Search

The objective of the study was to evaluate the usefulness of 18F-choline PET/CT in biochemically recurrent prostate cancer patients treated with brachytherapy, as well as to assess the changes in therapeutic management derived from its outcome.Retrospective study of 20 patients between 51 and 78 years old, with a history of prostate adenocarcinoma that had been treated with brachytherapy and presented biochemical recurrence (PSA 3.1-12 ng/ml) and staging tests (CT and bone scan) without alterations, were included. The findings visualized in the PET/CT scan with

In castration-resistant prostate cancer (CRPC), early detection of metastases is essential for the selection of treatment, and prevention of bone complications. However detecting incipient metastases remains a challenge as the conventional radiological tests (bone scintigraphy or computerised tomography) lack sufficient sensitivity. Diagnostic imaging techniques are currently available that have greater sensitivity and specificity, but are little used due to shortfalls in the recommendations.To create an algorithm that indicates the most suitable diagnostic imaging techniques for the different M0 CRPC patient profiles based on the scientific evidence.Meetings were held with eight experts in Urology, Pathological Anatomy, Radiodiagnostics and Nuclear Medicine organised by the Andalusian Association of Urology, in which the recommendations and scientific evidence on each of the diagnostic imaging techniques were reviewed.We present the current recommendations for the detection of metastasis in M0 CRPC patients, the patients that would benefit from early detection, and summarise the evidence to support the use of each of the new techniques.Techniques such as

Water management at different decision levels may be supported by the assessment of evapotranspiration (ET) on large spatial scales. In this study, a previously validated approach to estimating unstressed ET, based on the ability of vegetation indices to trace crop growth and thus to derive basal crop coefficients, has been applied to the irrigated areas of the Guadalquivir river basin in southern Spain. Vegetation indices, provided by a series of high spatial resolution satellite images for 2007, 2008 and 2009, supported the assessment of daily to seasonal ET of individual fields, enabling crop-oriented and individual water use to be analysed. The segmentation of the basin into zones with homogeneous climate and crop-growth patterns was the first step towards crop identification based on temporal trends in the Soil-Adjusted Vegetation Index (SAVI). Non-permanent crops were classified with good accuracy. Existing spatial databases of permanent crops enabled land use to be determined. The applied methodology has been compiled in a planning and operational tool named MINARET (MonitorINg irrigated AgricultuRe ET) for routinely monitoring crop water consumption in the irrigated lands of the Guadalquivir basin and it is now available for the Guadalquivir river authority.

Cycled electrodes of CoFe2O4 and CuFe2O4 were analyzed by 57Fe Mossbauer spectroscopy. On decreasing the recording temperature, the spectra evidence the superparamagnetic−ferromagnetic transition of metallic iron formed during the reduction of iron oxides in a lithium cell. In addition, the full reoxidation of iron to the 3+ oxidation state is evidenced after cell recharge. As compared with CoFe2O4, the presence of copper led to three effects: a lower percentage of surface atoms, a higher average oxidation state of surface iron atoms, and smaller metallic particles in the reduced state. The relationships between the Mossbauer spectra and particle size and morphology of the raw spinel materials are studied. The charging process involves an important reordering of iron atoms between bulk and surface locations in CoFe2O4, which leads to minor differences in the spectra of the charged electrodes of both compounds.

In recent years, metallic tin and tin compounds have proven to be interesting electrode materials for lithium batteries. However, detailed information about the mechanism of reaction in phosphate compounds is needed to improve the performance of some previously examined and future electrode materials containing these species. In the present work, powerful techniques for the study of the local environments of the atoms, such as 119Sn Mossbauer spectrometry and 7Li and 31P MAS NMR, are used to obtain basic information on the processes involved during the discharge/reduction of the electrode material. The results allow extracting valuable information about the possible interactions between the participating atoms and the surrounding framework.

To assess the outcome and adverse-effects of the radioisotope synoviorthesis in paediatric and adolescent patients with haemophilia.Prospective study of historical cohort was conducted. A total of 20 consecutive haemophiliacs with a mean age of 13.1 years (range 4-17) were included with a mean follow-up of 64.9 months (range 18-109). The diagnosis of synovitis was established on the basis of clinical follow-up including radiological images (radiography and/or MRI). For evaluation, the classification proposed by Fernandez-Palazzi was used.Patients aged less than 18 years old with haemophilia and more than one haemarthrosis in less than 3 months remaining a chronic synovitis despite prophylactic therapy intensification.Any contraindication for radionuclide synoviorthesis. Twenty-seven radioisotope synoviorthesis with (90)Y-citrate-colloid and/or (186)Re-sulphide-colloid were done. The effectiveness of the procedure was assessed through pre and posttreatment clinical comparison at 6 months after radioisotope synoviorthesis.Nineteen of the 27 synoviorthesis (70.3%) had a good or excellent response and 8 joints (29.7%) had partial response. It was necessary to repeat the procedure in 3 joints in 3 different patients, obtaining in all cases a good or excellent response. We appreciated inflammatory reaction after procedure in 4 cases (14.8%), which improved with analgesics and nonsteroidal anti-inflamatory drugs. None of the patients presented malignant or premalignant lesions during the follow-up.The radionuclide synoviorthesis is a very effective procedure in paediatric and adolescent patients with hemophilia, being a minimally invasive procedure, easy to perform, safe and with minimal side effects.

