Effect of Methods and Catalysts on the One-pot Synthesis of Tetrahydropyridine Derivatives: A Mini-Review

As heterocyclic nitrogen molecules, tetrahydropyridines have been recognized as significant constituents of many natural and synthetic compounds, many of which have interesting biological and pharmacological properties. Tetrahydropyridines (THPs) play a pivotal role in synthesizing a range of remedial compounds. They have exhibited impressive curative efficacy for the treatment of numerous diseases. Due to this reason, they are attractive synthetic targets for organic chemists. Several techniques and schemes have been adopted for the synthesis of these molecules. Among these, multicomponent reactions (MCRs) are proved to be one of the best tools for achieving compounds containing complex diversity in a single step and production of their vast libraries. Along with this, the employment of various catalysts makes this technique more vibrant. This review article discussed different catalysts adopted in the synthesis of tetrahydropyridine derivatives via multicomponent reactions to provide information for the development of new-fangled processes aiming at less reaction time, better yield, and minimum side effects. DOI: http://dx.doi.org/10.17807/orbital.v13i4.158

Vision screening among hearing-impaired school children in Biratnagar, Nepal

Background: The prevalence of hearing impairment in Nepal is 16.5%, affecting approximately 2.71 million people. Deaf children are visually dependent, and even a mild refractive error may cause visual discomfort. The goal of this study was to determine the need for vision screenings in schools for the hearing impaired in Biratnagar, Nepal. Methods: A cross-sectional study was conducted with permission from Birat Deaf Secondary School, Biratnagar, Nepal. A total of 130 hearing-impaired students were examined. Non-invasive, comprehensive optometric examinations were performed to detect visual disorders. When a more detailed evaluation was needed, the students were referred to the Pediatric Ophthalmology Department, Biratnagar Eye Hospital Biratnagar, Nepal. Results: Of the 130 hearing-impaired students, 58 (44.6%) were male and 72 (55.4%) were female. The mean ± standard deviation of age was 16.03 ± 3.8 years (range 6–25 years). Twenty-one (16.1%) students had refractive errors: 13 (10%) had myopia, 7 (5.4%) had hyperopia, and 1 (0.8%) had anisometropia. In the cover test, 88 (67.7%) had orthophoria, 19 (14.6%) had exophoria, 11 (8.5%) had esophoria, 5 (3.85%) had exotropia, and 3 (2.3%) had esotropia. Cover tests were not performed in 4 (3.1%) students, as they were unable to fixate due to nystagmus or decreased vision. On ocular examination, 20 (15.3%) students had anterior segment abnormalities, including lid abnormality, conjunctivitis, Bitot’s spots, pterygium, corneal opacity, and lenticular opacity. Posterior segment or retinal abnormalities were found in four students with one having Usher syndrome. Color vision defects, nystagmus, and amblyopia were found in 8 (6.1%), 2 (1.5 %), and 1 (0.8%), respectively. Conclusions: The findings of the present study reflect the need of periodic vision screenings in schools for the hearing impaired in Nepal. These children are at a high risk of vision impairment. How to cite this article: Sah SK, Thakur R, Adhikari PR. Vision screening among hearing-impaired school children in Biratnagar, Nepal. Med Hypothesis Discov Innov Optom. 2021 Spring; 2(1): 36-40. DOI: https://doi.org/10.51329/mehdioptometry123 &nbsp

Engineered nanoparticles (ENPs): Unexplored potential and limitations

The rapid growing industry of global economic importance is exploring the novel material synthesized at the nanoscale. Engineered nanoparticles (ENPs) have been manufactured with specific shape, size, surface properties and unique functionalities such as catalytic behaviour, increased strength, improved thermal and electrical conductivity. These advancements have opened the door to new applications in biomedicine, nanoenergetic materials and functional nanocomposites including cancer therapy, drug delivery, tissue engineering, regenerative medicine, biomolecule detection, and antimicrobial activities. In cancer therapies, nanoparticulate delivery systems allow ENPs greater penetration of therapeutic and diagnostic substances within the body while posing fewer risks than conventional cancer therapies. Evidences suggested that ENPs offer some substantial danger to the environment by its toxicological effects when they are exposed to the environment, which leads to the chronic issues of nanopollution. The aquatic environment is at the greatest risk from ENPs, as it serves as a sink for nearly all environmental contaminants. Despite these challenges, ENPs holds promise to in different field as well as minimize environmental pollution, by employing the innovative environmental remediation methods. There are gaps in understanding the fate of ENPs in the environment hence more stringent and critical research is the need of the hour. It also call for the advancement of tools and techniques that can accurately quantify and analyze the uptake of ENPs into biological systems.This review includes the different types of ENPs their sources and physiochemical characteristics and the ultimate fate of these ENPs in the environment

Synthetic investigations in epimerization reactions of β-lactams

A novel and facile synthesis of cis-3-phenylthio & cis-3-chloro-β-lactams using epimerization reaction has been studied. The optimized reaction conditions for this conversion using very mild base have been studied. All the new synthesized compounds have been characterized. The reported work gives easy conversion of trans isomers to cis without forming any side product

Beekeeping with Apis cerana: An indigenous tradition of tribal areas of Chamba district (Himachal Pradesh)

367-372Traditional beekeeping in Chamba is very primitive. This paper provides evidence besides focusing on the traditional methods adopted by the local beekeepers of Chamba district and their inherited traditional knowledge of beekeeping with Apis cerana. The cluster data of 250 traditional beekeepers were collected from 25 villages of five development blocks of Chamba district during 2018-2019. The suitable agro-climatic conditions, plenty of wild as well as cultivated bee flora and their traditional knowledge offer vast potential for the development and success of apiculture in the district. The traditional wall hives, known as Ganar, are made on the walls of the under-construction/newly constructing kachha houses by keeping space (25-30 cm x 25-30 cm). The size of log hives depends upon the tree truck collected from the forest. Honey harvesting is done in a rational way by squeezing the combs, hence destructions of beehives. Cleaning of hives is done with raw comb mixed with flower extracts or juniper/ pine needles, which in turn helps them to attract swarms. Unfortunately, traditional beekeeping of A. cerana is under threat due to the construction of pucca houses and the lack of scientific knowledge of beekeeping of the traditional beekeepers

