Field-induced spin density waves in Bechgaard salts in the presence of normal impurities

We study theoretically the effect of the quasiparticle scattering in field-induced spin density waves (FISDW) in Bechgaard salts in a high magnetic field. The effects of scattering are introduced by a random impurity model similar to the one used by Zittartz in his analysis of the charge density wave. Within the single-gap approximation and weak impurity scattering, we find that the FISDW with normal impurities is similar to a superconductor with magnetic impurities. From this analogy the thermodynamics as well as the electronic thermal conductivity and the sound attenuation coefficient of the FISDW are obtained.On leave of absence from Nankai University, China.     

Bryostatin 1 induces ubiquitin COOH-terminal hydrolase in acute lymphoblastic leukemia cells

It has been previously reported that Bryostatin 1 (Bryo1) induces differentiation of the human acute lymphoblastic leukemia (ALL) cell line, Reh, to a monocytoid B-cell stage. In this study we demonstrate that a novel protein, ubiquitin COOH-terminal hydrolase (UCH-L1), is associated with this differentiation. Reh cells were treated with 200 nmol/l of Bryo1 for 72 h and analyzed for changes in morphology, surface immunophenotype, acid phosphatase and terminal deoxynucleotidyl transferase. Protein patterns of the parent and differentiated cells, by two-dimensional polyacrylamide gel electrophoresis (2D PAGE), were studied. Bryo1-treated cells expressed morphologic, phenotypic and enzymatic features of the monocytoid B-cell stage. The UCH-L1 enzyme (MW-pl 34-5.3) was detected by 2 D PAGE in the differentiated, but not in parent cells. The presence of UCH-L1 in the Bryo1-treated cells was further confirmed by immunoblotting of 2 D PAGE using UCH-L1 polyclonal antibody. Ubiquitin expression was studied in parent and Bryo1-treated cells and was compared with 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated cells. Both agents, TPA and Bryo1, increased the level of ubiquitin expression as detected by flow cytometry. Sodium borohydride, an inhibitor of UCH-L1, inhibited the Bryo1-induced differentiating effect on Reh cells. To date, the mechanism by which Bryo1, exerts its B-cell differentiating effect is not fully understood. This study shows that UCH-L1 expression may play a major role in Bryo1-induced differentiation in pre-B-ALL.     

Frequency measurements of 9- and 10-μm N2O lasertransitions

We have measured frequencies of N₂O transitions by heterodyning sub-Doppler fluorescence-stabilized N₂O laser radiation with that from a reference CO₂ laser. A high-resolution cavity incorporates a ribbed tube and a highly reflective grating, permitting the CW oscillation of both the 10⁰ 0-02⁰0 9-μm and the 10⁰0-00⁰1 10-μm regular bands. This is the first sub-Doppler frequency measurement of the 9-μm band. The accuracy in the determination of the rotational constants for both bands has been improved by an order of magnitude, and calculated transition frequencies are presented     

New CO2 laser lines in the 11-μm wavelength region:new hot bands

Nineteen new laser lines in the 11-μm wavelength region have been observed in CW oscillation from a CO₂ laser with a high-Q, high-resolution cavity at a higher than usual current density. The frequency of each line has been measured using heterodyne frequency measurement techniques. Analysis of the frequencies shows that 15 lines are rotation-vibration transitions of the 01¹2-[11¹1,03¹1]_I band (the first sequence hot band) of the CO₂ molecule and four lines belong to the rotation-vibration transitions of the 02²1-[12 ²0, 04²0]_I band of CO₂     

One-Step Generation of Multiple Gene-Edited Pigs by Electroporation of the CRISPR/Cas9 System into Zygotes to Reduce Xenoantigen Biosynthesis

