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Open Journal of Fluid Dynamics 2013年第4期3卷 286-301页

作者： xiuhua si Jinxiang Xi Jongwon Kim Department of Engineering Calvin College Grand Rapids USA Department of Mechanical and Biomedical Engineering Central Michigan University Mount Pleasant USA

The objective of this study is to systematically assess the influences of the larynopharyneal anatomical details on airflow and particle behaviors during exhalation by means of image-based modeling. A physiologically realistic nose-throat airway was developed with medical images. Individual airway anatomy such as uvula, pharynx, and larynx were then isolated for examination by progressively simplifying this image-based model geometry. Low Reynolds number (LRN) k-w model and Langrangian tracking model were used to simulate the dynamics of airflow and particle transport for a wide range of exhalation conditions (4-45 L/min) and particle sizes (1 nm-1 μm). Results showed that pharyngeal anatomical details exerted a significant impact on breathing resistance and particle profiles. Abrupt pressure drop resulting from the uvula-related airway obstruction was observed. Even though the total deposition rate in the nasal airway is largely unaffected by the upstream effect, the local deposition patterns vary notably. Results of this study also indicate that the pressure drop appears to be an appropriate parameter to characterize the geometric variations for diffusive depositions. Inclusion of pressure drop (D0.5Q-0.62dp0.07) gives an improved correlation than using the conventional diffusion factor (D0.5Q﹣0.28).

关键词： Medical Image-Based Modeling Nasal Airflow Uvula Breathing Resistance Nanoparticle Deposition

Nickel-catalyzed enantioselective reductive amination of benzylic ketones in alcohols

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Science China Chemistry 2024年第8期67卷 2566-2570页

作者： xiuhua Wang Jianrong Steve Zhou State Key Laboratory of Chemical Oncogenomics School of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhen 518055China

Asymmetric reductive amination directly converts ketones and amines to alkylamines, which are important motifs in *** report that cationic nickel complexes of chiral diphosphines promote enantioselective reductive amination of benzylic ketones with both arylamines and benzhydrazide. Isopropanol was used as a safe and cheap source of hydrogen instead of formic acid. The reaction can be readily applied to a concise synthesis of diarylethylamines, a class of neuroactive substances.

关键词： transfer hydrogenation nickel catalysis chiral alkylamine reductive amination synthetic method

Study on the oxidation mechanism of Al-siC composite at elevated temperature

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2077-2087页

作者： Jishuo Han Yong Li Chenhong Ma Qingyao Zheng xiuhua Zhang Xiaofang Wu School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Vesuvius Advanced Ceramics(China)Co. LtdSuzhou 215000China

Resin-bonded Al-siC composite was sintered at 1100,1300,and 1500℃ in the air,the oxidation mechanism was *** reaction models were also *** oxidation resistance of the Al-siC composite was significantly enhanced with temperature *** in the exterior of the composite was partially oxidized slightly,while the transformation of metastable Al_(4)C_(3) to stable Al_(4)siC_(4) existed in the *** 1100℃,Al in the interior reacted with residual C to form Al_(4)C_(3).With increasing to 1300℃,high temperature and low oxygen partial pressure lead to active oxidation of siC,and internal gas composition transforms to Al_(2)O(g)+CO(g)+siO(g)as the reaction *** Al_(4)C_(3) is formed,CO(g)and siO(g)are continuously deposited on its surface,transforming to Al_(4)siC_(4).At 1500℃,a dense layer consisting of siC and Al_(4)siC_(4) whiskers is formed which cuts off the diffusion channel of *** active oxidation of siC is accelerated,enabling more gas to participate in the synthesis of Al_(4)siC_(4),eventually forming hexagonal lamellar Al_(4)siC_(4) with mutual accumulation between siC *** Al enhances the oxidation resistance of *** addition,the in situ generated non-oxide is uniformly dispersed on a micro-scale and bonds siC stably.

