Spatial Distribution Of Compounds Research Articles

Mass spectrometry imaging for direct visualization of components in plants tissues.

Mass spectrometry is considered the most informative technique for components identification and has been widely adopted in plant sciences. However, the spatial distribution of compounds in the plant, which is vital for the exploration of plant physiological mechanisms, is missed in MS analysis. In recent years, mass spectrometry imaging has brought a great breakthrough in plant analysis because it can determine both the molecular compositions and spatial distributions, which is conducive to understand functions and regulation pathways of specific components in plants. Mass spectrometry imaging analysis of plant tissue is toward high sensitivity, high spatial resolution, and even single-cell analysis. Despite many challenges and technical barriers, such as difficulties of sample pretreatment caused by morphological diversity of plant tissues, obstacles for high spatial resolution imaging, and so on, lots of researches have contributed to remarkable progress, including improvement in tissue preparation, matrix innovation, and ionization mode development. This review focuses on the advances of mass spectrometry imaging analysis of plants in the last 5 years, including commonly used ionization techniques, technical advances, and recent applications of mass spectrometry imaging in plants.

Application of Raman Spectroscopic Imaging to Assess the Structural Changes at Cell-Scaffold Interface.

Raman spectroscopic imaging and mapping were applied to characterise three-compound ceramic composite biomaterial consisting of chitosan, β-1,3-d-glucan (curdlan) and hydroxyapatite (HA) developed as a bone tissue engineering product (TEP). In this rapidly advancing domain of medical science, the urge for quick, reliable and specific method for products evaluation and tissue–implant interaction, in this case bone formation process, is constantly present. Two types of stem cells, adipose-derived stem cells (ADSCs) and bone marrow-derived stem cells (BMDSCs), were cultured on composite surface. Raman spectroscopic imaging provided advantageous information on molecular differences and spatial distribution of compounds within and between the cell-seeded and untreated samples at a microscopic level. With the use of this, it was possible to confirm composite biocompatibility and bioactivity in vitro. Deposition of HA and changes in its crystallinity along with protein adsorption proved new bone tissue formation in both mesenchymal stem cell samples, where the cells proliferated, differentiated and produced biomineralised extracellular matrix (ECM). The usefulness of spectroscopic Raman imaging was confirmed in tissue engineering in terms of both the organic and inorganic components considering composite–cells interaction.

PAHs in Water, Sediment and Biota in an Area with Port Activities.

The study reports concentration of 16 PAHs in sediment, water, plankton and in muscle and liver of sampled fishes from Paranagua Bay in Southern Brazil. According to the range of PAHs concentration found in sediments (ΣPAHs 15.33-133.61µgg-1) and water (ΣPAHs 51.20-162.37µgL-1), the area was characterized as slightly polluted. In contrast, significant concentration of PAHs was found in fish and plankton, ranging from 26.52 to 2055.00µgg-1 and 175.41 to 2096.10µgg-1, respectively. The concentrations were 15 times more than in sediments. Even though the concentration of PAHs in water and sediments are low, the concentration in fish tissues are alarmingly. The hypothesis of bioaccumulation is not discharged. Accumulation levels of PAHs in the biota were used to calculate biota-sediment accumulation factor (BSAF) and bioaccumulation factor (BAF). For example, fish sampled from site 11 had a BAF of 49 and BSAF of 2.3, whereas for plankton the BAF was 16.3 and BSAF 0.7. Mean values of BAF and BSAF were higher in plankton samples. It is known that PAHs are enzymatically metabolized by organisms, thus the lower BSAF in fish might have resulted from biochemical transformation. Statistical analysis indicates no significant correlation between total PAHs concentration in fish tissues and total lipid content in fishes (p > 0.1).Accumulation in tissues is controlled by lipid content, although factors, such as spatial distribution of compounds, trophic level, and behavior of each species in the environment, must be considered. Besides, size and nutritional conditions can affect both absorption as well as metabolic process and excretion. A positive and significant correlation was found between total PAHs and trophic positions obtained from FishBase data (r2 = 0.784; p < 0.05). Thus, it seems that the area, with great influence of urban and industrial activities, and the bioaccumulation compounds, such as PAHs, depend on others factors, as well as resuspension of sediments and releasing of compounds for biota.

