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1.
Thromb J ; 22(1): 39, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654303

RESUMO

Formyl peptide receptors (FPRs) are members of seven transmembrane G protein-coupled receptors superfamily that exhibit different responses based on the nature of stimulating ligand type. FPRs have been shown to be present in platelets and regulate their function. However, the effect of formyl peptide receptor 2 (FPR2/ALX) lipid ligands on platelets has not yet been addressed. Hence, we sought to study the role of FPR2/ALX ligand and lipoxin A4 lipid analogue, BML-111, in the modulation of platelet function and thrombus formation. Immunofluorescence microscopy showed subcellular distribution and peripheral mobilisation of FPR2/ALX in stimulated platelets. This variation in distribution was further confirmed using flow cytometry. BML-111 inhibited a range of platelet activities in a dose-dependent manner in response to several platelet agonists. This included aggregation, fibrinogen binding to integrin αIIbß3, α-granule secretion, dense granule secretion, Ca2 + mobilisation and integrin αIIbß3-mediated outside-in signaling. The selectivity of BML-111 for FPR2/ALX was confirmed using FPR2/ALX deficient mice in flow cytometry assays. In vitro thrombus formation was also inhibited by various concentrations of BML-111. Moreover, the levels of vasodilator stimulated phosphorylation (VASP-S157) increased significantly after BML-111 treatment in resting and stimulated platelets via protein kinase A (PKA) independently of cyclic adenosine monophosphate (cAMP) signaling. Together, our findings demonstrate the significance of BML-111 as a modulator of platelet function via FPR2/ALX and unravel the thrombo-protective potentials of BML-111 induced signaling against thrombo-inflammatory diseases.

2.
Luminescence ; 39(6): e4801, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38855811

RESUMO

Atopic dermatitis (AD) is a persistent, inflammatory skin condition that impacts approximately 15 to 20% of children and 1 to 3% of adults globally. Common skin manifestations include papules, papulovesicular, and brown or red patches with swelling, crusting, and flaking. Therefore, the drug abrocitinib (ABR) was approved by the US FDA as an oral treatment for atopic dermatitis. The present study outlines the development of innovative, thermostable, and pH-stable organic solvent-free nitrogen-doped carbon dots (N@CQDs) synthesized through a one-step method for evaluating ABR with a notable quantum yield of 33.84% to minimize the use of organic solvents. Their cost-effectiveness, eco-friendly characteristics, and outstanding photocatalytic properties have established them as a promising alternative to conventional luminescent techniques like fluorescent dyes and luminous derivatization technique. The reaction of ABR with N@CQDs led to a significant decrease in the luminescent response of the produced green and stable carbon quantum dots at 513 nm. The detection range was determined to be 1.0-150.0 ng mL-1, with a lower limit of quantitation (LOQ) equal to 0.52 ng mL-1 based on the linear graph. The green method effectively used for analysis of ABR in pharmaceutical tablets and pharmacokinetic study with high sensitivity.


Assuntos
Carbono , Nitrogênio , Pontos Quânticos , Pontos Quânticos/química , Carbono/química , Nitrogênio/química , Humanos , Pirimidinas/química , Pirimidinas/sangue , Pirimidinas/síntese química , Fluorometria , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Solventes/química , Estrutura Molecular
3.
Int J Mol Sci ; 23(23)2022 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-36499631

RESUMO

Autophagy and apoptosis are two important regulatory mechanisms for how the body can respond to diseases. This study was designed to investigate the protective actions of vitamin E (Vit-E) and lactobacillus plantarum (Lac-B) against mercuric chloride (HgCl2)-induced kidney injury. Thirty albino rats were divided into five groups: group 1 served as the normal group; rats in group 2 received high doses of HgCl2; rats in groups 3, 4 and 5 were given Vit-E, Lac-B and the combination of Vit-E and Lac-B, respectively along with HgCl2 for two weeks. HgCl2 provoked renal injury, manifested by elevation in serum urea, urea nitrogen and creatinine. Kidney levels of oxidative stress and inflammation were markedly increased post HgCl2 administration. Moreover, HgCl2 significantly elevated the gene expression levels of VCAM-1 and cystatin C, while podocin was downregulated. Additionally, it markedly decreased the protein expression of Beclin-1 and Bcl-2. Histopathological examination revealed massive degeneration with congested blood vessels following HgCl2 administration. Treatment with Vit-E or/and Lac-B restored the normal levels of the previously mentioned parameters, as well as improved the morphology of kidney tissues. Both Vit-E and Lac-B provided a protective effect against HgCl2-induced kidney damage by regulating autophagy and apoptosis.


