415 research outputs found

    Causal Mediation Analysis with Multiple Time-Varying Mediators

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    In longitudinal studies with time-varying exposures and mediators, the mediational g-formula is an important method for the assessment of direct and indirect effects. However, current methodologies based on the mediational g-formula can deal with only one mediator. This limitation makes these methodologies inapplicable to many scenarios. Hence, we develop a novel methodology by extending the mediational g-formula to cover cases with multiple time-varying mediators. We formulate two variants of our approach that are each suited to a distinct set of assumptions and effect definitions and present nonparametric identification results of each variant. We further show how complex causal mechanisms (whose complexity derives from the presence of multiple time-varying mediators) can be untangled. A parametric method along with a user-friendly algorithm was implemented in R software. We illustrate our method by investigating the complex causal mechanism underlying the progression of chronic obstructive pulmonary disease. We found that the effects of lung function impairment mediated by dyspnea symptoms and mediated by physical activity accounted for 13.7% and 10.8% of the total effect, respectively. Our analyses thus illustrate the power of this approach, providing evidence for the mediating role of dyspnea and physical activity on the causal pathway from lung function impairment to health status

    Reconstruction for Mandibular Implant Failure

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    Mandibular defects may result from tumor ablations, trauma, or radiation necrosis. Significant segmental mandibular loss or hemimandibular loss may sometimes be replaced with mandibular implants by ENT surgeons/oral surgeons/head and neck surgeons. However, this may bring about mandibular implant failure in long-term follow-up. Mandibular implant failures usually manifest as: soft tissue atrophy, mandibular implant extrusion, infection, facial nerve involvement, facial asymmetry, derangement of occlusion and mastication, orocutaneous fistula, etc. Over 30 years, the authors have treated 102 patients with mandibular implant failure. Reconstruction may involve removal of the mandibular implant and immediate replacement of the mandibular defect with a piece of vascularized bone flap, not only to compensate for bone loss but also to replace neighboring soft tissue and possible skin defects. Frequently used flaps have been vascularized iliac bone (89/102) or vascularized fibula grafts (13/102). During follow-up, iliac bone flap reconstruction has yielded more favorable results due to its ample bone bulk and adequate soft tissue coverage. Fibula flaps with osteotomies have been associated with an increasing incidence of malunion/nonunion and subsequent easy deformation

    Recombinant VP1, an Akt Inhibitor, Suppresses Progression of Hepatocellular Carcinoma by Inducing Apoptosis and Modulation of CCL2 Production

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    BACKGROUND: The application of viral elements in tumor therapy is one facet of cancer research. Recombinant capsid protein VP1 (rVP1) of foot-and-mouth disease virus has previously been demonstrated to induce apoptosis in cancer cell lines. Here, we aim to further investigate its apoptotic mechanism and possible anti-metastatic effect in murine models of hepatocellular carcinoma (HCC), one of the most common human cancers worldwide. METHODOLOGY/PRINCIPAL FINDINGS: Treatment with rVP1 inhibited cell proliferation in two murine HCC cell lines, BNL and Hepa1-6, with IC₅₀ values in the range of 0.1-0.2 µM. rVP1 also induced apoptosis in these cells, which was mediated by Akt deactivation and dissociation of Ku70-Bax, and resulted in conformational changes and mitochondrial translocation of Bax, leading to the activation of caspases-9, -3 and -7. Treatment with 0.025 µM rVP1, which did not affect the viability of normal hepatocytes, suppressed cell migration and invasion via attenuating CCL2 production. The production of CCL2 was modulated by Akt-dependent NF-κB activation that was decreased after rVP1 treatment. The in vivo antitumor effects of rVP1 were assessed in both subcutaneous and orthotopic mouse models of HCC in immune-competent BALB/c mice. Intratumoral delivery of rVP1 inhibited subcutaneous tumor growth as a result of increased apoptosis. Intravenous administration of rVP1 in an orthotopic HCC model suppressed tumor growth, inhibited intra-hepatic metastasis, and prolonged survival. Furthermore, a decrease in the serum level of CCL2 was observed in rVP1-treated mice. CONCLUSIONS/SIGNIFICANCE: The data presented herein suggest that, via inhibiting Akt phosphorylation, rVP1 suppresses the growth, migration, and invasion of murine HCC cells by inducing apoptosis and attenuating CCL2 production both in vitro and in vivo. Recombinant protein VP1 thus has the potential to be developed as a new therapeutic agent for HCC

