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Syntheses and properties of associative acrylamide copolymers containing short hydrophobic chains used in a friction reducer for slick-water fracturing

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Petroleum Science 2024年第3期21卷 1889-1901页

作者： Ya-xing Dai xian-Li zhang Si-Yuan liu Feng-Run-Ze zhang Yi-xi zhang Yu-Tong Sang Jing-xi Zheng Zhao-Sheng liu Peng zhang College of Chemistry and Chemical Engineering Chongqing University of Science and TechnologyChongqing401331China College of Ecology and Environment Chongqing Resources and Environmental Protection of UniversityChongqing401331China China china Property Project department of Dezhou Mining Property Service CenterShengli Oilfield Company of SinopecDezhou253000ShandongChina

Two allyldimethylalkyl quaternary ammonium salt(AQAS)monomers,N,N-dimethylallylphenylpropylammonium bromide(AQAS1)and N,N-dimethylallylnonylammonium bromide(AQAS2.,were synthesized and used to prepare modified polyacrylamide *** new drag reducers were synthesized from acrylamide(AM),sodium acrylate(Na AA)and a cationic modified monomer(AQAS1 or AQAS2.via aqueous solution polymerization,and the copolymers were named P(AM/Na AA/AQAS1)and P(AM/Na AA/AQAS2.,*** structures of the drag reduction agents were confirmed by IR and1H NMR *** molecular weight(Mw)of P(AM/Na AA/AQAS1)was 1.79×10^(6)g/*** the copolymer concentration was 1000 mg/L and the flow rate was 45 L/min,in fresh water the highest drag reduction rate was 75.8%,in 10,000 mg/L Na Cl solution the drag reduction rate decreased to 72.9%.The molecular weight of P(AM/Na AA/AQAS2.was 3.17×10^(6)g/*** the copolymer concentration was500 mg/L and the flow rate was 45 L/min,the drag reduction rate reached 75.2.,and in 10,000 mg/L Na Cl solution the drag reduction rate was 73.3%,decreased by approximately 1.9%.The drag reduction rate for partially hydrolyzed polyacrylamide(HPAM)was also investigated,and the results showed that the drag reduction rates for 500 and 1000 mg/L HPAM solutions were merely 43.2.and 49.0%in brine,*** with HPAM,both of the above copolymers presented better drag reduction capacities.

关键词： Shale gas Slick water Drag reducer Modified monomer Copolymerization

A hybrid mean value related to the Dedekind sums and Kloosterman sums

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Science china mathematics 2010年第9期53卷 2543-2550页

作者： zhang wenpeng & liu yanni department of mathematics,northwest University,{2.,china 1. department of mathematics Northwest University Xi’an 710127 China

The main purpose of this paper is using the properties of character sum and the analytic method to study a hybrid mean value problem related to the Dedekind sums and Kloosterman sums,and give some interesting mean val... 详细信息

关键词： Dedekind sum Kloosterman sums Hybrid mean value asymptotic formula identity

Recent Development of Heat Transfer and Fluid Flow of Supercritical CO2.in Tubes:Mechanisms and Applications

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Journal of Thermal Science 2024年第06期33卷 2274-2298页

作者： zhang xirui SHAO Qihan liu Jian xi Wenxiong liu Chaoyang SUNDEN Bengt Research Institute of Aerospace Technology Central South University College of Aerospace Science and Engineering National University of Defense Technology department of Energy Sciences Lund University

With the advantages of low cost,excellent ability of heat and mass transfer and easy accessibility to the supercritical point,supercritical CO2.as been applied in many engineering devices *** of the sharply-varying thermophysical properties near the supercritical point,heat transfer and flow behavior of supercritical CO2.n tubes become complex and have received a lot of research *** main purpose of this paper is to summarize the findings of the published works related to flow phenomena and heat transfer characteristics of supercritical ***,influence parameters related to boundary conditions of supercritical CO2.lowing in a smooth tube are ***,commonly-used turbulence and mathematic models dealing with internal flows of supercritical CO2.re ***,research works on geometric effects of design parameters,shapes and configurations are *** practical applications of supercritical CO2.n recent years are ***,developments and future challenges of supercritical CO2.n tubes are analyzed and *** paper provides basic knowledge of heat transfer and fluid flow mechanisms and related practical applications of supercritical CO2.n tubes.

