105 research outputs found

    The need for the development of discipline-specific approaches to address academic bullying

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    Background It is now well-documented that academic bullying, mainly driven by power differences, affects all disci-plines and academic people with various positions (from students to senior faculty) of all levels of experience. Our aim is to probe whether academic bullying, in its specific forms, manifests differently across disciplines. Methods We analyzed discipline-specific data from our global survey on academic bullying, which was collected since November 2019. The survey was a cross-sectional global study that was administered via Qualtrics. It reflects responses from 2122 individuals whose participation was solicited through various means including advertisements in Science and Nature magazines and the American Chemical Society. Findings The main finding is that academic bullying does not affect all scientific fields equally. Our cross-sectional global survey of targets of academic bullying indicates that bullying behavior depended strongly on the scientific dis-cipline. Specifically, our comparison of the three major scientific categories, including Applied Sciences, Natural Sci-ences, and Social Sciences revealed significant differences (p < 0.05) in four (out of ten) of the contextual behaviors. Further comparison of the bullying behavior among specific disciplines (e.g., Chemistry, Engineering, Life Sciences, Neuroscience, and Social Sciences) revealed significant differences (p < 0.05) in five of the contextual behaviors. We also noticed that, among the top five disciplines analyzed, respondents in Engineering experienced the highest rate of bullying behaviors. Interpretation The variation in contextual bullying behavior across disciplines suggests the need for specific and nuanced training, monitoring, and actions by stakeholders in addressing academic bullying in a context-specific manner.Copyright (C) 2022 The Author(s). Published by Elsevier Ltd

    Toxicity of nanomaterials

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    Nanoscience has matured significantly during the last decade as it has transitioned from bench top science to applied technology. Presently, nanomaterials are used in a wide variety of commercial products such as electronic components, sports equipment, sun creams and biomedical applications. There are few studies of the long-term consequences of nanoparticles on human health, but governmental agencies, including the United States National Institute for Occupational Safety and Health and Japan’s Ministry of Health, have recently raised the question of whether seemingly innocuous materials such as carbon-based nanotubes should be treated with the same caution afforded known carcinogens such as asbestos. Since nanomaterials are increasing a part of everyday consumer products, manufacturing processes, and medical products, it is imperative that both workers and end-users be protected from inhalation of potentially toxic NPs. It also suggests that NPs may need to be sequestered into products so that the NPs are not released into the atmosphere during the product’s life or during recycling. Further, non-inhalation routes of NP absorption, including dermal and medical injectables, must be studied in order to understand possible toxic effects. Fewer studies to date have addressed whether the body can eventually eliminate nanomaterials to prevent particle build-up in tissues or organs. This critical review discusses the biophysicochemical properties of various nanomaterials with emphasis on currently available toxicology data and methodologies for evaluating nanoparticle toxicity

    Synthesis, characterization, and evaluation of nano-hydroxyapatite based experimental calcium silicate cement as a root repair material

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    Introduction: This study aimed to prepare a new root repair material including Portland cement, bismuth oxide, and nano-hydroxyapatite and analyze its physicochemical properties and its effects on the proliferation and differentiation of human dental pulp stem cells (hDPSCs). Material and Methods: Bismuth oxide as a radiopaque component and nano-hydroxyapatite particles were added to white Portland cement at 20% and 5% weight ratio, respectively. Characterization of the prepared cement was done using con-ventional methods. To examine the bioactivity of this new material, atomic absorption spectroscopy (AAS) was used for the investigation of the rate of calcium ions dissolution in simulated body fluid media. The viability of hDPSCs was assessed by an MTT assay after 1, 3 and 7 days. The odontogenic potential of this substance was evaluated by measuring alkaline phosphatase activity and alizarin red S staining. Results: Based on the bioactivity results, the cement presented high bio-activity, corroborating sufficiently with the calcium release patterns. The cell viability was significantly increased in new root repair ma-terial containing hydroxyapatite nanoparticles after 3 and 7 days (p<0.05). Conclusion: Moreover, alkaline phosphatase activity increased over 7 days in all experimental groups. The new cement containing nano-hydroxyapatite particles could be a good root repair material

    The possible role of sex as an important factor in development and administration of lipid nanomedicine-based COVID-19 vaccine

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    Nanomedicine has demonstrated a substantial role in vaccine development against severe acute respiratory syndrome coronavirus (SARS-CoV-2 and COVID-19). Although nanomedicine-based vaccines have now been validated in millions of individuals worldwide in phase 4 and tracking of sex-disaggregated data on COVID-19 is ongoing, immune responses that underlie COVID-19 disease outcomes have not been clarified yet. A full understanding of sex-role effects on the response to nanomedicine products is essential to building an effective and unbiased response to the pandemic. Here, we exposed model lipid nanoparticles (LNPs) to whole blood of 18 healthy donors (10 females and 8 males) and used flow cytometry to measure cellular uptake by circulating leukocytes. Our results demonstrated significant differences in the uptake of LNP between male and female natural killer (NK) cells. The results of this proof-of-concept study show the importance of recipient sex as a critical factor which enables researchers to better consider sex in the development and administration of vaccines for safer and more-efficient sex-specific outcomes

