BINA

Nanoplasmonic biosensors incorporating noble metal nanocavity arrays are widely used for the detection of various biomarkers. Gold nanorods (GNRs) have unique properties that can enhance spectroscopic detection capabilities of such nanocavity-based biosensors. However, the contribution of the physical properties of multiple GNRs to resonance enhancement of gold nanocavity arrays requires further characterization and elucidation. In this work, we study how GNR aspect ratio (AR) and surface area (SA) modify the plasmonic resonance spectrum of a gold triangular nanocavity array by both simulations and experiments. The finite integration technique (FIT) simulated the extinction spectrum of the gold nanocavity array with 300 nm periodicity onto which the GNRs of different ARs and SAs are placed. Simulations showed that matching of the GNRs longitudinal peak, which is affected by AR, to the nanocavity …

Natural killer (NK)-cell-based immunotherapy is emerging as an attractive approach for cancer treatment. However, to facilitate and expedite clinical implementation, important questions must be answered regarding the in vivo functionality and trafficking patterns of the transferred cells. We have recently developed a noninvasive cell-tracking technique, based on gold nanoparticles (GNPs) as cell-labeling and contrast agents for whole-body computed tomography (CT) imaging. Herein, we report the implementation of this technique for longitudinal and quantitative tracking of NK cell kinetics, the migration and biodistribution in tumor-bearing mice. NK cells were successfully labeled with GNPs, without impairing their biological function, as assessed both in vitro, by cytokine release and cytotoxicity assays, and in vivo, using a xenograft model of human tumors. Using CT, we longitudinally tracked the migration of …

Vehicle detection plays a critical role in autonomous driving, where two central sensing modalities are lidar and radar. Although many deep neural network (DNN)-based methods have been proposed to solve this task, a systematic and methodological examination on the influence of the data on those methods is still missing. In this work, we examine the effects of resolution on the performance of vehicle detection for both lidar and radar sensors. We propose subsampling methods that can improve the performance and efficiency of DNN-based solutions and offer an alternative approach to traditional sensor-design trade-offs.

Laser‐induced forward transfer (LIFT) is an additive manufacturing technique where short laser pulses are focused through a transparent substrate onto a thin, uniform, metal layer jetting micrometer‐scale droplets yielding high‐resolution 3D metal structures. Herein, LIFT printing from multilayered metal donors, and from compositional metal mixtures, is explored and presented. A comprehensive study of this sort has been lacking so far. LIFT printing from Cu–Ag structured donors is thoroughly studied. X‐ray diffraction (XRD) analysis reveals the formation of a metastable Cu–Ag phase reflecting the high cooling rate of the metal droplets. Tuning properties of the printed metal structures is made possible by controlling the pulse width and the donor layers’ properties. Longer pulses (10 ns) jetting from cosputtered donors yield better homogeneity than shorter pulses (1 ns) from donors made of distinct sputtered …

This study presents a partially coherent illumination based (PCI-based) SIM apparatus for dual-modality (phase and fluorescent) microscopic imaging. The partially coherent illumination (PCI) is generated by placing a rotating diffuser on a monochromatic laser beam, which suppresses speckle noise in the dual-modality images and endows the apparatus with sound sectioning capability. With this system, label-free quantitative phase and super-resolved/sectioned fluorescent images can be obtained for the same sample. We have demonstrated the superiority of the system in phase imaging of transparent cells with high endogenous contrast and in a quantitative manner. In the meantime, we have also demonstrated fluorescent imaging of fluorescent beads, rat tail crosscut, wheat anther, and hibiscus pollen with super-resolution and optical sectioning. We envisage that the proposed method can be applied to many …

Electrolyzer technologies are essential for the Hydrogen Economy scheme, and in order to drive the hydrogen production price down, their lifetimes need to be extended. One important parameter that has not been given enough attention in this context is catalyst durability. In this work, a durable platinum-group metal-free catalyst was developed for the hydrogen evolution reaction based on a porous, high-surface area molybdenum carbide aerogel. The molybdenum oxide aerogel was synthesized by a sol–gel method and carburized by methane treatment. A three-dimensional molybdenum carbide network was obtained by reacting the molybdenum oxide aerogel with a CH4/H2 mixture at 700 °C. Surface area measurement confirmed a substantial increase in the volume of micropores in the transition from oxide to carbide. The carbide aerogel has low density (<0.4 g/mL) with a relatively high surface area of 109 m2 …

In their recent publication, Khatri et al.[1] describe an immunoglobulin germline gene database inferred from shortread genomic sequence data derived from five superpopulations. The development of methods for the compilation of more complete and accurate germline gene databases would be an important achievement, but we do not believe that this has been achieved. Existing databases are clearly incomplete. Germline sequences differ substantially between subjects, and alleles found in some populations may be absent in others. Existing databases are likely biased towards alleles found in European populations and may lack many sequences found in understudied populations [2]. Improved, properly designed and curated germline gene databases are therefore needed for analysis of antibody repertoires.Extensive efforts are under way to better document germline genes, and the study by Khatri et al …

