In this review we present new concepts and recent progress in the application of semiconductor quantum dots (QD) as labels in two important areas of biology, bioimaging and biosensing. We analyze the ...biologically relevant properties of QDs focusing on the following topics: QD surface treatment and stability, labeling of cellular structures and receptors with QDs, incorporation of QDs in living cells, cytotoxicity of QDs and influence of the biological environment on the biological and optical properties of QDs. Initially, we consider utilization of QDs as agents in high-resolution bioimaging techniques that can provide information at the molecular levels. The diverse range of modern live-cell QD-based imaging techniques with resolution far beyond the diffraction limit of light is examined. In each technique, we discuss the pros and cons of QD use and deliberate how QDs can be further engineered to facilitate their application in the respective imaging techniques and to produce significant improvements in resolution. Then we review QD-based point-of-care bioassays, bioprobes, and biosensors designed in different formats ranging from analytic biochemistry assays and ELISA, to novel point-of-care smartphone integrated QD-based biotests. Here, a wide range of QD-based fluorescence bioassays with optical transduction, elecrochemiluminescence and photoelectrochemical assays are discussed. Finally, this review provides an analysis of the prospects of application of QDs in selected important areas of biology.
In this review we present new concepts and recent progress in the application of semiconductor quantum dots (QD) as labels in two important areas of biology, bioimaging and biosensing.
Colloidal quantum dots for optoelectronics Litvin, A. P; Martynenko, I. V; Purcell-Milton, F ...
Journal of materials chemistry. A, Materials for energy and sustainability,
2017, Letnik:
5, Številka:
26
Journal Article
Recenzirano
This review is focused on new concepts and recent progress in the development of three major quantum dot (QD) based optoelectronic devices: photovoltaic cells, photodetectors and LEDs. In each ...application, we discuss recent champion devices with a range of architectures and discuss in detail the chronological steps taken to produce significant improvements in efficiency. We consider this relative to developments in colloidal quantum dots and their effects on these devices, covering alloyed, doped and core/shell QDs, quaternary Cu-Zn-In-S QDs, graphene and silicon QDs, and the wide range of highly promising NIR QDs. The diverse range of novel device designs is examined, including all-quantum dot devices, ternary hybrid compounds, plasmonic enhancements, and nano-heterojunction architectures. In addition, we analyse recent advances in charge transport layers, blocking layers, nanostructured photoanode fabrication and the importance of QD surface treatments. Throughout, we emphasise the use of hybrid composite materials including combinations of QDs with metal oxides, plasmonic nanoparticles, graphene and others. Finally, this review provides an analysis of prospects of these important selected quantum dot-based optoelectronic devices.
This review is focused on new concepts and recent progress in the development of three major quantum dot (QD) based optoelectronic devices: photovoltaic cells, photodetectors and LEDs.
Stable isotope analysis (SIA) of highly migratory marine pelagic animals can improve understanding of their migratory patterns and trophic ecology. However, accurate interpretation of isotopic ...analyses relies on knowledge of isotope turnover rates and tissue-diet isotope discrimination factors. Laboratory-derived turnover rates and discrimination factors have been difficult to obtain due to the challenges of maintaining these species in captivity. We conducted a study to determine tissue- (white muscle and liver) and isotope- (nitrogen and carbon) specific turnover rates and trophic discrimination factors (TDFs) using archived tissues from captive Pacific bluefin tuna (PBFT), Thunnus orientalis, 1-2914 days after a diet shift in captivity. Half-life values for (15)N turnover in white muscle and liver were 167 and 86 days, and for (13)C were 255 and 162 days, respectively. TDFs for white muscle and liver were 1.9 and 1.1‰ for δ(15)N and 1.8 and 1.2‰ for δ(13)C, respectively. Our results demonstrate that turnover of (15)N and (13)C in bluefin tuna tissues is well described by a single compartment first-order kinetics model. We report variability in turnover rates between tissue types and their isotope dynamics, and hypothesize that metabolic processes play a large role in turnover of nitrogen and carbon in PBFT white muscle and liver tissues. (15)N in white muscle tissue showed the most predictable change with diet over time, suggesting that white muscle δ(15)N data may provide the most reliable inferences for diet and migration studies using stable isotopes in wild fish. These results allow more accurate interpretation of field data and dramatically improve our ability to use stable isotope data from wild tunas to better understand their migration patterns and trophic ecology.