Influence of Calcium Sulfate Type on Evolution of Reaction Products and Strength in NaOH- and CaO-Activated Ground Granulated Blast-Furnace Slag

This study investigated the influences of CaSO4 type (i.e., anhydrite vs. gypsum) on strength development and reaction products in the activation of ground granulated blast-furnace slag (GGBFS) when different activators (i.e., CaO vs. NaOH) and sources of GGBFS were used. In the CaO-activation, the addition of calcium sulfates greatly enhanced 28-day strengths, regardless of the choice of CaSO4 or GGBFS source, through increasing the quantities of reaction products and reducing pore volume and size. However, in the NaOH-activation, the use of calcium sulfates showed the complex dependency of strength on the choice of CaSO4 type and GGBFS source, and it barely produced beneficial effects on the quantity of reaction products and reduction of pore volume and size. Thus, the results in this study indicate that the combination of CaO-activation and calcium sulfates is a more effective means of activating GGBFS to gain enhanced strength and significant quality control than the use of gypsum with NaOH-activation

Nitric oxide directly activates calcium-activated potassium channels from rat brain reconstituted into planar lipid bilayer

AbstractUsing the planar lipid bilayer technique, we tested whether NO directly activates calcium-activated potassium (Maxi-K) channels isolated from rat brain. We used streptozotocin (STZ) as NO donor, and the NO release was controlled with light. In the presence of 100–800 μM STZ, the Maxi-K channel activity increased up to 3-fold within several tens of seconds after the light was on, and reversed to the control level several minutes after shutting off the light. Similar activation was observed with other NO donors such as S-nitroso-N-acetylpenicillamine and sodium nitroprusside. The degree of activity increase was dependent upon the initial open probability (Pinit). When the Pinit was lower, the activity increase was greater. These results demonstrate that NO can directly affect the Maxi-K channel activity, and suggest that the Maxi-K channel might be one of the physiological targets of NO in brain

Activity of hippocampal adult-born neurons regulates alcohol withdrawal seizures.

Alcohol withdrawal (AW) after chronic alcohol exposure produces a series of symptoms, with AW-associated seizures being among the most serious and dangerous. However, the mechanism underlying AW seizures has yet to be established. In our mouse model, a sudden AW produced 2 waves of seizures: the first wave includes a surge of multiple seizures that occurs within hours to days of AW, and the second wave consists of sustained expression of epileptiform spikes and wave discharges (SWDs) during a protracted period of abstinence. We revealed that the structural and functional adaptations in newborn dentate granule cells (DGCs) in the hippocampus underlie the second wave of seizures but not the first wave. While the general morphology of newborn DGCs remained unchanged, AW increased the dendritic spine density of newborn DGCs, suggesting that AW induced synaptic connectivity of newborn DGCs with excitatory afferent neurons and enhanced excitability of newborn DGCs. Indeed, specific activation and suppression of newborn DGCs by the chemogenetic DREADD method increased and decreased the expression of epileptiform SWDs, respectively, during abstinence. Thus, our study unveiled that the pathological plasticity of hippocampal newborn DGCs underlies AW seizures during a protracted period of abstinence, providing critical insight into hippocampal neural circuits as a foundation to understand and treat AW seizures

