bluuebunny/crossref_metadata_2025 huggingface dataset:
Non‐selective dampening of the host immune response after hepatitis C clearance and its association with circulating chemokine and endotoxin levels
Authors: Quinn Gabriella , Ali Rabab O. , Zhang Grace Y. , Hill Kareen , Townsend Elizabeth , Umarova Regina , Chakraborty Moumita , Ahmad Maleeha F. , Gewirtz Meital , Haddad James , Rosenzweig Sergio , Rampertaap Shakuntala , Schoenfeld Megan , Yang Shanna , Koh Christopher , Levy Elliot , Kleiner David E. , Etzion Ohad , Heller Theo
Published: September 2023

Background & Aims

Direct‐acting antiviral (DAA) therapy has revolutionized treatment for the hepatitis C virus (HCV). While DAA therapy is common, little is known about the intrahepatic immunological changes after sustained virologic response (SVR). We aim to describe transcriptional alterations of the gut microbiome and the liver after SVR.

Methods

Twenty‐two HCV patients were evaluated before and 9 months after 12 weeks of sofosbuvir/velpatasvir treatment. All achieved SVR. A liver biopsy, portal blood (direct portal vein cannulation), peripheral blood and stool samples were obtained. RNA‐seq and immunofluorescent staining were performed on liver biopsies. RNA‐seq and 16S rRNA metagenomics were performed on stool.

Results

Differential expression within liver transcription showed 514 downregulated genes (FDR q < .05; foldchange > 2) enriched in inflammatory pathways; of note, GO:0060337, type 1 IFN signalling (p = 8e‐23) and GO:0042742, defence response to bacterium (p = 8e‐3). Interestingly, microbial products increased in the portal blood and liver after SVR. Due to the increase in microbial products, the gut microbiome was investigated. There was no dysbiosis by Shannon diversity index or Bacteroides/Firmicutes ratio. There was a differential increase in genes responsible for bacterial lipopolysaccharide production after SVR.

Conclusions

The decrease in the antiviral interferon pathway expression was expected after SVR; however, there was an unanticipated decrease in the transcription of genes involved in recognition and response to bacteria, which was associated with increased levels of microbial products. Finally, the alterations in the function of the gut microbiome are a promising avenue for further investigation of the gut‐liver axis, especially in the context of the significant immunological changes noted after SVR.
Aquinas on the Nature of Lying
Authors: Brower Jeffrey E.
Published: September 2023

Aquinas's views about the morality of lying are well known and often discussed by commentators. But his views about the nature of lying have yet to receive the attention they deserve. In this article, I take some of the first steps necessary to correct this state of affairs by clarifying and offering a limited defense of the account of lying that Aquinas presents in in his Summa Theologiae—more specifically, in that portion of it known as the treatise on truth (Part 2-2, Questions 109–113).
Designing a youth‐led Dialogue Forum tool: The CO‐CREATE experience
Authors: Ulloa Manuela Aguirre , Nesrallah Samantha , Shafafi Pardis , Lamar Angel , Gonçalves Pedro Côrte‐Real , Gonçalves Mafalda , Nylander Karoline Steen , Luszczynska Aleksandra , Lien Nanna , Bergstrøm Elin , Rutter Harry , Marki Henriette , Klepp Knut‐Inge , Bouillon Claire
Published: September 2023

While obesity prevention represents an established field of research, the inclusion of young people, who are regularly cited as an important priority group, are rarely actioned in long‐term studies. This paper focuses on the development of a dialogue tool intended to tackle this issue, engaging, and eliciting insights on the theme of obesity prevention, by young people and for young people. As part of the CO‐CREATE project, this tool was co‐developed by designers, public health, and youth participation experts, researchers, and young people. Co‐creation is a key methodology in the design of the dialogue tool, as young people were involved in all stages of the development process. This paper elaborates on the process of co‐designing a dialogue tool that helps explore obesity prevention policy ideas from multiple perspectives, and describes the design principles that informed the process and the final versions of the tool. The purpose of the Dialogue Forum tool is for youth to engage policymakers and other relevant stakeholders to discuss and refine co‐created and youth‐initiated ideas for healthier food and physical activity environments. We analyze how specific design principles were integrated into different prototypes and the value of this within the project and the field.
Weak texture remote sensing image matching based on hybrid domain features and adaptive description method
Authors: Yang Wupeng , Yao Yongxiang , Zhang Yongjun , Wan Yi
Published: September 2023

Weak texture remote sensing image (WTRSI) has characteristics such as low reflectivity, high similarity of neighbouring pixels and insignificant differences between regions. These factors cause difficulties in feature extraction and description, which lead to unsuccessful matching. Therefore, this paper proposes a novel hybrid‐domain features and adaptive description (HFAD) approach to perform WTRSI matching. This approach mainly provides two contributions: (1) a new feature extractor that combines both the spatial domain scale space and the frequency domain scale space is established, where a weighted least square filter combined with a phase consistency filter is used to establish the frequency domain scale space; and (2) a new log‐polar descriptor of adaptive neighbourhood (LDAN) is established, where the neighbourhood window size of each descriptor is calculated according to the log‐normalised intensity value of feature points. This article prepares some remote sensing images under weak texture scenes which include deserts, dense forests, waters, ice and snow, and shadows. The data set contains 50 typical image pairs, on which the proposed HFAD was demonstrated and compared with state‐of‐the‐art matching algorithms (RIFT, HOWP, KAZE, POS‐SIFT and SIFT). The statistical results of the comparative experiment show that the HFAD can achieve the accuracy of matching within two pixels and confirm that the proposed algorithm is robust and effective.
Insider‐allies: The precarious politics of men in identity‐fluid feminism
Authors: Hartless Jaime
Published: September 2023

