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Berberine (BBR) is a plant-origin quaternary isoquinoline alkaloid presenting exogenous cholesterol lowering and anti-hyperlipidemia therapeutic effects. The aim of this study was to ...design and generate BBR-loaded proliposomes (PLs) as solid templates for high-dose liposomes and consequently, to enhance the oral bioavailability and therapeutic effect of BBR. An air-suspension coating (layering) method was used for generating BBR-loaded PLs. The size, distribution size, morphology, and entrapment efficiency (EE) of the final reconstituted liposomes were assessed. The oral bioavailability and endogenous cholesterol lowering effects of BBR loaded in liposomes were investigated in rats and mice, respectively. The BBR-loaded PLs showed a smooth BBR-embedded film around micron-scale carrier particles (mannitol). The reconstituted BBR-loaded liposomes had a nano-scale average size (116.6 ± 5.8 nm), narrow size distribution (polydispersity index, PDI 0.269 ± 0.038), and high EE (87.8 ± 1.0%). The oral bioavailability of reconstituted BBR-loaded liposomes at a dose of 100 mg/kg in rats was increased even 628% compared to that obtained with pure BBR (according to 90% confidence interval). The BBR-loaded liposomes at the daily oral dose 100 mg/kg in P-407- reduced total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C) in hyperlipidemic mice by 15.8%, 38.2%, and 57.0%, respectively.
It is generally understood that the chemical enhancement process is essential in surface-enhanced Raman scattering (SERS) of semiconductor-based substrates. Understanding the chemical enhancement ...mechanism is one of the most significant issues in improving the SERS activity of semiconductor substrates and designed hybrid substrates. Nevertheless, understanding the chemical enhancement process, on the other hand, remains controversial and elusive. In this study, ZnO semiconductor microstructures are prepared to investigate SERS activities in probing methylene blue (MB). The SERS mechanism is well elucidated based on the chemical enhancement mechanism related to both the formation of charge-transfer band and charge transfer from the second ionization of the oxygen vacancy defect (Vo••) to lowest unoccupied molecular orbital (LUMO) of MB. Remarkably, the charge-transfer band was evidenced by examining the ground state absorption spectra with a large band centred at 600 nm. These explanations are consistent with the strong SERS substrate behaviour of ZnO microstructures, with the SERS enhancement factor (EF) of ZnO plate substrates being highest among four investigated samples (ZnO tube, hexagonal, plate and flory-rod) at 2.9 × 104 at a concentration of MB of 10−4 M. To the best of our knowledge, this is the first investigation of detecting MB molecules using a pure semiconductor surface with a strong SERS activity.
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•We have successfully fabricated various morphologies of semiconductor ZnO microstructures by hydrothermal route, including tube, hexagonal, plate and flory-like structures.•These products were studied surface-enhanced Raman scattering (SERS) behaviour for probing methylene blue (MB) molecules with the enhancement factor (EF) achieving 2.9 × 104 (10−4 M).•The charge-transfer band corresponding to the interaction between the ZnO surface and the MB molecule was evidenced by examining the ground state absorption spectra with a large band centred at 600 nm.•The SERS mechanism is well elucidated based on the chemical enhancement mechanism related to both the formation of charge-transfer band and charge transfer.•The combination of the existence of charge-transfer band and charge-transfer resonance leads to the large enhancement factor of using pure ZnO as SERS surface.
Although it is unclear how Zn
2+
cooperates with Cu
2+
in synergistic antibacterial activity, a 1:10 ratio of Cu
2+
/Zn
2+
atoms and ethylenediaminetetra-acetic acid and urea ligands can be used to ...form a chelation complex containing Cu
2+
and Zn
2+
. This study investigated the effects of the combination of Cu
2+
and Zn
2+
in chelation with EDTA and urea. The results were compared with the outcomes of either copper or zinc alone against gram-negative
Escherichia coli (E. coli
) and gram-positive
Staphylococcus aureus (S. aureus
) bacteria. The antibacterial activity was determined through MICs, disc diffusion method, and bacterial cell growth curves. In addition, bacterial destruction by this chelation complex has been observed through SEM images. The presence of copper ion and zinc ion inside the bacterial cells has been proved through EDS measurements. The obtained results allowed us to draw conclusions that the use of both Cu
2+
and Zn
2+
in a chelation complex with EDTA and urea enhances the antimicrobial activity against these bacteria. The bacterial inhibition of this complex was stronger than that of Cu
2+
alone chelated with EDTA or CuSO
4
solution by approximately 100-fold for
S. aureus
and 20-fold for
E. coli
.
