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1.
Opt Lett ; 48(5): 1208-1211, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36857250

RESUMO

We study the coherence characteristics of light propagating in nonlinear graded-index (GRIN) multimode fibers after attaining optical thermal equilibrium conditions. The role of optical temperature on the spatial mutual coherence function and the associated correlation area is systematically investigated. In this respect, we show that the coherence properties of the field at the output of a multimode nonlinear fiber can be controlled through its optical thermodynamic properties.

2.
Opt Lett ; 48(8): 2206-2209, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-37058678

RESUMO

We investigate the statistical mechanics of the photonic Ablowitz-Ladik lattice, the integrable version of the discrete nonlinear Schrödinger equation. In this regard, we demonstrate that in the presence of perturbations, the complex response of this system can be accurately captured within the framework of optical thermodynamics. Along these lines, we shed light on the true relevance of chaos in the thermalization of the Ablowitz-Ladik system. Our results indicate that when linear and nonlinear perturbations are incorporated, this weakly nonlinear lattice will thermalize into a proper Rayleigh-Jeans distribution with a well-defined temperature and chemical potential, in spite of the fact that the underlying nonlinearity is non-local and hence does not have a multi-wave mixing representation. This result illustrates that in the supermode basis, a non-local and non-Hermitian nonlinearity can in fact properly thermalize this periodic array in the presence of two quasi-conserved quantities.

3.
Langmuir ; 39(6): 2333-2346, 2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36719844

RESUMO

Antifouling (AF) nanocoatings made of polydimethylsiloxane (PDMS) are more cost-efficient and eco-friendly substitutes for the already outlawed tributyltin-based coatings. Here, a catalytic hydrosilation approach was used to construct a design inspired by composite mosquito eyes from non-toxic PDMS nanocomposites filled with graphene oxide (GO) nanosheets decorated with magnetite nanospheres (GO-Fe3O4 nanospheres). Various GO-Fe3O4 hybrid nanofillers were dispersed into the PDMS resin through a solution casting method to evaluate the structure-property relationship. A simple coprecipitation procedure was used to fabricate magnetite nanospheres with an average diameter of 30-50 nm, a single crystal structure, and a predominant (311) lattice plane. The uniform bioinspired superhydrophobic PDMS/GO-Fe3O4 nanocomposite surface produced had a micro-/nano-roughness, low surface-free energy (SFE), and high fouling release (FR) efficiency. It exhibited several advantages including simplicity, ease of large-area fabrication, and a simultaneous offering of dual micro-/nano-scale structures simply via a one-step solution casting process for a wide variety of materials. The superhydrophobicity, SFE, and rough topology have been studied as surface properties of the unfilled silicone and the bioinspired PDMS/GO-Fe3O4 nanocomposites. The coatings' physical, mechanical, and anticorrosive features were also taken into account. Several microorganisms were employed to examine the fouling resistance of the coated specimens for 1 month. Good dispersion of GO-Fe3O4 hybrid fillers in the PDMS coating until 1 wt % achieved the highest water contact angle (158° ± 2°), the lowest SFE (12.06 mN/m), micro-/nano-roughness, and improved bulk mechanical and anticorrosion properties. The well-distributed PDMS/GO-Fe3O4 (1 wt % nanofillers) bioinspired nanocoating showed the least biodegradability against all the tested microorganisms [Kocuria rhizophila (2.047%), Pseudomonas aeruginosa (1.961%), and Candida albicans (1.924%)]. We successfully developed non-toxic, low-cost, and economical nanostructured superhydrophobic FR composite coatings for long-term ship hull coatings. This study may expand the applications of bio-inspired functional materials because for multiple AF, durability and hydrophobicity are both important features in several industrial applications.

