A new roughness length parameterization accounting for wind–wave (mis)alignment

Two-way feedback occurs between offshore wind and waves. However, the influence of the waves on the wind profile remains understudied, in particular the momentum transfer between the sea surface and the atmosphere. Previous studies showed that for swell waves it is possible to have increasing wind speeds in case of aligned wind–wave directions. However, the opposite is valid for opposed wind–wave directions, where a decrease in wind velocity is observed. Up to now, this behavior has not been included in most numerical models due to the lack of an appropriate parameterization of the resulting effective roughness length. Using an extensive data set of offshore measurements in the North Sea and the Atlantic Ocean, we show that the wave roughness length affecting the wind is indeed dependent on the alignment between the wind and wave directions. Moreover, we propose a new roughness length parameterization, taking into account the dependence on alignment, consisting of an enhanced roughness length for increasing misalignment. Using this new roughness length parameterization in numerical models might facilitate a better representation of offshore wind, which is relevant to many applications including offshore wind energy and climate modeling.</p

Challenges and perspectives of CRISPR-based technology for diagnostic applications

The precision and versatility of CRISPR-based techniques, combined with the advantages of nucleic acid-based nanotechnology, hold great promise in transforming the landscape of molecular diagnostics. While significant progress has been made, current CRISPR-based platforms primarly focus on nucleic acid detection. To expand the applicability and fully leverage the advantages offered by CRISPR-based diagnostics, ongoing efforts explore molecular strategies to develop CRISPR sensors capable of detecting a diverse range of analytes beyond nucleic acids. In addition, challenges still persist in the adaptation of CRISPR platforms for point-of-care (POC) applications, involving concerns such as portability and automation, as well as the complexities associated with multiplexing. Here, we provide a detailed classification and comprehensive discussion of molecular strategies facilitating the conversion of non-nucleic acid target binding into CRISPR-powered outputs with an emphasis on their corresponding design principles. Furthermore, the second part of the review outlines current challenges and potential solutions for seamlessly integrating these strategies into user-friendly platforms and rapid tests specifically tailored for point-of-care (POC)

Responsive Nucleic Acid-Based Organosilica Nanoparticles

The development of smart nanoparticles (NPs) that encode responsive features in the structural framework promises to extend the applications of NP-based drugs, vaccines, and diagnostic tools. New nanocarriers would ideally consist of a minimal number of biocompatible components and exhibit multiresponsive behavior to specific biomolecules, but progress is limited by the difficulty of synthesizing suitable building blocks. Through a nature-inspired approach that combines the programmability of nucleic acid interactions and sol–gel chemistry, we report the incorporation of synthetic nucleic acids and analogs, as constitutive components, into organosilica NPs. We prepared different nanomaterials containing single-stranded nucleic acids that are covalently embedded in the silica network. Through the incorporation of functional nucleic acids into the organosilica framework, the particles respond to various biological, physical, and chemical inputs, resulting in detectable physicochemical changes. The one-step bottom-up approach used to prepare organosilica NPs provides multifunctional systems that combine the tunability of oligonucleotides with the stiffness, low cost, and biocompatibility of silica for different applications ranging from drug delivery to sensing

Engineering DNA-grafted quatsomes as stable nucleic acid-responsive fluorescent nanovesicles

The development of artificial vesicles into responsive architectures capable of sensing the biological environment and simultaneously signaling the presence of a specific target molecule is a key challenge in a range of biomedical applications from drug delivery to diagnostic tools. Herein, the rational design of biomimetic DNA-grafted quatsome (QS) nanovesicles capable of translating the binding of a target molecule to amphiphilic DNA probes into an optical output is presented. QSs are synthetic lipid-based nanovesicles able to confine multiple organic dyes at the nanoscale, resulting in ultra-bright soft materials with attractiveness for sensing applications. Dye-loaded QS nanovesicles of different composition and surface charge are grafted with fluorescent amphiphilic nucleic acid-based probes to produce programmable FRET-active nanovesicles that operate as highly sensitive signal transducers. The photophysical properties of the DNA-grafted nanovesicles are characterized and the highly selective, ratiometric detection of clinically relevant microRNAs with sensitivity in the low nanomolar range are demonstrated. The potential applications of responsive QS nanovesicles for biosensing applications but also as functional nanodevices for targeted biomedical applications is envisaged

