Cities Of Fujian Province Research Articles

A prediction nomogram for postoperative gastroparesis syndrome in right colon cancer: a retrospective study.

To investigate the high-risk factors for postoperative gastroparesis syndrome (PGS) in right colon cancer and to build a prediction nomogram for personalized prediction of PGS. Our study retrospectively analyzed 361 patients with right colon cancer who underwent right hemicolectomy at The First Hospital of Putian City in Fujian Province, China and who were hospitalized between January 2012 and July 2022. Multivariate logistic regression was used to determine the independent risk factors for PGS and to establish a nomogram model. Furthermore, discrimination, calibration, and clinical benefits were used to evaluate the model. The multivariate logistic regression revealed that dissection of the subpyloric lymph nodes (No. 206 lymph node) (OR 5.242, P = 0.005), preoperative fasting blood glucose level (OR 3.708, P = 0.024), preoperative albumin level (OR 3.503, P = 0.020), and total operative time (OR 4.648, P = 0.014) were independent risk factors for PGS. Based on the above four factors, the area under the ROC curve (AUC) and C-index of the nomogram were 0.831. The prediction nomogram's calibration curve was closer to the ideal diagonal, and the Hosmer‒Lemeshow test indicated that the nomogram fit well (P = 0.399). Moreover, the decision curve analysis revealed that the model can present better clinical benefits when the threshold probability was between 1 and 28%, and the internal validation verified the dependability of the model (C-index = 0.948). A risk prediction nomogram based on perioperative factors provided the physician with a simple, visual, and efficient tool for the prediction and management of PGS in right colon cancer.

Short-term and long-term effects of Sanming healthcare system reform on drug-related expenditures for rural patients with cancer in public hospitals: an interrupted time series analysis using segmented regression model in China

ObjectivesTo assess the effects of ‘Sanming model’ on drug-related expenditures.DesignInterrupted time series analysis with two time points was conducted to analyse the effects of ‘Sanming model’ using segmented regression model.SettingTwo...

The Structural Features and Centrality Optimization of a Firm Interlocking Network of the Nodal Cities on the South Route of the 21st-Century Maritime Silk Road: The Case of Fujian Province

The 21st-Century Maritime Silk Road is an important part of the “Belt and Road Initiative”. It is intended to carry out broader and deeper regional cooperation and to provide a Chinese solution for reforming the world economic governance model. Fujian Province, as the starting point of the historical Maritime Silk Road, its development status, and the development strategy is of vital importance for the 21st-Century Maritime Silk Road’s sustainable and balanced regional development. Based on the data on the spatial distribution of the headquarters and branches of enterprises in information-related industries, this study, from the perspective of enterprise connection, constructed a firm interlocking network along the south route of the 21st-Century Maritime Silk Road covering nodal cities along the southeast coast of China and cities in Southeast Asian countries. In addition, this paper analyzed the structural features of the firm interlocking network in the region from the perspectives of centrality and connectivity and considered the goal of constructing the core area of the 21st-Century Maritime Silk Road to extract the influencing factors of the firm interlocking network. The core factors influencing the centrality of cities were analyzed and identified by taking Fujian Province as an example. The study found that cities in Fujian Province generally have problems such as unremarkable centrality and weak connectivity in the firm interlocking network in the region and that the three dimensions of policy coordination, financial integration, and technology exchange in the three cities of Fujian Province need to be strengthened despite the achievements made in the three dimensions of facility connectivity, unimpeded trade, and closer people-to-people bonds. Policy suggestions for promoting the centrality of nodal cities in Fujian Province and accelerating the integration into regional city networks were made based on the above research findings and Fujian Province’s development goal of constructing a core area of the 21st-Century Maritime Silk Road.

Validation of the sleep disturbance scale for children (SDSC) in infants and toddlers from mainland China.

