Hydrothermal and anion exchange synthesis of Mn(V)-doped Ba5(PO4)3Cl nano-apatite toward NIR-II temperature sensing.

The second near-infrared window (NIR-II) in the range of 1000-1400 nm is ideal for in vivo imaging and sensing through reduced scattering, absorption, and autofluorescence. However, there are only a few nanophosphor systems with emission in the NIR-II region. Here, we report on Mn5+-doped Ba5(PO4)3Cl nanoparticles (BPCl:Mn5+ NPs, d < 50 nm) toward NIR-II temperature sensing. BPCl:Mn5+ NPs are made by a two-step (hydrothermal and anion exchange) method. XRD, SEM, and TEM results showed that the as-prepared BPCl:Mn5+ NPs show high crystallinity, uniform size, and sphere-like morphology. The nanoparticles exhibit a broad excitation band of 500-850 nm and a temperature-sensitive peak emission at 1175 nm in the NIR-II range. NIR-II temperature sensing by 1E emission intensity is demonstrated with good linear fitting (R2 = 0.9895), high sensitivity (2.30% at 373 K), and good repeatability (99.0%). Thus, our study provides a path to develop a new NIR-II thermometer based on tetrahedral Mn(V) coordination.

Molecular characterization and functional analysis of glutathione S-transferase genes of pine wood nematode (Bursaphelenchus xylophilus) for avermectin.

Pine wilt disease (PWD), caused by Bursaphelenchus xylophilus (pine wood nematodes, PWNs), is a forest disease that seriously threatens the health of Pinus forestry. Glutathione S-transferases (GSTs) play important roles in xenobiotic metabolism, lipophilic compound transport, antioxidative stress reactions, anti-mutagenesis, and antitumor activity. The analysis and investigation of the specific functions of GSTs in the metabolism of toxic substances in nematodes are important for identifying potential target genes to control the spread and transmission of B. xylophilus. In this study, 51 Bx-GSTs were found in the genome of B. xylophilus. Two key Bx-gsts (Bx-gst12 and Bx-gst40) were analyzed when B. xylophilus was exposed to avermectin. The expression of Bx-gst12 and Bx-gst40 was significantly increased when B. xylophilus was exposed to 1.6 and 3.0 mg/mL avermectin solutions. Notably, combined silencing of both Bx-gst12 and Bx-gst40 did not further increase the mortality rates under avermectin exposure. Mortality rates were significantly increased in nematodes treated with dsRNA compared to control nematodes (p < 0.05) after RNAi. The feeding ability of nematodes was also significantly reduced after treatment with dsRNA. These results suggested that Bx-gsts are associated with the detoxification process and feeding behavior of B. xylophilus. Silencing Bx-gsts leads to increased susceptibility to nematicides and reduces the feeding ability of B. xylophilus. Therefore, Bx-gsts will be a new control target of PWNs in the future.

Manganese Local Environment Modulation via SiO4 Substitution to Boost Sodium Storage Performance of Na4 MnCr(PO4 )3.

Manganese-based Na superionic conductors (NASICONs) Na4 MnCr(PO4 )3 with three-electron reaction are attractive cathode materials for sodium-ion batteries. However, the irreversible distortion of Mn local structure leads to sluggish electrode kinetics, voltage hysteresis, and poor cycling stability. Here, SiO4 is introduced to substitute PO4 to modulate the local environment of Mn to activate the redox activity and stabilize the reversibility of Na4 MnCr(PO4 )2.9 (SiO4 )0.1 (NMCP-Si). A combined experimental and theoretical investigation have been undertaken to reveal the evolution of electronic structures and Na storage properties associated with SiO4 substitution. The NMCP-Si exhibits much-enhanced rate capability and cycling stability, being attributed to the unique Jahn-Teller distortion (Mn3+ ) that facilitates sodium de/insertion kinetics by optimizing the Na ion diffusion channels. This work addresses the challenge of stabilizing the structure of Mn-based NASICONs and represents a breakthrough in understanding how to improve the Na+ conductivity by regulating local structure.

Anticipating Z-generation tourists' green hotel visit intention utilizing an extended theory of planned behavior.

