Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Small ; : e2402015, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38597684

RESUMO

Water electrolysis is among the recent alternatives for generating clean fuels (hydrogen). It is an efficient way to produce pure hydrogen at a rapid pace with no unwanted by-products. Effective and cheap water-splitting electrocatalysts with enhanced activity, specificity, and stability are currently widely studied. In this regard, noble metal-free transition metal-based catalysts are of high interest. Iron sulfide (FeS) is one of the essential electrocatalysts for water splitting because of its unique structural and electrochemical features. This article discusses the significance of FeS and its nanocomposites as efficient electrocatalysts for oxygen evolution reaction (OER), hydrogen evolution reaction (HER), oxygen reduction reaction (ORR), and overall water splitting. FeS and its nanocomposites have been studied also for energy storage in the form of electrode materials in supercapacitors and lithium- (LIBs) and sodium-ion batteries (SIBs). The structural and electrochemical characteristics of FeS and its nanocomposites, as well as the synthesis processes, are discussed in this work. This discussion correlates these features with the requirements for electrocatalysts in overall water splitting and its associated reactions. As a result, this study provides a road map for researchers seeking economically viable, environmentally friendly, and efficient electrochemical materials in the fields of green energy production and storage.

2.
Entropy (Basel) ; 26(4)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38667884

RESUMO

Complex systems are prevalent in various disciplines encompassing the natural and social sciences, such as physics, biology, economics, and sociology. Leveraging data science techniques, particularly those rooted in artificial intelligence and machine learning, offers a promising avenue for comprehending the intricacies of complex systems without necessitating detailed knowledge of underlying dynamics. In this paper, we demonstrate that multiscale entropy (MSE) is pivotal in describing the steady state of complex systems. Introducing the multiscale entropy dynamics (MED) methodology, we provide a framework for dissecting system dynamics and uncovering the driving forces behind their evolution. Our investigation reveals that the MED methodology facilitates the expression of complex system dynamics through a Generalized Nonlinear Schrödinger Equation (GNSE) that thus demonstrates its potential applicability across diverse complex systems. By elucidating the entropic underpinnings of complexity, our study paves the way for a deeper understanding of dynamic phenomena. It offers insights into the behavior of complex systems across various domains.

3.
Curr Issues Mol Biol ; 45(11): 9316-9327, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37998760

RESUMO

Here, we, for the first time, compared the cardioprotective effects of third-generation vasodilating beta-blocker nebivolol (Neb) and conventional beta-blocker metoprolol (Met) on LPS-induced injury in H9c2 cardiomyoblasts. Our findings denoted that Neb and Met pretreatment diminish LPS-mediated cytotoxicity and oxidative stress. Concomitantly, LPS-triggered inflammatory cytokines activation was significantly suppressed by Neb but not by Met. Pretreatment with either Neb or Met alleviated LPS-mediated mitochondrial impairment by enhancing the expression of genes related to its biogenesis such as PGC-1α, NRF1, and TFAM. On the contrary, Neb but not Met-upregulated mitochondrial fusion-related genes such as OPA, and MFN2. In summary, our findings suggest that Neb and Met treatment significantly ameliorated the LPS-induced cytotoxicity and oxidative stress. Additionally, these findings suggest that Neb but not Met significantly down-regulates LPS-induced proinflammatory factors, probably by enhancing mitochondrial biogenesis and fusion.

4.
J Bus Res ; 157: 113550, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36568523

RESUMO

Consumer animosity captures negative attitudes to foreign products and impacts willingness to buy them. Existing constructs nevertheless fail to account for an emerging dimension: pandemic animosity. This article heeds recent calls to develop a pandemic animosity measurement scale. Its purpose is to: (i) extend Klein et al.'s (1998) animosity model by adding the pandemic animosity construct, (ii) provide a measurement scale for pandemic animosity, and (iii) explain how pandemic animosity impacts consumers' willingness to buy. Study 1 analyzes qualitative data from in-depth personal interviews with NVivo to identify themes and codes. An expert panel helped reach consensus of all indicators. Study 2 filters scale items using a pilot sample. Study 3 validates a 12-item scale with a larger representative sample. The results contribute to the consumer animosity literature by confirming the existence of pandemic animosity, providing an actionable measure, and confirming its negative impact on consumers' willingness to buy.

