RESUMO
The inter-plane crosstalk and limited axial resolution are two key points that hinder the performance of three-dimensional (3D) holograms. The state-of-the-art methods rely on increasing the orthogonality of the cross-sections of a 3D object at different depths to lower the impact of inter-plane crosstalk. Such strategy either produces unidirectional 3D hologram or induces speckle noise. Recently, learning-based methods provide a new way to solve this problem. However, most related works rely on convolution neural networks and the reconstructed 3D holograms have limited axial resolution and display quality. In this work, we propose a vision transformer (ViT) empowered physics-driven deep neural network which can realize the generation of omnidirectional 3D holograms. Owing to the global attention mechanism of ViT, our 3D CGH has small inter-plane crosstalk and high axial resolution. We believe our work not only promotes high-quality 3D holographic display, but also opens a new avenue for complex inverse design in photonics.
RESUMO
A humidity sensor based on an optical fiber Mach-Zehnder interferometer (MZI) coated with a GO/MoS2@PVA composite membrane was investigated for non-contact sensing. MoS2 was used as a nanospacer to enhance the humidity-sensitive properties of GO, and the adhesion and stability of the composite membrane on the fiber surface could be increased by PVA. The proposed sensor shows a maximum sensitivity of 0.26â dB/%RH with average response and recovery times of 1.62 and 1.11â s, respectively. In non-contact sensing applications, the sensor can effectively recognize a maximum distance of 10â mm for the proximity of a human finger with a distance variation interval of 3â mm. The proposed sensor is expected to be applied in non-contact distance detection and localization or as a non-contact human-computer interaction panel.
RESUMO
The isothermal melting behaviors of ultra-high molecular weight polyethylene (UHMWPE) with different entangled states (i.e., nascent and melt-crystallized samples) are studied. For two kinds of UHMWPE samples, the result shows that the relative content of survived crystals (Xs) exponentially decreases with time and reaches a constant value. It is suggested that such a melting behavior is related to the observed nonlinear growth of crystals induced by the kinetically rejected entanglements accumulated at the growth front. Additionally, the exponential decay of Xs with time provides a characteristic melting time (τ) for the melting process. Compared to the melt-crystallized UHMWPE, the τ value of nascent UHMWPE is generally longer even in a higher temperature range, which is mainly because the former has a larger entanglement density difference. Furthermore, these observations demonstrate that UHMWPEs with different entangled states have an analogous melting mechanism since they exhibit a similar melting activation energy (≈1300 kJ mol-1).
Assuntos
Cristalização , Polietilenos , Cinética , Polietilenos/química , Temperatura de Transição , TemperaturaRESUMO
A degradable biopolymer is an effective radiative cooling material.
Assuntos
DNA , Gelatina , Gelatina/química , DNA/química , Géis/química , Temperatura BaixaRESUMO
Passive radiative cooling (PRC) that realizes thermal management without consuming any energy has attracted increasing attention. Unfortunately, polymer fibers with radiative cooling function fabricated via a facile, continuous, large-scale and eco-friendly method have been scarcely reported. Herein, polyethylene fibers containing directional microchannels (PFCDM) are facilely fabricated via melt extrusion and water leaching. Interestingly, fabric based on such hydrophobic PFCDM shows high sunlight reflectivity (93.6%), and mid-infrared emissivity (93.9%), endowing it with remarkable PRC performance. Compared with other reported examples, the as-prepared PFDCM fabric has the highest cooling power (i.e., 104.285 W m-2) and temperature drop (i.e., 27.71 °C). Furthermore, decent self-cleaning performance can keep the PFCDM fabric away from contamination and enable it to retain an excellent radiative cooling effect. The method proposed to fabricate PFCDM in this paper will widen the potential application of thermoplastic polyolefins in the field of radiative cooling.
