Abstract Rock-forming silicate minerals such as feldspars, garnets, and vesuvianite can contain elevated arsenic (As) contents and, therefore, are potentially important contributors to As contamination via chemical weathering and other processes. This study investigated a suite of 16 vesuvianite samples by combining inductively coupled plasma mass spectrometry (ICP-MS), electron paramagnetic resonance (EPR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and synchrotron X-ray absorption spectroscopy (XAS). ICP-MS analyses show that the vesuvianite samples contain 1.11 to 2041 ppm As, with the majority (69%) having ≥29 ppm As. The EPR spectra measured before and after gamma-ray irradiation reveal Fe3+, Mn2+, and VO2+ centers but do not have any arsenic-related oxyradicals. Microbeam As 3d XPS and bulk As K-edge XAS analyses both suggest mixed As3+ and As5+ oxidation states in vesuvianite. The As5+/ΣAs values (where ΣAs = As3+ + As5+) of vesuvianite calculated from As 3d XPS and As K-edge XAS correlate positively with the Fe3+/ΣFe values from Fe 2p XPS data, suggesting an oxygen fugacity effect. Fittings of As K-edge extended X-ray absorption fine structure (EXAFS) data of an As3+ dominant sample show that this species resides mainly at the T1 site in vesuvianite. The occurrences of mixed As3+ and As5+ species in vesuvianite add to the complexity in the uptake and release mechanisms of this heavy element.

A soluble fraction of faba bean protein was conjugated with tannic acid via the free-radical grafting method using a mixture of ascorbic acid and hydrogen peroxide. Surface plasmon resonance showed a strong bonding between them, while the free amino and thiol group measurements indicated tannic acid's bonding with the amino groups and cysteine residues on the proteins. Structural analysis using intrinsic fluorescence and surface hydrophobicity demonstrated tannic acid's interaction with the aromatic and hydrophobic amino acids of the protein. The conjugate showed about 77 % DPPH, 89 % ABTS, and 83 % hydroxyl radical scavenging activities and superior ferric-reducing ability compared to the protein alone and the mixture of protein and tannic acid. Electron paramagnetic resonance (EPR) spectroscopy revealed 97.8 % radical scavenging ability of the conjugate, comparable to the pure tannic acid. The exceptional antioxidative properties of conjugate can be utilized to delay lipid oxidation in protein-stabilized oil-in-water emulsions.

Fullerene-like amorphous carbon nitride films (FL-CN x ) were prepared onto gold substrates by hot-wire plasma graphite sputtering using different %N 2 in the Ar plasma discharge. Atomic force microscopy measurements revealed ultra-smooth films with a root mean squared roughness (R RMS ) values in the range of 1.2–2.1 nm. The N/C and O/C atomic ratios were evaluated from the near-edge X-ray absorption fine structure (NEXAFS) spectra obtained for the carbon, nitrogen, and oxygen K-edge regions from scanning transmission X-ray microscopy measurements. Nitrogen-incorporation into the films showed very subtle changes in the electronic structure for films prepared by different %N 2 plasma discharge gas. Contact angle showed and increase in surface wettability while Raman spectroscopy measurements showed an increase in sp 2 ordered rings with nitrogen incorporation into the films, but both film properties reverse when the plasma gas discharge contained 30% N 2 . The binding kinetics of human serum albumin (HSA) and fibrinogen (Fib) were evaluated by surface plasmon resonance. In general, binding affinity was controlled by the rate of association kinetics ( k a ) for both proteins, as the rate of dissociation kinetics ( k d ) was approximately the same for FL-CN x films. The k a value for Fib was approximately 6–20 times larger compared to HSA, but nitrogen incorporated films initially lowered the k a values for both proteins, but too much %N 2 plasma discharge gas increased k a . It was also demonstrated that pre-saturating an amorphous carbon surface with HSA decreased the surface capacity of Fib by approximately 34-fold.

