109 research outputs found
Reliability and Performance Analysis of a Fault Tolerant Data Handling Protocol for Aerospace Applications
Data communication inside the satellite is one of the most important factors in satellite design. For this purpose, a variety of protocols have been developed in recent years. Controller Area Network (CAN) is one of the well-developed protocols to be used in the On-Board Data Handling (OBDH) systems for communication and geosynchronous satellites. Nonetheless, for aerospace applications which demand radiation hardened integrated circuits, a full featured stand-alone Rad-Hard CAN controller is unavailable. HDL (Hardware Description Language) based IP(Intellectual Property) Cores which are widely developed to be implemented on Rad-Hard FPGAs are more attractive. This paper proposes a novel fault tolerant CAN controller based on FPGAs to provide on-board data handling requirements of the communication satellites. We outline some practical topologies and discuss their complexities and reliability. Despite the fact that the most famous methods like TMR (Triple Modular Redundancy), are very common among designers, the reliability analyses show that these methods are unable to tolerate single upsets in routing matrixes. This paper proposes a robust data bus controller based on dual duplex redundancy on FPGAs. The fault injection experiments reveal that the proposed approach represents better performance respective to the conventional hardware redundancy. Furthermore, the experiments show that the capability of tolerating SEU effects by the proposed method is increased up to 7.17 times with respect to a regular design. The proposed architecture imposes 16.26% and 5.2% overhead in the required resources and the operating frequency in comparison to the regular TMR method
Biological impact of advanced glycation endproducts on estrogen receptor-positive MCF-7 breast cancer cells.
Diabetes mellitus potentiates the risk of breast cancer. We have previously described the pro-tumorigenic effects of advanced glycation endproducts (AGEs) on estrogen receptor (ER)-negative MDA-MB-231 breast cancer cell line mediated through the receptor for AGEs (RAGE). However, a predominant association between women with ER-positive breast cancer and type 2 diabetes mellitus has been reported. Therefore, we have investigated the biological impacts of AGEs on ER-positive human breast cancer cell line MCF-7 using in vitro cell-based assays including cell count, migration, and invasion assays. Western blot, FACS analyses and quantitative real time-PCR were also performed. We found that AGEs at 50-100μg/mL increased MCF-7 cell proliferation and cell migration associated with an enhancement of pro-matrix metalloproteinase (MMP)-9 activity, without affecting their poor invasiveness. However, 200μg/mL AGEs inhibited MCF-7 cell proliferation through induction of apoptosis indicated by caspase-3 cleavage detected using Western blotting. A phospho-protein array analysis revealed that AGEs mainly induce the phosphorylation of extracellular-signal regulated kinase (ERK)1/2 and cAMP response element binding protein-1 (CREB1), both signaling molecules considered as key regulators of AGEs pro-tumorigenic effects. We also showed that AGEs up-regulate RAGE and ER expression at the protein and transcript levels in MCF-7 cells, in a RAGE-dependent manner after blockade of AGEs/RAGE interaction using neutralizing anti-RAGE antibody. Throughout the study, BSA had no effect on cellular processes. These findings pave the way for future studies investigating whether the exposure of AGEs-treated ER-positive breast cancer cells to estrogen could lead to a potentiation of the breast cancer development and progression
Induction of protein citrullination and auto-antibodies production in murine exposed to nickel
Abstract Citrullination, or the post-translational deimination of polypeptide-bound arginine, is involved in several pathological processes in the body, including autoimmunity and tumorigenesis. Recent studies have shown that nanomaterials can trigger protein citrullination, which might constitute a common pathogenic link to disease development. Here we demonstrated auto-antibody production in serum of nanomaterials-treated mice. Citrullination-associated phenomena and PAD levels were found to be elevated in nanomaterials -treated cell lines as well as in the spleen, kidneys and lymph nodes of mice, suggesting a systemic response to nanomaterials injection, and validated in human pleural and pericardial malignant mesothelioma (MM) samples. The observed systemic responses in mice exposed to nanomaterials support the evidence linking exposure to environmental factors with the development of autoimmunity responses and reinforces the need for comprehensive safety screening of nanomaterials. Furthermore, these nanomaterials induce pathological processes that mimic those observed in Pleural MM, and therefore require further investigations into their carcinogenicity
Safety assessment and behavioral effects of Solanum guaraniticum leaf extract in rats
ABSTRACT Solanum guaraniticum is a medicinal plant traditionally used to treat gastric and liver diseases. However, there is no documented evidence corroborating its safety. The present study evaluated the potential toxicity of S. guaraniticum leaf extract after acute administration in rats. Single doses of the extract (1.250, 2.500, and 5.000 mg/kg) were administered by gavage, and the rats were then monitored for 48 h and/or 14 days. Mortality, acute signs of toxicity, and general activity in the open field test were assessed as well as hematological and biochemical parameters, enzymatic activity (δ-aminolevulinate dehydratase and acetylcholinesterase), and oxidative stress parameters (lipid peroxidation level, non-protein thiol content, tissue catalase activity, and serum ferrous reducing power). Phytochemical analysis was also performed by HPLC. The results showed that extract administration produced no deaths (LD50 > 5,000 mg/kg), and no significant adverse effects regarding food consumption, body weight gain, gross pathology, or other parameters. However, the open field tests showed a decrease in spontaneous activity (crossing and rearing) mainly at 48 h after treatment. The results suggest that S. guaraniticum extract is not acutely toxic, but causes alterations in central nervous system activity
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