306 research outputs found
Copper adsorption from aqueous solution by activated carbon of wax beans waste activated by magnetite nanoparticles
Copper, a heavy metal, causes environmental pollution through a variety of industrial processes in many countries. Adsorption is known as an effective and efficient way of removing heavy metals. The present study was conducted mainly to magnetize the carbon in wax bean waste with magnetite nanoparticles and use it as adsorbent to remove copper from aqueous solution. Carbon was obtained from wax beans waste and activated with magnetite nanoparticles. The characteristics of obtaining adsorbent were studied and analyzed by FE-SEM, BET, and FT-IR. In this study, the effect of pH, adsorbent dose, contact time and copper concentration on the efficiency of copper removal was investigated per full factorial design by the Design Expert Software. The concentration of copper was measured by atomic absorption spectrophotometer (Varian AA240). For statistical analysis of the experiment’s data, ANOVA and P-value were used. Copper initial concentration 100 mg/L, adsorbent dose 1 g/L, pH 7 and contact time 40 min were obtained as optimal conditions for copper removal. Investigation of the isotherms indicated that the experimental data of the process were correlated with Langmuir Model. The maximum capacity of copper adsorption of Langmuir Model was 49.75 mg/g. Findings indicated that at optimal conditions, the amount of copper adsorbed from synthetic wastewater and real wastewater was 99.73% and 63%, respectively. Therefore, this method is capable of removing copper effectively and could be used to remove this metal from industrial wastewaters. © 2018 Desalination Publications. All rights reserved
Chitosan-titanium dioxide-glucantime nanoassemblies effects on promastigote and amastigote of Leishmania major
The purpose of the present study was to design nanoassemblies of chitosan-titanium dioxide (TiO2) nanoparticles (NPs) loaded with glucantime for using their synergistic effects and enhancing the toxic effects of glucantime on Leishmania parasites. The nanoassemblies were prepared by electrostatic interactions and optimized by a response surface central composite design. The effects of glucantime, chitosan and TiO2 NPs amounts were studied on the particle size, zeta potential, loading efficiency, and release efficiency of drug from nanoassemblies. The conjugation of TiO2/chitosan-glucantime was verified by UV spectroscopy and changes in surface charge of NPs. The anti-promastigots effect of glucantime loaded in TiO2/chitosan nanoassemblies was studied by tripan blue dye test and their anti-amastigotes effect by counting the average number of parasites per infected J774 macrophages in 100 cells. The optimized formulation obtained by using 12.5 mg glucantime, 25 mg chitosan and 6 mg TiO2 NPs. Although TiO2 NPs alone were effective more than negative control in reduction of promastigots and amastigotes but they didn't show significant difference compared with free glucantime (p > 0.05). However, at the concentration of 50 μg/mL and after 72 h exposure nanoassemblies decreased the proliferation of L. major promastigotes and amastigotes 13 and 4-fold, respectively compared with glucantime alone. © 2017 Elsevier B.V
Effect of Estradiol and Soy Extract on the Onset of PTZ-Induced Seizure in Ovariectomized Rats: Implications for Nurses and Midwives
Background: In many epileptic women, the ovarian cycle influences the risk and severity of seizures. Previous studies have reported inconsistent findings regarding the neural excitatory effects of estrogen. Soybean is a rich source of plant estrogens. Therefore, soy intake can affect the risk and severity of seizures in women. Nurses and midwives need to be aware of the effects of diets containing estrogen in pregnant and post-menopausal women, as well as during the sexual cycle periods.
Objectives: Due to the limitations of human studies, this study aimed to investigate the effect of estradiol and soy extract on the onset of pentylenetetrazol (PTZ)-induced seizures in ovariectomized rats.
Materials and Methods: In this experimental study, sixty female Wistar rats were randomly divided into six groups of ten. All of the groups except for the negative control groups were ovariectomized. One group received estradiol (100 µg/kg), one group was treated with alcoholic extract of soy (20 mg/kg), and the other group received vehicle over 28 days. PTZ (90 mg/kg) was used to induce seizure in all groups. Behavioral changes were observed over 30 minutes. All data were analyzed using a two-way analysis of variance with Tukey’s post-hoc test.
Results: The mean ± SD of the clonic seizure threshold was 61.84 ± 8.53 in the group that received estradiol, while it was 71.70 ± 10.85 in the control group, 64.69 ± 3.23 in rats with laparotomy without removing the ovaries, 51.30 ± 6.84 in rats with laparotomy and removing the ovaries, 52.7 ± 7.18 in ovariectomized rats that received sesame oil as vehicle, and 59.2 ± 4.91, in the soy groups. Therefore, estradiol significantly increased the clonic seizure threshold, while the alcoholic extract of soy had no effect.
