405 research outputs found
TEM-184, a Novel TEM-Derived Extended-Spectrum beta-Lactamase with Enhanced Activity against Aztreonam
No full textTEM-184, a novel TEM-derived extended-spectrum beta-lactamase (ESBL), was isolated from an Escherichia coli ST354 clinical strain. Compared to TEM-1, TEM-184 contains the mutations Q6K, E104K, I127V, R164S, and M182T. Kinetic analysis of this enzyme revealed extended-spectrum activity against aztreonam in particular. TEM-184 was also susceptible to inhibitors, including clavulanic acid, tazobactam, and avibactam
A cross-correlation analysis of CMB lensing and radio galaxy maps
No full textAims. The goal of this work is to clarify the origin of the seemingly anomalously large clustering signal detected at large angular separation in the wide TGSS radio survey and, in so doing, to investigate the nature and the clustering properties of the sources that populate the radio sky in the [0.15, 1.4] GHz frequency range.
Methods. To achieve this goal, we cross-correlated the angular position of the radio sources in the TGSS and NVSS samples with the cosmic microwave background (CMB) lensing maps from the Planck satellite. A cross-correlation between two different tracers of the underlying mass density field has the advantage of being quite insensitive to possible systematic errors that may affect the two observables, provided that they are not correlated, which seems unlikely in our case. The cross-correlation analysis was performed in harmonic space and limited to relatively modest multipoles. These choices, together with that of binning the measured spectra, minimize the correlation among the errors in the measured spectra and allowed us to adopt the Gaussian hypothesis to perform the statistical analysis. Finally, we decided to consider the auto-angular power spectrum on top of the cross-spectrum since a joint analysis has the potential to improve the constraints on the radio source properties by lifting the degeneracy between the redshift distribution, N(z), and the bias evolution, b(z).
Results. The angular cross-correlation analysis does not present the power excess at large scales for TGSS and provides a TGSS–CMB lensing cross-spectrum that is in agreement with the one measured using the NVSS catalog. This result strongly suggests that the excess found in TGSS clustering analyses can be due to uncorrected systematic effects in the data. However, we considered several cross-spectra models that rely on physically motivated combinations of N(z) and b(z) prescriptions for the radio sources and find that they all underestimate the amplitude of the measured cross-spectra on the largest angular scales considered in our analysis, ∼10°. This result is robust to the various potential sources of systematic errors, both of observational and theoretical nature, that may affect our analysis, including the uncertainties in the N(z) model. Having assessed the robustness of the results to the choice of N(z), we repeated the analysis using simpler bias models specified by a single free parameter, bg, namely, the value of the effective bias of the radio sources at redshift zero. This improves the goodness of the fit, although not even the best model, which assumes a non-evolving bias, quite matches the amplitude of the cross-spectrum at small multipoles. Moreover, the best fitting bias parameter, bg = 2.53 ± 0.11, appears to be somewhat large considering that it represents the effective bias of a sample that is locally dominated by mildly clustered star-forming galaxies and Fanaroff-Riley class I sources. Interestingly, it is the addition of the angular auto-spectrum that favors the constant bias model over the evolving one.
Conclusions. The nature of the large cross-correlation signal between the radio sources and the CMB lensing maps found in our analysis at large angular scales is not clear. It probably indicates some limitation in the modeling of the radio sources, namely the relative abundance of the various populations, their clustering properties, and how these evolve with redshift. What our analysis does show is the importance of combining the auto-spectrum with the cross-spectrum, preferably obtained with unbiased tracers of the large-scale structure, such as CMB lensing, for answering these questions
L’unica possibilità per evitare il ricorso immediato ai controlimiti: un rinvio pregiudiziale che assomiglia a una diffida (nota a Corte cost., ord. n. 24/2017)
No full textSOMMARIO: 1. Premessa: gli scenari ipotizzati alla vigilia. – 2. Elementi di continuità e innovazioni nell’economia della ratio decidendi. – 3. Il definitivo abbandono del «dialogo indiretto»? Quando la «doppia pregiudizialità» incrocia i principi supremi. – 4. Dai controlimiti alla identity review? – 5. Un rinvio necessario per evitare il ricorso immediato ai controlimiti. – 6. L’art. 4 (2) TUE come «europeizzazione» dei controlimiti. Qualche riflessione conclusiva sulle prospettive della nuova pronuncia pregiudiziale
Concluding chapter – Bicameralism as a normative choice in the tension between its reform and its passing
No full textElezioni amministrative: con un occhio ai Comuni e due alla riforma elettorale. Una ulteriore spinta verso il proporzionale?
