Constructing 2D Polyphenols-Based Crosslinked Networks for Ultrafast and Selective Uranium Extraction from Seawater.

The role of tannins (TA), a well-known abundant and ecologically friendly chelating ligand, in metal capture has long been studied. Different kinds of TA-containing adsorbents are synthesized for uranium capture, while most adsorbents suffer from unfavorable adsorption kinetics. Herein, the design and preparation of a TA-containing 2D crosslinked network adsorbent (TANP) is reported. The ≈1.8-nanometer-thick TANP films curl up into micrometer-scale pores, which contribute to fast mass transfer and full exposure of active sites. The coordination environment of uranyl (UO2 2+) ions is explored by integrated analysis of U L3-edge XANES and EXAFS. Density functional theory calculations indicate the energetically favorable UO2 2+ binding. Consequently, TANP with excellent adsorption kinetics presents a high uranium capture capacity (14.62 mg-U g-Ads-1) and a high adsorption rate (0.97 mg g-1 day-1) together with excellent selectivity and biofouling resistance. Life cycle assessment and cost analysis demonstrate that TANP has tremendous potential for application in industrial-scale uranium extraction from seawater.

Impact of social-psychological factors on low-carbon travel intention: Merging theory of planned behavior and value-belief-norm theory.

Low-carbon travel assumes paramount significance in energy conservation and the establishment of an eco-friendly transportation ecosystem. This paper endeavors to explore the relationship between low-carbon travel intention, latent psychological variables, and sociodemographic attributes, drawing insights from responses of 602 residents in Hangzhou, China by structural equation model and multi-group model. In particular, we synthesize the theory of planned behavior, value-belief-norm theory, and view of incentive, a reflection of the public support for incentive policies. Results reveals that the primary determinants influencing the low-carbon travel intention encompass the view of incentive, attitude, and subjective norms. Individuals with diverse sociodemographic attributes manifest varying sensitivities, with males and elders exhibiting heightened responsiveness to incentive, while the presence of children decrease the attraction of incentive. These findings demonstrate that low-carbon travel intention can be increased by three ways, one is by the strong attraction of incentive especially tailor incentive policy, another is by making family-friendly policies to facilitate travel for groups with children, and the last is by improving the quality of low-carbon travel services thus increasing the attitude and other determinants.

Three-dimensional measurement and analysis of Mandibular Molar Distalization assisted by micro-implant anchorage combined with clear aligner.

Objective: To investigate the effect of micro-implant anchorage combined with a clear aligner on the efficiency of mandibular molar distalization and the protection of anterior teeth anchorage, provide reference for clinical scheme design. Methods: This is a prospective study. Seventeen patients who were treated in the Orthodontics Department of the Hospital of Stomatology affiliated to Fujian Medical University from 2019 to 2021 and used Invisalign clear aligners to move mandibular molars distally were included and divided into two groups according to anchorage types: Group-A and Group-B. Group-A (ten cases) were treated without micro-implant anchorage, while Group-B (seven cases) were treated with micro-implant anchorage nails for enhanced anchorage. The effect of micro-implant anchorage on crown and root distal movement of mandibular molars and the difference in three-dimensional movement between mandibular molars and mandibular central incisors were analyzed. Results: The crown distalization efficiency of mandibular first and second molars in Group-B was 68.66% and 71.02%, respectively, which were higher than those in Group-A(p<0.05). The mandibular central incisors in Group-A showed labial displacement and a small amount of elongation, while those in Group-B showed less anchorage loss(p<0.05). In Group-A, the crown was tilted in the distal direction and moved in the buccal direction during mandibular molar distalization(p<0.05). While in Group-B, the crown was tilted in the distal directio (p<0.05) and the mandibular second molar was depressed(p<0.05). Conclusion: In the process of mandibular molar distalization assisted by micro-implant anchorage combined with a clear aligner, better protects the anchorage of the mandibular central incisor and improves the efficiency of the molar crown distalization.

Perception of strigolactones and the coordinated phytohormonal regulation on rice (Oryza sativa) tillering is affected by endogenous ascorbic acid.

