771 research outputs found

    Experimental investigation of plain- and flapped-wing tip vortices

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    Particle image velocimetry was used in a low-speed wind tunnel to investigate and characterize wing tip vortex structures. A rectangular wing of a subsonic wall interference model was used as a vortex generator in two different configurations: 1) plain wing and 2) flapped wing with the trailing-edge flap extended at 20 degrees. Vortex flow quantities and their dependence on angle of attack at Reynolds numbers of 32:8 � 103 and 43:8 � 103 were evaluated. Assessment of measured data reveals that the peak values of tangential velocities, vortex strength, and vorticities are directly proportional to the angle of attack. The vortex core radius value grows slowly as the angle of attack is increased. Both plain and flapped configurations showed similar trends. The peak tangential velocities and circulation almost doubled when the flapped configuration was used instead of the plain wing

    Experimental investigation of wing tip vortex

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    Particle image velocimetery was used in a low-speed wind tunnel to investigate and characterize wing tip vortex structures. A rectangular wing of a SWIM model was used as a vortex generator in two different configurations, (i) plain wing and (ii) flapped wing with trailing edge flap extended at 20 degrees. Vortex flow quantities and their dependence on angle of attack at a chord base Reynolds Number of 32.8x103 and 43.8x103 were evaluated. Assessment of measured data reveals that the peak values of tangential velocities, vortex strength and vorticities are directly proportional to the angle of attack. The vortex core radius value grows slowly as the angle of attack is increased. Both plain and flapped configurations showed similar trends. The peak tangential velocities and circulation distribution doubled when the flapped configuration was used instead of the plain wing

    Perturbation of the Hematopoietic System during Embryonic Liver Development Due to Disruption of Polyubiquitin Gene Ubc in Mice

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    Disruption of the polyubiquitin gene Ubc leads to a defect in fetal liver development, which can be partially rescued by increasing the amount of ubiquitin. However, it is still not known why Ubc is required for fetal liver development and the nature of the defective cell types responsible for embryonic lethality have not been characterized. In this study, we assessed the cause of embryonic lethality with respect to the fetal liver hematopoietic system. We found that Ubc was highly expressed in the embryonic liver, and the proliferation capacity of fetal liver cells was reduced in Ubc−/− embryos. Specifically, Ubc was most highly expressed in hematopoietic cells, and the proliferation capacity of hematopoietic cells was significantly impaired in Ubc−/− embryos. While hematopoietic cell and hematopoietic stem cell (HSC) frequency was maintained in Ubc−/− embryos, the absolute number of these cells was diminished because of reduced total liver cell number in Ubc−/− embryos. Transplantations of fetal liver cells into lethally irradiated recipient mice by non-competitive and competitive reconstitution methods indicated that disruption of Ubc does not significantly impair the intrinsic function of fetal liver HSCs. These findings suggest that disruption of Ubc reduces the absolute number of HSCs in embryonic livers, but has no significant effect on the autonomous function of HSCs. Thus, the lethality of Ubc−/− embryos is not the result of intrinsic HSC failure

    Effect of total intravenous versus inhalation anesthesia on long-term oncological outcomes in patients undergoing curative resection for early-stage non-small cell lung cancer: a retrospective cohort study

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    Background Propofol-based total intravenous anesthesia (TIVA) improves long-term outcomes after cancer surgery compared with inhalation anesthesia. However, its effect on patients undergoing non-small cell lung cancer (NSCLC) surgery remains unclear. We aimed to compare the oncological outcomes of TIVA and inhalation anesthesia after curative resection of early-stage NSCLC. Methods We analyzed the medical records of patients diagnosed with stage I or II NSCLC who underwent curative resection at a tertiary university hospital between January 2010 and December 2017. The primary outcomes were recurrence-free survival (RFS) and overall survival (OS) according to anesthesia type. Results We included 1,508 patients with stage I/II NSCLC. The patients were divided into the TIVA (n = 980) and Inhalation (n = 528) groups. The two groups were well-balanced in terms of baseline clinical characteristics. The TIVA group demonstrated significantly improved RFS (7.7 years, 95% CI [7.37, 8.02]) compared with the Inhalation group (6.8 years, 95% CI [6.30, 7.22], P = 0.003). Similarly, TIVA was superior to inhalation agents with respect to OS (median OS; 8.4 years, 95% CI [8.08, 8.69] vs. 7.3 years, 95% CI [6.81, 7.71]; P < 0.001). Multivariable Cox regression analysis revealed that TIVA was an independent prognostic factor related to recurrence (hazard ratio [HR]: 1.24, 95% CI [1.04, 1.47], P = 0.014) and OS (HR: 1.39, 95% CI [1.12, 1.72], P = 0.002). Conclusions Propofol-based TIVA was associated with better RFS and OS than inhalation anesthesia in patients with stage I/II NSCLC who underwent curative resection

    A multicenter phase II study of everolimus in patients with progressive unresectable adenoid cystic carcinoma

