Spider silk as a blueprint for greener materials : a review

Spider silk exhibits remarkable properties, especially its well-known tensile performances. They rely on a complex nanostructured hierarchical organisation that studies progressively elucidate. Spider silk encompasses a vast range of fibres that exhibit diverse and captivating physical and biological characteristics. The full understanding of the relation between structure and properties may lead in the future to the design of a variety of high-performance, tailored materials and devices. Reknown for being produced in mild and benign conditions, this outstanding biological material constitutes one of the more representative example of biomimetism. In addition, silk’s structure is produced with limited means, i.e. low energy and relatively simple renewable constituents (silk proteins). Then, if successfully controlled and adequately transposed in biomaterials, some properties of natural silk could lead to innovative green materials that may contribute to reduce the ecological footprint of societies. In fact, striking recent advanced applications made with B. mori silk suggest that spider silk-based materials may lead to advanced resistant and functional materials, then becoming among the most promising subject of study in material science. However, several challenges have to be overcome, especially our ability to produce native-like silk, to control biomaterials’ structure and properties and to minimise their ecological footprint. This paper reviews the characteristics of spider silk that make it so attractive and that may (or may not) contribute to reduce ecological footprint of materials and the challenges in producing innovative spider silk-based materials. First, from a biomimetic perspective, the structure and models that explain the tensile resistance of natural silk are presented, followed by the state of knowledge regarding natural silk spinning process and synthetic production methods. Biocompatibility (biosafety and biofunctionality) as well as biodegradability issues are then addressed. Finally, examples of applications are reviewed. Features that may lead to the design of green materials are emphasised throughout

Worldwide Linke turbidity information

International audienceThis paper describes the algorithms and data used to construct a worldwide Linke turbidity factor (TL, for an air mass equal to 2)database. Two main steps had to be performed to obtain the information: 1. Assembling estimates of TL and 2. fusing different background layers for the construction of the TL maps. The estimates of TL have two forms: either they stand for specific geographical locations and have a high accuracy, or they are available as gridded data averaged over large areas. Point information was gathered from measured time series of hourly beam and daily global radiation, which were transformed to TL. From publications and networks like AERONET other turbidity quantities were obtained and transformed to TL. The basic gridded data are the maps of daily global irradiation supplied by the NASA-Langley Research Center. The included monthly clear sky irradiations were converted to TL with the same method as for the ground sites. Further gridded information was taken from NOAA pathfinder aerosol data and NASA NVAP. An algorithm was devised to fuse these two types of data and to produce gridded maps in a canonical projection and 5' arc angle cells. These final maps should reproduce the values observed at specific locations. The root mean square error of the interpolation is 0.73 TL units

Fusing ground measurements and satellite-derived products for the construction of climatological maps in atmosphere optics

International audienceClimatological maps (gridded data) of optical parameters of the atmosphere often result from application of numerical models or processing of satellite images. Such maps usually exhibit very large cell sizes, of the order of 1 of arc angle. There is a need to increase their spatial resolution to obtain a cell size closer to the spatial representation obtained by standard meteorological instruments at ground level, i.e. 5' of arc angle. It then permits to fuse ground measurements and gridded data, especially to correct for bias ob- served in gridded data. Taking advantage of the availability of other data sets of relevance to the parameter under concern, though different, a method is proposed for the synthesis of the initial gridded data at a higher resolution by the means of a fusion process. This paper describes the method with an application for the con- struction of worldwide maps of the Linke turbidity factor with cells of 5' in size. This factor characterises the atmospheric optical turbidity under clear skies and is a very important parameter in solar radiation studies

Using infrared and raman microspectroscopies to compare ex vivo involved psoriatic skin with normal human skin

Psoriasis is a chronic dermatosis that affects around 3% of the world’s population. The etiology of this autoimmune pathology is not completely understood. The barrier function of psoriatic skin is known to be strongly altered, but the structural modifications at the origin of this dysfunction are not clear. To develop strategies to reduce symptoms of psoriasis or adequate substitutes for modeling, a deep understanding of the organization of psoriatic skin at a molecular level is required. Infrared and Raman microspectroscopies have been used to obtain direct molecular-level information on psoriatic and healthy human skin biopsies. From the intensities and positions of specific vibrational bands, the lipid and protein distribution and the lipid order have been mapped in the different layers of the skin. Results showed a similar distribution of lipids and collagen for normal and psoriatic human skin. However, psoriatic skin is characterized by heterogeneity in lipid/protein composition at the micrometer scale, a reduction in the definition of skin layer boundaries and a decrease in lipid chain order in the stratum corneum as compared to normal skin. A global decrease of the structural organization is exhibited in psoriatic skin that is compatible with an alteration of its barrier properties

Transdermal diffusion, spatial distribution and physical state of a potential anticancer drug in mouse skin as studied by diffusion and spectroscopic techniques

Background:Understanding the efficiency of a transdermal medical drug requires the characterization of its diffusion process, including its diffusion rate, pathways and physical state. Objective:The aim of this work is to develop a strategy to achieve this goal. Methods:FTIR spectroscopic imaging in conjunction with a Franz cell and HPLC measurements were used to examine the transdermal penetration of deuterated tert-butyl phenylchloroethylurea (tBCEU), a molecule with a potential anticancer action. tBCEU has been solubilized in an expedient solvent mixture and its diffusion in hairless mouse skin has been studied. Results:The results indicate that tBCEU diffuses across the skin for more than 10 hours with a rate comparable to selegiline, an officially-approved transdermal drug. IR image analyses reveal that after 10 hours, tBCEU penetrates skin and that its spatial distribution does not correlate with neither the distribution of lipids nor proteins. tBCEU accumulates in cluster domains but overall low concentrations are found in skin. FTIR spectroscopic imaging additionally reveals that tBCEU is in a crystalline form. Conclusions:The results suggest that tBCEU is conveyed through the skin without preferential pathway. FTIR spectroscopic imaging and transdermal diffusion measurements appear as complementary techniques to investigate drug diffusion in skin

