Surface modification of titanium carbide MXene monolayers (Ti2C and Ti3C2) via chalcogenide and halogenide atoms.

Inspired by the recent successful growth of Ti2C and Ti3C2 monolayers, here, we investigate the structural, electronic, and mechanical properties of functionalized Ti2C and Ti3C2 monolayers by means of density functional theory calculations. The results reveal that monolayers of Ti2C and Ti3C2 are dynamically stable metals. Phonon band dispersion calculations demonstrate that two-surface functionalization of Ti2C and Ti3C2via chalcogenides (S, Se, and Te), halides (F, Cl, Br, and I), and oxygen atoms results in dynamically stable novel functionalized monolayer materials. Electronic band dispersions and density of states calculations reveal that all functionalized monolayer structures preserve the metallic nature of both Ti2C and Ti3C2 except Ti2C-O2, which possesses the behavior of an indirect semiconductor via full-surface oxygen passivation. In addition, it is shown that although halide passivated Ti3C2 structures are still metallic, there exist multiple Dirac-like cones around the Fermi energy level, which indicates that semi-metallic behavior can be obtained upon external effects by tuning the energy of the Dirac cones. In addition, the computed linear-elastic parameters prove that functionalization is a powerful tool in tuning the mechanical properties of stiff monolayers of bare Ti2C and Ti3C2. Our study discloses that the electronic and structural properties of Ti2C and Ti3C2 MXene monolayers are suitable for surface modification, which is highly desirable for material property engineering and device integration.

Dynamic contrast-enhanced magnetic resonance imaging: A novel approach to assessing treatment in locally advanced esophageal cancer patients.

AIMS: This study aims to investigate the potential application of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to predict concurrent chemoradiation (CRT) in locally advanced esophageal carcinoma. PATIENTS AND METHODS: This study involved 33 patients with locally advanced esophageal cancer and treated with CRT. The patients underwent DCE-MRI before CRT (pre) and 3 weeks after starting CRT (mid). The patients were categorized into two groups: complete response (CR) and non-complete response (non-CR) after 3 months of treatment. The quantitative parameters of DCE-MRI (Ktrans, Kep, and Ve), the changes and ratios of parameters (ΔKtrans, ΔKep, ΔVe, rΔKtrans, rΔKep, and rΔVe), and the relative ratio in the tumor area and a normal tube wall (rKtrans, rKep, and rVe) were calculated and compared between two timeframes in two groups, respectively. Moreover, the receiver operating characteristics (ROC) statistical analysis was used to assess the above parameters. RESULTS: We divided 33 patients into two groups: 22 in the CR group and 11 in the non-CR group. During the mid-CRT phase in the CR group, both Ktrans and Kep rapidly decreased, while only Kep decreased in the non-CR group. The pre-Ktrans and pre-Kep in the CR group were substantially higher compared to the non-CR group. Moreover, the rKtrans was also apparently observed as higher at pre-CRT in the CR group compared to the non-CR group. The ROC analysis demonstrated that the pre-Ktrans could be the best parameter to evaluate the treatment performance (AUC = 0.74). CONCLUSION: Pre-Ktrans could be a promising parameter to forecast how patients with locally advanced esophageal cancer will respond to CRT.

[Association between polymorphism of CASP and NOX3 with risk of noise-induced hearing loss].

