Enhanced stability of the optical responses from all-inorganic perovskite nanocrystals embedded in a synthetic opal matrix.

Nanostructured luminescent materials based on perovskite nanocrystals (p-NCs) are attractive since their optical properties can be tuned in a wide spectral range with high luminescence quantum yields and lifetimes, however, they lack stability. In this work, the optical properties of highly luminescent colloidal p-NCs (CsPbX3, where X = Cl/Br, Br, I) embedded in porous opal matrices are presented. It is shown that the photoluminescence of the p-NCs embedded into opal matrices possess increased longtime stability of its spectral and kinetic parameters under ambient conditions. LEDs based on the developed materials show pure color p-NC emission with stability of its parameters. The results of this work may expand the knowledge of interactions between luminescent nanoparticles within multicomponent nanostructured materials for further photonic applications.

Direct laser writing of barriers with controllable permeability in porous glass.

Barriers were produced in porous glass through its local bulk density modification by direct femtosecond writing accompanied by СО2-laser surface thermal densification, to make functional microfluidic elements separated by such physical barriers with different controlled permeability. The separation of multi-component solutions into individual components with different molecule sizes (molecular separation) was performed in this first integrated microfluidic device fabricated in porous glass. Its application in the environmental gas-phase analysis was demonstrated.

Intravenous Treatment With Coenzyme Q10 Improves Neurological Outcome and Reduces Infarct Volume After Transient Focal Brain Ischemia in Rats.

Coenzyme Q10 (CoQ10) crosses the blood-brain barrier when administered intravenously and accumulates in the brain. In this study, we investigated whether CoQ10 protects against ischemia-reperfusion injury by measuring neurological function and brain infarct volumes in a rat model of transient focal cerebral ischemia. In male Wistar rats, we performed transient middle cerebral artery occlusion (tMCAO) for 60 minutes, followed by reperfusion for 24 hours or 7 days. Forty-five minutes after the onset of occlusion (or 15 minutes before reperfusion), rats received a single intravenous injection of solubilized CoQ10 (30 mg·mL(-1)·kg(-1)) or saline (2 mL/kg). Sensory and motor function scores and body weights were obtained before the rats were killed by decapitation, and brain infarct volumes were calculated using tetrazolium chloride staining. CoQ10 brain levels were measured by high-performance liquid chromatography with electrochemical detection. CoQ10 significantly improved neurological behavior and reduced weight loss up to 7 days after tMCAO (P < 0.05). Furthermore, CoQ10 reduced cerebral infarct volumes by 67% at 24 hours after tMCAO and 35% at 7 days (P < 0.05). Cerebral ischemia resulted in a significant reduction in endogenous CoQ10 in both hemispheres (P < 0.05). However, intravenous injection of solubilized CoQ10 resulted in its increase in both hemispheres at 24 hours and in the contralateral hemisphere at 7 days (P < 0.05). Our results demonstrate that CoQ10 is a robust neuroprotective agent against ischemia-reperfusion brain injury in rats, improving both functional and morphological indices of brain damage.

Prospects of Intravenous Coenzyme Q10 Administration in Emergency Ischemic Conditions.

Coenzyme CoQ10 (CoQ10) is an endogenous lipid-soluble antioxidant that effectively protects lipids, proteins, and DNA from oxidation due to its ability to undergo redox transitions between oxidized and reduced forms. Various oxidative stress-associated infectious and somatic diseases have been observed to disrupt the balance of CoQ10 concentration in tissues. As a high molecular weight polar lipophilic compound, CoQ10 exhibits very limited oral bioavailability, which restrains its therapeutic potential. Nevertheless, numerous studies have confirmed the clinical efficacy of CoQ10 therapy through oral administration of high doses over extended time periods. Experimental studies have demonstrated that in emergency situations, intravenous administration of both oxidized and reduced-form CoQ10 leads to a rapid increase in its concentration in organ tissues, offering protection for organ tissues in ischemic conditions. This suggests that the cardio- and neuroprotective efficacy of intravenously administered CoQ10 forms could present new opportunities in treating acute ischemic conditions. Based on these findings, the review provides reasoning supporting further research and implementation of CoQ10 dosage forms for intravenous administration in emergency situations into clinical practice.

Effects of Coenzyme Q10 on the Biomarkers (Hydrogen, Methane, SCFA and TMA) and Composition of the Gut Microbiome in Rats.

