Applying the genetic algorithm for determination electrospinning parameters of poly vinylidene fluoride (PVDF) nano fibers: theoretical & experimental analysis

Poly Vinylidene Fluoride (PVDF) because of its piezoelectric properties has been applied in different applications such as smart textiles, medical application and membranes for energy harvesting. It was declared that nanofibres diameters and electrospinning parameters could be enhanced the piezoelectric properties of these materials. The main objective of this paper is applying the Genetic Algorithm (GA) to determine the optimum condition of solution parameters and processing conditions based on the desired diameter size of PVDF fibers to produce the fibers without any structural faults. In this method, The Fitness function was determined by a simple analytical model presented by Fridrikh. Toward approving the GA results the experimental tests were done. the effect of four parameters such as flow rate of the polymer solution, electrospinning voltage, electrospinning distance and polymer concentration on the fiber formation and fiber diameter size of electrospun PVDF fibers have been explored by Scanning Electron Microscopy (SEM) to attest the accuracy of the model. Assessment of experimental and theoretical results show that electrospinning parameters determined by GA method leads to achieve desire fiber diameters. Because of time and energy consuming of electrospinning process, the GA method may be useful to achieve desired fiber diameter by determining electrospinning parameters for polymers prior to fiber production

The effect of aerobic exercise and barley β-glucan on blood glucose, body composition and blood pressure of diabetic women

Background: The incidence of type 2 diabetes increases with aging, unhealthy diets, obesity and sedentary lifestyles. The aim of this study was to investigate the combinational effect of a 12-week aerobic exercise and barley β-glucan (BBG) on blood glucose, body composition and blood pressure in women with type 2 diabetes. Materials and Methods: In this semi-experimental study, 24 women with the mean age of 49 years and a blood glucose level of 110-280 mg/dl were purposefully selected and randomly divided into three groups: a) group of aerobic exercise with diet (n=8), b) diet group (n=8) c) control group (n=8). The diet group consumed one barley bread, containing 4 g of β glucan, each day for 12 weeks. The group of aerobic exercise, who was on diet, participated in a progressive walking program with the intensity of 60-70 of maximal heart rate in addition to diet program (barley bread). Blood glucose, weight, fat percentage, and systolic and diastolic blood pressure levels were measured in pre-and post-training. Results: Results showed a significant decrease in the blood glucose level in the experimental groups compared to the control group, while no major changes were observed in body composition and blood pressure. Conclusion: It seems that the combined program (aerobic training with diet) or consumption of β-glucan alone can decrease blood glucose in patients with diabetes

The effect of silver nanoparticles on composite shear bond strength to dentin with different adhesion protocols

In Dentistry, restorative materials and oral bacteria are believed to be responsible for restoration failure. To make long-lasting restorations, antibacterial agents should be made. Inorganic nanoparticles and their nano composites are applied as good antibacterial agents. Objective The purpose of this study was to investigate the effect of silver nanoparticles on composite shear bond strength using one etch and rinse and one self-etch adhesive systems. Material and Methods Silver nanoparticles were prepared. Transmission electron microscope and X-ray diffraction were used to characterize the structure of the particles. Nanoparticles were applied on exposed dentin and then different adhesives and composites were applied. All samples were tested by universal testing machine and shear bond strength was assesed. Results Particles with average diameter of about 20 nm and spherical shape were found. Moreover, it was shown that pretreatment by silver nanoparticles enhanced shear bond strength in both etch and rinse, and in self-etch adhesive systems (p≤0.05). Conclusions Considering the positive antibacterial effects of silver nanoparticles, using them is recommended in restorative dentistry. It seems that silver nanoparticles could have positive effects on bond strength of both etch-and-rinse and self-etch adhesive systems. The best results of silver nanoparticles have been achieved with Adper Single Bond and before acid etching

A cephalometric comparison of twin block and bionator appliances in treatment of class II malocclusion

Class II malocclusion is one of the most common orthodontic problems. In cases of class II malocclusion with mandibular deficiency, functional appliances often are used with the intent of stimulating mandibular growth. Bionator and twin block are two of the more popular functional appliances. The aim of this study was to compare the treatment outcomes of these two appliances using cephalometric radiographs. Cephalometric radiographs of 33 patients who had class II division I malocclusion, before and after treatment were digitalized. The mean changes in twin block and bionator groups were compared using independent t test. Twin block and bionator showed no statistically significant differences in cephalometric parameters except for ANB, NA-Pog, Basal and Ar-Go-Me angles. There were no statistically significant differences in dentoalveolar and mandibular position between twin block and bionator (p>0.1). Twin block was more efficient in inhibition of forward movement of maxilla (p<0.1)

