724 research outputs found

    Skewed Factor Models Using Selection Mechanisms

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    Traditional factor models explicitly or implicitly assume that the factors follow a multivariate normal distribution; that is, only moments up to order two are involved. However, it may happen in real data problems that the first two moments cannot explain the factors. Based on this motivation, here we devise three new skewed factor models, the skew-normal, the skew-t, and the generalized skew-normal factor models depending on a selection mechanism on the factors. The ECME algorithms are adopted to estimate related parameters for statistical inference. Monte Carlo simulations validate our new models and we demonstrate the need for skewed factor models using the classic open/closed book exam scores dataset

    Back Extensor Strengthening Exercise and Backpack Wearing Treatment for Camptocormia in Parkinson's Disease: A Retrospective Pilot Study

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    Objective To investigate the effect of a conservative treatment regime in Parkinson's disease patients with camptocormia. Methods Nine patients with Parkinson's disease were included in a retrospective pilot study of the value of back extensor strengthening exercise. Six inpatients received a 30-minute treatment, twice daily for 5 weeks, being treated on average for 34 days; while three outpatients visited the clinic and were educated for home exercise and backpack wearing treatment. Outpatients should be scheduled to visit the outpatient department to check physical status every 2–4 weeks for an average of 3 months. Results All patients except one showed statistically significant improvements in activities of daily living (ADL) and motor symptoms, as measured by flexion angle at standing posture, Unified Parkinson's Disease Rating Scale (UPDRS) II and III, and modified Hoehn-Yahr staging. Conclusion Conservative treatment is effective in postural correction of camptocormia in Parkinson's disease, as well as improvement in ADL and motor symptoms

    Robust Co-catalytic Performance of Nanodiamonds Loaded on WO3 for the Decomposition of Volatile Organic Compounds under Visible Light

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    Proper co-catalysts (usually noble metals), combined with semiconductor materials, are commonly needed to maximize the efficiency of photocatalysis. Search for cost-effective and practical alternatives for noble-metal co-catalysts is under intense investigation. In this work, nanodiamond (ND), which is a carbon nanomaterial with a unique sp(3)(core)/sp(2)(shell) structure, was combined with WO3 (as an alternative co-catalyst for Pt) and applied for the degradation of volatile organic compounds under visible light. NDs-loaded WO3 showed a highly enhanced photocatalytic activity for the degradation of acetaldehyde (similar to 17 times higher than bare WO3), which is more efficient than other well-known co-catalysts (Ag, Pd, Au, and CuO) loaded onto WO3 and comparable to Pt-loaded WO3. Various surface modifications of ND and photoelectochemical measurements revealed that the graphitic carbon shell (sp(2)) on the diamond core (spa) plays a crucial role in charge separation and the subsequent interfacial charge transfer. As a result, ND/WO3 showed much higher production of OH radicals than bare WO3 under visible light. Since ND has a highly transparent characteristic, the light shielding that is often problematic with other carbon-based co-catalysts was considerably lower with NDs-loaded WO3. As a result, the photocatalytic activity of NDs/WO3 was higher than that of WO3 loaded with other carbon-based co-catalysts (graphene oxide or reduced graphene oxide). A range of spectroscopic and photo(electro)chemical techniques were systematically employed to investigate the properties of NDs-loaded WO3. ND is proposed as a cost-effective and practical nanomaterial to replace expensive noble-metal co-catalysts.1124Ysciescopu

    Use of a Tunneling Technique to Achieve a Lower Defibrillation Threshold during Implantable Cardioverter Defibrillator Implantation via the Right Subclavian Vein

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    A 56-yr-old man with aborted sudden cardiac death underwent implantable cardioverter defibrillator (ICD) implantation. While the ICD was being implanted, a left subclavian venogram failed to visualize the left subclavian vein, which was attributed to likely prolonged indwelling of the left subclavian sheath for venous access. Accordingly, the right subclavian vein was punctured and the ICD lead was diverted from the right side area to the active Can in the left pectoral area by tunneling over the sternum for high defibrillation threshold. The approach used in this case may be considered in patients who had difficult left subclavicular venous access and it may be prudent to save the left subclavian vein for ICD implantation in patients with fatal tachyarrhythmia

    Boosting Up the Low Catalytic Activity of Silver for H2 Production on Ag/TiO2 Photocatalyst: Thiocyanate as a Selective Modifier

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    Noble metal cocatalysts like Pt have been widely employed as an essential ingredient in many kinds of photocatalytic materials for solar hydrogen production. The high material cost of Pt is the biggest limitation. Silver is far less expensive but much less active than Pt and Au as a hydrogen evolving catalyst. Here we demonstrate a new strategy to boost up the activity of silver in Ag/TiO2 for photocatalytic H-2 production via forming a simple surface complexation of thiocyanate (SCN-) on silver. The addition of thiocyanate in the suspension of Ag/TiO2 markedly enhanced the photocatalytic production of H-2 by about 4 times. Thiocyanate was not consumed at all during the photoreaction, which ruled out the role of thiocyanate as an electron donor. Such a positive role of thiocyanate was not observed with bare TiO2, Pt/TiO2, and Au/TiO2. The selective chemisorption of thiocyanate on silver was confirmed by the analyses of Raman spectroscopy and spot-profile energy-dispersive spectroscopy. In the presence of thiocyanate, the overpotential for water reduction on Ag/TiO2 electrode was slightly reduced, and the interfacial charge transfer resistance on Ag/TiO2 (measured by electrochemical impedance spectroscopy) was significantly decreased, whereas other electrode systems (bare TiO2, Au/TiO2, and Pt/TiO2) showed the opposite effect of thiocyanate. These results indicate that the adsorption of thiocyanate on Ag facilitates the transfer of photogenerated electrons on the Ag/TiO2 electrode. It is proposed that the formation of Ag-SCN surface complex enhances the interfacial electron transfer rate and facilitates the reduction of protons on Ag/TiO2.115640Ysciescopu

    Successful Catheter Ablation of Atrial Tachycardia Originating from the Non-coronary Aortic Sinus

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    We report a rare case of atrial tachycardia originating from the non-coronary aortic sinus. After failed radiofrequency (RF) energy applications at right His-bundle region, the complete elimination of atrial tachycardia was achieved with an RF energy application in the non-coronary aortic sinus. With the review of other papers, this report emphasizes the importance of mapping in the non-coronary aortic sinus in focal atrial tachycardia near the atrioventricular node or near the Hisbundle
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