Si and Sn doping of ε-Ga2O3 layers

Low resistivity n-type e-Ga2O3 epilayers were obtained for the first time either by adding silane to the gas phase during the metal organic vapour phase epitaxy deposition or by diffusing Sn in nominally undoped layers after the growth. The highest doping concentrations were few 1018 cm−3 and about 1017 cm−3 for Si and Sn doping, with corresponding resistivity below 1 and 10 Ω cm, respectively. Temperature dependent transport investigation in the range of 10-600 K shows a resistivity behavior consistent with the Mott law, suggesting that conduction through localized states dominates the electrical properties of Si- and Sn-doped samples. For both types of dopants, two different mechanisms of conduction through impurity band states seem to be present, each of them determining the transport behavior at the lower and higher temperatures of the measurement range.Low resistivity n-type e-Ga2O3 epilayers were obtained for the first time either by adding silane to the gas phase during the metal organic vapour phase epitaxy deposition or by diffusing Sn in nominally undoped layers after the growth. The highest doping concentrations were few 1018 cm−3 and about 1017 cm−3 for Si and Sn doping, with corresponding resistivity below 1 and 10 Ω cm, respectively. Temperature dependent transport investigation in the range of 10-600 K shows a resistivity behavior consistent with the Mott law, suggesting that conduction through localized states dominates the electrical properties of Si- and Sn-doped samples. For both types of dopants, two different mechanisms of conduction through impurity band states seem to be present, each of them determining the transport behavior at the lower and higher temperatures of the measurement range

Identification of genomic regions associated with total and progressive sperm motility in Italian Holstein bulls

Sperm motility is directly related to the ability of sperm to move through the female reproductive tract to reach the ovum. Sperm motility is a complex trait that is influenced by environmental and genetic factors and is associated with male fertility, oocyte penetration rate, and reproductive success of cattle. In this study we carried out a GWAS in Italian Holstein bulls to identify candidate regions and genes associated with variations in progressive and total motility (PM and TM, respectively). After quality control, the final data set consisted of 5,960 records from 949 bulls having semen collected in 10 artificial insemination stations and genotyped at 412,737 SNPs (call rate >95%; minor allele frequency >5%). (Co)variance components were estimated using single trait mixed models, and associations between SNPs and phenotypes were assessed using a genomic BLUP approach. Ten windows that explained the greatest percentage of genetic variance were located on Bos taurus autosomes 1, 2, 4, 6, 7, 23, and 26 for TM and Bos taurus autosomes 1, 2, 4, 6, 8, 16, 23, and 26 for PM. A total of 150 genes for TM and 72 genes for PM were identified within these genomic regions. Gene Ontology enrichment analyses identified significant Gene Ontology terms involved with energy homeostasis, membrane functions, sperm-egg interactions, protection against oxidative stress, olfactory receptors, and immune system. There was significant enrichment of quantitative trait loci for fertility, calving ease, immune response, feed intake, and carcass weight within the candidate windows. These results contribute to understanding the architecture of the genetic control of sperm motility and may aid in the development of strategies to identify subfertile bulls and improve reproductive success

Effects of olive oil and its minor phenolic constituents on obesity-induced cardiac metabolic changes

