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This study was designed to investigate the impact of visual mnemonic technique on young and adult Iranian English learners' vocabulary learning. The current study followed a quasi-experimental design. 48 female students were selected based on their performance on the Quick Placement Test. The participants were divided into four groups, two experimental and two control groups. Prior to the treatment, the participants of both groups were given a pre-test to determine the knowledge of vocabulary. Then, the experimental groups received the visual mnemonic technique for 8 sessions. The control groups went through a traditional method of teaching vocabulary. After 8 sessions, a post-test was administered to all groups. Two-way ANOVA between groups was run to the results of the vocabulary tests. The results exhibited that the experimental groups who received instruction on mnemonic technique outperformed their counterparts in post-test of vocabulary. However, the differences between the effects of mnemonic technique for young and adult learners who received the specific treatment were not statistically significant (P=0.05).

The present study intended to investigate the possible effects of speech acts strategies on Iranian beginner and intermediate EFL learners' speaking ability. The first step in conducting this research was the administration of QPT [Quick Placement Test] as the homogenizing tool. It was administered to 180 beginners and intermediate EFL learners. After analyzing the results, 80 males and females as starters and 80 males and females as intermediate subjects were chosen. Then, the beginner and intermediate EFL learners were randomly divided into control and experimental groups (including 40 beginner male and 40 female EFL learners in each class). Next, a pretest of speaking was administered to all the participants and the experimental groups received speech act role play as treatment. However, the researcher did not use any treatment of speech acts in control groups. After ten sessions, the posttest was administered to all participants. The findings suggested that awareness raising on speech acts resulted in a better speaking ability as compared to the simply traditional teaching of speaking for Iranian intermediate and beginner EFL learners. Additionally, intermediate EFL learners' achievement in speaking was not in line with the beginner EFL learners' achievement in the corresponding group. Finally, it was found that gender does not interact with awareness raising on speech acts in such a way as to produce a statistically significant effect on the beginner and intermediate EFL learners' speaking ability.

The present investigation was an attempt to study the effect of using compensation and determination strategies on Iranian upper-intermediate EFL learners' vocabulary development. The question which the present study was trying to answer was: Do compensation and determination strategies have any statistically significant effects on Iranian upper- intermediate EFL learners' vocabulary development? To that end, QPT was administered to 110 female EFL learners learning English language at Shokouh Institute in Rasht, Iran. So 90 learners were selected for this study and they were divided into two experimental groups and one control group, each group contained 30 learners. Prior to the treatment, the participants were given a pretest to assess their initial knowledge of English vocabulary. The experimental groups received treatment. The researcher used compensation and determination strategies in ten sessions. However, in the control group, the new words were taught in traditional way. After ten sessions, a posttest was administered to all groups. One-way ANOVA was conducted to see if the treatment was effective or not. The results were computed and analyzed through SPSS and it was found that using compensation and determination strategies had a positive effect on the participants' vocabulary development.

This study was an attempt to investigate Iranian EFL learners' private speech across proficiency levels and gender while doing reading comprehension tasks. Moreover, it was an attempt to examine the different forms of private speech produced by Iranian English learners. Six forms of private speech were coded and analyzed: affective markers, sub-vocalization, switch from L2 to L1, repetition, unfinished sentences, and self-directed questions. It was a descriptive correlational research. The participants of this study were ninety female and male EFL learners at three levels of foreign language proficiency from two schools in Lahijan, Iran. They were selected from 110 students by administering an Oxford Quick Placement Test. Next, reading comprehension tests were administered to the participants. In order to gather data, each participant was equipped with a MP3 voice recorder to keep track of very low private speech markers while performing reading tasks. Pearson Chi-Square test was utilized to determine the probable relationship between the six forms of private speech and learners' proficiency levels and gender. The results revealed that there was statistically significant relationship between the forms of private speech produced by Iranian EFL learners and their foreign language proficiency. However, the outcomes did not yield a significant correlation regarding gender and the forms of private speech. It can be concluded that private speech is responsible for both regulating mental ability in complex tasks and facilitating internalization of mental ability. In second /foreign language learning, externalized private speech functions not just as a self-regulatory mechanism aiding problem-solving but as a tool in learning and internalizing the L2.

