Showing papers by "Sofia University published in 2006"

Bilbao Crystallographic Server. II. Representations of crystallographic point groups and space groups.

Abstract: The Bilbao Crystallographic Server is a web site with crystallographic programs and databases freely available on-line (http://www.cryst.ehu.es). The server gives access to general information related to crystallographic symmetry groups (generators, general and special positions, maximal subgroups, Brillouin zones etc.). Apart from the simple tools for retrieving the stored data, there are programs for the analysis of group–subgroup relations between space groups (subgroups and supergroups, Wyckoff-position splitting schemes etc.). There are also software packages studying specific problems of solid-state physics, structural chemistry and crystallography. This article reports on the programs treating representations of point and space groups. There are tools for the construction of irreducible representations, for the study of the correlations between representations of group–subgroup pairs of space groups and for the decompositions of Kronecker products of representations.

Observation of attraction between dark solitons.

Abstract: We demonstrate a dramatic change in the interaction forces between dark solitons in nonlocal nonlinear media. We present what we believe is the first experimental evidence of attraction of dark solitons. Our results indicate that attraction should be observable in other nonlocal systems, such as Bose-Einstein condensates with repulsive long-range interparticle interaction.

Distortion-dependent Raman spectra and mode mixing in R MnO 3 perovskites ( R = La , Pr , Nd , Sm , Eu , Gd , Tb , Dy , Ho , Y )

Abstract: The polarized Raman spectra of orthorhombic $R{\mathrm{MnO}}_{3}$ series $(R=\mathrm{La},\mathrm{Pr},\mathrm{Nd},\mathrm{Sm},\mathrm{Eu},\mathrm{Gd},\mathrm{Tb},\mathrm{Dy},\mathrm{Ho},\mathrm{Y})$ were studied at room temperature. The variation of phonon frequencies with $R$ ionic radius ${r}_{R}$ as a whole confirms the commonly accepted Raman line assignments with two noticeable exceptions: (1) with decreasing ${r}_{R}$ the stretching ${A}_{g}(1)$ and bending ${A}_{g}(3)$ modes strongly mix for $R=\mathrm{Sm}$ to Tb, while for further decrease or ${r}_{R}$ $(R=\mathrm{Dy},\mathrm{Ho},\mathrm{Y})$ the ${A}_{g}(3)$ mode is observed at higher frequency than ${A}_{g}(1)$ mode; (2) similar distortion-dependent mode mixing takes place for the rotational ${A}_{g}(2)$ and $\mathrm{O}1(x)$ $[{A}_{g}(7)]$ modes. The mode mixing is particularly strong for the $R{\mathrm{MnO}}_{3}$ compounds with ${r}_{R}$ values close to the transition from $A$ type to incommensurate sinusoidal antiferromagnetic ordering at low temperatures. The frequency of rotational ${A}_{g}(2)$ and ${A}_{g}(4)$ modes scales to the angles of ${\mathrm{MnO}}_{6}$ $[101]$ and $[010]$ rotations, respectively, and could be used as a measure of their value.

Ghrelin: a hormone regulating food intake and energy homeostasis.

Abstract: Regulation of energy homeostasis requires precise coordination between peripheral nutrient-sensing molecules and central regulatory networks. Ghrelin is a twenty-eight-amino acid orexigenic peptide acylated at the serine 3 position mainly with an n-octanoic acid, which is produced mainly in the stomach. It is the endogenous ligand of the growth hormone secretagogue (GHS) receptors. Since plasma ghrelin levels are strictly dependent on recent food intake, this hormone plays an essential role in appetite and meal initiation. In addition, ghrelin is involved in the regulation of energy homeostasis. The ghrelin gene is composed of four exons and three introns and renders a diversity of orexigenic peptides as well as des-acyl ghrelin and obestatin, which exhibit anorexigenic properties. Ghrelin stimulates the synthesis of neuropeptide Y (NPY) and agouti-related protein (AgRP) in the arcuate nucleus neurons of the hypothalamus and hindbrain, which in turn enhance food intake. Ghrelin-expressing neurons modulate the action of both orexigenic NPY/AgRP and anorexigenic pro-opiomelanocortin neurons. AMP-activated protein kinase is activated by ghrelin in the hypothalamus, which contributes to lower intracellular long-chain fatty acids, and this appears to be the molecular signal for the expression of NPY and AgRP. Recent data suggest that ghrelin has an important role in the regulation of leptin and insulin secretion and vice versa. The present paper updates the effects of ghrelin on the control of energy homeostasis and reviews the molecular mechanisms of ghrelin synthesis, as well as interaction with GHS receptors and signalling. Relationships with leptin and insulin in the regulation of energy homeostasis are addressed.