关键词： Al-siC composite kiln furniture Al_(4)siC_(4) Al_(4)C_(3) oxidation mechanism

Comprehensive Risk Assessment of Sea Level Rise and Tropical Cyclones in Dongzhaigang Mangroves,China

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Chinese Geographical Science 2024年第4期34卷 631-646页

作者： DING Ruyi CAI Rongshuo YAN xiuhua LI Cuihua WANG Cui NIE Xinyu Third Institute of Oceanography Ministry of Natural ResourcesXiamen 361005China

Mangroves play a pivotal role in tropical and subtropical coastal ecosystem,yet they are highly vulnerable to the effects of climate change,particularly the accelerated global sea level rise(SLR)and stronger tropical cyclones(TCs).However,there is a lack of research addressing future simultaneous combined impacts of the slow-onset of SLR and rapid-onset of TCs on China's *** order to develop a comprehensive risk assessment method considering the superimposed effects of these two factors and analyze risk for mangroves in Dongzhaigang,Hainan Island,China,we used observational and climate model data to assess the risks to mangroves under low,intermediate,and very high greenhouse gas(GHG)emission scenarios(such as SSP1-2.6,SSP2-4.5,and SSP5-8.5)in 2030,2050,and 2100,and compiled a risk assessment scheme for mangroves in Dongzhaigang,*** results showed that the combined risks from SLR and TCs will continue to rise;however,SLRs will increase in intensity,and TCs will *** comprehensive risk of the Dongzhaigang mangroves posed by climate change will remain low under SSP1-2.6 and SSP2-4.5 scenarios by 2030,but it will increase substantially by *** under SSP5-8.5 scenario,the risks to mangroves in Dongzhaigang are projected to increase considerably by 2050,and approximately 68.8%of mangroves will be at very high risk by *** risk to the Dongzhaigang mangroves is not only influenced by the hazards but also closely linked to their exposure and *** therefore propose climate resilience developmental responses for mangroves to address the effects of climate *** study for the combined impact of TCs and SLR on mangroves in Dongzhaigang,China can enrich the method system of mangrove risk assessment and provide references for scientific management.

关键词： mangrove climate change risk assessment combined hazards sea level rise(SLR) tropical cyclones(TCs) resilience development Dongzhaigang China

非常规饲料原料日粮对肉牛生长性能、胴体性状、肉品质及经济效益的影响

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中国饲料 2021年第8期 105-108页

作者：司秀华王学恩青岛黄海学院山东青岛266427 阜新高等专科学校辽宁阜新123000

文章旨在评估不同非常规饲料原料替代浓缩料对肉牛生长性能、胴体性状及肉品质的影响。试验选择初始体重为(291.69±5.7)kg的肉牛80头,随机分为4组,每组20头,每头牛为1个重复。对照组肉牛在8周试验期每天自由采食水稻秸秆粗饲料并补充... 详细信息

文章旨在评估不同非常规饲料原料替代浓缩料对肉牛生长性能、胴体性状及肉品质的影响。试验选择初始体重为(291.69±5.7)kg的肉牛80头,随机分为4组,每组20头,每头牛为1个重复。对照组肉牛在8周试验期每天自由采食水稻秸秆粗饲料并补充基础浓缩料,处理组肉牛自由采食水稻秸秆粗饲料并分别补充用8%米糠、亚麻籽和葵花粕替代基础浓缩料混合物。结果:与米糠组相比,对照组和亚麻籽组肉牛的平均日增重分别显著提高10.74%和12.40%(P<0.05),同时米糠组肉牛的料重比较对照组和亚麻籽组分别显著提高11.69%和15.52%(P<0.05)。亚麻籽组肉牛的背膘厚度较对照组和米糠组分别显著提高7.84%和8.65%(P<0.05)。对照组肉牛眼肌C14:0脂肪酸含量显著低于处理组(P<0.05),而米糠组肉牛眼肌饱和脂肪酸含量较对照组显著提高16.55%(P<0.05),单不饱和脂肪酸含量显著降低11.95%(P<0.05)。亚麻籽和葵花粕组眼肌中蛋氨酸含量较对照组和米糠组分别显著提高168%、179.17%和154%、164.58%(P<0.05)。结论:在本研究条件下,用8%亚麻籽替代浓缩料饲喂肉牛可以提高肌肉蛋氨酸含量,对肉牛生长表现及肌肉脂肪酸组成无负面影响。

关键词：非常规原料肉牛生长性能胴体性状肉品质

TET1 Participates in Complete Freund’s Adjuvant-induced Trigeminal Inflammatory Pain by Regulating Kv7.2 in a Mouse Model

