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This study investigates the application of surface-enhanced Raman spectroscopy (SERS) in the diagnosis of liver cancer using Ag@SiO2 nanoparticles as SERS substrates. A SERS test was conducted on serum samples obtained from patients with liver cancer and healthy individuals. After repeated several times experiments, it was found that the best SERS spectrum was obtained when the volume ratio of serum to deionized water was 1:2. Moreover, data preprocessing was performed on the tested SERS spectrum, and the preprocessed spectral data were combined with principal component analysis (PCA), partial least-squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA) for further analysis to classify the serum samples of patients with liver cancer and healthy individuals. The results showed that the classification effect of standard normal variate spectral data combined with the OPLS-DA was the best for the serum samples, with a classification accuracy of 97.98%, sensitivity of 97.14%, and specificity of 98.44%. Therefore, the SERS technology can be developed as a favorable method for the accurate diagnosis of liver cancer in the future.

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Due to the unique physicochemical properties of gold nanoparticles (AuNPs) decorated silica nanostructures (SiO2@AuNPs), they show great potential for applications in catalysis, biosensing, optical devices and medicine. It is essential to explore the catalytic effect of SiO2@AuNPs and the understanding of the essential process of catalytic reactions. We have prepared SiO2@AuNPs by loading small-sized AuNPs on surface-modified silica nanospheres. SiO2@AuNPs was used as a catalyst for the catalytic reduction of 4-nitrophenol (4-NP) in the presence of excess NaBH4, and the results showed that with the increase of the amount of catalyst from 30 to 100µl, the corresponding rate constantKappwas increased from 6.44 × 10-3to 1.45 × 10-2s-1, and its TOF was as high as 1.326 × 103h-1, and the catalytic rate could still be maintained at 87% after five cycles. By analyzing the morphology and size of the SiO2supported AuNPs before and after the catalytic reaction, it can be seen that the atoms on the surface of small-sized AuNPs supported by silica have migrated during the catalytic process, which subsequently affects the catalytic efficiency of the structure. This study proves the good catalytic effect of SiO2@AuNPs structure and lays the foundation for its wider application.

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LncRNA plays a pivotal role in the stemness and drug resistance of lung cancer. Here, we found that lncRNA-AC026356.1 was upregulated in stem spheres and chemo-resistant lung cancer cells. Our fish assay also shows that AC026356.1 was predominantly located in the cytoplasm of lung cancer cells and does not have protein-coding potential. Silencing AC026356.1 significantly inhibited proliferation and migration but increased apoptosis in A549-cisplatin (DDP) cells. Additionally, IGF2BP2 and the lncRNA-AC026356.1 positively regulated the proliferation and stemness of stem-like lung cancer cells. Further mechanistic investigation revealed that METTL14/IGF2BP2-mediated m6A modification and stabilization of the AC026356.1 RNA. Functional analysis corroborated that AC026356.1 acted as a downstream target of METTL14/IGF2BP2 and AC026356.1 silencing could block the oncogenicity of lung cancer stem-like cells. AC026356.1 expression was correlated with immune cell infiltration and T cell exhaustion. Compared with paired adjacent normal tissues, lung cancer specimens exhibited consistently upregulated METTL14/IGF2BP2/AC026356.1. M6A-modified METTL14/IGF2BP2/AC026356.1 loop may serve as a potential therapeutic target and prognostic predictor for lung cancer therapy and diagnosis in the clinic.

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Carbosulfan gets easily decomposed into carbofuran and 3-Hydroxy carbofuran in vegetables and forms harmful residues. To detect the residues of carbosulfan in vegetables (for example, cowpeas), a super-sensitive method of surface-enhanced Raman spectroscopy (SERS) was used in this work. Silver sol was prepared as the SERS substrate. To solve the adsorption problem of carbosulfan on Ag nanoparticles, 2, 6-dichloroquinone-4-chlorimide (chromogenic agent), and sodium hydroxide were added in carbosulfan to generate a complex, which was then mixed with the silver sol in the best proportion to examine SERS spectra. According to density functional theory calculations, the spectral peak positions of carbosulfan were determined. The optimal mixing ratio of the complex and the silver sol to obtain the optimal SERS spectrum and the detection limit of carbosulfan were investigated. The ultra-sensitive detection of carbosulfan residues (8.7 × 10-11 g/L) in cowpeas was realized. The results of this work indicate that SERS is a promising technique for detecting single-molecule pesticide residues in vegetables.

