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The reactivity and stability of the edge faces of swelling clay minerals can be altered by layer charge and the stacking structure; however, these effects are poorly understood due to experimental limitations. The structure and stability of the montmorillonite {110}, {010}, {100}, and {130} edge faces with a layer charge of either y= 0.50 or y= 0.33 (e−/Si4O10) were investigated using first-principles calculations based on density functional theory. Stacked- and single-layer models were tested and compared to understand the effect of stacking on the stability of montmorillonite edge faces. Most stacked layers stabilize the edge faces by creating hydrogen bonds between the layers; therefore, the surface energy of the layers in the stacked-layer model is lower than in the single-layer model. This indicates that the estimates of edge face surface energy should consider the swelling conditions. Negative surface energies were calculated for these edge faces in the presence of chemisorbed water molecules. A high layer charge of 0.50 reduced the surface energy relative to that of the low layer charge of 0.33. The isomorphic substitution of Mg for Al increased the stability of interlayer Na ion positions, which were stable in the trigonal ring next to the Mg ions. The lowest surface energies of the {010} and {130} edge faces were characterized by the presence of Mg ions on edge faces, which had a strong cation adsorption site due to the local negative charge of the edges. The coordination numbers of O atoms around cations adsorbed to these edge faces were small in comparison to interlayers without water.

Electromagnetic wave techniques have been used extensively for materials characterization. For techniques that use propagating waves, there are actually three modes for electromagnetic wave transmission from the source to the receiver: direct waves, reflected waves and lateral waves (also known as surface waves). An interesting characteristic of lateral waves is that they propagate along the boundary between two different materials with the interaction being confined to the boundary region. In this work, the use of lateral waves for remote and non-contacting sensing is considered with an emphasis on characterization of metallic surfaces. The interaction of these waves with near-surface micro-structural features such as cracks or voids is considered showing that lateral waves can be used to detect these features using microwave-based techniques. While the lateral field strength is small compared to other modes, it is shown that this field is sufficiently large to be useful for crack detection purposes. Experiments on stainless steel plates with slit type defects show model system results for the detection of surface breaking defects using this lateral wave method.

Quantum yields can be determined by global fitting of prolonged change of concentration against absorbed photon numbers. Quantum yields of synthesized amphiphilic diarylethene in solution and in suspension were analyzed by the global fitting upon irradiation with UV (365 nm) light. Quantum yields of cyclization and cycloreversion reaction in acetonitrile were obtained as 0.59 and 0.013, respectively using the absolute method. In suspension, quantum yield of cyclization was determined as 0.76 using the relative method. The result indicates that the preferred conformation of the open-ring isomer in the aggregate was antiparallel due to the hydrophilic chains and hydrogen bond.Quantum yields of the synthesized amphiphilic diarylethene in solution and in suspension were obtained by global fitting. The result indicates that the preferred conformation of the open-ring isomer in the aggregate was antiparallel due to the hydrophilic chains and hydrogen bonding.

It is important to understand the coupled processes of sorption and diffusion of radionuclides (RNs) in compacted bentonite, and to develop mechanistic models that can aid in the prediction of the long-term performance of geological disposal systems of radioactive waste. The integrated sorption and diffusion (ISD) model was developed based on the consistent combination of clay–water interaction, sorption and diffusion models. The diffusion model based on the electrical double layer theory describing relative ionic concentrations and viscoelectric effects at the negatively charged clay surface was coupled with porewater chemistry and sorption models. This ISD model was successfully tested for various actinides with a complex chemistry (Np(V), Am(III), U(VI) under conditions where variably charged carbonate complexes are formed) considered in Part 1, by using published diffusion and sorption data (Da, De, Kd) as a function of partial montmorillonite density. Quantitative agreements were observed by considering uncertainty in porewater chemistry and dominant aqueous species. It can therefore be concluded that the ISD model developed here is able to adequately explain the sorption and diffusion behavior of various RNs with a complex chemistry in compacted bentonites. The performed modeling indicates that uncertainties are mainly related to porewater chemistry and RN speciation and that these parameters need to be carefully evaluated.

