BINA

SignificanceA better understanding of diffusion reflection (DR) behavior may allow it to be used for more noninvasive applications, including the development of in vivo non-damaging techniques, especially for medical topical diagnosis and treatments.AimFor a bilayer opaque substance where the attenuation of the upper layer is larger than the attenuation of the lower layer, the DR crossover point () is location where the photons coming from the bottom layer start affecting the DR. We aim to study the dependency of the on absorption changes in different layers for constant scattering and top layer thickness.ApproachMonolayer and bilayer optical tissue-like phantoms were prepared and measured using a DR system. The results were compared with Monte Carlo simulations.ResultsThere is an agreement between the experiments and the simulations. correlates with the square root of the absorption coefficient ratio …

Raman spectroscopy is an extremely powerful laser-based method for characterizing materials based on their unique inelastic scattering spectrum. Ultimately, the power of the technique is limited by the resolution of the spectrometer. Here we introduce a new method for achieving Super-Spectral-Resolution Raman Spectroscopy (SSR-RS), by angle-tuning a Fabry–Perot (F-P) etalon filter that we incorporated in a micro-Raman setup. A monolithically coated F-P etalon structure, only 1.686 mm in thickness, was mounted onto an angle-tunable motorized stage, and Raman spectra were automatically acquired for many different angles of the etalon. Using a low-resolution grating of 150 g/mm by itself, without the F-P etalon, we obtained a best-case Regular-Raman spectral resolution of 44 cm−1 for the characteristic Raman peak from a diamond sample. When we applied the SSR-RS technique to diamond, we …

Early detection and treatment are crucial for Alzheimer's disease (AD) management. Current diagnostic and therapeutic methods focus on late‐stage amyloid fibrils and plaques, overlooking toxic soluble amyloid β oligomers (AβOs) accumulating early in AD. A multifunctional liposome‐based platform is designed for early diagnosis and therapy of AD, leveraging a novel self‐assembled cyclic d,l‐α‐peptide (CP‐2) that selectively targets AβOs. Biocompatible CP‐2 conjugated liposomes (CP‐2‐LPs) effectively disrupt Aβ aggregation and mitigate Aβ‐mediated toxicity in human neuroblastoma cells. In transgenic Caenorhabditis elegans AD models, CP‐2‐LPs significantly outperformed free CP‐2 by improving cognitive and behavioral functions, extending lifespan, and reducing toxic AβO levels. Intravenous injection of fluorescently labeled CP‐2‐LPs reveals effective blood‐brain barrier penetration, with significantly …

Significance: A better understanding of diffusion reflection (DR) behavior may allow it to be used for more noninvasive applications, including the development of in vivo non-damaging techniques, especially for medical topical diagnosis and treatments.Aim: For a bilayer opaque substance where the attenuation of the upper layer is larger than the attenuation of the lower layer, the DR crossover point (Cp) is location where the photons coming from the bottom layer start affecting the DR. We aim to study the dependency of the Cp on absorption changes in different layers for constant scattering and top layer thickness.Approach: Monolayer and bilayer optical tissue-like phantoms were prepared and measured using a DR system. The results were compared with Monte Carlo simulations.Results: There is an agreement between the experiments and the simulations. Cp correlates with the square root of the absorption …

Speedy and selective detection of sensing targets is of great interest to researchers from diverse fields. Dominated by excitations of intramolecular and intermolecular vibrations, the emerging terahertz (THz) spectroscopy offers both molecular fingerprint information and biosensing abilities, which is excellent for speedy and selective sensing applications. In this review, we focus on THz selective sensing principles and introduce three frequently utilized methods enabled by THz fingerprints, the interaction between THz absorption of molecules and plasmonic resonances, and THz metamaterial biosensors. The recent progress of THz selective sensing implementations including detections of gas molecules, solid molecules, protein, nucleic acid, cells, and viruses are also summarized. We note that current THz sensing research is multidisciplinary and has led cross-disciplinary collaborations between physics and …

