In a free space optical (FSO) communication link from satellite to ground, the losses in the channel will be dynamic. Thus, the characterization of the FSO channel is of great importance, and this can be emulated in the lab to evaluate the realistic performance of a satellite payload. In this work, we introduce a novel optical channel emulator capable of replicating these dynamics, especially for Low Earth Orbit-based CubSats. We demonstrate its ability to accurately emulate a satellite-to-ground optical communications channel under various atmospheric turbulence strengths, satellite trajectories, and optical ground station parameters at a given optical wavelength of interest. Our satellite channel emulator was designed to test and benchmark the performance of the continuous variable quantum key distribution payload for the Satellite Platform for Optical Quantum Communications mission-an in-orbit demonstrator for the UK's Quantum Communication Hub, to be launched in early 2026. Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Power consumption is a critical constraint for CubeSat based quantum communication, where tracking systems often dominate the onboard power budget. We demonstrate an energy-efficient approach that enables reliable satellite tracking at substantially reduced beacon power by treating tracking as a weak-signal estimation task. Using a closed-loop system with fine steering mirrors and higher-order Kalman filters on ground, we can maintain stable tracking at a transmitted power equivalent to 34 mW over a -60 dB satellite to ground optical channel. Our results show that the resulting penalties on QKD bit error rates and signal-to-noise ratios are negligible, allowing for more efficient power allocation to quantum payloads in CubeSat missions.

The necessity of random numbers for various tasks, from simulation to cryptography, is crucial and immense. Here we demonstrate CV-QRNG using the CV payload of the SPOQC mission. The homodyne setup for QRNG uses the laser from the payload, in addition to potentially being used as detector in the case of an uplink scenario. Here we quantify the extractable secure randomness from the QRNG setup, that involves homodyne measurement of the vacuum states. The extracted randomness is tested against NIST test suite in addition to formally upper bounding the min-entropy. With the raw key length being ≈1 Mb in a given satellite pass, we get a total length of ≈19.5 Kb of certified random numbers from the 12-bit ADC.

In space based quantum key distribution (QKD) protocols, the quantum channel will be dynamic in nature and the channel loss will change with respect to the zenith angle. In the context of continuous variable (CV)-QKD, this will cause issues with parameter estimation and for a transmitted local oscillator in particular it will also fluctuate the shot noise. Therefore, it is vital to characterise this channel loss and the sources of this loss. In this paper the varying channel loss is characterised under practical assumptions. This is shown for various different scenarios, turbulence strengths, as well as wavelengths. This work shows, for the channel parameters considered, it is possible to generate a positive secret key if restricted Eve security assumptions are made.

Herein, we report an efficient three-component one-pot cascade protocol for the synthesis of pyrimidinone thiazole bifunctional hybrids in good yields. This transformation presumably occurs via in situ cyclocondensation of the 5-amino-pyrimidinones, a variety of aldehydes and thioglycolic acid. The optimized procedures are simple to operate, mild, and successful with a wide range of substrates.

In Local-local Oscillator (LLO) based Continuous-Variable Quantum Key Distribution (CV-QKD), the phase reference of the transmitter and receiver, Alice and Bob, are naturally de-correlated due to their use of individual lasers. A phase reference signal is used, whose measurement is critical for estimating the phase difference and correcting the raw QKD data. We observed that asymmetry in the quadrature measurements of the shot noise-limited heterodyne detector affects the accuracy of the reference signal's phase estimation and thereby reduces the achievable transmission distance and key rate of the CV-QKD system. We quantify the effect and propose a method to counteract the effect of detection asymmetry. We also evaluate the effects of detection asymmetry using quantum optical tomography.

We propose a simplified measurement scheme for a Gaussian modulated coherent state (GMCS) protocol for continuous variable quantum key distribution (CV-QKD), utilizing homodyne detection without quadrature switching. The reference frame of measurement is taken to be at an arbitrary angle, however, reconciliation converges the proposed scheme to GMCS with switching quadrature protocol. The arbitrary frame of measurement could also include the unknown random thermal drift within Bob's optical measurement setup. We found this scheme is advantageous for practical free-space and fiber-based GMCS protocol-based CV-QKD systems as it does not require a phase modulator for random measurement selection quadrature at Bob.

