526 research outputs found
An ELT textbook evaluation: A two-phase criterion
It is by now well established that materials may have an impact beyond simply learning a language they present. Thus, we need to survey thoroughly the materials to find out the influence they might have on learners' progress and attitude. Hence, in this study attempts have been made to investigate the cons and pros of a textbook (Summit 2B) which is currently being widely used in Iranian EFL classes. The textbook has been evaluated based on a model provided by McDonough and Shaw (1993) on the basis of two stages: an external evaluation that offered a brief overview of the textbook from the outside and a closer and more detailed internal evaluation. Efforts have been made to critically evaluate the textbook in terms of the layout, design, content, language type, different activities, tasks, as well as the skills emphasized in the book. The findings showed that albeit there appears to be some shortcomings, this book (Summit 2B) seems to be more efficient to meet the requirements of the Iranian EFL learners as compared with the older textbooks which have hitherto been used at different language classes. Accordingly, investigating and evaluating the book proved to be very lucrative and valuable in terms of pedagogy as well as the efficient attributes that suits the context of the present study. Finally, the implications as regards the efficiency of this particular course-book as the consequence of evaluating it have been put forward and the strengths and weaknesses related to it have been argued
Synthesis and Characterization of Simvastatin-N-succinyl chitosan-citicoline Conjugated Form Intended for Improving Alzheimer’s Disease in Long Term Use of Simvastatin
Introduction: Simvastatin is a semisynthesis statin. Statins inhibit 3-hydroxy-3-methylglutaryl coenzyme A reductase, a key enzyme of cholesterol synthesis, in AMPK (AMP-activated protein kinase) signaling pathway. Simvastatin is able to cross blood brain barrier more than the other statins, due to its lipophilic nature. There is controversy about the effect of simvastatin on Alzheimer’s disease (AD). For example, simvastatin can induce AD through insulin signaling pathway but can ameliorate AD via MAPK (Mitogen-Activated Protein Kinase) signaling pathway. In this study, we report the synthesis of a conjugated form of simvastatin with citicoline, to block negative effect of simvastatin on insulin signaling pathway and increase positive effect of simvastatin on MAPK signaling pathway and chitosan as a linker between these two drugs.
Methods and Results: for simvastatin-n-succinyl chitosan-citicoline synthesis, chitosan reacted with succinic acid to form n-succinyl chitosan. Then simvastatin connected to n-succinyl chitosan via acetylation reaction. After 24 hours citicoline was added to reaction media. H-NMR and FT-IR were done to examine whether the conjugation reaction has been done or not. Characterization and morphology tests have been done on reaction result.
H-NMRresults approved the synthesis of drug-polymer. FT-IR results showed both amide and ester peaks. Maximum absorptions (λmax) of all primary chemicals were seen in UV visible spectroscopy results of conjugated form.SEM result showed that the conjugated form has nanoparticulate structure in size range of 100-300 nanometers. X-RD result showed a peak under 25 theta. Another characterization test wasRBC hemolysis with six different concentrations, in which normal saline was negative control and Triton was positive control.
Conclusions: Conjugation of lipophilic simvastatin with hydrophilic citicoline to improve AD can be done with helping of a polymer which is rich in carboxylic acid
Neutron dose evaluation of Elekta Linac at two energies (10 & 18 MV) by MCNP code and comparison with experimental measurements
Medical linear accelerators, besides the clinically high energy electron and photon beams, produce other secondary particles such as neutrons which escalate the delivered dose. In this study the neutron dose at 10 and 18MV Elekta linac was obtained by using TLD600 and TLD700 as well as Monte Carlo simulation. For neutron dose assessment in 2020 cm2 field, TLDs were calibrated at first. Gamma calibration was performed with 10 and 18 MV linac and neutron calibration was done with 241Am-Be neutron source. For simulation, MCNPX code was used then calculated neutron dose equivalent was compared with measurement data. Neutron dose equivalent at 18 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 3.3, 4, 5 and 6 cm. Neutron dose at depths of less than 3.3cm was zero and maximized at the depth of 4 cm (44.39 mSvGy-1), whereas calculation resulted in the maximum of 2.32 mSvGy-1 at the same depth. Neutron dose at 10 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 2.5, 3.3, 4 and 5 cm. No photoneutron dose was observed at depths of less than 3.3cm and the maximum was at 4cm equal to 5.44mSvGy-1, however, the calculated data showed the maximum of 0.077mSvGy-1 at the same depth. The comparison between measured photo neutron dose and calculated data along the beam axis in different depths, shows that the measurement data were much more than the calculated data, so it seems that TLD600 and TLD700 pairs are not suitable dosimeters for neutron dosimetry in linac central axis due to high photon flux, whereas MCNPX Monte Carlo techniques still remain a valuable tool for photonuclear dose studies
