bluuebunny/crossref_metadata_2025 huggingface dataset:
Brokerage that works: Balanced triads and the brokerage roles that matter for innovation
Authors: Llopis Oscar , D'Este Pablo
Published: February 2022

A key premise in innovation literature suggests that individuals enabling contact between pairs of otherwise disconnected others (i.e., holding open triads) are more innovative, as they benefit from more opportunities for knowledge recombination. Such benefits also come with a cost, as conducting innovative action from open triads requires finding common ground to coordinate and integrate disparate knowledge and efforts from unconnected others. However, it is yet unclear which specific open triadic structures offer the greatest net value to facilitate individual innovativeness. We contribute to this debate by going beyond a homogeneous conceptualization of open triads, examining the relation between different brokerage roles and individual innovativeness. We theorize that some roles are more balanced than others in terms of access to knowledge novelty and integration costs. Specifically, we find that balanced open triads (gatekeepers and itinerant roles) are crucial to facilitate individual innovativeness, as compared to unbalanced open triads (coordinator and liaison roles). We also propose that brokers obtain the greatest innovation benefits from balanced open triads when they are embedded in institutional settings that are distant from knowledge applicability. We test our ideas through a large‐scale study of 1,010 biomedical scientists.
Assessment of glomerular filtration rate in patients with cirrhosis: Available tools and perspectives
Authors: Campion Daniela , Rizzi Felice , Bonetto Silvia , Giovo Ilaria , Roma Michele , Saracco Giorgio M. , Alessandria Carlo
Published: February 2022

Renal dysfunction often complicates the course of liver disease, resulting in higher morbidity and mortality. The accurate assessment of kidney function in these patients is essential to early identify, stage and treat renal impairment as well as to better predict the prognosis, prioritize the patients for liver transplantation and decide whether to opt for simultaneous liver–kidney transplants. This review analyses the available tools for direct or indirect assessment of glomerular filtration rate, focusing on the flaws and strengths of each method in the specific setting of cirrhosis. The aim is to deliver a clear‐cut view on this complex issue, trying to point out which strategies to prefer in this context, especially in the peculiar setting of liver transplantation. Moreover, a glance is given at future promising tools for glomerular filtration rate assessment, including new biomarkers and new equations specifically modelled for the cirrhotic population.
Population genetic structure of the malaria vector Anopheles fluviatilis species T (Diptera: Culicidae) in India
Authors: Lather Manila , Mallick Prashant K. , Sharma Divya , Kale Sonal , Dang Amita S. , Adak Tridibes , Singh Om P.
Published: February 2022

Anopheles fluviatilis James (Diptera: Culicidae) represents a complex that comprises four sibling species (S, T, U, and V). Among these, species T is widely distributed in India. Chromosomal inversion polymorphism exists among different geographic populations of An. fluviatilis species T; however, population genetic structure is not understood. This study inferred a genetic structure among six geographically diverse populations of species T using a panel of microsatellite markers. Analyses indicated a significant but low genetic differentiation among the majority of the studied populations. A significant correlation was observed between genetic and geographic distances, exhibiting stepwise migration patterns among populations.
Con‐Ca2+‐tenating plant immune responses via calcium‐permeable cation channels
Authors: Kim Nak Hyun , Jacob Pierre , Dangl Jeffery L.
Published: February 2022

Calcium serves as a second messenger in a variety of developmental and physiological processes and has long been identified as important for plant immune responses. We discuss recent discoveries regarding plant immune‐related calcium‐permeable channels and how the two intertwined branches of the plant immune system are intricately linked to one another through calcium signalling. Cell surface immune receptors carefully tap the immense calcium gradient that exists between apoplast and cytoplasm in a short burst via tightly regulated plasma membrane (PM)‐resident cation channels. Intracellular immune receptors form atypical calcium‐permeable cation channels at the PM and mediate a prolonged calcium influx, overcoming the deleterious influence of pathogen effectors and enhancing plant immune responses.
The physiological basis for estimating photosynthesis from Chla fluorescence
Authors: Han Jimei , Chang Christine Y‐Y. , Gu Lianhong , Zhang Yongjiang , Meeker Eliot W. , Magney Troy S. , Walker Anthony P. , Wen Jiaming , Kira Oz , McNaull Sarah , Sun Ying
Published: February 2022

Solar‐induced Chl fluorescence (SIF) offers the potential to curb large uncertainties in the estimation of photosynthesis across biomes and climates, and at different spatiotemporal scales. However, it remains unclear how SIF should be used to mechanistically estimate photosynthesis.

In this study, we built a quantitative framework for the estimation of photosynthesis, based on a mechanistic light reaction model with the Chla fluorescence of Photosystem II (SIFPSII) as an input (MLR‐SIF). Utilizing 29 C3 and C4 plant species that are representative of major plant biomes across the globe, we confirmed the validity of this framework at the leaf level.

The MLR‐SIF model is capable of accurately reproducing photosynthesis for all C3 and C4 species under diverse light, temperature, and CO2 conditions. We further tested the robustness of the MLR‐SIF model using Monte Carlo simulations, and found that photosynthesis estimates were much less sensitive to parameter uncertainties relative to the conventional Farquhar, von Caemmerer, Berry (FvCB) model because of the additional independent information contained in SIFPSII.

