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1.
J Endocrinol Invest ; 47(11): 2731-2743, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38647948

RESUMO

PURPOSE: There is limited research on the effects of maternal hyperandrogenism (MHA) on cardiometabolic risk factors in male offspring. We aimed to compare the risk of metabolic syndrome (MetS) in sons of women with preconceptional hyperandrogenism (HA) to those of non-HA women in later life. METHODS: Using data obtained from the Tehran Lipid and Glucose Cohort Study, with an average of 20 years follow-up, 1913 sons were divided into two groups based on their MHA status, sons with MHA (n = 523) and sons without MHA (controls n = 1390). The study groups were monitored from the baseline until either the incidence of events, censoring, or the end of the study period, depending on which occurred first. Age-scaled unadjusted and adjusted Cox regression models were utilized to evaluate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between MHA and MetS in their sons. RESULTS: There was no significant association between MHA and HR of MetS in sons with MHA compared to controls, even after adjustment (unadjusted HR (95% CI) 0.94 (0.80-1.11), P = 0.5) and (adjusted HR (95% CI) 0.98 (0.81-1.18), P = 0.8). Sons with MHA showed a HR of 1.35 for developing high fasting blood sugar compared to controls (unadjusted HR (95% CI) 1.35 (1.01-1.81), P = 0.04), however, after adjustment this association did not remain significant (adjusted HR (95% CI) 1.25 (0.90-1.74), P = 0.1). CONCLUSION: The results suggest that preconceptional MHA doesn't increase the risk of developing MetS in sons in later life. According to this suggestion, preconceptional MHA may not have long-term metabolic consequences in male offspring.


Assuntos
Hiperandrogenismo , Síndrome Metabólica , Efeitos Tardios da Exposição Pré-Natal , Humanos , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/etiologia , Hiperandrogenismo/epidemiologia , Hiperandrogenismo/complicações , Feminino , Masculino , Adulto , Gravidez , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/etiologia , Seguimentos , Fatores de Risco , Irã (Geográfico)/epidemiologia , Incidência , Estudos de Coortes
2.
J Endocrinol Invest ; 46(9): 1775-1785, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37081228

RESUMO

PURPOSE: Prenatal androgen exposure could be a source of early programming, leading to the development of cardiometabolic diseases in later life. In this study, we aimed to examine cardiometabolic disturbances in males exposed to maternal androgen excess during their prenatal life. METHODS: In this prospective population-based study, 409 male offspring with maternal hyperandrogenism (MHA), and 954 male offspring without MHA, as controls, were included. Both groups of male offspring were followed from the baseline to the date of the incidence of events, censoring, or end of the study period, whichever came first. Age-scaled unadjusted and adjusted Cox regression models were applied to assess the hazard ratios (HR) and 95% confidence intervals (CIs) for the association between MHA with pre-diabetes mellitus (Pre-DM), type 2 diabetes mellitus (T2DM), pre-hypertension (Pre-HTN), hypertension (HTN), dyslipidemia, overweight, and obesity in the offspring of both groups. Statistical analysis was performed using the STATA software package; the significance level was set at P < 0.05. RESULTS: A higher risk of Pre-DM (adjusted HR: 1.46 (1.20, 1.78)) was observed in male offspring with MHA after adjustment for potential confounders, including body mass index, education, and physical activity. However, no significant differences were observed in the risk of T2DM, Pre-HTN, HTN, dyslipidemia, overweight, and obesity in males with MHA compared to controls in both the unadjusted and adjusted models. CONCLUSION: Maternal androgen excess increases the risk of Pre-DM in male offspring in later life. More longitudinal studies with long enough follow-up are needed to clarify the effects of MHA on the cardiometabolic risk factors of male offspring in later life.


