Showing papers by "University of Arkansas published in 2022"
TL;DR: A hybrid five-variable modulation scheme with minimal root mean square (rms) current is proposed in this article, which combines the traditional phase-shift and pulsewidth modulation schemes, which significantly improves the efficiency of the DAB converter.
Abstract: In order to further improve the efficiency of dual-active-bridge (DAB) converter, a hybrid five-variable modulation scheme with minimal root mean square (rms) current is proposed in this article, which combines the traditional phase-shift and pulsewidth modulation schemes. By adopting the proposed optimal scheme, a wider zero-voltage switching (ZVS) operation range and lower rms current level are achieved simultaneously when compared with other modulation schemes, which significantly improves the efficiency of the DAB converter. Moreover, for the complexity of the proposed modulation scheme with five variables, the Fourier decomposition based analytical expressions are derived for the converter and a generalized performance analysis results are presented. Besides, in order to avoid the analysis error, especially at light-load condition, the optimization strategy takes the rms current as the optimal objective, which includes the eight harmonic component of the inductor current rather than just considers the fundamental component. And an offline particle swarm optimization algorithm is introduced to acquire the optimal operating points for the whole power range. To substantiate the effectiveness of the proposed modulation scheme, a comprehensive comparison among related works in terms of the rms value and ZVS range were carried out under various operation condition. Finally, a 1.2 kW experimental platform was built and the highest experimental efficiency under the proposed modulation scheme reaches 96.8%.
28 citations
TL;DR: In this article , a universal method for the synthesis of compact heterojunction VS2@C3N4 with S vacancies via in situ supramolecular self-assembly method was developed.
23 citations
TL;DR: Two-stage risk-averse and risk-neutral stochastic optimization models are proposed to schedule repair activities for a disrupted CI network with the objective of maximizing system resilience and assessing the risks associated with post-disruption scheduling plans.
22 citations
TL;DR: In this article, a novel smart hydrogel composed of NIPAM, Laponite nanoclay, and NdFeB magnetic particles was synthesized for 4D printing of robots.
Abstract: Soft materials, which use both internal energy change and external energy supply to produce shape morphing and motion, are essential for the development of robotics. Four-dimensional (4D) printing is a promising method for fabricating soft robots with arbitrary structures. However, there are still few hybrid soft robots that can be manufactured by 4D printing because of the physicochemical nature of the materials. In this study, a novel smart hydrogel composed of NIPAM, Laponite nanoclay, and NdFeB magnetic particles, which have simultaneous temperature sensation and magnetic actuation, was synthesized for 4D printing of robots. It has been proven that this material has good mechanical properties and excellent machinability and biocompatibility. Soft millirobots with different structures and functions were printed, including a catheter with a multi-segment magnetic head, a leptasteria-like robot, and a shellfish-like robot, which can respond to both magnetic and thermal fields. The locomotion of the millirobot has been verified to overcome physical obstacles in the human stomach model and complete active transportation of cargo. The synergistic responses to the magnetic field and thermal field make the robot more adaptable and reduce the leakage of drugs during transportation. The 4D printed soft millirobots will promote the application prospects of robots in the fields of bioengineering and medical treatment.
20 citations
TL;DR: In this paper, a comprehensive theoretical study is presented to evaluate the achievable performance of Ge1-xSnx p-i-n homojunction photodetectors with strain-free and defect-free active layer for the purpose of demonstrating its potential in advancing the MIR detection technology.
Abstract: Ge1-xSnx photodetectors (PDs) have emerged as a new type of mid-infrared (MIR) CMOS-compatible PDs for a wide range of applications. Here we present a comprehensive theoretical study to evaluate the achievable performance of Ge1-xSnx p-i-n homojunction PDs with strain-free and defect-free Ge1-xSnx active layer for the purpose of demonstrating its potential in advancing the MIR detection technology. Starting from the Sn-composition-dependent band structures, the theoretical model calculates optical absorption, responsivity, dark current density, and detectivity. The results show that the optical responsivity can be enhanced with the Sn incorporation due to the improved optical absorption and the large mobilities and diffusion lengths of the photo-generated electrons and holes. The dark current density, however, increases with the increasing Sn composition. Our model suggests that not only the photodetection range of the Ge1-xSnx PDs can be extended to the MIR region but their detectivity at room temperature can be competitive with the existing MIR technology, and in some cases better than some commercial PDs operating at lower temperatures. This study establishes the ultimate performance that can be potentially achieved with the Ge1-xSnx MIR technology with the maturity of its material development in due time in addition to its much anticipated CMOS-compatible advantages.
