Застосування рівняння Віганда–Снайдера до термодинамічної інтерпретації високоеластичної деформації гладеньких м'язів шлунка

Iз застосуванням рiвняння Вiганда–Снайдера здiйснено термодинамiчний аналiз високоеластичної деформацiї (Δl) кiльцевих гладеньких м’язiв антрального вiддiлу шлунка щурiв. Показано, що малi (Δl/l0 ≈ 20%) розтягування гладеньком’язових смужок шлунка щурiв (дiапазон температур 22–48 °С) не супроводжуються змiнами у впорядкованостi тензометричної системи (ΔS = 0). Такий самий феномен маємо i у випадку значних розтягувань (Δl/l0 ≈ 50%), але у бiльш вузькому дiапазонi температур: понад 30 °С i менше 40 °С. При великих розтягуваннях гладеньком’язових смужок шлунка (Δl/l0 ≈ 50%) як при вiдносно низьких (22–30 °С), так i при вiдносно високих (понад 37 °С) температурах мають мiсце iстотнi структурнi змiни в тензометричнiй системi. За цих умов спостерiгається iнверсiя знаку ентропiйних ефектiв: ΔS > 0 при T 37 °С. Обговорюється зв’язок мiж виявленими термодинамiчними ефектами i фiзiологiчними механiзмами регуляцiї функцiонування травного тракту.Применение уравнения Виганда–Снайдера проведен термодинамический анализ высокоэластичной деформации кольцевых гладких мышц антрального отдела желудка крыс. Показано, что малые (Δl/l0 ≈ 20%) растягивания гладкомышечных полосок желудка крыс (диапазон температур 22–48 °С) не сопровождаются изменениями в упорядоченности тензометрической системы (ΔS = 0). Такой же феномен наблюдается и при значительных растягиваниях (Δl/l0 ≈ 50%), но в более узком диапазоне температур: выше 30 °С и ниже 40 °С. При больших растяжениях гладкомышечных полосок желудка (Δl/l0 ≈ 50%) как при относительно низких (22–30 °С), так и при относительно высоких (выше 37 °С) температурах имеют место существенные структурные изменения в тензометрической системе. В этих условиях наблюдается инверсия знака энтропийных эффектов: ΔS > 0 при T 37 °С. Обсуждается связь между выявленными термодинамическими эффектами и физиологическими механизмами регуляции функционирования пищеварительного тракта.With using the Wiegand–Snyder equation, the thermodynamic analysis of a viscoelastic deformation of circular smooth muscle strips of rat’s stomach (antral part) is performed. It is shown that a small (Δl/l0 ≈ 20%) stretch of rat stomach smooth muscle strips (temperature range 22–48 °С) is not accompanied by changes in the ordering of the tensometric system (ΔS = 0). The same phenomenon is observed with a considerable stretching (Δl/l0 ≈ 50%), but in a narrower tempera- ture range: above 30 °C and below 40 °C. For large strains, gastric smooth muscle strips (Δl/l0 ≈ 50%) at relatively low (22–30 °C) and at relatively high (above 37 °C) temperatures undergo substantial structural changes in the ordering of the tensometric system. Under these conditions, there is the inversion of the sign of entropy effects: ΔS > 0 at temperatures below 31 °C and ΔS < 0 at temperatures above 37 °C. The relation between the identified thermodynamic effects and the physiological mechanisms of regulation of the functioning of the digestive tract is discussed

Non-adiabatic corrections to elastic scattering of halo nuclei

We derive the formalism for the leading order corrections to the adiabatic approximation to the scattering of composite projectiles. Assuming a two-body projectile of core plus loosely-bound valence particle and a model (the core recoil model) in which the interaction of the valence particle and the target can be neglected, we derive the non-adiabatic correction terms both exactly, using a partial wave analysis, and using the eikonal approximation. Along with the expected energy dependence of the corrections, there is also a strong dependence on the valence-to-core mass ratio and on the strength of the imaginary potential for the core-target interaction, which relates to absorption of the core in its scattering by the target. The strength and diffuseness of the core-target potential also determine the size of the corrections. The first order non-adiabatic corrections were found to be smaller than qualitative estimates would expect. The large absorption associated with the core-target interaction in such halo nuclei as Be11 kills off most of the non-adiabatic corrections. We give an improved estimate for the range of validity of the adiabatic approximation when the valence-target interaction is neglected, which includes the effect of core absorption. Some consideration was given to the validity of the eikonal approximation in our calculations.Comment: 14 pages with 10 figures, REVTeX4, AMS-LaTeX v2.13, submitted to Phys. Rev.

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype