Fractional Abundance Research Articles

Geochemical signature of the bed sediments at the outlet of the Ibrahim River (Lebanon): temporal variation

Bed sediments were collected monthly at the outlet of the Ibrahim River between May 2016 and July 2017. Their physical and chemical characteristics were studied to highlight the impact of seasonal variations and discharge on the sediments' geochemical signatures. Granulometric analysis showed that samples collected after rain events contained abundant sand fractions (> 80%), while the clay fraction was more present at the beginning of the dry season, at low monthly average flows (1 m3/s). Ten major elements, 14 rare earth elements (REE), and 30 trace elements (TE) were analyzed. An excess of CaO reflected the contribution of the carbonate rocks of the Ibrahim karstic springs (30.35 ± 3.91%) but CaO concentration decreased during periods of high water. On another hand, no REE enrichment was detected, both in high and low flows. Most sediments collected at low flow had a pronounced REE depletion that occurred particularly for LREE composition (Nd, Pr, Ce, and La). A negative Ce anomaly (0.992) and a positive Eu anomaly (1.313) were revealed with an average La/Yb ratio of 0.570, reflecting a slight enrichment in HREE. Most studied TE were less concentrated than the averages mentioned in PAAS, UCC, and WSA references. However, a Ze enrichment was mainly due to the regional geochemical background, an As enrichment was associated with anthropogenic contribution, and a Zr enrichment was linked to discharges from pharmaceutical industries located at the river outlet. This study still needs to be complemented binding both spatial and temporal criteria for further fluvial sediments' monitoring of the entire catchment area.

Boosting asymmetric charged DM via thermalization

We consider a dark sector scenario with two dark matter species with opposite dark U(1) charges and an asymmetric population comprising some fraction of the dark matter abundance. A new mechanism for boosting dark matter is introduced, arising from the large mass hierarchy between the two particles. In the galaxy, the two species thermalize efficiently through dark Rutherford scattering greatly boosting the lighter dark matter particle, far above the virial and escape velocities in the galaxy, while the dark charge prevents it from escaping. We study the consequences of this scenario for direct-detection experiments, assuming a kinetic mixing between the dark photon and the photon. If the charged dark sector makes up 5% of the total DM mass in our galaxy and the mass ratio is between 103–104, we find that current and future experiments may probe the boosted light dark matter for masses down to 100 keV, in a hitherto unexplored parameter range.

K-shell radiation and bright spot characteristics of high-energy-density Fe-Cr-Ni plasmas influenced by X-pinch load geometry

K-shell radiation is diagnostically advantageous for the study of high-energy-density plasmas. The current work investigates the influence of load geometry on K-shell x-rays in Z-pinch plasmas produced on the 1-MA Zebra generator. Stainless steel (Fe: 69%, Cr: 20%, Ni: 9%) X-pinch wire loads are fielded with an interwire angle of 31° (small-angle) or 62.5° (large-angle), respectively and studied using various x-ray diode, imaging, and spectroscopic diagnostics. The large-angle geometry produced large, individual x-ray-emitting bright spots (> 3 keV) at the wire cross-point averaging areas ≥ 1 mm2, with noteworthy soft x-ray (> 0.75 keV) bursts and radiation yields ≤ 14.6 kJ. The small-angle geometry produced multiple x-ray-emitting bright spots extending the pinch axis with smaller average sizes (≤ 0.5 mm2), consistent with stronger current, increased radiation yield (≥ 15.5 kJ), and notable hard x-ray (> 9 keV) bursts, which peak with largest cumulative bright spot size. Spectroscopic analysis is performed with non-LTE collisional-radiative modeling, indicating a cold, nonthermal plasma region radiating from neutral to Ne-like ions, a hot, thermal region radiating from Fe and Cr He- and Li-like ions, and an intermediate region radiating Kα satellites from Li-like to O-like ions. Modeling of the nonthermal and satellite features imply a fractional hot electron abundance ∼0.1% and ∼0.5% for large- and small-angle geometries, respectively. Relative intensity analysis is performed on Heα and Kα lines, revealing intensity ratios that deviate from the original wire composition. Optical depth estimates allude to optically thick, thermal K-shell plasmas with densities consistent with non-LTE modeling.

Estimation of hazardous and noxious substance (toluene) thickness using hyperspectral remote sensing

A hazardous noxious substance (HNS) spill accident is one of the most devastating maritime disasters as it is accompanied by toxicity, fire, and explosions in the ocean. To monitor an HNS spill, it is necessary to develop a remote sensing–based HNS monitoring technique that can observe a wide area with high resolution. We designed and performed a ground HNS spill experiment using a hyperspectral sensor to detect HNS spill areas and estimate the spill volume. HNS images were obtained by pouring 1 L of toluene into an outdoor marine pool and observing it with a hyperspectral sensor capable of measuring the shortwave infrared channel installed at a height of approximately 12 m. The pure endmember spectra of toluene and seawater were extracted using principal component analysis and N-FINDR, and a Gaussian mixture model was applied to the toluene abundance fraction. Consequently, a toluene spill area of approximately 2.4317 m2 was detected according to the 36% criteria suitable for HNS detection. The HNS thickness estimation was based on a three-layer two-beam interference theory model. Because toluene has a maximum extinction coefficient of 1.3055 mm at a wavelength of 1,678 nm, the closest 1,676.5 nm toluene reflectance image was used for thickness estimation. Considering the detection area and ground resolution, the amount of leaked toluene was estimated to be 0.9336 L. As the amount of toluene used in the actual ground experiment was 1 L, the accuracy of our estimation is approximately 93.36%. Previous studies on HNS monitoring based on remote sensing are lacking in comparison to those on oil spills. This study is expected to contribute to the establishment of maritime HNS spill response strategies in the near future based on the novel hyperspectral HNS experiment.

Characterization of Large Microplastic Debris in Beach Sediments in the Po Delta Area

The use of single-use or disposable plastic objects has massively increased during the last few decades, and plastic has become the main type of litter found in marine environments. The Adriatic Sea is seriously prone to marine litter pollution, and it collects about one-third of all the freshwater flowing into the Mediterranean, mainly via the river Po. This study investigated the type and composition of large microplastic debris collected in different sites in the Po Delta area. Visual classification was performed by relevant criteria, while chemical composition was assessed by infrared spectroscopy. The main plastic fraction is composed of polyolefin (76%), followed by polystyrene (19%). This proportion roughly matches global plastic production, rescaled after excluding plastics with negative buoyancy: all the identified compounds have a specific gravity lower than that of the seawater. Fragments (irregularly shaped debris) represent the most abundant category fraction (85%), followed by pellets, which represent roughly 10% of the total. Overall, the results provided an insight into large microplastic pollution in beach sediments in the Po delta area.

The power of digital PCR in fetal blood group genotyping: a review

: There is a clinical need to determine the fetal blood group status for pregnant women who present with clinically significant red cell antibodies to optimize perinatal care. Non-invasive prenatal testing (NIPT) to assess the fetal blood group status is problematic for blood groups that arise from single nucleotide variants (SNVs) because the cell-free DNA from the maternal allele is present in greater abundance than the fetal allele, resulting in competition, especially in traditional real-time quantitative polymerase chain reaction (qPCR) platforms. This review discusses the power for digital (d)PCR to overcome this limitation. The dPCR is based on first diluting and compartmentalizing individual DNA molecules into individual PCR mixes, so that the competing (e.g., maternal) molecules are separated from the target (fetal) DNA molecule prior to amplification. In comparison to qPCR platforms, dPCR is amenable to the quantitation of a positive signal from an individual DNA molecule, providing the ability to calculate the fractional abundance of the fetal sequence of interest. Comparison studies, though small in number, show that dPCR is more precise and sensitive. Clinical feasibility studies to date show that dPCR for fetal Kell antigen, Rhc, RhE and Duffy antigens have high accuracy. The key limitation of the dPCR approach is that separate assays need to be established and validated for each blood group antigen. Despite that limitation, the power of dPCR for fetal blood group genotyping provides an added diagnostic tool in the management of women with red cell antibodies.

Abstract P6-11-03: Lipid-rich environment induces epigenetic reprogramming in non-transformed breast epithelial cells enhancing a mammary cell plasticity

Abstract Introduction. The identification of women specifically at risk for estrogen receptor negative breast cancer (ER- BC) and the targeted treatment of this disease are significantly unmet clinical needs. We analyzed the gene expression profiles of epithelial cells from the contralateral unaffected breasts (CUBs) of BC patients and identified a lipid metabolism gene signature enriched in the CUBs of women with ER- BC (PMID: 28263391). Subsequently, we observed that exposure of non-transformed breast epithelial cells to lipids results in significant changes in gene expression and histone posttranslational modifications; and increased flux through multiple metabolic reactions, including those of serine and methionine (PMID: 35508495). Interestingly, the upregulated genes are involved in neural development, axon guidance, neural crest pathways and stemness. Neural genes are highly expressed in Triple Negative Breast Cancers (TNBCs) especially in the C2 cluster. Given that mammary stem/progenitor cells have distinct metabolic properties compared to other mammary cell subsets, we hypothesized that upon lipid exposure, stem-like cells have a survival advantage, and that lipid induces epigenetic reprogramming into neural-like cells which may foster a malignant transformation. Methods. To interrogate potential mechanisms linking lipids and epigenetic reprogramming, we performed CUT&RUN for H3K4me3 and H3K27me3 in non-transformed, estrogen and progesterone receptor negative MCF-10A cells cells exposed to vehicle or octanoic acid (OA) for 24 hrs. Peaks were called using MACS2 and differential peaks identified with DiffBind. Differentially expressed genes affected by OA (PMID: 28263391) were compared with target genes from the CUT&RUN. To determine the contribution in OA exposed cells of serine and methionine metabolism to S-adenosyl methionine (SAM), 13C-glucose tracing was performed. The Aldefluour assay was used to identify stem-like (ALDH+) cells in lipid-exposed MCF-10A cells. To determine if lipid-exposed cells adopt a neural-like phenotype, MCF-10A cells were grown on Poly-D-Lysine/Laminin (PDL/LM) coated plates. Results. A total of 661 differential peaks were identified for H3K4me3 (FDR < 0.05) encompassing TNBC C2 markers (NRTN, CHRM3) and genes involved in neuron differentiation, axonogenesis (NGFR, NGF, FOXA2), neural crest migration (NTRK2, MMP2) and EMT (DLL4, MMP15). Approximately 73% of H3K4me3 OA-associated peaks encompass regulatory regions of genes that experienced a significant increase in gene expression with OA exposure (FDR < 0.01), including NGFR (log2 FC = 11.7), FOXA2 (log2 FC = 11.6), NGF (log2 FC = 8). Twelve H3K27me3 peaks were significantly enriched in vehicle (FDR < 0.05) and associated with increased gene expression in OA, among them were the stem cell markers LGR6 (log2 FC = 1.9) and PLAG1 (log2 FC = 2.8). 13C stable isotope tracing revealed that in presence of OA, glucose contributes to increased fractional abundance of the SAM M+1 isotopologue (adj p = 0.003) indicating that carbons derived from the serine synthesis pathway are used for re-methylation of homocysteine to methionine. Vehicle treated cells growing on PDL/LM plates assumed an epithelial phenotype while OA-treated cells adopted a neurite-like phenotype. Upon OA treatment the percentage of ALDH+ cells increased by a minimum of 10%. Conclusions. The increase of fractional abundance of SAM and the upregulation of neural genes regulated by H3K4me3 as well as the enrichment of ALDH+ cells and the development of a neural-like phenotype in a rich lipid environment, suggests that lipid exposure affects the production of SAM, which results in epigenetic fostered plasticity, leading to reprogramming/selecting cells with a multi-potential embryonic or stem-like state and/or differentiation to a neural/neural crest-like state. Citation Format: Mariana Bustamante Eduardo, Gannon Cottone, Seema Khan, Susan Clare. Lipid-rich environment induces epigenetic reprogramming in non-transformed breast epithelial cells enhancing a mammary cell plasticity [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-11-03.

Elucidating the Formation of Ethynylbutatrienylidene (HCCCHCCC; X1A′) in the Taurus Molecular Cloud (TMC-1) via the Gas-phase Reaction of Tricarbon (C3) with the Propargyl Radical (C3H3)

The recent astronomical detection of ethynylbutatrienylidene (HCCCHCCC)—a high-energy isomer of triacetylene (HCCCCCCH) and hexapentaenylidene (H2CCCCCC)—in TMC-1 puzzled the laboratory astrophysics community since proposed reaction pathways could not synthesize the ethynylbutatrienylidene (HCCCHCCC) under cold molecular cloud conditions. Exploiting a retrosynthesis coupled with electronic structure calculations and astrochemical modeling, we reveal that observed fractional abundance of ethynylbutatrienylidene (HCCCHCCC) of 1.3 ± 0.2 × 10−11 can be quantitatively replicated though the barrierless and exoergic reaction of tricarbon (C3) with the resonantly stabilized propargyl radical (C3H3) after a few 105 yr—typical ages of cold molecular clouds. Our study provides persuasive evidence that previously assumed “dead” reactants such as tricarbon (C3) and the propargyl radical (C3H3) provide fundamental molecular building blocks in molecular mass growth processes leading to exotic, high-energy isomers of hydrocarbons: ethynylbutatrienylidene (HCCCHCCC).

