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Recent advances in glucose-responsive insulin delivery systems:novel hydrogels and future applications

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Regenerative Biomaterials 2022年第1期9卷 1037-1045页

作者： Avha R.Mohanty Akhila Ravikumar Nicholas A.Peppas McKetta Department of Chemical Engineering The University of Texas at Austin200 E Dean Keeton StAustinTX 78712USA Institute for Biomaterials Drug Deliveryand Regenerative MedicineThe University of Texas at Austin107WDean Keeton StAustinTX 78712USA Department of Biomedical Engineering The University of Texas at Austin107WDean Keeton StAustinTX 78712USA Division of Molecular Pharmaceutics and Drug Delivery College of PharmacyThe University of Texas at Austin2409 University AveAustinTX 78712USA Department of Surgery and Perioperative Care Dell Medical SchoolThe University of Texas at Austin1501 Red River StAustinTX 78712USA Department of Pediatrics Dell Medical SchoolThe University of Texas at Austin1501 Red River StAustinTX 78712USA

Over the past several decades,there have been major advancements in the field of glucose sensing and insulin delivery for the treatment of type I diabetes *** introduction of closed-loop insulin delivery systems that deliver insulin in response to specific levels of glucose in the blood has shifted significantly the research in this *** systems consist of encapsulated glucose-sensitive components such as glucose oxidase or phenylboronic acid in hydrogels,microgels or *** our previous evaluation of these systems in a contribution in 2004,new systems have been *** improvements in key issues,such as consistent insulin delivery over an extended period of time have been *** this contribution,we discuss recent advancements over the last 5 years and present persisting issues in these technologies that must be overcome in order for these systems to be applicable in patients.

关键词： insulin delivery glucose control hydrogels glucose oxidase diabetes

NASICON solid electrolyte coated by indium film for all-solid-state Li-metal batteries

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Tungsten 2022年第4期4卷 316-322页

作者： Yi-Jie Liu Ru-Yi Fang David Mitlin Materials Science and Engineering Program and texas Materials Institute The University of Texas at AustinAustinTX78712USA

The application of all-solid-state Li-metal batteries with solid oxide electrolytes is hindered by interfacial issues,especially the solid electrolyte/Li-metal *** work introduced a uniform indium film layer on the surface of Na^(+)super ionic conductor(NASICON)solid electrolyte Li_(1.5)Al_(0.5)Ge_(1.5)P_(3)O_(12)(LAGP),which promotes the intimate contact between Li metal and solid electrolyte and hinders the side reactions at the *** impedance spectra show that the battery with coated solid electrolyte presents a smaller interfacial resistance and maintains stability after a long cycling *** contrast,the baseline battery with a pure LAGP pellet shows a contact loss after cycling with the vibration of interfacial *** Li symmetric cells with indium-modified solid electrolyte present stable cycling behavior over 400 h at 0.1 and 0.2 mA·cm^(−2).The all-solid-state Li-metal batteries with a Li anode,indium coating LAGP and two kinds of cathodes,namely carbon nanotubes(CNTs)and LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811),are prepared and *** CNTs cathode for Li-O2 and Li-air batteries has a higher specific capacity than traditional Li-ion battery *** Li-NCM811 batteries deliver an initial Coulombic efficiency of about 75%,with 82%capacity retention after 20 cycles.

关键词： All-solid-state batteries Solid electrolyte Li1.5Al0.5Ge1.5P3O12 Li-metal anode Interfacial chemistry

Opto-thermoelectric microswimmers

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Light(Science & Applications) 2020年第1期9卷 674-685页

作者： Xiaolei Peng Zhihan Chen Pavana Siddhartha Kollipara Yaoran Liu Jie Fang Linhan Lin Yuebing Zheng Materials Science&Engineering Program and texas Materials Institute The University of Texas at AustinAustinTX 78712USA Walker Department of Mechanical Engineering The University of Texas at AustinAustinTX 78712USA State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084People’s Republic of China

Inspired by the“run-and-tumble”behaviours of Escherichia coli(***)cells,we develop opto-thermoelectric *** microswimmers are based on dielectric-Au Janus particles driven by a self-sustained electrical field that arises from the asymmetric optothermal response of the *** illumination by a defocused laser beam,the Janus particles exhibit an optically generated temperature gradient along the particle surfaces,leading to an opto-thermoelectrical field that propels the *** further discover that the swimming direction is determined by the particle *** enable navigation of the swimmers,we propose a new optomechanical approach to drive the in-plane rotation of Janus particles under a temperature-gradient-induced electrical field using a focused laser *** the rotation laser beam allows us to position the particles at any desired orientation and thus to actively control the swimming direction with high *** incorporating dark-field optical imaging and a feedback control algorithm,we achieve automated propelling and navigation of the *** optothermoelectric microswimmers could find applications in the study of opto-thermoelectrical coupling in dynamic colloidal systems,active matter,biomedical sensing,and targeted drug delivery.

