4,376 research outputs found
Quantum Metallicity on the High-Field Side of the Superconductor-Insulator Transition
We investigate ultrathin superconducting TiN films, which are very close to
the localization threshold. Perpendicular magnetic field drives the films from
the superconducting to an insulating state, with very high resistance. Further
increase of the magnetic field leads to an exponential decay of the resistance
towards a finite value. In the limit of low temperatures, the saturation value
can be very accurately extrapolated to the universal quantum resistance h/e^2.
Our analysis suggests that at high magnetic fields a new ground state, distinct
from the normal metallic state occurring above the superconducting transition
temperature, is formed. A comparison with other studies on different materials
indicates that the quantum metallic phase following the magnetic-field-induced
insulating phase is a generic property of systems close to the disorder-driven
superconductor-insulator transition.Comment: 4 pages, 4 figures, published versio
Mycobacterium tuberculosis and whole genome sequencing: a practical guide and online tools available for the clinical microbiologist
Whole genome sequencing (WGS) has the potential to revolutionize the diagnosis of Mycobacterium tuberculosis (MTB) but the lack of bioinformatic expertise among clinical microbiologists is a barrier for adoption. Software products for analysis should be simple, free of charge, able to accept data directly from the sequencer (FASTQ files) and to provide the basic functionalities all-in-one. The main aim of this narrative review is to provide a practical guide for the clinical microbiologist, with little or no practical experience of WGS analysis, with a specific focus on software products tailored made for MTB analysis. With sequencing performed by an external provider, it is now feasible to implement WGS analysis in the routine clinical practice of any microbiology laboratory, with the potential to detect resistance weeks before traditional phenotypic culture methods, but the clinical microbiologist should be aware of the limitations of this approach
SIGLA - Sistema Integrato per il Monitoraggio e Gestione di Lagune ed Ambiente, sotto-azione CARLA Parte I : CARatterizzazione chimica e chimico-fisica e qualità acque LAguna di Cabras e Golfo di Oristano
È stata effettuata una prima caratterizzazione chimica e chimico-fisica della colonna d’acqua nella Laguna di Cabras tramite l’analisi di dati raccolti in precedenti indagini. Tali studi sono stati completati con campionamenti di acqua e misure in situ delle variabili idrologiche nella laguna e nel golfo di Oristano. Su questo set di dati sono state effettuate le analisi per individuare le relazioni tra le variabili misurate e per studiare le variabilità stagionali delle caratteristiche chimico-fisiche della colonna d’acqua.
Lo studio ha permesso la compilazione di un protocollo metodologico di indagine e di monitoraggio dello stato trofico e di salute di ambienti lagunari costieri.
I dati più recenti hanno mostrato come rispetto alle medie storiche, si sia avuto un aumento della temperatura e una diminuzione della salinità . Quest’ultima viene associata ad un limitato scambio tra la laguna ed il mare. I valori di ossigeno e pH non sono indicativi di un elevato stress ambientale, infatti non sono state rilevate condizioni di ipossia o anossia, e valori di pH superiori alla norma.
Tuttavia in precedenti campionamenti nell’estate 2002 sono stati descritti al fondo valori ipossici. Tali valori hanno indicato come la laguna sia periodicamente soggetta a crisi anossiche. Il netto calo di nutrienti rispetto agli anni ottanta-novanta è associato ad una diminuzione degli input d’acqua dolce nel periodo monitorato. Inoltre non è trascurabile l’influenza degli scambi tra sedimento e colonna d’acqua.
In conclusione, dagli studi condotti si può dedurre come nello specifico, nella Laguna di Cabras, lo stato trofico del sistema sia principalmente condizionato dagli input d’acqua dolce, e come questi condizionino anche gli scambi con il golfo. In aggiunta, data la diminuzione degli input di acqua dolce nel periodo monitorato e vista la relazione positiva tra volumi e nutrienti in entrata, il loro abbattimento in entrata tramite depurazione delle acque sembra essere un valido strumento di mitigazione e di recupero
Administration of Brevibacillus laterosporus spores as a poultry feed additive to inhibit house fly development in feces: A new eco-sustainable concept
ABSTRACT The success of a microbial pesticide application against house flies developing in manure should accomplish the uniform mixing of active ingredients with this breeding medium, thus enhancing residual effects. The oral administration of the entomopathogenic bacterium Brevibacillus laterosporus to caged poultry species allows the homogeneous incorporation of its active ingredients with fly breeding media. Feces from treated broilers or hens show toxicity against exposed fly adults and larvae. Insecticidal effects are concentration-dependent with a lethal median concentration (LC50) value of 1.34 × 108 and 0.61 × 108 spores/g of feces for adults and larvae, respectively. Manure toxicity against flies was maintained as long as chickens were fed a diet containing adequate concentrations of B. laterosporus spores. Toxicity significantly decreased after spore administration to birds was interrupted. When poultry diet contained 1010 spores/g, mortality of flies reared on feces exceeded 80%. The use of B. lateroporus spores as a feed additive in poultry production systems fostering a more integrated approach to farming is discussed
HOOKING TRAIL-R2 TO ¿EDUCATE¿ IMMUNE SYSTEM TO RECOGNIZE CANCER CELLS
Use of recombinant human tumor necrosis factor (TNF) related apoptosis inducing ligand (rhTRAIL) or TRAIL-receptors agonistic monoclonal antibodies (mAbs) promotes apoptosis in most cancer cells preserving normal cells. Furthermore, TRAIL-R2, one of the receptor that can trigger cell apoptotic machinery, is expressed at higher levels in tumor tissue as compared to normal tissues. Agonistic mAbs could mimic the tumor killing properties of rhTRAIL, with the advantage to have a prolonged half-life in vivo and to avoid binding of decoy TRAIL-receptors unable to transmit apoptotic signals. Although mAbs have proven to be highly effective, their use still unsolved the problem of TRAIL-resistance that some tumor cells are able to develop. To increase the anti-tumor activity of some mAbs, in last decades, bispecific antibodies (BsAbs) able to redirect cytotoxic activity of tumor resident/ circulating T cells against tumor cells in an MHC-independent fashion have been developed.
In this study, we isolated a BsAb able to bind the CD3, invariant component of the T-cell receptor, and TRAIL-R2. Among the different isolated BsAbs, one in particular presented good thermodynamic characteristics and showed a very good stability even after 2 years its purification. The BsAb was biochemically and functionally well characterized and the production method was optimized. We demonstrated that the BsAb could act with two mechanisms: retargeting T-cells to lyse tumor cells when acting as BsAb and activating apoptotic pathway by triggering TRAIL-R2 when acting as agonistic mAb. T-cell activation was confirmed by up-regulation of CD69 and CD25 and by production of inflammatory cytokines without off target toxicity. In vitro we demonstrated that, after BsAb-mediated retargeting, T cells were able to lyse tumors of different histotypes, like melanoma, breast and ovarian cancer while sparing normal cells
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