Organic sulfur biodesulfurization in non-aqueous media

An alternative approach to water-based biodesulfurization systems was examined employing organic solvent-based reaction media. A gram-position microorganism, FE-9, was developed to function biocatalytically against organic sulfur-containing heterocycles in 100% dimethylformamide. Strain FE-9 converted dibenzothiophene to biphenyl and hydrogen sulfide under a hydrogen atmosphere, and to biphenyl, hydroxybiphenyl and sulfate under an air atmosphere. Thianthrene was converted to benzene and hydrogen sulfide under a hydrogen atmosphere, and to benzene and sulfate under an air atmosphere. The bioconversion of sulfur-containing heterocycles to aromatic hydrocarbons and hydrogen sulfide, and the oxidation of sulfide to sulfate under air, appears to represent two different biochemical events occurring in dimethylformamide. These studies indicate a strong potential for the development of biocatalysts that selectively abstract organosulfur from high-sulfur containing fossil fuels in an organic solvent-based reaction medium.     

Cognitive processes in normal and hyperactive children and their response to amphetamine treatment.

14 normal (mean age 10.1 yrs) and 15 hyperactive (mean age 9.4 yrs) children were compared on cognitive tasks following placebo or amphetamine administration (.5 mg/kg) in a double-blind crossover study. A no-treatment control group of normal children who were matched with the hyperactive Ss on age, IQ, and socioeconomic status were also tested on the cognitive measures. In the undrugged state, normals remembered more information under free-recall retrieval conditions than did hyperactives; cued recall did not differentiate between the 2 groups. Both normals and hyperactives demonstrated similar, amphetamine-related increases in the recall of semantically and acoustically processed words. This enhancement of cognition occurred along with improvements in attention but was independent of such attentional changes. The pattern of amphetamine-induced changes in cognition is generally similar in normal and hyperactive children. Differences in response to amphetamine that do appear involve components of cognition that distinguish these children in the undrugged state (e.g., semantic processing, organization in recall, and free retrieval of information). (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The evolution of the Hox cluster: insights from outgroups

When a tumor or other heterogeneous cell population is acutely exposed to ionizing radiation (or, for that matter, to chemotherapeutic agents or hyperthermia), cells that happen to be more sensitive will be preferentially removed, leaving behind a population more resistant as a whole. However, under broadly applicable assumptions, we here demonstrate mathematically that there is a natural tendency of the postirradiation population to recover from the irradiation in such a manner as to restore its original sensitivity composition, i.e. to undergo "resensitization". An important consequence in radiotherapy is that, if a fixed total radiation dose is delivered in a more protracted manner, e.g. as several fractions or as a continuous dose at low dose rate, resensitization occurring over the course of dose delivery will result in greater cell killing than would otherwise have occurred. That is, for a cell population with any form of diversity in radiosensitivity, the influence of redistribution is to make any prolonged dose more damaging than an acute dose of the same magnitude. This tendency toward an "inverse dose-rate effect" may be masked in practice by countervailing effects, such as repair of sublethal damage, but the tendency is demonstrated to hold under very general circumstances, being a consequence of cell-cell diversity and the dynamic response of the cell population to treatment.     

Medical illness burden, trait neuroticism, and depression in older primary care patients

OBJECTIVE: The authors tested the hypotheses that medical illness burden is independently associated with depression and that this association is moderated by neuroticism. METHOD: Multiple regression techniques were used to determine the independent associations of medical burden and neuroticism with depression in a group of 196 subjects, 60 years of age and older, recruited from primary care settings. RESULTS: Medical burden and neuroticism were independently associated with major depression, depressive symptoms, and psychiatric dysfunction. CONCLUSIONS: These findings support models in which medical disorders may contribute directly to depression. At the same time, the role of neuroticism in later-life depression warrants further study.     

Mechanisms of spray formation and combustion from a multi-hole injector with E85 and gasoline

The spray formation and combustion characteristics of gasoline and E85 (85% ethanol, 15% gasoline) have been investigated using a multi-hole injector with asymmetric nozzle-hole arrangement. Experiments were carried out in a quiescent optical chamber using high-speed shadowgraphy (9 kHz) to characterise the spray sensitivity to both injector temperature and ambient pressure in the range of 20-120 °C and 0.5, 1.0 bar. Spray-tip penetrations and ‘umbrella’ spray cone angles were calculated for all conditions. Phase Doppler Anemometry was also used to measure droplet sizes in the core of one of the spray plumes, 25 mm below the injector tip. To study the effect of fuel properties on vaporisation and mixture preparation under realistic operating conditions, a separate set of experiments was carried out in a direct-injection spark-ignition optical engine. The engine was run at 1500 RPM under cold and fully warmed-up conditions (20 °C and 90 °C) at part load and full load (0.5 and 1.0 bar intake pressure). Floodlit laser Mie-scattering images of the sprays on two orthogonal planes corresponding to the swirl and tumble planes of in-cylinder flow motion were acquired to study the full injection event and post-injection mixing stage. These were used to make comparisons with the static chamber sprays and to quantify the liquid-to-vapour phase evaporation process for both fuels by calculating the projected ‘footprint’ of the sprays at different conditions. Analysis of the macroscopic structure and turbulent primary break-up properties of the sprays was undertaken in light of jet exit conditions described in terms of non-dimensional numbers. The effects on stoichiometric combustion were investigated by imaging the natural flame chemiluminescence through the engine’s piston crown (swirl plane) and by post-processing to derive flame growth rates and trajectories of flame motion.     

Safeguarding the public's trust through the self-governance of peer review

1. Nurses must monitor the quality of professional practice in order to safeguard the public's trust in nursing as a professional discipline and to ensure that nursing is self-regulating, accountable, and autonomous. 2. A peer review process indicates self-governance and advances the profession of nursing. 3. A peer review committee is responsible for gathering information, evaluating nursing practice, and reporting the findings to the nurse and the initiator of the review. Any deliberate or negligent acts or omissions of the nurse under review are reported to the state board of nursing.     

Isothermal models for anode-supported tubular solid oxide fuel cells

Modeling of solid oxide fuel cells (SOFCs) has gained considerable significance in recent years. A detailed phenomenological model for SOFC can be used to understand performance limitations, optimization, in situ diagnostics and control. In this paper, we study the transport and various electrochemical phenomena in an anode-supported tubular SOFC using a steady-state model. In particular, we discuss the importance of modeling different phenomena vis-a-vis their impact on the prediction capability of the model. It is observed that even a reasonably simple model can be sufficiently predictive in a particular operating range. As the operating range of the cell is increased, the predictive capability of a model validated in a narrow range cannot be guarantied. It has also been observed that neglecting momentum conservation in the model for a tubular SOFC can affect the predictive capability of the model at higher overpotentials. An extensively validated model is used to study the percentage conversion of oxygen and oxygen concentration profile within a cell at different operating conditions. All of the simulation studies are supported by experimental data that spans a wide range of operation in terms of the DC polarization, reactant flow rates and operating temperatures.