A high-voltage (5 V) LiCo 0.8 Fe 0.2 MnO 4 electrode with spinel-type structure has been prepared. 57 Fe Mossbauer spectra reveal high-spin Fe 3+ ions in octahedral coordination in the pristine sample, which are oxidized to tetravalent iron ions. Surface treatments with zinc and magnesium have been applied. Zinc and magnesium were homogenously distributed, according to EPMA and mapping analysis, while the spinel structure is maintained. The magnesium and the zinc treatments drive to better electrochemical performance and capacity retention.

Novel compositions Li[LixNi1−x]O2, 0

LiCoxFeyMn2-(x+y)O4 compounds (with x = 0.2, 0.4, 0.8, and 1, and y = 0.0, 0.2, and 0.4) have been prepared. Substitution of manganese by iron and/or cobalt decreases the cubic lattice parameter. The structure of LiCo0.2Fe0.2Mn1.6O4 has been studied in detail by Rietveld refinement of the structure by using data obtained from neutron diffraction measurements. The electrochemical behavior has been tested in Li|LiPF6(EC:DEC)|LiCoxFeyMn2-(x+y)O4 cells, where an increase of the extension of the capacity delivered in the 5-V region and a decrease for the 4-V region was observed when manganese was substituted by iron and/or cobalt. The changes observed in the X-ray diffraction patterns upon lithium extraction have been studied for LiCoMnO4, LiCo0.8Fe0.2MnO4, and LiCo0.2Fe0.2Mn1.6O4. For all these samples a single cubic phase in which the lattice parameter decreases with lithium extraction was observed. The lattice contraction is more marked for Li1-zCo0.2Fe0.2Mn1.6O4 (from 8.187(1) A to ca. 8.06 A) and occurs m...

LiGayCo1−yO2 solid solutions with a layered crystal structure (0 ≤ y < 0.75) were prepared under high-pressure (3 GPa) at 850 °C using a piston–cylinder type apparatus. This is in contrast to the solubility of Ga in the layered LiCoO2 structure at atmospheric pressure, which is strongly limited, and reaches a maximum value of y = 0.1 at 700 °C. The structure of Ga substituted LiCoO2 is characterized by XRD analysis and IR spectroscopy. It has been found that Ga substitutes for Co in the CoO2 layer (3a site), while Li and O are in their normal positions (3b and 6c, respectively). The progressive replacement of Co by Ga leads to a linear increase in the mean M–O bond distance and to a smooth decrease in frequency of the main vibration of the GayCo1−yO2 layer, thus indicating a random Co/Ga distribution. The electrochemical performance of LiGayCo1−yO2 as a cathode material in lithium ion cells has been evaluated in potentiostatic and galvanostatic experiments. The de-intercalation voltage of the LiGayCo1−yO2 solid solutions increases and the reversible capacity decreases with increasing gallium content.

Single-phase oxides with Li[Mn 2− y Co y ]O 4 (0≤ y ≤1) stoichiometry and cubic spinel structure have been prepared by using the lactate precursor method. The oxides were alternatively quenched or slow cooled from 750°C. X-ray diffraction and EPR spectroscopy show that Co and Mn are disordered over 16d spinel sites for samples obtained by air quenching. Local environment of Mn 4+ was assessed by comparison of the observed EPR spectra for Li[Mn 2− y Co y ]O 4 compositions with the EPR signal from Mn 4+ in LiMnCoO 4 and the EPR spectrum of LiMn 2 O 4 . Thus, a local Co/Mn ordering is found for spinels obtained by slow-cooling. The use of these materials as the cathodic active compound in lithium cells reveals a higher capacity but lower capacity retention in the 3–4 V regions for metal-quenched samples as compared with slow-cooled products.

