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Reduced texaphyrin:A ratiometric optical sensor for heavy metals in aqueous solution

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Frontiers of Chemical Science and Engineering 2020年第1期14卷 19-27页

作者： Harrison D.Root Gregory Thiabaud Jonathan L.Sessler Department of Chemistry The University of Texas at AustinAustinTX 78712-1224USA

We report here a water-soluble metal cation sensor system based on the as-prepared or reduced form of an expanded porphyrin,*** metal complexation,a change in the redox state of the ligand occurs that is accompanied by a color change from red to *** long employed for synthesis in organic media,we have now found that this complexation-driven redox behavior may be used to achieve the naked eye detectable colorimetric sensing of several number of less-common metal ions in aqueous *** to In(Ⅲ),Hg(Ⅱ),Cd(Ⅱ),Mn(Ⅱ),Bi(Ⅲ),Co(Ⅱ),and Pb(Ⅱ)cations leads to a colorimetric response within 10 *** process is selective for Hg(Ⅱ)under conditions of competitive ***,among the subset of responseproducing cations,In(Ⅲ)proved unique in giving rise to a ratiometric change in the ligand-based fluorescence features,including an overall increase in *** cation selectivity observed in aqueous media stands in contrast to what is seen in organic solvents,where a wide range of texaphyrin metal complexes may be *** formation of metal cation complexes under the present aqueous conditions was confirmed by reversed phase highperformance liquid chromatography,ultra-violet-visible absorption and fluorescence spectroscopies,and highresolution mass spectrometry.

关键词： texaphyrin fluorescent sensor ion-sensing indium mercury

Surface hydrolysis-mediated PEGylation of poly(N-isopropyl acrylamide)based nanogels

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Regenerative Biomaterials 2017年第5期4卷 281-287页

作者： Jonathan T.Peters Stanley Verghese Deepak Subramanian Nicholas A.Peppas McKetta Department of Chemical Engineering The University of Texas at AustinAustinTXUSA Institute for Biomaterials Drug Deliveryand Regenerative MedicineThe University of Texas at AustinAustinTXUSA Department of Biomedical Engineering The University of Texas at AustinAustinTXUSA Department of Pediatrics and Department of Surgery and Perioperative CareDell Medical SchoolThe University of Texas at AustinAustinTXUSA Division of Pharmaceutics College of PharmacyThe University of Texas at AustinAustinTXUSA

In this work,poly(N-isopropyl acrylamide-co-acrylamide)[P(NIPAAm-co-AAm)]nanogels were modified by hydrolysis above the lower critical solution temperature(LCST)to localize carboxylic acid functional groups at the surface(surface hydrolysis).PNIPAAm copolymerized with 15%and 20%nominal AAm in the feed were prepared and compared to equivalent hydrogels with acrylic *** effect and extent of surface hydrolysis was confirmed by potentiometric titration and zeta *** surface modified nanogels were then modified with primary amine functionalized PEG *** hydrolysis-mediated PEGylation had little effect on the swelling response of the nanogels,while also preventing adsorption of model proteins in physiological relevant *** both 15%and 20%AAm gels both decreased protein adsorption,only the 20%AAm gels resulted in fully preventing protein *** results presented here point to surface hydrolysis as a new route to passivate nanogels for use in vivo.

关键词： PNIPMAAm hydrogels PEG passivation

A high‑throughput three‑dimensional cell culture platform for drug screening

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Bio-Design and Manufacturing 2020年第1期3卷 40-47页

作者： Jingyu Ock Wei Li Department of Mechanical Engineering The University of Texas at AustinAustinTX 78712USA

Traditional two-dimensional(2D)cell cultures lack the extracellular matrix(ECM)-like structure or dynamic fluidic microenvironment for cells to maintain in vivo ***-dimensional(3D)tissue scaffolds,on the other hand,could provide the ECM-like microenvironment for cells to reformulate into tissue or organoids that are highly useful for in vitro drug *** this study,a high-throughput two-chamber 3D microscale tissue model platform is *** scaffolds are selectively foamed on a commercially available compact disk using *** of cell culture medium is achieved with centrifugal force-driven diffusion by disk *** studies were conducted on the fabrication process under various gas saturation and laser power *** cultures were performed with two types of human cell lines:M059K and *** is shown that the structure of microscale porous scaffolds can be controlled with laser foaming parameters and that coating with polydopamine these scaffolds are inducive for cell attachment and aggregation,forming a 3D *** many such two-chamber models fabricated on a single CD and perfusion driven by the centrifugal force from rotation,the proposed platform provides a simple solution to the high-cost and lengthy drug development process with a high-throughput and physiologically more relevant tissue model system.

