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1.
Molecules ; 29(17)2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39274877

RESUMO

Over the last decades, the increased incidence of metabolic disorders, such as type two diabetes and obesity, has motivated researchers to investigate new enzyme inhibitors. Inhibition of the α-amylase enzyme is one therapeutic approach in lowering glucose levels in the blood to manage diabetes mellitus. The objective of this study was to synthesize short α-/ß-mixed peptides in the solution phase. The Boc-protected α-L-leucine was converted to ß-analogue by using Arndt-Eistert synthesis with the advantage of no racemization and retention of configuration. Three novel short peptides were successfully synthesized: N(Boc)-Gly-ß-Leu-OCH3(14), N(Boc)-O(Bz)α-Ser-ß-Leu-OCH3(16), and N(Boc)-O(Bz)-α-Tyr-α-Gly-ß-Leu-OCH3(17), characterized by FTIR and 1H NMR analysis. The synthesized peptide 16 showed highest inhibitory activity (45.22%) followed by peptide 14 (18.51%) and peptide 17 (17.05%), respectively. Intriguingly, peptide 16 showed higher inhibition on α-amylase compared with other α-/ß-mixed peptides.


Assuntos
Peptídeos , alfa-Amilases , alfa-Amilases/antagonistas & inibidores , Peptídeos/química , Peptídeos/síntese química , Peptídeos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia
2.
Molecules ; 29(4)2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38398517

RESUMO

Obesity is a source of significant pathologies and deadly diseases, including heart disease, diabetes, and cancer. One of the most intriguing strategies in the hunt for new anti-obesity medications is the inhibition of pancreatic lipase (PL). This study presents a novel application of short α and ß-mixed peptides as pancreatic lipase inhibitors. These peptides were synthesized in the solution phase and characterized using FTIR and 1H-NMR. L-proline is present in a high percentage of natural anti-lipase peptides and was used as a ß-amino acid in this study to enhance anti-lipase activity and proteolytic stability. Moreover, L-α-proline was converted to ß-amino acid derivatives using the Arndt-Eistert method with the advantage of stereo control at the α-carbon. The synthesized peptides with anti-lipase activity are N-Boc-ß-Pro-Gly-OBz (93%), N-Boc-O-Bz-Tyr-ß-Pro-ß-Pro-Gly-OBz (92%), N-Boc-O-Bz-Tyr-ß-Pro-COOH (91%), N-Boc-Phe-ß-Pro-OCH3 (90%), and N-Boc-O-Bz-Tyr-ß-Pro-OCH3 (89%). These peptides may function as lead molecules for further modification to more significant molecules, which can help control obesity.


Assuntos
Peptídeos , Prolina , Humanos , Peptídeos/farmacologia , Peptídeos/química , Aminoácidos , Lipase , Obesidade
3.
Faraday Discuss ; 246(0): 11-46, 2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37395363

RESUMO

In many practical applications, ions are the primary charge carrier and must move through either semipermeable membranes or through pores, which mimic ion channels in biological systems. In analogy to electronic devices, the "iontronic" ones use electric fields to induce the charge motion. However, unlike the electrons that move through a conductor, motion of ions is usually associated with simultaneous solvent flow. A study of electroosmotic flow through narrow pores is an outstanding challenge that lies at the interface of non-equilibrium statistical mechanics and fluid dynamics. In this paper, we will review recent works that use dissipative particle dynamics simulations to tackle this difficult problem. We will also present a classical density functional theory (DFT) based on the hypernetted-chain approximation (HNC), which allows us to calculate the velocity of electroosmotic flows inside nanopores containing 1 : 1 or 2 : 1 electrolyte solution. The theoretical results will be compared with simulations. In simulations, the electrostatic interactions are treated using the recently introduced pseudo-1D Ewald summation method. The zeta potentials calculated from the location of the shear plane of a pure solvent are found to agree reasonably well with the Smoluchowski equation. However, the quantitative structure of the fluid velocity profiles deviates significantly from the predictions of the Smoluchowski equation in the case of charged pores with 2 : 1 electrolyte. For low to moderate surface charge densities, the DFT allows us to accurately calculate the electrostatic potential profiles and the zeta potentials inside the nanopores. For pores with 1 : 1 electrolyte, the agreement between theory and simulation is particularly good for large ions, for which steric effects dominate over the ionic electrostatic correlations. The electroosmotic flow is found to depend very strongly on the ionic radii. In the case of pores containing 2 : 1 electrolyte, we observe a reentrant transition in which the electroosmotic flow first reverses and then returns to normal as the surface change density of the pore is increased.

