Phosphorus saturation and superficial fertilizer application as key parameters to assess the risk of diffuse phosphorus losses from agricultural soils in Brazil.

In Brazil, a steady increase in phosphorus (P) fertilizer application and agricultural intensification has been reported for recent decades. The concomitant P accumulation in soils potentially threatens surface water bodies with eutrophication through diffuse P losses. Here, we demonstrated the applicability of a soil type-independent approach for estimating the degree of P saturation (DPS; a risk parameter of P loss) by a standard method of water-soluble phosphorus (WSP) for two major soil types (Oxisols, Entisols) of the São Francisco catchment in Brazil. Subsequently, soil Mehlich-1P (M1P) levels recommended by Brazilian agricultural institutions were transformed into DPS values. Recommended M1P values for optimal agronomic production corresponded to DPS values below critical thresholds of high risks of P losses (DPS=80%) for major crops of the catchment. Higher risks of reaching critical DPS values due to P accumulation were found for Entisols due to their total sorption capacities being only half those of Oxisols. For complementary information on soil mineralogy and its influence on P sorption and P binding forms, Fourier transformation infrared (FTIR) spectroscopic analyses were executed. FTIR analyses suggested the occurrence of the clay minerals palygorskite and sepiolite in some of the analyzed Entisols and the formation of crandallite as the soil specific P binding form in the investigated Oxisols. Palygorskite and sepiolite can enhance P solubility and hence the risk of P losses. In contrast, the reshaping of superphosphate grains into crandallite may explain the chemical processes leading to previously observed low dissolved P concentrations in surface runoff from Oxisols. To prevent high risk of P losses, we recommend avoiding superficial fertilizer application and establishing environmental thresholds for soil M1P based on DPS. These measures could help to prevent eutrophication of naturally oligotrophic surface waters, and subsequent adverse effects on biodiversity and ecosystem function.

Cierre de bolsillo subpectoral para la reconstrucción mamaria: descripción de una nueva técnica quirúrgica mediante el uso de celulosa oxidada regenerada NU-KNIT® / Closure of the sub pectoral pocket for breast reconstruction: description of a new surgical technique using oxidized regenerated cellulose NU-KNIT TM

Introducción: El uso de expansor mamario, previo a la reconstrucción definitiva con prótesis, no está exento de complicaciones. Las mismas no solo tienen relación con la presencia de radioterapia perioperatoria, o factores propios de las pacientes, sino que también guardan relación con la cobertura muscular íntegra del expansor mamario. Material y métodos: Revisión retrospectiva de pacientes sometidas a reconstrucción mamaria diferida utilizando una modificación de la técnica del cierre de bolsillo submuscular con celulosa oxidada regenerada NU-KNIT® de expansor mamario. Entre el 1 de enero de 2014 y el 31 de diciembre de 2015 un solo cirujano plástico (J.V.) de la Unidad de Patología Mamaria de la Clínica Alemana de Santiago realizó reconstrucción con dicha técnica en 31 pacientes. Se describe la modificación de la técnica, así como los datos demográficos, histológicos y complicaciones de la fase de expansión de las mismas. Resultados: Se realizaron 40 reconstrucciones mamarias en 31 pacientes. Se presentaron 11 seromas (27,5% del total de los expansores), 2 sufrimientos de colgajo cutáneo con dehiscencia de la herida (5% de los expansores) y una infección de la herida operatoria (2,5% de los expansores). Dos pacientes requirieron aseo quirúrgico por dehiscencia e infección. Una paciente requirió explantación del expansor (2,5% del total de los expansores). Discusión: La modificación de la técnica quirúrgica representa una alternativa segura y reproducible para lograr un cierre total del bolsillo muscular y con ello la cobertura completa del expansor, evitando así algunas de las complicaciones descritas secundarias a una cobertura insuficiente del mismo.