Statin therapy and cardiovascular protection in type 2 diabetes:The role of baseline LDL-Cholesterol levels. A systematic review and meta-analysis of observational studies
Aim: The guidelines recommend statins to prevent cardiovascular events in patients with type 2 diabetes (T2D) however, the importance of baseline LDL-Cholesterol (LDL-C) levels remains controversial. This study aimed to determine the association of statin use in T2D patients with major adverse cardiovascular events (MACE) and all-cause mortality and whether this association differs by baseline LDL-C levels. Data synthesis: Medline, Embase, and Web of Science were systematically searched from inception until January 2022. Observational studies in patients with T2D comparing statin users vs non-users, with reports of the baseline LDL-C levels, were included. Random-effects meta-analysis and meta-regression were performed to estimate the overall effect on the risk of all-cause mortality and MACE (a composite of myocardial infarction, heart failure, stroke, and revascularization events) and the modification in the association by baseline LDL-C levels. We categorized studies according to their baseline LDL-C levels into 1) <100 mg/dl (2.59 mmol/l), 2) 100–130 mg/dl (2.59–3.37 mmol/l) and 3) >130 mg/dl (3.37 mmol/l) categories. A total of 9 cohort studies (n = 403,411 individuals) fulfilled our criteria. The follow-up duration ranged from 1.7 to 8 years. The overall combined estimate showed that statin therapy was associated with a significantly lower risk of MACE (Hazard Ratio (HR): 0.70 [95% CI 0.59 to 0.83], Absolute risk reduction percentage (ARR%): 3.19% [95%CI 0.88 to 5.50%) and all-cause mortality (HR: 0.60 [95% CI 0.46 to 0.79], ARR%: 5.23% [95% CI 2.18 to 8.28%), but varied, albeit not statistically significant, by baseline LDL-C levels. Studies with baseline LDL-C levels higher than 130 mg/dl had the greatest reduction of MACE (HR: 0.58 [95% CI 0.37 to 0.90]) and all-cause mortality risk (HR: 0.51 [95% CI [ 0.29 to 0.90]). The HRs of MACE in studies with LDL-C levels of 100–130 mg/dl and <100 mg/dl categories were respectively (0.70 [95% CI 0.59 to 0.83]) and (0.83 [95% CI [0.68 to 1.00]); and that of all-cause mortality were respectively (0.62 [95% CI 0.38 to 1.01]) and (0.67 [95% CI [0.44 to 1.02]). Statin use changes the HRs of MACE (0.99 [95%CI, 0.98 to 0.99]; P = 0.04) and all-cause mortality (0.99 [95% CI 0.98 to 1.01]; P = 0.8) per each mg/dl increase in baseline LDL-C level in meta-regression analyses. Conclusion: Statin therapy in patients with T2D was associated with reduced risk of MACE and all-cause mortality. Significant differences across studies with different baseline LDL-C levels were not observed.</p
Development and Psychometric Evaluation of the Motivation for Healing Scale in Patients with Cancer
Introduction: This study was conducted to develop and validate a Motivation for Healing Scale (MHS) in Cancer. Methods: in this methodological study, the MHS draft was developed based on the approach of Waltz and colleagues using existing scales and concept analysis. The psychometric features, including face validity (qualitative and quantitative), content validity (qualitative and quantitative), structural validity (exploratory and confirmatory factors), and construct validity (convergent and discriminant validity) were assessed. Finally, the reliability was evaluated using internal consistency, and stability. Results: Based on the results of the qualitative phase, an initial item pool was generated with 55 items, Exploratory and confirmatory factor analyses were performed on the data collected from 404 patients. 25 Items were excluded during the psychometric evaluation phases. Reliability assessment and internal consistency assessment revealed that Cronbach’s alpha value of the 25-item MHS was 0.912. The results of intraclass correlation coefficient (0.93, 95% CI: 0.86– 0.96) showed the stability was strong. Conclution: The 25-item MHS is a valid and reliable scale for the assessment of motivation for healing in patients with cancer
Application of the Kirkpatrick Model in Evaluation of the Educational Prevention Program of Self-Medication in Women
Background & Objective: Self-medication is one of the chief health problems and educational
programs on its prevention are very important. An educational program can be considered
effective, if it can make the necessary changes in participants’ knowledge and behavior. The aim
of this study was to evaluate the educational prevention program of self-medication in women
using the Kirkpatrick model.
