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We present a simple method for identification of seasonal components in GPS displacement time series. The method considers two options for the treatment of long series, considering possible variability in the seasonal phases. The method also proposes a bootstrap scheme to deal approximately with series shorter than one period of the seasonal signal. Tests with synthetic data show that the method gives quite acceptable results, so that results from application to real data, although approximate, should be useful considering the inherent uncertainties in the data. [ABSTRACT FROM AUTHOR]

The document titled "Correction to: Seasonal components in GPS displacement time series" in Acta Geophysica addresses mistakes in the original publication, specifically in the acknowledgment section. The corrected version acknowledges support from various organizations and individuals, including CONAHCYT, Servicio de Geodesia Satelital, and UNAM. The document expresses gratitude to all personnel and collaborators involved in station installation, maintenance, data acquisition, and support for GPS-related operations. The correction was reported by F. Alejandro Nava and Lenin Ávila-Barrientos. [Extracted from the article]

The concept of Poisson renormalized entropy is presented as an observable of background seismicity with precursory possibilities. The usual way of estimating entropies evaluating probabilities directly from the normalized number of incidences is shown to be lacking in sensitivity and seriously subject to saturation. As an example, the concept of Poisson renormalized entropy and the associated method are applied to the seismicity previous to the 2011 Tohoku MW = 9.1 megaearthquake, and shown to be able to identify precursory changes in the seismicity. Results are compared with those from fractal dimension and Gutenberg-Richter b-value studies. [ABSTRACT FROM AUTHOR]

Purpose: The advantages offered by structured reporting have already been highlighted in the literature. However, there is still no evidence on the validity of this reporting method for the study of abdominal wall defects. This study aims to show the experience of the Trentino Hernia Team (THT) multidisciplinary group in the development and use of a structured CT scan report for the study of abdominal wall defects. Methods: A regional multidisciplinary team (THT group) used a Delphi method to identify and select the most important CT scan parameters needed to describe and stage abdominal wall defects for correct preoperative planning. Based on the selected parameters, a CT scan structured report was worked out and collectively accepted. The first 20 structured reports obtained were individually tested for compilation speed and homogeneity of the data reported by five distinct radiologists. The reports were then evaluated by five different surgeons to test the simplicity of interpretation. Results: We produced a model of a structured report for the study of the abdominal wall defects and tested it in our hospital network on the first 20 reports. The average completion time was 18 min (range 12–25). There was no heterogeneity among the reported data. The reports were analysed by five distinct surgeons to evaluate completeness and simplicity of interpretation. Each surgeon used a Likert scale from 0 to 5 to evaluate each report, producing average scores of 4.8 and 4.1 for completeness and comprehensibility respectively, with a mean combined total score of 8.9 out of 10. Conclusions: Our structured report represents a fundamental tool capable of providing the surgeon with all the measurements of the parameters necessary for correct preoperative planning. At the same time, it is of crucial help for the radiologists representing an easy and fast way to report all the needed parameters using the same standards. [ABSTRACT FROM AUTHOR]

Seismic clusters in background seismicity have been associated with high stress levels and can be an important precursor to large earthquakes, but there is not a unanimous concept of cluster and most cluster identification methods are cumbersome and involve a priori assumptions. We propose a simple definition of seismic cluster and a straightforward method of identification involving a minimum of parameters that can be objectively determined in a data-driven way according to a principle of low random occurrence. As an illustration, definition and method were applied to the identification of cluster activity from October 1979 to March 2010 in northern Baja California, Mexico, between 118°W to 113°W and 30°N to 33°N, a tectonically complex seismic region with several fault systems. Twenty-one clusters were identified, of which 17 located around the places at the northeastern corner of the study area that would be ruptured on April 4, 2010 by the El Mayor-Cucapah M w 7.1 earthquake, the largest recorded earthquake in Baja California, Mexico, and the four others occurred within 9 km from its epicenter. Clustering also became slightly more frequent as the time of the earthquake approached, so that if the clustering survey had been carried out before the whole northern Baja California area, the clustering might have identified the future epicentral region as a region of interest to be closely monitored (this earthquake featured foreshock activity starting some 15 days before the main event). Although the reliability of clusters as precursors to large earthquakes is still to be studied, it is certainly useful to have a reliable and simple method to identify and characterize them. [Display omitted] • A simple method for identification of seismicity clusters is presented. • 21 clusters were identified within a small region of the study area in NW Mexico. • The clusters become more frequent and more energetic before a M 7.2 earthquake. • 17 clusters located close to the rupture of the earthquake. [ABSTRACT FROM AUTHOR]

