ABSTRACT
SUMMARY: We present a web server, GenCLiP 3, which is an updated version of GenCLiP 2.0 to enhance analysis of human gene functions and regulatory networks, with the following improvements: i) accurate recognition of molecular interactions with polarity and directionality from the entire PubMed database; ii) support for Boolean search to customize multiple-term search and to quickly retrieve function related genes; iii) strengthened association between gene and keyword by a new scoring method; and iv) daily updates following literature release at PubMed FTP. AVAILABILITY: The server is freely available for academic use at: http://ci.smu.edu.cn/genclip3/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
ABSTRACT
Salvianolic acid A (SAA) is a minor phenolic carboxylic acid extracted from Salviae miltiorrhizae Bunge (Danshen). SAA exhibits a variety of pharmacological activities, such as antioxidative, anti-thrombotic, neuroprotective, and anti-fibrotic effects, as well as protection from myocardial ischemia and prevention of diabetes and other diseases. Furthermore, SAA has shown renal-protective effects in doxorubicin-induced nephropathy. However, there has been limited research regarding the effects of SAA and underlying mechanisms in chronic kidney disease (CKD). Here, we examined the effects and molecular mechanisms of SAA in an established animal model of 5/6 nephrectomized (5/6Nx) rats. The rats were injected with SAA (2.5, 5, and 10 mg/kg per day, intraperitoneally (ip)) for 28 days. SAA dose-dependently lowered the levels of urine protein, blood urea nitrogen, serum creatinine, plasma total cholesterol, and plasma triglycerides in 5/6Nx rats. Histological examination revealed that SAA dose-dependently attenuated renal pathological lesions, evidenced by reduced renal tubulointerstitial fibrosis by decreasing the expression levels of tumor growth factor-ß1 and α-smooth muscle actin in 5/6Nx rats. Moreover, SAA dose-dependently inhibited the activation of nuclear factor-κB (NF-κB) and p38 mitogen-activated protein kinase (MAPK) signaling pathways, subsequently attenuating the secretion of tumor necrosis factor-α and interleukin-1ß and inhibiting the expression of monocyte chemotactic protein-1, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 in kidneys of 5/6Nx rats. The above results were consistent with those obtained in lipopolysaccharide-induced HK-2 cells in vitro (a recognized in vitro inflammatory model). In conclusion, our results demonstrated that SAA effectively attenuates kidney injury in 5/6Nx rats. The therapeutic effects of SAA on kidney injury can be attributed to its anti-inflammatory activities through inhibition of the activation of the NF-κB and p38 MAPK signaling pathways.
Subject(s)
Caffeic Acids/therapeutic use , Lactates/therapeutic use , MAP Kinase Signaling System/drug effects , Renal Insufficiency, Chronic/prevention & control , Transcription Factor RelA/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , Animals , I-kappa B Proteins/metabolism , Kidney/pathology , Male , Rats, Sprague-Dawley , Renal Insufficiency, Chronic/pathologyABSTRACT
Interlukin-6 (IL-6) is a multifunctional cytokine produced by several cell types that has a role in fibrosis. Fibroblasts (FBs) maintain this underlying pathogenic change through regulation of IL-6 production; however, its potential functional role in regulating surrounding cellular structural changes during ischemic myocardial remodeling remains unexplored. Here, we generated FBs, cardiomyocytes (CMs), and blood vascular endothelial cells (ECs) from the ventricles of neonatal rats. IL-6 was then overexpressed in FBs and the cells were treated with IL-6 receptor inhibitor (IL6RI), TGF-ß1 receptor inhibitor (TßRI), or MMP2/MMP9 inhibitor (MMPI) using monoculture or coculture models under hypoxic conditions. The results indicate that overexpression of IL-6 is sufficient to induce myofibroblastic proliferation, differentiation, and fibrosis, probably via increased TGF-ß1-mediated MMP2/MMP3 signaling. The use of IL6RI, TßRI, or MMPI diminished these effects. In addition, IL-6 activated the apoptosis-associated factors Caspase3 and Smad3, and decreased the expression of anti-apoptotic factor Bcl2, resulting in apoptosis of CMs under hypoxic coculture: IL6RI or TßRI inhibited these effects. Unexpectedly, IL-6-overexpressing FBs significantly increased the angiogenesis of ECs, which involved significant increases in the expression of proangiogenic growth factors. Treatment of FBs with IL6RI or TßRI in coculture with ECs reduced the levels of secreted proangiogenic growth factors, and the angiogenesis of ECs was significantly downregulated. Thus, IL-6 functions in ischemic myocardial remodeling through multifunctional reprogramming of hypoxia-associated FBs towards fibrosis via upregulation of the TGF-ß1 signaling pathway.
