The Flameretardant Study of PVA Using for Corrugated Cardboard

AbstractCorrugated cardboards have truss structure, so these have advantageous in terms of specific strength, workability, price and recycling efficiency. For these properties, corrugated cardboards are used as packing materials. In this research We tried to study about the flameretardancy (FR) of a corrugated cardboards using for Poly(vinyl alcohol) (PVA). The coating PVA on the cardboard is possible to be recyclable, because PVA has water solubility. Also the reason using PVA is to protect from the toxicity of flameretardant, which is used to the cardboards. We studied the FR-PVA for different with decomposition point of FR agent. We measured TGA and combustion test of the PVA. In the result, we could get the flameretardancy of PVA

Increased endothelial and epidermal thrombomodulin expression and plasma thrombomodulin level in progressive systemic sclerosis.

To clarify the relation between systemic and cutaneous vascular endothelial injury in progressive systemic sclerosis (PSS), we examined thrombomodulin (TM) expression in PSS skin lesions immuno-histopathologically and compared it with plasma soluble TM levels measured by specific enzyme-linked immunosorbent assay. The plasma soluble TM level in PSS patients was significantly higher than that of normal controls and was as high as the levels of SLE patients. In relation to disease activities, the plasma TM levels of sclerotic phase PSS patients were significantly higher than that of atrophic phase PSS patients. The plasma samples with anti-Scl-70 antibody showed a high TM level than samples with anti-centromere antibody or anti-RNP antibody. Barnett's types or systemic corticosteroid treatment did not affect the TM level. Histopathologically, the dermal endothelial TM expression significantly increased in the sclerotic skin and moderately increased in the non-sclerotic skin of PSS compared with that of normal control skin. In addition, immunoreactive TM expression in the epidermis also increased in PSS. Disease activity-dependent elevation of plasma TM levels and immuno-histopathological expression of TM suggested generalized endothelial and epidermal cell involvement in PSS, and compensation in part by overproduction of TM by endothelial cells.</p

Selected Mutations in a Mesophilic Cytochrome c Confer the Stability of a Thermophilic Counterpart

Mesophilic cytochrome c551 of Pseudomonas aeruginosa (PA c551) became as stable as its thermophilic counterpart, Hydrogenobacter thermophilus cytochrome c552 (HT c552), through only five amino acid substitutions. The five residues, distributed in three spatially separated regions, were selected and mutated with reference to the corresponding residues in HT c552 through careful structure comparison. Thermodynamic analysis indicated that the stability of the quintuple mutant of PA c551 could be partly attained through an enthalpic factor. The solution structure of the mutant showed that, as in HT c552, there were tighter side chain packings in the mutated regions. Furthermore, the mutant had an increased total accessible surface area, resulting in great negative hydration free energy. Our results provide a novel example of protein stabilization in that limited amino acid substitutions can confer the overall stability of a natural highly thermophilic protein upon a mesophilic molecule.This work was supported by a grant from the Japanese Ministry of Education, Science and Culture

Stabilization of Pseudomonas aeruginosa Cytochrome c551 by Systematic Amino Acid Substitutions Based on the Structure of Thermophilic Hydrogenobacter thermophilus Cytochrome c552

A heterologous overexpression system for mesophilic Pseudomonas aeruginosa holocytochrome c551 (PA c551) was established using Escherichia coli as a host organism. Amino acid residues were systematically substituted in three regions of PA c551 with the corresponding residues from thermophilic Hydrogenobacter thermophilus cytochrome c552 (HT c552), which has similar main chain folding to PA c551, but is more stable to heat. Thermodynamic properties of PA c551 with one of three single mutations (Phe-7 to Ala, Phe-34 to Tyr, or Val-78 to Ile) showed that these mutants had increased thermostability compared with that of the wild-type. Ala-7 and Ile-78 may contribute to the thermostability by tighter hydrophobic packing, which is indicated by the three dimensional structure comparison of PA c551 with HT c552. In the Phe-34 to Tyr mutant, the hydroxyl group of the Tyr residue and the guanidyl base of Arg-47 formed a hydrogen bond, which did not exist between the corresponding residues in HT c552. We also found that stability of mutant proteins to denaturation by guanidine hydrochloride correlated with that against the thermal denaturation. These results and others described here suggest that significant stabilization of PA c551 can be achieved through a few amino acid substitutions determined by molecular modeling with reference to the structure of HT c552. The higher stability of HT c552 may in part be attributed to some of these substitutions.This work was supported in part by grants from the Japanese Ministry of Education, Science and Culture

Development of a handy oil-skimmer

金沢大学大学院自然科学研究科環境創成金沢大学工学部Recently marine-pollution by high-viscous oil leaked from wrecked ships has been becoming a remarkable problem in the world. Japan government is renewing old oil recovery vessels with new concept. The oil recovery vessels are available on the open sea, but unworkable in a narrow space. We have developed a handy oil recovery system which is portable and used for supplementing the weak point of the oil recovery vessel. The system consists of a water jet oil-skimmer and a gravity oil/water separator. The oil skimmer has a high-pressure water jet pump inside the suction mouth and a long shaft which is used as a conduit of the recovered fluid as well as a spring-hanging device which enables an operator to easily manipulate it from the deck of the ship. After 3-year research and experiments, we have completed the system successfully. The system will be soon installed on our oil recovery vessels. © 2004 IEEE

Development of recombinant nucleoprotein-based diagnostic systems for lassa fever

Diagnostic systems for Lassa fever (LF), a viral hemorrhagic fever caused by Lassa virus (LASV), such as enzyme immunoassays for the detection of LASV antibodies and LASV antigens, were developed using the recombinant nucleoprotein (rNP) of LASV (LASV-rNP). The LASV-rNP was expressed in a recombinant baculovirus system. LASV-rNP was used as an antigen in the detection of LASV-antibodies and as an immunogen for the production of monoclonal antibodies. The LASV-rNP was also expressed in HeLa cells by transfection with the expression vector encoding cDNA of the LASV-NP gene. An immunoglobulin G enzyme-linked immunosorbent assay (ELISA) using LASV-rNP and an indirect immunofluorescence assay using LASV-rNP-expressing HeLa cells were confirmed to have high sensitivity and specificity in the detection of LASV-antibodies. A novel monoclonal antibody to LASV-rNP, monoclonal antibody 4A5, was established. A sandwich antigen capture (Ag-capture) ELISA using the monoclonal antibody and an anti-LASV-rNP rabbit serum as capture and detection antibodies, respectively, was then developed. Authentic LASV nucleoprotein in serum samples collected from hamsters experimentally infected with LASV was detected by the Ag-capture ELISA. The Ag-capture ELISA specifically detected LASV-rNP but not the rNPs of lymphocytic choriomeningitis virus or Junin virus. The sensitivity of the Ag-capture ELISA in detecting LASV antigens was comparable to that of reverse transcription-PCR in detecting LASV RNA. These LASV rNP-based diagnostics were confirmed to be useful in the diagnosis of LF even in institutes without a high containment laboratory, since the antigens can be prepared without manipulation of the infectious viruses.Instituto de Biotecnologia y Biologia Molecula