Insoluble Fraction Research Articles

Analysis of cellular effects by continuous exposure AT low concentration of tritium.

This study investigated the induction of DNA double-strand breaks (DSBs) in the hTERT-immortalized normal human diploid epithelial cells (RPE1-hTERT) continuously exposed to 6000Bq/ml of tritiated water (HTO) and organically bound tritium (OBT). The relationship of the DSBs induction with the intracellular amount as well as the localization of tritium was also examined. Tritium-labeled thymidine (3H-Thy) and palmitic acid (3H-PA) were used as OBT. The average number of DSBs, which were indicated as co-localized foci of 53BP1 with phosphorylated H2AX, per cell was higher in the order of treatments with 3H-Thy, 3H-PA, and HTO. This order was consistent with that of tritium localization in the insoluble nuclear fraction but not with the intracellular amount of tritium. In addition to the intracellular amount of tritium, we showed that the subcellular localization of tritium is an important factor in cellular effects stimulated by DSBs.

Mechanistic insights to the strong antioxidative capacity of lingonberry press cake during recovery of fish protein ingredients

Lingonberry press cake (LPC) has been shown to limit lipid oxidation in fish filleting co-products during pH-shift processing. To explore the underlying mechanism, this study subjected LPC to pH-shift processing (native pH → pH 12 → pH 5), and analyzed the resultant fractions for phenolic content and antioxidant capacity. It was observed that LPC experienced a 23.73 % reduction in total phenolic content (TPC) when the initial homogenate was adjusted to pH 12; however, no significant further losses were noted during centrifugation or subsequent adjustment to pH 5. Both LPC and the soluble fraction at pH 5 (“S2”) demonstrated effective inhibition of hemoglobin (Hb)-mediated lipid oxidation in washed cod mince (WCM) model system. Additionally, the insoluble fraction at pH 5 (“P2”) exhibited the strongest binding to WCM. Proanthocyanidin A1 and cyanidin 3-O-galactoside were identified as the most effective antioxidants in LPC. Overall, this study affirms LPC's value as an effective natural antioxidant ingredient in muscle foods and proposes an innovative strategy for valorizing multiple food side streams together to support sustainable development.

The molecular composition of birch tar and its infrared spectrum

Birch tar was the first substance made by humans that is otherwise not available in nature. The oldest artefacts date to ~ 200 thousand years ago in Europe but birch tar becomes more frequent around 45 thousand years ago and even more so from the Mesolithic onwards. Their study has important implication for our understanding of evolutionary processes such as cognitive capacity and cultural evolution. What remains unknown is the overall molecular composition of birch tar. Several approaches based on gas chromatography-mass spectrometry have shown the potential of studying solvent soluble molecules to understand the botanical origin of different tars, their manufacturing techniques and their post-depositional alteration mechanisms. However, birch tar’s soluble fraction cannot shed light on its mechanical properties. In this study, we conduct gas chromatography-mass spectrometry and spectroscopic analysis of seven bulk birch tar samples, including infrared band assignment and structural refinement of organic molecules in the insoluble fraction. We find that the overall proportion that cannot be analysed by gas chromatography accounts for 85–90% in birch tar. This phase consists of polymerised molecules with a structure analogous to asphaltenes but containing a significantly greater amount of oxygen-related functional groups. Our findings have implications for understanding the viscosity, adhesiveness and stiffness of birch tar and they call for caution in applying analytical techniques that only target soluble molecules in birch tar.

Chemical Fingerprinting of PM2.5 via Sequential Speciation Analysis Using Electrochemical Mass Spectrometry.

Chemical fingerprinting to characterize the occurrence state and abundance of organic and inorganic constituents within fine particulate matter (PM2.5) is useful in evaluating the associated health risks and tracing pollution sources. Herein, an analytical strategy for the rapid analysis of metal and organic constituents in PM2.5 was developed employing a combination of sequential chemical extraction coupled with mass spectrometry detection. H2O, CH3OH, EDTA-2Na, electrochemical oxidation, and electrochemical reduction were sequentially utilized to extract the chemical constituents in PM2.5 samples on a homemade device employing simultaneous online detection using two linear trap quadrupole mass spectrometers (LTQ-MS) with electrospray ionization (ESI) in positive and negative modes. After a single analytical procedure, dozens of metals (e.g., Pb, Cr, and Cu), organic compounds (e.g., amines, polycyclic aromatic hydrocarbons, and aliphatic acids), and negative ions (e.g., NO3-, NO2-, and Cl-) were comprehensively detected in the water-soluble, liposoluble, insoluble, oxidizable, and reducible fractions of PM2.5 samples, and their physical and chemical relationships were established.

