Tunable Phase Gratings by Wrinkling of Plasma-Oxidized PDMS: Gradient Skins and Multiaxial Patterns

Wrinkling instabilities in polymeric bilayers have been exploited as optical phase gratings with tunable performance. Here, we report strain modulated 1D and 2D phase gratings fabricated by the ubiquitous process of plasma-oxidation of polydimethylsiloxane (PDMS). While surface oxidation provides a remarkably facile glassy skin formation approach, minimizing delamination and debonding, it inherently results in a gradient conversion profile emanating from the top film interface. We examine and quantitatively model the consequences of this gradient layer on the optical properties of the resulting strain-tunable phase gratings. Diffraction efficiencies up to 48% are demonstrated. We then develop and validate a surface reconstruction methodology based on the diffraction pattern of our sinusoidal gratings and our model, which we extend to the high deformation regimes and to 2D gratings, obtained by superposition of two wrinkling generations, where both amplitudes and wavelengths can be independently tuned. Overall, this approach provides a rapid, robust and predictive framework for the design and fabrication of tunable, single, and multiaxial surface gratings

Mechanically Induced Phase Change in Barbituric Acid

By grinding a commercial sample of barbituric acid in its trioxo form (polymorph II, 99%) for 24 h, a new compound has been isolated. The new phase has been identified as the trihydroxyl isomer. The characterization of the new isomer has been carried out by means of X-ray powder diffraction, solid-state NMR (1H MAS, 13C and 15N CPMAS, 2D PASS, and FSLG-HETCOR), IR and Raman spectroscopies. The conversion results from the complete tautomeric shift of a methylene and of two N−H hydrogen atoms. 1H MAS spectra allow the characterization of the hydrogen bond interactions on the basis of their strength in the starting compound and in the new isomer. In solution, the trihydroxyl isomer immediately converts to the trioxo form as demonstrated by 1H NMR experiments in protic, aprotic, and amphiprotic solvents (D2O, MeOH-d4, DMSO-d6, acetone-d6)

Microbial Response to Micrometer-Scale Multiaxial Wrinkled Surfaces

We investigate the effect of micrometer-scale surface wrinkling on the attachment and proliferation of model bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli K12) and fungi (Candida albicans). Specifically, sinusoidal (1D), checkerboard (C), and herringbone (H) patterns were fabricated by mechanical wrinkling of plasma-oxidized polydimethylsiloxane (PDMS) bilayers and contrasted with flat (F) surfaces. Microbial deformation and orientation were found to correlate with the aspect ratio and commensurably with surface pattern dimensions and local pattern order. Significantly, the proliferation of P. aeruginosa could be described by a linear scaling between bacterial area coverage and available surface area, defined as a fraction of the line integral along each profile with negative curvature. However, in the early stages of proliferation (up to 6 h examined), that C and H patterns disrupt the spatial arrangement of bacteria, impeding proliferation for several hours and reducing it (by ∼50%) thereafter. Our findings suggest a simple framework to rationalize the impact of micrometer-scale topography on microbial action and demonstrate that multiaxial patterning order provides an effective strategy to delay and frustrate the early stages of bacterial proliferation

Effect of Different Evaporation Rates on Gypsum Habit: Mineralogical Implications for Natural Gypsum Deposits

When a solution saturated in CaSO4·2H2O evaporates at room temperature, gypsum crystals precipitate with both single and twinning habits. However, the twinning laws of gypsum involved in this process have long been debated. Recently, easy steps have been described to univocally recognize the twinning laws of gypsum. Therefore, in this study, we have replicated evaporation experiments and focused on identifying these twinning laws. Different precipitation frequencies of gypsum crystals with (i) curved habits and (ii) twins, according to the 100 and 101 penetration twinning laws, have been observed as the evaporation rate increased. The crystal aspect ratio (length/width crystal ratio) might serve as a quick measure for distinguishing between 100 and 101 penetration twinning laws, and the occurrence of these twinning laws in sedimentary environments is suggested. Moreover, high evaporation rates promote curved crystals with both symmetric and asymmetric habits. Based on crystallographic considerations, the asymmetric habit might be explained by a homoepitaxial mechanism, where systematic rotations of the common 2D coincidence cells occur. These results describe which of the twinning laws of gypsum are possible in a pure solution and, for the first time, establish a correlation between different gypsum habits and different evaporation rates, contributing to a better understanding of gypsum habit in evaporitic environments

Data_Sheet_2_Factor structure of post-operative quality of recovery questionnaire (QoR-15): An Italian adaptation and validation.docx

