Size-classifiable quantification of nanoplastic by rate zonal centrifugation coupled with pyrolysis-gas chromatography-mass spectrometry.

Particle size is an important indicator to evaluate the environmental risk and biotoxicity of nanoplastic (NP, particle diameter <1000 nm). The methods available to determine size classes of NP in environmental samples are few and are rare to achieve efficient separation and recycling of NP with close particle sizes. Here, we show that rate-zonal centrifugation (RZC) can quickly and efficiently collect NP of different sizes based on their sedimentation coefficients. When combined with cloud-point extraction (CPE) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), our method can quantify three NP particle-size classes separately (including 100 nm, 300 nm, and 600 nm) in aqueous samples with high recovery (81.4 %-89.4 %), limits of detections (LODs, 33.5-53.4 µg/L), and limits of quantifications (LOQs, 110.6-167.2 µg/L). Compared with the conventional sample pretreatment process, our method can effectively extract and determine the NP with different sizes. Our approach is highly scalable and can be effectively applied to NP in a wide range of aquatic environments. Meanwhile, our approach is highly scalable to incorporate diverse assays to study the environmental behaviours and ecological risks of NP.

Soil erosion is a major drive for nano & micro-plastics to enter riverine systems from cultivated land.

Nano and micro-plastics (NMPs, particles diameter <5 mm), as emerging contaminants, have become a major concern in the aquatic environment because of their adverse consequences to aquatic life and potentially human health. Implementing mitigation strategies requires quantifying NMPs mass emissions and understanding their sources and transport pathways from land to riverine systems. Herein, to access NMPs mass input from agricultural soil to riverine system via water-driven soil erosion, we have collected soil samples from 120 cultivated land in nine drainage basins across China in 2021 and quantified the residues of six common types of plastic, including polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polypropylene (PP), polyethylene (PE), polycarbonate (PC), and polystyrene (PS). NMPs (Σ6plastics) were detected in all samples at concentrations between 3.6 and 816.6 µg/g dry weight (median, 63.3 µg/g) by thermal desorption/pyrolysis-gas chromatography-mass spectrometry. Then, based on the Revised Universal Soil Loss Equation model, we estimated that about 22,700 tonnes of NMPs may enter the Chinese riverine system in 2020 due to agricultural water-driven soil erosion, which occurs primarily from May to September. Our result suggested that over 90% of the riverine NMPs related to agricultural soil erosion in China are attributed to 36.5% of the country's total cultivated land, mainly distributed in the Yangtze River Basin, Southwest Basin, and Pearl River Basin. The migration of NMPs due to water-driven soil erosion cannot be ignored, and erosion management strategies may contribute to alleviating plastic pollution issues in aquatic systems.

A novel compound heterozygous variant of ECEL1 induced joint dysfunction and cartilage degradation: a case report and literature review.

Background: Distal arthrogryposis type 5D (DA5D) represents a subtype of distal arthrogryposis (DA) characterized by congenital joint contractures in the distal extremities. DA5D is inherited in a rare autosomal recessive manner and is associated with the ECEL1 gene. In this report, we describe a case of an infant with bilateral knee contractures and ptosis, caused by a novel compound heterozygous mutation of ECEL1. Case presentation: We conducted DNA extraction, whole-exome sequencing analysis, and mutation analysis of ECEL1 to obtain genetic data on the patient. We subsequently analyzed the patient's clinical and genetic data. The proband was a 6 months-old male infant who presented with significant bilateral knee contracture disorders and bilateral ptosis. MRI demonstrated cartilage degradation in knee joint. Whole-exome sequencing of the patient's DNA revealed a compound heterozygous mutation of c.2152-15C>A and c.110_155del in ECEL1. Analysis with the MutationTaster application indicated that c.110_155del was pathogenic (probability = 1), causing frameshift mutations affecting 151 amino acids (p.F37Cfs*151). The truncated protein lost the substructure of a transmembranous site based on the predicted protein crystal structure AF-O95672-F1. The variant of c.2152-15C>A of ECEL1 was also predicted to be disease-causing (probability = 0.98) as it impaired the methylation of ECEL1 serving as an H3K27me3 modification site, which led to the dysfunction of the second topological domain. Therefore, we concluded that the compound heterozygous mutation caused the pathogenic phenotype of this proband. Conclusion: The present case highlights the usefulness of molecular genetic screening in diagnosing unexpected joint disorder. Identification of novel mutations in the ECEL1 gene broadens the mutation spectrum of this gene and adds to the genotype-phenotype map of DA5D. Furthermore, rapid whole-exome sequencing analysis enabled timely diagnosis of this rare disease, facilitating appropriate treatment and scheduled follow-up to improve clinical outcomes.

