An Adhesive Hydrogel with “Load-Sharing” Effect as Tissue Bandages for Drug and Cell Delivery

Hydrogels with adhesive properties have potential for numerous biomedical applications. Here, the design of a novel, intrinsically adhesive hydrogel and its use in developing internal therapeutic bandages is reported. The design involves incorporation of “triple hydrogen bonding clusters” (THBCs) as side groups into the hydrogel matrix. The THBC through a unique “load sharing” effect and an increase in bond density results in strong adhesions of the hydrogel to a range of surfaces, including glass, plastic, wood, poly(tetrafluoroethylene) (PTFE), stainless steel, and biological tissues, even without any chemical reaction. Using the adhesive hydrogel, tissue-adhesive bandages are developed for either targeted and sustained release of chemotherapeutic nanodrug for liver cancer treatment, or anchored delivery of pancreatic islets for a potential type 1 diabetes (T1D) cell replacement therapy. Stable adhesion of the bandage inside the body enables almost complete tumor suppression in an orthotopic liver cancer mouse model and ≈1 month diabetes correction in chemically induced diabetic mice.     

Modulation of p- and n-Type Transitions in Co3−xNixO4 Nanoparticles for Enhanced Supercapacitor Electrochemical Performance

The efficient storage of electrons and the type of conduction in semiconductor materials are important factors in determining their electrochemical performance. However, the interaction between these two factors is often overlooked by researchers. In this study, the effects of Ni doping at Co_3−xNi_xO₄ nanoparticles on the electronic storage form of the material and resulting changes in the conduction p/n-type are reported. Theoretical calculations demonstrate that n-type conduction with high effective mass of electrons contributes significantly to the redox reaction of electrode materials and is beneficial for improving electrochemical performance. The specific capacitance of Co_3−xNi_xO₄ (x = 0.67) electrode material is 10 times larger than that of Co₃O₄ due to enhanced orbital hybridization caused by Ni atom doping. The findings provide new directions for exploring the mechanism of conductive type conversion of materials and offer insights beyond the traditional approach of considering doping content alone.     

Realizing Ultrahigh Mechanical Flexibility and >15% Efficiency of Flexible Organic Solar Cells via a “Welding” Flexible Transparent Electrode

The power conversion efficiencies (PCEs) of flexible organic solar cells (OSCs) still lag behind those of rigid devices and their mechanical stability is unable to meet the needs of flexible electronics at present due to the lack of a high-performance flexible transparent electrode (FTE). Here, a so-called “welding” concept is proposed to design an FTE with tight binding of the upper electrode and the underlying substrate. The upper electrode consisting of solution-processed Al-doped ZnO (AZO) and silver nanowire (AgNW) network is well welded by utilizing the capillary force effect and secondary growth of AZO, leading to a reduction of the AgNWs junction site resistance. Meanwhile, the poly(ethylene terephthalate) is modified by embedding the AgNWs, which are then used to link with the AgNWs in the upper hybrid electrode, thus enhancing the adhesion of the electrode to the substrate. By this welding strategy, critical bottleneck issues relating to the FTEs in terms of optoelectronic and mechanical properties are comprehensively addressed. The single-junction flexible OSCs based on this welded FTE show a high performance, achieving a record high PCE of 15.21%. In addition, the PCEs of the flexible OSCs are less influenced by the device area and display robust bending durability even under extreme test conditions.     

Transforming the Electrochemical Behaviors of Cobalt Oxide from “Supercapacitator” to “Battery” by Atomic-Level Structure Engineering for Inspiring the Advance of Co-Based Batteries

Cobalt-based electrodes receive emerging attention for their high theoretical capacity and rich valence variation ability, but state-of-the-art cobalt-based electrodes present performance far below the theoretical value. Herein, the in-depth reaction mechanisms in the alkaline electrolyte are challenged and proven to be prone to the surface-redox pseudocapacitor behavior due to the low adsorption energy to  OH. Using the atomic-level structure engineering strategy after substitution metal searching, the adsorption energy is effectively enhanced, and the peak of CoOOH can be observed from in situ characterization for the first time, leading to the successful transition of charge storage behavior from “supercapacitor” to “battery”. When used in a Zn–Co battery as a proof of concept, it shows comprehensive electrochemical performance with a flat discharge voltage plateau of ≈1.7 V, an optimal energy density of 506 Wh kg⁻¹, and a capacity retention ratio of 85.1% after 2000 cycles, shining among the reported batteries. As a practical demonstration, this battery also shows excellent self-discharge performance with the capacity retention of 90% after a 10 h delay. This work subtly tunes the intrinsic electrochemical properties of the cobalt-based material through atomic-level structure engineering, opening a new opportunity for the advance of energy storage systems.     

