Preventing Zoonotic Influenza Virus Infection

We evaluated 49 swine industry workers and 79 nonexposed controls for antibodies to swine influenza viruses. Multivariate modeling showed that workers who seldom used gloves (odds ratio [OR] 30.3) or who smoked (OR 18.7) most frequently had evidence of previous H1N1 swine virus. These findings may be valuable in planning for pandemic influenza

Science and Technology Issues in the 115th Congress

Science and technology (S&T) have a pervasive influence over a wide range of issues confronting the nation. Public and private research and development spur scientific and technological advancement. Such advances can drive economic growth, help address national priorities, and improve health and quality of life. The constantly changing nature and ubiquity of science and technology frequently create public policy issues of congressional interest. The federal government supports scientific and technological advancement directly by funding and performing research and development and indirectly by creating and maintaining policies that encourage private sector efforts. Additionally, the federal government establishes and enforces regulatory frameworks governing many aspects of S&T activities. This report briefly outlines an array of science and technology policy issues that may come before the 115th Congress. Given the rapid pace of S&T advancement and its importance in many diverse public policy issues, S&T-related issues not discussed in this report may come before the 115th Congress. The selected issues are grouped into 9 categories: - Overarching S&T Policy Issues, - Agriculture, - Biomedical Research and Development, - Defense, - Energy, - Environment and Natural Resources, - Homeland Security, - Information Technology, - Physical and Material Sciences, and - Space. Each of these categories includes concise analysis of multiple policy issues. The material presented in this report should be viewed as illustrative rather than comprehensive. Each section identifies CRS reports, when available, and the appropriate CRS experts to contact for further information and analysis

Application of silver in microtubular solid oxide fuel cells

In this paper, the behaviour of silver as cathode conductive material, interconnect wire, and sealing for anode lead connection for microtubular solid oxide fuel cells (µSOFC) is reported. The changes in silver morphology are examined by scanning electron microscopy on cells that had been operated under reformed methane. It is found that using silver in an solid oxide fuel cell (SOFC) stack can improve the cell performance. However, it is also concluded that silver may be responsible for cell degradation. This report brings together and explains all the known problems with application of silver for SOFCs. The results show that silver is unstable in interconnect and in cathode environments. It is found that the process of cell passivation/activation promotes silver migration. The difference in thermal expansion of silver and sealant results in damage to the glass. It is concluded that when silver is exposed to a dual atmosphere condition, high levels of porosity formation is seen in the dense silver interconnect. The relevance of application of silver in SOFC stacks is discussed

Cellobiose Dehydrogenase Aryl Diazonium Modified Single Walled Carbon Nanotubes: Enhanced Direct Electron Transfer through a Positively Charged Surface

One of the challenges in the field of biosensors and biofuel cells is to establish a highly efficient electron transfer rate between the active site of redox enzymes and electrodes to fully access the catalytic potential of the biocatalyst and achieve high current densities. We report on very efficient direct electron transfer (DET) between cellobiose dehydrogenase (CDH) from Phanerochaete sordida (PsCDH) and surface modified single walled carbon nanotubes (SWCNT). Sonicated SWCNTs were adsorbed on the top of glassy carbon electrodes and modified with aryl diazonium salts generated in situ from p-aminobenzoic acid and p-phenylenediamine, thus featuring at acidic pH (3.5 and 4.5) negative or positive surface charges. After adsorption of PsCDH, both electrode types showed excellent long-term stability and very efficient DET. The modified electrode presenting p-aminophenyl groups produced a DET current density of 500,mu A cm(-2) at 200 mV vs normal hydrogen reference electrode (NHE) in a 5 mM lactose solution buffered at pH 3.5. This is the highest reported DET value so far using a CDH modified electrode and comes close to electrodes using mediated electron transfer. Moreover, the onset of the electrocatalytic current for lactose oxidation started at 70 mV vs NHE, a potential which is 50 mV lower compared to when unmodified SWCNTs were used. This effect potentially reduces the interference by oxidizable matrix components in biosensors and increases the open circuit potential in biofuel cells. The stability of the electrode was greatly increased compared with unmodified but cross-linked SWCNTs electrodes and lost only 15% of the initial current after 50 h of constant potential scanning

Water oxidation at hematite photoelectrodes: the role of surface states

Hematite (α-Fe2O3) constitutes one of the most promising semiconductor materials for the conversion of sunlight into chemical fuels by water splitting. Its inherent drawbacks related to the long penetration depth of light and poor charge carrier conductivity are being progressively overcome by employing nanostructuring strategies and improved catalysts. However, the physical–chemical mechanisms responsible for the photoelectrochemical performance of this material (J(V) response) are still poorly understood. In the present study we prepared thin film hematite electrodes by atomic layer deposition to study the photoelectrochemical properties of this material under water-splitting conditions. We employed impedance spectroscopy to determine the main steps involved in photocurrent production at different conditions of voltage, light intensity, and electrolyte pH. A general physical model is proposed, which includes the existence of a surface state at the semiconductor/liquid interface where holes accumulate. The strong correlation between the charging of this state with the charge transfer resistance and the photocurrent onset provides new evidence of the accumulation of holes in surface states at the semiconductor/electrolyte interface, which are responsible for water oxidation. The charging of this surface state under illumination is also related to the shift of the measured flat-band potential. These findings demonstrate the utility of impedance spectroscopy in investigations of hematite electrodes to provide key parameters of photoelectrodes with a relatively simple measurement