Introduction. Multifocal lymphangioendotheliomatosis with thrombocytopenia (MLT) is characterized by multiple maculopapular lesions involving the stomach and the lungs, associated with thrombocytopenia as a result of platelet entrapment. Episodes of severe digestive bleeding, which are sometimes unmanageable, are one of its most frequent presentations and a cause of mortality. Our objective was to describe the various phenotypes, as well as our treatment experience. Materials and methods. A retrospective analysis of patients diagnosed with MLT in our vascular abnormality unit from 2007 to 2018 was carried out. Epidemiological, clinical, and evolution data were analyzed, and a long-term follow-up was performed. Results. Five patients (3 boys and 2 girls) had congenital macules and erythematous papules of various sizes. They were later associated with episodes of severe hematemesis along with thrombocytopenia, which required blood product transfusion. The most frequently involved areas were the stomach and the colon. In two patients, multiple bilateral pulmonary nodules were noted. The anatomical pathology examination showed extended vessels with a prominent, hobnail endothelium, as well as intraluminal papillary projections in the dermis. Immunohistochemical analysis was CD-31 positive and CD-34 positive in a characteristic manner. Two patients were treated with mTOR inhibitors (rapamycin), with a progressive decrease in extracutaneous involvement and platelet recovery, but with a poor response in dermal lesions. Two patients were treated with vincristine, with a reduction of digestive bleeding episodes. No deaths were reported in our series. Conclusion. MLT is characterized by hematological and cutaneous involvement - sometimes minimal -, with potential lesions in other internal organs. Its heterogeneous presentation, which may start with severe digestive bleeding, makes this rare pathology difficult to diagnose. mTOR inhibitors have opened up new treatment possibilities. [ABSTRACT FROM AUTHOR]

Objective: Our aim was to evaluate the relationship between evening chronotype, a proxy marker of circadian system dysfunction, and disordered eating behavior and poor dietary habits in individuals with bipolar disorder (BD). Methods: In this cross‐sectional study, we evaluated 783 adults with BD. Chronotype was determined using item 5 from the reduced Morningness‐Eveningness Questionnaire. The Eating Disorder Diagnostic Scale (EDDS) and the Rapid Eating Assessment for Participants—Shortened Version (REAP‐S) were used to assess disordered eating behavior and dietary habits respectively. General linear models and logistic regression models were utilized to evaluate differences between chronotype groups. Results: Two hundred and eight (27%) BD participants self‐identified as having evening chronotypes. Compared to non‐evening types, evening types were younger (P < 0.01) and, after controlling for age, had higher mean EDDS composite z‐scores (P < 0.01); higher rates of binge‐eating (BE) behavior (P = 0.04), bulimia nervosa (P < 0.01), and nocturnal eating binges (P < 0.01); and a higher body mass index (P = 0.04). Compared to non‐evening types, evening chronotypes had a lower REAP‐S overall score (P < 0.01) and scored lower on the 'healthy foods' and 'avoidance of unhealthy food' factors. Evening types also skipped breakfast more often (P < 0.01), ate less fruit (P = 0.02) and vegetables (P = 0.04), and consumed more fried foods (P < 0.01), unhealthy snacks (P = 0.02), and soft drinks (P = 0.01). Conclusions: Our findings suggest that the circadian system plays a role in the disordered eating and unhealthy dietary behaviors observed in BD patients. The circadian system may therefore represent a therapeutic target in BD‐associated morbidity that warrants further investigation. [ABSTRACT FROM AUTHOR]

Analysis of energy use efficiency provides an assessment of non-renewable energy consumption; it is a useful indicator of environmental and long-term sustainability when comparing cropping systems. This study aimed to estimate the energy use efficiency of organic and conventional cropping systems of sugarcane for sugar production in central Cuba. Estimation of the energy use efficiency included analysis of four cropping systems. The energy input in the field until harvest and transport to the sugar mill was the limit of this analysis. The results showed that organic cropping systems were less efficient in energy use because of the greater number of field operations, mainly for weed control by manual and mechanical cultivation. Organic cropping systems also had lower yield compared with conventional systems due to their use of low doses of organic products, instead of agrochemical fertilizers, for plant nutrition. In all cropping systems evaluated, sugarcane used for seed was the largest part of the energy input due to the consumption of 12 t ha-1 of seed, representing an average of 89% of the total energy input for the sugarcane cropping systems. The second largest part of the energy input was the fuel consumed during mechanized operations. Irrigation was the third largest part of the energy input for organic cropping systems and the second largest part of the energy input for conventional cropping systems. [ABSTRACT FROM AUTHOR]

Examines the electrical transport properties of five disilicide polycrystalline thin films. Electrical resistivity and Hall-effect measurements of the thin films; Temperature dependence of the resistivity behavior of the five disilicides and their residue resistivities; Discussion of results.

Presents information on a study which investigated the electrical and microstructural changes of coevaporated V[sub75]Si[sub25] alloy thin films, as a function of temperature. Electrical resistivity; Structural and compositional analysis; Kinetics of amorphous to crystalline transformation; Thermal stability of amorphous V[sub3]Si.

Presents a study which examined phase transformations in coevaporated amorphous vanadium-silicon thin alloy films and bilayer vanadium/silicon films. Experiment; Results; Conclusions.

Examines the temperature dependence of semiconducting and structural properties of coevaporated chromium-silicon (Cr-Si) thin alloy films. Kinetics of amorphous-to-crystalline transformation of Cr-Si alloy film; Measurements of the thermoelectric properties of Cr-Si; Conduction mechanism of thin Cr-Si polycrystalline layers.

Studies the electrical transport properties of monocrystalline silicides of high purity and large dimensions in a wide temperature range. Difference in the temperature dependence of the intrinsic resistivities of monocrystallines; Phonon contribution to the resistivity; Resistivity measurements at low and high temperatures.

