223 research outputs found

    Considerazioni biologiche sui voli spaziali eseguiti fino ad oggi

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    L'A. espone dapprima i risultati di interesse biologicoconseguiti nei primi voli spaziali, suborbitali ed orbitali, realizzati dai sovietici,dagli americani e dai francesi, con l'impiego di animali da esperimentodi specie diverse. Sul presupposto di tali ricerche venivano lanciati, per voliorbitali, i sovietici Gagarin e Titov.Nei due astronauti le modificazioni delle grandezze circolatorie durantela fase di ipergravità non differivano dai dati rilevati in centrifuga. In assenzadi gravità le variazioni cardiache e respiratorie furono quasi nulle, mentrenon si rilevarono disturbi nei movimenti e nella coordinazione muscolare.Solo Titov, per qualche istante del volo, presentò vertigini e nausea cheinsorgevano con i movimenti della testa.Gli Stati Uniti eseguivano i loro primi voli spaziali umani suborbitali,con i lanci di Shepard e Grissom.Dopo alcuni voli orbitali sperimentali realizzavano il loro primo voloorbitale umano con il lancio del tenente colonnello Glenn. I dati biologiciteletrasmessi fecero rilevare un comportamento dell'apparato cardiovascolare,nelle fasi di iper e di zero gravità, che rientrava nelle previsioni. Le funzionisensoriali non presentarono alterazioni, ove si eccettui una riduzione dellavisione crepuscolare, né si ebbero, in condizioni di zero-gravità, disturbilabirintici, che pure l'astronauta cercò di provocare con movimenti dellatesta. L'alimentazione, eseguita con cibi appositamente preparati, nonpresentò difficoltà

    Determination of carbonyl compounds in exhaled breath by on-sorbent derivatization coupled with thermal desorption and gas chromatography-tandem mass spectrometry

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    A reliable method for the determination of carbonyl compounds in exhaled breath based on on-sorbent derivatization coupled with thermal desorption and gas chromatography-tandem mass spectrometry is described. The analytical performances were optimized for a mixture of C2-C9 aldehydes and C3-C9 ketones, particularly interesting for clinical applications, by using an internal standard and applying a 2^3 full factorial design. A volume of sample (250 ml) was loaded at 50 ml min-1 into a Tenax GR sorbent tube containing 130 nmol of O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride. All compounds showed a limit of detection lower than 200 pptv. The yield of the derivatization procedure was normalized by adding to the sample a known amount of 6D-acetone as an internal standard. This allowed halving the relative standard deviation to 10% and 15% for the mono-and di-carbonyl compounds, respectively, thus improving reliability. The optimized method was applied to the determination of carbonyl compounds in 12 breath samples collected from four patients suffering from heart failure during hospitalization

    Extending scientific computing system with structural quantum programming capabilities

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    We present a basic high-level structures used for developing quantum programming languages. The presented structures are commonly used in many existing quantum programming languages and we use quantum pseudo-code based on QCL quantum programming language to describe them. We also present the implementation of introduced structures in GNU Octave language for scientific computing. Procedures used in the implementation are available as a package quantum-octave, providing a library of functions, which facilitates the simulation of quantum computing. This package allows also to incorporate high-level programming concepts into the simulation in GNU Octave and Matlab. As such it connects features unique for high-level quantum programming languages, with the full palette of efficient computational routines commonly available in modern scientific computing systems. To present the major features of the described package we provide the implementation of selected quantum algorithms. We also show how quantum errors can be taken into account during the simulation of quantum algorithms using quantum-octave package. This is possible thanks to the ability to operate on density matrices

    Quantum geometry and quantum algorithms

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    Motivated by algorithmic problems arising in quantum field theories whose dynamical variables are geometric in nature, we provide a quantum algorithm that efficiently approximates the colored Jones polynomial. The construction is based on the complete solution of Chern-Simons topological quantum field theory and its connection to Wess-Zumino-Witten conformal field theory. The colored Jones polynomial is expressed as the expectation value of the evolution of the q-deformed spin-network quantum automaton. A quantum circuit is constructed capable of simulating the automaton and hence of computing such expectation value. The latter is efficiently approximated using a standard sampling procedure in quantum computation.Comment: Submitted to J. Phys. A: Math-Gen, for the special issue ``The Quantum Universe'' in honor of G. C. Ghirard

    MS-based targeted profiling of oxylipins in COVID-19: A new insight into inflammation regulation

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    The key role of inflammation in COVID-19 induced many authors to study the cytokine storm, whereas the role of other inflammatory mediators such as oxylipins is still poorly understood. IMPRECOVID was a monocentric retrospective observational pilot study with COVID-19 related pneumonia patients (n = 52) admitted to Pisa University Hospital between March and April 2020. Our MS-based analytical platform permitted the simultaneous determination of sixty plasma oxylipins in a single run at ppt levels for a comprehensive characterisation of the inflammatory cascade in COVID-19 patients. The datasets containing oxylipin and cytokine plasma levels were analysed by principal component analysis (PCA), computation of Fisher's canonical variable, and a multivariate receiver operating characteristic (ROC) curve. Differently from cytokines, the panel of oxylipins clearly differentiated samples collected in COVID-19 wards (n = 43) and Intensive Care Units (ICUs) (n = 27), as shown by the PCA and the multivariate ROC curve with a resulting AUC equal to 0.92. ICU patients showed lower (down to two orders of magnitude) plasma concentrations of anti-inflammatory and pro-resolving lipid mediators, suggesting an impaired inflammation response as part of a prolonged and unsolvable pro-inflammatory status. In conclusion, our targeted oxylipidomics platform helped shedding new light in this field. Targeting the lipid mediator class switching is extremely important for a timely picture of a patient's ability to respond to the viral attack. A prediction model exploiting selected lipid mediators as biomarkers seems to have good chances to classify patients at risk of severe COVID-19

