547 research outputs found
Modeling of the acute toxicity of benzene derivatives by complementary QSAR methods
A data set containing acute toxicity values (96-h LC50) of 69 substituted benzenes for fathead minnow (Pimephales promelas) was investigated with two Quantitative Structure- Activity Relationship (QSAR) models, either using or not using molecular descriptors, respectively. Recursive Neural Networks (RNN) derive a QSAR by direct treatment of the molecular structure, described through an appropriate graphical tool (variable-size labeled rooted ordered trees) by defining suitable representation rules. The input trees are encoded by an adaptive process able to learn, by tuning its free parameters, from a given set of structureactivity training examples. Owing to the use of a flexible encoding approach, the model is target invariant and does not need a priori definition of molecular descriptors. The results obtained in this study were analyzed together with those of a model based on molecular descriptors, i.e. a Multiple Linear Regression (MLR) model using CROatian MultiRegression selection of descriptors (CROMRsel). The comparison revealed interesting similarities that could lead to the development of a combined approach, exploiting the complementary characteristics of the two approaches
Synthesis, radiolabelling and in vitro and in vivo evaluation of a novel fluorinated ABP688 derivative for the PET imaging of metabotropic glutamate receptor subtype 5
(E)-3-(Pyridin-2-ylethynyl)cyclohex-2-enone O-(2-(3-18F-fluoropropoxy)ethyl) oxime ([18F]-PSS223) was evaluated
in vitro and in vivo to establish its potential as a PET tracer for imaging metabotropic glutamate receptor subtype
5 (mGluR5). [18F]-PSS223 was obtained in 20% decay corrected radiochemical yield whereas the non-radioactive
PSS223 was accomplished in 70% chemical yield in a SN2 reaction of common intermediate mesylate 8 with potassium
fluoride. The in vitro binding affinity of [18F]-PSS223 was measured directly in a Scatchard assay to give Kd =
3.34 ± 2.05 nM. [18F]-PSS223 was stable in PBS and rat plasma but was significantly metabolized by rat liver microsomal
enzymes, but to a lesser extent by human liver microsomes. Within 60 min, 90% and 20% of [18F]-PSS223 was
metabolized by rat and human microsome enzymes, respectively. In vitro autoradiography on horizontal rat brain
slices showed heterogeneous distribution of [18F]-PSS223 with the highest accumulation in brain regions where
mGluR5 is highly expressed (hippocampus, striatum and cortex). Autoradiography in vitro under blockade conditions
with ABP688 confirmed the high specificity of [18F]-PSS223 for mGluR5. Under the same blocking conditions but using
the mGluR1 antagonist, JNJ16259685, no blockade was observed demonstrating the selectivity of [18F]-PSS223
for mGluR5 over mGluR1. Despite favourable in vitro properties of [18F]-PSS223, a clear-cut visualization of mGluR5-
rich brain regions in vivo in rats was not possible mainly due to a fast clearance from the brain and low metabolic
stability of [18F]-PSS223
Risk assessment in the recovery of food for social solidarity purposes: preliminary data
The most recent study, conducted by Politecnico of Milan, on food surplus management in Italy, entitled Surplus Food Management Against Food Waste, shows that in the Italian food supply chain, the food surplus is around to 5.5 million tons/year, and the amount of food wasted is around to 5.1 million tons/year. During 2015, the charitable organizations (COs) belonging to Italian Food Bank Network, active in recovering and distributing food for social solidarity\u2019s purposes, reused 381.345 tons of food from 2.292 donors. The main supplying sources of the Banco Alimentare Network are: food industries, organized large-scale retail trade and collective catering service. The aim of this study was to analyze several aspects of the food surplus recovery thanks to the collaboration with the Fondazione Banco Alimentare Onlus (FBAO) and Caritas Italiana. In particular, two main features were analyzed in the food recovery chain: i) the microbiological profiles of specific food categories recovered from catering service with the aim to evaluate their conformity in relation to food safety and process criteria. For this purpose 11 samples were analyzed in four different moments: - T0: same day of the collection; - T1: after four hours of storage at 4\ub0C; - T2: 24 hours from the collection (storage at 4\ub0C);- T3: after four days at frozen storage (-18\ub0C).For all samples several were investigated microbiological parameters: enumeration of Mesophilic aerobic bacteria (AFNOR 3M 01/1-09/89), enumeration of Enterobacteriaceae (AFNOR 3M 01/06-09/97), enumeration of E. coli (AFNOR 3M 01/08-06/01), enumeration of coagulase-positive Staphylococci AFNOR 3M 01/ 9-04/03 A), enumeration of Bacillus cereus (UNI EN ISO 7932:2005), research of Salmonella spp. (UNI EN ISO 6579 (2008b) and research of Listeria monocytogenes (AFNOR BRD 07/4-09/98 (AFNOR, 2010a)). Furthermore, ii) the volunteer\u2019s knowledge on the correct hygienic procedures during the recovery, were evaluated by the 71 questionnaires with the aim to prevent foodborne diseases. The results show that the recovery of surplus from catering service and their reuse at COs should be planned with correct procedures, and the volunteer\u2019s knowledge on the hygienic aspects appear to be a critical point. The recovery and the charitable activities require an appropriate assessment and careful risk analysis, in order to manage the complexity of no profit organization
