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Chain Extender-induced Hydrogen Bonding Organization Determines the Morphology and Properties of Thermoplastic Polycarbonate Polyurethane

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Chinese Journal of Polymer Science 2024年第1期42卷 87-96,I0009页

作者： Yi-Lang Qin ping Zhu chen-xi Ouyang xia Dong Fuwai Hospital Chinese Academyof Medical Sciences&Peking Union Medical College/National Center for Cardiovascular DiseasesBejing 100037China CASKey Laboratoryof Engineering Plastics CAS Research/Education Centerfor Excellence in Molecular SciencesInstitute ofChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Thermoplastic polycarbonate polyurethanes(PCUs) are multiblock copolymers that have been applied for medical devices for long time. Aliphatic diols are common chain extenders(CE) involved in the composition of the hard segments of PCU. However, limited knowledge was discovered about how the chemical structure of CE affects the hydrogen bonding organization within PCUs and their mechanical *** investigate this problem, a group of PCUs were synthesized respectively by extending the polymer chain with 1,4-butanediol(BDO),aminoethanol(MEA), ethanediol(EO) as three kinds of chain extenders. Tiny differences in the CE chemical structure results in remarkable variations in phase separation, condensed morphologies, thermal and mechanical properties, which are characterized by Fourier transform infrared spectrometer, atomic force microscopy, small-angle X-ray scattering, differential scanning calorimetry, and tensile tests. The microstructural evolution during unilateral deformation and the different mechanism induced by the different CEs was probed and unveil by in situ wide-and small-angle X-ray diffraction. Symmetry of CE can improve the organization of the hydrogen bonding. The coherence strength of the urethane/urea group also plays a key role by comparing the two PCUs with ethanediol and aminoethanol.

关键词： Thermoplastic polycarbonate polyurethane Chain extender Hydrogen bonding Mechanical properties

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Citation analysis of meta-analysis articles on posttraumatic stress disorder

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Chinese Medical Journal 2011年第7期124卷 1088-1093页

作者： LIAO xi-ming chen ping-yan Department of Biostatistics School of Public Health and Tropical Medicine Southern Medical University Guangzhou Guangdong 510515 China

Background In the past two decades enormously scientific researches on posttraumatic stress disorder （PTSD） have been undertaken and many related meta-analyses have been published. Citation analysis was used to get comprehensive perspectives of meta-analysis articles （MA articles） on PTSD for the purpose of facilitating the researchers, ohvsicians and Policy-makers to understand the PTSD.

关键词： meta-analysis posttraumatic stress disorder bibliometric analysis

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Wave Attenuation and Turbulence Driven by Submerged Vegetation Under Current-Wave Flow

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China Ocean Engineering 2024年第4期38卷 602-611页

作者： HUANG Yu-ming Ding Lei WANG Yi-fei chen Ben YANG xiao-yu DOU xi-ping School of Water Resources and Hydropower Engineering Wuhan UniversityWuhan430072China Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China

A set of laboratory experiments are carried out to investigate the effect of following/opposing currents on wave *** vegetation canopies with aligned and staggered configurations were tested under the condition of various regular wave heights and current velocities,with the constant water depth being 0.60 m to create the desired submerged *** show that the vegetation-induced wave dissipation is enhanced with the increasing incident wave height.A larger velocity magnititude leads to a greater wave height attenuation for both following and opposing current ***,there is a strong positive linear correlation between the damping coefficientβand the relative wave height H_(0)/h,especially for pure wave *** the velocity profile,the distributions of U_(min)and U_(max)show different patterns under combined wave and *** time-averaged turbulent kinetic energy(TKE)vary little under pure wave and U_(c)=±0.05 m/s *** the increase of flow velocity amplitude,the time-averaged TKE shows a particularly pronounced increase trend at the top of the *** vegetation drag coefficients are obtained by a calibration *** empirical relations of drag coefficient with Reynolds and Keulegane-Carpenter numbers are proposed to further understand the wave-current-vegetation interaction mechanism.