Lentil protein isolate (LPI) was conjugated with plant polyphenols (quercetin, rutin, ellagic acid), and the structural and functional characteristics of the conjugates were determined in comparison with the proteins and pure polyphenols. The interaction between polyphenols and protein was achieved by a grafting method at pH 9.0 in the presence of atmospheric oxygen. Surface plasmon resonance measurements showed polyphenols' direct interaction with LPI, with the order of binding strength quercetin > ellagic acid > rutin. The degree of conjugation also followed the same order. Structural analysis of the conjugates was performed using FTIR, intrinsic fluorescence, and surface hydrophobicity. A significant improvement in DPPH radical scavenging and ferric reducing antioxidant power of the conjugates was observed compared to the polyphenols. However, there was a decrease in the surface activity of the conjugates compared to LPI. Such conjugation provides a novel way to combine the advantages of using plant protein and polyphenols in developing a novel food ingredient.

More than 2 million years ago in East Africa, the earliest hominin stone tools evolved amidst changes in resource base, with pounding technology playing a key role in this adaptive process. Olduvai Gorge (now Oldupai) is a famed locality that remains paramount for the study of human evolution, also yielding some of the oldest battering tools in the world. However, direct evidence of the resources processed with these technologies is lacking entirely. One way to obtain this evidence is through the analysis of surviving residues. Yet, linking residues with past processing activities is not simple. In the case of plant exploitation, this link can only be established by assessing site-based reference collections inclusive of both anthropogenic and natural residues as a necessary first step and comparative starting point. In this paper, we assess microbotanical remains from rock clasts sourced at the same quarry utilized by Oldowan hominins at Oldupai Gorge. We mapped this signal and analysed it quantitatively to classify its spatial distribution objectively, extracting proxies for taxonomic identification and further comparison with freestanding soils. In addition, we used blanks to manufacture pounding tools for blind, controlled replication of plant processing. We discovered that stone blanks are in fact environmental reservoirs in which plant remains are trapped by lithobionts, preserved as hardened accretions. Tool use, on the other hand, creates residue clusters; however, their spatial distribution can be discriminated from purely natural assemblages by the georeferencing of residues and statistical analysis of resulting patterns. To conclude, we provide a protocol for best practice and a workflow that has the advantage of overcoming environmental noise, reducing the risk of false positive, delivering a firm understanding of residues as polygenic mixtures, a reliable use of controls, and most importantly, a stronger link between microbotanical remains and stone tool use.

In commercial Li-ion batteries, the internal short circuits or over-lithiation often cause structural transformation in electrodes and may lead to safety risks. Herein, we investigate the over-discharged mechanism of LiCoO2/graphite pouch cells, especially spatially resolving the morphological, surface phase, and local electronic structure of LiCoO2 electrode. With synchrotron-based X-ray techniques and Raman mapping, together with spectroscopy simulations, we demonstrate that over-lithiation reaction is a surface effect, accompanied by Co reduction and surface structure transformation to Li2CoO2/Co3O4/CoO/Li2O-like phases. This surface chemical distribution variation is relevant to the depth and exposed crystalline planes of LiCoO2 particles, and the distribution of binder/conductive additives. Theoretical calculations confirm that Li2CoO2-phase has lower electronic/ionic conductivity than LiCoO2-phase, further revealing the critical effect of distribution of conductive additives on the surface chemical heterogeneity evolution. Our findings on such surface phenomena are non-trivial and highlight the capability of synchrotron-based X-ray techniques for studying the spatial chemical phase heterogeneity.