15 citations
TL;DR: In this paper, the authors compare 17 widely-used dense-gas dispersion models using observations from the Jack Rabbit II (JR II) chlorine release experiments, which were led by the U.S. Department of Homeland Security Science & Technology (DHS S&T) Chemical Security Analysis Center (CSAC) and a collaborative team of inter-agency partners, and conducted at the Army Dugway Proving Ground in 2015 and 2016.
14 citations
TL;DR: In this paper , the authors investigated the potential contribution of gut microbes to HIRI and found that 3,4-dihydroxyphenylpropionic acid inhibited histone deacetylase activity by reducing its phosphorylation.
13 citations
TL;DR: In this article , a spatiotemporally resolved method for the detection and quantification of cell-cell interactions via Photocatalytic proXimity CELl Labeling (PhoXCELL) is presented.
Abstract: Quantitative detection and characterization of antigen-specific T cells are crucial to our understanding of immune responses as well as the development of new immunotherapies. Herein, we report a spatiotemporally resolved method for the detection and quantification of cell-cell interactions via Photocatalytic proXimity CELl Labeling (PhoXCELL). The biocompatible photosensitizer dibromofluorescein (DBF) was leveraged and optimized as a nongenetic alternative of enzymatic approaches for efficient generation of singlet oxygen upon photoirradiation (520 nm) on the cell surface, which allowed the subsequent labeling of nearby oxidized proteins with primary aliphatic amine-based probes. We demonstrated that DBF-functionalized dendritic cells (DCs) could spatiotemporally label interacting T cells in immune synapses via rapid photoirradiation with quantitatively discriminated interaction strength, which revealed distinct gene signatures for T cells that strongly interact with antigen-pulsed DCs. Furthermore, we employed PhoXCELL to simultaneously detect tumor antigen-specific CD8+ as well as CD4+ T cells from tumor-infiltrating lymphocytes and draining lymph nodes in murine tumor models, enabling PhoXCELL as a powerful platform to identify antigen-specific T cells in T cell receptor (TCR)-relevant personal immunotherapy.
13 citations
TL;DR: Wang et al. as mentioned in this paper used Cox proportional hazards models to investigate the associations between RAR and mortality of heart failure patients, and found that high levels of RAR significantly increased the risk of sepsis and requirement for renal replacement therapy.
12 citations
TL;DR: In this article , the authors explored the physiological and DNA methylation changes in kenaf seedlings grown under different concentrations (from 0 to 600 μM) of chromium stress.
11 citations
TL;DR: In this paper , anatase/bate crystal phase titanium dioxide nanotubes (TiO2 NTs) combined with reduced graphene oxide (RGO) were used to modify the initial polypropylene separator.
TL;DR: In this article , a simple electrochemical immunosensor is demonstrated based on gold nanoparticles (AuNPs) electrodeposited on chitosan-reduced graphene oxide (CS-G) composite modified electrode, which can achieve sensitive determination of the important biomarker of bone metabolism.
Abstract: Ultrasensitive and selective determination of biomarkers of the bone metabolism in serum is crucial for early screening, timely treatment, and monitoring of the curative effect of osteoporosis, which is a silent disease with serious health threats. Immunoassay with a simple sensing interface and ultrahigh sensitivity is highly desirable. Herein, a simple electrochemical immunosensor is demonstrated based on gold nanoparticles (AuNPs) electrodeposited on chitosan-reduced graphene oxide (CS-G) composite modified electrode, which can achieve sensitive determination of the important biomarker of bone metabolism, bone gamma-carboxyglutamate protein (BGP). To overcome the agglomeration of graphene and introduce a biocompatible matrix with functional amino groups, CS-G is prepared and modified on the supporting glassy carbon electrode (GCE). Then, AuNPs are electrodeposited on CS-G through their interaction between amine groups of CS. The immobilized AuNPs provide numerous binding sites to immobilize anti-BGP antibodies (AbBGP). The specific recognition between BGP and AbBGP results in a reduction in the mass transfer of the electrochemical probe (Fe(CN)63-/4-) in solution, leading to a reduced electrochemical signal. Based on this mechanism, fast and ultrasensitive electrochemical detection of BGP is achieved when the concentration of BGP ranges from 100 ag ml-1 to 10 μg mL-1 with a limit of detection (LOD) of 20 ag ml-1 (S/N = 3). The determination of BGP in human serum is also realized with high reliability.
