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1.
Environ Sci Technol ; 58(12): 5557-5566, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38412381

RESUMO

Wet flue gas denitrification offers a new route to convert industrial nitrogen oxides (NOx) into highly concentrated nitrate wastewater, from which the nitrogen resource can be recovered to ammonia (NH3) via electrochemical nitrate reduction reactions (NITRRs). Low-cost, scalable, and efficient cathodic materials need to be developed to enhance the NH3 production rate. Here, in situ electrodeposition was adopted to fabricate a foamy Cu-based heterojunction electrode containing both Cu-defects and oxygen vacancy loaded Cu2O (OVs-Cu2O), which achieved an NH3 yield rate of 3.59 mmol h-1 cm-2, NH3 Faradaic efficiency of 99.5%, and NH3 selectivity of 100%. Characterizations and theoretical calculations unveiled that the Cu-defects and OVs-Cu2O heterojunction boosted the H* yield, suppressed the hydrogen evolution reaction (HER), and served as dual reaction sites to coherently match the tandem reactions kinetics of NO3-to-NO2 and NO2-to-NH3. An integrated system was further built to combine wet flue gas denitrification and desulfurization, simultaneously converting NO and SO2 to produce the (NH4)2SO4 fertilizer. This study offers new insights into the application of low-cost Cu-based cathode for electrochemically driven wet denitrification wastewater valorization.


Assuntos
Amônia , Águas Residuárias , Nitratos/química , Dióxido de Nitrogênio , Desnitrificação , Eletrodos
2.
BMC Genomics ; 24(1): 423, 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37501164

RESUMO

BACKGROUND: Long terminal repeat (LTR)-retrotransposons (LTR-RTs) are ubiquitous and make up the majority of nearly all sequenced plant genomes, whereas their pivotal roles in genome evolution, gene expression regulation as well as their epigenetic regulation are still not well understood, especially in a large number of closely related species. RESULTS: Here, we analyzed the abundance and dynamic evolution of LTR-RTs in 54 species from an economically and agronomically important family, Fabaceae, and also selected two representative species for further analysis in expression of associated genes, transcriptional activity and DNA methylation patterns of LTR-RTs. Annotation results revealed highly varied proportions of LTR-RTs in these genomes (5.1%~68.4%) and their correlation with genome size was highly positive, and they were significantly contributed to the variance in genome size through species-specific unique amplifications. Almost all of the intact LTR-RTs were inserted into the genomes 4 Mya (million years ago), and more than 50% of them were inserted in the last 0.5 million years, suggesting that recent amplifications of LTR-RTs were an important force driving genome evolution. In addition, expression levels of genes with intronic, promoter, and downstream LTR-RT insertions of Glycine max and Vigna radiata, two agronomically important crops in Fabaceae, showed that the LTR-RTs located in promoter or downstream regions suppressed associated gene expression. However, the LTR-RTs within introns promoted gene expression or had no contribution to gene expression. Additionally, shorter and younger LTR-RTs maintained higher mobility and transpositional potential. Compared with the transcriptionally silent LTR-RTs, the active elements showed significantly lower DNA methylation levels in all three contexts. The distributions of transcriptionally active and silent LTR-RT methylation varied across different lineages due to the position of LTR-RTs located or potentially epigenetic regulation. CONCLUSION: Lineage-specific amplification patterns were observed and higher methylation level may repress the activity of LTR-RTs, further influence evolution in Fabaceae species. This study offers valuable clues into the evolution, function, transcriptional activity and epigenetic regulation of LTR-RTs in Fabaceae genomes.


