|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | A new paleoenvironmental index for anoxic events—Mo isotopes in black shales from Upper Yangtze marine sediments显示文摘This paper investigates the high-solution of Mo isotopes and uses trace-element analyses for fresh and representative black shales and siliceous shales collected from the transition between the Late Ordovician and the Early Silurian at the Wangjiawan section in Yichang and the Late Permian Dalong Formation in the Shangsi Section of Sichuan. The applicability of different geochemical parameters used as paleo-oxygenation indices are also compared. The preliminary results show that V/(V+Ni), U auth (auth U), V/Cr, Ce anom and U/Th have a scattered variation range, but most samples plot within the suboxic-anoxic fields. The suboxic-anoxic environment was dominant during the deposition and formation of the two anoxic facies. These redox indicators show little correspondence to the δ 98 Mo values. The U/Mo ratio can be used as a potential proxy for the paleo-redox conditions due to the possibility that Mo is enriched relative to U at different redox gradients during early diagenesis. This evidence is more significant for the euxinicity condition and corresponds to positive δ 98 Mo (>1.5‰) values with low U/Mo ratios. This evidence is likely related to the depositional conditions near the boundary between anoxic and euxinic environments, which are characterised by low bioturbation or water circulation. Other samples reveal a wide scatter of U/Mo ratios and δ 98 Mo <1.5‰. These results are likely due to punctuated improvements in oxygenation with intense bioturbation or water circulation, which led to the redistribution of trace element. | ZHOU Lian SU Jie HUANG JunHua YAN JiaXing XIE XiNong GAO Shan DAI MengNing Tonger | 2011 | Science China Earth Sciences2011，54，7： | 9 |
| 2 | Prevalence and characteristics of macrosomia in the first and subsequent pregnancy: a multi-center retrospective study显示文摘To the Editor:Macrosomia is of growing prevalence and concern worldwide.In China,there has been a marked increase in the prevalence of macrosomia over the past few decades as a result of economic development and improvements in living standards. | Juan Juan Huixia Yang Yumei Wei Geng Song Rina Su Xu Chen Ruiqin Shan Jianying Yan Mei Xiao Ying Li Shihong Cui Xianlan Zhao Shangrong Fan Ling Feng Meihua Zhang Yuyan Ma Zishan You Haixia Mengn Haiwei Liu Jingxia Sun Yan Cai Kejia Hu | 2022 | Chinese Medical Journal2022，，12： | 1 |
| 3 | Fatigue properties of titanium alloy custom short stems fabricated by electron beam melting显示文摘The fatigue properties of titanium alloy short-stems with four different lengths,manufactured by electron beam melting(EBM)technology,were investigated by in vitro test and finite element(FE)analysis.FE simulation results indicate that the maximum tensile stress concentrates at the lateral side of the stem body.The magnitude of the concentrated tensile stress increases and the corresponding area of the axial section decreases with increasing of stem length.Results from fatigue tests demonstrate that fatigue cracks mainly initiate from the rough surface of the stem where the maximum tensile stress concentrates.The fatigue strength decreases with the increase of stem length,which is attributed to the higher stress concentration on the longer stem surface.In addition,it is found that post EBM treatment via hot isostatic processing(HIP)is able to enhance the fatigue properties of the stems,since the pores generated during EBM are mostly closed during HIP.Our work also demonstrates that the stress concentration on the stem surface can be effectively mitigated and the corresponding fatigue properties of the EBM-fabricated titanium alloy short stem can be considerably improved by optimizing the design in the stem length. | Liao Wang Shujun Li Mengning Yan Yubo Cheng Wentao Hou Yiping Wang Songtao Ai Rui Yang Kerong Dai | 2020 | Journal of Materials Science & Technology2020，52，17： | 0 |
| 4 | Epigenetic regulation of chondrocytes affected by mitochondria through mechanotransduction in osteoarthritis显示文摘Abnormal mechanical loading of articular cartilage is still considered an important pathogenic factor for osteoarthritis(OA).The occurrence and development of OA are accompanied by epigenetic alterations in chondrocytes.As the center of cellular energy metabolism,mitochondria have attracted increasing attention for their epigenetic regulation.Furthermore,mitochondria are mechanosensitive organelles,and abnormal mechanical loading affects chondrocyte epigenetics through the mitochondria,which may be one of the important mechanisms of OA pathogenesis.Well-known mitochondrial metabolites such as