Showing papers by "Vinod K. Singh published in 2022"
TL;DR: A novel organocatalytic asymmetric formal [3 + 2] cycloaddition of 3-substituted 1H-indoles with in situ generated 3-hydroxy-isoindolinone-derived β,γ-alkynyl-α-ketimines has been developed and several interesting transformations of the products have been demonstrated.
8 citations
TL;DR: In these pandemic times, the patients who present with altered mentation and polyfocal neurological deficits and background history of recent COVID-19 infection or recipient of SARS-CoV-2 vaccine the diagnosis of acute disseminated encephalomyelitis (ADEM) should be considered likely.
Abstract: Abstract A 40-year-old woman known hypertensive presented with progressive ascending paralysis. MRI T2W and FLAIR screening of the brain demonstrated swelling with altered signal in the visual cervical cord, medulla, and another juxtacortical lesion in the right temporal lobe with possibility of a demyelinating etiology. CSF testing did not identify a direct cerebral infection. High-dose steroids followed by a course of IVIG was administered but with no significant response. In these pandemic times, the patients who present with altered mentation and polyfocal neurological deficits and background history of recent COVID-19 infection or recipient of SARS-CoV-2 vaccine the diagnosis of acute disseminated encephalomyelitis (ADEM) should be considered likely How to cite this article Kumar A, Sabharwal P, Gupta P, Singh VK, Rao BK. A Fatal Case of Acute Disseminated Encephalomyelitis: A Diagnosis to Ponder in Pandemic. Indian J Crit Care Med 2022;26(4):518–520.
3 citations
TL;DR: Interestingly, changing the alpha-substituents of the iminoesters from an aryl to an aliphatic (benzyl) group or hydrogen resulted in the formation of normal (3+2) cycloaddition products, also in excellent enantioselectivities.
2 citations
TL;DR: In this paper , an organocatalytic cascade approach for the synthesis of spiro-cyclopropyl oxindole derivatives has been developed based on asymmetric vinylogous Michael addition of 4-nitroisoxazole derivatives to N-Boc isatylidene malonates followed by intramolecular alkylation.
Abstract: A novel organocatalytic cascade approach for the synthesis of spiro-cyclopropyl oxindole derivatives has been developed. The methodology is based on asymmetric vinylogous Michael addition of 4-nitroisoxazole derivatives to N-Boc isatylidene malonates followed by intramolecular alkylation. Its remarkable stereocontrol, wide substrate scope, and scalability highlight this new developed strategy. Moreover, this work represents the first example of vinylogous Michael initiated ring closure (MIRC) reaction for the synthesis of chiral 3,3'-cyclopropyl oxindole.
1 citations
TL;DR: In this article , the authors have used n-type diamane as an emitter layer and the nature of diamane has been considered 3D in spite of 2D as well as electronic nature of the diamane is considered isotropic.
Abstract: In the presented work, cell's parameter of heterostructure silicon solar cell modelled as: ITO (front contact)/n-Dn/p-cSi/Ag under the illumination of monochromatic light at standard spectrum AM-1.5 G, has been optimized by using AFORS-HET v 2.5 software. We have used n-type diamane as an emitter layer and the nature of diamane has been considered 3D in spite of 2D as well as electronic nature of diamane is considered isotropic. To ensure that Schottky junction has been formed at interface, the electric contacts have been made along the c-axis so that maximum charge carriers get collected. To obtain the high efficiency, various parameters of n-type diamane as well as p-type c-Si layers have been optimized and the maximum efficiency of 16.84% has been obtained for single layer n-diamane at 100 µm thick silicon wafer. We also investigated the spectral response and dependency of temperature on the performance of exclusively designed solar cell and we obtained the best efficiency 16.84% at 300 K temperature. In order to check the performance on commercially available silicon we have optimized the same solar cell by considering the parameters of commercially available p-type crystalline silicon layer and maximum efficiency 10.41% was achieved. After getting the maximum efficiency 16.84% we further carried out the simulation by optimizing the layer numbers of n-diamane and found decrement in the efficiency up to 15.3% which indicates that, efficiency slightly decreases as layer number increases. We have demonstrated that n-type diamane might be used as an effective emitter layer in crystalline Si heterojunction solar cell.
1 citations
TL;DR: A Fatal Case of Acute Disseminated Encephalomyelitis—A Diagnosis to Ponder in Pandemic is presented.
Abstract: How to cite this article: Kumar A, Sabharwal P, Gupta P, Singh VK, Rao BK. Reply to Letter to the Editor: A Fatal Case of Acute Disseminated Encephalomyelitis—A Diagnosis to Ponder in Pandemic. Indian J Crit Care Med 2022;26(9):1062.
TL;DR: The diagnosis of toxocariasis is essentially clinical, based on the lesion morphology and supportive laboratory data such as serum enzyme-linked immunosorbent assay (ELISA) titers and ELISA Toxocara titers on aqueous humor; other diagnostic methods are imaging studies including optical coherence tomography, fluorescein angiography, computed tomography and ocular ultrasound as mentioned in this paper .
