50 research outputs found

    Soil Washing of Fluorine Contaminated Soil Using Various Washing Solutions

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    Bench-scale soil washing experiments were conducted to remove fluoride from contaminated soils. Five washing solutions including hydrochloric acid (HCl), nitric acid (HNO3), sodium hydroxide (NaOH), sulfuric acid (H2SO4) and tartaric acid (C4H6O6) were tested. The concentration of the washing solutions used ranged from 0.1 M to 3 M with a liquid to solid ratio of 10. The soil washing results showed that the most effective washing solution for the removal of fluoride from contaminated soils was HCl. The highest fluoride removal results of approximately 97% from the contaminated soil were obtained using 3M HCl. The fluoride removal efficiency of the washing solution increases in the following order: C4H6O

    The R∞ property for Houghton's groups

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    We study twisted conjugacy classes of a family of groups which are called Houghton's groups Hn (n∈N), the group of translations of n rays of discrete points at infinity. We prove that the Houghton's groups Hn have the R∞ property for all n∈N

    Characteristics of Type 2 Diabetes in Terms of Insulin Resistance in Korea

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    The aim of this study was to assess the implications of insulin resistance on the clinical and biochemical profiles of Korean type 2 diabetic patients. 122 patients with type 2 diabetes underwent a short insulin tolerance test to assess insulin resistance. Subjects were classified in tertiles according to ISI (insulin sensitivity index), and the tertile I (the insulin-resistant group) and tertile III (the insulin-sensitive group) clinical and biochemical parameters were compared. Age, waist circumference (WC), systolic blood pressure (SBP), HbA1c, body fat content, and fasting plasma glucose were significantly higher in tertile I than tertile III (all p < 0.05). The frequency of hypertension and family history of cerebrovascular disease (CVD) were greater in tertile I than III (p < 0.05). To evaluate the factors affecting ISI, multiple regression was performed, and age, WC, SBP, HbA1c, and body fat content were found to be independently related to insulin resistance (p < 0.05). Old age, hypertension, central obesity, and poor glycemic control were identified as clinical parameters of insulin resistance in Korean type 2 diabetic patients

    Corticobulbar motor evoked potentials from tongue muscles used as a control in cervical spinal surgery

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    Objective: Motor evoked potentials (MEPs) changes might be caused to the non-surgically induced factors during cervical spinal surgery. Therefore, control MEPs recorded cranially to the exit of the C5 root are highly recommendable in cervical spinal surgery. We studied whether corticobulbar MEPs (C-MEPs) from tongue muscle could be used as a control MEPs in cervical spinal surgery. Methods: Twenty-five consecutive cervical spinal surgeries were analyzed. Stimulation of motor area for tongue was done by subcutaneous electrodes placed at C3/C4 (10–20 EEG System), and recording was done from both sides of tongue. Results: C-MEPs were recorded successfully 24 out of the 25 (96%) tested patients. Forty-six out of fifty MEPs (92%) from tongue muscles were monitorable from the baseline. In two patients, we could obtain only unilateral C-MEPs. Mean MEPs latencies obtained from the left and right side of the tongue were 11.5 ± 1 ms and 11.5 ± 0.8 ms, respectively. Conclusions: Monitoring C-MEPs from tongue muscles might be useful control in cervical spinal surgery. They were easily elicited and relatively free from phenomenon of peripheral stimulation of the hypoglossal nerves. Significance: This is first study to identify the usefulness of C-MEPs as a control of cervical spinal surgery. Keywords: Intraoperative neurophysiological monitoring, Motor-evoked potential, Corticospinal tract, Corticobulbar MEPs, Hypoglossal nerv

    Inhibition of cell invasion and migration by targeting matrix metalloproteinase-9 expression via sirtuin 6 silencing in human breast cancer cells

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    Abstract Sirtuin 6 (SIRT6) regulation is involved in carcinogenesis. However, its role in breast cancer (BC) metastasis remains unclear. We investigated the effects of SIRT6 on protein kinase C activator- and cytokine-mediated cancer cell invasion and migration in MCF-7 and MDA-MB-231 cells and the association between SIRT6 and matrix metalloproteinase-9 (MMP-9) expression. To assess MMP-9 and SIRT6 expression in patients, protein levels in BC tissues were analyzed. MCF-7 and MDA-MB-231 cell viability was analyzed using MTT assays. SIRT6 was silenced in both cell lines and protein secretion, expression, and mRNA levels were analyzed. Transcription factor DNA activity was investigated using luciferase assays. Matrigel invasion assays were used to assess the effects of SIRT6 in both cell lines. SIRT6 and MMP-9 expression in cancer tissues was significantly higher than in paired normal breast tissues. 12-O-tetradecanoylphorbol-13-acetate (TPA) or tumor necrosis factor-α (TNF-α) increased MMP-9 expression and cell invasion and migration, but SIRT6 knockdown abolished these effects. SIRT6 overexpression additively increased TPA- and TNF-α-induced MMP-9 expression. SIRT6 knockdown suppressed the mitogen-activated protein kinase (MAPK) signaling pathway and thus TPA- and TNF-α-induced MMP-9 expression. SIRT6 silencing suppressed TPA- and TNF-α-induced nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) expressions in both cell lines, and treatment with MAPK, NF-κB, and AP-1 inhibitors reduced MMP-9 expression. The anti-invasive effects of SIRT6 in BC cells might be mediated by suppression of MAPK phosphorylation and reduction in NF-κB and AP-1 DNA activities, leading to MMP-9 downregulation, suggesting that SIRT6 modulation has the potential to target BC metastasis

