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Photothermal conversion of energy in plasmonic nanostructures brought a new fascinating field of plasmon‐induced optofluidics to life. Notably, the heat generation by plasmonic nanostructures and consequent fluid convection recently attracted wide attention; however, the possibility of controlling and manipulating liquid surfaces has been sparsely investigated. The plasmon heating and convective fluid flow lead to the emergence of the surface tension gradient on a free liquid surface interface with air, resulting in the Marangoni effect‐driven fluid flow observed as water deformation. Here, nanoscale asymmetric fluid deformation anchored on the chiral plasmon‐induced optofluidic effect is reported on. To understand the fluid dynamics of surface deformation, a theoretical model is developed. The results demonstrate that deformation at different depths can be obtained by adjusting structural parameters or incident light intensity. The fundamental understanding of light‐induced asymmetric deformation will contribute to expanding chirality‐related discipline and open new avenues for controlling fluid flow at the micro‐ or nano‐scale. The proposed method can encourage the research and applications of optofluidics, including integrated fluidic devices, biochemistry, and clinical biology. Moreover, the use of the asymmetric fluid deformation on thermal dewetting of thin films of polymer solutions can be employed for the fabrication of functional and nanopatterned metal/polymer metasurfaces. [ABSTRACT FROM AUTHOR]

Can chiral light induce chiral shapes in nanocrystals in a diluted solution? So far, it has been unclear whether it could be and, if such, under which conditions it may occur. By using realistic models of plasmonic nanocrystals, this work shows that the imprinting of 3D chirality on nanocrystals in solution by circularly polarized light (CPL) is possible. Such 3D‐chiral patterns originate from the electromagnetic retardation effect. This work investigates the formation of chiral spatial distributions of the near fields and hot electrons produced by CPL in both substrate and solution settings. Anisotropic nanocrystals with sharp edges and tips are preferable for inducing 2D and 3D chirality because of the formation of chiral hot‐spot patterns on them. The 2D g‐factors are always much higher than the 3D ones. In addition, 3D‐chiral imprinting on spherical nanocrystals is impossible. With linearly polarized light (LPL), one can create chiral nanocrystals on a substrate, not in a solution. This study provides the principles for emerging technologies to create chiral nanostructures using CPL and LPL illuminations. [ABSTRACT FROM AUTHOR]

Reducing the lasing threshold in optically pumped organic lasers is a necessary component of the drive to develop an organic laser diode, as this may help mitigate the losses associated with electrical contacts and charge injection. In this study we show how increasing the binaphthyl (BN) spacer content in polydioctylfluorene (PFO) decreases its amplified spontaneous emission threshold (ASE) through the suppression of intermolecular interactions. Using co-polymers with low lasing thresholds, we use a laser patterning technique to fabricate physical defects (having a diameter of ∼2.5 μm) within a vertical microcavity. Such defects create additional lateral confinement, with this approach allowing us to reduce the lasing threshold from 11 μJ cm−2 to 7 μJ cm−2 and increase cavity Q-factor from 495 (planar cavity) to 2300. The enhanced performance and the stack structure of the defect microcavity show it is a promising architecture for an electrically-pumped laser device. [ABSTRACT FROM AUTHOR]

Vertically aligned monolayers of metallic nanorods have a wide range of applications as metamaterials or in surface enhanced Raman spectroscopy. However the fabrication of such structures using current top-down methods or through assembly on solid substrates is either difficult to scale up or have limited possibilities for further modification after assembly. The aim of this paper is to use the adsorption kinetics of cylindrical nanorods at a liquid interface as a novel route for assembling vertically aligned nanorod arrays that overcomes these problems. Specifically, we model the adsorption kinetics of the particle using Langevin dynamics coupled to a finite element model, accurately capturing the deformation of the liquid meniscus and particle friction coefficients during adsorption. We find that the final orientation of the cylindrical nanorod is determined by their initial attack angle when they contact the liquid interface, and that the range of attack angles leading to the end-on state is maximised when nanorods approach the liquid interface from the bulk phase that is more energetically favorable. In the absence of an external field, only a fraction of adsorbing nanorods end up in the end-on state (≲40% even for nanorods approaching from the energetically favourable phase). However, by pre-aligning the metallic nanorods with experimentally achievable electric fields, this fraction can be effectively increased to 100%. Using nanophotonic calculations, we also demonstrate that the resultant vertically aligned structures can be used as epsilon-near-zero and hyperbolic metamaterials. Our kinetic assembly method is applicable to nanorods with a range of diameters, aspect ratios and materials and therefore represents a versatile, low-cost and powerful platform for fabricating vertically aligned nanorods for metamaterial applications. [ABSTRACT FROM AUTHOR]