Objective: To explore the effect of gene polymorphism on workers suffering from noise induced hearing loss (NIHL) . Methods: In May 2019, a case-control study was conducted to select noise exposed workers in five factories in Zhejiang Province from 2017 to 2018. The average hearing threshold of binaural high frequency (3, 4, 6 kHz) was >25 dB (A) as the NIHL group, and the hearing threshold of any language frequency (0.5, 1, 2 kHz) was ≤25 dB (A) as the non NIHL group, with 307 people in each group. The general demographic data, occupational history, pure tone audiometry results and oral swab mucosal samples of noise exposed workers were collected, and the DNA of oral mucosal cells was extracted. The relationship between genetic risk score (GRS) and NIHL was analyzed, single nucleotide polymorphisms (SNP) were genotyped, the relationship between genotype and NIHL was analyzed by logistic regression, and the relationship between haplotype and NIHL was analyzed by R language. Results: After adjusting for gender, age, education and working years, the risk of NIHL among workers carrying cysteine-aspartic acid protease 3 gene (CASP3) rs1049216 recessive model GG genotype, rs6948 recessive model TT genotype, NADPH oxidase 3 gene (NOX3) rs12195525 additive model GT genotype and dominant model TT+GT genotype decreased (P<0.05) , the risk of disease was higher in workers with AA genotype carrying cysteine-aspartic acid protease 7 gene (CASP7) rs12415607 additive model (P<0.05) . There was a strong linkage disequilibrium (LD) relationship between rs1049216 and rs6948 (D'>0.8) . Haplotype AT and GG composed of rs1049216-rs6948 increased the risk of NIHL (P<0.05) . The risk of NIHL increased with the increase of GRS (OR=2.69, P<0.05) . Conclusion: Genotype polymorphisms at rs1049216 and rs6948 (CASP3) , rs12195525 (NOX3) , rs12415607 (CASP7) may be associated with susceptibility to NIHL.

Epileptic negative myoclonus restricted to lower limbs in benign childhood focal epilepsy with vertex spikes.

BACKGROUND AND PURPOSE: The aim was to determine the electroclinical findings in benign childhood focal epilepsy with vertex spikes (BEVS) with epileptic negative myoclonus (ENM) restricted to the lower limbs. METHODS: The electroencephalogram database of Peking University First Hospital and medical records of patients with BEVS and ENM restricted to the lower limbs were reviewed. RESULTS: Twenty-seven patients with BEVS had ENM restricted to the lower limbs. Twelve started as ENM restricted to the lower limbs. The age at seizure onset ranged from 1.5 to 4.8 years. During the course, half of the 12 patients developed focal sensorimotor seizures and then were diagnosed as benign childhood epilepsy with centrotemporal spikes (BECTS), with BEVS (four cases) and without BEVS (two cases). Five of them had electrical status epilepticus during sleep (ESES) and met the diagnostic criteria of atypical benign partial epilepsy (ABPE). Fifteen of the 27 patients had ENM restricted to the lower limbs during the course. The age at seizure onset ranged from 1.3 to 9.8 years. All had ESES and were diagnosed as ABPE, 11 as ABPE with BEVS and four as ABPE evolving into BEVS. CONCLUSIONS: Benign childhood focal epilepsy with vertex spikes (BEVS) might represent a specific epileptic syndrome of the continuum of benign childhood focal epilepsy. ENM restricted to the lower limbs was a special phenomenon in BEVS. BEVS could overlap with BECTS or evolve into BECTS and further into ABPE and vice versa. Ignorance of vertex spikes with associated ENM restricted to the lower limbs might lead to a misunderstanding of BEVS, a specific type of benign childhood focal epilepsy.

Myocardial CT perfusion imaging and atherosclerotic plaque characteristics on coronary CT angiography for the identification of myocardial ischaemia.

AIM: To investigate the value of myocardial computed tomography (CT) perfusion imaging (CTP) and atherosclerotic plaque characteristics (APCs) identified on coronary CT angiography (CCTA) for the detection of myocardial ischaemia by using single-photon-emission CT (SPECT) as a reference. MATERIALS AND METHODS: Thirty-six patients (63.9% males) undergoing combined stress dynamic CTP and CCTA were enrolled and analysed. Myocardial blood flow (MBF) from CTP was quantified and compared between normal and abnormal segments. The ability of CTP and APCs to detect ischaemia was compared to that of SPECT. RESULTS: Nineteen patients with 78 segments had perfusion abnormalities on CTP. A significant difference was seen in MBF values between normal (118.51±27.86 ml/100 ml/min) and hypoperfused (79.60±21.35 ml/100 ml/min) segments (t=15.832, p<0.05). The sensitivity and specificity for identifying ischaemia were 90.91% and 94.97%, respectively, on a per-segment basis, resulting in a r value of 0.737 (p<0.05). On a per-vessel basis, the sensitivity and specificity for detecting ischaemia were 86.67% and 84.62%, respectively, for CTP; 93.33% and 58.97%, respectively, for CCTA; and 86.67% and 87.18%, respectively, for CTP combined with CTA, with an area under the receiver-operator characteristic curve (AUC) being 0.87 (p<0.05) and 0.887 (p<0.05) for CTP and its combination with CTA, respectively. On CCTA, 55 vessels with APCs were detected, with an AUC of 0.737 (p<0.05) for APCs combined with CCTA stenosis and 0.802 (p<0.05) for APCs combined with CTP. CONCLUSIONS: Dynamic stress CTP shows good correlation with SPECT for the detection of ischaemia. Additionally, combining APCs with CCTA stenosis has the ability to discriminate ischaemic stenosis.

