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1.
Inorg Chem ; 63(1): 494-507, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38145464

RESUMEN

Organic polymers have attracted considerable interest in designing a multifunctional electrocatalyst. However, the inferior electro-conductivity of such metal-free polymers is often regarded as a shortcoming. Herein, a nitrogen- and phosphorus-rich polymer with phosphamide functionality (PAP) in the repeating unit has been synthesized from diaminopyridine (DAP) and phenylphosphonic dichloride (PPDC) precursors. The presence of phosphamide oxygen and pyridine nitrogen in the repeating unit of PAP leads to the coordination of the CuII ion and the incorporation of 3.29 wt % in the polymer matrix (Cu30@PAP) when copper salt is used to impregnate the polymer. Combined with a spectroscopic, microscopic, and DFT study, the coordination and geometry of copper in the PAP matrix has been established to be a distorted square planar CuII in a N2O2 ligand environment where phosphamide oxygen and pyridine nitrogen of the PAP coordinate to the metal center. The copper incorporation in the PAP modulates its electrocatalytic activity. On the glassy carbon electrode, PAP shows inferior activity toward the hydrogen evolution reaction (HER) in 0.5 M H2SO4 while 3 wt % copper incorporation (Cu30@PAP) significantly improves the HER performance with an overpotential of 114 mV at 10 mA cm-2. The notable electrochemical activity with Cu30@PAP occurs due to the impregnation of Cu(II) in PAP, improved electro-kinetics, and better charge transfer resistance (Rct). When changing the electrolyte from H2SO4 to CO2-saturated bicarbonate solution at nearly neutral pH, PAP shows HER as the dominant pathway along with the partial reduction of CO2 to formate. Moreover, the use of Cu30@PAP as an electrolcatalyst could not alter the predominant HER path, and only 20% Faradaic efficiency for the CO2 reduced products has been achieved. Post-chronoamperometric characterization of the recovered catalyst suggests an unaltered valence state of the copper ion and the intact chemical structure of PAP. DFT studies unraveled that the copper sites of Cu30@PAP promote water adsorption while phosphamide-NH of the PAP can weakly hold the CO2 adduct via a hydrogen bonding interaction. A detailed calculation has pointed out that the tetra-coordinated copper centers present in the PAP frame are the reactive sites and that the formation of the [CuI-H] intermediate is the rate-limiting step for both HER and its competitive side reaction, i.e., CO2 reduction to formate or CO formation. The high proton concentration in the electrolyte of pH < 7 leads to HER as the predominant pathway. This combined experimental and theoretical study has highlighted the crucial role of copper sites in electrocatalysis, emphasizing the plausible reason for electrocatalytic selectivity.

2.
Langmuir ; 39(33): 11694-11707, 2023 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-37552772

RESUMEN

Gangliosides, forming a class of lipids complemented by sugar chains, influence the lateral distribution of membrane proteins or membrane-binding proteins, act as receptors for viruses and bacterial toxins, and mediate several types of cellular signaling. Gangliosides incorporated into supported lipid bilayers (SLBs) have been widely applied as a model system to examine these biological processes. In this work, we explored how ganglioside composition affects the kinetics of SLB formation using the vesicle rupturing method on a solid surface. We imaged the attachment of vesicles and the subsequent SLB formation using the time-lapse total internal reflection fluorescence microscopy technique. In the early phase, the ganglioside type and concentration influence the adsorption kinetics of vesicles and their residence/lifetime on the surface before rupturing. Our data confirm that a simultaneous rupturing of neighboring surface-adsorbed vesicles forms microscopic lipid patches on the surface and it is triggered by a critical coverage of the vesicles independent of their composition. In the SLB growth phase, lipid patches merge, forming a continuous SLB. The propagation of patch edges catalyzes the process and depends on the ganglioside type. Our pH-dependent experiments confirm that the polar/charged head groups of the gangliosides have a critical role in these steps and phases of SLB formation kinetics.


