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An in-situ Technique for Producing Low-Cost Agricultural Biochar

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Pedosphere 2018年第4期28卷 690-695页

作者： zhou qifa Benjamin A.HOUGE Zhaohui TONG Bin GAO Guodong LIU College of Life Sciences Zhejiang University Horticultural Sciences Department University of Florida Agricultural and Biological Engineering Department University of Florida

Application of biochar to agricultural soils is effective to sequester atmospheric carbon and improve soil quality, but current pyrolysis and transportation costs are high, making biochar too costly to be used at the field scale. This study developed a new in-situ technique, burning and soil covering(B-SC), which can be used by farmers for production of biochar with crop residue. In this study,the air-dried feedstocks, elephant grass and corn residue, were burnt in situ for biochar production in the field. After approximately 90% of the leaves were combusted, the burning process was dramatically slowed down by covering the feedstock with soil. The biochar yield averaged 18.0 ± 1.3(n = 15) and 13.7 ± 1.3(n = 10) kg per 100 kg air-dried feedstock for the elephant grass and corn residue,respectively. The biochar properties were suitable for soil improvement. The inputs for biochar production of the B-SC process only included low labor force, open field, feedstock(e.g., grass and crop residue), and simple tools. The operation time for processing 10 kg of the corn residue by an individual farmer was 24.4 ± 4.1 min(n = 10). As compared with the conventional field burning process, the B-SC process drastically shortened the time for biomass burning and generated a significantly lower emission of smoke and thermal energy. This simple technique can be particularly practical and effective for farmers to improve the soils of poor quality in China.

关键词： burning crop residue feedstock field burning soil covering soil quality

Concurrent photoacoustic and ultrasound microscopy with a coaxial dual-element ultrasonic transducer

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Visual Computing for Industry,Biomedicine,and Art 2018年第1期1卷 18-23页

作者： Yuqi Tang Wei Liu Yang Li qifa zhou Junjie Yao Department of Biomedical Engineering Duke UniversityDurhamNC 27708USA Department of Ophthalmology Department of Biomedical EngineeringUniversity of Southern CaliforniaLos AngelesCA 90089USA

Simultaneous photoacoustic and ultrasound(PAUS)imaging has attracted increasing attention in biomedical research to probe the optical and mechanical properties of ***,the resolution for majority of the existing PAUS systems is on the order of 1 mm as the majority are designed for clinical use with low-frequency US *** we developed a concurrent PAUS microscopy that consists of optical-resolution photoacoustic microscopy(OR-PAM)and high-frequency US pulse-echo *** dual-modality system utilizes a novel coaxial dual-element ultrasonic transducer(DE-UST)and provides anatomical and functional information with complementary contrast mechanisms,achieving a spatial resolution of 7μm for PA imaging and 106μm for US *** performed phantom studies to validate the system’s *** vasculature of a mouse’s hind paw was imaged to demonstrate the potential of this hybrid system for biomedical applications.

关键词： Photoacoustic microscopy Ultrasound microscopy Concurrent imaging Coaxial dual-element ultrasonic transducer

Study on the pyroelectric properties of PLT/P(VDF-TrFE) nanocomposites

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Chinese Science Bulletin 1998年第2期43卷 111-114页

作者： Qingqi Zhang H. L. W. Chan qifa zhou C. L. Choy Hong Kong Polytech Univ Dept Appl Phys Hung Hom Hong Kong Hong Kong Polytech Univ Mat Res Ctr Hung Hom Hong Kong

Lead lanthanum titanate (PLT) nanocrystalline powder prepared by the sol_gel process was incorporated into a polyvinylidene fluoride/trifluoroethylene (P(VDF_TrEF)) copolymer matrix to form PLT/P(VDF_TrFE) nanocomposites. The permittivities (ε) of the nanocomposites as a function of volume fraction of ceramic  were modeled using the Bruggeman model. The pyroelectric coefficients (p) and figure of merit (p/ε) were measured as functions of the poling field E. The nanocomposite has p and p/ε values higher than those of the copolymer, and has good potential in pyroelectric applications.

