1,251 research outputs found

    A versatile dual spot laser scanning confocal microscopy system for advanced fluorescence correlation spectroscopy analysis in living cell

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    A fluorescence correlation spectroscopy (FCS) system based on two independent measurement volumes is presented. The optical setup and data acquisition hardware are detailed, as well as a complete protocol to control the location, size and shape of the measurement volumes. A method that allows to monitor independently the excitation and collection efficiency distribution is proposed. Finally, a few examples of measurements that exploit the two spots in static and/or scanning schemes, are reported.Comment: Accepted for publication in Review of Scientific Instrumen

    Ethyl Glucuronide in Scalp and Non-head Hair: An Intra-individual Comparison

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    Aims: Analysis of ethyl glucuronide (EtG), a minor metabolite of ethanol, is a valid tool for the assessment of social and chronic excessive alcohol consumption. Standardized analysis of EtG is usually done in head hair. As head hair cannot always be provided, alternative hair matrices become more and more interesting. Therefore, a study was performed that compared the intra-individual EtG concentrations in scalp hair and non-head hair (chest, arm, leg and axillary hair). Methods: Hair samples were collected from 68 subjects undergoing an expert assessment for fitness to drive. Aqueous extracts of the hair matrix were cleaned by solid-phase extraction, using an Oasis MAX column. EtG was first derivatized with perfluoropentanoic anhydride and then quantified by GC-MS/MS in negative chemical ionization mode, using EtG-d5 as internal standard. Results: For categorizing drinking behaviour, the two EtG cut-off values recommended by the Society of Hair Testing were applied for all different hair types. For chest, arm and leg hair, correct classification ratios were >83%. This corresponds to sensitivity values >78% and specificities >75%. Such values indicate together with φ coefficients (rφ) > 0.7 a high correlation of the categorization of the drinking behaviour based on these body hair EtG concentrations compared with the indexing based on scalp hair EtG-values. However, it must be taken into consideration that the time frame represented by non-head hair may extend way back. Conclusions: These results indicate that chest, arm and leg hair can be a valid alternative to assess the drinking behaviour of a subject if head hair is not available; whereas axillary hair is not suitable as alternative matri

    Dihydrotestostenone increase the gene expression of androgen receptor coregulator FHL2 in human nontransformed epithelial prostatic cells

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    The actions of androgens are mediated through an androgen receptor (AR), and AR activity is modulated by coregulators. The aim of this study was to assess the action of androgens in the expression of AR and the coregulators FHL-2 and SHP-1 in human non-transformed epithelial prostatic cells (HNTEP) treated with androgens. Prostate tissues were obtained from 12 patients between 60 and 77 years of age. HNTEP cells were grown in basal medium and treated with DHT in different conditions. HNTEP cells under treatment with DHT (10-13 M) induced an increase in FHL-2 expression. In turn, high DHT concentrations (10-8 M) induced an increase in the expression SHP-1. The present data suggest that the SHP-1 and FHL-2 genes play a role in the control of responsiveness and androgen-dose-dependent cell proliferation in HNTEP cells. Further studies are needed to assess the influence of androgens in AR and its coregulators and the implications in the pathophysiology of prostate diseases.Key words: Androgens, FHL-2, AR, prostate, proliferation, coregulators

    Eliminating the Racial Disparity in Classroom Exclusionary Discipline

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    Advocates call for schools with high suspension rates to receive technical assistance in adopting “proven-effective” systematic supports. Such supports include teacher professional development. This call is justified given evidence that good teaching matters. But what types of professional development should be funded? Increasingly, research points to the promise of programs that are sustained, rigorous, and focused on teachers’ interactions with students. The current study tests whether a professional development program with these three characteristics helped change teachers’ use of exclusionary discipline practices—especially with their African American students. Exclusionary discipline is when a classroom teacher sends a student to the administrators’ office for perceived misbehavior. Administrators then typically assign a consequence, usually in the form of suspension (in-school or out-of school). The My Teaching Partner-Secondary (MTP-S) aims to improve teachers’ interactions with their students when implementing instruction and managing behavior. MTP-S helps teachers offer clear routines, implement consistent rules, and monitor behavior in a proactive way. The program also supports teachers in developing warm, respectful relationships that recognize students’ needs for autonomy and leadership. Teachers are paired with a coach for an entire school year (sustained approach), they regularly reflect on videorecordings of their classroom instruction and carefully observe how they interact with students, and they apply the validated Classroom Assessment Scoring System (CLASS-S) to improve the quality of their interactions (rigorous approach). In the current study, a randomized controlled trial found that teachers receiving MTP-S relied less on exclusionary discipline compared to the control teachers. Specifically, MTP-S teachers issued fewer exclusionary discipline referrals to their African American students. This is the first study to show that programs like MTP-S that focus on teacher-student interactions in a sustained manner using a rigorous approach can actually reduce the disproportionate use of exclusionary discipline with African American students. More broadly, the findings offer policymakers direction in identifying types of professional development programs that have promise for reducing the racial discipline gap

    Repurposing Face Masks after Use: From Wastes to Anode Materials for Na-Ion Batteries

