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In their classical work (Sammartino and Caflisch in Commun Math Phys 192(2):463–491, 1998), Caflisch and Sammartino established the inviscid limit and boundary layer expansions of vanishing viscosity solutions to the incompressible Navier–Stokes equations for analytic data on a half-space. The extension to an exterior domain faces a fundamental difficulty that the corresponding linear semigroup may not be contractive in analytic spaces as was the case on the half-space (Nguyen and Nguyen in Arch Ration Mech Anal 230(3):1103–1129, 2018). In this paper, we resolve this open problem for a much larger class of initial data. The resolution is due to the fact that it suffices to propagate solutions that are analytic only near the boundary, following the framework developed in the recent works that involve the boundary vorticity formulation, the analyticity estimates on the Green function, the adapted geodesic coordinates near a boundary, and the Sobolev-analytic iterative scheme. [ABSTRACT FROM AUTHOR]

The direct conversion of glucose to 5-(hydroxymethyl)furfural (HMF) has been considered a challenging process. In this study, we developed a new method using gadolinium(III) trifluoromethanesulfonate (Gd(OTf)3) in combination with Brønsted acidic ionic liquids as a catalytic system to search possibly more environmentally benign process. The reaction was carried out under a continuous-flow system. The one-step isomerization/dehydration of glucose to give the highest HMF with Gd(OTf)3 together with DBU-based Brønsted acidic ionic liquid in a low-cost home-built continuous system. The plausible mechanism was proposed with the Lewis acidic sites of Gd(OTf)3 for the isomerization step and DBU-based Brønsted acidic ionic liquid sites for the dehydration step. The recycling of catalytic system Gd(OTf)3/DBU-based Brønsted acidic ionic liquid in DMSO was examined. Our findings provided a safe and environmental process for the continuous conversion of glucose into HMF. The use of continuous flow for HMF synthesis ensures that the current method can be applied to the large-scale process. [ABSTRACT FROM AUTHOR]

Cervical cancer is the second most encountered cancer in pregnant patients. The 2018 International Federation of Gynecology and Obstetrics (FIGO) staging system for cervical cancer updated the staging of primary cervical carcinoma and disease process, with formal incorporation of imaging as a vital source of information in the management process to improve accuracy. Diagnosis and treatment of the pregnant population is a complex interplay of achieving adequate diagnostic information and optimal treatment while minimizing toxicity and risks to the mother and fetus. While novel imaging techniques and anticancer therapies are rapidly developed, much information on the safety and feasibility of different therapies is not yet available in the pregnant population. Therefore, managing pregnant patients with cervical cancer is complex and requires a multidisciplinary approach. [ABSTRACT FROM AUTHOR]

Pollution of waste and natural waters by antibiotics is a major health issue that induces the development of resistant pathogens. Pollutant may be removed by photocatalysis, yet classical photocatalysis is limited by the short carrier lifetime. Here, we review multicomponent photocatalysts for the synergic degradation of antibiotics. Components include metallic nanoparticles, semiconductors and adsorbents. The synergy of these components provide photocatalysts with advantages such as extended visible-light range with bandgap energy lower than 2.8 eV, improved charge transfer properties, enhanced adsorption capacity and more active reaction sites. The removal of the antibiotics, based on the decrease of the initial concentration, reaches 80–100%, but mineralization is rarely measured in reports. Proposed mechanisms for the photocatalytic degradation of antibiotics over single and multicomponent photocatalysts are discussed. [ABSTRACT FROM AUTHOR]