[Application of scalp-recorded high-frequency oscillations in epileptic encephalopathy with continuous spike-and-wave during sleep].

OBJECTIVE: To investigate the clinical significance of high-frequency oscillations (HFOs) on scalp electroencephalography (EEG) in patients with epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS). METHODS: Twenty-one CSWS patients treated for epilepsy from January 2006 to December 2016 in Pediatric Department of Peking University First Hospital were enrolled into the study. Selected clinical variables including gender, age parameters, seizure frequencies and antiepileptic drugs were compared between (a). HFO-positive group and HFO-negative group before methylprednisolone treatment and (b). excellent seizure outcome group and not-excellent seizure outcome group after methylprednisolone treatment. Interictal HFOs and spikes in pre- and post-methylprednisolone scalp EEG were measured and analyzed. RESULTS: Before methylprednisolone treatment, there were 12 of 21 (57%) CSWS patients had HFOs, with a mean value 43.17 per 60 s per patient. The 12 patients with HFOs tended to have more frequent epileptic negative myoclonus/atonic/myoclonus/atypical absences than those without HFOs in a month before methylprednisolone treatment. A total of 518 HFOs and 22 592 spikes were found in the pre-methylprednisolone EEG data of 21 patients, and 441 HFOs (86%) were associated with spikes. The highest amplitudes of HFOs were significantly positively correlated with that of spikes (r=0.279, P<0.001). Rates reduced by methylprednisolone treatment were statistically significant for both HFOs (P=0.002) and spikes (P=0.006). The percentage of reduction was 91% (473/518) and 39% (8 905/22 592) for spikes and HFOs, respectively. The percentage of spike and HFOs changes was respectively 100% decrease and 47% decrease in the excellent seizure outcome group, and they were 79% decrease and 18% increase in the not-excellent seizure outcome group. CONCLUSION: Prevalence of HFOs might reflect some aspect of epileptic activity. HFOs were more sensitive to methylprednisolone treatment than spikes and had a good correlation with the prognosis of seizures, and HFOs could be applied to assess epilepsy severity and antiepileptic therapy.

Effect of compound Maqin decoction on TGF-ß1/Smad proteins and IL-10 and IL-17 content in lung tissue of asthmatic rats.

In this research, compound Maqin decoction (CMD) has been shown to positively affect in airway inflammation of asthma models. We evaluated the effects of CMD on the expression of transforming growth factor (TGF)-ß1/Smad proteins, interleukin (IL)-17, and IL-10 in lung tissue of asthmatic rats. Asthma was induced in a rat model using ovalbumin. After a 4-week treatment with CMD, rats were killed to evaluate the expression of TGF-ß1 and Smad proteins in lung tissue. IL-10 and IL-17 levels in lung tissue homogenates were determined by ELISA. The expression of TGF-ß1 and Smad3 protein increased, whereas expression of Smad7 protein decreased upon high-dose or low-dose treatment with CMD or by intervention with dexamethasone, compared to the control. There was a significant difference between treatment with a high dose CMD and the control treatment, but no significant difference was found between high-dose CMD treatment and dexamethasone intervention. The expression of TGF-ß1 and Smad7 protein increased, whereas the expression of Smad3 protein decreased in the model group compared to other groups. In the CMD high-dose group, low-dose group, and dexamethasone intervention group, the IL-17 concentrations in lung tissue homogenates were decreased, while IL-10 levels were increased. Again, there was a significant difference between CMD high-dose and control treatment, but not between CMD high-dose treatment and dexamethasone intervention. Thus, positive effects of CMD against asthmatic airway remodeling may be due to its regulatory effect on TGF-ß1, Smad3, and Smad7 protein levels and on cytokines such as IL-10 and IL-17.

Association of interleukin gene polymorphisms with the risk of coronary artery disease.