Once inferred from direct observables of SIF, SIFPSII provides ‘parameter savings’ to the MLR‐SIF model, compared to the mechanistically equivalent FvCB model, and thus avoids the uncertainties arising as a result of imperfect model parameterization. Our findings set the stage for future efforts to employ SIF mechanistically to improve photosynthesis estimates across a variety of scales, functional groups, and environmental conditions.
KANADI promotes thallus differentiation and FR‐induced gametangiophore formation in the liverwort Marchantia
Authors: Briginshaw Liam N. , Flores‐Sandoval Eduardo , Dierschke Tom , Alvarez John P. , Bowman John L.
Published: February 2022

In angiosperms, KANADI transcription factors have roles in the sporophyte generation regulating tissue polarity, organogenesis and shade avoidance responses, but are not required during the gametophyte generation. Whether these roles are conserved in the gametophyte‐dominant bryophyte lineages is unknown, which we examined by characterising the sole KANADI ortholog, MpKAN, in the liverwort Marchantia polymorpha.

In contrast to angiosperm orthologs, MpKAN functions in the gametophyte generation in Marchantia, where it regulates apical branching and tissue differentiation, but does not influence tissue polarity in either generation. MpKAN can partially rescue the sporophyte polarity defects of kanadi mutants in Arabidopsis, indicating that MpKAN has conserved biochemical activity to its angiosperm counterparts.

Mpkan loss‐of‐function plants display defects in far‐red (FR) light responses. Mpkan plants have reduced FR‐induced growth tropisms, have a delayed transition to sexual reproduction and fail to correctly form gametangiophores.

Our results indicate that MpKAN is a modulator of FR responses, which may reflect a conserved role for KANADI across land plants. Under FR, MpKAN negatively regulates MpDELLA expression, suggesting that MpKAN and MpDELLA act in a pathway regulating FR responses, placing MpKAN in a gene regulatory network exhibiting similarities with those of angiosperms.
Trait phenology and fire seasonality co‐drive seasonal variation in fire effects on tree crowns
Authors: Bison Nicole N. , Partelli‐Feltrin Raquel , Michaletz Sean T.
Published: February 2022

The plume of hot gases rising above a wildfire can heat and kill the buds in tree crowns. This can reduce leaf area and rates of photosynthesis, growth, and reproduction, and may ultimately lead to mortality. These effects vary seasonally, but the mechanisms governing this seasonality are not well understood.

A trait‐based physical model combining buoyant plume and energy budget theories shows the seasonality of bud necrosis height may originate from temporal variation in climate, fire behaviour, and/or bud functional traits. To assess the relative importance of these drivers, we parameterized the model with time‐series data for air temperature, fireline intensity, and bud traits from Pinus contorta, Picea glauca, and Populus tremuloides.

Air temperature, fireline intensity, and bud traits all varied significantly through time, causing significant seasonal variation in predicted necrosis height. Bud traits and fireline intensity explained almost all the variation in necrosis height, with air temperature explaining relatively minor amounts of variation.

The seasonality of fire effects on tree crowns appears to originate from seasonal variation in functional traits and fire behaviour. Our approach and results provide needed insight into the physical mechanisms linking environmental variation to plant performance via functional traits.
Osteoblast Jmjd3 regulates osteoclastogenesis via EphB4 and RANKL signalling
Authors: Wang Rui , Luo Huikun , Yang Di , Yu Bo , Guo Jiajie , Shao Lina , Okamura Hirohiko , Qiu Lihong
Published: February 2022

Background

Osteoblasts suppress osteoclastogenesis during the reversal phase of bone remodelling and the mechanism needs to be further investigated. Here, we investigated the role of histone demethylase Jumonji domain‐containing 3 (Jmjd3) in osteoblasts on regulating osteoclastogenesis.

Methods

Jmjd3 expression was silenced in osteoblasts. Osteoblasts and osteoclasts were co‐cultured in direct or indirect contact ways, and osteoclastogenesis was determined by tartrate‐resistant acid phosphatase (TRAP) staining and Western blotting. Additionally, Ephrin receptor B4 (EphB4) and receptor activator of nuclear factor‐kappa Β ligand (RANKL) expression were quantified in osteoblasts via real‐time PCR, Western blotting, and enzyme‐linked immunosorbent assay. Subsequently, EphB4 was overexpressed in osteoblasts and RANKL expression and osteoclastogenesis was quantified.

Results

Osteoclastogenesis and marker protein expression levels was promoted when osteoclasts were co‐cultured with Jmjd3‐silenced osteoblasts. Silencing of Jmjd3 expression in osteoblasts decreased EphB4 expression, owing to suppression of demethylation of H3K27me3 on the promoter region of EphB4. Whereas RANKL expression was upregulated in Jmjd3‐silenced osteoblasts. Overexpression of EphB4 in osteoblasts inhibited osteoclastogenesis and RANKL expression.