Photoluminescent properties of CdSe/ZnS nanocrystals (quantum dots, QDs) in complexes with elongated gold nanoparticles was found to be dependent on the effective refractive index of the medium. It has been experimentally shown that changes in the refractive index make possible to increase the photoluminescence intensity by several times. [ABSTRACT FROM AUTHOR]

Abstract Background Selective estrogen receptor modulators (SERMs) have been developed in order to create means to control estrogenic effects on different tissues. A major drawback in treatment of estrogen receptor (ER) positive breast cancer with the antagonist tamoxifen (TAM) is its agonistic effect in the endometrium. Raloxifene (RAL) is the next generation of SERMs where the agonistic effect on the endometrium has been reduced. Methods The aim of the present study was to determine the effect of SERM treatment on the uterus, as assessed by proliferation markers and several factors involved in uterine growth. Ovariectomized (ovx) rats were treated with estradiol (E2), tamoxifen (TAM), RAL, ICI182780 (ICI) or vehicle (OVX-controls). We studied the effects on mRNA levels of the growth hormone (GH) receptor, insulin-like growth factor-I (IGF-I), ERα and ERβ. In addition, by immunohistochemistry the proliferation markers PCNA and Ki-67, as well as ERα and ERβ, were detected. Results The uterine weight of the rats treated with E2 or TAM was increased as compared to OVX-controls. The uterine GH-receptor mRNA level was highest in the E2 treated animals. In ICI treated rats no GH-receptor mRNA could be detected. The IGF-I mRNA level increased 16-fold in uteri of the TAM treated group and 9-fold in the E2 treated rats as compared to OVX-controls. The ERα mRNA level was increased in the E2 treated rats, while the ERβ mRNA level was increased after TAM treatment. The proliferation, as assessed by PCNA, was lowest in ICI treated animals. Conclusions The uterine wet weight, the LE height and the GH-receptor mRNA levels showed similar patterns, indicating that GH is involved in the regulation of uterine weight. Tamoxifen, which has been related to increased incidence of endometrial carcinoma in women, dramatically increased IGF-I mRNA levels in rat uterus. Since proliferation was not higher in TAM and E2 treated rats than in OVX controls, this assay of simple, early proliferation does not give the full explanation of why TAM should enhance the risk of developing endometrial cancer.

The effect of gold and silver plasmonic films on the photoluminescence and photostability of InP/ZnSe/ZnSeS/ZnS nanocrystals (quantum dots) is reported. Colloidal gold films promote the photostability enhancement of InP/ZnSe/ZnSeS/ZnS quantum dots (more durable emission properties in the presence of metal nanostructures) through reducing exciton lifetime. In contrast, silver decreases the photostability of InP/ZnSe/ZnSeS/ZnS quantum dots without changing the photoluminescence intensity and kinetics. By adjusting the excitation wavelength closer to the extinction band of gold nanoparticles a 1.8-fold enhancement of luminescence intensity has been obtained using a polyelectrolyte spacer between the metal and InP/ZnSe/ZnSeS/ZnS nanoparticles. Thus, plasmonics offers essential practical improvement of light emitters in terms of their durable luminescent properties upon prolonged optical excitation without losses in luminescence efficiency or even along with increased efficiency. [ABSTRACT FROM AUTHOR]

Abstract: The effect of molecular-beam epitaxy (MBE) growth conditions on properties of AlN epitaxial layers was investigated resulting in determination of optimal substrate temperature and ammonia flow. Optimal substrate temperature for growth of GaN and AlGaN layers was determined analyzing thermal decomposition rate of GaN. Based on the information, high electron mobility transistor heterostructures were grown on sapphire substrates using both ammonia and combined plasma-assisted/ammonia MBE modes. The highest achieved 2DEG mobility was 1992 cm2/(V s) (at 2DEG density of 1.17 × 1013 cm-2) which is the current state-of-the-art level. [ABSTRACT FROM AUTHOR]

A simple procedure for the fabrication of colloidal silver films on the surface of flexible polymer substrates, such as polypropylene and polyethylene, with the use of only polyelectrolyte pre‐treatment is presented. The optical properties of these films depend on the number of predeposited polyelectrolyte layers and salt concentration. The uncharged nature of the polymer surface allows to alternate the first polyelectrolyte layer (positively or negatively charged). The proposed method of silver deposition can be used for manufacturing silver films of different density on the polymer surfaces. This approach is low‐cost, does not require special equipment and allows to control the surface properties of the films. Using an average salt concentration (0.5 M) during the deposition of polyelectrolytes allowed to produce the densest films. [ABSTRACT FROM AUTHOR]

