Методы улучшения метрологических характеристик лазерных измерителей диаметра

В данной работе рассмотрены методы и средства контроля диаметра кабельных изделий и на основе которых выявлены способы улучшение метрологических характеристик лазерных измерителей диаметра.In this article, methods and means for controlling the diameter of cable products are considered and on the basis of which methods for improving the metrological characteristics of laser diameter meters are revealed

Перспективы развития фундаментальных наук: сборник научных трудов XI Международной конференция студентов и молодых ученых, г. Томск, 22-25 апреля 2014 г.

Сборник содержит труды участников XI Международной конференции студентов и молодых учёных "Перспективы развития фундаментальных наук". Включает доклады студентов и молодых ученых, представленные на секциях "физика", "химия", "математика", "технология", наноматериалы и нанотехнологии», "IT-технологии и электроника". В рамках секций представлены доклады студентов представленные для соискания стипендий по программе У.М.Н.И.К. Сборник представляет интерес для студентов, аспирантов, молодых ученых, преподавателей в области естественных наук и высшей математик

An ex vivo continuous passive motion model in a porcine knee for assessing primary stability of cell-free collagen gel plugs

<p>Abstract</p> <p>Background</p> <p>Primary stability of cartilage repair constructs is of the utmost importance in the clinical setting but few continuous passive motion (CPM) models are available. Our study aimed to establish a novel ex vivo CPM animal model and to evaluate the required motion cycles for testing the mechanical properties of a new cell-free collagen type I gel plug (CaReS^®-1S).</p> <p>Methods</p> <p>A novel ex vivo CPM device was developed. Full-thickness cartilage defects (11 mm diameter by 6 mm deep) were created on the medial femoral condyle of porcine knee specimens. CaReS^®-1S was implanted in 16 animals and each knee underwent continuous passive motion. After 0, 2000, 4000, 6000, and 8000 motions, standardized digital pictures of the grafts were taken, focusing on the worn surfaces. The percentage of worn surface on the total CaReS^®-1S surface was evaluated with image processing software.</p> <p>Results</p> <p>Significant differences in the worn surface were recorded between 0 and 2000 motion cycles (p < 0.0001). After 2000 motion cycles, there was no significant difference. No total delamination of CaReS^®-1S with an empty defect site was recorded.</p> <p>Conclusion</p> <p>The ex vivo CPM animal model is appropriate in investigating CaReS^®-1S durability under continuous passive motion. 2000 motion cycles appear adequate to assess the primary stability of type I collagen gels used to repair focal chondral defects.</p

Evidence for Regulated Interleukin-4 Expression in Chondrocyte-Scaffolds under In Vitro Inflammatory Conditions

OBJECTIVE: To elucidate the anti-inflammatory and anabolic effects of regulated expression of IL-4 in chondrocyte-scaffolds under in vitro inflammatory conditions. METHODS: Mature articular chondrocytes from dogs (n = 3) were conditioned through transient transfection using pcDNA3.1.cIL-4 (constitutive) or pCOX-2.cIL-4 (cytokine-responsive) plasmids. Conditioned cells were seeded in alginate microspheres and rat-tail collagen type I matrix (CaReS®) to generate two types of tissue-engineered 3-dimensional scaffolds. Inflammatory arthritis was simulated in the packed chondrocytes through exogenous addition of recombinant canine (rc) IL-1β (100 ng/ml) plus rcTNFα (50 ng/ml) in culture media for 96 hours. Harvested cells and culture media were analyzed by various assays to monitor the anti-inflammatory and regenerative (anabolic) properties of cIL-4. RESULTS: cIL-4 was expressed from COX-2 promoter exclusively on the addition of rcIL-1β and rcTNFα while its expression from CMV promoter was constitutive. The expressed cIL-4 downregulated the mRNA expression of IL-1β, TNFα, IL-6, iNOS and COX-2 in the cells and inhibited the production of NO and PGE(2) in culture media. At the same time, it up-regulated the expression of IGF-1, IL-1ra, COL2a1 and aggrecan in conditioned chondrocytes in both scaffolds along with a diminished release of total collagen and sGAG into the culture media. An increased amount of cIL-4 protein was detected both in chondrocyte cell lysate and in concentrated culture media. Neutralizing anti-cIL-4 antibody assay confirmed that the anti-inflammatory and regenerative effects seen are exclusively driven by cIL-4. There was a restricted expression of IL-4 under COX-2 promoter possibly due to negative feedback loop while it was over-expressed under CMV promoter (undesirable). Furthermore, the anti-inflammatory /anabolic outcomes from both scaffolds were reproducible and the therapeutic effects of cIL-4 were both scaffold- and promoter-independent. CONCLUSIONS: Regulated expression of therapeutic candidate gene(s) coupled with suitable scaffold(s) could potentially serve as a useful tissue-engineering tool to devise future treatment strategies for osteoarthritis