Relationship between the microenvironment and survival in kidney transplantation: a bibliometric analysis from 2013 to 2023.

Background: Kidney transplantation is considered the most effective treatment for end-stage renal failure. Recent studies have shown that the significance of the immune microenvironment after kidney transplantation in determining prognosis of patients. Therefore, this study aimed to conduct a bibliometric analysis to provide an overview of the knowledge structure and research trends regarding the immune microenvironment and survival in kidney transplantation. Methods: Our search included relevant publications from 2013 to 2023 retrieved from the Web of Science core repository and finally included 865 articles. To perform the bibliometric analysis, we utilized tools such as VOSviewer, CiteSpace, and the R package "bibliometrix". The analysis focused on various aspects, including country, author, year, topic, reference, and keyword clustering. Results: Based on the inclusion criteria, a total of 865 articles were found, with a trend of steady increase. China and the United States were the countries with the most publications. Nanjing Medical University was the most productive institution. High-frequency keywords were clustered into 6 areas, including kidney transplantation, transforming growth factor ß, macrophage, antibody-mediated rejection, necrosis factor alpha, and dysfunction. Antibody mediated rejection (2019-2023) was the main area of research in recent years. Conclusion: This groundbreaking bibliometric study comprehensively summarizes the research trends and advances related to the immune microenvironment and survival after kidney transplantation. It identifies recent frontiers of research and highlights promising directions for future studies, potentially offering fresh perspectives to scholars in the field.

Deep learning assists detection of esophageal cancer and precursor lesions in a prospective, randomized controlled study.

Endoscopy is the primary modality for detecting asymptomatic esophageal squamous cell carcinoma (ESCC) and precancerous lesions. Improving detection rate remains challenging. We developed a system based on deep convolutional neural networks (CNNs) for detecting esophageal cancer and precancerous lesions [high-risk esophageal lesions (HrELs)] and validated its efficacy in improving HrEL detection rate in clinical practice (trial registration ChiCTR2100044126 at www.chictr.org.cn). Between April 2021 and March 2022, 3117 patients ≥50 years old were consecutively recruited from Taizhou Hospital, Zhejiang Province, and randomly assigned 1:1 to an experimental group (CNN-assisted endoscopy) or a control group (unassisted endoscopy) based on block randomization. The primary endpoint was the HrEL detection rate. In the intention-to-treat population, the HrEL detection rate [28 of 1556 (1.8%)] was significantly higher in the experimental group than in the control group [14 of 1561 (0.9%), P = 0.029], and the experimental group detection rate was twice that of the control group. Similar findings were observed between the experimental and control groups [28 of 1524 (1.9%) versus 13 of 1534 (0.9%), respectively; P = 0.021]. The system's sensitivity, specificity, and accuracy for detecting HrELs were 89.7, 98.5, and 98.2%, respectively. No adverse events occurred. The proposed system thus improved HrEL detection rate during endoscopy and was safe. Deep learning assistance may enhance early diagnosis and treatment of esophageal cancer and may become a useful tool for esophageal cancer screening.

Functional study of the soybean stamen-preferentially expressed gene GmFLA22a in regulating male fertility.

China has a high dependence on soybean imports, yield increase at a faster rate is an urgent problem that need to be solved at present. The application of heterosis is one of the effective ways to significantly increase crop yield. In recent years, the development of an intelligent male sterility system based on recessive nuclear sterile genes has provided a potential solution for rapidly harnessing the heterosis in soybean. However, research on male sterility genes in soybean has been lagged behind. Based on transcriptome data of soybean floral organs in our research group, a soybean stamen-preferentially expressed gene GmFLA22a was identified. It encodes a fasciclin-like arabinogalactan protein with the FAS1 domain, and subcellular localization studies revealed that it may play roles in the endoplasmic reticulum. Take advantage of the gene editing technology, the Gmfla22a mutant was generated in this study. However, there was a significant reduction in the seed-setting rate in the mutant plants at the reproductive growth stage. The pollen viability and germination rate of Gmfla22a mutant plants showed no apparent abnormalities. Histological staining demonstrated that the release of pollen grains in the mutant plants was delayed and incomplete, which may due to the locule wall thickening in the anther development. This could be the reason of the reduced seed-setting rate in Gmfla22a mutants. In summary, our study has preliminarily revealed that GmFLA22a may be involved in regulating soybean male fertility. It provides crucial genetic materials for further uncovering its molecular function and gene resources and theoretical basis for the utilization of heterosis in soybean.

