605 research outputs found

    Postpartum Safety and Satisfaction Following Early Discharge

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    Two Ontario sites were involved in the evaluation of an obstetrical discharge program. Before program implementation a group of eligible women were enrolled as the preprogram control group (n = 542). During the program, eligible women who agreed to early discharge (ED) became the ED group (n = 319), and those opting not to go home early but consenting to participate in the evaluation became the concurrent group (n = 456). All groups were mailed a self-administered postpartum questionnaire. On demographic characteristics, safety and satisfaction, the ED group was comparable to the concurrent group. Hospital readmission rates did not differ across groups after stratification by site or hospital. Multiple classification analyses revealed a similar pattern for overall satisfaction levels. This unique ED program, which allowed pre- or postnatal enrollment and did not require an initial home assessment, appears to be a safe, effective and flexible approach to obstetrical care

    Examining solution and solid state composition for the solution mediated polymorphic transformation of carbamazepine and piracetam

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    peer-reviewedSolution mediated polymorphic transformations (SMPT) of the pharmaceutical compounds carbamazepine and piracetam have been investigated. Seeded transformation experiments were performed, and the solution concentration was monitored by in situ infra-red spectroscopy using a calibration free method. Solid samples were also taken over time, and the percentage of metastable and stable polymorphic phases were determined using off line quantitative powder X-ray diffraction analysis. Solution and solid state data were compared for each compound. In the case of carbamazepine, the SMPT from FI to FIII was identified as being controlled by the growth of the stable FIII polymorph. For piracetam, the SMPT was also identified as being controlled by growth of the stable polymorph, but with a more considerable induction time for nucleation of the stable phase. This paper demonstrates how the rate determining steps of the SMPT can be identified if both solution and solid phase data are recorded. The results are compared with other studies reported in the literature and rationalized into four principal scenarios

    Influence of acoustic cavitation on the controlled ultrasonic dispersion of carbon nanotubes.

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    Ultrasonication is the most widely used technique for the dispersion of a range of nanomaterials, but the intrinsic mechanism which leads to stable solutions is poorly understood with procedures quoted in the literature typically specifying only extrinsic parameters such as nominal electrical input power and exposure time. Here we present new insights into the dispersion mechanism of a representative nanomaterial, single-walled carbon nanotubes (SW-CNTs), using a novel up-scalable sonoreactor and an in situ technique for the measurement of acoustic cavitation activity during ultrasonication. We distinguish between stable cavitation, which leads to chemical modification of the surface of the CNTs, and inertial cavitation, which favors CNT exfoliation and length reduction. Efficient dispersion of CNTs in aqueous solution is found to be dominated by mechanical forces generated via inertial cavitation, which in turn depends critically on surfactant concentration. This study highlights that careful measurement and control of cavitation rather than blind application of input power is essential in the large volume production of nanomaterial dispersions with tailored properties

    Support to woman by a companion of her choice during childbirth: a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>To evaluate the effectiveness and safety of the support given to women by a companion of their choice during labor and delivery.</p> <p>Methods</p> <p>A total of 212 primiparous women were enrolled in a randomized controlled clinical trial carried out between February 2004 and March 2005. One hundred and five women were allocated to the group in which support was permitted and 107 to the group in which there was no support. Variables regarding patient satisfaction and events related to obstetrical care, neonatal results and breastfeeding were evaluated. Student's t-test or Wilcoxon's test, chi-square or Fisher's exact test, risk ratios, and their respective 95% confidence intervals were used in the statistical analysis.</p> <p>Results</p> <p>Overall, the women in the support group were more satisfied with labor (median 88.0 versus 76.0, p < 0.0001) and delivery (median 91.4 versus 77.1, p < 0.0001). During labor, patient satisfaction was associated with the presence of a companion (RR 8.06; 95%CI: 4.84 – 13.43), with care received (RR 1.11; 95%CI: 1.01 – 1.22) and with medical guidance (RR 1.14 95%CI: 1.01 – 1.28). During delivery, satisfaction was associated with having a companion (RR 5.57, 95%CI: 3.70 – 8.38), with care received (RR 1.11 95%CI: 1.01 – 1.22) and with vaginal delivery (RR 1.33 95%CI:1.02 – 1.74). The only factor that was significantly lower in the support group was the occurrence of meconium-stained amniotic fluid (RR 0.51; 95%CI: 0.28 – 0.94). There was no statistically significant difference between the two groups with respect to any of the other variables.</p> <p>Conclusion</p> <p>The presence of a companion of the woman's choice had a positive influence on her satisfaction with the birth process and did not interfere with other events and interventions, with neonatal outcome or breastfeeding.</p

