The remarkable enhancement of photo-stability and antioxidant protection of lutein coupled with carbon-dot.

Lutein is a carotenoid that is beneficial to human health. However, its low stability and bioavailability have limited its application in the pharmaceutical and food industries. Herein, lutein has been successfully modified with carbon-dots (CDs) via a simple and mild solvent-ultrasonic method at room temperature. The synthesized lutein/CDs composites (LCs) showed 3.4 times higher photostability than the pristine lutein under UV irradiation, and 3.5 times higher than that under visible light, and the retention rate of lutein in the air rose from 3.6 % to 68 % over 25 days. Meanwhile, the antioxidant capacity of lutein has been improved by 6.4 times. Based on the photoluminescence (PL) measurements, a possible mechanism for the enhanced photostability and antioxidant ability of LCs has been proposed. The work provides a simple but effective approach to enhancing the stability and antioxidant capacity of lutein, and is expected to extend its application in food and biomedical fields.

Hydrothermally activated TiO2 nanoparticles with a C-dot/g-C3N4 heterostructure for photocatalytic enhancement.

Dye degradation via photocatalysis technology has been investigated intensively to tackle environmental issues and energy crisis concerns. In this study, a newly designed ternary photocatalyst was facilely prepared by a simple one-pot hydrothermal process by directly mixing TiO2 nanoparticles with carbon dots (C-dots) and graphitic carbon nitride (g-C3N4). The optimized precursor treatments and heterostructure components show significantly enhanced photodegradation activity towards organic dyes Rhodamine B (RhB) and methylene blue (MB). Excellent photocatalytic activities were achieved owing to the better attachment of anatase-type TiO2 nanoparticle-aggregations to the C-dots/g-C3N4 (CC) nanocomposite, which impressively displays superhydrophilicity by employing the hydrothermal activation process. FT-IR spectra revealed that the hydrothermal treatment could remarkably increase the coupling interactions between TiO2 nanoparticles and the CC nanosheets within the ternary catalyst, enhancing the photocatalytic activity. Thus, it was concluded that this ternary photocatalyst is highly suitable for the remediation of dye-contaminated wastewater.

Electron/energy co-transfer behavior and reducibility of Cu-chlorophyllin-bonded carbon-dots.

Cu-chlorophyllin-bonded carbon dots (CCPh-CDs) have been synthesized at room temperature, and the energy/electron co-transfer behavior between Cu-chlorophyllin molecules (CCPh) and carbon dots (CDs) is investigated via various techniques. The mean diameters of CDs and CCPh-CDs are 2.8 nm and 3.1 nm, respectively, measured by HRTEM. The absorption spectra of CCPh-CDs show two parts: the absorptions of CDs and CCPh are in the wavelength range of 300-500 nm. The PL spectra of CCPh-CDs exhibit very weak intensities, and with the decreasing of CCPh content on CDs, the corresponding intensity increases. Luminescent decay spectra show that the PL decay times of CCPh and CCPh-CDs with the highest CCPh content are single-exponentially fitted to be 3.20 ns and 12.64 ns, respectively. Furthermore, based on the electron transfer and reducibility of CCPh-CDs, Ag/Ag2O nanoparticles with a mean diameter of 10 nm can be easily prepared at room temperature under ultraviolet irradiation. The PL measurement result reveals that both electron transfer and FRET behavior take place from CCPh-CDs to Ag.

Excellent Adsorptive Behaviors of ZnO Nanoparticle-Deposited Activated Carbon Covered with Nano-Graphene Oxide.

In the paper, ZnO-deposited activated carbon composite (ZnO-AC) was firstly prepared in a simple two-step preparation process, and then covered with nano-graphene oxide to give the NGO-ZnOAC composite. The successful deposition of ZnO and NGO on the AC surface was demonstrated by various experiments, and the ZnO nanoparticles showed a mean diameter size mainly within about 10 nm. The specific surface area of the NGO-AC and NGO-ZnO-AC decreased from 67.74 m²/g of the parent AC to 32.54 and 11.43 m²/g, respectively. The fabricated NGO-ZnO-AC showed excellent adsorptive behaviors towards CrO2-4 and Cu2+ ions, outperforming both ZnO-AC and AC.

Shikonin reduces tamoxifen resistance through long non-coding RNA uc.57.

Tamoxifen resistance is a serious problem in the endocrine therapy of breast cancer. Long non-coding RNAs play important roles in tumor development. In this study, we revealed the involvement of lncRNA uc.57 and its downstream gene BCL11A in TAM resistance. Tamoxifen-resistant MCF-7R cells showed lower expression of uc.57 and higher expression of BCL11A mRNA and protein than the parental MCF-7 cells. Moreover, levels of uc.57 mRNA were lower and BCL11A mRNA were higher in breast cancer tissues than in precancerous breast tissues. Shikonin treatment reduced tamoxifen resistance in MCF-7R cells both in vitro and in vivo, targeting uc.57/BCL11A. Fluorescence in situ hybridization and RNA immunoprecipitation analyses showed that uc.57 binds to BCL11A. Uc.57 overexpression downregulated BCL11A and reduced tamoxifen resistance in MCF-7R cells both in vitro and in vivo. BCL11A knockdown also reduced tamoxifen resistance by inhibiting PI3K/AKT and MAPK signaling pathways. It thus appears shikonin reduces tamoxifen resistance of MCF-7R breast cancer cells by inducing uc.57, which downregulates BCL11A to inhibit PI3K/AKT and MAPK signaling pathways.

uc.38 induces breast cancer cell apoptosis via PBX1.