Quantification and Characterization of Fine Plastic Particles as Considerable Components in Atmospheric Fine Particles.

The negative effects of air pollution, especially fine particulate matter (PM2.5, particles with an aerodynamic diameter of ≤2.5 µm), on human health, climate, and ecosystems are causing significant concern. Nevertheless, little is known about the contributions of emerging pollutants such as plastic particles to PM2.5 due to the lack of continuous measurements and characterization methods for atmospheric plastic particles. Here, we investigated the levels of fine plastic particles (FPPs) in PM2.5 collected in urban Shanghai at a 2 h resolution by using a novel versatile aerosol concentration enrichment system that concentrates ambient aerosols up to 10-fold. The FPPs were analyzed offline using the combination of spectroscopic and microscopic techniques that distinguished FPPs from other carbon-containing particles. The average FPP concentrations of 5.6 µg/m3 were observed, and the ratio of FPPs to PM2.5 was 13.2% in this study. The FPP sources were closely related to anthropogenic activities, which pose a potential threat to ecosystems and human health. Given the dramatic increase in plastic production over the past 70 years, this study calls for better quantification and control of FPP pollution in the atmosphere.

Glycine Enhances Oxidative Stress Tolerance and Biocontrol Efficacy of Sporidiobolus pararoseus against Aspergillus niger Decay of Apples.

Apples are deeply loved by people because of their rich nutritional value, but they are susceptible to rotting. The use of antagonistic yeast is a promising method for controlling postharvest fruit diseases, but biocontrol efficacy of yeast will be weakened in environmental stress. In this study, the effects of glycine (Gly) on the oxidative stress tolerance and the biocontrol efficacy of Sporidiobolus pararoseus (S. pararoseus) against Aspergillus niger (A. niger) are discussed. Under the stimulation of H2O2, the yeast cells treated with Gly (1 mM) showed lower ROS content, less mitochondrial impairment and cellular oxidative damage, and the cell survival rate was significantly higher than Gly-untreated yeast. The yeast cells exposed to Gly significantly increased the activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and the content of glutathione (GSH). Notably, Gly-treated yeast cells had better biocontrol efficacy against A. niger in postharvest apples. The lesion diameter and decay incidence were reduced by 17.67 mm and 79.63% compared to the control, respectively, when S. pararoseus was treated with 1 mM Gly. Moreover, Gly-treated yeast increased the antioxidant enzymes activities and their gene expression were up-regulated in apples. These results indicated that 1 mM Gly not only reduced the oxidative damage of yeast, but also induced resistance-related enzymes of apples under oxidative stress, which contributed to enhancing the biocontrol efficacy of S. pararoseus against A. niger in apples.

A novel homozygous variant of TMEM260 induced cardiac malformation and neurodevelopmental abnormality: case report and literature review.