RESUMO
Developing novel absorbent materials targeting high-efficiency, low-energy-consumption, and environmental-friendly oil spill cleanup is still a global issue. Porous absorbents endowed with self-heating function are an attractive option because of that they are able to in-situ heat crude oil and dramatically reduce oil viscosity for efficient remediation. Herein, we facilely prepared an eco-friendly multifunctional bacterial cellulose/MXene aerogel (P-SBC/MXene aerogel) for rapid oil recovery. Thanks to excellent full solar spectrum absorption (average absorbance = 96.6 %), efficient photo-thermal conversion, and superior electrical conductivity (electrical resistance = 36 Ω), P-SBC/MXene aerogel exhibited outstanding photothermal and electrothermal capabilities. Its surface temperature could quickly reach 93 °C under 1.0 kW/m2 solar irradiation and 124 °C under 3.0 V voltage respectively, enabling effective heat transfer toward spilled oil. The produced heat significantly decreased crude oil viscosity, allowing P-SBC/MXene aerogel to rapidly absorb oil. By combining solar heating and Joule heating, P-SBC/MXene aerogel connected to a pump-assisted absorption device was capable of achieving all-weather crude oil removal from seawater (crude oil flux = 630 kg m-2 h-1). More notably, P-SBC/MXene aerogel showed splendid outdoor crude oil separation performance. Based on remarkable crude oil/seawater separation ability, the versatile aerogel provides a promising way to deal with large-area oil spills.
RESUMO
Metal-organic frameworks (MOF)-polymer hybrid hydrogel solves the processable forming of MOF powder and energy consumption of uranium extraction. However, the hybrid hydrogel by conventional synthesis methods inevitably lead to MOF agglomeration, poor filler-polymer interfacial compatibility and slowly adsorption. Herein, we designed that ZIF-67 was implanted into the carboxymethyl cellulose/polyacrylamide (CMC/PAM) by network-repairing strategy. The carboxyl and amino groups on the surface of CMC/PAM drive the uniform growth of ZIF-67 inside the CMC/PAM, which form an array of oriented and penetrating microchannels through coordination bonds. Our strategy eliminate the ZIF-67 agglomeration, increase the interfacial compatibility between MOF and polymer. The method also improve the free and fast diffusion of uranium in CMC/PAM/ZIF-67 hydrogel. According to the experimental, these enhancements synergistically enabled the CMC/PAM/ZIF-67 have a maximum adsorption capacity of 952â¯mgâ¯g-1. The adsorption process of CMC/PAM/ZIF-67 fits well with pseudo-second-order model and Langmuir isotherm. Meanwhile, the CMC/PAM/ZIF-67 maintain a high removal rate (87.3â¯%) and chemical stability even during ten adsorption-desorption cycles. It is worth noting that the adsorption amount of CMC/PAM/ZIF-67 in real seawater is 9.95â¯mgâ¯g-1 after 20â¯days, which is an ideal candidate adsorbent for uranium extraction from seawater.
Assuntos
Resinas Acrílicas , Carboximetilcelulose Sódica , Estruturas Metalorgânicas , Água do Mar , Urânio , Urânio/química , Urânio/isolamento & purificação , Adsorção , Resinas Acrílicas/química , Carboximetilcelulose Sódica/química , Estruturas Metalorgânicas/química , Água do Mar/química , Hidrogéis/química , Cinética , Purificação da Água/métodos , Poluentes Radioativos da Água/isolamento & purificação , Poluentes Radioativos da Água/químicaRESUMO
Endoscopic surgery is an effective and common clinical practice for chronic sinusitis. Nasal packing materials are applied in nasal surgery to prevent hemorrhage and promote wound healing. In this study, a degradable polyurethane foam dressing is successfully developed as a promising nasal packing material with good biocompatibility and antibacterial capability. Specifically, quaternized chitosan (QCS) serves as the crosslinker instead of polyols to offer polyurethane foam (PUF-QCS) antibacterial capability. The PUF-QCS2.0 % (with 2.0 wt% QCS) exhibits satisfactory liquid absorption capacity (19.4 g/g), high compressive strengths at both wet (14.5 kPa) and dry states (7.7 kPa), and a good degradation rate (8.3 %) within 7 days. Meanwhile, PUF-QCS2.0 % retains long-term antibacterial activity for 7 days and kills 97.3 % of S. aureus and 91.8 % of E. coli within 6 hours in antibacterial testing. Furthermore, PUF-QCS2.0 % demonstrates a positive hemostatic response in the rabbit nasal septum mucosa trauma model by reducing hemostatic time over 50.0 % and decreasing blood loss up to 76.1 % compared to the commercial PVA nasal packing sponge. Importantly, PUF-QCS also exhibits a significant antibacterial activity in nasal cavity. This nasal packing material has advantages in post-surgery bleeding control and infection prevention. STATEMENT OF SIGNIFICANCE: The performance of a nasal packing sponge requires good mechanical properties, fast and high liquid absorption rate, effective degradability and strong antibacterial activity. These features are helpful for improving the postoperative recovery and patient healing. However, integrating these into a single polyurethane foam is a challenge. In this study, quaternized chitosan (QCS) is synthesized and used as a chain extender and antibacterial agent in preparing a degradable polyurethane foam (PUF-QCS) dressing. PUF-QCS undergoes partial degradation and exhibits effective broad-spectrum antibacterial activity in 7 days. The reduction of postoperative bleeding and infection observed in the animal experiment further demonstrates that the PUF-QCS developed here outperforms the existing commercial nasal packing materials.