Permeability of Lipid Membranes for Atomic Tritium or Atom “Slipping” Effect and Its Role in Tritium Planigraphy

The depth of penetration of tritium atoms capable of isotope substitution, generated by thermal dissociation on a tungsten wire (thermal activation of tritium), into a solid target is considered. On the basis of calculations used in the theory of recoil atom stopping, with a lipid bilayer as example, the possibility of penetration of reactive atoms to a depth of up to 5 nm was demonstrated. This result is nicely consistent with the available experimental data. The possibility of slipping of atomic tritium, without loss of its reactivity, into cavities with a decreased electron density was suggested. This phenomenon should be taken into account when interpreting the results of studying biological macromolecules and their complexes by tritium planigraphy.     

Interaction of Mechanical and Electrochemical Factors duringCorrosion Fatigue of Fe-26Cr-1Mo Stainless Steel in 1M H_2SO_4 Solution

The cyclic plastic straining electrode technique has been used to investigate the transient electrochemical behaviour of Fe-26Cr1Mo stainless steel in 1M H2SO4 solution at a passive potential.The influence of plastic strain amplitude and plastic strain rate on the dissolution current response was analysed. The experimental results showed that the transient current was dependent on the competitive process of the surface film rupture and repassivation of the new surface. The high plastic strain amplitude and the high plastic strain rate caused a change of electrochemical activity of specimen surface. In the condition of low strain amplitude and strain rate, the characteristics of current response was mainly relative tp the process of new surface repassivation.The competition kinetics has been analysed through the comparison of plastic strain rate and repassivating rate     

A General “In Situ Etch-Adsorption-Phosphatization” Strategy for the Fabrication of Metal Phosphides/Hollow Carbon Composite for High Performance Liquid/Flexible Zn–Air Batteries

Benefiting from the admirable energy density (1086 Wh kg⁻¹), overwhelming security, and low environmental impact, rechargeable zinc–air batteries (ZABs) are deemed to be attractive candidates for lithium-ion batteries. The exploration of novel oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) bifunctional catalysts is the key to promoting the development of zinc–air batteries. Transitional metal phosphides (TMPs) especially Fe-based TMPs are deemed to be a rational type of catalyst, however, their catalytic performance still needs to be further improved. Considering Fe (heme) and Cu (copper terminal oxidases) are nature's options for ORR catalysis in many forms of life from bacteria to humans. Herein, a general “in situ etch-adsorption-phosphatization” strategy is designed for the fabrication of hollow FeP/Fe₂P/Cu₃P-N, P codoped carbon (Fe P/Cu₃P-NPC) catalyst as the cathode of liquid and flexible ZABs. The liquid ZABs manifest a high peak power density of 158.5 mW cm⁻² and outstanding long-term cycling performance (≈1100 cycles at 2 mA cm⁻²). Similarly, the flexible ZABs deliver superior cycling stability of 81 h at 2 mA cm⁻² without bending and 26 h with different bending angles.     

Effect of strain on “hardening by annealing and softening by deformation” phenomena in ultra-fine grained aluminum

Ultra-fine grained (UFG) metals fabricated by severe plastic deformation (SPD) sometimes exhibit peculiar mechanical properties. For example, the “hardening by annealing and softening by deformation” was reported in UFG aluminum, which was totally opposite to the behaviors of conventionally coarse-grained materials. In this study, the effect of SPD strain on the peculiar phenomena was investigated. The UFG aluminum was fabricated by various cycles of the accumulative roll-bonding (ARB) process with lubrication at ambient temperature. The specimen ARB-processed by ten cycles certainly showed the peculiar phenomena. On the other hand, the 6-cycle specimen did not show the phenomena but was softened by annealing and hardened by deformation normally. From the results of microstructural characterization, it was suggested that the difference in the change of the mechanical property during annealing and deformation between 6-cycle and 10-cycle specimens was caused by the difference in the grain size and/or the texture components, which depended on the SPD strain.     

Possibilities and sustainability of “biomass for power” solutions in the case of a coal-based power utility

