963 resultados para fetal losses
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Purpose: In the last years, MRI appears as a complementary diagnostic method to US in the diagnosis of congenital lung lesions. Focal homogeneous pulmonary hyperintensity on T2-WI constitutes a frequent pattern observed. Our purpose is to determine if this finding is associated with a characteristic pulmonary lesion. Materials and methods: Between 01.01.00 and 31.12.07, a total of 50 prenatal MRI in fetuses with echographic diagnosis of thoracic pathology were performed in our institution, including 12 cases of suspected congenital pulmonary lesions. Prenatal images were correlated with post-natal diagnosis. Results: In 12 cases, fetal MRI detected congenital pulmonary lesions. In 8 patients, typical signs (cystic lesions, septations, anomalous vasculature) clearly suggested a specific pathology. In 4 cases, MRI showed a focal homogeneous increase of the signal intensity (SI) on T2-WI of the pathologic lung related to the normal one. The final diagnosis of these fetuses included 1 patient with congenital cystic adenomatoid malformation type III, 1 patient with segmental emphysema and 2 cases of bronchial atresia. In all 4 cases, a significant post-natal reduction of the lesion size related to prenatal MRI studies was observed. Conclusion: Our study suggests that a focal increment of the SI of the lung on T2-WI is a non specific sign of congenital lung disease, present in different pathologies. Therefore, a prospective diagnosis is not possible.
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The quantification of ammonia (NH3) losses from sugarcane straw fertilized with urea can be performed with collectors that recover the NH3 in acid-treated absorbers. Thus, the use of an open NH3 collector with a polytetrafluoroethylene (PTFE)-wrapped absorber is an interesting option since its cost is low, handling easy and microclimatic conditions irrelevant. The aim of this study was to evaluate the efficiency of an open collector for quantifying NH3-N volatilized from urea applied over the sugarcane straw. The experiment was carried out in a sugarcane field located near Piracicaba, São Paulo, Brazil. The NH3-N losses were estimated using a semi-open static collector calibrated with 15N (reference method) and an open collector with an absorber wrapped in PTFE film. Urea was applied to the soil surface in treatments corresponding to rates of 50, 100, 150 and 200 kg ha-1 N. Applying urea-N fertilizer on sugarcane straw resulted in losses NH3-N up to 24 % of the applied rate. The amount of volatile NH3-N measured in the open and the semi-open static collector did not differ. The effectiveness of the collection system varied non-linearly, with an average value of 58.4 % for the range of 100 to 200 kg ha-1 of urea-N. The open collector showed significant potential for use; however, further research is needed to verify the suitability of the proposed method.
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Interrill erosion occurs by the particle breakdown caused by raindrop impact, by particle transport in surface runoff, by dragging and suspension of particles disaggregated from the soil surface, thus removing organic matter and nutrients that are essential for agricultural production. Crop residues on the soil surface modify the characteristics of the runoff generated by rainfall and the consequent particle breakdown and sediment transport resulting from erosion. The objective of this study was to determine the minimum amount of mulch that must be maintained on the soil surface of a sugarcane plantation to reduce the soil, water and nutrient losses by decreasing interrill erosion. The study was conducted in Pradópolis, São Paulo State, in 0.5 x 1.0 m plots of an Oxisol, testing five treatments in four replications. The application rates were based on the crop residue production of the area of 1.4 kg m-2 (T1- no cane trash; T2-25 % of the cane trash; T3- 50 % trash; T4-75 % trash; T5-100 % sugarcane residues on the surface), and simulated rainfall was applied at an intensity of 65 mm h-1 for 60 min. Runoff samples were collected in plastic containers and soon after taken to the laboratory to quantify the losses of soil, water and nutrients. To minimize soil loss by interrill erosion, 75 % of the cane mulch must be maintained on the soil, to control water loss 50 % must be maintained and 25 % trash controls organic matter and nutrient losses. This information can contribute to optimize the use of this resource for soil conservation on the one hand and the production of clean energy in sugar and alcohol industries on the other.