4.
J Chem Phys ; 158(14): 144902, 2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37061472

RESUMO

In this work, we perform molecular dynamics simulations to study a spherical polyelectrolyte brush. We explore the effects of surface polarization and electrostatic coupling on brush size and distribution of counterions. The method of image charges is considered to take into account surface polarization, considering a metallic, an unpolarizable, and a dielectric nano-core. It is observed that, for all cases, a moderate shrinking-swelling effect appears with an increase in the electrostatic coupling parameter. This effect occurs under high Manning ratios. The curves relating the average size of polyelectrolyte brush as a function of coupling show a minimum. The results show that the grafting density of polyelectrolytes on the nano-core surface plays an important role in the polarization effect. We consider a modified Poisson-Boltzmann theory to describe the counterion profiles around the brush in the case of unpolarizable nano-cores and weak electrostatic coupling.

5.
Ecotoxicol Environ Saf ; 208: 111685, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396017

RESUMO

The wastewater utilization for irrigation purposes is common practice in peri-urban areas located in vicinity of developed cities. This water contains elements like chromium (Cr), nickel (Ni), cadmium (Cd) and nitrate (NO3-N) that poses health risk when exposed to human. In this study effect of wastewater irrigation from Chakara wastewater plant, Faisalabad on growth of wheat and health risks was assessed. Pot experiment was conducted at Institute of Soil and Environmental, University of Agriculture, Faisalabad using different concentration of wastewater as treatment 100% tap water, 25% wastewater + 75% tap water, 50% wastewater + 50% tap water, 75% wastewater + 25% tap water, 100% wastewater. The results indicated that the wastewater irrigation negatively effects the plant growth and physiological parameters. The minimum plant height, grain weight, spike length, osmotic potential and SPAD values were recorded 50.33 cm, 1.47 g plant-1, 7.00 cm, 423 and 38.91 respectively in 100% wastewater irrigation. The risk quotient (RQ TEs) for each toxic element and cumulative risk index (RI TEs) values were calculated. The cadmium risk quotient (Cd RQ) for adults was on margin and value was >1 for in 75% wastewater + 25% tap water and 100% wastewater irrigation, while the RQ for Ni and Cr was <1. Maximum RI TEs values calculated in 100% wastewater irrigation 0.424 and 0.294 for children and adults respectively. Hence it was concluded that wastewater irrigation significantly increased the accumulation rate of metals and nitrate in wheat and cause potential health risks for children and adults.


Assuntos
Irrigação Agrícola/métodos , Bioacumulação/efeitos dos fármacos , Metais Pesados/toxicidade , Nitratos/toxicidade , Poluentes do Solo/toxicidade , Triticum/efeitos dos fármacos , Águas Residuárias/química , Adulto , Cádmio/análise , Cádmio/toxicidade , Criança , Cromo/análise , Cromo/toxicidade , Cidades , Grão Comestível/química , Humanos , Metais Pesados/análise , Modelos Teóricos , Níquel/análise , Níquel/toxicidade , Nitratos/análise , Paquistão , Medição de Risco , Solo/química , Poluentes do Solo/análise , Triticum/crescimento & desenvolvimento , Triticum/metabolismo , Águas Residuárias/análise
6.
Chaos Solitons Fractals ; 140: 110232, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32863613

RESUMO

This paper is devoted to investigation of the fractional order fuzzy dynamical system, in our case, modeling the recent pandemic due to corona virus (COVID-19). The considered model is analyzed for exactness and uniqueness of solution by using fixed point theory approach. We have also provided the numerical solution of the nonlinear dynamical system with the help of some iterative method applying Caputo as well as Attangana-Baleanu and Caputo fractional type derivative. Also, random COVID-19 model described by a system of random differential equations was presented. At the end we have given some numerical approximation to illustrate the proposed method by applying different fractional values corresponding to uncertainty.