Asunto(s)
Toxinas Bacterianas , Membrana Dobles de Lípidos , Membrana Dobles de Lípidos/química , Cinética , Gangliósidos/química , Microscopía Fluorescente
3.
Molecules ; 27(10)2022 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-35630831

RESUMEN

In the present work, an effort has been made to utilize Phyllanthus emblica (PE) fruit stone as a potential biomaterial for the sustainable remediation of noxious heavy metals viz. Pb(II) and Cd(II) from the aqueous solution using adsorption methodology. Further, to elucidate the adsorption potential of Phyllanthus emblica fruit stone (PEFS), effective parameters, such as contact time, initial metal concentration, temperature, etc., were investigated and optimized using a simple batch adsorption method. It was observed that 80% removal for both the heavy metal ions was carried out within 60 min of contact time at an optimized pH 6. Moreover, the thermodynamic parameters results indicated that the adsorption process in the present study was endothermic, spontaneous, and feasible in nature. The positive value of entropy further reflects the high adsorbent-adsorbate interaction. Thus, based on the findings obtained, it can be concluded that the biosorbent may be considered a potential material for the remediation of these noxious impurities and can further be applied or extrapolated to other impurities.


Asunto(s)
Metales Pesados , Phyllanthus emblica , Contaminantes Químicos del Agua , Materiales Biocompatibles , Cadmio/análisis , Frutas/química , Concentración de Iones de Hidrógeno , Iones , Agua , Contaminantes Químicos del Agua/análisis
4.
Health Promot Int ; 36(1): 89-100, 2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-32337575

RESUMEN

The prevalence of physical inactivity in India is estimated to be at 34%, the highest among South Asian nations. Interventions, such as outdoor gymnasiums/gyms, aiming to promote physical activity, are becoming popular worldwide, including in India. This paper presents the first empirical evidence on outdoor gyms in India from a qualitative perspective. Semi-structured, in-depth interviews of 56 outdoor gym stakeholders-40 users, 10 non-users, 4 healthcare providers and 2 outdoor gym implementing municipality authorities were conducted in the National Capital Region of India. The interviews were transcribed and analyzed through the Framework Method. The qualitative findings present the perceived benefits, barriers/challenges to using and provide insights for further improving and scaling up outdoor gyms in India. Health enhancement in the form of improved general fitness, body weight control and diversification of physical exercise routines, social connectivity, easy accessibility, affordability, green outdoor surroundings, and a place of intrigue and attraction in respective parks were the major reported benefits of outdoor gyms. Low gym equipment to user ratio was one of the major challenges to gym use across the user group. Healthcare providers and non-users were majorly concerned about the potentially incorrect and unsupervised use of outdoor gym equipment. Major suggestions for improvement were increasing the number of equipment installed, regular equipment maintenance, and the presence of an on-site physical exercise trainer. Outdoor gymnasiums present as a viable option for promoting physical activity and should be scaled up systematically to improve the health of the populations across India and other similar nations.


Asunto(s)
Centros de Acondicionamiento , Ejercicio Físico , Promoción de la Salud , Humanos , India , Percepción
5.
Analyst ; 145(11): 3948-3957, 2020 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-32314981

RESUMEN

Carbon Quantum Dots (CQDs) have been extensively employed in various fields of science such as sensing, catalysis, and drug delivery. In this work, ionic liquid coated CQDs (IL@CQDs) have been used as catalysts for the rearrangement of a 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) amide coupling intermediate. The rearranged product was confirmed by single crystal structure analysis and it was processed into organic nanoparticles (ONPs). An optical detection method was used to scrutinize the anion sensing properties. The ONPs were found to be sensitive and selective for the recognition of highly toxic cyanide ions through enhancement in the fluorescence intensity. The cyanide ion co-ordinates with the -NH groups of the product and restricts the rotation of molecules around the single bond. The ONPs coated over silica-beads were also showing CN- recognition in the solid state. The detection limit for CN- sensing was found to be 3.8 nM, and real sample analysis depicts more than 90% accuracy in detection.

