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INTRODUCTION: Tau is a key pathology in chronic traumatic encephalopathy (CTE). Here, we report our findings in tau positron emission tomography (PET) measurements from the DIAGNOSE CTE Research Project. METHOD: We compare flortaucipir PET measures from 104 former professional players (PRO), 58 former college football players (COL), and 56 same-age men without exposure to repetitive head impacts (RHI) or traumatic brain injury (unexposed [UE]); characterize their associations with RHI exposure; and compare players who did or did not meet diagnostic criteria for traumatic encephalopathy syndrome (TES). RESULTS: Significantly elevated flortaucipir uptake was observed in former football players (PRO+COL) in prespecified regions (p

Purpose: Chronic traumatic encephalopathy (CTE) has been diagnosed in 91.7% of retired United States National Football League (NFL) players at postmortem. There is no treatment or cure for CTE. Most living former NFL athletes with probable CTE suffer from obesity and its comorbidities. Our previous reviews document the improvement in cognition following metabolic/bariatric surgery (MBS) (e.g., gastric bypass, sleeve gastrectomy). These operations might reduce microglial maladaptive states, thereby attenuating neurodegeneration and CTE-like neurocognitive impairment. The study evaluated former NFL players' views on metabolic surgery in relation to reduction of obesity and CTE risk. Materials and Methods: An online multiple-choice questionnaire (30 items, 125 response options, 10-min completion) developed in the Research Electronic Data Capture (REDCap) system was sent to 1,014 athletes screened in 2017–2022 by the Living Heart Foundation. Results: From 2/2022 to 7/2023, of 700 surveys opened, 72 (10.3%) of the retired players responded. Mean age was 61.6 ± 12.6 years; 45.0% had the disease of obesity with a mean BMI 35.5 ± 4.6 kg/m2. Thirty-three percent reported ≥ 2 obesity-related comorbidities; 40.3% memory-related TBI symptoms; 66.7% ≥ 1 cognitive symptom; 85.0% believed MBS was safe and effective but were unlikely to elect MBS for weight management. Yet, 57.0% of the entire cohort, and 68.8% of players with obesity were more likely to elect MBS if it could also reduce CTE risk. Conclusions: Results of the study bode well for future research recruitment. Most surveyed retired NFL players with obesity believed MBS to be effective and would be more likely to undergo MBS if it also reduced CTE risk. [ABSTRACT FROM AUTHOR]

A new method is proposed to measure the linear coefficient of thermal expansion (CTE) of solid metals and ceramics of micron‐sized dimensions. This approach uses a focused ion beam (FIB) to extract and transfer a slab of the sample, typically (15–20) ×10 × (3–5) µm onto a Micro‐Electro‐Mechanical Systems (MEMS) in situ heating holder inside a scanning electron microscope (SEM). CTE is thereafter calculated by image correlating the change of length (ΔL) between the fiducial marks on the slab as a function of temperature, taking advantage of the temperature calibration of the MEMS heating holder and nanometre resolution of the scanning electron microscope. The CTE results are validated to be consistent with standard copper and silicon. We further demonstrate the method on a graphene platelet reinforced copper composite and a graphite filler phase isolated from a bulk sample, these represent materials that cannot be practically synthesised or isolated at the macro‐scale. Errors associated with the measurement are discussed. LAY DESCRIPTION: Coefficient of thermal expansion (CTE) is the relative length change of a material due to temperature change. When dissimilar materials are joined and subjected to temperature change, a mismatch of their CTEs could undermine the mechanical integrity of the joint. Measurement of the CTE of materials that cannot be synthesised at the macro‐scale or practically isolated is challenging with routine techniques. A new method is proposed to measure the linear coefficient of thermal expansion (CTE) of solid metals and ceramics of micron sized dimensions. This approach uses a focused ion beam (FIB) to extract and transfer a slab of the sample, typically (15–20) ×10 × (3–5) µm, onto an in situ heating holder inside a scanning electron microscope (SEM). The relative length change of the sample is then measured as a function of temperature which is enabled by the micro heating stage. We have verified the capability of the technique by successfully measuring the CTE of standard copper and silicon samples. We further demonstrate the method on an electro‐deposited graphene platelet reinforced copper composite and an isolated graphite filler phase which could not be practically measured by conventional methods. [ABSTRACT FROM AUTHOR]

Materials with a thermal expansion coefficient compatible with silicon carbide based ceramic matrix composites and low thermal conductivity at higher temperatures are crucial for developing environmental barrier coatings (EBCs) for aero-engines. Lately, high entropy silicate engineering has been a promising approach to develop optimized EBC materials. The solid solution reaction method was adopted for the fabrication of high entropy multicomponent (Dy 1/5 Er 1/5 Tm 1/5 Yb 1/5 Y 1/5) 2 SiO 5 or (5RE 1/5) 2 SiO 5 monosilicate. Scanning electron microscopy and X-ray diffraction show the homogenous distribution and a single-phase solution of (5RE 1/5) 2 SiO 5 monosilicate. Differential scanning calorimetry testing was done at 1450 °C which shows no exo/endothermic reaction has occurred. The value of the coefficient of thermal expansion (6 ppm/°C) up to temperature 1500 °C and low thermal conductivity values for (5RE 1/5) 2 SiO 5 monosilicate were observed (1.1–1.4 W/m°C) in the temperature range between 25 and 1500 °C. The water vapor corrosion resistance of (5RE 1/5) 2 SiO 5 monosilicate further confirms that the material is suitable for EBC applications due to the synergistic effect of different rare earth radii and stable crystal structure with a negligible weight loss value of 0.0005 mg/cm2 after 150 h corrosion time under 90 % H 2 O and 10 % O 2 at 1300 °C. The results of this work suggest that (5RE 1/5) 2 SiO 5 monosilicate can be used as a promising candidate for environmental barrier coatings. [ABSTRACT FROM AUTHOR]