This study aimed to investigate the dynamic assessment of writing proficiency in Iranian English learners´ writing ability in transcendence tasks based on Vygotskian perspective. The questions which this research intended to answer were: (1) Does dynamic assessment affect Iranian English learners' writing ability? (2) Do the results of dynamic Assessment differ from the results of a non-dynamic assessment? (3) If learners progress, are they able to maintain their improved performance in the transcendence tasks when the assessment context changes? To answer the questions, 60 learners were selected following an Oxford Placement Test, and then randomly divided into two groups, experimental and control. The experimental group received dynamic assessment based instruction while control group received a non-dynamic writing instruction. After eight sessions, both groups were post tested and underwent a static and a dynamic assessment. The results indicated the outperformance of the experimental group over the control one. After two weeks, the experimental group undertook two transcendence tasks in order to trace their growing proficiency in more difficult and to increase innovative tasks. Moreover, upon analyzing the protocols, an inventory of meditational moves was detected as a posterior. As the result, the study suggests the use of dynamic assessment as a development-oriented procedure to diagnose and develop the learners´ emerging abilities.

Designing short antimicrobial peptides (AMPs), which are active against drug‐resistant bacteria, is a promising way to find new therapeutic agents. In this research, a novel short AMP, PL‐101‐WK, was designed based on PL‐101 (a derivative of plicatamide). Here, the substitution of Phe and His with Trp and Lys was considered. The antimicrobial activity and physicochemical properties of PL‐101‐WK were compared with PL‐101 by in silico analysis. The antimicrobial activity in the presence or absence of NaCl concentration, thermal stability, hemolytic activity, and selectivity of the peptides were determined. By substitution of Lys and Trp residues, positive charge, in vitro stability, and hydrophilicity of PL‐101‐WK were raised compared to the template. PL‐101‐WK had the best minimum inhibitory concentration (MIC) value of 64 μg/ml against Staphylococcus aureus strains, which showed at least 16‐fold reduction when compared to the values of PL‐101. The MICs of PL‐101‐WK were retained toward S. aureus strains at physiological salt concentration. While PL‐101‐WK did not display acceptable thermal stability, it had desirable selectivity against bacteria. The maximum hemolytic activity of PL‐101‐WK was 1.65% at 512 μg/ml. Taken together, increasing positive charge and the presence of Trp residues were enhanced the potential of antibacterial activity of PL‐101. [ABSTRACT FROM AUTHOR]

Background: Bisphenol A (BPA), a synthetic endocrine-disrupting chemical, is a reproductive toxicant. Granulosa cells have significant roles in follicle development, and KIT ligand (KITL) and Anti-Müllerian hormone (AMH) are essential biomolecules produced by them during folliculogenesis. Objective: Due to the widespread use of BPA and its potential epigenetic effects, this study examined the impact of BPA on promoter methylation of amh and kitl genes in mouse granulosa cells. Materials and Methods: Preantral follicles were isolated from ovaries of immature mice and cultured for eight days. Then, follicles were treated with 50 and 100 μM of BPA, and 0.01% (v/v) ethanol for 24 and 72 hr. Growth and degeneration of follicles and antrum formation were analyzed. The granulosa cells were isolated mechanically, and their extracted DNA was treated with sodium bisulfite. The promoter regions of the amh and kitl were analyzed with PCR and sequencing. Results: BPA did not change follicle survival and antrum formation significantly (p = 0.41). However, the culture in the presence of 100 μM BPA had an inhibitory effect on growth. Before BPA treatment, the CpG of the kitl and amh promoters were unmethylated and partially methylated, respectively. While the percent of 5mC in the amh promoter reduced at 100 μM of BPA, it did not alter the kitl promoter methylation. Conclusion: BPA at higher concentrations has an inhibitory effect on follicle growth. Moreover, it seems that the epigenetic impact of BPA restricts to the demethylation of CpG sites. [ABSTRACT FROM AUTHOR]

