全文获取类型
收费全文 | 179篇 |
免费 | 12篇 |
专业分类
191篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 16篇 |
2014年 | 15篇 |
2013年 | 13篇 |
2012年 | 19篇 |
2011年 | 20篇 |
2010年 | 17篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 14篇 |
2006年 | 9篇 |
2005年 | 2篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 5篇 |
1999年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1963年 | 1篇 |
1960年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有191条查询结果,搜索用时 11 毫秒
121.
Removing heavy metals from synthetic effluents using “kamikaze” Saccharomyces cerevisiae cells 总被引:1,自引:0,他引:1
Lavinia Ruta Codruta Paraschivescu Mihaela Matache Sorin Avramescu Ileana Cornelia Farcasanu 《Applied microbiology and biotechnology》2010,85(3):763-771
One key step of the bioremediation processes designed to clean up heavy metal contaminated environments is growing resistant
cells that accumulate the heavy metals to ensure better removal through a combination of biosorption and continuous metabolic
uptake after physical adsorption. Saccharomyces cerevisiae cells can easily act as cation biosorbents, but isolation of mutants that are both hyperaccumulating and tolerant to heavy
metals proved extremely difficult. Instead, mutants that are hypersensitive to heavy metals due to increased and continuous
uptake from the environment were considered, aiming to use such mutants to reduce the heavy metal content of contaminated
waters. In this study, the heavy metal hypersensitive yeast strain pmr1∆ was investigated for the ability to remove Mn2+, Cu2+, Co2+, or Cd2+ from synthetic effluents. Due to increased metal accumulation, the mutant strain was more efficient than the wild-type in
removing Mn2+, Cu2+, or Co2+ from synthetic effluents containing 1–2 mM cations, with a selectivity $ {\text{Mn}}^{{{\text{2}} + }} > {\text{Co}}^{{{\text{2}} + }} ~ > {\text{Cu}}^{{{\text{2}} + }} $ {\text{Mn}}^{{{\text{2}} + }} > {\text{Co}}^{{{\text{2}} + }} ~ > {\text{Cu}}^{{{\text{2}} + }} and also in removing Mn2+ and Cd2+ from synthetic effluents containing 20–50 μM cations, with a selectivity Mn2+ > Cd2+. 相似文献
122.
Lavinia L. Ruta Valentina C. Popa Ioana Nicolau Andrei F. Danet Virgil Iordache Aurora D. Neagoe Ileana C. Farcasanu 《FEBS letters》2014
The involvement of Ca2+ in the response to high Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Hg2+ was investigated in Saccharomyces cerevisiae. The yeast cells responded through a sharp increase in cytosolic Ca2+ when exposed to Cd2+, and to a lesser extent to Cu2+, but not to Mn2+, Co2+, Ni2+, Zn2+, or Hg2+. The response to high Cd2+ depended mainly on external Ca2+ (transported through the Cch1p/Mid1p channel) but also on vacuolar Ca2+ (released into the cytosol through the Yvc1p channel). The adaptation to high Cd2+ was influenced by perturbations in Ca2+ homeostasis. Thus, the tolerance to Cd2+ often correlated with sharp Cd2+-induced cytosolic Ca2+ pulses, while the Cd2+ sensitivity was accompanied by the incapacity to rapidly restore the low cytosolic Ca2+. 相似文献
123.
124.