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The soil surface roughness increases water retention and infiltration, reduces the runoff volume and speed and influences soil losses by water erosion. Similarly to other parameters, soil roughness is affected by the tillage system and rainfall volume. Based on these assumptions, the main purpose of this study was to evaluate the effect of tillage treatments on soil surface roughness (RR) and tortuosity (T) and to investigate the relationship with soil and water losses in a series of simulated rainfall events. The field study was carried out at the experimental station of EMBRAPA Southeastern Cattle Research Center in São Carlos (Fazenda Canchim), in São Paulo State, Brazil. Experimental plots of 33 m² were treated with two tillage practices in three replications, consisting of: untilled (no-tillage) soil (NTS) and conventionally tilled (plowing plus double disking) soil (CTS). Three successive simulated rain tests were applied in 24 h intervals. The three tests consisted of a first rain of 30 mm/h, a second of 30 mm/h and a third rain of 70 mm/h. Immediately after tilling and each rain simulation test, the surface roughness was measured, using a laser profile meter. The tillage treatments induced significant changes in soil surface roughness and tortuosity, demonstrating the importance of the tillage system for the physical surface conditions, favoring water retention and infiltration in the soil. The increase in surface roughness by the tillage treatments was considerably greater than its reduction by rain action. The surface roughness and tortuosity had more influence on the soil volume lost by surface runoff than in the conventional treatment. Possibly, other variables influenced soil and water losses from the no-tillage treatments, e.g., soil type, declivity, slope length, among others not analyzed in this study.
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Hypomagnesemia and hypophosphatemia are frequent after severe burns; however, increased urinary excretion does not sufficiently explain the magnitude of the mineral depletion. We measured the mineral content of cutaneous exudates during the first week after injury. Sixteen patients aged 34 +/- 9 y (mean +/- SD) with thermal burns were studied prospectively and divided in 3 groups according to the extent of their burn injury and the presence or absence of mineral supplements: group 1 (n = 5), burns covering 26 +/- 5% of body surface; group 2 (n = 6), burns covering 41 +/- 10%; and group 3 (n = 5), burns covering 42 +/- 6% with prescription of magnesium and phosphate supplements. Cutaneous exudates were extracted from the textiles (surgical drapes, dressings, sheets, etc) surrounding the patients from day 1 to day 7 after injury. Mean magnesium serum concentrations decreased below reference ranges in 12 patients between days 1 and 4 and normalized thereafter. Phosphate, normal on day 0, was low during the first week. Albumin concentrations, normal on day 0, decreased and remained low. Urinary magnesium and phosphate excretion were within reference ranges and not larger in group 3. Mean daily cutaneous losses were 16 mmol Mg/d and 11 mmol P/d (largest in group 2). Exudative magnesium losses were correlated with burn severity (r = 0.709, P = 0.003). Cutaneous magnesium losses were nearly four times larger than urinary losses whereas cutaneous phosphate losses were smaller than urinary phosphate losses. Mean daily losses of both magnesium and phosphate were more than the recommended dietary allowances. Exudative losses combined with urinary losses largely explained the increased mineral requirements after burn injury.
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Rainfall erosivity is one of the main factors related to water erosion in the tropics. This work focused on relating soil loss from a typic dystrophic Tb Haplic Cambisol (CXbd) and a typic dystrophic Red Latosol (LVdf) to different patterns of natural erosive rainfall. The experimental plots of approximately 26 m² (3 x 8.67 m) consisted of a CXbd area with a 0.15 m m-1 slope and a LVdf area with 0.12 m m-1 slope, both delimited by galvanized plates. Drainpipes were installed at the lower part of these plots to collect runoff, interconnected with a Geib or multislot divisor. To calculate erosivity (EI30), rainfall data, recorded continuously at a weather station in Lavras, were used. The data of erosive rainfall events were measured (10 mm precipitation intervals, accuracy 0.2 mm, 24 h period, 20 min intervals), characterized as rainfall events with more than 10 mm precipitation, maximum intensity > 24 mm h-1 within 15 min, or kinetic energy > 3.6 MJ, which were used in this study to calculate the rainfall erosivity parameter, were classified according to the moment of peak precipitation intensity in advanced, intermediate and delayed patterns. Among the 139 erosive rainfall events with CXbd soil loss, 60 % were attributed to the advanced pattern, with a loss of 415.9 Mg ha-1, and total losses of 776.0 Mg ha-1. As for the LVdf, of the 93 erosive rainfall events with soil loss, 58 % were listed in the advanced pattern, with 37.8 Mg ha-1 soil loss and 50.9 Mg ha-1 of total soil loss. The greatest soil losses were observed in the advanced rain pattern, especially for the CXbd. From the Cambisol, the soil loss per rainfall event was greatest for the advanced pattern, being influenced by the low soil permeability.
