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سابقه و هدف: امروزه با افزایش جمعیت، افزایش تقاضای مصرف کاغذ و مقوا و همچنین محدودیت بیشتر مواد اولیه مصرفی، تولید کاغذ از خمیرکاغذ های پربازده و مکانیکی جایگاه ویژه و خاص خود را پیدا کرده است. این خمیرکاغذها راندمان بیش از 85 درصد دارند و مقدار ماده چوبی حل شده در آن ها کمتر از خمیرهای شیمیایی و نیمه شیمیایی است، اما بعلت وجود لیگنین، مواد عصاره‌ای و یون‌های فلزی موجود در این خمیرکاغذ ها، مصرف آن ها را به زمان های کوتاه مدت محدود کرده است و در طولانی مدت دچار برگشت روشنی و زردشدگی نوری می‌شوند. این تحقیق با هدف تاثیر افشاندن DTPA، نانوسلولز و نانوکیتوزان بر ویژگی‌های نوری خمیرکاغذ شیمیایی- مکانیکی (CMP) انجام گرفت. مواد و روش ها: به همین منظور، ابتدا مقداری ازخمیرشیمیایی-مکانیکی(CMP) رنگبری شده کارخانه چوب و کاغذ مازندران به عنوان نمونه شاهد انتخاب شد. از خمیرکاغذ‌های مذکور کاغذهایی با وزن پایه gr/m2 60 تهیه شد. در این تحقیق، نانوسلولز از نوع نانوسلولز فیبریله شده، با پتانسیل زتا منفی، که با روش مکانیکی تهیه شده، از شرکت دانش بنیان نانونوین پلیمر( پارک علم و فن آوری مازندران)(ساری-ایران)، با متوسط قطر الیاف 35 نانومتر و درصد خلوص حدود 99 درصد خریداری و در 2سطح 0 و 2 درصد بر روی کاغذ های حاصل از خمیرکاغذ CMP افشانده شد. نانوکیتوزان نیز که به صورت پودری کرم رنگ و شفاف می‌باشد، از شرکت Seafresh کشور تایلند با وزن ملکولی 270 کیلودالتون، درجه استیلاسیون 93 درصد تهیه شد. محلول نانوکیتوزان در 2سطح 0 و 2 درصد بر روی کاغذ های حاصل از خمیرکاغذ CMP افشانده شد. دی اتیلن تری آمین پنتا استیک اسید (DTPA) با مقدار مواد جامد 50 درصد و ویسکوزیته cps 25 از شرکت DIPER-Samchun (کره جنوبی) تهیه گردید. ابتدا مقداری DTPA بصورت محلول 0/5 درصد آماده سازی و سپس بر روی کاغذ های دست ساز افشانده شد. بعد از ساخت کاغذهای دست‌ساز 60 گرمی، عملیات افشاندن بر روی سطح تعدادی از نمونه‌های آزمونی با استفاده از 2 درصد نانو کیتوزان، 2 درصد نانوسلولز و 0/5 درصد DTPA ، به‌صورت جداگانه و همزمان و در زمان20 ثانیه و در فاصله 20 سانتی‌متر انجام شد. سپس با رعایت شرایط استاندارد، ویژگی‌های نوری نمونه ها شامل روشنی، ماتی، زردی و سبزرنگی کاغذ ها با استفاده از آزمون‌های استاندارد TAPPI و ASTMاندازه‌گیری شد.یافته های تحقیق: نتایج این پژوهش نشان داد که با افشاندن DTPA، نانوسلولز و نانوکیتوزان روشنی، زردی، سبزرنگی، فاکتور L* و ماتی افزایش و فاکتورa* در کاغذ حاصل روند کاهشی را نشان داده است. با افشاندن نانوسلولز بر روی نمونه‌های آزمونی اکثر ویژگی‌های نوری بجز زردی کاغذ حاصل بهبود معنی‌داری از خود نشان داده است. در این حالت مناسب‌ترین ویژگی‌ها در کاغذ حاصل از افشاندن DTPA و همچنین در تیمار افشاندن هم‌زمان DTPA، نانوسلولز و نانوکیتوزان بر روی کاغذ های دست ساز مشاهده گردید، که باعث افزایش و بهبود تمامی ویژگی های نوری بصورت معنی‌داری شده است، که می‌توان آن را به عنوان تیمار برتر انتخاب و معرفی کرد. نتایج ارزیابی برگشت درجه روشنی کاغذ حاصل از خمیر کاغذ CMP نشان داد که اغلب تیمارها منجر به کاهش نسبی برگشت درجه روشنی کاغذ شده است. در بین تیمارهای مختلف، کمترین مقادیر برگشت درجه روشنی در کاغذ حاصل از افشاندن DTPA 5/0 درصد و بیشترین آن با افشاندن نانوکیتوزان بر روی کاغذ حاصل به‌دست آمده‌ است. نتایج ارزیابی تصاویر SEM نمونه های آزمونی نیز نشان داد که در مقایسه با نمونه شاهد، با افشاندن نانو کیتوزان و نانوسلولز و همچنین در تیمار افشاندن هم‌زمان DTPA، نانوسلولز و نانوکیتوزان کاغذ حاصل دارای ویژگی‌های سطحی و ساختاری مطلوب‌تری بوده و وجود فضاهای خالی (حفره‌) کمتر و سطح اتصال بیشتری الیاف در نمونه‌های آزمونی آن، می تواند ویژگی‌های نوری مطلوب‌تری را از خود دهد.نتیجه گیری: نتایج نشان داد که با افشاندن نانوسلولز، نانو کیتوزان و DTPA بر روی نمونه‌های آزمونی، خواص نوری، روشنی، سبزی، ماتی، فاکتور a* ، فاکتور l* ، زردی و برگشت روشنی بهبود یافته است. علاوه بر این، در بین تیمارهای مختلف، تیمار افشاندن با DTPA در کهنه شدگی حرارتی طولانی مدت و استفاده از نانو کیتوزان و نانو سلولز در کهنه شدگی حرارتی کوتاه‌مدت، اثرات قابل‌توجهی بر پایداری روشنی و کاهش بازگشت رنگ کاغذ داشته، در نتیجه، دوام کاغذ در برابر تخریب حرارتی افزایش یافته است.

Objective: To determine whether dynamic renal scans – DTPA or MAG3 – routinely performed after flexible ureteroscopies (f-URS) could detect the development of an obstruction and thus promote prompt early intervention for kidney preservation. Patients and methods: In this retrospective study, with all the data recorded prospectively between April 2010 and October 2023, 250 renal units in 242 patients with upper urinary tract stones (UUTS) who underwent ureterorenoscopy by one surgeon in the same medical center were evaluated. Stone-free rate (SFR) was defined as no residual fragments at all using an intraoperative “triple test”. The following characteristics were examined: gender, BMI, age, Hounsfield unit, stone diameter, laterality, renal/ureteral stones, stone-free rate, and auxiliary procedures per renal unit. The Clavien-Dindo classification was used to report complications. Renal units with residual stones were scheduled for a 2nd f-URS. Post- flexible ureteroscopy ureteral obstruction and renal function were detected using renal scan DTPA or MAG-3. The primary outcome was renal/ ureteral obstruction. Results: The mean patient age was 53 years. The mean stone size was 12.3 mm. Stones in renal pelvis, upper, middle and lower calyces were treated in 9.2% (23), 27.6% (69), and 30.8% (77) of cases, respectively; 44% (110) ureteral stones were also treated. The single- and second-session SFRs were 94.8% and 99.7%, respectively. A third auxiliary procedure was needed in one renal unit (0.4%). The mean number of procedures per renal unit was 1.06 (264/250). Ureteral double-J stents were inserted in 53.6% (134) of the cases. In 37 (14.8%) cases, a stent was placed before surgery. Post-operative complications were minor, with readmission and pain control needed in only two patients (0.8%). No avulsion or perforation of the ureters was observed. In six patients with t1/2 between 10-20 minutes, a second renal scan revealed spontaneous improvement and no obstruction in five patients. One patient with large stones and a history of prior ureteroscopy developed a ureteral stricture (0.4%) and needed treatment with laser endoureterotomy. Conclusions: Post-flexible ureteroscopy obstruction due to ureteral stricture is very rare. A routine renal scan post-operatively may be used in potentially high-risk patients.

Agricultural soils play a key role in the achievement of a circular nutrient economy. The use of sewage sludges as fertilizers is important for such an achievement, assisting in the maintenance of soil health and nutritional crop value. This study was established, after 23 years of a fertilization experiment, in calcareous soil under a maize monoculture. The treatments included mineral fertilization as a control (MIN, 225 kg N ha−1) and two sludge treatments, where doses followed a threshold sludge nitrogen criterion (SNC, 170 kg org-N ha−1) or a threshold soil phosphorus criterion (SPC; when the soil Olsen-P value exceeded 40–60 kg P ha−1, the sludge application was stopped). A detailed study was performed on Cd, Cu, F, Mn, Pb, and Zn soil extractable with diethylenetriaminepentaacetic acid (DTPA), as well as the nutrient and heavy metal concentration of different fractions of the maize plant (grain, cob, and the rest of the plant). Extractions were also quantified. No biomass-yield differences were observed in the different parts of the maize plant in the year of sampling. Sludges increased the soil DTPA extraction of Cd, Cu, Fe, and Zn and diminished Mn extraction, without differences in extractable Pb. The SNC, when compared with MIN, showed increased P cob concentrations, and in grain, it showed increased Fe, Cr, and Co concentrations. The SPC figures of the studied parameters were, in general, between both treatments (MIN and SNC), although Cr extractions in grain diminished vs. SNC. Based on the results, the SPC can be recommended as it also avoids excessive available-P build up.

