•Ecofriendly method for synthesis gold nanoparticles (Au NPs) using Pistacia Atlantica (leave and fruit) extract.•Antibacterial, antioxidant and cytotoxicity properties of Au NPs were studied.•Remove ...toxic conditions.•Green and safe method.
A simple, affordable and ecofriendly method for synthesis gold nanoparticles (Au NPs) using Pistacia Atlantica (leave and fruit) extract at the room temperature, has been carry out in the present study. Higher reaction rate about a minute is so noticeable and Au NPs synthesis with this method provided nontoxic carrier for application. Various analytical technique including UV–vis absorption spectroscopy approved presence of Au NPs in the solution, the functional groups of Pistacia Atlantica extract in the reduction and capping process of Au NPs is determined by FT-IR, crystallinity with the fcc plane approved from the X-ray diffraction (XRD) pattern, energy dispersive spectroscopy (EDS) determined existence of elements in the sample, surface morphology, diverse shapes and size of present Au NPs were showed by using scanning electron microscopy (SEM), atomic force microscopy (AFM) and Transmission electron microscopy (TEM). In addition, antibacterial, antioxidant and cytotoxicity properties of Au NPs were studied. Agar disk and agar well diffusion are the methods to determined antibacterial properties of synthesized Au NPs. Also MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) were recognized by macro broth dilution assay. DPPH free radical scavenging assay was used for antioxidant property and compare to butylated hydroxytoluene (BHT) as standard antioxidant. Synthesized Au NPs have great cell viability in a dose depended manner and demonstrate that this method for synthesis Gold nanoparticles provided nontoxic. The average diameter of synthesized Au NPs was about 50–60 nm.
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Mona Hamelian, Saba Hemmati, Kambiz Varmira,* Hojat Veisi*
One of the most important factors reducing flexible manipulator efficiency is the residual vibration occurrence. In this research, vibration reduction of flexible manipulators is investigated using ...an internal frictional damper. At first, the vibration equation of a manipulator is obtained using the finite element method with the Euler–Bernoulli beam element to study its vibrations in a reciprocal motion. In addition, an analytical model is developed to investigate the effect of the frictional damper on robot link vibrations. Using particle swam optimization, ICA, NSGA-II, and GWO methods, the optimal structure for the damper is obtained to maximize its effect. The optimally damped link is fabricated, and its dynamic characteristics are extracted from a modal test experiment. The modal test results show a considerable improvement in the damping ratio of the damped link in comparison with a simple link. The fabricated link samples are then tested in a realistic situation. The experimental results are in coincidence with the simulation results, certifying the performance of the proposed plan in vibration reduction of a robot link.
Accurate determination of the physicochemical characteristics of ionic liquids (ILs), especially viscosity, at widespread operating conditions is of a vital role for various fields. In this study, ...the viscosity of pure ILs is modeled using three approaches: (I) a simple group contribution method based on temperature, pressure, boiling temperature, acentric factor, molecular weight, critical temperature, critical pressure, and critical volume; (II) a model based on thermodynamic properties, pressure, and temperature; and (III) a model based on chemical structure, pressure, and temperature. Furthermore, Eyring's absolute rate theory is used to predict viscosity based on boiling temperature and temperature. To develop Model (I), a simple correlation was applied, while for Models (II) and (III), smart approaches such as multilayer perceptron networks optimized by a Levenberg-Marquardt algorithm (MLP-LMA) and Bayesian Regularization (MLP-BR), decision tree (DT), and least square support vector machine optimized by bat algorithm (BAT-LSSVM) were utilized to establish robust and accurate predictive paradigms. These approaches were implemented using a large database consisting of 2813 experimental viscosity points from 45 different ILs under an extensive range of pressure and temperature. Afterward, the four most accurate models were selected to construct a committee machine intelligent system (CMIS). Eyring's theory's results to predict the viscosity demonstrated that although the theory is not precise, its simplicity is still beneficial. The proposed CMIS model provides the most precise responses with an absolute average relative deviation (AARD) of less than 4% for predicting the viscosity of ILs based on Model (II) and (III). Lastly, the applicability domain of the CMIS model and the quality of experimental data were assessed through the Leverage statistical method. It is concluded that intelligent-based predictive models are powerful alternatives for time-consuming and expensive experimental processes of the ILs viscosity measurement.