Academic and activist conversations about the position of men in feminism often operate under the assumption that women are the movement's key beneficiaries and men are privileged outsiders lending their support. I use 59 interviews from a broader project on feminist and LGBTQ+ activism in the United States to illustrate how men's orientation to feminism is shaped by whether social movement organizations adopt what I call woman‐centered or identity‐fluid politics. While woman‐centered politics treat men as allies whose intentions must be vetted by women, identity‐fluid feminism imagines men as insiders with their own independent investment in the movement. I argue that the tension between these two models of identity politics gives men a liminal “insider‐ally” position within feminism. Although feminist men are given a tentative authority to speak for the movement, the persistence of woman‐centered understandings of feminism means men's insider status is contested, especially when they dominate feminist spaces, compromise women's sense of safety, and seek leadership.
Thinking of threats: Economic threat appraisals and health threat appraisals predict differential racial attitudes during COVID‐19
Authors: Gallagher Natalie M. , Daley Jordan S. , Bodenhausen Galen V.
Published: September 2023

We examined whether perceptions of the health and economic threats posed by COVID‐19 predict different patterns of intergroup attitudes, using data gathered during the early phase of the pandemic. Using data from 1339 geographically and politically diverse White US residents, we show that subjective economic threat predicted general anti‐outgroup attitudes, while subjective health threat predicted negative attitudes towards both Asian and Latinx (“stereotypically foreign”) outgroups but not towards other outgroups. Among 303 geographically and politically diverse Black US residents, the pattern instead suggested that threat (regardless of type) was associated with reduced evaluative differentiation between racial ingroups and outgroups.
ESBL‐producing Enterobacteriaceae in a rural Rwandan community: Carriage among community members, livestock, farm products and environment
Authors: Geuther Nadja , Mbarushimana Djibril , Habarugira Felix , Buregeya Jean Damascene , Kollatzsch Mandy , Pfüller Roland , Mugabowindekwe Maurice , Ndoli Jules , Mockenhaupt Frank P.
Published: September 2023

Objectives

Extended‐spectrum beta‐lactamase‐producing Enterobacteriaceae (ESBL‐PE) are spreading globally. However, respective data from African communities including livestock and environmental specimens are rare. In a rural community of southern Rwanda, we assessed intestinal carriage of ESBL‐PE among residents and livestock as well as presence in household specimens and examined associated factors.

Methods

Samples of humans and livestock (both rectal swabs), soil, water, vegetables and animal products were collected within 312 community households in Sovu, Southern Rwanda. Specimens were screened for ESBL‐PE on chromogenic agar, and susceptibility to common antibiotics was determined by disc diffusion assays. Socio‐demographic information was collected with questionnaires focusing on the socio‐economic background, alimentation, living conditions, hygiene measures and medical history of the participants.

Results

Data and specimens from 312 randomly selected households including 617 human beings, 620 livestock and of approximately each 300 kitchen vegetables, animal products, soil and drinking water were analysed. Overall, 14.8% of 2508 collected samples were positive for ESBL‐PE; figures were highest for humans (37.9%) and livestock (15.6%), lower for vegetables (3.8%) and animal products (3.3%), and lowest for soil (1.6%) and water (0.6%). Most detected ESBL‐PE were Escherichia coli (93.5%) in addition to Klebsiella pneumoniae (6.5%). Cross‐resistance to ampicillin‐sulbactam, ciprofloxacin and co‐trimoxazole was common. Logistic regression identified increasing age, another ESBL‐PE positive household member, prolonged time for fetching water, current diarrhoea and the ability to pay school fees as independent predictors of intestinal ESBL‐PE carriage among community members.

Conclusions

ESBL‐PE carriage is common in a rural Rwandan farming community. Carriage in livestock is not associated with human carriage. Associated factors suggest few addressable risk factors. The data indicate that in southern Rwanda, ESBL‐PE are no longer primarily hospital‐based but circulate in the community.
Insights into the diversity of blood donation practice across Asia: How blood collection agencies adapt donor criteria and processes to their population
Authors: Fung Yoke‐Lin , Alcantara Ramir Moreno , Cavalli Leonardo Brereton , Chen Jen‐Wei , Chen Yun‐Yuan , Donkin Rebecca , Kupatawintu Pawinee , Kwon So‐Yong , Lee Cheuk‐Kwong , Nadarajan Veera Sekaran , Namjil Erdenebayar , Bat Solongo , Odajima Takeshi , Sachdev Suchet , Siswishanto Rukmono , Tadsomboon Sahit , Sharma Ratti Ram , Triyono Teguh , Tsuno Nelson‐Hirokazu
Published: September 2023

Background and Objectives

Securing an adequate blood supply relies on accurate knowledge of blood donors and donation practices. As published evidence on Asian populations is sparse, this study aims to gather up‐to‐date information on blood donors and donation practices in Asia to assist planning and strategy development.