Assuntos
Diabetes Mellitus Tipo 2 , Diabetes Gestacional , Hipertensão , Gravidez , Feminino , Humanos , Masculino , Seguimentos , Diabetes Gestacional/epidemiologia , Androgênios , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/etiologia , Sobrepeso/epidemiologia , Estudos Prospectivos , Obesidade/epidemiologia , Hipertensão/epidemiologia , Hipertensão/etiologia , Índice de Massa Corporal , Fatores de Risco
3.
ScientificWorldJournal ; 2014: 375206, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24592165

RESUMO

The objective of the research was to understand and improve the unusual physical and atomization properties of the complexes/adhesives derived from the tapioca starch by addition of borate and urea. The characterization of physical properties of the synthesized adhesives was carried out by determining the effect of temperature, shear rate, and mass concentration of thickener/stabilizer on the complex viscosity, density, and surface tension. In later stage, phenomenological analyses of spray jet breakup of heated complexes were performed in still air. Using a high speed digital camera, the jet breakup dynamics were visualized as a function of the system input parameters. The further analysis of the grabbed images confirmed the strong influence of the input processing parameters on full cone spray patternation. It was also predicted that the heated starch adhesive solutions generate a dispersed spray pattern by utilizing the partial evaporation of the spraying medium. Below 40°C of heating temperature, the radial spray cone width and angle did not vary significantly with increasing Reynolds and Weber numbers at early injection phases leading to increased macroscopic spray propagation. The discharge coefficient, mean flow rate, and mean flow velocity were significantly influenced by the load pressure but less affected by the temperature.


Assuntos
Aerossóis/química , Manihot/química , Amido/química , Adesivos/química , Boratos/química , Técnicas de Química Sintética/instrumentação , Temperatura Alta , Ureia/química
4.
ScientificWorldJournal ; 2014: 279868, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24683326

RESUMO

Multitip probes are very useful diagnostics for analyzing and controlling the physical phenomena occurring in low temperature discharge plasmas. However, DC biased probes often fail to perform well in processing plasmas. The objective of the work was to deduce simple designs of DC biased multitip probes for parametric study of radio frequency plasmas. For this purpose, symmetric double probe, asymmetric double probe, and symmetric triple probe diagnostic systems and their driving circuits were designed and tested in an inductively coupled plasma (ICP) generated by a 13.56 MHz radio frequency (RF) source. Using I-V characteristics of these probes, electron temperature, electron number density, and ion saturation current was measured as a function of input power and filling gas pressure. An increasing trend was noticed in electron temperature and electron number density for increasing input RF power whilst a decreasing trend was evident in these parameters when measured against filling gas pressure. In addition, the electron energy probability function (EEPF) was also studied by using an asymmetric double probe. These studies confirmed the non-Maxwellian nature of the EEPF and the presence of two groups of the energetic electrons at low filling gas pressures.


Assuntos
Desenho Assistido por Computador , Condutometria/instrumentação , Eletrodos , Gases em Plasma/análise , Gases em Plasma/química , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento , Ondas de Rádio
5.
ScientificWorldJournal ; 2014: 940502, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25436237

RESUMO

Melamine formaldehyde (MF) resins have been synthesized at different reaction temperature and pH values. Different molar ratios of melamine and formaldehyde were used to synthesize the corresponding resins. The prepared resin samples were characterized by using molecular weight determination viscometry and thermogravimetric analysis (TGA). The maximum percentage of solid content (69.7%) was obtained at pH 8.5 and 75°C temperature. The molecular weight of MF resin was increased with an increase of melamine monomer concentration. The highest residual weight 14.125 wt.% was obtained with sample 10.


