Search

Publications are an important component of academic careers. We investigated the financial costs to authors for submitting and publishing manuscripts in gastroenterology (GI) journals in the United States (US), United Kingdom (UK), and elsewhere. This was a cross-sectional study carried out from 11/1/2020 to 12/31/2020. We used the SCImago Journal and Country Rankings site to compile a list of gastroenterology and hepatology journals to analyze. We gathered information on the journals’ Hirsch indices (h indices), SCImago Journal Rank (SJR), Impact Factor (IF), and base countries as of 2019, processing and publication fees, open access fees, time to first decision, and time from acceptance to publication. We used t-testing and linear regression modeling to evaluate the effect of geography and journal quality metrics on processing fees and times. We analyzed 97 GI journals, of which 51/97 (52.6%) were based in the US/UK while the other 46/97 (47.4%) were based elsewhere. The mean IF (5.67 vs 3.53, p = 0.08), h index (90.5 vs 41.8, p

We propose two postprocessing procedures (Patch method and Stitch method) to recover local conservation of velocity fields produced by multiscale approximations that are only conservative in coarse scales. These procedures operate on small overlapping regions and are designed to be implemented in parallel, which makes them relatively inexpensive. We investigate the applicability of such methods when tested on single-phase flow problems using the Multiscale Robin Coupled Method (MRCM) in highly heterogeneous permeability fields for modeling the contaminant transport in the subsurface. Numerical simulations are presented aiming to illustrate and compare the performance of the new methods with a standard procedure, the Mean method, in terms of accuracy in contaminant concentration. We show that for a collection of permeability fields taken as log-normal fields, the new postprocessing procedures provide similar or better accuracy than the Mean method. Then, we turn our attention to flows in high-contrast channelized porous formations, where the new methods robustly yield more accurate results and should thus be favored.

In the present work, a magnetodielectric flexible thick film composite with a quaternary Ba12Fe28Ti15O84 ferrite filler (≤ 9 vol%) embedded into PVDF polymer matrix was investigated. The role of filler volume on the macroscopic dielectric, magnetic and ferroelectric properties as well as on the nanoscale magnetic and piezoelectric response was analyzed. The formation of small amounts of polar phases besides the majority α-phase of PVDF was shown by XRD and FTIR combined analysis. The electrical properties are dominated by the polymer response, while magnetic order is derived as sum property from the ferrite ones, having a predominant soft magnetic character with small coercivity of Hc ~ 60 Oe and high saturation magnetization of Ms = 2.6 emu/g for the highest concentration of 9 vol%. Permittivity and losses slightly increase with ferrite filler addition, and the composite maintains a dielectric character for all the compositions. Local PFM and MFM investigations have shown a combined ferro/piezoelectric character and magnetic order, with magnetoelectric coupling demonstrated by the reorientation of filler particles and modifications of local piezoresponse when applying a static magnetic field.

Gunflints represent a worldwide feature of lithic technology in modern times. This type of artefact was used to ignite the powder of firearms through a flintlock mechanismfrom the middle-seventeenth to the early-twentieth century in different contexts aroundthe world. Taking what is a novel and exploratory approach in historical archaeology, this paper offers a quantitative analysis of a random sample of 200 unused gunflints recovered from the British shipwreck Deltebre I. This cargo ship belonged to an alliedconvoy that unsuccessfully tried to liberate Tarragona city from the Napoleonic forces, and sunk in the Ebro river delta, Catalonia, Spain, in 1813. The results from size and shape characterisation of the unused gunflints using geometric morphometric methodsare presented. In order to assess morphometric variation between used and unused artefacts, this sample was compared with published images of 22 used British gunflints from different archaeological contexts. Finally, the usefulness of applied methodology to quantitatively characterise the design and morphometric variations of this kind of artefacts is highlighted. Fil: Ciarlo, Nicolás Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Arqueología; Argentina Fil: Charlin, Judith Emilce. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina Fil: Alberti, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentina Fil: Buscaglia, Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentina Fil: Vivar Lombarte, Gustau. Centro de Arqueología Subacuática de Catalunia; España Fil: Geli Mauri, Rut. Centro de Arqueología Subacuática de Catalunia; España