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Neuroscience Bulletin 2024年第6期40卷 707-718页

作者： Dengcheng Zhan Jingjing Zhang Songxue Su xiuhua Ren Sen Zhao Weidong Zang Jing Cao Department of Human Anatomy School of Basic Medical SciencesZhengzhou UniversityZhengzhou450001China Neuroscience Research Institute Zhengzhou UniversityZhengzhou450001China

Trigeminal inflammatory pain is one of the most severe pain-related disorders in humans;however,the underlying mechanisms remain largely *** this study,we investigated the possible contribution of interaction between ten-eleven translocation methylcytosine dioxygenase 1(TET1)and the voltage-gated K^(+)channel Kv7.2(encoded by Kcnq2)to orofacial inflammatory pain in *** found that complete Freund’s adjuvant(CFA)injection reduced the expression of Kcnq2/Kv7.2 in the trigeminal ganglion(TG)and induced orofacial inflammatory *** involvement of Kv7.2 in CFA-induced orofacial pain was further confirmed by Kv7.2 knockdown or ***,TET1 knockdown in Tet1^(flox/flox)mice significantly reduced the expression of Kv7.2 and M currents in the TG and led to pain-like ***,TET1 overexpression by lentivirus rescued the CFA-induced decreases of Kcnq2 and M currents and alleviated mechanical *** data suggest that TET1 is implicated in CFA-induced trigeminal inflammatory pain by positively regulating Kv7.2 in TG neurons.

关键词： Facial pain KCNQ2 potassium channel TET1 protein

Integrating Bimetallic Nanoparticles with Covalent Organic Frameworks as Multifunctional Nanozyme for Colorimetric Detection of Hydrogen Peroxide and Glutathione

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Journal of Analysis and Testing 2024年第3期8卷 278-287页

作者： Yuying Yuan Xiaoxue Xi Ting Bao Pingguan Bian Feng Pei xiuhua Zhang Shengfu Wang Wei Wen Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional MoleculesCollege of Chemistry and Chemical EngineeringHubei University Hubei Yihua Chemical Co. Ltd

The controllable growth of metal nanoparticles on nanomaterials is becoming an effective strategy for developing nanocomposites with designated performance. Herein, a simple and mild strategy for the in situ growth of Pt–Pd bimetallic nanoparticles on covalent organic frameworks（COFs） to regulate the nanozyme activity was designed for colorimetric detection of hydrogen peroxide（H2O2） and glutathione（GSH）. The COFs not only offer sufficient loading sites for the uniform dispersion of Pt–Pd bimetallic nanoparticles, but also increase the adsorption of substrate to promote the catalytic reaction. With the bimetallic synergistic effect of Pt–Pd nanoparticles, the prepared multifunctional nanozyme（Pt–Pd/COFs nanozyme） simultaneously exhibited superior peroxidase（POD）-like activity and oxidase（OXD）-like activity. Using the multifunctional nanozyme, a colorimetric sensing system was constructed for sensitive detection of H2O2and GSH, with the wide linear ranges of 5–1000 μmol/L and 1–40 μmol/L, and the detection limits were 1.14 μmol/L and 0.43 μmol/L, respectively. It was successfully used for the detection of real samples in environmental water and serum, providing a simple method for disease diagnosis and environmental monitoring.

关键词： Bimetallic synergistic effect H2O2 and GSH detection Oxidase-like activity Peroxidase-like activity Pt–Pd/COFs nanozyme

Spectral matching based remote sensing identification of two main crop rotation patterns in a large irrigation district

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中国水利水电科学研究院学报(中英文) 2024年

作者： DUAN Yuanyuan CHEN xiuhua LIU Jun YE Mao LU Wenjing LIU Hongjie China Institute of Water Resources and Hydropower Research Application Center of Remote Sensing Technology Research Center on Flood & Drought Disaster Prevention and Reduction of the Ministry of Water Resources Qingdao Comcore Technologies Co. Ltd Sucheng District Water Resources Bureau