AbstractDiffusion and sorption of radionuclides in compacted bentonite/montmorillonite are key processes in the safe geological disposal of radioactive waste. In this study, the effects of carbonate and salinity on neptunium(V) diffusion and sorption in compacted sodium montmorillonite were investigated by experimental and modeling approaches. Effective diffusion coefficients (De) and distribution coefficients (Kd) of 237Np(V) in sodium montmorillonite compacted to a dry density of 800 kg m−3were measured under four chemical conditions with different salinities (0.05/0.5 M NaCl) and carbonate concentrations (0/0.01 M NaHCO3). Devalues for carbonate-free conditions were of the order of 10−10–10−11m2s−1and decreased as salinity increased, and those for carbonate conditions were of the order of 10−11–10−12m2s−1and showed the opposite dependence. Diffusion-derived Kdvalues for carbonate-free conditions were higher by one order of magnitude than those for carbonate conditions. Diffusion and sorption behaviors were interpreted based on mechanistic models by coupling thermodynamic aqueous speciation, thermodynamic sorption model (TSM) based on ion exchange, and surface complexation reactions, and a diffusion model based on electrical double layer (EDL) theory in homogeneous narrow pores. The model predicted the experimentally observed tendency of Deand Kdqualitatively, as a result of the following mechanisms; 1) the dominant aqueous species are NpO2+and NpO2CO3−for carbonate-free and carbonate conditions, respectively, 2) the effects of cation excess and anion exclusion result in opposite tendencies of Defor salinity, 3) higher carbonate in solution inhibits sorption due to the formation of carbonate complexes.

Using an intestinal methicillin-resistant Staphylococcusaureus (MRSA)-carrying rat model, we compared the influence of piperacillin (PIPC) on the intestinal flora to those of cefazolin (CEZ), cefmetazole (CMZ), and flomoxef (FMOX). The number of MRSA did not increase after PIPC and CEZ administrations compared with the nontreated group. However, it significantly increased in the cases of FMOX and CMZ administration (P < 0.01). In the FMOX- and CMZ-treated groups, the intestinal flora was severely disrupted and the recovery of the number of Escherichia coli and Bacteroides spp. cells was delayed. On the other hand, in the PIPC- and CEZ-treated groups, the rapid recovery of bacteria that composed the intestinal flora was observed. The Cmax/MIC50 and Ctrough/MIC50 ratios in E. coli and Bacteroides spp. in the case of FMOX and CMZ were relatively higher than those in the case of the PIPC- and CEZ-treated groups.

The induction of beta-lactamase in Enterobacter cloacae GN5797 was studied by using 23 beta-lactam antiobiotics, including newly introduced drugs, as inducers. the beta-lactam antibiotics can be classified into three groups on the basis of their inducer activity. Among the tested cephalosporins, cephamycin derivatives such as cefoxitin, cefmetazole, and YM09330 had high inducer activity even at low drug concentrations. On the other hand, cefoperazone, cefsulodin, piperacillin, and apalcillin showed low inducer activity when compared with the other cephalosporins.

The susceptibilities of 52 clinical isolates of Bacteroides fragilis to five monoanionic cephalosporins were examined. Cefoperazone showed the highest antibacterial activity, followed by ceftezole, cefazolin, cefamandole, and cephalothin. There were two groups of resistant strains: one group (ca. 15%), of which B. fragilis G-232 was a typical sample, was resistant to ceftezole (MIC, 100 micrograms/ml), cefazolin (MIC, 100 micrograms/ml), and cephalothin (MIC, 200 micrograms/ml) but not cefoperazone (MIC, 6.25 micrograms/ml) or cefamandole (MIC, 25 micrograms/ml). On the basis of studies of stability to beta-lactamase, outer membrane permeation, and affinity for penicillin-binding proteins (PBPs), we conclude that decreased affinity for PBP 3 may play an important role in the resistance to ceftezole, cefazolin, and cephalothin in B. fragilis G-232. Another group (also ca. 15%), of which B. fragilis G-242 was a representative, was resistant to all five cephalosporins (MIC, 100 to 400 micrograms/ml) and produced a high amount of beta-lactamase. Similar broad-spectrum resistance was seen in a mutant of strain G-232 that had a greater-than-30-fold increase in beta-lactamase production.

The susceptibility of 53 clinical isolates of Bacteroides fragilis to cephamycins was examined. Judging from the MICs for 50% of the strains tested, moxalactam was the most active, however, judging from the MICs for 90% of the strains tested, cefbuperazone was more effective than moxalactam. A correlation was observed between in vitro activity of benzylpenicillin and cephaloridine and beta-lactamase production. Inactivation due to enzymatic hydrolysis of cephamycins over a short time was not observed; however, inactivation was detected by a double disk diffusion test, and moxalactam was most easily inactivated. We conclude that inactivation due to enzymatic hydrolysis of cephamycins over a long time may play an important role in resistance to some cephamycins in strains of B. fragilis.

