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Effects of Curved Periacetabular Osteotomy on the Stress Fields of the Pubic Rami and Ischium: A Finite Element Model Analysis

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Open Journal of Orthopedics 2013年第4期3卷 199-203页

作者： Norio Imai Yoichiro Dohmae Ken Suda dai miyasaka Tomoyuki Ito Naoto Endo Department of Orthopedic Surgery Nii- gata University Medical and Dental Hospital Niigata Japan. Department of Orthopedic Surgery Niigata Prefectural Shibata Hospital Niigata Japan Department of Orthopedic Surgery Niigata Prefectural Shibata Hospital Niigata Japan

Background: Postoperative pubic or ischial stress fracture may be a complication after curved periacetabular osteotomy (CPO). The discontinuity of the superior pubic rami is a risk factor for this complication. We investigated the stress field differences in standing and sitting positions after CPO. Methods: We used finite element analysis to assess the effects of inferior pubic rami and ischial fractures with or without discontinuity of superior pubic rami. We used the “union model”, obtained from a bony union at the osteotomy site of the superior pubic rami from 38-year-old woman who had undergone CPO for left hip dysplasia. We deleted the bony union region and created a discontinuity in the superior pubic rami equal to the non-union, creating the “discontinuity model”. We compared the stress field and stress value in the simulated standing and half weight-bearing positions on the operative side, one-legged standing position on the non-operative side, and the sitting position. Findings: In 4 cases, the inferior rami experienced the highest stress. Stress values in the discontinuity model were higher than those in the union model: 1.7 times in the case of one-legged standing on the operative side, 2.4 times in the case of half weight-bearing on the operative side, 3.8 times in the case of one-legged standing on the non-operative side, and 2.0 times in the sitting position, respectively. Interpretation: We recommend patients delay weight bearing on the operative side, avoid the sitting position as long as possible, and sit down slowly to prevent inferior pubic rami and ischial fractures after CPO.

关键词： Curved Periacetabular Osteotomy Ischial Fracture Inferior Pubic Ramifracture Stress Field Finite Element Analysis

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Do Femoral Neck and Stem Anteversion Affect Final Femur Rotation and Pelvic Positioning after Total Hip Arthroplasty?

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Open Journal of Orthopedics 2013年第3期3卷 183-188页

作者： Norio Imai Tomoyuki Ito Yasuhito Takahashi Yoji Horigome Ken Suda dai miyasaka Naoto Endo Department of Orthopedic Surgery Niigata University Medical and Dental Hospital Niigata Japan.

In this study, we have investigated the rotation of the pre-operative and post-operative femur, and stem anteversion to prevent impingement and dislocation. We studied 126 patients who had undergone primary total hip arthroplasty (THA) for the treatment of osteoarthritis. We compared preoperative tilt of anterior pelvic plane (APP), posterior condylar axis of the femur (PCA) relative to APP (APP-PCA) with those of postoperative ones in supine position. There was a moderate correlation between the preand post-operative APP-PCA values (r = 0.71). The postoperative APP-PCA decreased by approximately 6°. However, there was poor correlation between the stem anteversion and the postoperative APP-PCA (r = -0.27). A greater reduction in APP-PCA was observed among patients who exhibited greater external rotation of femur compared to those who showed less external rotation in supine position before THA. We also observed that the post-operative rotation of the femur was dependent on the pre-operative rotation of the femur while it was independent of the stem anteversion.

关键词： Anterior Pelvic Plane Posterior Condylar Axis Rotation Total Hip Arthroplasty

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<i>In vivo</i>relationship between the clinical epicondylar axis and the anterior pelvic plane in normal subjects

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Journal of Biomedical Science and Engineering 2013年第9期6卷 863-868页

作者： Norio Imai Tomoyuki Ito Yasuhito Takahashi Yoji Horigome Ken Suda dai miyasaka Izumi Minato Naoto Endo Department of Orthopedic Surgery Niigata Rinko Hospital Niigata Japan Department of Orthopedic Surgery Niigata University Dental and Medical Hospital Niigata Japan

