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2.
Thorac Cardiovasc Surg ; 72(3): 217-226, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37532228

ABSTRACT

OBJECTIVE: The aim of this study was to explore the effect of different organ metastasis on the prognosis of non-small cell lung cancer (NSCLC). METHODS: Patients with distant metastatic NSCLC were selected from Surveillance, Epidemiology, and End Results database during 2016 to 2019. The incidence of different organ metastasis and their association with clinicopathological factors were explored. Overall survival (OS) and lung cancer-specific survival (LCSS) for metastatic NSCLC were calculated, and multivariate Cox regression analysis was performed with a nomogram for OS being constructed based on Cox regression. RESULTS: Total 26,210 patients with distant metastatic NSCLC were included in this study. Around 48.9% of the metastatic NSCLC were multiple-organ metastasis and bone was the most commonly involved organ (44.4%). For patients with single-organ metastasis, the prognosis for lung or distant lymph nodes (LNs) metastasis was better than others (with median OS of 15 and 16 months for lung and distant LNs metastasis, respectively), and liver metastasis resulted in the worst prognosis with median OS of 8 months. A nomogram was constructed to visualize Cox regression model, along with the receiver operating characteristic (ROC) curve demonstrated good discrimination for the predictive model with 1- and 2-year area under the curve of ROC of 0.687 and 0.702, respectively. CONCLUSION: The prognosis of NSCLC patients with distant metastasis was poor. Liver metastasis results in the worst prognosis among the single-organ metastasis. The nomogram developed based on the Cox regression model has provided a useful tool to estimate the probability of OS of the metastatic NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Liver Neoplasms , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/therapy , Lung Neoplasms/pathology , Incidence , Treatment Outcome , Prognosis , Lymphatic Metastasis , Liver Neoplasms/secondary
3.
Cell Rep Med ; 4(8): 101144, 2023 08 15.
Article in English | MEDLINE | ID: mdl-37586322

ABSTRACT

Non-alcoholic fatty liver disease (NAFLD) is an emerging risk factor of hepatocellular carcinoma (HCC). However, the mechanism and target therapy of NAFLD-HCC are still unclear. Here, we identify that the N6-methyladenosine (m6A) methyltransferase METTL3 promotes NAFLD-HCC. Hepatocyte-specific Mettl3 knockin exacerbated NAFLD-HCC formation, while Mettl3 knockout exerted the opposite effect in mice. Single-cell RNA sequencing revealed that METTL3 suppressed antitumor immune response by reducing granzyme B (GZMB+) and interferon gamma-positive (IFN-γ+) CD8+ T cell infiltration, thereby facilitating immune escape. Mechanistically, METTL3 mediates sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) mRNA m6A to promote its translation, leading to the activation of cholesterol biosynthesis. This enhanced secretion of cholesterol and cholesteryl esters that impair CD8+ T cell function in the tumor microenvironment. Targeting METTL3 by single-guide RNA, nanoparticle small interfering RNA (siRNA), or pharmacological inhibitor (STM2457) in combination with anti-programmed cell death protein 1 (PD-1) synergized to reinvigorate cytotoxic CD8+ T cells and mediate tumor regression. Together, METTL3 is a therapeutic target in NAFLD-HCC, especially in conjunction with immune checkpoint blockade (ICB) therapy.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Methyltransferases , Non-alcoholic Fatty Liver Disease , Animals , Mice , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/genetics , CD8-Positive T-Lymphocytes , Immunotherapy , Interferon-gamma/metabolism , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Methyltransferases/genetics , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/therapy , Non-alcoholic Fatty Liver Disease/complications , Tumor Microenvironment
4.
Sci Rep ; 13(1): 10689, 2023 Jul 01.
Article in English | MEDLINE | ID: mdl-37393321

ABSTRACT

High-story residential structures and off-site prefabrication have been dominant choices in the construction industry. There is a substantial quantity of greenhouse gas (GHG) emissions produced by the construction industry. In fact, the construction industry is responsible for 30 percent of all GHG emissions. In this study, we analyse the differences between the conventional technique of building and the off-site prefabricating construction method. First, we evaluate the emissions emitted from key processes during the off-site prefabricating construction. In addition, we analyse the qualitative and quantitative differences between two prefabrication structural systems, namely concrete and steel, which are the two most common structural systems utilised in residential construction projects in China. We examine and analyse four different case studies in order to exemplify the proposed methodology and offer managerial insights.


