Nanoscale Analysis of Frozen Water by Atom Probe Tomography Using Graphene Encapsulation and Cryo-Workflows: A Parametric Study

There has been an increasing interest in atom probe tomography (APT) to characterise hydrated and biological materials. A major benefit of APT compared to microscopy techniques more commonly used in biology is its combination of outstanding 3D spatial resolution (~0.2 nm) and mass sensitivity. APT has already been successfully used to characterise biological materials, revealing key structural information at the atomic scale, however there are many challenges inherent to the analysis of hydrated materials. New preparation protocols, often involving sample preparation and transfer at cryogenic temperature, enable APT analysis of hydrated materials and have the potential to enable 3D atomic scale characterisation of biological materials in the near-native hydrated state. In this study, APT specimens of pure water at the tips of tungsten needles were prepared at room temperature by graphene encapsulation. A parametric study was conducted where samples were transferred at either room temperature or cryo-temperature and analysed by APT by varying parameters such as the flight path and pulsing mode. The differences between the acquisition scenarios are presented along with recommendations for future studies

Understanding carbide evolution and surface chemistry during deep cryogenic treatment in high-alloyed ferrous alloy

The study investigates the effect of deep cryogenic treatment (DCT) on a high-alloyed ferrous alloy (HAFA) and its effectiveness on carbide evolution and chemical shifts of alloying elements. With ex-situ and in-situ observations ranging from the microscopic to the nanoscopic level, we uncover the atomistic mechanism by which DCT affects carbide precipitation, resulting in a 50% increase in carbide volume fraction. Synchrotron-based scanning photoelectron microscopy provides insight into the agglomeration of carbon during exposure to DCT. We find that Mo plays a crucial role in DCT through its modification of chemical bonding states, which is postulated to originate from the loosely-formed primordial Mo2C carbides formed during exposure to cryogenic temperatures. These in turn provide energetically favorable nucleation zones that accelerate the formation of M7C3 carbides, which serve as intermediate states for the formation of M23C6 carbides, which most strongly impact the mechanical properties. These results are supported by atom probe tomography, showing the preferential formation of Mo-rich M7C3 carbides in DCT samples, resulting from greater solute mobility. This work clarifies the fundamental mechanisms on how DCT affects HAFA, solving a long-elusive problem

The impact of tinnitus upon cognition in adults : a systematic review

OBJECTIVE : To systematically review and analyse experimental outcomes of studies exploring the impact of tinnitus upon cognitive function and their implications for clinical management of invasive tinnitus. DESIGN : A systematic and descriptive review. STUDY SAMPLE : Eighteen studies were identified investigating the impact of tinnitus on cognitive function. RESULTS : The 18 studies evaluated cognitive function using 24 different objective behavioural tests, nine electrophysiological recordings, one oculomotor test, and one self-report questionnaire. The studies spanned 18 years and revealed numerous interactions potentially contributing to the cognitive difficulties frequently reported by people with invasive tinnitus. The studies indicate a clear association between tinnitus and aspects of cognitive function, specifically the executive control of attention. CONCLUSIONS : Tinnitus impairs cognitive function by way of impact upon executive control of attention. Clinical management of patients reporting tinnitus and cognitive difficulties requires an understanding of the reciprocal relationship between tinnitus and cognitive function, with additive effects of anxiety, depression, and somatic cognitive bias. Further study is required to establish the impact of advancing age, hearing loss, anxiety, depression tinnitus duration, and distress upon cognitive function in people with invasive tinnitus.The authors would like to acknowledge the support of the Ear Science Institute Australia and the Lions Hearing Clinic.http://www.tandfonline.com/loi/iija202017-05-31hb2017Speech-Language Pathology and Audiolog

Investigating the prevalence and impact of device-related problems associated with hearing aid use

OBJECTIVE : To explore the prevalence of device-related problems associated with hearing aid use, participants’ help-seeking behaviours for these problems, and factors associated with hearing aid problems. DESIGN : A prospective convenience cohort design surveying 413 adult hearing aid users (34–97 years of age) recruited from seven clinics across Australia. RESULTS : Almost all participants (98%) indicated that they were experiencing at least one of the hearing aid problems included on the survey. The number of hearing aid related problems reported by participants ranged from 0 to 25 (of a possible 26), with a mean of 10 problems (SD = 5). The three most reported problems were related to difficulty hearing in noisy environments, hearing in windy environments, and understanding certain voices. Participants had reported less than half (46.33%) of the total problems identified to their clinic (range = 0–100%, mean = 43.40, SD = 13.92). Participants who reported experiencing a greater number of hearing aid problems also reported lower levels of hearing aid benefit, and satisfaction with their hearing aids. CONCLUSIONS : The majority of hearing aid owners experience problems with their hearing aids. Addressing these problems would likely contribute to improved hearing aid outcomes.Portions of this article were presented at the ACAud National Congress 2017, Adelaide, SA, August 2017, at the Audiology Australia Chapter conferences in Perth, Adelaide and Hobart, November 2017, at the HAASA National Conference, Sydney NSW, May 2018, and at the Audiology Australia National Congress, Sydney NSW, May 2018.Australian Postgraduate Award scholarship through The University of Western Australia.http://www.tandfonline.com/loi/iija20hj2021Speech-Language Pathology and Audiolog

The association between Alzheimer's Disease-Related markers and physical activity in cognitively normal older adults

