HCCDB v2.0: Decompose Expression Variations by Single-cell RNA-seq and Spatial Transcriptomics in HCC.

Large-scale transcriptomic data are crucial for understanding the molecular features of hepatocellular carcinoma (HCC). Integrated 15 transcriptomic datasets of HCC clinical samples, the first version of HCC database (HCCDB v1.0) was released in 2018. Through the meta-analysis of differentially expressed genes and prognosis-related genes across multiple datasets, it provides a systematic view of the altered biological processes and the inter-patient heterogeneities of HCC with high reproducibility and robustness. With four years having passed, the database now needs integration of recently published datasets. Furthermore, the latest single-cell and spatial transcriptomics have provided a great opportunity to decipher complex gene expression variations at the cellular level with spatial architecture. Here, we present HCCDB v2.0, an updated version that combines bulk, single-cell, and spatial transcriptomic data of HCC clinical samples. It dramatically expands the bulk sample size by adding 1656 new samples from 11 datasets to the existing 3917 samples, thereby enhancing the reliability of transcriptomic meta-analysis. A total of 182,832 cells and 69,352 spatial spots are added to the single-cell and spatial transcriptomics sections, respectively. A novel single-cell level and 2-dimension (sc-2D) metric is proposed as well to summarize cell type-specific and dysregulated gene expression patterns. Results are all graphically visualized in our online portal, allowing users to easily retrieve data through a user-friendly interface and navigate between different views. With extensive clinical phenotypes and transcriptomic data in the database, we show two applications for identifying prognosis-associated cells and tumor microenvironment. HCCDB v2.0 is available at http://lifeome.net/database/hccdb2.

Strategies and mechanisms for improving the detection accuracy of nonextractable residues of polycyclic aromatic hydrocarbons in soils.

The methods that can accurately measure the concentrations of nonextractable residues (NERs) of hydrophobic organic contaminants (HOCs) in soil are still lacked in current studies. In this study, three methods, namely methanolic saponification treatment (MST), silylation treatment (ST), and acid deashing treatment (ADT), were investigated and then combined to extract the NERs of six types of polycyclic aromatic hydrocarbons (PAHs) from nine soil samples. The NER concentrations of PAHs obtained by ST (2.43-521.73 ng g-1) were comparable to or significantly higher than those obtained by MST (1.94-291.54 ng g-1), owing to the properties of soil and target compounds. Additionally, ADT could further release a considerable amount of PAH NERs (0.39-276.99 ng g-1) from the soils that had been treated with ST. The mechanism was that acid solution dissolved mineral components, significantly increasing the pore size of the soil matrices from 9.37-15.57 nm to 17.11-27.51 nm. The average percentage of each PAH obtained by ADT (the ratio of the amount obtained by ADT to the total NER content) exhibited a negative correlation with their ring numbers (R2 = 0.62, p < 0.05), whereas the percentage of targets recovered through ST increased linearly with their log KOW values (R2 = 0.75, p < 0.05). Moreover, there is a positive correlation (R2 = 0.73, p < 0.05) between the NER percentages of phenanthrene (obtained by ST-ADT) and the specific surface areas of soils, and the NER percentages of benzo(g,h,i)perylene is positively correlated to the content of total organic carbon (R2 = 0.62, p < 0.05). These results suggested that the amounts and locations of NERs were influenced by both the physicochemical characteristics of PAHs and soils. These findings provide some basic understandings of the entrapped mechanisms of PAH NERs, helping to establish strategies for improving their detection accuracy.

Qualitative classification of waste garments for textile recycling based on machine vision and attention mechanisms.