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Gold nanostructures are used as catalysts in heterogeneous catalytic processes and have intrigued chemists and materials scientists. Isotropic spherical gold nanoparticles (AuNPs) are ideal for catalysis due to their simple preparation process, controllable surface-active site, tunable size, and composition-dependent catalytic activity. In this study, spherical AuNPs with different size, composition, and surface capping agents have been prepared, and their catalytic activity in reduction of 4-nitrophenol (4-NP) is evaluated. The catalytic activity of AuNPs decreases as their size increases. Meanwhile, the catalytic activity of AuNPs with tartrate as the reducing agent show no evident changes because of containing anisotropic AuNPs. Moreover, silver not only improves monodisperse and spherical AuNPs, but also increases the catalytic activity of small AuNPs. Since the molecular structures of tartrate and citrate are similar, there is no remarkable difference in the catalytic activity of AuNPs using tartrate and citrate as capping agents. These results demonstrate the influence of size, composition, and surface capping on the catalytic activity of AuNPs. Overall, this study facilitates the applicability of gold-based catalyst and AuNPs in plasmonics, nanophotonics, biomedical photonics, and photocatalysis.

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Anisotropic gold nanostructures have attracted great attention in different fields including catalysis. Thermodynamically driven selective surface growth offers a reliable and reproducible method for anisotropic gold nanoparticle synthesis with specific morphologies. Herein, monocrystalline concave gold nano-arrows (AuCNAs) are prepared by the over-growth method using Au nanorods (AuNRs) as seeds. The as-prepared AuCNAs consist of a biconical head and four concave structures. Interestingly, silver ions (Ag+) concentration significantly affects the product morphology by tuning the peak positions of surface plasmon resonance (SPR), aspect ratio, arrow, and concave morphology of AuCNAs. The position of longitudinal SPR peaks is observed at 810, 805 and 782 nm at [Ag+]/[Au3+] molar ratios of 1:2, 1:1, and 2:1, respectively. Diameters and lengths of AuCNAs varied from 25 nm to 36 nm; 104 nm, 78 nm, and 120 nm, respectively. Additionally, the AuCNAs are applied for the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in presence of excess NaBH4. Compared to gold nanorods (AuNRs), the prepared AuCNAs catalyst shows excellent catalytic activity, demonstrating that concave structures and sharp corners significantly enhance the catalytic activity. The value of pseudo-first-order reaction kinetic constants (kapp) increased from 0.0051 to 0.0195 s-1 with increasing catalyst valume from 7.5 to 37.5 µL. The highest normalized reaction rate constant (Knor) and turnover frequency (TOF) reach 5.84 × 104 min-1 mmol-1 and 443.47 h-1, respectively, at [Ag+]/[Au3+] ratio of 1:1 in AuCNAs catalyst. This study expands catalytic applications of anisotropic gold nanostructures and widens their potential application areas, such as surface plasmon exciton photonics, biomedical photonics, and photocatalysis.

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Two-dimensional (2D) gold nanoplates (AuNPLs) have shown potential in catalysis, photonics, electronics, sensing, and biomedicine fields due to their high aspect ratio, fascinating surface chemistry, and quantum-size effect. Therefore, the synthesis of substrate-free, size-controlled single-crystal gold (Au) nanoplates is highly desirable for the development of catalysis and optical near-field enhancement applications. EDTA and hydroxide anions were used in this study to stimulate the formation of microscale single-crystal gold nanoplates under hydrothermal conditions. The reaction temperature, amount of EDTA, and hydroxyl anions all have a significant effect on the morphologies and size distributions of the gold nanoplates. The gold nanoplates had an average side length of between 3 and 11 µm. The application of the microscale single-crystal gold nanoplates as a nanocatalyst proved their excellent catalytic activity and recyclability for the catalysis of 4-nitrophenol to 4-aminophenol, implying that the large-size gold nanoplates were promising in heterogeneous catalysis applications.

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An ultrasensitive Ag-deposited TiO2 flower-like nanomaterial (FLNM) surface-enhanced Raman scattering (SERS)-active substrate is synthesized via a hydrothermal method, and Ag nanoparticles (NPs) are deposited through electron beam evaporation. Malachite green (MG), which is widely used in aquaculture, is employed to assess the surface-enhanced Raman scattering (SERS) properties of TiO2/Ag FLNMs. They exhibit ultrasensitivity (limit of detection (LOD) of MG reaches 4.47 × 10-16 M) and high reproducibility (relative standard deviations (RSDs) are less than 13%); more importantly, the TiO2/Ag FLNMs are recyclable, as enabled by their self-cleaning function due to TiO2 photocatalytic degradation. Their recyclability is achieved after three cycles and their potential application is examined in the actual system. Finite difference time domain (FDTD) simulations and the charge-transfer (CT) mechanism further prove that the excellent SERS properties originate from localized surface plasmon resonance (LSPR) of Ag NPs and the coupling field between Ag and TiO2 FLNMs. Therefore, TiO2/Ag FLNMs show promising application in aquaculture.