To develop a high-temperature-resistant adhesive specifically for quartz glass, several groups of aluminum phosphate-based adhesives with different P/Al ratios and Si/B 4 C ratios were prepared, and the bonding performance and mechanism were systematically analyzed. Adding Si and B 4 C affected the decomposition process of phosphates, mainly in terms of the types of decomposition products and the crystal transformation of phosphates. Their addition avoided the generation of metaphosphate and improved the component stability of the adhesive matrix. The oxidation of Si and B 4 C brought about considerable quality compensation, which was crucial for maintaining the structural integrity of the adhesive layer. Besides, the oxidation products further reacted with the adhesive and quartz substrate to form ceramic or glass phases, significantly improving the bonding performance. When the P/Al ratio and Si/B 4 C ratio were 2:3 and 10:3, APSB adhesive presented the best performance. After curing at room temperature or pre-treatment at 1200 °C, the bonding strength reached 16.3 MPa and 14.6 MPa, respectively. After pre-treatment at 1200 °C, APSB could provide above 6 MPa in extreme environments with the range of RT∼1200 °C. The thermal shock resistance of APSB was superior to its thermal cycling resistance. After 10 thermal shocks at 600 °C, 800 °C, and 1000 °C, the bonding strength of APSB is 4.52 MPa, 4.33 MPa, and 7.33 MPa, respectively. Nevertheless, the CTE of APSB adhesive after sintering remained stable at 5.4 × 10−6 K−1, which was still significantly different from the CTE (0.5 × 10−6 K−1) of quartz glass. Therefore, there is great potential for developing low-expansion adhesives in the near future. [ABSTRACT FROM AUTHOR]

Abstract Career and technical education (CTE) is considered a key academic pathway for sustainable careers in several high-growth industries. However, African–American employees are underrepresented in these industries. Historically Black colleges and universities (HBCUs) may represent invaluable options to address this inequality. Our analysis of the Integrated Postsecondary Education Data System (IPEDS) suggests that HBCUs provide fewer CTE options than a matched sample of non-HBCUs. The most commonly available CTE programs appear in less than one-quarter of HBCUs, and nearly one-quarter of CTE industries are unrepresented. Although some programs are well-positioned to address African–American employee underrepresentation, others are completely absent. Findings connecting HBCU CTE programs to occupations with high projected growth or living wage salaries are also mixed. Overall, these results may be informative for academic policymakers, administrators, and students.

The cis- form of diaminodibenzocyclooctane (DADBCO, C16H18N2) is of interest as a negative coefficient of thermal expansion (CTE) material. The crystal structure was determined through single-crystal X-ray diffraction at 100 K and is presented herein.

AbstractMetalite is a new class of antisymmetric composite laminates composed of angle-plies, 0-degree, and 90-degree plies, presenting unique properties. These include extremely thin laminates suitable for minimum gauge applications, remarkable weight savings compared to conventional quads, adjustable zero and negative coefficients of thermal expansion (CTE), ease of manufacturing, excellent ability to adjust mode frequency, change sound radiation characteristics, and high tunability. In this study, Metalite laminates ranging from 3 to 8 plies are described using their feasible spaces and compared with quads, detailing the weight savings achieved for hard, soft, and neutral laminates. Through an experimental study, the CTE value of a hybrid Metalite is correlated with theory, demonstrating how to tune zero and negative CTE values. The proposed work offers significant benefits through practical solutions for designing and manufacturing lightweight composite laminates with unique properties. [ABSTRACT FROM AUTHOR]

This article discusses the topic of career education in the United States. It provides a brief history of Career Technical Education (CTE) along with legislative changes from the early 1900s to present day. Studies surrounding CTE in elementary to postsecondary school, along with notable benefits for students are presented. Benefits of early CTE programming increased graduation rates, indicated higher student attendance, showed higher academic engagement, and found students reported increased personal confidence and motivation, less stress, and enjoyment of meaningful learning opportunities. These findings were consistent across learners and school districts, irrespective of socioeconomic status. Middle school is identified as a significant time to implement CTE programs as students develop self-realization and self-exploration during adolescence. Despite Every Student Succeeds Act (ESSA) and Perkins V are federal laws calling for CTE programs at the middle and high school level, barriers to preventing successful implementation of such programs remain. To overcome such barriers, administrators and teachers are advised to provide appropriate professional development (PD), and being cognizant of the benefits associated with CTE programs. Overall, this article identifies the need for CTE in middle schools. [ABSTRACT FROM AUTHOR]

Career and technical education (CTE) is considered a key academic pathway for sustainable careers in several high-growth industries. However, African–American employees are underrepresented in these industries. Historically Black colleges and universities (HBCUs) may represent invaluable options to address this inequality. Our analysis of the Integrated Postsecondary Education Data System (IPEDS) suggests that HBCUs provide fewer CTE options than a matched sample of non-HBCUs. The most commonly available CTE programs appear in less than one-quarter of HBCUs, and nearly one-quarter of CTE industries are unrepresented. Although some programs are well-positioned to address African–American employee underrepresentation, others are completely absent. Findings connecting HBCU CTE programs to occupations with high projected growth or living wage salaries are also mixed. Overall, these results may be informative for academic policymakers, administrators, and students. [ABSTRACT FROM AUTHOR]

The present research presents an examination of the consequential effects brought about by the introduction of short-cut E-glass fibers (GF) on the properties of high-dielectric constant, high-thermal conductivity microwave composite systems (x GF/(8- x)BNNS/78 wt%ST/polyolefin, x = 0-8 wt%, BNNS: hexagonal boron nitride nanosheets). The GF is modified using KH550, with the success of the surface modification definitively confirmed by X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform infrared spectroscopy (FTIR). All components are found to exhibit consistently ultra-high and stable dielectric constants within the 8–12 GHz frequency range (D k = 17.7–18.08). Based on thermogravimetry analysis (TGA) and dynamic mechanical analysis (DMA) results, the incorporation of modified GF improve the thermal stability of the composite materials, enhancing thermal decomposition temperature, residual carbon content and glass transition temperature. Furthermore, replacing BNNS with GF significantly amplifies the mechanical properties of the composite substrate. This substitution leads to a notable reduction in the coefficient of thermal expansion (CTE) in all directions while simultaneously increasing the bending and tensile strength. At the same time, the composites can maintain reasonably high thermal conductivity values. Overall, with a GF concentration of 4 wt%, the composite showcases an appreciable increase in dielectric constants (17.81), a high thermal conductivity (1.3 W/m·K) and enhances mechanical properties (cross-plane CTE: 15.44 μm/(m·°C), in-plane CTE: 26.06 μm/(m·°C), bending strength: 65.6 MPa, tensile strength: 17.42 MPa). Considering its superior performance metrics, the composite can be identified as an optimal choice for microwave composite dielectric substrate material. [ABSTRACT FROM AUTHOR]

