Template-Directed Synthesis of Strained meso-meso-Linked Porphyrin Nanorings.

Strained macrocycles display interesting properties, such as conformational rigidity, often resulting in enhanced π-conjugation or enhanced affinity for non-covalent guest binding, yet they can be difficult to synthesize. Here we use computational modeling to design a template to direct the formation of an 18-porphyrin nanoring with direct meso-meso bonds between the porphyrin units. Coupling of a linear 18-porphyrin oligomer in the presence of this template gives the target nanoring, together with an unexpected 36-porphyrin ring by-product. Scanning tunneling microscopy (STM) revealed the elliptical conformations and flexibility of these nanorings on a Au(111) surface.

Molecular Diffusion and Self-Assembly: Quantifying the Influence of Substrate hcp and fcc Atomic Stacking.

Molecular diffusion is a fundamental process underpinning surface-confined molecular self-assembly and synthesis. Substrate topography influences molecular assembly, alignment, and reactions with the relationship between topography and diffusion linked to the thermodynamic evolution of such processes. Here, we observe preferential adsorption sites for tetraphenylporphyrin (2H-TPP) on Au(111) and interpret nucleation and growth of molecular islands at these sites in terms of spatial variation in diffusion barrier driven by local atomic arrangements of the Au(111) surface (the 22× âˆš3 "herringbone" reconstruction). Variable-temperature scanning tunnelling microscopy facilitates characterization of molecular diffusion, and Arrhenius analysis allows quantitative characterization of diffusion barriers within fcc and hcp regions of the surface reconstruction (where the in-plane arrangement of the surface atoms is identical but the vertical stacking differs). The higher barrier for diffusion within fcc locations underpins the ubiquitous observation of preferential island growth within fcc regions, demonstrating the relationship between substrate-structure, diffusion, and molecular self-assembly.

Looking towards objective quality evaluation in colonoscopy: Analysis of visual gaze patterns.

BACKGROUND AND AIM: There are currently limited training and assessment tools available to novice endoscopists. A potential tool for the objective assessment of endoscopist visual search strategy is eye-tracking technology. The aim of this study is to assess whether eye-tracking technology can be used to differentiate the visual gaze patterns (VGP) of experienced and novice endoscopists, and to characterize any differences arising between the two groups. METHOD: With the use of portable eye-tracking glasses, VGP of novice (n = 20) and experienced (n = 14) endoscopists were compared while viewing a colonoscopy withdrawal through the hepatic flexure. Analysis was performed by comparing the central versus peripheral distribution and the horizontal distribution of novice and experienced endoscopist fixations, along with comparison of basic eye-tracking metrics. RESULTS: This study found that experienced endoscopists had a significantly higher percentage of fixations within the periphery of the screen (13.4% vs 23.0%, P = 0.013). Experienced endoscopists also had a significantly greater percentage of fixations on the left side of the screen (18.6% vs 33.5%, P = 0.005) that displayed the poorly visualized "inside bend" of the hepatic flexure. CONCLUSION: This study has detailed specific VGP acquired through expertise, which can potentially explain why adenomas are regularly missed at the hepatic flexure during colonoscopy. These may be useful for the training of novice colonoscopists, and further validation may utilize VGP in the development of an objective proficiency based curriculum to improve the detection of pathology and overall quality in endoscopy.

Porphyrin-fused graphene nanoribbons.

Graphene nanoribbons (GNRs), nanometre-wide strips of graphene, are promising materials for fabricating electronic devices. Many GNRs have been reported, yet no scalable strategies are known for synthesizing GNRs with metal atoms and heteroaromatic units at precisely defined positions in the conjugated backbone, which would be valuable for tuning their optical, electronic and magnetic properties. Here we report the solution-phase synthesis of a porphyrin-fused graphene nanoribbon (PGNR). This PGNR has metalloporphyrins fused into a twisted fjord-edged GNR backbone; it consists of long chains (>100 nm), with a narrow optical bandgap (~1.0 eV) and high local charge mobility (>400 cm2 V-1 s-1 by terahertz spectroscopy). We use this PGNR to fabricate ambipolar field-effect transistors with appealing switching behaviour, and single-electron transistors displaying multiple Coulomb diamonds. These results open an avenue to π-extended nanostructures with engineerable electrical and magnetic properties by transposing the coordination chemistry of porphyrins into graphene nanoribbons.