Assuntos
Resinas Sintéticas/síntese química , Temperatura , Triazinas/síntese química , Triazinas/metabolismo , Resinas Sintéticas/metabolismo
6.
ScientificWorldJournal ; 2013: 796081, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24307881

RESUMO

The hot water sprays are an important part of many industrial processes, where the detailed knowledge of physical phenomena involved in jet transportation, interaction, secondary breakup, evaporation, and coalescence of droplets is important to reach more efficient processes. The objective of the work was to study the water spray jet breakup dynamics, vortex cloud formation, and droplet size distribution under varying temperature and load pressure. Using a high speed camera, the spray patterns generated by axisymmetric full cone nozzles were visualized as a function water temperature and load pressure. The image analysis confirmed that the spray cone angle and width do not vary significantly with increasing Reynolds and Weber numbers at early injection phases leading to increased macroscopic spray propagation. The formation and decay of semitorus like vortex clouds were also noticed in spray structures generated at near water boiling point temperature. For the nozzle with smallest orifice diameter (1.19 mm), these vortex clouds were very clear at 90°C heating temperature and 1 bar water load pressure. In addition, the sauter mean diameter (SMD) of the spray droplets was also measured by using Phase Doppler Anemometry (PDA) at different locations downstream of the nozzle exit. It was noticed that SMD varies slightly w.r.t. position when measured at room temperature whereas at higher temperature values, it became almost constant at distance of 55 mm downstream of the nozzle exit.


Assuntos
Hidrodinâmica , Tecnologia/instrumentação , Desenho de Equipamento , Temperatura Alta , Tamanho da Partícula , Pressão , Água
7.
Adv Colloid Interface Sci ; 304: 102661, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35462267

RESUMO

Although photocatalytic technology has emerged as an effective means of alleviating the projected future fuel crisis by converting sunlight directly into chemical energy, no visible-light-driven, low-cost, and highly stable photocatalyst has been developed to date. Due to considerably higher interfacial contact with numerous reactive sites, effective charge transmission and separation ability, and strong redox potentials, the focus has now shifted to 2D/2D heterojunction systems, which have exhibited effective photocatalytic performance. The fundamentals of 2D/2D photocatalysis for different applications and the classification of 2D/2D materials are first explained in this paper, followed by strategies to improve the photocatalytic performance of various 2D/2D heterojunction systems. Following that, current breakthroughs in 2D/2D metal-based and metal-free heterojunction photocatalysts, as well as their applications for H2 evolution via water splitting, CO2 reduction, and N2 fixation, are discussed. Finally, a brief overview of current constraints and predicted results for 2D/2D heterojunction systems is also presented. This paper lays out a strategy for developing efficient 2D/2D heterojunction photocatalysts and sophisticated technology for solar fuel applications in order to address the energy issue.

8.
Sci Rep ; 11(1): 2896, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33536469

RESUMO

An argon plasma jet was sustained in open air and characterized for its chemical composition. The optically characterized plasma jet was used to treat industrial wastewater containing mixed textile dyes and heavy metals. Since plasma jet produces UV-radiations, the photocatalytic TiO2 was used to enhance plasma treatment efficiency especially for degradation of dyes. Mixed anatase and rutile phases of TiO2 (5.2-8.5 nm) were produced through surfactant assisted sol-gel approach. The emission spectrum confirmed the presence of excited argon, OH, excited nitrogen, excited oxygen, ozone and nitric oxide in the plasma jet. The spectral lines of excited Ar, NO, O3, OH-, N2, [Formula: see text], O, [Formula: see text] and O+ species were observed at wavelength of 695-740 nm, 254.3 nm, 307.9 nm, 302-310 nm, 330-380 nm, 390-415 nm, 715.6 nm, 500-600 nm and 400-500 nm. These reactive species decompose the organic pollutants and separate the heavy metals from the water samples. The conductivity of plasma exposed water samples increased while pH and hardness decreased. The atomic absorption spectrophotometry analysis confirmed the presence of heavy metals in the samples, which were effectively removed through plasma treatment. Finally, the effect of plasma treatment on Staphylococcus aureus strains was more pronounced than Escherichia coli strains.