The pool of β-Amyloid (Aβ) length variants detected in preclinical and clinical Alzheimer disease (AD) samples suggests a diversity of roles for Aβ peptides. We examined how a naturally occurring variant, e.g. Aβ(1–38), interacts with the AD-related variant, Aβ(1–42), and the predominant physiological variant, Aβ(1–40). Atomic force microscopy, Thioflavin T fluorescence, circular dichroism, dynamic light scattering, and surface plasmon resonance reveal that Aβ(1–38) interacts differently with Aβ(1–40) and Aβ(1–42) and, in general, Aβ(1–38) interferes with the conversion of Aβ(1–42) to a β-sheet-rich aggregate. Functionally, Aβ(1–38) reverses the negative impact of Aβ(1–42) on long-term potentiation in acute hippocampal slices and on membrane conductance in primary neurons, and mitigates an Aβ(1–42) phenotype in Caenorhabditis elegans . Aβ(1–38) also reverses any loss of MTT conversion induced by Aβ(1–40) and Aβ(1–42) in HT-22 hippocampal neurons and APOE ε4-positive human fibroblasts, although the combination of Aβ(1–38) and Aβ(1–42) inhibits MTT conversion in APOE ε4-negative fibroblasts. A greater ratio of soluble Aβ(1–42)/Aβ(1–38) [and Aβ(1–42)/Aβ(1–40)] in autopsied brain extracts correlates with an earlier age-at-death in males (but not females) with a diagnosis of AD. These results suggest that Aβ(1–38) is capable of physically counteracting, potentially in a sex-dependent manner, the neuropathological effects of the AD-relevant Aβ(1–42).

In recent years, contamination of the environment with microplastics has received increasing scientific and public attention. Wastewater treatment plants (WWTPs) are considered important emitters of microparticles into aquatic systems. Among these microparticles are microplastics from, e.g., cosmetic products, and microfibers that are released during laundry of textiles made from synthetic fibers. The purpose of this study was to qualitatively and quantitatively characterize microplastic and microfiber contamination in effluents of the City of Saskatoon WWTP, Saskatchewan, Canada. The WWTP discharges directly into the South Saskatchewan River, which is an important water resource of central economic and environmental importance to the Canadian Prairies. To achieve this goal, a reference dataset was developed by determining Raman and Fourier-transform infrared (FTIR) spectra of neat plastic standards. Subsequently, samples were obtained from the final effluent of the Saskatoon WWTP during winter, spring, and summer 2019 by use of fine-meshed plankton nets. Microplastics and microfibers were extracted using Fenton oxidation and filtration, counted, and their identity determined by comparing Raman and FTIR spectra of individual microplastics and microfibers with the previously developed reference dataset. The number concentrations of both microplastics and microfibers were relatively stable across seasons, and fibers accounted for 82% of the total number of synthetic microparticles. Although the average total number concentration of microplastics and microfibers was only 1.76 per liter of effluent, at an average daily discharge of 80 million liters, this would amount to the emission of 141 million particles into the river per day. While the environmental relevance of these findings remains to be demonstrated, these results are an important first step toward understanding the magnitude of microplastic contamination in the Canadian Prairies.

Ancient dental calculus research currently relies on destructive techniques whereby archeological specimens are broken down to determine their contents. Two strategies that could partly remediate a permanent loss of the original sample and enhance future analysis and reproducibility include (1) structural surface characterization through spectroscopy along with crystallographic and spectroscopic analysis of its molecular structure, and (2) surface decontamination protocols in which the efficacy of cleaning dental calculus prior to extraction is demonstrated. Dental calculus provides ancient starch research a niche where granules may be adsorbed to minerals, coated, overgrown, entrapped, and/or protected from chemical degradation. While encapsulation offers protection from degradation, it does not shield the sample’s surface from contamination. The most common approach to retrieving microbotanical particles from archeological calculus has been the direct decalcification of the sample, after a cleaning stage variously consisting of immersion in water, acids, and mechanical dislodgment via gas, sonication, and/or toothbrushes. Little is known about the efficiency of these methods for a complete removal of sediment/soil and unrelated microbotanical matter. In this paper, controlled laboratory experimentation leads to chemical structural characterization and a decontamination protocol to eradicate starch granules. Several concentrations of acids, bases, and enzymes were tested at intervals to understand their potential to gelatinize and fully destroy starch granules; arriving at a procedure that effectively eradicates modern starch prior to dissolution without damaging the matrix or entrapped starch microremains. This is the first attempt at creating synthetic calculus to understand and systematically test effective decontamination protocols for ancient starch research.

