Computer Test of a Modified Silicene/Graphite Anode for Lithium-Ion Batteries

Despite the considerable efforts made to use silicon anodes and composites based on them in lithium-ion batteries, it is still not possible to overcome the difficulties associated with low conductivity, a decrease in the bulk energy density, and side reactions. In the present work, a new design of an electrochemical cell, whose anode is made in the form of silicene on a graphite substrate, is presented. The whole system was subjected to transmutation neutron doping. The molecular dynamics method was used to study the intercalation and deintercalation of lithium in a phosphorus-doped silicene channel. The maximum uniform filling of the channel with lithium is achieved at 3% and 6% P-doping of silicene. The high mobility of Li atoms in the channel creates the prerequisites for the fast charging of the battery. The method of statistical geometry revealed the irregular nature of the packing of lithium atoms in the channel. Stresses in the channel walls arising during its maximum filling with lithium are significantly inferior to the tensile strength even in the presence of polyvacancies in doped silicene. The proposed design of the electrochemical cell is safe to operate. Copyright © 2020 American Chemical Society

Computational study of lithium intercalation in silicene channels on a carbon substrate after nuclear transmutation doping

Silicene is considered to be the most promising anode material for lithium-ion batteries. In this work, we show that transmutation doping makes silicene substantially more suitable for use as an anode material. Pristine and modified bilayer silicene was simulated on a graphite substrate using the classical molecular dynamics method. The parameters of Morse potentials for alloying elements were determined using quantum mechanical calculations. The main advantage of modified silicene is its low deformability during lithium intercalation and its possibility of obtaining a significantly higher battery charge capacity. Horizontal and vertical profiles of the density of lithium as well as distributions of the most significant stresses in the walls of the channels were calculated both in undoped and doped systems with different gaps in silicene channels. The energies of lithium adsorption on silicene, including phosphorus-doped silicene, were determined. High values of the self-diffusion coefficient of lithium atoms in the silicene channels were obtained, which ensured a high cycling rate. The calculations showed that such doping increased the normal stress on the walls of the channel filled with lithium to 67% but did not provoke a loss of mechanical strength. In addition, doping achieved a greater battery capacity and higher charging/discharging rates. © 2020 by the authors.Russian Science Foundation, RSF: 16-13-00061Funding: This work was supported by the Russian Science Foundation (grant number 16-13-00061)

Hambatan Pelaksanaan Kriteria Ketuntasan Minimal Mata Pelajaran Produktif Tata Busana SMKN 1 Lembah Gumanti

This study aims to describe the implementation of Productive KKM dressmaking courses in SMKN 1 Gumanti Valley, in terms of the criteria for determining the KKM intake (student ability), complexity (difficulty level indicator), and carrying capacity. This research is qualitative research. Subject and informant research is Professor Earning dressmaking, amounting to 5 (five) people. Data collection techniques are observation, interviews, documentation, and triangulation. Data processing techniques are data collection, data reduction, data display, and conclusion. The results of this study indicate the general implementation of the Productive subjects KKM dressmaking, where teachers are still having difficulty, namely the intake criteria (student ability), On the criteria of complexity where teachers are difficult to adjust the complexity of the material with the ability of students. As well as carrying on the criteria, lack of educational infrastructure that supports the learning process, and the number of teachers earning dressmaking that do not meet the ideal standards

Computational characterization of novel nanostructured materials: A case study of NiCl2_2

A computational approach combining dispersion-corrected density functional theory (DFT) and classical molecular dynamics is employed to characterize the geometrical and thermo-mechanical properties of a recently proposed 2D transition metal dihalide NiCl$_2$. The characterization is performed using a classical interatomic force field whose parameters are determined and verified through the comparison with the results of DFT calculations. The developed force field is used to study the mechanical response, thermal stability, and melting of a NiCl$_2$ monolayer on the atomistic level of detail. The 2D NiCl$_2$ sheet is found to be thermally stable at temperatures below its melting point of ~695 K. At higher temperatures, several subsequent structural transformations of NiCl$_2$ are observed, namely a transition into a porous 2D sheet and a 1D nanowire. The computational methodology presented through the case study of NiCl$_2$ can also be utilized to characterize other novel 2D materials, including recently synthesized NiO$_2$, NiS$_2$, and NiSe$_2$

Perioperative pharmacokinetic-guided factor VIII concentrate dosing in haemophilia (OPTI-CLOT trial):an open-label, multicentre, randomised, controlled trial