6.
Langmuir ; 35(14): 4893-4901, 2019 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-30879297

RESUMEN

Nitrogen-enriched nanoporous polytriazines (NENPs) have been synthesized by ultrafast microwave-assisted condensation of melamine and cyanuric chloride. The experimental conditions have been optimized to tune the textural properties by synthesizing materials at different times, temperatures, microwave powers, and solvent contents. The maximum specific surface area (SABET) of 840 m2 g-1 was estimated in the sample (NENP-1) synthesized at 140 °C with a microwave power of 400 W and reaction time of 30 min. One of the major objectives of achieving a large nitrogen content as high as 52 wt % in the framework was realized. As predicted, the nitrogen amelioration has benefitted the application by capturing a very good amount of CO2 of 22.9 wt % at 273 K and 1 bar. Moreover, the CO2 storage capacity per unit specific surface area (per m2 g-1) is highest among the reported nanoporous organic frameworks. The interaction of the CO2 molecules with the polytriazine framework was theoretically investigated by using density functional theory. The experimental CO2 capture capacity was validated from the outcome of the theoretical calculations. The superior CO2 capture capability along with the theoretical investigation not only makes the nanoporous NENPs superior adsorbents for the energy and environmental applications but also provides a significant insight into the fundamental understanding of the interaction of CO2 molecules with the amine functionalities of the nanoporous frameworks.

7.
Indian J Public Health ; 60(4): 268-272, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27976647

RESUMEN

BACKGROUND: Rabies is a preventable neglected public health problem and associated with multiple cultural, religious, and social practices, myths in our country. There is a lack of organized surveillance system to measure the incidence of animal bite and human rabies as well as to evaluate cost-saving of different routes, regimen, and types of antirabies vaccines (ARV)/immunoglobulin available in India. OBJECTIVES: The objective of this study is to know dropout rate in intradermal (i.d.) ARV regimen among animal bite and to analyze the utilized volume of ARV by a different route of vaccine administration. METHODS: A total of 250 animal bite victims were followed up at ARV Clinic (ARVC). Volume utilization of i.d. route over intramuscular (i.m.) route was analyzed among the patients who attended ARVC during the past 2 years. Total dropout and delayed compliance rates of ARV regimen among different group were compared by Chi-square test. RESULTS: The i.d. route was about five times more volume and cost-saving than i.m. route. The majority of victims belonged to 15-30 years (27.60%) and children <15 years (26.40%) and had wound at their lower limbs (85%) mainly bitten by dogs (98%). Thirty-four percent total dropout and 31.5% delayed compliance observed particularly during the last dose of i.d. regimen. There was no significant difference in dropout rates among different demographic groups. Half of the victims practiced wound toilet on the same day of bite. Only 68% received the first dose of ARV within 24 h of the exposure. CONCLUSION: Children and young adults are at higher risk of having dog bite. I.d. ARV regimen is more volume and cost-saving than i.m. one and proper counseling and follow-up should be arranged to complete the vaccination schedule.


Asunto(s)
Mordeduras y Picaduras , Vacunas Antirrábicas , Rabia , Animales , Niño , Perros , Humanos , India , Cooperación del Paciente , Pacientes Desistentes del Tratamiento , Rabia/prevención & control , Vacunas Antirrábicas/uso terapéutico , Vacunación
8.
Food Technol Biotechnol ; 53(1): 11-17, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27904327

RESUMEN

Haloarchaea are found at very high concentrations in salt-conditioned environments, hence produce enzymes which are able to catalyze reactions under harsh conditions, typical of many industrial processes. In the present study, culture conditions for extracellular amylase production from Haloarchaea isolated from a solar saltern were optimized and the purified enzyme was characterized. Haloferax sp. HA10 showed maximum amylase production at 3 M NaCl, 37 °C, pH=7 and 1% starch content. Purified α-amylase was a calcium-dependent enzyme with an estimated molecular mass of about 66 kDa and many industrially useful properties. It was found to be stable in a broad range of pH (from 5 to 9) and NaCl concentrations (from 0.5 to 3.0 M), retaining 48% activity even at 4 M. The optimal temperature for Haloferax sp. HA10 amylase activity was 55 °C (99% activity), and 57% activity was retained at 80 °C, which dropped to 44% with the increase of temperature to 90 or 100 °C. It was able to sustain various surfactants and detergents. To the best of our knowledge the detergent-stable α-amylases from halophilic archaeon have not been reported yet.