This study is to evaluate the reliability and validity of SDSC among infants (aged 6-36 months), and to provide a reference for expanding the application of the SDSC for Chinese infants (SDSC-I). From April to November 2021, parents of infants from Fuzhou, Quanzhou, Longyan, Sanming, and Nanping cities in Fujian Province, China completed the SDSC-I. Several factor analyses were performed to evaluate the reliability and validity of the scale. Of note, 432 out of 469 samples were valid. After item selections and exploratory factor analyses, the SDSC-I concluded six dimensions (disorders of initiating sleep, disorders of maintaining sleep, sleep hyperhidrosis, sleep breathing disorders, parasomnias, and non-restorative sleep and excessive somnolence) with 23 items. The Cronbach's α coefficient of the scale was 0.863, and those for the six dimensions were within 0.576-0.835. The values of parameters for content validity of the scale were: IR = 0.87, I-CVI > 0.78, Kappa value > 0.74, S-CVI/UA = 0.87, S-CVI/Ave = 0.98. Principal component analysis revealed that the Kaiser-Meyer-Olkin (KMO) value was 0.84, and the factor loading of items ranged from 0.328 to 0.849, with six factors of eigenvalue more than one, which could explain 58.274% of the total variance. The confirmatory factor analysis results showed that χ2/DF was 3.556, root-mean-square error of approximation (RMSEA) was 0.077, comparative fit index (CFI) was 0.809, and standardized RMR (SRMR) was 0.070. Our study provides evidence that the SDSC-I is reliable and valid, and it is effective for the screening and management of sleep disturbances among infants (aged 6-36 months). Compared with other questionnaires such as the Brief Infant Sleep Questionnaire (BISQ), it is worthy of popularization and application in pediatric primary care.

Research on landscape reproduction of ancient city historic blocks

Abstract Ancient city is an important carrier of urban historical landscape development, with the development of urbanization, the protection and development of ancient city landscape has become a hot topic. Taking Taierzhuang ancient city in Shandong province and Quanzhou ancient city in Fujian province as investigated examples. This paper discusses the different characteristics and problems of the derivation landscape reproduction and “airborne” landscape reproduction. It further discusses the necessity of historical landscape reproduction and the complexity of landscape reproduction.

Comprehensive genome sequence analysis of the devastating tobacco bacterial phytopathogen Ralstonia solanacearum strain FJ1003.

Due to its high genetic diversity and broad host range, Ralstonia solanacearum, the causative phytopathogen of the bacterial wilt (BW) disease, is considered a “species complex”. The R. solanacearum strain FJ1003 belonged to phylotype I, and was isolated from the Fuzhou City in Fujian Province of China. The pathogen show host specificity and infects tobacco, especially in the tropical and subtropical regions. To elucidate the pathogenic mechanisms of FJ1003 infecting tobacco, a complete genome sequencing of FJ1003 using single-molecule real-time (SMRT) sequencing technology was performed. The full genome size of FJ1003 was 5.90 Mb (GC%, 67%), containing the chromosome (3.7 Mb), megaplasmid (2.0 Mb), and small plasmid (0.2 Mb). A total of 5133 coding genes (3446 and 1687 genes for chromosome and megaplasmid, respectively) were predicted. A comparative genomic analysis with other strains having the same and different hosts showed that the FJ1003 strain had 90 specific genes, possibly related to the host range of R. solanacearum. Horizontal gene transfer (HGT) was widespread in the genome. A type Ⅲ effector protein (Rs_T3E_Hyp14) was present on both the prophage and genetic island (GI), suggesting that this gene might have been acquired from other bacteria via HGT. The Rs_T3E_Hyp14 was proved to be a virulence factor in the pathogenic process of R. solanacearum through gene knockout strategy, which affects the pathogenicity and colonization ability of R. solanacearum in the host. Therefore, this study will improve our understanding of the virulence of R. solanacearum and provide a theoretical basis for tobacco disease resistance breeding.

Visual acuity of urban and rural adults in a coastal province of southern China: the Fujian Eye Study.

