Peptide bond formation from the pure protonated glycine dimer, H(Gly), and from the mixed protonated glycine-diglycine dimer, HGly(Gly), was recently found experimentally to occur in gas-phase experiments in the absence of any catalyst and especially under anhydrous conditions [, 2023, , 775]. In this contribution we further examine the conditions of such unimolecular reactions by means of density-functional theory calculations at the DFT/M06 2X/6-311G++(2df,p) level, focusing in particular on the role played by the protonation site. Two pathways, stepwise and concerted, are identified for the pure protonated dimer, and six pathways are examined for the mixed dimer.
View Article and Find Full Text PDFIntroduction: Tobacco use remains a significant public health issue worldwide, causing over 7 million deaths annually. Polytobacco use has become a common phenomenon. This study aims to analyze reasons for cigarette and tobacco product use, dual use and poly use among university students by sex, in China and Cyprus, selected owing to their still high consumption rates.
View Article and Find Full Text PDFTo provide a novel and personalized method (and Irradiation Personalized) using patient-specific circulating blood flows and individualized time-dependent irradiation distributions, to quantify the dose delivered to blood in large vessels during proton or photon external beam radiotherapy.Patient-specific data were obtained from ten cancer patients undergoing radiotherapy, including the blood velocity field in large vessels and the temporal irradiation scheme using photons or protons. The large vessels and the corresponding blood flow velocities are obtained from phase-contrast MRI sequences.
View Article and Find Full Text PDFThe dorsal midbrain comprises dorsal columns of the periaqueductal grey matter and corpora quadrigemina. These structures are rich in beta-endorphinergic and leu-enkephalinergic neurons and receive GABAergic inputs from substantia nigra pars reticulata. Although the inferior colliculus (IC) is mainly involved in the acoustic pathways, the electrical and chemical stimulation of central and pericentral nuclei of the IC elicits a vigorous defensive behaviour.
View Article and Find Full Text PDFRecent pump-probe experiments [Albrechtsen et al., Nature 623, 319 (2023)] have explored the gradual solvation of sodium cations in contact with helium nanodroplets, using a fully solvated xenon atom as a probe exerting a repulsive interaction after its own ionization. In this communication, we computationally examine by means of atomistic ring-polymer molecular dynamics the mechanisms of successive ionizations, shell formation, and Coulomb ejection that all take place within tens of picoseconds and show that their interplay subtly depends on the time delay between the two ionizations but also on the droplet size.
View Article and Find Full Text PDFOral methadone maintenance is a widely adopted and effective treatment for heroin and other opioid dependencies. However, injectable methadone usage may pose greater risks than heroin itself. Despite decades of oral methadone treatment in Spain, there is limited understanding of the motivations for parenteral consumption.
View Article and Find Full Text PDFFormal assessment of myocardial viability (MV) is challenging in acute myocardial infarction-related cardiogenic shock (AMI-CS) patients receiving Impella mechanical circulatory support, as the cardiac magnetic resonance gold standard technique is not feasible due to the metallic components of the device. 18-fluorodesoxyglucose metabolic myocardial positron emission tomography (FDG-PET) may represent a valid and feasible alternative to obtain semi-quantitative and objective evidence of MV during Impella support. We hereby report the first series of sequential AMI-CS patients who received FDG-PET scanning to assess MV during Impella support to demonstrate the safety and feasibility of this approach.
View Article and Find Full Text PDFThe analysis of the shift in photoluminescence emission for a blend of polyvinylcarbazole and acrylonitrile derivative compounds is reported. The small-molecule compounds have different functional groups, phenyl, pyridine, or methyl phenyl, attached to an acrylonitrile group. According to the functional group, the blue emission for pure dye shifts to green or yellowish in the blend film.
View Article and Find Full Text PDFIntroduction: Exogenous haptoglobin administration may enhance plasma-free hemoglobin (pfHb) clearance during hemolysis and reduce its end-organ damage: we systematically reviewed and summarized available evidence on the use of haptoglobin as a treatment for hemolysis of any cause.
Methods: We included studies describing haptoglobin administration as treatment or prevention of hemolysis-related complications. Only studies with a control group reporting at least one of the outcomes of interest were included in the quantitative synthesis.
One strategy to improve olive (Olea europaea ) tree drought tolerance is through the symbiosis of arbuscular mycorrhizal fungi (AMF), which helps alleviate water deficit through a combination of morphophysiological effects. Cuttings of olive varieties Arbequina (A) and Barnea (B) were grown with (+AMF) or without (-AMF) inoculum in the olive grove rhizosphere soil. One year after establishment, pots were exposed to four different water regimes: (1) control (100% of crop evapotranspiration); (2) short-period drought (20days); (3) long-period drought (25days); and (4) rewatering (R).
