22 research outputs found

    Kpp and KKp Clusters

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    The three-body kaonic Kpp and KKp clusters are studied using the method of hyperspherical harmonics (HH) in momentum representation and differential Faddeev equations (DFE). We use different NN and KN interactions. Results obtained by the methods of HH and DFE are in reasonable agreement. The binding energy and the width show very strong dependence on the KN potential. We have two different classes of results: the results based on phenomenological strong KN potential, and the results obtained with much weaker chiral SU(3)-based KN potential

    Deleterious variants in TRAK1 disrupt mitochondrial movement and cause fatal encephalopathy

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    This is the author accepted manuscript. The final version is available from Oxford University Press via the DOI in this record.The corrigendum to this article is in ORE: http://hdl.handle.net/10871/33588Cellular distribution and dynamics of mitochondria are regulated by several motor proteins and a microtubule network. In neurons, mitochondrial trafficking is crucial because of high energy needs and calcium ion buffering along axons to synapses during neurotransmission. The trafficking kinesin proteins (TRAKs) are well characterized for their role in lysosomal and mitochondrial trafficking in cells, especially neurons. Using whole exome sequencing, we identified homozygous truncating variants in TRAK1 (NM_001042646:c.287-2A > C), in six lethal encephalopathic patients from three unrelated families. The pathogenic variant results in aberrant splicing and significantly reduced gene expression at the RNA and protein levels. In comparison with normal cells, TRAK1-deficient fibroblasts showed irregular mitochondrial distribution, altered mitochondrial motility, reduced mitochondrial membrane potential, and diminished mitochondrial respiration. This study confirms the role of TRAK1 in mitochondrial dynamics and constitutes the first report of this gene in association with a severe neurodevelopmental disorder.D.M.E. and J.K. are supported by the Office of Naval Research (ONR) Grant N000141410538. M.S. is supported by the BBSRC (BB/K006231/1), a Wellcome Trust Institutional Strategic Support Award (WT097835MF, WT105618MA), and a Marie Curie Initial Training Network (ITN) action PerFuMe (316723). M.C.V.M., J.S., H.P., C.F., T.V. and W.A.G. are supported by the NGHRI Intramural Research Program. G.R. is supported by the Kahn Family Foundation and the Israeli Centers of Excellence (I-CORE) Program (ISF grant no. 41/11)

    Real-time laser speckle contrast imaging for intraoperative neurovascular blood flow assessment: animal experimental study

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    The use of various blood flow control methods in neurovascular interventions is crucial for reducing postoperative complications. Neurosurgeons worldwide use different methods, such as contact Dopplerography, intraoperative indocyanine videoangiography (ICG) video angiography, fluorescein angiography, flowmetry, intraoperative angiography, and direct angiography. However, there is no noninvasive method that can assess the presence of blood flow in the vessels of the brain without the introduction of fluorescent substances throughout the intervention. The real-time laser-speckle contrast imaging (LSCI) method was studied for its effectiveness in controlling blood flow in standard cerebrovascular surgery cases in rat common carotid arteries, such as proximal occlusion, trapping, reperfusion, anastomosis, and intraoperative vessel thrombosis. The real-time LSCI method is a promising method for use in neurosurgical practice. This approach allows timely diagnosis of intraoperative disturbance of blood flow in vessels in cases of clip occlusion or thrombosis. Additionally, LSCI allows us to reliably confirm the functioning of the anastomosis and reperfusion after removal of the clips and thrombolysis in real time. An unresolved limitation of the method is noise from movements, but this does not reduce the value of the method. Additional research is required to improve the quality of the data obtained

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    The three-body kaonic KÌ…pp and KÌ…KÌ…p clusters are studied using the method of hyperspherical harmonics (HH) in momentum representation and differential Faddeev equations (DFE). We use different NN and KÌ…N interactions. Results obtained by the methods of HH and DFE are in reasonable agreement. The binding energy and the width show very strong dependence on the KÌ…N potential. We have two different classes of results: the results based on phenomenological strong KÌ…N potential, and the results obtained with much weaker chiral SU(3)-based KÌ…N potential

