49 research outputs found
Reliability analysis of solar-gas hybrid receivers for Central Tower Plants
A novel Solar-Gas Hybrid Receiver (SGHR) that combines the function of a solar receiver and a gas boiler in a single device is presented. This concept requires less equipment and maintenance compared to the Solar Gas Hybrid(SGH) concept, in which the boiler and the solar receiver (SR) are independent devices. The economic benefit is attributed to the increased sharing of infrastructures. Additionally, it has less thermal stress, cycles and shocks, which reduce the failure risk. However, the additional benefit in the reliability of these receivers has not been analyzed so far. In this work, a mathematical model of SGHR is presented. It determines the stress in steady state which is used to estimate the allowable transient stress in order to achieve the required 30 years life design. The results show that the SGHR is exposed to lower thermal stress due to much better temperature distribution. Moreover the higher …info:eu-repo/semantics/publishedVersio
Reliability analysis of Solar-Gas Hybrid Receivers for central tower plants
A novel Solar-Gas Hybrid Receiver (SGHR) that combines the function of a solar receiver and a gas boiler in a single device is
presented. This concept requires less equipment and maintenance compared to the Solar Gas Hybrid (SGH) concept, in which the
boiler and the solar receiver (SR) are independent devices. The economic benefit is attributed to the increased sharing of
infrastructures. Additionally, it has less thermal stress, cycles and shocks, which reduce the failure risk. However, the additional
benefit in the reliability of these receivers has not been analyzed so far. In this work, a mathematical model of SGHR is
presented. It determines the stress in steady state which is used to estimate the allowable transient stress in order to achieve the
required 30 years life design. The results show that the SGHR is exposed to lower thermal stress due to much better temperature
distribution. Moreover the higher absorber heat flux of SGHR is translated in a higher mechanical stress with could jeopardizes
the durability. However the reduced number of cycles and the lower thermal stress of a SGHR allows higher transient stresses
than the conventional tube type solar receiver, which lead to more reliable and efficient designs
Giving VCU A Choice... VCUHS ChoiceCare
Virginia Commonwealth University has the opportunity to promote the quality health care services being rendered by the VCU Health System and the VCU School of Dentistry to its staff and faculty. Our project proposes that the VCUHS ChoiceCARE Health Plan be made available as an option to the entire University community. The VCUHS ChoiceCARE Health Plan is currently being offered to all employees of the Virginia Commonwealth University Health System. This is an exceptional health care plan that encourages employees to utilize the services ofthe MCV Physicians/Hospitals and VCU Dentists/Oral Dentistry practitioners. Through financial incentives of lower or no copays required and competitive monthly premiums, employees will benefit from this alternative. The VCU Health System and the VCU School of Dentistry will benefit from an improved insured patient base and from maintaining a healthy workforce. As the third largest employer in the Richmond metropolitan area, VCU employees and their families are an obvious market for the health care services. This project is another step in helping University programs become less financially dependent on governmental funding
The mitochondrial activity of leukocytes from Artibeus jamaicensis bats remains unaltered after several weeks of flying restriction
Bats are the only flying mammals known. They have longer lifespan than other mammals of similar size and weight and can resist high loads of many pathogens, mostly viruses, with no signs of disease. These distinctive characteristics have been attributed to their metabolic rate that is thought to be the result of their flying lifestyle. Compared with non-flying mammals, bats have lower production of reactive oxygen species (ROS), and high levels of antioxidant enzymes such as superoxide dismutase. This anti-oxidative vs. oxidative profile may help to explain bat's longer than expected lifespans. The aim of this study was to assess the effect that a significant reduction in flying has on bats leukocytes mitochondrial activity. This was assessed using samples of lymphoid and myeloid cells from peripheral blood from Artibeus jamaicensis bats shortly after capture and up to six weeks after flying deprivation. Mitochondrial membrane potential (Δψm), mitochondrial calcium (mCa2+), and mitochondrial ROS (mROS) were used as key indicators of mitochondrial activity, while total ROS and glucose uptake were used as additional indicators of cell metabolism. Results showed that total ROS and glucose uptake were statistically significantly lower at six weeks of flying deprivation (p 0.05). These results suggest that bat mitochondria are stable to sudden changes in physical activity, at least up to six weeks of flying deprivation. However, decrease in total ROS and glucose uptake in myeloid cells after six weeks of captivity suggest a compensatory mechanism due to the lack of the highly metabolic demands associated with flying
Homocysteine and cognition: A systematic review of 111 studies
Background
Elevated plasma homocysteine (Hcy) levels have been associated with cognitive dysfunction in a wide range of conditions. The aim of this review is to establish which cognitive domains and populations are the most affected.
Methods
We systematically review the literature and consider all articles that showed any relationship between plasma Hcy levels and scores achieved on cognitive performance tests in both, the general population and patients suffering from central nervous system disorders and other diseases. When effect sizes were available and combinable, several meta-analyses were performed.
