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Development and characterization of a microfluidic glucose sensing system based on an enzymatic microreactor and chemiluminescence detection

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Science china chemistry 2012年第4期55卷 515-523页

作者： MOON b.-U. de VRIES M.G. we.te.ink b.h.c. VERPOORte E. biomonitoring and Sensoring Department of Pharmacy University of Groningen Antonius Deusinglaan 1 9713AV Groningen The Netherlands Pharmaceutical Analysis Department of Pharmacy University of Groningen Antonius Deusinglaan 1 9713AV Groningen The Netherlands brains-on-Line PO Box 4030 9713AV Groningen The Netherlands

chemiluminescence detection was developed as an alternative to amperometric detection for glucose analysis in a portable, microfluidicsbased continuous glucose monitoring system. Amperometric detection allows easy determination of hydrogen peroxide, a product of the glucose oxidasecatalyzed reaction of glucose with oxygen, by oxidation at a microelectrode. however, （micro）electrodes in direct contact with physiological sample are subject to electrode fouling, which leads to signal drift, decreased reproducibility and shortened detector lifetimes. Moreover, there are a few species present in the body （e.g. ascorbic acid, uric acid） which can undergo oxidation at the same applied potential as hydrogen peroxide. These species can thus inter- fere with the glucose measurement, reducing detection specificity. The rationale for exploring chemiluminescence as opposed to amperometric detection is thus to attempt to improve the lifetime and reproducibility of glucose analysis for monitoring purposes, while reducing interference caused by other chemicals in the body. The study reported here represents a first step in this direction, namely the realization of a microfluidic device with integrated silicon photodiode for chemiluminescence detection of glucose. This microflow device uses a chaotic mixing approach to perform enzymatic conversion of glucose, followed by reaction of the hydrogen peroxide produced with luminol to produce light at 425 nm. The chemil reaction is catalyzed by horseradish peroxidase in the presence of iodophenol. The performance of the fabricated chip was characterized to establish optimal reaction conditions with respect to sample and reagent flow rates, ph, and concentrations. A linear calibra- tion curve was obtained for current response as a function of glucose concentration in the clinically relevant range between 2 and 10 mM, with a sensitivity of 39 pA/mM （R = 0.9963, one device, n = 3） and a limit of detection of 230 ktM （S/N - 3）.

关键词： microfluidic chip – glucose sensing system – enzymatic microreactor – chemiluminescence – chaotic mixing

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Acquired sensorineural hearing loss,oxidative stress,and microRNAs

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Neural Regeneration Research 2025年第9期20卷 2513-2519页

作者： Desmond A.Nunez Ru c.Guo Division of Otolaryngology–head&Neck Surgery Department of SurgeryFaculty of MedicineThe University of British ColumbiaVancouverBCCanada Division of Otolaryngology–head&Neck Surgery Gordon&Leslie Diamond Health Care CentreVancouver General HospitalVancouverBCCanada Faculty of Medicine–The University of british columbia VancouverBCCanada

hearing loss is the third leading cause of human ***-related hearing loss,one type of acquired sensorineural hearing loss,is largely responsible for this escalating global health ***-induced,ototoxic,and idiopathic sudden sensorineural are other less common types of acquired hearing *** etiology of these conditions is complex and multi-fa ctorial involving an interplay of genetic and environmental *** stress has recently been proposed as a likely linking cause in most types of acquired sensorineural hearing *** non-coding RNA sequences known as microRNAs(miRNAs)have increasingly been shown to play a role in cellular hypoxia and oxidative stress responses including promoting an apoptotic *** hair cell death is a central histopathological finding in sensorineural hearing *** these cells do not regenerate in humans,it underlies the irreversibility of human age-related hearing *** EMbASE,Ovid MEDLINE,web of Science core collection,and *** databases over the period August 1,2018 to July 31,2023 were searched with"hearing loss,""hypoxamiRs,""hypoxia,""microRNAs,""ischemia,"and"oxidative stress"text words for English language primary study publications or registered clinical *** red clinical trials known to the senior author we re also assessed.A total of 222studies were thus *** excluding duplicates,editorials,retra ctions,secondary research studies,and non-English language articles,39 primary studies and clinical trials underwent full-text *** resulted in 11 animal,in vitro,and/or human subject journal articles and 8 registered clinical trial database entries which form the basis of this narrative *** miR-34a and miR-29b levels increase with age in *** miRNAs were demonstrated in human neuroblastoma and murine cochlear cell lines to target Sirtuin 1/peroxisome proliferato r-activated receptor gamma coactivator-1-alpha(SIRT1/P Gc-1α),SIRT

关键词： hearing loss hypoxia microRNAs oxidative stress sensorineural

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Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

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Neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： carina hromada Patrick heimel Markus Kerbl LászlóGál Sylvia Nürnberger barbara Schaedl James Ferguson Nicole Swiadek Xavier Monforte Johannes c.heinzel Antal Nógrádi Andreas h.teuschl-Woller David hercher Department Life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian cluster for Tissue Regeneration ViennaAustria Ludwig boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGcs). however, the use of tNGcs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGc would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGcs and compared the various features of these improved silk^(+) tNGcs with the tubes without holes(silk^(–) tNGcs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGcs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGcs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGcs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGcs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

