51 research outputs found

    The culm and glume anatomical study on Lolium (Poaceae) species in Iran

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    Lolium (Poaceae) is composed of five species in Iran that are of forage and weed importance. Culm and glume anatomy of grasses is inadequately explored. In the present study culm and glume anatomical structures of 17 population of four Lolium species is considered by use of 16 qualitative and quantitative features to distinguish Lolium species in Iran and to determine their diagnostic value. The culm cross-section showed multilayered hypodermis, ribbed or un-ribbed culm cross-sections, cuticles with different thicknesses, and the cortex with different tissues. Vascular bundles are arranged in two to more rings in the culm anatomy. Glume anatomical observations showed differences in girder attachment to vascular bundles, the outline of the cross-section, and the cortex tissue composition. The multi-variate statistical method based on culm and glume anatomical features showed that L. perenne and L. multiflorum are grouped near each other but there is more mixture between L. persicum and L. rigidum. Our findings are in agreement with the grouping pattern achieved by previous researches on leaf anatomy and lemma and palea micro-morphology of the same species. The molecular study by ISSR also provides support for the present study. The culm and glume anatomy of species studied provides valuable data for taxonomic purposes

    Mortality rate and predicting factors of traumatic thoracolumbar spinal cord injury: a systematic review and meta-analysis

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    Objective: To estimate the summation of mortality rate and the contributing factors in patients with traumatic thoracolumbar spinal cord injuries (TLSCI). Methods: A systematic search of observational studies that evaluated the mortality associated with TLSCI in MEDLINE and EMBASE was conducted. The study quality was evaluated using a modified quality assessment tool previously designed for observational studies. Results: Twenty-four observational studies involving 11,205 patients were included, published between January 1, 1997, and February 6, 2016. Ten studies were of high quality, thirteen were of moderate quality, and one study was of low quality. Seventeen reports described risk factors for mortality and eleven of these studies used a multiple regression models to adjust for confounders. The reported mortality rate ranged from 0 to 37.7% overall and between 0 and 10.4% in-hospital. The sum of mortality for in-hospital, 6-month, and 12-month were 5.2%, 26.12%, 4.3%, respectively. The mortality at 7.7 years follow-up was 10.07% and for 14 years follow-up reports ranged from 13.47% to 21.46%. Associated data such as age at injury, male to female ratio, pre-existing comorbidities, concomitant injuries, duration of follow-up, and cause of death have been underreported in studies investigating the mortality rate after TLSCI. Conclusion: Currently no study has accurately assessed mortality in the thoracolumbar spine, while there is general agreement that traumatic thoracolumbar spinal cord injuries are important

    Platinum Nanoparticles in Biomedicine: Preparation, Anti-Cancer Activity, and Drug Delivery Vehicles

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    Cancer is the main cause of morbidity and mortality worldwide, excluding infectious disease. Because of their lack of specificity in chemotherapy agents are used for cancer treatment, these agents have severe systemic side effects, and gradually lose their therapeutic effects because most cancers become multidrug resistant. Platinum nanoparticles (PtNPs) are relatively new agents that are being tested in cancer therapy. This review covers the various methods for the preparation and physicochemical characterization of PtNPs. PtNPs have been shown to possess some intrinsic anticancer activity, probably due to their antioxidant action, which slows tumor growth. Targeting ligands can be attached to functionalized metal PtNPs to improve their tumor targeting ability. PtNPs-based therapeutic systems can enable the controlled release of drugs, to improve the efficiency and reduce the side effects of cancer therapy. Pt-based materials play a key role in clinical research. Thus, the diagnostic and medical industries are exploring the possibility of using PtNPs as a next-generation anticancer therapeutic agent. Although, biologically prepared nanomaterials exhibit high efficacy with low concentrations, several factors still need to be considered for clinical use of PtNPs such as the source of raw materials, stability, solubility, the method of production, biodistribution, accumulation, controlled release, cell-specific targeting, and toxicological issues to human beings. The development of PtNPs as an anticancer agent is one of the most valuable approaches for cancer treatment. The future of PtNPs in biomedical applications holds great promise, especially in the area of disease diagnosis, early detection, cellular and deep tissue imaging, drug/gene delivery, as well as multifunctional therapeutics

    Prevalence of reflux nephropathy in Iranian children with solitary kidney: results of a multi-center study

