Search

Plant biostimulants, an emerging class of agricultural inputs, are complex products. The reproducibility of their specific action on plant metabolism and plant physiology, which lead to an enhanced nutrient use efficiency, stress tolerance and edible yield quality, is still a challenge. Development of quality insurance systems for plant biostimulants need complex investigation based on adapted analytical, physico-chemical and chemical methods. The objective of this work was to characterize commercial humate biostimulants through different analytical techniques (Fourier transform infrared spectroscopy - FTIR, thermogravimetric analysis- TGA) and to evaluate their textural and chemical (pH, C, N, humic acids, inorganic components) parameters. The first derivative curve from TG analysis showed decomposition of different compounds, classified according to the results obtained by FTIR. The humic substances determined by TGA method was comparable with the results obtained by gravimetric reference method. The inductively coupled plasma-optical emission spectrometry (ICP-OES) technique was applied to determine the inorganic elements either from the production process of humate or from raw materials, as well as for the control of humate in terms of requirements for safety and quality. Their complementary properties obtaining through different analytical techniques provide essential information on the chemical characteristics of the humate plant biostimulant formulations.

In the present work, it was developed a simple, cheap and quick method for Sb determination from mineral water, using ICP-OES, using two different calibration proceedings: calibration curve method (CCM) and standard additions method (SAM). On the studied concentration range, the parameters such as the calibration curve slope, linearity expressed through correlation coefficient r = 0.9992, limits of detection LoD = 0.67 �g L-1 and quantification LoQ = 2.01 �g L-1, the standard deviation of repeatability of 0.25 �g L-1, the accuracy of 0.16 �g L-1 satisfy the performance criteria. The value of extended uncertainty with a confidence level of 95 % (k = 2), is 1.0 �g L-1 obtained for Sb content of 4.10 �g L-1. The mineral waters were analyzed also by the addition standard method. One of the advantages of this method is to eliminate interference from the matrix. By the method of standard additions, the detection limit decreased from LoD=0.67 �g L-1 to 0.16 �gL-1.

In the present work it was developed a simple, cheap and quick method for Sb determination from PET in the 10 - 500 mg Kg-1concentrations range, using an original digestion method coupled with the ICP-OES technique. The digestion method, developed and optimized for this study, uses a single digestion reagent (HNO3), adequate the measurement equipment. It ensures a reduced digestion time (45 min.), thus having small energy consumption (0.15 KWh/sample) and uses standard digestion equipment. On the studied concentration range the method presents the following characteristics the calibration curve slope, expressed through correlation coefficient r = 0.9999, standard deviation of repeatability of 1.27 mg Kg-1, RSD = 0.49 %, accuracy determined by recovery degree ranges between 85 % and 96 %, all being comparable with literature data. The value of extended uncertainty is 8.4 mg Kg-1with a confidence level of 95 % (k=2), obtained for Sb content of 259.6 mg Kg-1. The applicability of the method can be extended with the same digestion method and adequate modification of the concentration range for the calibration curve. The validated method for antimony content from PET cans can be applied in various research studies.

In this work, Sb (III) adsorption on oxidized exfoliated graphite nanoplatelets (ox-xGnP) was evaluated for the first time, to the best of our knowledge. The ox-xGnP were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), Brunauer&ndash, Emmet&ndash, Teller (BET) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) equipped with energy-dispersive X-ray spectroscopy (EDX), and Zeta potential analysis. The adsorption parameters, such as pH and contact time, were optimized, and the best adsorption capacity obtained was 8.91 mg g&minus, 1 at pH = 7.0, 1.0 mg ox-xGnP/100 mL solution, T = 293 K, 1.0 mg L&minus, 1, Sb (III), 25 min contact time. The best correlation of the kinetic data was described by a pseudo-first-order kinetic model, with R2 = 0.999. The adsorption isotherms of Sb (III) onto ox-xGnP were best described by the Langmuir isotherm model. The thermodynamic parameters showed that the adsorption process was exothermic and spontaneous.

Hemophagocytic lymphohistiocytosis (HLH) is a very severe and rare syndrome of pathologic immune activation characterized by cytopenia and clinical signs and symptoms of extreme inflammation. HLH is usually fatal without treatment so that accurate and timely diagnosis is very important. The syndrome occurs as a familial disorder (familial HLH - FLH) or as an acquired condition (secondary - sHLH) in association with a variety of pathologic states: infections, rheumatologic, malignant or metabolic diseases. Malignancy associated HLH is primarily reported in T÷NK (natural killer)-cell malignancies but also in B-cell neoplasms and other types of cancer. HLH has also been reported in rare cases as a highly fatal and difficult to diagnose complication of stem cell transplantation (SCT). In this paper, we present the case of a young male patient who underwent autologous SCT as consolidation therapy for a T÷NK-cell lymphoma, complicated with graft failure due to HLH. The patient was successfully treated with corticosteroids, Etoposide, Cyclosporine and immunoglobulins. As a particularity, he developed a second B-cell neoplasia a few months after SCT.

A study of the experimental conditions required to obtain vanadium doped sol-gel TiO2 coatings is presented. Tetraethyl orthotitanate was employed as the TiO2 source and VCl3, VOSO4 · H2O and VOSO4 dissolved H2SO4 where employed as vanadium sources.