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Resistivity data has important applications in geophysical exploration, but the impact of electrode offsets on resistivity response characteristics remains unclear. This study aims to explore the influence of horizontal electrode offset angles and vertical offsets caused by topographical variations on the forward modeling of resistivity data. By analyzing experimental models with different measurement arrays, the paper revealed their influence laws on the buried depth of the target body and resistivity resolution. Utilizing tools like ZondRes3D, we conducted 3D resistivity forward modeling and analyzed the results in detail. It is found that horizontal electrode offsets lead to pseudo-anomalies in the apparent resistivity response, which is related to the offset angles and the number of electrodes. Under different conditions, the horizontal electrode offsets exhibit a “gradient variation” pattern. In addition, topographical variations can also cause distortions and offsets in the apparent resistivity curves and the locations of the anomaly response. Specifically, the measuring lines near the edge of the target bodies are more susceptible to these effects. Based on the comprehensive experimental results, we have drawn several conclusions regarding the impact of electrode offsets and topographical variations, including the effects of offset angles on the pseudo-anomalies, the anomalous response laws under different topographic conditions, as well as anomalous situations under specific angles. These findings provide crucial insights for interpreting resistivity data in geophysical exploration and addressing practical engineering problems, and offer guidance for optimizing measuring line layouts and post-processing terrain correction algorithms.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting both upper and lower motor neurons (MNs) with large unmet medical needs. Multiple pathological mechanisms are considered to contribute to the progression of ALS, including neuronal oxidative stress and mitochondrial dysfunction. Honokiol (HNK) has been reported to exert therapeutic effects in several neurologic disease models including ischemia stroke, Alzheimer's disease and Parkinson's disease. Here we found that honokiol also exhibited protective effects in ALS disease models both in vitro and in vivo. Honokiol improved the viability of NSC-34 motor neuron-like cells that expressed the mutant G93A SOD1 proteins (SOD1-G93A cells for short). Mechanistical studies revealed that honokiol alleviated cellular oxidative stress by enhancing glutathione (GSH) synthesis and activating the nuclear factor erythroid 2-related factor 2 (NRF2)-antioxidant response element (ARE) pathway. Also, honokiol improved both mitochondrial function and morphology via fine-tuning mitochondrial dynamics in SOD1-G93A cells. Importantly, honokiol extended the lifespan of the SOD1-G93A transgenic mice and improved the motor function. The improvement of antioxidant capacity and mitochondrial function was further confirmed in the spinal cord and gastrocnemius muscle in mice. Overall, honokiol showed promising preclinical potential as a multiple target drug for ALS treatment.

Abstract Background Zika virus (ZIKV) and dengue virus (DENV) cause microcephaly and dengue hemorrhagic fever, respectively, leading to severe problems. No effective antiviral agents are approved against infections of these flaviviruses, calling for the need to develop potent therapeutics. We previously identified gossypol as an effective inhibitor against ZIKV and DENV infections, but this compound is toxic and not suitable for in vivo treatment. Results In this study, we showed that gossypol derivative ST087010 exhibited potent and broad-spectrum in vitro inhibitory activity against infections of at least ten ZIKV strains isolated from different hosts, time periods, and countries, as well as DENV-1-4 serotypes, and significantly reduced cytotoxicity compared to gossypol. It presented broad-spectrum in vivo protective efficacy, protecting ZIKV-infected Ifnar1 −/− mice from lethal challenge, with increased survival and reduced weight loss. Ifnar1 −/− mice treated with this gossypol derivative decreased viral titers in various tissues, including the brain and testis, after infection with ZIKV at different human isolates. Moreover, ST087010 potently blocked ZIKV vertical transmission in pregnant Ifnar1 −/− mice, preventing ZIKV-caused fetal death, and it was safe for pregnant mice and their pups. It also protected DENV-2-challenged Ifnar1 −/− mice against viral replication by reducing the viral titers in the brain, kidney, heart, and sera. Conclusions Overall, our data indicate the potential for further development of this gossypol derivative as an effective and safe broad-spectrum therapeutic agent to treat ZIKV and DENV diseases.