Assuntos
Lactobacillus plantarum , Vitamina E , Ratos , Antioxidantes/farmacologia , Apoptose , Autofagia , Proteína Beclina-1/metabolismo , Rim/metabolismo , Lactobacillus plantarum/metabolismo , Cloreto de Mercúrio/toxicidade , Estresse Oxidativo , Ureia/farmacologia , Vitamina E/farmacologia , Vitamina E/metabolismo , Animais
4.
Molecules ; 27(19)2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36234955

RESUMO

By using the chemical bath deposition approach, binary bismuth sulphides (Bi2S3) and chromium-doped ternary bismuth sulphides (Bi2-xCrxS3) thin films were effectively produced, and their potential for photovoltaic applications was examined. Structural elucidation revealed that Bi2S3 deposited by this simple and cost-effective method retained its orthorhombic crystal lattice by doping up to 3 at.%. The morphological analysis confirmed the crack-free deposition, hence making them suitable for solar cell applications. Optical analysis showed that deposited thin films have a bandgap in the range of 1.30 to 1.17 eV, values of refractive index (n) from 2.9 to 1.3, and an extinction coefficient (k) from 1.03 to 0.3. From the Hall measurements, it followed that the dominant carriers in all doped and undoped samples are electrons, and the carrier density in doped samples is almost two orders of magnitude larger than in Bi2S3. Hence, this suggests that doping is an effective tool to improve the optoelectronic behavior of Bi2S3 thin films by engineering the compositional, structural, and morphological properties.

5.
Molecules ; 27(19)2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36235098

RESUMO

Amylase and glucosidase enzymes are the primary harmful source in the development of the chronic condition known as diabetes mellitus. The main function of these enzymes is to break the macromolecules into simple sugar units which are directly involved in the solubility of blood, hence increasing blood glucose levels. To overcome this effect, there is a need for a potent and effective inhibitor that inhibits the conversion of macromolecules of sugar into its smaller units. In this regard, we synthesized thiazolidinone-based indole derivatives (1−20). The synthesized derivatives were evaluated for α-amylase and α-glucosidase inhibitory activity. Different substituted derivatives were found with moderate to good potentials having IC50 values ranging, for α-amylase, from 1.50 ± 0.05 to 29.60 ± 0.40 µM and, for α-glucosidase, from IC50 = 2.40 ± 0.10 to 31.50 ± 0.50 µM. Among the varied substituted compounds, the most active analogs four (1.80 ± 0.70 and 2.70 ± 0.70), five (1.50 ± 0.05 and 2.40 ± 0.10, respectively) of the series showed few folds better inhibitory activity than standard drug acarbose (IC50 = 10.20 ± 0.10 and 11.70 ± 0.10 µM, respectively). Moreover, structure−activity relationship (SAR) was established and binding interactions were analyzed for ligands and proteins (α-amylase and α-glucosidase) through a molecular docking study.


