MOCVD growth of Bi2Te3-Sb2Te3 layers : Effect of growth parameters on the electrical and thermoelectrical properties

The growth of (Bi1-xSbx)2Te3 thin films by metal-organic chemical vapour deposition (MOCVD) using trimethylbismuth, triethylantimony and diethyltellurium as bismuth, antimony and tellurium sources respectively is investigated on pyrex substrates. The electrical and thermoelectrical properties of this material are also measured over the growth temperature range 360-470°C. The studies are also made on the effect of VI/V ratio on these properties in the variation range 2-9. Polycrystalline structure is confirmed by X-ray diffraction, and it is observed that the intensity of the preferred orientation is higher at 450°C. The measurement of Seebeck coefficient shows that all samples have p-type conduction. The best value of this parameter is obtained for high growth temperature (240µV/K). The good result obtained for (Bi1-xSbx)2Te3 thin films revealed the great potential of MOCVD method which is an industrial technique to produce good materials for device applications (sensors and thermopiles).The growth of (Bi1-xSbx)2Te3 thin films by metal-organic chemical vapour deposition (MOCVD) using trimethylbismuth, triethylantimony and diethyltellurium as bismuth, antimony and tellurium sources respectively is investigated on pyrex substrates. The electrical and thermoelectrical properties of this material are also measured over the growth temperature range 360-470°C. The studies are also made on the effect of VI/V ratio on these properties in the variation range 2-9. Polycrystalline structure is confirmed by X-ray diffraction, and it is observed that the intensity of the preferred orientation is higher at 450°C. The measurement of Seebeck coefficient shows that all samples have p-type conduction. The best value of this parameter is obtained for high growth temperature (240µV/K). The good result obtained for (Bi1-xSbx)2Te3 thin films revealed the great potential of MOCVD method which is an industrial technique to produce good materials for device applications (sensors and thermopiles)

Recurrent Pericarditis in Children and Adolescents

Recurrent pericarditis (RP) is a clinical syndrome characterized by recurrent attacks of acute pericardial inflammation. Prognosis quoad vitam is good, although morbidity might be significant, especially in children and adolescents. Multiple potential etiologies result in RP, in the vast majority of cases through autoimmune or autoinflammatory mechanisms. Idiopathic RP is one of the most frequent diagnoses, that requires the exclusion of all known etiologies. Therapeutic advances in the last decade have been significant with the recognition of the effectiveness of anti IL1 therapy, but a correct diagnostic and therapeutic algorithm is of key importance. Unfortunately, most of evidence comes from studies in adult patients. Here we review the etiopathogenesis, diagnosis and management of RP in pediatric patients

Exergy and exergy cost analysis of biochemical networks in living systems far from equilibrium

Whilst, humanity has reached a high level of technological development, finding efficient substitutes to petroleum energy is a challenging task. Metabolically engineered microorganisms are used in biomass production. Considering the availability of data in genomic and metabolic fronts, Escherichia coli is one of the primary options for biofuel production, which could be later exploited as a ‘solo’ energy source, or coupled with nowadays available fuels. To survive, an organism must provide an amount of exergy greater than the exergy required to process equilibrium operations. Therefore, extra exergy amounts are needed for a living system to accomplish production, growth and evolution in time, as the above mentioned process is highly irreversible. This paper reviews the available studies on exergy analysis and exergy-cost theory application, along with the use of flux balance analysis-FBA and FVA, as a tool for gaining biological insights. This paper is structured as the following; first, a brief description of exergy analysis and the exergy-cost theory is presented. Second, the exergy analysis application on living cells is discussed through introducing exergy analysis of metabolic network. Thirdly, the application on Escherichia Coli is explained, highlighting its potential role in biofuel production. Finally, an approach, applied within a current PhD research project regarding the application of the exergy analysis to a generic metabolic network is introduced. In this approach, the exergy costs associated with all the flows present in the targeted network are calculated, according to the ECT. The perspective is to use the exergy cost information for defining additional constraints in the FBA of the metabolic network. Which could provide better insight about organisms and identify directions for the optimization of biomass production, and the enhancement of biofuel use

The Importance of Nutrition in Hypertension

Arterial hypertension (AH) is considered to be one of the most relevant cardiovascular risk factors, and its wide prevalence in all age ranges makes it necessary to analyse all the possible causes and treatments. In this special issue, nutritional interventions are examined either as causes or as treatments of AH. [...]