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combustion synthesis, characterization and luminescence properties of barium aluminate phosphor

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Journal of Rare Earths 2014年第9期32卷 806-811页

作者： A.h. Wako F.b Dejene h.c Swart Department of Physics University of the Free State (Qwaqwa Campus) Department of Physics University of the Free State

The blue-green emitting Eu2＋ and Nd3＋ doped polycrystalline barium aluminate （baAI204：Eu2＋,Nd3＋） phosphor, was prepared by a solution-combustion method at 500 ℃without a post-annealing process. The characteristic variation in the structural and luminescence properties of the as-prepared samples was evaluated with regards to a change in the ba/A1 molar ratio from 0.1：1 to 1.4：1. The morphologies and the phase structures of the products were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （teM）, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）, while the optical properties were investigated using ultra-violet （UV） and photoluminescence （PL） spectroscopy, respectively. The XRD and teM results revealed that the average crystallite size of the baAl2O4：Eu2＋,Nd3＋ phosphor was about 70 urn. The broad-band UV-excited luminescence of the phosphors was observed at 2max=500 um due to transitions from the 4f^65d1 to the 4f7 configuration of the Eu2＋ ion. The PL results indicated that the main peaks in the emission and excitation spectrum of phosphor particles slightly shifted to the short wavelength due to the changes in the crystal field due to the structure changes caused by the variation in the quantity of the ba ions in the host lattice.

关键词： baAl2O4:Eu2+,Nd3+ persistence luminescence Eu2+ and Nd3+ doping rare earths

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controlling Excitation Inversion of a cooper Pair box Interacting with a Nanomechanical Resonator

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chinese Physics Letters 2012年第8期29卷 20-24页

作者： c.Valverde h.c.b.de Oliveira A.T.Avelar b.baseia Instituto de Química Universidade de Brasília70919-970BrasíliaDFBrazil Universidade Estadual de Goiás Rod.BR 15375132-903 AnápolisGOBrazil Universidade Paulista Rod.BR 153km 774845-090 GoianiaGOBrazil Instituto de Física Universidade Federal de Goiás74001-970 GoianiaGOBrazil

we investigate the action of time-dependent detunings upon the excitation inversion of a cooper pair box interacting with a nanomechanical *** method employs the Jaynes–cummings model with damping,assuming different decay rates of the cooper pair box and various fixed and time-dependent *** is shown that,when the presence of damping plus constant detunings destroys the collapse/revival effects,convenient choices of time-dependent detunings allow one to reconstruct such events in a perfect *** is also shown that the mean excitation of the nanomechanical resonator is more robust against damping of the cooper pair box for convenient values of time-dependent detunings.

关键词： cooper tuning excitation

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Synthesis and characterization of caAl_xO_y:Eu^(2+) phosphors prepared using solution-combustion method

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Journal of Rare Earths 2010年第S1期28卷 272-276页

作者： F.b.Dejene D.b.bem h.c.Swart Department of Physics University of the Free State(Qwaqwa Campus)Private Bag X13Phuthaditjhaba9866South Africa Department of Physics University of the Free StateP.O.Box 339Bloemfontein9300South Africa

Europium-doped calcium aluminate(caAlxOy:Eu2+) phosphors were obtained at low temperatures(500 oc) by the solution-combustion of corresponding metal nitrate-urea solution *** particle size and morphology and the structural and luminescent properties of the as-synthesized phosphors were examined by means of scanning electron microscopy(SEM),X-ray diffraction(XRD),Auger spectroscopy,transmission electron spectroscopy(teM) and photoluminescence(PL).It was found that the ca:Al molar ratios showed greatly influence not only on the particle size and morphology,but also on their PL spectra and *** the ca:Al molar ratios increasing from 6:100 to 26:100,the structure of as-synthesized phosphor changed from caAl12O19 to monoclinic caAl2O4 and the dominant emitting light from red to blue,implying that the oxidation state of doped europium ions changed from trivalent to divalent due to the structure variation of host lattice.A blue phosphor with almost pure phase can be easily prepared by solution combustion method with suitable ca:Al molar ratio.

关键词： caAlxOy:Eu2+ solution-combustion molar ratio structure luminescence rare earths

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Simulating canopy stomatal conductance of winter wheat and its distribution using remote sensing information

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Journal of Environmental Sciences 2001年第4期13卷 439-443页

作者： Zhang, J.-h. Fu, c.-b. Kanzawa, h. START Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The canopy stomatal movement, a plant physiological process, generally occurs within leaves but its influence on exchange of cO2, water vapor, and sensible heat fluxes between atmosphere and terrestrial ecosystem. Many studies have documented that the interaction between leaf photosynthesis and canopy stomatal conductance is obvious. Thus, information on stomatal conductance is valuable in climate and ecosystem models. In current study, a newly developed model was adopted to calculate canopy stomatal conductance of winter wheat in huang-huai-hai (h-h-h) Plain of china (31.5 - 42.7°N, 110.0 - 123.0°E). The remote sensing information from NOAA-AVhRR and meteorological observed data were used to estimate regional scale stomatal conductance distribution. canopy stomatal conductance distribution pattern of winter wheat on March 18, 1997 was also presented. The developed canopy stomatal conductance model might be used to estimate canopy stomatal conductance in land surface schemes and seems can be acted as a boundary condition in regional climatic model runs.

