Long-term follow-up (8 to 17 years) after thromboexclusion operation for thoracic aortic aneurysms

Forty-eight Russell's viper bite patients (40 males, 8 females), age ranging from 16-76 years were studied. Out of 48 patients, 14 were found to have a prolonged whole blood clotting time test (WBCT) (i.e. incoagulable blood) (Group 1); 23 had a normal WBCT (i.e. clotted blood) (Group II); and 11 patients had a normal WBCT on admission which changed to non-clotting during the clinical course (Group III). Four patients from group I developed hypotension and 2 expired. The serum cortisol concentration (mean +/- SEM) on admission among groups I and II were 639 +/- 45.6 and 424 +/- 33.2 nmol/l respectively. The blood cortisol level in 35 subjects (controls) were 370.7 +/- 17.7 nmol/l (mean +/- SEM). There was a significant rise of blood cortisol in patients with incoagulable blood when compared to controls at the time of admission to the hospital (p < 0.05); but there was no significant difference among those patients with clotted blood. A much higher mean serum cortisol level was observed in 4 patients with hypotension as compared to 10 patients without shock. These patients with hypotension according to our study shown to have a favorable response to steroid therapy and eventually recovered. Whether higher doses of steroid in addition to antiserum confer extra benefit in suppressing nonspecific venom effects on the pituitary and/or adrenal is not known.     

Analysis of XANES for identification of highly dispersed transition metal oxides on supports

XANES of vanadium and niobium oxide on silica or alumina have been analyzed quantitatively by a deconvolution technique. Based on the results for reference compounds, local structures of supported vanadium and niobium species were identified. The composition was estimated from difference spectra for the samples which consisted of two kinds of species.     

Evidence that angiotensin II, endothelins and nitric oxide regulate mitogen-activated protein kinase activity in rat aorta

We measured the activity of mitogen-activated protein (MAP) kinases, enzymes believed to be involved in the pathway for cell proliferation, in rat aortic strips with or without endothelium, and examined effects of angiotensin receptor antagonists, endothelin receptor antagonists and nitric oxide (NO)-related agents. Endothelium removal produced an activation of MAP kinase activity in the strips, whereas the enzyme activity was not affected in the adventitia. The MAP kinase activation was inhibited by either the angiotensin AT1 receptor antagonist losartan or the endothelin ETA receptor antagonist BQ 123. The combination of both antagonists caused an additive inhibition. The angiotensin AT2 receptor antagonist PD 123,319 and the endothelin ETB receptor antagonist BQ 788 did not affect the MAP kinase activation. The NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) caused an activation of MAP kinase in the endothelium-intact aorta and the MAP kinase activation was inhibited by losartan or BQ123. The NO releaser nitroprusside inhibited the MAP kinase activation induced by endothelium removal or angiotensin II. These results suggest that even in isolated arteries, NO of endothelial origin tonically exert MAP kinase-inhibiting effects and endogenous angiotensin II and endothelins in the media are tonically released to cause MAP kinase-stimulating effects in medial smooth muscle.     

A free dendritic growth model accommodating curved phase boundaries and high peclet number conditions

A steady-state free dendrite growth model accommodating nonlocal equilibrium tip conditions and curved liquidus and solidus has been developed. The developed model assumes a dendrite tip of a paraboloid of revolution and is applicable to dendrite growth in dilute binary alloys for all values of P _c , and reduces to the BCT model for linear liquidus and solidus. The marginal stability criterion of Trivedi and Kurz is shown to apply even in the presence of kinetic undercooling and curved phase boundaries when used with an appropriate concentration-dependent liquidus slope. The model is applied to Sn-Pb alloys to predict the tip velocity, tip radius, solute trapping, and four components of undercooling in the quasi-solutal, solutal-to-thermal transition and quasi-thermal regions.     

Novel UV absorbers prepared from 2,4-dihydroxybenzophenone and hexachlorocyclotriphosphazene

The UV-stabilizing ability and thermal loss from the polystyrene film of novel UV absorbers, 2-[(3-hydroxy-4-benzoyl) phenoxy] pentachlorocyclotriphosphazene (HBPC) and hexakis[ (2-hydroxy-4-benzoyl) phenoxy] cyclotriphosphazene (HBPP), were investigated. The UV-stabilizing ability of HBPC estimated by the formation of carbonyl groups in polystyrene was comparable to that of 2,4-dihydroxybenzophenone (DHB), suggesting that the phosphazene moiety does not affect the efficiency of the stabilizing ability of DHB units. No significant difference of efficiency per stabilizing units between HBPC and HBPP was observed. HBPC and HBPP are noteworthy for their low thermal losses from the polystyrene film, i.e., the thermal loss of HBPP was completely suppressed and the diffusion coefficient of HBPC at 160°C was two orders of magnitude smaller than that of DHB. The thermogravimetric analysis and differential scanning calorimetry measurement showed that HBPC and HBPP are nonvolatile and stable up to 230 and 300°C, respectively. © 1993 John Wiley & Sons, Inc.     

