This work investigates the carrier mobility variation in <inline-formula> <tex-math notation="LaTeX">\Omega </tex-math></inline-formula>-gate silicon-on-insulator (SOI) nanowire MOS transistors ...induced by substrate (or back) biasing. The analysis is carried out through experimental measurements and 3-D TCAD simulation, performed in n-type devices with variable fin width. Mobility enhancement is observed for lower back bias levels, due to the initial conduction through the Si-BOX interface, which presents higher mobility, prior to the activation of the front channel. As back bias is increased, however, the strong substrate-induced electric field in the back channel (BC) is responsible for worsening scattering mechanisms in the BC, such as surface roughness and acoustic phonon scattering, inducing mobility degradation. The effect is amplified as the fin width increases. For short-channel devices, the use of back bias was more beneficial for mobility due to a stronger mobility enhancement and lower mobility degradation.
Display omitted
•Development of a new reactor for continuous dry anaerobic digestion (D-AD)•Yield stress, cohesion, and friction angle of biomass during D-AD were studied.•Similar physical ...degradation patterns of coarse biomass in batch and continuous.•Volatile solids decreased in 11% and yield stress in 25% at 30 days of digestion.•Yield stress evolution was well correlated with cellulose destruction (R2 = 0.99)
Knowledge of rheological evolution of biomass during dry anaerobic digestion (D-AD) is important in the engineering design, modeling, and operation of D-AD reactors. In this work, two methods of rheological analysis, the slump test and the shear-box, were used to measure the evolution of the yield stress, cohesion and friction angle of the straw-cattle manure (SCM) during the D-AD. Firstly, four 60 L batch leach-bed reactors (LBR) were started in parallel and stopped at different stages of the D-AD process on days 0, 10, 21 and 31. Secondly, a 500 L and 2 m length plug flow reactor (PFR) was operated with 40 days of solid retention time and samples were recovered at different positions. The solid degradation during D-AD process was monitored by analysis of the degradation of volatile solids, the fiber content and the Flash BMP. Similar degradation patterns of SCM and rheological evolution were observed in both reactors type. VS content decreased of 10.7% and 10.2% in 30 days in PFR and LBR respectively. VS degradation in both cases was well explained by hemicellulose and cellulose consuming in D-AD process. Considering the rheological analysis, the results showed that D-AD induced a reduction of the yield stress of 28.1 and 24.2% in 30 days in PFR and LBR respectively. Moreover, a similar evolution of cohesion and friction angle value for samples from both reactors was observed. This study demonstrates the close relationship between the state of degradation of the solid biomass and its rheological properties.
This study aims at the optimisation of a microwave pretreatment for wheat straw solubilisation and anaerobic biodegradability. The maximum yield of methane production was obtained at 150
°C with an ...improvement of 28% compared to an untreated sample. In addition, at this temperature, the time to reach 80% of the methane volume obtained from untreated straw was about 35%. The study of ramp time and holding time at targeted temperature showed that they had no improvement effect. Thus, the best conditions are the highest heating rate for a final temperature 150
°C without any holding time. The reading of energy consumed by pretreatment and energy overproduced by pretreated samples showed that increasing tVS amount and heating rate led to a saving of energy consumption. Nevertheless, to obtain a positive energy balance, a microwave device should consume less than 2.65
kJ/g
tVS.
We report the development of a new nanostructured electrochemical immunosensing platform for the detection of the Zika virus envelope protein (EP-ZIKV). For this, quantum dots (QDs) were explored in ...combination with screen-printed carbon electrodes (SPCEs) functionalized with a conductor polymeric film, formed from 2-(1H-pyrrol-1-yl)ethanamine (Pyam), and anti-EP DIII ZIKV antibodies. Carboxylated CdTe QDs were synthesized, characterized by optical and structural techniques, and covalently immobilized onto the SPCE/PPyam surface. Then, anti-EP ZIKV antibodies were also covalently conjugated to QDs. All stages of platform assembly were evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The detection of EP-ZIKV was performed by differential pulse voltammetry (DPV). Results indicated that QDs were efficiently immobilized, and did not show oxidation, under the conditions evaluated, for at least 7 months. Anti-EP ZIKV antibodies were effectively immobilized on the PPyam/QDs surface, even after 2 months of electrode storage. The platform enabled the detection of EP-ZIKV with high sensitivity using minimal sample volumes (LOD = 0.1 ng mL-1 and LOQ = 0.4 ng mL-1). The platform was also able to detect EP-ZIKV in spiked serum samples. Moreover, the platform showed specificity, not detecting the EP-DENV 3 nor a mixture of four DENV serotypes antigens. Thus, the proposed combination favored the development of a sensitive immunosensing platform, promising for the detection of Zika in the viremic phase, which also holds potential for transposition to other arboviruses.
Display omitted
•An electrochemical platform based on SPCE, QDs and polypyrrole film for Zika detection was developed.•The polymer film facilitated the charge transfer process, eliminating the need for previous SPCE treatments.•QDs immobilized on SPCEs presented (electro)chemical stability over time.•The platform enabled a specific and highly sensitive detection of the ZIKV envelope protein.