Lymphomatous involvement of the genitourinary system, particularly the kidneys, is commonly detected on autopsies; yet on conventional diagnostic imaging renal lymphoma is significantly underestimated and underreported, in part due to its variable imaging appearance and overlapping features with other conditions. We present a spectrum of typical and atypical appearances of renal lymphoma using multimodality imaging, while reviewing the roles of imaging in the detection, diagnosis, staging, and surveillance of patients with lymphoma. We also illustrate a breadth of benign and malignant entities with similar imaging features confounding the diagnosis of renal lymphoma, emphasizing the role of percutaneous image-guided biopsy. Understanding the spectrum of appearances of renal lymphoma and recognizing the overlapping entities will help radiologists improve diagnostic confidence and accuracy. [ABSTRACT FROM AUTHOR]

Semi-synthetic derivatives of camptothecin, a quinoline alkaloid found in the Camptotheca acuminata tree, are potent anticancer agents. Here we discovered two C. acuminata cytochrome P450 monooxygenases that catalyze regio-specific 10- and 11-oxidations of camptothecin, and demonstrated combinatorial chemoenzymatic C-H functionalizations of the camptothecin scaffold using the new enzymes to produce a suite of anticancer drugs, including topotecan (Hycamtin®) and irinotecan (Camptosar®). This work sheds new light into camptothecin metabolism, and represents greener approaches for accessing clinically relevant camptothecin derivatives. Camptothecin derivatives are precursors of potent anticancer agents, but their biosynthesis remains largely unknown. Here two cytochrome P450 monooxygenases are shown to regiospecifically oxidize camptothecin, yielding 10- and 11- hydroxylated derivatives, which are subsequently used to produce a suite of known anticancer drugs and derivatives. [ABSTRACT FROM AUTHOR]

Here, we characterized a gene expression system induced by 3-hydroxypropionic acid (3-HP) in Pseudomonas denitrificans. The system consists of a putative LysR-type transcriptional regulator (LTTR) encoded by hpdR and a LTTR-responsive promoter that positively controls the expression of hpdH, encoding 3-HP dehydrogenase in the presence of 3-HP. In the hpdH-responsive promoter region, two operators exhibiting dyad symmetry and designated O1 and O2 and centered at the −73 and −30 positions, respectively, were located upstream of the hpdH transcription start site. When either O1, O2, or both regions were mutated, the inducibility by the HpdR-3-HP complex was significantly reduced or completely removed, indicating that both sites are required for transcriptional activation. The HpdR protein and its operator sites on hpdH were highly specific for each other, and did not engage in cross-talk with another similar 3-HP-inducible system that is also present in P. denitrificans. This 3-HP-inducible promoter system should be useful in developing biosensors for 3-HP, and/or dynamic gene expression systems for metabolic engineering purposes. [ABSTRACT FROM AUTHOR]

We study the boundary layer theory for slightly viscous stationary flows forced by an imposed slip velocity at the boundary. According to the theory of Prandtl (in: International mathematical congress, Heidelberg, 1904; see Gesammelte Abhandlungen II, 1961) and Batchelor (J Fluid Mech 1:177–190, 1956), any Euler solution arising in this limit and consisting of a single “eddy” must have constant vorticity. Feynman and Lagerstrom (in: Proceedings of IX international congress on applied mechanics, 1956) gave a procedure to select the value of this vorticity by demanding a necessary condition for the existence of a periodic Prandtl boundary layer description. In the case of the disc, the choice—known to Batchelor (1956) and Wood (J Fluid Mech 2:77–87, 1957)—is explicit in terms of the slip forcing. For domains with non-constant curvature, Feynman and Lagerstrom give an approximate formula for the choice which is in fact only implicitly defined and must be determined together with the boundary layer profile. We show that this condition is also sufficient for the existence of a periodic boundary layer described by the Prandtl equations. Due to the quasilinear coupling between the solution and the selected vorticity, we devise a delicate iteration scheme coupled with a high-order energy method that captures and controls the implicit selection mechanism. [ABSTRACT FROM AUTHOR]

