تفکر مراقبتی در برنامه فلسفه برای کودکان با تأکید بر ارزشها و عواطف، رشد اخلاقی و اجتماعی را تقویت میکند. از این رو، پژوهش حاضر اثربخشی داستانهای ایرانی گروه سنی «ج» را در حلقههای کندوکاو فلسفی بر تفکر مراقبتی دانشآموزان پایه ششم ابتدایی بررسی نموده است. این پژوهش با روش نیمهآزمایشی و طرح پیشآزمون-پسآزمون در سال تحصیلی ۱۴۰۳-۱۴۰۴ در شهر اصفهان اجرا شد. جامعه آماری شامل دانشآموزان پایه ششم شهر اصفهان در سال تحصیلی ۱۴۰۳-۱۴۰۴ بود که ۶۰ دانشآموز پسر به روش نمونهگیری خوشهای مرحلهای انتخاب و به دو گروه آزمایش و کنترل (هر گروه ۳۰ نفر) تخصیص یافتند. مداخله در ۱۰ جلسه با داستانهای پرفروش ایرانی (۱۳۹۵-۱۴۰۳) اجرا شد. دادهها با استفاده از پرسشنامه هدایتی (۱۳۹۷) جمعآوری و با روش تحلیل کوواریانس تکمتغیره و چندمتغیره با نرمافزار SPSS 26 تحلیل شدند. یافتهها نشان داد میانگین تفکر مراقبتی گروه آزمایش از ۹۴/۸۰ به ۱۰۵/۴۷ رسیده است. در حالی که تحلیل کوواریانس تکمتغیره تفاوت غیرمعناداری را نشان داد و آزمون بنفرونی نیز تفاوت غیرمعناداری را تأیید کرد، کوواریانس چندمتغیره تفاوت کلی مؤلفهها را تأیید نکرد، اما اثرات بینآزمونی بهبود معنادار مؤلفه تفکر همدلانه (p<0.05) را نشان داد. در نتیجه، داستانهای ایرانی تفکر مراقبتی را بهویژه مؤلفه تفکر همدلانه ارتقا میدهند و پیشنهاد میشود تسهیلگران فبک در حلقههای کندوکاو از این منابع بهره گیرند و پژوهشهای آتی اثرات بلندمدت این داستانها بر تفکر مراقبتی دانشآموزان را بررسی کنند.
Given the widespread use of caffeine among athletes, this meta-analysis quantifies the incidence of acute side effects associated with caffeine supplementation. Despite its well-established performance benefits, evidence on caffeine’s side effects remains fragmented, as these outcomes are often reported only as secondary findings. To address this gap, we systematically reviewed and meta-analyzed evidence from randomized controlled trials on acute caffeine-related side effects in athletes. Following PRISMA guidelines, we searched five databases (MEDLINE, Scopus, Web of Science, Embase, Google Scholar) up to July 2025. Eligible studies were randomized controlled trials in athletes aged ≥ 15 years examining acute caffeine ingestion versus placebo with reported side effects. Risk of bias was assessed using PEDro and Cochrane criteria. Data on frequency and magnitude of side effects were pooled using random-effects meta-analyses, with subgroup and dose–response analyses. A total of 48 studies (940 athletes; 63
Dye-sensitized solar cells (DSSCs) represent a promising technology for sustainable energy conversion; however, their performance optimization demands considerable experimental and computational effort. This study employs density functional theory (DFT) and time-dependent DFT (TD-DFT) to investigate the optoelectronic and photovoltaic properties of a C2N monolayer quantum dot and its complexes with two organic dyes including T2-1 and para-methyl red (PMR). Six dye/C2N configurations (T1-T3 and P1-P3) were computationally analyzed for their electronic structure, intramolecular charge transfer (ICT), and interaction with TiO2 electrodes. Key photovoltaic descriptors were evaluated to predict the device performance. Results revealed that the complexation of the dyes with C2N significantly enhances the light-harvesting efficiency, charge separation, and electron injection kinetics compared to those of isolated dyes on the TiO2 electrode. The calculated gas-phase values of short-circuit current densities and open-circuit voltages for T1, T3, P2, and P3 vary in the ranges of 51 to 53 mA cm-2 and 54 to 58 V, respectively, which shows their suitable photovoltaic performance for application in DSSCs. On the other hand, the T3 complex shows the highest open-circuit voltage (0.33 V) among the complexes while the highest short-circuit current densities (87.38 mA cm-2) is for the T1 complex in solvent (acetonitrile). The findings validate C2N as a viable photoanode material, and a cosensitizer demonstrated the efficacy of theoretical screening in improving DSSC performance.
Nowadays, salt stress considered an important environmental challenge for the agriculture which is aggravated by global warming, thereby, markedly decreasing the biomass production and crop yield worldwide. Nanoparticles are widely applied to strengthen plants against environmental stresses. Carbon based nano-chemicals and especially carbon dots (CDs) are regarded as highly beneficial nanoparticles for applications in agriculture thanks to their properties. CDs generated from urea and citric acid in this research demonstrated great physico-chemical characteristics consisting of biocompatibility, strong fluorescence, solubility in water and functional groups on their surface. In this study, CDs were employed to improve the salt tolerance of tomato as a physiological model plant. Salt stress reduced the fresh biomass and total height of tomato seedlings. Further, proline and the total content of carbohydrates increased to adjust the osmotic potential of cytoplasm facing high NaCl levels. Salinity heavily declined seed germination indices as well. Contrary to salt-treated seedlings, incubation with CDs had positive effects on preliminary physiological parameters i.e. growth and total length in salt-stressed and non-stressed plants. Likewise, some osmotic balancing markers including proline and carbohydrates considerably increased in combined CDs- and NaCl-treated plants relative to salt-exposed ones. Further, the ameliorating influence of CDs on seed germination percentage and rate was noticed in salinity exposed seeds. Thus, CDs are appropriate candidates providing an efficient approach in developing modern and acclimatized agriculture and increasing crop yield.
Polymethyl methacrylate (PMMA) bone cement is widely used in orthopaedic procedures but suffers from limited bioactivity, hindering bone integration. To overcome this, a bioactive nanocomposite was developed by incorporating akermanite (Ca2MgSi2O7) and graphene oxide (GO) into PMMA. Four formulations were prepared: PMMA, PMMA/Akermanite, PMMA/Akermanite/GO and PMMA/GO. Bioactivity was evaluated via 28 days of immersion in simulated body fluid, with SEM confirming hydroxyapatite formation on the akermanite-containing composites. Akermanite also imparts partial biodegradability to the composite. Mechanical testing revealed a 12.5% increase in the compressive modulus with akermanite addition, which was further enhanced by the addition of 1 wt% GO (similar to 1518 MPa modulus, 33.7% strain, 72.5 MPa yield strength). MTT assays using MG-63 cells demonstrated enhanced viability, adhesion and proliferation. These results indicate that the PMMA/Akermanite/GO nanocomposite effectively improves bioactivity, mechanical performance, biodegradability and the cellular response, making it a promising candidate for load-bearing orthopaedic applications and clinical bone repair. [GRAPHICS] .
