Versatile and Efficient Site‐Specific Protein Functionalization by Tubulin Tyrosine Ligase

A novel chemoenzymatic approach for simple and fast site‐specific protein labeling is reported. Recombinant tubulin tyrosine ligase (TTL) was repurposed to attach various unnatural tyrosine derivatives as small bioorthogonal handles to proteins containing a short tubulin‐derived recognition sequence (Tub‐tag). This novel strategy enables a broad range of high‐yielding and fast chemoselective C‐terminal protein modifications on isolated proteins or in cell lysates for applications in biochemistry, cell biology, and beyond, as demonstrated by the site‐specific labeling of nanobodies, GFP, and ubiquitin.     

Correlating the Morphological Properties and Structural Organization of Monodisperse Spherical Silica Nanoparticles Grown on a Commercial Silica Surface

A variety of nanosilicas have been widely used to fabricate rough surfaces with superhydrophobic and superhydrophilic properties. In this context, we prepared mixed silica and mixed nanosilica that were generated by the growth and self‐assembly of synthesized monodisperse silica nanospheres (11–30 nm, 363 m² g^?1) on the surface of Sylopol‐948 and Dispercoll S3030 by using a base‐catalyzed sol–gel route. Using this process, the interactions and hierarchical structure between the nano‐ and microsized synthesized silica particles were studied by changing the amount of tetraethoxysilane. The resulting materials were characterized by BET analysis, small‐angle X‐ray scattering (SAXS), dynamic light scattering, FTIR spectroscopy, and SEM. The mixed silica presented a higher specific surface area (326 m² g^?1), a six‐fold higher percentage of (SiO)₆ (44–68 %), and a higher amount of silanol groups (14.0–30.7 %) than Sylopol‐948 (271 m² g^?1, 42.6 %, and 12.5 %, respectively). The morphological and hierarchical structural differences in the silica nanoparticles synthesized on the surface of commercial silica (micrometric or nanometric) were identified by SAXS. Mixed micrometric silica exhibited a higher degree of structural organization between particles than mixed nanosilica.     

Unveiling the nature of supramolecular crown ether–C60 interactions

A series of exTTF-(crown ether)₂ receptors, designed to host C₆₀, has been prepared. The size of the crown ether and the nature of the heteroatoms have been systematically changed to fine tune the association constants. Electrochemical measurements and transient absorption spectroscopy assisted in corroborating charge transfer in the ground state and in the excited state, leading to the formation of radical ion pairs featuring lifetimes in the range from 12 to 21 ps. To rationalize the nature of the exTTF-(crown ether)₂·C₆₀ stabilizing interactions, theoretical calculations have been carried out, suggesting a synergetic interplay of donor–acceptor, π–π, n–π and CH···π interactions, which is the basis for the affinity of our novel receptors towards C₆₀.     

Scaling the effects of surface topography in the secondary atomization resulting from droplet/wall interactions

The impact of droplets onto micro-structured surfaces has been the focus of numerous recent studies, under the perspective of many different applications. However, much is still to be known about the effects of surface patterning in order to devise realistic physical models to accurately predict interfacial transfer rates. In this context, the present paper addresses the question of how to scale the effects of the surface topography to find adequate parameters, which can be easily obtained a priori. The approach is based on the characterization of the hydrodynamic and thermal behaviors of individual droplets impacting onto smooth and micro-structured heated surfaces, with the objective of quantifying the effects of the modified wettability associated with the topography of the surface. The focus is put on the thermal-induced mechanisms of secondary atomization as these are of particular interest for spray-cooling applications. The analysis suggests that different wetting properties lead to particular characteristics of the thermal-induced atomization, which can be related with the ratio between the roughness amplitude and the fundamental wavelength of the surface topography R _a/λ_R. This hypothesis is consistent with the theoretical prediction of the wetting behavior of the surfaces. The results also show a good correlation between the mean sizes of the secondary droplets generated by thermal-induced atomization and the ratio R _a/λ_R.     

