Synthesis of Robust Hierarchical Silica Monoliths by Surface-Mediated Solution/Precipitation Reactions over Different Scales: Designing Capillary Microreactors for Environmental Applications

A synthetic procedure to prepare novel materials (surface-mediated fillings) based on robust hierarchical monoliths is reported. The methodology includes the deposition of a (micro- or mesoporous) silica thin film on the support followed by growth of a porous monolithic SiO2 structure. It has been demonstrated that this synthesis is viable for supports of different chemical nature with different inner diameters without shrinkage of the silica filling. The formation mechanism of the surface-mediated fillings is based on a solution/precipitation process and the anchoring of the silica filling to the deposited thin film. The interaction between the two SiO2 structures (monolith and thin film) depends on the porosity of the thin film and yields composite materials with different mechanical stability. By this procedure, capillary microreactors have been prepared and have been proved to be highly active and selective in the total and preferential oxidation of carbon monoxide (TOxCO and PrOxCO).

An Acyl-NHC Osmium Cooperative System: Coordination of Small Molecules and Heterolytic B–H and O–H Bond Activation

The hexahydride complex OsH6(PiPr3)2 (1) activates the C–OMe bond of 1-(2-methoxy-2-oxoethyl)-3-methylimidazolium chloride (2), in addition to promoting the direct metalation of the imidazolium group, to afford a five-coordinate OsCl(acyl-NHC)(PiPr3)2 (3) compound. The latter coordinates carbon monoxide, oxygen, and molecular hydrogen to give the corresponding carbonyl (4), dioxygen (5), and dihydrogen (6) derivatives. Complex 3 also promotes the heterolytic bond activation of pinacolborane (HBpin), using the acyl oxygen atom as a pendant Lewis base. The hydride ligand and the Bpin substituent of the Fischer-type carbene of the resulting complex 7 activate the O–H bond of alcohols and water. As a consequence, complex 3 is a metal ligand cooperating catalyst for the generation of molecular hydrogen, by means of both the alcoholysis and hydrolysis of pinacolborane, via the intermediates 7 and 6.

Encefalopatia tardia da entoxicação por monóxido de carbono : case report e revisão de literatura

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Composition of basalts from the north part of the Bougault anomaly, Mid-Atlantic Ridge 15°N

A quantitative model of development of magmatic and ore-magmatic systems under crests of mid-ocean ridges is constructed. Correct physical models of melting zone formation in approximation to active spreading, non-stationary dynamics of magma intrusion from a center of generation, filling of magma chambers of various shapes, feeding of fissure-type volcanoes, and retrograde boiling of melts during solidification of intrusive bodies beneath axial zones of spreading in crests of ridges are proposed. Physicochemical and mathematical theories of disintegration of multi-component solutions, growth of liquational drops of ore melts, and sublimation of components from magmatic gases are elaborated. Methods for constructing physically correct models of heat and mass transfer in heterophase media are devised. Modeling of development of magmatic and ore-magmatic systems on the basis of the Usov-Kuznetsov facies method and the Pospelov system approach are advanced. For quantitative models numerical circuits are developed and numerical experiments are carried out.

Measurement of vehicle contamination by exhaust gases. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Toxic gases in heavy duty diesel truck cabs. Final report.

Federal Highway Administration, Washington, D.C.

Scientific report : RF Project 464 /

1. The determination and interpretation of electronic collision cross sections -- 2. An electron spectrometer for the study of inelastic collision cross sections -- 3. The inelastic scattering of electrons by helium -- 4. Inelastic collision cross sections of carbon monoxide -- 5. An electron impact study of nitrogen in the kinetic energy range 400 to 600 volts -- 6. Electronic collision cross sections and oscillator strengths for oxygen in the Schumann-Runge region -- 7. Electronic collision cross sections for oxygen at excitation energies above 10 volts -- 8. Electronic collsion cross sections for nitrogen at excitation energies from 10 to 80 electron volts -- 9. Additional collision cross sections for helium, especially in the ionized continuum -- 10. A collision cross section study of CO₂, with a theoretical study of two transitions -- 11. Further developments in the theory and use of the electron spectrometer -- 12. Electronic collision cross sections of water vapor.

The oxidation of hydrogen,

Mode of access: Internet.

Essays on Environmental and Health Economics

Thesis (Ph.D.)--University of Washington, 2016-06

Performance of hydrophobic and hydrophilic silica membrane reactors for the water gas shift reaction

In this study, a novel molecular sieve silica (MSS) membrane packed bed reactor (PBR) using a Cu/ZnO/Al2O3 catalyst was applied to the low-temperature water gas shift reaction (WGS). Best permeation results were H-2 permeances of 1.5 x 10(-6) mol(.)s(-1) m(-2) Pa-1, H-2/CO2 selectivities of 8 and H-2/N-2 selectivities of 18. It was shown that an operation with a sweep gas flow of 80 cm 3 min(-1), a feed flow rate of 50 cm(3) min(-1) and a H2O/CO molar ratio of one at 280 degreesC reached a 99% CO conversion. This is well above the thermodynamic equilibrium and achievable PBR conversion. Hydrophilic membranes underwent pore widening during the reaction while hydrophobic membranes indicated no such behaviour and also showed increased H-2 permeation with temperature, a characteristic of activated transport. (C) 2003 Elsevier Science B.V. All rights reserved.