We conducted a case-control study to investigate the genetic variants Interleukin-1ß(IL-1ß) +3953 C/T (rs1143634), IL-6 -174G/C (rs1800795), IL-8 -251T/A (rs4073), and IL-10 -1082A/G (rs1800896) and -819C/T (rs1800871) in the development of coronary artery disease (CAD). A total of 410 individuals with CAD were enrolled between January 2012 and December 2014. Genotyping of the five gene polymorphisms was performed using the polymerase chain reaction combined with restriction fragment length polymorphism methodology. By multivariate logistic regression analysis, we found that the frequencies of the CC genotype and the C allele of IL-6 -174G/C were significantly correlated with a higher risk of CAD; the adjusted ORs (95%CIs) were 2.37 (1.37-4.14) and 1.49 (1.19-1.86), respectively. In addition, the AG and GG genotypes and the G allele of IL-10 -1082A/G were also significantly associated with a higher risk of CAD, and the ORs (95%CIs) were 1.42 (1.04-1.95), 2.16 (1.42-3.30), and 1.56 (1.27-1.93), respectively. However, IL-1ß+3953 C/T, IL-8 -251T/A, and IL-10 -819C/T did not significantly correlate with CAD risk. Our study suggests that the IL-6 -174G/C (rs1800795) and IL-10 -1082A/G (rs1800896) polymorphisms might be involved in the pathogenesis of CAD, and likely contribute to the genetic susceptibility for CAD.

Effect of atorvastatin on plasma NT-proBNP and inflammatory cytokine expression in patients with heart failure.

The aim of this study was to explore the effect of atorvastatin intervention on plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) and inflammatory cytokine levels in patients with heart failure (HF). One hundred and twenty-three HF patients were selected from our hospital and randomly divided into control (N = 61) and observation (N = 62) groups; the former received conventional treatment, while the latter were given conventional treatment combined with atorvastatin. Plasma NT-proBNP, inflammatory cytokines [high-sensitive C-reactive protein (hs-CRP), interleukin (IL)-6, IL-10] and cardiac function [left ventricular end-diastolic dimension (LVEDD), left ventricular ejection fraction (LVEF), end-diastolic maximum flow rate ratio (E/A)] were compared among groups. The effective rate of treating HF significantly increased after atorvastatin treatment. The plasma NT-proBNP, IL-6, IL-10, hs-CRP, and LVEDD levels significantly decreased (P < 0.05), while the LVEF and E/A levels significantly increased (P < 0.05) in the observation group compared to the control group and before intervention. The NT-proBNP and cytokine levels significantly differed among patients with different classes of heart function (P < 0.05); the NT-proBNP and cytokine levels increased with the severity of heart function. Pearson's correlation analysis revealed a negative correlation between the NT-proBNP and inflammatory cytokine levels and LVEF and E/A values, and a positive correlation between these factors and LVEDD (P < 0.05). In conclusion, atorvastatin significantly improves cardiac function; the mechanism atorvastatin action was related to the decrease in plasma NT-proBNP and inflammatory cytokine levels.

Early detection of acute radiation-induced lung injury with multi-section CT perfusion imaging: An initial experience.

AIM: To explore the value of 64-section computed tomography (CT) perfusion imaging (CTPI) in the early diagnosis of acute radiation-induced lung injury (ARILI). MATERIALS AND METHODS: Fifty-one patients with oesophageal cancers or malignant thymomas received postoperative radiation therapy with a 60-62 Gy dose and underwent CTPI at pre- and post-radiation therapy time points (week 0, week 4, week 8, and week 12 respectively). The CTPI values were prospectively compared and analysed in order to evaluate the diagnostic utility of CTPI in the early diagnosis of ARILI. RESULTS: Eighteen cases (18/51) of ARILI were diagnosed. The mean values of relative regional blood flow (rrBF), relative regional volume (rrBV), and relative regional permeability surface (rrPS) in the ARILI group were correspondingly higher than those of the non-ARILI group. At week 4, rrBF, rrBV, and rrPS in the ARILI group were significantly higher than those at pre-radiation (each p < 0.05). In the non-ARILI group, rrBF and rrBV were higher than those at pre-radiation (each p < 0.05); however, rrPS was not statistically different from that of pre-irradiation. Applying the diagnostic threshold value of rrPS = 1.22, the sensitivity, specificity, and positive and negative predictive values of CTPI for early diagnosis of ARILI were better than those of CT. CONCLUSION: CTPI metrics may reflect haemodynamic changes in the post-irradiation lung and can detect cases of early ARILI that appear normal at CT. CTPI is a promising technique for early diagnosis of ARILI.