Transient analysis of intermittent multijet sprays

This paper analyzes the transient characteristics of intermittent sprays produced by the single-point impact of multiple cylindrical jets. The aim is to perform a transient analysis of the intermittent atomization process to study the effect of varying the number of impinging jets in the hydrodynamic mechanisms of droplet formation. The results evidence that hydrodynamic mechanisms underlying the physics of ligament fragmentation in 2-impinging jets sprays also apply to sprays produced with more than 2 jets during the main period of injection. Ligaments detaching from the liquid sheet, as well as from its bounding rim, have been identified and associated with distinct droplet clusters, which become more evident as the number of impinging jets increases. Droplets produced by detached ligaments constitute the main spray, and their axial velocity becomes more uniformly distributed with 4-impinging jets because of a delayed ligament fragmentation. Multijet spray dispersion patterns are geometric depending on the number of impinging jets. Finally, an analysis on the Weber number of droplets suggests that multijet sprays are more likely to deposit on interposed surfaces, thus becoming a promising and competitive atomization solution for improving spray cooling.     

Convex Quadratic Programming Approach to the Maximum Matching Problem

The problem of determining a maximum matching or whether there exists a perfect matching, is very common in a large variety of applications and as been extensively studied in graph theory. In this paper we start to introduce a characterisation of a family of graphs for which its stability number is determined by convex quadratic programming. The main results connected with the recognition of this family of graphs are also introduced. It follows a necessary and sufficient condition which characterise a graph with a perfect matching and an algorithmic strategy, based on the determination of the stability number of line graphs, by convex quadratic programming, applied to the determination of a perfect matching. A numerical example for the recognition of graphs with a perfect matching is described. Finally, the above algorithmic strategy is extended to the determination of a maximum matching of an arbitrary graph and some related results are presented.     

A kit of human polyclonal IgG for the diagnosis of infectious processes

The aim of this work was to obtain a freeze-dried kit for direct^99mTc-labeling of human polyclonal IgG. The labeling procedure was carried out by Schwarz's method. The best yields of^99mTc-IgG were obtained by using sodium pyrophosphate decahydrate as a weak chelating agent. Performed tests showed the stability of the radiopharmaceutical up to 24 hours. Plasma clearance in rats was fitted to a biexponential curve withT _1/2α=(0.1 ±0.9) h andT _1/2β=(10±3) h. The organs with higher uptake of radiopharmaceutical were lung, kidneys and blood. In a rabbit model the abscess target/background ratio was 3–6 according to time of the scintigraphic images. Thirty patients with musculoskeletal infection were studied. Twenty-one lesions were detected and confirmed by culture/biopsy.     

Radiography registration for mosaic tomography

A hybrid method of stitching X‐ray computed tomography (CT) datasets is proposed and the feasibility to apply the scheme in a synchrotron tomography beamline with micrometre resolution is shown. The proposed method enables the field of view of the system to be extended while spatial resolution and experimental setup remain unchanged. The approach relies on taking full tomographic datasets at different positions in a mosaic array and registering the frames using Fourier phase correlation and a residue‐based correlation. To ensure correlation correctness, the limits for the shifts are determined from the experimental motor position readouts. The masked correlation image is then minimized to obtain the correct shift. The partial datasets are blended in the sinogram space to be compatible with common CT reconstructors. The feasibility to use the algorithm to blend the partial datasets in projection space is also shown, creating a new single dataset, and standard reconstruction algorithms are used to restore high‐resolution slices even with a small number of projections.     

Chemical Composition and Antioxidant,Anti-Inflammatory,and Enzyme Inhibitory Activities of an Endemic Species from Southern Algeria: Warionia saharae

Warionia saharae Benth. & Coss. (Asteraceae) is an endemic species of North Africa naturally grown in the southwest of the Algerian Sahara. In the present study, this species’ hydromethanolic leaf extract was investigated for its phenolic profile characterized by ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS). Additionally, the chemical composition of W. saharae was analyzed by gas chromatography–mass spectrometry, and its antioxidant potential was assessed through five in vitro tests: DPPH^● scavenging activity, ABTS^●+ scavenging assay, galvinoxyl scavenging activity, ferric reducing power (FRP), and cupric reducing antioxidant capacity. The UHPLC-DAD-ESI/MS analysis allowed the detection and quantification of 22 compounds, with taxifolin as the dominant compound. The GC–MS analysis allowed the identification of 37 compounds, and the antioxidant activity data indicate that W. saharae extract has a very high capacity to capture radicals due to its richness in compounds with antioxidant capacity. The extract also showed potent α-glucosidase inhibition as well as a good anti-inflammatory activity. However, weak anti-α-amylase and anticholinesterase activities were recorded. Moreover, an in silico docking study was performed to highlight possible interactions between three significant compounds identified in W. saharae extract and α-glucosidase enzyme.