From Nanorods to Nanowires of CdS Synthesized by a Solvothermal Method: Influence of the Morphology on the Photoactivity for Hydrogen Evolution from Water.

The effect of temperature and water/thiourea ratio on the growth, crystallinity and morphological characteristics of CdS nanostructures synthetized by a solvothermal method using ethylenediamine as solvent were studied. The temperature and water/thiourea ratio used in the synthesis determine the surface area, shape, length and degree of crystallinity of the CdS nanostructures obtained. Nanowires of high crystallinity and length were obtained when the solvothermal synthesis was performed at 190 °C, while nanorods with lower length and crystallinity were obtained as the solvothermal temperature decreased to 120 °C. The change in the water/thiourea ratio affects the crystallinity and length of the CdS nanostructures to a lesser extent than temperature. Nevertheless an increase in the water/thiourea ratio used during the solvothermal synthesis resulted in CdS nanorods with higher crystallinity, lower aspect ratio and lower specific surface area. Textural, structural and surface properties of the prepared CdS nanostructures were determined and related to the activity results in the production of hydrogen from aqueous solutions containing SO3(2-) + S(2-) under visible light.

Monitoring the practice of vascular surgery: findings from a national registry (1996-2011).

BACKGROUND: The goal of this article is to present for the first time to the international community the detailed findings and outcomes of the Spanish Vascular Registry (SVR) after 16 years of experience. METHODS: We examined the nationwide registry promoted by the Spanish Society of Angiology and Vascular Surgery (1996-2011). The changes in vascular surgical activity in Spain during the period of study were examined. We evaluated the number of services, medical specialists, consultations, admissions, and operations that occurred in Spain. We also assessed the trends in therapeutic activity and the medical and social impact of vascular pathology. RESULTS: A mean of 60 centers (range = 32-83) participated in the SVR (79.3 % of the total). In the last year of the study period, 94.3 % centers (100 % of teaching centers) participated. The mean number of activities per hospital per year was 5,298 consultations, 2,625 vascular explorations, 630 hospital admissions (61 % elective and 31 % emergency), and 742 surgical procedures. A total of 29,289 carotid stenosis procedures had been registered over 16 years. Both carotid endarterectomy (CEA) and carotid artery stenting (CAS) procedures have increased in frequency over time. In 2011, CAS constituted 19.3 % of all carotid procedures. A total of 31,703 abdominal aortic aneurysm (AAA) operations were registered during the study period. Surgery for ruptured AAA remained stable over time. Since its appearance in the year 2000, endovascular treatment (EVAR) increased steadily over time. Currently, EVAR represents about half of all AAA surgery (50.2 %). The total rate of in-hospital operative deaths was 1.1 %, but in-hospital mortality for open arterial surgery was 4 %. Mortality has decreased of late. CONCLUSIONS: The SVR has enabled us to understand the development and implementation of vascular surgery throughout Spain and to note the increased healthcare activity and the better overall results obtained as a consequence.

New testing procedures of a capacitive deionization reactor.

Currently, according to conventional charge-discharge profiles, energy consumed in charging Capacitive Deionization (CDI) systems is always a function of different parameters (current used for charging, capacitance and current employed for discharging) making it difficult to separate the effect of these parameters on CDI performance and energy efficiency. Thus, energy efficiencies are strongly influenced by the current in the preceding charge or discharge stage of the process. We find consistently that this phenomenon, which to our knowledge has not been addressed in previous CDI communications, is much more intense when different currents are applied for each of the charging and discharging cycles. The investigation reported here provides a mechanistic analysis of the operational aspects of CDI and develops a new procedure that allows for a precise evaluation of performance and energy efficiency. Furthermore, the model developed here allows one to separate charge and discharge cycles, and therefore contributes to the possibility of defining an operational mode for real-world devices in which effective separation of deionization and regeneration steps needs to be implemented. This method of analysis could be useful not only for CDI but also for other electrochemical systems such as in secondary batteries and supercapacitors where charge and discharge are typically employed.