Optical design optimization for improved lamp-reflector units in high-flux solar simulators.

High flux solar simulators are artificial solar facilities developed to imitate the on-sun operations of concentrating solar power technologies but under a well-controlled lab-scale environment. We report the optical enhancement of different high flux solar simulators for solar thermal and thermochemical applications. The solar simulator enhancement is numerically conducted by optimizing the geometry of ellipsoidal reflectors at focal lengths of 1600, 1800, and 2000 mm. The Monte Carlo ray-tracing technique is employed to evaluate the optical performance of different reflector designs. The typical seven-lamp solar simulator arrangement in hexagonal configuration is modeled to analyze the optical performance at different focal lengths. In addition, different xenon arc lamps are modeled with rated powers of 3000, 4000, 4500, and 5000 W for assessing the radiative flux characteristics of the proposed solar simulators. After the optimization, theoretical results show that peak fluxes and radiative powers of 7.2-14.3MW/m2 and 5.06-10.4 kW, respectively, can be achieved with the proposed designs of solar simulators for the different rated powers. Compared with a commercial reflector, theoretical peak flux and power can be improved up to 36% and 17.9%, respectively, with the proper combination of lamp-reflector units. We provide design alternatives to select a more suitable light source at low-rated powers (≤5000W) and different focal lengths of the reflector, which simplifies the complexity of the design and improves the performance of solar simulators.

Predicting nonmuscle invasive bladder cancer recurrence and progression in patients treated with bacillus Calmette-Guerin: the CUETO scoring model.

PURPOSE: Bacillus Calmette-Guerin is the most effective therapy for nonmuscle invasive bladder cancer. Recently to calculate the risks of recurrence and progression based on data from 7 European Organisation for Research and Treatment of Cancer trials a scoring system was reported. However, in that series only 171 patients were treated with bacillus Calmette-Guerin. We developed a risk stratification model to provide accurate estimates of recurrence and progression probability after bacillus Calmette-Guerin. MATERIALS AND METHODS: Data were analyzed on 1,062 patients treated with bacillus Calmette-Guerin and included in 4 Spanish Urological Club for Oncological Treatment trials. Stepwise multivariate Cox models were used to determine the effect of prognostic factors. In each patient the weight of all factors was summed to a total score. Patients were then divided into groups, and cumulative recurrence and progression rates were calculated. RESULTS: A scoring system was calculated with a score of 0 to 16 for recurrence and 0 to 14 for progression. Patients were categorized into 4 groups by score, and recurrence and progression probabilities were calculated in each group. For recurrence the variables were gender, age, grade, tumor status, multiplicity and associated Tis. For progression the variables were age, grade, tumor status, T category, multiplicity and associated Tis. For recurrence calculated risks using Spanish Urological Club for Oncological Treatment tables were lower than those obtained with Sylvester tables. For progression probabilities were lower in our model only in patients with high risk tumors. CONCLUSIONS: We propose a scoring model to stratify the risk of recurrence and progression in patients treated with bacillus Calmette-Guerin.

Diagnosis of a primary testicular lymphoma by echography and magnetic resonance imaging.

We here describe a primary large B cell non-Hodgkin lymphoma of the right testicle in a 73-year-old male diagnosed with echography and magnetic resonance imaging. Treatment was based upon orchiectomy and chemotherapy, without any recurrence 2 years later. Ultrasonography and magnetic resonance findings with normal serum tumoural markers (AFP and B-HCG) can differentiate these tumors from germinal testicular tumors.

Pontine metastases as a cause of dysphagia in lung carcinoma.

Dysphagia is an unusual symptom in the clinical course of lung carcinoma. When it appears, it is necessary to differentiate between regional dissemination, drug toxicity, opportunistic infection and, most rarely, metastatic dissemination to the brain stem. Magnetic resonance imaging (MRI) is the best diagnostic option to exclude this last possibility. We present a male patient with progressive dysphagia 15 months after the diagnosis of an oat-cell lung carcinoma. Cerebral MRI revealed a pontine lesion, probably of metastatic origin.

Renal transplantation with venous drainage through the superior mesenteric vein in cases of thrombosis of the inferior vena cava.

Renal transplantation usually is performed by placing the graft in the iliac fossa, anastomosing the renal vein to the iliac vein or, when this is not possible, to the vena cava. When vascular complications occur, particularly on the venous side, the position of the graft may have to be changed. This report describes orthotopic renal grafts and positioning of the organ with anastomosis to the splenic vessels. Venous drainage was established directly into the mesenteric-portal territory, with two cases to the portal vein and one to the inferior mesenteric vein. A new technique for the venous drainage of the renal graft is shown. We have used this model in two cases of infrarenal inferior vena cava thrombosis. The kidney was located in a retroperitoneal position, with venous drainage to the superior mesenteric vein through an orifice in the posterior peritoneum.