Zinc is an essential nutrient for humans, animals, and plants. Zinc uptake by crops is dictated by zinc availability in the soil, which in turn may be dictated, at least in part, by soil mineralogy. Little is known about the phytoavailability of Zn in Andisols, which are important agricultural soils in volcanic regions, such as Japan, New Zealand, and southern Chile. In this study, we assessed the vegetative growth response of perennial ryegrass (Lolium perenne, L.) to Zn fertilization in an Andisol from southern Chile. Ryegrass was grown in a greenhouse pot experiment with twelve rates of Zn application from 0 to 6075 mg Zn/kg soil. After 63 days, shoot length, specific leaf area, and biomass were measured. Foliar Zn concentrations were measured and correlated with plant-available Zn as measured by a diethylenetriaminepentaacetic acid (DTPA)-soil extraction (DTPA-Zn hereafter). Zinc toxicity to ryegrass was assessed using the Toxicity Relationship Analysis Program. This study demonstrated that a DTPA-Zn level of 1 mg Zn/kg soil was not limiting for ryegrass growth. Although Zn fertilization did not improve ryegrass growth in the studied Andisol, this study still has practical implications. Zinc deficiency in humans is a global problem and increasing Zn in staple food and forage crops may require Zn fertilization. This study suggests that Andisols can be fertilized with high doses of Zn without a risk of causing Zn toxicity to crops. However, a DTPA-Zn level of >489 mg Zn/kg soil decreased shoot length, indicating a toxicity response.

Se realizó un estudio para evaluar la variación de pH, disponibilidad y asociaciones químicas de Cd en dos Latosoles previamente contaminados modificados con enmiendas minerales y orgánicas. Los Latosoles fueron contaminados con Cd y modificados con lombricomposta, torta de filtración de caña de azúcar, torta de palmiste, cal, roca fosfórica o zeolita. La disponibilidad de cadmio se evaluó mensualmente en las mezclas de enmiendas de suelo/suelo contaminadas con los extractantes DTPA y Mehlich-3 durante doce meses de incubación. Al final de este período, se realizó un procedimiento de extracción secuencial en las mezclas para identificar las formas de Cd presentes en las diversas fracciones geoquímicas. La cal inmovilizó al Cd en mayor extensión (60%), siendo el metal transferido a fracciones menos disponibles. El extractante Mehlich-3 tuvo una alta correlación (0. 96**) con la fracción disponible examinada por el procedimiento de extracción secuencial. En general, las enmiendas orgánicas produjeron pequeños efectos en el pH final de las mezclas de enmiendas de suelo/suelo en comparación con el pH inicial del suelo. Las enmiendas minerales provocaron una mejora del pH del suelo y el efecto más pronunciado ocurrió con el uso de cal.

Conventional farming always modifying by good innovation in agriculture, while the holistic idea of organic farming checks the use of synthetic inputs where in opposite side, the concept of natural farming allowing farming with few traditional and locally available inputs. The all three farming concepts are fundamentally different, to check it on real field, a experiment was conducted on medium black calcareous clayey soil at Junagadh (Gujarat) during rabi 2019-20 to kharif 2020 in order to evaluate low cost natural farming, organic farming and conventional farming in major six crops of Gujarat. The experimental results revealed that conventional farming module significantly increased yields of crops as compared to organic farming and low cost natural farming. Significantly higher available nitrogen, phosphorous and potassium after harvest was found under conventional farming, while organic farming module registered significantly higher organic carbon, heat soluble S; DTPA-extractable Fe, Zn, Cu and Mn after harvest, which was found at par with conventional farming. Economic analysis showed that maximum net returns gross returns, and B:C ratio were observed under conventional farming module.

The synthesis of core–shell magnetic mesoporous nanoparticles (MMSNs) through a phase transfer process is usually performed at the 100–250 mg scale. At the gram scale, nanoparticles without cores or with multicore systems are observed. Iron oxide core nanoparticles (IO) were synthesized through a thermal decomposition procedure of α-FeO(OH) in oleic acid. A phase transfer from chloroform to water was then performed in order to wrap the IO nanoparticles with a mesoporous silica shell through the sol–gel procedure. MMSNs were then functionalized with DTPA (diethylenetriaminepentacetic acid) and used for the separation of metal ions. Their toxicity was evaluated. The phase transfer procedure was crucial to obtaining MMSNs on a large scale. Three synthesis parameters were rigorously controlled: temperature, time and glassware. The homogeneous dispersion of MMSNs on the gram scale was successfully obtained. After functionalization with DTPA, the MMSN-DTPAs were shown to have a strong affinity for Ni ions. Furthermore, toxicity was evaluated in cells, zebrafish and seahorse cell metabolic assays, and the nanoparticles were found to be nontoxic. We developed a method of preparing MMSNs at the gram scale. After functionalization with DTPA, the nanoparticles were efficient in metal ion removal and separation; furthermore, no toxicity was noticed up to 125 µg mL−1 in zebrafish.

This work included two different types of dissolving process (inorganic and organic) which used for the complete dissolving barium sulfate (barite). The inorganic solvents were involved digestion on hotplate with recipe of mixture acids with hydrogen peroxide, sulfuric acid, aqua regia, and fusion with sodium carbonate. The second set of experiments was involved organic ligands such as EDTA, DTPA and a mixture of them. Different parameters were tested in these experiments which were time, molarity of the ligand, amount of barium sulfate and pH. Barite was incompletely dissolved when inorganic solvents were used in experiment. Whilst, the organic ligands show that EDTA is the best ligand for the complete dissolving of barite comparing with DTPA and mixture of EDTA and DTPA. The optimal condition of the highest dissolution of barite by using EDTA were time for 30 h, molarity of the ligand is 2 M, amount of barium sulfate = 0.5 g, and pH = 13 at room temperature. At this condition, the dissolution of barite was 88.56%. It is worth noting that the experiments were carried out at room temperature because the study simulates the dissolution of barite scale in petroleum pipes.

Abstract Used as high‐performance electrodes, both structural and compositional alterations of carbon materials play very important roles in energy conversion/storage devices. Especially in supercapacitors, hierarchical pores and heteroatom doping in carbon materials are indispensable. Here the rambutan‐like hierarchically porous carbon microspheres (PCMs) have been constructed via a hydrothermal treatment, followed by carbonization/activation. The hierarchically porous microstructure is composed of three‐dimensional porous carbon networks, which give rise to a large surface area. Moreover, N and O functional groups are introduced in the as‐prepared samples, which could generate the extra pseudocapacitance. Benefitting from the interconnected hierarchical and open structure, PCM exhibits outstanding capacitive performance, for example, superior specific capacitance and rate capability (397 and 288 F g−1 at 0.5 and 20 A g−1, respectively), as well as long cycling stability (about 95% capacitance retention after 10,000 cycles). These encouraging results may pave an efficient way to fabricate advanced supercapacitors in the future.

Release of neutrophil extracellular traps (NETs) is one of the neutrophils’ mechanisms involved in the response to infection. NETs are released from the cell in response to a biological or synthetic stimulus to entrap, immobilize and kill pathogens. Metal ions and metal binding proteins were identified in the structure of NETs, but their role in NET release remains unclear. The aim of this study was to assess how lack of iron and zinc generated by ion sequestration using chelators affects NET release. Neutrophils were isolated from whole blood or buffy coats of healthy blood donors by density gradient centrifugation and incubated with zinc chelators: 20 µM N,N,N,N-Tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), 40 µM diethylenetriaminepentaacetic acid (DTPA) or iron chelators: 400 µM deferoxamine mesylate salt (DFO) and 50 µM iminodiacetic acid (IDA). Next, 100 nM phorbol 12-myristate 13-acetate (PMA) was added to stimulate release of NETs. The amount of released DNA was measured by fluorometry and NETs were visualized by immunofluorescence microscopy. This study demonstrates that iron and zinc chelators are able to modulate NET release. Here we show that preincubation of neutrophils with TPEN and IDA inhibits NET release in cells stimulated with PMA. On the other hand, DFO stimulates NET release. Incubation of cells with DTPA does not affect release of NETs.

Chalcone derivatives have been successfully utilized for a range of biological applications and can cross the blood–brain barrier easily. β-amyloid-specific bis-chalcone derivative, 6,9-bis(carboxymethyl)-14-(4-[(E)-3-(4-(dimethylamino)phenyl)acryloyl]phenoxy)-3-(2-[(2-(4-[(E)-3-(4-(dimethylamino)phenyl)acryloyl]phenoxy)ethyl)amino]-2-oxoethyl)-11-oxo-3,6,9,12-tetraazatetradecanoic acid, DT(Ch)2, was analyzed using molecular modeling to explain the binding modes of the ligand with amyloid fibril and monomer followed by 99mTc-complexation in 95% yield and 98.7% efficiency. High-binding specificity of the radiocomplex was established following in vitro evaluation against 100-fold excess of DT(Ch)2. 99mTc–DT(Ch)2 exhibited 40% in the cingulate cortex followed by >25% in the hippocampus, a distribution pattern aligned to Alzheimer’s affected brain regions. Radiocomplex also displayed rapid plasma clearance followed by hepatobolic and renal modes of excretion.