Exposure to UV radiance predicts repeated evolution of concealed black skin in birds

Plumage is among the most well-studied components of integumentary colouration. However, plumage conceals most skin in birds, and as a result the presence, evolution and function of skin colour remains unexplored. Here we show, using a database of 2259 species encompassing >99% of bird genera, that melanin-rich, black skin is found in a small but sizeable percentage (~5%) of birds, and that it evolved over 100 times. The spatial distribution of black skin follows Gloger's rule, which states that pigmentation of endothermic animals increases towards the equator. Furthermore, most black-skinned birds inhabit high irradiation regions, and tend to be bald and/or have white feathers. Thus, taken together, our results suggest that melanin-rich, black skin helps to protect birds against ultraviolet irradiation. More generally, our results illustrate that feathered skin colour varies taxonomically, ontogenetically and temporally, providing an additional dimension for avian colour research.status: publishe

Can a metal nanoparticle based catalyst drive the selective growth of bright SiV color centers in CVD diamonds ?

We propose an efficient catalytic method based on nickel nanoparticles to produce a massive amount of Si color centers in diamonds directly during the CVD growth. A thermodynamic model was firstly developed to describe the mechanism of the Si inclusion in diamonds and a subsequent series of diamond syntheses was carried out to corroborate the model. Raman and photoluminescence spectroscopy as well as electron microscopy were used to characterize the diamond samples. All the treatments with Ni nanoparticles were able to produce diamond samples with a Si related fluorescence intensity higher than the one related to the un-treated samples. Finally a critical discussion of our results, in comparison with the ones reported in literature, is presented. 1. Introductio

Can a metal nanoparticle based catalyst drive the selective growth of bright SiV color centers in CVD diamonds ?

We propose an efficient catalytic method based on nickel nanoparticles to produce a massive amount of Si color centers in diamonds directly during the CVD growth. A thermodynamic model was firstly developed to describe the mechanism of the Si inclusion in diamonds and a subsequent series of diamond syntheses was carried out to corroborate the model. Raman and photoluminescence spectroscopy as well as electron microscopy were used to characterize the diamond samples. All the treatments with Ni nanoparticles were able to produce diamond samples with a Si related fluorescence intensity higher than the one related to the un-treated samples. Finally a critical discussion of our results, in comparison with the ones reported in literature, is presented. 1. Introductio

Programmable RNA-based systems for sensing and diagnostic applications

The emerging field of RNA nanotechnology harnesses the versatility of RNA molecules to generate nature-inspired systems with programmable structure and functionality. Such methodology has therefore gained appeal in the fields of biosensing and diagnostics, where specific molecular recognition and advanced input/output processing are demanded. The use of RNA modules and components allows for achieving diversity in structure and function, for processing information with molecular precision, and for programming dynamic operations on the grounds of predictable non-covalent interactions. When RNA nanotechnology meets bioanalytical chemistry, sensing of target molecules can be performed by harnessing programmable interactions of RNA modules, advanced field-ready biosensors can be manufactured by interfacing RNA-based devices with supporting portable platforms, and RNA sensors can be engineered to be genetically encoded allowing for real-time imaging of biomolecules in living cells. In this article, we report recent advances in RNA-based sensing technologies and discuss current trends in RNA nanotechnology-enabled biomedical diagnostics. In particular, we describe programmable sensors that leverage modular designs comprising dynamic aptamer-based units, synthetic RNA nanodevices able to perform target-responsive regulation of gene expression, and paper-based sensors incorporating artificial RNA networks