62 research outputs found
Isolation of Neural Stem Cells from the embryonic mouse hippocampus for in vitro growth or engraftment into a host tissue
For both stem cell research and treatment of the central nervous system disorders, neural stem/progenitor cells (NSPCs) represent an important breakthrough tool. In the expanded stem cell-based therapy use, NSPCs not only provide a powerful cell source for neural cell replacement but a useful model for developmental biology research. Despite numerous approaches were described for isolation of NSPCs from either fetal or adult brain, the main issue remains in extending cell survival following isolation. Here we provide a simple and affordable protocol for making viable NSPCs from the fetal mouse hippocampi, which are capable of maintaining the high viability in a 2D monolayer cell culture or generating 3D neuro-spheroids of cell aggregates. Further, we describe the detailed method for engraftment of embryonic NSPCs onto a host hippocampal tissue for promoting multilinear cell differentiation and maturation within endogenous environment. Our experimental data demonstrate that embryonic NSPCs isolated using this approach show the high viability (above 88%). Within a host tissue, these cells were capable of differentiating to the main neural subpopulations (principal neurons, oligodendrocytes, astroglia). Finally, NSPC-derived neurons demonstrated matured functional properties (electrophysiological activity), becoming functionally integrated into the host hippocampal circuits within a couple of weeks after engraftment
Zinc oxide-nickel cermet selective coatings obtained by sequential electrodeposition
The investigation of pulse electrodepositing modes influence on crystal structure, morphology and optical properties of ZnO has revealed the conditions in which quasi-one-dimensional (1D) ZnO nanorod arrays are formed as separate nanorods. Due to a sufficiently high resistance of zinc oxide, the electrodeposition of nickel on the fluorine doped tin oxide (FTO)/ZnO surfaces carried out in space between the ZnO nanorods. An incomplete filling of the gaps between nanorods by the nickel nanoparticles through subsequent Ni electrodeposition ensured the creation of ZnO–Ni graded cermets. The cermets, in which electrochemical filling of the spaces between ZnO nanorods by Ni, was performed in the pulse mode. It provided higher absorption of visible and near IR light. It was shown that the manufactured ZnO–Ni graded cermets have high light absorption combined with comparatively low thermal losses, so these cermets are promising cheap and affordable selective coatings for solar heat collectors
Optimized Model of Cerebral Ischemia In situ for the Long-Lasting Assessment of Hippocampal Cell Death
Among all the brain, the hippocampus is the most susceptible region to ischemic lesion, with the highest vulnerability of CA1 pyramidal neurons to ischemic damage. This damage may cause either prompt neuronal death (within hours) or with a delayed appearance (over days), providing a window for applying potential therapies to reduce or prevent ischemic impairments. However, the time course when ischemic damage turns to neuronal death strictly depends on experimental modeling of cerebral ischemia and, up to now, studies were predominantly focused on a short time-window—from hours to up to a few days post-lesion. Using different schemes of oxygen-glucose deprivation (OGD), the conditions taking place upon cerebral ischemia, we optimized a model of mimicking ischemic conditions in organotypical hippocampal slices for the long-lasting assessment of CA1 neuronal death (at least 3 weeks). By combining morphology and electrophysiology, we show that prolonged (30-min duration) OGD results in a massive neuronal death and overwhelmed astrogliosis within a week post-OGD whereas OGD of a shorter duration (10-min) triggered programmed CA1 neuronal death with a significant delay—within 2 weeks—accompanied with drastically impaired CA1 neuron functions. Our results provide a rationale toward optimized modeling of cerebral ischemia for reliable examination of potential treatments for brain neuroprotection, neuro-regeneration, or testing neuroprotective compounds in situ
Opposite, bidirectional shifts in excitation and inhibition in specific types of dorsal horn interneurons are associated with spasticity and pain post-SCI