Nicola Amodio Dina Bellizzi Marzia Leotta Lavinia Raimondi Lavinia Biamonte Patrizia D’Aquila Maria Teresa Di Martino Teresa Calimeri Marco Rossi Marta Lionetti Emanuela Leone Giuseppe Passarino Antonino Neri Antonio Giordano Pierosandro Tagliaferri Pierfrancesco Tassone 《Cell cycle (Georgetown, Tex.)》2013,12(23):3650-3662
Epigenetic silencing of tumor suppressor genes frequently occurs and may account for their inactivation in cancer cells. We previously demonstrated that miR-29b is a tumor suppressor microRNA (miRNA) that targets de novo DNA methyltransferases and reduces the global DNA methylation of multiple myeloma (MM) cells. Here, we provide evidence that epigenetic activity of miR-29b leads to promoter demethylation of suppressor of cytokine signaling-1 (SOCS-1), a hypermethylated tumor suppressor gene. Enforced expression of synthetic miR-29b mimics in MM cell lines resulted in SOCS-1 gene promoter demethylation, as assessed by Sequenom MassARRAY EpiTYPER analysis, and SOCS-1 protein upregulation. miR-29b-induced SOCS-1 demethylation was associated with reduced STAT3 phosphorylation and impaired NFκB activity. Downregulation of VEGF-A and IL-8 mRNAs could be detected in MM cells transfected with miR-29b mimics as well as in endothelial (HUVEC) or stromal (HS-5) cells treated with conditioned medium from miR-29b-transfected MM cells. Notably, enforced expression of miR-29b mimics increased adhesion of MM cells to HS-5 and reduced migration of both MM and HUVEC cells. These findings suggest that miR-29b is a negative regulator of either MM or endothelial cell migration. Finally, the proteasome inhibitor bortezomib, which induces the expression of miR-29b, decreased global DNA methylation by a miR-29b-dependent mechanism and induced SOCS-1 promoter demethylation and protein upregulation. In conclusion, our data indicate that miR-29b is endowed with epigenetic activity and mediates previously unknown functions of bortezomib in MM cells. 相似文献
125.
A p53‐Dependent Tumor Suppressor Network Is Induced by Selective miR‐125a‐5p Inhibition in Multiple Myeloma Cells 下载免费PDF全文
126.
Alessandra Santillo Sara Falvo Paolo Chieffi Lavinia Burrone Gabriella Chieffi Baccari Salvatore Longobardi Maria Maddalena Di Fiore 《Theriogenology》2014
Previous studies have demonstrated that d-aspartic acid (d-Asp) has a role in regulating the release and synthesis of testosterone in rats. In this study, we investigated the molecular pathway by which this amino acid triggers its action in the rat testis. We found expression of N-Methyl-D-Aspartic Acid (NMDA) receptor messenger RNAs for NR1, NR2A, and NR2D receptor subunits. After d-Asp administration, NR1 and NR2A messenger RNA levels were significantly higher than those of controls, whereas NR2D levels remained unchanged. Expression of extracellular signal–regulated kinase (ERK) 1 protein was higher than that of ERK2 protein in the testis of both d-Asp–treated rats and controls. d-Asp administration increased testis levels of both phosphorylated ERK (P-ERK) 1 and 2. Using immunohistochemical technique, NR1 and P-ERK 1 or 2 proteins were preferentially localized within the spermatogonia. Moreover, d-Asp administration increased both serum and testis testosterone levels but not estradiol levels. Finally, in d-Asp–treated rats, testicular androgen receptor protein levels were significantly increased, whereas both estrogen receptor α and P-450 aromatase levels were significantly decreased. Conclusively, our results, besides strengthening the evidence that d-Asp administration in rats induces testosterone synthesis, demonstrate for the first time that d-Asp (1) induces testicular NMDA receptor–ERK pathway, (2) upregulates androgen receptor expression, and (3) downregulates estrogen receptor expression. 相似文献
127.
Jaqueline Bohrer Schuch Diana Muller Renata Giuliani Endres Cleonice Alves Bosa Dânae Longo Lavinia Schuler-Faccini Josiane Ranzan Michele Michelin Becker Rudimar dos Santos Riesgo Tatiana Roman 《Gene》2014
Autism Spectrum Disorders (ASDs) represent a group of very complex early-onset neurodevelopmental diseases. In this study, we analyzed 5 SNPs (rs2317385, rs5918, rs15908, rs12603582, rs3809865) at the β3 integrin locus (ITGB3), which has been suggested as a possible susceptibility gene, both as single markers and as part of haplotypes in 209 ASD children and their biological parents. We tested for association with the following: a) DSM-IV ASD diagnosis; b) clinical symptoms common in ASD patients (repetitive behaviors, echolalia, seizures and epilepsy, mood instability, aggression, psychomotor agitation, sleep disorders); and c) dimensional scores obtained with the Autism Screening Questionnaire and the Childhood Autism Rating Scale. These hypotheses were investigated using family-based tests, logistic regression models and analysis of covariance. The family-based tests showed an association with the H5 haplotype (composed by GTCGA alleles, the order of SNPs as above), which was transmitted less often than expected by chance (P = 0.006; Pcorr = 0.036). The analyses of the clinical symptoms showed a trend for an association with rs12603582 (P = 0.008; Pcorr = 0.064) and positive results for the haplotype composed of rs15908 and rs12603582 (Pglcorr = 0.048; Pindcorr = 0.015), both in symptoms of echolalia. Other nominal associations with different variants were found and involved epilepsy/seizures, aggression symptoms and higher ASQ scores. Although our positive results are not definitive, they suggest small effect associations of the ITGB3 gene with both ASD diagnosis and symptoms of echolalia. Other studies are nonetheless needed to fully understand the involvement of this locus on the etiology of ASDs and its different clinical aspects. 相似文献
128.