关键词： wave attenuation rigid vegetation following and opposing currents turbulent kinetic energy

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Neutron Diffraction of Large-Volume Samples at High Pressure Using Compact Opposed-Anvil Cells

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Chinese Physics Letters 2018年第4期35卷 12-15页

作者： xiao-Lin Ni Lei-Ming Fang xin Li xi-ping chen Lei Duan-Wei He Zi-Li Kou Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 Key Laboratory of Neutron Physics and Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Mianyang 621999

Neutron diffraction techniques of large-volume samples at high pressure using compact opposed-anvil cells are developed at a reactor neutron source, China＇s Mianyang research reactor. We achieve a high-pressure condition of in situ neutron diffraction by means of a newly designed large-volume opposed-anvil cell. This pressure calibration is based on resistance measurements of bismuth and the neutron diffraction of iron. Pressure calibration experiments are performed at room temperature for a new cell using the tungsten carbide anvils with a tapered angle of 30°, Φ4.5 mm culet diameter and the metal-nonmetal composite gasket with a thickness of 2 mm. Transitions in Bi（Ⅰ–Ⅱ 2.55 GPa, Ⅱ–V 7.7 GPa） are observed at 100 and 300 kN, respectively, by resistance *** pressure measurement results of neutron diffraction are consistent with resistance measurements of *** a result, pressures up to about 7.7 GPa can routinely and stably be achieved using this apparatus, with the sample volume of 9 mm^3.

关键词： Neutron Diffraction of Large-Volume Samples at High Pressure Using Compact Opposed-Anvil Cells

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The design of 2/8-type high-pressure cell applied to in situ neutron diffraction

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Chinese Physics B 2019年第7期28卷 188-192页

作者： Chun-Jiang xiang Qi-Wei Hu Qiang Wang Lei xie xi-ping chen Lei-Ming Fang Duan-Wei He Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China Key Laboratory of Neutron Physics and Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Mianyang 621999 China

The DIA-type Kawai cell possesses a larger volume and a quasi-hydrostatic pressure environment and has been widely used in materials’ synthesis and x-ray diffraction ***, few high-pressure in situ neutron diffraction experiments were performed in the DIA-type Kawai cell because there is no wide window for neutron diffraction and the second-stage anvils and guild block material attenuates the neutron signal *** this work, we tentatively modified the normal DIA-type Kawai cell(MA 2-6-8) into a MA 2-8 mode by removing the six first-stage tungsten carbide *** a consequence, the eight tungsten carbide anvils(Kawai cell) are directly driven by the guide *** results of ex situ and in situ pressure calibration show that the cell pressure can reach 5 GPa with small truncation edge lengths(TEL) of 3 mm even at the load of 300 *** suggests that this MA 2-8 cell may open a new way for high-pressure and high-temperature in situ neutron diffraction.

关键词： DIA-type apparatus Kawai-type cell in situ neutron diffraction

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Noninvasive Diagnostic Technique for Nonalcoholic Fatty Liver Disease Based on Features of Tongue Images

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Chinese Journal of Integrative Medicine 2024年第3期30卷 203-212页

作者： WANG Rong-rui chen Jia-liang DUAN Shao-jie LU Ying-xi chen ping ZHOU Yuan-chen YAO Shu-kun Graduate School of Beijing University of Chinese Medicine Beijing100029China Department of Gastroenterology China-Japan Friendship HospitalBeijing100029China Center of Integrative Medicine Beijing Ditan HospitalCapital Medical UniversityBeijing100015China Nanjing Linkwah Micro-electronics Institute Beijing100191China Institute of Microelectronics Tsinghua UniversityBeijing100084China Peking University China-Japan Friendship School of Clinical Medicine Beijing100029China