    The results of surgery for giant aneurysms of the middle cerebral arteries: a retrospective study

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    Background: Surgical treatment of middle cerebral artery (MCA) giant aneurysms is a challenging task. The information on its current principles is rather limited, with the publications based on isolated case reports and small series. Aim: To identify the types of procedures and evaluate the results of surgery in patients with giant MCA aneurysms. Materials and methods: We retrospectively analyzed the data on 55 patients who had undergone surgery for MCA giant aneurysms in the Burdenko Neurosurgery Center from 2010 to 2021. Thereafter 52 patients were followed up for 6 to 120 months (for 53.1 33.7 months on average). Results: The giant MCA aneurysms were located at the M1 segment bifurcation in 33 (60%) patients, within the M1 segment, in 11 (20%), M2 in 7 (12.7%), and M3 and M4 in 4 (7.3%) patients. There were 32 (58.2%) saccular and 23 (41.8%) fusiform aneurysms. Surgical interventions for MCA giant aneurysms included their neck clipping (50.9%, n = 28), clipping with formation of the arterial lumen (3.6%, n = 2), bypass procedures (34.5%, n = 19), wrapping (3.6%, n = 2), and endovascular procedures (7.3%, n = 4). Perioperative worsening of the neurologic status (The Modified Rankin Scale, mRS) was observed in 50.9% (n = 28) of the patients, and the death rate was 1.8% (n = 1). The complete closure of giant aneurysms was achieved in 78.2% (n = 43) of the cases. The long-term outcome was favorable in 76.9% of the patients (40 from 52 available for the follow up). Conclusion: Microsurgical clipping and bypass types of surgery were the most common surgical procedures for the treatment of MCA giant aneurysms. These procedures are technically complex and are associated with a relatively high number of complications. The main directions of future studies could be in the search for new and more precise diagnostic assessment of the collateral circulation in the cortical MCA branches, improvement of the algorithm for the bypass selection, as well as an investigation of the long-term results of endovascular and combined treatments. A thorough long-term postoperative patient follow-up and the possibility of high quality control angiography are of major importance

    Curing Of Diglycidal Esters Of Bisphenols With Amine Hardeners

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    The effect of hardeners on the properties of cured epoxy polymers is studied. For the purpose of synthesis of polymers with increased thermal properties. Theglycide esters of polycyclic bisphenols synthesized by us were used as a diol component. Since the thermal and heat resistance of polymers, in addition to the chemical structure of bisphenols, also depend on the structure of the hardener used, amine hardeners of different chemical structure are used to improve the thermal parameters of polymers, both heat resistance and heat resistance. The influence of the chemical structure of these hardeners on the properties of epoxy polymers is studied. Cured epoxy polymers are characterized by high heat resistance. High heat resistance results are obtained by 4,4′-diaminodiphenylsulfone, benzidine, 4,4′-diaminodiphenyloxide and other aromatic diamines. Polymers obtained by curing with these hardeners are deformed in the temperature range of 220-245°C. The use of the above hardeners gives high results in terms of heat resistance. In all cases, the polymers obtained on the basis of these hardeners decrease in weight by 10% in the temperature range of 340-400°C

    Ultrashort optical solitons in transparent nonlinear media with arbitrary dispersion

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    We consider the propagation of ultrashort optical pulses in nonlinear fibers and suggest a new theoretical framework for the description of pulse dynamics and exact characterization of solitary solutions. Our approach deals with a proper complex generalization of the nonlinear Maxwell equations and completely avoids the use of the slowly varying envelope approximation. The only essential restriction is that fiber dispersion does not favor both the so-called Cherenkov radiation, as well as the resonant generation of the third harmonics, as these effects destroy ultrashort solitons. Assuming that it is not the case, we derive a continuous family of solitary solutions connecting fundamental solitons to nearly single-cycle ultrashort ones for arbitrary anomalous dispersion and cubic nonlinearity
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