Frontal Sections Research Articles

Computational Fluid Dynamics and Experimental Analysis of a Wind Turbine Blade’s Frontal Section with and without Arrays of Dimpled Structures

Horizontal axis wind turbines are used for energy generation at domestic as well as industrial levels. In the wind turbines, a reduction in drag force and an increase in lift force are desired to increase the energy efficiency. In this research work, computational fluid dynamics (CFD) analysis has been performed on a turbine blade’s frontal section with an NACA S814 profile. The drag force has been reduced by introducing an array of dimpled structures at the blade surface. The dimpled structures generate a turbulent boundary layer flow on its surface that reduces the drag force and modifies the lift force because it has greater momentum than the laminar flow. The simulation results are verified by the experimental results performed in a wind tunnel and are in close harmony with the simulated results. For accurate results, CFD is performed on the blade’s frontal section at the angle of attack (AOA) with a domain of 0° to 80° and at multiple Reynolds numbers. The local attributes, lift force, drag force and pressure coefficient are numerically computed by using the three models on Ansys fluent: the Spalart-Allmaras, the k-epsilon (RNG) and the k-omega shear stress transport (SST).

New Insights into Turbulent Spots

Transitional–turbulent spots bridge the deterministic laminar state with the stochastic turbulent state and affect the transition zone length in engineering flows. Turbulent spot research over the past four decades has expanded from incompressible flat-plate boundary layer and pipe flow to hypersonic boundary layer flow, turbomachinery flow, channel flow, plane Couette flow, and a range of more complex flows. Progress has been made on the origination, composition, demarcation, growth, mutual interaction, reproduction, sustainability, and self-organization of turbulent spots. The hypothesis that transitional–turbulent spots are a basic module of the fully turbulent boundary layer has been proven through the discovery of locally generated turbulent–turbulent spots dominating the wall layer. Splitting of transitional–turbulent spots in pipe flow has been linked to a life cycle localized in the spot frontal section. This review discusses these advances and outlines future research directions.

Magnetic Resonance Imaging and Cross-Sectional Anatomy of the Eye and the Optic Nerve in the Egyptian Donkey (Equus asinus)

The eye is a high sense organ which is susceptible to many infectious and traumatic diseases. Using an accurate diagnostic imaging technique became essential for early detection and control of these diseases. The current investigation is proposed to fully describe the normal magnetic resonance imaging (MRI) appearance of the eye, extraocular structures and the optic nerve in the donkey with the aid of the anatomical sections. Eight fresh cadaveric heads of adult donkeys of both sexes were used; two were scanned using an MRI scanner of 1.5 Tesla magnet, and six were frozen to be sectioned into transverse (n=3) and frontal (n=3) sections. The accessed MR images were serially selected in matching to their corresponding gross sections. These MR images provided a comprehensive assessment of the eyeball structures (choroid, ciliary body, iris, cornea, sclera, anterior and posterior chambers, and vitreous body), the ocular adnexa (upper, lower and third eyelids, lacrimal gland, tarsal gland, superficial gland of the third eyelid, extraocular muscles and orbital fat), the various parts of the optic nerve (intraocular, intraorbital, intracanalicular, intracranial) and its surrounding meningeal sheath complex. However, it was difficult to outline the retina. The current investigation administrated a precise anatomical atlas of the eye, periorbital structures and optic nerve in the donkey assisting in the interpretation and diagnosis of both ocular diseases and optic neuropathy.

Structural Organization of the Motor Speech Area of an Outstanding Writer.

The current study is concerned with the macroscopic and cytoarchitectonic structure of the motor speech area 44 in the left and right hemispheres of the brain of an outstanding writer (age 62 years). In a series of 20-μm frontal total paraffin sections stained with cresyl violet by the Nissl method, the density of total glia, the density of satellite glia, and the density of neurons surrounded by satellite glia were analyzed. The motor speech area of the cortex of the famous writer is characterized by a more complex macroscopic and cytoarchitectonic structure. In Broca's area, the density of total glia, satellite glia, and the neurons surrounded by satellite glia in associative layer III of area 44 were higher than in the control (brains of 5 men aged 59-71 years).

