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Purpose: To evaluate the nephro-protective effect of eupatilin in diabetic nephropathic (DN) rats. Method: Diabetes was induced by intraperitoneal administration of streptozotocin (STZ, 55 mg/kg) and confirmed by fasting blood glucose results, while DN was determined by measuring serum urea and creatinine levels on day 40 after STZ administration. The eupatilin-treated group received eupatilin at 50 and 100 mg/kg, p.o. for 20 days, after which blood levels of some biochemical parameters, glomerulosclerosis index, eosinophilic cast index, and expression of MMP-9 were determined using standard procedures. Results: Treatment with eupatilin significantly decreased serum levels of glucose, creatinine and urea, and increased creatinine clearance, compared to the negative control group. Moreover, eupatilin attenuated changes in kidney histopathology, and significantly enhanced the expression of MMP-9 in the kidney tissues of the DN rats, relative to negative control group. Conclusion: These results indicate that eupatilin attenuates renal failure in STZ-induced DN rats by upregulating the expression of MMP-9. [ABSTRACT FROM AUTHOR]

This work focuses on two main topics about the transmission eigenvalue problem defined on the unit interval [0, 1]: (i) the distributions of transmission eigenvalues in a region Σε which is symmetric about the axes; (ii) the existence of real transmission eigenvalues under some conditions on acoustic profiles n1 (x) and n2 (x). These subjects are central to the so-called qualitative methods for inverse scattering involving penetrable obstacles. Specifically, in the case where n1(x) = n2(x) for x = 0, 1, we show how to locate the transmission eigenvalues in Σ∈. The existence of infinitely many real transmission eigenvalues is proven in the following cases: (i) n2 (0) /n1 (0) ≠ n2 (1) /n1 (1) and n1 (0) n1 (1) ≠ n2 (0) n2 (1) ; (ii) n1 (0) = n2 (0), n1 (1) = n2 (1) and n'1 (1) -- n'2 (1) = n'1 (0) -- n'2 (0). The asymptotics of the real eigenvalues, as the byproduct of their existence, is obtained in both cases. All the results are obtained under the assumptions on the values of ni (x) and n'i (x) for i = 1, 2, x = 0, 1. There are no more restrictions on the values of n1 (x), n2 (x) in the interval (0, 1). [ABSTRACT FROM AUTHOR]

Acidity (pH) plays a key role in the physical and chemical behavior of PM2.5. However, understanding of how specific PM sources impact aerosol pH is rarely considered. Performing source apportionment of PM2.5 allows a unique link of sources pH of aerosol from the polluted city. Hourly water-soluble (WS) ions of PM2.5 were measured online from December 25th, 2014 to June 19th, 2015 in a northern city in China. Five sources were resolved including secondary nitrate (41%), secondary sulfate (26%), coal combustion (14%), mineral dust (11%), and vehicle exhaust (9%). The influence of source contributions to pH was estimated by ISORROPIA-II. The lowest aerosol pH levels were found at low WS-ion levels and then increased with increasing total ion levels, until high ion levels occur, at which point the aerosol becomes more acidic as both sulfate and nitrate increase. Ammonium levels increased nearly linearly with sulfate and nitrate until approximately 20 µg m-3, supporting that the ammonium in the aerosol was more limited by thermodynamics than source limitations, and aerosol pH responded more to the contributions of sources such as dust than levels of sulfate. Commonly used pH indicator ratios were not indicative of the pH estimated using the thermodynamic model. [ABSTRACT FROM AUTHOR]

The growth-controlled zirconia nanocrystals were successfully synthesized via vapor phase hydrolysis without using any capping agents. This method provided the advantage of no high hydrolysis reactivity of precursors. The resultant ZrO2 nanocrystals exhibited the ultrafine nanoscale size of less than 5 nm and a high specific surface area ranging from 400 m² g-1 to 450 m² g-1, which could be well controlled by changing the reaction temperature, the reaction time, or the solvent. [ABSTRACT FROM AUTHOR]

