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Precise monolayer epitaxy is important for two-dimensional (2D) semiconductors toward future electronics. Here, we report a new self-limited epitaxy approach, liquid phase edge epitaxy (LPEE), for precise-monolayer epitaxy of transition-metal dichalcogenides. In this method, the liquid solution contacts 2D grains only at the edges, which confines the epitaxy only at the grain edges and then precise monolayer epitaxy can be achieved. High-temperature in situ imaging of the epitaxy progress directly supports this edge-contact epitaxy mechanism. Typical transition-metal dichalcogenide monolayers (MX 2 , M = Mo, W, and Re; X = S or Se) have been obtained by LPEE with a proper choice of molten alkali halide solvents (AL, A = Li, Na, K, and Cs; L = Cl, Br, or I). Furthermore, alloying and magnetic-element doping have also been realized by taking advantage of the liquid phase epitaxy approach. This LPEE method provides a precise and highly versatile approach for 2D monolayer epitaxy and can revolutionize the growth of 2D materials toward electronic applications.

The light-up aptamer-dimethylindole red (DIR) complexes have been applied in biochemistry analysis as promising signal transduction tools. However, the unfavorable repulsions between DIR and the long-sequence aptamer switch hinder the complex's further development, and it is urgent to engineer a feasible and efficient strategy for synchronously and rationally adjusting the DIR chemical structure and the DIR aptamer performance. Herein, we communicate a versatile docking-guided rational tailoring strategy to effectively upgrade a DNA aptamer which specifically turns on the fluorescence of a synthesized amino-functionalized DIR analogue (NH 2 -DIR). After optimizing with three-level tailoring strategies including molecule docking-guided tailoring, coarse tailoring, and fine tailoring, the NH 2 -DIR aptamer switch with higher binding affinity and specificity, considerable fluorescence-activation ability, and 40% shortened length was obtained. Integrating the experimental and docking results, the binding mechanism between NH 2 -DIR and the tailored aptamer was deciphered via three types of interactions.

In-memory computing is a highly efficient approach for breaking the bottleneck of von Neumann architectures, i.e., reducing redundant latency and energy consumption during the data transfer between the physically separated memory and processing units. Herein we have designed a in-memory computing device, a van der Waals ferroelectric semiconductor (InSe) based metal-oxide-ferroelectric semiconductor field-effect transistor (MOfeS-FET). This MOfeS-FET integrates memory and logic functions in the same material, in which the out-of-plane (OOP) ferroelectric polarization in InSe is used for data storage and the semiconducting property is used for the logic computation. The MOfeS-FET shows a long retention time with high on/off ratios (>10 6 ), high program/erase (P/E) ratios (10 3 ), and stable cyclic endurance. Moreover, inverter, programmable NAND, and NOR Boolean logic operations with nonvolatile storage of the results have all been demonstrated using our approach. These findings highlight the potential of van der Waals ferroelectric semiconductor-based MOfeS-FETs in the in-memory computing and their potential of achieving size scaling beyond Moore's law.

Background: the primary function of the kidney is to eliminate metabolic waste products and xenobiotics from the circulation. During this process, the kidney may become vulnerable to toxicity., Objective: it was aimed to investigate the impact of thymoquinone (TQ) in mercuric chloride (HgCl 2 )-induced nephrotoxicity through estimation of various proteins involved in natural defense mechanisms., Material and Methods: HgCl 2 (0.4 mg/kg) was administered to all groups ( n = 5) except for the normal control. Three treatment groups received TQ (5, 10, and 15 mg/kg) 60 min before HgCl 2 administration. The protective effect of TQ was evaluated from renal and liver function biomarkers, urine examination, glomerulus filtration rate (GFR), histopathological features, oxidative stress biomarkers, Hsp-70, apoptosis biomarkers, and gene expression., Results: TQ significantly attenuated hazardous effects of HgCl 2 on renal and hepatic tissues. Urine albumin and glucose were considerably low in the treated groups in comparison with the HgCl 2 group. TQ treatment also enhanced % GFR in rats. TQ-enhanced superoxide dismutase, catalase, and glutathione levels by enhancing the expression level of nuclear factor erythroid 2-related factor 2 (Nrf2). TQ increased Hsp-70 and Bcl-2 levels and reduced caspase-3 activity. TQ also protected cells against HgCl 2 -induced cell death and decreased % DNA fragmentation. TQ increased the expression of protective proteins metallothionein I and II and reduced the expression of kidney injury molecule-1 (Kim-1)., Conclusion: TQ showed protective effects against HgCl 2 -induced nephrotoxicity through modifications of various constitutive and inducible protein and enzyme levels in renal tissues., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Symmetry is highly relevant with various quantities and phenomena in physics. While the translational symmetry breaks at the edges of two-dimensional hexagonal crystalline flakes, it is usually associated with the breaking of central inversion symmetry that is yet to be observed in terms of physical properties. Here, we report an experiment-theory joint study on in-plane compressed single-crystal monolayer WS 2 flakes. Although the flakes show a hexagonal appearance with a C 6 symmetry, our density functional theory calculations predict that their in-plane strain, geometric structure, work-function, energy bandgap, and mechanical modulus are nonequivalent among the triangular regions with different edge terminations at the atomic scale, and the flakes exhibit self-patterns with a C 3 symmetry. Such nonequivalence of physical properties and concomitant self-patterns persist even in a 50 μm-sized monolayer WS 2 , observed using atomic force microscopy. This indicates that the symmetry arising from the atomic geometry could preserve up to tens of microns for both geometric and properties of the flake, regardless of its mesoscopic geometry, i.e. , C 6 here. Such a detectable mesoscopic scale and symmetric nano- to mesoscale patterns provide promising building blocks for 2D materials and devices and also allow edge terminations of 2D flakes to be directly distinguished.