Methods: This evaluation study was carried out on 88 women. The cluster sampling method was
used. The data collection tools consisted of the Dundee Ready Educational Environment Measure
(DREEM) and a researcher-made questionnaire based on the Kirkpatrick model, the validity and
reliability of which were measured. The experimental group attended the educational program for
1 month. The effectiveness rate of the course was calculated based on significant differences in
learning, reaction, and behavior scores of the case and control groups during the pre-test and posttest.
The collected data were analyzed in SPSS statistical software using descriptive and analytical
statistical tests.
Results: The mean scores of desirability rate of participants’ reactions in terms of students’
perception of learning environment, students’ academic self-perception, students’ social selfperception,
students’ perception of atmosphere, and students’ perception of teachers were 44.81 ±
7.06, 31.50 ± 4.11, 22.50 ± 3.54, 43.10 ± 7.46, and 41.37 ± 5.20, respectively. After the
educational intervention, t-test results showed a significant difference between the experimental
and control groups in mean score of knowledge change and attitude change in the second
evaluation level, and also between mean score of behavior change in the third level (P < 0.001).
Conclusion: According to the Kirkpatrick model, the educational prevention program of selfmedication
resulted in favorable outcomes in the three evaluated levels of reaction, learning, and
behavior, and showed satisfactory efficiency.
Key Words: Kirkpatrick model, Evaluation, Self-medication, Educatio
Cytotoxic Alkaloids Derived from Marine Sponges: A Comprehensive Review
Marine sponges (porifera) have proved to be a prolific source of unique bioactive secondary metabolites, among which the alkaloids occupy a special place in terms of unprecedented structures and outstanding biological activities. Identification of active cytotoxic alkaloids extracted from marine animals, particularly sponges, is an important strive, due to lack of knowledge on traditional experiential and ethnopharmacology investigations. In this report, a comprehensive survey of demospongian bioactive alkaloids in the range 1987-2020 had been performed with a special emphasis on the potent cytotoxic activity. Different resources and databases had been investigated, including Scifinder (database for the chemical literature) CAS (Chemical Abstract Service) search, web of science, Marin Lit (marine natural products research) database. More than 230 representatives of different classes of alkaloids had been reviewed and classified, different genera belonging to the phylum porifera had been shown to be a prolific source of alkaloidal molecules, including Agelas sp., Suberea sp., Mycale sp., Haliclona sp., Epipolasis sp., Monanchora sp., Crambe sp., Reniera sp., and Xestospongia sp., among others. The sufficient production of alkaloids derived from sponges is a prosperous approach that requires more attention in future studies to consider the constraints regarding the supply of drugs, attained from marine organisms
Inhibition of Akt phosphorylation attenuates resistance to TNF-α cytotoxic effects in MCF-7 cells, but not in their doxorubicin resistant derivatives
Objective(s): Acquisition of TNF-α resistance plays role in the onset and growth of malignant tumors. Previous studies have demonstrated that MCF-7 cell line and its doxorubicin resistant variant MCF-7/Adr are resistant against the cytotoxic effects of TNF-α. In this study, we investigated the role of Akt activation in resistance of MCF-7 and MCF-7/Adr against TNF-α cytotoxicity. Materials and Methods: The role of Akt activation in TNF-α cytotoxicity was investigated by MTT cell viability assay following treatment of the cells with the chemical inhibitor of Akt activation with or without TNF-α treatment. Phosphorylation of Akt at Ser473 before and after 72 hr TNF-α treatment  was also determined by western blot. Results: TNF-α treatment led to enhancement of Akt Ser473 phosphorylation. Treatment of MCF-7 cells with TNF-α along with Akt-inhibitor agent, tricribine, attenuated Akt Ser473 phosphorylation and sensitized these cells to the cytotoxic effects of TNF-α in a dose and time dependent manner while tricribine treatment did not cause any significant cytotoxicity in MCF-7/Adr cells alone or in combination with TNF-α. Conclusion: These results demonstrate that Akt phosphorylation plays pivotal role in the resistance of MCF-7 cells against TNF-α-induced cytotoxicity while it might play no significant role in the resistance of MCF-7/Adr cells against TNF-α