Bismuth vanadate, BiVO4, is a visible-light response semiconductor for photocatalysis applications such as organic pollutants degradation, oxygen production and carbon dioxide reduction. However, as a single-phase photocatalyst, BiVO4 efficiency is limited by the unpreferable recombination of the photoexcited electron (e−) and hole (h+). Thus, strategies have been designed to enhance the photocatalytic efficiency by promoting the separation of electrons and holes. This can be done by controling the morphology and crystallographic facets of BiVO4, and by building p–n junction photocatalytic systems with a combination of n-type semiconductors (BiVO4) and p-type semiconductors or a monoclinic–tetragonal heterostructure of BiVO4. In particular, a direct p–n junction photocatalytic system with tetragonal zircon-structured BiVO4 (t-z) and monoclinic scheelite-structured BiVO4 (m-s) combination has recently attracted attention. Here we review the synthesis of the monoclinic–tetragonal heterostructured BiVO4 photocatalyst (m–t BiVO4) by calcination, hydrothermal, microwave-assisted hydrothermal and solvothermal methods. m–t BiVO4 formation and the transmission phase between t-z and m-s are controlled by the calcining temperature, precursor pH, metal doping content, type of solvent, implementation of precursors and reaction conditions. We discuss m–t BiVO4 crystal structure, optical characteristics and photocatalytic principles. Successful formation of BiVO4 crystals with a m-s/t-z heterostructure is based on data from X-ray diffraction (XRD), Raman and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS). In the m–t BiVO4 heterostructure, a direct p–n junction photocatalytic system is established. When this system is exposed to visible light, the electrons in the conduction band of m-s BiVO4, a n-type semiconductor, migrate easily to the conduction band of t-z BiVO4, while the holes on valence band of t-z BiVO4, a p-type semiconductor, move to the valence band of m-s BiVO4 through an internal electric field. As a result, the e−/h+ charge carriers are spatially separated. [ABSTRACT FROM AUTHOR]

This study aims to synthesize and evaluate the photocatalytic activity of bismuth terephthalate material (Bi-BDC) synthesized by solvothermal (ST) and microwave-assisted solvothermal (MW) methods. Differences in the crystal structure and crystal shape were assessed by analytical methods such as X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectrum, X-ray photoelectron spectroscopy (XPS), N2 adsorption/desorption, Raman spectrum, and thermal gravimetric analysis (TGA). From XRD, IR, Raman, and XPS results, the fully crystallized Bi-BDC materials were achieved regardless of the preparation router. Bi-BDC-MW exhibited spherical-like morphologies, producing between stacked lamellar, while Bi-BDC-ST method exhibited a heterogeneous structure. The TGA data indicated that Bi-BDC is thermally stable up to 300 °C, suggesting the excellent thermal stability of Bi-BDC. The surface area and pore volume of Bi-BDC-MW (18 m2/g and 85 × 10−3 cm3/g) are higher than those of Bi-BDC-ST (16 m2/g and 52 × 10−3 cm3/g), which is due to its well-defined lamellar microstructure and homogeneity of the crystals. Compared to Bi-BDC-ST, Bi-BDC-MW has a higher value in the content of oxygen vacancy. Moreover, the photocatalytic efficiency of Bi-BDC-MW was significantly higher than that of Bi-BDC-ST, in which 99.44% rhodamine B (RhB) is removed after 360 min of irradiation. The improved photocatalytic efficiency of Bi-BDC-MW is ascribed to the morphology, specific surface area, and oxygen defects, which exhibited the good separation of electrons and holes, as confirmed by the photoluminescence (PL). The results should open a new approach to enhancing the photocatalytic activity of bismuth terephthalate materials. [ABSTRACT FROM AUTHOR]