Conclusions: We concluded that the chronic administration of estradiol has an anticonvulsant effect in the animal model. However, alcoholic extract of soy has no effect on the onset of clonic seizures
Removing orientation-induced localization biases in single-molecule microscopy using a broadband metasurface mask
Nanoscale localization of single molecules is a crucial function in several advanced microscopy techniques, including single-molecule tracking and wide-field super-resolution imaging. Until now, a central consideration of such techniques is how to optimize the precision of molecular localization. However, as these methods continue to push towards the nanometre size scale, an increasingly important concern is the localization accuracy. In particular, single fluorescent molecules emit with an anisotropic radiation pattern of an oscillating electric dipole, which can cause significant localization biases using common estimators. Here we present the theory and experimental demonstration of a solution to this problem based on azimuthal filtering in the Fourier plane of the microscope. We do so using a high-efficiency dielectric metasurface polarization/phase device composed of nanoposts with subwavelength spacing. The method is demonstrated both on fluorophores embedded in a polymer matrix and in dL5 protein complexes that bind malachite green
Spread of efflux pump overexpressing-mediated fluoroquinolone resistance and multidrug resistance in Pseudomonas aeruginosa by using an efflux pump inhibitor
Background: Fluoroquinolone resistance in Pseudomonas aeruginosa may be due to efflux pump overexpression and/or target mutations. We designed this study to investigate the efflux pump mediated fluoroquinolone resistance and check the increasing effectiveness of fluoroquinolones in combination with an efflux pumps inhibitor among P. aeruginosa isolates from burn wounds infections. Materials and Methods: A total of 154 consecutive strains of P. aeruginosa were recovered from separate patients hospitalized in a burn hospital, Tehran, Iran. The isolates first were studied by disk diffusion antibiogram for 11 antibiotics and then minimum inhibitory concentration (MIC) experiments were performed to detect synergy between ciprofloxacin and the efflux pump inhibitor, carbonyl cyanide-m-chlorophenyl hydrazone (CCCP). Then to elucidate the inducing of multi drug resistance due to different efflux pumps activation in Fluoroquinolone resistant isolates, synergy experiments were also performed in random ciprofloxacin resistant isolates which have overexpressed efflux pumps phenotypically, using CCCP and selected antibiotics as markers for Beta-lactams and Aminoglycosides. The isolates were also tested by polymerase chain reaction (PCR) for the presence of the MexA, MexC and MexE, which encode the efflux pumps MexAB-OprM, MexCD-OprJ and MexEF-OprN. Results: Most of the isolates were resistant to 3 or more antibiotics tested. More than half of the ciprofloxacin resistant isolates exhibited synergy between ciprofloxacin and CCCP, indicating the efflux pump activity contributed to the ciprofloxacin resistance. Also increased susceptibility of random ciprofloxacin resistant isolates of P. aeruginosa to other selected antibiotics, in presence of CCCP, implied multidrug extrusion by different active efflux pump in fluoroquinolones resistant strains. All of Ciprofloxacin resistant isolates were positive for MexA, MexC and MexE genes simultaneously. Conclusion: In this burn hospital, where multidrug resistant P. aeruginosa isolates were prevalent, ciprofloxacin resistance and multidrug resistance due to the overexpression of fluoroquinolones mediated efflux pumps has also now emerged. Early recognition of this resistance mechanism should allow the use of alternative antibiotics and use an efflux pumps inhibitor in combination with antibiotic therapy. © 2015 by The Korean Society of Infectious Diseases
Chitosan-titanium dioxide-glucantime nanoassemblies effects on promastigote and amastigote of Leishmania major
The purpose of the present study was to design nanoassemblies of chitosan-titanium dioxide (TiO2) nanoparticles (NPs) loaded with glucantime for using their synergistic effects and enhancing the toxic effects of glucantime on Leishmania parasites. The nanoassemblies were prepared by electrostatic interactions and optimized by a response surface central composite design. The effects of glucantime, chitosan and TiO2 NPs amounts were studied on the particle size, zeta potential, loading efficiency, and release efficiency of drug from nanoassemblies. The conjugation of TiO2/chitosan-glucantime was verified by UV spectroscopy and changes in surface charge of NPs. The anti-promastigots effect of glucantime loaded in TiO2/chitosan nanoassemblies was studied by tripan blue dye test and their anti-amastigotes effect by counting the average number of parasites per infected J774 macrophages in 100 cells. The optimized formulation obtained by using 12.5 mg glucantime, 25 mg chitosan and 6 mg TiO2 NPs. Although TiO2 NPs alone were effective more than negative control in reduction of promastigots and amastigotes but they didn't show significant difference compared with free glucantime (p > 0.05). However, at the concentration of 50 μg/mL and after 72 h exposure nanoassemblies decreased the proliferation of L. major promastigotes and amastigotes 13 and 4-fold, respectively compared with glucantime alone. © 2017 Elsevier B.V
Removing orientation-induced localization biases in single-molecule microscopy using a broadband metasurface mask
