84 research outputs found

    The Analysis of the International Climate Change on Environmental Justice

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    Since the Club of Rome published "Limits to Growth" in 1972, the environmental problems have caused the attention of people around the world and become a global issue. The international community has also organized special meetings to promote the study of environmental issues. One of the most important meetings is the United Nations Conference on Environment and Development, held every year since 1972. The most important issue is on how to deal with climate change, which has become an international mainstream issue. From the perspective of the environmental justice, the following is a brief analysis of the negotiations on international climate changes, based on the opportunities of the 2009 Copenhagen Summit, the 2010 Cancun Summit and the 2011 South Africa Bender Climate Summit

    Notas técnicas.Tipos de asfaltos y su empleo en pavimentos

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    ABSTRACT: The idea of acoustic activation of surface diffusion is explored theoretically and in atomistic simulations. It is found that a substantial diffusion enhancement by surface acoustic waves is possible via (1) transient surface strain-induced modification of the diffusion barriers, (2) adiabatic variation in the surface temperature, and (3) dynamic coupling of the acoustic waves with vibrational states of adsorbed species. The approximate scaling laws describing the first two effects are established and verified in kinetic Monte Carlo simulations. The combined contribution of all three effects is studied in molecular dynamics simulations, and the conditions for the diffusion activation through the dynamic coupling are elucidated. The acoustic enhancement of surface diffusion provides an attractive alternative to thermal activation in thin film growth on heat-sensitive substrates. 1

    Comparative Proteomic Analysis of Streptococcus suis Biofilms and Planktonic Cells That Identified Biofilm Infection-Related Immunogenic Proteins

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    Streptococcus suis (SS) is a zoonotic pathogen that causes severe disease symptoms in pigs and humans. Biofilms of SS bind to extracellular matrix proteins in both endothelial and epithelial cells and cause persistent infections. In this study, the differences in the protein expression profiles of SS grown either as planktonic cells or biofilms were identified using comparative proteomic analysis. The results revealed the existence of 13 proteins of varying amounts, among which six were upregulated and seven were downregulated in the Streptococcus biofilm compared with the planktonic controls. The convalescent serum from mini-pig, challenged with SS, was applied in a Western blot assay to visualize all proteins from the biofilm that were grown in vitro and separated by two-dimensional gel electrophoresis. A total of 10 immunoreactive protein spots corresponding to nine unique proteins were identified by MALDI-TOF/TOF-MS. Of these nine proteins, five (Manganese-dependent superoxide dismutase, UDP-N-acetylglucosamine 1-carboxyvinyltransferase, ornithine carbamoyltransferase, phosphoglycerate kinase, Hypothetical protein SSU05_0403) had no previously reported immunogenic properties in SS to our knowledge. The remaining four immunogenic proteins (glyceraldehyde-3-phosphate dehydrogenase, hemolysin, pyruvate dehydrogenase and DnaK) were identified under both planktonic and biofilm growth conditions. In conclusion, the protein expression pattern of SS, grown as biofilm, was different from the SS grown as planktonic cells. These five immunogenic proteins that were specific to SS biofilm cells may potentially be targeted as vaccine candidates to protect against SS biofilm infections. The four proteins common to both biofilm and planktonic cells can be targeted as vaccine candidates to protect against both biofilm and acute infections

    Immunoproteomic analysis of bacterial proteins of Actinobacillus pleuropneumoniae serotype 1

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    <p>Abstract</p> <p>Background</p> <p><it>Actinobacillus pleuropneumoniae </it>(APP) is one of the most important swine pathogens worldwide. Identification and characterization of novel antigenic APP vaccine candidates are underway. In the present study, we use an immunoproteomic approach to identify APP protein antigens that may elicit an immune response in serotype 1 naturally infected swine and serotype 1 virulent strain S259-immunized rabbits.</p> <p>Results</p> <p>Proteins from total cell lysates of serotype 1 APP were separated by two-dimensional electrophoresis (2DE). Western blot analysis revealed 21 immunoreactive protein spots separated in the pH 4-7 range and 4 spots in the pH 7-11 range with the convalescent sera from swine; we found 5 immunoreactive protein spots that separated in the pH 4-7 range and 2 in the pH 7-11 range with hyperimmune sera from S259-immunized rabbits. The proteins included the known antigens ApxIIA, protective surface antigen D15, outer membrane proteins P5, subunit NqrA. The remaining antigens are being reported as immunoreactive proteins in APP for the first time, to our knowledge.</p> <p>Conclusions</p> <p>We identified a total of 42 immunoreactive proteins of the APP serotype 1 virulent strain S259 which represented 32 different proteins, including some novel immunoreactive factors which could be researched as vaccine candidates.</p

    Clinical implications of trichomonads detected in bronchoalveolar fluid by metagenomic next-generation sequencing: a multicenter retrospective study