Bacteroides fragilis strains were isolated from clinical specimens. B. fragilis G-237 was highly resistant to beta-lactam antibiotics due to beta-lactamase production. The purified enzyme from this strain gave a single protein band on polyacrylamide gel electrophoresis. The isoelectric point was 4.8, and the molecular weight was estimated to be 26,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme activity was inhibited by p-chloromercuribenzoate and iodine but not by clavulanic acid or sulbactam. The purified enzyme showed a unique substrate profile by hydrolyzing at a high rate most of the cephalosporins, including cephamycin derivatives, penicillins, and imipenem (formerly imipemide, N-formimidoyl thienamycin, or MK 0787).

The activities of T-1982 (sodium 7 beta-[(2R, 3S)-2-(4-ethyl-2, 3-dioxo-1-piperazine-carboxamido)-3-hydroxybutanamido]-7 alpha-methoxy-3-[(1-methyl-1H-tetrazol-5-yl)thiomethyl]-3-cephem-4-carboxylate) against various gram-positive and gram-negative bacteria were compare with those of cefmetazole, cefoxitin, cefazolin, and cefoperazone. T-1982 was active against both gram-positive and gram-negative bacteria, including genera resistant to the other cephalosporins. T-1982 exhibited greater activity than did cefmetazole, cefoxitin, cefazolin, or cefoperazone against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Serratia marcescens and was also highly active against Bacteroides fragilis. T-1982 was as stable to various beta-lactamases as were cefmetazole and cefoxitin. The therapeutic activities of T-1982 in mice experimentally infected with various gram-negative bacteria were superior to those of cefmetazole, cefoxitin, cefazolin, and cefoperazone.

Higher culture pH of 7.6 was shown to be preferable for the inclusion body formation of salmon growth hormone (SGH) inEscherichiacoliharboring a recombinant plasmid. High-level formation of SGH inclusion bodies was achieved at 33°C (pH 7.6). Growth inhibition by soluble SGH was also observed.

T-8581 is a new water-soluble triazole antifungal agent. The geometric mean IC80s (GM-IC80S; where the IC80 is the lowest drug concentration which reduced the optical density at 630 nm by 80% compared with the optical density at 630 nm of the drug-free control) for Candida albicans were as follows: T-8581, 0.218 microgram/ml; fluconazole; 0.148 microgram/ml; and itraconazole, 0.0170 microgram/ml. For Cryptococcus neoformans the GM-IC80s were as follows: T-8581, 9.28 micrograms/ml; fluconazole, 4.00 micrograms/ml; and itraconazole, 0.119 microgram/ml. For Aspergillus fumigatus the GM-IC80s were as follows: T-8581, 71.0 micrograms/ml; fluconazole, 239 micrograms/ml; and itraconazole, 0.379 microgram/ml. Against systemic candidiasis in mice, the 50% effective doses (ED50s) of T-8581, fluconazole, and itraconazole (given orally) were 0.412, 0.392, and > 320 mg/kg of body weight, respectively. Against systemic aspergillosis in mice, the ED50s of T-8581, fluconazole, and itraconazole (given orally) were 50.5, 138, > 320 mg/kg, respectively. T-8581 was also efficacious when it was given parenterally (ED50, 59.2 mg/kg), while the ED50 of fluconazole given parenterally was > 20 mg/kg. Against systemic aspergillosis in rabbits, T-8581 was more effective than fluconazole and itraconazole in prolonging the life span. The high concentrations of T-8581 were observed in the sera of mice, rats, rabbits and dogs. Species differences in half-lives and areas under the concentration-time curves were observed, with the values for mice, rats, rabbits, and dogs increasing in that order. These results suggest that T-8581 would be a potentially effective antifungal drug for oral and parenteral use.

