Hub Center Research Articles

Estimation of Hub Center Loads for Individual Pitch Control for Wind Turbines Based on Tower Loads and Machine Learning

Estimation of Hub Center Loads for Individual Pitch Control for Wind Turbines Based on Tower Loads and Machine Learning

A comprehensive study on Mecanum wheel-based mobility and suspension solutions for intelligent nursing wheelchairs

Intelligent nursing wheelchairs significantly enhance mobility and independence for elderly individuals with disabilities. However, traditional designs often suffer from large turning radii that restrict their functionality in confined spaces. Addressing this critical challenge, this study introduces an innovative design utilizing a Mecanum wheel chassis that allows for omnidirectional movement, significantly improving maneuverability and stability. Our design incorporates independently controlled Mecanum wheels, overcoming traditional constraints and enhancing user autonomy. To address issues such as wheel spacing variations and hub center tilting, which can lead to slipping and inaccurate motion control, we developed a novel suspension system that stabilizes the chassis, minimizes slipping risks, and boosts motion control accuracy. Experimental validations, including shock absorption and positioning tests, demonstrate that our suspension system markedly enhances the wheelchair's control performance and stability, thereby providing users with enhanced precision and potentially improving their quality of life.

Integrating RapidAI in an Evolving Hub and Spoke Center

Introduction/Background: As the rapid assessment of suspected stroke patients is imperative to reduce death and disability, rapid and reliable imaging studies are required to guide treatment decisions for thrombolytic therapies and thrombectomy. The integration of Artificial intelligence (AI) imaging platforms within acute stroke assessment has been shown to improve treatment times with the overall goal of improving outcomes. The process of adoption of this technology has not been well described. We sought to describe a process of adopting one AI imaging platform, RapidAI, within a hub and spoke health care system in the mid-south United States. Methods: Using a process improvement model which identified the need for more convenient and rapid interpretation of imaging, we sought to identify the specific steps of technology adoption, ensuring success in the transition to RapidAI to support faster interpretation times among multiple members of the acute stroke team. Results: Because of strong leadership at the system level, our organization has been able to incorporate RapidAI in all spoke centers for the acute evaluation and treatment of stroke patients. Conclusions: AI imaging platforms, such as RapidAI, can be incorporated within hub and spoke systems of care through strong system leadership and distinct steps. These steps could also be considered for stand-alone facilities with the creation of strong partnerships in the treatment of acute stroke patients.

Real-world biomarker testing patterns: clinical-pathological portrait of early and late non-small cell lung cancer in hub and spoke North Italian centers.

Lung cancer is still the main cause of cancer death. In the last decades, significant innovations were introduced in non-small cell lung cancer (NSCLC) treatment and management improving patient outcomes. The discovery of immune checkpoint inhibitors and the detection of an increasing list of actionable genetic alterations are enabling a tailored approach. Herein, we assessed in a pragmatic retrospective study the rate of biomarker tests within a large pulmonary pathology-based unit (PPU) network of the Veneto region (Northern Italy). Each PPU of 7 hubs and spoke centers implemented a biomarker database with pathologic and clinical data of patients with NSCLC diagnosis over 24 months. Out of 1,817 NSCLC cases, 51% were advanced and 49% early stage, with 72% being adenocarcinomas. Programmed death ligand 1 expression and epidermal growth factor receptor mutations were available in most samples, 91% and 78%, respectively. Only 36% of advanced stages received all 5 biomarker tests with an increased rate over time. Co-occurring molecular alterations were detected in 42 cases (2%): the prevalence was (n=17) 41% and (n=25) 59% in early and late-stage adenocarcinomas, respectively. In this real-world study, while most patients received at least one biomarker test, less than 50% had all 5 biomarkers. The screening appeared to increase over time especially with the progressive use of next generation sequencing. Our results confirm the importance of systematic biomarker testing including all NSCLCs based on the evidence of several genomic alterations also in early-stage disease whose analysis may become relevant as neo-adjuvant targeted therapies are available. Non-small cell lung cancer (NSCLC); biomarkers; actionable targets; lung cancer.

“Transience, Disruption, and Unfamiliarity in Refugee Journeys”: How Are Newly Arrived Refugee Families Supported in Their Children’s Transition to School in a Host Country?

