Quaternized carbon dots with enhanced antimicrobial ability towards Gram-negative bacteria for the treatment of acute peritonitis caused by E. coli.

Infections caused by Gram-negative bacteria still pose a clinical challenge. Although nanomaterials have been developed for antibacterial treatments, a systematic evaluation of the mechanisms and intervention models of antibacterial materials toward Gram-negative bacteria is still lacking. Herein, antibacterial quaternized carbon dots (QCDs) were synthesized via a one-step melting method using anhydrous citric acid and diallyl dimethyl ammonium chloride (DDA). The QCDs exhibited effective broad-spectrum antibacterial activity and enhanced inhibitory ability towards Gram-negative bacteria. The antibacterial mechanism of the QCDs with respect to Gram-negative bacteria was investigated through the characterization of bacterial morphology changes, the absorption modes of the QCDs on bacteria, and the potential generation of reactive oxygen species by the QCDs. The QCDs showed low toxicity in different cells, and did not cause hemolysis. The QCDs were administered via intraperitoneal injection to treat acute peritonitis in mice infected with E. coli. Routine blood examination, magnetic resonance imaging, and pathological analysis were undertaken and it was found that, similar to the positive control group treated with gentamicin sulfate, the QCDs exhibited a therapeutic effect that eliminated infection and inflammation. This study explores a controllable synthetic strategy for the synthesis of active carbon dots with antibacterial activity, a material that is a promising candidate for new treatments of Gram-negative bacterial infections.

A Study of the Mechanisms and Characteristics of Fluorescence Enhancement for the Detection of Formononetin and Ononin.

In this work, the origins for the spectral difference between two isoflavones, formononetin (F) and ononin (FG), are revealed via a comparison study of the fluorescence molecular structure. The fluorescence enhancement of FG in hot alkaline conditions is reported for the first time. For F, there is almost no fluorescence under acidic conditions, but when the pH is >4.8, its fluorescence begins to increase due to the deprotonation of 7-OH. Under a pH between 9.3 and 12.0, the anionic form of F produces a strong and stable fluorescence. The fluorescence quantum yield (Yf) of F is measured to be 0.042. FG shows only weak fluorescence in aqueous solutions under a wide range of pH until it is placed in hot alkaline solutions, which is attributed to the cleavage reaction of the γ-pyrone ring in FG. The Yf of FG is determined to be 0.020. Based on the fluorescence sensitization methods of F and FG, the quantitative analysis and detection of two substances can be realized. The limit of the detections for F and FG are 2.60 ng·mL-1 and 9.30 ng·mL-1, respectively. The linear detection ranges of F and FG are 11.7~1860 ng·mL-1 and 14.6~2920 ng·mL-1, respectively. Although the structural relationship between F and FG is glycoside and aglycone, under hot alkaline conditions, the final products after the cleavage and hydrolysis reactions are essentially different. The different fluorescence characteristics between F and FG pave a way for further identification and a quantitative analysis of the corresponding components in Chinese herbal medicine.

Mass-Transfer Simulation of Salicylic Acid on Weakly Polar Hyper-cross-linked Resin XDA-200 with Coadsorption of Sodium Ion.

The mass-transfer process of salicylic acid on hyper-cross-linked resin XDA-200 was experimentally and theoretically studied. Undissociated salicylic acid was found to be the favorable form for salicylic acid adsorption on the resin. A pH-dependent adsorption isotherm model established in this paper could well fit the adsorption isotherm data at different pH values. Surface diffusion is the main mass-transfer mode for salicylic acid in resin particles. The salicylate anions and Na+ coadsorbed on the resin. The modified surface diffusion model considering the coadsorption was proposed. The model could satisfactorily fit the concentration decay curves of salicylic acid at different pH values and feed concentrations. NaOH aqueous solution at pH 12 could elute salicylic acid in the fixed bed efficiently. A pH-dependent dynamic adsorption and elution process model considering axial diffusion, external mass transfer, surface diffusion, pH-dependent adsorption equilibrium, as well as coadsorption of salicylate anions and Na+ was established. The model could well predict the breakthrough and elution curves at different feed concentrations. The research carried out in this paper has reference significance for optimizing the separation process of salicylic acid and its analogues.