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A physicochemical analysis of the genesis of a unique Matryoshka-type diamond from the Nyurbinskaya kimberlite pipe of the Nakyn kimberlite field, Yakutia, Russia, was performed. The specimen ...consists of a host diamond with a cavity containing a loose diamond inclusion; two through holes with a width of 0.1–0.4 mm emerge from the cavity. The analysis is based on the mantle-carbonatite theory of the genesis of diamonds and associated phases developed on the basis of consistent results of a physicochemical experiment and an analytical study of paragenetic inclusions in natural diamonds from kimberlite deposits. The published data of crystal morphological and physical studies of the Matryoshka diamond were used as well. As a result, the physicogeochemical mechanisms of nucleation and crystallization of the host diamond with a cavity and diamond inclusion under the conditions of mass genesis of diamonds in completely miscible carbonate–eclogite–carbon melts of the upper-mantle diamond-forming chamber are substantiated. The initially closed cavity was filled with a diamond-forming carbonate–silicate melt with dissolved carbon. In addition, an analysis of the conditions of etching and dissolution of the host diamond and diamond inclusion during the kimberlite transport of diamond-bearing material from the mantle chamber to the depths of the Earth’s crust was performed. The reasons for the explosive formation of cone-shaped through holes in the main diamond, which was accompanied by the ejection of the diamond-forming medium and the filling of the cavity with (С–О–Н)-fluid-containing kimberlite melt, are considered. The final episodes of partial dissolution of diamonds from the Matryoshka sample by kimberlite and assimilated melts continued during the formation of a cumulative chamber in the Earth’s crust and its solidification with the release of a highly compressed C–O–H fluid. “Fluid drilling” of the top of the cumulative chamber stimulated the explosive formation of the Nyurbinskaya pipe and its filling with kimberlite and assimilated diamondiferous matter. With prolonged compaction of this substance, the Matryoshka diamond was subjected to atmospheric and hydrothermal factors, as is evidenced by fine-grained sedimentary barite, a mineral of barium sulphate, found in the through holes of the host diamond.
Preserving biodiversity is a global challenge requiring data on species’ distribution and abundance over large geographic and temporal scales. However, traditional methods to survey mobile species’ ...distribution and abundance in marine environments are often inefficient, environmentally destructive, or resource‐intensive. Metabarcoding of environmental DNA (eDNA) offers a new means to assess biodiversity and on much larger scales, but adoption of this approach for surveying whole animal communities in large, dynamic aquatic systems has been slowed by significant unknowns surrounding error rates of detection and relevant spatial resolution of eDNA surveys. Here, we report the results of a 2.5 km eDNA transect surveying the vertebrate fauna present along a gradation of diverse marine habitats associated with a kelp forest ecosystem. Using PCR primers that target the mitochondrial 12S rRNA gene of marine fishes and mammals, we generated eDNA sequence data and compared it to simultaneous visual dive surveys. We find spatial concordance between individual species’ eDNA and visual survey trends, and that eDNA is able to distinguish vertebrate community assemblages from habitats separated by as little as ~60 m. eDNA reliably detected vertebrates with low false‐negative error rates (1/12 taxa) when compared to the surveys, and revealed cryptic species known to occupy the habitats but overlooked by visual methods. This study also presents an explicit accounting of false negatives and positives in metabarcoding data, which illustrate the influence of gene marker selection, replication, contamination, biases impacting eDNA count data and ecology of target species on eDNA detection rates in an open ecosystem.
•There is a need for a brief screener to assess the ICD-11 trauma disorders.•The complex trauma screener (CTS) is a newly developed seven-item instrument that efficiently assesses the ICD-11 trauma ...disorders.•The CTS has good psychometric properties and can be used in several populations.•The CTS is freely and publicly available at https://psychology.unt.edu/cts.