Team Immediate Meet tool to help intensive care staff: Staff perception of an updated version and preliminary feedback following implementation.

Intensive Care Unit staff deal with potentially traumatic cases throughout their careers. We designed and implemented a 'Team Immediate Meet' (TIM) tool, a communication aid designed to facilitate a two-minute 'hot debrief' after a critical event, provide the team with information about the normal reaction to such an event and signpost staff to strategies to help support their colleagues (and themselves). We describe our TIM tool awareness campaign, quality improvement project and subsequent feedback from staff who reported that the tool would be useful for navigating the aftermath of potentially traumatic events and could be transferable to other ICUs.

Order, disorder, and metalation of tetraphenylporphyrin (2H-TPP) on Au(111).

A thermally induced order-disorder transition of tetraphenylporphyrin (2H-TPP) on Au(111) is characterised by scanning probe microscopy and X-ray photoelectron spectroscopy-based techniques. We observed that a transition from an ordered close-packed phase to a disordered diffuse phase is correlated with an on-surface cyclodehydrogenation reaction, and that additional heating of this diffuse phase gives rise to a single distinct nitrogen environment indicative of the formation of a Au-TPP species.

Identification of outcomes to inform the development of a core outcome set for surgical innovation: a targeted review of case studies of novel surgical devices.

OBJECTIVE: Outcome selection and reporting in studies of novel surgical procedures and devices lacks standardisation, hindering safe and effective evaluation. A core outcome set (COS) to measure and report in all studies of surgical innovation is needed. We explored outcomes in a specific sample of innovative surgical device case studies to identify outcome domains specifically relevant to innovation to inform the development of a COS. DESIGN: A targeted review of 11 purposive selected case studies of innovative surgical devices. METHODS: Electronic database searches in PubMed (July 2018) identified publications reporting the introduction and evaluation of each device. Outcomes were extracted and categorised into domains until no new domains were conceptualised. Outcomes specifically relevant to evaluating innovation were further scrutinised. RESULTS: 112 relevant publications were identified, and 5926 outcomes extracted. Heterogeneity in study type, outcome selection and reporting was observed across surgical devices. Categorisation of outcomes was performed for 2689 (45.4%) outcomes into five broad outcome domains. Outcomes considered key to the evaluation of innovation (n=66; 2.5%) were further categorised as surgeon/operator experience (n=40; 1.5%), unanticipated events (n=15, 0.6%) and modifications (n=11; 0.4%). CONCLUSION: Outcome domains unique to evaluating innovative surgical devices have been identified. Findings have been combined with multiple other data sources relevant to the evaluation of surgical innovation to inform the development of a COS to measure and report in all studies evaluating novel surgical procedures/devices.

Registration and publication of emergency and elective randomised controlled trials in surgery: a cohort study from trial registries.