9.
Nanoscale Res Lett ; 15(1): 144, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32643064

RESUMO

The present research is a comparative study that reports an economical and accessible method to synthesize niobium (Nb) and Tantalum (Ta) selenides and tellurides with useful application in the removal of pollutants in textile, paper, and dyeing industries as well as in medical field. In this study, solid-state process was used to generate nanocomposites and various characterization techniques were employed to compare two groups of materials under investigation. Structure, morphology, elemental constitution, and functional groups of synthesized materials were analyzed with XRD, FESEM coupled with EDS, FTIR, and Raman spectroscopy, respectively. HR-TEM images displayed nanoscale particles with tetragonal and monoclinic crystal structures. The optical properties were evaluated in terms of cut-off wavelength and optical band gap using UV-visible spectroscopy. A comparative behavior of both groups of compounds was assessed with regards to their catalytic and microcidal properties. Extracted nanocomposites when used as catalysts, though isomorphs of each other, showed markedly different behavior in catalytic degradation of MB dye in the presence of NaBH4 that was employed as a reducing agent. This peculiar deviation might be attributed to slight structural differences between them. Escherichia coli and Staphylococcus aureus (G -ve and + ve bacteria, respectively) were designated as model strains for in vitro antibacterial tests of both clusters by employing disk diffusion method. Superior antibacterial efficacy was observed for telluride system (significant inhibition zones of 26-35 mm) compared with selenide system (diameter of inhibition zone ranged from 0.8 mm to 1.9 mm). In addition, molecular docking study was undertaken to ascertain the binding interaction pattern between NPs and active sites in targeted cell protein. The findings were in agreement with antimicrobial test results suggesting NbTe4 to be the best inhibitor against FabH and FabI enzymes.

10.
Sci Rep ; 10(1): 15548, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32968140

RESUMO

This study examines the analytical and numerical solution of electromagnetic surface waves supported by a resistive metasurface-covered grounded metamaterial structure. To simulate the metamaterial, the Kramers-Kronig relation based on the causality principle is used, while the modeling of the resistive metasurface has been done by implementing the impedance boundary conditions. The analytical expressions for the field phasors of surface waves are developed for the transverse magnetic (TM) polarized mode and transverse electric (TE) polarized mode. The characteristic equations are computed for both modes, and the unknown propagation constant is evaluated numerically in the kernel. After computation, the dispersion curves, electric field profiles, effective mode index ([Formula: see text]), and phase speeds ([Formula: see text]) are presented for both the TM and TE polarized modes. To study the tunability of surface waves, the influence of the thickness of the metamaterial slab ([Formula: see text]), effective permittivity of the metamaterial ([Formula: see text]), thickness of the resistive metasurface ([Formula: see text]), and effective permittivity of the metasurface ([Formula: see text]) on all the numerical results has been studied. However, the geometrical parameters are found to be more sensitive to the effective mode index ([Formula: see text]) and phase speed ([Formula: see text]) of the surface waves. The results are consistent with the published results, which reflects the accuracy of the work. It is concluded that the appropriate choice of parameters can be used to achieve surface waves with the desired characteristics in the GHz range. The present work may have potential applications in surface waveguide design, surface wave speed controllers, surface communication devices, and light trapping configurations.

11.
Sci Rep ; 10(1): 5927, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32246028

RESUMO

The world does not have too much time to ensure that the fast-growing population has enough land, food, water and energy. The rising food demand has brought a positive surge in fertilizers' demand and agriculture-based economy. The world is using 170 million tons of fertilizer every year for food, fuel, fiber, and feed. The nitrogenous fertilizers are being used to meet 48% of the total food demand of the world. High fertilizer inputs augment the reactive nitrogen levels in soil, air, and water. The unassimilated reactive nitrogen changes into a pollutant and harms the natural resources. The use of controlled-release fertilizers for slowing down the nutrients' leaching has recently been practiced by farmers. However, to date, monitoring of the complete discharge time and discharge rate of controlled released fertilizers is not completely understood by the researchers. In this work, corn starch was thermally processed into a week gel-like coating material by reacting with urea and borate. The granular urea was coated with native and processed starch in a fluidized bed reactor having bottom-up fluid delivery system. The processed starch exhibited better thermal and mechanical stability as compared to the native starch. Unlike the pure starch, the storage modulus of the processed starch dominated the loss modulus. The release time of urea, coated with processed starch, remained remarkably larger than the uncoated urea.