Tensile properties and plastic deformation modes ofβ Zr-Nb alloys

Tensile properties and plastic deformation modes of zirconium-niobium alloys were investigated at 290 and 77 K in the wide composition range from metastable to stable phase. Three types of plastic deformation modes, {332}113 twinning, {112}111 twinning and slip, were observed depending on alloy composition and temperature. {332}113 twinning, which occurs in metastable zirconium alloys, is related to the stability of phase to decomposition and leads to low yield stress and large elongation. On the other hand, {112}111 twinning, which appears in stable zirconium alloys, results from high critical stress for slip due to solution hardening and high Peierls stress and does not affect tensile properties significantly. The results obtained for zirconium-alloys are similar to those for titanium alloys, strongly suggesting that {332}113 twinning is an important plastic deformation mode which is common to phase alloys containing athermal phase.     

Effects of temperature and grain size on deformation and fracture in recrystallized Ni3Al doped with boron

The effects of temperature and grain size on the deformation and fracture behaviour of recrystallized Ni₃Al doped with boron were investigated by tensile tests at temperatures up to 973 K as a function of grain sizes from 1.6 to 105m. The yield stress showed a positive temperature dependence to a peak temperature in somewhat different manners depending on the grain size. For coarse-grained specimens, a rapid drop in elongation was observed with increasing temperature. The predominant fracture mode changed with temperature from the transgranular fracture of {1 1 1} cracking to brittle intergranular fracture. This embrittlement at elevated temperatures was considered to occur by a high stress concentration at grain boundaries arising from increased flow stress level and the occurrence of grain boundary sliding (GBS). In contrast, the elongation was not so markedly decreased with temperature for intermediate- and fine-grained specimens which exhibited ductile intergranular fracture and cavitation fracture, respectively, at elevated temperatures, and a slant-type fracture and cup-cone fracture, respectively, at low temperatures. The suppression of serious high-temperature embrittlement for intermediate-grained specimens was explained in terms of the slow propagation of a crack formed by GBS, owing to stress relaxation by dynamic recrystallization (DR) and plastic deformation. In the case of ultra-fine-grained specimens a large elongation was developed at elevated temperatures, which was interpreted as that the further occurrence of DR with increasing volume fraction of grain boundaries reduces the cavitation promoted by GBS, and that the limited sliding length due to extremely small grain diameter raises the stress for cavity formation.     

Identification of SYS1 as a Host Factor Required for Shiga Toxin-Mediated Cytotoxicity in Vero Cells

Shiga toxin (STx) or Vero toxin is a virulence factor produced by enterohemorrhagic Escherichia coli. The toxin binds to the glycosphingolipid globotriaosylceramide (Gb3) for its entry, and causes cell death by inhibiting ribosome function. Previously, we performed a loss-of-function screen in HeLa cells using a human CRISPR knockout (KO) library and identified various host genes required for STx-induced cell death. To determine whether this library targeted to the human genome is applicable to non-human primate cells and to identify previously unrecognized factors crucial for STx-induced cell death, we herein performed a similar screen in the African green monkey kidney-derived Vero C1008 subline. Many genes relevant to metabolic enzymes and membrane trafficking were enriched, although the number of enriched genes was less than that obtained in the screening for HeLa cells. Of note, several genes that had not been enriched in the previous screening were enriched: one of these genes was SYS1, which encodes a multi-spanning membrane protein in the Golgi apparatus. In SYS1 KO Vero cells, expression of Gb3 and sphingomyelin was decreased, while that of glucosylceramide and lactosylceramide was increased. In addition, loss of SYS1 inhibited the biosynthesis of protein glycans, deformed the Golgi apparatus, and perturbed the localization of trans-Golgi network protein (TGN) 46. These results indicate that the human CRISPR KO library is applicable to Vero cell lines, and SYS1 has a widespread effect on glycan biosynthesis via regulation of intra-Golgi and endosome–TGN retrograde transports.     

Morphology and preferred orientation of Y2O3 film prepared by high-speed laser CVD

Yttria (Y₂O₃) films were prepared at high deposition rates of up to 83 nm/s (300 μm/h) by laser chemical vapor deposition (LCVD) using an Y(dpm)₃ precursor. The effects of deposition conditions, mainly total gas pressure and laser power, on morphology, deposition rate and preferred orientation were studied. Plasma was produced around the substrate over a critical laser power resulting in significant increases in deposition temperature and deposition rate. The high deposition rate (300 μm/h) by LCVD was about 100 to 1000 times as high as those by conventional CVD. The morphology of Y₂O₃ films changed from faceted and columnar structures with high (400) orientation to a columnar structure with high (440) orientation, and finally to a cone-like structure with moderate (440) orientation with increasing total gas pressure (P_tot).