Observes thermal stability and electrical conduction behavior of coevaporated thin films. Details on the experiment; Discussion of findings; Conclusion.

The Aki-Utsu method of Gutenberg-Richter (G-R) b value estimation is often misapplied so that estimations not using the G-R histogram are often meaningless because they are not based on adequate samples. We propose a method to estimate the likelihood Pr( bǀ b , N, M , M ) that an observed b estimate, based on a sample of N magnitudes within an [ M − ≤ ΔM/2, M + ΔM/2) range, where ΔM = 0.1 is the usual rounding applied to magnitudes, is due to a 'true' source b value, b, and use these likelihoods to estimate source b ranges corresponding to various confidence levels. As an example of application of the method, we estimate the b values before and after the occurrence of a 7.4-magnitude earthquake in the Mexican subduction zone, and find a difference of 0.82 between them with 100% confidence that the b values are different. [ABSTRACT FROM AUTHOR]

Objective: Despite the harmful effects of cigarette smoking, this habit in asthmatic adolescents continues to be a health problem worldwide. Our objectives were to determine the epidemiological profile of smoking and the degree of nicotine dependence among asthmatic adolescents. Study Design: Through a cross-sectional investigation, 3383 adolescents (13-19 years of age) were studied. Methods: Information was collected using a previously validated questionnaire. Two study groups of adolescent smokers were formed: one composed of asthmatic adolescents and the other of healthy youths. Results: Asthmatic adolescents were found to be more likely to smoke (21.6% vs 11.8%) and to have some degree of nicotine dependence compared with healthy adolescents (51.6% vs 48.8%). The most important characteristic of smoking in asthmatic adolescents was found to be an onset before 11 years of age due to curiosity about cigarettes. Asthmatic youths continue smoking because this habit decreases their anxiety and stress. Adolescents know that smoking is addictive and often smoke on waking up in the morning or when they are sick. Yet, these adolescents do not consider smoking to be a problem. Conclusion: In this study, curiosity about cigarettes was the primary reason why asthmatic adolescents smoked for the first time and developed a greater dependence to nicotine compared with healthy adolescents. Moreover, the findings show that many of the factors that favour the development of smoking are preventable, given that they are present in the family and social environment. [ABSTRACT FROM AUTHOR]

The Aki-Utsu maximum likelihood method is widely used for estimation of the Gutenberg-Richter b-value, but not all authors are conscious of the method's limitations and implicit requirements. The Aki/Utsu method requires a representative estimate of the population mean magnitude; a requirement seldom satisfied in b-value studies, particularly in those that use data from small geographic and/or time windows, such as b-mapping and b-vs-time studies. Monte Carlo simulation methods are used to determine how large a sample is necessary to achieve representativity, particularly for rounded magnitudes. The size of a representative sample weakly depends on the actual b-value. It is shown that, for commonly used precisions, small samples give meaningless estimations of b. Our results give estimates on the probabilities of getting correct estimates of b for a given desired precision for samples of different sizes. We submit that all published studies reporting b-value estimations should include information about the size of the samples used. [ABSTRACT FROM AUTHOR]

Background In Human immunodeficiency virus (HIV)-positive patients undergoing kidney transplantation, outcomes and immunosuppression (IS) protocol are not yet established due to infectious and neoplastic risks as well as to pharmacokinetic interactions with antiretroviral therapy (TARV). Methods We report a retrospective, 1-center study on 18 HIV+ patients undergoing, between October 2007 and September 2015, kidney transplantation (13 cases) or combined kidney-liver transplant (5 cases). Inclusion criteria for transplant were based on the Italian National Transplant Center protocol. IS regimen was based on quick tapering of steroids and the use of mTOR inhibitors (mTORi) with low dose of calcineurin inhibitors (CNI). In the early post-transplant period, TARV was based on enfuvirtide, raltegravir, plus 1 or more nucleoside analogues. Results In a mean follow-up of 3.1 years, patient survival rate at 1 and 3 years was, respectively, 86.6% and 84.6%, whereas graft survival was 81.2% and 78.6%. Cumulative rejection rate was 20.0% and 26.6% (1- and 3-year results). Median eGFR (MDRD) was 58.8 mL/min and 51.9 mL/min at 1 and 3 years. We had 9 cases of clinically relevant infections (2 Pneumocystis jirovecii pneumonia, 1 pulmonary aspergillosis, 2 severe sepsis, and 4 HCV reactivation) as well as 1 case (5.5%) of HIV reactivation. Conclusions IS therapy based on mTORi and low CNI dose ensures good graft survival, low rate of acute rejection, limited drug toxicity, and control of HIV disease. TARV has no significant interaction with IS therapy. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: There is converging evidence supporting hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis in schizophrenia spectrum disorders (SSD), such as schizotypal personality disorder (SPD), first-episode schizophrenia (FESZ) and chronic schizophrenia (CHSZ). Such an aberrant HPA activity might have volumetric consequences on the pituitary gland. However, previous magnetic resonance imaging (MRI) studies assessing pituitary volume (PV) in SSD are conflicting. The main objective of this study was to examine further PV in SSD. Methods: PV were manually traced on structural MRIs in 137 subjects, including subjects with SPD (n=40), FESZ (n=15), CHSZ (n=15), and HC (n=67). We used an ANCOVA to test PV between groups and gender while controlling for inter-subject variability in age, years of education, socioeconomic status, and whole brain volume. Results: Overall, women had larger PV than men, and within the male sample all SSD subjects had smaller PV than HC, statistically significant only for the SPD group. In addition, dose of medication, illness duration and age of onset were not associated with PV. Conclusion: Chronic untreated HPA hyperactivity might account for smaller PV in SPD subjects, whereas the absence of PV changes in FESZ and CHSZ patients might be related to the normalizing effects of antipsychotics on PV. SPD studies offer a way to examine HPA related alterations in SSD without the potential confounds of medication effects. [Copyright &y& Elsevier]