Background and purpose: Chronic traumatic encephalopathy (CTE) has gained widespread attention due to its association with multiple concussions and contact sports. However, CTE remains a postmortem diagnosis, and the link between clinical symptoms and CTE pathology is poorly understood. This study aimed to investigate the presence of copathologies and their impact on symptoms in former contact sports athletes. Methods: This was a retrospective case series design of 12 consecutive cases of former contact sports athletes referred for autopsy. Analyses are descriptive and include clinical history as well as the pathological findings of the autopsied brains. Results: All participants had a history of multiple concussions, and all but one had documented progressive cognitive, psychiatric, and/or motor symptoms. The results showed that 11 of the 12 participants had evidence of CTE in the brain, but also other copathologies, including different combinations of tauopathies, and other rare entities. Conclusions: The heterogeneity of symptoms after repetitive head injuries and the diverse pathological combinations accompanying CTE complicate the prediction of CTE in clinical practice. It is prudent to consider the possibility of multiple copathologies when clinically assessing patients with repetitive head injuries, especially as they age, and attributing neurological or cognitive symptoms solely to presumptive CTE in elderly patients should be discouraged. [ABSTRACT FROM AUTHOR]

Drilling deviated wellbores has raised concerns about proper cutting transport. Cuttings settling downhole can create stationary cutting beds, causing drilling mishaps like stuck pipes. High fluid velocity is typically required to efficiently erode a stationary bed, but this is constrained by hydraulic and wellbore geometry. When this occurs, pipe rotation can erode the bed mechanically and enable efficient cutting transport even with lower fluid velocities. Therefore, this study formulated water-based mud (WBM) with hydroxyapatite nanoparticles (n-HAp) to examine the effect of pipe rotation on cutting transport in deviated wells. It was compared with copper II oxide nanoparticles (CuO NP) in terms of rheology, filtration, and cutting transfer efficiency (CTE). The CTE of n-HAp amounts (0.4–2.0 g) in moving cuttings with diameters of 0.80 to 3.60 mm through deviated wellbores of 40 to 65° at a 3.5 m/s fluid velocity with 60 and 120 rpm pipe rotation speeds was determined. Compared with CuO NP, n-HAp findings demonstrated enhanced rheology and CTE. However, for fluid loss control, n-HAp was slightly less effective compared to CuO NP. For all deviated angles, n-HAp increased the CTE by 9.5–50%, while CuO NP increased it by 3.4–38.7% at 120 rpm. Compared with 60 rpm, a higher CTE occurred at 120 rpm. Moreover, CTE occurs in the following manner: 40° > 65° > 45° > 60° > 50° > 55°. It suggests that stationary bed formation is more likely to occur at inclinations of 50–55°. These findings are crucial for drilling deviated wells. [ABSTRACT FROM AUTHOR]

The cis- form of diaminodibenzocyclooctane (DADBCO, C16H18N2) is of interest as a negative coefficient of thermal expansion (CTE) material. The crystal structure was determined through single-crystal X-ray diffraction at 100 K and is presented herein [ABSTRACT FROM AUTHOR]

There is litigation in respect of dementia in ex-rugby football players. The allegation is that these ex-players have suffered a traumatic encephalopathy syndrome causing dementia and other neurological problems. The syndrome is alleged to have been caused by repeated concussion during play. It is alleged that governing bodies of rugby should have been aware, and players should have been warned, of this risk. The dilemma, for both claimants and defendants, is that there is no agreed definition of the syndrome nor are there any diagnostic tests that confirm or refute this diagnosis. This paper reviews the literature of traumatic encephalopathy syndrome and when governing bodies were aware of the possibility of rugby concussion causing dementia. The legal principles are discussed and a framework for determining the probability of an ex-rugby player having the syndrome is proposed. [ABSTRACT FROM AUTHOR]

TDI CMOS image sensors are the most widely used photodetectors in space earth observation and multispectral imaging. The displacement damage caused by high-energy proton irradiation in the space environment leads to the continuous degradation of TDI CMOS image sensor parameters, seriously affecting its performance, reliability, and service life. This paper focuses on a space-based TDI CMOS image sensor chip and carries out 3 MeV proton irradiation tests and post-irradiation annealing tests to obtain the change rules of optical and electrical parameters. The degradation mechanism of sensitive parameters of TDI CMOS image sensors caused by proton irradiation is analyzed, and the sensitive region of proton displacement damage are discussed. The study demonstrates that after proton irradiation, the parameters especially full well capacity and temporal dark noise of the device degrade less, with small sensitivity to proton irradiation. However, the dark current, CTE, and pixel column FPN significantly degrade, and the degree of degradation is linearly related to the proton irradiation dose. In addition, the test also obtained the short-term and long-term annealing changes of sensitive parameters after proton irradiation of TDI CMOS image sensors, providing scientific advice for TDI CMOS image sensors space proton radiation effect tests and evaluations. The research results of this paper provide important references for the evaluation of radiation effects, on-orbit performance estimation, and radiation resistance reinforcement of space-based TDI CMOS image sensors. [ABSTRACT FROM AUTHOR]

The cis- form of diaminodibenzocyclooctane (DADBCO, C16H18N2) is of interest as a negative coefficient of thermal expansion (CTE) material. The crystal structure was determined through single-crystal X-ray diffraction at 100 K and is presented herein. [ABSTRACT FROM AUTHOR]

With the ever-growing emphasis on global decarbonization and rapid increases in the power densities of electronics equipment in recent years, new methods and lightweight materials have been developed to manage heat load as well as interfacial stresses associated with coefficient of thermal expansion (CTE) mismatches between components. The Al–Si system provides an attractive combination of CTE performance and high thermal conductivity whilst being a very lightweight option. Such materials are of interest to industries where thermal management is a key design criterion, such as the aerospace, automotive, consumer electronics, defense, EV, and space sectors. This paper will describe the development and manufacture of a family of high-performance hypereutectic Al–Si alloys (AyontEX™) by a powder metallurgy method. These alloys are of particular interest for structural heat sink applications that require high reliability under thermal cycling (CTE of 17 μm/(m·°C)), as well as reflective optics and instrument assemblies that require good thermal and mechanical stability (CTE of 13 μm/(m·°C)). Critical performance relationships are presented, coupled with the microstructural, physical, and mechanical properties of these Al–Si alloys. [ABSTRACT FROM AUTHOR]