Calculation of additional load and deformation of the receiving well enclosure structure caused by shield tunneling.

The bulkhead additional thrust during shield tunneling, the force of friction between shield and soil, and the additional grouting pressure can cause additional stress in the surrounding soil, thereby disturbing existing buildings and structures. However, few studies focused on the disturbance situation when the shield tunneling machine approaches the receiving well. If the additional stress and deformation of the receiving well are too excessive, it could result in the collapse of the receiving well. Based on the two-stage method, this study derived the calculation formula of the additional stress and deformation of the receiving well enclosure structure caused by shield tunneling. Taking a shield machine receiving engineering as the context, this study established a numerical simulation model and compared theoretical calculation, the results of numerical simulation model and on-site monitoring data. Finally, the additional stress of the receiving well is analyzed. The research findings demonstrate that the theoretical prediction results, numerical simulation calculation results, and on-site monitoring data exhibit relatively small calculation errors, which validated the applicability of the theoretical prediction formula and numerical simulation model. As the distance between the shield machine and the receiving well decreases, the disturbance to the receiving well increases sharply. When the distance between the cutter head and the receiving well is less than three times the shield length, it is crucial to enhance the deformation monitoring of the receiving well. The primary factors affecting the additional load and deformation of the receiving well enclosure structure are the force of friction between shield and soil and the additional thrust of the cutterhead. The disturbance caused by the additional grouting pressure on the enclosure structure can be ignored.

Work experience of breastfeeding nurses returning to work after maternity leave in Liaoning Province of China: A qualitative study.

AIM: With the implementation of China's three-child policy in 2021, the nurse population faces an increase in the number of breastfeeding nurses returning to work after maternity leave. This study aims to describe the work experience of breastfeeding nurses returning to work after maternity leave. DESIGN: A qualitative descriptive design. METHODS: The data were collected through semi-structured interviews with eight nurses and analysed through Braun and Clarke's thematic analysis. RESULTS: Three themes and nine sub-themes emerged from the analysis of the interviews: changes in nurses (emotional changes, physical changes and changes in work); needs for an improving work environment (needs for a supportive workplace and nurse shortage); support for breastfeeding nurses (support from coworkers, support from the manager, support from the organisation and own need for work). PUBLIC CONTRIBUTION: This study highlighted that breastfeeding nurses need an adjustment period when they return to work after maternity leave. Successful breastfeeding requires support from coworkers, managers and the organisation. In addition, workplace support for breastfeeding and management for nurses needs to be improved.

Reactive oxygen species (ROS) modulate nitrogen signaling using temporal transcriptome analysis in foxtail millet.

Reactive oxygen species (ROS) is a chemically reactive chemical substance containing oxygen and a natural by-product of normal oxygen metabolism. Excessive ROS affect the growth process of crops, which will lead to the decrease of yield. Nitrogen, as a critical nutrient element in plants and plays a vital role in plant growth and crop production. Nitrate is the primary nitrogen source available to plants in agricultural soil and various natural environments. However, the molecular mechanism of ROS-nitrate crosstalk is still unclear. In this study, we used the foxtail millet (Setaria italica L.) as the material to figure it out. Here, we show that excessive NaCl inhibits nitrate-promoted plant growth and nitrogen use efficiency (NUE). NaCl induces ROS accumulation in roots, and ROS inhibits nitrate-induced gene expression in a short time. Surprisingly, low concentration ROS slight promotes and high concentration of ROS inhibits foxtail millet growth under long-term H2O2 treatment. These results may open a new perspective for further exploration of ROS-nitrate signaling pathway in plants.