Due to the effect COVID-19 epidemic, promoting green consumption is now a key marketing strategy in the hospitality and tourism industry. As it is vital green hotels predict their customers' visit intention, this study attempts to discover the factors affecting Taiwan's Z-generation tourists' green hotel visit intention using an extended theory of planned behavior [including personal moral norms (PMN) and environmental concern (EC)]. Data were gathered from 296 Z-generation tourists via an online survey, which was subsequently analyzed using partial least squares structural equation modeling. The results evidence that Z-generation tourists' attitude, subjective norms, (SN) and perceived behavioral control positively and significantly influence their green hotel visit intention, with attitude being the most significant factor. Moreover, the mediation model analysis indicates Z-generation tourists' attitude toward green hotels mediates the relationships between PMN, SN, EC, and visit intention. This study provides new insights into tourists' green hotel visit intention and emphasizes the importance of attitude in the formation of intention.

Nonaqueous Electroextraction with Tunable Selectivity for Direct, Fast, and Exhaustive Enrichment of Per- and Polyfluoroalkyl Acids from Oils and Food Contact Materials.

Widespread concerns have been raised due to the ever-increasing number of novel per- and polyfluoroalkyl acids (PFAAs) and the ever-decreasing level of legacy PFAAs. Most analytical methods for PFAAs suffer from a narrow range of analyzable PFAAs, insufficient sensitivity, poor performance for oil samples, and defective quantification without internal standards or blank matrices. To solve these challenges, a highly selective method for multiple PFAAs from oils and food contact materials (FCMs) was developed based on nonaqueous electroextraction (NE). Through theoretical derivation and experimental investigation, the selectivity of NE was discovered to be tunable, and the range of extractable analytes could be tuned by adjusting the dielectric constant of the sample solution. For PFAAs, the selectivity was attributed to the pKa-based differential migration mechanism, as PFAAs exhibited less variable pKa values in different solvents compared to interference components. The method achieved nonmatrix-matched calibration without internal standards and integration of sample cleanup, selective extraction, and exhaustive enrichment into a fast and convenient operation. The method provided low limits of detection (0.002-0.03 µg·kg-1), satisfactory accuracy (88.0-107.8%), and RSDs (<11.7%). Migration experiments from 33 FCMs to oils were further investigated. PFBS (<0.05-2.34 µg·kg-1) and PFBA (<0.2-0.398 µg·kg-1) were detected from most FCMs. This was the first attempt at PFAA analysis as well as oil sample analysis using an electric field-assisted extraction technique and also the first report on PFAA migration from FCMs into edible oils.

Combined Therapy of Probiotic Microcapsules and Bomidin in Vibrio parahaemolyticus-Infected Rats.

BACKGROUND: With the discovery of more and more drug-resistant bacterial strains, there is an urgent need for safer and more effective alternative treatments. In this study, antibacterial peptides and probiotic microcapsules were combined to treat gastrointestinal inflammation caused by Vibrio parahaemolyticus infection. METHODS: To improve the stability of probiotics in the gastrointestinal tract, two types of mixed natural anionic polysaccharides and chitosan were used as carriers to embed the probiotics. Taking Lacticaseibacillus casei CGMCC1.8727 microcapsules with good performance as the research object, the in vitro characteristics of the microcapsules were studied via acid resistance test and intestinal release test. The microcapsules were then tested for in vivo treatment in combination with the antibacterial peptide, bomidin, and the therapeutic effects were compared among microencapsulated probiotics, free probiotics, and probiotics in combination with bomidin. RESULTS: Microencapsulation was successfully manufactured under suitable processing parameters, with the product particle size being 2.04 ± 0.2743 mm. Compared with free probiotics, microencapsulation significantly improved the activity and preservation stability of the probiotics under simulated gastrointestinal conditions. Microencapsulated probiotics showed better therapeutic effects than free probiotics in vivo. Microcapsules combined with antimicrobial peptides accelerated the elimination of bacteria in vivo. This study provides a reference for anti-inflammatory treatment, especially for the treatment of gastrointestinal diseases.

Functional Study on Cytochrome P450 in Response to L(-)-Carvone Stress in Bursaphelenchus xylophilus.

Bursaphelenchus xylophilus (PWN) causes pine wilt disease (PWD), which is one of the most devastating pine diseases worldwide. Cytochrome P450 (CYP) catalyzes the biosynthetic metabolism of terpenoids and plays an important role in the modification of secondary metabolites in all living organisms. We investigated the molecular characteristics and biological functions of Bx-cyp29A3 in B. xylophilus. The bioinformatics analysis results indicated that Bx-cyp29A3 has a transmembrane domain and could dock with L(-)-carvone. The gene expression pattern indicated that Bx-cyp29A3 was expressed in 0.2, 0.4, 0.6, 0.8, and 1.0 mg/mL L(-)-carvone solutions. The Bx-cyp29A3 expression increased in a dose-dependent manner and peaked at 24 h of exposure when the L(-)-carvone solution concentration was 0.8 mg/mL. However, the gene expression peaked at 0.6 mg/mL after 36 h. Furthermore, RNA interference (RNAi) indicated that Bx-cyp29A3 played an essential role in the response to L(-)-carvone. The mortality rates of the Bx-cyp29A3 knockdown groups were higher than those of the control groups in the 0.4, 0.6, 0.8, and 1.0 mg/mL carvone solutions after 24 h of exposure or 36 h of exposure. In summary, bioinformatics provided the structural characteristics and conserved sequence properties of Bx-cyp29A3 and its encoded protein, which provided a target gene for the study of the P450 family of B. xylophilus. Gene silencing experiments clarified the function of Bx-cyp29A3 in the immune defense of B. xylophilus. This study provides a basis for the screening of new molecular targets for the prevention and management of B. xylophilus.

Gene sdaB Is Involved in the Nematocidal Activity of Enterobacter ludwigii AA4 Against the Pine Wood Nematode Bursaphelenchus xylophilus.

Bursaphelenchus xylophilus, a plant parasitic nematode, is the causal agent of pine wilt, a devastating forest tree disease. Essentially, no efficient methods for controlling B. xylophilus and pine wilt disease have yet been developed. Enterobacter ludwigii AA4, isolated from the root of maize, has powerful nematocidal activity against B. xylophilus in a new in vitro dye exclusion test. The corrected mortality of the B. xylophilus treated by E. ludwigii AA4 or its cell extract reached 98.3 and 98.6%, respectively. Morphological changes in B. xylophilus treated with a cell extract from strain AA4 suggested that the death of B. xylophilus might be caused by an increased number of vacuoles in non-apoptotic cell death and the damage to tissues of the nematodes. In a greenhouse test, the disease index of the seedlings of Scots pine (Pinus sylvestris) treated with the cells of strain AA4 plus B. xylophilus or those treated by AA4 cell extract plus B. xylophilus was 38.2 and 30.3, respectively, was significantly lower than 92.5 in the control plants treated with distilled water and B. xylophilus. We created a sdaB gene knockout in strain AA4 by deleting the gene that was putatively encoding the beta-subunit of L-serine dehydratase through Red homologous recombination. The nematocidal and disease-suppressing activities of the knockout strain were remarkably impaired. Finally, we revealed a robust colonization of P. sylvestris seedling needles by E. ludwigii AA4, which is supposed to contribute to the disease-controlling efficacy of strain AA4. Therefore, E. ludwigii AA4 has significant potential to serve as an agent for the biological control of pine wilt disease caused by B. xylophilus.

Guanylate-Binding protein 2b regulates the AMPK/mTOR/ULK1 signalling pathway to induce autophagy during Mycobacterium bovis infection.

