Possible effects of clustering structure in the competition between fast emission processes and compound nucleus decay / Posibles efectos de estructura de agrupamiento en la competencia entre los procesos de emisión rápida y desintegración del núcleo compuesto

Abstract The attention to nuclear clustering has been renewed due to the study of weakly bound nuclei at the drip lines. In particular, clustering structural properties in medium-mass systems have been studied by looking at the competition between the evaporation and pre-equilibrium particle emission in central collisions. Although for light nuclei at an excitation energy close to the particle separation value there are experimental evidence of such structure effects, this is still not the case for heavier systems since the determination of pre-formed clusters within nuclear matter is less obvious. Two systems, leading to the same 81Rb* compound nucleus, have been studied at the same beam velocity 16 AMeV: 16O + 65Cu and 19F + 62Ni. The experiment has been performed using the GARFIELD + RCo detection system installed at the Legnaro National Laboratories.Light charged particles energy distributions and multiplicities have been compared with different statistical and dynamical model calculations. From the first comparison between the two systems a difference in the fast α-decay channel has been evidenced, which can be related to the difference in the projectile structure. Recent data analysis results and comparisons with model calculations are presented in this contribution.

Resumen La atención a la agrupación nuclear se ha renovado debido al estudio de núcleos débilmente unidos en las líneas de goteo. En particular, se han estudiado las propiedades estructurales del agrupamiento en sistemas de masa media al observar la competencia entre la evaporación y la emisión de partículas de preequilibrio en colisiones centrales. Aunque para núcleos ligeros a una energía de excitación cercana al valor de separación de la partícula hay evidencia experimental de tales efectos de estructura, este no es el caso para sistemas más pesados ya que la determinación de agrupamientos preformados dentro de la materia nuclear es menos obvia. Se han estudiado dos sistemas, que conducen al mismo núcleo compuesto 81Rb *, a la misma velocidad de haz 16 AMeV: 16O + 65Cu y 19F + 62Ni. El experimento se ha realizado utilizando el sistema de detección GARFIELD + RCo instalado en los Laboratorios Nacionales Legnaro. Las distribuciones de energía y las multiplicidades de partículas de carga ligera se han comparado con diferentes cálculos de modelos estadísticos y dinámicos. Desde la primera comparación entre los dos sistemas, se ha evidenciado una diferencia en el canal de desintegración α rápida, que se puede relacionar con la diferencia en la estructura del proyectil. En esta contribución se presentan los resultados del análisis de datos recientes y las comparaciones con los cálculos del modelo.

Gunshot injuries in the spine.

STUDY DESIGN: Review article. OBJECTIVES: To review the literature regarding treatment approaches in cases of gunshot wounds (GSWs) affecting the spine. SETTING: Brazil. METHODS: Narrative review of medical literature. RESULTS: GSWs are an increasing cause of morbidity and mortality. Most patients with spinal GSW have complete neurological deficit. The injury is more common in young men and is frequently immobilizing. The initial approach should follow advanced trauma life support, and broad-spectrum antibiotic therapy should be initiated immediately, especially in patients with perforation of the gastrointestinal tract. The indications for surgery in spinal GSW are deterioration of the neurologic condition in a patient with incomplete neurological deficit, the presence of liquor fistula, spinal instability, intoxication by the metal from the bullet or risk of bullet migration. CONCLUSION: Surgical treatment is associated with a higher complication rate than conservative treatment. Therefore, the surgeon must know the treatment limitations and recognize patients who would truly benefit from surgery.

Poliposis adenomatosa familiar: presentación de un caso clínico / Familial adenomatous polyposis: case report

La poliposis adenomatosa familiar (PAF) es una enfermedad autosómica dominante caracterizada por la presencia de más de cien pólipos a nivel colorrectal. Se presenta el caso clínico de una paciente colectomizada por PAF que en la evolución desarrolla complicaciones extracolónicas de la enfermedad (adenomas duodenales), cuyo control y tratamiento es objeto de discusión. (AU)

Poliposis adenomatosa familiar: presentación de un caso clínico / Familial adenomatous polyposis: case report

La poliposis adenomatosa familiar (PAF) es una enfermedad autosómatica dominante caracterizada por la presencia de más de cien pólipos a nivel colorrectal. Se presenta el caso clínico de una paciente colectomizada por PAF que en la evolución desarrolla complicaciones extracolónicas de la enfermedad (adenomas duodenales), cuyo control y tratamiento es objeto de discusión.

Association of visceral fat with coronary risk factors in a population-based sample of postmenopausal women.

OBJECTIVE: To investigate in a population-based random sample of postmenopausal women the adjusted association of visceral adipose tissue (VAT) with coronary risk factors. DESIGN: Cross-sectional population-based random sample study. SUBJECTS: Ninety-eight postmenopausal women (age 50-65 y). MEASUREMENTS: Visceral and subcutaneous fat areas by computer axial tomography, anthropometry, lipid profile, fasting glucose and insulin, diet, physical activity, smoking status and alcohol intake. RESULTS: Compared to women with low VAT, women with high VAT (>117.8 cm(2)) had a less favorable metabolic profile with significantly higher fasting glucose (120+/-50 vs 98+/-39), insulin (7.9+/-10 vs 5+/-8), triglycerides (172+/-69 vs 127+/-72), apolipoprotein B (119+/-24 vs 98+/-32) and significantly lower HDL-C (38+/-10 vs 46+/-14) values in the whole sample (n=98). A similar profile was found in women without diabetes and hypertension (n=39). In multiple regression models, VAT explained a portion of the variance of TG (6.2%) in the entire sample and of total cholesterol (12.4%), LDL-C (15.8%), triglycerides (16.3%), apolipoprotein B (11.6%), and fasting glucose (28.4%) in the group of non-diabetic or hypertensive women. Our VAT cut-off point of 117.8 cm(2) corresponded to a waist circumference of 84 cm. CONCLUSION: Our results in a random population-based sample of postmenopausal women confirm the association of VAT with most coronary risk factors. These associations persisted after adjusting for diet, physical activity, smoking status and alcohol intake.