Subject(s)
Construction Industry , Greenhouse Gases , China , Problem Solving , Records
5.
Nat Microbiol ; 8(8): 1534-1548, 2023 08.
Article in English | MEDLINE | ID: mdl-37386075

ABSTRACT

Non-alcoholic steatohepatitis (NASH) is the severe form of non-alcoholic fatty liver disease, and is characterized by liver inflammation and fat accumulation. Dietary interventions, such as fibre, have been shown to alleviate this metabolic disorder in mice via the gut microbiota. Here, we investigated the mechanistic role of the gut microbiota in ameliorating NASH via dietary fibre in mice. Soluble fibre inulin was found to be more effective than insoluble fibre cellulose to suppress NASH progression in mice, as shown by reduced hepatic steatosis, necro-inflammation, ballooning and fibrosis. We employed stable isotope probing to trace the incorporation of 13C-inulin into gut bacterial genomes and metabolites during NASH progression. Shotgun metagenome sequencing revealed that the commensal Parabacteroides distasonis was enriched by 13C-inulin. Integration of 13C-inulin metagenomes and metabolomes suggested that P. distasonis used inulin to produce pentadecanoic acid, an odd-chain fatty acid, which was confirmed in vitro and in germ-free mice. P. distasonis or pentadecanoic acid was protective against NASH in mice. Mechanistically, inulin, P. distasonis or pentadecanoic acid restored gut barrier function in NASH models, which reduced serum lipopolysaccharide and liver pro-inflammatory cytokine expression. Overall this shows that gut microbiota members can use dietary fibre to generate beneficial metabolites to suppress metabolic disease.


Subject(s)
Non-alcoholic Fatty Liver Disease , Animals , Mice , Non-alcoholic Fatty Liver Disease/prevention & control , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/microbiology , Inulin , Fatty Acids/metabolism , Inflammation , Dietary Fiber
6.
J Agric Food Chem ; 71(14): 5516-5524, 2023 Apr 12.
Article in English | MEDLINE | ID: mdl-37000156

ABSTRACT

Spodoptera frugiperda is a major migratory agricultural pest, which seriously impedes agricultural production around the world. To discover potent compounds against S. frugiperda, a number of novel isoxazoline derivatives were designed and synthesized and created on account of the identified lead compound F32 (4-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-2-methyl-N-(3-propionamidophenyl)benzamide). Based on the three-dimensional quantitative structure-activity relationship of those compounds, the compound G22 (N-(4-acetamidophenyl)-4-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-2-methylbenzamide) was developed. A bioassay showed that G22 is highly lethal to S. frugiperda (LC50 = 1.57 mg/L), a more effective control than insecticides fipronil (LC50 = 78.8 mg/L) and chlorantraniliprole (LC50 = 1.60 mg/L). Field trials were also implemented to identify candidate agents. Furthermore, from the insect γ-aminobutyric acid (GABA) enzyme-linked immunosorbent assay, it is obvious that G22 could up-regulate the expression of GABA of insects, which showed a similar result to fipronil. The analysis of molecular docking exhibited that the hydrophobic effect and hydrogen bonds play key roles in the combination between G22 with GABA receptors. This study provides a potent isoxazoline candidate compound for the S. frugiperda control.


Subject(s)
Insecticides , Animals , Diamide/chemistry , Insecta , Insecticides/chemistry , Molecular Docking Simulation , Spodoptera , Isoxazoles/chemistry
7.
Lung ; 201(2): 225-234, 2023 04.
Article in English | MEDLINE | ID: mdl-36928143