Assuntos
Fabaceae , Retroelementos , Retroelementos/genética , Epigênese Genética , Fabaceae/genética , Evolução Molecular , Genoma de Planta , Sequências Repetidas Terminais/genética , Filogenia
3.
Opt Express ; 31(6): 10348-10357, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-37157583

RESUMO

We report the slow-light enhanced spin-resolved in-plane emission from a single quantum dot (QD) in a photonic crystal waveguide (PCW). The slow light dispersions in PCWs are designed to match the emission wavelengths of single QDs. The resonance between two spin states emitted from a single QD and a slow light mode of a waveguide is investigated under a magnetic field with Faraday configuration. Two spin states of a single QD experience different degrees of enhancement as their emission wavelengths are shifted by combining diamagnetic and Zeeman effects with an optical excitation power control. A circular polarization degree up to 0.81 is achieved by changing the off-resonant excitation power. Strongly polarized photon emission enhanced by a slow light mode shows great potential to attain controllable spin-resolved photon sources for integrated optical quantum networks on chip.

4.
Nano Lett ; 22(6): 2177-2186, 2022 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-35239344

RESUMO

Strong exciton-plasmon interactions between layered two-dimensional (2D) semiconductors and gap plasmons show a great potential to implement cavity quantum electrodynamics under ambient conditions. However, achieving a robust plasmon-exciton coupling with nanocavities is still very challenging, because the layer area is usually small in the conventional approaches. Here, we report on a robust strong exciton-plasmon coupling between the gap mode of a bowtie and the excitons in MoS2 layers with gold-assisted mechanical exfoliation and nondestructive wet transfer techniques for a large-area layer. Due to the ultrasmall mode volume and strong in-plane field, the estimated effective exciton number contributing to the coupling is largely reduced. With a corrected exciton transition dipole moment, the exciton numbers are extracted as being 40 for the case of a single layer and 48 for eight layers. Our work paves the way to realize strong coupling with 2D materials with a small number of excitons at room temperature.

5.
Int Wound J ; 20(7): 2718-2725, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36950772

RESUMO

The study aimed to assess the functional and aesthetic outcomes of abdominal full-thickness skin grafts (FTSGs) in paediatric postburn digital and palmar flexion contractures. The digital and palmar functions and aesthetics of 50 children who met the criteria were evaluated at pre-operation, the 3rd- and 12th-month post-operation, respectively. In the evaluation, the Vancouver Scar Scale (VSS), total active movement (TAM), and Jebsen-Taylor Hand Function Test (JHFT) were used. The contralateral, unaffected hand served as the criteria for functional recovery. The complications of donor sites were observed, and the take rate of skin grafts was calculated. The VSS scores at the 3rd and 12th months post-operation were lower than those before the operation. The TAM of each finger was improved at the 3rd and 12th months post-operation, compared with that before the operation. There was a significant difference in the time to complete the JHFT between the affected hand and the unaffected at the 3rd month post-operation, but no significant difference between them at the 12th month post-operation. The excellent and good take rate of the skin grafts was 90.00%.No donor site complications were observed. The abdominal FTSGs are effective in repairing paediatric digital and palmar scar contractures, with satisfying functional and aesthetic results, especially in large defects after scar release and resection.


Assuntos
Queimaduras , Contratura , Criança , Humanos , Transplante de Pele/métodos , Cicatriz/cirurgia , Cicatriz/complicações , Queimaduras/complicações , Queimaduras/cirurgia , Contratura/cirurgia , Contratura/complicações , Estética
6.
Int J Mol Sci ; 23(17)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36077556

RESUMO

Long terminal repeat (LTR)-retrotransposons (LTR-RTs) comprise a major portion of many plant genomes and may exert a profound impact on genome structure, function, and evolution. Although many studies have focused on these elements in an individual species, their dynamics on a family level remains elusive. Here, we investigated the abundance, evolutionary dynamics, and impact on associated genes of LTR-RTs in 16 species in an economically important plant family, Cucurbitaceae. Results showed that full-length LTR-RT numbers and LTR-RT content varied greatly among different species, and they were highly correlated with genome size. Most of the full-length LTR-RTs were amplified after the speciation event, reflecting the ongoing rapid evolution of these genomes. LTR-RTs highly contributed to genome size variation via species-specific distinct proliferations. The Angela and Tekay lineages with a greater evolutionary age were amplified in Trichosanthes anguina, whereas a recent activity burst of Reina and another ancient round of Tekay activity burst were examined in Sechium edule. In addition, Tekay and Retand lineages belonging to the Gypsy superfamily underwent a recent burst in Gynostemma pentaphyllum. Detailed investigation of genes with intronic and promoter LTR-RT insertion showed diverse functions, but the term of metabolism was enriched in most species. Further gene expression analysis in G.pentaphyllum revealed that the LTR-RTs within introns suppress the corresponding gene expression, whereas the LTR-RTs within promoters exert a complex influence on the downstream gene expression, with the main function of promoting gene expression. This study provides novel insights into the organization, evolution, and function of LTR-RTs in Cucurbitaceae genomes.


