High Concentration Range Research Articles

Assessment of Si–O Equilibria and Nonmetallic Inclusion Characteristics in High Silicon Steels

Si–O deoxidation equilibria in liquid steel are not reliably known, especially in the high silicon concentration range. Herein, Si–O deoxidation equilibria in liquid steel at 1823–1873 K have been investigated for a wide range of silicon concentrations. Thermodynamic analysis was carried out using Wagner's interaction parameter formalism (WIPF) and FactSage 8.1. The first and second‐order cross‐interaction parameters estimated at 1873 K are as follows: , , . Moreover, nonmetallic inclusion characteristics were also investigated for varying silicon concentrations.

Abstract 4352: Leveraging deep proteome profiling of plasma- and serum-derived extracellular vesicles for melanoma biomarker discovery and disease dissection

Abstract Extracellular vesicles (EV) play an important role in melanoma progression but their potential as clinical biomarkers has yet to be realized. EVs can be found in most liquid biopsies (e.g., blood, urine, CSF) and exosomes are the most prominent subcategory of EVs. Exosomes are 50-200 nm lipid-bilayer enclosed particles secreted by all body cells, including tumor cells, and serve as mediators of metastasis formation and typically contain several classes of bioactive molecules such as RNA, proteins, lipids, and metabolites. Blood and its liquid components plasma/serum are the most frequently used matrix for biomarker discovery due to the ease of collection. However, most proteomic platforms for plasma/serum profiling are unable to profile EV proteins due to the high dynamic range of protein concentrations in EV preparations. This is due to 1) EV isolation methods that vary in their potential to separate EVs from free proteins, and 2) the presence of a natural corona of high-abundant blood proteins attached to the EV surface. To tackle this challenge, we developed SEC-DIA-MS an integrated workflow combining size-exclusion chromatography, EV concentration, and optimized mass spectrometry to enable deep profiling of the proteome content of the enriched vesicles. From 200 µl of plasma or serum from a test melanoma patient cohort (6 patients and 3 matched controls), we quantified 2,242 exosome-associated proteins, achieving a 2.5-fold increase in depth compared to previous melanoma studies. To gain a better understanding of the exosome enrichment efficiency, we extensively characterized the plasma/serum proteome by analyzing native, depleted, and EV-enriched blood from the same donors. We successfully validated well-known exosome markers such as CD9, CD63, CD81, PDCD6IP, and TSG101, and found that EV samples are significantly enriched in intact membrane proteins and those related to T cell biology, further underlining the uniqueness of the EV proteome composition. We further assessed the differences between plasma and serum EVs and suggest the use of plasma samples for future studies due to better separation of healthy and melanoma samples. Furthermore, known melanoma markers such as MCAM, TNC, and TGFBI were upregulated in melanoma plasma-derived EV but not depleted plasma samples, highlighting the specific information contained in EVs. Taken together, we demonstrated the applicability and potential of an EV-based proteomic workflow for biomarker discovery in plasma and serum. The ease of automating and scaling up such an approach enables a broader application to other indications and biological matrices. Citation Format: Evelyn Lattmann, Luca Räss, Marco Tognetti, Julia Martinez Gomez, Valérie Lapaire, Roland Bruderer, Lukas Reiter, Yuehan Feng, Lars M. Steinmetz, Mitchell P. Levesque. Leveraging deep proteome profiling of plasma- and serum-derived extracellular vesicles for melanoma biomarker discovery and disease dissection. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4352.

Association between Low Blood Selenium Concentrations and Poor Hand Grip Strength in United States Adults Participating in NHANES Surveys (2011-2014).