[Development of a grading diagnostic model for schistosomiasis-induced liver fibrosis based on radiomics and clinical laboratory indicators].

OBJECTIVE: To investigate the feasibility of developing a grading diagnostic model for schistosomiasis-induced liver fibrosis based on B-mode ultrasonographic images and clinical laboratory indicators. METHODS: Ultrasound images and clinical laboratory testing data were captured from schistosomiasis patients admitted to the Second People's Hospital of Duchang County, Jiangxi Province from 2018 to 2022. Patients with grade I schistosomiasis-induced liver fibrosis were enrolled in Group 1, and patients with grade II and III schistosomiasis-induced liver fibrosis were enrolled in Group 2. The machine learning binary classification tasks were created based on patients'radiomics and clinical laboratory data from 2018 to 2021 as the training set, and patients'radiomics and clinical laboratory data in 2022 as the validation set. The features of ultrasonographic images were labeled with the ITK-SNAP software, and the features of ultrasonographic images were extracted using the Python 3.7 package and PyRadiomics toolkit. The difference in the features of ultrasonographic images was compared between groups with t test or Mann-Whitney U test, and the key imaging features were selected with the least absolute shrinkage and selection operator (LASSO) regression algorithm. Four machine learning models were created using the Scikit-learn repository, including the support vector machine (SVM), random forest (RF), linear regression (LR) and extreme gradient boosting (XGBoost). The optimal machine learning model was screened with the receiver operating characteristic curve (ROC), and features with the greatest contributions to the differentiation features of ultrasound images in machine learning models with the SHapley Additive exPlanations (SHAP) method. RESULTS: The ultrasonographic imaging data and clinical laboratory testing data from 491 schistosomiasis patients from 2019 to 2022 were included in the study, and a total of 851 radiomics features and 54 clinical laboratory indicators were captured. Following statistical tests (t = -5.98 to 4.80, U = 6 550 to 20 994, all P values < 0.05) and screening of key features with LASSO regression, 44 features or indicators were included for the subsequent modeling. The areas under ROC curve (AUCs) were 0.763 and 0.611 for the training and validation sets of the SVM model based on clinical laboratory indicators, 0.951 and 0.892 for the training and validation sets of the SVM model based on radiomics, and 0.960 and 0.913 for the training and validation sets of the multimodal SVM model. The 10 greatest contributing features or indicators in machine learning models included 2 clinical laboratory indicators and 8 radiomics features. CONCLUSIONS: The multimodal machine learning models created based on ultrasound-based radiomics and clinical laboratory indicators are feasible for intelligent identification of schistosomiasis-induced liver fibrosis, and are effective to improve the classification effect of one-class data models.

Kinetics of plasma cell-free DNA as a prospective biomarker to predict the prognosis and radiotherapy effect of esophageal cancer.

PURPOSE: The lack of reliable biomarkers for the prognosis and radiotherapy efficacy in esophageal cancer (EC) necessitates further research. The aim of our study was to investigate the predictive utility of plasma cell-free DNA (cfDNA) kinetics in patients with EC. MATERIALS AND METHODS: We retrospectively analyzed the clinical data and cfDNA levels (pre-radiotherapy [pre-RT] and post-radiotherapy [post-RT]) and the cfDNA kinetics (cfDNA ratio: post-RT cfDNA/pre-RT cfDNA) of 88 patients. We employed Kaplan-Meier curves to examine the relationship between cfDNA and overall survival (OS) as well as progression-free survival (PFS). Univariate and multivariate Cox regression analyses were executed to ascertain the independent risk factors in EC. RESULTS: The pre-RT cfDNA levels were positively correlated with clinical stage (P=0.001). The pre-RT cfDNA levels (cutoff value=16.915ng/mL), but not the post-RT cfDNA levels, were linked to a diminished OS (P<0.001) and PFS (P=0.0137). CfDNA kinetics (cutoff value=0.883) were positively associated with OS (P=0.0326) and PFS (P=0.0020). Notably, we identified independent risk factors for OS in EC treated with RT, including cfDNA ratio (high/low) (HR=0.447 [0.221-0.914] P=0.025), ECOG (0/1/2) (HR=0.501 [0.285-0.880] p=0.016), and histological type (esophagal squamous cell carcinoma [ESCC]/non-ESCC) (HR=3.973 [1.074-14.692] P=0.039). CONCLUSION: Plasma cfDNA kinetics is associated with prognosis and radiotherapy effect in EC undergoing RT, suggesting potential clinical application of a cheap and simple blood-based test.

