Force-Based Wetting Characterization of Stochastic Superhydrophobic Coatings at Nanonewton Sensitivity.

Superhydrophobic coatings have extraordinary properties like self-cleaning and staying dry, and have recently appeared on industrial and consumer markets. The stochastic nature of the coating components and coating processes (e.g., spraying, painting) affects the uniformity of the water repellency across the coated substrate. The wetting properties of those coatings are typically quantified on macroscale using contact angle goniometry (CAG). Here, highly sensitive force-based methods, scanning droplet adhesion microscopy (SDAM), and micropipette force sensor (MFS), are used, to quantify the microscale heterogeneity in the wetting properties of stochastic superhydrophobic coatings with irregular surface topography that cannot be investigated by CAG. By mapping the wetting adhesion forces with SDAM and friction forces with MFS, it is demonstrated that even the best coatings on the market are prone to heterogeneities that induce stick-slip motion of droplets. Thus, owing to their high spatial and force resolution, the advantages of these techniques over CAG are demonstrated.

The effect of postoperative complications on health-related quality of life and survival 12 years after coronary artery bypass grafting - a prospective cohort study.

BACKGROUND: Despite the steady improvements in survival and operative safety, postoperative complications still remain a significant cause of morbidity and mortality after coronary artery bypass grafting (CABG). However, less is known on the impact of postoperative complications on health-related quality of life (QoL). The main objective of our study was to investigate the impact of postoperative complications on long-term QoL and survival after CABG surgery. METHODS: Data of 508 patients, who underwent isolated CABG was prospectively collected. The RAND-36 Health Survey (RAND-36) was used to evaluate patients' QoL status preoperatively, 1 year and 12 years after the surgery. Predefined postoperative complications were reported during primary and secondary hospital stay. QoL and survival analysis were performed primarily on three patient groups: patients with and without complications and patients with major adverse cardiac and cerebrovascular events (MACCE). RESULTS: In total 205(40%) of 508 patients had at least one postoperative complication and 73 (14%) experienced MACCE. Patients' thirty-day, 1-year and 10-year survival rates were, 99, 98, 84% without complications, 97, 95, 72% with complications, and 90, 89, 64% with MACCE, respectively (log-rank p < 0.001). Patients without complications showed significant(p < 0.05) improvements in seven and patients with complications in five out of eight RAND-36 QoL dimensions. All patient groups showed significant improvements in RAND-36 summary scores compared with preoperative values. Patients with complications and especially with MACCE had more profound decline in their RAND-36 summary scores while patients without complications maintained their health status best. CONCLUSIONS: Despite the constant deterioration, both patients with and without complications showed improvements even 12 years after CABG compared with preoperative state. Postoperative complications and especially MACCE were associated with impaired long-term QoL.

Design of robust superhydrophobic surfaces.

The ability of superhydrophobic surfaces to stay dry, self-clean and avoid biofouling is attractive for applications in biotechnology, medicine and heat transfer1-10. Water droplets that contact these surfaces must have large apparent contact angles (greater than 150 degrees) and small roll-off angles (less than 10 degrees). This can be realized for surfaces that have low-surface-energy chemistry and micro- or nanoscale surface roughness, minimizing contact between the liquid and the solid surface11-17. However, rough surfaces-for which only a small fraction of the overall area is in contact with the liquid-experience high local pressures under mechanical load, making them fragile and highly susceptible to abrasion18. Additionally, abrasion exposes underlying materials and may change the local nature of the surface from hydrophobic to hydrophilic19, resulting in the pinning of water droplets to the surface. It has therefore been assumed that mechanical robustness and water repellency are mutually exclusive surface properties. Here we show that robust superhydrophobicity can be realized by structuring surfaces at two different length scales, with a nanostructure design to provide water repellency and a microstructure design to provide durability. The microstructure is an interconnected surface frame containing 'pockets' that house highly water-repellent and mechanically fragile nanostructures. This surface frame acts as 'armour', preventing the removal of the nanostructures by abradants that are larger than the frame size. We apply this strategy to various substrates-including silicon, ceramic, metal and transparent glass-and show that the water repellency of the resulting superhydrophobic surfaces is preserved even after abrasion by sandpaper and by a sharp steel blade. We suggest that this transparent, mechanically robust, self-cleaning glass could help to negate the dust-contamination issue that leads to a loss of efficiency in solar cells. Our design strategy could also guide the development of other materials that need to retain effective self-cleaning, anti-fouling or heat-transfer abilities in harsh operating environments.