Spasticity, a common complication after spinal cord injury (SCI), is frequently accompanied by chronic pain. The physiological origin of this pain (critical to its treatment) remains unknown, although spastic motor dysfunction has been related to the hyperexcitability of motoneurons and to changes in spinal sensory processing. Here we show that the pain mechanism involves changes in sensory circuits of the dorsal horn (DH) where nociceptive inputs integrate for pain processing. Spasticity is associated with the DH hyperexcitability resulting from an increase in excitation and disinhibition occurring in two respective types of sensory interneurons. In the tonic-firing inhibitory lamina II interneurons, glutamatergic drive was reduced while glycinergic inhibition was potentiated. In contrast, excitatory drive was boosted to the adapting-firing excitatory lamina II interneurons while GABAergic and glycinergic inhibition were reduced. Thus, increased activity of excitatory DH interneurons coupled with the reduced excitability of inhibitory DH interneurons post-SCI could provide a neurophysiological mechanism of central sensitization and chronic pain associated with spasticity
Atlanto-occipital catheterization of young rats for long-term drug delivery into the lumbar subarachnoid space combined with in vivo testing and electrophysiology in situ
BACKGROUND: Catheterization has been widely used in neuroscience and pain research for local drug delivery. Though different modifications were developed, the use of young animals for spinal catheterization remains limited because of a little success rate. A reliable technique is needed to catheterize young animals aimed for in vivo testing combined with spinal cord electrophysiology, often limited by animal age, to facilitate pain research. NEW METHODS: We describe intrathecal catheterization of young rats (3-week-old) through atlanto-occipical approach for long-lasting drug delivery into the lumbar subarachnoid space. The technique represents a surgical approach of minimized invasiveness that requires PE-10 catheter and few equipment of standard laboratory use. RESULTS: Behavioral assessments revealed that spinal catheterization does not change peripheral sensitivity of different modalities (thermal and mechanical) and gives no rise to locomotive deficit or anxiety-like behavior in young rats. The long-term administration of genetic material (oligodeoxynucleotides given up to 4days), examined both in vivo and in situ, produced no adverse effects on basal peripheral sensitivity, but changed the AMPA receptor-mediated currents in sensory interneurons of the spinal cord. COMPARISON WITH EXISTING METHODS: Dissimilar to already described methods, the method is designed for the use of young rats for behavioral testing in vivo and/or spinal cord electrophysiology in situ. CONCLUSIONS: A practical method for spinal catheterization of young animals designed for studies in vivo and in situ is proposed. The method is rapid and effective and should facilitate investigation of therapeutic effects on both systemic and subcellular levels, as an advantage over the existing methods
Structure, optical, electrical and thermoelectric properties of solution-processed Li-doped NiO films grown by SILAR
The article presents a new facial synthesis of Li-doped NiO films (NiO:Li) via an easy and cost-effective method Successive Ionic Layer Adsorption and Reaction (SILAR) with the processing of the obtained NiO films in a
lithium-containing aqueous solution for their transformation after annealing into NiO:Li layers. Comparative analysis of crystal structure, optical, electrical and thermoelectric properties of the obtained NiO and NiO:Li 420-1050 nm thick films have reveiled a cubic rock-salt NiO structure, at that, NiO:Li samples are nanocrystalline single phased Li-NiO solid solutions. The fabricated NiO and NiO:Li films are p-type semiconductors with activation energy Ea = 0.1 eV and Ea = 0.25‒0.31 eV, respectively. The obtained in-plane Seebeck coefficients Z are in the range 0.20–0.33 mV/К. Notwithstanding the fact that the maximum values of the thermoelectric power factors P=2.2 μW/K2·m, are rather small, they were achieved if the hot end of the NiO:Li film was heated only to 115 °C. Thus, the produced in this work new low cost thermoelectric thin film material is suitable for a production of electrical energy for low-power devices due to absorption of low-potential heat
Functional Characterization of Lamina X Neurons in ex-Vivo Spinal Cord Preparation
Functional properties of lamina X neurons in the spinal cord remain unknown despite
the established role of this area for somatosensory integration, visceral nociception,
autonomic regulation and motoneuron output modulation. Investigations of neuronal
functioning in the lamina X have been hampered by technical challenges. Here we
introduce an ex-vivo spinal cord preparation with both dorsal and ventral roots still
attached for functional studies of the lamina X neurons and their connectivity using an
oblique LED illumination for resolved visualization of lamina X neurons in a thick tissue.
