SIMULATION OF A SOLAR DRIVEN AIR CONDITIONING SYSTEM FOR A HOUSE IN DRY AND HOT CLIMATE OF ALGERIA

Solar cooling technology is environmentally friendly and contributes to a significant decrease of the CO2 emissions which cause the green house effect .Currently, most of the solar cooling systems commonly used are the hot water driven lithium bromide absorption chillers. According to the operating temperature of driving thermal source, single – effect Li Br/H2O absorption chillers have the advantage of being powered by ordinary flat-plate or evacuated tubular solar collectors available in the market. The main objective of this work is to develop a computational model that allows the simulation of an hourly basis for an absorption refrigeration - single - effect used the LiBr/H2O as solution working fluid- system assisted by solar energy and natural gas as auxiliary fuel coupled with the residential building located in the hot and dry climate of Algeria. This model will be developed using the dynamic simulation program TRNSYS, considering three specifics areas of work: determination of the cooling loads for a building, implementation of the computational model for the absorption refrigeration system and the parametric optimization of components, which will make possible an approach to optimal sizing of the solar absorption system. The results of the simulation of the absorption chiller indicate that an area of 28 m2 of flat plat collectors with an inclination of 35° and 800 L for hot storage tank provides an annual solar fraction of 80% and a thermal performance coefficient COP of 0.73, getting to cover demand of air conditioning in a house of 120 m2 located in Biskra (Algeria)

Lactate Dehydrogenase-B Is Silenced by Promoter Methylation in a High Frequency of Human Breast Cancers

Objective: Under normoxia, non-malignant cells rely on oxidative phosphorylation for their ATP production, whereas cancer cells rely on Glycolysis; a phenomenon known as the Warburg effect. We aimed to elucidate the mechanisms contributing to the Warburg effect in human breast cancer. Experimental design: Lactate Dehydrogenase (LDH) isoenzymes were profiled using zymography. LDH-B subunit expression was assessed by reverse transcription PCR in cells, and by Immunohistochemistry in breast tissues. LDH-B promoter methylation was assessed by sequencing bisulfite modified DNA. Results: Absent or decreased expression of LDH isoenzymes 1-4, were seen in T-47D and MCF7 cells. Absence of LDH-B mRNA was seen in T-47D cells, and its expression was restored following treatment with the demethylating agent 5'Azacytadine. LDH-B promoter methylation was identified in T-47D and MCF7 cells, and in 25/ 25 cases of breast cancer tissues, but not in 5/ 5 cases of normal breast tissues. Absent immuno-expression of LDH-B protein (<10% cells stained), was seen in 23/ 26 (88%) breast cancer cases, and in 4/8 cases of adjacent ductal carcinoma in situ lesions. Exposure of breast cancer cells to hypoxia (1% O2), for 48 hours resulted in significant increases in lactate levels in both MCF7 (14.0 fold, p = 0.002), and T-47D cells (2.9 fold, p = 0.009), but not in MDA-MB-436 (-0.9 fold, p = 0.229), or MCF10AT (1.2 fold, p = 0.09) cells. Conclusions: Loss of LDH-B expression is an early and frequent event in human breast cancer occurring due to promoter methylation, and is likely to contribute to an enhanced glycolysis of cancer cells under hypoxia

Lactate released by inflammatory bone marrow neutrophils induces their mobilization via endothelial GPR81 signaling.

Neutrophils provide first line of host defense against bacterial infections utilizing glycolysis for their effector functions. How glycolysis and its major byproduct lactate are triggered in bone marrow (BM) neutrophils and their contribution to neutrophil mobilization in acute inflammation is not clear. Here we report that bacterial lipopolysaccharides (LPS) or Salmonella Typhimurium triggers lactate release by increasing glycolysis, NADPH-oxidase-mediated reactive oxygen species and HIF-1α levels in BM neutrophils. Increased release of BM lactate preferentially promotes neutrophil mobilization by reducing endothelial VE-Cadherin expression, increasing BM vascular permeability via endothelial lactate-receptor GPR81 signaling. GPR81-/- mice mobilize reduced levels of neutrophils in response to LPS, unless rescued by VE-Cadherin disrupting antibodies. Lactate administration also induces release of the BM neutrophil mobilizers G-CSF, CXCL1 and CXCL2, indicating that this metabolite drives neutrophil mobilization via multiple pathways. Our study reveals a metabolic crosstalk between lactate-producing neutrophils and BM endothelium, which controls neutrophil mobilization under bacterial infection