We numerically investigate the fractal structure of two-dimensional quantum gravity coupled to matter central charge c for −2 < c < 1. We reformulate Q-state Potts model into the model which can be identified as a weighted percolation cluster model. The c-dependence of the fractal dimension based on the finite size scaling hypothesis is measured and has excellent agreement with our theoretical predictions previously evaluated analytically. [Copyright &y& Elsevier]

Monte-Carlo simulations of abelian projection in T≠ 0 pure lattice QCD show that 1) Polyakov loops written in terms of abelian link fields alone play a role of an order parameter of deconfinement transition, 2) the abelian Polyakov loops are decomposed into contributions from Dirac strings of monopoles and from photons, 3) vanishing of the abelian Polyakov loops in the confinement phase is due to the Dirac strings alone and the photons give a finite contribution in both phases. Moreover, these results appear to hold good in unitary gauges. This suggests that monopole condensation as the color confinement mechanism is gauge independent.

Abstract: Serratia marcescens W-313/pSW313 was isolated from a clinical specimen that showed resistance to various β-lactams. β-Lactamase from this strain hydrolyzed oxyiminocephalosporins and carbapenems, but did not hydrolyze 2-carboxypenam and aztreonam. The kinetic parameters of this enzyme were similar to those of the carbapenem-hydrolyzing β-lactamases mediated by R-plasmid from Pseudomonas aeruginosa and S. marcescens, whose properties were previously reported.

The purified cephalosporinase from Proteus vulgarishydrolyzed a variety of cephalosporins, including cefuroxime, at a high level; its activity was inhibited by clavulanic acid.

Outer membrane permeation of Bacteroides fragilis by cephalosporins was examined by a previously described method. The permeation parameters of cephalosporins in B. fragilis were close to 10(-5) cm3/min per microgram of cell dry weight. These values were about an order of magnitude lower than those in Escherichia coli. In B. fragilis, the permeation was not directly proportional to the hydrophilicity of cephalosporins, and the ion selectivity was weak.

The activity of cefoperazone against a strain with an inducible cephalosporinase and a mutant that produces the enzyme constitutively indicates that the low inducer activity of this antibiotic plays an important role in its activity against Enterobacter cloacae.

The signal amplitude and the phase of acoustically stimulated electromagnetic (ASEM) response have been investigated in steel. In the ASEM method, magnetization is temporally modulated with the radio frequency (rf) of irradiated ultrasonic waves through magnetomechanical coupling. The first-harmonic components of the induced rf dipolar magnetic fields are detected using a resonant loop antenna. The signal amplitude of ASEM waves is determined by the magnitude of local piezomagnetic coefficients on an acoustically excited spot. Here, we divided the ASEM waves into the "in-phase" and "quadrature" components by phase-sensitive detection (PSD). On the basis of the linear response theory, we provided the theoretical formalism of ASEM response by introducing local complex piezomagnetic coefficients, d loc = d' + id''. We investigated the magnetic field (H) dependence of the individual components on the different surface conditions of steel plates. The in-phase component [[?] d'(H)] shows a hysteresis loop on the machined surface of a steel plate, in which d'(H) switches sign at two finite field values, +-H 0. The inversion of magnetization associated with the applied static fields is thus definitely observed in the PSD measurements. In addition, we measured the hysteresis behaviors on a steel surface with a thin mill scale (iron oxide layers). The hysteresis loop broadens and a significant contribution of the quadrature component [[?] d''(H)] is found. We discuss the origin of the hysteresis behaviors of d' and d'' using the Debye relaxation model.

Steelmaking slag is by-product of the steelmaking process and has a high content of iron. In order to recover this iron, steelmaking slag is processed with various methods such as crushing, sieving and magnetic separating. Magnetic separators process steelmaking slag in multiple layers for mass production and non-magnetic particles are attracted to a magnet roll by magnetic particles [1]. Therefore, precision of separation is low with conventional pulley magnetic separator. This study proposes an efficient magnetic separating technology. In proposal magnetic separation, a fluctuating magnetic field is generated by rotation of a magnet roll with multiple poles. This quick change of the magnetic field generates strong agitation in the attracted particles and eliminates non-magnetic particles [2]. As the result of separation test with steelmaking slag, the iron content of magnetic side and the overall separation efficiency is higher in proposal method than in conventional method.

The stereoselective synthesis of 5‐fluoro‐2'‐deoxy‐β‐uridine (IVb) from the silylated pyrimidine (I) and the ribofuranosyl chloride (II) in the presence of p‐nitrophenol (III) and iron(III) chloride is optimized.

The quinolone carboxylic acids (VI) are synthesized and their antibacterial activity in mice is evaluated.

The 4‐pyridone‐3‐carboxylic acids (VII) are prepared by Wittig reaction, coupling of the olefins (III) with the acetal (IV) and the anilines (V), followed by cyclization.