Genetic mapping of the spinocerebellar ataxia type 2 gene on human chromosome 12

The dominant spinocerebellar ataxias are a genetically heterogeneous group of diseases leading to premature death of neurons in the cerebellum and other parts of the nervous system. The mutation causing SCA1 is on human chromosome (CHR) 6p and SCA3 is on CHR 14q. To refine the location of the SCA2 gene on CHR 12q, we performed genetic linkage analysis between the SCA2 locus and nine Ioci (D12S58, D12S78, D12S317, D12S330, D12S353, D12S84, D12S105, D12S79, and PLA2) in three SCA2 families. The highest pairwise lod scores were obtained between SCA2 and D12S84/D12S105 and D12S79. We determined the best order and genetic distances among these loci in ten multigenerational families by multipoint linkage analysis and established the following order: D12S101-D12S58/IGF1- D12S78-D12S317-D12S330/D12S353-D12S84/D 12S105-D12S79-PLA2. Using this genetic map, multipoint linkage analysis placed SCA2 between D12S84/D12S105 and D12S79.     

The effects of whey cations on the kinetic parameters of a model for the enzymic hydrolysis of lactose

The effects of whey cations (Ca²⁺, Mg²⁺) on the enzymic hydrolysis of lactose have been studied, at temperatures in the range 30–50°C, in a continuous stirred tank reactor (CSTR), using an immobilized β-galactosidase (Novozym 231). A model for the variation of V_max (the maximum rate in the Michaelis—Menten expression) in the presence of the ionic environment has been developed based on the Gouy electrical double layer concept and the liquid phase bimolecular process. In the presence of one cation (Mg²⁺), the mean value of the model parameter a_v, an approach distance including the hydration radius of the protein, was 27 × 10^?10 m, almost identical to the value obtained by the crystal density method. When two cations (Mg²⁺ and Ca²⁺) were present simultaneously the value of V_max as a function of the ionic strength showed a maximum which may be explained by the Stern adsorption modification of the Gouy theory.     

Effect of temperature on fermentation kinetics of waste sulphite liquor by Saccharomyces cerevisiae

The optimum operating temperatures for the maximum production of ethanol and the maximum utilization of substrate in batch fermentations of a waste sulphite liquor (WSL) as well as a synthetic medium using Saccharomyces cerevisiae were determined. The fastest consumption of substrate resulting in the shortest fermentation times of 13 h and 45 h was achieved at 35°C and 30°C for the synthetic medium and the WSL, respectively. The concentrations of ethanol in the two media were also maximum under these conditions: 11.6g dm^?3 and 9.4 g dm^?3 for the synthetic medium and the WSL, respectively. The productivities of biomass and ethanol increased with the increase of temperature and reached maximum values of 0.89 g dm^?3 h^?1 and 0.21 g dm^?3 h^?1 in the synthetic medium and the WSL, respectively. The inhibiting agents in the waste sulphite liquor affected the metabolic rates of microbial activities and prolonged the overall fermentation time while decreasing the productivities of biomass and ethanol. From analysis of the fermentation kinetics a mathematical model based on the Monod model was developed to describe the cellular growth and ethanol production. The model included inhibition terms for ethanol and the inhibiting agents in the waste liquor. The temperature dependence of the model parameters followed the Arrhenius law for temperatures between 15°C and 35°C. The activation energies (E) and the frequency constants (A) of these parameters were also determined.     

Kinetics of cupric oxide catalysed oxidation of propylene in a stirred reactor

The catalytic air oxidation of propylene to acrolein over a supported copper oxide catalyst was investigated in a continuous stirred vessel reactor between 375° and 450°C at atmospheric pressure. The effect of temperature, ratio of oxygen to propylene in feed and total feed rate (or contact time) on the conversion of propylene and the yield of acrolein were determined. It was found that with an increase in temperature, ratio of oxygen to propylene and contact time, the yield drops considerably though conversion increases. A study of the mixing characteristics of the stirred vessel reactor was carried out by following the conversion at various stirrer speeds. The kinetic data obtained were tested to determine the most probable model by the Hougen-Watson method. The model that satisfactorily correlated the data describes the rate-controlling step as the surface reaction occurring between adsorbed propylene, a vacant site and oxygen in the gas phase. The following Hougen-Watson type rate equation has been proposed The constants in the rate equation have been expressed as a function of temperature.     

