Potential Regulation for Surface-Enhanced Raman Scattering Detection and Identification of Carotenoids

Surface-enhanced Raman scattering (SERS) is often impaired by the limited affinity of molecules to plasmonic substrates. Here, we use carbon fiber microelectrodes modified with silver nanoparticles as a plasmonic microsubstrate with tunable affinity for enrichment and molecular identification by SERS. The silver nanoparticles self-assemble by electrostatic interaction with diamine molecules that are electrochemically grafted onto the surface of the microelectrodes. β-carotene and trans-β-Apo-8′-carotenal, producing similar resonant SERS spectra, are employed as model molecules to study the effect of electroenrichment and SERS screening for different electrode potentials. The data show that at a characteristic electrode potential, the low affinity of polyene chains without hydrophilic groups to the substrate can be overcome. Different potentials were applied to recognize the two types of carotenoids by their typical SERS signal, and the applicability of this strategy was further confirmed in the environment of a real cell culture. The results indicate that by regulating the potential, carotenoid molecules with a similar molecular structure can be selectively quantified and identified by SERS. The developed SERS-active microelectrode is expected to help the development of portable, miniaturized point-of-care diagnostic SERS sensors

Electrodeposition of Silver Nanostructures in Ethanol for Sensitive Electrochemical SERS Detection

Surface-enhanced Raman scattering (SERS) detection and characterization upon enrichment of analyte molecules can provide an efficient means of identifying toxic species in complex matrices. We demonstrate the electrodeposition of silver nanostructures on a carbon fiber microelectrode (CFME) in an organic solvent electrolyte, addressing the need for controllable electrodeposition of silver nanoparticles on carbon fiber surfaces. It results in a plasmonic silver microelectrode (CFME-dAg) with favorable properties for electroenrichment and optical detection, without the necessity of using linker molecules to graft presynthesized silver nanostructures onto the CFME. Compared to the electrodeposition of silver nanostructures in aqueous phase, this strategy yields particles of relatively uniform size, small dimensions, and high density. The miniaturized SERS sensor platform was used for the detection of trans-β-Apo-8′-carotenal, a toxic cleavage product of β-carotene, with limits of detection in the nanomolar range. The possibility to tune the potential was applied to selectively enrich the analyte before a molecular background of a typical cellular environment of a culture medium, including proteins, amino acids, and similarly structured carotenoids

Laccase and Xylanase Incubation Enhanced the Sulfomethylation Reactivity of Alkali Lignin

Alkali lignin (AL), from poplar alkali pulping process, was activated by laccase and laccase/xylanase system (LXS). When incubated with 10 U/g laccase for 24 h, the sulfomethylation reactivity of AL could increase by 33%. The functional group content and 1H NMR analysis showed that the cleavage of various ether linkages and demethylation, resulting in the increase of phenolic groups and decrease of steric hindrance, contributed to the improvement of sulfomethylation reactivity. Xylanase addition could increase the laccase incubation rate. Bonds between lignin–carbohydrate complexes (LCCs) were disrupted with the addition of xylanase. Hence, AL was more accessible to laccase, leading to a higher incubation rate. Due to the increased reactivity, the dispersion performance of sulfomethylated lignin on TiO2 slurry was obviously improved

Horseradish Peroxidase Modification of Sulfomethylated Wheat Straw Alkali Lignin To Improve Its Dispersion Performance

Wheat straw alkali lignin (WAL), byproducts from the alkali pulping process, is a low-value product with poor water solubility and limited dispersion performance. Sulfomethylated wheat straw alkali lignin (SWAL) was first prepared by sulfomethylation. In order to further improve the dispersion performance of WAL, a commercially available horseradish peroxidase (HRP) was then used to modify SWAL. Gel permeation chromatography showed an obvious increase in molecular weight after HRP modification by approximately 6 fold and 18 fold, compared with SWAL and WAL, respectively. The structural characterization was investigated by functional group content measurements and IR and ¹H NMR analyses. After the HRP modification, the phenolic and methoxyl group content decreased, while the sulfonic and carboxyl group content increased. Because of the higher molecular weight and hydrophilic group content, the HRP modification induced a significant improvement in adsorption and dispersion performance of WAL

Data_Sheet_1_A Novel Two-Stage Refine Filtering Method for EEG-Based Motor Imagery Classification.PDF

Cerebral stroke is a common disease across the world, and it is a promising method to recognize the intention of stroke patients with the help of brain–computer interface (BCI). In the field of motor imagery (MI) classification, appropriate filtering is vital for feature extracting of electroencephalogram (EEG) signals and consequently influences the accuracy of MI classification. In this case, a novel two-stage refine filtering method was proposed, inspired by Gradient-weighted Class Activation Mapping (Grad-CAM), which uses the gradients of any target concept flowing into the final convolutional layer to highlight the important part of training data for predicting the concept. In the first stage, MI classification was carried out and then the frequency band to be filtered was calculated according to the Grad-CAM of the MI classification results. In the second stage, EEG was filtered and classified for a higher classification accuracy. To evaluate the filtering effect, this method was applied to the multi-branch neural network proposed in our previous work. Experiment results revealed that the proposed method reached state-of-the-art classification kappa value levels and acquired at least 3% higher kappa values than other methods This study also proposed some promising application scenarios with this filtering method.</p

