Raúl Durán Díaz

Tratamiento de la enfermedad hemorroidal mediante desarterialización y hemorroidopexia. Experiencia de varias unidades especializadas

INTRODUCTION Milligan-Morgan and Ferguson haemorrhoidectomy has been the gold standard treatment for symptomatic haemorrhoids for many years. However, escisional techniques are associated with a significant morbidity rate. In recent years, diverse techniques have been described in an attempt to decrease these complications. The guided transanal haemorrhoidal dearterialization THD) doppler is one of these techniques. We report our experience with this new technique. METHODS We performed a prospective study of 475 patients from 5 hospitals from the National Health System, in Spain. The majority of these patients suffered from third grade haemorrhoids (256 [56%]) and underwent THD. We analyse and compare preoperative and postoperative results as well as the homogeneity of the technique between hospitals. RESULTS Spinal anaesthesia was the most elected procedure by the anaesthetist (81.0%). Statistically significant differences were found between pre and postoperative symptoms (P=.03), with an overall improvement after surgery. The average hospitalization was 0.4±0.3 days. The mean number of days of oral analgesics was 8.8±2.7 days. The cumulative complication rate is 16%. CONCLUSION THD is a safe and easily reproducible procedure. Postoperative outcomes demonstrated a low rate of morbidity and recurrence together with early discharge; therefore, a rapid incorporation to daily activities was noted.

Influencia de la presión atmosférica sobre la incidencia de neumotórax espontáneo

BACKGROUND This study analyses the relationship between the incidence of idiopathic spontaneous pneumothorax (ISP) and atmospheric pressure (AP). METHODS A total of 288 cases of ISP were included, 229 men and 59 women. The AP of the day of diagnosis, of the 3 prior days and the monthly average was registered. The association between the incidence of ISP and AP was analyzed by calculating standardized incidence ratio (SIR) and Poisson regression. RESULTS The AP on the day of admission (mean±standard deviation) (1,017.9±7 hectopascals [hPa]) was higher than the monthly average AP (1,016.9±4.1 hPa) (P=.005). There was a monthly distribution pattern of ISP with the highest incidence in the months of January, February and September and the lowest in April. When AP was less than 1,014 hPa, there were fewer cases registered than what would statistically have been expected (58/72 cases). In contrast, when the pressure was higher than 1,019 hPa, the registered cases were more than expected (109/82 cases) (SIR=1.25; 95% CI: 1.04 to 1.51). The risk of ISP increased 1.15 times (95% CI: 1.05 to 1.25, P=.001) for each hPa of AP, regardless of sex, age and monthly average AP. A dose-response relationship was observed, with progressive increases in risk (IRR=1.06 when the AP was 1,014-1016 hPa; 1.17 hPa when the AP was 1,016-1,019 hPa and 1.69 when AP was superior to 1,019 hPa) (P for trend=.089). CONCLUSION The AP is a risk factor for the onset of idiopathic spontaneous pneumothorax.

A Study on the Performance of Secure Elliptic Curves for Cryptographic Purposes

Elliptic Curve Cryptography (ECC) is a branch of public-key cryptography based on the arithmetic of elliptic curves. In the short life of ECC, most standards have proposed curves defined over prime finite fields satisfying the curve equation in the short Weierstrass form. However, some researchers have started to propose as a more secure alternative the use of Edwards and Montgomery elliptic curves, which could have an impact in current ECC deployments. This contribution evaluates the performance of the three types of elliptic curves using some of the examples provided by the initiative SafeCurves and a Java implementation developed by the authors, which allows us to offer some conclusions about this topic.

Relationship Between Parathormone Concentration During Surgery and the Post-Operative Outcome of Primary Hyperparathyroidism

Abstract Introduction The relationship between the intra-operative concentration of parathyroid hormone (IOPTH) and the long-term outcome of patients intervened due to primary hyperparathyroidism (PHPT). Patients and methods A prospective observational study was performed with 120 patients. Three determinations were made of PTH in blood: baseline, when the diseases gland was located, and 10minutes after its extirpation. The calcium, PTH and vitamin D (25-OH-D3) levels were measured during follow up. Results A decrease in IOPTH>50% was observed in 96 (80%) patients, and the postextirpation value returned to the normal range (Group I), in 18 (15%) a decrease of >50% but the final value remained higher than normal (Group II) and in 6 (5%) the decrease was .001). Conclusion The risk of persistent PHPT is higher when the IOPTH decreases more than 50% but still remains high.

A Proposal for Using a Cryptographic National Identity Card in Social Networks

The distinctive security features of the Spanish electronic national identity card allow us to propose the usage of this cryptographic smart card in an authentication framework that can be used during the registration and login phases of certain internet services, including popular social networks. Using this mechanism with NFC-capable devices, the identity and age of the potential user can be determined, allowing or denying the access to the service based on that information.

The Isomorphism of Polynomials Problem Applied to Multivariate Quadratic Cryptography

The threat quantum computing poses to traditional cryptosystems (such as RSA, elliptic-curve cryptosystems) has brought about the appearance of new systems resistant to it: among them, multivariate quadratic public-key ones. The security of the latter kind of cryptosystems is related to the isomorphism of polynomials (IP) problem. In this work, we study some aspects of the equivalence relation the IP problem induces over the set of quadratic polynomial maps and the determination of its equivalence classes. We contribute two results. First, we prove that when determining these classes, it suffices to consider the affine transformation on the left of the central vector of polynomials to be linear. Second, for a particular case, we determine an explicit system of invariants from which systems of equations whose solutions are the elements of an equivalence class can be derived.

Relación entre concentración intraoperatoria de parathormona y evolución postoperatoria del hiperparatiroidismo primario

INTRODUCTION The relationship between the intra-operative concentration of parathyroid hormone (IOPTH) and the long-term outcome of patients intervened due to primary hyperparathyroidism (PHPT). PATIENTS AND METHODS A prospective observational study was performed with 120 patients. Three determinations were made of PTH in blood: baseline, when the diseases gland was located, and 10 minutes after its extirpation. The calcium, PTH and vitamin D (25-OH-D3) levels were measured during follow up. RESULTS A decrease in IOPTH > 50% was observed in 96 (80%) patients, and the post-extirpation value returned to the normal range (Group I), in 18 (15%) a decrease of > 50% but the final value remained higher than normal (Group II) and in 6 (5%) the decrease was<50% (Group III). Persistent PHPT was detected during follow up in 6 patients (5%): one in Group I (1%), 3 (16.7%) in II and 2 (33.3%) in group III (P<.001). The risk of persistent PHPT was higher in Group II (odds ratio: 19; 95% CI: 1.85-194) and in Group III (odds ratio: 47; 95% CI: 3.53-639). There were no cases of recurrent PHPT. A normal calcium with an increased PTH was detected in 20 patients of Group I (20.8%), 11 (61.1%) in II and 3 (50%) in III (P<.001). These patients had a lower concentration of post-operative vitamin D (17 ng/ml, range: 24; compared to 28 ng/ml, range: 21) (P=.008) and higher frequency of hypovitaminosis D (70.6% compared to 26.2%) (P>.001). CONCLUSION The risk of persistent PHPT is higher when the IOPTH decreases more than 50% but still remains high.

Computación en Grid: una solución asequible para las Simulaciones Medioambientales

This paper presents grid computing as a non-expensive and affordable option, from the point of view of application development, to leverage high performance computing using environmental simulation models. The proposed method allows the aggregation of resources provided by different organizations, thus allowing a substantial increase in the return of investments. Numerical computing solutions reducing the high communications load inherent to distributed systems are also shown.