12.
Rev Sci Instrum ; 91(4): 045106, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32357722

RESUMO

Fluidized bed technology is being used in several industrial processes. The well-controlled fluidization of a bed material is a prerequisite for successful implementation of this technology. Several variants of distributors are being tested for fluidized beds; however, scant information is available on their working regimes. In this study, an annular distributor was constructed by fixing blades between two concentric rings and covering the assembly with a wire mesh. This new distributor design was tested for fluidization of batches of a spherical bed material at different blade angles and superficial air velocities (SAVs). High-speed imaging and MATLAB supported velocimetry techniques were used to generate velocity vector fields of fluidized beds. These fields were analyzed further for bed velocity measurements at different bed zones. A response surface regression model was applied on the data to predict the response of the bed parameters. Statistically, the bed velocity was predicted to be about 0.497 m/s with the confidence interval in the range of 0.4948-0.4999. The experimental bed velocity remained between 0.531 m/s and 0.538 m/s under an optimized blade angle of 60°, SAV of 2.3 m/s, and bed weight of 500 g.

13.
Eur J Med Chem ; 42(8): 1069-75, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17350734

RESUMO

The 1,6-bis(benzimidazol-2-yl)-3,4-dithiahexane (1) ligand and its palladium(II) chloride complex [(micro(2)-SCH(2)CH(2)NHNCC(6)H(4))PdCl](2)xC(2)H(5)OH (2) have been synthesised and characterised by spectroscopical methods. The crystal structure of the triclinic title compound (P-1 (no. 2), a=879.6(1) pm, b=984.4(1) pm, c=1471.8(2) pm; alpha=94.330(6) degrees , beta=98.546(6) degrees , gamma=99.258(7) degrees , Z=2) was solved from X-ray single crystal diffraction data. In the binuclear complex, each palladium atom is coordinated in a slightly distorted square-planar arrangement by one nitrogen, two bridging sulphurs and one terminal chlorine atom. Molar conductivity, FT-Raman, FT-IR (mid-i.r., far-i.r.), (1)H and (13)C NMR spectra of the complex (2) have been recorded and show a good accordance with the square-planar geometry. The antimicrobial and antifungal activities of palladium(II) chloride, free ligand, its hydrochloride salt and the complex were evaluated using the disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) the dilution method, against 10 bacteria and five yeast cultures. The results for the antibacterial from the disk diffusion method were assessed in side-by-side comparison with those for penicillin-g, ampicillin, cefotaxime, vancomycin, ofloxacin and tetracycline. Antifungal activities were referenced with nystatin, ketaconazole, and clotrimazole, commercial antifungal agents. The data from the dilution procedure were compared with gentamycin as antibacterial and nystatin as antifungal agent, respectively. In most cases, the compounds tested showed broad-spectrum (Gram positive and Gram negative) activities that were comparatively more active, or as potent as referenced pharmaceutical agents. The palladium complex has the potential to generate new kind of metabolites by displaying high affinities for most of the receptors compared with palladium chloride, free ligand and its hydrochloride salt.