4.
Mikrochim Acta ; 188(4): 138, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33772377

RESUMO

An electrochemical sensor-based phosphorus-doped microporous carbon spheroidal structures (P-MCSs) has been designed for selective adrenaline (ADR) signaling in human blood serum. The P-MCS electrode sensor is built with heterogeneous surface alignments including multiple porous sizes with open holes and meso-/macro-grooves, rough surface curvatures, and integral morphology with interconnected and conjugated microspheres. In addition, the P atom-doped graphitic carbon forms highly active centers, increases charge mobility on the electrode surface, creates abundant active centers with facile functionalization, and induces binding to ADR molecules. The designed P-MCS electrode exhibits ultrasensitive monitoring of ADR with a low detection limit of 0.002 µM and high sensitivity of 4330 µA µM-1 cm-2. In addition, two electrochemical techniques, namely, square wave voltammetry (SWV) and chronoamperometry (CA), were used; these techniques achieve high stability, fast response, and a wide linear range from 0.01 to 6 µM. The sensing assays based on P-MCSs provide evidence of the formation of active interfacial surface-to-ADR binding sites, high electron diffusion, and heavy target loads along with/without a plane of spheroids. Thus, P-MCSs can be used for the routine monitoring of ADR in human blood serum, providing a fast response, and requiring highly economical materials at extremely low concentrations. Electrode surface modulation based on P-doped carbon spheres (P-MCS) exhibits high electrochemical activity with fast charge transport, multi-diffusible active centers, high loading of ADR, and facile molecular/electron diffusion at its surface. The P-MCS sensitively and selectively detects the ADR in human fluids and can be used for clinical investigation of some neuronal diseases such as Alzheimer diseases.


Assuntos
Carbono/química , Técnicas Eletroquímicas/métodos , Epinefrina/sangue , Adsorção , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/instrumentação , Eletrodos , Epinefrina/química , Humanos , Limite de Detecção , Oxirredução , Fósforo/química , Porosidade , Reprodutibilidade dos Testes
5.
Ann Vasc Surg ; 50: 218-224, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29481939

RESUMO

BACKGROUND: Multiple studies have shown that patch angioplasty after carotid endarterectomy (CEA) reduces the risk of stroke and restenosis when compared with primary closure. Biological, synthetic, or vein patches have been traditionally used in CEA. This article reports the early and long-term outcomes of bovine pericardium (BP) for patch angioplasty in CEA. METHODS: A retrospective, consecutive analysis of 874 patients who underwent CEA during the past 17 years at Mayo Clinic, Florida, was performed. BP patch (BPP) was used in 680 patients. Other CEA techniques were used in 194 patients (standard without patch, 78; standard with Dacron, 74; standard with vein patch, 16; and other techniques: bypasses, 26). We defined group 1 as those who underwent BPP angioplasty and group 2 as those who underwent all other techniques. Early and late clinical outcomes and patch-related complications (restenosis, infection, and hematoma) were recorded and analyzed. RESULTS: Median follow-up for the entire series was 39.6 months. There were no statistically significant differences in 30-day mortality and morbidity between the 2 groups, except that BP group has less 30-day stroke (0.1%, 1 of 680) versus other techniques (1.5%, 3 of 194, P = 0.03). Thirty-day postoperative mortality rate was 0.1% (1 of 680) in BPP group and 1.0% (2 of 194) in other technique group (P = 0.13). No statistically significant difference was noted in 30-day postoperative major complications (transient ischemic attack [TIA], wound infection, hematoma requiring surgical evacuation, and nerve injury) between the 2 groups. Ten-year freedom from stroke/TIA were 97.8% in the BP group compared with 98.5% in the other group (P = 0.86). Ten-year freedom from restenosis was also similar between groups (89.0% BP vs. 90.4% others, P = 0.69). Ten-year survival rate was 38.4% in BP group and 45.0% in other technique group, and this was statistically significant on univariate analysis only. CONCLUSIONS: CEA with BP angioplasty has excellent early and late outcomes with minor morbidity and mortality.


Assuntos
Angioplastia/métodos , Estenose das Carótidas/cirurgia , Endarterectomia das Carótidas , Pericárdio/transplante , Adulto , Idoso , Idoso de 80 Anos ou mais , Angioplastia/efeitos adversos , Angioplastia/mortalidade , Animais , Estenose das Carótidas/complicações , Estenose das Carótidas/mortalidade , Bovinos , Endarterectomia das Carótidas/efeitos adversos , Endarterectomia das Carótidas/mortalidade , Feminino , Florida , Hematoma/etiologia , Humanos , Ataque Isquêmico Transitório/etiologia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Recidiva , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/etiologia , Infecção da Ferida Cirúrgica/etiologia , Fatores de Tempo , Transplante Heterólogo , Resultado do Tratamento
6.
J Hazard Mater ; 478: 135429, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39128154

