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Information on the refractive error prevalence in school-aged children will result in delivering the optimal eye health service to this group. Understanding the prevalence of refractive error in school-aged children is crucial to reduce the consequences of uncorrected refractive error. This study aims to investigate the prevalence of refractive error among school-aged children in Shiraz, Iran. In this cross-sectional population-based study, 2001 schoolchildren aged 6–12 years participated. All participants underwent cycloplegic refraction. Spherical equivalent (SE) of −0.50 dioptre or more was considered as myopia, SE of +2.00 dioptre or more as hyperopia, and astigmatism as cylinder power of 0.75 dioptre or more. The difference of 1.00 dioptre or more between two eyes defined as anisometropia. The prevalence of myopia was 11.6% (95% confidence interval [CI]: 10.2–13.1%), hyperopia 6.7% (95%CI: 5.6–7.9%), and astigmatism 28.9% (95%CI: 26.9–31.0%), out of which 82.1% had with the rule astigmatism. Anisometropia was detected in 4.0% (95%CI: 3.2–5.0%) of children. Astigmatism and anisometropia were significantly higher in boys (p < 0.001, p = 0.03 respectively). The SE decreased significantly with increasing age (p < 0.001) indicating an increase in myopia with age. In addition, the rate of myopic astigmatism increased with age (p < 0.001). Among studied schoolchildren 97.0% could achieve the best-corrected visual acuity of 6/6 and 3.0% could not in the better eye. Astigmatism was the most common refractive error among primary school children. The prevalence of myopia was relatively higher than other studies conducted in Iran, and it increased with age. These results may highlight the role of lifestyle changes and increased near work activities on the myopic shift in school-aged children. The findings provide information for screening programmes in school-aged children. [ABSTRACT FROM AUTHOR]

This review summarizes recent developments and advancements in the direct hydrotrifluoromethyl(thiol)ation of alkenes with focused attention on the mechanistic aspects of the reactions. It can be used as a guide for chemists to apply the best hydrotrifluoromethyl(thiol)ation conditions in their work or serve as an inspiration for further research collaborations in the field. [ABSTRACT FROM AUTHOR]

Top-down and bottom-up reading processes have attracted attention from researchers in ESL/EFL teaching/learning. However, the role of these processes and their combination in L2 vocabulary learning and retention still needs further research. Given this, this study sought to consider their role in L2 vocabulary learning and retention by Iranian EFL learners. To this end, 100 intermediate participants were chosen from among a convenience sample of 180 EFL learners. They were then assigned to four random groups (Top-down, Bottom-up, Combined and Control). Finally, target vocabulary learning and retention were assessed by an immediate (learning) and delayed (retention) post-test. ANOVA results revealed that the bottom-up group outperformed the control group. The combined group also did better than the top-down and control groups on the post-test. However, the difference between the top-down and control group did not prove significant. In addition, the combined group surpassed the other groups in terms of the gain in mean scores. As for retention, both the bottom-up and combined processes resulted in the retention of the target vocabulary, with the former being even more effective. It can be suggested that these processes can be regarded as complementary factors in L2 vocabulary learning and retention. [ABSTRACT FROM AUTHOR]

Non-invasive tracking of stem cells after transplant is necessary for cell therapy and tissue engineering field. Herein, we introduce natural and biodegradable nanoparticle to develop a highly efficient nanoprobe with the ability to penetrate the stem cell for tracking. Based on the use of (Gd3+) to label stem cells for magnetic resonance imaging (MRI) we synthesized nanoparticle-containing Gd3+. Gd3+ could be used as t1-weighted MRI contrast agents. In this study, chitosan-alginate nanoparticles were synthesized as a clinical Dotarem® carrier for decreased t1-weighted. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR) were utilized for nanoprobe characterization and ICP analysis was performed for Gd3+ concentration measurement. The results illustrate that nanoprobes with spherical shape and with a size of 80 nm without any aggregation were obtained. Relaxivity results suggest that r1 in the phantom was 12.8 mM−1s−1 per Gd3+ ion, which is 3.5 times larger than that for Dotarem® (r1 ∼3.6 mM−1s−1 per Gd3+ ion) and this result for synthesized nanoprobe in stem cells 3.56 mM−1s−1 per Gd3+ ion with 2.16 times larger than that for Dotarem® was reported and also enhanced signal in in-vivo imaging was observed. Chitosan-alginate nanoparticles as a novel biocompatible probe for stem cell tracking can be utilized in tissue engineering approach. [ABSTRACT FROM AUTHOR]