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    Nowadays, face masks play an essential role in limiting coronavirus diffusion. However, their disposable nature represents a relevant environmental issue. In this work, we propose the utilization of two types of disposed (waste) face masks to prepare hard carbons (biochar) by pyrolytic conversion in mild conditions. Moreover, we evaluated the application of the produced hard carbons as anode materials in Na-ion batteries. Pristine face masks were firstly analyzed through infrared spectroscopy and thermogravimetric analysis. The pyrolysis of both mask types resulted in highly disordered carbons, as revealed by field-emission scanning electron microscopy and Raman spectroscopy, with a very low specific surface area. Anodes prepared with these carbons were tested in laboratory-scale Na-metal cells through electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic cycling, displaying an acceptable specific capacity along a wide range of current regimes, with a good coulombic efficiency (>98% over at least 750 cycles). As a proof of concept, the anodes were also used to assemble a Na-ion cell in combination with a Na3V2(PO4)(2)F-3 (NVPF) cathode and tested towards galvanostatic cycling, with an initial capacity of almost 120 mAhg(-1) (decreasing at about 47 mAhg(-1) after 50 cycles). Even though further optimization is required for a real application, the achieved electrochemical performances represent a preliminary confirmation of the possibility of repurposing disposable face masks into higher-value materials for Na-ion batteries

    Autism and the U.K. secondary school experience

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    This research investigated the self-reported mainstream school experiences of those diagnosed on the autistic spectrum compared with the typically developing school population. Existing literature identifies four key areas that affect the quality of the school experience for students with autism: social skills, perceived relationships with teaching staff, general school functioning, and interpersonal strengths of the young person. These areas were explored in a mainstream U.K. secondary school with 14 students with autism and 14 age and gender matched students without autism, using self-report questionnaires and semi-structured interviews. Quantitative analyses showed consistent school experiences for both groups, although content analysis of interview data highlighted some differences in the ways in which the groups perceive group work, peers, and teaching staff within school. Implications for school inclusion are discussed, drawing attention to how staff awareness of autism could improve school experience and success for students with autism attending mainstream schools

    Cumulative Experience of Educational Assets from Preschool through First Grade and the Social-emotional Well-being of English- and Spanish-Speaking Children

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    Children’s social and emotional experiences influence brain development and are therefore central to outcomes of behavior, learning, and health. The current study examined associations between children’s cumulative educational assets in the early grades and end of first grade social-emotional outcomes for children from English- and Spanish-speaking families. Data were drawn from a sample of preschool-aged children (N = 1,132) from low-income families in a large, culturally, and linguistically diverse sample followed annually from pre-kindergarten through first grade. A multi-method, multi-informant approach was used to assess predictor and outcome variables. Results indicate overall that cumulative experiences of educational assets (teacher-student interaction and relationships, parent-teacher communication) were associated with indicators of children’s social-emotional well-being and matter in similar ways for children from English- and Spanish-speaking families. However, we did find some evidence of significant interactions of Spanish as a home language with cumulative educational assets on children’s conduct problems and feelings about peers

    Direct imaging of photonic nanojets

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    International audienceWe report the direct experimental observation of photonic nanojets created by single latex microspheres illuminated by a plane wave at a wavelength of 520 nm. Measurements are performed with a fast scanning confocal microscope in detection mode, where the detection pinhole defines a diffraction-limited observation volume that is scanned in three dimensions over the microsphere vicinity. From the collected stack of images, we reconstruct the full 3 dimensional photonic nanojet beam. Observations are conducted forpolystyrene spheres of 1, 3 and 5 mum diameter deposited on a glass substrate, the upper medium being air or water. Experimental results are compared to calculations performed using the Mie theory. We measure nanojet sizes as small as 270 nm FWHM for a 3 mum sphere at a wavelength lambda of 520 nm. The beam keeps a subwavelength FWHM over a propagation distance of more than 3 lambda, displaying all the specificities of a photonic nanojet

    Peripheral neuropathy: An important contributor to physical limitation and morbidity in stages 3 and 4 chronic kidney disease

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    Background: Impaired physical function drives adverse outcomes in chronic kidney disease (CKD). Peripheral neuropathy is highly prevalent in CKD, though its contribution to physical function in CKD patients is unknown. This study examined the relationships between peripheral neuropathy, walking speed and quality of life (QoL) in stages 3 and 4 CKD. Methods: This was a prospective observational study investigating neuropathy in CKD patients with an estimated glomerular filtration rate (eGFR) 15-60 mL/min/1.73 m2. A total of 109 patients were consecutively recruited. The presence and severity of peripheral neuropathy was determined using the total neuropathy score. Walking speed was assessed at both usual and maximal speed, and QoL was assessed using the Short- Form 36 (SF-36) questionnaire. Results: Peripheral neuropathy was highly prevalent: 40% demonstrated mild neuropathy and 37% had moderate-severe neuropathy. Increasing neuropathy severity was the primary predictor of reduced walking speed (R2 = -0.41, P < 0.001) and remained so after multivariable analysis adjustment for diabetes. This association was evident for both usual and maximal walking speeds. Neuropathy correlated significantly with low scores on multiple domains of SF-36 including physical function (r = -0.570, P < 0.001). Subanalysis according to diabetic status revealed a high prevalence of neuropathy both with and without diabetes; relationships to walking speed remained evident in subgroup analysis. However, those with diabetes demonstrated greater severity of neuropathy, slower walking speed and lower scores in QoL. Conclusions: Moderate to severe peripheral neuropathy was common in stages 3 and 4 CKD, associated with reduced walking speed independent of diabetes status and was correlated with patient-reported QoL. This suggests that neuropathy is an important contributor to declining physical function in CKD irrespective of diabetes status. Targeted diagnosis and management of peripheral neuropathy during CKD progression may improve functional outcomes and QoL
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