I-123 metaiodobenzylguanidine imaging for predicting ventricular arrhythmia in heart failure patients

Compared to antiarrhythmic drugs, implantable cardioverter defibrillator （ICD） leads to a more significant im- provement in preventing ventricular arrhythmia in heart failure patients. However, an important question has been raised that how to select appropriate patients for ICD therapy. 1-123 metaiodobenzylguanidine （MIBG） planar and SPECT imaging have shown great potentials to predict ventricular arrhythmia in heart failure patients by as- sessing the abnormalities of the sympathetic nervous system. Clinical trials demonstrated that several parameters measured from 1-123 MIBG planar and SPECT imaging, such as heart-to-mediastinum ratio, washout rate, defect score, and innervation/perfusion mismatch, predicted ventricular arrhythmias in heart failure patients. This paper introduces the current practice of ICD therapy and reviews the technical background of 1-123 MIBG planar and SPECT imaging and their clinical data in predicting ventricular arrhythmia.

An Efficient Method to Estimate Admittance of Black-boxed Inverter-based Resources for Varying Operating Points

Traditional analytical approaches for stability assessment of inverter-based resources(IBRs),often requiring detailed knowledge of IBR internals,become impractical due to IBRs’proprietary nature.Admittance measurements,relying on electromagnetic transient simulation or laboratory settings,are not only time-intensive but also operationally inflexible,since various non-linear control loops make IBRs’admittance models operating-point dependent.Therefore,such admittance measurements must be performed repeatedly when operating point changes.To avoid time-consuming and cumbersome measurements,admittance estimation for arbitrary operating points is highly desirable.However,existing admittance estimation algorithms usually face challenges in versatility,data demands,and accuracy.Addressing this challenge,this letter presents a simple and efficient admittance estimation method for blackboxed IBRs,by utilizing a minimal set of seven operating points to solve a homogeneous linear equation system.Case studies demonstrate this proposed method ensures high accuracy across various types of IBRs.Estimation accuracy is satisfying even when non-negligible measurement errors exist.

Quality Improvement through Contract Design and Competition in Agricultural Suppply Chains

Quality emerges as a pivotal competitive factor for agricultural products.Recently,retailers within agricultural supply chains have begun investing in technologies to improve quality and designing contracts to incentivize farmers to enhance their labor inputs.The farmers and the retailers incur different quality investment costs,with this cost increasing in the quality they provide.Simultaneously,retailers have embraced the farmer-competition strategy,employing competition to stimulate improved agricultural product quality among farmers.We construct a Stackelberg game model to analyze how farmers’quality investment,retailer’s contract design,and profits are affected by the retailer’s farmer-competition strategy.We show that the farmer competition introduced by the retailer is not always effective in improving the farmer’s quality investment.Similarly,the competition cannot always lead to additional profits for the retailer.Moreover,the supply chain profit suffers from the retailer’s farmer-competition strategy when the competition intensity between farmers is relatively large.Our results offer insights for retailers by identifying how should the retailer design the contract to improve the farmer’s quality effort given the existence of the farmer competition and under what conditions the retailer should adopt the farmer-competition strategy.

The Influence of Significant Public Health Events on Offline Consumption and Its Pathways

In the face of a significant public health event,consumers may either increase their panic buying or decrease their willingness to make purchases.This study focuses on the impact of a significant public health event on offline store sales and consumer consumption,utilizing data from chain convenience stores in Hefei and Wuhu during early 2019 and early 2020 in China.Employing a difference-in-differences model,the study investigates the effect of the significant public health event outbreak on weekly store sales,order numbers,and consumer consumption in terms of product quantities,transaction amount,average amount per order,and transaction frequency.Different from prior literature that finds hoarding behavior of consumers online,the findings of this paper indicate a significant reduction in stores’offline weekly sales and order numbers,as well as consumers’offline weekly consumption across the four dimensions,as a result of the significant public health event outbreak.Additionally,employing a mediation model,the study explores the pathway of population mobility through which the significant public health event adversely affects offline consumption.Furthermore,subset analysis is conducted for stores located in different areas and consumers with varying characteristics,revealing that the aforementioned conclusions predominantly apply to stores situated in office areas and residential areas,as well as consumers with either no apparent preference for different product categories or a noticeable preference for food.

