TNF/TNFR gene and apoptosis

Intracellular signal transduction pathways induced by in the reaction of TNF and TNF receptors has been clarified through finding of various TNF receptor associated intracytoplasmic molecules. The possible role of these signal transduction pathways for apoptosis induced by TNF is discussed.     

Eel ventricular natriuretic peptide: isolation of a low molecular size form and characterization of plasma form by homologous radioimmunoassay

In order to determine the relation between myocardial fibrosis and (1) angiotensin converting enzyme (ACE) binding density, (2) receptor binding of ACE-related peptides, angiotensin II (AngII) and bradykinin (BK), and (3) the regulation of myocardial ACE by circulating Ang II, we used in vitro quantitative autoradiography to localize and assess ACE ([125I]351A), AngII receptor (125I[Sar1, IIe8]AngII), and BK receptor ([125I]Tyr8) binding densities in the rat myocardium. The experimental groups were (1) AngII (9 micrograms/h subcutaneously) or aldosterone (0.75 microgram/h subcutaneously in uninephrectomized rats on a high-sodium diet) administered by implanted minipump to chronically increase or decrease circulating AngII, respectively, (2) unoperated, untreated age- and sex-matched control rats, and (3) age- and sex-matched uninephrectomized control rats on a high-sodium diet. In the same heart studied at 2, 4, and 6 weeks of hormone treatment, serial sections were assessed for myocardial (hematoxylin and eosin) and fibrillar collagen (picrosirius red) morphology. The authors found that (1) marked ACE binding was coincident with sites of fibrous tissue that appeared in both ventricles as either a perivascular fibrosis of intramyocardial coronary arterioles or microscopic scarring in response to AngII or aldosterone infusion, (2) ACE binding was independent of circulating AngII, (3) BK, not AngII, receptor binding density was markedly increased at fibrous tissue sites, and (4) high-density ACE and BK receptor binding were anatomically coincident. Thus, in these experimental models, ACE is related to fibrous tissue formation where it may use BK, not angiotensin I, as a substrate, and its binding density is independent of circulating AngII.     

Evaluation of a particle trap laser desorption mass spectrometer (PT-LDMS) for the quantification of sulfate aerosols

A particle trap laser desorption mass spectrometer (PT-LDMS) has been developed for the online measurements of the chemical composition of submicron aerosol particles. The PT-LDMS was evaluated by both laboratory and ambient measurements, with the focus being the quantification of sulfate aerosols. Ammonium sulfate ((NH₄)₂SO₄) is generally the predominant form of sulfate aerosols in urban air; hence, it is used as a material for laboratory experiments and calibration. Major fragments of (NH₄)₂SO₄ were observed at mass-to-charge ratios (m/z) of 48 (SO⁺) and 64 (SO₂⁺). The dependence of sensitivity (expressed as the ratio of m/z 48 signal to sulfate mass) on laser power and cell temperature was investigated. An intercomparison of PT-LDMS with a commercial sulfate particle analyzer (SPA) and filter sampling was performed in Tokyo. Good agreement was observed between SPA and filter analysis (slope = 0.98, r² = 0.99). Although the mass concentration of sulfate measured by PT-LDMS exhibited a tight correlation with that measured by SPA, the mass concentration measured by PT-LDMS tended to underestimate that measured by SPA (slope = 0.70, r² = 0.96). While the discrepancy can be mainly attributed to the difference in size cut between PT-LDMS (approximately PM₁) and SPA (PM_2.5), differences in vaporization efficiency were also found to be important.

Copyright © 2016 American Association for Aerosol Research     

DEVELOPMENT OF AN ADAPTIVE STEREOSCOPIC-PIV SYSTEM FOR ANALYSIS OF THE FLOW-STRUCTURE INTERACTIONS (FSI) OF AIR-LIFTED BODIES

An adaptive stereoscopic-PIV system has been constructed for flow analyses around a cylinder body (length = 60 mm, diameter = 10 mm, polystyrene). The body is floated by the swirling flows in a vertical pipe with a length of 1100 mm and an inner diameter of 100 mm. Four optical sensors (LEDs) were installed onto the pipe wall to detect the posture of the cylinder body. The constructed stereoscopic-PIV system is activated by the signals of the optical sensors when the cylinder is in the upright posture. The measurement system consists of two cameras, a Nd-Yag laser, and a host computer. Flow characteristics around the floating cylinder body and the motional characteristics of the body itself are investigated when the body is in the upright posture. It has been verified that the motion of the floating cylinder becomes stable when the azimuthal velocity component (W component) of the swirl flow is maintained at stable states.     

