576 research outputs found

    Investigation of the constancy of the MWCNTs on the fibres surface for manufactured self-sensing composites

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    This the author accepted manuscript. The fial version is available from Elsevier via the DOI in this recordDifferent methods have been used to deposit the multi-walled carbon nanotubes (MWCNTs) onto the fibre surface to fabricate self-sensing composites. However, the constancy of the MWCNTs onto the fibre surfaces during infusion processing still unclear. In this study, we have deposited MWCNTs onto the glass fibre surface by two methods to investigate the state of MWCNTs during and after epoxy infusion processing. In the first method, the glass fibres were directly coated with the MWCNTs and in the second method, an adhesive was applied to coat the glass fibre surface before depositing the MWCNTs over it. Rectangular specimens for both types of self-sensing composites were cut from different specified zones and then tested. The results showed that the self-sensing composites with adhesively bonded MWCNTs exhibited more consistent in their properties than the composites where no adhesive was used. In addition, the electrical resistance of both types of self-sensing composites was monitored during the epoxy infusion process. The results showed that the electrical resistance was not obviously affected for composite with non-adhesive bonded MWCNTs and was high for the specimens where the MWCNTs were not adhesively bonded. Moreover, the numerical study was also conducted and the results indicated that the relationship between the volume fraction of the MWCNTs and their tunnelling distance was an inverse. The current study proves evidence that the properties of the self-sensing composites are strongly dependent on the method that used to deposit the MWCNTs on the surface of glass fibres layers.Iraqi Ministry of Oi

    Cytotoxic chemotherapy: Still the mainstay of clinical practice for all subtypes metastatic breast cancer

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    Cytotoxic chemotherapy remains central to the treatment of all subtypes of metastatic breast cancer (MBC). We review evidence-based chemotherapy options for women with MBC after an anthracycline and a taxane including re-challenge with anthracycline or taxane, capecitabine, eribulin and ixabepilone as a single agent or combination with capecitabine (not approved in the EU); and the vinca alkaloid vinflunine as single agent or combined with either capecitabine/gemcitabine (also not approved EU or USA). Etirinotecan pegol, comprising irinotecan bound to polyethylene glycol by a biodegradable linker, is a new cytotoxic agent for patients with MBC that has achieved encouraging response rates in phase II studies; it has been further evaluated in the phase III BEACON trial. New cytotoxics should address novel targets or modes of delivery, achieve meaningful improvements in outcomes and seek to identify predictive biomarker(s)

    Burning mouth syndrome (BMS) : evaluation of thyroid and taste

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    Background Burning mouth syndrome (BMS) is a chronic, intraoral burning sensation seen mainly in middle-aged and post-menopausal females, without identifiable oral lesions or abnormal laboratory findings, but often associated with psychogenic disorders such as depression. The latter can have a range of causes, including hormonal. Objective Since there may be connections between BMS, psychogenic changes, hormonal changes and taste abnormalities , we have examined aspects of taste and thyroid function.. Patients and methods We selected 50 patients with BMS (study group) and 50 healthy subjects (control group) and analysed their ability to taste bitter, acid and spicy substances and analysed their thyroid function and Undertook thyroid echography. Results Taste sensation was normal in all controls. However, 30 of the patients with BMS reported ageusia for bitter taste and 2 had ageusia for acid. The use of pepper sauce ( Tabasco®) (spicy substance) produced a strong burning to the tongue in 28 patients of the BMS group but only in 10 controls. No control patients showed abnormality of thyroid function or echograpic abnormality. Five patients in the BMS group had biochemical evidence of hypothyroidism, 4 patients had raised levels of thyroid autoantibodies and, of the 41 remaining BMS patients, most (34) had thyroid echographic changes indicative of nodularity. Conclusions Hypothyroidism may be responsible for a negative influence on taste and consequent increase in trigeminal sensorial sensation (tactile, thermal and painful sensation)

    An EXAFS study of RuSr2GdCu2O8: evidence of magnetoelastic coupling

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    The EXAFS spectrum of two samples of RuSr2GdCu2O8 prepared by means of slightly different procedures was measured in the temperature range from 10 up to 300 K on the K-edge of Cu. Both the basal and the apical Cu–O distances are not influenced by the magnetic and the superconducting transitions. Moreover the temperature dependence of the Debye–Waller factors of the R(Cu–Obasal) distance for both samples is in agreement with the Debye model for thermal disorder. On the contrary, r2(Cu–Oapical) shows a clear peak around the magnetic transition. This effect is attributed to magnetoelastic couplin

    Arabidopsis mutants reveal that short- and long-term thermotolerance have different requirements for trienoic fatty acids

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    The photosynthetic thylakoid has the highest level of lipid unsaturation of any membrane. In Arabidopsis thaliana plants grown at 22°C, approximately 70% of the thylakoid fatty acids are trienoic – they have three double bonds. In Arabidopsis, and other species, the levels of trienoic fatty acids decline substantially at higher temperatures. Several genetic studies indicate that reduced unsaturation improves photosynthetic function and plant survival at high temperatures. Here, these studies are extended using the Arabidopsis triple mutant, fad3-2 fad7-2 fad8 that contains no detectable trienoic fatty acids. In the short-term, fluorescence analyses and electron-transport assays indicated that photosynthetic functions in this mutant are more thermotolerant than the wild type. However, long-term photosynthesis, growth, and survival of plants were all compromised in the triple mutant at high temperature. The fad3-2 fad7-2 fad8 mutant is deficient in jasmonate synthesis and this hormone has been shown to mediate some aspects of thermotolerance; however, additional experiments demonstrated that a lack of jasmonate was not a major factor in the death of triple-mutant plants at high temperature. The results indicate that long-term thermotolerance requires a basal level of trienoic fatty acids. Thus, the success of genetic and molecular approaches to increase thermotolerance by reducing membrane unsaturation will be limited by countervailing effects that compromise essential plant functions at elevated temperatures
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