OBJECTIVES: Emergency surgical practice constitutes 50% of the workload for surgeons, but there is a lack of high quality randomised controlled trials (RCTs) in emergency surgery. This study aims to establish the differences between the registration, completion and publication of emergency and elective surgical trials. DESIGN: The clinicaltrials.gov and ISRCTN.com trials registry databases were searched for RCTs between 12 July 2010 and 12 July 2012 using the keyword 'surgery'. Publications were systematically searched for in Pubmed, MEDLINE and EMBASE. PARTICIPANTS: Results with no surgical interventions were excluded. The remaining results were manually categorised into 'emergency' or 'elective' and 'surgical' or 'adjunct' by two reviewers. PRIMARY OUTCOME MEASURES: Number of RCTs registered in emergency versus elective surgery. SECONDARY OUTCOME MEASURES: Number of RCTs published in emergency versus elective surgery; reasons why trials remain unpublished; funding, sponsorship and impact of published articles; number of adjunct trials registered in emergency and elective surgery. RESULTS: 2700 randomised trials were registered. 1173 trials were on a surgical population and of these, 414 trials were studying surgery. Only 9.4% (39/414) of surgical trials were in emergency surgery. The proportion of trials successfully published did not significantly differ between emergency and elective surgery (0.46 vs 0.52; mean difference (MD) -0.06, 95% CI -0.24 to 0.12). Unpublished emergency surgical trials were statistically equally likely to be terminated early compared with elective trials (0.33 vs 0.16; MD -0.18, 95% CI -0.06 to 0.41). Low accrual accounted for a similar majority in both groups (0.43 vs 0.46; MD -0.04, 95% CI -0.48 to 0.41). Unpublished trials in both groups were statistically equally likely to still be planning publication (0.52 vs 0.71; MD -0.18, 95% CI -0.43 to 0.07). CONCLUSION: Fewer RCTs are registered in emergency than elective surgery. Once trials are registered both groups are equally likely to be published.

Variations and adaptations of associated liver partition and portal vein ligation for staged hepatectomy (ALPPS): Many routes to the summit.

BACKGROUND: Our aim was to review variations from the originally described associated liver partition and portal vein ligation for staged hepatectomy (ALPPS) procedure and relevant clinical outcomes. METHODS: A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (ie, PRISMA) guidelines. A search of PubMed and Google Scholar was conducted until March 2015. Inclusion criteria were any publications reporting technical variations and descriptions of ALPPS. Exclusion criteria were insufficient technical description, data repeated elsewhere, or data that could not be accessed in English. RESULTS: Initial search results returned 790 results; 46 studies were included in the final qualitative analysis. There were several alternatives described to the first stage of complete parenchymal split. Variations included partial ALPPS (partial split; hypertrophy of future liver remnant [FLR] 80-90%), radiofrequency-assisted liver partition and portal vein ligation (mean FLR hypertrophy 62%), laparoscopic microwave ablation and portal vein ligation (FLR hypertrophy 78-90%), associating liver tourniquet and portal ligation for staged hepatectomy (median FLR hypertrophy 61%), and sequential associating liver tourniquet and portal ligation for staged hepatectomy (FLR hypertrophy 77%) with a potential decrease in morbidity particularly after stage I. We analyzed several other variations, including considerations for segment IV, operative maneuvers, use of laparoscopy, identification of biliary complications, and liver containment. CONCLUSION: The current literature demonstrates a large variability in techniques of ALPPS that limits meaningful statistical comparisons of outcomes. Not physically splitting the liver at the first stage may decrease morbidity; however, randomized controlled trials are needed to determine benefits in technical variations.

Anesthesia, surgical stress, and "long-term" outcomes.

An increasing body of evidence shows that the choice of anesthetic can strongly influence more than simply the quality of anesthesia. Regional and general anesthesia have often been compared to ascertain whether one provides benefits through dampening the stress response or harms by accelerating cancer progression. Regional anesthesia offers considerable advantages, by suppressing cortisol and catecholamine levels and reducing muscle breakdown postoperatively. It also has less immunosuppressive effect and potentially reduces the proinflammatory cytokine response. As such, vital organ functions (e.g., brain and kidney) may be better preserved with regional anesthetics, however, further study is needed. Volatile general anesthetics appear to promote cancer malignancy in comparison to regional and intravenous general anesthetics, and reduce the body's ability to act against cancer cells by suppression of natural killer cell activity. There is not sufficient evidence to support an alteration of current clinical practice, however, further research into this area is warranted due to the potential implications elicited by current studies.