RESUMO

Real-time monitoring and tracking of extreme toxins that penetrate into living cells by using biocompatible, low-cost visual detection via fluorescent monitors are vitally essential to reduce health hazards. Herein, we report a simple engineering design of biocompatible and fluorescent sensors/trackers for real-time monitoring and ultra-trace tracking (up to ppb) of extremely toxic substances (such as arsenic species) in living cells. The biocompatible As(V) sensor (BAS) design is fabricated via successful dressing/decoration process of 2-hydroxy 5-methyl isophthalaldehyde fluorescent receptor into hierarchical organic-inorganic carriers that have micro-hollow geodes, swirled caves and nest-shaped cages, and uniform cubic structures. The BAS monitors show evidence for the selective trapping/detecting/tracking of As(V) species in biological cells (i.e., HeLa cells) despite the coexistence of highly competitive and interfered species. Our simple batch-contact sensing assays shows real-space evidence of the continuous monitoring of As(V) species in HeLa cells with ultra-sensitive detection (i.e., with a low detection limit of 0.149 ppb) and rapid recognition (i.e., in the order of seconds). Significantly, the BAS monitors did not affect the cell population and achieved low cytotoxicity and high cell viability during the monitoring/tracking process inside HeLa cells. The high biocompatibility of BAS remarkably allows precise quantification and real-time monitoring/tracking of toxicant targets in living cells.

7.
J Hazard Mater ; 465: 133271, 2024 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-38141313

RESUMO

The extraordinary accumulation of cyanide ions within biological cells is a severe health risk. Detecting and tracking toxic cyanide ions within these cells by simple and ultrasensitive methodologies are of immense curiosity. Here, continuous tracking of ultimate levels of CN--ions in HeLa cells was reported employing biocompatible branching molecular architectures (BMAs). These BMAs were engineered by decorating colorant-laden dendritic branch within and around the molecular building hollows of the geode-shelled nanorods of organic-inorganic Al-frameworks. Batch-contact methods were utilized to assess the potential of hollow-nest architecture for inhibition/evaluation of toxicant CN--ions within HeLa cells. The nanorod BMAs revealed significant potential capabilities in monitoring and tracking of CN- ions (88 parts per trillion) in biological trials within seconds. These results demonstrated sufficient evidence for the compatibility of BMAs during HeLa cell exposure. Under specific conditions, the BMAs were utilized for in-vitro fluorescence tracking/sensing of CN- in HeLa cells. The cliff swallow nest with massive mouths may have the potential to reduce the health hazards associated with toxicant exposure in biological cells.


Assuntos
Estruturas Metalorgânicas , Humanos , Células HeLa , Íons , Cianetos , Substâncias Perigosas
8.
Noncoding RNA ; 9(5)2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37888208

RESUMO

Ribonucleic acids (RNAs) are important regulators of gene expression and crucial for the progression of hepatocellular carcinoma (HCC). This study was designed to determine the diagnostic and prognostic utility of the circulating long miscellaneous RNAs; LINC01419, AK021443, and AF070632 in HCV-related HCC patients. Real-time PCR was used to measure their relative expression levels in the plasma of 194 HCV patients, 120 HCV-related HCC patients and 120 healthy controls. LINC01419 and AK021443 expression levels had significantly increasing linear trend estimates while AF070632 was dramatically downregulated in HCC compared to HCV. Interestingly, LINC01419 and AK021443 served as more significant diagnostic biomarkers for HCC than AF070632 and AFP. Multivariate analysis with cox regression revealed that the high expression of AK021443 [HR = 10.06, CI95%: 3.36-30.07], the high expression of LINC01419 [HR 4.13, CI95%: 1.32-12.86], and the low expression of AF070632 [HR = 2.70, CI95%: 1.07-6.81] were significant potential prognostic factors for HCC. Besides, the Kaplan-Meier analysis showed that HCC patients with high LIN01419 and AK021443 and low AF070632 expression levels had shorter OS. The circulating LINC01419 and AK021443 can be used as noninvasive potential biomarkers for diagnosis and prognosis of HCV-related HCC patients than AF070632 providing new targets for limiting the progression of the disease.

