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1.
Pharmazie ; 79(3): 42-48, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38872274

RESUMO

Silver nanoparticles (AgNPs), owing to their unusual characteristics, have been used in various pharmaceutical, cosmetic, and healthcare products. AgNPs, with their exceptional biological potential, exhibit antibacterial, antifungal, antiviral, anti-inflammatory, anticancer, and wound healing properties and have been extensively used in burn therapy. Several studies have established the use of silver nanoparticles in the treatment of burn injuries, resulting in reduced inflammation, quick tissue regeneration, and the remarkable creation of collagen fibers. Conventional physical and chemical techniques have synthesized AgNPs, but they appear to be highly costly and hazardous. Recently, there has been considerable interest in the synthesis of AgNPs using the green chemistry approach because of its tremendous benefits, including being non-toxic, low energy consumption, pollution-free, economical, environmentally friendly, and more sustainable. This review emphasizes the green synthesis of AgNPs using bacteria, fungi, plants, and other microorganisms and the current research related to the application of green synthesized AgNPs in burn therapy, including the biological aspects of AgNPs, their mode of action, and any possible detrimental effects.


Assuntos
Queimaduras , Química Verde , Nanopartículas Metálicas , Prata , Queimaduras/tratamento farmacológico , Prata/química , Prata/farmacologia , Nanopartículas Metálicas/química , Química Verde/métodos , Humanos , Animais , Cicatrização/efeitos dos fármacos , Anti-Infecciosos/farmacologia
2.
Inorg Chem ; 62(39): 16101-16113, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37721399

RESUMO

In this study, we report the synthesis and characterization of some heteroleptic Cr(III) complexes of the form [Cr(Phen)2L](OTf)3, where Phen = 1,10-phenanthroline and L is either 2,2'-bipyridine (bpy) or its derivatives, such as 4,4'-dimethyl-2,2'-bipyridine (4,4'-DMB), 4,4'-dimethoxy-2,2'-bipyridine (4,4'-DMOB), 4,4'-ditert-butyl-2,2'-bipyridine (4,4'-dtbpy), 5,5'-dimethyl-2,2'-bipyridine (5,5'-DMB), 4,4'-dimethoxycarbonyl-2,2'-bipyridine (4,4'-dmcbpy) or 1,10-phenanthroline derivatives, such as 5-methyl-1,10-phenanthroline (5-Me-Phen) and 4,7-dimethyl-1,10-phenanthroline (4,7-DMP). Heteroleptic complexes were prepared in two stages via the intermediate [Cr(Phen)2(CF3SO3)2](CF3SO3) and five examples have been crystallographically characterized. Steady-state absorption and luminescence emission characteristics of these complexes were measured in 1 M HCl solutions. The luminescence quantum yield of these complexes was found to be the lowest for [Cr(Phen)2(4,4'-dmcbpy)](OTf)3 and the highest for [Cr(Phen)2(4,4'-DMB)](OTf)3 with values of 0.31 × 10-2 and 1.48 × 10-2, respectively. The calculated excited state energy, E0-0, was found to vary within the narrow range of 163.1-165.0 kJ mol-1 across the series. Transient absorption spectra in degassed, air-equilibrated, and oxygen-saturated 1 M HCl aqueous solutions were also measured at different time decays and demonstrated no significant differences, indicating the absence of any ion-separated species in the excited state. Excited-state decay traces at the wavelength of maximum absorption were used to calculate oxygen quenching rate constants, kq, which were found to be in the range 3.26-5.27 × 107 M-1 s-1. Singlet oxygen luminescence photosensitized by these complexes was observed in D2O, and its luminescence intensity at 1270 nm was used for the determination of singlet oxygen quantum yields for these complexes, which were in the range of 0.20-0.44, while the fraction of the excited 2E state quenched by oxygen was in the range of 0.22-0.68, and the efficiency of singlet oxygen production was in the range of 0.44-0.90. The mechanism by which the excited 2E state is quenched by oxygen is explained by a spin statistical model that predicts the balance between charge transfer and noncharge transfer deactivation pathways, which was represented by the parameter pCT that was found to vary from 0.35 to 0.68 for this series of Cr(III) complexes.

