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Emerging evidence of the physiological role of hypoxia in mammary development and lactation

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Journal of Animal Science and Biotechnology 2014年第3期5卷 262-272页

作者： Yong Shao feng-qi zhao Laboratory of Lactation and Metabolic Physiology Department of Animal ScienceUniversity of Vermont

Hypoxia is a physiological or pathological condition of a deficiency of oxygen supply in the body as a whole or within a tissue. During hypoxia, tissues undergo a series of physiological responses to defend themselves against a low oxygen supply, including increased angiogenesis, erythropoiesis, and glucose uptake. The effects of hypoxia are mainly mediated by hypoxia-inducible factor 1 （HIF-1）, which is a heterodimeric transcription factor consisting of o and 13 subunits. HIF-1β is constantly expressed, whereas HIF-1α is degraded under normal oxygen conditions. Hypoxia stabilizes HIF-1α and the HIF complex, and HIF then translocates into the nucleus to initiate the expression of target genes. Hypoxia has been extensively studied for its role in promoting tumor progression, and emerging evidence also indicates that hypoxia may play important roles in physiological processes, including mammary development and lactation. The mammary gland exhibits an increasing metabolic rate from pregnancy to lactation to support mammary growth, lactogenesis, and lactation. This process requires increasing amounts of oxygen consumption and results in localized chronic hypoxia as confirmed by the binding of the hypoxia marker pimonidazole HCI in mouse mammary gland. We hypothesized that this hypoxic condition promotes mammary development and lactation, a hypothesis that is supported by the following several lines of evidence： i） Mice with an HIF-1α deletion selective for the mammary gland have impaired mammary differentiation and lipid secretion, resulting in lactation failure and striking changes in milk compositions; ii） We recently observed that hypoxia significantly induces HIF-1α- dependent glucose uptake and GLUT1 expression in mammary epithelial cells, which may be responsible for the dramatic increases in glucose uptake and GLUT1 expression in the mammary gland during the transition period from late pregnancy to early lactation; and iii） Hypoxia and HIF-1α increase the phospho

关键词： Glucose transporter Hypoxia Hypoxia inducible factor Lactation Mammary development Metabolism

AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats

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Journal of Animal Science and Biotechnology 2020年第3期11卷 777-788页

作者： Jie Cai Diming Wang feng-qi zhao Shulin Liang Jianxin Liu Institute of Dairy Science College of Animal SciencesZhejiang UniversityHangzhou 310058People’s Republic of China

Background:The local supply of energy-yielding nutrients such as glucose seems to affect the synthesis of milk components in the mammary gland(MG).Thus,our study was conducted to investigate the effects of locally available MG glucose supply(LMGS)on amino acid(AA)sensing and utilization in the MG of lactating dairy *** dosages of glucose(0,20,40,60,80,and 100 g/d)were infused into the MG through the external pudendal artery to investigate the dose-dependent changes in mammary AA uptake and utilization(Exp.1)and the changes in mRNA and protein expression of the AMPK-mTOR pathway(Expt.2).Results:In Exp.1,total milk AA concentration was highest when goats were infused with 60 g/d glucose,but lower when goats were infused with 0 and 100 g/d *** LMGS quadratically changed the percentages ofαS2-casein andα-lactalbumin in milk protein,which increased with infusions from 0 to 60 g/d glucose and then decreased with infusions between 60 and 100 g/d *** LMGS changed the AA availability and intramammary gland AA utilization,as reflected by the mammary AA flux *** Exp.2,the mRNA expression of LALBA in the MG increased quadratically with increasing LMGS,with the highest expression at dose of 60 g/d glucose.A high glucose dosage(100 g/d)activated the general control nonderepressible 2 kinase,an intracellular sensor of AA status,resulting in a reduced total milk AA ***:Our new findings suggest that the lactating MG in dairy goats may be affected by LMGS through regulation of the AA sensory pathway,AA utilization and protein synthesis,all being driven by the AMPK-mTOR pathway.

关键词： Amino acid profile AMPK signaling Glucose supply Mammary gland Milk protein component

Magnetic properties of Fe_(3(1-x))Cr_(3x)C alloys

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International Journal of Minerals,Metallurgy and Materials 2009年第3期16卷 314-316页

作者： feng-qi zhao O. Tegus B. Fuquan E. Brück Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials College of Physics and Electron Information Inner Mongolia Normal University Hohhot 010022 China Van der Waals-Zeeman Instituut Universiteit van Amsterdam Valckenierstraat 65 1018XE Amsterdam Netherlands

The magnetic properties of Fe3（1-x）Cr3xC alloys with x=0.05, 0.1, 0.15, and 0.2, which crystallize in the cementite Fe3C-type structure with space group Pnma, were investigated by means of magnetization measurements. These alloys show temperature-induced second-order magnetic phase transitions. The Curie temperature （Tc） of these alloys decreases with increasing x. The isothermal magnetic-entropy changes of these alloys were derived from the magnetic isotherms measured with increasing temperature and increasing field. The maximum values of the magnetic-entropy change are about 0.9 and 3.6 J·kg^-1·K^-1 at Tc =360 K for x = 0.05 in a magnetic field change from 0 to 1 T and 0 to 5 T, respectively.

