The relationship between P‐wave velocity (Vp) and unconfined compressive strength (C0) can be used to estimate in situ rock strength and stresses at depth in subduction zones. However, few reliable ...data on the Vp‐C0 relationship in deep accretionary prism sediments are available. Here, we determined the Vp‐C0 relationship down to ∼3.2 km in the Nankai accretionary prism from Vp measurements and indentation tests of drill cuttings retrieved from International Ocean Discovery Program Site C0002. In our results, the Nankai accretionary prism sediments tended to be weaker compared with estimates obtained by using other empirically determined Vp‐C0 relationships. We also examined the relationship between Vp and porosity in the accretionary prism. The Vp‐porosity relationship obtained by using only data of Nankai accretionary prism sediments showed that Vp generally increased with decreasing porosity; this result is consistent with published Vp‐porosity relationships for Nankai Trough sediments. The empirical relationships derived in this study should improve estimates of stress state, pore pressure, and fault strength in the Nankai accretionary prism.
Plain Language Summary
Stress conditions in a subduction zone must be known to understand how earthquakes in the zone are generated. To estimate stresses deep underground, the relationship between sonic (P‐) wave velocity and rock strength can be used. We thus measured P‐wave velocity and rock strength of small rocks and sediment chips, called drill cuttings, collected as deep as ∼3.2 km below the seafloor during a scientific ocean drilling project from a geological formation in the Nankai Trough called the Nankai accretionary prism. We then determined the relationship between P‐wave velocity and rock strength in the accretionary prism sediments. We found that the deep Nankai accretionary prism sediments were weaker than had been previously estimated. Our empirically derived relationship should contribute to improved estimation of stresses in the Nankai accretionary prism.
Key Points
The P‐wave velocity and strength of Nankai accretionary prism sediments were estimated from drill cuttings
The velocity‐porosity relationship showed that estimated in situ velocity gradually increased as estimated in situ porosity decreased
The relationship between velocity and strength suggests that Nankai accretionary prism sediments are weaker than previously thought
Mammalian target of rapamycin (mTOR) has a key role in the regulation of an array of cellular function. We found that rapamycin, an inhibitor of mTOR complex 1 (mTORC1), attenuated endoplasmic ...reticulum (ER) stress-induced apoptosis. Among three major branches of the unfolded protein response, rapamycin selectively suppressed the IRE1-JNK signaling without affecting PERK and ATF6 pathways. ER stress rapidly induced activation of mTORC1, which was responsible for induction of the IRE1-JNK pathway and apoptosis. Activation of mTORC1 reduced Akt phosphorylation, which was an event upstream of IRE-JNK signaling and consequent apoptosis. In vivo, administration with rapamycin significantly suppressed renal tubular injury and apoptosis in tunicamycin-treated mice. It was associated with enhanced phosphorylation of Akt and suppression of JNK activity in the kidney. These results disclosed that, under ER stress conditions, mTORC1 causes apoptosis through suppression of Akt and consequent induction of the IRE1-JNK pathway.
The metal-insulator transition (MIT), a fascinating phenomenon occurring in some strongly correlated materials, is of central interest in modern condensed-matter physics. Controlling the MIT by ...external stimuli is a key technological goal for applications in future electronic devices. However, the standard control by means of the field effect, which works extremely well for semiconductor transistors, faces severe difficulties when applied to the MIT. Hence, a radically different approach is needed. Here, we report an MIT induced by resonant tunneling (RT) in double quantum well (QW) structures of strongly correlated oxides. In our structures, two layers of the strongly correlated conductive oxide SrVO
(SVO) sandwich a barrier layer of the band insulator SrTiO
. The top QW is a marginal Mott-insulating SVO layer, while the bottom QW is a metallic SVO layer. Angle-resolved photoemission spectroscopy experiments reveal that the top QW layer becomes metallized when the thickness of the tunneling barrier layer is reduced. An analysis based on band structure calculations indicates that RT between the quantized states of the double QW induces the MIT. Our work opens avenues for realizing the Mott-transistor based on the wave-function engineering of strongly correlated electrons.
FGF-2 Stimulates Periodontal Regeneration Kitamura, M.; Akamatsu, M.; Machigashira, M. ...
Journal of dental research,
01/2011, Letnik:
90, Številka:
1
Journal Article
Recenzirano
The efficacy of the local application of recombinant human fibroblast growth factor-2 (FGF-2) in periodontal regeneration has been investigated. In this study, a randomized, double-blind, ...placebo-controlled clinical trial was conducted in 253 adult patients with periodontitis. Modified Widman periodontal surgery was performed, during which 200 µL of the investigational formulation containing 0% (vehicle alone), 0.2%, 0.3%, or 0.4% FGF-2 was administered to 2- or 3-walled vertical bone defects. Each dose of FGF-2 showed significant superiority over vehicle alone (p < 0.01) for the percentage of bone fill at 36 wks after administration, and the percentage peaked in the 0.3% FGF-2 group. No significant differences among groups were observed in clinical attachment regained, scoring approximately 2 mm. No clinical safety problems, including an abnormal increase in alveolar bone or ankylosis, were identified. These results strongly suggest that topical application of FGF-2 can be efficacious in the regeneration of human periodontal tissue that has been destroyed by periodontitis.