Clinical and Pathophysiological Insights Into Immunological Mediated Glomerular Diseases in Childhood

The kidney is often the target of immune system dysregulation in the context of primary or systemic disease. In particular, the glomerulus represents the anatomical entity most frequently involved, generally as the expression of inflammatory cell invasion or circulant or in situ immune-complex deposition. Glomerulonephritis is the most common clinical and pathological manifestation of this involvement. There are no universally accepted classifications for glomerulonephritis. However, recent advances in our understanding of the pathophysiological mechanisms suggest the assessment of immunological features, biomarkers, and genetic analysis. At the same time, more accurate and targeted therapies have been developed. Data on pediatric glomerulonephritis are scarce and often derived from adult studies. In this review, we update the current understanding of the etiologic events and genetic factors involved in the pathogenesis of pediatric immunologically mediated primitive forms of glomerulonephritis, together with the clinical spectrum and prognosis. Possible new therapeutic targets are also briefly discussed

Endothelial Hyper-Permeability Induced by T1D Sera Can be Reversed by iNOS Inactivation

Type 1 Diabetes Mellitus (T1D) is associated with accelerated atherosclerosis that is responsible for high morbidity and mortality. Endothelial hyperpermeability, a feature of endothelial dysfunction, is an early step of atherogenesis since it favours intimal lipid uptake. Therefore, we tested endothelial leakage by loading the sera from T1D patients onto cultured human endothelial cells and found it increased by hyperglycaemic sera. These results were phenocopied in endothelial cells cultured in a medium containing high concentrations of glucose, which activates inducible nitric oxide synthase with a consequent increase of nitric oxide. Inhibition of the enzyme prevented high glucose-induced hyperpermeability, thus pointing to nitric oxide as the mediator involved in altering the endothelial barrier function. Since nitric oxide is much higher in sera from hyperglycaemic than normoglycaemic T1D patients, and the inhibition of inducible nitric oxide synthase prevents sera-dependent increased endothelial permeability, this enzyme might represent a promising biochemical marker to be monitored in T1D patients to predict alterations of the vascular wall, eventually promoting intimal lipid accumulation

The source and the age of the soil organic matter of Anthrosols in SW Norway

Recent investigations showed that humus‑rich topsoil’s around the Baltic Sea have been formed by the application of pyrogenic organic matter (Acksel et al., 2016, Geoderma Reg. 7, 187–200) and organic materials (e.g. animal manure, organic waste) linked with human activity and, consequently, these soils were classified as Anthrosols (Acksel et al., 2017 (submitted)). Such humus‑rich topsoil’s, which were strongly influenced by anthropogenic activities and classified as plaggic Anthrosols, were described in SW Norway (Schnepel et al., 2014, J. Plant Nutr. Soil Sci., 177 (4), 638–645.). However, the source and the formation time of the Anthrosols in Norway have not been investigated in detail. Therefore, we characterized the soil organic matter composition by pyrolysis-field ionisation-mass spectrometry (Py-FIMS), benzene polycarboxylic acids (BPCA) determination, examined the source of the SOM by isotopic signatures (d34S) and estimated the age of the SOM by 14C AMS dating in order to find out the beginning of Anthrosol formation. Py-FIMS revealed high portions of sterols and fatty acids, indicating inputs of manure, similar to plaggic Anthrosols in NW Germany. The BC portions (≈ 19 % BC of Corg) were similar to various Anthrosols (≈ 25 % BC of Corg) and Chernozems (≈ 13 % BC of Corg) worldwide and indicated an input of combustion residues to soils by early fire events. The d34S isotope signature of the SOM ranged from 10 to 13.4 ‰ at the islands and 10.6 to 15.2 in the Jaeren region of SW Norway, corresponded to the Anthrosols in the Baltic Sea region (Median: d34S = 11.5 ‰) and indicated an input of marine biomass (d34S of seaweed = 20 ‰). All these results complemented the study of Schnepel et al. (2014) and provided strong evidence that these soils were formed by human activities. Ongoing analyses of 14C ages from these soils enable to estimate the timing of the soil formation and link it to settlement history