The transesterification of molten ethylene-vinylacetate (EVA) copolymers by octanol with sodium methoxide as catalyst in an extruder has been monitored by on-line near infrared (NIR) spectroscopy. A total of 60 NIR spectra were acquired for 37 min with the last spectrum recorded 31 min after the addition of octanol and catalyst was stopped. The experimental spectra show strong baseline fluctuations which are corrected for by multiplicative scatter correction (MSC). The chemometric methods of the orthogonal projection approach (OPA) and multivariate curve resolution (MCR) were used to resolve the spectra and to derive concentration profiles of the species. The detailed analysis reveals the absence of completely pure variables which leads to small errors in the calculation of pure spectra. The initial estimation of a concentration that is necessary as an input parameter for MCR also presents a non-trivial task. We obtained results that were not ideal but applicable for practical concentration control. They enable a fast monitoring of the process in real-time and resolve the spectra of the EVA copolymer and the ethylene-vinyl alcohol (EVAL) copolymer to be very close to the reference spectra. The chemometric methods used and the decomposed spectra are discussed in detail.

Journal Article↗

PubMed2000

Clonal expansion of T cells infiltrating in the airways of non-atopic asthmatics.

CD4+ T cells are thought to play an important role in airway inflammation in both atopic and non-atopic asthma. However, the mechanism by which T cells are activated in non-atopic asthma, where there is no causative antigen identified, is unknown. To elucidate this issue, we analysed T cell receptor (TCR) Vbeta gene clonotypes of T cells in the bronchoalveolar lavage fluids (BALF) of non-atopic asthmatics using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis and a sequencing method. We found that the numbers of TCR Vbeta gene clonotypes of T cells in the BALF of non-atopic asthmatics were significantly increased compared with those of peripheral blood lymphocytes (PBL). We also found that there were several shared amino acid motifs in complementarity-determining region 3 (CDR3) of TCR Vbeta genes from those T cell clones in BALF of non-atopic asthmatics, whereas these shared motifs were not found in the same Vbeta family genes from PBL in the patients. Moreover, a conserved amino acid sequence was detected in two patients who shared a common HLA-DR allele. These results indicate that the infiltrating T cells in the airways of non-atopic asthmatics recognize relatively limited epitopes of antigens and are clonally expanded by antigen-driven stimulation.

Adult↗

PubMed2000

Improving public awareness of organ transplantation in Japan.

The goals of the Japanese chapter of the Transplant Recipients International Organization are to act as a mediator in the provision of mutual aid to transplant recipients, candidates, and their families and to provide education in both the public and professional arenas to promote organ transplantation in Japan. Since 1991, members of the Japanese chapter of the Transplant Recipients International Organization have acted as volunteer facilitators for more than 150 transplant candidates and recipients. The organization's activities have included fund-raising to cover the costs of transplantation, preparing an original donor card for distribution, and petitioning members of the Diet (the Japanese legislative body) 14 times, including speaking at public hearings twice and submitting a petition requesting early passage of the organ transplant bill. The Japanese Diet finally passed an organ transplant bill in June 1997. The activities of the Japanese chapter of the Transplant Recipients International Organization have contributed to the promotion of organ transplantation in Japan and to understanding and support for transplantation within the Japanese community as a whole.

Attitude to Health↗