Toxic and mutagenic activities of surface water from the Chumysh River

&lt;p&gt;The Allium test system is worldwide used for biological monitoring of environmental pollutants. We have studied toxic and mutagenic activity of water from the Chumysh River, which is one of the largest tributaries of the Upper Ob. Water samples were taken near industrial settlement Talmenka (Altai Territory of Russia) during the spring flood and low autumn water level in 2015. Root tips of &lt;em&gt;Allium cepa&lt;/em&gt; L. was used as a biological model. There were examined 30 samples. Purified tap water of medium hardness served as a control sample. After the synchronizing the cell divisions, the onion bulbs with roots reaching a length of 2-3 mm were transferred to glass cups containing the selected samples of River water and cultured for several days at a temperature of +24 ± 1°C. After exposure, root tips were rinsed in distilled water and fixed in a cold mixture of ethanol and acetic acid (3:1). Fixed samples were used after 12-24 h or transferred to 70% alcohol and stored in refrigerator at a temperature of +4°C until required. The fixed materials were hydrolyzed in 1N HCl at 60°C for 5-8 min and squashed in aceto-orcein.&lt;strong&gt; &lt;/strong&gt;Prepared slides were viewed under the microscope at a magnification of ×90.&lt;strong&gt; &lt;/strong&gt;The mitotic index (MI), the phase indices, the frequency of abnormal mitosis, and chromosomal aberrations were determined by the examination of 500 cells per a replicate (100 cells per slide). We established that the decreased or increased levels of mitotic activity and the frequencies of pathological mitoses (up to 7.9%, P &amp;lt; 0.05) in onion root tips revealed the presence of mitotoxic and genotoxic agents in the Chumysh River water. We found that the most number of chromosomal abnormalities occurs at the stages of meta- or anaphase. The main abnormalities are chromosome laggings in meta- and anaphase, chromosome bridges, chromosome fragments and micronuclei. Their number increased in 5.0-10.8 times compared with the control value. It has been discovered the temporal and spatial distribution of compounds with different toxicity and genotoxicity within a stream. The greatest level of mitotic depression and the highest frequency of chromosomal mutations were observed in the tissues of the onion root tips germinated on the samples collected in low autumn water. The mechanisms of plant adaptation to unfavorable environmental factors are discussed.&lt;/p&gt;

Integrating hydrodynamics and biokinetics in wastewater treatment modelling by using smoothed particle hydrodynamics

Abstract In this work a novel integrated biokinetic wastewater treatment (WWT) model based on the smoothed particle hydrodynamics (SPH) method as hydraulic model is proposed. Significant outcomes of this work are the computation of a detailed spatial distribution of compounds in WWT basins and the quantification of the effects of the stirrer induced mixing on the evolution of compounds. SPH is a meshfree particle method which herein is applied to compute a treatment plant's reactor hydraulics. The characteristic feature of SPH is to describe a fluid's dynamics by particles that move along with the flow. The present WWT model takes advantage of this principle by assigning the compounds’ concentrations, which are defined by the activated sludge model no. 1, to SPH particles. A full-scale treatment plant simulation with a variable stirrer induced mixing intensity in the denitrification basin is performed. A spatial distribution of the compounds’ concentrations, which up to now was unknown for unsteady flows, is computed and analysed. The developed framework is generic and therefore expected to be applicable for modelling chemical engineering processes which are influenced by hydrodynamic effects.

Modeling Therapy Response and Spatial Tissue Distribution of Erlotinib in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is likely the most aggressive and therapy-resistant of all cancers. The aim of this study was to investigate the emerging technology of matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) as a powerful tool to study drug delivery and spatial tissue distribution in PDAC. We utilized an established genetically engineered mouse model of spontaneous PDAC to examine the distribution of the small-molecule inhibitor erlotinib in healthy pancreas and PDAC. MALDI IMS was utilized on sections of single-dose or long-term-treated mice to measure drug tissue distribution. Histologic and statistical analyses were performed to correlate morphology, drug distribution, and survival. We found that erlotinib levels were significantly lower in PDAC compared with healthy tissue (P = 0.0078). Survival of long-term-treated mice did not correlate with overall levels of erlotinib or with overall histologic tumor grade but did correlate both with the percentage of atypical glands in the cancer (P = 0.021, rs = 0.59) and the level of erlotinib in those atypical glands (P = 0.019, rs = 0.60). The results of this pilot study present MALDI IMS as a reliable technology to study drug delivery and spatial distribution of compounds in a preclinical setting and support drug imaging-based translational approaches. Mol Cancer Ther; 15(5); 1145-52. ©2016 AACR.

Relevant aspects of quantification and sample heterogeneity in hyperspectral image resolution

NIR-infrared chemical imaging (NIR-CI) is a powerful technique to provide spatial and spectral information about the samples analyzed. NIR-CI presents a big potential to obtain accurate and reliable information about the quality of end products and it is also an excellent tool for process control.Quantitative analysis and heterogeneity studies on NIR images are often carried out by multivariate calibration techniques, designed in this context as Multivariate Image Regression (MIR). Multivariate Curve Resolution—Alternating Least Squares (MCR-ALS) is another data analysis method, aimed mainly at recovering the pure spectra and distribution maps of images. This straightforward information can be potentially applied for quantitative purposes and heterogeneity description when image multiset structures are analyzed.In this work, the potential of MCR-ALS to provide quantitative and heterogeneity information has been explored paying special attention to particular aspects, such as the preprocessing used for resolution and the effect of several factors on the global quantitative results, namely: a) the design of the regions of interest (ROIs) included in the multiset image structure, b) the constraints applied in the resolution step and c) the calibration/validation strategy applied. Quantitative information at a pixel level has also been carried out to study the heterogeneity of the samples analyzed, stressing the difference between the constitutional heterogeneity (population statistics describing the quantitative distribution or pixel-to-pixel variability in concentration) and distributional heterogeneity (image maps expressing the variability in the spatial distribution of compounds in the image).To perform the work described above, real NIR images of non-homogeneous mixtures of acetylsalicilyc, caffeine and starch of different compositions have been used.

Identification and localization of volatile hairpencil components in maleAmauris ochlea butterflies (Danaidae)

By gas-chromatography and mass-spectroscopy 7 volatile substances have been found on the abdominal hairpencils ofAmauris ochlea males. 6 substances have been identified. The spatial distribution of compounds is correlated to the 5 types of hairs comprising the scent organ.