Significance of glycolytic metabolism-related protein expression in colorectal cancer, lymph node and hepatic metastasis

Background: Colorectal cancer (CRC) is one of the most common malignancies and a leading cause of cancer death worldwide. Most cancer cells display high rates of glycolysis with production of lactic acid, which is then exported to the microenvironment by monocarboxylate transporters (MCTs). The main aim of this study was to evaluate the significance of MCT expression in a comprehensive series of primary CRC cases, lymph node and hepatic metastasis. Methods: Expressions of MCT1, MCT4, CD147 and GLUT1 were studied in human samples of CRC, lymph node and hepatic metastasis, by immunohistochemistry. Results: All proteins were overexpressed in primary CRC, lymph node and hepatic metastasis, when compared with non-neoplastic tissue, with exception of MCT1 in lymph node and hepatic metastasis. MCT1 and MCT4 expressions were associated with CD147 and GLUT1 in primary CRC. These markers were associated with clinical pathological features, reflecting the putative role of these metabolism-related proteins in the CRC setting. Conclusion: These findings provide additional evidence for the pivotal role of MCTs in CRC maintenance and progression, and support the use of MCTs as biomarkers and potential therapeutic targets in primary and metastatic CRC.This work was supported by the Fundação para a Ciência e a Tecnologia (FCT) grant ref. PTDC/SAU-FCF/104347/2008, under the scope of ‘Programa Operacional Temático Factores de Competitividade’ (COMPETE) of ‘Quadro Comunitário de Apoio III’ and co-financed by the Fundo Europeu De Desenvolvimento Regional (FEDER). Ricardo Amorim was recipient of the fellowship SFRH/BD/98002/2013, from Fundação para a Ciência e a Tecnologia (FCT Portugal).info:eu-repo/semantics/publishedVersio

Inside and out: the activities of senescence in cancer.

The core aspect of the senescent phenotype is a stable state of cell cycle arrest. However, this is a disguise that conceals a highly active metabolic cell state with diverse functionality. Both the cell-autonomous and the non-cell-autonomous activities of senescent cells create spatiotemporally dynamic and context-dependent tissue reactions. For example, the senescence-associated secretory phenotype (SASP) provokes not only tumour-suppressive but also tumour-promoting responses. Senescence is now increasingly considered to be an integrated and widespread component that is potentially important for tumour development, tumour suppression and the response to therapy.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/nrc377

Observations sur le developpement de

Le Bothriocephalidae Clestobothrium crassiceps possède un oeuf operculé et un coracidium cilié. La diagnose du genre est modifiée en conséquence

Spermiogenèse et ultrastructure du spermatozoïde de

La spermiogenèse de N. chantalae comparable à celle des autres Cestodes se caractérise par :

SIMULATION DU COMPORTEMENT ENERGETIQUEDES BATIMENTS RESIDENTIELS AU SUD ALGERIEN

Le programme d'amélioration de la performance énergétique des bâtiments résidentiels obéit à la volonté de l 'Algérie,de favoriser une utilisation plus responsable de l'énergie et d'explorer toutes les voies pour préserver les ressources et systématise r la consommation utile et optimale. Au niveau national le secteur résidentiel estle secteur le plus énergivore,il représente42 % de la consommation finale.L'objectif de ce travail est de contribuer à l'amélioration de l'efficacité énergétique des bâtiments résidentiels situés au climat chaud et sec.En premier lieu un état de l'art sur le bilan de consommation énergétique au niveau national et en particulier à la ville de Biskra est donné.Ensuite et dans le but de simuler le comportement énergétique du bâtiment, on a utilisé le logiciel TRNSYS. Deux types de bâtiment ont été simulés et comparés, l'un est considéré comme étant un bâtiment de référence BR et l'autre un bâtiment basse consommation BBCdont une enveloppe isolée (murs, terrasse et vitrage).Les résultats de la simulation montrent que les besoins énergétiques en refroidissement du bâtiment BBC font quasiment le 1/ 3 de ceux du bâtiment BR et que la différence de l'Intensité Energétique IE entre les deux bâtiments est de l'ordre de 70,62 KWh/m²