The trace element selenium, which is found in selenoproteins, plays an antioxidant role in preventing muscle tissue injury. A positive association between selenium concentrations and hand grip strength has been reported in older adults; however, the evidence of this association is scarce in general adults. In this study, we aimed to evaluate the association between blood selenium concentrations and low hand grip strength using the data from the National Health and Nutrition Examination Survey 2011-2012 and 2013-2014 in the United States (US). Logistic regression was used to calculate the odds ratio (OR) of low hand grip strength, with blood selenium level adjusted for potential confounders. Among 8158 adults (women: 51.59%) with a mean age of 47 (range, 18-80) years, women and non-Hispanic Blacks tended to have low blood selenium concentrations. Notably, participants with high blood selenium concentrations (range, 178.1-192.5 μg/L) were more likely to have a low risk of low hand grip strength after adjusting for the potential covariates (OR: 0.60, 95% confidence interval [CI]: 0.38-0.95) than those with low blood selenium concentrations. After excluding participants with chronic diseases, high blood selenium concentrations were found to be associated with a low risk of low hand grip strength (OR: 0.30, 95% CI: 0.14-0.65). A J-shaped relationship was found between selenium concentrations and low hand grip strength (P for nonlinear trend < 0.0001). Subgroup analyses revealed a significantly consistent relationship among women, non-Hispanic Whites and others, and individuals with overweight or obesity (P < 0.05). Our study suggests that blood selenium concentrations are inversely associated with hand grip strength in general US adults.

A Miniaturized Active Dual SIW Re-Entrant Resonators for High-Resolution and Ultra-low-Limit-Concentration Detection to Glucose Solutions

Two passive re-entrant cavity resonators (RECRs) in substrate integrated waveguide (SIW) configuration are vertically stacked to implement a miniaturized dual RECRs sensor. Only one negative resistance circuit (NRC) is innovatively proposed to be connected with these two RECRs in the common stacked metal layer between them and implement an active dual RECRs sensor, and the corresponding equivalent lumped circuit mode is proposed to analyze the dielectric sensing characteristics. Then, the compensated power obtained from the NRC is simultaneously fed into these two RECRs embedded with two microfluidics, and the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> -factor of either of these two RECRs can be greatly enhanced by simply changing the bias voltages of the transistor and varactor in the NRC. Finally, the active sensor is utilized to perform high-resolution detection to glucose solutions in high concentration range from 100 to 1000 mmol/L and low concentration range from 1 to 50 mmol/L. By gradually approximating the resonant frequency self-shift noise <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta f_{\mathrm {Aself}}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta f_{\mathrm {Bself}}$ </tex-math></inline-formula> ) of the active RECR-A (RECR-B) by the resonant frequency shift <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta f_{\mathrm {s}}$ </tex-math></inline-formula> determined by glucose solutions, minimum detectable glucose concentration of 1 mmol/L is experimentally achieved. The linear relationship between the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta f_{\mathrm {s}}$ </tex-math></inline-formula> and the glucose concentration is experimentally demonstrated, and shows good potential for glucose sensing.

Detailed Experimental and In Silico Investigation of Indomethacin Binding with Human Serum Albumin Considering Primary and Secondary Binding Sites

The interaction of indomethacin with human serum albumin (HSA) has been studied here considering the primary and secondary binding sites. The Stern-Volmer plots were linear in the lower concentration range of indomethacin while a downward curvature was observed in the higher concentration range, suggesting the presence of more than one binding site for indomethacin inside HSA due to which the microenvironment of the fluorophore changed slightly and some of its fraction was not accessible to the quencher. The Stern-Volmer quenching constants (KSV) for the primary and secondary sites were calculated from the two linear portions of the Stern-Volmer plots. There was around a two-fold decrease in the quenching constants for the low-affinity site as compared to the primary binding site. The interaction takes place via a static quenching mechanism and the KSV decreases at both primary and secondary sites upon increasing the temperature. The binding constants were also evaluated, which show strong binding at the primary site and fair binding at the secondary site. The binding was thermodynamically favorable with the liberation of heat and the ordering of the system. In principle, hydrogen bonding and Van der Waals forces were involved in the binding at the primary site while the low-affinity site interacted through hydrophobic forces only. The competitive binding was also evaluated using warfarin, ibuprofen, hemin, and a warfarin + hemin combination as site markers. The binding profile remained unchanged in the presence of ibuprofen, whereas it decreased in the presence of both warfarin and hemin with a straight line in the Stern-Volmer plots. The reduction in the binding was at a maximum when both warfarin and hemin were present simultaneously with the downward curvature in the Stern-Volmer plots at higher concentrations of indomethacin. The secondary structure of HSA also changes slightly in the presence of higher concentrations of indomethacin. Molecular dynamics simulations were performed at the primary and secondary binding sites of HSA which are drug site 1 (located in the subdomain IIA of the protein) and the hemin binding site (located in subdomain IB), respectively. From the results obtained from molecular docking and MD simulation, the indomethacin molecule showed more binding affinity towards drug site 1 followed by the other two sites.