Materials and Methods

Ten blood collection agencies (BCAs) provided 12 months' data on donors who met eligibility criteria or were deferred, as well as details of their donation practices. Body mass index and blood volumes were calculated and analysed.

Results

Data on 9,599,613 donations and 154,834 deferrals from six national and four regional BCAs revealed varied donation eligibility and collection practices. Seven used haemoglobin (Hb) criteria below the World Health Organization anaemia threshold. Seven accepted donors weighing <50 kg. Data collection on the weight and height of donors and on deferrals was inconsistent, often not routine. Deferred donors appear to weigh less, with corresponding lower estimated blood volume.

Conclusion

The diversity in eligibility criteria and donation practices reflects each BCA's strategy for balancing donor health with securing an adequate blood supply. Use of lower Hb criteria substantiate their appropriateness in Asia and indicate the need to define Hb reference intervals relevant to each population. We encourage routine gathering of donor weight and height data to enable blood volume estimation and local optimization of donation volumes. Blood volume estimation formulae specific for the Asian phenotype is needed. Information from this study would be useful for tailoring donation criteria of Asian donors around the world.
Interval groups related to finite Coxeter groups Part II
Authors: Baumeister Barbara , Holt Derek F. , Neaime Georges , Rees Sarah
Published: September 2023

We provide a complete description of the presentations of the interval groups related to quasi‐Coxeter elements in finite Coxeter groups. In the simply laced cases, we show that each interval group is the quotient of the Artin group associated with the corresponding Carter diagram by the normal closure of a set of twisted cycle commutators, one for each 4‐cycle of the diagram. Our techniques also reprove an analogous result for the Artin groups of finite Coxeter groups, which are interval groups corresponding to Coxeter elements. We also analyse the situation in the non‐simply laced cases, where a new Garside structure is discovered. Furthermore, we obtain a complete classification of whether the interval group we consider is isomorphic or not to the related Artin group. Indeed, using methods of Tits, we prove that the interval groups of proper quasi‐Coxeter elements are not isomorphic to the Artin groups of the same type, in the case of when is even or in any of the exceptional cases. In Baumeister et al. (J. Algebra 629 (2023), 399–423), we show using different methods that this result holds for type for all .
Direct Numerical Simulation of a High-Pressure Turbine Stage: Unsteady Boundary Layer Transition and the Resulting Flow Structures
Authors: Wang Taiyang , Zhao Yaomin , Leggett John , Sandberg Richard D.
Published: September 2023

In the present study, we investigate the unsteady boundary layer transition based on the direct numerical simulation database of a high-pressure turbine (HPT) stage (Zhao and Sandberg, 2021, High-Fidelity Simulations of a High-Pressure Turbine Stage: Effects of Reynolds Number and Inlet Turbulence, ASME Turbo Expo 2021, Paper No. GT2021-58995), focusing on the transition mechanisms on the rotor blade, affected by the incoming periodic wakes and the background freestream turbulence (FST). On the basis of the fully resolved flow fields, we provide detailed analysis of the flow structures responsible for the transition, and two distinctive transition paths have been identified. The first path is the typical bypass transition via the instability of Klebanoff streaks, which happens when the transition region is not directly affected by the wake. The suction-side boundary layer is disturbed at the leading edge, resulting in the formation of streamwise streaks. These streaky structures endure varicose instability in the region with adverse pressure gradient (APG), then quickly break down into turbulent spots, which then evolve into fully turbulent flow. The other transition path is a consequence of the direct interaction between the wake structures and the blade boundary layer, when the wake apex starts to affect the transitional region. To be specific, the wake structures directly interact with the separation bubble in the APG region, causing sudden breakdown into turbulence. A calmed region is found to follow the wake-induced turbulent boundary layer. It is observed that the recovery to a calmed region can be impacted by the FST, as the calmed region in case with no FST is much longer compared to cases with stronger FST.
Experimental and Numerical Investigations on Flexible Paraffin/Fiber Composite Phase Change Material
Authors: Zhang Qi , Li Yanfang , Wu Xuehong , Zhang Xueling , Wang Yanling , Song Jun , Liu Chongyang
Published: September 2023

A flexible paraffin/hollow fiber phase change composite was prepared using a simple impregnation method, and the thermal-release performance of a piece of woven paraffin/hollow fiber rectangular blocks was systematically investigated using experimental and numerical methods. The experimental results of the thermal-release performance were highly consistent with the numerical results. Consequently, the thermal-release performance, including the available energy and solidification time, of the paraffin/hollow fiber with different melting temperatures, mass fractions (corresponding to the enthalpy), specific heat, and thermal conductivity were numerically investigated. The available energy of the paraffin/hollow fiber completely depends on the mass fraction of the paraffin. The solidification time mainly depends on the mass fraction of the paraffin and secondarily on the thermal conductivity, while the specific heat has little effect on the solidification time. Therefore, the thermal-release performance of the paraffin/hollow fiber could be optimized through numerical simulation by altering the solidification temperature, mass fraction, thermal conductivity, and specific heat.
ImpersonatAR: Using Embodied Authoring and Evaluation to Prototype Multi-Scenario Use Cases for Augmented Reality Applications
Authors: Wu Meng-Han , Ipsita Ananya , Huang Gaoping , Ramani Karthik , Quinn Alex
Published: September 2023