    Toxicity and Biokinetics of Colloidal Gold Nanoparticles

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    Gold nanoparticles (Au-NPs) have promising potential for diverse biological application, but it has not been completely determined whether Au-NP has potential toxicity in vitro and in vivo. In the present study, toxicity of Au-NP was evaluated in human intestinal cells as well as in rats after 14-day repeated oral administration. Biokinetic study was also performed to assess oral absorption and tissue distribution. The results demonstrated that Au-NP did not cause cytotoxic effects on cells after 24 h exposure in terms of inhibition of cell proliferation, membrane damage, and oxidative stress. However, when a small number of cells were exposed to Au-NP for seven days, colony forming ability remarkably decreased by Au-NP treatment, suggesting its potential toxicity after long-term exposure at high concentration. Biokinetic study revealed that Au-NP slowly entered the blood stream and slightly accumulated only in kidney after oral administration to rats. Whereas, orally administered Au ions were rapidly absorbed, and then distributed in kidney, liver, lung, and spleen at high levels, suggesting that the biological fate of Au-NP is primarily in nanoparticulate form, not in ionic Au. Fourteen-day repeated oral toxicity evaluation showed that Au-NP did not cause severe toxicity in rats based on histopathological, hematological, and serum biochemical analysis

    Multi-channel motor evoked potential monitoring during anterior cervical discectomy and fusion

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    Objectives: Anterior cervical discectomy and fusion (ACDF) surgery is the most common surgical procedure for the cervical spine with low complication rate. Despite the potential prognostic benefit, intraoperative neurophysiological monitoring (IONM), a method for detecting impending neurological compromise, is not routinely used in ACDF surgery. The present study aimed to identify the potential benefits of monitoring multi-channel motor evoked potentials (MEPs) during ACDF surgery. Methods: We retrospectively reviewed 200 consecutive patients who received IONM with multi-channel MEPs and somatosensory evoked potentials (SSEPs). On average, 9.2 muscles per patient were evaluated under MEP monitoring. Results: The rate of MEP change during surgery in the multi-level ACDF group was significantly higher than the single-level group. Two patients from the single-level ACDF group (1.7%) and four patients from the multi-level ACDF group (4.9%) experienced post-operative motor deficits. Multi-channel MEPs monitoring during single and multi-level ACDF surgery demonstrated higher sensitivity, specificity, positive predictive and negative predictive value than SSEP monitoring. Conclusions: Multi-channel MEP monitoring might be beneficial for the detection of segmental injury as well as long tract injury during single- and multi-level ACDF surgery. Significance: This is first large scale study to identify the usefulness of multi-channel MEPs in monitoring ACDF surgery. Keywords: Disc disease, Somatosensory evoked potentials, Intraoperative neurophysiological monitoring, Motor evoked potentials, Anterior cervical discectomy and fusio

    Effect of Copper Chelators via the TGF-β Signaling Pathway on Glioblastoma Cell Invasion

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    Glioblastoma multiforme (GBM) is a fast-growing and aggressive type of brain cancer. Unlike normal brain cells, GBM cells exhibit epithelial–mesenchymal transition (EMT), which is a crucial biological process in embryonic development and cell metastasis, and are highly invasive. Copper reportedly plays a critical role in the progression of a variety of cancers, including brain, breast, and lung cancers. However, excessive copper is toxic to cells. D-penicillamine (DPA) and triethylenetetramine (TETA) are well-known copper chelators and are the mainstay of treatment for copper-associated diseases. Following treatment with copper sulfate and DPA, GBM cells showed inhibition of proliferation and suppression of EMT properties, including reduced expression levels of N-cadherin, E-cadherin, and Zeb, which are cell markers associated with EMT. In contrast, treatment with copper sulfate and TETA yielded the opposite effects in GBM. Genes, including TGF-β, are associated with an increase in copper levels, implying their role in EMT. To analyze the invasion and spread of GBM, we used zebrafish embryos xenografted with the GBM cell line U87. The invasion of GBM cells into zebrafish embryos was markedly inhibited by copper treatment with DPA. Our findings suggest that treatment with copper and DPA inhibits proliferation and EMT through a mechanism involving TGF-β/Smad signaling in GBM. Therefore, DPA, but not TETA, could be used as adjuvant therapy for GBM with high copper concentrations
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