Fumarate suppresses B-cell activation and function through direct inactivation of LYN.

Activated B cells increase central carbon metabolism to fulfill their bioenergetic demands, yet the mechanistic basis for this, as well as metabolic regulation in B cells, remains largely unknown. Here, we demonstrate that B-cell activation reprograms the tricarboxylic acid cycle and boosts the expression of fumarate hydratase (FH), leading to decreased cellular fumarate abundance. Fumarate accumulation by FH inhibition or dimethyl-fumarate treatment suppresses B-cell activation, proliferation and antibody production. Mechanistically, fumarate is a covalent inhibitor of tyrosine kinase LYN, a key component of the BCR signaling pathway. Fumarate can directly succinate LYN at C381 and abrogate LYN activity, resulting in a block to B-cell activation and function in vitro and in vivo. Therefore, our findings uncover a previously unappreciated metabolic regulation of B cells, and reveal LYN is a natural sensor of fumarate, connecting cellular metabolism to B-cell antigen receptor signaling.

IP3R1-mediated MAMs formation contributes to mechanical trauma-induced hepatic injury and the protective effect of melatonin.

INTRODUCTION: There is a high morbidity and mortality rate in mechanical trauma (MT)-induced hepatic injury. Currently, the molecular mechanisms underlying liver MT are largely unclear. Exploring the underlying mechanisms and developing safe and effective medicines to alleviate MT-induced hepatic injury is an urgent requirement. The aim of this study was to reveal the role of mitochondria-associated ER membranes (MAMs) in post-traumatic liver injury, and ascertain whether melatonin protects against MT-induced hepatic injury by regulating MAMs. METHODS: Hepatic mechanical injury was established in Sprague-Dawley rats and primary hepatocytes. A variety of experimental methods were employed to assess the effects of melatonin on hepatic injury, apoptosis, MAMs formation, mitochondrial function and signaling pathways. RESULTS: Significant increase of IP3R1 expression and MAMs formation were observed in MT-induced hepatic injury. Melatonin treatment at the dose of 30 mg/kg inhibited IP3R1-mediated MAMs and attenuated MT-induced liver injury in vivo. In vitro, primary hepatocytes cultured in 20% trauma serum (TS) for 12 h showed upregulated IP3R1 expression, increased MAMs formation and cell injury, which were suppressed by melatonin (100 µmol/L) treatment. Consequently, melatonin suppressed mitochondrial calcium overload, increased mitochondrial membrane potential and improved mitochondrial function under traumatic condition. Melatonin's inhibitory effects on MAMs formation and mitochondrial calcium overload were blunted when IP3R1 was overexpressed. Mechanistically, melatonin bound to its receptor (MR) and increased the expression of phosphorylated ERK1/2, which interacted with FoxO1 and inhibited the activation of FoxO1 that bound to the IP3R1 promoter to inhibit MAMs formation. CONCLUSION: Melatonin prevents the formation of MAMs via the MR-ERK1/2-FoxO1-IP3R1 pathway, thereby alleviating the development of MT-induced liver injury. Melatonin-modulated MAMs may be a promising therapeutic therapy for traumatic hepatic injury.

Mechanistic insights and catalytic enhancement of phenolic wastewater supercritical water gasification: A combined experiment and density functional theory study.

Supercritical water gasification technology provides a favorable technology to achieve pollution elimination and resource utilization of phenolic wastewater. In this study, the reaction mechanism of phenolic wastewater supercritical water gasification was investigated using a combination of experimental and computational methods. Five reaction channels were identified to elucidate the underlying pathway of phenol decomposition. Importantly, the rate-determining step was found to be the dearomatization reaction. By integrating computational and experimental analyses, it was found that phenol decomposition via the path with the lowest energy barrier generates cyclopentadiene, featuring a dearomatization barrier of 70.97 kcal/mol. Additionally, supercritical water plays a catalytic role in the dearomatization process by facilitating proton transfer. Based on the obtained reaction pathway, alkali salts (Na2CO3 and K2CO3) are employed as a catalyst to diminish the energy barrier of the rate-determining step to 40.00 kcal/mol and 37.14 kcal/mol. Alkali salts catalysis significantly improved carbon conversion and pollutant removal from phenolic wastewater, increasing CGE from 58.44% to 93.55% and COD removal efficiency from 94.11% to 99.79%. Overall, this study provides a comprehensive understanding of the decomposition mechanism of phenolic wastewater in supercritical water.