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The dynamics of N losses in fertilizer by ammonia volatilization is affected by several factors, making investigation of these dynamics more complex. Moreover, some features of the behavior of the variable can lead to deviation from normal distribution, making the main commonly adopted statistical strategies inadequate for data analysis. Thus, the purpose of this study was to evaluate the patterns of cumulative N losses from urea through ammonia volatilization in order to find a more adequate and detailed way of assessing the behavior of the variable. For that reason, changes in patterns of ammonia volatilization losses as a result of applying different combinations of two soil classes [Planossolo and Chernossolo (Typic Albaqualf and Vertic Argiaquolls)] and different rates of urea (50, 100 and 150 kg ha-1 N), in the presence or absence of a urease inhibitor, were evaluated, adopting a 2 × 3 × 2 factorial design with four replications. Univariate and multivariate analysis of variance were performed using the adjusted parameter values of a logistic function as a response variable. The results obtained from multivariate analysis indicated a prominent effect of the soil class factor on the set of parameters, indicating greater relevance of soil adsorption potential on ammonia volatilization losses. Univariate analysis showed that the parameters related to total N losses and rate of volatilization were more affected by soil class and the rate of urea applied. The urease inhibitor affected only the rate and inflection point parameters, decreasing the rate of losses and delaying the beginning of the process, but had no effect on total ammonia losses. Patterns of ammonia volatilization losses provide details on behavior of the variable, details which can be used to develop and adopt more accurate techniques for more efficient use of urea.
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We report on the growth of epitaxial YBa2Cu3O7 thin films on X-cut LiNbO3 single crystals. The use of double CeO2/YSZ buffer layers allows a single in-plane orientation of YBa2Cu3O7, and results in superior superconducting properties. In particular, surface resistance Rs values of 1.4 m¿ have been measured at 8 GHz and 65 K. The attainment of such low values of Rs constitutes a key step toward the incorporation of high Tc materials as electrodes in photonic and acoustic devices.
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Selostus: Typen ja fosforin kulkeutuminen pinta- ja salaojavalunnassa lietelannalla ja NKP-lannoitteella lannoitetulta nurmelta
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In order to gain insight into the biology of fetal skin during culture, cellular proteins were studied during four culture passages (P00, P01, P04 as well as P10) using high-resolution two-dimensional (2-D) gel electrophoresis and mass spectrometry (MS). Bioinformatic analyses were focused on a region of each gel corresponding to pI between 4 and 8 and M(r) from 8000 to 35 000. In this area, 373 +/- 42 spots were detected (N = 18). Twenty-six spots presented an integrated intensity that increased in the higher passages, whereas five spots showed a progressively lower intensity in subsequent passaging. MS analysis was performed on spots that were unambiguously identified on preparative 2-D gels. Among the 26 spots showing an increased size between P00 and P10, 9 were identified, and corresponded to 3 proteins: (i) peptidyl-prolyl cis-trans isomerase A (P05092; cyclophilin A or cyclosporin A-binding protein), (ii) triosephosphate isomerase (P00938), and (iii) enoyl-CoA hydratase (P30084). Among these nine identified spots, three were absent at P00, but were present at P10. They corresponded to isoforms of peptidyl-prolyl cis-trans isomerase and triosephosphate isomerase, respectively. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses of the acidic isoforms of triosephosphate isomerase showed modifications of cysteine residues to cysteic acid. All these isoforms were clearly present in the skin cells of a 4-year-old child, as well as in skin cells from a 80-year-old man, at P00. These observations probably reflect either an oxidative stress related to cell culture, or, alternatively, maturation, differentiation and the aging of the cells.
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Hygroscopic fertilizers tend to absorb moisture from the air and may have undesirable characteristics such as moistness, clumping and lower fluidity, hampering the application. The increasing use of urea is due to its numerous advantages, although this nitrogen (N) source is highly susceptible to volatilization losses, particularly when applied to the soil surface of management systems with conservation of crop residues. The volatilization losses can be minimized by slow or controlled-release fertilizers, with controlled water solubility of the urea-coating materials; and by stabilized fertilizers, which prolong the period during which N remains in the amide or ammonia forms by urease inhibitors. This study evaluated the hygroscopicity of and ammonia volatilization from urea coated with boric acid and copper sulfate or with sulfur. The hygroscopicity of the sources was evaluated over time after exposure to five levels of relative humidity (RH) and volatilization evaluated after application to the soil surface covered with sugarcane trash. Ammonium nitrate has a low potential for volatilization losses, but is highly hygroscopic. Although coating with boric acid and copper sulfate or elemental sulfur reduced the critical humidity level of urea, the delay in the volatilization process is a potential positive factor.
