bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Fabrication of Graded Copper Inverse Opals (g-CIOs) for Capillary-Fed Boiling in High Heat Flux Cooling Applications
Authors: Wu Qianying , Zhang Chi , Asheghi Mehdi , Goodson Kenneth 
Published: December 2020

Abstract
Capillary-fed boiling in microporous copper inverse opals (CIOs) is capable of removing an excess of 1 kW/cm2 at 10–15 °C superheat over small wicking distances ∼ 200 μm. In order to remove heat from large area chips (&gt; 1 cm2), longer capillary wicking distance is desired to reduce the manufacturing complexity of the 3D manifold for liquid delivery and vapor extraction. In this study, we propose graded copper inverse opals (g-CIOs) where smaller pores at the bottom provide high capillary pressure for liquid delivery, while larger pores at the top reduce viscous pressure drop for vapor extraction. This nonhomogeneous wicking material decouples the permeability and capillary pressure in the vertical and lateral directions, resulting in greater CHFs and capillary wicking distances. In this study, we demonstrate the feasibility of fabricating g-CIOs material with up to three different pore diameters (2 μm, 5 μm, and 10 μm) using a multi-step template sintering and copper electrodeposition process. We then leverage and expand upon a well-calibrated experimental model for the prediction of CHF in monoporous CIOs to map the performance metrics for g-CIOs. The model combines a hydraulic resistance network with Darcy’s law and accounts for the nonhomogeneous permeabilities in lateral and vertical directions. Using this model, we study the impact of total wick thickness and graded pore-size combinations on the critical heat fluxes and wicking distances. Our modeling results conclude that a two-layer g-CIOs can potentially reach ∼70% enhancement in the critical heat flux or ∼30% enhancement in the wicking length compared to monoporous CIOs of the same thickness. Our fabrication capability and preliminary modeling results offer the opportunity to design boiling tests with optimized g-CIOs and exploring the potential of dissipating high heat flux for large area cooling applications.
Silicon Carbide Power Module Co-Designed for Enhanced Thermal and Electrical Performance in Steady State and Transient Conditions
Authors: Gowda Arun V. , Miorini Rinaldo L. , Fish Michael , Sharar Darin J. , deBock Peter 
Published: December 2020

Abstract
The demand for high power density, therefore high heat dissipation, silicon carbide power electronics modules is propelled by applications such as hybrid transportation and renewable power generation and conversion, among others. Besides a low thermal resistance, these applications require high thermal capacitance to manage transient operations.
The Package Integrated Cyclone COoler (PICCO) is an additively manufactured, thermal energy storing cooler codesigned by GE Research (GRC) in collaboration with the US Army Research Lab (ARL). The key aspect of PICCO is its capability to swirl a two-phase coolant, i.e. liquid-gas. The centrifugal field creates a radial pressure gradient inducing buoyancy. The strong radial acceleration to which the fluid is subject forces relatively cold flow outward to reach the hot wall, thus boosting the heat transfer, while hot flow and bubbles migrate inward and the two-phase system is nearly isothermal (thermal storage).
In this paper, we introduce a novel power module package which brings together silicon carbide devices, Power OverLay (POL) wirebondless interconnect, and two-phase swirling flow in an additively manufactured cooler. Various embodiments of this power module structure are presented along with a discussion on their thermal behavior when subjected to a hybrid vehicle drive cycle.
Evolution of Anand Parameters With Elevated Temperature Aging for SAC Leadfree Alloys
Authors: Lall Pradeep , Yadav Vikas , Suhling Jeff , Locker David 
Published: December 2020

Abstract
Electronic equipment in automotive, agricultural and avionics applications may be subjected to temperatures in the range of −55 to 200°C during storage, operation and handling in addition to high strain-rates. Strain rates in owing to vibration and shock may range from 1–100 per sec. Temperature in electronic assemblies depends typically on location, energy dissipation and thermal architecture. Some investigators have indicated that the required operating temperature is between −40 to 200°C for automotive electronics located underhood, on engine, on transmission. Prior data indicates the evolution of mechanical properties under extended exposures to high temperatures. However, the constitutive models are often only available for pristine materials only. In this paper, effect of low operating temperatures (−65°C to 0°C) on Anand-model parameters at high strain rates (10–75 per sec) for aged SAC (SAC105 and SAC-Q) solder alloys has been studied. Stress-Strain curves have been obtained at low operating temperatures using tensile tests. The SAC leadfree solder samples were subjected to isothermal-aged up to 4-months at 50°C before testing. Anand Viscoplastic model has been used to describe the material constitutive behavior. Evolution of Anand Model parameters for SAC solder has been investigated. The computed parameters of the experimental data were used to simulate the tensile test and verified the accuracy of the model. A good correlation was found between experimental data and Anand predicted data.
Degradation Mechanisms of Underfills Subjected to Isothermal Long-Term Aging From 150°C to 200°C
Authors: Lall Pradeep , Zhang Yunli , Wu Haotian , Davis Ed , Suhling Jeff 
Published: December 2020