Crop Nitrogen Fertilization Schedule in Bread Wheat Affects the Mechanical Performances of Thermoplastic Films Obtained by Plasticization of Flours

Recent research has investigated the plasticization of wheat flour as a non-food alternative application. In this work, we analyzed the performances of thermoplastic films obtained using flours of two bread wheat cultivars (Bologna and Bora) grown in fall–spring under four nitrogen (N) fertilization treatments: (1) continuously well-N-fed (N300 = 300 kg N ha−1, split throughout the growth cycle); (2) N-fed only very early (N60-0 = 60 kg N ha−1, just one month after sowing); (3) N-fed only extremely late (N0-120 = 120 kg N ha−1 at pollination); (4) unfertilized control (N0). Flours were characterized for glutenin and gliadin fractions, Chopin’s alveograph parameters, Field Emission Scanning Electron Microscopy (FESEM) images, and thermogravimetric analysis (TGA), while films were evaluated for mechanical properties (tensile strength at break, σb; elongation at break, εb; Young’s modulus, E) and FESEM images. Differences among treatments for absolute and relative abundances of gluten fractions and alveographic parameters were extremely marked and gave rise to differences in tensile properties of thermoplastic films. Within each cultivar, the ranking of treatments for εb values was N0 > N60-0 > N0-120 > N300. Thus, εb was inversely correlated with crop N availability and total gluten content of the flour. The σb was less variable among N treatments; however, in both cultivars, it was high in N0 and N300 and appreciably lower in N0-120. Overall, the best mechanical performances were obtained with flours from crops not subjected to imbalances in N nutrition (N0, N300). Our work demonstrates that bioplastic engineering needs to take into consideration the variability of biological source material like that caused by different crop N availability.

Bajocian–Bathonian dinoflagellate cyst assemblages from the Middle Atlas, Morocco: Palynostratigraphic and paleoenvironmental implications

The Bajocian–Bathonian transition has been identified for the first time in the Skoura syncline of the folded Middle Atlas of Morocco based on dinoflagellate cyst and palynofacies analysis of the Ich Timellaline/Bou Akrabene Formation carbonates. This palynological study involved 109 samples of marls and limestones whose organic content yielded diverse and well-preserved dinoflagellate cyst assemblages comprising 68 taxa including stratigraphic marker taxa. Two association biozones have been defined for the late Bajocian–early Bathonian interval. The Cribroperidinium crispum-Ctenidodinium cornigerum (CC/CC) biozone is defined between the base of the Recifa Formation (Upper Bajocian) and the Ich-Timellaline / Bou Akrabene Formation (Upper Bajocian–Lower Bathonian). The second association biozone of Ctenidodinium combazii and Dichadogonyaulax sellwoodii (CC/DS) corresponds to the upper interval of the FD section (top of the Ich-Timellaline / Bou Akrabene Formation and the base of the El Mers I Formation). These two biozones were correlated with the late Bajocian–early Bathonian biozones defined in the Sub-Boreal (northwest Europe), Tethyan, and Australian domains. Close similarity between the Moroccan Middle Atlas, the Tethyan, and the Sub-Boreal domain associations has been noted. Quantitative analysis of organic matter constituents has allowed the paleoenvironmental reconstruction of the late Bajocian–early Bathonian. The organic residues of the studied samples recorded an increased land-derived phytoclasts dominance compared to amorphous organic matter and palynomorphs, indicating a proximal oxic shelf depositional environment with high terrestrial and freshwater influx during the late Bajocian–early Bathonian. During the Late Bajocian, the depositional environment corresponds to a proximal continental shelf with fluctuations from a distal to a marginal/stagnant environment.Below the Upper Bajocian–Lower Bathonian boundary, a significant marine incursion, or rather a transgression, is recorded in the studied sediments attested by an important marine fraction and dinoflagellate cysts abundance, which probably corresponds to the last Bajocian Maximum flooding surface (MFS).During the early Bathonian, the depositional environment evolved towards a distal continental shelf with an increasing marine fraction including dinoflagellate cysts and high species diversity. This may be related to the rising sea level which corresponds to the first Bathonian eustatic elevation. The proximal /marginal conditions are restored at the uppermost part of the section.

Gas phase Elemental abundances in Molecular cloudS (GEMS)