9.
Comput Methods Biomech Biomed Engin ; 25(13): 1531-1543, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34986079

RESUMO

The hydrothermal features of unsteady, incompressible, and laminar hybrid nanofluid motion through a porous capillary are analytically studied in the magnetic field presence. The hybrid nanofluid (GO + ZnO + Blood) is synthesized by blending nanomaterials of graphene oxide and zinc oxide with blood acting as the host fluid. The mathematical model of the flow comprises of a coupled nonlinear set of partial differential equations (PDEs) satisfying appropriate boundary conditions. These equations are reduced to ordinary differential equations (ODEs) by using similarity transformations and then solved with homotopy analysis method (HAM). The impacts of various pertinent physical parameters over the hybrid nanofluid state functions are examined by displaying 2 D graphs. It has been observed that the fluid velocity mitigates with the varying strength of M, A0, N0, and N1. The enhancing buoyancy parameter ϵ augments the fluid velocity. The increasing Prandtl number causes to reduce, while the enhancing A0, B, and N2 augment the hybrid nanofluid temperature. The fluid concentration mitigates with the higher Schmidt number values and A0, and augments with the increasing Soret number strength. The augmenting magnetic field strength causes to enhance the fluid friction, whereas the convective heat transfer increases with the Prandtl number rising values. The rising Sherwood number drops the mass transfer rate of the fluid. The achieved results are validated due to the agreement with the published results. The results of this computation will find applications in biomedicine, nanotechnology, and fluid dynamics.


Assuntos
Óxido de Zinco , Hidrodinâmica , Modelos Teóricos , Nanotecnologia/métodos , Porosidade
10.
Colloids Surf B Biointerfaces ; 210: 112228, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34839049

RESUMO

Follow up of neuronal disorders, such as Alzheimer's and Parkinson's diseases using simple, sensitive, and selective assays is urgently needed in clinical and research investigation. Here, we designed a sensitive and selective enzymeless electrochemical acetylcholine sensor that can be used in human fluid samples. The designed electrode consisted of a micro spherical construction of Cu-metal decorated by a thin layer of carbon (CuMS@C). A simple and one-pot synthesis approach was used for Cu-metal controller formation with a spherical like structures. The spherical like structure was formed with rough outer surface texture, circular build up, homogeneous formation, micrometric spheres size (0.5 -1 µm), and internal hollow structure. The formation of a thin layer of carbon materials on the surface of CuMS sustained the catalytic activity of Cu atoms and enriched negatively charge of the surface. CuMS@C acted as a highly active mediator surface that consisted of Cu metal as a highly active catalyst and carbons as protecting, charge transport, and attractive surface. Therefore, the CuMS@C surface morphology and composition played a key role in various aspects such as facilitated ACh diffusion/loading, increased the interface surface area, and enhanced the catalytic activity. The CuMS@C acted as an electroactive catalyst for ACh electrooxidation and current production, due to the losing of two electrons. The fabricated CuMS@C could be a highly sensitive and selective enzymeless sensor for detecting ACh with a detection limit of 0.1 µM and a wide linear range of 0.01 - 0.8 mM. The designed ACh sensor assay based on CuMS@C exhibited fast sensing property as well as sensitivity, selectivity, stability, and reusability for detecting ACh in human serum samples. This work presents the design of a highly active electrode surface for direct detection of ACh and further clinical investigation of ACh levels.


Assuntos
Técnicas Biossensoriais , Cobre , Acetilcolina , Carbono , Técnicas Eletroquímicas , Eletrodos , Humanos , Limite de Detecção , Microesferas
11.
Anal Chim Acta ; 1192: 339380, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35057967

RESUMO

To date, the production and development of portable analytical devices for environmental and healthcare applications are rapidly growing. Herein, a portable electrochemical sensor for monitoring of noradrenaline (NA) secreted from living cells using mesoporous carbon-based materials was fabricated. The modification of the interdigitated electrode array (IDA) by nitrogen-doped mesoporous carbon spheres (N-doped MCS) and nitrogen-doped carbon hollow trunk-like structure (N-doped CHT) was used to fabricate the NA sensor. The N-doped CHT surface shows multiple holes distributed with micrometer-sized open holes (1-2 µm) and nanometer-sized thin walls (∼98 nm). The N-doped CHT surface heterogeneity of wrinkled and twisted hollow trunk structures improve the diffusion pathway and the NA molecules loading. The N-doped CHT/IDA showed a highly selective assay for monitoring of NA with high sensitivity (1770 µA/µM × cm2), a low detection limit (0.005 µM), and a wide linear range (0.01-0.3 µM). The N-doped CHT/IDA monitored the NA secreted from PC12 cells under various concentrations of simulation agents (KCl). The designed N-doped CHT/IDA provides a portable NA-sensor assay with facile signaling, good stability, high biocompatibility, in-vitro assay compatibility, and good reproducibility. Therefore, the designed sensor can be used as a portable sensor for NA detection in live cells and can be matched with portable smartphones after further developments.