Nanoscale localization of single molecules is a crucial function in several advanced microscopy techniques, including single-molecule tracking and wide-field super-resolution imaging. Until now, a central consideration of such techniques is how to optimize the precision of molecular localization. However, as these methods continue to push towards the nanometre size scale, an increasingly important concern is the localization accuracy. In particular, single fluorescent molecules emit with an anisotropic radiation pattern of an oscillating electric dipole, which can cause significant localization biases using common estimators. Here we present the theory and experimental demonstration of a solution to this problem based on azimuthal filtering in the Fourier plane of the microscope. We do so using a high-efficiency dielectric metasurface polarization/phase device composed of nanoposts with subwavelength spacing. The method is demonstrated both on fluorophores embedded in a polymer matrix and in dL5 protein complexes that bind malachite green
Effect of estradiol and soy extract administration on pentylenetetrazole induced clonic seizures and serum levels of nitric oxide metabolites in ovariectomized rats
Introduction: Estrogen influences neuronal activity and there are controversial reports regarding its role on seizure. Also, previous studies have shown that estrogen influences the nitric oxide pathway in the nervous system. In this way, the aim of the present study was to investigate the effect of estradiol and soy extract as a phytoestrogen on pentylenetetrazole-induced clonic seizures and serum levels of nitric oxide metabolites (NOx) in ovariectomized rats. Materials and Methods: Sixty female Wistar rats were randomly divided into six groups (n =10 in each group) including intact control, sham-control, ovariectomy, vehicle, estradiol (100 μg/kg, subcutaneously), and soy extract (20 mg/kg, gavage). After 28 days of estradiol or soy extract adminstration, single dose of pentylenetetrazole was injected (90 mg/kg, intraperitoneally) for seizure induction and latency to the clonic seizures was recorded. Serum levels of NOx were measured by Griess method. Results: Ovariectomy significantly reduced the latency of clonic seizures and serum levels of NOx. Estradiol significantly increased the latency of clonic seizures and serum levels of NOx (P < 0.05). Soy administration had not significant effect on these parameters. Conclusion: Ovarian hormones have influence on seizure and nitric oxide pathway anticonvulsant effect of estradiol is related due to modulation of nitric oxide pathway slightly. © 2018, Semnan University of Medical Sciences. All rights reserved
Wavefront shaping with disorder-engineered metasurfaces
Recently, wavefront shaping with disordered media has demonstrated optical manipulation capabilities beyond those of conventional optics, including extended volume, aberration-free focusing and subwavelength focusing. However, translating these capabilities to useful applications has remained challenging as the input–output characteristics of the disordered media (P variables) need to be exhaustively determined via O(P) measurements. Here, we propose a paradigm shift where the disorder is specifically designed so its exact input–output characteristics are known a priori and can be used with only a few alignment steps. We implement this concept with a disorder-engineered metasurface, which exhibits additional unique features for wavefront shaping such as a large optical memory effect range in combination with a wide angular scattering range, excellent stability, and a tailorable angular scattering profile. Using this designed metasurface with wavefront shaping, we demonstrate high numerical aperture (NA > 0.5) focusing and fluorescence imaging with an estimated ~2.2 × 10^8 addressable points in an ~8 mm field of view
Molecular imaging of glioblastoma multiforme using anti-insulin-like growth factor-binding protein-7 single-domain antibodies
BACKGROUND: Insulin-like growth factor-binding protein 7 (IGFBP7) is an abundant, selective and accessible biomarker of glioblastoma multiforme (GBM) tumour vessels. In this study, an anti-IGFBP7 single-domain antibody (sdAb) was developed to target GBM vessels for molecular imaging applications. METHODS: Human GBM was modelled in mice by intracranial implantation of U87MG.EGFRvIII cells. An anti-IGFBP7 sdAb, isolated from an immune llama library by panning, was assessed in vitro for its binding affinity using surface plasmon resonance and by ex vivo immunobinding on mouse and human GBM tissue. Tumour targeting by Cy5.5-labelled anti-IGFBP7 sdAb as well as by anti-IGFBP7 sdAb conjugated to PEGylated Fe3O4 nanoparticles (NPs)-Cy5.5 were assessed in U87MG.EGFRvIII tumour-bearing mice in vivo using optical imaging and in brain sections using fluorescent microscopy. RESULTS: Surface plasmon resonance analyses revealed a medium affinity (KD\ufffd40\ufffd50 nM) binding of the anti-IGFBP7 sdAb to the purified antigen. The anti-IGFBP7 sdAb also selectively bound to both mouse and human GBM vessels, but not normal brain vessels in tissue sections. In vivo, intravenously injected anti-IGFBP7 sdAb-Cy5.5 bound to GBM vessels creating high imaging signal in the intracranial tumour. Similarly, the anti-IGFBP7 sdAb-functionalised PEGylated Fe3O4 NP-Cy5.5 demonstrated enhanced tumour signal compared with non-targeted NPs. Fluorescent microscopy confirmed the presence of anti-IGFBP7 sdAb and anti-IGFBP7 sdAb- PEGylated Fe3O4 NPs selectively in GBM vessels. CONCLUSIONS: Anti-IGFBP7 sdAbs are novel GBM vessel-targeting moieties suitable for molecular imaging.Peer reviewed: YesNRC publication: Ye
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