    Sustainable Solution for Shoring Method of Cross-Creek Bridge in Ankeng MRT System in New Taipei City: A Case Study

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    In the Ankeng Light Rail MRT system (ALRMS) project, the U7 box girder passes crossing the Erbads creek and needs a temporary supporting system for the construction work.  In this study, three temporary shoring system options were proposed to be the construction method.  The D-B Contractor, New Asia construction and Development Corporation, evaluated and selected the optimal choice, The Steel truss frame with supporting beams, to serve as the temporary supporting system.  Compare the deflection of Δmax and Δactual, which are 1.609 cm and 1.59 cm, respectively.  This result presented that the shoring system composed of the H912*302*18*37 supporting beams and steel truss frame had achieved outstanding performance and work to construct the U7 box girder.  This paper presents how the three options are evaluated and the detailed construction processes along with the survey verification for the method

    Bevacizumab Dose Affects the Severity of Adverse Events in Gynecologic Malignancies

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    In this retrospective study, we investigated adverse events and outcomes in patients treated with bevacizumab for ovarian, fallopian tube, or primary peritoneal cancers at a single hospital. We determined the cumulative incidences of various bevacizumab-related adverse events and the correlation between dose and adverse event incidences. We analyzed data from 154 patients that received 251 rounds of bevacizumab as first-line, first salvage, >2 salvage treatments. Adverse events of any grade were observed in 121 (78.6%) patients; at least one grade 3 or 4 adverse event occurred in 32 (20.8%) patients. The two most common events were proteinuria (38.3%) and hypertension (33.8%). The first-line treatment group displayed significantly higher frequencies of hypertension (52.7% vs. 18.9% vs. 15.5%, p < 0.001), wound complications (9.1% vs. 0% vs. 1.2%, p = 0.010), arthralgia (29.1% vs. 11.3% vs. 8.3%, p = 0.003), and reduced range of joint motion (14.5% vs. 5.7% vs. 3.6%, p = 0.046), compared to those in the first and >2 lines salvage groups, respectively (Kruskal–Wallis test). The cumulative incidences of all grades and grades 3/4 of hypertension cumulative incidence plateaued at around 30% for all grades and 10% for grades 3 and 4, at bevacizumab doses above 8080 and 3510 mg, respectively. The proteinuria cumulative incidence plateaued at around 35% for all grades and 3% for grades 3 and 4, at bevacizumab doses above 11,190 and 4530 mg, respectively. We concluded that, in this realistic clinical population, different kinds and higher cumulative incidences of adverse events were observed compared to those reported in previous clinical trials. Moreover, bevacizumab doses showed cumulative toxicity and plateau effects on hypertension and proteinuria

    Caspase-11–mediated endothelial pyroptosis underlies endotoxemia-induced lung injury

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    Acute lung injury is a leading cause of death in bacterial sepsis due to the wholesale destruction of the lung endothelial barrier, which results in protein-rich lung edema, influx of proinflammatory leukocytes, and intractable hypoxemia. Pyroptosis is a form of programmed lytic cell death that is triggered by inflammatory caspases, but little is known about its role in EC death and acute lung injury. Here, we show that systemic exposure to the bacterial endotoxin lipopolysaccharide (LPS) causes severe endothelial pyroptosis that is mediated by the inflammatory caspases, human caspases 4/5 in human ECs, or the murine homolog caspase-11 in mice in vivo. In caspase-11–deficient mice, BM transplantation with WT hematopoietic cells did not abrogate endotoxemia-induced acute lung injury, indicating a central role for nonhematopoietic caspase-11 in endotoxemia. Additionally, conditional deletion of caspase-11 in ECs reduced endotoxemia-induced lung edema, neutrophil accumulation, and death. These results establish the requisite role of endothelial pyroptosis in endotoxemic tissue injury and suggest that endothelial inflammatory caspases are an important therapeutic target for acute lung injury