Prototyping use cases for augmented reality (AR) applications can be beneficial to elicit the functional requirements of the features early-on, to drive the subsequent development in a goal-oriented manner. Doing so would require designers to identify the goal-oriented interactions and map the associations between those interactions in a spatio-temporal context. Pertaining to the multiple scenarios that may result from the mapping, and the embodied nature of the interaction components, recent AR prototyping methods lack the support to adequately capture and communicate the intent of designers and stakeholders during this process. We present ImpersonatAR, a mobile-device-based prototyping tool that utilizes embodied demonstrations in the augmented environment to support prototyping and evaluation of multi-scenario AR use cases. The approach uses: (1) capturing events or steps in the form of embodied demonstrations using avatars and 3D animations, (2) organizing events and steps to compose multi-scenario experience, and finally (3) allowing stakeholders to explore the scenarios through interactive role-play with the prototypes. We conducted a user study with ten participants to prototype use cases using ImpersonatAR from two different AR application features. Results validated that ImpersonatAR promotes exploration and evaluation of diverse design possibilities of multi-scenario AR use cases through embodied representations of the different scenarios.
A Simulation Study of Factors Affecting Cooling Performance of a Fan Wall-Cooled Data Center
Authors: Ling Wei , Bi Zhaoyang , Chen Tailian
Published: September 2023

In this paper, numerical study of airflow in high-density data center with fan wall is conducted to study the factors affecting the cooling performance of high-density data centers. The factors considered are air outlet layout, orifice plate setting, and closed cold aisle. The total heat load in the computer room is 470 kW, and the single frame is 7 kW. The results show that there is no significant difference between installing the orifice plate and not installing the orifice plate. When the porosity of the orifice plate is less than 40 %, the airflow uniformity after the orifice plate is obviously improved, but the airflow path is greatly blocked, resulting in the inlet temperature of the middle and rear cabinets exceeding the thermal safety range. The high porosity of orifice plate has little effect on improving refrigeration effect. Changing the layout of the vent is a measure that has a significant impact on airflow management. The vertical cold aisle arrangement of the vent can make the airflow path more reasonable. The addition of partially closed cold aisle greatly reduces the mixing of hot and cold air, and the utilization rate of outdoor low-temperature cooling can be improved by increasing the supply air temperature, thereby reducing carbon emissions and further moving towards a low-carbon data center.
Numerical Study of Solar Receiver Tube With Modified Surface Roughness for Enhanced and Selective Absorptivity in Concentrated Solar Power Tower
Authors: Hatcher Shawn , Farias Mathew , Li Jianzhi , Li Peiwen , Xu Ben
Published: September 2023

Concentrated solar power (CSP) is a reliable renewable energy source that is progressively lowering its cost of energy. However, the heat loss due to reflected and emitted radiation hinders the maximum achievable thermal efficiency for solar receiver tubes on the solar tower. Current solar selective coatings cannot withstand the high temperatures that come with state-of-the-art CSP towers often needing to be recoated soon after initial operation. We intend to use Inconel 718 with different additive manufacturing (AM) practices to construct surfaces that allow for more light-trapping to occur. By adjusting printing parameters, we can tailor a surface to allow for more absorption while diminishing emitted radiation heat loss. By using COMSOL Multiphysics, we can generate these theoretical surfaces to emulate a printed surface, and using the coupled Multiphysics we can simulate how the surface dictates radiation properties. Our results show that by having a rougher surface we can enhance the absorptivity of Inconel 718 (IN718) by 38.8%. We expect this work to transform how solar absorber tubes are manufactured without using selective coatings and supplement the US Department of Energy (DOE) 2030 SunShot Initiative.
Feasibility of High Temperature Concentrated Solar Power for Cogeneration of Electricity and Hydrogen Using Supercritical Carbon Dioxide Receiver Technology
Authors: Khormi Nader A. , Fronk Brian M.
Published: September 2023

The objective of this study is to evaluate the feasibility of cogeneration of electricity and hydrogen using a high temperature, concentrated solar power central receiver with supercritical carbon dioxide as the working fluid. Carbon dioxide is heated directly in a high efficiency receiver to a temperature of 720°C, which then provides thermal input in series to a supercritical carbon dioxide (sCO2) Brayton cycle for producing electricity and then to a thermochemical hydrogen production cycle. Three different methods of producing hydrogen are examined: the 4-step copper-chlorine (Cu-Cl) thermochemical cycle, the hybrid sulfur (HyS) thermochemical cycle, and two different electrolyzers: the alkaline electrolyzer and the polymer exchange membrane electrolyzer. Simulations developed in Aspen Plus were used to estimate the thermochemical hydrogen production efficiency, while the solar receiver and sCO2 Brayton cycle performance were based on results of prior work. The initial results show that the overall solar-to-electricity and H2 efficiencies for the Cu-Cl cycle, hybrid sulfur cycle, alkaline electrolyzer, and polymer exchange membrane electrolyzer are 39.6%, 26.1%, 29.6%, and 22.8%, respectively. These systems’ hydrogen capacities are 864, 715, 524, and 403 kg/h, respectively, for an equivalent sCO2 Brayton cycle.
Thermomechanical Stress and Creep-Fatigue Analysis of a High-Temperature Prototype Receiver for Heating Particles
Authors: Carter Matt , Korba David , Martinek Janna , Ma Zhiwen , Li Like
Published: September 2023