Objective:To investigate a new noninvasive diagnostic model for nonalcoholic fatty liver disease(NAFLD) based on features of tongue ***:Healthy controls and volunteers confirmed to have NAFLD by liver ultrasound were recruited from China-Japan Friendship Hospital between September 2018 and May 2019,then the anthropometric indexes and sampled tongue images were *** tongue images were labeled by features,based on a brief protocol,without knowing any other clinical data,after a series of corrections and data *** algorithm was trained on images using labels and several anthropometric indexes for inputs,utilizing machine learning ***,a logistic regression algorithm and a decision tree model were constructed as 2 diagnostic models for ***:A total of 720 subjects were enrolled in this study,including 432 patients with NAFLD and 288 healthy *** them,482 were randomly allocated into the training set and 238 into the validation *** diagnostic model based on logistic regression exhibited excellent performance:in validation set,it achieved an accuracy of 86.98%,sensitivity of 91.43%,and specificity of 80.61%;with an area under the curve(AUC) of 0.93 [95% confidence interval(CI) 0.68–0.98].The decision tree model achieved an accuracy of 81.09%,sensitivity of 91.43%,and specificity of 66.33%;with an AUC of 0.89(95% CI 0.66–0.92) in validation ***:The features of tongue images were associated with *** the 2 diagnostic models,which would be convenient,noninvasive,lightweight,rapid,and inexpensive technical references for early screening,can accurately distinguish NAFLD and are worth further study.

关键词： nonalcoholic fatty liver disease noninvasive diagnosis tongue image tongue diagnosis Chinese medicine machine learning

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A review of the neurotransmitter system associated with cognitive function of the cerebellum in Parkinson's disease

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Neural Regeneration Research 2024年第2期19卷 324-330页

作者： xi chen Yuhu Zhang Department of Neurology Guangdong Neuroscience InstituteGuangdong Provincial People’s Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouGuangdong ProvinceChina Shantou University Medical College ShantouGuangdong ProvinceChina

The dichotomized brain system is a concept that was generalized from the‘dual syndrome hypothesis’to explain the heterogeneity of cognitive impairment,in which anterior and posterior brain systems are independent but partially *** dopaminergic system acts on the anterior brain and is responsible for executive function,working memory,and *** contrast,the cholinergic system acts on the posterior brain and is responsible for semantic fluency and visuospatial *** from dopaminergic/cholinergic imaging or functional neuroimaging has shed significant insight relating to the involvement of the cerebellum in the cognitive process of patients with Parkinson’s *** research has reported evidence that the cerebellum receives both dopaminergic and cholinergic ***,whether these two neurotransmitter systems are associated with cognitive function has yet to be fully ***,the precise role of the cerebellum in patients with Parkinson’s disease and cognitive impairment remains ***,in this review,we summarize the cerebellar dopaminergic and cholinergic projections and their relationships with cognition,as reported by previous studies,and investigated the role of the cerebellum in patients with Parkinson’s disease and cognitive impairment,as determined by functional *** findings will help us to understand the role of the cerebellum in the mechanisms underlying cognitive impairment in Parkinson’s disease.

关键词： anterior brain system cerebellum cholinergic cognitive impairment dopaminergic dual syndrome hypothesis neuroimage neurotransmitter Parkinson’s disease posterior brain system therapeutic targets

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Bio-screening and quantification of methyl paraben in vinegar and coconut juice separated by HPTLC

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Food Science and Human Wellness 2024年第3期13卷 1602-1607页

作者： Yisheng chen xingjun xi College of Food Science and Engineering Shanxi Agricultural UniversityTaigu 030801China Insitute of Food Nutrition and Safety Shanxi Agricultural UniversityTaiyuan 030031China Institute of Agricultural Food Standardization China National Institute of StandardizationBeijing 100191China

