Local dielectric spectroscopy of near-surface glassy polymer dynamics

A non-contact scanning-probe-microscopy method was used to probe local near-surface dielectric susceptibility and dielectric relaxation in poly-vinyl-acetate (PVAc) near the glass transition. Dielectric spectra were measured from 10-4 Hz to 102 Hz as a function of temperature. The measurements probed a 20 nm thick layer below the free-surface of a bulk film. A small (4 K) reduction in glass transition temperature and moderate narrowing of the distribution of relaxation times was found. In contrast to results for ultra-thin-films confined on or between metallic electrodes, no reduction in the dielectric strength was found, inconsistent with the immobilization of slower modes.Comment: submitte

Preliminary research of recombinant matrix extracellular phosphoglycoprotein (MEPE) mineralization ability in vitro

The matrix extracellular phosphoglycoprotein (MEPE) gene is highly expressed in tumors that cause oncogenic hypophosphatemic osteomalacia (OHO). MEPE is also known as one of the bone-tooth matrix proteins and is associated with bone and teeth mineralization. We developed a rabbit polyclonal antibody directed against recombinant human MEPE after cloning its cDNA from the cDNA library of a human brain cDNA library. Using this anti-body, we analyzed the distribution of MEPE in dog dental germ tissue by immunohistochemistry. In these specimens, MEPE was predominantly expressed by odontoblast cells and predentin, but not by dental pulp cells. Furthermore, we used von kossa staining and the results suggested that, MEPE could induce mineralization and we propose that this protein had a potential effect on dental rehabilitation.Key words: Matrix extracellular phosphoglycoprotein (MEPE), mineralization Von kossa

Comparison of Circumferential and Traditional Trabeculotomy in Pediatric Glaucoma

Purpose To compare intraocular pressure (IOP) control of pediatric glaucoma patients undergoing traditional trabeculotomy (<360 degrees or partial) with those receiving 360-degree circumferential trabeculotomy. Methods The medical records of pediatric glaucoma patients receiving trabeculotomy at a single institution from 2000 to 2012were retrospectively reviewed. Patients were divided into two groups: a traditional trabeculotomy group and 360-degree trabeculotomy group. IOP at baseline and at 1, 3, 6, and 12 months’ follow-up were compared within and each groups. Results A total of 77 eyes of 56 patients (age at surgery, 1.52 ± 2.68 years) in the traditional group and 14 eyes of 10 patients in the 360-degree group (age at surgery, 0.61 ± 0.42 years) were included. Mean baseline IOP was similar in both groups (traditional, 28.75 ± 8.80 mm Hg; 360-degree, 30.35 ± 6.04 mm Hg; t test; P = 0.43). Mean 1-year IOP was 17.05 ± 5.92 mm Hg in the traditional group and 11.0 ± 2.31 mm Hg in the 360-degree group. At 1-year, the surgical success rate was 58.44% in the traditional group and 85.71% in the 360-degree group; 32 eyes in the former and 2 eyes in the latter required another glaucoma procedure within 1 year for IOP control. For both groups, compared to baseline values, IOP decreased significantly with all postoperative measurements (paired t test, all P < 0.01). The 360-degree group had significantly lower IOP compared to the traditional group at 1-year (t test, P < 0.01). Conclusions Both 360-degree and traditional trabeculotomy significantly reduced IOP in children through 1 year’s follow-up, although the former procedure shows better 1-year postoperative IOP control, with higher rate of surgical success

Cognitive and brain cytokine profile of non-demented individuals with cerebral amyloid-beta deposition

Brain inflammation has been increasingly associated with early amyloid accumulation in Alzheimer's disease models; however, evidence of its occurrence in humans remains scarce. To elucidate whether amyloid deposition is associated with neuroinflammation and cognitive deficits, we studied brain inflammatory cytokine expression and cognitive decline in non-demented elderly individuals with and without cerebral amyloid-beta deposition. Global cognition, episodic, working, and semantic memory, perceptual speed, visuospatial ability, and longitudinal decline (5.7 ± 3.6 years) in each cognitive domain were compared between elderly individuals (66-79 years) with and without cerebral amyloid-beta deposition. The expression of 20 inflammatory cytokines was analyzed in frozen temporal, parietal, and frontal cortices and compared between older individuals with and without amyloid-beta deposition in each brain region. Correlation analyses were performed to analyze associations between amyloid-beta load, cytokine expression, and cognitive decline. Individuals with cortical amyloid-beta deposition displayed deficits and a faster rate of cognitive decline in perceptual speed as compared with those individuals without amyloid-beta. This decline was positively associated with cortical amyloid-beta levels. Elderly individuals with amyloid-beta deposition had higher levels of IL-1β, IL-6, and eotaxin-3 in the temporal cortex accompanied by an increase in MCP-1 and IL-1β in the parietal cortex and a trend towards higher levels of IL-1β and MCP-1 in the frontal cortex as compared with age-matched amyloid-free individuals. Brain IL-1β levels displayed a positive association with cortical amyloid burden in each brain region. Finally, differential cytokine expression in each cortical region was associated with cognitive decline. Elderly individuals with amyloid-beta neuropathology but no symptomatic manifestation of dementia, exhibit cognitive decline and increased brain cytokine expression. Such observations suggest that increased cytokine expression might be an early event in the Alzheimer's continuum. The online version contains supplementary material available at 10.1186/s12974-021-02169-0

Derivation of hypermethylated pluripotent embryonic stem cells with high potency.

