475 research outputs found

    Comparing two intramedullary devices for treating trochanteric fractures: A prospective study

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    <p>Abstract</p> <p>Background</p> <p>Intertrochanteric fractures are surgically treated by using different methods and implants. The optional type of surgical stabilization is still under debate. However, between devices with the same philosophy, different design characteristics may substantially influence fracture healing. This is a prospective study comparing the complication and final functional outcome of two intramedullary devices, the intramedullary hip screw (IMHS) and the ENDOVIS nail.</p> <p>Materials and methods</p> <p>Two hundred fifteen patients were randomized on admission in two treatment groups. Epidemiology features and functional status was similar between two treatment groups. Fracture stability was assessed according to the Evan's classification. One hundred ten patients were treated with IMHS and 105 with ENDOVIS nail.</p> <p>Results</p> <p>There were no significant statistical differences between the two groups regarding blood loss, transfusion requirements and mortality rate. In contrast, the number of total complications was significantly higher in the ENDOVIS nail group. Moreover, the overall functional and walking competence was superior in the patients treated with the IMHS nail.</p> <p>Conclusions</p> <p>These results indicate that the choice of the proper implant plays probably an important role in the final outcome of surgical treatment of intertrochanteric fractures. IMHS nail allows for accurate surgical technique, for both static and dynamic compression and high rotational stability. IMHS nail proved more reliable in our study regarding nail insertion and overall uncomplicated outcome.</p

    Search for supersymmetric particles in scenarios with a gravitino LSP and stau NLSP

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    Sleptons, neutralinos and charginos were searched for in the context of scenarios where the lightest supersymmetric particle is the gravitino. It was assumed that the stau is the next-to-lightest supersymmetric particle. Data collected with the DELPHI detector at a centre-of-mass energy near 189 GeV were analysed combining the methods developed in previous searches at lower energies. No evidence for the production of these supersymmetric particles was found. Hence, limits were derived at 95% confidence level.Comment: 31 pages, 14 figure

    Linoleic Acid-Induced Ultra-Weak Photon Emission from Chlamydomonas reinhardtii as a Tool for Monitoring of Lipid Peroxidation in the Cell Membranes

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    Reactive oxygen species formed as a response to various abiotic and biotic stresses cause an oxidative damage of cellular component such are lipids, proteins and nucleic acids. Lipid peroxidation is considered as one of the major processes responsible for the oxidative damage of the polyunsaturated fatty acid in the cell membranes. Various methods such as a loss of polyunsaturated fatty acids, amount of the primary and the secondary products are used to monitor the level of lipid peroxidation. To investigate the use of ultra-weak photon emission as a non-invasive tool for monitoring of lipid peroxidation, the involvement of lipid peroxidation in ultra-weak photon emission was studied in the unicellular green alga Chlamydomonas reinhardtii. Lipid peroxidation initiated by addition of exogenous linoleic acid to the cells was monitored by ultra-weak photon emission measured with the employment of highly sensitive charged couple device camera and photomultiplier tube. It was found that the addition of linoleic acid to the cells significantly increased the ultra-weak photon emission that correlates with the accumulation of lipid peroxidation product as measured using thiobarbituric acid assay. Scavenging of hydroxyl radical by mannitol, inhibition of intrinsic lipoxygenase by catechol and removal of molecular oxygen considerably suppressed ultra-weak photon emission measured after the addition of linoleic acid. The photon emission dominated at the red region of the spectrum with emission maximum at 680 nm. These observations reveal that the oxidation of linoleic acid by hydroxyl radical and intrinsic lipoxygenase results in the ultra-weak photon emission. Electronically excited species such as excited triplet carbonyls are the likely candidates for the primary excited species formed during the lipid peroxidation, whereas chlorophylls are the final emitters of photons. We propose here that the ultra-weak photon emission can be used as a non-invasive tool for the detection of lipid peroxidation in the cell membranes

    Enantioselective Phytotoxicity of the Herbicide Imazethapyr on the Response of the Antioxidant System and Starch Metabolism in Arabidopsis thaliana

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    Background: The enantiomers of a chiral compound possess different biological activities, and one of the enantiomers usually shows a higher level of toxicity. Therefore, the exploration of the causative mechanism of enantioselective toxicity is regarded as one of primary goals of biological chemistry. Imazethapyr (IM) is an acetolactate synthase (ALS)-inhibiting chiral herbicide that has been widely used in recent years with racemate. We investigated the enantioselectivity between R- and S-IM to form reactive oxygen species (ROS) and to regulate antioxidant gene transcription and enzyme activity. Results: Dramatic differences between the enantiomers were observed: the enantiomer of R-IM powerfully induced ROS formation, yet drastically reduced antioxidant gene transcription and enzyme activity, which led to an oxidative stress. The mechanism by which IM affects carbohydrate metabolism in chloroplasts has long remained a mystery. Here we report evidence that enantioselectivity also exists in starch metabolism. The enantiomer of R-IM resulted in the accumulation of glucose, maltose and sucrose in the cytoplasm or the chloroplast and disturbed carbohydrates utilization. Conclusion: The study suggests that R-IM more strongly retarded plant growth than S-IM not only by acting on ALS, but also by causing an imbalance in the antioxidant system and the disturbance of carbohydrate metabolism wit

    Measurement of Trilinear Gauge Couplings in e+ee^+ e^- Collisions at 161 GeV and 172 GeV