In the present study, a novel method based on solidified floating organic drop microextraction (SFODME) combined with syringe membrane micro-solid phase extraction (SMMSPE) was proposed for the sequential separation and enrichment of Tl(III) and Tl(I) followed by graphite furnace atomic absorption spectrometry detection. In SFODME, Tl(III) can react with 1-(2-Pyridylazo)-2-naphthol at pH 8.0 to form the complexes which can be extracted into an organic drop, while Tl(I) was remained in the solution. In SMMSPE, flexible TiO2@SiO2 nanofiber membrane was used as the sorbent for the enrichment of Tl(I) in the sample solution after the separation of Tl(III). This method did not require tedious pre-oxidation/pre-reduction operation and time-consuming centrifugation/filtration steps, which may cause sample contamination and analysis errors. Main parameters influencing the separation and enrichment of the target species were studied. Under the selected conditions, the detection limits for this method were 1.7 and 2.6 ng/L for Tl(III) and Tl(I) with relative standard deviations of 6.1 % and 5.2 %, respectively. This method was successfully used for the determination of the target species in environmental water samples and two certified reference materials. The determined values were in good agreement with the certified values.

Chromite is a strategic mineral resource for many countries, and chromite deposit occurrences are widespread in the ultramafic rocks of the Yarlung Zangbo ophiolite belt, particularly in the harzburgite unit of the mantle section. Conducting field surveys in complex and poorly accessible terrain is challenging, expensive, and time-consuming. Remote sensing is an advanced method of achieving modern geological work and is a powerful technical means of geological research and mineral exploration. In order to delineate outcrops of chromite-bearing mantle peridotite, the present research study integrates seven image-enhancement techniques, including optimal band combination, decorrelation stretching, band ratio, independent component analysis, principal component analysis, minimum noise fraction, and false color composite, for the interpretation of Landsat8 OLI and WorldView-2 satellite data. This integrated approach allows the effective discrimination of chromite-containing peridotite outcrops in the Luobusa area, Tibet. The interpretation results derived from these integrated image-processing techniques were systematically verified in the field and formed the basis of the feature selection process of different lithologies supported by the support vector machine algorithm. Furthermore, the distribution range of the ferric contamination anomaly is detected through the de-interference abnormal principal component thresholding technique, which shows a high spatial matching relationship with mantle peridotite. This is the first study to utilize Landsat8 OLI and WorldView-2 remote sensing satellite data to explore the largest chromite deposit in China, which enriches the research methods for the chromite deposits in the Luobusa area. Accordingly, the results of this investigation indicate that the integration of information extracted from image-processing algorithms using remote sensing data could be a broadly applicable tool for prospecting chromite ore deposits associated with ophiolitic complexes in mountainous and inaccessible regions such as Tibet’s ophiolitic zones.

At normal operating temperatures (below 100 °C), the water in the proton exchange membrane fuel cell (PEMFC) is in the form of a mixture of gas and liquid phases. The content of water guarantees that the membrane has good proton conductivity, but it may also block the transmission of the reaction gas to the catalytic reaction sites. Based on the single straight channel of the PEMFC, the water content of the model at various voltages and the water distribution of the different parts are studied. The results indicate that the amount of water in the model generally increases with the reduction in the voltage. When the voltage is set from 1.1 V to 0.7 V, the increase in the amplitude of the water content is higher than 0.7 V–0.4 V, and the water content is highest at 0.5 V. Under each voltage, the largest water content occurs in the gas diffusion layer, the second one occurs in the channel, the third one occurs in the proton exchange membrane, and the water content in the catalyst layer is lowest.