2D size of trabecular bone structure units (BSU) correlate more strongly with 3D architectural parameters than age in human vertebrae

Bone tissue is continuously remodeled. In trabecular bone, each remodeling transaction forms a microscopic bone structural unit (BSU), also known as a hemiosteon or a trabecular packet, which is bonded to existing tissue by osteopontin-rich cement lines. The size and shape of the BSUs are determined by the size and shape of the resorption cavity, and whether the cavity is potentially over- or under-filled by the subsequent bone formation. The present study focuses on the recently formed trabecular BSUs, and how their 2D size and shape changes with age and trabecular microstructure. The study was performed using osteopontin-immunostained frontal sections of L2 vertebrae from 8 young (aged 18.5-37.6years) and 8 old (aged 69.1-96.4years) control females, which underwent microcomputed tomography (μCT) imaging prior to sectioning. The contour of 4230 BSU profiles (181-385 per vertebra) within 1024 trabecular profiles were outlined, and their 2D width, length, area, and shape were assessed. Of these BSUs, 22 (0.5%) were generated by modeling-based bone formation (i.e. without prior resorption), while 99.5% were generated by remodeling-based bone formation (i.e. with prior resorption). The distributions of BSU profile width, length, and area were significantly smaller in the old versus young females (p<0.005), and the median profile width, length, and area were negative correlated with age (p<0.018). Importantly, these BSU profile size parameters were more strongly correlated with trabecular bone volume (BV/TV, p<0.002) and structure model index (SMI, p<0.008) assessed by μCT, than age. Moreover, the 2D BSU size parameters were positively correlated to the area of the individual trabecular profiles (p<0.0001), which were significantly smaller in the old versus young females (p<0.024). The BSU shape parameters (aspect ratio, circularity, and solidity) were not correlated with age, BV/TV, or SMI. Collectively, the study supports the notion that not only the BSU profile width, but also its length and area, are more influenced by the age-related bone loss and shift from plates to rods (SMI), than age itself. This implies that BSU profile size is mainly driven by changes in the trabecular microstructure, which affect the size of the resorption cavity that the BSU refills.

Immunoreactivity of acetylcholinesterase and M1 muscarinic receptors in the hippocampus and striatum of rats treated with Rebaudioside A.

Rebaudioside A (RebA) is a steviol glycoside used for production of sweeteners. It was shown that the glycosides affect memory and learning processes. The aim of the study was to investigate neurons immunoreactive for acetylcholinesterase (AChE) and M1 muscarinic receptors (mAChRs-M1) of the hippocampal CA1 and CA3 fields and striatal caudateputamen (CP) and globus pallidus (GP) in rats receiving RebA. RebA was administrated to adult rats for 45 days in dilutions of 1 mg and 2 mg RebA/ml water. Indirect peroxidase-antiperoxidase immunohistochemical reaction was conducted on frontal sections containing the hippocampus and striatum with use of antibodies against AChE and mAChRs-M1. Immunoreactive for the studied proteins neurons were morphologically and morphometrically assessed in hippocampal CA1 and CA3 fields and in CP and GP. Microscopic observations did not reveal significant changes in morphology of immunoreactive neurons, which suggests no neurotoxic effect of the studied glycoside on these cells. Morphometric analyses revealed an increase in the density of AChE and mAChRs-M1 immunoreactive neurons. A decrease in reaction intensity of AChE-positive neurons was also demonstrated in the hippocampal CA1 field and in GP. In contrast, an increase in reaction intensity of mAChRs-M1-positive neurons was found in CA1, CA3 fields and in CP and GP. The results of our preliminary studies indicate that RebA administrated to rats has an impact on cholinergic neurons in the studied area. The results suggest a possible increase in the activity of the cholinergic system, responsible for memory and learning processes, after administration of RebA.

Comparison of micro-CT and CBCT in the preparation of teeth for the role of samples in in vitro research

Introduction. The thickness of dentine is an important factor affecting the results of experimental studies. An adequately precise and repeatable method for its measurement is of key importance for ensuring the reliability and credibility of research. Aim. The aim of this study was to compare conical beam computed tomography (CBCT) and microtomography (micro-CT) for the preparation of teeth as specimens in medical research. Material and methods. From among 100 extracted teeth, 4 teeth with appropriate structural features confirmed in CBCT images were selected. They were embedded in silicone mass and cut in a horizontal plane in such a way that the intersection plane was parallel to the plane defined by the pulp horns. Next, the samples were subjected to conical beam computed tomography and microtomography. Two authors independently measured the distance between the plane of intersection and the pulp horns on the obtained frontal and sagittal sections. The obtained measurements were statistically processed. Results. The values obtained with CBCT were higher than those obtained with micro-CT. Statistically significant differences were found for two of four samples. Conclusions. CBCT is not sufficient for precise preparation of teeth for the role of research specimens.