Assuntos
Evolução Molecular , Retroelementos , Tamanho do Genoma , Genoma de Planta , Filogenia , Retroelementos/genética , Sequências Repetidas Terminais/genética
7.
Opt Express ; 29(10): 14231-14244, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33985147

RESUMO

We report on controllable cavity modes by controlling the backscattering by two identical scatterers. Periodic changes of the backscattering coupling between two degenerate cavity modes are observed with the changing angle between two scatterers and elucidated by a theoretical model using two-mode approximation and numerical simulations. The periodically appearing single-peak cavity modes indicate mode degeneracy at diabolical points. Interactions between single quantum dots and cavity modes are then investigated. Enhanced emission of a quantum dot with a six-fold intensity increase is obtained in a microdisk at a diabolical point. This method to control cavity modes allows large-scale integration, high reproducibility and flexible design of the size, the location, the quantity and the shape for scatterers, which can be applied for integrated photonic structures with scatterer-modified light-matter interaction.

8.
Bioinformatics ; 35(10): 1780-1782, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30329029

RESUMO

SUMMARY: A new version (version 2) of the genomic dose-response analysis software, BMDExpress, has been created. The software addresses the increasing use of transcriptomic dose-response data in toxicology, drug design, risk assessment and translational research. In this new version, we have implemented additional statistical filtering options (e.g. Williams' trend test), curve fitting models, Linux and Macintosh compatibility and support for additional transcriptomic platforms with up-to-date gene annotations. Furthermore, we have implemented extensive data visualizations, on-the-fly data filtering, and a batch-wise analysis workflow. We have also significantly re-engineered the code base to reflect contemporary software engineering practices and streamline future development. The first version of BMDExpress was developed in 2007 to meet an unmet demand for easy-to-use transcriptomic dose-response analysis software. Since its original release, however, transcriptomic platforms, technologies, pathway annotations and quantitative methods for data analysis have undergone a large change necessitating a significant re-development of BMDExpress. To that end, as of 2016, the National Toxicology Program assumed stewardship of BMDExpress. The result is a modernized and updated BMDExpress 2 that addresses the needs of the growing toxicogenomics user community. AVAILABILITY AND IMPLEMENTATION: BMDExpress 2 is available at https://github.com/auerbachs/BMDExpress-2/releases. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Transcriptoma , Fluxo de Trabalho , Genoma , Anotação de Sequência Molecular , Software
9.
Cell Physiol Biochem ; 37(2): 666-76, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26344923

RESUMO

BACKGROUND/AIMS: Our previous study confirmed that Loureirin B (LB) can inhibit hypertrophic scar formation. However, the mechanism of LB-mediated inhibition of scar formation is still unknown. METHODS: Immunohistochemistry was used to detect expression of Col1, FN and TGF-ß1 in skin and scar tissue. Fibroblasts were stimulated with TGF-ß1 to mimic scar formation. LB or MAPK inhibitors were used to study the pathways involved in the process. Western blotting was used to evaluate the expression of p-JNK, p-ERK, p-p38, Col1 and FN. The contractile capacity of fibroblasts was evaluated using a gel contraction assay. Tissues were cultured ex vivo with LB to further investigate the participation of ERK and JNK in the LB-mediated inhibition of scar formation. RESULTS: FN and Col1 were up regulated in hypertrophic scars. LB down regulated p-ERK and p-JNK in TGF-ß1-stimulated fibroblasts, while levels of phosphorylated p38 did not change. The down regulation of p-ERK and p-JNK was associated with a reduction of Col1 and FN. Similarly, inhibition of ERK and JNK down regulated the expression of Col1 and FN in TGF-ß1-stimulated fibroblasts. LB down regulated protein levels of p-ERK and p-JNK in cultured hypertrophic scar tissue ex vivo. CONCLUSIONS: This study suggests that LB can inhibit scar formation through the ERK/JNK pathway.