Abstract: We propose a method for Fourier spectral analysis of unevenly spaced data which correspond to averages of a given quantity; the method is particularly adapted to data from counting, such as specimen counts from borehole samples. The method is extremely straightforward and takes into account the effects of data averaging. A Monte Carlo approach is used to evaluate possible effects of random errors in time determinations and in counting; probabilities for different possible spectral values are estimated. The method is implemented as a Matlab function. [Copyright &y& Elsevier]

Abstract: The seismic activity from one of the most active (documented) periods of the Colima volcano, from October 1998 to July 1999, was analyzed using the wavelet transform, to study the evolution in time of energy content at different scales of seismic signals preceding eruptive episodes. Time-scale analysis shows seismic energy concentrations at particular scales preceding significant eruptions; concentrations that do not appear within the same time-frame for non-eruptive stages. Quantification of the energy at each scale eases the recognition of characteristic wavelet patterns before the occurrence of significant effusive or explosive eruptions. The recognition of precursory wavelet patterns, which does not depend on the absolute level of energy release, could help to objectively identify precursors to imminent explosive eruptions, even in cases where other seismic energy-based methods are not conclusive. [Copyright &y& Elsevier]

The aim was to determine the effect of feeding and oral habits, toothbrushing, socioeconomic status and allergic rhinitis on the development of dental caries in primary dentition. In a cross-sectional study, data were obtained by means of a structured questionnaire on 1,160 children, 4–5 years old (mean = 4.5 ± 0.5) and born in 1999, 2000 or 2001. The children also had a physical examination by an allergist and dentists. Dental caries was diagnosed according to WHO criteria. Caries experience was measured as number of deft and defs. Logistic regression analysis assessed the association between dental caries and independent variables. The dental caries prevalence was 17.9%, 28.8% of the children had allergic rhinitis symptoms, digit sucking was reported by 9.8% and pacifier use by 13.6% of the children. The mean number of deft of the sample was 1.02 (SD = 2.37) and that of defs was 1.33 (SD = 3.54). Analysis showed that breast-feeding for >12 months (p < 0.01), toothbrushing frequency (p < 0.01), sugar consumption (p < 0.01) and pacifier use (p < 0.01) each had a significant association with dental caries occurrence in primary dentition. Children with pacifier use and allergic rhinitis had more than double the risk of dental caries development. Allergic rhinitis alone has no effect on dental caries. Healthcare professionals attempting to limit dental caries should consider the effect of prolonged breast-feeding, sugary product consumption between meals and nonnutritive habits on dental caries. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Aim: To determine the association between allergic rhinitis, bottle feeding, non-nutritive sucking habits, and malocclusion in the primary dentition. Methods: Data were collected on 1160 children aged 4-5 years, who had been longitudinally followed since the age of 4 months, when they were admitted to nurseries in a suburban area of Tampico-Madero, Mexico. Periodically, physical examinations were conducted and a questionnaire was given to their parents or tutors. Results: Malocclusion was detected in 640 of the children (51.03% had anterior open bite and 7.5% had posterior cross-bite). Allergic rhinitis alone (adjusted odds ratio = 2.87; 95% CI 1.57 to 5.25) or together with non-nutritive sucking habits (adjusted odds ratio = 3.31; 95% Cl 1.55 to 7.09) had an effect on anterior open bite. Bottle feeding alone (adjusted odds ratio = 1.95; 95% Cl 1.07 to 3.54) or together with allergic rhinitis (adjusted odds ratio = 3.96; 95% Cl 1.80 to 8.74) had an effect on posterior cross-bite. Posterior cross-bite was more frequent in children with allergic rhinitis and non-nutritive sucking habits (10.4%). Conclusions: Allergic rhinitis alone or together with non-nutritive sucking habits is related to anterior open bite. Non-nutritive sucking habits together with allergic rhinitis seem to be the most important factor for development of posterior open bite in children under the age of 5 years. [ABSTRACT FROM AUTHOR]

