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Changes of cerebral blood flow in rats with acute cerebral ischemia and the effect of nitric oxide donor S-nitroso-N-acetyl-penicillamine

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Neural Regeneration Research 2006年第5期1卷 393-396页

作者： Feng gao Zhiqiang yi Guijun Lin Department of Neurosurgery Aerospace Central HospitalPeking University Beijing 100049 China

BACKGROUND ： Previous studies show that nitric oxide donor can increase cerebral blood flow and improve the function of neurons in cerebral ischemia, but the change does not happen in all the models of cerebral ischemia. OBJECTIVE ： To observe the effects of nitric oxide donor S-nitroso-N-acetyl-penicillamine （SNAP） on the cerebral blood flow, cyclic guanosine monophosphate （cGMP） content in cerebral cortex, infarct volume and blood pressure in acute ischemic rat brain.DESIGN ： A randomized and control animal experiment SEI-FING ： Department of Neurosurgery, Aerospace Central Hospital, Peking University.MATERIALS： Twenty-eight male Wistar rats of SPF grade, weighing 250-300 g, aged 10-12 weeks were randomly divided into control group （n =14） and SNAP-treated group （n =14）. SNAP （5 mg/bottle） was provided by Beijing Chemical Reagent Company. Laser Doppler Flowmeter （FLO C1; Omegawave Inc., Tokyo, Japan） and immunoassay kit （Amersham Pharmacia Biotech, UK） were applied. METHODS： ① Model establishment： In the control group, models of cerebral ischemia were induced by ligating right common, internal and external carotid arteries; In the SNAP-treated group, models of cerebral ischemia were induced by ligating right common and external carotid arteries, followed by occluding middle cerebral artery and ligating internal carotid artery. ②Administration： In the SNAP-treated group, SNAP （100 μg/kg） was intravenously infused within 2 minutes, whereas in the control group, phosphate buffered saline （PBS, 1 mL） was intravenously infused （0.5 mL per minute）. Six rats were used to measure the volume of cerebral infarction, and the other 8 rats were used to determine other indexes in each group respectively. ③ Determination of indexes： Regional cerebral blood flow （rCBF） was continuously measured by laser-Doppler flowmetry in the ischemic penumbra and contralateral cortex under the continuous monitoring of blood pressure, cGMP concentrations in brain tissue were determined

关键词： nitric oxide cerebral ischemia cerebral infarction cerebral blood flow blood pressure middle cerebral artery intravenous infusion carotid arteries internal carotid artery continuous monitoring enzyme immunoassay ischemic penumbra animal experiment measurement data Chemical Reagent cerebral cortex caudate nucleus Wistar rats

In vitro reconstitution guide for targeted synthetic metabolism of chemicals, nutraceuticals and drug precursors

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Synthetic and Systems Biotechnology 2016年第1期1卷 25-33页

作者： gao-yi Tan Faying Zhu Zixin Deng Tiangang Liu Key Laboratory of Combinatorial Biosynthesis and Drug Discovery(Wuhan University) Ministry of EducationAnd Wuhan University School of Pharmaceutical SciencesWuhan430071China Hubei Engineering Laboratory for Synthetic Microbiology Wuhan Institute of BiotechnologyWuhan430075China

With the developments in metabolic engineering and the emergence of synthetic biology,many breakthroughs in medicinal,biological and chemical products as well as biofuels have been achieved in recent *** an important barrier to traditional metabolic engineering,however,the identification of ratelimiting step(s)for the improvement of specific cellular functions is often ***,in the case of synthetic biology,more and more BioBricks could be constructed for targeted purposes,but the optimized assembly or engineering of these components for high-efficiency cell factories is still a *** to the lack of steady-state kinetic data for overall flux,balancing many multistep biosynthetic pathways is time-consuming and needs vast resources of labor and materials.A strategy called targeted engineering is proposed in an effort to solve this ***,a targeted biosynthetic pathway is to be reconstituted in vitro and then the contribution of cofactors,substrates and each enzyme will be analyzed *** is in vivo engineering or de novo pathway assembly with the guidance of information gained from in vitro *** demonstrate its practical application,biosynthesis pathways for the production of important products,***,nutraceuticals and drug precursors,have been engineered in Escherichia coli and Saccharomyces *** cases can be regarded as concept proofs indicating targeted engineering might help to create high-efficiency cell factories based upon constructed biological components.

