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Effectiveness of experimental composites containing antimicrobial agents for orthodontic applications
Full text linkThis study evaluated the effectiveness of experimental composites containing antimicrobial agents such as nisin (N) and stannous fluoride (SnF2) against S. mutans, for orthodontic applications. First, the antimicrobial agents were added at varying concentrations (%) into a base material consisting of methacrylate monomers and inorganic particles, forming the groups: control (C), N4% (N4), N7% (N7), N10% (N10), SnF20.6% (SnF20.6), SnF21.5% (SnF21.5), SnF2 3% (SnF23), and N4% + SnF2 0. 6% (N4SnF20.6). The degree of conversion (DC%) and colony-forming units (CFU) were evaluated. Brackets were bonded onto the enamel of bovine incisors using these composites, and the enamel hardness was measured at distances of 500, 550, and 600 µm from the bracket, before and after the cariogenic challenge. The shear bond strength was also investigated, and the composite remnant on the enamel was assessed using the ARI score. Data were analyzed using analysis of variance and Tukey’s test (α = 0.05). Of all the groups, only N10 led to lower DC% (p < 0.05). CFU was significantly reduced for all groups when compared to C (p < 0.05), with SnF2 showing the highest inhibition for all concentrations. After the cariogenic challenge, for all distances from the brackets, the decrease in hardness was lower for all experimental composites than for C (p < 0.05). SBS was lower only for the N4SnF20.6 when compared to C. Adhesive failure was more frequent, with the composite remnant covering less than 50% of the adhesive area. In conclusion, adding those antimicrobial agents effectively inhibited S. mutans and protected enamel around brackets without compromising most mechanical properties. However, the highest nisin concentration (10%) adversely affected the degree of conversion, and the combination of nisin and stannous fluoride reduced bond strength
Reflectance Measurements of 3.5-THz Black Coatings Using Terahertz Quantum Cascade Laser Self-Mixing Interferometry
No full textBlackbody on-board calibration targets are key components of spaceborne terahertz radiometers. These must have an emissivity close to 1, uniform temperature, and very low reflectivity. The latter property can be achieved by applying a THz absorbing coating to a surface with a complex reflection geometry. However, the properties of microwave-absorbing media are poorly characterized in the 0.5–5.0 THz. Here, we use a long-path 3.5-THz quantum-cascade laser self-mixing interferometry technique to measure the reflectance of a range of black coatings. Surrey Nanosystems Vantablack S-VIS and N-Science Deep Space Black coatings provide the highest return losses with 28.5 dB and 27.6 dB respectively
Influence of film formation kinetics on the dispersion of colloidal quantum dots in organic small molecule matrices
Full text linkImproving the dispersion of colloidal quantum dots (QDs) within organic semiconductor (OSC) matrices remains critical for advancing hybrid nanocomposite optoelectronic technologies. This study investigates how film-deposition kinetics influence the morphology of TIPS-tetracene (TIPS-Tc):PbS QD blends, comparing spin-coating and blade coating for QDs ligated with either native oleic acid (OA) or a matched carboxylic acid functionalised tetracene analogue (TET-CA). Films spun-cast at low spin speeds form highly crystalline TIPS-Tc domains with highly aggregated QDs. Increased spin speed induces a deeper solvent quench, driving rapid TIPS-Tc nucleation while kinetically arresting QD diffusion, which improves QD dispersion within the crystalline matrix. TIPS-Tc:PbS-OA blends typically exhibit poor QD dispersibility due to poor matching between the OA ligands and the TIPS-Tc matrix. This work demonstrates that through employing high spin speeds QD dispersibilities may be significantly enhanced, even for PbS-OA, a significant step demonstrating that QD-OSC surface chemistries may not have to be fully matched to attain desired, well-dispersed morphologies. In contrast, blade-coating proceeds under slower solvent removal, resulting in weakly crystalline TIPS-Tc and extensive QD aggregation due to extended diffusion and delayed nucleation. These findings reveal the critical role of processing kinetics in directing OSC-QD self-assembly, essential for the optimisation of nanocomposite morphologies for next-generation optoelectronic devices
Palaeoglacier reconstruction and dynamics of Cordillera Vilcanota in the tropical high Peruvian Andes
