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[Image: see text] Isoreticular chemically stable two-dimensional imine covalent organic frameworks (COFs), further denoted as DUT-175 and DUT-176, are obtained in a reaction of 4,4′-bis(9H-carbazol-9-yl)biphenyl tetraaldehyde with phenyldiamine and benzidine. The crystal structures, solved and refined from the powder X-ray diffraction data and confirmed by high-resolution transmission electron microscopy, indicate AA-stacked layer structures. Both structures feature distorted hexagonal channel pores, assuring remarkable porosity (S(BET) = 1071 m(2) g(–1) for DUT-175 and S(BET) = 1062 m(2) g(–1) for DUT-176), as confirmed by adsorption of gases and vapors. The complex conjugated π system of the COFs involves electron-rich carbazole building units, which in combination with the imine groups allow reversible pH-dependent protonation of the frameworks, accompanied by charge transfer and shift of the absorption bands in the UV–vis spectrum. The sigmoidal shape of the water vapor adsorption and desorption isotherms with a steep adsorption step at p/p(0) = 0.4–0.6 in combination with excellent stability over dozens of adsorption and desorption cycles ranks these COFs among the best materials for indoor humidity control applications.

The feasibility of improving typical biohydrometallurgical operation to minimize copper losses was investigated by the use of biogenic iron precipitate for the uptake of Cu(II) ions from aqueous solutions. The iron precipitate was obtained from mineral sulfide bioleaching and characterized using SEM/EDS, XRD, FTIR, BET, TGA, and pHpzc analyses. The results show that the precipitate is highly heterogeneous and that Cu(II) ion adsorption can be described by both Freundlich and Langmuir adsorption isotherms, with a maximum adsorption capacity of 7.54 mg/g at 30 °C and 150 mg/L. The sorption followed pseudo-second-order kinetics, while the major presence of −OH and −NH2 functional groups initiated a chemisorption mechanism through an ion-exchange pathway for the process. Ionic Cu(II) (radius (0.72 Å)) attached easily to the active sites of the precipitate than hydrated Cu(II) (radius (4.19 Å)). With an estimated activation energy of 23.57 kJ/mol, the obtained thermodynamic parameters of ΔS° (0.034–0.050 kJ/mol K), ΔG° (8.37–10.64 kJ/mol), and ΔH° (20.07–23.81 kJ/mol) indicated that the adsorption process was chemically favored, nonspontaneous, and endothermic, respectively. The 43% Cu(II) removal within 60 min equilibrium contact time at pH 5 was indicative of the reduced efficiency of copper extraction observed in a real-life biohydrometallurgical process due to sorption by the iron precipitate. The result of this study might provide an insight into the management of the biohydrometallurgical process to minimize copper losses. It may also help mitigate environmental pollution caused by the disposal of these biogenic iron precipitate residues.

Nanocomposite hydrogels are attracting significant interest due to their potential use in drug delivery systems and tissue scaffolds. Stimuli-responsive hydrogel nanocomposites are of particular interest due to sustained release of therapeutic agents from the hydrogel. However, challenges such as controlled release of therapeutic agents exist because of limited understanding of the interactions between the therapeutic agent and the hydrogel. To investigate the interaction, we synthesize a hydrogel nanocomposite by crosslinking the hydrogel precursors (tetrazine-modified polyethylene glycol and norbornene-modified hyaluronic acid) using click chemistry while bovine serum albumin-capped silver nanoparticles were encapsulated in situ in the matrix. The interaction between the nanoparticles and the hydrogel was studied by a combination of spectroscopic techniques. X-ray photoelectron spectroscopy results suggest that the hydrogel molecule rearranges so that polyethylene glycol is pointing up toward the surface while hyaluronic acid folds to interact with bovine serum albumin of the nanoparticles. Hyaluronic acid, facing inward, may interact with the nanoparticle via hydrogen bonding. The hydrogel nanocomposite showed antibacterial activity against Gram-positive/Gram-negative bactericides, supporting time-based nanoparticle release results. Our findings about interactions between the nanoparticles and the hydrogel can be useful in the formulation of next generation of hydrogel nanocomposites.

Water containing suspended nanobubbles is utilized in various applications. The observed lifetime of suspended nanobubbles is several weeks, whereas, according to the classical theory of bubble stability, a nanosized bubble should dissolve within microseconds. Explanations for the longevity of nanosized bubbles have been proposed but none of them has gained general acceptance. In this study, we derive an explanation for the existence of metastable nanobubbles solely from the thermodynamic principles. According to our analysis, the dissolution of nanosized aqueous bulk bubbles is nonspontaneous below 180 nm diameter due to the energy requirement of gas dissolution. Hydrophobic surfaces have a further stabilizing effect, and the dissolution becomes nonspontaneous in surface nanobubbles having a diameter below 600 nm.

Vibrational strong coupling is emerging as a promising tool to modify molecular properties by making use of hybrid light-matter states known as polaritons. Fabry-Perot cavities filled with organic molecules are typically used, and the molecular concentration limits the maximum reachable coupling strength. Developing methods to increase the coupling strength beyond the molecular concentration limit are highly desirable. In this Letter, we investigate the effect of adding a gold nanorod array into a cavity containing pure organic molecules using FT-IR microscopy and numerical modeling. Incorporation of the plasmonic nanorod array that acts as artificial molecules leads to an order of magnitude increase in the total coupling strength for the cavity with matching resonant frequency filled with organic molecules. Additionally, we observe a significant narrowing of the plasmon line width inside the cavity. We anticipate that these results will be a step forward in exploring vibropolaritonic chemistry and may be used in plasmon based biosensors.

Indole-3-acetamides (1–24) were synthesized via coupling of indole-3-acetic acid with various substituted anilines in the presence of coupling reagent 1,1-carbonyldiimidazole. The structures of synthetic molecules were elucidated through different spectroscopic techniques including electron ionization-mass spectroscopy (EI-MS), 1H-, 13C NMR, and high-resolution EI-MS (HREI-MS). These compounds were screened for their antihyperglycemic and antioxidant potentials. All compounds displayed good to moderate inhibition against α-amylase enzyme with IC50 values ranging between 1.09 ± 0.11 and 2.84 ± 0.1 μM compared to the standard acarbose (IC50 = 0.92 ± 0.4 μM). Compound 15 (IC50 = 1.09 ± 0.11 μM) was the most active compound of the series and exhibited good inhibition against α-amylase; in addition, this compound also exhibited good antioxidant potential with IC50 values of 0.35 ± 0.1 and 0.81 ± 0.25 μM in 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, respectively. The binding interactions of synthetic molecules with the enzyme’s active site were confirmed via in silico studies. The current study had identified a number of lead molecules as potential antihyperglycemic and antioxidant agents.