9.
J Phys Chem B ; 128(3): 768-780, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38228291

RESUMEN

The world has witnessed multiple pandemics and endemics caused by enveloped viruses in the past century. To name a few, the ongoing COVID-19 pandemic and other pandemics/endemics caused by coronaviruses, influenza viruses, HIV-1, etc. The external and topical applications of surfactants have been effective in limiting the spread of viruses. While it is well-known that surfactants inactivate virus particles (virions), the mechanism of action of surfactants against enveloped virions has not yet been established. In this work, we have evaluated the surfactant-induced disruption mechanism of a cocktail of enveloped viruses containing particles of mumps, measles, and rubella viruses. We applied the total internal reflection fluorescence microscopy technique to trace the temporal changes in the fluorescence signal from single virions upon the addition of a surfactant solution. We report that surfactants solubilize either the viral lipid membrane, proteins, or both. Ionic surfactants, depending on their charge and interaction type with the viral lipids and proteins, can cause bursting or perforation of the viral envelope, whereas a nonionic surfactant can cause either symmetric expansion or perforation of the viral envelope depending on the surfactant concentration.


Asunto(s)
Orthomyxoviridae , Virus , Humanos , Pandemias , Virión , Tensoactivos/farmacología
10.
ACS Omega ; 9(4): 4166-4185, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38313515

RESUMEN

Carbon dots (CDs) have drawn attention due to their enticing physical, chemical, and surface properties. Besides, good conductivity, low toxicity, environmental friendliness, simple synthetic routes, and comparable optical properties are advantageous features of CDs. Further, recently, CDs have been explored for biological systems, including plants. Among biological systems, only plants form the basis for sustainability and life on Earth. In this Review, we reviewed suitable properties and applications of CDs, such as promoting the growth of agricultural plants, disease resistance, stress tolerance, and target transportation. Summing up the available studies, we believe that the applications of CDs are yet to be explored significantly for innovation and technology-based agriculture.

11.
Pancreas ; 53(4): e330-e337, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38345925

RESUMEN

BACKGROUND: Pseudoaneurysm usually occurs after vascular injuries or erosions such as in trauma or inflammation like pancreatitis and is associated with high morbidity and mortality. AIM: The aim of study is to assess efficacy and safety of EUS-guided thrombin injection in pseudoaneurysm. MATERIALS AND METHODS: Prospective data collection was done at SMS Hospital, Jaipur, from January 2015 to March 2023. All patients with pseudoaneurysm were consecutively enrolled. RESULTS: Twenty patients (M/F, 18:2) with median age of 41 years (25-58 years), were studied. Underlying etiology of pseudoaneurysm was chronic pancreatitis in 75% of the patients, blunt trauma abdomen in 15% of the patients, recurrent acute pancreatitis in 5%, and idiopathic in 5% of the patients. At the time of admission, mean hemoglobin was 6.7 g/dL (3.4-8.2), with median blood transfusion requirement was 2 units (0-6 units). Hemoglobin values after 4-6 weeks showed a significant improvement ( t = 9.21, P < 0.05).Mean dose of human thrombin required for complete obliteration of pseudoaneurysm was 520 ± 188.6 IU per patient (300-800 IU). Amount of thrombin (IU) dose needed to achieve complete obliteration correlated well significantly with the dimension of pseudoaneurysm, P value less than 0.05 ( R = 0.80). Median follow-up duration in this study was 44 months (3-84 months), which was the longest follow-up period by far. CONCLUSIONS: Endoscopic ultrasound-guided thrombin injection in visceral artery pseudoaneurysm is a safe and effective alternative for patients not amenable for digital subtraction angiography-guided angioembolization.


