78 research outputs found
The Rate of Demineralization in the Teeth Prepared by Bur and Er:YAG Laser
Introduction: The present in vitro study evaluated the recurrence rate of caries following cavity preparations with bur (conventional technique) and irradiation by Erbium:Yttrium–Aluminum–Garnet (Er:YAG) laser through micro hardness test.Methods: A total of 72 human extracted molars were randomly divided into 3 groups and class 5 cavities were prepared on them with 3 different methods: G1) conventional bur, G2) Er:YAG laser irradiation alone and G3) laser irradiation + laser treatment. The specimens were immersed in the artificial caries solution with pH of 2.0 and 5.0 (12 days) and then immersed in re-mineralizing solution with pH of 7.0 (25 days). The specimens were longitudinally sectioned and their Vickers micro hardness was determined. Data were statistically analyzed by means of three-way analysis of variance (ANOVA) and Tukey multiple comparisons tests.Results: The micro hardness of the samples was affected by substrate type (enamel and dentin) and low values were achieved in dentin (P < 0.001). Moreover, no significant difference was observed between preparation methods by bar and laser irradiation alone (P ≤ 0.499). Although laser irradiation + laser treatment decreased micro hardness of enamel compared to other methods. In dentin samples, different methods of preparation showed no significant effect on micro hardness (P ≤ 0.874).Conclusion: Due to the similar values of micro hardness following G1 and G2, it seems that Er:YAG laser alone is as much effective as the conventional bur to prevent recurrence caries. However, because of the high prices of laser instruments, bur preparations can be done commonly
Is parent-child interaction therapy effective on aggression and biological indices in pre-school children with parents who use high-potency cannabis? A double-blind randomized controlled trial study in an Iranian sample
BACKGROUND: Improving interpersonal interactions between parents and the child can indirectly reduce the extrapolation behavioral problems, including aggression in children.METHODS: Among parents who used high-potency cannabis (marijuana or ‘gol’ as it is called in Iran) and lived in Tehran, Iran, sixty four caregivers and an Iranian child were selected through respondent-driven sampling and studied in the form of a double-blind randomized controlled trial (RCT) (TCTR20180804001) with repeated measurements method and a 6-month follow-up. The changes in the aggression and cortisol levels were repeatedly evaluated during 12 weeks of interactive treatment and analyzed by Monte Carlo test, repeated measures correlation (rmcorr), and generalized estimating equation (GEE) via SPSS software. Statistical significance was accepted on the level of P < 0.010.RESULTS: 12 weeks of Parent-Child Interaction Therapy (PCIT) had a significant effect on the reduction of aggression and the salivary cortisol level in children (P < 0.010). However, the results did not remain stable till the 6-month follow-up stage (P = 0.067). Also, results revealed a significant relationship between aggression index and the level of cortisol (P < 0.010).CONCLUSION: Since the core of the damage resulted from illicit drug abuse is reflected in interactive activities, improving social interactions can be considered as the key to the treatment of addiction
An empirical investigation on psychological characteristics of entrepreneurs
This paper presents an empirical investigation on psychological characteristics of entrepreneurs in one of Iranian universities located in city of Zanjan, Iran. The proposed study of this paper uses a standard questionnaire in Likert scale and concentrates on three components of locus of control, risk taking and tolerance of ambiguity. The study chooses a sample of 350 out of 11,000 students who were enrolled in various areas and detected that students maintained higher level of risk taking (t-student = 10.999, P-value = 0.000), higher level of locus of control (t-student = 29.708, P-value = 0.000) and lower level of tolerance of ambiguity (t-student = -13.584, P-value = 0.000)
Comparison of the effect of licorice vaginal cream and estrogen vaginal cream on sexual function of postmenopausal women: An RCT
Background: Menopause is a stage in woman’s life that some women experience in middle age and some at a younger age (premature menopause). Low levels of ovarian hormones, during menopause can lead to various complications. Menopause is one of the factors that can affect a woman’s sexual function.
Objective: The present study was conducted to compare the effect of licorice vaginal cream and estrogen vaginal cream on the sexual function of postmenopausal women.
Materials and Methods: In this randomized clinical trial study, 82 postmenopausal women who were referred to health centers in Ilam, Iran from July to November 2020 were randomly divided into 2 groups (n = 41/each). One group was given estrogen vaginal cream 2%, and the other vaginal licorice cream 2%. Participants used the 2 medications for 14-day periods each. We used the finite randomization method. Data collection questionnaires, including a demographic information questionnaire before treatment and a female sexual function index questionnaire were completed before, one month after the medication, and 2 months after using the medication.
Results: The mean score of sexual function in the licorice group was 17.86 ± 4.37 and increased to 20.31 ± 4.63 at the end of the study. The mean score of sexual function in the estrogen group was 17.14 ± 3.99 and increased to 22.97 ± 5.09 at the end of the study (p = 0.015).