With the elaborated approach, we demonstrate electrophysiological characteristics
of lamina X neurons by their membrane properties, firing pattern discharge and
fiber innervation (either afferent or efferent). The tissue preparation has been also
probed using Ca2+ imaging with fluorescent Ca2+ dyes (membrane-impermeable or
-permeable) to demonstrate the depolarization-induced changes in intracellular calcium
concentration in lamina X neurons. Finally, we performed visualization of subpopulations
of lamina X neurons stained by retrograde labeling with aminostilbamidine dye to
identify sympathetic preganglionic and projection neurons in the lamina X. Thus, the
elaborated approach provides a reliable tool for investigation of functional properties
and connectivity in specific neuronal subpopulations, boosting research of lamina X of
the spinal cord
Maturation of neural stem cells and integration into hippocampal circuits: functional study in post-ischemia in situ
The hippocampus is the most susceptible region of the brain to ischemic lesion, with highly vulnerable pyramidal interneurons to ischemic cell death. A restricted brain neurogenesis limits a withdrawal of massive cell death after stroke that endorses cell-based therapies for neuronal replacement strategies following cerebral ischemia. Neurons differentiated from neural stem/progenitor cells (NSPCs) matured and integrated into host circuitry, improving recovery after stroke. However, how host environment regulates the NSPC behaviour in post-ischemic tissue remains unknown. Here we studied functional maturation of NSPCs in control and post-ischemic hippocampal tissue after modelling cerebral ischemia in situ. We traced maturation of electrophysiological properties and integration of the NSPC-derived neurons into the host circuits, developing appropriate activity that takes 3 weeks or less after engraftment. In the ischemic-injured tissue, the NSPC-derived neurons exhibited functional deficits and differentiation of embryonic NSPCs was boosted to glial type – oligodendrocytes and astrocytes. Our findings of the delayed neuronal maturation whilst the promoted NSPC differentiation towards glial cell type in post-ischemic conditions provide new insights into stem-cell-therapy for replacement strategies in cerebral ischemia
ВИВЧЕННЯ ДУМКИ ІНОГОРОДНІХ СТУДЕНТІВ ЩОДО ДОСТУПНОСТІ ТА ЯКОСТІ МЕДИЧНОГО ОБСЛУГОВУВАННЯ
Purpose: to identify major health problems related to the availability and quality of health care for nonresident students, find ways and solutions to these problems.
Materials and Methods. An anonymous sociological survey by questioning 100 nonresident students of III-VI years of study in Danylo Halytskyi Lviv National Medical University was conducted.
Results. Medical care for nonresident students causes many problems: preference for deterioration of well-being not for professional help of doctors, but for other alternative options (colleagues’ advice, relatives, acquaintances, searching for information on the Internet), unfavourable attitude of non-resident students to medical advice, unwillingness to consult them or provide other types of medical care.
It was found out that a greater number of nonresident students (57±5.0) % in case of deterioration in their well-being appeal to their relatives for help, (30±4.6) % search for similar symptoms on the Internet, which leads to the occurrence of complications. (81±3.9) % of nonresident students signed a declaration at the place of residence before entering an educational institution, which can cause difficulties when they need to obtain medical care because of their distant location. Only (42±4.9) % of respondents appeal to medical institutions for the prevention of diseases, periodic examination, which leads to the identification only later stages of diseases, sometimes the terminal ones. To improve the medical care of non-resident students, it is necessary to carry out sanitary and educational work, weeks of prevention of the most common and dangerous diseases in educational institutions.
Conclusions. Propaganda of consulting the general practitioners in case of deterioration of well-being will help to make the health of nonresident students better, reduce the morbidity among them.Мета: виявити основні проблеми у сфері охорони здоров’я, що стосуються доступності та якості медичного обслуговування іногородніх студентів, пошук методів та способів вирішення цих проблем.
Матеріали і методи. Проведено анонімне соціологічне опитування методом анкетування 100 іногородніх студентів ІІІ–VІ курсів Львівського національного медичного університету імені Данила Галицького.
Результати. Медичне обслуговування іногородніх студентів зумовлює багато проблем: віддають перевагу при погіршенні самопочуття альтернативним варіантам допомоги (поради колег, родичів, знайомих, пошук інформації в мережі «Інтернет»), а не професійній допомозі лікарів; неприязне ставлення з боку медичного персоналу до іногородніх студентів; небажання консультувати їх чи надавати інші види медичної допомоги.