Xenoantigens cause hyperacute rejection and limit the success of interspecific xenografts. Therefore, genes involved in xenoantigen biosynthesis, such as GGTA1, CMAH, and B4GALNT2, are key targets to improve the outcomes of xenotransplantation. In this study, we introduced a CRISPR/Cas9 system simultaneously targeting GGTA1, CMAH, and B4GALNT2 into in vitro-fertilized zygotes using electroporation for the one-step generation of multiple gene-edited pigs without xenoantigens. First, we optimized the combination of guide RNAs (gRNAs) targeting GGTA1 and CMAH with respect to gene editing efficiency in zygotes, and transferred electroporated embryos with the optimized gRNAs and Cas9 into recipient gilts. Next, we optimized the Cas9 protein concentration with respect to the gene editing efficiency when GGTA1, CMAH, and B4GALNT2 were targeted simultaneously, and generated gene-edited pigs using the optimized conditions. We achieved the one-step generation of GGTA1/CMAH double-edited pigs and GGTA1/CMAH/B4GALNT2 triple-edited pigs. Immunohistological analyses demonstrated the downregulation of xenoantigens; however, these multiple gene-edited pigs were genetic mosaics that failed to knock out some xenoantigens. Although mosaicism should be resolved, the electroporation technique could become a primary method for the one-step generation of multiple gene modifications in pigs aimed at improving pig-to-human xenotransplantation.     

Microscopic study on the polymorphism of Ca3SiO5

The polymorphism of Ca₃SiO₅ has been studied microscopically by following changes in optic properties and modes of twinning of the crystal as a function of temperature. Besides the six modifications already established, a hitherto-unidentified monoclinic phase M₃, which can be characterized only by microscopy at present, has been found to exist just below the rhombohedral phase (R). The transitions $\text{T}{}_2\text{?}\text{T}{}_3\text{et}\text{M}{}_1\text{?}\text{M}{}_2$ that give clear thermal effects on the DTA curve show no corresponding change under the microscope.     

Redistribution of impurity during recrystallization of alite in portland cement clinker

The redistribution of impurity in alite during recrystallization has been confirmed by means of the electron probe microanalysis. Each of the main impurity components shows a significant decrease in content during recrystallization. This demonstrates that the growth velocity of alite exerts influence on the amount of the impurity taken up in alite in solid solution from the interstitial melt. Whether M₃ or M₁ occurs at ambient temperature depends on the cooling rate of clinker as well as the chemical composition of alite.     

Two-stage pyrolysis of heavy oils. 3. Pyrolysis of tar-sand bitumens. Relation between ethylene yield and structural characteristics of heavy oils

Thermal cracking of tar-sand bitumens has been carried out using a two-stage pyrolysis reactor with temperature zones of 440°C and 750–800°C, respectively. Feedstocks were pyrolysed in the first stage into cracked oils, which were carried to the second stage for subsequent pyrolysis. Only 12–14 wt% of ethylene was obtained from tar-sand bitumens at the residence time of 1.2 s in the second stage, although 27 and 16 wt% were obtained from Taching and Iranian heavy vacuum residues, respectively. The tar-sand bitumens contain shorter paraffinic straight-chains and have more branched molecules than the vacuum residues of petroleum. A straight-chain paraffin index is proposed, with which a good correlation was obtained between ethylene yield and the fraction of straight-chain paraffin carbons in the heavy oil.     

Effect of polymer density on polyethylene hollow fiber membrane formation via thermally induced phase separation

Microporous high‐density polyethylene (HDPE) and low‐density polyethylene (LDPE) hollow fiber membranes were prepared from polyethylene–diisodecyl phthalate solution via thermally induced phase separation. Effect of the polyethylene density on the membrane structure and performance was investigated. The HDPE membrane showed about five times higher water permeability than the LDPE membrane because it had the larger pore and the higher porosity at the outer membrane surface. The formation of the larger pore was owing to both the initial larger structure formed by spinodal decomposition and the suppression of the diluent evaporation from the outer membrane surface due to the higher solution viscosity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 471–474, 2004