The presence and impacts of plastic marine debris (PMD) have been documented in the oceans worldwide, and they deserve special attention. This study is the first to report the presence of ...microplastics in tourist beaches located in Huatulco Bay, southern Mexico. A total of 70 beach sediment samples (for 2 distinct seasons) were collected from Huatulco Bay in April 2013 and December 2014. The samples were subsequently extracted by scanning electron microscopy (SEM) to identify the fibrous microplastics (diameter<5mm). The maximum number of fibrous materials was found in April 2013 and December 2014 in the Rincón Sabroso beach (48/30g sediment) and the Cuatunalco beach (69/30g sediment), respectively. Overall, a high amount of microplastics is present in the Conejos, Tangolunda, Santa Cruz, and San Agustin beaches. The microplastics are mainly derived from tourism-based activities and effluents discharged from the hotels and restaurants located along the beaches.
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•Microplastics were found in the coastal sediments, Pacific coast, Mexico.•Use of plastic materials by tourists and local municipal effluents•High density of microplastics reported based on density of tourist presence.•Risk to the food web structure and the health hazard for humans
Glycosylation of metabolites serves multiple purposes. Adding sugars makes metabolites more water soluble and improves their biodistribution, stability, and detoxification. In plants, the increase in ...melting points enables storing otherwise volatile compounds that are released by hydrolysis when needed. Classically, glycosylated metabolites were identified by mass spectrometry (MS/MS) using M-sugar neutral losses. Herein, we studied 71 pairs of glycosides with their respective aglycones, including hexose, pentose, and glucuronide moieties. Using liquid chromatography (LC) coupled to electrospray ionization high-resolution mass spectrometry, we detected the classic M-sugar product ions for only 68% of glycosides. Instead, we found that most aglycone MS/MS product ions were conserved in the MS/MS spectra of their corresponding glycosides, even when no M-sugar neutral losses were observed. We added pentose and hexose units to the precursor masses of an MS/MS library of 3057 aglycones to enable rapid identification of glycosylated natural products with standard MS/MS search algorithms. When searching unknown compounds in untargeted LC-MS/MS metabolomics data of chocolate and tea, we structurally annotated 108 novel glycosides in standard MS-DIAL data processing. We uploaded this new in silico-glycosylated product MS/MS library to GitHub to enable users to detect natural product glycosides without authentic chemical standards.
In the context of in situ groundwater remediation, mixing is vital for a successful outcome. A slow mixing rate between the contaminated groundwater and the injected treatment solution can severely ...weaken the effective degradation rate. Engineered Injection‐Extraction (EIE) has been proposed as a means to accelerate dilution within the porous medium. However, existing studies on the subject have not considered the potential impact of connectivity and preferential flow‐paths. Neglecting connectivity can lead to an overestimation of EIE's capabilities, since the fluid may in reality be carried mainly through a few high‐permeability channels, thus hampering mixing and reaction. Due to the fact that channeling can be found in many actual sites, in this work we aim to evaluate EIE methods in both poorly connected (represented as Multigaussian fields) and well‐connected fields (represented as non‐Multigaussians). The approach is to identify, for each given medium, a stirring protocol—defined by a specific combination of rotation angle and rotation rate—which maximizes mixing. To that end, metrics are proposed in order to (a) quantify both the mixing and the containment of the treatment solution within a given remediation volume, and (b) characterize the particle trajectories to explicitly evaluate if preferential paths are broken. The results obtained from these metrics are quite similar for both types of fields, proving that the enhancing of mixing by means of EIE is effective regardless of the presence of preferential flow paths. This study demonstrates that EIE via rotating dipoles diminishes the remediation outcome uncertainty induced by medium heterogeneity.