关键词： magnetic properties magnetocaloric effect magnetic-entropy change magnetic refrigeration

Sound event localization and detection based on deep learning

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Journal of Systems Engineering and Electronics 2024年第2期35卷 294-301页

作者： zhao Dada DING Kai qi Xiaogang CHEN Yu feng Hailin School of Mathematics and Statistics Xidian UniversityXi’an 710071China Science and Technology on Near-Surface Detection Laboratory Wuxi 214035China

Acoustic source localization(ASL)and sound event detection(SED)are two widely pursued independent research *** recent years,in order to achieve a more complete spatial and temporal representation of sound field,sound event localization and detection(SELD)has become a very active research *** paper presents a deep learning-based multioverlapping sound event localization and detection algorithm in three-dimensional ***-Mel spectrum and generalized cross-correlation spectrum are joined together in channel dimension as input *** features are classified and regressed in parallel after training by a neural network to obtain sound recognition and localization results *** channel attention mechanism is also introduced in the network to selectively enhance the features containing essential information and suppress the useless ***,a thourough comparison confirms the efficiency and effectiveness of the proposed SELD *** experiments show that the proposed algorithm is robust to reverberation and environment and can achieve higher recognition and localization accuracy compared with the baseline method.

关键词： sound event localization and detection(SELD) deep learning convolutional recursive neural network(CRNN) channel attention mechanism

Visible Light Indoor Positioning System Based on Pisarenko Harmonic Decomposition and Neural Network

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Chinese Journal of Electronics 2024年第1期33卷 195-203页

作者： Li zhao Yi REN qi WANG Lange DENG feng ZHANG School of Electronic Information Engineering Xi’an Technological University

Visible-light indoor positioning is a new generation of positioning technology that can be integrated into smart lighting and optical communications. The current received signal strength(RSS)-based visible-light positioning systems struggle to overcome the interferences of background and indoor-reflected noise. Meanwhile, when ensuring the lighting, it is impossible to use the superposition of each light source to accurately distinguish light source information; furthermore, it is difficult to achieve accurate positioning in complex indoor environments. This study proposes an indoor positioning method based on a combination of power spectral density detection and a neural network. The system integrates the mechanism for visible-light radiation detection with RSS theory, to build a back propagation neural network model fitting for multiple reflection channels. Different frequency signals are loaded to different light sources at the beacon end, and the characteristic frequency and power vectors are obtained at the location end using the Pisarenko harmonic decomposition method. Then, a complete fingerprint database is established to train the neural network model and conduct location tests. Finally, the location effectiveness of the proposed algorithm is verified via actual positioning experiments. The simulation results show that, when four groups of sinusoidal waves with different frequencies are superimposed with white noise, the maximum frequency error is 0.104 Hz and the maximum power error is 0.0362 W. For the measured positioning stage, a 0.8 m × 0.8 m × 0.8 m solid wood stereoscopic positioning model is constructed, and the average error is 4.28 cm. This study provides an effective method for separating multi-source signal energies, overcoming background noise, and improving indoor visible-light positioning accuracies.

关键词： Neural networks Measurement uncertainty Position measurement Harmonic analysis Light emitting diodes Frequency estimation Indoor positioning systems

Explosion characteristics of aluminum-based activated fuels containing fluorine

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Defence Technology（防务技术） 2023年第2期20卷 34-43页

作者： Jin-tao Xu Lei Huang Hai-peng Jiang Tian-jiao Zhang feng-qi zhao Jian-kan Zhang Wei Gao State Key Laboratory of Fine Chemicals Department of Chemical Machinery and Safety EngineeringDalian University of TechnologyDalian116024China Beijing Institute of Aerospace Testing Technology Beijing100074China Science and Technology on Combustion and Explosion Laboratory Xi'an Modern Chemistry Research InstituteXi'an710065China

Measuring the dust explosion characteristics of aluminum-based activated fuels was a prerequisite for developing effective prevention and control *** this paper,ignition sensitivity,flame propagation behaviors and explosion severity of aluminum/polytetrafluoroethylene(Al/PTFE)compositions including 2 PT(2.80 wt.%F),4 PT(7.18 wt.%F)and 8 PT(11.90 wt.%F)were *** the content of F increased from 2.80 wt.%to 11.90 wt.%,the minimum explosive concentration MEC decreased from380 g/m^(3)to 140 g/m^(3),due to the dual effects of increased internal active aluminum and enhanced *** average flame propagation velocities increased as the percentage of F *** maximum explosion pressure Pmof 500 g/m3aluminum-based activated fuels increased from 247 k Pa to299 *** electron microscopy demonstrated that with the increase of PTFE content,the reaction was more *** this basis,the explosion mechanism of aluminum-based activated fuels was revealed.