The increasing volume of garment waste underscores the need for advanced sorting and recycling strategies. As a critical procedure in the secondary usage of waste clothes, qualitative classification of garments categorizes post-consumer clothes based on types and styles. However, this process currently relies on manual labor, which is inefficient, labor-intensive, and poses risks to workers. Despite efforts to implement automatic clothes classification systems, challenges persist due to visual complexities such as similar colors, deformations, and occlusions. In response to these challenges, this study introduces an enhanced intelligent machine vision system with attention mechanisms designed to automate the laborious and skill-demanding task of garment classification. Initially, a waste garment dataset comprising approximately 27,000 garments was curated using a self-developed automatic classification platform. Subsequently, the proposed attention method parameters were selected, and a series of benchmarks were conducted against state-of-the-art methods. Finally, the proposed system underwent a two-week online deployment to evaluate its running stability and sensitivity to similar colors, deformation, and occlusion in industrial production settings. The benchmarks indicate that the proposed method significantly improves classification accuracy across various models. The visualization interpretation of Grad-CAM reveals that the proposed method effectively handles complex environments by directing its focus toward garment-related pixels. Notably, the proposed system elevates classification accuracy from 68.28 % to human-level performance (>90 %) while ensuring greater running stability. This advancement holds promise for automating the classification process and potentially alleviating workers from labor-intensive and hazardous tasks associated with clothes recycling.

Effect of magnetic field pretreatment on germination characteristics, phenolic biosynthesis, and antioxidant capacity of quinoa.

The development of quinoa-based functional foods with cost-effective methods has gained considerable attention. In this study, the effects of magnetic field pretreatment on the germination characteristics, phenolic synthesis, and antioxidant system of quinoa (Chenopodium quinoa Willd.) were investigated. The results showed that the parameters of magnetic field pretreatment had different effects on the germination properties of five quinoa varieties, in which Sanjiang-1 (SJ-1) was more sensitive to magnetic field pretreatment. The content of total phenolics and phenolic acids in 24-h germinated seeds increased by 20.48% and 26.54%, respectively, under the pretreatment of 10 mT magnetic fields for 10 min compared with the control. This was closely related to the activation of the phenylpropanoid pathway by increasing enzyme activities and gene expression. In addition, magnetic field improved 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free radicals scavenging capacities and increased peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione peroxidase (GSH-Px) activities. This study suggests that magnetic field pretreatment enhanced gene expression of phenylalanine ammonia lyase (PAL), 4-coumarate-CoA ligase (4CL), chalcone synthase (CHS) and chalcone isomerase (CHI), increased antioxidant enzyme activity and phenolics content. Thereby lead to an increase in the antioxidative capacity of quinoa.

Accurate prediction bioaccessibility of PAHs in soil-earthworm system by novel magnetic solid phase extraction technique.

Conventional chemical extraction methods may lead to overestimate or underestimate bioaccessibility due to their inability to provide realistic kinetic information regarding PAHs in soils. In this study, we propose the use of magnetic solid phase extraction (MSPE) technique for assessing the bioaccessibility of PAHs in the soil-earthworm system. Firstly, a novel polydopamine-coated magnetic core-shell microspheres (Fe3O4-C16@PDA) was developed by a one-pot sol-gel and self-polymerization method. The PDA coatings not only enhance the hydrophilicity of material surfaces but also exhibit excellent biocompatibility. The maximum adsorption capacity of Fe3O4-C16@PDA for 16 PAHs was 52.72 mg g-1, indicating that the proposed material fulfills the assessment requirements for highly contaminated soil. To compare the measurement of PAHs and their uptake by earthworms (Eisenia fetida), experiments were conducted using four different soils with varying properties. The desorption kinetics data obtained from these experiments demonstrated that the capability of the MSPE in accurately predicting the bioavailable portions of PAHs. After a 28-day exposure, the best predictor of bioavailable PAHs in earthworms was MSPE method exhibited the highest correlation coefficient (R2 > 0.90), and its slopes in the four soils were 0.972, 0.961, 1.012, and 0.962, respectively, all close to 1. These results demonstrate that the MSPE method successfully mimics the conditions encountered in soil-earthworm systems and effectively assess bioaccessibility of PAHs in soils.

Response inhibition impairment related to altered frontal-striatal functional connectivity in insomnia disorder: A pilot and non-clinical study.