    High-resolution hydraulic parameter maps for surface soils in tropical South America

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    Modern land surface model simulations capture soil profile water movement through the use of soil hydraulics sub-models, but good hydraulic parameterisations are often lacking, especially in the tropics. We present much-improved gridded data sets of hydraulic parameters for surface soil for the critical area of tropical South America, describing soil profile water movement across the region to 30 cm depth. Optimal hydraulic parameter values are given for the Brooks and Corey, Campbell, van Genuchten–Mualem and van Genuchten–Burdine soil hydraulic models, which are widely used hydraulic sub-models in land surface models. This has been possible through interpolating soil measurements from several sources through the <i>SOTERLAC</i> soil and terrain data base and using the most recent pedotransfer functions (PTFs) derived for South American soils. All soil parameter data layers are provided at 15 arcsec resolution and available for download, this being 20x higher resolution than the best comparable parameter maps available to date. Specific examples are given of the use of PTFs and the importance highlighted of using PTFs that have been locally parameterised and that are not just based on soil texture. We discuss current developments in soil hydraulic modelling and how high-resolution parameter maps such as these can improve the simulation of vegetation development and productivity in land surface models

    Sonocrystallisation of ZIF-8 in water with high excess of ligand: Effects of frequency, power and sonication time

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    A systematic study on the sonocrystallisation of ZIF-8 (zeolitic imidazolate framework-8) in a water-based system was investigated under different mixing speeds, ultrasound frequencies, calorimetric powers and sonication time. Regardless of the synthesis technique, pure crystals of ZIF-8 with high BET (Brunauer, Emmett and Teller) specific surface area (SSA) can be obtained in water after only 5 s. Furthermore, 5 s sonication produced even smaller crystals (~0.08 µm). The type of technique applied for producing the ZIF-8 crystals did not have any significant impact on crystallinity, purity and yield. Crystal morphology and size were affected by the use of ultrasound and mixing, obtaining nanoparticles with a more spherical shape than in silent condition (no ultrasound and mixing). However, no specific trends were observed with varying frequency, calorimetric power and mixing speed. Ultrasound and mixing may have an effect on the nucleation step, causing the fast production of nucleation centres. Furthermore, the BET SSA increased with increasing mixing speed. With ultrasound, the BET SSA is between the values obtained under silent condition and with mixing. A competition between micromixing and shockwaves has been proposed when sonication is used for ZIF-8 production. The former increases the BET SSA, while the latter could be responsible for porosity damage, causing a decrease of the surface area. © 2021 The Author(s

    Studying the impact of the pre-exponential factor on templated nucleation

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    Traditionally, the enhancement of nucleation rates in the presence of heterogeneous surfaces in crystallisation processes has been attributed to the modification of the interfacial energy of the system according to the classical nucleation theory. However, recent developments have shown that heterogeneous surfaces instead alter the pre-exponential factor of nucleation. In this work, the nucleation kinetics of glycine and diglycine in aqueous solutions have been explored in the presence and absence of a heterogeneous surface. Results from induction time experiments show that the presence of a heterogeneous surface increases the pre-exponential factor by 2-fold or more for both glycine and diglycine, while the interfacial energy remains unchanged for both species. This study suggests that the heterogeneous surface enhances the nucleation rate via hydrogen bond formation with both glycine and diglycine. This is verified by hydrogen bond propensity calculations, molecular functionality analysis, and calculation of the time taken for a solute molecule to attach to the growing nucleus, which is an order of magnitude shorter than the estimated lifetime of the hydrogen bond. The effect of the heterosurface is of greater magnitude for diglycine than for glycine, which may be due to the heightened molecular complementarity between the hydrogen bond donor and acceptor sites on diglycine and the heterosurface

    N-(3-Nitro­benzyl­idene)aniline

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    In the title compound, C13H10N2O2, a Schiff base derivative, the dihedral angle between the two aromatic rings is 31.58 (3)°. The C=N double bond is essentially coplanar with the nitro­phenyl ring. The torsion angle of the imine double bond is 175.97 (13)°, indicating that the C=N double bond is in a trans configuration. The crystal structure is stabilized by C—H⋯O contacts and π–π inter­actions (centroid–centroid distances of 3.807 and 3.808Å)
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