Gastrointestinal Motility in Health and Disease

Michael Zabinski (with Biancani, P., M. P. Zabinski, M. D. Kerstein, and J. Behar) is a contributing author, Comparison of mechanical characteristics of the lower oesophageal sphincter and pyloric sphincter, p.547-551. Book description: Proceedings of the 6th International Symposium on Gastrointestinal Motility, held at the Royal College of Surgeons of Edinburgh, 12–16th September, 1977.https://digitalcommons.fairfield.edu/engineering-books/1036/thumbnail.jp

New membranes obtained by grafted irradiated PVDF foils

The present work describes a new method to produce membranes of poly(Acrylicacid-Xmonomer) using the grafting procedure. PVDF foils irradiated with Ar+ beamwith energies between 30 and 150 keV were employed as substratum. Differentcombinations of monomers in water solutions were used: acrylic acid (AAc); acrylicacid - glycidyl methacrylate (AAc-GMA); acrylic acid - styrene (AAc-S), acrylic acid-N-isopropyl acrylamide (AAc-NIPAAm) and acrylic acid - N-isopropyl acrylamide -glycidyl methacrylate (AAc-NIPAAm-GMA). A large percentage of grafting results forspecific values of: ion fluence and energy, AAc and sulfuric acid concentration, anddifferent substrata PVDF polymorphous (alpha or beta). At a particular time of thegrafting process, the Poly(AAc-Xmonomer) membranes detach from the substratum andcontinue their grafting in the solution. This method is useful to produce increasedreplicated membranes of the irradiated original surface.Fil: Mazzei, R.. Universidad Tecnológica Nacional; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Garcia Bermudez, Gerardo Jose. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Camporotondi, Daniela Edhit. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Constituyentes); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Arbeitman, Claudia Roxana. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: del Grosso, Mariela Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad Tecnológica Nacional. Facultad Regional General Pacheco; ArgentinaFil: Behar, M.. Universidade Federal do Rio Grande do Sul; Brasi

Recent acquisition of Helicobacter pylori by Baka Pygmies

Both anatomically modern humans and the gastric pathogen Helicobacter pylori originated in Africa, and both species have been associated for at least 100,000 years. Seven geographically distinct H. pylori populations exist, three of which are indigenous to Africa: hpAfrica1, hpAfrica2, and hpNEAfrica. The oldest and most divergent population, hpAfrica2, evolved within San hunter-gatherers, who represent one of the deepest branches of the human population tree. Anticipating the presence of ancient H. pylori lineages within all hunter-gatherer populations, we investigated the prevalence and population structure of H. pylori within Baka Pygmies in Cameroon. Gastric biopsies were obtained by esophagogastroduodenoscopy from 77 Baka from two geographically separated populations, and from 101 non-Baka individuals from neighboring agriculturalist populations, and subsequently cultured for H. pylori. Unexpectedly, Baka Pygmies showed a significantly lower H. pylori infection rate (20.8%) than non-Baka (80.2%). We generated multilocus haplotypes for each H. pylori isolate by DNA sequencing, but were not able to identify Baka-specific lineages, and most isolates in our sample were assigned to hpNEAfrica or hpAfrica1. The population hpNEAfrica, a marker for the expansion of the Nilo-Saharan language family, was divided into East African and Central West African subpopulations. Similarly, a new hpAfrica1 subpopulation, identified mainly among Cameroonians, supports eastern and western expansions of Bantu languages. An age-structured transmission model shows that the low H. pylori prevalence among Baka Pygmies is achievable within the timeframe of a few hundred years and suggests that demographic factors such as small population size and unusually low life expectancy can lead to the eradication of H. pylori from individual human populations. The Baka were thus either H. pylori-free or lost their ancient lineages during past demographic fluctuations. Using coalescent simulations and phylogenetic inference, we show that Baka almost certainly acquired their extant H. pylori through secondary contact with their agriculturalist neighbors

A Reemerging Bright Soft X-Ray State of the Changing-look Active Galactic Nucleus 1ES 1927+654:A Multiwavelength View

1ES1927+654 is a nearby active galactic nucleus (AGN) that has shown an enigmatic outburst in optical/UV followed by X-rays, exhibiting strange variability patterns at timescales of months to years. Here we report the unusual X-ray, UV, and radio variability of the source in its postflare state (2022 January–2023 May). First, we detect an increase in the soft X-ray (0.3–2 keV) flux from 2022 May to 2023 May by almost a factor of 5, which we call the bright soft state. The hard X-ray 2–10 keV flux increased by a factor of 2, while the UV flux density did not show any significant changes (≤30%) in the same period. The integrated energy pumped into the soft and hard X-rays during this period of 11 months is ∼3.57 × 10 ^50 erg and 5.9 × 10 ^49 erg, respectively. From the energetics, it is evident that whatever is producing the soft excess (SE) is pumping out more energy than either the UV or hard X-ray source. Since the energy source presumably is ultimately the accretion of matter onto the supermassive black hole, the SE-emitting region must be receiving the majority of this energy. In addition, the source does not follow the typical disk–corona relation found in AGNs, neither in the initial flare (from 2017 to 2019) nor in the current bright soft state (2022–2023). We found that the core (<1 pc) radio emission at 5 GHz gradually increased until 2022 March, but showed a dip in 2022 August. The Güdel–Benz relation ( L _radio / L _X-ray ∼ 10 ^−5 ), however, is still within the expected range for radio-quiet AGNs, and further follow-up radio observations are currently being undertaken