Oxide and nitride phases of NiMo supported on Al2O3 were employed for hydrodeoxygenation (HDO) of oleic acid. Synthesized catalysts were characterized using Raman Spectroscopy, X-ray absorption near edge structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS). Raman spectroscopy was employed to understand the active-site distribution in NiMo catalysts and elucidate the relation between distribution of active species and catalytic activity. Catalyst evaluation studies showed that NiMo supported on gamma-Al2O3 has higher conversion (80%) in comparison to NiMo supported on SBA-15 and HMS during the HDO of oleic acid. Raman maps were obtained for the oxide phase of catalyst and it indicates that the Mo supported on Al2O3 is present as polyanions ([Mo7O24](6-) or [Mo8O26](4-)). XANES and EXAFS analyses were carried out to understand the oxidation state and co-ordination environment of the catalyst. Occurrence of Mo-Ni and Mo-Mo interactions were proved by the Mo K-edge EXAFS spectra and the bond lengths were determined. The presence of the promoter metal (Nickel) aids in the hydrogenation of oleic acid to stearic acid and direct hydrodeoxygenation, decarboxylation and decarboxylation reactions were observed. The occurrence of polymeric molybdates as confirmed by the Raman spectroscopy leads to the decrease in the availability of active metals for the selective removal of water without breaking the carbon bond leading to the formation of C18H38.

Synchrotron micro X-ray fluorescence (XRF) spectroscopy with two-dimensional element mapping, micro X-ray diffraction (XRD), electron spin resonance spectroscopy (ESR) and atomic force microscopy (AFM) were used to investigate the chemical and structural nature of the enamel of a tooth from Troodon, a small theropod dinosaur. These methods show that the crystallites in the Troodon tooth are submicron-sized carbonated calcium hydroxyapatite, which are semi-randomly oriented with a preferred orientation of (002) towards the surface of the tooth. Transition metal ions are distributed in the voids between crystallite clusters. Comparison of the ESR spectra indicates that the Troodon tooth had less exposure to UV than a fossilized crocodile tooth.

Stroke is a major global health problem, with the prevalence and economic burden predicted to increase due to aging populations in western society. Following stroke, numerous biochemical alterations occur and damage can spread to nearby tissue. This zone of “at risk” tissue is termed the peri-infarct zone (PIZ). As the PIZ contains tissue not initially damaged by the stroke, it is considered by many as salvageable tissue. For this reason, much research effort has been undertaken to improve the identification of the PIZ and to elucidate the biochemical mechanisms that drive tissue damage in the PIZ in the hope of identify new therapeutic targets. Despite this effort, few therapies have evolved, attributed in part, to an incomplete understanding of the biochemical mechanisms driving tissue damage in the PIZ. Magnetic resonance imaging (MRI) has long been the gold standard to study alterations in gross brain structure, and is frequently used to study the PIZ following stroke. Unfortunately, MRI does not have sufficient spatial resolution to study individual cells within the brain, and reveals little information on the biochemical mechanisms driving tissue damage. MRI results may be complemented with histology or immuno-histochemistry to provide information at the cellular or sub-cellular level, but are limited to studying biochemical markers that can be successfully “tagged” with a stain or antigen. However, many important biochemical markers cannot be studied with traditional MRI or histology/histochemical methods. Therefore, we have developed and applied a multi-modal imaging platform to reveal elemental and molecular alterations that could not previously be imaged by other traditional methods. Our imaging platform incorporates a suite of spectroscopic imaging techniques; Fourier transform infrared imaging, Raman spectroscopic imaging, Coherent anti-stoke Raman spectroscopic imaging and X-ray fluorescence imaging. This approach does not preclude the use of traditional imaging techniques, and rather it should be use to complement traditional methods such as MRI or histology and immunohistochemistry, to gain a greater insight into disease mechanisms. We demonstrate the potential of this approach by characterizing biochemical alterations within the PIZ 24 h after the induction of photothrombotic stroke in mice. Substantial molecular and elemental alterations were identified in the PIZ 24 h after stroke that are consistent with tissue swelling and edema, but not oxidative stress. This reveals important mechanistic information, that could not previously be obtained, which should be considered in future studies aimed at developing therapeutic intervention from this model.