3.
J Enzyme Inhib Med Chem ; 38(1): 330-342, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36444862

RESUMO

New spiro-piperidine derivatives were synthesised via the eco-friendly ionic liquids in a one-pot fashion. The in vitro antileishmanial activity against Leishmania major promastigote and amastigote forms highlighted promising antileishmanial activity for most of the derivatives, with superior activity compared to miltefosine. The most active compounds 8a and 9a exhibited sub-micromolar range of activity, with IC50 values of 0.89 µM and 0.50 µM, respectively, compared to 8.08 µM of miltefosine. Furthermore, the antileishmanial activity reversal of these compounds via folic and folinic acids displayed comparable results to the positive control trimethoprim. This emphasises that their antileishmanial activity is through the antifolate mechanism via targeting DHFR and PTR1. The most active compounds showed superior selectivity and safety profile compared to miltefosine against VERO cells. Moreover, the docking experiments of 8a and 9a against Lm-PTR1 rationalised the observed in vitro activities. Molecular dynamics simulations confirmed a stable and high potential binding to Lm-PTR1.


Assuntos
Antiprotozoários , Chlorocebus aethiops , Animais , Células Vero , Antiprotozoários/farmacologia , Fosforilcolina , Piperidinas/farmacologia
5.
Molecules ; 28(9)2023 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-37175349

RESUMO

Tephorosia purpurea subsp. apollinea was extracted with methanol and n-hexane to obtain sub-fractions. The chemical compounds identified with GC-MS and HPLC in T. purpurea subsp. apollinea extracts showed antioxidant and anticancer properties. The antioxidant and anticancer activities were investigated using DDPH and ABTS assays, and MTT assay, respectively. Stigmasta-5,24(28)-dien-3-ol, (3 ß,24Z)-, 9,12,15-octadecatrienoic acid methyl ester, phytol, chlorogenic acid, and quercetin were the major chemical compounds detected in T. purpurea subsp. apollinea. These compounds possessed antioxidant and anticancer properties. The methanol extract showed antioxidant properties with DDPH and ABTS radical scavenging of 84% and 94%, respectively, relative to ascorbic acid and trolox. The anticancer effects of T. purpurea subsp. apollinea against the cancer cell lines MCF7 (IC50 = 102.8 ± 0.6 µg/mL), MG63 (IC50 = 118.3 ± 2.5 µg/mL), T47D (IC50 = 114.7 ± 1.0 µg/mL), HeLa (IC50 = 196.3 ± 2.3 µg/mL), and PC3 (IC50 = 117.7 ± 1.1 µg/mL) were greater than its anticancer effects against U379 (IC50 = 248.4 ± 7.5 µg/mL). However, it had no adverse effects on the normal cells (WI38) (IC50 = 242.9 ± 1.8 µg/mL). Therefore, the major active constituents presented in T. purpurea subsp. apollinea can be isolated and studied for their potential antioxidant and anticancer effects against breast, cervical, and prostate cancers and osteosarcoma.


Assuntos
Antioxidantes , Tephrosia , Masculino , Humanos , Antioxidantes/farmacologia , Antioxidantes/análise , Tephrosia/química , Metanol , Extratos Vegetais/química , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/análise , Células HeLa
6.
Molecules ; 28(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36677687