Antiphospholipid antibodies from patients with the antiphospholipid syndrome induce monocyte tissue factor expression through the simultaneous activation of NF‐κB/Rel proteins via the p38 mitogen‐activated protein kinase pathway, and of the MEK‐1/ERK pathway

Abstract: Objective Antiphospholipid syndrome (APS) is characterized by thrombosis and the presence of antiphospholipid antibodies (aPL). In patients with primary APS, expression of tissue factor (TF) on the surface of monocytes is increased, which may contribute to thrombosis in these patients. However, the intracellular mechanisms involved in aPL-mediated up-regulation of TF on monocytic cells are not understood. This study was undertaken to investigate the intracellular signals induced by aPL that mediate TF activation in monocytes from APS patients. Methods We analyzed, both in vivo and in vitro, aPL interactions with proteins that have signaling functions, including mitogen-activated protein kinases (MAP kinases) and NF-κB/Rel proteins. Results In vivo studies demonstrated significantly higher levels of both TF messenger RNA and TF protein in monocytes from APS patients compared with controls. At the molecular level, increased proteolysis of IκBα and activation of NF-κB were observed. Constitutive activation of both p38 and ERK-1 MAP kinases was also found. Treatment of normal monocytes with aPL activated ERK-1 and p38 MAP kinases, as well as the IκB/NF-κB pathway, in a dose-dependent manner. NF-κB activation and IκBα degradation induced by aPL were inhibited by the NF-κB inhibitor SN50 and the p38 MAP kinase inhibitor SB203580, thus suggesting crosstalk between these pathways. However, the MEK-1/ERK inhibitor PD98059 did not affect aPL-induced NF-κB binding activity. TF expression induced by aPL was significantly inhibited by combined treatment with the 3 inhibitors. Conclusion Our results suggest that aPL induces TF expression in monocytes from APS patients by activating, simultaneously and independently, the phosphorylation of MEK-1/ERK proteins, and the p38 MAP kinase–dependent nuclear translocation and activation of NF-κB/Rel proteins.

Spin-phonon coupling in orthorhombic R Mn O 3 ( R = Pr , Nd , Sm , Eu , Gd , Tb , Dy , Ho , Y ) : A Raman study

Abstract: The temperature-dependent Raman spectra of orthorhombic $R\mathrm{Mn}{\mathrm{O}}_{3}$ $(R=\mathrm{Pr},\mathrm{Nd},\mathrm{Sm},\mathrm{Eu},\mathrm{Gd},\mathrm{Tb},\mathrm{Dy},\mathrm{Ho},\mathrm{Y})$ were studied in the $5--300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ temperature range. It was established that while the materials with large ${R}^{3+}$ ionic radius ${r}_{R}$ and $A$-type antiferromagnetic order $(R=\mathrm{Pr},\mathrm{Nd},\mathrm{Sm})$ exhibit significant phonon softening and other anomalies with decreasing temperature near and below ${T}_{N}$, the effect of magnetic ordering is much weaker or negligible in compounds with $R=\mathrm{Eu}$, Gd, Tb, Dy, Ho, and Y, characterized by small ${r}_{R}$ and incommensurate magnetic structure. The results are discussed accounting for the variations with ${r}_{R}$ of the type of magnetic ordering and related spin-phonon interaction.