Background: Congenital heart disease (CHD) represents the most widespread congenital birth defect among neonates worldwide, leading to substantial expenses and contributing significantly to premature death caused by birth defects. Despite the significance of CHD, research on its etiology remains limited and has failed to provide substantial evidence for the molecular basis of the disease. With the advancement of next-generation sequencing (NGS), genetic screening has become increasingly accessible, offering a greater capability for identifying potential genetic variants associated with CHD. Case presentation: Exome sequencing and variant analysis of TMEM260 were performed to obtain genetic data, and clinical characteristics were determined. A complex and severe form of CHD, comprising a persistent truncus arteriosus type I, ventricular septal defect, right aortic arch, as well as critical neurodevelopmental delay and neurological dysfunction, was observed in a patient. This proband presented global muscle hypotonia and a significant delay in gross and fine motor development. Cranial computed tomography scanning showed the presence of bilateral apical, occipital, and temporal subdural effusions; slightly wider bilateral lateral ventricles and annular cisterns; and bilateral cerebral hemispheric parenchyma atrophy. Upon genetic analysis of the patient, a novel homozygous mutation was identified in the TMEM260 gene. The mutation, c.1336_1339DEL, was found to be homozygous and resulted in a frameshift mutation, causing a p.L447Vfs*9 amino acid change. This mutation led to the deletion of a TCTC sequence from positions 1336 to 1339 in the TMEM260 gene, changing leucine to valine at amino acid 447 and introducing a stop codon after the ninth amino acid. This structural deletion in the TMEM260 protein resulted in the loss of gene function. Conclusion: This case report presents a newly discovered variant site in the TMEM260 gene and reinforces the relationship between TMEM260 molecular function and differentiation of mesoderm and ectoderm. Furthermore, our findings broaden the spectrum of variants in the TMEM260 gene and contribute to advancing the genetic understanding of CHD.

Case Report: A novel KNCH2 variant-induced fetal heart block and the advantages of fetal genomic sequencing in prenatal long-term dexamethasone exposure.

Background: Fetal bradycardia is a common but severe condition. In addition to autoimmune-mediated fetal heart block, several types of channelopathies induce high-degree atrioventricular block (AVB). Long QT syndrome (LQTS) is a major cause of non-autoimmune-mediated fetal heart block. Due to the limitations of prenatal diagnostic technologies, LQTS is seldom identified unless fetal genetic screening is performed. Thus, long-term prenatal dexamethasone (DEX) exposure can become a challenge for these patients. We report on a rare case of a novel KCNH2 variant related to LQTS and associated with high-degree fetal AVB with long-term DEX exposure. This case led us to review our prenatal administration strategy for such patients. Case Presentation: A fetus was identified with high-degree AVB (2:1 transduction at 28 + 2 gestational weeks). Typical tests of immune function in the pregnant woman were conducted including tests for thyroid function, rheumatic screening, autoimmune antibodies (such as anti-Ro/SSA and anti-La/SSB), and anti-nuclear antibodies (anti-ANA). Following the recommended protocol, the pregnant patient received DEX (0.75 mg/day) during pregnancy. Subsequently, the fetal AVB changed from 2:1 to prolonged AV intervals with ventricular tachycardia, which suggested a therapeutic benefit of DEX in some respects. However, a high-degree AVB with a significantly prolonged QTc interval was identified in the neonate following birth. Genetic testing revealed that a KCNH2 c.1868C>A variant induced LQTS. The body length remained approximately -3.2 SD from the reference value after prenatal long-term DEX exposure, which indicated a developmental restriction. Additionally, the functional validation experiments were performed to demonstrate the prolonged duration of calcium transit both in depolarization and repolarization with the KCNH2 c.1868C>A variant. Conclusion: Genetic screening should be recommended in fetuses with autoimmune antibody negative high-degree AVB, especially for 2:1 transduction AVB and in fetuses with changes in fetal heart rhythm following initial DEX treatment. Genetic screening may help identify genetic variant-related channelopathies and avoid unexpected prenatal exposure of DEX and its possible long-term adverse postnatal complications.

Non-Destructive Extraction and Separation of Nano- and Microplastics from Environmental Samples by Density Gradient Ultracentrifugation.

Nano-/microplastics (NMPs, particle diameter < 5 mm) are widespread emerging pollutants causing diverse impacts on organisms due to their sizes, shapes, and chemical properties. Despite the fast increase in NMP research, an effective method to separate and identify NMP types from environmental samples is still lacking. Here, we developed a simple and effective approach for the non-destructive extraction and separation of various types of NMPs from environmental samples by density gradient ultracentrifugation (DGU). For the first time, DGU was capable to separate various NMPs from the complex matrix with high selectivity (100%), purity (93%), and applicability. Through a gradually changing density of the density gradient medium by changing the concentrations or volumes of CsCl/water solution (from 0.00065 to 0.01989 g cm-3 mm-1), various NMPs (with particle sizes as little as 50 nm) could be extracted and separated from soil samples with high recovery (78.5-96.0%). We confirmed the effectiveness and compatibility of DGU through a correct identification of all types of NMPs separated from artificial soil samples with Raman spectroscopy, simultaneous thermal analysis (STA), and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). DGU is compatible with all analytical processes compared to other existing methods with much less sample pretreatment time (0.5 h). Overall, DGU is an effective and cheap method (2.2 USD/sample) to separate NMPs from environmental samples such as soil and water and, hence, can facilitate research on NMPs related to terrestrial and marine environments as well as human health.