Field-programmable gate array and deep neural network-accelerated spatial-spectral interferometry for rapid optical dispersion analysis.

Spatial-spectral interferometry (SSI) is a technique used to reconstruct the electrical field of an ultrafast laser. By analyzing the spectral phase distribution, SSI provides valuable information about the optical dispersion affecting the spectral phase, which is related to the energy distribution of the laser pulses. SSI is a single-shot measurement process and has a low laser power requirement. However, the reconstruction algorithm involves numerous Fourier transform and filtering operations, which limits the applicability of SSI for real-time dispersion analysis. To address this issue, this Letter proposes a field-programmable gate array (FPGA)-based deep neural network to accelerate the spectral phase reconstruction and dispersion estimation process. The results show that the analysis time is improved from 124 to 9.27 ms, which represents a 13.4-fold improvement on the standard Fourier transform-based reconstruction algorithm.

Effect of the defoliant tribufos on the reproductive ability of Japanese quail (Coturnix japonica).

As a cotton defoliator, tribufos (S,S,S-tributyl phosphorotrithioate) is widespread in the environment. It can cause neurotoxicity in chickens, reproductive toxicity in rats, and can also cause headaches and nausea in humans. However, little is known about its impact on the reproduction of birds. Here, by analyzing the differences in reproductive indexs and histopathological characteristics, we investigated the chronic effects of 32 mg a.i./kg, 160 mg a.i./kg and 800 mg a.i./kg tribufos treatment on the reproductive ability of Japanese quail (Coturnix japonica). The results indicated that 32 mg a.i./kg and 160 mg a.i./kg tribufos treatment significantly reduced the food intake of quails, significantly increased the broken egg rate, and had adverse effects on gonads and liver tissue. The 160 mg a.i./kg tribufos treatment also significantly reduced the average egg production. Moreover, 800 mg a.i./kg treatment had significant negative effects on feed intake (FI), body weight (BW), eggshell thickness, egg production (EP), fertilization rate, hatchability and progeny 14-d survival rate, and it also significantly increased the broken egg rate. In addition, tribufos exposure caused lesions in quail gonads and liver tissue. Overall, our results revealed that tribufos had adverse effects on the reproductive ability of Japanese quail, especially at high concentrations.

Statins and risks of dementia among patients with heart failure: a population-based retrospective cohort study in Hong Kong.

Background: Heart failure (HF) and dementia frequently co-exist with shared pathological mechanisms and risk factors. Our study aims to investigate the association between statin therapy and the risks of dementia and its subtypes among patients with HF. Methods: The Hong Kong Clinical Data Analysis and Reporting System database was interrogated to identify patients with incident HF diagnosis from 2004 to 2018, using ICD 9/ICD 10 codes. Inverse probability of treatment weighting (IPTW) was used to balance baseline covariates between statin users (N = 54,004) and non-users (N = 50,291). The primary outcomes were incident all-cause dementia, including subtypes of Alzheimer's disease, vascular dementia, and unspecified dementia. Cox proportional-hazard model with competing risk regression was performed to estimate the sub-distribution hazards ratio (SHR) with corresponding 95% confidence intervals (CI) of the risks of all-cause dementia and its subtypes that are associated with statin use. Findings: Of all eligible patients with HF (N = 104,295), the mean age was 74.2 ± 13.6 years old and 52,511 (50.3%) were male. Over a median follow-up of 9.9 years (interquartile range [IQR]: 6.4-13.0), 10,031 (9.6%) patients were diagnosed with dementia, among which Alzheimer's disease (N = 2250), vascular dementia (N = 1831), and unspecified dementia (N = 5950) were quantified separately. After IPTW, statin use was associated with a 20% lower risk of incident dementia compared with non-use (multivariable-adjusted SHR 0.80, 95% CI 0.76-0.84). Stratified by subtypes of dementia, statin use was associated with a 28% lower risk of Alzheimer's disease (SHR 0.72, 95% CI 0.63-0.82), 18% lower risk of vascular dementia (SHR 0.82, 95% CI 0.70-0.95), and a 20% lower risk of unspecified dementia (SHR 0.80, 95% CI 0.75-0.85). Interpretation: In patients with HF, statin use was associated with a significantly lower risk of all-cause dementia and its subtypes, including Alzheimer's disease, vascular dementia, and unspecified dementia. Both randomized trials and experimental studies to validate the potential neuroprotective effect of statin are warranted. Funding: No funding was provided for this study.