Ferrimagnetic materials have the assembly of n-type porous semiconductors that shows the evidence of several physical properties used in electronic devices and technology. If the water vapors are brought closer to the surface of n-type semiconductors, then the electrons near the surface of materials are transferred from the conduction band to the electron-accepting level of the water molecule that provides chemisorbed layer of OH- ions. The conduction of electrons takes place only when H3O+ releases one proton to the nearest water molecule that accepts electrons while releasing another proton and so on. This mechanism is known as the Grotthuss chain reaction; it is the essential conduction mechanism of water and surface layers of water on the humidity-sensitive semiconducting materials. In this article, the humidity-sensing properties of Li-substituted cobalt ferrite nanoparticles prepared by the solution combustion method are reported. The result of the data suggested that the substitution of Li ions improved the formation of smaller grains of cobalt ferrite, which results in a rise within the surface area and improved the humidity sensitivity of ferrite nanoparticles.

Direct visualization of soft organic molecules like cellulose is extremely challenging under a high-energy electron beam. Herein, we adopt two ionization damage extenuation strategies to visualize the lattice arrangements of the β-(1→4)-d-glucan chains in carboxylated nanocellulose fibers (C-NCFs) having cellulose II crystalline phase using high-resolution transmission electron microscopy. Direct imaging of individual nanocellulose fibrils with high-resolution and least damage under high-energy electron beam is achieved by employing reduced graphene oxide, a conducting material with high electron transmittance and Ag

Trichloroethylene (TCE) is used as a solvent in various industrial processes. During its use, TCE vaporizes and its vapor pollutes the working atmosphere. Its recovery is very important and activated carbon may be used for this purpose. In the present study, experiments were conducted with activated carbon particles for adsorption and desorption of TCE vapor. The adsorption isotherms were measured over a temperature range of 30–100 °C. Also, the effects of particle sizes (dp; 355, 500, and 710 μm), initial concentration of TCE vapor (100, 150, 200, and 250 ppm), and temperature (30, 50, and 100 °C) on the adsorption isotherms of TCE on activated carbon with air as the carrier stream were investigated, which were not reported earlier. From the experimental results, it was found that as the particle size decreases the adsorption capacity increases because of the increase in surface area with decrease in size of particles. The effect of the initial concentration of TCE vapor showed proportionality with adsorption capacity. The increase in temperature showed increase in the adsorption capacity. The adsorption isotherms obtained from the experimental results were compared with model isotherms viz. Langmuir and Freundlich. The Langmuir and Freundlich isotherm models showed accurate fits with R2 values of 0.99067 and 0.99142, respectively, suggesting a hybrid adsorption mechanism involving monolayer and multilayer adsorption. From the desorption study, it was found that the recovery of TCE–vapor from activated carbon is possible, and hence its reuse. This study confirms the suitability of activated carbon as an adsorbent for the removal of TCE vapors emitted from industrial and domestic sources. The details of the experiments and results are discussed in this article.

Combination of drugs is extensively used to treat chronic inflammatory disease. Naringin (NAR), sulforaphane (SFN), and phenethyl isothiocyanate (PEITC) are nutraceuticals with promising anti-inflammatory properties. However, their clinical effectiveness gets hindered because of low aqueous solubility and poor bioavailability. In the current study, two combinations of liposome (NAR + SFN and NAR + PEITC) were prepared and studied thoroughly in different in vivo models of acute and chronic models of inflammation. The encapsulation efficiency of NAR, SFN, and PEITC in the combination liposomal formulations (CLFs) prepared with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/cholesterol/1,2-distearoyl-sn-glycero-3-phosphoethanolamine -020CN (15:4:1 M ratio) was determined to be 79.8 ± 4.2, 46.5 ± 3.6, and 78.5 ± 3.2%, respectively. The CLFs were characterized by differential scanning calorimetry, X-ray diffraction, dynamic light scattering, and Fourier transform infrared spectroscopy. The physicochemical results showed that the preparations were monodisperse (PDI 0.062–0.248) in water with an average size from 140.5 to 165.6 nm and a zeta potential of −47.3 to −53.3 mV. Dissolution studies in vitro showed a slower release of PEITC (>90%, 6 h) in comparison to that of SFN (3 h). Here, we are the first to report the antiarthritic activity of CLF of NAR + SFN and NAR + PEITC in the Freund’s complete adjuvant (FCA)-induced arthritic model. At an intraperitoneal dose (375 + 375 μg/mL) for 3 weeks, the NAR + PEITC liposome significantly improves both % paw edema and arthritic score compared to their free drug combinations in FCA rats. Most importantly, hematological and biochemical results showed improved anemic conditions with significant changes in the SGOT, SGPT, and ALP levels. The ELISA results showed similar trends of increased cytokine (IL-10) and decreased inflammation markers (TNF-α, IL-6, IFN-γ). Histological evaluations showing reduction in cell infiltration, pannus formation, and bone and cartilage destruction further confirm and validate the antiarthritic activity of the CLF. This comprehensive study reveals the effectiveness of combination liposomes of poorly soluble anti-inflammatory molecules (NAR, SFN, PEITC) in the treatment of arthritis.

A visible light induced palladium-catalyzed fluoroalkylation method was developed. The Heck-type alkyl coupling reaction enables the introduction of trifluoroethyl, difluoroethyl and other fluoroalkyl fragment into styrenes under mild reaction conditions without the use of additional photosensitizers and ensures access to fluoroalkylated olefins on a broad scale.

Spiroindenoquinoxaline pyrrolizidines (SIQPs)-7-nitro-2'-phenyl-5',6',7',7a'-tetrahydrospiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine]-1',1'(2'H)-dicarbonitrile (SIQP I), 2'-(4-cyanophenyl)-7-nitro-5',6',7',7a'-tetrahydrospiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine]-1',1'(2'H)-dicarbonitrile (SIQP II), and 2'-(4-methoxyphenyl)-7-nitro-5',6',7',7a'-tetrahydrospiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine]-1',1'(2'H)-dicarbonitrile (SIQP III)-have been synthesized through a one-pot cascade Knoevenagel condensation reaction in acetonitrile (ACN) with 91, 98, and 87% yields, respectively. Structures are characterized by 1H NMR and 13C NMR spectroscopy, nuclear Overhauser enhancement spectroscopy (NOESY), Fourier transform infrared (FT-IR) and UV-vis spectroscopy, thermogravimetric analysis (TGA), high-resolution mass spectroscopy (HRTEM), fluorescence and Raman spectroscopy, and energy-dispersive analysis by X-ray (EDX) spectroscopy. SIQPs in ACN photocatalyzed methylene blue (MB) but not phenolphthalein (HIn). SIQPs distinguished the quaternary atoms and dipoles of the fluorescent dye (MB) contrary to the quinonoid HIn structure. In sunlight, SIQPs without electricity input acted as a photonic sensor to detect fluorescent dyes in waste effluents of textile, paper, dyes, and other industries. Activation energy (E a), enthalpy (ΔH), entropy (ΔS), and Gibbs free energy (ΔG) calculated from UV-vis absorption spectra show photocatalytic reduction (PCR) activities in the order SIQP II > III > I. The N-atom of pyrrolizidine and -NO2 of nitro-indenoquinoxaline (NIQ) induced the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) electrodynamics to enable the SIQPs to catalyze biochemical activities.