TL;DR: In this paper, the authors explored the physiological and DNA methylation changes in kenaf seedlings grown under different concentrations (from 0 to 600μM) of chromium stress.
TL;DR: In this paper, anatase/bate crystal phase titanium dioxide nanotubes (TiO2 NTs) combined with reduced graphene oxide (RGO) to modify the initial polypropylene separator not only localizes the migrating polysulfides by the common effects of chemical binding and physical adsorption but also enhances the lithium ion migration by reducing the electrochemical resistance.
TL;DR: In this paper, the authors evaluated energy flow and environmental footprints of coffee-pepper farms of Karnataka, India, using both data envelopment analysis (DEA) and Life cycle Assessment (LCA) methodologies.
TL;DR: A review of the historical background of Salmonella assessment in poultry at the processing plant along with the problems inherent with current methods is presented in this paper, along with opportunities for improvement via the availability of emerging detection and identification technologies as well as other food safety measures that can be taken such as consumer education.
TL;DR: In this paper , a mesoscale model was developed based on the random distribution of coarse aggregate, in which the peak strain, elastic modulus, and the descending coefficient of mortar were modified compared with that of concrete.
TL;DR: In this article , the edge and bridge units embedded in carbon nitride frameworks have been well-designed via a facile polymerization method to boost exciton dissociation and charge separation.
Abstract: Edge and bridge units embedded in carbon nitride frameworks have been well-designed via a facile polymerization method to boost exciton dissociation and charge separation.
TL;DR: In this paper, a Raman microscope equipped with an environmental chamber and a single particle optical levitator was used to determine the ability of sodium and magnesium chlorate salts to take up water vapor at low temperatures (296-K to 237-K).
TL;DR: In this article , the authors used a natural evolutionary experiment to understand how diatoms respond to low salinity, characterized transcriptomic responses of acclimated S. marinoi grown in a common garden.
Abstract: The salinity gradient separating marine and freshwater environments represents a major ecological divide for microbiota, yet the mechanisms by which marine microbes have adapted to and ultimately diversified in freshwater environments are poorly understood. Here, we take advantage of a natural evolutionary experiment: the colonization of the brackish Baltic Sea by the ancestrally marine diatom Skeletonema marinoi. To understand how diatoms respond to low salinity, we characterized transcriptomic responses of acclimated S. marinoi grown in a common garden. Our experiment included eight strains from source populations spanning the Baltic Sea salinity cline. Gene expression analysis revealed that low salinities induced changes in the cellular metabolism of S. marinoi, including upregulation of photosynthesis and storage compound biosynthesis, increased nutrient demand, and a complex response to oxidative stress. However, the strain effect overshadowed the salinity effect, as strains differed significantly in their response, both regarding the strength and the strategy (direction of gene expression) of their response. The high degree of intraspecific variation in gene expression observed here highlights an important but often overlooked source of biological variation associated with how diatoms respond to environmental change.
TL;DR: In this paper, the authors developed a figure of merit (FOM) that characterizes the efficacy of evaporative heat transfer from microstructured surfaces, which can serve as a tool to survey available structures and also optimize their dimensions for heat and mass transfer enhancement.
TL;DR: Wang et al. as mentioned in this paper developed a multiplex panel of 40 highly polymorphic microhaplotypes for the Chinese Han population, evaluated its forensic values, and explored its application in predicting the number of contributors (NOCs) in DNA mixtures.
Abstract: Microhaplotypes (MHs) have great potential in multiple forensic applications and have proven to be promising markers in complex DNA mixture analysis. In this study, we developed a multiplex panel of 40 highly polymorphic MHs for the Chinese Han population, evaluated its forensic values, and explored its application in predicting the number of contributors (NOCs) in DNA mixtures. The panel consisted of 20 newly proposed loci and 20 previously reported loci with lengths spanning less than 120 bp. The average effective number of alleles (Ae) was 3.77, and the cumulative matching probability (CMP) and the cumulative power of exclusion (CPE) reached 1.2E-37 and 1–2.1E-12, respectively, in the Chinese Han population from the 1000 Genomes Project. Further validation on 150 Chinese Han individuals showed that Ae ranged from 2.62 to 4.41 with a mean value of 3.61, and CMP and CPE were 3.61E-36 and 1–1.84E-12, respectively, indicating that this panel was informative for personal identification and paternity testing in the studied population. To estimate NOC in DNA mixtures, we developed a machine learning model based on this panel. As a result, the accuracies in artificial DNA mixtures reached 95.24% for 2- to 4-person mixtures and 83.33% for 2- to 6-person mixtures. Furthermore, the NOC estimation on simulated profiles with allele dropout showed that this panel was still robust under slight dropout. In conclusion, this panel has value for forensic identification and NOC estimation of DNA mixtures.
