No abstract

Application of matrix-assisted laser desorption/ionization imaging mass spectrometry to microbiology and natural product research has opened the door to the exploration of microbial interactions and the consequent discovery of new natural products and their functions in the interactions. However, several drawbacks of matrix-assisted laser desorption/ionization imaging mass spectrometry have limited its application especially to complicated and uneven microbial samples. Here, we applied nanostructured silicon as a substrate for surface-assisted laser desorption/ionization mass spectrometry for microbial imaging mass spectrometry to explore fungal metabolic interactions. We chose Phellinus noxius and Aspergillus strains to evaluate the potential of microbial imaging mass spectrometry on nanostructured silicon because both fungi produce a dense mass of aerial mycelia, which is known to complicate the collection of high-quality imaging mass spectrometry data. Our simple and straightforward sample imprinting method and low background interference resulted in an efficient analysis of small metabolites from the complex microbial interaction samples.

This study investigated the treatment in the constructed Wuluo wetland, Taiwan, of 13 veterinary antibiotics, including five classes (tetracyclines, sulfonimides, chloramphenicol, fluoroquinolone, and dyes), five alkylphenolic compounds (nonylphenol di-ethoxylates [NP2EO], nonylphenol mono-ethoxylates [NP1EO], nonylphenol [NP], octylphenol [OP], and bisphenol A [BPA]), and three estrogens (17β-estradiol [E2], estriol [E3], and 17α-ethynylestradiol [EE2]). The veterinary antibiotics oxytetracycline (OTC), ciprofloxacin (CIP), chloramphenicol (CAP), oxolinic acid (OXO), sulfamonomethoxine (SMM), and sulfadimethoxine (SDM) were detected in 7.1-96.4% of samples with concentrations varying widely from not detected to 552 ng/L. Removal efficiencies within different units of the wetland system exceeded 87% for OTC, CAP, SMM, and SDM, excluding those for IP and OXO, which were 72.1% and 43%, respectively. The other seven antibiotics (tetracycline [TC], enrofloxacin [ENR], chlortetracycline [CTC], sulfamerazine [SMR], sulfamethazine [SMZ], malachite green [MG], and leucomalachite green [LMG]) were all below detection limits in all samples. Additionally, detection rates were as follows: NP1EO, 70.0%; NP2EO, 70.0%; 4-n-NP, 72.9%; 4-OP, 50.0%; BPA, 81.3%; E2, 52.1%; E3, 57.1%; and EE2, 31.3%. Concentrations of the alkylphenolic compounds were as follows: NP1EO, ND-1092.7; NP2EO, ND-643.7; 4-n-NP, ND-6812.3; 4-OP, ND-10400.1; and BPA, ND-1733 ng/L. Natural and synthetic estrogens E2, E3, and EE2 in samples were found in the ranges of ND-907.4, ND-749.5, and ND-226.0 ng/L, respectively. Analytical results show that with the exception of EE2 throughout the wetland system, target compounds were largely removed.

Amorphous silicon solar cell is one of the most well developed solar energy solutions. In order to increase the energy conversion efficiency, light-trapping is necessary to the cell structure. Light trapping can be achieved by a textured transparent conducting oxide ͑TCO͒ layer and one of the critical factors of textured TCO is its haze value, which characterizes the scattering capability of the TCO. Recently several highly textured TCOs were presented with high haze at near IR region, where the haze of textured interfaces traditionally suffered from reduced scattering. However, suitable modeling is not established yet. In this work, we use scalar scattering theory and Kirchhoff approximation to solve haze value of complex surfaces analytically. Different from original Rayleigh scattering expression, this model illustrates intricacy between the surface roughness, correlation length, and the separation between different groups of height distributions. The resulting analytical formulation can be applied successfully not only in regular monotonically decaying spectral hazes but also various nonmonotonically shaped ones, meanwhile it retains important physical factors which can be useful for process evaluation.

Mesoporous HZSM-5 prepared by alkaline treatment (also termed desilication) has drawn significant attention due to its potential in large-scale production and in versatile applications, such as separation and catalysis. Alkali-treated HZSM-5 contains considerable amounts of non-framework (amorphous) Lewis acidic Al species on the external surface, and is deemed to be essential in affecting its catalytic performances. This study intends to clarify the catalytic nature of amorphous Al species of alkali-treated HZSM-5 in methanol aromatization. Physicochemical characterizations, including N 2 adsorption, scanning electron microscopy (SEM), X-ray diffraction (XRD), magic-angle-spinning nuclear magnetic resonance (MAS NMR), inductively coupled plasma (ICP) analysis, NH 3 temperature-programmed desorption (TPD), and methanol-TPD, were performed. The outcomes showed that non-framework Al promotes the hydride transfer in mesoporous HZSM-5, thereby facilitating the aromatization reaction. Among aromatic products, durene can be promoted by non-framework Al through methylation/transalkylation of other aromatics, particularly xylenes, instead of being promoted by reduced space confinement in mesoporous HZSM-5.