关键词： nanocomposites pyroelectric.

Suppression of starch synthase I(SSI) by RNA interference alters starch biosynthesis and amylopectin chain distribution in rice plants subjected to high temperature

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The Crop Journal 2019年第5期7卷 573-586页

作者： Qian Zhao Xiaoxia Du Zhanyu Han Yu Ye Gang Pan Muhammad-Asad-Ullah Asad qifa zhou Fangmin Cheng Institute of Crop Science College of Agriculture and BiotechnologyZhejiang UniversityHangzhou 310058ZhejiangChina Jiangsu Collaborative Innovation Center for Modern Crop Production Nanjing 210095JiangsuChina

Based on known cDNAs of rice starch synthase isoforms,we constructed dsRNA interference vectors for starch synthase I(SSI)to produce transgenic plants containing starch with a moderately high amylose *** investigated the effect of SSI suppression on grain quality traits,starch biosynthesis,and amylopectin chain distribution in rice plants exposed to two different temperature *** activities and transcripts of BEs,DBEs,and other SS isoforms were further investigated to clarify the effect of SSI suppression on these key enzymes and their specific isoforms under different temperature *** of SSI by RNAi altered grain starch component and amylopectin chain distribution,but it exerted only a slight effect on total starch content(%)and accumulation amount(mg kernel?1)and on starch granule morphology and particle size *** normal temperature(NT),insignificant differences in kernel weight,chalky kernel proportion,chalky degree,and starch granule morphology between SSI-RNAi line and its wild type(WT)were ***,amylose content(AC)level and granule-bound starch synthase(GBSS)activity in rice endosperms were markedly increased by SSI-RNAi *** chalky kernel proportion and chalky degree of SSIRNAi lines were significantly higher than those of WT under high temperature(HT)exposure at filling *** of SSI by RNAi affected amylopectin chain distribution and raised starch gelatinization temperature(GT)in two ways:directly from the SSI deficiency itself and indirectly by reducing BEIIb amounts in an SSI-deficient *** deficiency of SSI expression led to an alteration in the susceptibility of grain chalkiness occurrence and starch gelatinization temperature to HT exposure,owing to a pleiotropic effect of SSI deficiency on the expression of other genes associated with starch biosynthesis.

关键词： Rice Starch synthase I RNA interference Grain quality Amylopectin High temperature

Development of Moderate Intensity Focused Ultrasound(MIFU)for Ocular Drug Delivery

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Biomedical Engineering Frontiers 2022年第1期3卷 240-247页

作者： Alejandra Gonzalez-Calle Runze Li Isaac Asante Juan Carlos Martinez-Camarillo Stan Louie qifa zhou Mark S.Humayun USC Ginsburg Institute for Biomedical Therapeutics University of Southern CaliforniaLos Angeles CaliforniaUSA USC Roski Eye Institute Keck School of MedicineUniversity of Southern CaliforniaLos Angeles CaliforniaUSA Department of Biomedical Engineering University of Southern CaliforniaLos Angeles CaliforniaUSA USC School of Pharmacy University of Southern CaliforniaLos Angeles CaliforniaUSA

The purpose of this study is to develop a method for delivering antiinflammatory agents of high molecular weight(e.g.,Avastin)into the posterior segment that does not require injections into the eye(i.e.,intravitreal injections;IVT).Diseases affecting the posterior segment of the eye are currently treated with monthly to bimonthly intravitreal injections,which can predispose patients to severe albeit rare complications like endophthalmitis,retinal detachment,traumatic cataract,and/or increased *** this study,we show that one time moderate intensity focused ultrasound(MIFU)treatment can facilitate the penetration of large molecules across the scleral barrier,showing promising evidence that this is a viable method to deliver high molecular weight medications not *** validate the efficacy of the drug delivery system,IVT injections of vascular endothelial growth factor(VEGF)were used to create an animal model of *** creation of this model allowed us to test anti-VEGF medications and evaluate the efficacy of the *** vivo testing showed that animals treated with our MIFU device improved on the retinal tortuosity and clinical dilation compared to the control group while evaluating fluorescein angiogram(FA)Images.

