Physicochemical,adsorption, and catalytic properties of high-silica zeolites of the MFI type in the conversion of the propane–butane fraction into aromatic hydrocarbons

The complex of physicochemical properties of high-silica zeolites of the MFI-type obtained using organic templates, including hexamethylenediamine, POD-oils, and pentaerythritol, has been investigated. It was shown that zeolites produced using different templates demonstrated different activity and selectivity in the process of converting the propane–butane fraction into aromatic hydrocarbons.     

Comparison of the structural properties of compounds containing the XSSX moiety (X = H,Me, R,Cl, Br,F, OR)

A comparison of the structural parameters of a wide variety of compounds containing the S–S bond is summarized.     

The impact of the discovery of the polymerization of the α-olefins on the development of the stereospecific polymerization of vinyl monomers

After a short survey of the first indications on the existence of stereoregularity in the main chains of the vinyl polymers, the first syntheses of stereoregular poly(vinylethers) and polystyrene are briefly summarized. The difficulties encountered in the early investigations of the propylene polymerization by the CoO/MoO₃/Al₂O₃ and CrO₃/SiO₂/Al₂O₃ catalysts are considered and the isolation and identification of a crystalline component in the mixture of diastereomeric macromolecules thus obtained, are discussed. The results obtained by different research groups, independently investigating the stereospecific polymerization of vinyl monomers, are compared and finally an attempt is made to explore the origin of the very rapid progress made in this field by Natta and coworkers in connection with their discovery of the stereospecific polymerization of α-olefins with the ‘Ziegler-Natta catalysts’.     

A Polymorphism at the 3′-UTR Region of the Aromatase Gene Is Associated with the Efficacy of the Aromatase Inhibitor,Anastrozole, in Metastatic Breast Carcinoma

Estrogen-related genes and the fat mass and obesity-associated (FTO) gene play a critical role in estrogen metabolism, and those polymorphisms are associated with a poor prognosis in breast cancer. However, little is known about the association between these polymorphisms and the efficacy of anastrozole. The aim was to investigate the impact of the genetic polymorphisms, CYP19A1, 17-β-HSD-1 and FTO, on the response to anastrozole in metastatic breast carcinoma (MBC) and to evaluate the impact of those polymorphisms on various clinicopathologic features. Two-hundred seventy-two women with hormone receptor-positive MBC treated with anastrozole were identified retrospectively. DNA was extracted from peripheral blood and genotyped for five variants in three candidate genes. Time to progression was improved in patients carrying the variant alleles of rs4646 when compared to patients with the wild-type allele (16.40 months versus 13.52 months; p = 0.049). The rs4646 variant alleles were significantly associated with longer overall survival (37.3 months versus 31.6 months; p = 0.007). This relationship was not observed with the rs10046, rs2830, rs9926298 and rs9939609 polymorphisms. The findings of this study indicate that rs4646 polymorphism in the CYP19A1 gene may serve as a prognostic maker of the response to anastrozole in patients with MBC who are treated with anastrozole.     

Uncertainty Budget of the SMPS–APS System in the Measurement of PM1, PM2.5, and PM10

The effects of particulate matter on environment and public health have been widely studied in recent years. In spite of the presence of numerous studies about this topic there is no agreement on the relative importance of the particles' size and origin with respect to health effects among researchers. Nevertheless, air quality standards are moving, as the epidemiological attention, towards greater focus on the smaller particles. The most reliable method used in measuring particulate matter (PM) is the gravimetric method since it directly measures PM concentration, guaranteeing an effective traceability to international standards. This technique, however, neglects the possibility to correlate short term intraday atmospheric parameter variations that can influence ambient particle concentration and size distribution as well as human activity patterns. Besides, a continuous method to determine PM concentrations through the measurement of the number size distribution is the system constituted by a Scanning Mobility Particle Sizer (SMPS) and an Aerodynamic Particle Sizer (APS). In this article, the evaluation of the uncertainty budget in measuring PM through the SMPS–APS system, as well as a metrological comparison with the gravimetric reference method in order to analyze the compatibility, was carried out and applied with reference to an experimental campaign developed in a rural site. This choice allowed to assume the hypothesis of spherical particle morphology. The average PM₁₀, PM_2.5, and PM₁ uncertainties obtained for the SMPS–APS system are equal to 27%, 29%, and 31%, respectively. Here the principle influence parameter is the particle density that has to be directly measured with low uncertainty in order to reduce the PM uncertainty.     

Report of the color committee, 1953–1954

It may be concluded from the work of the committee during the past year that

1. eight of 18 instruments used in reporting requested data do not meet A.O.C.S. specifications. This conclusion is not necessarily a criticism of the instruments since only two of the instruments gave results materially out of line;
2. the use of standardizing solutions holds promise;
3. the possibility of using readings at only one or two appropriate wave-lengths suggests itself as a practical method of oil grading;
4. additional committee work is necessary not only in the direction so far taken but in other directions which may hold promise of giving precise instrumental color values.