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    Abstract Background: Given the importance of the function of the remnant kidney in children with unilateral renal agen‑ esis and the significance of timely diagnosis and treatment of reflux nephropathy to prevent further damage to the remaining kidney, we aimed to determine the prevalence of reflux nephropathy in this subgroup of pediatric patients. Methods: In general, 274 children referred to pediatric nephrologists in different parts of Iran were evaluated, of whom 199 had solitary kidney and were included in this cross‑sectional study. The reasons for referral included urinary tract infection (UTI), abnormal renal ultrasonography, being symptomatic, and incidental screening. Demographic characteristics, including age and gender were recorded. History of UTI and presence of vesicoureteral reflux (VUR) were evaluated. Results: Of the 274 children evaluated in this study with the mean age (SD) of 4.71 (4.24) years, 199 (72.6%) had solitary kidney. Among these, 118 (59.3%) were male and 81 (60.7%) were female, 21.1% had a history of UTI, and VUR was present in 23.1%. The most common cause of referral was abnormal renal ultrasonography (40.2%), followed by incidental screening (21.1%), being symptomatic (14.1%), and UTI (5.5%). In 116 children (58.3%), the right kidneys and in 83 (41.7%) the left kidneys were absent. Besides, 14.6% of the participants had consanguineous parents and 3% had a family history of solitary kidney. Upon DMSA scan, the single kidney was scarred in 13.1%, of which only 7.5% were associated with VUR. In addition, proteinuria and hematuria were observed in 6.5% and 1.5% of children, respectively. Conclusions: The prevalence of reflux nephropathy was 7.5% in children with solitary kidney with a male predomi‑ nance. Given the relatively high prevalence of reflux nephropathy in these children, screening for VUR in the remnant kidney appears to be essential in this population. Keywords: Vesicoureteral reflux, Nephropathy, Children, Solitary kidney, Renal agenesi

    TSH and FT4 reference interval recommendations and prevalence of gestational thyroid dysfunction: quantification of current diagnostic approaches

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    Context Guidelines recommend use of population- and trimester-specific TSH and FT4 reference intervals (RIs) in pregnancy. Since these are often unavailable, clinicians frequently rely on alternative diagnostic strategies. We sought to quantify the diagnostic consequences of current recommendations. Methods We included cohorts participating in the Consortium on Thyroid and Pregnancy. Different approaches were used to define RIs: a TSH fixed upper limit of 4.0 mU/L (fixed limit approach), a fixed subtraction from the upper limit for TSH of 0.5 mU/L (subtraction approach) and using non-pregnancy RIs. Outcome measures were sensitivity and false discovery rate (FDR) of women for whom levothyroxine treatment was indicated and those for whom treatment would be considered according to international guidelines. Results The study population comprised 52,496 participants from 18 cohorts. Compared to the use of trimester-specific reference intervals, alternative approaches had a low sensitivity (0.63-0.82) and high FDR (0.11-0.35) to detect women with a treatment indication or consideration. Sensitivity and FDR to detect a treatment indication in the first trimester were similar between the fixed limit, subtraction and non-pregnancy approach (0.77-0.11 vs 0.74-0.16 vs 0.60-0.11). The diagnostic performance to detect overt hypothyroidism, isolated hypothyroxinemia and (sub)clinical hyperthyroidism mainly varied between FT4 RI approaches, while the diagnostic performance to detect subclinical hypothyroidism varied between the applied TSH RI approaches. Conclusion Alternative approaches to define RIs for TSH and FT4 in pregnancy result in considerable over- and underdiagnosis compared with population- and trimester-specific RIs. Additional strategies need to be explored to optimize identification of thyroid dysfunction during pregnancy

    Managing academic libraries: principles and practice

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    The impact of portfolio-based writing instruction on writing performance and anxiety of EFL students

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    Although the usefulness of alternative assessment in second language (L2) classrooms has been extensively recognized by scholars, the use of the various types of alternative assessment in English as a Foreign Language (EFL) contexts has not received adequate attention by L2 practitioners. To contribute to this line of research, the present research sought to examine the impact of a portfolio-based writing instruction on writing performance and writing anxiety of EFL students. To this end, a number of 41 EFL learners were recruited as the participants of this study. They were then randomly divided to an experimental group (N=21) and a control group (N=20). The participants in the experimental group received portfolio-based writing instruction, whereas the control group received the regular writing instruction with no archiving of students’ drafts in portfolios. Timed-writing tasks and the Second Language Writing Anxiety Inventory (SLWAI) were employed to collect the data. The results obtained from ANCOVA analysis revealed that the portfolio-based writing instruction aided the participants in improving their writing performance more than the control group. Moreover, it was found that the use of portfolios significantly reduced the L2 writing anxiety of the participants while the traditional writing instruction did not have any significant impact on L2 writing anxiety of the control group. The pedagogical implications for portfolio-based writing instruction are discussed finally

    A Cross Analysis of Impact University Ranking System

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    First edition of University Impact Ranking (UIR) has been published, and although it’s still in a process of rapid evolution, the result is likely to substantially influence the long-term development of higher education systems across the world based on the United Nations’ Sustainable Development Goals (SDGs). This study aims to analyze and critique the principal ranking system prepared by Times Higher Education which assess universities against the SDGs. This study investigated the reliability of Times Higher Education University Impact Ranking (UIR) and attempted to identify its contribution and impact of participating universities on their societies. Taking an explanatory case study approach, this study used observation, document study, and experts’ reflection as data collection methods. The findings suggest that UIR does not contribute sufficiently to identification of universities that have a good impact on their societies to achieve SDGs
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