ABSTRACT Newly arrived refugee families face cultural and linguistic difficulties when navigating their children’s transition to school in a host country. However, little is known about how families are supported in their child’s transition to school. Therefore, this article aimed to investigate how leaders and facilitators in community hubs and centers support refugee families in their child’s transition to school in Australia. Data gathered from interviews with 32 community hub leaders and center facilitators from three Australian states were analyzed thematically. The support provided to families fell into six themes: promoting children’s early learning; building families’ or mothers’ capital about starting school; promoting connections between school, families, and children; offering cultural and linguistic brokerage; providing soft entry support; and easing children’s and families’ transition to school via school-based transition activities and programs. The implications of this holistic model of support for educators that is built on place and strength-based approaches in facilitating newly arrived refugee children’s and families’ smooth start to school in their new communities are outlined.

Kebijakan Penta Helix dalam Pengembangan Parawisata Musik di Kota Ambon

Ambon City is known as the World Music City. As a music city, Ambon has a tourism appeal related to music. This research aims to understand the implementation of the Pentahelix policy by the Ambon City Government for the development of Ambon City as a World Music City, and to formulate and recommend strategies for collaboration among the Pentahelix actors in the implementation of the policy for the development of Ambon City as a World Music City. This research utilizes qualitative descriptive methods. The results of this study indicate that the Pentahelix policy model needs further optimization because the integrity among stakeholders is still low. Furthermore, there are several formulated recommendations and strategies that can be applied, including establishing a collaborative forum for Ambon music tourism, promoting communication among stakeholders, strengthening the AMO as a data hub and coordination center, making AMO an independent institution, stimulating communication and business initiatives, conducting research related to music tourism, developing an appropriate tourism calendar, educating and raising public awareness, conducting promotional campaigns through media, periodic monitoring and evaluation, as well as human resource development.

Novel Approaches for Early Detection of Retinal Diseases Using Artificial Intelligence.

An increasing amount of people are globally affected by retinal diseases, such as diabetes, vascular occlusions, maculopathy, alterations of systemic circulation, and metabolic syndrome. This review will discuss novel technologies in and potential approaches to the detection and diagnosis of retinal diseases with the support of cutting-edge machines and artificial intelligence (AI). The demand for retinal diagnostic imaging exams has increased, but the number of eye physicians or technicians is too little to meet the request. Thus, algorithms based on AI have been used, representing valid support for early detection and helping doctors to give diagnoses and make differential diagnosis. AI helps patients living far from hub centers to have tests and quick initial diagnosis, allowing them not to waste time in movements and waiting time for medical reply. Highly automated systems for screening, early diagnosis, grading and tailored therapy will facilitate the care of people, even in remote lands or countries. A potential massive and extensive use of AI might optimize the automated detection of tiny retinal alterations, allowing eye doctors to perform their best clinical assistance and to set the best options for the treatment of retinal diseases.

Impact and determinants of door in-door out time for stroke thrombectomy transfers in a large hub-and-spoke network.

The mantra "time is brain" cannot be overstated for patients suffering from acute ischemic stroke. This is especially true for those with large vessel occlusions (LVOs) requiring transfer to an endovascular thrombectomy (EVT) capable center. We sought to evaluate the spoke hospital door in-door out (DIDO) times for patients transferred to our hub center for EVT. Individuals who first presented with LVO to a spoke hospital and were then transferred to the hub for EVT were retrospectively identified from a prospectively maintained database from January 2019 to November 2022. DIDO was defined as the time between spoke hospital door in arrival and door out exit. Baseline characteristics, treatments, and outcomes were compared, dichotomizing DIDO at 90 minutes based in the American Heart Association goal for DIDO ≤90 minutes for 50% of transfers. Multivariable regression analyses were performed for determinants of the 90-day ordinal modified Rankin Scale (mRS) and DIDO. We identified 194 patients transferred for EVT with available DIDO. The median age was 67 years (IQR 57-80), and 46% were female. The median National Institutes of Health Stroke Scale (NIHSS) was 16 (10-20), 50% were treated with intravenous thrombolysis at a spoke, and TICI 2B-3 reperfusion was achieved in 87% at the hub. The median DIDO was 120 minutes (97-149), with DIDO ≤90 minutes achieved in 18%. DIDO was a significant determinant of 90-day ordinal mRS (B = 0.007, 95% CI = 0.001-0.012, p = 0.013), even when accounting for the last known well-to-spoke door in, spoke door out-to-hub arrival, hub arrival-to-puncture, puncture-to-first pass, age, NIHSS, intravenous thrombolysis, TICI 2B-3, and symptomatic intracranial hemorrhage. Importantly, determinants of DIDO included Black race or Hispanic ethnicity (B = 0.918, 95% CI = 0.010-1.826, p = 0.048), atrial fibrillation or heart failure (B = 0.793, 95% CI = 0.257-1.329, p = 0.004), and basilar LVO location (B = 2.528, 95% CI = 1.154-3.901, p < 0.001). Spoke DIDO was the most important period of time for long-term outcomes of LVO stroke patients treated with EVT. Targets were identified to reduce DIDO and improve patient outcomes.