Optimum Level of Lactobacillus plantarum Supplementation as Probiotic on In Vitro Digestibility and Rumen Fermentation Products in Thai Native Cattle

The objective of this study was to determine in vitro gas production kinetics, and rumen fermentation products of total mixed ration (TMR) supplemented with different level of Lactobacillus plantarum supplementation in Thai native cattle. The experiment design was Completely Randomized Design (CRD). The in vitro procedure was completed using 200 mg DM of TMR and four different concentration of L. plantarum; CON (without supplementation of L. plantarum), T1 (107 CFU / mL of L. plantarum supplementation), T2 (108 CFU / mL of L. plantarum supplementation), and T3 (109 CFU / mL of L. plantarum supplementation). The samples were prepared in three replications and incubated for 96 hours for gas production. Rumen fermentation products (pH, NH3, VFA) and digestibility experiment were done in four replications and incubated for 24 hours. In vitro gas production for 96 hours, gas production from insoluble fraction (b), and potential extent of gas production (|a|+b) were improved in the T1 and T2 groups (P < 0.05). The in vitro dry matter and organic matter digestibility, and true digestibility were particularly enhanced in the T1 group compared to other treatments (P <0.05). The pH and NH3 in this study were significantly affected (P<0.05). The significant improvements on the in vitro rumen fermentation products and digestibility endorse L. plantarum supplementation at concentration of 107 CFU/mL as probiotic candidate.

MiPrime: A model for the microbially mediated impacts of organic amendments on measurable soil organic carbon fractions and associated priming effects

Priming effects can influence the efficiency with which organic amendments sequester carbon in the soil. Yet, few soil models currently include priming effects. Those models that do are often based on operationally defined soil pools and implicitly allow only for positive priming effects. This limits the verification of model processes with experimental data and hinders the optimization of our carbon sequestration strategies. To address these shortcomings, we developed MiPrime, which offers a framework for the mechanistic modelling of organic amendment impacts on microbially mediated transformation of carbon fractions that are quantifiable through parsimonious soil extraction methods. MiPrime allows for assessment of organic amendment impacts on soil carbon dynamics, including priming effects, by simulating changes in mineralized, microbial biomass, dissolvable, hot water extractable and insoluble carbon fractions in soil exogenous (i.e. organic amendment-derived) and endogenous (i.e. soil) pools. After calibration of model parameters using Markov Chain Monte Carlo methods to incubation data of three types of isotopically labelled roadside grasses (a fresh grass product, a compost thereof, and a Bokashi-fermented product thereof), MiPrime was able to simulate changes in carbon fractions of the soil with a good degree of accuracy for five compositionally complex organic amendments, namely the three types of roadside grasses, as well as non-isotopically labelled wood chips and water weeds and reeds. Validation of the model results with experimental data demonstrates that changes in total carbon were very well predicted but that there is room for improvement in predicting mineralization rates and changes in dissolvable, hot water extractable and insoluble carbon fractions in the soil endogenous pool. MiPrime thus offers an initial step towards the mechanistic modelling of organic amendment impacts on measurable soil carbon fractions and can operate as a new tool for designing effective carbon sequestration strategies and understanding organic amendment impacts.

Assessment of the Antioxidative Properties of Extracts from the Fruits of Pyrus pyraster (L.) Burgsd and Pyrus ×myloslavensis Czarna & Antkowiak Grown under Natural Environmental Conditions