Leaching characteristics and pollution risk assessment of potentially harmful elements from coal gangue exposed to weathering for different periods of time

To explore the leaching behavior and potential degree of pollution that can result from the backfilling of goafs with different types of coal gangue (CG), fresh CG from the Hongqi Coal Mine goaf and surface CG (weathered for 1year) were selected as the research objects in this study. A series of leaching experiments were carried out using the Ordovician limestone karst waters of the mining areas as the soaking solution. A comparative study on the dissolution characteristics of Fe3+, Mn2+, and SO42- and on the traditional water quality parameters of the two types of CG was conducted. The results showed that the soaked, weathered CG displayed a higher ion dissolution value than fresh CG. The ratio of each ion was as follows: Fe3+ was 1, Mn2+ was 2.86 ~ 68.18, and SO42- was 1.34 ~ 2.09. Over time, the ion concentration of water samples that initially contained high ion concentration values showed a decreasing trend after CG was soaked in these waters, but the values were still in the range of high ion release concentrations. The pH and oxidation‒reduction potential (ORP) values of the leachate of both CG types indicated that the leachates were weakly alkaline and weakly oxidizing, and the overall change in total dissolved solids (TDS) was small and consistent with the SO42- trend. SO42- in the leachate of the weathered CG showed a more significant correlation with the pH and TDS of the soaking solution, and it was the major pollutant. According to the geoaccumulation index evaluation, weathered CG had higher pollution potential than fresh CG. Fe3+ presented a slight and moderate risk for contamination.

Source of gold and ore-forming processes in the Zarshuran gold deposit, NW Iran: Insights from in situ elemental and sulfur isotopic compositions of pyrite, fluid inclusions, and O−H isotopes

The Zarshuran gold deposit (155 t Au, average grade: 2.63 g/t), NW Iran, provides a new paradigm for understanding the multicomponent ore-forming processes and metallogeny of gold during the evolution of hydrothermal fluids. It is characterized by auriferous quartz veins and gold coexisting with disseminated Fe-As-S sulfide minerals that are hosted in a sequence of Early Cambrian metasedimentary rocks. A complex paragenesis is defined by five sulfide stages: pre-ore stage pyrite (Py0), early ore-stage pyrite (Py1 and Py2), middle ore-stage pyrite (Py3a, Py3b, and Py3c), late ore-stage pyrite (Py4), and post ore-stage pyrite (Py5). Py0 with framboidal texture is characterized by relatively low concentrations of As, Au, Cu, and Sb, and has a broad range of negative δ34S values from −28.2 to −3.7 ‰, indicating microbial reduction of marine sulfate. Py1 and Py2 show porous texture with As-rich bright bands also having high Au (mean: 18.4 ppm). Similarly, narrow ranges in δ34S from −3.6 to +3.2 ‰ likely suggest a deep-seated magmatic sulfur source. In the middle ore-stage, Py3a cryptocrystalline cores have a range of positive δ34S (+5.4 to +26.7 ‰) values and high concentration of As(-Au), whereas later well-crystallized outer rim Py3c is Co(-Ni) rich, has a much more restricted δ34S range (−2.9 to +1.4 ‰), indicating an evolution of fluid composition from As-rich to Co-rich. Most of the gold (mean: 20.2 ppm) and trace elements (Hg, Ag, Sb, and Tl) were deposited in Py4, whose δ34S values (+5.4 to +26.7 ‰) show that ore fluid sulfur in this stage was mainly sourced from a mixture of magmatic sulfur with minor input of reduced sedimentary rocks. Low gold and trace element content with slightly negative δ34S values (–8.5 to –4.2 ‰) of Py5 show that they were likely formed from a metal-poor oxidizing fluid.The mineralizing fluid system can be described as carbonic-aqueous with low to moderate salinity (3.2–15.1 wt% NaCl equiv.) and medium temperature of 285 to 317 °C (early ore-stage) and 255 to 290 °C (late ore-stage), which suggests that phase separation was responsible for gold precipitation during late ore-stage As-Hg-Sb sulfide veins. The δ18Ofluid ranges from −7.8 to +4.2 ‰, and the δD values for fluid inclusions in mineral range from −105 to −65 ‰, suggesting involvement of meteoric water during late- to post ore-stages. Our results indicate that the Zarshuran is a distal disseminated gold deposit formed during southward subduction of the Proto-Tethys oceanic lithosphere beneath the northern margin of Gondwanan terranes through the early Cambrian.