Due to quasi-one-dimensional confinement, nanowires possess unique electronic properties, which can promote specific device architectures. However, nanowire growth presents paramount challenges, limiting the accessible crystal structures and elemental compositions. Here we demonstrate solid-state topotactic exchange that converts wurtzite InAs nanowires into Zintl Eu3In2As4. Molecular-beam-epitaxy-based in situ evaporation of Eu and As onto InAs nanowires results in the mutual exchange of Eu from the shell and In from the core. Therefore, a single-phase Eu3In2As4 shell grows, which gradually consumes the InAs core. The mutual exchange is supported by the substructure of the As matrix, which is similar across the wurtzite InAs and Zintl Eu3In2As4 and therefore is topotactic. The Eu3In2As4 nanowires undergo an antiferromagnetic transition at a Néel temperature of ~6.5 K. Ab initio calculations …

In recent years, there has been a lot of interest in biodegradable surface-engineered iron oxide nanoparticles (IONPs) because they could be used in drug delivery and other biomedical fields. This chapter gives an overview of the current state of research on how to make biodegradable IONPs, how to engineer their surfaces, and how to make them work for drug delivery and other biomedical applications. Because these nanoparticles are biodegradable, they will break down and leave the body in a safe way, reducing worries about toxicity. Also, the surface of IONPs can be changed to make them more stable, biocompatible, and able to target specific cells or tissues. This makes it easier for drugs to get to where they need to go. The review talks about how natural polymers, peptides, and targeting ligands are used to change the surface, as well as how these changes affect the physicochemical properties and …

Finding the global minimum in complex networks while avoiding local minima is challenging in many types of networks. We study the dynamics of complex human networks and observed that humans have different methods to avoid local minima than other networks. Humans can change the coupling strength between them or change their tempo. This leads to different dynamics than other networks and makes human networks more robust and better resilient against perturbations. We observed high-order vortex states, oscillation death, and amplitude death, due to the unique dynamics of the network. This research may have implications in politics, economics, pandemic control, decision-making, and predicting the dynamics of networks with artificial intelligence.

Bacteria use specialized proteins, like transcription factors, to rapidly control metal ion balance. CueR is a Gram‐negative bacterial copper regulator. The structure of E. coli CueR complexed with Cu(I) and DNA was published, since then many studies have shed light on its function. However, P. aeruginosa CueR, which shows high sequence similarity to E. coli CueR, has been less studied. Here, we applied room‐temperature electron paramagnetic resonance (EPR) measurements to explore changes in dynamics of P. aeruginosa CueR in dependency of copper concentrations and interaction with two different DNA promoter regions. We showed that P. aeruginosa CueR is less dynamic than the E. coli CueR protein and exhibits much higher sensitivity to DNA binding as compared to its E. coli CueR homolog. Moreover, a difference in dynamical behavior was observed when P. aeruginosa CueR binds to …

Silicon is a promising candidate for replacing graphite in anodes for advanced Li‐ion batteries due to its high theoretical gravimetric energy density. However, silicon as an active anode material suffers from significant volume changes upon lithiation/delithiation, causing fast capacity fading. The performance of silicon anodes depends on the polymeric binders used, which form well‐bound Si particles matrices that accommodate the strains developed during their repeated lithiation, thus maintaining their integrity.

Quantum materials have a fascinating tendency to manifest novel and unexpected electronic states upon proper manipulation. Ideally, such manipulation should induce strong and irreversible changes and lead to new relevant length scales. Plastic deformation introduces large numbers of dislocations into a material, which can organize into extended structures and give rise to qualitatively new physics as a result of the huge localized strains. However, this approach is largely unexplored in the context of quantum materials, which are traditionally grown to be as pristine and clean as possible. Here we show that plastic deformation induces robust magnetism in the quantum paraelectric SrTiO3, a property that is completely absent in the pristine material. We combine scanning magnetic measurements and near-field optical microscopy to find that the magnetic order is localized along dislocation walls and coexists with …