Flaxseed as well as its oil component possess antitumor activities against different types of cancer and have been used by some patients as complementary and/or alternative medicine. Linoorbitides (LOBs) are one family of flaxseed compounds that has implications for anticancer and antioxidant activity. The cytotoxicity of [1-9-NαC]-linusorb-B3 (LOB3), [1-9-NαC]-linusorb-B2 (LOB2), [1-9-NαC],[1-Rs,Ss-MetO]-linusorb-B2 ([MetO]-LOB2) and [1-8-NαC],[1-Rs,Ss-MetO]-linusorb-B1 ([MetO]-LOB1) was measured against human breast cancer Sk-Br-3 and MCF7 cell lines and melanoma A375 cell line. Overall cytotoxicity is cell-type specific. It scales as the hydrophobicity and concentration of the LOBs with the most abundant LOB3 being the most cytotoxic. Oral administration of LOB3 as a potential therapeutic agent might not be applicable as a much too high and/or frequent dose would be required to achieve a serum concentration of 400–500 μg/mL due to bioavailability and pharmacokinetic factors. However, LOB3 may be suitable for topical treatment formulations or as a lead compound in developing anticancer LOB derivatives.

Lignocellulosic feedstocks are potential resources for renewable fuels. However, the cross-linked and hydrophobic lignin makes the biomass recalcitrant to acids and enzymatic conversion. This study investigates the effect of hydrothermal pretreatment and delignification on lignocellulosic biomass from forestry (pinewood), agriculture (wheat straw) and energy crop systems (timothy grass). In order to understand their physico-chemical properties, the pretreated and delignified feedstocks were characterized through carbon-hydrogen-nitrogen-sulfur analysis, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. Hydrothermal pretreatment caused remarkable loss of hemicelluloses (up to 68.4%) and intense lignin re-localisation. Delignification of feedstocks led to significant removal of lignin by 95.9% and exposed the interwoven cellulose fibers. As a result of the removal of hemicelluloses and lignin, cellulose concentration increased by 28.4% in hydrothermally treated feedstocks and 61.4% in delignified feedstocks, respectively. The amplification in cellulose content in delignified feedstocks suggested enhanced accessibility of cellulolytic enzymes for improved bioconversion.

Sphingosine‐1‐phosphate (S1P) is an endogenous metabolite derived from ceramide as part of the sphingomyelin cycle. It is a potent molecular messenger which exerts its function both intracellularly and extracellularly. Intracellularly, S1P acts as a second messenger regulating calcium mobilization, and cellular proliferation and survival. Extracellularly, S1P acts as a ligand of the G‐protein‐coupled S1P receptors (S1PRs) and mediates a variety of physiological and pathological processes. Levels of S1P and other sphingosine metabolites are maintained in a delicate balance through the action of two enzymes, sphingosine kinase (SK) and sphingosine‐1‐phosphate lyase (SPL). Our previous studies showed that exogenously administered S1P (concentration: 1 µM) exhibited synergistic effects with chemotherapy drugs in human breast cancer MCF7 and MDA‐MB‐361 cells [1, 2]. Herein, we report other cell lines and mouse xenograf study results on the antitumor activity of S1P.

Hedyotis diffusa is a Chinese herbal medicine widely used in combination with other herbal medicines such as Scutellaria barbata to treat various types of cancer. Late-stage and recurrent cancer patients usually use H. diffusa during chemotherapy in expecting to achieve additive or synergistic therapeutic effects. Several classes of active ingredients, including anthraquinones, iridoid glucosides and stigmasterols. have been isolated and characterized from H. diffusa. In the current study, we isolated alkaloid/flavonoid from H diffusa and showed that the crude alkaloid/flavonoid extract rather than its three major components possessed antitumor activity against human breast cancer cell line MCF7. Co-administration of H. diffusa water extract diminished the cytotoxicities of chemotherapy drugs doxorubicin, cyclophosphamide and docetaxel towards the MCF7 cells, implicating that H. diffusa should not be used during breast cancer chemotherapy.