In this study, two kinds of atomized Ag-20 wt%Si and Ag-50 wt%Si particles are fabricated and added to Ag paste to fabricate composite pastes to achieve a low coefficient of thermal expansion (CTE), and their performance stability in SiC power module is evaluated under thermal shock from −50 to 250 °C. Four kinds of composite Ag pastes using the two kinds of atomized Ag-Si addition with 10 % and 30 % were obtained, AS20-10, AS50-10, AS20-30 and AS50-30, respectively. The results show that the CTE reduction intensifies with increasing Ag-Si atomized particle content. The retention ratio of shear strength of AS20-30 sintered joint after 1000 cycles was 102.3 %, which means the shear strength did not decrease during so harsh thermal shock test. The mechanism was discussed in detail. In addition, the properties such as thermal conductivity and electrical conductivity for the composite pastes were also evaluated to gain a more comprehensive understanding for the new materials especially for the design of SiC power modules with a long-time life. Comprehensively considering the material parameters of the composite pastes and the reliability of the sintered joints under thermal shock, the optimized composite pastes as die attach material in power electronics are obtained. The findings should be inspiring in developing novel die attach materials for high reliable interconnections in SiC power modules.

Traditional integrated circuit (IC) packaging materials and printed circuit board substrate materials suffer from several limitations including low thermal conductivity, high coefficient of thermal expansion (CTE), and poor dielectric properties. Although significant efforts have been made to enhance these properties, achieving a single composite system with simultaneous high thermal conductivity, extremely low CTE, and dielectric loss remains a formidable task. In this study, we propose a hybrid polymer composite system that addresses these challenges. Our approach involves utilizing a thermosetting polyphenylene oxide (PPO) as the resin matrix, while incorporating boron nitride (BN) sheets with high thermal conductivity and alumina (Al2O3) spheres with favorable fluidity as fillers. To optimize the composite properties, the filler surfaces are modified using dopamine and silane coupling agents, ensuring proper interface control. The composites exhibit significant improvements in thermal conductivity, reduced dielectric loss and CTE, while maintaining excellent processibility. Specifically, with a composition of 25 vol% BN and 25 vol% Al2O3, the thermal conductivity of the composite reaches 2.18 W·m−1 K−1, surpassing neat PPO resin by a factor of 10.9. Simultaneously, the CTE decreases from 2.27% to 1.18% between 50 and 260°C, and the dielectric loss reduces from 0.0024 to 0.0011 at 10 GHz, as compared to neat PPO resin. Highlights: The reported novel hybrid composite offers a promising solution to the limitations of traditional IC packaging materials.The reported hybrid composite exhibits significantly improved thermal conductivity, ultralow dielectric loss, and reduced coefficient of thermal expansion, while maintaining excellent processibility.The thermal conductivity of the composites reaches 2.18 W·m−1 K−1, surpassing that of the neat resin by a factor of 10.9, meanwhile the dielectric loss is as low as 0.0011 at 10 GHz, which is extremely difficult to achieve simultaneously for thermosetting polymer composites.Synergetic effects were realized with the hybridization of fillers with different dimensionality, and proper filler surface modification. [ABSTRACT FROM AUTHOR]

To raise the operating temperature of Si-based ceramic matrix composites (CMCs), thermal/environmental barrier coating (T/EBCs) materials, typically rare earth silicates are applied. However, the high thermal conductivity of each single silicate possible coating option and the mismatch of thermal expansion present a significant barrier in the development of novel materials to offer thermal insulation and environmental protection to CMCs. The entropy engineering is used to create a multicomponent equi-atomic single-phase pyro silicate with extremely low thermal conductivity and enhanced water vapor corrosion resistance at 1300 °C in 90% H 2 O and 10% O 2 environment, specifically (Yb 0.25 Er 0.25 Tm 0.25 Sc 0.25) 2 Si 2 O 7. X-ray diffraction patterns confirms monophase formation and the thermal parameters such as specific heat capacity, thermal expansion and thermal diffusivity were determined and microstructures were described using scanning electron microscopy before and after water vapor corrosion. The ultra-low thermal conductivity of high entropy disilicates 0.90 W/m.°C at 1000 °C and very low value of weight loss 0.0014 g/cm2 is observed after 150 h corrosion time which is not reported before for even single or multicomponent high entropy rare earth disilicates. [ABSTRACT FROM AUTHOR]

This panel discusses how to challenge the status quo and create alternative career opportunities, especially for diverse talent. Through career technical education programs and the development of a registered youth apprenticeship for Animation, VFX, and Game Design, young people will have access to industry training as a part of their free and public education.

In this study, C-B-A and G-B-A new hybrid composites are produced by compression molding using Carbon (C), Basalt (B), Aramid (A), and Glass (G) fibers, and the produced samples are scanned using micro-computed tomography and Micro-CT. The coefficient of thermal expansion (CTE), glass transition temperature (Tg), and dimensional changes are determined by Thermomechanical Analysis (TMA) technique and thus the limits of thermal expansion and contraction dimensions, softening, and thermomechanical properties of newly produced hybrid composites are determined. In addition, the produced composites are exposed to UV radiation in different cycles and the results are compared with UV radiation non-exposed samples. [ABSTRACT FROM AUTHOR]