BACKGROUND: It is not clear whether and how insomnia disorder (ID) impairs response inhibition ability. Fronto-striatal functional connectivity (FC) plays a critical role in response inhibition and is found be abnormal in patients with ID. In this study, we examined whether insomnia symptoms impair response inhibition in a large non-clinical sample and whether impaired response inhibition is related to abnormal fronto-striatal FC. METHODS: One hundred and fifteen young ID patients and 160 age and sex-matched healthy controls (HC) underwent resting-state functional magnetic response imaging scans and performed the stop-signal task (SST). Performance of SST, Gray Matter Volumes (GMVs), and connections of brain regions related to fronto-striatal circuits was compared between groups. Further examined the association between response inhibition impairment and fronto-striatal FC. RESULTS: The behavioral results showed that patients with ID had significantly longer stop-signal reaction time (SSRT) compared with the HC, reflecting the impaired response inhibition among IDs. Brain imaging results showed IDs had decreased GMVs of the Right Superior Frontal (SFG) and left Supplementary Motor area (SMA). Seed-based FC results showed that compared to HC, the ID showed decreased FC between left SMA and left Paracentral lobule, left SMA and right SMA, and right SFG and right Orbital Middle Frontal gyrus, and increased FC between right SFG and right putamen. Meanwhile, the FC between right SFG and putamen was positively correlated with SSRT in IDs. CONCLUSIONS: The current study found significantly impaired response inhibition among ID and this impairment may be related to abnormal fronto-striatal FC in ID.

Real-time observation of stationary and pulsating noise-like vector pulses in a fiber laser.

Rapid progress in real-time measurement technology has uncovered varieties of transient pulse dynamics. Here, we report the vector nature of noise-like pulse (NLP) in a passive fiber laser based on the nonlinear optical loop mirror (NOLM) as the polarization independent saturable absorber. After achieving the basic operation regime of NLP, various types of vector pulses, namely, the polarization locked noise-like vector pulse (PLNLVP), the group velocity locked noise-like vector pulse (GVLNLVP), and the transitional state of combined characteristics of GVLNLVP and polarization rotation noise-like vector pulse (PRNLVP) are also obtained in the cavity. Besides, by utilizing the Dispersive Fourier transform (DFT) technique, the spectral evolution and the energy vibration of pulsating PLNLVP, GVLNLVP, and the transitional state of combined characteristics of GVLNLVP and PRNLVP are also analyzed in real time. Particularly, the coexisting pulsation vector state of NLP and soliton is also captured. All these findings will help to complement our understanding of noise-like vector pulses (NLVPs) in a fiber laser.

Overcoming slow removal efficiency-induced highly toxic I-DBPs in water by oxygen vacancies enriched invasive plant biochar catalyst: Experimental and theoretical studies.

Developing effective and safe catalysts operated in the in-depth removal of iodinated X-ray contrast media is important for overcoming slow removal efficiency-induced highly toxic iodine-replaced disinfection byproducts (I-DBPs). In this study, a novel oxygen vacancies enriched heterogeneous biochar catalyst (Mo-Co-ECM) from the invasive plant was synthesized by a facile one-step hydrothermal carbonization method and used for the in-depth removal of iohexol (IOH) by the activation of peroxymonosulfate (PMS). The results indicated that after adding PMS for 3 min, the removal efficiency of IOH in Mo-Co-ECM/PMS system reached 100% and exhibited a superior degradation efficiency compared to Co-ECM/PMS and ECM/PMS system. Only nine I-DBPs were found during the degradation, which were dominated by small molecules compounds (MW<400). The in-depth degradation suppresses the formation of the toxic intermediates. The density functional theory and electron spin resonance showed that due to the existence of Mo and oxygen vacancies, the electron transfer ability was improved, which accelerated the cycle of Co3+/Co2+, so as to enhance the catalytic activity of Mo-Co-ECM/PMS system. This study is expected to provide a general way for decreasing the production of toxic intermediates during the advanced oxidation of contaminants, meanwhile recovering resources.

Synthesis of Imidazole-Based Molecules under Ultrasonic Irradiation Approaches.

Imidazole-based compounds are a series of heterocyclic compounds that exhibit a wide range of biological and pharmaceutical activities. However, those extant syntheses using conventional protocols can be time-costly, require harsh conditions, and result in low yields. As a novel and green technique, sonochemistry has emerged as a promising method for organic synthesis with several advantages over conventional methods, including enhancing reaction rates, improving yields, and reducing the use of hazardous solvents. Contemporarily, a growing body of ultrasound-assisted reactions have been applied in the preparation of imidazole derivatives, which demonstrated greater benefits and provided a new strategy. Herein, we introduce the brief history of sonochemistry and focus on the discussion of the multifarious approaches for the synthesis of imidazole-based compounds under ultrasonic irradiation and its advantages in comparison with conventional protocols, including typical name-reactions and various sorts of catalysts in those reactions.