Latest advances and clinical application prospects of resveratrol therapy for neurocognitive disorders.

Neurocognitive disorders, such as Alzheimer's disease, vascular dementia, and postoperative cognitive dysfunction, are non-psychiatric brain syndromes in which a significant decline in cognitive function causes great trauma to the mental status of the patient. The lack of effective treatments for neurocognitive disorders imposes a considerable burden on society, including a substantial economic impact. Over the past few decades, the identification of resveratrol, a natural plant compound, has provided researchers with an opportunity to formulate novel strategies for the treatment of neurocognitive disorders. This is because resveratrol effectively protects the brain of those with neurocognitive disorders by targeting some mechanisms such as inflammation and oxidative stress. This article reviews the status of recent research investigating the use of resveratrol for the treatment of different neurocognitive disorders. By examining the possible mechanisms of action of resveratrol and the shared mechanisms of different neurocognitive disorders, treatments for neurocognitive disorders may be further clarified.

Green supply chain management influence on the economic and environmental aspects in China.

In China's rapid industrial development, the adoption and impact of green supply chain practices (GSCP) have become pivotal. This research employs a non-radial, non-angle SBM-DEA model to examine the intricate relationship between environmental sustainability and economic advancement. The observation suggests that companies adopting the global sustainable consumption and production (GSCP) framework demonstrate a more substantial alignment with China's sustainable goals. However, this alignment is accompanied by a fundamental conflict between the need for economic growth and the need for environmental caution. This study highlights China's sincere efforts to adhere to global ecological norms, as the environmental outcomes (ENVO) demonstrated. The findings on organizational culture (O.C.) present a complex depiction of China's direction, highlighting the intersection between its longstanding traditions with the pressing demands of modern environmentally sustainable corporate practices. The presence of regulatory variations across provinces highlights the regional differences within the nation, thus causing organizations to adopt adaptable environmental policies. The complex network of supply chains in China and the careful management of financial resources underscore the diverse range of difficulties and opportunities that firms face. This research ultimately provides a comprehensive understanding of the crucial balancing process that characterizes China's path toward environmental sustainability. It highlights the importance of effectively managing these factors, since it is essential for enterprises to achieve enduring and sustainable success.

A database on the abundance of environmental antibiotic resistance genes.

Antimicrobial resistance (AMR) poses a severe threat to global health. The wide distribution of environmental antibiotic resistance genes (ARGs), which can be transferred between microbiota, especially clinical pathogens and human commensals, contributed significantly to AMR. However, few databases on the spatiotemporal distribution, abundance, and health risk of ARGs from multiple environments have been developed, especially on the absolute level. In this study, we compiled the ARG occurrence data generated by a high-throughput quantitative PCR platform from 1,403 samples in 653 sampling sites across 18 provinces in China. The database possessed 291,870 records from five types of habitats on the abundance of 290 ARGs, as well as 8,057 records on the abundance of 30 mobile genetic elements (MGEs) from 2013 to 2020. These ARGs conferred resistance to major common types of antibiotics (a total of 15 types) and represented five major resistance mechanisms, as well as four risk ranks. The database can provide information for studies on the dynamics of ARGs and is useful for the health risk assessment of AMR.

