183 research outputs found
Evaluation of wood preservatives against the drywood termite, Incisitermes minor
Tese de doutoramento em Arte Contemporânea, apresentada ao Colégio das Artes da Universidade de Coimbra
Human blood group A and H glycolipids in porcine plasma Evidence for acquisition of the erythrocyte antigens from plasma
AbstractHuman blood group A- and H-antigenic glycosphingolipids were isolated from pooled porcine plasma. The structures of the A-active hexa- and H-active pentaglycosylceramides of lactoseries (type 1 sugar chain) were the same as those in porcine erythrocytes. These results endorse biochemically the previous observations that the A and H antigens on porcine erythrocytes are taken up from plasma
Periodic alternation between intake and exhaust of air in dynamic insulation
Dynamic insulation (DI) can recover heat lost in conduction by drawing cold outdoor air into indoor through an insulation wall in winter. A “breathing DI” system we proposed in the past has functions both as an insulated envelope and as a highly efficient heat exchanger for ventilation. It is alternated periodically that the outdoor air is drawn through half of walls made of breathable inorganic concrete (BIC) and the indoor air is exhausted through the other half of the BIC walls. In order to put the breathing DI system into practice in housing construction, this paper presents some studies from various points of view in addition to the past studies on heat and moisture transport based on laboratory experiments and numerical simulations. We first experimentally studied the filtering efficiency and clogging of a BIC panel. This showed that approximately 30 % of the atmospheric dust can be captured by a BIC panel and no clogging would occur for at least 10 years. We also measured the sorption and desorption of formaldehyde by a BIC panel to confirm the effectiveness of a BIC wall to sorb gaseous state formaldehyde. We furthermore constructed a new test house at Ibaraki, Japan, to confirm the thermal performance of the breathing DI system based on full scale experiments
Induction of Tissue Factor Expression in Endothelial Cells by Basic Fibroblast Growth Factor and its Modulation by Fenofibric acid
BACKGROUND: Tissue factor (TF), expressed in endothelial cells (ECs) and enriched in human atherosclerotic lesions, acts as a critical initiator of blood coagulation in acute coronary syndrome. Basic fibroblast growth factor (bFGF) induces the proliferation and migration of ECs and plays a role in angiogenesis and restoration of endothelial integrity. As TF is implicated in angiogenesis, we studied the effect of bFGF on TF gene and protein expression. Methods: Human umbilical vein ECs (HUVECs) were exposed to bFGF. TF mRNA was assessed by Northern blot and TF protein was assessed by Western blot. TF promoter activity was assessed by transient transfection assay and transcription factor was identified by electro mobility shift assay. RESULTS: bFGF increased TF mRNA and protein expression in HUVECs. Increased TF mRNA was attenuated by inhibition of extracellular signal-regulated kinase kinase in human ECV304 cells. Transient transfection assays of the human TF promoter-luciferase construct (-786/+121 bp) demonstrated that bFGF induced transcription was dependent on the elements within the -197 to -176 bp relative to the transcription start site of the human TF gene. This region contains NF-κB like binding site. Electro mobility shift assay showed that bFGF increased nuclear translocation or DNA binding of NF-κB transcription factor to TF promoter. Nucleotide substitution to disrupt NF-κB like site reduced bFGF stimulated promoter activity. Fenofibric acid, an agonist ligand for the peroxisome proliferator activated receptor-α, reduced basal and bFGF stimulated TF expression. CONCLUSIONS: These results indicate that bFGF may increase TF production in ECs through activation of transcription at NF-κB binding site, and control coagulation in vessel walls. Fibrate can inhibit TF expression and therefore reduce the thrombogenecity of human atherosclerotic lesions
The Sarin-like Organophosphorus Agent bis(isopropyl methyl)phosphonate Induces Apoptotic Cell Death and COX-2 Expression in SK-N-SH Cells
Organophosphorus compounds, such as sarin, are highly toxic nerve agents that inhibit acetylcholinesterase (AChE), but not cholinesterase, via multiple mechanisms. Recent studies have shown that organophosphorus compounds increase cyclooxygenase-2 (COX-2) expression and induce neurotoxicity. In this study, we examined the toxicity of the sarin-like organophosphorus agent bis(isopropyl methyl)phosphonate (BIMP) and the effects of BIMP on COX-2 expression in SK-N-SH human neuroblastoma cells. Exposure to BIMP changed cell morphology and induced caspase-dependent apoptotic cell death accompanied by cleavage of caspase 3, caspase 9, and poly (ADP-ribose) polymerase (PARP). It also increased COX-2 expression, while pretreatment with a COX inhibitor, ibuprofen, decreased BIMP-dependent cell death and COX-2 expression in SK-N-SH cells. Thus, our findings suggest that BIMP induces apoptotic cell death and upregulates COX-2 expression
Simultaneous quasi-periodic optical and HF radar signatures observed in the postnoon sector
Zhongshan Station in Antarctica is located close to the polar cusp/cleft latitude. The field of view of the Syowa East HF radar also covers Zhongshan Station. Simultaneous quasi-periodic phenomena of optical aurora, HF radar backscatter power and Doppler velocity, and ground based magnetograms were observed in the magnetic postnoon sector (~330 MLT to 1510 MLT) on 3 August 1997. The characteristics of the quasi-periodic event are summarized in the following; 1) East-west aligned band/arc type discrete aurora showed quasi-periodic luminosity variations with period of -6-10 min, 2) Quasi-periodic variations of the optical aurora had one to one correspondence with the variations of HF radar backscatter powers and magnetic pulsations, 3) The HF backscatter region was located at the lower latitude of the quasi-periodic optical aurora, 4) Quasi-periodic variations of line-of-site Doppler velocity detected by HF radar showed very close relation to the magnetic pulsations observed at Zhongshan in Antarctica and the IMAGE magnetometer array in the northern hemisphere, 5) The IMAGE data revealed that the region of quasi-periodic HF radar backscatter (irregularities) corresponds to the region of intensity maximum of magnetic pulsations
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