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Effects of Structural Changes in Subchondral Bone on Articular Cartilage in a Beagle Dog Model

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Biomedical and Environmental Sciences 2017年第3期30卷 194-203页

作者： YAN Dong LIU Tong Xi LIU Bao Yue WANG Ling QIAN Zhan Hua cheng xiao guang LI Kun cheng Department of Radiology Xuanwu HospitalCapital Medical UniversityBeijing 100053China Department of Radiology Beijing Jishuitan HospitalFourth Clinical Hospital of Peking University Health ScienceCenterBeijing 100035China Department of Pathology Beijing Jishuitan HospitalFourth Clinical Hospital of Peking University Health Science CenterBeijing 100035China

Objective Using MR T2-mapping and histopathologic score for articular cartilage to evaluate the effect of structural changes in subchondral bone on articular cartilage. Methods Twenty-four male Beagle dogs were randomly divided into a subchondral bone defect group （n = 12） and a bone cement group （n = 12）. Models of subchondral bone defectin the medial tibial plateau and subchondral bone filled with bone cement were constructed. In all dogs, the left knee joint was used as the experimental sideand the right knee as the sham side. The T2 value for articular cartilage at the medial tibial plateau was measured at postoperative weeks 4, 8, 16, and 24. The articular cartilage specimens were stained with hematoxylin and eosin, and evaluated using the Mankin score. Results There was a statistically significant difference （P 〈 0.05） in Mankin score between the bone defect group and the cement group at postoperative weeks 16 and 24. There was a statistically significant difference in the T2 values between the bone defect group and its sham group （P 〈 0.05） from week 8, and between the cement group and its sham group （P 〈 0.05） from week 16. There was significant difference in T2 values between the two experimental groups at postoperative week 24 （P 〈 0.01）. The T2 value for articular cartilage was positively correlated with the Mankin score （ρ = 0.758, P 〈 0.01）. Conclusion Structural changes in subchondral bone can lead to degeneration of the adjacent articular cartilage. Defects in subchondral bone cause more severe degeneration of cartilage than subchondral bone filled with cement. The T2 value for articular cartilage increases with the extent of degeneration. MR T2-mapping images and the T2 value for articular cartilage can indicate earlycartilage degeneration.

关键词： MR T2-mapping Subchondral bone Articular cartilage Degeneration

Magnetic Resonance Imaging and Histopathological Analysis of Experimental Muscle Injuries in a Rabbit

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Biomedical and Environmental Sciences 2013年第10期26卷 841-848页

作者： YAN Dong ZHANG Jing LIANG Wei SUN Jing LIU Bao Yue TIAN Wei cheng xiao guang Department of Radiology Beijing Jishuitan Hospital Fourth Clinical Hospital of Peking University Health Science Center

Objective To investigate the correlation of magnetic resonance imaging （MRI） with histopathologica changes, and to evaluate T2 mapping in assessing muscle trauma in a rabbit model of muscle injury. Methods We divided 35 rabbits into seven groups that each represented a different time point after intramuscular hemorrhage and muscle injury. Hemorrhage was created by injecting autologous blood into the left legs, and muscle injury was created by scalpel incision of the biceps femoris of the right legs. At different time points, the rabbits underwent Tl-weighted imaging and T2-weighted imaging （TzWl and T2Wl） and T2 mapping. T2 relaxation times were measured, and the corresponding samples were evaluated for pathological changes. Results After 2 h, the intramuscular hemorrhage model demonstrated an increased signal intensity on both TlWl and T2Wl. Histological examination showed erythrocytes within the muscle bundle. On days 1 and 3, the MRI signals were decreased, and there were no significant changes after day 7. From 2 h to 3 days, the muscle-injury model showed a high signal on both TzWl and T2Wl. Corresponding pathological changes included rupture and edema of muscle fibers, and inflammation. The abnormal signals were reduced on day 7. After day 14, the T2Wl intensity remained high. TlWl showed no abnormal changes, but some models showed a high signal, representing fresh bleeding and fatty tissue. T2 relaxation times were significantly different between the central and marginal regions, and between the marginal and normal regions. Conclusion MRI clearly demonstrates intramuscular hemorrhage and muscle injury, which correlate well with histopathological changes. Tz mapping is useful in assessing the extent of injury.