Conclusion

Jmjd3 in osteoblasts is a crucial regulator of osteoblast‐to‐osteoclast communication through EphB4–EphrinB2, RANKL–RANK and EphB4–RANKL signalling axes, suggesting the pivotal role of Jmjd3 in bone remodelling process in bone destruction disease such as chronic apical periodontitis.
Characteristics of bradyarrhythmia in patients with COVID‐19: Systematic scoping review
Authors: Nagamine Todd , Randhawa Sandeep , Nishimura Yoshito , Huang Ricky , Leesutipornchai Thiratest , Benavente Kevin , Yoshimura Stephanie , Zhang James , Kanitsorphan Chanavuth
Published: February 2022

COVID‐19 has recently been associated with the development of bradyarrhythmias, although its mechanism is still unclear. We aim to summarize the existing evidence regarding bradyarrhythmia in COVID‐19 and provide future directions for research. Following the PRISMA Extension for Scoping Reviews, we searched MEDLINE and EMBASE for all peer‐reviewed articles using keywords including“Bradycardia,” “atrioventricular block,” and “COVID‐19″ from their inception to October 13, 2021. Forty‐three articles, including 11 observational studies and 59 cases from case reports and series, were included in the systematic review. Although some observational studies reported increased mortality in those with bradyarrhythmia and COVID‐19, the lack of comparative groups and small sample sizes hinder the ability to draw definitive conclusions. Among 59 COVID‐19 patients with bradycardia from case reports and series, bradycardia most often occurred in those with severe or critical COVID‐19, and complete heart block occurred in the majority of cases despite preserved LVEF (55.9%). Pacemaker insertion was required in 76.3% of the patients, most of which were permanent implants (45.8%). This systematic review summarizes the current evidence and characteristics of bradyarrhythmia in patients with COVID‐19. Further studies are critical to assess the reversibility of bradyarrhythmia in COVID‐19 patients and to clarify potential therapeutic targets including the need for permanent pacing.
Morphea mimicking facial capillary malformations: Two new cases and review of the literature
Authors: Gomez‐Garcia Luis Alvaro , Rodriguez‐Tamez Giselle , Pérez‐Romero Ana Gabriela , Garnica‐Cruz Patricia , Muñoz‐Garza Fania Zamantta , Ocampo‐Candiani Jorge , Sáez‐de‐Ocariz Marimar , Alba‐Rojas Erika L.
Published: February 2022

Morphea and facial capillary malformations (port‐wine stains) are distinct conditions that can affect the pediatric population. Early localized morphea mimicking a capillary malformation is an uncommon clinical presentation. We present two new cases of girls, aged 2 and 3 years, who presented with erythematous patches, initially diagnosed as capillary malformations, which were later diagnosed as morphea. We also performed a literature review, yielding 12 additional cases that underscore that the unusual presentation of morphea may delay correct diagnosis. Although early management of morphea reduces long‐term sequelae, it is important to delay laser treatment for selected acquired vascular malformations, until the diagnosis of morphea is excluded.
Ingroup Bias, Partisanship, and Gendered Voting
Authors: West Emily Anne
Published: February 2022

This study uses a novel experimental approach to isolate “expressive” or “noninstrumental” payoffs to voting along identity lines, separating them from “substantive” motivations. Applying social identity theory to the case of gender in U.S. elections, the study answers the question: Do some men and women receive a purely expressive payoff from preferring same‐gender candidates? A series of experiments test whether a purely expressive payoff from voting along gender lines is stronger among certain voters. Employing a self‐affirmation treatment and measures of group‐identity attachment, as well as a voting vignette, the evidence shows that Republican men receive a purely expressive payoff from voting for male over female candidates. That is, Republican men’s preference for a male over a female candidate can be reduced by a self‐affirmation treatment that has subjects focus on their individuating characteristics, thereby temporarily “detaching” them from their group attachments. Women and Democratic men are not affected by the self‐affirmation treatment. This study deepens our understanding of voter gender bias in the United States, with a particular focus on the implications of ingroup bias among certain partisan voters for the supply of female candidates within party primary elections.
Pain feedback interferes with reward positivity production
Authors: Heydari Sepideh , Holroyd Clay B.
Published: February 2022

The reinforcement learning (RL) theory of the reward positivity (RewP) proposes that RewP indexes a reward prediction error (RPE) signal processed in the anterior cingulate cortex (ACC). According to this theory, RewP is an event‐related potential (ERP) that is more positive‐going for feedback stimuli that predict better‐than‐expected outcomes (positive feedback) than for feedback stimuli that predict worse‐than‐expected outcomes (negative feedback). Despite strong evidence for this hypothesis, findings have been equivocal for tasks involving painful outcomes. We hypothesized that the RewP is modulated by high‐level task goals such that outcomes that are congruent with the goals elicit positive RPEs even if their immediate consequences are negative. Accordingly, changes in high‐level task goals should modulate RewP amplitude for tasks that involve seeking pain compared to tasks that involve avoiding pain. We recorded the electroencephalogram from participants who were instructed to navigate a virtual T‐Maze to find reward‐predictive feedback in a reward condition and pain‐predictive feedback in a pain condition. We expected more positive‐going ERPs to reward feedback in the reward condition and more positive‐going ERPs to pain feedback in the pain condition. Despite behavioral results indicating that participants complied with task instructions, contrary to our predictions, we did not find a RewP to pain feedback. We suggest that pain feedback interfered with the effect of high‐level task goals on RewP amplitude, which is indicative of conflict at different levels of task hierarchy.
The NF‐κB‐signalling pathway in mare's endometrium infiltrated with the inflammatory cells
Authors: Jasiński Tomasz , Zdrojkowski Łukasz , Kautz Ewa , Juszczuk‐Kubiak Edyta , Ferreira‐Dias Graça , Domino Małgorzata
Published: February 2022