Low-grade dark maple syrup was successfully discolored on activated carbon. Several experimental parameters were tested, namely, the mixing time (20, 40, and 60 min), concentration of the activated carbon (0.1, 0.3, and 0.5 g/100 mL), type of activated carbon (I, II, and III), activated carbon particle size (25, 50, and 75 μm), stirring speed (200, 400, and 600 rpm), and temperature (40, 60, and 80 °C). The obtained results showed that the discoloration is optimal by applying the following parameters: a mixing time of 40 min with a type III activated carbon at a concentration of 0.3 g/100 mL. These parameters yielded a light transmittance at 560 nm of 83.70 ± 0.21%, which ranks the syrup in the extra clear class according to the Canadian classification. The results showed that among the tested carbons, the adsorption on the type III carbon followed the Langmuir, Freundlich, and Langmuir-Freundlich adsorption isotherms. Regarding the effect of the particle size, the obtained results showed that a mean size of 25 μm combined with a stirring speed of 200 rpm and working temperature of 80 °C was the most effective one. The optimized conditions showed a good adequacy with the Langmuir and Freundlich models. The discoloration process by using the type III activated carbon followed the pseudo-second-order kinetics.

This study was conducted to investigate the effects of short administration with the combination (GMF) of galactooligosaccharides (GOS), milk fat globule membrane (MFGM), and fructooligosaccharides (FOS) on microbiota, intestinal barriers, and growth performance of neonatal piglets. Sixteen newborn piglets were divided into two groups: GMF group and CON group; GMF solution (5 mL) and saline (5 mL) were, respectively, administered to piglets in the GMF group and CON group once a day during the first week after birth. The results showed that GMF administration improved the growth performance of neonatal piglets on day 8 and day 21, coupled with the enriched genus Lactobacillus on day 8 and the increased genera norank_f__Muribaculaceae, Christensenellaceae_R-7_group, Enterococcus, and Romboutsia on day 21. Additionally, GMF administration increased luminal acetate and propionate levels, upregulated the gene expressions of intestinal tight junctions (Occludin, Claudins, and ZO-1), mucins (Mucin-1, Mucin-2, Mucin-4, and Mucin-20), and cytokines (TNF-α, IL-1β, and IL-22) while decreased the plasma diamine oxidase (DAO) level on day 21. The correlation analysis showed a positive relationship between the colonized beneficial microbiota and the modified intestinal barrier genes. In conclusion, the first week administration of GMF facilitated the colonization of beneficial bacteria, promoted intestinal development by enhancing microbiota-associated intestinal barrier functions, and improved the growth performance of the piglets during the whole neonatal period. Our findings provide guidelines for combined prebiotics application in modulating the microbial colonization and intestinal development of the neonates.

Skin defects, soft tissue damage, and fractures often occur simultaneously in severe trauma. Under current medical technology, fractures can be quickly fixed by internal or external repair techniques, and early functional exercises can be performed. However, skin defects heal over a long time and can even be difficult to heal. Functional exercise may cause cutting of fresh granulation to break and impair wound healing. Functional exercise and wound healing seem to contradict each other. In this study, an alginate hydrogel was developed. With self-healing characteristics, the hydrogel tightly adhered to the wound and could self-heal breaks in the gel caused by functional exercises. These characteristics enable this hydrogel to be used in complex clinical situations to solve sports rehabilitation and skin defect repair problems. In addition, this hydrogel can slowly release strontium ions, promote angiogenesis and collagen deposition in the wound, and quickly heal the wound.

Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is a deubiquitylating enzyme which is proposed as a potential therapeutic target in neurodegeneration, cancer, and liver and lung fibrosis. Herein we report the discovery of the most potent and selective UCHL1 probe (IMP-1710) to date based on a covalent inhibitor scaffold and apply this probe to identify and quantify target proteins in intact human cells. IMP-1710 stereoselectively labels the catalytic cysteine of UCHL1 at low nanomolar concentration in cells. We further demonstrate that potent and selective UCHL1 inhibitors block pro-fibrotic responses in a cellular model of idiopathic pulmonary fibrosis, supporting the potential of UCHL1 as a potential therapeutic target in fibrotic diseases.

How do local reactivity descriptors, such as the Fukui function and the local spin density distribution, shape the potential energy surface (PES) associated with chemical reactions and thus govern reactivity trends and regioselective preferences? This is the question that is addressed here through a qualitative valence bond (VB) analysis. We demonstrate that common density functional theory (DFT)-based local reactivity descriptors can essentially be regarded-in one way or another-as indirect measures of delocalization, i.e., resonance stabilization, of the reactants within VB theory. The inherent connection between (spatial) delocalization and (energetic) resonance stabilization embedded in VB theory provides a natural and elegant framework for analyzing and comprehending the impact of individual local reactivity descriptors on the global PES. Our analysis provides new insights into the role played by local reactivity descriptors and illustrates under which conditions they can sometimes fail to predict reactivity trends and regioselective preferences, e.g., in the case of ambident reactivity. This treatment constitutes a first step toward a unification of VB theory and conceptual DFT.

Perovskite solar cells offer remarkable performance, but further advances will require deeper understanding and control of the materials and processing. Here, we fabricate the first single crystal nanorods of intermediate phase (MAI-PbI2-DMSO), allowing us to directly observe the phase evolution while annealing in situ in a high-vacuum transmission electron microscope, which lets up separate thermal effects from other environmental conditions such as oxygen and moisture. We attain the first full determination of the crystal structures and orientations of the intermediate phase, evolving perovskite, precipitating PbI2, and e-beam induced PbI2 during phase conversion and decomposition. Surprisingly, the perovskite decomposition to PbI2 is reversible upon cooling, critical for long-term device endurance due to the formation of MAI-rich MAPbI3 and PbI2 upon heating. Quantitative measurements with a thermodynamic model suggest the decomposition is entropically driven. The single crystal MAPbI3 nanorods obtained via thermal cycling exhibit excellent mobility and trap density, with full reversibility up to 100 °C (above the maximum temperature for solar cell operation) under high vacuum, offering unique potential for high-performance flexible solar cells., In situ microscopy identifies when MAPbI3 is protected from extrinsic reactants, perovskite decomposition to PbI2 occurs at temperatures too low for MAI evaporation, and it is reversible upon cooling.