Analyses were conducted on extracts from the fruits of P. pyraster and P. ×myloslavensis. Extraction with 80% methanol was performed at room temperature. The total phenolic content was determined by spectrophotometry using the Folin–Ciocalteu reagent, with gallic acid as the reference standard. Phenolic compounds and organic acids were identified on a liquid chromatograph. The antioxidative activity of the extracts was tested in relation to linoleic acid incubation of the emulsions for 19 h based on the neutralization of the DPPH radical (2,2-diphenyl-1-picrylhydrazyl) and the ABTS cation radical (2,2′-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid]) as well as by the ferric reducing antioxidant power (FRAP) assay. The analyses showed that the extract from P. pyraster fruits is characterized by a higher content of phenolic compounds and a higher antioxidative potential compared with that from P. ×myloslavensis. In extracts of both pear species, seven phenolic compounds and four organic acids were identified. The total fiber content in pears of P. pyraster and P. ×myloslavensis was determined at 36.45 g and 24.74 g/100 g d.m. of the pear fruits, of which most comprised the insoluble fraction (32.49 g and 20.86/100 g, respectively). The results of the conducted research are highly significant, as they confirm that pears contain many valuable nutrients and biologically active compounds, including antioxidants and dietary fiber. Adding pear extracts to food products may offer a way to boost their health benefits while also broadening the variety of items that have appealing sensory characteristics. Moreover, research has shown that fruit extracts can help to prolong the shelf life of food products by safeguarding them against lipid oxidation and the decline in their nutritional value.

Investigating how H2S can alter the interactions between Hg0 and corroded steel surfaces to guide future decommissioning projects

Many oil and gas developments will soon be decommissioned and, knowledge on the accumulation of mercury (Hg), throughout offshore infrastructure is limited. Any release of Hg could have a detrimental impact on marine ecosystems. To bridge this knowledge gap, a fractionation approach was taken on steel samples exposed to Hg0 and H2S, separating Hg compounds removed from the surface into polar, non-polar and insoluble fractions. Hg0 reacted on corroded surfaces to form several compounds, over 50 % of which were removed by seawater. This suggests that pipelines on the seabed could release a dramatic amount of Hg into the sea if they are left in place. Furthermore, a Cu-Hg amalgam, was identified to be a dominant species, by a combination of XFM, XANES and LA-ICP-TOFMS. Seawater-soluble and amalgam-bound Hg were present regardless of co-exposure to H2S. When H2S was present Hg nanoparticles accounted for up to 1 % of the total Hg on the steel. This investigation has shown that the Hg speciation on the surfaces of pipelines is complex and future decommissioning strategies should consider a range of Hg species beyond only Hg0 and metacinnabar (β-HgS), all of which could interact with biota and impact Hg biomagnification through the marine the food web.

Size-segregated particulate matter oxidative potential near a ferromanganese plant: Associations with soluble and insoluble elements and their sources

The oxidative potential (OP) of particulate matter (PM) is considered a better health metric of PM exposure than mass concentration since its value is highly dependent on PM composition. OP assays have shown different sensitivities to PM components and particle sizes. In this work, an urban-industrial mixed site with high levels of airborne Mn and Fe, due to the proximity of a ferromanganese alloy plant, was chosen to study the association between PM elements and three OP assays (ascorbic acid (AA), dithiothreitol (DTT), and 2,7-dichlorofluorescein (DCFH)) in size segregated PM samples (PM10-2.5 and PM2.5). Urban samples from a nearby area were also collected. The concentration of 39 elements in both the soluble (in a phosphate buffer aqueous solution) and insoluble fractions of PM10-2.5 and PM2.5 was determined by ICP-MS. Soluble elements were then associated with OP and local sources using Principal Component Analysis (PCA). Four sources of soluble elements have been identified in the urban-industrial site. The main factor was attributed to road traffic; although Cu and Fe, two active transition metals in OP assays, were associated to this factor, their low solubility, mainly in the coarse fraction, has led to low factor loadings of OP; the second factor was attributed to a ferromanganese plant, since it presented the highest factor loadings for soluble Mn in both PM10-2.5 and PM2.5; it was the main factor associated with OP-DTT and OP-DCFH values, mainly in the coarse fraction. Crustal material and sea salt aerosol were also identified as sources.

An insight into PANI-TiO2 photocatalysis of refractory organic matter through molecular size fractionation.

