154 research outputs found
On the efficient estimation of blood velocities
Pulsed wave (PW) Doppler ultrasound systems are commonly
used to examine blood flow dynamics and the technique
plays a very important role in numerous diagnostic
applications. Commonly, narrow-band PW systems estimate
the blood velocity using an autocorrelation-based estimator.
Herein, we examine a recently proposed hybrid frequency
estimator, and via extensive numerical simulations
using simulated blood scatterers show the achievable performance
gain of this method as compared to the traditional
approach
Nucleic Acid Self-Assembly Circuitry Aided by Exonuclease III for Discrimination of Single Nucleotide Variants
Robust
and rapid discrimination of one base mutations in nucleic
acid sequences is important in clinical applications. Here, we report
a hybridization-based assay exploiting nucleic acid self-assembly
circuitry and enzyme exonuclease III (Exo III) for the differentiation
of single nucleotide variants (SNVs). This one-step approach combines
the merits of discrimination power of competitive DNA hybridization
probes (probe + sink) with catalytic amplification assisted by Exo
III. The phosphorothioate bonds modified on a wild-type (WT) specific
sink inhibit the Exo III digestion; thus, subsequent catalytic amplification
magnifies only the intended SNV targets. The integrated assay exhibits
improved SNV discrimination rather than hybridization probes relying
solely on competition or amplification and enables SNV detection at
1% abundance. Two frequent cancer-driver mutation sequences (EGFR-L861Q,
NRAS-Q61K) were tested. Our strategy allows simple sequence design
and can easily adapt to multianalyte SNV detections
On the Efficient Estimation of Blood Velocities
Pulsed wave (PW) Doppler ultrasound systems are commonly
used to examine blood flow dynamics and the technique
plays a very important role in numerous diagnostic
applications. Commonly, narrow-band PW systems estimate
the blood velocity using an autocorrelation-based estimator.
Herein, we examine a recently proposed hybrid frequency
estimator, and via extensive numerical simulations
using simulated blood scatterers show the achievable performance
gain of this method as compared to the traditional
approach
Rapid-Forming and Self-Healing Agarose-Based Hydrogels for Tissue Adhesives and Potential Wound Dressings
To
meet the progressive requirements of advanced engineering materials
with superior physicochemical performances, self-healing and injectable
hydrogels (AD hydrogels) based on agarose with pH-response were prepared
through dynamic covalent Schiff-base linkages by simply mixing nontoxic
agarose–ethylenediamine conjugate (AG-NH<sub>2</sub>) and dialdehyde-functionalized
polyethylene glycol (DF-PEG) solutions. The self-healing and injectable
capabilities of the hydrogels without any external stimulus are ascribed
to dynamic covalent Schiff-base linkages between the aldehyde groups
of DF-PEG and amine groups on AG-NH<sub>2</sub> backbone. It is demonstrated
that the AD hydrogels possess interconnected porous morphologies,
rapid gelation time, excellent deformability, and good mechanical
strength. The incorporated Schiff’s base imparts the hydrogels
to the remarkable tissue adhesiveness. In vivo hemostatic tests on
rabbit liver demonstrate that the hydrogels are able to stanch the
severe trauma effectively. Compared with the conventional gauze treatment,
the total amount of bleeding sharply declined to be (0.19 ± 0.03)
g, and hemostasis time was strikingly shorter than 10 s after treating
with AD hydrogels. In summary, the self-healing ability, cytocompatibility,
and adhesion characteristic of the pH-responsive hydrogels make them
promising candidates for long-lived wound dressings in critical situations
Joint optimization of green vehicle scheduling and routing problem with time-varying speeds
<div><p>Based on an analysis of the congestion effect and changes in the speed of vehicle flow during morning and evening peaks in a large- or medium-sized city, the piecewise function is used to capture the rules of the time-varying speed of vehicles, which are very important in modelling their fuel consumption and CO<sub>2</sub> emission. A joint optimization model of the green vehicle scheduling and routing problem with time-varying speeds is presented in this study. Extra wages during nonworking periods and soft time-window constraints are considered. A heuristic algorithm based on the adaptive large neighborhood search algorithm is also presented. Finally, a numerical simulation example is provided to illustrate the optimization model and its algorithm. Results show that, (1) the shortest route is not necessarily the route that consumes the least energy, (2) the departure time influences the vehicle fuel consumption and CO<sub>2</sub> emissions and the optimal departure time saves on fuel consumption and reduces CO<sub>2</sub> emissions by up to 5.4%, and (3) extra driver wages have significant effects on routing and departure time slot decisions.</p></div
Flowchart of adaptive large neighborhood search algorithm.