    Platform Deformation Phase Correction for the AMiBA-13 Coplanar Interferometer

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    [[abstract]]We present a new way to solve the platform deformation problem of coplanar interferometers. The platform of a coplanar interferometer can be deformed due to driving forces and gravity. A deformed platform will induce extra components into the geometric delay of each baseline and change the phases of observed visibilities. The reconstructed images will also be diluted due to the errors of the phases. The platform deformations of The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) were modeled based on photogrammetry data with about 20 mount pointing positions. We then used the differential optical pointing error between two optical telescopes to fit the model parameters in the entire horizontal coordinate space. With the platform deformation model, we can predict the errors of the geometric phase delays due to platform deformation with a given azimuth and elevation of the targets and calibrators. After correcting the phases of the radio point sources in the AMiBA interferometric data, we recover 50%-70% flux loss due to phase errors. This allows us to restore more than 90% of a source flux. The method outlined in this work is not only applicable to the correction of deformation for other coplanar telescopes but also to single-dish telescopes with deformation problems. This work also forms the basis of the upcoming science results of AMiBA-13.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]電子版[[booktype]]紙本[[countrycodes]]US

    Voluntary Wheel Running Reverses Deficits in Social Behavior Induced by Chronic Social Defeat Stress in Mice: Involvement of the Dopamine System

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    Voluntary exercise has been reported to have a therapeutic effect on many psychiatric disorders and social stress is known to impair social interaction. However, whether voluntary exercise could reverse deficits in social behaviors induced by chronic social defeat stress (CSDS) and the underlying mechanism remain unclear. The present study shows CSDS impaired social preference and induced social interaction deficiency in susceptible mice. Voluntary wheel running (VWR) reversed these effects. In addition, CSDS decreased the levels of tyrosine hydroxylase in the ventral tegmental area and the D2 receptor (D2R) in the nucleus accumbens (NAc) shell. These changes can be recovered by VWR. Furthermore, the recovery effect of VWR on deficits in social behaviors in CSDS mice was blocked by the microinjection of D2R antagonist raclopride into the NAc shell. Thus, these results suggest that the mechanism underlying CSDS-induced social interaction disorder might be caused by an alteration of the dopamine system. VWR may be a novel means to treat CSDS-induced deficits in social behaviors via modifying the dopamine system

    Integration, Launch, and First Results from IDEASSat/INSPIRESat-2 - A 3U CubeSat for Ionospheric Physics and Multi-National Capacity Building

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    The Ionospheric Dynamics and Attitude Subsystem Satellite (IDEASSat) is a 3U CubeSat carrying a Compact Ionospheric Probe (CIP) to detect ionospheric irregularities that can impact the usability and accuracy of global satellite navigation systems (GNSS), as well as satellite and terrestrial over the horizon communications. The spacecraft was developed by National Central University (NCU) in Taiwan, with additional development and operational support from partners in the International Satellite Program in Science and Education (INSPIRE) consortium. The spacecraft system needed to accommodate these mission objectives required three axis attitude control, dual band communications capable of supporting both tracking, telemetry and command (TT&C) and science data downlink, as well as flight software and ground systems capable of supporting the autonomous operation and short contact times inherent to a low Earth orbit mission developed on a limited university budget with funding agency-imposed constraints. As the first spacecraft developed at NCU, lessons learned during the development, integration, and operation of IDEASSat have proven to be crucial to the objective of developing a sustainable small satellite program. IDEASSat was launched successfully on January 24, 2021 aboard the SpaceX Falcon 9 Transporter 1 flight. and successfully began operations, demonstrating power, thermal, and structural margins, as well as validation of uplink and downlink communications functionality, and autonomous operation. A serious anomaly occurred after 22 days on orbit when communication with the spacecraft were abruptly lost. Communication was re-established after 1.5 months for sufficient time to downlink stored flight data, which allowed the cause of the blackout to be identified to a high level of confidence and precision. In this paper, we will report on experiences and anomalies encountered during the final flight model integration and delivery, commissioning, and operations. The agile support from the international amateur radio community and INSPIRE partners were extremely helpful in this process, especially during the initial commissioning phase following launch. It is hoped that the lessons learned reported here will be helpful for other university teams working to develop spaceflight capacity
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