Zika virus (ZIKV) infection during pregnancy leads to severe congenital Zika syndrome, which includes microcephaly and other neurological malformations. No therapeutic agents have, so far, been approved for the treatment of ZIKV infection in humans; as such, there is a need for a continuous effort to develop effective and safe antiviral drugs to treat ZIKV-caused diseases. After screening a natural product library, we have herein identified four natural products with anti-ZIKV activity in Vero E6 cells, including gossypol, curcumin, digitonin, and conessine. Except for curcumin, the other three natural products have not been reported before to have anti-ZIKV activity. Among them, gossypol exhibited the strongest inhibitory activity against almost all 10 ZIKV strains tested, including six recent epidemic human strains. The mechanistic study indicated that gossypol could neutralize ZIKV infection by targeting the envelope protein domain III (EDIII) of ZIKV. In contrast, the other natural products inhibited ZIKV infection by targeting the host cell or cell-associated entry and replication stages of ZIKV. A combination of gossypol with any of the three natural products identified in this study, as well as with bortezomib, a previously reported anti-ZIKV compound, exhibited significant combinatorial inhibitory effects against three ZIKV human strains tested. Importantly, gossypol also demonstrated marked potency against all four serotypes of dengue virus (DENV) human strains in vitro. Taken together, this study indicates the potential for further development of these natural products, particularly gossypol, as the lead compound or broad-spectrum inhibitors against ZIKV and other flaviviruses, such as DENV.

Polyporus umbellatus is a well-known and important medicinal fungus in Asia. Its polysaccharides possess interesting bioactivities such as antitumor, antioxidant, hepatoprotective and immunomodulatory effects. A qualitative and quantitative method has been established for the analysis of 12 monosaccharides comprising polysaccharides of Polyporus umbellatus based on high-performance liquid chromatography coupled with electrospray ionization−ion trap−time of flight−mass spectrometry. The hydrolysis conditions of the polysaccharides were optimized by orthogonal design. The results of optimized hydrolysis were as follows: neutral sugars and uronic acids 4 mol/L trifluoroacetic acid (TFA), 6 h, 120 °C; and amino sugars 3 mol/L TFA, 3 h, 100 °C. The resulting monosaccharides derivatized with 1-phenyl-3-methyl-5-pyrazolone have been well separated and analyzed by the established method. Identification of the monosaccharides was carried out by analyzing the mass spectral behaviors and chromatography characteristics of 1-phenyl-3-methyl-5-pyrazolone labeled monosaccharides. The results showed that polysaccharides in Polyporus umbellatus were composed of mannose, glucosamine, rhamnose, ribose, lyxose, erythrose, glucuronic acid, galacturonic acid, glucose, galactose, xylose, and fucose. Quantitative recoveries of these monosaccharides in the samples were in the range of 96.10−103.70%. This method is simple, accurate, and sensitive for the identification and quantification of monosaccharides, and can be applied to the quality control of Polyporusumbellatus as a natural medicine.

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Lamination can greatly enhance the anisotropy and heterogeneity of shale and plays a significant role in influencing hydraulic fracturing. The structure and mechanical difference of different lithofacies lamination are the basis to reveal the fracture propagation mechanism. In this paper, research focused on three continental oil shale with different lithofacies in Qikou sag, Bohai Bay basin, including Quartz-Feldspar dominated shale, Carbonate dominated shale and mixed-mineral shale. Scanning electron microscopy and mineral analysis are used to identify quartz-feldspar lamination and mixture lamination in Quartz-Feldspar dominated shales, as well as carbonate lamination and mixture lamination in Carbonate dominated shales. The distinct laminations with different characteristics were precisely located using FIB, which served as the guiding tool for the indentation experiment. The micromechanical properties of laminations with different lithofacies in oil shale samples are examined using the nanoindentation technique, highlighting their distinct differences. The findings demonstrate that the micromechanical properties of quartz-feldspar lamination in Quartz-Feldspar dominated shales exhibit superior strength, while the mechanical difference between laminations in Quartz-Feldspar dominated shales are significantly larger. The quartz-feldspar lamination exhibits the highest resistance when subjected to indentation force. The mechanical properties of mixture lamination in Quartz-Feldspar dominated shales and Carbonate dominated shales are comparable due to their similar mineral composition. Moreover, in conjunction with macroscopic rock mechanics experiments, it has been verified that the lamination structure facilitates the initiation and propagation of macroscopic fractures under stress loading.