Subject(s)
Hypoxia/metabolism , Interleukin-6/biosynthesis , Myocardium/metabolism , Myocardium/pathology , Transforming Growth Factor beta1/metabolism , Animals , Apoptosis , Cell Proliferation , Cells, Cultured , Coculture Techniques , Endothelial Cells/immunology , Endothelial Cells/metabolism , Endothelial Cells/pathology , Fibroblasts/immunology , Fibroblasts/metabolism , Fibroblasts/pathology , Fibrosis , Hypoxia/immunology , Hypoxia/pathology , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Matrix Metalloproteinase Inhibitors/pharmacology , Models, Cardiovascular , Myocardium/immunology , Myocytes, Cardiac/immunology , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Myofibroblasts/immunology , Myofibroblasts/metabolism , Myofibroblasts/pathology , Neovascularization, Physiologic , Protein Serine-Threonine Kinases/antagonists & inhibitors , Rats , Receptor, Transforming Growth Factor-beta Type I , Receptors, Interleukin-6/antagonists & inhibitors , Receptors, Transforming Growth Factor beta/antagonists & inhibitors , Signal Transduction , Up-RegulationABSTRACT
Recent studies of the coupling between the plasmonic excitations of metallic nanostructures with the excitonic excitations of molecular species have revealed a rich variety of emergent phenomena known as plexcitonics. Here, we use a combined experimental and theoretical approach to demonstrate new and intriguing aspects in the ultrafast nonlinear responses of strongly coupled hybrid Fano systems consisting of gold nanorods decorated with near-infrared dye molecules. We show that the severely suppressed linear absorption around the Fano dip significantly enhances the unidirectional energy transfer from the plasmons to the excitons and further allows one-photon nonlinearity to be drastically and reversibly tuned. These striking observations are interpreted within a microscopic model stressing on two competing processes: saturated plasmonic absorption and weakened destructive Fano interference from the bleached excitonic absorption. The unusually strong one-photon nonlinearity revealed here provides a promising strategy in fabricating nanoplasmonic devices with both pronounced nonlinearities and good figures of merit.
ABSTRACT
UNLABELLED: Identifying biological functions and molecular networks in a gene list and how the genes may relate to various topics is of considerable value to biomedical researchers. Here, we present a web-based text-mining server, GenCLiP 2.0, which can analyze human genes with enriched keywords and molecular interactions. Compared with other similar tools, GenCLiP 2.0 offers two unique features: (i) analysis of gene functions with free terms (i.e. any terms in the literature) generated by literature mining or provided by the user and (ii) accurate identification and integration of comprehensive molecular interactions from Medline abstracts, to construct molecular networks and subnetworks related to the free terms. AVAILABILITY AND IMPLEMENTATION: http://ci.smu.edu.cn. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Subject(s)
Data Mining/methods , Gene Regulatory Networks , Genes , Software , Cluster Analysis , Humans , Internet , MEDLINEABSTRACT
BACKGROUND: Deubiquitinases, such as CYLD, A20 and Cezanne, have emerged as negative regulators that balance the strength and duration of NF-κB signaling through feedback mechanisms. However, how these serial feedback loops are simultaneously disrupted in cancer remains unclear. The purpose of this study is to investigate the correlation of Cezanne expression with clinicopathological/prognostic value in hepatocellular carcinoma (HCC). METHODS: The expression levels of Cezanne and matrix metallopeptidase 9 (MMP-9) were assessed by immunohistochemistry in 230 HCC specimens. The correlation between expression of Cezanne and MMP-9, clinicopathological/prognostic value in hepatocellular carcinoma was examined. RESULTS: Cezanne reduction in HCC was significantly associated with larger tumor, satellite nodule, vascular invasion, TNM stage, BCLC stage and early recurrence. Kaplan-Meier analysis showed that Cezanne was a great predictive factor for overall survival (OS) and time to recurrence (TTR). The expression of Cezanne was decreased in TNM and BCLC stage-dependent manner. In addition, Cezanne reduction was associated with poor prognosis in patients subgroups stratified by tumor size, tumor differentiation, TNM stage and BCLC stage. Moreover, Cezanne was negatively associated with MMP-9 among 230 HCC samples. Patients who had Cezanne downregulation, in which cancer cells showed high invasiveness, had shorter TTR and poor OS. Furthermore, the coindex of Cezanne and preoperative serum AFP levels was significantly correlated with OS and TTR. CONCLUSION: Cezanne has a pivotal role in tumor progression and prognosis, and may act as a potential prognostic biomarker for survival in HCC patients.
