1,049 research outputs found

    A superoxide dismutase biosensor for measuring the antioxidant capacity of blueberry based integrators

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    The antioxidant capacity of capsules containing blueberry based products which are included among the group of integrators owing to their antioxidant capacity and produced by various films was investigated. The results of the investigation are compared to rank these products in order to their antioxidant capacity. In order to measure antioxidant capacity, our laboratory has recently developed a special electrochemical method based on a superoxide dismutase (SOD) biosensor to determine the superoxide radical. The results obtained by applying the SOD biosensor method to various blueberry based integrators were compared with the results obtained with the spectrophotometric (FRAP) method based on N,N-dimethyl-p-phenylendiamine (DMPD-FeCl3) and with those obtained also using the ORAC fluorimetric (TRAP) method. One of the more interesting aspect of the article is the good agreement it evidences of the results of the three methods for measuring antioxidant capacity. The three methods differ among themselves: an Electron Transfer (ET) method, a Hydrogen Atom Trasnfer Metod (HAT) and an electrochemical based biosensor method of the Morning Superoxide Radical (MSR) type. It is also shown how the antioxidant capacity of the fresh vegetable is in any case always greater then of any food supplement obtained from the same type of vegetable

    Topotactic and reconstructive changes at high pressures and temperatures from Cs-natrolite to Cs-hexacelsian

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    Synchrotron X-ray powder diffraction experiments have been performed on dehydrated Csexchanged natrolite to systematically investigate successive transitions under high pressures and temperatures. At pressures above 0.5(1) GPa using H2O as a pressure-transmitting medium and after heating to 100 \ub0C, dehydrated Cs16Al16Si24O80 (deh-Cs-NAT) transforms to a hydrated phase Cs16Al16Si24O80\ub716H2O (Cs-NAT-II), which has a ca. 13.9% larger unit-cell volume. Further compression and heating to 1.5 GPa and 145 \ub0C results in the transformation of Cs-NAT-II to Cs16Al16Si32O96 (anh-Cs-POL), a H2O-free pollucite-like triclinic phase with a 15.6% smaller unit-cell volume per 80 framework oxygen atoms (80Of). At pressures and temperatures of 3.7 GPa and 180 \ub0C, a new phase Cs1.547Al1.548Si6.452O16 (Cs-HEX) with a hexacelsian framework forms, which has a ca. 1.8% smaller unit-cell volume per 80Of. This phase can be recovered after pressure release. The structure of the recovered Cs-HEX has been refined in space group P63/mcm with a = 5.3731(2) \uc5 and c = 16.6834(8) \uc5, and also been confirmed by HAADF-STEM real space imaging. Similar to the hexacelsian feldspar (i.e., BaAl2Si2O8), Cs-HEX contains Cs+ cations that act as bridges between the upper and lower layers composed of tetrahedra and are hexa-coordinated to the upper and lower 6-membered ring windows. These pressure-and temperature-induced reactions from a zeolite to a feldspar-like material are important constraints for the design of materials for Cs+ immobilization in nuclear waste disposal

    Substantial variation in therapy for colorectal cancer across Europe: EUROCARE analysis of cancer registry data for 1987

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    To provide a quantitative description of the treatments applied to malignant colorectal cancer across Europe, we analysed all cases (11 333) of colorectal cancer registered in 1987 by 15 Cancer Registries in eight European countries. In a third of cancer registries, therapy was known for all cases, in the others 1-15% of registrations lacked treatment information. Eighty per cent of all patients received surgical resection, ranging from 58% (Estonia) to 92% (Tarn). The proportion of resections decreased with advancing age (85-73% for colon cancer; 85-70% for rectal cancer for 74 years, respectively). Only 4% of colon cancer patients received adjuvant or palliative chemotherapy, range 1-12%. Sixteen per cent of rectal cancer patients received radiotherapy with great inter-registry variability (1-43%). Since the proportion of surgically resected patients correlated positively with the 5-year relative survival probability reported by the recently published EUROCARE study, this may be part of the explanation for the major differences in survival for these cancers among different European populations. The most likely determinant of this correlation is stage at diagnosis, but, quality of, and access to surgery, as well as access to endoscopy, may differ among countries and registry areas, and these may also contribute to inter-country survival differences. Copyrigh

    Elastic behavior and pressure-induced structural modifications of the microporous Ca(VO)Si4O10·4H2O dimorphs cavansite and pentagonite

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    The behavior of natural microporous cavansite and pentagonite, orthorhombic dimorphs of Ca(VO) (Si4O10)x4H2O, was studied at high pressure by means of in situ synchrotron X-ray powder diffraction with a diamond anvil cell using two different pressure-transmitting fluids: methanol:ethanol: water = 16:3:1 (m.e.w.) and silicone oil (s.o.). In situ diffraction-data on a cavansite sample were collected up to 8.17(5) GPa in m.e.w, and up to 7.28(5) GPa in s.o. The high-pressure structure evolution was studied on the basis of structural refinements at 1.08(5), 3.27(5) and 6.45(5) GPa. The compressional behavior is strongly anisotropic. When the sample is compressed in s.o. from Pamb to 7.28(5) GPa, the volume contraction is 12.2%, whereas a, b and c decrease by 1.6%, 10.3% and 0.3%, respectively. The main deformation mechanisms at high-pressure are basically driven by variation of the T\u2013O\u2013T angles. Powder diffraction data on a pentagonite sample were collected up to 8.26(5) GPa in m.e.w and 8.35(5) GPa in s.o. Additional single-crystal X-ray diffraction experiments were performed in m.e.w. up to 2.04(5) GPa. In both cases, pressure-induced over-hydration was observed in m.e.w. at high pressure. The penetration of a new H2O molecule leads to a stiffening effect of the whole structure. Moreover, between 2.45(5) and 2.96(5) GPa in m.e.w., a phase transition from an orthorhombic to a triclinic phase was observed. In s.o. pentagonite also transformed to a triclinic phase above 1.71(5) GPa. The overall compressibility of pentagonite and cavansite in s.o. is comparable, with a volume contraction of 11.6% and 12.2%, respectively

