1,201 research outputs found

    Development of a Piezoelectric Vacuum Sensing Component for a Wide Pressure Range

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    In this study, we develop a clamped-clamped beam-type piezoelectric vacuum pressure sensing element. The clamped-clamped piezoelectric beam is composed of a PZT layer and a copper substrate. A pair of electrodes is set near each end. An input voltage is applied to a pair of electrodes to vibrate the piezoelectric beam, and the output voltage is measured at the other pair. Because the viscous forces on the piezoelectric beam vary at different air pressures, the vibration of the beam depends on the vacuum pressure. The developed pressure sensor can sense a wide range of pressure, from 6.5 × 10(-6) to 760 Torr. The experimental results showed that the output voltage is inversely proportional to the gas damping ratio, and thus, the vacuum pressure was estimated from the output voltage

    Glycine tomentella Hayata inhibits IL-1β and IL-6 production, inhibits MMP-9 activity, and enhances RAW264.7 macrophage clearance of apoptotic cells

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    <p>Abstract</p> <p>Background</p> <p>To assess the effects of <it>Glycine tomentella </it>Hayata (GTH), a traditional herbal medicine for treatment of rheumatic diseases on the expression of the proinflammatory cytokines and on the clearance of apoptotic cells by macrophages.</p> <p>Methods</p> <p>RAW264.7 cells were cultured with lipopolysaccharide (LPS) in the presence or absence of ethanol extract of GTH. The expression of proinflammatory cytokines IL-1β, IL-6, and TNF-α, and inducible nitric oxide synthase (iNOS) and transglutaminase 2 (TG2) were assayed by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Matrix metalloproteinase (MMP)-2 and MMP-9 were assayed by gelatin zymography. For detecting uptake of apoptotic cells, RAW264.7 cells were cultured with carboxyfluorescein diacetate (CFDA)-stained apoptotic cells and assayed by flow cytometry.</p> <p>Results</p> <p>The major components of GTH analyzed by high-performance liquid chromatography (HPLC) chromatogram were daidzein (42.5%), epicatechin (28.8%), and naringin (9.4%).</p> <p>GTH treatment inhibited the expression of proinflammatory cytokines IL-1β, IL-6 and MMP-9 but did not affect the expression of TNF-α and iNOS. GTH significantly enhanced the expression of TG2 and the clearance of apoptotic cells by RAW264.7 macrophages.</p> <p>Conclusions</p> <p>GTH inhibits proinflammatory cytokine secretion and MMP-9 activity, enhances apoptotic cell uptake and up-regulates TG2 expression. Our data show that GTH might have beneficial effects on rheumatic diseases.</p

    In vitro and in vivo targeted delivery of IL-10 interfering RNA by JC virus-like particles

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    <p>Abstract</p> <p>Background</p> <p>RNA interference (RNAi) is a powerful tool to silence gene expression post-transcriptionally. Delivering sequences of RNAi <it>in vivo </it>remains a problem. The aim of this study was to use JC virus (JCV) virus-like particles (VLPs) as a vector for delivering RNAi in silencing the cytokine gene of IL-10.</p> <p>Methods</p> <p>JCV VLPs were generated by recombinant JCV VP1 protein in yeast expression system. DNA fragment containing IL-10 shRNA was packaged into VLPs by osmotic shock.</p> <p>Results</p> <p>In RAW 264.7 cells, IL-10 shRNA was found to reduce IL-10 expression by 85 to 89%, as compared with VLPs alone. IL-10 shRNA did not cross-react with TNF-alpha mRNA or influence the expression of TNF-alpha. In BALB/c mice IL-10 shRNA could reduce 95% of IL-10 secretion. Surprisingly, it also down regulated TNF-alpha expression.</p> <p>Conclusions</p> <p>We show for the first time that JCV VLPs empty capsids are competent vectors to deliver RNAi and are nontoxic to cells, suggesting that JCV VLPs is an efficient agent to deliver RNAi in both murine macrophage cells and BALB/c mice. This system provides an efficient means for delivering the RNAi for gene therapy purposes.</p

    Validation of the Action Research Arm Test using item response theory in patients after stroke

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    Objective: To validate the unidimensionality of the Action Research Arm Test (ARAT) using Mokken analysis and to examine whether scores of the ARAT can be transformed into interval scores using Rasch analysis. Subjects and methods: A total of 351 patients with stroke were recruited from 5 rehabilitation departments located in 4 regions of Taiwan. The 19-item ARAT was administered to all the subjects by a physical therapist. The data were analysed using item response theory by non-parametric Mokken analysis followed by Rasch analysis. Results: The results supported a unidimensional scale of the 19-item ARAT by Mokken analysis, with the scalability coefficient H = 0.95. Except for the item pinch ball bearing 3rd finger and thumb'', the remaining 18 items have a consistently hierarchical order along the upper extremity function's continuum. In contrast, the Rasch analysis, with a stepwise deletion of misfit items, showed that only 4 items (grasp ball'', grasp block 5 cm(3)'', grasp block 2.5 cm(3)'', and grip tube 1 cm(3)'') fit the Rasch rating scale model's expectations. Conclusion: Our findings indicated that the 19-item ARAT constituted a unidimensional construct measuring upper extremity function in stroke patients. However, the results did not support the premise that the raw sum scores of the ARAT can be transformed into interval Rasch scores. Thus, the raw sum scores of the ARAT can provide information only about order of patients on their upper extremity functional abilities, but not represent each patient's exact functioning