Separation of n-hexane-ethanol azeotropic mixture using choline chloride +1,4-butanediol deep eutectic solvents

For an environmentally friendly and economical separation process of ethanol from n-hexane which is hard to handle due to the azeotrope, the liquid-liquid extraction was carried out by using choline chloride (ChCl) based deep eutectic solvents (DESs) in different molar ratios with 1,4-butanediol: DES1 (ChCl:1,4-butanediol=1:3), DES2 (ChCl:1,4-butanediol=1:4), and DES3 (ChCl:1,4-butanediol=1:5). The liquid-liquid phase equilibrium was performed on the n-Hexane (1) + Ethanol (2) + DES (3) systems at 298.15 K and atmospheric pressure. The binodal curve is determined by using the turbidity method. The various physico-chemical properties such as refractive index, viscosity, and density were measured for compositions in the binodal point. The equilibrium compositions of liquid-liquid phase equilibrium were determined from the refractive index value at the binodal points, and were predicted by COSMO-SAC model. The miscibility area predicted by COSMO-SAC model became larger as the molar ratio of 1,4-butanediol in DES increased, that is, DES3 shows the most miscible area. While in the experimental results, the miscibility depending on DES-type does not show a large difference. The experimental values for PI shows the order of DES2 (ChCl:1,4-butanediol=1:4)> DES1 (ChCl:1,4-butanediol=1:3)> DES3 (ChCl:1,4-butanediol=1:5) at less 3 wt% concentration of ethanol, but at higher concentration range (>3 wt%) DES3 shows the best value. Both of DES2 and DES3 are profitable to adopt in the extraction process of ethanol from n-hexane owing to the high performance index, high distribution coefficient, and high selectivity. The experimental results show the possibility of DESs as an alternative to ionic liquids in the separation of azeotropic mixtures, taking into account the properties of DES such as low price, uncomplicated manufacturing methods, environmentally friendly, and low toxicity.

Phase-Transfer Catalyzed Microfluidic Glycosylation: A Small Change in Concentration Results in a Dramatic Increase in Stereoselectivity

Phase-transfer catalysis (PTC) is widely used in glycochemistry for the preparation of aryl glycosides by the glycosylation reaction. While investigating the possibility of synthesis of 4-(3-chloropropoxy)phenyl sialoside (Neu5Ac-OCPP) from N-acetylsialyl chloride with O-acetyl groups (1), we have recently discovered a strong dependence of the PTC glycosylation outcome on the mixing mode: under batch conditions, only α-anomer of Neu5Ac-OCPP was obtained, albeit in low yield (13%), while under microfluidic conditions the yield of Neu5Ac-OCPP increased to 36%, although stereoselectivity decreased (α/β ≤ 6.2). Here, we report that the outcome of this reaction, performed under microfluidic conditions using a Comet X-01 micromixer (at 2 μL/min flow rate), non-linearly depends on the concentration of N-acetylsialyl chloride 1 (5–200 mmol/L). The target Neu5Ac-OCPP was obtained in a noticeably higher yield (up to 66%) accompanied by enhanced stereoselectivity (α/β = 17:1–32:1) in the high concentration range (C &gt; 50 mmol/L), whereas the yield (10–36%) and especially, stereoselectivity (α/β = 0.9:1–6.2:1) were lower in the low concentration range (C ≤ 50 mmol/L). This dramatic stepwise increase in stereoselectivity above critical concentration (50 mmol/L) is apparently related to the changes in the presentation of molecules on the surface of supramers of glycosyl donor, which exist in different concentration ranges.

Partial validation of the Vcheck canine pancreatic lipase assay.