关键词： High-throughput screening Three-dimensional tissue model Drug screening Centrifugal force-driven diffusion Laser foaming

Multidirectional Gaussian Mixture Models for Nonlinear Uncertainty Propagation

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Computer Modeling in Engineering & Sciences 2016年第1期111卷 83-117页

作者： V.Vittaldev R.P.Russell Ph.D.Candidate The University of Texas at AustinAustinTXUSA. Associate Professor The University of Texas at AustinAustinTXUSA.

Monte Carlo simulations are an accurate but computationally expensive procedure for approximating the resultant non-Gaussian probability density function(PDF)after propagation of an initial Gaussian PDF through a nonlinear *** splitting libraries for Gaussian Mixture Models(GMMs)exist with up to five elements in the *** number of splits are extended in the present work by generating three homoscedastic univariate splitting libraries with up to 39 *** GMMs are typically handled with splits along a single ***,we generate a regular multidirectional grid over the initial multivariate Gaussian distribution by recursively applying the splitting library along multiple *** splitting direction is arbitrary and no longer limited to directions parallel to the columns of the square-root of the covariance matrix.A second order Stirling’s interpolation of the nonlinear function evaluated at the mean of the initial Gaussian distribution is used to quantify nonlinearity along candidate splitting *** directions with the highest nonlinearity benefit most from *** Multidirectional GMM(MGMM)has applications for uncertainty quantification with computationally intensive nonlinear *** variable number of splits in each direction allows for a spectrum of models in the accuracy versus compute time design space,filling the gap between expensive Monte Carlos and fast linearized *** multidirectional method is demonstrated with four test cases,including an orbit uncertainty propagation case,to illustrate the benefit of splitting along multiple directions and of ranking the splitting directions.

关键词： Uncertainty Quantification Gaussian Mixture Models

Role of peripheral amyloid-β aggregates in Alzheimer’s disease: mechanistic, diagnostic, and therapeutic implications

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Neural Regeneration Research 2025年第4期20卷 1087-1089页

作者： Nazaret Gamez Rodrigo Morales Department of Neurology The University of Texas Health Science Center at HoustonHoustonTXUSA Centro Integrativo de Biologia y Quimica Aplicada(CIBQA) Universidad Bernardo O’HigginsSantiagoChile

Compelling evidence demonstrates that the levels of peripheral amyloid-β(Aβ)fluctuate in Alzheimer’s disease(AD)***,Aβdeposits have been identified in peripheral ***,the relevance of peripheral Aβ(misfolded or not)in pathological situations,and the temporal appearance of these pathological fluctuations,are not well *** presence of misfolded Aβin peripheral compartments raises concerns on potential inter-individual transmissions considering the well-reported prion-like properties of this disease-associated *** latter is supported by multiple reports demonstrating that Aβmisfolding can be transmitted between humans and experimental animals through multiple routes of *** this mini-review,we discuss the potential implications of peripheral,disease-associated Aβin disease mechanisms,as well as in diagnostic and therapeutic approaches.

关键词： therapeutic amyloid latter

Metamaterials and plasmonics: From nanoparticles to nanoantenna arrays, metasurfaces, and metamaterials

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Chinese Physics B 2014年第4期23卷 64-75页

作者： Francesco Monticone Andrea Alù Department of Electrical and Computer Engineering The University of Texas at Austin 1 University Station C0803Austin Texas 78712 USA

The rise of plasmonic metamaterials in recent years has unveiled the possibility of revolutionizing the entire field of optics and photonics, challenging well-established technological limitations and paving the way to innovations at an unprecedented level To capitalize the disruptive potential of this rising field of science and technology, it is important to be able to combine the richness of optical phenomena enabled by nanoplasmonics in order to realize metamaterial components, devices, and systems of increasing complexity. Here, we review a few recent research directions in the field of plasmonic metamaterials, which may foster further advancements in this research area. We will discuss the anomalous scattering features enabled by plasmonic nanoparticles and nanoclusters, and show how they may represent the fundamental building blocks of complex nanophotonic architectures. Building on these concepts, advanced components can be designed and operated, such as optical nanoantennas and nanoantenna arrays, which, in turn, may be at the basis of metasurface devices and complex systems. Following this path, from basic phenomena to advanced functionalities, the field of plasmonic metamaterials offers the promise of an important scientific and technological impact, with applications spanning from medical diagnostics to clean energy and information processing.

