Generalized SEIR Epidemic Model for COVID-19 in a Multipatch Environment

In this paper, an n -patch SEIR epidemic model for the coronavirus disease 2019 (COVID-19) is presented. It is shown that there is unique disease-free equilibrium for this model. Then, the dynamic behavior is studied by the basic reproduction number. The transmission of COVID-19 is fitted based on actual data. The influence of quarantined rate and population migration rate on the spread of COVID-19 is also discussed by simulation.

Fishing line assisted endoscopic placement of multiple plastic biliary stents for unresectable malignant hilar biliary obstruction: a retrospective study

Background and aims Stent migration is one of the most common complications during the placement of multiple plastic biliary stents (MPBS) under endoscopy. This study aims to evaluate the feasibility and efficiency of the fishing line assisted (FLA) method for preventing the complication. Methods Patients with unresectable malignant hilar biliary obstruction (MHBO) who undergone endoscopic placement of MPBS using the FLA or conventional method from May 2018 to April 2021 in our center were enrolled in the study. The endpoints of this study were the stent migration rate, technical success rates, adverse events rates, times of stent migration, and the procedure time. Results FLA group (N = 19) and conventional group (N = 22) had similar baseline characteristics of the patients. The technical success rates (100% vs. 95.5%; P > 0.05), ERCP-related adverse events rates (5.3% vs. 4.5%; P > 0.05), and the stent-related adverse events rates (0% vs. 4.5%; P > 0.05) were no significant differences between the FLA and conventional groups. MPBS inserted using the conventional method consumed more time (median, 33.9 min vs. 15.6 min; P < 0.05) method and increased the times of stent migration (median, 3 times vs. 0 times; P < 0.05) than using the FLA method. Even if no statistical difference was detected in the stent migration rate between groups, this rate was lower in the FLA group than the conventional group (0% vs. 13.6%; P > 0.05). Conclusions FLA method is an effective technique for MPBS implantation to prevent stent migration during endoscopic retrograde cholangiography (ERCP). The method should be applied to patients with unresectable MHBO who need to place MPBS.

Country-Specific Magnitudes of Migration between Rural and Urban Sectors

Across seventy-four countries, six migration propensities of men and women are tabulated in this chapter: notably, for gross and net, lifetime and five-year flow, rural-urban and urban-rural moves. China is purported to have the highest rate of rural-urban migration in recent history, but neither reliable estimates nor sufficient data to permit computations appear to be available. The conventional wisdom is that India has a low rural-urban migration rate, but our estimates contradict this claim. The five-year flow rates are only loosely correlated with lifetime movements. It is important to understand the situation in each country at the time of enumeration, and these specific circumstances are described in the second half of the chapter. Gross rural-urban migration rates increase at higher urbanization levels, but net rural-urban migration proves positive virtually everywhere. Yet a decomposition for twenty-two countries indicates that reclassification of rural areas as urban is far more important than net rural-urban moves in incremental urbanization.

The influence of the type of nut raw materials on the processes of migration of fats in glazed candies with pralin bodies

Целью исследования являлось изучение влияния свойств орехового сырья на направление и скорость процессов миграции жиров в глазированных конфетах с пралиновыми корпусами. Исследование процессов миграции жиров между корпусом и глазурью в процессе хранения необходимо для прогнозирования сохранности и предотвращения органо-лептической порчи в результате осветления или умягчения глазури, а также «поседения» поверхности изделий. Предложен подход прогнозирования скорости процессов миграции жиров при хранении конфет с корпусами, изготовленными на основе орехового сырья, с использованием удельной скорости миграции жиров. Исследованы процессы миграции жиров в модельных образцах конфет с пралиновыми корпусами на основе арахиса, фундука, кешью, миндаля, покрытых глазурью с использованием заменителя масла какао лауринового типа при температуре хранения 18 °С. Показано, что удельная скорость миграции олеиновой кислоты на поверхность модельных образцов глазированных конфет с корпусами на основе арахиса превышает скорость миграции в конфетах с корпусами на основе кешью приблизительно в 20 раз. Полученные закономерности позволяют установить дополнительные требования к качеству используемого жирового сырья для уменьшения скорости миграции жиров. The aim of the work - the investigation of the influence of nut raw material properties on the direction and speed of fat migration processes in glazed sweets with praline cases. The study of fat migration processes between the body and the glaze during storage is necessary to predict the safety and prevent organoleptic spoilage as a result of lightening or softening of the glaze, as well as «graying» of the surface of the products. An approach to predicting the rate of fat migration processes during the storage of sweets with cases made on the basis of nut raw materials using the specific rate of fat migration is proposed. The processes of fat migration in model samples of sweets with praline cases based on peanuts, hazelnuts, cashews, almonds, glazed with glaze, with the use of a lauric-type cocoa butter substitute were investigated at a storage temperature of 18 °C. It is shown that the specific rate of migration of oleic acid to the surface of model samples of glazed sweets with peanut-based cases exceeds the migration rate in sweets with cashew-based cases by approximately 20 times. The obtained regularities allow us to establish additional requirements for the quality of the fat raw materials used to reduce the rate of fat migration.