LDL size and susceptibility to oxidation in experimental nephrosis.

The aim of this study was to investigate the relationship between endothelial dysfunction and low density lipoprotein (LDL) size and susceptibility to oxidation in nephrotic rats with or without deficiency of vitamin E and selenium. Four groups of male Wistar rats were studied: control (C), vitamin E and selenium deficient control (DefC), nephrotic (NS), and vitamin E and selenium deficient NS (DefNS). Nephrotic syndrome was induced by puromycin aminonucleoside. The molar ratio of vitamin E/LDL-cholesterol was significantly lower in DefNS, DefC rats, and NS vs. C rats. In comparison with control animals, vasodilation and LDL oxidability were significantly lower in nephrotic animals. LDL size was similar in all groups. Abnormal endothelial function in response to acetylcholine and carbachol was observed in NS animals compared to control rats. Relaxation response was inversely associated with an increase in LDL susceptibility to oxidation and with a lower molar ratio of vitamin E/LDL-c. LDL oxidability and LDL-c were the only variables independently associated with vasodilation. These results suggest that endothelial dysfunction of NS may be a consequence of the increased LDL susceptibility to oxidation, secondary to antioxidant deficiency.

Differential effects of obesity with and without hyperinsulinemia on plasma lipoprotein(a) concentrations in men.

To determine the association of in vivo concentrations of insulin, obesity, and gender with lipoprotein(a) [Lp(a)] levels, we used a cross-sectional population-based survey of a multistage random sample of the Mexico City adult population. We studied 423 normoglycemic, normotensive subjects from an original sample of 825, comprised of 239 men and 189 women with a mean age of 38.6 years (range, 17 to 90). All subjects were divided into 8 groups according to body mass index, fasting insulin, and gender. Lp(a) concentrations (mg/dL) were similar in obese women with and without high insulin levels (19.9 v 18.6), but hyperinsulinemic obese men had significantly lower Lp(a) levels than normoinsulinemic obese men (7.9 v 29.4). In addition, the proportion of obese men with Lp(a) concentrations of > or = 30 mg/dL was significantly higher in the normoinsulinemic than in the hyperinsulinemic (29.2% v 0.0%). The frequency distribution of Lp(a) levels was shifted to a lower range in hyperinsulinemic men compared with normoinsulinemic men. Our results show that in men, hyperinsulinemic obesity is associated with low Lp(a) levels, while obesity with normoinsulinemia is related to increased Lp(a) concentration. These observations were not found in women. These findings may explain the conflicting results reported by several studies.

Effect of the new diagnostic criteria for diabetes in the Mexico City study.

OBJECTIVE: To assess the effect of the new American Diabetes Association (ADA) diagnostic criteria for diabetes in the Mexico City survey. METHODS: The data available from the Mexico City study were included. This cross-sectional survey was conducted from January 1991 to March 1992 and involved 805 adults (20 years of age or older; mean age, 41 years). Survey procedures and results were previously published. Of the residents with diabetes, 74.2% had a previous diagnosis, and 25.8% were diagnosed on the basis of fasting plasma glucose (FPG) levels obtained during the survey. For the current report, these data were reanalyzed on the basis of the new ADA diagnostic criteria. RESULTS: The prevalence of newly diagnosed diabetes with use of the old and the new criteria was 23.1% versus 32.3% in men (P = 0.31) and 27.5% versus 36.3% in women (P = 0.32), respectively. The crude prevalence rate of diabetes increased from 8.7% to 9.3% (P = 0.42), and the age-adjusted rate increased from 10.6% to 11.2% for women (P = 0.64) and from 6.0% to 6.5% for men (P = 0.49). The prevalence of impaired FPG was 4.8%. Those patients with impaired FPG or newly diagnosed diabetes with FPG levels between 126 and 140 mg/dL had a more atherogenic risk profile than did those with normal carbohydrate metabolism. CONCLUSION: On the basis of the 1990 population census in Mexico City, the new ADA criteria will add 28,331 patients with diabetes (6.9%) to an already insufficient medical system. For those patients with impaired FPG or newly diagnosed diabetes on the basis of the new criteria, management should be focused on the control of the diverse and highly prevalent coronary risk factors.

Resultados das derivaçöes infra-inguinais até segmento isolado de artéria / Results of infra-inguinal by-passes to isolated artery segment

Os autores apresentam sua experiência com 23 casos operados e nos quais foi feita revascularização do membro inferior por meio de derivaçöes em que a anastomose distal foi implantada num segmento isolado de artéria. A perviedade cumulativa no grupo em que foram usadas próteses (7 casos), a taxa foi de 21 'por cento'. Os resultados obtidos quanto à preservação do membro foram elevados, sendo de 81 'por cento' e 87 'por cento' respectivamente para as lesöes estáveis e instáveis.