Chronic traumatic encephalopathy (CTE) is a neurodegenerative condition, in which the only known cause is exposure to repeated episodes of blunt head trauma. It most often occurs in professional and amateur athletes who have had frequent and repetitive cranial impacts during contact sports, but may also be found in victims of domestic violence, military personnel exposed to explosive devices and in individuals with severe epilepsy. The pathognomonic pathological findings are of neurofibrillary tangles and pretangles in the depths of the cerebral sulci caused by perivascular accumulation of phosphorylated Tau (pTau). Cases may be high profile requiring an evaluation of whether the neuropathological findings of CTE can be related to injuries previously sustained on the sporting field. Failure to examine the brain or to adequately sample appropriate areas at autopsy may lead to cases being overlooked and to an underestimation of the incidence of this condition in the community. Performing immunohistochemical staining for pTau in three areas from the neocortex has been found to be a useful screening tool for CTE. Ascertaining whether there is a history of head trauma, including exposure to contact sports, as a standard part of forensic clinical history protocols will help identify at-risk individuals so that Coronial consideration of the need for brain examination can be appropriately informed. Repetitive head trauma, particularly from contact sport, is being increasingly recognized as a cause of significant preventable neurodegeneration. [ABSTRACT FROM AUTHOR]

In this study, Si3N4 nanowires (NWs) with ceramic properties were incorporated into Sn1.0Ag0.5Cu (SAC105) solder to enhance its overall performance. The thermal properties, spreading behavior, microstructure, interface, and mechanical properties of SAC105-xSi3N4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0 wt%) solders were systematically investigated. The research revealed that doping Si3N4 NWs into SAC105 solder could expand its melting range and decrease undercooling. Notably, the solder alloy containing 0.6 wt% Si3N4 NWs had the lowest thermal expansion coefficient (CTE), which improved the CTE matching of SAC105 solder with Cu substrate. Although the solder with 0.4 wt% Si3N4 NWs exhibited superior wetting properties, it was less effective in refining the microstructure and interfacial intermetallic compounds (IMC) than those containing 0.6 wt% Si3N4 NWs. Meanwhile, when the β-Sn phase in the matrix and the Cu6Sn5 IMC phase at the interface were analyzed by electron back scatter diffraction (EBSD), their grain orientation was found to be optimized by the doping of 0.6 wt% Si3N4 NWs. The direction of the β-Sn grains of SAC105-0.6Si3N4 was perpendicular to the Cu substrate, showing a texture structure. The grain orientation of the interfacial Cu6Sn5 IMC made it well-adapted for three-dimensional (3D) packaging. Finally, the mechanical properties enhancement of the solder joints were analyzed in detail by combining the fracture morphology and the EBSD results of the Sn matrix.

With the ever-growing emphasis on global decarbonization and rapid increases in the power densities of electronics equipment in recent years, new methods and lightweight materials have been developed to manage heat load as well as interfacial stresses associated with coefficient of thermal expansion (CTE) mismatches between components. The Al–Si system provides an attractive combination of CTE performance and high thermal conductivity whilst being a very lightweight option. Such materials are of interest to industries where thermal management is a key design criterion, such as the aerospace, automotive, consumer electronics, defense, EV, and space sectors. This paper will describe the development and manufacture of a family of high-performance hypereutectic Al–Si alloys (AyontEX™) by a powder metallurgy method. These alloys are of particular interest for structural heat sink applications that require high reliability under thermal cycling (CTE of 17 μm/(m·°C)), as well as reflective optics and instrument assemblies that require good thermal and mechanical stability (CTE of 13 μm/(m·°C)). Critical performance relationships are presented, coupled with the microstructural, physical, and mechanical properties of these Al–Si alloys.

Repetitive mild traumatic brain injuries (rmTBI) may contribute to the development of neurodegenerative diseases through secondary injury pathways. Acetyl-Lcarnitine (ALC) shows neuroprotection through anti-inflammatory effects and via regulation of neuronal synaptic plasticity by counteracting post-trauma excitotoxicity. This study aimed to investigate mechanisms implicated in the etiology of neurodegeneration in rmTBI mice treated with ALC. Adult male C57BL/6J mice were allocated to sham, rmTBI or ALC + rmTBI groups. 15 rmTBIs were administered across 23 days using a modified weight drop model. Neurological testing and spatial learning and memory assessments via the Morris Water Maze (MWM) were undertaken at 48 h and 3 months. RT-PCR analysis of the cortex and hippocampus was undertaken for MAPT, GFAP, AIF1, GRIA, CCL11, TDP43, and TNF genes. Gene expression in the cortex showed elevated mRNA levels of MAPT, TNF, and GFAP in the rmTBI group that were reduced by ALC treatment. In the hippocampus, mRNA expression was elevated for GRIA1 in the rmTBI group but not the ALC + rmTBI treatment group. ALC treatment showed protective effects against the deficits displayed in neurological testing and MWM assessment observed in the rmTBI group. While brain structures display differential vulnerability to insult as evidenced by location specific postimpact disruption of key genes, this study shows correlative mRNA neurodegeneration and functional impairment that was ameliorated by ALC treatment in several key genes. ALC may mitigate damage inflicted in the various secondary neurodegenerative cascades and contribute to functional protection following rmTBI. [ABSTRACT FROM AUTHOR]

The functionalized multi‐walled carbon nanotubes (MWCNTs) (0.5–5 wt.%) are compounded with high density polyethylene (HDPE), and, subsequently, used for extruding nanocomposite filaments to fabricate nanocomposites (NCs) and functionally graded nanocomposites (FGNCs) through 3D printing. The 3D printed NCs are investigated for coefficient of thermal expansion (CTE), and buckling under different non‐uniform temperature distributions (case‐1: left edge heating, case‐2: centre heating, and case‐3: left and right edge heating). A significant reduction in CTE is observed with MWCNT addition and gradation. The highest reduction in CTE is observed for H5 (5 wt.% of MWCNT in HDPE) NC and H1 ⟶ H3 ⟶ H5 (FGNC‐2) among the NCs and the FGNCs. It is noted that Tcr (critical buckling temperature) is highest for case‐3 and lowest for case‐2. The highest deflection is noticed in case‐2, while no significant difference is observed in case‐1 and case‐3 heating conditions. It is also observed that Tcr increases with gradation and MWCNTs addition. The H5 NC and FGNC‐2 exhibited the highest Tcr among the NCs and FGNCs, respectively. The maximum deflection is noticed for HDPE, whereas the minimum deflection is noticed for FGNC‐2 and H‐5 NC among the tested samples. The results also revealed that Tcr is very sensitive to type of heating. [ABSTRACT FROM AUTHOR]