Phytohormones play a key role in regulating tiller number. Ascorbic acid (Asc)-phytohormone interaction plays a pivotal role in the regulation of senescence. We analysed the relationship between Asc and the enzyme concentrations and gene transcript abundances related to the signal perception of strigolactones (SLs), the contents of four phytohormones (abscisic acid, ABA; jasmonic acid, JA; indole acetic acid, IAA; cytokinin, CTK), the enzyme concentrations and gene transcript abundances related to the synthesis or transportation of these four phytohormones. Our results showed that Asc deficiency leads to the upregulation of enzyme concentrations, gene transcript abundances related to the SL signal perception, ABA synthesis and IAA transport. The altered level of Asc also leads to a change in the contents of ABA, JA, IAA and CTK. These findings support the conclusion that Asc or Asc/DHA play an important role in the signal perception and transduction of SLs, and Asc may affect the coordinated regulation of SL, IAA and CTK on rice (Oryza sativa ) tillering.

Nrf3 alleviates oxidative stress and promotes the survival of colon cancer cells by activating AKT/BCL-2 signal pathway.

Oxidative stress is closely linked to tumor initiation and development, conferring a survival advantage to cancer cells. Therefore, understanding cancer cells' antioxidant molecular mechanisms is crucial to cancer therapy. In this study, we discovered that H2O2-induced oxidative stress increased Nrf3 expression in colon cancer cells. Overexpression of Nrf3 decreased H2O2-mediated cytotoxicity and apoptosis. Furthermore, Nrf3 reduced reactive oxygen species levels and malondialdehyde concentrations after H2O2 treatment. Mechanistically, H2O2-mediated cell apoptosis involves multiple signaling proteins, including Akt, bcl-2, JNK, and p38. An increase in Nrf3 expression in colon cancer cells treated with H2O2 partly reversed Akt/Bcl-2 inhibition, whereas it decreased activation of p38 and JNK. In addition, we found that increasing Nrf3 decreased stress-associated chemical-induced cell death, resulting in drug resistance. According to these results, Nrf3 is critical for drug resistance and oxidant adaptation.

Significant perioperative parameters affecting postoperative complications within 30 days following craniotomy for primary malignant brain tumors.

BACKGROUND: The occurrence of postoperative complications within 30 days (PC1M) of a craniotomy for the removal of a primary malignant brain tumor has been associated with a poor prognosis. However, it is still unclear to early predict the occurrence of PC1M. This study aimed to identify the potential perioperative predictors of PC1M from its preoperative, intraoperative, and 24-h postoperative parameters. METHODS: Patients who had undergone craniotomy for primary malignant brain tumor (World Health Organization grades III and IV) from January 2011 to December 2020 were enrolled from a databank of Kaohsiung Veterans General Hospital, Taiwan. The patients were classified into PC1M and nonPC1M groups. PC1M was defined according to the classification by Landriel et al. as any deviation from an uneventful 30-day postoperative course. In both groups, data regarding the baseline characteristics and perioperative parameters of the patients, including a new marker-kinetic estimated glomerular filtration rate, were collected. Logistic regression was used to analyze the predictability of the perioperative parameters. RESULTS: The PC1M group included 41 of 95 patients. An American Society of Anesthesiologists score of > 2 (aOR, 3.17; 95% confidence interval [CI], 1.19-8.45; p = 0.021), longer anesthesia duration (aOR, 1.16; 95% CI, 0.69-0.88; p < 0.001), 24-h postoperative change in hematocrit by > - 4.8% (aOR, 3.45; 95% CI, 1.22-9.73; p = 0.0019), and 24-h postoperative change in kinetic estimated glomerular filtration rate of < 0 mL/min (aOR, 3.99; 95% CI, 1.52-10.53; p = 0.005) were identified as independent risk factors for PC1M via stepwise logistic regression analysis. When stratified according to the age of ≥ 65 years (OR, 11.55; 95% CI, 1.30-102.79; p = 0.028), the reduction of kinetic estimated glomerular filtration rate was more robustly associated with a higher risk of PC1M. CONCLUSIONS: Four parameters were demonstrated to significantly influence the risk of PC1M in patients undergoing primary malignant brain tumor removal. Measuring and verifying these markers, especially kinetic estimated glomerular filtration rate, would help early recognition of PC1M risk in clinical care.

Nrf3 promotes the proliferation and migration of triple­negative breast cancer by activating PI3K/AKT/mTOR and epithelial­mesenchymal transition.

