346 research outputs found

    Chaotic universe in the z=2 Hovava-Lifshitz gravity

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    The deformed z=2 Horava-Lifshitz gravity with coupling constant w leads to a nonrelativistic "mixmaster" cosmological model. The potential of theory is given by the sum of IR and UV potentials in the ADM Hamiltonian formalism. It turns out that adding the UV-potential cannot suppress chaotic behaviors existing in the IR-potential.Comment: 7 pages, 5 figures, version to appear in PR

    AAD-2004, a potent spin trapping molecule and microsomal prostaglandin E synthase-1 inhibitor, shows safety and efficacy in a mouse model of ALS

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    While free radicals and inflammation constitute major routes of neuronal injury occurring in neurodegenerative diseases, neither antioxidants nor nonsteroidal anti-inflammatory drugs (NSAIDs) have shown significant efficacy in human clinical trials. To explore the possibility that concurrent blockade of free radicals and PGE2-mediated inflammation might constitute a safe and effective therapeutic approach to certain neurodegenerative diseases, we have developed 2-hydroxy-5-[2-(4-trifluoromethylphenyl)-ethylaminobezoic acid (AAD-2004) as a derivative of aspirin. AAD-2004 completely removed free radicals at 50 nM as a potent spin trapping molecule and inhibited microsomal prostaglandin E synthase-1 (mPGES-1) with an IC50 of 230 nM. Oral administration of AAD-2004 blocked free radical formation, PGE2 formation, and microglial activation in the spinal motor neurons of SOD1G93A mice. As a consequence, AAD-2004 reduced autophagosome formation, axonopathy, and motor neuron degeneration, improving motor function and increasing life span. In these assays, AAD-2004 was superior to ibuprofen or riluzole. Gastric bleeding was not induced by AAD-2004 even at a dose 400-fold higher than that required to obtain maximal therapeutic efficacy in SOD1G93A mice. Targeting both mPGES-1 and free radicals may be a promising approach to reduce neurodegeneration in ALS and possibly other neurodegenerative diseases

    Causal Relationships Among Factors Affecting the Buildability in Executing Construction Projects in Vietnam

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    This paper aims to identify causal relationships among factors affecting the buildability in executing construction projects in Vietnam. First, through a comprehensive literature review, the study identified a full set of attributes that affect the buildability of construction projects. Subsequently, through discussions and interviews with experts, the study determined main attributes affecting the buildability in the context of the construction industry in Vietnam. After that, a survey questionnaire was developed which was based on identified attributes. The data after collected, was analysed by Structural Equation Model (SEM) and the expected result from the SEM model is a structural model. This structural model includes four factors, namely: Design applies advanced machinery, materials and construction methods; Design uses available resources at local for saving costs; Design applies safe construction methods; and Design uses prefabricated and typical components. The key finding of the study is to provide insights into causal relationships among factors affecting the buildability in executing construction projects in Vietnam

    Comparison of postoperative changes in the distal and proximal segments between conventional and sliding mini-plate fixation following mandibular setback

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    The purpose of the present study was to evaluate the postoperative three-dimensional (3D) changes in the proximal segments after mandibular setback sagittal split ramus osteotomy and to compare the changes between the conventional mini-plate fixation and semi-rigid sliding plate fixation

    Remineralization Property of an Orthodontic Primer Containing a Bioactive Glass with Silver and Zinc

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    White spot lesions (WSLs) are irreversible damages in orthodontic treatment due to excessive etching or demineralization by microorganisms. In this study, we conducted a mechanical and cell viability test to examine the antibacterial properties of 0.2% and 1% bioactive glass (BAG) and silver-doped and zinc-doped BAGs in a primer and evaluated their clinical applicability to prevent WSLs. The microhardness statistically significantly increased in the adhesive-containing BAG, while the other samples showed no statistically significant difference compared with the control group. The shear bond strength of all samples increased compared with that of the control group. The cell viability of the control and sample groups was similar within 24 h, but decreased slightly over 48 h. All samples showed antibacterial properties. Regarding remineralization property, the group containing 0.2% of the samples showed remineralization properties compared with the control group, but was not statistically significant; further, the group containing 1% of the samples showed a significant difference compared with the control group. Among them, the orthodontic bonding primer containing 1% silver-doped BAG showed the highest remineralization property. The new orthodontic bonding primer used in this study showed an antimicrobial effect, chemical remineralization effect, and WSL prevention as well as clinically applicable properties, both physically and biologically

    Multilevel Percutaneous Fenestrated Screw Fixation with Bone Cement Augmentation in Adult Lumbar Spinal Deformity