Autophagic isolation and degradation of intracellular pathogens are employed by host cells as primary innate immune defense mechanisms to control intercellular M. bovis infection. In this study, RNA-Seq technology was used to obtain the total mRNA from bone marrow-derived macrophages (BMDMs) infected with M. bovis at 6 and 24 h after infection. One of the differential genes, GBP2b, was also investigated. Analysis of the significant pathway involved in GBP2b-coexpressed mRNA demonstrated that GBP2b was associated with autophagy and autophagy-related mammalian target of rapamycin (mTOR) signaling and AMP-activated protein kinase (AMPK) signaling. The results of in vivo and in vitro experiments showed significant up-regulation of GBP2b during M. bovis infection. For in vitro validation, small interfering RNA-GBP2b plasmids were transfected into BMDMs and RAW264.7 cells lines to down-regulate the expression of GBP2b. The results showed that the down-regulation of GBP2b impaired autophagy via the AMPK/mTOR/ULK1 pathway, thereby promoting the intracellular survival of M. bovis. Further studies revealed that the activation of AMPK signaling was essential for the regulation of autophagy during M. bovis infection. These findings expand the understanding of how GBP2b regulates autophagy and suggest that GBP2b may be a potential target for the treatment of diseases caused by M. bovis.

Ultrasound-assisted micellar cleanup coupled with large-volume-injection enrichment for the analysis of polar drugs in blood and zebrafish samples.

A novel ultrasound-assisted micellar cleanup strategy (UAMC) coupled with large volume injection (LVI) high performance liquid chromatography (HPLC) method was proposed and successfully applied to the analysis of cefathiamidine in complex biological samples such as whole blood, plasma, serum and even zebrafish, a challenging positive real sample. Based on the micelle-biomacromolecule interaction, the phase-separation feature of surfactant micelles and ultrasound cavitation, UAMC possessed an impressive matrix cleanup capability and could rapidly reach distribution equilibrium (approximately 2 min), which enabled simultaneous sample cleanup and analyte extraction within 8 min. Due to the high cleanup efficiency of UAMC, large volume of pretreated samples could be injected for analysis without peak broadening, impurity interference and column degradation. Thus, online analyte enrichment could be automatically performed to significantly improve method sensitivity by the column-switching LVI-HPLC system, a commercial HPLC system with small modifications. The UAMC-LVI-HPLC method creatively integrated sample cleanup, analyte extraction and on-column enrichment into simple operation. In addition, the UAMC-LVI-HPLC method enabled non-matrix-matched analysis of cefathiamidine in complex biological samples. This feature was helpful to address the problems caused by conventional matrix-matched or internal standard calibration methods, such as matrix bias, increased workload, limited availability of suitable blank matrices and the use of expensive internal standards. The method had low limits of detections (e.g., 0.0051 mg/L and 0.038 µg/g), wide linear ranges (0.030-100 mg/L and 0.15-489 µg/g), good linear correlation (R2 = 0.9999), satisfactory accuracy (97.6-109.7%) and excellent intra- and interday precision (0.5-4.9%). Thus, UAMC-LVI-HPLC is expected to be a promising candidate for bioanalysis in therapeutic drug monitoring or pharmacokinetic and toxicology studies in the future.

Prebiotic Oligosaccharides Enhance Iron Absorption Via Modulation of Protein Expression and Gut Microbiota in a Dose-Response Manner in Iron-Deficient Growing Rats.

SCOPE: Iron deficiency anemia (IDA) in children is one of the most common nutrition-related health conditions worldwide. Prebiotic oligosaccharides, fructo-oligosaccharide (FOS) and galacto-oligosaccharides (GOS), have shown to affect iron absorption in anemic subjects, but the results in previous studies are inconsistent, thus the underlying mechanism and the effective dose of GOS in mitigating anemia remain unclear. METHODS AND RESULTS: The present study aims to investigate the mechanism of how GOS/FOS affect iron absorption in an iron-deficient growing rat model from the perspectives of protein expression and gut microbiota, and determine the optimum dose of GOS. Iron-deficient models are established by providing young rats diet without iron addition for 14 days. Later, iron-deficient rats are provided with standard rat chows supplemented with 0%, 3%, 5%, 10% GOS, and 10% FOS for 21 days. The results show that ≥5% GOS supplementation in diet improves iron status and significantly impacts iron-binding/transport protein expression. Furthermore, a dose-dependent modulating effect of GOS on gut microbiota is determined. CONCLUSION: For the first time, the present study provides evidence that GOS supplementation induces a dose-response effect on iron absorption and gut microbiota in the established model, suggesting a positive role of GOS in ameliorating IDA in children.

Hepatitis B virus detected in a golden monkey fatal case, China.