Results
We found 111 pertinent articles. There were 24 cohort studies, 18 randomized trials, 21 case-control studies, and 48 cross-sectional studies. This review reveals a positive trend between cognitive decline and increased plasma Hcy concentrations in general population and in patients with cognitive impairments. Results from the meta-analyses also confirm this trend. Treatment with vitamin supplementation fails to show a reduction in cognitive decline.
Discussion
Further investigations are warranted to clarify this relationship. Earlier detection of the elevated Hcy levels may be an effective intervention to prevent cognitive impairment and dementia
Stability of schizophrenia diagnosis in a ten-year longitudinal study on first episode of non-affective psychosis: conclusions from the PAFIP cohort
OBJECTIVE: To evaluate the ten-year stability of schizophrenia diagnosis in a cohort of first-episode psychosis (FEP) patients and the factors associated with it. METHODS: Changes in diagnosis of 209 FEP patients were described during ten years of follow-up. Related factors with maintenance or change of schizophrenia diagnosis were evaluated in prospective and retrospective approaches through Binary Logistic Regressions, ROC and survival curves. RESULTS: Out of the 209 patients, 126 were diagnosed of schizophrenia six months after their inclusion in the clinical program. Prospective analyses showed that eight of those 126 schizophrenia patients had changed to a different diagnosis after ten years, and predictors of change were better childhood premorbid adjustment, less severity of clinical global impression at baseline, and diagnosis of comorbid personality disorder during follow-up. Retrospectively, out of the 154 patients with schizophrenia in the ten-year assessment, 36 had a different diagnosis at baseline, and those factors related with a different prior diagnosis than schizophrenia were better socioeconomic status and shorter duration of untreated psychosis (DUP). A survival analysis on the timing of schizophrenia diagnosis showed that male gender and longer DUP were predictors of earlier definite diagnosis. CONCLUSIONS: Diagnostic stability of schizophrenia in our FEP sample is high, especially prospective stability, and the group of patients with diagnostic change corresponded to a milder psychopathological profile before and at the onset of disease. Moreover, we observed a cautious attitude in the diagnosis of schizophrenia in patients with shorter DUP who had schizophrenia diagnosis after ten years
Endemic Circulation of European Bat Lyssavirus Type 1 in Serotine Bats, Spain
To determine the presence of European bat lyssavirus type 1 in southern Spain, we studied 19 colonies of serotine bats (Eptesicus isabellinus), its main reservoir, during 1998–2003. Viral genome and antibodies were detected in healthy bats, which suggests subclinical infection. The different temporal patterns of circulation found in each colony indicate independent endemic circulation
Epigenetic inactivation of the splicing RNA-binding protein CELF2 in human breast cancer
Altres ajuts: This work was co-finaced by the European Development Regional Fund, "A way to achieve Europe" ERDF; the Cellex Foundation; and "la Caixa" Banking Foundation (LCF/PR/PR15/ 11100003).Human tumors show altered patterns of protein isoforms that can be related to the dysregulation of messenger RNA alternative splicing also observed in transformed cells. Although somatic mutations in core spliceosome components and their associated factors have been described in some cases, almost nothing is known about the contribution of distorted epigenetic patterns to aberrant splicing. Herein, we show that the splicing RNA-binding protein CELF2 is targeted by promoter hypermethylation-associated transcriptional silencing in human cancer. Focusing on the context of breast cancer, we also demonstrate that CELF2 restoration has growth-inhibitory effects and that its epigenetic loss induces an aberrant downstream pattern of alternative splicing, affecting key genes in breast cancer biology such as the autophagy factor ULK1 and the apoptotic protein CARD10. Furthermore, the presence of CELF2 hypermethylation in the clinical setting is associated with shorter overall survival of the breast cancer patients carrying this epigenetic lesion
Reemerging Rabies and Lack of Systemic Surveillance in People’s Republic of China
Standardized protocols and diagnostic-based surveillance are imperative for detection and elimination
A DERL3-associated defect in the degradation of SLC2A1 mediates the Warburg effect
Cancer cells possess aberrant proteomes that can arise by the disruption of genes involved in physiological protein degradation. Here we demonstrate the presence of promoter CpG island hypermethylation-linked inactivation of DERL3 (Derlin-3), a key gene in the endoplasmic reticulum-associated protein degradation pathway, in human tumours. The restoration of in vitro and in vivo DERL3 activity highlights the tumour suppressor features of the gene. Using the stable isotopic labelling of amino acids in cell culture workflow for differential proteome analysis, we identify SLC2A1 (glucose transporter 1, GLUT1) as a downstream target of DERL3. Most importantly, SLC2A1 overexpression mediated by DERL3 epigenetic loss contributes to the Warburg effect in the studied cells and pinpoints a subset of human tumours with greater vulnerability to drugs targeting glycolysis.Seventh Framework Programme (European Commission) (Grant HEALTH-F5-2010-258236-SYSCOL)Seventh Framework Programme (European Commission) (Grant HEALTH-F2-2011-259015-COLTHERES)Cellex FoundationOlga Torres FoundationEuropean Research Council (EPINORC Project Grant Agreement 268626)Spain. Ministerio de Economia y Competividad (MINECO Project SAF2011-22803)Institute of Health Carlos III (RTICC Grant RD12/0036/0039