Toxicity of zearalenone and its nutritional intervention by natural products.

Zearalenone (ZEN) is a toxic secondary metabolite mainly produced by fungi of the genus Fusarium, and is often present in various food and feed ingredients such as corn and wheat. The structure of ZEN is similar to that of natural estrogen, and it can bind to estrogen receptors and has estrogenic activity. Therefore, it can cause endocrine-disrupting effects and promote the proliferation of estrogen receptor-positive cell lines. In addition, ZEN can cause oxidative damage, endoplasmic reticulum stress, apoptosis, and other hazards, resulting in systemic toxic effects, including reproductive toxicity, hepatotoxicity, and immunotoxicity. In the past few decades, researchers have tried many ways to remove ZEN from food and feed, but it is still a challenge to eliminate it. In recent years, natural compounds have become of interest for their excellent protective effects on human health from food contaminants. Researchers have discovered that natural compounds often used as dietary supplements can effectively alleviate ZEN-induced systemic toxic effects. Most of the compounds mitigate ZEN-induced toxicity through antioxidant effects. In this article, the contamination of food and feed by ZEN and the various toxic effects and mechanisms of ZEN are reviewed, as well as the mitigation effects of natural compounds on ZEN-induced toxicity.

Acute toxicity of tire wear particles, leachates and toxicity identification evaluation of leachates to the marine copepod, Tigriopus japonicus.

Tire wear particles (TWPs) have been characterized as microplastics in recent years, and many of these TWPs will be eventually deposited in coastal areas, leading to adverse effects to marine organisms. Results of the acute toxicity test in this study showed that the 96-h LC50 values of the particles and leachate were 771.4 mg/L (95% CI = 684.4-869.6 mg/L) and 5.34 g/L (95% CI = 4.75-6.07 g/L), respectively. The chemical constituents of TWP and the leachate are very complex, and little research has been conducted to determine which of these constituents contribute to the toxicity of TWP leachate to marine organisms. Therefore, the composition of the TWP and leachate was analyzed, and a variety of chemicals were identified, including metals (Mn, Zn, etc.) and organic compounds (cyclohexanthiol, 4-ethyl-1,2-dimethylbenzene, benzothiazole, stearic acid, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, etc.). In addition, the marine copepod Tigriopus japonicus was applied as a model species in the toxicity identification evaluation study to characterize, identify and confirm the toxicity-causing substances in the TWP leachate. Zn was identified and confirmed as the main toxicant contributing to the toxicity. Furthermore, Zn concentrations in the leachate over time were investigated. The release of Zn from TWPs to the aquatic environment was slow, and conformed to a parabolic model with a release constant k of 2.06. The organic component, benzothiazole, exhibited an antagonistic effect with zinc in the acute toxicity of the TWP leachate.

20(S)-Ginsenoside Rg3 Inhibits Lung Cancer Cell Proliferation by Targeting EGFR-Mediated Ras/Raf/MEK/ERK Pathway.

Lung cancer is the leading cause of cancer death in the world and classified into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). As tyrosine kinase inhibitors (TKIs), several triterpenoid saponins can target to epidermal growth factor receptor (EGFR), a widely used molecular therapeutic target, to exhibit remarkable anti-proliferative activities in cancer cells. As one of triterpenoid saponins, 20([Formula: see text])-ginsenoside Rg3 [20([Formula: see text])-Rg3] was confirmed to be an EGFR-TKI in this work. According to the quantitative real-time reverse transcription-PCR (qRT-PCR) and immunoblotting analysis, 20([Formula: see text])-Rg3 was certified to play a key role on EGFR/Ras/Raf/MEK/ERK signal pathway regulation. Our data demonstrated that 20([Formula: see text])-Rg3 might block the cell cycle at the G0/G1 phase by downregulating CDK2, Cyclin A2, and Cyclin E1. Molecular docking suggested that the combination of both hydrophobic and hydrogen-bonding interactions may help stabilizing the 20([Formula: see text])-Rg3-EGFR binding. Furthermore, their binding stability was assessed by molecular dynamics simulation. Taken together, these data provide the evidence that 20([Formula: see text])-Rg3 could prohibit A549 cell proliferation, probably by arresting the cell cycle at the G0/G1 phase via the EGFR/Ras/Raf/MEK/ERK pathway.

