Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
Add more filters











Publication year range
1.
Cureus ; 16(8): e66123, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39229399

ABSTRACT

Meconium-stained amniotic fluid (MSAF) presents a complex medical scenario with significant implications for maternal and neonatal health. This case report explores the intricacies surrounding MSAF, focusing on its diagnosis, treatment, and the associated meconium aspiration syndrome (MAS). The report emphasizes the critical role of antibiotic prophylaxis in lower segment cesarean sections (LSCS) in balancing infection prevention in the mother with neonatal considerations. Additionally, it highlights personalized pain management and post-operative care regimens, contributing to a comprehensive strategy for maternal and neonatal well-being. A 27-year-old primigravida (primi) underwent a cesarean section due to the presence of meconium in the amniotic fluid, indicating fetal distress. The report meticulously documents vital signs, laboratory findings, and the timeline of events. The case report underscores the importance of diagnosing and treating MAS, offering valuable insights into management strategies and their impact on maternal and neonatal health. This case report emphasizes the critical role of antibiotic prophylaxis in LSCS to prevent maternal infection while considering neonatal well-being. The personalized pain management approach and post-operative care regimens contribute significantly to a comprehensive strategy for maternal and neonatal well-being. The findings provide valuable insights into diagnosing and treating MAS, highlighting the importance of timely intervention in similar clinical scenarios.

2.
Toxicol Rep ; 13: 101715, 2024 Dec.
Article in English | MEDLINE | ID: mdl-39280991

ABSTRACT

Alzheimer's disease (AD) is a major cause of disability and one of the top causes of mortality globally. AD remains a major public health challenge due to its prevalence, impact on patients and caregivers, and the current lack of a cure. In recent years, polyphenols have garnered attention for their potential therapeutic effects on AD. The objective of the study was to establish network pharmacology between selected polyphenols of plant origin and AD. Insilico tools such as SwissADME, ProTox3.0, pkCSM, Swiss Target Prediction, DisGeNET, InterActiVenn, DAVID database, STRING database, Cytoscape/CytoHubba were employed to establish the multi-target potential of the polyphenolic compounds. The present study revealed that out of 17 polyphenols, 10 ligands were found to possess a drug-likeness nature along with desirable pharmacokinetic parameters and a lesser toxicity profile. Also, the results highlighted the possible interactions between the polyphenols and the disease targets involved in AD. Further, this study has shed light on the mTOR pathway and its impact on AD through the autophagic mechanism. Overall, this study indicated that polyphenols could be a better therapeutic option for treating AD. Hence, the consumption of polyphenolic cocktails as a part of the diet could produce more effective outcomes against the disease. Additional studies are warranted in the future to explore additional pathways and genes to provide a comprehensive understanding regarding the usage of the shortlisted polyphenols and their derivatives for the prevention and treatment of AD.

3.
World J Gastroenterol ; 30(27): 3356-3360, 2024 Jul 21.
Article in English | MEDLINE | ID: mdl-39086745

ABSTRACT

The concept of inflammatory bowel disease (IBD), which encompasses Crohn's disease and ulcerative colitis, represents a complex and growing global health concern resulting from a multifactorial etiology. Both dysfunctional autophagy and dysbiosis contribute to IBD, with their combined effects exacerbating the related inflammatory condition. As a result, the existing interconnection between gut microbiota, autophagy, and the host's immune system is a decisive factor in the occurrence of IBD. The factors that influence the gut microbiota and their impact are another important point in this regard. Based on this initial perspective, this manuscript briefly highlighted the intricate interplay between the gut microbiota, autophagy, and IBD pathogenesis. In addition, it also addressed the potential targeting of the microbiota and modulating autophagic pathways for IBD therapy and proposed suggestions for future research within a more specific and expanded context. Further studies are warranted to explore restoring microbial balance and regulating autophagy mechanisms, which may offer new therapeutic avenues for IBD management and to delve into personalized treatment to alleviate the related burden.


Subject(s)
Autophagy , Dysbiosis , Gastrointestinal Microbiome , Humans , Gastrointestinal Microbiome/immunology , Dysbiosis/immunology , Crohn Disease/microbiology , Crohn Disease/immunology , Colitis, Ulcerative/microbiology , Colitis, Ulcerative/immunology , Animals , Inflammatory Bowel Diseases/microbiology , Inflammatory Bowel Diseases/immunology
4.
Chem Biodivers ; : e202401430, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-39031897

ABSTRACT

A series of resveratrol surrogate molecules were designed, synthesized and biologically evaluated for inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) along with anti-oxidant activity as potential novel multifunctional agents against Alzheimer's disease (AD). Six novel compounds were synthesized by reacting (E)-4-(3,5-Dimethoxystyryl) aniline with benzaldehyde and some selected derivatives of benzaldehyde in the presence of ethanol and a few drops of glacial acetic acid which followed the general scheme involved in the formation of Schiff bases. The spectral analysis data including FT-IR, 1H-NMR, 13C-NMR, and Mass spectroscopy results were found to be in good agreement with the newly synthesized compounds (Resveratrol Surrogate Molecules 1-6). The synthesized compounds were evaluated for their dual cholinesterase inhibitory activities, cytotoxic effect, and anti-oxidant potential. The results showed that compound RSM5 showed potent inhibitory activity against AChE and BChE. In, addition the cytotoxicity of the compound RSM5 is less and found to be within the desirable limit indicating the potential safety of RSM5. Also, it possesses substantial anti-oxidant activity which qualifies RSM5 as an anti-AD agent. Taken together, these findings demonstrate that the molecule RSM5 had the most multifunctional properties and could be a promising lead molecule for the future development of drugs for Alzheimer's treatments.

7.
Front Pharmacol ; 14: 1212376, 2023.
Article in English | MEDLINE | ID: mdl-37781695

ABSTRACT

Background: Excitotoxicity is a condition in which neurons are damaged/injured by the over-activation of glutamate receptors. Excitotoxins play a crucial part in the progression of several neurological diseases. Marsilea quadrifolia Linn (M. quadrifolia) is a very popular aquatic medicinal plant that has been utilised for a variety of therapeutic benefits since ancient times. Its chemical composition is diverse and includes phenolic compounds, tannins, saponins, flavonoids, steroids, terpenoids, alkaloids, carbohydrates and several others that possess antioxidant properties. Objective: The objective of the present study was to investigate the neuroprotective potential of M. quadrifolia against monosodium glutamate (MSG)-induced excitotoxicity in rats. Methods: A high-performance thin-layer chromatography (HPTLC) analysis of chloroform extract of M. quadrifolia (CEMQ) was conducted to identify the major constituents. Further, the in silico docking analysis was carried out on selected ligands. To confirm CEMQ's neuroprotective effects, the locomotor activity, non-spatial memory, and learning were assessed. Results and discussion: The present study confirmed that CMEQ contains quercetin and its derivatives in large. The in-silico findings indicated that quercetin has a better binding affinity (-7.9 kcal/mol) towards the protein target 5EWJ. Animals treated with MSG had 1) a greater reduction in the locomotor score and impairment in memory and learning 2) a greater increase in the blood levels of calcium and sodium and 3) neuronal disorganization, along with cerebral edema and neuronal degeneration in the brain tissues as compared to normal control animals. The changes were however, significantly improved in animals which received standard drug memantine (20 mg/kg) and CEMQ (200 and 400 mg/kg) as compared to the negative control. It is plausible that the changes seen with CEMQ may be attributed to the N-methyl-D-aspartate (NMDA) antagonistic properties. Conclusion: Overall, this study indicated that M. quadrifolia ameliorated MSG-induced neurotoxicity. Future investigations are required to explore the neuroprotective mechanism of M. quadrifolia and its active constituents, which will provide exciting insights in the therapeutic management of neurological disorders.

