A nonlinear approach to NN interactions using self-interacting meson fields

Motivated by the success of models based on chiral symmetry in NN interactions we investigate self-interacting scalar, pseudoscalar and vector meson fields and their impact for NN forces. We parametrize the corresponding nonlinear field equations and get analytic wavelike solutions. A probability amplitude for the propagation of particle states is calculated and applied in the framework of a boson-exchange NN potential. Using a proper normalization of the meson fields makes all self-scattering amplitudes finite. The same normalization is able to substitute for the phenomenological form factors used in conventional boson exchange potentials and thus yields an phenomenological understanding of this part of the NN interaction. We find an empirical scaling law which relates the meson self-interaction couplings to the pion mass and self-interaction coupling constant. Our model yields np phase shifts comparable to the Bonn B potential results and deuteron properties, in excellent agreement with experimental data.Comment: Reviewed version, 25 pages REVTeX, more info at http://i04ktha.desy.d

Towards automated composition of convergent services: A survey

A convergent service is defined as a service that exploits the convergence of communication networks and at the same time takes advantage of features of the Web. Nowadays, building up a convergent service is not trivial, because although there are significant approaches that aim to automate the service composition at different levels in the Web and Telecom domains, selecting the most appropriate approach for specific case studies is complex due to the big amount of involved information and the lack of technical considerations. Thus, in this paper, we identify the relevant phases for convergent service composition and explore the existing approaches and their associated technologies for automating each phase. For each technology, the maturity and results are analysed, as well as the elements that must be considered prior to their application in real scenarios. Furthermore, we provide research directions related to the convergent service composition phases

Local realizations of contact interactions in two- and three-body problems

Mathematically rigorous theory of the two-body contact interaction in three dimension is reviewed. Local potential realizations of this proper contact interaction are given in terms of Poschl-Teller, exponential and square-well potentials. Three body calculation is carried out for the halo nucleus 11Li using adequately represented contact interaction.Comment: submitted to Phys. Rev.

Home parenteral nutrition (HPN) registry in spain for the years 2007, 2008 and 2009 (Nadya-SENPE group)