RESUMO

Anti-tumor compounds from natural products are being investigated as possible alternatives for cancer chemotherapeutics that have serious adverse effects and tumor resistance. Calystegia silvatica was collected from the north coast of Egypt and extracted via methanol and n-hexane sub-fraction. The biologically active compounds of Calystegia silvatica were identified from the methanol and n-hexane extracts from the leaves and stems of the plant using GC-MS and HPLC. The antitumor properties of both parts of the plant were investigated against cancer and non-cancer cell lines using the MTT assay, and the IC50 in comparison to doxorubicin was calculated. The main compounds identified in the methanol extract were cis-vaccenic acid and trans-13-octadecenoic acid in the leaves and stems, respectively, and phenyl undecane and 3,7,11,15 tetramethyl-2-hexadeca-1-ol in the n-hexane extracts of the leaves and stems, respectively. Both parts of the plant contained fatty acids that have potential antitumor properties. The methanol extract from the stems of C. silvatica showed antitumor properties against HeLa, with an IC50 of 114 ± 5 µg/mL, PC3 with an IC50 of 137 ± 18 µg/mL and MCF7 with an IC50 of 172 ± 15 µg/mL, which were greater than Caco2, which had an IC50 of 353 ± 19 µg/mL, and HepG2, which had an IC50 of 236 ± 17 µg/mL. However, the leaf extract showed weak antitumor properties against all of the studied cancer cell lines (HeLa with an IC50 of 208 ± 13 µg/mL, PC3 with an IC50 of 336 ± 57 µg/mL, MCF7 with an IC50 of 324 ± 17 µg/mL, Caco2 with an IC50 of 682 ± 55 µg/mL and HepG2 with an IC50 of 593 ± 22 µg/mL). Neither part of the plant extract showed any cytotoxicity to the normal cells (WI38). Therefore, C. silvatica stems may potentially be used for the treatment of cervical, prostate and breast cancer.


Assuntos
Calystegia , Humanos , Metanol , Células CACO-2 , Extratos Vegetais/química , Compostos Fitoquímicos/farmacologia , Folhas de Planta/química
7.
Bioorg Chem ; 129: 106143, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36191430

RESUMO

Three series of novel 1-aryl-3-(4-methylsulfonylphenyl) pyrazole derivatives were synthesized, characterized by several spectroscopic techniques, and investigated as potential anti-inflammatory and anticancer agents. The biological evaluation showed that almost all the synthesized compounds have significant potency and selectivity for the COX-2 enzyme over COX-1 with noticeable anti-inflammatory activity compared to celecoxib and indomethacin. Accordingly, compounds 8a, 8b, 8e, 8j, 8l, 9a, 9b, 9c, and 10b showed the best COX-2 inhibition (IC50 ranged from 0.059 to 0.079 µM) with good anti-inflammatory activity (% of edema inhibition ranged from 87.9 to 67.5). Moreover, compound 8b possessed the highest selectivity index regarding COX-2 isozyme (SI = 211) in comparison to celecoxib (SI = 312) with good in vivo anti-inflammatory activity (% edema inhibition = 77.70 after 5 h). Also, compounds 8a, 8b, 8j, 8l, and 9a showed ulcerogenic liability and histopathological changes close to celecoxib. Molecular docking and dynamics simulations were also conducted to illustrate the binding modes inside the COX-2 active site. Furthermore, all compounds were screened against three cancer cell line panels to determine their antiproliferative properties by MTT assay. Compounds 8a, 8b, and 8e along with their cyclized forms 9a, 9b, and 9c exhibited a considerable antiproliferative effect on liver (IC50: 6.81-19.71 µM), colon (IC50: 7.64-15.34 µM), and breast (IC50: 6.77-18.41 µM) cancer cell lines. More importantly, compounds 8a, 8e, 9a, and 9b were found to be safe on normal HEK-293T kidney cells in comparison to cancer. cells, especially compound 8e with IC50 value of 66.45 µM. Mechanistic studies demonstrated the apoptotic activity of the most active compounds 8a, 8e, 9a, and 9b on MCF-7 cancer cells by inducing a strong S phase cell cycle arrest suggesting that the mechanism of its antiproliferative activity may be through COX-2 inhibition. Finally, the hit compounds 8a, 8b and 9a were discovered to have selective COX-2 inhibitory activity and good anti-inflammatory activity with minimal ulcerogenic effect as well as potent anticancer activity.