Background Dosing of replacement therapy with factor VIII concentrate in patients with haemophilia A in the perioperative setting is challenging. Underdosing and overdosing of factor VIII concentrate should be avoided to minimise risk of perioperative bleeding and treatment costs. We hypothesised that dosing of factor VIII concentrate on the basis of a patient's pharmacokinetic profile instead of bodyweight, which is standard treatment, would reduce factor VIII consumption and improve the accuracy of attained factor VIII levels. Methods In this open-label, multicentre, randomised, controlled trial (OPTI-CLOT), patients were recruited from nine centres in Rotterdam, Groningen, Utrecht, Nijmegen, The Hague, Leiden, Amsterdam, Eindhoven, and Maastricht in The Netherlands. Eligible patients were aged 12 years or older with severe or moderate haemophilia A (severe haemophilia was defined as factor VIII concentrations of Findings Between May 1, 2014, and March 1, 2020, 98 patients were assessed for eligibility and 66 were enrolled in the trial and randomly assigned to the pharmacokinetic-guided treatment group (34 [52%]) or the standard treatment group (32 [48%]). Median age was 49.1 years (IQR 35.0 to 62.1) and all participants were male. No difference was seen in consumption of factor VIII concentrate during the perioperative period between groups (mean consumption of 365 IU/kg [SD 202] in pharmacokinetic-guided treatment group vs 379 IU/kg [202] in standard treatment group; adjusted difference -6 IU/kg [95% CI -88 to 100]). Postoperative bleeding occurred in six (18%) of 34 patients in the pharmacokinetic-guided treatment group and three (9%) of 32 in the standard treatment group. One grade 4 postoperative bleeding event occurred, which was in one (3%) patient in the standard treatment group. No treatment-related deaths occurred. Interpretation Although perioperative pharmacokinetic-guided dosing is safe, it leads to similar perioperative factor VIII consumption when compared with standard treatment. However, pharmacokinetic-guided dosing showed an improvement in obtaining factor VIII concentrations within the desired perioperative factor VIII range. These findings provide support to further investigation of pharmacokinetic-guided dosing in perioperative haemophilia care. Copyright (C) 2021 Elsevier Ltd. All rights reserved

Paradox: Does liver insuffi ciency protect the patient? A hypothesis

Despite the fact that the key role of the liver in the formation of the immune response to injury is not in doubt, the mechanisms of weakening the immune response to infectious and noninfectious lesions in patients with hepatic failure remain unclear. We propose an original hypothesis of forming the ways to limit the amplitude of the systemic inflammatory response in patients with the end-stage liver disease. The basis of the hypothesis is the idea that as a result of reducing the intensity of the natural stimulation of membrane mCD14 receptors by the ligands of infectious nature, the basic mechanism of the systemic immune response induction by liver macrophages (Kupffer cells) is interrupted. According to the proposed hypothesis, in condition of liver failure, the synthesis of lipopolysaccharide-binding protein by hepatocytes is reduced. This leads to a decreased amplitude and intensity of the protective immune responses. This fact explains a number of clinical phenomena observed in patients with liver failure/dysfunction that consist in a reduced reactivity of the organism to the damage inflicted by infectious and noninfectious agents. The authors consider it possible to use this hypothesis in the search for new trends to prevent the immune system hyper-reactivity in sepsis, and to improve the therapeutic strategies for the management of patients at high risk of infectious complications after liver transplantation

СРАВНИТЕЛЬНАЯ ОЦЕНКА СИМПАТИЧЕСКОЙ БЛОКАДЫ ПРИ ГРУДНОЙ ЭПИДУРАЛЬНОЙ И БИЛАТЕРАЛЬНОЙ ПАРАВЕРТЕБРАЛЬНОЙ АНЕСТЕЗИЯХ ПРИ ОПЕРАЦИЯХ ВЫСОКОЙ ТРАВМАТИЧНОСТИ НА ОРГАНАХ ВЕРХНЕГО ЭТАЖА БРЮШНОЙ ПОЛОСТИ

Objective: to compare the degree of sympathetic blockade caused by thoracic epidural or bilateral paravertebral anesthesia. Superior mesenteric artery blood flow was measured calculating the coefficient of flow resistance (resistance index) as an indicator of the degree of sympathetic block in patients undergoing high-traumaticity operations on the upper abdominal organs under thoracic epidural or bilateral paravertebral anesthesia. The patients of both groups were noted to develop sympathetic blockade with a statistically significant reduction in vascular resistance (resistance index) of the superior mesenteric artery and with an increase in blood flow in the visceral bed. The degree of sympathetic blockade was statistically significantly higher in patients under epidural anesthesia. Conclusion. Bilateral thoracic paravertebral blockade decreases sympathetic nervous system activation and may be used during high-traumaticity surgery if there are existing or predictable contraindications to epidural anesthesia. Цель исследования - сравнение выраженности симпатической блокады, обусловленной грудной эпидуральной или билатеральной паравертебральной анестезией. Проведены измерения кровотока по верхней брыжеечной артерии с расчётом коэффициента сопротивления потоку (индекса резис­тентности) как показателя выраженности симпатического блока у пациентов, которым выполняли высокотравматичные операции на органах верхнего этажа брюшной полости в условиях грудной эпидуральной или билатеральной паравертебральной анестезии. У пациентов обеих групп отмечались развитие симпатической блокады со статистически значимым снижением сосудистого сопротивления (индекса резистентности) верхней брыжеечной артерии и увеличение кровотока в висцеральном бассейне. Выраженность симпатической блокады была статистически значимо выше у пациентов с эпидуральной анестезией. Заключение. Билатеральная грудная паравертебральная блокада снижает активацию симпатичес­кой нервной системы и может быть применена при выполнении оперативных вмешательств высокой травматичности при имеющихся или прогнозируемых противопоказаниях к проведению эпидуральной анестезии