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In this study, BiVO4 was successfully synthesized via the solvothermal process using a solvent mixture of ethylene glycol and water under different synthesis conditions of temperature and pH. Physicochemical properties such as crystal phase, morphology, and optical absorption of the as-synthesized BiVO4 samples were characterized by X-ray diffraction (XRD), Raman spectra, field emission scanning electron microscopy (FE-SEM), and ultraviolet–visible diffraction reflection spectroscopy (UV–vis DRS). The XRD analysis showed that different synthesis conditions of temperature and pH significantly affected the growth of monoclinic BiVO4 crystals oriented along (0 4 0) facets. Form SEM results, the synthesis conditions, including pH and temperature, have a great effect on the morphology of monoclinic structured BiVO4. As the pH value increases in the range of 0–9 and temperature increases from 80 °C to 180 °C, the morphology of BiVO4 changed from peanut-, rod-, and leaf-like shapes. The photocatalytic activities of as-synthesized BiVO4 photocatalysts were evaluated by the photodegradation of methylene blue (MB) dye under irradiation of white LED light. We have found that by using appropriate synthesis conditions (the synthesis temperature of 140 °C and the synthesis pH of 7) the BiVO4 exhibited high photocatalytic efficiency for MB degradation (about 82.30% after 180 min of irradiation). This result is due to the development of the BiVO4 crystals oriented along (0 4 0) facets with an increase in the intensity ratio of I(0 4 0)/I(1 2 1). The growth of BiVO4 crystals oriented along (0 4 0) facets may be beneficial to enhance the photocatalytic activity of monoclinic scheelite BiVO4.

Biogenic synthesis of noble metal nanoparticles is particularly interested due to the effective applications for plasmonic catalysis and bioactivity. In this work, aqueous extract of waste Nypa fruticans (NF) fruit husk was utilized to synthesize silver nanoparticles (NF-AgNPs) and gold nanoparticles (NF-AuNPs). The effected parameters on the green reduction of metallic nanoparticles (MNPs) were investigated. Under optimum conditions of concentration, temperature and time, the biosynthesized NF-AgNPs and NF-AuNPs showed spherical nanoparticles with average size of 10–15 nm and 15–20 nm, respectively. The presence of AgCl in NF-AgNPs has been demonstrated by X-ray diffraction analysis. The elemental components of all samples confirmed the presence of anions and cations come from the aqueous extract. The biosynthesized nanoparticles were evaluated bacterial activity against three bacterial strains. NF-AgNPs exhibited selective antibacterial activity against Bacillus cereus but no activity against Staphylococcus aureus and Salmonella typhimurium at all tested concentrations. The recyclable catalysis activity of the biosynthesized nanoparticles was evaluated for the reduction of nitrophenols in the presence of sodium borohydride which possessed good catalytic performance in six running numbers. Additionally, AgCl played role as a source supplying AgNPs has been demonstrated in catalytic reduction of p-nitrophenol. For study of catalytic kinetic, NF-AgNPs possessed higher rate constant in comparison with NF-AuNPs whereas TOF values of NF-AuNPs was determined to be higher than those of NF-AgNPs.

The present study describes an eco-friendly approach for the synthesis of colloidal solution of silver and gold nanoparticles (L-AgNPs and L-AuNPs) from the aqueous extract of Lactuca indica leaf. Major parameters affecting on the formation of L-AgNPs and L-AuNPs were optimized using UV–Vis analysis at absorption maximum around 423 nm and 531 nm, respectively. The plant extract as reducing and capping agents of MNPs was demonstrated by Fourier-transform infrared (FTIR) spectroscopy. The nanoscale of metals was confirmed by Transmission electron microscopy (TEM) measurements. TEM studies revealed that L-AgNPs were mostly spherical with average size of 13.5 nm and L-AuNPs possessed multi shapes with an average size of 14.5 nm. Selected area electron diffraction (SAED) analysis and X-ray diffractometer (XRD) data confirm their crystalline structure. The nanomaterials showed efficient catalysis in the degradation of 4-nitrophenol and methyl orange.