SEVERE ASYMMETRICAL ATROPHY OF THE MAXILLA, COMBINED TRANS-ZYGOMATIC IMPLANT PROTOCOL. CLINICAL CASE

Angular and trans-zygomatic implantation is an alternative to most maxillary augmentations with severe deformations and extreme atrophy. The usage of the frontal section of the maxilla for implantation surgery after tooth extraction provides effective stability for implants and prostheses. This is the most frequently used protocol for intraoperative direct replacement with traditional and trans-zygomatic implants after extraction of the frontal teeth. Immediate functional loading with provisional restorations is always guaranteed. This saves a considerable amount of treatment time. Augmentations on the maxilla are not necessary. We present a clinical case of implant prosthetic rehabilitation using conventional and trans-zygomatic implants in extreme atrophy and deformations of the maxillary frontal region.

Anti-Lift Assessment of Multi-Flap Motorcycle Winglet for Track Usage Via Wind Tunnel Test

Abstract— In motorcycle racing it is important to travel at high speed. However, involuntary lift of the front wheel could occur at high speed of travelling. This results in the loss of traction, stability and control over the motorcycle. This undesired phenomenon could be minimized by adding downforce at the frontal section of the motorcycle. The aim of this study was to generate supplementary downforce via the integration of anti-lift winglet at the frontal section of the motorcycle. This study tested on the effects given by the variation on the numbers of multi-element flaps with respect to anti-lift force generated. The anti-lift winglet assisted the motorcyclist for greater control and stability during high speed of travelling by being planted onto the ground. It was observed that the highest downforce is generated by winglets with the highest number of multi-element flaps. Conclusively, the installation of the winglet on the motorcycle significantly improves control and stability during high speed of travelling by being planted onto the ground. For future studies, other parameters such as the angle of attack for the winglet and the general shape of the winglets could be examined. Keywords— Semi-active winglet, Downforce, Mechanism, Multi-element wing.

Morphological and morphometric description of neurons in the sensorimotor cortex of the rat brain after ligation of the common carotid arteries

The aim of the study was to present structural and morphometric changes in the sensorimotor cortex neurons of the rat brain after ligation of the common carotid arteries (LCCA).Material and methods. Cerebral ischemia was modeled in white Wistar rats by irreversible bilateral ligation of common carotid arteries (2-vessel model of incomplete global ischemia, without hypotension). For morphological studies, histological (hematoxylin–eosin, thionin staining according to the Nissl method), immunohistochemical (NSE, GFAP) and morphometric methods were used. The control group consisted of intact animals (n=6), the material was taken 1, 3, 7, 14 and 30 days after the experimental modeling of LCCA (n=30). Morphometric analysis was performed on preparations of frontal sections of the brain using the ImageJ 1.53; statistical hypotheses were tested using the Statistica 8.0.Results. It was found that the number density of normochromic neurons decreased throughout the study period and reached its minimum values 30 days after LCCA: the decrease in layer III was 75.9%, and in layer V it was 72.6%. There was a decrease in the total number density of neurons. After 1 and 3 days, in layers III and V, the content of hyperchromic neurons with intact shape of perikarya increased. The numerical density of hyperchromic neurons with a spindle-shaped perikaryon, a deformed nucleus, as well as neurons with a homogeneous cytoplasm had maximum values after 30 days.Conclusion. After irreversible bilateral LCCA, together with an increase in the number density of hyperchromic pycnotic neurons, as well as neurons with homogenization of the cytoplasm and nucleus, a decrease in the NSE content in the cytoplasm of pyramidal neurons was noted, which may indicate a decrease in the expression of this protein and a decrease in the functional activity of neurons by the end of the study period. An increase in hyperchromic pycnotic neurons and shadow cells against the background of a decrease in the number density of normochromic and hyperchromic non-pycnotic neurons may indicate a significant severity of the processes occurring after LCCA and the irreversibility of destructive changes in nerve cells.

Tendinous annulus of Zinn for a common origin of the extraocular rectus muscles: a histological study of the orbital apex from donated elderly cadavers.