Assuntos
Carbono , Nitrogênio , Animais , Eletrodos , Norepinefrina , Ratos , Reprodutibilidade dos Testes
12.
Plants (Basel) ; 11(10)2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35631716

RESUMO

Cytoplasmic male sterility (CMS) provides an irreplaceable strategy for commercial exploitation of heterosis and producing high-yielding hybrid rice. The exogenous application of plant growth regulators could improve outcrossing rates of the CMS lines by affecting floral traits and accordingly increase hybrid rice seed production. The present study aimed at exploring the impact of growth regulators such as gibberellic acid (GA3), indole-3-acetic acid (IAA), and naphthalene acetic acid (NAA) on promoting floral traits and outcrossing rates in diverse rice CMS lines and improving hybrid rice seed production. The impact of foliar applications of growth regulators comprising GA3 at 300 g/ha or GA3 at 150 g/ha + IAA at 50 g/ha + NAA at 200 g/ha versus untreated control was investigated on floral, growth, and yield traits of five diverse CMS lines. The exogenously sprayed growth regulators, in particular, the combination of GA3, IAA, and NAA (T3) boosted all studied floral, growth, and yield traits in all tested CMS lines. Moreover, the evaluated CMS lines exhibited significant differences in all measured floral traits. L2, L3, and L1 displayed the uppermost spikelet opening angle, duration of spikelet opening, total stigma length, style length, stigma brush, and stigma width. In addition, these CMS lines exhibited the highest plant growth and yield traits, particularly under T3. Consequently, exogenous application of GA3, IAA, and NAA could be exploited to improve the floral, growth, and yield traits of promising CMS lines such as L2, L3, and L1, hence increasing outcrossing rates and hybrid rice seed production.

13.
Sci Rep ; 11(1): 19604, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34599255

RESUMO

Involvement of hybrid nanoparticles a vital role to improve the efficiency of thermal systems. This report covers the utilization of different nanoparticles mixed in Carreau Yasuda material for the improvement of thermal performance. The configuration of flow situation is considered over a rotating porous cone by considering the Hall and Ion slip forces. Transport of momentum is considered to be in a rotating cone under generalized ohm's law and heat transfer is presented by considering viscous dissipation, Joule heating and heat generation. Rheology of considered model is derived by engaging the theory proposed by Prandtl. Modeled complex PDEs are reduced into ODEs under similarity transformation. To study the physics behind this phenomenon, solution is essential. Here, FEM (Finite Element Method) is adopted to compute the solution. Furthermore, the grid independent study is reported with several graphs and tables which are prepared to note the influence of involved parameters on thermal and velocity fields. It is worth mentioning that heat transport is controlled via higher radiation parameter and it upsurges for Eckert number. Moreover, Hall and ion slip parameters are considered significant parameters to produce the enhancement in motion of fluid particles but speed of nano and hybrid nanoparticles becomes slow down versus large values of Forchheimer and Weissenberg numbers. Additionally, an enhancement in production of heat energy is addressed via large values of heat generation number and Eckert number while reduction in heat energy is occurred due to positive values of thermal radiation and Hall and ion slip parameters.

14.
PLoS One ; 16(7): e0251744, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34197471

RESUMO

The free convective hybrid nanofluid (Fe3O4+MWCNT/H2O) magnetized non-Darcy flow over a porous cylinder is examined by considering the effects constant heat source and uniform ambient magnetic field. The developed coupled PDEs (partial differential equations) are numerically solved using the innovative computational technique of control volume finite element method (CVFEM). The impact of increasing strength of medium porousness and Lorentz forces on the hybrid nanofluid flow are presented through contour plots. The variation of the average Nusselt number (Nuave) with the growing medium porosity, buoyancy forces, radiation parameter, and the magnetic field strength is presented through 3-D plots. It is concluded that the enhancing medium porosity, buoyancy forces and radiation parameter augmented the free convective thermal energy flow. The rising magnetic field rises the temperature of the inner wall more drastically at a smaller Darcy number. An analytical expression for Nusselt number (Nuave) is obtained which shows its functional dependence on the pertinent physical parameters. The augmenting Lorentz forces due to the higher estimations of Hartmann retard the hybrid nanoliquid flow and hence enhance the conduction.