We report the results of an experimental study on the radiation hardness of 4H-SiC diodes used as α-particle detectors with 1 MeV neutrons up to a fluence of 8 × 1015 n/cm². As the irradiation level approaches the range 1015 n/cm², the material behaves as intrinsic due to a very high compensation effect and the diodes are still able to detect with a reasonable good Charge Collection Efficiency (CCE = 80%). For fluences > 1015 n/cm² CCE decreases monotonically to ≈ 20 % at the highest fluence. Heavily irradiated SiC diodes have been studied by means of Photo Induced Current Transient Spectroscopy (PICTS) technique in order to characterize the electronic levels associated with the irradiation-induced defects. The dominant features of the PICTS spectra occur between 400–700 K; in this temperature range the deep levels associated with the induced defects play the main role in degradation of the CCE. Enthalpy, capture cross-section and concentration of such deep levels were calculated and we found that two deep levels (Et = 1.18 eV and Et = 1.50 eV) are responsible for the decrease in CCE. They have been associated to an elementary defect involving a carbon vacancy and to a defect complex involving a carbon and a silicon vacancy, respectively. [ABSTRACT FROM AUTHOR]

Twelve-month treatment of heroin addicts with methadone or buprenorphine normalized plasma cortisol levels, and controlled withdrawal symptoms as well as craving. During treatment, the time course of plasma cortisol levels and craving was not strictly correlated: heroin craving was more elevated at 12 than at 3 months. The results suggest a correlation between hypercortisolism, withdrawal symptoms and heroin use and suppose a more complex role for craving and its components in drug-taking behaviour. The main goal of the pharmacological treatment of opioid-dependence should be addressed at the normalization of hypothalamic-pituitary-adrenocortical (HPA) axis more than at the control of craving. [ABSTRACT FROM AUTHOR]

Particles detectors were made using semiconductor epitaxial 4H-SiC as the detection medium. The investigated detectors are formed by Schottky contact (Au) on the epitaxial layer and an ohmic contact on the backside of 4H-SiC substrates with different micropipe densities from CREE. For radiation hardness studies, the detectors have been irradiated with electrons (8.2 MeV) and γ-rays (60Co source) at fluences and doses ranging from 0 to 9.48×1014 e/cm2 and 40 Mrad, respectively. We present experimental data on the charge collection properties by using 4.14 MeV α-particles impinging on the Schottky contact. Hundred percent Charge Collection Efficiency, CCE, is demonstrated for reverse voltages higher than the one needed to have a depletion region equal to the α-particle projected range, even after the irradiation at the highest dose. By comparing measured CCE values with the outcomes of drift–diffusion simulations, values are inferred for the hole lifetime, τp, within the neutral region of the charge carrier generation layer. τp was found to decrease with increasing radiation levels, ranging from 300 ns in non-irradiated detectors to 3 ns in the most irradiated ones. The diffusion contribution of the minority charge carriers to CCE is pointed out. [Copyright &y& Elsevier]

The development of SiC minimum ionising particle (MIP) detectors imposes severe constrains in the electronic quality and the thickness of the material due to the relatively high value of the energy required to produce an electron–hole pair in this material by MIP against the value for Si. In this work, particle detectors were made using semiconductor epitaxial undoped n-type 4H-SiC as the detection medium. The thickness of the epilayer is on the order of 40 μm and the detectors are realised by the formation of a nickel silicide on the silicon surface of the epitaxial layer (Schottky contact) and of the ohmic contact on the back side of 4H-SiC substrate. The low doping concentration (≅6×1013 cm−3) of the epilayer allows the detector to be totally depleted at relatively low reverse voltages (≅100 V). We present experimental data on the charge collection properties by using 5.486 MeV α-particles impinging on the Schottky contact. A 100% charge collection efficiency (CCE) is demonstrated for reverse voltages higher than the one needed to have a depletion region equal to the α-particle extrapolated range in SiC. The diffusion contribution of the minority change carriers to CCE is pointed out. By comparing measured CCE values to the outcomes of drift–diffusion simulation, values are inferred for the hole lifetime within the neutral region of the charge carrier generation layer. [Copyright &y& Elsevier]

The treatment of effluents of the gold and silver cyanidation process is one of the main problems that the precious metals industry faces. These effluents contain variable quantities of free cyanide, weak complexed cyanide, strong complexed cyanide and thiocyanate. Different methods are used for the removal of cyanide but most of the times the consumption of reagents raises the operation cost to unaffordable levels, and there exists as well the possible formation of residual by-products that are also toxic. Ozone is an alternative gas for oxidation of cyanide compounds that presents several advantages; however the lack of information on the reactions of these compounds with ozone has delayed its industrial application in the treatment of cyanidation effluents. This paper summarizes the research work developed at CINVESTAV between 1996 and 2001 to study the use of ozone to treat cyanidation effluents. Results are presented on the stoichiometry of free cyanide oxidation and copper cyanide complexes. The effects of pH, of temperature and of ozone addition rate on the cyanide oxidation rate are also presented. [ABSTRACT FROM AUTHOR]

