• Copeland Nelson opublikował 1 rok, 3 miesiące temu

    A series of crystalline phases composed of trimetallic 3d-5d-5d’ Fe9[Re(CN)8]6-x[W(CN)8]x(MeOH)24·yMeOH (x = 1 (1), 2 (2), 3 (3), 4 (4) and 5 (5); y = 10-15) clusters were obtained by altering the octacyanidometalate composition. The temperature dependent studies involving SC XRD, SQUID magnetic measurements, IR spectroscopy and 57Fe Mössbauer spectroscopy revealed reversible phase transition with the retention of single crystal character in each congener. The transition was assisted by reversible spin-crossover (SCO) HSFeII↔LSFeII transition at the central Fe1(ii) site for Fe9Re5W1 (1), Fe9Re4W2 (2), Fe9Re3W3 (3) and Fe9Re2W4 (4). In contrast, the tungsten-rich congener Fe9Re1W5 (5) exhibited nontrivial behavior with the SCO transition being stopped halfway through the cooling process, to be completed with single electron transfer (ET) from the external Fe2(ii) center towards one of the neighboring W(v) sites. The critical temperature Tc of SCO has been systematically increased from 193 K (1) to 247 K (4). All experimental data indicate the domination of the Fe(ii)-W(v) valence states in all crystals 1-5, however, with increasing quantity of [W(CN)8]3- (and decreasing quantity of [Re(CN)8]3-), the valence equilibrium Fe(ii)-W(v) ↔ Fe(iii)-W(iv) was systematically shifted to the right, starting from congener 3. The overall electronic configuration at low temperatures and variable amounts and location of spin carriers along the whole series suggest the remarkable competition between magnetic super-exchange Fe(ii)-CN-W(v) interactions and intermolecular interactions. The observed behavior is in line with the information collected previously for the bimetallic congeners Fe9Re6 and Fe9W6, to shed light on the role of the mixed tri-metallic composition in changing the properties observed for the relevant bimetallic cyanido-bridged skeletons.Infrared (IR) imaging can be used for fast, accurate and non-destructive pathology recognition of biopsies when supported by machine learning algorithms. Transflection mode of measurements has the potential to be translated into the clinic due to economic reasons of large-scale imaging with the need for inexpensive substrates. Unfortunately, in this mode spectral distortions originating from light interference appear. Due to this fact transmission measurement mode is more frequently used in pathology recognition. Nevertheless, this measurement mode also is not devoid of spectral distortion effects like scattering. However, this effect is better understood and there are preprocessing algorithms to minimize it. In this work, we investigated the influence of interference effects on spectral quality of pancreatic tissues measured in transmission and transflection mode with Fourier tranform IR (FT-IR) microscopy using samples embedded with and without paraffin. The removal of paraffin leads to an altered magnitude of interference in transflection and provides a platform for a detailed analysis of its effect on the spectra of biological material, since the same sample is measured with different interference conditions. Moreover, the potential of transflection mode measurements in histological classification of analyzed samples was investigated and compared with classification results for transmission mode.Novel antimony(iii) imidazole selone complexes in a super crowded environment are reported for the first time. The super bulky selone antimony complexes, [IPr*Se(SbCl3)2] (1) and [IPr*Se(SbBr3)2] (2), were isolated from the reactions between IPr*Se (IPr*Se = [1,3-bis(2,6-diphenylmethylphenyl)imidazole selone]) and suitable antimony(iii) halides. 1 and 2 are dinuclear complexes with a Sb  Se ratio of 1  0.5 with an unusual coordination mode of selone. The molecules 1 and 2 consist of both Menshutkin-type Sbπaryl interactions and a Sb-Se coordination bond. However, the reaction between antimony(iii) halides and [(IPaul)Se] ([(IPaul)Se] = [1,3-bis(2,4-methyl-6-diphenyl phenyl)imidazole selone]) with a spatially defined steric impact gave the dinuclear complex [(IPaul)Se(SbCl3)]2 (3) and the mononuclear complex [(IPaul)Se(SbBr3)] (4) without Menshutkin-type interactions. The Sb  Se ratio in 3 and 4 is 1  1. Interestingly, the Menshutkin-type interaction was absent in 3 and 4 due to the efficient coordinating ability of the ligand [(IPaul)Se] with the Sb(iii) center compared to that of the super bulky ligand IPr*Se. The thermal property of these antimony selone complexes was also investigated. Density functional theory (DFT) calculations were carried out on the model systems [L(SbCl3)2] (1A), [L(SbCl3)] (1B), [L'(SbCl3)2] (1C), and [L'(SbCl3)] (1D), where L = [1,3-bis(2,6-diisopropyl-4-methyl phenyl)imidazole selone] and L’ = [1,3-bis(phenyl)imidazole selone], to understand the nature of orbitals and bonding situations. The computed metrical parameters of 1A are in good agreement with the experimental values. Natural population analysis of the model system reveals that the natural charge and total population of antimony(iii) are comparable. The unequal interaction between selenium and antimony obtained using Wiberg bond indices (WBIs) is fully consistent with the findings of the single-crystal X-ray studies.The formation of G-quadruplexes (G4) in human telomere and other important biological regions inhibits the replication and transcription of DNA, thereby influencing further cell proliferation. The investigation of G4 formation and unfolding is vital for understanding their modulation in biological processes and life science. Photo regulation is a facile and sensitive approach for monitoring the structures of biomacromolecules and material surface properties. The nanopore-based technique is also prevalent for label-free single-molecule characterization with high accuracy. This study provides a combination of solid-state nanopore technology with light-switch as a platform for the modulation of human telomere G4 formation and splitting under switchable light exposure. The introduction of molecular switch, namely azobenzene moiety at different positions of the DNA sequence influences the formation and stability of G4. Three azobenzenes immobilized on each of the G-quartet plane (hTelo-3azo-p) or four azobenzenes on the same plane (hTelo-4azo-4p) of the human telomere G4 sequence realized the reversible control of G4 folding/unfolding at the temporal scale upon photo regulation, and the formation and splitting of G4 with hTelo-4azo-4p is slower and not thorough compared to that with hTelo-3azo-p due to the coplanar steric hindrance. Moreover, the G4 formation recorded with the combined nanopore and photo-responsive approach was also characterized with fluorescence, and the variation in the fluorescence intensity of the NMM and G4 complex exhibited a different tendency under reverse light irradiation due to the distinct interactions of NMM with the azobenzene-modified G4. Our study demonstrated a controllable and sensitive way for the manipulation of G4 structures, which will be inspiring for the intervention of G4-related cell senescence, cancer diagnosis and drug exploration.Introducing photoswitches into the DNA G-quadruplex provides excellent opportunities to control folding and unfolding of these assemblies, demonstrating their potential in the development of novel nanodevices with medical and nanotechnology applications. Using a quantum mechanics/molecular mechanics (QM/MM) scheme, we carried out a series of simulations to identify the effect of the size and substitution patterns of three azobenzene derivatives (AZ1, AZ2 and AZ3) on the excitation energies of the two lowest excited states of the smallest photoswitchable G-quadruplex reported to date. We demonstrated that the size and the substitution pattern do not affect the ultrafast cis-trans photoiomerization mechanism of the azobenzene derivatives significantly, in agreement with the experiment. However, molecular dynamics simulations revealed that while AZ2 and AZ3 G-quadruplexes are structurally stable during the simulations, the AZ1 G-quadruplex undergoes larger structural changes and shows two ground state populationr theoretical findings provide support to a recent study of the photoresponsive formation of photoswitchable G-quadruplex motifs.Correction for 'Metal-free [3+3] benzannulation of 1-indanylidene-malononitrile with Morita-Baylis-Hillman carbonates direct access to functionalized fluorene and fluorenone derivatives’ by Ya-Sa Xie et al., Chem. Commun., 2020, 56, 1948-1951, DOI 10.1039/D0CC00143K.