Chronic Traumatic Encephalopathy (CTE) is a neurodegenerative disease consistently associated with repetitive traumatic brain injuries (TBIs), which makes multiple professions, such as contact sports athletes and the military, especially susceptible to its onset. There are currently no approved biomarkers to diagnose CTE, thus it can only be confirmed through a post-mortem brain autopsy. Several imaging and cerebrospinal fluid biomarkers have shown promise in the diagnosis. However, blood-based biomarkers can be more easily obtained and quantified, increasing their clinical feasibility and potential for prophylactic use. This article aimed to comprehensively review the studies into potential blood-based biomarkers of CTE, discussing common themes and limitations, as well as suggesting future research directions. While the interest in blood-based biomarkers of CTE has recently increased, the research is still in its early stages. The main issue for many proposed biomarkers is their lack of selectivity for CTE. However, several molecules, such as different phosphorylated tau isoforms, were able to discern CTE from different neurodegenerative diseases. Further, the results from studies on exosomal biomarkers suggest that exosomes are a promising source of biomarkers, reflective of the internal environment of the brain. Nonetheless, more longitudinal studies combining imaging, neurobehavioral, and biochemical approaches are warranted to establish robust biomarkers for CTE. [ABSTRACT FROM AUTHOR]

The implementation of environment friendly technologies in microelectronic packaging industry has widened the essentialities of lead-free solder alloys. The Cu3Sn intermetallic compound is blameworthy for the adverse influences of the mechanical and thermal properties of the lead-free solder alloys. This study explored the effects of crystal size and direction on mechanical and thermal deformation behavior of Cu3Sn using the modified embedded atom method (MEAM) parameter in molecular dynamics simulation. The stress–strain characteristics were tracked down at 25 °C temperature and 1010 s−1 strain rate, and the thermal deformation manner was observed from −100 °C to 200 °C temperature, which came up with the thermal expansion coefficient (CTE). Investigations show that the tensile properties differ 43–63 % owing to anisotropy, whereas the CTE varies only less than 1 %. Meanwhile, the tensile properties and CTE plummet topmost 25 % and 58 % consecutively throughout the crystal size. However, the thermal expansion proclivity in different crystal size was quite indistinguishable at higher temperature.

Bovids are notorious for their high-force headbutting fights for herd dominance. Here, I discuss the evolutionary tradeoff between headbutting and brain damage incurred by bovids' reproductive strategy. The specific behavioral and neuroanatomical adaptations of these animals are placed in context of the neuropathology of repetitive brain trauma. [ABSTRACT FROM AUTHOR]

Repetitive mild traumatic brain injuries (rmTBI) may contribute to the development of neurodegenerative diseases through secondary injury pathways. Acetyl-L-carnitine (ALC) shows neuroprotection through anti-inflammatory effects and via regulation of neuronal synaptic plasticity by counteracting post-trauma excitotoxicity. This study aimed to investigate mechanisms implicated in the etiology of neurodegeneration in rmTBI mice treated with ALC. Adult male C57BL/6J mice were allocated to sham, rmTBI or ALC + rmTBI groups. 15 rmTBIs were administered across 23 days using a modified weight drop model. Neurological testing and spatial learning and memory assessments via the Morris Water Maze (MWM) were undertaken at 48 h and 3 months. RT-PCR analysis of the cortex and hippocampus was undertaken for MAPT, GFAP, AIF1, GRIA, CCL11, TDP43, and TNF genes. Gene expression in the cortex showed elevated mRNA levels of MAPT, TNF, and GFAP in the rmTBI group that were reduced by ALC treatment. In the hippocampus, mRNA expression was elevated for GRIA1 in the rmTBI group but not the ALC + rmTBI treatment group. ALC treatment showed protective effects against the deficits displayed in neurological testing and MWM assessment observed in the rmTBI group. While brain structures display differential vulnerability to insult as evidenced by location specific postimpact disruption of key genes, this study shows correlative mRNA neurodegeneration and functional impairment that was ameliorated by ALC treatment in several key genes. ALC may mitigate damage inflicted in the various secondary neurodegenerative cascades and contribute to functional protection following rmTBI.

Abstract Objective: Chronic Traumatic Encephalopathy (CTE) has received significant media coverage as a major health concern for collision sport athletes and combat veterans. This survey study investigated neuropsychologists’ perspectives of CTE.Methods: Neuropsychologists (N = 325) were contacted via electronic advertisement posted to popular neuropsychology professional listservs and completed a survey regarding their perspectives of: the proposed sequelae of repeated concussions, the strength of the CTE research base, and its media coverage.Results: Most respondents (91%) were at least somewhat familiar with the concept of CTE. Moderate uncertainty was reported (i.e. up to 30%) regarding the effects of repeated concussions. Most felt the research in support of CTE was unreliable (80%) and weak regarding claims that repeated concussions cause CTE (91%), independently cause behavioral/emotional/cognitive dysfunction (86%), or increase the risk for neurodegeneration (79%). Respondents agreed patients are concerned about CTE (92%), concerns are influenced by the media (96%) that presents a biased/alarmist view of CTE (96%), and patient recovery is influenced by their CTE beliefs (82%).Conclusions: There was strong agreement that the media presents an alarmist/biased view of CTE that influences patients concerns and outcomes following concussion. This presentation is incongruent with the perceptions of surveyed neuropsychologists who find the research in support of CTE to be weak and unreliable. More research is needed to determine the potential effects of repeated (sub)concussive events. As public knowledge will continue to be influenced by the media and health care professionals, future research should explore CTE perceptions across other health care disciplines. [ABSTRACT FROM AUTHOR]

