Fourier Transform Infrared Emission Spectroscopy of the C4Delta-X4Phi, G4Phi-X4Phi, and G4Phi-C4Delta Systems of TiCl

The emission spectrum of TiCl has been investigated in the 3000-12 000 cm-1 region at high resolution using a Fourier transform spectrometer. The bands were excited in a microwave discharge through a flowing mixture of TiCl4 and helium. The observed bands have been classified into three electronic transitions, C4Delta-X4Phi, G4Phi-X4Phi, and G4Phi-C4Delta. In the 3000-3500 cm-1 region, four bands with R heads at 3368.7, 3331.8, 3291.9, and 3243.4 cm-1 have been assigned as the 0-0 bands of the 1/2-3/2, 3/2-5/2, 5/2-7/2, and 7/2-9/2 subbands, respectively, of the C4Delta-X4Phi transition. To higher wavenumbers, four transitions with 0-0 R heads at 10 930.7, 10 921.3, 10 906.5, and 10 886.9 cm-1 have been assigned as the 3/2-3/2, 5/2-5/2, 7/2-7/2, and 9/2-9/2 subbands, respectively, of the G4Phi-X4Phi system of TiCl. Four additional bands with 0-0 R heads at 7568.8, 7596.4, 7622.2, and 7651.7 cm-1 have been identified as the 1/2-3/2, 3/2-5/2, 5/2-7/2, and 7/2-9/2 subbands of the G4Phi-C4Delta transition, respectively. A rotational analysis of a number of vibrational bands of these transitions has been obtained and molecular constants have been extracted. The lowest 4Phi state has been assigned as the ground state of TiCl, by analogy with our recent work on TiF (R. S. Ram and P. F. Bernath, J. Mol. Spectrosc., in press). The correspondence between the electronic states of TiCl, TiF, TiH, and Ti+ is also discussed. Copyright 1997 Academic Press. Copyright 1997Academic Press     

4-丙基-4''''-氰基联苯的合成研究

以联苯为原料,经Friedel-Crafts反应、还原反应、碘代反应、氰化反应,合成4-丙基-4'-氰基联苯.此方法合成步骤少,操作简单,提纯方便,节省了费用.     

HOXD4 and regulation of the group 4 paralog genes

From an evolutionary perspective, it is important to understand the degree of conservation of cis-regulatory mechanisms between paralogous Hox genes. In this study, we have used transgenic analysis of the human HOXD4 locus to identify one neural and two mesodermal 3' enhancers that are capable of mediating the proper anterior limits of expression in the hindbrain and paraxial mesoderm (somites), respectively. In addition to directing expression in the central nervous system (CNS) up to the correct rhombomere 6/7 boundary in the hindbrain, the neural enhancer also mediates a three rhombomere anterior shift from this boundary in response to retinoic acid (RA), mimicking the endogenous Hoxd4 response. We have extended the transgenic analysis to Hoxa4 identifying mesodermal, neural and retinoid responsive components in the 3' flanking region of that gene, which reflect aspects of endogenous Hoxa4 expression. Comparative analysis of the retinoid responses of Hoxd4, Hoxa4 and Hoxb4 reveals that, while they can be rapidly induced by RA, there is a window of competence for this response, which is different to that of more 3' Hox genes. Mesodermal regulation involves multiple regions with overlapping or related activity and is complex, but with respect to neural regulation and response to RA, Hoxb4 and Hoxd4 appear to be more closely related to each other than Hoxa4. These results illustrate that much of the general positioning of 5' and 3' flanking regulatory regions has been conserved between three of the group 4 paralogs during vertebrate evolution, which most likely reflects the original positioning of regulatory regions in the ancestral Hox complex.     