Neurological abnormalities in individuals with Marfan syndrome: results from a genetically confirmed Italian cohort.

Neurological abnormalities have been frequently reported in individuals with Marfan Syndrome (MFS). However, available data relies solely on retrospective studies predating current diagnostic criteria. Cross-sectional study comprehensively investigating neurological abnormalities within a prospective cohort of adults (≥ 18years) with genetically confirmed MFS referred to an Italian hub center for heritable connective tissue diseases (Jan. 1st - Nov. 15th, 2021). We included a total of 38 individuals (53% female). The commonest neurological symptom was migraine (58%), usually without aura (73%). Neuropsychological testing was generally unremarkable, whilst anxiety and depression were highly prevalent within our cohort (42% and 34%, respectively). The most frequent brain parenchymal abnormality was the presence of cortico-subcortical hypointense spots on brain MRI T2* Gradient-Echo sequences (39%), which were found only in patients with a prior history of aortic surgery. Migraineurs had a higher frequency of brain vessels tortuosity vs. individuals without migraine (73% vs. 31%; p = 0.027) and showed higher average and maximum tortuosity indexes in both anterior and posterior circulation brain vessels (all p < 0.05). At univariate regression analysis, the presence of brain vessels tortuosity was significantly associated with a higher risk of migraine (OR 5.87, CI 95% 1.42-24.11; p = 0.014). Our study confirms that neurological abnormalities are frequent in individuals with MFS. While migraine appears to be associated with brain vessels tortuosity, brain parenchymal abnormalities are typical of individuals with a prior history of aortic surgery. Larger prospective studies are needed to understand the relationship between parenchymal abnormalities and long-term cognitive outcomes.

Impact of capacity building and tele ECG based decision support on change in thrombolysis rate and inhospital and one year mortality in patients with STEMI, using hub and spoke model; multi-phasic intervention trial

BackgroundWe report the impact of capacity building and teleconsultation on change in the thrombolysis rates and one-year mortality in patients with STEMI using a hub and the spoke model of STEMI care. MethodsTwenty secondary care public hospitals were linked with a teaching hospital as a hub centre and the impact of the intervention on change in ischemic time, thrombolysis rates and all-cause in-hospital and one-year mortality was compared. Results29 patients with STEMI were treated during pre-intervention from April 2020 to June 2020 and 255 patients during the post-intervention period from July 2020 to Oct 2021 in spoke centres. 245 patients were reported to a hub centre during the study period. The thrombolysis rate was significantly higher in the spoke centres after intervention (65.5%vs. 27.5 % p < 0.001) and was also significantly higher than in patients treated in a hub centre (65.5 % vs. 45.7 % p < 0.01). The in-hospital mortality was significantly lower in patients treated at spoke centres compared to those treated at the hub centre (7.8 % vs. 15.5 % < 0.003). The significant difference in mortality rate continued at one year (11.0 % vs.18.4 % p < 0.01). The median time from symptoms to thrombolytic therapy was significantly lower in STEMI patients treated in spoke centres compared to a hub centre (230 min vs. 356 min p < 0.001). ConclusionThe hub and spoke model of STEMI care is effective in increasing thrombolysis rate, and decreasing in-hospital and one-year mortality rate.

