Ultrasonic-assisted pulse electrodeposition of nanocrystalline nickel (NC-Ni) coatings from Watts bath on copper substrate was investigated. Direct (DC), pulsed (PC), and pulse reversed (PRC) current ...electrodeposition techniques were employed to electrodeposit NC-Ni coatings in the absence and presence of ultrasound wave with a nominal power ranging from 95 W to 200 W and their surface morphology, hardness, and crystalline microstructure were compared. We observed that as the ultrasound power increases, the cathodic efficiency and the microhardness increase, whereas the crystallite size and surface roughness decrease for NC-Ni electrodeposited by the three techniques in the same way. However, the effect of pulse waveform is dominant. The finest crystallite size (24 nm) and highest hardness (585 HV) were achieved for NC Ni coatings PC electrodeposited using an ultrasound with 200 W nominal power. It is believed that the coating produced by PC and PRC techniques develops a preferential orientation in (111) and (100) planes, respectively. The application of ultrasound wave and increasing its nominal power changes the preferential orientation of all obtained coatings to (111) planes. The corrosion behavior of NC Ni coatings, as investigated by potentiodynamic polarization and electrochemical impedance spectroscopy in NaOH solution, demonstrates the effect of nanocrystalline on the passivation and corrosion resistance of NC-Ni coatings.
•Ultrasonic-assisted pulse electrodeposition of nanocrystalline nickel (NC-Ni) coatings from Watts bath was exploited.•Effect of ultrasound wave with different nominal power ranging from 95 W to 200 W was studied.•Effect of direct, pulse and pulse-reverse current on nucleation and growth of nickel films was studied.•Increasing ultrasound power boosts cathodic efficiency and microhardness while decreasing crystallite size and surface roughness.•NC Ni coatings in NaOH solution show that corrosion behavior is influenced by crystallite size and morphology
In this article, smart control and frequency characteristics of a graphene nanoplatelets composite (GPLRC) cylindrical shell surrounded by piezoelectric layers as sensor and actuator (PLSA) are ...presented. The current structure is under an external load. For the semi-numerical method, the strain-stress relations can be determined through the first-order shear deformable theory (FSDT). For access to various mass densities as well as the Poisson ratio, the rule of the mixture is applied, although the modified Halpin-Tsai theory for obtaining the module of elasticity. The external voltage is applied to the sensor layer, while a Proportional-Derivative (PD) controller has been utilized for controlling the output of the sensor. The boundary conditions are derived through governing equations of the GPLRC cylindrical shell surrounded by PLSA using an energy method known as Hamilton's principle and finally are solved using a generalized differential quadrature method (GDQM). Apart from a semi-numerical solution, a finite element model was presented using the finite element package to simulate the response of the smart GPLRC cylindrical shell. The results created from a finite element simulation illustrates a close agreement with the semi-numerical method results. The outcomes show that the PD controller, viscoelastic foundation, slenderness factor (L/R), external voltage, and GPL's weight fraction have a considerable impact on the amplitude and vibration behavior of a GPLRC smart cylindrical shell. As an applicable result in related industries, the parameter and consideration of the PD controller have a positive effect on the static and dynamic behaviors of the structure subjected to an external load.
•Smart control and vibration analysis of a GPLRC structure covered with PLSA and under mechanical shock in the framework of GDQM are studied for the first time.•The external voltage is applied to sensor layer and a PD controller is used for sensor output control.•There is a good agreement between the results of semi-numerical method and FEM package.•The results show that PD controller, mechanical loading, applied voltage and weight fraction of GPL have significant influence on the amplitude, and frequency characteristics of a smart GPLRC cylindrical shell.
The level of socioeconomic-related inequality in physical activity in Iran is largely unknown. This study investigates socioeconomic-related inequality in poor-physical activity (PPA) among Iranian ...adults.
A total of 129,257 adult participants enrolled in the PERSIAN (Prospective Epidemiological Research Studies in IrAN) Cohort were included in this study. Physical activity of adults was measured using metabolic equivalent rates (METs). Physical activity less than 41 METs/hour/day was considered PPA. The Concentration index (C) was used to quantify socioeconomic-related inequality in PPA. Moreover, the C was decomposed to identify the relative contribution of explanatory variables to inequality in PPA.
There were significant regional variations in physical activity level among Iranian adults (29.8-76.5%). The positive value of C (0.098, 95% CI = 0.092 to 0.104) suggested that the higher concentration of PPA among higher socioeconomic status (SES) adults in Iran which was consistently observed in all cohort sites.
