Native valve infective endocarditis in elderly and younger adult patients: comparison of clinical features and outcomes with use of the Duke criteria and the Duke Endocarditis Database

The effect of age on the presentation and outcome of infective endocarditis (IE) is unclear. Many of the available data are based on analyses of mixed populations of patients including intravenous drug users or those with prosthetic valve endocarditis or native valve IE. We used the Duke criteria to compare the characteristics of 44 episodes of definite native valve IE in elderly patients (> 64 years old) with the characteristics of 64 similarly defined episodes of native valve IE in younger, nonintravenous-drug-using adult patients (> 29 years and < 60 years old). Our data suggest that the clinical presentation, characteristics, and outcome of native valve IE are similar for elderly patients and younger adult patients, although elderly patients were hospitalized an average of 12 days longer. Although we found that the occurrence of renal failure and cerebral embolism during an episode of IE was associated with higher rates of death (odds ratios, 4.8 and 4.0, respectively), age was not a significant contributor to mortality.     

Seminar planning guidelines. As I see it

Small local chapter groups can present quality cost effective regional seminars. Key components are dedication of members, teamwork, and a sense of direction. The following guidelines and information can provide a framework for planning and coordinating a seminar.     

Phytate Removal from soybean proteins

The ability of Ca++, Ba++ and Zn++ ions to complex with and precipitate phytate ions was investigated as a possible approach for producing phytate-reduced soy-protein isolates. The treatments involved adding divalent cation reagents to mildly alkaline soyprotein extracts, or using mildly alkaline solutions of the cation reagent as protein extractant. Treatments used up to 5% (w/v) divalent cation reagent in dilute NaOH at pH 8–9 at room temperature with stirring for 1 hr. The proteins that remained soluble, or that were extracted following the above treatments, were further fractionated by dialysis against distilled water and then adjusted to the isoelectric pH of 4.5 with HCl. All treatments generally precipitated 15–90% of the total extracted proteins. The resulting phytate-reduced fractions had their total P reduced by ca. 30–74%, but their yields were reduced to only 11–85% of the total extract proteins. On the basis of these findings and on other adverse factors, e.g., toxicity, possible off-flavor and reduced functionality from residual precipitant ions, the divalent cation-fractionation method is not recommended for producing phytate-reduced soy-protein isolates for food use.     

Evaluation of four steering wheels to determine driver hand placement in a static environment

While much research exists on occupant packaging both proprietary and in the literature, more detailed research regarding user preferences for subjective ratings of steering wheel designs is sparse in published literature. This study aimed to explore the driver interactions with production steering wheels in four vehicles by using anthropometric data, driver hand placement, and driver grip design preferences for Generation-Y and Baby Boomers. In this study, participants selected their preferred grip diameter, responded to a series of questions about the steering wheel grip as they sat in four vehicles, and rank ordered their preferred grip design. Thirty-two male participants (16 Baby Boomers between ages 47 and 65 and 16 Generation-Y between ages 18 and 29) participated in the study. Drivers demonstrated different gripping behavior between vehicles and between groups. Recommendations for future work in steering wheel grip design and naturalistic driver hand positioning are discussed.     

Characterization of branched chain fatty acids from subcutaneous triacyglycerols of barley-fed lambs

The fatty acids of subcutaneous triacylglycerols (containing ca. 11% of branched chain components) from lambs fed on barley-rich diets were fractionated by treatment with mercuric acetate and by urea adduct formation to yield concentrates rich in the branched chain components, all of which were saturated. The concentrates were subjected to analysis by high resolution gas liquid chromatography in conjunction with mass spectrometry. The branched chain fatty acids consisted of a complex mixture of mono-, di-, and trimethyl substituted components. The greater part of the mixture comprised monomethyl substituted acids of chain length 10–17 carbon atoms. Within each of these molecular species, a number of positional isomers was identified, notably in respect of methyltetradecanoic acid (methyl substituent on carbon 2, 4, 6, 8, 10, and 12) and methylhexadecanoic acid (methyl substituent on carbon 2, 4, 6, 8, 12, and 14). Homologous series also could be recognized of one of which all eight members from 4-methyldecanoic acid to 4-methylheptadecanoic acid were identified; together they accounted for ca. 39% of the branched chain fatty acids which were sampled for mass spectrometry. The dibranched acids identified consisted of five members of a homologous series, ranging in chain length from 11–15 carbon atoms and with substituent methyl groups at positions 4 and 8. Though the identity of only one tribranched acid (2,6,10-trimethyltetradecanoic acid) was established, others also apparently were present in the mixture. The probable involvement of methylmalonate in the biosynthesis of these branched chain acids is discussed briefly, with particular reference to the availability of vitamin B₁₂ in relation to the activity of methylmalonyl coenzyme A mutase.     

Attrition mill operating characteristics

The attrition mill is a device for mechanically reducing solid particle size by intense agitation of a slurry of material being milled and coarse milling media. For example, in 10 hours of milling, specific surfaces of 40 and 25 m²/g were obtained for alumina and barite, corresponding to 38 and 56 nm equivalent spherical diameter, respectively. Size reduction rates for relatively coarse particles were first-order and increased linearly with power input to the mill. Optimum milling medium concentration corresponded to medium particles moving a distance of approximately 0.7 of their diameter before collision with another such particle. Power characteristics of the attrition mill were essentially the same as those of a radial flow turbine mixer. Laminar flow became disrupted at N_Re ≈ 200, while turbulent flow was established at N_Re > 8000. Slurries of fine powders exhibited the same linear power-average density dependence as single-phase liquids. However, a different dependence was observed with large particles.     

Electrosynthesis in systems of two immiscible liquids and a phase transfer catalyst. V. The anodic chlorination of naphthalene

The anodic chlorination of naphthalene in a water/methylene chloride emulsion and using tetrabutylammonium ion as the phase transfer catalyst is demonstrated; in conditions where the aqueous phase is saturated NaCl, the organic yield of 1-chloronaphthalene is 56% and the current yield is 33% after the passage of 2.33 F mol^–1 of naphthalene. It is shown, however, that when the aqueous phase also contains zinc chloride so that the species transferred is [(C₄H₉)₄N⁺]₂ZnCl ₄ ^–– , the yields can be increased to 92% and 49% respectively. The mechanism of these chlorinations is discussed.     

Characterization of polyester/polycarbonate blends by size exclusion chromatography and melt rheometry

A major obstacle to the study of polymer blends has been the lack of a convenient technique for measurement of molecular weight. Melt rheometry, while giving useful information related to processing and end-use performance, is incapable of providing detailed information on the individual components. This work describes the use of size exclusion chromatography (SEC) to study the molecular-weight distributions of polycarbonates and aromatic polyesters in blends of the two. SEC of the polycarbonate is achieved in a solvent which dissolves the polycarbonate, but not the polyester, while SEC is performed in a solvent which dissolves both components, but using selective detection. Thus, SEC is used to examine the individual components of the blend, while rheometry can be used to study the blend as a whole. This combination of techniques has been successfully used to analyze the effect of moisture, processing conditions, and recycling on blend properties.