8.
ACS Nano ; 16(11): 18187-18199, 2022 11 22.
Article in English | MEDLINE | ID: mdl-36326201

ABSTRACT

The rechargeable lithium-oxygen (Li-O2) battery has the highest theoretical specific energy density of any rechargeable batteries and could transform energy storage systems if a practical device could be attained. However, among numerous challenges, which are all interconnected, are polarization due to sluggish kinetics, low cycle life, small capacity, and slow rates. In this study, we report on use of KMnO4 to generate a colloidal electrolyte made up of MnO2 nanoparticles. The resulting electrolyte provides a redox mediator for reducing the charge potential and lithium anode protection to increase cycle life. This electrolyte in combination with a stable binary transition metal dichalcogenide alloy, Nb0.5Ta0.5S2, as the cathode enables the operation of a Li-O2 battery at a current density of 1 mA·cm-2 and specific capacity ranging from 1000 to 10 000 mA·h·g-1 (corresponding to 0.1-1 mA·h·cm-2) in a dry air environment with a cycle life of up to 150. This colloidal electrolyte provides a robust approach for advancing Li-air batteries.

9.
Small ; 18(4): e2102902, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35083855

ABSTRACT

Lithium-oxygen batteries are among the most attractive alternatives for future electrified transportation. However, their practical application is hindered by many obstacles. Due to the insulating nature of Li2 O2 product and the slow kinetics of reactions, attaining sustainable low charge overpotentials at high rates becomes a challenge resulting in the battery's early failure and low round trip efficiency. Herein, outstanding characteristics are discovered of a conductive metal organic framework (c-MOF) that promotes the growth of nanocrystalline Li2 O2 with amorphous regions. This provides a platform for the continuous growth of Li2 O2 units away from framework, enabling a fast discharge at high current rates. Moreover, the Li2 O2 structure works in synergy with the redox mediator (RM). The conductivity of the amorphous regions of the Li2 O2 allows the RM to act directly on the Li2 O2 surface instead of catalyst edges and then transport through the electrolyte to the Li2 O2 surface. This direct charge transfer enables a small charge potential of <3.7 V under high current densities (1-2 A g-1 ) sustained for a long cycle life (100-300 cycles) for large capacities (1000-2000 mAh g-1 ). These results open a new direction for utilizing c-MOFs towards advanced energy storage systems.

10.
Front Pharmacol ; 13: 1094351, 2022.
Article in English | MEDLINE | ID: mdl-36618946

ABSTRACT

The primary and considerable weakening event affecting elderly individuals is age-dependent cognitive decline and dementia. Alzheimer's disease (AD) is the chief cause of progressive dementia, and it is characterized by irreparable loss of cognitive abilities, forming senile plaques having Amyloid Beta (Aß) aggregates and neurofibrillary tangles with considerable amounts of tau in affected hippocampus and cortex regions of human brains. AD affects millions of people worldwide, and the count is showing an increasing trend. Therefore, it is crucial to understand the underlying mechanisms at molecular levels to generate novel insights into the pathogenesis of AD and other cognitive deficits. A growing body of evidence elicits the regulatory relationship between the mammalian target of rapamycin (mTOR) signaling pathway and AD. In addition, the role of autophagy, a systematic degradation, and recycling of cellular components like accumulated proteins and damaged organelles in AD, is also pivotal. The present review describes different mechanisms and signaling regulations highlighting the trilateral association of autophagy, the mTOR pathway, and AD with a description of inhibiting drugs/molecules of mTOR, a strategic target in AD. Downregulation of mTOR signaling triggers autophagy activation, degrading the misfolded proteins and preventing the further accumulation of misfolded proteins that inhibit the progression of AD. Other target mechanisms such as autophagosome maturation, and autophagy-lysosomal pathway, may initiate a faulty autophagy process resulting in senile plaques due to defective lysosomal acidification and alteration in lysosomal pH. Hence, the strong link between mTOR and autophagy can be explored further as a potential mechanism for AD therapy.