Causal associations between modifiable risk factors and isolated REM sleep behavior disorder: a mendelian randomization study.

Objectives: This Mendelian randomization (MR) study identified modifiable risk factors for isolated rapid eye movement sleep behavior disorder (iRBD). Methods: Genome-wide association study (GWAS) datasets for 29 modifiable risk factors for iRBD in discovery and replication stages were used. GWAS data for iRBD cases were obtained from the International RBD Study Group. The inverse variance weighted (IVW) method was primarily employed to explore causality, with supplementary analyses used to verify the robustness of IVW findings. Co-localization analysis further substantiated causal associations identified via MR. Genetic correlations between mental illness and iRBD were identified using trait covariance, linkage disequilibrium score regression, and co-localization analyses. Results: Our study revealed causal associations between sun exposure-related factors and iRBD. Utilizing sun protection (odds ratio [OR] = 0.31 [0.14, 0.69], p = 0.004), ease of sunburn (OR = 0.70 [0.57, 0.87], p = 0.001), childhood sunburn occasions (OR = 0.58 [0.39, 0.87], p = 0.008), and phototoxic dermatitis (OR = 0.78 [0.66, 0.92], p = 0.003) decreased iRBD risk. Conversely, a deep skin color increased risk (OR = 1.42 [1.04, 1.93], p = 0.026). Smoking, alcohol consumption, low education levels, and mental illness were not risk factors for iRBD. Anxiety disorders and iRBD were genetically correlated. Conclusion: Our study does not corroborate previous findings that identified smoking, alcohol use, low education, and mental illness as risk factors for iRBD. Moreover, we found that excessive sun exposure elevates iRBD risk. These findings offer new insights for screening high-risk populations and devising preventive measures.

Genomic insights into local adaptation and phenotypic diversity of Wenchang chickens.

Wenchang chicken, a prized local breed in Hainan Province of China renowned for its exceptional adaptability to tropical environments and good meat quality, is deeply favored by the public. However, an insufficient understanding of its population architecture and the unclear genetic basis that governs its typical attributes have posed challenges in the protection and breeding of this precious breed. To address these gaps, we conducted whole-genome resequencing on 200 Wenchang chicken samples derived from 10 distinct strains, and we gathered data on an array of 21 phenotype traits. Population genomics analysis unveiled distinctive population structures in Wenchang chickens, primarily attributed to strong artificial selection for different feather colors. Selection sweep analysis identified a group of candidate genes, including PCDH9, DPF3, CDIN1, and SUGCT, closely linked to adaptations that enhance resilience in tropical island habitats. Genome-wide association studies (GWAS) highlighted potential candidate genes associated with diverse feather color traits, encompassing TYR, RAB38, TRPM1, GABARAPL2, CDH1, ZMIZ1, LYST, MC1R, and SASH1. Through the comprehensive analysis of high-quality genomic and phenotypic data across diverse Wenchang chicken resource groups, this study unveils the intricate genetic backgrounds and population structures of Wenchang chickens. Additionally, it identifies multiple candidate genes linked to environmental adaptation, feather color variations, and production traits. These insights not only provide genetic reference for the purification and breeding of Wenchang chickens but also broaden our understanding of the genetic basis of phenotypic diversity in chickens.

Association between Plasma LRG1 and Lower Cognitive Function in Asians with Type 2 Diabetes Mellitus.