5.
Des Monomers Polym ; 20(1): 419-433, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29491813

RESUMO

Eudragit E 100 and polycaprolactone (PCL) floating microspheres for enhanced gastric retention and drug release were successfully prepared by oil in water solvent evaporation method. Metronidazole benzoate, an anti-protozoal drug, was used as a model drug. Polyvinyl alcohol was used as an emulsifier. The prepared microspheres were observed for % recovery, % degree of hydration, % water uptake, % drug loading, % buoyancy and % drug release. The physico-chemical properties of the microspheres were studied by calculating encapsulation efficiency of microspheres and drug release kinetics. Drug release characteristics of microspheres were studied in simulated gastric fluid and simulated intestinal fluid i.e., at pH 1.2 and 7.4 respectively. Fourier transform infrared spectroscopy was used to reveal the chemical interaction between drug and polymers. Scanning electron microscopy was conducted to study the morphology of the synthesized microspheres.

6.
Infect Disord Drug Targets ; 24(4): 58-66, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38178666

RESUMO

Since the commencement of Corona Virus Disease 2019 (COVID-19) pandemic, which has resulted in millions of mortalities globally, the efforts to minimize the damages have equally been up to the task. One of those efforts includes the mass vaccine development initiative targeting the deadly Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). So far, vaccines have tremendously decreased the rate of transmission and infection in most parts of the world. However, the repeated resurgence of different types of mutated versions of the virus, also known as variants, has somehow created uncertainties about the efficacies of different types of vaccines. This review discusses some of the interesting SARS-CoV-2 features, including general structure, genomics, and mechanisms of variants development and their consequent immune escape. This review also focuses very briefly on antigenic drift, shift, and vaccine-developing platforms.


Assuntos
Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Eficácia de Vacinas , Humanos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/imunologia , Mutação , Desenvolvimento de Vacinas
7.
Environ Sci Pollut Res Int ; 30(22): 62341-62354, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36940029

RESUMO

Travel and tourism support a country's economy and improve its social outlook. The religious inclination is an important factor influencing tourism and constitutes a significant part of general tourism. Thus, assessing and evaluating its real impacts on a country is crucial. As the world continues to grapple with the effects of environmental degradation, numerous studies have delved into the research between tourism, energy consumption, and pollution emissions. However, the impact of religious tourism on the environment is often overlooked. To bridge this gap, this study explores the relationship between religious tourist arrivals, geopolitical risk, and environmental quality in Italy. By employing ARDL and wavelets coherence analysis on the Italian data from 1997 to 2019, the findings of this study reveal a mitigation effect of religious tourist arrivals and geopolitical risk on CO2 pollution levels. In contrast, it highlights the significance of foreign direct investment and transportation as significant contributors to CO2 pollution. In conclusion, the study highlights the crucial role that religious tourism and religious leaders can play in mitigating environmental pollution and the importance of considering this aspect in future environmental studies as well as emphasize the need for Italian authorities to pay close attention to the impact of foreign direct investment and transportation energy consumption on the environment to achieve sustainable development goals.


Assuntos
Dióxido de Carbono , Turismo , Dióxido de Carbono/análise , Desenvolvimento Sustentável , Poluição Ambiental/análise , Viagem , Desenvolvimento Econômico
8.
Antioxidants (Basel) ; 12(4)2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37107252

RESUMO

Mitochondrial dysfunction triggered by increased reactive oxygen species (ROS) generation is involved in the pathogenesis and development of cardiac hypertrophy. Nanoceria (cerium oxide nanoparticle) has powerful ROS-scavenging properties and is considered a potential therapeutic option for curbing ROS-related disorders. Here, we explored the signaling mechanism underlying the protective effects of nanoceria against angiotensin (Ang) II-stimulated pathological response in H9c2 cardiomyoblasts. Our data revealed that pretreatment of H9c2 cardiomyoblasts with nanoceria significantly prevented Ang II-stimulated generation of intracellular ROS, aberrant expression of pro-inflammatory cytokines, and hypertrophy markers. Nanoceria pretreatment increased the mRNA levels of genes regulating the cellular antioxidant defense system (SOD2, MnSOD, CAT) in Ang II-treated cells. Furthermore, nanoceria restored mitochondrial function by decreasing mitochondrial ROS, increasing mitochondrial membrane potential (MMP), and promoting the mRNA expression of genes associated with mitochondrial biogenesis (PGC-1α, TFAM, NRF1, and SIRT3) and mitochondrial fusion (MFN2, OPA1). Collectively, these findings demonstrate the protective effects of nanoceria against Ang II-mediated mitochondrial dysfunction and pathological hypertrophy in H9c2 cells.

