Stored energy in ultrafine-grained 316L stainless steel processed by high-pressure torsion

The energy stored in severely deformed ultrafine-grained (UFG) 316L stainless steel was investigated by differential scanning calorimetry (DSC). A sample was processed by high-pressure torsion (HPT) for N = 10 turns. In the DSC thermogram, two peaks were observed. The first peak was exothermic and related to the annihilation of vacancies and dislocations. During this recovery, the phase composition and the average grain size were practically unchanged. The energy stored in dislocations was calculated and compared with the heat released in the exothermic DSC peak. The difference was related to the annihilation of vacancy-like defects with a concentration of â¼5.2 Ã 10â4. The second DSC peak was endothermic which was caused by a reversion of αâ²-martensite into γ-austenite, however in this temperature range dislocation annihilation and a moderate grain growth also occurred. The specific energy of the reverse martensitic phase transformation was determined as about â11.7 J/g. Keywords: High-pressure torsion, Stored energy, Stainless steel, Phase transformation, Thermal stabilit

An evaluation of biosecurity compliance levels and assessment of associated risk factors for highly pathogenic avian influenza H5N1 infection of live-bird-markets, Nigeria and Egypt

Live bird market (LBM) is integral component in the perpetuation of HPAI H5N1, while biosecurity is crucial and key to the prevention and control of infectious diseases. Biosecurity compliance level and risk factor assessments in 155LBMs was evaluated in Nigeria and Egypt through the administration of a 68-item biosecurity checklist, scored based on the modifications of previous qualitative data, and analysed for degree of compliance. LBMs were scored as "complied with a biosecurity item" if they had good-very good scores (4). All scores were coded and analysed using descriptive statistics and risk or protective factors were determined using univariable and multivariable logistic regression at p≤0.05. Trading of wild birds and other animal in the LBMs (Odd Ratio (OR)=34.90; p=0.01) and claims of hand disinfection after slaughter (OR=31.16; p=0.03) were significant risk factors while mandatory routine disinfection of markets (OR=0.13; p≤0.00), fencing and gates for live bird market (OR=0.02; p≤0.01) and hand washing after slaughter (OR=0.41; p≤0.05) were protective factors for and against the infection of Nigerian and Egyptian LBMs with the HPAI H5N1 virus. Almost all the LBMs complied poorly with most of the variables in the checklist (p≤0.05), but pathways to improved biosecurity in the LBMs existed. We concluded that the LBM operators play a critical role in the disruption of transmission of H5N1 virus infection through improved biosecurity and participatory epidemiology and multidisciplinary approach is needed.http://www.elsevier.com/locate/actatropica2017-12-31hb2017Veterinary Tropical Disease

Diabetic foot infections: a team-oriented review of medical and surgical management

As the domestic and international incidence of diabetes and metabolic syndrome continues to rise, health care providers need to continue improving management of the long-term complications of the disease. Emergency department visits and hospital admissions for diabetic foot infections are increasingly commonplace, and a like-minded multidisciplinary team approach is needed to optimize patient care. Early recognition of severe infections, medical stabilization, appropriate antibiotic selection, early surgical intervention, and strategic plans for delayed reconstruction are crucial components of managing diabetic foot infections. The authors review initial medical and surgical management and staged surgical reconstruction of diabetic foot infections in the inpatient setting

Synthesis, physicochemical and vibrational spectral properties of 2–pyridone and 2–aminopyridine derivatives: An experimental and theoretical study

A convenient and efficient one–pot three–component reaction of acetyl acetone, malononitrile and ammonium acetate was investigated for the synthesis of 3–cyano–4,6–dimethyl–2–pyridone (PI) and 2–amino–3–cyano–4,6–dimethylpyridine (PII). The products were achieved with high purity, high yields and short reaction time. The yields of the two products depend on the concentration of ammonium acetate, reaction time and the solvent used. The structures of the isolated products were confirmed by elemental analysis and spectral data, supported by quantum chemical (MP2) calculations, both in gas phase and solvents (water and ethanol), that were also employed to track the reaction mechanisms and model vibrational spectral properties for final characterization and interpretation of spectral data. A remarkable matching between theoretical predictions and experiments was attained both for the geometrical parameters, as compared to X-Ray data available in the literature, and for vibrational frequencies, leading to a correlation coefficient (R2) of 0.99. Molecular docking was further studied to predict the docking binding energy of the synthesized compounds with the target proteins

Bispropylurea bridged polysilsesquioxane: A microporous MOF-like material for molecular recognition

Microporous organosilicas assembled from polysilsesquioxane (POSS) building blocks are promising materials that are yet to be explored in-depth. Here, we investigate the processing and molecular structure of bispropylurea bridged POSS (POSS-urea), synthesised through the acidic condensation of 1,3-bis(3-(triethoxysilyl)propyl)urea (BTPU). Experimentally, we show that POSS-urea has excellent functionality for molecular recognition toward acetonitrile with an adsorption level of 74 mmol/g, which compares favourably to MOFs and zeolites, with applications in volatile organic compounds (VOC). The acetonitrile adsorption capacity was 132-fold higher relative to adsorption capacity for toluene, which shows the pores are highly selective towards acetonitrile adsorption due to their size and arrangement. Theoretically, our tight-binding density functional and molecular dynamics calculations demonstrated that this BTPU based POSS is microporous with an irregular placement of the pores. Structural studies confirm maximal pore sizes of ∼1 nm, with POSS cages possessing an approximate edge length of ∼3.16 Å