481 research outputs found

    Mechanics and Mathematical Modeling of Class III Treatment with Orthodontic Appliances with a Movable Ramp

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    Treatment of class III is a current problem in orthodontics that requires constant improvement of its methods, development of new or modifications of known methods and techniques. We have developed and studied the modification of removable functionally-directing orthodontic appliances for treatment of Class III, which consists of a plastic base, vestibular arc, retaining clasps, ramp, which is connected with the base by means of two torsion springs. Its usage ensures a prolonged contact of ramp with the teeth. We studied two types of club-shaped springs (torsion springs): one spring, which create an amortization effect during the action of the ramp, but do not change its inclination angle and second one – spring that seek to increase the angle of the ramp inclination due to the disclosure of its curl

    Flavonoids as Potential Drugs for VPS13-Dependent Rare Neurodegenerative Diseases

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    Several rare neurodegenerative diseases, including chorea acanthocytosis, are caused by mutations in the VPS13A–D genes. Only symptomatic treatments for these diseases are available. Saccharomyces cerevisiae contains a unique VPS13 gene and the yeast vps13∆ mutant has been proven as a suitable model for drug tests. A library of drugs and an in-house library of natural compounds and their derivatives were screened for molecules preventing the growth defect of vps13∆ cells on medium with sodium dodecyl sulfate (SDS). Seven polyphenols, including the iron-binding flavone luteolin, were identified. The structure–activity relationship and molecular mechanisms underlying the action of luteolin were characterized. The FET4 gene, which encodes an iron transporter, was found to be a multicopy suppressor of vps13∆, pointing out the importance of iron in response to SDS stress. The growth defect of vps13∆ in SDS-supplemented medium was also alleviated by the addition of iron salts. Suppression did not involve cell antioxidant responses, as chemical antioxidants were not active. Our findings support that luteolin and iron may target the same cellular process, possibly the synthesis of sphingolipids. Unveiling the mechanisms of action of chemical and genetic suppressors of vps13∆ may help to better understand VPS13A–D-dependent pathogenesis and to develop novel therapeutic strategies.publishersversionpublishe

    DETERMINATION OF OPTIMIZATION WAYS OF RE-PROTHESIS USING VARIOUS SCHEMES GNATHOLOGICAL SUPPORT OF PATIENTS AT THE PREPARATORY STAGE TO THE ORTHOPEDIC CORRECTION OF PATIENTS WITH OCCLUSIVE IATROGENIC DISORDERS OF TOOTH-JAW APPARATUS

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    We brought to the light that one of the the most controversial issues is the moment of adaptation to reconstructive procedures. Often it becomes unclear which and in which order to use medical diagnostic equipment, to training for fixed prosthetic stages. Our studies make it possible to predict not only the treatment time, but the amount of occlusal adjustment in conjunction with the reconstruction of the position of the mandible.One of the most debated issues is the time of adaptation to reconstructive manipulation. Often it becomes unclear how and in what order medical diagnostic equipment should be used in the preparatory stages of the stationary prosthetics. Our studies make it possible to predict not only the treatment time, and the amount of occlusal adjustment in conjunction with the reconstruction of the lower jaw. Keywords: tooth-jaw apparatus, temporomandibular joint, violation functional occlusion, dental surgery, medical diagnostic devices, muscle disorders, adaptation, occlusal splint, occlusal adjustment, chewing muscles, provisional design

    Функціональний стан м’язів зубощелепного апарату до та після лікування дітей з аномаліями прикусу та мовленнєвими порушеннями

