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•PCA degradation was enhanced by pyrite in persulfate solution.•The mechanism of the generation of reactive oxygen species (ROS) was explored.•The role of the ROS for the degradation ...of PCA was elucidated.•Superoxide radical generated from oxygen could transfer into sulfate radical.•Sulfate radical, hydroxyl radical and sulfite radical were detected by EPR.
In recent years, persulfate activation systems have received increasing attention due to their high oxidation reactivity when removing environmental pollutants. Pyrite, the most common metal sulfide on Earth’s surface, can supply abundant Fe2+ for persulfate activation. The role of the generated reactive oxygen species (ROS) in persulfate-pyrite systems however, is not fully understood. In this study, batch experiments were used to investigate p-chloroaniline (PCA) degradation by a pyrite-persulfate system. The effects of pyrite dosage, pH, temperature, air conditions (aerobic vs. anaerobic) and pyrite particle size on PCA degradation were examined. Radical detection was conducted using electron paramagnetic resonance (EPR) methods. Results from the EPR spectra indicated that PCA degradation was achieved by sulfate radical and hydroxyl radical oxidation. Aerobic conditions were more beneficial to PCA degradation than anaerobic conditions due to the generated superoxide radicals (O2−) that activated the persulfate to produce more sulfate radicals (SO4−). PCA degradation also increased with higher pyrite doses and under acidic conditions (pH 3.0 and 5.0). PCA was removed completely at pH 3.0 after 60min. Temperature increase from 10 to 50°C significantly promoted PCA degradation. These findings provide new understanding of the mechanism involved in pyrite activation of persulfate which can be used to improve PCA degradation by pyrite-persulfate systems.
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•PCA was efficiently degraded by pyrite in aqueous solutions.•Hydroxide radical plays a key role in the degradation of PCA in pyrite system.•Superoxide radical generated by pyrite was ...beneficial for producing more H2O2.•The presence of dissolved oxygen increased the PCA degradation ratio.•The acid pH is more favorable on generation of H2O2 by pyrite in aqueous solutions.
The degradation of p-chloroaniline (PCA) in aqueous solution by pyrite was studied. The effects of different parameters such as pyrite particle size, pH and pyrite dosages on the degradation of PCA were examined in batch experiments. The rate of PCA degradation increased with increased pyrite dosage and with decreased pyrite particle size from 20 to 200 mesh in aqueous solutions. Results showed that PCA degradation accelerated with lowering initial pH. In addition, the efficacy of PCA degradation by pyrite was higher with oxygen presence as compared to without oxygen. The role of reactive oxygen species (ROS) produced by pyrite in the system was also investigated. In particular, superoxide radical (O2−) produced by pyrite was instrumental in producing more H2O2, which favored the degradation reaction. The results of this study give new insights into the mechanism of the reactivity of pyrite toward environmental contaminants.
Dynamic hydrogel systems from N,O‐carboxymethyl chitosan (NOCC) are investigated in the past years, which has facilitated their widespread use in many biomedical engineering applications. However, ...the influence of the polymer's oxidation levels on the hydrogel biological properties is not fully investigated. In this study, chitosan is converted into NOCC and introduced to react spontaneously with oxidized xanthan gum (OXG) to form several injectable hydrogels with controlled degradability. Different oxidation levels of xanthan gum, as well as NOCC/OXG volume ratios, are trialed. The infrared spectroscopy spectra verify chemical modification on OXG and successful crosslinking. With increasing oxidation levels, more dialdehyde groups are introduced into the OXG, resulting in changes in physical properties including gelation, swelling, and self‐healing efficiency. Under different volume ratios, the hydrogel shows a stable structure and rigidity with higher mechanical properties, and a slower degradation rate. The shear‐thinning and self‐healing properties of the hydrogels are confirmed. In vitro assays with L929 cells show the biocompatibility of all formulations although the use of a high amount of OXG15 and OXG25 limited the cell proliferation capacity. Findings in this study suggested a suitable amount of OXG at different oxidation levels in NOCC hydrogel systems for tissue engineering applications.
The relationships between polymer modifications to the hydrogel's biological properties are essential to understand in developing a new hydrogel product. This work studies a hydrogel system consideration of the component's oxidation levels for potential use in tissue engineering applications. At different oxidation levels, hydrogels owned their characteristic properties. This suggests a suitable amount of oxidized xanthan gum used in hydrogels.
