Ultra-Fast Versus Sustained Cholinergic Transmission: A Variety of Different Mechanisms

Although synaptic transmission was assumed to use the same mechanisms in the case of different synapses of the central and peripheral nervous system, recent research revealed a great variety of different processes. Time might be a crucial factor to be considered in this diversity. It is recalled that the speed of a chemical reaction is inversely related to affinity. "Time is gained at the expense of sensitivity” as noticed by Bernard Katz (1989). Therefore, synaptic transmission will occur at a high speed only if it is supported by low affinity reactions. In the present work, we compare two examples of ultra-rapid transmission (the Torpedo nerve electroplaque synapse and the rat hippocampus mossy fiber/CA3 synapses), with a cholinergic process operating with high affinity but at a low speed: the release of glutamate elicited by nicotine from mossy fibers of the rat hippocampu

Structural integrity of a wind loaded cylindrical steel shell structure

The structural integrity and life assessment can be considered as a mandatory request in the civil engineering designing and manufacturing process. The paper is presenting the procedure for determination of crack acceptability based on fracture toughness with failure assessment methods (FAD-1 and FAD-2) which is applied to a cylindrical steel shell structure with welded joints which is having the wind as a main load. The assessment is using BS7910/2013. Thus were assessed common types of flaws met at steel shell cylindrical structure elements using failure assessment diagrams - level 1 - FAD-1. The results are presenting the acceptability level for each type of flaw with comparative graphs, determining also the critical dimension of the flaw. For each flaw was calculated the failure assessment diagram (FAD-2). Different comparisons between group of flaws were done, revealing the critical crack like flaw. Also the critical value of flaw dimensions were calculated for each flaw type. The methodology establishes clear rules for assessment of structural elements with cracks, determining the initial flaws, assessed flaws and critical values of the cracks. Based on the detailed procedures described in the paper, on conclusions to the assessment done on each type of flaw, the assessment methods can be applied very easy in current design practice with different material characteristic

L'impact des exosomes sur la viabilité des lymphocytes T CD4⁺ dans le contexte de l'infection au VIH-1

Les cellules dendritiques (CDs) sont connues comme étant les cellules sentinelles du système immunitaire. En effet, par leur capacité à capturer et à présenter les antigènes du soi ou étrangers, elles ont la propriété de moduler la réponse immunitaire innée et acquise. Toutefois, elles sont aussi connues pour libérer des vésicules dans le milieu extra cellulaire, dont entre autres les exosomes. Les exosomes sont des microvésicules de 30 - 100 nm jouant un rôle important au sein de l'intercommunication cellulaire. L'état d'activation des CDs influence drastiquement la composition et le rôle des exosomes. D'après des résultats préliminaires obtenus au sein du laboratoire, nous avons observé que les CDs ainsi que les lymphocytes T CD4⁺ (LTCD4) mis en contact avec le virus de l'immunodéficience humaine 1 (VIH-1) pouvaient libérer de plus grandes quantités d'exosomes. De plus, une préparation virale dépourvue en exosomes augmente la viabilité des LTCD4. Enfin, une analyse protéomique d'échantillons purifiés d'exosomes sur gradient d'optiprep a révélé un contenu enrichi en protéines jouant un rôle important dans la survie cellulaire : telle que, les protéines Death-Associated-Protein 3 (DAP3) et Apoptotic peptidase activating factor 1 (APAF-1). Ces deux protéines sont connues pour participer à la voie d'activation des caspases entraînant l'apoptose. De ce fait, la présence de ces protéines dans les exosomes pourrait contribuer à l'élimination des LTCD4. En utilisant l'immunobuvardage nous avons mis en place le protocole et confirmé les résultats de l'analyse protéomique dans les cellules HEK-293T. Cependant, seulement la protéine DAP3 est détectée dans les exosomes isolés à partir de CDs mises en contact avec du virus atténué. De plus, il s'avère qu'une infection productive est nécessaire pour déceler la protéine. Finalement, en utilisant des ARN antisens anti-DAP3, nous avons favorisé la diminution de l'expression de la protéine DAP3. Ainsi, nous pouvons moduler l'expression de la protéine dans les CDs afin de vérifier éventuellement son impact sur la viabilité des LTCD4. En conclusion, tous les outils sont mis en place afin d'assurer la suite du projet qui pourrait nous permettre de mieux comprendre la depletion des LTCD4 lors de la primo-infection

