Screening and characterization of microorganisms with glutaryl-7ADCA acylase activity

A screening of microorganisms producing glutaryl-7ADCA acylase, an enzyme able to hydrolyse glutaric acid selectively from glutaryl-3-deacetoxy-7-aminocephalosporanic acid (glutaryl-7ADCA), has been carried out in soil samples. Five microorganisms expressing acylase activity were isolated and classified as Bacillus cereus, Achromobacter xylosooxidans, Bacillus sp., Pseudomonas sp. and Pseudomonas paucimobilis. The screening was carried out by preparing enrichment cultures containing glutaryl-7-ADCA or cephalosporin C as the selective carbon source. Four model compounds (adipoyl-, glutamyl- and glutaryl-p-nitroanilide and glutarylcoumarin), mimicking the glutaryl-7ADCA beta-lactam moiety, were synthesized as substrates suitable for the rapid screening of the microorganisms (2500) isolated from the enrichment cultures. A total of 300 strains were active on the model substrates and only 5 displayed acylase activity on glutaryl-7ADCA. The fermentation parameters, such as pH and inducer concentration, for the optimal acylase expression and acylase specificity towards the model substrates were different for each strain.     

Possibility of Using a High-Pressure Pneumatic Pump in the Porcelain Industry

The advantages and disadvantages of using a high-pressure pneumatic pump at porcelain and insulator works are discussed. The testing results of a prototype pump are described.     

Comparison between the Diffusion and Relaxation Models of Longitudinal Dispersion

The properties of the relaxation (wave) model of longitudinal dispersion are considered. The diffusion and relaxation models of longitudinal dispersion are compared. It is shown that, depending on its coefficients, the relaxation model can be assigned to two main classes and one intermediate class provided the boundary conditions for the model equations are correctly formulated. New equations are obtained, whose solutions are asymptotically close to the solutions of the diffusion model.     

Piezoelectric fiber optic phase modulator with a reduced level of spurious polarization modulation

It is experimentally demonstrated that a tenfold decrease in the level of spurious polarization modulation can be achieved in a fiber optic phase modulator comprising two fiber sections featuring the polarization mode conversion, arranged on the same piezoelement.     

A quantum full adder for a scalable nuclear spin quantum computer

We demonstrate a strategy for implementation a quantum full adder in a spin chain quantum computer. As an example, we simulate a quantum full adder in a chain containing 201 spins. Our simulations also demonstrate how one can minimize errors generated by non-resonant effects.     

Ophthalmologic findings in Usher syndrome type 2A

Thirty-seven patients, comprising 24 familial cases and 13 isolated patients with Usher syndrome type II (USH2), underwent ophthalmologic examination. Based on the degree of hearing loss, normal vestibular function, and gene-linkage analysis, familial cases were assumed to have USH2A. An analysis of genetic heterogeneity failed to reveal the presence of a second locus in the Dutch population. Although the patients appear to belong to a genetically homogeneous group, remarkable ophthalmologic variability was found. Corrected visual acuity decreased with age and remarkable differences in visual acuity were found within one family. Fundoscopic findings were classified as type A if attenuated vessels and bone corpuscles in all quadrants were found or as type B if findings other than these were found. The prevalence of type A significantly increased with age.     

Use of Shears with a “Rolling Cut”

This article examines the advantages and disadvantages of using guillotine shears with an inclined top blade for the cross-cutting of flat-rolled products on modern plate mills. It is shown that it is necessary to use shears of an improved design. After shears with a “rolling cut,” designed by the All-Russia Scientific Research, Planning, and Design Institute of Metallurgical Machinery (VNIImetmash), were installed in the line of the 2800 plate mill at the Ural Steel combine, the institute conducted studies to optimize the parameters of the cutting operation and developed recommendations for the shears operators on how to adjust the shears to obtain a quality cut edge on the plates.