Azonia-Naphthalene: A Cationic Hydrophilic Building Block for Stable N-Type Organic Mixed Ionic-Electronic Conductors.

Conjugated polymers that can efficiently transport both ionic and electronic charges have broad applications in next-generation optoelectronic, bioelectronic, and energy storage devices. To date, almost all the conjugated polymers have hydrophobic backbones, which impedes efficient ion diffusion/transport in aqueous media. Here, we design and synthesize a novel hydrophilic polymer building block, 4a-azonia-naphthalene (AN), drawing inspiration from biological systems. Because of the strong electron-withdrawing ability of AN, the AN-based polymers show typical n-type charge transport behaviors. We find that cationic aromatics exhibit strong cation-π interactions, leading to smaller π-π stacking distance, interesting ion diffusion behavior, and good morphology stability. Additionally, AN enhances the hydrophilicity and ionic-electronic coupling of the polymer, which can help to improve ion diffusion/injection speed, and operational stability of organic electrochemical transistors (OECTs). The integration of cationic building blocks will undoubtedly enrich the material library for high-performance n-type conjugated polymers.

Ultrasensitive HPLC-MS Quantification of S-(2-Succino) Cysteine Based on Ethanol/Acetyl Chloride Derivatization in Fumarate Accumulation Cells.

Succination is a nonenzymatic and irreversible post-translational modification (PTM) with important biological significance, yielding S-(2-succino) cysteine (2SC) residue. This PTM is low in abundance and often requires a large amount of protein samples for 2SC quantification. In this work, an efficient quantification method based on ethanol/acetyl chloride chemical derivatization was developed. The three carboxyl groups of 2SC were all esterified to increase hydrophobicity, greatly improving its ionization efficiency. The sensitivity was increased by 112 times; the limit of detection was reduced to 0.885 fmol, and the protein usage was reduced by at least 10 times. The established method was used to detect the overall concentration of 2SC in fumarate accumulation cells quantitatively.

Ischemia/reperfusion-induced MiD51 upregulation recruits Drp1 to mitochondria and contributes to myocardial injury.

The translocation of Drp1 from the cytosol to mitochondria leads to Drp1 activation and mitochondrial fission in myocardial ischemia/reperfusion (MI/R). However, the molecular mechanism underlying mitochondrial Drp1 translocation remains poorly understood. Mitochondrial Drp1 recruitment relies on 4 binding partners including MiD49, MiD51, Mff and Fis1. This study was to elucidate which one facilitate mitochondrial Drp1 translocation and its role in MI/R injury. MI/R was induced by ligating the left anterior descending coronary artery for 30 min and subsequent reperfusion for 3 h. Primary neonatal cardiomyocytes were subjected to hypoxia for 2 h and reoxygenation for 4 h. SiRNA or Adeno-associated virus (AAV) expressing shRNA was used to knock down the key binding partner in vitro or in vivo respectively. The expression of MiD51 rather than other binding partners (MiD49, Mff or Fis1) was increased after MI/R. MiD51 knockdown inhibited hypoxia/reoxygenation (H/R) or ischemia/reperfusion (I/R)-induced mitochondrial Drp1 translocation. SiRNA-induced knockdown of MiD51 suppressed mitochondrial oxidative stress, improved mitochondrial function and alleviate cellular injury in H/R cardiomyocytes. AAV-mediated knockdown of MiD51 reduced myocardial injury and improved cardiac function in the I/R hearts, while mitochondrial Drp1 translocation and cardiac function were not affected by MiD51 knockdown in the hearts without I/R. MiD51 is identified as the binding partner that promotes mitochondrial Drp1 translocation and contributes to MI/R injury. Inhibition of MiD51 may be a potential therapeutic target to alleviate MI/R injury.

Aging-induced pseudouridine synthase 10 impairs hematopoietic stem cells.

