This work describes the first multiple spiking isotope dilution procedure for organic compounds using 13C labeling. A double-spiking isotope dilution method capable of correcting and quantifying the ...creatine–creatinine interconversion occurring during the analytical determination of both compounds in human serum is presented. The determination of serum creatinine may be affected by the interconversion between creatine and creatinine during sample preparation or by inefficient chemical separation of those compounds by solid phase extraction (SPE). The methodology is based on the use differently labeled 13C analogues (13C1-creatinine and 13C2-creatine), the measurement of the isotopic distribution of creatine and creatinine by liquid chromatography–tandem mass spectrometry (LC-MS/MS) and the application of multiple linear regression. Five different lyophilized serum-based controls and two certified human serum reference materials (ERM-DA252a and ERM-DA253a) were analyzed to evaluate the accuracy and precision of the proposed double-spike LC-MS/MS method. The methodology was applied to study the creatine–creatinine interconversion during LC-MS/MS and gas chromatography–mass spectrometry (GC-MS) analyses and the separation efficiency of the SPE step required in the traditional gas chromatography–isotope dilution mass spectrometry (GC-IDMS) reference methods employed for the determination of serum creatinine. The analysis of real serum samples by GC-MS showed that creatine–creatinine separation by SPE can be a nonquantitative step that may induce creatinine overestimations up to 28% in samples containing high amounts of creatine. Also, a detectable conversion of creatine into creatinine was observed during sample preparation for LC-MS/MS. The developed double-spike LC-MS/MS improves the current state of the art for the determination of creatinine in human serum by isotope dilution mass spectrometry (IDMS), because corrections are made for all the possible errors derived from the sample preparation step.
Samples of PM10 and PM2.5 were collected using High Vol and MiniVol devices on the platform of a subway station in Mexico City and in an outdoor location close to it, using such devices. Soluble ...extractable organic matter (SEOM) and water solubility of metals were determined. Elemental composition and solubility of trace metals were determined and individual aerosol particles were studied with scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX). The concentration levels in both sizes were similar during all days with the exception of weekends, especially on Sunday when activity decreases due to lower trains’ frequency. The largest particles concentrations in the subway were found from 06:00 to 14:00 and the lowest concentrations were registered from 22:00 to 06:00. Concentrations of PM2.5 ranging between 60 μg m−3 and 93 μg m−3 (10% and 90% percentile) in the subway were 6% larger than outside, whereas PM10 were 20% larger than outside ranging from 88 μg m−3 to 145 μg m−3. Greater Fe, Cu, Ni, Cr and Mn concentrations were quantified in the subway samples as compared to the airborne particles by up to 2.5, 9, 1.8, 2.0 and 2.6 times, respectively. Even when the solubility percent of these metals in the subway PM was smaller than in the outdoor airborne particles, metals’ concentrations were greater. SEM and EDS exhibit the presence of many individual particles with a large metal content in the subway samples. Correlation analysis showed the influence of outdoor PM in the subway aerosols, but characterization revealed also important differences in the presence of metals and SEOM, due to underground sources such as friction, brake system, and metals from sparking. This means that a large number of commuters are exposed during labor days to large toxic metals concentrations as they transit.
► First attempt to study in depth the air quality in the underground system in Mexico. ► Elemental speciation was done to assess the underground’s microenvironment. ► This is a comparative study broaching several world underground systems. ► Water solubility of the metals incorporated into the PM particles was determined. ► SEM micrographs and EDX analysis revealed important aspects of morphology.
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•PM2.5 concentrations at station platforms are 2–5 times greater than outdoors.•The greater the depth, the greater the PM2.5 concentrations, as well as species.•Iron, Mn, Cr and other ...metals come from wheel/rail mechanical abrasion.•Most abundant metals in subway aerosols are Fe >>Cu > Zn > Mn > Pb > Cr > V>Ni.•Bioavailability using ALF was Zn > Pb > V > Ni > Cu > Mn > Cr in subway PM2.5.