Particle detectors were made using semiconductor epitaxial 4H–SiC as the detection medium. The investigated detectors are formed by Schottky contact (Au) on the epitaxial layer and an ohmic contact on the back side of 4H–SiC substrates with different micropipe densities from CREE. For radiation hardness studies, the detectors have been irradiated with protons (24 GeV/c) at a fluence of about 1014 cm−2 and with electrons (8.2 MeV) and gamma-rays (60Co source) at doses ranging from 0 to 40 Mrad. We present experimental data on the charge collection properties by using 5.48, 4.14 and 2.00 MeV α-particles impinging on the Schottky contact. Hundred percent charge collection efficiency (CCE) is demonstrated for reverse voltages higher than the one needed to have a depletion region equal to the α-particle projected range, even after the irradiation at the highest dose. By comparing measured CCE values with the outcomes of drift–diffusion simulations, values are inferred for the hole lifetime, τp, within the neutral region of the charge carrier generation layer. τp was found to decrease with increasing radiation levels, ranging from 300 ns in non-irradiated detectors to 3 ns in the most irradiated ones. The diffusion contribution of the minority charge carriers to CCE is pointed out. [Copyright &y& Elsevier]

Discusses experimental results of the charge collection efficiency (cce) lateral uniformity in as prepared and proton irradiated semi-insulating liquid encapsulated Czochralsky gallium arsenide schottky detectors. Characterization of the detectors; Measurement of the degradation of the electron and hole collection efficiencies; Fabrication of detectors with low injecting ohmic contacts.

Focuses on the improved performance of gallium arsenide (GaAs) radiation detectors with low temperature ohmic contacts. Factor which limits the performance of the detector; Attempts by Alenia SPA to improve the process; Configuration of the introduced detectors; Results generated by the application of the detectors.

The article presents a study to analyze the impact of yellow head virus (YHV) on whiteleg shrimp or Penaeus vannamei in Mexican shrimp farms. The infected shrimp were soaked in 2 percent saline solution in a 1:10 ratio and centrifuged at 12000g for 5 min. It was again diluted in 2 percent saline solution in a 1:10 ratio and used to challenge shrimp at different salinities.

Platinum diffusion in n-type silicon has been measured using various kinds of spectroscopic techniques for deep energy levels. Platinum acts as an acceptor which captures electrons. An energy level of 0.23±0.02 eV was found for the trap. The diffusion profile can be explained, as in the case of gold, with a kick-out mechanism involving silicon self-interstitials. From the model, an activation energy of 5.01 eV for silicon self-interstitial diffusion can be inferred. [ABSTRACT FROM AUTHOR]

Presents a study that examined structural and electronic transport properties of silicide single crystals. Method of the study; Results and discussion; Conclusion.

Presents a study which examined the electrical transport properties of copper[sub3] germanium thin films. Effect of the increase in germanium concentration on electron transport properties; Experimental procedure; Results and discussion.

In this work, we propose a methodology to approach the design of chemical absorption columns with fast gas-liquid reactions by an experimental and modelling study, which accounts for thermodynamic (solubility) data, mass-transfer phenomena, and the reaction kinetics contribution. As a reference case, the SO 2 absorption in aqueous solution of H 2 O 2 at different concentrations, which oxidizes SO 2 to sulfuric acid, is considered. A lab-scale fed-batch bubble column is used to evaluate SO 2 solubility dataset in absorbing solutions of distilled water containing different dosages of H 2 O 2. A thermodynamic model is developed and validated in a Thermodynamic Flash block of ASPEN PLUS®, allowing to describe the experimental results with optimum agreement. For kinetic experiments, a lab-scale falling-film absorber is used to investigate both SO 2 mass-transfer rates and the fundamental kinetic aspects of an absorption process with chemical reaction. The physical contribution to the mass-transfer rate is evaluated through a set of dedicated experiments, which allowed determining gas-side (k G a) and liquid-side (k L a) coefficients in the falling-film absorber. Subsequently, the Enhancement factor (E L) of the SO 2 oxidative absorption is evaluated for the oxidizing reaction (SO 2 + H 2 O 2 → H 2 SO 4) under the explored experimental conditions, using the equilibrium dataset and the mass transfer coefficients previously obtained. Finally, E L is correlated to the Hatta number (Ha) with the Danckwerts kinetic model as a pseudo-mth-nth-order non-reversible reaction type and the model kinetic parameters are calculated. • This work provides an experimental and modelling approach to the design of reactive absorption columns. • The thermodynamic model developed in ASPEN PLUS provides a proper estimation of the SO 2 -H 2 O 2 solubility dataset. • The kinetic experiments allowed assessment of the reaction kinetic parameters in the gas absorption of SO 2 into H 2 O 2. • The kinetic model based on the Danckwerts equation provides a proper estimation of the Enhancement factors. [ABSTRACT FROM AUTHOR]

Abstract: Magnetic properties of melt spun and alloy series were studied by vibrating sample magnetometry and complex permeability measurements. The saturation magnetization exhibited an initial high value of 210emu/g followed by a decreasing tendency with increasing Al and B additions (up to 139emu/g). On the other hand, the initial permeability showed variations within the range 1000–2000, whereas the relaxation frequency displayed a maximum of 2MHz for the 4at% Al alloy. [Copyright &y& Elsevier]

The article presents a letter to the editor about the connection of the butterfly effect to hurricanes.