Assuntos
Cicatriz Hipertrófica/tratamento farmacológico , Cicatriz Hipertrófica/metabolismo , Fibronectinas/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Resinas Vegetais/farmacologia , Adolescente , Adulto , Células Cultivadas , Colágeno Tipo I/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Técnicas de Cultura de Tecidos , Fator de Crescimento Transformador beta1/metabolismo , Adulto Jovem , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
10.
Aesthetic Plast Surg ; 39(4): 625-34, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26044393

RESUMO

BACKGROUND: Syngeneic adipose-derived stem cells (ASCs) promote the survival of fat grafts. But it is unclear whether allogeneic ASCs have a similar protective effect. In this study, we investigated the protective effect of allogeneic ASCs in a fat graft model of immunocompetent rats. METHODS: Syngeneic and allogeneic ASCs were derived from Lewis (LEW) and Norway-Brown rats, respectively. Fifty-four LEW rats were divided into three groups. Each LEW rat was injected subcutaneously at two paravertebral spots with adipose granules premixed with DMEM (AFT group), syngeneic ASCs (SYNG group), or allogeneic ASCs (ALLG group). Fat grafts were harvested at 7 and 14 days to examine apoptosis rates and immunochemistry staining was performed for Perilipin A and CD34. At 3 months, fat graft volume retentions were measured. The proportion of regulatory T (Treg) cells and the ratio of CD4/CD8 cells in blood were analyzed at 7 days. RESULTS: Expression of Perilipin A and CD34 was higher in the ALLG group than the AFT group at 14 days (P < 0.05). The apoptosis rate in the ALLG group decreased in comparison with the AFT group at 7 and 14 days (P < 0.05). At 3 months, allogeneic ASCs increased fat graft volume retentions (P < 0.05). No difference was found in the proportion of Treg cells and CD4/CD8 cells ratio between groups. There were no statistically significant difference between ALLG and SYNG groups at all time points (P > 0.05). CONCLUSIONS: Allogeneic ASCs protected fat grafts at the early stage and improved long-term volume retention in the fat graft model of immunocompetent rats with no or little obvious immune rejection.


Assuntos
Adipócitos/transplante , Tecido Adiposo/transplante , Sobrevivência de Enxerto , Transplante de Células-Tronco , Animais , Imunocompetência , Masculino , Ratos , Ratos Endogâmicos BN , Fatores de Tempo , Transplante Homólogo
11.
Biochem Biophys Res Commun ; 453(1): 153-9, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25264197

RESUMO

Fibrosis, tightly associated with wound healing, is a significant symptomatic clinical problem. Inflammatory response was reported to be one of the reasons. MiR-155 is relatively related with the development and requirement of inflammatory cells, so we thought reduce the expression of miR-155 in wound sites could improve the quality of healing through reduce inflammatory response. To test this hypothesis, locally antagonizing miR-155 by directly injecting antagomir to wound edge was used to reduce the expression of miR-155. We found wounds treated with miR-155 antagomir had an obvious defect in immune cells requirements, pro-inflammatory factors IL-1ß and TNF-α reduced while anti-inflammatory factor IL-10 increased. With treatment of miR-155 antagomir, the expression of α-smooth muscle actin (α-SMA), Col1 and Col3 at wound sites all reduced both from mRNA levels and protein expressions. Wounds injected with antagomir resulted in the structure improvement of collagen, the collagen fibers were more regularly arranged. Meanwhile the rate of healing did not change significantly. These results provide direct evidences that miR-155 play an important role in the pathogenesis of fibrosis and show that miR-155 antagomir has the potential therapy in prevention and reduction of skin fibrosis.