Aged hematopoietic stem cells (HSC) exhibit compromised reconstitution capacity and differentiation-bias towards myeloid lineage, however, the molecular mechanism behind it remains not fully understood. In this study, we observed that the expression of pseudouridine (Ψ) synthase 10 is increased in aged hematopoietic stem and progenitor cells (HSPC) and enforced protein of Ψ synthase 10 (PUS10) recapitulates the phenotype of aged HSC, which is not achieved by its Ψ synthase activity. Consistently, we observed no difference of transcribed RNA pseudouridylation profile between young and aged HSPC. No significant alteration of hematopoietic homeostasis and HSC function is observed in young Pus10-/- mice, while aged Pus10-/- mice exhibit mild alteration of hematopoietic homeostasis and HSC function. Moreover, we observed that PUS10 is ubiquitinated by E3 ubiquitin ligase CRL4DCAF1 complex and the increase of PUS10 in aged HSPC is due to aging-declined CRL4DCAF1- mediated ubiquitination degradation signaling. Taken together, this study for the first time evaluated the role of PUS10 in HSC aging and function, and provided a novel insight into HSC rejuvenation and its clinical application.

In-source fragmentation of nucleosides in electrospray ionization towards more sensitive and accurate nucleoside analysis.

Nucleosides have been found to suffer in-source fragmentation (ISF) in electrospray ionization mass spectrometry, which leads to reduced sensitivity and ambiguous identification. In this work, a combination of theoretical calculations and nuclear magnetic resonance analysis revealed the key role of protonation at N3 near the glycosidic bond during ISF. Therefore, an ultrasensitive liquid chromatography-tandem mass spectrometry system for 5-formylcytosine detection was developed with 300 fold signal enhancement. Also, we established a MS1-only platform for nucleoside profiling and successfully identified sixteen nucleosides in the total RNA of MCF-7 cells. Taking ISF into account, we can realize analysis with higher sensitivity and less ambiguity, not only for nucleosides, but for other molecules with similar protonation and fragmentation behaviors.

Assessing Left Ventricular Systolic Function in Patients with Pregnancy-Induced Hypertension Using Three-Dimensional Speckle Tracking Technology.

Objective: This study investigates the clinical utility of three-dimensional speckle tracking technology in assessing left ventricular systolic function in pregnancy-induced hypertension syndrome (PIH). Methods: We retrospectively enrolled 70 patients with diagnosed PIH treated at our institution between July 2019 and August 2021 as the study group. A total of 70 healthy pregnant women undergoing routine antenatal examinations at the same institution during the same period were included in the control group. Two-dimensional conventional echocardiography measured left ventricular parameters in both groups. Three-dimensional speckle tracking technology analyzed Left Ventricular Global Longitudinal Peak Strain (LVGLS), Left Ventricular Global Radial Peak Strain (LVGRS), and Left Ventricular Global Circumferential Peak Strain (LVGCS). Differences in left ventricular systolic function and pregnancy outcomes were compared. Results: In the study group, LVEDD, LVPWTd, and IVSTd (47.67±4.88, 10.68±1.21, 11.24±1.03) exceeded those in the control group (45.21±5.65, 8.17±0.98, 8.91±0.37). LVEF (62.12±5.63) was lower than the control group (65.25±5.17) (all P < .05). LVGLS, LVGCS, and LVGAS in the study group (-15.66±1.07, -20.17±2.89, -23.17±3.43) were higher than the control group (-20.14±1.27, -25.17±1.36, -37.68±3.29), while LVGRS (30.29±3.61) was lower than the control group (34.18±4.08) (all P < .05). The study group had 72.86% natural deliveries and 27.14% cesarean sections; the control group had 31.43% natural deliveries and 68.57% cesarean sections (all P < .05). Weeks of delivery and birth weight in the study group (36.87±1.23, 2.71±0.41) were lower than the control group (38.96±1.54, 3.41±0.78) (both P < .05). Conclusions: Compared to traditional methods, three-dimensional speckle tracking technology more sensitively detects left ventricular strain and rotation in PIH patients. It holds clinical relevance in early left ventricular dysfunction detection, effectively mitigating adverse pregnancy outcomes and warranting clinical adoption and application.