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AIM: The aim of this study was to determine the presence of the neuronal nitric oxide synthase (nNOS) in near full-term lambs with congenital diaphragmatic hernia (CDH) and its role in the modulation of pulmonary vascular basal tone. METHODS: We surgically created diaphragmatic hernia on the 85th day of gestation. On the 135th, catheters were used to measure pulmonary pressure and blood flow. We tested the effects of 7-nitroindazole (7-NINA), a specific nNOS antagonist and of N-nitro-L-arginine (L-NNA), a nonspecific nitric oxide synthase antagonist. In vitro, we tested the effects of the same drugs on isolated pulmonary vessels. The presence of nNOS protein in the lungs was detected by Western blot analysis. RESULTS: Neither 7-NINA nor L-NNA modified pulmonary vascular basal tone in vivo. After L-NNA injection, acetylcholine (ACh) did not decrease significantly pulmonary vascular resistance (PVR). In vitro, L-NNA increased the cholinergic contractile-response elicited by electric field stimulation (EFS) of vascular rings from lambs with diaphragmatic hernia. CONCLUSION: We conclude that nNOS protein is present in the lungs and pulmonary artery of near full-term lamb fetuses with diaphragmatic hernia, but that it does not contribute to the reduction of pulmonary vascular tone at birth
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Introduction. Development of the fetal brain surfacewith concomitant gyrification is one of the majormaturational processes of the human brain. Firstdelineated by postmortem studies or by ultrasound, MRIhas recently become a powerful tool for studying in vivothe structural correlates of brain maturation. However,the quantitative measurement of fetal brain developmentis a major challenge because of the movement of the fetusinside the amniotic cavity, the poor spatial resolution,the partial volume effect and the changing appearance ofthe developing brain. Today extensive efforts are made todeal with the âeurooepost-acquisitionâeuro reconstruction ofhigh-resolution 3D fetal volumes based on severalacquisitions with lower resolution (Rousseau, F., 2006;Jiang, S., 2007). We here propose a framework devoted tothe segmentation of the basal ganglia, the gray-whitetissue segmentation, and in turn the 3D corticalreconstruction of the fetal brain. Method. Prenatal MRimaging was performed with a 1-T system (GE MedicalSystems, Milwaukee) using single shot fast spin echo(ssFSE) sequences in fetuses aged from 29 to 32gestational weeks (slice thickness 5.4mm, in planespatial resolution 1.09mm). For each fetus, 6 axialvolumes shifted by 1 mm were acquired (about 1 min pervolume). First, each volume is manually segmented toextract fetal brain from surrounding fetal and maternaltissues. Inhomogeneity intensity correction and linearintensity normalization are then performed. A highspatial resolution image of isotropic voxel size of 1.09mm is created for each fetus as previously published byothers (Rousseau, F., 2006). B-splines are used for thescattered data interpolation (Lee, 1997). Then, basalganglia segmentation is performed on this superreconstructed volume using active contour framework witha Level Set implementation (Bach Cuadra, M., 2010). Oncebasal ganglia are removed from the image, brain tissuesegmentation is performed (Bach Cuadra, M., 2009). Theresulting white matter image is then binarized andfurther given as an input in the Freesurfer software(http://surfer.nmr.mgh.harvard.edu/) to provide accuratethree-dimensional reconstructions of the fetal brain.Results. High-resolution images of the cerebral fetalbrain, as obtained from the low-resolution acquired MRI,are presented for 4 subjects of age ranging from 29 to 32GA. An example is depicted in Figure 1. Accuracy in theautomated basal ganglia segmentation is compared withmanual segmentation using measurement of Dice similarity(DSI), with values above 0.7 considering to be a verygood agreement. In our sample we observed DSI valuesbetween 0.785 and 0.856. We further show the results ofgray-white matter segmentation overlaid on thehigh-resolution gray-scale images. The results arevisually checked for accuracy using the same principlesas commonly accepted in adult neuroimaging. Preliminary3D cortical reconstructions of the fetal brain are shownin Figure 2. Conclusion. We hereby present a completepipeline for the automated extraction of accuratethree-dimensional cortical