Catheter-associated urinary tract infections (CAUTIs), caused by biofilms, are the most frequent health-care associated infections. Novel antibiofilm coatings are needed to increase the urinary catheters' life-span, decrease the prevalence of CAUTIs and reduce the development of antimicrobial resistance. Herein, antibacterial zinc oxide nanoparticles (ZnO NPs) were decorated with a biofilm matrix-degrading enzyme amylase (AM) and simultaneously deposited onto silicone urinary catheters in a one-step sonochemical process. The obtained nano-enabled coatings inhibited the biofilm formation of Escherichia coli and Staphylococcus aureus by 80% and 60%, respectively, for up to 7 days in vitro in a model of catheterized bladder with recirculation of artificial urine due to the complementary mode of antibacterial and antibiofilm action provided by the NPs and the enzyme. Over this period, the coatings did not …

Electro-oxidation of urea offers tremendous opportunity for the economical hydrogen production option owing to its lower thermodynamic potential barriers. Slower reaction rate and multiple gas desorption steps hinder the implementation of urea-based fuel cells, and thus understanding the urea oxidation process is key for the commercialization of this technology. In this report, we systematically examined the electrocatalytic urea oxidation activity of nickel-based model catalysts such as Ni12P5 and Ni(OH)2 in an alkaline medium at a fixed urea concentration of 0.33 M using electrochemical impedance spectroscopy (EIS). Ni12P5 and Ni(OH)2 require potentials of 0.51 and 0.54 V vs Hg/HgO, respectively, to achieve a current density of 10 mA cm–2. The origin of the catalytic activity difference of the urea oxidation reaction (UOR) between these two Ni catalysts is briefly analyzed using nondestructive in situ EIS. We …

Among many riddles posed by halide perovskites, the surprising apparent near-absence of harmful defects stands out. This is commonly explained by invoking defect tolerance (DT), but the term is used loosely, sometimes interchangeably with self-healing (SH). Also, the relation between underlying physical and chemical mechanisms and device behavior is often murky. Here, we offer our views as to what DT and SH constitute, the evidence for and against them, and what research challenges remain. In the (relatively) early days of the rebirth of halide perovskites, we wrote (with colleagues) a review, 1 originally titled “Hybrid organic− inorganic perovskites: III-V’s on the cheap”. To conform with journal policy, after final acceptance we changed it to the more pedestrian “Hybrid organic− inorganic perovskites: low-cost semiconductors with intriguing charge-transport properties”. Looking at the field today, we realize …

The monitoring of ionizing radiation is critical for the safe operation of nuclear and other high-power plants. Fiber-optic sensing of radiation has been pursued for over 45 years. Most protocols rely on radiation effects on the optical properties of the fiber. Here we propose a new concept, in which the opto-mechanics of standard fibers coated by thin layers of fluoroacrylate polymer are observed instead. The time-of-flight of radial acoustic waves through the coating is evaluated by forward stimulated Brillouin scattering measurements. The time-of-flight is seen to decrease monotonically with the overall dosage of gamma radiation from a cobalt source. Variations reach 15% of the initial value for 180 Mrad dose and remain stable for at least several weeks following exposure. The faster times-of-flight are consistent with a radiation-induced increase in the coating stiffness, observed in offline analysis. The effects on the …

Carbon dots (CDs) and their doped counterparts including nitrogen-doped CDs can be synthesized by bottom-up or top-down approaches from different precursors. The attractiveness of such emerging 2D‑carbon-based nanosized materials can be attributed to their excellent biocompatibility, preparation, aqueous dispersibility, and functionality. The antimicrobial, optical, and electrochemical properties of CDs have been advocated for two important biotechnological applications: bacterial eradication and sensing/biosensing. CDs as well as N@CDs act as antimicrobial agents as their surface encompasses functional hydroxyl, carboxyl, and amino groups that generate free radicals. As a new class of photoluminescent nanomaterials, CDs can be employed in diversified analytics. CDs with surface carboxyl or amino groups can form nanocomposites with nanomaterials or be conjugated with biorecognition molecules …

The visibility of nonlinear SU (1, 1) interference directly reflects the nonclassical properties of entangled bi-photons and squeezed light with practically unlimited bandwidth, high efficiency and ultra-high photon flux, orders of magnitude beyond the abilities of standard photo-detectors. We study experimentally the dependence of the SU (1, 1) visibility on the phase matching conditions and beam parameters in a free-space configuration, and show that maximal SU (1, 1) visibility requires extreme collinear conditions, which deviate from the conditions for maximal nonlinear conversion. We demonstrate near-ideal visibility of∼ 95%(limited only by internal loss) in an ultra-broadband SU (1, 1), interferometer with over 120 THz of squeezed light bandwidth. Utilizing this analysis we demonstrate efficient detection of the spectral phase of single-cycle bi-photons and precise compensation of the dispersion over a full octave …