CONTEXT: Leucine-rich α-2-glycoprotein 1 (LRG1) has been implicated in the pathogenesis of diabetic complications, but its association with cognitive function remains unclear. OBJECTIVE: Our primary objective is to investigate the longitudinal association between LRG1 and cognitive function in patients with type 2 diabetes mellitus (T2DM). Secondarily, we determine the causal relationship using Mendelian Randomization (MR), and the role of arterial stiffness as a potential mediator. METHODS: T2DM patients (n = 1039; age = 64.1 ± 6.4 years) were followed-up for 5.3 ± 1.2 years. Plasma LRG1 was measured at baseline using enzyme-linked immunosorbent assay. Baseline and follow-up cognitive function was assessed using Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). One-sample MR was performed with rs4806985 as plasma LRG1-associated single-nucleotide polymorphism (SNP). Mediation analysis was performed to examine if pulse wave velocity (PWV), an arterial stiffness index, mediated the association between plasma LRG1 and follow-up cognitive function. RESULTS: Elevated baseline natural log (Ln)-transformed LRG1 was inversely associated with baseline and follow-up RBANS total score with adjusted coefficients -1.38 (95%CI -2.55 to -0.21; p = 0.021) and -1.38 (95%CI -2.70 to -0.07; p = 0.039), respectively. Genetically-predicted higher levels of plasma LRG1 was associated with lower follow-up RBANS total score with coefficient -7.44 (95%CI -14.14 to -0.74; p = 0.030) per unit increase in LnLRG1. Higher PWV accounted for 27.7% of the association between LnLRG1 and follow-up RBANS total score. CONCLUSIONS: Baseline plasma LRG1 was associated with lower cognitive function at follow-up in patients with T2DM, mediated by PWV. MR analysis provided evidence of an association between genetically influenced plasma LRG1 and lower cognitive function at follow-up.

Anoikis-related signature identifies tumor microenvironment landscape and predicts prognosis and drug sensitivity in colorectal cancer.

Background: Anoikis, a mechanism of programmed apoptosis, plays an important role in growth and metastasis of tumors. However, there are still few available comprehensive reports on the impact of anoikis on colorectal cancer. Method: A clustering analysis was done on 133 anoikis-related genes in GSE39582, and we compared clinical features between clusters, the tumor microenvironment was analyzed with algorithms such as "Cibersort" and "ssGSEA". We investigated risk scores of clinical feature groups and anoikis-associated gene mutations after creating a predictive model. We incorporated clinical traits to build a nomogram. Additionally, the quantitative real-time PCR was employed to investigate the mRNA expression of selected anoikis-associated genes. Result: We identified two anoikis-related clusters with distinct prognoses, clinical characteristics, and biological functions. One of the clusters was associated with anoikis resistance, which activated multiple pathways encouraging tumor metastasis. In our prognostic model, oxaliplatin may be a sensitive drug for low-risk patients. The nomogram showed good ability to predict survival time. And SIRT3, PIK3CA, ITGA3, DAPK1, and CASP3 increased in CRC group through the PCR assay. Conclusion: Our study identified two distinct modes of anoikis in colorectal cancer, with active metastasis-promoting pathways inducing an anti-anoikis subtype, which has a stronger propensity for metastasis and a worse prognosis than an anoikis-activated subtype. Massive immune cell infiltration may be an indicator of anoikis resistance. Anoikis' role in the colorectal cancer remains to be investigated.

Risk factors and prognosis of malignant peritoneal mesothelioma with paraneoplastic syndrome.

