ИНТЕЛЛЕКТУАЛЬНАЯ СИСТЕМА ПРОГНОЗИРОВАНИЯ СТРУКТУРЫ И СВОЙСТВ НАНОМАТЕРИАЛОВ

The paper presents recognition results of nanomaterial structure and sensory properties while using a developed optical «electronic eye» (e-eye) «ISON-4» and an intelligent self-learning system «ISNM» with the purpose of non-invasive fast prediction of structurе, properties and quality in respect of nanomaterial production  during their synthesis and high-precision control of micro-nanosensory device manufacturing process.Представлены результаты распознавания cтруктуры и свойств наноматериалов с использованием разработанного оптического «электронного глаза» (е-глаз) «ИСОН-4» и интеллектуальной самообучающейся системы «ИСНМ» с целью неинвазивного быстрого прогнозирования структуры, свойств и качества производства наноматериалов в процессе их синтеза, для высокоточного контроля при производстве микронаносенсорных устройств

АНАЛИЗ ДЕФЕКТОВ ПОВЕРХНОСТИ ИСХОДНЫХ ПОДЛОЖЕК АЛЮМИНИЯ И ЕГО СПЛАВОВ МЕТОДОМ СКАНИРУЮЩЕГО ЗОНДА КЕЛЬВИНА

Currently, the use of probe electrometry in non-destructive testing is constrained by the complexity of measurement results interpretation. An output signal of electrometric probe depends on a number of physical and chemical parameters of surface including chemical composition variations, stresses, dislocations, crystallographic orientation of a surface, etc. The study aims to the use of probe electrometry methods for nondestructive testing and analysis of precision metal surfaces’ defects after different treatment or processing.Control of surface defects of aluminum and its alloys was performed with a scanning Kelvin probe technique. The results of scanning were plotted in a form of contact potential difference (CPD) distribution map. Additionally, a histogram of CPD values distribution and statistical characteristics including the expectation of CPD mean value and histogram half-width were calculated either for the whole distribution or for each individual mode in a case of multimodal distribution.The spatial CPD distribution of A99 aluminum and AMG-2 alloy surfaces after electrochemical polishing and diamond finishing was studied. An additional study was held for AMG-2 surface after the formation of 30 microns thick specific nanostructured alumina oxide surface layer. Higher quality surfaces have characterized as more homogeneous distribution of the physical properties (at half-width distribution histogram). Surfaces with higher mechanical strength and overall better mechanical properties found to have lower CPD values that correspond to higher electron work function and surface energy. The presence of the second mode in the CPD distribution histogram indicates the significant proportion of defect areas on the sample surface.Analysis of visualized CPD distribution maps using defined criteria allows detecting and characterizing such defects as residual stress areas, areas with reduced microhardness, surface contamination spots, corrosion defects. This provides the possibility of rapid nondestructive testing and diagnostic of precision metal surfaces, in particular the starting substrates for sensitive elements and sensory devices manufacture. В настоящее время использование методов зондовой электрометрии в неразрушающем контроле сдерживается сложностью интерпретации результатов измерений, что связано с многофакторностью измерительного сигнала, зависящего от большого количества параметров физико-химического состояния поверхности: отклонений химического состава, механических напряжений, дислокаций, кристаллографической ориентации поверхности и др. Целью исследования являлось применение методов зондовой электрометрии для неразрушающего контроля и анализа дефектов прецизионных металлических поверхностей, полученных различными видами обработки.Методика экспериментальных исследований включала в себя построение визуализированного изображения пространственного распределения контактной разности потенциалов (КРП) по поверхности образцов методом сканирующего зонда Кельвина, построение гистограммы распределения значений КРП и определение статистических характеристик распределения, таких как математическое ожидание значений КРП и полуширина гистограммы распределения (для каждой моды при многомодальном распределении)Исследовано пространственное распределение КРП исходных подложек из алюминия А99 и сплава АМГ-2 после обработки поверхностей электрохимической полировкой и алмазным наноточением, а также после формирования на подготовленной поверхности слоя специфического наноструктурированного оксида алюминия толщиной 30 мкм. Более высоким качеством обладают поверхности, характеризующиеся меньшей полушириной гистограммы распределения. Наибольшей механической прочностью и в целом лучшими механическими свойствами при прочих равных условиях обладают поверхности с наиболее низкими значениями контактной разности потенциалов, что соответствует наибольшим значениями работы выхода электрона и поверхностной энергии. Наличие второй моды в гистограмме распределения значений контактной разности потенциалов указывает на наличие значимых по площади дефектных областей на соответствующей поверхности образца.Экспериментально показано, что анализ визуализированных изображений пространственного распределения КРП с использованием данных критериев позволяет выявлять и характеризовать такие дефекты, как места концентрации остаточных механических напряжений, участки с пониженной микротвердостью поверхности, загрязнения, коррозионные дефекты. Тем самым обеспечивается возможность оперативного неразрушающего контроля и диагностики функциональных характеристик прецизионных поверхностей металлов, в частности, исходных подложек для изготовления чувствительных элементов устройств сенсорики