Subtypes of insomnia revealed by the heterogeneity of neuroanatomical patterns: A structural MRI study.

The current conflicting neuroimaging findings of insomnia disorder (ID) may be attributed to heterogeneity in ID. The present study aims to clarify the high heterogeneity in ID and examine the objective neurobiological subtypes of ID by using a novel machine learning method based on gray matter volumes (GMVs). We recruited 56 patients with ID and 73 healthy controls (HCs). The T1-weighted anatomical images were obtained for each participant. We investigated whether the ID has higher interindividual heterogeneity in GMVs. Then, we used a heterogeneous machine learning algorithm by discriminative analysis (HYDRA) to identify subtypes of ID with features of brain regional GMVs. We found that patients with ID have higher interindividual variability than HCs. HYDRA identified two distinct and reliable neuroanatomical subtypes of ID. Two subtypes showed significantly different aberrance in GMVs compared with HCs. Specifically, subtype 1 exhibited widespread decreased GMVs in some brain regions, including the right inferior temporal gyrus, left superior temporal gyrus, left precuneus, right middle cingulate, and right supplementary motor area. Subtype 2 only demonstrated increased GMVs in the right superior temporal gyrus. Additionally, the GMVs of altered brain regions in subtype 1 were significantly correlated with daytime functioning, but in subtype 2, they were significantly correlated with sleep disturbance. These results explain conflicting neuroimaging findings and propose a potential objective neurobiological classification contributing to ID's precise clinical diagnosis and treatment.

Amentoflavone impairs the reconsolidated fear memories through inhibition of ERK pathway.

Post-traumatic stress disorder (PTSD) is a pathological fear memory-related disease. The persistence of pathological fearful memories is one of the most characteristic symptoms of PTSD. However, this can be eliminated by intervening in reconsolidation. Inflammation is intimately involved in the pathophysiologic progression of PTSD. Amentoflavone (AF) has anti-inflammatory effects. However, the effect of AF on fear memory reconsolidation remains unclear. In the present series of experiments, the CFC paradigm of rats were constructed. This was followed by AF administration immediately after exposure to the conditioning chamber to observe the maintenance of fear memory. Finally, a Western blot for the amygdala was used to explore the possible molecular biological mechanisms of AF affecting animal behavior. The findings suggest that re-exposure to the conditioning chamber for retrieval of CFC memory followed by immediate intragastric AF administration in rats attenuated the fear response for at least 14 days. In addition, the Western blot results show that the CFC memory intervention effect of AF administration during the reconsolidation phase may be related to the ERK signaling pathway inhibition. In general, the administration of AF in the reconsolidation phase to inhibit neuroinflammation can block the reconsolidation process and disrupt fear memory retention in the long term, at least in part through ERK pathway.

Establishment of DAS-ELISA for the detection of antigenic changes in glycinin after heat processing.

In this study, a double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) method was established to detect the antigenic changes of thermally processed products containing glycinin. The proposed DAS-ELISA method used heat-treated antigen-absorbing antiserum as the coating antibody, and horseradish peroxidase (HRP)-labeled rabbit anti-glycinin polyclonal antibody as the detection antibody. The specificity test results which were obtained using the proposed method indicated that good specificity had been achieved. The cut-off value was 0.388, and the LOD was determined to be 19.53 ng/mL. The coefficient of variation was less than 5.25% (intra-day) and 9.50% (inter-day). In this study's milk powder addition test, the recovery rate of the glycinin ranged between 83.65% and 90.13%. The established DAS-ELISA method was also used to detect soybean thermal processing products, such as soy sauce, steamed fish and soy sauce, soybean paste, beef sauce, soy milk powder, and tofu. The results showed that the OD450 values of the aforementioned products were lower than the OD450 values of the glycinin in defatted soybean flour. Therefore, it was indicated that the above products has undergone different degrees of thermal processing. In other words, the majority of the epitopes of glycinin in the products had been destroyed by the thermal processing and could not be combined with heat-treated antigen-absorbing antiserum.

Effect of curcumin on the non-alcoholic steatohepatitis via inhibiting the M1 polarization of macrophages.