Refurbishment of Existing Steel Structures – an Actual Problem

Many steel structures erected at the end of the XIX and begin ofthe XX-centuries still are in function. Some of these structures,particularly bridges, have already achieved an age of ninety,hundred or even more years and are still in operation afterdamages, several phases of repair and strengthening. Replacementwith new structures raises financial, technical and politicalproblems. The budget of the administration gets smaller.Information about the safety of the structure, the remaining life,the costs for maintenance etc. are important. Nobody will takethe responsibility for failure of a structure as a result of budgetrestriction. The aim of the paper is to emphasize the importanceof refurbishment of existing steel structures, part of sustainabledevelopment

Probabilistic analysis of bearing capacity of piles with variable parameters in cpt test and calculation according to the requirements

A probabilistic concept for determining pile bearing capacity is presented, taking into account the variability of CPT test parameters and methodology of calculation according to the requirements of Eurocode 7 (EN 1997-1: 2004). Based on a single initial (real) CPT test, a larger number of generated (simulation) CPT tests are introduced drawn from solutions of statistics and probability theory. Research has found that the best solutions are achieved using the DA 2 design approach for n(CPT) > 10 tests. Taking into account the deterministic and probabilistic approach in the analysis of pile bearing capacity, it is found that for the DA 2 design approach, the ratio of pile bearing capacity obtained from simulation and the capacity as determined through three methods (Mazurkiewicz, Van der Veen and hyperbolic approximation) is Rcd, /Pu = 1.148. Using the reliability index, the following values of partial resistance factors are obtained: λ, s /P 1.1, λ, b /P 1.1, which also points to the DA 2 design approach

The technologies and the potential of recycling in Romania

Ця стаття представляє загальний огляд минулого і цієї позиції провідних підприємств щодо природоохоронного законодавства і його впливу. Провідні підприємства досягли режиму роботи, який розглядався б недосяжним десять років тому. Проте індустрія вміла переживати етап постійно зростаючих вимог виробників, і користувачі повинні були оцінити їх майбутні позиції, так як значення вартості законів навколишнього середовища мали істотний вплив на їх суть. Потреба знати існуюче і запропоноване законодавство має першорядну важливість.This paper presents a general overview of the past and actual position of the lead industry in relation with the environmental legislation and its impact. The lead industry has watched environmental lead levels being steadily reduced down to levels that, ten years ago, would have been considered unachievable. Nevertheless, the industry’ has managed to survive the effect of the ever-increasing demands of producers and users have had to assess their future positions, as the cost implications of environmental laws have had a significant impact on their bottom lines. The need to be aware of the existence of new and proposed legislation is of paramount importance, as the thereat from the vast array of EEC Legislation is ever apparent

Maximisation of extraction efficiencyin copper metallurgy

Мідна виробництво складається з двох основних стадій: плавлення матеріалу і перетворення, що супроводжуються великими втратами міді. Окремі дослідження збільшення продуктивності, на цих двох стадіях не дали добрих результатів до теперішнього часу. Ця робота пропонує новий підхід до проблеми підвищення продуктивності виробництва міді. Процес розглядається як єдиний. Використовуються методи математичного анапізу і математичних моделей, спеціально розроблених для цієї мети.The copper production is made in two essential stages: melt for matte and convertizing, confronted with big losses of copper. The separate onset of efficiency maximisation at those two work staves doesn't have lead until present at good results. This paper proposes a new approach of this problem: maximisation of efficiency with treating of melt for matte and convertizing as a unitary process, through methods of mathematical analyse, being necessary the utilisation of mathematical models especially elaborated for this purpose