Time-domain transmission sensor system for on-site dielectric permittivity measurements in soil: A compact, low-cost and stand-alone solution.

Dielectric-based measurement techniques have been shown to be very effective in determining the properties of various materials. These techniques have been widely used in a variety of fields and applications. Time Domain Transmission (TDT) techniques have grown in popularity because they are practical, non-destructive, provide measurements in real time and produce accurate measurements that are independent of multiple reflections. TDT techniques, on the other hand, are mostly performed with specialized bulky laboratory equipment, such as a Vector Network Analyzer (VNA) which makes TDT measurements prohibitively costly and unpractical. In fact, few works in the literature have reported portable on-site TDT systems. The aim of this paper is to design and implement a dedicated, compact, and low-cost microwave Time Domain Transmission (TDT) sensor for measuring superficial soil dielectric properties on-site. Our sensor uses a time-delay measurement technique over a microstrip transmission line to estimate the dielectric properties of the soil under test. Measurement results show that the computed mean absolute error (MAE) is less than 1.2 when compared to a calibrated dielectric assessment kit (DAK) with soils containing less than 20 % of water ( ε ' r < 5.0 ), implying that our TDT sensor system can obtain on-site measurements in relatively dry soils with acceptable accuracy.

Intima media thickness in children undergoing dialysis.

BACKGROUND: Uremic vasculopathy, including vascular calcification, increases the risk for cardiovascular disease and mortality in chronic kidney disease (CKD) patients. We have investigated the prevalence and factors associated with vasculopathy in children undergoing peritoneal dialysis (PD) or hemodialysis (HD) in a single center. METHODS: Common carotid intima media thickness (cIMT) and its relation with demographics, biochemical parameters and medication was analyzed in 60 patients (mean age 12.9 ± 3.4 years; 27 girls) treated with PD (n = 31) or HD (n = 29) for 34 ± 34 months. Patients were divided into two groups: normal cIMT and increased cIMT. RESULTS: Mean levels of calcium, phosphate and calcium/phosphate product were in the normal range, the but parathyroid hormone level, 729 ± 670 pg/mL, was higher than the National Kidney Foundation Kidney Disease Outcome Quality Iniative (K/DOQI) recommendations. Twenty-nine patients had increased cIMT, which was associated with time on dialysis of >2 years, hypercalcemia, higher daily dose of calcitriol and HD (vs. PD). In the multivariate analysis, accounting for time on dialysis, HD persisted as a risk for increased cIMT. CONCLUSIONS: The prevalence of increased cIMT in children on dialysis is similar to that reported in adults with CKD and increased with time on dialysis. HD was associated with increased cIMT, independently of time on dialysis; however, the results should be interpreted with caution due to the possible impact of confounding factors. These results underline the need to monitor and, if possible, prevent and treat increased cIMT in children on dialysis.

Exenteración pélvica, morbilidad y supervivencia / Pelvic exenteration; morbidity and survival

Entre 1985 y 1990, 17 pacientes fueron sometidas a exenteración pélvica en el Hospital de Ginecología y Obstetriia No. 4 del Instituto Mexicano del Seguro Social en la ciudad de México. Dieciséis pacientes habían recibido radioterapia previamente. La mayor parte de los procedimientos quirúrgicos fueron llevados a cabo por cáncer de cervix, recurrente o persistente. El principal tipo histológico de la neoplasia cervical fue carcinoma epidermoide, 15 casos. En ningún caso la cirugía fue llevada a cabo en presencia de nódulos linfáticos positivos. La mortalidad quirúrgica fue 5.9 por ciento. Una o más complicaciones quirúrgicas, se presentaron en nueve pacientes, tres pacientes requirieron más de un procedimiento quirúrgico para corregir tales complicaciones. No hubo mortalidad por reoperación. Cinco pacientes tuvieron complicaciones no quirúrgicas. Todas las pacientes fueron seguidas por al menor dos años o hasta el momento de su muerte. La supervivencia acumulativa a cinco años estuvo relacionada significativamente al tipo de tumor. Todas las pacientes con tumor recurrente estaban vivas en el último seguimiento, comparado con sólo 33 por ciento de pacientes con tumor persistente. Cuatro pacientes fueron tratadas con exentración pélvica anterior, todas con tumor persistente, de estas, tres tuvieron recurrencia documentada y ninguna sobrevivió más allá de 14 meses

Ethanol consumption during pregnancy and lactation: changes in the nutritional status of predominantly breastfeeding mothers

The purpose of this investigation was to study the effects of ethanol, consumed as a mild fermented beverage called "pulque", during pregnancy and lactation on the food intake ands some antropometric indices of body composition of a group of lactating mothers in a town in central Mexico. Thirty two mothers who drank pulque during pregnancy and lactation and 61 non-drinking women with comparable characteristics were evaluated anthropometrically, their dietary and ethanol intake recorded during a 6-month postpartum period. Energy [(8360 ñ 2997 vs. 7156 ñ 2177J) and protein (52.7 ñ 20.9 vs. 44.6 ñ 16.1 g)] 24-h intake, height, weight, body mass index, arm muscle and fat areas were greater in drinking mothers than in controls. Average total ethanol consumption varied from 0.48 - 0.55 g-1 Kg-1.d-1. Drinking mothers lost weight less frequently. Additional energy provided by pulque might explain such a difference. More precise information about the changes in their body composition and energy balance are in order for confirmation