Organoids are three-dimensional in vitro models of human disease developed from benign and malignant gastrointestinal tissues with tremendous potential for personalized medicine applications. We sought to determine whether gastric cancer patient-derived organoids (PDOs) could be safely established from endoscopic biopsies for rapid drug screening. Patients underwent esophagogastroduodenoscopy (EGD) for surveillance or staging and had additional forceps biopsies taken for PDO creation. Cancer tissues from operative specimens were also used to create PDOs. To address potential tumor heterogeneity, we performed low-coverage whole-genome sequencing of endoscopic-derived PDOs with paired surgical PDOs and whole-tumor lysates. The stability of genomic alterations in endoscopic organoids was assessed by next-generation sequencing and nested polymerase chain reaction (PCR) assay. The feasibility and potential accuracy of drug sensitivity screening with endoscopic-derived PDOs were also evaluated. Gastric cancer PDOs (n = 15) were successfully established from EGD forceps biopsies (n = 8) and surgical tissues (n = 7) from five patients with gastric adenocarcinoma. Low-coverage whole-genomic profiling of paired EGD and surgical PDOs along with whole-tumor lysates demonstrated absence of tumor heterogeneity. Nested PCR assay identified similar KRAS alterations in primary tumor and paired organoids. Drug sensitivity testing of endoscopic-derived PDOs displayed standard dose–response curves to current gastric cancer cytotoxic therapies. Our study results demonstrate the feasibility of developing gastric cancer PDOs from EGD biopsies. These results also indicate that endoscopic-derived PDOs are accurate surrogates of the primary tumor and have the potential for drug sensitivity screening and personalized medicine applications.

This paper highlights the agency of indigenous peoples in the manipulation, alteration, and/or definition of limits to the colonial order established in Patagonia by the end of the eighteenth century. Hence, it rests on the ideas of the ambivalence of power and intercultural relations. Interethnic relationships are explored in two case studies from the same colonizing project: “Nueva Colonia y Fuerte de Floridablanca” (San Julián Bay, Santa Cruz province) and “Fuerte San José” (Valdés peninsula, Chubut province). Social practices, material conditions of the colonial settlements, and particularly, the indigenous perceptions of the colonial posts are thoroughly considered. This information is thus intended to discuss the divergent trajectories of interethnic relationships, as well as to approach colonialism in Patagonia from the natives’ logics. Fil: Buscaglia, Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentina

In recent years the acknowledgment of the importance of peripheral realities, local contexts and social actors? roles in shaping both colonialism and modern society has contributed to challenge the conception of colonialism as a monolithic, unilinear process. This article explores this problematic through the historical and archaeological study of the Spanish colonization of Patagonia. It describes the case of Fuerte San José (Valdes Peninsula, Chubut Province, Argentina), a military fort which lasted between 1779 and 1810, which is discussed as an example of how colonization actually operated within a wider colonial context. Here, the integration of historical and archaeological evidence provides the means for contrasting the planning and the implementation of colonial projects in order to uncover its complex and multifaceted character. Fil: Buscaglia, Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentina Fil: Bianchi Villelli, Marcia Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio. Universidad Nacional de Río Negro. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio; Argentina

Cystic fibrosis (CF), one of the most common fatal hereditary disorders, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR gene product is a multidomain adenosine triphosphate-binding cassette (ABC) protein that functions as a chloride (Cl(-)) channel that is regulated by intracellular magnesium [Mg(2+)]i. The most common mutations in CFTR are a deletion of a phenylalanine residue at position 508 (ΔF508-CFTR, 70-80 % of CF phenotypes) and a Gly551Asp substitution (G551D-CFTR, 4-5 % of alleles), which lead to decreased or almost abolished Cl(-) channel function, respectively. Magnesium ions have to be finely regulated within cells for optimal expression and function of CFTR. Therefore, the melastatin-like transient receptor potential cation channel, subfamily M, member 7 (TRPM7), which is responsible for Mg(2+) entry, was studies and [Mg(2+)]i measured in cells stably expressing wildtype CFTR, and two mutant proteins (ΔF508-CFTR and G551D-CFTR). This study shows for the first time that [Mg(2+)]i is decreased in cells expressing ΔF508-CFTR and G551D-CFTR mutated proteins. It was also observed that the expression of the TRPM7 protein is increased; however, membrane localization was altered for both ΔF508del-CFTR and G551D-CFTR. Furthermore, both the function and regulation of the TRPM7 channel regarding Mg(2+) is decreased in the cells expressing the mutated CFTR. Ca(2+) influx via TRPM7 were also modified in cells expressing a mutated CFTR. Therefore, there appears to be a direct involvement of TRPM7 in CF physiopathology. Finally, we propose that the TRPM7 activator Naltriben is a new potentiator for G551D-CFTR as the function of this mutant increases upon activation of TRPM7 by Naltriben.