The antioxidant activity of caffeic acid compounds was significantly higher than that of flavonoids, implying that the antioxidant activity was related to the presence of hydroxyl groups, but not be facilitated by the number of hydroxyl groups. The antioxidant activity was associated with the existence of phenolic hydroxyl group [27]: compounds had the antioxidant activity by containing the phenolic hydroxyl group, while they had no antioxidant activity due to the lack of a phenolic hydroxyl structure. The antioxidant activity of caffeoylquinic acid compounds could be ranked as follows: 3,4-Dicaffeoylquinic acid > 1,5Dicaffeoylquinicacid > 3,5-Dicaffeoylquinic acid, indicating that the substitution position of caffeoyl on quinic acid had a greater influence on DPPH activity. [Extracted from the article]

Background: Chromium is an interesting element because its toxicity depends on its speciation. Thus, knowledge of Cr speciation in cow milk is essential to human health. Objective: This study aims to achieve real bioaccessible species in cow milk, including Cr(III), Cr(VI), residual, digestible, and total Cr. Methods: Samples were treated with artificial gastric juice, followed by dispersive micro-solid phase extraction (DMSPE) combined with ICP-MS for Cr speciation. Fibrous g-C3N4@Tio2 nanocomposites (FGCTNCs) were used as a novel adsorbent for DMSPE. Results: The method detection limits were 110 pg/g (Cr(III)) and 260 pg/g (Cr(VI)) for milk powder (0.1 g), and 5.1 pg/g (Cr(III)) and 13 pg/g (Cr(VI)) for liquid cow milk (2 mL). The relative standard deviations (RSDs), obtained by analyzing the standard solutions containing 1.0 ng/mL of the analytes in sequence for nine times, were 4.3% and 5.1% for Cr(III) and Cr(VI), respectively. Linearity was observed over the range of 4 magnitude orders with correlation coefficients better than 0.9961. The enrichment factor of 100 was obtained. The majority of Cr in the samples was transferred into digestion solution. The content of Cr(III) is much higher than that of Cr(VI) in the digestion solution. Conclusions: This method has the advantages of reduced solvent consumption, less adsorbent dosage, and high extraction efficiency. It may become a valuable strategy for elemental species in food samples. Highlights: The samples were treated with artificial gastric juice to avoid the inter-conversion of species. FGCTNCs exhibit the merits of N-rich functional groups and selective adsorption for the analytes. [ABSTRACT FROM AUTHOR]

To evaluate the quality of Polyporus umbellatus, we established a simple, repeatable and reliable method based on high performance liquid chromatography (HPLC) for specific chromatogram and fingerprint analysis, which was applied to analyze samples of medicinal materials and decoction pieces collected from different regions. Finally, ten characteristic peaks were designated in the specific chromatograms and applied to the authenticate identification of P. umbellatus samples. Nine common peaks were designated in the fingerprints, and then the similarities between 32 batches of samples were calculated. Among them, eight compounds were identified by HPLC-APCI-IT-TOF-MSn, four of which were identified in specific chromatograms and four in fingerprints. In the present study, we, for the first time, combined HPLC specific chromatograms and fingerprints for the species identification and quality evaluation of P. umbellatus. Collectively, our findings provided a new method for establishing a comprehensive quality standard of P. umbellatus. [ABSTRACT FROM AUTHOR]

Fufang Banbianlian Injection (FBI) is a well-known traditional Chinese medicine formula composed of three herbal medicines. However, the systematic investigation on its chemical components has not been reported yet. In this study, a high-performance liquid chromatography combined with diode-array detector, and coupled to an electrospray ionization with ion-trap time-of-flight mass spectrometry (HPLC-DAD-ESI-IT-TOF-MS) method, was established for the identification of chemical profile in FBI. Sixty-six major constituents (14 phenolic acids, 14 iridoids, 20 flavonoids, 2 benzylide-neacetone compounds, 3 phenylethanoid glycosides, 1 coumarin, 1 lignan, 3 nucleosides, 1 amino acids, 1 monosaccharides, 2 oligosaccharides, 3 alduronic acids and citric acid) were identified or tentatively characterized by comparing their retention times and MS spectra with those of standards or literature data. Finally, all constituents were further assigned in the individual herbs (InHs), although some of them were from multiple InHs. As a result, 11 compounds were from Lobelia chinensis Lour, 33 compounds were from Scutellaria barbata D. Don and 38 compounds were from Hedyotis diffusa Willd. In conclusion, the developed HPLC-DAD-ESI-IT-TOF-MS method is a rapid and efficient technique for analysis of FBI sample, and could be a valuable method for the further study on the quality control of the FBI. [ABSTRACT FROM AUTHOR]