9.
Sci Rep ; 13(1): 22205, 2023 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097737

RESUMO

This study reports the prevalence and antibiotics resistance status of Salmonella detected in raw meat from Lahore, Pakistan. Overall, N = 111 meat samples, were collected from local markets. Salmonella was recovered from 57 (51.35%) samples, including 45.83% of poultry, 60% of buffalo, 64.28% of cow, and 60% of goat meat samples. The predominant Salmonella strains were Salmonella enterica serovars; Typhimurium (45.4%), Typhi (27.2%), and Enteritidis (18.1%), identified by VITEK system and 16S rRNA gene sequencing. The isolates exhibited high resistance to Erythromycin (100%), Cefepime (98.24%), Colistin (94.73%), Azithromycin (92.98%), Tetracycline (87.71%), Polymyxin B (84.21%), Ciprofloxacin (84.21%), Trimethoprim-Sulfamethoxazole (80.70%), Nalidixic Acid (80.70%), Kanamycin (78.94%), Chloramphenicol (77.19%), Streptomycin (71.92%) and Ampicillin (64.91%). While the isolates exhibited more susceptibility to Meropenem (75.43%) and Amikacin (73.68%). N = 8 strains were designated as Multidrug Resistant (MDR) and N = 3 as Extensively Drug-Resistant (XDR) Salmonella. The PCR-based detection of resistance genes revealed the presence of blaTEM-1 gene (100%), catA1 gene (64%), and gyrA gene (18%). The whole genome sequencing (WGS) of two selected strains and subsequent downstream analysis confirmed the strains as MDR and XDR Salmonella enterica serovar Typhi. The study showed that raw meat consumed in Lahore carries a significantly high number of drug-resistant Salmonella.


Assuntos
Farmacorresistência Bacteriana Múltipla , Salmonella enterica , Animais , Feminino , Bovinos , Prevalência , Paquistão/epidemiologia , RNA Ribossômico 16S , Farmacorresistência Bacteriana Múltipla/genética , Testes de Sensibilidade Microbiana , Salmonella/genética , Carne , Antibacterianos/farmacologia , Salmonella enterica/genética
10.
Chemosphere ; 310: 136835, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36243091

RESUMO

Photocatalytic degradation is one of the most promising technologies available for removing a variety of synthetic and organic pollutants from the environmental matrices because of its high catalytic activity, reduced energy consumption, and low total cost. Due to its acceptable bandgap, broad light-harvesting efficiency, significant renewability, and stability, Fe2O3 has emerged as a fascinating material for the degradation of organic contaminants as well as numerous dyes. This study thoroughly reviewed the efficiency of Fe2O3-based nanocomposite and nanomaterials for water remediation. Iron oxide structure and various synthetic methods are briefly discussed. Additionally, the electrocatalytic application of Fe2O3-based nanocomposites, including oxygen evolution reaction, oxygen reduction reaction, hydrogen evolution reaction, and overall water splitting efficiency, was also highlighted to illustrate the great promise of these composites. Finally, the ongoing issues and future prospects are directed to fully reveal the standards of Fe2O3-based catalysts. This review is intended to disseminate knowledge for further research on the possible applications of Fe2O3 as a photocatalyst and electrocatalyst.


Assuntos
Nanocompostos , Purificação da Água , Purificação da Água/métodos , Nanocompostos/química , Catálise , Metais , Oxigênio
11.
Chemosphere ; 329: 138552, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37003438

RESUMO

Persistent contaminants in wastewater effluent pose a significant threat to aquatic life and are one of the most significant environmental concerns of our time. Although there are a variety of traditional methods available in wastewater treatment, including adsorption, coagulation, flocculation, ion exchange, membrane filtration, co-precipitation and solvent extraction, none of these have been found to be significantly cost-effective in removing toxic pollutants from the water environment. The upfront costs of these treatment methods are extremely high, and they require the use of harmful synthetic chemicals. For this reason, the development of new technologies for the treatment and recycling of wastewater is an absolute necessity. Our way of life can be made more sustainable by the synthesis of adsorbents based on biomass, making the process less harmful to the environment. Biopolymers offer a sustainable alternative to synthetic polymers, which are manufactured by joining monomer units through covalent bonding. This review presents a detailed classification of biopolymers such as pectin, alginate, chitosan, lignin, cellulose, chitin, carrageen, certain proteins, and other microbial biomass compounds and composites, with a focus on their sources, methods of synthesis, and prospective applications in wastewater treatment. A concise summary of the extensive body of knowledge on the fate of biopolymers after adsorption is also provided. Finally, consideration is given to open questions about future developments leading to environmentally friendly and economically beneficial applications of biopolymers.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Águas Residuárias , Biopolímeros/química , Celulose/química , Quitina , Água , Poluentes Químicos da Água/química , Adsorção
12.
Infect Disord Drug Targets ; 22(7): 7-13, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35388765