Context.Gas phase Elemental abundances in molecular CloudS (GEMS) is an IRAM 30-m Large Program aimed at determining the elemental abundances of carbon (C), oxygen (O), nitrogen (N), and sulfur (S) in a selected set of prototypical star-forming filaments. In particular, the elemental abundance of S remains uncertain by several orders of magnitude, and its determination is one of the most challenging goals of this program.Aims.This paper aims to constrain the sulfur elemental abundance in Taurus, Perseus, and Orion A based on the GEMS molecular database. The selected regions are prototypes of low-mass, intermediate-mass, and high-mass star-forming regions, respectively, providing useful templates for the study of interstellar chemistry.Methods.We have carried out an extensive chemical modeling of the fractional abundances of CO, HCO+, HCN, HNC, CS, SO, H2S, OCS, and HCS+to determine the sulfur depletion toward the 244 positions in the GEMS database. These positions sample visual extinctions fromAV~ 3 mag to >50 mag, molecular hydrogen densities ranging from a few × 103cm−3to 3 × 106cm−3, andTk~ 10–35 K. We investigate the possible relationship between sulfur depletion and the grain charge distribution in different environments.Results.Most of the positions in Taurus and Perseus are best fitted assuming early-time chemistry,t= 0.1 Myr, ζH2~ (0.5−1) × 10−16s−1, and [S/H] ~ 1.5 × 10−6. On the contrary, most of the positions in Orion are fitted witht= 1 Myr and ζH2~ 10−17s−1. Moreover, ~40% of the positions in Orion are best fitted assuming the undepleted sulfur abundance, [S/H] ~ 1.5 × 10−5. We find a tentative trend of sulfur depletion increasing with density.Conclusions.Our results suggest that sulfur depletion depends on the environment. While the abundances of sulfur-bearing species are consistent with undepleted sulfur in Orion, a depletion factor of ~20 is required to explain those observed in Taurus and Perseus. We propose that differences in the grain charge distribution might explain these variations. Grains become negatively charged at a visual extinction ofAV~ 3.5 mag in Taurus and Perseus. At this low visual extinction, the S+abundance is high,X(S+) > 10−6, and the electrostatic attraction between S+and negatively charged grains could contribute to enhance sulfur depletion. In Orion, the net charge of grains remains approximately zero until higher visual extinctions (AV~ 5.5 mag), where the abundance of S+is already low because of the higher densities, thus reducing sulfur accretion. The shocks associated with past and ongoing star formation could also contribute to enhance [S/H].

Effect of reactant ratio and nanofillers type on the microstructural properties, porosity fluctuations and heavy metal removal ability of chitosan-clay hybrid materials

The structure, porosity, and functionality of synthesized chitosan-clay nanocomposites (NCs) are examined throughout this work in relation to the initial stoichiometry and octahedral cavity occupation of the clay fraction. Dioctahedral and trioctahedral smectite are selected as starting materials. X-Ray Diffraction analysis (XRD) confirms the accomplishment of the NCs synthesis process. The stoichiometry fluctuation implies a crystallite exfoliation process provided that the clay fraction contribution must not reach twice the organic ones. From 1:3 stoichiometry ratio, The intercalation process is enhanced by the interlamellar space (IS) closures, and crystallite size increases with crystallinity degree. According to transmission electron microscopy-energy dispersive X-ray (TEM-EDX) investigations, the exfoliation of "clay-particles" wrapping the organic fraction and the intercalation process occurred as the clay fraction abundance increased. Despite the low proportion approved from the synthesis beginning process, Fourier transform infrared spectroscopy (FTIR) reveals the polymer fraction characteristics absorption bands. The Brunauer, Emmett and Teller (BET) analysis of specific surface area and Barrett-Joyner-Halenda (BJH) Analysis of pore size distribution (PSD) supports the findings from TEM/EDX. For slightly saturated soil solution with Pb2+ or Cd2+ cation, Atomic absorption spectroscopy (AAS) evaluate the NCs adsorption capacity. The outcomes are extremely positive for dioctahedral smectite.

SISLU-Net: Spatial Information-Assisted Spectral Information Learning Unmixing Network for Hyperspectral Images

Spectral unmixing is among one of the major hyperspectral image analysis tasks that aims to extract basic features (endmembers) at the subpixel level and estimate their corresponding proportions (fractional abundances). Recently, the rapid development of deep learning networks has provided us with a new method to solve the problem of spectral unmixing. In this paper, we propose a spatial-information-assisted spectral information learning unmixing network (SISLU-Net) for hyperspectral images. The SISLU-Net consists of two branches. The upper branch focuses on the extraction of spectral information. The input of the upper branch is a number of pixels randomly extracted from the hyperspectral image. The data are fed into the network as a random combination of different pixel blocks each time. The random combination of batches can boost the network to learn global spectral information. Another branch focuses on learning spatial information from the entire hyperspectral image and transmitting it to the upper branch through the shared weight strategy. This allows the network to take into account the spectral information and spatial information of HSI at the same time. In addition, according to the distribution characteristics of endmembers, we employ Wing loss to solve the problem of uneven distributions of endmembers. Experimental results on one synthetic and three real hyperspectral data sets show that SISLU-Net is effective and competitive compared with several state-of-the-art unmixing algorithms in terms of the spectral angle distance (SAD) of the endmembers and the root mean square error (RMSE) of the abundances.