关键词： Targeted engineering In vitro reconstitution Fatty acid Terpene Polyketide

Impacts of the meteorological condition versus emissions reduction on the PM_(2.5) concentration over Beijing-Tianjin-Hebei during the COVID-19 lockdown

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Atmospheric and Oceanic Science Letters 2021年第4期14卷 38-44页

作者： Yanqing Zhang Zhaokun Ma yi gao Meigen Zhang State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijingChina Shandong Academy for Environmental Planning JinanChina

The impacts of the meteorological condition and emissions reduction on the aerosol concentration over the Beijing-Tianjin-Hebei(BTH) region during the COVID-19 lockdown were analyzed by conducting three numerical experiments,including one with the meteorological field in 2019 and MEIC-2019(2019 monthly Multi-resolution Emissions Inventory for China),one with the meteorological field in 2020 and MEIC-2019,and one with the meteorological field in 2020 and MEIC-2020,via a WRF-Chem *** numerical experiments were performed from 3 to 16 February in 2019 and in 2020,during which a severe fog-haze event(3-16 February 2020) occurred in the BTH region,with a simulated maximum daily PM2.5 of 245μg m-3 in Tangshan and 175μg m-3 in *** results indicate that the daily PM2.5 decreased by 5-150μg m-3 due to the emissions reduction and increased by 10-175 μg m-3 due to the meteorological condition in Beijing,Shijiazhuang,Cangzhou,Handan,Hengshui,Chengde,Zhangjiakou,and Tangshan from 7 to 14 *** the horizontal distribution,PM2.5 and different aerosol species concentrations from 7 to 14 February 2020 increased compared with those during the same period in 2019,indicating that the accumulation of pollutants caused by the unfavorable meteorological condition offset the decreases caused by the emissions reduction,leading to the high aerosol concentration during the COVID-19 lockdown.

关键词： PM_(2.5) WRF-Chem Meteorological condition Emissions reduction

Use of Deep Learning for Continuous Prediction of Mortality for All Admissions in Intensive Care Units

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Tsinghua Science and Technology 2023年第4期28卷 639-648页

作者： Guangjian Zeng Jinhu Zhuang Haofan Huang Mu Tian yi gao Yong Liu Xiaxia Yu School of Biomedical Engineering Health Science CenterShenzhen UniversityShenzhen 518060China Shenzhen Hospital Southern Medical UniversityShenzhen 518060China

The mortality rate in the intensive care unit(ICU)is a key metric of hospital clinical *** enhance hospital performance,many methods have been proposed for the stratification of patients’different risk categories,such as severity scoring systems and machine learning ***,these methods make capturing time sequence information difficult,posing challenges to the continuous assessment of a patient’s severity during their hospital ***,we built a predictive model that can make predictions throughout the patient’s stay and obtain the patient’s risk of death in real *** proposed model performed much better than other machine learning methods,including logistic regression,random forest,and XGBoost,in a full set of performance evaluation ***,the proposed model can support physicians’decisions by allowing them to pay more attention to high-risk patients and anticipate potential complications to reduce ICU mortality.

关键词： deep learning representation learning mortality risk prediction critical care

Novel insights into congenital surfactant dysfunction disorders by in silico analysis of ABCA3 proteins

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World Journal of Pediatrics 2023年第3期19卷 293-301页