RESUMO

Since the advent of the COVID-19 pandemic in 2019, a mammoth research activity targeting the etiological features of COVID-19 has commenced. Many aspects of the disease have been studied, and various others are under consideration. The secondary microbial coinfections with COVID-19 have generated some serious concerns across the globe. This review mainly focuses on the notable secondary coinfections. The coinfection of influenza, tuberculosis, and typhoid may mimic the original COVID-19 symptoms. Physicians and clinicians must focus on the secondary coinfections which may aggravate the disease progression towards acute respiratory disorder syndrome (ARDS). Diagnostic strategies must also be redefined to determine the actual underlying secondary coinfection. There is a need for combination therapy and diagnostic approaches to minimize the risks associated with the COVID-19 pandemic effectively.

13.
Environ Pollut ; 308: 119690, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35772620

RESUMO

Rapidly expanding water pollution has transformed into significant dangers around the world. In recent years, the pharmaceutical and agriculture field attained enormous progress to meet the necessities of health and life; however, discharge of trace amounts of pharmaceuticals and pesticides into water significantly have a negative influence on human health and the environment. Contamination with these pollutants also constitutes a great threat to the aquatic ecosystem. To deal with the harmful impacts of such pollutants, their expulsion has attracted researchers' interest a lot, and it became essential to figure out techniques suitable for the removal of these pollutants. Thus, many researchers have devoted their efforts to improving the existing technology or providing an alternative strategy to solve this environmental problem. One of the attractive materials for this purpose is metal-organic frameworks (MOFs) due to their superior high surface area, high porosity, and the tunable features of their structures and function. Among various techniques of wastewater treatment, such as biological treatment, advanced oxidation process and membrane technologies, etc., metal-organic frameworks (MOFs) materials are tailorable porous architectures and are viably used as adsorbents or photocatalysts for wastewater treatment due to their porosity, tunable internal structure, and large surface area. MOFs are synthesized by various methods such as solvo/hydrothermal, sonochemical, microwave and mechanochemical methods. Most common method used for the synthesis of MOFs is solvothermal/hydrothermal methods. Herein, this review aims at providing a comprehensive overview of the latest advances in MOFs and their derivatives, focusing on the following aspects: synthesis and applications. This review comprehensively highlights the application of MOFs and nano-MOFs to remove pharmaceuticals and pesticides from wastewater. For the past years, transition metal-based MOFs have been concentrated as photocatalyst/adsorbents in treating contaminated water. However, work on main group metal-based MOFs is not so abundant. Hence, the foremost objective of this review is to present the latest material and references concerning main group element-based MOFs and nanoscale materials derived from them towards wastewater treatment. It summarizes the possible research challenges and directions for MOFs and their derivatives as catalysts applied to wastewater treatment in the future. With the context of recent pioneering studies on main group elements-based MOFs and their derivatives; we hope to stimulate some possibilities for further development, challenges and future perspectives in this field have been highlighted.


Assuntos
Poluentes Ambientais , Estruturas Metalorgânicas , Praguicidas , Adsorção , Ecossistema , Poluentes Ambientais/química , Humanos , Preparações Farmacêuticas , Águas Residuárias , Água
14.
Environ Pollut ; 308: 119557, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35709916

