Analysis of a Trigeneration Plant under Transient Operating Conditions

Abstract A dynamic lumped-parameters model has been developed in order to analyse the performance of a combined cooling, heating and power (CCHP) plant during transient load variations. The plant allows the waste heat recovery from four Internal Combustion Engines (ICEs) to produce simultaneously refrigeration power for an absorption chiller, hot water for thermal user and electrical power. The heat recovery is realized through the exhaust gases, the jacket cooling water and the lubricant. The plant includes an auxiliary boiler, which maintains the water temperature levels to the values required by the absorption chiller, and a dry-cooler, which refrigerates the plant water before entering the internal combustion engines. Moreover, a three-way valve, which controls the water flow rate in order to satisfy both the refrigeration and the thermal loads, is considered. The simulations are carried out under thermal-drive and electric-drive strategy and the evaluation of the performance and time response of the CCHP apparatus are presented

Attitude towards drug therapy in a Community Mental Health Center evaluated by the Drug Attitude Inventory

Introduction: Negative attitude towards drug therapy can foster limited adherence to treatment, which remains one of the biggest obstacles for implementing effective treatments, especially long term. Purposes: The purposes of the study were 1) to evaluate the attitude towards drug therapy among a representative sample of patients treated in a community psychiatric service using 30-item Drug Attitude Inventory (DAI-30); 2) to evaluate the DAI-30 dimensions, applying factorial analysis; and 3) to highlight the socio-demographic and clinical variables correlated to DAI-30 score and factors. Methods: The DAI was administered, over a 7-month period, to all patients treated in our psychiatric outpatient services who agreed to participate in this study and provided their informed consent. Data were statistically analyzed. Results: With a response rate of 63.3%, 164 females and 136 males completed the DAI-30 with an average score of 14.24 (±10.46 SD), indicating moderately positive attitude towards drug therapy. The analysis of DAI-30 internal consistency confirmed its reliability (Cronbach’s alpha=0.84). Our factorial analysis highlighted three factors: Factor 1 (Cronbach’s alpha=0.81), composed of 7 items which indicate positive, trustful attitude; Factor 2 (Cronbach’s alpha=0.78), composed of 5 items indicating negative attitude of suspiciousness; and Factor 3 (Cronbach’s alpha=0.66), composed of 4 items suggesting defensive and control attitude towards drug therapy. Discussion: Among the selected variables, “monotherapy” and “total number of hospitalizations” were negatively correlated to the final score of DAI-30, whereas being “married” was positively correlated to it, in a statistically significant way, using the multiple linear regression model. These correlations suggest that positive attitude towards drug therapy could be reinforced by the condition of being married and reduced by relapses with hospitalization, as literature highlighted, and, paradoxically, by a monotherapy, which could suggest a sort of psychological dependence on therapy and, indirectly, on psychiatric service, potentially correlated to the long-term treatments of our patients