Measurement of canine pancreatic lipase immunoreactivity (cPLI) is used for diagnosing pancreatitis in dogs. Because pancreatitis can be a life-threatening disease with severe complications, an in-house cPLI test would be valuable to obtain rapid test results. The aim of this study was to evaluate a point-of-care cPLI test, Vcheck cPL. Precision, determined according to EP15, and linearity under dilution were determined and judged against preset quality goals. Results from the Vcheck cPL were compared with a previously validated cPLI ELISA, Spec cPL. In a retrospective study, cPLI results from dogs with and without acute pancreatitis, as determined by pancreatic ultrasound examination, were investigated to assess the performance of the assay in a clinical setting. Statistical analysis included the Mann-Whitney test, Chi-square test, and Passing-Bablok regression analysis with a significance level of 0.05. Precision of the assay was acceptable, with intra-, inter-, and total coefficients of variation (CV%) less than 12.1%, 6.4%, and 12.1%, respectively. Results from the linearity study indicated that the method was acceptably linear at lower concentrations but not in the high-concentration range. The method comparison study revealed that Vcheck generally measured higher concentrations compared with Spec cPL, and that the methods should not be used interchangeably. Dogs with acute pancreatitis had significantly higher cPLI concentrations compared with dogs without pancreatitis (P < 0.01), but there was a marked overlap in cPL concentrations between the two groups.

Canine, mouse, and human transient receptor potential ankyrin 1 (TRPA1) channels show different sensitivity to menthol or cold stimulation.

Transient receptor potential ankyrin 1 (TRPA1) is a nonselective cation channel that is activated by a variety of stimuli and acts as a nociceptor. Mouse and human TRPA1 exhibit different reactivity to some stimuli, including chemicals such as menthol as well as cold stimuli. The cold sensitivity of TRPA1 in mammalian species is controversial. Here, we analyzed the reactivity of heterologously expressed canine TRPA1 as well as the mouse and human orthologs to menthol or cold stimulation in Ca2+-imaging experiments. Canine and human TRPA1 exhibited a similar response to menthol, that is, activation in a concentration-dependent manner, even at the high concentration range in contrast to the mouse ortholog, which did not respond to high concentration of menthol. In addition, the response during the removal of menthol was different; mouse TRPA1-expressing cells exhibited a typical response with a rapid and clear increase in [Ca2+]i ("off-response"), whereas [Ca2+]i in human TRPA1-expressing cells was dramatically decreased by the washout of menthol and [Ca2+]i in canine TRPA1-expressing cells was slightly decreased. Finally, canine TRPA1 as well as mouse and human TRPA1 were activated by cold stimulation (below 19-20°C). The sensitivity to cold stimulation differed between these species, that is, human TRPA1 activated at higher temperatures compared with the canine and mouse orthologs. All of the above responses were suppressed by the selective TRPA1 inhibitor HC-030031. Because the concentration-dependency and "off-response" of menthol as well as the cold sensitivity were not uniform among these species, studies of canine TRPA1 might be useful for understanding the species-specific functional properties of mammalian TRPA1.

Species differences in activation of TRPA1 by resin additive-related chemicals relevant to indoor air quality.

Transient Receptor Potential Ankyrin 1 (TRPA1), which is expressed in the airways, has causative and exacerbating roles in respiratory diseases. TRPA1 is known as a target of sick building syndrome-related air pollutants, such as formaldehyde. Thus, an in vitro TRPA1 activation assay would be useful for predicting the potential risk of air pollution. In this study, we used human TRPA1 (hTRPA1)- and mouse TRPA1 (mTRPA1)-expressing cell lines to measure TRPA1 activation by the emerging indoor air pollutants 2-ethyl-1-hexanol (2-EH), a mixture of 2,2,4-trimethyl-1,3-pentanediol 1- and 3-monoisobutyrate (Texanol), and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB). The results indicated that 2-EH activated both hTRPA1 and mTRPA1 in a concentration-dependent manner, whereas TXIB did not activate hTRPA1 or mTRPA1. Texanol also activated hTRPA1 in a concentration-dependent manner. In contrast, a bell-shaped concentration-dependent curve was observed for mouse TRPA1 activation by Texanol, indicating inhibitory effects at a higher concentration range, which was also reported for menthol, a typical TRPA1 modulator. To further elucidate the mechanism underlying the species difference in TRPA1 activation by Texanol, V875G and G878V mutations were introduced into hTRPA1 and mTRPA1, respectively, which were reported to be key mutations for the inhibitory effect of menthol. These mutations switched the inhibitory effects of Texanol; thus, hTRPA1/V875G, but not mTRPA1/G878V, was inhibited at higher concentrations of Texanol. These results indicate that Texanol shares an interaction site with menthol. Overall, these findings suggest that careful interpretation is necessary when extrapolating rodent TRPA1-dependent toxicological effects to humans, especially with respect to the risk assessment of indoor air pollutants.

