Synthesis of biosourced silica-Ag nanocomposites and amalgamation reaction with mercury in aqueous solutions

This paper focuses on the synthesis of a new silver nanocomposite adsorbent derived from rice husk as raw material. The synthesis is based on triethoxysilane chemistry and the reduction of silver without the aid of reductant chemicals. The derived AgNPs@SiO2 nanocomposites are fully characterized and then used for the removal of mercury (II) from aqueous solutions. The results demonstrated that the affinity of the composite for mercury is high and the removal mechanism is adsorption accompanied by a redox reaction between mercury and silver followed by the formation of calomel and amalgams between silver and mercury. The silver-mercury reaction is complex, and its stoichiometry seems to scale with the silver content. Besides the importance of the surface reactions, the successful implementation of biosourced silica for mercury removal from water is useful for the development of strategies for the valorization of agricultural waste and boosts the concept of circular economy and bioeconomy

Colossal Tunneling Electroresistance in Co-Planar Polymer Ferroelectric Tunnel Junctions

Ferroelectric tunnel junctions (FTJs) are ideal resistance-switching devices due to their deterministic behavior and operation at low voltages. However, FTJs have remained mostly as a scientific curiosity due to three critical issues: lack of rectification in their current-voltage characteristic, small tunneling electroresistance (TER) effect, and absence of a straightforward lithography-based device fabrication method that would allow for their mass production. Co-planar FTJs that are fabricated using wafer-scale adhesion lithography technique are demonstrated, and a bi-stable rectifying behavior with colossal TER approaching 106% at room temperature is exhibited. The FTJs are based on poly(vinylidenefluoride-co-trifluoroethylene) [P(VDF-TrFE)], and employ asymmetric co-planar metallic electrodes separated by &lt;20 nm. The tunneling nature of the charge transport is corroborated using Simmons direct tunneling model. The present work is the first demonstration of functional FTJs manufactured via a scalable lithography-based nano-patterning technique and could pave the way to new and exciting memory device concepts.</p

Sub-second photonic processing of solution-deposited single layer and heterojunction metal oxide thin-film transistors using a high-power xenon flash lamp

We report the fabrication of solution-processed In2O3 and In2O3/ZnO heterojunction thin-film transistors (TFTs) where the precursor materials were converted to their semiconducting state using high power light pulses generated by a xenon flash lamp. In2O3 TFTs prepared on glass substrates exhibited low-voltage operation (≤2 V) and a high electron mobility of ∼6 cm2 V−1 s−1. By replacing the In2O3 layer with a photonically processed In2O3/ZnO heterojunction, we were able to increase the electron mobility to 36 cm2 V−1 s−1, while maintaining the low-voltage operation. Although the level of performance achieved in these devices is comparable to control TFTs fabricated via thermal annealing at 250 °C for 1 h, the photonic treatment approach adopted here is extremely rapid with a processing time of less than 18 s per layer. With the aid of a numerical model we were able to analyse the temperature profile within the metal oxide layer(s) upon flashing revealing a remarkable increase of the layer's surface temperature to ∼1000 °C within ∼1 ms. Despite this, the backside of the glass substrate remains unchanged and close to room temperature. Our results highlight the applicability of the method for the facile manufacturing of high performance metal oxide transistors on inexpensive large-area substrates

High-efficiency fullerene solar cells enabled by a spontaneously formed mesostructured CuSCN-nanowire heterointerface

Fullerenes and their derivatives are widely used as electron acceptors in bulk-heterojunction organic solar cells as they combine high electron mobility with good solubility and miscibility with relevant semiconducting polymers. However, studies on the use of fullerenes as the sole photogeneration and charge-carrier material are scarce. Here, a new type of solution-processed small-molecule solar cell based on the two most commonly used methanofullerenes, namely [6,6]-phenyl-C61-butyric acid methyl ester (PC 60 BM) and [6,6]-phenyl-C71-butyric acid methyl ester (PC 70 BM), as the light absorbing materials, is reported. First, it is shown that both fullerene derivatives exhibit excellent ambipolar charge transport with balanced hole and electron mobilities. When the two derivatives are spin-coated over the wide bandgap p-type semiconductor copper (I) thiocyanate (CuSCN), cells with power conversion efficiency (PCE) of ≈1%, are obtained. Blending the CuSCN with PC 70 BM is shown to increase the performance further yielding cells with an open-circuit voltage of ≈0.93 V and a PCE of 5.4%. Microstructural analysis reveals that the key to this success is the spontaneous formation of a unique mesostructured p-n-like heterointerface between CuSCN and PC 70 BM. The findings pave the way to an exciting new class of single photoactive material based solar cells

The Silk Road Economic Belt: Problems and Perpectives

The paper analyzes current conditions and possible consequences of the PRC’s influence on the socio-economic and environmental development of the Kazakhstan section of the Silk Road Economic Belt (SREB). Geopolitical factors are revealed, which determine, mainly due to China, the provision of high dynamics of the Kazakh economy.В работе анализируются современные условия и возможные последствия влияния КНР на социально-экономическое и экологическое развитие казахстанского участка Экономического пояса Шелкового пути (ЭПШП). Раскрываются геополитические факторы, определяющие, в основном за счет Китая, обеспечение высоких показателей динамики казахстанской экономики

Predictors of tamponade and constriction in patients with pericardial disease undergoing interventional and surgical treatment