We studied the reduction mechanism of SnO in lithium cells by X-ray absorption near OK and SnL I edge spectroscopy, 119 Sn Mossbauer spectroscopy and X-ray diffraction. The reduction mechanism is complex, involving mixed valence intermediate compounds. In the interval 0≤Li/Sn≤2 the main reaction corresponds to a partial reduction of Sn II , which is partially reversible, regenerating the tin oxide during the charge. For Li/Sn greater than two, LiSn bonds are formed, but SnO interactions are still present. The charge within this interval also partially regenerates tin oxide, but the reversibility does not extend to Li/Sn lower than two. At low voltage and very large depth of discharge, the formation of LiSn alloys and Li 2 O clearly takes place, with negligible SnO interactions.

Powdered solids with LiFe 0.1 Co 0.9 O 2 , LiFe 0.2 Co 0.8 O 2 and LiFe 0.2 Co 0.6 Ni 0.2 O 2 compositions have been prepared by ceramic procedures in the presence of excess lithium. The combined refinement of X-ray and neutron diffraction data reveals that cation substitution takes place in the octahedral sites with an almost complete absence of tetrahedrally coordinated iron. The 57 Fe Mossbauer spectra of these solids agree with this model and show a non-random distribution of Fe and Co ions in octahedral sites.

With the aim of finding new cathode materials for lithium-ion batteries, the synthesis of layered solid solutions with LiFeyCo1−yO2 stoichiometries has been studied in this work. X-ray single phase products were obtained by a ceramic procedure for 0≤y≤0.2. The unit cell dimensions of the powdered solids increase with the iron content. The Rietveld analysis of a sample with y=0.1 using anisotropic thermal parameters led to RBRAGG=3.37. The hexagonal unit cell parameters of this solid were a=2.8271(1) A and c=14.1266(7) A. The site occupancy used in the Rietveld procedure was: (FeT0.0086)6c[Li0.9868FeO0.0046]3b[Li0.0132Co0.9000FeO0.0868]3aO2 according to the intensity of the signals observed in the Mossbauer spectrum. This consists of one intense (87%) quadrupole split signal with isomer shift of ca. 0.316(3) mm/s is ascribable to Fe(III) replacing cobalt in the CoO2 layers. Two weaker quadrupole signals result from small amounts of iron in octahedral 3b and pseudotetrahedral 6c sites of the LiO2 layers. The presence of pseudotetrahedral iron puts obstacles to the lithium ion diffusivity. In consequence, the electrochemical spectra evidence an increased cell polarization as increases. The lithium extraction at the end of the first charge decreases with iron content, with a maximum of 0.6 Li per formula for y=0.1. The introduction of nickel in the composition of these solids may be useful to improve the electrochemical performance of the solid solutions. Ternary systems show an improved electrochemical behaviour.

The past decade has seen an important development of materials for high-performance energy storage systems. Particularly, the field of electrode materials for advanced lithium batteries has attracted the interest of numerous researchers. Petroleum coke samples of different origins and heat treated at different temperatures below 3100 K have been studied by spectroscopic and electrochemical procedures. According to {sup 13}C and {sup 1}H magic-angle spinning (MAS) nuclear magnetic resonance (NMR), infrared (IR), and electron paramagnetic resonance (EPR) data, aromatic compounds and surface OH groups are present in green coke samples. The preparation of CMB (combustible) sample from 1673 K leads to a low-temperature graphitization process, as shown by the occurrence of multiphase products containing both turbostatic and graphitized solid. This process is accompanied by the loss of aromatic compounds and surface hydroxyls. The optimization of the lithium intercalation electrodes based in the green coke materials was carried out by thermal treatment at 1023 K under dynamic vacuum conditions. Such pretreatment of the electrode material leads to marked enhancement of reversible capacities without the higher temperatures usually required for other soft carbon materials. Finally, the results of {sup 6}Li MAS NMR and EPR have been correlated with the experimental determination of lithiummore » diffusion coefficients and surface properties. On the basis of these results, spin resonance spectroscopies are found to be a powerful tool to discern between the different petroleum coke samples to select the active electrode material with best performance.« less

Step potential electrochemical spectroscopy (SPES), 6Li magic angle spinning nuclear magnetic resonance (MAS NMR) and Ni3+ electron paramagnetic resonance (EPR) probes were used to examine the effect of lithium extraction and reinsertion in the structure of pseudo-spinel and layered modifications of LiCoO2 used as cathode materials in 4 V lithium-ion batteries. Current relaxations at each step of the SPES experiment show a similar lithium ion diffusivity in both structural modifications during cell charge. The different electrochemistry of pseudo-spinel and layered LiCoO2 can be attributed to the structural instability of the delithiated pseudo-spinel phase as compared to the layered modification. EPR studies of cycled electrodes based on pseudo-spinel LiCoO2 give direct evidence for the appearance of Co2+ in tetra coordination. For layered LiCoO2, the 6Li NMR line broadening and the spin lattice relaxation of Ni3+ spin probes reveal the internal stresses induced in the solid matrix by lithium extraction and reinsertion reactions.