The medial, inferior, lateral, and superior rectus muscles (MR, IR, LR, SR), levator palpebrae superioris (LPS), and superior oblique muscle (SO) seem to originate from the tendinous annulus of Zinn, ring-like fibrous tissue crossing the bony orbital fissure. We observed the histological annulus structure using semi-serial histological sections of the orbital apex from 30 elderly donated cadavers. Nearly frontal sections demonstrated a ring-like fibrous structure (a candidate annulus) connecting or embedding four rectus muscles. The candidate annulus did not contain the LPS and SO, and, in the anterior side, the latter muscles originated from the optic canal opening. Far posterior to the annulus, there was a common tendon of the MR, IR, and LR attached to the infero-medial wall of the bony orbital fissure. At the superior part, the annulus is tightly attached to the optic nerve sheath and the periosteum. Sagittal (or Horizontal) sections clearly exhibited parts of the annulus at the MR (SR) origin. Both sagittal and horizontal sections displayed (1) the common origin of the three rectus muscles near the oculomotor nerve in the bony fissure and (2) an accessory, independent muscle bundle of the MR originating from the superomedial margin of the optic canal near the origins of the LPS or SO. Consequently, the so-called tendinous annulus appeared not to provide origins of all six muscles.

Histological and Immunohistochemical Studies to Determine the Mechanism of Cleft Palate Induction after Palatal Fusion in Mice Exposed to TCDD.

Rupture of the basement membrane in fused palate tissue can cause the palate to separate after fusion in mice, leading to the development of cleft palate. Here, we further elucidate the mechanism of palatal separation after palatal fusion in 8–10-week-old ICR female mice. On day 12 of gestation, 40 μg/kg of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), sufficient to cause cleft palate in 100% of mice, was dissolved in 0.4 mL of olive oil containing toluene and administered as a single dose via a gastric tube. Fetal palatine frontal sections were observed by H&E staining, and epithelial cell adhesion factors, apoptosis, and cell proliferation were observed from the anterior to posterior palate. TUNEL-positive cells and Ki67-positive cells were observed around the posterior palatal dissection area of the TCDD-treated group. Moreover, in fetal mice exposed to TCDD, some fetuses exhibited cleft palate dehiscence during fusion. The results suggest that palatal dehiscence may be caused by abnormal cell proliferation in epithelial tissues, decreased intercellular adhesion, and inhibition of mesenchymal cell proliferation. By elucidating the mechanism of cleavage after palatal fusion, this research can contribute to establishing methods for the prevention of cleft palate development.

Дослідження ЕЕГ-предикторів нейромедіаторної і нейрогліальної активності, особливостей перебудови міжцентральних відносин мозку у пацієнтів з тяжкою ЧМТ