Partial phase diagrams of the ternary systems NaCl-KCl-ZrCl4 and NaCl-KCl-HfCl4

Abstract

Fluoride emissions especially hydrogen fluoride from the aluminium smelting process present the potential for significant environmental damage and the care is, therefore, taken to remove them from the gas stream that leaves the plant. While previous work has focused on improving the scrubbing efficiency, more recent research has investigated the generation of fluoride emissions during the reduction process, in part to understand seasonal changes in fluoride emissions (summer syndrome). Several models have been developed to estimate the amount of hydrogen fluoride generated, but these do not consider the individual sources of fluoride generation and cannot be easily used to assess the impact of changes in relative humidity. This paper presents a new model, still under development, which simulates the hydrolysis of pot gas from an open feeder hole. During the course of this research, it has become clear that the major sources of moisture for hydrogen fluoride generation appear to be alumina, in the form of structural hydroxides and the ambient humidity. It is thought that summer syndrome can be explained by the changes in the ambient humidity. Initial results suggest that, in an open feeder hole, a 3000–5000 ppm hydrogen fluoride (HF) background in pot gas presents, the ambient moisture could account for 30–55% maximum of total HF emission, varying with ambient humidity, CO flaming and bath chemistry. However, the anode hydrogen and adsorbed alumina moisture only have limited contribution to the gaseous fluoride.     

Metabolism of 4-methylaminorex ("EU4EA") in the rat

Metabolism studies were conducted on 4-methylaminorex (4,5-dihydro-4-methyl-5-phenyl-2-oxazolamine [4-MAX]), a potent central nervous system stimulant that has emerged as a drug of abuse under the name "EU4EA", "EU4Euh", and "Ice". Tritiated norephedrine was cyclized with cyanogen bromide to form 3H-4-MAX, which was administered to rats at a dose of 10 mg/kg orally and intravenously. Radioactivity was excreted almost entirely in urine (40% of the dose was excreted by 24 h), primarily as the parent drug (60% of the total excretions were as the parent compound). Three metabolites were identified by high-performance liquid chromatography-tandem mass spectrometry with thermospray ionization: norephedrine, 5-phenyl-4-methyl-2-oxazolidinone, and 2-amino-5-(p-hydroxyphenyl)-4-methyl-2-oxazoline. Stability studies showed that 4-MAX in aqueous solution degraded very slightly to norephedrine upon standing. There was no evidence for glucuronide or sulfate conjugation. These results suggest that the metabolic fate of 4-MAX is similar to that of the amphetamines in that it is eliminated primarily unchanged but undergoes some slight oxidative deamination and aromatic hydroxylation. Hydrolytic degradation back to the synthetic precursor can also occur. There was no evidence for the hydrolysis of the oxazolamine ring to form a urea that has been reported for the demethylated congener aminorex. This suggests that 4-methyl substitution of the oxazoline ring may inhibit metabolism similar to the alpha-methyl substitution of beta-phenylethylamines.     

Mutations in the SMAD4/DPC4 gene in juvenile polyposis

Familial juvenile polyposis is an autosomal dominant disease characterized by a predisposition to hamartomatous polyps and gastrointestinal cancer. Here it is shown that a subset of juvenile polyposis families carry germ line mutations in the gene SMAD4 (also known as DPC4), located on chromosome 18q21.1, that encodes a critical cytoplasmic mediator in the transforming growth factor-beta signaling pathway. The mutant SMAD4 proteins are predicted to be truncated at the carboxyl-terminus and lack sequences required for normal function. These results confirm an important role for SMAD4 in the development of gastrointestinal tumors.     

Determination of the diffusion coefficients of CuSO4, ZnSO4, and NiSO4 in aqueous solution

The diffusion coefficients of CuSO₄, ZnSO₄, and NiSO₄ in the aqueous solution systems of MSO₄ and MSO₄-H₂SO₄ were measured at 298 K using a diaphragm-cell method, and are listed as a function of molar concentrations of MSO₄ and H₂SO₄. It was found that the concentration dependencies of the diffusion coefficients for CuSO₄, ZnSO₄, and NiSO₄ in each single metal sulfate solution are very similar. The presence of H₂SO₄ generally causes a less significant concentration dependency of the diffusion coefficients of MSO₄. The concentration dependencies of the diffusion coefficients of CuSO₄ in aqueous solutions of CuSO₄ and CuSO₄-H₂SO₄ are attributed to the changes in the mean activity coefficient of CuSO₄ and the viscosity of the solutions. formerly Graduate Student, Department of Metallurgy, Kyoto University, Kyoto, Japan     

结晶法分离MnSO4和MgSO4的若干问题讨论

绘制了ＭｎＳＯ４—ＭｇＳＯ４—Ｈ２Ｏ体系相图并以此讨论了结晶法分离ＭｎＳＯ４和ＭｇＳＯ４工艺，结果表明以现有的工艺来分离ＭｎＳＯ４和ＭｇＳＯ４是不可行的     

Reactions in the systems MoSi3N4 and NiSi3N4

The reaction products, formed during annealing of porous powder mixtures of Si₃N₄ with non-nitride forming metals like Ni or Mo, will depend on the partial pressure of N₂ in the atmosphere. In a diffusion couple, however, nitrogen has to be released at the Si₃N₄-interface during the formation of a metal silicide. It cannot escape easily and builds up a higher pressure of nitrogen at this interface. Therefore, the reaction products are different from those in porous pellets. This has been verified for NiSi₃N₄ and MoSi₃N₄ couples. The role of traces of oxygen on these reactions will be discussed.     