Conclusion: The effect of estrogen vaginal cream on the sexual function of postmenopausal women was greater than licorice vaginal cream.
Key words: Vagina, Post menopause, Glycyrrhiza, Estrogens
The Effect of Simulation on Iranian Elementary EFL Learners’ Willingness to Communicate
Little research has so far concentrated on the virtual reality settings for elementary learners using language effectively in real situations. Although previous research has focused on the benefits of using simulation in EFL classrooms by using real objects or visual games by providing these objects, it is costly and difficult for teachers. This study is intended to explore an applicable and effective model of simulated situations for English as a foreign language (EFL) learners and investigate the effects of the simulated environment on the learners’ willingness to communicate (WTC). For this research, 300 elementary-level EFL learners were chosen. A Key English Test (KET) was performed to ascertain homogeneity among the learners. Having done so, the learners were classified into experimental and control groups. A WTC questionnaire created by Macintyre et al. (2001) was employed, after validation through exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and modeling, as an instrument to obtain primary data. The outcomes of Mann-Whitney U test revealed that the simulated environment had positive effects on the participants' WTC. The findings of this study suggest that understanding how a simulated environment affects EFL learners' success in speaking proficiency can help institutes to provide such environments for EFL learners and instructors. This method can be presented at various levels of English proficiency. The focus of this research was mainly on speaking skills; therefore, similar studies can be conducted regarding other language skills, e.g., writing, listening, and reading
Myo-inositol effect on pregnancy outcomes in infertile women undergoing in vitro fertilization/intracytoplasmic sperm injection: A double-blind RCT
Background: Myo-inositol is an intracellular mediator which is involved in various aspects of reproduction in women.
Objective: This study aimed to evaluate the impact of Myo-inositol on the outcomes of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles in infertile women.
Materials and Methods: This double-blind randomized controlled trial was conducted on 70 infertile women referred to the Infertility Treatment Center, Besat hospital, Sanandaj, Iran from May 2019 to September 2019 for IVF/ICSI cycles. The participants were randomly divided into 2 intervention (n = 36) and control (n = 34) groups. The intervention group received 2000 mg of Myo-inositol and 200 mcg folic acid twice a day for 2 months and the control group received 200 mcg of folic acid twice a day for 2 months in the IVF/ICSI cycles (from the third day of cycle until the end of the second month). Finally, the number of oocytes, the quality of embryos, and the IVF/ICSI outcomes were compared between the 2 groups.
Results: The mean numbers of oocytes, MII oocytes, and 2 pronuclear embryos were significantly higher in the intervention group than the control group. Also, the clinical pregnancy and live birth rates in the intervention group were significantly higher than in the controls (p = 0.04).
Conclusion: The administration of Myo-inositol may increase clinical pregnancy and live birth rates by increasing the number of total and meiosis II oocytes in infertile women undergoing IVF/ICSI.
Key words: Infertility, In vitro fertilization, Intracytoplasmic sperm injection, Myoinositol
Antimicrobial Effect of Nano-Calcium Hydroxide on the Four- and Six-Week-Old Intra-Canal Enterococcus Faecalis Biofilm
Statement of the Problem: Enterococcus faecalis (E. faecalis) is one of the most important microorganisms in the evaluation of the antibacterial effects of intra-canal medications due to its ability to penetrate dentinal tubules and form biofilms. Calcium hydroxide, as the most common intra-canal medication, has little effect on this bacterial species. In contrast, it is hypothesized that nano scale hydroxide particles are more effective due to their smaller size and higher surface-to-volume ratio.Purpose: This study aimed to investigate the antimicrobial effect of nano-calcium hydroxide on the four- and six-week-old intra-canal E. faecalis biofilms.Materials and Method: In this in vitro study, seventy maxillary single-canal premolar teeth were used. After cleaning and preparing the root canals, the samples were placed in vials containing E. faecalis solution in which the culture medium was changed daily. Each group was divided into three subgroups (n=20) in terms of the antimicrobial material used as the intra-canal medication including subgroup 1: nano-calcium hydroxide, subgroup 2: calcium hydroxide, and subgroup 3: phosphate-buffered saline solution (control group). The antimicrobial property was measured by counting colony-forming units (CFU). The data were analyzed with Mann-Whitney U and Kruskal–Wallis tests. Statistical significance was set at p< 0.05.Results: The mean CFU in the six-week-old biofilm group was significantly higher than that in the four-week-old biofilm (p= 0.003). A comparison between the subgroups showed a significant decrease in CFU in the six-week-old biofilm in the nano-calcium hydroxide subgroup compared to that in the calcium hydroxide subgroup (p= 0.002). However, the decrease was not significant in the four-week-old biofilm group (p= 0.06).Conclusion: Under the limitations of the present study, the antimicrobial properties of nano-calcium hydroxide were higher than conventional calcium hydroxide on mature biofilm, whereas the antimicrobial properties were not clinically and significantly different on immature biofilm