Assuntos
Glucosidases , alfa-Glucosidases , Acarbose , Amilases/metabolismo , Glicemia , Glucosidases/metabolismo , Inibidores de Glicosídeo Hidrolases/química , Indóis/química , Indóis/farmacologia , Ligantes , Simulação de Acoplamento Molecular , Estrutura Molecular , Receptores de Droga , Relação Estrutura-Atividade , alfa-Amilases , alfa-Glucosidases/metabolismo
6.
Molecules ; 27(19)2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36235294

RESUMO

Common methodologies such as liquid-liquid extraction and solid-phase extraction are applied for the extraction of opioids from biological specimens i.e., blood and urine. Techniques including LC-MS/LC-MSMS, GC-MS, etc. are used for qualitative or quantitative determination of opioids. The goal of the present work is to design a green, economic, rugged, and simple extraction technique for famous opioids in human blood and urine and their simultaneous quantification by GC-MS equipped with an inert plus electron impact (EI) ionization source at SIM mode to produce reproducible and efficient results. Morphine, codeine, 6-acetylmorphine, nalbuphine, tramadol and dextromethorphan were selected as target opioids. Anhydrous Epsom salt was applied for dSPE of opioids from blood and urine into acetonitrile extraction solvent with the addition of sodium phosphate buffer (pH 6) and n-hexane was added to remove non-polar interfering species from samples. BSTFA was used as a derivatizing agent for GC-MS. Following method validation, the LOD/LLOQ and ULOQ were determined for morphine, codeine, nal-buphine, tramadol, and dextromethorphan at 10 ng/mL and 1500 ng/mL, respectively, while the LOD/LLOQ and ULOQ were determined for 6-acetylmorphine at 5 ng/mL and 150 ng/mL, respectively. This method was applied to real blood and urine samples of opioid abusers and the results were found to be reproducible with true quantification.


Assuntos
Nalbufina , Tramadol , Acetonitrilas , Analgésicos Opioides , Codeína/análise , Dextrometorfano , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Morfina/análise , Derivados da Morfina/urina , Extração em Fase Sólida/métodos , Solventes , Detecção do Abuso de Substâncias/métodos
7.
Molecules ; 27(21)2022 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-36364195

RESUMO

The current study was conducted to obtain hybrid analogues of indole-based thiadiazole derivatives (1-16) in which a number of reaction steps were involved. To examine their biological activity in the presence of the reference drug Donepezil (0.21 ± 0.12 and 0.30 ± 0.32 M, respectively), the inhibitory potentials of AChE and BuChE were determined for these compounds. Different substituted derivatives showing a varied range of inhibitory profiles, when compared to the reference drug, analogue 8 was shown to have potent activity, with IC50 values for AchE 0.15 ± 0.050 M and BuChE 0.20 ± 0.10, respectively, while other substituted compounds displayed good to moderate potentials. Varied spectroscopic techniques including 1H, 13CNMR and HREI-MS were used to identify the basic skeleton of these compounds. Furthermore, all analogues have a known structure-activity relationship (SAR), and molecular docking investigations have verified the binding interactions of molecule to the active site of enzymes.


Assuntos
Acetilcolinesterase , Tiadiazóis , Acetilcolinesterase/metabolismo , Simulação de Acoplamento Molecular , Inibidores da Colinesterase/química , Tiadiazóis/farmacologia , Tiadiazóis/química , Estrutura Molecular , Relação Estrutura-Atividade , Indóis/farmacologia
8.
Molecules ; 27(20)2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36296515

RESUMO

The disposal of dyes and organic matter into water bodies has become a significant source of pollution, posing health risks to humans worldwide. With rising water demands and dwindling supplies, these harmful compounds must be isolated from wastewater and kept out of the aquatic environment. In the research presented here, hydrothermal synthesis of manganese-doped zinc ferrites' (Mn-ZnFe2O4) nanoparticles (NPs) and their nanocomposites (NCs) with sulfur-doped graphitic carbon nitride (Mn-ZnFe2O4/S-g-C3N4) are described. The samples' morphological, structural, and bonding features were investigated using SEM, XRD, and FTIR techniques. A two-phase photocatalytic degradation study of (0.5, 1, 3, 5, 7, 9, and 11 wt.%) Mn-doped ZnFe2O4 NPs and Mn-ZnFe2O4/(10, 30, 50, 60, and 70 wt.%) S-g-C3N4 NCs against MB was carried out to find the photocatalyst with maximum efficiency. The 9% Mn-ZnFe2O4 NPs and Mn-ZnFe2O4/50% S-g-C3N4 NCs exhibited the best photocatalyst efficiency in phase one and phased two, respectively. The enhanced photocatalytic activity of the Mn-ZnFe2O4/50% S-g-C3N4 NCs could be attributed to synergistic interactions at the Mn-ZnFe2O4/50% S-g-C3N4 NCs interface that resulted in a more effective transfer and separation of photo-induced charges. Therefore, it is efficient, affordable, and ecologically secure to modify ZnFe2O4 by doping with Mn and homogenizing with S-g-C3N4. As a result, our current research suggests that the synthetic ternary hybrid Mn-ZnFe2O4/50% S-g-C3N4 NCs may be an effective photocatalytic system for degrading organic pollutants from wastewater.


