Global impact of COVID-19 on stroke care and IV thrombolysis

Objective To measure the global impact of COVID-19 pandemic on volumes of IV thrombolysis (IVT), IVT transfers, and stroke hospitalizations over 4 months at the height of the pandemic (March 1 to June 30, 2020) compared with 2 control 4-month periods. Methods We conducted a cross-sectional, observational, retrospective study across 6 continents, 70 countries, and 457 stroke centers. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases. Results There were 91,373 stroke admissions in the 4 months immediately before compared to 80,894 admissions during the pandemic months, representing an 11.5% (95% confidence interval [CI] -11.7 to -11.3, p < 0.0001) decline. There were 13,334 IVT therapies in the 4 months preceding compared to 11,570 procedures during the pandemic, representing a 13.2% (95% CI -13.8 to -12.7, p < 0.0001) drop. Interfacility IVT transfers decreased from 1,337 to 1,178, or an 11.9% decrease (95% CI -13.7 to -10.3, p = 0.001). Recovery of stroke hospitalization volume (9.5%, 95% CI 9.2-9.8, p < 0.0001) was noted over the 2 later (May, June) vs the 2 earlier (March, April) pandemic months. There was a 1.48% stroke rate across 119,967 COVID-19 hospitalizations. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was noted in 3.3% (1,722/52,026) of all stroke admissions. Conclusions The COVID-19 pandemic was associated with a global decline in the volume of stroke hospitalizations, IVT, and interfacility IVT transfers. Primary stroke centers and centers with higher COVID-19 inpatient volumes experienced steeper declines. Recovery of stroke hospitalization was noted in the later pandemic months.Paroxysmal Cerebral Disorder

A clustering-based repair shop design for repairable spare part supply systems

In this study, we address the design problem of a single repair shop in a repairable multi-item spare part supply system. We propose a sequential solution heuristic to solve the joint problem of resource pooling, inventory allocation, and capacity level designation of the repair shop with stochastic failure and repair time of repairables. The pooling strategies to obtain repair shop clusters/cells are handled by a K-median algorithm by taking into account the repair time and the holding cost of each repairable spare part. We find that the decomposition of the repair shop in sub-systems by clustering reduces the complexity of the problem and enables the use of queue-theoretical approximations to optimize the inventory and capacity levels. The effectiveness of the proposed approach is analyzed with several numerical experiments. The repair shop designs suggested by the approach provide around 10% and 30% cost reductions on an average when compared to fully flexible and totally dedicated designs, respectively. We also explore the impact of several input parameters and different clustering rules on the performance of the methodology and provide managerial insights.Scopu

Evaluation of androgen-dependent skin findings of polycystic ovary syndrome (PCOS)

Aim: The purpose of the study was to investigate the biochemical and metabolic abnormalities related to the cutaneous characteristics of PCOS. Material–Methods: Patients diagnosed with PCOS were included in the study. Demographic data and accompanying androgen-dependent skin findings (acne, seborrhea, androgenic alopecia, acanthosis nigricans, skin tag, and hirsutism) were recorded. The free testosterone, total testosterone, dehydroepiandrosterone sulfate, androstenedione,17-Hidroksi progesterone, sex hormone binding globulin, prolactin, fasting glucose, fasting insulin, HbA1C, HDL, and triglycerides, follicle-stimulating hormone, luteinized hormone, free androgen index, and HOMA-IR levels of the patients were measured. The hormonal values of the patients with PCOS with and without skin findings were compared. Results: The HOMA-IR values of the acanthosis nigricans (+) PCOS group were significantly higher than the acanthosis nigricans (–) PCOS group (p <.001). The DHEA-SO4, FAI, and FI values of patients with hirsutism (HR) (+) PCOS were found to be statistically higher than patients with HR (–) PCOS (p =.006, p =.015, p =.004). Conclusion: PCOS is among the most common endocrine disorders of women of reproductive age and was associated with some hormonal, metabolic, and skin findings. Certain androgenic and metabolic variables developing in PCOS might correlate with cutaneous symptoms. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

