The contradictory effect of the methoxy-substituent in palladium-catalyzed ethylene/methyl acrylate cooligomerization.

Two new nonsymmetric bis(aryl-imino)acenaphthene ligands (Ar,Ar'-BIAN) and one symmetric Ar2-BIAN were studied. The three ligands share the presence of at least one methoxy group on one of the two aryl rings. These ligands were used for the synthesis of neutral and monocationic palladium(ii) complexes of general formula [Pd(CH3)Cl(N-N)] and [Pd(CH3)(L)(N-N)][PF6] (N-N = Ar,Ar'-BIAN, Ar2-BIAN; L = CH3CN, dmso). Due to the nonsymmetric nature of the ligands and their coordination to palladium in a nonsymmetric chemical environment, cis and trans isomers are possible for the three series of complexes with Ar,Ar'-BIANs. Both a detailed NMR investigation in solution and the X-ray characterization in the solid state point out that the trans isomer is the preferred species for the neutral derivatives, whereas for the cationic compounds a decrease in the stereoselectivity of the coordination is observed. One of the new Ar,Ar'-BIANs differs from an already reported nonsymmetric α-diimine for the replacement, on one aryl ring, of a methyl group with a methoxy substituent, thus allowing a comparison of the structural features of the relevant complexes. The monocationic complexes were tested as precatalysts for the ethylene/methyl acrylate copolymerization under mild reaction conditions. Despite the structural similarities observed in solution with the already known precatalysts, the present compounds demonstrated a remarkable decrease in the productivity values associated with a higher affinity for the polar monomer.

Dye-sensitized photocatalytic hydrogen production: distinct activity in a glucose derivative of a phenothiazine dye.

A thiophene-based donor-acceptor phenothiazine dye has been functionalized with a peripheral glucose unit (PTZ-GLU) to bust its affinity to water and enhance dye-sensitized photogeneration of hydrogen. Compared to the corresponding alkyl derivative (PTZ-ALK), as well as the common hydrophilic triethylene glycol substitution (PTZ-TEG), the sugar derivative shows a lower contact angle; PTZ-GLU performed twice more efficient than PTZ-TEG in the photogeneration of hydrogen in terms of evolved gas and turnover number.

Highly efficient hydrogen production through ethanol photoreforming by a carbon nanocone/Pd@TiO2 hybrid catalyst.

Production of molecular hydrogen (H2) is becoming an increasingly prominent process, due to high expectations as a new green energy carrier and key reagent for many industrial processes. Herein we report the high efficiency of H2 production via photoreforming of ethanol using a catalyst based on hierarchical carbon nanocones hybridised with an inorganic layer of nanocrystalline TiO2 containing Pd nanoparticles.

Exceptional activity for methane combustion over modular Pd@CeO2 subunits on functionalized Al2O3.

There is a critical need for improved methane-oxidation catalysts to both reduce emissions of methane, a greenhouse gas, and improve the performance of gas turbines. However, materials that are currently available either have low activity below 400°C or are unstable at higher temperatures. Here, we describe a supramolecular approach in which single units composed of a palladium (Pd) core and a ceria (CeO(2)) shell are preorganized in solution and then homogeneously deposited onto a modified hydrophobic alumina. Electron microscopy and other structural methods revealed that the Pd cores remained isolated even after heating the catalyst to 850°C. Enhanced metal-support interactions led to exceptionally high methane oxidation, with complete conversion below 400°C and outstanding thermal stability under demanding conditions.

The role of public participation in public health initiatives: an analysis of the WHO Framework Convention on Tobacco Control.

This is a content analysis of 489 written documents and 142 hearing testimonies, submitted to the World Health Organisation (WHO), regarding the Framework Convention on Tobacco Control (FCTC) during the comment period of 2000. Our aim was to consider the benefits and limitations of inviting public participation. We found that, overall, those who offered commentary were in support of the FCTC and any ensuing treaty, especially if it protected children. The minority who opposed the treaty argued that restrictions on tobacco trade would further damage the economies of poor nations that are financially dependent upon tobacco. The FCTC that was adopted at the World Health Assembly in May 2003 addressed many of the concerns raised by the public in written commentary and hearing testimony: children and youth; advertising and sponsorship; tobacco product labelling; second-hand smoke; taxes; smuggling; liability; tobacco product regulation; and the involvement of non-government organisations (NGOs). We conclude that the benefits of public participation in public health policy formation are numerous, including levelling the playing field for public health activists and NGOs, building the expertise of advocates that can be generalised to other public health efforts, giving the political process legitimacy and credibility, as well as coalition building and grassroots momentum.

Photocatalytic activity of TiO2 doped with boron and vanadium.

Boron (B)- and vanadium (V)-doped TiO(2) photocatalysts were synthesized using modified sol-gel reaction processes and characterized by X-ray diffraction (XRD), Raman spectroscopy and N(2) physisorption (BET). The photocatalytic activities were evaluated by monitoring the degradation of methylene blue (MB). The results showed that the materials possess high surface area. The addition of B favored the transformation of anatase to rutile, while in the presence of V, anatase was the only phase detected. The MB degradation on V-doped TiO(2) was significantly affected by the preparation method. In fact while the presence of V in the bulk did not influence strongly the photoreactivity under visible irradiation, an increase of surface V doping lead to improved photodegradation of MB. The degradation of MB dye indicated that the photocatalytic activities of TiO(2) increased as the boron doping increased, with high conversion efficiency for 9mol% B doping.

Hydrogen adsorption kinetics on Pd/Ce0.8Zr0.2O2.