The kinetics of the hydration reaction on trans-[Pt(NH3)2(pyrX)Cl]+ (pyr = pyridine) complexes (X = OH–, Cl–, F–, Br–, NO2–, NH2, SH–, CH3, C≡CH, and DMA) was studied by density functional theory calculations in the gas phase and in water solution described by the implicit polarizable continuum model method. All possible positions ortho, meta, and para of the substituent X in the pyridine ring were considered. The substitution of the pyr ligand by electron-donating X’s led to the strengthening of the Pt–N1(pyrX) (Pt–NpyrX) bond and the weakening of the trans Pt–Cl or Pt–Ow bonds. The electron-withdrawing X’s have exactly the opposite effect. The strengths of these bonds can be predicted from the basicity of sigma electrons on the NpyrX atom determined on the isolated pyrX ligand. As the pyrX ring was oriented perpendicularly with respect to the plane of the complex, the nature of the X···Cl electrostatic interaction was the decisive factor for the transition-state (TS) stabilization which resulted in the highest selectivity of ortho-substituted systems with respect to the reaction rate. Because of a smaller size of X’s, the steric effects influenced less importantly the values of activation Gibbs energies ΔG⧧ but caused geometry changes such as the elongation of the Pt–NpyrX bonds. Substitution in the meta position led to the highest ΔG⧧ values for most of the X’s. The changes of ΔG⧧ because of electronic effects were the same in the gas phase and the water solvent. However, as the water solvent dampened electrostatic interactions, 2200 and 150 times differences in the reaction rate were observed between the most and the least reactive mono-substituted complexes in the gas phase and the water solvent, respectively. An additional NO2 substitution of the pyrNO2 ligand further decelerated the rate of the hydration reaction, but on the other hand, the poly-NH2 complexes were no more reactive than the fastest o-NH2 system. In the gas phase, the poly-X complexes showed the additivity of the substituent effects with respect to the Pt–ligand bond strengths and the ligand charges.

The catalytic esterification of free fatty acids is an important reaction pathway for chemical synthesis and biodiesel production, wherein efficient heterogeneous catalysts are sought to replace mineral acids. Herein, the esterification of oleic acid together with some familiar fatty acids is demonstrated with methanol over a heterogeneous heteropolyacid-functionalized zeolite imidazolate framework [H6–nP2W18O62n–/ZIF(HnHis.)+n]. This new heterogeneous catalyst (named as HPA/ZIF(His.) throughout the text) with an average particle size of 80 nm was prepared via condensation of histamine with zinc chloride and characterized by means of Fourier transform infrared (FT-IR), X-ray diffraction (XRD), UV–vis, energy-dispersive X-ray spectrometry, Brunauer–Emmett–Teller, thermogravimetric analysis (TGA), inductively coupled plasma - optical emission spectrometry (ICP-OES), and scanning electron microscopy. According to the performed characterizations, an HPA loading of 40.5 wt % is obtained for HPA/ZIF(His.) from ICP-OES analysis. Moreover, a typical type-IV isotherm with similar adsorption–desorption properties as seen for ZIF-8 is attained. In addition, TGA measurement confirms less stability of HPA/ZIF(His.) compared to that of pure ZIF(His.). The catalytic performance of the nanomaterial is evaluated with respect to temperature, catalyst loading, and methanol/oleic acid ratio and leads to a high yield of methyl ester (>90%) under reflux for 4 h. The preliminary kinetic studies confirm a pseudo-first-order kinetic model for the esterification of oleic acid. To explore the scope of the HPA/ZIF(His.) catalyst in methyl ester production, other free fatty acids with various chain lengths are also successfully tested. Although the nanocatalyst loses a part of its activity during reuse, however, it is stable over at least four recycles as confirmed by XRD and FT-IR. Eventually, the response surface methodology (RSM) is used as a statistical modeling approach to get the best-optimized reaction conditions compared to the performed single-variable benchmarking experiments. Therefore, the central composite design (CCD) and RSM attained a platform to determine the relationship among the reaction time, acid/methanol molar ratio, and catalyst dosage.

Forest is one of nature’s most generous gifts to human beings, providing materials and shelters for all living beings with over 30% global land coverage. Apart from being sustainable, biodegradable, and renewable, wood is also extremely fascinating from the application aspect, with numerous advantages including hierarchical and macroporous structure, excellent mechanical performance, and versatile chemistry. The macroporous structure of wood is comprised of numerous long, partially aligned channels along the growth direction. This structure is suitable for a range of emerging applications, especially as a separation/membrane material. In this research, the potentiality of Gingko biloba (Gb) wood in the remediation of wastewater, contaminated with methylene blue (MB), a dye found in the industrial waters, was investigated. We report a macroporous, three-dimensional (3D) Gb-wood membrane decorated with palladium nanoparticles (Pd NPs) for efficient wastewater treatment. The efficiency of the Pd NPs/Gb-wood membrane to remove MB from a flowing aqueous solution was demonstrated. The wastewater treatment rate of the 3D Pd NPs/Gb-wood membrane can reach 0.5 L/min, with a high MB removal efficiency (>99.9%). The 3D Gb-wood macroporous membrane with partially aligned channels exhibits promising results for water treatment and is applicable for an even wider range of separation applications. In addition, the benefit of this 3D-wood membrane system for wastewater treatment was evaluated against the potential impacts on the environment and human health by employing the life-cycle assessment (LCA) approach. The LCA was carried out using the Gabi-education version with the gate-to-grave approach, including industrial wastewater, 3D-wood membrane, and electricity consumption using CML (Centrum VoorMilieukunde Leiden). From the LCA, it can be observed that wastewater filtration using this membrane exhibited a better environmental footprint due to the improved performance of the membrane in treating a higher volume of the permeate. Therefore, this filtration system had outweighed the additional environmental impact of the wastewater treatment process. The energy demand was identified as the main environmental hotspot in the LCA analysis. The analysis revealed that the energy source for electricity generation had a significant influence on the overall sustainability of this system. Additionally, the wood itself, a naturally abundant and eco-friendly material, presented zero environmental hazard to the environment during the filtration process. The experimental and environmental impact results indicate that Gb-wood can be employed as a natural and eco-friendly adsorbent material for the removal of waste from aqueous solutions.

In this study, we report a green and economical hydrothermal synthesis of fluorescent-nitrogen-doped carbon quantum dots (NCQDs) using citrus lemon as a carbon source. The prepared NCQDs possess high water solubility, high ionic stability, resistance to photobleaching, and bright blue color under ultraviolet radiation with a high quantum yield (∼31%). High-resolution transmission electron microscopy (HRTEM) results show that the prepared NCQDs have a narrow size distribution (1–6 nm) with an average particle size of 3 nm. The mercury ion (Hg2+) sensing efficiency of the NCQDs was studied, and the result indicated that the material has high sensitivity, high precision, and good selectivity for Hg2+. The limit of detection (LOD) is 5.3 nM and the limit of quantification (LOQ) is 18.3 nM at a 99% confidence level. The cytotoxicity was evaluated using MCF7 cells, and the cell viabilities were determined to be greater than 88% upon the addition of NCQDs over a wide concentration range from 0 to 2 mg/mL. Based on the low cytotoxicity, good biocompatibility, and other revealed interesting merits, we also applied the prepared NCQDs as an effective fluorescent probe for multicolor live cell imaging.