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    Trilinear gauge boson couplings are measured using data taken by DELPHI at 161~GeV and 172~GeV. Values for WWVWWV couplings (V=Z,γV=Z, \gamma) are determined from a study of the reactions \eeWW\ and \eeWev, using differential distributions from the WWWW final state in which one WW decays hadronically and the other leptonically, and total cross-section data from other channels. Limits are also derived on neutral ZVγZV\gamma couplings from an analysis of the reaction \eegi

    Search for neutral heavy leptons produced in ZZ decays

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    Weak isosinglet Neutral Heavy Leptons (νm) have been searched for using data collected by the DELPHI detector corresponding to 3.3 × 106 hadronic Z0 decays at LEP1. Four separate searches have been performed, for short-lived νm production giving monojet or acollinear jet topologies, and for long-lived νm giving detectable secondary vertices or calorimeter clusters. No indication of the existence of these particles has been found, leading to an upper limit for the branching ratio BR(Z0 → νmν̄) of about 1.3 × 10-6 at 95% confidence level for νm masses between 3.5 and 50 GeV/c2. Outside this range the limit weakens rapidly with the νm mass. The results are also interpreted in terms of limits for the single production of excited neutrinos. © Springer-Verlag 1997

    Study of B0_s anti-B0_s oscillations and B0_s lifetimes using hadronic decays of B0_s mesons

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    Oscillations of B0s mesons have been studied in samples selected from about 3.5 million hadronic Z decays detected by DELPHI between 1992 and 1995. One analysis uses events in the exclusive decay channels: B0s -> Ds- pi+ or Ds- a1+ and B0s -> anti-D0 K- pi+ or anti-D0 K- a1+, where the D decays are completely reconstructed. In addition, B0s anti-B0s oscillations have been studied in events with an exclusively reconstructed Ds accompanied in the same hemisphere by a high momentum hadron of opposite charge. Combining the two analyses, a limit on the mass difference between the physical B0s states has been obtained: Delta(m_B0s) > 4.0 ps^{-1} at the 95% C.L. with a sensitivity of Delta(m_B0s) = 3.2 ps^{-1}. Using the latter sample of events, the B0s lifetime has been measured and an upper limit on the decay width difference between the two physical B0s states has been obtained: tau(B0s) = 1.53^{+0.16}_{-0.15}(stat.) +/- {0.07}(syst.) ps \Delta\Gamma(B0s)/\Gamma(B0s) < 0.69 at the 95% C.L. The combination of these results with those obtained using Ds+- lepton-+ sample gives: Delta(m_B0s) > 4.9 ps^{-1} at the 95% C.L. with a sensitivity of Delta(m_B0s) = 8.7 ps^{-1}. tau(B0s) = 1.46 +/- 0.11 ps and \Delta\Gamma(B0s)/\Gamma(B0s) < 0.45 at the 95% C.L.Comment: 42 pages, 13 figure

    The effect of dietary antioxidant supplementation in a vertebrate host on the infection dynamics and transmission of avian malaria to the vector.

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    Host susceptibility to parasites is likely to be influenced by intrinsic factors, such as host oxidative status determined by the balance between pro-oxidant production and antioxidant defences. As a result, host oxidative status acts as an environmental factor for parasites and may constrain parasite development. We evaluated the role of host oxidative status on infection dynamics of an avian malarial parasite by providing canaries (Serinus canaria) with an antioxidant supplementation composed of vitamin E (a lipophilic antioxidant) and olive oil, a source of monounsaturated fatty acids. Another group received a standard, non-supplemented food. Half of the birds in each group where then infected with the haemosporidian parasite, Plasmodium relictum. We monitored the parasitaemia, haematocrit level, and red cell membrane resistance, as well as the transmission success of the parasite to its mosquito vector, Culex pipiens. During the acute phase, the negative effect of the infection was more severe in the supplemented group, as shown by a lower haematocrit level. Parasitaemia was lower in the supplemented group during the chronic phase only. Mosquitoes fed on supplemented hosts were more often infected than mosquitoes fed on the control group. These results suggest that dietary antioxidant supplementation conferred protection against Plasmodium in the long term, at the expense of a short-term negative effect. Malaria parasites may take advantage of antioxidants, as shown by the increased transmission rate in the supplemented group. Overall, our results suggest an important role of oxidative status in infection outcome and parasite transmission

    Crosstalk between reactive oxygen species and pro-inflammatory markers in developing various chronic diseases: a review

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    The inflammation process in the human body plays a central role in the pathogenesis of many chronic diseases. In addition, reactive oxygen species (ROS) exert potentially a decisive role in human body, particularly in physiological and pathological process. The chronic inflammation state could generate several types of diseases such as cancer, atherosclerosis, diabetes mellitus and arthritis, especially if it is concomitant with high levels of pro-inflammatory markers and ROS. The respiratory burst of inflammatory cells during inflammation increases the production and accumulation of ROS. However, ROS regulate various types of kinases and transcription factors such nuclear factor-kappa B which is related to the activation of pro-inflammatory genes. The exact crosstalk between pro-inflammatory markers and ROS in terms of pathogenesis and development of serious diseases is still ambitious. Many studies have been attempting to determine the mechanistic mutual relationship between ROS and pro-inflammatory markers. Therefore hereby, we review the hypothetical relationship between ROS and pro-inflammatory markers in which they have been proposed to initiate cancer, atherosclerosis, diabetes mellitus and arthritis
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