bluuebunny/crossref_metadata_2025_split huggingface dataset:
Opposing modulation of Cx26 gap junctions and hemichannels by CO2
Authors: Nijjar Sarbjit , Maddison Daniel , Meigh Louise , de Wolf Elizabeth , Rodgers Thomas , Cann Martin J. , Dale Nicholas 
Published: October 2020

Key points
A moderate increase in (55 mmHg) closes Cx26 gap junctions.
This effect of CO2 is independent of changes in intra‐ or extracellular pH.
The CO2‐dependent closing effect depends on the same residues (K125 and R104) that are required for the CO2‐dependent opening of Cx26 hemichannels.
Pathological mutations of Cx26 abolish the CO2‐dependent closing of the gap junction.
Elastic network modelling suggests that the effect of CO2 on Cx26 hemichannels and gap junctions is mediated through changes in the lowest entropy state of the protein.
AbstractCx26 hemichannels open in response to moderate elevations of CO2 ( 55 mmHg) via a carbamylation reaction that depends on residues K125 and R104. Here we investigate the action of CO2 on Cx26 gap junctions. Using a dye transfer assay, we found that an elevated of 55 mmHg greatly delayed the permeation of a fluorescent glucose analogue (NBDG) between HeLa cells coupled by Cx26 gap junctions. However, the mutations K125R or R104A abolished this effect of CO2. Whole cell recordings demonstrated that elevated CO2 reduced the Cx26 gap junction conductance (median reduction 66.7%, 95% CI, 50.5–100.0%) but had no effect on Cx26K125R or Cx31 gap junctions. CO2 can cause intracellular acidification. Using 30 mm propionate, we found that acidification in the absence of a change in caused a median reduction in the gap junction conductance of 41.7% (95% CI, 26.6–53.7%). This effect of propionate was unaffected by the K125R mutation (median reduction 48.1%, 95% CI, 28.0–86.3%). pH‐dependent and CO2‐dependent closure of the gap junction are thus mechanistically independent. Mutations of Cx26 associated with the keratitis ichthyosis deafness syndrome (N14K, A40V and A88V), in combination with the mutation M151L, also abolished the CO2‐dependent gap junction closure. Elastic network modelling suggests that the lowest entropy state when CO2 is bound is the closed configuration for the gap junction but the open state for the hemichannel. The opposing actions of CO2 on Cx26 gap junctions and hemichannels thus depend on the same residues and presumed carbamylation reaction.
Analytical Model for Enhanced Eigen-Mode Sensitivities in a Coupled Micro-Resonator Array for Ultra-Sensitive Mass Measurement
Authors: Chatterjee Animesh 
Published: October 2020

Abstract
Resonant sensors using coupled micro-cantilever array have applications in a wide range of areas including ultrasensitive mass detection of bio-molecules and chemical analytes. A target mass deposited on one of the cantilevers can be detected by measuring shift in eigen-spectrum. Experimental observations indicate that eigenmodes are more sensitive to mass perturbation than resonant frequencies or eigenvalues. However, analytical works, available in literatures, are limited to only two and three cantilever array for eigenvalue sensitivity and only two cantilever array for eigenmode sensitivity. In the present work, an analytical foundation for estimation of eigenmode sensitivities for a general n-array micro-resonator sensor is developed using matrix perturbation theory. The formulation characterizes the modal spectrum and eigenmode sensitivities as a function of elastic interconnection stiffness parameter and unperturbed eigenmodes. Measurement of added mass is demonstrated for different analyte locations using numerically constructed frequency response function (FRF) curves. Error in measurement is also investigated as a function of interconnection stiffness ratio, position of analyte mass, and selection of particular eigenmode to be measured.
A Comparison of the Performance of Constant and Dual Height Pin Fins in Phase Change Material Cooling Technique
Authors: Singh Maibam Romio , Giri Asis 
Published: October 2020