The hybrid ablation approach to treating long-standing persistent atrial fibrillation: real-world data from a tertiary institution

Abstract Background Pulmonary vein isolation(PVI) is effective treatment for atrial fibrillation(AF) but efficacy of endocardial ablation-alone for long-standing persistent AF is limited(1). Hybrid AF ablation may offer better outcomes but studies were on patients with paroxysmal/persistent-AF(2) and relied on Holter-alone to assess recurrences(3). Our hybrid-AF ablation patients were all long-standing persistent cases and monitored with implantable loop recorders(ILR). Aim Evaluate long-term outcomes of hybrid-AF ablation using ILR data. Methods The hybrid approach at our institution consisted of a first-stage minimally invasive surgical epicardial ablation of the left atrial posterior wall via radiofrequency (RF) ablation. An ILR was implanted at the same setting. A few months later, the second-stage endocardial catheter ablation was performed to ensure PVI and ‘touch-up’ of any residual conduction gaps in the left atrium. All epicardial ablation cases were performed at the cardiothoracic operating-room in our tertiary hospital (‘hub’) whilst the endocardial RF-cases were performed at either the hub or satellite centre(‘spoke’) as part of our institution’s ‘hub-and-spoke’ model. Inclusion criteria for hybrid AF-ablation were long-standing persistent AF, body mass index (BMI) &amp;lt;40 and standard indications for AF ablation as per ESC 2020 AF guidelines(4). Once both aspects of the hybrid approach were completed, patients were followed up in ILR remote monitoring clinics. AF recurrence was defined as AF/atrial tachycardia(AT) lasting &amp;gt;30s. All data were obtained retrospectively via hospital electronic patient records. Results 38 consecutive patients completed both aspects of hybrid ablation between December 2017-August 2023 with mean follow up of 19±13months(mean±SD). Baseline data, procedure characteristics and details of complications are shown in Table 1. ILR data was obtained in 36/38 patients(ILR implantation precluded in one due to previous breast cancer surgery. One had ILR battery depletion contributed by significant delay between the 2 stages of the hybrid ablation). AF/AT recurred in one third of patients during the blanking period(3 months) whilst 45% remained in sinus rhythm at 1-year; at 2yrs, 39% maintained SR and 25% at 3yrs (Figure 1). Post-hybrid ablation, two patients underwent re-do AF/AT ablation. The relatively high recurrence rate compared to other studies may be due to: very long duration of AF prior to hybrid-ablation(7.0±3.6years), significant delay between both stages of the procedure(9±11months) due to the pandemic and competing waiting list pressures, multiple comorbidities (82% had &amp;gt;2 comorbidities, 42% were obese) and the higher arrhythmia pickup rate with ILRs compared with intermittent rhythm monitoring. Conclusion Our study provides real world insight into the challenges of delivering a hybrid AF ablation service but highlights its utility in long-standing persistent AF patients.Table 1Figure 1

DEVELOPMENT OF A HUB–SPOKE NETWORK FOR TRANSCATHTER AORTIC VALVE IMPLANTATION: THE INTERVENTIONAL CARDIOLOGY UNIT OF IRCCS SAN RAFFAELE HOSPITAL (OSR HUB–SPOKE)

Abstract Background The growing prevalence of aortic stenosis determined in recent years an increase in candidates for percutaneous aortic valve replacement (TAVI), bringing out a difficult access to this procedure. In order to reduce waiting lists and to guarantee the training of the Interventional Cardiologists of Centers not equipped with on–site cardiac surgery, we implemented a TAVI protocol with one Hub center, the Interventional Cardiology Unit of IRCCS San Raffaele Scientific Institute, Milan, and two participating Spoke Centers: the ASST–Franciacorta Chiari Center and Valduce Hospital, Como.The aim of this study is to report in hospital outcomes of patients treated using this model of Hub–Spoke Network. Methods Patients included in this model were selected in the Spoke center where baseline clinical evaluation with echocardiography and CT scan were performed (inclusion and exclusion criteria attached). The cases were then discussed with a multidisciplinary team on–line and the procedure planned (access, valve type size). Once the procedure was scheduled, the patients underwent a single day transport to the Hub Center where they underwent TAVI and a same day return to the Spoke Center. A bailout hospitalization in the Hub Center was available in case of major complication. All Spoke Centers patients who underwent TAVI procedures in our Center according to our protocol were included in this analysis. The primary study objective was in hospital major adverse cardiac events (all cause or cardiovascular mortality, stroke, myocardial infarction); secondary study objectives were technical success, prolonged recovery in Hub Center and major vascular complications. Results Since 2019, a total of 69 patients underwent TAVI with the Hub and Spoke model. Mean age was 83 years ± 6 and mean ejection fraction was 59% ± 7%. Two patients (2.9%) had a prolonged hospitalization in the Hub center for a major vascular complication and an intra–procedural cardiac arrest, successfully resuscitated. Technical success was reached in 97.1% of patients. One patient experimented an ischemic stroke after the return in the spoke center: in hospital MACE was than 1.4%. Conclusion Considering the growing prevalence of aortic stenosis, The Hub Spoke Model for TAVI guarantees reduction in waiting lists, "access to care" for patients referred to Spoke centers, involvement and improvement of skills of their Interventional Cardiologists, keeping a high level of safety and efficacy.