Distance distribution information obtained by pulsed dipolar EPR spectroscopy provides an important contribution to many studies in structural biology. Increasingly, such information is used in integrative structural modeling, where it delivers unique restraints on the width of conformational ensembles. In order to ensure reliability of the structural models and of biological conclusions, we herein define quality standards for sample preparation and characterization, for measurements of distributed dipole–dipole couplings between paramagnetic labels, for conversion of the primary time-domain data into distance distributions, for interpreting these distributions, and for reporting results. These guidelines are substantiated by a multi-laboratory benchmark study and by analysis of data sets with known distance distribution ground truth. The study and the guidelines focus on proteins labeled with nitroxides and on double …

This study presents a partially coherent illumination based (PCI-based) SIM apparatus for dual-modality (phase and fluorescent) microscopic imaging. The partially coherent illumination (PCI) is generated by placing a rotating diffuser on a monochromatic laser beam, which suppresses speckle noise in the dual-modality images and endows the apparatus with sound sectioning capability. With this system, label-free quantitative phase and super-resolved/sectioned fluorescent images can be obtained for the same sample. We have demonstrated the superiority of the system in phase imaging of transparent cells with high endogenous contrast and in a quantitative manner. In the meantime, we have also demonstrated fluorescent imaging of fluorescent beads, rat tail crosscut, wheat anther, and hibiscus pollen with super-resolution and optical sectioning. We envisage that the proposed method can be applied to many …

The visibility of nonlinear SU(1,1) interference directly reflects the nonclassical properties of entangled bi-photons and squeezed light with practically unlimited bandwidth, high efficiency and ultra-high photon flux, orders of magnitude beyond the abilities of standard photo-detectors. We study experimentally the dependence of the SU(1,1) visibility on the phase matching conditions and beam parameters in a free-space configuration, and show that maximal SU(1,1) visibility requires extreme collinear conditions, which deviate from the conditions for maximal nonlinear conversion. We demonstrate near-ideal visibility of ~95% (limited only by internal loss) in an ultra-broadband SU(1,1), interferometer with over 120THz of squeezed light bandwidth. Utilizing this analysis we demonstrate efficient detection of the spectral phase of single-cycle bi-photons and precise compensation of the dispersion over a full octave of …

Electrolyzer technologies are essential for the Hydrogen Economy scheme, and in order to drive the hydrogen production price down, their lifetimes need to be extended. One important parameter that has not been given enough attention in this context is catalyst durability. In this work, a durable platinum-group metal-free catalyst was developed for the hydrogen evolution reaction based on a porous, high-surface area molybdenum carbide aerogel. The molybdenum oxide aerogel was synthesized by a sol–gel method and carburized by methane treatment. A three-dimensional molybdenum carbide network was obtained by reacting the molybdenum oxide aerogel with a CH4/H2 mixture at 700 °C. Surface area measurement confirmed a substantial increase in the volume of micropores in the transition from oxide to carbide. The carbide aerogel has low density (<0.4 g/mL) with a relatively high surface area of 109 m2 …

Electro-oxidation of urea offers tremendous opportunity for the economical hydrogen production option owing to its lower thermodynamic potential barriers. Slower reaction rate and multiple gas desorption steps hinder the implementation of urea-based fuel cells, and thus understanding the urea oxidation process is key for the commercialization of this technology. In this report, we systematically examined the electrocatalytic urea oxidation activity of nickel-based model catalysts such as Ni12P5 and Ni(OH)2 in an alkaline medium at a fixed urea concentration of 0.33 M using electrochemical impedance spectroscopy (EIS). Ni12P5 and Ni(OH)2 require potentials of 0.51 and 0.54 V vs Hg/HgO, respectively, to achieve a current density of 10 mA cm–2. The origin of the catalytic activity difference of the urea oxidation reaction (UOR) between these two Ni catalysts is briefly analyzed using nondestructive in situ EIS. We …

Polypyrrole (PPY) spherical particles synthesized using carbon dots as an efficient catalyst were strongly embedded on fluorinated nonwoven fabric by ultrasonication to form a membrane with high hydrophilicity. An optimal amount of PPY adhered to the membrane after 30 min of sonication enhanced the overall membrane area with high hydrophilicity. Oil with high hydrophobicity was repelled by the resulting membrane, whereas water was freely penetrated and diffused from the membrane. The membrane exhibited good reusability and efficiency for the recovery of oil from a cooking oil–water mixture within 30 s. The incorporation of PPY in the fluorinated fabric imparts significant antibacterial properties against two common pathogens, Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The anti-biofouling membrane could pave the way for its potential application to separate spilled oil …