The chemical environment of Sb atoms in misfit layer sulfides (SbS)pTS2 (T = Nb, Ti and Ta) was examined by using 121Sb Mossbauer spectroscopy (MS) and X-ray photoelectron spectroscopy (XPS). 121Sb Mossbauer spectra exhibited an asymmetric profile that can be interpreted by assuming two different coordination numbers for trivalent Sb ions. However, these data do not give evidence for the presence of a significant Sb atom fraction of valence similar to metallic antimony as reported by X-ray single-crystal structure calculations. Sb 3d peak profiles were found to be highly symmetric and to suggest the presence of a single electronic state for Sb atoms within the SbS lattice. Although the binding energy of Sb 3d electrons in Sb-containing misfit layer sulfides was found to coincide with that in Sb2S3, the Wagner−Auger parameter values are intermediate between those reported for Sb2S3 and metallic Sb.

Ni3+ EPR measurements were used to investigate the electronic structure and ion distribution of Li1−x(NiyCo1−y)1+xO2 (y = 0.13 and 0.8 ≤ y ≤ 1.0) solid solutions prepared between 450 and 800°C. The data on the Ni3+ distribution were obtained from the analysis of the EPR line width. The results show that a transition from non-random to a random Ni Co distribution in the NiyCo1−yO2 slabs occurs between 650 and 750°C. 6Li solid state MAS NMR and magnetic susceptibility measurements are in good correspondence with this interpretation.

Step potential electrochemical spectroscopy data of lithium anode cells using VSe2−ySy(0≤y≤0.5) compounds as cathode material and LiClO4 solutions in PC as electrolyte were studied. On increasing y, a lower extension of the intercalation process was observed, due to the loss of a second insertion step corresponding to lithium ion occupancy of tetrahedral sites. In contrast, the reaction rate increased with sulfur content. VSe2−ySy/LiCoO2 lithium-ion cells were cycled to test the electrochemical behaviour of the vanadium chalcogenides as anodic material. A better capacity retention was observed for y = 0.3. The effect of current density on the performance of the cells was also evaluated.

A new method for the preparation of ultrafine LiCoO2 with a layered crystal structure was developed, which consists in thermal pyrolysis of homogeneous lithium-cobalt-citrate precursors. Atomic scale mixing of Li and Co is achieved by citric acid acting as a chelating agent. Electron spectroscopy of concentrated Li-Co-citrate solutions with Li:Co:Cit=1:1:1 and Li:Co:Cit=1:1:2 reveals that the predominant species at pH=7 are [Co(C6H5O7)]− and [Co(C6H5O7)2]4− complexes. Freeze-drying of the two types of solutions leads to the formation of LiCo(C6H5O7).nH2O and (NH4)3LiCo(C6H5O7)2.nH2O precursors, where Co2+ ions are complexed by one and two triionized citrate ions, respectively, and Li+ ions serve as counter ions. Between 400–600 °C, the thermal decomposition of these metal-citrate precursors yields LiCoO2 with layered and pseudo-spinel structure, the proportion between them being depending on: (i) the Co/citrate ratio; (ii) the concentration of the freeze-dried solution; (iii) the heating rate. At 400 °C, the most defectless layered LiCoO2, consisting of hexagonal individual particles with dimensions of 120–170 nm, is a product of the bis-citrate decomposition with a slow heating rate. For this sample, heating up to 600 °C does not affect the crystal size dimensions. For ultrafine layered LiCoO2 and LiCoO2 obtained by solid state reaction at high-temperatures (850 °C), the deintercalation and intercalation reactions proceed in the 3.95 – 3.99 and 3.86 – 3.88 voltage intervals, respectively. For defect trigonal LiCoO2, additional oxidation and reduction peaks at 3.7 – 3.8 and 3.4 – 3.5 V were observed. We did not succeed in preparing monophase LiCoO2 with pseudo-spinel structure.

X-Ray diffraction and electron microscopy studies of several cokes prepared from petrol of different origins but heat treated to the same temperature, 1400°C, reveal significant divergences in phase homogeneity. These in turn have a direct effect on the lithium intercalation properties of these materials. The presence of crystalline phase in some coke samples leads to larger capacities and a lower cyclability of the insertion behaviour. The presence of impurities and the effect of additives on the electrochemical behaviour of the intercalation electrodes are also evaluated.