Assuntos
Antineoplásicos , Inibidores de Ciclo-Oxigenase 2 , Humanos , Ciclo-Oxigenase 2/metabolismo , Simulação de Acoplamento Molecular , Celecoxib/uso terapêutico , Anti-Inflamatórios/química , Edema/induzido quimicamente , Edema/tratamento farmacológico , Estrutura Molecular , Relação Estrutura-Atividade
8.
Mol Divers ; 26(3): 1743-1759, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34455532

RESUMO

A series of ciprofloxacin/thiazolidine-2,4-dione hybrids 3a-m were prepared and identified by IR, 1HNMR, 13CNMR and elemental analysis. The antibacterial activity results of the designed hybrids revealed a shift of spectrum toward Gram-positive bacteria. They exhibited excellent activity against S. aureus ATCC 6538, with the most potent compounds being 3a, 3e, 3g, 3i, 3k, 3l and 3m possessing MICs of 0.02, 2.03, 0.64, 0.35, 1.04, 0.22 and 0.36 µM, respectively, compared to their parent compound ciprofloxacin (MIC: 5.49 µM). They also showed interesting activity against MRSA AUMC 261 with 3a, 3e and 3l showing MIC values of 5 nM. Reduced activity was observed against Gram-negative bacteria with compound 3l exhibiting a slightly higher activity against K. pneumoniae ATCC10031 with a MIC value of 0. 08 µM. Mechanistically, the incorporation of thiazolidine-2,4-dione ring into ciprofloxacin retained its ability to inhibit DNA synthesis via inhibiting both topoisomerase IV and DNA gyrase of S. aureus. Compounds 3a, 3l and 3m were more potent than ciprofloxacin for topoisomerase IV (IC50 = 0.3-1.9 µM) and gyrase (IC50 = 0.22-0.31 µM) inhibition, which coincide with their antibacterial activity against S. aureus ATCC 6538. Docking against DNA gyrase active site confirmed the ability of the tested compounds to form stable complexes with the enzyme; like that of ciprofloxacin, 3a, 3i, 3k, 3m and 3l reconsidered promising broad-spectrum antibacterial agents targeting topoisomerase IV and gyrase enzymes and have good activity against MRSA.


Assuntos
Ciprofloxacina , Staphylococcus aureus Resistente à Meticilina , Antibacterianos/química , Antibacterianos/farmacologia , Ciprofloxacina/química , Ciprofloxacina/farmacologia , DNA Girase/metabolismo , DNA Topoisomerase IV , Staphylococcus aureus Resistente à Meticilina/metabolismo , Testes de Sensibilidade Microbiana , Staphylococcus aureus , Tiazolidinedionas , Tiazolidinas , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/farmacologia
9.
Sensors (Basel) ; 22(15)2022 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-35957295

RESUMO

This study presents an effective artificial neural network (ANN) approach to combine measurements from inertial measurement units (IMUs) and time-of-flight (TOF) measurements from an ultra-wideband (UWB) system with OptiTrack Motion Capture System (OptiT-MCS) data to guarantee the positioning accuracy of motion tracking in indoor environments. The proposed fusion approach unifies the following advantages of both technologies: high data rates from the MCS, and global translational precision from the inertial measurement unit (IMU)/UWB localization system. Consequently, it leads to accurate position estimates when compared with data from the IMU/UWB system relative to the OptiT-MCS reference system. The calibrations of the positioning IMU/UWB and MCS systems are utilized in real-time movement with a diverse set of motion recordings using a mobile robot. The proposed neural network (NN) approach experimentally revealed accurate position estimates, giving an enhancement average mean absolute percentage error (MAPE) of 17.56% and 7.48% in the X and Y coordinates, respectively, and the coefficient of correlation R greater than 99%. Moreover, the experimental results prove that the proposed NN fusion is capable of maintaining high accuracy in position estimates while preventing drift errors from increasing in an unbounded manner, implying that the proposed approach is more effective than the compared approaches.


Assuntos
Robótica , Algoritmos , Movimento (Física) , Movimento , Redes Neurais de Computação
10.
Molecules ; 26(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34443314