The use of peptidomimetic scaffolds is a promising strategy for the inhibition of protein–protein interactions (PPIs). Herein, we demonstrate that sulfono-γ-AApeptides can be rationally designed to mimic the p53 α-helix and inhibit p53–MDM2 PPIs. The best inhibitor, with Kd and IC50 values of 26 nM and 0.891 μM toward MDM2, respectively, is among the most potent unnatural peptidomimetic inhibitors disrupting the p53–MDM2/MDMX interaction. Using fluorescence polarization assays, circular dichroism, nuclear magnetic resonance spectroscopy, and computational simulations, we demonstrate that sulfono-γ-AApeptides adopt helical structures resembling p53 and competitively inhibit the p53–MDM2 interaction by binding to the hydrophobic cleft of MDM2. Intriguingly, the stapled sulfono-γ-AApeptides showed promising cellular activity by enhancing p53 transcriptional activity and inducing expression of MDM2 and p21. Moreover, sulfono-γ-AApeptides exhibited remarkable resistance to proteolysis, augmenting their biological potential. Our results suggest that sulfono-γ-AApeptides are a new class of unnatural helical foldamers that disrupt PPIs.

Polymer electrolyte membranes in which the hydrophilic and hydrophobic domains phase separate exhibit improved properties and stability. Such a phase separation of hydrophilic and hydrophobic domains can be achieved by polymerizing a 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide-bisphenol A (DOPO-BPA) and 1,4-bis(4-fluorobenzoyl)benzene (1,4-FBB) monomer. In this work, sulfonated polymer membranes with various degrees of sulfonation (DS) were prepared and their physicochemical and electrochemical properties were studied. In addition, the effect of molecular structure on the durability of the copolymers was investigated. The sulfonated copolymers were characterized by Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. Then, sulfonated membranes were prepared using these copolymers by the solvent casting method, and their morphologies were investigated by atomic force microscopy. The effect of DS on the thermal, mechanical, and oxidative stabilities, water uptake behavior, and ion-exchange capacity of the membranes was determined. The results showed that compared with the commercially available Nafion 212 polymer electrolyte membrane, the electrolyte membrane based on DOPO-BPA and 1,4-FBB exhibited a lower water uptake and excellent dimensional stability despite having a relatively high ion-exchange capacity. The low water uptake is an important characteristic that ensures the stability of the polymer electrolyte membrane in fuel cell applications.

Rhodamine dyes exist in equilibrium between a fluorescent zwitterion and a nonfluorescent lactone. Tuning this equilibrium toward the nonfluorescent lactone form can improve cell-permeability and allow creation of “fluorogenic” compounds—ligands that shift to the fluorescent zwitterion upon binding a biomolecular target. An archetype fluorogenic dye is the far-red tetramethyl-Si-rhodamine (SiR), which has been used to create exceptionally useful labels for advanced microscopy. Here, we develop a quantitative framework for the development of new fluorogenic dyes, determining that the lactone–zwitterion equilibrium constant (KL–Z) is sufficient to predict fluorogenicity. This rubric emerged from our analysis of known fluorophores and yielded new fluorescent and fluorogenic labels with improved performance in cellular imaging experiments. We then designed a novel fluorophore—Janelia Fluor 526 (JF526)—with SiR-like properties but shorter fluorescence excitation and emission wavelengths. JF526 is a versatile scaffold for fluorogenic probes including ligands for self-labeling tags, stains for endogenous structures, and spontaneously blinking labels for super-resolution immunofluorescence. JF526 constitutes a new label for advanced microscopy experiments, and our quantitative framework will enable the rational design of other fluorogenic probes for bioimaging., We developed a general rubric for creating fluorogenic stains, resulting in the novel fluorophore JF526. This dye can be used in numerous imaging modalities including super-resolution microscopy.

Urea removal from dialysate is the major obstacle in realization of a miniature dialysis device, based on continuous dialysate regeneration in a closed loop, used for the treatment of patients suffering from end-stage kidney disease. For the development of a polymeric urea sorbent, capable of removing urea from dialysate with high binding capacities and fast reaction kinetics, a systematic kinetic study was performed on the reactivity of urea with a library of low-molecular-weight carbonyl compounds in phosphate-buffered saline (pH 7.4) at 323 K. It was found that dialdehydes do not react with urea under these conditions but need to be activated under acidic conditions and require aldehyde groups in close proximity to each other to allow a reaction with urea. Among the 31 (hydrated) carbonyl compounds tested, triformylmethane, ninhydrin, and phenylglyoxaldehyde were the most reactive ones with urea. This is attributed to the low dehydration energies of these compounds, as calculated by Gibbs free energy differences between the hydrated and dehydrated carbonyl compounds, which are favorable for the reaction with urea. Therefore, future urea sorbents should contain such functional groups at the highest possible density.

Correction published on October 23, 2020 https://doi.org/10.1021/acsomega.0c04910, The potentially tridentate ligand bis[(1-methyl-2-benzimidazolyl)ethyl]amine (2BB) was employed to prepare copper complexes [(2BB)CuI]OTf and [(2BB)CuII(H2O)2](OTf)2 as bioinspired models of lytic polysaccharide copper-dependent monooxygenase (LPMO) enzymes. Solid-state characterization of [(2BB)CuI]OTf revealed a Cu(I) center with a T-shaped coordination environment and metric parameters in the range of those observed in reduced LPMOs. Solution characterization of [(2BB)CuII(H2O)2](OTf)2 indicates that [(2BB)CuII(H2O)2]2+ is the main species from pH 4 to 7.5; above pH 7.5, the hydroxo-bridged species [{(2BB)CuII(H2O)x}2(μ-OH)2]2+ is also present, on the basis of cyclic voltammetry and mass spectrometry. These observations imply that deprotonation of the central amine of Cu(II)-coordinated 2BB is precluded, and by extension, amine deprotonation in the histidine brace of LPMOs appears unlikely at neutral pH. The complexes [(2BB)CuI]OTf and [(2BB)CuII(H2O)2](OTf)2 act as precursors for the oxidative degradation of cellobiose as a cellulose model substrate. Spectroscopic and reactivity studies indicate that a dicopper(II) side-on peroxide complex generated from [(2BB)CuI]OTf/O2 or [(2BB)CuII(H2O)2](OTf)2/H2O2/NEt3 oxidizes cellobiose both in acetonitrile and aqueous phosphate buffer solutions, as evidenced from product analysis by high-performance liquid chromatography-mass spectrometry. The mixture of [(2BB)CuII(H2O)2](OTf)2/H2O2/NEt3 results in more extensive cellobiose degradation. Likewise, the use of both [(2BB)CuI]OTf and [(2BB)CuII(H2O)2](OTf)2 with KO2 afforded cellobiose oxidation products. In all cases, a common Cu(II) complex formulated as [(2BB)CuII(OH)(H2O)]+ was detected by mass spectrometry as the final form of the complex.

We argue that for situations involving spatially varying linear transport coefficients (diffusivities, thermal conductivities, and viscosities), the original Fick's, Fourier's, and Newton's law equations should be modified to place the diffusivity, thermal conductivity, and viscosity inside the derivative operator, that is, in one-dimensional rectilinear situations, , , and . We present simple derivations of these formulas in which diffusive mass transfer, conductive heat transfer, and molecular momentum transfer processes are described using lattice random walk models. We also present simple examples demonstrating how these modifications affect calculations.