Cardiovascular implications of exposure to traffic air pollution during exercise

Regular aerobic exercise is recommended by physicians to improve health and longevity. However, individuals exercising in urban regions are often in contact with air pollution, which includes particles and gases associated with respiratory disease and cancer. We describe the recent evidence on the cardiovascular effects of air pollution, and the implications of exercising in polluted environments, with a view to informing clinicians and other health professionals. There is now strong evidence that fine and ultra fine particulate matter present in air pollution increases cardiovascular morbidity and mortality. The main mechanisms of disease appear to be related to an increase in the pathogenic processes associated with atherosclerosis. People exercising in environments pervaded by air contaminants are probably at increased risk, due to an exercise-induced amplification in respiratory uptake, lung deposition and toxicity of inhaled pollutants. We make evidence-based recommendations for minimizing exposure to air-borne toxins while exercising, and suggest that this advice be passed on to patients where appropriate.

Effectiveness of hospital-based smoking cessation

Study objectives: Smoking cessation for current smokers is a health-care imperative. It is not clear which approaches to smoking cessation are the most effective in the hospital setting and which factors predict long-term abstinence. We hypothesized that a hospital-based smoking cessation program involving behavioral modification and support would provide an effective intervention for smoking cessation. Design: Prospective cohort study. Setting: Smoking cessation clinics in a tertiary referral, cardiothoracic hospital. Patients or participants: Two hundred forty-three smokers and 187 never-smoker control subjects. Interventions: Smokers underwent specific sessions of individual counseling on behavioral modification, including written information, advice about quit aids, and support during the quit attempt. Abstinence was confirmed by exhaled carbon monoxide measurements. Measurements and results: Compared to never-smoker control subjects, smokers were more likely to have grown up with a smoking father or siblings, and to currently live or socialize with other smokers. Two hundred sixteen smokers attended at least two sessions of the smoking cessation program. Of these, 25% were unavailable for follow-up at 12 months and were assumed to be smoking. The point prevalence abstinence rate at 12 months was 32%. Independent factors associated with abstinence at 12 months were self-belief in quitting ability, having a heart condition, growing up without siblings who smoked, and increasing number of pack-years. Conclusions: This prospective study has demonstrated that this hospital-based smoking cessation program was as effective as programs in other settings. Social and psychological factors were associated with a greater chance of abstinence.

Calibration of the channel that determines the omega-hydroxylation regiospecificity of cytochrome P4504A1 - Catalytic oxidation of 12-halododecanoic acids

The fatty acid omega-hydroxylation regiospecificity of CYP4 enzymes may result from presentation of the terminal carbon to the oxidizing species via a narrow channel that restricts access to the other carbon atoms. To test this hypothesis, the oxidation of 12-iodo-, 12-bromo-, and 12-chlorododecanoic acids by recombinant CYP4A1 has been examined. Although all three 12-halododecanoic acids bind to CYP4A1 with similar dissociation constants, the 12-chloro and 12-bromo fatty acids are oxidized to 12-hydroxydodecanoic acid and 12-oxododecanoic acid, whereas the 12-iodo analogue is very poorly oxidized. Incubations in (H2O)-O-18 show that the 12-hydroxydodecanoic acid oxygen derives from water, whereas that in the aldehyde derives from O-2. The alcohol thus arises from oxidation of the halide to an oxohalonium species that is hydrolyzed by water, whereas the aldehyde arises by a conventional carbon hydroxylation-elimination mechanism. No irreversible inactivation of CYP4A1 is observed during 12-halododecanoic acid oxidation. Control experiments show that CYP2E1, which has an omega-1 regiospecificity, primarily oxidizes 12-halododecanoic acids to the omega-aldehyde rather than alcohol product. Incubation of CYP4A1 with 12,12-[H-2](2)-12-chlorododecanoic acid causes a 2-3-fold increase in halogen versus carbon oxidation. The fact that the order of substrate oxidation (Br > Cl >> I) approximates the inverse of the intrinsic oxidizability of the halogen atoms is consistent with presentation of the halide terminus via a channel that accommodates the chloride and bromide but not iodide atoms, which implies an effective channel diameter greater than 3.90 angstrom but smaller than 4.30 angstrom.

Smoking and schizophrenia: is symptom profile related to smoking and which antipsychotic medication is of benefit in reducing cigarette use?

Smoking rate is disproportionately high among patients with schizophrenia, resulting in significant morbidity and mortality. However, cigarette smoking has been reported to have beneficial effects on negative symptoms, extrapyramidal symptoms, cognitive functioning and mood symptoms. Therefore, smoking cessation may worsen disability in schizophrenia. The association between smoking and these key clinical parameters was examined. Additionally, severity of smoking across four different antipsychotic treatment groups was explored. One hundred and forty-six patients with schizophrenia were assessed for smoking using expired carbon monoxide and smoking history. They were administered the Positive and Negative Symptom Scale, The Extrapyramidal Symptom Rating Scale, the Barnes Akathisia Rating Scale, Reitans Trail-making Test (A and B) and General Health Questionnaire-28. There was no difference in the chlorpromazine equivalent dose of any of the medications studied. Atypical agents were associated with significantly lower levels of smoking when compared with typical medications. There was no difference in smoking severity between the individual atypical medications examined. Similarly, there were no significant differences between smoking and non-smoking groups with regard to Positive and Negative Symptom Scale, Extrapyramidal Symptom Rating Scale, Trail-making Test and General Health Questionnaire-28. However, there was a significant difference between these groups with the smoking group demonstrating less akathisia. Smoking is not associated with positive, negative cognitive and mood symptoms in schizophrenia. Smoking is associated with lower levels of antipsychotic induced akathisia. Clinicians should not be discouraged from helping patients stop smoking for fear of worsening symptoms. However, akathisia may emerge upon cessation of smoking. Switching patients from typical to atypical antipsychotics may assist patients with schizophrenia to give up smoking.