关键词： carbon dioxide Data reduction Ecosystems heat flux Meteorology Photosynthesis Physiology Plants (botany) Remote sensing Vapors

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Effects of aluminum co-doping on photoluminescence properties of ce^(3+)-doped SiO_2 glasses

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Journal of Rare Earths 2010年第S1期28卷 206-210页

作者： LF KOAO h.c.SWART F.b.DEJENE Department of Physics University of the Free State(Qwaqwa Campus)Private Bag X13Phuthaditjhaba9866South Africa Department of Physics University of the Free StateP.O.Box 339Bloemfontein9300South Africa

SiO2 glasses co-doped with Al3+ ions were prepared by a sol-gel method by holding 0.5% of ce3+ ions constant and varying the Al3+ ions *** stability,the structural,chemical and the optical properties of the samples were studied by using differential scanning calorimetric(DSc),thermo gravimetric analysis(TGA),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),UV-vis spectroscopy and photoluminescence spectroscopy(PL).The DSc and TGA of samples depicted that the presence of dopant and co-dopant decreased the endothermic peak temperature and the yield *** images showed that the particles were in the nano-range and spherical in *** XRD showed that all the samples were *** UV absorption measurements indicated that the presence of Al3+ ions significantly reduced the SiO2 absorption band,increased the absorbance intensity of SiO2 and decreased the transmittance as compared to the presence of the ce3+ ions *** photoluminescence results displayed an optimum increase in luminescence intensity when the ratio of Al:ce was 10:1 and further increase in aluminum content quenched the luminous intensity.

关键词： SiO2:ce Al when sol-gel molar ration nano-size luminescence enhancement rare earths

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Exact solution and transient behavior for torsional vibration of functionally graded finite hollow cylinders

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Acta Mechanica Sinica 2009年第4期25卷 555-563页

作者： h. M. Wang c. b. Liu h. J. Ding Department of Mechanics Zhejiang University Department of civil Engineering Zhejiang University

Exact solutions are obtained for transient torsio- nal responses of a finitely long, functionally graded hollow cylinder under three different end conditions, i.e. free-free, free-fixed and fixed-fixed. The cylinder with its external surface fixed is subjected to a dynamic shearing stress at the internal surface. The material properties are assumed to vary in the radial direction in a power law form, while keep invariant in the axial direction. With expansion in the axial direction in terms of trigonometric series, the governing equations for the unknown functions about the radial coordinate r and time t are deduced. by applying the variable substitution technique, the superposition method and the separation of variables consecutively, series-form solutions of the equations are obtained. Natural frequencies and the transient torsional responses are finally discussed for a functionally graded finite hollow cylinder.

关键词： Exact solution Functionally graded material Finite hollow cylinder Transient torsional vibration

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Ultra‑Transparent and Multifunctional IZVO Mesh Electrodes for Next‑Generation Flexible Optoelectronics

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Nano-Micro Letters 2025年第1期17卷 293-309页

作者： Kiran A.Nirmal Tukaram D.Dongale Atul c.Khot chenjie Yao Nahyun Kim Tae Geun Kim School of Electrical Engineering Korea UniversityAnam‑ro 145Seongbuk‑guSeoulRepublic of Korea computational Electronics and Nanoscience Research Laboratory School of Nanoscience and BiotechnologyShivaji UniversityKolhapur 416004India

Mechanically durable transparent electrodes are essential for achieving long-term stability in flexible optoelectronic ***,they are crucial for applications in the fields of energy,display,healthcare,and soft *** meshes represent a promising alternative to traditional,brittle,metal oxide conductors due to their high electrical conductivity,optical transparency,and enhanced mechanical *** this paper,we present a simple method for fabricating an ultra-transparent conducting metal oxide mesh electrode using selfcracking-assisted *** this method,we produced an electrode with ultra-transparency(97.39%),high conductance(Rs=21.24Ωsq^(−1)),elevated work function(5.16 eV),and good mechanical *** also evaluated the effectiveness of the fabricated electrodes by integrating them into organic photovoltaics,organic light-emitting diodes,and flexible transparent memristor devices for neuromorphic computing,resulting in exceptional device *** addition,the unique porous structure of the vanadium-doped indium zinc oxide mesh electrodes provided excellent flexibility,rendering them a promising option for application in flexible optoelectronics.

关键词： Self-cracking template Vanadium-doped indium zinc oxide mesh Organic solar cells Organic light-emitting diodes Flexible transparent memory

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