Native liquid extraction surface analysis (LESA) mass spectrometry allows direct analysis of folded proteins and protein complexes from biological substrates, such as dried blood spots and thin tissue sections, by use of native-like extraction/ionization solvents. Previously, we have demonstrated native LESA mass spectrometry of folded proteins up to 16 kDa as well as the 64 kDa hemoglobin tetramer, from mouse tissues. With denaturing LESA solvents, the highest mass protein detected in tissue to date is ∼37 kDa. Here, we demonstrate native LESA mass spectrometry by use of a Q Exactive UHMR Hybrid Quadrupole-Orbitrap (QE-UHMR) mass spectrometer, pushing the upper mass limit of proteins detected in tissue to >70 kDa. Moreover, a protein trimer of 42 kDa was detected and its stoichiometry confirmed by higher energy collision dissociation (HCD). The benefits of inclusion of detergents in the LESA sampling solvent are also demonstrated.

Worldwide outbreaks of infectious diseases necessitate the development of rapid and accurate diagnostic methods. Colorimetric assays are a representative tool to simply identify the target molecules in specimens through color changes of an indicator (e.g., nanosized metallic particle, and dye molecules). The detection method is used to confirm the presence of biomarkers visually and measure absorbance of the colored compounds at a specific wavelength. In this study, we propose a colorimetric assay based on an extended form of double-stranded DNA (dsDNA) self-assembly shielded gold nanoparticles (AuNPs) under positive electrolyte (e.g., 0.1 M MgCl2) for detection of Middle East respiratory syndrome coronavirus (MERS-CoV). This platform is able to verify the existence of viral molecules through a localized surface plasmon resonance (LSPR) shift and color changes of AuNPs in the UV-vis wavelength range. We designed a pair of thiol-modified probes at either the 5' end or 3' end to organize complementary base pairs with upstream of the E protein gene (upE) and open reading frames (ORF) 1a on MERS-CoV. The dsDNA of the target and probes forms a disulfide-induced long self-assembled complex, which protects AuNPs from salt-induced aggregation and transition of optical properties. This colorimetric assay could discriminate down to 1 pmol/μL of 30 bp MERS-CoV and further be adapted for convenient on-site detection of other infectious diseases, especially in resource-limited settings.

We investigated an ss-DNA sequence that can stabilize a red- and a green-emissive silver nanocluster (DNA-AgNC). These two emitters can convert between each other in a reversible way. The change from red- to green-emitting DNA-AgNCs can be triggered by the addition of H2O2, while the opposite conversion can be achieved by the addition of NaBH4. Besides demonstrating the switching between red- and green-emissive DNA-AgNCs and determining the recoverability, we fully characterized the photophysical properties, such as steady-state emission, quantum yield, fluorescence lifetime, and anisotropy of the two emissive species. Understanding the mechanism behind the remarkable conversion between the two emitters could lead to the development of a new range of DNA-AgNC-based ratiometric sensors.

Amylose forms supramolecular inclusion complexes with polymeric guests in the phosphorylase-catalyzed enzymatic polymerization field, so-called “vine-twining polymerization”. However, such inclusion complexes have not exhibited specific properties and processability as functional supramolecular materials. In this study, we found that amylosic inclusion complexes, which were obtained by vine-twining polymerization using a designed guest polymer, that is, an amphiphilic triblock copolymer poly(2-methyl-2-oxazoline-block-tetrahydrofuran-block-2-methyl-2-oxazoline), exhibited gel and film formation properties. The characterization results of the products suggested that enzymatically elongated amylose chains complexed with the polytetrahydrofuran block in the triblock copolymer. Accordingly, the outer poly(2-methyl-2-oxazoline) blocks constructed hydrophilic spaces among the inclusion complex segments. Furthermore, the presence of such outer blocks affected the lower regularity of crystalline alignment among the inclusion complex segments in the products. Such higher-order structures probably induced the formation of supramolecular soft materials, such as gels and films.

Herein, a magnetically separable reduced graphene oxide (rGO)-supported CoFe2O4–TiO2 photocatalyst was developed by a simple ultrasound-assisted wet impregnation method for efficient photocatalytic H2 production. Integration of CoFe2O4 with TiO2 induced the formation of Ti3+ sites that remarkably reduced the optical band gap of TiO2 to 2.80 eV from 3.20 eV. Moreover, the addition of rGO improved the charge carrier separation by forming Ti–C bonds. Importantly, the CoFe2O4–TiO2/rGO photocatalyst demonstrated significantly enhanced photocatalytic H2 production compared to that from its individual counterparts such as TiO2 and CoFe2O4–TiO2, respectably. A maximum H2 production rate of 76 559 μmol g–1 h–1 was achieved with a 20 wt % CoFe2O4- and 1 wt % rGO-loaded TiO2 photocatalyst, which was approximately 14-fold enhancement when compared with the bare TiO2. An apparent quantum yield of 12.97% at 400 nm was observed for the CoFe2O4–TiO2/rGO photocatalyst under optimized reaction conditions. This remarkable enhancement can be attributed to synergistically improved charge carrier separation through Ti3+ sites and rGO support, viz., Ti–C bonds. The recyclability of the photocatalyst was ascertained over four consecutive cycles, indicating the stability of the photocatalyst. In addition, it is worth mentioning that the photocatalyst could be easily separated after the reaction using a simple magnet. Thus, we believe that this study may open a new way to prepare low-cost, noble-metal-free magnetic materials with TiO2 for sustainable photocatalytic H2 production.

As an important method to effectively improve energy efficiency, the study of thermal energy storage is particularly important. In this study, six types of clay mineral-based form-stable phase-change materials (FSPCMs) were prepared by the vacuum adsorption method. The adsorption capacity of vermiculite and diatomite was satisfactory, and sepiolite showed the worst adsorption capacity. Clay minerals can delay the thermal decomposition rate of capric-palmitic acid (CA-PA), and the specific surface area and pore capacity of clay minerals all decrease dramatically after the clay minerals have absorbed CA-PA. FSPCMs exhibited a higher heat storage and release efficiency and reflects a certain temperature control performance. In addition, only physical adsorption between the CA-PA and the clay material occurred, and no chemical reaction occurred. Finally, FSPCMs still have high latent heat of phase transition, and they can be used for low-temperature thermal energy storage.

The preparation and classification of nanocellulose are briefly introduced, and the modification of nanocellulose and the application of modified nanocellulose in oilfield chemistry are reviewed. The principles and methods of surface modification, including surface adsorption, oxidation, acetylation, silanization, etherification, and polymer grafting, are summarized. Meanwhile, this paper focuses on the application of nanocellulose research progress in drilling fluid, enhanced oil recovery, and oilfield sewage treatment. In addition, the application issues and natural advantages of nanocellulose are analyzed, and suggestions and ideas on how to expand its application are put forward. Finally, the development and potential application of nanocellulose in oilfield chemistry are proposed.