This work presents a three-dimensional (3D) thermomechanical model of a prototype-scale enclosed light trapping solar receiver for heating particles. Results of the thermoelastic model are used to estimate receiver lifetime under maximum flux conditions. A computational fluid dynamics (CFD) model is first developed to predict the temperature fields in a multi-panel assembly under steady operating conditions. Solar flux distributions on the receiver are obtained from the software package SolTrace and applied to the 3D thermal model. The subsequent particle heating is captured through a simplified 1D energy balance. Panel reradiation is considered through a surface-to-surface radiation model and natural convection loss to the surrounding air is captured in a representative fluid domain surrounding the receiver. The resulting temperature fields from the CFD analysis are used as inputs for a thermoelastic mechanical model with representative boundary conditions. With the resultant temperature and stress fields, a creep-fatigue damage and lifetime analysis is performed using the linear damage accumulation (LDA) theory. The Manson-Coffin formula and Larson Miller correlation are used to calculate the fatigue and creep, respectively. A maximum damage (corresponding to a 30-year service life) is defined for design assessment. The model was first developed and verified in detail by comparing with published results in the literature (temperature and stress profiles and distributions, and creep/fatigue damage fractions) for tubular solar receivers with supercritical carbon dioxide as the working fluid. It was then implemented to model a planar-cavity receiver with various design parameters. Specifically, three different design geometries are considered, and the results show that a maximum temperature of approximately 1200 K could be reached for each design with the given incident solar flux, with the main difference being the distribution of these temperatures. Preliminary resulting stresses for the small-scale prototype without design optimization vary from 20 MPa to 250 MPa for each design, with the maximum stresses occurring on the front face and concave geometry on the side of the panel. In future work, the developed methodology shown here will be applied to analyze a full-scale (50–150 MWth) receiver.
Urban Scale Cooling Load Prediction of High-Rise Buildings in a Hot and Arid Climate
Authors: Ahmed Omar , Moujahed Majd , Sezer Nurettin , Wang Liangzhu (Leon) , Hassan Ibrahim Galal
Published: September 2023

This study employs an archetype-based modeling approach to estimate and analyze the urban scale cooling load profile of high-rise buildings in the Marina district of Lusail City, Qatar. Since the Marina district is a newly built district, the building typology and geometric characteristics are considered the main criteria for the selection of representative archetypes of the district. Three high-rise building archetypes are developed using EnergyPlus software to represent the available building stocks in the district, which are residential, commercial, and mixed-use. Required data for the input parameters are collected from various sources such as the Lusail City GSAS 2 Star Rating Guidelines, which define the minimum requirements in the region, ASHRAE 90.1, and ASHRAE 62.1 standards, along with user surveys when available. Detailed cooling load profiles of the three building archetypes are obtained in EnergyPlus, which enables aggregating the cooling loads to obtain the cooling load profile of the Marina district at various time resolutions. The cooling load profiles obtained after the simulation of each building archetype model in EnergyPlus are validated with real building cooling loads measured in the case study area. The developed cooling load profiles in this study can inform district cooling facilities for an optimal design and operation of the plant, reveal the energy-saving potential of buildings, and aid in defining cost allocations or billing strategies for end users without the need for the installation of zone-level submeter to each apartment unit. This study further contributes to the establishment of a representative building archetype library for hot and arid climate zones. Thus, the building archetype models produced for the Marina district in this study are also applicable to other regions with similar building types and climatic characteristics.
Heat Transfer of Supercritical CO2 Near the Critical Condition Inside a Microchannel
Authors: Ahmed Pranzal , Parahovnik Anatoly , Peles Yoav
Published: September 2023

Carbon dioxide (CO2) is increasingly being used as a highly efficient, environmentally friendly and sustainable refrigerant/heat transfer fluid. Because of its high specific heat and cooling capacity, supercritical CO2 has the potential to be widely used in a range of applications, such as power generation and thermal management of data centers/electronics. Near the critical condition, the thermo-physical properties undergo drastic changes, which can affect the heat transfer performance. Thus, knowledge about the heat transfer process in the supercritical phase of CO2 is necessary.