Investigation of Pyrolysis and Mild Oxidation Characteristics of Tar-Rich Coal via Thermogravimetric Experiments.

Tar-rich coal has the potential to substitute the supply of oil-gas resources, which is abundant in China. The effective conversion of tar-rich coal into oil-gas products can promote coal utilization, reduce resource wastage, alleviate environmental pollution, and benefit carbon neutrality. Nevertheless, less work, if any, has been performed on the pyrolysis and mild oxidation behaviors of tar-rich coal in Northwestern China. The influences of limited oxygen addition and an extremely low heating rate on the micromorphology of the residual semi-coke are yet to be fully understood. Here, an experimental study on the pyrolysis and mild oxidation characteristics of tar-rich coal was conducted by the thermogravimetric analysis method, with further elucidation of the physical-chemical properties of the residual semi-coke. Experimental results show that an increase in the ultimate temperature of pyrolysis leads to a decline in the residue mass, while the mass loss from 500 to 550 °C presents the maximum elevation. Volatile matter is inclined to discharge from a certain direction, and the pores formed in various directions hold different possibilities. The organic components undergo both pyrolysis and slow oxidation with limited oxygen in the heating medium. Compared with an inert atmosphere, the mass loss under conditions of a small amount of O2 is brought forward but prolonged. Compared with a N2 atmosphere, the oxidation reactions of tar-rich coal are weakened in the presence of CO2. A large decrease in the heating rate exerts an unfavorable effect on the production of total volatiles. An extremely low heating rate possibly brings about a change in the mechanism of chemical bond cracking during pyrolysis. More pores can be yielded in tar-rich coal with an increase in the heating rate, and the morphology of the residual semi-coke after pyrolysis is susceptible to the heating rate. The present study offers an improved understanding of the pyrolysis characteristics of tar-rich coal as well as insights into the efficient utilization of tar-rich coal.

Adsorption separation of guanosine 5'-Monophosphate and cytidine 5'-Monophosphate by mixed-mode Resin HD-1: Experimental study and mathematical modeling.

The preparative separation of guanosine 5'-monophosphate (GMP) and cytidine 5'-monophosphate (CMP) on mixed-mode resin HD-1 was experimentally and theoretically investigated. The adsorption mechanisms of the two nucleotides were elucidated by analyzing adsorption equilibria and kinetics at different pH values. The adsorption dynamics of GMP and CMP in a fixed bed packed with resin HD-1 were studied. All nucleotide monovalent cations, zwitterions, and monovalent anions were adsorbed by the resin. Further, a general adsorption isotherm model was developed by considering the adsorption of different nucleotide species and the dissociation equilibrium behaviors of resin ligands. The model fit the adsorption isotherm data of GMP and CMP well. A modified liquid-film linear driving force model with the combined physical adsorption of nucleotides in different dissociation states and ion exchange of Na+ was established. The dissociation equilibria of resin ligands and nucleotides were considered. The model satisfactorily predicted the adsorption kinetic data at different pH values. The values of the efficient diffusion coefficients for GMP and CMP were not significantly influenced by the solution pH. A modified transport-diffusion model with pH gradient elution was proposed. The model accurately predicted the elution chromatographic peaks of GMP and CMP, as well as the pH at the outlet of the fixed bed packed with resin HD-1.

Fluorescence, Absorption, Chromatography and Structural Transformation of Chelerythrine and Ethoxychelerythrine in Protic Solvents: A Comparative Study.

Chelerythrine (CH) and ethoxychelerythrine (ECH) are chemical reference substances for quality control of Chinese herbal medicines, and ECH is the dihydrogen derivative of CH. In this study, their fluorescence and absorption spectra, as well as their structural changes in different protic solvents were compared. It was observed that their emission fluorescence spectra in methanol were almost the same (both emitted at 400 nm), which may be attributed to the nucleophilic and exchange reactions of CH and ECH with methanol molecules with the common product of 6-methoxy-5,6-dihydrochelerythrine (MCH). When diluted with water, MCH was converted into CH, which mainly existed in the form of positively charged CH+ under acidic and near-neutral conditions with the fluorescence emission at 550 nm. With the increase of pH value of the aqueous solution, CH+ converted to 6-hydroxy-5,6-dihydrochelerythrine (CHOH) with the fluorescence emission at 410 nm. The fluorescence quantum yields of MCH and CHOH were 0.13 and 0.15, respectively, and both the fluorescence intensities were much stronger than that of CH+. It is concluded that CH and ECH can substitute each other in the same protic solvent, which was further verified by high-performance liquid chromatography. This study will help in the investigation of structural changes of benzophenanthridine alkaloids and will provide the possibility for the mutual substitution of standard substances in relevant drug testing.