Many malignant cancers have an increased demand for lipoprotein due to the requirement for lipids for the rapid proliferation of the tumours and which is met by the increased availability of LDL through upregulation of LDL transporters. This unique phenomenon is the basis for the use of LDL based nanoparticles for cell imaging. In this study, a novel MR-active LDL nanoparticle was synthesised as the MRI probes. This MR-active LDL was characterised by using different techniques including scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier-transform infra-red spectroscopy (FTIR) and magnetic resonance imaging (MRI). The intracellular uptake of Gd3+ and cytotoxicity was measured by ICP-AES and MTT assay respectively. Results suggest that this nanoprobe with spherical shape and size of 55 nm has reduced relaxation time compared to commercial contrast agent and is introduced as an appropriate imaging probe. The amount of reabsorption of nanoprobe increased up to 6 h and given that the connection of the chelator does not have an effect on reabsorption proves that entry through transporter of APO section has done. This study lays the basis for exploring a personalised medicine strategy by directing a patient's own LDL to cancer cell imaging in the early stages. [ABSTRACT FROM AUTHOR]

Nowadays, there is growing interest regarding the use of metal Nanoshells as targeted agents of Nano-photo thermal cancer therapy. This study was aimed at synthesis the folic acid (FA)-conjugated with silica @gold core-shell nanoparticles (FA-SiO2@AuNPs) for improving the treatment of melanoma cancer cells. The characterization data showed that the FA-SiO2@AuNPs is spherical in shape and its size is ∼73.7 nm. The intracellular uptake of FA-SiO2@AuNPs into melanoma cells (A375) was measured through the inductively coupled plasma, (∼47.7%). The cytotoxicity of nanoparticles was investigated on A375 and HDF (Human dermal fibroblast) cell lines. Cytotoxicity results indicated that there is no significant cytotoxicity in HDF cell lines treated with nanoparticles. MTT and flow cytometry results showed that the viability of A375 cells treated by SiO2@Au and FA-SiO2@AuNPs was decreased significantly to about 31% and 16% respectively. The higher toxicity of cancer cells was obtained for the cells exposed to 808 nm near-infrared (NIR) laser after incubation with FA-SiO2@AuNPs rather than the non-targeted SiO2@AuNPs. Furthermore, about 64% more cell death was observed for A-375 cells using both photothermal therapy and treatment with FA-SiO2@AuNPs compared to photothermal therapy. Additionally, the majority of the cell deaths were related to the apoptosis process, not necrosis. It can be concluded that FA-SiO2@AuNPs was an effective targeting agent for photothermal therapy in the treatment of melanoma. [ABSTRACT FROM AUTHOR]

Nowadays, gold nanoshells are used in targeted nano photothermal cancer therapy. This study surveyed the application of gold nanoshell (GNs) to thermal ablative therapy for melanoma cancer cells and it takes advantage of the near infrared absorption of gold nanoshells. The synthesis and characterization of glycosylated gold nanoshells (GGNs) were done. The cytotoxicity and photothermal effects of GNs on melanoma cells were evaluated using MTT assay and flow cytometry. The characterization data showed that GGNs are spherical, with a hydrodynamic size of 46.7 nm. Results suggest that the cellular uptake of GGNs was about 78%. Viability assays showed no significant toxicity at low concentrations of GNs. The higher heating rate and toxicity of cancer cells were obtained for the cells exposed to 808 nm NIR laser after incubation with GGNs rather than the GNs. The viability of these cells has dramatically decreased by 29%. Furthermore, 61% more cell lethality was achieved for A375 cells using combined photothermal therapy and treatment with GGNs in comparison to NIR radiation alone. In conclusion, our findings suggest that the synthesized gold/silica core-shell nanoparticles conjugated with glucosamine have high potentials to be considered as an efficient metal-nanoshell in the process of targeted cancer photothermal therapy. [ABSTRACT FROM AUTHOR]