Assuntos
Antibacterianos , Quitosana , Poliuretanos , Poliuretanos/química , Poliuretanos/farmacologia , Quitosana/química , Quitosana/farmacologia , Coelhos , Animais , Antibacterianos/farmacologia , Antibacterianos/química , Hemostasia/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Hemostáticos/química , Hemostáticos/farmacologia , Bandagens , Escherichia coli/efeitos dos fármacos , MasculinoRESUMO
The rational use and conversion of energy are the primary means for achieving the goal of carbon neutrality. MXenes can be used for photothermal conversion, but their opaque appearance limits wider applications. Herein, we successfully develop visible-light transparent and UV-absorbing polymer composite film by solution blending the MXene with polyethylene and then vacuum pressing. The resulting film could be quickly heated to 65 °C under 400 mW cm-2 light irradiation and maintained over 85% visible-light transmittance as well as low haze (<12%). The findings of the indoor heat insulation test demonstrate that the temperature of the glass house model covered by this film was 6-7 °C lower than that of the uncovered model, revealing the potential of transparent film in energy-saving applications. In order to mimic the energy-saving condition of the building in various climates, a typical building model with this film as the outer layer of the window was created using the EnergyPlus building energy consumption software. According to predictions, they could reduce yearly refrigeration energy used by 31-61 MJ m-2, and 3%-12% of the total energy used for refrigeration in such structures. This work imply that the film has wide potential for use as transparent devices in energy-related applications.
RESUMO
Aim: Comparative effectiveness research using real-world data often involves pairwise propensity score matching to adjust for confounding bias. We show that corresponding treatment effect estimates may have limited external validity, and propose two visualization tools to clarify the target estimand. Materials & methods: We conduct a simulation study to demonstrate, with bivariate ellipses and joy plots, that differences in covariate distributions across treatment groups may affect the external validity of treatment effect estimates. We showcase how these visualization tools can facilitate the interpretation of target estimands in a case study comparing the effectiveness of teriflunomide (TERI), dimethyl fumarate (DMF) and natalizumab (NAT) on manual dexterity in patients with multiple sclerosis. Results: In the simulation study, estimates of the treatment effect greatly differed depending on the target population. For example, when comparing treatment B with C, the estimated treatment effect (and respective standard error) varied from -0.27 (0.03) to -0.37 (0.04) in the type of patients initially receiving treatment B and C, respectively. Visualization of the matched samples revealed that covariate distributions vary for each comparison and cannot be used to target one common treatment effect for the three treatment comparisons. In the case study, the bivariate distribution of age and disease duration varied across the population of patients receiving TERI, DMF or NAT. Although results suggest that DMF and NAT improve manual dexterity at 1 year compared with TERI, the effectiveness of DMF versus NAT differs depending on which target estimand is used. Conclusion: Visualization tools may help to clarify the target population in comparative effectiveness studies and resolve ambiguity about the interpretation of estimated treatment effects.