To evaluate the vision status and sociodemographic associations of visual acuity (VA) in an urban and rural population in a coastal province of southern China. The Fujian Eye Study, a population-based cross-sectional study, was performed from May 2018 to October 2019. Totally 10 044 participants over 50 years old from all nine cities in Fujian Province were enrolled, and underwent a questionnaire and a series of standard physical and ocular examinations. VA was measured by E Standard Logarithmic Visual Acuity Chart (GB 11533-1989). Data was double entered with EpiData v3.1 for data collation and Stata/SE statistical software v15.1 was used to analyze the data. Totally 8211 (81.8%) participants were finally included and were divided into urban populations (4678 subjects), rural populations (n=3533), coastal residents (n=6434), and inland residents (1777 subjects); 4836 participants were female. The mean age was 64.39±8.87y (median 64y; range 50-98y). The mean presenting VA was 0.61±0.30 (0.23±0.27 logMAR), and the mean best corrected visual acuity (BCVA) was 0.82±0.28 (0.08±0.19 logMAR). In the multiple regression analysis, BCVA was significantly correlated with several socioeconomic and biologic factors, including age (P<0.001), education level (P<0.001), income (P=0.005), rural residency (P<0.001), inland residency (P=0.001) and refractive error (P<0.001), while sex (P=0.194) was independent with BCVA. Accessible services and eye health policies targeting the elderly, people with high myopia and people living in rural or inland areas are needed.

An Evaluation Model of Talent Attraction in Fujian Province Based on Principal Component Analysis

Today's economic development is focused on abilities, and the rivalry for talents is becoming increasingly evident. This paper identifies fifteen key influencing indicators of talent attraction of nine cities in Fujian Province. The principal component analysis (PCA) approach is then utilized to examine the talent attractiveness of nine cities in Fujian Province in depth. The results show that the ranking of talent attractiveness of nine cities in Fujian Province is as follows: Xiamen, Fuzhou, Putian, Quanzhou, Ningde, Sanming, Longyan, Zhangzhou, and Nanping. It shows that the cities with higher economy are more attractive to talents. Talents have the potential to propel the economy forward. On the contrary, the growth of the economy will draw an influx of talent.

Study on Sustainable Development Strategy of Subway in Medium-sized Cities in China: Case Study of Fujian Cities

The development of the subway is closely related to the urban economy in China, and it is also a sign of the development of urban modernization. With sustainable transportation development becoming a global issue, the construction of medium-sized urban subways is limited by the economic volume and is often in the trade-off between construction speed and financial burden. This paper takes the subway cities of Fujian Province -Fuzhou and Xiamen as the research object and analyzes the relative positions of the metros of the two metropolitan areas in 38 metro cities in China. The result of linear regression analysis shows that Fuzhou's progress is slightly conservative, while Xiamen is slightly ahead. There is still space for improvement in the carrying intensity of the subways in the two cities. Comparing the relationship between subway construction and economic growth in medium-sized cities, there is still obvious room for development in subway construction in the two cities. During the research process, actual investigations were conducted to formulate corresponding improvement strategies and suggestions for the operation problems of the two cities for reference by the urban management departments.

RETRACTED: Research on Rural Revitalization and Governance From the Perspective of Sustainable Development

The Chinese government has long attached great importance to rural revitalization. The harmony and stability in rural areas are the fundamental guarantees of rural sustainable economic growth and farmers’ prosperity, and they rely on effective rural governance. Taking the Fu’an City in Fujian Province of China as an example, this paper analyzes the rural governance problems arising from the implementation of the rural revitalization strategy with the method of dynamic games with incomplete information after data collection by on-the-spot investigation and file inquiry, etc. The results show that the “solicitation” behavior of village B to increase its own income does not maximize the income of village B and village N; Even under the optimal state of income distribution is derived through the game model, the income distribution between the two villages is still unfair to village N, the investor of the “Waterlands Resort”. Therefore, in order to solve the rural governance problems caused by the distribution of benefits between village B and village N, government subsidies, property rights protection, village rules and regulations are required. Besides, the leading role of rural grassroots organizations should be given full play, and villagers’ self-governing system needs to be improved.