The predominant route of administration of drugs with coenzyme Q10 (CoQ10) is administration per os. The bioavailability of CoQ10 is about 2-3%. Prolonged use of CoQ10 to achieve pharmacological effects contributes to the creation of elevated concentrations of CoQ10 in the intestinal lumen. CoQ10 can have an effect on the gut microbiota and the levels of biomarkers it produces. CoQ10 at a dose of 30 mg/kg/day was administered per os to Wistar rats for 21 days. The levels of gut microbiota biomarkers (hydrogen, methane, short-chain fatty acids (SCFA), and trimethylamine (TMA)) and taxonomic composition were measured twice: before the administration of CoQ10 and at the end of the experiment. Hydrogen and methane levels were measured using the fasting lactulose breath test, fecal and blood SCFA and fecal TMA concentrations were determined by NMR, and 16S sequencing was used to analyze the taxonomic composition. Administration of CoQ10 for 21 days resulted in a 1.83-fold (p = 0.02) increase in hydrogen concentration in the total air sample (exhaled air + flatus), a 63% (p = 0.02) increase in the total concentration of SCFA (acetate, propionate, butyrate) in feces, a 126% increase in butyrate (p = 0.04), a 6.56-fold (p = 0.03) decrease in TMA levels, a 2.4-fold increase in relative abundance of Ruminococcus and Lachnospiraceae AC 2044 group by 7.5 times and a 2.8-fold decrease in relative representation of Helicobacter. The mechanism of antioxidant effect of orally administered CoQ10 can include modification of the taxonomic composition of the gut microbiota and increased generation of molecular hydrogen, which is antioxidant by itself. The evoked increase in the level of butyric acid can be followed by protection of the gut barrier function.

New Composite Contrast Agents Based on Ln and Graphene Matrix for Multi-Energy Computed Tomography.

The subject of the current research study is aimed at the development of novel types of contrast agents (CAs) for multi-energy computed tomography (CT) based on Ln-graphene composites, which include Ln (Ln = La, Nd, and Gd) nanoparticles with a size of 2-3 nm, acting as key contrasting elements, and graphene nanoflakes (GNFs) acting as the matrix. The synthesis and surface modifications of the GNFs and the properties of the new CAs are presented herein. The samples have had their characteristics determined using X-ray photoelectron spectroscopy, X-Ray diffraction, transmission electron microscopy, thermogravimetric analysis, and Raman spectroscopy. Multi-energy CT images of the La-, Nd-, and Gd-based CAs demonstrating their visualization and discriminative properties, as well as the possibility of a quantitative analysis, are presented.

Influence of Alloying Elements on the Mechanical Properties of Anodized Aluminum and on the Adhesion of Copper Metallization.

The active development of the power electronics market and a constant increase in the prices of components require new materials and approaches, including a power module packaging technology. The use of aluminum instead of copper in the power module baseplate is an interesting and promising solution. The insulated metal baseplate is one of the most extensively developed technologies nowadays. The object of this study is an insulated metal substrate based on anodized aluminum. The main goal of the article is the comparison of copper topology adhesion to an anodized aluminum oxide layer formed on different aluminum alloys with aluminum content of at least 99.3 wt %. Peel test and pull-off adhesions showed a twofold difference for both aluminum alloys. The high ordered defect-free anodized alumina formed on alloys with copper content of 0.06 wt % had a mean pull-off adhesion of 27 N/mm2 and hardness of 489 HV. In the case of the alloy with copper content of around 0.15 wt %, it had hardness of 295 HV and a mean pull-off adhesion of 12 N/mm2. The results of our microstructure investigation showed that anodized alumina based on alloys with copper content of around 0.15 wt % is fragile due to spherical holes. Summing up the results, it can be concluded that not all initial impurities are critical for anodized alumina, but some, specifically copper, dramatically decreased the mechanical properties of anodized alumina.

Porous flower-like superstructures based on self-assembled colloidal quantum dots for sensing.