King-Hwa Ling Chelsee A Hewitt Kai-Leng Tan Pike-See Cheah Sharmili Vidyadaran Mei-I Lai Han-Chung Lee Ken Simpson Lavinia Hyde Melanie A Pritchard Gordon K Smyth Tim Thomas Hamish S Scott 《BMC genomics》2014,15(1)
Background
The Ts1Cje mouse model of Down syndrome (DS) has partial triplication of mouse chromosome 16 (MMU16), which is partially homologous to human chromosome 21. These mice develop various neuropathological features identified in DS individuals. We analysed the effect of partial triplication of the MMU16 segment on global gene expression in the cerebral cortex, cerebellum and hippocampus of Ts1Cje mice at 4 time-points: postnatal day (P)1, P15, P30 and P84.Results
Gene expression profiling identified a total of 317 differentially expressed genes (DEGs), selected from various spatiotemporal comparisons, between Ts1Cje and disomic mice. A total of 201 DEGs were identified from the cerebellum, 129 from the hippocampus and 40 from the cerebral cortex. Of these, only 18 DEGs were identified as common to all three brain regions and 15 were located in the triplicated segment. We validated 8 selected DEGs from the cerebral cortex (Brwd1, Donson, Erdr1, Ifnar1, Itgb8, Itsn1, Mrps6 and Tmem50b), 18 DEGs from the cerebellum (Atp5o, Brwd1, Donson, Dopey2, Erdr1, Hmgn1, Ifnar1, Ifnar2, Ifngr2, Itgb8, Itsn1, Mrps6, Paxbp1, Son, Stat1, Tbata, Tmem50b and Wrb) and 11 DEGs from the hippocampus (Atp5o, Brwd1, Cbr1, Donson, Erdr1, Itgb8, Itsn1, Morc3, Son, Tmem50b and Wrb). Functional clustering analysis of the 317 DEGs identified interferon-related signal transduction as the most significantly dysregulated pathway in Ts1Cje postnatal brain development. RT-qPCR and western blotting analysis showed both Ifnar1 and Stat1 were over-expressed in P84 Ts1Cje cerebral cortex and cerebellum as compared to wild type littermates.Conclusions
These findings suggest over-expression of interferon receptor may lead to over-stimulation of Jak-Stat signaling pathway which may contribute to the neuropathology in Ts1Cje or DS brain. The role of interferon mediated activation or inhibition of signal transduction including Jak-Stat signaling pathway has been well characterized in various biological processes and disease models including DS but information pertaining to the role of this pathway in the development and function of the Ts1Cje or DS brain remains scarce and warrants further investigation.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-624) contains supplementary material, which is available to authorized users. 相似文献129.
Ileana C. Farcasanu Radu Mitrica Ligia Cristache Ioana Nicolau Lavinia L. Ruta Liliana Paslaru Sorin Comorosan 《FEBS letters》2013
Optical manipulation of Saccharomyces cerevisiae cells with high density green photons conferred protection against the deleterious effects of UV radiation. Combining chemical screening with UV irradiation of yeast cells, it was noted that the high density green photons relied on the presence of intact unfolded protein response (UPR) pathway to exert their protective effect and that the low Ca2+ conditions boosted the effect. UPR chemical inducers tunicamycin, dithiotreitol and calcium chelators augmented the green light effect in a synergic action against UV-induced damage. Photo-manipulation of cells was a critical factor since the maximum protection was achieved only when cells were pre-exposed to green light. 相似文献