Make or Buy in the Presence of Strategic Competition on Substitutable Products

In this paper,we study make-or-buy decisions with the consideration of retail-level competition,in which a supplier provides substitutable products to two retailers.One incumbent retailer is capable of producing the product in-house and makes the make-or-buy decision,while the rival retailer can only outsource from the supplier.Intuitively,the incumbent will not outsource if the wholesale price is higher than its production cost.However,we illustrate this may not be true when the supplier also supplies the retail rival.In this case,the incumbent may accept a high wholesale price to limit the supplier's incentive to serve the retail rival on particularly favorable terms.Moreover,under certain circumstances,the supplier may charge a wholesale price lower than its production cost to attract orders from the incumbent,which can generate for the supplier and the incumbent a higher total profit than the situation in which the incumbent makes the product in-house.

Trade Credit and Buyer Financing

This study investigates trade credit and early payment financing in a three-party supply chain consisting of a manufacturer,a capital-constrained distributor,and a retail platform.The manufacturer or the platform provides the financing service to the distributor.Two different leadership structures are investigated,namely,platform and manufacturer leadership Stackelberg game,where the platform or manufacturer first makes the decision,respectively.Under trade credit financing,the manufacturer and the whole supply chain face loss when the commission rate increases.However,under buyer financing,they benefit from the high commission rate.Under platform leadership,the distributor,the manufacturer,and the supply chain perform better with trade credit if and only if the commission rate is small or the production cost is high,while the platform always prefers buyer financing.Under manufacturer leadership,the distributor,manufacturer,and supply chain perform better with trade credit under low production cost and commission rate.The platform prefers trade credit when production cost is in the intermediate range.By further analyzing the case that both financing channels are available and the distributor decides which one to choose,we find that the financing services competition hurts only the platform's profits.And under certain conditions,trade credit and early payment can achieve the same performance for every supply chain member.These findings enhance our understanding of the supply chain risk allocation efficiency of trade credit and early payment financing under different leadership structures.Neither risk allocation form outperforms the other,and the relative efficiency depends on supply chain characteristics.

DR3TBDTT Based Ternary Blends Containing Conjugated Polymers： Crystallization Determines Morphology and Performance

How the conjugated polymers affect the crystallization of DR3TBDTT, in addition to the corresponding morphology and performance, is not well understood. In this work, the weakly crystalline polymer PTB7-Th and highly crystalline polymers of PCDTBT and P3HT were incorporated into DR3TBDTT：PC71BM system to investigate the variation of crystallization, morphology and performance. It is demonstrated that PTB7-Th is the most effective additive to improve the PCE value of DR3TBDTT：PC71BM to 5.7%, showing the nucleating agent reducing the crystallization correlation length （CCL） value of DR3TBDTT from 18.7 nm to 17.0 rim, in addition to the optimized morphology. In contrast, the PCDTBT and P3HT could induce the crystallization of DR3TBDTT, leading to much higher CCL value as well as obvious phase separation. Despite of energy level alignment, the crystallization of DR3TBDTT influenced by polymers determines the corresponding morphology of active layers and photovoltaic performance.

Phase inversion in a lightweight high Al content refractory high-entropy alloy

Adding Al is an important strategy to obtain ultrahigh specific strength in BCC refractory high-entropy alloys(RHEAs).However,the main structure typically transitions from disordered BCC to ordered B2 with increasing Al concentration,leading to poor ductility.In the present study,a phase inversion in a high-Al-content B2-RHEA(Zr_(40)Ti_(28)Nb_(12)Al_(20))was systematically studied through thermo-mechanical treatment.The grains of the single B2 phase transformed inversely to the BCC+B2 microstructure with a dispersion of spherical B2 precipitates in the BCC grains.The evolution of the microstructure began with the decomposition of the B2 phase into Al-rich and Al-poor regions.The subsequent coarsening of the Al-rich B2 precipitates continuously consumes Al and Zr atoms from the solution.The depletion of Al and Zr in the matrix drives it to gradually form the disordered BCC structure and eventually transform to a single BCC phase matrix.This phase inversion enhanced tensile ductility of the RHEA while still maintaining its high specific strength.The current study provides a novel idea for inhibiting Al-induced brittleness of RHEAs at high Al content.