Nuclear factor erythroid 2-related factor 3 (Nrf3) is increasingly implicated in multiple types of cancer; however, its function in triple-negative breast cancer (TNBC) remains unclear. This study aimed to examine the role of Nrf3 in TNBC. Compared with adjacent normal tissues, TNBC tissues expressed higher levels of Nrf3, and its expression was negatively correlated with survival time. Additionally, Nrf3 knockdown reduced the proliferation and migration of TNBC cells, whereas overexpression of Nrf3 had the opposite effects in vitro and in vivo. Moreover, functional enrichment of TNBC cells overexpressing Nrf3 allowed for the identification of numerous genes and pathways that were altered following Nrf3 overexpression. Further study showed that overexpression of Nrf3 activated the PI3K/AKT/mTOR signaling pathway and regulated the expression of proteins associated with epithelial-mesenchymal transition. Nrf3 was found to directly bind to p110α promoter regions, as evidenced by luciferase reporter and chromatin immunoprecipitation assays. Furthermore, PI3K inhibitors partially decreased the proliferation and migration of the Nrf3 overexpressing TNBC cells. In conclusion, Nrf3 enhances cellular proliferation and migration by activating PI3K/AKT/mTOR signaling pathways, highlighting a novel therapeutic target for TNBC.

Ligand-Assistant Iced Photocatalytic Reduction to Synthesize Atomically Dispersed Cu Implanted Metal-Organic Frameworks for Photo-Enhanced Uranium Extraction from Seawater.

Uranium extraction from natural seawater is one of the most promising routes to address the shortage of uranium resources. By combination of ligand complexation and photocatalytic reduction, porous framework-based photocatalysts have been widely applied to uranium enrichment. However, their practical applicability is limited by poor photocatalytic activity and low adsorption capacity. Herein, atomically dispersed Cu implanted UiO-66-NH2 (Cu SA@UiO-66-NH2 ) photocatalysts are prepared via ligand-assistant iced photocatalytic reduction route. N-Cu-N moiety acts as an effective electron acceptor to potentially facilitate charge transfer kinetics. By contrast, there exist Cu sub-nanometer clusters by the typical liquid phase photoreduction, resulting in a relatively low photocatalytic activity. Cu SA@UiO-66-NH2 adsorbents exhibit superior antibacterial ability and improved photoreduction conversion of the adsorbed U(VI) to insoluble U(IV), leading to a high uranium sorption capacity of 9.16 mg-U/g-Ads from natural seawater. This study provides new insight for enhancing uranium uptake by designing SA-mediated MOF photocatalysts.

Interfacial passivation of CsPbI3 quantum dots improves the performance of hole-transport-layer-free perovskite photodetectors.

Photodetectors (PDs) suffer from dark current due to defects in the perovskite photosensitive layer. Contact between the photosensitive layer and carbon electrodes could result in recombination of carriers at the interface. In this work, CsPbI3 quantum dots (QDs) were added between the photosensitive layer and the carbon electrode as the interfacial layer to passivate the surface defects of perovskite layer and improve the energy level matching at the interface. The effect of QDs concentrations on the passivation of the perovskite layer was investigated. It was found that the photoluminescence intensity of perovskite films was the strongest and the decay lifetime was the longest when the QDs concentration was 3 mg/mL. Owing to QDs passivation, the dark current of perovskite PD decreased by 94% from [Formula: see text] to [Formula: see text] A. The responsivity (R) at 605 nm improved by 27% from 0.29 to 0.37 A/W at 0 V bias voltage. The specific detectivity (D*) increased by 420% from [Formula: see text] to [Formula: see text] Jones.

Machine learning in the evaluation and prediction models of biochar application: A review.

This article reviews recent studies applying machine learning (ML) approaches to biochar applications. We first briefly introduce the general biochar production process. Various aspects are contained, including the biochar application in the elimination of heavy metals and/or organic compounds and the biochar application in environmental and economic scopes, for instance, food security, energy, and carbon emission. The utilization of ML methods, including ANN, RF, and NN, plays a vital role in evaluating and predicting the efficiency of biochar absorption. It has been proved that ML methods can validly predict the adsorption effectiveness of biochar for water heavy metals with higher accuracy. Moreover, the literature proposed a comprehensive data-driven model to forecast biochar yield and compositions under various biomass input feedstock and different pyrolysis criteria. They said a 12.7% improvement in prediction accuracy compared to the existing literature. However, it might need further optimization in this direction. In summary, this review concludes increasing studies that a well-trained ML method can sufficiently reduce the number of experiment trials and working times associated with higher prediction accuracy. Moreover, further studies on ML applications are needed to optimize the trade-off between biochar yield and its composition.

Identification and Immunomodulatory Effect on Immunosuppressed Mice of Selenium-Enriched Peptides of Egg White.