Highly conductive anion exchange membranes based on polymer networks containing imidazolium functionalised side chains
Two novel types of anion exchange membranes (AEMs) having imidazolium-type functionalised nanofibrous substrates were prepared using the facile and potentially scalable method. The membranes’ precursors were prepared by graft copolymerization of vinylbenzyl chloride (VBC) onto syndiotactic polypropylene (syn-PP) and polyamide-66 (PA-66) nanofibrous networks followed by crosslinking with 1,8-octanediamine, thermal treatment and subsequent functionalisation of imidazolium groups. The obtained membranes displayed an ion exchange capacity (IEC) close to 1.9 mmol g–1 and ionic (OH-) conductivity as high as 130 mS cm–1 at 80 °C. This was coupled with a reasonable alkaline stability representing more than 70% of their original conductivity under accelerated degradation test in 1 M KOH at 80 °C for 360 h. The effect of ionomer binder on the performance of the membrane electrode assembly (MEA) in AEM fuel cell was evaluated with the optimum membrane. The MEA showed a power density of as high as 440 mW cm−2 at a current density is 910 mA cm−2 with diamine crosslinked quaternized polysulfone (DAPSF) binder at 80 °C with 90% humidified H2 and O2 gases. Such performance was 2.3 folds higher than the corresponding MEA performance with quaternary ammonium polysulfone (QAPS) binder at the same operating conditions. Overall, the newly developed membrane was found to possess not only an excellent combination of physico-chemical properties and a reasonable stability but also to have a facile preparation procedure and cheap ingredients making it a promising candidate for application in AEM fuel cell
The Prevalence of Pain and the Role of Analgesic Drugs in Pain Management in Patients with Trauma in Emergency Department
Background: Pain could potentially affect all aspects of patient admission course and outcome in emergency department (ED) when left undertreated. The alleviation of acute pain remains simply affordable but is usually, and sometimes purposefully, left untreated in patients with trauma. This study challenged the conventional emergency department policies in reducing the intensity of acute pain considering the pharmacological treatments.Methods: In this case-control study, the prevalence and intensity of pain in 200 patients were evaluated on admission (T1) and 24 hours later (T2) based on the valid, standardized 10-point numeric rating scale (NRS 0-10) for pain intensity. A group of patients received analgesic drugs and others did not. Changes in pain patterns regarding different aspects of trauma injuries in these two groups were compared.Results: The pain prevalence was high both on admission and 24 hours later. 51.5% of the study population received analgesics and 77.6% of them reported a decrease in the intensity of their pain. Only half of the patients, who did not receive any medication, reported a decrease in their pain intensity after 24 hours. The most beneficial policy to manage the acute pain was a combination therapy of the injury treatment and a supplementary pharmacological intervention.Conclusions: Pharmacological management of pain in patients with trauma is shown to be significantly beneficial for patients as it eases getting along with the pain, and still seems not to affect the diagnostic aspects of the trauma. Pain management protocols or algorithms could potentially minimize the barriers in current pain management of patients with trauma
Isolation and localization of cells expressing Sca-1 in the Adult Mouse Ovary: An evidence for presence of Mesenchymal Stem cells
Objective: Recently growing evident declared that ‘neo-oogenesis’ continues in mature female life span and simultaneously another studies confirmed the presence of spermatogonial stem cells (SSCs). Even though there is agreement between scientist about SSCs population in male gender but on the other side ovarian stem cells have received raising challenges regarding the existence in the surface epithelium of ovary. Mesenchymal stem cells (MSCs) are the most applicable source of stem cells and the common marker of MSCs is Sca-1 so the purpose of this study was to clarify the incidence of stem cells in the surface epithelium of ovary
Methods: forty C57BL6 mice were sacrificed and the ovary carefully excised from its surrounding fat tissue, after mechanical and enzymatic digestion cells were stained with Sca1 to estimate the incidence of positive stem cells (SCs) population fluorescence activated cell sorting (FACS). Part of digested cells used for RT-PCR, also histological section prepared for immunohistochemical (IHC) staining of Sca-1 in ovarian surface epithelium (OSE) FACS.
Results: The gene expression of Sca-1 was confirmed in the ovarian tissue. As well, localization of Sca-1 positive cells was detected in the germinal layer of ovary and epithelial granular layer of primordial follicles. Moreover, we successfully could isolated the Sca-1positive cells through
Conclusion: The present work findings confirmed an inclusive stem cell population in the ovary which can be a strong evident for regeneration of ovarian tissue in either purpose of ovulation scar and neo-oogenesis
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