    The relationship of muscular endurance and coordination and dexterity with behavioral and neuroelectric indices of attention in preschool children

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    This study investigated the associations of non-aerobic fitness (NAF) and motor competence (MC) with attention in 4–6 year-old preschoolers. The allocation of attentional resources and speed of stimulus categorization were examined using the amplitude and latency of P3 of event-related potentials respectively, while cortical activation related to general attention and task-specific discriminative processes were examined using event-related desynchronization (ERD) at lower (8–10 Hz) and upper (10–12 Hz) alpha frequencies, respectively. Seventy-six preschoolers completed NAF (muscular power, muscular endurance, flexibility, balance) and MC (coordination and dexterity, ball skills, agility and balance) test batteries. Electroencephalogram was recorded while participants performed an auditory oddball task. After controlling for age and MC, muscular endurance was positively related to P3 amplitude. MC and its coordination and dexterity sub-component were positively related to task performance, with higher levels of coordination and dexterity showing an additional association with greater upper alpha ERD between 700 and 1000 ms following stimulus onset after controlling for age and NAF. These findings suggest relationships of NAF and MC with early childhood neurocognitive function. Specifically, muscular endurance is related to the neuroinhibition in facilitating effective allocation of attentional resources to stimulus evaluation while coordination and dexterity are related to cortical activation underlying strategic attentional preparation for subsequent stimulus evaluation

    Vascular function in the aging human brain during muscle exertion

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    : To determine how brain oxygenation is stably maintained during advancing age, cerebral oxygenation and hemoglobin were measured real-time at 10 Hz using near-infrared spectroscopy (NIRS) at rest (30 seconds) and during a 10-repeated handgrip strength test (30 seconds) for 834 adults (M/F = 45/55%) aged 20-88 y. The amplitude of cerebral hemodynamic fluctuation was reflected by converting 300 values of % oxygen saturation and hemoglobin of each 30-second phase to standard deviation as indicatives of brain oxygenation variability (BOV) and brain hemodynamic variability (BHV) for each participant. Both BOV (+21-72%) and BHV (+94-158%) increased during the maximal voluntary muscle exertions for all age levels (α &lt; 0.05), suggesting an increased vascular recruitment to maintain oxygen homeostasis in the brain. Intriguingly, BHV was &gt;100 folds for both resting and challenged conditions (α &lt; 0.001) in &gt;80% of adults aged above 50 y despite similar BOV compared with young age counterparts, indicating a huge cost of amplifying hemodynamic oscillation to maintain a stable oxygenation in the aging brain. Since vascular endothelial cells are short-lived, our results implicate a hemodynamic compensation to emergence of daily deficits in replacing senescent endothelial cells after age 50 y

    Induction chemotherapy with dose-modified docetaxel, cisplatin, and 5-fluorouracil in Asian patients with borderline resectable or unresectable head and neck cancer

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    BackgroundSignificant ethnic differences in susceptibility to the effects of chemotherapy exist. Here, we retrospectively analyzed the safety and efficacy of induction chemotherapy (ICT) with dose-modified docetaxel, cisplatin, and 5-fluorouracil (TPF) in Asian patients with borderline resectable or unresectable head and neck squamous cell carcinoma (HNSCC).MethodsBased on the incidence of adverse events that occurred during daily practice, TPF90 (90% of the original TPF dosage; docetaxel 67.5 mg/m2 on Day 1, cisplatin 67.5 mg/m2 on Day 1, and 5-fluorouracil 675 mg/m2 on Days 1–5) was used for HNSCC patients who were scheduled to receive ICT TPF.ResultsBetween March 2011 and May 2014, 52 consecutive patients with borderline resectable or unresectable HNSCC were treated with ICT TPF90 followed by concurrent chemoradiotherapy. Forty-four patients (84.6%) received at least three cycles of ICT TPF90. The most commonly observed Grade 3–4 adverse events included neutropenia (35%), anemia (25%), stomatitis (35%), diarrhea (16%), and infections (13.5%). In an intention-to-treat analysis, the complete and partial response rates after ICT TPF90 were 13.5% and 59.6%, respectively. The complete and partial response rates following radiotherapy and salvage surgery were 42.3% and 25.0%, respectively. The estimated 3-year overall survival and progression-free survival rates were 41% [95% confidence interval (CI): 25–56%] and 23% (95% CI: 10–39%), respectively. The observed median overall survival and progression-free survival were 21.0 months (95% CI: 13.3–28.7 months) and 16.0 months (95% CI: 10.7–21.3 months), respectively.ConclusionTPF90 is a suitable option for Asian patients with borderline resectable or unresectable HNSCC who are scheduled for ICT
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