This paper develops a simple and green process of synthesizing palladium nanoclusters (PdNCs) capped on the hybrid nanocomposite based on biodegradable polysaccharides, 2-hydroxypropyl-β-cyclodextrin (HPCD) and alginate (Alg) through an ionotropic gelation mechanism. PdNCs were biosynthesized from aqueous extract of Burdock root (BR), Arctium lappa. The nanocomposite PdNCs/HPCD/Alg was characterized by techniques like UV–Vis, FTIR, EDX, FESEM, TEM, HR-TEM and TG-DTA. The crystal palladium nanoparticles were found to distribute in cluster shape with a size of 4–10 nm. EDX data showed that average amount of palladium capped on the hybrid nanocomposite was approx. 4.7% (w/w). PdNCs/HPCD/Alg exhibited highly catalytic activity for degradation of pollutants including 4-nitrophenol, methyl orange and rhodamine B in wastewater and leaching mechanism of the nanocatalyst was showed. In particular, the nanocomposite showed excellent aqueous-phase catalytic performance for free-triphenylphosphine Sonogashira cross-coupling reaction. The nanocatalyst could be efficiently reused without much compromising with its activity.

Cardiovascular diseases account for the number one cause of deaths in the world. Part of the reason for such grim statistics is our limited understanding of the underlying mechanisms causing these devastating pathologies, which is made difficult by the invasiveness of the procedures associated with their diagnosis (e.g., inserting catheters into the coronal artery to measure blood flow to the heart). Likewise, it is also difficult to design and test assistive devices without implanting them in vivo. However, with the recent advancements made in biomedical scanning technologies and computer simulations, image-based modeling (IBM) has arisen as the next logical step in the evolution of non-invasive patient-specific cardiovascular medicine. Yet, due to its novelty, it is still relatively unknown outside of the niche field. Therefore, the goal of this manuscript is to review the current state-of-the-art and the limitations of the methods used in this area of research, as well as their applications to personalized cardiovascular investigations and treatments. Specifically, the modeling of three different physics – electrophysiology, biomechanics and hemodynamics – used in the cardiovascular IBM is discussed in the context of the physiology that each one of them describes and the mechanisms of the underlying cardiac diseases that they can provide insight into. Only the “bare-bones” of the modeling approaches are discussed in order to make this introductory material more accessible to an outside observer. Additionally, the imaging methods, the aspects of the unique cardiac anatomy derived from them, and their relation to the modeling algorithms are reviewed. Finally, conclusions are drawn about the future evolution of these methods and their potential toward revolutionizing the non-invasive diagnosis, virtual design of treatments/assistive devices, and increasing our understanding of these lethal cardiovascular diseases.

This work presents a simply new method for in situ synthesis of gold nanoparticles (AuNPs) using the biodegradable polysaccharides. A novel composite of lactose/alginate (Lac/Alg) could be prepared easily through ionotropic gelation mechanism which can reduce in situ gold ions into AuNPs. Lactose plays a crucial role as a reducing reagent which are demonstrated by FTIR analysis. The crystalline structure of AuNPs with a mean size of 10 nm has been confirmed by analysis techniques. The nanocomposite powder possesses highly catalytic performance for degradation of contaminants including 4-nitrophenol, methyl orange, rhodamine 6 G and rhodamine B. The dispersion solution of AuNPs@Lac/Alg was used as an effective probe for highly selective detection of Fe3+ ions. The detection mechanism replies on the aggregation of nanocomposite in the presence of Fe3+ ions. LOD value was found to be 0.8 μM in a linear range of 2.0–80.0 μM.

Novel multi-functional nanocomposites were fabricated from polysaccharides, alginate (Alg) and β-cyclodextrin (β-CD) via the ionotropic gelation mechanism. Different procedures for capping silver nanoparticles (AgNPs) were used to synthesize the nanocomposites AgNPs@β-CD/Alg. The aqueous extract of L. indica served as a green reductant for the optimized synthesis of the AgNPs. The AgNPs were incorporated and stabilized by using different β-CD/Alg capping methods, which induced changes in their morphology. The average sizes (10–30 nm) can be controlled by different stabilization agents. The effects of the capping methods were evaluated for the catalytic activity of the degradation reaction of methyl orange. The results demonstrated that the synthetic methods induced an obvious influence on the catalytic efficiency and recyclability. It was demonstrated that the mechanism of AgNPs catalysis relied on the Langmuir–Hinshelwood model of heterogeneous catalysis. Moreover, the AgNPs-loaded nanocomposites were studied for silver release in various media and the antibacterial activity against E. coli was evaluated for all samples.

