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Abstract: The ability to control and orientate chemical reactivity in the condensed phase is a major challenge of modern research. Upon interaction with condensed molecules electrons drive bond cleavage thus generating a population of very reactive species in the condensed medium. These reactive species may interact either within the volume leading to the synthesis of new molecules or with the substrate surface by forming strong chemical bonds. The former reaction is known as electron induced synthesis and the latter one as electron induced surface functionalization. High-energy electrons achieve only a low chemical specificity due to the large number of dissociating open channels. In contrast, electrons with energies below ionization threshold of the irradiated matter are capable of high selectivity because of the dissociative electron attachment mechanism. In this review recent studies of electron interaction with condensed molecules on hydrogenated diamond substrates will be described. In particular electron induced functionalization of diamond surfaces by CH2CN groups, decarboxylation reactions in condensed films of pure organic acids RCOOH (R=H, CH3, C2H5, CF3), carbamic acid formation in CO2:NH3, HCOOH:NH3 and CF3COOH:NH3 binary ice mixtures, and glycine formation in a CH3COOD:NH3 mixture are presented and discussed. [Copyright &y& Elsevier]

Abstract: Plasma hydrogenation of polycrystalline diamond films results in a fully hydrogenated well-ordered diamond surface and etching of the amorphous phase located at grain boundaries. Vacuum annealing to 1000 °C followed by in-situ hydrogenation by thermal activated hydrogen of the bared diamond surface results in the formation of sp3-CH x adsorbed groups located on the top surface. Annealing of the in-situ hydrogenated surface to 600 °C results in desorption of these species and partial reconstruction of the film surface. Some irreversible surface degradation was detected in the in-situ annealed and hydrogenated surface compared to the state of the surface obtained upon plasma hydrogenation. [Copyright &y& Elsevier]

Abstract: The interaction between low energy electrons and condensed acetic acid has been investigated considering H− and D− ions Electron Stimulated Desorption from the three isotopic forms CD3COOD, CD3COOH and CH3COOD. For all isotopic forms the yields of desorbing H−(D−) ions are nearly identical, peaking at an incident electron energy of ∼9.75eV, and no differences are observed in H−(D−) kinetic energy distributions. The intensities of H− and D− ion signals from CD3COOH and CH3COOD suggest a selectivity in the production of ions, that seems more efficient from the acid group –COOH(D) than from the methyl group –CH(D)3 of these molecules. [Copyright &y& Elsevier]

BACKGROUND/OBJECTIVES: The U.S. is experiencing a national epidemic of obesity. Currently 5 % of the population is considered morbidly obese (body mass index [BMI] >40 kg/m2) and bariatric surgery has become popular as an effective therapy for morbid obesity. The term bariatric surgery encompasses a variety of surgical procedures and there is limited published infection data. Our institution established a Bariatric and Metabolic Institute in 2004 and surveillance for surgical site infections (SSI) and bloodstream infections (BSI) was initiated July 1, 2005. METHODS: Laparoscopic bariatric procedures were categorized as Roux-en-Y gastric bypass (RYGB); gastric banding; and sleeve gastrectomy. CDC definitions were used for superficial, deep and organ space SSI, as well as for BSI. Case ascertainment was performed by rounding on the bariatric unit, review of laboratory culture reports and communication with the Bariatric Center. A laparoscopic procedure that during the course of surgery is changed to an open laparotomy is considered a conversion. RESULTS: 161 procedures were performed by 2 surgeons from July 1, through December 31, 2005. Of these 73% (117/161) were RYGB; 22% (35/161) were gastric banding; and 5% (9/161) sleeve gastrectomies. In the RYGB group there were a total of 5 SSIs with an overall infection incidence rate of 4.3%. Four infections were organ space and one superficial. Sixty percent of SSI cases were polymicrobial (3/5). Gram positive organisms constituted 63% of pathogens. Pathogens included Streptococcus milleri (2), Enterococcus (1), Streptococcus viridans (1), Escherichia coli (1), Bacteroides fragilis (1) and Lactobacillus (1). In one case no pathogen was identified. Of the 5 patients with SSI, 3 were male. The mean age was 46.6 years (range 35 - 53 years), with a mean BMI of 49.8 (range 38-66). The mean duration of surgery was 353 minutes (range of 260-464 minutes). Pre-operative Cefazolin was given within 60 minutes of incision time in all but one infected case. Routine antibiotic orders are for cefazolin 1 gram IV every eight hours for 24 hours. There was an anastomotic leak noted in 80% of SSIs. There were no infections in the gastric banding and sleeve gastrectomy cases. The conversion rate for laparoscopic RYGB to open laparotomy was 0.9% (1/117). There were no BSIs. CONCLUSIONS: A six month summary of our bariatric surgical center data revealed a significant number of bariatric cases with RYGB the most commonly performed procedure. The SSI infection rate of 4.3% is within the range of 1-10% reported in the literature. The rate for Laparoscopic RYGB conversion to a laparotomy is 0.9%. [Copyright &y& Elsevier]

