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The real part of the relative permittivity, ϵ', and dielectric loss, tan δ, have been determined at audio frequencies at temperatures from about 5K to 350K for nano-composites composed of BaTiO3 nanoparticles and polycarbonate. The room temperature breakdown strength was also measured and thermal analysis, nuclear magnetic resonance and scanning electron microscopy studies were carried out. For some films the nanoparticles were surface-treated (STNP) while for others they were not (UNP). For concentrations of UNP greater than about 3.4 vol. %, ϵ' is much larger than expected on the basis of laws of mixing. On the other hand, ϵ' for materials made using STNP is well-behaved. Correspondingly, increased loss (ϵ" or tan δ) in the vicinity of room temperature is observed for the materials made from UNP. The anomalously large values of relative permittivity and increased loss are attributed to the presence of large aggregates in the materials made using the UNP. For both UNP-and STNP-based materials, the breakdown strength is found to decrease as nanoparticle concentration increases. The breakdown strength for the materials made using STNP is found to be larger for all concentrations than for those containing UNP despite the presence of large aggregates in some of the STNP-based materials. This shows that breakdown is strongly affected by the nanoparticle surfaces and/or the interface layer. It is also found that the breakdown strength for materials made using UNP increases as particle size increases. Finally, variable temperature and pressure proton nuclear magnetic resonance relaxation measurements were made to assess the effect of nanoparticle inclusion on polymer motion, and the effects were found to be very minor. [ABSTRACT FROM AUTHOR]

The relative permittivity has been measured at audio frequencies and low temperatures for nanocomposites composed of poly(ether imide) (PEI) and BaTiO3 nanoparticles, the nanoparticles in a cavity and polycrystalline BaTiO3. The data at room temperature, for the real part of the relative permittivity versus nanoparticle content of the heat-treated nanocomposites, are found to follow a recently proposed modified Hanai equation. Also, a low-temperature relaxation region (in the vicinity of 20 K) is found in the heat-treated nanocomposites. This relaxation region is also observed in measurements on the nanoparticles packed in a cavity and for the polycrystalline BaTiO3 materials. A relaxation associated with water in the PEI is observed in the as-prepared nanocomposites. Finally, the breakdown strength of the heat-treated nanocomposites is found to decrease as the nanoparticle content increases. Microstructure-level simulations of electric field statistics were carried out and show that matrix field intensification cannot account for all of the variation of breakdown strength with nanoparticle concentration. [ABSTRACT FROM AUTHOR]

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Background: Tauopathies are a group of age-related neurodegenerative diseases characterized by the accumulation of pathologically hyperphosphorylated tau protein in the brain, leading to prion-like aggregation and propagation. They include Alzheimer's disease (AD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and Pick's disease (PiD). Currently, reliable diagnostic biomarkers that directly reflect the capability of propagation and spreading of misfolded tau aggregates in peripheral tissues and body fluids are lacking., Methods: We utilized the seed-amplification assay (SAA) employing ultrasensitive real-time quaking-induced conversion (RT-QuIC) to assess the prion-like seeding activity of pathological tau in the skin of cadavers with neuropathologically confirmed tauopathies, including AD, PSP, CBD, and PiD, compared to normal controls., Results: We found that the skin tau-SAA demonstrated a significantly higher sensitivity (75-80%) and specificity (95-100%) for detecting tauopathy, depending on the tau substrates used. Moreover, the increased tau-seeding activity was also observed in biopsy skin samples from living AD and PSP patients examined. Analysis of the end products of skin-tau SAA confirmed that the increased seeding activity was accompanied by the formation of tau aggregates with different physicochemical properties related to two different tau substrates used., Conclusions: Overall, our study provides proof-of-concept that the skin tau-SAA can differentiate tauopathies from normal controls, suggesting that the seeding activity of misfolded tau in the skin could serve as a diagnostic biomarker for tauopathies., Competing Interests: Declarations. Ethics approval and consent to participate: All procedures and protocols were monitored and approved by the Institutional Review Boards (IRBs) of University Hospitals Cleveland Medical Center, Banner Sun Health Research Institute, and IRCCS Institute of Neurological Sciences of Bologna. Written informed consent was obtained from all living subjects undergoing skin biopsy or from family members for skin autopsy. For post-mortem sample collection, we obtained the specimens with respect to the wishes of the deceased and their family, following all legal and ethical guidelines. For skin biopsy procedures, all participants provided their informed consent prior to their inclusion in the study. Consent for publication: All participants in this study have provided written informed consent for their data and samples to be used in this research. Participants were also informed that the results of this study may be published and that all data would be fully anonymized to protect confidentiality. Competing interests: Authors declare that they have no competing interests., (© 2024. The Author(s).)