OUTSOURCING DECISION AND ORDER POLICY WITH FORECAST UPDATING UNDER CAPACITY RESERVATION CONTRACT

This paper investigates an optimal decision problem in a single-period, two-stage supply chain with capacity reservation contract. At the beginning of the planning horizon, the retailer, who faces stochastic demand, reserves future capacity according to his forecasting of the demand. The supplier then constructs capacity. At the beginning of the selling season, the retailer updates the demand forecasting and places an order. When the retailer＇s demand is greater than the supplier＇s capacity, the supplier can meet the retailer＇s demand by outsourcing. We analyze the optimal decision of each player in both centralized and decentralized systems. Furthermore, under the case in which demand follows a uniform distribution, we obtain the closed-form optimal strategies of each player for both centralized and decentralized systems and conduct numerical studies to reveal additional conclusions. The numerical studies show that the optimal reservation capacity for the retailer and the optimal constructing capacity for the supplier in the decentralized system are both less than the optimal constructing capacity in the centralized system. Furthermore, we also find that the profit loss due to decentralization always exists and increases in indeterminacy.

Coping with the Bullwhip Effect Using Inventory or Cash: An Environment-Behavior-Performance Paradigm

The bullwhip effect is w idely found in business and exerts adverse effects on business activities.To investigate the influence of the bullwhip effect on firm s'performance and their responses,this study proposed an environment-behavior-performance analysis fram ework and offered a new perspective for studying the bullwhip effect.Using data collected from 1,734 listed manufacturers in China from 2002 to 2017,we adopted regression models to test the proposed m odel and conducted a series of robustness tests.We find that the bullwhip effect is positively related to operating risk,inventory,and cash holdings,and the moderate levels of inventory and cash are negatively associated with operating risk.Specifically,inventory and cash play different roles and work together to alleviate operating risk induced by the bullwhip effect.However,excess resource holdings are positively associated with operating risk.Therefore,firm swith different levels of resources should hold suitable levels of inventory,cash,or both as contingent responses to the bullwhip effect.

Aberrant single-subject morphological brain networks in first-episode,treatment-naive adolescents with major depressive disorder

Background:Neuroimaging-based connectome studies have indicated that major depressive disorder(MDD)is associated with dis-rupted topological organization of large-scale brain networks.However,the disruptions and their clinical and cognitive relevance are not well established for morphological brain networks in adolescent MDD.Objective:To investigate the topological alterations of single-subject morphological brain networks in adolescent MDD.Methods:Twenty-five first-episode,treatment-naive adolescents with MDD and 19 healthy controls(HCs)underwent T1-weighted magnetic resonance imaging and a battery of neuropsychological tests.Single-subject morphological brain networks were constructed separately based on cortical thickness,fractal dimension,gyrification index,and sulcus depth,and topologically characterized by graph-based approaches.Between-group differences were inferred by permutation testing.For significant alterations,partial correla-tions were used to examine their associations with clinical and neuropsychological variables in the patients.Finally,a support vector machine was used to classify the patients from controls.Results:Compared with the HCs,the patients exhibited topological alterations only in cortical thickness-based networks character-ized by higher nodal centralities in parietal(left primary sensory cortex)but lower nodal centralities in temporal(left parabelt complex,right perirhinal ectorhinal cortex,right area PHT and right ventral visual complex)regions.Moreover,decreased nodal centralities of some temporal regions were correlated with cognitive dysfunction and clinical characteristics of the patients.These results were largely reproducible for binary and weighted network analyses.Finally,topological properties of the cortical thickness-based net-works were able to distinguish the MDD adolescents from HCs with 87.6%accuracy.Conclusion:Adolescent MDD is associated with disrupted topological organization of morphological brain networks,and the disrup-tions provide potential biomarkers for diagnosing and monitoring the disease.