Economic evaluation of anti-CD19 CAR T-cell pathway for large B-cell lymphomas in the real-life setting: the experience of an Italian hub center in the first three years of activity

Poor literature report actual and detailed costs of chimeric antigen receptor (CAR) T-cell pathway in a real-life setting. We retrospectively collect data for all patients with relapsed/refractory aggressive large B-cell lymphoma who underwent leukapheresis between August 2019 and August 2022. All costs and medical resource consumption accountability were calculated on an intention-to-treat (ITT) basis, starting from leukapheresis to the time when the patient (infused or not) exited the CAR T-cell pathway for any reason. Eighty patients were addressed to leukapheresis and 59 were finally infused. After excluding CAR-T product cost, the main driver of higher costs were hospitalizations followed by the examinations/procedures and other drugs, respectively 43.9%, 26.3% and 25.4% of the total. Regarding costs of drugs and medications other than CAR T products, the most expensive items are those referred to AEs, both infective and extra-infective within 30 days from infusion, that account for 63% of the total. Density plot of cost analyses did not show any statistically significant difference with respect to the years of leukapheresis or infusion. To achieve finally 59/80 infused patients the per capita patients without CAR-T products results 74,000 euros. This analysis covers a growing concern on health systems, the burden of expenses related to CAR T-cell therapy, which appears to provide significant clinical benefit despite its high cost, thus making economic evaluations highly relevant. The relevance of this study should be also viewed in light of continuously evolving indications for this therapy.

Integrating Pharmacomechanical Treatments for Pulmonary Embolism Management within a Hub-and-Spoke System in the Swiss Ticino Region.

The Swiss Ticino regional pulmonary embolism response team (PERT) features direct access to various pharmacomechanical PE management options within a hub/spoke system, by integrating evidence, guidelines' recommendations and personal experiences. This system involves a collaborative management of patients among the hospitals distributed throughout the region, which refer selected intermediate-high or high PE patients to a second-level hub center, located in Lugano at Cardiocentro Ticino, belonging to the Ente Ospedaliero Cantonale (EOC). The hub provides 24/7 catheterization laboratory activation for catheter-based intervention (CBI), surgical embolectomy and/or a mechanical support system such as extracorporeal membrane oxygenation (ECMO). The hub hosts PE patients after percutaneous or surgical intervention in two intensive care units, one specialized in cardiovascular anesthesiology, to be preferred for patients without relevant comorbidities or with hemodynamic instability and one specialized in post-surgical care, to be preferred for PE patients after trauma or surgery or with relevant comorbidities, such as cancer. From April 2022 to December 2023, a total of 65 patients were referred to the hub for CBI, including ultrasound-assisted catheter-directed thrombolysis (USAT) or large-bore aspiration intervention. No patient received ECMO or underwent surgical embolectomy.

Omni-Channel Distribution: A Transshipment Modeling Perspective

In our work, we develop a specialized optimization technique that adapts the general linear programming Transshipment model to the ever-growing needs of Omni-Channel distribution in Supply Chain Management. With the rapid adoption of “smart” mobile technologies, customers now acquire merchandise across multiple channels and devices. As a result, retailers are challenged with downstream operational complexities. Fulfillment of customer orders now changes the placement and amount of independent demand inventory organizations may hold. Our research integrates the use of Hub or Fulfillment Centers, locations where sellers fill customer orders placed through e-commerce, as an additional segment of demand. This adaptation to the optimization of Transshipment can result in significant benefits to the firm’s logistics presence, customer retention, and profit.

