924 resultados para intermediate forms


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Nitrogen fertilization is a major component of the cost of agricultural production, due to the high cost and low efficiency of fertilizers. In the case of urea, the low efficiency is mainly due to losses by volatilization, which are more pronounced in cultivation systems in which plant residues are left on the soil. The objective of this work was to compare the influence of urea coated with sulfur or boric acid and copper sulfate with conventional N fertilizers on N volatilization losses in sugar cane harvested after stubble burning. The sources urea, sulfur-coated urea, urea coated with boric acid and copper sulfate, as well as nitrate and ammonium sulfate, were tested at amounts containing N rates of 120 kg ha-1 N. The integration of new technologies in urea fertilization can reduce N losses by volatilization. These losses were most reduced when using nitrate and ammonium sulfate. The application of a readily acidified substance (boric acid) to urea was more efficient in reducing volatilization losses and nutrient removal by sugar cane than that of a substance with gradual acidification (elemental sulfur).

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The application of animal manure to soil can increase phosphorus availability to plants and enhance transfer of the nutrient solution drained from the soil surface or leached into the soil profile. The aim of this study was to evaluate the effect of successive applications of organic and mineral nutrient sources on the available content, surface runoff and leaching of P forms in a Typic Hapludalf in no-tillage systems. Experiment 1 was set up in 2004 in the experimental area of UFSM, in Santa Maria (RS, Brazil). The treatments consisted of: control (without nutrient application) and application of pig slurry (PS), pig deep-litter (PL), cattle slurry (CS), and mineral fertilizers (NPK). The rates were determined to meet the N crop requirements of no-tillage black oat and maize, grown in the 2010/2011 growing season. The soil solution was collected after each event (rain + runoff or leaching) and the soluble, particulate and total P contents were measured. In November 2008, soil was collected in 2 cm intervals to a depth of 20 cm, in 5 cm intervals to a depth of 40 cm, and in 10 cm intervals to a depth of 70 cm. The soil was dried and ground, and P determined after extraction by anion exchange resin (AER). In experiment 2, samples collected from the Typic Hapludalf near experiment 1 were incubated for 20, 35, 58, 73 and 123 days after applying the following treatments: soil, soil + PS, soil + PL, soil + CS and soil + NPK. Thereafter, the soil was sampled and P was analyzed by AER. The applications of nutrient sources over the years led to an increase in available P and its migration in the soil profile. This led to P transfer via surface runoff and leaching, with the largest transfer being observed in PS and PL treatments, in which most P was applied. The soil available P and P transfer via surface runoff were correlated with the amounts applied, regardless of the P source. However, P transfer by leaching was not correlated with the applied nutrient amount, but rather with the solution amount leached in the soil profile.

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Phosphorus fractions play a key role in sustaining the productivity of acid-savanna Oxisols and are influenced by tillage practices. The aim of this study was to quantify different P forms in an Oxisol (Latossolo Vermelho-Amarelo) from the central savanna region of Brazil under management systems with cover crops in maize rotation. Three cover crops (Canavalia brasiliensis, Cajanus cajan (L.), and Raphanus sativus L.) were investigated in maize rotation systems. These cover crops were compared to spontaneous vegetation. The inorganic forms NaHCO3-iP and NaOH-iP represented more than half of the total P in the samples collected at the depth of 5-10 cm during the rainy season when the maize was grown. The concentration of inorganic P of greater availability (NaHCO3-iP and NaOH-iP) was higher in the soil under no-tillage at the depth of 5-10 cm during the rainy season. Concentrations of organic P were higher during the dry season, when the cover crops were grown. At the dry season, organic P constituted 70 % of the labile P in the soil planted to C. cajan under no-tillage. The cover crops were able to maintain larger fractions of P available to the maize, resulting in reduced P losses to the unavailable pools, mainly in no-tillage systems.

