211 research outputs found

    Moving Transportation toward Sustainable Development: The Need for a Paradigm Shift

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    Despite progress in controlling exhaust emissions, the increase of cars on the road will surpass progress in emission control technology. The automobile is currently responsible for 50% of world fossil fuel consumption, 15-20% of CO2 emissions worldwide and overwhelming particulate air pollution in many urban centers. Current efforts in emissions control have been focused on improving the efficiency of fuels and automobiles and their emissions. However, as a mode of transportation, the automobile is one of the most inefficient, both in environmental and economic costs. Even the most efficient cars developed today will still significantly contribute to the amount of global greenhouse gases based on the current rate of increase in automobile usage. Current trends in automobile development and research are not sustainable. This paper describes some novel approaches to offset and reduce automobile emissions that are currently under study

    Modeling of Power Losses Caused by Hidden Tree-Related High Impedance Faults

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    The great majority of overhead distribution systems in urban and rural areas of countries such as Australia, Iran and etc., are in interfering with vegetation. This phenomena leads to high impedance faults (HIFs) which not produce enough fault current to be detectable and consequently causes electrical energy losses. In this paper, according to experimental data obtained from measurements, the effective factors in power losses caused by trees are studied and a new numerical model of power loss is presented so as to reflect the effects of environmental conditions and biological classification. The base of this method is according to Samuelson theory. In proposed algorithm, the impacts of species, short-term environmental conditions (temperature and humidity) and long-term environmental conditions (Seasonal variations in physiology) on the power loss estimation are fully considered. Experimental investigations on a real low voltage (380 V) and medium voltage (20 kV) distribution network verify the algorithm\u27s operation

    Attenuation of Aggregatibacter actinomycetemcomitans virulence using curcumin-decorated nanophytosomes-mediated photo-sonoantimicrobial chemotherapy

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    This study aimed to focus on the simultaneous use of antimicrobial photodynamic therapy (aPDT) and sonodynamic antimicrobial chemotherapy (SACT), which is called photo-sonodynamic antimicrobial chemotherapy (PSACT) to attenuate the virulence of Aggregatibacter actinomycetemcomitans. Following the synthesis of Curcumin-decorated nanophytosomes (Cur-NPhs) as a novel photo-sonosensitizer, its particle size, polydispersity, ζ-potential surface morphology, physical stability, drug release, and entrapment efficiency were determined. In the Cur-NPhs-PSACT, the antimicrobial activities of Cur-NPhs against A. actinomycetemcomitans were investigated using cell viability, biofilm killing/degradation, metabolic activity, expression of quorum-sensing-associated qseB and qseC genes, and biofilm-associated rcpA gene under blue laser irradiation plus ultrasonic waves. Characterization tests showed the presence of a sphere-shaped vesicle and the self-closed structure of Cur-NPhs, resulting in a high drug-loading content and encapsulation efficiency. However, the antimicrobial effect of Cur-NPhs-PSACT was dose-dependent, PSACT using the high concentrations of Cur-NPhs (50 � 10�4 g/L) showed significant reductions (P < 0.05) in cell viability (13.6 log10 CFU/mL), biofilm killing/degradation (65), metabolic activity (89.6,), and mRNA levels of virulence determinant genes (qseB; 9.8-fold, qseC; 10.2-fold, and recA; 10.2-fold). This study concludes that the Cur-NPhs-PSACT had antimicrobial activities against A. actinomycetemcomitans by downregulating the expression of virulence genes, and may attenuate this bacterium that decreases periodontal disease severity in patients. © 2021, The Author(s)

    Down-regulation of microRNA-26a and up-regulation of microRNA-27a contributes to aggressive progression of human osteosarcoma

