Realization of wavelength conversion with hyperbolic secant femtosecond pulse in normal dispersion regime

Realization of wavelength conversion based on second-order femtosecond dark solitons with hyperbolic secant pulse is presented. This is achieved by introducing localized dispersion perturbation along the optical fiber. We demonstrate that an initial 30 fs second-order pulse decays to similar sub-pulses by applying perturbation using a step increment of β2 from 6.3 to 15.75 ps2 km-1. This shows that the realization of a 12 channel wavelength converter for femtosecond pulses is possible. Recent research shows the possibility of realizing wavelength conversion generated from picosecond solitons neglecting nonlinear effects. However, employing the same method for femtosecond pulses fails due to the manifestation of nonlinear effects. In this paper, pulse deformation under different levels of perturbation was tested, and appropriate perturbation leading to similar sub-pulses is achieved

Virtual cellular manufacturing system based on resource element approach and analyzing its performance over different basic layouts

This research aims to present how choosing a suitable layout can improve the performance of virtual cellular manufacturing systems (VCMSs), especially minimizing the material flow between machines required by each family group. To present the efficacy of basic layouts on performances of VCMSs, a multi-objective mathematical model with a goal programming (GP) approach is developed to generate VCMSs based on resource-elements (REs). The formulated model is coded in Lingo software and is run over functional and distributed arrangements of the same machines. The performance and the validity of the developed model are checked by a numerical example taken from the literature. The objective function of the mathematical model is measured for that example over two mentioned layout to compare the performance of the generated systems. Moreover, because of the material handling costs importance, material flows are measured to find the best option as a basic layout for VCMSs. To compare the performance of the generated system with the classical cellular manufacturing system (CMS), cell capacity utilization (CCU) is employed as an independent criterion to evaluate each system. The result illustrates the priority of distributed layouts for generating RE-based VCMSs because of its flexibility, minimizing the objective function for the mathematical model, and smaller material flow by the components. In addition, the generated VCMSs outperforms the classical CMS from the CCU point of view

Evaluation of the prevalence and clinical and laboratory features of acute viral myositis in children with influenza referred to the emergency department of Ali Asghar Tehran Hospital in 2019 and 2020

Introduction: Influenza-related viral myositis is observed mostly in children with influenza, and the disease is more common in influenza type B. The aim of the present study was to evaluate the prevalence, and clinical and laboratory features of acute viral myositis in children with influenza in 2019 and 2020. Methods: This retrospective cross-sectional study was performed in Ali Asghar Hospital, from December 2019 to February 2020. Children aged 2–14 years with symptoms of acute onset of fever, along with the symptoms of influenza with or without muscle pain who referred to the emergency department of Hazrat Ali Asghar Children's Hospital, were included in the study. The data were collected and analyzed by Statistical Package for the Social Sciences (SPSS) version 22. Results: Out of the 105 participants in this study, 62 (59%) were male and the rest were female. The average age of the patients was 5.34 years (SD = 2.63). Clinical signs of lower limb pain, myalgia, lameness, weakness, and lethargy were significantly more common in patients with myositis (P-value < 0.05). In-vitro examination demonstrated that creatine phosphokinase (CPK), aspartate aminotransferase (AST), and aAlanine aminotransferease (ALT) levels were significantly higher in patients with myositis. Conclusion: Based on the present results, the clinical symptoms in patients are quite clear, and based on the symptoms, it is possible to diagnose and treat myositis without relying on laboratory findings; due to the self-limitation of this complication and lack of the need for complex treatments in case of early diagnosis, physicians can diagnose and treat many cases, depending on the clinical symptoms and the accuracy of the examination

Scheduling Operations and SMED: Complementary Ways to Improve Productivity

In most real cases the problem of scheduling operations are sequence de-pendent, that is, the setup time depends on the sequencing of tasks/batches in the ma-chine. Given the current industrial manufacturing trends and requirements such as high variability, customization and reduction of product life cycles, organizations seek to implement new methodologies to adapt and respond with more flexibly to new demands of the global markets. Thus, this work sought to analyse, inspired by a real case of the textile industry, how production scheduling can be understood as a complement to SMED in order to achieve productivity improvement. In the case under analysis we presented the problem of scheduling tasks in uniform parallel machines with sequence-dependent setup times. The main objective of this work was to minimize the total pro-duction time. To this goal, optimization heuristics were used, in this case, simulated annealing algorithm, that demonstrated how the use of heuristics can be an advantage to reduce setup times when associated with other methodologies such as SMED.This work has been supported by the project Centro-01-0145-FEDER-000017 - EMaDeS - Energy, Materials and Sustainable Development, co-financed by the Portugal 2020 Program (PT 2020), within the Regional Operational Program of the Center (CENTRO 2020) and the Euro pean Union through the European Regional Development Fund (ERDF).The authors wish to thank the opportunity and financial support that permitted to carry on this project. And C-MAST/ Centre for Mechanical and Aerospace Science and Technologies. project UID / EMS / 00151/2013 C-MAST, POCI-01-0145-FEDER-007718.info:eu-repo/semantics/publishedVersio

The impact of sofosbuvir/daclatasvir or ribavirin in patients with severe COVID-19

OBJECTIVES: Sofosbuvir and daclatasvir are direct-acting antivirals highly effective against hepatitis C virus. There is some in silico and in vitro evidence that suggests these agents may also be effective against SARS-CoV-2. This trial evaluated the effectiveness of sofosbuvir in combination with daclatasvir in treating patients with COVID-19. METHODS: Patients with a positive nasopharyngeal swab for SARS-CoV-2 on RT-PCR or bilateral multi-lobar ground-glass opacity on their chest CT and signs of severe COVID-19 were included. Subjects were divided into two arms with one arm receiving ribavirin and the other receiving sofosbuvir/daclatasvir. All participants also received the recommended national standard treatment which, at that time, was lopinavir/ritonavir and single-dose hydroxychloroquine. The primary endpoint was time from starting the medication until discharge from hospital with secondary endpoints of duration of ICU stay and mortality. RESULTS: Sixty-two subjects met the inclusion criteria, with 35 enrolled in the sofosbuvir/daclatasvir arm and 27 in the ribavirin arm. The median duration of stay was 5 days for the sofosbuvir/daclatasvir group and 9 days for the ribavirin group. The mortality in the sofosbuvir/daclatasvir group was 2/35 (6%) and 9/27 (33%) for the ribavirin group. The relative risk of death for patients treated with sofosbuvir/daclatasvir was 0.17 (95% CI 0.04-0.73, P = 0.02) and the number needed to treat for benefit was 3.6 (95% CI 2.1-12.1, P < 0.01). CONCLUSIONS: Given these encouraging initial results, and the current lack of treatments proven to decrease mortality in COVID-19, further investigation in larger-scale trials seems warranted