采用无偏振片反射式LCD及超低功耗驱动技术制造移动显示器件

我们通过对材料和制备条件的精细化处理,生产出一种在低刷新频率下无闪烁和图像迟滞现象的反射式显示器。该显示器的功耗非常低,且可在宽温度范围内工作,是未来移动显示器件的潜力平台。     

A chimeric inorganic pyrophosphatase derived from Escherichia coli and Thermus thermophilus has an increased thermostability

Factors contributing to the thermostability of inorganic pyrophosphatase (PPase) were investigated by examining chimeric PPases from Escherichia coli and Thermus thermophilus (Tth). Two chimeric PPase genes, T1-135E (residues 1-135 from the N terminus are comprised of Tth PPase and residues 136-173 are derived from the C terminus of E. coli PPase) and T1-149E [residues 1-149 from the N terminus are from Tth PPase and the rest (150-175) are from E. coli PPase], were constructed by random chimeragenesis. After the genes were overexpressed in the E. coli BL21(DE3) strain and the expression products were purified, we compared the characteristics of these chimeric PPases with those of the parental PPases. We found that the two chimeras had higher activity than either parent PPase at the optimum temperature. We also examined thermal stability in terms of CD spectra, fluorescence spectra, and thermal changes in enzyme activity. The results revealed that the thermal stability of T1-149E is similar to that of Tth PPase, but T1-135E is much more stable. This suggests that the four residues that are different between T1-135E and T1-149E may be critical for thermostability between the two chimeras. By comparing the three-dimensional structures of Tth and E. coli PPases, we deduced that the following two factors may contribute to differences in thermostability. (1) Two residues (Thr138 and Ala141 in the Tth PPase and His140 and Asp143 in the E. coli PPase) in the vicinity of the trimer-trimer interface were different. (2) The Ala144-Lys145 loop in the Tth PPase was deleted in the E. coli PPase and also in the T1-135E chimera. Therefore, we conclude that T1-135E was thermostabilized by these two factors, and also, the Tth PPase moiety may contribute to the structural integrity of the chimeric enzymes.     

New assay for rhizobitoxine based on inhibition of 1-aminocyclopropane-1-carboxylate synthase

Rhizobitoxine is synthesized by the legume symbiont Bradyrhizobium elkanii and the plant pathogen Burkholderia andropogonis. Rhizobitoxine competitively inhibited 1-aminocyclopropane-1-carboxylate (ACC) synthase bLE-ACS2 from the tomato, a key enzyme in the pathway of ethylene biosynthesis. Based on this inhibition of ACC synthase, we have developed a new assay for rhizobitoxine.     

Characterization of matched systems

A new principle of control system design called matching was recently introduced by Zakian. The principle requires the designer to choose a controller which makes a system match its environment. Characterization of matched controllers by means of Youla parameterization is discussed in this paper. Sufficient conditions for matching are given in the form of inequality constraints on the norm of the free parameters in the parametrizations based on nominal matched controllers.     

Augmented proliferation of human alveolar macrophages after allogeneic bone marrow transplantation

After allogeneic bone marrow transplantation (allo-BMT), recipient alveolar macrophages (AM) are gradually replaced by AM of the donor origin. An influx of mononuclear phagocytes of donor origin to the lung is responsible for the repopulation, but the detailed kinetics remain unclear. We therefore studied 24 BMT recipients who underwent bronchoalveolar lavage (BAL) from 24 to 83 days after BMT. AM cell number, size, morphology, proliferating ability, and genotype of AM were measured. Before day 50, the number and size of AM in BAL fluid were similar to those of normal nonsmokers. However, after day 50, the mean number of AM increased threefold and the mean cell size decreased due to the increase of small AM. These small cells are presumably of donor origin based on DNA fingerprinting analysis and based on fluorescence in situ hybridization for the Y chromosome in a sex-mismatched case. Immunohistochemistry and cell cycle analysis demonstrated that the increase in AM number coincided with a remarkable increase of AM expressing proliferating cell nuclear antigen, suggesting that small AM are proliferating. This is the first report representing that augmented proliferation of donor AM in situ may contribute to the reconstitution of AM population after BMT.     

Quantitative differences in the active-site hydrophobicity of five human glutathione S-transferase isoenzymes: water-soluble carcinogen-selective properties of the neoplastic GSTP1-1 species

The active-site (the H-site) hydrophobicity of five human glutathione S-transferases (GSTs) was analyzed by application of linear free energy relationships (LFERs) with a series of S-alkylated glutathione inhibitors, GS(CH2)n - 1CH3 (n = 1-14). Distinct linear reltionships were observed in the plots of log Ki (inhibition constant) vs n for the five forms, whereby the Kis varied by three to four orders of magnitude. Mean free enthalpy changes per methylene group (-Delta DeltaG degreess), a measure of H-site hydrophobicity, were in the order M1-1 (4.6 kJ/mol) > A1-1 (3. 9 kJ/mol) > A1-2 (3.8 kJ/mol) > A2-2 (2.8 kJ/mol) > P1-1 (1.6 kJ/mol). The quantitative differences may in part account for the extraordinary broad and overlapping substrate specificities of the Alpha-, Mu-, and Pi-class isoenzymes. In contrast to the Alpha and Mu classes being selective for strongly electrophilic compounds, the neoplastic P1-1 species was indicated to be selective for weakly electrophilic and water-soluble carcinogens such as acrolein and hydroxyalkenals.     

Vascular endothelial growth factor enhances vascularization in microporous small caliber polyurethane grafts

Neoarterial regeneration in an implanted small caliber vascular prosthesis is complexly controlled by many structural and biologic factors, such as cytokines. The authors designed an artificial graft, which was prepared as follows. Segmented polyurethane tubular film (inner diameter, 1.5 mm; wall thickness, 100 microns; length, 20 mm), in which micropores (pore size, 100 microns) were fabricated by an excimer laser ablation technique, were coated with a mixed solution of photoreactive gelatin and heparin with or without cytokines (vascular endothelial growth factor [VEGF]: 5 or 50 micrograms/ml, basic fibroblast growth factor [bFGF]: 1 microgram/ml). These coated grafts were irradiated by ultraviolet light, and were implanted in aortas of rats for 4 weeks; the VEGF (5 micrograms/ml) group, n = 6; the bFGF group, n = 6; the VEGF (5 micrograms/ml)/bFGF group, n = 11; the VEGF (50 micrograms/ml)/bFGF group, n = 5; and the control group, n = 9. Control grafts were treated without cytokines. Endothelial coverage was greater for the cytokine immobilized groups (approximately equal to 50-60%) than for the control group (approximately equal to 30%). At the midportion of the triple VEGF immobilized group, many capillaries were seen in the neoarterial intima, and in the micropores, although such capillaries were rarely observed in the bFGF and control groups. Thus, impregnation of VEGF in the gelatinous layer of grafts enhanced transanastomotic tissue ingrowth and transmural capillary ingrowth.