Nuclear expression of AFF2 C-terminus is a sensitive and specific ancillary marker for DEK::AFF2 carcinoma of the sinonasal tract.

DEK::AFF2 carcinoma of the sinonasal tract is an emerging entity. The tumor is typically characterized by papillary proliferation of non-keratinizing squamous epithelial cells with monotonous cytologic features, which may mimic other sinonasal tumors. The confirmation of this gene fusion has thus far relied solely on next-generation sequencing, fluorescence in situ hybridization (FISH), or reverse transcription polymerase chain reaction (RT-PCR). This current study aimed to validate an immunohistochemical assay for AFF2 C-terminus as an ancillary marker. We first analyzed publicly available RNA sequencing data of sinonasal tumors from the national center for biotechnology information (NCBI) sequence read archive and identified 3 DEK::AFF2 carcinomas out of 28 sinonasal tumors. The gene expression of AFF2 was significantly higher in the fusion-positive cases compared to the wild-type tumors (p < 0.001), while DEK was not. We then optimized an immunohistochemical assay with an anti-AFF2 C-terminus antibody for ancillary diagnosis. Seventeen DEK::AFF2 carcinomas, including 11 cases with predominantly low-grade morphology and one showing glandular differentiation, as well as 78 DEK FISH-negative sinonasal tumors were evaluated by AFF2 immunohistochemistry (IHC). Sixteen of the 17 DEK::AFF2 carcinomas showed nuclear AFF2 expression in ≥30% of tumor cells, including one decalcified case that failed FISH and RT-PCR confirmation. The one case that was negative for AFF2 IHC in the tumor cells also lacked expression in the internal positive control. It was thus considered a failure of the IHC rather than a truly negative case and was excluded from the statistical analysis. All DEK FISH-negative sinonasal tumors were negative for nuclear AFF2 expression. The nuclear expression of AFF2 IHC showed 100% sensitivity and specificity for DEK::AFF2 carcinoma. Accordingly, AFF2 IHC is a highly sensitive and specific ancillary marker that distinguishes DEK-AFF2 carcinoma from the other sinonasal tumors with overlapping morphological features and may be an especially useful alternative for decalcified specimens.

DEK-AFF2 fusion-associated papillary squamous cell carcinoma of the sinonasal tract: clinicopathologic characterization of seven cases with deceptively bland morphology.

A novel DEK-AFF2 fusion has been recently identified in four cases of basaloid to nonkeratinizing squamous cell carcinoma (SCC) in the sinonasal tract and middle ear with high-grade morphology. The exceptional response to immune checkpoint inhibitor in the first reported case highlights the potential clinical importance of identifying tumors with DEK-AFF2 fusions. We herein reported the first series of seven cases of DEK-AFF2 fusion-associated sinonasal SCC with deceptively bland morphology, including four cases of low-grade papillary Schneiderian carcinoma, which is a recently described tumor type with unknown molecular underpinnings. The DEK gene rearrangement was confirmed by DEK break-apart fluorescence in situ hybridization and DEK-AFF2 fusion transcripts were detected by reverse transcription polymerase chain reaction. In contrast to the previously reported DEK-AFF2 fusion-positive high-grade carcinomas, these tumors had a monotonous and bland morphology and were all initially diagnosed as sinonasal papilloma (SP) of various types, with or without dysplasia or carcinoma in situ. The tumor was characterized by mixed exophytic and inverted patterns, broad papillary fronds, acantholytic change, cellular monotony, dense neutrophilic infiltrates, and peripheral palisading. All tumors were diffusely positive for p40 or p63 and negative for NUT and p16. Molecular drivers associated with SP, including EGFR and KRAS mutations and both high and low-risk human papillomavirus infection, were negative in all cases. Although there was no overt stromal invasion or desmoplastic reaction in the initial specimens, these tumors tended to progress locoregionally through a prolonged clinical course and occasionally develop lymph node metastases, high-grade transformation, or extensively local destruction eventually leading to death. These justify more aggressive clinical management. Therefore, we propose the new terminology "DEK-AFF2 fusion-associated papillary SCC of the sinonasal tract" to better describe this clinicopathologically and molecularly distinct entity.