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The action of rain and surface runoff together are the active agents of water erosion, and further influences are the soil type, terrain, soil cover, soil management, and conservation practices. Soil water erosion is low in the no-tillage management system, being influenced by the amount and form of lime and fertilizer application to the soil, among other factors. The aim was to evaluate the effect of the form of liming, the quantity and management of fertilizer application on the soil and water losses by erosion under natural rainfall. The study was carried out between 2003 and 2013 on a Humic Dystrupept soil, with the following treatments: T1 - cultivation with liming and corrective fertilizer incorporated into the soil in the first year, and with 100 % annual maintenance fertilization of P and K; T2 - surface liming and corrective fertilization distributed over five years, and with 75 % annual maintenance fertilization of P and K; T3 - surface liming and corrective fertilization distributed over three years, and with 50 % annual maintenance fertilization of P and K; T4 - surface liming and corrective fertilization distributed over two years, and with 25 % annual maintenance fertilization of P and K; T5 - fallow soil, without liming or fertilization. In the rotation the crops black oat (Avena strigosa ), soybean (Glycine max ), common vetch (Vicia sativa ), maize (Zea mays ), fodder radish (Raphanus sativus ), and black beans (Phaseolus vulgaris ). The split application of lime and mineral fertilizer to the soil surface in a no-tillage system over three and five years, results in better control of soil losses than when split in two years. The increase in the amount of fertilizer applied to the soil surface under no-tillage cultivation increases phytomass production and reduces soil loss by water erosion. Water losses in treatments under no-tillage cultivation were low in all crop cycles, with a similar behavior as soil losses.

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Introduction Swallowing difficulties, or dysphagia, can occur in anyage group, although it is most common among elderly people. It canaffect patients' ability to take solid oral dosage forms, thus compromisingmedication adherence. Although literature is poor, availabledata show that prevalence in the general population ranges from 25 to60%. Prevalence in community pharmacies needs to be explored.Materials & Methods Community pharmacies were recruited from arandom selection in three Swiss states: Basel-Stadt (BS), Basel-Landschaft (BL) and Lausanne (LA). Patients' ability to swallowsolid oral medications was enquired with a semi-structured interview;the interviewer spent 4 h in each included pharmacy. Each consecutivepatient (18 years and older) entering the pharmacy with aprescription for at least 3 different solid oral forms was enrolled.Study was approved by the Lausanne ethics committee.Results Sixty pharmacies took part in the study (20 in BS, 10 in BL,30 in LA) between March and May 2010. Patient inclusion rate was77.8% (410/527). Prevalence of swallowing disorders was 22.4% (92/410). Patients with swallowing disorders were older (mean age: 67.5± 16 years vs. 63.0 ± 14 years, range 19-96; p = 0.03) and moreoften women (69.6% vs. 59.1%; Chi2 = 3.3, p = 0.04) than patientswithout swallowing disorders. They had on average 4.6 ± 2.7 drugswith a mean number of 5.5 ± 3.3 tablets or capsules to take daily,which didn't differ from the number of drugs taken by patientswithout swallowing difficulties (4.9 ± 2.5 drugs and 5.9 ± 3.5 tablets;n.s.). The difficulty was mainly related to the big size (63%) orthe quality of pill coating (rough, sticky, 14%). Twenty-one patients(37.5%) stated that their swallowing disorders resulted in nonadherence, rated as rarely (12 patients), sometimes (6 patients), veryoften (1 patient) or always (2 patients). According to patients, nopharmacist and only 2 physicians enquired about patients' swallowingissue.Discussion & Conclusion Swallowing difficulties are frequent amongpatients in community pharmacies in Switzerland with an estimatedprevalence of 22%. The problem resulted in non adherence or partialadherence in at least 35% of these patients. However, pharmacists andphysicians did not routinely inquire about the disorder. Guidelinesshould be developed for promoting systematic approaches of patientsin community pharmacies.

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ABSTRACT The use of fire to prepare agricultural areas is a technique still used by small farmers in eastern Amazon. This type of management changes the dynamics of soil nutrients, especially phosphorus, which constitutes the most limiting nutrient for crop production in tropical soils. This study was carried out to evaluate changes in phosphorus forms in an Argissolo Amarelo Distrófico (Ultisol) submitted to burning and trituration of secondary forest in eastern Amazon. The evaluated systems were: slash-and-burn of vegetation; slash-and-mulch of vegetation; and secondary vegetation. The labile, moderately labile, moderately recalcitrant, available and total phosphorus fractions were assessed at the soil depths of 0.00-0.05, 0.05-0.10 and 0.10-0.20 m. The results showed a predominance of soluble P in acid (moderately labile P) over other forms in all management systems. The management systems influence the content and distribution of the forms of P, where the slash-and-mulch system presented the prevalence of the labile fraction, and the slash-and-burn system contained less labile forms. The slash-and-mulch system favored the accumulation of labile P and total organic P.