Abstract: Ocular toxocariasis is an uncommon worldwide parasitic infection that affects mostly children and is found in both rural and metropolitan areas. In many parts of the world, parasitic infections of the eye are a major cause of blindness. The diagnosis of toxocariasis is essentially clinical, based on the lesion morphology and supportive laboratory data such as serum enzyme-linked immunosorbent assay (ELISA) titers and ELISA Toxocara titers on aqueous humor; other diagnostic methods are imaging studies including optical coherence tomography, fluorescein angiography, computed tomography, and ocular ultrasound. Treatment is directed at complications arising from intraocular inflammation and vitreous membrane traction. Early vitrectomy may be of value both diagnostically and therapeutically.
TL;DR: In this paper , a facile methodology was demonstrated for the synthesis of isoindolinones containing the N,S-acetal framework by employing a Brønsted acid catalyst with a three-component reaction.
Abstract: A facile methodology was demonstrated for the synthesis of isoindolinones containing the N,S-acetal framework by employing a Brønsted acid catalyst with a three-component reaction. The reaction proceeded via the addition of thioacid to in situ-generated aldimine followed by lactamization, which involved the formation of one C-S bond and two C-N bonds under easily controlled and ambient reaction conditions. A variety of substituted isoindolinones were synthesized with up to 99% yields. Furthermore, the importance of this methodology was also justified by a gram-scale synthesis and demonstration of some interesting synthetic transformations.
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TL;DR: In this paper , the influence of diluent on carboxylic acid extraction equilibrium is also studied theoretically, and the possibility of estimating the equilibrium parameters using an evolutionary optimization method [differential evolution (DE)] is not investigated.
Abstract: This article research does not cover all of the potential uses for carboxylic acid molecules. Compounds that develop, break down, absorb, or release into the environment have a powerful effect on all the activities and reactions that take place in the body and the environment. As a concluding point, the carboxyl functional group and all of its derivatives are inseparable from life on this planet. Molecules with the carboxyl functional group linked to the hydrocarbon radical include carboxylic acids or organic acids. In the extraction of acids, different extraction and diluent compositions are used in various ways. The stoichiometry of reactive extraction, equilibrium parameters, and kinetic parameters can all be determined using a variety of models. The influence of diluent on carboxylic acid extraction equilibrium is also studied theoretically. I. OVERVIEW Carboxylic acids are significant chemicals that are frequently utilised as acidulants in food and beverage production, pharmaceuticals, and the chemical industry. Industrial production of carboxylic acids is carried out using the petrochemical feedstock. These acids are also produced by biotechnology based processes (fermentation processes), which uses renewable resources. Adapted downstream processing for product separation is required as the importance of biological production grows, with novel pathways and increased production rates. In order to make fermentation a realistic option, new fermentation procedures utilising extremely efficient separation techniques must be developed. As far as industrial and environmental considerations are concerned, removing mono-carboxylic acids like formic, acetic, and propionic acid from wastewater is also critical. It's common for extraction to be the best method for simultaneously removing a product from a solution (liquid extraction, ultrafiltration, reverse osmosis, electro-dialysis), but there are a number of other options as well. A chemical (solute and extractant reaction) phenomenon known as reactive extraction has been developed to enhance solvent extraction separation. It is possible to separate carboxylic acids from dilute aqueous solutions using organophosphorus-based and long-chain aliphatic amine extractants. These extractants are usually diluted with a diluent before use. Solubility and volume are controlled by this agent. However, the diluent's chemical structure can also influence acid-amine complex formation in diverse ways. Reactive extraction for carboxylic acid recovery from fermentation broth and aqueous waste stream has been widely studied in relation to fermentation methods for carboxylic acids synthesis and recovery of carboxylic acids. These studies focus on various aspects such as solvent (extractant and diluent) selection, effects of temperature, pH, aqueous and organic phase compositions on extraction, in-situ product recovery, and chemical interactions involved in the complexation of acid with the extractant, kinetics of extraction, etc. When using extractants, the usage of active diluent (modifier) is restricted. Formic acid, acetic acid, propionic acid, and butyric acid can also be separated from the aqueous waste industrial stream using this reactive extraction data. Few carboxylic acids with specified extractants can be International Journal of Advances in Engineering and Management (IJAEM) Volume 4, Issue 1 Jan 2022, pp: 790-795 www.ijaem.net ISSN: 2395-5252 DOI: 10.35629/5252-0401790795 Impact Factor value 7.429 | ISO 9001: 2008 Certified Journal Page 791 quantified using the LSER model or a model built around the u&ET parameters for diluent effect. The