Hepatitis B virus (HBV) is distributed worldwide and poses a significant threat to human health. Cross-species transmission of HBV from human to non-human primates could occur, which has been confirmed in three individual events. In this study, HBV DNA was detected in one golden monkey fatal case in China. The following genetic sequencing and analysis demonstrated the virus had a close genetic relationship with HBV genotype C in humans. To our knowledge, this is the first report suggested that HBV is related with a non-human primate fatal case in China.

Bioaccessibility and bioavailability adjusted dietary exposure of cadmium for local residents from a high-level environmental cadmium region.

The critical health risks caused by cadmium (Cd) via dietary exposure are commonly assessed by detecting Cd concentrations in foods. Differently, in this study, the bioaccessibility and bioavailability of Cd in major local harvests were introduced to assess the dietary exposure of local residents from a high-level environmental Cd region. The results indicated that certain Cd was released into the digestive juice after in vitro digestion with a bioaccessibility of 20-63% for rice and 3-32% for leafy vegetables, and the released portion was partially absorbed by Caco-2 cells with a bioavailability of 2-21% for rice and 0.2-13% for leafy vegetables. The results obtained from the toxicokinetic model revealed that the predicted urinary Cd values from the estimated daily intake (EDI) of Cd, which accounted for bioaccessibility and bioavailability, were consistent with the actual measured values, and the EDIs were considerably lower than the acceptable daily intake. This suggests that the bioaccessibility and bioavailability adjusted dietary Cd exposure should be more precise. The key issues addressed in our study implores that a potential health risk cannot be neglected in people with high consumption of rice from high-level zone.

Molecular characterization and functional analysis of multidrug resistance-associated genes of Pinewood nematode (Bursaphelenchus xylophilus) for nematicides.

Bursaphelenchus xylophilus (Pinewood nematode, PWN) is the causative agent of pine wilt disease (PWD) which caused serious threat to pine forests in the world, especially in East Asia and Western Europe. At present, the control of PWD mainly rely on the massive use of pesticide despite the damage to human health and environmental safety. Developing novel drug targets is the optimized strategy for developing new method to control PWN. In this study, four multidrug resistance-associated protein (MRP) genes containing highly conserved MRP-associated domains were cloned from PWN. The expression patterns of the four Bx-mrps under three different nematicides treatments were studied by quantitative reverse transcription PCR (qRT-PCR) and the function of the four genes in multidrug resistance were also validated by RNA interference (RNAi). Results showed that the expression of Bx-mrp1, Bx-mrp2, Bx-mrp3, and Bx-mrp4 were significantly increased when exposed to different nematicides, wherein, Bx-mrp4 exposed by 4.0 mg/mL of matrine own the highest expression level. The mortality rates of Bx-mrps silenced nematodes revealed significant increase(P < 0.05)under matrine, avermectin, and emamectin benzoate exposure. Specially, Bx-mrp4 exposed with 4.0 mg/mL matrine for 24 h own the highest mortality increase by 18.34%. After RNAi of Bx-mrps, feeding ability of the nematodes were also significantly decreased. These results demonstrate that Bx-mrps were linked to the detoxification process and feeding behavior of PWN. Silencing of Bx-mrps can lead to increased sensitivity of PWN to nematicides and decrease its feeding ability. Bx-mrps are potential new PWN control targets in the future.

The associations of gut microbiota and fecal short-chain fatty acids with bone mass were largely mediated by weight status: a cross-sectional study.