As a widely used food preservative,methyl paraben was experimentally evidenced with serious hormonelike adverse ***,a high performance thin-layer chromatography platformed bioluminescent bioautography and image analysis for the selective quantification and confirmation of methyl paraben was proposed and validated in vinegar and coconut ***,the detectability of the bioautography to the analyte on different layer materials was estimated,revealing that normal silica gel was the best *** that,the liquid of sample extract and working solution were separated to overcome the background noises due to co-extracted *** separation result was then coupled to the optimized bioautography,enabling instant and straightforward screening of the targeted *** accurate quantification,bioluninescent inhibition pattern caused by the analyte was processed by image analysis,giving useful sensitivity(LOD>16 mg/kg),precision(RSD<10.1%)and accuracy(spike-recovery rate 76.9%-112.2%).Finally,the suspected result was confirmed by determining its MS fingerprint,further strengthening the reliability of screening.

关键词： High performance thin-layer chromatography Bio-screening Bioluminescence Image analysis Methyl paraben

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An extended numerical model of the first exothermic peak for three dimensional printed cement-based materials

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 80-88页

作者： Wei JIANG Wenqian LI xi chen School of Materials Science and Engineering Tongji UniversityShanghai 200092China School of Civil Engineering Tongji UniversityShanghai 200092China

The first exothermic peak of cement-based material occurs a few minutes after mixing,and the properties of three dimensional(3D)printed concrete,such as setting time,are very sensitive to *** this background,based on the classical Park cement exothermic model of hydration,we propose and construct a numerical model of the first exothermic peak,taking into account the proportions of C_(3)S,C_(3)A and quicklime in *** calculated parameters are calibrated by means of relevant published exothermic test *** is found that this developed model offers a good simulation of the first exothermic peak of hydration for C_(3)S and C_(3)A proportions from 0 to 100% of cement clinker and reflects the effect of quicklime content at 8%-10%.The unique value of this research is provision of an important computational tool for applications that are sensitive to the first exothermic peak of hydration,such as 3D printing.

关键词： 3D printed cement-based materials cement hydration the first exothermic peak liquid quick-setting agent numerical model

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Mismatch negativity,social cognition,and functional outcomes in patients after traumatic brain injury

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Neural Regeneration Research 2015年第4期10卷 618-623页

作者： Hui-yan Sun Qiang Li xi-ping chen Lu-yang Tao Department of Forensic Medicine Soochow University Department of Forensic Medicine Chifeng University

Mismatch negativity is generated automatically, and is an early monitoring indicator of neuronal integrity impairment and functional abnormality in patients with brain injury, leading to decline of cognitive function. Antipsychotic medication cannot affect mismatch negativity. The present study aimed to explore the relationships of mismatch negativity with neurocognition, daily life and social functional outcomes in patients after brain injury. Twelve patients with traumatic brain injury and 12 healthy controls were recruited in this study. We examined neurocogni-tion with the Wechsler Adult Intelligence Scale-Revised China, and daily and social functional outcomes with the Activity of Daily Living Scale and Social Disability Screening Schedule, re-spectively. Mismatch negativity was analyzed from electroencephalogram recording. The results showed that mismatch negativity amplitudes decreased in patients with traumatic brain injury compared with healthy controls. Mismatch negativity amplitude was negatively correlated with measurements of neurocognition and positively correlated with functional outcomes in patients after traumatic brain injury. Further, the most signiifcant positive correlations were found be-tween mismatch negativity in the fronto-central region and measures of functional outcomes. The most signiifcant positive correlations were also found between mismatch negativity at the FCz electrode and daily living function. Mismatch negativity amplitudes were extremely positive-ly associated with Social Disability Screening Schedule scores at the Fz electrode in brain injury patients. These experimental ifndings suggest that mismatch negativity might efifciently relfect functional outcomes in patients after traumatic brain injury.

关键词： nerve regeneration brain injury cognition disorders diagnostic techniques Wechsler Intelligence Scale event-related potential neuronal plasticity electrophysiology neuropsychology activity of daily living work capacity evaluation electroencephalogram neural regeneration NSFC grant

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