Spinal osseous neoplasms are frequently encountered and can be challenging when present as solitary lesions. Familiarity with the range of benign and malignant spinal pathology can help the radiologist formulate a comprehensive differential diagnosis. This article focuses on the spectrum of extradural spinal tumors, accounting for the majority of primary spinal tumors, by comparing the epidemiology, pathophysiology, clinical presentation, and characteristic imaging appearance of these lesions. The discussion includes the commonly encountered benign lesions, such as vertebral venous vascular malformation and enostosis, as well as malignant lesions including metastases and lymphoma. The article also includes other less-encountered primary spinal tumors such as plasmacytoma, osteoid osteoma, osteoblastoma, giant cell tumor, eosinophilic granuloma, chordoma, chondrosarcoma, osteosarcoma, Ewing's sarcoma, and angiosarcoma. Familiarity with the characteristic imaging features can help the radiologist reach an accurate diagnosis and obviate the need for unnecessary invasive procedures such as biopsy and surgery. [ABSTRACT FROM AUTHOR]

The thoracic inlet is located at the crossroads between imaging of the neck and chest. It represents an important anatomic landmark, serving as the central conducting pathway for many vital structures extending from the neck into the chest and vice versa. Many important body systems are located within this region, including the enteric, respiratory, vascular, lymphatic, neurologic, and endocrine systems. A detailed examination of this region is essential when reviewing neck and thoracic imaging. This article will discuss the normal anatomic boundaries of the thoracic inlet and present an image-rich systematic discussion of the non-neoplastic pathology that can occur in this region. The neoplastic pathology of the thoracic inlet will be covered in a companion article. [ABSTRACT FROM AUTHOR]

The thoracic inlet is located at the crossroads between imaging of the neck and chest. It represents an important anatomic landmark, serving as the central conducting pathway for many vital structures extending from the neck into the chest and vice versa. Many important body systems are located within this region, including the enteric, respiratory, vascular, lymphatic, neurologic, and endocrine systems. A detailed examination of this region is essential when reviewing neck and thoracic imaging. This article will discuss the normal anatomic boundaries of the thoracic inlet and present an image-rich systematic discussion of the non-neoplastic pathology that can occur in this region. The neoplastic pathology of the thoracic inlet will be covered in a companion article. [ABSTRACT FROM AUTHOR]

In their classical work, Sammartino and Caflisch (Commun Math Phys 192(2):433-461, 1998a; Commun Math Phys 192(2):463-491, 1998b) proved the inviscid limit of the incompressible Navier-Stokes equations for well-prepared data with analytic regularity in the half-space. Their proof is based on the detailed construction of Prandtl’s boundary layer asymptotic expansions. In this paper, we give a direct proof of the inviscid limit for general analytic data without having to construct Prandtl’s boundary layer correctors. Our analysis makes use of the boundary vorticity formulation and the abstract Cauchy-Kovalevskaya theorem on analytic boundary layer function spaces that capture unbounded vorticity. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) has received much interest as a visible-light-driven photocatalyst for degrading pollutants such as organic dyes and antibiotics. However, g-C3N4 bulk activity could not meet expectations due to its rapid recombination of photogenerated electron–hole pairs and low specific surface area. In our study, melamine was thermally treated one-step in the presence of NH4Cl to produce g-C3N4 nanosheets. The characterizations of surface morphology and optical properties of all g-C3N4 samples were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrum (XPS), transmission electron microscopy (TEM), and UV–visible diffuse reflectance spectroscopy. Compared to bulk g-C3N4, g-C3N4 nanosheets demonstrated excellent photocatalytic activities, with approximately 98% RhB removal after 210 min of visible light irradiation. Furthermore, the effect of catalyst dosage, pH, and RhB concentration on the removal percentage dye of g-C3N4 nanosheets was also investigated. h+ and •O2− species were demonstrated as the key reactive species for the RhB. Besides, ECN exposed a tetracycline degradation efficiency of 80.5% under visible-light irradiation for 210 min, which is higher than BCN (60.8%). The improved photocatalytic activity of g-C3N4 nanosheets is due to the restriction of the recombination of photogenerated electrons/hole pairs, as provided by photoluminescence spectra and Nyquist plot. As a result, our research may offer an effective approach to fabricating g-C3N4 nanosheets with high photocatalytic activity and high stability for environmental decontamination. [ABSTRACT FROM AUTHOR]