Subject(s)
Carcinoma, Hepatocellular/enzymology , Carcinoma, Hepatocellular/pathology , Disease Progression , Endopeptidases/metabolism , Liver Neoplasms/enzymology , Liver Neoplasms/pathology , Adolescent , Adult , Aged , Disease-Free Survival , Down-Regulation , Female , Humans , Kaplan-Meier Estimate , Male , Matrix Metalloproteinase 9/metabolism , Middle Aged , Multivariate Analysis , Neoplasm Invasiveness , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Prognosis , Time Factors , Young Adult , alpha-Fetoproteins/metabolismABSTRACT
OBJECTIVE: To compare the outcomes of hepatic resection and transcatheter arterial chemoembolization for resectable hepatocellular carcinoma with hepatic vein tumor thrombus. METHODS: From January 2006 to November 2013, 28 patients initially diagnosed with resectable hepatocellular carcinoma combined with hepatic vein tumor thrombus received hepatic resection. These patients were compared with 56 case-matched controls (1:2 ratio) selected from a pool of 91 patients who received transcatheter arterial chemoembolization as an initial treatment during the same period. Clinical characteristics, adverse events, overall survival and survival-related factors were analyzed. RESULTS: The 1-, 2- and 3-year overall survival rates were 66.5, 37.4 and 28.5% for the hepatic resection group and 32.3, 18.7 and 15.6% for the transcatheter arterial chemoembolization group (P = 0.015), respectively. No significant difference was found between the two groups in terms of complications and mortality. Multivariate analyses revealed combined portal vein tumor thrombosis (HR = 2.116; 95% CI: 1.26-3.57; P = 0.005) and treatment allocation (hepatic resection = 2.289; 95% CI, 1.30-4.02; P = 0.004) as risk factors for overall survival. CONCLUSIONS: Hepatic resection provides a good prognosis for hepatocellular carcinoma patients with hepatic vein tumor thrombus compared with patients undergoing transcatheter arterial chemoembolization, and the most important factor related to survival was co-existence with portal vein invasion.
Subject(s)
Carcinoma, Hepatocellular/therapy , Chemoembolization, Therapeutic , Liver Neoplasms/therapy , Venous Thrombosis/complications , Adult , Aged , Carcinoma, Hepatocellular/complications , Carcinoma, Hepatocellular/mortality , Case-Control Studies , Female , Follow-Up Studies , Hepatectomy , Hepatic Veins , Humans , Liver Neoplasms/complications , Liver Neoplasms/mortality , Male , Middle Aged , Multivariate Analysis , Neoplasm Recurrence, Local , Portal Vein , Risk Factors , Survival RateABSTRACT
Straw incorporation is significant for straw reduction and reutilization, and is clearly required in the twelfth five-year-plan for national economic and social development of the People's Republic of China. The incorporated straw will naturally decompose and release the component of dissolved organic matter (DOM). At present, it lacks the research on straw humification behavior controlled by environmental factors and complexation effect between humification component and metal ions with fluorescence spectrometry in the representative region of loess. The fluorescence spectrometry was used to reveal the 3D-EEMs characteristics of DOM affected by temperatures and lead ions in the straw humification process, and the modified Stern-Volmer equation and Van't Hoff equation were applied to indicate the complexation parameters and thermodynamic constants between lead ions and DOM. The results showed: the humification temperatures affected little on fluorescence peaks of DOM and no peaks were obviously found to appear or disappear from the 3D-EEMs results. The fluorescence intensity decreased gradually at higher temperatures and in the presence of lead ions, the quenching effect might work in the process. The binding ability was more significant between lead ions and visible fulvic-like component shown from modified Stern-Volmer equation, and the values of ƒ revealed the complexation effect of lead ions and functional groups in DOM. Static quenching was the primary mechanism during the reaction process. The constants in Van't Hoff equation suggested the reaction was spontaneous and endothermic, and the disordered degree and the complexity were relatively low in the reaction system. The 3D-EEMs were acceptable to illustrate the variation of DOM characteristics under different temperatures and in the presence of lead ions in the straw humification process.
