Rapa functionalized carbon dots (Rapa-CDs) were target-oriented synthesized via free radical polymerization combination with hydrothermal carbonization technology. Rapa-CDs has a high synthetic yield ...of 63%. The solubility of Rapa-CDs with 9.41 g is improved 3.6×104 times higher than that of Rapa (2.6×10-4 g). Rapa-CDs show the ability to scavenge ROS, and suppress cell senescence via anti-oxidative stress and mTOR.
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•Rapa-CDs with synthetic yield of 63% were target-oriented synthesized.•Rapa-CDs increase Rapa solubility by 3.6 × 104 times and show ROS scavenging ability.•Rapa-CDs suppress vascular cell senescence via anti-oxidative stress and mTOR.
Suppression of vascular cell senescence is of great significance in preventing cardiovascular diseases such as hypertension and atherosclerosis. The oxidative stress damage caused by reactive oxygen species (ROS) can lead to cellular senescence. Rapamycin (Rapa) is well known to suppress cell senescence via mammalian target of rapamycin (mTOR) pathway. However, poor water solubility and lack of ROS scavenging ability limit the further development of Rapa. To improve the solubility of Rapa and endow with ROS scavenging ability, Rapa functionalized carbon dots (Rapa-CDs) are target-oriented synthesized via free radical polymerization combination with hydrothermal carbonization. Rapa-CDs improve the solubility of Rapa and show ROS scavenging abilities. The solubility of Rapa-CDs with 9.41 g is improved 3.6 × 104 times higher than that of Rapa (2.6 × 10-4 g). The half maximal inhibitory concentration (IC50) of Rapa-CDs toward hydroxyl radical (•OH) and 2,2-Diphenyl-1-picrylhydrazyl free radical (DPPH•) are 0.18 and 0.17 mg/mL, respectively. Rapa-CDs show anti-oxidative stress effect in HEVECs (Human Umbilical Vein Endothelial Cells) via reducing ROS levels by 87 %. Rapa-CDs alleviate HUVECs senescence by suppressing mTOR overactivation, attenuate the expression of P53, P21 and P16. The study demonstrates the target-oriented synthesis of drugs functionalized CDs with anti-senescence via dual-pathway of anti-oxidative stress and mTOR.
The temporal nature of static and dynamic deformation of fibre metal laminates is discussed here. The aim of the study is to verify the proposed innovate model using layered composites. The modified ...relaxation model is based on the earlier formulated plasticity relaxation model for homogeneous materials. The proposed relaxation model makes it possible to describe the deformation of the layered composites from elastic to irreversible deformation, finalised by the failure moment. The developed approach allows us to consider the effects of the transition from static to dynamic loading. This means that the model-calculated dynamic limiting characteristics of the metal and the strength of brittle materials will have a determining character, depending on the loading history. The verification of the model using a glass fibre reinforced aluminium composite, glass fibre reinforced titanium composite, carbon fibre reinforced aluminium composite, and Kevlar fibre reinforced aluminium composite with different thickness ratios between metal and polymer layers is given. It is shown that the theoretical deformation curves of the metal composites at the various strain rates, finalised by brittle fracture of the polymer layers or continued irreversible deformation of remaining unbroken metal layers with destroyed polymer (fibre/epoxy) layers, are predicted. Based on the same structural−temporal parameters for five (Ti/GFRP (0/90)/Ti/GFRP(90/0)/Ti) and three (Ti/GFRP(0/90/90/0)/Ti) layers glass fibre reinforced titanium composites and the polymer layers, one-stage and two-stage stress drops during the irreversible deformation of the composite under static and dynamic loading are simulated. The change of the multi-stage fracture of the composite from static to dynamic loading and the fracture characteristic times of the polymer (100 s and 15,400 s) and the metal (8.4 ms) are correlated. Continued plastic deformation of the composite after fracture of the polymer layers is related with different values of the characteristic relaxation times of the polymer (fibre/epoxy) and the metal layers.