<p>Abstract</p> <p>Background</p> <p>Olive oil and its minor constituents have been recommended as important dietary therapeutic interventions in preventive medicine. However, a question remains to be addressed: what are the effects of olive oil and its phenolic compounds on obesity-induced cardiac metabolic changes?</p> <p>Methods</p> <p>Male Wistar rats were divided into two groups (<it>n </it>= 24/group): (C) receiving standard-chow; (Ob) receiving hypercaloric-chow. After 21 days C and Ob groups were divided into four subgroups (<it>n </it>= 6/group):(C) standard-chow and saline; (C-Olive)standard-chow and olive-oil (3.0 g/kg.day); (C-Oleuropein)standard-chow and oleuropein (0.023 mg/kg/day); (C-Cafeic) standard-chow and cafeic-acid (2.66 mg/kg/day); (Ob)receiving hypercaloric-chow and saline;(Ob-Olive) hypercaloric-chow and olive-oil;(Ob-Oleuropein) hypercaloric-chow and oleuropein;(Ob-Cafeic) hypercaloric-chow and cafeic-acid. Treatments were given twice a week during 21 days.</p> <p>Results</p> <p>After 42 days, obesity was evidenced in Ob rats from enhanced body-weight, surface-area, and body-mass-index. Energy-expenditure, oxygen consumption(VO₂) and fat-oxidation were lower in Ob-group than in C. Despite no morphometric changes, Ob-Olive, Ob-Oleuropein and Ob-Cafeic groups had higher VO₂, fat-oxidation, myocardial beta-hydroxyacyl coenzyme-A dehydrogenase and lower respiratory-quotient than Ob. Citrate-synthase was highest in Ob-Olive group. Myocardial lipid-hydroperoxide(LH) and antioxidant enzymes were unaffected by olive-oil and its compounds in obesity condition, whereas LH was lower and total-antioxidant-substances were higher in C-Olive and C-Oleuropein than in C.</p> <p>Conclusions</p> <p>The present study demonstrated for the first time that olive-oil, oleuropein and cafeic-acid enhanced fat-oxidation and optimized cardiac energy metabolism in obesity conditions. Olive oil and its phenolic compounds improved myocardial oxidative stress in standard-fed conditions.</p

Enrofloxacin resistance in Escherichia coli isolated from poultry: preliminary analysis of gyrA and parC sequences

Escherichia coli are usually common inhabitants of the gastrointestinal tract of birds, although avian pathogenic strains can cause several diseases. Furthermore, gut of birds can be a reservoir of zoonotic E. coli, and contamination of poultry products may occur during slaughtering and processing procedures. Enrofloxacin (ENR) is commonly used in poultry farming, although recently a prudent and rationale use of fluoroquinolone (FQ) in farm animals is recommended by the European Union. The most frequent mechanism of FQ resistance in E. coli is represented by alterations occurring in genes encoding for DNA gyrase and topoisomerase IV. The aims of this study were to evaluate the ENR resistance in E. coli isolated from poultry and to investigate mutations in the sequences of gyrA and parC genes. Swab samples collected from poultry were tested by bacteriology. Pure cultures of E. coli were used for MIC and for DNA extraction. DNA was amplified by PCR to obtain a 347 bp fragment of gyrA gene and a 964 bp fragment of parC gene. PCR products were sequenced and analysed. A total of 12 E. coli isolates resulted resistant to ENR by MIC. Further 12 ENR-susceptible E. coli were randomly selected among all susceptible isolates. Predicted amino acid sequences of gyrA and parC were aligned and analyzed blindly. Most of resistant E. coli isolates showed mutations at codons 83 and 87 of gyrA and at codon 80 of parC. In particular, 11 resistant isolates had Ser83Leu mutation, that was present also in 3 susceptible isolates. No other mutations at codons 83 and 87 of gyrA and at codon 80 of parC were found in susceptible isolates. Among resistant isolates, 10 possessed mutations at gyrA codon 87 and 11 isolates showed mutations at parC codon 80. Mutations were Asp87Asn (n=8), Asp87Gly (n=1), Asp87Tyr (n=1) in gyrA and Ser80Ile (n=9) and Ser80Arg (n=2) in parC. Evaluation of mutations at codon 80 of parC resulted the most sensitive (91.7%) and specific (100%) test for distinguishing ENR-susceptible to ENR-resistant isolates. Finally, 7 out of 12 ENR-resistant isolates showed two gyrA mutations (Ser83Leu and Asp87Asn) coupled with a substitution in parC (Ser80Ile); the same findings have been reported in E. coli isolated from poultry and resulted resistant to many FQs (ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, flumequine, marbofloxacin, nalidixic acid, and sarafloxacin). These isolates showed also the highest values of MIC