关键词： viable Focus MIF

Real-time whole-brain imaging of hemodynamics and oxygenation at micro-vessel resolution with ultrafast wide-field photoacoustic microscopy

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Light(Science & Applications) 2022年第6期11卷 1238-1252页

作者： Xiaoyi Zhu Qiang Huangl Anthony Dispirito Tri Vu Qiangzhou Rong Xiaorui Peng Huaxin Sheng Xiling Shen qifa zhou Laiming Jiang Ulrike Hoffmann Junjie Yao Department of Biomedical Engineering Duke UniversityDurhamNC 27708USA Department of Pediatric Surgery Second Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina Roski Eye Institute Department of OphthalmologyKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA 90033USA Department of Biomedical Engineering University of Southern CaliforniaLos AngelesCA 90089USA Department of Anesthesiology Duke UniversityDurhamNC 27708USA

High-speed high-resolution imaging of the whole-brain hemodynamics is critically important to facilitating neurovascular *** imaging speed and image quality are crucial to visualizing real-time hemodynamics in complex brain vascular networks,and tracking fast pathophysiological activities at the microvessel level,which will enable advances in current queries in neurovascular and brain metabolism research,including stroke,dementia,and acute brain ***,real-time imaging of oxygen saturation of hemoglobin(sO_(2))can capture fast-paced oxygen delivery dynamics,which is needed to solve pertinent questions in these fields and ***,we present a novel ultrafast functional photoacoustic microscopy(UFF-PAM)to image the whole-brain hemodynamics and ***-PAM takes advantage of several key engineering innovations,including stimulated Raman scattering(SRS)based dual-wavelength laser excitation,water-immersible 12-facet-polygon scanner,high-sensitivity ultrasound transducer,and deep-learning-based image upsampling.A volumetric imaging rate of 2 Hz has been achieved over a field of view(FOV)of 11×7.5×1.5 mm^(3) with a high spatial resolution of~10 μ*** the UFF-PAM system,we have demonstrated proof-of-concept studies on the mouse brains in response to systemic hypoxia,sodium nitroprusside,and *** observed the mouse brain's fast morphological and functional changes over the entire cortex,including vasoconstriction,vasodilation,and *** interestingly,for the first time,with the whole-brain FOV and micro-vessel resolution,we captured the vasoconstriction and hypoxia simultaneously in the spreading depolarization(SD)*** expect the new imaging technology will provide a great potential for fundamental brain research under various pathological and physiological conditions.

关键词： metabolism ultrafast resolution

Highly Integrated Multiplexing and Buffering Electronics for Large Aperture Ultrasonic Arrays

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Biomedical Engineering Frontiers 2022年第1期3卷 262-283页

作者： Robert Wodnicki Haochen Kang Di Li Douglas N.Stephens Hayong Jung Yizhe Sun Ruimin Chen Lai-Ming Jiang Nestor E.Cabrera-Munoz Josquin Foiret qifa zhou Katherine W.Ferrara Department of Biomedical Engineering University of Southern CaliforniaLos AngelesCAUSA Department of Biomedical Engineering University of CaliforniaDavisDavisCAUSA Molecular Imaging Program at Stanford University StanfordCAUSA USC Roski Eye Institute University of Southern CaliforniaLos AngelesCAUSA