<p>Flowchart of adaptive large neighborhood search algorithm.</p
Rapid-Forming and Self-Healing Agarose-Based Hydrogels for Tissue Adhesives and Potential Wound Dressings
To
meet the progressive requirements of advanced engineering materials
with superior physicochemical performances, self-healing and injectable
hydrogels (AD hydrogels) based on agarose with pH-response were prepared
through dynamic covalent Schiff-base linkages by simply mixing nontoxic
agarose–ethylenediamine conjugate (AG-NH<sub>2</sub>) and dialdehyde-functionalized
polyethylene glycol (DF-PEG) solutions. The self-healing and injectable
capabilities of the hydrogels without any external stimulus are ascribed
to dynamic covalent Schiff-base linkages between the aldehyde groups
of DF-PEG and amine groups on AG-NH<sub>2</sub> backbone. It is demonstrated
that the AD hydrogels possess interconnected porous morphologies,
rapid gelation time, excellent deformability, and good mechanical
strength. The incorporated Schiff’s base imparts the hydrogels
to the remarkable tissue adhesiveness. In vivo hemostatic tests on
rabbit liver demonstrate that the hydrogels are able to stanch the
severe trauma effectively. Compared with the conventional gauze treatment,
the total amount of bleeding sharply declined to be (0.19 ± 0.03)
g, and hemostasis time was strikingly shorter than 10 s after treating
with AD hydrogels. In summary, the self-healing ability, cytocompatibility,
and adhesion characteristic of the pH-responsive hydrogels make them
promising candidates for long-lived wound dressings in critical situations
Comparative analysis of system performances with extra wages during overtime periods.
<p>Comparative analysis of system performances with extra wages during overtime periods.</p
Multichannel Charge Transport of a BiVO<sub>4</sub>/(RGO/WO<sub>3</sub>)/W<sub>18</sub>O<sub>49</sub> Three-Storey Anode for Greatly Enhanced Photoelectrochemical Efficiency
Photoelectrochemical
(PEC) solar conversion is a green strategy for addressing the energy
crisis. In this study, a three-storey nanostructure BiVO<sub>4</sub>/(RGO/WO<sub>3</sub>)/W<sub>18</sub>O<sub>49</sub> was fabricated
as a PEC photoanode and demonstrated a highly enhanced PEC efficiency.
The top and middle storeys are a reduced graphene oxide (RGO) layer
and WO<sub>3</sub> nanorods (NRs) decorated with BiVO<sub>4</sub> nanoparticles
(NPs), respectively. The bottom storey is the W<sub>18</sub>O<sub>49</sub> film grown on a pure W substrate. In this novel design,
experiments and modeling together demonstrated that the RGO layer
and WO<sub>3</sub> NRs with a fast carrier mobility can serve as multichannel
pathways, sharing and facilitating electron transport from the BiVO<sub>4</sub> NPs to the W<sub>18</sub>O<sub>49</sub> film. The high conductivity
of W<sub>18</sub>O<sub>49</sub> can further enhance the charge transfer
and retard electron–hole recombination, leading to a highly
improved PEC efficiency of the BiVO<sub>4</sub>/WO<sub>3</sub> heterojunction.
As a result, the as-fabricated three-storey photoanode covered with
FeOOH/NiOOH achieves an attractive PEC photocurrent density of 4.66
mA/cm<sup>2</sup> at 1.5 V versus Ag/AgCl, which illustrates the promising
potential of the three-storey hetero-nanostructure in future photoconversion
applications
Rapid-Forming and Self-Healing Agarose-Based Hydrogels for Tissue Adhesives and Potential Wound Dressings
To
meet the progressive requirements of advanced engineering materials
with superior physicochemical performances, self-healing and injectable
hydrogels (AD hydrogels) based on agarose with pH-response were prepared
through dynamic covalent Schiff-base linkages by simply mixing nontoxic
agarose–ethylenediamine conjugate (AG-NH<sub>2</sub>) and dialdehyde-functionalized
polyethylene glycol (DF-PEG) solutions. The self-healing and injectable
capabilities of the hydrogels without any external stimulus are ascribed
to dynamic covalent Schiff-base linkages between the aldehyde groups
of DF-PEG and amine groups on AG-NH<sub>2</sub> backbone. It is demonstrated
that the AD hydrogels possess interconnected porous morphologies,
rapid gelation time, excellent deformability, and good mechanical
strength. The incorporated Schiff’s base imparts the hydrogels
to the remarkable tissue adhesiveness. In vivo hemostatic tests on
rabbit liver demonstrate that the hydrogels are able to stanch the
severe trauma effectively. Compared with the conventional gauze treatment,
the total amount of bleeding sharply declined to be (0.19 ± 0.03)
g, and hemostasis time was strikingly shorter than 10 s after treating
with AD hydrogels. In summary, the self-healing ability, cytocompatibility,
and adhesion characteristic of the pH-responsive hydrogels make them
promising candidates for long-lived wound dressings in critical situations
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