The misfit layer sulfide of composition (PbS)1.18(TiS2)2has been studied as a host material for the intercalation of sodium. The discharge curve profile using propylene carbonate (PC) as the solvent of electrolyte showed that the intercalation process is complex with the appearance of an extended plateau which suggests the formation of a multiphase region. In fact, an intermediate phase of sodium content 0.2 mol per formula unit, with basal spacing of 29.9 A, which exceeds by 12.4 A the repeating unit PbS–TiS2–TiS2, has been observed. This result is interpreted on the basis of solvent cointercalation. PC molecules are located at the interlayer region defined at the interface TiS2–TiS2. The increase in the sodium content promotes the release of PC molecules out of the layers. The interlayer expansion of the new phase formed is similar to that observed upon intercalation with sodium naftalide and is consistent with the location of sodium ions in the interstitial sites defined by two consecutive sulfur slabs. Under room conditions this phase absorbs water. The final expansion of ca. 6 A is consistent with a bilayer hydration process.

Acid treatment at 0°C of Li 1-x (Ni y Co 1-y ) 1+x O 2 solid solutions yields delithiated well crystalline oxides Li 0.5 (Ni y Co 1-y ) 1+x O 2 which do not contain protons. For the nearly stoichiometric nickel-rich oxides, removal of more than 20% of the lithium leads to a monoclinic distortion of the rhombohedral unit cell. Electron paramagnetic resonance (EPR) of low-spin Ni 3+ ions shows that for up to 0.2 extracted lithium, the generated Ni 4+ ions are statistically distributed in the NiO 2 layers while above 0.2 extracted lithium the Ni 4+ ions trend to order. During acid delithiation the oxidation of Ni 3+ to Ni 4+ ions proceeds prior to the oxidation of Co 3+ to Co 4+ as for a nonaqueous electrolyte. Discharge-charge cycles of lithium cells using acid-delithiated oxides as cathode materials show a significant improvement of reversibility compared with the charge-discharge cycles of the corresponding pristine samples

Three experiments were conducted in greenhouse under hydroponic conditions to study the response of wheat to: i) different ammonium/nitrate (NH4/NO3) ratios, ii) the application of NH4 during different phenological states, and iii) the addition of calcium carbonate (CaCO3) for maximum replacement of NO3 by NH4. Small amounts of NH4 considerably increased yield and grain quality. The best response was observed with a 2/5 ratio NH4/NO3 (meq/L). The application of small fractions of NH4 during grain fill increased production. Dry matter (DM) production decreased when large quantities of NH4 were applied. However, when CaCO3 was used in amounts similar to those of NH4, it was possible to neutralize the acidifing effect of reduced nitrogen (N) and to recuperate DM and grain production, thus increasing the harvest index.

Multiple Endocrine Neoplasia type 1 syndrome (MEN1) is characterized by the presence of tumors in parathyroid glands, anterior pituitary gland, endocrine pancreas and duodenum. However, other tumors may also occur. One of them is the carcinoid tumor, which in this context, is more common in the gastrointestinal tract. Less common is the presence of carcinoid tumors of bronchial origin, which with histologic confirmation, may occur in 5-8% of cases and that appears more frequently in patients with hypergastrinemia. We report a patient with MEN1 syndrome, hypergastrinemia and an incidental finding in a somatostatin receptor scintigraphy of an unsuspected bronchial carcinoid tumor that was confirmed histologically.

Monophase Li1-x(NiyCo1-y)1+xO2 oxides (0 ≤ y ≤ 0.4 and 0.8 ≤ y ≤ 0.9) with a layered structure (R3m space group) have been prepared by interaction of (NiyCo1-y)3O4 (0 ≤ y ≤ 0.4) and NiyCo1-yO (0.8 ≤ y ≤ 0.9) with LiOH at low temperature (450°c). As in the case of high-temperature analogues, cobalt substitution for nickel stabilizes the Ni3+ ions and improves the two-dimensionality of the crystal lattice. Acid treatment of LT and HT oxides leads to a partial dissolution of the solid and to removal of lithium and "impurity" cobalt and/or nickel from LiO2 layers of the trigonal framework. For cobalt-rich oxides, the ion extraction is accompanied by partial Li+/H+ exchange, especially for LT samples. Acid-delithiated oxides are studied as cathode materials in lithium batteries. The resulting cells show a high value of the initial voltage (4 V), which allows a direct discharge of the cell without previous charge. For LT samples, the discharge and charge processes occur at lower voltage (especially for Co-rich oxides) and the reversibility of the cell is lower as compared to that of HT analogues. The better reversibility of the cell in the 4.0-3.2 V range is found for HT Ni-rich oxide. The composition of the acid-treated oxides can be recovered without an enhancement polarization of the cell. XRD analysis and IR spectroscopy show good reversibility of lithium insertion and extraction reactions by chemical and electrochemical procedures.