Introduction: The use of breast expander, prior to the final prosthetic reconstruction, is not exempt from complications. They not only relate to the presence of peri-operative radiation therapy, or patient-related issues; but also related to the muscle integrate coverage of the breast expander. Material and methods: Retrospective review of patients undergoing deferred breast reconstruction using a modification of the technique of sub muscular pocket closing with oxidized regenerated cellulose NU-KNIT TM for the breast expander. Between January 1, 2014 and December 31, 2015 one plastic surgeon (J.V.), from the Breast Pathology Unit at Clínica Alemana de Santiago, performed reconstruction surgeries with this technique in 31 patients. In the present article, the technique modification, demographic data, histological data and the complications which arose during the expansion phase of the same, will be described. Results: 40 breast reconstructions were performed in 31 patients. 11 seromas (27.5% of total expanders), 2 sufferings of skin flap wound dehiscence (5% expanders) and 1 wound infection (2.5% of expanders) were presented. Two patients required surgical debridement due to surgical dehiscence and infection. One patient required explantation of the expander (2.5% of total expanders). Discussion: The modification of the surgical technique represents a safe and reproducible alternative to achieve a complete closure of the muscular pocket and thus a complete coverage of the expander, consequently; avoiding some of the secondary complications drawn from an insufficient coverage of the expander.

Estimation of the degree of soil P saturation from Brazilian Mehlich-1 P data and field investigations on P losses from agricultural sites in Minas Gerais.

The degree of phosphorus saturation (DPS) of agricultural soils is studied worldwide for risk assessment of phosphorus (P) losses. In previous studies, DPS could be reliably estimated from water-soluble P (WSP) for European and Brazilian soils. In the present study, we correlated measured WSP and Mehlich-1 P (M1P) from soils of Minas Gerais (MG) and Pernambuco (PE) (R(2) = 0.94, n = 59) to create a DPS map from monitoring data. The resulting DPS map showed high spatial variability and low values of DPS (54 ± 22%, mean and standard deviation; n = 1,827). Measured soil DPS values amounted to 63 ± 14% and resulted in relatively low dissolved P concentrations measured in a surface runoff study in MG. However, fertilizer grains on the soil surface led to high WSP values (>30 mg/kg) indicating high risks of dissolved P losses. We suppose that small Oxisol particles with Fe and Al hydroxides sorbed most of the dissolved fertilizer P in runoff so that P was mainly exported in particulate form. In soils with lower contents of P sorption and binding partners, e.g. Entisols in PE, this effect may be less dominant. Consequently, superficial fertilizer effects have to be considered in addition to DPS in risk assessment of P losses from agricultural areas in Brazil.

Real-time high-resolution X-ray imaging and nuclear magnetic resonance study of the hydration of pure and Na-doped C3A in the presence of sulfates.

This study details the differences in real-time hydration between pure tricalcium aluminate (cubic C(3)A or 3CaO·Al(2)O(3)) and Na-doped tricalcium aluminate (orthorhombic C(3)A or Na(2)Ca(8)Al(6)O(18)), in aqueous solutions containing sulfate ions. Pure phases were synthesized in the laboratory to develop an independent benchmark for the reactions, meaning that their reactions during hydration in a simulated early age cement pore solution (saturated with respect to gypsum and lime) were able to be isolated. Because the rate of this reaction is extremely rapid, most microscopy methods are not adequate to study the early phases of the reactions in the early stages. Here, a high-resolution full-field soft X-ray imaging technique operating in the X-ray water window, combined with solution analysis by (27)Al nuclear magnetic resonance (NMR) spectroscopy, was used to capture information regarding the mechanism of C(3)A hydration during the early stages. There are differences in the hydration mechanism between the two types of C(3)A, which are also dependent on the concentration of sulfate ions in the solution. The reactions with cubic C(3)A (pure) seem to be more influenced by higher concentrations of sulfate ions, forming smaller ettringite needles at a slower pace than the orthorhombic C(3)A (Na-doped) sample. The rate of release of aluminate species into the solution phase is also accelerated by Na doping.

A new procedure for evaluation of renal function without urine collection in rat.