In this article, the influence of the medium refractive index on optical properties of gold nanorods (GNRs) and their surface enhanced Raman spectroscopy application were studied. In particular, GNRs ...have been applied in biomedical sensors to detect diseases by monitoring the changes in the environment. In this study, the changes in optical properties of GNRs were investigated according to the medium refractive index changes in the cationic surfactant cetyltrimethylammonium bromide (CTAB) during synthesis processes as well as GNR dispersion in different medium refractive indices. For instance, in the solutions with different concentrations of CTAB, GNRs were coated by biomolecules such as PEG, bovine serum albumin (BSA), and glutathione (GSH), which have different refractive indices. The fundamental reason for the change in optical properties of GNRs is also elucidated. GNRs have been used to enhance surface Raman scattering to detect indigo molecules. The results showed that due to the surface plasmon resonance effect, the GNRs could strongly enhance the scattering signal of indigo dyes, with the lowest detectable concentration of up to 10−8 M and with an enhancement coefficient of over 2000 times.
Incineration plants for electricity generation have offered a solution to the challenges of domestic solid waste treatment in many countries. However, their emissions, fly ash (FA) and bottom ash ...(BA), have had a detrimental impact on environmental quality. This study investigated the morphology, element composition, and concentration of metals in FA and BA from municipal solid waste incineration plants using scanning electronic microscopy/energy-dispersive X-ray and inductively coupled plasma mass spectrometry techniques. It also evaluated the distribution ratios of metal species across five fractions: exchangeable, carbonate-bound, oxide-bound, organic-bound, and sulfide-bound, and residual. The total metal content in both FA and BA was comparable, with calcium having the highest concentration (28,170–135,130 mg·kg
dry weight) and silver having the lowest (5.26–19.3 mg·kg
dry weight). However, the percentage proportion of metals differed between the extracted fractions. Except for cadmium in FA, ecological risk assessment indicated low direct bioavailability and potential risk of metals in both FA and BA. These findings contribute to the hazard assessment of FA and BA generated from waste incinerators and provide a scientific basis for developing treatment techniques for this type of waste.
Recently, there have been publications on preparing hybrid materials between noble metal and semiconductor for applications in surface-enhanced Raman scattering (SERS) substrates to detect some toxic ...organic dyes. However, the use of cuprous oxide/silver (Cu
O/Ag) to measure the trace amounts of methyl orange (MO) has not been reported. Therefore, in this study, the trace level of MO in water solvent was determined using a SERS substrate based on Cu
O microcubes combined with silver nanoparticles (Ag NPs). Herein, a series of Cu
O/Ag
(
1-5) hybrids with various Ag amounts was synthesized via a solvothermal method followed by a reduction process, and their SERS performance was studied in detail. X-ray diffraction (XRD) and scanning electron microscopy results confirmed that 10 nm Ag NPs were well dispersed on 200-500 nm Cu
O microcubes to form Cu
O/Ag heterojunctions. Using the as-prepared Cu
O and Cu
O/Ag
as MO probe, the Cu
O/Ag5 nanocomposite showed the highest SERS activity of all samples with the limit of detection as low to 1 nM and the enhancement factor as high as 4 × 10
. The logarithm of the SERS peak intensity at 1389 cm
increased linearly with the logarithm of the concentration of MO in the range from 1 nM to 0.1 mM.