GABACreceptors are ligand-gated chloride channels and have important roles in some neurological functions like vision. Recent investigations demonstrated that these receptors are also expressed in the somatosensory cortex. In this study, we investigated the effect of (1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid (TPMPA) (GABACreceptor antagonist) on the properties of the neuronal response to natural stimuli (whisker deflection) in deep layers of rat barrel cortex. Twenty-eight male Wistar rats, weighing 230–260 g, were used in this study. TPMPA (100 μmol/rat) was administered intracerebroventricularly (ICV). Neuronal responses to deflection of principal (PW) and adjacent (AW) whiskers were recorded in barrel cortex using tungsten microelectrodes. A computer-controlled mechanical displacement was used to deflect whiskers individually or in combination at 30 ms inter-stimulus intervals. ON and OFF responses for PW and AW deflections were measured. A condition-test ratio (CTR) was computed to quantify neuronal responses to whisker interactions. Our data suggest that ICV administration of TPMPA increased neuronal spontaneous activity, ON and OFF responses to PW, and/or AW deflections. However, CTR for neither ON nor OFF responses changed following TPMPA administration. The results of this study demonstrated that inhibition of GABACreceptors by TPMPA can modulate neuronal response properties in rat barrel cortex. [ABSTRACT FROM PUBLISHER]

Background The aim of this study was to evaluate the prevalence of anisometropia in an urban adult population in the north of Iran. Methods This cross-sectional study was conducted among the 40-64-year-old population in Shahroud, Iran. Random cluster sampling was applied to select 6,311 people. Following an interview, optometric and ophthalmologic examinations, including objective non-cycloplegic refractions, were carried out. The prevalence of anisometropia was reported according to non-cycloplegic refraction and with cut-off points of 0.50, 1.00, 2.00 and 3.00 D. Results Of the sampled people, 5,190 (82.2 per cent) took part in the study. After considering exclusion criteria, data from 4,918 participants were included in the final analysis. Most participants were female (57.6 per cent) and the average age (with standard deviation) was 50.7 ± 6.2 years. The prevalence of anisometropia with cut-off points of 0.50, 1.00 and 2.00 D were 23.1 (95% CI: 22.0-24.3), 7.7 (95% CI: 7.0-8.4) and 3.2 per cent (95% CI: 2.7-3.7), respectively. The prevalence of severe anisometropia (3.00 D or more) was 1.9 per cent (95%CI: 1.5-2.3). The odds ratio ( OR) of anisometropia was 1.06 times higher for every year of increasing age. The OR of anisometropia in participants with cataract was 2.78 times more than in those without (p < 0.001). Anisometropia was more frequent among participants with unilateral cataract (21.7 per cent) compared to those with bilateral cataract (13.4 per cent). Anisometropia of 1.00 D or more was significantly more prevalent among myopic participants compared to hyperopic participants (13.8 versus 12.7 per cent, p < 0.001) and there was a stronger association between anisometropia and myopia ( OR = 2.93) than hyperopia ( OR = 2.23). With increasing educational level, the prevalence of anisometropia decreased significantly (p < 0.001). The prevalence of aniso-astigmatism of 1.00 D or more was 11.1 per cent (95% CI: 10.2-11.9). Conclusion In the present study, the prevalence of anisometropia in Iran was not negligible; however, it is less than in Eastern Asia. Myopia, cataract, age and educational level were associated with anisometropia. [ABSTRACT FROM AUTHOR]

Ledermuelleriopsis punicae sp. nov., collected from soil under pomegranate trees, Punica granatum L. (Lythraceae), Rafsanjan, Kerman Province, and Ledermuelleriopsis ariyai sp. nov., collected from sweet cherry leaves infested with Bryobia rubrioculus (Scheuten) Abbasabad Hamedan, Iran, are described and illustrated. [ABSTRACT FROM AUTHOR]