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The graphene oxide (GO) was used to improve the mechanical performances of epoxy asphalt (EA) by preparing GO/EA composite. The influence of the GO dosage on the micro-structure, curing rheology, mechanical and thermal properties of GO/EA was investigated. According to the XRD and Fourier transform infrared spectra, the GO was exfoliated in the EA matrix and modified EA by non-covalent strategy. GO decreased the rotational viscosity of EA and increased the pot life. The GO/EA with 0.1 wt.% GO showed excellent toughness that the elongation at break was increased by 164%, and the tensile and pull-off adhesion strength were nearly equal to that of EA. The addition of GO improved the original thermal decomposition temperature (T5%), glass transition temperature (Tg), compatibility and stiffness of the EA. The improved mechanical and thermal properties of GO/EA may be attributed to (1) excellent performances of GO and (2) inhibiting effect of GO on the EA curing process. [ABSTRACT FROM AUTHOR]

Aim: To prepare RGD-modified long circulating liposome (LCL) loading matrine (RGD-M-LCL) to improve the tumor-targeting and efficacy of matrine. Methods: LCL which was prepared with HSPC, cholesterol, DSPE-PEG2000 and DSPE-PEG-MAL was modified with an RGD motif confirmed by high performance liquid chromatography (HPLC). The encapsulation efficiency of RGD-M-LCL was also detected by HPLC. MTT assay was used to examine the effects of RGD-M-LCL on the proliferation of Bcap-37, HT-29 and A375 cells. The percentage of apoptotic cells and morphological changes in Bcap-37 cells treated with RGD-M-LCL were detected by Annexin-V-FITC/PI affinity assay and observed under light microscope, respectively. Results: Spherical or oval single-chamber particles of uniform sizes with little agglutination or adhesion were observed under transmission electronic microscope. The RGD motif was successfully coupled to the DSPE-PEG-MAL on liposomes, as confirmed by HPLC. An encapsulation efficiency of 83.13% was obtained when the drug-lipid molar ratio was 0.1, and the encapsulation efficiency was negatively related to the drug-lipid ratio in the range of 0.1~0.4, and to the duration of storage. We found that, compared with free matrine, RGD-M-LCL had much stronger in vitro activity, leading to anti-proliferative and pro-apoptotic effects against cancer cells (PConclusion: RGD-M-LCL, a novel delivery system for anti-cancer drugs, was successfully prepared, and we demonstrated that the use of this material could augment the effects of matrine on cancer cells in vitro.

Aim: to investigate effects of Losartan on expression of connexin 40 and 43 (Cx40 and Cx43), in arteries at the early stage of atherosclerosis in a rabbit model. Methods: A total of 28 male New Zealand white rabbits were divided into following groups: control group, high fat diet group, and Losartan group (10 mg/kg/day). Losartan was administrated in food for two weeks. Iliac arteries were obtained for immunohistochemistry, transmission electron microscopy, Western blot, and reverse transcriptase-polymerase chain reaction (RT-PCR). Results: Transmission electron microscopy revealed abundant gap junctions between neointimal smooth muscle cells (SMCs), which were markedly reduced by treatment. RT-PCR and Western blot assay showed that the mRNA and protein expression of Cx40 and Cx43 were elevated in the neointimal area at the early stage of atherosclerosis. The mRNA and protein expression of Cx43 were significantly down-regulated by losartan treatment but those of Cx40 were not markedly changed. Conclusion: Cx40 and Cx43 in the neointimal SMCs were up-regulated at the early stage of atherosclerosis. Losartan (an angiotensin-converting enzyme inhibitor) could reduce neointima proliferation and down-regulate the elevated protein expression of Cx43, suggesting the rennin-angiotensin system (RAS) plays an important role in the remodeling of gap junction between ventricular myocytes under pathological conditions.

