BINA

Contrary to everyday experience, where all liquid droplets assume rounded, near-spherical shapes, the temperature-tuning of liquid droplets to faceted polyhedral shapes and to spontaneous splitting has been recently demonstrated in oil-in-water emulsions. However, the elucidation of the mechanism driving these surprising effects, as well as their many potential applications, ranging from faceted nanoparticle synthesis through new industrial emulsification routes to controlled-release drug delivery within the human body, have been severely hampered by the micron-scale resolution of the light microscopy employed to date in all in situ studies. Thus, the thickness of the interfacially frozen crystalline monolayer, suggested to drive these effects, could not be directly measured, and the low limit on the droplet size still showing these effects remained unknown. In this study, we employ a combination of super-resolution …

Surface modified mesoporous silica materials are important materials for heterogeneous catalysis and are attracting attention as potential drug carriers. The functionality of these materials relies on the physical and chemical properties of the tethers attached to MCM41 silica surface. These chemically linked tails act as molecular brushes, that can capture pollutant molecules, anchor points for catalysts and can host drug molecules. To utilize the full potential of the tailored silica surfaces, one should infer their properties at different levels of solvation. Here, 1H MAS NMR spectroscopy is used to monitor the dynamic properties of two modified MCM41 materials, an aminopropyl tethered MCM41 and an octyl tethered MCM41, through the process of controlled hydration. The surface site resolved measurements demonstrate how the chemical nature of the two tethers governs the way water molecules are directed to the …

The remarkable development in photovoltaic (PV) technologies over the past 5 years calls for a renewed assessment of their performance and potential for future progress. Here, we analyse the progress in cells and modules based on single-crystalline GaAs, Si, GaInP and InP, multicrystalline Si as well as thin films of polycrystalline CdTe and CuIn x Ga 1− x Se 2. In addition, we analyse the PV developments of the more recently emerged lead halide perovskites together with notable improvements in sustainable chalcogenides, organic PVs and quantum dots technologies. In addition to power conversion efficiencies, we consider many of the factors that affect power output for each cell type and note improvements in control over the optoelectronic quality of PV-relevant materials and interfaces and the discovery of new material properties. By comparing PV cell parameters across technologies, we appraise how far …

Nanostructures of transition-metal dichalcogenides (TMDC) have raised scientific interest in the last few decades. Tungsten disulfide (WS 2) nanotubes and nanoparticles are among the most extensively studied members in this group, and are used for, eg, polymer reinforcement, lubrication and electronic devices. Their biocompatibility and low toxicity make them suitable for medical and biological applications. One potential application is photothermal therapy (PTT), a method for the targeted treatment of cancer, in which a light-responsive material is irradiated with a laser in the near-infrared range. In the current article we present WS 2 nanotubes functionalized with previously reported ceric ammonium nitrate–maghemite (CAN-mag) nanoparticles, used for PTT. Functionalization of the nanotubes with CAN-mag nanoparticles resulted in a magnetic nanocomposite. When tested in vitro with two types of cancer cells, the functionalized nanotubes showed a better PTT activity compared to non-functionalized nanotubes, as well as reduced aggregation and the ability to add a second-step functionality. This ability is demonstrated here with two polymers grafted onto the nanocomposite surface, and other functionalities could be additional cancer therapy agents for achieving increased therapeutic activity.

