731 research outputs found

    High Glucose Accelerates Autophagy in Adult Rat Intervertebral Disc Cells

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    Study DesignIn vitro cell culture.PurposeThe purpose of this study was to investigate the effect of high glucose on autophagy in adult rat intervertebral disc cells.Overview of LiteratureDiabetes mellitus is considered to be an important etiologic factor for intervertebral disc degeneration, resulting in degenerative disc diseases. A glucose-mediated increase of autophagy is a major causative factor for the development of diseases associated with diabetes mellitus. However, no information is available for the effect of high glucose on autophagy in adult intervertebral disc cells.MethodsNucleus pulposus and annulus fibrosus cells were isolated from 24-week-old adult rats, cultured and placed in either 10% fetal bovine serum (normal control) or 10% fetal bovine serum plus two different high glucose concentrations (0.1 M and 0.2 M) (experimental conditions) for one and three days, respectively. The expressions of autophagy markers, such as beclin-1, light chain 3-I (LC3-I) and LC3-II, autophagy-related gene (Atg) 3, 5, 7 and 12, were identified and quantified.ResultsTwo high glucoses significantly increased the expressions of beclin-1, LC3-II, Atg3, 5, 7, and 12 in adult rat nucleus pulposus and annulus fibrosus cells in a dose- and time-dependent manner. The ratio of LC3-II/LC3-I expression was also increased in a dose-respectively time-dependent manner.ConclusionsThe results suggest that autophagy of adult nucleus pulposus and annulus fibrosus cells might be a potential mechanism for the intervertebral disc degeneration in adult patients with diabetes mellitus. Thus, the prevention of autophagy in adult intervertebral disc cells might be considered as a novel therapeutic target to prevent or to delay the intervertebral disc degeneration in adult patients with diabetes mellitus

    Indoor formaldehyde removal over CMK-3

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    The removal of formaldehyde at low concentrations is important in indoor air pollution research. In this study, mesoporous carbon with a large specific surface area was used for the adsorption of low-concentration indoor formaldehyde. A mesoporous carbon material, CMK-3, was synthesized using the nano-replication method. SBA-15 was used as a mesoporous template. The surface of CMK-3 was activated using a 2N H2SO4 solution and NH3 gas to prepare CMK-3-H2SO4 and CMK-3-NH3, respectively. The activated samples were characterized by N2 adsorption-desorption, X-ray diffraction, and X-ray photoelectron spectroscopy. The formaldehyde adsorption performance of the mesoporous carbons was in the order of CMK-3-NH3 > CMK-3-H2SO4 > CMK-3. The difference in the adsorption performance was explained by oxygen and nitrogen functional groups formed during the activation process and by the specific surface area and pore structure of mesoporous carbon

    Phospholipase D1 Mediates AMP-Activated Protein Kinase Signaling for Glucose Uptake

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    Glucose homeostasis is maintained by a balance between hepatic glucose production and peripheral glucose utilization. In skeletal muscle cells, glucose utilization is primarily regulated by glucose uptake. Deprivation of cellular energy induces the activation of regulatory proteins and thus glucose uptake. AMP-activated protein kinase (AMPK) is known to play a significant role in the regulation of energy balances. However, the mechanisms related to the AMPK-mediated control of glucose uptake have yet to be elucidated.Here, we found that AMPK-induced phospholipase D1 (PLD1) activation is required for (14)C-glucose uptake in muscle cells under glucose deprivation conditions. PLD1 activity rather than PLD2 activity is significantly enhanced by glucose deprivation. AMPK-wild type (WT) stimulates PLD activity, while AMPK-dominant negative (DN) inhibits it. AMPK regulates PLD1 activity through phosphorylation of the Ser-505 and this phosphorylation is increased by the presence of AMP. Furthermore, PLD1-S505Q, a phosphorylation-deficient mutant, shows no changes in activity in response to glucose deprivation and does not show a significant increase in (14)C-glucose uptake when compared to PLD1-WT. Taken together, these results suggest that phosphorylation of PLD1 is important for the regulation of (14)C-glucose uptake. In addition, extracellular signal-regulated kinase (ERK) is stimulated by AMPK-induced PLD1 activation through the formation of phosphatidic acid (PA), which is a product of PLD. An ERK pharmacological inhibitor, PD98059, and the PLD inhibitor, 1-BtOH, both attenuate (14)C-glucose uptake in muscle cells. Finally, the extracellular stresses caused by glucose deprivation or aminoimidazole carboxamide ribonucleotide (AICAR; AMPK activator) regulate (14)C-glucose uptake and cell surface glucose transport (GLUT) 4 through ERK stimulation by AMPK-mediated PLD1 activation.These results suggest that AMPK-mediated PLD1 activation is required for (14)C-glucose uptake through ERK stimulation. We propose that the AMPK-mediated PLD1 pathway may provide crucial clues to understanding the mechanisms involved in glucose uptake

    The impact of non-pharmaceutical interventions on premature births during the COVID-19 pandemic: a nationwide observational study in Korea

