فهرست مطالب مهدی بهزاد

Cytokine production was shown to be changed in Type 2 diabetes mellitus (T2DM). Nonetheless, the relationship of pro-inflammatory interleukin (IL)-32α with anti-inflammatory IL-35 and transforming growth factor (TGF)-β is unclear in T2DM. The present study aimed to evaluate the IL-32α, IL-35, and TGF-β levels produced by peripheral blood mononuclear cells (PBMCs) in patients compared to healthy controls (HCs). Correlations between the IL-32α and IL-35 and TGF-β, as well as between those cytokines and paraclinical parameters [(fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c), GFR, albumin, and creatinine)] were assessed.

Blood samples were taken from 38 patients and 38 HCs. The PBMCs from each donor were isolated with the ficoll method and cultured with in vitro stimulator for four days. The production of IL-32α, IL-35, and TGF-β in culture supernatants was determined with ELISA. Paraclinical parameters were evaluated by standard laboratory methods.

High levels of IL-32α and low levels of IL-35 were found in patients compared to in HCs (P=0.006; P<0.001). A negative correlation between IL-32α and IL-35 was detected in patients (P<0.001). IL-32α was positively correlated with FPG and HbA1c (P=0.002, P=0.005), whereas IL-35 was negatively correlated with them in patients (both P<0.001). No correlations were detected between the cytokines and BMI, GFR, albumin, and creatinine, as well as between the TGF-β levels.

Increased IL-32α but diminished IL-35 production are linked with each other and with the glucose metabolism parameters in T2DM. It seems that IL-32α and IL-35 have a potential role in T2DM pathogenesis.

This paper proposes a remaining useful life (RUL) prediction method that uses the peak of the vibration acceleration signal as an appropriate feature to indicate the degradation process in the rolling element bearings (REBs). In the first step, this feature is transformed into a stationary time series using logarithmic transformation. That is because the long short-term memory neural network (LSTM-NN) works better with the stationary time series. Training the LSTM-NN is performed by this stationary time series as the input and the response is the training time series with values shifted by one time step. Therefore, the LSTM-NN learns to predict the value of the next time step at each point. In other words, to forecast the values of multiple time steps in the future, previous forecasted steps are used as inputs. Next, the values of the future time steps are returned to the main non-stationary form to predict the trend of the peak in the future. Importantly, new measured data can be used to perform new predictions. For this purpose, for every new measured data, the LSTM-NN repeats the mentioned steps and generates a new trend. This algorithm is a trend-dependent method. Therefore, an REB that has a slow degradation stage in its life, which is corresponding to the growth and expansion of defects in REBs, is appropriate to be studied by this algorithm. This method is implemented on two REBs from PRONOSTIA accelerated-life test which have been used by many researchers in the literature. According to the prediction results, the remaining time that peak amplitude trend touches a given threshold is provided. If this threshold is a criterion for the end of life (EoL), this method can be used to determine the RUL. The performance of the proposed method has been evaluated and the presented results are in a good agreement with the experimental data.

Early fault detection of the rolling element bearings has a very important role in increasing the reliability of rotating machines.It leads to better decision-making for maintenance activities.  In recent decades, the shock pulse method has been developed to detect faults in the early stage of rolling element bearings degradation. In this paper, the accuracy of the remaining useful life estimation using extracted features from vibration signals and that from the shock pulse method are compared. In this regard, a set of accelerated life tests on rolling element bearings were designed and performed. Both shock pulse signals and vibration signals of the under-test rolling element bearings were recorded. Then two models based on feed-forward neural-network are developed to predict the remaining useful life of rolling element bearings. In the first model, only extracted features from vibration signals are fed for remaining useful life prediction. In the second model, the extracted features from shock pulse method are fed too. The results show that using shock pulse method-based features improves the accuracy of remaining useful life estimation. Also, using the health indicators extracted from vibration analysis and shock pulse method leads to a better estimating of the degradation behavior.

The increased response of T helper (Th) 22cells might be involved in thepathogenesis ofType 2 Diabetes Mellitus (T2DM). The present study aimed to investigate the transcription factor of Th22 cells (aryl hydrocarbon receptor [AHR]) and interleukin 22 (IL-22) in CD4+ T cells as well as the impact of oral empagliflozin treatment. The correlation between the aforementioned factors and clinical parameters was also determined among the patients.

