http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Metal-Insulator Transition Induced by Short Range Magnetic Ordering in Mono-layered Manganite
Chi, E.O.,Kim, W.S.,Hong, C.S.,Hur, N.H.,Choi, Y.N. Korean Chemical Society 2003 Bulletin of the Korean Chemical Society Vol.24 No.5
The structural, magnetic, and transport properties of a mono-layered manganite $La_{0.7}Sr_{1.3}MnO_{4+{\delta}}$ were investigated using variable temperature neutron powder diffraction as well as magnetization and transport measurements. The compound adopts the tetragonal I4/mmm symmetry and exhibits no magnetic reflection in the temperature region of 10 K ≤ T ≤ 300 K. A weak ferromagnetic (FM) transition occurs about 130 K, which almost coincides with the onset of a metal-insulator (M-I) transition. Extra oxygen that occupies the interstitial site between the [(La,Sr)O] layers makes the spacing between the [MnO₂] layers shorten, which enhances the inter-layer coupling and eventually leads to the M-I transition. We also found negative magneto resistance (MR) below the M-I transition temperature, which can be understood on the basis of the percolative transport via FM metallic domains in the antiferromagnetic (AFM) insulating matrix.
Lin Maohua,Paul Rudy,Shapiro Stephen Z.,Doulgeris James,O’Connor Timothy E.,Tsai Chi-Tay,Vrionis Frank D. 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.5
Study Design: This study compares four cervical endplate removal procedures, validated by finite element models.Purpose: To characterize the effect of biomechanical strength and increased contact area on the maximum von Mises stress, migration, and subsidence between the cancellous bone, endplate, and implanted cage.Overview of Literature: Anterior cervical discectomy and fusion (ACDF) has been widely used for treating patients with degenerative spondylosis. However, no direct correlations have been drawn that incorporate the impact of the contact area between the cage and the vertebra/endplate.Methods: Model 1 (M1) was an intact C2C6 model with a 0.5 mm endplate. In model 2 (M2), a cage was implanted after removal of the C4–C5 and C5–C6 discs with preservation of the osseous endplate. In model 3 (M3), 1 mm of the osseous endplate was removed at the upper endplate. Model 4 (M4) resembles M3, except that 3 mm of the osseous endplate was removed.Results: The range of motion (ROM) at C2C6 in the M2–M4 models was reduced by at least 9º compared to the M1 model. The von Mises stress results in the C2C3 and C3C4 interbody discs were significantly smaller in the M1 model and slightly increased in the M2–M3 and M3–M4 models. Migration and subsidence decreased from the M2–M3 model, whereas further endplate removal increased the migration and subsidence as shown in the transition from M3 to M4.Conclusions: The M3 model had the least subsidence and migration. The ROM was higher in the M3 model than the M2 and M4 models. Endplate preparation created small stress differences in the healthy intervertebral discs above the ACDF site. A 1 mm embedding depth created the best balance of mechanical strength and contact area, resulting in the most favorable stability of the construct.
A Review of Finite Element Modeling for Anterior Cervical Discectomy and Fusion
Lin Maohua,Paul Rudy,Dhar Utpal Kanti,Doulgeris James,O’Connor Timothy E.,Tsai Chi-Tay,Vrionis Frank D. 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.5
The cervical spine poses many complex challenges that require complex solutions. Anterior cervical discectomy and fusion (ACDF) has been one such technique often employed to address such issues. In order to address the problems with ACDF and assess the modifications that have been made to the technique over time, finite element analyses (FEA) have proven to be an effective tool. The variations of cervical spine FEA models that have been produced over the past couple of decades, particularly more recent representations of more complex geometries, have not yet been identified and characterized in any literature. Our objective was to present material property models and cervical spine models for various simulation purposes. The outlining and refinement of the FEA process will yield more reliable outcomes and provide a stable basis for the modeling protocols of the cervical spine.
Survival of tissue-resident memory T cells requires exogenous lipid uptake and metabolism
Pan, Youdong,Tian, Tian,Park, Chang Ook,Lofftus, Serena Y.,Mei, Shenglin,Liu, Xing,Luo, Chi,O’Malley, John T.,Gehad, Ahmed,Teague, Jessica E.,Divito, Sherrie J.,Fuhlbrigge, Robert,Puigserver, Pere,Kru Macmillan Publishers Limited, part of Springer Nat 2017 Nature Vol.543 No.7644
Tissue-resident memory T (T<SUB>RM</SUB>) cells persist indefinitely in epithelial barrier tissues and protect the host against pathogens. However, the biological pathways that enable the long-term survival of T<SUB>RM</SUB> cells are obscure. Here we show that mouse CD8<SUP>+</SUP> T<SUB>RM</SUB> cells generated by viral infection of the skin differentially express high levels of several molecules that mediate lipid uptake and intracellular transport, including fatty-acid-binding proteins 4 and 5 (FABP4 and FABP5). We further show that T-cell-specific deficiency of Fabp4 and Fabp5 (Fabp4/Fabp5) impairs exogenous free fatty acid (FFA) uptake by CD8<SUP>+</SUP> T<SUB>RM</SUB> cells and greatly reduces their long-term survival in vivo, while having no effect on the survival of central memory T (T<SUB>CM</SUB>) cells in lymph nodes. In vitro, CD8<SUP>+</SUP> T<SUB>RM</SUB> cells, but not CD8<SUP>+</SUP> T<SUB>CM</SUB> cells, demonstrated increased mitochondrial oxidative metabolism in the presence of exogenous FFAs; this increase was not seen in Fabp4/Fabp5 double-knockout CD8<SUP>+</SUP> T<SUB>RM</SUB> cells. The persistence of CD8<SUP>+</SUP> T<SUB>RM</SUB> cells in the skin was strongly diminished by inhibition of mitochondrial FFA β-oxidation in vivo. Moreover, skin CD8<SUP>+</SUP> T<SUB>RM</SUB> cells that lacked Fabp4/Fabp5 were less effective at protecting mice from cutaneous viral infection, and lung Fabp4/Fabp5 double-knockout CD8<SUP>+</SUP> T<SUB>RM</SUB> cells generated by skin vaccinia virus (VACV) infection were less effective at protecting mice from a lethal pulmonary challenge with VACV. Consistent with the mouse data, increased FABP4 and FABP5 expression and enhanced extracellular FFA uptake were also demonstrated in human CD8<SUP>+</SUP> T<SUB>RM</SUB> cells in normal and psoriatic skin. These results suggest that FABP4 and FABP5 have a critical role in the maintenance, longevity and function of CD8<SUP>+</SUP> T<SUB>RM</SUB> cells, and suggest that CD8<SUP>+</SUP> T<SUB>RM</SUB> cells use exogenous FFAs and their oxidative metabolism to persist in tissue and to mediate protective immunity.