Double dynamical regime of confined water

The Van Hove self correlation function of water confined in a silica pore is calculated from Molecular Dynamics trajectories upon supercooling. At long time in the $\alpha$ relaxation region we found that the behaviour of the real space time dependent correlators can be decomposed in a very slow, almost frozen, dynamics due to the bound water close to the substrate and a faster dynamics of the free water which resides far from the confining surface. For free water we confirm the evidences of an approach to a crossover mode coupling transition, previously found in Q space. In the short time region we found that the two dynamical regimes are overimposed and cannot be distinguished. This shows that the interplay between the slower and the faster dynamics emerges in going from early times to the $\alpha$ relaxation region, where a layer analysis of the dynamical properties can be performed.Comment: 6 pages with 9 figures. RevTeX. Accepted for pulbication in J. Phys. Cond. Mat

New high-performance liquid chromatography-dad method for analytical determination of arbutin and hydroquinone in rat plasma

Natural substances present in herbal preparations should be carefully used because they can give toxic or therapeutic effects despite of their amount or the way of administration. The safety of products of vegetable origin must be assessed before commercialisation by monitoring the active ingredients and their metabolites. This study was therefore designed to identify and quantify arbutin and its metabolite hydroquinone, naturally present in Arctostaphylos uva-ursi (L.) Spreng plant in rat plasma, after an acute and subacute administration of aqueous arbutin solution in Wistar rats. For this purpose a reversed-phase high-performance liquid chromatography coupled with photodiode array detection was developed to assess the pharmacokinetic of arbutin and hydroquinone in plasma of female rats treated with aqueous arbutin solutions. The detection (arbutin: 0.0617 µg/ml and hydroquinone 0.0120 µg/ml) and quantification (arbutin: 0.2060 µg/ml and hydroquinone: 0.0400 µg/ml) limits were determined. At the arbutin concentration level of 10.7 µg/ml repeatability was 13.33% and its recovery 93.4±6.93%, while at the hydroquinone concentration level of 10.6 µg/ml repeatability was 11.66% and its recovery 92.9±7.75%. Furthermore the method was fully validated and the obtained data indicate that the new method provides good performances

Outdoor Ageing of an Ethylene-Propylene Copolymer: A Positron Annihilation Study

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Slow dynamics of a confined supercooled binary mixture II: Q space analysis

We report the analysis in the wavevector space of the density correlator of a Lennard Jones binary mixture confined in a disordered matrix of soft spheres upon supercooling. In spite of the strong confining medium the behavior of the mixture is consistent with the Mode Coupling Theory predictions for bulk supercooled liquids. The relaxation times extracted from the fit of the density correlator to the stretched exponential function follow a unique power law behavior as a function of wavevector and temperature. The von Schweidler scaling properties are valid for an extended wavevector range around the peak of the structure factor. The parameters extracted in the present work are compared with the bulk values obtained in literature.Comment: 8 pages with 8 figures. RevTeX. Accepted for publication in Phys. Rev.

Capgras-like syndrome in a patient with an acute urinary tract infection.

Delusional misidentification syndromes are a group of delusional phenomena in which patients misidentify familiar persons, objects, or themselves, believing that they have been replaced or transformed. In 25%-40% of cases, misidentification syndromes have been reported in association with organic illness. We report an acute episode of Capgras-like delusion lasting 8 days, focused on the idea that people were robots with human bodies, in association with an acute urinary infection. To our knowledge, this is the first case report associating urinary tract infection with Capgras-like syndrome. Awareness of the prevalence of delusional misidentification syndromes associated with acute medical illness should promote diligence on the part of clinicians in recognizing this disorder

Exposure to polychlorinated biphenyls and hexachlorobenzene, semen quality and testicular cancer risk

PURPOSE: We carried out a case-control study to investigate the possible role of occupational and environmental exposure to endocrine disruptors in the onset of testicular cancer (TC). METHODS: We evaluated 125 TC patients and 103 controls. Seminal fluid examination and organochlorine analysis were performed in all subjects. Cases and controls were also interviewed using a structured questionnaire to collect demographic information, residence, andrological medical history and dietary information. RESULTS: We found that a higher level of reproductive tract birth defects was associated with a higher risk of TC. With regard to diet, cases reported a higher consumption of milk and dairy products than controls. Overall, there was a statistically significant increase in TC risk in cases with detectable values of total polychlorinated organic compounds against controls (14.4 vs. 1.0 %; p < 0.001). TC patients with detectable levels of organochlorines had lower mean semen parameters than those with undetectable levels, although this difference was not statistically significant. CONCLUSION: The International Agency for Research on Cancer recently included dioxin-like polychlorinated biphenyls (PCBs) in Group 1 of known human carcinogens. Our study confirmed and identified various risk factors for testicular cancer: cryptorchidism, consumption of milk and dairy products, parents' occupation and serum concentration of hexachlorobenzene and PCBs and, for the first time, we showed the correlation between semen quality and the serum concentration of these pollutants