Protective Role of Ashwagandha Leaf Extract and Its Component Withanone on Scopolamine-Induced Changes in the Brain and Brain-Derived Cells

BACKGROUND:Scopolamine is a well-known cholinergic antagonist that causes amnesia in human and animal models. Scopolamine-induced amnesia in rodent models has been widely used to understand the molecular, biochemical, behavioral changes, and to delineate therapeutic targets of memory impairment. Although this has been linked to the decrease in central cholinergic neuronal activity following the blockade of muscarinic receptors, the underlying molecular and cellular mechanism(s) particularly the effect on neuroplasticity remains elusive. In the present study, we have investigated (i) the effects of scopolamine on the molecules involved in neuronal and glial plasticity both in vivo and in vitro and (ii) their recovery by alcoholic extract of Ashwagandha leaves (i-Extract). METHODOLOGY/PRINCIPAL FINDINGS:As a drug model, scopolamine hydrobromide was administered intraperitoneally to mice and its effect on the brain function was determined by molecular analyses. The results showed that the scopolamine caused downregulation of the expression of BDNF and GFAP in dose and time dependent manner, and these effects were markedly attenuated in response to i-Extract treatment. Similar to our observations in animal model system, we found that the scopolamine induced cytotoxicity in IMR32 neuronal and C6 glioma cells. It was associated with downregulation of neuronal cell markers NF-H, MAP2, PSD-95, GAP-43 and glial cell marker GFAP and with upregulation of DNA damage--γH2AX and oxidative stress--ROS markers. Furthermore, these molecules showed recovery when cells were treated with i-Extract or its purified component, withanone. CONCLUSION:Our study suggested that besides cholinergic blockade, scopolamine-induced memory loss may be associated with oxidative stress and Ashwagandha i-Extract, and withanone may serve as potential preventive and therapeutic agents for neurodegenerative disorders and hence warrant further molecular analyses

M1 muscarinic receptor is a key target of neuroprotection, neuroregeneration and memory recovery by i-Extract from Withania somnifera

Memory loss is one of the most tragic symptoms of Alzheimer's disease. Our laboratory has recently demonstrated that 'i-Extract' of Ashwagandha (Withania somnifera) restores memory loss in scopolamine (SC)-induced mice. The prime target of i-Extract is obscure. We hypothesize that i-Extract may primarily target muscarinic subtype acetylcholine receptors that regulate memory processes. The present study elucidates key target(s) of i-Extract via cellular, biochemical, and molecular techniques in a relevant amnesia mouse model and primary hippocampal neuronal cultures. Wild type Swiss albino mice were fed i-Extract, and hippocampal cells from naïve mice were treated with i-Extract, followed by muscarinic antagonist (dicyclomine) and agonist (pilocarpine) treatments. We measured dendritic formation and growth by immunocytochemistry, kallikrein 8 (KLK8) mRNA by reverse transcription polymerase chain reaction (RT-PCR), and levels of KLK8 and microtubule-associated protein 2, c isoform (MAP2c) proteins by western blotting. We performed muscarinic receptor radioligand binding. i-Extract stimulated an increase in dendrite growth markers, KLK8 and MAP2. Scopolamine-mediated reduction was significantly reversed by i-Extract in mouse cerebral cortex and hippocampus. Our study identified muscarinic receptor as a key target of i-Extract, providing mechanistic evidence for its clinical application in neurodegenerative cognitive disorders

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Randomized Clinical Trial of High-Dose Rifampicin With or Without Levofloxacin Versus Standard of Care for Pediatric Tuberculous Meningitis: The TBM-KIDS Trial

Background. Pediatric tuberculous meningitis (TBM) commonly causes death or disability. In adults, high-dose rifampicin may reduce mortality. The role of fluoroquinolones remains unclear. There have been no antimicrobial treatment trials for pediatric TBM. Methods. TBM-KIDS was a phase 2 open-label randomized trial among children with TBM in India and Malawi. Participants received isoniazid and pyrazinamide plus: (i) high-dose rifampicin (30 mg/kg) and ethambutol (R30HZE, arm 1); (ii) high-dose rifampicin and levofloxacin (R30HZL, arm 2); or (iii) standard-dose rifampicin and ethambutol (R15HZE, arm 3) for 8 weeks, followed by 10 months of standard treatment. Functional and neurocognitive outcomes were measured longitudinally using Modified Rankin Scale (MRS) and Mullen Scales of Early Learning (MSEL). Results. Of 2487 children prescreened, 79 were screened and 37 enrolled. Median age was 72 months; 49%, 43%, and 8% had stage I, II, and III disease, respectively. Grade 3 or higher adverse events occurred in 58%, 55%, and 36% of children in arms 1, 2, and 3, with 1 death (arm 1) and 6 early treatment discontinuations (4 in arm 1, 1 each in arms 2 and 3). By week 8, all children recovered to MRS score of 0 or 1. Average MSEL scores were significantly better in arm 1 than arm 3 in fine motor, receptive language, and expressive language domains (P < .01). Conclusions. In a pediatric TBM trial, functional outcomes were excellent overall. The trend toward higher frequency of adverse events but better neurocognitive outcomes in children receiving high-dose rifampicin requires confirmation in a larger trial. Clinical Trials Registration. NCT02958709