32 research outputs found

    Toward greener synthesis of gold nanomaterials: from biological to biomimetic synthesis

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    In the past two decades, the use of biomolecules, either from biological or biomimetic systems (or so-called biological or biomimetic synthesis), has emerged as a promising green approach to synthesize gold nanomaterials (Au NMs). Here, we describe recent progress on the biological and biomimetic syntheses of Au NMs. We focus our discussions on the selection principles of biomolecules, synthesis mechanisms involving biomolecules, recent evolution from biological to biomimetic synthesis, and the contributions of bioinspired synthesis to green production of Au NMs. We hope this review will provide a guideline for the green synthesis of Au NMs and other metal NMs, further paving their way toward practical applications in the field of biomedicine

    Effectiveness of the Endplate Reduction Technique Combined With Bone Grafting for the Treatment of Thoracolumbar Fractures by Using Posterior Short-Segment Fixation

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    Objective This study aimed to examine the effect of the endplate reduction (EPR) technique combined with bone grafting for treating thoracolumbar burst fractures using posterior short-segmental fixation. Methods Patients with thoracolumbar fractures admitted between January 2018 and October 2021 were retrospectively analyzed, and those meeting the criteria were assigned to the EPR group and the intermediate screws (IS) group. The vertebral wedge angle (VWA), Cobb angle (CA), anterior vertebral body height (AVBH), middle vertebral body height (MVBH), upper endplate line (UEPL), upper intervertebral angle (UIVA), and upper intervertebral disc height (UIDH) indices were examined and compared preoperatively, first day postoperatively, as well as at 12 months postoperatively. Results The result indicated that the EPR group achieved better MVBH reduction (p<0.001), UEPL reduction (p<0.001), vertebral body fracture healing (p=0.006), as well as implant breakage (p=0.04) than the IS group; VWA (p<0.001), CA (p=0.005), AVBH (p<0.001), MVBH (p<0.001), UEPL (p<0.001), and UIDH (p<0.001) were lost after reduction less than those in the IS group. There was no significant difference in operative time (p=0.315) and intraoperative bleeding (p=0.274) between the 2 groups. Conclusion The EPR group achieved better results in repositioning and maintaining MVBH and endplate morphology, with less correction loss after the reduction of the VWA, CA, AVBH, and endplate morphology. The EPR group exhibited a better healing pattern after vertebral fracture and disc degeneration was better relieved

    Absorbable Organic Halide (AOX) Reduction in Elemental Chlorine-Free (ECF) Bleaching of Bagasse Pulp from the Addition of Sodium Sulphide

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    A laboratory investigation was developed to confirm and to quantify the reductions in absorbable organic halide (AOX) discharge when sodium sulphide was added during elemental chlorine-free (ECF) bleaching of sugarcane bagasse pulp. After the chlorine dioxide bleaching stage, the pulp was sent directly into the extraction stage without washing. FTIR was employed to determine the breakage of chemical bonds in the pulp, and GC-MS was used to measure the composition of the bleaching effluent. The addition of sodium sulphide caused a reduction in AOX of up to 46.7%. The AOX reduction reached this maximum when the sodium sulphide was added 30 min after the start of the extraction stage and when the pH was higher than 12. FTIR spectroscopy showed that the phenolic lignin of the pulp was degraded by the sodium sulphide and that the syringyl lignin and C-O-C, C=O structure of the pulp holocellulose of the pulp was preserved during the extraction stage. The GC-MS showed that the chlorobenzene and chlorophenol contents decreased noticeably after the addition of sodium sulphide

    Conversion of Glucose into HMF Catalyzed by CPL-LiCl Investigated using Dual-Wavelength UV Spectrophotometry

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    The process of dehydration of glucose to 5-hydroxymethylfurfural (HMF), using caprolactam-lithium chloride (CPL/LiCl) as a solvent, was investigated. Dual-wavelength ultraviolet spectrophotometry provides a new approach for the determination of glucose conversion rate and yield of HMF. Experiments were performed to demonstrate the accuracy and precision of this method. Various reaction parameters, such as the ratio of ionic liquid, reaction temperature, reaction time, catalyst dosage, and solid absorbent, were investigated in detail for the dehydration of glucose. The optimal conditions were explored. Finally, a possible mechanism for the dehydration of fructose to HMF was proposed

    SGPNet: A Three-Dimensional Multitask Residual Framework for Segmentation and IDH Genotype Prediction of Gliomas

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    Glioma is the main type of malignant brain tumor in adults, and the status of isocitrate dehydrogenase (IDH) mutation highly affects the diagnosis, treatment, and prognosis of gliomas. Radiographic medical imaging provides a noninvasive platform for sampling both inter and intralesion heterogeneity of gliomas, and previous research has shown that the IDH genotype can be predicted from the fusion of multimodality radiology images. The features of medical images and IDH genotype are vital for medical treatment; however, it still lacks a multitask framework for the segmentation of the lesion areas of gliomas and the prediction of IDH genotype. In this paper, we propose a novel three-dimensional (3D) multitask deep learning model for segmentation and genotype prediction (SGPNet). The residual units are also introduced into the SGPNet that allows the output blocks to extract hierarchical features for different tasks and facilitate the information propagation. Our model reduces 26.6% classification error rates comparing with previous models on the datasets of Multimodal Brain Tumor Segmentation Challenge (BRATS) 2020 and The Cancer Genome Atlas (TCGA) gliomas’ databases. Furthermore, we first practically investigate the influence of lesion areas on the performance of IDH genotype prediction by setting different groups of learning targets. The experimental results indicate that the information of lesion areas is more important for the IDH genotype prediction. Our framework is effective and generalizable, which can serve as a highly automated tool to be applied in clinical decision making