Distinctive microbial community structure in highly stratified deep-sea brine water columns.

Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools.

Microplastic pollution and regulating factors in the surface sediment of the Xuande Atolls in the South China Sea.

Microplastics are widely present in the marine environment, but their pollution and potential risk assessment in the seabed sediments have not been well addressed in remote sea areas. In this study, microplastics in 50 surface sediment samples from the Xuande Atolls at the Xisha of the South China Sea were studied. There were 20 samples with detectable microplastics of 5-20 items kg-1. They were all fibers in shapes and blue/transparent in colors with the dominant chemical component of polyester and the typical size of 0.02-3 mm. We found a large spatial variability of microplastic abundance in the surface sediment with generally low or undetectable levels in the lagoon deposits and the offshore deep-sea sediments but elevated abundances in the slope sediments of the Xuande Atolls. Correlation analyses suggested that microplastic variability in the Xisha sediment was less affected by local environmental parameters such as water depth, sediment particle size, organic carbon content, and sediment types. We also found that elevated microplastics in the seabed sediments on various sides of the Xuande Atolls could be related to the seasonal change in monsoon-driven currents. Finally, a low risk of microplastic pollution in the surface sediment of the Xisha is concluded based on the assessments of the polymer hazard index and the pollution load index. These findings provide not only a baseline understanding of microplastics but also their dynamics in the surface sediment of the remote Xisha area of the South China Sea.

Role of diatom-derived oxylipins in organic phosphorus recycling during coastal diatom blooms in the northern South China Sea.

Diatom-bacteria interactions and the associated bloom dynamics have not been fully understood in the coastal oceans. Here, we focus on the polyunsaturated aldehydes (PUAs) produced by diatoms in the post-bloom phase and look into their roles in microbial phosphorus (P) recycling outside of a P-limited estuary. The phytoplankton community in the bloom was dominated by PUAs-producing diatoms (Skeletonema costatum, Thalassiosira spp., and Pesudonitzschia delicates) with elevated concentrations of biogenic particulate PUAs. In addition, there were micromolar levels of particle-adsorbed PUAs hotspots with distinct compositions in and out of the bloom determined by a combining large-volume filtration and on-site derivation method. Field experiments were conducted to further assess the responses of particle-attached bacteria (PAB) to different PUAs amendments. We found no differences in the alkaline phosphatase (APase) activity and the abundance of PAB between inside and outside the bloom at a low PUAs dosage (<30 µM). However, for a high PUAs dosage (300 µM), APase activity and PAB growth were reduced significantly outside the bloom but no influences within the bloom. Our findings indicate that the hotspot-level oxylipins may play essential roles in bacterial P-remineralization in P-limited coastal areas. PAB can adapt to the high level of PUAs released by diatoms (or their resulting detritus) and potentially maintain a high rate of organic P recycling during the late stages of diatom blooms. Consequently, the interaction between oxylipin-rich diatoms and bacteria may affect phytoplankton blooms and carbon sequestration in the coastal oceans.

Microplastic contamination in coral reef fishes and its potential risks in the remote Xisha areas of the South China Sea.