    Aging is characterized by the progressive loss of physiological capacity. At the cellular level, two key hallmarks of the aging process include telomere length (TL) shortening and cellular senescence. Repeated intermittent hyperoxic exposures, using certain hyperbaric oxygen therapy (HBOT) protocols, can induce regenerative effects which normally occur during hypoxia. The aim of the current study was to evaluate whether HBOT affects TL and senescent cell concentrations in a normal, non-pathological, aging adult population.

    Thirty-five healthy independently living adults, aged 64 and older, were enrolled to receive 60 daily HBOT exposures. Whole blood samples were collected at baseline, at the 30

    and 60

    session, and 1-2 weeks following the last HBOT session. Peripheral blood mononuclear cells (PBMCs) telomeres length and senescence were assessed.

    Telomeres length of T helper, T cytotoxic, natural killer and B cells increased significantly by over 20% following HBOT. The most significant change was no0.0001). T-cytotoxic senescent cell percentages decreased significantly by -10.96%±12.59 (p=0.0004) post-HBOT. In conclusion, the study indicates that HBOT may induce significant senolytic effects including significantly increasing telomere length and clearance of senescent cells in the aging populations.

    Posttraumatic stress disorder (PTSD) is a prevalent, chronic, and severe disorder related to traumatic events. Women are disproportionately affected by PTSD than men and are more at risk in the occurrence of sexual assault victimization. Estimates suggest that 50% of women develop PTSD following sexual assault and successful clinical management can be challenging. Growing evidence has implicated neural, immune, and endocrine alterations underpinning PTSD, but only few studies have assessed the evolution of acute PTSD in women.

    This study aims to measure whether the onset of PTSD is associated with accelerated aging in women following sexual assault. We hypothesize that the increase of allostatic load caused by PTSD leads to neuroprogression. We will implement a randomized clinical trial to compare responses to treatment with either interpersonal psychotherapy adapted for PTSD (IPT-PTSD) or the selective serotonin reuptake inhibitor sertraline.

    We will include women between 18 and 45 years of age, who extted in early 2021. This research project has obtained a grant from the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 2014/12559-5).

    We expect to provide insight into the consequences of recent sexual assault exposure in women by investigating the degree of neuroprogression developing from an early stage of PTSD. We also expect to provide important evidence on the efficacy of a non-exposure psychotherapy (IPT-PTSD) to mitigate PTSD symptoms in recently sexually assaulted women. Further, we aim to obtain evidence on how treatment outcomes are associated with neuroprogression measures.

    Brazilian Clinical Trials Registry RBR-3z474z; http//www.ensaiosclinicos.gov.br/rg/RBR-3z474z/.

    DERR1-10.2196/19162.

    DERR1-10.2196/19162.

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