关键词： developments and challenges flow behavior heat transfer practical applications supercritical CO2

Pyruvate kinase M in germ cells is essential for sperm motility and male fertility but not spermatogenesis

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Asian Journal of Andrology 2024年第2期26卷 212-219页

作者： Gao-Qing Qian xiao-Chen Wang xi zhang Bin Shen Qiang liu State Key Laboratory of Reproductive Medicine and Offspring Health Nanjing Medical UniversityNanjing 211166China Shanghai Key Laboratory of Reproductive Medicine Department of HistoembryologyGenetics and Developmental BiologyShanghai Jiao Tong University School of MedicineShanghai 200025China State Key Laboratory of Molecular Biology Shanghai Key Laboratory of Molecular AndrologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghai 200031China

Male germ cells employ specific metabolic pathways throughout their developmental *** a previous study,we discovered heightened expression of pyruvate kinase M(PKM),a pivotal glycolytic enzyme,in spermatogonia and *** gain deeper insights into PKM's roles in spermatogenesis,sperm function,and male fertility,we engineered a conditional-knockout mouse model(Pkm-vkO mice)to selectively disrupt the Pkm gene within germ *** maintaining regular testicular histology and sperm morphology,the male Pkm-vko mice were infertility,characterized by significant impairments in sperm motility and adenosine triphosphate(ATP)*** addition,Pkm-null spermatozoa exhibited similar deficits in protein tyrosine phosphorylation linked to capacitation,as well as compromised performance in in vitro fertilization *** conclude,PKM's presence is not obligatory for the entirety of spermatogenesis in male germ cells;however,it emerges as a critical factor influencing sperm motility and overall male fertility.

关键词： glycolysis male fertility pyruvate kinase M sperm motility spermatogenesis

Single-Cell Mapping of Brain Myeloid Cell Subsets Reveals Key Transcriptomic Changes Favoring Neuroplasticity after Ischemic Stroke

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Neuroscience Bulletin 2024年第1期40卷 65-78页

作者： Fangxi liu xi Cheng Chuansheng Zhao xiaoqian zhang Chang liu Shanshan Zhong Zhouyang liu xinyu Lin Wei Qiu xiuchun zhang department of Neurology.The First Affiliated Hospital of china Medical University Shenyang 110001China department of Neurology The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510630China Stroke Center The First Affiliated Hospital of China Medical UniversityShenyang 110001China

Interactions between brain-resident and periph-eral infiltrated immune cells are thought to contribute to neuroplasticity after cerebral ***,con-ventional bulk sequencing makes it challenging to depict this complex immune *** single-cell RNA sequencing,we mapped compositional and transcriptional features of peri-infarct immune *** were the predominant cell type in the peri-infarct region,displaying a more diverse activation pattern than the typical pro-and anti-inflammatory state,with axon tract-associated micro-glia(ATMs)being associated with neuronal *** inference suggested that infiltrated monocyte-derived macrophages(MDMs)exhibited a gradual fate trajectory transition to activated ***-cellular crosstalk between MDMs and microglia orchestrated anti-inflammatory and repair-promoting microglia phenotypes and promoted post-stroke neurogenesis,with SOX2.and related Akt/CREB signaling as the underlying *** description of the brain's immune landscape and its relationship with neurogenesis provides new insight into promoting neural repair by regulating neuroinflammatory responses.