Abstract
This experimental study explores the passive cooling of electronic devices using phase change materials (PCM). Pin fin configurations made of aluminum are considered as thermal conductive enhancers and eicosane as the PCM for the study. The experiment considers four different heat sinks, with 40 and 56 numbers of pin fins. For the same number of pin fin, dual and constant height fin arrangements are study. The volume fractions of TCEs are 9%, 11%, 13%, and 16%. Apart from these heat sinks, a heat sink with no fin (blank heat sink) is considered for baseline comparison. Five different heat fluxes are considered (ranging from 1.17 kW/m2 to 2.35 kW/m2). The effect of number of fins, type of fins, and volumes of PCM has been reviewed. It has been observed that the introduction of fins enhances the heat transfer. An elongation in operational time is achieved in the case of dual height heat sinks compared to constant height heat sink filled with PCM. All the experiments are performed in a temperature-controlled room to avoid environment fluctuation.
Study on the Transient Injection Rate of Each Nozzle Hole in the Combustion Process of Diesel Engine
Authors: Zhou Liying , Liang Yu 
Published: October 2020

Abstract
Based on the measured injection rates obtained from the spray momentum experiment, the three-dimensional computational fluid dynamics simulation study on the effect of injection rate from each nozzle hole on spray characteristics and combustion process was conducted for a one-cylinder diesel engine. The simulation model was successfully verified by the data of the experiment. The results show that at the beginning and mid-stages of injection, the nozzles with a higher transient injection rate exhibit higher jet velocity, bigger spray penetration distance, and wider equivalence ratio distribution. Besides, the disturbance induced by fuel injection on their surrounding gas is higher. Due to the difference in injection rates from each nozzle hole in the cylinder, gas–fuel mixtures are non-uniform. In the case of measured injection rates from each nozzle hole, Hole 4 records the highest instantaneous injection rate. This results in the injection of more fuel during ignition delay. More heat generated from thermal chain reactions raises fuel spray temperatures and quicker ignition of mixtures. In the case of uniform simulated injection rate (injection quantity values are the same as in the previous case), more uniform flow fields and stronger small swirl motions were generated that enhance fuel atomization and mixture formations. At the later stages of injection and combustion, quicker diesel fuel burning rate with a centralized exothermic reaction process occurs due to in-cylinder uniform fuel distribution and air motion. In the case of simulating uniform injection rate from three holes and non-injection from one (same injection quantity values as previous cases), uneven fuel distribution that occurs in the cylinder will result in poor mixture formations and subsequently poor combustion, and more afterburning will occur.
Mode Strategy for Engine Efficiency Enhancement by Using a Magneto-Rheological Variable Valve Train
Authors: Shiao Yaojung , Gadde Premkumar , Kantipudi Mahendra Babu 
Published: October 2020

Abstract
Variable valve timing (VVT) and variable valve lift (VVL) are two promising methods for improving gasoline engine performance. VVL improves part-load performance, and VVT reduces low-speed fuel consumption. Automobile industries and researchers have developed several mechanical, hydraulic, and electronic devices to implement these variable valve functions in engines. In this study, a control strategy is developed for a new compact and low-energy-consumption magneto-rheological valve train (MRVT) to effectively accomplish the variable valve functions and achieve superior engine performance. A non-throttle single-cylinder spark-ignition (SI) engine dynamic model is established to simulate the engine performance by using the flexibility of this new valve train. A six-mode strategy using VVT and VVL is proposed under different engine running conditions of speed and load. Dynamic simulations were conducted for investigating the six-mode strategy based engine performance. The results indicate that the combination of VVT and VVL in the corresponding engine mode can effectively give about 15–20% improvement in the brake fuel efficiency during low and medium speeds. Moreover, by using VVL, about 10–14% improvement in brake specific fuel consumption can be achieved at part-load conditions. According to this computational investigation, the overall engine efficiency and performance can be improved significantly by using a controllable magneto-rheological valve and strategically changing the engine VVL and VVT.
Heat Transfer and Pressure Drop Investigations of the Compact Exhaust Heat Exchanger With Twisted Tape Inserts for Automotive Waste Heat Utilization
Authors: Karana Dhruv Raj , Sahoo Rashmi Rekha 
Published: October 2020