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Using isolated, in situ, single-pass perfused rat livers, incubations of freshly isolated hepatocytes, and sinusoidal membrane-enriched vesicles, we and others have shown the saturability of transport (efflux) of hepatic glutathione (GSH). These observations have implicated a carrier mechanism. Our present studies were designed to provide further evidence in support of a carrier mechanism for hepatic GSH efflux by demonstrating competition by liver-specific ligands which are taken up by hepatocytes. Perfusing livers with different substances, we found that: (a) sulfobromophthalein-GSH (BSP-GSH) had a dose-dependent and fully reversible inhibitory effect on GSH efflux, while GSH alone did not have any effect; (b) taurocholate had no inhibitory effect; (c) all of the organic anions studied, i.e., BSP, rose bengal, indocyanine green, and unconjugated bilirubin (UCB), manifested potent, dose-dependent inhibitory effects, with absence of toxic effects and complete reversibility of inhibition in the case of UCB. The inhibitory effects of UCB could be overcome partially by raising (CoCl2-induced) hepatic GSH concentration. Because of the physiological importance of UCB, we conducted a detailed study of its inhibitory kinetics in the isolated hepatocyte model in the range of circulating concentrations of UCB. Studies with Cl- -free media, to inhibit the uptake of UCB by hepatocytes, showed that the inhibition of GSH efflux by UCB is apparently from inside the cell. This point was confirmed by showing that the inhibition is overcome only when bilirubin-loaded cells are cleared of bilirubin (incubation with 5% bovine serum albumin). Using Gunn rat hepatocytes and purified bilirubin mono- and diglucuronides, we found that both UCB and glucuronide forms of bilirubin inhibit GSH efflux in a dose-dependent manner. We conclude that the organic anions, although taken up by a mechanism independent of GSH, may competitively inhibit the carrier for GSH efflux from inside the hepatocyte.

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The bacterial insertion sequence IS21 contains two genes, istA and istB, which are organized as an operon. IS21 spontaneously forms tandem repeats designated (IS21)2. Plasmids carrying (IS21)2 react efficiently with other replicons, producing cointegrates via a cut-and-paste mechanism. Here we show that transposition of a single IS21 element (simple insertion) and cointegrate formation involving (IS21)2 result from two distinct non-replicative pathways, which are essentially due to two differentiated IstA proteins, transposase and cointegrase. In Escherichia coli, transposase was characterized as the full-length, 46 kDa product of the istA gene, whereas the 45 kDa cointegrase was expressed, in-frame, from a natural internal translation start of istA. The istB gene, which could be experimentally disconnected from istA, provided a helper protein that strongly stimulated the transposase and cointegrase-driven reactions. Site-directed mutagenesis was used to express either cointegrase or transposase from the istA gene. Cointegrase promoted replicon fusion at high frequencies by acting on IS21 ends which were linked by 2, 3, or 4 bp junction sequences in (IS21)2. By contrast, cointegrase poorly catalyzed simple insertion of IS21 elements. Transposase had intermediate, uniform activity in both pathways. The ability of transposase to synapse two widely spaced IS21 ends may reside in the eight N-terminal amino acid residues which are absent from cointegrase. Given the 2 or 3 bp spacing in naturally occurring IS21 tandems and the specialization of cointegrase, the fulminant spread of IS21 via cointegration can now be understood.

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Describimos la distribución espacial de individuos de Pinus uncinata clasificados según su forma de crecimiento y tamaño en dos ecotonos poco perturbados del límite altitudinal del árbol situados en los Pirineos Centrales españoles (Ordesa, O; Tessó, T). En cada sitio situamos una parcela rectangular (30 140 m), que incluía los límites del árbol y del bosque, y cuyo lado mayor seguía el gradiente altitudinal. En ambos sitios, los individuos vivos eran más grandes y tenían un mayor número de cohortes de acículas pendiente abajo. La distribución de las clases de individuos según su forma de crecimiento y tamaño en el sitio O seguía una secuencia de mayor tamaño pendiente abajo, desde abundantes individuos policórmicos arbustivos (krummholz) con pocas cohortes de acículas (1-3) hasta individuos arbóreos mayores unicórmicos con varias cohortes de acículas (4-12). Por el contrario, los cambios estructurales en el ecotono del sitio T fueron graduales y no siguieron de forma tan clara dicha secuencia