The thoracic inlet is located at the crossroads between imaging of the neck and the chest. Its location is an important anatomic landmark, serving as the central conducting pathway for many vital structures extending from the neck into the chest and vice versa. Many critical body systems, including the respiratory, lymphatic, neurologic, enteric, musculoskeletal, endocrine, and vascular systems, are located within this region. Neoplasms, both benign and malignant, can arise in any of the body systems located in this area. Due to the small size of this anatomic location, pathology is easily overlooked and imagers should be aware of the imaging appearance of these neoplasms, as well as which imaging modality is the most appropriate for neoplasm evaluation. This article will present an image rich, system-based discussion of the neoplastic pathology that can occur in this region. The anatomy of the thoracic inlet and the non-neoplastic pathology of the thoracic inlet have been covered in our companion article. [ABSTRACT FROM AUTHOR]

A conceptual framework is proposed, to identify flood affected locations that should be considered in order to lessen the consequences of naturally occurring disaster. Sentinel-1 data are used to evaluate the performance of automatic Otsu's method and machine learning (ML) algorithms (Random Forest (RF), Support Vector Machine (SVM), CART, Minimum Distance (MD), K-nearest neighbour (KNN) and KD Tree KNN (KD-KNN)) to characterise flooded region. The study provided a holistic spatial assessment of flood inundation in the region due to impact of the extreme precipitation. The most adequate performance based on compound value is achieved by KNN ( C v = 2 ) followed by SVM ( C v = 2.25 ) ML model and Otsu's thresholding method ( C v = 2.5 ). The validation site results reveal that Vertical transmit and Vertical received (VV) polarization performs significantly better than Vertical transmit and Horizontal received (VH) polarization. The most accurate flood extent produced by Otsu's thresholding method (overall accuracy of 94.98%) and MD (overall accuracy of 88.98%) are used to evaluate the indicative number of individuals and buildings at risk within the study areas using Gridded Population of the World Version 4 (GPWv4), Global ML Building Footprints by Microsoft and OpenStreetMap building data. [ABSTRACT FROM AUTHOR]

Remodeling of the extracellular matrix (ECM) to facilitate invasion and metastasis is a universal hallmark of cancer progression. However, a definitive therapeutic target remains to be identified in this tissue compartment. As major modulators of ECM structure and function, matrix metalloproteinases (MMPs) are highly expressed in cancer and have been shown to support tumor progression. MMP enzymatic activity is inhibited by the tissue inhibitor of metalloproteinase (TIMP1–4) family of proteins, suggesting that TIMPs may possess anti-tumor activity. TIMP2 is a promiscuous MMP inhibitor that is ubiquitously expressed in normal tissues. In this study, we address inconsistencies in the literature regarding the role of TIMP2 in tumor progression by analyzing co-expressed genes in tumor vs. normal tissue. Utilizing data from The Cancer Genome Atlas and Genotype-Tissue expression studies, focusing on breast and lung carcinomas, we analyzed the correlation between TIMP2 expression and the transcriptome to identify a list of genes whose expression is highly correlated with TIMP2 in tumor tissues. Bioinformatic analysis of the identified gene list highlights a core of matrix and matrix-associated genes that are of interest as potential modulators of TIMP2 function, thus ECM structure, identifying potential tumor microenvironment biomarkers and/or therapeutic targets for further study. [ABSTRACT FROM AUTHOR]