ABSTRACT

PURPOSE: Hyperoxia-induced apoptosis in alveolar epithelial type II cells (AECIIs) plays a critical role in the development of bronchopulmonary dysplasia (BPD). Melatonin has been shown to improve BPD. However, the protective effect of melatonin on hyperoxia-induced apoptosis in AECIIs and the precise mechanisms involved remain unclear. METHODS: Human alveolar epithelial type II A549 cells were treated with hyperoxia as an in vitro model to investigate the antiapoptotic mechanism of melatonin. CCK-8 assays were performed to investigate the viability of A549 cells. Hoechst 33,258 staining was carried out to quantify apoptosis in A549 cells. The protein expression levels of E26 oncogene homolog 1 (ETS1), Bcl-2, Bax, Bim, Wnt, ß-catenin, AKT and phosphorylated AKT were measured by western blotting. LY294002, SC79 and the downregulation of ETS1, melatonin receptor 1 (MT1) and MT2 with specific siRNAs were used to investigate the role of the PI3K/AKT pathway, ETS1, MT1 and MT2 in hyperoxia-induced apoptosis in A549 cells. RESULTS: Melatonin prevented hyperoxia-induced apoptosis in A549 cells, and the upregulation of E26 oncogene homolog 1 (ETS1) contributed to the antiapoptotic effect of melatonin. Melatonin activated the PI3K/AKT axis, which led to ETS1 upregulation and inhibited apoptosis in hyperoxia-exposed A549 cells. Furthermore, melatonin-induced activation of the PI3K/AKT axis, upregulation of ETS1 and inhibition of apoptosis were reversed by melatonin receptor 2 (MT2) siRNA in hyperoxia-exposed A549 cells. CONCLUSION: Melatonin prevents hyperoxia-induced apoptosis by activating the MT2/PI3K/AKT/ETS1 axis in alveolar epithelial cells.


Subject(s)
Bronchopulmonary Dysplasia , Hyperoxia , Melatonin , Infant, Newborn , Humans , Alveolar Epithelial Cells , Hyperoxia/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Melatonin/pharmacology , Melatonin/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Phosphatidylinositol 3-Kinases/pharmacology , Receptors, Melatonin/metabolism , Signal Transduction , Apoptosis , Bronchopulmonary Dysplasia/metabolism , Epithelial Cells/metabolism , Proto-Oncogene Protein c-ets-1
8.
J Healthc Eng ; 2022: 3409693, 2022.
Article in English | MEDLINE | ID: mdl-35388335

ABSTRACT

Objective: To investigate the risk factors associated with reflux esophagitis in patients undergoing esophageal cancer surgery and to provide reference for the prevention and treatment of reflux esophagitis. Methods: In the manner retrospective study, the data of 300 patients with esophageal cancer who received the surgical treatment in our hospital (January 2018-December 2020) were retrospectively reviewed. The 300 patients were divided into the occurrence group (n = 45) and nonoccurrence group (n = 255) depending on whether they had reflux esophagitis after surgery. The social demographic data and clinical data of the patients in the two groups were collected. These data were classified into the personal factors and surgical factors. The single-factor analysis method was adopted to analyze the effects of the personal and surgical factors on reflux esophagitis. The factors with statistically significant differences in the single-factor analysis were analyzed by logistic regression to verify the factors were the risk factors associated with reflux esophagitis in patients undergoing esophageal cancer surgery. Results: The differences in the bodyweight, body mass index (BMI), length of the resected esophagus, surgical approach, intraoperative blood loss, gastrointestinal decompression volume, and surgery time between the two groups were of statistical significance (P < 0.05). After being tested by the logistics multivariate analysis, length of the resected esophagus, whole stomach reconstruction, intraoperative blood loss, and surgery time were identified as the risk factors associated with reflux esophagitis in patients undergoing esophageal cancer surgery. Conclusion: The length of the resected esophagus, whole stomach reconstruction, intraoperative blood loss, and surgery time were the risk factors associated with reflux esophagitis in patients undergoing esophageal cancer surgery. It is necessary to choose the appropriate surgical approach according to the patients' conditions in practice and to strengthen the prevention and treatment of reflux esophagitis.


Subject(s)
Esophageal Neoplasms , Esophagitis, Peptic , Blood Loss, Surgical , Esophageal Neoplasms/surgery , Esophagitis, Peptic/drug therapy , Esophagitis, Peptic/etiology , Humans , Retrospective Studies , Risk Factors
9.
Cell Mol Gastroenterol Hepatol ; 13(1): 257-274, 2022.
Article in English | MEDLINE | ID: mdl-34506952

