Current-Driven Conformational Changes, Charging and Negative Differential Resistance in Molecular Wires

We introduce a theoretical approach based on scattering theory and total energy methods that treats transport non-linearities, conformational changes and charging effects in molecular wires in a unified way. We apply this approach to molecular wires consisting of chain molecules with different electronic and structural properties bonded to metal contacts. We show that non-linear transport in all of these systems can be understood in terms of a single physical mechanism and predict that negative differential resistance at high bias should be a generic property of such molecular wires.Comment: 9 pages, 4 figure

Aplicación de las Nuevas Tecnologías GPS-GPRS para el estudio del comportamiento y mejora de la producción de la raza de lidia

La dehesa es un ecosistema agroforestal único que aúna un óptimo rendimiento económico con una menor incidencia en el medio. En la Península Ibérica hay unas 500.000 hectáreas de dehesas concentradas en Andalucía, Castilla y León, Extremadura, Castilla La Mancha y Madrid. La raza de Lidia es, dentro de las razas autóctonas, por su rusticidad y adaptación, una de las que mejor aprovechan y conservan la dehesa. Las condiciones de cría en grandes fincas (400-500 hectáreas de media), el espacio por cabeza (entre una y seis hectáreas por animal), la movilidad que le da su menor tamaño con respecto a otras razas y su crecimiento en libertad con mínima presencia humana la ha hecho indispensables para el mantenimiento del ecosistema de la dehesa. Con este trabajo pretendemos aplicar una tecnología innovadora como es el GPS-GPRS a la monitorización de la etología del ganado de la raza de Lidia durante todos los periodos de su vida y especialmente en aquellos momentos en los que el animal se ve sometido a diferentes prácticas de manejo. Para ello, se implementará la tecnología de GPS que permite el posicionamiento relativo de un objetivo mediante la captación de la señal de diferentes satélites específicos, lo que proporcionará información precisa sobre: el desplazamiento del ganado en un periodo determinado, las distancias recorridas, el territorio pastoreado, las áreas más querenciosas, su ritmo circadiano, las pautas de comportamiento, etc. Así mismo, el dispositivo incorporará sensores de parámetros biológicos como la temperatura ó el ritmo cardíaco, etc. La implementación de este sistema permitirá, a través del posicionamiento, realizar la óptima gestión de los recursos pastables de la dehesa, permitiendo ahorrar costes en alimentación, infraestructuras y personal, y ofrecer, en un futuro cercano, una atractiva herramienta al ganadero para realizar el control remoto de sus reses

Bariatric surgery and diabetes remission: Sleeve gastrectomy or mini-gastric bypass?

AIM: To investigate the weight loss and glycemic control status [blood glucose, hemoglobin A1c (HbA1c) and hypoglycaemic treatment]. METHODS: The primary risk factor for type 2 diabetes is obesity, and 90% of all patients with type 2 diabetes are overweight or obese. Although a remarkable effect of bariatric surgery is the profound and durable resolution of type 2 diabetes clinical manifestations, little is known about the difference among various weight loss surgical procedures on diabetes remission. Data from patients referred during a 3-year period (from January 2009 to December 2011) to the University of Naples "Federico II" diagnosed with obesity and diabetes were retrieved from a prospective database. The patients were split into two groups according to the surgical intervention performed [sleeve gastrectomy (SG) and mini-gastric bypass (MGB)]. Weight loss and glycemic control status (blood glucose, HbA1c and hypoglycaemic treatment) were evaluated. RESULTS: A total of 53 subjects who underwent sleeve gastrectomy or mini-gastric bypass for obesity and diabetes were screened for the inclusion in this study. Of these, 4 subjects were excluded because of surgical complications, 7 subjects were omitted because young surgeons conducted the operations and 11 subjects were removed because of the lack of follow-up. Thirty-one obese patients were recruited for this study. A total of 15 subjects underwent SG (48.4%), and 16 underwent MGB (51.6%). After adjusting for various clinical and demographic characteristics in a multivariate logistic regression analysis, high hemoglobin A1c was determined to be a negative predictor of diabetes remission at 12 mo (OR = 0.366, 95%CI: 0.152-0.884). Using the same regression model, MGB showed a clear trend toward higher diabetes remission rates relative to SG (OR = 3.780, 95%CI: 0.961-14.872). CONCLUSION: Although our results are encouraging regarding the effectiveness of mini-gastric bypass on diabetes remission, further studies are needed to provide definitive conclusions in selecting the ideal procedure for diabetes remission