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    BACKGROUND: The aim of this study was to examine the efficacy and safety of everolimus in patients with progressive unresectable adenoid cystic carcinoma (ACC). METHODS: Histologically confirmed ACC patients with documented disease progression within 12 months prior to the study entry were eligible. Everolimus was given at a dose of 10 mg daily until progression or occurrence of unacceptable toxicities. The primary endpoint was a 4-month progression-free survival (PFS). RESULTS: A total of 34 patients were enrolled. The 4-month PFS probability was 65.5% (95% one-sided confidence interval [CI], 47.7 to infinity). Median PFS duration was 11.2 months (95% CI, 3.6 to 15.8). Complete or partial response was not achieved. Twenty-seven (79.4%, 95% CI, 63.2 to 89.6) patients showed stable disease (SD). Tumor shrinkage within SD criteria was observed in 15 patients (44.1%) and SD lasting 6 months was observed in 13 patients (38.2%). Four patients had disease progression. Among the 18 patients with both pre- and post-treatment (at 8 weeks) FDG-PET scans available, 8 patients (44.4%) showed a partial metabolic response, defined as a ≥25% reduction in maximum standardized uptake values (SUVmax). The most common adverse events were stomatitis, anemia, asthenia, and leukopenia. No unexpected everolimus related toxicities were reported. CONCLUSIONS: Everolimus showed promising efficacy and good tolerability in progressive unresectable ACC. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT0115284

    Loss of adipose TET proteins enhances ??-adrenergic responses and protects against obesity by epigenetic regulation of ??3-AR expression

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    ??-adrenergic receptor (??-AR) signaling plays predominant roles in modulating energy expenditure by triggering lipolysis and thermogenesis in adipose tissue, thereby conferring obesity resistance. Obesity is associated with diminished ??3-adrenergic receptor (??3-AR) expression and decreased ??-adrenergic responses, but the molecular mechanism coupling nutrient overload to catecholamine resistance remains poorly defined. Ten-eleven translocation (TET) proteins are dioxygenases that alter the methylation status of DNA by oxidizing 5-methylcytosine to 5-hydroxymethylcytosine and further oxidized derivatives. Here, we show that TET proteins are pivotal epigenetic suppressors of ??3-AR expression in adipocytes, thereby attenuating the responsiveness to ??-adrenergic stimulation. Deletion of all three Tet genes in adipocytes led to increased ??3-AR expression and thereby enhanced the downstream ??-adrenergic responses, including lipolysis, thermogenic gene induction, oxidative metabolism, and fat browning in vitro and in vivo. In mouse adipose tissues, Tet expression was elevated after mice ate a high-fat diet. Mice with adipose-specific ablation of all TET proteins maintained higher levels of ??3-AR in both white and brown adipose tissues and remained sensitive to ??-AR stimuli under high-fat diet challenge, leading to augmented energy expenditure and decreased fat accumulation. Consequently, they exhibited improved cold tolerance and were substantially protected from diet-induced obesity, inflammation, and metabolic complications, including insulin resistance and hyperlipidemia. Mechanistically, TET proteins directly repressed ??3-AR transcription, mainly in an enzymatic activity-independent manner, and involved the recruitment of histone deacetylases to increase deacetylation of its promoter. Thus, the TET-histone deacetylase-??3-AR axis could be targeted to treat obesity and related metabolic diseases

    A Case of Placenta Increta Presenting as Delayed Postabortal Intraperitoneal Bleeding in the First Trimester

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    Placenta increta is an uncommon and life-threatening complication of pregnancy characterized by complete or partial absence of the decidua basalis. Placenta increta usually presents with vaginal bleeding during difficult placental removal in the third-trimester. Although placenta increta may complicate first and early second-trimester pregnancy loss, the diagnosis can be very difficult during early pregnancy and thus the lesion is difficult to identify. We encountered with a woman who was diagnosed with placenta increta after receiving emergency hysterectomy due to intraperitoneal bleeding 2 months after an uncomplicated dilatation and curettage in the first trimester. Therefore, we report this case with a brief review of the literature

    Cu2Se-based thermoelectric cellular architectures for efficient and durable power generation

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    Thermoelectric power generation offers a promising way to recover waste heat. The geometrical design of thermoelectric legs in modules is important to ensure sustainable power generation but cannot be easily achieved by traditional fabrication processes. Herein, we propose the design of cellular thermoelectric architectures for efficient and durable power generation, realized by the extrusion-based 3D printing process of Cu2Se thermoelectric materials. We design the optimum aspect ratio of a cuboid thermoelectric leg to maximize the power output and extend this design to the mechanically stiff cellular architectures of hollow hexagonal column- and honeycomb-based thermoelectric legs. Moreover, we develop organic binder-free Cu2Se-based 3D-printing inks with desirable viscoelasticity, tailored with an additive of inorganic Se-8(2-) polyanion, fabricating the designed topologies. The computational simulation and experimental measurement demonstrate the superior power output and mechanical stiffness of the proposed cellular thermoelectric architectures to other designs, unveiling the importance of topological designs of thermoelectric legs toward higher power and longer durability
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