Retraction of cutaneous specimens: tumours and margins after surgical excision

AimsIn previous studies, skin retraction of dermato-pathological specimens after the surgical excision of tumours was calculated at 30% for the surface, with approximately 20% for the length and 15% for the width. The aim of this study was to analyse the retraction of the specimens and the retraction of the lesion and the margins.MethodsPatients who underwent excision of a skin tumour between January 2013 and July 2014 were randomly included.ResultsA total of 104 patients was included. There were 52% male with a mean age of 68.3 years. Seventy-eight per cent of the lesions were malignant (51% were basal cell carcinoma, 10% squamous cell carcinoma). The retraction of the area of the specimen (29%) was significantly greater than the retraction of the tumour (21%). On multivariate analysis, the localisation and the duration of fixation were independent predictors of the specimen area retraction. The retraction of the specimen was 17% in length and 15% in width. The retraction of the margins was calculated at 19% in length and 12% in width. The surgeon correctly evaluated the localisation of the smallest margin in 55% of cases.ConclusionsOur study provided additional data regarding the retraction of the tumours and margins. The guidelines for surgical excision of skin cancers recommend a clinical margin before excision, but the evaluation of the sufficiency of the margins is based on histological measurement. Our data are useful for the interpretation of the sufficiency of the margins.

Spatial and temporal variability of benthic primary production in upwelling-influenced Colombian Caribbean coral reefs

In Tayrona National Natural Park (Colombian Caribbean), abiotic factors such as light intensity, water temperature, and nutrient availability are subjected to high temporal variability due to seasonal coastal upwelling. These factors are major drivers controlling coral reef primary production. This offers the opportunity to assess the effects of abiotic factors on key coral reef ecosystem services in terms of productivity. We therefore quantified primary net (Pn) and gross production (Pg) of the dominant local primary producers (scleractinian corals, macroalgae, algal turfs, crustose coralline algae, and microphytobenthos) at a water current/wave-exposed (EXP) and -sheltered (SHE) site in an exemplary bay of Tayrona National Natural Park. A series of short-term incubations was conducted to quantify O2 fluxes of the different primary producers before and at the end of the upwelling event 2011/2012. At the level of the organism, scleractinian corals showed highest Pn and Pg rates before upwelling (16 and 19 mmol O2 m-2 specimen area h-1), and corals and algal turfs dominated the primary production at the end of upwelling (12 and 19 mmol O2 m-2 specimen area h-1, respectively). At the ecosystem level, corals contributed most to total Pn (EXP: 81 %; SHE: 65 %) and Pg (EXP: 78 %; SHE: 55 %) before the upwelling, while at the end of the upwelling, corals contributed most to Pn and Pg only at EXP (73 and 75 %) and macroalgae at SHE (52 and 46 %, respectively). Despite the significant spatial and temporal differences in individual productivity of investigated groups and their different contribution to reef productivity, no spatial or temporal differences in daily ecosystem Pn and Pg were detected (194 – 218 and 311 – 409 mmol O2 m-2 seafloor area d-1). Our findings therefore indicate that local autotrophic benthic reef communities are well adapted to pronounced fluctuations of environmental key parameters. This might lead to a higher resilience against climate change consequences and anthropogenic disturbances.

Spatial and temporal variability of benthic primary production in upwelling-influenced Colombian Caribbean coral reefs

In Tayrona National Natural Park (Colombian Caribbean), abiotic factors such as light intensity, water temperature, and nutrient availability are subjected to high temporal variability due to seasonal coastal upwelling. These factors are major drivers controlling coral reef primary production. This offers the opportunity to assess the effects of abiotic factors on key coral reef ecosystem services in terms of productivity. We therefore quantified primary net (Pn) and gross production (Pg) of the dominant local primary producers (scleractinian corals, macroalgae, algal turfs, crustose coralline algae, and microphytobenthos) at a water current/wave-exposed (EXP) and -sheltered (SHE) site in an exemplary bay of Tayrona National Natural Park. A series of short-term incubations was conducted to quantify O2 fluxes of the different primary producers before and at the end of the upwelling event 2011/2012. At the level of the organism, scleractinian corals showed highest Pn and Pg rates before upwelling (16 and 19 mmol O2 m-2 specimen area h-1), and corals and algal turfs dominated the primary production at the end of upwelling (12 and 19 mmol O2 m-2 specimen area h-1, respectively). At the ecosystem level, corals contributed most to total Pn (EXP: 81 %; SHE: 65 %) and Pg (EXP: 78 %; SHE: 55 %) before the upwelling, while at the end of the upwelling, corals contributed most to Pn and Pg only at EXP (73 and 75 %) and macroalgae at SHE (52 and 46 %, respectively). Despite the significant spatial and temporal differences in individual productivity of investigated groups and their different contribution to reef productivity, no spatial or temporal differences in daily ecosystem Pn and Pg were detected (194 – 218 and 311 – 409 mmol O2 m-2 seafloor area d-1). Our findings therefore indicate that local autotrophic benthic reef communities are well adapted to pronounced fluctuations of environmental key parameters. This might lead to a higher resilience against climate change consequences and anthropogenic disturbances.

Atomic-Scale Measurement of Structure and Chemistry of a Single-Unit-Cell Layer of LaAlO3 Embedded in SrTiO3

A single layer of LaAlO3 with a nominal thickness of one unit cell, which is sandwiched between a SrTiO3 substrate and a SrTiO3 capping layer, is quantitatively investigated by high-resolution transmission electron microscopy. By the use of an aberration-corrected electron microscope and by employing sophisticated numerical image simulation procedures, significant progress is made in two aspects. First, the structural as well as the chemical features of the interface are determined simultaneously on an atomic scale from the same specimen area. Second, the evaluation of the structural and chemical data is carried out in a fully quantitative way on the basis of the absolute image contrast, which has not been achieved so far in materials science investigations using high-resolution electron microscopy. Considering the strong influence of even subtle structural details on the electronic properties of interfaces in oxide materials, a fully quantitative interface analysis, which makes positional data available with picometer precision together with the related chemical information, can contribute to a better understanding of the functionality of such interfaces.