Refractory organic matter (RfOM) is ubiquitous in aquatic environment and plays various roles in regulating the fate, transport, toxicity, and bioavailability of chemical species, such as metals, emerging organic contaminants, and nanomaterials. RfOM is mainly represented by humic acids (HA) as the acid insoluble fraction of organic matrix. Considering the complex and multicomponent characteristic of HA, a detailed study was designed to elucidate the fate of molecular size fractions (MSFrs) of humic under solar irradiation in the presence of polyaniline (PANI)-modified TiO2 composites. Humic acid as a consortium of diverse molecular size fractions with different tendencies towards oxidation requires further assessment by UV-vis and fluorescence spectroscopic parameters complementary to previous studies on the photocatalytic degradation of RfOM by using TiO2 and PANI-TiO2 composites. Absorbance-based removal efficiencies under initial and post-photocatalytic conditions showed a re-formation trend during photocatalysis in the presence of PANI and TiO2 where higher MSFrs were transformed to lower MSFrs that was apparent for < 3kDa fraction. Completely different profiles were observed for PT-41 and PT-81 indicating similar degradation pathways independent of PANI ratio in the composite. As confirmed by the investigated parameters, formation of both 450kDa and 220kDa MSFrs were evident under all conditions indicating in situ generation of higher MSFrs. The eligibility of coupled absorbance-fluorescence measurements to discern molecular size distribution of humic acid via oxidative degradation was also investigated. Excitation-emission matrix (EEM) contour plots emphasized the ratio dependency of PANI modification of TiO2 and revealed sample specific variations that were more pronounced in terms of the emergence of tyrosine- and tryptophan-like aromatic proteins.

Homology Modeling and Expression of Recombinant NS5-RdRp Based on the Indonesian Local Strain of Dengue Virus for Anti-Dengue Drug Development

This study aims to isolate the RNA-dependent RNA polymerase (RdRp) gene of the dengue virus (DENV) isolates from Indonesia, determine the serotype of the local DENV strain through homology modeling, and express the recombinant RdRp protein in Escherichia coli BL21 (DE3), as the target for anti-dengue drug development. We utilize reverse transcription- polymerase chain reaction (RT-PCR) and nested PCR for serotyping the DENV isolates, obtained from Hasan Sadikin Hospital, Indonesia. Then, followed by the extraction and purification of the RdRp amplicon for gene sequencing. The resulting RdRp gene sequences are translated into amino acid sequences, which are then used for protein modeling and the construction of a recombinant plasmid for RdRp protein expression. As the result, the RdRp gene, which belongs to the non-structural protein 5 (NS5) of DENV, was successfully isolated and sequenced from DENV RNA samples. Based on serotyping results and homology modeling, the serotype of the isolate DENV was identified as serotype-3. The isolated NS5-RdRp gene from the local strain was then inserted into the pET28a(+) plasmid and transformed into E. coli BL21(DE3) as the host cell. Recombinant NS5-RdRp was predominantly found in the insoluble fraction with a molecular weight of 72 kDa. Future studies on the development of an anti-dengue drug model that confirms the inhibition of the binding domain in the recombinant RdRp protein structure will be required to provide more insight and expand the development of a universal anti-dengue strategy in Indonesia.

A screening method for detection of TiO2 in food based on Raman spectroscopy and its applicability in a regulatory context

Starting from August 7, 2022, with the publication of the European Regulation EU 2022/63, the European Commission has prohibited the use of titanium dioxide (TiO2) (E 171) as a food additive within the European Union (EU). As the food industry has the obligation to adapt the formulation of their products accordingly, it is now crucial for EU member states' competent authorities and official control laboratories to have adequate analytical methods to ensure compliance with this new regulation. The existing literature predominantly focuses on quantitatively determining the elemental titanium (Ti) concentration by ICP-based techniques after complete digestion of the analyte and the food matrix. Compared to this approach, Raman spectroscopy would offer the possibility of a more rapid albeit qualitative screening by identifying the insoluble fraction of titanium dioxide after removing the food matrix. It is also important to note that compliance with the EU ban requires determining the presence of TiO2 in particulate form, an information that Raman spectroscopy can easily deliver. As a further advantage, an analytical approach based on Raman spectroscopy eliminates the need for using particularly harmful acids, which are necessary for the complete digestion of TiO2, when ICP-based analytical methods are employed. In the present study, the aim was first to gather information on the commonly occurring total Ti levels in food and, second, to discuss the potential of a newly developed Raman procedure based on TiO2 extraction by mild acid digestion of the food product as a rapid, safer albeit qualitative screening method. To evaluate the effectiveness of the Raman procedure in verifying compliance with the European Regulation, the qualitative results obtained using a macro-Raman instrument were compared with those obtained through ICP-based techniques on the same food samples, used as benchmark. In total 22 food-samples belonging to 6 different food categories were analysed. The sampling was conducted in the Italian, Belgian, and French markets both before and after the EU ban on E 171 entered into force. The limit of detection, qualitatively established, was 50 mg kg−1, which effectively encompasses the majority of food items containing E 171, as supported by the extensive literature review. The results obtained with the Raman screening method were found to align well with information reported on product labels and benchmark quantitative data.

