Microstructural Evolutions and its Impact on the Corrosion Behaviour of Explosively Welded Al/Cu Bimetal

In this study, the microstructural evolutions and corrosion resistance of aluminium/copper joint fabricated through explosive welding process have been thoroughly investigated, while stand-off distance was variable. Microstructural analyses demonstrate that, regardless of grain refinement in the welding boundary, increasing the stand-off space is followed by a higher thickness of the localized melting pool. X-Ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) analyses recognized the binary intermetallic layers as a combination of Al2Cu and AlCu. Polarization and electrochemical impedance spectroscopy (EIS) corrosion tests revealed that a higher stand-off distance resulted in the increment of corrosion potential, current rate, and concentration gradient at the interface owing to the remarkable kinetic energy of the collision, which impaired corrosion resistance

Pharmacokinetic Parameters and Over-Responsiveness of Iranian Population to Propranolol

Purpose: Propranolol is the most widely used treatment for cardiovascular diseases. Dosage range in our patients is usually less than the amount mentioned in references. The aim of the present study was to clarify whether pharmacokinetic differences are able to justify the need for the fewer doses in our patients or not. Methods: Twenty healthy volunteers (10 male) at heart center of Mazandaran University of Medical Sciences were studied. Samples of blood were collected before a single oral dose (40 mg) of Propranolol. Blood samples were taken up to 9 hours after dose. Total plasma concentration of Propranolol was measured by HPLC. Population Pharmacokinetic analysis was performed using population pharmacokinetics modeling software P-Pharm. Results: The mean value for oral plasma clearance (CL/F) was 126.59 ml/hr. The corresponding values for apparent volume of distribution (V/F), t1/2 beta, maximum blood concentration (C max), and time to reach the maximum blood concentration (T max) were 334.12 Lit, 1.98 hr, 40.25 ng/ml, and 1.68 hr, respectively. The observed mean values of V/F of propranolol in the present study were comparable with those reported in the literature. However, the mean values of CL/F of propranolol in current study was significantly higher than those reported in other population (P-value<0.001). Conclusion: This study has confirmed that the pharmacokinetic differences are not able to justify over-responsiveness of Iranian population to propranolol. Pharmacodynamic differences in responding to beta blocker drugs by Renin secretion or having a different sensibility to beta receptors might play a role in making our population have a different response to propranolol

Nose-to Brain Direct Delivery of Nanodrug Formulations in Treatment of Neurological Disorders: A Review Study

Global prevalence of neurological disorders such as Parkinson's disease, Alzheimer's disease, epilepsy, and multiple sclerosis is steadily increasing, but, there is still no effective delivery system to deliver therapeutic amounts of drug into the central nervous system (CNS). The blood-brain barrier ​​is the major component to control the entrance of drugs into the brain. Recent studies introduced intranasal drug delivery as a suitable method of drug delivery for bypassing blood-brain barrier and treatment of neurological diseases. The nasal route has been repeatedly examined in several preclinical models to investigate the delivery of drug to the brain via nanoparticles. Among various carriers utilized for drug delivery via nasal route, chitosan is widely used due to being effective in modulating drug charge. Key features of drug delivery systems through nasal route include easy drug delivery, higher stability in nasal cavity, increased penetration ability of drugs through nasal epithelium, and decreased drug metabolism. The present review investigated novel nano-formulations for drug delivery via nose to brain in treatment of major neurological disorders. In preclinical studies, intransaal nanoparticle-based drug delivery systems are found to be more promising, effective, and targeted. However, more preclinical studies are needed to confirm their non-toxicity and beneficial effects

Frequencies of two CYP2C19 defective alleles (CYP2C19*2, and *3) among Iranian population in Mazandaran Province

Background: Cytochrome P450 2C19 (CYP2C19) is a polymorphically expressed enzyme that shows marked interindividual and interethnic variation. CYP2C19*2 and CYP2C19*3 are the most frequently identified defective alleles in Orientals and Caucasian poor metabolizers (PM). The aim of this study was to investigate the frequencies of CYP2C19*1, CYP2C19*2 and CYP2C19*3 alleles and CYP2C19 genotypes in the Mazandarani ethnic group among Iranian Population.  Materials and Methods: The study was conducted in 103 unrelated healthy volunteers. DNA was extracted from leucocytes and analyzed by the PCR-RFLP protocol. The PCR product was digested with restriction enzymes (SmaI and BamH1) and then separated electrophoretically using polyacrylamide gel.. Results: Of the alleles tested, CYP2C19*1, and CYP2C19*2, but not CYP2C19*3, were detected. The frequencies for CYP2C19 alleles *1, *2, and *3 were 91%, 9.0%, and 0.0%, respectively. The frequencies of CYP2C19 genotypes *1/*1, *1/*2, *1/*3, *2/*2, *2/*3 and *3/*3 were 84%, 14%, 0.0%, 2.0%, and 0.0%, respectively. Conclusion: The result of the present study showed that the two inactive alleles of CYP2C19 accounted for 9.0% of CYP2C19 alleles in our sample versus 8.8 - 40.1% reported in other populations. The frequencies of the studied alleles resulted significant differences between our sample and African and Eastern Asian populations