Assuntos
Poluentes Ambientais , Águas Residuárias , Humanos , Catálise , Manganês , Corantes , Enxofre , Água , Zinco
9.
Molecules ; 27(20)2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36296569

RESUMO

Tungsten trioxide (WO3) is mainly studied as an electrochromic material and received attention due to N-type oxide-based semiconductors. The magnetic, structural, and optical behavior of pristine WO3 and gadolinium (Gd)-doped WO3 are being investigated using density functional theory. For exchange-correlation potential energy, generalized gradient approximation (GGA+U) is used in our calculations, where U is the Hubbard potential. The estimated bandgap of pure WO3 is 2.5 eV. After the doping of Gd, some states cross the Fermi level, and WO3 acts as a degenerate semiconductor with a 2 eV bandgap. Spin-polarized calculations show that the system is antiferromagnetic in its ground state. The WO3 material is a semiconductor, as there is a bandgap of 2.5 eV between the valence and conduction bands. The Gd-doped WO3's band structure shows few states across the Fermi level, which means that the material is metal or semimetal. After the doping of Gd, WO3 becomes the degenerate semiconductor with a bandgap of 2 eV. The energy difference between ferromagnetic (FM) and antiferromagnetic (AFM) configurations is negative, so the Gd-doped WO3 system is AFM. The pure WO3 is nonmagnetic, where the magnetic moment in the system after doping Gd is 9.5599575 µB.

10.
Molecules ; 27(20)2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36296720

RESUMO

A unique series of sulphonamide derivatives was attempted to be synthesized in this study using a new and effective method. All of the synthesized compounds were verified using several spectroscopic methods, including FTIR, 1H-NMR, 13C-NMR, and HREI-MS, and their binding interactions were studied using molecular docking. The enzymes urease and α-glucosidase were evaluated against each derivative (1-15). When compared to their respective standard drug such as acarbose and thiourea, almost all compounds were shown to have excellent activity. Among the screened series, analogs 5 (IC50 = 3.20 ± 0.40 and 2.10 ± 0.10 µM) and 6 (IC50 = 2.50 ± 0.40 and 5.30 ± 0.20 µM), emerged as potent molecules when compared to the standard drugs acarbose (IC50 = 8.24 ± 0.08 µM) and urease (IC50 = 7.80 ± 0.30). Moreover, an anti-microbial study also demonstrated that analogs 5 and 6 were found with minimum inhibitory concentrations (MICs) in the presence of standard drugs streptomycin and terinafine.


Assuntos
Urease , alfa-Glucosidases , alfa-Glucosidases/metabolismo , Simulação de Acoplamento Molecular , Benzeno , Hidrazinas , Derivados de Benzeno , Acarbose/farmacologia , Relação Estrutura-Atividade , Tioureia/química , Sulfanilamida , Estreptomicina , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Estrutura Molecular , Inibidores de Glicosídeo Hidrolases/farmacologia , Inibidores de Glicosídeo Hidrolases/química
11.
Molecules ; 27(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36431778

RESUMO

In the present work, sulfur-doped manganese ferrites S@Mn(Fe2O4) nanoparticles were prepared by using the sol-gel and citrate method. The concentration of sulfur varied from 1 to 7% by adding Na2S. The samples were characterized by performing Fourier Transformed Infrared Spectroscopy (FTIR), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Ultraviolet-Visible spectroscopy (UV-Visible). The synthesized sulfur-doped manganese ferrites were applied to evaluate the photocatalytic degradation of the dyes. Further, the degradation studies revealed that the nanoparticles successfully degraded the methylene blue dye by adding a 0.006 g dose under the sunlight. The sulfur-doped manganese ferrite nanoparticles containing 3% sulfur completely degraded the dye in 2 h and 15 min in aqueous medium. Thus, the ferrite nanoparticles were found to be promising photocatalyst materials and could be employed for the degradation of other dyes in the future.