Background: Zoological gardens contain unique configurations of exotic and endemic animals and plants that create a diverse range of developing sites and potential sources of blood meals for local mosquitoes. This may imply unusual interspecific pathogen transmission risks involving zoo vertebrates, like avian malaria to captive penguins. Understanding mosquito ecology and host feeding patterns is necessary to improve mosquito control and disease prevention measures in these environments., Methods: Mosquito sampling took place in Chester Zoo for 3 years (2017, 2018, and 2019) and for 1 year in Flamingo Land (2017) using different trapping methods. Blood-fed mosquitoes were identified and their blood meal was amplified by PCR, sequenced, and blasted for host species identification., Results: In total, 640 blood-fed mosquitoes were collected [Culex pipiens (n = 497), Culiseta annulata (n = 81), Anopheles maculipennis s.l. (n = 7), An. claviger (n = 1), and unidentifiable (n = 55)]. Successful identification of the host species was achieved from 159 blood-fed mosquitoes. Mosquitoes fed on birds (n = 74), non-human mammals (n = 20), and humans (n = 71). There were mixed blood meals from two hosts (n = 6). The proportions of blood-fed mosquitoes varied across sampling seasons and sites within the zoos. The use of resting traps and aspiration of vegetation were more efficient techniques for capturing blood-fed mosquitoes than traps for host-seeking or gravid mosquitoes. By relating the locations of zoo vertebrates to where fed mosquitoes were trapped, the minimum travelling distances were calculated (13.7 to 366.7 m). Temperature, precipitation, relative humidity, proximity to zoo vertebrate exhibits, and vegetation level were found to be significantly associated with the proportion of captured blood-fed mosquitoes by generalized linear modelling., Conclusions: Mosquito feeding behaviour in zoos is mainly influenced by time, location (sampling area), temperature, and host availability, which highlights the value of mosquito monitoring in complex settings to plan control strategies and potentially reduce inherent disease transmission risks for humans and threatened zoo vertebrates.

The rapid adoption of Internet-accessible information resources by the clinical community, has resulted in an exponential growth in the variety and type of clinical information resources along with an increasing diversity of information technologies to deliver clinical information. To date, little formal work has been done to investigate the significance of new information technologies such as Internet-based digital libraries and multimedia record systems on clinical information need or information seeking behavior. In the work described in this paper, we highlight some results from our recent multimethod research design and investigation of the information-seeking behavior of Pittsburgh area medical oncologists to argue for the use of a multimethod research design as an essential component of any investigation of clinical information need and information-seeking behavior in the era of the digital medical library.

Special hospitals for children were first established in France at the beginning of the nineteenth century. The British delayed copying the French example for fifty years, in part because of the disquieting mortality caused by the spread of contagious diseases at the Enfants Malades in Paris. The privately managed British hospitals adopted varying tactics to minimize cross-infection on the wards. The smaller ones did not admit fever cases, while keeping one or two isolation cots handy for any infectious case arising on the wards. The larger hospitals cautiously admitted some children with infectious illness and attempted to provide complete isolation from the other in-patients. The management of the problems involved will be discussed in this paper. It will also be shown how the establishment of public fever hospitals, in the last quarter of the century, gradually relieved the voluntary paediatric hospitals of their responsibility for cases of notifiable disease. Finally, it will be argued that the British hospital system of coping with contagious illness served as a model for reform in France.