Large aperture ultrasonic arrays can be implemented by tiling together multiple pretested modules of high-density acoustic arrays with closely integrated multiplexing and buffering electronics to form a larger aperture with high *** modular arrays can be used to implement large 1.75D array apertures capable of focusing in elevation for uniform slice thickness along the axial direction which can improve image *** important goal for large array tiling is obtaining high yield and sensitivity while reducing extraneous image *** have been developing tileable acoustic-electric modules for the implementation of large array apertures utilizing Application Specific Integrated Circuits(ASICs)implemented using 0.35μm high voltage(50 V)*** generations of ASICs have been designed and *** ASICs were integrated with high-density transducer arrays for acoustic testing and *** modules were further interfaced to a Verasonics Vantage imaging system and were used to image industry standard ultrasound *** first-generation modules comprise ASICs with both multiplexing and buffering electronics on-chip and have demonstrated a switching artifact which was visible in the images.A second-generation ASIC design incorporates low switching injection circuits which effectively mitigate the artifacts observed with the first-generation ***,we present the architecture of the two ASIC designs and module types as well imaging results that demonstrate reduction in switching artifacts for the second-generation devices.

关键词： Highly Large utilizing

PZT FILM GENERATOR DRIVEN BY ULTRASONIC WAVE

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Journal of Advanced Dielectrics 2012年第3期2卷 1-5页

作者： qifa zhou KWOK HO LAM BENPENG ZHU XIABING ZHANG K.KIRK SHUNG TONGQING YANG S.TAKEUCHI NIH Transducer Resource Center Department of Biomedical Engineering University of Southern California Los Angeles CA 90089 USA Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan 430072 China Functional Materials Research Laboratory Tongji University Siping Road 1239 ShanghaiChina Medical Engineering Course Graduate School of Engineering Toin University of Yokohama Yokohama 225-8501 Japan

Energy harvesting was demonstrated in hydrothermal PZT nanocrystal films driven by *** high temperature sintering and solution infiltration,PZT films with nanograin sizewas found to exhibit bulk-like properties such as large remnant polarization of 42μC/cm^(2).Withthe bulk-like properties,a packaged PZT film device was demonstrated to be capable of convertingmechanical energy carried by the ultrasonic wave into electrical energy in a reliable and efficient *** result suggests an alternative potential solution for energy harvesting application.

关键词： PZT film ultrasonic energy harvesting

ecent Advances in the Science of Burst Wave Lithotripsy and Ultrasonic Propulsion

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Biomedical Engineering Frontiers 2022年第1期3卷 54-66页

作者： Xuejun Qian Gengxi Lu Biju B.Thomas Runze Li Xiaoyang Chen K.Kirk Shung Mark Humayun qifa zhou Department of Biomedical Engineering University of Southern CaliforniaLos AngelesCA 90089USA Department of Ophthalmology University of Southern CaliforniaLos AngelesCA 90033USA USC Ginsburg Institute for Biomedical Therapeutics University of Southern CaliforniaLos AngelesCA 90033USA

*** degeneration involving progressive deterioration and loss of function of photoreceptors is a major cause of permanent vision loss *** to treat these incurable conditions incorporate retinal prostheses via electrically stimulating surviving retinal neurons with implanted devices in the eye,optogenetic therapy,and sonogenetic *** challenges of these strategies include invasive manner,complex implantation surgeries,and risky gene *** and ***,we show that direct ultrasound stimulation on the retina can evoke neuron activities from the visual centers including the superior colliculus and the primary visual cortex(V1),in either normal-sighted or retinal degenerated blind rats in *** neuron activities induced by the customized spherically focused 3.1 MHz ultrasound transducer have shown both good spatial resolution of 250μm and temporal resolution of 5 Hz in the rat visual *** additional customized 4.4 MHz helical transducer was further implemented to generate a static stimulation pattern of letter *** findings demonstrate that ultrasound stimulation of the retina in vivo is a safe and effective approach with high spatiotemporal resolution,indicating a promising future of ultrasound stimulation as a novel and noninvasive visual prosthesis for translational applications in blind patients.

关键词： stimulation implantation letter