7.
Molecules ; 25(19)2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003312

RESUMO

Textile dyes and microbial contamination of surface water bodies have been recognized as emerging quality concerns around the globe. The simultaneous resolve of such impurities can pave the route for an amicable technological solution. This study reports the photocatalytic performance and the biocidal potential of nitrogen-doped TiO2 against reactive black 5 (RB5), a double azo dye and E. coli. Molecular docking was performed to identify and quantify the interactions of the TiO2 with ß-lactamase enzyme and to predict the biocidal mechanism. The sol-gel technique was employed for the synthesis of different mol% nitrogen-doped TiO2. The synthesized photocatalysts were characterized using thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) and diffuse reflectance spectroscopy (DRS). The effects of different synthesis and reaction parameters were studied. RB5 dye degradation was monitored by tracking shifts in the absorption spectrum and percent chemical oxygen demand (COD) removal. The best nanomaterial depicted 5.57 nm crystallite size, 49.54 m2 g-1 specific surface area, 11-40 nm particle size with spherical morphologies, and uniform distribution. The RB5 decolorization data fits well with the pseudo-first-order kinetic model, and the maximum monolayer coverage capacity for the Langmuir adsorption model was found to be 40 mg g-1 with Kads of 0.113 mg-1. The LH model yielded a higher coefficient KC (1.15 mg L-1 h-1) compared to the adsorption constant KLH (0.3084 L mg-1). 90% COD removal was achieved in 60 min of irradiation, confirmed by the disappearance of spectral peaks. The best-optimized photocatalysts showed a noticeable biocidal potential against human pathogenic strain E. coli in 150 min. The biocidal mechanism of best-optimized photocatalyst was predicted by molecular docking simulation against E. coli ß-lactamase enzyme. The docking score (-7.6 kcal mol-1) and the binding interaction with the active site residues (Lys315, Thr316, and Glu272) of ß-lactamase further confirmed that inhibition of ß-lactamase could be a most probable mechanism of biocidal activity.


Assuntos
Luz , Simulação de Acoplamento Molecular , Titânio/química , Adsorção , Antibacterianos/farmacologia , Compostos Azo/química , Análise da Demanda Biológica de Oxigênio , Catálise , Cor , Cristalização , Desinfetantes , Concentração de Íons de Hidrogênio , Cinética , Testes de Sensibilidade Microbiana , Nitrogênio/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Difração de Raios X
8.
Drug Dev Ind Pharm ; 45(5): 703-714, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30557053

RESUMO

Emergence of multidrug resistance (MDR) has limited the success of chemotherapeutic agents. Reversal of drugs efflux systems through combination therapy has got wider attention for increasing anticancer drugs efficacy. This study aims at co-encapsulation of Paclitaxel with Naringin in mixed polymeric micelles for enhanced anticancer activity of the drug. Drug-loaded micelles were prepared using two different amphiphilic block co-polymers and were characterized for morphology, size, zeta potential, drug encapsulation, in vitro release and stability using atomic force microscope (AFM), zetasizer, UV spectrophotometer, and FT-IR. MTT assay and fluorescence microscopy were used for in vitro cytotoxicity and cellular uptake studies. Nano-size micelles with spherical morphology and negative charge encapsulated 76.52 ± 0.94% and 32.87 0.61% Paclitaxel and Naringin, respectively. The micelles were thermally stable and retained 87.05 ± 0.69% and 92.88 ± 2.17% Paclitaxel and Naringin upon one-month storage. Maximum drug release was achieved at fourth hour of the study for both the loaded drugs. Paclitaxel co-encapsulation with Naringin synergistically improved its intracellular uptake and 65% in vitro cytotoxicity against breast cancer cells was achieved at its lower dose of 15 µg/mL. Results suggest that co-encapsulation of Paclitaxel with Naringin in mixed micelles is an effective strategy for achieving its higher anticancer activity.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Portadores de Fármacos/síntese química , Flavanonas/administração & dosagem , Neoplasias/tratamento farmacológico , Paclitaxel/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Composição de Medicamentos/métodos , Desenho de Fármacos , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Estabilidade de Medicamentos , Flavanonas/farmacocinética , Humanos , Células MCF-7 , Micelas , Paclitaxel/farmacocinética , Polímeros/síntese química
9.
Int J Mol Sci ; 20(1)2019 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-30609774