The charge density wave (CDW) phase is a macroscopic quantum state with periodic charge density modulation accompanied by periodic lattice distortion in low-dimensional metals. External fields, such as an electric field and optical excitation, can trigger the transitions among different CDW states, leaving an under-explored mechanism and attracting great interest toward optoelectronic applications. Here, we explore a photoinduced phase transition in 1T-TaS 2 under an electrical field. By analyzing the phase transition probability, we obtained a linear dependence of the phase transition barrier on the electric field and laser energy density. Additionally, the threshold laser energy for the phase transition decreases linearly with an increasing applied electrical field. Finally, picojoule photodetection was realized in the visible and near-infrared ranges near the CDW transition edge. Our work will promote the understanding of the CDW phase transition mechanism as well as open pathways for optoelectronic applications.

Three-terminal synaptic transistors are basic units of neuromorphic computing chips, which may overcome the bottleneck of conventional von Neumann computing. So far, most of the three-terminal synaptic transistors use the dielectric layer to change the state of the channel and mimic the synaptic behavior. For this purpose, special dielectric layers are needed, such as ionic liquids, solid electrolytes, or ferroelectric insulators, which are difficult for miniaturization and integration. Here, we report a novel type of synaptic transistors using a two-dimensional ferroelectric semiconductor, i.e., α-In 2 Se 3 , as the channel material to mimic the synaptic behavior for the first time. The essential synaptic behaviors, such as single-spike response, paired-spike response, and multispike response have been experimentally demonstrated. Most importantly, the conventional gate dielectric material of our transistors may facilitate the miniaturization and batch manufacture of synaptic transistors. The results indicate that the three-terminal synaptic transistors based on two-dimensional ferroelectric semiconductors are very promising for neuromorphic systems.

The study presents the comparative bioelectrochemical treatment of phenol in anodic and cathodic compartments of four identical dual chambered microbial fuel cells (MFCs) with bare and multiwalled carbon nanotube/polypyrrole (MWCNT/PPy)-coated electrodes, respectively. It was observed that systems performing biocathodic treatment of phenol performed better as compared to the systems performing bioanodic treatment. The maximum power densities for bioanodic phenol treatment using bare and coated electrodes were found to be 469.038 and 560.719 mW/m 2 , while for biocathodic treatment, they were observed to be 604.804 and 650.557 mW/m 2 , respectively. The MFCs performing biocathodic treatment of phenol consistently showed higher chemical oxygen demand removal efficiency, Coulombic efficiency, and power density and indicated the better performance of the biocathodic bare (B-MFC) and coated (C-MFC) MFCs as compared to the bioanodic B-MFC and C-MFC. UV/vis spectrophotometry revealed that the MWCNT/PPy-coated carbon paper worked significantly better in the treatment of phenol with admirable treatment obtained within a week of the experiment as compared to the system with bare carbon paper. Cyclic voltammetry asserted better electrochemical activity of the MFC systems with coated electrodes in the treatment of phenol. The electrochemical impedance spectroscopy data also supported the better performance of biocathodic phenol treatment with lower internal and charge transfer resistances. The scanning electron microscopy images confirmed the active biofilm formation on the electrode surface. The study indicates MFC as a viable option for the treatment of recalcitrant chemical compounds with energy recovery., Competing Interests: The authors declare no competing financial interest., (Copyright © 2019 American Chemical Society.)