This study has aimed to analyze the evolution of patients diagnosed with differentiated thyroid carcinoma (DTC) with a negative (131)I-Na whole body scan (WBS), high levels of serum thyroglobulin (Tg) and negative (18F)fluorodeoxyglucose positron emission tomography (PET-FDG) study.Twenty-three patients diagnosed and treated for DTC were studied retrospectively. Patients were aged between 23 and 83 and had shown, between January 2001 and December 2002, negative WBS, Tg values in a range of suspected recurrence or metastasis (Tg2 ng / mL with thyroid hormone withdrawal) and a negative PET-FDG study. The patients were monitored clinically, radiologically and analytically for a minimum period of 4 years. After this, a new evaluation was made of their state of disease with a control WBS, also observing the evolution of Tg. All WBS were performed with a 185 MBq diagnostic dose of (131)I-Na.In 18/23 patients, Tg decreased and in 5 it increased. Four patients (17%) were free of active disease (negative WBS Tg2 ng / mL). A total of 16 patients (70%) were free of disease according to the WBS but had elevated Tg. Three patients (13%) had disease and high levels of Tg, two of them with positive WBS and the third with (99m)Tc-MIBI scan and CT positive.Most patients with a negative WBS, high Tg serum levels and negative FDG PET had good evolution, with descending Tg levels, normal levels even being reached in a significant percentage of them.

The integration of time series of high-resolution remote sensing images in the FAO crop evapotranspiration (ET) model is receiving growing interest in the last years, specially for operational applications in irrigated areas. In this study, a simplified methodology to estimate actual ET for these areas in large watersheds was developed. Then it was applied to the Guadalquivir river watershed (Southern Spain) in the 2007 and 2008 irrigation seasons. The evolution of vegetation indices, obtained from 10 Landsat and IRS images per season, was used for two purposes. Firstly, it was used for identifying crop types based on a classification algorithm. This algorithm used training data from a screened subset of the information declared by farmers for EU agriculture subsidies purposes. Secondly, the vegetation indices were used to obtain basal crop coefficients (K cb , the component of the crop coefficient that represents transpiration). The last step was the parameterization of the influence of evaporation from the soil surface, considering the averaged effect of a given rain distribution and irrigation schedule. The results showed only small discrepancies between the crop coefficients calculated using the simplified model and those calculated based on a soil water balance and the dual approach proposed by FAO. Therefore, it was concluded that the simplified method can be applied to large irrigation areas where detailed information about soils and/or water applied by farmers lacks..

The aim of this study is to determine the diagnostic reliability of the renogram with diuretic stimulus simultaneously at the administration of the dose, comparing two groups of 59 patients each one (F0 and F+10), to select patients for surgery.This is an retrospective study about two groups of 59 patients to whom the diuretic renogram was carried out by stimulus (furosemide), by suspicion of ureteropelvic or vesicoureteral obstruction, using (99m)Tc-Mercaptoacetylglicine. In the first one, the study was conducted applying the diuretic stimulus 600 seconds after the administration of the dose of the radiotracer (F+10). In the second one it was carried out simultaneously to the administration (F0). For the interpretation there was used the visual analysis, the parameters of the curves and the percentage of elimination after modification by the severity and micturition. Statistical analysis of the information was made.The F+10 renogram shows a sensitivity of 96,7%, specificity of 96,1%, positive predictive value of 90,6%, and a negative predictive value of 98,6%. The F0 renogram shows a sensitivity of 95,2%, specificity of 98,9%, positive predictive value of 95,2%, and a negative predictive value of 98,9%.The performance of renogram by means of the administration of diuretic stimulus at the same time as the administration of the radiotracer is a useful and comfortable method in paediatric patients, not supposing a significant wastage in the parameters of efficiency of the test in the patients selection for surgery.

Two CoFe 2 O 4 samples prepared at 600 and 1000°C have been subjected to galvanostatic cycling in lithium test cells. 57 Fe Mossbauer spectra have been analyzed to elucidate the possible causes of capacity fading during the first cycles. 57 Fe conversion electron Mossbauer spectroscopy has been applied to distinguish between bulk and surface iron locations. This technique revealed the presence of reduced iron atoms near the surface of the sample annealed at 1000°C. Their suitable accessibility to lithium may explain the better capacity retention observed for a large number of cycles.

