Synthesis of AuAg/Ag/Au open nanoshells with optimized magnetic plasmon resonance and broken symmetry for enhancing second-harmonic generation.

The cooperation of magnetic and electric plasmon resonances in cup-shaped metallic nanostructures exhibits significant capability for second-harmonic generation (SHG) enhancement. Herein, we report an approach for synthesizing Au open nanoshells with tunable numbers and sizes of openings on a template of six-pointed PbS nanostars. The morphology of Au nanoshells is controlled by adjusting the amount of HAuCl4, and the characteristic shapes of pointed nanocaps, open nanoshells, and hollow nanostars are obtained. Owing to the collaboration of electric and magnetic plasmon resonance modes, the Au nanoshells exhibit significantly broadened and highly tunable optical responses. Furthermore, the morphology-dependent SHG of the Au nanoshells shows two maximal SHG intensities, corresponding to four-opening and one-opening Au nanoshells with appropriate opening sizes. Ag/Au and AuAg/Ag/Au open nanoshells were further investigated to achieve enhanced SHG. By adjusting the thickness of the Ag shell, the SHG intensity of Ag/Au open nanoshells reaches a maximum due to the gradient field at the AuAg bimetallic interface. After replacing the Ag shells with Au shells, the SHG intensity of AuAg/Ag/Au open nanoshells reaches a maximum due to further symmetry breaking. These findings provide a strategy to prepare colloidal metal nanocrystals with prospective applications ranging from nonlinear photonic nanodevices to biospectroscopy and photocatalysis.

Toll-like Receptor 4 Signaling Pathway in the Protective Effect of Pioglitazone on Experimental Immunoglobulin A Nephropathy.

BACKGROUND: In vitro experiments have revealed that toll-like receptor 4 (TLR4) pathway is involved in the progression of immunoglobulin A nephropathy (IgAN) by induction of proinflammatory cytokines. Evidence showed that, in other disease models, peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists have been shown to exert anti-inflammatory effects through suppression of the expression and activity of TLR4. However, the interaction between PPAR-γ and TLR4 in IgAN has not been fully studied both in vitro and in vivo. In this study, we explored whether TLR4 pathway attributed to the progression of IgAN in experimental rats. METHODS: Bovine gamma globulin was used to establish IgAN model. Fifty-four Lewis rats were randomly divided into six groups: ControlTAK242, IgANTAK242, toll-like receptor 4 inhibitor (TAK242) groups (rats were administrated with TLR4 inhibitor, TAK242) and ControlPio, IgANPio, Pio groups (rats were administrated with PPAR-γ agonist, pioglitazone). Urinary albumin-to-creatinine ratio (ACR), serum creatinine, and blood urea nitrogen were detected by automatic biochemical analyzer. Renal histopathological changes were observed after hematoxylin-eosin staining, and the IgA deposition in glomeruli was measured by immunofluorescence staining. Real-time polymerase chain reaction and Western blotting were used to detect TLR4 and interleukin-1 beta (IL-1ß) message ribonucleic acid (mRNA) and protein expression in renal tissues. Results were presented as mean ± standard deviation. Differences between groups were analyzed by one-way analysis of variance. RESULTS: Compared to normal rats, experimental rats showed higher ACR (4.45 ± 1.33 mg/mmol vs. 2.89 ± 0.96 mg/mmol, P < 0.05), obvious IgA deposition with mesangial hypercellularity, hyperplasia of mesangial matrix accompanied by increased serum IL-1ß (48.28 ± 13.49 pg/ml vs. 35.56 ± 7.41pg/ml, P < 0.05), and renal expression of IL-1ß and TLR4. The biochemical parameters and renal pathological injury were relieved in both TAK242 group and Pio group. The expressions of renal tissue TLR4, IL-1ß, and serum IL-1ß were decreased in rats treated with TAK242, and the expression of TLR4 mRNA and protein was significantly reduced in Pio group compared to IgANPiogroup (1.22 ± 0.28 vs. 1.72 ± 0.45, P < 0.01, and 0.12 ± 0.03 vs. 0.21 ± 0.05, P < 0.01). CONCLUSIONS: Our study proves that inflammation mediated by TLR4 signaling pathway is involved in the progression of IgAN in rat models. Moreover, pioglitazone can inhibit the expression of TLR4 in IgAN.

[Characteristic Study on the "Weekend Effect" of Atmospheric O3 in Northern Suburb of Nanjing].

The data of ozone (O3) and its precursors (NOx, CO, VOCs) observed at northern suburb of Nanjing from December 01, 2013 to November 30, 2014 were used to analyze the difference of pollutant concentrations on weekends and weekdays, and its causes. The results showed that there was an obvious "Weekend Effect" in northern suburb of Nanjing. The mass concentrations of O3 on weekdays were higher than those on weekends, whereas mass concentrations of its precursors were higher on the weekends; The average mass concentrations of O3 were 19.84 µg·m-3, 53.45 µg·m-3, 57.17 µg·m-3, and 40.43 µg·m-3 in winter, spring, summer, and autumn respectively. Compared with other seasons, "Weekend Effect " was more distinct in spring. The value of NO2/NO was 4.81% higher on weekdays (3.63) than on weekends (3.46). The longer cumulative time and higher accumulation rate of O3, and the stronger atmospheric oxidation capacity on weekdays were responsible for the higher O3 mass concentrations on weekdays. The correlation coefficients of the mass concentrations of O3 with VOCs, NOx, NO, and NO2 were higher on weekdays than on weekends.