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Heavy metal is regarded as one of the most representative contaminants in soil, and the chemical speciation is greatly related to the toxicity and transformation behavior, which attracts the attention of researchers for years. The environmental factors could change the speciation of heavy metals, plus to the complexity of soil system, and the transformation variation of speciation might occasional existed under similar conditions. At present, the different viewpoints of related issues are urgent to be investigated. The characteristics of DOM from straw humification were revealed with UV spectra, 3D-EEMs spectra and FTIR spectra, and the Tessier Sequential Extraction Procedure was used to study the speciation transformation behavior of lead affected by DOM. The linear relationship of the contents between DOC and lead bound to organic matter was indicated to further discuss the influence mechanism of lead speciation using FTIR. The results showed: the absorbance peak of DOM located in 229 nm in UV spectra, and the fluorescence peaks appeared around the regions of λ(ex)/em = 250/350 nm, λ(em) = 250/450 nm and λ(ex) = 330/450 nm, referred as UV fulvic-like fluorescence, and visible humic-like fluorescence, respectively. The dominant functional groups of DOM included--OH, C==O and N--H. The three fractions contents of lead (exchangeable, bound to iron and manganese oxides, residual) decreased, while that of lead bound to carbonates varied little. The contents of DOC and lead bound to organic matter appeared positive correlation (r == 0.691 8), indicating the effective complexation between DOM and lead ions. The functional groups of -OH, C==O and --COOH played an important role for the speciation transformation of lead, suggested from the FTIR spectra.
ABSTRACT
The soil contamination of heavy metals, from the areas of mine, highway, industrial area, agricultural land and so on, is nowadays a serious issue all over the world. The contamination of heavy metals in large agricultural area might lead to the decrease of products quality and economic value. Actually, the accumulation amount of heavy metals by crops is much more related to the activated speciation, which is exchangeable and able to transform to the forms of carbonates, Fe-Mn oxides, organic matter and residual. Thus, the investigation to reveal the transformation mechanism of heavy metals caused by soil conditions might be appropriate to reduce the contaminated risk to crops. The vermicular red soil from the agricultural area of central China was used as sample in the paper, and the Tessier Sequential Extraction Procedure-atomic absorption spectroscopy (AAS) was applied to discuss the chemical speciation and non-biological transformation mechanism of Pb at different conditions. The results showed: the total amount of Pb is 32.56 mg x kg(-1), lower than the first level of the State Environmental Quality Standard for Soils. The Pb content of different speciation, with decreased concentration, is residual (54.55% of total Pb content), bound to Fe-Mn oxides, bound to organic matter, bound to carbonates and exchangeable. The pH value of red soil is related to the charge amount on surface of inorganic colloids and organic matter, and the water content of red soil would change the redox potential, effective for the variation of chemical speciation of Pb. The environmental factors of straw dosage and aging time could change Pb speciation, with Pb concentration of residual form the highest. The Muller index of Igeo is 0.3025, indicating the contribution of human activities. The Tessier Sequential Extraction Procedure-AAS is effective for the non-biological transformation mechanism identification of Pb speciation in red soil.
ABSTRACT
Crop straw is the dominant by-product from agriculture and is regarded as the new source of non-point contamination. Straw incorporation is possible to solve the issues of straw reduction and reutilization, which is clearly required in the twelfth five-year-plan for national economic and social development of the People's Republic of China. At present, it is of noticeable lack of the investigation on straw incorporation behavior and detail humification product analysis in the representative regions under different environmental conditions. The ultraviolet and fluorescence spectrometry were used to reveal the characteristics of dissolved organic matter (DOM), affected by pH values, in the straw humification process in loess region. The results showed: the ultraviolet absorbance of DOM samples increased firstly and then decreased with the increasing wavelength from 200 to 700 nm, and the maximum absorbance peaks appeared around the wavelength of 240 nm. The maximum absorbance peaks (λmax) were greater at pH values of 6, 8 and 9 than that of 7, and the low degree of humification was indicated from the values of SUVA254, E3/E4 and A253/A203, caused by the short period of humification. The fluorescence peaks of extracted DOM from loess appeared around the regions of λ(dx/em) = 250/330 and λ(ex/em) = 325/450, referred as UV fulvic-like fluorescence, and visible fulvic-like and humic-like fluorescence, respectively. The increasing pH values resulted in the greater wavelength of absorbance peak, suggesting the increased aromaticity and conjugated degree, and the novel fluorescence peak was found in λ(ex/em) = 250/450. The pH values were more effective to change the UV fulvic-like fluorescence peaks intensity (increased firstly and then decreased) than that of visible fulvic-like and humic-like fluorescence, which might be related to buffer effect, fluorescence quenching (side effects) and component structure. The ultraviolet and fluorescence spectrometry were acceptable to illustrate the characteristics variation of DOM affected by pH values in the straw humification process.
