Gold-decorated magnetic nanoparticles design for hyperthermia applications and as a potential platform for their surface-functionalization

The integration of noble metal and magnetic nanoparticles with controlled structures that can couple various specific effects to the different nanocomposite in multifunctional nanosystems have been found interesting in the field of medicine. In this work, we show synthesis route to prepare small Au nanoparticles of sizes = 3.9 ± 0.2 nm attached to Fe 3 O 4 nanoparticle cores ( = 49.2 ± 3.5 nm) in aqueous medium for potential application as a nano-heater. Remarkably, the resulted Au decorated PEI-Fe 3 O 4 (Au@PEI-Fe 3 O 4 ) nanoparticles are able to retain bulk magnetic moment M S = 82–84 Am 2 /kg Fe3O4 , with the Verwey transition observed at T V = 98 K. In addition, the in vitro cytotoxicity analysis of the nanosystem microglial BV2 cells showed high viability (>97.5%) to concentrate up to 100 µg/mL in comparison to the control samples. In vitro heating experiments on microglial BV2 cells under an ac magnetic field (H 0 = 23.87 kA/m; f = 571 kHz) yielded specific power absorption (SPA) values of SPA = 43 ± 3 and 49 ± 1 μW/cell for PEI-Fe 3 O 4 and Au@PEI-Fe 3 O 4 NPs, respectively. These similar intracellular SPA values imply that functionalization of the magnetic particles with Au did not change the heating efficiency, providing at the same time a more flexible platform for multifunctional functionalization.Fil: León Félix, L.. Universidade do Brasília; Brasil. Universidad de Zaragoza; EspañaFil: Sanz, B.. Nb Nanoscale Biomagnetics S.l.; EspañaFil: Sebastián, V.. Universidad de Zaragoza; España. Centro de Investigación en Red en Bioingeniería; EspañaFil: Torres Molina, Teobaldo Enrique. Universidad de Zaragoza; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Sousa, Marcelo Henrique. Universidade do Brasília; BrasilFil: Coaquira, J. A. H.. Universidade do Brasília; BrasilFil: Ibarra, M.R.. Universidad de Zaragoza; EspañaFil: Goya, Gerardo Fabian. Universidad de Zaragoza; Españ

Dust in Supernovae and Supernova Remnants I : Formation Scenarios

Supernovae are considered as prime sources of dust in space. Observations of local supernovae over the past couple of decades have detected the presence of dust in supernova ejecta. The reddening of the high redshift quasars also indicate the presence of large masses of dust in early galaxies. Considering the top heavy IMF in the early galaxies, supernovae are assumed to be the major contributor to these large amounts of dust. However, the composition and morphology of dust grains formed in a supernova ejecta is yet to be understood with clarity. Moreover, the dust masses inferred from observations in mid-infrared and submillimeter wavelength regimes differ by two orders of magnitude or more. Therefore, the mechanism responsible for the synthesis of molecules and dust in such environments plays a crucial role in studying the evolution of cosmic dust in galaxies. This review summarises our current knowledge of dust formation in supernova ejecta and tries to quantify the role of supernovae as dust producers in a galaxy.Peer reviewe

Global Retinoblastoma Presentation and Analysis by National Income Level

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4) were female. Most patients (n = 3685 84.7%) were from low-and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 62.8%), followed by strabismus (n = 429 10.2%) and proptosis (n = 309 7.4%). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 95% CI, 12.94-24.80, and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 95% CI, 4.30-7.68). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs. © 2020 American Medical Association. All rights reserved

Changes in a peri-urban butterfly assemblage over 80 years near Melbourne, Australia