Background The optimal approach to the drainage of malignant obstruction at the liver hilum remains uncertain. We aim to compare percutaneous transhepatic biliary drainage (PTBD) to endoscopic retrograde cholangiography (ERC) as the first intervention in patients with cholestasis due to suspected malignant hilar obstruction (MHO). Methods The INTERCPT trial is a multi-center, comparative effectiveness, randomized, superiority trial of PTBD vs. ERC for decompression of suspected MHO. One hundred and eighty-four eligible patients across medical centers in the United States, who provide informed consent, will be randomly assigned in 1:1 fashion via a web-based electronic randomization system to either ERC or PTBD as the initial drainage and, if indicated, diagnostic procedure. All subsequent clinical interventions, including crossover to the alternative procedure, will be dictated by treating physicians per usual clinical care. Enrolled subjects will be assessed for successful biliary drainage (primary outcome measure), adequate tissue diagnosis, adverse events, the need for additional procedures, hospitalizations, and oncological outcomes over a 6-month follow-up period. Subjects, treating clinicians and outcome assessors will not be blinded. Discussion The INTERCPT trial is designed to determine whether PTBD or ERC is the better initial approach when managing a patient with suspected MHO, a common clinical dilemma that has never been investigated in a randomized trial. Trial registration ClinicalTrials.gov, Identifier: NCT03172832. Registered on 1 June 2017. Electronic supplementary material The online version of this article (10.1186/s13063-018-2473-2) contains supplementary material, which is available to authorized users.

Endoscopic therapy is considered first line for management of benign biliary strictures (BBSs). Placement of plastic stents has been effective but limited by their short-term patency and need for repeated procedures. Fully covered self-expandable metallic stents (FCSEMSs) offer longer-lasting biliary drainage without the need for frequent exchanges. The aim of this study was to assess the efficacy and safety of FCSEMS in patients with BBS. A retrospective review of all patients who underwent ERCP and FCSEMS placement at five tertiary referral US hospitals was performed. Stricture resolution and adverse events related to ERCP and/or stenting were recorded. A total of 123 patients underwent FCSEMS placement for BBS and 112 underwent a subsequent follow-up ERCP. The mean age was 62 years (±15.6), and 57 % were males. Stricture resolution occurred in 81 % of patients after a mean of 1.2 stenting procedures (mean stent dwell time 24.4 ± 2.3 weeks), with a mean follow-up of 18.5 months. Stricture recurrence occurred in 5 patients, and 3 patients required surgery for treatment of refractory strictures. Stent migration (9.7 %) was the most common complication, followed by stent occlusion (4.9 %), cholangitis (4.1 %), and pancreatitis (3.3 %). There was one case of stent fracture during removal, and one stent could not be removed. There was one death due to cholangitis. Majority of BBS can be successfully managed with 1–2 consecutive FCSEMS with stent dwell time of 6 months.

Introduction: Lasers 2-microm in wavelength offer efficient tissue cutting with limited thermal damage in biological tissue. Objective: To evaluate the dissection capabilities of a 2-microm continuous-wave laser for NOTES procedures. Methods and procedures: We conducted 18 acute animal experiments. Group 1 (three animals): transcolonic access to the peritoneal cavity (15-W transcolonic laser puncture, balloon dilation over the laser probe). Group 2 (six animals): transcolonic access with needle-knife puncture and balloon dilation. Group 3 (three animals): transgastric access to the peritoneal cavity (similar technique as group 1) followed by laser-assisted dissection of the kidney. In one animal of group 3, a therapeutic target (hematoma) was created by percutaneous puncture of the kidney. Group 4 (six animals): transgastric access (similar to the technique of group 2). Results: Translumenal access to the peritoneal cavity was achieved in 2-3 min in group 1 (significantly shorter than with the needle-knife-assisted technique, 4-5 min, p=0.02) and in 7-10 min in group 3 (compared to 6-17 min in group 4, p=0.88). In group 3, laser dissection of the parietal peritoneum and of perinephric connective tissue allowed access to the retroperitoneum with complete removal of a blood collection in the animal with puncture trauma. Laser dissection demonstrated good maneuverability, clean and rapid cutting, and excellent hemostasis. Peritoneoscopy and necropsy showed no damage of targeted tissue and surrounding organs. Conclusions: The 2-microm continuous-wave laser system showed promising capabilities for highly precise and safe dissection during NOTES procedures.

