全文获取类型
收费全文 | 2936篇 |
免费 | 328篇 |
出版年
2023年 | 7篇 |
2022年 | 30篇 |
2021年 | 48篇 |
2020年 | 40篇 |
2019年 | 46篇 |
2018年 | 90篇 |
2017年 | 74篇 |
2016年 | 86篇 |
2015年 | 150篇 |
2014年 | 139篇 |
2013年 | 187篇 |
2012年 | 204篇 |
2011年 | 184篇 |
2010年 | 136篇 |
2009年 | 105篇 |
2008年 | 157篇 |
2007年 | 134篇 |
2006年 | 137篇 |
2005年 | 124篇 |
2004年 | 111篇 |
2003年 | 113篇 |
2002年 | 113篇 |
2001年 | 95篇 |
2000年 | 71篇 |
1999年 | 62篇 |
1998年 | 36篇 |
1997年 | 29篇 |
1996年 | 26篇 |
1995年 | 27篇 |
1994年 | 29篇 |
1993年 | 17篇 |
1992年 | 44篇 |
1991年 | 42篇 |
1990年 | 35篇 |
1989年 | 32篇 |
1988年 | 31篇 |
1987年 | 27篇 |
1986年 | 49篇 |
1985年 | 29篇 |
1984年 | 21篇 |
1983年 | 17篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 16篇 |
1975年 | 7篇 |
1974年 | 12篇 |
1973年 | 18篇 |
1969年 | 6篇 |
排序方式: 共有3264条查询结果,搜索用时 15 毫秒
991.
992.
Moreno Paolini Luca Valgimigli Emanuela Marchesi Silvia Trespidi Gian Franco Pedulli 《Free radical research》2013,47(5):503-508
Assessment of oxidative stress status (OSS) in human tissues is still troublesome. Using an innovative EPR-radical-probe we successfully measured the instantaneous concentration of ROS directly in peripheral blood of athletes and normally active workers during 60 min controlled exercise. The probe employed was bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decandioate, which quantitatively and instantaneously reacts with oxygen-centered radicals (including superoxide) to yield the parent nitroxide, which is sufficiently persistent to be measured by EPR. Our measurements suggest that while at rest normally active individuals may benefit more from antioxidant supplementation than athletes; conversely, during exercise athletes may benefit more from supplementation. Our method allows reliable, quick, and non-invasive quantitative determination of OSS in human peripheral blood. 相似文献
993.
Pint lincRNA connects the p53 pathway with epigenetic silencing by the Polycomb repressive complex 2
994.
995.
996.
Maria Moreno‐Villanueva Alexander Bürkle Inge Petersen Vilhelm A. Bohr Kaare Christensen Tinna Stevnsner 《Aging cell》2013,12(1):58-66
Exogenous and endogenous damage to DNA is constantly challenging the stability of our genome. This DNA damage increase the frequency of errors in DNA replication, thus causing point mutations or chromosomal rearrangements and has been implicated in aging, cancer, and neurodegenerative diseases. Therefore, efficient DNA repair is vital for the maintenance of genome stability. The general notion has been that DNA repair capacity decreases with age although there are conflicting results. Here, we focused on potential age‐associated changes in DNA damage response and the capacities of repairing DNA single‐strand breaks (SSBs) and double‐strand breaks (DSBs) in human peripheral blood mononuclear cells (PBMCs). Of these lesions, DSBs are the least frequent but the most dangerous for cells. We have measured the level of endogenous SSBs, SSB repair capacity, γ‐H2AX response, and DSB repair capacity in a study population consisting of 216 individuals from a population‐based sample of twins aged 40–77 years. Age in this range did not seem to have any effect on the SSB parameters. However, γ‐H2AX response and DSB repair capacity decreased with increasing age, although the associations did not reach statistical significance after adjustment for batch effect across multiple experiments. No gender differences were observed for any of the parameters analyzed. Our findings suggest that in PBMCs, the repair of SSBs is maintained until old age, whereas the response to and the repair of DSBs decrease. 相似文献
997.
Ariadna Rangel Negrín Alejandro Coyohua Fuentes Amalia de la Torre Herrera Beatriz Cano Huertes Eduardo Reynoso Cruz Enrico Ceccarelli Eugenia E. Gómez Espinosa David R. Chavira Ramírez Diana E. Moreno Espinoza Domingo Canales-Espinosa Natalia Maya Lastra Pamela Cruz Miros Samuel Cañadas Santiago Sara Garau Pedro A. D. Dias 《American journal of physical anthropology》2021,174(3):396-406
998.
Anna Erika Vieira de Araujo Luis Vidal Conde Haroldo Cid da Silva Junior Lucas de Almeida Machado Flavio Alves Lara Alex Chapeaurouge Heidi Pauer Cristiane Cassiolato Pires Hardoim Luis Caetano Martha Antunes Ana Paula D'Alincourt Carvalho-Assef Jose Procopio Moreno Senna 《Microbes and infection / Institut Pasteur》2021,23(4-5):104801
Acinetobacter baumannii is an important nosocomial pathogen. BamA is a protein that belongs to a complex responsible for organizing the proteins on the bacterial outer membrane. In this work, we aimed to evaluate murine immune responses to BamA recombinant protein (rAbBamA) from A. baumannii in an animal model of infection, and to assess cross-reactivity of this target for the development of anti-A. baumannii vaccines or diagnostics. Immunization of mice with rAbBamA elicited high antibody titers and antibody recognition of native A. baumannii BamA. Immunofluorescence also detected binding to the bacterial surface. After challenge, immunized mice demonstrated a 40% survival increase and better bacterial clearance in kidneys. Immunoblot of anti-rAbBamA against other medically relevant bacteria showed binding to proteins of approximately 35 kDa in Klebsiella pneumoniae and Escherichia coli lysates, primarily identified as OmpA and OmpC, respectively. Altogether, our data show that anti-rAbBamA antibodies provide a protective response against A. baumannii infection in mice. However, the response elicited by immunization with rAbBamA is not completely specific to A. baumannii. Although a broad-spectrum vaccine that protects against various pathogens is an appealing strategy, antibody reactivity against the human microbiota is undesired. In fact, immunization with rAbBamA produced noticeable effects on the gut microbiota. However, the changes elicited were small and non-specific, given that no significant changes in the abundance of Proteobacteria were observed. Overall, rAbBamA is a promising target, but specificity must be considered in the development of immunological tools against A. baumannii. 相似文献
999.
Pemán J Cantón E Miñana JJ Florez JA Echeverria J Ortega DN Alarcón JM Fontanals D Sard BG Moreno BB Torroba L Ayats J Pérez MÁ Fernández MA Reus FS Natal IF García GR Ezpeleta G Martín-Mazuelos E Iglesias I Rezusta A de Ocariz IR Nieto AG;el Grupo de Estudio FUNGEMYCA 《Revista iberoamericana de micología》2011,28(2):91-99
1000.
Vicente-Rodríguez G Rey-López JP Ruíz JR Jiménez-Pavón D Bergman P Ciarapica D Heredia JM Molnar D Gutierrez A Moreno LA Ortega FB;HELENA Study Group 《Journal of strength and conditioning research / National Strength & Conditioning Association》2011,25(7):2059-2063
The aim of this study was to examine the interrater reliability (trained vs. untrained raters) and criterion-related validity (manual vs. automatic timing) of the 4 × 10-m shuttle run and 30-m running speed tests (times measured). The study comprised 85 adolescents (38 girls) aged 13.0-16.9 years from the Healthy Lifestyle in Europe by Nutrition in Adolescence study. The time required to complete the 4 × 10-m shuttle run and 30-m running tests was simultaneously measured (a) manually with a stopwatch by both trained and untrained raters (for interrater reliability analysis), and (b) by using photoelectric cells (for validity analysis). Systematic error, random error, and heteroscedasticity were studied with repeated-measured analysis of variance and Bland-Altman plots. The systematic error for untrained vs. trained raters and the untrained raters vs. photoelectric cells were in all cases ~0.1 seconds (p < 0.01), that is, untrained raters recorded higher times. No systematic error was found between trained raters and photoelectric cells (p > 0.05). No heteroscedasticity was shown in any case (p > 0.05). The findings indicate that manual measurements by a trained rater, using a stopwatch, seem to be a valid method to assess speed and agility fitness testing in adolescents. Researchers must be trained to minimize the measurement error. 相似文献