TL;DR: Wang et al. as discussed by the authors developed a multiplex panel of 40 highly polymorphic microhaplotypes for the Chinese Han population, evaluated its forensic values, and explored its application in predicting the number of contributors (NOCs) in DNA mixtures.
Abstract: Microhaplotypes (MHs) have great potential in multiple forensic applications and have proven to be promising markers in complex DNA mixture analysis. In this study, we developed a multiplex panel of 40 highly polymorphic MHs for the Chinese Han population, evaluated its forensic values, and explored its application in predicting the number of contributors (NOCs) in DNA mixtures. The panel consisted of 20 newly proposed loci and 20 previously reported loci with lengths spanning less than 120 bp. The average effective number of alleles (Ae) was 3.77, and the cumulative matching probability (CMP) and the cumulative power of exclusion (CPE) reached 1.2E-37 and 1-2.1E-12, respectively, in the Chinese Han population from the 1000 Genomes Project. Further validation on 150 Chinese Han individuals showed that Ae ranged from 2.62 to 4.41 with a mean value of 3.61, and CMP and CPE were 3.61E-36 and 1-1.84E-12, respectively, indicating that this panel was informative for personal identification and paternity testing in the studied population. To estimate NOC in DNA mixtures, we developed a machine learning model based on this panel. As a result, the accuracies in artificial DNA mixtures reached 95.24% for 2- to 4-person mixtures and 83.33% for 2- to 6-person mixtures. Furthermore, the NOC estimation on simulated profiles with allele dropout showed that this panel was still robust under slight dropout. In conclusion, this panel has value for forensic identification and NOC estimation of DNA mixtures.
TL;DR: In this paper , an electrochemical aptasensor has been developed to determine K+ using electrochemical impedance spectroscopy, where the polyaniline (PANI) coating was first electrodeposited on a GCE, and then the potassium-selective aptamer [G3(T2AG3)3] was adsorbed through an electrostatic force between PANI and aptamer.
TL;DR: In this article, the surface organic ligands of CdSe/CdS@ZnO QDs were successfully prepared by ZnO sol as surface ligands, which showed the remarkably enhanced photostability and biexciton lifetime, and further suppressed Auger process and PL blinking.
TL;DR: Wang et al. as discussed by the authors used immunohistochemistry, western blot, and real-time polymerase chain reaction (RT-PCR) to detect protein and mRNA expression levels of VEGF-A and TGF-β1 in skin tissues after treatment with PPE.
TL;DR: In this paper, the effect of GQD on type 2 diabetes osteoporosis (T2DOP) was observed in db/db mice in four groups: model group, low-dose group (GQD-L), gQD high-dose groups (GQLD-H), and metformin (positive control) group.
TL;DR: In this paper , a systematic review and meta-analysis examined the characteristics and effectiveness of pregnancy yoga interventions, incorporating the FITT (frequency, intensity, time/duration and type) principle of exercise prescription.
