A new asymmetric synthetic route to (+)- and (-)-limaspermidine was devised, starting with chirally resolved enantiomerically pure 2-pyrone Diels-Alder cycloadducts. This route utilizes intramolecular Pd-catalyzed aromatic C-H amidation and imino-Diels-Alder reactions to construct the key indoline and indolizidine subunits onto the central cyclohexane core, allowing the straightforward formal total syntheses of both (+)- and (-)-limaspermidine.
View Article and Find Full Text PDFThe ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum (high p_{T}) hadron trigger in proton-proton and central Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV. A data-driven statistical method is used to mitigate the large uncorrelated background in central Pb-Pb collisions.
View Article and Find Full Text PDFSilver-based metal-organic decomposition inks composed of silver salts, complexing agents and volatile solvents are now the subject of much research due to the simplicity and variability of their preparation, their high stability and their relatively low sintering temperature. The use of this type of ink in inkjet printing allows for improved cost-effective and environmentally friendly technology for the production of electrical devices, including flexible electronics. An approach to producing a silver salt-based reactive ink for jet printing has been developed.
View Article and Find Full Text PDFK^{+}K^{-} pairs may be produced in photonuclear collisions, either from the decays of photoproduced ϕ(1020) mesons or directly as nonresonant K^{+}K^{-} pairs. Measurements of K^{+}K^{-} photoproduction probe the couplings between the ϕ(1020) and charged kaons with photons and nuclear targets. The kaon-proton scattering occurs at energies far above those available elsewhere.
View Article and Find Full Text PDFAlthough the construction of peptides with well-defined three-dimensional structures and predictable functions, including biological activity, using conformationally constrained β-amino acids has been shown to be a very successful strategy, their broad application is limited by access to the appropriate building blocks. In particular, - and -stereoisomers of 2-aminocyclopentanecarboxylic acid (ACPC) are of high interest. The scalable synthesis of all four stereoisomers of Fmoc derivatives of ACPC is presented with NMR-based analysis methods for their enantiomeric purity.
View Article and Find Full Text PDFThe production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.
View Article and Find Full Text PDFGlobal declines in tree populations have led to dramatic shifts in forest ecosystem composition, biodiversity, and functioning. These changes have consequences for both forest plant and wildlife communities, particularly when declining species are involved in coevolved mutualisms. Whitebark pine () is a declining keystone species in western North American high-elevation ecosystems and an obligate mutualist of Clark's nutcracker (), an avian seed predator and disperser.
View Article and Find Full Text PDFVitamin D deficiency (VDD) is a global problem, however, there were no Ukrainian guidelines devoted to its screening, prevention, and treatment, which became the reason for the Consensus creation. This article aimed to present the Consensus of Ukrainian experts devoted to VDD management. Following the creation of the multidisciplinary Consensus group, consent on the formation process, drafting and fine-tuning of key recommendations, and two rounds of voting, 14 final recommendations were successfully voted upon.
View Article and Find Full Text PDFLayered Double Hydroxide (LDH) is an α-modification of the M-host (M ) hydroxide, in which some part of the M-host cations is replaced by M-guest cations (M or M ). The emerging excess positive charge is compensated by the intercalation of anions into the interlayer space, which also contains water molecules. LDHs exhibit anion exchange properties.
View Article and Find Full Text PDFThe most precise measurements to date of the _{Λ}^{3}H lifetime τ and Λ separation energy B_{Λ} are obtained using the data sample of Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV collected by ALICE at the LHC. The _{Λ}^{3}H is reconstructed via its charged two-body mesonic decay channel (_{Λ}^{3}H→^{3}He+π^{-} and the charge-conjugate process).
View Article and Find Full Text PDFPhotothermal therapy is one of the most promising and rapidly developing fields in modern oncology due to its high efficiency, localized action, and minimal invasiveness. Polymeric nanoparticles (NPs) incorporating low molecular-weight photothermal dyes are capable of delivering therapeutic agents to the tumor site, releasing them in a controlled manner, and providing tumor treatment under external light irradiation. The nanoparticle synthesis components are critically important factors that influence the therapeutically significant characteristics of polymeric NPs.
View Article and Find Full Text PDFThe transverse-momentum (p_{T}) spectra and coalescence parameters B_{2} of (anti)deuterons are measured in p-p collisions at sqrt[s]=13 TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest p_{T} in the event (p_{T}^{lead}>5 GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE.
View Article and Find Full Text PDFWe study the polarization of inclusive J/ψ produced in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.
View Article and Find Full Text PDFRacemic carboxylic acid, a Diels-Alder cycloadduct derived from 5-bromo-3-phenyl-α-pyrone and acrylate dienophile, was resolved into enantiomers by diastereomeric salt crystallization. Quinidine was used as a sole resolving base. The salt of (+)-acid crystallized from aqueous acetonitrile solution.
View Article and Find Full Text PDFGradual dehydration is one of the frequent lethal yet poorly understood stresses that bacterial cells constantly face in the environment when their micro ecotopes dry out, as well as in industrial processes. Bacteria successfully survive extreme desiccation through complex rearrangements at the structural, physiological, and molecular levels, in which proteins are involved. The DNA-binding protein Dps has previously been shown to protect bacterial cells from many adverse effects.
View Article and Find Full Text PDFThe evolution of surface damage in laser direct cleaning (LDC) of nanoparticulate contamination on silicon (Si) was theoretically and experimentally investigated. Nanobumps with a volcano-like shape were found in near-infrared laser cleaning of polystyrene latex nanoparticles on Si wafers. According to the finite-difference time-domain simulation and the high-resolution surface characterization, unusual particle-induced optical field enhancement in the vicinity of the interface between Si and nanoparticles is mainly responsible for the generation of volcano-like nanobumps.
View Article and Find Full Text PDFTargeted nanoparticles of different origins are considered as new-generation diagnostic and therapeutic tools. However, there are no targeted drug formulations within the composition of nanoparticles approved by the FDA for use in the clinic, which is associated with the insufficient effectiveness of the developed candidates, the difficulties of their biotechnological production, and inadequate batch-to-batch reproducibility. Targeted protein self-assembling nanoparticles circumvent this problem since proteins are encoded in DNA and the final protein product is produced in only one possible way.
View Article and Find Full Text PDFThe extreme aggressiveness and lethality of many cancer types appeal to the problem of the development of new-generation treatment strategies based on smart materials with a mechanism of action that differs from standard treatment approaches. The targeted delivery of nanoparticles to specific cancer cell receptors is believed to be such a strategy; however, there are no targeted nano-drugs that have successfully completed clinical trials to date. To meet the challenge, we designed an alternative way to eliminate tumors in vivo.
View Article and Find Full Text PDFThe structure of phosphorus-containing dendrimers has been studied by IR spectroscopy and optical polarization microscopy. The repeating units of dendrimer molecules are mesogens. This property arises from the conjugation of the aromatic ring and the hydrazone group.
View Article and Find Full Text PDFSBC82 is a recently described representative of the phylum from lichen-covered tundra soil. Cells of this bacterium occur within unusual saccular chambers, with the chamber envelope formed by tightly packed fibrils. These extracellular structures were most pronounced in old cultures of strain SBC82 and were organized in cluster-like aggregates.
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