In this experimental study, the heat transfer characteristics of supercritical CO2 near the critical condition in a microchannel were studied. An experimental setup, microfluidic devices with embedded resistance temperature detectors (RTDs), and a LabVIEW data acquisition system (DAQ), were used to obtain a range of variables, such as temperature, pressure, heat flux, and mass flux. Heat transfer coefficients (HTC) were calculated for different flow conditions (i.e., mass fluxes and pressures). In addition, the effect of the downstream position was discussed. The independent variables included mass fluxes ranging from 1825 kg/m2.s to 8080 kg/m2.s, reduced pressure (p/pR) ranging from 1.02 to 1.143, and heat fluxes up to 98 W/cm2.
Remote Thermal Measurements With Regression of Acoustic Emissions
Authors: Dunlap Christy , Pandey Hari , Marsh Jackson , Weems Ethan , Hu Han
Published: September 2023

Real-time thermal monitoring and regulation are critical to the mitigation of thermal runaways and device failures in two-phase cooling systems. Compared to conventional approaches that rely on the Joule effect, thermal gradient or transverse thermoelectric effect, acoustic emission (AE)-based remote sensing is more promising for robust and non-intrusive thermal monitoring. Nevertheless, due to the high stochasticity and noise of acoustic signals, existing implementations of AE in thermal systems have been limited to qualitative state monitoring. In this paper, we present a technology for real-time heat flux quantification during two-phase cooling by coupling acoustic sensing using hydrophones and condenser microphones and regression-based machine learning frameworks. These frameworks integrate a fast Fourier transform feature extraction algorithm with regressors, i.e., Gaussian process regressor and multilayer perceptron regressor for heat flux predictions. The acoustic signals and heat fluxes are collected from pool boiling tests under transient heat loads. It is shown that both hydrophone and condenser microphone signals are successful in predicting heat flux. Multiple models are trained and compared some using only one form of acoustic data while others combine both acoustic types (i.e., hydrophone and microphone) in fusion ML models (i.e., early, joint, late). The models using only hydrophone data are shown to perform better than the models using only microphone data. Also, some forms of fusion are shown to have better performance than either of the single input data type models. This AE-ML technology is demonstrated for accurate heatflux quantification. As such, this work will not only lead to a light, low-cost, and non-contact thermal measurement technology but also a new perspective for the physical explanation of bubble dynamics during boiling.
Effect of Modified Fin Geometries on the Effectiveness Of a Phase Change Material Heat Sink
Authors: Jones Austin , Darabi Jeff
Published: September 2023

Finned heatsinks have long been used as a passive means to cool electronic components. However, the demand for smaller, high power density products, packaged near one another, has led to the need for a different solution. One such solution is to utilize a material such as paraffin wax and its high latent heat as a phase change material (PCM). A material with high latent heat allows the components to be held at a lower temperature for a period time until all the PCM has melted. The biggest drawback of these materials is their low thermal conductivity, which does not effectively transfer the heat away from the heat source. This paper presents the experimental and numerical results of various fin geometries effectiveness at overcoming this issue. A 15.24cm × 7.62cm × 5.08cm aluminum housing was fabricated and commercially available fins were modified and inserted into the housing. Pure paraffin wax was melted and poured into the enclosure to act as the phase change material. A heater was attached to the bottom of the housing. Temperature and melt time data was collected. A computational study was then conducted using ANSYS Fluent and the results of the experiment were used to validate the model. The model was then used to study the effects of different fin geometries and heat loads.
Volumetric Additive Manufacturing With 3D Point Cloud Projection and Single-Photon Nonlinear Polymerization
Authors: Jakkinapalli Aravind , Wen Sy-Bor
Published: September 2023

Volumetric additive manufacturing allows simultaneously patterning an entire 3D object by irradiating a photosensitive resin with UV to near-infrared light. An obvious advantage of volumetric additive manufacturing is its capability to construct 3D objects without support structures. Also, volumetric additive manufacturing allows fast 3D fabrication compared with layer-by-layer stacking type 3D fabrication. However, demonstrated volumetric additive manufacturing, such as computed axial lithography, has a resolution limited to ∼50 μm. This study shows that enhanced 3D point cloud projection and single-photon nonlinear polymerization can be used as a new volumetric additive manufacturing method to achieve deep micron-level resolution. The enhanced 3D point cloud projection is achieved with a phase-modulated spatial light modulator (SLM) that can precisely control the diffraction of mini-rays used to generate voxels in the 3D point cloud projection. Consistent deep micron level voxel sizes with minimum side lobes were achieved by randomizing the azimuth and polar angles of the mini-rays from the SLM to diminish unwanted constructive interferences of the mini-rays except at the designed voxel locations. High spatial resolution volumetric additive manufacturing can be achieved by delivering the compressed 3D point clouds from the enhanced 3D point cloud projection with shapes mimicking the desired 3D structures in photopolymers supporting single-photon nonlinear polymerization (e.g., SU-8 with dissolved oxygen as inhibitors). Numerical algorithms for generating 3D point clouds with the enhanced 3D point cloud projection having deep micron resolution and preliminary results of generating simple 3D geometries through the new 3D point cloud projection and single-photon nonlinear polymerization are presented in this study.
The Effect of a Pulsed Flow Inlet on Vacuum Membrane Distillation Performance
Authors: Caspar Justin , Xue Guanyang , Oztekin Alparslan
Published: September 2023

