined changes in the IL-1 gene complex confer increased susceptibility for schizophrenia. 相似文献
136.
The bone marrow is the site of neutrophil production, a process that is regulated by the cytokine granulocyte colony‐stimulating factor (G‐CSF). Mature neutrophils are continually released into the circulation, with an estimated 10 11 neutrophils exiting the bone marrow daily under basal conditions. These leucocytes have a short half‐life in the blood of ~6·5 hr, and are subsequently destroyed in the spleen, liver and indeed the bone marrow itself. Additionally, mature neutrophils are retained in the bone marrow by the stromal cell‐derived factor (SDF‐1α)/chemokine (C‐X‐C motif) receptor 4 (CXCR4) chemokine axis and form the bone marrow reserve. Following infection or inflammatory insult, neutrophil release from the bone marrow reserve is substantially elevated and this process is mediated by the co‐ordinated actions of cytokines and chemokines. In this review we discuss the factors and molecular mechanisms regulating the neutrophil mobilization and consider the mechanisms and functional significance of neutrophil clearance via the bone marrow. 相似文献
137.
Deepika D'Cunha Burkardt Anna Zachariou Chey Loveday Clare L. Allen David J. Amor Anna Ardissone Siddharth Banka Alexia Bourgois Christine Coubes Cheryl Cytrynbaum Laurence Faivre Gerard Marion Rachel Horton Dieter Kotzot Guillermo Lay‐Son Melissa Lees Karen Low Ho‐Ming Luk Paul Mark Allyn McConkie‐Rosell Marie McDonald John Pappas Christophe Phillipe Deborah Shears Brian Skotko Fiona Stewart Helen Stewart I Karen. Temple Frederic T. Mau‐Them Ricardo A. Verdugo Rosanna Weksberg Yuri A. Zarate John M. Graham Katrina Tatton‐Brown 《American journal of medical genetics. Part A》2019,179(10):2049-2055
138.
Amene Tesfaye Alba Rodríguez-Nogales Sara Benedé Tahía D. Fernández Juan L. Paris Maria J. Rodriguez Isabel M. Jiménez-Sánchez Gador Bogas Cristobalina Mayorga María J. Torres María I. Montañez 《Allergy》2021,76(10):3183-3193
Background
Amoxicillin (AX) is nowadays the β-lactam that more frequently induces immediate allergic reactions. Nevertheless, diagnosis of AX allergy is occasionally challenging due to risky in vivo tests and non-optimal sensitivity of in vitro tests. AX requires protein haptenation to form multivalent conjugates with increased size to be immunogenic. Knowing adduct structural features for promoting effector cell activation would help to improve in vitro tests. We aimed to identify the optimal structural requirement in specific cellular degranulation to AX using well-precised nanoarchitectures of different lengths.Method
We constructed eight Bidendron Antigens (BiAns) based on polyethylene glycol (PEG) linkers of different lengths (600–12,000 Da), end-coupled with polyamidoamine dendrons that were terminally multi-functionalized with amoxicilloyl (AXO). In vitro IgE recognition was studied by competitive radioallergosorbent test (RAST) and antibody–nanoarchitecture complexes by transmission electron microscopy (TEM). Their allergenic activity was evaluated using bone marrow-derived mast cells (MCs) passively sensitized with mouse monoclonal IgE against AX and humanized RBL-2H3 cells sensitized with polyclonal antibodies from sera of AX-allergic patients.Results
All BiAns were recognized by AX-sIgE. Dose-dependent activation responses were observed in both cellular assays, only with longer structures, containing spacers in the range of PEG 6000–12,000 Da. Consistently, greater proportion of immunocomplexes and number of antibodies per complex for longer BiAns were visualized by TEM.Conclusions
BiAns are valuable platforms to study the mechanism of effector cell activation. These nanomolecular tools have demonstrated the importance of the adduct size to promote effector cell activation in AX allergy, which will impact for improving in vitro diagnostics.139.
140.
Bandana M. Chakraborty William H. Mueller Sandra K. Joos Craig L. Hanis Sara A. Barton William J. Schull 《American journal of human biology》1993,5(5):575-585
Upper and centralized body fat distribution is associated with non-insulin dependent diabetes mellitus (NIDDM). Few studies have focused on anthropometric characteristics of preadults from families in which there is a diabetic (NIDDM) proband. This study explores the prevalence of upper and centralized body fatness in Mexican American children from the Diabetes Alert study (1981–1983) in Starr County, Texas. Anthropometric data on 165 males and 224 females 9–19 years include measures of adiposity such as skinfold thicknesses and the body mass index (BMI), a measure of overweight. They show rates of obesity two to three times that of White children of comparable age and sex from National Health Surveys. In comparison with U.S. White subjects, Mexican American adults are shorter, have more adiposity and arm muscle mass and have sitting heights and body breadths at the mean of these dimensions for the U.S. population. Children from Diabetes Alert families show only marginal excess of severe obesity (> 95th percentile of BMI) when compared to the general population of children surveyed in Starr County schools. Girls from these families, but not boys, have excess fatness in the BMI compared to Mexican American children from the Hispanic Health and Nutrition Examination Survey (HHANES); suprailiac skinfold thicknesses are also greater in children of the Diabetes Alert study than in HHANES children. From 1972 through 1982, Mexican American children in South Texas showed an increase in average stature, weight, and the BMI. These data together suggest that excessive obesity exists and may be increasing in children in populations at risk for NIDDM. The prevention of NIDDM in the Mexican American population may be more effective if educational and promotional interventions include the school aged population. © 1993 Wiley-Liss, Inc. 相似文献