The conservation of artworks requires a profound knowledge about pictorial materials, their chemical and physical properties and their interaction and/or degradation processes. For this reason, pictorial materials databases are widely used to study and investigate cultural heritage. At Centre for Conservation and Restoration La Venaria Reale, we prepared a set of about 1200 mock-ups with 173 different pigments and/or dyes, used across all the historical times or as products for conservation, four binders, two varnishes and four different materials for underdrawings. In collaboration with the Laboratorio Analisi Scientifiche of Regione Autonoma Valle d’Aosta, the National Institute of Metrological Research and the Department of Architecture and Design of the Polytechnic of Turin, we created a scientific database that is now available online ( http://www.centrorestaurovenaria.it/en/areas/diagnostic/pictorial-materials-database ) designed as a tool for heritage science and conservation. Here, we present a focus on materials for pictorial retouching where the hyperspectral imaging application, conducted with a prototype of new technology, allowed to provide a list of pigments that could be more suitable for conservation treatments and pictorial retouching. Then we present the case study of the industrial painting Notte Barbara (1962) by Pinot Gallizio where the use of the database including modern and contemporary art materials showed to be very useful and where the fibre optics reflectance spectroscopy technique was decisive for pigment identification purpose. Later in this research, the mock-ups will be exploited to study degradation processes, e.g., the lightfastness, or the possible formation of interaction products, e.g., metal carboxylates.

Recent studies (Cragg and Woof, Bus Soc Rev 107(1):98–144, 2002; Weismann, J Bus Ethics 88:615–66, 2009) revealed that in the first 28 years of its existence, the Foreign Corrupt Practices Act was not enforced by the federal government. The Weismann study further concluded that the FCPA, designed by Congress as a self-regulatory model of corporate governance, failed to achieve the regulatory goal of deterring global bribery by U.S. companies. The current article addresses the reasons that the FCPA remains an ineffective measure to control bribery as a global market entry strategy despite the highly publicized 2006 Department of Justice initiative to increase prosecutions and tighten enforcement efforts. The failure arises out of both the increased use of informal dispositions of case prosecutions, (including non-prosecution and deferred prosecution agreements), which has made “getting caught” merely an increased “cost of doing business” and the failure to close the regulatory gaps in the statute that permit violators to slip through the enforcement net. The article updates and compiles the case prosecution data for every reported case prosecuted between 1977 and 2011. That data are then compared to the results of a 2010 integrity risk survey performed by Deloitte Financial Advisory Services and Forbes which reveal a widely held global business perception that compliance and integrity risks appear to be rising sharply and that the FCPA is ineffective in deterring bribery and corruption in foreign markets. The article aims to serve as a predictive tool for policy makers and business professionals in assessing risk in the global markets, particularly as commerce intensifies in the BRIC countries, notable for bribery and corruption.

Elemental analysis of glass was conducted by 16 forensic science laboratories, providing a direct comparison between three analytical methods [micro-x-ray fluorescence spectroscopy (μ-XRF), solution analysis using inductively coupled plasma mass spectrometry (ICP-MS), and laser ablation inductively coupled plasma mass spectrometry]. Interlaboratory studies using glass standard reference materials and other glass samples were designed to (a) evaluate the analytical performance between different laboratories using the same method, (b) evaluate the analytical performance of the different methods, (c) evaluate the capabilities of the methods to correctly associate glass that originated from the same source and to correctly discriminate glass samples that do not share the same source, and (d) standardize the methods of analysis and interpretation of results. Reference materials NIST 612, NIST 1831, FGS 1, and FGS 2 were employed to cross-validate these sensitive techniques and to optimize and standardize the analytical protocols. The resulting figures of merit for the ICP-MS methods include repeatability better than 5% RSD, reproducibility between laboratories better than 10% RSD, bias better than 10%, and limits of detection between 0.03 and 9 μg g(-1) for the majority of the elements monitored. The figures of merit for the μ-XRF methods include repeatability better than 11% RSD, reproducibility between laboratories after normalization of the data better than 16% RSD, and limits of detection between 5.8 and 7,400 μg g(-1). The results from this study also compare the analytical performance of different forensic science laboratories conducting elemental analysis of glass evidence fragments using the three analytical methods.