BACKGROUND: Non-alcoholic steatohepatitis (NASH) is a global medical problem and macrophages' activation is closely related to the pathogenesis of NASH. Curcumin is a polyphenol from turmeric with significant anti-inflammatory activity. OBJECTIVE: The objective of present study was to observe the effect of curcumin on macrophages' activation and secretion of pro-inflammatory cytokines in NASH. METHODS: Hematoxylin and eosin and TUNEL staining were used to observe the hepatic function. RT-PCR was conducted to evaluate the hepatic mRNA expression of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß). Flow cytometry was adopted to detect the M1 polarization of macrophages. The RAW264.7 macrophage was pretreated with different doses of curcumin, and then lipopolysaccharide (LPS) and interferon-γ (IFN-γ) were given to activate the M1 macrophage. The activation ratio of M1 macrophage was observed by flow cytometry, and IL-1ß and TNF-α expression was detected by RT-PCR and ELISA. RESULTS: After treatment with curcumin, the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the mRNA expression of TNF-α and IL-1ß, and M1 polarization of macrophages were significantly decreased. Hematoxylin and eosin and TUNEL staining showed that inflammation and apoptosis in the liver were improved. What is more, curcumin can effectively inhibit M1 macrophage activation induced by lipopolysaccharide and IFN-γ and reduce the secretion of IL-1ß and TNF-α. CONCLUSION: Curcumin can effectively improve NASH and reduce hepatic cell necrosis by inhibiting the M1 polarization of macrophages and the secretion of inflammatory factors.

Magnetic solid-phase extraction as a novel method for the prediction of the bioaccessibility of polycyclic aromatic hydrocarbons.

Chemical methods used to predict the bioaccessibility of hydrophobic organic compounds (HOCs) still need further development and improvement. In this work, magnetic solid-phase extraction (MSPE) based on poly(ß-cyclodextrin)-coated magnetic polydopamine (Fe3O4@PDA@PCD) was first introduced to assess the bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) in soils. Due to its good hydrophilicity and submicrometer scale, Fe3O4@PDA@PCD displayed a higher extraction rate for PAHs in an aqueous solution (equilibrium time < 5 min) than Tenax resin, which had an equilibrium time longer than 30 min. The merits of Fe3O4@PDA@PCD are beneficial to accelerate the desorption of PAHs from soil, especially for high molecular weight PAHs, in which the amounts extracted by Fe3O4@PDA@PCD were 1.2-2.8 times higher than those extracted by Tenax resin. The desorption kinetics data were well fitted with a two- or three-fraction model. The fitting results indicated that the MSPE method can be used to predict the bioaccessible fractions of PAHs. By comparing the prediction results obtained from the MSPE method with bioassays using earthworms, a significant linear correlation (R2 = 0.98) with a slope statistically close to 1 was obtained. These results suggested that the MSPE method can act as a simple and efficient method to measure the bioaccessibility of PAHs in soil.

Facile synthesis of polydivinylbenzene coated magnetic polydopamine coupled with pressurized liquid extraction for the extraction and cleanup of polycyclic aromatic hydrocarbons in soils.

Due to the trace levels of polycyclic aromatic hydrocarbons (PAHs) in soil and the complexity of soil matrices, effective sample pretreatment methods are of great significance to obtain accurate analytical results. In this paper, polydopamine (PDA) encapsulated Fe3O4 particles were used as seeds for in situ polymerization of divinylbenzene (DVB) to derive magnetic hybrid material Fe3O4@PDA@PDVB. Coupled with pressurized liquid extraction, Fe3O4@PDA@PDVB was investigated as a selective adsorbent for the extraction and cleanup of PAHs in soil. The prepared magnetic material was characterized and demonstrated to possess strong hydrophobicity and superparamagnetism. Under optimal conditions, Fe3O4@PDA@PDVB can effectively extract 15 PAHs from a 30% methanol solution within 2 min, and it is more selective for PAHs than for n-alkane in soil extracts. The matrix effect significantly decreased after extraction by the prepared material, which showed superiority to a silica gel column method (EPA 3630C Method). The developed method was linear (5-1000 ng g-1) with coefficient of determination (R2) ranging from 0.9986-0.9998, and the limits of detection were 0.13-0.54 ng g-1. Additionally, repetitive experiments indicated that the prepared material was reproducible and reusable with relative standard deviations below 8.4% and 8.6%, respectively. Finally, the new method was successfully employed to determine the concentrations of PAHs in genuine soil and standard reference material, and the results were comparable to those of widely utilized EPA methodology.