The starting stoichiometry, keys parameter to enhance the intrinsic microstructural and functional properties of synthesized hybrid nanocomposites chitosan/Na-montmorillonite/ZnO nanoparticlest type

To improve the intrinsic qualities of hybrid nanocomposite (NC), polymer, clay, and metallic oxide are combined. This study investigates the effects of starting stoichiometry variation on the microstructural and functional properties of synthesized hybrid NC composed of chitosan (CTS), Na-montmorillonite (MMT), and ZnO nanoparticles (NPs). To carry out the synthesized process, a solution blending approach is used. A correlation of the outcomes from the several analyses methods such as X-ray diffraction (XRD), Fourier Transform InfraRed spectroscopy (FTIR), Transmission Electron Microscopy (TEM), Impedance spectroscopy (IS), and UV–VIS spectrophotometry ensures the accuracy of the analysis. Regardless of the initial stoichiometry rate, the microstructural analysis shows that NC can be successfully synthesized. The growth and changes in the intensity and sharpness of the characteristic reflections shown by the semiquantitative XRD analysis suggest that the synthesis process was certainly successful. The apparent structure aberration, caused by the stoichiometry fluctuation, is manifested as an XRD reflection position shift and varied intensity strength.The intercalation process and the exfoliation of "clay-particles" enclosing the organic fraction, according to TEM/EDX experiments, occurred as the clayey fraction's abundance surged. Despite the variable ratio approved at the start of the synthesis process, FTIR spectroscopy displays the polymer fraction's characteristic absorption bands. Synthesized NC has significant UV blocking properties while retaining good transparency in the visible range. This behavior may have its roots throughout the fact that the CS surface modification has induced the bandgap energy fluctuation of ZnO NPs. The photocatalytic activity of the produced NC is evaluated using MB degradation measurements. The outcomes are extremely positive for the sample with a starting stoichiometry almost equally distributed between CTS and ZnO (NPs). Results from the IS, for the selected sample, shows that synthesized NC exhibits semiconductor behavior,and as a dielectric material, the sample is dispersive with a power loss over a specific frequency range.

Xanthones from Gentianella acuta (Michx.) Hulten Ameliorate Colorectal Carcinoma via the PI3K/Akt/mTOR Signaling Pathway.

Colorectal carcinoma (CRC) is a kind of malignant tumor closely related to ulcerative colitis. Xanthone derivatives are one of the most promising therapeutic drugs which have been used in phase I/II clinical trials for cancer therapy. Our previous study indicated that the aerial parts of Gentianella acuta Michx. Hulten (GA) was rich in xanthones and showed a good therapeutic effect on ulcerative colitis in mice, suggesting that GA xanthones might have some therapeutic or ameliorative effects on CRC. However, no relevant study has been reported. This study aims to find the effective substances of GA inhibiting CRC and clarify their mechanism. Solvent extraction, column chromatographic separation, and LC-MS analysis were used to characterize the 70% EtOH extract of GA and track xanthones abundant fraction XF. MTT assay was carried out to clarify the activity of GA fractions; the result showed XF to be the main active fraction. LC-MS analysis was executed to characterize XF, 38 xanthones were identified. Network pharmacology prediction, in vitro activity screening, and molecular docking assay were combined to predict the potential mechanism; the PI3K/Akt/mTOR signaling pathway was found to be most important. Western blot assay on the main active xanthones 1,3,5-trihydroxyxanthone (16), 1,3,5,8-tetrahydroxyxanthone (17), 1,5,8-trihydroxy-3-methoxyxanthone (18), and 1,7-dihydroxy-3,8-dimethoxyxanthone (19) was used to verify the above prediction; these xanthones were found to inhibit the PI3K/Akt/mTOR signaling pathway, and 17 played a significant role among them through Western blot assay using PI3K/AKT/mTOR agonist IGF-1. In conclusion, this study demonstrated that GA xanthones were effective compounds of GA inhibiting CRC by regulating PI3K/Akt/mTOR signaling pathway transduction, at least. Importantly, 1,3,5,8-tetrahydroxyxanthone (17), the most abundant active xanthone in GA, might be a candidate drug for CRC.

Petrological and chemical characterizations of pristine and reworked phosphorites from Negev, Israel: Insights into industrial usage