In this case-control study, 50 patients under the treatment of metformin and gliclazide were divided into two equal groups, including the patients receiving empagliflozin (EMPA+) and not receiving empagliflozin (EMPA, as the control group). The peripheral blood CD4+ T cells were isolated on the initiation day of the study and after 6 months of therapy, and the gene expression levels of AHR and IL-22 were evaluated by real-time polymerase chain reaction. In addition, the production of IL-22 after activation was measured using enzyme-linked immunosorbent assay.

The levels of fasting plasma glucose and hemoglobin A1c diminished in the EMPA+ group after empagliflozin therapy, compared to those reported at the baseline (initiation day; P<0.001 and P=0.04). The gene expression level of IL-22 and production of IL-22 significantly reduced after 6 months of empagliflozin therapy (P=0.011 and P=0.001). A significant positive correlation between IL-22 production and its gene expression with AHR as well as between fasting plasma glucose and hemoglobin A1c was observed in the EMPA+ patients after therapy (P˂0.05).

In addition to antidiabetic effects, empagliflozin has anti-inflammatory impacts on the immune system, especially on Th22 cell-related factors.

The alterations of the adaptive immune system are involved in type 2 diabetes mellitus (T2DM) pathogenesis. T helper 1 (Th1) cells or CD4+ T cells are the pro-inflammatory components of adaptive immunity with the main feature of interferon-gamma (IFN-γ) secretion. The aim of this study was to evaluate the percentage of IFN-γ, assess the expression of related-genes in CD4+ T cells, including T-bet, IRF1, RUNX3, and NFκB, and determine the correlation between them and clinical parameters in T2DM patients.

In this case-control study, peripheral blood CD4+ T cells were isolated from 40 patients and 40 healthy controls (HCs). The percentage of IFN-γ secreting CD4+ T cells was assessed using flow cytometry, and the related-genes were evaluated using real-time polymerase chain reaction.

The percentage of IFN-γ secreting CD4+ T cells significantly increased in the patients in comparison to that of the HCs (P<0.001). The expression levels of IRF1 and NFκB were higher in the patients in comparison to those of the HCs (P=0.02 and P<0.001, respectively). A significant positive correlation between IFN-γ secreting CD4+ T cells and both IRF1 and NFκB was observed in the patients (P=0.001 and P=0.002, respectively). There was a significant positive correlation between IFN-γ secreting CD4+ T cells, IRF1, and NFκB with fasting plasma glucose and hemoglobin A1c in the patients (P<0.001).

Due to the increased response of Th1 cells (the production of IFN-γ and expression of related genes) in the patients and existing correlation between them and plasma glucose level, it seems that these inflammatory factors are involved in T2DM pathogenesis, and the use of IFN-γ pathway antagonists could be considered a novel therapeutic approach.

Er2Ti2O7 pyrochlore structure was successfully prepared by solid-state method. The prepared microstructure mixed-metal oxide was characterized by XRD, SEM, EDX, FT-IR and BET. X-ray powder diffraction revealed a Cubic crystal system with Fd-3m space group for Er2Ti2O7. The morphology and mean particle size of the sample was characterized by the scanning electron microscope. The elemental analysis or chemical characterization of the sample was determined by Energy Dispersive X-ray microanalysis. The absorption bands between the A and B sites in the pyrochlore structure were confirmed by Fourier transmission infrared spectra in (400–4000 cm-1) range. The specific surface area and the pore size distributions of the sample were calculated using Brunauer–Emmett–Teller (BET) method and Barrett–Joyner–Halenda (BJH) method respectively. The complex has been used as a catalyst for epoxidation of cyclooctene with TBHP (tert-butyl hydroperoxide). Various parameters including catalyst amount, solvent type and amount, oxidant/substrate ratio and time have been optimized and almost. Considerable catalytic activity and high epoxide selectivity has been found.

Immune-mediated polyneuropathy is divided into acute and chronic categories named as Guillain Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy based on the course of the disease. Although the basic mechanism of these conditions has not been yet clarified, genes that regulate immune responses are putative contributors in their development. The aim of this study was to compare the blood expression level of IL-34 gene between patients with GBS and healthy individuals.

In this case-control study, blood samples were collected from 53 patients with GBS (i.e., 33 chronic patients and 20 acute patients) and 40 healthy individuals. Gene expression levels in the studied groups were measured using the real-time polymerase chain reaction technique. Finally, statistical analysis was performed using SPSS software (version 16) at a significance level of < 0.05 was.