Synergistic multiple active species driven fast estrone oxidation by δ-MnO2 in the existence of methanol.

Endocrine-disrupting chemicals (EDCs) cause serious threats to human health. Five types of MnO2 were synthesized and characterized. They exhibited different removal performances for three EDCs, i.e., estrone (E1), ethynylestradiol (EE2) and bisphenol A (BPA). Only δ-MnO2 can completely remove E1 within 120 min at pH 3.0. Free Mn (III) was determined at the beginning of the reaction and participated in the EDCs removal process. Electron spin resonance (ESR) indicated that δ-MnO2 could produce superoxide anions (·O2-) and singlet oxygen (1O2) in the existence of methanol. The reactive oxygen species (ROS) quenching experiments showed 1O2 have certain contribution to the E1 removal by δ-MnO2. The source of ROS is mainly the lattice oxygen from δ-MnO2, and can be replenished through the layer structure destruction caused by the reaction between Mn(III) and E1. The ROS dependent EDCs removal by δ-MnO2 leads to a deep understanding on this well-known oxidant.

Cucurbitacin IIb induces apoptosis and cell cycle arrest through regulating EGFR/MAPK pathway.

Epidermal growth factor receptor (EGFR) is considered as a valid target in the clinical trials of anticancer therapy and tyrosine kinase inhibitors (TKIs) of EGFR are approved for cancer treatments. In present work, cucurbitacin IIb (CuIIb) was confirmed to exhibit the proliferation inhibitory activity in A549 cells. CuIIb induced apoptosis via STAT3 pathway, which was mitochondria-mediated and caspase-dependent. CuIIb also suppressed the cell cycle and induced G2/M phase cell cycle arrest. CuIIb was capable of suppressing the signal transmitting of the EGFR/mitogen-activated protein kinase (MAPK) pathway which was responsible for the apoptosis and cell cycle arrest. Homogeneous time-resolved fluorescence (HTRF) analysis demonstrated that the kinase activity of EGFR was inhibited by CuIIb. Molecular docking suggested that the CuIIb-EGFR binding fundamentally depends on the contribution of both hydrophobic and hydrogen-bonding interactions. Hence CuIIb may serve as a potential EGFR TKI.

In vitro antitumor effect of cucurbitacin E on human lung cancer cell line and its molecular mechanism.

Cucurbitacin E (CuE) is previously reported to exhibit antitumor effect by several means. In this study, CuE acted as a tyrosine kinase inhibitor interfering with the epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK) signaling pathway and subsequently induced apoptosis and cell cycle arrest in non-small-cell lung cancer (NSCLC) cell line A549. The apoptosis regulators, cleaved Caspases-3 and Caspases-9, were observed to be increased with the treatment of CuE. The activated transcription factor STAT3 and the apoptosis inhibitor protein survivin were also observed to be reduced. The cell cycle regulators, CyclinA2, cylinB1, CyclinD1 and CyclinE, were also investigated and the results suggested that the cell cycle was arrested at G1/G0 phase. Treatment of CuE also altered the existence status of most of the participants in the EGFR/MAPK signaling. Phosphorylation of EGFR enhanced significantly, leading to the alteration of members downstream, either total amount or phosphorylation level, notably, MEK1/2 and ERK1/2. Moreover, the results of molecular simulation brought an insight on the interaction mechanism between CuE and EGFR. In summary, CuE exhibited anti-proliferative effect against A549 cells by targeting the EGFR/MAPK signaling pathway.

20(S)-Protopanaxadiol blocks cell cycle progression by targeting epidermal growth factor receptor.