acetyl-CoA andα-ketoglutaric acid(α-KG)can be used as cofactors of histone modifying enzymes.Some histone modifying enzymes of lysine specific demethylase(KDMs)family are affected by mitochondrial function.In addition,TCA enzymes in mitochondria can undergo nuclear translocation and help regulate histone modification by catalyzing the generation of corresponding downstream products in the nucleus.However,the specific mechanism of mitochondrial epigenetic regulation of OA progression through chondrocytes remains unclear.Here,we discuss the changes in OA chondrocytes,their physiological activities under the conditions of physiological and supraphysiological mechanical loading,and the potential epigenetic regulation of mechanical loading through chondrocyte mitochondria.The combination of mechanobiological and epigenetic regulation mechanisms will provide new ideas and insights for the prevention and treatment of OA. | Tianyou Kan Zhifeng Yu Mengning Yan | 2023 | Medicine in Novel Technology and Devices2023，，2： | 0 |
| 5 | Association Between Knee Alignment,Disease Severity and Subchondral Trabecular Bone Microarchitecture in Patients with Knee Osteoarthritis显示文摘Objective Most patients with knee osteoarthritis(OA)have alignment deformity with the change of Hip-knee-ankle(HKA)angle.The knee alignment influences load distribution at the tibial plateau.Meanwhile,change of subchondral trabecular bone microstructure is related to load bearing and OA progression.However,the relationship between knee alignment on the changes of subchondral trabecular bone microstructure and OA severity have been poorly investigated.The main goal of this work was to investigate variation in tibial plateaus subchondral trabecular bone microstructure in knee OA patients and their association with the severity of OA with the change of knee alignment.Methods Seventy-one knee OA patients planning to undergo total knee arthroplasty were enrolled in this study.The HKA angle and OA disease severity(OARSI score,compartment-specific Kellgren-Lawrence(K-L)grade and OARSI Atlas grade)based on full-leg standing posteroanterior radiographs were evaluated preoperatively in all patients.The tibial plateau collected during surgery was first used for micro-computed tomography(μCT)to analyze the subchondral trabecular bone microstructures,and then used for pathological sections to analyze cartilage degeneration(OARSI score).Pearson and spearman correlations were used to examine linear relationships between knee alignment,OA disease severity and subchondral trabecular bone microstructure.Patients were then divided into group I(HKA angle exceeds 0°in the valgus direction),group II(varus angle<10°)and group III(varus angle≥10°).The differences in subchondral trabecular bone microstructural parameters between the three groups were analyzed by the one-way ANOVA with a post hoc Tukey test.Results HKA angle was significantly correlated with all tibial plateau subchondral trabecular bone microstructure parameters.Regardless of the medial or lateral tibia,HKA angle was most strongly correlated with bone volume fraction(BV/TV),M:(r=0. 613,P<0.01);L:(r=-0.490,P<0.01).In addition,for the media-to-lateral ratios(M:L)of the subchondral trabecular bone microstructure parameters,the HKA angle is positively correlated with M:L BV/TV(r=0.658,P<0.01),M:L trabecular number(Tb.N)(r=0.525,,P<0.01),M:L trabecular thickness(Tb.Th)(r=0.636,P<0.01),and negatively correlated with M:L trabecular separation(Tb.Sp)(r=-0.636,P<0.01)and M:L Specific Bone Surface(BS/BV)(r=-0.792,P<0.01).The BV/TV,Tb.N,and Tb.Th of the medial tibia were sequentially incremented in the order of groupⅠ,Ⅱ,Ⅲof knee alignment,while the Tb.Sp and BS/BV were decreased in this order.The lateral tibia is the opposite.In addition,most of the severity indices of OA are associated with subchondral trabecular bone microstructures,of which OARSI score and BV/TV in medial tibia are the most relevant(r=0.787,P<0.01).HKA angle is significantly correlated with all OA severity grades in medial compartment,but only with OARSI score and Bone sclerosis grade in lateral compartment.Conclusions Tibial plateau subchondral trabecular bone microarchitecture is associated with the HKA angle and OA severity.With the increase of varus angle and the severity of OA,the subchondral trabecular bone in medial tibia has more obvious sclerosis changes and vice versa,suggesting that knee malalignment may promote abnormal subchondral trabecular bone remodeling by altering joint load distribution,thereby affecting the progression of OA. | Xuequan Han Zihao He Linyang Chu Kai Xie Xu Jiang Mengning Yan Zhifeng Yu | 2019 | 医用生物力学2019，34，A01： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员