478 research outputs found

    Magnesium isotopic composition of the oceanic mantle and oceanic Mg cycling

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    © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 206 (2017): 151-165, doi:10.1016/j.gca.2017.02.016.To constrain the Mg isotopic composition of the oceanic mantle, investigate Mg isotope fractionation of abyssal peridotites during seafloor alteration, and assess Mg budget in the oceans, a suite of 32 abyssal peridotite samples from the Gakkel Ridge and Southwest Indian Ridge (SWIR) was, for the first time, selected for high-precision Mg isotope analyses. Although most of these samples are extensively altered, largely by serpentinization and weathering, primary olivine, diopside and enstatite grains are preserved in some samples. Olivine grains from the least altered samples have ÎŽ26Mg varying from −0.30 to −0.12‰ (n = 7), whereas enstatite and diopside have ÎŽ26Mg varying from −0.27 to −0.16‰ (n = 7), and from −0.23 to −0.09‰ (n = 6), respectively. Whole-rock ÎŽ26Mg values range from −0.24 to 0.03‰ with an average of −0.12 ± 0.13‰ (2SD, n = 32). Strongly serpentinized peridotites have lower average ÎŽ26Mg values (ÎŽ26Mg = −0.19 ± 0.07‰, 2SD, n = 7) than weathering-dominated ones (ÎŽ26Mg = −0.10 ± 0.12‰, 2SD, n = 25). Calculated Mg isotopic compositions of fresh mantle peridotites vary from −0.29 to −0.13‰, beyond the previously reported range of the subcontinental lithospheric mantle (−0.25 ± 0.04‰) and the analytical uncertainty (±0.07‰, 2SD). Our study therefore indicates that the oceanic mantle may have similar but slightly heterogeneous Mg isotopic compositions to that of subcontinental lithospheric mantle. Secondary serpentinization does not fractionate Mg isotopes of abyssal peridotites, whereas low-T weathering and formation of clay can result in the enrichment of heavy Mg isotopes in abyssal peridotites. This study also demonstrates that fluid-rock interaction does not necessarily produce rocks with intermediate Mg isotopic compositions. Magnesium isotopes of the rocks thereafter are dependent on the secondary minerals formed. We also conclude that the release of light Mg isotopes into the ocean during alteration of abyssal peridotites can be an important influx of Mg for the seawater Mg budget. Abyssal peridotites with a heavy Mg isotopic signature can be recycled into the mantle in subduction zones and may thus result in heterogeneous Mg isotopic compositions of the oceanic mantle and heavy Mg isotopic compositions of arc magmas.This study was supported by grants from the National Science Foundation of China (grants 41473038 and 41503010), China Postdoctoral Science Foundation (2015M570145), National Science Foundation (EAR-1056713 and EAR-1340160) and project MOST104 -2745-M-002-001-ASP granted to SLC. Partial support for HJBD was provided by the US National Science Foundation (OCE-1434452)

    The modulation of hypoxia-inducible factor-1α/plasminogen activator inhibitor-1 axis in human gingival fibroblasts stimulated with cyclosporine A

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    Background/PurposeThe prominent side effect of the immunosuppressive drug cyclosporine A (CsA) is gingival overgrowth. Hypoxia-inducible factor (HIF)-1α regulates a wide variety of profibrogenic genes, which are closely associated with tissue fibrosis. The aim of this study was to compare HIF-1α expression in normal gingival tissues and CsA-induced gingival overgrowth specimens and further explore the potential mechanisms that may lead to induction of HIF-1α expression.MethodsFifteen CsA-induced gingival overgrowth specimens and five normal gingival tissues were examined by immunohistochemistry. Western blot was used to investigate the effects of CsA on the expression of HIF-1α in cultured human gingival fibroblasts. The effects of CsA on plasminogen activator inhibitor (PAI)-1 expression were evaluated in environmental hypoxia.ResultsHIF-1α staining in gingival tissue was stronger in CsA-induced gingival overgrowth group than normal gingival group (p < 0.05). The expression of HIF-1α was significantly higher in CsA-induced gingival overgrowth specimens with higher levels of inflammatory infiltrates (p = 0.041). CsA was found to upregulate HIF-1α protein in a dose-dependent manner (p < 0.05). Hypoxia increased CsA-induced PAI-1 protein expression than normoxic conditions (p < 0.05).ConclusionThese results suggest that HIF-1α expression is significantly upregulated in CsA-induced gingival overgrowth specimens. The activation of HIF-1α may promote fibrogenesis by an increase of PAI-1 expression and a subsequent elevation of extracellular matrix production in gingival tissues

    Magnetically Directed Targeting Aggregation of Radiolabelled Ferrite Nanoparticles