11.
Small ; 17(42): e2102072, 2021 10.
Article in English | MEDLINE | ID: mdl-34528359

ABSTRACT

Lithium-oxygen (Li-O2 ) batteries possess the highest theoretical energy density (3500 Wh kg-1 ), which makes them attractive candidates for modern electronics and transportation applications. In this work, an inexpensive, flexible, and wearable Li-O2 battery based on the bifunctional redox mediator of InBr3 , MoS2 cathode catalyst, and Fomblin-based oxygen permeable membrane that enable long-cycle-life operation of the battery in pure oxygen, dry air, and ambient air is designed, fabricated, and tested. The battery operates in ambient air with an open system air-breathing architecture and exhibits excellent cycling up to 240 at the high current density of 1 A g-1 with a relative humidity of 75%. The electrochemical performance of the battery including deep-discharge capacity, and rate capability remains almost identical after 1000 cycle in a bending fatigue test. This finding opens a new direction for utilizing high performance Li-O2 batteries for applications in the field of flexible and wearable electronics.


Subject(s)
Electric Power Supplies , Lithium , Catalysis , Electrodes , Oxygen
12.
RSC Adv ; 10(65): 39763-39770, 2020 Oct 27.
Article in English | MEDLINE | ID: mdl-35515396

ABSTRACT

This report presents a three-dimensional (3-D) magnetoelectrokinetic model to investigate a new approach to magnetic-field assisted dielectrophoresis for ultra-high precision and parallel assembly of ferromagnetic Ni nanowires (NWs) on silicon chips. The underlying assembly methodology relies on a combination of electric and magnetic fields to manipulate single nanowires from a colloidal suspension and yield their assembly on top of electrodes with better than 25 nm precision. The electric fields and the resultant dielectrophoretic forces are generated through the use of patterned gold nanoelectrodes, and deliver long-range forces that attract NWs from farther regions of the workspace and bring them in proximity to the nanoelectrodes. Next, magnetic-fields generated by cobalt magnets, which are stacked on top of the gold nanoelectrodes at their center and pre-magnetized using external magnetic fields, deliver short range forces to capture the nanowires precisely on top of the nanomagnets. The 3-D NanoMagnetoElectrokinetic model, which is built using a finite element code in COMSOL software and with further computations in MATLAB, computes the trajectory and final deposition location as well as orientation for all possible starting locations of a Ni NW within the assembly workspace. The analysis reveals that magnetic-field assisted dielectrophoresis achieves ultra-high precision assembly of NWs on top of the cobalt nanomagnets from a 42% larger workspace volume as compared to pure dielectrophoresis and thereby, establishes the benefits of adding magnetic fields to the assembly workspace. Furthermore, this approach is combined with a strategy to confine the suspension within the reservoir that contains a high density of favorable NW starting locations to deliver high assembly yields for landing NWs on top of contacts that are only twice as wide as the NWs.

13.
RSC Adv ; 10(42): 25022-25028, 2020 Jun 29.
Article in English | MEDLINE | ID: mdl-35517438

ABSTRACT

A numerical simulation is presented for predicting the transient ejection of micro-/nano-scopic jets from microscale nozzles, when a liquid confined within the nozzle is subjected to an external electric field. This simulation is based on the Taylor-Melcher leaky dielectric model, and uses the phase field method for interface tracking. The presented model is able to successfully simulate the deformation of a flat liquid meniscus into a Taylor cone, eventually leading to jet formation and breakup into droplets. Several simulations are performed to understand the effect of process parameters like applied voltage, liquid flow rate and properties on jet ejection dynamics. The results reveal the dependence of the ejected jet diameter and current primarily on the applied electric potential, liquid flow rate and electrical conductivity of the liquid. For high conductivity liquids, it is found that the convection current is of the same order of magnitude as the conduction current. In contrast, the convection current dominates the conduction current during jet ejection in the case of low conductivity liquids, regardless of the flow rate. It is also found that stable jets smaller than 200 nm can be produced from a 2 µm nozzle, which would facilitate patterning structures at the nanoscale. This model presents an approach to analyze the effect of process parameters on electrojet ejections and can effectively guide the design of printheads for e-jet systems that pattern nanoscale features in jetting and nano-dripping modes from microscopic nozzles.