The interpretation of the meanings of constructed space plays an important role in understanding how a certain society might have been structured in the past. This paper presents the colony of Floridablanca (Patagonia, 18th century) and examines how the different discourse levels are articulated in the construction of the colony's spaces according to the ideal model of a social order based on the principles of the Spanish Enlightenment. The focus is on the convergence and divergence between the material world and the narratives referring to such spaces created during the existence of the colony. This approach, developed by an interdisciplinary team, involved the inclusion and interpretation of historical, archaeological, and geophysical data. Studied along three lines of evidence, the narrative analyses and material construction show how the discourse on the social organization of Floridablanca articulates convergence and divergence from these planes in different ways for different sectors of the colony. Fil: Buscaglia, Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: Senatore, Maria Ximena. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: Lascano, Eugenia. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: Bongiovanni, Maria Victoria Flavia. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: de la Vega, Matias. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: Osella, Ana Maria. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina

Background: Magnesium deficiency has been implicated as a possible contributing factor to some symptoms of premenstrual syndrome (PMS) and several studies have reported a lower intracellular magnesium concentration in women with PMS. Thus, it has been suggested that magnesium supplementation may improve certain symptoms in women with PMS. Objective: This open-label study assessed the efficacy and safety of a patented modified-release magnesium 250mg tablet for improving symptoms in women affected by PMS. Methods: After a 3-month observational period, women aged 18–5 years with a regular menstrual cycle (from 25–35 days) who were affected by PMS (determined by a score of >-25 points on a PMS questionnaire) [n = 41] were given the modified-release magnesium tablet over three menstrual cycles, beginning 20 days after the start of their last menstrual period and continuing until the start of their next menstrual period. Results: PMS symptoms improved during magnesium treatment. After 3 months, the mean total PMS score (primary endpoint), as assessed by the investigator using Moos’ Modified Menstrual Distress Questionnaire, was significantly lower than before therapy (p < 0.0001). During the same period, the mean PMS scores, as recorded in patients’ diaries (secondary efficacy variables), also showed significant improvements (p < 0.0001 for all subscales). The relative decreases in total PMS scores, as assessed by investigator and patient, were 35.1% and 33.5%, respectively. The magnesium tablet was well tolerated, with vertigo the only treatment-related adverse event reported (one patient). Conclusions: We concluded that modified-release magnesium was effective in reducing premenstrual symptoms in women with PMS in this preliminary study.

The surface of the protozoan parasite Trypanosoma cruzi is covered in mucins, which contribute to parasite protection and to the establishment of a persistent infection. Their importance is highlighted by the fact that the approximately 850 mucin-encoding genes comprise approximately 1% of the parasite genome and approximately 6% of all predicted T. cruzi genes. The coordinate expression of a large repertoire of mucins containing variable regions in the mammal-dwelling stages of the T. cruzi life cycle suggests a possible strategy to thwart the host immune response. Here, we discuss the expression profiling of T. cruzi mucins, the mechanisms leading to the acquisition of mucin diversity and the possible consequences of a mosaic surface coat in the interplay between parasite and host.

This paper examines the contribution of the PhD dissertation of the American cytologist Michael F. Guyer (1874-1959) to the early establishment (in 1902-1903) of the parallel relationship between cytological chromosome behaviour in meiosis and Mendel's laws. Guyer's suggestions were among the first, which attempted to relate the variation observed in the offspring in hybridisation studies by a coherent cytological chromosome mechanism to meiosis before the rediscovery of Mendel's principles. This suggested for the first time that the chromosome mechanism involved a conjugation of maternal and paternal chromosomes during the synapsis followed by a segregation of parental chromosomes in the final germ cells and a random union of the final germ cells in the fertilization. It shows that this early suggestion was similar to William Austin Cannon's later chromosome proposal attempting to explain Mendel's principles and had some influence on Walter Sutton's cytological suggestion explaining correctly the behaviour of Mendel's particle by 1903.