The Probable Effect of Irrigation Solution and Time on Bond Strength to Coronal Dentin: An In Vitro Evaluation

Introduction: The aim of this study was to evaluate the effect of root canal irrigants on the microtensile bond strength of 2-step self-etch adhesive to dentin. Methods and Materials: In this study 36 sound extracted human third molars were used. After grinding 3 mm of occlusal surface, teeth were randomly divided into 6 groups based on irrigation material naming normal saline, 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) and also irrigation time (5 or 30 min). Next, teeth were restored with Clearfil SE bond adhesive resin system and Z250 composite. The teeth were then thermo cycled by thermo cycling machine, for 500 cycles between 5º and 55ºC with 60 sec dwell time and 12 sec transfer time. All samples were sectioned into bucco-lingual slabs. The sections were submitted to the micro tensile testing machine at a crosshead speed of 0.5 mm/min until fracture. Data was analyzed using the one-way ANOVA test with the level of significance set at 0.05. Results: Irrigation with normal saline, 5.25% NaOCl and 2% CHX for 5 or 30 min did not significantly change the microtensile bond strength of adhesive to dentin (P=0.729 for time and P=0.153 for material). However the maximum and minimum microtensile bond strength was attributed to normal saline (44.13 N) and NaOCl (31.29 N) groups, respectively. Conclusion: Iirrigation solution and time have no influence on microtensile bond strength of two-step self-etch adhesive to coronal dentin.Keywords: Bond Strength, Dentin, Irrigation Solution

Electrospun nanofibers for efficient adsorption of heavy metals from water and wastewater

Heavy metals (HMs) are persistent and toxic environmental pollutants that pose critical risks toward human health and environmental safety. Their efficient elimination from water and wastewater is essential to protect public health, ensure environmental safety, and enhance sustainability. In the recent decade, nanomaterials have been developed extensively for rapid and effective removal of HMs from water and wastewater and to address the certain economical and operational challenges associated with conventional treatment practices, including chemical precipitation, ion exchange, adsorption, and membrane separation. However, the complicated and expensive manufacturing process of nanoparticles and nanotubes, their reduced adsorption capacity due to the aggregation, and challenging recovery from aqueous solutions limited their widespread applications for HM removal practices. Thus, the nanofibers have emerged as promising adsorbents due to their flexible and facile production process, large surface area, and simple recovery. A growing number of chemical modification methods have been devised to promote the nanofibers\u27 adsorption capacity and stability within the aqueous systems. This paper briefly discusses the challenges regarding the effective and economical application of conventional treatment practices for HM removal. It also identifies the practical challenges for widespread applications of nanomaterials such as nanoparticles and nanotubes as HMs adsorbents. This paper focuses on nanofibers as promising HMs adsorbents and reviews the most recent advances in terms of chemical grafting of nanofibers, using the polymers blend, and producing the composite nanofibers to create highly effective and stable HMs adsorbent materials. Furthermore, the parameters that influence the HM removal by electrospun nanofibers and the reusability of adsorbent nanofibers were discussed. Future research needs to address the gap between laboratory investigations and commercial applications of adsorbent nanofibers for water and wastewater treatment practices are also presented

Effect of Premedication with Indomethacin and Ibuprofen on Postoperative Endodontic Pain: A Clinical Trial

Introduction: Post-endodontic pain is one of the main problems for both patients and dentists. The purpose of this study was to compare the effectiveness of premedication with indomethacin and ibuprofen for management of postoperative endodontic pain. Methods and Materials: In this clinical trial, mandibular molars with irreversible pulpitis were endodontically treated in 66 patients. The medicines were prepared similarly in the form of capsules containing 400 mg ibuprofen (group A), 25 mg indomethacin (group B) and placebo (group C). The patients were given one capsule 1 h before the start of treatment. Patients recorded their pain measured by a visual analogue scale (VAS) at medication time, during treatment and 8, 12 and 24 h after treatment. The data were analyzed using the chi-square, repeated measures ANOVA, paired t-test, Tamhane and Pearson correlation coefficient. Results: Ibuprofen and indomethacin significantly reduced the postoperative pain in comparison with placebo during treatment and 8 h after treatment; however, there were no significant differences between them 12 and 24 h after treatment. Conclusion: Premedication with ibuprofen and indomethacin can effectively control short term post-operative pain; the lower incidence of side effects and greater analgesic power of ibuprofen make it a superior choice.Keywords: Ibuprofen; Indomethacin; Irreversible Pulpitis; Non-Steroidal Anti-Inflammatory Drugs; Post-Endodontic Pai