Selenium-enriched egg white peptides (Se-EWP) were prepared by pre-heat treatment and enzymatic hydrolysis in this study. In addition, their selenopeptide sequence identification and immunomodulatory effect were investigated. Results showed that the yield of Se-EWP obtained from alkaline-neutral protease treatment reached 76.90%, and peptides with a molecular weight of 200-1000 Da accounted for 98.33%. Four characteristic selenopeptides, including SeCys-Trp-Leu-Glu, Trp-Ser-SeCys, SeMet-Ala-Pro, and SeMet-Leu, were identified by HPLC-ESI-MS/MS, which were rich in hydrophobic and branched-chain amino acids. Se-EWP (750 mg/kg/d) could effectively retard the decrease of immune organ index in immunosuppressed mice induced by cyclophosphamide. Moreover, supplementation of Se-EWP could promote a higher content of Se in liver, the number of white blood cells, and the levels of serum cytokines (IL-6, IL-2, and TNF-α) as compared with EWP groups, indicating that Se-EWP could effectively alleviate immunosuppression induced by cyclophosphamide. These findings suggested that Se-EWP exhibited great potential as functional foods for immunomodulatory effect.

Biodegradation and optimization of bilge water in a sequencing batch reactor using response surface methodology.

Bilge water is a significant source of pollution in the marine environment and has captured widespread international attention. In this study, a sequencing batch reactor (SBR) combined with strain S2 identified as Bacillus licheniformis was employed to assess the biodegradation of Chemical Oxygen Demand (COD) from bilge water. The influencing variables such as temperature, pH level and inoculum concentration on the performance SBR system were optimized by utilizing response surface methodology (RSM). The experimental results showed that the maximum COD removal of 77.81% was reached at the optimal SBR operation conditions of temperature 35.44 °C pH 8.13, and inoculum concentration 31.47 mL. In the practical application of SBR, it was found that the decrease in hydraulic retention time (HRT) was accompanied by a decrease in COD degradation rate. The biodegradation kinetics of COD in bilge water were well fitted with the first-order equation with a higher R2 value of 0.98106. In conclusion, COD in bilge water can be efficiently biodegraded by SBR under the optimization of RSM.

User characteristics and service satisfaction of car sharing systems: Evidence from Hangzhou, China.

Car sharing has become a new mode of transport during the past two decades in the world. Its rapid growth in China has attracted a wide range of users and posed some problems. The main focus is on service efficiency and user satisfaction. To explore possible service enhancement and management intervention, this study aims at capturing the user characteristics according to different user types and scrutinizing their satisfaction with station-based one-way car sharing service. The study firstly illustrates descriptive statistics of user profile. This is followed by a study of user satisfaction influenced by user rates on staffs, the efficiency of rental process, vehicle situation, the use of credit card and their familiarity towards rental station. Furthermore, by clustering users according to the total travel time and distance during one rent, two different types of users are identified and defined as User Group A (UGA) and User Group B (UGB). To examine how fully do users utilize the shared cars, ANOVA was conducted implying family car ownership, total travel distance and main travel purpose have strong impact on total rental time for UGB, while for UGA, travel purpose and age have strong impact. Finally, ordinal logistic regression was introduced to find that for UGB, "shopping" is the main travel purpose with longer rental time, whereas for UGA, "out for business", "shopping", "visit friends" or "pick up others" are the main travel purposes with longer total travel time. Based on the findings, advices for operators on how to improve service quality and suggestions for government management strategy are discussed, respectively.

Percutaneous endoscopic gastrostomy can improve survival outcomes in patients with N3 nasopharyngeal carcinoma undergoing concurrent chemoradiotherapy.

