474 research outputs found

    Automated optimal design of wells for electromagnetic cell stimulation

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    In the paper, a device for in vitro electromagnetic stimulation of cells at low frequency (75 Hz) is considered. In particular, shape and position of a well-plate are identified in order to obtain a homogeneous stimulation and to maximize the space allotted to cell culture. To this end, the BiMO and micro-BiMO optimization algorithms, which have shown good performances in multi-objective optimization of electromagnetic devices, are applied

    Influence of Hydrogen and Low Temperature on Pipeline Steels Mechanical Behaviour

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    Abstract In the presence of H2S, metallic materials, such as carbon and low alloy steels, may suffer hydrogen damage and hydrogen embrittlement. Gas transporting pipes in low temperature environment, during the shutdown and the subsequent re-starting operations, are exposed to very low temperatures (T=-40 °C). In the presence of high H2S content in the gas, the risk of brittle failure can be increased due to the effect of hydrogen on steel toughness. In this paper the influence of hydrogen and low temperature on mechanical properties of two pipeline materials, F22 low alloy and X65 micro-alloyed steels, is studied. Steels have been hydrogen charged by means of an electrochemical method: diffusible hydrogen content of steels is in the range 0.6 to 2 ppm. Charpy and J-R curves tests were carried out in the range from room temperature to T=-120 °C. Hydrogen affects mechanical properties of the tested materials, mainly reducing fracture toughness in J integral tests, while little influence has been observed in CV tests. Fracture surface examination confirms the results of mechanical testing

    Chronic cypermethrin exposure alters mouse embryonic stem cell growth kinetics, induces Phase II detoxification response and affects pluripotency and differentiation gene expression

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    Worldwide uncontrolled use of synthetic pyrethroids contaminates water and soil leading to health hazards. Cypermethrin (CYP), the most used pyrethroid, induces detrimental effects on adults and embryos at different stages of development of several vertebrate species. In Mammals, CYP-induced alterations have been previously described in adult somatic cells and in post-implantation embryos. It remains unknown whether CYP has effects during pre-implantation development. Studies to access pre-implantation embryo toxicity are complicated by the restricted number of blastocysts that may be obtained, either in vivo or in vitro. Embryonic stem cells (ESCs) are an in vitro model study that overcomes these limitations, as millions of pluripotent cells are available to the analysis. Also, ESCs maintain the same pluripotency characteristics and differentiation capacity of the inner cell mass (ICM) present in the blastocyst, from which they derive. In this work, using mouse R1 ESCs, we studied CYP-induced cell death, ROS production, the activation of oxidative stress-related and detoxification responses and the population growth kinetics following 72 h exposure at the 0.3 mM LD50 dose. Also, the expression levels of pluripotency genes in exposed ESCs and of markers of the three germ layers after their differentiation into embryoid bodies (EBs) were determined. Two apoptotic waves were observed at 12-24 h and at 72 h. The increase of ROS production, at 24 h until the end of the culture period, was accompanied by the induction, at 48 h, of redox-related Cat, Sod1, Sod2, Gpx1 and Gpx4 genes. Up-regulation of Cyp1b1, but not of Cyp1a1, phase I gene was detected at 72 h and induction of Nqo1, Gsta1 and Ugt1a6 phase II genes began at 24 h exposure. The results show that exposed R1 ESCs activate oxidative stress-related and detoxification responses, although not sufficient, during the culture period tested, to warrant recovery of the growth rate observed in untreated cells. Also, CYP exposure altered the expression of Oct-4 and Nanog pluripotency genes in ESCs and, when differentiated into EBs, the expression of Fgf5, Brachyury and Foxa2, early markers of the ectoderm, mesoderm and endoderm germ layers, respectively. NIH/3T3 cells, a differentiated cell line of embryonic origin, were used for comparison

    Serum Squamous Cell Carcinoma Antigen-Immunoglobulin M complex levels predict survival in patients with cirrhosis

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    Complications of chronic liver diseases - particularly hepatocellular carcinoma (HCC) - are a major cause of mortality worldwide. Several studies have shown that high or increasing levels of serum Squamous Cell Carcinoma Antigen-Immunoglobulin M complex (SCCA-IgM) are associated with development of HCC in patients with advanced liver disease and worse survival in patients with liver cancer. The aim of the present study was to assess, in patients with advanced liver disease, differences in long-term clinical outcomes in relation to baseline levels of serum SCCA-IgM. Ninety one consecutive outpatients with liver cirrhosis of different etiologies, without hepatocellular carcinoma at presentation, were enrolled from April 2007 to October 2012 in a prospective study. For a median time of 127 months, patients were bi-annually re-evaluated. SCCA-IgM complex levels were determined with a validated enzyme-linked immunosorbent assay. The results provided evidence that serum SCCA-IgM is a predictor of overall survival. The best cut-off to discriminate both HCC-free and overall survival rates was 120\u2009AU/mL. Patients with baseline values higher than this threshold showed a substantial increase in both HCC incidence rate and all-cause mortality rate. In conclusion, a single measurement of serum SCCA-IgM helps to identify those patients with liver cirrhosis with increased risks of HCC development and mortality

    An active feedback recovery technique from disruption events induced by m=2 n=1 tearing modes in ohmically heated tokamak plasmas