Abstract Backgrounds Due to the unexpected side effects of the iodinated contrast agents, novel contrast agents for X-ray computed tomography (CT) imaging are urgently needed. Nanoparticles made by heavy metal elements are often employed, such as gold and bismuth. These nanoparticles have the advantages of long in vivo circulation time and tumor targeted ability. However, due to the long residence time in vivo, these nanoparticles may bring unexpected toxicity and, the preparation methods of these nanoparticles are complicated and time—consuming. Methods In this investigation, a small molecular bismuth chelate using diethylenetriaminepentaacetic acid (DPTA) as the chelating agent was proposed to be an ideal CT contrast agent. Results The preparation method is easy and cost—effective. Moreover, the bismuth agent show better CT imaging for kidney than iohexol in the aspect of improved CT values. Up to 500 µM, the bismuth agent show negligible toxicity to L02 cells and negligible hemolysis. And, the bismuth agent did not induce detectable morphology changes to the main organs of the mice after intravenously repeated administration at a high dose of 250 mg/kg. The pharmacokinetics of the bismuth agent follows the first—order elimination kinetics and, it has a short half—life time of 0.602 h. The rapid clearance from the body promised its excellent biocompatibility. Conclusions This bismuth agent may serve as a potential candidate for developing novel contrast agent for CT imaging in clinical applications.

Abstract This study aimed to prepare a chelating agent SA-20 using diethylenetriaminepentaacetic acid (DTPA) and low molecular weight sodium polyacrylate raw material for the removal of barium sulfate (BaSO4) scale. The morphology of the resulting chelating agent was characterized by scanning electron microscopy. The BaSO4 scale removal ability of SA-20 was comprehensively evaluated by the dissolving ability, particle size analysis, corrosion performance, and fracture conductivity before and after the scale removal. The results showed that the SA-20 has a good BaSO4 scale removal ability due to the chelation, lattice distortion, and dispersion of DTPA and low molecular weight sodium polyacrylate.

Introduction: The gold standard method for estimating glomerular filtration rate (GFR) in potential donors is diethylenetriaminepentaacetic acid (DTPA) renogram. But DTPA renogram being inconvenient, expensive, and with limited access , hence we need other methods which are noninvasive and provide a comparatively accurate estimation of GFR. Various estimating equations such as Cockcroft–Gault (CG) equation, Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) are available but have not been well studied or compared to DTPA GFR measurement. Methods: A total of 100 healthy donors (females and males) were studied. All participants underwent 99mTc DTPA renogram, and the GFR obtained was compared with MDRD, CG, and CKD-EPI-estimated GFR. Correlation between variables was estimated by statistical analyses in SPSS software version 18.0, and accuracy of various methods was studied. The data were analyzed by paired t-test, and Pearson's correlation test was used to correlate between two variables. Results: Out of the 100 donors, 79% were females and out of 100 renal recipients, 88% were males. The mean age for donors was 47.27 ± 10.93 years and for recipients was 35.02 ± 11.11 years. The mean GFR (mL/min per 1.73 m2) obtained by DTPA, CG, MDRD, and CKD-EPI was 109.91 ± 20.3, 114.10 ± 21.25, 128.66 ± 22.69, and 108.86 ± 12.72, respectively. The overall mean bias was smallest for CKD-EPI (standard deviation: 18.79). The bias and mean absolute difference between calculated and measured GFR for CKD-EPI, MDRD, and CG were 8.98 and 16.05, −17.97 and 23.26, and −5.76 and 23.29, respectively. There was a positive correlation between GFR by DTPA and GFR by CKD-EPI (0.408) and MDRD (0.399). Conclusions: Despite a wide variation in absolute values of GFR obtained by these methods, CKD-EPI and MDRD showed a positive correlation with DTPA GFR. CKD-EPI had least bias and thus correlated best with DTPA. In potential donors, these equations may be inadequate to replace DTPA for estimating GFR and due to limitations of our study further studies are needed with bigger sample size and longer duration.

Mehlich-3 (M-3) is used as a universal nutrient extractant due to its ability to simultaneously extract multiple elements. This study aimed to assess M-3 for the simultaneous determination of plant-available zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), boron (B), and sulfate (SO4-S) in a soil amended with switchgrass- (SGB) and poultry litter-derived biochars (PLB), which were used to vary soil pH values (5.7–7.6) and organic carbon (OC) content (2.0–5.5%) in the short-term. Soil and ryegrass (Lolium perenne) were sampled from a growth chamber experiment and analyzed for plant-available and tissue phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), micronutrients (B, Cu, Fe, Mn, and Zn), and sulfur contents. The commonly accepted extractants diethylenetriaminepentaacetic acid (DTPA), for micronutrients, and 0.008 M monocalcium phosphate (MCP), for SO4-S, were used for the evaluation. Relationships between M-3 and DTPA were not reliable for micronutrient availability, although highly significant relationships for Zn and Cu were found. However, M-3-extractable S was highly correlated with S contents in ryegrass tissues regardless of the treatments and provided a 1:1 relationship between MCP and M-3. This offers the potential to eliminate MCP by simply adding S determination after extraction with M-3. Although this research evaluated the d-index for an easier linear relationship between the traditional and proposed methods, more research using several soil samples is needed to establish models and find conversion equations for micronutrients and SO4-S between DTPA-sorbitol, MCP, and M-3.

This paper describes the method for obtaining a new derivative of the closo-decaborate anion with diethylenetriaminepentaacetic acid (DTPA) as a pendant group attached to the boron cluster through an alkoxyl spacer chain. This derivative is formed by the interaction of 1,4-dioxane derivative of the anion [B10H10]2- with DTPA potassium salt in an aqueous medium. As a result of the reaction, an exo-polyhedral cyclic substituent is opened, and then the addition of a polyfunctional group through an oxygen atom occurs. The synthesized compound is in fact an effective polydentate ligand capable of coordinating to the complexing agent both due to the donor atoms of the attached DTPA fragment and through the formation of three-center two-electron bonds. The obtained compound interacts with gadolinium(III) carbonate forming a complex of the composition [Gd2B10H9O2C4H8(dtpa)]·3H2O. The synthesized substances were studied by IR spectroscopy, polynuclear (11B, 13C and 1H) NMR spectroscopy, ESI mass spectrometry, elemental and thermographic analysis. closo-Decaborate with the pendant DTPA group is of interest in 10B neutron capture therapy of malignant tumors due to the high content of boron atoms and a convenient way of their transport to the affected cells. The obtained boron-containing derivatives of gadolinium(III) can act as drugs of combined action, because they can perform, in addition to the above described therapeutic function, the diagnostic function due to the presence of gadolinium atoms int hem.

Purpose: In cases of occupational accidents in nuclear facilities or subsequent to terrorist activities, the most likely routes of internal contamination with alpha-particle emitting actinides, such as plutonium (Pu) and americium (Am), are by inhalation or following wounding. Following contamination, actinide transfer to the circulation and subsequent deposition in skeleton and liver depends primarily on the physicochemical nature of the compound. The treatment remit following internal contamination is to decrease actinide retention and in consequence potential health risks, both at the contamination site and in systemic retention organs as well as to promote elimination. The only approved drug for decorporation of Pu and Am is the metal chelator diethylenetriaminepentaacetic acid (DTPA). However, a limited efficacy of DTPA has been reported following contamination with insoluble actinides, irrespective of the contamination route. The objectives of this work are to evaluate the efficacy of prompt local and/or systemic DTPA treatment regimens following lung or wound contamination by actinides with differing solubility. The conclusions are drawn from retrospective analysis of experimental studies carried out over 10 years.Materials and Methods: Rat lungs or wounds were contaminated either with poorly soluble Mixed OXide (U, Pu O2) or more soluble forms of Pu (nitrate or citrate). DTPA treatment was administered promptly after contamination, locally to lungs by insufflation of a powder or inhalation of aerosolized solution or by injection directly into the wound site. Intravenous injections of DTPA were given either once or repeated in combination with the local treatment. Doses ranged from 1 to 30 µmol/kg. Animals were euthanized from day 7–21 and alpha activity levels were measured in urine, lungs, wound, bone and liver for determination of decorporation efficacy.Results: Different experiments confirmed that whatever the route of contamination, most of the activity is retained at the entry site after insoluble MOX contamination as compared with contamination with more soluble forms which results in very low activities reaching the systemic compartment and subsequent retention in bone and liver. Several DTPA treatment regimens were evaluated that had no significant effect on either lung or wound levels compared with untreated animals. In contrast, in all cases systemic retention (skeleton and liver) was reduced and urinary excretion were enhanced irrespective of the contamination route or DTPA treatment regimen.Conclusion: The present study demonstrates that despite limitation of retention in systemic organs, different DTPA protocols were ineffective in removing insoluble actinides deposited in lungs or wound site. For moderately soluble actinides, local or intravenous DTPA treatment reduced activity levels both at contamination and at systemic sites.

Calcium carbonate (CaCO3) scale inhibition by Diethylenetriaminepentaacetic acid (DTPA) on copper and aluminium metal surfaces was studied at 60 and 100 °C. The samples were characterized using X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results revealed a novel pot like morphology for calcite which was resulted from the transformation of dumbbell morphology. The pot like morphology exposed the possibility of hollow structures for other polymorphs and is resulted from the breaking apart of the dumbbell structures at the middle, followed by fluffing of the separated parts.

This study estimated the effects of gypsum on the potassium and iron release rate from phlogopite under laboratory conditions. A randomized design with the factorial arrangement and three replications was utilized to run the current experiment. Treatments included different levels of gypsum (0, 2, 5, 12 and 25%) and eight different time periods (12 hours, 1, 2, 4, 8, 16, 32 and 64 days). The result of this study indicated that the rate of potassium and iron release were faster initially, and it slowed down thereafter. As gypsum content increased, potassium and iron concentrations decreased which is haply due to immense presence of calcium ions. Calcium ions change the equilibrium of K by increasing the amount of gypsum. The results revealed that the potassium and iron release rate from phlogopite is drastically declined in the presence of gypsum.

