Randomized, double-blind, placebo-controlled study of ascorbate on the preventive effect of nitrate tolerance in patients with congestive heart failure

Mitogen-activated protein kinase (MAPK) is a serine-threonine kinase that is activated by various extracellular stimuli. Extracellular signal-regulated kinases (ERK1 and ERK2), an MAPK subfamily, are activated by many oncogenes, such as ras and raf, and they induce cell proliferation. myc is also an oncogene and one of the targets of ERKs. Mutations of ras and overexpression of myc were found in various human cancers, and ERKs were also reported to play a role in carcinogenesis. In this study, we examined 39 biopsy specimens of oral squamous cell carcinoma (OSCC) and 5 of normal gingival mucosa for the expression of ERK protein and the proliferation marker, MIB-1 (Ki-67 antibody). Thirteen OSCC specimens and five normal gingival biopsies were also examined for the expression of ERKs mRNA by in situ hybridization. Double staining for ERKs and MIB-1 was also performed. Histologically, 18 patients (46%) were diagnosed with well-differentiated SCC, 17 (44%) with moderately differentiated SCC, and 4 (10%) with poorly differentiated SCC. The histologic grade correlated with the MIB-1 index. The localization of ERK1 was similar to that of ERK2. Positive signals for ERK proteins were localized in superficial keratinocytes in normal gingival mucosa, whereas these mRNAs were weakly positive in the basal and spinous layer. Basal and suprabasal cells were positive for MIB-1. In well-differentiated and moderately differentiated OSCC, positive signals for ERK mRNA and proteins were found at higher levels than in normal gingival mucosa in keratotic cells around cancer pearls. Some cells showed positive signals for ERKs and MIB-1. Furthermore, most cancer cells in poorly differentiated SCC were positive for both ERK and MIB-1. The histologic grade was statistically related to the percentage of cells positive for both ERK and MIB-1. This suggested that ERKs might be related to proliferation in OSCC.     

Electrical resistivity of Mn-doped SnTe crystals at low temperature

The temperature dependence of the resistivity over the range 1.8–20 K has been measured on the narrow-gap semiconductor SnTe with various Mn contents (<2.2at.%) and carrier concentrations [p = (1.2–8) × 10²⁰ cm^–3]. The resistivity shows an anomaly at some magnetic ordering temperature T _m, which depends sublinearly on the Mn content c, but not linearly. However, together with a negative magnetoresistance, we have confirmed that the carrier scattering in this crystal is due to the s-d interaction as in dilute magnetic alloys.     

Planar Radiating Oscillator Using Butterfly-Shaped Patch Element and Spatial Power-Combining Array

A planar radiating oscillator using a butterfly-shaped patch element is described. To obtain an injection-locking range that can be changed and low cross-polarization, we used a butterfly-shaped patch. The patch element was able to change the injection-locking range while maintaining low cross-polarization, and two types of patch were compared. As one application, we designed and fabricated 1x2, 2x1 and 2x2 spatial power-combining arrays by using radiative mutual coupling. The 2x2 array was successfully operated with a single-bias supply without using a 3-D (three-dimensional) Fabry-Perot cavity. An equivalent isotropic radiated power of 2.5 W was measured at X-band.     

Theoretical analysis of laminar flow heat transfer in a flat-duct wall reactor

Conjugated heat transfer in steady state was studied, assuming the interfacial reaction to be instantaneous and the flow to be a fully-developed laminar condition. The thermal boundary condition at the outer surface of the duct wall is specified as the first kind or the third kind. Influences of the interfacial reaction, the conductance of the wall and the external convection on the heat transfer characteristics were found to be substantial through calculated numerical results of the interfacial temperature and the local Nusselt number. Cases with uniform interfacial heat source and without it were also examined under the third kind boundary condition.     

A novel method to prevent secondary exposure of medical and rescue personnel to toxic materials under biochemical hazard conditions using microwave radar and infrared thermography

In order to prevent secondary exposure of medical personnel to toxic materials under biochemical hazard conditions, we performed a noncontact determination of exposure to toxic conditions via 1215-MHz microwave radar and thermography. A toxic condition was induced by intravenous administration of lipopolysaccharide (LPS) in rabbits. The exposure to LPS was determined by linear discriminant analysis using non-contact derived variables.     

Photo-oxidation of lipids impregnated on the surface of dried seaweed (<Emphasis Type="Italic">Porphyra yezoensis</Emphasis> Ueda). Characterization of volatiles