Multiple ethnic origins of mitochondrial DNA lineages for the population of Mauritius

This article reports on the first genetic assessment of the contemporary Mauritian population. Small island nodes such as Mauritius played a critical role in historic globalization processes and revealing high-resolution details of labour sourcing is crucial in order to better understand early-modern diaspora events. Mauritius is a particularly interesting case given detailed historic accounts attesting to European (Dutch, French and British), African and Asian points of origin. Ninety-seven samples were analysed for mitochondrial DNA to begin unravelling the complex dynamics of the island’s modern population. In corroboration with general demographic information, the majority of maternal lineages were derived from South Asia (58.76%), with Malagasy (16.60%), East/Southeast Asian (11.34%) and Sub-Saharan African (10.21%) also making significant contributions. This study pinpoints specific regional origins for the South Asian genetic contribution, showing a greater influence on the contemporary population from northern and southeast India. Moreover, the analysis of lineages related to the slave trade demonstrated that Madagascar and East Asia were the main centres of origin, with less influence from West Africa

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Lattice site investigation of F in preamorphized Si

The lattice location of F atoms in Si was experimentally studied. Si single crystals were amorphized, implanted with F, and afterwards the amorphous layer was recrystallized. Some of the samples prepared in this way were also annealed at 750 °C for 60 min. The 19F (p, α ƴ)16 resonant nuclear reaction at 340.5 keV was employed to measure the probability of a close encounter between protons and F nuclei as a function of the incident angle with respect to six major crystalline directions. The predictions of several ab initio calculations proved to be incompatible with the present experimental findings

Conception et réalisation d'ébulliomètres comparatifs pour la détermination de grandes masses molaires en nombre (application à l'étude des fractions lourdes du pétrole)

Cette étude en six chapitres concerne la détermination de masses moyennes de macromolécules. Elle présente tout d'abord un chapitre sur les différentes distributions des masses molaires et un chapitre sur les différentes techniques de détermination de masse molaire élevée, plus particulièrement sur la technique ébulliométrique, ses éléments constitutifs, sa théorie. Sont ensuite exposés deux chapitres relatifs à la réalisation de deux ébulliomètres comparatifs, l'un en verre, l'autre en acier inoxydable et leur étalonnage respectif. L'ébulliomètre en verre donne une précision moyenne de 2 % pour des étalons couvrant le domaine 150/1000 g/mol, une reproductibilité de 1 % et une sensibilité de +- 2.10 C puissance -3. L'ébulliomètre en acier donne une précision de 2 % sur le domaine d'étalonnage 150-13000 g/mol, une reproductibilité de 1 % et une stabilité de +-2.10 C. puissance -4. Ce second appareil aura également donné lieu à une courte étude sur l'acquisition informatique et les gestions d'interface plus détaillée en annexe 1. Les deux derniers chapitres traitent de l'aspect expérimental du sujet. Ils présentent succinctement les caractéristiques physico-chimiques des fractions lourdes du pétrole et plus particulièrement des asphaltènes (complément plus détaillé en annexe 2) et exposent les résultats pour une quinzaine de bruts pétroliers et leurs coupes fractionnées (environs 50 échantillons) en solution diluée (0.1 inférieur ou égal à C inférieur ou égal à 1 % massique ) dans le toluène. Ces résultats sont ensuite comparés à ceux obtenus par spectrométrie de masse MALDI-TOF et spectrométrie 1H-RMN-FID. Dans le cas des asphaltènes, on montre une distribution des masses molaires suivant la loi de Flory-Schultz et un phénomène d'auto-association assez marqué. L'utilisation du 3e coefficient du viriel permet l'interprétation des courbes ébulliométriques non linéaires. La discussion qui suit les résultats recense avantages et inconvénients des techniques et montre leur bonne corrélation. Un soin particulier est accordé au stockage des échantillons et aux conditions opératoires qui, pour des systèmes auto-associants, influent directement sur le résultat. La conclusion générale propose des perspectives analytiques pour la mesure précise de masses molaires moyennes dans différentes conditions (T, P, solvant, concentration) et le calcul de coefficient d'activité à dilution infinie.LYON1-BU.Sciences (692662101) / SudocSudocFranceF

Comparative Ebulliometry: a Simple, Reliable Technique for Accurate Measurement of the Number Average Molecular Weight of Macromolecules. Preliminary Studies on Heavy Crude Fractions

This article is divided into two parts. In the first part, the authors present a comparison of the major techniques for the measurement of the molecular weight of macromolecules. The bibliographic results are gathered in several tables. In the second part, a comparative ebulliometer for the measurement of the number average molecular weight (Mn) of heavy crude oil fractions is described. The high efficiency of the apparatus is demonstrated with a preliminary study of atmospheric distillation residues and resins. The measurement of molecular weights up to 2000 g/mol is possible in less than 4 hours with an uncertainty of about 2%