Full text linkTropical glaciers are important indicators of climate change, provide freshwater resources for downstream communities, and form an important component of the hydrological cycle. Understanding the dynamics and patterns of behaviour of tropical palaeoglaciers is important for interpreting their sensitivities and vulnerabilities. Glacier advances in the high tropical Peruvian Andes occurred multiple times during the last glacial cycle and Holocene, leaving complex geomorphological evidence on the landscape. The substantial topographic, geological and climatic variability in this region leads to high geomorphic diversity. However, few detailed geomorphological studies have been conducted to date, leading to considerable uncertainty in the behaviours and drivers of tropical palaeoglaciers. Here, we provide a detailed geomorphological analysis of the Cordillera Vilcanota, Cusco region, southern Peru (71°W, 13.7°S), and use morphostratigraphic principles to reconstruct the former maximum icefield extent and palaeoglacier advances. Across this domain, we mapped ~23,000 features encompassing five key environments: glacier, subglacial, ice-marginal, fluvial and lacustrine. The mapped features show evidence of both modern-day polythermal and temperate ice margins, with low meltwater volumes leading to small-scale glaciofluvial landform formation. However, larger moraines, beyond those well-dated to the Younger Dryas and Antarctic Cold Reversal, assumed to represent Last Glacial Maximum and earlier advances, suggest that conditions were temperate and drained by more substantial rivers, with coupled flow of ice and till, and evidence of subglacial scouring, drumlin formation and the deposition of substantial moraines and large palaeosandar. Our reconstructed maximum icefield covers 2,660 km2 and was drained by multiple topographically constrained ice lobes across the region. In the north, these ice lobes reached an elevation of 3,500 m asl, but were limited to above 4,500 m asl in the south, likely reflecting the dominant moisture sources. Our geomorphological mapping reveals seven clear ice margins, morphostratigraphically correlated across the study region, reflecting at least seven palaeoglacier advances during the last glacial cycle, including the Late Glacial period and the Holocene
Temporal uncertainty, spatial stressors and disrupted connections: temporary accommodation and family life, health and wellbeing
Full text linkThe growing unaffordability of housing in many high-income countries is pushing more people into temporary living situations. While housing is a recognised social determinant of health, less is known about the impact of housing insecurity and ‘hidden homelessness’, where families are not living on the street, but face repeated moves or protracted periods in temporary accommodation. This paper explores, from the perspective of parents and children, the impact of living in temporary accommodation on families’ health and wellbeing. We undertook 38 interviews with parents and children across three geographical areas in England: South Yorkshire, the North West and London. Families were living (or had lived) in various forms of temporary accommodation including hotels, hostels, and bed and breakfast accommodation. Interviews took place in person, over the phone and online via video call. We utilised framework analysis to analyse our data. Our analysis generated key themes focusing on: (i) the constant, cumulative stress associated with not knowing if, when and where stable accommodation might be secured, (ii) the spatial unsuitability of temporary accommodation for family life and (iii) the disconnection and disruption to social support, education and employment for families living in temporary accommodation. This paper is the first to mobilise slow violence within a social determinants framework in understanding the multiple interacting ways in which temporary accommodation impacts on the health and wellbeing of families
Ancient DNA reconstruction of late holocene ecosystems within the Carpathian basin from paleo-meanders and archaeological deposits
Full text linkThe diverse ecology in the Carpathian Basin supported a variety of subsistence strategies throughout the Holocene, ranging from animal husbandry to the management of woodlands, grasslands, and wetlands. The earliest evidence of aquatic resource use in the region dates back to the Early Neolithic (~ 6200−5300 cal BC), with cultural practices extending into recent times. This is reflected in the numerous open-air archaeological sites widely distributed across the landscape and on the Danube meanders. However, the archaeological record, especially organic remains and fossils, may not fully capture the region’s species diversity due to degradation and scarcity, hindering the accurate reconstruction of past human-environment interactions. Recent studies have shown that ancient DNA in sediments (sedaDNA) can survive even in the absence of visible fossils, however, these studies have primarily been limited to cave-, lake- and permanently frozen sedimentary deposits. Here, we investigate two open-air archaeological sites and three paleo meander deposits of the Danube in Serbia (southeastern Europe) using sedaDNA. Our analysis reveals genetic traces from past freshwater and terrestrial ecosystems and local exploitation of the migratory sturgeon species, currently extirpated from the region. We find sedaDNA preserved in sediments from unsheltered archaeological contexts and explore the associated challenges that require further investigation