Endometritis is an important issue decreasing mares' fertility. In the case of endometritis, both inflammatory cells infiltration and proinflammatory molecules production are regulated by various cellular and gene regulatory mechanisms, including the nuclear factor‐κB (NF‐κB)‐dependent pathway. NF‐κB‐signalling pathway has been recently studied in the equine endometrium in the context of endometrosis. Thus, this study aimed to determine gene transcription of NF‐κB subunits (RelA; NF‐κB1; NF‐κB2), proinflammatory molecules (MCP‐1; IL‐6) and hyaluronan synthases (HAS 1; HAS 2; HAS 3) in endometritis and compare them with the intensity and type of inflammatory cell infiltration. Endometrial samples, collected post‐mortem from cyclic mares in oestrus or dioestrus, were classified histologically and examined using quantitative PCR. Transcription NF‐κB subunits genes did not differ with either inflammatory intensity or type of inflammatory cell infiltration. Transcription of MCP‐1 and IL‐6 genes increased with the severity of inflammation, with the involvement of HAS 3 and HAS 2 genes, as opposed to HAS 1 genes. These proinflammatory molecules and hyaluronan synthases in the equine inflamed endometrium do not seem to be regulated by the NF‐κB pathway. Hence, separate signalling pathways for the development and progression of equine endometritis and endometrosis may be suggested.
Images of controversy: Examining cognition of hydraulic fracturing among policy elites and the general public
Authors: Moyer Rachael M.
Published: February 2022

Highly contested energy and environmental policy issues are often characterized by entrenched policy debates and inconsistent or failed policies. This study examines the cognition of polarized policy positions in an effort to explain what factors influence the mental models’ individuals use to think about hydraulic fracturing and adopted policy positions on the controversial issue of hydraulic fracturing. The study first examines the role of affect on the use of “cognitive policy images” or the individual‐level mental models used to represent policy positions on hydraulic fracturing using structural topic modeling. Next, regression analysis is used to estimate the effects of theoretically relevant factors on cognition. While previous studies have focused on public attitudes, this study takes a comparative approach to examine policy elite and public cognition around this controversial issue. A comparative approach not only points to subtle differences in how elites and members of the general public cognitively process this controversial policy issue but also provides some insight into how political sophistication factors into cognition and influences policy positions on hydraulic fracturing practices. Conclusions discuss some practical, methodological, and theoretical implications of this work.
Oral manifestations of autoimmune polyglandular syndrome type 1
Authors: Tenório Jefferson R. , Tuma Marina Maués , Andrade Natália Silva , Santana Thalita , Gallottini Marina
Published: February 2022

Aims

Autoimmune polyglandular syndrome type I (APS‐I) is a rare condition of autosomal recessive and monogenic inheritance, which is characterized clinically by at least two signs of the classic triad: mucocutaneous candidosis, hypoparathyroidism, and Addison's disease. This study aims to report the oral manifestations of APS‐I in a 42‐year‐old woman, who attended the Special Care Dentistry Center.

Methods and results

The patient presented with hypoparathyroidism, diabetes mellitus, and autoimmune hepatitis. Chronic hyperplastic candidosis (CHC) was the main oral manifestation and it was diagnosed based on clinical and cytologic characteristics. Microstomia, angular cheilitis, xerostomia, enamel hypoplasia, and microdontia were also present.

Conclusions

CHC was treated with topical nystatin and oral fluconazole, resulting in a significant improvement of the lesions.
Alcohol use and death by suicide: A meta‐analysis of 33 studies
Authors: Isaacs Jason Y. , Smith Martin M. , Sherry Simon B. , Seno Martin , Moore Mackenzie L. , Stewart Sherry H.
Published: February 2022

Introduction

Decades of research show an association between alcohol use and death by suicide. However, findings on the temporal link between alcohol use and death by suicide are unclear. In the most comprehensive meta‐analysis on the topic to date, we analyzed data from longitudinal studies to determine if alcohol use is a risk for death by suicide. We also explored moderators to uncover conditions where the alcohol use‐suicide link is strengthened/weakened.

Methods

Our literature search of six databases yielded 33 eligible studies involving 10,253,101 participants (community, psychiatric, and military samples).

Results

Alcohol use was associated with a 94% increase in the risk of death by suicide. Specifically, random‐effects meta‐analysis revealed alcohol use displayed small‐to‐large significant risk and odds ratios with suicide for quantity of alcohol use and alcohol use diagnosis/alcohol‐related problems. Meta‐regression generally indicated larger effect sizes for studies with a higher percentage of women, younger age, unadjusted estimates, longer follow‐up periods, military samples, and higher frequencies and quantities of alcohol use (relative to drinker/non‐drinker status).