Early versus delayed angiotensin-converting enzyme inhibition therapy in acute myocardial infarction. The healing and early afterload reducing therapy trial

BACKGROUND: Although ACE inhibitor therapy has been shown to reduce mortality in patients with acute myocardial infarction (MI), the optimal dose and the timing of its initiation have not been determined. METHODS AND RESULTS: In a double-blind trial of 352 patients with anterior MI, we compared the safety and effectiveness of early (day 1) versus delayed (day 14) initiation of the ACE inhibitor ramipril (10 mg) on echocardiographic measures of left ventricular (LV) area and ejection fraction (EF). An early, low-dose ramipril (0.625 mg) arm was also evaluated. Clinical events did not differ. During the first 14 days, the risk of manifesting a systolic arterial pressure of < or = 90 mm Hg was increased in both ramipril groups. LVEF increased in all groups during this period, but the early, full-dose ramipril group had the greatest improvement in EF (increase: full, 4.9 +/- 10.0; low, 3.9 +/- 8.2%; delayed, 2.4 +/- 8.8%; P for trend < .05) and was the only group that did not demonstrate a significant increase in LV diastolic area. CONCLUSIONS: The results of the present study demonstrated that in patients with anterior MI, the early use of ramipril (titrated to 10 mg) attenuated LV remodeling and was associated with a prompter recovery of LVEF. The use of low-dose regimen did not prevent hypotension and had only intermediate benefits on LV size and function. The more favorable effects on LV topography of the early use of full-dose ramipril support the results of the major clinical trials, which have demonstrated an early survival benefit of ACE inhibition.     

Evaluation of hydroconverted residues. Rationalization of analytical data through hydrogen transfer balance

Analytical evaluation of petroleum based materials and processed feeds is a complex task relying on a compromise between tedious in-depth characterizations and fast responding tools for process control. In the present paper, a large number of hydroprocessed vacuum residues, obtained either under catalytic or thermal conditions, have been submitted to the following analytical techniques: Simulated distillation, coupled Simdist/MS, UV spectroscopy, ¹³C NMR, quantitative thin-layer chromatography/FID, vapor phase osmometry. A confrontation of analytical data in the light of correlations with hydrogen transfer evaluation is proposed, which accounts for observed variations in aromatic content. Conradson carbon residue largely influences the results obtained with some of the examined techniques. Apparent discrepancies are rationalized and a strategy for a comprehensive analytical evaluation of hydroprocessed feeds is proposed.     

Templated Grain Growth in Macroporous Materials

We demonstrate a facile method to produce crystallographically textured, macroporous materials using a combination of modified ice templating and templated grain growth (TGG). The process is demonstrated on alumina and the lead‐free piezoelectric material sodium potassium niobate. The method provides macroporous materials with aligned, lamellar ceramic walls which are made up of crystallographically aligned grains. Each method showed that the ceramic walls present a long‐range order over the entire sample dimensions and have crystallographic texture as a result of the TGG process. We also present a modification of the March–Dollase equation to better characterize the overall texture of materials with textured but slightly misaligned walls. The controlled crystallographic and morphologic orientation at two different length scales demonstrated here can be the basis of multifunctional materials.     

Crack Appearance during Drying of an Alumina Gel: Thermo-Hydro-Mechanical Properties

Most heterogeneous catalyst supports used in refineries are composed of porous alumina ceramics. Drying has been identified as a critical process for final product mechanical strength. In the literature, numerous papers deal with drying-induced stresses, which can lead to crack initiation. However, there are few papers devoted to experimental study of drying conditions that promote cracking. The objective of this work is to enhance knowledge of cracking behavior, specifically by studying alumina gel drying. First, the relation between drying conditions and first crack initiation is studied experimentally. Then a complete thermo-hydro-mechanical characterization of the alumina gel is made, including moisture content as a parameter.     

Transmission two-modulator generalized ellipsometry measurements

The two-modulator generalized ellipsometer has been used to measure samples in transmission. In this configuration, the instrument can completely characterize a linear diattenuator and retarder, measuring birefringence, diattenuation, the angle of the principal axis, and the sample depolarization simultaneously and accurately. This instrument can be operated in two modes: (1) spectroscopic, in which measurements are made through the entire sample aperture as a function of wavelength, and (2) spatially resolved, in which measurements are made at a single wavelength and a birefringence picture is made of the sample. Current spatially resolved measurements have been made at a resolution of approximately 40 microm. Four samples have been examined with this instrument: (1) a mica plate, (2) a Polaroid polarizer, and (3) two quartz plates.     

Real‐Time Observation of Order‐Disorder Transformation of Organic Cations Induced Phase Transition and Anomalous Photoluminescence in Hybrid Perovskites

A fundamental understanding of the interplay between the microscopic structure and macroscopic optoelectronic properties of organic‐inorganic hybrid perovskite materials is essential to design new materials and improve device performance. However, how exactly the organic cations affect the structural phase transition and optoelectronic properties of the materials is not well understood. Here, real‐time, in situ temperature‐dependent neutron/X‐ray diffraction and photoluminescence (PL) measurements reveal a transformation of the organic cation CH₃NH₃ ⁺ from order to disorder with increasing temperature in CH₃NH₃PbBr₃ perovskites. The molecular‐level order‐to‐disorder transformation of CH₃NH₃ ⁺ not only leads to an anomalous increase in PL intensity, but also results in a multidomain to single‐domain structural transition. This discovery establishes the important role that organic cation ordering has in dictating structural order and anomalous optoelectronic phenomenon in hybrid perovskites.