In this paper, a symplectic method for structurepreserving modelling of the damped acoustic wave equation is introduced. The equation is traditionally solved using non-symplectic schemes. However, these schemes corrupt some intrinsic properties of the equation such as the conservation of both precision and the damping property in long-term calculations. In the method presented, an explicit second-order symplectic scheme is used for the time discretization, whereas physical space is discretized by the discrete singular convolution differentiator. The performance of the proposed scheme has been tested and verified using numerical simulations of the attenuating scalar seismic-wave equation. Scalar seismic wavefield modelling experiments on a heterogeneous medium with both damping and high-parameter contrasts demonstrate the superior performance of the approach presented for suppression of numerical dispersion. Long-term computational experiments display the remarkable capability of the approach presented for long-time simulations of damped acoustic wave equations. Promising numerical results suggest that the approach is suitable for highprecision and long-time numerical simulations of wave equations with damping terms, as it has a structure-preserving property for the damping term. [ABSTRACT FROM AUTHOR]

Microcolumn packed single-walled carbon nanotubes (SWCNTs) were used as solid phase extraction adsorbent for chromium speciation coupled to inductively coupled plasma mass spectrometry for detection. The effects of the experimental parameters, including pH of the solution, sample flow rate, volume and concentration of eluent, sample volume and interfering ions, on separation and determination of Cr(III) and Cr(VI) were investigated in detail. It was found that Cr(III) was selectively sorbed on the microcolumn packed with SWCNTs in the pH range from 2.0 to 4.0, while Cr(VI) remained in solution. The retained Cr(III) was subsequently eluted with 2.0 mL of 1.2 mol L−1 nitric acid. Under the optimum conditions, the detection limits based on 3σ criterion were 0.01 ng mL−1 and 0.024 ng mL−1 for Cr(III) and Cr(VI), respectively. The relative standard deviations were less than 5.0% ( n = 9, c = 1.0 ng mL−1). The method was successfully applied to the speciation of chromium in real samples including natural and waste water. The recoveries of spiked samples were higher than 92.5%. [ABSTRACT FROM AUTHOR]

Three new isoflavonoids, namely ±ammopiptanine A 1, ammopiptanine B 2, ammopiptanoside A 3, together with 13 known compounds, were isolated from the aerial parts of Ammopiptanthus mongolicus.Their structures were elucidated on the basis of detailed spectroscopic analyses and by comparison with those of related model compounds. The isoflavonoids described, except formononetin, wistin, daidzein, and calycosin, were isolated from this plant for the first time. [ABSTRACT FROM AUTHOR]

The article reports on the development of a procedure for determination of trace elements in muscle tissue of hairtail using inductively coupled plasma-atomic emission spectrometry and electrothermal vaporization with slurry sampling. During the process, polytetrafluoroethylene was utilized as the chemical modifier to convert the analytes into the fluorides with various volatilities at a high temperature of the graphite furnace for the improvement of the analytical performance.

In this article, a polytetrafluoroethylene (PTFE) slurry was used as a chemical modifier for direct determination of trace elements in environmental samples by electrothermal vaporization inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES) with slurry sampling. The vaporization behaviors of the analytes in slurry and solution were comparatively studied in the presence of PTFE. The main influence factors for this method were examined. Under the optimum operating conditions, the precision of this method was better than 7% with the detection limits varying from 1.7 ng mL -1 (Cu) to 203 ng mL -1 (Zn). The proposed method has been applied to the direct determination of the trace elements in camphor tree leaves and standard reference material (the combined sample of branch and leaf of shrub, GBW 07603) with satisfactory results. [ABSTRACT FROM AUTHOR]

Focuses on a several geological, geochemical and genetic studies of the Yuxi silver deposit in east Tianshan, Xianjiang Autonomous Region, China. Geology of the Yuxi silver deposit; Characteristics of the deposit; Genesis of the deposit; Conclusion.