Mixed-dimensional van der Waals (vdW) heterostructures based on two-dimensional (2D) materials exhibit immense potential in infrared optoelectronic applications. However, the weak vdW coupling results in limiting performance of infrared optoelectronic device. Here, we exploit a gapless heterostructure that S dangling bonds of nonlayered PbS are connected to the bonding sites of MoS 2 (with factitious S vacancies) via strong orbital hybridization. The strong interface coupling leads to ultrahigh responsivity and photogain ( G ) exceeding 10 5 , and the detectivity ( D *) is greater than 10 14 Jones. More importantly, the gapless heterostructure shows fast rise and decay times about 47 and 49 μs, respectively, which is 5 orders of magnitude faster than that of transferred vdW heterostructures. Furthermore, an ultrahigh photon-triggered on/off ratio of 1.6 × 10 6 is achieved, which is 4 orders of magnitude higher than that of transferred vdW heterostructures. This architecture can offer an effective approach for advanced infrared optoelectronic devices.

Visible light-driven Ag 2 S-grafted NiO-ZnO ternary nanocomposites are synthesized using a facile and cost-effective homogeneous precipitation method. The structural, morphological, and optical properties were extensively studied, confirming the formation of ternary nanocomposites. The surface area of the synthesized nanocomposites was calculated by electrochemical double-layer capacitance ( C dl S/NiO-ZnO nanocomposites showed excellent visible light photocatalytic property which increases further with the concentration of Ag 2 S. The maximum photocatalytic activity was shown by 8% Ag 2 S/NiO-ZnO with a RhB degradation efficiency of 95%. Hydroxyl and superoxide radicals were found to be dominant species for photodegradation of RhB, confirmed by scavenging experiments. It is noteworthy that the recycling experiments demonstrated high stability and recyclable nature of the photocatalyst. Moreover, the electrochemical results indicated that the prepared nanocomposite exhibits remarkable activity toward detection of acetone. The fabricated nanocomposite sensor showed high sensitivity (4.0764 μA mmol L 2 S/NiO-ZnO with a RhB degradation efficiency of 95%. Hydroxyl and superoxide radicals were found to be dominant species for photodegradation of RhB, confirmed by scavenging experiments. It is noteworthy that the recycling experiments demonstrated high stability and recyclable nature of the photocatalyst. Moreover, the electrochemical results indicated that the prepared nanocomposite exhibits remarkable activity toward detection of acetone. The fabricated nanocomposite sensor showed high sensitivity (4.0764 μA mmol L -1 cm -2 ) and a lower detection limit (0.06 mmol L -1 S/NiO-ZnO can be attributed to the synergistic effects of strong visible light absorption, excellent charge separation, and remarkable surface properties.2 S/NiO-ZnO can be attributed to the synergistic effects of strong visible light absorption, excellent charge separation, and remarkable surface properties., Competing Interests: The authors declare no competing financial interest.

Unactivated aziridines are the core substructures in a plethora of bioactive natural products and serve as building blocks in organic synthesis. Despite this, very limited methods are available to access them directly from olefins, as most of the known methods are devoted to their activated counterparts. Herein, we have developed a highly efficient Rh(II)-catalyzed method for the direct preparation of unactivated aziridines from olefins using O-(sulfonyl)hydroxylamines as the aminating agent. The reactions proceed with a high stereospecificity.

A simple and selective spectrophotometric method has been developed for the first time for the determination of sodium methoxide in methanol solution in the presence of sodium hydroxide. The developed method involves the formation of a pink species by the reaction between sodium methoxide and α-santonin. The pink compound formed shows absorbance maximum at 513 nm. N, N-Dimethylformamide and methanol were used as solvents, and the reaction was performed at different temperatures and 25 °C was selected for further experiments. The pink compound formed was dried and then was studied using FTIR and mass spectrometry. The calibration curve was constructed from 0.10 to 0.30% (m/v) sodium methoxide in methanol, and the standard deviation is 0.010%. Similarly, the relative standard deviations of 28%, 26%, and 24% solutions of sodium methoxide were obtained in the range of 0.4 to 1.9%. The correlation coefficient of the analytical curve r = 0.9997; the limit of detection, LOD, is ca. 1.1 × 10 -3 % w/w; and the limit of quantification, LOQ, is ca. 3.2 × 10 -3 % w/w. The results of analysis were validated statistically.

