Wyniki wyszukiwania - Biblioteka Nauki

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Transgenic mice with dysregulated Ca2plus homeostasis in neurons as a model of age-induced neurodegeneration

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Majewski L. , Kuznicki J.

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nr Suppl.1

EN

Altered Ca2+ homeostasis has recently emerged as one of the early events responsible for Alzheimer’s disease (AD). Disturbances in Ca2+ signaling are found before any obvious extracellular Aβ pathology in patients with sporadic AD and it has been shown frequently, that Ca2+ dysfunction augments Aβ formation and Tau hyperphosphorylation. It is suggested, that brain ageing is a result of a subtle, but long-lasting dysregulation of Ca2+ homeostasis in neurons, which may explain that age is the major risk factor in AD. Our group showed that the intracellular Ca2+ level in resting neurons can be modulated by overexpression of STIM proteins. These proteins sense calcium level in ER and are involved in the Store Operated Calcium Entry (SOCE). The objective of our project is to understand how elevated basal Ca2+ level in neurons contributes to neurodegeneration. To achieve this goal constructs for STIM proteins and ORAI1 Ca2+ channels were created and procedures of transgenesis were completed to generate transgenic mice. The animals are now being tested for the transgenes. We will next analyze Ca2+ homeostasis in neurons of the transgenic mice. If they have expected phenotype, other properties will be monitored including behavior and susceptibility to neurodegeneration.

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O rolnictwie i ekologii slow kilka

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Majewski L.

Zdrowa Żywność - Zdrowy Styl Życia

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1992

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nr 3

8-9

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Experimental and Numerical Investigations of Stability of Mobile Crane Model

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Janusz J. , Kłosiński J. , Majewski L. , Sidzina M.

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tom Vol. 29, No. 2

69-80

EN

In the paper, based upon the physical model of a mobile crane, its mathematical model has been prepared for the determination of reaction forces in points of contact between the chassis and the ground. The values of these forces calculated by means of the proposed model were compared with those obtained from experimental verification. The comparison showed slight differences between them. The presented crane model can be utilized in stability analysis.

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Myosin VI is associated with secretory granules and is present in the nucleus in adrenal medulla chromaffin cells

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Majewski L. , Sobczak M. , Redowicz M. J.

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nr 1

109-114

EN

Myosin VI (MVI) is the only known myosin walking towards minus end of actin filaments. Here, MVI, but not myosins IB or IIB, was detected in chromaffin granules isolated from bovine medulla and found to be tightly associated with the granule apical surface. MVI also localized to secretory granules within rat pheochromocytoma PC12 cells as well as to the Golgi apparatus, endoplasmic reticulum and clathrin-coated pits. Notably, it was also found in the nucleus. RT-PCR revealed that MVI splice variants with a large insert (LI), characteristic of polarized cells, were barely detectable in PC12 cells, whereas variants with a small insert (SI) were the major isoforms. The presented data indicate that MVI in adrenal medulla cells is engaged in secretory vesicle trafficking within the cytoplasm and possibly also involved in transport within the nucleus.

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Miozyny w jądrze komórkowym

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Sobczak M. , Majewski L. , Redowicz M. J.

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nr 2

6

Investigation of Ca2plus homeostasis and behavioral changes in transgenic mice overexpressing key store-operated calcium entry proteins

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Maciag F. , Majewski L. , Boguszewski P. M. , Kuznicki J.

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nr Suppl.1

EN

INTRODUCTION: Store-operated calcium entry (SOCE) is the major Ca2+ influx pathway in non-excitable cells. However, recent studies suggest its important roles in neurons. In SOCE, the depletion of Ca2+ from the endoplasmic reticulum (ER) causes an influx of Ca2+ from the extracellular space to refill the intracellular Ca2+ stores. STIMs are Ca2+ ER sensors that mediate SOCE by interacting with the ion channels in the cell membrane – ORAIs. Using transgenic mice with neuronal overexpression of STIMs and/or ORAIs, we investigate their role in neural function. Recently, we showed electrophysiological changes in hippocampi from female mice overexpressing ORAI1. Earlier studies from our group revealed increased cytoplasmic Ca2+ levels in cultured neurons overexpressing both ORAI1 and STIM2. Currently, we are extending these studies with the use of double transgenic STIM2/ORAI1 mice. AIM(S): To investigate the role of SOCE proteins in neurons, and the effect of STIM2 and ORAI1 overexpression on Ca2+ homeostasis, synaptic functions, and behavior. METHOD(S): We use transgenic mice that overexpress STIM and/or ORAI proteins in brain neurons. For studying Ca2+ homeostasis, we stain hippocampal slices with Fura‑2 AM probe. To assess locomotor functions and cognitive abilities of these mice, behavioral tests are utilized. Synaptic transmission and plasticity phenomena are investigated by electrophysiological recordings from hippocampal slices. RESULTS: We have recently observed spontaneous seizure-like events in aged female mice overexpressing ORAI1. These observations correlated with changes in the response of hippocampal slices to pro-epileptic drugs. Currently, we are focusing our analyses on the double transgenic STIM2/ORAI1 mouse line. CONCLUSIONS: Our previous data support the view that SOCE proteins play an important role in neurons. Currently, we aim to elucidate the involvement of STIM2 and ORAI1 proteins in neural function. FINANCIAL SUPPORT: Maestro to JK from NCN (2011/02/A/NZ3/00144).

