Сорбция фосфатов оксигидратами железа (ІІІ) разной модификации

Методами осадження синтезовано FeOOH (аморфний оксигідроксид заліза), α-FeOOH (гетит) і γ-FeOOH (лепідокрокіт). Фізико-хімічні параметри синтезованих сполук було охарактеризовано із залученням рентгенівських досліджень, порометрії, рН-потенціометрії. За допомогою рентгенограм встановлено, що α-FeOOH і γ-FeOOH мають кристалічну структуру, тоді як FeOOH аморфний. Вивчено сорбційну активність оксигідратів заліза різної модифікації відносно фосфат-йонів. Синтезовані оксигідрати заліза мають мезопористу структуру з переважними розмірами пор 2 нм для FeOOH (аморфного)і γ-FeOOH та 16 нм для α-FeOOH. рН-метричні дослідження показали, що FeOOH (аморфний) є амфолітом із максимальною обмінною ємністю 3 ммоль/г у кислому та 3,5 ммоль/г у лужному середовищах. Порівняльна оцінка сорбційної здатності оксигідратів заліза різної модифікації відносно фосфат-йонів виявила, що найкращі показники має FeOOH (аморфний), сорбційна ємність якого дорівнює 237,5 мг/г у кислому і 104,5 мг/г у лужному середовищах.By means of precipitation method FeOOH (amorphous ferric oxyhydrate), α-FeOOH (goethite) and γ-FeOOH (lepidocrocite) have been synthesized. Physical-and-chemical parameters of the synthesized compounds have been characterized using X-ray diffraction, porosity studies, pH titration. With the aid of XRD it was found that α-FeOOH and γ-FeOOH have crystalline structure, while FeOOH is amorphous. The sorption affinity of ferric oxyhydrates of various crystalline structure towards phosphate ions has been studied. The synthesized oxyhydrates have a mezoporous structure with the pore size of 2 nm for FeOOH (amorphous), γ-FeOOH and 16 nm for α-FeOOH. рН titration has shown that FeOOH (amorphous) is an ampholite with the maximal exchange capacity of 3 mmol/g in acidic media and 3,5 mmol/g in alkaline media. The comparison of the sorption affinity of the ferric oxyhydrates with various crystalline structures towards phosphate ions shows that FeOOH (amorphous) has the best parameters, and its sorption capacity reaches 237,5 mg/g in acidic media and 104,5 mg/g in alkaline media.Методами осаждения синтезированы FeOOH (аморфный оксигидрат железа), α-FeOOH (гетит) и γ-FeOOH (лепидокрокит). Физико-химические параметры синтезированных соединений были охарактеризованы с использованием рентгеновских исследований, порометрии, рН-метрии. С помощью рентгенограмм установлено, что α-FeOOH и γ-FeOOH имеют кристаллическую структуру, тогда как FeOOH - аморфен. Изучена сорбционная активность оксигидратов железа различной модификации по отношению к фосфат-ионам. Синтезированные оксигидраты железа обладают мезопористой структурой с преобладающими размерами пор 2 нм для FeOOH (аморфного), γ-FeOOH и 16 нм для α-FeOOH. рН-метрические исследования показали, что FeOOH (аморфный) является амфолитом с максимальной обменной емкостью 3 ммоль/г в кислой и 3,5 ммоль/г щелочной средах. Сравнительная оценка сорбционной способности оксигидратов железа разной модификации по отношению к фосфат-ионам выявила, что наилучшие показатели имеет FeOOH (аморфный), сорбционная емкость которого достигает 237,5 мг/г в кислой и 104,5 мг/г в щелочной средах

Bioaccumulation and ecotoxicity of carbon nanotubes

Carbon nanotubes (CNT) have numerous industrial applications and may be released to the environment. In the aquatic environment, pristine or functionalized CNT have different dispersion behavior, potentially leading to different risks of exposure along the water column. Data included in this review indicate that CNT do not cross biological barriers readily. When internalized, only a minimal fraction of CNT translocate into organism body compartments. The reported CNT toxicity depends on exposure conditions, model organism, CNT-type, dispersion state and concentration. In the ecotoxicological tests, the aquatic organisms were generally found to be more sensitive than terrestrial organisms. Invertebrates were more sensitive than vertebrates. Single-walled CNT were found to be more toxic than double-/multi-walled CNT. Generally, the effect concentrations documented in literature were above current modeled average environmental concentrations. Measurement data are needed for estimation of environmental no-effect concentrations. Future studies with benchmark materials are needed to generate comparable results. Studies have to include better characterization of the starting materials, of the dispersions and of the biological fate, to obtain better knowledge of the exposure/effect relationships

