1,840 research outputs found

    The treatment of soft-tissue defects of the lower leg after a traumatic open tibial fracture

    Get PDF
    The treatment of large soft-tissue defects of the lower leg remains a challenge. The timing of the operation, the most suitable type of tissue, and the decision between local or free flap coverage still remains under discussion. Fifty-two patients were treated with local or free flap coverage after a traumatic soft-tissue defect of the lower leg. We compared the results after treatment with local versus free flaps and fasciocutaneous flaps versus musculocutaneous flaps. In the case of primary reconstruction, we also compared the results regarding the timing of the operation: patients treated within 72 h after the trauma versus patients treated after 72 h. Thirty-five patients (67%) have been treated because of posttraumatic soft-tissue defects and, therefore, insufficient fracture coverage. Seventeen patients (33%) were treated because of a chronic osteomyelitis that arose after the trauma. In our study, we did not find a statistically significant difference between the postoperative complications of local and free flaps. A significant increase could be demonstrated in the number of revisions after treatment with a free flap. Treatment with a fasciocutaneous flap in the entire study group was associated with significantly more postoperative complications than treatment with a musculocutaneous flap. There was no significant difference in results after early or late flap coverage. Patients treated with local or free flaps achieved equal outcomes, except for the number of postoperative revisions in which local flaps required lesser revisions. Treatment with a musculocutaneous flap is preferable to treatment with a fasciocutaneous flap regarding postoperative complications. The timing of operation proved not to be a discriminating factor

    Twist1 Is a TNF-Inducible Inhibitor of Clock Mediated Activation of Period Genes.

    Get PDF
    BACKGROUND: Activation of the immune system affects the circadian clock. Tumor necrosis factor (TNF) and Interleukin (IL)-1β inhibit the expression of clock genes including Period (Per) genes and the PAR-bZip clock-controlled gene D-site albumin promoter-binding protein (Dbp). These effects are due to cytokine-induced interference of E-box mediated transcription of clock genes. In the present study we have assessed the two E-box binding transcriptional regulators Twist1 and Twist2 for their role in cytokine induced inhibition of clock genes. METHODS: The expression of the clock genes Per1, Per2, Per3 and of Dbp was assessed in NIH-3T3 mouse fibroblasts and the mouse hippocampal neuronal cell line HT22. Cells were treated for 4h with TNF and IL-1β. The functional role of Twist1 and Twist2 was assessed by siRNAs against the Twist genes and by overexpression of TWIST proteins. In luciferase (luc) assays NIH-3T3 cells were transfected with reporter gene constructs, which contain a 3xPer1 E-box or a Dbp E-box. Quantitative chromatin immunoprecipitation (ChIP) was performed using antibodies to TWIST1 and CLOCK, and the E-box consensus sequences of Dbp (CATGTG) and Per1 E-box (CACGTG). RESULTS: We report here that siRNA against Twist1 protects NIH-3T3 cells and HT22 cells from down-regulation of Period and Dbp by TNF and IL-1β. Overexpression of Twist1, but not of Twist2, mimics the effect of the cytokines. TNF down-regulates the activation of Per1-3xE-box-luc, the effect being prevented by siRNA against Twist1. Overexpression of Twist1, but not of Twist2, inhibits Per1-3xE-box-luc or Dbp-E-Box-luc activity. ChIP experiments show TWIST1 induction by TNF to compete with CLOCK binding to the E-box of Period genes and Dbp. CONCLUSION: Twist1 plays a pivotal role in the TNF mediated suppression of E-box dependent transactivation of Period genes and Dbp. Thereby Twist1 may provide a link between the immune system and the circadian timing system

    Competitive interactions are mediated in a sex-specific manner by arbuscular mycorrhiza in Antennaria dioica

    Get PDF
    Plants usually interact with other plants, and the outcome of such interaction ranges from facilitation to competition depending on the identity of the plants, including their sexual expression. Arbuscular mycorrhizal (AM) fungi have been shown to modify competitive interactions in plants. However, few studies have evaluated how AM fungi influence plant intraspecific and interspecific interactions in dioecious species. The competitive abilities of female and male plants of Antennaria dioica were examined in a greenhouse experiment. Females and males were grown in the following competitive settings: (i) without competition, (ii) with intrasexual competition, (iii) with intersexual competition, and (iv) with interspecific competition by Hieracium pilosella – a plant with similar characteristics to A. dioica. Half of the pots were grown with Claroideoglomus claroideum, an AM fungus isolated from the same habitat as the plant material. We evaluated plant survival, growth, flowering phenology, and production of AM fungal structures. Plant survival was unaffected by competition or AM fungi. Competition and the presence of AM fungi reduced plant biomass. However, the sexes responded differently to the interaction between fungal and competition treatments. Both intra- and interspecific competition results were sex-specific, and in general, female performance was reduced by AM colonization. Plant competition or sex did not affect the intraradical structures, extraradical hyphae, or spore production of the AM fungus. These findings suggest that plant sexual differences affect fundamental processes such as competitive ability and symbiotic relationships with AM fungi