The nanocomposites XFe2O4/GO with various metal sites (X = Co, Mn, and Ni) were successfully synthesized via the polymerized complex method. The XFe2O4/GO family was characterized using X-Ray diffraction analysis, scanning electron microscopy (SEM), and a vibrating sample magnetometer. We also investigated the effect of three fundamental parameters (initial concentration, dosage, and pH) on the removal of methylene blue using the response surface methodology. A high F value, very low P value (< 0.00001), a non-significant lack of fit, and the determination coefficient (R2 > 0.95) demonstrated a strong correlation between experimental and predicted values of the responses. The predicted optimal conditions for maximum removal efficiency were easily determined to adhere to the following trend for actual test experiments: MnFe2O4/GO (60.1%) < CoFe2O4/GO (80.3%) < NiFe2O4/GO (87.7%). Moreover, the adsorption behavior was well-described by the Langmuir isotherm and a pseudo-second-order kinetic model. The maximum capacity for adsorption of methylene blue onto XFe2O4/GO was found from 42.2 to 80.6 mg/g. Moreover, the XFe2O4/GO could be regenerated for several cycles without a considerable decrease in removal yield, suggesting that this highly promising XFe2O4/GO could be applied as an efficient and novel adsorbent. [ABSTRACT FROM AUTHOR]

In this study, the g-C3N4 with simultaneous isotype heterojunction and porous structure showed superior photocatalytic decomposition of tetracycline hydrochloride (TCH) under white LED light irradiation fabricated via a thermal polycondensation method using melamine and thiourea as precursors and NH4Cl as soft-template. X-ray diffraction and transmission electron microscopy demonstrated the successful fabrication of the heterojunction between two different phases of g-C3N4 metal-free semiconductor. Besides, the increase in surface area as well as the porosity of g-C3N4 isotype heterojunction compared with CN-M (the g-C3N4 was synthesized using melamine as precursor) or CN-T (the g-C3N4 was synthesized using thiourea as precursor) was confirmed through nitrogen adsorption–desorption isotherms. The improved photocatalytic degradation of TCH over CN-MT (the g-C3N4 was synthesized using melamine and thiourea as precursors and NH4Cl as soft-template) compared to CN-M and CN-T could be assigned to the visible light absorption expansion, the increase in surface area as well as the porosity and reduction of photo-generated electron–hole pair recombination. Specifically, the CN-MT-1:1 isotype heterojunction revealed the highest photocatalytic activity for TCH degradation (81.55%) within 180 min. Furthermore, this catalyst can be recycled four times, which demonstrates the potential of CN-MT as a visible light-sensitive catalyst for organic pollutant removal. [ABSTRACT FROM AUTHOR]

The effects of the substitution of V5+ with Ni2+ at the corresponding sites in BiVO4 on the crystal structures, optical properties, and photocatalytic efficiency of BiVO4 was investigated. Ni2+ cations doped at the V5+ sites in BiVO4 was confirmed by X-ray diffraction, Raman, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectra, and photoluminescence spectra. Ni-doped BiVO4 exhibited excellent degradation of crystal violet (CV) compared with the bare BiVO4. For optimal Ni2+ doping of 5%, the degradation rate of CV, which reached about 95% within 180 min of LED light irradiation, was obtained. Ni doping can introduce advantageous defect states that significantly increase the separation and diffusion efficiency of the photo-induced charge carriers, thereby boosting the photocatalytic activity of crystal structures. [ABSTRACT FROM AUTHOR]

Energy security and pollution are becoming critical issues in the context of climate change and the circular economy, calling for sustainable resources. Asteraceae species, commonly referred as the aster, daisy, composite, or sunflower family, are among the largest flowering plants with 23,000 species belonging to 1600 genera, and are a major source of biomass. Here we review botanical characteristics and applications of Asteraceae for bioenergy, remediation, nanotechnology, medicine, food and agriculture. Sunflower is the most used to produce bio-oils with a yearly production of 47 million tons. Sunflower is also used for phytoremediation of heavy metals such as cadmium, lead, uranium, and chromium. Artichoke, chicory, purple coneflower, and wormwood display medicinal potential with 27–103 bioactive compounds. Artemisia, calendula, and sunflower oil are precursors for cosmetic and perfume production. Asteraceae species exhibited high efficiencies of 90−96% for removal of remazol red, and reactive blue dyes. Asteraceae species are used for fabrication of nanoparticles, biochar, activated carbon and biocomposites. [ABSTRACT FROM AUTHOR]

