436 research outputs found

    Bellows design features low spring rate and long life

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    High pressure bellows has high strength rigid hoops for strength and stability and sheet stock for low spring rate effects. The simplicity of this bellows design facilitates mass production

    Concussion Knowledge Among Family Physicians in Croatia

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    Aim: The objective of this study was to administer and analyze results of a survey targeting knowledge about concussion symptoms, diagnosis, treatment and expected recovery among family medicine specialists in the Split-Dalmatia County of Croatia. Methods: An electronic survey questionnaire was developed utilizing concepts from previously published studies on concussion knowledge, attitudes and beliefs completed by physicians. The survey was intended to briefly and broadly assess concussion knowledge of Croatian healthcare providers. The first section of the survey included five questions clarifying professional practice, years of experience and experience with concussions; the second section included 15 questions about typical concussion symptoms; the third section included 12 questions focused upon three primary components of concussion knowledge: concussion diagnosis, treatment and recovery. Results: Out of 242 surveys mailed, 81 questionnaires (33%) were completed while 161 respondents (67%) did not answer. Out of the 81 completed surveys, 76 (94%) were returned by family physicians specialist and five (6%) by resident physicians in training. 39 (48%) had treated less than ten patients with concussion during last year: 40 (49%) treated 11-20 patients with concussion; and two (3%) treated greater than 20 patients with concussion during last year. While most responses did accurately reflect knowledge of common symptoms (90-100% correct), there was significant lack of knowledge in three areas: only 19% of participants stated that diagnosis of concussion does not require loss of consciousness; three quarters of respondents believed that a diagnosis of concussion requires direct contact to the head and 83% of the respondents believed that persistent subjective complaints are always the result of a more severe initial injury. Discussion: This is the first investigation conducted in Croatia to examine knowledge of concussion diagnosis, as well as the management practices held by medical professionals. Overall, the findings suggest that the knowledge and management practices among family doctors in the region are not consistent with current worldwide views and recommendations. There was not an accurate knowledge of concussion diagnosis, treatment, recovery and prognosis among family physicians. Continued education of medical staff to better identify concussion and increased reliance on objective methods for managing concussion will improve patient management and outcome

    Restriction enzyme-free mutagenesis via the light regulation of DNA polymerization

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    The effects of photocaged nucleosides on the DNA polymerization reaction was investigated, finding that most polymerases are unable to recognize and read through the presence of a single caging group on the DNA template. Based on this discovery, a new method of introducing mutations into plasmid DNA via a light-mediated mutagenesis protocol was developed. This methodology is advantageous over several common approaches in that it requires the use of only two polymerase chain reaction primers, and does not require any restriction sites or use of restriction enzymes. Additionally, this approach enables not only site-directed mutations, but also the insertion of DNA strands of any length into plasmids and the deletion of entire genes from plasmids

    Interacció llum-matèria i efecte hivernacle : seqüència didàctica per a l'estudi de l'espectroscòpia

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    Treball que correspon a les pràctiques que es fan als tallers REVIR organitzats pel CRECIM de la UAB. La seqüència pretén que l'alumnat de 1r i 2n de Batxillerat assoleixi una major comprensió de la interacció entre la radiació electromagnètica i la matèria. El punt de partida és un fenomen tan conegut com és l'efecte hivernacle, que porta a plantejar la pregunta: Com es pot explicar, des d'un punt de vista químic, la diferència entre els gasos que provoquen efecte hivernacle i els que no

    Optochemical control of RNA interference in mammalian cells

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    Short interfering RNAs (siRNAs) and microRNAs (nniRNAs) have been widely used in mammalian tissue culture and model organisms to selectively silence genes of interest. One limitation of this technology is the lack of precise external control over the gene-silencing event. The use of photocleavable protecting groups installed on nucleobases is a promising strategy to circumvent this limitation, providing high spatial and temporal control over siRNA or miRNA activation. Here, we have designed, synthesized and site-specifically incorporated new photocaged guanosine and uridine RNA phosphoramidites into short RNA duplexes. We demonstrated the applicability of these photocaged siRNAs in the light-regulation of the expression of an exogenous green fluorescent protein reporter gene and an endogenous target gene, the mitosis motor protein, Eg5. Two different approaches were investigated with the caged RNA molecules: the light-regulation of catalytic RNA cleavage by RISC and the light-regulation of seed region recognition. The ability to regulate both functions with light enables the application of this optochemical methodology to a wide range of small regulatory RNA molecules

    Pharmacologic topoisomerase-I inhibition causes DNA damage and mortality in activated CD4+ T cells

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    Topoisomerase-I is required for DNA replication. It acts by preventing torsional stress caused by DNA winding during replication fork progression.  Topoisomerase-I inhibitors are widely used in many cancer therapies, in light of their anti-proliferative activity. However, their use as chemotherapeutics is associated with significant toxicity due to the off-target effects on healthy cells. We analyzed the dose-time-toxicity profile of a clinically employed topoisomerase-I inhibitor, i.e. topotecan, on primary CD4+T cells. This cell type was chosen to model a typical in-vivo interaction, due to the wide use of topotecan in the treatment of T-cell lymphomas. Our results show that a clinically achievable concentration of topotecan can induce toxic effects in healthy CD4+ T cells as early as 7 hours of the in vitro treatment. Toxicity of the drug was markedly increased by prolonging the post-treatment follow-up, but not by increasing concentrations, suggesting that clinical doses of topotecan can induce cell death and DNA damage in non-cancerous activated CD4+ T lymphocytes
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