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    We present experimental results of magnetic feedback control on the m=2, n=1 tearing mode in RFX-mod operated as a circular ohmically heated tokamak. The feedback suppression of the non-resonant m=2, n=1 Resistive Wall Mode (RWM) in q(a)<2 plasmas is a well-established result of RFX-mod. The control of the tearing counterpart, which develops in q(a)>2 equilibrium, is instead a more difficult issue. In fact, the disruption induced by a growing amplitude m=2, n=1 tearing mode can be prevented by feedback only when the resonant surface q=2 is close to the plasma edge, namely 2<q(a)<2.5, and the electron density does not exceed approximately half of the Greenwald limit. A combined technique of tearing mode and q(a) control has been therefore developed to recover the discharge from the most critical conditions: the potentially disruptive tearing mode is converted into the relatively benign RWM by suddenly decreasing q(a) below 2. The experiments demonstrate the concept with 100% of successful cases. The q(a) control has been performed through the plasma current, given the capability of the toroidal loop-voltage power supply of RFX-mod. We also propose a path for controlling q(a) by acting on the plasma shape, which could be applied to medium size elongated tokamaks

    The effects of combinatorial chemistry and technologies on drug discovery and biotechnology : A mini review

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    The review will focus on the aspects of combinatorial chemistry and technologies that are more relevant in the modern pharmaceutical process. An historical, critical introduction is followed by three chapters, dealing with the use of combinatorial chemistry/high throughput synthesis in medicinal chemistry; the rational design of combinatorial libraries using computer-assisted combinatorial drug design; and the use of combinatorial technologies in biotechnology. The impact of "combinatorial thinking" in drug discovery in general, and in the examples reported in details, is critically discussed. Finally, an expert opinion on current and future trends in combinatorial chemistry and combinatorial technologies is provided

    An in vivo Comparison Study Between Strontium Nanoparticles and rhBMP2

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    The osteoinductive property of strontium was repeatedly proven in the last decades. Compelling in vitro data demonstrated that strontium hydroxyapatite nanoparticles exert a dual action, by promoting osteoblasts-driven matrix secretion and inhibiting osteoclasts-driven matrix resorption. Recombinant human bone morphogenetic protein 2 (rhBMP2) is a powerful osteoinductive biologic, used for the treatment of vertebral fractures and critically-sized bone defects. Although effective, the use of rhBMP2 has limitations due its recombinant morphogen nature. In this study, we examined the comparison between two osteoinductive agents: rhBMP2 and the innovative strontium-substituted hydroxyapatite nanoparticles. To test their effectiveness, we independently loaded Gelfoam sponges with the two osteoinductive agents and used the sponges as agent-carriers. Gelfoam are FDA-approved biodegradable medical devices used as delivery system for musculoskeletal defects. Their porous structure and spongy morphology make them attractive in orthopedic field. The abiotic characterization of the loaded sponges, involving ion release pattern and structure investigation, was followed by in vivo implantation onto the periosteum of healthy mice and comparison of the effects induced by each implant was performed. Abiotic analysis demonstrated that strontium was continuously released from the sponges over 28 days with a pattern similar to rhBMP2. Histological observations and gene expression analysis showed stronger endochondral ossification elicited by strontium compared to rhBMP2. Osteoclast activity was more inhibited by strontium than by rhBMP2. These results demonstrated the use of sponges loaded with strontium nanoparticles as potential bone grafts might provide better outcomes for complex fractures. Strontium nanoparticles are a novel and effective non-biologic treatment for bone injuries and can be used as novel powerful therapeutics for bone regeneration

    Розвиток духовності особистості в процесі фахової підготовки майбутніх учителів образотворчого мистецтва

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    (uk) У статті наголошується, що вчитель образотворчого мистецтва виступає носієм не лише спеціальних знань та умінь, але і носієм духовних цінностей. Духовне збагачення і вдосконалення кожної особистості відбувається протягом всього життя в тому числі і в процесі навчання. Гуманізація освіти та естетичне виховання спрямовано на формування гармонійної цілісної особистості, загальнокультурний її розвиток. Засобами естетичного виховання в мистецтві виступає художній образ. Художній образ є відображенням дійсності яке містить в собі не лише суб’єктивний досвід автора, його розуміння та відношення до об’єктів дійсності, але і відбитки культурно-історичного досвіду, естетичних цінностей, але і відбитки культурно-історичного досвіду, естетичних цінностей соціуму загалом. На їх базі і формується всебічно та гармонійно розвинута особистість із вищими моральними цінностями, естетичними канонами та ідеалами.(ru) В статье делается акцент на то, что учитель изобразительного искусства выступает носителем не только специальных знаний и умений, но и носителем духовных ценностей. Духовное обогащение и совершенствование каждой личности происходит на протяжении всей жизни в том числе и в процессе обучения. Гуманизация образования и эстетическое воспитание направлены на формирование гармоничной целостной личности и ее общекультурное развитие. Средством эстетического воспитания в искусстве выступает художественный образ. Художественный образ является отражением действительности, которое содержит в себе не только субъективный опыт автора, его понимание и отношение к объектам действительности, но и отпечатки культурно-исторического опыта, эстетических ценностей социума в целом. На их базе и формируется всесторонне и гармонично развитая личность с высокими моральными ценностями, эстетическими канонами и идеалами.(en) Importance of education in society is determined by the need to raise the national consciousness of the saved and nurturing genuine citizen. Spiritual enrichment and improvement of each individual occurs throughout life including during training. Spirituality determines the direction of all mental, emotional, sensual, strong-willed human qualities and its ability to self yourself as a person. Master of Fine Arts acting carrier not only specialized knowledge and skills, but also a bearer of spiritual values. Humanizing education and aesthetic education aims at forming a harmonious whole person, her general cultural development. Art is an integral part of spiritual culture, a reflection of the artistic representations of the human form of the world of reality. The means of aesthetic education in the art of acting artistic image. Artistic image is a reflection of reality, which contains not only the subjective experience of the author, and understanding related to the objects of reality, but the prints are of cultural and historical experience, the aesthetic values of society as a whole. At their base is formed fully and harmoniously developed personality with higher moral values, aesthetic canons and ideals
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