Unambiguous Intracellular Localization and Quantification of a Potent Iridium Anticancer Compound by Correlative 3D Cryo X-Ray Imaging

The iridium half-sandwich complex [Ir(η⁵:κ¹-C₅Me₄CH₂py)(2-phenylpyridine)]PF₆ is highly cytotoxic: 15–250× more potent than clinically used cisplatin in several cancer cell lines. We have developed a correlative 3D cryo X-ray imaging approach to specifically localize and quantify iridium within the whole hydrated cell at nanometer resolution. By means of cryo soft X-ray tomography (cryo-SXT), which provides the cellular ultrastructure at 50 nm resolution, and cryo hard X-ray fluorescence tomography (cryo-XRF), which provides the elemental sensitivity with a 70 nm step size, we have located the iridium anticancer agent exclusively in the mitochondria. Our methodology provides unique information on the intracellular fate of the metallodrug, without chemical fixation, labeling, or mechanical manipulation of the cells. This cryo-3D correlative imaging method can be applied to a number of biochemical processes for specific elemental localization within the native cellular landscape.     

Sensitivity analysis of efficiency and Malmquist productivity indices: An application to Spanish savings banks

Hypothesis testing and statistical precision in the context of non-parametric efficiency and productivity measurement have been investigated since the early 1990s. Recent contributions focus on this matter through the use of resampling methods—i.e., bootstrapping techniques. However, empirical evidence is still practically non-existent. This gap is more noticeable in the case of banking efficiency studies, where the literature is immense. In this work, we explore productivity growth and productive efficiency for Spanish savings banks over the (initial) post-deregulation period 1992–1998 using Data Envelopment Analysis (DEA) and bootstrapping techniques. Results show that productivity growth has occurred, mainly due to improvement in production possibilities, and that mean efficiency has remained fairly constant over time. The bootstrap analysis yields further evidence, as for many firms productivity growth, or decline, is not statistically significant. With regard to efficiency measurement, the bootstrap reveals that the disparities in the original efficiency scores of some firms are lessened to a great extent.     

QGP tomography with photon tagged jets in ALICE

γ+jet events provide a tomographic measurement of the medium formed in heavy ion collisions at LHC energies.Tagging events with a well identified high p T direct photon and measuring the correlation distribution of hadrons emitted oppositely to the photon in ALICE,allows us to determine,with a good approximation,both the jet fragmentation function and the back-to-back azimuthal alignment of the direct photon and the jet.Comparing these two observables measured in pp collisions with the ones measured in AA collisions will reveal the modifications of the jet structure induced by the medium formed in AA collisions and consequently will infer the medium properties.     

The effect of NaOH on the liquid-phase hydrodechlorination of dioxins over Pd/gamma-Al2O3

The effect of sodium hydroxide on the-liquid phase hydrodechlorination (LPHDC) of polychlorinated dibenzo- p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) over 2% Pd/gamma-Al 2O 3 was evaluated. Reactions were carried out using 2-propanol both as a hydrogen donor and as a solvent. Fresh and used catalyst samples were characterized by BET, hydrogen chemisorption, TEM/EDS, XPS, and TPR. When the reaction mixture contained no NaOH, active-phase leaching and Pd-C formation were observed even after 10 min of reaction. Therefore, sodium hydroxide appears to be required to maintain surface metal clusters on the support and avoid binding of carbon species to the active metal. On the other hand, excess NaOH in the reaction mixture led to deposition of organic and inorganic solid residues on the catalyst surface, blocking the active sites. Under the conditions of this study, the addition of 30 mg of NaOH maintained the basicity of the system and diminished deposition of solid residues on the catalyst samples, and almost 100% detoxification was reached after a 3 h reaction.     

Prediction in Markovian bulk arrival queues

This paper deals with the statistical analysis of bulk arrival queues from a Bayesian point of view. The focus is on prediction of the usual measures of performance of the system in equilibrium. Posterior predictive distribution of the number of customers in the system is obtained through its probability generating function. Posterior distribution of the waiting time, in the queue and in the system, of the first customer of an arriving group is expressed in terms of their Laplace and Laplace–Stieltjes transform. Discussion of numerical inversion of these transforms is addressed.     

Energetics of formation of TiGa3As4 and TiGa3P4 intermediate band materials

Using density functional theory quantum methods, total energy values and vibrational properties have been computed, and thermodynamic properties evaluated, for Ti-substituted GaAs and GaP, proposed as candidates for intermediate band photovoltaic cells. The calculations predict that the formation of these materials from the binary compounds implies an increase in total energy (that is ascribed largely to the change in coordination undergone by Ti, from six-fold to four-fold), and thus phase separation rather than mixed compound formation would be favored. However, the mentioned increase is not larger (for the arsenide case it is actually smaller) than that predicted for Mn-substituted GaAs, a material which has been experimentally made, and therefore the obtention of these Ti-substituted materials is expected to be feasible as well. Vibrational and disorder entropy contributions to the formation free energy of the ternary compounds have been also computed; they compensate partially for the total energy increase, and indicate that the thermodynamic feasibility of the materials synthesis improves for low Ti concentrations and high temperature conditions.     

First principles calculations of electronic structures and metal mobility of Na(x)Si(46) and Na(x)Si(34) clathrates

Energetics, geometry, electronic band structures, and charge transfer for Na(x)Si(46) and Na(x)Si(34) clathrates with different degrees of cavity filling by sodium, and the mobility of the Na atom inside the different cavities are studied using first principles density functional calculations within the generalized gradient approximation. The stabilization of the clathrate lattice and the cell volume variation upon the inclusion of Na (which appears to move easily in the larger cavities of Na(x)Si(34), thus justifying the experimental observations) are discussed in connection with the onset of the repulsion between Na and Si for distances shorter than approximately 3.4 A. For all degrees of filling of the different cavities examined we find that the electron population of the s orbitals in the partially ionized Na atoms increases with a decrease in the size of the cavity, and that the Na states contribute significantly to the density of states at the Fermi level and thus influence the properties of these compounds.