Background: Lamnin has important effects on human immunity system. The current study aimed to assess the role of L-leucine-7-amido-4-methyl coumarin 1 gene polymorphisms on hepatitis B virus (HBV) susceptibility. Materials and Methods: The rs20558, rs20563, rs10911193, rs10911251, and rs1413390 polymorphisms were analyzed using polymerase chain reaction (PCR) and PCR-reaction--restriction fragment-length polymorphism and amplification-refractory mutation system-PCR using three different groups including chronic HBV-infected patients, HBV patients who were resolved their infection spontaneously and healthy volunteers. Laminin concentrations were also measured in the blood of these individuals. Results: People with rs20558C, rs20563G, and rs10911193T alleles have an increased risk of HBV infection. Moreover, we found that CGTAT haplotype was more frequent in chronically infected people who could affect the mechanism of disease. Furthermore, there was a significant relationship between laminin concentration and rs20558, rs20563, and rs10911193 genotypes in patients. Conclusion: According to the statistical analysis, rs20558, rs20563, rs10911193 polymorphisms probably, related to the chronic HBV infection. In addition, no association of the rs10911251, rs1413390 single nucleotide polymorphisms with the disease was found. [ABSTRACT FROM AUTHOR]

Abstract: Thermostable lipases have many applications in detergent industries and in organic synthesis. There are many ways to improve thermal stability of enzymes, for example, higher hydrophobicity, greater structural packing, higher content of the charged residues, and lower thermolabile ones. In this study, thermolabile Gln (sensitive to higher temperatures) was substituted with Ala in native ELBn12 and mutated K173A lipases to examine its effect on thermal stability and activity of the lipases. Single (Q177A) and double mutants (K173A/Q177A) were expressed in Escherichia coli pLysS. The Q177A variant increased both activity and thermostability of the lipase, whereas K173A/Q177A had a negative effect on the lipase activity and only had better thermal stability than the native at 50 °C. pH stability of the double mutant between 9.0 and 11 was also lower than the other variants. Stability analysis in the presence of chemicals showed that Q177A mutant had better activity with 50% (v/v) organic solvents. On the other hand, K173A lipase showed increased activity with 1% (w/v) nonionic surfactant, and finally K173A/Q177A had better stability with 10 mM metal ions compared to the native lipase. [ABSTRACT FROM AUTHOR]

ELBn12 is a lipase isolated from Enterobacter sp. Bn12 with potential application in biotechnology. Homology modeling and rational design were applied to improve thermal stability of the lipase. K173A substitution introduced an AXXXA motif on the lipase model and it may have role in dimerization and thermostability of the protein. Site-directed mutagenesis was performed to construct the lipase variant. The mutated lipase was expressed in Escherichia coli pLysS and partially purified. Thermostability of the mutated lipase after 1 h of incubation at 70°C was twice that of wild-type lipase under the same conditions. Catalytic activity of the variant was about 1.5-fold towards tricaprylin at 60°C and pH 8.0; moreover, the lipase variant preserved its stability within the pH range of 7.0-11.0. Substitution of superficial hydrophilic Lys with hydrophobic Ala residue increased stability of the mutated lipase in the presence of nonionic surfactants, but this substitution caused lower stability towards polar solvents. Analysis of circular dichroism spectroscopy showed that the K173A mutation altered the secondary structure of the lipase into a more helical one. In conclusion, results of this study demonstrate the positive role of generation of a stabilizing protein motif through rational protein engineering that improves the enzyme characteristics. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Objective(s) Staphylococcus aureus is a common cause of human infection, and emergence of vancomycin-resistance S. aureus is a great concern for treatment of methicillin-resistant S. aureus,(MRSA) in recent years (MRSA). Here, we report the isolation of high-level VRSA. Materials and Methods S. aureus was isolated from foot ulcer of a diabetic woman in Tehran, Iran. Antibiotic susceptibility was determined according to CLSI guidelines. VanA gene cluster PCR was carried out and PCR amplicon of vanA was sequenced. Results S. aureus had high-level vancomycin-resistant (MIC 512 . ƒÊg/ml). Patient's history revealed that VRSA isolate was acquired through community transmission. Only vanA, vanR and vanS genes were amplified in our isolate. Sequencing revealed that the vanA sequence had high similarity to the vanA sequence of Tn1546. Conclusion Although VRSA infection continues to be rare, isolation of community.acquired VRSA is a significant issue and it needs the efforts of public health authorities. [ABSTRACT FROM AUTHOR]