ABSTRACT

BACKGROUND & AIMS: Hepatic immune microenvironment plays a pivotal role in the development of nonalcoholic steatohepatitis (NASH). However, the role of natural killer (NK) cells, accounting for 10%-20% of liver lymphocytes, in NASH is still unclear. In this study, we aim to investigate the functional significance of NK cells in NASH evolution. METHODS: NASH was induced in mice fed methionine- and choline-deficient diet (MCD), choline-deficient high-fat diet (CD-HFD), or high-fat diet with streptozotocin injection (STAM model). NK cell deficient mice (Nfil3-/-) and neutralization antibody (PK136) were used in this study. RESULTS: Activated liver NK cells were identified with increased expression of NKG2D, CD107a, and interferon-γ but decreased inhibitory NKG2A. With NK cell deficiency Nfil3-/- mice, the absence of NK cells ameliorated both MCD- and CDHF- induced NASH development with significantly decreased hepatic triglycerides, peroxides, alanine aminotransferase, and aspartate aminotransferase compared with Nfil3+/+ mice. Further molecular analysis unveiled suppressed pro-inflammatory cytokines and associated signaling. Mechanistically, NK cells isolated from NASH liver secreted higher levels of pro-inflammatory cytokines (interferon-γ, interleukin 1ß, interleukin 12, CCL4, CCL5, and granulocyte-macrophage colony-stimulating factor), which could activate hepatic JAK-STAT1/3 and nuclear factor kappa B signaling and induce hepatocyte damage evidenced by elevated reactive oxygen species and apoptosis rate. Moreover, neutralization antibody PK136-dependent NK cell depletion can significantly alleviate MCD-induced steatohepatitis with suppressed cytokine levels and JAK-STAT1/3 activity. CONCLUSIONS: NK cells in NASH liver are activated with a more pro-inflammatory cytokine milieu and promote NASH development via cytokine-JAK-STAT1/3 axis. Modulation of NK cells provides a potential therapeutic strategy for NASH.


Subject(s)
Non-alcoholic Fatty Liver Disease , Animals , Diet, High-Fat , Janus Kinases/metabolism , Killer Cells, Natural , Mice , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease/metabolism , STAT Transcription Factors/metabolism , Signal Transduction
10.
Anal Chem ; 92(15): 10402-10411, 2020 08 04.
Article in English | MEDLINE | ID: mdl-32614167

ABSTRACT

Direct interspecies electron transfer (DIET) has been considered as a novel and highly efficient strategy in both natural anaerobic environments and artificial microbial fuel cells. A syntrophic model consisting of Geobacter metallireducens and Geobacter sulfurreducens was studied in this work. We conducted in vivo molecular mapping of the outer surface of the syntrophic community as the interface of nutrients and energy exchange. System for Analysis at the Liquid Vacuum Interface combined with time-of-flight secondary ion mass spectrometry was employed to capture the molecular distribution of syntrophic Geobacter communities in the living and hydrated state. Principal component analysis with selected peaks revealed that syntrophic Geobacter aggregates were well differentiated from other control samples, including syntrophic planktonic cells, pure cultured planktonic cells, and single population biofilms. Our in vivo imaging indicated that a unique molecular surface was formed. Specifically, aromatic amino acids, phosphatidylethanolamine components, and large water clusters were identified as key components that favored the DIET of syntrophic Geobacter aggregates. Moreover, the molecular changes in depths of the Geobacter aggregates were captured using dynamic depth profiling. Our findings shed new light on the interface components supporting electron transfer in syntrophic communities based on in vivo molecular imaging.


Subject(s)
Amino Acids, Aromatic/metabolism , Geobacter/physiology , Mass Spectrometry/methods , Molecular Imaging/methods , Phosphatidylethanolamines/metabolism , Amino Acids, Aromatic/chemistry , Biofilms , Electron Transport , Phosphatidylethanolamines/chemistry , Principal Component Analysis , Water/chemistry , Water/metabolism
11.
BMC Med Genet ; 21(1): 28, 2020 02 10.
Article in English | MEDLINE | ID: mdl-32041551