Виявлено, що більшість іногородніх студентів (57,0±5,0) % у разі погіршення самопочуття звертається за медичною допомогою до родичів, (30,0±4,6) % – шукають аналогічні симптоми захворювання в мережі «Інтернет», що призводить до виникнення ускладнень. Більшість (81,0±3,9) % іногородніх студентів підписала декларацію за місцем проживання ще до вступу в навчальний заклад, це може зумовлювати труднощі при отриманні медичної допомоги через віддалене їх розташування. Тільки (42,0±4,9) % опитаних звертаються у лікувально-профілактичні заклади з метою профілактики захворювань, періодичного обстеження, що призводить до виявлення хвороб на пізніх термінах, іноді вже у термінальній стадії. Для удосконалення медичного обслуговування іногородніх студентів необхідно проводити санітарно-просвітню роботу, тижні профілактики найбільш поширених та небезпечних захворювань у навчальних закладах
АНТИОТРАЖАЮЩИЕ ПОКРЫТИЯ ИЗ ЭЛЕКТРООСАЖДЕННЫХ МАССИВОВ ОКСИДА ЦИНКА ДЛЯ СОЛНЕЧНЫХ ЭЛЕМЕНТОВ
Surfaces of current photovoltaic devices are characterized by a high refractive index, so they tend to significant reflection of light. This explains the need for an antireflective coating (AR). In this paper, for the first time we demonstrate the possibility of creating the AR in the form of nano-scale zinc oxide array with a parabolic profile by its pulse electrodeposition from aqueous electrolytes. The study of the influence of the zinc oxide deposition mode on their optical properties such as transparency and reflection in the visible region at different angles of radiation, the optical band gap and Urbach energy were performed using a spectrophotometer SF-2000 equipped with specular and diffuse reflection attachment SFO-2000. Structural characteristics, namely, lattice parameters, microstrains, residual stress and texture were analyzed by X-ray diffractometry. Morphology of the grown arrays was investigated by intermittent-contact atomic force microscopy (AFM) using a NanoLaboratory Ntegra Prima NT-MDT setup. Optimization of the pulse electrodeposition mode allowed to adjust the size of parabolic nipples and thus to create AR moth-eye structure based on the electrodeposited zinc oxide arrays, which is suitable for use in photovoltaic devices. Bibliography. 7, Table. 1, Fig. 5.Поверхности современных фотоэлектрических преобразователей характеризуются довольно высоким коэффициентом преломления, поэтому им свойственно значительное отражение света, для устранения которого прибегают к нанесению антиотражающих покрытий (АП). В данной работе впервые показана возможность создания АП в виде наноразмерных массивов оксида цинка с параболическим профилем методом импульсного электрохимического осаждения из водных электролитов. Исследование влияния режимов осаждения массивов оксида цинка на такие его оптические свойства как прозрачность и отражение в видимой области при различных углах облучения, на оптическую ширину запрещенной зоны и на энергию Урбаха выполняли с помощью спектрофотометра СФ-2000, оснащенного приставкой зеркального и диффузного отражения СФО-2000. Структурные характеристики, а именно, параметры кристаллической решетки, микронапряжения, остаточные напряжения и текстура анализировались по данным рентген-дифрактометрических исследований. Морфологию выращиваемых массивовисследовали полуконтактным методом атомной силовой микроскопии (АСМ) на установке «НаноЛаборатория Нтегра Прима NT-MDT». Оптимизация режимов импульсного электроосаждения позволила скорректировать размеры параболических нановыступов и таким образом обеспечить создание на основе электроосажденных массивов оксида цинка пригодного для использования в фотоэлектрических преобразователях АП с эффектом глаза ночной бабочки. Библ. 7, табл. 1, рис. 5.Поверхні сучасних фотоелектричних перетворювачів характеризуються досить високим коефіцієнтом заломлення, тому їм властиво значне відображення світла, для усунення якого вдаються до нанесення антивідбиваючих покриттів (АП). У даній роботі вперше показана можливість створення АП у вигляді нанорозмірних масивів оксиду цинку з параболічним профілем методом імпульсного електрохімічного осадження з водних електролітів. Дослідження впливу режимів осадження масивів оксиду цинку на такі його оптичні властивості як прозорість і відображення у видимій області при різних кутах опромінення, на оптичну ширину забороненої зони та на енергію Урбаха виконували за допомогою спектрофотометра СФ-2000, оснащеного приставкою дзеркального і дифузного віддзеркалення СФО-2000 . Структурні характеристики, а саме, параметри кристалічної решітки, мікронапруги, залишкові напруги і текстура аналізувалися за даними рентген-дифрактометричних досліджень. Морфологію вирощуваних масивів досліджували напівконтактним методом атомної силової мікроскопії (АСМ) на установці «НаноЛабораторія Нтегра Прима NT-MDT». Оптимізація режимів імпульсного електроосадження дозволила скорегувати розміри параболічних нановиступов і таким чином забезпечити створення на основі електроосадженних масивів оксиду цинку придатного для використання в фотоелектричних перетворювачах АП з ефектом ока нічного метелика. Бібл. 7, табл. 1, мал. 5
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