2D Large Eddy Simulations (LES) were run to determine the effect of multiple hydrodynamic optimizations on a vacuum membrane distillation module (VMD). The first optimization considered is a morphology change from a straight channel wall to a sinusoidal one. The second change is a pulsed mass flow at the inlet — similar to adding turbulent energy to the incoming flow. Two different Reynolds/Strouhal numbers were considered, 1,500 (0.24) and 750 (0.48). Three pulsation amplitudes were considered 15%, 25%, and 50% of the base inlet velocity. Simulation results show that by only having one performance increase, going from flat to wiggly, the flux increased by 23% of the baseline value, while both the wiggly channel with pulsations showed a flux increase of 31% of the baseline value. The increase is because the vortex shedding in the wiggly channel reduces temperature polarization near the membrane surface. As pulsations are introduced into the wiggly channel, the flow separates earlier, and more of the channel experiences mixing vortices. In the flat sheet case with no geometric alterations, there is no flow separation regardless of a pulsed inlet.
Isotropic plasma-thermal atomic layer etching of superconducting titanium nitride films using sequential exposures of molecular oxygen and SF6/H2 plasma
Authors: Hossain Azmain A. , Wang Haozhe , Catherall David S. , Leung Martin , Knoops Harm C. M. , Renzas James R. , Minnich Austin J.
Published: September 2023

Microwave loss in superconducting TiN films is attributed to two-level systems in various interfaces arising in part from oxidation and microfabrication-induced damage. Atomic layer etching (ALE) is an emerging subtractive fabrication method which is capable of etching with angstrom-scale etch depth control and potentially less damage. However, while ALE processes for TiN have been reported, they either employ HF vapor, incurring practical complications, or the etch rate lacks the desired control. Furthermore, the superconducting characteristics of the etched films have not been characterized. Here, we report an isotropic plasma-thermal TiN ALE process consisting of sequential exposures to molecular oxygen and an SF6/H2 plasma. For certain ratios of SF6:H2 flow rates, we observe selective etching of TiO2 over TiN, enabling self-limiting etching within a cycle. Etch rates were measured to vary from 1.1 Å/cycle at 150°C to 3.2 Å/cycle at 350°C using ex situ ellipsometry. We demonstrate that the superconducting critical temperature of the etched film does not decrease beyond that expected from the decrease in film thickness, highlighting the low-damage nature of the process. These findings have relevance for applications of TiN in microwave kinetic inductance detectors and superconducting qubits.
Moving source depth estimation in deep ocean direct arrival zone with a horizontal line array
Authors: Zhu Feilong , Li Fenghua , Zhang Yanjun , Zhang Bo , Li Wen , Wang Tongchen
Published: September 2023

The received sound intensity of bottom-mounted line array varies as the submerged sound source moves in the direct arrival region, which resulting from interference between the direct and surface-reflected propagation paths, modulates with the target depth. In this work, the Fourier integral method from McCargar and Zurk [J. Acoust. Soc. Am. 133, EL320–EL325 (2013)] has been improved for depth estimation with a horizontal line array, and the matched sound intensity structure method from Zheng, Yang, Ma, and Du [J. Acoust. Soc. Am. 148, 347–358 (2020)] is introduced as a comparison. The two methods are verified in a deep ocean experiment.
Disentangling local and global climate drivers in the population dynamics of mosquito-borne infections
Authors: Cazelles Bernard , Cazelles Kévin , Tian Huaiyu , Chavez Mario , Pascual Mercedes
Published: September 2023

Identifying climate drivers is essential to understand and predict epidemics of mosquito-borne infections whose population dynamics typically exhibit seasonality and multiannual cycles. Which climate covariates to consider varies across studies, from local factors such as temperature to remote drivers such as the El Niño–Southern Oscillation. With partial wavelet coherence, we present a systematic investigation of nonstationary associations between mosquito-borne disease incidence and a given climate factor while controlling for another. Analysis of almost 200 time series of dengue and malaria around the globe at different geographical scales shows a systematic effect of global climate drivers on interannual variability and of local ones on seasonality. This clear separation of time scales of action enhances detection of climate drivers and indicates those best suited for building early-warning systems.
CHI3L1 signaling impairs hippocampal neurogenesis and cognitive function in autoimmune-mediated neuroinflammation
Authors: Jiang Wei , Zhu Fan , Xu Huiming , Xu Li , Li Haoyang , Yang Xin , Khan Afridi Shabbir , Lai Shuiqing , Qiu Xiusheng , Liu Chunxin , Li Huilu , Long Youming , Wang Yuge , Connolly Kevin , Elias Jack A. , Lee Chun Geun , Cui Yaxiong , Huang Yu-Wen Alvin , Qiu Wei , Tang Changyong
Published: September 2023

Chitinase-3–like protein 1 (CHI3L1) is primarily secreted by activated astrocytes in the brain and is known as a reliable biomarker for inflammatory central nervous system (CNS) conditions such as neurodegeneration and autoimmune disorders like neuromyelitis optica (NMO). NMO is an astrocyte disease caused by autoantibodies targeting the astroglial protein aquaporin 4 (AQP4) and leads to vision loss, motor deficits, and cognitive decline. In this study examining CHI3L1’s biological function in neuroinflammation, we found that CHI3L1 expression correlates with cognitive impairment in our NMO patient cohort. Activated astrocytes secrete CHI3L1 in response to AQP4 autoantibodies, and this inhibits the proliferation and neuronal differentiation of neural stem cells. Mouse models showed decreased hippocampal neurogenesis and impaired learning behaviors, which could be rescued by depleting CHI3L1 in astrocytes. The molecular mechanism involves CHI3L1 engaging the CRTH2 receptor and dampening β-catenin signaling for neurogenesis. Blocking this CHI3L1/CRTH2/β-catenin cascade restores neurogenesis and improves cognitive deficits, suggesting the potential for therapeutic development in neuroinflammatory disorders.
A fitness trade-off between growth and survival governed by Spo0A-mediated proteome allocation constraints in
Bacillus subtilis
Authors: Zhu Manlu , Wang Qian , Mu Haoyan , Han Fei , Wang Yanling , Dai Xiongfeng
Published: September 2023