    Fabrication and characterization of polycaprolactone fumarate/gelatin-based nanocomposite incorporated with silicon and magnesium co-doped fluorapatite nanoparticles using electrospinning method

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    The aim of this study was to fabricate and characterize biodegradable polycaprolactone fumarate(PCLF)/gelatin-based nanocomposite incorporated with the 0, 5 and 10 wt% silicon and magnesium co-doped fluorapatite nanoparticles (Si -Mg-FA) membranes using electrospinning process for guided bone regeneration (GBR) and guided tissue regeneration (GTR) applications. Results demonstrated the formation of randomly-oriented and defect-free fibers with various fiber sizes depending on the Si -Mg-FA content. Moreover, incorporation of 5 wt% Si -Mg-FA significantly improved the mechanical strength (1.5times) compared to the mechanical strength of PCLF/gelatin membrane and nanocomposite with 10 wt% nanoparticles. There was no clear difference between degradation rate of PCLF/gelatin and PCLF/gelatin with 5 wt% nanoparticles at 7, 14 and 28 days of immersion in phosphate buffer saline while 10 wt% nanoparticles significantly increased biodegradation of PCLF/gelatin, and no cytotoxic effect of membranes was seen. Finally, scanning electron microscopy (SEM) micrographs of fibroblast cells cultured on the samples demonstrated that the cells were completely attached and spread on the surface of nanocomposites. In summary, PCLF/gelatin membranes consisting of 5 wt% Si -Mg-FA nanoparticles could provide appropriate mechanical and biological properties and fairly good degradation rate, making it appropriate for GTR/GBR applications

    The inhibitory effect of 6-gingerol and cisplatin on ovarian cancer and antitumor activity: In silico, in vitro, and in vivo

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    © 2023 Salari, Khosravi, Pourkhandani, Molaakbari, Salarkia, Keyhani, Sharifi, Tavakkoli, Sohbati, Dabiri, Ren and Shafie’ei. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). https://creativecommons.org/licenses/by/4.0/Background: Epithelial ovarian cancer is very common in women and causes hundreds of deaths per year worldwide. Chemotherapy drugs including cisplatin have adverse effects on patients’ health. Complementary treatments and the use of herbal medicines can help improve the performance of medicine. 6-Gingerol is the major pharmacologically active component of ginger. In this study, we compared the effects of 6-gingerol, cisplatin, and their combination in apoptotic and angiogenetic activities in silico, in test tubes, and in in vivo assays against two ovarian cancer cell lines: OVCAR-3 and human umbilical vein endothelial cells (HUVECs). Methods: The drug-treated cell lines were evaluated for their cytotoxicity, cell cycle, and apoptotic and angiogenetic gene expression changes. Results: The proportion of apoptosis treated by 6-gingerol coupled with cisplatin was significantly high. In the evaluation of the cell cycle, the combination therapy also showed a significant promotion of a higher extent of the S sequence. The expression of p53 level, Caspase-8, Bax, and Apaf1 genes was amplified again with combination therapy. Conversely, in both cell lines, the cumulative drug concentrations reduced the expression of VEGF, FLT1, KDR, and Bcl-2 genes. Similarly, in the control group, combination treatment significantly decreased the expression of VEGF, FLT1, KDR, and Bcl-2 genes in comparison to cisplatin alone. Conclusions: The findings of the present study demonstrated that the cisplatin and 6-gingerol combination is more effective in inducing apoptosis and suppressing the angiogenesis of ovarian cancer cells than using each drug alone.Peer reviewe

    Comparison of cytotoxicity of Miltefosine and its niosomal form on chick embryo model

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    © 2024 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Various drugs have been used for the treatment of leishmaniasis, but they often have adverse effects on the body's organs. In this study, we aimed to explore the effects of one type of drug, Miltefosine (MIL), and its analogue or modifier, liposomal Miltefosine (NMIL), on several fetal organs using both in silico analysis and practical tests on chicken embryos. Our in silico approach involved predicting the affinities of MIL and NMIL to critical proteins involved in leishmaniasis, including Vascular Endothelial Growth Factor A (VEGF-A), the Kinase insert domain receptor (KDR1), and apoptotic-regulator proteins (Bcl-2-associate). We then validated and supported these predictions through in vivo investigations, analyzing gene expression and pathological changes in angiogenesis and apoptotic mediators in MIL- and NMIL-treated chicken embryos. The results showed that NMIL had a more effective action towards VEGF-A and KDR1 in leishmaniasis, making it a better candidate for potential operative treatment during pregnancy than MIL alone. In vivo, studies also showed that chicken embryos under MIL treatment displayed less vascular mass and more degenerative and apoptotic changes than those treated with NMIL. These results suggest that NMIL could be a better treatment option for leishmaniasis during pregnancy.Peer reviewe
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