PM2.5 that have been related to public health risks, were collected during two seasons with High-Vol samplers in platforms of a Mexican subway station, which interconnects through transfers three lines having different depths. The objective was to study the influence of depth on the PM2.5 concentrations and their species. PM2.5 concentrations in cold-dry and warm-dry seasons presented statistical differences, being in average 57 and 66 μgm−3 respectively, in the shallower line 9; 90 μgm−3 and 111 μgm−3 in line 1; and 104 and 122 μgm−3in the deepest line 7. During the cold-dry season and warm-dry season PM2.5concentrations in the subway environment were respectively up to 3.5 times and up to 5 times greater than in the ambient air. Like PM2.5, metals analyzed with an OES-ICP presented higher concentrations in deeper lines as well as PAHs quantified with CG-MS, which ranged from 4.5 to 11.7 ngm−3. High PM2.5, metals and organic toxic concentrations found in deeper lines of the subway environment represent a risk for commuters endorsing the need for ventilation systems to reduce them. Zn, Pb, V and Ni in subway particles presented the highest solubility in artificial lysosomal fluid suggesting high bioavailability in the lung fluids.
Graphene oxide (GOx) is a nanomaterial with demonstrated capacity to remove metals from water. However, its effects on organic pollutants and metal(loid)s present in polluted soils when used for ...remediation purposes have not been extensively addressed. Likewise, few studies describe the effects of GOx on edaphic properties and soil biology. In this context, here we assessed the potential of GOx for remediating polluted soil focusing also on different unexplored effects of GOx in soil. To achieve this, we treated soil contaminated with concurrent inorganic (As and metals) and organic pollution (TPH and PAHs), using GOx alone and in combination with nutrients (N and P sources). In both cases increased availability of As and Zn was observed after 90 days, whereas Cu and Hg availability was reduced and the availability of Pb and the concentration of organic pollutants were not significantly affected. The application of GOx on the soil induced a significant and rapid change (within 1 week) in microbial populations, leading to a transient reduction in biodiversity, consistent with the alteration of several soil properties. Concurrently, the combination with nutrients exhibited a distinct behaviour, manifesting a more pronounced and persistent shift in microbial populations without a decrease in biodiversity. On the basis of these findings, GOx emerges as a versatile amendment for soil remediation approaches.
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•Graphene oxide (GOx) potential for remediation was studied in co-contaminated soil.•GOx increased As and Zn availability, immobilized Cu and Hg, and not affected Pb.•Organic contaminants and germination index were not altered significantly by GOx.•GOx changed soil properties with a subsequent adaptation of microbial communities.
Control over the morphology of TiS3 is demonstrated by synthesizing 1D nanoribbons and 2D nanosheets. The nanosheets can be exfoliated down to a single layer. Through extensive characterization of ...the two morphologies, differences in the electronic properties are found and attributed to a higher density of sulphur vacancies in nanosheets, which, according to density functional theory calculations, leads to an n‐type doping.
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•Cationic state of the Dox in NLCs determined drug release and in vitro efficacy.•NLCs with cationic and neutral Dox were loaded into bacterial cellulose (BC).•The hybrid BC-NCL-NH ...system was efficacious inhibiting tumor growth and metastasis.•BC-NLCs-NH eradicated the side effects of intratumorally administered Dox.
The use of hybrid materials, where a matrix sustains nanoparticles controlling the release of the chemotherapeutic drug, could be beneficial for the treatment of primary tumors prior or after surgery. This localized chemotherapy would guarantee high drug concentrations at the tumor site while precluding systemic drug exposure minimizing undesirable side effects.