[Characteristics and Source Apportionment of Water-soluble Ions in Dry Deposition in the Summer and Autumn of Nanjing].

A total of 84 effective dry deposition samples were collected from July to October, 2014 in Nanjing, and the chemical composition and source apportionment of water-soluble ions dry deposition in the summer and autumn season were discussed. The results indicated that the average pH was 6.2, and the dry deposition samples usually appeared neutral. Ca2+ and NH4+ were the major cations and their average daily concentrations were 115.7 µeq·L-1 and 31.2 µeq·L-1,accounting for 68.3% and 18.6% of total cations, respectively. SO42-, Cl- and NO32- were the main anions, and their average daily concentrations were 30.4, 20.7 and 18.7 µeq·L-1, a total of 89.2% of the total anions, respectively. High temperature and humidity of meteorological factors and contaminated air mass affected dry deposition. Local air mass had greater impact on dry deposition pollution, which indicated that dry deposition pollution had local property. In summer and autumn seasons in Nanjing, the stationary sources had more contributions to atmospheric dry deposition of water-soluble ions than mobile sources, while the environmental control measures for the Nanjing Youth Olympic Games had greater effect on stationary sources than mobile sources. Studies of the origins of major ions indicated that SO42- and NO32- were mostly attributed by the anthropogenic activities, and Cl- was mainly from ocean sources, while K+ and Mg2+ were mostly from the terrestrial input.

[Distribution Characteristics of Water Soluble Ions Under Different Weather Conditions During the Youth Olympic Games in Nanjing].

To study the variation characteristics of water soluble ions during youth Olympic Games, PM2.5 and water soluble ions were observed by using the beta dust instrument, Anderson 9th sampler and IC type ion chromatography analyzer from August 6 to September 4, 2014. The observations were divided into three types of weather, sunny, rainy and cloudy. The average concentrations of PM2.5 under different weather conditions were sunny > cloudy > rainy days. The concentrations of water soluble ions in PM1.1, PM1.1-2.1 and PM2.1-10 were also sunny > cloudy > rainy days, and the obliterate of fine particles by precipitation process was more obvious. The spectra of Ca2+ and Mg2+ were bimodal. The scavenging effects of SO42- and NH4+ in range of 0.65-1.1 µm were stronger. The ratio of NO3-/SO42- under different weather conditions was less than 1, and the ratio of NO3-/SO42- in rainy and cloudy days was higher than that in sunny days. The values of SOR and NOR in the three kinds of weather conditions were more than 0.1, SO2 and NO2 had different degrees of transformation, there was more secondary pollutant in the atmosphere.

[Size distribution and characterization of OC and EC in atmospheric aerosols during the Asian Youth Games of Nanjing, China].

Aerosol samples were collected by an Andersen cascade impactor (Andersen) in Nanjing during the Asian Youth Games (AYG), and organic carbon (OC) and elemental carbon (EC) in particles were determined by DRI Model 2001A carbon analyzer of USA. Observations indicated that OC (51.55%) and EC (54. 81%) were enriched in the fine aerosol particles with size below 1. 1 µm, the highest mass concentrations of OC and EC were located at 0-0.43 µm and 0.43-0.65 µm, respectively, accounting for 20. 90% ±5.02% and 22. 68% ±9.90% of the total concentration. The mass concentrations of OC and EC in PM1.1, PM1.1-2.1 and PM(2.1-10) during AYG period were decreased by 43. 44% -56. 17% and 59. 17% -73.55% as compared to the values before AYG. The spectral distribution of OC was bimodal during the whole observation period, while the spectrum distribution of EC was changed from bimodal to unimodal. OC and EC during the observation period were in good homology. OC and EC were attributed to automobile exhaust fumes before AYG. During AYG, OC and EC in PM1.1 were mostly from automobile exhaust fumes, while OC and EC in PM1.1-2.1 and PM2.1-10 were from automobile exhaust fumes and coal combustion.

[Distribution characteristics of pollution gases and water soluble ion in aerosol during the Asian Youth Games of Nanjing, China].

Water soluble ions were observed by an Andersen cascade impactor (Andersen) and ion chromatography in Nanjing during the Asian Youth Games (AYG), and PM2.5, NO, NO2, O3 and CO were observed by ray ß dust instrument, EMS pollution gases monitoring system. Concentrations of PM2.5, NO2, O3 and CO, were 37.0, 19.3, 48.1 and 0.7 x 10(3) µg x m(-3) during the AYG period, 26.0%, 42.6%, 36.1% and 46.1% lower than the value before the AYG period. During the AYG period, the main water-soluble ions in PM2.1 were Na(+), NH4(+) , Ca(2+) and SO4(2-), accounting for 80.6%; the main water-soluble ions in PM2.1-10 were Na(+), Ca(2+), NO3(-) and SO4(2-), accounting for 77.9%. The spectral distribution of Ca(2+), Mg(2+) and NO3(-) were bimodal during the AYG period, other ions were three models. Before and after the AYG period, all ions were three models. From NO3(-)/SO4(2-), we can judge SO2 and NO(x) mainly come from the mobile source before and after the AYG period, from stationary sources during the AYG period.