132 research outputs found
Fiber reinforced polymer culvert bridgesâa feasibility study from structural and lcc points of view
Soilâsteel composite bridges (SSCB) have become increasingly popular for short-span bridges as an alternative to concrete slab bridges mainly due to their low initial cost, rapid manufac-ture, simplified construction, and geometrical adaptability. SSCBs have a variety of applications and can be used over waterways or roadways. While conventional bridges tend to lose their load-carrying capacity due to degradation, SSCBs gain strength because of backfill soil consolidation. However, the load carrying capacity and integrity of such structures highly depends on the condition and load-carrying capacity of the steel arch element. A major drawback of SSCBs, especially those located on waterways or with poor drainage, is corrosion and subsequent loss of cross-sectional capacity. Unfortunately, the inspection of such bridges is not straightforward and any damage/collapse will be very costly to repair/replace. Fiber reinforced polymer (FRP) composites offer an attractive alternative to replace the steel in these types of bridges. FRP composites have significantly improved durability characteristics compared to steel, which will reduce maintenance costs and improve life-cycle costs (LLCs). This paper presents a new concept to use glass FRP as a construction material to construct soilâFRP composite bridges (SFCB). Various aspects of design and manufacturing are presented along with results and conclusions from a case study involving alternative bridge designs in steel and FRP composites
Fe73.5Si13.5B9Cu1Nb3 metallic glass: Rapid activation of peroxymonosulfate towards ultrafast Eosin Y degradation
Discovering functional applications of metallic glasses (MGs) as heterogeneous catalysts is a fundamental and essential topic. This work reports the rapid production of sulfate radicals (SO4â) from peroxymonosulfate (PMS) using Fe73.5Si13.5B9Cu1Nb3 glassy ribbons as catalysts for Eosin Y (EY) dye wastewater treatment. The reaction rates (k) from the experimental data reveal that the EY degradation is well fitted with the pseudo-first-order kinetic model. The strong electron transfer ability is characterized by electrochemical methods, presenting an advanced catalytic performance for EY degradation. Various experimental parameters, including dye concentration, catalyst dosage, PMS concentration, light intensity, pH and reaction temperature as well as the saline and natural inorganic effects, are fully investigated. The results show that the color removal of EY dye could achieve nearly 100% within 20 min. The quenching experiments are performed to verify the production of reactive species, suggesting that both OH and SO4â are produced from PMS and play significant roles in EY degradation. This critical study reveals that using Fe73.5Si13.5B9Cu1Nb3 MGs as catalysts exhibits a superior reactivity on PMS activation in wastewater treatment. The discoveries shed lights into the study of electron transfer ability for MGs, presenting extensive prospects in the application of dye wastewater treatment
LGR5+ epithelial tumor stem-like cells generate a 3D-organoid model for ameloblastoma
Ameloblastoma (AM) is a benign but locally aggressive tumor with high recurrences. Currently, underlying pathophysiology remains elusive, and radical surgery remains the most definitive treatment with severe morbidities. We have recently reported that AM harbors a subpopulation of tumor epithelial stem-like cells (AM-EpiSCs). Herein, we explored whether LGR5+ epithelial cells in AM possess stem-like cell properties and their potential contribution to pathogenesis and recurrence of AM. We found that LGR5 and stem cell-related genes were co-expressed in a subpopulation of AM epithelial cells both in vivo and in vitro, which were enriched under 3D-spheroid culture. As compared to LGR5â counterparts, LGR5+ AM epithelial cells showed increased expression of various EMT- and stemness-related genes, and functionally, exhibited increased capacity to form 3D-spheroids and generate human tumor 3D organoids, which recapitulated the histopathologic features of distinct subtypes of solid AM, thus, contributing a useful human tumor platform for targeted therapeutic screening. Treatment with a selective BRAFV600E inhibitor, vemurafenib, unexpectedly enriched the subpopulation of LGR5+ AM-EpiSCs in tumor 3D organoids, which may have explained therapeutic resistances and recurrences. These findings suggest that LGR5+ AM-EpiSCs play a pivotal role in pathogenesis and progression of AM and targeted inhibition of both BRAF and LGR5 potentially serves a novel nonsurgical adjuvant therapeutic approach for this aggressively benign jaw tumor. © 2020, The Author(s)
Phase-resolved real-time forecasting of three-dimensional ocean waves via machine learning and wave tank experiments
Accurate prediction of ocean waves plays an essential role in many ocean engineering applications, such as the control of wave energy converters and floating wind turbines. However, existing studies on phase-resolved wave prediction using machine learning mainly focus on two-dimensional wave data, while ocean waves are usually three-dimensional. In this work, we investigate, for the first time, the phase-resolved real-time prediction of three-dimensional waves using machine learning methods. Specifically, the wave prediction is modeled as a supervised learning task aiming at learning mapping relationships between the input historical wave data and the output future wave elevations. Four frequently-used machine learning methods are employed to tackle this task and a novel Dual-Branch Network (DBNet) is proposed for performance improvement. A group of wave basin experiments with nine directional wave spectra under three sea states are first conducted to collect the data of 3D waves. Then the wave data are used for verifying the effectiveness of the machine learning methods. The results demonstrate that the upstream wave data measured by the gauge array can be used for control-oriented wave forecasting with a forecasting horizon of more than 20 s, where the directional information provided by the upstream gauge array is vital for accurately predicting the downstream wave elevations. In addition, further investigations show that by using only local wave data (which can be easily obtained), the very short-term phase-resolved prediction (less than 5 s) can be achieved
Three-dimensional structure determination from a single view
The ability to determine the structure of matter in three dimensions has