Nano Fe-BTC/graphene oxide (GO) composites were successfully synthesized by hydrothermal treatment with a microwave-assisted method. Samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), N2 adsorption–desorption, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), and Ultraviolet–visible diffuse reflection spectroscopy (UV–Vis DRS). SEM image of Fe-BTC/GO-30 showed the particle size of 30–50 nm on the GO surface. From the UV–Vis diffuse reflectance spectra, it revealed that nano Fe-BTC/GO composite absorbed the wavelengths in the visible light region with a low bandgap energy of 2.2–2.45 eV. Fe-BTC/GO nanocomposites were tested for the photocatalytic degradation of reactive yellow 145 (RY-145) in aqueous solution. Fe-BTC/GO composites exhibited high photocatalytic activity. Thus, at pH of 3 and high initial concentration of 100 mg RY-145/L, removal efficiency reached the value of 98.18% after 60 min. of reaction. In comparison with Fe-BTC/GO synthesized by the solvothermal method, nano Fe-BTC/GO showed much higher RY-145 removal efficiency. Moreover, this Fe-BTC/GO-30 showed high catalytic activity stability and could be reused, opening the high potential application of this promising photo-Fenton catalyst in photocatalytic degradation of organic pollutants from aqueous solution. [ABSTRACT FROM AUTHOR]

Fe/graphene oxide and Cu–Fe/graphene oxide nanocomposite were synthesized by the atomic implantation method to study the photocatalytic degradation of dichlorodiphenyltrichloroethane (DDT). The synthesized nanocomposites were characterized by the XRD, N2 isotherms, SEM with EDX, TEM and XPS analysis. Characterization results have reported that oxides of Cu and Fe were uniformly distributed on graphene oxide and exited in the form of Cu+ and Fe2+ ions in Cu–Fe/graphene oxide nanocomposite. The high photocatalytic DDT removal efficiency 99.7% was obtained for Cu–Fe/graphene oxide under the optimal condition of 0.2 g/L catalyst, 15 mg/L H2O2 and pH 5. It was attributed to the reduction of Fe3+ to Fe2+ by Cu+ ions and –OH radicals formation. However, it was dropped to 90.4% in the recycling study by leaching of iron and without a change in phase structure and morphology. [ABSTRACT FROM AUTHOR]

The study reports a versatile, cost-efficient and ecofriendly protocol for the synthesis of biogenic silver nanoparticles (AgNPs) using the aqueous extracts of Quao Binh Chau, Stereospermum binhchauensis and Che Vang, Jasminum subtriplinerve and their application in antibacterial activity and catalysis. The AgNPs with varying morphology and physical properties have been optimized using the absorption measurements. The biogenic AgNPs have been characterized by Fourier transform infrared spectroscopy, UV–Vis spectroscopy, transmission electron microscopy, X-ray diffraction analysis, energy-dispersive X-ray spectroscopy and thermal behaviors. Stable crystalline AgNPs with average particle sizes of 20.0 nm and 8.0 nm were fabricated from aqueous extract of Quao Binh Chau and Che Vang, respectively. The phytochemicals from the extracts involved in reduction and stabilization of AgNPs are identified by FTIR spectra and thermal gravimetric analysis. Both the biosynthesized AgNPs show the potent antibacterial activity against four tested bacterial strains including Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Agrobacterium tumefaciens. High catalytic activity of the biogenic AgNPs in the degradation of toxic contaminants (4-nitrophenol and methyl orange) was observed. The antibacterial and catalytic activities are found to be size and phytochemical dependent. The antibacterial and catalytic activities of the biogenic nanoparticles would find applications in the biomedical and environmental fields. [ABSTRACT FROM AUTHOR]