The patient group consisted of 36 (67.93%) males and 17 (32.07%) females. In addition, the healthy control group included 27 (67.5%) males and 13 (32.5%) females. The results showed a significant increase in IL-34 expression in the GBS patients, compared to that in the control group.

The findings of the present study revealed an increase in IL-34 gene expression in patients with GBS. Accordingly, it seems that IL-34 gene has an important role in the pathogenesis of this disease.

In recent years, using the offshore platforms in deep water locations is increasing for extracting oil and renewable energy. In such places, the harsh environmental forces of wind and sea waves cause vibration and instability for the structure. One of the optimized solutions for the reduction of vibration is installing the heave plate at the end of the platform column. These plates induce damping and added mass in motion equations of the structure. Therefore, deriving of the hydrodynamic coefficients is a requirement for obtaining the platform response accurately. The present paper is a comprehensive study on published researches and computational methods of the hydrodynamic coefficients and their corresponding effective parameters in a classified order. In the following, the drawbacks are pointed and new suggestions for future research are expressed.

In this work, Kanemite was prepared from rice husk ash and used as a heterogeneous base catalyst for production of biodiesel from sunflower oil. The catalyst was characterized by PXRD, FESEM and FT-IR. The transesterification conditions, such as the catalyst dosage, molar ratio of methanol to oil, reaction temperature and reaction time were investigated and optimized. The results revealed that by a catalyst loading of 5 wt. %, methanol to oil ratio of 24:1, reaction temperature of 65 °C and reaction time of 4h, conversion of biodiesel reached 97.2%. Moreover, the catalyst could be reused up to five cycles under the optimum reaction conditions without significant loss of product yield.

Instability and vibration of offshore platforms in harsh environmental force can be reduced by installing heave plates underneath of platform columns. Effect of parameters such as excitation Frequency and boundaries are investigated experimentally in this research. On the other hand, regarding to the published papers, both the added mass and damping gradually increase versus vibration amplitude for a rigid heave plate. It is predicted that using a combination of a rigid disk in center and an elastic plate around it can increase the damping.  It is generally observed from forced harmonic vibrations that frequency can decrease and increase hydrodynamic coefficients respectively near free surface and floor wall. Furthermore, frequency has considerable effect on the hydrodynamic coefficients of a rigid heave plate with large elastic part around it. This definitely depends on the excited mode shapes of the elastic edge.

In this work, KTiOPO4 nanoparticles were synthesized by both hydrothermal and coprecipitation methods and studies were carried out on their structural and optical properties. To study the physical properties of samples, XRD, FT-IR, UV-Vis and FE-SEM analyses were used. Hydrothermal method, using different starting materials, resulted to the production of finner particles (9.6 nm and 12.54 nm) compared with nanoparticles (34.65 nm) produced by coprecipitation method.

Strain gage mounted on the surface of the shafts with specified directions are one of the common methods for measurement of the torsion in shafts. The most critical problem in utilization of this method, particularly in the online monitoring of torsional vibration and instantaneous torque in rotary systems, is due to its signal transfer process. In this paper, a simple, practical and feasible method is introduced based on the usage of an ::union::ized fluid medium with adequate electrical conductivity, encapsulated in a cylindrical connector aligned along the shaft, with a rotating chamber (rotor part) and a stationary one (stator part). In this method, there is no need for installation of the power supply on the shaft and both of the supply voltage and the generated electrical signals are transferred via the ::union::ized fluid. Simplicity in design and high signal to noise ratio, may candidate this method for torsional vibration measurement. The efficiency of the measurement system is examined on a test setup, for static and dynamic (transient) torsions. Moreover, the applicability of the device is observed on a rotating shaft.

Bi2O3 nanomaterials doped with Eu3 and Nd3 ions have been synthesized by a simple hydrothermal process at 180 °C for 48 h. Bi(NO3)3.5H2O and KOH were used as raw materials. The as-prepared materials were characterized by X-ray diffraction (XRD). The data showed that the doped Bi2O3 materials were crystalized in a monoclinic crystal structure with space group of P21/c and cell parameters of a=5.8499 Å, b=8.1698 Å and c=7.5123 Å. The morphology of the obtained nanomaterials was investigated by field emission scanning electron microscope (FESEM). The morphology was remained unchanged after doping the rare elements into Bi2O3. However, different morphology of the compounds was achieved. The FESEM images showed that the materials were composed of micro-nano rods, nanoparticles and flower structures. Elemental analyses of the doped nanomaterials were performed by energy-dispersive X-ray spectrometry (EDS). Also cell parameter refinements and interplanar spacing (d) of the obtained materials were investigated.