Treating and caring for migrant populations suffering from infectious diseases: the experience of the hub&spoke network set up by the Civico Benfratelli ARNAS Hospital in Palermo (Sicily Region, Southern Italy)

This paper describes the experience carried out in a general hospital, implemented in collaboration with a city network of associations involved in the care of migrant populations. Considering the vulnerability of these populations, the difficulty of access to healthcare facilities, and the linguistic and cultural barriers, an organisational model was designed characterised by the concentration of highly complex care (hub centre) supported by a network of peripheral reception centres (spoke centres) responsible for selecting patients and sending them to the centre of reference with the aim of offering screening for sexually transmitted infections, tuberculosis, taking charge of pathologies, including non-infectious ones, treatment, and follow-up. The effectiveness of the model was measured in relation to the continuum of care and its effectiveness with reference to the Joint Commission International guidelines.

Abstract WP191: Impact and Determinants of Door In-Door Out Time for Stroke Thrombectomy Transfers: Real World Analysis of a Large Hub-and-Spoke Network

Introduction: The mantra ‘time is brain’ cannot be overstated for patients suffering from acute ischemic stroke. This is especially true for those with large vessel occlusions (LVO) requiring transfer to an endovascular thrombectomy (EVT) capable center. We sought to evaluate the spoke hospital door in-door out (DIDO) times for patients transferred to our hub center for EVT. Methods: Individuals who first presented with LVO to a spoke hospital and were then transferred to the hub for EVT were retrospectively identified from a prospectively maintained database from January 2019 to November 2022. DIDO was defined as the time between spoke hospital door in arrival and door out exit. Baseline characteristics, treatments, and outcomes were compared, dichotomizing DIDO at 90 min based in the American Heart Association goal for DIDO ≤90 min for 50% of transfers. Multivariable regression analyses were performed for determinants of 90-day ordinal modified Ranking Scale (mRS) and DIDO. Results: We identified 194 patients transferred for EVT with available DIDO. The median age was 67 (IQR 57-80), and 46% were female. The median NIHSS was 16 (10-20), 50% were treated with intravenous thrombolysis at a spoke, and TICI 2B-3 reperfusion was achieved in 87% at the hub. The median DIDO was 120 min (97-149), with DIDO ≤90 min achieved in 18%. DIDO was a significant determinant of 90-day ordinal mRS (B=0.007, 95%CI=0.001-0.012, p=0.013), even when accounting for last known well-to-spoke door in, spoke door out-to-hub arrival, hub arrival-to-puncture, puncture-to-first pass, age, NIHSS, intravenous thrombolysis, TICI 2B-3, and symptomatic intracranial hemorrhage. Importantly, determinants of DIDO included Black race or Hispanic ethnicity (B=0.918, 95%CI=0.010-1.826, p=0.048), atrial fibrillation or heart failure (B=0.793, 95%CI=0.257-1.329, p=0.004), and basilar LVO location (B=2.528, 95%CI=1.154-3.901, p&lt;0.001). Conclusion: In this real-world analysis of a large hub-and-spoke network, spoke DIDO was the most important period of time for long term outcomes of LVO stroke patients treated with EVT. Determinants of DIDO were identified which require further investigation and motivate system changes that may reduce DIDO and improve patient outcomes.

A two-phase model for resilient hub and mobile distribution centers location

Hub location is crucial for resilient and uninterrupted supply chain operations, particularly during disruptions or unforeseen events. In this paper, we propose a resilience hub location framework for Third Party Logistics (3PL) companies with two key objectives: optimizing demand flows and establishing a resilient network capable of with-standing sudden disruptions. The study aims to identify the key criteria that contribute to the successful implementation of the resilient center. The proposed structure utilizes a two-phase decision-making methodology. The first phase presents a new Multi-Criteria Decision-Making (MCDM) approach called SWARA-EDAS method that evaluates and ranks potential locations based on resiliency criteria. The second phase proposes an optimization model to determine the optimal hub location. To illustrate the approach, a real-world case study of a 3PL company in Tehran is included. Due to the absence of precise demand data in the case study, a novel clustering approach is proposed to estimate the demand flow. Each individual cluster can be considered as a distinct demand point, and a clustering analysis involving 122 regions within Tehran is conducted, taking into account various factors such as population, economic index, accessibility to the Internet, and number of business units. To enhance the resiliency of the network, mobile distribution centers are also deployed. These mobile centers not only provide flexibility but also serve as backup capabilities in the event of a disruption or failure at the fixed hub. The proposed structure offers practical in-sights for 3PL companies seeking to implement a resilient network structure.