    Efficient Separation and Recovery of Petroleum Hydrocarbon from Oily Sludge by a Combination of Adsorption and Demulsification

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    The treatment of oily sludge (OS) can not only effectively solve environmental pollution but also contribute to the efficient use of energy. In this study, the separation effect of OS was analyzed through sodium lignosulfonate (SL)-assisted sodium persulfate (S/D) treatment. The effects of SL concentration, pH, temperature, solid&ndash;liquid ratio, revolving speed, and time on SL adsorption solubilization were analyzed. The effects of sodium persulfate dosage, demulsification temperature, and demulsification time on sodium persulfate oxidative demulsification were analyzed. The oil removal efficiency was as high as 91.28%. The results showed that the sediment was uniformly and finely distributed in the S/D-treated OS. The contact angle of the sediment surface was 40&deg;, and the initial apparent viscosity of the OS was 56 Pa&middot;s. First, the saturated hydrocarbons and aromatic hydrocarbons on the sediment surface were adsorbed by the monolayer adsorption on SL. Stubborn, cohesive oil agglomerates were dissociated. Sulfate radical anion (SO4&minus;&middot;) with a high oxidation potential, was formed from sodium persulfate. The oxidation reaction occurred between SO4&minus;&middot; and polycyclic aromatic hydrocarbons. A good three-phase separation effect was attained. The oil recovery reached 89.65%. This provides theoretical support for the efficient clean separation of oily sludge

    Differential Studies on the Structure of Lignin–Carbohydrate Complexes (LCC) in Alkali-Extracted Plant Hemicelluloses

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    Hemicellulose extracted by alkali treatment is of interest because of the advantages of its intact sugar structure and high degree of polymerization. However, the hemicellulose extracted by alkali treatment contained more lignin fragments and the presence of a lignin–carbohydrate complex (LCC), which affected the isolation and purification of hemicellulose and its comprehensive utilization. Therefore, the evaluation of the LCC structure of different types of lignocellulosic resources is of great significance. In this study, the LCC structures of hardwoods and Gramineae were enriched in alkaline systems. Information on the composition, structural proportions, and connection patterns of LCC samples was discussed. The similarities and differences between the LCC structures of different units of raw materials were comparatively studied. The results indicated that the monosaccharide fractions were higher in the LCC of Gramineae compared to hardwoods. The composition of the lignin fraction was dominated by G and S units. The phenyl glycosidic (PhGlc) bond is the predominant LCC linkage under alkali-stabilized conditions. In addition, Gramineae PhGlc types are more numerous compared to hardwoods. The results of the study provide insights into the differences in the chemical composition and structural features of LCC in different plants and provide important guidance for the optimization of the process of purifying hemicellulose

    Optimum Conditions for the Removal of Cr(VI) using Modified Eucalyptus Bark

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    The aims of this study were response surface modeling and optimization of Cr(VI) removal from solution using formaldehyde-modified eucalyptus bark. A high removal rate of Cr(VI) was achieved under the conditions of low adsorbent dosing quantity and high initial concentration of Cr(VI). Analysis of variance showed a high multiple coefficient of determination (R2=0.9875), adjusted determination coefficient (R2Adj=0.9714), and the good second order regression equation. The initial concentration of Cr(VI) was 40.15 mg/L, adsorbent dosing quantity 3.40 g/L, and initial reaction pH 2.78, and the largest removal rate was 99.998% under the optimum reaction conditions. Langmuir and Freundlich isothermal models described well adsorption of Cr(VI) by the modified stringy bark. Adsorption kinetics studies showed that the adsorption was controlled by multiple factors, dominated by chemical adsorption. The adsorption was found to be spontaneous and endothermic, with △G0 0, and △S0 > 0. Adsorption of Cr(VI) by formaldehyde-modified stringy bark was partly controlled by REDOX reactions. The adsorbents were characterized by SEM and FTIR

    Effects of Additives on Absorbable Organic Halide Reduction in Elemental Chlorine-Free Bleaching of Bagasse Kraft Pulp

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    In order to further reduce absorbable organic halide (AOX) formation in the bleaching effluent, NH2SO3H and DMSO were added during the elemental chlorine-free (ECF) bleaching (D0EpD1) of bagasse kraft pulp. In the D0 stage, AOX formation decreased by 10% with 0.1% NH2SO3H, and a reduction of 11.2% with 1.0% DMSO, respectively. Ultraviolet (UV) spectra, Fourier transform infrared spectroscopy (FTIR), and gas chromatography-mass spectroscopy (GC-MS) were adopted in characterizing changes of lignin degradation and the main functional groups of bleached pulp. The UV spectrum showed that the quantity of polyphenols decreased after adding the additives. The FTIR spectrum showed that both the content of phenolic-type lignin and the degradation degree of lilac-type lignin decreased after adding NH2SO3H. If was found that DMSO was beneficial in retaining C-O-C and C=O structures in cellulose and hemicellulose, while NH2SO3H decreased the content of β-glycosidic bonds and C-O-C structures in cellulose and hemicellulose. The composition of lignin degradation products in the bleaching effluent was analyzed by GC-MS. The contents of chlorobenzene and chlorophenol decreased notably when additives were added. Compared with DMSO, NH2SO3H exhibited poor inhibition on the formation of some phenols
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