Elicitation of Plants

Abstract: Elicitors are compounds stimulating any type of plant defense. This broader definition of elicitors includes both substances of pathogen origin (exogenous elicitors and compounds released from plants by the action of the pathogen (endogenous elicitors). Also elicitors could be used as enhancers of plant-secondary-metabolite synthesis and could play an important role in biosynthetic pathways to enhanced production of commercially important compounds. The increased production, through elicitation, of the secondary metabolites from plant cell cultures has opened up a new area of research, which could have important economical benefits for bio industry.

Multilocular cystic renal cell carcinoma : a report of 45 cases of a kidney tumor of low malignant potential.

Abstract: The 2004 World Health Organization (WHO) classification of kidney tumors recognizes multilocular cystic renal cell carcinoma (MCRCC) as a rare variant of clear cell renal cell carcinoma with a good prognosis. Available information on its clinical significance is limited. The study cohort included 45 MCRCC cases classified according to 2004 WHO criteria obtained through a multi-institutional international search. Most patients had unilateral MCRCC with no side predominance that was found incidentally; 62% were men, but women had tumors at an earlier age (P = .385). MCRCC occurred slightly more often in men than in women (1.7:1). At diagnosis, 82% of patients had stage T1 and 16%, stage T2; 1 patient had stage T3. The Fuhrman grade was 1 (62%) or 2 (38%), with smaller tumors (

Interaction of C1q with IgG1, C-reactive protein and pentraxin 3: mutational studies using recombinant globular head modules of human C1q A, B, and C chains.

Abstract: C1q is the first subcomponent of the classical complement pathway that can interact with a range of biochemically and structurally diverse self and nonself ligands. The globular domain of C1q (gC1q), which is the ligand-recognition domain, is a heterotrimeric structure composed of the C-terminal regions of A (ghA), B (ghB), and C (ghC) chains. The expression and functional characterization of ghA, ghB, and ghC modules have revealed that each chain has specific and differential binding properties toward C1q ligands. It is largely considered that C1q-ligand interactions are ionic in nature; however, the complementary ligand-binding sites on C1q and the mechanisms of interactions are still unclear. To identify the residues on the gC1q domain that are likely to be involved in ligand recognition, we have generated a number of substitution mutants of ghA, ghB, and ghC modules and examined their interactions with three selected ligands: IgG1, C-reactive protein (CRP), and pentraxin 3 (PTX3). Our results suggest that charged residues belonging to the apex of the gC1q heterotrimer (with participation of all three chains) as well as the side of the ghB are crucial for C1q binding to these ligands, and their contribution to each interaction is different. It is likely that a set of charged residues from the gC1q surface participate via different ionic and hydrogen bonds with corresponding residues from the ligand, instead of forming separate binding sites. Thus, a recently proposed model suggesting the rotation of the gC1q domain upon ligand recognition may be extended to C1q interaction with CRP and PTX3 in addition to IgG1.

Latex-particle-stabilized emulsions of anti-Bancroft type.

Abstract: Here, we investigate water-in-oil (W/O) emulsions that are stabilized by polystyrene latex particles with sulfate surface groups. The particles, which play the role of emulsifier, are initially contained in the disperse (water) phase. The existence of such emulsions formally contradicts the empirical Bancroft rule. Theoretical considerations predict that the drop diameter has to be inversely proportional to the particle concentration, but should be independent of the volume fraction of water. In addition, there should be a second emulsification regime, in which the drop diameter is determined by the input mechanical energy during the homogenization. The existence of these two regimes has been experimentally confirmed, and the obtained data agree well with the theoretical model. Stable W/O emulsions have been produced with hexadecane and tetradecane, while, in the case of more viscous and polar oils (soybean and silicone oil), the particles enter into the oily phase, and Pickering emulsions cannot be obtained. The formation of stable emulsions demands the presence of a relatively high concentration of electrolyte that lowers the electrostatic barrier to particle adsorption at the oil -water interface. Because the attachment of particles at the drop surfaces represents a kind of coagulation, it turns out that the Schulze -Hardy rule for the critical concentration of coagulation is applicable also to emulsification, which has been confirmed with suspensions containing Na + ,M g 2+ , and Al 3+ counterions. The increase of the particle and electrolyte concentrations and the decrease of the volume fraction of water are other factors that facilitate emulsification in the investigated system. To quantify the combined action of these factors, an experimental stability -instability diagram has been obtained.