Zinc doped copper oxide nanocomposites (Zn-CuO NPs) is a novel doped metal nanomaterial synthesized by our group using the sonochemical method. Our previous studies have shown that Zn-CuO NPs could inhibit cancer cell proliferation by inducing apoptosis via ROS-mediated pathway. In the present study, we studied the anticancer effect of Zn-CuO NPs on human pancreatic cancer cells. MTS assay revealed that Zn-CuO NPs was able to inhibit cancer cell growth. TEM, flow cytometry and fluorescence microscope analysis showed that Zn-CuO NPs induced autophagy significantly; the number of autophagosomes increased obviously in cells treated with Zn-CuO NPs. Western blot analysis revealed that treatment with the NPs resulted in activation of AMPK/mTOR pathway in both AsPC-1 and MIA Paca-2 cells in dose dependent manners. Moreover, in the presence of AMPK activator AMPKinone, the protein level of p-AMPK, p-ULK1, Beclin-1 and LC3-II/LC3-I increased, while the protein expression of p-AMPK, p-ULK1, Beclin-1 and LC3-II/LC3-I decreased in the presence of AMPK inhibitor Compound C. In vivo study using xenograft mice revealed that Zn-CuO NPs significantly inhibited tumor growth with low toxicity. Our study confirms that Zn-CuO NPs inhibit the tumor growth both in vitro and in vivo for pancreatic cancer. AMPK/mTOR pathway plays an important role in the NPs induced inhibition of tumor growth.

We have studied the magnetization of a recently synthesized CuS compound and found two phase transitions around room temperature. The phase transitions in the crystalline structure, characterized by XRD studies, are accompanied by changes also in the electrical resistivity. A hysteretic first-order phase transition has been found between 260 and 320 K, from a low-temperature paramagnetic anilite phase to a diamagnetic high-temperature low-digenite phase. A second order phase transition was recognized at ≃ 352 K from low digenite to a paramagnetic high-digenite structure at high temperatures.

Photodynamic therapy (PDT) is a promising therapeutic modality for cancer treatment. It considered to be minimallyinvasive and nontoxic. Clinical PDT involves systemic administration of photosensitizer drugs, which accumulate at the tumor area and are light sensitive. When laser illuminates the tumor area in the presence of molecular oxygen, highly reactive singlet oxygen is generated, causing to direct killing of the tumor. Despite the advantages of the classical PDT, it suffers from several limitations, impeding its clinical outcome. Thus, developing targeted delivery systems for photosensitizer drugs that will enhance the selectivity is urgently needed. We develop functionalized metal nanoparticles (NPs) as carriers of mTHPC photosensitizer drug. Herein we use NPs composed of either gold or magnetically responsive carries like Ce-doped and Yb-doped -γ-Fe2O3 maghemite NPs (MNPs). All nanocomposites form …

Integrated photonics is a powerful platform that can improve the performance and stability of optical systems while providing low-cost, small-footprint, and scalable alternatives to implementations based on free-space optics. While great progress has been made on the development of low-loss integrated photonics platforms at telecom wavelengths, the visible wavelength range has received less attention. Yet, many applications utilize visible or near-visible light, including those in optical imaging, optogenetics, and quantum science and technology. Here we demonstrate an ultra-low-loss integrated visible photonics platform based on thin-film lithium niobate on an insulator. Our waveguides feature ultra-low propagation loss of 6 dB/m, while our microring resonators have an intrinsic quality factor of 11 million, both measured at 637 nm wavelength. Additionally, we demonstrate an on-chip visible intensity modulator …

Thanks to its high Kerr non-linearity and its low linear absorption, silicon is a material of choice for optical devices in the mid-infrared (from 3 to 5 microns) such as microresonators. In this wavelength range, the available optical sources such as quantum cascade lasers have a limited tunability. Tuning the refractive index of silicon can be achieved by a temperature change of the chip and has been previously demonstrated on ring resonators using integrated heaters or thermo-electric elements. We present a new method for thermo-optical tuning of silicon devices by directly using the light from a laser diode operating at 450 nm. The blue light focused on the silicon induces a local elevation of temperature and thus the refractive index locally increases. When applying this method on silicon ring resonator, the elevation of temperature leads to a decreasing free-spectral range and thus shift the resonances to lower …

Hypothesis Temperature-controlled self-faceting of liquid droplets has been recently discovered in surfactant-stabilized alkane-in-water emulsions. We hypothesize that similar self-faceting may occur in emulsion droplets of UV-polymerizable linear hydrocarbons. We further hypothesize that the faceted droplet shapes can be fixed by UV-initiated polymerization, thus providing a new route towards the production of solid polyhedra. Experiments Temperature-induced shape variations were studied by optical microscopy in micron-size emulsion droplets of UV-polymerizable alkyl acrylate. When polymerized, the resultant solid particles’ 3D shape and internal structure were determined by combined scanning electron microscopy (SEM) and focused ion beam (FIB) slicing. The SEM and FIB nanoscale resolution provided a far greater detail imaging than that achievable for the liquid droplets, which could only be studied …