Lightweight composite materials for potential thermal applications are the contemporary demand for manufacturing and aircraft industries where the possibility to improve and tailor the desired properties is based on the application. Carbonized eggshell powder is a solid lubricant with absorbent capability and has proven as a reinforcement for metallic base composites. In the present work, an attempt is made to investigate the effect of carbonized chicken eggshell powder (3 to 9% by weight) on the microstructural and thermal properties of Al7075 alloy processed by solid-state friction stir processing. An infrared thermography and three K-type thermocouples equipped with the base plate at three equal distances are used to measure the temperature with respect to time. The comparative study of microstructure and grain structure analysis has been done by light microscopy, scanning electron microscopy, and electron backscattered diffraction methods. The findings explored the dynamic recrystallization and grain recovery with a reduced grain size of 6.2 to 10.3 µm at a varying percentage of eggshell powder (3 to 9%) in the stir zone. The thermal conductivity and coefficient of thermal expansion (CTE) were measured for the temperature range of 50 to 400 °C. In addition to it, differential thermal analysis (DTA), thermo-gravimetric analysis (TGA), and derivative thermo-gravimetric analysis (DTG) are conducted for the temperature range of 25 to 900 °C to discuss the endothermic, exothermic nature, and degradation characteristics. The result revealed the decreasing trend of thermal conductivity, and CTE values were found in the range of 97 to 53 W/mK and 26.6 to 24 × 10−6 K−1 (heating cycle), 27.2 to 23.8 × 10−6 K−1(cooling cycle), respectively. Furthermore, the higher and lower thermal conductivity of 108 W/mK and 62 W/mK is observed at higher and lower terminal voltages, 250 V and 100 V, respectively. The DTA, TGA, and DTG curves explored the maximum weight loss, which varies up to 5.25% with exothermic peaks and decomposition steps for each surface composite. [ABSTRACT FROM AUTHOR]

In this study, sintering experiments were carried out on SrO-CaO-ZnO-Al2O3-B2O3- SiO2-TiO2 glass system with varying temperature, time and heating rates. The density of samples increases with the increase in temperature from 750 to 850°C. Thereafter, significant improvement in density is not noticed. The dwell time and heating rate have no marked impact on the improvement in density. From 850°C onwards, samples exhibit the peaks of crystalline phases confirmed by XRD. SEM images show the progressive increase in the compactness of microstructure with the reduction in porosity. The increase in HV with the increase in sintering temperature is attributed to the simultaneous increase in density. The highest hardness was obtained for the sample sintered within 850-950°C for 1h and a heating rate of 8°C/min. The Young's modulus is found to be of similar trend, like hardness. The CTE of annealed and sintered glass is 10.2 x 10-6 and 9.8 x 10-6/°C, respectively. [ABSTRACT FROM AUTHOR]

The Th–6wt%U–4wt%Zr alloy—a prospective thorium based metallic fuel for fast reactor applications, has been studied for its microstructural, thermal and elastic properties. The X-ray diffractometer of the alloy annealed at 1423 K and quenched showed α-thorium peaks and shrinkage in lattice parameter as compared to thorium. The scanning electron microscope attached to energy dispersive spectroscope revealed uranium rich precipitates dispersed in α-thorium matrix. The Coefficient of thermal expansion (CTE) of the alloy showed a change in slope at 939 K which corresponds to onset of α-U ⇋ β-U phase transformation along with α-thorium phase. The CTE of the alloy was 12.2 × 10–6/K at 1000 K which is comparatively less than uranium alloys fuels. Vickers hardness and elastic properties measurement showed an increase in strength of the alloy due to solid solution strengthening as compared to thorium. [ABSTRACT FROM AUTHOR]

In this work, the thermal stability of a BaO–CaO–SiO 2 –B 2 O 3 glass sealant, named "H", was investigated by differential scanning calorimetry (DSC). The crystallization behavior of glass H as the sealant matrix was investigated by a combination of experimental X-ray diffraction (XRD) analysis and thermodynamic simulation with the FactSage package. A good agreement was found between the Rietveld refinement of XRD experiments and the FactSage simulation. Particular attention was also given to the influence of the Sr 2 SiO 4 filler added to the glass matrix "H" on the thermal expansion and microstructures of glass-Sr 2 SiO 4 composites by means of dilatometry and scanning electron microscopy (SEM). The reinforced 20 wt% Sr 2 SiO 4 composite (HS2S20) showed excellent properties and, thus, its joining performance was investigated using SrTi 0.75 Fe 0.25 O 3-δ (STF25) and Aluchrom as promising oxygen transport membrane (OTM) and counterpart, respectively. The joining behaviors were investigated by comparing different joining temperatures. 920 °C is the best joining temperature for HS2S20 sealant. [ABSTRACT FROM AUTHOR]

Examining former athletes' health‐related beliefs and behaviors on the long‐term effects of concussions and potentially developing chronic traumatic encephalopathy (CTE) offers a domain to understand how men renegotiate their masculinities. In this paper, we explore how the cultural production of the concussion crisis shapes the ways in which men athletes make sense of self and their masculinity in the face of declining health. Drawing on in‐depth interviews with 27 male, former athletes, this article examines the multiple ways in which gender shapes their experience and treatment of traumatic brain injuries or suspected CTE. We show how men are re‐negotiating their aging masculinities through illness narratives and how the cultural production of the concussion crisis in sports shapes these narratives. We break down our analysis into three sections: (1) reflections of chaos narratives and stories of never‐aging masculinities, (2) the ways the concussion crisis shapes their restitution narratives, and (3) quest narratives combining never‐aging and aging masculinities. Whether or not these athletes have or are treated for CTE, we argue that they reformulate their masculinity to regain control over their manhood and to feel a sense of relief. [ABSTRACT FROM AUTHOR]

In this study, sintering experiments were carried out on SrO-CaO-ZnO-Al2O3-B2O3-SiO2-TiO2 glass system with varying temperature, time and heating rates. The density of samples increases with the increase in temperature from 750 to 850°C. Thereafter, significant improvement in density is not noticed. The dwell time and heating rate have no marked impact on the improvement in density. From 850°C onwards, samples exhibit the peaks of crystalline phases confirmed by XRD. SEM images show the progressive increase in the compactness of microstructure with the reduction in porosity. The increase in HV with the increase in sintering temperature is attributed to the simultaneous increase in density. The highest hardness was obtained for the sample sintered within 850-950°C for 1h and a heating rate of 8°C/min. The Young's modulus is found to be of similar trend, like hardness. The CTE of annealed and sintered glass is 10.2 × 10−6 and 9.8 × 10−6/°C, respectively.