Subject(s)
Agriculture/methods , Organic Chemicals/analysis , Plant Stems/chemistry , Soil/chemistry , Crops, Agricultural/chemistry , Spectrometry, Fluorescence , Spectrophotometry, UltravioletABSTRACT
Nowadays, the wastewater quantity discharged yearly from tannery industry is around 0. 2 billion t in China. The contaminants of tannery wastewater include macromolecular organic matters, such as grease, fur scraps and collagen, and the alkaline wastewater appears to be of high content of salt and COD. The quality of tannery wastewater is monitored strictly among all kinds of industry wastewater. In the treatment process of tannery wastewater, the quality of inlet and outlet water is generally analyzed. In fact, the transformation behavior of contaminants should be additionally checked to optimize the treatment conditions. Dissolved organic matter (DOM) is commonly existed in water-bodies and helpful to understand the physicochemical characteristics, while the related work should be further studied on tannery wastewater. The approaches of elemental analysis, thermal gravimetric analysis (TG), Fourier infrared spectroscopy (FTIR) and 13C nuclear magnetic resonance (13C NMR) were used to reveal the characteristics of DOM in the treatment process of tannery wastewater. The results showed the carbon content of DOM samples increased gradually, atomic ratios of H/C increased firstly and then decreased, indicating the organic matters were decomposed into chain structures firstly, finally forming the component hard to degraded. The pyrolysis process of DOM mainly proceeded in the regions of 110~530 °C (aliphatic compound, protein, etc. ) and 530~800 °C (aromatic ring, single bond of C-C, etc. ). The functional groups of DOM included -OH, -NH2, C=O and so on, and the aromatic substances were detected, shown from FTIR figures, in the later period of the reaction, caused by the metabolism effect of micro-organism. The content of alkoxy-C increased to the maximum in the second biochemical pond, and the minimum content of aromatic-C appeared in the second biochemical pond, suggesting the transformation behavior of carbon functional groups. The investigation on DOM in tannery wastewater is significant to understand the purification mechanism of contaminants in tannery wastewater.
Subject(s)
Spectroscopy, Fourier Transform Infrared , Tanning , Wastewater/analysis , Water Pollutants, Chemical/analysis , Carbon , Magnetic Resonance Imaging , Magnetic Resonance SpectroscopyABSTRACT
Soil contamination is regarded as one of the most serious issues to humanity all over the world. It is statistically believed that over one-fifth of the farmland, that is 20 million ha, is found to be contaminated by heavy metals in China. And the related issues, caused by soil contamination, of food safety, human health and eco-environmental quality attract much attention by public with more serious contamination than before. The technological approach for soil remediation is widely investigated. The technology of soil washing is effective for contaminants removal, while the treatment procedure might lead to component leaching from soil system, harmful for soil fertility, physicochemical properties and ecological functions. The study of spectral characteristics on leaching component is significant for decision-making of contaminated sites remediation and ecological function recovery, while the related investigation seems weaker nowadays. The paper mainly revealed the leaching characteristics of component from Pb/Cd contaminated loess in the washing process with Ethylene Diamine Tetraacetic Acid (EDTA) in reaction column, and the research objectives included base cations, loess nutrients, clay minerals and organic matter. The variation of clay minerals was analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM), and 3D-EEM fluorescence spectrum was used for the identification of dissolved organic matter (DOM). The experimental results showed: the leaching component from loess is detected in the washing reaction. The final removal efficiency (240 min) of Pb and Cd from loess are 49. 86% and 62.25%, respectively. The sodium ions and nitrate nitrogen are the most easily leaching component, and little difference of clay minerals is identified before and after washing reaction. The fulvic acid-like (FA-like) material was firstly (10 min) detected around E(ex/em) = 240-250/320-340 and E(ex/em) = 260-290/450-470 in 3D-EEM fluorescence spectrum, and the humin acid-like (HA-like, E(ex/em) = 290-320/430-490) appeared at 60 min with weaker fluorescence intensity of FA-like (E(ex/em) = 240/320). The decreased fluorescence intensity of FA-like and HA-like, shown after 120 min and 240 min, indicated the component variation of DOM in the leaching solution. The spectroscopy approach is appropriate for characteristics identification of leaching component from co-contaminated loess.