Dual resonance mechanisms facilitating enhanced optical transmission in coaxial waveguide arrays
We experimentally and computationally demonstrate high transmission through arrays of coaxial apertures
with different geometries and arrangements in silver films. By studying both periodic and random arrangements
of apertures, we were able to isolate transmission enhancement phenomena owing to surface plasmon
effects from those owing to the excitation of cylindrical surface plasmons within the apertures themselves.This work was partially supported by the Office of
Naval Research. The support
of the Australian Research Council through its
Centers of Excellence, Federation Fellow, and Discovery
Programs is acknowledged
Effects of Prandial Versus Fasting Glycemia on Cardiovascular Outcomes in Type 2 Diabetes: The HEART2D trial
OBJECTIVE—Hyperglycemia and Its Effect After Acute Myocardial Infarction on Cardiovascular Outcomes in Patients With Type 2 Diabetes Mellitus (HEART2D) is a multinational, randomized, controlled trial designed to compare the effects of prandial versus fasting glycemic control on risk for cardiovascular outcomes in patients with type 2 diabetes after acute myocardial infarction (AMI)
Effects of Prandial Versus Fasting Glycemia on Cardiovascular Outcomes in Type 2 Diabetes: The HEART2D trial
OBJECTIVE—Hyperglycemia and Its Effect After Acute Myocardial Infarction on Cardiovascular Outcomes in Patients With Type 2 Diabetes Mellitus (HEART2D) is a multinational, randomized, controlled trial designed to compare the effects of prandial versus fasting glycemic control on risk for cardiovascular outcomes in patients with type 2 diabetes after acute myocardial infarction (AMI)
ULEARN: Personalised Learner’s Profile Based On Dynamic Learning Style Questionnaire
The file attached to this record is the author's final peer reviewed version.E-Learning recommender system effectiveness re- lies upon their ability to recommend appropriate learning con- tents according to the learner learning style and preferences. An effective approach to handle the learner preferences is to build an efficient learner profile in order to gain adaptation and individualisation of the learning environment. It is usually necessary to know learning style and preferences of the learner on a domain before adapting the learning process and course content. This study focuses on identifying the learning styles of students in order to adapt the learning process and course content. ULEARN is an adaptive recommender learning system designed to provide learners with personalised learning environment such as course learning objects that match their adaptive profile. This paper presents the algorithm used in ULEARN to reduce dynamically the number of questions in Felder-Silverman learning style ques- tionnaire used to initialise the adaptive learner profile. Firstly, the questionnaire is restructured into four groups, one for each learning style dimension; and a study is carried out to determine the order in which questions will be asked in each dimension. Then an algorithm is built upon this ranking of questions to calculate dynamically the initial learning style of the user as they go through the questionnaire
Voluntary self-poisoning as a cause of admission to a tertiary hospital internal medicine clinic in Piraeus, Greece within a year
BACKGROUND: Out of 1705 patients hospitalised for various reasons in the 3(rd) Internal Medicine Department of the Regional General Hospital of Nikaea, in Piraeus, 146(8,5%) persons were admitted for drug intoxication between November 1999 and November 2000. METHODS: On average, these persons [male 50(34,2%) – female 96(65,8%)] were admitted to the hospital within 3.7 hours after taking the drug. RESULTS: The drugs that were more frequently taken, alone or in combination with other drugs, were sedatives (67.1%), aspirins and analgesics (mainly paracetamol) (43.5%). 38.3% of patients had a mental illness history, 31.5% were in need of psychiatric help and 45.2% had made a previous suicide attempt. No death occurred during the above period and the outcome of the patients' health was normal. After mental state examination, the mental illnesses diagnosed were depression (20.96%), psychosis (15.32%), dysthymic disorder (16,2%), anxiety disorder (22.58%) and personality disorder (8.87%). CONCLUSIONS: Self-poisoning remains a crucial problem. The use of paracetamol and sedatives are particularly important in the population studied. Interpersonal psychiatric therapy may be a valuable treatment after people tried to poison themselves
Cardiovascular Risk Factors Among Youth With and Without Type 2 Diabetes: Differences and possible mechanisms
OBJECTIVE—To compare cardiovascular disease (CVD) risk factors among recently diagnosed youth with type 2 diabetes and nondiabetic youth and investigate whether demographic, behavioral, or metabolic factors might account for observed differences
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