661 research outputs found

    Assessment of Identity Disturbance: Factor Structure and Validation of the Personality Structure Questionnaire in an Italian Sample

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    here are few brief measures of identity disturbance for use in clinical practice that have been subject to any cross - culturally validation . This study investigated the construct validity of the Personality Structure Questionnaire (PSQ) in Italian clinical (N=237) and community ( N=296) samples . Confirmatory factor analysis was conducted to investigate the internal structure of the PSQ. A three – factor structure (i.e., differing self - states, mood variability and behavioral loss of control) including a second - order factor provided the best fit to the data . This structure was demonstrated to be invariant across sex and clinical diagnosis , with clinical diagnosis significantly predicting increased PSQ scores . A g lobal PSQ score of between 26 - 28 was found to be an appropriate cut-off for assisting in diagnostic processes. Implications for the assessment and treatment of psychological disorders with a marked identity disturbance component are discussed

    Ambulatory surgery for perianal Crohn’s disease. Study of feasibility

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    Background. One-third of Crohn’s disease (CD) patients present perianal fistula. The gold standard in the diagnosis and treatment of symptomatic perianal disease (PAD) in CD is the exploration of the anal canal and distal rectum under anesthesia (EUA). This procedure is mainly conducted as a day case surgery. Unfortunately, it is not always possible to proceed within the ideal timing and any delay may well represent a relevant clinical issue. The aim of this study was to evaluate the feasibility of outpatient treatment of symptomatic perianal fistulas in CD patients. Methods. All CD patients under regular follow-up at our inflammatory bowel disease referral center, presenting with symptomatic perianal fistulas, were offered surgical consultation. The data of patients were prospectively collected for three years (February 2014 to February 2017) for the purpose of the study. All clinical information, including previous EUA and/or records from MRI and endoscopic ultrasound, was included. Outpatient anal canal and distal rectum exploration and treatment (OE) were undertaken during the specialist surgical consultation. Fistulas were classified according to Parks’s classification; the type of outpatient treatment and compliance of patients were recorded. Pain was assessed by VAS at the time of the procedure and during the first control. Patients were followed up in the surgical clinic in relation to the study. Results. Ninety-two CD patients with symptomatic perianal fistulas had surgical consultation during the study period. OE was offered to all but 18 patients who fulfilled the exclusion criteria or had an extremely severe disease; six patients refused the OE (8.11%). Of the 68 patients undergoing OE, eleven (16.18%) had previous surgery for perianal disease. The OE was accomplished in sixty-one patients (89.71%), while in 7 patients, it was abandoned for scarce compliance. Nine patients (14.75%) underwent drainage of perianal abscess; in 3 of them, it was possible to probe the fistula tract, find the internal orifice, and pass a loose seton. Overall, setonage was performed in 50 patients (81.97%). Rectovaginal setons were placed in 3 patients and more than one seton (up to 3) in 6 cases. Fistulotomy was performed in 4 simple subcutaneous fistulous tracts. Concordance with the preoperative findings was found in 54 out of 61 patients. EUA was scheduled at the time of OE for the 7 patients who did not complete the procedure. All sixty-one patients who had the OE were followed up for a minimum of 12 months. Conclusions. This preliminary study indicates that OE in CD patients with symptomatic perianal fistulas is safe and feasible in a high-volume referral center. It might provide several benefits, including patients’ logistics, reduce or remove patients’ symptoms and discomfort, allow for a timely start of medical therapy, and avoid further complications

    Topoisomerase IB: a relaxing enzyme for stressed DNA

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    DNA topoisomerase I enzymes relieve the torsional strain in DNA; they are essential for fundamental molecular processes such as DNA replication, transcription, recombination, and chromosome condensation; and act by cleaving and then religating DNA strands. Over the past few decades, scientists have focused on the DNA topoisomerases biological functions and established a unique role of Type I DNA topoisomerases in regulating gene expression and DNA chromosome condensation. Moreover, the human enzyme is being investigated as a target for cancer chemotherapy. The active site tyrosine is responsible for initiating two transesterification reactions to cleave and then religate the DNA backbone, allowing the release of superhelical tension. The different steps of the catalytic mechanism are affected by various inhibitors; some of them prevent the interaction between the enzyme and the DNA while others act as poisons, leading to TopI-D NA lesions, breakage of DNA, and eventually cellular death. In this review, our goal is to provide an overview of mechanism of human topoisomerase IB action together with the different types of inhibitors and their effect on the enzyme functionality

    Magnetic properties of cobalt ferrite-silica nanocomposites prepared by a sol-gel autocombustion technique

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    The magnetic properties of cobalt ferrite-silica nanocomposites with different concentrations (15, 30, and 50 wt %) and sizes (7, 16, and 28 nm) of ferrite particles have been studied by static magnetization measurements and Mossbauer spectroscopy. The results indicate a superparamagnetic behavior of the nanoparticles, with weak interactions slightly increasing with the cobalt ferrite content and with the particle size. From high-field Mossbauer spectra at low temperatures, the cationic distribution and the degree of spin canting have been estimated and both parameters are only slightly dependent on the particle size. The magnetic anisotropy constant increases with decreasing particle size, but in contrast to many other systems, the cobalt ferrite nanoparticles are found to have an anisotropy constant that is smaller than the bulk value. This can be explained by the distribution of the cations. The weak dependence of spin canting degree on particle size indicates that the spin canting is not simply a surface phenomenon but also occurs in the interiors of the particles. (c) 2006 American Institute of Physics