Phosphorites are an essential natural resource for producing phosphoric acid, phosphate fertilizers, and phosphate-based products. Detailed characterization and an appropriate assortment of phosphate resources are necessary to identify rocks that are chemically suitable for the phosphate industry. In the present study, we investigated the chemical composition and petrographic characteristics of phosphorites from three phosphate fields located in the same syncline, Zin Negev, Israel. At each site, the succession of pristine and reworked phosphorite layers along 10 m of the section was observed. Based on the chemical and petrographic analysis of phosphorites, it can be concluded that even though all the studied phosphorites were deposited in the same basin under suboxic conditions, the sedimentary settings are varied at each site. These variations resulted in differences in sedimentary structures and chemical composition, including the concentrations of major and trace elements and the abundance of the organic matter fractions. In all studied samples, a decrease in total organic carbon and redox-sensitive trace elements was observed upon the transition from a pristine to a reworked phosphorite phase, while the relative abundance of organic matter fractions remained nearly constant. The results of the present study indicate that, in addition to high-quality phosphorites at anticlinal heights, phosphorites with low organic matter contents in synclines can also be suitable for industrial applications. However, in phosphates, where humic substances represent the main fraction of OM that is located inside carbonate-fluorapatite grains, difficulties in the separation of OM from carbonate-fluorapatite grains during the production process cannot be excluded.

Protein Biocargo and Anti-Inflammatory Effect of Tomato Fruit-Derived Nanovesicles Separated by Density Gradient Ultracentrifugation and Loaded with Curcumin

Plant-derived nanovesicles (PDNVs) have become attractive alternatives to mammalian cell-derived extracellular vesicles (EVs) both as therapeutic approaches and drug-delivery vehicles. In this study, we isolated tomato fruit-derived NVs and separated them by the iodixanol density gradient ultracentrifugation (DGUC) into twelve fractions. Three visible bands were observed at densities 1.064 ± 0.007 g/mL, 1.103 ± 0.006 g/mL and 1.122 ± 0.012 g/mL. Crude tomato PDNVs and DGUC fractions were characterized by particle size-distribution, concentration, lipid and protein contents as well as protein composition using mass spectrometry-based proteomics. Cytotoxicity and anti-inflammatory activity of the DGUC fractions associated to these bands were assessed in the lipopolysaccharide (LPS)-stimulated human monocytic THP-1 cell culture. The middle and the low-density visible DGUC fractions of tomato PDNVs showed a significant reduction in LPS-induced inflammatory IL-1β cytokine mRNA production. Functional analysis of proteins identified in these fractions reveals the presence of 14-3-3 proteins, endoplasmic reticulum luminal binding proteins and GTP binding proteins associated to gene ontology (GO) term GO:0050794 and the regulation of several cellular processes including inflammation. The most abundant middle-density DGUC fraction was loaded with curcumin using direct loading, sonication and extrusion methods and anti-inflammatory activity was compared. The highest entrapment efficiency and drug loading capacity was obtained by direct loading. Curcumin loaded by sonication increased the basal anti-inflammatory activity of tomato PDNVs.

Land use impact on the levels of fluorescent dissolved organic matter, phytoplankton and zooplankton in urban lakes

Urban lakes are vulnerable ecosystems, sensitive to environmental challenges, such as pollution, land use transformation and climate change. Closed and open lakes play relatively different roles in the accumulation, transport and transformation of pollutants and organic matter. Land use can influence the concentration of dissolved organic matter and the abundance of phytoplankton. Little is known about the relationship between fluorescent dissolved organic matter (FDOM), phytoplankton and zooplankton in open and closed lakes, relative to the impact of land use. This study aims to determine the connection between various types of land use and FDOM characteristics, as well as phytoplankton and zooplankton abundances in urban lakes. For the closed lakes samples, results showed positive associations between Bacillariophyceae and Testacea, and the protein-like fraction, while for open lakes, positive associations were found between these groups and the microbial humic-like fraction. Also, copepods and rotifers were associated with the humic-like fraction, in closed lakes, but in open lakes copepods correlated with the biological index, and rotifers with the humification index and fluorescence T/C ratio. Results suggested that discontinuous urban fabric, dump sites and abandoned lands decreased the abundance of protein-like fraction and phytoplankton. However, lakes with the highest quantity of protein-like FDOM also had the highest coverage of continuous urban fabric around the lake. Green urban areas decreased the quantity of humic-like FDOM. No impact by land use type was observed on zooplankton groups, suggesting that zooplankton may be less vulnerable to land use. Our findings will contribute to an improved urban water management and to an effective control of FDOM and phytoplankton abundances in urban lakes.