Assuntos
Algoritmos , Óxido Ferroso-Férrico/química , Nanoestruturas/química , Nanotubos de Carbono/química , Água/química , Análise de Elementos Finitos , Campos Magnéticos , Porosidade , Temperatura
15.
Biosens Bioelectron ; 185: 113237, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33932881

RESUMO

On-demand screening, real-time monitoring and rapid diagnosis of ubiquitous diseases, such as diabetes, at early stages are indispensable in personalised treatment. Emerging impacts of nano/microscale materials on optical and portable biosensor strips and devices have become increasingly important in the remarkable development of sensitive visualisation (i.e. visible inspection by the human eye) assays, low-cost analyses and personalised home testing of patients with diabetes. With the increasing public attention regarding the self-monitoring of diabetes, the development of visual readout, easy-to-use and wearable biosensors has gained considerable interest. Our comprehensive review bridges the practical assessment gap between optical bio-visualisation assays, disposable test strips, sensor array designs and full integration into flexible skin-based or contact lens devices with the on-site wireless signal transmission of glucose detection in physiological fluids. To date, the fully modulated integration of nano/microscale optical biosensors into wearable electronic devices, such as smartphones, is critical to prolong periods of indoor and outdoor clinical diagnostics. Focus should be given to the improvements of invasive, wireless and portable sensing technologies to improve the applicability and reliability of screen display, continuous monitoring, dynamic data visualisation, online acquisition and self and in-home healthcare management of patients with diabetes.


Assuntos
Técnicas Biossensoriais , Dispositivos Eletrônicos Vestíveis , Glucose , Humanos , Reprodutibilidade dos Testes , Smartphone
16.
PLoS One ; 16(8): e0256302, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34432830

RESUMO

This report is prepared to examine the heat transport in stagnation point mixed convective hyperbolic tangent material flow past over a linear heated stretching sheet in the presence of magnetic dipole. Phenomenon of thermal transmission plays a vital role in several industrial manufacturing processes. Heat generation is along with thermal relaxation due to Cattaneo-Christov flux is engaged while modeling the energy equation. In order to improve the thermal performance, inclusion of hybrid nanoparticles is mixed in hyperbolic tangent liquid. The conservation laws are modeled in Cartesian coordinate system and simplified via boundary layer approximation. The modeled partial differential equations (PDEs) system are converted into ordinary differential equations (ODEs) system by engaging the scaling group transformation. The converted system of modeled equations has been tackled via finite element procedure (FEP). The efficiency of used scheme has been presented by establishing the grid independent survey. Moreover, accurateness of results is shown with the help of comparative study. It is worth mentioning that the inclusion of hybrid nanoparticles has significant higher impact on heat conduction as compared with nanoparticle. Moreover, hybrid nanoparticles are more efficient to conduct maximum production of heat energy as compared with the production of heat energy of nanoparticles. Hence, hybrid nanoparticles (MoS2/Ag) are observed more significant to conduct more heat energy rather than nanoparticle (Ag).


Assuntos
Modelos Teóricos , Nanopartículas/química , Fenômenos Físicos , Algoritmos , Elasticidade , Análise de Elementos Finitos , Temperatura Alta , Condutividade Térmica , Meios de Transporte , Viscosidade
17.
Micromachines (Basel) ; 12(8)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34442573

RESUMO

This report examines the heat and mass transfer in three-dimensional second grade non-Newtonian fluid in the presence of a variable magnetic field. Heat transfer is presented with the involvement of thermal relaxation time and variable thermal conductivity. The generalized theory for mass flux with variable mass diffusion coefficient is considered in the transport of species. The conservation laws are modeled in simplified form via boundary layer theory which results as a system of coupled non-linear partial differential equations. Group similarity analysis is engaged for the conversion of derived conservation laws in the form of highly non-linear ordinary differential equations. The solution is obtained vial optimal homotopy procedure (OHP). The convergence of the scheme is shown through error analysis. The obtained solution is displayed through graphs and tables for different influential parameters.

