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A conservative hemoglobin transfusion threshold is noninferior to a liberal threshold in cardiac surgery. However, red blood cell (RBC) transfusion remains common during cardiac surgery. The authors' single-center, retrospective study aimed to decrease RBC transfusions for hemoglobin >7.5 g/dL in nonemergent cardiovascular surgeries utilizing cardiopulmonary bypass (CPB), by educating the anesthesiology and surgical staff on the benefits of a conservative threshold for transfusions, and incorporating the discussion and routine use of blood conservation methods for all nonemergent cardiac surgeries. This was a single-center, retrospective study that included all nonemergent coronary artery bypass grafting and single-valve cases utilizing CPB from January 2018 to December 2021 before and after the intervention in July 2019. The data involved a single community hospital. A total of 417 patients were included in the study. The authors adopted a conservative threshold for blood transfusion and implemented a collaborative multidisciplinary approach to blood conservation. Baseline patient characteristics were summarized, and the incidence of RBC transfusion before and after the intervention on July 26, 2019, were compared by Wilcoxon rank sum and chi-square tests. Multivariate logistic regression was used. The intervention was significantly associated with reduced RBC transfusion rate after adjusting for confounding variables (p < 0.05). The odds of receiving an RBC transfusion among patients after the intervention was 0.615 times the odds among patients before intervention (95% CI: 0.3913-0.9663). The authors' goal was to improve patient outcomes and the quality of perioperative care during cardiac surgery. By implementing a protocol and educating anesthesiologists, surgeons, and perfusionists, they successfully decreased the incidence of RBC transfusion above a hemoglobin of 7.5 g/dL. [ABSTRACT FROM AUTHOR]

Li-ion batteries are used widely for electrochemical energy storage and conversion. Heat generation during the operation of a Li-ion cell results in large temperature rise, particularly at high discharge rates. Accurate prediction of temperature rise during operation is a key technical challenge that directly affects both performance and safety. Li-ion cells are often used in cyclic charge/discharge manner, making this a particularly important process to study. This paper presents an experimentally-validated analytical method to rapidly and accurately predict the temperature field in a Li-ion cell undergoing cyclic charge and discharge. Based on recursive solution of the governing energy equation during the cyclic process, this method computes temperature around 16X faster than finite-element simulations, and is found to be in very good agreement with experimental data for over fifty cycles of high-rate cycling of 18650 Li-ion cells. Results indicate that heat loss through the metal foil that provides electrical interconnection is a critical process that governs overall thermal behavior of the cell. A novel technique based on determining the effective heat transfer coefficient of the interconnection is described, which is shown to agree very well with experimental data. Results from this paper may be helpful for design of Li-ion cell systems, as well as real-time temperature prediction and performance optimization. [ABSTRACT FROM AUTHOR]

Thermal runaway is a well-known safety concern in Li-ion cells. Methods to predict and prevent thermal runaway are critically needed for enhanced safety and performance. While much work has been done on understanding the kinetics of various heat generation processes during thermal runaway, relatively lesser work exists on understanding how heat removal from the cell influences thermal runaway. Through a unified analysis of heat generation and heat removal, this paper derives and experimentally validates a non-dimensional parameter whose value governs whether or not thermal runaway will occur in a Li-ion cell. This parameter is named the Thermal Runaway Number ( TRN ), and comprises contributions from thermal transport within and outside the cell, as well as the temperature dependence of heat generation rate. Experimental data using a 26650 thermal test cell are in good agreement with the model, and demonstrate the dependence of thermal runaway on various thermal transport and heat generation parameters. This parameter is used to predict the thermal design space in which the cell will or will not experience thermal runaway. By combining all thermal processes contributing to thermal runaway in a single parameter, this work contributes towards a unified understanding of thermal runaway, and provides the fundamental basis for design tools for safe, high-performance Li-ion batteries. [ABSTRACT FROM AUTHOR]

Conjugate heat transfer involving convection and conduction in a fluid flow and a solid body in contact with each other occurs commonly in engineering applications. While analytical solutions for individual convection and conduction problems are relatively easier, it is a lot more challenging to solve the combined conjugate heat transfer problem. In this paper, an iterative method is developed for analytically solving conjugate heat transfer problems. Based on an initial assumption of the temperature field at the solid–fluid interface, the temperature distributions in the fluid and solid body are determined by separately solving the governing energy conservation equations in the two domains. These solutions are used to improve the initial assumption of the interface temperature until convergence. It is found that only a few iterations of this process are needed for convergence. Temperature fields computed from this analytical approach are found to be in good agreement with finite element simulation results. The iterative analytical approach is used to solve two technologically relevant problems related to internal and external flows. Given the general nature of the iterative approach, results from this paper may be helpful in solving a variety of conjugate heat transfer problems. [ABSTRACT FROM AUTHOR]