RESUMO

Despite the common use of salens and hydroxyquinolines as therapeutic and bioactive agents, their metal complexes are still under development. Here, we report the synthesis of novel mixed-ligand metal complexes (MSQ) comprising salen (S), derived from (2,2'-{1,2-ethanediylbis[nitrilo(E) methylylidene]}diphenol, and 8-hydroxyquinoline (Q) with Co(II), Ni(II), Cd(II), Al(III), and La(III). The structures and properties of these MSQ metal complexes were investigated using molar conductivity, melting point, FTIR, 1H NMR, 13C NMR, UV-VIS, mass spectra, and thermal analysis. Quantum calculation, analytical, and experimental measurements seem to suggest the proposed structure of the compounds and its uncommon monobasic tridentate binding mode of salen via phenolic oxygen, azomethine group, and the NH group. The general molecular formula of MSQ metal complexes is [M(S)(Q)(H2O)] for M (II) = Co, Ni, and Cd or [M(S)(Q)(Cl)] and [M(S)(Q)(H2O)]Cl for M(III) = La and Al, respectively. Importantly, all prepared metal complexes were evaluated for their antimicrobial and anticancer activities. The metal complexes exhibited high cytotoxic potency against human breast cancer (MDA-MB231) and liver cancer (Hep-G2) cell lines. Among all MSQ metal complexes, CoSQ and LaSQ produced IC50 values (1.49 and 1.95 µM, respectively) that were comparable to that of cisplatin (1.55 µM) against Hep-G2 cells, whereas CdSQ and LaSQ had best potency against MDA-MB231 with IC50 values of 1.95 and 1.43 µM, respectively. Furthermore, the metal complexes exhibited significant antimicrobial activities against a wide spectrum of both Gram-positive and -negative bacterial and fungal strains. The antibacterial and antifungal efficacies for the MSQ metal complexes, the free S and Q ligands, and the standard drugs gentamycin and ketoconazole decreased in the order AlSQ > LaSQ > CdSQ > gentamycin > NiSQ > CoSQ > Q > S for antibacterial activity, and for antifungal activity followed the trend of LaSQ > AlSQ > CdSQ > ketoconazole > NiSQ > CoSQ > Q > S. Molecular docking studies were performed to investigate the binding of the synthesized compounds with breast cancer oxidoreductase (PDB ID: 3HB5). According to the data obtained, the most probable coordination geometry is octahedral for all the metal complexes. The molecular and electronic structures of the metal complexes were optimized theoretically, and their quantum chemical parameters were calculated. PXRD results for the Cd(II) and La(III) metal complexes indicated that they were crystalline in nature.


Assuntos
Antibacterianos/farmacologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Teoria da Densidade Funcional , Etilenodiaminas/síntese química , Simulação de Acoplamento Molecular , Oxiquinolina/síntese química , Oxiquinolina/farmacologia , Antibacterianos/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/química , Etilenodiaminas/química , Etilenodiaminas/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Ligantes , Testes de Sensibilidade Microbiana , Conformação Molecular , Oxiquinolina/química , Difração de Pó , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
11.
Small ; 15(46): e1903025, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31573772

RESUMO

The predicted quasiparticle energy gap of more than 1 eV in sub-6 nm graphene nanoribbons (GNRs) is elusive, as it is strongly suppressed by the substrate dielectric screening. The number of techniques that can produce suspended high-quality and electrically contacted GNRs is small. The helium ion beam milling technique is capable of achieving sub-5 nm patterning; however, the functional device fabrication and the electrical characteristics are not yet reported. Here, the electrical transport measurement of suspended ≈6 nm wide mono- and bilayer GNR functional devices is reported, which are obtained through sub-nanometer resolution helium ion beam milling with controlled total helium ion budget. The transport gap opening of 0.16-0.8 eV is observed at room temperature. The measured transport gap of the different edge orientated GNRs is in good agreement with first-principles simulation results. The enhanced electron-electron interaction and reduced dielectric screening in the suspended quasi-1D GNRs and anti-ferromagnetic coupling between opposite edges in the zigzag GNRs substantiate the observed large transport gap.

