1,219 research outputs found

    Towards simultaneous electrical and optical investigation of BLMS using a novel microfluidic device

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    We firstly describe the influence of the phospholipid (PL) composition of bilayer lipid membrane on their electrical properties: (i) the more unsaturations in the tail, the earlier the BLM breakdown and (ii) the bulkier the head group, the less stable the membrane. Secondly, we design and fabricate novel devices that couple such electri-cal characterization to optical investigation and that enable the preparation of asym-metrical membranes: a “macro” device including a drilled PMMA plate as well as microfluidic device consisting of a glass-teflon foil-glass sandwich

    Bursts and Horizontal Evolution of DNA Transposons in the Speciation of Pseudotetraploid Salmonids

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    Background: Several genome duplications have occurred in the evolutionary history of teleostfish. In returning to a stable diploid state, the polyploid genome reorganized, and large portions arelost, while the fish lines evolved to numerous species. Large scale transposon movement has beenpostulated to play an important role in the genome reorganization process. We analyzed the DNAsequence of several large loci in Salmo salar and other species for the presence of DNA transposonfamilies.Results: We have identified bursts of activity of 14 families of DNA transposons (12 Tc1-like and2 piggyBac-like families, including 11 novel ones) in genome sequences of Salmo salar. Several ofthese families have similar sequences in a number of closely and distantly related fish, lamprey, andfrog species as well as in the parasite Schistosoma japonicum. Analysis of sequence similaritiesbetween copies within the families of these bursts demonstrates several waves of transpositionactivities coinciding with salmonid species divergence. Tc1-like families show a master gene-likecopying process, illustrated by extensive but short burst of copying activity, while the piggyBac-likefamilies show a more random copying pattern. Recent families may include copies with an openreading frame for an active transposase enzyme.Conclusion: We have identified defined bursts of transposon activity that make use of masterslaveand random mechanisms. The bursts occur well after hypothesized polyploidy events andcoincide with speciation events. Parasite-mediated lateral transfer of transposons are implicated

    Inter-physician agreement on the readiness of sick-listed employees to return to work

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    Purpose: To determine the agreement between occupational physician (OP) ratings of an employee's readiness to return to work (RRTW). Method: Anonymized written vignettes of 132 employees, sick-listed for at least 3 weeks, were reviewed by 5 OPs. The OPs intuitively rated RRTW as the ability (knowledge and skills) and willingness (motivation and confidence) of sick-listed employees to resume work. Inter-OP percentages of agreement were calculated and Cohen's kappas (kappa) were determined to correct for agreement by chance. Results: The percentage of agreement between OPs was 57% (range 39-89%) on the ability and 63% (range 48-87%) on the willingness of sick-listed employees to resume work. The mean. was 0.14 (range from -0.21 to 0.79) for ability and 0.25 (range from -0.11 to 0.74) for willingness. The OP-rating of RRTW of employees sick-listed with mental disorders did not differ from the OP-rating of RRTW of employees with musculoskeletal disorders. Conclusion: The inter-OP agreement on intuitively rated RRTW showed a wide variability, which accentuates the need for instruments to establish an employee's RRTW and for training in giving well founded return to work recommendations

    Mechanical tuning of optical race-track ring resonators

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    This paper presents the fabrication and mechanical characterization of electrostatically actuated micro bimorphs integrated with race-track ring resonators, for optical tuning applications. The bimorphs, having an upward deflection in the off-state, are integrated by surface micromachining techniques with race-track ring resonators fabricated on Silicon On Insulator (SOI) wafers. Using electrostatic actuation, these bimorphs are pulled into the evanescent field of the ring resonator thereby modulating the propagation properties. Pull-in voltages of the bimorphs have been measured statically and the effect of electrostatic spring softening (ESS) on the resonance frequency has been measured dynamically. The resonance wavelength of the optical ring resonator could be tuned by 50 pm by applying an 8.5 V DC voltage to a 40 ÎĽm long bimorph, bringing it into close proximity of the ring resonator waveguide. To the best of our knowledge, this is the first experimental demonstration of tuning of race track ring resonators by integrated, electrostatically actuated bimorphs.\ud \u