    Manganese incorporation in synthetic hercynite

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    Manganese incorporation in synthetic hercynite, and partitioning between hercynite and silicate melt synthesized at 1.0 GPa, 1250\ub0C, and at an f O2 buffered by Fe-FeO, has been studied by X-ray absorption spectroscopy and single-crystal X-ray structure refinement. Spectra indicate the presence of both Mn2+ and Mn3+ (and possibly also Mn4+) in synthetic hercynite and partitioning of Mn2+ into the melt phase, and Mn3+ into hercynite, respectively, under run conditions. X-ray refinement is consistent with partial disorder of Fe and Al across tetrahedral and octahedral sites. A higher than expected degree of Fe-Al disorder in the Mn-bearing hercynite can be explained by preferential incorporation of Mn2+ onto the tetrahedral site, and indicates that Fe-Al disorder in pure, stoichiometric hercynite cannot necessarily be used to determine closure temperatures in natural spinel. However, partitioning of Mn2+ and Mn3+ between melt and hercynite suggests that Mn incorporation in hercynite could be used as a measure of f O2 conditions in magmas during spinel crystallization

    High-pressure behavior and phase stability of Na2B4O6(OH)2·3H2O (kernite)

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    The high-pressure behavior of kernite [ideally Na2B4O6(OH)2\ub73H2O, a ~ 7.02 \u212b, b ~ 9.16 \u212b, c ~ 15.68 \u212b, \u3b2 = 108.9\ub0, Sp Gr P21/c, at ambient conditions], an important B-bearing raw material (with B2O3 48 51 wt%) and a potential B-rich aggregate in radiation shielding materials, has been studied by single-crystal synchrotron X-ray diffraction up to 14.6 GPa. Kernite undergoes an iso-symmetric phase transition at 1.6-2.0 GPa (to kernite-II). Between 6.6-7.5 GPa, kernite undergoes a second phase transition, possibly iso-symmetric in character (to kernite-III). The crystal structure of kernite-II was solved and refined. The isothermal bulk modulus (KV0 = \u3b2-1 P0,T0, where \u3b2P0,T0 is the volume compressibility coefficient) of the ambient-pressure polymorph of kernite was found to be KV0 = 29(1) GPa and a marked anisotropic compressional pattern, with K(a)0: K(b)0: K(c)0~1:3:1.5., was observed. In kernite-II, the KV0 increases to 43.3(9) GPa and the anisotropic compressional pattern increases pronouncedly. The mechanisms, at the atomic scale, which govern the structure deformation, have been described

    Immunotherapeutic efficacy of retargeted ohsvs designed for propagation in an ad hoc cell line

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    Our laboratory has pursued the generation of cancer‐specific oncolytic herpes simplex viruses (oHSVs) which ensure high efficacy while maintaining a high safety profile. Their blueprint included retargeting to a Tumor‐Associated Antigen, e.g., HER2, coupled to detargeting from natural receptors to avoid off‐target and off‐tumor infections and preservation of the full complement of unmodified viral genes. These oHSVs are “fully virulent in their target cancer cells”. The 3rd generation retargeted oHSVs carry two distinct retargeting moieties, which enable infection of a producer cell line and of the target cancer cells, respectively. They can be propagated in an ad hoc Vero cell derivative at about tenfold higher yields than 1st generation recombinants, and more effectively replicate in human cancer cell lines. The R‐335 and R‐337 prototypes were armed with murine IL‐12. Intratumorally‐administered R‐337 conferred almost complete protection from LLC‐ 1‐HER2 primary tumors, unleashed the tumor microenvironment immunosuppression, synergized with the checkpoint blockade and conferred long‐term vaccination against distant challenge tumors. In summary, the problem intrinsic to the propagation of retargeted oHSVs—which strictly require cells positive for targeted receptors—was solved in 3rd generation viruses. They are effective as immunotherapeutic agents against primary tumors and as antigen‐agnostic vaccines

    Development of a stochastic computational fluid dynamics approach for offshore wind farms

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    In this paper, a method for stochastic analysis of an offshore wind farm using computational fluid dynamics (CFD) is proposed. An existing offshore wind farm is modelled using a steady-state CFD solver at several deterministic input ranges and an approximation model is trained on the CFD results. The approximation model is then used in a Monte-Carlo analysis to build joint probability distributions for values of interest within the wind farm. The results are compared with real measurements obtained from the existing wind farm to quantify the accuracy of the predictions. It is shown that this method works well for the relatively simple problem considered in this study and has potential to be used in more complex situations where an existing analytical method is either insufficient or unable to make a good prediction
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