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Terry Wentworth posted an update 6 months, 3 weeks ago
In this work, the coordination polyhedron stabilities and distributions of europium ions in Ca6BaP4O17 (CBPO) luminescent materials are investigated. The density functional theory (DFT)-based first principles calculation results show that the PO4 tetrahedrons can tilt in the structure, which leads to the atomic distortion of O13 and O12 in CBPO and the Eu2+/Eu3+-doped systems. The energy scale of about ∼0.1 eV suggests that stabilities of coordination polyhedrons are easily influenced by dynamic factors. The atomic distortion and vacancy of work as charge compensations in CBPOEu3+, and three lattice sites of europium are extracted and summarized. The X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) confirm that Eu3+ can occupy the Ca1, Ca2 and Ba sites of CBPO. The combination of first principles calculation and X-ray absorption fine structure (XAFS) provides more information about microstructures of luminescent materials.A recombinant HALO-GFP fusion protein was designed and isolated to demonstrate the feasibility of controlling the number and orientation of protein ligands to be conjugated on colloidal gold nanoparticles. AuNPs functionalized with exactly one or exactly two GFP molecules exhibited fully preserved functionality of the protein. The method is very straightforward and generally provides highly bioactive nanoparticle-protein conjugates.The cerebellum is a potent anti‑epileptic target for deep brain stimulation in patients with drug‑resistant epilepsy. The effects of such stimulation, however, may also favor seizure activity. Our goal was to investigate the effect of cerebellar electrical stimulation (ES) alone and in combination with the anti‑epileptic drug diazepam (DIA) on seizure outcome. We used a rat model of pentylenetetrazol kindling, which is characterized by seizures followed by deteriorations in central benzodiazepine‑GABAA (BDZ‑GABAA) receptors. We tested the effects of ES alone and in combination with DIA (0.1 and 1.0 mg/kg) on seizures. Our data demonstrated 20 ES trials can prevent the recurrence of clonic‑tonic kindled seizures, administration of either DIA‑0.1 or ES (5 trials) alone is ineffective on seizures, and combining DIA‑0.1 and 5 ES or DIA‑1.0 and 5 ES caused an additive effect, prolonged the latency to seizure onset, and prevented recurrence of clonic‑tonic seizures. We also observed that ES alone produced either facilitation or inhibition of seizures on EEG. In contrast, the same ES inhibited EEG seizures when delivered after a combination of DIA‑1.0 and 5 ES and ultimately prevented the facilitation of the discharges. Lastly, we demonstrated that seizure suppression is intensified when cortical ES is performed after DIA administration. Our data supported the hypothesis that both BDZ‑GABAA receptor activity along with cerebellar output comprise the potential mechanisms underlying the peculiar effects of deep brain stimulation in the cerebellum on seizures.In humans, pyruvate dehydrogenase complex (PDC) deficiency impairs brain energy metabolism by reducing the availability of the functional acetyl‑CoA pool. This “hypometabolic defect” results in congenital lactic acidosis and abnormalities of brain morphology and function, ranging from mild ataxia to profound psychomotor retardation. Our previous study showed reduction in total cell number and dendritic arbors in the cerebellar Purkinje cells in systemic PDC‑deficient mice. Phenylbutyrate has been shown to increase PDC activity in cultured fibroblasts from PDC‑deficient patients. Hence, we investigated the effects of postnatal (days 2‑35) phenylbutyrate administration on the cerebellar Purkinje cell population in PDC‑deficient female mice. Histological analyses of different regions of cerebellar cortex from the brain‑specific PDC‑deficient saline‑injected mice revealed statistically significant reduction in the Purkinje cell density and increased cell size of the individual Purkinje cell soma compared to control PDC‑normal, saline‑injected group. Administration of phenylbutyrate to control mice did not cause significant changes in the Purkinje cell density and cell size in the studied regions. In contrast, administration of phenylbutyrate variably lessened the ill effects of PDC deficiency on Purkinje cell populations in different areas of the cerebellum. Our results lend further support for the possible use of phenylbutyrate as a potential treatment for PDC deficiency.Neurodegeneration in Parkinson’s disease (PD) includes processes of chronic inflammation and oxidative stress which are related to dysregulation in the homeostasis of iron metabolism. Hepcidin is a peptide hormone responsible for systemic iron homeostasis and simultaneously the inflammatory response protein, induced in response to interleukin 6 (IL‑6). check details We assessed the serum concentration of hepcidin and IL‑6 in the groups of patients with PD treated only pharmacologically with optimal individualized therapy (MT) and treated additionally with deep brain stimulation (DBS), compared to the control group. The serum concentrations of hepcidin and IL‑6 in the group of all PD patients were significantly higher than in the control group. In the group of PD patients treated with DBS hepcidin and IL‑6 concentrations were significantly higher compared to the control group. Additionally, the positive correlations between serum hepcidin and IL‑6 were found in the PD (MT and DBS) and PD‑DBS group. The obtained results may indicate the influence of immunological mechanisms on iron metabolism and oxidative stress, in particular when the inflammatory process is more active in the DBS‑treated group. This effect can be protective as well as neurodegenerative.The brain endocannabinoid system has been shown to play a role in many physiological processes, including mood, learning and memory. It is also involved in the pathogenesis of anxiety, depression, mood disorders, as well as neurodegenerative disorders, although the exact mechanisms by which cannabinoid receptors interfere in these disorders are not well established. The aim of the present study was to evaluate the effects of cannabinoid ligands HU‑210 (CB1 receptor agonist) and SR 141716A (CB1 receptor antagonist) on learning and memory processes of rats with depressive – like state, induced by bilateral olfactory bulbectomy. The bilateral olfactory bulbectomy (OBX) is a validated model of depression, which can be used also as an animal model of Alzheimer’s disease. We found that the subchronic treatment of OBX rats with HU 210 and SR 141716A exerted modulatory effect on rat’s performance in both active avoidance (shuttle box) and passive avoidance (step through) tests. HU 210 ameliorated the memory deficits of OBX rats; however, the scores of the sham‑operated controls had not been reached.