Over-expression of sigma-2 receptor in cancer cells provides an opportunity to develop molecular probes for diagnosis, even for non-receptor specific malignancies like triple negative breast cancers. In this work, a novel sigma-2 receptor ligand [THQ-DTPA] has been synthesized and characterized using 6,7-dimethoxy-1,2,3,4-tetra-hydroisoquinoline (THQ) and diethylenetriaminepentaacetic acid (DTPA). The ligand is further chelated with 99mTc for application as metal based radiotracer [99mTc-THQ-DTPA]. Radiolabelling with 99mTc was achieved in an excellent yield of 98.0 +/- 0.5% using stannous chloride as a reducing agent. The radioligand was found to be stable in human serum up-to 24 h, bio-compatible with less than 4% hemolysis, and exhibited high binding with sigma receptors isolated from rat liver membrane (Kd of 16.32 +/- 4.93 nM and Bmax of 0.5232 +/- 0.06 pmol/mg). Bio-distribution studies in triple-negative breast tumor bearing nude mice showed high tumor uptake after 30 min of injection with tumor/muscle (T/M) ratio of 3.58 +/- 0.09. At 240 min, the T/M ratio (2.84 +/- 0.20) decreased by 35% when administered in sigma blocked tumor bearing mice (1.81 +/- 0.16) suggesting the selectivity of the ligand. Tumor imaging in gamma camera indicated a contrast of 3.56 at 30 min p.i. The above findings indicate that the ligand 99mTc-THQ-DTPA binds to sigma-2 receptors with high affinity and has potential for triple-negative breast tumor imaging.

AbstractA greener, safer, and more efficient methodology for the synthesis of (Z)‐5‐benzylidene‐2‐thioxothiazolidin‐4‐ones (3 a–u) and (Z)‐5‐benzylidenethiazolidine‐2,4‐diones (4 a–i) has been developed. The deep eutectic solvent (DES) ZnCl2/urea used as a greener solvent as well as a catalyst in this study accelerated the condensation of rhodanine and thiazolidine‐2,4‐dione with different aldehydes to afford the target scaffolds in excellent yields (88‐98 %). The reaction methodology adopted offered significant advantages such as mild reaction conditions, functional group tolerance, quick reaction time, column‐free isolation, catalytic recyclability, and applicability to gram‐scale production. Moreover, density function theory calculations were carried out to investigate the global reactivity and stability profiles of these compounds. Finally, the green metrics analysis supported the greener nature of the present methodology.

This poster presentation demonstrates the quantum random number generation (QRNG) from a shotnoise-limited homodyne detector. The detector is part of the continuous variable quantum key distribution (CVQKD) payload developed for the Satellite Platform for Optical Quantum Communications (SPOQC) mission. We also show how the onboard homodyne detector works as a CVQKD receiver on the satellite.

The reported work presents the diastereo, regio-, and pi-facial selective synthesis of hetero-Diels-Alder (H-DA) cycloadducts with diazene derivatives viz. di-isopropyldiazocarboxylate and diethylazodicarboxylate with cis/trans-3-butadienyl-beta-lactams having stereocentres at its alpha and beta-position. The H-DA reactions resulted in the formation of beta-lactam tethered-3,6-dihydro-pyridazines in good yields.

The future quantum internet will leverage existing communication infrastructures, including deployed optical fibre networks, to enable novel applications that outperform current information technology. In this scenario, we perform a feasibility study of quantum communications over an industrial 224 km submarine optical fibre link deployed between Southport in the United Kingdom (UK) and Portrane in the Republic of Ireland (IE). With a characterisation of phase drift, polarisation stability and the arrival time of entangled photons, we demonstrate the suitability of the link to enable international UK–IE quantum communications for the first time.

Light-promoted methodologies can be considered ideal protocols for green and environment-friendly oxidation of alcohols, unlike many traditional methods and reagents that are toxic, hazardous, and low-yielding with tedious work up. The visible-light-induced photo redox catalysis to produce radical species has a broad scope in the selective oxidation of alcohols into their carbonyl compounds that have a broad application in industries and synthetic chemistry. In this comprehensive review, we targeted articles focused on photocatalytic transformations of primary aromatic alcohols to respective aldehydes. The photoconversion of alcohols into aldehydes was accelerated by MOF-hybrids, metal hybrids, metal oxides, and metal free catalysts. Overall, the present manuscript involves the different aspects of light promoted oxidation reactions of aromatic alcohols employing varied photocatalysts. This study also includes the critical analysis of the different reports available along with comparative account.

Photoreduction of CO2 into valuable fuels using semiconductors has been known as a potential mean to simultaneously alleviate environmental and energy issues. Z-scheme photocatalytic systems can realize spatial separation of photogenerated charges and ensure strong redox capability simultaneously. Particularly, the all-solid-state Z-scheme photocatalysts for non aqueous redox mediators have been widely used for CO2 reduction. This review provides a comprehensive outlook of the essential components and recent advancements in all-solid-state Z-scheme systems designed for the photocatalytic reduction of CO2, including indirect Z-scheme, direct Z-scheme system, and mechanism on Z-scheme surface. Finally, a brief outlook on the challenges and novel courses within this domain is presented, which will give a rational guideline to improve the efficiency of hybrid photocatalysts for Z-scheme CO2 reduction.