Assuntos
Anti-Infecciosos/química , Compostos Organometálicos/farmacologia , Paládio/farmacologia , Análise Espectral , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Compostos Organometálicos/uso terapêutico , Paládio/uso terapêutico , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Leveduras/efeitos dos fármacos
14.
Eur J Med Chem ; 42(2): 205-13, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17189664

RESUMO

2,6-Bis(benzimidazol-2-yl)pyridine (L) ligand and complexes [M(L)Cl(2)] and [Fe(L)(2)](ClO(4))(2) (M=Zn, Cd, Hg) have been synthesized. The geometries of the [M(L)Cl(2)] complexes were derived from theoretical calculation in DGauss/DFT level (DZVP basis set) on CACHE. The central M(II) ion is penta-coordinated and surrounded by N(3)Cl(2) environment, adopting a distorted trigonal bipyramidal geometry. The ligand is tridentate, via three nitrogen atoms to metal centre and two chloride ions lie on each side of the distorted benzimidazole ring. In the [Fe(L)(2)](ClO(4))(2) complex, the central Fe(II) ion is surrounded by two (3N) units, adopting a octahedral geometry. The elemental analysis, molecular conductivity, FT-Raman, FT-IR (mid-, far-IR), (1)H, and (13)C NMR were reported. The antimicrobial activities of the free ligand, its hydrochloride salt, and the complexes were evaluated using the disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) dilution method, against 10 bacteria and the results compared with that for gentamycin. Antifungal activities were reported for Candida albicans, Kluyveromyces fragilis, Rhodotorula rubra, Debaryomyces hansenii, Hanseniaspora guilliermondii, and the results were referenced against nystatin, ketaconazole, and clotrimazole antifungal agents. In most cases, the compounds tested showed broad-spectrum (Gram positive and Gram negative bacteria) activities that were either more effective than or as potent as the references. The binding of two most biologically effective compounds of zinc and mercury to calf thymus DNA has also been investigated by absorption spectra.


Assuntos
Antibacterianos/síntese química , Antifúngicos/síntese química , Quelantes/síntese química , Metais Pesados , Compostos Organometálicos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Cádmio , Quelantes/química , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Compostos Ferrosos/síntese química , Compostos Ferrosos/química , Compostos Ferrosos/farmacologia , Ligantes , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Compostos Organomercúricos/síntese química , Compostos Organomercúricos/química , Compostos Organomercúricos/farmacologia , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Relação Estrutura-Atividade , Zinco
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 152: 181-91, 2016 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-26210013

RESUMO

The room temperature structural (tautomerism, dimerization, conformational preference, geometry parameters) and vibrational spectral (IR and Raman) analyses have been performed on benzothiazoline (benzothiazoline-2-thione, 3-methyl-benzothiazoline-2-thione) and benzothiazole [2-mercaptobenzothiazole, 2-methylthiobenzothiazole, and bis(benzothiazole-2-ylthio)ethane] derivatives at the B3LYP/6-311++G(∗∗) level of theory. Although the keto to enol transition barriers are too high over the most stable benzothiazoline isomers, vibrational spectral analyses reveal some major bands of benzothiazole isomers in the present room temperature experimental FT-IR and FT-Raman specta. Therefore, benzothiazole isomers exist at rare amounts in the powdered samples that are mainly composed of benzothiazoline isomers. The benzothiazole isomers have two stable conformations due to the orientation of their SH and SCH3 moieties. The energetic and vibrational spectral analyses suggest that the benzothiazoline-2-thione molecules can be stabilized further through the NH⋯S intermolecular hydrogen bonds in solid phase. All observed fundamental vibrational bands of the molecules have been assigned based on the calculated mode frequencies and IR/Raman intensities. The mode assignments have been expressed in terms of internal coordinates and their percent potential energy distributions. The effects of substitution at the nitrogen and peripheral sulfur atoms have been analyzed for the geometries and vibrational bands of the molecules.