The bone-targeting mechanism of clinic bisphosphonate-type drugs, such as alendronate, risedronate, and ibandronate, relies on chelated calcium ions on the surface of the bone mineralized matrix for ...the treatment of osteoporosis. EGTA with aminocarboxyl chelating ligands can specifically chelate calcium ions. Inspired by the bone-targeting mechanism of bisphosphonates, we hypothesize that EGTA-derived carbon dots (EGTA-CDs) hold bone-targeting ability. For the target-oriented synthesis of EGTA-CDs and to endow CDs with bone targeting, we designed calcium ion chelating agents as precursors, including aminocarboxyl chelating agents (EGTA and EDTA) and bisphosphonate agents (ALN and HEDP) for the target-oriented synthesis of aminocarboxyl-derived CDs (EGTA-CDs and EDTA-CDs) and bisphosphonate-derived CDs (ALN-CDs and HEDP-CDs) with high synthetic yield. The synthetic yield of EGTA-CDs reached 87.6%. Aminocarboxyl-derived CDs and bisphosphonate-derived CDs retain the chelation ability of calcium ions and can specifically bind calcium ions. The chemical environment bone-targeting value coordination constant K and chelation sites of EGTA-CDs were 6.48 × 104 M–1 and 4.12, respectively. A novel method was established to demonstrate the bone-targeting capability of chelate-functionalized carbon dots using fluorescence quenching in a simulated bone trauma microenvironment. EGTA-CDs exhibit superior bone-targeting ability compared with other aminocarboxyl-derived CDs and bisphosphonate-derived CDs. EGTA-CDs display exceptional specificity toward calcium ions and better bone affinity than ALN-CDs, suggesting their potential as novel bone-targeting drugs. EGTA-CDs with strong calcium ion chelating ability have calcium ion affinity in simulated body fluid and bone-targeting ability in a simulated bone trauma microenvironment. These findings offer new avenues for the development of advanced bone-targeting strategies.
Triphenylphosphine functionalized carbon dots (TPP-CDs) showcase robust mitochondria targeting capacity owing to their positive electrical properties. However, TPP-CDs typically involve complicated ...synthesis steps and time-consuming postmodification procedures. Especially, the one-step target-oriented synthesis of TPP-CDs and the regulation of TPP linkage modes remain challenges. Herein, we propose a free-radical-initiated random copolymerization in combination with hydrothermal carbonation to regulate the TPP backbone linkage for target-oriented synthesis of triphenylphosphine copolymerization carbon dots (TPPcopoly-CDs). The linkage mechanism of random copolymerization reactions is directional, straightforward, and controllable. The TPP content and IC50 of hydroxyl radicals scavenging ability of TPPcopoly-CDs are 53 wt % and 0.52 mg/mL, respectively. TPP serves as a charge control agent to elevate the negatively charged CDs by 20 mV. TPPcopoly-CDs with negative charge can target mitochondria, and in the corresponding mechanism the TPP moiety plays a crucial role in targeting mitochondria. This discovery provides a new perspective on the controlled synthesis, TPP linkage modes, and mitochondrial targeting design of TPP-CDs.
This paper presents the first results of a study of the LH transition on the new spherical Globus-M2 tokamak using the Doppler backscattering (DBS) diagnostic. New data characterizing the H-mode of ...discharges with higher values of the plasma parameters, such as magnetic field B
up to 0.9 T and plasma current I
up to 450 kA, were collected and analyzed. An upgraded neutral beam injection (NBI) system was used to initiate the LH transition. DBS allows the measurement of the poloidal rotation velocity and the turbulence amplitude of the plasma. The multi-frequency DBS system installed on Globus-M2 can simultaneously collect data in different areas spanning from the separatrix to the plasma core. This allowed for the radial profiles of the rotation velocity and electric field to be calculated before and after the LH transition. In addition, the values and temporal evolution of the velocity shear were obtained. The associated turbulence suppression after the transition to the H-mode was investigated using DBS.
