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A new method for creating various ordered small-scale biologically-based nanorod arrays over a large area through the force-controlled stamping is being discussed. The analysis can be widely used in the fields of material patterning and small-scale fabrication technology.

An iridium photoredox catalyst in combination with phenanthroline-supported palladium catalyst catalyzes decarboxylative alkenylation of tertiary and secondary aliphatic carboxylic acids with vinyl arenes to deliver β-alkylated styrenes with Z-selectivity. A broad scope of aliphatic carboxylic acids, including amino acids, exhibit as amenable substrates, and external oxidant is not required. The reaction proceeds by synergistic utilization of both energy-transfer and electron-transfer reactivity of iridium photoredox catalyst merging with palladium-catalyzed hydride elimination and insertion. [ABSTRACT FROM AUTHOR]

A novel stamping method is developed that applies pressure on the upper surface of the stamp to regulate the dewetting process of the inorganic buffer and the evaporation rate of the solvent in this buffer between the substrate and the surface of the stamp. Multiple sizes and distributions of the inorganic material could be created by using a single stamp combined with analogue patterning through the force-contact control.

Decarboxylative borylation of aryl and alkenyl carboxylic acids with bis(pinacolato)diboron was achieved through N-hydroxyphthalimide esters using tert-butyl isonicotinate as a catalyst under base-free conditions. A variety of aryl carboxylic acids possessing different functional groups and electronic properties can be smoothly converted to aryl boronate esters, including those that are difficult to decarboxylate under transition-metal catalysis, offering a new method enabling use of carboxylic acid as building blocks in organic synthesis. Mechanistic analysis suggests the reaction proceeds through coupling of a transient aryl radical generated by radical decarboxylation with a pyridine-stabilized persistent boryl radical. Activation of redox active esters may proceed via an intramolecular single-electron-transfer (SET) process through a pyridine-diboron-phthalimide adduct and accounts for the base-free reaction conditions. [ABSTRACT FROM AUTHOR]

The photodissociation dynamics of CH3I from 277 to 304 nm is studied with our mini-TOF photofragment translational spectrometer. A single laser beam is used for both photodissociation of CH3I and REMPI detection of iodine. Many resolved peaks in each photofragment translational spectrum reveal the vibrational states of the CH3fragment. There are some extra peaks showing the existence of the hot-band states of CH3I. After careful simulation with consideration of the hot-band effect, the distribution of vibrational states of the CH3fragment is determined. The fraction σ of photofragments produced from the hot-band CH3I varies from 0.07 at 277.38 nm to 0.40 at 304.02 nm in the I* channel and from 0.05 at 277.87 nm to 0.16 at 304.67 nm in the I channel. Eint/Eavlof photofragments from ground-state CH3I remains at about 0.03 in the I* channel for all four wavelengths, but Eint/Eavldecreases from 0.09 at 277.87 nm to 0.06 at 304.67 nm in the I channel. From the ground-state CH3I, the quantum yield Φ(I*) is determined to be 0.59 at 277 nm and 0.05 at 304 nm. The curve-crossing probability Pccfrom the hot-band CH3I is lower than that from the ground-state CH3I. The potential energy at the curve-crossing point is determined to be 32 740 cm−1. [ABSTRACT FROM AUTHOR]

The strong backmixing of the liquid phase which is prevalent in a bubble column should be ascribed to its global circulation which is upward in the central region while downward near the wall on the reactor scale. To suppress the backmixing behavior, interruption of the liquid circulation route should be effective. To verify this presumption, an investigation was conducted with a bubble column 550 cm in height and 50 cm in diameter, which was equipped with four channels of the same size installed at different heights so as to cut the downward motion of the liquid and therefore prevent the global circulation the liquid. It shows that although the radial velocity distribution of the liquid remains parabolic in the short column constituted by two neighbor channels, the velocity profile tends to be flat in the upward direction as the channel is approached. The residence time distribution analysis shows that the backmixing of liquid could be reduced by 60% when four channels 12 cm in diameter were applied. [ABSTRACT FROM AUTHOR]