Abstract
Thermoelectric-based waste heat recovery is a competent technique to reduce the exhaust emissions and fuel consumption of automobiles. Thermal and hydraulic characteristics of the exhaust heat exchanger plays a decisive role in the extent of waste heat recovery from the exhaust gas. In this study, the exhaust heat exchanger having twisted tape inserts is proposed to increase the internal heat transfer coefficient. The dimensionless Nusselt number and friction factor were evaluated experimentally for different designs of the twisted tapes. The experiments were performed for the Reynolds number in the range 2300–25000. The considered geometric parameters of the twisted rib explored were the pitch fraction, twist fraction, and slope. The obtained results were compared to reveal the best feasible design of the twisted tape. The maximum net thermohydraulic efficiency factor achieved for the system in the present analysis is 1.93. With the use of twisted tapes, the area of the exhaust heat exchanger can be greatly reduced for the same power output as flat geometry. This would help for the integration of the waste heat recovery with the engine, where the space available is very limited.
Flame Characteristics and Ignition Delay Times of 2,5-Dimethylfuran: A Systematic Review With Comparative Analysis
Authors: Le Van Vang , Hoang Anh Tuan , Nižetić Sandro , Ölçer Aykut I. 
Published: October 2020

Abstract
Global concerns about CO2 levels in the atmosphere, energy security, and the depletion of fossil fuel supply have been the key motivation to develop bio-based fuel resources, which leads to promising and potential strategies of renewable and carbon-neutral biofuels. Among biofuels being strongly developed, 2,5-dimethylfuran (DMF) is a new alternative biofuel candidate since DMF could be synthesized from available and durable lignocellulosic biomass, as well as DMF's physicochemical properties were found to be similar to those of fossil fuels. Therefore, the comprehensive investigation on DMF is very essential before putting DMF into the commercial scale and the engine application. In this current work, the temporal evolutions of laminar flame characteristics including laminar burning velocities, unstretched flame propagation speed, and Schlieren images were critically reviewed based on the comparison of DMF with other fuels. Besides, flame instabilities were also evaluated in detail. Finally, ignition delay times were thoroughly analyzed with the variation of the initial parameters such as temperature, pressure, and equivalent ratio, suggesting that DMF could become the potential fuel for the spark ignition engine. In the future, the experimental studies on the real engines fueled with DMF should be carefully and completely performed to have a comprehensive evaluation of this promising biofuel class.
Spectral Simulation to Investigate the Effects of Active Passive Controls of Nanoparticles on the Radiative Nanofluidic Transport Over a Spinning Disk
Authors: Acharya Nilankush 
Published: October 2020

AbstractThe present investigation deals with the flow dynamics and heat transport of the nanofluid flow over a rotating disk. The flow is considered to be laminar and steady. Active–passive controls of tiny nanoparticles influenced by the Brownian motion and thermophoretic migration are included to reveal the variations in the hydrothermal behaviour. Thermal radiation, velocity slip, and thermal slip are also introduced to model the flow. The foremost governing equations are converted into its dimensionless form after applying the requisite similarity transformation. The spectral quasi-linearization method (SQLM) has been employed to extract the numeric outcomes of the flow. Effects of the underlying parameters on the flow and heat-mass transport are revealed through graphs and tables. Several three-dimensional (3D) and streamlines plots are depicted to enrich the Result and Discussion section. Results assured that the velocities in every direction reduce for velocity slip parameter and magnetic parameter. Temperature increases for thermophoresis and Brownian motion, but reduces for velocity and thermal slip parameter. Active flow reveals high temperature than passive flow. The Brownian motion and thermophoresis provide dual scenario for concentration profile. Heat and mass transport always sustain high magnitude for passive flow.
Large Eddy Simulations for Film Cooling Assessment of Cylindrical and Laidback Fan-Shaped Holes With Reverse Injection
Authors: Singh Ashutosh Kumar , Singh Kuldeep , Singh Dushyant , Sahoo Niranjan 
Published: October 2020