    Study of led lamp power supply

    Get PDF
    В данной статье исследуется источник питания светодиодного светильника с высокимкоэффициентом мощности. Использована микросхема корректора коэффициента мощности компании STMicroelectronics L6561 в обратноходовой топологии. С помощью этой микросхемы упрощается построение источника питания, учитывая стандарты энергосбережения и требования к уровню вносимых в питающую сеть искажений.In this article, we investigate the LED lamp power supply with a high power factor. To implement this, the power factor corrector of STMicroelectronics L6561 is used in the fly-back topology. With the help of this IC simplifies the construction of the power supply, considering energy-efficiency standards and requirements for the level introduced into the mains distortion.Fir filter design using frequency sampling method

    Effects of auditory feedback consistency on vowel production

    Get PDF
    In investigations of feedback control during speech production, researchers have focused on two different kinds of responses to erroneous or unexpected auditory feedback. Compensation refers to online, feedback-based corrections of articulations. In contrast, adaptation refers to long-term changes in the speech production system after exposure to erroneous/unexpected feedback, which may last even after feedback is normal again. In the current study, we aimed to compare both types of feedback responses by investigating the conditions under which the system starts adapting in addition to merely compensating. Participants vocalized long vowels while they were exposed to either consistently altered auditory feedback, or to feedback that was unpredictably either altered or normal. Participants were not aware of the manipulation of auditory feedback. We predicted that both conditions would elicit compensation, whereas adaptation would be stronger when the altered feedback was consistent across trials. The results show that although there seems to be somewhat more adaptation for the consistently altered feedback condition, a substantial amount of individual variability led to statistically unreliable effects at the group level. The results stress the importance of taking into account individual differences and show that people vary widely in how they respond to altered auditory feedback

    Spike-phase coupling patterns reveal laminar identity in primate cortex

    Get PDF
    The cortical column is one of the fundamental computational circuits in the brain. In order to understand the role neurons in different layers of this circuit play in cortical function it is necessary to identify the boundaries that separate the laminar compartments. While histological approaches can reveal ground truth they are not a practical means of identifying cortical layers in vivo. The gold standard for identifying laminar compartments in electrophysiological recordings is current-source density (CSD) analysis. However, laminar CSD analysis requires averaging across reliably evoked responses that target the input layer in cortex, which may be difficult to generate in less well-studied cortical regions. Further, the analysis can be susceptible to noise on individual channels resulting in errors in assigning laminar boundaries. Here, we have analyzed linear array recordings in multiple cortical areas in both the common marmoset and the rhesus macaque. We describe a pattern of laminar spike-field phase relationships that reliably identifies the transition between input and deep layers in cortical recordings from multiple cortical areas in two different non-human primate species. This measure corresponds well to estimates of the location of the input layer using CSDs, but does not require averaging or specific evoked activity. Laminar identity can be estimated rapidly with as little as a minute of ongoing data and is invariant to many experimental parameters. This method may serve to validate CSD measurements that might otherwise be unreliable or to estimate laminar boundaries when other methods are not practical

    Function of the fully conserved residues Asp99, Tyr52 and Tyr73 in phospholipase A2

    Get PDF
    In the active centre of pancreatic phospholipase A2 His48 is at hydrogen-bonding distance to Asp99. This Asp-His couple is assumed to act together with a water molecule as a catalytic triad. Asp99 is also linked via an extended hydrogen bonding system to the side chains of Tyr52 and Tyr73. To probe the function of the fully conserved Asp99, Tyr52 and Tyr73 residues in phospholipase A2, the Asp99 residue was replaced by Asn, and each of the two tyrosines was separately replaced by either a Phe or a Gln. The catalytic and binding properties of the Phe52 and Phe73 mutants did not change significantly relative to the wild-type enzyme. This rules out the possibility that either one of the two Tyr residues in the wild-type enzyme can function as an acyl acceptor or proton donor in catalysis. The Gln73 mutant could not be obtained in any significant amounts probably due to incorrect folding. The Gln52 mutant was isolated in low yield. This mutant showed a large decrease in catalytic activity while its substrate binding was nearly unchanged. The results suggest a structural role rather than a catalytic function of Tyr52 and Tyr73. Substitution of asparagine for aspartate hardly affects the binding constants for both monomeric and micellar substrate analogues. Kinetic characterization revealed that the Asn99 mutant has retained no less than 65% of its enzymatic activity on the monomeric substrate rac 1,2-dihexanoyldithio-propyl-3-phosphocholine, probably due to the fact that during hydrolysis of monomeric substrate by phospholipase A2 proton transfer is not the rate-limiting step. The Asp to Asn substitution decreases the catalytic rate on micellar 1,2-dioctanoyl-sn-glycero-3-phosphocholine 25-fold. To explain this remaining activity we suggest that in the mutant the Asn99 orients His48 in the same way as Asp99 orients His48 in native phospholipase A2 and that the lowered activity is caused by a reduced stabilization of the transition state

    How should a virtual agent present psychoeducation?

    Get PDF
    BACKGROUND AND OBJECTIVE: With the rise of autonomous e-mental health applications, virtual agents can play a major role in improving trustworthiness, therapy outcome and adherence. In these applications, it is important that patients adhere in the sense that they perform the tasks, but also that they adhere to the specific recommendations on how to do them well. One important construct in improving adherence is psychoeducation, information on the why and how of therapeutic interventions. In an e-mental health context, this can be delivered in two different ways: verbally by a (virtual) embodied conversational agent or just via text on the scree
    corecore