In this study, the adsorption of active carbon derived from waste sesame seeds coated with polyvinyl alcohol (AC/PVA) was investigated for removing red 198 and blue 19 reactive dyes from textile effluents. The batch process was carried out to identify such parameters as pH, adsorbent dose, contact time, and initial dye concentration involved in the dye removal adsorption capacity of AC/PVA. Also, batch kinetic and isotherm experiments were conducted. Results indicated that the maximum dye removal was obtained in an acidic pH over 90 min of contact time and that adsorption rates followed the pseudo-second-order kinetics. Blue and red dye concentrations were determined using the spectrophotometric method at 590 and 517 nm, respectively. It may be concluded that AC/PVA is capable of removing blue and red reactive dyes and can be used as an efficient, cheap, and accessible adsorbent for treating textile effluents.

Nanostructured CeO2 powders were synthesized via a series of hydrothermal and solution precipitation methods. Three different hydrothermal methods including 1:2 and 1:1 Bi: Ce molar ratios at 180 °C for 48 h (S1 and S2، respectively) without calcinations; and 2:1 Bi: Ce molar ratio at 180 °C for 48 h with calcinations (S3) were performed successfully for the synthesis of the target nanomaterials. Two different solution precipitation methods i. e. 1:1 Bi: Ce molar ratio at 80 °C for 40 min without and with calcinations (S4 and S5، respectively) were also used for the synthesis of CeO2 nanoparticles. Bi (NO3) 3 and (NH4) 2Ce (NO3) 6 were used as raw materials. The synthesized materials were characterized by powder X-ray diffraction (PXRD) technique. CeO2 crystallized in a cubic crystal structure with cell parameters of a=b=c= 5. 412 Å. The morphologies of the synthesized materials were studied by field emission scanning electron microscopy (FESEM). The technique showed that the morphology of the synthesized nanomaterials were strongly dependent on the synthetic procedure.

The catalytic activity of KOH/borax as homogeneous mixed catalyst was evaluated for the synthesis of biodiesel via transesterification of sesame oil extracted from waste sesame seeds with n-hexane. The effects of catalyst loading، methanol to oil ratio، temperature and reaction time in transesterification were investigated. The highest yield of 87% for biodiesel production was obtained at optimized conditions including 0. 4 wt. % KOH and 10 wt. % Na2B4O7. 10H2O of mixed catalyst loadings، methanol to oil molar ratio of 8:1، reaction time of 2. 5 h and reaction temperature of 65 ˚C.

Computer circuit boards (CCBs) are valuable because of their precious metal contents. In this regard، the recovery of gold from CCBs has attracted great interest. In this work، we report the recovery of gold from CCBs with different reductants. The CCBs were first crushed mechanically to obtain particles with sizes less than 0. 1 mm. The powders were then leached with nitric acid to remove undesired metals. The remaining was then treated with aqua regia to dissolve gold ion. The dissolved gold was then precipitated from the leachate with hydrazine، ferrous sulfate or oxalic acid and the effect of these reductants on the recovery of gold was studied. We were able to recover more than 99% of gold from CCBs with purity of about 99. 5%.

Polythiophene is a standout amongst the most valuable sorts of the conducting polymers that hold numerous odd physical and electrical lands for instance dissolvability، electrical conductivity and develop the ecologically and thermally stable materials. Distinctive assembling techniques have been advanced for conducting polymer nanostructures and near them، template method is a facile and encouraging method. Nanostructured polythiophene was prepared by soft-template method in the vicinity of sodium dodecyl sulfate (SDS) as an anionic surfactant، triethanolamine (TEA) as a co-surfactant and ammonium persulfate (APS) as an oxidant in aqueous medium. Moreover، the chemical structure of fabricated nanostructured polythiophene was investigated by fourier transform infrared (FTIR) spectroscopy. The morphology and particle size of the product was studied by scanning electron microscope (SEM) and atomic force microscope (AFM). Furthermore، dispersion state of nanostructured polythiophene in organic solvents was studied after being dried. The results indicate that nano-product has a favorable fiber-like-structure with a diameter in the range of 85–100 nm.