Drought Impact Is Alleviated in Sugar Beets (Beta vulgaris L.) by Foliar Application of Fullerenol Nanoparticles

Over the past few years, significant efforts have been made to decrease the effects of drought stress on plant productivity and quality. We propose that fullerenol nanoparticles (FNPs, molecular formula C-60(OH)(24)) may help alleviate drought stress by serving as an additional intercellular water supply. Specifically, FNPs are able to penetrate plant leaf and root tissues, where they bind water in various cell compartments. This hydroscopic activity suggests that FNPs could be beneficial in plants. The aim of the present study was to analyse the influence of FNPs on sugar beet plants exposed to drought stress. Our results indicate that intracellular water metabolism can be modified by foliar application of FNPs in drought exposed plants. Drought stress induced a significant increase in the compatible osmolyte proline in both the leaves and roots of control plants, but not in FNP treated plants. These results indicate that FNPs could act as intracellular binders of water, creating an additional water reserve, and enabling adaptation to drought stress. Moreover, analysis of plant antioxidant enzyme activities (CAT, APx and GPx), MDA and GSH content indicate that fullerenol foliar application could have some beneficial effect on alleviating oxidative effects of drought stress, depending on the concentration of nanoparticles applied. Although further studies are necessary to elucidate the biochemical impact of FNPs on plants; the present results could directly impact agricultural practice, where available water supplies are often a limiting factor in plant bioproductivity

Complex genetic, photothermal, and photoacoustic analysis of nanoparticle-plant interactions

Understanding the nature of interactions between engineered nanomaterials and plants is crucial in comprehending the impact of nanotechnology on the environment and agriculture with a focus on toxicity concerns, plant disease treatment, and genetic engineering. To date, little progress has been made in studying nanoparticle-plant interactions at single nanoparticle and genetic levels. Here, we introduce an advanced platform integrating genetic, Raman, photothermal, and photoacoustic methods. Using this approach, we discovered that multiwall carbon nanotubes induce previously unknown changes in gene expression in tomato leaves and roots, particularly, up-regulation of the stress-related genes, including those induced by pathogens and the water-channel LeAqp2 gene. A nano-bubble amplified photothermal/photoacoustic imaging, spectroscopy, and burning technique demonstrated the detection of multiwall carbon nanotubes in roots, leaves, and fruits down to the single nanoparticle and cell level. Thus, our integrated platform allows the study of nanoparticles’ impact on plants with higher sensitivity and specificity, compared to existing assays

Morphological assessment of colon polyp using flexible spectral imaging color enhancement

The article is devoted to the study of the efficacy of the flexible spectral imaging color enhancement (FICE) in the visual assessment of the polyp morphology. A group of 166 patients had undergone screening colonoscopy, which showed polyps of different sizes and histological structure in different parts of the intestine. The accuracy of the visual assessment of the polyp type performed using FICE was compared with the histological examination results. 255 polyps in various parts of the colon were identified in 166 patients. Comparative analysis of the results of visual assessment and histological examination of the identified polyps showed that the diagnoses agreed in 190 (74.5%) cases, and preliminary diagnoses proved to be erroneous in 65 (25.5%) cases. The size of the polyp was found to be inversely correlated with the number of erroneous diagnoses, i.e. the smaller the size of the polyp, the greater the probability of error. The erroneous diagnosis was made most frequently in the cases of small and smallest tubular adenomas and hyperplastic polyps, which were taken as serrated one (p <0.05 – significant differences), and also in the case of small and smallest hyperplastic polyps, which were taken as tubular ones (p < 0.05). Based on the results of evaluation of the FICE informativeness in the visual assessment of colon polyps, the method has been shown to have high diagnostic accuracy with respect to tubular, serrated and hyperplastic polyps equal to 83.1, 81.2, 83.9%, respectively. The study showed the high efficacy of flexible spectral imaging colour enhancement in recognizing the morphological structure of epithelial neoplasms, which can be used as a screening method for the preliminary classification of colonic epithelial neoplasia