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PURPOSE: Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths in the United States, accounting for 85% of all diagnosed lung cancers and resulting in over 100,000 deaths per year. The main purpose of the current study was to investigate the antiproliferative effects of ethanolic extract of Artemisia maritima in three human lung cancer cell lines along with studying the effects of the herbal extract on cellular apoptosis, G2/M cell cycle arrest and cell migration. METHODS: The CCK-8 assay was used to determine cell viability. Apoptosis was detected by using acridine orange (AO)/ethidium bromide (EB) staining, annexin V/propidium iodide (PI) assay and western blot. The cell migration was determined by wound healing assay while the effects on cell cycle were evaluated by flow cytometry. RESULTS: The results showed that herbal extract of Artemisia maritima decreased the viability of all three cell lines H1299, NCI-H1437, PC-14 dose-dependently with maximum effect on NCI-H1437 cell line. The antiproliferative effects were due to the activation of mitochondrial-dependent apoptotic pathway as seen by fluorescence microscopy which showed chromatin condensation and nuclear fragmentation. This was also associated with increase in Bax and decrease in Bcl-2 levels. Artemisia maritima extract treatment also led to G2/M phase cell cycle arrest along with strong inhibition of cell migration. CONCLUSIONS: In conclusion, the results of the current study clearly indicate that Artemisia maritima extract exhibits antiproliferative effects in Nonsmall cell lung cancer cells by triggering apoptosis, cell cycle arrest and inhibition of cell migration.

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A seed-mediated electroless deposition (SMED) approach for fabrication of large-area and uniform gold nanoparticle films as efficient and reproducible as surface-enhanced Raman scattering (SERS) substrates was presented. This approach involved a seeding pretreatment procedure and a subsequent growth step. The former referred to activation of polylysine-coated glass slides in gold seed solution, and the latter required a careful control of the reactant concentration and reaction time. With the aid of gold seeds and appropriate reaction conditions, a large-area and uniform nanofilm with evenly distributed gold nanoparticles (Au NPs) was formed on the surface of the substrates after adding a mixed solution containing ascorbic acid and trisodium citrate. The morphology of the Au nanofilm was examined by scanning electron microscopy. The size evolution of Au NPs on the surface of the substrates was analyzed in detail. The nanofilm substrate was prepared by reaction conditions of the seeded activation process: 10 mL ascorbic acid and trisodium citrate mixture and 30 min of soaking time, which exhibited an excellent uniformity and reproducibility of SERS enhancement with relative standard deviation (RSD) values of less than 8% (particularly, a RSD value of 3% can be reached for the optimized measurement). Compared to the common electroless deposition, the seed-mediated electroless deposition possessed inherent advantages in controllability, reproducibility, and economic benefit.

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A simple and rapid approach to synthesize monodisperse and biocompatible gold nanoparticles (AuNPs) employing dextran as a reducing and stabilizing agents at different reaction conditions was described. The obtained dextran-gold nanoparticles (Dex-AuNPs) were characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, Nuclear magnetic resonance (NMR) spectroscopy, Fourier transformer infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis. The TEM examinations showed the resultant particles were 4-50 nm in size, monodispersity and uniform particle size distribution. Moreover, the size of the nanoparticles can be controlled by varying the concentration of the reactants. UV-Vis spectra showed that the characteristic localized surface plasmon resonance (LSPR) band of AuNPs was at about 525 nm. NMR spectroscopy and FTIR spectroscopic analysis suggested the detailed structural information of dextran before and after synthesis of AuNPs. XRD and selected area electron diffraction (SAED) pattern analysis demonstrated that the colloidal nanoparticles had a well crystallized structure. The experimental analyses revealed that NaOH played an important role in the synthesis of Dex-AuNPs. And the possible formation mechanism of the fabrication of these Dex-AuNPs was also proposed. MTT assay was utilized to evaluate the cytotoxicity of the synthesized Dex-AuNPs on HeLa cells and SiHa cells. These results suggested that the prepared Dex-AuNPs complexes had excellent biocompatibility and acted as a candidate for further biomedical application.