关键词： rotation illumination beam

Strategies for improving the storage performance of silicon-based anodes in lithium-ion batteries

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Nano Research 2019年第8期12卷 1739-1749页

作者： Wei Tao Ping Wang Ya You Kyusung Park Cao-Yu Wang Yong-Ke Li Fei-Fei Cao Sen Xin College of Science Huazhong Agricultural UniversityWuhan 430070China Department of Mechanical Engineering The university of texas at austin AustinTX 78712USA

Silicon has attracted much attention as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and rich resource abundance. However, the practical battery use of Si is challenged by its low conductivity and drastic volume variation during the Li uptake/release process. Tremendous efforts have been made on shrinking the particle size of Si into nanoscale so that the volume variation could be accommodated. However, the bare nano-Si material would still pulverize upon (de)lithiation. Moreover, it shows an excessive surface area to invite unlimited growth of solid electrolyte interface that hinders the transportation of charge carriers, and an increased interparticle resistance. As a result, the Si nanoparticles gradually lose their electrical contact during the cycling process, which accounts for poor thermodynamic stability and sluggish kinetics of the anode reaction versus Li. To address these problems and improve the Li storage performance of nano-Si anode, proper structural design should be applied on the Si anode. In this perspective, we will briefly review some strategies for improving the electrochemistry versus Li of nano-Si materials and their derivatives, and show opinions on the optimal design of nanostructured Si anode for advanced LIBs.

关键词： silicon anode lithium-ion battery silicon/carbon composites silicon/non-carbon composites silicon oxide

New Insights on Energy Conserved Planar Motion

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Computer Modeling in Engineering & Sciences 2016年第2期111卷 119-127页

作者： Maruthi R.Akella Sofokli Cakalli Department of Aerospace Engineering and Engineering Mechanics The University of Texas at AustinAustinTX 78712USA.

The planar motion of a particle within an arbitrary potential field is *** particle is additionally subject to an external force wherein the applied thrust-acceleration is constrained to remain normal to the velocity *** system is thus non-conservative but since the thrust force is non-working,the total energy is a conserved *** this setting,a major result of fundamental importance is established in this paper:that the flight direction angle(more precisely,the sine of the angle between the position and velocity vectors)is shown to always satisfy a linear first-order differential equation with variable coefficients that depend upon the underlying potential *** a consequence,an analytical solution for the flight direction angle can be obtained directly in terms of the particle’s distance from the center of the field for a significant number of special cases for the potential *** the case of J2 perturbed spacecraft motion within equatorial orbits,the problem is reduced to that of solving an incomplete elliptic *** important implication of the main result established here is that motion problems subject to velocity-normal thrusting can always be reduced to the study of equivalent single degree-of-freedom conservative systems with an effective potential *** paper concludes with various examples of both academic and practical interest including the study of bounded two-body Keplerian orbits and hodograph interpretetions.

关键词： Energy conserved spacecraft motion flight direction angle velocitynormal thrusting effective potential hodograph interpretation

Mo2C@3D ultrathin macroporous carbon realizing efficient and stable nitrogen fixation

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Science China Chemistry 2020年第11期63卷 1570-1577页

作者： Zhiwei Fang Desiree Fernandez Nana Wang Zhongchao Bai Guihua Yu Materials Science and Engineering Program Texas Materials InstituteThe University of Texas at AustinAustinTexas 78712United States Institute for Superconducting and Electronic Materials University of WollongongInnovation CampusWollongongNew South Wales 2500Australia