Silica nanoparticles (SiO2 NPs) synthesized by the Stober method were used as drug delivery vehicles. Doxorubicin hydrochloride (DOX·HCl) is a chemo-drug absorbed onto the SiO2 NPs surfaces. The ...DOX·HCl loading onto and release from the SiO2 NPs was monitored via UV-VIS and fluorescence spectra. Alternatively, the zeta potential was also used to monitor and evaluate the DOX·HCl loading process. The results showed that nearly 98% of DOX·HCl was effectively loaded onto the SiO2 NPs’ surfaces by electrostatic interaction. The pH-dependence of the process wherein DOX·HCl release out of DOX·HCl-SiO2 NPs was investigated as well. For comparison, both the free DOX·HCl molecules and DOX·HCl-SiO2 NPs were used as the labels for cultured cancer cells. Confocal laser scanning microscopy images showed that the DOX·HCl-SiO2 NPs were better delivered to cancer cells which are more acidic than healthy cells. We propose that engineered DOX·HCl-SiO2 systems are good candidates for drug delivery and clinical applications.
Polychlorinated biphenyls (PCBs) in transformer and food oils were measured using gas chromatography combined with multiphoton ionization mass spectroscopy. An ultrashort laser pulse emitting in the ...far-ultraviolet region was utilized for efficient ionization of the analytes. Numerous signal peaks were clearly observed for a standard sample mixture of PCBs when the third and fourth harmonic emissions (267 and 200nm) of a femtosecond Ti:sapphire laser (800nm) were employed. The signal intensities were found to be greater when measured at 200nm compared with those measured at 267nm, providing lower detection limits especially for highly chlorinated PCBs at shorter wavelengths. After simple pretreatment using disposable columns, PCB congeners were measured and found to be present in the transformer oils used in Vietnam.
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•PCB congeners would be ionized by a process of two-photon ionization at 267 and 200nm.•The ionization energies were predicted to be 8.10–8.59eV for the PCB congeners.•PCBs were detected from the oil samples obtained in Vietnam.•A femtosecond laser emitting at 200nm was useful for sensitive detection of PCBs.
Silica–gold core–shell nanoparticles (NPs) were prepared by gold ion plating on hydrophilic-functionalized silica core NPs using formaldehyde as a reducing reagent. The monodisperse silica particles ...were first prepared by a sol–gel method, while the ultrafine gold colloids (diameter 1–2 nm) were synthesized by the reduction of chloroauric acid with tetrakis(hydroxymethyl)phosphonium chloride. The growth and attachment of the gold NPs onto the functionalized surface of the silica NPs with average diameter ranging from 40 to 180 nm, using a low-temperature-mediated route, were systematically investigated. The coverage of the gold NPs and clusters on the surface of the silica NPs have been evaluated by means of UV–Vis/near-infrared spectroscopy and transmission electron microscopy. The surface plasmon resonance absorption spectra from 550 to 1,000 nm of the core–shell NPs can be effectively controlled by the surface gold coverage or the silica core NP’s size.
Abstract This study examines the fly ash from Soc Son municipal waste power plant (SMPP) and suggests ways to repurpose it to reduce its environmental impact. Fly ash from the Soc Son waste power ...plant has a gray color, spherical particles with a 5–103 μ m diameter, and a high carbon and heavy metal content. Bermorite crystals can absorb and release heavy metals, making monitoring secondary pollutants during incineration crucial. The EDX analysis of fly ash from the Soc Son waste power plant revealed that it was predominantly contaminated with metal elements, with the highest percentage of calcium. The EDX was able to detect heavy metals in incinerator fly ash. The concentration of Zn in the fly ash exceeded QCVN 07:2009/BTNMT standards, indicating the high amounts of some elements that may be hazardous to the environment and human health. Using the SEM/EDX and XRF, the fly ash from the Soc Son landfill power plant was analyzed and discovered that it exceeds permissible limits for dangerous heavy elements. The most common inorganic elements are Ca, followed by Zn, Pb, Cd, and Ag. Fly ash is classed as hazardous waste due to its high concentration of heavy metals, which results from the combustion of municipal solid waste that has not been separated. Vietnam fights municipal solid waste incinerator fly ash production. Some nations stabilize fly ash to remove harmful components and use it in buildings. Stabilized fly ash makes unfired construction bricks and cement manufacturing components and combining fly ash with inorganic trash protects the environment.
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