Growth and survival are key determinants of bacterial fitness. However, how resource allocation of bacteria could reconcile these two traits to maximize fitness remains poorly understood. Here, we find that the resource allocation strategy of
Bacillus subtilis
does not lead to growth maximization on various carbon sources. Survival-related pathways impose strong proteome constraints on
B. subtilis
. Knockout of a master regulator gene,
spo0A
, triggers a global resource reallocation from survival-related pathways to biosynthesis pathways, further strongly stimulating the growth of
B. subtilis
. However, the fitness of
spo0A
-null strain is severely compromised because of various disadvantageous phenotypes (e.g., abolished sporulation and enhanced cell lysis). In particular, it also exhibits a strong defect in peptide utilization, being unable to efficiently recycle nutrients from the lysed cell debris to maintain long-term viability. Our work uncovers a fitness trade-off between growth and survival that governed by Spo0A-mediated proteome allocation constraints in
B. subtilis
, further shedding light on the fundamental design principle of bacteria.
Transcriptomic analysis reveals the rareness of genetic assimilation of gene expression in environmental adaptations
Authors: Chen Piaopiao , Zhang Jianzhi
Published: September 2023

Genetic assimilation is the evolutionary process by which an environmentally induced phenotype becomes genetically encoded and constitutive. Genetic assimilation has been proposed as a concluding step in environmental adaptation, but its prevalence has not been systematically investigated. Analyzing transcriptomic data collected upon reciprocal transplant, we address this question in the experimental evolution, domestication, or natural evolution of seven diverse species. We find that genetic assimilation of environment-induced gene expression is the exception rather than the rule and that substantially more genes retain than lose their expression plasticity upon organismal adaptations to new environments. The probability of genetic assimilation of gene expression decreases with the expression level and number of transcription factors controlling the gene, suggesting that genetic assimilation results primarily from passive losses of gene regulations that are not mutationally robust. Hence, for gene expression, our findings argue against the purported generality or importance of genetic assimilation to environmental adaptation.
RNA structures and dynamics with Å resolution revealed by x-ray free-electron lasers
Authors: Zielinski Kara A. , Sui Shuo , Pabit Suzette A. , Rivera Daniel A. , Wang Tong , Hu Qingyue , Kashipathy Maithri M. , Lisova Stella , Schaffer Chris B. , Mariani Valerio , Hunter Mark S. , Kupitz Christopher , Moss Frank R. , Poitevin Frédéric P. , Grant Thomas D. , Pollack Lois
Published: September 2023

RNA macromolecules, like proteins, fold to assume shapes that are intimately connected to their broadly recognized biological functions; however, because of their high charge and dynamic nature, RNA structures are far more challenging to determine. We introduce an approach that exploits the high brilliance of x-ray free-electron laser sources to reveal the formation and ready identification of angstrom-scale features in structured and unstructured RNAs. Previously unrecognized structural signatures of RNA secondary and tertiary structures are identified through wide-angle solution scattering experiments. With millisecond time resolution, we observe an RNA fold from a dynamically varying single strand through a base-paired intermediate to assume a triple-helix conformation. While the backbone orchestrates the folding, the final structure is locked in by base stacking. This method may help to rapidly characterize and identify structural elements in nucleic acids in both equilibrium and time-resolved experiments.
Boosting systemic absorption of peptides with a bioinspired buccal-stretching patch
Authors: Luo Zhi , Klein Cerrejon David , Römer Simon , Zoratto Nicole , Leroux Jean-Christophe
Published: September 2023

Biopharmaceuticals, including proteins and peptides, have revolutionized the treatment of a wide range of diseases, from diabetes and cardiovascular disorders to virus infections and cancer. Despite their efficacy, most of these macromolecular drugs require parenteral administration because of their high molecular weight and relative instability. Over the past 40 years, only a few oral peptide drugs have entered clinical trials, even when formulated with substantial amounts of permeation enhancers. To overcome the epithelial barrier, devices that inject drugs directly into the gastrointestinal mucosa have been proposed recently. However, the robustness and safety of those complex systems are yet to be assessed. In this study, we introduced an innovative technology to boost drug absorption by synergistically combining noninvasive stretching of the buccal mucosa with permeation enhancers. Inspired by the unique structural features of octopus suckers, a self-applicable suction patch was engineered, enabling strong adhesion to and effective mechanical deformation of the mucosal tissue. In dogs, this suction patch achieved bioavailability up to two orders of magnitude higher than those of the commercial tablet formulation of desmopressin, a peptide drug known for its poor oral absorption. Moreover, systemic exposure comparable to that of the approved oral semaglutide tablet was achieved without further optimization. Last, a first-in-human study involving 40 healthy participants confirmed the dosage form’s acceptability, thereby supporting the clinical translatability of this simple yet effective platform technology.