Assuntos
Crotonatos , Hidroxibutiratos , Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Nitrilas , Toluidinas , Humanos , Imunossupressores , Cloridrato de Fingolimode , Fumarato de Dimetilo/efeitos adversos , Esclerose Múltipla/tratamento farmacológicoRESUMO
Aerogels with 3D porous structures have been attracting increasing attention among functional materials due to their advantages of being lightweight and high specific surface area. Precise control of the porous structure of aerogel is essential to improve its performance. In this work, polylactic acid (PLA) aerogels with distinctly different microstructures were fabricated by precisely controlling the phase separation behavior of the ternary solution system. Rheological and theoretical analyses have revealed that the interactions between polymer molecules, solvents and non-solvents play a crucial role in determining the nucleation and growth of poor olymer and rich polymer phases. By adjusting the non-solvent type and the solution composition, aerogels with spider network structure, bead-like connected microsphere structure, and cluster petal structure were obtained. Ideal spinodal phase separation conditions were obtained to produce aerogels with a homogeneous fiber network structure. The optimum PLA aerogel achieved an extremely porosity of 96 % and a high specific surface area of 114 m2/g, which rendered it with excellent triboelectric generation performance. Thus, this work provides fundamental insights into the precise regulation of the phase separation behavior and the structure of the aerogel, which can help boost the performance and expand the applications of PLA aerogels.
RESUMO
Poor interfacial quality and low refractive index contrast (Δn) are critical challenges for the development of high-performance one-dimensional photonic crystals (1DPhCs) via solution methods that impede their optical efficiency. Herein, we introduce an innovative approach by hybridizing hollow SiO2 with poly(vinyl alcohol), referred to as PHS, followed by alternate assembly with TiO2 via spin-coating, achieving a 1DPhC with Δn = 0.76 at the wavelength of 550 nm. This method circumvents the need for high-temperature treatment and complex curing conditions, resulting in a 1DPhC with superior interfacial and optical characteristics. By adjusting the thickness of the PHS layers, we can finely tune the reflectance spectrum, attaining over 99% reflectance at the photonic band gap. Furthermore, 1DPhC demonstrates excellent adhesion to polycarbonate substrates and retains its optimal optical performance even after rigorous environmental testing, including hygrothermal cycles, exposure to hot water, friction, and solvent sonication. This research paves the way for the facile fabrication of high-performance 1DPhCs under mild conditions, offering new perspectives for photonic material processing.
RESUMO
Aim: Diroximel fumarate (DRF), ozanimod (OZA) and interferon beta-1a (IFN) are disease-modifying therapies approved for the treatment of relapsing multiple sclerosis. No randomized trials have compared DRF versus OZA and IFN. We compared DRF versus OZA and DRF versus IFN using matching-adjusted indirect comparisons for efficacy outcomes, including annualized relapse rate (ARR), 12- and 24-week confirmed disability progression (CDP) and absence of gadolinium-enhancing (Gd+) T1 lesions and new/newly enlarging T2 lesions. Patients & methods: We used individual patient data from EVOLVE-MS-1 (NCT02634307), a 2-year, open-label, single-arm, phase III study of DRF (n = 1057) and aggregate data from RADIANCE (NCT02047734), a 2-year, double-blind, phase III study that compared OZA 1 mg once daily (n = 433) and intramuscular IFN 30 µg once weekly (n = 441). To account for cross-trial differences, the EVOLVE-MS-1 population was restricted to those who met the inclusion/exclusion criteria for RADIANCE, then weighted to match the average baseline characteristics of RADIANCE. Results: After weighting, DRF and OZA had similar ARRs (0.18 and 0.17, respectively), with a rate difference (DRF vs OZA) of 0.01 (95% confidence interval [CI]: -0.04 to 0.06). DRF had a lower ARR than IFN (0.18 and 0.28, respectively), with a rate difference (DRF vs IFN) of -0.10 (95% CI: -0.16 to -0.04) after weighting. Outcomes for 12- and 24-week CDP favored DRF versus OZA; 12-week CDP favored DRF versus IFN, but there was not strong evidence favoring DRF over IFN for 24-week CDP. Compared with OZA and IFN, DRF had higher proportions of patients without Gd+ T1 lesions and patients without new/newly enlarging T2 lesions. Conclusion: Disability progression and radiological outcomes were favorable for DRF versus OZA, although no differences were observed in ARR. Clinical and radiological outcomes generally favored DRF versus IFN. These findings may be informative for patients and clinicians considering different treatment options for MS.