作者： Guo-Liang Xiao Yuan gao Hu Hao Tao Wei Chun Hong Yue Wang ying-yi Lin Xiu-Fang Chi ying Liu Hong-yi gao Chuan Nie Department of Neonatology Guangdong Women and Children HospitalGuangzhou 511442China Guangdong Neonatal ICU Medical Quality Control Center Guangzhou 511442China Department of Marine Science College of OceanographySouth China Agricultural UniversityGuangzhouChina Department of Neonatology The Sixth Affiliated Hospital of Sun Yat-Sen UniversityGuangzhouChina Department of Bioengineering College of Food Science and Institute of Food BiotechnologySouth China Agricultural UniversityGuangzhouChina Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province GuangzhouChina Department of Thoracic Surgery Guangdong Women and Children HospitalGuangzhouChina Department of Pathology Guangdong Women and Children HospitalGuangzhou 511442GuangzhouChina

Surfactants produced by typeⅡalveolar epithelial cells(AT2 cells)are usually present in inclusion organelles called lamellar bodies(LBs).The ATP-binding cassette subfamily A member 3(ABCA3)transporter primarily exists in AT2 cells and is generally considered to be one of the critical regulators of biogenesis of LBs and surfactant metabolism in the lungs[1-4].ABCA3 mutations are the most com-mon cause of congenital surfactant dysfunction disorders(CSDDs),resulting in fatal neonatal respiratory distress and pediatric or adult interstitial lung disease[3,5-7].More than 200 disease-associated ABCA3 variants have been identi-fied in symptomatic infants and children[8].The estimated prevalence of deleterious ABCA3 mutations in the popu-lation is 1/70-1/33,with a predicted disease incidence of 1/20,000-1/4400[7].

关键词： congenital metabolism distress

Exploration of structure sensitivity of gold nanoparticles in low-temperature CO oxidation

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Industrial Chemistry & Materials

Industrial Chemistry & Materials 2024年第2期2卷 321-327页

作者： Lei ying Yu Han Beien Zhu yi gao Key Laboratory of Interfacial Physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Phonon Science Research Center for Carbon Dioxide Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China Key Laboratory of Low-Carbon Conversion Science&Engineering Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China

Gold nanoparticles(NPs)exhibit remarkable catalytic activity in low-temperature CO oxidation and their performance is highly dependent on size and ***,the underlying mechanism isn't fully understood ***,we combine density functional theory calculations,a multiscale structure reconstruction model,and kinetic Monte Carlo simulations to investigate the activity and structure sensitivity of Au NPs under different reaction *** results indicate that increasing the partial pressure ratio of O_(2) to CO leads to the decrease of optimal reaction temperature accompanied with the increase of *** low temperatures,the morphology of the NPs evolves to expose a higher proportion of(110)facets to promote the activity ***,the size dependence analysis suggests that O_(2)-rich conditions are favorable for small-sized NPs,while CO-rich conditions favor the large-sized *** findings not only enrich our basic understanding of the structure–reactivity relationship and the origin of structure sensitivity in gold-catalysis,but provide a guide for rational design of Au catalysts.

关键词： Kinetic Monte Carlo CO oxidation Gold catalysis Nanoparticles

Effects of an Engineered Anti-HER2 Antibody chA21 on Invasion of Human Ovarian Carcinoma Cell In Vitro

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Chinese Journal of Cancer Research 2011年第2期23卷 147-152页

作者： yi gao Qiang Wu Zheng-sheng Wu Gui-hong Zhang An-li Zhang Department of Pathology Anhui Medical University Hefei 230032 China

Objective： HER-2 plays an important role in the development and progression of ovarian carcinoma. A number of monoclonal antibodies （MAbs） and engineered antibody fragments （such as scFvs） against the subdomain II or IV of HER-2 extracellular domain （ECD） have been developed. We investigated the effect of chA21, an engineered anti-HER-2 antibody that bind primarily to subdomain I, on ovarian carcinoma cell invasion in vitro, and explored its possible mechanisms. Methods： Growth inhibition of SK-OV-3 cells was assessed using a Methyl thiazolyl tetrazolium （MTT） assay. The invasion ability of SK-OV-3 was determined by a Transwell invasion assay. The expression of matrix metalloproteinase-2 （MMP-2） and its tissue inhibitors （TIMP-2） was detected by immunocytochemical staining, and the expression of p38 and the phosphorylation of p38 were assayed by both immunocytochemistry and Western blot. Results： After treatment with chA21, the invasion of human ovarian cancer SK-OV-3 cells was inhibited in dose- and time-dependent manners. Simultaneously the expression of p38, phospho-p38, MMP-2 and the MMP-2/TIMP-2 ratio decreased, while TIMP-2 expression increased. Additionally, the decrease in phospho-p38 was much greater than that of p38. Conclusion： chA21 may inhibit SK-OV-3 cell invasion via the signal transduction pathway involving MMP-2, TIMP-2, p38 and the activation of p38MAPK.