The role of an integrated referral program for patients with liver disease: A network between hub and spoke centers.

Access to Liver transplantation (LT) can be affected by several barriers, resulting in delayed referral and increased risk of mortality due to complications of the underlying liver disease. To assess the clinical characteristics and outcomes of patients with acute or chronic liver disease referred using an integrated referral program. An integrated referral program was developed in 1 October 2017 based on email addresses and a 24/7 telephone availability. All consecutive adult patients with liver disease referred for the first time using this referral program were prospectively collected until 1 October 2021. Characteristics and outcomes of inpatients were compared with a historical cohort of patients referred without using the integrated referral program (1 October 2015-1 October 2017). Patients were further divided according to pre- and post-Covid-19 pandemic. Two hundred eighty-one referred patients were considered. End stage liver disease was the most common underlying condition (79.3%), 50.5% of patients were referred as inpatients and 74.7% were referred for LT evaluation. When inpatient referrals (n=142) were compared with the historical cohort (n=86), a significant increase in acute liver injury due to drugs/herbals and supplements was seen (p=0.01) as well as an increase in End stage liver disease due to alcohol-related liver disease and NASH, although not statistically significant. A significant increase in referrals for evaluation for Trans-jugular intrahepatic portosystemic shunt placement was seen over time (5.6% vs. 1%; p=0.01) as well as for LT evaluation (84.5% vs. 81%; p=0.01). Transplant-free survival was similar between the study and control groups (p=0.3). The Covid-19 pandemic did not affect trends of referrals and patient survival. The development of an integrated referral program for patients with liver disease can represent the first step to standardize already existing referral networks between hub and spoke centers. Future studies should focus on the timing of referral according to different etiologies to optimize treatment options and outcomes.

Numerical and Experimental Investigation of a Volumetric Resistance Blower Performance and Its Optimization for Portable Computing Device Applications

Abstract In this paper, we present our results on a relatively new kind of blower called Volumetric Resistance Blower (VRB) for cooling of portable computing platforms like laptop computers. The VRB performance was modeled numerically and compared to traditional bladed blowers. The sources of noise, dominant in bladed blower, are absent in case of VRB, because it uses a continuous porous disk instead of discrete blades. Thus, even though at iso-rpm, VRB yielded lower flowrate, its iso-acoustic performance could be superior. Hence, further analysis was crucial to quantify the potential benefit. The acoustics experiments for bladed blower and VRB were conducted in a hemi-anechoic chamber in accordance with ECMA-74 and ECMA TR/99 standards. Iso-acoustics pressure versus volume flowrate plot for both bladed blower and VRB are compared. VRB was found to have superior performance as compared to bladed blower. The volume flowrate at open flow condition for bladed blower and VRB are comparable, but as back pressure increased the flowrate yielded by VRB kept increasing and at stagnation condition, VRB showed around 79% higher static pressure. In the second part of the work, the experimentally validated numerical model for VRB was used for numerical optimization using a design of experiments (DOE) approach and varying the geometrical parameters. Rotor distance (minimum distance from the axis of rotation of impeller to the cutwater surface) was found to be the most important parameter, and an optimum value was found. A second DOE elucidated the optimal rotor hub center location in the two-dimensional space inside the casing as when the rotor is tucked back into the casing as much as possible and when the rotor distance is above 20.15 mm. A partial P–Q curve is generated (up to 20 Pa) for optimal geometry configuration. Based on the numerical and experimental evidence, VRB is found to have the potential to replace traditional bladed design in portable computing devices. In addition, due to absence of blades, it creates lower tonal noise, giving a much more comfortable experience to the end user.