关键词： Ischemic stroke Monocyte-derived macrophage Microglia Neurogenesis Single-cell sequencing

Effect of aspect ratio of elliptical stirred vessel on mixing time and flow field characteristics in the absence of baffles

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Chinese Journal of Chemical Engineering 2024年第1期65卷 63-74页

作者： Yuan Yao Peiqiao liu Qian zhang Zequan Li Benjun xi Changyuan Tao Yundong Wang Zuohua liu School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China Hubei Three Gorges Laboratory Yichang 443007China department of Chemical Engineering Tsinghua UniversityBeijing 100084China

Elliptical tanks were used as an alternative to circular tanks in order to improve mixing efficiency and reduce mixing time in unbaffled stirred tanks(USTs). Five different aspect ratios of elliptical vessels were designed to compare their mixing time and flow field. Computational fluid dynamics(CFD) simulations were performed using the k–ε model to calculate the mixing time and simulate turbulent flow field features, such as streamline shape, velocity distribution, vortex core region distribution, and turbulent kinetic energy(TKE) transfer. Visualization was also carried out to track the tinctorial evolution of the liquid phase. Results reveal that elliptical stirred tanks can significantly improve mixing performance in USTs. Specifically, the mixing time at an aspect ratio of 2.00 is only 45.3% of the one of a circular stirred tank. Furthermore, the secondary flow is strengthened and the vortex core region increases with the increase of aspect ratio. The axial velocity is more sensitive to the aspect ratio than the circumferential and radial velocity. Additionally, the TKE transfer in elliptical vessels is altered. These findings suggest that elliptical vessels offer a promising alternative to circular vessels for enhancing mixing performance in USTs.

关键词： Mixing time CFD Stirred tank Secondary flow Mixing performance

Atorvastatin, etanercept and the nephrogenic cardiac sympathetic remodeling in chronic renal failure rats

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Journal of Geriatric Cardiology 2024年第4期21卷 443-457页

作者： Jing-Yue XU Zheng-Kai XUE Ya-Ru zhang xing liu Xue zhang xi YANG Tong liu Kang-Yin CHEN Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease Department of CardiologyTianjin Institute of Cardiologythe Second Hospital of Tianjin Medical UniversityTianjinChina

BACKGROUND Chronic renal failure(CRF) patients are predisposed to arrhythmias, while the detailed mechanisms are unclear. We hypothesized the chronic inflammatory state of CRF patients may lead to cardiac sympathetic remodeling, increasing the incidence of ventricular arrhythmia(VA) and sudden cardiac death. And explored the role of atorvastatin and etanercept in this *** A total of 48 rats were randomly divided into sham operation group(Sham group), CRF group, CRF + atorvastatin group(CRF + statin group), and CRF + etanercept group(CRF + rhTNFR-Fcgroup). Sympathetic nerve remodeling was assessed by immunofluorescence of growth-associated protein 43(GAP-43) and tyrosine hydroxylase positive area fraction. Electrophysiological testing was performed to assess the incidence of VA by assessing the ventricular effective refractory period and ventricular fibrillation threshold. The levels of tumor necrosis factor-alpha(TNF-α) and interleukin-1beta were determined by Western blotting and enzyme-linked immunosorbent *** Echocardiogram showed that compared with the Sham group, left ventricular end-systolic diameter and ventricular weight/body weight ratio were significantly higher in the CRF group. Hematoxylin-eosin and Masson staining indicated that myocardial fibers were broken, disordered, and fibrotic in the CRF group. Western blotting, enzyme-linked immunosorbent assay,immunofluorescence and electrophysiological examination suggested that compared with the Sham group, GAP-43 and TNF-α proteins were significantly upregulated, GAP-43 and tyrosine hydroxylase positive nerve fiber area was increased, and ventricular fibrillation threshold was significantly decreased in the CRF group. The above effects were inhibited in the CRF + statin group and the CRF + *** In CRF rats, TNF-α was upregulated, cardiac sympathetic remodeling was more severe, and the nephrogenic cardiac sympathetic remodeling existed. Atorvastatin and etanercept c