RESUMO

Brassinosteroids (BRs) play pivotal roles in modulating plant growth, development, and stress responses. In this study, a Medicago truncatula plant pretreated with brassinolide (BL, the most active BR), enhanced cold stress tolerance by regulating the expression of several cold-related genes and antioxidant enzymes activities. Previous studies reported that hydrogen peroxide (H2O2) and nitric oxide (NO) are involved during environmental stress conditions. However, how these two signaling molecules interact with each other in BRs-induced abiotic stress tolerance remain largely unclear. BL-pretreatment induced, while brassinazole (BRZ, a specific inhibitor of BRs biosynthesis) reduced H2O2 and NO production. Further, application of dimethylthiourea (DMTU, a H2O2 and OH- scavenger) blocked BRs-induced NO production, but BRs-induced H2O2 generation was not sensitive to 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO, a scavenger of NO). Moreover, pretreatment with DMTU and PTIO decreased BL-induced mitochondrial alternative oxidase (AOX) and the photosystem capacity. However, pretreatment with PTIO was found to be more effective than DMTU in reducing BRs-induced increases in Valt, Vt, and MtAOX1 gene expression. Similarly, BRs-induced photosystem II efficiency was found in NO dependent manner than H2O2. Finally, we conclude that H2O2 was involved in NO generation, whereas NO was found to be crucial in BRs-induced AOX capacity, which further contributed to the protection of the photosystem under cold stress conditions in Medicago truncatula.


Assuntos
Brassinosteroides/farmacologia , Resposta ao Choque Frio , Peróxido de Hidrogênio/metabolismo , Medicago truncatula/metabolismo , Óxido Nítrico/metabolismo , Transdução de Sinais , Aclimatação , Óxidos N-Cíclicos/farmacologia , Sequestradores de Radicais Livres/farmacologia , Imidazóis/farmacologia , Medicago truncatula/efeitos dos fármacos , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tioureia/análogos & derivados , Tioureia/farmacologia
10.
Pak J Pharm Sci ; 31(6 (Supplementary): 2697-2708, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30587482

RESUMO

The research was aimed to unravel the enzymatic potential of sequentially transformed new triazoles by chemically converting 4-methoxybenzoic acid via Fischer's esterification to 4-methoxybenzoate which underwent hydrazinolysis and the corresponding hydrazide (1) was cyclized with phenyl isothiocyanate (2) via 2-(4-methoxybenzoyl)-N-phenylhydrazinecarbothioamide (3); an intermediate to 5-(4-methoxyphenyl)-4-phenyl-4H-1,2,4-triazol-3-thiol (4). The electrophiles; alkyl halides 5(a-g) were further reacted with nucleophilic S-atom to attain a series of S-alkylated 5-(4-methoxyphenyl)-4-phenyl-4H-1,2,4-triazole-3-thiols 6(a-g). Characterization of synthesized compounds was accomplished by contemporary spectral techniques such as FT-IR, 1H-NMR, 13C-NMR and EI-MS. Excellent cholinesterase inhibitory potential was portrayed by 3-(n-heptylthio)-5-(4-methoxyphenyl)-4-phenyl-4H-1,2,4-triazole; 6g against AChE (IC50; 38.35±0.62µM) and BChE (IC50; 147.75±0.67µM) enzymes. Eserine (IC50; 0.04±0.01µM) was used as reference standard. Anti-proliferative activity results ascertained that derivative encompassing long straight chain substituted at S-atom of the moiety was the most potent with 4.96 % cell viability (6g) at 25µM and with 2.41% cell viability at 50µMamong library of synthesized derivatives. In silico analysis also substantiated the bioactivity statistics.


Assuntos
Inibidores da Colinesterase/síntese química , Simulação por Computador , Simulação de Acoplamento Molecular/métodos , Compostos de Sulfidrila/síntese química , Triazóis/síntese química , Inibidores da Colinesterase/metabolismo , Células HCT116 , Humanos , Compostos de Sulfidrila/metabolismo , Triazóis/metabolismo
11.
J Asian Nat Prod Res ; 17(8): 838-42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25687532

RESUMO

Royleanumioside (1), a new lupane type triterpenoid, was secluded from the CHCl3 soluble fraction of Teucrium royleanum. The structure of royleanumioside (1) was ascertained by spectral studies including 1D and 2D NMR spectroscopy and by the assessment with the reported data in literature. This new identified compound 1 was further tested for its phytotoxic activity against lettuce seedlings. Interestingly royleanumioside (1) had shown moderate phytotoxic activity.