To verify the existence of patients with treated differentiated thyroid cancer (DTC) with negative 131I whole-body scanning (WBS) and high serum thyroglobulin (Tg) in the follow-up who evolve towards normalization without other therapy interventions.Retrospective revision of the periodic examinations established in the protocol for patients with DTC, analyzing the levels of Tg found with IRMA annually in those with hormonal treatment and every 1-5 years in absence of previous hormonal treatment to WBS. Minimum surveillance of 2 years. Those who had elevated levels of Tg and WBS and other negative imaging tests in their course were selected. The characteristics of the patients selected were analysed in those whose Tg levels evolved to normalization without specific medical or surgical treatment (Group I) and those who did not reach normalization of Tg (Group II).A total of 130 patients (17.93 %) with high levels of Tg and negative WBS were detected. Group I: 31 patients (4.28 %), 11 men and 20 women; average age at the moment of the diagnosis of 33.4 years (rank: 5-60); average surveillance: 12.4 years (+/- 7.4).27 papillary and 4 follicular carcinoma. Average ablation dose: 3.260 GBq (88,1 mCi); average total I131 dose: 6.850 GBq (185.13 mCi). Tg normalization average time: 8.2 years. Group II: 99 patients (13.65 %), 27 men and 72 women. Average age of 40.4 years (rank: 7-76). Average surveillance: 9.8 years.86 papillary and 13 follicular carcinoma. Average ablation dose: 3.266 GBq (88.28 mCi); average total 131I dose: 9.363 GBq (253,06 mCi). Two of the patients in group I had negative PET-FDG. There were 13 patients in whom progressive reduction of the levels of thyroglobulin without reaching normalization with negative PET-FDG was detected.In patients with radiated DTC, deferred normalization of the levels of the serum thyroglobulin is possible. Empirical treatments cannot be considered the only factor that contributes to this result, which can occur without the administration of high-doses of 131I.

To determine the value of the use of radio-iodine scanning diagnostic and radio-iodine therapy during the follow-up of advanced differentiated thyroid cancer without stopping thyroid hormone suppression therapy.We performed 7 radio-iodine scans and 4 radioiodine therapies in 5 men and 1 woman, aged 39 to 79 years. Five patients had papillary thyroid cancer and one follicular thyroid cancer. Human recombinant thyrotropin was given intramuscularly at a dose of 0.9 mg/ml once a day for two days. Twenty-four hours after the second dose, serum thyrotropin, thyroglobulin (Tg) and thyroglobulin autoantibodies were measured and each patient was given 2 mCi of 131I in postsurgery scans and 5 mCi of 131I in patients previously treated with 131I. Whole-body scans were obtained within 54 hours of injection and in the cases of diagnostic uncertainty a second scan was performed 72 hours after the injection.Four scans were positive and two were negative. One positive scan patient was not treated due to a serious clinical condition. An effective increase of serum TSH was observed in all 6 patients. Four patients had an effective increase of serum Tg; the other 2 cases had a decrease of serum Tg: One case was undifferentiated and in the other case the mass was smaller after surgery.rhTSH is an effective means of stimulating TSH levels and allowing scan and/or radioiodine treatment. rhTSH has no significant adverse effects. The use of rhTSH avoids all the disadvantages of hypothyroidism and maintains quality of life.

Since the launch in 1990 of the first commercial lithium-ion batteries based on LiCoO2 cathode materials, a considerable progress has been accomplished in the field of the solid state chemistry and electrochemistry of lithium-manganese spinels, which are thought to be alternative cathode materials. In order to improve the cycling stability of lithiummanganese spinels, the partial replacement of Jahn-Teller Mn3+ ions by transition metal ions or electrochemically inactive metal ions has been successfully applied.

First studies of the ternary system SnSe-Bi(2)Se(3) developed in 1960s and 1970s have revealed the existence of a nonstoichiometric trigonal phase with a wide range of compositions. In this study, an almost stoichiometric phase, corresponding to the composition SnBi(4)Se(7), has been identified and isolated. The structure has been determined by X-ray diffraction and the local environment of Sn atoms analyzed by Mössbauer spectroscopy. This phase has a rhombohedral structure, space group Rthremacr;m, with hexagonal lattice parameters a = 4.1602(5) Å and c = 38.934(3) Å. The unit cell contains three slabs, each one composed of seven atomic layers according to the sequence Se-Bi-Se-(Bi,Sn)-Se-Bi-Se. Bismuth atoms partially occupy two sites, 3a (0, 0, 0) and 6c (0, 0, z) with z = 0.4285, while tin atoms partially occupy only one site, 3a. Selenium atoms are placed in two different 6c sites, with z(1) = 0.1350 and z(2) = 0.7108.

Con el objetivo de estimar la eficiencia de absorción de fósforo en un genotipo de trigo y cuatro genotipos de triticale en un Andisol y un Phaeozem, se realizó un experimento en invernadero con aplicación de fósforo soluble (superfosfato triple) e insoluble en agua (roca fosfórica). Se evaluó materia seca de parte aérea, raíz y grano, y, con ello, se determinó el índice de eficiencia de fósforo. En ambos suelos, los triticales produjeron el mayor rendimiento de grano, materia seca de parte aérea y raíz que el trigo. La respuesta de trigo y triticale a la aplicación de superfosfato triple fue mayor en los dos suelos, en comparación con la roca fosfórica. La roca fosfórica sólo fue efectiva en el Andisol. La acumulación de fósforo en el tejido vegetal y el índice de eficiencia de este elemento fueron mayores para los triticales, en cerca de 50%, respecto a los trigos en ambos suelos y para los dos tipos de fuentes de fósforo aplicados.