Over the last 17 years, there has been a remarkable increase in scientific research concerning chronic traumatic encephalopathy (CTE). Since the publication of NINDS–NIBIB criteria for the neuropathological diagnosis of CTE in 2016, and diagnostic refinements in 2021, hundreds of contact sport athletes and others have been diagnosed at postmortem examination with CTE. CTE has been reported in amateur and professional athletes, including a bull rider, boxers, wrestlers, and American, Canadian, and Australian rules football, rugby union, rugby league, soccer, and ice hockey players. The pathology of CTE is unique, characterized by a pathognomonic lesion consisting of a perivascular accumulation of neuronal phosphorylated tau (p-tau) variably alongside astrocytic aggregates at the depths of the cortical sulci, and a distinctive molecular structural configuration of p-tau fibrils that is unlike the changes observed with aging, Alzheimer's disease, or any other tauopathy. Computational 3-D and finite element models predict the perivascular and sulcal location of p-tau pathology as these brain regions undergo the greatest mechanical deformation during head impact injury. Presently, CTE can be definitively diagnosed only by postmortem neuropathological examination; the corresponding clinical condition is known as traumatic encephalopathy syndrome (TES). Over 97% of CTE cases published have been reported in individuals with known exposure to repetitive head impacts (RHI), including concussions and nonconcussive impacts, most often experienced through participation in contact sports. While some suggest there is uncertainty whether a causal relationship exists between RHI and CTE, the preponderance of the evidence suggests a high likelihood of a causal relationship, a conclusion that is strengthened by the absence of any evidence for plausible alternative hypotheses. There is a robust dose–response relationship between CTE and years of American football play, a relationship that remains consistent even when rigorously accounting for selection bias. Furthermore, a recent study suggests that selection bias underestimates the observed risk. Here, we present the advances in the neuropathological diagnosis of CTE culminating with the development of the NINDS–NIBIB criteria, the multiple international studies that have used these criteria to report CTE in hundreds of contact sports players and others, and the evidence for a robust dose–response relationship between RHI and CTE. [ABSTRACT FROM AUTHOR]

Thermomechanical stress generation on a silicon chip in an embedded-die package (EDP) was investigated. Change in thermomechanical stress on the chip with temperature was evaluated using piezo-resistance gauges fabricated on the chip. To investigate the impact of a redistribution layer (RDL) on stress generation, an EDP where filling materials facing the top and bottom sides and the periphery of the embedded die were entirely removed was fabricated. The removal of filling materials was carried out by using the CO2 laser ablation technology. RDL having diagonal paths from the substrate to the chip was designed and fabricated in addition to the conventional orthogonal RDL. RDLs were made of copper. Temperature tests were carried out in the range from 260°C to 100°C. The experimental results indicate that, while the origin of thermomechanical stress is a mismatch in coefficients of thermal expansion (CTE) between the chip and the organic substrate, RDL plays a significant role in generating the thermomechanical stress on the chip. The results also show that the diagonal RDL design effectively reduces thermomechanical stress from the orthogonal RDL design owing to its spring characteristic. [ABSTRACT FROM AUTHOR]

Uses of aluminium (Al)-based metal matrix composites (MMCs) have been emerging in variety of applications since several decades. Hence, in the present study, hybrid Al-MMCs were developed using rice husk-extracted highly pure silica (SiO2) and commercial graphite (Grt) as reinforcing materials by powder metallurgical route followed by unique re-sintering. Effect of reinforcements on mechanical as well as thermal properties of Al-MMCs has been determined in this study by various tests. The microscopy, spectroscopy, and X-ray diffraction studies were conducted to characterize the purity and homogeneity of the composites. The hybrid MMCs had shown excellent physical and mechanical properties in terms of surface strength along with being light mass. The Vickers hardness (up to 250 MPa) and compressive strength (up to 341 MPa) of the hybrid nanocomposites has increased significantly on the addition of reinforcements. Thermal properties, including conductivity and linear expansion, were found to be lower for the composites compared to pure Al. Hence, the newly developed rice husk-extracted pure silica and graphite-reinforced hybrid Al-MMCs, particularly the samples of 5SiO2/5Grt/90Al (mass%), can be used as reliable potential materials for several advanced applications including, engine piston, automobile, aviation, and spacecraft components where both mechanical and thermal properties play vital role. [ABSTRACT FROM AUTHOR]

Of all our organs, the brain is perhaps the best protected from trauma. The skull has evolved to enclose it and, within the skull, the brain floats in a protective bath of cerebrospinal fluid. It is becoming evident, however, that head trauma experienced in young adult life can cause a dementia that appears decades later. The level of trauma that induces such destruction is still being assessed but includes levels well below that which cracks the skull or causes unconsciousness or concussion. Clinically this damage appears as dementia, in people who played body-contact sports in their youth or have survived accidents or the blasts of combat; and appears also, we argue, in old age, without a history of head trauma. The dementias have been given different names, including dementia pugilistica (affecting boxers), chronic traumatic encephalopathy (following certain sports, particularly football), traumatic brain injury (following accidents, combat) and Alzheimer’s (following decades of life). They share common features of clinical presentation and neuropathology, and this conceptual analysis seeks to identify features common to these forms of brain injury and to identify where in the brain the damage common to them occurs; and how it occurs, despite the protection provided by the skull and cerebrospinal fluid. The analysis suggests that the brain’s weak point in the face of trauma is its capillary bed, which is torn by the shock of trauma. This identification in turn allows discussion of ways of delaying, avoiding and even treating these traumainduced degenerations. [ABSTRACT FROM AUTHOR]

[Display omitted] The implementation of environment friendly technologies in microelectronic packaging industry has widened the essentialities of lead-free solder alloys. The Cu 3 Sn intermetallic compound is blameworthy for the adverse influences of the mechanical and thermal properties of the lead-free solder alloys. This study explored the effects of crystal size and direction on mechanical and thermal deformation behavior of Cu 3 Sn using the modified embedded atom method (MEAM) parameter in molecular dynamics simulation. The stress–strain characteristics were tracked down at 25 °C temperature and 1010 s−1 strain rate, and the thermal deformation manner was observed from −100 °C to 200 °C temperature, which came up with the thermal expansion coefficient (CTE). Investigations show that the tensile properties differ 43–63 % owing to anisotropy, whereas the CTE varies only less than 1 %. Meanwhile, the tensile properties and CTE plummet topmost 25 % and 58 % consecutively throughout the crystal size. However, the thermal expansion proclivity in different crystal size was quite indistinguishable at higher temperature. [ABSTRACT FROM AUTHOR]