关键词： Aluminum-based activated fuels Ignition sensitivity Flame propagation Explosion severity Explosion mechanism

A Study of Estimating the Safe Storage Life, Self-accelerating Decomposition Temperature and Critical Temperature of Thermal Explosion of Double-base Propellant Using Isothermal and Non-isothermal Decomposition Behaviours

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Chinese Chemical Letters 2006年第5期17卷 667-670页

作者： feng qi zhao Hong Xu GAO Rong Zu HU Gui E LU Jin Yong JIANG Xi＇ an Modem Chemistry Research Institute Xi＇ an 710065 Ordnance Engineering Institute Shijiazhuang 050003

A method of estimating the safe storage life （τ）, self-accelerating decomposition temperature （TsADT） and critical temperature of thermal explosion （Tb） of double-base propellant using isothermal and non-isothermal decomposition behaviours is presented. For double-base propellant composed of 56±1wt% of nitrocellulose （NC）, 27±0.5wt% of nitroglycerine （NG）, 8.15±0.15wt% of dinitrotoluene （DNT）, 2.5±0.1wt% of methyl centralite, 5.0±0.15wt% of catalyst and 1.0±0.1wt% of other, the values of r of 49.4 years at 40℃, of TSAOT of 151.35℃ and of Tb of 163.01℃ were obtained.

关键词： Safe storage life self-accelerating decomposition temperature critical temperature of thermal explosion double-base propellant thermal accelerated aging test DSC kinetic parameters.

Estimation of the kinetic parameters for thermal decomposition of HNIW and its adiabatic time-to-explosion by Kooij formula

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Defence Technology（防务技术） 2014年第1期10卷 28-33页

作者： Hong-xu GAO feng-qi zhao Rong-zu HU Hong-an zhao Hai ZHANG Science and Technology on Combustion and Explosion Laboratory Xi’an Modern Chemistry Research Institute College of Communication Science and Engineering Northwest University Department of Mathematics Northwest University

A differential/integral method to estimate the kinetic parameters(apparent activation energy Eaand pre-exponential factor A) for thermal decomposition reaction of energetic materials based on Kooij formula are applied to study the nonisothermal decomposition reaction kinetics of hexanitrohexaazaisowurtzitane(HNIW) by analyzing nonisothermal DSC curve data. The apparent activation energy(Ea) obtained by the integral isoconversional non-isothermal method based on Kooij formula is used to check the constancy and validity of apparent activation energy by the differential/integral method based on Kooij formula. The most probable mechanism function of thermal decomposition reaction of HNIW is determined by a logical choice method. The equations for calculating the critical temperatures of thermal explosion(Tb) and adiabatic time-toexplosion(tTIad) based on Kooij formula are used to calculate the values of Tband tTIadto evaluate the thermal safety and heat-resistant ability of HNIW. All the original data needed for analyzing the kinetic parameters are from nonisothermal DSC curves. The results show that the kinetic model function in differential form and the values of Eaand A of decomposition reaction of HNIW are 3(1 a)[ ln(1 a)]2/3, 152.73 kJ mol 1and 1011.97s 1, respectively, and the values of self-accelerating decomposition temperature(TSADT), Tband tTIadare 486.55 K, 493.11 K and52.01 s, respectively.

关键词：动力学参数热分解反应 HNIW 估算绝热分解反应动力学表观活化能 DSC曲线

Synthesis,crystal structure and thermal behavior of 4-amino-3,5-dinitropyrazole copper salt

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Chinese Chemical Letters 2014年第6期25卷 902-906页

作者： Ying-Lei Wang feng-qi zhao Yue-Ping Ji Jian-Hua Yi Ting An Wei-Xiao Liu Science and Technology on Combustion and Explosion Laboratory Xi'an Modern Chemistry Research Institute

A novel energetic combustion catalyst, 4-amino-3,S-dinitropyrazole copper salt （[Cu（adnp）2（H2O）2]）, was synthesized in a yield of 93.6% for the first time. The single crystal of [Cu（adnp）2（H2O）2] was determined by single crystal X-ray diffraction. It crystallizes in a triclinic system, space group p^-1 with crystal parameters a = 5.541（3） A, b = 7.926（4） A, c = 10.231（5） A,β = 101.372（8）°, V = 398.3（3） A3, Z = 1, μ = 1.467 mm^-1, F（0 0 0） = 243, and Dc = 2.000 g cm^-3. The thermal behavior and non-isothermal decomposition reaction kinetics of [Cu（adnp）2（H2O）2] were studied by means of different heating rate differential scanning calorimetry （DSC）. The kinetic equation of major exothermic decomposition reaction for [Cu（adnp）2（H2O）2] was obtained. The entropy of activation （△S≠）, enthalpy of activation （△H≠）, free energy of activation （△G≠）, the self-accelerating decomposition temperature （TSADT） and the critical temperature of thermal explosion （Tb） are 59.42 j mol^-1 K^-1, 169.5 kJ mol^-1, 1141.26 kJ mol ^-1 457.3 K and 468.1 K, respectively.

关键词： Physical chemistry 4-Amino-3,5-dinitropyrazole copper salt Energetic combustion catalyst Crystal structure Thermal behavior