Intravenous Vitamin C administration reduces fatigue in office workers: a double-blind randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Studies of the efficacy of vitamin C treatment for fatigue have yielded inconsistent results. One of the reasons for this inconsistency could be the difference in delivery routes. Therefore, we planned a clinical trial with intravenous vitamin C administration.</p> <p>Methods</p> <p>We evaluated the effect of intravenous vitamin C on fatigue in office workers. A group of 141 healthy volunteers, aged 20 to 49 years participated in this randomized, double-blind, controlled clinical trial. The trial group received 10 grams of vitamin C with normal saline intravenously, while the placebo group received normal saline only. Since vitamin C is a well-known antioxidant, oxidative stress was measured. Fatigue score, oxidative stress, and plasma vitamin C levels were measured before intervention, and again two hours and one day after intervention. Adverse events were monitored.</p> <p>Results</p> <p>The fatigue scores measured at two hours after intervention and one day after intervention were significantly different between the two groups (p = 0.004); fatigue scores decreased in the vitamin C group after two hours and remained lower for one day. Trial also led to higher plasma vitamin C levels and lower oxidative stress compared to the placebo group (p < 0.001, p < 0.001, respectively). When data analysis was refined by dividing each group into high-baseline and low-baseline subgroups, it was observed that fatigue was reduced in the lower baseline vitamin C level group after two hours and after one day (p = 0.004). The same did not hold for the higher baseline group (p = 0.206).</p> <p>Conclusion</p> <p>Thus, intravenous vitamin C reduced fatigue at two hours, and the effect persisted for one day. There were no significant differences in adverse events between two groups. High dose intravenous vitamin C proved to be safe and effective against fatigue in this study.</p> <p>Trial Registration</p> <p>The clinical trial registration of this trial is <url>http://ClinicalTrials.gov</url><a href="http://www.clinicaltrials.gov/ct2/show/NCT00633581">NCT00633581</a>.</p

Gypsum-Dependent Effect of NaCl on Strength Enhancement of CaO-Activated Slag Binders

This study explores the combined effect of NaCl and gypsum on the strength of the CaO-activated ground-granulated blast furnace slag (GGBFS) binder system. In the CaO-activated GGBFS system, the incorporation of NaCl without gypsum did not improve the strength of the system. However, with the presence of gypsum, the use of NaCl yielded significantly greater strength than the use of either gypsum or NaCl alone. The presence of NaCl largely increases the solubility of gypsum in a solution, leading to a higher concentration of sulfate ions, which is essential for generating more and faster formations of ettringite in a fresh mixture of paste. The significant strength enhancement of gypsum was likely due to the accelerated and increased formation of ettringite, accompanied by more efficient filling of pores in the system

Исследование систем управления при проектировании информационных систем: учебное пособие

Учебно-методическое пособие предназначено для освоения на практике методов исследования предметной области при проектировании информационных систем. Учебно-методическое пособие содержит теоретический материал по дисциплинам магистерских программ и бакалавриата направления 230400 «Информационные системы и технологии», 230200 «Информационные системы»

Titanium dioxide induces apoptotic cell death through reactive oxygen species-mediated Fas upregulation and Bax activation

Background: Titanium dioxide (TiO2) has been widely used in many areas, including biomedicine, cosmetics, and environmental engineering. Recently, it has become evident that some TiO2 particles have a considerable cytotoxic effect in normal human cells. However, the molecular basis for the cytotoxicity of TiO2 has yet to be defined.Methods and results: In this study, we demonstrated that combined treatment with TiO2 nanoparticles sized less than 100 nm and ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-dependent upregulation of Fas and conformational activation of Bax in normal human cells. Treatment with P25 TiO2 nanoparticles with a hydrodynamic size distribution centered around 70 nm (TiO2P25-70) together with ultraviolet A irradiation-induced caspase-dependent apoptotic cell death, accompanied by transcriptional upregulation of the death receptor, Fas, and conformational activation of Bax. In line with these results, knockdown of either Fas or Bax with specific siRNA significantly inhibited TiO2-induced apoptotic cell death. Moreover, inhibition of reactive oxygen species with an antioxidant, N-acetyl-L-cysteine, clearly suppressed upregulation of Fas, conformational activation of Bax, and subsequent apoptotic cell death in response to combination treatment using TiO2P25-70 and ultraviolet A irradiation.Conclusion: These results indicate that sub-100 nm sized TiO2 treatment under ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-mediated upregulation of the death receptor, Fas, and activation of the preapoptotic protein, Bax. Elucidating the molecular mechanisms by which nanosized particles induce activation of cell death signaling pathways would be critical for the development of prevention strategies to minimize the cytotoxicity of nanomaterials.This work was supported by the Korea Ministry of Environment and The Eco-Technopia 21 Project (091-091-081)