Conclusion

Our study highlights alcohol use as a substantive risk factor for death by suicide and underscores the importance of monitoring alcohol use among suicidal individuals and screening for suicidality among heavier alcohol users.
COVID-19 Overview, Natural Immune-Boosting Medication, and The Economic Implication
Authors: Oves Mohammad
Published: February 2022

An outbreak of severe acute respiratory syndrome (SARS) novel coronavirus-2 (SARS-nCoV-2) caused unprecedented ongoing health and socioeconomic crises. So far, millions have got infected, living with life-threatening challenges. The corporate world is striving to survive. The scientific community explores various strategies to invent vaccines and/or therapeutic options to control this viral pandemic. This SARS-nCoV-2 is highly contagious and can be exponentially transmitted from human to human. Most of the patients have similar pneumonia symptoms, and at a later stage, it causes lung damage, breathing difficulties, and reduced gas exchange. More specifically, this infection exacerbates the problem in the case of secondary illness or disease. There is a striving need for a novel strategy to control the virus spread and treat related pathogens with all these challenges. Researchers have suggested some natural compounds (curcumin, quercetin, cinnamaldehyde, and lactoferrin), nutraceuticals, probiotics, and vitamin therapy for immune-boosting because they have high anti-inflammatory effects. Here, in this review, we compiled the updated information on the current status, clinical symptoms, pathogenesis, possible new green targets (herbal medicine), and challenges associated with developing potential vaccines.
Research on Reliability of Ni/Sn/Cu(Ni) Copper Pillar Bump Under Thermoelectric Loading
Authors: Dai Junjie , Zhang Yuexin , Li Zhankun , Chen Mingming , Guo Yuhua , Fan Zhekun , Li Junhui
Published: February 2022

With the development of packaging devices toward high performance and high density, electronic devices are subjected to thermo-electric stresses under service conditions, which has become a particularly important reliability problem in micro-electronics packaging. The reliability of the chip under thermo-electric stresses is studied in this paper. First, thermo-electric coupling experiments were carried out on two solder joint structures of Ni/Sn3.5Ag/Cu and Ni/Sn3.5Ag/Ni. The interface evolution of solder joints under different current densities was analyzed. The reliability of the two structures under thermo-electric stresses was compared and analyzed. After that, three-dimensional finite element analysis was employed to simulate the current density, Joule heat, and temperature distribution of the flip chip. Finally, through the combination of experiment and simulation, the distribution of Joule heat and temperature of the chip was analyzed. The results show that the Ni/Sn3.5Ag/Ni structure has better reliability than the Ni/Sn3.5Ag/Cu structure under thermal–electric coupling. In addition, when the Ni layer was used as the cathode side, the constant temperature applied on the chip was 150 °C, and the current density was higher than 5 × 104 A/cm2, the dissolution failure of the Ni layer occurred in two structures. Because the higher current density generated a large amount of Joule heat where the current was crowded, resulting in excessively high temperature and rapid dissolution of the Ni barrier layer.
Experimental and Numerical Analysis of Data Center Pressure and Flow Fields Induced by Backward and Forward CRAH Technology
Authors: Tradat Mohammad I. , Manaserh Yaman “Mohammad Ali” , Gharaibeh Ahmad , Sammakia Bahgat G. , Hall Dave , Nemati Kourosh , Seymour Mark
Published: February 2022

An increasingly common power saving practice in data center thermal management is to swap out air cooling unit blower fans with electronically commutated plug fans, Although, both are centrifugal blowers. The blade design changes: forward versus backward curved with peak static efficiencies of 60% and 75%, respectively, which results in operation power savings. The side effects of which are not fully understood. Therefore, it has become necessary to develop an overall understanding of backward curved blowers and compare the resulting flow, pressure, and temperature fields with forwarding curved ones in which the induced fields are characterized, compared, and visualized in a reference data center which may aid data center planning and operation when making the decisions of which computer room air handler (CRAH) technology to be used. In this study, experimental and numerical characterization of backward curved blowers is introduced. Then, a physics-based computational fluid dynamics model is built using the 6sigmaroom tool to predict/simulate the measured fields. Five different scenarios were applied at the room level for the experimental characterization of the cooling units and another two scenarios were applied for comparison and illustration of the interaction between different CRAH technologies. Four scenarios were used to characterize a CRAH with backward curved blowers, during which a CRAH with forwarding curved was powered off. An alternate arrangement was examined to quantify the effect of possible flow constraints on the backward curved blower's performance. Then parametric and sensitivity of the baseline modeling are investigated and considered. Different operating conditions are applied at the room level for experimental characterization, comparison, and illustration of the interaction between different CRAH technologies. The measured data is plotted and compared with the computational fluid dynamics (CFD) model assessment to visualize the fields of interest. The results show that the fields are highly dependent on CRAH technology. The tile to CRAH airflow ratios for the flow constraints of scenarios 1, 2, 3, and 4 are 85.5%, 83.9%, 61%, and 59%, respectively. The corresponding leakage ratios are 14.5%, 16%, 38.9%, and 41%, respectively. Furthermore, the validated CFD model was used to investigate and compare the airflow pattern and plenum pressure distribution. Lastly, it is notable that a potential side effect of backward curved technology is the creation of an airflow dead zone.
A New Structure of Ceramic Substrate to Reduce the Critical Electric Field in High Voltage Power Modules
Authors: Yan Feifei , Wang Laili , Gan Yongmei , Li Kaixuan , Zhang Boya
Published: February 2022