PURPOSE: We aimed to investigate whether the gut microbiota and fecal short-chain fatty acids (SCFAs) are associated with bone mass in healthy children aged 6-9 years. METHODS: In this study, 236 healthy children including 145 boys and 91 girls were enrolled. 16S rRNA gene sequencing was used to characterize the composition of their gut microbiota. Total and 10 subtypes of SCFAs in the fecal samples were determined by high-performance liquid chromatography. Dual X-ray absorptiometry was used to measure the bone mineral density (BMD) and bone mineral content (BMC) for total body (TB) and total body less head (TBLH). Z score of TBLH BMD was calculated based on the recommended reference. RESULTS: Four gut microbiota principal components (PCs) were identified by the compositional principal component analysis at the genus level. After adjustment of covariates and controlling for the false discovery rate, multiple linear regression analysis showed that PC3 score (positive loadings on genera Lachnoclostridium and Blautia) was significantly negatively associated with TBLH BMD/BMC/Z score, TB BMC and pelvic BMD (ß: - 0.207 to - 0.108, p: 0.002-0.048), whereas fecal total and several subtypes of SCFAs were correlated positively with TBLH BMD/Z score and pelvic BMD (ß: 0.118-0.174, p: 0.038-0.048). However, these associations disappeared after additional adjustment for body weight. Mediation analysis suggested that body weight significantly mediated 60.4% and 78.0% of the estimated association of PC3 score and SCFAs with TBLH BMD Z score, respectively. CONCLUSIONS: The associations of gut microbiota composition and fecal SCFA concentrations with bone mass in children were largely mediated by body weight.

Leader-member exchange fosters nurses' job and life satisfaction: The mediating effect of job crafting.

This study aims to evaluate the effects of leader-member exchange (LMX) on job and life satisfaction among nurses in China and to examine the mediating effect of individual and collaborative job crafting between LMX and job and life satisfaction. The study recruited 263 nurses who worked in hospitals in Zhejiang province, China. A set of self-administered questionnaires were used to measure the variables of LMX, job crafting, job and life satisfaction. The data was analyzed using the partial least square structural equation modelling (PLS-SEM). The results reveal that LMX has a significant positive influence on job crafting and job satisfaction. Collaborative job crafting has a significant positive influence on the job satisfaction of nurses, whereas individual job crafting does not. Moreover, LMX will affect job satisfaction and life satisfaction through a partial mediating effect of both individual and collaborative job crafting. Finally, the article discusses the academically and practical implications, and also provide some suggestions and directions for the future research.

Occurrence and dietary exposure assessment of pentachlorophenol in livestock, poultry, and aquatic foods marketed in Guangdong Province, China: Based on food monitoring data from 2015 to 2018.

As a persistent organic pollutant, pentachlorophenol (PCP) has serious impacts on human health. However, its presence in animal source food products sold in the Guangdong Province (GD) of China, and the resultant dietary exposure have not been elucidated. To address this gap, 3,100 samples from seven food categories, including beef, pork, mutton, offals, broilers, hen eggs, and farmed freshwater fish, marketed throughout four geographical regions of GD, were collected from 2015 to 2018. Gas chromatography coupled with mass spectrometry was employed to detect PCP levels in these food matrices. PCP was found in all food categories, but the average contamination levels were low, ranging from 0.40 µg/kg wet weight (ww) (hen eggs) to 5.85 µg/kg ww (offals). However, higher concentrations of PCP were detected (P < 0.05) in animal source food from the North region. Additionally, a temporal declining trend was observed in this four-year consecutive survey. The estimated human dietary exposure of PCP to population groups, including the general population and subgroups (male and female, children, and adults), was found to be far below the permissible daily intake (3 µg/kg body weight). Therefore, the health impacts of PCP should be correspondingly low for local residents, based on current toxicological knowledge. Regional exposure patterns varied due to different extents of contamination in the four areas, and pork, broilers, and freshwater fish were the major sources of dietary PCP exposure. PRACTICAL APPLICATION: As a persistent organic pollutant, pentachlorophenol (PCP) has serious impacts on human health. However, its presence in animal source food products sold in Guangdong Province of China, and the resultant dietary exposure have not been elucidated. In this study, we conducted an in-depth investigation on the occurrence of PCP in major foodstuff categories, including beef, pork, mutton, broilers, offals, hen eggs, and farmed freshwater fish, marketed in all 21 prefecture-level divisions of Guangdong Province, in order to provide integral insights for regulatory authorities.

Recent progress in two-dimensional materials for terahertz protection.