ANÁLISE BIOCLIMÁTICA DO MUNICÍPIO DE CARAGUATATUBA DE SÃO PAULO DE 1998 A 2006

The northern shore of São Paulo state is a region with around 300 thousands inhabitants, having the tourism as major economic activity. The harbor of São Sebastião increased its arrival and departure capacity of over the last ten years and in Caraguatatuba a new natural gas exporting base will be implemented in 2007. As a function of all these changes and the increment of the tourism activity the urban environment experienced considerable growth. Furthermore, this region presents elevated values of air temperatures, over 25oC most part of the year, as well as elevated values of relative air humidity, over 80% due to the proximity of the atlantic forest remaining in the sea mountain range (Serra do Mar). The civil constructive system used in the region is based on masonry of clay bricks and ferroconcrete structures, inadequate to the climate. The objective of this work is to do a data survey of air temperature and relative humidity during the period from 1998 to 2006, and through the bioclimatic index of Givone, determine the strategies for civil construction in the region in order to preserve the thermal comfort and the energetic efficiency of the buildings. We intend to edit a brochure with the major results of this work so that it can be used to orient the professionals in the region related to civil construction and architecture.O litoral norte do estado de São Paulo é uma região com cerca de 300 mil habitantes, tendo como principal atividade econômica o turismo. O porto de São Sebastião aumentou sua capacidade de embarque nos últimos dez anos e em Caraguatatuba será implantada uma base de exploração de gás natural em 2007. Em função de todas estas mudanças e o incremento da atividade turística houve um crescimento acentuado do meio urbano. Além disso, esta região apresenta valores elevados da temperatura do ar, acima dos 250C na maior parte do ano, assim como da umidade relativa do ar, acima dos 80% devido à proximidade da mata atlântica ainda existente na serra do mar. O sistema construtivo utilizado na região é baseado na alvenaria de tijolos de barro e estrutura de concreto armado, inadequados ao clima. O objetivo deste trabalho é fazer um levantamento dos dados de temperatura do ar e de umidade relativa entre os anos de 1998 e 2006, e através das cartas bioclimáticas de Givone, determinar as estratégias construtivas para a região de maneira que o conforto térmico e a eficiência energética das edificações sejam preservados. Pretende-se editar uma cartilha contendo os principais resultados deste estudo e a mesma poderá servir de orientação aos profissionais da região ligados a engenharia e arquitetura

Chagas Disease and Heart Failure: An Expanding Issue Worldwide

Chagas disease, originally a South American endemic health problem, is expanding worldwide because of people migration. Its main impact is on the cardiovascular system, producing myocardial damage that frequently results in heart failure. Pathogenic pathways are mainly related to inmunoinflamatory reactions in the myocardium and, less frequently, in the gastrointestinal tract. The heart usually shows fibrosis, producing dilatation and damage of the electrogenic cardiac system. These changes result in cardiomyopathy with heart failure and frequent cardiac arrhythmias and heart blocks. Diagnosis of the disease must include a lab test to detect the parasite or its immune reactions and the usual techniques to evaluate cardiac function. Therapeutic management of Chagas heart failure does not differ significantly from the most common treatment for dilated cardiomyopathy, with special focus on arrhythmias and several degrees of heart block. Heart transplantation is reserved for end-stage cases. Major international scientific organisations are delivering recommendations for prevention and early diagnosis. This article provides an analysis of epidemiology, prevention, treatment and the relationship between Chagas disease and heart failure

Toll-like receptor-4 is involved in hepatic fibrogenesis in the course of non-alcoholic fatty liver disease

Toll-like receptor-4 (TLR4) is actively involved in liver in the response to injury from a variety of etiologies. Recently TLR4 expression by hepatic progenitor cells (HPC) and biliary epithelial cells has been associated to the progression of liver damage in chronic HCV-related hepatitis (1). HPC compartment activation in ductular reaction (DR) is a feature of progressive disease also in non-alcoholic fatty liver disease (NAFLD) (2). We aimed to investigate the association among TLR4 expression, HPC compartment activation and histopathologic features of fibrotic disease progression in NAFLD. Seventy-four patients who had undergone liver biopsy were included and immunohistochemistry for TLR4 was performed on hepatic tissue samples. CK-7 was used to evaluate HPC, bile ducts (BD)/ductules of DR and intermediate hepatocytes; α-smooth muscle actin was used to quantify the activation of hepatic stellate cells (HSC) and of portal/septal myofibroblasts (MF). HPC in BD/DR were responsible for the highest TLR4 intensity of staining. TLR4-positive HPC and BD/ DR correlated with fibrosis (p<0.01 and p<0.05), activity of MF (p<0.001 and p<0.05) and HSC (p<0.001 and p<0.001), portal and interface chronic inflammation (p<0.01 and p=0.01). The present study indicates the activation of the TLR4 expressing HPC compartment as important determinant of the progressive liver damage in NAFLD. TLR4 stimulation could represent one of the mechanisms directly linking the activation of HPC to inflammation and fibrosis in NAFLD

Portal and interface chronic inflammation are associated with the progenitor cell compartment activation during NAFLD