This paper investigates the possibilities and the sustainability of “biomass for power” solutions on a real power system. The case example is JP Elektroprivreda BiH d.d.—Sarajevo (EPBiH), a typical conventional coal-based power utility operating in the region of South East Europe. Biomass use is one of the solutions considered in EPBiH as a means of increasing shares of renewable energy sources (RES) in final energy production and reducing CO₂ emissions. This ultimately is a requirement for all conventional coal-based power utilities on track to meet their greenhouse gas (GHG) cut targets by 2050. The paper offers a discussion of possible options as a function of sustainability principles, considering environmental, economic and social aspects of biomass use. In the case of EPBiH, the most beneficial would be waste woody biomass and energy crop co-firing on existing coal-based power plants, as suggested by biomass market analyses and associated technological studies. To assess the sustainability of the different biomass co-firing options, a multicriteria sustainability assessment (MSA) and single criteria analysis (SCA) were used. Four different options were considered, based on different ratios of biomass for co-firing: 0 wt%-reference case, and 5, 7 and 10 wt% of biomass. Both the MSA and the SCA confirmed that the option with the highest share of biomass is the most preferable one for the considered case. In addition to that, the CO₂ parameter proved to be a key sustainability indicator, effecting the most decision making with regard to preference of options from the point of sustainability. Following up on the results of the analyses, the long-term projection of biomass use in EPBiH has shown an increase in biomass utilization of up to 450,000 t/y in 2030 and beyond, with associated CO₂ cuts of up to 395,000 t/y. This resulted in a 4 % CO₂ cut achieved with biomass co-firing, compared to the 1990 CO₂ emission level. It should be noted that the proposed assessment model for biomass use may be applied to any conventional coal-based power utility as an option in contributing to meeting specific CO₂ cut targets, provided that the set of input data is available and reliable.     

Effect of Intensification of Selenium‐Protection Properties in Laboratory Animals Drinking “Flint” Water Due to the Increase in the Coefficient of Diffusion of Selenium in Organs and Tissues

The influence of flint water on the development of biochemical processes which cause the accumulation of selenium in the body of laboratory animals has been studied experimentally. A decrease in the bond energy of the molecule of flint water with the anion SeO₃ ^2– in relation to the bond energy of the molecule of ordinary water and an increase in the coefficient of diffusion of this anion in bone and muscular tissues in filtration of flint water have been substantiated.     

Mechanical and tribological properties of “substrate–material” multifunctional composite with shape memory effect

The properties of steel–TiNi, TiNiCu, NiAl alloy multifunctional composite with shape memory effect are studied. The system is obtained under high-energy exposure (argon arc and laser surfacing, plasma and high-rate gas flame sputtering) with the formation of a structure with fine-grained to nanoscale dispersity. The experimental studies reveal the efficiency of the elaborated technique of the synthesis of composites to increase the wear resistance, fatigue strength, and endurance at frictionally cyclic low-cycle loading of material. The increase in fatigue and wear characteristics are explained by the processes caused by the combined cyclic loading and reverse friction. As is shown, the friction and mechanical fatigue in a surface-modified layer of the material undergoing the shape memory effect in the friction domain causes an increase in temperature that favors the martensite–austenite transformation, whereas the pressure arising in friction induces the transformation plasticity effect owing to the formation of stress martensite.     

Development and Verification of a Scheme for Fractionation of HAWs with TODGA Extractive Agent in a “Light” Diluent

Radiochemistry - The technology of fractionation of trans-plutonium elements (TPEs) and REEs with the use of 0.15 M TODGA (tetraoctylamide of diglycolic acid) + 5% n-decanol in Isopar-M as...     

Theory and practice of “Striping” for improved ON/OFF Ratio in carbon nanonet thin film transistors

A new technique to reduce the influence of metallic carbon nanotubes (CNTs)—relevant for large-scale integrated circuits based on CNT-nanonet transistors—is proposed and verified. Historically, electrical and chemical filtering of the metallic CNTs have been used to improve the ON/OFF ratio of CNT-nanonet transistors; however, the corresponding degradation in ON-current has made these techniques somewhat unsatisfactory. Here, we abandon the classical approaches in favor of a new approach based on relocation of asymmetric percolation threshold of CNT-nanonet transistors by a technique called “striping”; this allows fabrication of transistors with ON/OFF ratio >1000 and ON-current degradation no more than a factor of 2. We offer first principle numerical models, experimental confirmation, and renormalization arguments to provide a broad theoretical and experimental foundation of the proposed method.      

Polymer formulations for “dry” decontamination of the equipment and premises of nuclear power plants

Polymer composite formulations for decontamination were developed on the basis of a polyvinyl alcohol solution as a binder with active additives (HNO₃, HBF₄, 1-hydroxyethane-1,1-diphosphonic acid and its triammonium salt, and a synthetic detergent) and fillers (natural rottenstone; rottenstone modified with nickel and copper ferrocyanides; dolomite modified with nickel ferrocyanide; clinoptilolite modified with iron(III) and calcium chlorides, sodium phosphate, and potassium ferrocyanide; hydrolytic lignin). The developed polymer composite materials (pastes) exhibit high decontaminating ability (DF = 10²–10³) and low adhesion to the tested surfaces of stainless and carbon steels (including painted surfaces), plastic compound, self-leveling floors, and Teflon surface.