    Analysis of radiatively stable entanglement in a system of two dipole-interacting three-level atoms

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    We explore the possibilities of creating radiatively stable entangled states of two three-level dipole-interacting atoms in a Λ\Lambda configuration by means of laser biharmonic continuous driving or pulses. We propose three schemes for generation of entangled states which involve only the lower states of the Λ\Lambda system, not vulnerable to radiative decay. Two of them employ coherent dynamics to achieve entanglement in the system, whereas the third one uses optical pumping, i.e., an essentially incoherent process.Comment: Replaced with the final version; 14 pages, 6 figures; to appear in Phys. Rev. A, vol. 61 (2000

    Euphol, a tetracyclic triterpene, from Euphorbia tirucalli induces autophagy and sensitizes temozolomide cytotoxicity on glioblastoma cells

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    Glioblastoma (GBM) is the most frequent and aggressive type of brain tumor. There are limited therapeutic options for GBM so that new and effective agents are urgently needed. Euphol is a tetracyclic triterpene alcohol, and it is the main constituent of the sap of the medicinal plant Euphorbia tirucalli. We previously identified anti-cancer activity in euphol based on the cytotoxicity screening of 73 human cancer cells. We now expand the toxicological screening of the inhibitory effect and bioactivity of euphol using two additional glioma primary cultures. Euphol exposure showed similar cytotoxicity against primary glioma cultures compared to commercial glioma cells. Euphol has concentration-dependent cytotoxic effects on cancer cell lines, with more than a five-fold difference in the IC50 values in some cell lines. Euphol treatment had a higher selective cytotoxicity index (0.64-3.36) than temozolomide (0.11-1.13) and reduced both proliferation and cell motility. However, no effect was found on cell cycle distribution, invasion and colony formation. Importantly, the expression of the autophagy-associated protein LC3-II and acidic vesicular organelle formation were markedly increased, with Bafilomycin A1 potentiating cytotoxicity. Finally, euphol also exhibited antitumoral and antiangiogenic activity in vivo, using the chicken chorioallantoic membrane assay, with synergistic temozolomide interactions in most cell lines. In conclusion, euphol exerted in vitro and in vivo cytotoxicity against glioma cells, through several cancer pathways, including the activation of autophagy-associated cell death. These findings provide experimental support for further development of euphol as a novel therapeutic agent for GBM, either alone or in combination chemotherapy.The work was supported by the Amazonia Fitomedicamentos (FITO05/2012) Ltda. and Barretos Cancer Hospital, all from Brazil

    Produção de resinas ligno-fenol-formaldeĂ­do a partir do bagaço da cana-de-açĂșcar.

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    Este Comunicado TĂ©cnico visa apresentar recomendaçÔes para produção de resina ligno-fenol-formaldeĂ­do, em escala de laboratĂłrio, a partir da lignina extraĂ­da do bagaço da cana-de-açĂșcar e a prova de conceito de sua aplicação em placas de fibra de mĂ©dia densidade (MDF medium density fiberboard).bitstream/item/206193/1/CT-255.pd

    EGFR Tyrosine Kinase Inhibitors Activate Autophagy as a Cytoprotective Response in Human Lung Cancer Cells

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    Epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib have been widely used in patients with non-small-cell lung cancer. Unfortunately, the efficacy of EGFR-TKIs is limited because of natural and acquired resistance. As a novel cytoprotective mechanism for tumor cell to survive under unfavorable conditions, autophagy has been proposed to play a role in drug resistance of tumor cells. Whether autophagy can be activated by gefitinib or erlotinib and thereby impair the sensitivity of targeted therapy to lung cancer cells remains unknown. Here, we first report that gefitinib or erlotinib can induce a high level of autophagy, which was accompanied by the inhibition of the PI3K/Akt/mTOR signaling pathway. Moreover, cytotoxicity induced by gefitinib or erlotinib was greatly enhanced after autophagy inhibition by the pharmacological inhibitor chloroquine (CQ) and siRNAs targeting ATG5 and ATG7, the most important components for the formation of autophagosome. Interestingly, EGFR-TKIs can still induce cell autophagy even after EGFR expression was reduced by EGFR specific siRNAs. In conclusion, we found that autophagy can be activated by EGFR-TKIs in lung cancer cells and inhibition of autophagy augmented the growth inhibitory effect of EGFR-TKIs. Autophagy inhibition thus represents a promising approach to improve the efficacy of EGFR-TKIs in the treatment of patients with advanced non-small-cell lung cancer
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