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BACKGROUND: Over 50% of patients with head and neck squamous cell carcinoma (HNSCC) present with locoregionally advanced disease. Those at intermediate-to-high risk of recurrence after definitive therapy exhibit advanced disease based on tumour size or lymph node involvement, non-oropharynx primary sites, human papillomavirus (HPV)-negative oropharyngeal cancer, or HPV-positive oropharynx cancer with smoking history (>10-pack-years). Non-surgical approaches include concurrent chemoradiotherapy, induction chemotherapy followed by definitive radiotherapy or chemoradiotherapy, or radiotherapy alone. Following locoregional therapies (including surgical salvage of residual cervical nodes), no standard intervention exists. Overexpression of epidermal growth factor receptor (EGFR), an ErbB family member, is associated with poor prognosis in HNSCC. EGFR-targeted cetuximab is the only targeted therapy that impacts overall survival and is approved for HNSCC in the USA or Europe. However, resistance often occurs, and new approaches, such as targeting multiple ErbB family members, may be required. Afatinib, an irreversible ErbB family blocker, demonstrated antiproliferative activity in preclinical models and comparable clinical efficacy with cetuximab in a randomized phase II trial in recurrent or metastatic HNSCC. LUX-Head & Neck 2, a phase III study, will assess adjuvant afatinib versus placebo following chemoradiotherapy in primary unresected locoregionally advanced intermediate-to-high-risk HNSCC. METHODS/DESIGN: Patients with primary unresected locoregionally advanced HNSCC, in good clinical condition with unfavourable risk of recurrence, and no evidence of disease after chemoradiotherapy will be randomized 2:1 to oral once-daily afatinib (40 mg starting dose) or placebo. As HPV status will not be determined for eligibility, unfavourable risk is defined as non-oropharynx primary site or oropharynx cancer in patients with a smoking history (>10 pack-years). Treatment will continue for 18 months or until recurrence or unacceptable adverse events occur. The primary endpoint measure is duration of disease-free survival; secondary endpoint measures are disease-free survival rate at 2 years, overall survival, health-related quality of life and safety. DISCUSSION: Given the unmet need in the adjuvant treatment of intermediate-to-high-risk HNSCC patients, it is expected that LUX-Head & Neck 2 will provide new insights into treatment in this setting and might demonstrate the ability of afatinib to significantly improve disease-free survival, compared with placebo. TRIAL REGISTRATION: ClinicalTrials.gov NCT01345669.

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The RuvB protein is induced in Escherichia coli as part of the SOS response to DNA damage. It is required for genetic recombination and the postreplication repair of DNA. In vitro, the RuvB protein promotes the branch migration of Holliday junctions and has a DNA helicase activity in reactions that require ATP hydrolysis. We have used electron microscopy, image analysis, and three-dimensional reconstruction to show that the RuvB protein, in the presence of ATP, forms a dodecamer on double-stranded DNA in which two stacked hexameric rings encircle the DNA and are oriented in opposite directions with D6 symmetry. Although helicases are ubiquitous and essential for many aspects of DNA repair, replication, and transcription, three-dimensional reconstruction of a helicase has not yet been reported, to our knowledge. The structural arrangement that is seen may be common to other helicases, such as the simian virus 40 large tumor antigen.

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Purpose: To evaluate the toxicity focussing on hepatic, gastrointestinal and cardiac parameters following PRECISION TACE with DC Bead? versus conventional transarterial chemoembolization (cTACE) in the treatment of intermediate-stage hepatocellular carcinoma (HCC). Methods and Materials: This prospective, randomized, multicentre study was conducted under best practice trial management and authorized by local institutional review boards. Informed consent was obtained. 212 patients (185 men/27 women; mean: 67 years) were randomized to be treated with DC Beads? or cTACE. The majority of both groups presented in a more advanced stage. Safety was measured by rate of adverse events (South West Oncology Group criteria) and changes in laboratory parameters. Cardiotoxicity was assessed by means of left ventricular ejection fraction (LVEF) in MRI or echocardiography. The results of the two groups were compared using the chi-square test and Student`s t-test. Results: Mean maximum alanine transaminase increase in the DC Bead group was 50% in the cTACE group (p < 0.001) and 59% for aspartate transaminase (p < 0.001). For bilirubin, mean increase was 5.30±15.13 vs. 13.53±73.89 µmol/L. Concerning gastrointestinal disorders, 120 adverse events (AEs) occurred in 57/93 (61.3%) patients in the DC Bead group vs. 114 in 49/108 (45.4%) in cTACE. Concerning hepatobiliary disorders, serious AEs occurred in 8/93 (8.6%) vs. 11/108 (10.2%) patients. LVEF showed an increase in the DC Bead group by +2.7±10.1 percentage points and a small decrease by -1.5±7.6 in the cTACE group, p=0.018. Conclusion: PRECISION TACE is safe, even in more advanced HCC patients. Serious liver and cardiac toxicity were significantly lower in the DC Bead group.