Asunto(s)
Aneurisma Falso , Pancreatitis , Humanos , Adulto , Trombina , Aneurisma Falso/diagnóstico por imagen , Aneurisma Falso/tratamiento farmacológico , Enfermedad Aguda , Pancreatitis/complicaciones , Ultrasonografía Intervencional/efectos adversos , Ultrasonografía Intervencional/métodos , Abdomen , Hemoglobinas , Arterias
12.
Cureus ; 16(3): e56828, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38654785

RESUMEN

Metformin is the most prescribed and recommended drug for type 2 diabetes mellitus because of its better tolerability, pleiotropic benefits, and cost-effectiveness. Metformin inhibits hepatic glucose production and increases muscle glucose uptake. Metformin is also associated with gastrointestinal side effects like abdominal bloating, flatulence, diarrhea, nausea, and vomiting. Metformin-related gastrointestinal side effects are mainly due to alteration in gut microbiota, raised intestinal glucose, and increased ileal bile salt reabsorption. We report a case of a 62-year-old diabetic patient who presented with chronic diarrhea with a weight loss of 6 kg from the last six years after initiation of metformin. He underwent multiple investigations and was finally misdiagnosed with irritable bowel syndrome for years. After discontinuation of metformin, there was a significant improvement in gastrointestinal symptoms. Our case highlights the importance of metformin-induced chronic diarrhea if no other causes for the diarrhea are obvious in patients with type 2 diabetes taking metformin. Consideration of this potential side effect of metformin must be valuable to avoid unwarranted investigations, additional drug therapy, and annoyance of the patients.

13.
J Enzyme Inhib Med Chem ; 28(1): 1-10, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21981002

RESUMEN

In the present investigation, synthesis and anti-bacterial, analgesic and anthelmintic evaluation of a novel series of fluoroquinolone derivatives clubbed with benzothiazole moeity has been described. The synthesized compounds were characterised by spectral analysis (IR and (1)H NMR). Preliminary results indicated that the most of the synthesized compounds demonstrated good activities against gram negative and gram positive bacterial strains. Compounds 5a, 5b, 5f and 5k demonstrated potent anti-bacterial activities. Compound 5a exhibited most potent anti-bacterial activity with MIC values of 04, 03, 08 and 15 µg/ mL against B. subtilis, S. aureus, E. coli and P. aeruginosa. Analogs 5a, 5c, 5g and 5h showed promising anthelmintic activity against Eisemia foetida in a low concentration as compared to standard drug piperazine citrate with mean paralysis time ranging 22.60 ± 2.46 to 31.60 ± 3.07 min. All synthesized compounds depicted good in vivo analgesic activity with compound 5a exhibiting the most potent activity of 55.19% inhibition of writhing in comparison to the standard drug.


Asunto(s)
Analgésicos/farmacología , Antihelmínticos/farmacología , Antibacterianos/síntesis química , Antibacterianos/farmacología , Benzotiazoles/química , Fluoroquinolonas/síntesis química , Analgésicos/síntesis química , Analgésicos/química , Animales , Antihelmínticos/síntesis química , Antihelmínticos/química , Antibacterianos/química , Bacillus subtilis/efectos de los fármacos , Técnicas de Química Sintética , Relación Dosis-Respuesta a Droga , Escherichia coli/efectos de los fármacos , Femenino , Fluoroquinolonas/química , Fluoroquinolonas/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Masculino , Ratones , Pruebas de Sensibilidad Microbiana , Oligoquetos/efectos de los fármacos , Piperazinas/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Espectrofotometría Infrarroja , Staphylococcus aureus/efectos de los fármacos
14.
Lancet Reg Health Southeast Asia ; 14: 100208, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37492420

RESUMEN

Background: The ever-growing trend of abdominal obesity worldwide has garnered global attention over the past three decades. In India, BMI has conventionally been used to measure obesity. National Family Health Survey (NFHS) is the largest demographic and health survey (DHS) in India. For the first time, the NFHS conducted the fifth round in 2019-21 which assessed abdominal obesity through waist circumference. The objective of the current study was to determine the prevalence of abdominal obesity and explore the associated socioeconomic factors. Methods: The prevalence of abdominal obesity in India was determined using the NFHS-5 dataset, where waist circumference was used as a measure. Multivariable binary logistic regression was then employed to examine the association of different socioeconomic factors with abdominal obesity. Findings: The prevalence of abdominal obesity in the country was found to be 40% in women and 12% in men. The findings show that 5-6 out of 10 women between the ages of 30-49 are abdominally obese. The association of abdominal obesity in women is stronger with older age groups, urban residents, wealthier sections, and non-vegetarians. For those practising the Sikh religion, the prevalence is higher in both men and women. Abdominal obesity is also on the rise in rural areas and is penetrating lower and middle socioeconomic sections of society. Interpretation: The findings of the current study highlight the need for the government and other stakeholders to proactively design targeted interventions for abdominal obesity, especially for women in their thirties and forties in India. Further research is recommended to understand the driving factors of abdominal obesity, their inter-operability, and the disease risk associated with this type of obesity. Funding: None.