Surface photovoltage phase spectroscopy – a handy tool for characterisation of bulk semiconductors and nanostructures

Abstract: A new approach is proposed for determining the semiconductor conductivity type (n or p) based on measurements of surface photovoltage (SPV) phase spectra in metal–insulator–semiconductor structures under modulated super-bandgap optical excitation. It is shown that the sign of the bandgap-related knee in the spectrum of the SPV phase modulus gives information about the surface band bending direction and thus about the semiconductor type. The proposed approach can be applied also to multilayered structures, containing buried interfaces in order to obtain the band bending in the sample region, where the light is absorbed. Further on, the SPV phase spectral dependence is discussed taking into account the recombination processes in the system under study. It is concluded that for the cases of non-linear recombination the SPV phase spectrum reveals the peculiarities of the optical absorption coefficient spectrum, which is known until now only for the SPV amplitude spectrum. This is confirmed by SPV phase and amplitude spectral measurements in bulk Si, as well as in GaAs quantum wells.

Multispin giant magnons

Abstract: We investigate giant magnons from classical rotating strings in two different backgrounds. First we generalize the solution of Hofman and Maldacena and investigate new magnon excitations of a spin chain which are dual to a string on RxS{sup 5} with two nonvanishing angular momenta. Allowing string dynamics along the third angle in the five sphere, we find a dispersion relation that reproduces the Hofman and Maldacena one and the one found by Dorey for the two spin case. In the second part of the paper we generalize the two 'spin' giant magnon to the case of {beta}-deformed AdS{sub 5}xS{sup 5} background. We find agreement between the dispersion relation of the rotating string and the proposed dispersion relation of the magnon bound state on the spin chain.

Instability zones of periodic 1-dimensional Schrödinger and Dirac operators

Abstract: The spectra of Schrodinger and Dirac operators with periodic potentials on the real line have a band structure, that is, the intervals of continuous spectrum alternate with spectral gaps, or instability zones. The sizes of these zones decay, and the rate of decay depends on the smoothness of the potential. In the opposite direction, one can make conclusions about the smoothness of a potential based on the rate of decay of the instability zones. In the 1960s and 1970s this phenomenon was understood at the level of infinitely differentiable or analytic functions in the case of Schrodinger operators. However, only recently has the relationship between the smoothness of the potential and the rate of decay of the instability zones become completely understood and analyzed - for a broad range of classes of differentiable functions, - for Dirac operators and not just for Hill-Schrodinger operators, - in both the self-adjoint and non-self-adjoint cases. This paper is devoted to a survey of these results, mostly with complete proofs based on an approach developed by the authors.

Radical surgery-peritonectomy and intraoperative intraperitoneal chemotherapy for the treatment of peritoneal carcinomatosis in recurrent or primary ovarian cancer.

Abstract: Background and Objectives Advanced ovarian cancer typically spreads in a diffuse intra-abdominal fashion. This characteristic suggests that combined radical surgery and intraperitoneal chemotherapy may be a useful treatment procedure. The purpose of this study was to review patients submitted to surgical debulking and hyperthermic intraoperative intraperitoneal chemotherapy (HIIC) and to evaluate the potential prognostic survival factors for advanced epithelial ovarian cancer in our center. Methods A series of patients (N = 33) diagnosed of peritoneal carcinomatosis for epithelial ovarian cancer (stage III) from January 1997 to December 2004 submitted to radical surgery-peritonectomy and HIIC with paclitaxel was included in this study; 19 primary ovarian cancer and 14 recurrent ovarian cancer. Results Cytoreduction R0 (P = 0.018) and negative lymph nodes (P = 0.005) were covariables for major prognostic survival. Patients with optimal cytoreduction R0 obtained survival rates of 63% at 5 years in recurrent ovarian cancer and 60% in primary ovarian cancer, 71% and 63%, respectively with associated subtotal infra-abdominal peritonectomy, and even better results if negative lymph nodes. Conclusions Radical surgery-peritonectomy with HIIQ has been shown to be a surgical procedure with high tolerability, low morbimortality, enhanced survival, and prolonged disease-free interval in patients with peritoneal carcinomatosis so much for recurrent or primary ovarian cancer. J. Surg. Oncol. 2006;94:316–324. © 2006 Wiley-Liss, Inc.

