Fluorescent carbon dots for sensing applications: a review.

Luminescent carbon dots (CDs) are important class of nanomaterials with fantastic photoluminescence (PL) properties, great biocompatibility, extraordinary solubility in water, minimal expense, and so on. There are many methods for their preparation and they are mainly classed into two groups, top-down and bottom-up approaches. In order to understand the origin of fluorescence in quantum CDs, three mechanisms have been proposed namely molecular state, surface state, and quantum confinement phenomenon.

The Role of Vitamin C: From Prevention of Pneumonia to Treatment of Covid-19.

Vitamins are the main components of our diet. In our nutrition 14 vitamins are present namely A, B1 (Thiamine), B6(Pyridoxine), B12(Cyanocobalamin), C, D, E, K, niacin, folacin, choline, pantothenic acid and biotin. The main role of it is in treating common diseases like cold.

Antiradical Properties of trans-2-(4-substituted-styryl)-thiophene.

2-substituted thiophene compounds with electron donating and electron withdrawing p-phenyl substitution were synthesized and studied their radical scavenging properties using DPPH assay and DFT method. It is shown that p-hydroxy and p-amino phenyl substituted compound exhibit radical scavenging activity. From DFT and radical scavenging studies, a correlation between IC with the bond dissociation enthalpy, proton affinity, ground state dipole moment and optical band gap of compound is found.

Optical properties of 3-substituted indoles.

The optical properties of various donor or acceptor -phenyl substituted ethenyl indoles were studied in solvents of varying polarity using absorption, fluorescence and TDDFT methods. Ethenyl indole exhibits non-linear optical properties (NLO) in a substituent dependent manner. Compound with a strong electron-attracting substituent, shows large NLO properties with charge transfer behavior, whereas ethenyls with moderate electron withdrawing or electron donating substituent exhibit lower NLO properties with non polar excited state.

Tuning of optical properties of p-phenyl ethenyl-E-furans: A Solvatochromism and Density functional theory.

p-Phenyl ethenyl-E-furans (1-6) with varied electron donor and acceptor substituent (NO, CN, Cl, H, OCH, NH) were synthesized and studied the substituent induced optical properties (dipole moment, transition dipole moment, oscillator strength, optical band gap, hyperpolarizability) using Solvatochromism and Density functional theory. It is shown that furan acts as a weak electron donor in presence of an electron withdrawing p‑phenyl substituent (NO, CN, Cl), whereas furan acts as a weak electron acceptor in presence of an electron donating p‑phenyl substituent (OCH, NH). In comparison to ethenylfuran 4, the HOMO-LUMO energy band gap is decreased upon increasing the electron donating or electron withdrawing nature of the phenyl ring.

Substituent Dependent Optical Properties of p-phenyl Substituted ethenyl-E-thiophenes.

Various electron donor and acceptor substituted (NO, CN, Cl, H, OCH, NH) p-phenyl ethenyl-E- thiophenes (1-6) were synthesized and substituent dependent optical properties (dipole moment, transition dipole moment, oscillator strength, optical band gap, hyperpolarizability) were studied using Solvatochromism and Density functional theory. It is shown that thiophene acts as a weak electron donor in presence of an electron withdrawing p-phenyl substituent (NO, CN, Cl), whereas thiophene acts as a weak electron acceptor in presence of an electron donating p-phenyl substituent (OCH, NH). In comparison to ethenyl thiophene 4, the HOMO-LUMO energy band gap is decreased upon increasing the electron donating or electron withdrawing capacity of p-phenyl substituent.

Substituent Dependence Charge Transfer and Photochemical Properties of Donor-Acceptor Substituted Ethenyl Thiophenes.

Donor-acceptor conjugated molecules with efficient light induced properties represent interesting material for electronic device application. In this context, we have calculated excited state dipole moment of three ethenyl thiophenes (1-3) bearing varied electron donor-acceptor substituent in p-phenyl unit using Lippert-Mataga, Bakhshiev and Kawski method. It is found that 1 with strong electron-withdrawing nitro substituent, is exhibiting charge transfer and highly dipolar excited state as compared to 2 and 3.

Genetic analysis of reproductive performance of Frieswal cattle at Military Farm, Ambala.

Aim: This study was carried out to investigate the genetic analysis of reproductive performance of Frieswal cattle at Military Farm, Ambala.

Materials And Methods: A total number of 3005 lactation records of 1147 Frieswal cows over a period of 15 years extending from 1993 to 2007 were used to study at Military Dairy Farm, Ambala. The study period was divided into 5 period of 3 years each.