15.
Biochim Biophys Acta Gen Subj ; 1867(4): 130317, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36731729

RESUMEN

BACKGROUND AND OBJECTIVES: NSCLC (Non-Small Cell Lung Cancer) clutches highest mortality rate in man and women globally. The present study was conducted to target MUC-1 peptide (M-1) into antigen presenting cells by cargo the peptide into hyaluronic acid decorated polyethylene glycol linked poly (D, l-lactide-co-glycolide) nanoparticles (M-1-PL-co-GA-PEG-sHA-NPs) for generating mucosal immunity through inhalation (i.h.) route. METHODOLOGY AND RESULTS: The mean particle size and surface charge of M-1-PL-co-GA-PEG-sHA-NPs was measured to be 136.2 ± 18.38-nm and - 28.34 ± 6.77-mV, respectively, prepared by non-aggregated emulsion-diffusion evaporation method. The 28.42% percentage release of M-1 peptide from M-1-PL-co-GA-PEG-NPs was observed to be at 2 h and 95.29% at 8 h while the percentage release of M-1 peptide from M-1-PL-co-GA-PEG-sHA-NPs was observed to be 26.02% at 4 h and 97.95% at 24 h that proved the prolonged release of antigen. M-1-PL-co-GA-PEG-sHA-NPs demonstrated higher (P < 0.05) cellular uptake of 86.2% in RAW 264.7 cells in comparison to 27.6% of M-1-PL-co-GA-PEG-NPs. In addition, M-1-PL-co-GA-PEG-sHA-NPs induced remarkably (P < 0.05) elevated release of 80.6-pg/ml of TNF-α in comparison to 5-pg/ml by culture medium and 57.9-pg/ml of TNF-α by M-1-PL-co-GA-PEG-NPs. Similarly, M-1-PL-co-GA-PEG-sHA-NPs persuade remarkably (P < 0.05) elevated release of 225-pg/ml of IL-1ß in comparison to 47-pg/ml by culture medium and 161.9-pg/ml of IL-1ß by M-1-PL-co-GA-PEG-NPs. M-1-PL-co-GA-PEG-sHA-NPs might have been endocytosed through receptor mediated pathway owing to presence of sHA. Mice immunized through i.h. route with M-1-PL-co-GA-PEG-sHA-NPs induced strong (P < 0.05) IgA antibody titre as compared to M-1-PL-co-GA-PEG-NPs and M-1 peptide in dose-dosage regimen. CONCLUSION: M-1-PL-co-GA-PEG-sHA-NPs nanovaccine warrants further analysis in xenograft model of NSCLC to showcase its antitumor capability.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Nanopartículas , Animales , Ratones , Glicosaminoglicanos , Inmunidad Mucosa , Ratones Endogámicos BALB C , Polietilenglicoles , Poliglactina 910 , Factor de Necrosis Tumoral alfa
16.
ACS Infect Dis ; 9(7): 1346-1361, 2023 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-37145972