Transmembrane anion carriers (anionophores) have potential in biological research and medicine, provided high activities can be obtained. There is particular interest in treating cystic fibrosis (CF), a genetic illness caused by deficient anion transport. Previous work has found that anionophore designs featuring axial ureas on steroid and trans-decalin scaffolds can be especially effective. Here we show that replacement of ureas by thioureas yields substantial further enhancements. Six new bis-thioureas have been prepared and tested for Cl(-)/NO3(-) exchange in 1-palmitoyl-2-oleoylphosphatidylcholine/cholesterol large unilamellar vesicles (LUVs). The bis-thioureas are typically >10 times more effective than the corresponding ureas and are sufficiently active that transport by molecules acting singly in LUVs is readily detected. The highest activity is shown by decalin 9, which features N-(3,5-bis(trifluoromethyl)phenyl)thioureido and octyl ester substituents. A single molecule of transporter 9 in a 200 nm vesicle promotes Cl(-)/NO3(-) exchange with a half-life of 45 s and an absolute rate of 850 chloride anions per second. Weight-for-weight, this carrier is only slightly less effective than CFTR, the natural anion channel associated with CF.

An efficient Csp-Csp cross-coupling of alkynyl bromide and pinacol ester of alkynyl boronic acid catalyzed by CuFe2O4 nanoparticles has been accomplished in dimethyl carbonate to produce unsymmetric 1,3-diynes. This protocol is also extended for the Csp-Csp2 coupling of alkynyl bromide and alkenyl boronic acid to provide conjugated 1,3-enynes. The aliphatic, aromatic, and heteroaromatic alkynes couple with various substituted alkynyl/alkenyl boronates/boronic acids by this procedure to furnish a library of 1,3-diynes and enynes in high yields. The catalyst was easily separated by an external magnet and recycled 10 times.

A novel strategy for the direct conversion of aryl- and heteroarylamines to selenides has been developed via diazotization of amines with tert-butyl nitrite in neutral medium followed by reaction with diaryl/diheteroaryl/dialkyl diselenides in one pot under photocatalysis at room temperature in the absence of any metal. This reaction is also applied for the synthesis of tellurides. The selenylation of heteroarylamine by this protocol is of much significance because of the difficulty in diazotization of these molecules by a standard diazotization method in acid medium.

Molecular dynamics simulation has been used to study the specific interactions between poly(ethylene glycol) (PEG) and three drug molecules for which PEG is used to aid delivery: paclitaxel and piroxicam, where PEG is a carrier agent, and hematoporphyrin, where PEG is covalently attached to form a "stealth shield". Simulating at physiological salt concentration, we found no evidence of any specific interaction between paclitaxel or piroxicam with PEG, but found a strong interaction for the case of hematoporphyrin. This interaction is lipophilic in nature, between the nonpolar (CH(2))(2) groups of the PEG and the porphin ring of the hematoporphyrin. This interaction was found to be strong enough that the PEG aggregated to the hematoporphyrin, independent of whether or not it was covalently bound. Interestingly, when the simulation was repeated in absence of salt we found evidence of this interaction being weakened. This led us to hypothesize a previously unforeseen mechanism: interaction with salt cations cause the PEG to coil around the salt ions, each ion binding to many PEG oxygens, increasing the exposure of the nonpolar ethylene groups, thus increasing the effective hydrophobicity of PEG. The Hydrophobic ethylene groups of the PEG chains adhere strongly to the hydrophobic porphin ring. Experiments involving absorption spectra measurements were conducted, and these results also indicated that presence of salt at physiological level increases the effective attractive interaction between PEG and hematoporphyrin. Taken together, our results demonstrate that while PEG, due to its solubility in both polar and nonpolar solvents, may act as a dissolution aid for paclitaxel and piroxicam, of the three drug molecules studied it will only have a protective role for the case of the hematoporphyrin.

Aryl azides undergo clean reduction by copper nanoparticles and ammonium formate in water. The surface hydrogen on copper nanoparticles is considered to be the active reducing species. A variety of functionalized aryl azides and aryl sulfonyl azides are reduced by this procedure to the corresponding amines with excellent chemoselectivity in high yields.

Decalins bearing two axial -NHCONHAr substituents and an ester-linked alkyl side chain have been synthesized and studied as anion receptors and transporters. The design relates to steroid-based "cholapods" but is more compact and less intrinsically lipophilic. Transport rates depend on both NHAr and the alkyl side chain. High activities can be achieved; with optimal substitution, chloride-nitrate exchange across vesicle membranes is measurable at transporter/lipid ratios as low as 1:250,000.