72 research outputs found

    The “Bitul B’shishim (one part in sixty)”: is a Jewish conditional prohibition of the Talmud the oldest-known testimony of quantitative analytical chemistry?

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    Accomplishments of Hellenistic science and technology in some fields, such as mathematics, physical cosmology and engineering, has recently been re-evaluated and can be considered as of the same level that the scientific revolution in Western Europe reached at the beginning of the XVII century CE. Information on the level of chemical science is scanty; however, independent ancient sources such as the Jewish Talmud can yield significant clues. The still existing dietary laws include a practice to assess the acceptability of food mixtures with two complementary assessment techniques. One enforces a specific minimum mixing ratio (1:60) of unacceptable-to-acceptable ingredients, the other uses a sensory assessment to exclude the presence of a tasty unacceptable ingredient. This practice is likely the first historical example of quantitative analytical chemistry. This article collects clues that this approach is rooted in the implicit acceptance by Hellenistic chemical science of an atomic paradigm and on the awareness that interaction of different matter yields product that are different from the starting ones. Quantitative assessment of the presence of unacceptable ingredients by sensorial assessment or by mixing ratio likely points to a forgotten practice of Hellenistic experimental pharmacology and physiology to test the efficacy of drugs and poisons, that was performed in animals, with the use of a control group, and on human subjects

    Measurement of Glutathionylated Haemoglobin by MALDI-ToF Mass Spectrometry as a Biomarker of Oxidative Stress in Heavy Smokers and in Occupational Obese Subjects

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    Glutathionyl-haemoglobin (Hb-SSG) is a minor form of haemoglobin characterized by the presence of a disulfide bond between the β-93 cysteine residue and the thiol group of glutathione. Hb-SSG is naturally present in the erythrocytes at levels comparable to those of glycated haemoglobin and can be measured by MALDI mass spectrometry on very small samples of erythrocytes from peripheral blood. Since Hb-SSG has been recognized as a sensitive biomarker of oxidative stress in several degenerative diseases (diabetes, hyperlipidemia, kidney disease) and in healthy workers exposed to glutathione-depleting toxic agents such as butadiene, we have measured for the first time the levels of Hb-SSG in two groups: healthy heavy cigarette smokers and overweight-obese

    The Exploration and Practice of Party Member of College Students rdquo;Recognizing Position and Taking Responsibility for a Model”

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    AbstractNowadays, it has become more important to strengthen the education, management and training work of the party members of college students. Our school has carried out the party members of college students. rdquo;recognizing position and taking responsibility for a model” activity for two years. And obtained some experience. The party members of college students rdquo;recognizing position and taking responsibility for a model” activity should set up scientific positions, define their responsibilities clearly and strengthen the management and assessment

    Phylogeography and genomic epidemiology of SARS-CoV-2 in Italy and Europe with newly characterized Italian genomes between February-June 2020

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    Il ruolo della Corte di giustizia nella definizione della politica economica e monetaria europea

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    Il ruolo giocato dalla Corte di giustizia nel campo della politica economica e della politica monetaria è stato importante quanto sottostimato. Le due competenze dell’Unione sono profondamente differenti - ciascuna dotata di significative peculiarità - e tuttavia strettamente interconnesse. Definire i confini incerti tra politica economica e politica monetaria è stato il ruolo più importante svolto dalla Corte in questo campo. Questo ha comportato una precisazione dei ruoli delle istituzioni chiamate ad agire - Commissione, Consiglio, Banca centrale - così come dei limiti all’indipendenza dell’istituto di emissione, ma anche della ripartizione di competenze tra Stati e Unione. Dal 2012, un’ulteriore funzione è stata esercitata dalla Corte: la verifica della legittimità dell’intervento straordinario della BCE nell’economia per gestire le crisi. L’assenza nei trattati europei di disposizioni specifiche che contemplassero un ruolo della Banca come prestatore di ultima istanza o nella gestione delle crisi economiche e finanziarie spiega bene le contestazioni dell’ultimo decennio, così come la necessità di pronunce autorevoli da parte della Suprema Corte europea. Queste si collocano a buon diritto nel solco della giurisprudenza in tema di rule of law e di garanzia del rispetto dei principi generali nell’ordinamento europeo

    PRISM (Polarized Radiation Imaging and Spectroscopy Mission): A White Paper on the Ultimate Polarimetric Spectro-Imaging of the Microwave and Far-Infrared Sky