The blocking voltage level of silicon carbide (SiC) can reach 10–25 kV, which will significantly increase the power density and capacity of power modules. However, high voltage can induce a high electric field, increase the risk of partial discharge (PD), and threaten the insulation reliability. This paper focuses on the triple points between the metal electrode, silicone gel, and ceramic in power modules. The influencing factors of the electric field at different triple points are fully analyzed. PD experiments are performed and the results show that the interface between silicone gel and ceramic is a weak area of insulation. Therefore, this paper demonstrates that area of weak insulation and high electric field meet at the triple point. To solve this problem, a new structure of the ceramic substrate is proposed, which isolates the interface area from the high electric field. At the same time, the new structure can significantly reduce the high electric field reinforcement.
A Direct Numerical Simulation Investigation of the One-Phase Flow in a Simplified Emulsification Device
Authors: Olad Peyman , Crialesi Esposito Marco , Brandt Luca , Innings Fredrik , Håkansson Andreas
Published: February 2022

More detailed investigation of the flow inside emulsification devices, e.g., High-pressure homogenizers (HPHs) helps the industry to broaden the fundamental understanding of the working principle of these machines which in turn will pave the road to increase the breakup efficiency of emulsification processes. Direct numerical simulation (DNS) is not deemed as a practical method in industry due to the high computational cost and time. This study is the first DNS carried out on a model of an emulsification device model. The goal of this study is to set a benchmark for future CFD investigations using industrially favorable tools (RANS, LES, etc.). A scale-up model HPH is designed and the results show a successful modeling of the flow field mimicking the flow behavior inside a typical HPH.
Validation of the Porous Medium Approximation for Hydrodynamics Analysis in Compact Heat Exchangers
Authors: Zhu Qingzi , Pishahang Mehdi , Caccia Mario , Kelsall Colin C. , LaPotin Alina , Sandhage Kenneth H. , Henry Asegun
Published: February 2022

Compact heat exchangers (HXs) have gained attention in recent years in various fields such as solar and nuclear power generation, oil and gas, and refrigeration due to their low cost, high power density, and robustness in high-pressure and/or high-temperature environments. However, the large difference between a compact HX's overall dimensions (∼m) and the much smaller scale of its channels (∼mm) makes it challenging to model the entire HX at once, due to computational limitations. In this work, we treat the channeled region of a compact HX as a porous medium (PM) to circumvent the need to model/mesh each individual channel. This allows us to simulate the entire HX, including both the header and channeled regions while maintaining the computational cost at a practical level. Although the porous medium approach has been used to model heat exchangers, its validity is still questionable because (1) the resistance coefficients are heavily data-based and thus difficult to be applied to new heat exchangers and (2) the validation has been focused on matching the overall pressure drop in the channel region, which does not address whether such model can predict detailed pressure and velocity field. For the first time, this work addresses under what circumstances and with what uncertainty does the PM approach work for hydrodynamics modeling in compact HXs. By answering these questions, we introduce the PM approach as a powerful tool for HX hydrodynamics modeling that can predict not only the overall pressure drop but also the detailed pressure and velocity distributions.
Investigation of the Flow Instabilities of a Low Specific Speed Pump Turbine Part 1: Experimental and Numerical Analysis
Authors: Deniz Sabri , Del Rio Armando , von Burg Martin , Tiefenthaler Manuel
Published: February 2022

This is the first part of a two-part paper focusing on the flow instabilities of pump turbines. In this first part, results of the experiments and computational fluid dynamics (CFD) simulations of the research carried out on a low specific speed model pump turbine at HSLU (Lucerne University of Applied Sciences) Switzerland are presented. The requirements of a stable and reliable pump turbine operation, under continuously expanding operating ranges, challenge the hydraulic design and demand new developments. This paper presents the results of experimental (model pump turbine at the test rig) and numerical (CFD) investigations of the pump turbine instabilities of a low specific speed (nq = 25) pump turbine in the turbine operating mode. Four-quadrant characteristics of a low specific speed pump turbine with two similar runners differentiating in the size (diameter) are measured. Testing of both runners with the same guide vane system provided information about the effects of the increased vaneless space on the pump turbine performance and stability. A CFD methodology is developed by applying several turbulence models to accurately predict the characteristics of the reversible pump turbines in the S-shaped region (speed no load conditions) as well as to analyze the flow features especially at off-design conditions. This CFD model is validated against the experimental data at 6 deg and 18 deg guide vane openings in turbine operating mode. Using the data of the unsteady pressure measurements and detailed investigation of unstable ranges on the pump turbine characteristics, flow instabilities in the low-specific speed model pump turbine are analyzed. Relevant frequencies such as rotating stall, steady and unsteady vortex formations are determined.
Investigation of the Flow Instabilities of a Low Specific Speed Pump Turbine Part 2: Flow Control With Fluid Injection
Authors: Deniz Sabri , von Burg Martin , Tiefenthaler Manuel
Published: February 2022