Microplastics are recognized as a newly emerging threat to marine organisms as they can be ingested and accumulated through multiple trophic levels. However, microplastic contamination and its potential risk assessment in coral reef fishes have been less addressed, particularly in remote ocean regions. In this study, microplastics in 167 samples of coral reef fish (a total of eighteen species) from the Xisha areas of the South China Sea were studied. There were fifteen species of coral reef fish contaminated by microplastics with an average occurrence rate of 29.3 %. The shape of microplastics in the fishes was mostly fibrous with small sizes (400-900 µm) and light colors (transparent and blue). The dominant types of microplastic polymers are polyamide and polyethylene terephthalate, accounting for 77 % and 11 % of microplastics in the fish body. There were generally more microplastics in the herbivorous fishes than the carnivorous ones. The highest microplastic abundance and occurrence was found in parrotfish due to its direct feeding on the microplastics-contaminated corals. In addition, there were much more microplastics in the gastrointestinal tracts than in the gills of the Xisha fishes. Microplastic abundance was found negatively correlated with the trophic level of the Xisha fishes supporting a stronger microplastic impact at lower levels of marine animals. Finally, a risk assessment using the polymer hazard index (PHI) revealed that microplastic contamination in the Xisha fishes was lower than those in the eutrophic coast. Our study provides new evidence for the widespread presence of microplastic contamination in the fishes of the remote Xisha coral reefs.

Transparent exopolymer particle dynamics along a shelf-to-sea gradient and impacts on the regional carbon cycle.

Transparent exopolymer particles (TEPs) have drawn extensive attention in recent decades due to their crucial role in the biogeochemical and ecological processes of the ocean. However, TEP distribution and fluxes are relatively less addressed in the shelf-seas, where its variability can be affected by not only biology but also complex physical dynamics. Here, we present a comprehensive study of TEP from the coast to the basin (12 sampling sites) of the northern South China Sea (NSCS). We found a large TEP variability from 0.6 to 78.6 µg Xeq. L-1 with higher levels in the coastal waters than the offshore epipelagic waters and the deep waters. In addition, the spatial distribution of TEP was significantly correlated to the cross-shelf change of temperature, salinity, and chlorophyll-a, revealing the complex physical-biogeochemical controls on TEP variability. We found the TEP dynamics nearshore largely influenced by the sedimentation and transportation of TEP-rich aggregates from the river plume. The contribution of TEP to particulate organic carbon (POC) increased gradually when approaching the shore from the sea, suggesting an elevated role of TEP in the coastal carbon cycle. Finally, a good correlation of particle-attached bacteria (PAB) with TEP but not POC revealed a preferential utilization of TEP by PAB. Thus, TEP may play an essential role in the recycling of carbon and nitrogen in the shelf-sea. These findings are crucial for understanding of the TEP dynamics under a changing environment and the associated impacts on the oceanic carbon cycle.

Immature dendritic cells expressing indoleamine 2,3-dioxygenase suppress ovalbumin-induced allergic airway inflammation in mice.

BACKGROUND: Proliferation of activated CD4+ T lymphocytes is inhibited by indoleamine 2,3-dioxygenase (IDO). OBJECTIVE: We undertook the present study to test the hypothesis that IDO-expressing immature DCs (imDCs) can restore immune tolerance in mice suffering from allergic airway inflammation. METHODS: imDCs were generated from murine bone marrow cells using granulocyte-macrophage colony-stimulating factor.The imDCs were subsequently transfected with an IDO expression vector (pEGFP-N1-IDO). Surface marker expression, including CD11c, MHCII, CD80, and CD86, was analyzed using flow cytometry. IDO-expressing imDCs were injected into the trachea of ovalbumin (OVA)-sensitized mice, and lung histopathology and cytokine expression in bronchoalveolar lavage fluid were assessed. The splenic CD4+ T cells of OVA-sensitized mice were isolated and co-cultured with pEGFP-N1-IDO-expressing imDCs, and apoptosis of CD4+ T cells was detected using the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. RESULTS: Expression of IDO in imDCs did not alter cell surface molecule expression. We observed marked lung inflammation, elevated total cell and eosinophil count, and altered cytokine levels in OVA-sensitized mice. These parameters improved upon inoculation with IDO-expressing imDCs. Co-culture with IDO-expressing imDCs also induced apoptosis, inhibited IL-4 and IL-5 expression, and upregulated IFN-gamma expression in CD4+ T cells. CONCLUSIONS: IDO-expressing imDCs induced T(H)2 cell apoptosis and reduced T(H)2 cell activation and allergic airway inflammation in OVA-sensitized mice. Thus, upregulation of IDO expression may provide a novel immunointervention strategy for asthma treatment.