The photoluminescence of gold nanorod-quantum dots complexes was investigated in order to find optimal conditions for the luminescence enhancing. The number of quantum dots and polyelectrolyte layers on the gold nanorod surface in these complexes were considered as main factors in the enhancement. [ABSTRACT FROM AUTHOR]

Polarized photoluminescence (PL) of a series of m -plane InGaN/GaN multiple quantum well heterostructures ( xIn = 5-30%) was measured in a wide temperature range (T = 10-580 K). A pronounced S-shape behaviour of PL band position was observed for all samples which is an evidence of a high degree of localization of photogenerated carriers. From temperature dependences of the PL degree of polarization, the energy difference between the two highest valence subbands Δ E in InGaN was estimated to be increasing from ∼70 meV to ∼160 meV with rising indium content from 5% to 30%. The high-temperature spectral difference between the polarized PL components was substantially lower than Δ E which is caused by imperfect polarization of optical transitions to different valence subbands. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Se efectuaron análisis químicos y petrográficos de tres muestras de los productos de la erupción del volcán "El Chichón" (marzo-abril 1982). Los análisis químicos muestran que se trata de magma de composición andesítica con un alto contenido de gases. El análisis petrográfico reveló la presencia de anhidrita en dos de las muestras, lo cual es interpretado como resultado de la contaminación con aguas sulfurosas y evaporitas observadas en la zona. Los resultados obtenidos pueden indicar la existencia de una cámara magmática muy superficial. Con base en los análisis de componentes solubles en agua, se calculó la masa total de estos en aproximadamente 31.8 x 106 Ton, para una masa total de los productos de 0.5 km3. doi: https://doi.org/10.22201/igeof.00167169p.1982.21.1.1073

Background: Selective estrogen receptor modulators (SERMs) have been developed in order to create means to control estrogenic effects on different tissues. A major drawback in treatment of estrogen receptor (ER) positive breast cancer with the antagonist tamoxifen (TAM) is its agonistic effect in the endometrium. Raloxifene (RAL) is the next generation of SERMs where the agonistic effect on the endometrium has been reduced. Methods: The aim of the present study was to determine the effect of SERM treatment on the uterus, as assessed by proliferation markers and several factors involved in uterine growth. Ovariectomized (ovx) rats were treated with estradiol (E2), tamoxifen (TAM), RAL, ICI182780 (ICI) or vehicle (OVX-controls). We studied the effects on mRNA levels of the growth hormone (GH) receptor, insulin-like growth factor-I (IGF-I), ERα and ERβ. In addition, by immunohistochemistry the proliferation markers PCNA and Ki-67, as well as ERα and ERβ, were detected. Results: The uterine weight of the rats treated with E2 or TAM was increased as compared to OVX-controls. The uterine GH-receptor mRNA level was highest in the E2 treated animals. In ICI treated rats no GH-receptor mRNA could be detected. The IGF-I mRNA level increased 16-fold in uteri of the TAM treated group and 9-fold in the E2 treated rats as compared to OVX-controls. The ERα mRNA level was increased in the E2 treated rats, while the ERβ mRNA level was increased after TAM treatment. The proliferation, as assessed by PCNA, was lowest in ICI treated animals. Conclusions: The uterine wet weight, the LE height and the GH-receptor mRNA levels showed similar patterns, indicating that GH is involved in the regulation of uterine weight. Tamoxifen, which has been related to increased incidence of endometrial carcinoma in women, dramatically increased IGF-I mRNA levels in rat uterus. Since proliferation was not higher in TAM and E2 treated rats than in OVX controls, this assay of simple, early proliferation does not give the full explanation of why TAM should enhance the risk of developing endometrial cancer. [ABSTRACT FROM AUTHOR]

Plasmon–exciton coupling is of great importance to many optical devices and applications. One of the coupling manifestations is plasmon-enhanced fluorescence. Although this effect is demonstrated in numerous experimental and theoretical works, there are different particle shapes for which this effect is not fully investigated. In this work electrostatic complexes of gold nanorods and CdSe/CdZnS quantum dots were studied. Double-resonant gold nanorods have an advantage of the simultaneous enhancement of the absorption and emission when the plasmon bands match the excitation and fluorescence wavelengths of an emitter. A relationship between the concentration of quantum dots in the complexes and the enhancement factor was established. It was demonstrated that the enhancement factor is inversely proportional to the concentration of quantum dots. The maximal fluorescence enhancement by 10.8 times was observed in the complex with the smallest relative concentration of 2.5 quantum dots per rod and approximately 5 nm distance between them. Moreover, the influence of quantum dot location on the gold nanorod surface plays an important role. Theoretical study and experimental data indicate that only the position near the nanorod ends provides the enhancement. At the same time, the localization of quantum dots on the sides of the nanorods leads to the fluorescence quenching. [ABSTRACT FROM AUTHOR]