Diabetics have Inferior Long-Term Survival and Quality of Life after CABG.

A prevalence of diabetes is increasing among the patients undergoing coronary artery bypass grafting (CABG). Data on whether health-related quality of life improves similarly after CABG in diabetics and nondiabetics are limited. We assessed long-term mortality and changes in quality of life (RAND-36 Health Survey) after CABG. Seventy-four of the 508 patients (14.6%) operated on in a single institution had a history of diabetes and were compared with nondiabetics. The RAND-36 Health Survey was used as an indicator of quality of life. Assessments were made preoperatively and repeated 1 and 12 years later. Thirty-day mortality was 2.7 versus 1.6 ( p = 0.511) in the diabetics and nondiabetics. One- and 10-year survival rates in the diabetics and nondiabetics were 94.6% versus 97.0% ( p = 0.287) and 63.5% versus 81.6% ( p < 0.001), respectively. After 1 year, diabetics improved significantly ( p < 0.005) in seven, and nondiabetics ( p < 0.001) in all eight RAND-36 dimensions. Despite an ongoing decline in quality of life over the 12-year follow-up, an improvement was maintained in four out of eight dimensions among diabetics and in seven dimensions among nondiabetics. Physical and mental component summary scores on the RAND-36 improved significantly ( p < 0.001) in both groups after 1 year, and at least slight improvement was maintained during the 12-year follow-up time. Diabetics have inferior long-term survival after CABG as compared with nondiabetics. They gain similar improvement of quality of life in 1 year after surgery, but they have a stronger decline tendency over the years.

Superoleophobic Slippery Lubricant-Infused Surfaces: Combining Two Extremes in the Same Surface.

The ability to create superoleophobic surfaces repellent toward low-surface-tension liquids is important for various applications, and has been recently demonstrated using re-entrant or doubly re-entrant microtopography. Liquid droplets on such surfaces feature composite liquid-solid-air interfaces, whereas composite liquid-lubricant-air interfaces would have potential for additional repellency. Here, the development of a novel slippery superoleophobic surface with low adhesion is demonstrated via combining doubly re-entrant microtopography with slippery lubricant-infused porous surfaces. This is realized by using 3D direct laser writing to fabricate doubly re-entrant micropillars with dedicated nanostructures on top of each pillar. The top nanostructures stabilize the impregnated slippery lubricant, while the re-entrant geometry of the micropillars prevents lubricant from spreading. The slippery layer reduces the adhesion of liquid to the pillars, as proved using scanning droplet adhesion microscopy (SDAM), while the doubly re-entrant micropillars make the surface superoleophobic. This novel interface combining two extremes, superoleophobicity and slippery lubricant-infused surface, is of importance for designing superoleophobic and superhydrophobic surfaces with advanced liquid repellent, anti-icing, or anti-fouling properties.

The effect of obesity on long-term survival and health-related quality of life after coronary artery bypass grafting: a 12-year follow-up.