چکیده سابقه و هدف: تامین عناصر غذایی کم مصرف در بهبود فرایندهای بیولوژیکی گیاهان ضروری است. مقادیر کل عناصر در خاک شاخص مناسبی از قابلیت استفاده برای گیاهان نمی باشد و اغلب بصورت شکل‌های غیرقابل جذب حضور دارند. مواد هومیکی می تواند شکل‌های شیمیایی عناصر در خاک را تغییر دهد. لذا این تحقیق با هدف بررسی تاثیر لئوناردیت در تغییر شکل‌های شیمیایی منگنز در خاک‌های زراعی انجام شد. مواد و روشها تعداد 20 نمونه خاک زراعی از عمق 30-0 سانتیمتری از مزارع شهرستان ارومیه برداشت شد. برخی از ویژگی‌های فیزیکوشیمیایی به روش‌های استاندارد، منگنز قابل استفاده به روش DTPA و کانی شناسی رس (20) اندازه گیری شدند (21). طیف FT-IR لئوناردیت جهت تعیین گروههای عاملی بررسی شد. بررسی های آزمایشگاهی بصورت فاکتوریل در قالب طرح پایه کاملا تصادفی در سه تکرار انجام شد. چهار نمونه خاک متفاوت انتخاب شده و با استفاده از MnSO4.H2O با غلظت 200 میلی گرم در کیلوگرم منگنز تیمار شد و به مدت دو ماه در رطوبت ظرفیت مزرعه‌ای نگهداری شدند. بعد از انکوباسیون سطوح مختلفی از لئوناردیت (0، 2 و 4 درصد) اضافه شد. منگنز قابل استفاده و شکلهای شیمیایی آن پس از گذشت 20، 90 و 120 روز با استفاده از روش DTPA و عصاره گیری متوالی (32) اندازه گیری شد. یافته ها نتایج نشان داد که کمیت و کیفیت کانی‌های رس متفاوت بود و کانی غالب خاک‌های مورد مطالعه ایلیت بود. نتایج نشان داد که لئوناردیت دارای گروه‌های عاملی مختلف بوده و تاثیر معنی دار در افزایش میزان منگنز قابل استفاده گیاه داشت (P

In the title GaIII complex compound with pentetic acid, [Ga(C14H20N3O10)(H2O)]·3H2O, the GaIII centre is bound in a slightly distorted octahedral coordination sphere by two amine N atoms, three carboxylate O atoms and one water O atom. The complex molecule exists as a zwitterion. In the crystal, the complexes are linked to each other via O—H...O and C—H...O hydrogen bonds, forming layers parallel to (001). Three uncoordinating water molecules link the complex layers via O—H...O, N—H...O and C—H...O hydrogen bonds, forming a three-dimensional network.

Cadmium (Cd) is of special importance among heavy metals because its toxicity to the plant is 20 times higher than other heavy metals. The present study was conducted to evaluate the trend of available soil Cd changes over time and its relationship with soil properties. Treatments consisted of 13 soil samples and two Cd rates (12.5 and 25 mg kg-1) as a factorial in a complete randomized design with two replications. DTPA extractable Cd was measured upon 5, 10, 20, 30, 60 and 90 days after adding Cd rates to the soils. The results showed that DTPA extractable Cd was increased as Cd application rates was raised in all soils. DTPA extractable Cd was decreased over time; however, at the end of the experiment, much of the added cadmium to the soil remained in use. Among the soil properties, calcium carbonate showed a significant negative correlation with DTPA extractable Cd in most of the incubation times in both Cd rates. DTPA extractable Cd also showed a significant negative correlation with pH and soil sand and a significant positive correlation with OC. Also, the results of the fitting of cadmium adsorption data with the kinetic equations showed that the exponential function equation was the most suitable kinetics descriptive equation for variations in cadmium adsorption in the studied soils.

The aim of this research was to determine the most suitable extraction method for the available iron contents of calcareous soils in Trakya Region, Turkey. For this purpose ten calcareous soil samples were taken from research area and five extraction methods (Lindsay and Norvell, Wear and Evans, Olson, Soltanpur and Mehlich methods) were used and three biological indices (dry matter yield, Fe concentration, Fe uptake) were compared. The plant biological indices were determined with wheat (Triticum aestivum L.) plant grown under greenhouse conditions. At the end of the experiment, the highest correlation coefficients (r) were determined between the 0.005 M DTPA + 0.01 M CaCl2 + 0.1 M TEA, 0.005 M DTPA + 1 M NH4HCO3 methods and the biological indices. The correlation coefficients (r) for the 0.005 M DTPA + 0.01 M CaCl2 + 0.1 M TEA method and the three biological indices were 0.648**, 0.780** and 0.656** respectively. For the 0.005 M DTPA + 1 M NH4HCO3 method, these coefficients were determined 0.595**, 0.637** and 0.625**, respectively. Consequently, these extraction methods were suggested for the determination of the available Fe contents of the calcareous soils in Trakya Region, Turkey.

In this research available iron was measured in 21 calcareous surface soil samples (0-30 cm) by five methods including DTPA, AB-DTPA, AC-EDTA, hydroxylamine, reference ammonium oxalate and rapid ammonium oxalate. Fe fractions were also determined by the modified sequential extraction procedures introduced by Singh et al. According to results, rapid ammonium oxalate and AC-EDTA methods extracted the maximum (856.03 mg.kg-1) and minimum (4.46 mg.kg-1) amounts of Fe, respectively. Rapid ammonium oxalate extraction method, in addition to Fe-Afeox, extracted other fractions of iron such as Fe-Ex, Fe-Om, Fe-CFeox and Fe-Res. Hydroxylamine method compared to other methods, ectracted Fe mostly from the amorphous oxides source. Regression analysis indicates that Fe-Ex, Fe-AFeox and Fe-Res fractions have major and Fe-Car and Fe-Mnox have minor role in releasing available Fe (with AB-DTPA and DTPA) in the studied soil. According to the statistical relationships, carbonates associated Fe, does not seem a potential source of available Fe in calcareous soils. Organic carbon content and cation exchange capacity of the soils appear the two most influential soil properties that predict available Fe in the studied soils.

Barium sulfate (barite) is one of the widely used weighting materials in the preparation of drilling fluid for deep oil and gas wells. Barite is not soluble in the regular solvents; such as, hydrochloric acid (HCl) and other acids. Therefore, in this study, we focused on evaluating the dissolution of the industrial barite particles in different chelating agents. Chelating agents; such as, diethylene triamine penta acetic (DTPA), ethylene diamine tetra acetic (EDTA), and hydroxyethyl ethylene diamine tri acetic (HEDTA) acids with high and low pH values were used in this study. The effect of the base of chelating agents, namely alkali and alkali earth hydroxides, on the dissolution of barite was also investigated. For the first time, the optimum pH, concentration, and base (sodium or potassium) of chelating agents which yielded the maximum dissolution were investigated in this study at a high temperature. Previous studies did not consider the wellbore constraints during their experiments and they used chelating agent volume to barite weight ratio, which could not be implemented in the real wells. In this study and for the first time, we considered the wellbore volume (chelating agent volume that can be used) and the barite weight (filter cake) during the dissolution experiments. Based on the results obtained from this study, potassium base DTPA-K5 and EDTA-K4 of a concentration of 20 wt.% were found to be the most effective chelating agents to dissolve barite. The solubility of barite was found to be 26.8 g/L in a solution containing 20 wt.% of DTPA-K5 and 25.6 g/L in a solution containing 20 wt.% of EDTA-K4 during a soaking time of 24 hrs and a pH value above 11 at 200°F.

The interaction of hafnium(IV) salts (oxide-dichloride, chloride, and bromide) with nitrilotriacetic acid (NTA), diethylenetriamminepentaacetic acid (DTPA), 1,2-diaminocyclohexanetetraacetic acid (CDTA), 1,3-dipropylmino-2-hydroxy N,N,N′,N′-tetraacetic acid (dpta), and N-(2-hydroxyethyl)ethylenediamine triacetic acid (HEDTA) has been studied. The corresponding complexes Na2[Hf(NTA)2]·3H2O (1), Na[HfDTPA]·3H2O (2), [HfCDTA(H2O)2] (3), and Na[Hf2(dpta)2]·7.5H2O·0.5C2H5OH (4) have been isolated and characterized and their structures have been determined by single crystal X-ray diffraction. Biological studies of [HfCDTA(H2O)2] have shown that in 5% glucose solution this complex has low toxicity and good contrasting ability.

Salivarian trypanosomes are extracellular parasites causing anthroponotic and zoonotic infections. Anti-parasite vaccination is considered the only sustainable method for global trypanosomosis control. Unfortunately, no single field applicable vaccine solution has been successful so far. The active destruction of the host’s adaptive immune system by trypanosomes is believed to contribute to this problem. Here, we show that Trypanosome brucei brucei infection results in the lasting obliteration of immunological memory, including vaccine-induced memory against non-related pathogens. Using the well-established DTPa vaccine model in combination with a T. b. brucei infection and a diminazene diaceturate anti-parasite treatment scheme, our results demonstrate that while the latter ensured full recovery from the T. b. brucei infection, it failed to restore an efficacious anti-B. pertussis vaccine recall response. The DTPa vaccine failure coincided with a shift in the IgG1/IgG2a anti-B. pertussis antibody ratio in favor of IgG2a, and a striking impact on all of the spleen immune cell populations. Interestingly, an increased plasma IFNγ level in DTPa-vaccinated trypanosome-infected mice coincided with a temporary antibody-independent improvement in early-stage trypanosomosis control. In conclusion, our results are the first to show that trypanosome-inflicted immune damage is not restored by successful anti-parasite treatment.