Con la finalidad de determinar las diferencias en el contenido de N, P, K, Ca, Mg, B y Zn en hojas e inflorescencias de aguacatero (Persea americana Mill.) `Colín V-33´, `Fuerte´ y `Hass´, y conocer la distribución de dichos nutrimentos en las inflorescencias de los tres cultivares, se realizó el presente trabajo en Coatepec Harinas, México. La concentración foliar de los nutrimentos en los tres cultivares fue similar, con excepción del B cuya concentración en `Fuerte´ (50.25 mg kg-1) fue superior a la de los otros dos cultivares. La comparación nutrimental de las inflorescencias de los tres cultivares mostró diferencia sólo en el contenido de Mg, las inflorescencias de `Colín V-33´ presentaron la mayor concentración (0.27%). Las inflorescencias de los tres cultivares presentaron mayor concentración de P y K y menor de Ca y Mg que la de las hojas. La distribución de todos los nutrimentos en la panícula (sin considerar al brote) fue homogénea. La concentración nutrimental en el brote varió entre cultivares.

cited By 10; International audience; 119Sn Moessbauer spectroscopy, X-ray diffraction and electrochemical experiments were carried out to characterize the reaction mechanism of lithium with spinel phases of the Cu2S-In2S3-SnS2 system. This analysis reveals an irreversible part of the mechanism linked to the reduction of the cations involving a spinel to rocksalt transformation followed by a structural breakdown, and a reversible part linked to the formation of lithium-metal alloys. The electrochemical investigation has shown interesting reversible capacities for these materials, and their possible use as anode materials in lithium-ion cells.

Spinel oxides with LiM x Mn 2 - x O 4 (M = Fe, Ni) formula are known to be interesting electrode materials for lithium-ion batteries. These materials show a significant near 5 V capacity, which results from changes in the oxidation state of the transition metal M. In this work, compounds of the LiNi 0 . 5 - y Fe y Mn 1 . 5 O 4 series have been characterized. The charge/discharge curves of lithium test cells using these compounds as active electrode material show two plateaus. The first one, below 4.5 V, is ascribed to a Mn 4 + /Mn 3 + pair, while the second, between 4.5 and 5.1 V, can be attributed to Ni 4 + /Ni 2 + and Fe 4 + /Fe 3 + pairs. High capacity and excellent capacity retention is obtained for some compositions with intermediate y values. The suppression of the multiphase mechanism of insertion-deinsertion commonly found for LiNi 0 . 5 Mn 1 . 5 O 4 by iron substitution is evidenced for compositions in the 0 < y ≤ 1 range. The change in mechanism is correlated with the improvement in electrochemical performance. Moreover, cation distribution, which includes the presence of iron in the tetrahedral sites of the spinel structure, stabilizes the solid upon prolonged cycling.

New mixed spinel oxides with LiNi y Co 1-2y Mn 1+y O 4 (y = 0.2, 0.3, and 0.4) stoichiometries have been synthesized under different annealing temperatures and tested as cathode materials in lithium batteries. High-purity cubic spinel-phase products were obtained between 700 and 950°C, in which the lattice parameter increases with nickel content. The structural and textural properties of the powder samples were studied by X-ray diffraction (XRD) and scanning electron microscopy and correlated with the electrochemical behavior. From these experiments, the best performance was obtained for LiNi 0.4 Co 0.2 Mn 1 404 cathodes with 1-5 μm regular octahedral particles, which developed capacity values close to 120 mAh/g with a good capacity retention. The ex situ XRD patterns of the partially charged electrodes were characteristic of a single cubic phase in which lattice parameter decrease with lithium extraction for all compositions.

Tin hydrogen phosphate (SnHPO 4 ) has been tested as an electrode material in Li cells. It exhibits a high capacity for the first discharge and a capacity of ca. 200 mAh g(Sn) -1 after 25 cycles at 20°C. The Li-to-network interaction during the first discharge has been followed using X-ray diffraction and 7 Li, 31 P magic-angle spinning nuclear magnetic resonance. The results obtained allow us to propose a Li-reaction mechanism for this phase, based on the formation of Sn and Li 3 PO 4 in the first stage followed by reversible Sn/Li alloying.

Etude de la pyrolyse sous vide. Cinetique du 1er ordre: vitesse de decomposition proportionnelle a la quantite de reactif non decompose