Knowledge of the solubilities of hydrocarbon components of natural gas in pure water and aqueous electrolyte solutions is important in terms of engineering designs and environmental aspects. In the ...current work, six machine-learning algorithms, namely Random Forest, Extra Tree, adaptive boosting support vector regression (AdaBoost-SVR), Decision Tree, group method of data handling (GMDH), and genetic programming (GP) were proposed for estimating the solubility of pure and mixture of methane, ethane, propane, and n-butane gases in pure water and aqueous electrolyte systems. To this end, a huge database of hydrocarbon gases solubility (1836 experimental data points) was prepared over extensive ranges of operating temperature (273-637 K) and pressure (0.051-113.27 MPa). Two different approaches including eight and five inputs were adopted for modeling. Moreover, three famous equations of state (EOSs), namely Peng-Robinson (PR), Valderrama modification of the Patel-Teja (VPT), and Soave-Redlich-Kwong (SRK) were used in comparison with machine-learning models. The AdaBoost-SVR models developed with eight and five inputs outperform the other models proposed in this study, EOSs, and available intelligence models in predicting the solubility of mixtures or/and pure hydrocarbon gases in pure water and aqueous electrolyte systems up to high-pressure and high-temperature conditions having average absolute relative error values of 10.65% and 12.02%, respectively, along with determination coefficient of 0.9999. Among the EOSs, VPT, SRK, and PR were ranked in terms of good predictions, respectively. Also, the two mathematical correlations developed with GP and GMDH had satisfactory results and can provide accurate and quick estimates. According to sensitivity analysis, the temperature and pressure had the greatest effect on hydrocarbon gases' solubility. Additionally, increasing the ionic strength of the solution and the pseudo-critical temperature of the gas mixture decreases the solubilities of hydrocarbon gases in aqueous electrolyte systems. Eventually, the Leverage approach has revealed the validity of the hydrocarbon solubility databank and the high credit of the AdaBoost-SVR models in estimating the solubilities of hydrocarbon gases in aqueous solutions.
To improve the efficiency of electrochemical processes for environmental remediation, we present a new type of hybrid nanomaterials based on leaf-like copper-based quaternary transition metals and ...spongy monolayer graphene. To demonstrate the functionality of the hybrid electrocatalyst, fast and competent electrooxidation of water and glucose is shown. The mechanism of improved catalysis is ascribed to the synergetic catalytic effect of quaternary Cu-Ni-Fe-Co alloy with dendritic morphology along with the highly conductive and spongy structure of the graphene monolayer. It is shown that water oxidation can be performed at a low overpotential of 315 mV to reach a current denisty of 100 mA cm-2 and a low Tafel slope of 63.06 mV dec−1. Fast and sensitive amperometric detection of glucose at low concentrations (≥1.3 μM; 4153 μA mM−1 cm−2) in alkaline solutions is also presented. The compelling performance of the hybrid catalyst as compared with many noble-metal and non-precious metal electrocatalysts for water oxidation and electrochemical sensing is reported.
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One of the primary challenges of landscape knowledge is to develop practical strategies to use the landscape approach on the scale of operational projects. One of the most controversial scales of the ...project is the intermediate scale which is defined as the common border between the architectural project and the landscape, which has not received much attention from experts in either field. In the meantime, “continuous architecture” as an approach based on the “landscape approach” of the project, moves on the border of architecture and landscape. By carefully studying the landscape components of the project, through the two principles of “ time continuity” and “place continuity” of the project platform, the continuous architecture seeks to create a work that, while carrying historical memory, is a harbinger of future prosperity. In addition to these two, it also displays the spirit of his time. Apart from responding to the plan, the work must be formed in interaction with the surrounding natural landscape and express the aesthetics of the geography of its context. This research seeks to analyze the main campus of Koç University, one of the most significant projects formed based on this approach, based on the three-part system of meaning, function or use, and aesthetics. This study also attempts to evaluate its different dimensions and discuss the success of the applied strategies in compliance with the project perspective. On the one hand, considering that the “continuous architecture” approach, despite its relative success in reflecting the landscape approach on the intermediate scale of architecture and landscape, lacks a theoretical background to discover practical strategies to achieve the project’s landscape goals, this research aims to recognize and categorize these approaches through re-reading the project. Finally, the analysis of this work shows its remarkable success in expressing landscape concepts on the intermediate scale of architecture and landscape. The most important strategies in achieving the goal of the project are “Semantic unity”, “Integration of users”, “Flexibility of users”, “Form consistency”, “Form continuity” and “Form reference”.
Pseudomonas aeruginosa is an opportunistic pathogen in the health-care systems and one of the primary causative agents with high mortality in hospitalized patients, particularly immunocompromised. ...The limitation of effective antibiotic administration in multidrug-resistant and extensively drug-resistant P. aeruginosa isolates leads to the development of nosocomial infections and health problems. Quorum sensing system contributes to biofilm formation, expression of bacterial virulence factors, and development of drug resistance, causing prolonged patient infections. Therefore, due to the significance of the quorum sensing system in increasing the pathogenicity of P. aeruginosa, the primary objective of our study was to investigate the frequency of quorum sensing genes, as well as the biofilm formation and antibiotic resistance pattern among P. aeruginosa strains.
A total of 120 P. aeruginosa isolates were collected from different clinical specimens. The disk diffusion method was applied to detect the antibiotic resistance pattern of P. aeruginosa strains. Also, the microtiter plate method was carried out to evaluate the biofilm-forming ability of isolates. Finally, the frequency of rhlI, rhlR, lasI, and lasR genes was examined by the polymerase chain reaction method.