Mesozoic–Tertiary structural evolution of an extensional gneiss dome—the Kesebir–Kardamos dome, eastern Rhodope (Bulgaria–Greece)

Abstract: The tectonic evolution of the Rhodope massif involves Mid-Cretaceous contractional deformation and protracted Oligocene and Miocene extension. We present structural, kinematic and strain data on the Kesebir–Kardamos dome in eastern Rhodope, which document early Tertiary extension. The dome consists of three superposed crustal units bounded by a low-angle NNE-dipping detachment on its northern flank in Bulgaria. The detachment separates footwall gneiss and migmatite in a lower unit from intermediate metamorphic and overlying upper sedimentary units in the hanging wall. The high-grade metamorphic rocks of the footwall have recorded isothermal decompression. Direct juxtaposition of the sedimentary unit onto footwall rocks is due to local extensional omission of the intermediate unit. Structural analysis and deformational/metamorphic relationships give evidence for several events. The earliest event corresponds to top-to-the SSE ductile shearing within the intermediate unit, interpreted as reflecting Mid-Late Cretaceous crustal thickening and nappe stacking. Late Cretaceous–Palaeocene/Eocene late-tectonic to post-tectonic granitoids that intruded into the intermediate unit between 70 and 53 Ma constrain at least pre-latest Late Cretaceous age for the crustal-stacking event. Subsequent extension-related deformation caused pervasive mylonitisation of the footwall, with top-to-the NNE ductile, then brittle shear. Ductile flow was dominated by non-coaxial deformation, indicated by quartz c-axis fabrics, but was nearly coaxial in the dome core. Latest events relate to brittle faulting that accommodated extension at shallow crustal levels on high-angle normal faults and additional movement along strike-slip faults. Radiometric and stratigraphic constraints bracket the ductile, then brittle, extensional events at the Kesebir–Kardamos dome between 55 and 35 Ma. Extension began in Paleocene–early Eocene time and displacement on the detachment led to unroofing of the intermediate unit, which supplied material for the syn-detachment deposits in supra-detachment basin. Subsequent cooling and exhumation of the footwall unit from beneath the detachment occurred between 42 and 37 Ma as indicated by mica cooling ages in footwall rocks, and extension proceeded at brittle levels with high-angle faulting constrained at 35 Ma by the age of hydrothermal adularia crystallized in open spaces created along the faults. This was followed by Late Eocene–Oligocene post-detachment overlap successions and volcanic activity. Crustal extension described herein is contemporaneous with the closure of the Vardar Ocean to the southwest. It has accommodated an earlier hinterland-directed unroofing of the Rhodope nappe complex, and may be pre-cursor of, and/or make a transition to the Aegean back-arc extension that further contributed to its exhumation during the Late Miocene. This study underlines the importance of crustal extension at the scale of the Rhodope massif, in particular, in the eastern Rhodope region, as it recognizes an early Tertiary extension that should be considered in future tectonic models of the Rhodope and north Aegean regions.

Contact Algebras and Region-based Theory of Space: Proximity Approach - II

Abstract: This paper is the second part of the paper [2]. Both of themare in the field of region-based (or Whitehedian) theory of space, which is an important subfield of Qualitative Spatial Reasoning (QSR). The paper can be considered also as an application of abstract algebra and topology to some problems arising and motivated in Theoretical Computer Science and QSR. In [2], different axiomatizations for region-based theory of space were given. The most general one was introduced under the name "Contact Algebra". In this paper some categories defined in the language of contact algebras are introduced. It is shown that they are equivalent to the category of all semiregular T$_0$-spaces and their continuous maps and to its full subcategories having as objects all regular (respectively, completely regular; compact; locally compact) Hausdorff spaces. An algorithm for a direct construction of all, up to homeomorphism, finite semiregular T$_0$-spaces of rank n is found. An example of an RCC model which has no regular Hausdorff representation space is presented. The main method of investigation in both parts is a lattice-theoretic generalization of methods and constructions from the theory of proximity spaces. Proximity models for various kinds of contact algebras are given here. In this way, the paper can be regarded as a full realization of the proximity approach to the region-based theory of space.