Abstract
FCBGAs are finding applications in automotive underhood environments where they may be subjected to sustained temperatures of 125–200°C for sustained periods during operation. While, FCGBAs have been previously used in consumer applications where operating temperatures typically range in 55–85°C, relatively little is known on methods to design damage-tolerant packages in automotive underhood environments. There is insufficient information on plastic encapsulated electronic components capable of surviving high temperatures for long periods (&gt; 100,000 hours). In this paper, four different types of underfills has been cured and aged. Mechanical tests have been performed on all the four types of underfills too understand the degradation in properties under extended high temperature operation. Uniaxial tensile tests are conducted to study the elastic modulus, ultimate tensile strength and percentage elongation of the underfills. After uniaxial tensile tests, Optical Microscope, SEM and EDS are applied to study the microstructure behaviors of the cross-section area of the underfills. The experimental results are compared before and after aging tests, including pristine, 30 days, 60 days, 90days, 120 days and 240 days. The research focuses on microstructure-property-processing-performance relationships, building the relation between the microstructure evolution and macro-mechanical properties. Reliability physics of high temperature degradation of packaging material is studied.
Study of Lead Free Solder Joints Subjected to Isothermal Mechanical Shear Cycling
Authors: Hoque Mohd Aminul , Haq Mohammad Ashraful , Suhling Jeffrey C. , Lall Pradeep 
Published: December 2020

Abstract
Electronic packages are usually subjected to varying temperature conditions, thus subjecting the package to thermal cyclic loadings. As the different components of the package are made up of materials of different Coefficients of Thermal Expansion (CTE), the thermal cyclic loading brings about fluctuating shear stress to arise within the package, ultimately leading to its failure. It has been seen in previous literature that the recrystallization assisted cracking is a major factor that leads to the failure of solder joints when subjected to thermomechanical cycles. In this study, the authors have tried to determine whether the mechanical shear cycling of aged and non-aged samples of SAC305 lead free solder joints undergo a recrystallization phase before its ultimate failure. Arrays (3 × 3) of SAC305 solder joints of roughly 750μm in diameter were reflowed in between two FR-4 printed circuit boards to create a sandwiched structural sample. The samples were then polished to expose the solder joints. A polarized light microscope was utilized to capture the images of the joints before and after the mechanical cycling and analyzed to observe any changes in the microstructure in the form of recrystallization of the tin grains.
Molecular Dynamics Investigation of Water Behavior Through Nanopores
Authors: Montazeri Kimia , Cao Penghui , Won Yoonjin 
Published: December 2020

Abstract
The transport of fluids through nanoscale pores, channels, and membranes has been of great importance in our daily life. Nanoscale transport is relevant to many applications such as agriculture, energy and environmental fields. Considering these applications, it is important to characterize detailed mechanisms of liquid transport through nanoscale defects and pores on surfaces. Such characterization requires a detailed understanding of the deviation of water behavior and its transport mechanisms in nanoscale from bulk water. Molecular dynamics provide proper means to understand the dynamics and mechanisms of motions of water molecules confined in ultra-small spaces. This work examines the water transport through an individual pore which has a nanoscale dimensions ranging from 1.0 to 1.8 nm from molecular dynamics perspective. The effects of the nanopore dimensions as well as the surface wetting properties on the behavior of confined water are studied. The translational and rotational dynamics of water molecules are characterized by examining velocity autocorrelation functions and the calculation of the density of states, which supports the presence of unusual, solid-like behaviors of water molecules. A good understanding of the transport mechanisms and their origins are crucial to address common challenges in many engineering applications such as energy storage and conversion and could pave the way towards more efficient water-energy systems.
Structure of oceanic crust in back-arc basins modulated by mantle source heterogeneity
Authors: Grevemeyer Ingo , Kodaira Shuichi , Fujie Gou , Takahashi Narumi 
Published: December 2020

