146 research outputs found

    Stiff deployable structures via coupling of thick Miura-ori tubes along creases

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    Origami-based structures play an important role in the realization of deployable mechanisms and unique mechanical properties via programmable deformation by folding. Among origami-based structures, tessellation by the coupling of origami tubes enriches the variations in geometry and mechanical properties. However, thickness accommodation is a critical problem in engineering applications involving the coupling of thick origami tubes. To solve this problem, this study proposes the coupling of thick Miura-ori tubes along the creases for facile fabrication, which sustains the one-degree-of-freedom (DOF) motion of thick Miura-ori tubes owing to the local mirror symmetry around the coupling interfaces. Furthermore, the coupling method contributes to the high stiffness of the coupled Miura-ori tubes, as evidenced by the wide gap in the eigenvalues between the one-DOF mode and the elastic modes obtained by the bar-and-hinge models. Finally, meter-scale coupled Miura-ori tubes were fabricated to demonstrate one-DOF motion and high stiffness. The findings of this study enable the rapid construction of structures by one-DOF motion and enhancement of transportability via flat-foldability.Comment: 41 pages, 16 figure

    The yeast Arf-GAP Glo3p is required for the endocytic recycling of cell surface proteins

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    Small GTP-binding proteins of the Ras superfamily play diverse roles in intracellular trafficking. Among them, the Rab, Arf, and Rho families function in successive steps of vesicle transport, in forming vesicles from donor membranes, directing vesicle trafficking toward target membranes and docking vesicles onto target membranes. These proteins act as molecular switches that are controlled by a cycle of GTP binding and hydrolysis regulated by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). In this study we explored the role of GAPs in the regulation of the endocytic pathway using fluorescently labeled yeast mating pheromone α-factor. Among 25 non-essential GAP mutants, we found that deletion of the GLO3 gene, encoding Arf-GAP protein, caused defective internalization of fluorescently labeled α-factor. Quantitative analysis revealed that glo3Δ cells show defective α-factor binding to the cell surface. Interestingly, Ste2p, the α-factor receptor, was mis-localized from the plasma membrane to the vacuole in glo3Δ cells. Domain deletion mutants of Glo3p revealed that a GAP-independent function, as well as the GAP activity, of Glo3p is important for both α-factor binding and Ste2p localization at the cell surface. Additionally, we found that deletion of the GLO3 gene affects the size and number of Arf1p-residing Golgi compartments and causes a defect in transport from the TGN to the plasma membrane. Furthermore, we demonstrated that glo3Δ cells were defective in the late endosome-to-TGN transport pathway, but not in the early endosome-to-TGN transport pathway. These findings suggest novel roles for Arf-GAP Glo3p in endocytic recycling of cell surface proteins

    Comparison of 19-gauge conventional and Franseen needles for the diagnosis of lymphadenopathy and classification of malignant lymphoma using endoscopic ultrasound fine-needle aspiration

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    Background/Aims Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) using a 19-gauge needle is an efficient sampling method for the diagnosis of lymphadenopathy. This study compared 19-gauge conventional and Franseen needles for the diagnosis of lymphadenopathy and classification of malignant lymphoma (ML). Methods Patient characteristics, number of needle passes, puncture route, sensitivity, specificity, and accuracy of cytology/histology for lymphadenopathy were analyzed in patients diagnosed with lymphadenopathy by EUS-FNA using conventional or Franseen needles. Results Between 2012 and 2022, 146 patients met the inclusion criteria (conventional [n=70] and Franseen [n=76]). The median number of needle passes was significantly lower in the conventional group than in the Franseen group (3 [1–6] vs. 4 [1–6], p=0.023). There were no significant differences in cytological/histological diagnoses between the two groups. For ML, the immunohistochemical evaluation rate, sensitivity of flow cytometry, and cytogenetic assessment were not significantly different in either group. Bleeding as adverse events (AEs) were observed in three patients in the Franseen group. Conclusions Both the 19-gauge conventional and Franseen needles showed high accuracy in lymphadenopathy and ML classification. Considering sufficient tissue collection and the avoidance of AEs, the use of 19-gauge conventional needles seems to be a good option for the diagnosis of lymphadenopathy

    Effects of monthly intravenous ibandronate on bone mineral density and microstructure in patients with primary osteoporosis after teriparatide treatment: The MONUMENT study

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    Purpose: To investigate the effects of sequential therapy with monthly intravenous ibandronate on bone mineral density (BMD) and microstructure in patients with primary osteoporosis who received teriparatide treatment. Methods: Sixty-six patients with primary osteoporosis who had undergone teriparatide treatment for more than 12 months (mean 18.6 months) received sequential therapy with 1 mg/month intravenous ibandronate for 12 months. The patients were evaluated using dual-energy X-ray absorptiometry (DXA), quantitative ultrasound, bone turnover markers, and high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline and 6 and 12 months after beginning administration. Results: At 12 months after beginning sequential therapy,the bone resorption marker, tartrate-resistant acid phosphatase-5b, decreased by 39.5%, with 82.3% of the patients exhibiting levels within the normal limit. DXA revealed that the BMD of the lumbar spine increased by 3.2%, with 79.0% of the patients exhibiting a response, and 40.3% experiencing an increase in BMD over 5%. HR-pQCT revealed that the cortical thickness of the distal tibia was increased by 2.6%. The cortical area increased by 2.5%, and the buckling ratio (an index of cortical instability) decreased by 2.5%. Most parameters of the trabecular bone showed no significant changes. These changes in the cortical bone were observed in both the distal radius and tibia and appeared beginning 6 months after treatment initiation. Conclusions: Sequential therapy with monthly intravenous ibandronate increased the BMD and improved the cortical bone microstructure of osteoporotic patients who had undergone teriparatide treatment