Recent studies from our lab have demonstrated that intermittent high-fat diet access reduces alcohol drinking in rats. However, it was unclear if caloric overload, palatability, or diet itself triggered reduced alcohol drinking. It is also unknown if a similar paradigm could reduce relapse-like alcohol drinking. The presented study tested the hypothesis that acute intermittent palatable diet (PD) access would rescue relapse-like drinking and palatability, but not diet itself contributes to reduced drinking. Male Long Evans rats received six-weeks intermittent or chronic chow (controls) or PDs (high-fat diet, high-sugar diet) exposure, and alcohol testing occurred following PDs suspension. Alcohol intake was not significantly different among groups in either condition, suggesting that diet itself did not impact alcohol drinking. A subset of these rats received two-weeks intermittent PDs (Int-PDs) exposure and alcohol testing reinitiated while Int-PDs access continued. Alcohol intake significantly escalated (~137% compared to baseline; alcohol deprivation effect) in the chow controls, whereas it remained unchanged in PD groups. These data demonstrate the critical importance of acute intermittent PDs availability and its protective effect in relapse-like drinking. To assess the contribution of palatability in reduced alcohol drinking, a separate group of rats received two-weeks intermittent high-sugar diet (Int-HSD) or saccharin (Int-SAC) access and tested for alcohol drinking while Int-HSD/SAC continued. Alcohol drinking significantly decreased (~30%) in both HSD and SAC groups compared to the controls. These data identify the critical parameters by which acute intermittent PD access reduces alcohol drinking and could have important therapeutic implications in the management of alcoholism. [ABSTRACT FROM AUTHOR]

Abstract: Mesenchymal stem cells (MSCs) although used for bone tissue engineering are limited by the requirement of isolation and culture prior to transplantation. Our recent studies have shown that biomaterial implants can be engineered to facilitate the recruitment of MSCs. In this study, we explore the ability of these implants to direct the recruitment and the differentiation of MSCs in the setting of a bone defect. We initially determined that both stromal derived factor-1alpha (SDF-1α) and erythropoietin (Epo) prompted different degrees of MSC recruitment. Additionally, we found that Epo and bone morphogenetic protein-2 (BMP-2), but not SDF-1α, triggered the osteogenic differentiation of MSCs in vitro. We then investigated the possibility of directing autologous MSC-mediated bone regeneration using a murine calvaria model. Consistent with our in vitro observations, Epo-releasing scaffolds were found to be more potent in bridging the defect than BMP-2 loaded scaffolds, as determined by computed tomography (CT) scanning, fluorescent imaging and histological analyses. These results demonstrate the tremendous potential, directing the recruitment and differentiation of autologous MSCs has in the field of tissue regeneration. [Copyright &y& Elsevier]

Visual analogue scales (VAS) have commonly been used to assess appetite in children 8 years and older; however, these tools have been considered unreliable for children 7 years old and under. The objective of this pilot study was to develop a picture-based appetite assessment (PBAA) tool for children aged 4-10 years and pilot test it compared to a VAS-based appetite assessment. The study hypothesis was that the PBAA scores would decrease following the consumption of an ad libitum snack compared to the scores in the fasted state in children 4 to 10 years old; furthermore, there would be a good level of agreement (intraclass correlation coefficients >0.75) between the appetite scores by the PBAA and VAS tools in children aged 8 years or older. At Visit 1, in a fasted state, all children (n = 15) completed the PBAA. Children who were 8-10 years old (n = 8) also completed the VAS-based appetite assessment. Then, an ad libitum snack was provided, and appetite assessments were repeated at 5-, 30- and 60-minutes post-snack. The same assessments were completed at visit 2 pre (fasting)- and post-consumption of a snack containing 25% of the amount consumed at visit 1 (limited snack). PBAA scores were different across time (P <.001) and between types of meal (ad libitum vs limited snack) (P =.015) in all children. A good agreement between the PBAA and VAS scores at 30 and 60 minutes after both types of meal was found (intraclass correlation coefficients >0.75). The PBAA tool was able to detect expected changes in appetite sensations and was in good agreement with the VAS instrument. [ABSTRACT FROM AUTHOR]

Advanced Air Mobility (AAM) represents a collaborative vision shared by NASA, regulatory agencies, and global industry leaders, aimed at establishing a robust and reliable air transportation ecosystem, which is expected to facilitate safe and efficient movement of both people and cargo within urban, suburban, and regional environments. This paper presents a holistic review and analysis encompassing various aircraft designs, including different propulsion system designs and architectures (electric, hybrid electric, turboelectric, etc.), for different AAM aircraft applications, and state-of-the-art air traffic management, cybersecurity, and infrastructure strategies. Recent academic and industry literature on these aspects is critically reviewed and summarized, and a compilation of the aircraft models currently in development is also provided. The aircraft designs are categorized into a set of core groups, which include lift + cruise, tilt-wing, tiltrotor, multirotor, and rotorcraft, to analyze the existing literature systematically. For each of these core groups, literature on different propulsion system designs and architectures is reviewed and analyzed. Next, these core groups, including their variations based on propulsion system designs and architectures, are analyzed through a set of evaluation lenses. This provides a comprehensive insight into their respective strengths, weakness, and gaps in design considerations. The identified lenses include range and payload, performance, environmental impact, feasibility, traffic and infrastructure, noise, vehicle safety, and cybersecurity. Finally, directions for future research in AAM aircraft and overall ecosystem development are identified. In general, a more in-depth, quantitative analysis on the various evaluation lenses identified in this study and appropriate consideration to all these evaluation lenses at the design and development stage are highly recommended. This type of holistic approach will drive AAM aircraft designs towards convergence and help build an efficient, affordable, and sustainable AAM ecosystem. • A compilation of state-of-the-art AAM aircrafts developed by the industry. • Comprehensive evaluation of various AAM aircraft designs, including rotor configuration and propulsion architectures. • Evaluation of the key components of the overall AAM ecosystem specific to vehicle operation. • Discussion on the research outlook for all the evaluation lenses analyzed in the study. [ABSTRACT FROM AUTHOR]