2,286 research outputs found
Thermoelectric properties of graphene incorporated thermoelectric materials
Thermoelectric materials, which can change the waste heat into the usable electricity, are interested in various field of applications such as vehicle, ship, power plane, and so on. To enhance the thermoelectric properties, high electrical conductivity, high Seebeck coefficient, and low thermal conductivity should be conducted, however, the trade-off relation between electronic property and thermal property in terms of carrier concentration could be the bottle-neck on the enhancement of thermoelectric properties of the materials. In this presentation, we discuss with the graphene incorporation in the conventional thermoelectric materials, which could lead to independently control electric and thermal properties
Poly(ADP-ribose)polymerase-1 modulates microglial responses to amyloid β
<p>Abstract</p> <p>Background</p> <p>Amyloid β (Aβ) accumulates in Alzheimer's disease (AD) brain. Microglial activation also occurs in AD, and this inflammatory response may contribute to disease progression. Microglial activation can be induced by Aβ, but the mechanisms by which this occurs have not been defined. The nuclear enzyme poly(ADP-ribose) polymerase-1 (PARP-1) regulates microglial activation in response to several stimuli through its interactions with the transcription factor, NF-κB. The purpose of this study was to evaluate whether PARP-1 activation is involved in Aβ-induced microglial activation, and whether PARP-1 inhibition can modify microglial responses to Aβ.</p> <p>Methods</p> <p>hAPP<sub>J20 </sub>mice, which accumulate Aβ with ageing, were crossed with PARP-1<sup>-/- </sup>mice to assess the effects of PARP-1 depletion on microglial activation, hippocampal synaptic integrity, and cognitive function. Aβ peptide was also injected into brain of wt and PARP-1<sup>-/- </sup>mice to directly determine the effects of PARP-1 on Aβ-induced microglial activation. The effect of PARP-1 on Aβ-induced microglial cytokine production and neurotoxicity was evaluated in primary microglia cultures and in microglia-neuron co-cultures, utilizing PARP-1<sup>-/- </sup>cells and a PARP-1 inhibitor. NF-κB activation was evaluated in microglia infected with a lentivirus reporter gene.</p> <p>Results</p> <p>The hAPP<sub>J20 </sub>mice developed microglial activation, reduced hippocampal CA1 calbindin expression, and impaired novel object recognition by age 6 months. All of these features were attenuated in hAPP<sub>J20</sub>/<it>PARP-1<sup>-/- </sup></it>mice. Similarly, Aβ<sub>1-42 </sub>injected into mouse brain produced a robust microglial response in wild-type mice, and this was blocked in mice lacking PARP-1 expression or activity. Studies using microglial cultures showed that PARP-1 activity was required for Aβ-induced NF-κB activation, morphological transformation, NO release, TNFα release, and neurotoxicity. Conversely, PARP-1 inhibition increased release of the neurotrophic factors TGFβ and VEGF, and did not impair microglial phagocytosis of Aβ peptide.</p> <p>Conclusions</p> <p>These results identify PARP-1 as a requisite and previously unrecognized factor in Aβ-induced microglial activation, and suggest that the effects of PARP-1 are mediated, at least in part, by its interactions with NF-κB. The suppression of Aβ-induced microglial activation and neurotoxicity by PARP-1 inhibition suggests this approach could be useful in AD and other disorders in which microglial neurotoxicity may contribute.</p
An Optimization of Composition Ratio among Triple-Filled Atoms in In
Bulk nanostructured materials are important as energy materials. Among thermoelectric materials, the skutterudite system of CoSb3 is a representative material of bulk nanostructured materials. Filling a skutterudite structure with atoms that have different localized frequencies (also known as triple filling) was reported to be effective for lowering thermal conductivity. Among studies representing superior power factors, In-filled skutterudite systems showed higher Seebeck coefficients. This study sought to optimize the composition ratio among the triple-filled atoms in an In0.3-x-yBaxCeyCo4Sb12 system. The composition dependence of the thermoelectric properties was investigated for specimens with different ratios among the three kinds of filler atoms in the In0.3-x-yBaxCeyCo4Sb12 system. In addition, the process variables were carefully optimized for filled skutterudite systems to obtain a maximum ZT value
Risk of Developing Hypertension in Atopic Dermatitis Patients Receiving Long-term and Low-dose Cyclosporine: A Nationwide Population-based Cohort Study
BACKGROUND: Cyclosporine (CS) is a first-line immunosuppressive agent used to manage moderate to severe atopic dermatitis (AD). To date, the risk of developing hypertension associated with the long-term use of low-dose CS in AD patients is understudied.
OBJECTIVE: To determine the cumulative dose-dependent effect of CS on the risk of developing hypertension in patients with AD.