    Design, fabrication and characterization of a suspended plate mechano-optical modulator

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    A mechano-optical modulator is presented based on the Integrated Optical Nano-Mechanical (IONM) effect. It consists of a light-weight, rigid silicon-nitride suspended plate structure with strengthening ridges and bi-directional electrostatic actuation to maximize switching speed. The mechanical structure and optical waveguide are realized on separate chips and then assembled together resulting in hybrid integration. The latter is made possible by using a self-alignment technique which results in a misalignment error of at most 2 ÎĽm

    Influence of timing of maternal antibiotic administration during caesarean section on infant microbial colonisation:a randomised controlled trial

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    OBJECTIVE: Revised guidelines for caesarean section (CS) advise maternal antibiotic administration prior to skin incision instead of after umbilical cord clamping, unintentionally exposing the infant to antibiotics antenatally. We aimed to investigate if timing of intrapartum antibiotics contributes to the impairment of microbiota colonisation in CS born infants. DESIGN: In this randomised controlled trial, women delivering via CS received antibiotics prior to skin incision (n=20) or after umbilical cord clamping (n=20). A third control group of vaginally delivering women (n=23) was included. Faecal microbiota was determined from all infants at 1, 7 and 28 days after birth and at 3 years by 16S rRNA gene sequencing and whole-metagenome shotgun sequencing. RESULTS: Compared with vaginally born infants, profound differences were found in microbial diversity and composition in both CS groups in the first month of life. A decreased abundance in species belonging to the genera Bacteroides and Bifidobacterium was found with a concurrent increase in members belonging to the phylum Proteobacteria. These differences could not be observed at 3 years of age. No statistically significant differences were observed in taxonomic and functional composition of the microbiome between both CS groups at any of the time points. CONCLUSION: We confirmed that microbiome colonisation is strongly affected by CS delivery. Our findings suggest that maternal antibiotic administration prior to CS does not result in a second hit on the compromised microbiome. Future, larger studies should confirm that antenatal antibiotic exposure in CS born infants does not aggravate colonisation impairment and impact long-term health

    A Pharmaceutical Care Program to Improve Adherence to Statin Therapy:A Randomized Controlled Trial

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    BACKGROUND: Despite the well-known beneficial effects of statins, many patients do not adhere to chronic medication regimens. OBJECTIVE: To implement and assess the effectiveness of a community pharmacy based pharmaceutical care program developed to improve patients' adherence to statin therapy. METHODS: An open-label, prospective, randomized controlled trial was conducted at 26 community pharmacies in the Netherlands. New users of statins who were aged 18 years or older were randomly assigned to receive either usual care or a pharmacist intervention. The intervention consisted of 5 individual counseling sessions by a pharmacist during a 1-year period. During these sessions, patients received structured education about the importance of medication adherence, lipid levels were measured, and the association between adherence and lipid levels was discussed. Adherence to statin therapy was assessed as discontinuation rates 6 and 12 months after statin initiation, and as the medication possession ratio (MPR), and compared between the pharmaceutical care and usual care groups. RESULTS: A total of 899 subjects (439 in the pharmaceutical care group and 460 in the usual care group) were evaluable for effectiveness analysis. The pharmaceutical care program resulted in a significantly lower rate of discontinuation within 6 months after initiating therapy versus usual care (HR 0.66, 95% Cl 0.46 to 0.96). No significant difference between groups was found in discontinuation at 12 months (HR 0.84, 95% Cl 0.65 to 1.10). Median MPR was very high (>99%) in both groups and did not differ between groups. CONCLUSIONS: These results demonstrate the feasibility and effectiveness of a community pharmacy based pharmaceutical care program to improve medication adherence in new users of statins. Frequent counseling sessions (every 3 months) are necessary to maintain the positive effects on discontinuation. Although improvements are modest, the program can be applied easily to a larger population and have a large impact, as the interventions are relatively inexpensive and easy to, implement in clinical practice
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