The Effect of Root Coating with Titanium on Prevention of Root Resorption in Avulsed Teeth; An Animal Study

Introduction: Tooth avulsion is a real dental emergency. If immediate replantation is not performed, the avulsed tooth may be lost due to inflammatory or replacement resorption. This animal study aimed to evaluate the bone response to the titanium coating of the root surface as an artificial barrier, and prevention of resorption of avulsed teeth. Methods and Materials: This experimental study was conducted on four male dogs. The dogs were randomly divided into two groups for assessment at two and eight weeks. Four teeth were extracted in each animal. The root surfaces of the test group were coated with a titanium layer using the Electron Beam Deposition system. After 24 h, replantation of the teeth was performed. Two animals were sacrificed after two weeks and the remaining dogs were killed after eight weeks. The presence of inflammation, inflammatory resorption, replacement resorption, periodontal regeneration, periapical granuloma and ankylosis were evaluated through histological analyses. Results: Inflammatory root resorption was not present in any tooth except one tooth in the coated group after eight weeks. Replacement resorption was noted just in three of the non-coated teeth after two weeks and two teeth after eight weeks. The McNemar's test revealed that the frequency of replacement resorption in the non-coated group was significantly higher than the coated group (P=0.031). Conclusion: Based on the results of this study, it seems that coating the root surfaces of avulsed teeth with titanium may control the replacement root resorption.Keywords: Avulsion; Root Resorption; Titanium Coatin

Effect of hydroalcoholic extract of Berberis integerrima and resveratrol on ovarian morphology and biochemical parameters in Letrozole-induced polycystic ovary syndrome rat model: An experimental study

Background: Resveratrol and Berberis integerrima (B. integerrima) are known to be natural antioxidants and regulators of human metabolism. However, the effects of resveratrol and B. integerrima on the ovarian morphology in polycystic ovary syndrome (PCOS) are not obvious. Objective: This study aimed to determine the effect of the hydroalcoholic extract of B. integerrima in combination with resveratrol on some biochemical parameters and ovarian morphology in the letrozole-induced PCOS rat. Materials and Methods: Seventy adult female Sprague-Dawley rats aged 10-12 weeks weighing 200 ± 20 gr were randomly divided into seven groups (n = 10/each). Group I): normal; Group II): vehicle; Group III): letrozole-induced PCOS 1 mg/kg letrozole orally, rats receiving 1 cc normal saline orally; Group IV): PCOS + receiving 150 mg/kg metformin orally; Group V): PCOS + receiving 20 mg/kg resveratrol orally; Group VI): PCOS + 3 gr/kg barberry orally; and Group VII): PCOS + receiving 3 gr/kg barberry and 20 mg/kg resveratrol orally. All animals were followed-up for 63 days. The biochemical parameters and histological assessments of ovaries were performed. Results: Resveratrol alone and/or in combination with B. integerrima treatment in rats led to a significant decrease in low-density lipoprotein, triglyceride, malondialdehyde , and tumor necrosis factor-alpha concentrations (p = 0.02). The groups IV, V, VI, and VII showed a decrease in insulin resistance and an increase in the superoxide dismutase, total antioxidant capacity, and high-density lipoprotein (p = 0.01). No significant difference was observed between the level of serum glucose in the treatment groups. Number of cystic follicles had a significant decrease in barberry, resveratrol, and their combination groups (p &lt; 0.001). Conclusion: Resveratrol, B. integerrima, and their combination as natural products with fewer side effects might be effective as an alternative medicine in treatment of PCOS. Key words: Barberry, Resveratrol, Polycystic ovary syndrome, Ovary, Rat

Comparative antibacterial effects of ginger and marjoram extract versus conventional irrigants on mature Enterococcus faecalis biofilms : an in vitro study

This study evaluated antibacterial effects of Ginger and Marjoram extract compared with Routine Intracanal Irrigants on Mature Enterococcus faecalis Biofilms. Sixty-six extracted human teeth, were randomly assigned to four groups 5.25% sodium hypochlori