This is the second part of a two-part paper focusing on the flow instabilities of low-specific speed pump turbines. In this part, results of the flow control application with fluid injection in the vaneless space for suppressing the flow instabilities of a model pump turbine in turbine mode operation at HSLU (Lucerne University of Applied Sciences) Switzerland are presented. Using the experimental data and CFD results, the onset and development of flow instabilities are explored in the first part of this paper. Based on these analyses, a flow control technology using injection of fluid in the vaneless space of the model pump turbine is implemented in order to suppress the flow instabilities and, thereby, to extend the operating range. Through use of an external energy source, air and water injection are applied with discrete nozzles that are circumferentially distributed in the vaneless space. The S-shaped pump turbine characteristics in turbine operating mode are modified so that the slope at speed no load conditions is no more positive meaning an improvement in the stability behavior. To the best of our knowledge, this is the first successful application of flow control with fluid injection in the vaneless space of pump turbines. Fluid injection is applied at two different guide vane openings. The analysis of the unsteady pressure data indicates that fluid injection in the vaneless space suppresses the flow instability such as rotating stall. Moreover, the water injection turns out to be more effective than the air injection for modifying the slope of the pump turbine characteristics.
Multiphase Flows in Plate and Shell Heat Exchangers
Authors: Costa M. O. B. , Beckedorff L. , de Paiva K. V. , Oliveira J. L. G.
Published: February 2022

Air–water and air–water–oil flows were analyzed in a complex channel prototype of a plate and shell heat exchanger (PSHE) with the aid of a fast camera. Air–water flows were characterized before the PSHE inlet port by electrical capacitance tomography (ECT). The effects of inlet pipe flow pattern (bubbly, stratified, or slug) and flow direction (upward or downward) on PSHE air–water flows were investigated. The resultant phase distribution within the PSHE channel was determined by imaging analysis. Instantaneous velocity fields projected on the channel frontal plane were obtained with particle image velocimetry (PIV) for the dispersed phase of bubbly flows. Stratified pipe flow pattern results in PSHE channel segregated flow. The thermal analysis of segregated flow patterns occurring in the hot and cold sides of a PSHE reveals that the countercurrent configuration may present worse heat transfer performance than the parallel one. PSHE multiphase flows are characterized by breakup phenomenon: the mixture among phases is intensified even if stratification occurs at the inlet port. Oil–water–air downward flows are characterized by oil–water emulsion at the channel center and by water and air–water streams at the channel external part. Oil–water–air upward flows are characterized by air–water and oil–water emulsions at the channel center and by the water stream at the channel external part.
Combined Effects of the Turbulence and Interfacial Momentum Transfer on Two-Phase Turbulent Bubbly Flows
Authors: Aouadi Aroua , Bellakhal Ghazi , Chahed Jamel
Published: February 2022

The paper studies one-way and two-way coupling interactions between the liquid turbulence and bubbles' presence in bubbly jets. One-way coupling focuses on jet with low void fraction in which the bubbles have no significant effect on the hydrodynamic liquid fields in comparison to the single-phase jet. It sets out to model the interfacial momentum transfer identifying the turbulent contribution and its effect on the bubbles' dynamics and phase distribution. Two-way coupling considers jets with high void fractions where the liquid turbulence is altered by the bubbles which in turn influence the interfacial momentum transfers. This paper aims to improve the two-fluid model closures by implementing in computational fluid dynamics code a three-equation turbulence model and new interfacial momentum transfer closures. A benchmark of turbulence models combined with different interfacial exchange modeling is achieved to highlight the strong couplings between the interfacial forces, the phase distribution and the hydrodynamic fields of both phases.
Risk factors for epiretinal membrane in eyes with primary rhegmatogenous retinal detachment that received silicone oil tamponade
Authors: Pan Qintuo , Gao Zhiqiang , Hu Xuting , Wu Qi , Zheng Jing Wei , Zhang Zong-Duan
Published: February 2022

Background/aims

This study investigated the risk factors for epiretinal membrane (ERM) in eyes with primary rhegmatogenous retinal detachment (RRD) that received silicone oil (SO) tamponade.

Methods

This retrospective analysis included 1140 patients (1140 eyes) with RRD who underwent primary vitrectomy and SO tamponade. The prevalence of ERM was estimated and possible risk factors (eg, type 2 diabetes, proliferative vitreoretinopathy (PVR), SO tamponade time (SOTT), photocoagulation, vitreous haemorrhage, choroidal detachment, cryotherapy and retinal tear size) were analysed via multiple logistic regression.

Results

The prevalence of ERM was 12.3% (140/1140), and the accuracy of preoperative ERM diagnosis was 40.5%. Multivariate logistic regression analysis showed that risk factors for ERM in eyes with SO tamponade included preoperative PVR (OR=4.336, 95% CI 2.533 to 7.424, p<0.001), type 2 diabetes (OR=3.996, 95% CI 2.013 to 7.932, p<0.001), photocoagulation energy (OR=1.785, 95% CI 1.306 to 2.439, p<0.001) and SOTT (OR=1.523, 95% CI 1.261 to 1.840, p<0.001). No statistically significant associations were observed between the incidence of ERM and other risk factors. Preoperative PVR showed the strongest association with risk of ERM. The risk of ERM was positively associated with SOTT, photocoagulation energy and preoperative PVR grade.