关键词： Muscle injury Intramuscular hemorrhage Magnetic resonance imaging T2 mapping

Solitary pulmonary nodules： comparison of multi-slice computed tomography perfusion study with vascular endothelial growth factor and microvessel density

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Chinese Medical Journal 2009年第5期122卷 541-547页

作者： BAI Rong-jie cheng xiao-guang QU Hui SHEN Bao-zhong HAN Ming-jun WU Zhen-hua Department of Radiology Beijing Jishuitan Hospital Peking University Beijing 100035 China Department of Radiology Fourth Affiliated Hospital of Harbin Medical University Harbin Heilongjiang 150001 China Department of Radiology First Affiliated Hospital of China Medical University Shenyang Liaoning 110001 China Department of Radiology Second Affiliated Hospital of China Medical University Shenyang Liaoning 110004 China

Background The solitary pulmonary nodule （SPN） is one of the most common findings on chest radiographs. The objectives of clinical practice are to differentiate malignant nodules from benign nodules in the least invasive way and to make a specific diagnosis. This study was aimed to evaluate the correlation between perfusion imaging features and microvessel density （MVD） and vascular endothelial growth factors （VEGF） in SPNs using multi-slice computed tomography （MSCT）; and to provide the theoretical basis for SPN blood flow pattern and blood flow quantitative features. Also, the study called for the discussion of the method＇s clinical application value in the differential diagnosis of benign and malignant *** Sixty-eight patients with SPN underwent multi-location dynamic contrast enhanced （nonionic contrast material was administrated via the antecubital vein at a rate of 4 ml/s） MSCT. Precontrast and postcontrast attenuations on every scan was studied. Perfusion, peak height, and the ratio of the peak height of the SPN to that of the aorta were analyzed. Perfusion was calculated using the maximum gradient of the time-density curves （TDC） and the peak height of the aorta. The quantitative parameters （perfusion, peak height, ratio of peak height of the SPN to that of the aorta） of the blood flow pattern were compared with MVD and the VEGF expression of immunohistochemistry. Results The perfusion peak heights of malignant （（96.15±11.55） HU） and inflammatory （（101.15±8.41） HU） SPNs were significantly higher than those of benign （（47.24±9.15） HU） SPNs （P 〈0.05, P 〈0.05）. Ratios of SPN-to-aorta of malignant and inflammatory SPNs were significantly higher than those of benign SPNs （P 〈0.05, P 〈0.05）. No significant differences were found between the peak height and SPN-to-aorta ratio of malignant SPNs and inflammatory SPNs （P 〉0.05, P 〉0.05）. The precontrast densities of inflammatory SPNs were lower than those of malignant SPNs （P 〈0.05）. Perfusion values of malig

关键词： coin lesion, pulmonary regional blood flow noevascularization, pathologic endothelial growth factors tomography, X-ray computed

定量CT测量不同层面腰部椎后肌群体质成分的差异及相关性研究

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中国骨与关节杂志 2024年第2期13卷 113-117页

作者：李新彤姚宁蔡韦王玲程晓光首都医科大学附属北京积水潭医院放射科北京100035

目的探讨腰部椎后肌群体质成分在L3及L5椎体层面的差异及相关性。方法对659名21~60岁的志愿者进行腰椎CT检查,包括276名男性及383名女性。使用定量CT获得L3及L5椎体层面椎后肌群的肌肉横截面积(cross-sectional muscle area,CSMA)、肌... 详细信息

目的探讨腰部椎后肌群体质成分在L3及L5椎体层面的差异及相关性。方法对659名21~60岁的志愿者进行腰椎CT检查,包括276名男性及383名女性。使用定量CT获得L3及L5椎体层面椎后肌群的肌肉横截面积(cross-sectional muscle area,CSMA)、肌间隙脂肪面积(intra-muscular adipose area,IMAA)及肌肉脂肪浸润程度(muscle fat infiltration,MFI)。使用独立样本t检验比较男女间椎后肌群的差异。使用配对样本t检验比较两个层面椎后肌群的差异。使用person相关及线性回归分析L3、L5层面椎后肌群体质成分的相关关系。结果男性L3及L5层面椎后肌群CSMA大于女性(t=27.905、7.450,P<0.001),而MFI小于女性(t=-9.091、-11.755,P<0.001)。L3层面椎后肌群CSMA大于L5层面(t=55.850,P<0.001),而IMAA及MFI小于L5层面(t=-34.788、-57.774,P<0.001)。L3及L5层面的CSMA(r男性=0.459、r女性=0.365,P<0.01)、IMAA(r男性=0.336、r女性=0.325,P<0.01)、MFI(r男性=0.421、r女性=0.455,P<0.01)分别呈正相关,且回归方程均有统计学意义(P<0.001)。结论L3及L5层面椎后肌群体质成分存在差异及相关性,测量层面在必要时可以进行替代。