Abstract
Subduction zones may develop submarine spreading centers that occur on the overriding plate behind the volcanic arc. In these back-arc settings, the subducting slab controls the pattern of mantle advection and may entrain hydrous melts from the volcanic arc or slab into the melting region of the spreading ridge. We recorded seismic data across the Western Mariana Ridge (WMR, northwestern Pacific Ocean), a remnant island arc with back-arc basins on either side. Its margins and both basins show distinctly different crustal structure. Crust to the west of the WMR, in the Parece Vela Basin, is 4–5 km thick, and the lower crust indicates seismic P-wave velocities of 6.5–6.8 km/s. To the east of the WMR, in the Mariana Trough Basin, the crust is ∼7 km thick, and the lower crust supports seismic velocities of 7.2–7.4 km/s. This structural diversity is corroborated by seismic data from other back-arc basins, arguing that a chemically diverse and heterogeneous mantle, which may differ from a normal mid-ocean-ridge–type mantle source, controls the amount of melting in back-arc basins. Mantle heterogeneity might not be solely controlled by entrainment of hydrous melt, but also by cold or depleted mantle invading the back-arc while a subduction zone reconfigures. Crust formed in back-arc basins may therefore differ in thickness and velocity structure from normal oceanic crust.
Efficacy of antiviral therapy in patients with post-hepatitis C liver cirrhosis: is hyperuricaemia a potential adverse effect?
Authors: Elsayed Amr , M Abdelraheem Ehab , Hassan Hatem , Abbas Abbas , Hassnine Alshymaa 
Published: December 2020

Hepatitis C virus (HCV) related liver cirrhosis is considered a major health problem; sofosbuvir (SOF)/ledipasvir (LDV) and SOF/daclatsvir (DACLA) are very promising direct antiviral agents (DAAS) especially in treating HCV genotype 4 which is the main genotype in Egypt. Uric acid elevation was reported in many systemic diseases and might be elevated during direct antiviral therapy. The aim is to evaluate efficacy and safety of SOF/LDV and SOF/DACLA plus ribavirin in treating HCV related child A liver cirrhosis and assess hyperuricaemia as a potential adverse effect to this regimen.MethodsThis prospective observatinal study included 128 HCV naive child A cirrhotic patients divided into two groups (77 patients were treated with SOF 400 mg, DACLA 60 mg and ribavirin 600 mg and 51 patients were treated with SOF 400 mg, LDV 90 mg and ribavirin 600 mg) for 12 weeks, during the treatment complete blood count, creatinine, bilirubin, alanine transaminase, aspartate transaminase and serum uric acid were monitored, HCV RNA quantitative PCR at 12 weeks after the end of treatment was done.ResultsResponse to treatment in SOF/LDV (sof/led) group is about (98%), response to treatment in SOF/DACLA (sof/dacla) group is about (96%). Hyperuricaemia was noticed in 17.6% of patients received sof/led and in 15.5% of those received sof/dacla.ConclusionSOF+LDV and SOF+DACLA plus ribavirin regimens are highly effective in treating chronic HCV patients with compensated liver cirrhosis. Hyperuricaemia is considered a potential adverse effect to DAAS containing ribavirin and may lead to serious side effects such as renal impairment.
Death rounds to support critical care nurses: a qualitative study
Authors: Ong Keh Kiong , Sum Chew Lai , Zhou Xuelian Jamie , Chow Yeow Leng 
Published: December 2020

ObjectiveProviding end-of-life care has a significant psychological impact on critical care nurses. Little is known about whether critical care nurses find death rounds useful as a support system. This study aimed to describe critical care nurses’ perceptions of attending death rounds.MethodsThis study was conducted using a qualitative descriptive design, using one-to-one audio-recorded interviews. The study was conducted at a 20-bed medical intensive care unit in a 1200-bed public tertiary hospital in Singapore. One-to-one interviews were conducted with 14 nurses using a semi-structured interview guide. Data was analysed using thematic analysis.ResultsCritical care nurses valued attending death rounds. They found death rounds to be an outlet to express themselves and remember patients, to draw and give peer support, to build nursing and interprofessional cohesiveness and to learn to improve palliative care. The death rounds were optimal when they felt safe to share, when there was a good facilitator, when the hierarchy was flat and when the audience was interdisciplinary. The barriers to a successful death round were the rounds being too formal, timing and not knowing the patients.ConclusionDeath rounds are a viable way to support critical care nurses in providing end-of-life care.
Bacterial O-GlcNAcase genes abundance decreases in ulcerative colitis patients and its administration ameliorates colitis in mice
Authors: He Xiaolong , Gao Jie , Peng Liang , Hu Tongtong , Wan Yu , Zhou Meijuan , Zhen Peilin , Cao Hong 
Published: December 2020