The aim of our study was to define predictors of cardiac compression development including clinical, electrocardiographic, echocardiographic, chest-X-ray and perioperative parameters and their diagnostic value. Overall 243 patients with pericardial disease, among them 123 with compression (tamponade, constriction) and 120 without signs of compression were included in the study. Clinical, laboratory, electrocardiographic, chest-X-Ray, echocardiographic and perioperative data were included in the logistic regression analysis to define predictors of tamponade/constriction development. Logistic regression analysis demonstrated large effusion (> 20 mm) (OR 5.393, 95%CI 1.202–24.199, p = 0.028), cardiac chamber collapse (OR 31.426, 95%CI 1.609–613-914, p = 0.023) and NYHA class > 3 (OR 8.671, 95%CI 1.730–43.451, p = 0.009) were multivariable predictors of compression development. The model including these three variables allowed predicting compression in 91.7% of cases. ROC analyses demonstrated that all three variables had significant diagnostic value with sensitivity of 75.6% and specificity of 74.2% for large effusion, low sensitivity and high specificity for cardiac chamber collapse (35% and 92%) and NYHA class (32.5% and 94.2%). The independent predictors of compression development are presence of large effusion > 20 mm, cardiac chamber collapse and high NYHA class. The model including all three parameters allows correctly predicting compression in 91.4% of cases. The diagnostic accuracy of each parameter is characterized by high sensitivity and specificity of large effusion, high specificity of cardiac chamber collapse and NYHA class

Predictors of tamponade and constriction in patients with pericardial disease undergoing interventional and surgical treatment

Objective: The aim of our study was to define predictors of cardiac compression development including clinical, electrocardiographic, echocardiographic, chest-X-ray and perioperative parameters and their diagnostic value. Methods: Overall 243 patients with pericardial disease, among them 123 with compression (tamponade, constriction) and 120 without signs of compression were included in the study. Clinical, laboratory, electrocardiographic, chest-X-Ray, echocardiographic and perioperative data were included in the logistic regression analysis to define predictors of tamponade/constriction development. Results: Logistic regression analysis demonstrated large effusion (>20 mm) (OR 5.393, 95%CI 1.202–24.199, p = 0.028), cardiac chamber collapse (OR 31.426, 95%CI 1.609–613-914, p = 0.023) and NYHA class > 3 (OR 8.671, 95%CI 1.730–43.451, p = 0.009) were multivariable predictors of compression development. The model including these three variables allowed predicting compression in 91.7% of cases. ROC analyses demonstrated that all three variables had significant diagnostic value with sensitivity of 75.6% and specificity of 74.2% for large effusion, low sensitivity and high specificity for cardiac chamber collapse (35% and 92%) and NYHA class (32.5% and 94.2%). Conclusion: The independent predictors of compression development are presence of large effusion >20 mm, cardiac chamber collapse and high NYHA class. The model including all three parameters allows correctly predicting compression in 91.4% of cases. The diagnostic accuracy of each parameter is characterized by high sensitivity and specificity of large effusion, high specificity of cardiac chamber collapse and NYHA class

Large-area plastic nanogap electronics enabled by adhesion lithography

Large-area manufacturing of flexible nanoscale electronics has long been sought by the printed electronics industry. However, the lack of a robust, reliable, high throughput and low-cost technique that is capable of delivering high-performance functional devices has hitherto hindered commercial exploitation. Herein we report on the extensive range of capabilities presented by adhesion lithography (a-Lith), an innovative patterning technique for the fabrication of coplanar nanogap electrodes with arbitrarily large aspect ratio. We use this technique to fabricate a plethora of nanoscale electronic devices based on symmetric and asymmetric coplanar electrodes separated by a nanogap < 15 nm. We show that functional devices including self-aligned-gate transistors, radio frequency diodes and rectifying circuits, multi-colour organic light-emitting nanodiodes and multilevel non-volatile memory devices, can be fabricated in a facile manner with minimum process complexity on a range of substrates. The compatibility of the formed nanogap electrodes with a wide range of solution processable semiconductors and substrate materials renders a-Lith highly attractive for the manufacturing of large-area nanoscale opto/electronics on arbitrary size and shape substrates

A Tri-Channel Oxide Transistor Concept for the Rapid Detection of Biomolecules Including the SARS-CoV-2 Spike Protein

Solid-state transistor sensors that can detect biomolecules in real time are highly attractive for emerging bioanalytical applications. However, combining upscalable manufacturing with the required performance remains challenging. Here, an alternative biosensor transistor concept is developed, which relies on a solution-processed In 2O 3/ZnO semiconducting heterojunction featuring a geometrically engineered tri-channel architecture for the rapid, real-time detection of important biomolecules. The sensor combines a high electron mobility channel, attributed to the electronic properties of the In 2O 3/ZnO heterointerface, in close proximity to a sensing surface featuring tethered analyte receptors. The unusual tri-channel design enables strong coupling between the buried electron channel and electrostatic perturbations occurring during receptor–analyte interactions allowing for robust, real-time detection of biomolecules down to attomolar (am) concentrations. The experimental findings are corroborated by extensive device simulations, highlighting the unique advantages of the heterojunction tri-channel design. By functionalizing the surface of the geometrically engineered channel with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody receptors, real-time detection of the SARS-CoV-2 spike S1 protein down to am concentrations is demonstrated in under 2 min in physiological relevant conditions.</p