Neural Networks for Online Classification of Hand and Finger Movements Using Surface EMG signals

Abstract: Myoelectric signals (MES) are the electrical manifestation of muscular contractions and they can be used to create myoelectric prosthesis which are able to function with the amputee's muscle movements. This signal recorded at the surface of the skin of the forearm has been exploited to provide recognition of the movement of the hand and finger Movements of healthy subject. The objective of the paper is to describe the identification procedure, based on EMG patterns of forearm activity using various Neural Networks methods and to make a comparison between different intelligent computational methods of identification, which are used in this work. Then an online algorithm for movement identification and classification that utilises the trained Neural Networks is presented.

Selection of surfactants for stable paraffin-in-water dispersions, undergoing solid-liquid transition of the dispersed particles.

Abstract: A new experimental procedure is proposed for express evaluation of the coalescence stability of dispersions, in which the dispersed particles undergo solid-liquid phase transition. The procedure includes centrifugation of the dispersion concurrently with the phase transition of the particles and allows precise quantification of dispersion stability in terms of a critical pressure, at which the coalescence between the dispersed particles/drops takes place. The method is applied for studying the effects of surfactant type and concentration on the stability of paraffin-in-water dispersions, which have potential application in energy storage and transportation systems. Several types of water-soluble surfactants (anionic, nonionic, and polymeric) are compared, whereas hexadecane or tetradecane is used as a dispersed phase. Most of the studied individual surfactants are found to be inefficient stabilizers (except for the nonionic Tween 40 and Tween 60). However, the dispersion stability increases significantly after the addition of appropriate cosurfactants, such as hexadecanol, Brij 52, or cocoamidopropyl betaine. Surfactants and cosurfactants with longer hydrophobic tails are better stabilizers than those with shorter tails. The obtained results are discussed from the viewpoint of the mechanisms of particle/drop coalescence during the solid-liquid-phase transition. The consistency and the undercooling temperatures of the studied dispersions are also discussed, because these properties are important for their practical applications. The proposed procedure for evaluation of dispersion stability and some of the conclusions could be relevant to food emulsions, in which dispersed fat particles undergo solid-liquid-phase transition of similar type.

Exact Solutions of Regge-Wheeler Equation and Quasi-Normal Modes of Compact Objects

Abstract: The well-known Regge–Wheeler equation describes the axial perturbations of the Schwarzschild metric in the linear approximation. From a mathematical point of view it presents a particular case of the confluent Heun equation and can be solved exactly, due to recent mathematical developments. We present the basic properties of its general solution. A novel analytical approach and numerical techniques to study the boundary problems which correspond to quasi-normal modes of black holes and other simple models of compact objects are developed.

Photocatalytic properties of TiO2 modified with gold nanoparticles in the degradation of oxalic acid in aqueous solution

Abstract: The commercially available TiO 2 -catalyst (Degussa P25) was supported by spray pyrolysis deposition method on the outer surface of the quartz tubes, incorporated in photocatalytic reactor. The crystal structure and the morphology of the films were studied. The immobilized TiO 2 is modified with nanosized gold particles by the photoreduction method to obtain different noble metal loading (0.05–0.4 wt.%). The characterization of the synthesized catalysts was carried out by the BET method, X-ray photoelectron spectroscopy (XPS), SEM, TEM and the adsorption of the model pollutant was determined. The degradation of oxalic acid has been studied in aqueous solution photocatalyzed by band-gap-irradiated TiO 2 , modified with nanosized gold particles. The presence of low amounts of gold on the TiO 2 surface leads to an increase of its photocatalytic activity. The maximum value of the photocatalytic activity was registered with the ≈0.16 wt.% Au on TiO 2 sample. At this concentration the activity of the Au-modified TiO 2 is approximately double that of the semiconducting support. The adsorption properties of the catalysts, as well as the noble metal content on the surface of the support, influence the efficiency of the photocatalytic process. The reaction rate of photocatalytic degradation of the oxalic acid follows a zero kinetic order according to the Langmuir–Hinshelwood model.