Background and Objective: Resistance of Helicobacter Pylori (H. pylori) to antibiotics is the main cause of relapse into Helcobacterial infections. With the use of several antibiotics that have synergistic effect, we can inhibit this antibiotic resistance. Thus, we aimed at determining resistance patterns and assessing the synergy of combining multiple antibiotics on H. pylori. Material and Methods: Biopsy specimens were taken from 100 patients with gastric ulcer referred to Imam Reza hospital in Amol, north of Iran. After isolation and identification of H. Pylori, antibiogram was performed with different antibiotic disks containing one antibiotic, a combination of two antibiotics (metronidazole + clarithromycin) and three antibiotics (metronidazole + Claritromycin + Ciprofloxacin). Results: In this study, H. pylori were isolated from 53 (53%) biopsy specimens. Of these, 49 (5.92%) were resistant to metronidazole, 14 (26%) to amoxicillin, 10 (19%) to clarithromycin, 7 (13%) to tetracycline, 13 (5/24%) to furazolidone and 7 (13%) to ciprofloxacin. In survey of synergistic effect, an increase in inhibition zone diameter around of combined disks was seen up to 5mm compared to the most effective antibiotic. Conclusion: The inhibition zone diameter of discs containing two and three antibiotics was large, in comparison with one antibiotic. [ABSTRACT FROM AUTHOR]

Background Kidney transplant recipients are at higher risk of developing pulmonary complications related to immunosuppression, and inhibitor of the mammalian target of rapamycin (mTORi) has been reported as a potential cause. Methods Five hundred kidney-transplanted patients were retrospectively analyzed for pulmonary complications on the basis of clinical and instrumental data (chest radiography, high-resolution computed tomography, broncho-alveolar lavage, oximetry). Results We found 26 interstitial lung diseases (ILD) (16%): 12 cases (46.2%) were from infections (42.8% by Pneumocystis jirovecii ) and 14 cases of ILD (53.8%) resulted as drug-induced ILD (DI–ILD). According to anti-rejection protocols, DI–ILD occurred in 8 patients (57%) while on triple regimen including steroids, everolimus (EVL), and cyclosporine (CyA) and in 6 patients on double regimen with steroids and mTORi: EVL or sirolimus (43%). In ILD+ patients, everolimus trough-concentration (EVL TLC ) and cyclosporine (2nd-hour concentration: CyA C2 ) levels were higher than in patients in the same regimen but with ILD− (EVL TLC [ng/mL] 9.84 versus 6.85; CyA C2 [ng/mL] 303.97 versus 298.56). The formula that used the combined blood levels of both drugs (EVL TLC + CyA C2 /100) resulted in a significant difference between groups of patients (12.88 ± 1.61 versus 9.83 ± 1.91). Applying receiver operator characteristic curve (ROC) analysis to detect risk of developing ILD when on combined protocol with EVL and CyA, we obtained an area under the curve of 0.8622 ( P = .0081) and 0.9082 ( P = .0028), respectively, when using EVL TLC or the combination formula with both drugs. Conclusions In renal transplant patients, we obtained a relationship of ILD to specific drug concentration. On the basis of ROC analysis, patients on EVL and CyA combined protocol are at risk of ILD when EVL TLC is >9.03 ng/mL or >11.41 when a formula with summation of EVL TLC and CyA C2 is used. [ABSTRACT FROM AUTHOR]

The relatively low value of the number of electron-hole (e-h) pairs per micron for Minimum Ionizing Particles (MIPs) in SiC against the value for Si, imposes severe constrains on the crystallographic quality, the thickness and the doping concentration of the SiC epitaxial layer used as detection medium. In this work, a 85 μm thick 4H-SiC epitaxial layer with a low doping concentration, Neff ≤ 1 × 1014 cm-3, was used in order to have a high number (≈4700) of e-h pairs generated by a MIP in the active region. We present experimental data on the charge spectrum for β MIPs from a 90Sr source, collected in a temperature range from room temperature up to 81°C. [ABSTRACT FROM AUTHOR]

Abstract: Lead and copper activation of pyrite in the presence of thiol collectors was examined by means of cyclic voltammetry and microflotation techniques. Di-isobutyl dithiophosphinate (Aerophine 3418A) and alkyl thionocarbamate (AERO 3894) were employed as collector of lead and copper, respectively. Otherwise, isopropyl xanthate (IPX) was also used as a collector of both: lead and copper. The results revealed that in the presence of non-conventional collectors, the increase in pyrite recovery due to the activation by copper and lead species, was noticeably smaller than that exhibited when xanthate (IPX) was used. The electrochemical response of pyrite indicates that lead activation favors the formation of dixanthogen. In non-xanthate systems, the voltammograms of pyrite remained unaffected regardless of the activation by lead or copper species. [Copyright &y& Elsevier]

Abstract: Charge collection efficiency (CCE) profiles of a semi-insulating (SI) gallium arsenide LEC (Liquid Encapsulated Czochralski) Schottky diode have been investigated by lateral Ion Beam Induced Charge collection (IBIC) technique. A focussed 2.4MeV proton microbeam was scanned over the cleaved surface of a SI-GaAs diode and the charge collection efficiency was evaluated as a function of the ion beam position at different bias voltages. By fitting the CCE profiles with the equations derived by the Shockley–Ramo–Gunn’s theorem, drift lengths of electrons and holes were obtained. Experimental results are consistent with previous OBIC (Optical Beam Induced Current) and SP (Surface Potential) measurements and confirm the model based on the formation of a Mott barrier due to the enhanced electron capture cross section in high field conditions. [Copyright &y& Elsevier]