Oil extracted from spent coffee ground (SCG) has been well known as a potential feedstock for high quality biodiesel production. This work was to investigate extraction, physical and chemical characterizations of Robusta coffee oil (CO) and its application for biodiesel production. Analysis of seven coffee ground (CG) samples showed that oil content in CGs depended on technique of the manufacturer. Morphological changes of CGs surface were recorded by FESEM technique which showed the particle size significantly increased with the oil loss. Infrared spectroscopies revealed absence of SCG oil in the de-oiled SCG, confirmed that soxhlet method in hexane was used efficiently for the oil extraction. Thermal properties of SCG oil, fresh coffee ground (FCG), SCG and de-oiled SCG samples were investigated by simultaneous TG–DTA measurement. The obtained data showed the oil content relating to thermal changes of SCG samples. Comparison between chemical components of Robusta coffee bean (RCB) and SCG reflected a fact that most of oil content in the SCG could be originated in manufacturing process of FCG. Quality biodiesel product has prepared from SCG oils via a two-step process. After pre-treatment process, transesterification of SCG oils was carried out with methanol (v/v, 30%) and NaOH (w/v, 1%) in yield 89.2%.

Vibrational fingerprints of N6-methyladenine (NMA) and N6,N6-dimethyladenine (NDMA) on gold nanoparticles (AuNPs) were investigated by means of Raman spectroscopy. NMA and NDMA have one methyl group and two methyl groups, respectively, at the amino moiety of the adenine purine unit. Surface-enhanced Raman scattering (SERS) spectra were analyzed to explain the difference in the spectral features among adenine, NMA, and NDMA based on density functional theory (DFT) calculations on gold clusters. NMA has unique bands at 717 and 1101 cm−1 in their SERS spectra on AuNPs, which can be differentiated from those of adenine. After observing these unique spectra features, the SERS spectra of NMA and NDMA on AuNPs were dissimilar, suggesting that the methyl group at the amino groups of the adenine may be significantly affecting the binding on AuNPs, as supported by DFT calculations of NMA and NDMA on gold clusters. Our Raman study indicates that the methylation at the amino group in adenine may play a significant role in providing vibrational finger prints in the SERS spectra on metal surfaces.

We compared the adsorption and desorption of 1-pyrenecarboxylic acid (PyC), 1-pyreneacetic acid (PyA), and 1-pyrenebutyric acid (PyB) on silver nanoparticles (AgNPs) via interfacial spectroscopic tools to study the role of the aliphatic units between pyrene and carboxylic group. The negative surface charges of AgNPs at ca. −51 mV shifted up to −11 mV, after adsorbing hydrophobic pyrene compounds. The three pyrene acid compounds appeared to adsorb onto AgNPs via their carboxylate units by referring to the observation of the broad ν (COO − ) bands at 1380–1410 cm −1 in the Raman spectra. X-ray photoelectron spectroscopy (XPS) also supported the C O species in the C 1s region. AgNPs were found to efficiently quench the fluorescence of the three pyrene acid adsorbates. The highest Stern–Volmer constant of PyA may be due to the largest overlap integral with the surface Plasmon absorption band of AgNPs. The butyric unit was expected to lead a stronger binding on Ag, as suggested by density functional theory (DFT) calculations. The adsorbed pyrene acid compounds appeared to be released from AgNPs by thiol-containing glutathione (GSH). PyB with the butyric group exhibited larger quenched fluorescence intensities and smaller released amounts than PyC and PyA in aqueous solutions and A549 cancer cells. Our study will be helpful in designing pyrene-based fluorescence sensors in cellular imaging.