Naive hypomethylated embryonic pluripotent stem cells (ESCs) are developmentally closest to the preimplantation epiblast of blastocysts, with the potential to contribute to all embryonic tissues and the germline, excepting the extra-embryonic tissues in chimeric embryos. By contrast, epiblast stem cells (EpiSCs) resembling postimplantation epiblast are relatively more methylated and show a limited potential for chimerism. Here, for the first time, we reveal advanced pluripotent stem cells (ASCs), which are developmentally beyond the pluripotent cells in the inner cell mass but with higher potency than EpiSCs. Accordingly, a single ASC contributes very efficiently to the fetus, germline, yolk sac and the placental labyrinth in chimeras. Since they are developmentally more advanced, ASCs do not contribute to the trophoblast. ASCs were derived from blastocysts in two steps in a chemically defined medium supplemented with Activin A and basic fibroblast growth factor, followed by culturing in ABCL medium containing ActA, BMP4, CHIR99021 and leukemia inhibitory factor. Notably, ASCs exhibit a distinct transcriptome with the expression of both naive pluripotency genes, as well as mesodermal somatic genes; Eomes, Eras, Tdgf1, Evx1, hand1, Wnt5a and distinct repetitive elements. Conversion of established ESCs to ASCs is also achievable. Importantly, ASCs exhibit a stable hypermethylated epigenome and mostly intact imprints as compared to the hypomethylated inner cell mass of blastocysts and naive ESCs. Properties of ASCs suggest that they represent cells at an intermediate cellular state between the naive and primed states of pluripotency.This work was supported by grants from the Ministry of Science and Technology project of Inner Mongolia (N0. 20130216), the National Natural Science Foundation of China (No.31560335) and by Wellcome Trust Investigator Award to MAS, and by a core grant from the Wellcome Trust and CRUK to the Gurdon Institute

A pilot randomized clinical trial of intermittent occlusion therapy liquid crystal glasses versus traditional patching for treatment of moderate unilateral amblyopia

PURPOSE: To compare the effectiveness of intermittent occlusion therapy (IO therapy) using liquid crystal glasses and continuous occlusion therapy using traditional adhesive patches for treating amblyopia. METHODS: Children 3-8 years of age with previously untreated, moderate, unilateral amblyopia (visual acuity of 20/40 to 20/100 in the amblyopic eye) were enrolled in this randomized controlled trial. Amblyopia was associated with strabismus, anisometropia, or both. All subjects had worn any optimal refractive correction for at least 12 weeks without improvement. Subjects were randomized into two treatment groups: a 4-hour IO therapy group with liquid crystal glasses (Amblyz), set at 30-second opaque/transparent intervals (occluded 50% of wear time), and a 2-hour continuous patching group (occluded 100% of wear time). For each patient, visual acuity was measured using ATS-HOTV before and after 12 weeks of treatment. RESULTS: Data from 34 patients were available for analysis. Amblyopic eye visual acuity improvement from baseline was 0.15 ± 0.12 logMAR (95% CI, 0.09-0.15) in the IO therapy group (n = 19) and 0.15 ± 0.11 logMAR (95% CI, 0.1-0.15) in the patching group (n = 15). In both groups improvement was significant, but the difference between groups was not (P = 0.73). No adverse effects were reported. CONCLUSIONS: In this pilot study, IO therapy with liquid crystal glasses is not inferior to adhesive patching and is a promising alternative treatment for children 3-8 years of age with moderate amblyopia

Heteroepitaxy of La2O3La_2O_3 and La2−xYxO3La_{2-x}Y_xO_3 on GaAs (111)A by Atomic Layer Deposition: Achieving Low Interface Trap Density

GaAs metal–oxide–semiconductor devices historically suffer from Fermi-level pinning, which is mainly due to the high trap density of states at the oxide/GaAs interface. In this work, we present a new way of passivating the interface trap states by growing an epitaxial layer of high-k dielectric oxide, $La_{2–x}Y_xO_3$, on GaAs(111)A. High-quality epitaxial $La_{2–x}Y_xO_3$ thin films are achieved by an ex situ atomic layer deposition (ALD) process, and GaAs MOS capacitors made from this epitaxial structure show very good interface quality with small frequency dispersion and low interface trap densities $(D_{it})$. In particular, the $La_2O_3$/GaAs interface, which has a lattice mismatch of only 0.04%, shows very low $D_{it}$ in the GaAs bandgap, below $3 × 10^{11} cm^{–2} eV^{–1}$ near the conduction band edge. The $La_2O_3$/GaAs capacitors also show the lowest frequency dispersion of any dielectric on GaAs. This is the first achievement of such low trap densities for oxides on GaAs.Chemistry and Chemical Biolog

Genome-wide meta-analysis of muscle weakness identifies 15 susceptibility loci in older men and women

© 2021, The Author(s). Low muscle strength is an important heritable indicator of poor health linked to morbidity and mortality in older people. In a genome-wide association study meta-analysis of 256, 523 Europeans aged 60 years and over from 22 cohorts we identify 15 loci associated with muscle weakness (European Working Group on Sarcopenia in Older People definition: n = 48,596 cases, 18.9% of total), including 12 loci not implicated in previous analyses of continuous measures of grip strength. Loci include genes reportedly involved in autoimmune disease (HLA-DQA1p = 4 × 10−17), arthritis (GDF5p = 4 × 10−13), cell cycle control and cancer protection, regulation of transcription, and others involved in the development and maintenance of the musculoskeletal system. Using Mendelian randomization we report possible overlapping causal pathways, including diabetes susceptibility, haematological parameters, and the immune system. We conclude that muscle weakness in older adults has distinct mechanisms from continuous strength, including several pathways considered to be hallmarks of ageing