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    BackgroundPulmonary trichomoniasis is considered a neglected disease due to failures in recognizing it, stemming from insensitive microbial methods and a lack of specific clinical features. This study aims to analyze the clinical implications of trichomonads detected in bronchoalveolar lavage fluid (BALF) by metagenomic next-generation sequencing (mNGS).MethodsThis multicenter retrospective study included patients diagnosed with pneumonia, admitted to three tertiary hospitals in China from July 2018 to September 2022, with trichomonads detected in BALF through mNGS. The analysis covered demographics, comorbidities, symptoms, laboratory findings, mNGS results, clinical treatment, and outcomes of these patients.ResultsA total of 17 patients were enrolled, comprising 14 males and 3 females. Trichomonas tenax and Trichomonas vaginalis were detected by mNGS in BALF samples of 15 and 2 patients, respectively. Patients were categorized into two groups based on the presence of risk factors for trichomonad infection, including immunocompromised conditions, uncontrolled diabetes mellitus, oral/periodontal diseases, and aspiration. Among 11 patients with risk factors (Case 1-11), 4 received nitromidazoles as part of comprehensive treatment, achieving a 100% treatment success rate. The remaining 7 patients, who did not receive nitromidazoles, had only one achieving relief after broad-spectrum antimicrobial therapy, resulting in a 14.3% treatment success rate. For the 6 patients without any risk factors for trichomonad infection (Case 12-17), none received nitromidazoles during hospitalization. However, 4 out of these 6 patients (66.7%) eventually recovered.ConclusionmNGS proves to be an efficient tool for detecting trichomonads in BALF samples. Comprehensive analysis of clinical features and laboratory indicators is essential to distinguish between infection and colonization of trichomonads. Pulmonary trichomoniasis should not be overlooked when trichomonads are detected in BALF from patients with risk factors

    Circulating tumor DNA clearance predicts prognosis across treatment regimen in a large real-world longitudinally monitored advanced non-small cell lung cancer cohort

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    Background: Although growth advantage of certain clones would ultimately translate into a clinically visible disease progression, radiological imaging does not reflect clonal evolution at molecular level. Circulating tumor DNA (ctDNA), validated as a tool for mutation detection in lung cancer, could reflect dynamic molecular changes. We evaluated the utility of ctDNA as a predictive and a prognostic marker in disease monitoring of advanced non-small cell lung cancer (NSCLC) patients.Methods: This is a multicenter prospective cohort study. We performed capture-based ultra-deep sequencing on longitudinal plasma samples utilizing a panel consisting of 168 NSCLC-related genes on 949 advanced NSCLC patients with driver mutations to monitor treatment responses and disease progression. The correlations between ctDNA and progression-free survival (PFS)/overall survival (OS) were performed on 248 patients undergoing various treatments with the minimum of 2 ctDNA tests.Results: The results of this study revealed that higher ctDNA abundance (P=0.012) and mutation count (P=8.5x10(-4)) at baseline are associated with shorter OS. We also found that patients with ctDNA clearance, not just driver mutation clearance, at any point during the course of treatment were associated with longer PFS (P=2.2x10(-1)6, HR 0.28) and OS (P=4.5x10(-6), HR 0.19) regardless of type of treatment and evaluation schedule.Conclusions: This prospective real-world study shows that ctDNA clearance during treatment may serve as predictive and prognostic marker across a wide spectrum of treatment regimens

    Identification of Candidate Susceptibility and Resistance Genes of Mice Infected with Streptococcus suis Type 2

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    Streptococcus suis type 2 (SS2) is an important swine pathogen and zoonosis agent. A/J mice are significantly more susceptible than C57BL/6 (B6) mice to SS2 infection, but the genetic basis is largely unknown. Here, alterations in gene expression in SS2 (strain HA9801)-infected mice were identified using Illumina mouse BeadChips. Microarray analysis revealed 3,692 genes differentially expressed in peritoneal macrophages between A/J and B6 mice due to SS2 infection. Between SS2-infected A/J and control A/J mice, 2646 genes were differentially expressed (1469 upregulated; 1177 downregulated). Between SS2-infected B6 and control B6 mice, 1449 genes were differentially expressed (778 upregulated; 671 downregulated). These genes were analyzed for significant Gene Ontology (GO) categories and signaling pathways using the Kyoto Encylopedia of Genes and Genomes (KEGG) database to generate a signaling network. Upregulated genes in A/J and B6 mice were related to response to bacteria, immune response, positive regulation of B cell receptor signaling pathway, type I interferon biosynthesis, defense and inflammatory responses. Additionally, upregulated genes in SS2-infected B6 mice were involved in antigen processing and presentation of exogenous peptides, peptide antigen stabilization, lymphocyte differentiation regulation, positive regulation of monocyte differentiation, antigen receptor-mediated signaling pathway and positive regulation of phagocytosis. Downregulated genes in SS2-infected B6 mice played roles in glycolysis, carbohydrate metabolic process, amino acid metabolism, behavior and muscle regulation. Microarray results were verified by quantitative real-time PCR (qRT-PCR) of 14 representative deregulated genes. Four genes differentially expressed between SS2-infected A/J and B6 mice, toll-like receptor 2 (Tlr2), tumor necrosis factor (Tnf), matrix metalloproteinase 9 (Mmp9) and pentraxin 3 (Ptx3), were previously implicated in the response to S. suis infection. This study identified candidate genes that may influence susceptibility or resistance to SS2 infection in A/J and B6 mice, providing further validation of these models and contributing to understanding of S. suis pathogenic mechanisms