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Badania eksperymentalne układu regulacji ruchów roboczych w modelu żurawia teleskopowego

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Janusz J. , Kłosiński J. , Majewski L. , Sidzina M.

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tom R. 45, nr 2-3

50-52

PL

W pracy zaprezentowano przyczyny budowy a następnie modernizacji stanowiska badawczo-pomiarowego służącego do weryfikacji eksperymentalnej badań numerycznych układów regulacji ruchów roboczych żurawia teleskopowego. Opisano zakres modernizacji oraz przedstawiono wybrane wyniki badań eksperymantalnych ruchu obrotowego i zmiany wysięgu modelu żurawia.

EN

The numerical investigations of the mobile cranes' mathematical models have been carried out for several years for the purpose of selection of strategy used for controlling the working notions o the crane. The needed strategy should ensuretransport of a payload to an assumed point with simultaneous fulfilling the additional conditions such as: minimisation of the payload swings after stop of motion or/and the payload stop in definite point. These investigations let for formulation of the conditions and the rules enabiling creation of the needed control strategy. In the next stage, the necessity arose to achieve the experimental verification of the obtained results of numerical investigations.

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Pomiary drgań małej sprężarki tłokowej

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Kłosiński J. , Majewski L. , Janusz J.

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tom R. 53, nr 12

27-29

PL

W pracy podjęto próbę poprzez wykonanie badań doświadczalnych zmniejszenia drgań i hałasu, małej sprężarki tłokowej jednocylindrowej pracujacej w pobliżu pomieszczenia laboratoryjnego. Praca zawiera wyniki badań eksperymentalnych drgań sprężarki w miejscu jej instalacji z izolacją od podłoża i bez izolacji oraz analizę otrzymanych wyników. Do pomiarów drgań wykorzystano aparaturę pomiarową wraz z wyposażeniem opisaną w [1, 2]. Pomiary poziomu dźwięku zostały przeprowadzone za pomocą przenośnego miernika [3].

EN

In the paper, an attempt was made to reduce vibrations and emitted noise by a small one-piston air compressor working in the neighborhood of a laboratory room. The relevant measurements in service conditions were performed. The results of the experimental investigations - performed in service condition - are presented. The versions without and with the isolation pads from the ground were taken into account. The analysis of the outcomes is also presented. the measurements if vibrations were made by means of the equipment described in [1,2]. The sound measurements were performed by means of portable equipment described in [3].

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Opracowanie technologii wytwarzania hybrydowego materiału termoizolacyjnego będącego kompozytem styropianu i włókien pochodzących z recyklingu

71%

Danecki L. , Czapiewski G. , Wardzińska E. , Szczepaniak B. , Majewski L.

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2016

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tom R. 21, nr 3

44--47

PL

W artykule przedstawiono etapy wytwarzania hybrydowego materiału termoizolacyjnego składającego się ze styropianu i włókien pochodzących z recyklingu. Omówiono dobranie odpowiedniej granulacji celulozy, wybór dodatku uniepalniającego, środka grzybobójczego oraz czynnika łączącego składniki międzyfazy z EPS. Podkreślono elementy wpływające na innowacyjność tego produktu.

EN

The article presents the production stages for a hybrid thermal insulation material, composed of expanded polystyrene foam and recycled fibres. It discusses selection of the right cellulose grain size, selection of flame retardant, anti-fungal agent and binding agent for binding the core layers with EPS. Special emphasis was on the elements affecting the innovative quality of the product.