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    PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in response to the Call for White Papers for the definition of the L2 and L3 Missions in the ESA Science Programme. PRISM would have two instruments: (1) an imager with a 3.5m mirror (cooled to 4K for high performance in the far-infrared---that is, in the Wien part of the CMB blackbody spectrum), and (2) an Fourier Transform Spectrometer (FTS) somewhat like the COBE FIRAS instrument but over three orders of magnitude more sensitive. Highlights of the new science (beyond the obvious target of B-modes from gravity waves generated during inflation) made possible by these two instruments working in tandem include: (1) the ultimate galaxy cluster survey gathering 10e6 clusters extending to large redshift and measuring their peculiar velocities and temperatures (through the kSZ effect and relativistic corrections to the classic y-distortion spectrum, respectively) (2) a detailed investigation into the nature of the cosmic infrared background (CIB) consisting of at present unresolved dusty high-z galaxies, where most of the star formation in the universe took place, (3) searching for distortions from the perfect CMB blackbody spectrum, which will probe a large number of otherwise inaccessible effects (e.g., energy release through decaying dark matter, the primordial power spectrum on very small scales where measurements today are impossible due to erasure from Silk damping and contamination from non-linear cascading of power from larger length scales). These are but a few of the highlights of the new science that will be made possible with PRISM.Comment: 20 pages Late

    EVALITA Evaluation of NLP and Speech Tools for Italian - December 17th, 2020

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    Welcome to EVALITA 2020! EVALITA is the evaluation campaign of Natural Language Processing and Speech Tools for Italian. EVALITA is an initiative of the Italian Association for Computational Linguistics (AILC, http://www.ai-lc.it) and it is endorsed by the Italian Association for Artificial Intelligence (AIxIA, http://www.aixia.it) and the Italian Association for Speech Sciences (AISV, http://www.aisv.it)

    Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

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    Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

    The Redox Potential of the β-93-Cysteine Thiol Group in Human Hemoglobin Estimated from In Vitro Oxidant Challenge Experiments

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    Glutathionyl hemoglobin is a minor form of hemoglobin with intriguing properties. The measurement of the redox potential of its reactive β-93-Cysteine is useful to improve understanding of the response of erythrocytes to transient and chronic conditions of oxidative stress, where the level of glutathionyl hemoglobin is increased. An independent literature experiment describes the recovery of human erythrocytes exposed to an oxidant burst by measuring glutathione, glutathione disulfide and glutathionyl hemoglobin in a two-hour period. This article calculates a value for the redox potential E0 of the β-93-Cysteine, considering the erythrocyte as a closed system at equilibrium described by the Nernst equation and using the measurements of the literature experiment. The obtained value of E0 of −121 mV at pH 7.4 places hemoglobin as the most oxidizing thiol of the erythrocyte. By using as synthetic indicators of the concentrations the electrochemical potentials of the two main redox pairs in the erythrocytes, those of glutathione–glutathione disulfide and of glutathionyl–hemoglobin, the mechanism of the recovery phase can be hypothesized. Hemoglobin acts as the redox buffer that scavenges oxidized glutathione in the oxidative phase and releases it in the recovery phase, by acting as the substrate of the NAD(P)H-cofactored enzymes

    Center-of-Mass iso-Energetic Collision-Induced Decomposition in Tandem Triple Quadrupole Mass Spectrometry

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    Two scan modes of the triple quadrupole tandem mass spectrometer, namely Collision Induced Dissociation Precursor Ion scan and Neutral Loss scan, allow selectively pinpointing, in a complex mixture, compounds that feature specific chemical groups, which yield characteristic fragment ions or are lost as distinctive neutral fragments. This feature of the triple quadrupole tandem mass spectrometer allows the non-target screening of mixtures for classes of components. The effective (center-of-mass) energy to achieve specific fragmentation depends on the inter-quadrupole voltage (laboratory-frame collision energy) and on the masses of the precursor molecular ion and of the collision gas, through a non-linear relationship. Thus, in a class of homologous compounds, precursor ions activated at the same laboratory-frame collision energy face different center-of-mass collision energy, and therefore the same fragmentation channel operates with different degrees of efficiency. This article reports a linear equation to calculate the laboratory-frame collision energy necessary to operate Collision-Induced Dissociation at the same center-of-mass energy on closely related compounds with different molecular mass. A routine triple quadrupole tandem mass spectrometer can operate this novel feature (iso-energetic collision-induced dissociation scan; i-CID) to analyze mixtures of endogenous metabolites by Precursor Ion and Neutral Loss scans. The latter experiment also entails the hitherto unprecedented synchronized scanning of all three quadrupoles of the triple quadrupole tandem mass spectrometer. To exemplify the application of this technique, this article shows two proof-of-principle approaches to the determination of biological mixtures, one by Precursor Ion analysis on alpha amino acid derivatized with a popular chromophore, and the other on modified nucleosides with a Neutral Fragment Loss scan
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