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The reflection of a TM-polarized light beam from a Kretschmann configuration with a saturable gain medium is investigated theoretically. Here, the dielectric constant of the gain medium is described by a classical Lorentzian oscillator model. When surface plasmon polaritons are effectively excited in this structure, it is demonstrated that the curves of enhanced total reflection (ETR) show different shaped hysteresis loops associated with optical bistability owing to gain saturation effect. The effects of the angle of incidence, the thickness of metal film, and the value of small-signal gain on bistable ETR are discussed in detail in a homogeneously broadened (HB) gain medium at line center. Analogous results can also be obtained in an inhomogeneously broadened (inHB) gain medium, while the two switch thresholds and the width of optical bistability hysteresis in an inHB gain medium are significantly different from those in a HB gain medium.

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Gold nanoparticles (AuNPs) have been researched extensively, such as applied in various biosensors, biomedical imaging and diagnosis, catalysis and physico-chemical analysis. These applications usually required to know the nanoparticle size or concentration. Researchers have been studying a simply and quick way to estimate the concentration or size of nanoparticles from their optical spectra and SPR feature for several years. The extinction cross-sections and the molar attenuation coefficient were one of the key parameters. In this study, we calculated the extinction cross-sections and molar attenuation coefficient (decadic molar extinction coefficient) of small gold nanoparticles by dipole approximation method and modified Beer-Lambert law. The theoretical result showed that the surface plasmon resonance peak of small gold nanoparticles was blueshift with an increase size. Moreover, small AuNPs (sub-10nm) were prepared by using of dextran or trisodium citrate as reducing agent and capping agent. The experimental synthesized AuNPs was also shows a blueshift as increasing particle size in a certain range. And the concentration of AuNPs was calculated based on the obtained molar attenuation coefficient. For small nanoparticles, the size of nanoparticles and surface plasmon resonance property was not showed a positive correlation compared to larger nanoparticles. These results suggested that SPR peak depended not only on the nanoparticle size and shape but also on the nanoparticles environment.

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Alkaline silver colloid with better stability and uniformity was obtained by adding appropriate amount of NaOH to synthesis reaction. The performance of the Ag colloid as surface enhanced Raman scattering (SERS) active substrate was evaluated by methylene blue as the probe molecules and achieved well Raman spectra. The concentration of methylene blue had no effect on the adsorptive behavior of methylene blue on alkaline silver colloid surface in comparison with normal silver colloid. The basic reason for this phenomenon is preferential adsorption of alkaline silver colloid for sulfur atoms of methylene blue so as to increase the intensity of 451 cm-1 Raman peak consistently. The amounts of methylene blue added to alkaline Ag colloid and time-evolution of Raman spectra were also investigated. Additionally, the alkaline silver colloid was prepared to be silver spot and applied to detect melamine doped milk. The relationship of the doping amount of melamine and the Raman signal intensity was obtained. The linearity relationship in the concentration range between 3 and 60 mg.L-1 with detect limit 0.28 mg.L-1 was achieved based on the intensity of 691 cm-1 Raman peak This method required only 5 microL sample size and 5 s for detection and suggested that this presented method with its advantages of speediness, briefness and lower cost has a good application foreground.

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Cetyltrimethyl ammonium bromide (CTAB) has been extensively applied in the solution-phase synthesis of many types of colloidal nanoparticles. However, the uses of CTAB were mainly considered as template or capping agents to form controllable shape and protect the product from agglomeration. Here it was discovered that CATB could serve as a very mild reductant to reduce gold salt precursors preparing gold nanoparticles (GNPs) at base environment. CTAB acted as the reducing agent suffering a partial degradation and forming CTA macro radicals. FTIR proved the formation of CCl and/or CBr bond after CTAB degraded. The characterization of synthesized GNPs was examined by UV-Vis spectra, TEM and XRD. Several factors affecting the process of reaction, such as the amount of NaOH, the molar ratio of CTAB and HAuCl(4), the reaction temperature, the effect of light and oxygen, and stirring were discussed.

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The isoquinoline plant alkaloid berberine has anti-tumor effects on a variety of carcinoma cells, mainly through inhibition of cell proliferation, apoptosis induction and cell cycle arrest. However, the mechanisms underlying its role in tumor progression are unknown. In the present study, we investigated the molecular mechanisms involved in berberine-induced cell death in human hepatoma carcinoma cell (HCC) lines HepG2 and SMMC7721. Our results showed that berberine inhibited tumor cell viability in a dose- and time-dependent manner, and induced cell death via apoptosis and autophagy. Moreover, berberine treatment significantly inhibited CD147 expression by HCC cells in a dose-dependent manner. Overexpression of CD147 protein markedly reduced berberine-induced cell death. Our data provide the first experimental evidence that berberine induces cell death in HCC cells via downregulation of CD147 and suggest a new mechanism to explain its anti-tumor effects.

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