No full textSommario: 1. L’accelerazione verso una (necessaria) modifica delle leggi elettorali.2.Il (magro) antipasto delle amministrative.3.La composizione dell’offerta elettorale: quattro punti di osservazione per comprendere dove vanno i partiti (prima di vedere dove vanno gli elettori). 3.1Il Pd e “a sinistra del PD”. 3.2Il MoVimento 5 Stelle.3.3La coalizione di centrodestra.3.4Le formazioni centriste.4.Una riflessione conclusiva
Potent inhibitory activity of taniborbactam towards NDM-1 and NDM-1Q119X mutants, and in vitro activity of cefepime/taniborbactam against MBLs producing Enterobacterales
No full textObjective: This study aimed to investigate the in vitro activity of taniborbactam (VNRX-5133), a novel broad-spectrum bicyclic boronate, against NDM-1 and Q119E, Q119K, Q119C, Q119F, Q119V, and Q119Y NDM-1 variants, which showed an increased activity towards some β-lactams, including cefepime. Methods: Inhibition kinetic assays were spectrophotometrically performed using cefepime (50 μM) as the reporter substrate and 80 nM of each enzyme. Taniborbactam behaves as a competitive inhibitor towards NDM-1 and NDM-1 Q119 variants with lower Ki values (range 3–16 nM). The phenotypic profile was assessed in both Enterobacterales clinical isolates and engineered Escherichia coli BL21(DE3) strains by conventional broth microdilution procedures according to the Clinical and Laboratory Standards Institute (CLSI). Results: Taniborbactam at a fixed concentration of 4 mg/L was able to restore activity of cefepime in 24 of 26 Enterobacterales clinical isolates harbouring metallo-β-lactamases with MIC50/MIC90 values of 14 mg/L. Cefepime MICs were drastically reduced in all clinical isolates and in NDM-1 and Q119X producing Escherichia coli BL21(DE3). Taniborbactam was unable to restore susceptibility to cefepime in two IMP variants producing clinical isolates. Conclusion: The inhibition level of NDM enzymes provided by taniborbactam protects the antibacterial activity of cefepime from this important metallo-β-lactamase
Catheter-ocking device-assisted external ventricular drain placement: a new surgical technique preventing intracranial drain displacement-technical note with preliminary single-center results
No full textBackground: External ventricular drain (EVD) placement is frequently performed in neurosurgical patients to divert cerebrospinal fluid (CSF) and monitor intracranial pressure. The traditional practice is the tunneled EVD technique performed in the operating room. EVD insertion through a bolt in intensive care units has also been reported. We describe here the usage of a novel technique, the catheter-locking device-assisted EVD placement, reporting our preliminary, observational single-center results. Methods: From January to October 2021, 15 patients underwent a catheter-locking device-assisted EVD placement at our institute. For each of these patients, the following data were evaluated: (1) demographics, (2) etiology, (3) clinical presentation, (4) EVD complications, and (5) final clinical outcomes. Results: Median age of our population was 64 years, with a female/male ratio of 2:1. Average Glasgow Coma Scale score on admission was 8. Each patient maintained the drainage for an average time of 14 days. None of the patients suffered from postoperative intracerebral hemorrhage, CSF leakage, catheter migration, or discontinuation of the drainage system; none developed signs of infection. Nine patients required a permanent CSF diversion system. Outcome was good in 14 patients. One patient died for the underlying disease. Conclusions: The catheter-locking device-assisted EVD placement appears to be a safe and accurate alternative to both the standard tunneled and the bolt-assisted EVD insertion techniques. The use of this procedure may significantly reduce the incidence of the commonest EVD complications, though further investigation is required
Terahertz Absorption change in Photosynthetic Reaction Center upon photoactivation
No full textPhotosynthetic reaction center is a membrane protein
which plays an important role in converting solar energy into
chemical energy. Upon continuous illumination a charge
separation occurs within the protein which is stable for
several seconds [1]. The stability of this state is very
important to protect the protein against the release of excess
heat and an instable radical due to charge recombination.
Absorption of terahertz radiation corresponds to the
excitation of large vibrations in the protein and is thus suitable
for studying its different dynamical states. Here we recorded
terahertz absorption spectra of the dark and illuminated state
of reaction centre from the purple membrane bacteria
Rhodobacter sphaeroides
to investigate the stability of the
charge separated state. The difference terahertz absorption
spectra show an overall increase in absorption for the
illuminated state in the 30-130 cm
-1
spectral region. By
simulating and fitting a theoretical terahertz spectrum of
reaction center from an elastic network model we were able to
investigate the effect of charge separation and conformational
changes within the interaction network. We find that a more
loose interaction network in the photoactivated state of the
protein is the most probable cause of the absorption increase
Italy and the EU
No full textSummary: A) THE ITALIAN CONTRIBUTION TO EUROPEAN INTEGRATION. – 1. Foundations: The Ventotene Manifesto and beyond. – 2. Instruments: Symmetries Between Incidental Proceedings and Preliminary Reference. – 3. Theories: Legal Pluralism, Dualism, Counterlimits. – 4. Experiences: Constructive Judicial Dialogue with the ECJ. – B) EUROPEAN DRIVERS IN THE INNOVATION OF THE ITALIAN LEGAL ORDER. – 1. The Institutional System. – 1.a. The Europeanisation of Parliamentary Functions. – 1.b. The European Role of the President of the Republic. – 1.c. The Presidentialisation of the Government. – 1.d. European Regional Blindness vs. the Federalisation Process. – 2. Sources of Law. – 2.a. The Slow Entrance of the EU into the Text of the Constitution. – 2.b. A New Concept of Legality. – 2.c. The Annual European Session. – 2.d. Support to the Expansion of Delegated Legislation. – 3. Protection of Fundamental Rights. – 3.a. The Incorporation of the ECHR. – 3.b. Competing Systems of Fundamental Rights Protection. – 3.c. The Decision not to Ratify Protocol No. 16 ECHR
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