BACKGROUND: A new procedure to improve the accuracy of inulin assessment and renal glomerular filtration rate (GFR) avoiding urine sampling was compared and validated versus the reference procedure (with urine sampling and Anthrone reaction) in conscious unrestrained male Wistar rats. METHODS: The hemodynamic study consisted of a priming dose of inulin (16 mg/kg) and para-aminohippurate (PAH; 8 mg/kg) followed by an infusion of inulin (36 mg/mL) and PAH (5.8 mg/mL) at a rate of 0.055 mL/min until steady-state conditions were reached (105 min). Inulin concentrations from samples were determined by a new enzymatic assay and Anthrone reaction. PAH concentrations were determined according to the standard method described by Smith et al. RESULTS: A high correlation was found between GFR and renal blood flow (RBF) values calculated using the alternative (without urine sampling) and the reference (with urine sampling) clearance techniques (r = 0.98, P < 0.001, and r = 0.97, P < 0.001, respectively). Moreover, a significant and positive correlation between the values obtained from enzymatic and Anthrone inulin assessments was found (r = 0.99, P < 0.001). Likewise, the values of the 95% confidence interval (mean +/- 2 SD) for the enzymatic inulin assay showed a good agreement with those achieved with Anthrone (1.14 +/- 0.21 and 1.14 +/- 0.19 mL. min-1. 100 g-1 rat body weight, respectively). CONCLUSIONS: This new approach has methodological and experimental advantages with respect to traditional procedures, making it a useful tool, not only for research purposes but also in the clinical setting.

Case-control study of factors associated with nutritional rickets in Nigerian children.

OBJECTIVE: Because the causes of nutritional rickets in tropical countries are poorly understood, we conducted a case-control study to determine factors associated with rickets in Nigerian children. STUDY DESIGN: We compared 123 Nigerian children who had rickets with matched control subjects. Dietary, demographic, anthropometric, and biochemical data were collected to assess factors related to calcium and vitamin D status, which might predispose children to rickets. RESULTS: Mean (+/- SD) daily dietary calcium intake was low in both children with rickets and control children (217 +/- 88 mg and 214 +/- 77 mg, respectively; P =.64). Children with rickets had a greater proportion of first-degree relatives with a history of rickets (14.6% vs 3.1%; P <.001), a shorter mean duration of breast-feeding (16.0 vs 17.3 months; P =.041), and a delayed age of walking (14 vs 12 months; P <.001). Among children with rickets, biochemical features suggestive of calcium deficiency included hypocalcemia, extremely low calcium excretion, and elevated 1, 25-dihydroxyvitamin D and parathyroid hormone values. Median 25-hydroxyvitamin D concentrations were 32 and 50 nmol/L (13 and 20 ng/mL) in children with rickets and control children, respectively (P <.0001). Only 46 subjects with rickets (37%) had 25-hydroxyvitamin D values <30 nmol/L (12 ng/mL). CONCLUSIONS: Vitamin D deficiency appears unlikely to be the primary etiologic factor of rickets in African children. Moreover, low dietary calcium intake alone does not account for rickets. Insufficient dietary calcium probably interacts with genetic, hormonal, and other nutritional factors to cause rickets in susceptible children.

Absence of vitamin D deficiency in young Nigerian children.

OBJECTIVE: To determine the prevalence of vitamin D deficiency in young Nigerian children residing in an area where nutritional rickets is common. STUDY DESIGN: A randomized cluster sample of children aged 6 to 35 months in Jos, Nigeria. RESULTS: Of 218 children evaluated, no child in the study had a 25-hydroxyvitamin D (25-OHD) concentration <10 ng/mL (the generally held definition of vitamin D deficiency). Children spent an average of 8.3 hours per day outside of the home. Twenty children (9.2%) had clinical findings of rickets. Children with clinical signs of rickets were more likely to be not currently breast fed and have significantly lower serum calcium concentrations than those without signs of rickets (9.1 vs 9.4 mg/dL, respectively, P =.01). Yet, 25-OHD levels were not significantly different between those children with clinical signs of rickets and those without such clinical signs. CONCLUSION: Vitamin D deficiency was not found in this population of young children in whom clinical rickets is common. This is consistent with the hypothesis that dietary calcium insufficiency, without preexisting vitamin D deficiency, accounts for the development of clinical rickets in Nigerian children.