Assuntos
Citotoxinas/isolamento & purificação , Citotoxinas/farmacologia , Teucrium/química , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Citotoxinas/química , Lactuca/efeitos dos fármacos , Lactuca/crescimento & desenvolvimento , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Paquistão , Triterpenos/química
12.
ScientificWorldJournal ; 2014: 581629, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25025090

RESUMO

One new royleanumoate, a benzene ester (1), has been isolated from T. royleanum Wall. ex Benth along with two known compounds, namely, 3,4-dihydroxymethyl benzoate (2) and oleanolic acid (3). The structure elucidation of the isolated compounds was established on two-dimensional (2D) NMR techniques including heteronuclear multiple bond correlation (HMBC), heteronuclear multiple quantum Coherence (HMQC), and correlation spectroscopy (COSY) experiment.


Assuntos
Ácidos Graxos/química , Fenóis/química , Extratos Vegetais/química , Teucrium/química , Ácidos Graxos/farmacologia , Ácido Oleanólico/química , Fenóis/farmacologia
13.
Chem Asian J ; 19(16): e202301051, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-38216532

RESUMO

Enhanced electrocatalysts that are cost-effective, durable, and derived from abundant resources are imperative for developing efficient and sustainable electrochemical water-splitting systems to produce hydrogen. Therefore, the design and development of non-noble-based catalysts with more environmentally sustainable alternatives in efficient alkaline electrolyzers are important. This work reports ferrocene (Fc)-incorporated nickel sulfide nanostructured electrocatalysts (Fc-NiS) using a one-step facile solvothermal method for water-splitting reactions. Fc-NiS exhibited exceptional electrocatalytic activity under highly alkaline conditions, evident from its peak current density of 345 mA cm-2, surpassing the 153 mA cm-2 achieved by the pristine nickel sulfide (NiS) catalysts. Introducing ferrocene enhances electrical conductivity and facilitates charge transfer during water-splitting reactions, owing to the inclusion of iron metal. Fc-NiS exhibits a very small overpotential of 290 mV at 10 mA cm-2 and a Tafel slope of 50.46 mV dec-1, indicating its superior charge transfer characteristics for the three-electron transfer process involved in water splitting. This outstanding electrocatalytic performance is due to the synergistic effects embedded within the nanoscale architecture of Fc-NiS. Furthermore, the Fc-NiS catalyst also shows a stable response for the water-splitting reactions. It maintains a steady current density with an 87% retention rate for 25 hours of continuous operation, indicating its robustness and potential for prolonged electrolysis processes.

14.
Comput Methods Biomech Biomed Engin ; 26(1): 98-112, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35271386

RESUMO

In the given manuscript, the fractional mathematical model for the current pandemic of COVID-19 is investigated. The model is composed of four agents of susceptible (S), infectious (I), quarantined (Q) and recovered (R) cases respectively. The fractional operator of Atangana-Baleanu-Caputo (ABC) is applied to the considered model for the fractional dynamics. The basic reproduction number is computed for the stability analysis. The techniques of existence and uniqueness of the solution are established with the help of fixed point theory. The concept of stability is also derived using the Ulam-Hyers stability technique. With the help of the fractional order numerical method of Adams-Bashforth, we find the approximate solution of the said model. The obtained scheme is simulated on different fractional orders along with the comparison of integer orders. Varying the numerical values for the contact rate ζ, different simulations are performed to check the effect of it on the dynamics of COVID-19.