关键词：肌减少症腰椎锥束计算机体层摄影术综合征

负重位与平卧位磁共振成像对腰椎前凸的对比研究

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中国骨与关节杂志 2024年第8期13卷 596-600页

作者：李凯李新彤过哲徐黎冯强强程晓光首都医科大学附属北京积水潭医院放射科北京100035

目的比较负重位磁共振成像(magnetic resonance imaging,MRI)与平卧位MRI评估腰椎前凸的价值。方法回顾分析24例腰痛患者分别行负重位和平卧位MRI检查,测量腰椎Cobb’s角、四线Cobb’s角、腰骶角、腰椎高度、腰椎前凸距离、腰椎前凸角... 详细信息

目的比较负重位磁共振成像(magnetic resonance imaging,MRI)与平卧位MRI评估腰椎前凸的价值。方法回顾分析24例腰痛患者分别行负重位和平卧位MRI检查,测量腰椎Cobb’s角、四线Cobb’s角、腰骶角、腰椎高度、腰椎前凸距离、腰椎前凸角度等参数,配对样本t检验或Wilcoxon符号秩和检验比较差异。结果24例中,腰椎负重位MRI与腰椎平卧位MRI的腰椎Cobb’s角[(31.05±13.65)°vs.(27.95±11.81)°]、腰椎前凸距离[(2.32±0.75)cm vs.(1.96±0.75)cm]、腰椎前凸角度[(34.58±11.90)°vs.(30.51±11.14)°]、腰椎高度[(16.66±1.34)cm vs.(16.80±1.08)cm]之间差异有统计学意义(腰椎Cobb’s角,t=2.647,P=0.014;腰椎前凸距离,t=8.141,P<0.001;腰椎前凸角度,t=4.178,P<0.001,腰椎高度Z=2.015,P=0.044);四线Cobb’s角、腰骶角之间差异无统计学意义(四线Cobb’s角,t=0.656,P=0.519;腰骶角,t=-1.881,P=0.073)。结论腰椎负重位MRI对腰椎前凸的评估具有重要的参考价值。

关键词：磁共振成像腰椎脊柱前凸负重仰卧位

Corrosion behavior of Al_(2)O_(3)-C bricks in MnO-containing mold slag

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Journal of Iron and Steel Research International 2024年第6期31卷 1486-1492页

作者： Yi-jiang Zhao guang-qiang Li Yang Wu cheng Yuan Ze Meng xiao-xuan Deng Yu Liu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina Research Institute of Technology Shougang Group Co.Ltd.Beijing 100043China

In order to explore the corrosion mechanism of Al_(2)O_(3)-C refractories in the mold flux bearing MnO,the immersion test of Al_(2)O_(3)-C refractories in CaO-SiO2-CaF2-MnO slag with different MnO contents was carried out at 1550℃.The results show that Mn particles were observed in the slag after experiment,due to the reduction of MnO by graphite in *** amounts of graphite were observed at the interface between refractories and slag,indicating that the oxidation of graphite is limited by the poor contact between graphite and molten ***,the oxidation of graphite is not the main cause of damage to refractories.A small quantity of CaO·2Al_(2)O_(3)(CA_(2))and CaO·6Al_(2)O_(3)(CA_(6))adjacent to Al_(2)O_(3) grain was detected at the slag/reaction layer ***_(2) and CA_(6) possess relatively high melting points,which is beneficial to hindering the further penetration of ***,the dissolution of Al_(2)O_(3) into slag is still the main cause for refractories *** increase in the MnO content of mold slag decreases the viscosity and then results in the severe corrosion of Al_(2)O_(3)-C bricks.

关键词： Al_(2)O_(3)-C refractory MnO-containing slag Graphite Corrosion

Comparison of Obesity Prevalence among Middle and High School Graduates before and after the COVID-19 Lockdown

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Biomedical and Environmental Sciences 2022年第12期35卷 1145-1149页

作者： LU Yan Hui DOU Zi Yan ZHAO Kai Ping YAN Dong CHEN Shuo cheng Jun Xia Glen M.BLAKE Karen HIND ZHANG Jing Bo cheng xiao guang WU Jing Department of Endocrinology the Second Medical CenterChinese PLA General HospitalNational Clinical Research Center for Geriatric DiseaseBeijing 100000China Beijing Physical Examination Center Beijing 100000China Department of Medical Record Management and Statistics Beijing Jishuitan HospitalBeijing 100000China Department of Radiology Beijing Jishuitan HospitalBeijing 100000China National Center for Chronic and Noncommunicable Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijing 100000China School of Biomedical Engineering&Imaging Sciences King’s College LondonSt Thomas’HospitalLondon SE17EHUnited Kingdom Department of Sport and Exercise Sciences Durham UniversityDurham 27704United Kingdom

The world has been engulfed in a COVID-19 pandemic that has significantly affected the health and economics of the *** Chinese authorities imposed lockdown measures to limit the spread of COVID-19 and stopped school programs for children and *** measures have been associated with increased sedentary time and reduced physical activity[1-3].An online questionnaire study of youth in China compared activity patterns before and after the COVID-19 lockdown.