OBJECTIVE: The proportion of obese patients undergoing coronary artery bypass graft (CABG) surgery is increasing. In this study, our main objective was to assess the effect of obesity on long-term mortality and changes in quality of life (QoL) after GABG. MATERIALS AND METHODS: Data of 508 patients who underwent isolated GABG were prospectively collected. RAND-36 Health Survey (RAND-36) was used as an indicator of QoL. BMI was used to assess obesity, and the analysis was based primarily on two patient groups: BMI less than 30 kg/m (408 patients) and BMI of at least 30 (100 patients). All assessments were made preoperatively and repeated 1 and 12 years after CABG surgery. The follow-up of the cohort was complete in 95 and 84% of the alive patients at 1 and 12 years, respectively. RESULTS: Thirty-day, 1-year, and 10-year survival rates were 99.0, 97.0, and 78.0%, respectively, in the obese and 98.0, 96.8, and 79.2%, respectively, in the nonobese group. Obese showed significant (P<0.05) improvements only in four and nonobese in seven of eight RAND-36 dimensions of QoL. In both obese and nonobese patients, improved RAND-36 physical component summary and mental component summary scores were seen in comparison with the preoperative values. Yet, obese patients had a more pronounced diminution in their physical component summary and mental component summary scores, whereas nonobese patients maintained their physical and mental health status better. CONCLUSION: Despite an on-going decline in 12 years after the CABG, both patient groups showed improvements in their health status in comparison with preoperative values. Obese patients gained less benefit in terms of QoL dimension, but there was no significant difference in overall mortality in the long-term follow-up.

Publisher Correction: Mapping microscale wetting variations on biological and synthetic water-repellent surfaces.

The original version of this Article contained an error in Fig. 2b. The y-axis label in Fig. 2b was incorrectly labelled 'Snap-in force (µN)'. In the correct version, the axis is labelled 'Snap-in force (nN)'. In the original version of this Article, the "Butterfly wings" section of the Methods incorrectly stated the name of the butterfly as 'Golden bird'. In the correct version, the name of the butterfly is 'Golden birdwing'. These have now been corrected in both the PDF and HTML versions of the article.

Mapping microscale wetting variations on biological and synthetic water-repellent surfaces.

Droplets slip and bounce on superhydrophobic surfaces, enabling remarkable functions in biology and technology. These surfaces often contain microscopic irregularities in surface texture and chemical composition, which may affect or even govern macroscopic wetting phenomena. However, effective ways to quantify and map microscopic variations of wettability are still missing, because existing contact angle and force-based methods lack sensitivity and spatial resolution. Here, we introduce wetting maps that visualize local variations in wetting through droplet adhesion forces, which correlate with wettability. We develop scanning droplet adhesion microscopy, a technique to obtain wetting maps with spatial resolution down to 10 µm and three orders of magnitude better force sensitivity than current tensiometers. The microscope allows characterization of challenging non-flat surfaces, like the butterfly wing, previously difficult to characterize by contact angle method due to obscured view. Furthermore, the technique reveals wetting heterogeneity of micropillared model surfaces previously assumed to be uniform.

The long-term effect of perioperative myocardial infarction on health-related quality-of-life after coronary artery bypass grafting.

OBJECTIVES: To evaluate the long-term effect of perioperative myocardial infarction (PMI) on outcomes and health-related quality-of-life (QOL) after coronary artery bypass grafting (CABG). METHODS: Eighty of the 501 patients (16%) fulfilled electrocardiogram or cardiac enzyme criteria for PMI and were compared with patients with no PMI. The RAND-36 Health Survey was used as an indicator of QOL. Assessments were made preoperatively and repeated 1 year and 12 years later. RESULTS: Thirty-day mortality was adversely affected by PMI (6.3 vs 1.0%, P = 0.001). One-year survival rates for PMI and no-PMI patients were 92.5 and 97.6%, 10-year rates being 72.5 and 79.8%. One year after the surgery, PMI patients improved in seven and no-PMI patients in all the eight RAND-36 dimensions. In the 12-year follow-up, the scores showed a general decline tendency. PMI patients still maintained a significant improvement in four and no-PMI patients in seven of eight dimensions when compared with the baseline scores. A highly significant improvement was seen in the RAND-36 mental and physical component summary scores in the no-PMI group 1 year after CABG. PMI patients improved also significantly although the magnitude of change was lower. In the 12-year follow-up, there was a general decline tendency in the scores. Both groups showed similar freedom from anginal symptoms at 12 years. CONCLUSIONS: Although PMI has a negative impact on health-related QOL 1 year after CABG, this effect is only minor in the long term. PMI increases 30-day mortality but shows no effect on later mortality.