To counteract the loss of organic matter of agricultural soils, the use of compost from green and woody residues is a promising strategy. In this study, an organic farm (NE Italy) was investigated to determine the effect of management practices on physical and chemical soil properties. The organic system received three years ago a single high dose (60 t ha−1) of a wood-based compost (WBC), and it was compared with a conventional farm that annually managed mineral plus manure fertilization. In both systems, soil samples from a vineyard and field-scale rotation were collected, together with soil samples from an area not cultivated and not treated neither with compost nor with fertilizers or manure (untreated = control). Soil samples were characterized for soil fertility parameters, extractable fractions of macro- and micronutrients with DTPA and Mehlich3, and their total content. WBC was physically, chemically, and biologically characterized. The results showed that WBC fulfilled the requirements prescribed by Italian legislation, and the absence of phytotoxicity and conversely a stimulating activity towards root development was evidenced. From the DNA metabarcoding of the bacterial community, WBC revealed several peculiarities, including the dominance of taxa such as the order Acidimicrobiales, the families Anerolineaceae, Cytophagaceae, Caldimicrobiacese, Saprospiraceae and the archaeon Candidatus Nitrososphaera. Concerning the fertility of soils, the addition of WBC in both the vineyard and field-scale considerably affected some important soil parameters compared to those of conventional fertilization and untreated soil. Among these, WBC strongly increased the organic C content and the amount of the available P. In addition, the concentrations of macro- and micronutrients extractable by DTPA were generally higher with WBC than conventional fertilization. On the contrary, Mehlich3 extractable metals and total metals content were not affected by fertilization. The principal component analysis indicated that organic C, macronutrients (CaDTPA, KDTPA, and POlsen), as well as micronutrients (BDTPA, FeDTPA, and MoDTPA) are principal factors that properly separated conventional fertilization from organic fertilization. Beside this, within the same management, cases by agroecosystem were also well revealed by cluster analysis. In essence, in the short-term, the organic system led to a significant improvement in organic C and plant-available nutrients over the conventional system.

Ion-pairing high-performance liquid chromatography–ultraviolet (HPLC–UV) methods were developed to determine two commonly used chelating agents, ethylenediaminetetraacetic acid (EDTA) in Abilify® (a small molecule drug with aripiprazole as the active pharmaceutical ingredient) oral solution and diethylenetriaminepentaacetic acid (DTPA) in Yervoy® (a monoclonal antibody drug with ipilimumab as the active pharmaceutical ingredient) intravenous formulation. Since the analytes, EDTA and DTPA, do not contain chromophores, transition metal ions (Cu2+, Fe3+) which generate highly stable metallocomplexes with the chelating agents were added into the sample preparation to enhance UV detection. The use of metallocomplexes with ion-pairing chromatography provides the ability to achieve the desired sensitivity and selectivity in the development of the method. Specifically, the sample preparation involving metallocomplex formation allowed sensitive UV detection. Copper was utilized for the determination of EDTA and iron was utilized for the determination of DTPA. In the case of EDTA, a gradient mobile phase separated the components of the formulation from the analyte. In the method for DTPA, the active drug substance, ipilimumab, was eluted in the void. In addition, the optimization of the concentration of the ion-pairing reagent was discussed as a means of enhancing the retention of the aminopolycarboxylic acids (APCAs) including EDTA and DTPA and the specificity of the method. The analytical method development was designed based on the chromatographic properties of the analytes, the nature of the sample matrix and the intended purpose of the method. Validation data were presented for the two methods. Finally, both methods were successfully utilized in determining the fate of the chelates.

Gadolinium diethylenetriaminepentaacetic acid (Gd–DTPA) is widely applied as a contrast enhancer in medical MRI. As Gd–DTPA is only minimally captured in wastewater treatment plants (WTPs) or degraded by UV light and other oxidative processes, concentrations in rivers have increased globally by orders of magnitude following its introduction in 1987. The complex also seems impervious to estuarine scavenging and is beginning to emerge in coastal waters, yet it is unknown how its stability is changed by competition for the DTPA ligand from major seawater cations. We performed potentiometric titrations at seawater ionic strength (0.7 M NaClO4) to determine dissociation constants of the five DTPA carboxylic acid groups, as well as stability constants of Mg, Ca, and Gd complexes with the fully deprotonated and single-protonated ligand. These are in general agreement with literature values at low ionic strength and confirm that complexes with Ca are more stable than with Mg. A new finding, that the DTPA complexes of Mg and Ca appear to be hydrolyzed at elevated pH, implies that their coordination in these chelates is less than hexadentate, enabling additional competition with Gd from dinuclear Mg and Ca species. Side-reaction coefficients for trace-metal-free seawater, calculated from our results, suggest that the higher abundance of Mg and Ca may significantly destabilize Gd–DTPA in coastal waters, causing dissociation and release of as much as 15% of the organically complexed Gd from the ligand. This effect could magnify the particle-reactivity and bioavailability of anthropogenic Gd in sensitive estuarine habitats, indicating an urgent need to further study the fate of this contaminant in marine environments.

In comparison with other micronutrients, the levels of nickel (Ni) available in soils and plant tissues are very low, making quantification very difficult. The objective of this paper is to present optimized determination methods of Ni availability in soils by extractants and total content in plant tissues for routine commercial laboratory analyses. Samples of natural and agricultural soils were processed and analyzed by Mehlich-1 extraction and by DTPA. To quantify Ni in the plant tissues, samples were digested with nitric acid in a closed system in a microwave oven. The measurement was performed by inductively coupled plasma/optical emission spectrometry (ICP-OES). There was a positive and significant correlation between the levels of available Ni in the soils subjected to Mehlich-1 and DTPA extraction, while for plant tissue samples the Ni levels recovered were high and similar to the reference materials. The availability of Ni in some of the natural soil and plant tissue samples were lower than the limits of quantification. Concentrations of this micronutrient were higher in the soil samples in which Ni had been applied. Nickel concentration differed in the plant parts analyzed, with highest levels in the grains of soybean. The grain, in comparison with the shoot and leaf concentrations, were better correlated with the soil available levels for both extractants. The methods described in this article were efficient in quantifying Ni and can be used for routine laboratory analysis of soils and plant tissues.

Canola straw can be used as a raw material for the production of chemimechanical pulp (CMP). In this work, chemimechanical pulp was first produced from canola straw, and then the bleaching performance of the produced chemimechanical pulp was investigated under different conditions (dosages of NaOH and Na2SO3, time, and temperature). The results showed that the yield of chemical pretreatment in the CMP process varied between 57.6% and 64.9%, while the total yield of the process was between 54.1% and 61.9%. Subsequently, the CMP pulp produced via applying 4% NaOH and 8% Na2SO3 at 145 °C for 15 min was bleached with H2O2. The results showed that pulps bleached via applying one stage of 3% H2O2, 3% NaOH, 6% sodium silicate, 0.5% MgSO4, and 0.3% DTPA for 150 min possessed the highest brightness of 60.8% ISO, which is suitable for container board production.

Fertilization of crops with pig manure is a common practice throughout the world. Nevertheless, due to the relatively high copper (Cu) and zinc (Zn) contents in pig manure, continuous application of pig manure could have negative effects on soil and plant. The study aimed at the impacts of long-term applying different pig manure rates (equivalently 0, 100, 250 and 500 kg total N/ha/year from 2002 to 2008 and 0, 10, 25 and 50 t fresh weight/ha/year from 2009 to 2011, respectively) on Cu and Zn accumulation in soil and plant. During the 10 years of the experiment, a total of 2.04 to 10.20 kg/ha/year for Cu, 3.15 to 15.73 kg/ha/year for Zn were applied to the soil. Results from this study showed that long-term pig manure application resulted in serious accumulation of Cu and Zn in soil, total Cu and Zn concentrations increased by 204% and 107% at high application rates, respectively. Although topsoil Cu and Zn concentrations were below concentrations considered phytotoxic to crops, according to current Chinese legislation, it would take only less time than 16 and 27 years of high application rates to reach the allowable limits. Our result also suggested that Cu and Zn leaching occurred in the tested soil. The Cu and Zn concentrations in stalks and grains were not affected by the application of pig manure, and these values were lower than the threshold values for animal and human ingestion.

Eight soil profiles were chosen, representing three locations in Nineveh governorate (Al-Fadhlia, Kara-Tapa, and Al-Hamdania). The study was aimed for better understanding the effect of (caly & silt) fraction and carbonates minerals on distribution of manganese extracted by three selective dissolution methods [DTPA , Glacial acetic acid (GAc.) and DCB] . The results indicated that the DTPA extractable manganese showed a similar behavior in the pedogenic distribution with the highest concentration in surface horizons between 2.5 -5.6 mg. kg-1, but concentrations decreased with depth . However GAc. extractable manganese ranged 25.6-72.2 mg. kg-1 , while DCB extracted between 10-58 mg. kg-1. Statistical analysis showed a significant relation between (clay & silt) fraction of soil and DTPA extractable manganese in two locations (Al-Fadhlia and Al-Hamdania), while GAc and DCB extractable manganese has a significant relationship with (clay & silt) fraction in Kara-Tapa and Al-Hamdania Locations respectively. Carbonateminerals has a significant effect on distribution of extractable manganese only in Al-Hamdania area regardless of the extracting method

Forty soil samples from eight profiles were chosen to represent Al-Fadhilia , Kara-Tapa and Al-Hamdania regions, in Nineveh Province . Three selective dissolution methods were used to extract the different manganese phases DTPA , DCB and GAc. The results indicated that GAc, method was effective in extracting manganese adsorbed on calcium carbonates and clay surfaces ranged 38.78 - 47.74 mg.Kg-1 soil, DCB method was effective in dissolving manganese oxides especially in the thin black deposits and in Mn-Fe concretions was in second order ranged 11.78 - 39.9 mg.Kg-1 soil , while DTPA method was the lowest in extracting available manganese ranged 0.9 - 3.34 mg.Kg-1 soil.