Development of a novel sea surface temperature proxy based on bacterial 3-hydroxy fatty acids

Gram-negative bacterial 3-hydroxy fatty acids (3-OH-FAs) have received recent attention for their potential as palaeoclimate proxies. A novel temperature proxy, the ratio of anteiso to normal C13 3-OH-FA (RAN13), has been proposed for sea surface temperature (SST) reconstruction in the North Pacific Ocean. However, whether this newly proposed temperature proxy is applicable to marginal seas with significant terrigenous input or tropical oligotrophic seas requires further investigation. Here, we analyzed the composition and distribution of 3-OH-FAs and evaluated the possible impact of various environmental parameters (SST, water depth, dissolved oxygen, salinity and nutrient concentration) on their distribution in marine surface sediments from the Bohai Sea (BS) and the South China Sea (SCS). In the BS, the potential source proxy, fractional abundance of anteiso 3-OH-FAs (average 17%), indicates 3-OH-FA geochemical signature are not greatly overprinted by terrigenous inputs. The relative abundance of long-chain 3-OH-FAs (C15-C18) are higher in the SCS (average 41%) compared to those in other seas (average 33% for all marine samples). Massive inputs of terrigenous organic matter to the BS likely result in overestimation of SSTs based on the RAN13 proxy, and limited abundance of anteiso and normal C13 3-OH-FAs in the oligotrophic SCS may increase the uncertainty of the RAN13 estimated SSTs. More importantly, we find that most short-chain 3-OH-FAs are temperature dependent, especially the fractional abundance of i-C12, a-C13, i-C14 and n-C14 with a high determination coefficient (R2 > 0.60). Based on these newly found correlations, we propose a novel proxy: RANs. The RANs index shows a strong linear relationship with SST (R2 = 0.92, p< 0.001, n = 85) and more accurate prediction than the RAN13, especially in tropical samples. Furthermore, the RANs proxy is significantly correlated with TEX86, and RANs-based SSTs are approximate to LDI derived temperature in the SCS, which support the reliability of RANs as a temperature proxy. These findings further suggest 3-OH-FA based proxies have potential for paleo-SST reconstruction, especially at higher and lower ends of the ocean temperature spectrum and even in cases where marginal inputs of terrestrial organic matter and nutrients are high.

High-throughput sequencing and marker pigment analysis of freshwater phytoplankton: A direct comparison with microscopic count data in the tropical crater lakes of Western Uganda

High-throughput DNA sequencing (HTS) and photosynthetic marker-pigment analysis can provide cost-and time-efficient alternatives for morphology-based microscopic identification and counting of lacustrine phytoplankton. However, application of particularly HTS in tropical lakes is still uncommon. We analyzed the community composition of cyanobacterial and eukaryotic phytoplankton in relation to trophic status and other environmental factors in 15 tropical crater lakes in western Uganda, using both high-performance liquid chromatography (HPLC) of photosynthetic marker pigments and HTS of 16 S and 18 S small subunit rRNA genes. We then compared the results with phytoplankton composition data based on microscopic identification and cell counting to evaluate whether the two former methods can be alternative or complementary approaches to analyze these lakes’ phytoplankton communities. HTS recorded 105 operational taxonomic units (OTUs) of cyanobacteria, and 197 OTUs of autotrophic eukaryotes mainly from dinoflagellates, cryptophytes and green algae. Ochrophyta (chrysophytes and diatoms) were present in low abundances only, and the few remaining sequences belonged to Streptophyta and Haptophyta. Marker pigment distribution among samples reflected the widespread and often dominant presence of cyanobacteria (primarily zeaxanthin, myxoxanthophyll and echinenone), followed by green algae (chlorophyll b, lutein, antheraxanthin, neoxanthin) and diatoms (fucoxanthin, diato-diadinoxanthin), and with cryptophyta (alloxanthin) important in some of the lakes. Direct and indirect ordinations of the OTUs and marker pigments revealed that, similar to patterns observed in cell counts, phytoplankton community composition differed between deep oligotrophic lakes and shallower more productive lakes, even though the distribution of cyanobacterial OTUs was more related to lake water conductivity and season than to trophic status. Procrustes analyses of the composition of green algae and Ochrophyta, the two dominant eukaryotic groups, based on HTS data showed patterns significantly similar to composition data based on cell counts, but no significant correlations were found between the complete eukaryotic or cyanobacterial HTS data and cell count data. While the latter discrepancies can be attributed to method-related biases in both HTS and microscopy, in contrast to the microscopic approach HTS failed to identify trophic indicator species and did not assign all lakes to the correct trophic category. Composition data based on marker pigments clustered the 15 lakes according to their trophic level only when pigment abundances were expressed as absolute concentrations, not when expressed as fractional abundances. We attribute this lower discriminating power partly to the wide distribution of cyanobacteria in these tropical crater lakes, besides the pigments’ low taxonomic resolution. Nevertheless, as the compositional patterns in relation to environmental variation observed in marker pigments and OTUs of the dominant eukaryotic phytoplankton groups are similar to those in cell count data, both methods hold potential for ecosystem-level monitoring of tropical crater lakes. However, the high-resolution HTS approach is handicapped by non-uniform amplification of gene sequences, while the low-resolution marker-pigment approach is handicapped by the widespread dominance of cyanobacteria in these systems irrespective of their trophic status.