profoundly advanced our understanding of nature. Traditionally, the most widely
used schemes for 3D structure determination of an object are implemented by
acquiring multiple measurements over various sample orientations, as in the
case of crystallography and tomography (1,2), or by scanning a series of thin
sections through the sample, as in confocal microscopy (3). Here we present a
3D imaging modality, termed ankylography (derived from the Greek words ankylos
meaning 'curved' and graphein meaning 'writing'), which enables complete 3D
structure determination from a single exposure using a monochromatic incident
beam. We demonstrate that when the diffraction pattern of a finite object is
sampled at a sufficiently fine scale on the Ewald sphere, the 3D structure of
the object is determined by the 2D spherical pattern. We confirm the
theoretical analysis by performing 3D numerical reconstructions of a sodium
silicate glass structure at 2 Angstrom resolution and a single poliovirus at 2
- 3 nm resolution from 2D spherical diffraction patterns alone. Using
diffraction data from a soft X-ray laser, we demonstrate that ankylography is
experimentally feasible by obtaining a 3D image of a test object from a single
2D diffraction pattern. This approach of obtaining complete 3D structure
information from a single view is anticipated to find broad applications in the
physical and life sciences. As X-ray free electron lasers (X-FEL) and other
coherent X-ray sources are under rapid development worldwide, ankylography
potentially opens a door to determining the 3D structure of a biological
specimen in a single pulse and allowing for time-resolved 3D structure
determination of disordered materials.Comment: 30 page
In Vitro and Sensory Evaluation of Capsaicin-Loaded Nanoformulations
Capsaicin has known health beneficial and therapeutic properties. It is also able to enhance the permeability of drugs across epithelial tissues. Unfortunately, due to its pungency the oral administration of capsaicin is limited. To this end, we assessed the effect of nanoencapsulation of capsaicin, under the hypothesis that this would reduce its pungency. Core-shell nanocapsules with an oily core and stabilized with phospholipids were used. This system was used with or without chitosan coating. In this work, we investigated the in vitro release behavior of capsaicin-loaded formulations in different physiological media (including simulated saliva fluid). We also evaluated the influence of encapsulation of capsaicin on the cell viability of buccal cells (TR146). To study the changes in pungency after encapsulation we carried out a sensory analysis with a trained panel of 24 students. The in vitro release study showed that the systems discharged capsaicin slowly in a monotonic manner and that the chitosan coating had an effect on the release profile. The cytotoxic response of TR146 cells to capsaicin at a concentration of 500 ÎŒM, which was evident for the free compound, was reduced following its encapsulation. The sensory study revealed that a chitosan coating results in a lower threshold of perception of the formulation. The nanoencapsulation of capsaicin resulted in attenuation of the sensation of pungency significantly. However, the presence of a chitosan shell around the nanoformulations did not mask the pungency, when compared with uncoated systems
Naturalization of the microbiota developmental trajectory of Cesarean-born neonates after vaginal seeding
Early microbiota perturbations are associated with disorders that involve immunological underpinnings. Cesarean section (CS)-born babies show altered microbiota development in relation to babies born vaginally. Here we present the first statistically powered longitudinal study to determine the effect of restoring exposure to maternal vaginal fluids after CS birth.This work was partially supported by the C&D Research Fund, the Emch Fund for Human Microbiome Studies, and CIFAR FS20-078 #125869 (to M.G.D.-B.); Chilean CONICYT PIA/ANILLO grant ACT172097 and Chilean SOCHIPE Project 022019 (to P.R.H.); and the Norwegian Institute of Public Health (2019-0350), the Emerald Foundation, an NIH Pioneer award (1DP1AT010885), the National Institute of Justice (2016-DN-BX-4194), the San Diego Digestive Diseases Research Center (NIDDK 1P30DK120515), Janssen Pharmaceuticals (20175015)Peer reviewe
RNA-Seq analysis of yak ovary: improving yak gene structure information and mining reproduction-related genes
2021 roadmap for sodium-ion batteries
Abstract: Increasing concerns regarding the sustainability of lithium sources, due to their limited availability and consequent expected price increase, have raised awareness of the importance of developing alternative energy-storage candidates that can sustain the ever-growing energy demand. Furthermore, limitations on the availability of the transition metals used in the manufacturing of cathode materials, together with questionable mining practices, are driving development towards more sustainable elements. Given the uniformly high abundance and cost-effectiveness of sodium, as well as its very suitable redox potential (close to that of lithium), sodium-ion battery technology offers tremendous potential to be a counterpart to lithium-ion batteries (LIBs) in different application scenarios, such as stationary energy storage and low-cost vehicles. This potential is reflected by the major investments that are being made by industry in a wide variety of markets and in diverse material combinations. Despite the associated advantages of being a drop-in replacement for LIBs, there are remarkable differences in the physicochemical properties between sodium and lithium that give rise to different behaviours, for example, different coordination preferences in compounds, desolvation energies, or solubility of the solidâelectrolyte interphase inorganic salt components. This demands a more detailed study of the underlying physical and chemical processes occurring in sodium-ion batteries and allows great scope for groundbreaking advances in the field, from lab-scale to scale-up. This roadmap provides an extensive review by experts in academia and industry of the current state of the art in 2021 and the different research directions and strategies currently underway to improve the performance of sodium-ion batteries. The aim is to provide an opinion with respect to the current challenges and opportunities, from the fundamental properties to the practical applications of this technology
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