Conclusion

In eyes with RRD that received SO tamponade, the prevalence of ERM was 12.3%, while the accuracy of preoperative ERM diagnosis was low. Preoperative PVR, type 2 diabetes, photocoagulation energy and SOTT were the main risk factors for ERM.
Better outcomes from exercise-related out-of-hospital cardiac arrest in males and in the young: findings from the Swedish Registry of Cardiopulmonary Resuscitation
Authors: Frisk Torell Matilda , Strömsöe Anneli , Herlitz Johan , Claesson Andreas , Rawshani Araz , Borjesson Mats
Published: February 2022

Background

Survival from out-of-hospital cardiac arrest (OHCA) is higher if the arrest is witnessed and occurs during exercise, however, there is contradicting data on prognosis with regards to sex and age. The purpose of this study was to compare the outcomes and circumstances of exercise-related OHCA in different age groups and between sexes in a large unselected population.

Methods

Data from exercise-related OHCAs reported to the Swedish Registry of Cardiopulmonary Resuscitation from 2011 to 2014 and from 2016 to 2018 were analysed. All cases of exercise-related OHCA in which emergency medical services attempted resuscitation were included. The primary outcome was survival to 30 days.

Results

In total, 635 cases of exercise-related OHCA outside of the home were identified. The overall 30-day survival rate was 44.5% with highest survival rate in the age group 0–35 years, compared with 36–65 years and >65 years (59.6% vs 46.0% and 40.4%, p=0.01). A subgroup analysis of 0–25 years showed a survival rate of 68.8%. Exercise-related OHCA in females (9.1% of total) were witnessed to a lower extent (66.7% vs 79.6%, p=0.03) and median time to cardiopulmonary resuscitation (CPR) was longer (2.0 vs 1.0 min, p=0.001) than in males. Females also had lower rates of ventricular fibrillation (43.4% vs 64.7%, p=0.003) and a lower 30-day survival rate (29.3% vs 46.0%, p=0.02).

Conclusion

In exercise-related OHCA, younger victims have a higher survival rate. Exercise-related OHCA in females was rare, however, survival rates were lower compared with males and partly explained by a lower proportion of witnessed events, longer time to CPR and lower frequency of a shockable rhythm.
Patient-derived cellular models of primary ciliopathies
Authors: Pollara Lidia , Sottile Virginie , Valente Enza Maria
Published: February 2022

Primary ciliopathies are rare inherited disorders caused by structural or functional defects in the primary cilium, a subcellular organelle present on the surface of most cells. Primary ciliopathies show considerable clinical and genetic heterogeneity, with disruption of over 100 genes causing the variable involvement of several organs, including the central nervous system, kidneys, retina, skeleton and liver. Pathogenic variants in one and the same gene may associate with a wide range of ciliopathy phenotypes, supporting the hypothesis that the individual genetic background, with potential additional variants in other ciliary genes, may contribute to a mutational load eventually determining the phenotypic manifestations of each patient. Functional studies in animal models have uncovered some of the pathophysiological mechanisms linking ciliary gene mutations to the observed phenotypes; yet, the lack of reliable human cell models has previously limited preclinical research and the development of new therapeutic strategies for primary ciliopathies. Recent technical advances in the generation of patient-derived two-dimensional (2D) and three-dimensional (3D) cellular models give a new spur to this research, allowing the study of pathomechanisms while maintaining the complexity of the genetic background of each patient, and enabling the development of innovative treatments to target specific pathways. This review provides an overview of available models for primary ciliopathies, from existing in vivo models to more recent patient-derived 2D and 3D in vitro models. We highlight the advantages of each model in understanding the functional basis of primary ciliopathies and facilitating novel regenerative medicine, gene therapy and drug testing strategies for these disorders.
Social networks, high-risk anal HPV and coinfection with HIV in young sexual minority men
Authors: Fujimoto Kayo , Nyitray Alan G , Kuo Jacky , Zhao Jing , Hwang Lu-Yu , Chiao Elizabeth , Giuliano Anna R , Schneider John A , Khanna Aditya
Published: February 2022

Objectives

Young sexual minority men (SMM) exhibit a high prevalence and incidence of high-risk genotypes of human papillomavirus (hrHPV) anal infections and a confluence of a high prevalence of HIV and rectal STIs. Social determinants of health (SDOHs) are linked to social network contexts that generate and maintain racial disparities in HIV and STIs. A network perspective was provided to advance our knowledge of drivers of genotype-specific hrHPV infection and coinfection with HIV. The study also examined whether socially connected men are infected with the same high-risk HPV genotypes and, if so, whether this tendency is conditioned on coinfection with HIV.

Methods

Our sample included 136 young SMM of predominantly black race and their network members of other races and ethnicities, aged 18–29 years, who resided in Houston, Texas, USA. These participants were recruited during 2014–2016 at the baseline recruitment period by network-based peer referral, where anal exfoliated cells and named social and sexual partners were collected. Exponential random graph models were estimated to assess similarity in genotype-specific hrHPV anal infection in social connections and coinfection with HIV in consideration of the effects of similarity in sociodemographic, sexual behavioural characteristics, SDOHs and syphilis infection.

Results

Pairs of men socially connected to each other tend to be infected with the same hrHPV genotypes of HPV-16, HPV-45 and HPV-51 or HPV-16 and/or HPV-18. The tendency of social connections between pairs of men who were infected with either HPV-16 or HPV-18 were conditioned on HIV infection.

Conclusions

Networked patterns of hrHPV infection could be amenable to network-based HPV prevention interventions that engage young SMM of predominantly racial minority groups who are out of HIV care and vulnerable to high-risk HPV acquisition.