BackgroundThe Quality of Recovery questionnaire (QoR-15) is an English instrument for measuring quality of recovery in surgical patients, not yet translated and validated in Italian when the Enhanced Recovery After Surgery (ERAS) Piemonte studies were planned.ObjectiveTo produce the Italian version of the QoR-15 questionnaire, to evaluate its factorial structure and to assess the invariance between two types of surgery.MethodsThe Italian version (QoR-15I) was obtained translating and adapting the original version to the Italian context. The validation was performed suppling the QoR-15I to 3,784 patients enrolled in two parallel stepped wedge cluster randomised trials (ERAS Colon-rectum Piemonte; ERAS Gyneco Piemonte). The factor structure and its invariance between types of surgery was tested using confirmatory bifactor model and multi-group analysis. Comparative fit index (CFI), root mean square error of approximation (RMSEA), and standardized root mean square residual (SRMR) fit indices and their changes between nested models were used to assess the factor structure and the invariance.ResultsThe bifactor model showed good fit (RMSEA = 0.049, CFI =0.957, SRMR = 0.036) and provided a general recovery factor and two specific factors for physical and mental recovery. Eighty-four percent of the common variance is attributable to the general factor, and thus the QoR-15I is sufficiently ‘one-dimensional’ with an adequate reliability (ωh = 0.70). The ωs values for the physical and mental recovery factors were 0.01 and 0.13, respectively. Multigroup analysis supported configural (RMSEA = 0.053, CFI = 0.950, SRMR = 0.035) and metric invariance (ΔRMSEA = -0.004; ΔCFI = -0.002; ΔSRMR = 0.014), whereas the intercept constraint was removed from item 15 to obtain partial scalar invariance (ΔRMSEA = 0.002; ΔCFI = 0.007; ΔSRMR = 0.004). Construct validity was supported by a negative association of QoR-15I scores with all variables related to worse patient condition and more complex surgery.ConclusionOur results support the use of the QoR-15I as a valid, reliable, and clinically feasible tool for measuring the quality of recovery after surgery. The results of the confirmatory factor analyses suggest that a unique recovery score can be calculated and support measurement invariance of the QOR-15I across the two type of surgery, suggesting that the questionnaire has the same meaning and the same measurement parameters in colorectal and gynaecologic patients.</p

Data_Sheet_1_Factor structure of post-operative quality of recovery questionnaire (QoR-15): An Italian adaptation and validation.docx

BackgroundThe Quality of Recovery questionnaire (QoR-15) is an English instrument for measuring quality of recovery in surgical patients, not yet translated and validated in Italian when the Enhanced Recovery After Surgery (ERAS) Piemonte studies were planned.ObjectiveTo produce the Italian version of the QoR-15 questionnaire, to evaluate its factorial structure and to assess the invariance between two types of surgery.MethodsThe Italian version (QoR-15I) was obtained translating and adapting the original version to the Italian context. The validation was performed suppling the QoR-15I to 3,784 patients enrolled in two parallel stepped wedge cluster randomised trials (ERAS Colon-rectum Piemonte; ERAS Gyneco Piemonte). The factor structure and its invariance between types of surgery was tested using confirmatory bifactor model and multi-group analysis. Comparative fit index (CFI), root mean square error of approximation (RMSEA), and standardized root mean square residual (SRMR) fit indices and their changes between nested models were used to assess the factor structure and the invariance.ResultsThe bifactor model showed good fit (RMSEA = 0.049, CFI =0.957, SRMR = 0.036) and provided a general recovery factor and two specific factors for physical and mental recovery. Eighty-four percent of the common variance is attributable to the general factor, and thus the QoR-15I is sufficiently ‘one-dimensional’ with an adequate reliability (ωh = 0.70). The ωs values for the physical and mental recovery factors were 0.01 and 0.13, respectively. Multigroup analysis supported configural (RMSEA = 0.053, CFI = 0.950, SRMR = 0.035) and metric invariance (ΔRMSEA = -0.004; ΔCFI = -0.002; ΔSRMR = 0.014), whereas the intercept constraint was removed from item 15 to obtain partial scalar invariance (ΔRMSEA = 0.002; ΔCFI = 0.007; ΔSRMR = 0.004). Construct validity was supported by a negative association of QoR-15I scores with all variables related to worse patient condition and more complex surgery.ConclusionOur results support the use of the QoR-15I as a valid, reliable, and clinically feasible tool for measuring the quality of recovery after surgery. The results of the confirmatory factor analyses suggest that a unique recovery score can be calculated and support measurement invariance of the QOR-15I across the two type of surgery, suggesting that the questionnaire has the same meaning and the same measurement parameters in colorectal and gynaecologic patients.</p