Метою цього дослідження було вивчення впливу Цитофлавіну на перебудову міжцентральних відносин мозку, зміни нейромедіаторної і нейрогліальної активності в пацієнтів із тяжкою черепно-мозковою травмою (ЧМТ). Матеріал і методи дослідження. Дослідження проводилося в 2011–2014 роках у ДОКТМО на базі кафедри анестезіології та інтенсивної терапії ФПО Донецького національного медичного університету ім. Горького. Обстежено 60 пацієнтів із діагнозом «тяжка черепно-мозкова травма». Дизайн дослідження: відкрите проспективне дослідження за типом «випадок-контроль», що проводиться в групі пацієнтів із тяжкою ЧМТ. Рівень порушення свідомості при надходженні до стаціонару від 4 до 8 балів за шкалою коми Глазго, вік від 20 до 70 років. 1-ша група складалася з 30 пацієнтів, які отримували терапію за стандартним протоколом. 2-га група — з 30 хворих, які отримували, крім терапії по протоколу, препарат Цитофлавін із першої доби після отримання травми у вигляді інфузійного розчину 5 мл в 100 мл фізіологічного розчину 1 раз на добу (в 1-й групі — плацебо) внутрішньовенно повільно крапельно протягом 7 діб. Досліджували електричну активність мозку у хворих із тяжкою ЧМТ методами кількісної електроенцефалографії за допомогою інтегрального кількісного аналізу, внутрішьно- і міжпівкульної когерентності досліджуваних частотних діапазонів. Результати та обговорення. На першому етапі дослідження падіння рівнів міжпівкульної когерентності, виявлене в обох групах хворих із тяжкою ЧМТ, з вираженою синхронізацією біопотенціалів неокортексу справа (посилення внутрішньопівкульної когерентності потиличної кори з центральними і фронтальними ділянками (С4-О2 і Fр2-T4)) відображало крайню напруженість гомеостазу ЦНС і домінування неспецифічної аварійної адаптації з ознаками зриву адаптаційних можливостей. У хворих із тяжкою ЧМТ встановлено нейрофізіологічні ЕЕГ-предиктори феномена функціонального роз’єднання півкуль: істотне ослаблення міжпівкульної взаємодії в альфа-частотному діапазоні ЕЕГ у всіх симетричних відділах мозку — Fp1-Fp2, T3-T4, C3-C4, O1-O2 відведеннях, що відображає гальмівний стан кори. Проявом феномена роз’єднання зв’язків між підкірковими гангліями і корою головного мозку є виражене зниження рівнів міжпівкульної когерентності в симетричних лобових відведеннях (Fp1-Fp2), центральних (С3-С4) і потиличних відділах (О1-О2) в діапазонах тета-, альфа1-, альфаS-, бета1-, бета2-хвиль, що свідчить про дисфункцію регуляторних систем медіобазальних відділів фронтальної кори і про падіння напруженості в системах диенцефального рівня. На першому етапі дослідження в обох групах хворих із тяжкою ЧМТ встановлено вихідне зниження активності всіх досліджуваних нейромедіаторних систем практично у всіх досліджуваних відділах кори, що відображає глибоке виснаження стресреалізуючих і стреслімітуючих реакцій ЦНС. У хворих із тяжкою ЧМТ, які отримували Цитофлавін, предикторами трансформації стрес-реакції з періоду аварійної адаптації в період довгострокової адаптації є збільшення значення когерентності в альфа-діапазоні ЕЕГ-частот в центральній корі (С3-С4), проекційній зоні неспецифічного таламуса, відновлення активності верхньостовбурових структур мозку і лімбічної системи (посилення міжпівкульних діагональних когерентних зв’язків (C3-О2, С4-O1) фонової ЕЕГ в альфа-діапазоні). У хворих із тяжкою ЧМТ інтенсивна терапія з застосуванням Цитофлавіну протягом тижня відновлювала нейромедіаторний баланс, поетапно модулюючи активність адренергічної, серотонінергічної і дофамінергічної, холінергічної нейромедіаторних систем, коли стресреалізуючі реакції в процесі відновлення функцій ЦНС змінювалися стреслімітуючими реакціями, більш відповідними необхідному рівню гомеостазу. Висновки. Застосування Цитофлавіну забезпечувало енергетичну складову адекватних стресреалізуючих і стреслімітуючих процесів при тяжкій ЧМТ, їх поетапне включення у відновлення гомеостазу ЦНС. У групі пацієнтів із тяжкою ЧМТ, які отримували додатково до стандартного протоколу лікування Цитофлавін, значуще зростав шанс відновлення свідомості до 11 і більше балів за шкалою коми Глазго (ОR ± 95% ДІ = 0,22 (0,054–0,914)), значуще знижувався ризик смерті ((RR) ± 95% ДІ = 3 (1,09–8,2)) вже на 3-тю добу терапії.

Comparative morphometric analysis of age-related changes in the pyramidal neurons of the human prefrontal and posterior associative cortex from birth to 7 years

Aim: This article is devoted to the study of age-related changes in the body volume of pyramidal neurons (VP) of the human prefrontal (PFC) and posterior associative cortex (PAC) in children from birth to 7 years of age. Methods: The material consisted of left cerebral hemispheres obtained from 60 male individuals. We studied the areas 8, 45 and 10 in the PFC and area 37 in subareas 37ac, 37a, 37d in the PAC. For morphometry of pyramidal neurons in cortical sublayer III3, we used virtual images of serial frontal paraffin sections of cortex 10 thick stained by Nissl. We determined the mean value of VP (mean VP), the standard error of the mean, and the confidence interval for each age group. Results: The most significant changes in the mean VP in all studied cortical areas occurred during the first 6 months of life. The greatest increase in the VP was detected in the PFC from 3.5 to 7 years, and in the PAC from 1.5 to 3 years of age. There are close positive correlations between agerelated changes in the size of neurons in the PFC and in the PAC. Conclusion: In children, the development of pyramidal neurons of the external pyramidal plate in the PAC occurs earlier and at a more intensive pace compared to the PFC. We suggest that VP is an important quantitative indicator that allows us to assess the timing and rate of age-related structural changes in the cerebral cortex.