With the wide applications of terahertz (THz) devices in future communication technology, THz protection materials are essential to overcome potential threats. Recently, THz metamaterials (MMs) based on two-dimensional (2D) materials (e.g., graphene, MXenes) have been extensively investigated due to their unique THz response properties. In this review, THz protection theories are briefly presented first, including reflection loss and shielding mechanisms. Then, the research progress of graphene and other 2D material-based THz MMs and intrinsic materials are reviewed. MMs absorbers in the forms of single layer, multiple layers, hybrid and tunable metasurfaces show excellent THz absorbing performance. These studies provide a sufficient theoretical and practical basis for THz protection, and superior properties promised the wide application prospects of 2D MMs. Three-dimensional intrinsic THz absorbing materials based on porous and ordered 2D materials also show exceptional THz protection performance and effectively integrate the advantages of intrinsic properties and the structural characteristics of 2D materials. These special structures can optimize the surface impedance matching and enable multiple THz scatterings and electric transmission loss, which can realize high-efficiency absorption loss and active controllable protection performance in ultra-wide THz wavebands. Finally, the advantages and existing problems of current THz protection materials are summarized, and their possible future development and applications are prospected.

Nonaqueous Miscible Liquid-Liquid Electroextraction for Fast Exhaustive Enrichment of Ultratrace Analytes by an Exponential Transfer and Deceleration Mechanism.

Conventional electrical-field-assisted sample preparation (EFASP) methods rely on analyte transfer between immiscible phases and require at least one aqueous phase in contact with the electrode. In this paper, we report a novel nonaqueous miscible liquid-liquid electroextraction (NMLEE) technique that enables fast exhaustive enrichment of ultratrace analytes from a milliliter-level donor in a vial to a microliter-level acceptor in a tube. Miscible nonaqueous solvents are used for the donor and acceptor to overcome common EFASP problems such as high charge or mass transfer resistance, loss of analytes in the membrane phase, water electrolysis, back-extraction, bubble generation, and difficulties in the application of high voltage for fast migration. According to theoretical derivation and experimental verification results, the concentrations of analytes in the donor and their migration velocity in the acceptor both decrease exponentially with time, and the extraction recovery correlates linearly with the current variation. These mechanisms result in efficient enrichment by forming an analyte-enriched zone and allow the extraction progress and recovery to be monitored and estimated based on the current variation. NMLEE was coupled with liquid chromatography-mass spectrometry to analyze 10 amphetamine-type drugs, atropine, nortriptyline, and methadone in blood and urine samples. This method provided low limits of detection (0.003-0.1 ng·mL-1), satisfactory extraction recoveries (89.6-104.1%), and RSDs (<12.3% for intraday and <8.8% for interday), which met the requirements of the ICH guidelines. This study may contribute to the further development of EFASP methods for effective ultratrace analyses in forensic science.

Associations of Plasma Copper, Magnesium, and Calcium Levels with Blood Pressure in Children: a Cross-sectional Study.

Studies of the relationship of copper (Cu), magnesium (Mg), and calcium (Ca) levels with blood pressure in children are limited. This cross-sectional study included 443 children aged 6-9 years from Guangzhou, China. Plasma concentrations of Cu, Mg, and Ca were measured by inductively coupled plasma mass spectrometry. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured with an electronic sphygmomanometer. Elevated SBP and DBP were defined as the 90th percentile or greater (age and sex specific) of reference values for Chinese children. Abnormal blood pressure (ABP) was defined as an elevated SBP and/or DBP. The plasma Cu concentration was positively correlated with blood pressure, body mass index (BMI), and the C-reactive protein (CRP) level, whereas the plasma Mg and Ca concentrations were negatively correlated with SBP. A higher Cu concentration (T3 vs. T1) was associated with a higher risk of ABP (odds ratio (OR) 2.55, 95% confidence interval (CI) 1.20 to 5.40). In contrast, children in the top tertiles of Mg (OR 0.42, 95% CI 0.18 to 0.98) and Ca (OR 0.28, 95% CI 0.11 to 0.70) concentrations showed lower risks of ABP than those in the bottom tertiles. Path analysis showed that the CRP levels and BMI mediated the associations between the Cu concentration and ABP. We found that higher plasma Mg and Ca concentrations were negatively related to blood pressure in children aged 6-9 years. In contrast, a higher plasma Cu concentration was positively correlated with the risk of ABP, and the association was mediated by CRP and BMI.