Cross-training policies for repair shops with spare part inventories

We study a spare part supply system for repairable spare parts where parallel repair servers may have multiple skills (can repair different failed parts). Demands for the spares occur according to Poisson processes with different rates. The failed spare parts are immediately replaced from the inventory. Otherwise, failed parts are backordered and fulfilled when a spare of the same type becomes available (repaired). The repair servers are heterogeneous and can process certain types of repairables only if they have the necessary skill. In this system, in contrast with the other skill-optimization models, there is a trade-off between adding extra skills to servers (training) or adding extra inventory. In this paper, we formulate a mathematical model to optimize the assignment of skills to servers taking into account inventories for the ready-to-use spares and backorder costs (penalties). To optimize the skill assignments and inventories, we use a hybrid approach combining a Genetic Algorithm (GA) with simulation modeling. The proposed simulation-based optimization heuristic is used for extensive analysis of optimal skill assignments where we show that partial flexibility for repair servers with limited cross-training will lead to lower total system cost.This publication was made possible by the NPRP award [ NPRP 7-308-2-128 ] from the Qatar National Research Fund (a member of The Qatar Foundation ).Scopu

Provider selection and task allocation in telecommunications with QoS degradation policy

The information age that we are living in is characterized by exponentially increasing needs and corresponding means to access, transmit and use data in a variety of business settings. Fast growing demand, which is translated to market opportunities, has led to the emergence of many new and well-established firms entering into the telecommunications market, resulting in a crowded, highly competitive business environment with numerous providers and carriers offering a wide range of data services. Today’s firms use telecommunication networks in a variety of ways to carry out their daily communications such as video conferencing, voice over IP and other data-intensive transmissions. In this paper, we report on a study in which we investigate a cost optimization problem that a firm encounters when acquiring network bandwidth from a telecommunication market that consists of many backbone providers offering different combinations of pricing policies and quality of service (QoS) levels. After the acquisition of network resources (bandwidth), firms allocate these resources to their daily data transmissions (tasks) according to the QoS requirement of the tasks. In an optimal allocation scheme, it is generally presumed that each task has to be assigned to a network resource which is capable of providing an equal or higher level of QoS than required by the task. However, it is shown with the proposed heuristic approach (presented herein) that QoS degradations during the allocation of tasks can lead to more favorable outcomes, especially when certain cost penalty policies are applied to the reduction of QoS requirements.Scopu

Global Impact of COVID-19 on Stroke Care and IV Thrombolysis

OBJECTIVE: To measure the global impact of COVID-19 pandemic on volumes of IV thrombolysis (IVT), IVT transfers, and stroke hospitalizations over 4 months at the height of the pandemic (March 1 to June 30, 2020) compared with 2 control 4-month periods. METHODS: We conducted a cross-sectional, observational, retrospective study across 6 continents, 70 countries, and 457 stroke centers. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases. RESULTS: There were 91,373 stroke admissions in the 4 months immediately before compared to 80,894 admissions during the pandemic months, representing an 11.5% (95% confidence interval [CI] -11.7 to -11.3, p &lt; 0.0001) decline. There were 13,334 IVT therapies in the 4 months preceding compared to 11,570 procedures during the pandemic, representing a 13.2% (95% CI -13.8 to -12.7, p &lt; 0.0001) drop. Interfacility IVT transfers decreased from 1,337 to 1,178, or an 11.9% decrease (95% CI -13.7 to -10.3, p = 0.001). Recovery of stroke hospitalization volume (9.5%, 95% CI 9.2-9.8, p &lt; 0.0001) was noted over the 2 later (May, June) vs the 2 earlier (March, April) pandemic months. There was a 1.48% stroke rate across 119,967 COVID-19 hospitalizations. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was noted in 3.3% (1,722/52,026) of all stroke admissions. CONCLUSIONS: The COVID-19 pandemic was associated with a global decline in the volume of stroke hospitalizations, IVT, and interfacility IVT transfers. Primary stroke centers and centers with higher COVID-19 inpatient volumes experienced steeper declines. Recovery of stroke hospitalization was noted in the later pandemic months. © 2021 American Academy of Neurology