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    Background: Osteosarcoma is the most common primary bone malignancy with high local aggressiveness and rapid metastasizing potential, resulting in poor survival. Increasing reports suggest that deregulated microRNAs (miRNAs) might provide novel therapeutic targets for cancers. However, the expression of miR-26a and miR-27a in osteosarcoma need further investigation in clinical samples. In our study, we evaluate the expression of these miRNAs in osteosarcoma tissues and compared with paired adjacent non-tumor bone tissues using RT-qPCR. Methods: Total RNA was purified from patients with osteosarcoma and noncancerous bone tissues. Real-time PCR was applied to quantify the expression level of miR-26a and miR-27a. Moreover, the correlation of these markers with clinicopathological characteristics was also evaluated in osteosarcoma patients. A cox proportional hazards model was performed to assess multivariate analyses of prognostic values. Results: Our result suggested that miR-26aexpression level in osteosarcoma bone tissue was significantly lower than that in the paired noncancerous bone tissues. MiR-27a expression was higher in osteosarcoma bone tissue in comparison with paired noncancerous bone tissues. The results indicated that low expression level of miR-26a and high expression of miR-27a were associated with high TNM stage (P = 0.001; P = 0.012), tumor grade (P = 0.007; P = 0.016), and distant metastasis (P = 0.004; P = 0.001). Kaplan-Meier analysis and log-rank test indicated that patients with low expression of miR-26a and high expression of miR-27a had shorter overall survival (log-rank test: P < 0.001). Multivariate Cox proportional hazards model analysis showed that low expression of miR-26a and high expression of miR-27a (P = 0.021; P = 0.011), high TNM stage (P = 0.001; P = 0.003), tumor grade (P = 0.005; P = 0.01), and distant metastasis.(P = 0.002; P = 0.005) were independent prognostic factors for overall survival patients with osteosarcoma cancer. Conclusions: In conclusion, our findings suggested that expression level of miR-26a and miR-27a contributes to aggressive progression of this malignancy. Therefore, may have clinical potentials as a non-invasive diagnostic/prognostic biomarker for osteosarcoma patients. © 2015 Taheriazam et al

    Assessment of heavy metals contamination in surface sediments of Shoor River estuary, east of Bandar Abbas by using different indexes

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    Toxicity of trace metals in the environment, bioaccumulation in aquatic environments and in food chains are of great importance.This study concentrates on the distribution patterns of some heavy metals (Pb, Ni, Zn and Fe) in surface sediments of Shoor River estuary. In order to determine the degree of Contamination and environmental quality of region sediments, surface sediment (0-5 cm) samples were collected from 4 stations. At each station, three surface sediment samples were collected and the concentration of heavy metals were measured using a flame Atomic Absorption Spectrophotometer; Then indexes such as the Pollution Load Index (PLI) and Potential ecological risk index (RI) for each of the sampling stations and study area applied. The results of PLI represented the low accumulation of studied metals in the surface sediments of the area. Potential ecological risk was also low. The results indicated that Zn and Ni were mainly from anthropogenic discharge, while a significant portion of Pb and Fe were likely from natural inputs. Overall, frequent adverse effects were expected for Ni and occasional adverse biological effects are expected for Zn, whereas for Pb and Fe rare adverse biological effects are expected. Pearson’s correlation indicated that there was positive correlation between Ni, Pb, Fe, TOM and fine grain size (p<0.01). Nevertheless, due to rapid urbanization and industrial development of Bandar Abbas, monitoring of heavy metals contamination in the study area due to its ecological importance is necessary

    The decrease in NKG2D+ Natural Killer cells in peripheral blood of patients with metastatic colorectal cancer

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    Background: Natural killer (NK) cells play important roles in the immune defense against tumors such as colorectal cancer. In humans, NKG2D is an activating immune receptor constitutively expressed in most cytotoxic lymphocytes including NK and CD8+ T cells. In this study, the expression of NKG2D molecule was investigated in peripheral blood NK cells from colorectal cancer patients and compared with healthy subjects. Methods: We studied 21 non-metastatic (low-grade), 17 non-metastatic (high-grade), 16 metastatic colorectal cancer patients, and 24 healthy controls. Peripheral blood samples were obtained to isolate peripheral blood mononuclear cells (PBMCs) and the percentage of peripheral blood NKG2D+CD3-CD56+ NK cells was analyzed by flow cytometry. The expression of NKG2D at mRNA level was also measured by real-time PCR in both, patients and control subjects. Results: The results showed a significant reduction in the percentage of NKG2D+NK cells as well as NKG2D mRNA expression in peripheral blood of metastatic colon cancer patients. Conclusion: This result suggests that decreased expression of activating NKG2D receptor in metastatic colorectal cancer might compromise NK cell function and allow tumor to evade immunity (Tab. 3, Fig. 4, Ref. 33). Text in PDF www.elis.sk