Malicious traffic detection combined deep neural network with hierarchical attention mechanism.

Given the gradual intensification of the current network security situation, malicious attack traffic is flooding the entire network environment, and the current malicious traffic detection model is insufficient in detection efficiency and detection performance. This paper proposes a data processing method that divides the flow data into data flow segments so that the model can improve the throughput per unit time to meet its detection efficiency. For this kind of data, a malicious traffic detection model with a hierarchical attention mechanism is also proposed and named HAGRU (Hierarchical Attention Gated Recurrent Unit). By fusing the feature information of the three hierarchies, the detection ability of the model is improved. An attention mechanism is introduced to focus on malicious flows in the data flow segment, which can reasonably utilize limited computing resources. Finally, compare the proposed model with the current state of the method on the datasets. The experimental results show that: the novel model performs well in different evaluation indicators (detection rate, false-positive rate, F-score), and it can improve the performance of category recognition with fewer samples when the data is unbalanced. At the same time, the training of the novel model on larger datasets will enhance the generalization ability and reduce the false alarm rate. The proposed model not only improves the performance of malicious traffic detection but also provides a new research method for improving the efficiency of model detection.

MBD2 Mediates Septic AKI through Activation of PKCη/p38MAPK and the ERK1/2 Axis.

Our previous study demonstrated that the methyl-CpG-binding domain protein 2 (MBD2) mediates vancomycin (VAN)-induced acute kidney injury (AKI). However, the role and regulation of MBD2 in septic AKI are unknown. Herein, MBD2 was induced by lipopolysaccharide (LPS) in Boston University mouse proximal tubules (BUMPTs) and mice. For both in vitro and in vivo experiments, we showed that inhibition of MBD2 by MBD2 small interfering RNA (siRNA) and MBD2-knockout (KO) substantially improved the survival rate and attenuated both LPS and cecal ligation and puncture (CLP)-induced AKI, renal cell apoptosis, and inflammatory factor production. Global genetic expression analyses and in vitro experiments suggest that the expression of protein kinase C eta (PKCη), caused by LPS, is markedly suppressed in MBD2-KO mice and MBD2 siRNA, respectively. Mechanistically, chromatin immunoprecipitation (ChIP) analysis indicates that MBD2 directly binds to promoter region CpG islands of PKCη via suppression of promoter methylation. Furthermore, PKCη siRNA improves the survival rate and attenuates LPS-induced BUMPT cell apoptosis and inflammatory factor production via inactivation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK)1/2, which were further verified by PKCη siRNA treatment in CLP-induced AKI. Finally, MBD2-KO mice exhibited CLP-induced renal cell apoptosis and inflammatory factor production by inactivation of PKCη/p38MAPK and ERK1/2 signaling. Taken together, the data indicate that MBD2 mediates septic-induced AKI through the activation of PKCη/p38MAPK and the ERK1/2 axis. MBD2 represents a potential target for treatment of septic AKI.

Multiomics integrative analysis for gene signatures and prognostic values of m6A regulators in pancreatic adenocarcinoma: a retrospective study in The Cancer Genome Atlas project.