ANALYSIS OF SURFACE DEFECTS OF ALUMINUM AND ITS ALLOYS WITH A SCANNING KELVIN PROBE

Currently, the use of probe electrometry in non-destructive testing is constrained by the complexity of measurement results interpretation. An output signal of electrometric probe depends on a number of physical and chemical parameters of surface including chemical composition variations, stresses, dislocations, crystallographic orientation of a surface, etc. The study aims to the use of probe electrometry methods for nondestructive testing and analysis of precision metal surfaces’ defects after different treatment or processing.Control of surface defects of aluminum and its alloys was performed with a scanning Kelvin probe technique. The results of scanning were plotted in a form of contact potential difference (CPD) distribution map. Additionally, a histogram of CPD values distribution and statistical characteristics including the expectation of CPD mean value and histogram half-width were calculated either for the whole distribution or for each individual mode in a case of multimodal distribution.The spatial CPD distribution of A99 aluminum and AMG-2 alloy surfaces after electrochemical polishing and diamond finishing was studied. An additional study was held for AMG-2 surface after the formation of 30 microns thick specific nanostructured alumina oxide surface layer. Higher quality surfaces have characterized as more homogeneous distribution of the physical properties (at half-width distribution histogram). Surfaces with higher mechanical strength and overall better mechanical properties found to have lower CPD values that correspond to higher electron work function and surface energy. The presence of the second mode in the CPD distribution histogram indicates the significant proportion of defect areas on the sample surface.Analysis of visualized CPD distribution maps using defined criteria allows detecting and characterizing such defects as residual stress areas, areas with reduced microhardness, surface contamination spots, corrosion defects. This provides the possibility of rapid nondestructive testing and diagnostic of precision metal surfaces, in particular the starting substrates for sensitive elements and sensory devices manufacture

Relationship between method of anastomosis and anastomotic failure after right hemicolectomy and ileo-caecal resection: an international snapshot audit

Aim: The anastomosis technique used following right-sided colonic resection is widely variable and may affect patient outcome. This study aimed to assess the association between leak and anastomosis technique (stapled vs handsewn). Method: This was a prospective, multicentre, international audit including patients undergoing elective or emergency right hemicolectomy or ileo-caecal resection operations over a 2-month period in early 2015. The primary outcome measure was the presence of anastomotic leak within 30 days of surgery, determined using a prespecified definition. Mixed effects logistic regression models were used to assess the association between leak and anastomosis method, adjusting for patient, disease and operative cofactors, with centre included as a random-effect variable. Results: This study included 3208 patients, of whom 78.4% (n = 2515) underwent surgery for malignancy and 11.7% (n = 375) underwent surgery for Crohn's disease. An anastomosis was performed in 94.8% (n = 3041) of patients, which was handsewn in 38.9% (n = 1183) and stapled in 61.1% (n = 1858). Patients undergoing handsewn anastomosis were more likely to be emergency admissions (20.5% handsewn vs 12.9% stapled) and to undergo open surgery (54.7% handsewn vs 36.6% stapled). The overall anastomotic leak rate was 8.1% (245/3041), which was similar following handsewn (7.4%) and stapled (8.5%) techniques (P = 0.3). After adjustment for cofactors, the odds of a leak were higher for stapled anastomosis (adjusted OR = 1.43; 95% CI: 1.04–1.95; P = 0.03). Conclusion: Despite being used in lower-risk patients, stapled anastomosis was associated with an increased anastomotic leak rate in this observational study. Further research is needed to define patient groups in whom a stapled anastomosis is safe