Abstract: Laser ablation in liquid media is considered as a new sample preparation technique in the elemental composition analysis of materials using optical emission spectroscopy of inductively coupled plasma (ICP-OES). Solid samples are transformed into uniform colloidal solutions of nanosized analyte particles using laser radiation focused onto the sample surface. High homogeneity of the resulting solution allows performing the ICP-OES quantitative analysis especially for the samples, which are poorly soluble in acids. The technique is compatible with the conventional solution-based standards. [Copyright &y& Elsevier]

Quantum dots (QDs) are semiconducting inorganic nanocrystals, that have garnered interest in biological and medical spheres due, to their potential benefits in biomedical imaging and drug-delivery systems. Indium phosphide QDs shelled with zinc sulphide (InP/ZnS) are viewed as more biocompatible than previous heavy metal based QDs. However, little is known about how InP/ZnS QDs affect a key blood cell, the platelet. Understanding how platelets interact with QDs is critical as unwanted activation can lead to pathological thrombus formation. Herein, we demonstrate PEGylation of InP/ZnS QDs coated with lipoic acid (QD-LA) or coated with penicillamine (QD-Pen) surface ligands induced markedly less platelet aggregation, platelet–QD interactions, integrin activation, alpha granule secretion and restored platelet spreading in washed platelets in comparison to their non-PEGylated counterparts. Furthermore, in whole blood, PEGylation of QDs reduced the number of QDs in the thrombus, thereby helping to minimise the chance of dysfunctional thrombus formation. Overall, we show that QD PEGylation is important to help prevent QD mediated platelet activation. In combination with the most biocompatible coating, PEGylation markedly reduced platelet activation, widening the concentrations at which QDs were viable for development as potential drug delivery or imaging agents. [ABSTRACT FROM AUTHOR]

The chirality and chiroptical response of materials have attracted significant attention for their potential to introduce the new science of light-matter interactions. We demonstrate that collective mode formation under modal coupling between localized surface plasmon resonances (LSPRs) with a chiral arrangement and Fabry–Pérot (FP) nanocavity modes can induce chiroptical responses. We fabricated a cluster of isotropic gold nanodisks with a chiral arrangement (gold nano-windmills, Au-NWs) on the FP nanocavities of TiO2 and Au film. The differential absorption of the Au-NWs coupled with the FP nanocavities under left- and right-handed circularly polarized light irradiations in the far field was significantly enhanced compared with the differential absorption without the FP nanocavities. Far- and near-field analyses by numerical simulation revealed that the Au-NWs coupled with the FP nanocavities formed a collective mode in the near field, and the collective mode represented the chiroptical response in the far field. The light field with the large helicity, can be used in chiral light-matter interactions. The concept of collective mode formation using isotropic metal nanodisks coupled with FP nanocavities provides a platform for controlling complex light fields. [ABSTRACT FROM AUTHOR]

The layered Vuruchuaivench Intrusion (VI) is located in the eastern part of the Fennoscandian Shield and is part of the Early Paleoproterozoic Monchegorsk Intrusive Complex (MIC). The platinum metal mineralization of this intrusion is localized within a stratiform reef-type platinum-bearing horizon that is about 2 km long and 1–3 m thick; in some boreholes, up to 15–20 m. The dissemination of Fe–Cu–Ni sulfides containing platinum-group minerals (PGMs), silver, and gold is confined to areas of gabbronorites and anorthosites with a massive and very-textured structure, with a wide development of fluid-bearing minerals in the intercumulus of cumulative phases. The uniform distribution of rock-forming, trace, and rare-earth elements in the rocks of the platinum-metal reef (platinum-group element reef) and its host rocks suggests the formation of gabbronorites during intrachamber differentiation without supplying additional portions of the melt. The composition and ratios between platinum group minerals and sulfides and silicates indicate a close genetic relationship between PGMs and magmatic sulfides. As the temperature decreases, primary PGMs and sulfides are altered under the influence of high-T magmatic fluids and hydrothermal solutions, with the formation of a wide range of PGMs. Ores are dominated by palladium arsenides, stibioarsenides, and bismuth tellurides. The separation of an immiscible arsenide melt, with the formation of numerous drop-shaped and globular intergrowths dominated by Pd–Ni-arsenides and Pd-stibioarsenides, plays a significant role in the formation of platinum-metal mineralization within the Vuruchuaivench intrusion. In some sulfide impregnations, platinum diarsenide (sperrylite) occurs instead of globules composed of palladium and nickel arsenides. The formation of specific platinum-metal associations appears to be due to the addition of As, Sb, and other incompatible elements to the magma through extensive assimilation of Archean crustal rocks. [ABSTRACT FROM AUTHOR]