Multiple Crystal Forms of <i>p</i>‑Aminosalicylic Acid: Salts, Salt Co-Crystal Hydrate, Co-Crystals, and Co-Crystal Polymorphs

Crystallization of <i>p</i>-aminosalicylic acid, an anti-tuberculosis drug, in the presence of pyridine derivatives as coformers led to formation of nine multicomponent solids that include salts, a salt co-crystal hydrate, co-crystals, and co-crystal polymorphs. Seven of them are new solid forms. The influence of the COOH···N_heterocycle synthon is examined in dictating the various crystal forms, the manifestation of which depends on solvent of crystallization and API-coformer composition in solution

Crystal Engineering of Multicomponent Crystal Forms of <i>p</i>‑Aminosalicylic Acid with Pyridine Based Coformers

This work reports detailed structural characterization of 13 new multicomponent solid forms of <i>p</i>-aminosalicylic acid (PAS) with various pyridine based compounds that include eight cocrystals, two salt cocrystals, two salts, and a salt hydrate. The structural chemistry of all solids of PAS with pyridine based coformers including those previously reported were analyzed in terms of PAS–coformer dimer or PAS–coformer–PAS trimer based on the carboxylic acid···pyridine synthon. The robustness of the carboxylic acid···pyridine synthon in the construction of a variety of multicomponent structures, the influence of solution composition and solvent in dictating the outcome of the crystallization event, and the applicability of the Δp<i>K</i>_a rule on a set of 32 PAS based multicomponent solids are also discussed

GROUND COOLING SYSTEM FOR IMPROVING THE EFFICIENCY OF LOW TEMPERATURE POWER GENERATION

This paper presents an analysis of an organic Rankine cycle (ORC) with dry cooling system aided by an earth-coupled passive cooling system. Several organic fluids were considered as working fluids in the ORC in the temperature range of 125-200 degrees C. An earth-air-heat-exchanger (EMU) is studied for a location in the United States (Las Vegas) and another in India (New Delhi), to pre cool the ambient air before entering an air-cooled condenser (ACC). It was observed that the efficiency of the system improved by 1-3% for the system located in Las Vegas and fluctuations associated with temperature variations of the ambient air were also reduced when the EAHE system was used. A ground-coupled heat pump (GCHP) is also studied for these locations where cooling water is pre cooled in an underground buried pipe before entering a condenser heat exchanger in a closed loop. The area of the buried pipe and the condenser size are calculated per kW of power generation for various working fluids

Cryopreserved ovine spermatogonial stem cells maintain stemness and colony forming ability in vitro

Objective: To assess the effect of cryopreservation on stemness and proliferation potential of sheep spermatogonial stem cells (SSCs) in vitro. Methods: Sheep testicular cells were isolated and putative SSCs were enriched by the laminin-based differential plating method. Putative SSCs were co-cultured with the Sertoli cell feeder prepared by the Datura Stramonium Agglutinin (DSA-lectin)-based method. The cultured putative SSCs were cryopreserved in Dulbecco's Modified Eagle Medium-10% fetal bovine serum mixture (DMEM-10% FBS) media containing 10% dimethyl sulfoxide (DMSO) alone or 10% DMSO plus 200 mM trehalose. Cryopreserved putative SSCs were evaluated for their proliferation potential using in vitro culture and stemness by immunocytochemistry. Finally, the transfection ability of cryopreserved putative SSCs was analyzed. Results: We isolated 91% viable testicular cells from sheep testes. The majority of the laminin enriched cells expressed the SSC related marker, ITGA6. Co-culture of sheep putative SSCs with Sertoli cell feeder resulted in the generation of stable colonies, and the expression of SSC marker was maintained after several passages. A significantly higher number of viable putative SSCs was recovered from SSCs cryopreserved in media containing 10% DMSO and 200 mM trehalose compared to 10% DMSO alone (P<0.01). Cryopreserved putative SSCs formed colonies and showed SSC marker expression similar to the non-cryopreserved putative SSCs. The appearance of green fluorescent colonies over the Sertoli cell feeder indicated that cryopreserved sheep SSCs were successfully transfected. Conclusions: Cryopreserved putative SSCs can retain their stemness, colony forming ability, and transfection efficiency in vitro. Our research may help in the effective preservation of germplasm and the generation of transgenic ovine species

Trends of humoral immune responses to heterologous antigenic exposure due to vaccination & omicron SARS-CoV-2 infection: Implications for boosting

Background & objectives: Vaccination and natural infection can both augment the immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but how omicron infection has affected the vaccine-induced and hybrid immunity is not well studied in Indian population. The present study was aimed to assess the durability and change in responses of humoral immunity with age, prior natural infection, vaccine type and duration with a minimum gap of six months post-two doses with either ChAdOx1 nCov-19 or BBV152 prior- and post-emergence of the omicron variant. Methods: A total of 1300 participants were included in this observational study between November 2021 and May 2022. Participants had completed at least six months after vaccination (2 doses) with either ChAdOx1 nCoV-19 or an inactivated whole virus vaccine BBV152. They were grouped according to their age (≤ or ≥60 yr) and prior exposure of SARS-CoV-2 infection. Five hundred and sixteen of these participants were followed up after emergence of the Omicron variant. The main outcome was durability and augmentation of the humoral immune response as determined by anti-receptor-binding domain (RBD) immunoglobulin G (IgG) concentrations, anti-nucleocapsid antibodies and anti-omicron RBD antibodies. Live virus neutralization assay was conducted for neutralizing antibodies against four variants – ancestral, delta and omicron and omicron sublineage BA.5. Results: Before the omicron surge, serum anti-RBD IgG antibodies were detected in 87 per cent participants after a median gap of eight months from the second vaccine dose, with a median titre of 114 [interquartile range (IQR) 32, 302] BAU/ml. The levels increased to 594 (252, 1230) BAU/ml post-omicron surge (P<0.001) with 97 per cent participants having detectable antibodies, although only 40 had symptomatic infection during the omicron surge irrespective of vaccine type and previous history of infection. Those with prior natural infection and vaccination had higher anti-RBD IgG titre at baseline, which increased further [352 (IQR 131, 869) to 816 (IQR 383, 2001) BAU/ml] (P<0.001). The antibody levels remained elevated after a mean time gap of 10 months, although there was a decline of 41 per cent. The geometric mean titre was 452.54, 172.80, 83.1 and 76.99 against the ancestral, delta, omicron and omicron BA.5 variants in the live virus neutralization assay. Interpretation & conclusions: Anti-RBD IgG antibodies were detected in 85 per cent of participants after a median gap of eight months following the second vaccine dose. Omicron infection probably resulted in a substantial proportion of asymptomatic infection in the first four months in our study population and boosted the vaccine-induced humoral immune response, which declined but still remained durable over 10 months