关键词： before Middle stopped

Bioinspired design of integral molded Janus silk fibroin-MXene evaporator for efficient solar vapor generation

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Nano Research 2024年第4期17卷 2824-2835页

作者： Ling-Qing Kong Zhi-cheng Zeng guang-Zong Min Zhao-Hui Meng Guo-Qing Meng xiao-xiao Guo Nai-Bo Lin Xiang-Yang Liu The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province Research Center of Biomedical Engineering of XiamenDepartment of BiomaterialsCollege of MaterialsXiamen UniversityXiamen 361005China The State Key Laboratory of Marine Environmental Science(MEL) College of Ocean and Earth SciencesXiamen UniversityXiamen 361005China

Solar vapor generation is a promising sustainable technology that uses solar distillation to produce fresh water from seawater and wastewater,helping relieve global water resource ***,inspired by naturally grown integrally molded mulberry leaves with a Janus hydrophilic and hydrophobic structure,a novel,simple,and efficient integrated molding method is proposed to break through the limitations of the traditional split manufacturing strategy and realizes the integrated formation of Janus *** on the spontaneous sedimentation characteristics of MXene in silk fibroin solution and its regulation of mesoscopic structure and hydrophilicity of silk fibroin,layered structures with different compositions and hydrophilicities were obtained in one ***,ethanol and glutaraldehyde were added to construct a physical crystallization-chemical crosslinking dual stabilization structure in silk *** evaporator has the evaporation rate of 3.07 kg·m^(-2)·h^(-1) and the efficiency of 86.8%under 1 sun and maintains high evaporation performance under various extreme test conditions including vigorous washing,repeated compression,and high-intensity ultraviolet(UV)***,the evaporator performs well in practical application scenarios,its evaporation rate in the simulated Dead Sea seawater exceeds 2.13 kg·m^(-2)·h^(-1),and more than 99.9%of the salt,heavy metal ions,oil pollution,and dyes are purified.

关键词： silk fibroin MXene bioinspired integrated molding Janus structure solar vapor generation

Working condition recognition of sucker rod pumping system based on 4-segment time-frequency signature matrix and deep learning

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Petroleum Science 2024年第1期21卷 641-653页

作者： Yun-Peng He Hai-Bo cheng Peng Zeng Chuan-Zhi Zang Qing-Wei Dong guang-Xi Wan xiao-Ting Dong State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016LiaoningChina Key Laboratory of Networked Control Systems Chinese Academy of SciencesShenyang 110016LiaoningChina Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169LiaoningChina University of Chinese Academy of Sciences Beijing100049China School of Artifcial Intelligence Shenyang University of TechnologyShenyang 110870LiaoningChina

High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well *** learning-based method for classifying the dynamometer card(DC)of oil wells is an efficient diagnosis ***,the input of the DC as a two-dimensional image into the deep learning framework suffers from low feature utilization and high computational ***,different SRPSs in an oil field have various system parameters,and the same SRPS generates different DCs at different ***,there is heterogeneity in field data,which can dramatically impair the diagnostic *** solve the above problems,a working condition recognition method based on 4-segment time-frequency signature matrix(4S-TFSM)and deep learning is presented in this ***,the 4-segment time-frequency signature(4S-TFS)method that can reduce the computing power requirements is proposed for feature extraction of DC ***,the 4S-TFSM is constructed by relative normalization and matrix calculation to synthesize the features of multiple data and solve the problem of data ***,a convolutional neural network(CNN),one of the deep learning frameworks,is used to determine the functioning conditions based on the *** on field data verify that the proposed diagnostic method based on 4S-TFSM and CNN(4S-TFSM-CNN)can significantly improve the accuracy of working condition recognition with lower computational *** the best of our knowledge,this is the first work to discuss the effect of data heterogeneity on the working condition recognition performance of SRPS.

关键词： Sucker-rod pumping system Dynamometer card Working condition recognition Deep learning Time-frequency signature Time-frequency signature matrix