N6-methyladenosine(m6A) is the most abundant post-transcriptional RNA modification in eukaryotes. However, little is known about its role in pancreatic adenocarcinoma (PAAD). The aim of our study was to identify gene signatures and prognostic values of m6A regulators in PAAD. Patients from 3 different datasets with complete genomic and transcriptomic sequencing data were enrolled. Survival analysis for different gene alterations was performed using log-rank tests and Cox regression model. The association between alteration of m6A regulators and clinicopathological characteristics was examined using chi-square test. Results showed a high frequency of copy number alterations (CNAs) of m6A regulatory genes in PAAD patients, but somatic mutations were rarely happened. CNAs and mutations of m6A regulatory genes was associated with patient's gender, pathologic stage and resected tumor size. Patients with "gain of function" for m6A "reader" genes combined with copy number loss of "writers" or "erasers" had worse overall survival (OS) compared with other patterns. Moreover, copy number gain of m6A "reader" gene insulin growth factor 2 binding protein 2 (IGF2BP2) was an independent risk factor for OS (HR = 2.392, 95%CI: 1.392-4.112, p<0.001) and disease-free survival (DFS) (HR = 2.400, 95%CI: 1.236-4.659, p=0.010). Gene Set Enrichment Analysis (GSEA) indicated that IGF2BP2 was correlated with multiple biological processes associated with cancer, of which the most significant processes were relevant to cancer cell cycle, cell immortalization and tumor immunity. To sum up, a significant relationship was found between m6A genomic alterations and worse clinical outcomes. These innovative findings are expected to guide further research on the mechanism of m6A in PAAD.

Effect of long non-coding RNA long stress-induced noncoding transcript 5 on erlotinib resistance to lung cancer cells and the underlying mechanisms. / é•¿é“¾éžç¼–ç RNAåº”æ¿€è¯±å¯¼é•¿é“¾éžç¼–ç è½¬å½•æœ¬5å¯¹è‚ºç™Œç»†èƒžåŽ„æ´›æ›¿å°¼æ•æ„Ÿæ€§çš„å½±å“åŠå ¶æœºåˆ¶.

OBJECTIVES: To explore the relationship between long non-coding RNA (lncRNA) long stress-induced noncoding transcript 5 (LSINCT5) and erotinib resistance to lung cancer cells and the potential mechanisms. METHODS: Human lung cancer cell line A549, H520, H358, H1299, SPCA1, and PC9 were collected and cultured. Epidermal growth factor receptor (EGFR) mutant lung cancer cell line PC9 was divided into a control group, a resistance group, a interference group I and II. The control group was treated with dimethylsulfoxide (DMSO) for 10 weeks and then was transfected with control target sequence expression vector. The resistant group was treated with erlotinib at gradient concentration (0.1, 0.2, 0.4, 0.8, and 1.6 µmol/L, respectively) for 2 weeks and then transfected with control target sequence expression vector. Interference group I and II were treated with erlotinib at gradient concentration (0.1, 0.2, 0.4, 0.8, and 1.6 µmol/L, respectively) for 2 weeks and then transfected with the shRNA targeting expression vectors 1 and 2. 50% inhibitory concentration (IC50) of erlotinib was detected by cell counting kit-8 (CCK-8) assay. The mRNA expressions of LSINCT5, phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) were measured by real-time PCR. The protein levels of PI3K, Akt, and phospho-Akt (p-Akt) were detected by Western blotting. The divergences of Akt and IgG binding to LSINCT5 were detected by RNA immunoprecipitation (RNA-IP) experiment. RESULTS: The expression of LSINCT5 in PC9 cells was significantly higher than that in other lung cancer cell lines (all P<0.05). Compared with the control group, the IC50 of erotinib and the expression of LSINCT5, PI3K, and Akt mRNA and protein in the resistance group were significantly higher (all P<0.05), and the IC50 of erotinib and the expression of LSINCT5, Akt, and p-Akt in the interference group I and II were significantly lower (all P<0.05). Compared with IgG, LSINCT5 binding to Akt was increased significantly (P<0.05). CONCLUSIONS: The expression of LSINCT5 is high in the erlotinib-resistant cells. Interference with LSINCT5 may inhibit the expression and activity of Akt and promote the cell sensitivity to erlotinib.