18.
Sci Rep ; 11(1): 17837, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34497311

RESUMO

Stretched flows have numerous applications in different industrial, biomedical and engineering processes. Current research is conducted to examine the flow phenomenon of Prandtl fluid model over a moveable surface. The phenomenon of mass and thermal transportation is based on generalized theory of Cattaneo-Christov which considers the involvement of relaxation times. In addition to these, variable characteristics of thermal conductivity and diffusion coefficient are considered as a function of temperature. The physical problem in Cartesian coordinate system is modeled via boundary layer theory which yields a coupled system of partial differential equations. Group scaling transportation is applied to model these PDEs system. The converted equations have been approximated via optimal homotopic scheme. The efficiency and validity of used approach has been shown by computing the error analysis and establishing a comparative study. It is noted that the enhancement in magnetic parameter plays a controlling role for velocity field and it augment the concentration and temperature fields. Furthermore, increase in thermal relaxation parameter and Prandtl number maintains the fluid temperature.

19.
Soft comput ; : 1-12, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34812247

RESUMO

In the current pandemic, smart technologies such as cognitive computing, artificial intelligence, pattern recognition, chatbot, wearables, and blockchain can sufficiently support the collection, analysis, and processing of medical data for decision making. Particularly, to aid medical professionals in the disease diagnosis process, cognitive computing is helpful by processing massive quantities of data rapidly and generating customized smart recommendations. On the other hand, the present world is facing a pandemic of COVID-19 and an earlier detection process is essential to reduce the mortality rate. Deep learning (DL) models are useful in assisting radiologists to investigate the large quantity of chest X-ray images. However, they require a large amount of training data and it needs to be centralized for processing. Therefore, federated learning (FL) concept can be used to generate a shared model with no use of local data for DL-based COVID-19 detection. In this view, this paper presents a federated deep learning-based COVID-19 (FDL-COVID) detection model on an IoT-enabled edge computing environment. Primarily, the IoT devices capture the patient data, and then the DL model is designed using the SqueezeNet model. The IoT devices upload the encrypted variables into the cloud server which then performs FL on major variables using the SqueezeNet model to produce a global cloud model. Moreover, the glowworm swarm optimization algorithm is utilized to optimally tune the hyperparameters involved in the SqueezeNet architecture. A wide range of experiments were conducted on benchmark CXR dataset, and the outcomes are assessed with respect to different measures . The experimental outcomes pointed out the enhanced performance of the FDL-COVID technique over the other methods.

20.
Mater Sci Eng C Mater Biol Appl ; 122: 111844, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33641886

RESUMO

Here, we study the effect of hierarchical and one-dimensional (1D) metal oxide nanorods (H-NRs) such as γ-Al2O3, ß-MnO2, and ZnO as microbial inhibitors on the antimicrobial efficiency in aqueous solution. These microbial inhibitors are fabricated in a diverse range of nanoscale hierarchical morphologies and geometrical shapes that have effective surface exposure, and well-defined 1D orientation. For instance, γ-Al2O3 H-NRs with 20 nm width and ˂0.5 µm length are grown dominantly in the [400] direction. The wurtzite structures of ß-MnO2 H-NRs with 30 nm width and 0.5-1 µm length are preferentially oriented in the [100] direction. Longitudinal H-NRs with a width of 40 nm and length of 1 µm are controlled with ZnO wurtzite structure and grown in [0001] direction. The antimicrobial efficiency of H-NRs was evaluated through experimental assays using a set of microorganisms (Gram-positive Staphylococcus aureus, Bacillus thuriginesis, and Bacillus subtilis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. Minimal inhibitory and minimum bactericidal concentrations (MIC and MBC) were determined. These 1D H-NRs exhibited antibacterial activity against all the used strains. The active surface exposure sites of H-NRs play a key role in the strong interaction with the thiol units of vital bacterial enzymes, leading to microbial inactivation. Our finding indicates that the biological effect of the H-NR surface planes on microbial inhibition is decreased in the order of [400]-γ-Al2O3 > [100]-ß-MnO2 > [0001]-ZnO geometrics. The lowest key values including MIC (1.146 and 0.250 µg/mL), MBC (1.146, 0.313 µg/mL), and MIC/MFC (0.375 and 0.375 µg/mL) are achieved for [400]-plane γ-Al2O3 surfaces when tested against Gram-positive and -negative bacteria, respectively. Among the three H-NRs, the smallest diameter size and length, the largest surface area, and the active exposure [400] direction of γ-Al2O3 H-NRs could provide the highest microbial inactivation.


Assuntos
Bactérias Gram-Negativas , Compostos de Manganês , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Viabilidade Microbiana , Óxidos
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