15.
Plants (Basel) ; 12(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36616342

RESUMO

Phaseolus vulgaris L. is the major pulse cultivated and culturally inculcated in the food habits of the locals in the Himalayan mountainous region of Azad Jammu and Kashmir (AJK), Pakistan. The current study was designed to investigate the role of P. vulgaris cultivation in providing livelihood support and to evaluate its production and consumption patterns correlated with the household variables in the state of AJK. The socio-economic data was collected from nine bean cultivated areas in six districts of AJK. The data was acquired by administrating a total of 522 detailed semi structured questionnaires from a diverse array of the respondents following the snowball technique focusing on yield, consumption, revenue generation and livelihood support provided by bean cultivation. The results revealed that common bean cultivation provided significant livelihood support to the local mountainous populations with an average annual income of 50.80 $/family. Subsequently, bean production contributed an average annual per capita income of 6.81 $ in the area, which was attributed to the large family size. Local populations showed an average bean production of 33.93 kg/family, whereas the average annual bean consumption was recorded as 31.99 kg/family in the region. Bean crops were recorded to have an average price of $1.49/kg, with significant variations in the study area correlated with local yield. A data analysis indicated a strong correlation in bean production and consumption patterns. Common bean farmers had a very small farm size, averaging 0.24 ha, where 100% of farmers cultivated common beans as an intercrop with Maize as the primary crop. A Pearson's test (p value < 0.05) revealed significant correlations between land holding and bean production as well as consumption, and bean production with annual per capita income. Small farm size, declining soil fertility, low bean pricing and the unavailability of market mechanisms were identified as the major challenges faced by the common bean farmers. It is recommended to employ an integrated bean farming approach to enhance the economic impact of common bean cultivation in the socioeconomic appraisal of the local populations.

16.
Artigo em Inglês | MEDLINE | ID: mdl-37504956

RESUMO

The developed article considers SIR problems for the recent COVID-19 pandemic, in which each component is divided into two subgroups: young and adults. These subgroups are distributed among two classes in each compartment, and the effect of COVID-19 is observed in each class. The fractional problem is investigated using the non-singular operator of Atangana Baleanu in the Caputo sense (ABC). The existence and uniqueness of the solution are calculated using the fundamental theorems of fixed point theory. The stability development is also determined using the Ulam-Hyers stability technique. The approximate solution is evaluated using the fractional Adams-Bashforth technique, providing a wide range of choices for selecting fractional order parameters. The simulation is plotted against available data to verify the obtained scheme. Different fractional-order approximations are compared to integer-order curves of various orders. Therefore, this analysis represents the recent COVID-19 pandemic, differentiated by age at different fractional orders. The analysis reveals the impact of COVID-19 on young and adult populations. Adults, who typically have weaker immune systems, are more susceptible to infection compared to young people. Similarly, recovery from infection is higher among young infected individuals compared to infected cases in adults.

17.
Environ Sci Pollut Res Int ; 30(60): 124992-125005, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37498427

RESUMO

Graphene quantum dots (GQDs), a new solid-state electron transfer material was anchored to nitrogen-doped TiO2 via sol gel method. The introduction of GQDs effectively extended light absorption of TiO2 from UV to visible region. GQD-N-TiO2 demonstrated lower PL intensity at excitation wavelengths of 320 to 450 nm confirming enhanced exciton lifespan. GQD-N-TiO2-300 revealed higher surface area (191.91m2 g-1), pore diameter (1.94 nm), TEM particle size distribution (4.88 ± 1.26 nm) with lattice spacing of 0.45 nm and bandgap (2.91 eV). In addition, GQDs incorporation shifted XPS spectrum of Ti 2p to lower binding energy level (458.36 eV), while substitution of oxygen sites in TiO2 lattice by carbon were confirmed through deconvolution of C 1 s spectrum. Photocatalytic reaction followed the pseudo first order reaction and continuous reductions in apparent rate constant (Kapp) with incremental increase in RB5 concentration. Langmuir-Hinshelwood model showed surface reaction rate constants KC = 1.95 mg L-1 min-1 and KLH = 0.76 L mg-1. The active species trapping, and mechanism studies indicated the photocatalytic decolorization of RB5 through GQD-N-TiO2 was governed by type II heterojunction. Overall, the photodecolorization reactions were triggered by the formation of holes and reactive oxygen species. The presence of •OH, 1O2, and O2• during the photocatalytic process were confirmed through EPR analysis. The excellent photocatalytic decolorization of the synthesized nanocomposite against RB5 can be ascribed to the presence of GQDs in the TiO2 lattice that acted as excellent electron transporter and photosensitizer. This study provides a basis for using nonmetal, abundant, and benign materials like graphene quantum dots to enhance the TiO2 photocatalytic efficiency, opening new possibilities for environmental applications.