Surface modification of polypropylene feed spacers typical of spiral wound membrane modules was studied by generation of crystalline ZnO nanorods. A seeding layer made by deposition of ZnO nanoparticles (20–40–60 nm diameter) from aqueous dispersions served as nucleation centers for crystallization. A uniform layer of ZnO nanorods was grown on the seeding layer by chemical bath deposition from a zinc acetate solution. Biocidal activity was estimated by antibacterial tests in static liquid culture against Escherichia coli and antibiofouling tests in flow-through/cross-flow mode against a mixture of Pseudomonas fluorescens and Bacillus subtilis. Best biocidal activity was displayed by 20 nm ZnO particles, suggesting a tradeoff between surface coverage, roughness and particle size. Although the seed layer itself displayed acceptable antibacterial activity, a marked improvement was achieved by the …

Motivation A major aim of single cell biology is to identify important cell types such as stem cells in heterogeneous tissues and tumors. This is typically done by isolating hundreds of individual cells and measuring expression levels of multiple genes simultaneously from each cell. Then, clustering algorithms are used to group together similar single-cell expression profiles into clusters, each representing a distinct cell type. However, many of these clusters result from overfitting, meaning that rather than representing biologically meaningful cell types, they describe the intrinsic ‘noise’ in gene expression levels due to limitations in experimental precision or the intrinsic randomness of biochemical cellular processes. Consequentially, these non-meaningful clusters are most sensitive to noise: a slight shift in gene expression levels due to a repeated measurement will rearrange the grouping of data points …

Light-tissue interactions are commonly studied for near infra-red (NIR) spectroscopy for imaging and diagnosis. While imaging is bound to the surface due to the high tissue scattering, many diagnosis methods, such as the photoplethysmograph (PPG) and pulse oximeter, focus on sensing instead of imaging. There are two approaches for the investigation of light-tissue interactions: one numerical and the other analytical. The most common numerical method is the Monte Carlo (MC) simulation, which is a statistical study of photon migration from the optical properties of the different tissue regions. However, the yield of such statistical approaches is limited. Analytical methods are commonly based on the diffusion theory, yet they are inaccurate near the light source. There are several solution methods, where extrapolated boundary conditions lead to a more accurate solution. Previously, we proposed measuring the …

In recent years, many quantum lights-based applications were suggested, ranging from encrypted communication and precision metrology to fluorescent biomolecules detection and advanced spectroscopy schemes. Such applications mostly rely on entanglement, the property of correlations between particles which cannot be explained by classical mechanisms, to overcome classical light limitations. Some of these applications, e.g. nonlinear spectroscopy, require the use of entangled-photon-pair interaction (EPPI) with the matter. However, such entangled pairs, generated through spontaneous parametric down-conversion (SPDC), are scarce, and multi-photon interaction with matter is usually very weak and barely detectable. Therefore, an enhancement of this interaction is needed. In our research, we investigate a novel way to achieve such enhanced EPPI using metallic nanoparticles (MNPs), which are known …

Applying stress to a ferroelastic material results in a nonlinear strain response as domains of different orientations mechanically switch. The ability to write, erase and move domain walls between such ferroelastic domains suggests a method for making nanoelectronics where the domain wall is the device. However, little is known about the magnetic properties of such domain walls. A fascinating model system is SrTiO 3, where the ferroelastic domain walls display strain-tunable polarity and enhanced conductivity. Here, we reveal a long-range magnetic order with modulations along the ferroelastic domain walls in SrTiO 3 and SrTiO 3-based heterointerfaces, which manifests itself as a striped pattern in scanning superconducting quantum interference device maps of the magnetic landscape. In conducting interfaces, the magnetism is coupled to itinerant electrons with clear signatures in magnetotransport …