15.
Nanotechnology ; 30(47): 47LT02, 2019 Nov 22.
Article in English | MEDLINE | ID: mdl-31437822

ABSTRACT

At the macroscopic size regime, ceramic materials exhibit brittle fracture and catastrophic failure when they are subjected to mechanical loads that exceed their characteristic strength. In this report, we present recoverable plasticity in alpha-phase, potassium stabilized manganese dioxide nanowire (α-K0.13MnO2 NW) crystals when they are subjected to atomic force microscopy (AFM) based three-point bending tests at very low loading rates. The force-deflection curves and AFM scans obtained from these measurements reveal yielding and extended plasticity in the NWs during the loading process, while the large plastic deformation is recovered spontaneously during the unloading process. However, the same material system exhibits failure via fracture at substantially higher strengths when it is subjected to bending tests at nearly an order of magnitude higher loading rates. These results highlight an important new pathway to controllably tune the nanomechanical performance of these technologically important nanoceramics for application-specific needs: either achieve self-reversible and ultra-large plasticity, or achieve substantially higher fracture strengths that approach the intrinsic limits of the material system.

16.
Nanoscale ; 11(18): 8959-8966, 2019 May 09.
Article in English | MEDLINE | ID: mdl-31017158

ABSTRACT

This paper reports on plastic recovery and self-healing behavior in longitudinally-twinned and [112] orientated SiGe nanowire (NW) beams when they are subjected to large bending strains. The NW alloys are comprised of lamellar nanotwin platelet(s) sandwiched between two semi-cylindrical twins. The loading curves, which are acquired from atomic force microscope (AFM) based three-point bending tests, reveal the onset of plastic deformation at a characteristic stress threshold, followed by further straining of the NWs. This ductility is attributed to dislocation activity within the semi-cylindrical crystal portions of the NW, which are hypothesized to undergo a combination of elastic and plastic straining. On the other hand, the lamellar nanoplatelets undergo purely elastic stretching. During the unloading process, the release of internal elastic stresses enables dislocation backflow and escape at the surface. As a result, the dislocations are predominantly annihilated and the NW samples evidenced self-healing via plastic recovery even at ultra-large strains, which are estimated using finite-element models at 16.3% in one of the tested devices. Finite element analysis also establishes the independence of the observed nanomechanical behavior on the relative orientation of the load with respect to the nanoplatelet. This first observation of reversible plasticity in the SiGe material system, which is aided by a concurrent evolution of segmented elastic and plastic deformation within its grains during the loading process, presents an important new pathway for mechanical stabilization of technologically important group-IV semiconductor nanomaterials.

17.
Nanoscale Adv ; 1(1): 357-366, 2019 Jan 15.
Article in English | MEDLINE | ID: mdl-36132478

ABSTRACT

Atomic force microscopy (AFM) based nanomechanics experiments involving polytypic todorokite-like manganese dioxide nanobelts reveal varied nanomechanical performance regimes such as brittle fracture, near-brittle fracture, and plastic recovery within the same material system. These nanobelts are synthesized through a layer-to-tunnel material transformation pathway and contain one-dimensional tunnels, which run along their longitudinal axis and are enveloped by m × 3 MnO6 octahedral units along their walls. Depending on the extent of material transformation towards a tunneled microstructure, the nanobelts exhibit stacking disorders or polytypism where the value for m ranges from 3 to up to ∼20 within different cross-sectional regions of the same nanobelt. The observation of multiple nanomechanical performance regimes within a single material system is attributed to a combination of two factors: (a) the extent of stacking disorder or polytypism within the nanobelts, and (b) the loading (or strain) rate of the AFM nanomechanics experiment. Controllable engineering of recoverable plasticity is a particularly beneficial attribute for advancing the mechanical stability of these ceramic materials, which hold promise for insertion in multiple next-generation technological applications that range from electrical energy storage solutions to catalysis.