Moving GLUT4: the biogenesis and trafficking of GLUT4 storage vesicles

The GLUT4 system in muscle and fat cells plays an important role in whole-body glucose homeostasis. Insulin stimulates the translocation of GLUT4 from an intracellular storage compartment to the cell surface. The nature of this compartment remains largely unknown. We review recent studies describing the biogenesis and molecular constituents of the GLUT4 storage compartment and conclude that it is segregated from the endosomal and biosynthetic pathways. Further, we present evidence to suggest that the GLUT4 storage compartment moves directly to the plasma membrane in response to insulin and, hence, is analogous to small synaptic vesicles in neurons. We propose that the GLUT4 storage compartment be referred to as GLUT4 storage vesicles or GSVs.     

IL-12 induces growth of the IL-4-dependent CT4S line and has a synergistic effect on IL-4-induced CT4S proliferation

In the course of studies designed to explore the effect of interleukin 12 (IL-12) on the development of experimental autoimmune uveoretinitis (EAU), we observed that supernatants from IL-12-treated cultures of ocular antigen-specific lymphocytes induced proliferation of the interleukin 4 (IL-4)-dependent CT4S line. This result was surprising, as these supernatants were not expected to contain high levels of IL-4. We therefore explored the possibility that IL-12 itself, that remained in the supernatants, could induce proliferation of CT4S cells. In this series of experiments we demonstrate that CT4S cells proliferate to recombinant as well as to naturally produced IL-12, and that IL-4 and IL-12 synergize in supporting proliferation of CT4S cells. The proliferation induced by IL-12, as well as the synergistic effect with IL-4, can be reversed by neutralizing anti-IL-12 antibodies. Proliferation of CT4S can be abrogated completely by a combination of antibodies against IL-4 and IL-12. Our data have important implications for the use of CT4S as a specific bioassay for IL-4, since both IL-4 and IL-12 may be found together in at least some culture supernatants. Furthermore, our results suggest that the CT4S line (or a derivative selected from it) could be used as a bioassay for detection of IL-12 in combination with the specific antibodies.     

Water and solute activities in the aqueous H2SO4 -(NH4)2SO4 solutions

The activities of water in H₂SO₄-(NH₄)₂SO₄-H₂O solutions, the concentrations of which ranged from 0.1 to 4.0 mol kg_-1 H₂SO₄ and 0.1 to 5.0 mol kg_-1 (NH₄)₂SO₄, were determined by an isopiestic method at 298 K. The experimentally determined water activities showed considerable deviation from the Zdanovskii rule. The activities of water were not in agreement with those calculated from the Robinson-Bower equation, even though the formation of sulfato-complexes of NH₄(I) and the dissociation of sulfuric acid were taken into consideration. The behavior of H₂SO₄-(NH4)₂SO₄ solu-tions is quite different from other systems. Water activities of aqueous solutions of H₂SO₄-Li₂SO₄ and H₂SO₄-Na₂SO₄ can be calculated from the Robinson-Bower equation with satisfactory accuracy. The interesting behavior of (NH₄)₂SO₄ can be attributed to the water structure-breaking property of NH₄ ⁺ ions. An additivity equation for estimating the water activity of aqueous H₂SO₄ solutions con-taining (NH₄)₂SO₄ was proposed by considering the contributing effects of solutes on the structure of water. The proposed equation satisfactorily described the solution system under investigation. The mean activity coefficients of H₂SO₄ and (NH₄)₂SO₄ in the solution system, H₂SO₄-(NH₄)₂SO₄-H₂O, at 298 K, were calculated by the McKay-Perring method using the water activities experimentally determined. It is believed that the calculated values for concentrated solutions of more than one sol-ute are sufficiently accurate since the mean activity coefficients of H₂SO₄ agree with the values measured by the emf method.