Assuntos
Nanopartículas , Luz Solar , Manganês/química , Catálise , Nanopartículas/química , Corantes/química , Cátions , Enxofre
12.
Molecules ; 27(17)2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-36080245

RESUMO

The synthesis of MMT and poly(o-anisidine) (MMT/POA) clay nanocomposites was carried out by using the chemical oxidative polymerization of POA and MMT clay with POA, respectively. By maintaining the constant concentration of POA, different percentage loads of MMT clay were used to determine the effect of MMT clay on the properties of POA. The interaction between POA and MMT clay was investigated by FTIR spectroscopy, and, to reveal the complete compactness and homogeneous distribution of MMT clay in POA, were assessed by using scanning-electron-microscope (SEM) analysis. The UV-visible spectrum was studied for the optical and absorbance properties of MMT/POA ceramic nanocomposites. Furthermore, the horizontal burning test (HBT) demonstrated that clay nanofillers inhibit POA combustion.


Assuntos
Retardadores de Chama , Nanocompostos , Compostos de Anilina , Bentonita/química , Argila , Nanocompostos/química
13.
Sensors (Basel) ; 21(11)2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-34070812

RESUMO

In wireless sensor networks, energy conservation is a critical task. Thus, it is crucial to design an effective MAC protocol that minimizes energy consumption while guaranteeing high network throughput and low delay. In this article, we propose a quorum-based multichannel MAC protocol (QMMAC) for corona-based WSNs. QMMAC utilizes the multichannel communication feature and the quorum concept to greatly increase the throughput while conserving energy. The aim of this protocol is to allow each node and all its forwarders to wake up at the same time while avoiding collision and overhearing by separating their simultaneous communications using the multichannel feature. More precisely, the main idea of QMMAC is twofold. First, QMMAC wakeup scheduling is designed to minimize the end-to-end delay by allowing nodes to wake up at exactly the same time as their potential forwarders, whereas nodes that are not acting as forwarders for each other wake up at a completely different time, and thus overhearing, idle listening and collisions are avoided. Second, channel assignment, which also uses the concept of quorums, is used to share data channels so that there is no conflict or additional packet exchange required to negotiate the availability of channels. Thus, the end-to-end delay is further minimized as well as collisions between conflicting neighbors are avoided. Simulation results indicate that the network performance is improved by QMMAC in terms of energy efficiency, throughput and end-to-end delay.

14.
Int J Biol Macromol ; 254(Pt 2): 127894, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37931864

RESUMO

Organic/Inorganic nanostructures enable the development of new functional materials for optoelectronics and biological applications. In this work, nanocomposite films of polyvinyl pyrrolidone (PVP) and sodium alginate (NaAlg) blend matrix (30/70 wt%) filled with molybdenum trioxide (MoO3) nanoplates were prepared using solution casting procedure. The effect of MoO3 nanoplates on structural, optical, electrical and antibacterial characteristics of pure PVP/NaAlg blend was investigated. The sizes of MoO3 nanoplates had dimensions between 90 and 420 nm with orthorhombic phase as indicated by the TEM and XRD techniques. Also, the XRD patterns of filled films suggested that the presence of crystalline phases of MoO3 within PVP/NaAlg matrix. FTIR analysis revealed the primary vibrational peaks of PVP and NaAlg, whose strength altered randomly after filling. The UV absorption increased gradually and shifted to the higher wavelength side. The alternating current (AC) conductivity and dielectric parameters were improved with increasing MoO3 concentration. The antibacterial activity against Staphylococcus aureus and Escherichia coli increased with increase of MoO3 nanoplates concentration. The filled PVP/NaAlg-MoO3 samples displayed considerable enhancements in the values of Young's modulus (Y), tensile stress (σt) and elongation at break (εB). The obtained results imply that these nanocomposite films can be potentially used in optoelectronics and biological applications.