Assuntos
MicroRNAs/genética , MicroRNAs/metabolismo , Cicatrização/genética , Cicatrização/fisiologia , Actinas/genética , Animais , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Colágeno Tipo I/genética , Colágeno Tipo III/genética , Regulação para Baixo , Fibrose , Inflamação/prevenção & controle , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/antagonistas & inibidores , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Pele/lesões , Pele/metabolismo , Pele/patologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
12.
Colloids Surf B Biointerfaces ; 239: 113882, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38593511

RESUMO

Bacterial infections threaten public health, and novel therapeutic strategies critically demand to be explored. Herein, poly(amino acid) (PAA)-based drug delivery nanoparticles (NPs) were designed for eliminating Methicillin resistant Staphylococcus aureus (MRSA) via tunable release of antibiotic. Using N-acryloyl amino acids (valine, valine methyl ester, aspartic acid, serine) as monomers, four kinds of amphiphilic PAAs were synthesized via photoinduced electron/energy transfer-reversible addition fragmentation chain-transfer (PET-RAFT) polymerization and were further assembled into nano-sized delivery systems. Their assemble behavior was drove mainly by hydrophobic/hydrophilic interaction, which determined the particle size, efficacy of drug loading and release; but numerous hydrogen bonding (HB) interaction also played an important role in regulating morphologies of the NPs and enriching drug-binding capacity. By changing the HB- and hydrophobic-interaction of the PAAs, the particle sizes (240.7 nm-302.7 nm), the drug loading efficiency (9.57%-19.76%), and the Rifampicin (Rif) release rate (49.6%-69.7%) of the PAA-based NPs could be tunable. Specially, the antimicrobial properties of the Rif-loaded NPs are found to be related to the release of Rif, which was determined by its hydrophobic interaction with hydrophobic blocks and HB interaction with hydrophilic blocks. These studies provide a new outlook for the design of delivery systems for the therapy of bacterial infection.


Assuntos
Aminoácidos , Antibacterianos , Liberação Controlada de Fármacos , Staphylococcus aureus Resistente à Meticilina , Nanopartículas , Tamanho da Partícula , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Nanopartículas/química , Aminoácidos/química , Testes de Sensibilidade Microbiana , Sistemas de Liberação de Medicamentos , Rifampina/farmacologia , Rifampina/química , Polímeros/química , Polímeros/farmacologia , Interações Hidrofóbicas e Hidrofílicas
13.
Fitoterapia ; 177: 106048, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38838825

RESUMO

Four new phenols and one new aminobenzoic acid derivative, with five known phenols were isolated from the roots of Rhus chinensis Mill. Their structures were elucidated by UV, IR, HRESIMS, 1D and 2D NMR spectra, as well as optical rotations. Compound 4 significantly inhibited mouse ear inflammation (inhibitory rate of 44.03%), and significantly extended the time of pain response (extension rate of 48.55%), showing significant anti-inflammatory and analgesic effects in vivo.

14.
Sci Adv ; 10(20): eado1281, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38748802

RESUMO

The twist engineering of moiré superlattice in van der Waals heterostructures of transition metal dichalcogenides can manipulate valley physics of interlayer excitons (IXs), paving the way for next-generation valleytronic devices. However, the twist angle-dependent control of excitonic potential on valley polarization is not investigated so far in electrically controlled heterostructures and the physical mechanism underneath needs to be explored. Here, we demonstrate the dependence of both polarization switching and degree of valley polarization on the moiré period. We also find the mechanisms to reveal the modulation of twist angle on the exciton potential and the electron-hole exchange interaction, which elucidate the experimentally observed twist angle-dependent valley polarization of IXs. Furthermore, we realize the valley-addressable devices based on polarization switch. Our work demonstrates the manipulation of the valley polarization of IXs by tunning twist angle in electrically controlled heterostructures, which opens an avenue for electrically controlling the valley degrees of freedom in twistronic devices.