12.
Toxicol Appl Pharmacol ; 369: 39-48, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30768973

RESUMO

The occurrence of drug hypersensitivity reactions (DHRs) following administration of low molecular weight (LMW) drugs is an important health concern. However, in vivo animal models which could be used as tools for the prediction of DHRs are lacking. As a result, research has focused on development of in vitro tools for predicting DHRs. In this study a novel human in vitro pre-clinical skin explant test was used to predict T cell-mediated hypersensitivity responses induced by LMW drugs. Responses in the skin explant test for 12 LMW drugs associated with T cell-mediated hypersensitivity in the clinic (abacavir, amoxicillin, carbamazepine, diclofenac, lamotrigine, lapatinib, lumiracoxib, nevirapine, ofloxacin, phenytoin, propranolol, sulfamethoxazole) were compared with responses for 5 drugs with few/no reports of T cell-mediated hypersensitivity reactions (acetaminophen, cimetidine, flecainide, metformin, verapamil). Changes in skin histology following in vitro exposure to the drugs as well as T cell proliferation and interferon gamma (IFNγ) production were studied. The results of the skin explant assays showed a good positive correlation (r = 0.77, p < .001) between the test outcome (prediction of positive or negative) and the clinical classification of the tested drugs. The T cell proliferation assay showed a correlation of r = 0.60 (p < .01) and the IFNγ assay r = 0.51 (p < .04). The data suggest that the skin explant model could be a useful tool to predict the potential of LMW drugs to induce DHRs.


Assuntos
Hipersensibilidade a Drogas/etiologia , Irritantes/toxicidade , Testes de Irritação da Pele/métodos , Pele/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Hipersensibilidade a Drogas/imunologia , Hipersensibilidade a Drogas/metabolismo , Hipersensibilidade a Drogas/patologia , Humanos , Interferon gama/metabolismo , Ativação Linfocitária , Peso Molecular , Reprodutibilidade dos Testes , Medição de Risco , Pele/imunologia , Pele/metabolismo , Pele/patologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/patologia , Técnicas de Cultura de Tecidos
13.
J Biochem Mol Toxicol ; 33(7): e22321, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30925002

RESUMO

miR-122 and miR-192 were investigated as indicators of toxic liver injury caused by acetaminophen, but their role in idiosyncratic toxic liver injury remains controversial. So, this work aimed to assess and compare the expressions of miR-122 and miR-192 in two different types of toxic liver injury (intrinsic [acetaminophen] and idiosyncratic [diclofenac]). Forty male adult Wistar albino rats were divided into equal five groups, in which serum liver enzymes; microRNAs (miRNAs) expressions (miR-122 and miR-192) and histopathological findings were studied. The present study showed that (1) miR-122 and miR-192 are good serum biomarkers of toxic liver injury whatever its etiology, as their serum levels exhibited a significantly earlier increase and earlier return to normal baseline levels as compared to serum aminotransferase levels; (2) miR-122 is more specific than miR-192; and (3) both serum levels of miR-122 and miR-192 showed non-significant differences in relation to the type of toxic liver injury.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/sangue , MicroRNAs/sangue , Acetaminofen/efeitos adversos , Acetaminofen/farmacologia , Animais , Biomarcadores/sangue , Masculino , Ratos , Ratos Wistar
14.
Cryo Letters ; 40(2): 129-138, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31017613

RESUMO

BACKGROUND: Cryopreservation of Arabian stallion semen is important in order to improve the function and fertility of frozen/thawed semen in this breed. OBJECTIVE: To investigate the effects of centrifugation, type of semen extenders, and type of cryoprotectants on the quality of frozen/thawed Arabian stallion spermatozoa. MATERIALS AND METHODS: Semen samples collected from four adult Arabian stallions (one ejaculate per week for 10 consecutive weeks) were either processed directly without centrifugation (no centrifugation; NC) or subjected to centrifugation on the gel-free fraction. Centrifugation protocols were divided into six categories; 600 x g for 10 min (C1), 600 x g for 15 min (C2), 900 x g for 10 min (C3), 900 x g for 15 min (C4), 1200 x g for 10 min (C5), or 1200 x g for 15 min (C6) (Experiment 1). Two semen extenders, INRA-82 and modified Kenney's were compared (Experiment 2). Three different cryoprotectants, [namely 5% glycerol, 5% dimethylformamide (DMF) and 2.5% glycerol] plus 2.5% DMF were used (Experiment 3). Following freezing and thawing, motility, viability, plasma membrane integrity, acrosome status and viability index were evaluated. RESULTS: Centrifugation at 600 x g for 15 min before cryopreservation increased (P< 0.05) sperm motility, viability, membrane integrity and percentage of spermatozoa with intact acrosome compared to other centrifugation protocols. Dilution of Arabian stallion semen with INRA-82 before cryopreservation improved (P< 0.05) sperm quality after freezing and thawing compared to modified Kenney's extender. Supplementation of semen diluent INRA-82 with 5% DMF improved (P< 0.05) the quality of frozen/thawed Arabian stallion spermatozoa compared to 5% glycerol. CONCLUSION: These findings suggest that optimized conditions such as centrifugation, types of semen extenders and cryoprotectants play an important role in processing Arabian stallion spermatozoa for cryopreservation.