Author Correction: Directed self-assembly of herbal small molecules into sustained release hydrogels for treating neural inflammation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

TMT-based proteomics analysis reveals the protective effects of Xuefu Zhuyu decoction in a rat model of traumatic brain injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Xuefu Zhuyu decoction (XFZYD) is a traditional Chinese herbal prescription. It is effective in treating traumatic brain injury (TBI). However, the underlying molecular mechanisms remain unclear. AIM OF THE STUDY: This study aimed to reveal the possible mechanisms of XFZYD in treating acute TBI through proteomics clues. MATERIALS AND METHODS: Controlled Cortical Impact (CCI) rats were given gavage administration of XFZYD (9 g/kg/d) or distilled water (equal volume) for three days. The Modified Neurological Severity Score (mNSS), brain water content, HE staining, Nissl staining and immunohistochemistry were performed to assess the effects of XFZYD for TBI treatment. Additionally, tandem mass tag-based (TMT) quantitative proteomics technology was applied to detect proteins of brain cortex. Bioinformatics analysis including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Protein-protein interaction (PPI) networks were used to analyze differentially expressed proteins (DEPs). Bioinformatics Analysis Tool for Molecular mechanism of TCM (BATMAN-TCM) was conducted to anchor diseases and pathways. Besides, western blotting and immunofluorescence were exerted to verify related proteins. RESULTS: XFZYD improved neurologic functions, reduced encephaledema and ameliorated cell morphology around the injured area in CCI rats. A total of 6099 proteins were identified with false discovery rate (FDR) < 1%. Overlapping DEPs (105 DEPs) were identified (295 DEPs and 804 DEPs in CCI/Sham or XFZYD/CCI group, respectively). Of these DEPs, 17 were regulated by XFZYD. Bioinformatics analysis showed that the 17 DEPs were predominantly related to platelet activation and PI3K-Akt signaling pathway. Next, PLG and CD34 were verified with molecular biotechnology. CONCLUSIONS: XFZYD exerts therapeutic effects through multi-pathways regulation in the treatment of TBI. This work may provide proteomics clues for the continuation of research on TBI treatment with XFZYD.

[Tumor infiltrating T lymphocyte components in malignant pleural effusion of lung adenocarcinoma and their killing activities to autologous tumor cells].

OBJECTIVE: To analyze the components of tumor infiltrating T lymphocyte (TIL) cells in malignant pleural effusion of lung adenocarcinoma, and evaluate their killing activities to autologous tumor cells. 
 Methods: Malignant pleural effusions were collected from 17 patients with lung adenocarcinoma. Mononuclear cells were isolated by Ficoll density gradient centrifugation and flow cytometer was used to analyze TIL cell components. TIL and tumor cells were separated through adherent culture. The tumor cells were identified via intramuscular injection of adherent cells into nude mice and the killing effect of cultured lymphocytes on autologous tumor cells was studied.
 Results: Of the TIL in malignant pleural effusions, T cells accounted for 60.6%-79.3%, while T helper cells were significantly higher than T killer cells (36.63%±1.90% vs 24.64%±2.32%, P<0.001). There were also natural killer (NK) cells and NK T cells in the effusions. Tumor cells were successfully isolated and cultured. The killing activity of cultured TIL to autologous tumor cells was 39.14%±12.04%, and the killing activity of TIL with high proliferation rate to autologous tumor cells was higher than that of low proliferation group (50.51%±3.80% vs 29.04%±5.77%, P<0.001).
 Conclusion: T lymphocytes are the major components of TIL in malignant pleural effusions derived from lung adenocarcinoma, and T helper cells are more than T killer cells. The killing activity of TIL with strong proliferation ability to autologous tumor cells is higher than that of TIL with weak proliferation ability. Therefore, cells from malignant pleural effusions could be used for cellular immunotherapy against tumor.

Directed self-assembly of herbal small molecules into sustained release hydrogels for treating neural inflammation.

Self-assembling natural drug hydrogels formed without structural modification and able to act as carriers are of interest for biomedical applications. A lack of knowledge about natural drug gels limits there current application. Here, we report on rhein, a herbal natural product, which is directly self-assembled into hydrogels through noncovalent interactions. This hydrogel shows excellent stability, sustained release and reversible stimuli-responses. The hydrogel consists of a three-dimensional nanofiber network that prevents premature degradation. Moreover, it easily enters cells and binds to toll-like receptor 4. This enables rhein hydrogels to significantly dephosphorylate IκBα, inhibiting the nuclear translocation of p65 at the NFκB signalling pathway in lipopolysaccharide-induced BV2 microglia. Subsequently, rhein hydrogels alleviate neuroinflammation with a long-lasting effect and little cytotoxicity compared to the equivalent free-drug in vitro. This study highlights a direct self-assembly hydrogel from natural small molecule as a promising neuroinflammatory therapy.