The utilisation of botanical materials and microorganisms in nanoparticle (NPs) synthesis has emerged as an environmentally sustainable alternative when compared to conventional methodologies which include various hazardous chemical agents. These eco-friendly NPs have recently received attention due to their potential applications across diverse fields. Multiple investigations have also demonstrated the efficacy of environmentally-friendly synthesised nanoparticles in various medical applications, including targeted drug delivery, cancer therapy, and wound healing. Furthermore, green-synthesised nanoparticles exhibit promising potential in the environmental remediation, owing to their remarkable photodegradation capabilities. These photocatalysts harnesses light to transform the pollutants into benign byproducts. Green NPs have demonstrated exceptional effectiveness in degrading various contaminants, encompassing heavy metals, herbicides, and dyes. The biogenic synthesis of NPs using microbes and plant-derived materials represents an affordable, environmentally beneficial, and biologically safe approach. Several NPs have been fabricated through the bio-reduction of biological substances or their extracts. Metallic NPs produced through natural means exhibit diverse biological and environmental applications, including adsorption, photocatalysis, and water purification. These sustainable and environmentally friendly protocols have captured significant attention from the scientific community over the past decade. This comprehensive review serves as a consolidated reference, summarising current and relevant research findings pertaining to the biogenic synthesis of nanoparticles and their prospective applications in environmental contexts.

Type 2 Diabetes continues to be one of the major public health issues worldwide without any sustainable cure. The modulation of gut microbiota is believed to be caused by probiotic bacteria and several probiotic strains have previously shown antidiabetic activity. The present study aims to isolate potential probiotic bacteria from traditionally used fermented rice beer of Assam, India and to investigate its anti-hyperglycemic effect. Of the 20 isolated bacterial isolates, 5 isolates showed potential probiotic activities, of which, 2 isolates viz. Bacillus sp. FRB_A(A) and Acetobacter sp. FRB_B(S) showed good in vitro anti-oxidant and anti α-glucosidase activities. Based on the in vitro results, isolate Bacillus sp. FRB_A(A) was further used to evaluate the antidiabetic activity in streptozotocin induced diabetic rat model. After 21 days, the blood glucose level in diabetic rats with probiotic administration significantly lowered from 458.00 ± 46.62 mg/dl to 108.20 ± 6.76 mg/dl (p < 0.001), whereas, in diabetic rats without probiotic remained high (576.20 ± 29.48 mg/dl). On analyzing the endogenous antioxidant profile in various tissues of the experimental rats, reduced lipid peroxidation, glutathione level and superoxide dismutase and glutathione peroxidase activity were observed in probiotic administered rats in comparison to the streptozotocin treated diabetic controls. In conclusion, the bacteria Bacillus sp. FRB_A(A) isolated from fermented rice beer possesses probiotic attributes and exhibits significant anti-hyperglycemic activities.

An economical and environment-friendly protocol involving the use of ultrasonic vibrations was developed for the synthesis of a series of diaryl-4-thiazolidinones. The highlights of the developed approach are significant enhancement in the product yield, short reaction time, solvent-free, free of any toxic metal as a catalyst, cheaper synthetic methodological approach as well as non-formation of side-products. The developed approach is useful in terms of immense biological relevance of thiazolidines as well as the greener approach for cyclo-condensation of functionalized imines with thioglycolic acid.

The manuscript presents an efficient method for the synthesis of various cis-azetidin-2-ones with high regio- and diastereoselectivity. This approach utilizes Kinugasa reaction involving diverse functionalized nitrones, including diaryl nitrones and α,β-unsaturated nitrones, in conjunction with acetylenic alcohols. Copper (I) serves as a catalyst to facilitate the transformation.

Background: In our study, we examined the 5-year survival of OSCC patients with HPV positive or negative status along with p16 protein expression. Method: A total of 72 biopsy tissue specimens from histologically confirmed oral squamous cell carcinoma (OSCC) patients were collected. HPV detection and genotyping were performed using HPV E6/E7 and HPV- type-specific multiplex primer for nested-PCR. Immunohistochemistry evaluation of pl6 was conducted. SPSS statistical software (ver 20) was used for data analysis. Results: High risk-HPV (hr-HPV) DNA positivity was found in 27.7% (n = 20) of OSCC patients. Stage III OSCC patients were 7.80 times more likely to survive 5 years than stage IV patients (OR-7.80 CI-95%; P-0.03). Among the hr-HPV positive OSCC patients, we found that the median survival time for the 1st year (95%), 3 years (78.5%), and 5 years (38.5%) was significantly higher than that of the hr-HPV negative [1st year (78.6%), 3 years (45.2%) and 5 years (38.5%)] OSCC patients (P-0.03 The survival of male patients with hr-HPV positive OSCC is 9.75 times greater than the survival of patients with HPV negative OSCC (OR-9.75; CI-95%; P-0.05). The p16 expression level (low to overexpression) group and negative P16 expression group of OSCC patients have not demonstrated a significant association with 5-year survival. Conclusion: We conclude that in OSCC cases of North-East India, the presence of hr-HPV in OSCC cases could be a good predictor of 5-year survival rate. Expression of p16 does not appear to have any significant association with 5-year survival.