Abstract
The large eddy simulations (LES) are performed to access the film cooling performance of cylindrical and reverse shaped hole for forward and reverse injection configurations. In the case of reverse/backward injection, the secondary flow is injected in such a way that its axial velocity component is in the direction opposite to mainstream flow. The study is carried out for a blowing ratio (M = 1), density ratio (DR = 2.42), and injection angle (α = 35 deg). Formation of counter-rotating vortex pair (CRVP) is one of the major issues in the film cooling. This study revealed that the CRVP found in the case of forward cylindrical hole which promotes coolant jet “liftoff” is completely mitigated in the case of the reverse shaped hole. The coolant coverage for reverse cylindrical and reverse shaped holes is uniform and higher. The reverse shaped hole shows promising results among investigated configurations. The lateral averaged film cooling effectiveness of reverse shaped hole is 1.16–1.42 times higher as compared to the forward shaped holes. The improvement in the lateral averaged film cooling effectiveness of reverse cylindrical hole (RCH) injection over forward cylindrical hole (FCH) injection is 1.33–2 times.
Development of a Hybrid Cooling, Heating, and Power System for Distributed Energy Applications
Authors: Wang Hailei , Kissick Sean , Song Chuankai 
Published: October 2020

Abstract
A unique hybrid cooling, heating, and power (HCHP) concept has been recently developed as an alternative to environmental control units. It combines a small-scale organic Rankine cycle (ORC) with a vapor compression cycle. The unique drive-train design flexibly and efficiently converts engine waste heat into useful energy in the form of cooling, heating, and power depending upon the energy needs. Compared to a standard military environmental control unit which puts an electric load on a diesel generator, the HCHP system uses engine exhaust heat as the primary energy input. Utilizing the exhaust heat can potentially provide 27% reduction on fuel consumption when operating in the cooling mode. When cooling is not needed, it is able to provide power and/or heating output using engine waste heat—a significant advantage over other heat activated cooling technologies. The prototype unit based on the HCHP design has been developed to demonstrate the concept. It leveraged the microchannel heat exchanger and scroll expander technologies to achieve high-performance, small-size, and low-cost design in order to meet the growing distributed energy applications.
A well-appearing infant with a sudden anisocoria
Authors: Servidio Alessia Giuseppina , Peri Francesca , Tenore Andrew , Cesca Laura , Diplotti Laura , Dall'Amico Roberto , Barbi Egidio 
Published: October 2020

Case presentationA 10-month-old boy was admitted to the emergency department due to a sudden onset of left unilateral mydriasis (figure 1). His medical history was unremarkable. A minor head trauma 2 days before was reported, without alarming signs or symptoms. His mother was putting him to sleep, after coming back from work, when she noticed a different pupil size and promptly went to the ED with her husband. The parents denied any use of medications, including nebulised therapy or direct contact with plants. The child was well appearing and his vital signs were within the standard age limits. His extraocular motility was normal as well as the rest of his neurological and physical examination. Parents’ behaviour was somehow remarkable. Even though the child was not suffering, the mother seemed very worried while the father was nervous and aggressive, repeatedly asking for a discharge.Figure 1Left unilateral mydriasis.­QuestionsWhat is the most likely diagnosis based on this clinical presentation?Local contact with a mydriatic substanceIntracerebral haemorrhageBrain tumourThird nerve palsyWhat would be the next step in the investigation to confirm this diagnosis?Brain CTBrain MRIFundus oculi examinationToxicological screening of urineHow is this condition managed, and what is the prognosis?Answers can be found on page XX
Long-term metformin adherence in the Diabetes Prevention Program Outcomes Study
Authors: Walker Elizabeth Arquin , Gonzalez Jeffrey S , Tripputi Mark T , Dagogo-Jack Samuel , Matulik Margaret J , Montez Maria G , Tadros Sameh , Edelstein Sharon L 
Published: October 2020