关键词： HER-2 Ovarian neoplasms Invasion p38 mitogen-activated protein kinase Matrix metalloproteinase-2 Tissue inhibitor of matrix metalloproteinase-2

Response Characteristics and Adiabatic Heating during High Strain Rate for TRIP Steel and DP Steel

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Journal of Iron and Steel Research International 2015年第1期22卷 48-54页

作者： yi gao Chao XU Zhong-ping HE Yan-lin HE Lin LI School of Materials Science and Engineering Shanghai University

By using a static and high-speed material testing machine, tensile deformation behaviors of two kinds of Si- Mn TRIP （transformation induced plasticity） steels and DP （dual phase） steel were studied in a large range of strain rates （0.001-2000 s 1）. Temperature variation during adiabatic heating and the amount of retained austenite at fracture were measured by an infrared thermometer and an Xray stress analyser, respectively. The microstructure of steels was observed by optical microscopy （OM） and scanning electron microscopy （SEM） before and after tensile test. It was found from the experimental results that the tensile strength of these steels increased, and the fracture elonga- tion firstly decreased and subsequently increased, as the strain rate increased in the range ＂of 0.1 - 2000 s -1. The temperature raised during adiabatic heating of TRIP steel was in the range of 100- 300℃, while that of the DP steel was in the range of 100-220℃ . The temperature rise of these steels increased with increasing the strain rate, as well as the amount of the transformed retained austenite in TRIP steels. It was confirmed that austenite to martensite transformation is not suppressed by adiabatic heating.

关键词： strain rate TRIP steel adiabatic heating retained austenite

3D printing preview for stereo-lithography based on photopolymerization kinetic models

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Bioactive Materials 2020年第4期5卷 798-807页

作者： yi gao Lei Xu Yang Zhao Zhengwei You Qingbao Guan State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Shanghai Belt and Road Joint Laboratory of Advanced Fiber and Low-dimension Materials(Donghua University)College of Materials Science and EngineeringDonghua UniversityShanghai201620PR China Center for Combustion Energy and Key Laboratory for Thermal Science and Power Engineering of MOE Tsinghua UniversityBeijing100084China Institute of Agricultural Facilities and Equipment Jiangsu Academy of Agricultural SciencesKey Laboratory for Protected Agricultural Engineering in the Middle and Lower Reaches of Yangtze RiverMinistry of Agriculture and Rural AffairsNanjing210014PR China

The diversity of biomedical applications makes stereolithographic(SL)three-dimensional(3D)printing process complex.A strategy was developed to simulate the layer-by-layer fabrication of 3D printed products combining polymerization kinetic with reaction conditions to realize print *** a representative example,the typical UV-curable dental materials based on epoxy acrylate and photoinitiator with different molar ratios was exposed under varying intensity of UV light to verify the simulation results.A theoretical kinetics model containing oxygen inhibition was ***-situ FTIR was employed to measure propagation and termination constants while coupled UV/vis was performed to examine the law of light attenuation during cure reaction,even with various colours and *** results showed that the correlation coefficient square between the experiments and simulations of epoxy acrylate with 1%,2%and 3%initiator upon 20 mW/cm2 UV light are 0.8959,0.9324 and 0.9337,***,our simulation of photopolymerization for SL 3D printing successfully realized visualization of printing quality before practically printing the targeted biomedical objects with complex topology structures.

关键词： 3D printing preview Photopolymerization kinetics Biomedical applications Dental materials Epoxy acrylate