Abstract
Antiferromagnetic (AF) topological materials offer a fertile ground to explore a variety of quantum phenomena such as axion magnetoelectric dynamics and chiral Majorana fermions. To realize ...such intriguing states, it is essential to establish a direct link between electronic states and topology in the AF phase, whereas this has been challenging because of the lack of a suitable materials platform. Here we report the experimental realization of the AF topological-insulator phase in NdBi. By using micro-focused angle-resolved photoemission spectroscopy, we discovered contrasting surface electronic states for two types of AF domains; the surface having the out-of-plane component in the AF-ordering vector displays Dirac-cone states with a gigantic energy gap, whereas the surface parallel to the AF-ordering vector hosts gapless Dirac states despite the time-reversal-symmetry breaking. The present results establish an essential role of combined symmetry to protect massless Dirac fermions under the presence of AF order and widen opportunities to realize exotic phenomena utilizing AF topological materials.
Background and Objective
The association between periodontal disease and nutrient intake was examined using linked data from the 2005 National Health and Nutrition Survey, the Comprehensive Survey of ...Living Conditions and the Survey of Dental Diseases from the same year ‘using linked data from the National Health and Nutrition Survey, the Comprehensive Survey of Living Conditions and the Survey of Dental Diseases, all from 2005’. There has been increasing focus on the importance of nutritional factors in disease in recent years, but very few studies in Japan have looked at the association between periodontal disease and nutrients. Therefore, in the present study we investigated factors associated with periodontal disease, particularly in terms of nutrient intake.
Material and Methods
Data from 3043 individuals, ≥ 20 years of age (the original study sample comprised 4873 individuals, but those younger than 20 years of age and pregnant women were excluded from the present study) were compiled from linked responses to these three surveys from the same year. Permission to use the data was obtained from the Lifestyle‐Related Diseases Control General Affairs Division of the Ministry of Health, Labor, and Welfare, Japan. Information including basic attributes, family structure, economic status, physical condition, lifestyle habits, diet, dental habits, blood data, intake of foods (including the categories of food) and nutrient‐related information were obtained from the linked data. The individual maximum Community Periodontal Index (CPI) was used as an index of periodontal disease. Subjects were divided, according to maximum CPI, into groups in which CPI = 0–2 or CPI = 3–4, and associations between CPI and basic attributes, family structure, economic status, physical condition, lifestyle habits, diet, blood data and food intake were analyzed.
Results
Multivariate analysis revealed that the percentage of calories from fat was a nutrient factor associated with periodontal disease, with the percentage of calories from fat being significantly lower in the group with advanced periodontal disease.
Conclusion
The results suggest that a low‐fat, high‐carbohydrate diet is related to periodontal disease. A more detailed analysis of this topic will be conducted in the future using different indices of periodontal disease.
PLAP-1 is an extracellular matrix protein that is predominantly expressed in the periodontal ligament within periodontal tissue. It was previously revealed that PLAP-1 negatively regulates bone ...morphogenetic protein 2 and transforming growth factor β activity through direct interactions. However, the interaction between PLAP-1 and other growth factors has not been defined. Here, we revealed that PLAP-1 positively regulates the activity of fibroblast growth factor 2 (FGF-2), a critical growth factor in tissue homeostasis and repair. In this study, we isolated mouse embryonic fibroblasts (MEFs) from Plap-1-/- mice generated in our laboratory. Interestingly, Plap-1-/- MEFs exhibited enhanced responses to bone morphogenetic protein 2 but defective responses to FGF-2, and Plap-1 transfection into Plap-1-/- MEFs rescued these defective responses. In addition, binding assays revealed that PLAP-1 promotes FGF-2–FGF receptor 1 (FGFR1) complex formation by direct binding to FGF-2. Immunocytochemistry analyses revealed colocalization of PLAP-1 and FGF-2 in wild-type MEFs and reduced colocalization of FGF-2 and FGFR1 in Plap-1-/- MEFs compared with wild-type MEFs. Taken together, PLAP-1 positively regulates FGF-2 activity through a direct interaction. Extracellular matrix–growth factor interactions have considerable effects; thus, this approach may be useful in several regenerative medicine applications.
We previously demonstrated that topical application of fibroblast growth factor (FGF)-2 enhanced periodontal tissue regeneration. Although angiogenesis is a crucial event for tissue regeneration, the ...mechanism(s) by which topically applied FGF-2 induces angiogenesis in periodontal tissues has not been fully clarified. In this study, we investigated whether FGF-2 could induce vascular endothelial growth factor (VEGF)-A expression in periodontal ligament (PDL) cells and whether cell-to-cell interactions between PDL cells and endothelial cells could stimulate angiogenesis. FGF-2 induced VEGF-A secretion from MPDL22 cells (mouse periodontal ligament cell line) in a dose-dependent manner. Transwell and wound-healing assays revealed that co-stimulation with FGF-2 plus VEGF-A synergistically stimulated the migration of MPDL22 cells. Interestingly, co-culture of MPDL22 cells with bEnd5 cells (mouse endothelial cell line) also stimulated VEGF-A production from MPDL22 cells and tube formation by bEnd5 cells. Furthermore, time-lapse analysis revealed that MPDL22 cells migrated close to the tube-forming bEnd5 cells, mimicking pericytes. Thus, FGF-2 induces VEGF-A expression in PDL cells and induces angiogenesis in combination with VEGF-A. Cell-to-cell interactions with PDL cells also facilitate angiogenesis.
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