Multilobular morphology: the key for biphase multifunctional nanogels.

Nanogels play a leading role in controlled release systems because they possess high water retention capacity resulting in high loading capabilities, stability in biological fluids and biocompatibility. In this scenario, every tool that allows extending the nanogel properties and expanding their potential applications is of high interest in the field of biomedicine. This article aims to contribute to the development of multifunctional nanogels, based on the combination of two polymer phases in a multilobular morphology. The synthesized multilobed nanogels (mLNGs) presented a core of crosslinked poly(N-vinylcaprolactam) (PVCL) and a shell formed by 3-D distributed lobes of a low Tg copolymer. This particular multilobular morphology is able to exploit the synergetic contribution of both phases. While the PVCL-based core conferred its characteristic thermal response and the ability to load and release a cargo molecule, the low Tg lobes incorporated the capability of film formation. Moreover, the multilobular arrangement of NGs allows films to undergo unrestricted mass transfer. The development of mLNG morphology and the effect of synthesis parameters were deeply studied with the help of a previously developed mathematical model for the dynamic evolution of particle morphology. Finally, this study presents, for the first time, the synthesis of two-phase nanogels with multilobular morphology and underlines their potential as a candidate for controlled delivery platforms.

Cross-Contamination From Vial Caps for SEC Analysis Determined by MALDI-TOF Mass Spectrometry.

Cross-contamination from the polymeric material of the vial caps used in size exclusion chromatography (SEC) and high-performance liquid chromatography autosamplers in the low molar mass (LMM) range (<2000 Da) of polymer samples was demonstrated with the help of matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) analysis. It is shown that polyethylene (PE) caps, if exposed to either short or long periods in tetrahydrofuran solvent, might extract oligomers that contaminate the LMM end of the SEC chromatograms. On the other hand, polytetrafluoroethylene (PTFE)/silicone caps have shown to be inert if used properly; namely, the PTFE part in contact with the sample solution. However, care should be taken if accidentally the silicon part is exposed to the solution because silicone oligomer peaks have been detected by MALDI-TOF MS analysis that might mislead the results.

[Birth rates evolution in Spain. Birth trends in Spain from 1941 to 2010]. / Evolución de la natalidad en España. Análisis de la tendencia de los nacimientos entre 1941 y 2010.

OBJECTIVES: The aim of this study was to analyse trends of births in Spain and its Autonomous Communities (CCAA) over a 70 year period (1941-2010). METHODS: The crude birth rates per 1,000 inhabitants/year were calculated by CCAA using Joinpoint regression models. Change points in trend and annual percentage of change (APC) were identified. RESULTS: The distribution of 38,160,305 births between 1941 and 2010 shows important changes in trends both nationally and among the CCAA. There is a general pattern for the whole country, with 5 turning points being identified with changes in trend and annual percentage change (APC). Differences are also found among regions. CONCLUSION: The analysis of trends in birth rates and the annual rates of change should enable public health authorities to properly plan pediatric care resources in our country.

Automatic detection of wakefulness and rest intervals in actigraphic signals: a data-driven approach.

Actigraphy is an useful tool for evaluating the activity pattern of a subject; activity registries are usually processed by first splitting the signal into its wakefulness and rest intervals and then analyzing each one in isolation. Consequently, a preprocessing stage for such a splitting is needed. Several methods have been reported to this end but they rely on parameters and thresholds which are manually set based on previous knowledge of the signals or learned from training. This compromises the general applicability of this methods. In this paper we propose a new method in which thresholds are automatically set based solely on the specific registry to be analyzed. The method consists of two stages: (1) estimation of an initial classification mask by means of the expectation maximization algorithm and (2) estimation of a final refined mask through an iterative method which re-estimates both the mask and the classifier parameters at each iteration step. Results on real data show that our methodology outperforms those so far proposed and can be more effectively used to obtain derived sleep quality parameters from actigraphy registries.

[Circadian rhythm and time variations in out-hospital sudden cardiac arrest]. / Ritmo circadiano y variaciones temporales en el paro cardiaco súbito extrahospitalario.

OBJECTIVES: To analyze the chronobiological and time variations of out- hospital cardiac arrest (OHCA). DESIGN: A retrospective descriptive study was made. PATIENTS: All cases of OHCA of cardiac origin registered over 18 months in the database of the emergency medical service (EMS) of the Autonomous Community of Castilla y León (Spain) were evaluated. VARIABLES ANALYZED: Age, sex, recovery of spontaneous circulation (ROSC), first monitored rhythm (amenable / not amenable to defibrillation), alert site [(home, public place, primary care (PC) center], alerting person (family, witness, law enforcement member, PC center staff), alert time (0-8; 8-16; 16-24), emergency team activation time, care time and day of the week. Univariate analysis (chi-squared), variance, and nonparametric tests comparing the variables in three periods of 8 hours. Chronobiological analysis by fast Fourier transform and Cosinor testing. RESULTS: We studied 1286 cases reported between January 2007 and June 2008. Statistically significant differences were observed in terms of younger age, higher incidence in the victim's home, and greater frequency of family-cohabiting persons as witnesses in the period between 0 and 8 hours. Chronobiological analysis found daily rhythm (circadian) with acrophase at 11.16 h (p<0.001) and weekly rhythm (circaseptan) with acrophase on Wednesday (p<0.05). The median alert time-care time interval and emergency team activation time-care time were 11.7 min and 8.0 min, respectively, without differences between periods. CONCLUSIONS: We have demonstrated the presence of a daily rhythm of emergence of OHCA with a morning peak and a weekly rhythm with a peak on Wednesdays. These results can guide the planning of resources and improvements in response in certain time periods.