Spatially resolved chemical data for PM10 and oxidative potential source apportionment in urban-industrial settings

This study proposes the use of spatially resolved data to identify local sources contributing to PM10 mass concentration and OP in urban-industrial contexts. Over a 18-month monitoring campaign spanning from October 2020 to May 2022, a low-volume PM10 sampling device was employed at 12 sites in the Sacco River Valley, Italy. PM10 samples were analyzed for OP by applying the DTT, AA, and DCFH assays, and for 77 chemical parameters: the main chemical components (major elements, inorganic ions, EC, OC, levoglucosan) and the water-soluble and insoluble fractions of 28 elements. Source apportionment via PMF analysis on spatially resolved data revealed seven PM10 source contributions, notably biomass burning and soil dust. Biomass burning predominated in winter, while soil dust prevailed in summer. Spatial variability in source contributions was observed due to diverse biomass types, domestic heating, and proximity to the cement plant and transportation networks. Bubble maps and FPCA represented OP and PM10 source relationships, highlighting biomass burning as the main contributor to OPDTT and OPDCFH, while non-exhaust traffic contributed significantly to OPAA. Findings from this study provide valuable insights into planning effective air pollution mitigation policies aimed at enhancing air quality in urban-industrial contexts.

Thermomechanically micronized sugar beet pulp: Elucidating the interaction of soluble elements and insoluble fibrous particles for enhancing emulsification

The micronization of plant particles usually transfers substantial insoluble fraction into soluble elements, resulting in a soluble-insoluble binary system and the content of soluble elements can not be neglected. The present work aims to investigate the interaction between soluble elements and insoluble particles obtained from sugar beet pulp by microwave heating with ultrasonication, and their contribution to the synergistic emulsification performance. The soluble elements (∼40%) (sugar beet pectic substance, SBPS) and insoluble fibrous particles (IFPs) were separated from micronized sugar beet pulp (MSBP). Quartz crystal microbalance with dissipation analysis revealed that SBPS could irreversibly adsorb onto IFPs with an adsorbed mass of 32.2 μg/mg Fiber. By adopting sequential extraction and specific enzymatic hydrolysis for the modification of IFPs and SBPS, it was found that their non-saccharide fraction played an important role in the interaction. Larger molecular weight subfractions with abundant protein and ferulic acid content were the main adsorbable fraction in SBPS, and the interaction was driven by hydrophobic interaction. The soluble-insoluble binary system promoted the interfacial adsorption of both IFPs (from 65.6% to 82.2%) and SBPS (from 9.6% to 19.6%), forming a hybrid interfacial coverage (with SBPS-coated IFPs and SBPS) and endowing emulsion with better stability. These findings provided a guideline for understanding the emulsification mechanism of plant particles.

Increased Homer Activity and NMJ Localization in the Vestibular Lesion het-/- Mouse soleus Muscle.

We investigated the shuttling of Homer protein isoforms identified in soluble (cytosolic) vs. insoluble (membrane-cytoskeletal) fraction and Homer protein-protein interaction/activation in the deep postural calf soleus (SOL) and non-postural gastrocnemius (GAS) muscles of het-/- mice, i.e., mice with an autosomal recessive variant responsible for a vestibular disorder, in order to further elucidate a) the underlying mechanisms of disrupted vestibular system-derived modulation on skeletal muscle, and b) molecular signaling at respective neuromuscular synapses. Heterozygote mice muscles served as the control (CTR). An increase in Homer cross-linking capacity was present in the SOL muscle of het-/- mice as a compensatory mechanism for the altered vestibule system function. Indeed, in both fractions, different Homer immunoreactive bands were detectable, as were Homer monomers (~43-48 kDa), Homer dimers (~100 kDa), and several other Homer multimer bands (>150 kDA). The het-/- GAS particulate fraction showed no Homer dimers vs. SOL. The het-/- SOL soluble fraction showed a twofold increase (+117%, p ≤ 0.0004) in Homer dimers and multimers. Homer monomers were completely absent from the SOL independent of the animals studied, suggesting muscle-specific changes in Homer monomer vs. dimer expression in the postural SOL vs. the non-postural GAS muscles. A morphological assessment showed an increase (+14%, p ≤ 0.0001) in slow/type-I myofiber cross-sectional area in the SOL of het-/- vs. CTR mice. Homer subcellular immuno-localization at the neuromuscular junction (NMJ) showed an altered expression in the SOL of het-/-mice, whereas only not-significant changes were found for all Homer isoforms, as judged by RT-qPCR analysis. Thus, muscle-specific changes, myofiber properties, and neuromuscular signaling mechanisms share causal relationships, as highlighted by the variable subcellular Homer isoform expression at the instable NMJs of vestibular lesioned het-/- mice.