Although changes, particularly declines, in Australian terrestrial insects and other invertebrates have long been suspected and well-documented for some species, the magnitude, rate and spatial extent of decline remain unclear. Here we use a combination of alternative, qualitative approaches (expert opinion, historical records and temporal replication of surveys) to standardised monitoring and mapping programs to investigate the extent of change of a peri-urban butterfly assemblage. This assemblage, comprising 52 species, of which 46 are residents or seasonal immigrants, was studied at three spatial scales (local ~0.01 km2, intermediate ~9 km2 and regional ~100 km2) in the Eltham district near Melbourne based on presence/absence data over the past 40 (1981-2020) and 80 years (1941-2020). We then consider the causal factors or drivers that have led to changes, and we explore the timing and ecological patterns underpinning extirpations. Long-term records reveal substantial changes (mostly decline) in composition and species richness of the 46 breeding species at all spatial scales and time frames analysed. Although the magnitude and rate of decline were higher at the smaller, local to intermediate scales (29-43% decline over 40 years, loss rate of 0.20-0.25 species/year) compared with the larger, regional scale (26% decline over 80 years, loss rate of 0.15 species/year), extirpations at the larger scale were more alarming because they are indicative of widespread population collapse. Declines in relative abundance and occupancy were also recorded at the intermediate and regional spatial scales. Further decline (extinction debt) is anticipated for several ecological specialists currently known from very few sites. Historical extirpations mostly involved obligate myrmecophilous lycaenids and appear to have been largely driven by an interaction of urbanisation (habitat loss, degradation and fragmentation) and vegetation encroachment. More recent extirpations consist mainly of grass-feeding and mistletoe-feeding specialists and are more worrying because they have predominantly occurred within the past 20-30 years. An interaction of urbanisation (tree canopy death and decline of mistletoes and their host trees from ecosystem dysfunction) and climate change (water stress and heat waves) are considered to be the most likely drivers for these ecological guilds

Apolipoprotein-E genotype and Alzheimer's disease in a post mortem series

No abstract availabl

Cosmogenic nuclide moraine chronologies from Patagonia: A globally synchronic response of mountain glaciers during Termination 1?

Surface-exposure dating of moraines reveals that Patagonian glaciers fluctuated at the pulsebeat mimicked in polar ice cores from both hemispheres. These findings favor hypotheses that invoke coupled oceanic–atmospheric drivers to generate and propagate millennial-scale climate shifts during Termination 1.Fil: Soteres, Rodrigo L.. Universidad de Magallanes; ChileFil: Sagredo, Esteban. Pontificia Universidad Católica de Chile; Chile. Estación de Investigaciones Multidisciplinares Patagonia; ChileFil: Kaplan, M.R.. Columbia University; Estados UnidosFil: Martini, Mateo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Riquelme, Fabian. Pontificia Universidad Católica de Chile; ChileFil: Schaefer, J.M.. Columbia University; Estados Unido

Alzheimer's disease and apolipoprotein E genotype in Western Australia: An autopsy-verified series

OBJECTIVE: To determine the relationship between the apolipoprotein E epsilon 4 allele and autopsy-verified Alzheimer's disease (AD) in an Australian population. DESIGN: Retrospective case-control study. SETTING: Royal Perth Hospital, Perth, Western Australia (a tertiary referral hospital). SUBJECTS: 50 subjects with "definite" AD (according to the histological and clinical criteria of the Consortium to Establish a Registry for Alzheimer's Disease [CERAD]) and 30 control subjects who had died from a non-neurological disease were randomly selected from the hospital's neuropathology register. OUTCOME MEASURES: Histological grading of brain sections stained with the modified Bielschowsky stain according to the criteria of CERAD; number (burden) of neuritic plaques; apolipoprotein E genotype (APOE). RESULTS: Frequency of the epsilon 4 allele was significantly higher in the AD group (37%) than in the control group (2%) (chi 2 = 25.8; P < 0.00001). In the AD group, 50% of subjects were heterozygous for the epsilon 4 allele and 12% were homozygous, while in the control group one subject was heterozygous for the allele and none were homozygous. No association was seen between the epsilon 4 allele and neuritic plaque burden in the hippocampus, entorhinal cortex, middle frontal gyrus or inferior parietal lobule in subjects with AD. CONCLUSIONS: Our findings confirm an association between the epsilon 4 allele and autopsy-verified AD. The epsilon 4 allele may be an important risk factor for susceptibility to AD in the general Australian population

Genetic studies in a family with autosomal dominant rod and core disease

No abstract availabl