Previous studies have indicated that physical activity may be beneficial in reducing the risk for Alzheimer's disease (AD), although the underlying mechanisms are not fully understood. The goal of this study was to evaluate the relationship between habitual physical activity levels and brain amyloid deposition and AD-related blood biomarkers (i.e., measured using a novel high-performance mass spectrometry-based assay), in apolipoprotein E (APOE) ε4 carriers and noncarriers. We evaluated 143 cognitively normal older adults, all of whom had brain amyloid deposition assessed using positron emission tomography and had their physical activity levels measured using the International Physical Activity Questionnaire (IPAQ). We observed an inverse correlation between brain amyloidosis and plasma beta-amyloid (Aβ)1−42 but found no association between brain amyloid and plasma Aβ1−40 and amyloid precursor protein (APP)669−711. Additionally, higher levels of physical activity were associated with lower plasma Aβ1−40, Aβ1−42, and APP669−711 levels in APOE ε4 noncarriers. The ratios of Aβ1−40/Aβ1−42 and APP669−711/Aβ1−42, which have been associated with higher brain amyloidosis in previous studies, differed between APOE ε4 carriers and non-carriers. Taken together, these data indicate a complex relationship between physical activity and brain amyloid deposition and potential blood-based AD biomarkers in cognitively normal older adults. In addition, the role of APOE ε4 is still unclear, and more studies are necessary to bring further clarification

Prevalence of Hyperacusis and Its Relation to Health: The Busselton Healthy Ageing Study

ImportanceThe prevalence of hyperacusis and its relationship with mental and general health is unknown in a nonclinical sample. Therefore, we aimed to determine the prevalence of hyperacusis and its relation with hearing, general and mental health in a population-based study.Study DesignProspective population-based study.Material and MethodsThis study uses data from the Busselton Healthy Ageing Study (BHAS). A sample of 5,107 eligible inhabitants aged 45 to 70 years completed a detailed questionnaire and a clinical assessment. A positive answer to “Do you consider yourself sensitive or intolerant to everyday sounds” was used to indicate hyperacusis. Logistic regression was used to examine the association between hearing, mental and general health factors, and hyperacusis.ResultsOf 5,107 participants, 775 (15.2%) reported hyperacusis. The majority of participants with hyperacusis reported an occasional effect on daily life (72.0%). Being female, older in age, having a lower income, physical or mental health difficulties, more severe hearing loss, and tinnitus were all associated with the presence of hyperacusis. Individuals who experience hearing impairment, poorer general or mental health have a higher possibility of hyperacusis having an effect on their daily life.ConclusionsIn this community population-based cohort study, we found a prevalence of hyperacusis of 15.2%. Individuals with hearing loss, mental health problems, and lower physical health have a higher possibility of experiencing effects on their daily life associated with their hyperacusis. Unravelling the relationship between hyperacusis hearing, general and mental health can be of major importance for a better understanding of the condition and its consequences.Level of EvidenceII-2 Laryngoscope, 202

Plasma amyloid‐beta levels in a pre‐symptomatic dutch‐type hereditary cerebral amyloid angiopathy pedigree: A cross‐sectional and longitudinal investigation

Plasma amyloid‐beta (Aβ) has long been investigated as a blood biomarker candidate for Cerebral Amyloid Angiopathy (CAA), however previous findings have been inconsistent which could be attributed to the use of less sensitive assays. This study investigates plasma Aβ alterations between pre‐symptomatic Dutch‐type hereditary CAA (D‐CAA) mutation‐carriers (MC) and non-carriers (NC) using two Aβ measurement platforms. Seventeen pre‐symptomatic members of a D‐ CAA pedigree were assembled and followed up 3–4 years later (NC = 8;MC = 9). Plasma Aβ1‐40 and Aβ1‐42 were cross‐sectionally and longitudinally analysed at baseline (T1) and follow‐up (T2) and were found to be lower in MCs compared to NCs, cross‐sectionally after adjusting for covari-ates, at both T1(Aβ1‐40: p = 0.001; Aβ1‐42: p = 0.0004) and T2 (Aβ1‐40: p = 0.001; Aβ1‐42: p = 0.016) employing the Single Molecule Array (Simoa) platform, however no significant differences were observed using the xMAP platform. Further, pairwise longitudinal analyses of plasma Aβ1‐40 revealed decreased levels in MCs using data from the Simoa platform (p = 0.041) and pairwise longitudinal analyses of plasma Aβ1‐42 revealed decreased levels in MCs using data from the xMAP platform (p = 0.041). Findings from the Simoa platform suggest that plasma Aβ may add value to a panel of biomarkers for the diagnosis of pre‐symptomatic CAA, however, further validation studies in larger sample sets are required

A blood-based biomarker panel indicates IL-10 and IL-12/23p40 are jointly associated as predictors of β-amyloid load in an AD cohort

Alzheimer\u27s Disease (AD) is the most common form of dementia, characterised by extracellular amyloid deposition as plaques and intracellular neurofibrillary tangles of tau protein. As no current clinical test can diagnose individuals at risk of developing AD, the aim of this project is to evaluate a blood-based biomarker panel to identify individuals who carry this risk. We analysed the levels of 22 biomarkers in clinically classified healthy controls (HC), mild cognitive impairment (MCI) and Alzheimer\u27s participants from the well characterised Australian Imaging, Biomarker and Lifestyle (AIBL) study of aging. High levels of IL-10 and IL-12/23p40 were significantly associated with amyloid deposition in HC, suggesting that these two biomarkers might be used to detect at risk individuals. Additionally, other biomarkers (Eotaxin-3, Leptin, PYY) exhibited altered levels in AD participants possessing the APOE ϵ4 allele. This suggests that the physiology of some potential biomarkers may be altered in AD due to the APOE ϵ4 allele, a major risk factor for AD. Taken together, these data highlight several potential biomarkers that can be used in a blood-based panel to allow earlier identification of individuals at risk of developing AD and/or early stage AD for which current therapies may be more beneficial

New public management through a glass darkly : a case study examining the impact of new public management on middle management development in the UK and Irish civil service

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