We present the first systematic study of the stellar populations of ultra-diffuse galaxies (UDGs) in the field, integrating the large area search and characterization of UDGs by the SMUDGes survey ...with the twelve-band optical photometry of the S-PLUS survey. Based on Bayesian modeling of the optical colors of UDGs, we determine the ages, metallicities, and stellar masses of 100 UDGs distributed in an area of ∼330 deg2 in the Stripe 82 region. We find that the stellar masses and metallicities of field UDGs are similar to those observed in clusters and follow the trends previously defined in studies of dwarf and giant galaxies. However, field UDGs have younger luminosity-weighted ages than do UDGs in clusters. We interpret this result to mean that field UDGs have more extended star formation histories, including some that continue to form stars at low levels to the present time. Finally, we examine stellar population scaling relations that show that UDGs are, as a population, similar to other low surface brightness galaxies.
In 1949, Donald Hebb postulated that assemblies of synchronously activated neurons are the elementary units of information processing in the brain. Despite being one of the most influential theories ...in neuroscience, Hebb's cell assembly hypothesis only started to become testable in the past two decades due to technological advances. However, while the technology for the simultaneous recording of large neuronal populations undergoes fast development, there is still a paucity of analytical methods that can properly detect and track the activity of cell assemblies. Here we describe a principal component-based method that is able to (1) identify all cell assemblies present in the neuronal population investigated, (2) determine the number of neurons involved in ensemble activity, (3) specify the precise identity of the neurons pertaining to each cell assembly, and (4) unravel the time course of the individual activity of multiple assemblies. Application of the method to multielectrode recordings of awake and behaving rats revealed that assemblies detected in the cerebral cortex and hippocampus typically contain overlapping neurons. The results indicate that the PCA method presented here is able to properly detect, track and specify neuronal assemblies, irrespective of overlapping membership.
Context.
Chariklo has two narrow and dense rings, C1R and C2R, located at 391 km and 405 km, respectively.
Aims.
In the light of new stellar occultation data, we study the stability around Chariklo. ...We also analyse three confinement mechanisms that prevent the spreading of the rings, based on shepherd satellites in resonance with the edges of the rings.
Methods.
This study was performed through a set of numerical simulations and the Poincaré surface of section technique.
Results.
From the numerical simulation results, and from the current parameters referring to the shape of Chariklo, we verify that the inner edge of the stable region is much closer to Chariklo than the rings. The Poincaré surface of sections allows us to identify periodic and quasi-periodic orbits of the first kind, and also the resonant islands corresponding to the 1:2, 2:5, and 1:3 resonances. We construct a map of
a
eq
versus
e
eq
space that gives the location and width of the stable region and the 1:2, 2:5, and 1:3 resonances.
Conclusions.
We find that the first kind periodic orbit family can be responsible for a stable region whose location and size meet that of C1R, for specific values of the ring particle eccentricities. However, C2R is located in an unstable region if the width of the ring is assumed to be about 120 m. After analysing different systems, we propose that the best confinement mechanism is composed of three satellites: two satellites shepherding the inner edge of C1R and the outer edge of C2R, and the third satellite trapped in the 1:3 resonance.
Objective
To investigate whether glycated albumin, fructosamine, and hemoglobin A1c (HbA1c) are associated with neonatal complications in newborns of pregnant women with gestational diabetes mellitus ...(GDM).
Methods
Between November 2016 and September 2017, women with a singleton pregnancy and GDM were enrolled in a prospective study in an obstetric Portuguese referral center. Glycemic markers were compared between mothers of newborns with and without complications. Multivariable logistic regression models and corresponding areas under the receiver operating characteristic curve (AUC) were used.
Results
A total of 85 women participated in the study. Raised levels of glycated albumin and fructosamine were associated with at least one neonatal complication (OR‐ odds ratio estimate: 1.33, P=0.015; OR: 1.24, P=0.027, respectively) and with respiratory disorders at birth (OR 1.41, P=0.004; OR 1.26, P=0.014, respectively). HbA1c was not associated with these outcomes. All biomarkers were associated with large‐for‐gestational age (LGA) status (OR 1.61, P<0.001; OR 1.45, P<0.001; OR 3.62, P=0.032 for glycated albumin, fructosamine, and HbA1c, respectively). All had similar AUC for at least one neonatal complication (0.82; 0.81; 0.79, respectively). For newborn respiratory disorders, AUCs were 0.83, 0.81, and 0.76, respectively, and for LGA status were 0.81, 0.79, and 0.71, respectively.
Conclusion
Raised values of glycated albumin and fructosamine were associated with particular perinatal complications in newborns of mothers with GDM, better discriminating mothers of newborns with and without complications than HbA1c.
Glycated albumin and fructosamine appear to have a stronger association than hemoglobin A1c with neonatal complications in newborns of mothers with gestational diabetes mellitus.
PDF