An X-ray free-electron laser oscillator (XFELO) is a new type of hard X-ray source that would produce fully coherent pulses with meV bandwidth and stable intensity. The XFELO complements existing sources based on self-amplified spontaneous emission (SASE) from high-gain X-ray free-electron lasers (XFEL) that produce ultra-short pulses with broad-band chaotic spectra. This report is based on discussions of scientific opportunities enabled by an XFELO during a workshop held at SLAC on June 29 - July 1, 2016

Here, we report the preparation of carbon dots (CDs) and doping with different elements namely boron, nitrogen and phosphorous using facile single step hydrothermal method. We used biopolymers as the source material for CDs synthesis. The prepared carbon dots and elements (B, N and P) doped carbon dots’ physicochemical properties are investigated using different analytical techniques. Several analytical characteristics such as Uv-visible spectroscopy, fluorescent spectroscopy and transmission electron microscopy confirm the doping of element into carbon dots. From DLS analysis it was found that the prepared carbon dots are range from 3-9 nm. Excitation dependent fluorescence with high quantum yields for B and N doped CDs showed 47% and 44%, respectively. The doped CDs impact on cell viability was investigated against neuronal PC12 cells. Interestingly, the prepared carbon dots did not affect …

The intercalation of alkaline cations such as lithium and sodium into two-dimensional (2D) van der Waals materials effectively modifies their electronic structure. Here, we show an electrochemical intercalation process of an alkaline ion (Li+ or Na+), into vertically aligned molybdenum disulfide (MoS2) thin films by using a three-electrode flooded vessel cell, and its application as electrocatalyst for hydrogen evolution reaction. The electrochemical intercalation method is controlled by the applied current density. After electrochemical insertion, the vertically alligned MoS2 layers display an extended Wan der Waals gap. The Li and Na intercalated vertically alligned MoS2 layers demonstrate an overpotential of 0.29 V at 10 mA cm−2 towards hydrogen evolution reaction (HER) in 0.5 M H2SO4. The intercalation of Li+ or Na+ leads to the partial exfoliation of the 2D layered material. Nevertheless, the Na intercalated …

Immune checkpoint blockade (ICB) has shown unprecedented clinical success in treatment of cancer. However, not all patients show adequate response, and the treatment can lead to a broad range of adverse effects. Therefore, early identification of potential responders to therapy, using non-invasive means, is a critical challenge for improving ICB. Herein, we engineered anti-Programmed Death Ligand 1 (aPDL1) nanoparticles with enhanced ICB immunotherapy efficacy. Using a mouse model for colon cancer, we show that the nanoparticles accumulated, penetrated and efficiently prevented tumor growth. Moreover, we found a direct correlation between the amount of nanoparticle accumulation within the tumor at 48 hours, as determined by CT, and the therapeutic response. This enabled subject stratification as potential responders or non-responders, at an early time point. Thus, by integrating prognostic and …

Herpesvirus capsid assembly involves cleavage and packaging of the viral genome. The Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 43 (orf43) encodes a putative portal protein. The portal complex functions as a gate through which DNA is packaged into the preformed procapsids, and is injected into the cell nucleus upon infection. The amino acid sequence of the portal proteins is conserved among herpesviruses. Here, we generated an antiserum to ORF43 and determined late expression kinetics of ORF43 along with its nuclear localization. We generated a recombinant KSHV mutant, which fails to express ORF43 (BAC16-ORF43-null). Assembled capsids were observed upon lytic induction of this virus; however, the released virions lacked viral DNA and thus could not establish infection. Ectopic expression of ORF43 rescued the ability to produce infectious particles. ORF43 antiserum …

When a multicomponent liquid composed of particles with random interactions is slowly cooled below the freezing temperature, the fluid reorganises in order to increase (decrease) the number of strong (weak) attractive interactions and solidifies into a microphase-separated structure composed of domains of strongly and of weakly interacting particles. Using Langevin dynamics simulations of a model system we find that the limiting tensile strength of such solids can exceed that of one-component solids.