Polydopamine-coated polyethylene sieve plate as an efficient and convenient adsorption sink for the bioaccessibility prediction of PAHs in soils.

Bioaccessibility measurements of polycyclic aromatic hydrocarbons (PAHs) in soils are significant for exposure risk assessment. The current physicochemical methods require tedious operation processes, underestimate the actual risks, or are unsuitable for high organic content soils. In this work, an efficient and convenient method based on polydopamine-coated polyethylene sieve plate (PDA@PESP) and hydroxypropyl-ß-cyclodextrin (HPCD) was developed to predict the bioaccessibility of PAHs in multi-type soils. The PDA@PESP can be prepared via in situ self-polymerization, allowing to extract PAHs from HPCD solution quantitatively and rapidly. When applied to evaluate the bioaccessibility with PDA@PESP as an adsorption sink and HPCD as a diffusive carrier, the proposed method can significantly improve the extractable fraction of PAHs compared to single HPCD extraction in particular for high organic carbon content soil and high-ring PAHs. The desorption kinetics data indicated that the method can predict the bioaccessible fraction of PAHs. In addition, the method predicted a satisfactory accumulation into earthworms (Eisenia fetida) with a slope statistically approximated to 1. A highly significant linear regression (R2 = 0.95) was also found between the proposed method and Tenax desorption in historically contaminated soils, demonstrating that the method is an efficient and convenient approach for the bioaccessibility prediction of PAHs in soils.

Study on four metal organic frameworks as cleanup adsorbents for polycyclic aromatic hydrocarbons determined by GC-MS/MS.

A new application of MOFs as adsorbents in the cleanup procedure of polycyclic aromatic hydrocarbons (PAHs) in soils was explored. Four MOFs, specifically MIL-101(Cr), MIL-125(Ti), MIL-100(Fe) and UiO-66(Zr), were synthesized and characterized. A screening study was carried out to select the best adsorbent for the purification of sixteen PAHs in complex soil extract. It is found that the nature of metal ion, pore size, surface area and surface charge affect the purification efficiencies of the various MOFs. MIL-101(Cr) was then selected because of its best purification efficiency. The effects of amount of adsorbent, cleanup solvent and cleanup time on cleanup efficiency were investigated. Under the optimum conditions, the matrix effect of the target analytes was reduced by more than 65%. The method was then combined with ultrasonic extraction and quantitation by gas chromatography with triple quadrupole mass spectrometric detection. The method allows for the determination of PAHs in soils with linear in the range of 5-5000 ng g-1 and with LODs between 50 and 420 pg g-1. The method was applied to the analysis of (spiked) soil samples, and results compared well with the established EPA method. Graphical abstract Schematic presentation of metal organic frameworks (MOF) as cleanup adsorbents for purifying polycyclic aromatic hydrocarbons in soil organic matter (SOM) and further determined by gas chromatography with triple quadrupole mass spectrometry detection (GC-MS/MS).

Preparation of phenyl-modified magnetic silica as a selective magnetic solid-phase extraction adsorbent for polycyclic aromatic hydrocarbons in soils.