Assuntos
Nanocompostos , Polímeros , Povidona , Polivinil , Alginatos/química , Antibacterianos/farmacologia , Antibacterianos/química , Nanocompostos/química
15.
SAGE Open Med ; 12: 20503121231221445, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38249941

RESUMO

Objectives: Workplace safety is essential to occupational health practices among healthcare providers, especially for nurses vulnerable to work-related hazards such as needle stick and sharp injuries. In Yemen, the underestimation and absence of reporting system and lack of health supplies in a collapsed health system exacerbated the needle stick and sharp injuries. This study aimed to identify the prevalence and associated factors of needle stick and sharp injuries among nurses in Taiz, Yemen. Methods: A cross-sectional study was conducted on a sample of 151 nurses working in three public hospitals in Taiz City. A semi-structured questionnaire was designed and delivered to the participants. Results: The prevalence of needle stick and sharp injuries among nurses was very high (95.36%), and around half were injured more than five times. Female nurses and those in an emergency department were more likely to be subjected to needle stick and sharp injuries (p = 0.018 and 0.021, respectively). Needle stick was the most common cause of injury (62.77%), and the fingers were the most exposed injury site (79.17%). Non-reporting injuries were very high (73.61%), and only one-third (34.21%) of them proceeded in the process of management, and less than one-quarter (23.68%) had been vaccinated. Conclusion: The prevalence of needle stick and sharp injuries among nurses in Taiz was very high, and determined by gender and place of work. Post-injury reporting and precautions were poor, which may increase the prevalence of hospital-acquired infections among clients and healthcare providers.

16.
J Pharm Bioallied Sci ; 16(Suppl 2): S1863-S1866, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38882828

RESUMO

Carious exposure of an irreversibly inflamed vital pulp in a young permanent tooth presents a significant clinical challenge to clinicians to maintain the vitality. Direct pulp capping, partial pulpotomy, and complete pulpotomy are the available procedures to treat young permanent tooth. Mineral trioxide aggregate and biodentine are currently the material of choice for these procedures. The present case report describes the successful apexogenesis of mandibular left first permanent molar using mineral trioxide aggregate. The 18-month follow-up of the case demonstrated clinical and radiographic success with absence of any signs and symptoms and continued root formation.

17.
Glob Pediatr Health ; 10: 2333794X231203857, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37846399

RESUMO

Objective. This study aims to highlight the low birth weight (LBW) in Taiz City (Yemen), as LBW is one of the public health challenges experiencing a profound effect on newborns. Methods. This was a cross-sectional study since the interview and medical records were the sources of data to be analyzed by SPSS. Results. The findings of this study include; a high prevalence of LBW (39.11%), the maternal age was not associated with LBW (P = .68), and education level, economic status, residence place, and health status were not associated with LBW (P < .05). Although the pre-pregnancy BMI, during-pregnancy BMI, MUAC, and gestational age were significantly associated with LBW (P < .05), the only risk factor was gestational age (OR = 9.606, CI = 3.988-23.135, P = .00). Conclusion. LBW is highly prevalent in Taiz (Yemen), so providing good healthcare services is essential to manage LBW incidence.