Spatiotemporal patterns and ozone sensitivity of gaseous carbonyls at eleven urban sites in southeastern China

Gaseous carbonyls are essential trace gases for tropospheric chemistry and contribute significantly to the formation of ambient air ozone (O3) in densely populated regions, especially in China. Pollution characterization and the analysis of O3, nitrogen oxides, and volatile organic compounds (O3-NOX-VOCs) sensitivities of carbonyls were investigated from October 22 to 28, 2018 at eleven urban sites in nine cities in Fujian Province, southeastern China. The total mixing ratios of 15 kinds of gaseous carbonyls (Σ15OVOCs) was 12.15 ± 2.53 ppbv in Fujian Province. The concentrations in the eastern coastal regions were higher than those in the western mountainous regions. Formaldehyde, acetone, and acetaldehyde were the top three species of Σ15OVOCs concentration. Photochemical formation during the daytime and vehicle emission during the rush hours significantly contributed to formaldehyde and acetaldehyde. The shoe-making industry is well developed in Putian, where the acetone mixing ratio was significantly higher than in other cities. The O3-NOX-VOCs sensitivities at all urban sites were in VOC-limited or transitional regimes based on the ratios of formaldehyde to NO2; from morning to afternoon, the VOC-limited sensitivity decreased, and the NOX-limited sensitivity increased gradually. Formaldehyde contributed the most significant O3 formation potential (OFP) proportion of the Σ15OVOCs. The OFP of carbonyl species accounted for half of the total VOCs in Fuzhou and Putian, suggesting that more attention needs to be given to gaseous carbonyls control. Overall, the links inferred by this study provide evidence and clues to mitigate the increasing ambient O3 concentration on the west coast of the Taiwan Strait.

Accounting of gross ecosystem product in Fuzhou City,China.

Carrying out the accounting of ecological system gross ecosystem product (GEP) is a necessary measure to promote the construction of ecological civilization system and an important measure for the integration of ecological benefits into the economic and social development evaluation system. Taking Fuzhou City as the object, we constructed an ecosystem value accounting system with the characteristics of "mountain, sea, and city" to calculate the GEP of Fuzhou City in 2015 and 2018, and compared them from the perspective of temporal and spatial changes. The results showed that the GEP of Fuzhou in 2015 and 2018 was 920.592 and 1047.242 billion yuan, respectively. The per capita GEP in 2015 and 2018 was 130200 and 143900 yuan, the supply service value of ecological products was 94.181 and 110.261 billion yuan, the value of ecological regulation was 636.42 and 598.851 billion yuan, and the service value of ecological culture was 189.991 and 338.13 billion yuan, respectively. Compared with that in 2015, the GEP of Fuzhou City in 2018 increased by 126.65 billion yuan, with an increase of 13.8%, which was mainly due to the increases in ecological product supply service and cultural service. The value of ecological regulation services decreased by 37.569 billion yuan, with a reduction of 5.9%, which was mainly due to the decreases in climate regulation, water flow regulation and water purification services. Fuzhou City took the lead in exploring the establishment of accounting system with the characteristics of "mountain, sea, and city", which could provide a "Fuzhou model" for the accounting work of other cities in Fujian Province and other regions in China, and promote the establishment of a long-term mechanism for realizing the value of ecological products.

First Report of Anthracnose on Hymenocallis littoralis Caused by Colletotrichum siamense in China.