Key Points
The spreading and dilution of a treatment solution is tested under rotating‐dipole Engineered Injection‐Extraction (EIE)
EIE is similarly effective in both Multigaussian log‐conductivity fields and well‐connected non‐Multigaussian fields
EIE reduces the remediation outcome uncertainty associated to porous medium heterogeneity and connectivity
The inclusion of monoclonal antibodies targeting immune checkpoints such PD-1/PD-L1 or CTLA-4 has revolutionized the landscape of anti-cancer therapy. However, PD-1 and CTLA-4 blockade failed to ...achieve clinical benefit in CLL, thus attention has been focused on emerging checkpoints in this malignancy. LAG-3 is an immune checkpoint receptor that negatively regulates T cell-mediated responses by inducing an hyporesponsive state, thus promoting tumor escape. Patients with chronic lymphocytic leukemia (CLL) develop a profound immune suppression that leads to lessened immunosurveillance and increased risk of developing a secondary neoplasia. In the study herein, we report the profound dysregulation of LAG-3 on leukemic cells in CLL. Likewise, natural killer (NK) and T cells showed increased LAG-3 expression, hence suggesting a role for this checkpoint in CLL-associated immunosuppression. High LAG-3 expression, as well as high levels of soluble LAG-3 (sLAG-3), correlated with adverse cytogenetics and poor outcome in patients with CLL, highlighting the clinical relevance of this immune checkpoint. Treatment of peripheral blood mononuclear cells (PBMCs) from patients with CLL with relatlimab, a new anti-LAG-3 blocking antibody currently evaluated in numerous clinical trials, depleted leukemic cells and restored NK cell- and T cell-mediated responses. Moreover, combination of LAG-3 with the immunomodulatory drug (IMiD) lenalidomide significantly increased IL-2 production by T cells and antibody-dependent cytotoxicity (ADCC) mediated by NK cells. Altogether, these data provide new insights into the potential anti-leukemic effects of relatlimab, currently in clinical trials in CLL, and provides the rationale to further investigate its combination with IMiDs for the management of hematological malignancies.
The INFOGEST standardized method was applied to assess the potential bioaccessibility and bioaccessibility of the phenolic compounds from a Galician extra-virgin olive oil (EVOO). The in vitro ...digestion model involves three steps and generates two fractions after each one: an aqueous fraction (namely, water phase (Wp)) and an oily fraction (namely, oily phase (Op)). The results showed that secoiridoids were the most abundant family in the Galician EVOO polar fraction, representing 98% of the total phenolic compounds. After oral digestion, phenolic acids and simple phenols were mainly detected in Wp, while lignans and flavonoids were mostly found in Op. After gastric digestion, extensive hydrolysis of secoiridoids was observed to generate free tyrosol, hydroxytyrosol, and hydroxytyrosol acetate. The instability of secoiridoids after intestinal digestion was again responsible for the release of simple phenols, which were mainly recovered in Wp together with flavonoids. In contrast, lignans were stable to duodenal conditions and remained in Op.
Incorporating carbon nanoparticles (CNPs) into polymers can enhance their mechanical behavior; however, enhancement depends strongly on compatibility and homogeneous dispersion. Actual methods to ...succeed high dispersion and compatibility are complicated, have solvent‐associated problems, and long processing times. The present work proposes the increase of the dispersion and compatibility of CNPs in a polypropylene (PP) matrix to obtain a nanocomposite with high mechanical properties, using simple, fast, and green methodologies: the modification of the CNPs by cold propylene plasma and the synergistic effect resulting from mixtures of carbon nanofibers (CNFs) and graphene nanoplatelets (GNPs) with PP matrix by melt mixing. Mixtures of CNFs and GNPs in 9:1, 8:2, and 7:3 ratios at 1 and 5 wt/wt% with and without surface modification by cold propylene plasma were fabricated. The compatibility and dispersion of the CNPs in the PP matrix were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy, and the results were related to the mechanical properties. The results show that the use of mixtures improved the dispersion in the system and hindered the reagglomeration of CNPs, whereas surface modification with plasma promotes higher compatibility between the phases. The elastic modulus of PP reached an increase of 127.40% using a modified mixture by plasma in a 7:3 ratio (CNF:GNPs) at 5 wt/wt%, while when the CNPs were used individually, the modified CNFs and GNPs at 5 wt/wt%, reached 97.77% and 111.85%, respectively. In addition, a finite element analysis shows that the stresses in nanocomposites fabricated with mixtures of CNPs are supported to a greater extent by GNPs than CNFs due to their morphology with a low number of graphene sheets, which allows them to have greater flexibility.