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    During the examination of orthodontic patients, children with speech disorders were found. The myodynamic balance of antagonistic muscles and synergistic muscles is the relative stability of masticatory and mimic muscles, which for a long time persists without noticeable oscillations, contributes to the relatively stable state of dentoalveolar apparatus. The aim of the study – to determine the functional status of muscles of the dentoalveolar apparatus before and after treatment of children with anomalies of bite and speech disorders. Materials and Methods. To achieve study objectives for treatment we selected 44 patients with severe orthodontic pathology and speech disorders, with normal hearing and intellect. The method of a total (surface) electromyography was used to determine and analyze the indices of bioelectric activity of the muscles. Results and Discussion. There was normalization of parameters of bioelectric activity, decrease of parafunctional manifestations in muscles and decrease of the frequency of outbreaks of spontaneous activity of muscles at rest; normalization of the average amplitude of biopotentials in the state of activity, absence of fragmentation, improvement of synchronization and coordination of contractions of examined muscles in all pathologies of dental occlusion after the treatment. Conclusions. The orthodontic treatment performed provided the restoration of the neuromuscular balance of the dentoalveolar apparatus of patients with various dental occlusion pathologies, which has a beneficial effect on the correction of speech disorders.При обследовании ортодонтических пациентов были дети с речевыми нарушениями. Миодинамическое равновесие мышц-антагонистов и синергистов – это относительная устойчивость жевательных и мимических мышц, которая в течении длительного времени сохраняется без заметных изменений, способствует относительной стабильности зубочелюстного аппарата. Цель исследования – определить функциональное состояние мышц зубочелюстного аппарата до и после лечения детей с аномалиями прикуса и речевыми нарушениями. Материалы и методы. Для достижения поставленной цели было принято на лечение 44 пациента с выраженной ортодонтической патологией и речевыми нарушениями с нормальным слухом и интеллектом. Для определения и анализа показателей биоэлектрической активности мышц использован метод суммарной (поверхностной) электромиографии. Результаты исследований и их обсуждение. После проведённого лечения наблюдали нормализацию показателей биоэлектрической активности, уменьшение парафункциональних проявлений в мышцах и частоты вспышек спонтанной активности мышц в состоянии покоя, нормализация средней амплитуды биопотенциалов в состоянии активности, отсутствие фрагментаций, улучшение синхронности и координации сокращений обследованных мышц при всех патологиях прикуса. Выводы. Проведённое ортодонтическое лечение обеспечило восстановление нейромышечного баланса зубочелюстного аппарата пациентов с различными патологиями прикуса, что имеет благоприятное воздействие на коррекцию речевых нарушений.Під час обстеження ортодонтичних пацієнтів були діти з мовленнєвими порушеннями. Міодинамічна рівновага м’язів-антагоністів та синергістів – це відносна стійкість жувальних та мімічних м’язів, що протягом тривалого часу зберігається без помітних коливань, сприяє відносно стабільного стану зубощелепного апарату. Мета дослідження – визначити функціональний стан м’язів зубощелепного апарату до та після лікування дітей з аномаліями прикусу та мовленнєвими порушеннями. Матеріали і методи. Для досягнення поставленої мети було прийнято на лікування 44 пацієнти з вираженою ортодонтичною патологією та мовленнєвими порушеннями із нормальним слухом та інтелектом. Для визначення та аналізу показників біоелектричної активності м’язів використано метод сумарної (поверхневої) електроміографії. Результати досліджень та їх обговорення. Після проведеного лікування спостерігали нормалізацію показників біоелектричної активності, зменшення парафункціональних проявів у м’язах та частоти спалахів спонтанної активності м’язів у стані спокою, нормалізація середньої амплітуди біопотенціалів у стані активності, відсутність фрагментацій, покращення синхронності та координації скорочень обстежених м’язів при усіх патологіях прикусу. Висновки. Проведене ортодонтичне лікування забезпечило відновлення нейром’язового балансу зубощелепного апарату пацієнтів із різними патологіями прикусу, що має сприятливий вплив на корекцію мовленнєвих порушень

    Two chemically distinct root lignin barriers control solute and water balance.