Accurate analysis of polycyclic aromatic hydrocarbons (PAHs) in soils remains a challenge due to the complexity of sample matrices. In this paper, phenyl-modified magnetic mesoporous silica (Fe3O4@mSiO2-Ph-PTSA) was synthesized with p-toluenesulfonic acid (PTSA) as the catalyst and used as a selective adsorbent for the clean-up of PAHs extracted from soils. The material prepared without PTSA as the catalyst (Fe3O4@mSiO2-Ph) was synthesized for comparison. The synthesized materials were first systematically characterized and evaluated. It was found that the grafting amount of the phenyl group onto Fe3O4@mSiO2-Ph-PTSA was higher than that onto Fe3O4@mSiO2-Ph. The extraction efficiency obtained by extracting PAHs from the extracted soil matrix solution demonstrated that Fe3O4@mSiO2-Ph-PTSA possessed a much higher extraction efficiency than that of Fe3O4@mSiO2-Ph, which can be attributed to the greater amount of phenyl groups grafted on Fe3O4@mSiO2 in the presence of the PTSA catalyst. Moreover, contrast experiments showed that Fe3O4@mSiO2-Ph-PTSA displayed higher selectivity towards PAHs than towards n-alkanes and that the π-π interaction played a key role in the adsorption process. In the presence of the soil extract matrix, the parameters affecting the extraction efficiency of Fe3O4@mSiO2-Ph-PTSA for PAHs were optimized. Under the optimal conditions, coupled with pressurized liquid extraction and gas chromatograph-mass spectrometer, the proposed method for the determination of PAHs in soils was linear in the range of 5-500 ng g-1, and the correlation coefficients (R) ranged between 0.9994 and 0.9999. The limits of detection (LODs) and limits of quantification (LOQs), which were based on signal-to-noise ratios of 3 and 10, respectively, were in the range of 0.07-0.41 ng g-1 and 0.24-1.37 ng g-1. The developed method displayed a better clean-up effect than that for silica gel column method, and the matrix effect markedly decreased compared to that of the uncleaned condition. Finally, the developed method was successfully applied for the detection of PAHs in environmental soils, and the data were consistent with the results obtained by the silica gel column method. The analytical results were also consistent with those for the real environment.

Rapid preparation of methyltrimethoxy-modified magnetic mesoporous silica as an effective solid-phase extraction adsorbent.

A time-saving method was applied to synthesize methyltrimethoxy-modified magnetic mesoporous silica with or without p-toluenesulfonic acid as the catalyst for magnetic solid-phase extraction. The synthesized materials were systematically characterized. Results demonstrated that methyltrimethoxy modified magnetic mesoporous silica with p-toluenesulfonic acid as the catalyst has a relatively smaller aperture and extreme hydrophobicity (water contact angle of 135°). To evaluate the feasibility of these prepared materials as effective adsorbents, it was combined with gas chromatography and electron capture detection to determine 26 polychlorinated biphenyls in environmental water. The result revealed that methyltrimethoxy modified magnetic mesoporous silica with p-toluenesulfonic acid as the catalyst had the best extraction efficiency and recovery. Under the optimized extracted conditions, the proposed method showed good linearity within the concentration range of 5 to 200 ng/L with correlation coefficients of 0.9969 to 0.9999. The limits of detection and quantification based on signal-to-noise ratios of 3 and 10 were in the range of 0.16 to 0.91 and 0.52 to 3.0 ng/L, respectively. The polychlorinated biphenyl concentrations in environmental water samples were successfully determined using the developed method. PCB008 and PCB110 were 4.05 and 8.52 ng/L in Red-Star lake water (Hubei Province, China), respectively.

Enhanced adsorption removal of anionic dyes via a facile preparation of amino-functionalized magnetic silica.

A novel amino-functionalized magnetic silica (Fe3O4@SiO2-NH2) was easily prepared via a one-step method integrating the immobilization of 3-aminopropyltriethoxysilane with a sol-gel process of tetraethyl orthosilicate into a single process. This showed significant improvement in the adsorption capacity of anionic dyes. The product (Fe3O4@SiO2-NH2) was characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectrometry, zeta potential and vibrating sample magnetometry. The adsorption performance of Fe3O4@SiO2-NH2 was then tested by removing acid orange 10 (AO10) and reactive black 5 (RB5) from the aqueous solutions under various experimental conditions including initial solution pH, initial dye concentrations, reaction time and temperature. The results indicated that the maximum adsorption capacity of AO10 and RB5 on Fe3O4@SiO2-NH2 was 621.9 and 919.1 mg g-1 at pH 2, respectively. The sorption isotherms fit the Langmuir model nicely. Similarly, the sorption kinetic data were better fitted into the pseudo-second order kinetic model than the pseudo-first order model. In addition, the thermodynamic data demonstrated that the adsorption process was endothermic, spontaneous and physical. Furthermore, Fe3O4@SiO2-NH2 could be easily separated from aqueous solutions by an external magnetic field, and the preparation was reproducible.