Assuntos
Criopreservação/veterinária , Crioprotetores/química , Cavalos , Preservação do Sêmen/veterinária , Sêmen , Animais , Centrifugação , Criopreservação/métodos , Masculino , Preservação do Sêmen/métodos , Motilidade dos Espermatozoides , Espermatozoides
15.
Physiol Mol Biol Plants ; 25(3): 787-797, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31168240

RESUMO

Transformed hairy root culture in common buckwheat (Fagopyrum esculentum Moench Rubra cultivar) was investigated for accumulation of amino acids and specific flavonoids. Leaves and stems of F. esculentum were used a starting material for induction of hairy roots via the Agrobacterium rhizogenes A4 strain. The transformed lines were confirmed by PCR detection of rol B gene, and their capability to continuously form hairy roots. Three lines from each explant types depending upon growth kinetics were observed. The hairy root lines were used to measure the contents of 17 amino acids and 3 flavonoids. Overall, the hairy root lines exhibited elevated accumulation of semi-essential amino acids such as lysine, isoleucine, valine, histidine and phenylalanine. Content of proline was increased 3-5 times, likely due to the biotic stress reaction induced with A. rhizogenes. Determination of flavonoids by high-performance liquid chromatography, hesperidine and kaempferol-3-rutinoside, were accumulated in hairy root cultures and didn't detected in non-transformed root. The increase in flavonoids positively correlated with the antioxidant capacity of the hairy root cultures.

16.
Nanotechnology ; 29(23): 235605, 2018 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-29557785

RESUMO

Carbon nanoscrolls (CNS) with their open ended morphology have recently attracted interest due to the potential application in gas capture, biosensors and interconnects. However, CNS currently suffer from the same issue that have hindered widespread integration of CNTs in sensors and devices: formation is done ex situ, and the tubes have to be placed with precision and reliability-a difficult task with low yield. Here, we demonstrate controlled in situ formation of electrically contacted CNS from suspended graphene nanoribbons with slight tensile stress. Formation probability depends on the length to width aspect ratio. Van der Waals interaction between the overlapping layers fixes the nanoscroll once formed. The stability of these CNSs is investigated by helium nano ion beam assisted in situ cutting. The loose stubs remain rolled and mostly suspended unless subject to a moderate helium dose corresponding to a damage rate of 4%-20%. One CNS stub remaining perfectly straight even after touching the SiO2 substrate allows estimation of the bending moment due to van der Waals force between the CNS and the substrate. The bending moment of 5400 eV is comparable to previous theoretical studies. The cut CNSs show long-term stability when not touching the substrate.

17.
Sensors (Basel) ; 18(8)2018 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-30081581

RESUMO

This paper presents a novel approach to predicting self-calibration in a pressure sensor using a proposed Levenberg Marquardt Back Propagation Artificial Neural Network (LMBP-ANN) model. The self-calibration algorithm should be able to fix major problems in the pressure sensor such as hysteresis, variation in gain and lack of linearity with high accuracy. The traditional calibration process for this kind of sensor is a time-consuming task because it is usually done through manual and repetitive identification. Furthermore, a traditional computational method is inadequate for solving the problem since it is extremely difficult to resolve the mathematical formula among multiple confounding pressure variables. Accordingly, this paper describes a new self-calibration methodology for nonlinear pressure sensors based on an LMBP-ANN model. The proposed method was achieved using a collected dataset from pressure sensors in real time. The load cell will be used as a reference for measuring the applied force. The proposed method was validated by comparing the output pressure of the trained network with the experimental target pressure (reference). This paper also shows that the proposed model exhibited a remarkable performance than traditional methods with a max mean square error of 0.17325 and an R-value over 0.99 for the total response of training, testing and validation. To verify the proposed model's capability to build a self-calibration algorithm, the model was tested using an untrained input data set. As a result, the proposed LMBP-ANN model for self-calibration purposes is able to successfully predict the desired pressure over time, even the uncertain behaviour of the pressure sensors due to its material creep. This means that the proposed model overcomes the problems of hysteresis, variation in gain and lack of linearity over time. In return, this can be used to enhance the durability of the grasping mechanism, leading to a more robust and secure grasp for paralyzed hands. Furthermore, the exposed analysis approach in this paper can be a useful methodology for the user to evaluate the performance of any measurement system in a real-time environment.