Turbidity compensation method based on Mie scattering theory for water chemical oxygen demand determination by UV-Vis spectrometry.

In view of the problem that chemical oxygen demand (COD) measurement in water using UV-Vis spectrometry was easily affected by turbidity, this paper proposed an analytical method for determining the complex refractive index of particles in water based on Lambert-Beer's law and K-K (Kramers-Kronig) relationship. The obtained complex refractive index was used to establish the turbidity compensation model in the COD characteristic spectral region, and the COD concentration inversion were achieved by using the PLS algorithm. The results show that the turbidity compensation method based on Mie scattering theory can improve the accuracy of COD measurement by UV-Vis spectroscopy. Compared with before turbidity compensation, R2 (determination coefficient) between true values and predicted values of COD increased from 0.2274 to 0.9629, and RMSE (root mean square error) of predicted values decreased from 21.73 to 3.12 mg L-1. Compared with 350 nm PC, derivative method, and improved MSC method, the turbidity compensation method for COD measurement based on Mie scattering theory is simple, fast, and highly accurate. And the calculated spectrum can represent the scattering characteristics of the measured spectrum. The average relative error between the fitted spectrum and the original normalized spectrum in the 55 mixed solutions was 0.52%, and the maximum relative error was 6.65%. This method can be useful for online COD measurement. Graphical abstract.

Identifying Self-Management Support Needs for Pregnant Women With Opioid Misuse in Online Health Communities: Mixed Methods Analysis of Web Posts.

BACKGROUND: The current opioid crisis in the United States impacts broad population groups, including pregnant women. Opioid use during pregnancy can affect the health and wellness of both mothers and their infants. Understanding women's efforts to self-manage opioid use or misuse in pregnancy is needed to identify intervention points for improving maternal outcomes. OBJECTIVE: This study aims to identify the characteristics of women in an online health community (OHC) with opioid use or misuse during pregnancy and the self-management support needs of these mothers. METHODS: A total of 200 web posts by pregnant women with opioid use participating in an OHC were double coded. Concepts and their thematic connections were identified through an inductive process until theoretical saturation was reached. Statistical tests were performed to identify patterns. RESULTS: The majority of pregnant women (150/200, 75.0%) in the OHC exhibited signs of misuse, and 62.5% (125/200) of the participants were either contemplating or pursuing dosage reduction. Self-managed withdrawal was more common (P<.001) than professional treatment among the population. A total of 5 themes of self-management support needs were identified as women sought information about the potential adverse effects of gestational opioid use, protocols for self-managed withdrawal, pain management safety during pregnancy, hospital policies and legal procedures related to child protection, and strategies for navigating offline support systems. In addition, 58.5% (117/200) of the pregnant women expressed negative emotions, of whom only 10.2% (12/117) sought to address their emotional needs with the help of the OHC. CONCLUSIONS: OHCs provide vital self-management support for pregnant women with opioid use or misuse. Women pursuing self-managed dosage reduction are prone to misinformation and repeated relapses, which can result in extreme measures to avoid testing positive for drug use at labor. The study findings provide evidence for public policy considerations, including universal screening of substance use for pregnant women, emphasis on treatment rather than legal punishment, and further expansion of the Drug Addiction Treatment Act waiver training program. The improvement of web-based platforms that can organize geo-relevant information, dispense clinically validated withdrawal schedules, and offer structured peer support is envisioned for harm reduction among pregnant women who opt for self-management of opioid misuse.

A self-assembled layer-by-layer surface modification to fabricate the neuron-rich model from neural stem/precursor cells.