Fabrication, optimization, and in vitro validation of penicillin-loaded hydrogels for controlled drug delivery

Bacterial infections present a major global challenge. Penicillin, a widely used antibiotic known for its effectiveness and safety, is frequently prescribed. However, its short half-life necessitates multiple high-dose daily administrations, leading to severe side-effects. Therefore, this study aims to address these issues by developing hydrogels which control the release of penicillin and alleviate its adverse effects. Various combinations of aspartic acid and acrylamide were crosslinked by N′, N′-methylene bisacrylamide through a free radical polymerization process to prepare aspartic acid/acrylamide (Asp/Am) hydrogels. The fabricated hydrogels underwent comprehensive characterization to assess physical properties and thermal stability. The soluble and insoluble fractions and porosity of the synthesized matrix were evaluated by sol-gel and porosity studies. Gel fraction was estimated at 88–96%, whereas sol fraction was found 12–4% and porosity found within the 63–78% range for fabricated hydrogel formulations. Maximum swelling and drug release were seen at pH 7.4, demonstrating a controlled drug release from hydrogel networks. The results showed that swelling, porosity, gel fraction, and drug release increased with higher concentrations of aspartic acid and acrylamide. However, integration of N′, N′-methylene bisacrylamide exhibited the opposite effect on swelling and porosity, while increasing gel fraction. All formulations followed the Korsymer–Peppas model of kinetics with ‘r’ values within the range of 0.9740–0.9980. Furthermore, the cytotoxicity study indicated an effective and safe use of hydrogel because the cell viability was higher than 70%. Therefore, these prepared hydrogels show promise candidates for controlled release of Penicillin and are anticipated to be valuable in clinical applications.

Rotenone and Its Derivative, Rotenoisin A, Induce Neurodegeneration Differentially in SH-SY5Y Cells.

Rotenone (ROT), the most significant rotenoid, which has shown anticancer activity, has also been reported to be toxic to normal cells, inducing Parkinson's disease (PD)-like neuronal loss with aggregation of α-synuclein (α-syn). To reduce the adverse effects of ROT, its derivative, rotenoisin A (ROA), is obtained by directly irradiating a ROT solution in methanol using γ-rays, which has been reported for potential anticancer properties. However, its PD-inducing effects have not yet been researched or reported. This study sought to compare the activities of ROA and ROT on the aggregation of α-syn, apoptosis, and autophagy in SH-SY5Y cells. ROA decreased cell survival less when compared with ROT on SH-SY5Y cells at 48 h in a dose-dependent manner. ROT (0.5 and 1 μM) and ROA (4 and 5 μM) decreased the expression of tyrosine hydroxylase. Western blot analysis of the Triton X-100 insoluble fraction revealed that both ROT and ROA significantly increased the levels of oligomeric, dimeric, and monomeric phosphorylated Serine129 α-syn and total monomeric α-syn. Moreover, both compounds decreased the proportion of neuronal nuclei, the neurofilament-heavy chain, and β3-tubulin. The phosphorylation of ERK and SAPK were reduced, whereas ROA did not act on Akt. Additionally, the increased Bax/Bcl-2 ratio further activated the downstream caspases cascade. ROT promoted the LC3BII/I ratio and p62 levels; however, different ROA doses resulted in different effects on autophagy while inducing PD-like impairments in SH-SY5Y cells.