PIP: Deficiencies of either calcium or vitamin D can cause nutritional rickets. Findings are reported from a study conducted to assess the prevalence of vitamin D deficiency in young Nigerian children living in an area where nutritional rickets is common. A random sample of 218 children aged 6-35 months in Jos, Nigeria, was evaluated. The children were of mean age 22 months. No child had a 25-hydroxyvitamin D (25-OHD) concentration of less than 10 ng/ml, the generally held definition of vitamin D deficiency. Children spent an average of 8.3 hours/day outside of the home, and 20 children (9.2%) had clinical findings of rickets. Children with clinical signs of rickets were more likely to be not currently breast-fed and have significantly lower serum calcium concentrations than those with no signs of rickets. 25-OHD levels were not significantly different between children with clinical signs of rickets and those without such clinical signs. The failure to find vitamin D deficiency in this population of young children in whom clinical rickets is common is consistent with the hypothesis that dietary calcium insufficiency, without preexisting vitamin D deficiency, accounts for the development of rickets in Nigerian children.

The use of high-frequency ultrasound for the dissection of small-diameter blood vessels and nerves.

The Cavitron ultrasonic surgical aspirator has been successfully used in general surgery and neurosurgery. We have explored its use in the dissection of small-diameter blood vessels and nerves (1-2 mm) in a rat model. Our results seem to indicate that this technique may be useful in isolating blood vessels surrounded by fatty tissue without damage to the vessel itself. In this study, however, high-frequency ultrasound did cause significant damage to peripheral nerves.

Relationship between high school student smoking and recognition of cigarette advertisements.

We report the results of a study examining the level of advertisement recognition and tobacco experimentation in a group of U.S. high school students. Students who smoked as few as one cigarette per week were found to identify a preferred cigarette brand. One brand of cigarettes accounted for 76% of all preferred brands. A dose-response relationship was found between smoking level and cigarette advertisement recognition, with regular smokers recognizing 61.6% of advertisements, compared with only 33.2% for nonsmokers. These data have potential implications for youth smoking prevention programs. Future research is needed to explain this association and to establish whether cigarette advertising and adolescent smoking are causally related.

Epidemiologic observations on the relationship between calcium intake and eclampsia.

In Guatemala, the obstetric population has a very low incidence of eclampsia despite the presence of factors that would be expected to favor appearance of the disease. In this study, the eclampsia incidence and calcium intake for three countries, Guatemala (low eclampsia incidence, high calcium intake); Cali, Colombia (high eclampsia incidence, low calcium intake); and the USA (low eclampsia incidence, high calcium intake) have been compared. Crude rates for eclampsia incidence were adjusted to control the effects of well-documented predisposing factors: age, parity, and prenatal care. Results of the study support an association between calcium intake and development of eclampsia.

Evaluation of radiation-induced chromosomal aberrations in human peripheral blood lymphocytes in vitro: result of an IAEA-coordinated programme.

The results of an IAEA coordinated programme on radiation induced chromosomal aberrations in human peripheral blood lymphocytes in vitro are presented. In a master experiment, a whole blood sample from one donor was irradiated with 200 R of X-rays. Different fixation times from 46 to 82 h were used. The progression of cells into mitosis was monitored by BrdUrd incorporation. 14 investigators took part in the scoring of chromosomal aberrations. The main conclusions of this study are: (1) The mean frequencies of aberrations changed with fixation time. (2) The number of cells scored as aberrant by different laboratories was very similar, but there was variability in the number of aberrations scored per aberrant cell. (3) The differences in the frequencies of aberrations between laboratories were minimal when the scoring was restricted to the first major peak of mitotic activity and sufficient cells were scored. It is concluded that using controlled experimentals conditions, human peripheral blood lymphocytes can effectively be used as a reliable biological dosimeter for absorbed radiation dose.