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is a rare and highly aggressive tumor. Its clinical manifestations are diverse, and the symptoms are not specific. Some patients will develop paraneoplastic syndrome (PS) during the disease course. This study aims to analyze the risk factors of PS in patients with MPM and their impacts on prognosis. METHODS: The clinical data of MPM patients who underwent cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) at our center from June 2015 to May 2023 were retrospectively analyzed. MPM patients were divided into PS group and non-PS group according to the diagnostic criteria. Univariate and multivariate analyses were performed to explore the risk factors of PS in MPM patients, and to analyze the impact of PS on prognosis. RESULTS: There were 146 MPM patients in this study, including 60 patients (41.1%) with PS and 86 patients (58.9%) without PS. The highest incidence of PS was thrombocytosis (33.6%), followed by neoplastic fever (9.6%). Univariate analysis revealed 8 factors (P < 0.05) with statistically significant differences between the two groups: prior surgical scores, targeted therapy history, Karnofsky performance status score, preoperative carbohydrate antigen (CA) 125 level, vascular tumor embolus, peritoneal cancer index, completeness of cytoreduction (CC) score and intraoperative ascites. Multivariate analysis identified 3 independent factors associated with PS: preoperative CA 125 level, vascular tumor embolus, and CC score. Survival analysis demonstrated that MPM patients with PS had worse prognosis, although PS was not an independent prognostic factor. CONCLUSIONS: PS is not rare in patients with MPM, and is independently associated with preoperative CA 125 level, vascular tumor embolus and CC score. PS often indicates advanced disease and poor prognosis.

Temporal Distribution Patterns of Cryptic Brachionus calyciflorus (Rotifera) Species in Relation to Biogeographical Gradient Associated with Latitude.

Sympatric distribution and temporal overlap of cryptic zooplankton species pose a challenge to the framework of the niche differentiation theory and the mechanisms allowing competitor coexistence. We applied the methods of phylogenetic analysis, DNA taxonomy, and statistical analysis to study the temporal distribution patterns of the cryptic B. calyciflorus species, an excellent model, in three lakes, and to explore the putative mechanisms for their seasonal succession and temporal overlap. The results showed that in the warm-temperate Lake Yunlong, B. fernandoi and B. calyciflorus s.s. underwent a seasonal succession, which was largely attributed to their differential adaptation to water temperature. In the subtropical Lake Jinghu, B. fernandoi, B. calyciflorus s.s., and B. dorcas exhibited both seasonal succession and temporal overlap. Seasonal successions were largely attributed to their differential adaptation to temperature, and temporal overlap resulted from their differential responses to algal food concentration. In the tropical Lake Jinniu, B. calyciflorus s.s. persisted throughout the year and overlapped with B. dorcas for 5 months. The temporal overlap resulted from their differential responses to copepod predation. These results indicated that the temporal distribution pattern of the cryptic B. calyciforus species and the mechanism that allows competitor coexistence vary with different climate zones.

Facile fabrication of carbon nanotube hollow microspheres as a fiber coating for ultrasensitive solid-phase microextraction of phthalic acid esters in tea beverages.

The efficient extraction of phthalic acid esters (PAEs) is challenging due to their extremely low concentration, complicated matrices and hydrophilicity. Herein, hollow microspheres, as an ideal coating, possess significant potential for solid-phase microextraction (SPME) due to their fascinating properties. In this study, multiwalled carbon nanotube hollow microspheres (MWCNT-HMs) were utilized as a fiber coating for the SPME of PAEs from tea beverages. MWCNT-HMs were obtained by dissolving the polystyrene (PS) cores with organic solvents. Interestingly, MWCNT-HMs well maintain the morphology of the MWCNTs@PS precursors. The layer-by-layer (LBL) assembly of MWCNTs on PS microsphere templates was achieved through electrostatic interactions. Six PAEs, di-ethyl phthalate (DEP), di-iso-butyl phthalate (DIBP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP) and di-n-octyl phthalate (DOP), were selected as target analytes for assessing the efficiency of the coating for SPME. The stirring rate, sample solution pH and extraction time were optimized by using the Box-Behnken design. Under optimal working conditions, the proposed MWCNT-HMs/SPME was coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS) to achieve high enrichment factors (118-2137), wide linearity (0.0004-10 µg L-1), low limits of detection (0.00011-0.0026 µg L-1) and acceptable recovery (80.2-108.5%) for the detection of PAEs. Therefore, the MWCNT-HM coated fibers are promising alternatives in the SPME method for the sensitive detection of PAEs at trace levels in tea beverages.