Ultrafast Green Single Photon Emission from an InGaN Quantum Dot-in-a-GaN Nanowire at Room Temperature

In recent years, there has been a growing demand for room-temperature visible single-photon emission from InGaN nanowire-quantum-dots (NWQDs) due to its potential in developing quantum computing, sensing, and communication technologies. Despite various approaches explored for growing InGaN quantum dots on top of nanowires (NWs), achieving the emission of a single photon at room temperature with sensible efficiency remains a challenge. This challenge is primarily attributed to difficulties in accomplishing the radial confinement limit and the inherent giant built-in potential of the NWQD. In this report, we have employed a novel Plasma Assisted Molecular Beam Epitaxy (PAMBE) growth approach to reduce the diameter of the QD to the excitonic Bohr radius of InGaN, thereby achieving strong lateral confinement. Additionally, we have successfully suppressed the strong built-in potential by reducing the QD diameter. Toward the end of the report, we have demonstrated single-photon emission (${\lambda}$ = 561 nm) at room-temperature from the NWQD and measured the second-order correlation function $g^{2}(0)$ as 0.11, which is notably low compared to other reported findings. Furthermore, the lifetime of carriers in the QD is determined to be 775 ps, inferring a high operational speed of the devices

Perspectives on dual-purpose functional nanomaterials for detecting and removing fluoride ion from environmental water

Fluoride (F–) is a unique analyte because when in small quantities, it is beneficial and harmful when in larger or negligible quantities, leaving it essential for dual-purpose detection and removal from a water sample to prevent fluoride-caused health risks. F– detection and removal using organic molecules and hybrid materials are extensively reported in the literature, but very few reports discuss dual-purpose detection and removal. Functional nanomaterials (FNM) based on nanoparticles, metal-organic frameworks, and carbon dots conjugated with fluorophore moiety are largely used for these purposes. Functional groups on nanomaterial surfaces exhibited various interactions such as agglomeration, electrostatic, hydrogen bonding, ion exchange, coordination and π-π stacking interactions, enabling dual-purpose detection and removal of F–. These materials offer unique properties such as tunable pore structure, size, and morphology coupled with large surface area and high thermal/chemical stability. Further, this perspective review discusses prospects for sustainable technologies and describes the advantages and disadvantages of using FNM based on its optical properties for detection and removal efficiency. We believe this is the first account that summarizes the single FNM that can be used for simultaneously the selective detection of F– in aqueous media and its efficient removal

Rad26, the Transcription-Coupled Repair Factor in Yeast, Is Required for Removal of Stalled RNA Polymerase-II following UV Irradiation

Transcription coupled nucleotide excision repair (TCR) is a major pathway responsible for removal of helix distorting DNA lesions from transcriptionally active regions of the genome. Rad26, a key factor of the TCR pathway, is known to play a role during early steps of TCR. Here, we show that Rad26-mediated TCR is not absolutely dependent on active transcription elongation in budding yeast. As per our results, RAD26- deleted cells show enhanced UV sensitivity compared to wild type cells under conditions where transcription elongation is inhibited. The increased UV sensitivity observed in RAD26 -deleted cells, however, is not due to reduced expression of the major NER-responsive genes. Interestingly, transcription of the constitutively expressed RPB2 gene is adversely affected in RAD26- deleted cells during UV-induced DNA damage repair. In consonance, chromatin immunoprecipitation analysis showed that unlike in wild type, in RAD26 -deleted cells no significant reduction in RNA polymerase II occupancy occurs during nucleotide excision repair in the transcriptionally active loci like, RPB2 , PYK1 and RPL2B . These results collectively indicate that removal of RNAPII during DNA damage repair following UV irradiation is dependent on Rad26

Investigating RC and Transit Time Limited Bandwidth of Integrated Balanced Detectors through an Equivalent Circuit Model

RC and transit time limited bandwidth of balanced detector is investigated through an equivalent circuit model. While series resistance is not a critical parameter, junction capacitance and load impedance play major roles in resulting bandwidth

Expression analyses of NER genes and <i>RPB2</i> gene.

<p>RT–PCR analysis was performed on total RNA isolated from WT and WTΔRad26 cells (<b>A</b>) following treatment without or with 100 J/m² UV radiation, using gene-specific primers, as described in Materials and Methods section; (<b>B</b>) of <i>RPB2</i> gene after 100 J/m² UV irradiation followed by repair incubation for different time periods. For each strain, data represent the mean ±1 SD for three independent experiments.</p

UV sensitivity of cells.

<p>UV sensitivity of WT, H4 R45H, WTΔRad26 and H4 R45HΔrad26 cells. Colony forming ability following UV irradiation was monitored in exponentially growing cultures. Cells were appropriately diluted, spread on YPD plates, subjected to the UV doses shown and their survival monitored. For each strain, data represent the mean ±1 SD for four independent experiments.</p