Volatiles generated by the photo-oxidation of lipids applied to the surface of dried seaweed (Porphyra yezoensis Ueda) previously exposed to visible light were studied. The surface of dried seaweed was impregnated with eicosapentaenoic acid (EPA) ethyl ester or linoleic acid (LA) methyl ester. The sample was then divided into two parts, and each part was sealed in a 50-mL crimp-top vial with a PTFE silicone-lined cap. One vial was exposed to light from a 100-W tungsten bulb (6000 lux) in an oven at 45°C. The other vial was covered with aluminum foil to shield the seaweed from light and kept in the oven as a control. Volatile compounds in the headspace of the vials were collected by a solid-phase microextraction technique and analyzed by GC-FID and GC-MS. The numbers of peaks as well as the peak areas of volatiles in the light-exposed sample were much greater than those in the control in GC profiles obtained in the same oxidation period. The peak areas of volatiles changed with the prolongation of oxidation time, and the formation rates were different between volatiles. Approximately 28 volatiles were identified in the control kept in the dark as well as in the light-exposed sample impregnated with EPA ethyl ester. The relative amounts of propanal, 2-propenal, 1-penten-3-one, 1-penten-3-ol, 2-butenal, heptanoic acid, and 2-pentenal in the headspace of the light-exposed vials were significantly higher than those in the control, whereas the relative amounts of 3,5-octadien-2-one, ethyl butyrate, and 2,4-heptadienal in the control were significantly higher than those in the headspace of the light-exposed vial. Approximately 35 volatiles were identified from the dried seaweed impregnated with LA methyl ester. The relative amounts of hexanal, 2-heptenal, 2-octenal, octanoic acid methyl ester, and hexanoic acid in the headspace of the light-exposed vial were significantly higher than those in the control, and the relative amounts of 2-decenal, 2,4-nonadienal, and 2,4-decadienal in the control were significantly higher than those in the headspace of the light-exposed vial. We proposed the formation mechanisms of some volatiles to be the well-accepted homolytic-heterolytic cleavage of hydroperoxides that were generated by oxidation of the unsaturated lipids.     

Gene cloning and characterization of fructose-1,6-bisphosphate aldolase from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1

The fructose-1,6-bisphosphate (FBP) aldolase gene from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 was cloned. The gene encoding FBP aldolase (Tk-Fba) was expressed in Escherichia coli and the purified recombinant protein was characterized at high temperature. Tk-Fba is a homodecamer with a subunit molecular mass of 31,283 Da. The amino acid sequence, decameric conformation, formation of a Schiff-base intermediate, and stimulation (286%) of FBP cleavage activity by citrate suggested that Tk-Fba belonged to Class IA, a subtype of the classical Class I aldolases. The specific activity for the FBP cleavage reaction was 18.9 U/mg, which was much higher than those of other Class IA type FBP aldolases. Tk-Fba was extremely thermostable since the optimum temperature seemed to be above 100 degrees C. The optimum pH for Tk-Fba was determined to be 5.0 in the absence of citrate, while it shifted to around 7.0 in the presence of citrate. Tk-Fba accepted FBP and fructose-1-phosphate as substrates and K(m) values were determined to be 0.063 mM and 4.37 mM, respectively. In addition to citrate, phosphoenolpyruvate and pyrophosphate were also found to be potent activators of Tk-Fba, enhancing activities up to 346% and 201%, respectively. Erythrose-4-phosphate acted as an inhibitor and caused a decrease in the activity to 49%. Tk-Fba also catalyzed the condensation reaction with a similar activity level (14.9 U/mg) to that for FBP cleavage. However, none of the above compounds seemed to have a significant effect on the condensation reaction by Tk-Fba. These results suggest a regulatory function of Tk-Fba toward the catabolic direction of sugar metabolism in T. kodakaraensis KOD1.     

Elimination of a back-reflected TE mode in a TM-mode optical isolator with a Mach-Zehnder interferometer

Eimination of a back-reflected TE mode traveling in a TM-mode optical isolator was investigated. The optical isolator had a Mach-Zehnder interferometer that included a polarization-dependent reciprocal phase shifter in one of the arms. The reciprocal phase shift was achieved by an optical path difference between the two arms. By adjustment of the length of the reciprocal phase shifter, the interferometer prevented the back-reflected TE mode from coupling into an input port of the isolator. An extinction ratio of more than 18 dB was obtained against the back-reflected TE mode at a wavelength of 1.55 microm.     

Synthesis and properties of urethane elastomer-modified epoxy resin having hydroxymethyl group

Synthesis and properties of urethane elastomer-modified epoxy resins were studied. The urethane elastomer-modified epoxy resins were synthesized by the reaction of a 4-cresol type epoxy compound having hydroxymethyl groups (EPCDA) with isocyanate prepolymer. The structure was identified by IR, ¹H NMR and GPC. These epoxy resins (EPCDATDI) were mixed with a commercial epoxy resin (DGEBA) in various ratios. The mixed epoxy resins were cured with a mixture of 4,4′-diaminodiphenylmethane and 3-phenylenediamine (molar ratio 6:4) as a hardener. The curing behaviour of these epoxy resins was studied by DSC. The higher the concentration of EPCDATDI, the higher the onset temperature and the smaller the rate constant (k) of the exothermic cure reaction were. It was considered that the ratio of hydroxymethyl group to epoxide group was very small and the molecular weight of EPCDATDI was large. Therefore, the accelerating effect of the hydroxymethyl group on the epoxide–amine reaction was cancelled by the retardant effect of increased molecular weight and viscosity, and decreased molecular motion. Toughness was estimated by Izod impact strength and fracture toughness (K_1C). On addition of 10 wt% EPCDATDI with low molecular weight (M?_n 6710, estimated by GPC using polystyrene standard samples), Izod impact strength and K_1C increased by 70% and 60%, respectively, compared with unmodified epoxy resin. Glass transition temperatures (T_g) for the cured epoxy resins mixed with EPCDATDI measured by dynamic mechanical spectrometry were the same as those of unmodified epoxy resin. The storage modulus (E′) at room temperature decreased with increasing concentration of EPCDATDI. Toughness and dynamic mechnical behaviour of cured epoxy resin systems were studied based on the morphology.