16.
Eur J Med Chem ; 40(11): 1096-102, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15992966

RESUMO

1,3-Bis(2-benzimidazyl)-2-thiapropane(L) forms 5-coordinate square pyramidal and 4-coordinate tetrahedral, monometallic complexes with PdCl(2) and ZnX(2) (X=Cl, Br, I), respectively. In the palladium complex, the ligand acts as a chelating tridentate, through two of the nitrogen atoms in the imidazole ring and the sulfur atom of the bridging group together with two chloride ions forming a rare five coordinate complex. In the zinc halide complexes, the ligand acts as chelating bidentate, via two of the nitrogen atoms combined with two halide ions giving common tetrahedral complexes. The ligand and its complexes are characterized by analytical data and spectroscopic methods such as FT-Raman, FT-IR (mid-IR, far-IR), (1)H and (13)C NMR. Their antimicrobial activities are evaluated by the minimal inhibitory concentration (MIC) against 10 bacteria, each with multiple, fresh clinical isolates (10-15), and the results are compared with those of ampicillin, ciprofloxacin, cefazolin, ofloxacin, and piperacillin antibacterial agents. The compound's antifungal activities are reported on Candida albicans, Candida utilis, and Cryptococcus neoformans yeasts, each with multiple isolates (10), and the results are referenced with amphotericin-B, fluconazole and flucytosine antifungal agents. In most cases, the compounds show broad-spectrum (Gram(+) and Gram(-)) activities that are either, more active, or equipotent to, the antibiotic and antifungal agents in the comparison tests.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Benzimidazóis/química , Ligantes , Paládio/química , Propano/análogos & derivados , Zinco/química , Antibacterianos/química , Antifúngicos/química , Benzimidazóis/farmacologia , Quelantes/química , Quelantes/farmacologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Paládio/farmacologia , Propano/química , Propano/farmacologia , Relação Estrutura-Atividade
17.
Sci Rep ; 5: 16583, 2015 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-26561231

RESUMO

This study investigated the dry and aqueous erosion of mild steel using electrochemical and dry sand impact techniques. In dry sand impact experiments, mild steel was eroded with 45 µm and 150 µm sand particles. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-hardness techniques were used to elaborate the surface morphology of the eroded samples. The results revealed significant change in morphology of the eroded samples. In-depth analysis showed that although the metal erosion due to larger particles was significantly higher, the fines also notably damaged the metal surface. The surface damages were appreciably reduced with decrease in impact angle of the accelerated particles. The maximum damages were observed at an impact angle of 90°. The hardness of the samples treated with 45 µm and 150 µm sand remained in the range of 88.34 to 102.31 VHN and 87.7 to 97.55 VHN, respectively. In electrochemical experiments, a triple electrode probe was added into the metal treatment process. The linear polarization resistance (LPR) measurements were performed in slurries having 5% (by weight) of sand particles. LPR of the samples treated with 45 µm and 150 µm sand slurries was calculated about 949 Ω.cm(2) and 809 Ω.cm(2), respectively.

18.
Eur J Med Chem ; 38(10): 875-81, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14575934

RESUMO

The 1,2-bis(2-benzimidazyl)-1,2-ethanediol (1), 1,4-bis(2-benzimidazyl)-1,2,3,4-butanetetraol (2), 1,3-bis(2-benzimidazyl)-2-thiapropane (3), 1,3-bis(2-benzimidazyl)-2-thia-propane-dihydrochloride (4), 1,5-bis(2-benzimidazyl)-3-thiapentane (5), and 1,5-bis(2-benzimidazyl)-3-thiapentane dihydrochloride (6) chelating ligands are synthesised and characterised by using analytical data and modem spectroscopic methods such as FT-Raman, FT-IR, 1H- and 13C-NMR spectrometers. Their antimicrobial activities are reported by comparing the in vitro activities, with those of ofloxacin, ciprofloxacin, piperacillin, ampicillin and cefazolin antibacterial agents against fresh clinical isolates. Antifungal activities are reported on Candida albicans, Candida utilis, Cryptococcus neoformans fungi, and the results are referenced with amphotericin-B, fluconazole and flucytosine antifungal agents. It has been found that all the compounds have broad spectra activity and was either more active or equipotent to those compared antibiotic and antifungal agents.