Rasmussen encephalitis after traumatic brain injury in a young adult / Encefalite de Rasmussen após lesão cerebral traumática em um jovem adulto

CASE PRESENTATION: Male, 33 years old, previously healthy, presented a single episode of epileptic seizure four years ago after a traumatic brain injury suffered in 2005. Throughout the evolution, seizures appeared as left eye blinks with progression to myoclonus in left hemiface, some with secondary generalization. It became more frequent, reaching about hundreds a day despite the use of carbamazepine CR 1200 mg/day, valproic acid 1500 mg/day and clobazam 60 mg/day. Video encephalogram demonstrated severe cortical dysfunction on the right hemisphere and focal epilepsy involving an ipsilateral perisylvian region. Magnetic resonance imaging revealed hippocampal sclerosis on the right, moderate volumetric reduction in the right hemisphere and cerebellum. The seizures became more frequent despite the drug adjustment with carbamazepine, acetazolamida and lamotrigina. In addition, left hand paresis appeared, and the condition evolved with epileptic status in May 2019 which partially improved after levetiracetam administration. After three months, a frontal and temporoparietal multilobar section was performed on the right hemisphere, and histopathological analysis demonstrated mild cortical atrophy, architectural disorganization of the neuronal layers and lymphohistiocytic infiltrate with microglial arrangement, compatible with Rasmussen encephalitis in subacute stage. DISCUSSION: Rasmussen encephalitis is a unilateral inflammatory brain disease of unknown etiology and progressive character. It typically manifests in childhood and early adolescence, although there are reports in adults after traumatic brain injury [1,2]. Clinically, it presents with polymorphics seizures that invariably increase in frequency, being refractory to antiepileptics. It necessarily evolves with hemiparesis, and, often, with cognitive impairment [3,4] Magnetic resonance imaging shows unihemispheric focal cortical atrophy, and electroencephalogram shows slow unihemispheric activity, with or without epileptiform activity and unilateral start of the crises. Histopathologically, there are dominant T cell encephalitis. Pharmacological management of the disease is inefficient and surgery is the preferably treatment. FINAL COMMENTS: Rasmussen encephalitis is a rare disease that typically begins in childhood and adolescence. It's pathophysiological relation with previous traumatic brain injury is not well defined. The clinical presentation is marked by cognitive deficit and polymorphic epileptic seizures, and surgery is the best option as treatment.

Bimodal expression of Wnt5a in the tooth germ: A comparative study using in situ hybridization and immunohistochemistry

BackgroundDuring tooth development, Wnt5a, a member of the noncanonical Wnt ligand, is expressed prominently in the dental mesenchyme. However, the spatiotemporal profiles of Wnt5a protein production and distribution in tooth germs are largely unknown, which impairs elucidation of the Wnt5a-mediated regulatory mechanism of tooth development. MethodsWe performed analyzes of the spatiotemporal expression of Wnt5a in embryonic tooth germs (E11.5–E18.5) by using in situ hybridization and immunohistochemistry in parallel. The developmental stages of the embryonic tooth germs were determined by HE staining. In order to compare the spatiotemporal distribution patterns of Wnt5a mRNA-expressing cells and those of Wnt5a protein-expressing cells, serial frontal sections of paraffinized mouse embryo heads were used for the analyzes. When needed, the immunohistochemistry images were subjected to digital detection analysis of Wnt5a immunostaining signal using the WinROOF 2018 Ver. 4.19.0 image processing software program. ResultsThroughout the developmental process, cells expressing Wnt5a mRNA were found in various tissues including the dental follicle, dental papilla, inner and outer enamel epithelium, stratum intermediate, and stellate reticulum. However, odontoblasts differentiating and polarizing at E18.5 were the only cells representing an accumulation of Wnt5a protein in the apical region of the odontoblast process. The Wnt5a protein was undetectable in undifferentiated mesenchymal cells as well as any other cells positive for Wnt5a mRNA. ConclusionDifferentiating odontoblasts execute Wnt5a expression, the mode of which is distinct from that executed by the other cells constituting tooth germ. Change of the mode of Wnt5a expression begins to take place in the mesenchymal cells by E18.5, starting the elongation of the cytoplasmic process.