The EORTC tables overestimate the risk of recurrence and progression in patients with non-muscle-invasive bladder cancer treated with bacillus Calmette-Guérin: external validation of the EORTC risk tables.

BACKGROUND: European Organization for Research and Treatment of Cancer (EORTC) risk tables only included 171 patients treated with bacillus Calmette-Guérin (BCG) for non-muscle-invasive bladder cancer (NMIBC). OBJECTIVE: To evaluate the external validity of the EORTC tables in patients with NMIBC treated with BCG over 5-6 mo. DESIGN, SETTING, AND PARTICIPANTS: Data on 1062 patients treated with BCG were analyzed. MEASUREMENTS: Discrimination was assessed using the concordance index (c-index) and the prognostic separation index (PSEP). For calibration, probabilities of recurrence and progression obtained with the EORTC risk tables in our series were compared with those reported by the EORTC. RESULTS AND LIMITATIONS: With respect to the discriminative ability of the EORTC model, c-index was similar to those reported in the EORTC series for recurrence. However, c-indices for progression in our series were lower than c-indices reported by Sylvester et al. [1]. Although PSEP in our series was lower than in the EORTC series for recurrence at 1 yr, similar results were found at 5 yr. Regarding progression, PSEP in our series was lower than in the EORTC series. Whilst a successful stratification of recurrence and progression probability at 1 and 5 yr was achieved using the EORTC tables in our series, model calibration showed lower risks of recurrence than those reported by Sylvester et al. [1] in all groups. For progression, lower risks were found in higher-risk groups. There are some limitations in the present study. A different distribution of patients was found, with higher proportions of primary grade 3 T1 tumors and tumors in situ than in the EORTC series. An additional limitation is that prior recurrence of the EORTC table was not included in our parameters. Consequently, two separate analyses were performed for recurrence. CONCLUSIONS: The EORTC model successfully stratified recurrence and progression risks in our cohort. However, the discriminative ability of the EORTC tables decreased in our patients for progression. Moreover, these tables overestimated risks of recurrence and progression after BCG therapy.

Prognostic factors in patients with non-muscle-invasive bladder cancer treated with bacillus Calmette-Guérin: multivariate analysis of data from four randomized CUETO trials.

OBJECTIVES: To evaluate the prognostic factors of recurrence and progression after intravesical adjuvant bacillus Calmette-Guérin (BCG) immunotherapy in patients with non-muscle-invasive bladder tumors. METHODS: From February 1990 to May 1999, the Spanish Club Urológico Español de Tratamiento Oncológico (CUETO) group has performed four randomized phase 3 studies comparing different intravesical treatments in patients with noninvasive bladder cancer. Data from 1062 evaluable patients treated only with BCG were analyzed. Most patients received BCG once weekly for 6 consecutive weeks and a short-term BCG maintenance (once every 2 wk 6 times more). Associated tumor in situ (TIS) was found in 7.5% (n=80) of cases. There were 22.1% (n=235) patients with T1G3 tumors, 22.9% of whom (n=54) were associated with TIS. Stepwise multivariate Cox regression models with stratification by study and dose were used to assess the independent effect of predictive factors and hazard ratios (HRs) were estimated from the Cox model. RESULTS: Multivariate analysis demonstrated that female gender (HR=1.71) compared to male gender, recurrent tumors (HR=1.9) compared to primary tumors, multiplicity, and presence of associated TIS (HR=1.54) increased the risk of recurrence. Recurrent tumors (HR=1.62) compared to primary tumors, high-grade tumors (HR=5.64) compared to G1 tumors, T1 tumors (HR=2.15) compared to Ta tumors, and recurrence at 3-mo cystoscopy (HR=4.6) increased the risk of progression. CONCLUSION: Significant independent predictors for recurrence were female gender, history of recurrence, multiplicity, and presence of associated TIS. Age, history of recurrence, high grade, T1 stage, and recurrence at first cystoscopy were independent predictors of progression by multivariate Cox analysis.

Incidencia de Aedes (S) aegypti y otros culícidos en el municipio Playa, Ciudad de La Habana / Incidence of Aedes (S) aegypti and other Culicidae in the municipality of Playa, La Habana City

An analysis was made on the incidence of Culicidae present in Playa Municipality, Havana City, during the intensive stage of the anti-aegypti campaign from June to July, 1997, according to its requirements. Culex quinquefasciatus was the predominant species with a total of 269 focuses. It was collected in all the People's Councils and in every type of repository, excepting clay repositories. The second most abundant species was the Aedes aegypti with 199 focuses, followed by Aedes mediovittatus with 67. The Almendares-Sierra, Ampliación-Almendares and Miramar People's Councils showed the highest values of Culicidae infestation in the municipality. The Aedes aegypti prevailed in the first and Cx. quiquefasciatus in the second. The artificial repositories, low tanks and other repositories had the highest number of mosquito focuses in the municipality. The Cx quinquefasciatus preferred the artificial depositories, whereas the A. aegypti preferred the low tanks. Most of the positive depositories were colonized by only one species (92.7 of the total). 7.3 corresponded to mixed focuses. It was found that Cx. quinqufasciatus and A. aegypti were the most associated species.