IntroductionTo investigate long-term metformin adherence in the Diabetes Prevention Program Outcomes Study (DPPOS) by examining: (1) predictors of long-term adherence to study metformin and (2) whether metformin adherence was associated with incident type 2 diabetes.Research design and methodsDPPOS was an open-label continuation of the randomized clinical trial (Diabetes Prevention Program (DPP)) in which eligible participants randomized to the metformin group were offered study metformin and followed over 11 years. A brief structured adherence interview was administered semiannually. Metformin adherence was assessed by pill counts. Predictors of metformin adherence were examined in multivariate regression models. Incident diabetes associated with metformin adherence and other variables was assessed in Cox proportional hazards models.ResultsOf 868 participants eligible to continue taking study metformin, 664 (76%) took at least some metformin over 11 years, with 478 of them reporting problems with adherence. DPPOS cumulative adherence showed significant associations of higher adherence (≥80%) with early adherence at 3 months in DPP (p<0.001) and lower depression scores during DPPOS (p<0.001); significant differences were also seen by race/ethnicity (p<0.004). Predicting adherence by multivariate modeling showed odds of adherence significantly lower for Black participants and for participants reporting more than one barrier. Odds for adherence were significantly higher for those adherent early in DPP and those reporting at least one planned strategy to improve adherence. Higher metformin adherence was significantly associated with a lower diabetes risk (p=0.04), even after adjustment for demographic variables, depression, and anxiety scores.ConclusionsIn this long-term diabetes prevention study, early metformin adherence and planned strategies to promote adherence improved long-term adherence over 11 years; higher adherence to metformin was related to lower diabetes incidence. Incorporating strategies to promote adherence when initially prescribing metformin and counseling to support adherence over time are warranted.
Loss of antiphospholipid antibody positivity post-thrombosis in SLE
Authors: Khawaja Muznay , Magder Laurence , Goldman Daniel , Petri Michelle A 
Published: October 2020

Background/PurposeLoss of positivity of antiphospholipid antibodies has been observed in clinical practice post-thrombosis in patients with SLE with secondary antiphospholipid syndrome (APS). Our study defined the frequency of this loss and the duration before positivity recurred.MethodsIn this prospective study, patients with SLE having at least two positive antiphospholipid markers prior to thrombosis and at least 1 year of follow-up after thrombosis were included. Antiphospholipid markers included lupus anticoagulant (dilute Russell viper venom test >45 s followed by mixing and confirmatory tests) and/or anticardiolipin titre (aCL IgG ≥20, aCL IgM ≥20 and/or aCL IgA ≥20). The percentage of visits with positive antiphospholipid markers after thrombosis was calculated. For patients with a negative antiphospholipid marker any time after thrombosis, survival estimates were performed to calculate the time to return of antiphospholipid positivity.ResultsIn APS due to SLE, complete loss of antiphospholipid positivity post-thrombosis was up to 41% for aCL IgG, 51% for IgM and 50% for IgA, but only 20% for those with lupus anticoagulant. Of those who at some point lost aCL IgG or became negative for lupus anticoagulant, the majority (60% and 76%, respectively) reacquired the antibody within 5 years. In contrast, of those who lost aCL IgM or IgA, fewer reacquired it within 5 years (37% and 17%, respectively).ConclusionIntermittent positivity of antiphospholipid antibodies is present in APS due to SLE. These fluctuations make it difficult to decide on length of anticoagulation. Lupus anticoagulant is more likely to persist post-thrombosis.
Impurity lattice Monte Carlo for hypernuclei
Authors: Frame Dillon , Lähde Timo A. , Lee Dean , Meißner Ulf-G. 
Published: October 2020

AbstractWe consider the problem of including $$\varLambda $$
Λ
hyperons into the ab initio framework of nuclear lattice effective field theory. In order to avoid large sign oscillations in Monte Carlo simulations, we make use of the fact that the number of hyperons is typically small compared to the number of nucleons in the hypernuclei of interest. This allows us to use the impurity lattice Monte Carlo method, where the minority species of fermions in the full nuclear Hamiltonian is integrated out and treated as a worldline in Euclidean projection time. The majority fermions (nucleons) are treated as explicit degrees of freedom, with their mutual interactions described by auxiliary fields. This is the first application of the impurity lattice Monte Carlo method to systems where the majority particles are interacting. Here, we show how the impurity Monte Carlo method can be applied to compute the binding energies of the light hypernuclei. In this exploratory work we use spin-independent nucleon–nucleon and hyperon–nucleon interactions to test the computational power of the method. We find that the computational effort scales approximately linearly in the number of nucleons. The results are very promising for future studies of larger hypernuclear systems using chiral effective field theory and realistic hyperon–nucleon interactions, as well as applications to other quantum many-body systems.