Temperature dependance of the photogalvanic effect in Bi2Se3 at milli-Kelvin Temperatures
Full text linkThe photogalvanic effect can probe the surface states of topological insulators. At optical photon energies surface states near the Dirac point are excited into bulk bands, whereas at energies commensurate with THz excitation, surface states are excited within the Dirac cone leading to a potential enhancement in sensitivity to topological surface states (TSS) and Berry phase. Here, we demonstrate measurements of the circular photogalvanic effect (CPGE) in the topological insulator Bi2Se3 with both optical and THz frequencies at room temperature. Furthermore, we also probe this effect at millikelvin temperatures with THz light. We find the CPGE increases rapidly below 2 K, and is potentially correlated with the weak antilocalization, which itself is dependent on phase coherence lengths. This work lays the foundation for studying both TI and TSS using CPGE at ultra-low temperatures
“A safe, responsible, and profitable ecosystem of music”: Analyzing perceptions and implementation of generative AI in the music industry
Full text linkThis article analyzes music industry discourses about generative AI to understand competing and conflicting views across the industrial field. Our analysis mobilizes primary data from ethnographic fieldwork collected at music trade conferences between 2023 and 2024 and secondary data from trade press, corporate statements, reports published by governments, unions, and trade bodies. Our analysis illuminates tensions and contradictions among protectionist, liberalizing, and conciliatory views toward generative AI. Some corporate actors and public stakeholders advocate for protectionist business policies and “responsible” AI development that foregrounds potential harms of AI. Other corporate actors offer more liberalizing views, encouraging investment, experimentation, and adoption of generative AI systems to cut costs and increase profits. We also note conciliatory positions, mainly from musicians’ unions and trade bodies, trying to find compromises between these two poles. We argue that these contradictions reveal a fundamentally misunderstood notion of universal AI ethics in the music industry
Ideal efficacy photoswitching for chromocontrol of TRPC4/5 channel functions in live tissues
Full text linkPrecisely probing the endogenous roles of target proteins is crucial for biological research. Photochemical tools can be photoactuated with high spatiotemporal resolution but often they are unreliable in vivo because spatiotemporal variations of reagent concentration result in inhomogeneous bioactivity. We now describe ideal efficacy photoswitching, a paradigm that internally compensates for reagent concentration by self-competitive binding, allowing purely wavelength-dependent chromocontrol over bioactivity that is consistent from cell culture to deep tissues. We demonstrate this with photoswitches for endogenous transient receptor potential (TRP) C4 and C5 ion channels, reproducibly delivering strong agonism under 360-nm illumination, weak agonism under 385-nm illumination and strong antagonism under 440-nm illumination. These ligands unlock a range of high-precision investigations in TRP biology, from neuronal activity to exocytosis, reproductive signaling and smooth muscle contractility. The ideal efficacy photoswitching paradigm should also unlock high-performance chromocontrol over a wide range of sensory or signaling channels and receptors even in vivo
Large reaching datasets quantify the impact of age, sex/gender, and experience on motor control
Full text linkAs we age, our movements become slower and less precise—but the extent of this decline remains unclear. To address this, we harmonized data from 2390 participants across four published studies using a standard center-out reaching task. We found that older age was associated with a steady decline in reaction time (–1.3 ms/year), movement time (–4.3 ms/year), and movement precision (–0.04°/year). Although the rate of decline did not differ by sex/gender, females consistently reacted more slowly (–6.4 ms), moved more slowly (–44.6 ms), and exhibited greater precision ( + 0.6°) across the adult lifespan. Using the dataset that included experiential measures, we found that sex/gender differences were markedly reduced once factors, such as video game use, daily computer usage, and daily sleep, were taken into account, whereas age remained a consistent predictor of motor decline. Together, these findings provide a large-scale examination of age, sex/gender, and experiential effects on motor control, offering a normative benchmark to inform future clinical interventions aimed at preserving motor function across the lifespan
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