    Magnetic properties of the frustrated AFM spinel ZnCr_2O_4 and the spin-glass Zn_{1-x}Cd_xCr_2O_4 (x=0.05,0.10)

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    The TT-dependence (2- 400 K) of the electron paramagnetic resonance (EPR), magnetic susceptibility, χ(T)\chi (T), and specific heat, Cv(T)C_{v}(T), of the normalnormal antiferromagnetic (AFM) spinel ZnCr2_{2}O4_{4} and the spin-glass (SG) Zn1x_{1-x}Cdx_{x}Cr2_{2}O4_{4} (x=0.05,0.10x=0.05,0.10) is reported. These systems behave as a strongly frustrated AFM and SG with % T_{N} TG12 \approx T_{G}\approx 12 K and -400 K ΘCW500\gtrsim \Theta_{CW}\gtrsim -500 K. At high-TT the EPR intensity follows the χ(T)\chi (T) and the gg-value is TT-independent. The linewidth broadens as the temperature is lowered, suggesting the existence of short range AFM correlations in the paramagnetic phase. For ZnCr2_{2}O4_{4} the EPR intensity and χ(T)\chi (T) decreases below 90 K and 50 K, respectively. These results are discussed in terms of nearest-neighbor Cr3+^{3+} (S =3/2=3/2%) spin-coupled pairs with an exchange coupling of J/k| J/k| \approx 50 K. The appearance of small resonance modes for T17T\lesssim 17 K, the observation of a sharp drop in χ(T)\chi (T) and a strong peak in Cv(T)C_{v}(T) at TN=12T_{N}=12 K confirms, as previously reported, the existence of long range AFM correlations in the low-TT phase. A comparison with recent neutron diffraction experiments that found a near dispersionless excitation at 4.5 meV for TTNT\lesssim T_{N} and a continuous gapless spectrum for TTNT\gtrsim T_{N}, is also given.Comment: 17 pages, 8 figures, 1 Table. Submitted to Physical Review

    . New ground-based lidar enables volcanic CO2 flux measurements

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    There have been substantial advances in the ability to monitor the activity of hazardous volcanoes in recent decades. However, obtaining early warning of eruptions remains challenging, because the patterns and consequences of volcanic unrests are both complex and nonlinear. Measuring volcanic gases has long been a key aspect of volcano monitoring since these mobile fluids should reach the surface long before the magma. There has been considerable progress in methods for remote and in-situ gas sensing, but measuring the flux of volcanic CO2—the most reliable gas precursor to an eruption—has remained a challenge. Here we report on the first direct quantitative measurements of the volcanic CO2 flux using a newly designed differential absorption lidar (DIAL), which were performed at the restless Campi Flegrei volcano. We show that DIAL makes it possible to remotely obtain volcanic CO2 flux time series with a high temporal resolution (tens of minutes) and accuracy (<30%). The ability of this lidar to remotely sense volcanic CO2 represents a major step forward in volcano monitoring, and will contribute improved volcanic CO2 flux inventories. Our results also demonstrate the unusually strong degassing behavior of Campi Flegrei fumaroles in the current ongoing state of unrest

    Particle size dependence of the magnetic properties of ultrafine granular films

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    Magnetic granular solids consist of ultrafine metal granules of nanometer sizes embedded in an insulating medium. The magnetic properties are dictated by the microstructure such as particle size, metal volume fraction, which are process controlled. We report the results of a series of granular Fe60(SiO2)40 films in which the particle size has been systematically varied. The magnetic coercivity, ranging from 500 to 2200 Oe, increases with particle size. The ferromagnetic-superparamagnetic transition had been studied by SQUID magnetometry and Mössbauer spectroscopy. The value of the magnetic anisotropy energy is found to be much larger than that due to magnetocrystalline anisotropy

    A small organic compound enhances the religation reaction of human topoisomerase I and identifies crucial elements for the religation mechanism

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    The different steps of the human Top1 (topoisomerase I) catalytic cycle have been analysed in the presence of a pentacyclic-diquinoid synthetic compound. The experiments indicate that it efficiently inhibits the cleavage step of the enzyme reaction, fitting well into the catalytic site. Surprisingly the compound, when incubated with the binary topoisomerase–DNA cleaved complex, helps the enzyme to remove itself from the cleaved DNA and close the DNA gap, increasing the religation rate. The compound also induces the religation of the stalled enzyme–CPT (camptothecin)– DNA ternary complex. Analysis of the molecule docked over the binary complex, together with its chemical properties, suggests that the religation enhancement is due to the presence on the compound of two oxygen atoms that act as hydrogen acceptors. This property facilitates the deprotonation of the 5 DNA end, suggesting that this is the limiting step in the topoisomerase religation mechanism

    In vitro and in silico characterization of an antimalarial compound with antitumor activity targeting human DNA topoisomerase IB

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    Human DNA topoisomerase IB controls the topological state of supercoiled DNA through a complex catalytic cycle that consists of cleavage and religation reactions, allowing the progression of fundamental DNA metabolism. The catalytic steps of human DNA topoisomerase IB were analyzed in the presence of a drug, obtained by the open-access drug bank Medicines for Malaria Venture. The experiments indicate that the compound strongly and irreversibly inhibits the cleavage step of the enzyme reaction and reduces the cell viability of three different cancer cell lines. Molecular docking and molecular dynamics simulations suggest that the drug binds to the human DNA topoisomerase IB-DNA complex sitting inside the catalytic site of the enzyme, providing a molecular explanation for the cleavage-inhibition effect. For all these reasons, the aforementioned drug could be a possible lead compound for the development of an efficient anti-tumor molecule targeting human DNA topoisomerase IB
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