Novel H2S sensing mechanism derived from the formation of oligomeric sulfide capping the surface of gold nanourchins.

A gold nanourchin (AuNU) probe with a novel sensing mechanism for monitoring H2S was developed as a feasible colorimetric sensor. In this study, AuNUs that are selectively responsive to H2S were fabricated in the presence of trisodium citrate and 1,4-hydroquinone using a seed-mediated approach. Upon exposure of the AuNU solution to H2S, the hydrosulfide ions (HS-) in the solution are converted into oligomeric sulfides by 1,4-hydroquinone used as a reducing agent during the synthesis of AuNUs. The oligomeric sulfides formed in the AuNU solution upon the addition of H2S were found to coat the surface of the AuNUs, introducing a blue shift in absorption accompanied by a color change in the solution from sky blue to light green. This colorimetric alteration by the capping of oligomeric sulfides on the surface of AuNUs is unique compared to well-known color change mechanisms, such as aggregation, etching, or growth of nanoparticles. The novel H2S sensing mechanism of the AuNUs was characterized using UV-Vis spectroscopy, high-resolution transmission microscopy, X-ray photoelectron spectroscopy, surface-enhanced Raman spectroscopy, secondary ion mass spectroscopy, liquid chromatography-tandem mass spectrometry, and atom probe tomography. H2S was reliably monitored with two calibration curves comprising two sections with different slopes according to the low (0.3-15 μM) and high (15.0-300 μM) concentration range using the optimized AuNU probe, and a detection limit of 0.29 μM was obtained in tap water.

Cytotoxicity on Cancer Cells according to Average Molecular Weight of Chitosan Hydrolysates

To confirm the molecular characteristics of chitooligosaccharides (COS) derived from the hydrolysis of high molecular weight chitosan (HMWC), measuring average molecular weight (MW) using gel permeation chromatography (GPC) and their cytotoxicity was confirmed by treatment with several cancer cells. To evaluate the cytotoxicity of Chi-S according to different MW on various cancer cells, two types of chitooligosaccharide (COS) named Chi-S and COS-S were subjected in a concentration-dependent manner. It was divided into chitinous active substance (Chi-S) containing N-acetylglucosamine and chitosan oligosaccharide substance (COS-S), respectively. The average MW of Chi-S obtained by enzymatic treatment of HMWC for 24 h was confirmed to be about 2.7 kDa. Chi-S showed no cytotoxicity against all treated cancer cells. However, rather than showing cytotoxicity in immune macrophages RAW264.7, significant cell proliferation was observed. On the other hand, COS-S (average MW of approximately 7.3-kDa) obtained by enzymatic treatment of HMWC for 12 h showed significant cytotoxicity against all cancer cells including immune macrophages RAW264.7 at a high concentration range of 100 mg/mL or more. Furthermore, no significant changes were observed in breast cancer cells and normal cells treated with the control group. Therefore, based on the results, we estimate that Chi-S may be involved in indirect anticancer activity by selective or adaptive immunological activity according to the molecular characteristics. Our data will be a good guide for subsequent studies that can focus on the particular activity of molecules according to the difference between chitosan MW and the deacetylation degree (DD) of HMWC.

A two-dimensional analytical model for heavy metal contaminants transport in permeable reactive barrier.