The higher prevalence of PPA among Iranian adults, especially, women and older adults, warrant further public health attention. Since PPA is concentrated more among the high-SES population in Iran, strategies for the promotion of physical activity should focus more on economically well-off population.
Inflammatory bowel disease (IBD), of which Crohn's disease (CD) and ulcerative colitis (UC) are the two main clinicopathological subtypes, is a group of digestive system diseases of unknown etiology. ...Risk factors for IBD are environmental factors, genetics, and immune system agents.
(MAP) is one of the most important infectious factors and a suspected cause of IBD. The present study aimed to determine the prevalence of MAP in both IBD patients and non-IBD people as well as to investigate the relationship between the presence of this bacterium and IBD.
A cross-sectional study was conducted during May-December 2017 among 146 IBD patients (32 with CD and 114 with UC) at the Motahari Clinic affiliated to Shiraz University of Medical Sciences, Shiraz, Iran. For comparison, the blood samples of 146 non-IBD volunteers (the control group) were tested for the presence of MAP using the polymerase chain reaction method (specific IS900 fragment). The data were analyzed using the SPSS software (version 19.0). The Kolmogorov-Smirnov test was used to evaluate the normal distribution of variables. The χ2 test was used to compare the qualitative variables between the groups.
MAP was present in 104 (71.2%) IBD patients out of which 24 (75%) had CD and 80 (70.2%) had UC. In the control group, MAP was present in 63 (43.2%) non-IBD volunteers. There was a significant association between the presence of IBD and MAP (P<0.001).
A high prevalence of MAP was observed in the South of Iran. MAP DNA was detected in the blood samples of CD and UC patients as well as non-IBD volunteers. The high prevalence of MAP indicated a possible role of MAP in stimulating IBD.
Purpose: This research investigated the development of short hairpin RNA (shRNA) molecules designed to target specific regions of the HRSV M and F genes. The study aimed to assess the therapeutic ...potential of these shRNAs and evaluate the effectiveness of Tat peptide-mediated delivery in enhancing their functionality. Methods: To investigate the therapeutic potential of short hairpin RNA against HRSV, we acquired isolates from pediatric patients experiencing respiratory illness. These isolates were then cultured in human epidermoid carcinoma cells (HEp-2). To target the M and F genes of HRSV, we constructed plasmids expressing shRNAs. We further investigated the Tat peptide as a facilitator for shRNA plasmid delivery. The cytotoxicity of ribavirin, shRNA constructs, and control agents was assessed using the MTT assay. Next, we compared the transfection efficiency of Tat peptide-mediated shRNA delivery with that of lipofectamine 3000™. Finally, real-time PCR was employed to quantify HRSV replication in the treated cells. Results: Our study successfully demonstrated that Tat peptide-mediated delivery of shRNA plasmids significantly suppressed the expression of the M and F genes of HRSV compared to lipofectamine 3000™. This suppression was evident in both short-term experiments and scenarios involving stable shRNA expression. Furthermore, the combination of ribavirin with shRNA treatment resulted in a substantial reduction in viral load. Notably, the most pronounced antiviral effect was observed when both shRNAs were employed simultaneously. Conclusion: Our findings suggest that Tat peptide-mediated delivery of shRNA plasmids holds significant potential for achieving stable suppression of HRSV genes. This approach warrants further investigation as a potential gene therapy strategy for HRSV. By demonstrating promising results in vitro, this study highlights the need for future in vivo studies to comprehensively evaluate the therapeutic potential of this approach in a clinical setting.
Salmonella enterica serovar typhimurium is one of the important worldwide health issues. The hilA gene encodes a transcriptional activator that regulates expression of the majority of the genes ...responsible for the Salmonella invasive phenotype. In the present study, PCR was performed using our designed primers for amplification of upstream and downstream regions of Salmonella typhimurium hilA gene. Each DNA fragment was T/A-cloned into pGEM-T easy vector and then sub-cloned into pET32 expression vector together with Kanamycin resistance gene. The recombinant plasmid was transformed into bacteria (Salmonella typhimurium) using electroporation. The hilA-Knockout mutant was characterized to evaluate the predicted role of the hilA gene in virulence. Quantitative RT-PCR was carried out to study the impact of hilA knock out on the expression of downstream genes including invF and invA. We confirmed the successful preparation of hilA gene construct (pET32-up-kan-down) followed by the efficient electroporation of the construct to bacterial cells. The homologous recombination resulted in the hilA confirmed by PCR. We demonstrated that hilA knockout leads to attenuation of invA and invF genes expression. The hilA knockout strain may be useful for the development of efficient vaccines against the Salmonella typhimurium.
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