Quantum dots (QDs) have been envisaged as very promising materials for the development of advanced optical sensors. Here we report a new highly porous luminescent material based on colloidal QDs for potential applications in optical sensing devices. Bulk flower-like porous structures with sizes of hundreds of microns have been produced by slow destabilization of QD solution in the presence of a non-solvent vapor. The porous highly luminescent material was formed from CdSe QDs using the approach of non-solvent destabilization. This material demonstrated a 4-fold decrease in PL signal in the presence of the ammonia vapor. The relationship between the destabilization rate of QDs in solution and the resulting morphology of structural elements has been established. The proposed model of bulk porous flower-like nanostructured material fabrication can be applied to nanoparticles of different nature combining their unique properties. This research opens up a new approach to design novel multi-component composite materials enabling potential performance improvements of various photonic devices.

Beneficial effect of coenzyme Q10 injection on nitric oxide -related dilation of the rat aorta.

This study examined whether coenzyme Q10 can improve nitric oxide (NO)-dependent vasodilatation in the rat aorta after pre-incubation or intravenous administration. In initial experiments, intact isolated aortic rings were incubated with coenzyme Q10 or L-arginine. In further experiments, coenzyme Q10 was administered intravenously in anesthetized rats, then in 2h aorta was isolated. In both cases, after preliminary preparation the isolated aortic rings were tested for acetylcholine-induced NO-dependent relaxation. Acetylcholine elicited concentration-dependent relaxation of phenylephine precontracted aortic rings. Relaxant responses to acetylcholine were markedly potentiated after pre-incubation with coenzyme Q10 or L-arginine. The maximum relaxant responses (%) were significantly increased from 64.1±5.3 (control) to 89.8±3.0 and 83.6±3.0 (coenzyme Q10 and L-arginine, respectively). pD2 (-lgEC50) value in control study was 5.81±0.28, after pretreatment with coenzyme Q10 or L-arginine were 7.59±0.16 and 7.26±0.32, respectively. There was no difference between coenzyme Q10 and L-arginine groups. After intravenous administration, the relaxant responses to acetylcholine were significantly increased in coenzyme Q10-treated group (94.2±2.0) compared with controls (68.1±4.4). pD2 values were also different between control and treatment groups (5.79±0.29 vs. 8.14±0.65, respectively). Thus, coenzyme Q10 improved NO-mediated vasodilation in rat aorta in magnitude close to the effects of L-arginine - substrate for eNOS. Our data first show that exogenous coenzyme Q10 through intravenous administration is able to improve rapidly NO-dependent vasodilation in rat aorta, likely due to accumulation of coenzyme Q10 in the vessel wall. Improvement of endothelial function can contribute, at least in part, to beneficial effects of coenzyme Q10 in cardiovascular diseases associated with endothelial dysfunction.

Endothelin-converting enzyme inhibition in the rat model of acute heart failure: heart function and neurohormonal activation.

Endothelin-1 (ET-1) has been implicated in many cardiovascular diseases, including acute heart failure (AHF) due to myocardial ischemia. Previously we described the oral endothelin-converting enzyme (ECE) inhibitor, PP36, and in this study, we investigated its cardioprotective effect in more detail, and examined the role of PP36 in the neurohormonal activation in rats that had been subjected to acute myocardial ischemia due to the microsphere embolization of coronary microcirculation. PP36 treatment (3.5 x 10(-5) M/kg/day) led to a significant fourfold decrease in hypertensive response when big-ET-1 was administered to healthy, conscious rats. ECE inhibition did not affect mortality during the first 48 hours after ischemia initiation. Systemic hemodynamic, heart function, and neurohormonal activation were analyzed in the healthy control group, the AHF group, and the AHF+PP36 group two days after AHF induction. In conscious rats in the AHF+PP36 group, mean arterial pressure (MAP) was restored and became similar to that of the MAP of the control group. In anesthetized rats, in the AHF+PP36 group, MAP was not restored and was 22% lower than the MAP of the control group. Myocardial contractility was partially restored and cardiac relaxation significantly improved after PP36 application. Further analysis of cardiac output and peripheral resistance in anesthetized rats revealed no differences between the AHF group and the AHF+PP36 group. There were no differences in plasma ET-1 concentration, serum angiotensin converting enzyme activity, and in the adrenal glands' catecholamine content between the AHF group and the AHF+PP36 group. However, rats in the AHF+PP36 group demonstrated a 60% decrease in cardiac endothelial nitric oxide synthase (eNOS) protein expression, and a 56% reduction of myocardial norepinephrine release, when compared with the AHF group's animals. These results suggest that PP36 can preserve heart function during the recovery from acute ischemic injury, and may modulate the cardiac norepinephrine release and eNOS protein level.