Hybrid pH-Responsive Au@p4VP Microgels as Platform for Selective SERS Analysis

We present the synthesis a of pH-responsive core@shell hybrid microgel. This colloidal system is formed by a 55 nm Au core individually covered by a polymeric pH-sensitive shell of poly(4-vinylpyridine), that we denote as Au@p4VP. Initially, we control the microgel thickness from 51 to 10 nm, and we confirm the pH- responsive capability of Au@p4VP by DLS measurements, showing a swelling degree, which depends on the pH of the media and the crosslinker density within the polymer network. We also prove the hybrid structure by plotting the UV-vis spectra at different pH values, showing a surface plasmon band displacement in function of pH. Thus, at acidic pH the microgel swells due to the electrostatic repulsion created into the polymer matrix, while at high pH, the microgel structure collapses because of the reduction in the electrostatic repulsion and the increment of the hydrophobic interactions. This capability is exploited to introduce doxorubicin molecules into the microgel network which are detected by surface- enhanced Raman spectroscopy (SERS). After increasing the pH of the solution, the captured molecules are brought in close proximity to the surface of the metallic core, enhancing its detection by SERS.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The impact of unilateral divorce on crime

In this paper, we evaluate the impact of unilateral divorce on crime. First, using crime rates from the FBI´s Uniform Crime Report program for the period 1965-1998 and differences in the timing in the introduction of the reform, we find that unilateral divorce has a positive impact on violent crime rates, with an 8% to 12% average increase for the period under consideration. Second, arrest data not only confirms the findings of a positive impact on violent crime but also shows that this impact is concentrated among those age groups (15 to 24) that are more likely to engage in these type of offenses. Specifically, for the age group 15-19, we observe an average impact over the period under analysis of 40% and 36% for murder and aggravated assault arrest rates, respectively. Disaggregating total arrest rates by race, we find that the effects are driven by the Black sub-sample. Third, using the age at the time of the divorce law reform as a second source of variation to analyze age-specific arrest rates we confirm the positive impact on the different types of violent crime as well as a positive impact for property crime rates, controlling for all confounding factors that may operate at the state-year, state age or age-year level. The results for murder arrests and for homicide rates (Supplemental Homicide Report) for the 15-24 age groups are robust with respect to specifications and specifically those that include year-state and year-age dummies. The magnitude goes from 15% to 40% depending on the specification and the age at the time of the reform

Bath-induced correlations in an infinite-dimensional Hilbert space

Quantum correlations between two free spinless dissipative distinguishable particles (interacting with a thermal bath) are studied analytically using the quantum master equation and tools of quantum information. Bath-induced coherence and correlations in an infinite-dimensional Hilbert space are shown. We show that for temperature T > 0 the time-evolution of the reduced density matrix cannot be written as the direct product of two independent particles. We have found a time-scale that characterizes the time when the bath-induced coherence is maximum before being wiped out by dissipation (purity, relative entropy, spatial dispersion, and mirror correlations are studied). The Wigner function associated to the Wannier lattice (where the dissipative quantum walks move) is studied as an indirect measure of the induced correlations among particles. We have supported the quantum character of the correlations by analyzing the geometric quantum discord.Comment: 13 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:1512.0870