    Downregulation of microRNA-217 and microRNA-646 acts as potential predictor biomarkers in progression, metastasis, and unfavorable prognosis of human osteosarcoma

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    Despite the progress in therapeutic targets, it remains dissatisfactory for most osteosarcoma patients with metastasis or recurrence osteosarcoma. Therefore, it is required to determine the involved mechanisms of osteosarcoma. The aim of this study was to investigate the expression level of MiR-217 and miR-646 and also their association with clinicopathological features in patients with osteosarcoma. Total RNA was purified from patients with osteosarcoma and noncancerous bone tissues, and then quantitative real-time PCR was applied to evaluate the expression level of microRNAs. Our result suggested that miR-217 expression was remarkably deceased in osteosarcoma bone tissue when compared with noncancerous bone tissues (mean ± SD 5.32 ± 1.231, 2.01 ± 0.78; P = 0.024) and miR-646 expression decreased in osteosarcoma bone tissue in comparison with normal tissues (mean ± SD 4.56 ± 1.45, 1.76 ± 1.24; P = 0.041). Our findings indicated that decreased expression of MiR-217 and miR-646 was strongly correlated with high tumor, node, and metastasis (TNM) stage (P = 0.015, P = 0.002) and large cancer diameter (P = 0.041, P = 0.053). Kaplan-Meier survival and log-rank analysis indicated that shorter overall survival was strongly linked to decreased expression of miR-217 and miR-646 (log-rank test P = 0.034, P = 0.026). In terms of miR-217, multivariate Cox proportional hazards model analysis has showed that reduction of miR-217 expression (P = 0.001), TNM stage (P = 0.046), and lymph node metastasis (P = 0.006) were independently linked to a short-time survival of patients. In terms of miR-646, low expression of miR-646 (P = 0.021), TNM stage (P = 0.052), and tumor size (P = 0.043) were independently associated with poor survival of patients as prognostic factors. Our findings suggested that downregulation of MiR-217 and miR-646 was associated with progression of osteosarcoma. MiR-217 and miR-646 may play a key role in suppression of tumor in osteosarcoma and would be applied as a novel therapeutic agent. © 2015, International Society of Oncology and BioMarkers (ISOBM)

    Retraction Note to: Downregulation of microRNA-217 and microRNA-646 acts as potential predictor biomarkers in progression, metastasis, and unfavorable prognosis of human osteosarcoma (Tumor Biol, (2016), 37, (5769-5773), 10.1007/s13277-015-3821-4)

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    This article has been retracted at the request of the Editor-in-Chief, the International Society of Oncology and BioMarkers (ISOBM) and the Publisher per the Committee on Publication Ethics guidelines. The article shows evidence of irregularities in authorship during the submission process, there is strong reason to believe that the peer review process was compromised and there are similarities with the following articles which were all submitted within a close timeframe: Masoomeh Dadpay, Mojtaba Zarea, Rahman Ghaffarzadegan Rabati, Bijan Rezakhaniha, Babak Barari, Vahid Behnod, Katayoun Ziari, Upregulation of miR-21 and downregulation of miR-494 may serve as emerging molecular biomarkers for prediagnostic samples of subjects who developed nasopharyngeal carcinoma associates with lymph node metastasis and poor prognosis. Tumor Biol. First Online: 21 August 2015 DOI: 10.1007/s13277-015-3905-1 Date received: 27 June 2015 Seyyed Hasan Karbasy, Afshin Taheriazam, Alireza Mirghasemi, Farnoush Sedaghati, Mohammadreza Shakeri, Emad Yahaghi, Reza Bahador, Upregulation of miR-300 and downregulation of miR-125b act as potential predictor biomarkers in progression, metastasis, and poor prognosis of osteosarcoma. Tumor Biol. First Online: 02 September 2015 DOI: 10.1007/s13277-015-4000-3. © 2016, International Society of Oncology and BioMarkers (ISOBM)
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