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    BackgroundNon-pharmaceutical interventions (NPIs), such as social distancing and hand washing, have been associated with a decline in the preterm birth rate worldwide. We aimed to evaluate whether the preterm birth rate in Korea during the coronavirus disease 2019 lockdown has changed compared to that in previous years.MethodA birth registry from the Korea Statistical Information Service, which is a nationwide official database, was used to include all births claimed to have occurred between 2011 and 2020. Newborns with gestational age (GA) less than 22 weeks and birth weight less than 220 g were excluded. The pre-NPI period was designated as January 2011 to January 2020, and the NPI period was defined as February 2020 to December 2020. We assessed the effect of NPI on the incidence of prematurity per 100 births using an interrupted time-series quasi-experimental design and implementing an autoregressive integrated moving average (ARIMA) model.ResultsFrom 2011 to 2020, a total of 3,931,974 live births were registered, among which 11,416 were excluded. Consequently, the final study population included 3,920,558 live births (both singleton and multiple births) among which 275,009 (7.0%) were preterm. The preterm birth rate was significantly higher during the NPI period (8.68%) compared to that in the pre-NPI period (6.92%) (P < 0.001). The ARIMA model showed that in all singleton and multiple births, except those in July (observed 9.24, expected 8.54, [95% prediction interval {PI} 8.13–8.96], percent difference 7.81%), September (observed 7.89, expected 8.35, [95% PI 7.93–8.76], percent difference −5.66%), and December (observed 9.90, expected 9.40, [95% PI 8.98–9.82], percent difference 5.2%), most observed values were within the 95% PI of the expected values and showed an increasing trend.ConclusionIn this nationwide observational study, the trend in premature birth rate did not significantly change due to NPI implementation in Korea, as it had been increasing since 2011. The trend of Korea's birth rate appears to be unaffected by the implementation of NPIs; however, further studies with a longer follow-up period are needed

    Outcomes of endovascular treatment for aortic pseudoaneurysm in Behcet's disease

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    ObjectiveTo evaluate the effectiveness of endovascular stent grafting for surgical management of aortic pseudoaneurysm in patients with Behcet's disease (BD).MethodsWe present a single-institution retrospective cohort of patients with aortic pseudoaneurysm and BD treated with aortic stent grafting. Computed tomography imaging was obtained preoperatively in all patients and once within 2 weeks postoperatively, and then annually. Clinical follow-up and erythrocyte sedimentation rate were used to follow BD activity. Immunosuppressant therapy was instituted prior to endovascular treatment unless a contraindication existed.ResultsFrom 1998 to 2012, 10 patients (eight male, two female; median age, 39) with BD and aortic pseudoaneurysm were treated with endovascular stent grafting at this institution. Ninety percent of these patients received immunosuppressive therapy before and after surgical treatment. The median follow-up period was 57 months (interquartile range, 43-72). The locations of the 12 pseudoaneurysms treated in this cohort were infrarenal abdominal aorta (seven), descending thoracic aorta (four), and aortic arch (one). Median pseudoaneurysm size was 4.5 cm (interquartile range, 3.4-5.9). At long-term follow-up, complete resolution of the aortic pseudoaneurysm was noted in all patients. No endoleaks occurred. Newly developed pseudoaneurysm at the distal margin of the stent graft was noted in one patient 17 months after the stent graft procedure. One patient required a subsequent stent graft placement for an expanding pseudoaneurysm of the subclavian artery. No patient deaths occurred during the follow-up period.ConclusionsEndovascular treatment of aortic pseudoaneurysm with stent-grafting in patients with BD is safe and effective with long-term durability

    Output Effect Evaluation Based on Input Features in Neural Incremental Attribute Learning for Better Classification Performance

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    [[abstract]]Machine learning is a very important approach to pattern classification. This paper provides a better insight into Incremental Attribute Learning (IAL) with further analysis as to why it can exhibit better performance than conventional batch training. IAL is a novel supervised machine learning strategy, which gradually trains features in one or more chunks. Previous research showed that IAL can obtain lower classification error rates than a conventional batch training approach. Yet the reason for that is still not very clear. In this study, the feasibility of IAL is verified by mathematical approaches. Moreover, experimental results derived by IAL neural networks on benchmarks also confirm the mathematical validation.[[notice]]補正完畢[[incitationindex]]SCI[[booktype]]電子

    Silicon carbide-free graphene growth on silicon for lithium-ion battery with high volumetric energy density

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    Silicon is receiving discernable attention as an active material for next generation lithium-ion battery anodes because of its unparalleled gravimetric capacity. However, the large volume change of silicon over charge-discharge cycles weakens its competitiveness in the volumetric energy density and cycle life. Here we report direct graphene growth over silicon nanoparticles without silicon carbide formation. The graphene layers anchored onto the silicon surface accommodate the volume expansion of silicon via a sliding process between adjacent graphene layers. When paired with a commercial lithium cobalt oxide cathode, the silicon carbide-free graphene coating allows the full cell to reach volumetric energy densities of 972 and 700 Whl(-1) at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial lithium-ion batteries. This observation suggests that two-dimensional layered structure of graphene and its silicon carbide-free integration with silicon can serve as a prototype in advancing silicon anodes to commercially viable technology.
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