possibility of estimating the equilibrium parameters using an evolutionary optimization method [differential evolution (DE)] is not investigated. Reactive extraction data can be generated with less toxic or non-toxic amine/diluent systems for the improvement of propionic and nicotinic acid synthesis by fermentation in a wide range of different ways [1-6]. II. HYDROGEN BONDING OF CARBOXYLIC ACID An organic functional group with a carboxylic acid moiety is considered very polar. Carbonyl (C-O) and hydroxyl (O-H) groups are strongly polarised, resulting in this polarity. A strong permanent dipole is formed when oxygen covalently bonds to carbon and hydrogen. Because of the neighbouring carbonyl moiety, the O-H group of carboxylic acids is much more polarised than the O-H group of alcohols. Additionally, the acidity of these compounds is due to these structural properties, as will be described later in this tutorial. The dipolar nature of acids Hydrogen bonding (H-bonding) interactions with similar molecules and water are made possible by the carboxylic acid dipoles, which operate as both a hydrogen bond giver and acceptor, as demonstrated below: Laterinolecular H-Bonding H-Bonding with Water Other organic compounds with OH and/or C-O dipoles have lower overall H-bonding interaction energy than carboxylic acids. Comparatively speaking, carboxylic acids have both more and stronger dipoles than the other organic compounds, allowing them to build stronger and more H-bonds with other compounds that can form H-bonds. Tutorials on the dipolarity of various additional chemical functional groups provide more information on this topic. International Journal of Advances in Engineering and Management (IJAEM) Volume 4, Issue 1 Jan 2022, pp: 790-795 www.ijaem.net ISSN: 2395-5252 DOI: 10.35629/5252-0401790795 Impact Factor value 7.429 | ISO 9001: 2008 Certified Journal Page 792 Boiling temperatures and water solubility of carboxylic acids are directly influenced by the energy associated with the dipoles present in these acids. The boiling points of carboxylic acids are high, as shown in the table below. Intermolecular H-bonding interactions between acid molecules are responsible for this, as illustrated in the earlier picture. Because of the strong intermolecular contact, acids have far higher boiling temperatures than non-polar alkane, alkene, alkyne, and aromatic hydrocarbons. These compounds have higher boiling temperatures than ketones, amines, amides, aldehydes, and isosteric compounds of the same hydrocarbon structure (similar number of carbon atoms). Carboxylic Acid Acidity: The acidic character of carboxylic acids is the most significant chemical feature for drug synthesis. For the longest time, the term "acid" has only been used to describe substances that can really transfer protons into water. Strong acids are mineral acids (HCI, HBr), H2SO4, and H3PO4 because they undergo complete dissociation and transfer a proton to water to generate the hydronium ion. III. USES OF ALDEHYDES AND KETONES Smallest ketone and simplest aldehyde: what are these things? Formaldehyde is the simplest aldehyde, whereas acetone is the smallest ketone. It is common to find aldehydes and ketones in conjunction with other functional groups. As a matter of fact, numerous industrial processes necessitate the usage of aldehydes and ketones. Plants, microbes, animals, and even people produce and consume aldehydes and ketones in large amounts. In plants and microorganisms such as carvone (spearmint and caraway), cinnamon bark, vanilla bean,helminthosporal (fungal toxin), Citra (lemongrass), and camphor (camphor trees), aldehydes and ketones are found. Muscone in musk Meer, progesterone, testosterone, and cortisone are examples of aldehydes and ketones found in animal and human hormones. Addiction to opiates such as heroin, opium, and morphine can be treated with the ketone "methadone," a well-known and widely used substance. In this section, we'll look at all the different ways aldehydes and ketones can be put to
TL;DR: In this paper , an enantioselective reaction of cyclic C-alkynyl imine precursor with thiols catalyzed by (R)-H8-TRIP has been described.
TL;DR: A significant correlation of serum SFRP4 level with Fasting blood glucose and HbA1c seen in the findings of this study puts on an extra contribution to consider this protein as a potential Biomarker for Type II Diabetes Mellitus.
Abstract: Background: Metabolic syndrome is a set of metabolic disorders and is considered as a predictor of cardiovascular risks. The expression of several specific genes and the related protein products also show their significance in pathophysiology of Metabolic Syndrome. Secreted Frizzled Related Protein 4 is a product of expression of SFRP4 genes. SFRP4 has been linked with inflammatory responses quite similar to the responses as in metabolic syndrome pathogenesis. Aim: The current study aimed to assess the circulatory level of Secreted Frizzled Related Protein 4 among metabolic syndrome individuals. Method: Estimation of SFRP4 was done by ELISA technique by using Human SFRP4 ELISA kit (Make- Bioassay Technology Laboratory, Cat no- E2327Hu, Zeijhang, China). Results: Mean concentration of serum SFRP4 in Metabolic Syndrome subjects (2.06 ± 1.39 ng/ml) was significantly higher than the mean concentration of healthy controls (1.28 ± 1.29 ng/ml) (p< 0.05 *). Conclusion: A significant correlation of serum SFRP4 level with Fasting blood glucose and HbA1c seen in the findings of this study puts on an extra contribution to consider this protein as a potential Biomarker for Type II Diabetes Mellitus.