BACKGROUND/PURPOSE: In vitro neural cell-based models have been widely used to mimic the in vivo neural tissue environments and quantitatively understand the effects of pharmaceutical molecules on neural diseases. Recently, several biomimetic neural tissue models have been widely developed by using biomaterials or surface modification. However, the complex protocols of material synthesis or surface modification lack an easy execution to fabricate the neuron favorite environment. METHODS: In this study, we utilized a layer-by-layer technique as a surface modification method for regulating the behaviors of neural stem/precursor cells (NSPCs) on material surfaces. Polyelectrolyte multilayers (PEMs) via alternate deposition of poly (allylamine hydrochloride) (PAH) and poly (sodium-4-styrenesulfonate) (PSS) were used to culture NSPCs. After incubation for 7 days, the neuronal differentiation of NSPCs and synapse function of differentiated neurons were identified by immunocytochemistry for lineage specific markers. RESULTS: Compared with the only PAH film, the PSS-ending film (neuron-rich model) was shown to significantly promote differentiation of NSPCs into neurons (more than 50%), form a neuronal network structure; and differentiated neurons exhibiting functional synaptic activity. CONCLUSION: This study shows that the PEMs provided an easily alternative approach to modify the surface properties; and might be a method to obtain a neuron-rich model for the biological/pharmaceutical applications.

Concentration-Emission Matrix (CEM) Spectroscopy Combined with GA-SVM: An Analytical Method to Recognize Oil Species in Marine.

The establishment and development of a set of methods of oil accurate recognition in a different environment are of great significance to the effective management of oil spill pollution. In this work, the concentration-emission matrix (CEM) is formed by introducing the concentration dimension. The principal component analysis (PCA) is applied to extract the spectral feature. The classification methods, such as Probabilistic Neural Networks (PNNs) and Genic Algorithm optimization Support Vector Machine (SVM) parameters (GA-SVM), are used for oil identification and the recognition accuracies of the two classification methods are compared. The results show that the GA-SVM combined with PCA has the highest recognition accuracy for different oils. The proposed approach has great potential in rapid and accurate oil source identification.

Keystrokes, Mouse Clicks, and Gazing at the Computer: How Physician Interaction with the EHR Affects Patient Participation.

BACKGROUND: Evidence is mixed regarding how physicians' use of the electronic health record (EHR) affects communication in medical encounters. OBJECTIVE: To investigate whether the different ways physicians interact with the computer (mouse clicks, key strokes, and gaze) vary in their effects on patient participation in the consultation, physicians' efforts to facilitate patient involvement, and silence. DESIGN: Cross-sectional, observational study of video and event recordings of primary care and specialty consultations. PARTICIPANTS: Thirty-two physicians and 217 patients. MAIN MEASURES: Predictor variables included measures of physician interaction with the EHR (mouse clicks, key strokes, gaze). Outcome measures included active patient participation (asking questions, stating preferences, expressing concerns), physician facilitation of patient involvement (partnership-building and supportive talk), and silence. KEY RESULTS: Patients were less active participants in consultations in which physicians engaged in more keyboard activity (b = -0.002, SE = 0.001, p = 0.02). More physician gaze at the computer was associated with more silence in the encounter (b = 0.21, SE = 0.09, p = 0.02). Physicians' facilitative communication, which predicted more active patient participation (b = 0.65, SE = 0.14, p < 0.001), was not related to EHR activity measures. CONCLUSIONS: Patients may be more reluctant to actively participate in medical encounters when physicians are more physically engaged with the computer (e.g., keyboard activity) than when their behavior is less demonstrative (e.g., gazing at EHR). Using easy to deploy communication tactics (e.g., asking about a patient's thoughts and concerns, social conversation) while working on the computer can help physicians engage patients as well as maintain conversational flow.

Physician activity during outpatient visits and subjective workload.

We describe methods for capturing and analyzing EHR use and clinical workflow of physicians during outpatient encounters and relating activity to physicians' self-reported workload. We collected temporally-resolved activity data including audio, video, EHR activity, and eye-gaze along with post-visit assessments of workload. These data are then analyzed through a combination of manual content analysis and computational techniques to temporally align streams, providing a range of process measures of EHR usage, clinical workflow, and physician-patient communication. Data was collected from primary care and specialty clinics at the Veterans Administration San Diego Healthcare System and UCSD Health, who use Electronic Health Record (EHR) platforms, CPRS and Epic, respectively. Grouping visit activity by physician, site, specialty, and patient status enables rank-ordering activity factors by their correlation to physicians' subjective work-load as captured by NASA Task Load Index survey. We developed a coding scheme that enabled us to compare timing studies between CPRS and Epic and extract patient and visit complexity profiles. We identified similar patterns of EHR use and navigation at the 2 sites despite differences in functions, user interfaces and consequent coded representations. Both sites displayed similar proportions of EHR function use and navigation, and distribution of visit length, proportion of time physicians attended to EHRs (gaze), and subjective work-load as measured by the task load survey. We found that visit activity was highly variable across individual physicians, and the observed activity metrics ranged widely as correlates to subjective workload. We discuss implications of our study for methodology, clinical workflow and EHR redesign.