Abstract:The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield *** this study,the OTSU algorithm and Mean-Shift algorithm were employed to automatically determine threshold values for mapping two main rotated crop patterns at the pixel scale.A time series analysis was conducted to extract the spatial distribution of rice-wheat and wheat-maize rotations in the Chuanhang irrigation district from 2016 to *** results demonstrate that both threshold segmentation algorithms are reliable in extracting the spatial distribution of the crops,with an overall accuracy exceeding 80%.Additionally,both Kappa coefficients surpass 0.7,indicating better performance by OTSU *** the period from 2016 to 2020,the area occupied by ricewheat rotation cropping ranged from 12 500 to 14 400 hm2;whereas wheat-maize rotation cropping exhibited smaller and more variable areas ranging from 19730 to 34070 *** findings highlight how remote sensing-based approaches can provide reliable support for rapidly and accurately identifying the spatial distribution of main crop rotation patterns within a large irrigation district.

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Mechanisms of tigecycline resistance in Gram-negative bacteria:A narrative review

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Engineering Microbiology 2024年第3期4卷 54-61页

作者： Wenya Su Wenjia Wang Ling Li Mengge Zhang Hai Xu Chengzhang Fu xiuhua Pang Mingyu Wang State Key Laboratory of Microbial Technology Microbial Technology InstituteShandong UniversityQingdao 266237PR China Helmholtz Institute for Pharmaceutical Research Saarland(HIPS) Helmholtz Centre for Infection Research(HZI)and Department of PharmacySaarland UniversitySaarbrücken 66123Germany

Tigecycline serves as a critical“final-resort”antibiotic for treating bacterial infections caused by multidrug-resistant bacteria for which treatment options are severely *** increasing prevalence of tigecycline resistance,particularly among Gram-negative bacteria,is a major *** mechanisms have been iden-tified as contributors to tigecycline resistance,including upregulation of nonspecific Resistance Nodulation Divi-sion(RND)efflux pumps due to mutations in transcriptional regulators,enzymatic modification of tigecycline by monooxygenase enzymes,and mutations affecting tigecycline binding *** review aims to consolidate our understanding of tigecycline resistance mechanisms in Gram-negative bacteria and offer insights and perspectives for further drug development.

关键词： Gram-negative bacteria Tigecycline Tigecycline resistance Resistance mechanisms RND efflux pump

Seasonal variation of melatonin secretion across various segments of the gastrointestinal tract in rats

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Journal of Traditional Chinese Medical Sciences 2024年第3期11卷 275-282页

作者： Yuxin Zhang Xuejie Huang Yilu Peng Yuxi Liang Wenjing Zhang Yadong Cui Xiaoying Xu xiuhua Hu Xiaoyan Liu School of Traditional Chinese Medicine Beijing University of Chinese MedicineBeijing 102488China School of Traditional Chinese Medicine Hebei UniversityBaoding 071000China School of Life Sciences Beijing University of Chinese MedicineBeijing 102488China

Objective To investigate whether melatonin(MT)secretion in different parts of the gastrointestinal tract(GIT)exhibits seasonal variations and its correlation with immune *** sixty Sprague-Dawley rats were divided into control and model groups,and the pineal gland was removed in the model ***,jejunum,ileum,and colon tissues were obtained during the spring equinox,summer solstice,beginning of autumn,autumn equinox,and winter *** levels of MT,MT receptors(MR),arylalkylamine N-acetyltransferase(AANAT),hydroxyindole-O-methyltransferase(HIOMT),interleukin-2(IL-2),and interleukin-10(IL-10)in the GIT were measured using enzyme-linked immunosorbent *** Except for the stomach,the jejunum,ileum,and the colon showed seasonal tendencies in MT *** the control group,MT secretion in the jejunum and ileum was the highest in the long summer,and colonic MT secretion was the highest in *** the model group,MT levels in the colon were highest in the *** seasonal rhythms of the MR,AANAT,HIOMT,IL-2,and IL-10 in the colon were roughly similar to those of MT,and changed accordingly after *** Gastrointestinal MT secretion is related to seasonal changes,and MT secretion in each intestinal segment is influenced by different *** biological effects of MT in the gut are inextricably linked to the mediation of MR,and a hormone-receptor linkage exists between MT and *** effect of seasonal changes on the gastrointestinal immune system may be mediated through the regulation of seasonal secretion of MT.

关键词： Melatonin Seasonal variations Pineal gland Gastrointestinal tract Melatonin receptors