Spider lily (Hymenocallis littoralis (Jacq.) Salisb.) is a widely cultivated horticultural plant worldwide and has ornamental and medicinal value. Spider lily plants were seriously affected by a leaf spot disease in the campus of Guangdong Ocean University and gardens in Zhanjiang city in February 2018 with an incidence of 30 to 100%. Affected leaves usually developed small circular purple spots, which enlarged to oval spots and large irregular spots. The spots were brown at the center, deep purple at the border and surrounded by a yellow halo. Diseased cultivars were collected in Zhanjiang city, Gangzhou city in Guangdong province and and Zhangping city in Fujian province. Symptomatic leaf samples were disinfested with 1% NaOCl, and cultured on sucrose agar (PSA) at 28 °C for one week. Ten single-spore isolates were recovered from PSA medium. Colonies developing on PSA were grayish white with a regular border. Conidia were straight, hyaline with rounded ends, 4.3 to 6.1×12.8 to 32.1μm (n = 50 conidia of each isolate). Fungal mycelia were hyaline, septate, and branched. Conidia were born on a long conidiogenous cell, appressoria were oval, 6.7 to 10.7 × 5.2 to 6.2 μm (n=50). The isolates were morphologically identified as Colletotrichum sp. (Weir et al. 2012). Tests of pathogenicity were performed according to Koch's postulates using three isolates. Fresh wounds were made with a sterile needle on the healthy surface of leaves of H. littoralis at the 4- to 6-leaf stage and each leaf was covered with a piece of cotton drenched with 200 μL of conidial suspension (106 conidia/ml) from each isolate. Control seedlings were inoculated identically except sterile water was used to drench the cotton. Inoculated plants were placed in a moisturizing light incubator at 25℃ and 80% humidity under a 12-h light/dark cycle for 20 days and examined daily to monitor disease symptom development. Small round brown spots were observed at the inoculation sites 3 days after the inoculation. The brown spots developed into large brown lesions 5 days after inoculation. There were no symptoms observed in the water-inoculated plants. A Colletotrichum spp. strain based on morphology was consistently reisolated from leaves lesions fulfilling Koch's postulates. For molecular identification, the internal transcribed spacer (ITS) region of ribosomal DNA, calmodulin (CAL), Tublin (Tub) and Apmat loci of three isolates were amplified using primer pairs of ITS4/ITS5, CL1C/CL2C, T1/T2 and AM-F/AM-R (Sharma et al. 2015). A phylogenetic tree derived from a neighbor-joining analysis of a concatenated alignment of ITS, CAL, Tub and ApMAT sequences was created. The accession numbers of three isolates GZHLCG, ZJHLCG and FJHLCG used in this study were MW553083, MN540457, MN540458 for ITS, MW553087- MW553089 for CL, MW553090-MW553092 for Tub and MW553084-MW553086 for ApMAT. The sequences of the three isolates were aligned with related species of Colletotrichum (Sharma et al. 2015). Analyses based on concatenated data sets of four genes showed that the sequences had high levels of identity to those of the C. siamense strains. According to both morphological and sequence analyses, the H. littoralis pathogen was identified as C. siamense. There is a report of foliar diseases on H. littoralis caused by Colletotrichum sp. (Tan et al., 2009). To our knowledge, this is the first report of anthracnose on H. littoralis caused by C. siamense in China. Identification of the pathogen provide valuable information for diagnosis and controlling this disease in H. littoralis.

Spatiotemporal Differentiation of Coupling and Coordination Relationship of the Tea Industry–Tourism–Ecological Environment System in Fujian Province, China

Correctly understanding and handling the relationships in the tea industry–tourism–ecological environment system is a prerequisite and foundation for the high-quality and sustainable development of the tea tourism industry. In this study, an evaluation index system of the tea industry–tourism–ecological environment system is established, the weight coefficient of each indicator is determined by the entropy weight method, and the coupling coordination degrees of Fujian Province and nine cities therein are evaluated by constructing a coupling coordination model from 2011 to 2019. The results indicate that the comprehensive development index of the tea industry–tourism–ecological environment system had an overall upward trend from 2011 to 2019, and the coupling coordination degree of the three systems changed from moderate maladjustment to high-quality coordination. There was spatial heterogeneity in the comprehensive development indices and coupling coordination degrees of the three systems, when considering the nine cities of Fujian Province. This study offers both theoretical and practical implications for further improving the development level and overall coordination between the tea industry, tourism, and the ecological environment in Fujian province.