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    Ferrite magnetic nanoparticles (Fe3O4 or iron (II,III) oxide; 15–25 nm of diameter) were developed. These magnetic nanoparticles are a potential vehicle for magnetically induced target aggregation in living animals. In this preliminary study, the radiochemical purity for the radiolabeled magnetic nanoparticles was examined, and the possibility of the magnetically induced targeting of the radio-nanoparticles was evaluated. Our results showed that radiolabeled ferrite nanoparticles can be used as magnetic targeting agents with high labeling efficiency and stability. These particles can be distributed within living animals via intravenous injection, and the biodistribution of the particles can be potentially controlled by external magnetism. These evaluations will be the groundwork for the future development of delivery techniques for radiopharmaceuticals through external magnetic control

    Enhanced Antifungal Bioactivity of Coptis Rhizome Prepared by Ultrafining Technology

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    The aim of this study was to identify and quantify the bioactive constituents in the methanol extracts of Coptis Rhizome prepared by ultrafining technology. The indicator compound was identified by spectroscopic method and its purity was determined by HPLC. Moreover, the crude extracts and indicator compound were examined for their ability to inhibit the growth of Rhizoctonia solani KĂŒhn AG-4 on potato dextrose agar plates. The indicator compound is a potential candidate as a new plant derived pesticide to control Rhizoctonia damping-off in vegetable seedlings. In addition, the extracts of Coptis Rhizome prepared by ultrafining technology displayed higher contents of indicator compound; they not only improve their bioactivity but also reduce the amount of the pharmaceuticals required and, thereby, decrease the environmental degradation associated with the harvesting of the raw products

    Elevated plasma level of visfatin/pre-b cell colony-enhancing factor in male oral squamous cell carcinoma patients

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    Objectives: Visfatin, also known as nicotiamide phosphoribosyltransferase or pre-B cell colony enhancing factor, is a pro-inflammatory cytokine whose serum level is increased in various cancers. In this study, we investigated whether plasma visfatin levels were altered in patients with oral squamous cell carcinoma (OSCC). The relation ship between plasma visfatin levels and the pretreatment hematologic profile was also explored. Study Design: Plasma visfatin concentrations were measured through ELISA in OSCC patients and control sub- D esign: Plasma visfatin concentrations were measured through ELISA in OSCC patients and control sub- esign: Plasma visfatin concentrations were measured through ELISA in OSCC patients and control sub jects. A total of 51 patients with OSCC and 57 age- and body mass index (BMI)-matched control subjects were studied. All study subjects were male. Results: Plasma visfatin was found to be elevated in patients with OSCC (7.0 ± 4.5 vs. 4.8 ± 1.9 ng/ml, p = 0.002). Multiple logistic regression analysis revealed visfatin as an independent association factor for OSCC, even after full adjustment of known biomarkers. Visfatin level was significantly correlated with white blood cell (WBC) count, neutrophil count, and hematocrit (all p < 0.05). In addition, WBC count, neutrophil count, and visfatin gradually increased with stage progression, and hematocrit gradually decreased with stage progression (all p < 0.05). Conclusion: Increased plasma visfatin levels were associated with OSCC, independent of risk factors, and were cor related with inflammatory biomarkers. These data suggest that visfatin may act through inflammatory reactions to play an important role in the pathogenesis of OSC

    Psychometric properties of the Little Developmental Coordination Disorder Questionnaire-Taiwan

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    Importance: Early identification of young children at risk of developmental coordination disorder (DCD) can support early intervention and prevent secondary sequelae. Objective: This study examined the psychometric properties of the translated and cross-culturally adapted Little Developmental Coordination Disorder Questionnaire-Taiwan (LDCDQ-TW). Design: Prospective study. Setting: Parent respondents, recruited via kindergarten settings. Participants: 1124 parents of typically developing children ages 36-71 months. Children with confirmed developmental diagnoses were excluded. Outcomes and Measures: The LDCDQ-TW, a 15-item parent questionnaire for identifying children at risk for DCD, and the Movement Assessment Battery for Children (2nd edition) (MABC-2). Results: Findings revealed excellent test-retest reliability (ICC=0.97) and fair inter-rater reliability (ICC=0.47). Using MABC-2 scores, the non-DCD group (> 15th percentile) scored significantly higher than the DCD and suspect-DCD groups on the LDCDQ-TW, but the latter two groups did not differ. Using the 15th percentile of both the MABC-2 and the LDCDQ-TW, sensitivity was 0.96 and specificity 0.68. Conclusions and Relevance: While standardized performance-based assessments are required to confirm a DCD diagnosis (typically after the age of 5), the LDCDQ-TW demonstrated sound reliability and validity and can support the early identification of young children at risk of DCD in Taiwan. What This Article Adds: The LDCDQ-TW questionnaire has sound psychometric properties and can be used to support early identification and monitoring of young children at risk of DC