Giant meandering channel evolution, Campos deep-water salt basin, Brazil

Submarine channels are conduits for sediment delivery to continental margins, and channel deposits can be sandy components of the fill in tectonically active salt basins. Examples of salt-withdrawal basin fill commonly show successions of sandy channelized or sheet-like systems alternating with more mud-rich mass-transport complexes and hemipelagites. This alternation of depositional styles is controlled by subsidence and sediment-supply histories. Salt-basin fill comprising successions of largely uninterrupted meandering-channel deposition are less commonly recognized. This begs the questions: can sediment supply be large enough to overwhelm basin subsidence and result in a thick succession of channel deposits, and, if so, how would such a channel system evolve? Here, we use three-dimensional seismic-reflection data from a &gt;1500 km2 region with salt-influenced topography in the Campos Basin, offshore Brazil, to evaluate the influence of salt diapirs on an Upper Cretaceous–Paleogene giant meandering submarine-channel system (channel elements &gt;1 km wide; meander wavelengths several kilometers to &gt;10 km). The large scale of the channels in the Campos Basin suggests that sediment discharge was large enough to sustain the meandering channel system in spite of large variability in subsidence across the region. We interpreted 22 channel centerlines to reconstruct the detailed kinematic evolution of this depositional system; this level of detail is akin to that of recent studies of meandering fluvial channels in time-lapse Landsat satellite images. The oldest channel elements are farther from salt diapirs than many of the younger ones; the centerlines of the older channel elements exhibit a correlation between curvature and migration rate, and a spatial delay between locations of peak curvature and maximum migration distance, similar to that observed in rivers. As many of the younger channel centerlines expanded toward nearby salt diapirs, their migration pattern switched to downstream translation as a result of partial confinement. Channel segments that docked against salt diapirs became less mobile, and, as a result, they do not show a correlation between curvature and migration rate. The channel migration pattern in the Campos Basin is different compared to that of a tectonically quiescent continental rise where meander evolution is unobstructed. This style of channelized basin filling is different from that of many existing examples of salt-withdrawal minibasins that are dominated by overall less-channelized deposits. This difference might be a result of the delivery of voluminous coarse sediment and high discharge of channel-forming turbidity currents to the Campos Basin from rivers draining actively uplifting coastal mountains of southeastern Brazil. Detailed kinematic analysis of such well-preserved channels can be used to reconstruct the impact of structural deformation on basin fill.

Risk Factors for Progression of Chronic Kidney Disease With Glomerular Etiology in Hospitalized Children

Aim: To Identify association between risk factors to Chronic kidney disease (CKD) stage 5 in children with glomerular diseases in children in China.Methods: The Hospital Quality Monitoring System database was used to extract data for the study cohort. The primary outcome included progression to CKD stage 5 or dialysis. Cox regression was used to assess potential risk factors. Patients with lower stages (CKD stage 1 and 2) and higher stages (CKD stage 3 and 4) at baseline were analyzed separately.Results: Of 819 patients (4,089 hospitalization records), 172 (21.0%) patients reached the primary outcome during a median followed-up of 11.4 months. In the lower stages group, factors associated with the primary outcome included older age [Hazard Ratio (HR), 1.21; 95% confidence interval (CI), 1.10–1.34] and out-of-pocket payment (HR, 4.14; 95% CI, 1.57–10.95). In the higher stages group, factors associated with the primary outcome included CKD stage 4 (HR, 2.31; 95% CI, 1.48–3.62) and hypertension (HR, 1.99; 95% CI, 1.29–3.07). The medical migration rate was 38.2% in this study population.Conclusion: There are different risk factors for progression to the primary outcome in different stages in CKD with glomerular etiology. Further prospective studies are needed to assess these risk factors. The high medical migration rate reflected the regional disparities in the accessibility of pediatric kidney care between regions.