We combined bacterial cellulose hydrogel (BC) and nanostructured lipid carriers (NLCs) including doxorubicin (Dox) as a drug model. NLCs loaded with cationic Dox (NLCs-H) or neutral Dox (NLCs-N) were fully characterized and their cell internalization and cytotoxic efficacy were evaluated in vitro against MDA-MB-231 cells. Thereafter, a fixed combination of NLCs-H and NLCs-N loaded into BC (BC-NLCs-NH) was assayed in vivo into an orthotopic breast cancer mouse model.
NLCs-H showed low encapsulation efficiency (48%) and fast release of the drug while NLCs-N showed higher encapsulation (97%) and sustained drug release. Both NLCs internalized via endocytic pathway, while allowing a sustained release of the Dox, which in turn rendered IC50 values below of those of free Dox. Taking advantage of the differential drug release, a mixture of NLCs-N and NLCs-H was encapsulated into BC matrix (BC-NLCs-NH) and assayed in vivo, showing a significant reduction of tumor growth, metastasis incidence and local drug toxicities.
Aims
The purpose of this study was to apply cDNA approach for the characterization of active prokaryotic community to understand microbial scenarios and performance of an AnSBR digester fed with acid ...hydrolysates of Agave tequilana var. azul bagasse (ATAB).
Methods and Results
The digester was implemented for methane production under organic loading rate (OLR) disturbances to correlate physicochemical variables with changes in abundance, diversity and population dynamics of active Bacteria and Archaea by principal components analysis (PCA). Results indicated that methane yield increased as well as active syntrophic relationships for interspecies hydrogen/formate (Anaerolinaceae‐Methanobacterium beijingense) and acetate (Anaerolinaceae‐Methanosaeta concilii) transfers at 8 g‐COD l−1 day−1. However, methane yield was negatively affected at 16 g‐COD l−1 day−1 due to the competition for acetate by active Desulfovibrio marrakechensis and volatile fatty acids inhibition.
Conclusions
Microbial scenarios obtained by PCA correlations indicated that methane production from acid hydrolysates of ATAB was feasible at 8 g‐COD l−1 day−1. The digester operation at higher OLR only favoured methanogenesis by the hydrogenotrophic pathway.
Significance and Impact of the Study
Only cDNA analysis showed Archaea population dynamics, exhibiting high correlation with physicochemical variables towards the understanding of the methanogenic digester performance during OLR disturbances.
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Huntington’s disease (HD) is a hereditary neurodegenerative disease, with peripheral consequences that negatively contribute to quality of life. Circulating microRNAs (cmiRNAs) are ...being explored for their roles in intercellular communication and gene expression regulation, which allows gaining insight into the regulation of crosstalk between neuronal and peripheral tissues. Here, we explore the cmiRNA profile of plasma samples from fifteen symptomatic patients, with 40–45 CAG repeats in the HTT gene, and seven healthy matched controls. Isolated miRNAs from plasma samples were run against human miRNome panels, which have sequences for 752 human mature miRNAs. We found that 168 cmiRNAs are altered in symptomatic patients. Considering Bonferroni’s correction, miR-877-5p, miR-223-3p, miR-223-5p, miR-30d-5p, miR-128, miR-22-5p, miR-222-3p, miR-338-3p, miR-130b-3p, miR-425-5p, miR-628-3p, miR-361-5p, miR-942 are significantly increased in HD patients as compared with controls. Moreover, after patient’s organization according to approved HD scales, miR-122-5p is significantly decreased in HD patients with Unified Huntington’s Disease Rating Scale >24, whereas an increase in miR-100-5p levels and a decrease in miR-641 and miR-330-3p levels were recorded when patients were rearranged by Total Functional Capacity. These results suggest that cmiRNA profile could be further modified by disease progression, making cmiRNAs useful as monitoring biomarkers. Analysis of target genes indicated a general overexpression of cmiRNAs implicated in metabolism regulation. Profiling cmiRNA of HD subjects opens the possibility of personalized therapies for different groups of HD patients, based on disease modifiers: regulation of altered pathways might contribute to not only alleviate disease symptoms, but also influence HD progression.
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