    Pre-Absorbed Immunoproteomics: A Novel Method for the Detection of Streptococcus suis Surface Proteins

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    Streptococcus suis serotype 2 (SS2) is a zoonotic pathogen that can cause infections in pigs and humans. Bacterial surface proteins are often investigated as potential vaccine candidates and biomarkers of virulence. In this study, a novel method for identifying bacterial surface proteins is presented, which combines immunoproteomic and immunoserologic techniques. Critical to the success of this new method is an improved procedure for generating two-dimensional electrophoresis gel profiles of S. suis proteins. The S. suis surface proteins identified in this study include muramidase-released protein precursor (MRP) and an ABC transporter protein, while MRP is thought to be one of the main virulence factors in SS2 located on the bacterial surface. Herein, we demonstrate that the ABC transporter protein can bind to HEp-2 cells, which strongly suggests that this protein is located on the bacterial cell surface and may be involved in pathogenesis. An immunofluorescence assay confirmed that the ABC transporter is localized to the bacterial outer surface. This new method may prove to be a useful tool for identifying surface proteins, and aid in the development of new vaccine subunits and disease diagnostics

    Atomistic modeling of the generation of crystal defects and microstructure development in short pulse laser processing of metals

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    Because of the extremely fast and localized energy deposition, short-pulse (pico- and femtosecond) laser irradiation of a metal target can induce ultrafast heating (1013‑1014 K/s) and melting within a surface layer of the irradiated target as thin as tens of nanometers. The shallow melt depth produced by the short-pulse laser irradiation and the high thermal conductivity of metals then lead to very high cooling rates (1011‑1012 K/s), strong undercooling and rapid resolidification. In this study, the melting and resolidification processes occurring under conditions of extreme heating and cooling rates are investigated in large-scale atomistic simulations performed with a computational model that combines the classical molecular dynamic method with a continuum description of the laser excitation of conduction band electrons, electron‑phonon coupling and electron heat conduction. The fast melting and resolidification cycle is found to be responsible for the generation of crystal defects, nonequilibrium phases and unusual microstructure in the surface region of the irradiated target. The kinetics of the resolidification process and the microstructure of the surface region are found to be defined by a competition between the epitaxial regrowth of the substrate and nucleation of crystallites within the undercooled melted region. The dependence of the final microstructure of the surface region on the irradiation conditions is discussed based on the results of the atomistic simulations. A special consideration is given to the conditions that result in the massive homogeneous nucleation and growth of the crystallites in a strongly undercooled surface region of the target. The generation of thin nanocrystalline surface layer with a high density of the grain boundaries, twins, and stacking faults suggests an effective method for highly localized surface hardening. In addition, the possibility of metastable phase generation is illustrated by an example in which the generation of metastable BCC‑Cu structure and the following collapse into a close-packed structure through BCC‑HCP transformation are observed

    Trichostatin A Induced Bcl-2 Protein Level Decrease Mediated A549/CDDP Cells Apoptosis by Mitochondria Pathway

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    Background and objective The use of platinum-based combination chemotherpy remains the standard treatment for non-small cell lung cancer. However, the resistance to platinum limits further treatment clinically. Trichostatin A (TSA) is one of histone deacetylase (HDAC) inhibitors. It inhibits tumor cell proliferation and acts as a chemosensitizer. The aim of this study is to investigate the action mechanism of TSA on cisplatin-resistant human lung adenocarcinoma cell line A549/CDDP. Methods Cytotoxicity and cell viability was assayed by Neutral Red method. Morphologic assessment of apoptosis was determined by fluorescence microscope; cell cycle and mitochondrial membrane potential were detected by flow cytometry. In addition, A549/CDDP cells were transfected with Bcl-2 expression Vector and siRNA-bcl-2. Results A549/CDDP cells treated with TSA showed apparently cytotoxicity, IC50 of TSA was (446.59±27.32) nmol/L. The growth curve showed the ratio of growth decreased with the increase of concentration of TSA. The apoptosis appeared 24 hours after treated by (125-500) nmol/L TSA, morphologic changes including nuclear chromatin condensation. Fluorescence strength was observed with fluorescence microscope. Treated by TSA, mitochondrial membrane potential was decreased and cells were arrested at S phase. Western blotting analyses showed that the levels of Bcl-2 decreased, while expression of Bax increased. Simultaneously caspase-3 was activated. Over expression of Bcl-2 can inhibit TSA-induced A549/CDDP cell apoptosis, while the decrease of Bcl-2 enhanced the sensitivity of A549/CDDP cell to TSA. Conclusion TSA induce A549/CDDP cell apoptosis by mitochondria pathway
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