The synthesis of photothermal carbon/hydroxyapatite composites poses challenges due to the binding modes and relatively low photothermal conversion efficiency. To address these challenges, the ...calcium ions chelated by photothermal carbon dots (PTC-CDs) served as the calcium source for the synthesis of photothermal carbon dots chelated hydroxyapatite (PTC-HA) filler via the coprecipitation method. The coordination constant K and chelation sites of PTC-HA were 7.20 × 102 and 1.61, respectively. Compared to PTC-CDs, the coordination constant K and chelation sites of PTC-HA decreased by 88 and 35% due to chelating to hydroxyapatite, respectively. PTC-HA possesses fluorescence and photothermal performance with a 62.4% photothermal conversion efficiency. The incorporation of PTC-HA filler significantly enhances as high as 76% the adhesion performance of the adhesive hydrogel. PTC-HA with high photothermal conversion efficiency and enhancing adhesion performance holds promise for applications in high photothermal conversion efficiency, offering tissue adhesive properties and fluorescence capabilities to the hydrogel.
Nanotubular iron(III) oxide electrodes are optimized for catalytic efficiency in the water oxidation reaction at neutral pH. The nanostructured electrodes are prepared from anodic alumina templates, ...which are coated with Fe2O3 by atomic layer deposition. Scanning helium ion microscopy, X‐ray diffraction, and Raman spectroscopy are used to characterize the morphologies and phases of samples submitted to various treatments. These methods demonstrate the contrasting effects of thermal annealing and electrochemical treatment. The electrochemical performances of the corresponding electrodes under dark conditions are quantified by steady‐state electrolysis and electrochemical impedance spectroscopy. A rough and amorphous Fe2O3 with phosphate incorporation is critical for the optimization of the water oxidation reaction. For the ideal pore length of 17 μm, the maximum catalytic turnover is reached with an effective current density of 140 μA cm−2 at an applied overpotential of 0.49 V.
Rough it up: The efficiency of iron oxide electrodes for electrochemical water oxidation at neutral pH is optimized by macropore structuration, surface roughening, and phosphate incorporation. We use anodic alumina as a macroporous template, atomic layer deposition to coat the pore walls, and electrochemical treatments to increase the surface roughness and incorporate phosphate.
The paper presents an assessment of the development prospects and transport accessibility of organic production zones in the regions of Siberia based on data from state information systems of the ...Russian Federation and open information systems of commercial digital aggregators. The assessment was carried out with the use of technologies and analytics of the ArcGIS 10.6 program. The Novosibirsk, Omsk, Barnaul, and Tomsk agglomerations have concentrated clusters of investment projects for the processing of agricultural products. The eastern part of the macrozone is characterized by more focal investment activity, the largest of which is the eastern agglomeration of Krasnoyarsk. Investment projects in Kuzbass and the Irkutsk region are dispersed along the main transport routes. The republics of Altai and Tyva and the northern municipalities of the Tomsk and Irkutsk regions remain on the periphery of active transport contacts. Inside the highway part of the region there are areas of low efficiency in the use of transport potential, which makes it possible to increase the investment attractiveness of individual agricultural locations based on a combination of interspecies interaction.
Surfaces functionalized with metal nanoparticles (NPs) are of great interest due to their wide potential applications in sensing, biomedicine, nanophotonics, etc. However, the precisely controllable ...decoration with plasmonic nanoparticles requires sophisticated techniques that are often multistep and complex. Here, we present a laser-induced deposition (LID) approach allowing for single-step surface decoration with NPs of controllable composition, morphology, and spatial distribution. The formation of Ag, Pt, and mixed Ag-Pt nanoparticles on a substrate surface was successfully demonstrated as a result of the LID process from commercially available precursors. The deposited nanoparticles were characterized with SEM, TEM, EDX, X-ray diffraction, and UV-VIS absorption spectroscopy, which confirmed the formation of crystalline nanoparticles of Pt (3-5 nm) and Ag (ca. 100 nm) with plasmonic properties. The advantageous features of the LID process allow us to demonstrate the spatially selective deposition of plasmonic NPs in a laser interference pattern, and thereby, the formation of periodic arrays of Ag NPs forming diffraction grating.
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