The effect of Cr+6 with and without chelating agents were assessed in mung bean seedlings grown hydroponically. It was noted that the growth parameters showed a declining trend with increasing Cr+6 concentrations without chelate application. Among the seedlings grown with chelated chromium complexes, Cr+6–DTPA (10µM) showed highest growth rate of roots as well as shoots. At higher concentration of Chromium i.e. Cr+6 (100µM), there exhibited high chlorophyll content in mung bean leaves where the seedlings showed stunted growth. The seedlings treated without and with chelated chromium complexes showed increased proline content as compared to control. The enzymatic study showed that, the catalase activity was maximum in shoots as compared to roots and the reverse is true in the case of peroxidase activity i.e. the roots showed higher value than that of the shoots.

No Brasil, com a expansão da silvicultura clonal, o plantio de materiais genéticos mais produtivos e exigentes nutricionalmente tem aumentado o aparecimento de sintomas de deficiência de micronutrientes, principalmente de B, e, mais recentemente, de Cu e de Zn, sobretudo em áreas de Cerrado. Este trabalho teve por objetivo avaliar três métodos de determinação da disponibilidade de Zn (Mehlich-1, Mehlich-3 e DTPA pH 7,3) para mudas de eucalipto cultivadas em casa de vegetação, em amostras de seis solos de Cerrado, bem como a influência de propriedades do solo na eficiência desses extratores. Os tratamentos foram arranjados no esquema fatorial 6 x 5, correspondendo a seis solos e cinco doses de Zn (0, 2,5, 5, 10 e 20 mg dm-3), com quatro repetições, em blocos ao acaso. Os níveis críticos de Zn em solos de Cerrado, para o crescimento de mudas de eucalipto, são iguais ou inferiores a 0,23 e 0,05 mg dm-3, pelos extratores Mehlich-1 e DTPA, respectivamente. Os teores de Zn no solo pelos três extratores, assim como os teores e conteúdo na planta, aumentam com a elevação das doses adicionadas de Zn e são altamente correlacionados entre si. A avaliação da disponibilidade de Zn para mudas de eucalipto pode ser feita com qualquer um dos três extratores; entretanto, o Mehlich-1 é o mais recomendado, pela facilidade operacional deste método em relação aos outros e por ele já ser usado na grande maioria dos laboratórios do país.

Nowdays, iron nanoparticles due to their unique characteristics are used in all of sciences and technology. These nano particles due to their electrical, magnetic, optical and catalytic properties and having high area and activity that is promped by their small size and most importantly many scientists from the entire world are interested in their low cost production. In this project we used method of reduction in the liquid phase for synthesis of iron nano particles. Unlike synthesis so far has been done and they used different kinds of surfactants and capping or they used starch for stabilization, we used chelating agent diethylene triamine penta acetic acid (DTPA) for increasing the stability of iron nano particles for the first time in the world. Ammonium iron(II) sulfate were used for make iron nano particle and Sodium borohydride was used for reduction. This method not only was simple and cheap but also didn’t need special instruments. Also determining of structure, size, particles distribution and surface morphology of this nano particles we used the analysis of FT-IR, XRD and SEM that all of them showed the synthesis of zero valent iron nanoparticles, metallic iron, has been done correctly. The average of synthesis of zero valent iron nano particles is 18 nm and crystal structure of nano particles was designed by using vertical nano lab software. Finally, we studied opration Removal of Radioactive Uranium From groundwater by using iron nanoparticle.

Soil and sediments of the estuaries and wetlands in Northwest of Persian Gulf are recently polluted with different heavy metals because of municipal and industrial wastewaters. Therefore an urgent soil cleaning up and remediation program is vital in this region. Consequently, this study was initiated to screen two plant species (Festuca arundinacea and Cynodon dactylon) for hyperaccumulation of nickel (Ni) and lead (Pb) as one of the candidate methods for cleaning-up soil and sediments of Shadegan wetland. Soil samples (0-30 cm) were collected from two sites in the wetland. The soil samples were treated with solutions of Ni and Pb separately which resulted into content of 50 and 100 mg kg-1 of metals in each soil. Thereafter, the plants were sown in the soils under greenhouse conditions and harvested after 10 weeks. Ni and Pb contents were measured in root and shoot of plants. Results showed that accumulation of Ni and Pb in tall fescue roots were significantly (P

Trace elements are potentially toxic to the environment. Their toxicity in soils relies on their type of chemical associations. Hence it is important to determine the chemical form they occur in the soils in order to assess their quantities. The objective the present work was to evaluate the possibility of using the concentrations of Cu and Zn in different soil fractions and the total concentration as predictors of their quantification by comparing the classical extractants DTPA, Mehlich-1 and HCl. Comparisons were made also with the concentrations of absorbed by rice and soybean in contaminated soil. Seven soil samples with a different degree of contamination were studied using a randomized experimental design, with four replicates. By using an ICP-OES we analyzed the concentrations of Cu and Zn in the diagnostic leafs, at the end of the cycle (LCE) and several of its content in the soil: available extracted with the DTPA, Mehlich-1 and HCl extractants, soluble+exchangeable contents, bound to organic matter, to oxides and the total content. For both, soybean and rice, the concentrations of Cu and Zn extracted from the sequential extraction was found to be correlated with the concentration in LCE. For soybean, Zn concentration extracted with DTPA was correlated with the total concentration, while Cu concentration extracted with three extractors, DTPA, Mehlich-1 and HCl, correlated with the total concentration, probably due to the high concentration of Cu and Zn in this soil. For rice, both Cu and Zn concentration as extracted by the three extracting solutions correlated with the concentration of all the fractions and with the total concentration.Os elementos traços são potencialmente tóxicos para o meio ambiente. Estas toxicidades dependem de suas associações químicas. Por isso a determinação da forma química destes elementos no solo é importante para quantificá-lo. O objetivo do presente trabalho foi avaliar a possibilidade de se utilizar teores de Cu e Zn nas diferentes frações do solo para prognosticar suas disponibilidades. Para isso, compararam-se as mesmas com soluções extratoras clássicas, como DTPA, Mehlich-1 e HCl, e com teores absorvidos por plantas de arroz e soja em materiais de solos contaminados. Foram estudadas sete amostras de solos com diferentes graus de contaminação empregando delineamento experimental inteiramente casualizado, com quatro repetições. Utilizando a técnica de ICP-OES, foram avaliados teores de Cu e Zn em folha diagnóstico e folha em final de ciclo (LCE) e no solo: teores disponíveis utilizando as soluções extratoras DTPA, Mehlich-1 e HCl, teores nas frações de solo solúvel+trocável, ligados à matéria orgânica e ligados a óxidos e o teor total. Para a soja e arroz, os teores de Cu e Zn extraídos do fracionamento correlacionaram significativamente com os teores obtidos na LCE. Para a soja, os teores de Zn extraídos com DTPA apresentaram alta correlação com os teores totais, enquanto que os teores de Cu extraídos pelos três extratores, DTPA, Mehlich-1 e HCl, correlacionaram com o teor total, provavelmente devido aos altos teores de Cu e Zn neste solo. Para o arroz, os teores de Cu e Zn extraídos pelas três soluções correlacionaram com teores em todas as frações e com o teor total.

No Brasil são cultivadas duas espécies de café: Coffea arabica L. e Coffea canephora Pierre. As pesquisas com adubação com Zn têm sido feitas, principalmente, com cultivares arábica. Esta pesquisa foi realizada com objetivo de obter a relação entre os teores de Zn disponível pelos extratores DTPA e Mehlich-1 em plantas de C. arabica cv. Mundo Novo IAC 379-19 (MN) e C. canephora cv. Apoatã IAC 2258 (AP), bem como em plantas enxertadas (MN/AP). Os tratamentos foram obtidos pelo fatorial 3 x 3, entre materiais genéticos (MN, AP e MN/AP) e doses de Zn (0, 10 e 20 mg dm-3). O teor de Zn na planta, em relação à disponibilidade do nutriente no solo, independentemente dos extratores, varia com a espécie e a combinação entre espécies e a enxertia. Os extratores DTPA e Mehlich-1 apresentaram eficiência semelhante para determinar o teor de Zn disponível no solo, independentemente da espécie (C. arabica e C. canephora). A absorção máxima de Zn ocorreu com teor disponível de 5,6 mg dm-3 (DTPA) e 6,6 mg dm-3 (Mehlich-1) para a cultivar Mundo Novo (C. arabica). Para a espécie C. canephora cv. Apoatã e nas plantas enxertadas (MN/AP), não foi estabelecida a máxima absorção de Zn, independentemente dos extratores, nas doses utilizadas no experimento.Two species of coffee (Coffea arabica L. and Coffea canephora Pierre) are cultivated in Brazil, but most research on Zn fertilization to date has focused on C. arabica. This study was carried out to determine the functional relationship between soil Zn availability determined by DTPA and Mehlich-1 extractors and Zn content in coffee plants belonging to the species C. arabica, cv. Mundo Novo IAC 379-19 (MN) and C. canephora, cv. Apoatã IAC 2258 (AP), as well as grafted plants (MN/AP). The treatments were a 3 x 3 factorial combination of cultivars (MN, AP and MN/AP) and Zn doses (0, 10 and 20 mg dm-3). The plant Zn content, in relation to soil Zn availability, does not depend on the extractant, but varies with the coffee species or grafted species combination. The DTPA and Mehlich-1 extractants were similarly efficient to quantify the soil Zn availability, independent of the coffee species (C. arabica and C. canephora). Zn uptake peaked at soil Zn contents of 5.6 mg dm-3 (DTPA) and 6.6 mg dm-3 (Mehlich-1) for Mundo Novo (C. arabica) cultivar. Based on the Zn doses employed in the present study, the maximum Zn uptake of C. canephora (cv. Apoatã) and grafted plants (MN/AP) could not be determined, independently of the soil extractants.