OBJECTIVES: Our previous study revealed that percutaneous endoscopic gastrostomy (PEG) and intensive nutritional support may minimize body weight loss, maintain nutritional status, and offer better treatment tolerance for patients with locally advanced nasopharyngeal carcinoma (LA-NPC) during concurrent chemoradiotherapy (CCRT). This study aimed to further explore the potential long-term survival benefits of PEG in LA-NPC. METHODS: Between June 1, 2010 and June 30, 2014, a total of 133 consecutive LA-NPC patients who received prophylactic PEG (pPEG) feeding before the initiation of CCRT were included. Meanwhile, an additional 133 non-PEG patients, who were matched for age; sex; and tumor, node, and metastases stage, were selected as control cohort. The log-rank test was used to compare survival distributions between groups. Multivariate prognosis analysis was conducted using a Cox's proportional hazards regression model. RESULTS: After a median follow-up time of 81 months (range: 4-119 months), pPEG was not associated with significant survival benefits in the whole cohort. However, the N3 NPC patients who underwent PEG had significantly higher 5-year overall survival (OS) and progression-free survival (PFS) (84.0 and 76.0%, respectively) than those who did not undergo PEG (56.7 and 45.6%, respectively; p < 0.05). Univariate and multivariate analyses demonstrated that PEG was an independent factor for N3 survival. CONCLUSION: PEG can maintain the nutritional status and improve the rate of treatment completion for LA-NPC patients who underwent CCRT, and these advantages can transfer into survival benefits in N3 NPC. Further multicenter prospective clinical trials are warranted.

Laser fabricated carbon quantum dots in anti-solvent for highly efficient carbon-based perovskite solar cells.

Additive passivation can be an effective strategy to regulate and control the properties of organic-inorganic halide perovskite film. In this article, carbon quantum dots (CQDs), fabricated by non-focused laser irradiation of carbon nanomaterial diluted in anti-solvent ethyl acetate, denoted as EACQDs, were adopted for perovskite film defect passivation and modification of carbon-based CH3NH3PbI3 perovskite solar cells (PSCs). The size of EACQDs can be tuned by manipulating the laser fluence. The morphology of perovskite film was uncovered through scanning electron microscopy and atomic force microscopy. After embedding of EACQDs, the defect in perovskite crystal was reduced, resulting in the decreased carrier recombination and accelerated carrier transportation, which were demonstrated by electrochemical impedance spectroscopy, photoluminescence and time-resolved photoluminescence. As a consequence, with the optimization of 0.01 mg/mL EACQDs (1064 nm-300 mJ·pulse-1·cm-2-10 min), the power conversion efficiency (PCE) of carbon-based PSCs achieved a maximum value of 16.43%, which improved 23.81% when compared with the pristine PSCs of 13.27%. Furthermore, the EACQDs optimized PSCs also exhibited an excellent stability and still retained 86% of its initial PCE after 50-day storage at the room atmosphere with a humidity of 30-50%.

Effects of CsSnxPb1-xI3 Quantum Dots as Interfacial Layer on Photovoltaic Performance of Carbon-Based Perovskite Solar Cells.

In this work, inorganic tin-doped perovskite quantum dots (PQDs) are incorporated into carbon-based perovskite solar cells (PSCs) to improve their photovoltaic performance. On the one hand, by controlling the content of Sn2+ doping, the energy level of the tin-doped PQDs can be adjusted, to realize optimized band alignment and enhanced separation of photogenerated electron-hole pairs. On the other hand, the incorporation of tin-doped PQDs provided with a relatively high acceptor concentration due to the self-p-type doping effect is able to reduce the width of the depletion region near the back surface of the perovskite, thereby enhancing the hole extraction. Particularly, after the addition of CsSn0.2Pb0.8I3 quantum dots (QDs), improvement of the power conversion efficiency (PCE) from 12.80 to 14.22% can be obtained, in comparison with the pristine device. Moreover, the experimental results are analyzed through the simulation of the one-dimensional perovskite/tin-doped PQDs heterojunction.

Influence of Ag@SiO2 with Different Shell Thickness on Photoelectric Properties of Hole-Conductor-Free Perovskite Solar Cells.

In this paper, Ag@SiO2 core-shell nanoparticles (NPs) with different shell thicknesses were prepared experimentally and introduced into the photosensitive layer of mesoscopic hole-conductor-free perovskite solar cells (PSCs) based on carbon counter electrodes. By combining simulation and experiments, the influences of different shell thickness Ag@SiO2 core-shell nanoparticles on the photoelectric properties of the PSCs were studied. The results show that, when the shell thickness of 0.1 wt% Ag@SiO2 core-shell nanoparticles is 5 nm, power conversion efficiency is improved from 13.13% to 15.25%, achieving a 16% enhancement. Through the measurement of the relevant parameters of the obtained perovskite film, we found that this gain not only comes from the increase in current density that scholars generally think, but also comes from the improvement of the film quality. Like current gain, this gain is related to the different shell thickness of Ag@SiO2 core-shell nanoparticles. Our research provides a new direction for studying the influence mechanism of Ag@SiO2 core-shell nanoparticles in perovskite solar cells.