Pulsed electric current sintering of transparent Cr-doped Al2O3

Pulsed electric current sintering (PECS) was applied to obtain transparent ruby polycrystals. Al₂O₃-Cr₂O₃ powder mixture was prepared by drying an aqueous slurry consisting of Al₂O₃ and Cr(NO₃)₃ followed by PECS consolidation in vacuum at a sintering temperatures ranging from 1100 to 1300 °C with various heating rates between 2 and 100 °C/min and under an applied pressures from 40 to 100 MPa. Slow heating rate and high-pressure lead to highly densified and transparent Cr-doped Al₂O₃ polycrystals at sintering temperature of 1200 °C.     

Evaluation of a New Particle Trap in a Laser Desorption Mass Spectrometer for Online Measurement of Aerosol Composition

We have developed a new analyzer for the online measurement of aerosol composition: a particle trap laser desorption mass spectrometer (PT-LDMS). The main components of the instrument include an aerodynamic lens, a particle trap enclosed by a quartz cell, a quadrupole mass spectrometer (QMS), a vacuum chamber incorporating the above components, and a carbon dioxide (CO₂) laser (wavelength 10.6 μm). The aerodynamic lens generates a beam of submicron particles, which is focused on a small area on the particle trap. The particle trap consists of custom-made mesh layers, the structure of which was newly designed using engineering techniques for micro electro mechanical systems (MEMS). A large number of mesh frames are well arranged in the trap, and particles can be efficiently captured after multiple impactions on the frames. The CO₂ laser is used to vaporize aerosol compounds captured on the particle trap. The evolved gas confined within the quartz cell is analyzed using an electron impact ionization (EI) QMS to quantify the chemical composition of the particles. The concept of the PT-LDMS and first evaluation of its performance are presented, specifically focusing on the structure and performance of the particle trap.     

Vitreous phase coating on glaserite-type alkaline earth silicate blue phosphor BaCa2MgSi2O8:Eu

A simple solid-state reaction was used to apply a vitreous-phase coating onto Eu²⁺-doped BaCa₂MgSi₂O₈ blue-phosphor particles. The vitreous phase was generated by liquid phase sintering at 1200 °C. The coated phosphor exhibited resistant to an acid dispersant. When a small amount of Al and La was added in raw materials, they were incorporated in the vitreous coating phase.     

Preparation of polymeric microcapsules enclosing microbial cells by radical suspension polymerization via water-in-oil-in-water emulsion

Polymeric microcapsules enclosing Saccharomyces cerevisiae were prepared by radical suspension polymerization via water-in-oil-in-water emulsion. Trimethylolpropane trimethacrylate and 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) were used as monomer and radical initiator, respectively. A culture medium with suspended yeast cells, monomer solution with the dissolved radical initiator, and poly(vinyl alcohol) aqueous solution were used as inner aqueous phase, oil phase, and outer aqueous phase, respectively. The influence of microcapsule preparation parameters on the viability of encapsulated cells and encapsulation efficiency was investigated. The radical polymerization process did not cause significant damage to encapsulated yeast cells. Decreased weight ratio of aqueous phase to oil phase resulted in increased encapsulation efficiency of the cells. The diameter of the microcapsules could be controlled by varying the agitation rate.     

Anammox Bacterial S-Adenosyl-l-Methionine Dependent Methyltransferase Crystal Structure and Its Interaction with Acyl Carrier Proteins

Ladderane lipids (found in the membranes of anaerobic ammonium-oxidizing [anammox] bacteria) have unique ladder-like hydrophobic groups, and their highly strained exotic structure has attracted the attention of scientists. Although enzymes encoded in type II fatty acid biosynthesis (FASII) gene clusters in anammox bacteria, such as S-adenosyl-l-methionine (SAM)-dependent enzymes, have been proposed to construct a ladder-like structure using a substrate connected to acyl carrier protein from anammox bacteria (AmxACP), no experimental evidence to support this hypothesis was reported to date. Here, we report the crystal structure of a SAM-dependent methyltransferase from anammox bacteria (AmxMT1) that has a substrate and active site pocket between a class I SAM methyltransferase-like core domain and an additional α-helix inserted into the core domain. Structural comparisons with homologous SAM-dependent C-methyltransferases in polyketide synthase, AmxACP pull-down assays, AmxACP/AmxMT1 complex structure predictions by AlphaFold, and a substrate docking simulation suggested that a small compound connected to AmxACP could be inserted into the pocket of AmxMT1, and then the enzyme transfers a methyl group from SAM to the substrate to produce branched lipids. Although the enzymes responsible for constructing the ladder-like structure remain unknown, our study, for the first time, supports the hypothesis that biosynthetic intermediates connected to AmxACP are processed by SAM-dependent enzymes, which are not typically involved in the FASII system, to produce the ladder-like structure of ladderane lipids in anammox bacteria.