Epitaxial SiC devices have been tested as radiation detectors for minimum ionising particles. The devices used are based on a commercial 4H–SiC epitaxial n-type layer deposited onto a 4H–SiC n+ type substrate wafer doped with nitrogen. Single-pad Schottky contacts have been produced by deposition of a 1000-A˚ gold film on the epitaxial layer using a lift-off technology and ohmic contacts have been deposited on the rear substrate side. The capacitance–voltage characteristics have been measured to determine the net effective doping in the space charge layer and the maximum active thickness of the devices. The measurements showed possible non-uniformity in the net doping of the epitaxial layer. The charge collection efficiency (CCE) has been tested by means of a 0.1 mCi 90Sr β-source. A 100% CCE is measured at the maximum active thickness, which is achieved above approximately 400 V. The charge signal of the SiC devices is stable and reproducible, with no evidence of priming or polarisation effects, due to the high crystalline quality of the epitaxial layer. [Copyright &y& Elsevier]

This article concerns the existence of a double-junction effect in proton-irradiated silicon p[sup +] υ-n[sup +] (pin) diodes demonstrated by surface potential and optical-beam-induced current (OBIC) investigations. By increasing the diode biasing, the junctions existing at both ends in the irradiated devices move towards each other up to join, hence, causing a full depletion of the diodes. Due to the inhomogeneity of the electric field, however, the charge-carrier collection is strongly dependent on the position. The extent of the diode depletion layers at both ends and the shape of the electric field within the p[sup +]-υ-n[sup +] diodes are determined as a function of the bias applied. Three-dimensional photocurrent maps obtained by OBIC profiles allow for imaging the double junction. The deep level analysis evidences the presence of irradiation-induced defects, which are responsible for the double-junction effect. [ABSTRACT FROM AUTHOR]

Presents a study that obtained different cobalt (Co)-silicide compounds by solid-state reaction in thin bilayers of amorphous silicon and Co evaporated on silicon dioxide substrates. Crystallographic characteristics of the samples; Type of phase present in the results; Application of Hall effect measurements on van der Pauw structures.

Presents a study which examined the hafnium disilicide polycrystalline thin films, grown by coevaporation of hafnium and silicon, by electrical resistivity measurements, Hall voltage and optical reflectance. Composition and structure of the films; Electrical transport measurements; Measurement of the reflectance spectrum.

Investigates the electrical and optical properties of gadolinium and erbium disilicide. Reason for the interest in transition-metal silicides; X-ray diffractometry used in identifying the silicide phases present in the films; Depth composition and film thickness of the silicides.

Introduction: Major depressive disorder (MDD) is highly prevalent in the general population and among medical students (MS). Risk factors of depression in MS are important to clarify. Objectives: To determine the prevalence of depressive symptoms and its changes during 5 years of medical school. Which are the factors associated with depressive symptomatology and how these factors change over time. Methods: A prospective, longitudinal observational study was conducted at the Medical School of the National University of Mexico, between 2012-2018. We included students who maintained their participation annually, completing the patient health questionnaire (PHQ-9) and the survey on socio-demographic variables in order to evaluate potential predictors, personal and academic characteristics and perceived academic difficulties. Results: The response rate was between 78-89%. 245 MS were evaluated longitudinally, 60.9% were women, 97.2% single, 96.5% lived with their family or partner and 71% received sufficient financial resources for living costs. For depression the prevalence ranged from 10.5-16.2% according to the academic year. The multiple logistic regression analysis per year showed that the history of emotional abuse in childhood (OR=1.89-3.11, p<0.05), anxiety levels (OR=1.85-2.97, p<0.05), poor financial resources (OR=3.11-4.54, p<0.05) and being female (OR=1.83-2.02, p<0.05) increase the risk of depressive symptoms. Conclusions: Our findings suggest that personal factors (female, poor financial resources, anxiety and history of child abuse) are relevant for persistence of high score of PHQ-9. Medical schools need to identity students who have depressive symptoms and offer them, as early as possible, particularly when depression has been present over time. [ABSTRACT FROM AUTHOR]

Abstract: The interaction of sodium-di-isobutyl dithiophosphinate (DTPINa) with galena and pyrite in alkaline media (pH 9) was examined using cyclic voltammetry, open circuit potential and contact angle techniques. Analysis of results suggests that the collector interacts with the minerals by chemical and electrochemical mechanisms according to the following steps: a chemisorption process (without electron transfer) that takes place when the collector interacts with metal species (e.g., of lead) that shows chemical affinity towards the collector; an electrochemical–chemical process developed by the galena that involves two steps: the oxidation of the mineral (electrochemical step) and the formation of a metal–collector precipitate (chemical step); and an electrochemical process (adsorption of collector and dimer formation) that occurs when pyrite is held at a redox potential sufficiently anodic to produce oxidation of the collector. [Copyright &y& Elsevier]