View Article and Find Full Text PDFBackground And Purpose: As no guidelines for pencil beam scanning (PBS) proton therapy (PT) of paediatric posterior fossa (PF) tumours exist to date, this study investigated planning techniques across European PT centres, with special considerations for brainstem and spinal cord sparing.
Materials And Methods: A survey and a treatment planning comparison were initiated across nineteen European PBS-PT centres treating paediatric patients. The survey assessed all aspects of the treatment chain, including but not limited to delineations, dose constraints and treatment planning.
The purpose of this invited paper is to show the learning disabilities field what LDbase is, why it's important for the field, what it offers the field, and examples of how you can leverage LDbase in your own work.
View Article and Find Full Text PDFWith the general population aging, both life expectancy and the number of left ventricular assist device (LVAD) implantations in elderly patients are growing. Nevertheless, their perceived long-term quality of life, including psychological aspects, coupled with the respective caregiver's burden, remain under-reported. In light of the rising number of octogenarians with LVAD who necessitate broader healthcare provider involvement, we assessed the long-term quality of life, as defined by both the 36-item short-form health (SF-36) survey and the EuroQol 5 dimensions, 5-level questionnaire (EQ-5D-5L)-including the visual analog scale-in octogenarian LVAD patients who had received treatment at our institution.
View Article and Find Full Text PDFCell Oncol (Dordr)
August 2024
Neoplastic progression involves complex interactions between cancer cells and the surrounding stromal milieu, fostering microenvironments that crucially drive tumor progression and dissemination. Of these stromal constituents, cancer-associated fibroblasts (CAFs) emerge as predominant inhabitants within the tumor microenvironment (TME), actively shaping multiple facets of tumorigenesis, including cancer cell proliferation, invasiveness, and immune evasion. Notably, CAFs also orchestrate the production of pro-angiogenic factors, fueling neovascularization to sustain the metabolic demands of proliferating cancer cells.
View Article and Find Full Text PDFThe abundance of extraterrestrial methanol makes the reaction between methanol molecules in a molecular cluster a possible key step in the search for mechanisms for the formation of more complex molecules under the conditions of the interstellar medium as well as circumstellar and planetary atmospheres. The reaction leading to the formation of the dimethyl ether ion from a methanol molecule interacting with a protonated methanol ion via the elimination of a water molecule is a basic mechanism for the formation of complex organic molecules. Here, we experimentally examine such reactions in the gas phase, analyzing the production and reactivity of protonated cluster ions formed by the ionization of a supersonic jet of methanol.
View Article and Find Full Text PDFWe reported a case of blood culture-negative infective endocarditis on a native valve, where the clinical presentation was exclusively related to extensive cerebral ischemia secondary to multiple systemic septic cardioembolic events. The cause was ascribed to subacute infection, presumably transmitted by cat scratch, documented by positive serologic findings.
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2024
The quantum dynamics of vibrational polaritonic states arising from the interaction of a bistable molecule with the quantized mode of a Fabry-Perot microcavity is investigated using a generic asymmetric double-well potential as a simplified one-dimensional model of a reactive molecule. After discussing the role of the light-matter coupling strength in the emergence of avoided crossings between polaritonic states, we investigate the possibility of using these crossings to trigger a dynamical switching of these states from one potential well to the other. Two schemes are proposed to achieve this coherent state switching, either by preparing the molecule in an appropriate vibrational excited state before inserting it into the cavity, or by applying a short laser pulse inside the cavity to obtain a coherent superposition of polaritonic states.
View Article and Find Full Text PDFPolarizable force fields are an essential component for the chemically accurate modeling of complex molecular systems with a significant degree of fluxionality, beyond harmonic or perturbative approximations. In this contribution we examine the performance of such an approach for the vibrational spectroscopy of the alanine amino acid, in the gas and condensed phases, from the Fourier transform of appropriate time correlation functions generated along molecular dynamics (MD) trajectories. While the infrared (IR) spectrum only requires the electric dipole moment, the vibrational circular dichroism (VCD) spectrum further requires knowledge of the magnetic dipole moment, for which we provide relevant expressions to be used with polarizable force fields.
View Article and Find Full Text PDFThe multimorbidity approach involves promotional and preventive strategies. The demand for rehabilitation services has grown exponentially in recent years, leading to the urgency of rethinking care delivery. In Chile, there are laws, programs, and guidelines that, from their theoretical basis, include a person-centered care focus.
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