Заболевание тазобедренного сустава у детей с наследственной предрасположенностью: концептуальная модель

На основе принципов интегративной медицины, системного подхода с использованием концептуально−логического моделирования разработана единая система представлений о заболеваниях тазобедренного сустава у детей с наследственной предрасположенностью. Показано, что предлагаемый интегративный подход может служить основой для разработки диагностических и прогностических критериев развития суставов и проведения патогенетического хирургического лечения, направленного на ликвидацию или существенное снижение частоты формирования диспластического коксартроза.Based on the principles of integrative medicine, systemic approach with the use of concept of logical modelling, a uniform system of concepts about the diseases of the hip joint in children with hereditary susceptibility was worked out. It was shown that the suggested integrative approach can be used for working out diagnostic and prognostic criteria of joint development and performing pathogenetic surgery aimed at elimination or reduction in the frequency of forming dysplastic coxarthrosis

Alcohol-derived DNA crosslinks are repaired by two distinct mechanisms

Acetaldehyde is a highly reactive, DNA-damaging metabolite that is produced upon alcohol consumption1. Impaired detoxification of acetaldehyde is common in the Asian population, and is associated with alcohol-related cancers1,2. Cells are protected against acetaldehyde-induced damage by DNA crosslink repair, which when impaired causes Fanconi anaemia (FA), a disease resulting in failure to produce blood cells and a predisposition to cancer3,4. The combined inactivation of acetaldehyde detoxification and the FA pathway induces mutation, accelerates malignancies and causes the rapid attrition of blood stem cells5,6,7. However, the nature of the DNA damage induced by acetaldehyde and how this is repaired remains a key question. Here we generate acetaldehyde-induced DNA interstrand crosslinks and determine their repair mechanism in Xenopus egg extracts. We find that two replication-coupled pathways repair these lesions. The first is the FA pathway, which operates using excision—analogous to the mechanism used to repair the interstrand crosslinks caused by the chemotherapeutic agent cisplatin. However, the repair of acetaldehyde-induced crosslinks results in increased mutation frequency and an altered mutational spectrum compared with the repair of cisplatin-induced crosslinks. The second repair mechanism requires replication fork convergence, but does not involve DNA incisions—instead the acetaldehyde crosslink itself is broken. The Y-family DNA polymerase REV1 completes repair of the crosslink, culminating in a distinct mutational spectrum. These results define the repair pathways of DNA interstrand crosslinks caused by an endogenous and alcohol-derived metabolite, and identify an excision-independent mechanism

Attenuation effects on laser-based nitric oxide diagnostics in a heavy-duty diesel engine

A number of laser diagnostic techniques enabling a correction for laser intensity and detection efficiency of the raw NO-LIF data is presented. Laser beam transmission measurements at 226 nm, with the laser beam parallel to the cylinder axis, show that ∼ 20° aTDC the transmission is typically 1%; it increases to 50-80% later in the stroke, depending on engine load. Since absorption by CO2 shows a strong wavelength dependence (increasing absorption for shorter wavelengths), the attenuation for 237 nm being equal to that for 226 nm suggests that CO2 does not play a dominant role in the laser beam transmission. Since the overall laser beam transmission measurements show considerable attenuation, the bidirectional results suggest that most of the laser beam extinction occurs outside the field of view, e.g. in the piston bowl. Not only the laser beam, but also NO fluorescence is attenuated. Detection of NO LIF through a spectrograph allows quantitative comparison of the intensities of the observed fluorescence bands at 237, 248, and 259 nm. This is an abstract of a paper presented at the 30th International Symposium on Combustion (Chicago, IL 7/25-30/2004)

Plastic zonder olie : lesmodule voor nieuwe scheikunde

Lesmodule voor nieuwe scheikunde voor leerlingen uit 5 en 6 vwo. Bioplastics worden gemaakt uit natuurlijke grondstoffen. Als ze de synthetische plastics vervangen kan de voorraad aardolie ontzien worden. Omdat veel bioplastics afbreekbaar zijn, kan ook de berg plastic afval krimpen. Maar zijn bioplastics in staat om ons de reguliere plastics te doen vergeten? Hoe maken we bioplastics met dezelfde veelzijdige eigenschappen als plastic? Waar komen de uiteenlopende eigenschappen van plastics eigenlijk vandaan? De lesmodule ‘Plastic zonder Olie’ gaat op deze en meerdere vragen in. Naast de practica waarin de leerlingen bioplastics gaan maken ligt het zwaartepunt van de module bij een multidisciplinaire slotopdracht