Derivation of attenuation map for attenuation correction of PET data in the presence of nanoparticulate contrast agents using spectral CT imaging

Objective: Uptake value in quantitative PET imaging is biased due to the presence of CT contrast agents when using CT-based attenuation correction. Our aim was to examine spectral CT imaging to suppress inaccuracy of 511 keV attenuation map in the presence of multiple nanoparticulate contrast agents. Methods: Using a simulation study we examined an image-based K-edge ratio method, in which two images acquired from energy windows located above and below the K-edge energy are divided by one another, to identify the exact location of all contrast agents. Multiple computerized phantom studies were conducted using a variety of NP contrast agents with different concentrations. The performance of the proposed methodology was compared to conventional single-kVp and dual-kVp methods using wide range of contrast agents with varying concentrations. Results: The results demonstrate that both single-kVp and dual-kVp energy mapping approaches produce inaccurate attenuation maps at 511 keV in the presence of multiple simultaneous contrast agents. In contrast, the proposed method is capable of handling multiple simultaneous contrast agents, thus allowing suppression of 511 keV attenuation map inaccuracy. Conclusion: Attenuation map produced by spectral CT clearly outperforms conventional single-kVp and dual-kVp approaches in the generation of accurate attenuation maps in the presence of multiple contrast agents. © 2014 The Japanese Society of Nuclear Medicine

Evaluation of Welding Parameter's Effects on Corrosion Behavior of Bronze-Carbon Steel Dual-Layer Explosion Welded Joint at Salt Enviroment

<div><p>In the current investigation, corrosion behavior and microstructural variations of explosion-welded joint of bronze-carbon steel dual-layer plates were studied. The resultant curves of potentiodynamic's polarization tests demonstrated that the lowest corrosion rate was related to the sample with maximum explosive load thickness, and the highest corrosion speed was for the sample with minimum standoff distance. EIS test results of welded samples were indicative of creating a passive layer at the beginning of immersion process which showed that the polarization resistance has been reduced by increasing of explosive load thickness. So, the corrosion mechanism included two stages; at the beginning of immersion, for the samples with the lower thickness of explosive load, a passive layer would be created around the component due to higher concentration gradient and then, by removing of this layer, the galvanic couple determines the corrosion rate.</p></div

Detection of CYP2C18 m1, and m2 Alleles within an Iranian Population (Mazandaran) Using Denaturing High-Performance Liquid Chromatography (DHPLC)

Background: Genetic polymorphisms of cytochrome p450 in humans are the main cause of differences in the metabolism. The allele and genotype frequencies of CYP2C19 and CYP2C9 have been studied in some Iranian populations. The aim of present study was to examine the frequencies of CYP2C18m1, and CYP2C18m2, alleles in the Mazandarani ethnic group among Iranian Population. Materials and Methods: In this study, genomic DNA was extracted from leucocytes of one hundred unrelated healthy volunteers. The prevalence of the common variants CYP2C18 m1 and m2 alleles were studied by using high fidelity polymerase chain reaction (HF-PCR) - DHPLC methods. Results: The frequency of CYP2C18 m1 and m2 alleles were 0.0% and 3.0%, respectively. CYP2C18 genotypes wt/wt, wt/m1, wt/m2, m1/m1, m1/m2, and m2/m2 frequencies were 97 %, 0.0 %, 3.0%, 0.0 %, 0.0%, and 0.0%, respectively. Conclusion: The result of the current study shows that impaired CYP2C18 activity in 03% of our sample population may decrease extra hepatic metabolism of some important drugs such as Phenytoin. It may also affect transdemal delivery of drug substrate for this isoenzyme

Viability of Probiotic Bacteria in Yogurts Produced in Mazandaran Province Exposed to Simulated Gastrointestinal Conditions

Background and purpose: Production of functional foods is one of the most important achievements in food industry and using these products provides the convergence of two important events in life; namely receiving nutrients from the diet and promoting health for consumers at the same time. This study aimed to verify the viability of microorganisms and stability of these microorganisms in digestive conditions of the body in order to benefit from the claimed properties of these products. Materials and methods: In this experimental study, 14 samples of probiotic yogurts were collected from three dairy factories in Mazandaran province in summer 2020. The test method consisted of three main steps; determining the viability of probiotic bacteria in the samples over time, then simulating the conditions of the gastrointestinal conditions, including pH changes and exposure to pepsin and bile salts, and finally, evaluating the resistance of microorganisms after passing the conditions of gastric and intestinal simulated condition. Statistical analysis was performed using SPSS. Results: In the study of viability of Bifidobacterium and Lactobacillus, a significant difference was observed between the mean number of colonies both at different weeks and different pH levels (P<0.05). Yet, the number of probiotic bacteria remained within acceptable standard range (106 cfu/g) over time and did not show a considerable reduction even after passing the acidic and alkaline conditions and tolerating the simulated digestive conditions. Conclusion: According to this study, if strains (probiotic bacteria) resistant to acid and bile are selected and also suitable environmental conditions are used, consumption of probiotic yogurts can be of great benefit in improving the health of consumers