The advent of three-dimensional (3D) bioprinting offers a feasible approach to construct complex structures for soft tissue regeneration. Carboxymethyl cellulose (CMC) has been emerging as a very ...promising biomaterial for 3D bioprinting. However, due to the inability to maintain the post-printed stability, CMC needs to be physically blended and/or chemically crosslinked with other polymers. In this context, this study presents the combination of CMC with xanthan gum (XG) and hyaluronic acid (HA) to formulate a multicomponent bioink, leveraging the printability of CMC and XG, as well as the cellular support properties of HA. The ionic crosslinking of printed constructs with iron(
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the metal-ion coordination between ferric cations and carboxylate groups of the three polymers was introduced to induce improved mechanical strength and long-term stability. Moreover, immortalized human epidermal keratinocytes (HaCaT) and human foreskin fibroblasts (HFF) encapsulated within iron-crosslinked printed hydrogels exhibited excellent cell viability (more than 95%) and preserved morphology. Overall, the presented study highlights that the combination of these three biopolymers and the ionic crosslinking with ferric ions is a valuable strategy to be considered for the development of new and advanced hydrogel-based bioinks for soft tissue engineering applications.
A new hybrid crosslinked bioink for soft tissue engineering has been developed by combining carboxymethyl cellulose, xanthan gum and hyaluronic acid incorporating ferric-ion coordination with the carboxylate groups of these three polysaccharides.
Cassaine diterpenoids amides from the stem bark of Vietnamese
Oliver were screened for their cytotoxic activity against human cancer cells. The cell proliferation assay results showed that, among the ...active compounds, 3β-acetyl-nor-erythrophlamide (3AEP) exhibited the most potential cytotoxicity against human leukemia HL-60 and KG cells with IC
values of 12.0 ± 1.2 and 18.1 ± 2.7 µM, respectively. Treatment of 3AEP resulted in the apoptosis of HL-60 cells via the activation of caspase 3, and poly (ADP-ribose) polymerase (PARP). Molecular docking in silico results showed that the 3AEP can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of -7.51 and -9.63 kcal/mol respectively. These results indicated that the stem bark of Vietnamese
and its cassaine diterpenoid amides may be useful in the apoptosis induction of human leukemia cancer cells.
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Cassaine diterpenoids as erythrofordins A-C (1–3), pseudo-erythrosuamin (4), and erythrofordin U (5) isolated from the leaves of Vietnamese Erythrophleum fordii Oliver were tested ...cytotoxic activity against human leukemia cancer cells. The results showed that these metabolites exhibited dose-dependent cytotoxicity against human leukemia HL-60 and KG cells with IC50 values ranging from 15.2 ± 1.5 to 42.2 ± 3.6 µM. Treatment with erythrofordin B led to the apoptosis of HL-60 and KG cells due to the activation of caspase 3, caspase 9, and poly (ADP-ribose) polymerase (PARP). Erythrofordin B significantly increased Bak protein expression, but downregulated the anti-apoptotic protein Bcl-2, in HL-60 cells. In silico results demonstrated that erythrofordin B can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of −7.36 and −10.76 kcal/mol, respectively. These results indicated that the leaves of Vietnamese E. fordii, which contain cassaine diterpenoids, can induce the apoptosis of human leukemia cancer cells.
ObjectivesTo aid in selecting the optimal artificial intelligence (AI) solution for clinical application, we directly compared performances of selected representative custom-trained or commercial ...classification, detection and segmentation models for fracture detection on musculoskeletal radiographs of the distal radius by aligning their outputs.Design and settingThis single-centre retrospective study was conducted on a random subset of emergency department radiographs from 2008 to 2018 of the distal radius in Germany.Materials and methodsAn image set was created to be compatible with training and testing classification and segmentation models by annotating examinations for fractures and overlaying fracture masks, if applicable. Representative classification and segmentation models were trained on 80% of the data. After output binarisation, their derived fracture detection performances as well as that of a standard commercially available solution were compared on the remaining X-rays (20%) using mainly accuracy and area under the receiver operating characteristic (AUROC).ResultsA total of 2856 examinations with 712 (24.9%) fractures were included in the analysis. Accuracies reached up to 0.97 for the classification model, 0.94 for the segmentation model and 0.95 for BoneView. Cohen’s kappa was at least 0.80 in pairwise comparisons, while Fleiss’ kappa was 0.83 for all models. Fracture predictions were visualised with all three methods at different levels of detail, ranking from downsampled image region for classification over bounding box for detection to single pixel-level delineation for segmentation.ConclusionsAll three investigated approaches reached high performances for detection of distal radius fractures with simple preprocessing and postprocessing protocols on the custom-trained models. Despite their underlying structural differences, selection of one’s fracture analysis AI tool in the frame of this study reduces to the desired flavour of automation: automated classification, AI-assisted manual fracture reading or minimised false negatives.