Permeable reactive barrier (PRB) remediation technology has been widely used in the remediation of groundwater contamination. In numerical simulations, neglecting the non-uniform distribution of heavy metal contamination along the depth may lead to deviations between simulation results and reality. The distribution of heavy metals in the soil layer around a non-ferrous mining area in Hezhou, Guangxi, southern China was investigated, and it was found that the standard Gaussian function could well describe the non-uniform distribution of heavy metals in the soil layer. A two-dimensional analytical model solved by the finite element method was used to simulate the migration process of heavy metal contamination in the aquifer and PRB. The results show that the uniform distribution of contaminants along the depth ignores the dilution effect, which may underestimate the service life of the PRB and lead to an overly conservative design of the PRB. The breakthrough time of the PRB decreases with the increase of the maximum initial concentration (Cin,max) and the high concentration range (σ), and increases almost linearly with the barrier thickness (Lw). An optimal design method for PRB location and thickness is proposed, which can provide a reference for the engineering application of PRB.

Simulation of Nondilute Dendrimer Systems with the Bond Fluctuation Model.

Using the bond fluctuation model, we performed Monte Carlo simulations for solutions of generation 4 and 5 dendrimers with only an intermediate unit between the branching points at different concentrations, ranging from moderately dilute solutions to concentrated systems close to the melt behavior. This model may represent different real types of dendrimer families. We obtained the mean sizes, asphericities, displacement of units, scattering functions, radial distribution functions and structure factors. We compared the results obtained for the last two properties with much faster Monte Carlo simulations of point-like dendrimers using global potentials obtained through the study of binary interactions. The latter procedure provided good reproductions of these properties but failed in the reproduction of the scattering functions in the range of higher concentrations. In this range, the scattering function cannot be described as the product of the structure function and the form factor, because the intensity decreases when the density of the dendrimer units becomes more homogenous.

Synthesis, structure, thermal, magnetic, dielectric properties of Ce3+ doped M-type SrFe12O19 and electrochemical determination of L-cysteine

• Nanostructured Sr (1-x) Ce x Fe 12 O 19 nanoferrites were prepared by auto combustion method with dual fuel (Urea and glycine). • The dielectric properties of all the samples have been measured using LCR meter at room temperature and electrochemical studies was using by cyclic voltammetry at RT. • The XRD patterns and IR spectra confirmed the formation of hexagonal structure. • The dielectric parameters decreases while AC conductivity increases with frequency. At a particular frequency, the dielectric constant, dielectric loss real part and imaginary part of impedance increases, attain maximum, then begins to decrease with increase in composition. • The SrHF’s/GCE electrode showed impressive results including increased sensitivity, limit of detection, higher concentration range, stability, and reproducibility properties. Cerium substituted SrFe 12 O 19 with the nano composition of Sr (1-x) Ce x Fe 12 O 19 ( x = 0.00, 0.01, 0.05 and 0.09) have been prepared using auto-combustion technique with dual fuel. The PXRD images confirmed a single-phase hexagonal crystalline structure similar to a magnetoplumbhite for all samples. Fourier transform infra-red spectroscopy (FT-IR), field emission-scanning electron spectroscopy (FE-SEM), elemental mapping (EDS) were used to examine for the structure and morphology of the samples. The temperature dependent hexagonal phase formation and percentage weight loss was studied by thermogravimetric and differential thermal analysis (TG-DTA). Vibrating sample magnetometer (VSM) analysis confirmed that M-SrHF’s are hard magnetic in nature and super paramagnetic, these are measured at room temperature. It was found that, with the increase of the dopant Ce 3+ in strontium ferrites, the values of saturation magnetization (M S ), remanence magnetization (Mr), coercivity (H C ) and magnetic parameters of strontium ferrites decrease. The electrochemical behavior of the SrHF’s electrode and the electro-oxidation of L-cysteine was investigated using of cyclic voltammetry (CV). The best voltammetric response has been observed for a SrHF’s electrode in buffer solution at pH of 7.0 with an acquisition and scan rate of 50 mV s − 1 . The dielectric properties are measured in LCR meter and described based on the Maxwell–Wagner’s two layer model. The electron hopping between Sr 2+ and Sr 3+ , as well as Fe 3+ and Fe 2+ ions on B-sites, drives the conduction mechanism in these ferrites, these nano hexaferrites which shows its suitability in various technological applications.