Hydrogen adsorption on Pd/Ce(0.8)Zr(0.2)O(2) was studied by temperature-programmed reduction, volumetric measurements and IR spectroscopy. Hydrogen uptake and reduction rate at 353 K are strongly dependent on the hydrogen pressure. At relatively high hydrogen partial pressure, reduction involves PdO, the surface and a significant fraction of the bulk of the ceria based oxide. Formation of oxygen vacancies even at low temperature (<373 K) is observed. The hydrogen adsorption process is mainly irreversible, as is shown by an increase in the (2)F(5/2)-->(2)F(7/2) electronic transition of Ce(3+) with hydrogen pressure and surface dehydroxylation. This "severe" reduction has a negative effect on the subsequent hydrogen adsorption capability. The decrease of hydrogen uptake capacity and rate during adsorption can be associated with the partial loss of superficial OH and the presence of Ce(3+), which deactivates Pd electronically.

Multi-level assessment protocol (MAP) for adoption in multi-site clinical trials.

The National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN) is intended to test promising drug abuse treatment models in multi-site clinical trials, and to support adoption of new interventions into clinical practice. Using qualitative research methods we asked: How might the technology of multi-site clinical trials be modified to better support adoption of tested interventions? A total of 42 participants, representing 8 organizational levels ranging from clinic staff to clinical trial leaders, were interviewed about their role in the clinical trial, its interactions with clinics, and intervention adoption. Among eight clinics participating in the clinical trial, we found adoption of the tested intervention in one clinic only. In analysis of interview data we identified four conceptual themes which are likely to affect adoption and may be informative in future multi-site clinical trials. We offer the conclusion that planning for adoption in the early stages of protocol development will better serve the aim of integrating new interventions into practice.

Science in regulatory policy making: case studies in the development of workplace smoking restrictions.

OBJECTIVE: To study the role of science related and other arguments in the development of workplace smoking regulations. DESIGN: Case study, content analysis SUBJECTS: Written commentaries and hearing transcripts on proposed indoor air regulations in Maryland and Washington. MAIN OUTCOME MEASURES: We coded each written commentary and hearing testimony for position toward the regulation, affiliation of the person submitting it, criteria used to evaluate science and scientific, ideological, economic, political, engineering and procedural arguments. RESULTS: In both states, opposition to the regulations came primarily from the tobacco industry, small businesses, and business organisations and appeared to be coordinated. There was little coordination of public health support for the regulations. Arguments about science were used more often by those opposed to the regulations than by those in favour. Supporters emphasised the quantity of the evidence, while opponents criticised its reliability, validity, and quality. Arguments not related to science (61% of total arguments; 459/751), were more common than scientific arguments (39% of total arguments; 292/751). Economic and ideological arguments were used to a similar extent by regulation supporters and opponents. CONCLUSIONS: Advocates can support health related regulations by submitting commentary emphasising the sound research base for regulation and countering criticisms of research. National coordination of these efforts could avoid duplication of effort and make more efficient use of limited public health resources.

Policy makers' perspectives on tobacco control advocates' roles in regulation development.

OBJECTIVE: To identify, from policy makers' perspectives, strategies that enhance tobacco control advocates' effectiveness in the regulatory arena. DESIGN: Key informant interview component of a comparative case study of regulatory agencies in the USA. SUBJECTS: Policy makers involved in the development of four regulatory tobacco control policies (three state and one federal). METHODS: Interviews of policy makers, field notes, and deliberation minutes were coded inductively. RESULTS: Policy makers considered both written commentary and public testimony when developing tobacco control regulations. They triaged written commentary based upon whether the document was from a peer reviewed journal, a summary of research evidence, or from a source considered credible. They coped with in-person testimony by avoiding being diverted from the scientific evidence, and by assessing the presenters' credibility. Policy makers suggested that tobacco control advocates should: present science in a format that is well organised and easily absorbed; engage scientific experts to participate in the regulatory process; and lobby to support the tobacco control efforts of the regulatory agency. CONCLUSIONS: There is an important role for tobacco control advocates in the policy development process in regulatory agencies.

Resist and redirect: physicians respond to breast cancer informed consent legislation.

During the 1980s, former breast cancer patients initiated efforts to introduce Breast Cancer Informed Consent legislation in twenty-two state legislatures. Their general intent in proposing this legislation was to insure that women patients were included in the decision-making process regarding their breast cancer treatment. A qualitative analysis of the reactions of medical professional organizations to these efforts revealed a pattern of change over time. Because professionals were not aware of early efforts for Breast Cancer Informed Consent, these met little or no resistance. Subsequent efforts in the early 1980s were met with organized resistance; physicians' organizations responded to the legislation as if it were a threat to their professional autonomy. By the middle of the decade, professionals had co-opted the efforts, shaping the legislation to their benefit. The challenge to physician authority that former breast cancer patients mounted had mixed results, but ultimately illustrated that professions are quite effective at retaining power.

[The attitude and vaccination practice of a sample of Campania pediatricians]. / Orientamento e pratica vaccinale di un campione di pediatri campani.

One hundred-twenty-six pediatricians were questioned about their attitudes concerning the practice of immunization, their feelings about the new vaccines (measles, mumps, german measles, hepatitis b) and about the pertussis vaccine. 80% of them reported that indications and contraindications were still unclear: Down's syndrome and atopic eczema are still thought to be real contraindications--despite the mass of papers suggesting that they are not so--, moreover 95% of the participants persists into the unnecessary evaluation of the antibody title following hepatitis b immunization. We conclude that it would be wise to periodically diffuse to pediatricians update recommendations about the extended immunization program, especially in our region, were still an high number of children are not properly immunized.