Particle-associated polycyclic aromatic hydrocarbon (PAH) concentrations were investigated at six sampling sites in the heating (February to March 2001) and non-heating (August to September 2001) periods in an industrial city in Northern China. Thirteen PAHs were measured. The total average concentrations (nanograms per meter cubed) of PAHs ranged between 78.93 and 214.63 during the heating period and from 31.48 to 102.26 in the nonheating period. Benzo(a)pyrene occurred at the highest level at a site near an industrial area but occurred at low concentrations far from the city center and industrial areas. In addition, ambient PAH profiles were studied. The five and six-ring species occurred in high fractions at the sampling site. By diagnostic ratio analysis, the major source at each sampling site in the city was coal combustion in the heating period; in the nonheating period, the major sources were relatively complex. Finally, the similarities among the six regions were assessed by principal component analysis, cluster analysis, and coefficient of divergence. These multivariate statistical analyses produced similar results, which agreed with the results from the diagnostic ratio analysis. [ABSTRACT FROM AUTHOR]

Laboratory-based or in situ PM2.5 source profiles may not represent the pollutant composition for the sources in a different study location due to spatially and temporally varying characteristics, such as fuel or crustal element composition, or due to differences in emissions behavior under ambient versus laboratory conditions. In this work, PM2.5 source profiles were estimated for 20 sources using a novel optimization approach that incorporates observed concentrations with source impacts from a chemical transport model (CTM) to capture local pollutant characteristics. Nonlinear optimization was used to minimize the error between source profiles, CTM source impacts, and observations. In a 2006 U.S. application, spatial and seasonal variability was seen for coal combustion, dust, fires, metals processing, and other source profiles when compared to the reference profiles, with variability in species fractions over 400% (calcium in dust) compared to mean contributions of the same species. Revised profiles improved the spatial and temporal bias in modeled concentrations of several trace metal species, including Na, Al, Ca, Mn, Cu, As, Se, Br, and Pb. In an application of the CMB-iteration model for two U.S. cities, revised profiles estimated higher biomass burning and dust impacts for summer compared with previous studies. Source profile optimization can be useful for source apportionment studies that have limited availability of source profile data for the location of interest. [ABSTRACT FROM AUTHOR]

We consider all of the transmission eigenvalues for one-dimensional media. We give some conditions under which complex eigenvalues exist. In the case when the index of refraction is constant, it is shown that all the transmission eigenvalues are real if and only if the index of refraction is an odd number or reciprocal of an odd number. [ABSTRACT FROM AUTHOR]

Water soluble inorganic ions such as ammonium, nitrate, and sulfate are major components of fine aerosols in the atmosphere and are widely used in the estimation of aerosol acidity. However, different experimental practices and instrumentation may lead to uncertainties in ion concentrations. Here, an inter-comparison experiment was conducted in 10 different laboratories (labs) to investigate the consistency of inorganic ion concentrations and resultant aerosol acidity estimates using the same set of aerosol filter samples. The results mostly exhibited good agreement for major ions Cl-, SO42-, NO3-, NH4+ and K+. However, F-, Mg2+ and Ca2+ were observed with more variations across the different labs. The Aerosol Chemical Speciation Monitor (ACSM) data of non-refractory SO42-, NO3-, NH4+ generally correlated very well with the filter analysis based data in our study, but the absolute concentrations differ by up to 42 %. Cl- from the two methods are correlated but the concentration differ by more than 3 times. The analyses of certified reference materials (CRMs) generally showed good recovery of all ions in all the labs, the majority of which ranged between 90 % and 110 %. Better agreements were found for Cl-, SO42-, NO3-, NH4+ and K+ across the labs after their concentrations were corrected with CRM recoveries; the coefficient of variation (CV) of Cl-, SO42-, NO3-, NH4+ and K+ decreased 1.7 %, 3.4 %, 3.4 %, 1.2 % and 2.6 %, respectively, after CRM correction. We found that the ratio of anion to cation equivalent concentrations (AE/CE) is not a good indicator for aerosol acidity estimates, as the results in different labs did not agree well with each other. Ion balance (anions - cations) calculated from SO42-, NO3- and NH4+ gave more consistent results, because of their relatively large concentrations and good agreement among different labs. In situ aerosol pH calculated from the ISORROPIA-II thermodynamic equilibrium model with measured ion and ammonia concentrations showed a similar trend and good agreement across the 10 labs. Our results indicate that although there are important uncertainties in aerosol ion concentration measurements, the estimated aerosol pH from the ISORROPIA-II model is more consistent. [ABSTRACT FROM AUTHOR]