Background: Several researchers consider the clinical epicondylar axis (CEA) as the functional flexion-extension axis of the knee. The anterior pelvic plane (APP) is commonly used as an anatomical reference plane of the pelvis. However, no study has investigated the relationship of the APP with the CEA and PCA. In this study, we aimed to investigate the relationship of the APP with the CEA and posterior condylar axis (PCA) in the standing and supine positions. Methods: We recruited 77 healthy Japanese subjects for this study, and carried out measurements using the Hip CAS?system, a 3D system used for the assessment of lower extremity alignment. Results: The mean femoral neck anteversion was 16.33°. There was an approximate discrepancy of 6° between the male and the female in anatomy (15.73° and 21.15° in the male and female subjects, respectively). The mean condylar twist angle (CTA) was 6.86° and the mean APP-PCA value in the standing position was ﹣6.88°. The mean APP-CEA value in the standing position was 0.02°, and the discrepancy between males and females was only 0.21° (0.09° and ﹣0.13° for the male and female subjects, respectively). This meant that Xp axis of APP and CEA were almost parallel. On the other hand, the mean APP-CEA value in the supine position was 7.07° (male subjects = 9.48°;female subjects = 5.62°). Here, the CEA was approximately parallel to the horizontal axis of the APP, which was compatible with the neutral position of the knee and hip joint, and anatomically and kinesiologically justified in normal subjects. Conclusion: CEA was approximately parallel to the horizontal axis of the APP. These results are compatible with regard to the neutral position of the knee and hip joints, and anatomically and kinesiologically justified in normal subjects. Moreover, CEA is a potential reference axis for the insertion of the femoral component in THA.

关键词： Anterior Pelvic Plane Posterior Condylar Axis Clinical Epicondylar Axis Hip CAS System

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Near-field wideband beam training for ELAA with uniform circular array

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Science China(Information Sciences) 2024年第6期67卷 370-383页

作者： Yuhao CHEN Linglong dai Department of Electronic Engineering Tsinghua UniversityBeijing National Research Center for Information Science and Technology (BNRist)

Extremely large-scale antenna array(ELAA) at millimeter wave(mmWave) and Terahertz(THz)band has been considered a key technology for combating high attenuation in high-frequency bands in future6G communications. Uniform circular arrays(UCAs) have attracted much attention because of their ability to provide flat beamforming gain at all angles. To realize efficient beamforming, beam training is widely used to acquire channel state information. However, with a large antenna number, the beam training overhead in ELAA systems becomes overwhelming. Moreover, with a large bandwidth, the beam defocus effect severely degrades beam training accuracy. To address these issues, this paper proposes a frequency-dependent focusing(FDF)-based beam training scheme to realize effective beam training in near-field wideband ELAA systems with UCA. Specifically, we first analyze the FDF property of UCA, where signals at different subcarriers can simultaneously focus on different distances. Then, by exploiting the FDF property to search different distances using different subcarriers simultaneously, we design a hierarchical codebook and propose an FDFbased beam training scheme. To reveal the effectiveness of the proposed scheme, we compare its necessary beam training overhead with that of existing schemes. Finally, the simulation results demonstrate that the proposed scheme can achieve accurate beam training in near-field wideband UCA systems with a low beam training overhead.

关键词： extremely large-scale antenna array (ELAA) uniform circular array (UCA) near-field wideband beam training

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Seismic performance evaluation of water supply pipes installed in a full-scale RC frame structure based on a shaking table test

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 163-178页

作者： Wu Houli Guo Endong Wang Jingyi dai Xin dai Chenxi Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China

As an important part of nonstructural components,the seismic response of indoor water supply pipes deserves much *** paper presents shaking table test research on water supply pipes installed in a full-scale reinforced concrete(RC)frame *** material pipes and different methods for penetrating the reinforced concrete floors are combined to evaluate the difference in seismic *** response spectra and pipe acceleration amplification factors based on test data are discussed and compared with code provisions.A seismic fragility study of displacement demand is conducted based on numerical *** acceleration response and displacement response of different combinations are *** results show that the combination of different pipe materials and different passing-through methods can cause obvious differences in the seismic response of indoor riser pipes.

关键词： water supply pipe different materials shaking table test amplification factor seismic fragility

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Biohythane production from two-stage anaerobic digestion of food waste:A review

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Journal of Environmental Sciences 2024年第5期139卷 334-349页

作者： Xiaona An Ying Xu Xiaohu dai State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

The biotransformation of food waste(FW)to bioenergy has attracted considerable research attention as a means to address the energy crisis and waste disposal *** this end,a promising technique is two-stage anaerobic digestion(TSAD),in which the FW is transformed to biohythane,a gaseous mixture of biomethane and *** review summarises the main characteristics of FW and describes the basic principle of ***,the factors influencing the TSAD performance are identified,and an overview of the research status;economic aspects;and strategies such as pre-treatment,co-digestion,and regulation of microbial consortia to increase the biohythane yield from TSAD is ***,the challenges and future considerations associated with the treatment of FW by TSAD are *** paper can provide valuable reference for the improvement and widespread implementation of TSAD-based FW treatment.