Polybrominated diphenylethers (PBDEs) alter larval settlement of marine benthic polychaetes.

Polybrominated diphenylethers (PBDEs) are found ubiquitously in marine environments worldwide. Sediment is the major sink of PBDEs, with the congener BDE 47 being most abundant. In this study, laboratory experiments were carried out to test the hypothesis that contamination of BDE 47 at environmentally realistic sediment concentrations can alter polychaete larval settlement. Using multiple-choice experiment, settlement of three polychaete species (Pseudopolydora vexillosa, Polydora cornuta, and Capitella sp. I) on four types of spiked sediment was studied and compared: (i) low BDE 47 concentration (0.5 ng g(-1) dry weight); (ii) high BDE 47 concentration (3.0 ng g(-1) dry weight), (iii) hexane (solvent control), and (iv) natural sediment (control). Our results showed that settlement of P. vexillosa and Capitella sp. I larvae was significantly promoted, while settlement of P. cornuta reduced, at high BDE 47 concentration in sediment compared with the respective controls under both short- (24 h) and long-term (4 week) exposures. After 4 weeks, body burden of BDE 47 in all polychaete species was directly related to the spike concentration, and body length of settled juveniles of P. vexillosa and Capitella sp. I at the high-concentration treatment was significantly longer compared with that of other treatments and controls. For the first time, we demonstrated that environmentally realistic concentrations of BDE 47 in sediment can affect polychaete settlement in species-specific and dose-dependent manners. Given the global contamination of PBDE in marine sediment, BDE 47 may potentially alter the settlement pattern of marine polychaetes and hence their benthic composition over large areas.

[Electroclinical characteristics of epilepsy children with midline epileptiform discharges related epileptic negative myoclonus as the first symptom].

Objective: To investigate the electroclinical findings in epilepsy children with epileptic negative myoclonus (ENM) restricted to the lower limb as the first seizure type. Methods: Each retrieved electroencephalogram record performed between March 2011 and March 2018 at the Department of Pediatrics of Peking University First Hospital was searched with "midline" . There were 302 records of 175 patients with "benign" or "functional" midline spikes. A retrospective review of each patient's hospital record was performed. Thirteen patients had ENM restricted to the lower limb as the first seizure type. The clinical and electroencephalogram characteristics of them were analyzed. Results: Thirteen patients manifested ENM restricted to the lower limb as the first seizure type, diagnosed as benign childhood focal epilepsy with vertex spikes (BEVS). Six patients had ENM as the first and only seizure type during the short-time follow-up. Among them, there were 1 male and 5 females. The age at seizure onset was (2.5±0.7) years. One of them had electrical status epilepticus during sleep (ESES) identified on electroencephalogram at theage of 4 years and 8 months. The last follow-up age was (3.8±1.5) years. The remaining 7 patients developed nocturnal focal motor seizures. Among them, there were 4 males and 3 females. The age at seizure onset was (3.5±0.7) years. Two of them were diagnosed as BEVS evolving into benign childhood epilepsy with centrotemporal spikes (BECTS) and 5 were diagnosed as BEVS concurring with BECTS. The age at focal seizures was (4.1±0.6) years. The interval ranged from 1 month to 1 years. Six of 7 patients had electrical ESES with the age of (5.2±1.0) years. All had developmental regression, further diagnosed as atypical benign partial epilepsy (ABPE). The median age at last follow-up was 5.9 years. Five of 13 patients had repeated electroencephalogram records at our apartment, showing that epileptiform discharges in midline regions were significantly reduced either in frequency or amplitude with the improvement of ENM restricted to the lower limb and that independent epileptiform discharges in Rolandic regions from midline regions were noticed with the onset of nocturnal focal seizures. Conclusions: ENM restricted to the lower limb has a close association with vertex (midline) epileptiform discharges. ENM restricted to the lower limb as the first seizure type is a peculiar phenomenon of BEVS. Some patients could evolve into BECTS or overlap with BECTS, and further into ABPE. The age of seizure onset in BEVS with ENM restricted to the lower limb as the first symptom is a little earlier than in BECTS. Ignorance of the close association between midline spikes and ENM restricted to the lower limb may lead to misdiagnosis of these patients.