Notes

Ureteral Avulsion Through Retrograde Intrarenal Surgery: When the Unexpected Comes about.
The presence of the titania metasurface enhances the signal by almost an order of magnitude with respect to the 2D counterpart (simulated as an effective medium approximation) and is attributed to the antenna effect, enhancing the interaction of the confined electromagnetic wave with the sensitive microporous medium. This sol-gel nanocomposite system presents many advantages such as high throughput and low-cost elaboration of elements and a high chemical, mechanical, and thermal resistance, ensuring high stability as a potential gas-sensitive nanocomposite layer for long periods. This work is a case study of improving the sensitivity of sol-gel gas-sensitive materials in optical transduction, which will be exploited in further works to develop artificial noses.Dibenzocycloheptanones (dibenzotropones) were prepared by Brønsted acid mediated intramolecular alkyne-carbonyl metathesis (ACM) reactions. The cyclization precursors are readily available by Sonogashira reaction of 2-bromobenzoyl chloride with terminal alkynes, followed by Suzuki reactions with benzaldehydes. The ACM reactions are highly modular and atom economic and allow for the construction of two regioisomeric series of dibenzotropones.Molecular organizations and charge patterns inside biological nanopores are optimized by evolution to enhance ionic and molecular transport. Inspired by the nuclear pore complex that employs asymmetrically arranged disordered proteins for its gating, we here design an artificial nanopore coated by an asymmetric polyampholyte brush as a model system to study the asymmetric mass transport under nanoconfinement. A nonequilibrium steady-state molecular theory is developed to account for the intricate charge regulation effect of the weak polyampholyte and to address the coupling between the polymer conformation and the external electric field. On the basis of this state-of-the-art theoretical method, we present a comprehensive theoretical description of the stimuli-responsive structural behaviors and transport properties inside the nanopore with all molecular details considered. Our model demonstrates that by incorporating a gradient of pH sensitivity into the polymer coatings of the nanopore, a variety of asymmetric charge patterns and functional structures can be achieved, in a pH-responsive manner that allows for multiple functions to be implemented into the designed system. The asymmetric charge pattern inside the nanopore leads to an electrostatic trap for major current carriers, which turns the nanopore into an ionic rectifier with a rectification factor above 1000 at optimized pH and salt concentration. Our theory further predicts that the nanopore design behaves like a double-gated nanofluidic device with pH-triggered opening of the gates, which can serve as an ion pump and pH-responsive molecular filter. These results deepen our understanding of asymmetric transport in nanoconfined systems and provide guidelines for designing polymer-coated smart nanopores.Direct nitrogen photofixation is a feasible solution toward sustainable production of ammonia under mild conditions. However, the generation of active sites for solar-dirven nitrogen fixation not only limits the fundamental understanding of the relationship among light absorption, charge transfer, and catalytic efficiency but also influences the photocatalytic activity. Herein, we report two-dimensional boron-doped niobic acid nanosheets with oxygen vacancies (B-Vo-HNbO3 NSs) for efficient N2 photofixation in the absence of any scavengers and cocatalysts. Impressively, B-Vo-HNbO3 NS as a model catalyst achieves the enhanced ammonia evolution rate of 170 μmol gcat-1 h-1 in pure water under visible-light irradiation. The doublet coupling representing 15NH4+ in an isotopic labeling experiment and in situ infrared spectra confirm the reliable ammonia generation. The experimental analysis and density functional theory (DFT) calculations indicate that the strong synergy of boron dopant and oxygen vacancy regulates band structure of niobic acid, facilitates photogenerated charge transfer, reduces free energy barriers, accelerates reaction kinetics, and promotes the high rates of ammonia evolution. This work provides a general strategy to design active photocatalysts toward solar N2 conversion.A unique method for the synthesis of cyclopentenes and cyclohexenes has been achieved by the coupling of diketones and alkenes under cobalt(II) catalysis and dimethyl sulfoxide involvement. Under optimal conditions, the formation of five- and six-membered rings can be readily controlled by the α-position substitution of styrenes. This process is proposed to proceed through a reaction sequence of oxidative coupling (mediated by K2S2O8), regioselective alkene insertion (promoted by cobalt), and intramolecular attack of the resulting allylcobalt species on the carbonyl group or methyl group in the reactive methylene process.Lithium-sulfur (Li-S) batteries have received extensive attention because of their high theoretical energy density and low cost. However, the low sulfur utilization and the shuttle effect of polysulfide cause low initial capacity and serious capacity decay. Herein, fluorinated graphite (FG) is introduced to the cathode to alleviate these issues. The results indicated that the FG could provide additional capacity during the first discharge process and increase the porosity and polarity of the cathode via in situ formation of lithium fluoride (LiF) nanocrystals, which can enhance the infiltration of electrolyte and polysulfide adsorption. As a result, the as-prepared cathode containing FG shows a high initial specific capacity of 1602 mA h g-1 and the reversible specific capacity is 650 mA h g-1 at 0.5C after 300 cycles. Moreover, its specific capacity remains at 860 mA h g-1 at 5C, which is 367% higher than that of the sample without FG. This paper provides a new strategy to improve the energy density and the cycle stability of Li-S batteries.GtfB-type α-glucanotransferase enzymes from glycoside hydrolase family 70 (GH70) convert starch substrates into α-glucans that are of interest as food ingredients with a low glycemic index. Characterization of several GtfBs showed that they differ in product- and substrate specificity, especially with regard to branching, but structural information is limited to a single GtfB, preferring mostly linear starches and featuring a tunneled binding groove. Here, we present the second crystal structure of a 4,6-α-glucanotransferase (Limosilactobacillus reuteri NCC 2613) and an improved homology model of a 4,3-α-glucanotransferase GtfB (L. fermentum NCC 2970) and show that they are able to convert both linear and branched starch substrates. Compared to the previously described GtfB structure, these two enzymes feature a much more open binding groove, reminiscent of and evolutionary closer to starch-converting GH13 α-amylases. Sequence analysis of 287 putative GtfBs suggests that only 20% of them are similarly "open" and thus suitable as broad-specificity starch-converting enzymes.ConspectusDerivatization is the fine chemistry that can produce chemical compounds from similar precursors and has been widely used in the field of organic synthesis to achieve diversification of molecular properties and functionalities. Ligand-protected metal nanoclusters (NCs) are metallic molecules with a definite molecular formula, well-defined molecular structure, and molecular-like physical and chemical properties. Unlike organic compounds, which have almost infinite species, until now only hundreds of metal NC species have been discovered, and only a few of them have been structurally resolved. Therefore, the diversification of NC species and functions is highly desirable in nanoscience and nanochemistry. As an efficient approach for generating a library of compounds from a given precursor, derivatization chemistry is not only applicable in producing new organic compounds but also a promising strategy for generating new metal NC species with intriguing properties and functions. The key to the derivatizNCs. Through these delicate derivatization reactions, we can produce Au25SR18 derivatives with new physical, chemical, and biological properties, including electronic structures, photoluminescence, surface reactivity, and antimicrobial properties. Finally, we provide our perspectives on the opportunities and challenges of metal NC derivatization.The derivatization chemistry of metal NCs can not only diversify the properties and functions of metal NCs but also help us understand the structure-property relationship and design principles of metal nanomaterials, which will help advance the research frontier of nanoscience toward atomic precision.The high in vivo stability of 2,2-dihydroxymethyl-3-[18F]fluoropropyl-2-nitroimidazole ([18F]DiFA) prompted us to evaluate neopentyl as a scaffold to prepare a radiotheranostic system with radioiodine and astatine. Three DiFA analogues with one, two, or without a hydroxyl group were synthesized. While all 125I-labeled compounds remained stable against nucleophilic substitution, only a 125I-labeled neopentyl glycol was stable against cytochrome P450 (CYP)-mediated metabolism and showed high stability against in vivo deiodination. 211At-labeled neopentyl glycol also remained stable against both nucleophilic substitution and CYP-mediated metabolism. 211At-labeled neopentyl glycol showed the biodistribution profiles similar to those of its radioiodinated counterpart in contrast to the 125I/211At-labeled benzoate pair. The urine analyses confirmed that 211At-labeled neopentyl glycol was excreted in the urine as a glucuronide conjugate with the absence of free [211At]At-. These findings indicate that neopentyl glycol would constitute a promising scaffold to prepare a radiotheranostic system with radioiodine and 211At.
Lovastatin is an antilipidemic drug that belongs to the class of statins that has poor oral bioavailability due to its low solubility and variable dissolution rate. The main aim of this study was to enhance the solubility and dissolution rate of the drug and understand its oral bioavailability.