The remediation of heavy metal deserves to be on the agenda, with the adsorbent design bearing the brunt of it. In this study, the molecule (4, 6-diamino-2-mercaptopyrimidine, DMP) containing thiol (-SH) and amino (-NH2) functional groups was grafted onto Uio-66-NH2, and a composite metal–organic framework nanomaterial (Zr(NH2)-DMP) was synthesized via a facile post-modification scheme. The morphological characteristics and structural features of the modified adsorbent were characterized by XRD, FT-IR, FE-SEM, EDS, BET, and XPS. The characterization results verified that the post-modification scheme was successfully achieved. The adsorption experiments were carried out to investigate the removal performance of the Zr(NH2)-DMP towards Hg2+ under different influencing parameters. The maximum adsorption capacity of 389.4 mg/g was obtained, and the adsorption equilibrium was achieved within 30 min at pH 6 at room temperature. Adsorption thermodynamic study indicated that the adsorption process was exothermic and spontaneous. The Zr(NH2)-DMP exhibited excellent selectivity for Hg2+, and also has the potential to remove Cu2+, Fe2+, and Zn2+ ions. The introduction of Cl− inhibited the removal of Hg2+ due to the formation of mercuric chlorides (removal efficiency reduced from 97.8 to 95.6%). The removal efficiency of up to 86.7% was obtained after four cycles. The Langmuir isotherm and Pseudo-second kinetic were more suitable for fitting the adsorption process of Hg2+ by Zr(NH2)-DMP. The main removal mechanism could be attributed to the chelation between Hg2+ (soft acid) and nitrogen/sulfur (soft base) elements. These findings convinced that the successful synthesis of Zr(NH2)-DMP provides an option for Hg2+ removal from wastewater. [ABSTRACT FROM AUTHOR]

Ga2O3 nanowires on silicon substrates were synthesized by the chemical vapor deposition method, and the Ga2O3-based metal–semiconductor–metal structured solar-blind photodetector was constructed successfully. Anomalously, the as-constructed photodetector exhibits negative photoconductivity under the illumination from 365 to 645 nm (sub-bandgap excitation) while it shows positive photoconductivity at the 254 nm illumination (super-bandgap excitation), which indicates that the photodetector has a wide spectral response extending to visible light. Under 365 nm illumination, the ratio of dark current to photocurrent, responsivity, and detectivity of the photodetector reach 5570, 0.2 A/W, and 2.52 × 1011 jones, respectively. A possible mechanism is proposed to explain the rare negative photoconductivity phenomenon. Herein, because the negative photoconductivity occurs in sub-bandgap excitations, the photodetector can detect photons whose energy is less than the bandgap of the sample, widening the spectral response. This work provides a method for wide spectrum photodetectors and other negative photoconductivity devices. [ABSTRACT FROM AUTHOR]

By using fluorescein isothiocyanate (FITC) as a Raman probe, we have developed a simple and sensitive method for an immunoassay based on surface-enhanced resonance Raman scattering (SERRS). For the first time, a SERRS-based immunoassay on the bottom of a microtiter plate is reported. We have applied the main pretreatment method of enzyme-linked immunoabsorbent assay (ELISA) to the present study. In this method, SERRS spectra of FITC are measured after several continuous steps of antigen coating, blocking, antibody adding, and colloidal silver staining. Human immunoglobulin G (IgG) and FITC--antihuman IgG are used for the immunoreaction. The proposed method has several advantages for immunoassay. First, we can determine the concentration of antigens via the intensity of a SERRS signal of FITC molecules that are attached to antibodies without an enzyme reaction, and thus the process is simple and reagent saving. Second, one can obtain SERRS spectra of FITC directly from silver aggregates on the bottom of a microtiter plate without displacement. Third, by using SERRS of FITC, the present method is sensitive enough to detect antigens at the concentration of 0.2 ng/mL, which is comparable to ELISA. Results are presented to demonstrate that the proposed SERRS-based immunoassay may have great potential as a high-sensitivity and high-throughout immunoassay.