Influence of methods for promoting dispersion and compatibility: melt mixing, cold plasma modification, and mixtures of carbon nanoparticles of different geometries on enhancing the elastic modulus of polypropylene nanocomposites with carbon nanofibers and graphene nanoplatelets.
Broad absorption lines (BALs) in quasar spectra identify high-velocity outflows that likely exist in all quasars and could play a major role in feedback to galaxy evolution. The variability of BALs ...can help us understand the structure, evolution and basic physical properties of the outflows. Here we report on our first results from an ongoing BAL monitoring campaign of a sample of 24 luminous quasars at redshifts 1.2 < z < 2.9, focusing on C ivλ1549 BAL variability in two different time intervals: 4-9 months (short term) and 3.8-7.7 yr (long term) in the quasar rest frame. We find that 39 per cent (7/18) of the quasars varied in the short-term data, whereas 65 per cent (15/23) varied in the long-term data, with a larger typical change in strength in the long-term data. The variability occurs typically in only portions of the BAL troughs. The components at higher outflow velocities are more likely to vary than those at lower velocities, and weaker BALs are more likely to vary than stronger BALs. The fractional change in BAL strength correlates inversely with the strength of the BAL feature, but does not correlate with the outflow velocity. Both the short-term and long-term data indicate the same trends. The observed behaviour is most readily understood as a result of the movement of clouds across the continuum source. If the crossing speeds do not exceed the local Keplerian velocity, then the observed short-term variations imply that the absorbers are <6 pc from the central quasar.
ABSTRACT
We present a detailed analysis of HARPS-N radial velocity observations of K2-100, a young and active star in the Praesepe cluster, which hosts a transiting planet with a period of 1.7 d. We ...model the activity-induced radial velocity variations of the host star with a multidimensional Gaussian Process framework and detect a planetary signal of 10.6 ± 3.0 ${\rm m\, s^{-1}}$, which matches the transit ephemeris, and translates to a planet mass of 21.8 ± 6.2 M⊕. We perform a suite of validation tests to confirm that our detected signal is genuine. This is the first mass measurement for a transiting planet in a young open cluster. The relatively low density of the planet, $2.04 _{ - 0.61 } ^ { + 0.66 }$ ${\rm g\, cm^{-3}}$, implies that K2-100b retains a significant volatile envelope. We estimate that the planet is losing its atmosphere at a rate of $10^{11}\!-\!10^{12}\, {\rm g\, s^{-1}}$ due to the high level of radiation it receives from its host star.
Baseline data on concentration, fractionation, pollution level and ecological risk index for seventeen beach sediments from Santa Rosalia mining region of Baja California Sur, Mexico were assessed. ...Higher concentrations of Rare Earth Elements (REEs) (mean. 341.49 μg/g) indicated that it is higher than most of the mining regions around the world. Normalization pattern showed enrichment of Eu (>4) and calculated geochemical indices revealed that light and middle REEs are moderately polluted with most of the sampling points located closer to the river discharge. Potential Ecological Risk Index (PERI) showed that Eu (20.2), Tb (20.88), and Lu (28.57) pose moderate ecological risk to the soil at selected stations (10, 11, 15 and 16) with a risk index value ranging from 245 to 359. Pearson's correlation matrix suggested that all REEs are highly correlated (r2 0.95) with each other having similar geochemical characteristics and indicating identical source due to continuous mining activity.
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•REE concentration in sediments is 3 to 15-fold higher than similar mining areas.•Geochemical indices EFs, Igeo, CF, CD, PLI indicate HREEs are more polluted.•Eu, Tb, and Lu present moderate ecological risk to the environment.
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