Lovastatin nanosuspension was formulated using a solventanti-solvent method using a probe sonication technique. A nanosuspension was prepared, using hydroxypropyl methylcellulose (HPMC) K15M and pluronic F68 as stabilizers. The formulated nanosuspensions were characterized for particle size, polydispersity index (PDI) zeta potential, surface morphology, and
release rate. Further, an
bioavailability study and stability studies were also performed.

Optimized formulation showed a particle size of 127±0.01 nm, a PDI of 0.492±0.001, and a zeta potential of -37.9 mV, which indicates good stability. Morphological study showed that the particles were in the nano range. The drug content was found to be in the range of 73-87%.
release revealed much faster release of the drug in one hour compared to the pure drug and its marketed formulation.
bioavailability study was carried out in Wistar rats, which showed improvement in bioavailability by approximately 2.5 folds compared with the marketed formulation. Stability studies indicated that the optimized formulation F2 was more stable at 4°C±2°C.

The prepared lovastatin nanosuspension showed improvement in solubility, dissolution rate, and oral bioavailability compared to the pure drug and its marketed formulation. Hence, lovastatin nanosuspension may be a potentially valuable tool for improving the oral bioavailability of lovastatin.
The prepared lovastatin nanosuspension showed improvement in solubility, dissolution rate, and oral bioavailability compared to the pure drug and its marketed formulation. Hence, lovastatin nanosuspension may be a potentially valuable tool for improving the oral bioavailability of lovastatin.
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