Cobalt silicide formation on a Si(1 0 0) substrate in the presence of an interfacial (Fe90Zr10) interlayer

The reaction between a thin film (126 nm) of Co and Si has been studied at 450 C for 24 h under high vacuum conditions, in the presence of a FeZr barrier layer. Without a diffusion barrier layer between Co and Si, Co2Si forms at 350 C as the initial phase while CoSi2 forms at 550 C. The FeZr barrier layer changed the flux of atoms arriving at the reaction interface. Co reacted with the Si from the substrate and formed a mixed layer of CoSi and CoSi2 in the interlayer region. The use of the FeZr diffusion barrier has been demonstrated to lower the temperature formation of CoSi2 to 450 C. The reactions were characterised by Rutherford backscattering spectrometry, Auger electron spectroscopy depth profiling, X-ray diffraction using CoKa radiation and scanning electron microscopy.http://www.elsevier.com/locate/nimb2016-09-30hb201

Scanning electron microscopy of the surfaces of ion implanted SiC

This paper gives a brief review of radiation damage caused by particle (ions and neutrons) bombardment in SiC at different temperatures, and its annealing, with an expanded discussion on the effects occurring on the surface. The surface effects were observed using SEM (scanning electron microscopy) with an inlens detector and EBSD (electron backscatter diffraction). Two substrates were used, viz. single crystalline 6H-SiC wafers and polycrystalline SiC, where the majority of the crystallites were 3C-SiC. The surface modification of the SiC samples by 360 keV ion bombardment was studied at temperatures below (i.e. room temperature), just at (i.e. 350 C), or above (i.e. 600 C) the critical temperature for amorphization of SiC. For bombardment at a temperature at about the critical temperature an extra step, viz. postbombardment annealing, was needed to ascertain the microstructure of bombarded layer. Another aspect investigated was the effect of annealing of samples with an ion bombardment-induced amorphous layer on a 6H-SiC substrate. SEM could detect that this layer started to crystalize at 900 C. The resulting topography exhibited a dependence on the ion species. EBSD showed that the crystallites forming in the amorphized layer were 3C-SiC and not 6H-SiC as the substrate. The investigations also pointed out the behaviour of the epitaxial regrowth of the amorphous layer from the 6H-SiC interface.http://www.elsevier.com/locate/nimb2016-07-31hb201

Antioxidant therapeutic advances in COPD

Chronic obstructive pulmonary disease (COPD) is associated with a high incidence of morbidity and mortality. Cigarette smoke-induced oxidative stress is intimately associated with the progression and exacerbation of COPD and therefore targeting oxidative stress with antioxidants or boosting the endogenous levels of antioxidants is likely to have beneficial outcome in the treatment of COPD. Among the various antioxidants tried so far, thiol antioxidants and mucolytic agents, such as glutathione, N-acetyl-L-cysteine, N-acystelyn, erdosteine, fudosteine and carbocysteine; Nrf2 activators; and dietary polyphenols (curcumin, resveratrol, and green tea catechins/quercetin) have been reported to increase intracellular thiol status along with induction of GSH biosynthesis. Such an elevation in the thiol status in turn leads to detoxification of free radicals and oxidants as well as inhibition of ongoing inflammatory responses. In addition, specific spin traps, such as α-phenyl-N-tert-butyl nitrone, a catalytic antioxidant (ECSOD mimetic), porphyrins (AEOL 10150 and AEOL 10113), and a SOD mimetic M40419 have also been reported to inhibit cigarette smoke-induced inflammatory responses in vivo in the lung. Since a variety of oxidants, free radicals and aldehydes are implicated in the pathogenesis of COPD, it is possible that therapeutic administration of multiple antioxidants and mucolytics will be effective in management of COPD. However, a successful outcome will critically depend upon the choice of antioxidant therapy for a particular clinical phenotype of COPD, whose pathophysiology should be first properly understood. This article will review the various approaches adopted to enhance lung antioxidant levels, antioxidant therapeutic advances and recent past clinical trials of antioxidant compounds in COPD

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

The effect of the colonisation extent of arbuscular mycorrhizal fungi on the growth of pot grown Pterocarpus angolensis seedlings

The effect of the level of arbuscular mycorrhizal fungi (AMF) colonisation on the growth of Pterocarpus angolensis was studied. Mycorrhizal infected seedlings, showing either good or poor growth, under the same environmental conditions (temperature, humidity, light level) were analyzed for above and below ground biomass and N and P concentration. The grouping was based on the number of leaves and seedling size. All plants had AMF infection, with poor growth plants having a 75% infection and good growth plants 45%. The highly infected poor growth plants had fewer leaves, smaller total leaf area and total plant mass. The below ground plant component N and P concentration of good growth plants was higher than in poor growth plants. There was however no difference in N and P concentrations of above ground components between the two groups. No nodules were recorded for good growth plants while plants in the poor growth group had nodules. There was no difference in the specific leaf mass and shoot:root ratio of the two groups, although the leaf area ratio was higher in good growth plants. The high AMF infection had a negative effect on the growth and development of plants. This study highlighted the presence of AMF in nursery grown Pterocarpus angolensis and the host benefits from various colonisation levels. A long-term field trial is needed to study the effects of different AMF colonization levels on tree vigour under different environmental conditions.Articl

Characterization of the interactions of the pneumolysoid, Δ6 PLY, with human neutrophils <i>in vitro</i>

The pneumolysin toxoid, Δ6 PLY, is a prototype pneumococcal protein vaccine candidate. However, its potentially detrimental residual pro-inflammatory interactions with human neutrophils are unknown. In the current study the effects of the toxoid (8–1000 ng/ml) have been compared with those of wild-type pneumolysin (WT/PLY, 8 ng/ml) on neutrophil cytosolic Ca&lt;sup&gt;2+&lt;/sup&gt; fluxes, generation of leukotriene B&lt;sub&gt;4&lt;/sub&gt; (LTB&lt;sub&gt;4&lt;/sub&gt;), and release of matrix metalloproteinase-9 (MMP-9), using spectrofluorimetric, and ELISA procedures (LTB&lt;sub&gt;4&lt;/sub&gt; and MMP-9) respectively. Exposure of neutrophils to WT/PLY resulted in influx of Ca&lt;sup&gt;2+&lt;/sup&gt; and significant (P &#60; 0.05) release of MMP-9 and generation of LTB&lt;sub&gt;4&lt;/sub&gt;. However, treatment of the cells with Δ6 PLY at concentrations of up to 1000 ng/ml had only trivial effects on Ca&lt;sup&gt;2+&lt;/sup&gt; influx and no effects on either release of MMP-9 or LTB&lt;sub&gt;4&lt;/sub&gt; production. The observed absence of pro-inflammatory interactions of Δ6 PLY with neutrophils is clearly an important property of this pneumococcal protein vaccine candidate

Health effects of passive smoking in adolescent children

No Abstract