A 12-year follow-up on the changes in health-related quality of life after coronary artery bypass graft surgery.

OBJECTIVES: Improvement in quality of life (QoL) and survival benefit are the primary objectives of coronary artery bypass graft (CABG) surgery. The profile of patients undergoing isolated CABG has altered towards higher age with more preoperative comorbidities. Thus, the importance of QoL over the quantity of life among elderly patients is getting more emphasized. In this study, our main goal was to evaluate the long-term changes in QoL, overall performance status and symptomatic status after the CABG. METHODS: Comprehensive data of 508 patients who underwent isolated CABG in a single institution were prospectively collected. The RAND-36 Health Survey (RAND-36) was used as an indicator of QoL. Karnofsky dependency category was used to evaluate overall performance status, and symptomatic status was assessed using New York Heart Association (NYHA) class. All assessment were made preoperatively and repeated 1 year and 12 years later. The follow-up of the study cohort was complete in 95 and 84% of the alive patients at 1 year and 12 years, respectively. Analysis was based mainly on three age groups: ≤64 years (282 patients), 65-74 years (175 patients) and ≥75 years (51 patients). RESULTS: Thirty-day, 1-year and 10-year survival rates were 98, 97 and 79%, respectively. Twelve years after the surgery significant improvement (P<0.05) was seen in all but one RAND-36 dimensions of the QoL (general health, P=0.76) as well as in functional capacity (P<0.001) and NYHA class. All age groups showed improvements in RAND-36 physical component summary (PCS) and mental component summary (MCS) scores compared with the preoperative values. The youngest subgroup maintained their physical and mental health status best, whereas older subgroups had more pronounced decreases in their PCS and MCS scores. CONCLUSIONS: Despite an ongoing deterioration 12 years after the CABG, there was significant improvement in most dimensions of the QoL and functional capacity in comparison with the preoperative values. The elderly gain less long-term benefit from CABG regarding the QoL and survival.

Quality of life 12 years after on-pump and off-pump coronary artery bypass grafting.

OBJECTIVE: To assess whether the use of either the on-pump or the off-pump method affects changes in health-related quality of life (QOL) in the long term after coronary artery bypass graft (CABG) surgery. METHODS: Four hundred and fifty-two (89.0%) of the 508 patients in a single institution were operated on-pump and 56 (11.0%) were operated off-pump. The RAND-36 Health Survey (RAND-36) was used as an indicator of QOL. Assessments were performed preoperatively and repeated 1 year and 12 years later. Symptomatic status was estimated according to New York Heart Association class. RESULTS: After 1 year, on-pump patients improved significantly (P<0.001) in all eight RAND-36 dimensions. Also, in off-pump patients, positive changes were observed in all RAND-36 dimensions and these changes were statistically significant (P<0.05) in six dimensions. Despite an ongoing decrease in QOL over the 12-year follow-up, on-pump patients still maintained a significant (P<0.05) improvement in all and off-pump patients in seven out of eight RAND-36 dimensions. A highly significant (P<0.001) pattern of change after 1 year was observed in the RAND-36 Mental Component Summary and Physical Component Summary scores in both operative groups, and despite the general declining trend, significant improvement was maintained during the 12-year follow-up time. Both groups showed almost identical relief from anginal symptoms at 12 years. CONCLUSION: A majority of patients experience significant improvement in health-related QOL in the long term after CABG. Cardiopulmonary bypass has no impact on patients' subsequent health-related QOL.