Physicochemical Characterization of Passive Films and Corrosion Layers by Differential Admittance and Photocurrent Spectroscopy

Two different electrochemical techniques, differential admittance and photocurrent spectroscopy, for the characterization of electronic and solid state properties of passive films and corrosion layers are described and critically evaluated. In order to get information on the electronic properties of passive film and corrosion layers as well as the necessary information to locate the characteristic energy levels of the passive film/electrolyte junction like: flat band potential (Ufb), conduction band edge (EC) or valence band edge (EV), a wide use of Mott-Schottky plots is usually reported in corrosion science and passivity studies. It has been shown, in several papers, that the use of simple M-S theory to get information on the electronic properties and energy levels location at the film/electrolyte interface can be seriously misleading and/or conflicting with the physical basis underlying the M-S theory. A critical appraisal of this approach to the study of very thin and thick anodic passive film grown on base-metals (Cr, Ni, Fe, SS etc..) or on valve metals (Ta, Nb, W etc..) is reported in this work, together with possible alternative approach to overcome some of the mentioned inconsistencies. At this aim the theory of amorphous semiconductor Schottky barrier, introduced several years ago in the study of passive film/electrolyte junction, is reviewed by taking into account some of the more recent results obtained by the present authors. Future developments of the theory appears necessary to get more exact quantitative information on the electronic properties of passive films, specially in the case of very thin film like those formed on base metals and their alloys. The second technique described in this chapter, devoted to the physico-chemical characterization of passive film and corrosion layers, is a more recent technique based on the analysis of the photo-electrochemical answer of passive film/electrolyte junction under illumination with photons having suitable energy. Such a technique usually referred to as Photocurrent Spectroscopy (PCS) has been developed on the basis of the large research effort carried out by several groups in the 1970’s and aimed to investigate the possible conversion of solar energy by means of electrochemical cells. In this work the fundamentals of semiconductor/electrolyte junctions under illumination will be highlighted both for crystalline and amorphous materials. The role of amorphous nature and film thickness on the photo-electrochemical answer of passive film/solution interface is reviewed as well the use of PCS for quantitative analysis of the film composition based on a semi-empirical correlation between optical band gap and difference of electronegativity of film constituents previously suggested by the present authors. In this frame the results of PCS studies on valve metal oxides and valve metal mixed oxides will be discussed in order to show the validity of the proposed method. The results of PCS studies aimed to get information on passive film composition and carried out by different authors on base metals (Fe, Cr, Ni) and their alloys, including stainless steel, will be also compared with compositional analysis carried out by well-established surface analysis techniques

A 2 × 2 factorial, randomised, open-label trial to determine the clinical and cost-effectiveness of hypertonic saline (HTS 6%) and carbocisteine for airway clearance versus usual care over 52 weeks in adults with bronchiectasis:a protocol for the CLEAR clinical trial

Background: Current guidelines for the management of bronchiectasis (BE) highlight the lack of evidence to recommend mucoactive agents, such as hypertonic saline (HTS) and carbocisteine, to aid sputum removal as part of standard care. We hypothesise that mucoactive agents (HTS or carbocisteine, or a combination) are effective in reducing exacerbations over a 52-week period, compared to usual care. Methods: This is a 52-week, 2 × 2 factorial, randomized, open-label trial to determine the clinical effectiveness and cost effectiveness of HTS 6% and carbocisteine for airway clearance versus usual care-the Clinical and cost-effectiveness of hypertonic saline (HTS 6%) and carbocisteine for airway clearance versus usual care (CLEAR) trial. Patients will be randomised to (1) standard care and twice-daily nebulised HTS (6%), (2) standard care and carbocisteine (750 mg three times per day until visit 3, reducing to 750 mg twice per day), (3) standard care and combination of twice-daily nebulised HTS and carbocisteine, or (4) standard care. The primary outcome is the mean number of exacerbations over 52 weeks. Key inclusion criteria are as follows: Adults with a diagnosis of BE on computed tomography, BE as the primary respiratory diagnosis, and two or more pulmonary exacerbations in the last year requiring antibiotics and production of daily sputum. Discussion: This trial's pragmatic research design avoids the significant costs associated with double-blind trials whilst optimising rigour in other areas of trial delivery. The CLEAR trial will provide evidence as to whether HTS, carbocisteine or both are effective and cost effective for patients with BE. Trial registration: EudraCT number: 2017-000664-14 (first entered in the database on 20 October 2017). ISRCTN.com, ISRCTN89040295. Registered on 6 July/2018. Funder: National Institute for Health Research, Health Technology Assessment Programme (15/100/01). Sponsor: Belfast Health and Social Care Trust. Ethics Reference Number: 17/NE/0339. Protocol version: V3.0 Final_14052018