The Role of Frontal Thrusts in Tsunami Earthquake Generation

ABSTRACT The frontal sections of subduction zones are the source of a poorly understood hazard: “tsunami earthquakes,” which generate larger-than-expected tsunamis given their seismic shaking. Slip on frontal thrusts is considered to be the cause of increased wave heights in these earthquakes, but the impact of this mechanism has thus far not been quantified. Here, we explore how frontal thrust slip can contribute to tsunami wave generation by modeling the resulting seafloor deformation using fault-bend folding theory. We then quantify wave heights in 2D and expected tsunami energies in 3D for both thrust splays (using fault-bend folding) and down-dip décollement ruptures (modeled as elastic). We present an analytical solution for the damping effect of the water column and show that, because the narrow band of seafloor uplift produced by frontal thrust slip is damped, initial tsunami heights and resulting energies are relatively low. Although the geometry of the thrust can modify seafloor deformation, water damping reduces these differences; tsunami energy is generally insensitive to thrust ramp parameters, such as fault dip, geological evolution, sedimentation, and erosion. Tsunami energy depends primarily on three features: décollement depth below the seafloor, water depth, and coseismic slip. Because frontal ruptures of subduction zones include slip on both the frontal thrust and the down-dip décollement, we compare their tsunami energies. We find that thrust ramps generate significantly lower energies than the paired slip on the décollement. Using a case study of the 25 October 2010 Mw 7.8 Mentawai tsunami earthquake, we show that although slip on the décollement and frontal thrust together can generate the required tsunami energy, &amp;lt;10% was contributed by the frontal thrust. Overall, our results demonstrate that the wider, lower amplitude uplift produced by décollement slip must play a dominant role in the tsunami generation process for tsunami earthquakes.

Co-exposure to Toluene and Noise Made Synergistic and Antagonistic Effects on Some Neurotoxic Parameters in New Zealand White Rabbits.

Numerous physical and chemical agents can induce destructive effects on the brain tissue. Noise and toluene, which are some of these harmful agents, have significant adverse effects on the brain tissue. This work aimed to investigate the neurotoxic changes induced by co-exposure to toluene and noise. A total of 24 male white New Zealand rabbits were randomly segregated into four groups, including toluene exposure, noise exposure, co-exposure to noise and toluene, and control. This in vivo study tested the neurotoxic effects of exposure to 1000 ppm toluene and 100 dB noise during two weeks (8 h/day). The serum levels of brain-derived neurotrophic factor-α (BDNF-α), malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase and total antioxidant capacity (TAC) values in the brain tissue were measured. Moreover, hematoxylin and eosin (H&E) staining was utilized for brain pathological analysis. Exposure to noise increased TAC values in the cerebral cortex. Co-exposure to toluene and noise increased the serum levels of BDNF-α. Nevertheless, exposure to noise decreased the levels of BDNF-α in serum. On the other hand, histopathological examinations using H&E staining exhibited that different signs of inflammation, such as lymphocyte infiltration, pyknosis, vacuolization, and chromatolysis were induced by exposure to noise and toluene in the cerebellum, hippocampus, and frontal section in the brain tissue. In addition, simultaneous exposure to toluene and noise induced antagonistic and synergistic changes in some neurotoxic parameters. Exposure to noise and toluene, which caused inflammation in the brain tissue cells, could be a noticeable risk factor for the neurological system. Exposure to noise increased total antioxidant capacity.Exposure to toluene decreased brain-derived neurotrophic factor-α.Exposure to noise decreased brain-derived neurotrophic factor-α.Co-exposure to noise and toluene increased brain-derived neurotrophic factor-α.Noise and toluene induced some histopathological effects on the brain tissue. The brain tissue can be adversely affected by various agents, including noise and toluene. This study aimed to examine the effects of simultaneous exposure to noise and toluene on the nervous system. Twenty-four healthy male white New Zealand rabbits were randomly divided into four groups: control, noise, toluene, and simultaneous exposure to noise and toluene. The study involved a two-week in-vivo experiment, subjecting the rabbits to 100 dB noise and 1000 ppm toluene for eight hours per day. This study showed that exposure to noise and toluene changed different parameters relating to the neurological system. Furthermore, noise and toluene induced some adverse effects on the brain tissue. This study suggested that exposure to noise and toluene can lead to harmful effects on the brain tissue, posing a significant risk to the neurological system.