Cobre, hierro, manganeso y zinc son cuatro metales esenciales para el crecimiento vegetal. A pesar de las pequeñas cantidades requeridas por las plantas, los suelos agrícolas suelen ser deficitarios en uno o más micronutrientes de forma que su concentración en los tejidos de los vegetales cae por debajo de los niveles que permiten un crecimiento óptimo. La naturaleza del suelo juega un papel fundamental en la disponibilidad de micronutrientes y en su comportamiento a nivel suelo-planta. Los objetivos planteados en el presente estudio son: a) establecer la relación entre los parámetros edáficos y la dinámica de los metales dentro del perfil del suelo, y b) determinar la biodisponibilidad y zonas de deficiencia de micronutrientes en suelos agrícolas y suelos con riesgo de salinización. El porcentaje de materia orgánica es el factor determinante en el contenido y distribución de los micronutrientes en el suelo objeto de estudio, siendo el horizonte superficial el de mayor acumulación. Tanto CuDTPA, FeDTPA como MnDTPA tienen cierta movilidad en el perfil, mientras que ZnDTPA permanece adsorbido sin un desplazamiento vertical. El ZnDTPA es el único metal que además, muestra diferencias como consecuencia de la salinidad y granulometría de los suelos. No obstante, las condiciones geoquímicas del suelo implican una baja extractabilidad y una cierta dificultad de absorción de los micronutrientes por parte de las plantas.Copper, iron, manganese and zinc are among the essential elements for plant growth. Despite the small amounts required by plants, agricultural soils are usually deficient in one or more of these micronutrients. Therefore, their concentration in plant tissues falls below the optimum levels. Soil nature plays a fundamental role in the availability of micronutrients and their behavior at a soil-plant level. The aims of this paper were: a) to establish the relationship between soil properties and micronutrient dynamics within the soil profile and b) to determine the plant availability and areas of deficiency in agricultural soils with risk of salinization. The percentage of organic matter was the determining factor in the presence and distribution of the available metals in the soils of the studied area, being the top horizon the one of greatest accumulation. CuDTPA, FeDPTA and MnDPTA were mobile within the profile, whereas ZnDPTA remained adsorbed without vertical displacement. ZnDTPA was the only available metal which also showed differences due to the soil salinity and textural classes. However, soil geochemical conditions imply low extractability and a certain difficulty for micronutrient absorption by plants.

Este trabalho teve como objetivo descrever os teores totais e disponíveis de cobre, ferro, manganês e zinco e suas relações com a acidez, fertilidade, textura e mineralogia de latossolos sob pastagens na Região do Cerrado. Os solos estudados foram amostrados em três regiões: às margens das rodovias GO-060 e BR-154, entre os municípios de Goiânia, GO, e Barra do Garças, MT; no Distrito Federal, e nos municípios de Unaí e Paracatu, noroeste de Minas Gerais. Coletaram-se 54 amostras na camada de 0-20 cm. Relacionaram-se as quantidades disponíveis de Cu, Fe, Mn e Zn (extraídos com DTPA) com seus teores totais, textura, mineralogia e variáveis químicas dos solos, por meio da análise de componentes principais. Os teores totais e disponíveis desses elementos foram extremamente variáveis. A disponibilidade de Fe, Cu e Mn se relacionou principalmente com os teores de ferro cristalino e com o pH em água. A disponibilidade de Zn se relacionou principalmente com a capacidade de troca catiônica do solo. O Zn é, entre os micronutrientes avaliados, o mais freqüentemente limitante ao desenvolvimento das pastagens na Região do Cerrado.The objective of this work was to describe the total and available Cu, Fe, Mn and Zn contents, and their relation with the oxisols acidity, fertility, texture and mineralogy under Cerrado pastures. The soil samples were taken from three regions: along the highways GO-060 and BR-154, between the towns of Goiânia, GO, and Barra do Garças, MT; in the northeast of the State of Minas Gerais, in the towns of Unaí and Paracatu, MG; and in the Federal District. Fifty-four soil samples were collected from the 0-20 cm layer. Available quantities of Cu, Fe, Mn and Zn (DTPA extracted) were related to: total contents, chemical variables, soils texture and mineralogy, through the analysis of the principal components. The available and total Cu, Fe, Mn and Zn content varied greatly. The availability of Fe, Cu and Mn related mainly to the crystalline iron and pH in water. The availability of Zn was mainly related to the soil exchange capacity. Zn was considered the most frequent limiting micronutrient for Cerrado pasture development.

One of the most viable strategies to restore metal contaminated soils is the introduction of plants specialized in their accumulation or able to tolerate very high metal concentrations. This research evaluated: i. the maize as a Pb-accumulator plant; ii. the effects of EDTA-chelating agent for Pb-uptake by maize; iii. amending effect of EDTA on the soil Pb-availability using different extracts. Treatments consisted of Pb rates (100; 200; 350; 1,200 and 2,400 mg kg-1) applied to a Rhodic Hapludox in the form of Pb3(NO)2 with (0.5 g kg-1) and without EDTA. Lead concentrations were determined in maize plant shoots. Soil available Pb was obtained using DTPA, Mehlich-3 and saturation solutions methods. Ionic speciation in the soil solution was performed using the software Visual-Minteq. Although a low t value was found (t 1,500 mg kg-1 of Pb) in maize shoots regardless of EDTA addition. Maize plants treated with EDTA had lower dry matter yield, mainly due to toxic levels of Fe and Al of the Oxisol. All extracting solutions were effective to determine available Pb in soil samples, but the saturation extract is a more difficult and time consuming procedure. At low and medium Pb levels, the plants grew less on EDTA, therefore the phytoextration process was less efficient. The addition of EDTA to the soil is not recommended with the purpose of increasing Pb absorption by maize plants.Uma das estratégias mais viáveis para a descontaminação de solos é a introdução de plantas especializadas na acumulação ou que toleram altas concentrações de metais. Nesse estudo avaliaram-se: i. o potencial acumulador de Pb de plantas de milho; ii. os efeitos do EDTA na absorção de Pb pelo milho; iii. o efeito do EDTA na disponibilidade de Pb utilizando diferentes extratores. Os tratamentos consistiram em doses de Pb (100; 200; 350; 1.200 and 2.400 mg kg-1) aplicados em um Latossolo na forma de Pb3(NO)2 com (0.5 g kg-1) e sem EDTA. A concentração de Pb foi determinada na parte aérea das plantas de milho, e no solo determinou-se o Pb disponível pelos métodos DTPA, Mehlich-3 e pasta de saturação. A especiação iônica da solução do solo foi determinada utilizando-se o software Visual-Minteq. Embora tenha sido encontrado um baixo valor t (t 1.500 mg kg-1), independente da adição de EDTA. As plantas de milho que receberam EDTA apresentaram redução na massa seca, principalmente devido aos níveis tóxicos de Fe e Al do Latossolo. Todas as soluções extratoras utilizadas foram eficientes em determinar o Pb disponível nas amostras de solo, mas a pasta de saturação foi o processo mais trabalhoso. Em baixa e média concentração de Pb no solo as plantas cresceram menos com EDTA, portanto a fitoextração foi menos eficiente. Não é recomendada a adição de EDTA no solo buscando aumentar a absorção de Pb pelas plantas de milho.

The costs related to the construction and maintenance of industrial landfills, and the environmental risks that they may represent, have increased the interest of several types of industries in studying the possibility of applying residues to agricultural soils. This study evaluates the efficiency of flue dust as a zinc source for corn, and the zinc availability for corn evaluated by four methods. A greenhouse experiment carried out at Campinas, SP, Brazil, evaluated the effect of two zinc sources (flue dust and zinc sulphate), at three rates (5, 50 and 150 mg dm-3), in one soil (Rhodic Hapludox) under two pH conditions (5.0 and 6.0). The treatments were arranged in a randomized factorial scheme design with three replications. Zinc availability indexes were determined by the pH 7.3 DTPA, Mehlich-1, and Mehlich-3 methods. The free Zn2+ activity in soil solution was calculated by the MINTEQ computer model. The extraction methods and the activity of the free ion Zn2+ were equally reliable to evaluate zinc availability in the soil amended with flue dust. More than 70% of the total Zn present in the saturation extract was in the free ion form, and the remainder was mainly complexed to SO4(2-) and OH-, independent of soil pH. Flue dust is a zinc supplier to plants. All tested methods were efficient in evaluating Zn availability for corn, independently of soil pH.Os custos com a construção e manutenção de aterros industriais e os riscos ambientais que podem representar têm aumentado o interesse de vários tipos de indústrias em estudar a viabilidade de aplicação de resíduos no solo agrícola. Este trabalho avalia a eficiência do pó de aciaria quanto ao suprimento de zinco para o milho e a disponibilidade desse metal comparada por quatro métodos de extração. O experimento foi conduzido em casa de vegetação em Campinas, SP, Brasil, avaliando o efeito de duas fontes de zinco (pó de aciaria e sulfato de zinco), em três doses (5, 50 e 150 mg dm-3) e um solo (Latossolo Vermelho) com dois valores de pH (5,0 e 6,0). Os tratamentos foram distribuídos em esquema fatorial com três repetições. A disponibilidade de zinco foi determinada por DTPA pH 7.3, Mehlich-1 e Mehlich-3 e a atividade do Zn2+ livre na solução do solo foi calculada pelo modelo MINTEQ. Nos dois valores de pH estudados, tanto a atividade do Zn2+ como os três métodos de extração foram igualmente eficientes em avaliar a disponibilidade de zinco para as plantas em solos tratados com pó de aciaria. Mais que 70% do Zn total presente no extrato de saturação estava como íon livre e o restante complexado com SO4(2-) e OH-, independente do pH do solo. O pó de aciaria é uma fonte de zinco para as plantas. Todos os métodos testados foram eficientes em estimar a disponibilidade de Zn para o milho, independente do pH