关键词： plasmonics metamaterials nanoparticles scattering

A SURVEY OF STACKELBERG DIFFERENTIAL GAME MODELS IN SUPPLY AND MARKETING CHANNELS

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Journal of Systems Science and Systems Engineering 2007年第4期16卷 385-413页

作者： Xiuli HE Ashutosh PRASAD Suresh P. SETHI Genaro J. GUTIERREZ School of Management The University of Texas at Dallas Richardson TX 75080 McCombs School of Business The University of Texas at Austin Austin TX 78731

Stackelberg differential game models have been used to study sequential decision making in noncooperative games in diverse fields. In this paper, we survey recent applications of Stackelberg differential game models to the supply chain management and marketing channels literatures. A common feature of these applications is the specification of the game structure： a decentralized channel composed of a manufacturer and independent retailers, and a sequential decision procedure with demand and supply dynamics and coordination issues. In supply chain management, Stackelberg differential games have been used to investigate inventory issues, wholesale and retail pricing strategies, and outsourcing in dynamic environments. The underlying demand typically has growth dynamics or seasonal variation. In marketing, Stackelberg differential games have been used to model cooperative advertising programs, store brand and national brand advertising strategies, shelf space allocation, and pricing and advertising decisions. The demand dynamics are usually extensions of the classical advertising capital models or sales-advertising response models. We begin by explaining the Stackelberg differential game solution methodology and then provide a description of the models and results reported in the literature.

关键词： Stackelberg differential games supply chain management marketing channels open-loop equilibria feedback policies channel coordination optimal control

Survival of rat sciatic nerve segments preserved in storage solutions ex vivo assessed by novel electrophysiological and morphological criteria

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Neural Regeneration Research 2023年第9期18卷 2082-2088页

作者： Liwen Zhou Monzer Alatrach Ted Zhao Paul Oliphint George D.Bittner Department of Neuroscience University of Texas at AustinAustinTXUSA

Most organ or tissue allografts with viable cells are sto red in solutions ex vivo for hours to seve ral *** allografts then require rapid host revascula rization upon transplantation to maintain donor-cell functions(e.g.,cardiac muscle contra ctions,hepatic secretions).In contrast,peripheral nerve allografts stored ex vivo do not require revascularization to act as scaffolds to guide outgrowth by host axons at 1-2 mm/d,likely aided by viable donor Schwann *** current storage solutions and protocols,axons in all these donor orga n/tissue/nerve transplants are expected to rapidly become non-viable due to Wallerian degeneration within ***,ex vivo storage solutions have not been assessed for preserving normal axonal functions,i.e.,conducting action potentials or maintaining myelin *** hypothesized that most or all organ storage solutions would maintain axonal *** examined several common organ/tissue storage solutions(university of Wisconsin Cold Storage Solution,Normosol-R,Normal Saline,and La ctated Ringe rs) for axonal viability in rat sciatic nerves ex vivo as assessed by maintaining:(1) conduction of artificially-induced compound action potentials;and(2) axonal and myelin morphology in a novel assay *** ten diffe rent storage solution conditions for peripheral nerves with viable axons(PNVAs) diffe red in their solution composition,osmolarity(250-318 mOsm),temperature(4℃ vs.25℃),and presence of *** action potentials and axonal morphology in PNVAs were best maintained for up to 9 days ex vivo in calcium-free hypotonic diluted(250 mOsm) Normosol-R(dNR) at 4℃.Surprisingly,compound action potentials were maintained for only 1-2 days in UW and NS at 4℃,a much shorter duration than PNVAs maintained in 4℃ dNR(9 days) or even in 25℃ dNR(5 days).Viable axons in peripheral nerve allografts are critical for successful polyethylene glycol(PEG)-fusion of viable proximal and distal ends of host axons with viable donor a

关键词： axonal morphometrics axonal viability calcium osmolarity peripheral nerve grafts peripheral nerve injury temperature tissue storage solutions tonicity Wallerian degeneration

Design and applications of lattice plasmon resonances

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Nano Research 2018年第9期11卷 4423-4440页

作者： Bharath Bangalore Rajeeva Linhan Lin Yuebing Zheng Materials Science and Engineering Program Department of Mechanical Engineering The University of Texas at Austin Austin Texas78712 USA

With their unique optical properties associated with the excitation of surface plasmons, metal nanoparticles （NPs） have been used in optical sensors and devices. The organization of these NPs into arrays can induce coupling effects to engineer new optical responses. In particular, lattice plasmon resonances （LPRs）, which arise from coherent interactions and coupling among NPs in periodic arrays, have shown great promise for realizing narrow linewidths, angle-dependent dispersions, and high wavelength tunability of optical spectra. By engineering the materials, shapes, sizes, and spatial arrangements of NPs within arrays, one can tune the LPR-based spectral responses and electromagnetic field distributions to deliver a multitude of improvements, including a high figure-of-merit, superior light-matter interaction, and multiband operation. In this review, we discuss recent progress in designing and applying new metal nanostructures for LPR-based applications. We conclude this review with our perspective on the future opportunities and challenges of LPR-based devices.

关键词： plasmonics,lattice plasmon resonance,nanoparticle array coupling,sensors