TAVI: Simplification Is the Ultimate Sophistication

Since its introduction in 2002, TAVI has evolved dramatically and is now standard of care for intermediate risk patients when the femoral approach can be implemented safely. The development of innovative transcatheter heart valves (THVs) and refinement of technical skills have contributed to the decrease in complication rates associated with TAVI4. Increased experience, smaller sheaths, rigorous pre-procedural planning and improved vascular closing techniques have resulted in markedly lower rates of vascular complications. The next step is the simplification of the procedure, which should contribute to a further decrease in complications, and also reduce procedural time, hospital stay as well as staff workload and costs. Moving to conscious sedation, no predilatation, no temporary pace maker and use of the radial approach as the contralateral approach are all instrumental in achieving this ultimate refinement

Loss of Life Expectancy related to temporal evolution of PM2.5 considered within energy scenarios in Europe

International audiencePeople exposure to particulate matter can have various health effects as described in scientific publications in the area of observational epidemiology. This study estimates the Loss of Life Expectancy (LLE) related to PM2.5 concentrations corresponding to a selected baseline energy scenario derived from the GAINS model. Most often energy scenarios are defined as consistent pathways towards a long-term target defined by a set of criteria that describe a sustainable energy supply. This study accounts for the temporal evolution of PM2.5 concentrations along the time frame from 2005 till 2050. The analysis was carried out for 43 European countries with a spatial resolution of 50 x 50 km. LLE was considered over the whole life time of the population older than 30 years in year 2005. We propose an algorithm for the computation of LLE for population exposed to PM2.5 based on the approach recommended by the Task Force on Health described in IIASA's Report and accounting for the Pope exposure-risk parameter. The LLE computation is based on the difference between the life expectancy with no exposure to particulates and life expectancy with exposure to observed particulates. We considered in our algorithm the temporal evolutions of PM2.5 concentrations along the scenario, as well as population densities. LLE results were derived using different PM2.5 concentration profiles from 2005 to 2050. The first PM2.5 concentration profile corresponds to a constant PM2.5 concentration with values fixed to the 2005 situation. The second PM2.5 concentration profile corresponds to the temporal evolution of the selected energy scenario. LLE is then derived for both situations: the fixed PM2.5 concentrations case and the variable PM2.5 case as defined for the baseline scenario. LLE results are significantly different between the two cases with a decrease by half for most European countries. The Netherlands and Eastern Europe are the only regions where LLE exceed 300 days/person of life lost. Applying this new feature of temporal evolution of PM2.5 is of interest for assessing the potential impacts of scenarios accounting for the possible technical evolution of energy pathways. Results are provided on line in numerical form as well as in form of LLE maps

When a Master of Sciences on EdTech becomes an International Community

International audienceThe MSc SmartEdTech program at Université Côte d’Azur aims to develop a quality approach to digital education with a co-creative and participative education. The program is embedded within a socioeconomic sensibility, specifically related to the ​ Global Goals of the United Nations in relation to education​. The challenge is to both improve today's education and create tomorrow’s education, by means of breakthrough digital pedagogies. Perhaps the most interesting and motivating aspect of this experience is the way in which this tiny, lively, global group has started to form a multicultural, interdisciplinary and international community, with a common objective, sharing ideas and practices, being

072 Five-year outcome of patients with bifurcation lesions treated with provisional side branch T-stenting using drug-eluting stents

BackgroundCoronary bifurcation lesions remain a challenge, as lower success rates and higher reintervention rates persist in this lesion subset. The ideal strategy to treat such lesions is still debated and data regarding long-term efficacy and safety of drug-eluting stents in this setting are sparse.ObjectivesWe sought to determine the long-term efficacy and safety of a provisional side branch T-stenting (PTS) strategy for bifurcation lesions in an unselected population.Methods477 consecutive Pts were treated for bifurcation lesions with DES (Paclitaxel or Sirolimus-eluting stents) between 2003 and 2005. Data were entered prospectively into a single-center registry. The PTS strategy was employed in 92%, with a side-branch stent in 28% and final kissing balloon inflation in 95%. Five-year follow-up, at a median of 61 months, is available for 93.5% of patients.ResultsAngiographic success was achieved in 99%, with 2.5% in-hospital major adverse cardiac events (MACE, defined as any cardiac death, early reintervention, Q – or non-Q-wave MI or target vessel revascularisation). The cumulative rate of MACE was 10.7% at 1 year, 13.6% at 2 years and 19.7% at 5 years, including target vessel revascularisation rates of 6.9%, 8.9% and 13%, and cardiac death rates of 3%, 3.7% and 6.7%, respectively. Ischaemia-driven target lesion revascularisation at 5 years is 7.3%. The cumulative rate of definite or probable stent thrombosis at long-term is 3.1%, most cases occurring within the first year (2.5%). The need for reintervention in the long-term was not predicted by any procedural variable, and not significantly related to the use of 1 or 2 stents or to the type of stent deployed.ConclusionsA PTS strategy with first generation drug-eluting stents, was applicable to over 90% of real-world patients with bifurcation lesions with a target lesion revascularisation < 10% at 5 years. The rate of very-late stent thrombosis in this complex lesion subset remains low