Embryotoxicity evaluation of Gentamicin, an aminoglycoside antibiotic added to human embryo culture medium, using the zebrafish (Danio rerio) model

Infertility gives rise to a lot of social and psychological problems. At present, assisted reproductive technology (ART) is an important way to solve infertility. However, the live birth rate of in vitro fertilization and embryo transfer (IVF-ET) is less than 50 %. Medium is essential for the culture of embryos in vitro. Therefore, we want to explore whether the composition of the culture medium affects the survival rate of embryos. Gentamicin (GM) is an aminoglycoside antibiotic that is used to treat various bacterial infections. It is widely used in IVF medium, but it is not known whether it has a toxicity effect on embryonic development. Here, we used zebrafish embryos to investigate the embryotoxicity of GM which is an ingredient in culture medium. Our results found that there was no significant effect on the zebrafish embryo development, including survival rate, malformation rate and developmental time course, while zebrafish embryos were treated with GM at the culture medium concentration (10 mg/L, 17.8 μM) compared with the control group. To research the potential embryotoxicity of GM, we treated zebrafish embryos with GM with high concentration (range from 17.8 μM to 3000 μM). The results showed that the lethal concentration of 50 % (LC50) at 48-h post-fertilization (hpf) value of zebrafish embryos for GM was 1150 μM; the survival rate and malformation rate of zebrafish embryos were significantly changed in a dose-dependent manner. Furthermore, transcriptomics, metabolomics and epigenomics (m6A-MeRIP-seq) were used to investigate the molecular mechanism of embryotoxicity, and results showed cell cycle, dorso-ventral axis formation and collecting duct acid secretion pathway were altered significantly in treated embryos. In conclusion, there are no adverse effects on embryonic development with the working concentration of GM in human culture medium, suggesting that GM is safe for embryo culture at working concentration.

Fast chromatography of pulse triacylglycerols

AbstractA short 10‐min ultra high performance liquid chromatography (UHPLC) method was used for separation and lipidomic analysis of triacylglycerols (TAGs) in 10 pulses: baby lima beans, black beans, black‐eyed peas, butter beans, cranberry beans, garbanzo beans, green split peas, lentils, navy beans, and pinto beans. The lipids extracted using chloroform/methanol averaged 1.9–2.7% across all pulses except garbanzo beans, which gave 6.2% lipids. TAGs were analyzed using dual parallel mass spectrometry (LC1MS2), areas were integrated using LipidSearch 4.2 software, and percent relative TAG compositions were calculated. Fatty acid response factors were calculated by comparison to calibrated GC‐FID, which were used to calculate response‐factor adjusted TAG compositions. Principal component analysis revealed that the pulses separated into three clusters, which were further highlighted using hierarchical cluster analysis. A subset of TAGs was quantified using calibration curves made from alternating sets of regioisomers in the non‐linear high concentration range (~2.5 nMol/ml to ~300 nMol/ml). A linear calibration curve for the sum of tocopherols detected by fluorescence was constructed with a coefficient of determination, r2, &gt;0.99 for low concentrations (0.50–50 μg/ml), but tocopherols in pulses appeared to be inefficiently extracted. TAG regioisomers were quantified based on a Critical Ratio (CR), [AA]+/[AB]+, interpolated between the CRs of two pure regioisomer standards taken from alternating calibration standards. TAG mole percent relative compositions are reported for the first time for most pulses and the compositions are given with more detail and specificity than previously reported.

A stable and humidity resistant NH3 sensor based on luminous CsPbBr3 perovskite nanocrystals

Recent years, sensors based on perovskite nanomaterials have become one of the most interesting fields while their instability remains as one of the major obstacles for further advancement. In this work, for the first time, a facile and controllable strategy was proposed for in-situ growth of stable CsPbBr3 nanocrystals in SiO2 network on poly (vinylidene fluoride) membrane. The formation of SiO2 network was triggered by the fast hydrolysis of (3-aminopropyl)triethoxysilane as the precursor. Characterization results including UV–vis, FTIR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate successful formation of CsPbBr3–SiO2 nanocomposites. With the protection from SiO2 network, the fluorescence intensity of CsPbBr3 nanocrystals maintains 88.11% of initial intensity after 104 days in ambient environment and is stable during the humidity test (RH = 90%, for 30 min). CsPbBr3–SiO2 nanocomposite based membrane can be applied as fluorescent sensors for NH3 determination in high concentration range based on fluorescence quenching, which shows good linearity, accuracy, precision, and specificity toward NH3 over common organic vapors.