ABSTRACT
Tannery industry is one of the major traditional industries and important wastewater sources in China. The existing research mainly focus on the quality of inlet and outlet water, rather than the purification and transformation behavior of dissolved organic matter (DOM) in the treatment process of tannery wastewater. The UV spectra and fluorescence spectroscopy were used to detect the spectral characteristics of water samples in the treatment process, and it is analyzed that the formation process and the linear relationships between total fluorescence intensity and parameters. The results showed: the UV absorbance of DOM in wastewater increased firstly and then decreased with longer wavelength, and the wave peaks were found around the wavelength of 230 nr. The values of A253 /A203 and SUVA254 increased firstly and then decreased, indicating the complex reaction process related to free substituent and aromatic rings. The fluorescence peaks appeared at the regions of λ(ex/em) = 320-350/440- 460 and λ(ex/em) = 270-300/390-420, referred as visible humic-like and visible fulvic-like fluorescence, respectively. With the treatment process of tannery wastewater, the following fluorescence phenomenon were monitored, such as the blue-shift of humic-like fluorescence peak in the hydrolytic acidification tank, the appearance of tryptophan fluorescence peak in the second biochemical pond (λ(ex/em) = 290/340), the weak fluorescence peak in the fourth biochemical pond (λ(ex/em) = 350/520) and the stabilized fluorescence characteristics in the secondary sedimentation tank and water outlet. The achievements are helpful to investigate the degradation and formation behavior of water components, and significant for the fluorescence variation analysis in the treatment system. The removal rate of total fluorescence intensity of tannery wastewater fit better the removal rate of TOC with coefficient of r 0.835 5. The UV spectra and 3D-EEMs are effective to reveal the purification behavior and mechanism of tannery wastewater.
Subject(s)
Organic Chemicals/analysis , Tanning , Wastewater/analysis , Industrial Waste/analysis , Spectrum Analysis , Water PurificationABSTRACT
Common methods to prepare SERS (surface-enhanced Raman scattering) probes rely on random conjugation of Raman dyes onto metal nanostructures, but most of the Raman dyes are not located at Raman-intense electromagnetic hotspots thus not contributing to SERS enhancement substantially. Herein, a competitive reaction between transverse gold overgrowth and dye conjugation is described to achieve site selective conjugation of Raman dyes to the hotspots (ends) on gold nanorods (GNRs). The preferential overgrowth on the nanorod side surface creates a barrier to prevent the Raman dyes from binding to the side surface except the ends of the GNRs, where the highest SERS enhancement factors are expected. The SERS enhancement observed from this special structure is dozens of times larger than that from conjugates synthesized by conventional methods. This simple and powerful strategy to prepare SERS probes can be extended to different anisotropic metal nanostructures with electromagnetic hotspots and has immense potential in in-depth SERS-based biological imaging and single-molecule detection.
Subject(s)
Nanotechnology , Nanotubes/chemistry , Spectrum Analysis, Raman , Anisotropy , Coloring Agents/chemistry , Contrast Media/chemistry , Electromagnetic Radiation , Gold/chemistry , Metal Nanoparticles/chemistry , Metals/chemistry , Microscopy, Electron, Transmission , Nanostructures/chemistry , Scattering, Radiation , Surface Plasmon Resonance , Surface PropertiesABSTRACT
The arid loess in northwestern China is one of the dominant soil types nationwide, the removal efficiency of Pb and chlorpyrifos in simulated co-contaminated loess was investigated by ethylene diamine tetra-acetic acid (EDTA) in ex-situ column experiment, and methods of ultraviolet spectroscopy (UV), atomic absorption spectroscopy (AAS), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier transform infrared spectroscopy (FTIR) were used to reveal the remediation characteristics and mechanism. The results showed that the flow rate and pH value of EDTA are responsible for the reaction curves. In the experimental conditions, the removal rates of Pb and chlorpyrifos are more than 70% and 90%, respectively, and the bioavailability of heavy metals decreases greatly. The SEM micrographs indicate the dense and rough surface of loess, and unclear surface and enhanced dispersion of particles appear after the reaction. The EDS results explain the phenomenon of Pb removal and elemental loss. The move, disappearance and decrease of wave peaks, shown from FTIR spectra, are the effect of various chemical environment in loess, and the reaction is more appropriate for physisorbed pollutants removal. The achievements are acceptable for co-contaminated loess remediation by EDTA in ex-situ column, showing potential for future application.
