The atomic force microscope as a tool to study and manipulate local surface properties

The atomic force microscope (AFM), a prominent member of the new class of scanning near-field microscopes, has become a standard instrument to image the topography of surfaces with high resolution. In addition, the AFM is more and more used to study other local surface properties, like the local surface charge density, the surface energy, or viscoelastic properties. Beside its analytical capabilities, surfaces can be modified with the AFM tip. Examples of all three applications are given and future possibilities are discussed

Mode of birth in twins: data and reflections

Our primary objective was to compare neonatal and maternal outcomes in women with twin pregnancies, beyond 32 weeks, having a planned vaginal birth or a planned caesarean section (CS). This was a retrospective cohort study from a single tertiary centre over nine years. 534 sets of twins ≥32 + 0 weeks of gestation were included. 401 sets were planned vaginally and 133 sets were planned by CS. We compared a composite adverse perinatal outcome (perinatal mortality or serious neonatal morbidity; five minute APGAR score ≤4, neurological abnormality and need for intubation) and a composite maternal adverse outcome (major haemorrhage, trauma or infection) between the groups. There were no significant differences. Given the similarity of these results with several other larger studies of twin birth, we sought to look at reasons why there is still a rising rate of CS for twin births. We further make suggestions for keeping this rate to a sensible minimum.Impact statement What is already known on this subject? The largest randomised controlled study comparing planned vaginal birth with planned CSs for lower risk twins between 32 and 39 weeks of gestation, showed no added safety from planned CS. However, in most of the Western countries this conclusion has failed to increase the number of planned vaginal births for lower risk twins. What do the results of this study add? This observational study from a single tertiary centre provides external validation of the twin trial results in a practical day-to-day setting. It also provides insights as to how planned vaginal birth can be developed and maintained, with a key focus on safety and maternal participation in decision making. It does focus on consent and providing accurate data. What are the implications of these findings for clinical practice and/or further research? There are good grounds to encourage vaginal birth for low-risk twin pregnancies. The trend of rising caesarean rates in low-risk twin pregnancies worldwide will erode important skills for the conduct of vaginal births without any clear benefit for mothers or babies. The current situation demands careful thought about implementing innovative training opportunities for younger obstetricians. Finally, we need intelligent responses to many non-evidence-based factors which can drive clinical practice

The contribution of demographic, access and treatment-related factors on racial disparities in bladder cancer

Introduction & Objectives: There are race-based differences in bladder cancer survival. To better understand the factors contributing to this phenomenon, we designed a study to assess the statistical contribution of tumor, treatment and access to care on race-based differences in survival. Materials & Methods: Using the National Cancer Database, we extracted data on Black or White adults diagnosed with muscle invasive bladder cancer from 2004-2015. The impact of tumor, access and treatment on differences in survival was inferred by performing sequential propensity score-weighted analyses wherein Black and White patients were balanced with respect to (A)demographics and comorbidities (B)tumor characteristics (C)treatment and (D)access-related variables. To estimate the relative contribution of each group of variables, we calculated the propensity score-weighted hazard of death (Black v. White)after each iteration. The change in the hazard ratios were used to infer the relative contribution of each group of variables on the excess risk of death among Blacks. Results: We identified 44,577 patients with T1-4N0M0 bladder cancer, with a median follow up of 77 months. After balancing demographics and comorbidities, Black race was associated with 18% worse hazard of all-cause mortality (HR 1.18, 95% CI 1.12–1.25; p \u3c 0.001). Balancing by tumor characteristics reduced this to 16%, balancing by treatment reduced this to 10%, and balancing by access-related variables yielded no statistically significant difference in survival. In summary, access-related variables explained 40% (95% CI 22.9-57.0%)of the excess risk of death in Blacks, whereas treatment factors explained 35% (95% CI 22.2 – 46.9). The contribution of tumor characteristics was not significant. The results of each balancing procedure are shown in the attached Table. [Table Presented]Conclusions: In our models, differences in survival for Black and White patients with bladder cancer are best explained by disparities in access and treatment, not tumor characteristics. Initiatives to improve access to care (e.g. through improved insurance coverage and reduced barriers to urological care)may represent a key step in reducing racial disparities in bladder cancer outcomes