Spectral differences between cytosine (Cyt) and 5-methylcytosine (5MC) were investigated by means of Raman spectroscopy with a combination of density functional theory (DFT) calculations. Surface-enhanced Raman scattering (SERS) revealed discriminating peaks of 5MC from those of Cyt upon adsorption on gold nanoparticles (AuNPs). Among the notable features, the multiple bands between 850 and 700 cm− 1 for the ring-breathing modes of 5MC and Cyt could be correlated well with the simulated spectra based on the DFT calculations of the adsorbates on the gold cluster atoms. The relative energetic stabilities of the enol/keto and the amino/imino tautomeric forms of Cyt and 5MC have been estimated using DFT calculations, before and after binding six atom gold clusters. Among the six tautomeric forms, the 7H keto amino and the 4H imino trans forms are expected to be predominant in binding gold atoms, whereas the enol trans/cis conformers would coexist in the free gas phase. Our approach may provide useful theoretical guidelines for identifying 5MC from Cyt by analyzing Raman spectra on gold surfaces on the basis of quantum-mechanical calculations.

In this study, we investigated sulfate-modified BiVO4 with the high photocatalytic activity synthesized by a sol-gel method in the presence of thiourea, followed by the annealing process at different temperatures. Its structure was characterized by thermal gravimetric analysis (TGA), powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The BiVO4 synthesized in the presence of thiourea and calcined at 600 &deg, C (T-BVO-600) exhibited the highest photocatalytic degradation efficiency of methylene blue (MB) in water, 98.53% MB removal was achieved within 240 min. The reaction mechanisms that affect MB photocatalytic degradation on the T-BVO-600 were investigated via an indirect chemical probe method, using chemical agents to capture the active species produced during the early stages of photocatalysis, including 1,4-benzoquinone (scavenger for O2&minus, ), ethylenediaminetetraacetic acid disodium salt (scavenger for h+), and tert-butanol (scavenger for HO&bull, ). The results show that holes (h+) and hydroxyl radicals (HO&bull, ) are the dominant species of MB decomposition. Photoluminescence (PL) measurement results of terephthalic acid solutions in the presence of BiVO4 samples and BiVO4 powders confirm the involvement of hydroxyl radicals and the separation efficiency of electron-hole pairs in MB photocatalytic degradation. Besides, the T-BVO-600 exhibits good recyclability for MB removal, achieving a removal rate of above 83% after five cycles. The T-BVO-600 has the features of high efficiency and good recyclability for MB photocatalytic degradation. These results provide new insight into the purpose of improving the photocatalytic activity of BiVO4 catalyst.

Tissue engineering has the potential for repairing large bone defects, which impose a heavy financial burden on the public health. However, difficulties with O2 delivery to the cells residing in the interior of tissue engineering scaffolds make it challenging to grow artificial tissues of clinically-relevant sizes. This study uses image-based simulation in order to provide insight into how to better optimize the scaffold manufacturing parameters, and the culturing conditions, in order to resolve the O2 bottleneck. To do this, high resolution 3D X-ray images of two common scaffold types (salt leached foam and non-woven fiber mesh) are fed into Lattice Boltzmann Method fluid dynamics and reactive Lagrangian Scalar Tracking mass transfer solvers. The obtained findings indicate that the scaffolds should have maximal surface area-to-solid volume ratios for higher chances of the molecular collisions with the cells. Furthermore, the cell culture media should be flown through the scaffold pores as fast as practically possible (without detaching or killing the cells). Finally, we have provided a parametric sweep that maps how the molecular transport within the scaffolds is affected by variations in rates of O2 consumption by the cells. Ultimately, the results of this study are expected to benefit the computer-assisted design of tissue engineering scaffolds and culturing experiments.

Recently, the waste agricultural materials have been widely considerable for green synthesis of noble metallic nanoparticles (MNPs) due to cost efficiency and environmental protection. This study has presented a simple method for the preparation of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) utilizing aqueous extract of waste Passiflora edulis peel (PEP) as reducing and stabilizing agents. The formation of MNPs was optimized reaction conditions to obtain the best colloidal solutions. The characterizations of the biosynthesized MNPs were performed by analysis techniques such as Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED). The TEM data confirmed PEP-AgNPs and PEP-AuNPs in the spherical shape with mean size of 25 nm and 7 nm, respectively. The XRD and SAED patterns showed the synthesized nanoparticles existing in crystalline nature. Antibacterial and catalytic activities have been investigated for their applications. The PEP-AgNPs exhibited a strong antibacterial activity against three strains including Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The excellently catalytic activity of both the biosynthesized nanoparticles has been demonstrated for reduction of nitrophenols and degradation of toxic organic dyes via study on their kinetics.