Irredundant Triangular Decomposition

Triangular decomposition is a classic, widely used and well-developed way to represent algebraic varieties with many applications. In particular, there exist sharp degree bounds for a single triangular set in terms of intrinsic data of the variety it represents, and powerful randomized algorithms for computing triangular decompositions using Hensel lifting in the zero-dimensional case and for irreducible varieties. However, in the general case, most of the algorithms computing triangular decompositions produce embedded components, which makes it impossible to directly apply the intrinsic degree bounds. This, in turn, is an obstacle for efficiently applying Hensel lifting due to the higher degrees of the output polynomials and the lower probability of success. In this paper, we give an algorithm to compute an irredundant triangular decomposition of an arbitrary algebraic set $W$ defined by a set of polynomials in C[x_1, x_2, ..., x_n]. Using this irredundant triangular decomposition, we were able to give intrinsic degree bounds for the polynomials appearing in the triangular sets and apply Hensel lifting techniques. Our decomposition algorithm is randomized, and we analyze the probability of success

The Use of a Variable Representing Compliance Improves Accuracy of Estimation of the Effect of Treatment Allocation Regardless of Discontinuation in Trials with Incomplete Follow-up

Abstract–In Clinical Trials, not all randomized patients follow the course of treatment they are allocated to. The potential impact of such deviations is increasingly recognized, and it has been one of the reasons for a redefinition of the targets of estimation (“Estimands”) in the ICH E9 draft Addendum. Among others, the effect of treatment assignment, regardless of the adherence, appears an Estimand of practical interest, in line with the intention-to-treat principle. This study aims at evaluating the performance of different estimation techniques in trials with incomplete post-discontinuation follow-up when a “treatment-policy” strategy is implemented. To achieve that, we have (i) modeled and visualized as directed acyclic diagram a reasonable data-generating model; (ii) investigated which set of variables allows identification and estimation of such effect; (iii) simulated 10,000 trials in Major Depressive Disorder, with varying real treatment effects, proportions of patients discontinuing the treatment, and incomplete follow-up. Our results suggest that, at least in a “Missing at Random” setting, all studied estimation methods increase their performance when a variable representing compliance is used. This effect is more pronounced the higher the proportion of post-discontinuation follow-up is

Method for speciation of organoarsenic in mussels by liquid chromatography coupled to electrospray ionization and QTRAP tandem mass spectrometry.

Arsenic toxicity to humans critically depends on the chemical form of the arsenic. The Expert Committee of the Food and Agriculture Organization and the World Health Organization defined a tolerable intake only for inorganic arsenic, although the toxicity of some organoarsenic compounds is known. Arsenobetaine (AsB), arsenocholine (AsC), dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA) are abundant in shellfish. We present a fast and reliable method for identification of the type of organic arsenic in mussels by using liquid chromatography coupled to electrospray ionization tandem mass spectrometry on triple quadrupole with parallel determination of total arsenic by atomic absorption spectrophotometry. The method was validated by evaluating mean recoveries, repeatability, specificity, limits of quantification, and limits of detection that produced satisfactory results. The method was used to carry out the first survey of the concentrations of AsB, AsC, MMA, and DMA in seafood from southern Italy. Total As concentrations ranged from 1.38 to 12.79 mg/kg. AsB and DMA were detected in all samples (AsB: 0.72 to 10.36 mg/kg; DMA: 0.28 to 1.08 mg/kg), and concentrations of AsC and MMA ranged from 0.20 to 1.53 mg/kg. This method allowed us to rapidly and inexpensively identify arsenic types in fishery products and would be suitable for routine detection of organoarsenic compounds in molluscs

Meta-analysis of stomatitis in clinical studies of everolimus: incidence and relationship with efficacy.

BackgroundEverolimus, an oral mammalian target of rapamycin (mTOR) inhibitor, is used to treat solid tumors and tuberous sclerosis complex (TSC). Stomatitis, an inflammation of the mucous membranes of the mouth, is a common adverse event associated with mTOR inhibitors, including everolimus. We conducted a meta-analysis of data from seven randomized, double-blind phase 3 clinical trials of everolimus to determine the clinical impact of stomatitis on efficacy and safety.Patients and methodsData were pooled from the safety sets of solid tumor [breast cancer (BOLERO-2 and BOLERO-3), renal cell carcinoma (RECORD-1), carcinoid tumors (RADIANT-2), and pancreatic neuroendocrine tumors (RADIANT-3)] and TSC studies (EXIST-1 and EXIST-2). Data from solid tumor trials and TSC trials were analyzed separately.ResultsThe rate of stomatitis was 67% in the solid tumor trials (973/1455 patients) and 70% in the TSC trials (110/157 patients). Most stomatitis events were grade 1/2, with grade 3/4 events reported in only 9% (solid tumor trials) and 8% (TSC trials) of patients. Low TSC patient numbers prevented an in-depth evaluation of stomatitis and response. In the solid tumor trials, most first stomatitis episodes (89%; n = 870) were observed within 8 weeks of starting everolimus. Patients with stomatitis occurring within 8 weeks of everolimus initiation had longer progression-free survival (PFS) than everolimus-treated patients without stomatitis in BOLERO-2 {8.5 versus 6.9 months, respectively; hazard ratio (HR), 0.78 [95% confidence interval (CI), 0.62-1.00]} and RADIANT-3 [13.9 versus 8.3 months, respectively; HR, 0.70 (95% CI, 0.48-1.04)]. A similar trend was observed in RECORD-1 [HR, 0.90 (95% CI, 0.66-1.22)] and RADIANT-2 [HR, 0.87 (95% CI, 0.61-1.22)] but not in BOLERO-3 [HR, 1.01 (95% CI, 0.75-1.36)].ConclusionsStomatitis did not adversely affect PFS, supporting the administration of everolimus in accordance with standard management guidelines