RESUMEN

Multiple recent reports indicate that the S protein of SARS-CoV-2 specifically interacts with membrane receptors and attachment factors other than ACE2. They likely have an active role in cellular attachment and entry of the virus. In this article, we examined the binding of SARS-CoV-2 particles to gangliosides embedded in supported lipid bilayers (SLBs), mimicking the cell membrane-like environment. We show that the virus specifically binds to sialylated (sialic acid (SIA)) gangliosides, i.e., GD1a, GM3, and GM1, as determined from the acquired single-particle fluorescence images using a time-lapse total internal reflection fluorescence (TIRF) microscope. The data of virus binding events, the apparent binding rate constant, and the maximum virus coverage on the ganglioside-rich SLBs show that the virus particles have a higher binding affinity toward the GD1a and GM3 compared to the GM1 ganglioside. Enzymatic hydrolysis of the SIA-Gal bond of the gangliosides confirms that the SIA sugar unit of GD1a and GM3 is essential for virus attachment to the SLBs and even the cell surface sialic acid is critical for the cellular attachment of the virus. The structural difference between GM3/GD1a and GM1 is the presence of SIA at the main or branched chain. We conclude that the number of SIA per ganglioside can weakly influence the initial binding rate of SARS-CoV-2 particles, whereas the terminal or more exposed SIA is critical for the virus binding to the gangliosides in SLBs.


Asunto(s)
COVID-19 , Gangliósidos , Humanos , Gangliósidos/química , Ácido N-Acetilneuramínico/metabolismo , Gangliósido G(M1)/química , Gangliósido G(M1)/metabolismo , SARS-CoV-2/metabolismo
17.
J Phys Condens Matter ; 36(10)2023 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-37988750

RESUMEN

The change induced in the physicochemical properties of polymer while hosting ions provides a platform for studying its potential applications in electrochemical devices, water treatment plants, and materials engineering science. The ability to host ions is limited in very few polymers, which lack a detailed molecular-level understanding for showcasing the polymer-ion linkage behavior at the interfacial region. In the present manuscript, we have employed sum frequency generation (SFG) vibrational spectroscopy to investigate the interfacial structure of a new class phosphazene-based methoxyethoxyethoxyphosphazene (MEEP) polymer in the presence of lithium chloride salt at the air-aqueous interface. The interfacial aspects of the molecular system collected through SFG spectral signatures reveal enhanced water ordering and relative hydrogen bonding strength at the air-aqueous interface. The careful observation of the study finds a synchronous contribution of van der Waals and electrostatic forces in facilitating changes in the interfacial water structure that are susceptible to MEEP concentration in the presence of ions. The observation indicates that dilute MEEP concentrations support the role of electrostatic interaction, leading to an ordered water structure in proximity to diffused ions at the interfacial region. Conversely, higher MEEP concentrations promote the dominance of van der Waals interactions at the air-aqueous interface. Our study highlights the establishment of polymer electrolyte (PE) characteristics mediated by intermolecular interactions, as observed through the spectral signatures witnessed at the air-aqueous interface. The investigation illustrates the polymer-ion linkage adsorption effects at the interfacial region, which explains the macroscopic changes observed from the cyclic voltammetry studies. The fundamental findings from our studies can be helpful in the design and fine-tuning of better PE systems that can offer improved hydrophobic membranes and interface stability for use in electrochemical-based power sources.

18.
Cell Biochem Biophys ; 80(1): 229-243, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34709575

RESUMEN

Acne is one of the most common dermatological skin problem caused due to inflammation of the skin, leading to unfavorable growth of Propionibacterium acnes. It is a slow growing anaerobic, gram-positive bacterium that releases chemotactic factors and leads to the complex pathogenicity of acne. There are several acne treatments/therapies available, but topical therapy is usually the first choice for mild to moderate acne, and as the severity of the acne increases, the treatment modalities fail. There are many acne treatment options available, but topical therapy is best suited for mild - to - moderate skin problems, and then as the seriousness of the acne grows, the therapeutic approaches fall short. Biosurfactants are surfactants produced from plants or animals; Saponins are plant derived non-ionic biosurfactants which have steroidal and triterpenic glycosides distributed largely in plant kingdom. Numerous studies conducted by scientists have established the antimicrobial activity of and are considered more advantageous over synthetic precursors as they are eco-friendly, cheap and non-toxic. The present study was undertaken to investigate the antibacterial activity of saponins (bio-surfactants) characterized using mass spectroscopy against acne-causing bacteria. The discharge of cellular components including protein and UV-sensitive materials in the cell-free supernatant was provoked by saponin, confirming the cellular and membrane disturbances.. Furthermore, various morphological changes on the bacterial cell surface structure by Transmission electron microscopy and scanning electron microscopy revealed the disruption of the cell integrity leading to death. Results confirmed presence of non-ionic surfactants primarily affecting the disruption and destruction to the bacteria which indicates that saponins are efficient components with great potential applications in various pharmaceutical preparations. Effects of Prednisolone derivative and Panaxydol: Biosurfactants on cell wall integrity of Acne-Causing Resistant Bacteria.