Melatonin reduces apoptosis and necrosis induced by ischemia/reperfusion injury of the pancreas

Abstract: The pancreas is highly susceptible to the oxidative stress induced by ischemia/reperfusion (IR) injury leading to the generation of acute pancreatitis. Melatonin has been shown to be useful in the prevention of the damage by ischemia-reperfusion in liver, brain, myocardium, gut and kidney. The aim of the study was to evaluate the cytoprotective properties of melatonin against injury induced by IR in pancreas. The obstruction of gastro-duodenal and inferior splenic arteries induced pancreatic IR in male Wistar rats. Melatonin was intraperitoneally administered before or/and after IR injury. The animals were killed at 24 and 48 hr after reperfusion and there were evaluated parameters of oxidative stress (lipoperoxides, superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione), glandular endocrine and exocrine function (lipase, amylase, insulin) and cell injury (apoptosis and necrosis). The IR induced a marked enhancement of oxidative stress and impaired pancreatic function. The histological analysis showed that IR induced acute pancreatitis with the accumulation of inflammatory infiltrate, disruption of tissue structure, cell necrosis and hemorrhage. Melatonin administration before or after pancreatic IR prevented all tissue markers of oxidative stress, biochemical and histological signs of apoptosis and necrosis, and restored glandular function. No histological signs of pancreatitis were observed 48 hr after reperfusion in 80% of the animals treated with melatonin, with only a mild edematous pancreatitis being observed in the remaining rats. Preventive or therapeutic administration of melatonin protected against the induction of oxidative stress and tissue injury, and restored cell function in experimental pancreatic IR in rats.

First events from the CNGS neutrino beam detected in the OPERA experiment

Abstract: The OPERA neutrino detector at the underground Gran Sasso Laboratory (LNGS) was designed to perform the first detection of neutrino oscillations in appearance mode, through the study of nu_mu to nu_tau oscillations. The apparatus consists of a lead/emulsion-film target complemented by electronic detectors. It is placed in the high-energy, long-baseline CERN to LNGS beam (CNGS) 730 km away from the neutrino source. In August 2006 a first run with CNGS neutrinos was successfully conducted. A first sample of neutrino events was collected, statistically consistent with the integrated beam intensity. After a brief description of the beam and of the various sub-detectors, we report on the achievement of this milestone, presenting the first data and some analysis results.

Population Pharmacokinetics of High-Dose Methotrexate in Children with Acute Lymphoblastic Leukaemia

Abstract: Objective: To develop and a priori validate a methotrexate population pharmacokinetic model in children with acute lymphoblastic leukaemia (ALL), receiving high-dose methotrexate followed by folinic acid rescue, identifying the covariates that could explain part of the pharmacokinetic variability of methotrexate.

Multilocular Cystic Renal Cell Carcinoma

Abstract: The 2004 World Health Organization (WHO) classification of kidney tumors recognizes multilocular cystic renal cell carcinoma (MCRCC) as a rare variant of clear cell renal cell carcinoma with a good prognosis. Available information on its clinical significance is limited. The study cohort included 45 MCRCC cases classified according to 2004 WHO criteria obtained through a multi-institutional international search. Most patients had unilateral MCRCC with no side predominance that was found incidentally; 62% were men, but women had tumors at an earlier age ( P = .385). MCRCC occurred slightly more often in men than in women (1.7:1). At diagnosis, 82% of patients had stage T1 and 16%, stage T2; 1 patient had stage T3. The Fuhrman grade was 1 (62%) or 2 (38%), with smaller tumors (≤4 cm) most likely Fuhrman grade 1 ( P = .911). All 45 patients were alive with no evidence of disease at mean follow-up of 66.1 months, confirming an extremely good prognosis after surgery and a 5-year disease-specific survival rate of 100%. To rename this tumor as multilocular cystic renal cell neoplasm of low malignant potential might help urologists approach the patients conservatively.