关键词： Two-stage anaerobic digestion(TSAD) Food waste(FW) Methane production Hydrogen production

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State of the art of lightweight aggregates used in lightweight refractories for working lining of high-temperature furnaces

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Journal of Iron and Steel Research International 2024年第6期31卷 1320-1343页

作者： Wei Zhang Wen-yong dai Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina Research and Development Department AGC Plibrico(Dalian)Industries Inc.Dalian 116600LiaoningChina

Lightweight refractories for the working lining of high-temperature furnaces play an important role in the smelting of advanced steels and *** prepare lightweight refractories for the working lining of high-temperature furnaces,the synthesis of lightweight aggregates is the ***,the research on the synthesis of lightweight aggregates with high service temperature,low thermal conductivity,high strength,and good slag resistance has received widespread *** available literature on the synthesis of lightweight aggregates was summarized,including corundum,mullite,mullite-corundum,spinel,corundum-spinel,cordierite,cordierite-mullite,calcium hexaluminate,corundum-calcium hexaluminate,bauxite,magnesia,magnesia-based,and forsterite-based ***,the future development trend of lightweight aggregates was proposed.

关键词： Lightweight aggregate Lightweight refractory Working lining Apparent porosity Closed porosity Thermal conductivity Pore-forming approach

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Impacts of external forcing and internal variability on the North Atlantic multidecadal variations since 1950

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Science China Earth Sciences 2024年第8期67卷 2699-2701页

作者： Wenjian HUA Aiguo dai Key Laboratory of Meteorological Disaster Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjing 210044China Department of Atmospheric and Environmental Sciences University at AlbanyState University of New YorkAlbany 12222USA

The physical formation mechanisms of the Atlantic Multidecadal Variability(AMV)in the context of global warming have been a key research topic(Vecchi et al.,2017).The conventional view is that the AMV is mainly driven by internal dynamics within the climate system,especially in the Atlantic Ocean(Zhang et al.,2019).However,some studies suggest that decadal to multidecadal variations in North Atlantic sea surface temperature(SST)since around 1950 are related to anthropogenic and natural aerosol emissions(Otter?et al.,2010;Booth et al.,2012;Hua et al.,2019).

关键词： Atlantic decadal forcing

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On-demand molecular design for efficient blue phosphorescence

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Science China Chemistry 2024年第7期67卷 2124-2126页

作者： Meiqi dai Dongpeng Yan Beijing Key Laboratory of Energy Conversion and Storage Materials Key Laboratory of RadiopharmaceuticalsMinistry of EducationCollege of ChemistryBeijing Normal UniversityBeijing 100875China

Blue luminescence(including both fluorescence and phosphorescence)is one of the core elements in solid-state lighting and full-color *** to now,ultralong room temperature phosphorescence(RTP)with a long lifetime over 0.1 s has been continuously *** ultralong phosphorescence emission bands are in the region of 500 to600 ***,high-energy blue phosphorescence remains an immense challenge[1].

关键词： blue lifetime bands

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Neighborhood predictors of short sleep duration and bedtime irregularity among children in the United States: results from the 2019-2020 National Surveyof Children's Health

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World Journal of Pediatrics 2024年第1期20卷 73-81页

作者： Ying dai Jianghong Liu School of Nursing University of Pennsylvania418 Curie Blvd.Room 426Claire M.Fagin HallPhiladelphiaPA19104-6096USA

Background Environmental factors may contribute to short sleep duration and irregular bedtime in *** factors and children's sleep duration and bedtime regularity remain a less investigated *** aim of this study was to investigate the national and state-level proportions of children with short sleep duration and irregular bedtime and their neighborhood *** A total of 67,598 children whose parents completed the National Survey of Children's Health in 2019-2020 were included in the ***-weighted Poisson regression was used to explore the neighborhood predictors of children's short sleep duration and irregular *** The prevalence of short sleep duration and irregular bedtime among children in the United States(US)was 34.6%[95%confidence interval(CI)=33.8%-35.4%]and 16.4%(95%CI=15.6%-17.2%)in 2019-2020,*** neighborhoods,supportive neighborhoods,and neighborhoods with amenities were found to be protective factors against children's short sleep duration,with risk ratios ranging between 0.92 and 0.94,P<*** with detracting elements were associated with an increased risk of short sleep duration[risk ratio(RR)=1.06,95%CI=1.00-1.12]and irregular bedtime(RR=1.15,95%CI=1.03-1.28).Child race/ethnicity moderated the relationship between neighborhood with amenities and short *** Insufficient sleep duration and irregular bedtime were highly prevalent among US children.A favorable neighborhood environment can decrease children's risk of short sleep duration and irregular *** the neighborhood environment has implications for children's sleep health,especially for children from minority racial/ethnic groups.

关键词： Child National Survey of Children's Health Neighborhood.Sleep Social determinants of health

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