NaYF4:Ho3+/Yb3+@NaGdF4 core@shell upconversion nanoparticles for contrast enhancement in bimodal in-vitro OCT imaging.

Contrast enhancement is explored in optical coherence tomography images using core NaYF4:Ho3+/Yb3+ and core@shell NaYF4:Ho3+/Yb3+@NaGdF4 nanoparticles. Under 980 nm excitation, core@shell nanoparticles exhibited 2.8 and 3.3 times enhancement at 541 nm and 646 nm emission wavelengths of Ho3+ ions compared to core nanoparticles. Photo-thermal conversion efficiencies were 32% and 20% for core and core@shell nanoparticles. In swept-source optical coherence tomography (SSOCT), core@shell nanoparticles have shown superior contrast, while in photo-thermal optical coherence tomography (PTOCT) core nanoparticles have excelled due to their higher photo-thermal conversion efficiency. The enhancement in contrast to noise ratio obtained is 58 dB. Comparative assessments of scattering coefficients and contrast-to-noise ratios were conducted, providing insights into nanoparticle performance for contrast enhancement in optical coherence tomography.

In-situ oil-spill remediation by an electrodeposited superhydrophobic copper mesh.

The present study aims to combat the problem of oil in water pollution via its separation using a superhydrophobic copper mesh. An ecofriendly superhydrophobic copper mesh with a water contact angle of 166 ± 2° is developed by a facile two-step process (electrodeposition followed by coating). The coated mesh with mechanical robustness, chemical endurance and thermal stability is a promising choice for real-world conditions. Additionally, its resistance to corrosion in harsh chemical environments ensures its long-term durability. With a separation efficiency of 99.9 %, the coated mesh serves as an efficient medium for oil-water separation. It can be used as a reusable filtering medium with high separation efficiency in alkali and neutral environments. Besides, it is also competent for continuous oil-water separation and collection of oil from wastewater. Thus, the above study clearly manifests that the coated mesh holds tremendous potential for large-scale oil spill cleanup.

Assessment of NIR-triggered PEG-coated NaGdF4:Tm3+/Yb3+bio-compatible upconversion nanoparticles for contrast enhancement in OCT imaging and optical thermometry.

In this investigation, we embarked on the synthesis of polyethylene glycol coated NaGdF4:Tm3+/Yb3+upconversion nanoparticles (UCNPs), aiming to assess their utility in enhancing image contrast within the context of swept source optical coherence tomography (OCT) and photo-thermal OCT imaging. Our research unveiled the remarkable UC emissions stemming from the transitions of Tm3+ions, specifically the1G4→3H6transitions, yielding vibrant blue emissions at 472 nm. We delved further into the UC mechanism, meticulously scrutinizing decay times and the nanoparticles' capacity to convert radiation into heat. Notably, these nanoparticles exhibited an impressive photo-thermal conversion efficiency of 37.5%. Furthermore, our investigations into their bio-compatibility revealed a promising outcome, with more than 90% cell survival after 24 h of incubation with HeLa cells treated with UCNPs. The nanoparticles demonstrated a notable thermal sensitivity of 4.7 × 10-3K-1at 300 K, signifying their potential for precise temperature monitoring at the cellular level.

Breeding of Aedes aegypti and its Impact on Dengue/DHF in Rural Areas.

A survey was undertaken to ascertain the Aedes indices in Ashawati and Tauri villages of Faridabad and Gurgaon districts of Haryana state, India, during September 1996. The House Index, Container Index and Breteau Index recorded in Tauru village were 33.3, 21.0 and 40.0, while in Ashawati village these indices were 13.6, 2.8 and 10.3 respectively.

Dengue Outbreak in Ludhiana (Punjab), India,1996.

An outbreak of dengue fever/dengue haemorrhagic fever was reported from Ludhiana city in Punjab state, India, during October 1996. The outbreak started in the last week of September and lasted up to the first week of December. The number of cases reported during the outbreak was 720, with 19 deaths. A community survey revealed a very high attack rate of fever cases (4.10%). Serological tests suggested a recent dengue virus infection as seven serum samples out of nine tested were found to be positive. Aedes survey carried out in some of the affected localities revealed the presence of Aedes aegypti, a vector mosquito. The values of House and Container indices in Ludhiana city during the survey were 32.8% and 29.16% respectively. Breeding of Aedes mosquitoes was detected in various types of containers, mostly desertcoolers. To prevent such outbreaks in the state of Punjab and in the region, there is an urgent need for taking appropriate preventive measures and for disease/vector surveillance.