18.
Polymers (Basel) ; 15(3)2023 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-36771985

RESUMO

Immobilization of microbial cells for the production of industrially important enzymes has been reported to offer the advantages of recyclability, higher yields and cost effectiveness. The search for an appropriate matrix that is affordable and easy to prepare is a significant topic in microbial biotechnology. Here, an abundant type of agro-industrial waste-corncob-was utilized as an immobilization matrix for the production of xylanase from an indigenous yeast strain, Saccharomyces cerevisiae MK-157. This is the first report describing xylanase production from immobilized S. cerevisiae. To render the corncob matrix more porous, alkaline pretreatment was undertaken and yeast cells were immobilized on the matrix by cultivating at 30 °C for 48 h in Sabouraud dextrose broth. After incubation, the immobilized matrix was transferred to mineral salt medium containing 1% xylan and incubated at 30 °C for 24 h. Xylanase production was determined in cell-free culture supernatant and the matrix was recycled for up to seven cycles. Moreover, xylanase-mediated saccharification was carried out using sugarcane bagasse as a substrate and the release of reducing sugars was monitored. The results showed that the immobilized yeast produced 4.97 IU mL-1 xylanase in the first production cycle, indicating a >tenfold increase compared to the free cells. Xylanase production further increased to its maximum levels (9.23 IU mL-1) in the fourth production cycle. Nonetheless, the cells retained 100% productivity for up to seven cycles. The volumetric and specific productivity of xylanase were also the highest in the fourth cycle. Scanning electron microscopy images revealed the rough surface of the untreated corncob, which became more porous after alkaline pretreatment. Immobilized yeast cells were also visible on the corncob pieces. The saccharification of a natural resource-sugarcane bagasse-using xylanase preparation yielded 26 mg L-1 of reducing sugars. Therefore, it can be concluded that yeast strains can yield sufficient quantities of xylanase, allowing possible biotechnological applications. Moreover, corncob can serve as a cost-effective matrix for industrially important yeast strains.

19.
J Biomol Struct Dyn ; 41(18): 8738-8750, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36300501

RESUMO

Dengue virus has emerged as infectious mosquito borne disease involved in lowering platelets and white blood cells (WBC) count particularly. The genome structure is based on several structural and non-structural proteins essential for viral replication and progeny. One of the major proteins of replication is non-structural protein 3 (NS3) that transforms polyproteins into functional proteins with a cofactor non-structural protein (NS2B). Heat Shock Protein 70 (HSP70), is a human protein that assists in replication, viral entry and virion synthesis. Therefore, to inhibit the spread of dengue infection, there is a need of antivirals targeting replication proteins and other human proteins that help in dengue virus multiplication. By systemic approach based on molecular docking, ADMET (absorption, distribution, metabolism, excretion and toxicity) properties and molecular dynamic simulation (MD), potent inhibitors can be predicted. Inhibition of NS2B/NS3 dengue and HSP70 proteins involved in multiple steps in dengue virus progression can be prevented by using different phytochemicals. Molecular docking was performed using AutoDock Vina, PatchDock, and SwissDock. Interactions of obtained complex were observed in PyMOL and PLIP. Validation was checked by PROCHEK, simulation was performed using iMODS followed by preclinical testing by admetSAR. Ladanein, a flavonoid of Orthosiphon aristatus, was obtained as the lead compound to inhibit major replication protein of dengue virus with inhibitory potential against HSP70 protein. In summary, various in silico approaches were used to obtain the best phytochemical having anti-dengue potential.Communicated by Ramaswamy H. Sarma.

20.
RSC Adv ; 13(20): 13443-13455, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37152558

RESUMO

Catechol is a pollutant that can lead to serious health issues. Identification in aquatic environments is difficult. A highly specific, selective, and sensitive electrochemical biosensor based on a copper-polypyrrole composite and a glassy carbon electrode has been created for catechol detection. The novelty of this newly developed biosensor was tested using electrochemical techniques. The charge and mass transfer functions and partially reversible oxidation kinetics of catechol on the redesigned electrode surface were examined using electrochemical impedance spectroscopy and cyclic voltammetry scan rates. Using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry, the characteristics of sensitivity (8.5699 µA cm-2), LOD (1.52 × 10-7 µM), LOQ (3.52 × 10-5 µM), linear range (0.02-2500 µM), specificity, interference, and real sample detection were investigated. The morphological, structural, and bonding characteristics were investigated using XRD, Raman, FTIR, and SEM. Using an oxidation-reduction technique, a suitable biosensor material was produced. In the presence of interfering compounds, it was shown that it was selective for catechol, like an enzyme.

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