O objetivo deste trabalho foi avaliar o efeito da adição de Ni ao solo (0, 2,3, 10,5, 47 e 210 mg kg-1), na presença e ausência de calcário, sobre: o desenvolvimento do feijoeiro; a fitodisponibilidade de Ni e algumas características biológicas do solo. O experimento foi conduzido em casa de vegetação, em Latossolo Vermelho distrófico. A dose de Ni de 210 mg kg-1 causou a morte de todas as plantas, tanto na presença como na ausência de calcário. Houve aumento da produção de grãos de feijão no tratamento que recebeu calcário. A concentração de Ni dos grãos aumentou com o incremento de Ni no solo, ultrapassando o limite máximo permitido, de 5 mg kg-1 de matéria fresca, na dose de 2,3 mg kg-1, indicando que a aplicação de calcário não foi suficiente para reduzir os teores de Ni no grão de feijão a níveis apropriados para o consumo. Observou-se diminuição da biomassa microbiana do solo nos tratamentos com altas concentrações de Ni, que foi acompanhada por aumento no qCO2. O qCO2 foi um indicador adequado do grau de estresse que teve a comunidade microbiana do solo com a adição de Ni.The aim of this work was to evaluate the effect of Ni addition (0, 2.3, 10.5, 47 and 210 mg kg-1), in the presence and absence of lime, on: common beans development, Ni phytoavailability, and soil biological characteristics. A greenhouse experiment was conducted using a sample of a Rhodic Hapludox. Rate of 210 mg kg-1 of Ni caused plant death in both the absence and the presence of lime. Grain yield of common beans was higher in treatments with lime addition. However, grain Ni concentration increased with Ni addition, exceeding the maximum admissible value, of 5 mg kg-1 (fresh weight), already at rate of 2.3 mg kg-1. Lime addition was not enough to reduce grain Ni concentrations to permissible levels for consumption. The addition of high concentrations of Ni decreased soil microbial biomass, and this reduction was accompanied by an increase in the metabolic quocient. The qCO2 was an adequate indicator of the stress level caused by Ni addition on soil microbial community.

OBJECTIVE: The aim of this study was to compare the renal function measured with either 99mTc-DTPA or 99mTc-EC dynamic scintigraphies with that measured using 99mTc-DMSA static scintigraphy. METHODS: the values of relative renal function measured in 111 renal dynamic scintigraphies performed either with 99mTc-DTPA (55 studies) or with 99mTc-EC (56 studies) were compared with the relative function measured using 99mTc-DMSA static scintigraphy performed within a 1-month period. The comparisons were performed using Wilcoxon signed rank test. The number of 99mTc-DTPA and 99mTc-EC studies that presented relative renal function different by more than 5% from that measured with 99mTc-DMSA, using chi square test were also compared. RESULTS: the relative renal function measured with 99mTc-EC is not statistically different from that measured with 99mTc-DMSA (p = 0.97). The relative renal function measured with 99mTc-DTPA was statistically different from that measured using 99mTc-DMSA, but with a borderline statistical significance (p = 0.05). The number of studies with relative renal function different by more than 5% from that measured with 99mTc-DMSA is higher for the 99mTc-DTPA scintigraphy (p = 0.04) than for 99mTc-EC. CONCLUSION: the relative renal function measured with 99mTc-EC dynamic scintigraphy is comparable with that measured with 99mTc-DMSA static scintigraphy, while the relative renal function measured with 99mTc-DTPA dynamic scintigraphy presents a significant statistical difference from that measured with 99mTc-DMSA static scintigraphy.

Agricultural recycling of sewage sludge has been a source of accumulation of heavy metals in the environment which may reach toxic levels and cause serious damage to the biota. Field experiments were undertaken for two agricultural years (2000 and 2002) and effects of two sewage sludge applications were evaluated through the extraction of (essential and non-essential) transition metals by diethylenetriaminepentaacetic acid (DTPA) extractor in a medium texture dystrophic Dark Red Latosol. Cd, Ni, Co, Pb and Cr were not detected. Application of sewage sludge initially caused a slight pH rise in the soil; later pH lowered and kept itself close to the starting level. It could be concluded that through consecutive sludge application, extractable rates of Fe and Mn in soil samples gradually increased during the two agricultural years in proportion to sewage sludge doses and sampling period. In fact, they were higher than rates of control. Due to low concentrations of soil samples, extractor had a restricted capacity for evaluation of its phytoavailability.A reciclagem agrícola do lodo de esgoto tem provocado o acúmulo de metais pesados no solo e na água, podendo atingir níveis tóxicos e causar danos às plantas cultivadas, aos animais e ao homem, por meio da cadeia trófica. Neste intuito foi desenvolvido o presente experimento, em condições de campo, entre 2000 e 2002, onde foram avaliados os efeitos da aplicação de lodo de esgoto por dois anos, sobre a extração de metais de transição (essenciais e não) pelo extrator DTPA em um Latossolo Vermelho distrófico (LVd) de textura média. As concentrações dos elementos metálicos: Mn, Fe, Cd, Ni, Co, Pb e Cr não foram detectados pelo método da absorção atômica na solução obtida com o extrator DTPA. A aplicação de lodo de esgoto causou inicialmente pequena elevação no pH do solo, posteriormente a diminuição do mesmo, e manteve-se próximo ao original. Foi possível concluir que, com a aplicação consecutiva do lodo, os teores extraíveis de Fe e Mn nas amostras de solos aumentaram gradativamente nos dois anos agrícolas, com as doses do lodo de esgoto aplicado, época de amostragens, e foram superiores ao tratamento testemunha. O extrator apresentou capacidade restrita para avaliação da fitodisponibilidade dos metais pesados decorrentes das baixas concentrações nas amostras de solo.

A avaliação do método modificado da resina de troca de íons para extração de Mn e Fe dos solos foi o objetivo desta pesquisa. Foram utilizadas 44 amostras de solo, cujos teores de Mn variaram de baixos a altos e de Fe de médios a altos. Como plantas-teste, utilizaram-se o milho e a soja, cultivadas em casa de vegetação. O Fe e o Mn do solo foram determinados, usando o método modificado da resina de troca de íons, DTPA, AB-DTPA, Mehlich-1 e Mehlich-3. Os coeficientes de correlação entre Mn no solo e Mn acumulado na parte aérea da soja foram: resina (0,62*), DTPA (0,58*), Mehlich-3 (0,54*), Mehlich-1 (0,51*) e AB-DTPA (0,26NS). Para o milho, houve correlação entre Mn-solo e Mn-planta somente nas amostras de solo com baixos teores desse elemento, para todos os extratores, exceto para AB-DTPA. Concluiu-se que a resina foi tão eficiente quanto os extratores DTPA, M-1 e M-3 em avaliar a disponibilidade de Mn para a soja, e que nenhum extrator foi eficiente em avaliar a disponibilidade de Fe para as plantas de milho e soja, com 53 dias de idade, cultivadas em casa de vegetação.The objective of this research was to evaluate a modified ion exchange resin method for Mn and Fe extraction from soils. Forty-four soil samples presenting low, medium, and high Mn and medium to high Fe concentrations were used. Maize and soybeans plants were grown as test plants in a pot experiment in a greenhouse. Soil samples were analyzed for Mn and Fe using the modified ion exchange resin, DTPA, AB-DTPA, Mehlich-1, and Mehlich-3 methods. The correlation coefficients between soil Mn and Mn accumulated in the soybean shoot were: ion exchange resin (0.62*), DTPA (0.57*), Mehlich-3 (0.54*), Mehlich-1 (0.51*), and AB-DTPA (0.26). For maize, significant correlation coefficients between soil Mn and plant-Mn were obtained only when low-initial Mn soil samples were considered for all extractants, except for AB-DTPA. For soybeans, the modified ion exchange resin method was as efficient as DTPA, Mehlich-1 and Mehlich-3 for the evaluation of soil Mn availability. None of the methods was efficient for evaluating the soil Fe availability for the 53 day-old maize and soybean plants grown in greenhouse.

Contents of heavy metal on agricultural soils have been raised by land applications of sewage sludge and may constitute a hazard to plants, animals and humans. A field experiment was carried out from 1983 to 1987, to evaluate the long-term effect of sewage sludge application, with and without liming, on heavy metal accumulation and availability in a Rhodic Hapludox soil grown with maize (HMD 7974 hybrid). Trials were set up in a completely randomized blocks design with four replications. Each block was split in two bands, one with and another without liming. The sludge was applied in each band at rates: 0, 20, 40, 60 and 80 Mg ha-1 (dry basis) in a single application; and 40, 60 and 80 Mg ha-1 split in two, three and four equal yearly applications, respectively. The soil was sampled for chemical analysis each year after harvest. Soil samples were analysed for Cu, Ni and Zn in extracts obtained with DTPA and Mehlich-3 solutions, and in extracts obtained by digestion with nitric-perchloric acid (total metal contents), using an inductively coupled plasma (ICP) spectrometer. In general, Zn, Cu and Ni concentrations in DTPA and Mehlich-3 extracts increased linearly with sludge application. Total Cu and Zn concentrations increased when sludge was applied, whereas total Ni concentrations were not affected. Both extractants were suitable to evaluate Cu and Zn availability to corn in the soil treated with sewage sludge. Liming reduced the DTPA extractability of Zn. DTPA-extractable Cu concentrations were not significantly affected by liming. Mehlich-3-extractable Cu and Zn concentrations increased with liming. Only DTPA extractant indicated reduction of Ni concentrations in the soil after liming.