ObjectiveO-linked N-acetylglucosaminylation (O-GlcNAcylation), controlled by O-GlcNAcase (OGA) and O-GlcNAc transferase (OGT), is an important post-translational modification of eukaryotic proteins and plays an essential role in regulating gut inflammation. Gut microbiota encode various enzymes involved in O-GlcNAcylation. However, the characteristics, abundance and function of these enzymes are unknown.DesignWe first investigated the structure and taxonomic distribution of bacterial OGAs and OGTs. Then, we performed metagenomic analysis to explore the OGA genes abundance in health samples and different diseases. Finally, we employed in vitro and in vivo experiments to determine the effects and mechanisms of bacterial OGAs to hydrolyse O-GlcNAcylated proteins in host cells and suppress inflammatory response in the gut.ResultsWe found OGAs, instead of OGTs, are enriched in Bacteroidetes and Firmicutes, the major bacterial divisions in the human gut. Most bacterial OGAs are secreted enzymes with the same conserved catalytic domain as human OGAs. A pooled analysis on 1999 metagenomic samples encompassed six diseases revealed that bacterial OGA genes were conserved in healthy human gut with high abundance, and reduced exclusively in ulcerative colitis. In vitro studies showed that bacterial OGAs could hydrolyse O-GlcNAcylated proteins in host cells, including O-GlcNAcylated NF-κB-p65 subunit, which is important for activating NF-κB signalling. In vivo studies demonstrated that gut bacteria-derived OGAs could protect mice from chemically induced colonic inflammation through hydrolysing O-GlcNAcylated proteins.ConclusionOur results reveal a previously unrecognised enzymatic activity by which gut microbiota influence intestinal physiology and highlight bacterial OGAs as a promising therapeutic strategy in colonic inflammation.
Gravitational wave signatures of highly magnetized neutron stars
Authors: Flores Cesar V. , Lopes Luiz L. , Castro Luis B. , Menezes Débora P. 
Published: December 2020

AbstractMotivated by the recent gravitational wave detection by the LIGO–VIRGO observatories, we study the Love number and dimensionless tidal polarizability of highly magnetized stars. We also investigate the fundamental quasi-normal mode of neutron stars subject to high magnetic fields. To perform our calculations we use the chaotic field approximation and consider both nucleonic and hyperonic stars. As far as the fundamental mode is concerned, we conclude that the role played by the constitution of the stars is far more relevant than the intensity of the magnetic field, and if massive stars are considered, the ones constituted by nucleons only present frequencies somewhat lower than the ones with hyperonic cores. This feature that can be used to point out the real internal structure of neutron stars. Moreover, our studies clearly indicate that strong magnetic fields play a crucial role in the deformability of low mass neutron stars, with possible consequences on the interpretation of the detected gravitational waves signatures.
Extended multi-scalar field theories in $$(1+1)$$ dimensions
Authors: Aguirre A. R. , Souza E. S. 
Published: December 2020

AbstractWe present the explicit construction of some multi-scalar field theories in$$(1+1$$(1+1) dimensions supporting BPS (Bogomol’nyi–Prasad–Sommerfield) kink solutions. The construction is based on the ideas of the so-called extension method. In particular, several new interesting two-scalar and three-scalar field theories are explicitly constructed from non-trivial couplings between well-known one-scalar field theories. The BPS solutions of the original one-field systems will be also BPS solutions of the multi-scalar system by construction, and therefore we will analyse their linear stability properties for the constructed models.
Diagnostic Performance of a Novel Noninvasive Workup in the Setting of Dry Eye Disease
Authors: Vigo Luca , Pellegrini Marco , Bernabei Federico , Carones Francesco , Scorcia Vincenzo , Giannaccare Giuseppe 
Published: December 2020