    Randomized controlled trial of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate in patients with postmenopausal osteoporosis: The TERABIT study

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    Purpose: The effects of daily teriparatide (20 μg) (D-PTH), weekly high-dose teriparatide (56.5 μg) (W-PTH), or bisphosphonates (BPs) on areal bone mineral density (aBMD), bone turnover markers (BTMs), volumetric BMD (vBMD), microarchitecture, and estimated strength were investigated in postmenopausal osteoporosis patients.Methods: The study participants were 131 women with a history of fragility fractures. They were randomized to receive D-PTH, W-PTH, or BPs (alendronate or risedronate) for 18 months. Dual-energy X-ray absorptiometry (DXA), BTMs, and high-resolution peripheral quantitative CT (HR-pQCT) parameters were evaluated at baseline and after 6 and 18 months of treatment. The primary endpoint was the change (%) in cortical thickness (Ct.Th) after 18 months\u27 treatment compared with baseline.Results: DXA showed that D-PTH, W-PTH, and BPs increased lumbar spine aBMD (+12.0%, +8.5%, and +6.8%) and total hip aBMD (+3.0%, +2.1%, and +3.0%), but D-PTH and W-PTH decreased 1/3 radius aBMD (− 4.1%, − 3.0%, − 1.4%) after 18 months. On HR-pQCT, D-PTH increased trabecular vBMD (Tb.vBMD) at the distal radius and tibia after 18 months (+6.4%, +3.7%) compared with the BPs group, decreased cortical volumetric tissue mineral density (Ct.vTMD) (− 1.8%, − 0.9%) compared with the other groups, increased Ct.Th (+1.3%, +3.9%), and increased failure load (FL) (+4.7%, +4.4%). W-PTH increased Tb.vBMD (+5.3%, +1.9%), maintained Ct.vTMD (− 0.7%, +0.2%) compared with D-PTH, increased Ct.Th (+0.6%, +3.6%), and increased FL (+4.9%, +4.5%). The BPs increased Tb.vBMD only in the radius (+2.0%, +0.2%), maintained Ct.vTMD (− 0.6%, +0.3%), increased Ct.Th (+0.5%, +3.4%), and increased FL (+3.9%, +2.8%).Conclusions: D-PTH and W-PTH comparably increased Ct.Th, the primary endpoint. D-PTH had a strong effect on trabecular bone. Although D-PTH decreased Ct.vTMD, it increased Ct.Th and total bone strength. W-PTH had a moderate effect on trabecular bone, maintained Ct.vTMD, and increased Ct.Th and total bone strength to the same extent as D-PTH

    Mobile DHHC palmitoylating enzyme mediates activity-sensitive synaptic targeting of PSD-95

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    Protein palmitoylation is the most common posttranslational lipid modification; its reversibility mediates protein shuttling between intracellular compartments. A large family of DHHC (Asp-His-His-Cys) proteins has emerged as protein palmitoyl acyltransferases (PATs). However, mechanisms that regulate these PATs in a physiological context remain unknown. In this study, we efficiently monitored the dynamic palmitate cycling on synaptic scaffold PSD-95. We found that blocking synaptic activity rapidly induces PSD-95 palmitoylation and mediates synaptic clustering of PSD-95 and associated AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid)-type glutamate receptors. A dendritically localized DHHC2 but not the Golgi-resident DHHC3 mediates this activity-sensitive palmitoylation. Upon activity blockade, DHHC2 translocates to the postsynaptic density to transduce this effect. These data demonstrate that individual DHHC members are differentially regulated and that dynamic recruitment of protein palmitoylation machinery enables compartmentalized regulation of protein trafficking in response to extracellular signals

    SORL1 Is Genetically Associated with Late-Onset Alzheimer’s Disease in Japanese, Koreans and Caucasians

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    To discover susceptibility genes of late-onset Alzheimer’s disease (LOAD), we conducted a 3-stage genome-wide association study (GWAS) using three populations: Japanese from the Japanese Genetic Consortium for Alzheimer Disease (JGSCAD), Koreans, and Caucasians from the Alzheimer Disease Genetic Consortium (ADGC). In Stage 1, we evaluated data for 5,877,918 genotyped and imputed SNPs in Japanese cases (n = 1,008) and controls (n = 1,016). Genome-wide significance was observed with 12 SNPs in the APOE region. Seven SNPs from other distinct regions with p-values ,261025 were genotyped in a second Japanese sample (885 cases, 985 controls), and evidence of association was confirmed for one SORL1 SNP (rs3781834, P=7.3361027 in the combined sample). Subsequent analysis combining results for several SORL1 SNPs in the Japanese, Korean (339 cases, 1,129 controls) and Caucasians (11,840 AD cases, 10,931 controls) revealed genome wide significance with rs11218343 (P=1.7761029) and rs3781834 (P=1.0461028). SNPs in previously established AD loci in Caucasians showed strong evidence of association in Japanese including rs3851179 near PICALM (P=1.7161025) and rs744373 near BIN1 (P = 1.3961024). The associated allele for each of these SNPs was the same as in Caucasians. These data demonstrate for the first time genome-wide significance of LOAD with SORL1 and confirm the role of other known loci for LOAD in Japanese. Our study highlights the importance of examining associations in multiple ethnic populations
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