Mesoporous carbon nanomaterials induced pulmonary surfactant inhibition, cytotoxicity, inflammation and lung fibrosis.

Environmental exposure and health risk upon engineered nanomaterials are increasingly concerned. The family of mesoporous carbon nanomaterials (MCNs) is a rising star in nanotechnology for multidisciplinary research with versatile applications in electronics, energy and gas storage, and biomedicine. Meanwhile, there is mounting concern on their environmental health risks due to the growing production and usage of MCNs. The lung is the primary site for particle invasion under environmental exposure to nanomaterials. Here, we studied the comprehensive toxicological profile of MCNs in the lung under the scenario of moderate environmental exposure. It was found that at a low concentration of 10µg/mL MCNs induced biophysical inhibition of natural pulmonary surfactant. Moreover, MCNs at similar concentrations reduced viability of J774A.1 macrophages and lung epithelial A549 cells. Incubating with nature pulmonary surfactant effectively reduced the cytotoxicity of MCNs. Regarding the pro-inflammatory responses, MCNs activated macrophages in vitro, and stimulated lung inflammation in mice after inhalation exposure, associated with lung fibrosis. Moreover, we found that the size of MCNs played a significant role in regulating cytotoxicity and pro-inflammatory potential of this nanomaterial. In general, larger MCNs induced more pronounced cytotoxic and pro-inflammatory effects than their smaller counterparts. Our results provided valuable information on the toxicological profile and environmental health risks of MCNs, and suggested that fine-tuning the size of MCNs could be a practical precautionary design strategy to increase safety and biocompatibility of this nanomaterial.

Study on Three-Dimensional Fluorescence Spectral Characteristics of Heterocyclic Pesticides in Different Environmental Conditions.

The impact analysis of different environments on the fluorescence emission spectrum of pesticides is critical in detecting the concentration of pesticides. In this paper, three kinds of pesticides, carbendazim, carbaryl and fuberidazole, were selected as the research objects. Under different environment, such as different pH values and the presence of different common anion or cation, three-dimensional fluorescence spectral emission (EEM) characteristic of pesticides were analyzed. The experimental results showed that the primary fluorescence peaks for three kinds of pesticides were at λex/λem=280/300, 310/340 and 280/335 nm (respectively); Carbendazim and fuberidazole had a secondary peak at 245/305 nm (PeakB) and 250/340 nm (PeakB). We can come to the conclusion that with the change of pH value, the characteristic of fluorescence emission of carbendazim and fuberidazole is similar. We can find that the fluorescence intensities of carbendazim and fuberidazole were enhanced with the declining of the solution acidity or alkalinity and the fluorescence intensity of carbaryl had not changed with the declining of the solution acidity, but it increased with the declining of the solution alkalinity; the fluorescence emission spectra of the three kinds of pesticides had good fluorescence characteristics with the scope of the pH varying from 6.16 to 7.4. Twelve common ions in water (CO2-3，SO2-4，NO-3，Cl-，HPO2-4，HCO-3，Mg2+，Zn2+，NH+4，Na+，Ca2+，K+) had no significant effect on fluorescence emission characteristics of carbendazim and fuberidazole. The fluorescence intensities were seriously influenced by Fe3+ and Cu2+. The results showed that the pesticides fluorescence intensities were decreased with the ion concentration increasing. It was necessary to consider the quenching effects on pesticides of Fe3+ and Cu2+for the analytic results. The obtained results provided the basic research for improving the accuracy of the heterocyclic pesticides measurement in water.