METHODS: A nationwide population-based retrospective cohort with 1,844,009 AD patients was built from the Korean National Health Insurance System database from 2005 to 2009. A Cox proportional-hazard regression analysis was performed according to patients\u27 CS treatment history adjusted for potential confounders.
RESULTS: Current use of CS was associated with an increased risk of developing hypertension (adjusted hazard ratio, 4.442; 95% confidence interval, 3.761-5.247). Among the current CS users, a higher cumulative dose of CS (≥39,725 mg) or longer cumulative use of CS (≥182 days), was significantly associated with an increased risk of developing hypertension.
CONCLUSION: The incidence of CS-associated hypertension is very low when using low-dose treatment regimens for AD. However, the current use or a high cumulative dose of CS for treating patients with AD increases the risk of developing hypertension. Precaution is needed when prescribing CS for long-term treatment of AD
Associations Between Systemic Inflammatory Markers Based on Blood Cells and Polysomnographic Factors in Obstructive Sleep Apnea
Objectives. Systemic inflammation plays a key role in the pathogenesis of obstructive sleep apnea (OSA); however, easy-to-use methods to evaluate the severity of systemic inflammation have yet to be developed. This study investigated the association between systemic inflammation markers that could be derived from the complete blood count (CBC) profile and sleep parameters in a large number of patients with OSA. Methods. Patients who visited our hospital’s Otorhinolaryngology Sleep Clinic between January 2017 and April 2022 underwent polysomnography and routine laboratory tests, including a CBC. Associations between three systemic inflammatory markers—the systemic immune-inflammation index (SII), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR)—and polysomnographic and demographic factors including age, sex, body mass index, the apnea-hypopnea index (AHI), the hypopnea index (HI), lowest oxygen saturation (%), the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale, and percentages of non-rapid eye movement (REM) sleep stage 3, REM sleep, and snoring time were analyzed. The inflammation markers were compared among OSA subgroups, and associations were also analyzed in subgroups with different OSA severities. Results. In total, 1,102 patients (968 men and 134 women) were included, and their mean AHI was 33.0±24.3. PSQI was significantly associated with SII (P=0.027). No independent significant factors were identified for the NLR or PLR. Within the simple snoring and mild OSA subgroups, no significant association was found between sleep parameters and the SII. In the severe OSA subgroup, the AHI (P=0.004) and PSQI (P=0.012) were independently associated with the SII. Conclusion. Our study analyzed systemic inflammatory markers based on the CBC, a simple, relatively cost-effective test, and showed that the AHI and SII were significantly correlated only in the severe OSA subgroup
Anesthetic consideration for patients with severe tracheal obstruction caused by thyroid cancer -A report of 2 cases-
To achieve safe airway management, it is essential first to predict whether there will be difficulties in intubating or ventilating the patient's airway. An enlarged thyroid mass can produce a tracheal obstruction by compression or intraluminal invasion or both. We report two patients with thyroid cancer that obstructed the trachea by compression or invasion. There was no difficulty in endotracheal intubation of the patients with marked thyroid enlargement or in securing passage of the endotracheal tube through the compressed or narrowed portion of the trachea
Seasonal Sea Surface Temperature Asymmetry in the Northwestern Pacific Marginal Seas
Sea surface temperature (SST) is an important component of climate and weather systems at various time scales. Asymmetric seasonal SST variations in the Northwestern Pacific Marginal Seas (NWPMS) are investigated in this study using observation data and numerical model results. The asymmetry in SST seasonal variation is estimated quantitatively and compared with heat advection and surface net heat flux using SST data and atmospheric variables from the European Centre for Medium-Range Weather Forecast (ECMWF). The SST increases faster than it decreases, whereas air temperature increases slowly. Heat advection and surface heat flux were estimated using numerically modeled SST and ocean currents, which contribute to the asymmetry of seasonal SST variations. Heat advection shows good correlation with the SST seasonal variation asymmetry. Model results without currents along the boundary show more symmetrical SST variations. This suggests that heat advection is a prominent cause of asymmetry in the seasonal variation
Mucoid Degeneration of Both ACL and PCL
Unlike meniscal tears and chondral defects, the mucoid degeneration of the anterior cruciate ligament (ACL) is a rare cause of knee pain and there have been no case reports of mucoid degeneration of both the ACL and the posterior cruciate ligament (PCL). A 48-year-old-male patient presented with knee pain and limitation of motion. The patient's magnetic resonance imaging, arthroscopic findings, and pathologic diagnosis confirmed a clinical diagnosis of mucoid degeneration of both the ACL and the PCL. The symptoms disappeared after arthroscopic partial excision of the ACL and PCL
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