Aerosols and droplets from expiratory events play an integral role in transmitting pathogens such as SARS-CoV-2 from an infected individual to a susceptible host. However, there remain significant uncertainties in our understanding of the aerosol droplet microphysics occurring during drying and sedimentation and the effect on the sedimentation outcomes. Here, we apply a new treatment for the microphysical behavior of respiratory fluid droplets to a droplet evaporation/sedimentation model and assess the impact on sedimentation distance, time scale, and particle phase. Above a 100 μm initial diameter, the sedimentation outcome for a respiratory droplet is insensitive to composition and ambient conditions. Below 100 μm, and particularly below 80 μm, the increased settling time allows the exact nature of the evaporation process to play a significant role in influencing the sedimentation outcome. For this size range, an incorrect treatment of the droplet composition, or imprecise use of RH or temperature, can lead to large discrepancies in sedimentation distance (with representative values >1 m, >2 m, and >2 m, respectively). Additionally, a respiratory droplet is likely to undergo a phase change prior to sedimenting if initially, Accurate, experimentally derived microphysical treatments of respiratory fluid droplets enable the robust modeling of sedimentation outcomes.

Metallo-β-lactamases (MBLs) can efficiently catalyze the hydrolysis of all classes of β-lactam antibiotics except monobactams. While serine-β-lactamase (SBL) inhibitors (e.g., clavulanic acid, avibactam) are established for clinical use, no such MBL inhibitors are available. We report on the synthesis and mechanism of inhibition of N-sulfamoylpyrrole-2-carboxylates (NSPCs) which are potent inhibitors of clinically relevant B1 subclass MBLs, including NDM-1. Crystallography reveals that the N-sulfamoyl NH2 group displaces the dizinc bridging hydroxide/water of the B1 MBLs. Comparison of crystal structures of an NSPC and taniborbactam (VRNX-5133), presently in Phase III clinical trials, shows similar binding modes for the NSPC and the cyclic boronate ring systems. The presence of an NSPC restores meropenem efficacy in clinically derived E. coli and K. pneumoniae blaNDM-1. The results support the potential of NSPCs and related compounds as efficient MBL inhibitors, though further optimization is required for their clinical development.

Herein, we present an undirected

The Edmond-Ogston model for phase separation in binary polymer mixtures is based on a truncated virial expansion of the Helmholtz free energy up to the second-order terms in the concentration of the polymers. The second virial coefficients (

Rare diseases impact hundreds of millions of individuals worldwide. However, few therapies exist to treat the rare disease population because financial resources are limited, the number of patients affected is low, bioactivity data is often nonexistent, and very few animal models exist to support preclinical development efforts. Sialidosis is an ultrarare lysosomal storage disorder in which mutations in the NEU1 gene result in the deficiency of the lysosomal enzyme sialidase-1. This enzyme catalyzes the removal of sialic acid moieties from glycoproteins and glycolipids. Therefore, the defective or deficient protein leads to the buildup of sialylated glycoproteins as well as several characteristic symptoms of sialidosis including visual impairment, ataxia, hepatomegaly, dysostosis multiplex, and developmental delay. In this study, we used a bibliometric tool to generate links between lysosomal storage disease (LSD) targets and existing bioactivity data that could be curated in order to build machine learning models and screen compounds in silico. We focused on sialidase as an example, and we used the data curated from the literature to build a Bayesian model which was then used to score compound libraries and rank these molecules for in vitro testing. Two compounds were identified from in vitro testing using microscale thermophoresis, namely sulfameter (K d 2.15 ± 1.02 μM) and mexenone (K d 8.88 ± 4.02 μM), which validated our approach to identifying new molecules binding to this protein, which could represent possible drug candidates that can be evaluated further as potential chaperones for this ultrarare lysosomal disease for which there is currently no treatment. Combining bibliometric and machine learning approaches has the ability to assist in curating small molecule data and model building, respectively, for rare disease drug discovery. This approach also has the capability to identify new compounds that are potential drug candidates.

Semiconducting polymers are versatile materials for solar energy conversion and have gained popularity as photocatalysts for sunlight-driven hydrogen production. Organic polymers often contain residual metal impurities such as palladium (Pd) clusters that are formed during the polymerization reaction, and there is increasing evidence for a catalytic role of such metal clusters in polymer photocatalysts. Using transient optical spectroscopies on nanoparticles of F8BT, P3HT, and the dibenzo[b,d]thiophene sulfone homopolymer, P10, we demonstrate how differences in the timescale of electron transfer to Pd clusters translate into hydrogen evolution activity optima at extremely different residual Pd concentrations. For F8BT nanoparticles with common Pd concentrations of >1000 ppm (>0.1 wt. %), we find that residual Pd clusters quench photogenerated excitons via energy and electron transfer on the fs – ns timescale, thus outcompeting reductive quenching via the electron donor diethylamine in the solution phase. We spectroscopically identify reduced Pd clusters in our F8BT nanoparticles from the µs timescale onwards and show that the predominant location of long-lived electrons gradually shifts to the F8BT polymer when the Pd content is lowered. However, a low yield of long-lived electrons limits the hydrogen evolution activity of F8BT. P10, on the other hand, exhibits a substantially higher hydrogen evolution activity, which we demonstrate results from higher yields of long-lived electrons compared to F8BT due to more efficient reductive quenching. Surprisingly, and despite the higher performance of P10, long-lived electrons reside on the P10 polymer rather than on the Pd clusters in P10 particles, even at very high Pd concentrations of 27,000 ppm (2.7 wt. %). We show that these long-lived electrons in P10 react orders of magnitude slower at lower Pd levels, which suggests that their transfer to Pd sites constitutes a kinetic bottleneck and thus reveals a direction towards further improvements for this already very performant material. In contrast, long-lived electrons in F8BT already reside on Pd clusters before the typical timescale of hydrogen evolution. This comparison illustrates that P10 exhibits efficient reductive quenching but slow electron transfer to residual Pd clusters, whereas the opposite is the case for F8BT. We discuss possible reasons for this pronounced difference in the predominant location of long-lived electrons in F8BT and P10. Our results suggest that the development of even more efficient polymer photocatalysts should target materials that combine both rapid reductive quenching and rapid charge transfer to a metal-based co-catalyst.

Automotive polymer electrolyte membrane fuel cell systems are attracting much attention, driven by the requirements of low automotive exhaust emissions and energy consumption. A polymer electrolyte membrane fuel cell system provides opportunities for the developments in different types of air compressors. This paper proposed an opposed rotary piston compressor, which had the merits of more compact structures, less movement components, and a high pressure ratio, meeting the requirements of polymer electrolyte membrane fuel cell systems. Preliminary performance evaluations of the opposed rotary piston compressor were conducted under various scenarios. This will make a foundation for optimizations of outlet pipe layouts of the compressor. A three-dimensional numerical simulation approach was used; further, in-cylinder pressure evolutions, fluid mass flow rates, and P–V diagrams were analyzed. It indicated that the cyclic period of the opposed rotary piston compressor was half of reciprocating piston compressors. The specific mass flow rate of the compressor is in the range of 0.094–0.113 kg·(s·L)−1 for the given scenarios. Outlet ports 1 and 2 dominated the mass flow in the discharge process under scenarios 1, 3, and 4. In-cylinder pressure profiles show multipeaks for all of these scenarios. In-cylinder pressure increased rapidly in the compression process and part of the discharge process, which led to high energy consumption and low adiabatic efficiency. The maximum adiabatic efficiency is approximately 43.96% among the given scenarios.