20(S)-Protopanaxadiol [20(S)-PPD], one of the metabolites of ginsenosides, was investigated to determine its potential mechanism for targeting to epidermal growth factor receptor (EGFR) pathway in lung cancer cell A549. Results of kinase inhibitory assay showed that 20(S)-PPD was an EGFR tyrosine kinase inhibitor. By binding to EGFR, 20(S)-PPD disrupted the EGFR/MAPK signaling. The expression of genes in the pathway was altered and the upregulation of Ras and MEK1 was extremely notable. The accumulation and phosphorylation of EGFR, Ras, BRAF, Raf-1, MEK, and ERK were variously altered. The above alteration subsequently resulted in cell cycle arrest. 20(S)-PPD interfered the cell cycle regulation network and eventually blocked cell cycle progression at G0/G1 phase, which may be the key reason for proliferation inhibition. Although some apoptosis related genes and proteins were influenced, apoptosis was not the main reason for proliferation inhibition. The cell wound healing assay confirmed that the inhibition of 20(S)-PPD to A549 cells could suppress the migration and invasion thereof. The results of molecular docking and molecular dynamics simulation provide a possible interaction mechanism between EGFR and 20(S)-PPD. The results described above suggested that 20(S)-PPD could block cell cycle progression by targeting the EGFR/MAPK signaling pathway.

Cucurbitacin IIa interferes with EGFR-MAPK signaling pathway leads to proliferation inhibition in A549 cells.

Cucurbitacin IIa (CuIIa), a tetracyclic triterpenoid harboring anticancer activity, was investigated in A549 cells to reveal its mechanism of targeting on epidermal growth factor receptor (EGFR) signaling pathway. Results showed that CuIIa was capable of inducing apoptosis and cell cycle arrest at G2/M phase. The transcription of EGFR pathway genes and their proteins accumulation was inconsistently influenced by CuIIa. Notably, transcription of Raf1 was significantly upregulated, nevertheless, MEK1 and ERK1 were significantly downregulated. On the other hand, the accumulation of the total and phosphorylated proteins of the most members in EGFR-mitogen-activated protein kinase (MAPK) pathway, as well as CylclinB1 and survivin were also shifted by CuIIa treatment. Remarkably, total MEK remained constant but survivin completely degraded. Moreover, phosphorylated BRAF continuously increased while Raf1 and MEK decreased continuously. CuIIa was further confirmed to be a tyrosine kinase inhibitor (TKI) of EGFR by kinase inhibition assay. The results of molecular simulation showed that the long side chain of CuIIa occupied the binding pocket of EGFR and the ligand was stabilized at the active site of EGFR. In view of the results above, it is suggested that CuIIa inhibits cell proliferation by interfering the EGFR-MAPK signaling pathway.

Identification of 20(R, S)-protopanaxadiol and 20(R, S)-protopanaxatriol for potential selective modulation of glucocorticoid receptor.

Although glucocorticoids (GCs) are widely used as anti-inflammatory drugs, they are often accompanied by adverse effects, which are mainly due to the transactivation of glucocorticoid receptor (GR) target genes. In order to screen novel plant-derived GR ligands (phytocorticoids) capable of separating transrepression from transactivation, this work focuses on the estimation of 20(R, S)-protopanaxadiol [PPD(R, S)] and 20(R, S)-protopanaxatriol [PPT(R, S)] for their dissociated characteristics. The reporter gene assay shows that ginsenosides cannot enhance glucocorticoid-responsive element-driven genes. The cytotoxicity assay shows that PPT(S), PPT(R), and PPD(S) can inhibit cell proliferation while PPD(R) does not suppress cell growth at available concentration. Further analysis of transactivation and transrepression activities indicates that PPD(R) can repress the transcription of GR target transrepressed gene without activating the expression of the GR target transactivated gene. Results of molecular docking suggest that PPD(R) yields more hydrogen bond interactions and a lower binding energy than its counterparts, resulting in tighter binding between PPD(R) and GR. In addition, PPD(R) achieves stability in the pocket after 2 ns, thereby facilitating exerting its regulatory role of GR target genes. By contrast, other ginsenosides fluctuate drastically during the simulations. In conclusion, PPD(R) may serve as a potential selective GR modulator (SEGRM).