18.
Nanotechnology ; 30(2): 025301, 2019 Jan 11.
Article in English | MEDLINE | ID: mdl-30398168

ABSTRACT

Floating electrode dielectrophoresis (FE-DEP) presents a promising avenue for scalable assembly of nanowire (NW) arrays on silicon chips and offers better control in limiting the number of deposited NWs when compared with the conventional, two-electrode DEP process. This article presents a 3D nanoelectrokinetic model, which calculates the imposed electric field and its resultant NW force/velocity maps within the region of influence of an electrode array operating in the FE-DEP configuration. This enables the calculation of NW trajectories and their eventual localization sites on the target electrodes as a function of parameters such as NW starting position, NW size, the applied electric field, suspension concentration, and deposition time. The accuracy of this model has been established through a direct quantitative comparison with the assembly of manganese dioxide NW arrays. Further analysis of the computed data reveals interesting insights into the following aspects: (a) asymmetry in NW localization at electrode sites, and (b) the workspace regions from which NWs are drawn to assemble such that their center-of-mass is located either in the inter-electrode gap region (desired) or on top of one of the assembly electrodes (undesired). This analysis is leveraged to outline a strategy, which involves a physical confinement of the NW suspension within lithographically patterned reservoirs during assembly, for single NW deposition across large arrays with high estimated assembly yields on the order of 87%.

19.
Science ; 330(6010): 1515-20, 2010 Dec 10.
Article in English | MEDLINE | ID: mdl-21148385

ABSTRACT

We report the creation of a nanoscale electrochemical device inside a transmission electron microscope--consisting of a single tin dioxide (SnO(2)) nanowire anode, an ionic liquid electrolyte, and a bulk lithium cobalt dioxide (LiCoO(2)) cathode--and the in situ observation of the lithiation of the SnO(2) nanowire during electrochemical charging. Upon charging, a reaction front propagated progressively along the nanowire, causing the nanowire to swell, elongate, and spiral. The reaction front is a "Medusa zone" containing a high density of mobile dislocations, which are continuously nucleated and absorbed at the moving front. This dislocation cloud indicates large in-plane misfit stresses and is a structural precursor to electrochemically driven solid-state amorphization. Because lithiation-induced volume expansion, plasticity, and pulverization of electrode materials are the major mechanical effects that plague the performance and lifetime of high-capacity anodes in lithium-ion batteries, our observations provide important mechanistic insight for the design of advanced batteries.

20.
ACS Nano ; 3(10): 2953-64, 2009 Oct 27.
Article in English | MEDLINE | ID: mdl-19739601

ABSTRACT

We report on the electromechanical actuation and switching performance of nanoconstructs involving doubly clamped, individual multiwalled carbon nanotubes. Batch-fabricated, three-state switches with low ON-state voltages (6.7 V average) are demonstrated. A nanoassembly architecture that permits individual probing of one device at a time without crosstalk from other nanotubes, which are originally assembled in parallel, is presented. Experimental investigations into device performance metrics such as hysteresis, repeatability and failure modes are presented. Furthermore, current-driven shell etching is demonstrated as a tool to tune the nanomechanical clamping configuration, stiffness, and actuation voltage of fabricated devices. Computational models, which take into account the nonlinearities induced by stress-stiffening of 1-D nanowires at large deformations, are presented. Apart from providing accurate estimates of device performance, these models provide new insights into the extension of stable travel range in electrostatically actuated nanowire-based constructs as compared to their microscale counterparts.

SELECTION OF CITATIONS
SEARCH DETAIL