Heterogeneity of oil reservoirs often leads to unproductive cycling of injected oil recovery chemicals, resulting in the loss of significant quantities of reserves. To maximize recovery efficiency, a blocking agent may be placed deep into high-permeability channels so that the subsequently injected chemicals can be redirected into previously unswept regions. Cr(III)−polyacrylamide gels have been used extensively in field applications as blocking agents for sweep improvement; however, the gelation time of the current state-of-the-art is too short to achieve in-depth placement. This paper describes a novel approach of using polyelectrolyte complex nanoparticles to entrap and control the release Cr(III) to effectively extend gelation time. Self-assembly of polyethylenimine (PEI) and dextran sulfate (DS) resulted in the formation of ∼100−200 nm particles that efficiently entrapped chromium while maintaining colloidal stability in water or gelant. Although the addition of chromium chloride to HPAM typically produced gels in minutes, chromium was efficiently sequestered in nanosuspensions of polyelectrolyte complexes, resulting in a significant delay in gel formation that was dependent on pH, ionic strength, and temperature. The gel formation kinetics of PEI, polyelectrolyte complexes (PECs) of PEI and DS, and PECs loaded with chromium were compared. PEI, a known cross-linker of HPAM, produced a steady increase in gelant viscosity over time. PECs without chromium demonstrated a delayed gel formation compared to PEI but possessed a similar creeping increase in viscosity. In contrast, PECs loaded with chromium typically showed minimal viscosity increase over time followed by an abrupt viscosity increase, resulting in gel formation. This study suggests that PECs offer a flexible nanotechnology platform that may enable novel chemical delivery schemes in the oil and gas industry. [ABSTRACT FROM AUTHOR]

The second-stage rector is the last unit in the purification of pyrolysis gasoline for production of aromatics. The feedstock contains a small amount of olefin and organic sulfur but a large amount of benzene as high as 51 wt %. It is therefore a difficulty to remove sulfur and olefin thoroughly while keeping the aromatics unconverted, since the reaction is normally conducted at 280−330 °C and 2.5−3.0 MPa in the presence of excessive hydrogen. To evaluate the property of a commercial catalyst LY-9802 with Co−Mo−Ni supported over -Al2O3, hydrogenation kinetics of thiophene, olefin, and benzene were measured, and the results show the catalyst is very active for the hydrogenation of thiophene and olefin but is inactive for the saturation of benzene. To simulate the operating behavior of the reactor, one-dimensional heterogeneous model was applied, and it was found that the gas−solid interfacial difference in temperature and concentration is negligible. From the variation of the operating variables, such as the inlet temperature, operation pressure, hydrogen flow rate, and feedstock flow rate. It shows the reactor is operated in a safe and reliable region and could be optimized with some of these variables. [ABSTRACT FROM AUTHOR]

A fixed-bed reactor or a catalyst particle can be considered as a porous media network, which is characterized by the pellet size, void fraction, and connectivity of the network. In a fixed-bed reactor, the percolation threshold was calculated to be 0.13−0.17, while the porosity of a fixed bed is ∼0.38; therefore, there is no percolation problem and a fixed bed can be modeled as a continuum medium. In multiphase flow, the connectivity of the network is much reduced due to the attachment of liquid film on the particles and an analogy was made between a trickle bed and a Bethe tree. It shows from this work that radial velocity profile estimation in a fixed bed could be obtained from transforming the bed space into a tube of a certain equivalent diameter, and the trickling to pulsing flow transition could be explained from its analogy to a Bethe tree. Electrical capacity tomography was employed to measure the dynamic liquid holdup in pulsing flow. Two types of packing have been identified from their different flooding behavior, and a quadralobe extrude was specifically designed to obtain the high flooding velocity. When the catalyst was internally wetted, the reaction rate was found to decrease linearly with the catalyst wetting fraction, nevertheless, and no percolation threshold was encountered, and this strange result was explained from the egg shell-type distribution of Pd beneath the support surface of only 0.4 mm. [ABSTRACT FROM AUTHOR]