ABSTRACT

BACKGROUND: This study aimed to explore the diagnostic value of serum miR-101-3p combined with pepsinogen (PG) on early diagnosis of gastric cancer (GC). METHODS: A total of 61 atrophic gastritis (AG) and 86 GC patients, and 50 healthy volunteers were enrolled. The serum expression of miR-101-3p was measured by qRT-PCR. The serum content of carcinoembryonic antigen (CEA) was measured by Electrochemiluminescence immunoassay. The serum contents of PGI and PGII were measured by Enzyme linked immunosorbent assay. The diagnostic value of serum markers on AG and GC was analyzed by receiver operating characteristic (ROC) analysis. RESULTS: The expression of miR-101-3p, the content of PGI and the ratio of PGI/II were significantly decreased, and the content of PGII was significantly increased in AG patients compared with those in normal controls. The changes of the above serum indicators were more obvious in GC patients than those in AG patients. The content of CEA was significantly higher in GC patients than that in AG patients. In addition, the expression of miR-101-3p was negatively associated with the submucosal infiltration in GC patients. MiR-101-3p exhibited high diagnostic value on AG (AUC 0.8493, sensitivity 80.33%, specificity 80%) and GC (AUC 0.8749, sensitivity 72.09%, specificity 86.49%). MiR-101-3p + PGI + PGI/II (AUC 0.856, sensitivity 80.23%, specificity 77.05%) exhibited a high diagnostic value in distinguishing between AG and GC. CONCLUSIONS: MiR-101-3p was a potential diagnostic marker for AG and GC. MiR-101-3p + PGI + PGI/II was effective in distinguishing between AG and GC.


Subject(s)
Early Detection of Cancer , Gastritis, Atrophic/blood , MicroRNAs/blood , Stomach Neoplasms/blood , Adult , Carcinoembryonic Antigen/blood , Diagnosis, Differential , Female , Gastritis, Atrophic/genetics , Gastritis, Atrophic/pathology , Humans , Male , Middle Aged , Pepsinogen A/blood , Stomach Neoplasms/genetics , Stomach Neoplasms/pathology
12.
Biointerphases ; 14(5): 051004, 2019 09 25.
Article in English | MEDLINE | ID: mdl-31554406

ABSTRACT

In situ liquid time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a powerful technique to study surface characterization of living biofilms in hydrated conditions. However, ToF-SIMS data analysis is still a great challenge in complicated bacterial biofilms, because many interference peaks from the medium may result in inaccurate interpretation. In this study, two syntrophic Geobacter populations are investigated using in situ liquid ToF-SIMS to reveal the biofilm surface changes between them due to direct interspecies electron transfer. By comparing spectral principal component analysis (PCA) results of all peaks and selected peaks, the authors find that spectral peak overlay is an effective strategy to reduce the matrix effect in handling complex ToF-SIMS data. Additionally, the spectral PCA results of high intensity and high resolution data obtained from liquid ToF-SIMS are compared. Selected peaks, amino acid peaks, and water cluster peaks spectral PCA produce nice separation among samples in both high intensity and high resolution data sets. However, the high resolution data show better separation between coculture planktonic and coculture aggregates, confirming that the higher mass accuracy is useful in the analysis of microbial samples. In conclusion, the results show that peak selection is critical for acquiring effective microbial information and interpretation of syntrophic Geobacter using spectral data from in situ liquid ToF-SIMS.


Subject(s)
Biofilms/growth & development , Geobacter/physiology , Spectrometry, Mass, Secondary Ion , Amino Acids/metabolism , Electron Transport/physiology , Principal Component Analysis
13.
ACS Appl Mater Interfaces ; 10(33): 28036-28050, 2018 Aug 22.
Article in English | MEDLINE | ID: mdl-30052025

ABSTRACT

It is a huge challenge to achieve highly efficient fire retardance with no mechanical damage to polymers. In our current research, a novel core-shell titanium dioxide@diphenylphosphinic (TiO2@DPP) nanosphere was first synthesized through a hydrothermal reacting process, and applied in simultaneously enhancing the fire retardance and mechanical properties of polycarbonate (PC). The well-designed TiO2@DPP exhibited a significant effect on combustion performance and mechanical reinforcement of PC. At only 0.10 wt % of TiO2@DPP, PC/TiO2@DPP passed the UL-94 V-0 rating, and its oxygen index value rose to 29.3%. Moreover, the peak value of the heat release rate was remarkably decreased by 34.1% in the combustion test, accompanied by the formation of more compacted char layer and the release of more incombustible gas. Equally important another aspect is that the PC containing only 0.10 wt % of TiO2@DPP possessed higher elongation at break and higher tensile strength than pure PC, correspondingly increased by 27.7 and 14.7%. The analysis of the flame-retardant mechanism revealed that the improved fire retardance of PC is primarily ascribed to the barrier action of a cross-linking network containing phosphorus and titanium, the dilution of nonflammable gases such as H2O, and the quenching effect of free radicals which are from the phosphorous group in the gas phase. All these experimental results demonstrate that the core-shell hybrid TiO2@DPP may achieve a simultaneous significant improvement in fire retardance and mechanical properties of PC.