Au nanoparticles coated with glutathione (GSH) were prepared by the heat-assisted reduction of Au(I)-thiol complex at 1:1 or 5:4 molar ratio of Au to GSH. The 1:1 sample has three emissions at 610, 645 and 800 nm while the 5:4 sample has a dominant emission at 800 nm but the two emissions at 610 and 645 nm are very weak. It was found in separations that the 610 and 645 nm emissions are closely related while the 800 nm emission behaves in a different way. By adding NaOH, the 800 nm emission decreases while the red emission increases in intensity at low concentration, but both the red and the NIRL emissions are quenched at high concentrations. The luminescence lifetimes of the red emissions were on the nanosecond time scale while the 800 nm emission was on the microsecond time scale. Based on these observations, it is concluded that the red emission is from a single excited states while the 800 nm emission is originated from surface states. Also, for the first time, X-ray excited luminescence is reported here from Au nanoparticles and the applications of these nanoparticles for cell imaging is also investigated.

The use of carbon nanotube (CNT) films for strain detection is one of the most encouraging findings in the field of sensors. Our previous studies have shown that the density of the CNT networks (randomly distributed) plays an important role in governing the piezoresistive response in CNT films under the in-plane straining. The influence of aligned CNT networks on the piezoresistive response is presented. In particular, the CNTs are first decorated with iron oxide nanoparticles (to enhance magnetism), and then the decorated CNTs are used to form aligned CNT networks in the films with the aid of a magnetic field. The films are loaded in the three points bending tester, and their piezoresistive response is investigated under a cycled in-plane straining. The results show that the CNT networks aligned at 0° to electrodes and 90° to electrodes exhibit the highest and the lowest piezoresistive sensitivity, respectively, but the poor repeatability (i.e., severe resistant reduction −6% to −27%) is also found in the CNT networks aligned at 0° to electrodes.

Purpose: Detonation nanodiamonds (NDs) are carbon-based nanomaterials that, because of their size (4-5 nm), stable inert core, alterable surface chemistry, fluorescence, and biocompatibility, are emerging as bioimaging agents and promising tools for the delivery of biochemical molecules into cellular systems. However, diamond particles possess a strong propensity to aggregate in liquid formulation media, restricting their applicability in biomedical sciences. Here, the authors describe the covalent functionalization of NDs with lysine in an attempt to develop nanoparticles able to act as suitable nonviral vectors for transferring genetic materials across cellular membranes.Methods: NDs were oxidized and functionalized by binding lysine moieties attached to a three-carbon-length linker (1,3-diaminopropane) to their surfaces through amide bonds. Raman and Fourier transform infrared spectroscopy, zeta potential measurement, dynamic light scattering, atomic force microscopic imaging, and thermogravimetric analysis were used to characterize the lysine-functionalized NDs. Finally, the ability of the functionalized diamonds to bind plasmid DNA and small interfering RNA was investigated by gel electrophoresis assay and through size and zeta potential measurements.Results: NDs were successfully functionalized with the lysine linker, producing surface loading of 1.7 mmol g(-1) of ND. These modified NDs formed highly stable aqueous dispersions with a zeta potential of 49 mV and particle size of approximately 20 nm. The functionalized NDs were found to be able to bind plasmid DNA and small interfering RNA by forming nanosized "diamoplexes".Conclusion: The lysine-substituted ND particles generated in this study exhibit stable aqueous formulations and show potential for use as carriers for genetic materials.

Comprehensive X-ray absorption near-edge structure spectroscopy at the C, O and Li K-edges and the Mn, Fe, and P L-edges of LiMn(0.75)Fe(0.25)PO(4) nanorods-graphene has been reported in great detail. Compared to that of free standing graphene and LiMn(0.75)Fe(0.25)PO(4), the intimate interaction between the nanorods and graphene via charge redistribution has been unambiguously confirmed. This interaction not only anchors the nanorods onto the graphene but also modifies its surface chemistry, both of which afford the nanorods-graphene hybrid an ultra-high rate performance in lithium ion batteries. Such knowledge is important for the understanding of hybrid nanomaterials for lithium ion batteries and allows rational design for further improvements in performance.