Functionalization of amino terminated carbon nanotubes with isocyanates for magnetic solid phase extraction of sulfonamides from milk and their subsequent determination by liquid chromatography-high resolution mass spectrometry.

A simple modification method was developed for the functionalization of amino terminated carbon nanotubes (CNT-NH2) by using isocyanates as modifiers via the nucleophilic addition reaction. Two types of functionalized magnetic carbon nanotubes (MCNT) were prepared through deposition of magnetic nanoparticles on CNT-NH2 and modification with different isocyanates. p-Tolyl-functionalized MCNT (Tol-MCNT) with better adsorption performance were selected as adsorbent for magnetic solid phase extraction (MSPE), which could extract sulfonamides (SAs) from various milk samples with a enrichment factor of about 30 after optimization. By combining the MSPE with liquid chromatography-high resolution mass spectrometry (LC-HRMS), a new method was developed. Both skimmed and whole milk samples of three brands were analyzed with this method, and 4 SAs including sulfadiazine, sulfisomidine, sulfamethazine and sulfameter were detected with the concentration from unquantifiable to 72 ng/L, which were all well below the maximum residue limits in milk according to the regulations of China and EU.

Effect of Multi-walled Carbon Nanotubes on the Toxicity of Triphenyltin to the Marine Copepod Tigriopus japonicus.

Marine organisms are often exposed to a mixture of various pollutants in marine environment (i.e., nanoparticles, organic pollutants). The present study investigated the potential effects of multi-walled carbon nanotubes (MWCNTs) on the toxicity of triphenyltin chloride (TPTCl). The results revealed an antagonistic interaction between MWCNTs and TPTCl on the copepod through 96 h acute exposure, which was attributed to the adsorption of TPTCl to MWCNTs and aggregation of MWCNTs in the test solutions. Results of 21 days' chronic exposure showed that the effect concentration of MWCNTs could be 100 times lower than that of acute exposure. The exposure to binary mixture of MWCNT (1.0 mg/L) and TPTCl (0.3 µg/L) caused a reduction by 94% for the 3rd time spawning and 83% for the total number of hatched nauplii. The ingestion and exterior attachment of MWCNTs to the copepod might be the main reasons causing the adverse effect in reproduction.

Association between mitochondrial DNA copy number and cardiovascular disease: Current evidence based on a systematic review and meta-analysis.

BACKGROUND: Mitochondria are energy-producing structure of the cell and help to maintain redox environment. In cardiovascular disease, the number of mitochondrial DNA (mtDNA) will changes accordingly compare to normal condition. Some investigators ask whether it has a clear association between mtDNA and cardiovascular disease with its adverse events. Thus, we conduct the meta-analysis to assess the role of circulating mtDNA in evaluating cardiovascular disease. METHODS: The meta-analysis was conducted in accordance with a predetermined protocol following the recommendations of Cochrane Handbook of Systematic Reviews. We searched the Pubmed, Embase, the Cochrane Central Register of Controlled Trials and World Health Organization clinical trials registry center to identify relevant studies up to the end of October 2017. Data were analyzed using STATA. Besides, publication bias and meta-regression analysis were also conducted. RESULTS: We collected results from 5 articles for further analyses with 8,252 cases and 20,904 control. The normalized mtDNA copy number level is lower in cardiovascular disease (CVD) than the control groups with a pooled standard mean difference (SMD) of -0.36(95%CI,-0.65 to -0.08); The pooled odds ratio (OR) for CVD proportion associated with a 1-SD (standard deviation) decrease in mtDNA copy number level is 1.23 (95% CI,1.06-1.42); The OR for CVD patients with mtDNA copy number lower than median level is 1.88(95% CI,1.65-2.13); The OR for CVD patients with mtDNA copy number located in the lowest quartile part is 2.15(95% CI, 1.46-3.18); the OR between mtDNA copy number and the risk of sudden cardiac death (SCD) is 1.83(95% CI, 1.22-2.74). CONCLUSION: Although inter-study variability, the overall performance test of mtDNA for evaluating CVD and SCD revealed that the mtDNA copy number presented the potential to be a biomarker for CVD and SCD prediction. Given that, the fewer copies of mtDNA, the higher the risk of CVD.