Background and aim: During nonalcoholic fatty liver disease (NAFLD), portal and interface chronic inflammation (PCI and ICI) are strongly associated with fibrosis by activation of hepatic stellate cell (HSC)s (Brunt et al., 2009; Vespasiani-Gentilucci et al., 2014). However, the determinants of PCI and ICI observed in NAFLD remain to be elucidated. Since portal and periportal ductular reaction is related to disease progression, we aimed to investigate if PCI and ICI are associated with hepatic progenitor cell (HPC) compartment activation. Methods: Fifty-two NAFLD patients were studied. NAFLD activity score, fibrosis, PCI and ICI were histologically evaluated. HPCs, intermediate hepatobiliary cells and bile ductules/interlobular bile ducts were evaluated by immunohistochemistry for CK-7, CK-19 and EpCAM. HSC and myofibroblast (MF) activity were determined by immunohistochemistry for α-SMA. Results: PCI and ICI strongly correlated with HPC compartment activation and with the activity of MFs (p≤0.001). Lobular inflammation, ballooning and HPC compartment activation were all associated with both PCI (p<0.01) and ICI (p<0.05) by univariate analysis. In the multivariate models, HPC compartment activation was independently associated with PCI and ICI (OR 4.4, 1.7-11.5; OR 3.4, 1.5-7.9, respectively). Conclusions: During NAFLD, PCI and ICI are strongly associated with HPC compartment activation and this association is likely one determinant subtending the strong association between PCI/ICI and fibrosis

Reelin expression in liver and pancreas and its correlation with liver fibrosis

Reelin is an extracellular glycoprotein secreted by a variety of cell types in both embryonic and adult tissue and plays a critical role during brain development (1,2). Reelin is up-regulated in experimental liver cirrhosis of rats in hepatic stellate cell(HSC)s, the cell type mainly implicated in liver fibrogenesis, supporting that reelin is involved in the pathogenesis of liver fibrosis (3). Pancreatic stellate cell(PSC)s share similar morphology and function to HSCs, in pancreatic fibrosis setting (4). Currently, the role of reelin in human liver and pancreas is still unclear. We investigated reelin expression in different stages of chronic liver disease in 81 liver biopsies of HCV affected patients and in pancreatic tissue near to tumoral lesions. The expression of Reelin, HSC markers (CRBP1, alpha-SMA) and Dab1, a Reelin adaptor protein, was investigated by immunohistochemistry and immunofluorescence. Reelin protein was expressed by HSCs and a strong correlation was found between Reelin expression and liver fibrosis stage (

Molecular and histological traits of reduced lysosomal acid lipase activity in the fatty liver

Recent studies demonstrated reduced blood lysosomal acid lipase (LAL) activity in patients with nonalcoholic fatty liver disease (NAFLD). We aimed to verify hepatic LAL protein content and activity in in vitro and in vivo models of fat overload and in NAFLD patients. LAL protein content and activity were firstly evaluated in Huh7 cells exposed to high-glucose/high-lipid (HGHL) medium and in the liver of C57BL/6 mice fed with high-fat diet (HFD) for 4 and 8 months. LAL protein was also evaluated by immunohistochemistry in liver biopsies from 87 NAFLD patients and 10 controls, and correlated with hepatic histology. Huh7 cells treated with HGHL medium showed a significant reduction of LAL activity, which was consistent with reduced LAL protein levels by western blotting using an antibody towards the N-term of the enzyme. Conversely, antibodies towards the C-term of the enzyme evidenced LAL accumulation, suggesting a post-translational modification that masks the LAL N-term epitope and affects enzymatic activity. Indeed, we found a high rate of ubiquitination and extra-lysosomal localization of LAL protein in cells treated with HGHL medium. Consistent with these findings, inhibition of proteasome triggered dysfunctional LAL accumulation and affected LAL activity. Accumulation of ubiquitinated/dysfunctional LAL was also found in the liver of HFD fed mice. In NAFLD patients, hepatic levels of non-ubiquitinated/functional LAL were lower than in controls and inversely correlated with disease activity and some of the hallmarks of reduced LAL. Fat overload leads to LAL ubiquitination and impairs its function, possibly reducing hepatic fat disposal and promoting NAFLD activity