In total, 88.3% P. aeruginosa isolates were found to be multidrug-resistant, of which 30.1% had extensively drug-resistant pattern. The highest and lowest resistance rates were found against ceftazidime (75.0%) and ciprofloxacin (46.6%), respectively. Also, 95.8% of isolates were able to produce biofilm, of which 42.5%, 33.3%, and 20.0% had strong, moderate, and weak biofilm patterns, respectively. The frequency of quorum sensing genes among all examined strains was as follows: rhlI (81.6%), rhlR (90.8%), lasI (89.1%), and lasR (78.3%). The most common type of quorum sensing genes among multidrug-resistant isolates were related to rhlR and lasI genes with 94.3%. Furthermore, rhlI, rhlR, and lasI genes were positive for all extensively drug-resistant isolates. However, the lasR gene had the lowest frequency among both multidrug-resistant (83.0%) and extensively drug-resistant (90.6%) isolates. Moreover, rhlR (94.7%) and lasR (81.7%) genes had the highest and lowest prevalence among biofilm-forming isolates, respectively.
Our findings disclosed the significantly high prevalence of drug resistance among P. aeruginosa isolates. Also, the quorum sensing system had a significant correlation with biofilm formation and drug resistance, indicating the essential role of this system in the emergence of nosocomial infections caused by P. aeruginosa.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Glial cell line‐derived neurotrophic factor (GDNF) has neuroprotective effects and may be a promising candidate for regenerative strategies focusing on neurodegenerative diseases. As GDNF cannot ...cross the blood–brain barrier to potentially regenerate damaged brain areas, continuous in situ delivery with host cells is desired. Here, a non‐viral Sleeping Beauty transposon was used to achieve continuous in vitro overexpression of GDNF in immune‐privileged human adipose tissue‐derived mesenchymal stromal cells (GDNF‐tASCs). In addition, in vivo survival, tolerance, and effectiveness of transfected cells were tested in a very mild 6‐hydroxydopamine (6‐OHDA)‐induced dopamine depletion rat model by means of intrastriatal injection on a sample basis up to 6 months after treatment. GDNF‐tASCs showed vast in vitro gene overexpression up to 13 weeks post‐transfection. In vivo, GDNF was detectable 4 days following transplantation, but no longer after 1 month, although adipose tissue‐derived mesenchymal stromal cells (ASCs) could be visualized histologically even after 6 months. Despite successful long‐term in vitro GDNF overexpression and its in vivo detection shortly after cell transplantation, the 6‐OHDA model was too mild to enable sufficient evaluation of in vivo disease improvement. Still, in vivo immunocompatibility could be further examined. ASCs initially induced a pronounced microglial accumulation at transplantation site, particularly prominent in GDNF‐tASCs. However, 6‐OHDA‐induced pro‐inflammatory immune response was attenuated by ASCs, although delayed in the GDNF‐tASCs group. To further test the therapeutic potential of the generated GDNF‐overexpressing cells in a disease‐related context, a follow‐up study using a more appropriate 6‐OHDA model is needed.
We decided to evaluate the effect of treatment of diabetic foot ulcers in improving heart function by strain echocardiography than conventional transthoracic echocardiography. This prospective ...cross-sectional study included patients with diabetic foot ulcer (DFU). Conventional and two-dimensional strain echocardiography performed before and after three months diabetic foot treatment. Then, we compared the echocardiographic parameters including left ventricular ejection fraction (LV-EF), left ventricular global longitudinal strain (LV-GLS). Multivariate and univariate logistic regression analysis were performed to find which variable was mainly associated with LV-GLS changes. 62 patients with DFU were conducted. After echocardiography, all patients underwent surgical or non-surgical treatments. Three months after the treatment, LV-EF was not significantly different with its' primary values (P = 0.250), but LV-GLS became significantly different (P<0.05). In the multivariate logistic regression analysis, with the increase in the grade of ulcer, LV-GLS improved by 6.3 times. Not only the treatment of DFU helps to control adverse outcomes like infection, limb loss and morbidity but also it enhances cardiac function. Of note, strain echocardiography found to be a better indicator of myocardial dysfunction than LV-EF. These findings make a strong reason for the routine assessment of cardiac function in patients with DFU.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The prognostic value of the NIH consensus criteria for graft-versus-host disease (GVHD) is not well defined yet.
We analyzed NIH-defined GVHD in 147 acute lymphoblastic leukemia (ALL) patients.
The ...cumulative incidence of classic acute GVHD (aGVHD), late aGVHD and chronic GVHD (cGVHD) was 63%, 12% and 41%, respectively. cGVHD was subclassified as classic versus overlap syndrome in 40% versus 60% of cases. In multivariate Cox regression analysis with GVHD as time-dependent covariate, classic aGVHD grade III/IV had a negative impact on overall survival (OS) due to higher non-relapse mortality. cGVHD of any grade was associated with superior OS, which was due to lower relapse incidence. Classic cGVHD versus overlap syndrome had no differential impact. In 44 patients without GVHD after transplant who received donor lymphocyte infusions (DLI), the cumulative incidence of classic aGVHD, late aGVHD or cGVHD was 60%, 5% and 57%. Occurrence of cGVHD after DLI was associated with improved OS due to lower relapse incidence.
The NIH consensus criteria for GVHD clearly define prognostic subgroups in patients transplanted for ALL. The improved OS in patients developing cGVHD after transplant or DLI gives clear evidence for a potent graft-versus-leukemia effect in this indication.
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