Purpose. To evaluate the diagnostic performance of a novel noninvasive automated workup employed for the diagnosis of dry eye disease (DED). Methods. One hundred patients with mild to moderate DED and 100 matched control subjects were enrolled in this cross-sectional study. Ocular surface examinations were carried out by means of IDRA Plus (SBM Sistemi, Turin, Italy), which allows the automated evaluation of noninvasive breakup time (NIBUT), lipid layer thickness (LLT), tear meniscus height (TMH), infrared meibography for the measurement of meibomian gland loss (MGL), and blinking analysis. Continuous variables were compared between patients with DED and controls by using the Mann–Whitney U test. The area under the curve (AUC) of receiver operating characteristic curves was calculated. The correlations between ocular surface parameters were evaluated with Pearson correlation analysis. Results. Patients with DED showed significantly lower values of NIBUT, LLT, and TMH compared to controls (6.9 ± 2.5 vs 10.4 ± 2.4 s,

P

< 0.001; 64.6 ± 20.3 vs 73.4 ± 21.9 nm,

P

= 0.003; 0.231 ± 0.115 vs 0.289 ± 0.164,

P

= 0.012, respectively). Conversely, no significant differences were observed for MGL and blinking analysis (both

P

> 0.05). NIBUT had the highest diagnostic power (AUC = 0.841, sensitivity = 0.89, and specificity = 0.69), followed by LLT (AUC = 0.621, sensitivity = 0.89, and specificity = 0.55), TMH (AUC = 0.606, sensitivity = 0.57, and specificity = 0.63), blink analysis (AUC = 0.533, sensitivity = 0.48, and specificity = 0.59), and MGL (AUC = 0.531, sensitivity = 0.54, and specificity = 0.48). In patients with DED, NIBUT showed a significant correlation with TMH (R = 0.347,

P

= 0.002) and blinking analysis (R = 0.356,

P

< 0.001), while blinking analysis was negatively correlated with MGL (R = −0.315,

P

= 0.008). Conclusions. The automated noninvasive workup validated in this study may be a useful tool for reaching a noninvasive diagnosis of DED with a good performance, especially for NIBUT.
SAR439859, a Novel Selective Estrogen Receptor Degrader (SERD), Demonstrates Effective and Broad Antitumor Activity in Wild-Type and Mutant ER-Positive Breast Cancer Models
Authors: Shomali Maysoun , Cheng Jane , Sun Fangxian , Koundinya Malvika , Guo Zhuyan , Hebert Andrew T. , McManus Jessica , Levit Mikhail N. , Hoffmann Dietmar , Courjaud Albane , Arrebola Rosalia , Cao Hui , Pollard Jack , Lee Joon Sang , Besret Laurent , Caron Anne , Bangari Dinesh S. , Abecassis Pierre-Yves , Schio Laurent , El-Ahmad Youssef , Halley Frank , Tabart Michel , Certal Victor , Thompson Fabienne , McCort Gary , Filoche-Rommé Bruno , Cheng Hong , Garcia-Echeverria Carlos , Debussche Laurent , Bouaboula Monsif 
Published: December 2020

AbstractPrimary treatment for estrogen receptor-positive (ER+) breast cancer is endocrine therapy. However, substantial evidence indicates a continued role for ER signaling in tumor progression. Selective estrogen receptor degraders (SERD), such as fulvestrant, induce effective ER signaling inhibition, although clinical studies with fulvestrant report insufficient blockade of ER signaling, possibly due to suboptimal pharmaceutical properties. Furthermore, activating mutations in the ER have emerged as a resistance mechanism to current endocrine therapies. New oral SERDs with improved drug properties are under clinical investigation, but the biological profile that could translate to improved therapeutic benefit remains unclear. Here, we describe the discovery of SAR439859, a novel, orally bioavailable SERD with potent antagonist and degradation activities against both wild-type and mutant Y537S ER. Driven by its fluoropropyl pyrrolidinyl side chain, SAR439859 has demonstrated broader and superior ER antagonist and degrader activities across a large panel of ER+ cells, compared with other SERDs characterized by a cinnamic acid side chain, including improved inhibition of ER signaling and tumor cell growth. Similarly, in vivo treatment with SAR439859 demonstrated significant tumor regression in ER+ breast cancer models, including MCF7-ESR1 wild-type and mutant-Y537S mouse tumors, and HCI013, a patient-derived tamoxifen-resistant xenograft tumor. These findings indicate that SAR439859 may provide therapeutic benefit to patients with ER+ breast cancer, including those who have resistance to endocrine therapy with both wild-type and mutant ER.