RESUMO

Incessant release of a large spectrum of agro-industrial pollutants into environmental matrices remains a serious concern due to their potential health risks to humans and aquatic animals. Existing remediation techniques are unable to remove these pollutants, necessitating the development of novel treatment approaches. Due to its unique structure, physicochemical properties, and broad application potential, graphene has attracted a lot of attention as a new type of two-dimensional nanostructure. Given its chemical stability, large surface area, electron mobility, superior thermal conductivity, and two-dimensional structure, tremendous research has been conducted on graphene and its derived composites for environmental remediation and pollution mitigation. Various methods for graphene functionalization have facilitated the development of different graphene derivatives such as graphene oxide (GO), functional reduced graphene oxide (frGO), and reduced graphene oxide (rGO) with novel attributes for multiple applications. This review provides a comprehensive read on the recent progress of multifunctional graphene-based nanocomposites and nanohybrids as a promising way of removing emerging contaminants from aqueous environments. First, a succinct overview of the fundamental structure, fabrication techniques, and features of graphene-based composites is presented. Following that, graphene and GO functionalization, i.e., covalent bonding, non-covalent, and elemental doping, are discussed. Finally, the environmental potentials of a plethora of graphene-based hybrid nanocomposites for the abatement of organic and inorganic contaminants are thoroughly covered.


Assuntos
Poluentes Ambientais , Grafite , Nanocompostos , Purificação da Água , Animais , Grafite/química , Humanos , Nanocompostos/química , Água , Purificação da Água/métodos
15.
Chemosphere ; 306: 135656, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35820475

RESUMO

Inorganic nanoparticles (NPs) have a tunable shape, size, surface morphology, and unique physical properties like catalytic, magnetic, electronic, and optical capabilities. Unlike inorganic nanomaterials, organic polymers exhibit excellent stability, biocompatibility, and processability with a tailored response to external stimuli, including pH, heat, light, and degradation properties. Nano-sized assemblies derived from inorganic and polymeric NPs are combined in a functionalized composite form to import high strength and synergistically promising features not reflected in their part as a single constituent. These new properties of polymer/inorganic functionalized materials have led to emerging applications in a variety of fields, such as environmental remediation, drug delivery, and imaging. This review spotlights recent advances in the design and construction of polymer/inorganic functionalized materials with improved attributes compared to single inorganic and polymeric materials for environmental sustainability. Following an introduction, a comprehensive review of the design and potential applications of polymer/inorganic materials for removing organic pollutants and heavy metals from wastewater is presented. We have offered valuable suggestions for piloting, and scaling-up polymer functionalized nanomaterials using simple concepts. This review is wrapped up with a discussion of perspectives on future research in the field.


Assuntos
Recuperação e Remediação Ambiental , Nanocompostos , Nanopartículas , Sistemas de Liberação de Medicamentos , Nanocompostos/química , Nanopartículas/química , Polímeros/química
16.
Infect Disord Drug Targets ; 21(5): e270421186673, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33023459

RESUMO

The emergence of Severe Acute Respiratory Syndrome (SARS) in named as corona virus disease 19(covid-19) caused by the novel corona virus SARS-CoV-2 has caused hundreds of thousands of mortalities across the world, while the mortality rate is in millions, leading it to be declared as a global pandemic. Numerous research activities are undergoing to reveal the disease and etiological features of covid-19. In this review, some of the interesting aspects of covid-19 are discussed, that include, the origin of the SARS-CoV-2, clinical manifestation, treatment and future aspects of the disease.


Assuntos
COVID-19 , Humanos , Pandemias , SARS-CoV-2
17.
Chemosphere ; 276: 130241, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34088101

RESUMO

At present, environmental contamination has become an emerging issue among researchers. These facts are due to the adverse impacts of an alarming number of recalcitrant contaminants that can affect both humans and animals. There is an urgent need to develop eco-friendly approaches to mitigate the effects of toxic pollutants from the environment. Magnetically responsive composite-based sorbents are very interesting and popular materials for pollutant abatement owing to the high specific surface area, superior adsorption capacity, and magnetic properties, which make their easy separation from sample solution/media. In this review article, we discuss various synthesis approaches, key physicochemical properties, and applications of magnetic composites for pollutant removal. Current gaps for coping with contamination are identified, and a comprehensive outlook in pollutant treatment using magnetic composites is outlined. This study unveils new horizons to researches for better understanding the properties of magnetically-composite-based sorbents and their application in environmental remediation.