This study presents an efficient and facile method for biosynthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) using aqueous extract of burdock root (BR), A. lappa, and their applications. The nanoparticles were characterized by ultraviolet-visible spectrophotometry, X-ray diffraction, transmission electron microscopy, energy dispersive X-ray, thermogravimetry, and differential thermal analysis. AgNPs capped the BR extract (BR-AgNPs) possessed roughly spherical geometry with an average diameter of 21.3 nm while uneven geometry of AuNPs capped the BR extract (BR-AuNPs) showed multi shapes in average size of 24.7 nm. The BR-AgNPs strongly inhibited five tested microorganism strains. In particular, the nanoparticles showed excellent catalytic activity for the conversion of pollutants within wastewater. Pseudo-first-order rate constants for the degradation of 4-nitrophenol, methyl orange, and rhodamine B were respectively found 6.77 × 10−3, 3.70 × 10−3, and 6.07 × 10−3 s−1 for BR-AgNPs and 6.87 × 10−3, 6.07 × 10−3, and 7.07 × 10−3 s−1 for BR-AuNPs.

This study presents an efficient and facile method for the trapping of Ag+ ions on hybrid nanocomposite based on 2-hydroxypropyl-β-cyclodextrin (HPCD) and alginate (Alg) in aqueous medium through ionotropic gelation mechanism and followed by in situ assembly of silver nanoparticles (AgNPs) using aqueous extract of Jasminum subtriplinerve leaves as a reducing agent. The nanocomposite AgNPs/HPCD/Alg was characterized by UV-vis, EDX, TEM, HR-TEM analysis. The AgNPs were found to be spherical shape and uniform size with an average diameter of 13.5 nm. EDX data showed about 4.0% (w/w) of AgNPs capped on the nanocomposite HPCD/Alg. The role of HPCD and Alg in the nanocomposites was observed from FTIR and thermal studies. The stability and distribution of the nanoparticles in the aqueous solution were determined by zeta potential and DLS measurements. The nanocomposites showed excellent catalytic performance for degradation of pollutants within industrial effluents including 4-nitrophenol, methyl orange and rhodamine B.

We report a facile method for sample preparation and sensitive on-site detection of melamine in powdered infant formula and chocolate using Raman spectroscopy on sharp-edged gold nanostars (AuNSs). The aggregation of AuNSs by sodium chloride (1.2 M) facilitates the more sensitive detection of melamine in comparison with spherical gold nanoparticles (AuNPs). Density functional theory quantum mechanical calculations were performed to determine the energetic stability on gold cluster atoms. Our spectroscopic data indicated that AuNSs are an efficient platform for detecting melamine in food mixtures. The detection limits of melamine in powdered infant formula and chocolate were found to be ~0.1 mg/kg and ~1 mg/kg, respectively, on AuNPs, whereas they were observed to be ~0.01 mg/kg and ~0.1 mg/kg, respectively, on AuNSs. Using a handheld Raman spectrometer, a sub-mg/kg detection of melamine in both powdered infant formula and chocolate could be achieved within a few minutes.

A surface-enhanced Raman scattering (SERS) detection method for environmental copper ions (Cu2+) was developed according to the vibrational spectral change of diethyldithiocarbamate (DDTC) on gold nanoparticles (AuNPs). The ultraviolet-visible (UV-Vis) absorption spectra indicated that DDTC formed a complex with Cu2+, showing a prominent peak at ~450 nm. We found Raman spectral changes in DDTC from ~1490 cm−1 to ~1504 cm−1 on AuNPs at a high concentration of Cu2+ above 1 μM. The other ions of Zn2+, Pb2+, Ni2+, NH4+, Mn2+, Mg2+, K+, Hg2+, Fe2+, Fe3+, Cr3+, Co2+, Cd2+, and Ca2+ did not produce such spectral changes, even after they reacted with DDTC. The electroplating industrial wastewater samples were tested under the interference of highly concentrated ions of Fe3+, Ni2+, and Zn2+. The Raman spectroscopy-based quantification of Cu2+ ions was able to be achieved for the wastewater after treatment with alkaline chlorination, whereas the cyanide-containing water did not show any spectral changes, due to the complexation of the cyanide with the Cu2+ ions. A micromolar range detection limit of Cu2+ ions could be achieved by analyzing the Raman spectra of DDTC in the cyanide-removed water.