Intrinsically disordered proteins and regions (IDP/IDRs) are ubiquitous across all domains of life. Characterized by a lack of a stable tertiary structure, IDP/IDRs populate a diverse set of transiently formed structural states that can promiscuously adapt upon binding with specific interaction partners and/or certain alterations in environmental conditions. This malleability is foundational for their role as tunable interaction hubs in core cellular processes such as signaling, transcription, and translation. Tracing the conformational ensemble of an IDP/IDR and its perturbation in response to regulatory cues is thus paramount for illuminating its function. However, the conformational heterogeneity of IDP/IDRs poses several challenges. Here, we review experimental and computational methods devised to disentangle the conformational landscape of IDP/IDRs, highlighting recent computational advances that permit proteome …

Recent advances in DNA nanotechnology allow for the assembly of nanocomponents with nanoscale precision, leading to the emergence of DNA-based material fabrication approaches. Yet, transferring these nano- and micron-scale structural arrangements to the macroscale morphologies remains a challenge, which limits the development of materials and devices based on DNA nanotechnology. Here, we demonstrate a materials fabrication approach that combines DNA-programmable assembly with actively driven processes controlled by acoustic fields. This combination provides a prescribed nanoscale order, as dictated by equilibrium assembly through DNA-encoded interactions, and field-shaped macroscale morphology, as regulated by out-of-equilibrium materials formation through specific acoustic stimulation. Using optical and electron microscopy imaging and x-ray scattering, we further revealed the …

Nanoparticles (NPs) can be used as useful additives in construction materials. In this work, nanosilica (NS) was used in a way that prevented agglomeration of NPs as a pozzolanic material to improve Portland cement hydration and thus improve the properties of concrete. The effects of NS and polystyrene (PS) microspheres coated with NS (PS@NS) on cement paste properties were examined. Spherical PS particles were prepared by dispersion polymerisation of styrene in polar solvents and characterised by Fourier transform infrared spectroscopy and environmental scanning electron microscope. The PS@NS were synthesised using the Stöber method. Analysis showed that an amorphous NS layer was deposited uniformly on the PS particles and the core/shell structure reduced the aggregation of the NS effectively. It was also found that, compared with cement paste blended with NS, the PS@NS improved …

Two-dimensional (2D) materials have attracted vast research interest since the breakthrough discovery of graphene. One major benefit of such systems is the ability to tune the Fermi level through the charge neutrality point between electron and hole doping. Here we show that single layer graphene coupled to the low-density superconductor indium oxide (InO) exhibits two charge neutrality points, each of them representing electronic regions in which the carrier density can be tuned from hole to electron dominated. This is not seen in clean graphene or in a bilayer where the carrier density is extremely low. We suggest that the second charge neutrality point results from regions in the graphene layer just below superconducting islands in InO, where pairing is induced via the proximity effect; gating of this hybrid system therefore allows the tuning from hole to electron superconductivity through an ultralow carrier …

Carbon dots (CDs) with an average diameter of 6.3 nm were synthesized from the medicinal seed extract of Syzygium cumini L. using one-pot hydrothermal synthesis. The prepared CDs exhibited excitation-dependent emission characteristics with photoluminescence (PL) emission maxima at an excitation of 340 nm. The CDs at 500 µg/mL displayed antimicrobial activities against four common pathogens. Both Staphylococcus aureus and S. epidermidis were completely eradicated by CDs within 12 h, compared to 24 h for Escherichia coli and Klebsiella pneumonia. The release of various oxygen species (ROS) was postulated to play a critical role in bacterial eradication. The CDs decorated on cotton fabric by ultrasonication also displayed good antibacterial activities against the above bacteria. The finding opens a plausible use of CDs in biomedical textiles with potent antimicrobial properties against both Gram …