SPORL Pretreatment Spent Liquors Enhance the Enzymatic Hydrolysis of Cellulose and Ethanol Production from Glucose

This study investigated the recycle utilization of SPORL pretreatment spent liquor. Three lignosulfonates (LSs) were purified from the spent liquor of SPORL pretreated Beetle-killed lodgepole pine (BKLP), Poplar NE222 (NE222), and Douglas-fir (FS10). The structural characterization showed that the apparent molecular mass and sulfur content of NE222-LS were lowest, but the phenolic group content was highest. FS10-LS, from a pH profiling SPORL pretreatment, had the highest apparent molecular mass but medium sulfur and phenolic group content. The spectral analyses exhibited that the guaiacyl unit was the main structure in BKLP and FS10 LSs, while NE222-LS mainly contained both guaiacyl and syringyl units. Both LSs and SPORL pretreatment spent liquors were used as additives to enzymatic hydrolysis of Whatman paper and ethanol production from glucose. LSs and liquors, from SPORL pretreated BKLP and NE222, could obviously enhance the enzymatic saccharification. Nevertheless, LS and liquor from SPORL pretreated FS10 presented a slight negative effect on enzymatic saccharification. All LSs and liquors with low concentration exhibited no inhibition on ethanol fermentation from glucose. When whole spent liquors without any detoxification were applied to prepare the fermentation medium with an initial glucose concentration of 100 g/L, the ethanol yield was almost the same as the control for BKLP and FS10 liquors. Nevertheless, the whole NE222 liquor without detoxification inhibited ethanol production thoroughly

Role of Trade in India’s Rising Atmospheric Mercury Emissions

India is among the largest emitters of atmospheric mercury (Hg) in the world. India’s production activities have associated Hg emissions which can be attributed to final demands (e.g., purchases by households, governments, and private investments) of nations driving upstream production from the demand perspective, or primary inputs (e.g., labor and capital supply) of nations enabling downstream production from the supply perspective. This study identifies key nations and sectors that directly and indirectly drove India’s Hg emissions from both the demand and supply perspectives during 2004–2014. While domestic final demand was the dominant driver from the demand perspective (driving about 80–85% of the total), USA, China, and UAE are important foreign drivers. Similarly, from the supply perspective, domestic primary inputs were the dominant drivers. However, the share of foreign inputs enabling Hg emissions increased from 16 to 23% during the decade. Saudi Arabia, Indonesia, Australia, and China are the top foreign supply-side drivers. The Construction sector is an important demand-side driver, whereas fossil fuel sectors are important supply-side drivers. These findings can guide global and national policies for demand- and supply-side management of Hg emissions in India and assist in the successful implementation of the Minamata Convention on Mercury

DataSheet1_Synthesis, biological evaluation, and molecular docking of novel hydroxyzine derivatives as potential AR antagonists.PDF

Prostate cancer (PCa) is a malignant tumor with a higher mortality rate in the male reproductive system. In this study, the hydroxyazine derivatives were synthesized with different structure from traditional anti-prostate cancer drugs. In the evaluation of in vitro cytotoxicity and antagonistic activity of PC-3, LNCaP, DU145 and androgen receptor, it was found that the mono-substituted derivatives on the phenyl group (4, 6, 7, and 9) displayed strong cytotoxic activities, and compounds 11–16 showed relatively strong antagonistic potency against AR (Inhibition% >55). Docking analysis showed that compounds 11 and 12 mainly bind to AR receptor through hydrogen bonds and hydrophobic bonds, and the structure-activity relationship was discussed based on activity data. These results suggested that these compounds may have instructive implications for drug structural modification in prostate cancer.</p

Consumption in Non-Pastoral Regions Drove Three-Quarters of Forage–Livestock Conflicts in China

Forage–livestock conflict (FLC) is a major anthropogenic cause of rangeland degradation. It poses tremendous threats to the environment owing to its adverse impacts on carbon sequestration, water supply and regulation, and biodiversity conservation. Existing policy interventions focus on the in situ FLCs induced by local production activities but overlook the role of consumption activities in driving FLCs. Here, we investigate the spatiotemporal variations in China’s FLCs and the domestic final consumers at the county level by combining remote sensing data and multi-regional input–output model. Results show that during 2005–2015, China’s pastoralism induced an average of 82 million tons of FLCs per year. Domestic final demand was responsible for 85–93% of the FLCs in China. There was spatiotemporal heterogeneity in domestic consumption driving China’s FLCs. In particular, the final demand of non-pastoral regions was responsible for around three-quarters (74–79%) of the total FLCs throughout the decade. The rangeland-based livestock raising, agricultural and sideline product processing, and catering sectors are important demand-side drivers. These findings can support targeted demand-side strategies and interregional cooperation to reduce China’s FLCs, thus mitigating rangeland degradation