关键词： remodeling cardiac inhibited

Review on Lithium-ion Battery PHM from the Perspective of Key PHM Steps

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Chinese Journal of Mechanical Engineering 2024年第4期37卷 1-22页

作者： Jinzhen Kong Jie liu Jingzhe Zhu xi zhang Kwok-Leung Tsui Zhike Peng Dong Wang School of Mechanical Engineering Hebei University of TechnologyTianjin 300401China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Grado department of Industrial and Systems Engineering Virginia Polytechnic Institute and State UniversityBlacksburg 24061USA School of Mechanical Engineering Ningxia UniversityNingxia 750021China

Prognostics and health management(PHM)has gotten considerable attention in the background of Industry *** PHM contributes to the reliable and safe operation of electric ***,relevant reviews are still continuously updated over *** this paper,we browsed extensive literature related to battery PHM from 2.18to 2.2. and summarized advances in battery PHM field,including battery testing and public datasets,fault diagnosis and prediction methods,health status estimation and health management *** last topic includes state of health estimation methods,remaining useful life prediction methods and predictive maintenance *** of these categories is introduced and discussed in *** on this survey,we accordingly discuss challenges left to battery PHM,and provide future research *** research systematically reviews recent research about battery PHM from the perspective of key PHM steps and provide some valuable prospects for researchers and practitioners.

关键词： Lithium-ion batteries Prognostics and health management Remaining useful life State of health Predictive maintenance

Clinical efficacy and identification of factors confer resistance to afatinib(tyrosine kinase inhibitor)in EGFR-overexpressing esophageal squamous cell carcinoma

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Signal Transduction and Targeted Therapy 2024年第7期9卷 3130-3140页

作者： yanni Wang Chang liu Huan Chen xi Jiao Yujiao Wang Yanshuo Cao Jian Li xiaotian {2. Yu Sun Na Zhuo Fengxiao Dong Mengting Gao Fengyuan Wang Liyuan Dong Jifang Gong Tianqi Sun Wei Zhu Henghui {2. Lin Shen Zhihao Lu Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Department of Gastrointestinal OncologyPeking University Cancer Hospital and InstituteBeijingChina Genecast Biotechnology Co. LtdWuxiPR China State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers Beijing Key Laboratory of Carcinogenesis and Translational ResearchDepartment of Gastrointestinal OncologyPeking University Cancer Hospital and InstituteBeijingChina Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education) Department of PathologyPeking University Cancer Hospital and InstituteBeijingChina Precision Scientific(Beijing)Co. Ltd.BeijingChina Generulor Company Bio-X Lab ZhuhaiGuangdongChina Biomedical Innovation Center Beijing Shijitan HospitalCapital Medical UniversityBeijingChina Beijing Key Laboratory for Therapeutic Cancer Vaccines Beijing Shijitan HospitalCapital Medical UniversityBeijingChina

Epidermal growth factor receptor(EGFR)is reportedly overexpressed in most esophageal squamous cell carcinoma(ESCC)patients,but anti-EGFR treatments offer limited survival *** preclinical data showed the promising antitumor activity of afatinib in EGFR-overexpressing *** proof-of-concept,phase II trial assessed the efficacy and safety of afatinib in pretreated metastatic ESCC patients(n=41)with EGFR overexpression(NCT03940976).The study met its primary endpoint,with a confirmed objective response rate(ORR)of 39%in 38 efficacy-evaluable patients and a median overall survival of 7.8 months,with a manageable toxicity *** analysis of pretreatment tumors revealed that neurotrophic receptor tyrosine kinase 2.NTRK2.was negatively associated with afatinib sensitivity and might serve as a predictive biomarker,irrespective of EGFR ***,knocking down or inhibiting NTRK2.sensitized ESCC cells to afatinib *** study provides novel findings on the molecular factors underlying afatinib resistance and indicates that afatinib has the potential to become an important treatment for metastatic ESCC patients.

关键词： esophageal squamous expressing