首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   8篇
  免费   2篇
  2021年   1篇
  2016年   2篇
  2014年   1篇
  2013年   1篇
  2010年   3篇
  2007年   1篇
  2001年   1篇
排序方式: 共有10条查询结果,搜索用时 31 毫秒
1
1.
2.

Background  

Metabolic flux profiling based on the analysis of distribution of stable isotope tracer in metabolites is an important method widely used in cancer research to understand the regulation of cell metabolism and elaborate new therapeutic strategies. Recently, we developed software Isodyn, which extends the methodology of kinetic modeling to the analysis of isotopic isomer distribution for the evaluation of cellular metabolic flux profile under relevant conditions. This tool can be applied to reveal the metabolic effect of proapoptotic drug edelfosine in leukemia Jurkat cell line, uncovering the mechanisms of induction of apoptosis in cancer cells.  相似文献   
3.
4.
5.

Background

Fairy shrimps (Anostraca), tadpole shrimps (Notostraca), clam shrimps (Spinicaudata), algae (primarily filamentous blue-green algae [cyanobacteria]), and suspended organic particulates are dominant food web components of the seasonally inundated pans and playas of the western Mojave Desert in California. We examined the extent to which these branchiopods controlled algal abundance and species composition in clay pans between Rosamond and Rogers Dry Lakes. We surveyed branchiopods during the wet season to estimate abundances and then conducted a laboratory microcosm experiment, in which dried sediment containing cysts and the overlying algal crust were inundated and cultured. Microcosm trials were run with and without shrimps; each type of trial was run for two lengths of time: 30 and 60 days. We estimated the effect of shrimps on algae by measuring chlorophyll content and the relative abundance of algal species.

Results

We found two species of fairy shrimps (Branchinecta mackini and B. gigas), one tadpole shrimp (Lepidurus lemmoni), and a clam shrimp (Cyzicus setosa) in our wet-season field survey. We collected Branchinecta lindahli in a pilot study, but not subsequently. The dominant taxa were C. setosa and B. mackini, but abundances and species composition varied greatly among playas. The same species found in field surveys also occurred in the microcosm experiment. There were no significant differences as a function of experimental treatments for either chlorophyll content or algal species composition (Microcoleus vaginatus dominated all treatments).

Conclusions

The results suggest that there was no direct effect of shrimps on algae. Although the pans harbored an apparently high abundance of branchiopods, these animals had little role in regulating primary producers in this environment.  相似文献   
6.
Previous research on risk factors for obstructive heart defects (OHDs) focused on maternal and infant genetic variants, prenatal environmental exposures, and their potential interaction effects. Less is known about the role of paternal genetic variants or environmental exposures and risk of OHDs. We examined parent-of-origin effects in transmission of alleles in the folate, homocysteine, or transsulfuration pathway genes on OHD occurrence in offspring. We used data on 569 families of liveborn infants with OHDs born between October 1997 and August 2008 from the National Birth Defects Prevention Study to conduct a family-based case-only study. Maternal, paternal, and infant DNA were genotyped using an Illumina Golden Gate custom single nucleotide polymorphism (SNP) panel. Relative risks (RR), 95% confidence interval (CI), and likelihood ratio tests from log-linear models were used to estimate the parent-of-origin effect of 877 SNPs in 60 candidate genes in the folate, homocysteine, and transsulfuration pathways on the risk of OHDs. Bonferroni correction was applied for multiple testing. We identified 3 SNPs in the transsulfuration pathway and 1 SNP in the folate pathway that were statistically significant after Bonferroni correction. Among infants who inherited paternally-derived copies of the G allele for rs6812588 in the RFC1 gene, the G allele for rs1762430 in the MGMT gene, and the A allele for rs9296695 and rs4712023 in the GSTA3 gene, RRs for OHD were 0.11 (95% CI: 0.04, 0.29, P = 9.16x10-7), 0.30 (95% CI: 0.17, 0.53, P = 9.80x10-6), 0.34 (95% CI: 0.20, 0.57, P = 2.28x10-5), and 0.34 (95% CI: 0.20, 0.58, P = 3.77x10-5), respectively, compared to infants who inherited maternally-derived copies of the same alleles. We observed statistically significant decreased risk of OHDs among infants who inherited paternal gene variants involved in folate and transsulfuration pathways.  相似文献   
7.
BACKGROUND: Birth defects and preterm birth (PTB) are leading causes of infant morbidity and mortality in the United States. Infants with birth defects are more likely to be born preterm (<37 weeks), yet the roles of maternal ethnicity and fetal growth in this relationship are unclear. This study aimed to assess the risk of PTB among non-Hispanic (NH) Black, NH-White, and Hispanic infants with congenital heart defects (CHD), adjusting for fetal growth. METHODS: Florida Birth Defects Registry data were used to conduct a retrospective cohort study on 14,319 live-born infants with CHDs born January 1, 1998 to December 31, 2002. ORs and 95% CIs were computed for each growth category (small-for-gestational age [SGA], appropriate-for-gestational-age [AGA], and large-for-gestational-age [LGA]) by ethnicity and adjusted for maternal and infant covariates using logistic regression. RESULTS: After adjusting for potential confounders, SGA and AGA NH-Black infants with CHDs had increased risk of PTB compared to NH-White infants with CHDs (OR 1.79; 95% CI: 1.40, 2.30 and OR 1.89; 95% CI: 1.68, 2.13, respectively). Hispanic SGA, AGA, and infants with CHDs had no increased risk of PTB compared to NH-White infants. CONCLUSIONS: The increased risk of PTB among SGA and AGA NH-Black infants with CHDs is not explained by the overall disparities in risk of PTB between NH-Blacks and NH-Whites. Additional studies are needed to determine the specific subtypes of CHD for which these relationships are present and if these findings are seen among infants with other birth defects.  相似文献   
8.
BACKGROUND: Few registry-based studies have investigated survival among infants with congenital anomalies. We conducted a registry-based study to examine patterns and probability of survival during the first year of life among infants with selected congenital anomalies. METHODS: Data from the Texas Birth Defects Monitoring Division were merged with linked birth-infant death files for 2,774 infants born January 1, 1995 to December 31, 1997, with at least 1 of 23 common anomalies. Deaths before the first birthday were assessed from infant death files. Kaplan-Meier was used to estimate first-year survival; first-year survival was assessed for specific anomalies and by the number of life-threatening anomalies. RESULTS: Overall, 80.8% of infants with these 23 anomalies survived the first year of life. We observed the highest survival rates for infants with gastroschisis (92.9%, 95% CI = 86.8, 96.3), trisomy 21 (92.3%, 95% CI = 89.5, 94.4) or cleft lip with or without cleft palate (87.6%, 95% CI = 84.0, 90.5). Infants with intermediate survival rates included those with microcephaly (79.7%; 95% CI = 73.6, 84.6), tetralogy of Fallot (75.0%; 95% CI = 65.5, 82.2), or with diaphragmatic hernia (72.8%; 95% CI = 61.8, 81.2). As expected, all infants with anencephaly and almost all infants with trisomy 13 or trisomy 18 died during the first year of life. First-year survival declined as the number of co-occurring life-threatening anomalies increased. CONCLUSIONS: Overall, first-year survival for infants with congenital anomalies was high. Additional population-based studies are needed to quantify improvements in first-year survival.  相似文献   
9.
10.
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号