Recent advances in DNA nanotechnology allow for the assembly of nanocomponents with nanoscale precision, leading to the emergence of DNA-based material fabrication approaches. Yet, transferring these nano- and micron-scale structural arrangements to the macroscale morphologies remains a challenge, which limits the development of materials and devices based on DNA nanotechnology. Here, we demonstrate a materials fabrication approach that combines DNA-programmable assembly with actively driven processes controlled by acoustic fields. This combination provides a prescribed nanoscale order, as dictated by equilibrium assembly through DNA-encoded interactions, and field-shaped macroscale morphology, as regulated by out-of-equilibrium materials formation through specific acoustic stimulation. Using optical and electron microscopy imaging and x-ray scattering, we further revealed the …

The remarkable ability of natural proteins to conduct electricity in the dry state over long distances remains largely inexplicable despite intensive research. In some cases, a (weakly) exponential length-attenuation, as in off-resonant tunneling transport, extends to thicknesses even beyond 10 nm. This report deals with such charge transport characteristics observed in self-assembled multilayers of the protein bacteriorhodopsin (bR). About 7.5 nm to 15.5 nm thick bR layers were prepared on conductive titanium nitride (TiN) substrates using aminohexylphosphonic acid and poly-diallyl-dimethylammonium electrostatic linkers. Using conical EGaIn top contacts, an intriguing, mono-exponential conductance attenuation as a function of the bR layer thickness with a small attenuation coefficient is measured at zero bias. Variable-temperature measurements using evaporated Ti/Au top contacts yield effective energy barriers of about 100 meV from fitting the data to tunneling, hopping, and carrier cascade transport models. The observed temperature-dependence is assigned to the protein-electrode interfaces. The transport length and temperature dependence of the current densities are consistent with tunneling through the protein-protein and protein-electrode interfaces, respectively. Importantly, our results call for new theoretical approaches to find the microscopic mechanism behind the remarkably efficient, long-range electron transport within bR.

The fundamental question of “what is the transport path of electrons through proteins?” initially introduced while studying long-range electron transfer between localized redox centers in proteins in vivo is also highly relevant to the transport properties of solid-state, dry metal–protein–metal junctions. Here, we report conductance measurements of such junctions, Au-(Azurin monolayer ensemble)-Bismuth (Bi) ones, with well-defined nanopore geometry and ~103 proteins/pore. Our results can be understood as follows. (1) Transport is via two interacting conducting channels, characterized by different spatial and time scales. The slow and spatially localized channel is associated with the Cu center of Azurin and the fast delocalized one with the protein’s polypeptide matrix. Transport via the slow channel is by a sequential (noncoherent) process and in the second one by direct, off-resonant tunneling. (2) The two …

We study the interaction of a dark exciton Bose-Einstein condensate with the nuclei in gallium arsenide/aluminum gallium arsenide coupled quantum wells and find clear evidence for nuclear polarization buildup that accompanies the appearance of the condensate. We show that the nuclei are polarized throughout the mesa area, extending to regions that are far away from the photoexcitation area and persisting for seconds after the excitation is switched off. Photoluminescence measurements in the presence of radio frequency radiation reveal that the hyperfine interaction between the nuclear and electron spins is enhanced by two orders of magnitude. We suggest that this large enhancement manifests the collective nature of the N-exciton condensate, which amplifies the interaction by a factor of .

Acoustic-directed assembly is a modular and flexible bottom-up technique with the potential to pattern a wide range of materials. Standing acoustic waves have been previously employed for patterning preformed metal particles, however, direct patterning of metallic structures from precursors remains unexplored. Here, we investigate utilization of standing waves to exert control over chemical reaction products, while also exploring their potential in the formation of multi-layered and composite micro-structures. Concentric micro-structures of gold and silver were obtained by introducing a metal precursor salt and a reducing agent into a cylindrical piezoelectric resonator that also served as a reservoir. In addition, we introduce an innovative approach to directly fabricate metallic multi-layer and composite structures by reducing different metal ions or adding nanoparticles during the reduction step. We showcased our …