Abstract: Yoga is a popular mind-body medicine frequently recommended to pregnant women. Gaps remain in our understanding of the core components of effective pregnancy yoga programmes. This systematic review and meta-analysis examined the characteristics and effectiveness of pregnancy yoga interventions, incorporating the FITT (frequency, intensity, time/duration and type) principle of exercise prescription.Nine electronic databases were searched: MEDLINE, PsycINFO, EMBASE, CINAHL, WHOLiS, AMED, ScieLo, ASSIA and Web of Science. Randomised control trials and quasi-experimental studies examining pregnancy yoga interventions were eligible. Covidence was used to screen titles, abstracts, and full-text articles. Outcomes of interest were stress, anxiety, depression, quality of life, labour duration, pain management in labour and mode of birth. The Cochrane Collaboration's Risk of Bias Assessment tool was used to assess methodological quality of studies and GRADE criteria (GRADEpro) evaluated quality of the evidence. Meta-analysis was performed using RevMan 5.3.Of 862 citations retrieved, 31 studies met inclusion criteria. Twenty-nine studies with 2217 pregnant women were included for meta-analysis. Pregnancy yoga interventions reduced anxiety (SMD: -0.91; 95% CI: - 1.49 to - 0.33; p = 0.002), depression (SMD: -0.47; 95% CI: - 0.9 to - 0.04, P = 0.03) and perceived stress (SMD: -1.03; 95% CI: - 1.55 to - 0.52; p < 0.001). Yoga interventions also reduced duration of labour (MD = - 117.75; 95% CI - 153.80 to - 81.71, p < 0.001) and, increased odds of normal vaginal birth (OR 2.58; 95% CI 1.46-4.56, p < 0.001) and tolerance for pain. The quality of evidence (GRADE criteria) was low to very low for all outcomes. Twelve or more yoga sessions delivered weekly/bi-weekly had a statistically significant impact on mode of birth, while 12 or more yoga sessions of long duration (> 60 min) had a statistically significant impact on perceived stress.The evidence highlights positive effects of pregnancy yoga on anxiety, depression, perceived stress, mode of birth and duration of labour.PROSPERO, CRD42019119916. Registered on 11th January 2019.
TL;DR: The authors used 16S rRNA gene-based metagenomic analysis to investigate the impact of crop rotation and soil cultivation methods (no-till or tillage) on rhizosphere bacterial diversity and composition in eight crop fields in Arkansas.
Abstract: The rhizomicrobiome is composed of microbes that live in association with plant roots. From nutrient cycling to carbon sequestration, soil microorganisms have provided a solid base for natural and agricultural ecosystems to function. The relationship between plant roots and soil microorganisms is especially relevant in food staples such as rice (Oryza sativa L.), as the various properties of these microbes can influence crop yield and plant health, thereby affecting a major portion of the food supply for an ever-growing world population. In this study, we used 16S rRNA gene-based metagenomic analysis to investigate the impact of crop rotation and soil cultivation methods (no-till or tillage) on rhizosphere bacterial diversity and composition in eight crop fields in Arkansas. Illumina MiSeq sequencing revealed 56 Phyla, with four major Phyla: Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes. Soil microbial communities in the samples studied were phylogenetically diverse but with a stable community structure. Crop rotation and tillage did not significantly affect bacterial diversity.
TL;DR: In this paper , an ERF transcription factor HcERF4 was isolated and characterized from kenaf, and its expression profile was investigated by real-time PCR analysis in different tissues and under salt as well as drought stress condition.
Abstract: Ethylene response factors (ERF) are members of the APETALA2/ERF transcription factor family, and they play an important role in plant growth, development, and response to various environmental stresses. In this study, an ERF transcription factor HcERF4 was isolated and characterized from kenaf. The results showed HcERF4 contained an open reading frame of 702 bp, which comprised of single AP2 domain. Subcellular localization analysis revealed that the HcERF4 gene was localized in the nucleus and cytoplasm. Transactivation assays in yeast demonstrated that HcERF4 functions as a transcriptional activator. Its expression profile was investigated by real-time PCR analysis in different tissues and under salt as well as drought stress condition. The result revealed that HcERF4 could be markedly induced by salt and drought in a time and concentration dependent manner. Moreover, silencing of HcERF4 by using the VIGS technique, caused a significant growth inhibition under salt or drought stress condition, with lower plant height, stem diameter, and fresh weight, indicating HcERF4 plays key roles response abiotic stress. In addition, physiological index analyses showed that the contents of MDA, O2−, H2O2, and free proline significantly increased, while the activities of antioxidant enzymes were significantly restrained in HcERF4 silenced plants. Furthermore, the expression level of eight important genes involved in plant growth regulation, including HcERF3, HcNAC29, HcSOD, HcP5CS, HcbZIP43, HcWRKY31, HcMYB44, and HcCBP25 were investigated, and the result showed that all eight genes were highly expressed in the leaves of the wild kenaf, but were significantly downregulated in the leaves of the VIGS kenaf plants under drought and salt stress conditions; Consequently, the present results indicate HcERF4 plays a positive role in regulating salt and drought stress in kenaf. HcERF4 transcription factor modulates drought and salinity stress in kenaf (Hibiscus cannabinus L.).