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    Objective Fenestrated screw fixation with bone cement augmentation has been demonstrated to increase the pullout strength. Bone cement augmentation is performed to prevent screw failure. The study aimed to investigate the safety and efficacy of multilevel percutaneous fenestrated screw fixation with bone cement augmentation in the adult lumbar spinal deformity. Methods We performed a retrospective study of 15 patients who underwent multilevel percutaneous fenestrated screw fixation (PFSF) with bone cement augmentation between January 2018 and December 2020. Visual analogue scale (VAS) score, Oswestry disability index (ODI), sagittal vertical axis (SVA), and lumbar lordosis (LL) were investigated in the patients. Results Mean BMD was -2.0. The mean percutaneous fenestrated screw fixation level was 6. The mean VAS score changed from 7.14 preoperatively to 4.57 postoperatively, to 3.71 at the last follow-up. The mean ODI changed from 45.21 preoperatively to 32.5 postoperatively, to 27.0 at the last follow-up. The mean LL changed from 23.6 preoperatively to 32.96 postoperatively, to 31.67 at the last follow-up. The mean SVA changed from 76.65 preoperatively to 46.15 postoperatively, to 48.46 at the last follow-up. The bony fusion rate was 73.3%. There were screw loosening in 4 patients and screw fracture in 3 patients. Cement leakage occurred towards the anterior body of the vertebrae in 2 patients but no symptoms were observed. Conclusion Our study results demonstrate that multilevel PFSF with bone cement augmentation can result in good clinical and radiological outcomes for lumbar spinal deformity. However, larger size screws or smaller through-hole screws are required to prevent screw fracture

    Admission levels of high-density lipoprotein and apolipoprotein A-1 are associated with the neurologic outcome in patients with out-of-hospital cardiac arrest

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    Objective To investigate whether serum levels of high-density lipoprotein (HDL) and apolipoprotein A-1 (ApoA1), after the return of spontaneous circulation, can predict the neurologic outcome in patients with out-of-hospital cardiac arrest (OHCA). Methods This was a retrospective observational study conducted in a single tertiary hospital intensive care unit. All adult OHCA survivors with admission lipid profiles were enrolled from March 2013 to December 2015. Good neurologic outcome was defined as discharge cerebral performance categories 1 and 2. Results Among 59 patients enrolled, 13 (22.0%) had a good neurologic outcome. Serum levels of HDL (56.7 vs. 40 mg/dL) and ApoA1 (117 vs. 91.6 mg/dL) were significantly higher in patients with a good outcome. Areas under the HDL and ApoA1 receiver operating curves to predict good outcomes were 0.799 and 0.759, respectively. The proportion of good outcome was significantly higher in patients in higher tertiles of HDL and ApoA1 (test for trend, both P=0.003). HDL (P=0.018) was an independent predictor in the multivariate logistic regression model. Conclusion Admission levels of HDL and ApoA1 are associated with neurologic outcome in patients with OHCA. Prognostic and potential therapeutic values of HDL and ApoA1 merit further evaluation in the post-cardiac arrest state, as in other systemic inflammatory conditions such as sepsis

    Tetrahydroabietic Acid, a Reduced Abietic Acid, Inhibits the Production of Inflammatory Mediators in RAW264.7 Macrophages Activated with Lipopolysaccharide

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    Abietic acid (AA), the main component of the rosin fraction of oleoresin synthesized by conifer species, has been reported to have anti-inflammatory effects. AA is a weak contact allergen; however, compounds resulting from its oxidation by air elicit stronger allergic response. Hydrogenation of the conjugated double bonds of AA, as in tetrahydroabietic acid (THAA), decreases its susceptibility to air oxidation and would thus reduce the allergenicity of AA. The aim of this study was to investigate whether THAA could exert anti-inflammatory effects to the same extent as AA in RAW264.7 macrophages activated with the endotoxin lipopolysaccharide (LPS). THAA and AA inhibited the production of nitric oxide (NO) and prostaglandin E2 by suppressing the expression of inducible NO synthase and cyclooxygenase-2, respectively, in LPS-activated RAW264.7 macrophages. They also inhibited the LPS-induced production of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α. Both THAA and AA prevented the LPS-induced nuclear translocation of the nuclear factor-κB/p65 subunit, suggesting that THAA may inhibit the production of pro-inflammatory mediators through the same mechanism as AA. In comparison, the anti-inflammatory effects of THAA and AA were almost identical, indicating that THAA retains the anti-inflammatory activity of AA at least in LPS-activated RAW264.7 macrophages
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