Assuntos
Grafite , Pontos Quânticos , Luz , Nitrogênio
18.
Plants (Basel) ; 12(13)2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37447099

RESUMO

Nomenclatural types for twenty-nine names belonging to the genus Asparagus are typified and discussed. The following names are lectotypified: A. altiscandens Engl. & Gilg, A. altissimus Munby, A. baumii Engl. & Gilg, A. benguellensis Baker, A. burchellii Baker, A. curillus Buch.-Ham. ex Roxb., A. deflexus Baker, A. duchesnei L.Linden, A. equisetoides Welw. ex Baker, A. fasciculatus Thunb., A. griffithii, Baker, A. homblei De Wild., A. kaessneri De Wild., A. lecardii De Wild., A. longicladus N.E.Br., A. longiflorus Franch., A. monophyllus Baker, A. palaestinus Baker, A. pastorianus Webb & Berthel., A. persicus Baker, A. poissonii H.Perrier, A. psilurus Welw. ex Baker, A. ritschardii De Wild., A. sapinii De Wild., A. scandens Thunb., A. schumanianus Schltr. ex H.Perrier, A. stellatus Baker, A. subfalcatus De Wild., and A. undulatus (L.f.) Thunb. (synonym of Dracaena undulata L.f.). A new name, Asparagus neofasciculatus, is proposed as a replacement name for A. fasciculatus Thunb., which is an illegitimate later homonym of A. fasciculatus R.Br. The original protologue of these names and the original materials are evaluated. Nomenclature remarks discussing the selection of type specimens are given for each name, and known isotypes or isolectotypes are also cited. This information could be utilized as a reference for future taxonomic and systematic studies on Asparagus around the world.

19.
Int J Mol Sci ; 13(2): 2472-2480, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22408465

RESUMO

Phenolic compounds were extracted from the fruits of Morus nigra and Morus alba using methanol and acetone. The sugar-free extracts (SFEs) were prepared using Amberlite XAD-16 column chromatography. All of the SFEs exhibited antioxidant potential as determined by ABTS (0.75-1.25 mmol Trolox/g), DPPH (2,2-diphenyl-1-picrylhydrazyl) (EC(50) from 48 µg/mL to 79 µg/mL), and reducing power assays. However, a stronger activity was noted for the SFEs obtained from Morus nigra fruits. These extracts also possessed the highest contents of total phenolics: 164 mg/g (methanolic SFE) and 173 mg/g (acetonic SFE). The presence of phenolic acids and flavonoids in the extracts was confirmed using HPLC method and chlorogenic acid and rutin were found as the dominant phenolic constituents in the SFEs.


Assuntos
Antioxidantes/farmacologia , Frutas/química , Morus/química , Extratos Vegetais/farmacologia , Acetona/farmacologia , Antioxidantes/química , Hidroxibenzoatos/farmacologia , Metanol/farmacologia , Oxirredução/efeitos dos fármacos , Fenóis/farmacologia , Extratos Vegetais/química , Espectrofotometria Ultravioleta
20.
Environ Sci Pollut Res Int ; 29(32): 48869-48879, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35199269

RESUMO

Exploring extractable phytochemicals from locally adapted sisal plant vegetation vary seasonally at different locations. This study elaborated proximate composition and phytochemical heterogeneity in sisal due to varying environmental conditions analyzed from five districts, i.e., Chakwal, Khushab, Rawalpindi, Faisalabad, and Layyah in Punjab, Pakistan. Extensive surveying and plant sampling across 2 years 2017-2018 and 2018-2019, during mid-spring, summer, autumn, and winter seasons were carried out for understanding the seasonal impact on sisal. The present study was designed in a randomized complete block design (RCBD) and analyzed considering seasonal, yearly, and locational impact. The spatial differences in phytochemicals concentration were strongly associated with environmental conditions prevailing in different seasons. Autumn season reflected saponins, tannins, and flavonoids in higher concentrations during 2018-2019 while steroids and terpenoids were higher during spring 2018-2019. Spatio-temporal variations in the proximate analysis were more apparent in different samples collected from different districts. Data recorded for the Khushab district and autumn season reflected the higher composition of a proximate analysis and phytochemical contents as compared to other seasons. Overall, the spatial differences in phytochemicals concentration were strongly associated with soils and environmental conditions prevailing in different seasons in selected districts.


Assuntos
Agave , Agave/química , Paquistão , Compostos Fitoquímicos , Estações do Ano , Solo
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