MYC Participates in Lipopolysaccharide-Induced Sepsis via Promoting Cell Proliferation and Inhibiting Apoptosis.

OBJECTIVE: This study aimed to explore the potential mechanism of MYC proto-oncogene, BHLH Transcription Factor (MYC) gene, on sepsis. MATERIALS AND METHODS: In this experimental study, rat-derived H9C2 cardiomyocyte cells were cultured in vitro, followed by lipopolysaccharide (LPS) treatment with different concentration gradients. The cholecystokinin octapeptide (CCK-8) assay, enzyme-linked immunoassay (ELISA) assay, quantitative reverse transcription polymerase chain reaction (qRT-PCR), cell transfection, Western blot and flow cytometry were used to observe the cellular apoptosis and proliferation of cells in both treated LPS groups and normal control group. RESULTS: The result of CCK-8 assay showed that silencing MYC inhibited cellular proliferation of sepsis in absence or presence of LPS treatment. ELISA assay showed that the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were decreased in MYC silenced group, but they were increased after LPS treatment. Moreover, Flow cytometry assay showed that MYC silencing contributed to the apoptosis of sepsis cells. Furthermore, the expression of inflammatory factors showed that MYC silencing elevated the expression of inflammation factors. CONCLUSION: MYC might take part in the process of LPS induced sepsis through suppressing apoptosis and inducing cell proliferation. Moreover, MYC might reduce inflammation during the progression of LPS induced sepsis.

Oral Maintenance Chemotherapy Using S-1/Capecitabine in Metastatic Nasopharyngeal Carcinoma Patients After Systemic Chemotherapy: A Single-Institution Experience.

BACKGROUND: In this study, we retrospectively evaluated a series of metastatic nasopharyngeal carcinoma (mNPC) patients who received oral maintenance chemotherapy using S-1/capecitabine after systemic chemotherapy and local radiation therapy, and aimed to explore potential efficient treatment strategies for this subset of patients. PATIENTS AND METHODS: Thirty-seven patients with mNPC (19 newly diagnosed metastatic patients and 18 metastatic cases after definitive chemoradiotherapy) who received the treatment strategies mentioned above were analyzed. RESULTS: After a median follow-up time of 37 months, the 3-year progression-free survival and overall survival (OS) rates were 47.6% and 87.7%, respectively. The median time to progression was 27.6 months, while the median OS was not reached at time of last follow-up. The most common acute adverse events were hematological and gastrointestinal toxicity, and all were tolerable and curable. CONCLUSION: Oral maintenance chemotherapy using S-1/capecitabine in mNPC patients after systemic chemotherapy could yield a superb outcome. Further multicenter prospective clinical trials are warranted.

Effects of oral maintenance chemotherapy and predictive value of circulating EBV DNA in metastatic nasopharyngeal carcinoma.

BACKGROUND/OBJECTIVES: Oral maintenance chemotherapy can effectively prolong overall survival (OS) in many types of metastatic cancer, but its role in metastatic nasopharyngeal carcinoma (mNPC) is unclear. In this study, the efficacy of oral maintenance chemotherapy in mNPC and the effectiveness of circulating tumor EBV-DNA for screening patients were evaluated. METHODS: Between June 2016 and December 2017, 141 patients with mNPC who received platinum-based systemic chemotherapy were included (median follow-up time, 21 months). Patients were classified into two groups according to the administration of oral maintenance chemotherapy. Plasma samples were collected before, during, and after treatment for the measurement of circulating EBV DNA. RESULTS: The 2-year OS was higher for patients who received maintenance chemotherapy than for patients without maintenance chemotherapy (78.9% vs 62.7%, P = .016). Patients with undetectable posttreatment EBV-DNA after 4-6 cycles of systemic chemotherapy (n = 73) had a higher 2-year OS than that of patients with detectable EBV-DNA (n = 68) (82.16% vs 51.45%, P = .001). For patients with undetectable posttreatment EBV-DNA, OS was better for those with maintenance chemotherapy than for those without (86.7% vs 73%, P = .027). For patients with detectable posttreatment EBV-DNA, maintenance chemotherapy did not improve outcomes (49.5% vs 55.4%, P = .824). The most common acute events were hematological toxicity, and all were tolerable and curable. CONCLUSIONS: Oral maintenance chemotherapy with S1 or capecitabine can improve OS in mNPC. Posttreatment EBV-DNA was not only an independent prognosis factor for mNPC but also can screen out beneficiaries of maintenance chemotherapy.