Objetivo: Comunicar los datos del registro de Nutrición Parenteral Domiciliaria (NPD) del grupo de trabajo NADYA-SENPE de los años 2007, 2008 y 2009. Material y métodos: Recopilación de los datos del registro “on-line” introducidos por las Unidades responsables del seguimiento de la NPD desde el 1 de enero de 2007 al 31 de diciembre de 2009 dividido por años naturales. Resultados: Año 2007: Se registraron 133 pacientes con NPD (61 hombres y 72 mujeres), de 21 hospitales. La edad media de los 119 pacientes mayores de 13 años fue de 53,7 ± 14,9 años, y de 3,6 ± 3,6 años la de los 14 pacientes que no los superaban. La patología más frecuente fue la neoplasia (24%) seguida de las alteraciones de la motilidad intestinal y la enteritis posradiación (ambas 14%). En el 43% de los casos el motivo de indicación fue el síndrome de intestino corto, seguido de malabsorción (27%) y obstrucción intestinal (23%). Los catéteres más utilizados fueron los tunelizados (69%) y los reservorios subcutáneos (27%). Las complicaciones mas frecuentes fueron las sépticas relacionadas con el catéter con una tasa de 0,92 infecciones por cada mil días de NPD. La duración de la NPD fue superior a los dos años en el 50% de los casos. Al acabar el año seguía en activo el 71,4% de los pacientes; la muerte fue la principal causa de la finalización de la NPD (57,5%). El 26% de los pacientes se consideraron candidatos al trasplante intestinal. Año 2008: Se registraron 143 pacientes con NPD (62 hombres y 81mujeres), de 24 hospitales. La edad media de los 133 pacientes mayores de 13 años fue de 54,7 ± 13,9 años, y de 3,7 ± 0,6 años la de los 10 pacientes que no los superaban. La patología más frecuente fue la neoplasia (20%) seguida de la enteritis rádica (14%) y las alteraciones de la motilidad intestinal (13%). En el 44% de los casos el motivo de indicación fue el síndrome de intestino corto, seguido de malabsorción (28%) y obstrucción Nutriintestinal (20%). Los catéteres más utilizados fueron los tunelizados (60%) y los reservorios subcutáneos (29%). Las complicaciones mas frecuentes fueron las sépticas relacionadas con el catéter con una tasa de 0,50 infecciones por cada mil días de NPD. La duración de la NPD fue superior a los dos años en el 67% de los casos. Al acabar el año seguía en activo el 71,6% de los pacientes; la muerte fue la principal causa de la finalización de la NPD (52,4%). El 29% de los pacientes se consideraron candidatos al trasplante intestinal. Año 2009: Se registraron 158 pacientes con NPD (62 hombres y 96 mujeres), de 24 hospitales. La edad media de los 149 pacientes mayores de 13 años fue de 55,2 ± 13,0 años. La patología más frecuente fue la neoplasia (25%) seguida de la enteritis rádica (12%) y las alteraciones de la motilidad intestinal (11%). En el 42% de los casos el motivo de indicación fue el síndrome de intestino corto, seguido de malabsorción y obstrucción intestinal (ambas 23%). Los catéteres más utilizados fueron los tunelizados (60%) y los reservorios subcutáneos (36%). Las complicaciones mas frecuentes fueron las sépticas relacionadas con el catéter con una tasa de 0,67 infecciones por cada mil días de NPD. La duración de la NPD fue superior a los dos años en el 58% de los casos. Al acabar el año seguía en activo el 79,2% de los pacientes; el paso a alimentación oral fue la principal causa de la finalización de la NPD (48%). El 23% de los pacientes se consideraron candidatos a trasplante intestinal. Conclusiones: Se observa un aumento progresivo de los pacientes registrados respecto a años anteriores con una prevalencia muy variable según comunidades autónomas. La principal patología sigue siendo la neoplasia, que ocupa el primer lugar desde 2003. Se aprecia una disminución de las complicaciones sépticas relacionadas con el catéter en los dos últimos años, siendo la tasa de 2008 la más baja desde la creación del registroObjective: To report the data of the Home Parenteral Nutrition (HPN) registry of the NADYA-SENPE working group for the years 2007, 2008 and 2009. Methodology: We compiled the data from the on-line registry introduced by the responsible Units for the monitoring of HPN from January 1st 2007 to December 31st 2009. Included fields were: age, sex, diagnosis and reason for HPN, access path, complications, beginning and end dates, complementary oral or enteral nutrition, activity level, autonomy degree, product and fungible material supply, withdrawal reason and intestinal transplant indication. Results: 2007: 133 patients with HPN were registered (61 males and 72 females), belonging to 21 hospitals. Average age for the 119 patients older than 13 years old was 53.7 ± 14.9 years, and 3.6 ± 3.6 y. for the 14 patients under 14 years old. Most frequent pathology was neoplasm (24%), followed by intestinal motility disorders and actinic enteritis (14% both). The reason for HPN provision was short bowel syndrome (43%), malabsorption (27%), and intestinal obstruction (23%). Tunnelled catheters were mostly used (69%), followed by implanted port-catheters (27%). Catheter related infections were the most frequent complications, with a rate of 0.92 episodes/103 HPN days. HPN was provided for more than two years in 50% of the cases. By the end of 2007, 71.4% of the patients remained active; exitus was the most frequent reason to end HPN (57.5%). 26% of the patients were eligible for intestinal transplant. 2008: 143 patients with HPN were registered (62 males and 81 females), belonging to 24 hospitals. Average age for the 133 patients older than 13 years old was 54.7 ± 13.9 years, and 3.7 ± 0.6 y. for the 10 patients under 14 years old. Most frequent pathology was neoplasm (20%), followed by actinic enteritis (14%) and intestinal motility disorders (13% ). The reason for HPN provision was short bowel syndrome (44%), malabsorption (28%), and intestinal obstruction (20%). Tunnelled catheters were mostly used (60%), followed by implanted port-catheters (29%). Catheter related infections were the most frequent complications, with a rate of 0.50 episodes/103 HPN days. HPN was provided for more than two years in 67% of the cases. By the end of 2008, 71.6% of the patients remained active; exitus was the most frequent reason to end HPN (52.4%). 29% of the patients were eligible for intestinal transplant. 2009: 158 patients with HPN were registered (62 males and 96 females), belonging to 24 hospitals. Average age for the 149 patients older than 13 years old was 55.2 ± 13.0 years. Most frequent pathology was neoplasm (25%), followed by actinic enteritis (12%) and intestinal motility disorders (11%). The reason for HPN provision was short bowel syndrome (42%), malabsorption, and intestinal obstruction (23% both). Tunnelled catheters were mostly used (60%), followed by implanted port-catheters (36%). Catheter related infections were the most frequent complications, with a rate of 0.67 episodes/103 HPN days. HPN was provided for more than two years in 58% of the cases. By the end of 2009, 79.2% of the patients remained active; full oral nutrition was the most frequent reason to end HPN (48%). 23% of the patients were eligible for intestinal transplant. Conclusions: We observe an increase in registered patients with respect to previous years, with a very different prevalence among regions. Neoplasia remains as the main pathology since 2003. We observe a decrease in catheter-related infections in the last two years, being the 2008 rate the smallest since the register’s beginning

Enzyme-powered gated mesoporous silica nanomotors for on-command intracellular payload delivery

\u3cp\u3eThe introduction of stimuli-responsive cargo release capabilities on self-propelled micro- A nd nanomotors holds enormous potential in a number of applications in the biomedical field. Herein, we report the preparation of mesoporous silica nanoparticles gated with pH-responsive supramolecular nanovalves and equipped with urease enzymes which act as chemical engines to power the nanomotors. The nanoparticles are loaded with different cargo molecules ([Ru(bpy)\u3csub\u3e3\u3c/sub\u3e]Cl\u3csub\u3e2\u3c/sub\u3e (bpy = 2,2′-bipyridine) or doxorubicin), grafted with benzimidazole groups on the outer surface, and capped by the formation of inclusion complexes between benzimidazole and cyclodextrin-modified urease. The nanomotor exhibits enhanced Brownian motion in the presence of urea. Moreover, no cargo is released at neutral pH, even in the presence of the biofuel urea, due to the blockage of the pores by the bulky benzimidazole:cyclodextrin-urease caps. Cargo delivery is only triggered on-command at acidic pH due to the protonation of benzimidazole groups, the dethreading of the supramolecular nanovalves, and the subsequent uncapping of the nanoparticles. Studies with HeLa cells indicate that the presence of biofuel urea enhances nanoparticle internalization and both [Ru(bpy)\u3csub\u3e3\u3c/sub\u3e]Cl\u3csub\u3e2\u3c/sub\u3e or doxorubicin intracellular release due to the acidity of lysosomal compartments. Gated enzyme-powered nanomotors shown here display some of the requirements for ideal drug delivery carriers such as the capacity to self-propel and the ability to sense the environment and deliver the payload on demand in response to predefined stimuli.\u3c/p\u3