ABSTRACT
The original loess from western China was used as soil sample, the spectral methods of scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS), elemental analysis, Fourier transform infrared spectroscopy (FT-IR) and 13C nuclear magnetic resonance (13C NMR) were used to investigate the characteristics of decomposed straw and formed humic acids in compound polluted arid loess. The SEM micrographs show the variation from dense to decomposed surface, and finally to damaged structure, and the EDS data reveal the phenomenon of element transfer. The newly-formed humic acids are of low aromaticity, helpful for increasing the activity of organic matters in loess. The FTIR spectra in the whole process are similar, indicating the complexity of transformation dynamics of humic acids. The molecular structure of humic acids becomes simpler, shown from 13C NMR spectra. The spectral methods are useful for humic acids identification in loess region in straw incorporation process.
Subject(s)
Humic Substances/analysis , Soil/chemistry , Spectroscopy, Fourier Transform Infrared , China , Environmental Pollution , Magnetic Resonance Spectroscopy , Plant StemsABSTRACT
The CdS/SiO(2) core/shell nanowires (NWs) with controlled shell thickness were successfully synthesized and subsequently heat-treated at 500 °C. The influences of silica shell coating and annealing processes on their optical properties have been investigated. Compared with original CdS NWs, the annealed CdS/SiO(2) NWs exhibited an enhanced band-edge emission with slowed photoluminescence lifetime, while the intensity of defect emission decreased. The results were ascribed to the surface passivation and recrystallization by shell coating and annealing. We believe our finding would help improving the optical properties of semiconductor NWs, and facilitate its applications in various realms, such as nanoscale emitter, sensor, and photoelectric device.
Subject(s)
Cadmium Compounds/chemistry , Luminescent Measurements/instrumentation , Nanotubes/chemistry , Nanotubes/ultrastructure , Selenium Compounds/chemistry , Silicon Dioxide/chemistry , Equipment Design , Equipment Failure Analysis , Hardness , Hot Temperature , Particle SizeABSTRACT
This paper describes a facile method for synthesis of Au-AgCdSe hybrid nanorods with controlled morphologies and spatial distributions. The synthesis involved deposition of Ag tips at the ends of Au nanorod seeds, followed by selenization of the Ag tips and overgrowth of CdSe on these sites. By simply manipulating the pH value of the system, the AgCdSe could selectively grow at one end, at both the ends or on the side surface of a Au nanorod, generating a mike-like, dumbbell-like, or toothbrush-like hybrid nanorod, respectively. These three types of Au-AgCdSe hybrid nanorods displayed distinct localized surface plasmon resonance and photoluminescence properties, demonstrating an effective pathway for maneuvering the optical properties of nanocrystals.
ABSTRACT
OBJECTIVE: To investigate the prevalence characters of dyslipidemia and borderline dyslipidemia in aging residents from Beijing communities and to evaluate the relative risk of cardiovascular risk factor (CRF) to dyslipidemia. METHODS: The samples were selected by random cluster multistage method. Serum lipid level and CRF were determined through questionnaire, physical examination and biochemical detection for 1974 subjects who was 65 and over 65 years old in Beijing communities. RESULTS: Age- and sex-adjusted standardized incidence of dyslipidemia and borderline dyslipidemia in ≥ 65 yrs was 35.11% (693/1974) and 28.57% (564/1974) respectively, optimal lipid was 36.32% (717/1974).Vs optimal status 3 borderline factors(BF) , 1 major CRF, 2 CRFs, and 3 CRFs to have dyslipidemia, the relative risks are OR = 1.537, 95%CI 0.597-3.959, OR = 1.898, 95%CI 0.993-3.628, OR = 2.441, 95%CI 1.268-4.698, and OR = 4.256, 95%CI 2.104-8.608 respectively. CONCLUSIONS: The prevalence of major CRFs of ≥ 65 yrs resident from Beijing communities are higher than the average level of China. The risk is higher while the number of borderline and major CRFs much more.