Measurement and Analysis of Ecological Efficiency in Fujian Province Based on DEA-Malmquist Index Model

Under the new normal, the economic growth model of resource and environment consumption is unsustainable, and improving ecological efficiency has become an inevitable choice for high-quality economic development. Based on this, on the basis of constructing the input-output evaluation system of ecological efficiency at the city scale, this study uses DEA-Malmquist model to calculate the ecological efficiency and its dynamics of 9 cities in Fujian Province from 2009 to 2018. The results show that there are differences in ecological efficiency among different regions in Fujian Province, and the ecological efficiency of Fuzhou, Xiamen and Ningde all reach the best level. The ecological efficiency of inland areas in Fujian Province is obviously lower than that of coastal areas such as Fuzhou and Xiamen, which indicates that the coordination between inland areas and coastal areas should be strengthened. In addition, the coordination degree of regional production management and technological progress in Fujian Province is not high. Therefore, when the governments at all levels of Fujian Province plan the industrial development strategy, they should fully consider the development path suitable for improving the ecological efficiency, and finally realize the development strategy that green water and green mountains are the golden mountains and silver mountains.

Analysis of the Impact of High-speed Railway on the Upgrade of Consumption Structure

In 2008, with the opening of the Beijing-Tianjin High-speed Railway, China entered an era of rapid development of high-speed railways. The operation of high-speed railways in the past decade has had many effects on the economic development of the surrounding areas. In this paper, the panel data of 9 prefecture-level cities in Fujian Province from 2008 to 2018, the first high-speed railway in China to achieve "city-city connectivity", are analyzed by regression analysis. The results verify that the operation of the highspeed rail has a significant positive effect on the upgrade of the local consumption structure and the actual per capita disposable income and actual per capita GDP that affect residents' consumption.

Using a combined evaluation method to assess water resources sustainable utilization in Fujian Province, China

In order to evaluate the spatial differences in water resources sustainable utilization (WRSU), it is vital to adopt a reasonable evaluation method. However, previous studies mostly used a single evaluation method, resulting in differences in evaluation results. In this paper, the Driving–Pressure–State–Impact–Response (DPSIR) model is used for establishing the indicators system for regional WRSU assessment. The improved rank correlation (IRC) model, fuzzy matter element (FME) analysis, grey relational analysis (GRA) model, and attribute recognition (AR) model are used to evaluate WRSU. Then, the fuzzy analytic hierarchy process (FAHP) and set pair analysis (SPA) are applie to establish a combined model to evaluate the WRSU status in nine districts and cities in Fujian Province. The research indicates that (1) it is feasible to apply the combined model framework to evaluate the WRSU, and (2) the spatial distribution pattern of WRSU in Fujian Province shows a decreasing trend from northwest to southeast. Additionally, the water resources endowment, population density and socioeconomic development have become the main factors restricting the WRSU. The assessment results are fundamentally conformed to the actual situation of Fujian. It provides significant for sustainable development of water resources in Fujian.