Indicación y utilidad de la ecografía urgente en la sospecha de apendicitis aguda / Indication and usefulness of ultrasonography for suspected acute appendicitis at the emergency department

Objetivo: La apendicitis aguda es la patología quirúrgica aguda abdominal más frecuente. Su diagnóstico constituye uno de los problemas más habituales en los servicios de urgencias. El objetivo del presente estudio es evaluar la utilidad de la ecografía abdominal en el diagnóstico de esta entidad. Material y método: Estudio retrospectivo realizado entre enero y junio del 2004 de todas las consultas realizadas en el servicio de urgencias por dolor abdominal indicativo de probable abdomen agudo, en los que se realizó una ecografía abdominal para descartar apendicitis aguda. Resultados: Se realizaron 2.015 ecografías abdominales urgentes de las cuales 296 fueron solicitadas para descartar el diagnóstico de apendicitis aguda, de éstas 288 fueron valorables. En 52 pacientes la ecografía fue indicativa de apendicitis aguda. En 15 casos el diagnóstico ecográfico fue discordante con el diagnóstico final. En 6 pacientes el informe ecográfico de apendicitis no se confirmó a posteriori. En 9 casos la ecografía fue no diagnóstica pese al diagnóstico quirúrgico de apendicitis aguda. Con estos datos, el rendimiento global de la ecografía para el diagnóstico de apendicitis aguda, se tradujo en una sensibilidad del 83,7%, especificidad del 97,4%, valor predictivo positivo del87,7%, valor predictivo negativo del 96,2%.Conclusiones: El rendimiento global de la ecografía abdominal en el diagnóstico de apendicitis aguda en nuestro medio es aceptable. Debido a su accesibilidad y bajo costees la prueba idónea para el diagnóstico en urgencias, sobre todo en casos dudosos (AU)

Objective: The aim of the present study was to assess the usefulness of ultrasonography in the diagnosis of acute appendicitis. Material and methods: Retrospective study which included patients presented in the emergency department with abdominal pain of suspected acute abdominal disorder origin and remitted to undergone ultrasonography to rule out appendicitis from January to July 2004.Results: Among 2015 ultrasonography scans 296 were performed to exclude a diagnosis of acute appendicitis. 288could be interpreted and the diagnosis of acute appendicitis was established in 52. In 15 cases the ultrasonography and the definite diagnosis differed. Ultrasonography and surgical diagnosis were different in 6 patients. In 9 patients the ultrasonography was not diagnostic. Ultrasound sensitivity, specificity, positive predictive value, and negative predictive value were 83,7%, 97,4%, 87,7% and 96,2%, respectively. Conclusions: The global cost-effectiveness of ultrasonography to diagnose appendicitis is good. Due to its availability and its low cost, ultrasonography is an accurate test for the diagnosis of acute appendicitis in emergency departments, specially in uncertain cases (AU)

Pontine metastases as a cause of dysphagia in lung carcinoma

Dysphagia is an unusual symptom in the clinical course of lung carcinoma. When it appears, it is necessary to differentiate between regional dissemination, drug toxicity, opportunistic infection and, most rarely, metastatic dissemination to the brain stem. Magnetic resonance imaging (MRI) is the best diagnostic option to exclude this last possibility. We present a male patient with progressive dysphagia 15 months after the diagnosis of an oat-cell lung carcinoma. Cerebral MRI revealed a pontine lesion, probably of metastatic origin

Arteria umbilical única: incidencias y relaciones con otras anomalías / Single umbilical artery: incidences and relations to other anomalies

Se realizó el examen del cordón umbilical en 10 074 nacimientos consecutivos y se encontró una incidencia de arteria umbilical única (AUU) de 0,27 % del total de nacimientos. Esta anomalía fue 4 veces más frecuente en niños de bajo peso al nacer. La AUU predominó en el sexo femenino. Se expresa que el 42,85 % de los niños con AUU tenía otra anomalía congénita asociada, mientras que los niños con vasos umbilicales normales representaban el 1,8 %. Se destaca que las malformaciones congénitas asociadas con AUU fueron las cardiovasculares, seguidas de las genitourinarias, del sistema nervioso central y las óseas. Se detectó un recién nacido con 5 vasos umbilicales