Assuntos
Anti-Infecciosos/síntese química , Benzimidazóis/síntese química , Quelantes/síntese química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Antifúngicos/síntese química , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Benzimidazóis/farmacologia , Quelantes/farmacologia , Testes de Sensibilidade Microbiana , Análise Espectral , Leveduras/efeitos dos fármacos
19.
Eur J Med Chem ; 44(11): 4681-9, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19700225

RESUMO

Series of new mixed aza-oxo-thia macrocyclic ligands 1,9(2,6)-ditriazina-2,8,10,16-tetraaza-3,7,11,15-tetraoxo-5,13-dithia-cyclohexadecaphan-1(4),9(4)-diphenyl (L(1)); 1,10(2,6)-ditri azina-2,9,11,18-tetraaza-3,8,12,17-tetraoxo-5,6,14,15-tetrathia-cyclooctadecaphan-1(4),10(4)-diphenyl (L(2)); 1,11(2,6)-ditriazina-2,10,12,20-tetraaza-3,9,13,19-tetraoxo-6,16-dithia-cyclocosa-phan-1(4),11(4)-diphenyl (L(3)); 1,12(2,6)-ditriazina-2,11,13,22-tetraaza-3,10,14,21-tetraoxo-6,7,17,18-tetrathia-cyclodocosaphan-1(4),12(4)-diphenyl (L(4)) were synthesised. The structural features of the compounds have been studied by elemental analyses, Mass, FT-Raman, FT-IR, (1)H and (13)C NMR spectroscopy. The antimicrobial activities of the ligands were evaluated using disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) dilution method, against several bacteria and yeast cultures. The obtained results from both methods were assessed in side-by-side comparison with commercial antibacterial and antifungal agents. In most cases, the compounds show strong antifungal activity in the comparison tests. Cytotoxic activities of the ligands against two different human cancer cell lines, stomach (23132/87) and lung (A549) were determined by MTT assay. DNA fragmentation assay tested cell lines were used to analyze the DNA ladder formation which is a characteristic of apoptotic cell death. The binding of the ligands with calf thymus DNA (CT-DNA) has also been investigated by absorption spectroscopy.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Apoptose/efeitos dos fármacos , DNA/metabolismo , Compostos Macrocíclicos/química , Compostos Macrocíclicos/farmacologia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Bovinos , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Leveduras/efeitos dos fármacos
20.
Eur J Med Chem ; 44(3): 1093-9, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18657884

RESUMO

Several families of water soluble dendrimers were synthesized based on poly(propyleneoxide) amines (Jeffamines) (P(1)). P(1)-core and branched units were constructed from both methylacrylate and ethylenediamine (P(2)-P(9), and generations 0-3 with -NH(2), -COOH functionalities). They were characterized by elemental analysis (EA), gel permeation chromatography (GPC), FT-IR, (1)H, and (13)C NMR. The antimicrobial activities of only water soluble compounds (P(1), P(3), P(4), P(6), P(7) and P(9)) were evaluated using disk diffusion method in water as well as the minimal inhibitory concentration (MIC) dilution method against 9 bacteria. The obtained results from disk diffusion method are assessed in side-by-side comparison with those of Penicillin-g, Ampicillin, Cefotaxime, Vancomycin, Oflaxacin, and Tetracycline, well-known antibacterial agents. The results from dilution procedure are compared with Gentamycin as antibacterial and Nystatin as antifungal. The antifungal activities are reported on five yeast cultures namely, Candida albicans, Kluyveromyces fragilis, Rhodotorula rubra, Debaryomyces hansenii, and Hanseniaspora guilliermondii, and the results are referenced with Nystatin, Ketaconazole, and Clotrimazole, commercial antifungal agents. In most cases, the compounds show broad-spectrum (gram-positive and gram-negative bacteria) activities that are comparatively higher or equipotent to the antibiotic and antifungal agents in the comparison tests.


Assuntos
Anti-Infecciosos/síntese química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Cromatografia em Gel , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química
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