ISSUE: The Advisory Committee on Immunization Practices (ACIP) and the Healthcare Infection Control Practices Advisory Committee (HICPAC) emphasize HCW vaccination against influenza to prevent disease and transmission to patients. Despite education, incentives and easy access to vaccine our influenza vaccine coverage rate for nearly 20,000 HCWs was 38% in 2004. Because mandatory vaccination was met with resistance due to the perception of coercion, we opted for a strategy of mandatory participation with documentation of declination using the intranet as a tool. PROJECT: To establish an intranet web site where employees were required to document participation, declination or vaccination. The site was accessible on all computers and work stations. Employees logged on using their identification number and selected vaccine received, vaccine contraindicated or vaccine declined. Declining employees automatically received education about vaccination. A Microsoft® Structured Query Language database was created and linked to a Human Resource database. Administrators were provided feedback on participation rates. The site provided information about where to obtain vaccine, and a place to ask questions linked by e-mail to an Infection Control Practitioner for prompt response. Employees were notified of the program via letter. Reminders were provided through managers and newsletters. Vaccination rates were not provided to managers or administrators. The site was activated October 17, 2005. RESULTS: As of December 1, 2005, 79% of employees (16,138 / 20,361) participated by accessing the intranet: 50% (10,291) indicated vaccine received; 25.9% (5269) declined; 2.8% (578) declined based on contraindications. Self-reported vaccination included 50% of the Division of Medicine and 45% of the Division of Nursing. Declination was 21% and 30% respectively. Departmental data is available for all patient care locations. There were few complaints as employees understood vaccination data was confidential. LESSONS LEARNED: The intranet provided an inexpensive tool for measuring and timely reporting of HCW participation, declination and vaccination rates. Data management was accomplished without significant expense and cumbersome paperwork. The site provided education to large numbers of employees which may have influenced the increase in the vaccination rate. Real time monitoring by location or occupation allows for targeting interventions where rates are low. Detailed departmental data allows for planning future targeted educational programs. The same tool can be used to document other programs such as fit-testing and TB screening. [Copyright &y& Elsevier]