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 bp with no protein-coding capacity. Transcribed ultraconserved regions (T-UCRs) are a type of lncRNA and are conserved among human, chick, dog, mouse and rat genomes. These sequences are involved in cancer biology and tumourigenesis. Nevertheless, the clinical significance and biological mechanism of T-UCRs in breast cancer remain largely unknown. The expression of uc.38, a T-UCR, was down-regulated in both breast cancer tissues and breast cancer cell lines. However, uc.38 was expressed at significantly lower levels in larger tumours and tumours of more advanced stages. Based on the results of in vitro and in vivo experiments, up-regulation of uc.38 expression inhibited cell proliferation and induced cell apoptosis. Thus, uc.38 suppressed breast cancer. Additional experiments revealed that uc.38 negatively regulated the expression of the pre-B-cell leukaemia homeobox 1 (PBX1) protein and subsequently affected the expression of Bcl-2 family members, ultimately inducing breast cancer cell apoptosis. Describing the uc.38/PBX1 axis has improved our understanding of the molecular mechanisms involved in breast cancer apoptosis and has suggested that this axis is a potential therapeutic target for breast cancer.

[Preparation, characterization and upconversion fluorescence of NaYF4 : Yb, Er /graphene oxide nanocomposites].

NaYF4 : Yb, Er/rGO and SiO2-coated NaYF4 : Yb, Er/rGO nanocomposites can be prepared through "one-pot" and directly mixing preparation routes. Various measurement results show that the NaYF4 : Yb, Er in the nanocomposites exhibits a cubic a-type structure and nanoparticle-like morphology with a diameter range of 30-70 nm; the rGO layers are well-dispersed in the nanocomposites, and whereas the rGO obtained from "one-pot" preparation renders relatively better dispersion. Raman spectra demonstrate that there exists a surface coupling action between the two kinds of nanomaterials, and with the increase in the relative rGO content, such action becomes stronger. UC fluorescence measurement results reveal that the rGO has significantly quenching effect and optical-limiting performance on the UC fluorescence, particularly on the red-emission of the NaYFa : Yb, Er or SiO2-coated NaYF4 : Yb, Er nanoparticles. The red-emission intensity gradually decreases with an increase in the rGO content, but the green-emission shows less change. It should be stressed that, in comparison with NaYF4 : Yb, Er/rGO, with a similar rGO content, the red-emission intensity of SiO2-coated NaYF4 : Yb, Er/rGO decreases much obviously due to a stronger light-absorption caused by part rGO aggregation.

[Preparation of CdSe nanoparticle-deposited TiO2 nanobelts and their visible-light photocatalysis].

A series of CdSe nanoparticle-deposited anatase TiO2 nanobelts were prepared by hydrothermal process. Their crystal structures, morphologies, depositing content of CdSe and visible-light photocatalytic activities were characterized using various measurement techniques. The measurement results show that the CdSe nanoparticles with zinc blende face-center-cubic structure and controlled content have deposited on anatase TiO2 nanobelts; the special surface areas of the products become lower in comparison with that of TiO2 nanobelts due to the deposited CdSe, whereas their visible-light absorptions exhibit much more obviously. The visible-light photocatalytic activities in degradation of rhodamine B solution demonstrate that the products with excess depositing content of CdSe nanoparticles and existence of NH3 molecules on the surface, show much lower photodegrada tion activities. On the contrary, the products with less CdSe nanoparticles and less NH3 molecules exhibit much higher photodegradation activities.

[Visible-light responding BiVO4/TiO2 nanocomposite photocatalyst].

The two kinds of new nanocomposites BiVO4/TiO2 nanowires were synthesized by hydrothermal process. Their crystal structure, morphology and photocatalytic activities for degradation of methylene blue solution were characterized using various measurement techniques. The XRD results indicate that they are made up of monoclinic BiVO4 and anatase TiO2 phases. The SEM, TEM and HRTEM images show that the two samples include BiVO4 nanoparticles supported onto TiO2 nanowires. The UV-Vis absorption spectra reveal that the absorption edges of the samples exhibit red-shift in comparison with that of the pure TiO2 nanowires. The measurement results for the visible-light photodegradation of methylene blue show that the nanocomposite sample prepared from the layered titanate nanowires with Bi3+ has the highest photocatalytic activity.

[Simple preparation and characterization of MTiO3 (M = Sr or Ba) supported on TiO2 nanorods].

Cubic phase MTiO3 (M = Ba or Sr) nanoparticle-supported TiO2 nanocomposites were prepared using Sr(OH)2 or Ba(OH)2 and TiO2 nanobelts as precursors by hydrothermal process. Their component, phase, morphology, structure and optical property were characterized using various XRD, SEM, TEM, HRTEM and UV-Vis techniques. The measurement results show that the more or less MTiO3 nanoparticles are affected by the amount of added Sr(OH)2 or Ba(OH)2 and the change in reaction time, and to some extent, the content of the MTiO3 is increased with the increase in the added hydroxide precursor and the prolonging of reaction time. Either the pure TiO2 nanobelts or the nanocomposites show the similar absorption and emission spectra. Their visible photodegradation activities of rhodamine B appear much higher than that of P-25.