An approach is proposed for fabricating fine-grained, low-resistivity BaTiO3-based PTCR ceramics via partial isovalent substitutions on the Ba site. The grain size of the ceramics thus prepared is shown to decrease as the ratio of ionic radii r(Ba2+)/r(M2+) (M = Ca, Sr, Pb) increases. Isovalent substitutions on the Ba site narrow down the range of donor dopant (yttrium) concentrations in which PTCR materials can be prepared. The experimental results agree well with thermodynamic calculations under the assumption that the materials contain the Y3+Ti3+O3 phase, as suggested by ESR data, which point to the presence of Y3+–Ti3+ associates. Partial calcium, strontium, and lead substitutions on the Ba site reduce the average grain size of PTCR ceramics, which is probably due to the lattice strain arising from the isovalent substitution. Partial replacement of Ba2+ with mixtures of different isovalent elements (e.g., Sr2+ and Pb2+) offers the possibility of obtaining fine-grained, low-resistivity PTCR ceramics, without changing the phase transition temperature.

The reaction between Fe2O3 (hematite) and Sb2O3 leading to the formation of the rutile-type compound FeSbO4 was analysed by means of DTA and TG, performed under various O2 partial pressures up to 1673 K. The reaction products were identified by means of XRD analysis. Three transformations occur in the analysed temperature range: 1. oxidation of Sb2O3 to Sb2O4 between 745 and 768 K; 2. formation of FeSbO4 between 1226 and 1246 K; 3. decomposition of FeSbO4 without melting above 1543-1591 K. The TG-DTA and XRD analysis results indicate that deviations from perfect stoichiometry are likely to exist inside FeSbO4.

Two-scale numerical homogenization problems are addressed, with particular application to the modified compressible Reynolds equation with periodic roughness. It is shown how to calculate sensitivities of the homogenized coefficients that come out from local problems. This allows for significant reduction of the computational cost by two means: The construction of accurate Taylor expansions, and the implementation of rapidly convergent nonlinear algorithms (such as Newton's) instead of fixed-point-like ones. Numerical tests are reported showing the quantitative accuracy of low-order Taylor expansions in practical cases, independently of the shape and smoothness of the roughness function.

To investigate plasma concentrations of lipoprotein(a) [Lp(a)] and apolipoprotein(a) [apo(a)] polymorphism in relation to the presence of microvascular and neurological complications in type 1 diabetes mellitus, 118 young diabetic patients and 127 age-matched controls were recruited. Lp(a) levels were higher in patients than in controls, but the apo(a) isoforms distribution did not differ between the two groups [higher prevalence of isoforms of high relative molecular mass (RMM) in both groups]. Microalbuminuric patients had Lp(a) levels significantly greater than normoalbuminuric patients, and normoalbuminuric patients showed higher Lp(a) levels than controls. Patients with retinopathy or neuropathy showed similar Lp(a) levels to those without retinopathy or neuropathy. No differences in apo(a) isoforms frequencies were observed between subgroups with and without complications (higher prevalence of isoforms of high RMM in every subgroup). However, among patients with retinopathy, those with proliferative retinopathy had higher Lp(a) levels and a different apo(a) isoforms distribution (higher prevalence of isoforms of low RMM) than those with non-proliferative and background retinopathy (higher prevalence of isoforms of high RMM). Our data suggest that young type 1 diabetic patients without microalbuminuria have Lp(a) levels higher than healthy subjects of the same age. Lp(a) levels are further increased in microalbuminuric patients. High Lp(a) levels and apo(a) isoforms of low RMM seem to be associated with the presence of proliferative retinopathy, but have no relation to neuropathy.

A low-thermal-expansion ceramic with the composition Al0.8Mg0.6Ti1.6O5 that is isostructural to aluminium titanate Al2TiO5, was prepared by solid-state reaction of a mixture of α-Al2O3, MgO and TiO2-rutile. The synthesized material does not decompose after annealing for 250 h in the temperature range of 900–1175°C. The ceramic sintered at 1350°C has a 97% relative density, a grain size of ≈5 μm and an average thermal expansion coefficient between 80 and 1000°C of ≈2×10−6 K−1. Materials with the same composition, but obtained by reaction sintering, have a higher thermal expansion coefficient (4×10−6 K−1) and showed the presence of secondary phases.