Asunto(s)
Acné Vulgar , Prednisolona , Acné Vulgar/tratamiento farmacológico , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pared Celular , Diinos , Alcoholes Grasos , Prednisolona/farmacología , Prednisolona/uso terapéutico , Propionibacterium acnes
19.
Environ Sci Pollut Res Int ; 29(31): 47448-47461, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35182339

RESUMEN

Boron-doped SnO2 (B:SnO2) has been synthesized via a facile wet chemical method to deal with increasing energy demand and environment-related issues. Powder XRD confirmed the rutile phase of the synthesized B:SnO2 nanoparticles. Energy dispersive X-ray analysis and elemental mapping confirmed 1% B doping into SnO2 lattice. A red shift was observed during the analysis of Raman and FTIR spectral data. The bands in FTIR and Raman spectra confirmed the in-plane and bridging oxygen vacancies in SnO2 lattice introduced due to B doping. These nanoparticles showed proficiency in photocatalytic hydrogen generation and degradation of crystal violet (CV) and rhodamine B (RhB) dyes. The degradation of CV and RhB dyes in the presence of B:SnO2 NPs and ethane-1,2-diaminetetracetic acid (EDTA) was found to be 83 and ~ 100%, respectively. To escalate the efficiency of dye degradation, the experiment was performed with different sacrificial agents (EDTA, methanol, and triethanolamine). The maximum hydrogen production rate (63.6184 µmol g-1 h-1) was observed for B:SnO2 along with Pd as co-catalyst, and methanol and EDTA solution as sacrificial agents.

20.
J Obstet Gynaecol India ; 70(5): 355-359, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33041552

RESUMEN

INTRODUCTION: WHO states that obstetric hemorrhage, hypertensive disorders of pregnancy and sepsis account for approximately 50% of maternal deaths worldwide. All these conditions are associated with changes in vital signs including blood pressure (BP) and heart rate (HR). Shock index (SI) is the ratio of HR to systolic BP. AIMS AND OBJECTIVES: To evaluate role of shock index as an early indicator of adverse maternal outcomes and to determine the threshold points of SI for five adverse maternal outcomes. METHODOLOGY: This was a prospective observational study on 1004 consecutively enrolled subjects presenting in labor. Vital signs and Shock Index were recorded. SI thresholds were analyzed with respect to obstetric complications and adverse outcomes. Parametric tests such as Chi-square, comparison of proportions, comparison of mean and ROC curve analysis were applied on the data. RESULTS: The mean SI value in the vaginal delivery group was 1.02 ± 0.26 and it was 0.95 ± 0.033 in the caesarean delivery group. The values of SI ((Mean and SD) for ICU admission were (1.23 (± 0.35)), for (MODS) it was (1.47 (± 0.84)), for blood transfusion > 4 units it was (1.15 (± 0.41)), for surgical intervention it was (1.58 (± 0.51)) and for maternal death (1.39 (± 0.85)). SI ≥ 1.4, had sensitivity 26.82% (21.09-33.19); specificity 100%(99.53-100), PPV was 100% and NPV was 82.96%(81.8-84.06)with an AUC of 0.8 (0.78-0.83) on ROC analysis. In subjects with PIH/eclampsia, SI was lower and in patients with severe anemia, SI was higher. CONCLUSION: SI performed well as a screening tool in the prediction of adverse maternal outcomes. SI ≥ 0.9 was significantly associated with maternal adverse outcomes: ICU admission, MODS, surgical intervention, blood transfusion and death. The study proposes an SI cut-off of 0.9 for referral and a cut-off of 1.1 for intervention in a tertiary care hospital. Patients with PIH/eclampsia tend to have lower mean SI values as compared to the rest of the study population, suggesting that SI may not be a reliable indicator in patients with PIH/eclampsia.

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