Deciphering the uranium isotopic signature of coastal water and sediments from Tokyo Bay using a multi-collector inductively coupled plasma mass spectrometer

We have measured 236U/238U and 235U/238U values in JMS-1 (geochemical reference material of Tokyo Bay sediments) and coastal seawater using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) equipped with both the retarding potential quadrupole lens and desolvating nebuliser system. For the accurate measurement of 236U/238U values (e.g., in the range of 10−9), mass spectrometric interferences on 236U isotope from both the peak tailing of 238U and polyatomic ion of 235UH were carefully corrected. With the sequential extraction experiments for JMS-1, whose U isotopic signatures were characteristic of isotopically-depleted U with industrial uses, authigenic U was extracted into a soluble fraction, and lithogenic U and anthropogenic U were gathered in an insoluble fraction. The anthropogenic U is likely to have been provided in insoluble forms and have deposited on the bay floor. Absence in differences of 236U/238U and 235U/238U values for seawater observed between inside and outside Tokyo Bay implies the negligibly small contribution of the anthropogenic U to U in the seawater. The data obtained here demonstrate the effective reduction of the interferences on 236U and the versatility of the isotopic signatures of U as an effective tracer for environmental circulation of U in nature.

Tau protein profiling in tauopathies: a human brain study

Abnormal accumulation of misfolded and hyperphosphorylated tau protein in brain is the defining feature of several neurodegenerative diseases called tauopathies, including Alzheimer’s disease (AD). In AD, this pathological change is reflected by highly specific cerebrospinal fluid (CSF) tau biomarkers, including both phosphorylated and non-phosphorylated variants. Interestingly, despite tau pathology being at the core of all tauopathies, CSF tau biomarkers remain unchanged in certain tauopathies, e.g., progressive supranuclear palsy (PSP), Pick’s disease (PiD), and corticobasal neurodegeneration (CBD). To better understand commonalities and differences between tauopathies, we report a multiplex assay combining immunoprecipitation and high-resolution mass spectrometry capable of detecting and quantifying peptides from different tau protein isoforms as well as non-phosphorylated and phosphorylated peptides, including those carrying multiple phosphorylations. We investigated the tau proteoforms in soluble and insoluble fractions of brain tissue from subjects with autopsy-confirmed tauopathies, including sporadic AD (n = 10), PSP (n = 11), PiD (n = 10), and CBD (n = 10), and controls (n = 10). Our results demonstrate that non-phosphorylated tau profiles differ across tauopathies, generally showing high abundance of microtubule-binding region (MTBR)-containing peptides in insoluble protein fractions compared with controls; the AD group showed 12–72 times higher levels of MTBR-containing aggregates. Quantification of tau isoforms showed the 3R being more abundant in PiD and the 4R isoform being more abundant in CBD and PSP in the insoluble fraction. Twenty-three different phosphorylated peptides were quantified. Most phosphorylated peptides were measurable in all investigated tauopathies. All phosphorylated peptides were significantly increased in AD insoluble fraction. However, doubly and triply phosphorylated peptides were significantly increased in AD even in the soluble fraction. Results were replicated using a validation cohort comprising AD (n = 10), CBD (n = 10), and controls (n = 10). Our study demonstrates that abnormal levels of phosphorylation and aggregation do indeed occur in non-AD tauopathies, however, both appear pronouncedly increased in AD, becoming a distinctive characteristic of AD pathology.

Sustainable Light‐Assisted 3D Printing of Bio‐Based Microwave‐Functionalized Gallic Acid

AbstractThe development of 3D printing technologies and the requirement for more sustainable 3D printing materials is constantly growing. However, ensuring both sustainability and performance of the new materials is crucial to replace current fossil‐based polymers. Here, a bio‐based UV‐curable resin is produced in high yield from gallic acid (GA), a natural polyphenolic compound, by means of rapid and efficient microwave‐assisted methacrylation (5 min heating time and 10 min at 130 °C). The successful microwave‐assisted methacrylation with a high degree of substitution is confirmed by Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance spectroscopy. The radical UV‐photopolymerization of the methacrylated gallic acid (MGA) is further investigated by real‐time FTIR and differential scanning photo calorimetry (photo‐DSC) analyses, clearly demonstrating the high photo‐reactivity of MGA. Moreover, the %gel assessment demonstrates the formation of highly insoluble fractions after the UV‐curing, with 98% gel content. The photo‐rheology and rheology support the suitability of MGA for light‐assisted 3D printing. Indeed, a honeycomb and a hollow cube are 3D printed by means of the digital light processing 3D printing technique with high accuracy in a small scale. Finally, the cured‐MGA illustrates high Tg and thermal stability.