RESUMO
A plasmonic tilted fiber Bragg grating (TFBG)-based sensor for the detection of calcium ion (Ca2+) was proposed and demonstrated experimentally. Hydrogel material was synthesized by utilizing hydrogen bond recombination between cellulose nanocrystals (CNC) and polyvinyl alcohol (PVA). Sodium alginate (SA) was incorporated into this hydrogel material, resulting in a composite membrane with specific binding properties for Ca2+. The membrane was applied as a coating on the surface of a gold-coated TFBG. The CNC/PVA-SA modified gold on the TFBG surface enhanced the localized refractive index changes caused by variations of Ca2+ concentrations. The experimental results demonstrated an impressive limit of detection (LOD) of approximately 0.025 fM, which is five orders of magnitude better than the current LODs of similar Ca2+ sensors. And the proposed Ca2+ sensor exhibited a wide dynamic range of 10-16 M to 10-6 M.
RESUMO
Conductive hydrogels (CHs) are emerging materials for next generation sensing systems in flexible electronics. However, the fabrication of competent CHs with excellent stretchability, adhesion, self-healing, photothermal conversion, multisensing, and environmental stability remains a huge challenge. Herein, a nanocomposite organohydrogel with the above features is constructed by in situ copolymerization of zwitterionic monomer and acrylamide in the existence of carboxylic cellulose nanofiber-carrying reduced graphene oxide (rGO) plus a solvent displacement strategy. The synergy of abundant dipole-dipole interactions and intermolecular hydrogen bonds enables the organohydrogel to exhibit high stretchability, strong adhesion, and good self-healing. The presence of glycerol weakens the formation of hydrogen bonds between water molecules, endowing the organohydrogel with excellent environmental stability (-40 to 60 °C) to adapt to different application scenarios. Importantly, the multimodal organohydrogel presents excellent sensing behavior, including a high gauge factor of 16.3 at strains of 400-1440% and a reliable thermal coefficient of resistance (-4.2 °C-1) over a wide temperature widow (-40 to 60 °C). Moreover, the organohydrogel displays a highly efficient and reliable photothermal conversion ability due to the favorable optical absorbing behavior of rGO. Notably, the organohydrogel can detect accurate human activities at ambient temperature, demonstrating potential applications in flexible intelligent electronics.
RESUMO
Background: More responsive, reliable, and clinically valid endpoints of disability are essential to reduce size, duration, and burden of clinical trials in adult persons with spinal muscular atrophy (aPwSMA). Objective: The aim is to investigate the feasibility of smartphone-based assessments in aPwSMA and provide evidence on the reliability and construct validity of sensor-derived measures (SDMs) of mobility and manual dexterity collected remotely in aPwSMA. Methods: Data were collected from 59 aPwSMA (23 walkers, 20 sitters and 16 non-sitters) and 30 age-matched healthy controls (HC). SDMs were extracted from five smartphone-based tests capturing mobility and manual dexterity, which were administered in-clinic and remotely in daily life for four weeks. Reliability (Intraclass Correlation Coefficients, ICC) and construct validity (ability to discriminate between HC and aPwSMA and correlations with Revised Upper Limb Module, RULM and Hammersmith Functional Scale - Expanded HFMSE) were quantified for all SDMs. Results: The smartphone-based assessments proved feasible, with 92.1% average adherence in aPwSMA. The SDMs allowed to reliably assess both mobility and dexterity (ICCâ>â0.75 for 14/22 SDMs). Twenty-one out of 22 SDMs significantly discriminated between HC and aPwSMA. The highest correlations with the RULM were observed for SDMs from the manual dexterity tests in both non-sitters (Typing, ρ=â0.78) and sitters (Pinching, ρ=â0.75). In walkers, the highest correlation was between mobility tests and HFMSE (5 U-Turns, ρ=â0.79). Conclusions: This exploratory study provides preliminary evidence for the usability of smartphone-based assessments of mobility and manual dexterity in aPwSMA when deployed remotely in participants' daily life. Reliability and construct validity of SDMs remotely collected in real-life was demonstrated, which is a pre-requisite for their use in longitudinal trials. Additionally, three novel smartphone-based performance outcome assessments were successfully established for aPwSMA. Upon further validation of responsiveness to interventions, this technology holds potential to increase the efficiency of clinical trials in aPwSMA.