Ammonia is a key feedstock of fertilizers for farming and convenient hydrogen carrier as an emerging clean fuel,but industrial ammonium production process,Haber-Bosch reaction,is an energy-intensive process,consuming 1%–2%of global energy and producing 3%global *** nitrogen reduction reaction(NRR)is one of the most promising routes to realize highly efficient NH3 production under ambient ***,up to now,few precious-metal-free electrocatalysts with desirable catalytic performance have been *** this work,Mo2C nanodots anchored on three-dimensional ultrathin macroporous carbon(Mo2C@3DUM-C)framework is developed toward significantly enhanced nitrogen reduction *** to the special structural design of 3D ultrathin macroporous carbon and highly active and stable Mo2C toward N2 electrochemical reduction,the Mo2C@3DUM-C framework exhibits a high Faradaic efficiency of 9.5%for NH3 production at−0.20 V and the yield rate reaches 30.4µg h−1 mgMo2C−*** electrochemical characterizations reveal the enhanced electron transfer and increased electrochemical surface area in the 3D macroporous carbon ***,the Mo2C@3DUM-C electrocatalysts hold high catalytic stability after long-term NRR *** temperature-dependent yield rate of NH3 demonstrates that the activation energy of nitrogen reduction on the employed catalyst was calculated to be 28.1 kJ mol−*** proposed earth-abundant Mo2C@3DUM-C demonstrates an alternative insight into developing efficient and stable nitrogen fixation catalysts in acids as alternatives to noble metal catalysts.

关键词： electrocatalyst nitrogen fixation nanoparticles molybdenum macroporous carbon

Representative Elementary Volume(REV) in Spatio-Temporal Domain： A Method to Find REVfor Dynamic Pores

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Journal of Earth Science 2017年第2期28卷 391-403页

作者： Harpreet Singh The university of texas at austin Austin TX USA National Energy Technology Laboratory Morgantown WV USA

One of the potential risks associated with subsurface storage of CO_2 is the seepage of CO_2 through existing faults and fractures. There have been a number of studies devoted to this topic. Some of these studies show that geochemistry, especially mineralization, plays an important role in rendering the faults as conduits for CO_2 movement while others show that mineralization due to CO_2 injection can result in seep migration and flow diversion. Therefore, understanding the changes in reservoir properties due to pore alterations is important to ensure safe long term CO_2 storage in the subsurface. We study the changes in the Representative Elementary Volume（REV） of a rock due to reactive kinetics over a time, using a statistical approach and pore-scale CO_2-rock *** goal of this study is to obtain the REV of a rock property that accounts for pore-scale changes over time due to reactive kinetics, and we call this as spatiotemporal REV. Scale-up results suggest that the REV changes with time when CO_2-rock interaction is considered. It is hypothesized that the alteration in pore structure introduces more heterogeneity in the rock, and because of this the magnitude of REV increases. It is possible that these noticeable changes in REV at pore-scale may have an impact when analyzed at the reservoir scale.

关键词： reactive dynamics reaction rate constant CO_2 scale-up upscaling geostatistics

Harnessing the flatbandλ-Ti_(3)O_(5):A breakthrough in solar steam generation

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Science China Materials 2023年第11期66卷 4515-4516页

作者： Chuxin Lei Guihua Yu Materials Science and Engineering Program and Walker Department of Mechanical Engineering The University of Texas at AustinAustinTX 78712USA

As global population rises,accompanied by escalating environmental pollution and climate change,numerous countries find themselves grappling with an acute scarcity of natural freshwater resources^([1]).Seawater desalination presents a compelling solution to this looming crisis,especially considering the oceans are Earth’s largest water reservoir^([2]).

关键词： reservoir Earth breakthrough

A Survey of Voltage-Controlled-Oscillator-Based ?∑ ADCs

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Tsinghua Science and Technology 2022年第3期27卷 472-480页

作者： Yi Zhong Nan Sun Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Department of Electrical and Computer Engineering The University of Texas at AustinAustinTX 78712USA

The benefits of technology scaling have fueled interest in realizing time-domain oversampling(?∑) of Analog-to-Digital Converters(ADCs). Voltage-Controlled Oscillators(VCO) are increasingly used to design ?∑ADCs because of their simplicity, high digitization, and low-voltage tolerance, making them a promising candidate to replace the classical Operational Transconductance Amplifier(OTA) in ?∑ ADC design. This work aims to provide a summary of the fully VCO-based ?∑ ADCs that are highly digital and scaling-friendly. This work presents a review of first-order and high-order VCO-based ?∑ ADCs with several techniques and architectures to mitigate the nonidealities introduced by VCO, achieving outstanding power efficiency. The contributions and drawbacks of these techniques and architectures are also discussed.

关键词： Voltage-Controlled Oscillator(VCO) Analog-to-Digital Converter(ADC) oversampling(?∑)ADC time-domain signal processing VCO-based?∑ADC