The purpose of this study was to develop the Complex Trauma Screener (CTS), a brief screener (seven items) of the ICD-11 trauma disorders that can be used in “quick-paced” facilities. We examined the factor structure of the CTS in two separate samples: civilian college students (N = 823) and military veterans (N = 130) who reported exposure to at least one traumatic event. Confirmatory factor analyses (CFAs) supported two highly-correlated factors (post-traumatic stress disorder PTSD and Disturbances in Self-Organization DSO) that loaded on the ICD-11-consistent items. The model fit indices indicated good to excellent model fit in both samples, and the internal consistencies for the scales were borderline to good (α = 0.68–0.86). Supplementary analyses supported the gender invariance of the CFA model in the civilian student sample, as well as convergent (with another trauma inventory) and discriminant validity (with borderline disorder features, depression, and mania) of the CTS in both samples. The CTS is, to our knowledge, the shortest instrument designed to measure the ICD-11 trauma disorders and is ideal for “fast-paced” facilities that have significant assessment time restraints. The CTS is, therefore, is a psychometrically-validated instrument that can help mental health professionals efficiently screen adults for ICD-11 trauma disorders.
Magneto-optical phenomena such as the Faraday and Kerr effects play a central role in controlling the polarization and intensity of optical fields propagating through a medium. Intensity effects in ...which the direction of light emission depends on the orientation of the external magnetic field are of particular interest, as they can be harnessed for routing light. Effects known so far for accomplishing such routing all control light emission along the axis parallel to the magnetic field. Here we report a new class of emission phenomena where directionality is established perpendicular to the externally applied magnetic field for light sources located in the vicinity of a surface. As a proof of principle for this effect, which we call transverse magnetic routing of light emission, we demonstrate the routing of emission for excitons in a diluted-magnetic-semiconductor quantum well. In hybrid plasmonic semiconductor structures, we observe significantly enhanced directionality of up to 60%.
Stable isotope analysis (SIA) is becoming a commonly used tool to study the ecology of elasmobranchs. However, the retention of urea by elasmobranchs for osmoregulatory purposes may bias the analysis ...and interpretation of SIA data. We examined the effects of removing urea and lipid on the stable isotope composition of 14 species of sharks, skates, and rays from the eastern North Pacific Ocean. While effects were variable across taxa, removal of urea generally increased δ
15
N and C:N. Urea removal had less influence on δ
13
C, whereas extracting urea and lipid generally increased δ
15
N, C:N, and δ
13
C. Because C:N values of nonextracted tissues are often used to infer lipid content and adjust δ
13
C, shifts in C:N following urea extraction will change the inferred lipid content and bias any mathematical adjustment of δ
13
C. These results highlight the importance of urea and lipid extraction and demonstrate the confounding effects of these compounds, making it impossible to use C:N of non-urea-extracted samples as a diagnostic tool to estimate and correct for lipid content in elasmobranch tissues.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We investigate the effect of manipulating the laser quality factor and the spectral properties of the gain medium on an oligomer-based plasmonic nanolaser. We develop different designs of the ...oligomer resonators, decreasing the lasing threshold and increasing the mode lifetime to improve the lasing efficiency. Based on the designs we are able to decrease the lasing threshold by a factor of ten. We discuss and show numerically the influence of the oligomer geometry, the lasing mode oscillation lifetime, and the photoluminescence peak linewidth of the gain medium on the lasing efficiency of the oligomer based plasmonic nanolaser.
We study theoretically the orbital angular momentum (OAM) density in arbitrary scalar optical fields, and outline a simple approach using only a spatial light modulator to measure this density. We ...demonstrate the theory in the laboratory by creating superpositions of non-diffracting Bessel beams with digital holograms, and find that the OAM distribution in the superposition field matches the predicted values. Knowledge of the OAM distribution has relevance in optical trapping and tweezing, and quantum information processing.
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