Hydrogen embrittlement (HE) of steels in the presence of gaseous hydrogen poses a challenge to the safe transportation of hydrogen through pipelines. The use of sub-size specimens machined from coupons extracted from pipes is proposed for monitoring the degradation of material properties over the entire operational life. The objective of this paper is to present a methodology based on the sub-size specimens using a machine developed to operate with a small volume of gaseous hydrogen, up to a pressure of 250 bars, and test control using Edge Tracing (ET) technique. Tensile and toughness mini-specimens extracted from a E355 mod. steel grade are employed for this study. Reliable results are obtained using tensile mini-specimens with 1.2 and 2.4 mm diameters, tested under both air and gaseous H 2. Toughness tests are conducted using mini-specimens with a thickness of 5 mm. These tests monitored the Load Line Opening Displacement (LLOD) and the Opening Angle are monitored during the tests through ET technique, allowing for the determination of J − Δ a and δ − Δ a plots under both air and gaseous H 2 conditions. The results uncover the impact of H 2 pressure and specimen dimensions on hydrogen embrittlement, leading to the computation of Hydrogen Embrittlement Indexes through various methods. The insights gained from this study establish the necessary foundations for the utilization of mini-specimens in characterizing hydrogen embrittlement. • A novel mini-specimen testing method measuring local strains using optical technique. • Mini-specimens provide reliable tensile results across different specimen sizes. • Tensile tests at different H2 pressures offer insights into HE via local indexes HEIZ. • Impact of H2 pressure on material toughness assessment using J Q and CTOD indexes. • Method enables broader studies, key for hydrogen transport pipelines. [ABSTRACT FROM AUTHOR]

Abstract: In most organisms, mitochondrial creatine kinase (MtCK) is present as dimers and octamers with the latter predominating under physiological conditions. An absolutely conserved tryptophan residue (Trp-264 in chicken sarcomeric MtCK) appears to play a key role in octamer stability. Recently, it has been shown that the sponge Tethya aurantia, a member of the most ancient group of living multi-cellular animals, expresses an obligate, dimeric MtCK that lacks this absolutely conserved tryptophan residue, instead possessing a tyrosine in this position. In the present study we confirm that the absolutely conserved tryptophan residue is lacking in other sponge MtCKs where it is instead substituted by histidine or asparagine. Site directed mutations of the Trp-264 in expression constructs of chicken sarcomeric MtCK and the octameric MtCK from the marine worm Chaetopterus destabilized the octameric quaternary structure producing only dimers. A Tyr→Trp mutation in an expression construct of the Tethya MtCK construct failed to produce octamerization; Tyr→His and Tyr→Asn mutations also yielded dimers. These results, in conjunction with analysis of homology models of Chaetopterus and Tethya MtCKs, strongly support the view that while the absolutely conserved tryptophan residue is important in octamer stability, octamer formation involves a complex suite of interactions between a variety of residues. [Copyright &y& Elsevier]

Recently, geopolymer (GP) cements have proven adequate to immobilize oil emulsions as GEOIL composites. When used for radioactive waste storage, the vicinity of GEOIL with Portland Cement (PC) concretes may induce leaching by the PC pore water. This research identifies the preferential water flow pathways, and quantifies the water permeability of hardened GEOIL mortars using a typical PC pore water. Two alkali-activated GP cements are used, either made of 100% metakaolin (MK) or of 80%MK-20% slag, for oil proportions of 0, 20, 40 or 60%vol. For the identification of the preferential water flow pathways, two water flow scenarii are investigated numerically. Either water flows through the oil emulsion (Scenario 1) or water flows through the GP cement mortar pores (Scenario 2). The 3D structure of the oil emulsion is quantified by X Ray micro-computed tomography (X Ray micro-CT), and the pore structure of GP cement mortars is identified by image analysis. Fluid pathways are predicted for both scenarii by 3D numerical simulations. Secondly, water permeability experiments are conducted on GEOIL mortars. Water permeability K water of highly alkaline PC water is deduced over several weeks. The results validate Scenario 2; for 20 or 40%vol oil, water flows preferentially through the GP cement mortar pores (at a permeability below 10−18 m2), instead of through the percolating oil emulsion. Finally, experiments show that K water for the GP cement mortar made of 80%MK-20%GGBFS does not remain stable over time when added with 20%vol oil. Comparatively, for the 100%MK GP cement mortar with 20%vol oil, a stable K water is recorded for 40 days. Whatever the oil percentage, the initial K water value is identical and smaller than without oil. A dedicated experiment shows that the oil additives (surfactants) are very probably responsible for this behaviour. At 60%vol oil, water and organic matter flow progressively out of the GEOIL composite. [ABSTRACT FROM AUTHOR]