14.
J Vis Exp ; (126)2017 08 18.
Article in English | MEDLINE | ID: mdl-28872139

ABSTRACT

Bacterial biofilms are surface-associated communities that are vastly studied to understand their self-produced extracellular polymeric substances (EPS) and their roles in environmental microbiology. This study outlines a method to cultivate biofilm attachment to the System for Analysis at the Liquid Vacuum Interface (SALVI) and achieve in situ chemical mapping of a living biofilm by time-of-flight secondary ion mass spectrometry (ToF-SIMS). This is done through the culturing of bacteria both outside and within the SALVI channel with our specialized setup, as well as through optical imaging techniques to detect the biofilm presence and thickness before ToF-SIMS analysis. Our results show the characteristic peaks of the Shewanella biofilm in its natural hydrated state, highlighting upon its localized water cluster environment, as well as EPS fragments, which are drastically different from the same biofilm's dehydrated state. These results demonstrate the breakthrough capability of SALVI that allows for in situ biofilm imaging with a vacuum-based chemical imaging instrument.


Subject(s)
Biofilms/growth & development , Shewanella/chemistry , Shewanella/physiology , Spectrometry, Mass, Secondary Ion/methods
15.
Biointerphases ; 12(5): 05G601, 2017 Aug 18.
Article in English | MEDLINE | ID: mdl-28821212

ABSTRACT

The aggregation of syntrophic Geobacter metallireducens and Geobacter sulfurreducens is beneficial for enhancing direct interspecies electron transfer (DIET). Although DIET was suspected to occur on the microbial community surface, the surface chemical speciation of such cocultured communities remains unclear. In order to better understand surface interactions related to DIET, the authors characterized a series of samples associated with syntrophic G. metallireducens and G. sulfurreducens using surface sensitive time-of-flight secondary ion mass spectrometry (ToF-SIMS). Principal component analysis was used in spectral analysis. Our results show that the syntrophic Geobacter aggregates are significantly different from their planktonic cells, indicating a distinct chemical composition (i.e., amino acids, fatty acids, and lipids) and structure formed on their surface. Among these characteristic components, amino acid fragments dominated in the variance, suggesting the importance of proteins in the coculture. Additionally, the quorum sensing signal molecule N-butyryl-l-homoserine lactone was observed in cocultured Geobacter aggregates, implying its role in syntrophic growth and aggregate formation. Furthermore, the electron acceptor organism G. sulfurreducens was shown to be the dominant species in syntrophic communities that drove the syntrophic growth. These results demonstrate that unique chemical compositions distinguish syntrophic Geobacter aggregates from planktonic cells and suggest that ToF-SIMS may be a promising tool to understand the syntrophic mechanism and investigate interspecies electron transfer pathways in complex biofilms.


Subject(s)
Biofilms , Geobacter/chemistry , Geobacter/growth & development , Microbial Consortia , Surface Properties , 4-Butyrolactone/analogs & derivatives , 4-Butyrolactone/analysis , Amino Acids/analysis , Electron Transport , Lipids/analysis , Mass Spectrometry
16.
Materials (Basel) ; 6(12): 5690-5699, 2013 Dec 05.
Article in English | MEDLINE | ID: mdl-28788417

ABSTRACT

In this work, we designed a visual biosensor for dopamine (DA) detection using magnetic Fe3O4 particles and dithiobis(sulfosuccinimidylpropionate)-modified gold nanoparticles (DTSSP-AuNPs) as the recognition elements. Specifically, DA molecules were assembled onto the surface of DTSSP-AuNPs via the amine coupling reaction between the amino group of DA and activated carboxyl group of DTSSP. Accordingly, DA-anchored DTSSP-AuNPs were captured by Fe3O4 through the interaction of catechol and iron. In a magnetic field, the formed Fe3O4-DA-DTSSP-AuNPs conjugates were easily removed from the solution, leading to fading of the AuNPs suspension and decrease of the UV/Vis signal. As a result, a detection limit of 10 nM for DA was achieved. The theoretical simplicity and high selectivity demonstrated that the sandwich-type strategy based on Fe3O4 and AuNPs would lead to many colorimetric detection applications in clinical study by rationally designing the surface chemistry of AuNPs and Fe3O4.

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