18.
Andrologia ; 49(8)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27785836

RESUMO

The present study aimed to investigate effects of rutin on diabetic-induced impairments of sexual behaviour, spermatogenesis and oxidative testicular damage. Diabetes was induced by a single injection of STZ (65 mg/kg) in male adult Wistar rats. Two weeks later, rutin (50 and 100 mg kg-1  day-1 ) was treated to normal and diabetic rats for 5 weeks. Sexual behaviour of the animals was observed by taking stimulus females. At the end of the study, sperm count, motility and viability were recorded. Serum levels of glucose, inflammatory markers and testosterone were also estimated. In penile tissue, cGMP levels were measured, while lipid peroxidation and antioxidant molecules and enzyme activities were determined. Finally, histopathological changes were evaluated in a cross-section of testis. Diabetic-induced alterations in male sexual behaviour and sperm count, motility and viability were markedly corrected following 5 weeks of rutin treatment to the diabetic animals. Rutin also attenuated the inhibited serum testosterone and penile cGMP content, while improved diabetic-associated inflammation and testicular lipid peroxidation and oxidative stress. Histopathological evaluation revealed damaged testicular tissues in diabetic rats, which was protected following rutin treatment. In conclusion, treatment with rutin improved sexual functionality and also protects against diabetic-induced testicular damage.


Assuntos
Antioxidantes/uso terapêutico , Diabetes Mellitus Experimental/complicações , Disfunção Erétil/tratamento farmacológico , Rutina/uso terapêutico , Comportamento Sexual Animal/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Sobrevivência Celular/efeitos dos fármacos , GMP Cíclico/metabolismo , Diabetes Mellitus Experimental/metabolismo , Modelos Animais de Doenças , Disfunção Erétil/etiologia , Disfunção Erétil/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Pênis/efeitos dos fármacos , Pênis/metabolismo , Ratos , Ratos Wistar , Rutina/farmacologia , Contagem de Espermatozoides , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Testículo/metabolismo , Testosterona/sangue
20.
Environ Monit Assess ; 187(8): 517, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26202815

RESUMO

Seasonal variations in species composition, abundance and biomass of tintinnids (Protozoa: Ciliata) were investigated in the Western Harbour, seasonally during 2012. There were remarkable seasonal variations in environmental parameters, phytoplankton concentrations and abundance and biomass of tintinnids: highest in spring and lowest in autumn. Annual average abundance and biomass of tintinnids were 8.435 ind. l(-1) and 3.725 µg C l(-1), respectively. A total of 29 species of tintinnids belonging to 11 genera was identified. Of which, Tintinnopsis was the most abundant genus in terms of number of species (9), but Favella was the best quantitatively (89% of the total tintinnids). The overall mean abundance and biomass were highest (mean 24.415 ind. l(-1) and 10.355 µg C l(-1), respectively) during spring than the remaining seasons. Due to significant positive relationship between the total biomass of tintinnids and phytoplankton concentrations, food supply is not a problem for tintinnids harbouring in the Western Harbour. Hence, predation loss by meso- and macrozooplankton might be the possible reasons for the estimated low biomass of tintinnids in the present study. Some of the seasonal environmental factors as water salinity, nitrite, dissolved oxygen and pH values exert an influence on the species composition, abundance and biomass of tintinnids.


Assuntos
Biodiversidade , Cilióforos , Biomassa , Cilióforos/classificação , Egito , Mar Mediterrâneo , Fitoplâncton , Estações do Ano
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