    Anti-Fatigue Effect of Aqueous Extract of Anisomeles indica (L) Kuntze in Mice

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    Purpose: To determine the anti-fatigue effect of Anisomeles indica (L.) Kuntze, an herb traditionally used for health improvement in Taiwan.Methods: Three groups (n = 10 per group) of Balb/c female mice were administered A. indica aqueous extract orally for 28 days at 125 (low dose A. indica, LA), 250 (medium dose A. indica, MA), and 500 (high dose A. indica, HA) mg/kg/day, respectively, while a control group received distilled water. After 28 days, a forced swimming test was performed, and biochemical parameters including plasma triglyceride (TG), glucose, lactate and ammonia levels related to fatigue were examined.Results: No mice died during the study period. Physical examinations did not reveal any treatmentrelated adverse effects after dosing, in terms of food and water consumption. Moreover, no obvious peptic ulcers, haemorrhage, or pathological changes in the liver or kidney were observed in A. indica treated mice, and there were no significant differences in body weight between the control and treatment groups (p &gt; 0.05). Mice treated with A. indica extract in the MA and HA groups showed significantly prolonged exhaustive swimming time (p &lt; 0.05), increased hepatic glycogen and muscle glycogen levels (p &lt; 0.05), and decreased triglyceride and plasma ammonia levels (p &lt; 0.05) in a dosedependent manner, compared with the controls. However, plasma glucose and lactic acid levels were not significantly changed (p &gt; 0.05).Conclusion: These results provide the first in vivo evidence supporting the anti-fatigue claims associated with A. indica treatment, indicating that this traditional herb may be of therapeutic use as an ergogenic and anti-fatigue agent.Keywords: Anisomeles indica, Exhaustive swimming test, Fatigue, Glycogen, Plasma ammonia, Lactic aci

    EBV-encoded small RNA1 and nonresolving inflammation in rheumatoid arthritis

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    AbstractRheumatoid arthritis (RA) is a chronic autoimmune disease characterized by perpetuated inflammation in multiple joints. To date, there is no cure for RA, and the causal factor for non-resolving inflammation in RA remains unclear. In this study, we initially observed expression of Epstein–Barr virus-encoded small RNA1 (EBER1) in the synovial tissue of all five patients who showed nonresolving RA inflammation. By contrast, EBER1 was detected in the synovial tissue of only one out of seven patients with advanced osteoarthritis (OA; p < 0.01, Fisher’s exact test). To confirm this finding, we conducted a second study on synovial tissue samples taken from 23 patients with nonresolving RA inflammation and 13 patients with OA. All synovial samples from patients with nonresolving inflammation of RA showed positive expression of EBER1 (23/23, 100%), whereas none of the synovial samples from patients with OA showed expression of EBER1 (0/13, 0%; p < 0.001, by Fisher’s exact test). In vitro, transfection of RA synovial fibroblasts with EBER1 induced the production of interleukin-6. Taken together, these data strongly suggest that nonresolving RA inflammation is strongly related to the presence of EBER1, which might be, at least partially, responsible for synovial fibroblast interleukin-6 production

    Is acupuncture effective in controlling gagging when taking an alginate impressions?

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    Our community health project aimed to (1) identify the prevalence of gagging among patients attending the Prince Philip Dental Hospital; and to identify socio-demographic variations in reported gagging experiences; and (2) perform a pilot study to evaluate the effectiveness of acupuncture in the control of gagging in the dental setting. Methods: A survey on reported gagging experiences was conducted among patients attending our hospital involving a convenience sample of 225 patients. Participants who reported to previously gag in the dental setting were invited to participate in a pilot study to evaluate the effectiveness of acupuncture in controlling gagging when taking an upper alginate impression. Participants were randomized to receive acupuncture stimulation at a site reported to be effective in the control of gagging on the lower lip (point CV 24) or at a sham site on the upper lip (point GV 26) on their first visit and at their second visit to receive the alternative acupuncture stimulation. Results: The response rate to the survey was 81.3% (183/225). Approximately a third (58/183) reported to have experienced gagging in the dental setting and most frequently encountered this when having a dental impression (among approximately a quarter of participants - 44/183). Half (95/183) reported gagging while performing oral self-care. Four in ten participants (73/183) reported some stress visiting the dentist related to gagging. Sociodemographic variations in reported gagging experiences were evident with respect to age, gender and education level. The response rate to the pilot study was 92.3% (36/39). There was no significant difference in the prevalence of gagging when acupuncture was applied to the test site compared to when acupuncture was applied to the sham site on dental examination (p>0.05) or when taking an upper alginate impression (p>0.05). Conclusions: Gagging in a relative common experience reported by patients attending our hospital – in daily life, in the dental setting and in performing oral self-care. Socio-demographic variations in the prevalence of gagging were apparent. The pilot study does not support the use of acupuncture in controlling gagging in the dental setting.published_or_final_versio
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