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Background: A hospitalised patient infected with MRSA was found to harbour a VISA strain after 6 weeks of treatment with vancomycin. Additional contact measures were reinforced according to CDCs recommendations. We decide to evaluate if these applied control measures were effective. Objective: To evaluate the efficacy of strict additional contact measures to contain the dissemination of VISA from an infected patient. Methods: All patients from the unit were screened weekly for MRSA during a 6-week period, whereas health care workers (HCW) were screened only once. Screening specimen included nose, throat, groin, and clinical specimens for patients, and only nose and throat for HCW. Broth enrichment and chromogenic agar (MRSA-select) were used for MRSA detection. All MRSA isolates were tested on Van screen plates, and growing colonies were tested for MIC of vancomycin. MIC was performed using Etest. Population analysis was done for VISA confirmation. One strain per person was typed by Double Locus Sequence Typing (based on clfB and spa sequencing). Results: 66 patients hospitalized in the same service during the 6 weeks and 55 HCW were screened for MRSA and VISA. MRSA was found in 16/66 (24%) patients and 1/55 (2%) HCW. 16/17 MRSA from patients belonged to the same genotype that the VISA strain. The remaining patient had a MRSA identical to the HCW isolate. Among the 16 MRSA isolates sharing the same genotype than the VISA strain, two showed Etests vancomycin MIC of only 4 mg/L. MIC results were confirmed by the population analysis. They were not considered as VISA, but as MRSA with increased vancomycin MICs. Both isolates were obtained from two roommates. Conclusion: Strict additional contact measures were found to be effective to contain VISA dissemination. However, the identification of two isolates with increased vancomycin MIC (4 mg/L) in two roommates raised the question of the need to routinely test this susceptibility and of adequate control measures for patients harbouring such isolates.

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INTRODUCTION: This trial randomly assessed short-term adjuvant hormonal therapy added to radiotherapy (RT) for intermediate- and high-risk (UICC 1997 cT2a or cT1b-c with high PSA or Gleason score) localised prostate cancer. We report acute toxicity (CTCAE v2) assessed weekly during RT in relation to radiation parameters. PATIENTS AND METHODS: Centres selected the RT dose (70, 74 or 78Gy) and RT technique. Statistical significance is at 0.05. RESULTS: Of 791 patients, 652 received 3D-CRT (70Gy: 195, 74Gy: 376, 78Gy: 81) and 139 received IMRT (74Gy: 28, 78Gy: 111). During RT, grade 3 gastrointestinal (GI) and genitourinary (GU) toxicities were reported by 7 (0.8%) and 50 (6.3%) patients, respectively. No grade 4 was reported. The risk of grade 2 GI toxicity increased significantly with increasing D50%-rectum (p=0.004) and that of grade 2 GU toxicity correlated only to Dmax-bladder (p=0.051). 3D-RT technique, increasing total dose and V95% >400 cc increased D50% and Dmax. One month after RT, only 14 patients (1.8%) reported grade 3 toxicity. AST did not seem to influence the risk of GU or GI acute toxicity. CONCLUSION: RT up to 78Gy was well tolerated. Dmax-bladder and D50%-rectum influenced the risk of grade 2 GU toxicity and GI toxicity, respectively. Both were lower with IMRT but remained high for an irradiated RT volume>400 cc for 3D-RT and for a dose of 78Gy. Hormonal treatment did not influence acute toxicity.

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We face the problem of characterizing the periodic cases in parametric families of (real or complex) rational diffeomorphisms having a fixed point. Our approach relies on the Normal Form Theory, to obtain necessary conditions for the existence of a formal linearization of the map, and on the introduction of a suitable rational parametrization of the parameters of the family. Using these tools we can find a finite set of values p for which the map can be p-periodic, reducing the problem of finding the parameters for which the periodic cases appear to simple computations. We apply our results to several two and three dimensional classes of polynomial or rational maps. In particular we find the global periodic cases for several Lyness type recurrences