surface of the fetal brain.These results are preliminary but promising, with theultimate goal to provide âeurooemovieâeuro of the normal gyraldevelopment. In turn, a precise knowledge of the normalfetal brain development will allow the quantification ofsubtle and early but clinically relevant deviations.Moreover, a precise understanding of the gyraldevelopment process may help to build hypotheses tounderstand the pathogenesis of several neurodevelopmentalconditions in which gyrification have been shown to bealtered (e.g. schizophrenia, autismâeuro¦). References.Rousseau, F. (2006), 'Registration-Based Approach forReconstruction of High-Resolution In Utero Fetal MR Brainimages', IEEE Transactions on Medical Imaging, vol. 13,no. 9, pp. 1072-1081. Jiang, S. (2007), 'MRI of MovingSubjects Using Multislice Snapshot Images With VolumeReconstruction (SVR): Application to Fetal, Neonatal, andAdult Brain Studies', IEEE Transactions on MedicalImaging, vol. 26, no. 7, pp. 967-980. Lee, S. (1997),'Scattered data interpolation with multilevel B-splines',IEEE Transactions on Visualization and Computer Graphics,vol. 3, no. 3, pp. 228-244. Bach Cuadra, M. (2010),'Central and Cortical Gray Mater Segmentation of MagneticResonance Images of the Fetal Brain', ISMRM Conference.Bach Cuadra, M. (2009), 'Brain tissue segmentation offetal MR images', MICCAI.
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The study was performed to evaluate the prevalence of prenatal ultrasound diagnoses for renal anomalies in 20 registries of 12 European countries, and to compare the different prenatal scanning policies. Standardized data were acquired from 709,030 livebirths, stillbirths, and induced abortions during the study period of 2.5 years and transmitted for central analysis. At least one renal malformation was diagnosed in 1130 infants and fetuses. Prenatal diagnosis (PD) was given in 81.8% of all cases, 29% of these pregnancies were terminated. The highest detection rate was reported for unilateral multicystic dysplastic kidneys with 97% (102/105). An early diagnosis was documented for exstrophy of bladder at a mean gestational age of 18.5 weeks. Dilatations of the upper urinary tract were seen late in pregnancy at 28.3 weeks. Terminations of pregnancies (TOP) were performed in 67% (58/86) of the detected bilateral renal agenesis/dysgenesis, but only 4% of the unilateral multicystic dysplastic renal malformations (4/102). In about 1/3 of the cases, renal malformations are within the category of associated malformations, which include multiple non-syndromal malformations, chromosomal aberrations, and non-chromosomal syndromes. Renal malformations were detected in 2/3 of the associated category by the first prenatal ultrasound scan. Detection rates vary in the different countries of the European community due to diverse policies, ethical, and religious background. Countries with no routine ultrasound show the lowest rates in detection, and termination of pregnancy. Prenatally detected renal malformations should result in a careful examination for further anomalies. Prenatal ultrasound fulfills the needs of screening examinations and is a good tool in detecting lethal and severe renal malformations.
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High mortality in newborn babies with congenital diaphragmatic hernia (CDH) is principally due to persistent pulmonary hypertension. ATP-dependent potassium (K(ATP)) channels might modulate pulmonary vascular tone. We have assessed the effects of Pinacidil, a K(ATP) channel opener, and glibenclamide (GLI), a K(ATP) channel blocker, in near full-term lambs with and without CDH. In vivo, pulmonary hemodynamics were assessed by means of pressure and blood flow catheters. In vitro, we used isolated pulmonary vessels and immunohistochemistry to detect the presence of K(ATP) channels in pulmonary tissue. In vivo, pinacidil (2 mg) significantly reduced pulmonary vascular resistance (PVR) in both controls and CDH animals. GLI (30 mg) significantly increased pulmonary arterial pressure (PAP) and PVR in control animals only. In vitro, pinacidil (10 microM) relaxed, precontracted arteries from lambs with and without CDH. GLI (10(-5) microM) did not raise the basal tone of vessels. We conclude that activation of K(ATP) channels could be of interest to reduce pulmonary vascular tone in fetal lambs with CDH, a condition often associated with persistent pulmonary hypertension of the newborn.