Decoherence in elastic and polaronic transport via discrete quantum states

Here we study the effect of decoherence on elastic and polaronic transport via discrete quantum states. The calculations are performed with the help of nonperturbative computational scheme, based on the Green's function theory within the framework of polaron transformation (GFT-PT), where the many-body electron-phonon interaction problem is mapped exactly into a single-electron multi-channel scattering problem. In particular, the influence of dephasing and relaxation processes on the shape of the electrical current and shot noise curves is discussed in detail under the linear and nonlinear transport conditions.Comment: 11 pages, 3 figure

Cytosolic phosphorylated EGFR is predictive of recurrence in early stage penile cancer patients: A retropective study

Background: Penile cancer (PC) is a rare tumor, and therapeutic options are limited for this disease, with an overall 5-year overall survival around 65-70%. Adjuvant therapy is not recommended for patients with N0-1 disease, despite up to 60% of these patients will die within 5 years from diagnosis. Methods: Medical records of all patients who underwent radical surgery at University Federico II of Naples and at National Tumor Institute "Pascale" of Naples for early squamous cell carcinoma of the penis from January, 2000 to December, 2011 were retrieved. Paraffin wax embedded tissue specimens were retrieved from the pathology archives of the participating Institutions for all patients. Expression of p-EGFR, EGFR and positivity to HPV were evaluated along with other histological variables of interest. Demographic data of eligible patients were retrieved along with clinical characteristics such as type of surgical operation, time of follow up, time of recurrence, overall survival. A multivariable model was constructed using a forward stepwise selection procedure. Results: Thirty eligible patients were identified. All patients were positive for EGFR by immunohistochemistry, while 13 and 16 were respectively positive for nuclear and cytosolic p-EGFR. No EGFR amplification was detected by FISH. Eight patients were positive for high-risk HPV by ISH. On univariable analysis, corpora cavernosa infiltration (OR 7.8; 95% CI = 0,8 to 75,6; P = 0,039) and positivity for cytosolic p-EGFR (OR 7.6; 95% CI = 1.49 to 50; P = 0.009) were predictive for recurrence, while only positivity for cytosolic p-EGFR (HR = 9.0; 95% CI 1.0-100; P = 0,0116) was prognostic for poor survival. Conclusion: It is of primary importance to identify patients with N0-1 disease who are at increased risk of recurrence, as they do not normally receive any adjuvant therapy. Expression of p-EGFR was found in this series to be strongly related to increase risk of recurrence and shorter overall survival. This finding is consistent with the role of p-EGFR in other solid malignancies. Integration of p-EGFR with classic prognostic factors and other histology markers should be pursued to establish optimal adjuvant therapy for N0-1 PC patients

Transport via a quantum shuttle

Published versio

Captive-born collared peccary (Pecari tajacu, Tayassuidae) fails to discriminate between predator and non-predator models

Captive animals may lose the ability to recognize their natural predators, making conservation programs more susceptible to failure if such animals are released into the wild. Collared peccaries are American tayassuids that are vulnerable to local extinction in certain areas, and conservation programs are being conducted. Captive-born peccaries are intended for release into the wild in Minas Gerais state, southeastern Brazil. In this study, we tested the ability of two groups of captive-born collared peccaries to recognize their predators and if they were habituated to humans. Recognition tests were performed using models of predators (canids and felids) and non-predators animals, as well as control objects, such as a plastic chair; a human was also presented to the peccaries, and tested as a separate stimulus. Anti-predator defensive responses such as fleeing and threatening displayswere not observed in response to predator models. Predator detection behaviors both from visual and olfactory cues were displayed, although they were not specifically targeted at predator models. These results indicate that collared peccaries were unable to recognize model predators. Habituation effects, particularly on anti-predator behaviors, were observed both with a 1-h model presentation and across testing days. Behavioral responses to humans did not differ from those to other models. Thus, if these animals were to be released into the wild, they should undergo anti-predator training sessions to enhance their chances of survival