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    Lignin is a complex polymer deposited in the cell wall of specialised plant cells, where it provides essential cellular functions. Plants coordinate timing, location, abundance and composition of lignin deposition in response to endogenous and exogenous cues. In roots, a fine band of lignin, the Casparian strip encircles endodermal cells. This forms an extracellular barrier to solutes and water and plays a critical role in maintaining nutrient homeostasis. A signalling pathway senses the integrity of this diffusion barrier and can induce over-lignification to compensate for barrier defects. Here, we report that activation of this endodermal sensing mechanism triggers a transcriptional reprogramming strongly inducing the phenylpropanoid pathway and immune signaling. This leads to deposition of compensatory lignin that is chemically distinct from Casparian strip lignin. We also report that a complete loss of endodermal lignification drastically impacts mineral nutrients homeostasis and plant growth

    Genomic landscape of drug response reveals novel mediators of anthelmintic resistance

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    Like other pathogens, parasitic helminths can rapidly evolve resistance to drug treatment. Understanding the genetic basis of anthelmintic drug resistance in parasitic nematodes is key to tracking its spread and improving the efficacy and sustainability of parasite control. Here, we use an in vivo genetic cross between drug-susceptible and multi-drug-resistant strains of Haemonchus contortus in a natural host-parasite system to simultaneously map resistance loci for the three major classes of anthelmintics. This approach identifies new alleles for resistance to benzimidazoles and levamisole and implicates the transcription factor cky-1 in ivermectin resistance. This gene is within a locus under selection in ivermectin-resistant populations worldwide; expression analyses and functional validation using knockdown experiments support that cky-1 is associated with ivermectin survival. Our work demonstrates the feasibility of high-resolution forward genetics in a parasitic nematode and identifies variants for the development of molecular diagnostics to combat drug resistance in the field

    Coordination between microbiota and root endodermis supports plant mineral nutrient homeostasis

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    Plant roots and animal guts have evolved specialized cell layers to control mineral nutrient homeostasis. These layers must tolerate the resident microbiota while keeping homeostatic integrity. Whether and how the root diffusion barriers in the endodermis, which are critical for the mineral nutrient balance of plants, coordinate with the microbiota is unknown. We demonstrate that genes controlling endodermal function in the model plant Arabidopsis thaliana contribute to the plant microbiome assembly. We characterized a regulatory mechanism of endodermal differentiation driven by the microbiota with profound effects on nutrient homeostasis. Furthermore, we demonstrate that this mechanism is linked to the microbiota's capacity to repress responses to the phytohormone abscisic acid in the root. Our findings establish the endodermis as a regulatory hub coordinating microbiota assembly and homeostatic mechanisms

    Search for non-relativistic Magnetic Monopoles with IceCube

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    The IceCube Neutrino Observatory is a large Cherenkov detector instrumenting 1km31\,\mathrm{km}^3 of Antarctic ice. The detector can be used to search for signatures of particle physics beyond the Standard Model. Here, we describe the search for non-relativistic, magnetic monopoles as remnants of the GUT (Grand Unified Theory) era shortly after the Big Bang. These monopoles may catalyze the decay of nucleons via the Rubakov-Callan effect with a cross section suggested to be in the range of 1027cm210^{-27}\,\mathrm{cm^2} to 1021cm210^{-21}\,\mathrm{cm^2}. In IceCube, the Cherenkov light from nucleon decays along the monopole trajectory would produce a characteristic hit pattern. This paper presents the results of an analysis of first data taken from May 2011 until May 2012 with a dedicated slow-particle trigger for DeepCore, a subdetector of IceCube. A second analysis provides better sensitivity for the brightest non-relativistic monopoles using data taken from May 2009 until May 2010. In both analyses no monopole signal was observed. For catalysis cross sections of 1022(1024)cm210^{-22}\,(10^{-24})\,\mathrm{cm^2} the flux of non-relativistic GUT monopoles is constrained up to a level of Φ901018(1017)cm2s1sr1\Phi_{90} \le 10^{-18}\,(10^{-17})\,\mathrm{cm^{-2}s^{-1}sr^{-1}} at a 90% confidence level, which is three orders of magnitude below the Parker bound. The limits assume a dominant decay of the proton into a positron and a neutral pion. These results improve the current best experimental limits by one to two orders of magnitude, for a wide range of assumed speeds and catalysis cross sections.Comment: 20 pages, 20 figure
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