The global pandemic of SARS-CoV-2, the causative viral pathogen of COVID-19, has driven the biomedical community to action-to uncover and develop antiviral interventions. One potential therapeutic approach currently being evaluated in numerous clinical trials is the agent remdesivir, which has endured a long and winding developmental path. Remdesivir is a nucleotide analogue prodrug that perturbs viral replication, originally evaluated in clinical trials to thwart the Ebola outbreak in 2014. Subsequent evaluation by numerous virology laboratories demonstrated the ability of remdesivir to inhibit coronavirus replication, including SARS-CoV-2. Here, we provide an overview of remdesivir's discovery, mechanism of action, and the current studies exploring its clinical effectiveness.

In this work, an ion imprinted polymer (ReO

The discharge of antibiotics and the potential threat to organisms posed by this have received increasing attention. In this work, flocculent magnesium silicate (FMS) was fabricated by a facile hydrothermal and freeze-drying process, and its adsorption behavior for antibiotic oxytetracycline (OTC) was investigated. FMS presented a sepiolite-type structure and the alkaline solution promoted its hydroxylation. A hierarchical pore structure ranging from micropores to macropores and a high specific surface area of 660 m2/g were exhibited. FMS exhibited a higher adsorption amount in neutral solution than in acidic or alkaline conditions as the physicochemical properties of FMS and OTC were significantly affected by the pH. Adsorption isotherm could be well-described by the Langmuir model, and the calculated saturated adsorption capacity was as high as 265 mg/g. Adsorption kinetics followed the pseudo-second-order kinetic model, and the adsorption rate-controlling step was intraparticle diffusion. Thermodynamic parameters indicated that the adsorption was a spontaneous physicochemical reaction. After five cycles, around 91% of the adsorption performance was still maintained, demonstrating the excellent reusability of FMS. The sepiolite-type FMS fabricated in this work could be applied to remove OTC from wastewater.

An attempt has been made to understand the thermodynamic mechanism study of the low-pressure chemical vapor deposition (LPCVD) process during single-layer graphene (SLG) growth as it is the most debatable part of the CVD process. The intensive studies are being carried out worldwide to enhance the quality of LPCVD-grown graphene up to the level of mechanically exfoliated SLG. The mechanism and processes have been discussed earlier by several research groups during the variation in different parameters. However, the optimization and mechanism involvement due to individual partial pressure-based effects has not been elaborately discussed so far. Hence, we have addressed this issue in detail including thermodynamics of the growth process and tried to establish the effect of the partial pressures of individual gases during the growth of SLG. Also, optical microscopy, Raman spectroscopy, and atomic force microscopy (AFM) have been performed to determine the quality of SLG. Furthermore, nucleation density has also been estimated to understand a plausible mechanism of graphene growth based on partial pressure. Moreover, the field-effect transistor (FET) device has been fabricated to determine the electrical properties of SLG, and the estimated mobility has been found as ∼2595 cm2 V–1 s–1 at n = −2 × 1012 cm–2. Hence, the obtained results trigger that the partial pressure is an important parameter for the growth of SLG and having various potential applications in high-performance graphene FET (GFET) devices.

Förster resonance energy transfer (FRET)-based sensors are a valuable tool to quantify cell biology, yet it remains necessary to identify and prevent potential artifacts in order to exploit their full potential. We show here that artifacts arising from slow donor mCerulean3 maturation can be substantially diminished by constitutive expression in both prokaryotic and eukaryotic cells, which can also be achieved by incorporation of faster-maturing FRET donors. We developed an improved version of the donor mTurquoise2 that matures faster than the parent protein. Our analysis shows that using equal maturing fluorophores in FRET-based sensors or using constitutive low expression conditions helps to reduce maturation-induced artifacts, without the need of additional noise-inducing spectral corrections. In general, we show that monitoring and controlling the maturation of fluorescent proteins in living cells is important and should be addressed in in vivo applications of genetically encoded FRET sensors.

PROteolysis Targeting Chimeras (PROTACs) represent an exciting inhibitory modality with many advantages, including sub-stoichiometric degradation of targets. Their scope, though, is still limited to-date by the requirement for a sufficiently potent target binder. A solution that proved useful in tackling challenging targets is the use of electrophiles to allow irreversible binding to the target. However, such binding will negate the catalytic nature of PROTACs. Reversible covalent PROTACs potentially offer the best of both worlds. They possess the potency and selectivity associated with the formation of the covalent bond, while being able to dissociate and regenerate once the protein target is degraded. Using Bruton’s tyrosine kinase (BTK) as a clinically relevant model system, we show efficient covalent degradation by non-covalent, irreversible covalent and reversible covalent PROTACs, with 85% degradation. Our data suggests that part of the degradation by our irreversible covalent PROTACs is driven by reversible binding prior to covalent bond formation, while the reversible covalent PROTACs drive degradation primarily by covalent engagement. The PROTACs showed enhanced inhibition of B cell activation compared to Ibrutinib, and exhibit potent degradation of BTK in patients-derived primary chronic lymphocytic leukemia cells. The most potent reversible covalent PROTAC, RC-3, exhibited enhanced selectivity towards BTK compared to non-covalent and irreversible covalent PROTACs. These compounds may pave the way for the design of covalent PROTACs for a wide variety of challenging targets.

Plasmon resonances have appeared as a promising method to boost the fluorescence intensity of single emitters. However, because research has focused on the enhancement at low excitation intensity, little is known about plasmon-fluorophore coupling near the point where the dye saturates. Here we study plasmon-enhanced fluorescence at a broad range of excitation intensities up to saturation. We adopt a novel DNA-mediated approach wherein dynamic single-molecule binding provides a controlled particle-fluorophore spacing, and dynamic rebinding circumvents artifacts due to photobleaching. We find that near saturation the maximum photon count rate is enhanced by more than 2 orders of magnitude at the optimal particle-fluorophore spacing, even for a dye with a high intrinsic quantum yield. We compare our results to a numerical model taking into account dye saturation. These experiments provide design rules to maximize the photon output of single emitters, which will open the door to studying fast dynamics in real time using single-molecule fluorescence.

We analyze in depth two widely used definitions (from the theory of conditional probablity amplitudes and from the adiabatic connection formalism) of the exchange-correlation energy density and of the response potential of Kohn-Sham density functional theory. We introduce a local form of the coupling-constant-dependent Hohenberg-Kohn functional, showing that the difference between the two definitions is due to a corresponding local first-order term in the coupling constant, which disappears globally (when integrated over all space), but not locally. We also design an analytic representation for the response potential in the strong-coupling limit of density functional theory for a model single stretched bond.