MONITORING AND ASSESSMENT OF ECOLOGICAL CHANGE IN COASTAL CITIES BASED ON RSEI

Abstract. With the speeding up of urbanization process, ecological problems, such as unsustainable land use and environmental pollution,have emerged one after another in cites. Nowadays, green development and ecological priority are the important concepts and trends of the current new urban planning in China. In this study, Pingtan County, a coastal city in Fujian Province, China, was taken as the research area. Based on two Landsat 8 remote sensing images (2016, 2017), and two Sentinel-2A remote sensing images (2016, 2017), we first adopt the modified normalized water body index (MNDWI) to mask the water body. Four indicators, including greenness, humidity, dryness and heat were extracted to synthesize the remote sensing ecological index (RSEI), which were obtained by principal component analysis method. Based on the RSEI values acquired from Landsat 8 and Sentinel-2A images, the ecological environment change trend in Pingtan County was evaluated .The experimental results show that: 1) The RSEI indicators based on Landsat 8 and sentinel data all show a downward trend, but due to due to the influence of image spatial resolution and PCA weighting coefficient, the RSEI index has different degrees of decline. 2) The main reason for the decline in RSEI is the increase in NDSI indicators. Compared with July 2016, the bare ground increased in April 2017. Although the NDVI has increased, the overall trend is still declining. Therefore, it is necessary to ecologically return farmland and improve vegetation coverage in the future development process. 3) In recent years, the ecological quality of new construction land near drinking water sources has declined, so it is necessary to strengthen monitoring of changes in the region.

Fatty acid ester metabolites of gymnodimine in shellfish collected from China and in mussels (Mytilus galloprovincialis) exposed to Karenia selliformis

Marine shellfish exposed to the microalgae Karenia selliformis can accumulate gymnodimines (GYM). Shellfish samples collected from Beihai City in Guangxi Autonomous Region, and Ningde City in Fujian Province, in the South China Sea, as well as mussels Mytilus galloprovincialis fed on K. selliformis under laboratory conditions were analyzed. Gymnodimines and various fatty acid ester metabolites were detected in the clam Antigona lamellaris and pen shell Atrina pectinata, while no esters were found in the oyster Crassostrea sp. and the gastropod Batillaria zonalis despite positive detection of free GYM in both species. When present, the predominant acyl esters observed were 18:0-GYM-A and 20:1-GYM-A. Under laboratory conditions GYM-A was accumulated and metabolized to fatty acid esters in mussels exposed to K. selliformis, with 16:0-GYM-A and 20:1-GYM-A as the major variants. A novel compound with the same accurate mass as GYM-A and its 16:0 fatty acid ester were observed in the experimental mussels but was not present in the microalgal strain to which mussels were exposed. No significant differences of reactive oxygen species (ROS) levels and antioxidant enzymes were found between mussels fed on K. selliformis or GYM-free microalgae Isochrysis galbana. This suggests the accumulation of GYM and its metabolites does not significantly impact the physiological status of mussels. While it is currently not proven that GYM affects human health, risk assessments should consider the presence of GYM esters in naturally contaminated shellfish as part of exposure analysis.

Metal–organic framework-derived nitrogen-doped carbon nanotube cages as efficient adsorbents for solid-phase microextraction of polychlorinated biphenyls

An efficient and stable adsorbent is of critical importance for solid-phase microextraction (SPME). In this study, we prepared metal–organic framework-derived nitrogen (N)-doped carbon (C) nanotube cages (N-CNTCs) with unique N-doped active sites and C-rich nanotubes to coat SPME adsorbents. This new material was obtained via a simple thermal treatment with ZIF-67, and exhibited high porosity and excellent chemical and thermal stability. Compared with commercial fibers and traditional C nanotubes-coated fiber (15 nm), N-CNTC-coated fiber exhibited better extraction properties, mainly due to its π–π interactions, abundant active sites, and hollow cage structure, which is composed of interconnected crystalline N-doped C nanotubes. N-CNTC-coated fiber exhibited better extraction performance and shorter extraction equilibrium time than the solid N-doped C-coated fiber due to its hollow cage structure. The N-CNTC-coated fiber was then used to identify polychlorinated biphenyls (PCBs) with wide linear range (0.3–1000.0 ng L−1), low limits of detection (0.10–0.22 ng L−1), good repeatability (intra-day, 2.6–3.8%; inter-day, 3.3–4.8%), and good reproducibility (<8.6%). We then successfully applied the N-CNTC-coated fiber to detect PCBs in river water samples from six cities in Fujian Province and obtained satisfactory recovery levels. Thus, the novel N-CNTCs coating proposed in this study is a promising candidate for SPME coating.