PurposeThis study aims to integrate predictions from clinical psychology and UPPS impulsivity with the theory of planned behaviors (TPB) to draw a conceptual framework and test the prediction that ...attention deficit hyperactivity disorder (ADHD) symptoms, impulsivity would contribute to the prediction of the reasoned cognitive process of entrepreneurship over and above key predictors from an extended TPB model.Design/methodology/approachThis study utilized a sample of 2,482 students from 14 universities/institutes in Vietnam; confirmatory factor analysis was employed to test the validity and reliability. Then, regression analysis with PROCESS macro approach (5,000 bootstrap sample and 95% confidence interval) was employed to estimate the association paths and multiple mediators.FindingsThe study reveals that ADHD symptoms and impulsivity substantially contribute to the exploration of an entrepreneurial intention throughout TPB predictors, with those higher in ADHD symptoms and impulsivity having higher intentions to engage in business venturing. Moreover, UPPS impulsiveness might valuably be incorporated with TPB predictors while predicting behaviors that are often examined as the process of rational cognitive strategies business venturing.Practical implicationsThis study showed that a start-up business can be seen as a career choice for students who exhibit extensive ADHD symptoms to use their talents effectively, thus contributing to creating value for society and improving personal well-being.Originality/valueThis article stood to make contributions to entrepreneurship literature by investigating the effects of ADHD symptoms, four impulsivity traits on an entrepreneurial intention via three precursors in TPB, including attitude toward entrepreneurship, subjective norms and perceived behavioral control.
Geometric morphometrics has become an important approach in insect morphology studies because it capitalizes on advanced quantitative methods to analyze shape. Shape could be digitized as a set of ...landmarks from specimen images. However, the existing tools mostly require manual landmark digitization, and previous works on automatic landmark detection methods do not focus on implementation for end-users. Motivated by that, we propose a novel approach for automatic landmark detection, based on visual features of landmarks and keypoint matching techniques. While still archiving comparable accuracy to that of the state-of-the-art method, our framework requires less initial annotated data to build prediction model and runs faster. It is lightweight also in terms of implementation, in which a four-step workflow is provided with user-friendly graphical interfaces to produce correct landmark coordinates both by model prediction and manual correction. The utility iMorph is freely available at https://github.com/ha-usth/InsectWingLandmark, currently supporting Windows, MacOS, and Linux.
This research aims to create innovative compounds that incorporate 1,2,4‐triazole and exhibit α‐glucosidase inhibitory potential. Similar to our previously reported series of N‐aryl ...2‐{5‐(naphthalen‐1‐ylmethyl)‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐ylthio}acetamide compounds, we explore here 4‐ethyl instead of 4‐phenyl as substituent. The synthesis process effectively yielded these compounds, with the highest yield reaching up to 91 % for compound N‐phenyl‐2‐{5‐(naphthalen‐1‐ylmethyl)‐4‐ethyl‐4H‐1,2,4‐triazol‐3‐ylthio}acetamide 5 a. Their structures were validated through various spectroscopic techniques such as IR, 1H‐NMR, 13C‐NMR, and HR‐MS spectra, and for compounds 3, 5 d, and 5 e by X‐ray diffraction. In vitro experiments revealed that only compound 5 g, marked by a 3‐hydroxy substitution on the N‐phenylacetamide moiety, demonstrated higher α‐glucosidase inhibitory potential (IC50=158.4±3.4 μM) compared to the positive control, acarbose (IC50=351.3±1.8 μM). Molecular docking studies also coincide with in vitro assay by uncovering a strong hydrogen bond with residue Asp1526 along with other hydrophobic interactions of compound 5 g in the α‐glucosidase binding pocket. Compound 5 g showed a free binding energy of −9.7 kcal/mol, contrasting with acarbose (−8.0 kcal/mol). Despite the modest biological activity, this research underscores the simplicity and convenience of the procedure for synthesizing 1,2,4‐triazole‐based compounds, and contributes a key feature to the structure‐activity relationship of the triazole scaffold in the α‐glucosidase pocket.
Developed innovative compounds by integrating 1,2,4‐triazole with a focus on α‐glucosidase inhibition. The structures of these compounds were confirmed using various spectroscopic methods, including FT‐IR, 1H‐NMR, 13C‐NMR, and HR‐MS. X‐ray diffraction was used to validate structures for three specific compounds (3, 5 d, and 5 e). In vitro testing showcased the α‐glucosidase inhibitory potential, notably compound 5 g with a 3‐hydroxy substitution. Molecular docking studies were used to analyze compound interactions at the active site of the enzyme.
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