A living cell has a crowded environment with a dense distribution of molecules that requires structured organization for its efficient functioning. One component of this structure, the actin cytoskeleton, is essential for providing mechanical support and facilitating many response activities, including the contraction of muscle cells and chemotaxis. Whereas many investigations have provided insight into the mechanical response from either an in vivo or in vitro perspective, a significant gap exists in determining how the living cell response and the polymer physics response are bridged. The understanding of these systems involves studying their components, including the individual cytoskeletal elements versus the higher-order organism organization in a living cell. Here, we leverage this organization in nature by using a chemistry-based approach to mimic the cytoskeleton in an artificial environment composed of spherically distributed lipid bilayers. This construct bears similarities to the cell membrane. To create a structurally regulated environment, we encapsulate G-actin into giant unilamellar vesicles and then polymerize actin filaments within individual liposomes. We visualize these vesicles with epifluorescence microscopy and confocal microscopy. Atomic force microscopy is then used to probe the mechanical properties of these artificial cells. This polymer cytoskeletal network appears to connect with the lipid bilayer and span the internal space within the liposomes in a manner similar to what is observed in living cells. This work will have implications in a variety of fields, including chemistry, polymer physics, structural biology, and engineering mechanics. [ABSTRACT FROM AUTHOR]

An efficient one-pot two-step synthesis of diversified 3-acyl-5-hydroxybenzofurans under microwave irradiation is described. The desired products were synthesized rapidly by adopting the Nenitzescu reaction of enaminones and benzoquinones. This methodology provides us with high proportion of desired products in the crude mixture with short reaction times. These two advantages are especially favorable for generating compound libraries in high-throughput biological screening. [ABSTRACT FROM AUTHOR]

The article demonstrates a printing method that imposes a mechanical force on the upper surface of the stamp to regulate the dewetting process and evaporation rate of the inorganic buffer. The method is used to influence the characteristics of the dewetting process and the polymerization of G-actin in vitro, ultimately providing with the ability to obtain organized filamentous actin-based nanorods in defined patterns. Results of the study are presented and discussed.

A one-step method for synthesizing 3-(Fmoc-amino acid)-3,4-diaminobenzoic acids was used to prepare preloaded diaminobenzoate resin. The coupling of free diaminobenzoic acid and Fmoc-amino acids gave pure products in 40-94% yield without any purification step in addition to precipitation except for histidine. For the proline residue, crude products were collected and used for solid-phase peptide synthesis to give a moderate yield of a pentapeptide. In addition, this method was used to prepare unusual amino acid derivatives, namely, (2-naphthyl) alanine and 6-aminohexanoic acid derivatives, in 50 and 65% yield, respectively., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

This study proposes a vascular endothelial growth factor (VEGF) biosensor for diagnosing various stages of cervical carcinoma. In addition, VEGF concentrations at various stages of cancer therapy are determined and compared to data obtained by computed tomography (CT) and cancer antigen 125 (CA-125). The increase in VEGF concentrations during operations offers useful insight into dosage timing during cancer therapy. This biosensor uses Avastin as the biorecognition element for the potential cancer biomarker VEGF and is based on a n-type polycrystalline silicon nanowire field-effect transistor (poly-SiNW-FET). Magnetic nanoparticles with poly[aniline-co-N-(1-one-butyric acid) aniline]-Fe3O4 (SPAnH-Fe3O4) shell-core structures are used as carriers for Avastin loading and provide rapid purification due to their magnetic properties, which prevent the loss of bioactivity; furthermore, the high surface area of these structures increases the quantity of Avastin immobilized. Average concentrations in human blood for species that interfere with detection specificity are also evaluated. The detection range of the biosensor for serum samples covers the results expected from both healthy individuals and cancer patients.