Assuntos
Poluentes Ambientais , Recuperação e Remediação Ambiental , Adsorção , Animais , Humanos , Magnetismo
18.
Chemosphere ; 278: 130405, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33823342

RESUMO

The highly robust, effective, and sustainable remediation of hydrocarbon-contaminated wastewater matrices, which is mainly generated from petroleum and related petrochemical industries, is of supreme interest. Owing to the notable presence of suspended solids, oil, and grease, organic matter, highly toxic elements, high salts, and recalcitrant chemicals, crude oil emulsions, and hydrocarbon-contaminated wastewater are considered a potential threat to the environments, animals, plants, and humans. To effectively tackle this challenging issue, magnetic hybrid materials assembled at nano- and micro-scale with unique structural, chemical, and functional entities are considered robust candidates for demulsification purposes. The current research era on magnetic materials has superwettability, leading to an effective system of superwettability, which is vibrant and promising. The wettability of magnetic and magnetic hybrid materials explaining the theme of superhydrophobicity and superhydrophilicity under the liquid. Herein, we reviewed the applications of magnetic nanoparticles (MNPs) as effective demulsifiers. The demulsifier wettability, dose, pH, salinity, and surface morphology of compelling, magnetic nanoparticles are the main hidden factors in effective demulsifiers. There is a comprehensive discussion on the reuse and recyclability of MNPs after oil, water separation. Furthermore, the main challenges, coupled with the magnetic nanoparticles in the effective separation of emulsions, are intensified in detail. This review will compare the current literature and the utilization of MNPs for the demulsification of oil and water emulsions. This is envisioned that the MNPs would be critical in the petroleum and petrochemical industry to effectively eliminate water from a crude oil emulsion.


Assuntos
Poluentes Ambientais , Petróleo , Emulsões , Humanos , Águas Residuárias , Molhabilidade
19.
Adv Mater ; 33(10): e2004207, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33205523

RESUMO

Imprinting vision as memory is a core attribute of human cognitive learning. Fundamental to artificial intelligence systems are bioinspired neuromorphic vision components for the visible and invisible segments of the electromagnetic spectrum. Realization of a single imaging unit with a combination of in-built memory and signal processing capability is imperative to deploy efficient brain-like vision systems. However, the lack of a platform that can be fully controlled by light without the need to apply alternating polarity electric signals has hampered this technological advance. Here, a neuromorphic imaging element based on a fully light-modulated 2D semiconductor in a simple reconfigurable phototransistor structure is presented. This standalone device exhibits inherent characteristics that enable neuromorphic image pre-processing and recognition. Fundamentally, the unique photoresponse induced by oxidation-related defects in 2D black phosphorus (BP) is exploited to achieve visual memory, wavelength-selective multibit programming, and erasing functions, which allow in-pixel image pre-processing. Furthermore, all-optically driven neuromorphic computation is demonstrated by machine learning to classify numbers and recognize images with an accuracy of over 90%. The devices provide a promising approach toward neurorobotics, human-machine interaction technologies, and scalable bionic systems with visual data storage/buffering and processing.

20.
Int J Biol Macromol ; 152: 663-671, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32088221

RESUMO

The latency of toxic cations in the ecosystem poses serious ecological problems due to its bioaccumulation potential and toxicity to living organisms. The effective removal of these wastewater cations releasing from multi-industries is a bottleneck issue. Therefore, an attempt has been made to design a suitable sorbent for cations sorption from the aqueous environment. The chitosan biopolymer was modified with triethylenetetramine to incorporate active sites in the polymeric sequence to boost up its cations sorption capacity. Triethylenetetramine molecule anchoring chitosan (CH-TET) was authenticated through elemental assay, Fourier-transform infrared spectroscopy and 13C NMR in solid-state, scanning electron microscopy and thermal analysis. The sorption of lead (1.94 mmol g-1), copper (2.79 mmol g-1) and nickel (1.53 mmol g-1) was carried out using the functionalized chitosan from aqueous solution, which showed higher sorption capacity for lead and copper than the pristine chitosan in terms of Langmuir sorption isotherm. To scrutinize the mechanism of sorption and energy of interaction between sorbent and sorbate, Langmuir, Temkin, and Freundlich isotherm models were used for sorption study. The Langmuir model showed the best fitting to the results based on lower error function values and a higher correlation coefficient (R2). It can be concluded that the triethylenetetramine-modified chitosan might be considered as an effective sorbent for cations removal from industrial wastewater.


Assuntos
Cátions Bivalentes/química , Quitosana/química , Nanocompostos/química , Adsorção/efeitos dos fármacos , Cobre/química , Descontaminação , Ecossistema , Níquel/química , Trientina , Água/química , Poluentes Químicos da Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA