全文获取类型
收费全文 | 277篇 |
免费 | 28篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 13篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 18篇 |
2014年 | 19篇 |
2013年 | 18篇 |
2012年 | 22篇 |
2011年 | 11篇 |
2010年 | 15篇 |
2009年 | 6篇 |
2008年 | 16篇 |
2007年 | 11篇 |
2006年 | 11篇 |
2005年 | 9篇 |
2004年 | 9篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1998年 | 4篇 |
1996年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1981年 | 3篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1959年 | 1篇 |
1957年 | 1篇 |
1951年 | 1篇 |
1947年 | 1篇 |
1942年 | 1篇 |
1940年 | 1篇 |
1939年 | 1篇 |
排序方式: 共有305条查询结果,搜索用时 15 毫秒
1.
Nanna Brink Scholz Lars Bolund Mette Nyegaard Louise Faaborg Mette Warming J?rgensen Helle Lund Isa Niemann Lone Sunde 《PloS one》2015,10(11)
Hydatidiform moles (HMs) are abnormal human pregnancies with vesicular chorionic villi, imposing two clinical challenges; miscarriage and a risk of gestational trophoblastic neoplasia (GTN). The parental type of most HMs are either diandric diploid (PP) or diandric triploid (PPM). We consecutively collected 154 triploid or near-triploid samples from conceptuses with vesicular chorionic villi. We used analysis of DNA markers and/or methylation sensitive-MLPA and collected data from registries and patients records. We performed whole genome SNP analysis of one case of twinning (PP+PM).In all 154 triploids or near-triploids we found two different paternal contributions to the genome (P1P2M). The ratios between the sex chromosomal constitutions XXX, XXY, and XYY were 5.7: 6.9: 1.0. No cases of GTN were observed. Our results corroborate that all triploid human conceptuses with vesicular chorionic villi have the parental type P1P2M. The sex chromosomal ratios suggest approximately equal frequencies of meiosis I and meiosis II errors with selection against the XYY conceptuses or a combination of dispermy, non-disjunction in meiosis I and meiosis II and selection against XYY conceptuses. Although single cases of GTN after a triploid HM have been reported, the results of this study combined with data from previous prospective studies estimate the risk of GTN after a triploid mole to 0% (95% CI: 0–1,4%). 相似文献
2.
3.
The life-cycle of the ancient asexual ostracod Darwinula stevensoni was studied during 1 year in a eutrophic pond in Belgium. The reproductive period of this species started in March and was effectively completed by September of the same year. All changes in population structure took place during the spring and summer months and a rapid turnover of the instars was observed. The life-cycle of Darwinula stevensoni appears to take one year or less in Belgium and this is considerably shorter than the 4 years which had been reported previously from subarctic populations. The difference to the present study is most likely temperature-related. Maximal densities of D. stevensoni were observed in June and July and attained 105 ind. m–2. During winter, densities were lower with a mean of 104 ind. m–2. Consequently, the calculated population size of each month was high throughout the year. Together with the low mutation rate, such a large population size could effectively counteract the stochastic loss of mutation-free genotypes as predicted by Muller's ratchet. D. stevensoni is a brooder; the maximum number of embryos and juvenile instars (up to third stage) found within a single female was 11. 相似文献
4.
Jose Luis Lopez Guerra Nicolas Isa Michelle M. Kim Celine Bourgier Hugo Marsiglia 《Reports of Practical Oncology and Radiotherapy》2012,17(5):251-254
AimTo assess the role of the young radiation oncologist in the context of important recent advancements in the field of radiation oncology, and to explore new perspectives and competencies of the young radiation oncologist.BackgroundRadiation oncology is a field that has rapidly advanced over the last century. It holds a rich tradition of clinical care and evidence-based practice, and more recently has advanced with revolutionary innovations in technology and computer science, as well as pharmacology and molecular biology.Materials and methodsSeveral young radiation oncologists from different countries evaluated the current status and future directions of radiation oncology.ResultsFor young radiation oncologists, it is important to reflect on the current practice and future directions of the specialty as it relates to the role of the radiation oncologist in the comprehensive management of cancer patients. Radiation oncologists are responsible for the radiation treatment provided to patients and its subsequent impact on patients’ quality of life. Young radiation oncologists must proactively master new clinical, biological and technical information, as well as lead radiation oncology teams consisting of physicists, dosimetrists, nurses and technicians.ConclusionsThe role of the young radiation oncologist in the field of oncology should be proactive in developing new competencies. Above all, it is important to remember that we are dealing with the family members and loved ones of many individuals during the most difficult part of their lives. 相似文献
5.
6.
7.
Christoph Domschke Yingzi Ge Isa Bernhardt Sarah Schott Sophia Keim Simone Juenger Mariana Bucur Luisa Mayer Maria Blumenstein Joachim Rom Joerg Heil Christof Sohn Andreas Schneeweiss Philipp Beckhove Florian Schuetz 《Cancer immunology, immunotherapy : CII》2013,62(6):1053-1060
Background
The bone marrow (BM) of breast cancer patients harbors tumor-reactive memory T cells (TCs) with therapeutic potential. We recently described the immunologic effects of adoptive transfer of ex vivo restimulated tumor-reactive memory TCs from the BM of 12 metastasized breast cancer patients in a clinical phase-I study. In this trial, adoptive T cell transfer resulted in the occurrence of circulating tumor antigen-reactive type-1 TCs. We here describe the long-term clinical outcome and its correlation with tumor-specific cellular immune response in 16 metastasized breast cancer patients, including 12 included in the original study.Methods
Sixteen metastatic breast cancer patients with preexisting tumor-reactive BM memory TCs were included into the study. The study protocol involved one transfusion of TCs which were reactivated in vitro with autologous dendritic cells pulsed with lysates of MCF-7 breast cancer cells as source of tumor antigens. The presence of tumor-reactive memory TCs was analyzed by IFN-γ ELISpot assays.Results
Tumor-reactive memory TCs in the peripheral blood were induced de novo in 7/16 patients (44 %) after adoptive TC transfer. These patients were considered immunologic responders to the therapy. Positive adoptive immunotherapy (ADI) response was observed significantly more often in patients without bone metastases (p = 0.0051), in patients with high levels of tumor-reactive BM TCs prior to therapy (p = 0.036) and correlated significantly with the estimated numbers of transferred tumor-reactive TCs (p = 0.0021). After the treatment, we observed an overall median survival of 33.8 months in the total cohort with three patients alive at last follow-up and more than 7 years after ADI. Numbers of transferred tumor-reactive TCs correlated significantly with the overall survival of patients (p = 0.017). Patients with an immunologic response to ADI in the peripheral blood had a significantly longer median survival than nonresponders (median survival 58.6 vs. 13.6 months; p = 0.009).Conclusion
In metastasized breast cancer patients, adoptive transfer of BM TCs can induce the presence of tumor antigen-reactive type-1 TCs in the peripheral blood. Patients with immunologic response after ADI show a significantly longer overall survival. Patients with bone metastases significantly less frequently respond to the treatment and, therefore, might not be optimal candidates for ADI. Although the present study does not yet prove the therapeutic effect of ADI, these findings shed light on the relation between immune response and cancer prognosis and suggest that transfer of reactivated BM TCs might bear therapeutic potential. 相似文献8.
9.
Miguel Angel Martínez Susana López Carlos F. Arias Pavel Isa 《Journal of virology》2013,87(2):1115-1122
Cell entry of rotaviruses is a complex process, which involves sequential interactions with several cell surface molecules. Among the molecules implicated are gangliosides, glycosphingolipids with one or more sialic acid (SA) residues. The role of gangliosides in rotavirus cell entry was studied by silencing the expression of two key enzymes involved in their biosynthesis—the UDP-glucose:ceramide glucosyltransferase (UGCG), which transfers a glucose molecule to ceramide to produce glucosylceramide GlcCer, and the lactosyl ceramide-α-2,3–sialyl transferase 5 (GM3-s), which adds the first SA to lactoceramide-producing ganglioside GM3. Silencing the expression of both enzymes resulted in decreased ganglioside levels (as judged by GM1a detection). Four rotavirus strains tested (human Wa, simian RRV, porcine TFR-41, and bovine UK) showed a decreased infectivity in cells with impaired ganglioside synthesis; however, their replication after bypassing the entry step was not affected, confirming the importance of gangliosides for cell entry of the viruses. Interestingly, viral binding to the cell surface was not affected in cells with inhibited ganglioside synthesis, but the infectivity of all strains tested was inhibited by preincubation of gangliosides with virus prior to infection. These data suggest that rotaviruses can attach to cell surface in the absence of gangliosides but require them for productive cell entry, confirming their functional role during rotavirus cell entry. 相似文献
10.
Isaías Cabrini Maicon D. Grella Carlos F. S. Andrade Patrícia J. Thyssen 《Biodiversity and Conservation》2013,22(11):2635-2643
Studies measuring the damage in degraded environments have increased, and it is necessary to obtain reliable biological and ecological indicators for the recovery of such degraded environments and subsequent preservation. This study aimed to conduct a survey of local insects and evaluate their utility in monitoring forest restoration in a degraded area in the Atlantic Forest biome in Ribeirao Grande, State of São Paulo, Brazil. Collections with Shuey traps were conducted from 2006 to 2011 in four distinct forest fragments characterized by environmental impacts, human actions, and phytophysiognomic profiles: Forest (FO), a preserved area with native plant species; “Capoeira” (CA), an area in the natural regeneration process; Planting (PL), an area reforested with native plants; and Pasture (PA), an area with only shrubs. A total of 2,456 specimens of Calliphoridae (Diptera) were collected. Mesembrinella bellardiana was the most abundant (n = 1,884) and dominant species in all environments sampled. The relative abundance of M. bellardiana in the most preserved environment (60.2 % FO, 24.4 % CA, 8.6 % PL, and 6.7 % PA) and other ecological parameters showed that it could be a bioindicator species, i.e., data on its presence or absence directly reflected the status of local preservation. Information on Neotropical dipterans associated with the forested environment is very scarce in the literature. To our knowledge, this is the first study describing the occurrence of Calliphora lopesi (Calliphoridae) in the State of São Paulo. 相似文献