Вибухо-індукована нейротравма (патофізіологічні та патоморфологічні особливості)

The article presents the results of pathophysiological and pathomorphological features which were studied in experimental blust-induced neurotrauma in rats. The relevance of this study is associated with the frequent blust neurotrauma resulting from the use of explosives in military conflicts. At the same time, neurotrauma is more common, which is clinically manifested by cognitive impairment, even with mild and moderate severity. This, in turn, leads to complications and disability for young people. The purpose of the work was to study the consequences of the air-shock wave influence on the functional and morphological states of the central nervous system. Materials and methods. The studies were carried out on 36 white male Wistar rats 5-7 months old, weighing 180-220 g. The rats were divided into two groups: I – experimental group (n=18), the animals of which were anesthetized with halothane, fixed and explosion-induced neurotraum was simulated by generating a baroacoustic wave with an excess pressure of 26.4 ± 3.6 kPa. II group was a control group (n=18). Functional changes were investigated in the Barnes maze. For pathomorphological examination, brain sections were stained with hematoxylin and eosin. The animals were kept in standard conditions and in the standard diet of the vivarium, all studies were conducted in accordance with modern international requirements and norms of humane treatment of animals (Council of Europe Convention dated 18.03.1986 (Strasbourg); Helsinki Declaration 1975, revised and supplemented in 2000, Law of Ukraine dated 21.02.2006 No. 3447-IV), which is evidenced by an extract from the protocols of the meeting of the commission on biomedical ethics. Results and discussion. Analysis of the results of memory studies in the Barnes maze showed a significant (Р &lt;0.05) increase in the latent time of entering the shelter in rats of the experimental group in the acute and early post-traumatic period, which indicates memory impairment. General characteristics of the rats behavior in the experimental group showed an increase in anxiety and disorientation. The increase in research on "fake shelters" and the chaotic movement around the facility was evidenced. Analysis of frontal histological sections of the rat brain in the dynamics of the explosion-induced neurotrauma development showed the presence of characteristic signs in the form of diffuse microhemorrhages in the hippocampus zone in the acute period of injury, diffuse areas of perivascular and pericellular edema in the early post-traumatic period and paretic dilated capillaries in the structure of the cerebral region on 2nd-3rd week of the post-traumatic period. Conclusion. Thus, quantitative (increased latent time) and qualitative (increased anxiety) signs of impaired orientational-spatial memory and the development of specific pathomorphological signs of explosive brain damage in rats of the experimental group were established

Frontal white matter lesions in Alzheimer\u2019s disease are associated with both small vessel disease and AD-associated cortical pathology

Cerebral white matter lesions (WML) encompass axonal loss and demyelination and are assumed to be associated with small vessel disease (SVD)-related ischaemia. However, our previous study in the parietal lobe white matter revealed that WML in Alzheimer’s disease (AD) are linked with degenerative axonal loss secondary to the deposition of cortical AD pathology. Furthermore, neuroimaging data suggest that pathomechanisms for the development of WML differ between anterior and posterior lobes with AD-associated degenerative mechanism driving posterior white matter disruption, and both AD-associated degenerative and vascular mechanisms contributed to anterior matter disruption. In this pilot study, we used human post-mortem brain tissue to investigate the composition and aetiology of frontal WML from AD and non-demented controls to determine if frontal WML are SVD-associated and to reveal any regional differences in the pathogenesis of WML. Frontal WML tissue sections from 40 human post-mortem brains (AD, n = 19; controls, n = 21) were quantitatively assessed for demyelination, axonal loss, cortical hyperphosphorylated tau (HPτ) and amyloid-beta (Aβ) burden, and arteriolosclerosis as a measure of SVD. Biochemical assessment included Wallerian degeneration-associated protease calpain and the myelin-associated glycoprotein to proteolipid protein ratio as a measure of ante-mortem ischaemia. Arteriolosclerosis severity was found to be associated with and a significant predictor of frontal WML severity in both AD and non-demented controls. Interesting, frontal axonal loss was also associated with HPτ and calpain levels were associated with increasing Aβ burden in the AD group, suggestive of an additional degenerative influence. To conclude, this pilot data suggest that frontal WML in AD may result from both increased arteriolosclerosis and AD-associated degenerative changes. These preliminary findings in combination with previously published data tentatively indicate regional differences in the aetiology of WML in AD, which should be considered in the clinical diagnosis of dementia subtypes: posterior WML maybe associated with degenerative mechanisms secondary to AD pathology, while anterior WML could be associated with both SVD-associated and degenerative mechanisms.