Statin therapy and cardiovascular protection in type 2 diabetes: The role of baseline LDL-Cholesterol levels. A systematic review and meta-analysis of observational studies
Aim: The guidelines recommend statins to prevent cardiovascular events in patients with type 2 diabetes (T2D) however, the importance of baseline LDL-Cholesterol (LDL-C) levels remains controversial. This study aimed to determine the association of statin use in T2D patients with major adverse cardiovascular events (MACE) and all-cause mortality and whether this association differs by baseline LDL-C levels. Data synthesis: Medline, Embase, and Web of Science were systematically searched from inception until January 2022. Observational studies in patients with T2D comparing statin users vs non-users, with reports of the baseline LDL-C levels, were included. Random-effects meta-analysis and meta-regression were performed to estimate the overall effect on the risk of all-cause mortality and MACE (a composite of myocardial infarction, heart failure, stroke, and revascularization events) and the modification in the association by baseline LDL-C levels. We categorized studies according to their baseline LDL-C levels into 1) 130 mg/dl (3.37 mmol/l) categories. A total of 9 cohort studies (n = 403,411 individuals) fulfilled our criteria. The follow-up duration ranged from 1.7 to 8 years. The overall combined estimate showed that statin therapy was associated with a significantly lower risk of MACE (Hazard Ratio (HR): 0.70 [95% CI 0.59 to 0.83], Absolute risk reduction percentage (ARR%): 3.19% [95%CI 0.88 to 5.50%) and all-cause mortality (HR: 0.60 [95% CI 0.46 to 0.79], ARR%: 5.23% [95% CI 2.18 to 8.28%), but varied, albeit not statistically significant, by baseline LDL-C levels. Studies with baseline LDL-C levels higher than 130 mg/dl had the greatest reduction of MACE (HR: 0.58 [95% CI 0.37 to 0.90]) and all-cause mortality risk (HR: 0.51 [95% CI [ 0.29 to 0.90]). The HRs of MACE in studies with LDL-C levels of 100–130 mg/dl and <100 mg/dl categories were respectively (0.70 [95% CI 0.59 to 0.83]) and (0.83 [95% CI [0.68 to 1.00]); and that of all-cause mortality were respectively (0.62 [95% CI 0.38 to 1.01]) and (0.67 [95% CI [0.44 to 1.02]). Statin use changes the HRs of MACE (0.99 [95%CI, 0.98 to 0.99]; P = 0.04) and all-cause mortality (0.99 [95% CI 0.98 to 1.01]; P = 0.8) per each mg/dl increase in baseline LDL-C level in meta-regression analyses. Conclusion: Statin therapy in patients with T2D was associated with reduced risk of MACE and all-cause mortality. Significant differences across studies with different baseline LDL-C levels were not observed
Epidemiology of substance and opium use among adult residents of Tehran; a comprehensive report from Tehran cohort study (TeCS)
Background: The prevalence and burden of substance and opium use have increased worldwide over the past decades. In light of rapid population changes in Tehran, we aimed to evaluate the prevalence of opium and other substance use among adult residents in Tehran, Iran. Method: From March 2016 to March 2019, we utilized data from 8 296 participants in the Tehran Cohort Study recruitment phase (TeCS). We calculated the age-sex-weighted prevalence of substance use and the geographic distribution of substance use in Tehran. We also used logistic regression analysis to determine possible determinants of opium use. Result: We analyzed data from 8 259 eligible participants with complete substance use data and the average age of participants was 53.7 ± 12.75 years. The prevalence of substance use was 5.6% (95% confidence interval [CI]: 4.6- 7.1%). Substance use was more common in males than females (Prevalence: 10.5% [95% CI: 8.6- 12.6%] vs. 0.5% [95% CI: 0.2- 1.2%], respectively). The age-sex weighted prevalence of substance use was 5.4% (95% CI: 4.6-7.1%). Moreover, opium was the most frequently used substance by 95.8% of substance users. Additionally, we found that male gender (Odds ratio [OR]: 12.1, P < 0.001), alcohol intake (OR: 1.3, P = 0.016), and smoking (OR: 8.5, P < 0.001) were independently associated with opium use. Conclusions: We found that the prevalence of substance use in Tehran was 5.6%, and opium was the most frequently used substance. In addition, male gender, lower levels of education, alcohol, and tobacco consumption are the main risk factors for substance use in Tehran. Healthcare providers and policymakers can utilize our results to implement preventive strategies to minimize substance use in Tehran
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