Objective: Vitrification of the ovarian tissue is one of the techniques recommended for preserving the fertility of women who are dealing with infertility. Despite its benefits, our information about the molecular aspects of ovarian follicles vitrification is somehow ambiguous. Therefore, the aim of this study was to evaluate the expression pattern of DNA repair genes in vitrified preantral follicles. Materials and Methods: In this experimental study, the isolated preantral follicles (n=906) from 14-16 days old mice (n=12) were divided into three groups: fresh, toxic and vitrified which were cultured in vitro for 12 days. Preantral follicles were vitrified using cryotop followed by exposure to equilibration solution for five minutes and vitrification solution (VS) for 30 seconds. In the toxic group, preantral follicles were only placed in equilibration and vitrification media and they were then placed in the warming solutions without exposure to liquid nitrogen. On the second and sixth days of the culture period, real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was carried out to evaluate expression of the selected genes involved in DNA repair, including Msh6 (MutS homolog 6), Mre11 (Meiotic recombination 11), Brca1 (Breast cancer type 1), Rad51 (RAD51 recombinase), Pcna (Proliferating cell nuclear antigen) and Atm (ATM serine/threonine kinase). In addition, developmental parameters including growth, survival rate, antrum cavity formation and ovulation were analyzed. Results: The relative mRNA expression of Msh6, Mre11, Brca1, Rad51, Pcna and Atm on the second and sixth days of the culture period in vitrified group was significantly higher than those of the control and toxic groups, but there was no significant difference between the toxic and control groups. In addition, developmental parameters of follicles were similar in both toxic and control groups, while both were significantly higher than that of vitrified group. Conclusion: Vitrification changes the expression pattern of DNA repair genes of the mouse preantral follicles. [ABSTRACT FROM AUTHOR]

Extracting high-yield, high-quality DNA from plant samples is challenging due to the presence of the cell wall, pigments, and some secondary metabolites. The main CTAB method, two of its modified protocols (beta-mercaptoethanol or ammonium acetate were eliminated), the modified Murray and Thompson method, and the Gene All kit were statistically compared based on the quantity and quality of the total DNA (tDNA) extracted from fresh and dried leaves of three medicinal herbs P. harmala , T. ramosissima , and P. reptans . The suitability of the tDNAs for molecular studies was evaluated by polymerase chain reaction (PCR) of the fragments of the internal transcribed spacer (ITS) in nuclear DNA and the trn L-F region in chloroplast DNA. Some significant differences were found between the tDNAs extracted by five extraction methods. With the exception of P. harmala , where the PCR of both the ITS fragments and the trn L-F region worked successfully in all DNA samples, but only the ITS fragments, not the chloroplast trn L-F region, were amplified in the DNA samples of T. ramosissima and P. reptans . The chloroplast trn L-F region was amplified only in DNA samples extracted from fresh and dried leaves of the three studied herbs using the commercial kit. Gene All kit, the main CTAB method, and its modified protocols were the less time-consuming protocols that yielded DNA suitable for downstream PCR vis-a-vis the modified Murray and Thompson method., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.