Patients with Crohn's disease have longer post-operative in-hospital stay than patients with colon cancer but no difference in complications' rate

BACKGROUNDRight hemicolectomy or ileocecal resection are used to treat benign conditions like Crohn's disease (CD) and malignant ones like colon cancer (CC).AIMTo investigate differences in pre- and peri-operative factors and their impact on post-operative outcome in patients with CC and CD.METHODSThis is a sub-group analysis of the European Society of Coloproctology's prospective, multi-centre snapshot audit. Adult patients with CC and CD undergoing right hemicolectomy or ileocecal resection were included. Primary outcome measure was 30-d post-operative complications. Secondary outcome measures were post-operative length of stay (LOS) at and readmission.RESULTSThree hundred and seventy-five patients with CD and 2,515 patients with CC were included. Patients with CD were younger (median = 37 years for CD and 71 years for CC (P < 0.01), had lower American Society of Anesthesiology score (ASA) grade (P < 0.01) and less comorbidity (P < 0.01), but were more likely to be current smokers (P < 0.01). Patients with CD were more frequently operated on by colorectal surgeons (P < 0.01) and frequently underwent ileocecal resection (P < 0.01) with higher rate of de-functioning/primary stoma construction (P < 0.01). Thirty-day post-operative mortality occurred exclusively in the CC group (66/2515, 2.3%). In multivariate analyses, the risk of post-operative complications was similar in the two groups (OR 0.80, 95%CI: 0.54-1.17; P = 0.25). Patients with CD had a significantly longer LOS (Geometric mean 0.87, 95%CI: 0.79-0.95; P < 0.01). There was no difference in re-admission rates. The audit did not collect data on post-operative enhanced recovery protocols that are implemented in the different participating centers.CONCLUSIONPatients with CD were younger, with lower ASA grade, less comorbidity, operated on by experienced surgeons and underwent less radical resection but had a longer LOS than patients with CC although complication's rate was not different between the two groups

Predictors for anastomotic leak, postoperative complications, and mortality after right colectomy for cancer: Results from an international snapshot audit

Background: A right hemicolectomy is among the most commonly performed operations for colon cancer, but modern high-quality, multination data addressing the morbidity and mortality rates are lacking. Objective: This study reports the morbidity and mortality rates for right-sided colon cancer and identifies predictors for unfavorable short-term outcome after right hemicolectomy. Design: This was a snapshot observational prospective study. Setting: The study was conducted as a multicenter international study. Patients: The 2015 European Society of Coloproctology snapshot study was a prospective multicenter international series that included all patients undergoing elective or emergency right hemicolectomy or ileocecal resection over a 2-month period in early 2015. This is a subanalysis of the colon cancer cohort of patients. Main Outcome Measures: Predictors for anastomotic leak and 30-day postoperative morbidity and mortality were assessed using multivariable mixed-effect logistic regression models after variables selection with the Lasso method. Results: Of the 2515 included patients, an anastomosis was performed in 97.2% (n = 2444), handsewn in 38.5% (n = 940) and stapled in 61.5% (n = 1504) cases. The overall anastomotic leak rate was 7.4% (180/2444), 30-day morbidity was 38.0% (n = 956), and mortality was 2.6% (n = 66). Patients with anastomotic leak had a significantly increased mortality rate (10.6% vs 1.6% no-leak patients; p ≥ 0.001). At multivariable analysis the following variables were associated with anastomotic leak: longer duration of surgery (OR = 1.007 per min; p = 0.0037), open approach (OR = 1.9; p = 0.0037), and stapled anastomosis (OR = 1.5; p = 0.041). Limitations: This is an observational study, and therefore selection bias could be present. For this reason, a multivariable logistic regression model was performed, trying to correct possible confounding factors. Conclusions: Anastomotic leak after oncologic right hemicolectomy is a frequent complication, and it is associated with increased mortality. The key contributing surgical factors for anastomotic leak were anastomotic technique, surgical approach, and duration of surgery

Surgeons' fear of getting infected by COVID19: A global survey.

Surgeons' fear of getting infected by COVID19: A global surve