15.
Nanomaterials (Basel) ; 13(13)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37446485

RESUMO

Inconel 718 (IN 718) superalloys are widely used as engineering materials owing to their superior mechanical performance. And voids are unavoidable defects in IN 718 superalloy preparation, which dramatically affect the mechanical properties of IN 718 superalloys. In this work, the effects of void radius, distance from the top of the void to the substrate surface, and substrate temperature on the mechanical properties of the Ni/Ni3Al crystal are systematically investigated. It is shown that voids affect the formation of stair-rod dislocations and Shockley dislocations in the substrate, which in turn determines the mechanical properties. Thus, with the increase in void radius, Young's modulus and hardness gradually decrease. With the increase in void distance, Young's modulus and hardness increase and finally tend to be stable. In addition, the increase in substrate temperature leads to the interphase boundary becoming irregular and increases the defects in the γ and γ″ phases. As a result, Young's modulus and hardness of the substrate decrease. This work aims to provide a guideline for investigating the indentation properties of Ni-based superalloys using MD.

16.
Nat Commun ; 14(1): 4265, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37460549

RESUMO

Single photon emission of quantum emitters (QEs) carrying internal degrees of freedom such as spin and angular momentum plays an important role in quantum optics. Recently, QEs in two-dimensional semiconductors have attracted great interest as promising quantum light sources. However, whether those QEs are characterized by the same valley physics as delocalized valley excitons is still under debate. Moreover, the potential applications of such QEs still need to be explored. Here we show experimental evidence of valley symmetry breaking for neutral QEs in WSe2 monolayer by interacting with chiral plasmonic nanocavities. The anomalous magneto-optical behaviour of the coupled QEs suggests that the polarization state of emitted photon is modulated by the chiral nanocavity instead of the valley-dependent optical selection rules. Calculations of cavity quantum electrodynamics further show the absence of intrinsic valley polarization. The cavity-dependent circularly polarized single-photon output also offers a strategy for future applications in chiral quantum optics.

17.
Comput Toxicol ; 252023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36909352

RESUMO

The need to analyze the complex relationships observed in high-throughput toxicogenomic and other omic platforms has resulted in an explosion of methodological advances in computational toxicology. However, advancements in the literature often outpace the development of software researchers can implement in their pipelines, and existing software is frequently based on pre-specified workflows built from well-vetted assumptions that may not be optimal for novel research questions. Accordingly, there is a need for a stable platform and open-source codebase attached to a programming language that allows users to program new algorithms. To fill this gap, the Biostatistics and Computational Biology Branch of the National Institute of Environmental Health Sciences, in cooperation with the National Toxicology Program (NTP) and US Environmental Protection Agency (EPA), developed ToxicR, an open-source R programming package. The ToxicR platform implements many of the standard analyses used by the NTP and EPA, including dose-response analyses for continuous and dichotomous data that employ Bayesian, maximum likelihood, and model averaging methods, as well as many standard tests the NTP uses in rodent toxicology and carcinogenicity studies, such as the poly-K and Jonckheere trend tests. ToxicR is built on the same codebase as current versions of the EPA's Benchmark Dose software and NTP's BMDExpress software but has increased flexibility because it directly accesses this software. To demonstrate ToxicR, we developed a custom workflow to illustrate its capabilities for analyzing toxicogenomic data. The unique features of ToxicR will allow researchers in other fields to add modules, increasing its functionality in the future.

18.
Mutat Res ; 746(2): 135-43, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22305970

RESUMO

The traditional approach for performing a chemical risk assessment is time and resource intensive leading to a limited number of published assessments on which to base human health decisions. In comparison, most contaminated sites contain chemicals without published reference values or cancer slope factors that are not considered quantitatively in the overall hazard index calculation. The integration of transcriptomic technology into the risk assessment process may provide an efficient means to evaluate quantitatively the health risks associated with data poor chemicals. In a previous study, female B6C3F1 mice were exposed to multiple concentrations of five chemicals that were positive for lung and/or liver tumor formation in a two-year rodent cancer bioassay. The mice were exposed for a period of 13 weeks and the target tissues were analyzed for traditional histological and organ weight changes and transcriptional changes using microarrays. In this study, the dose-response changes in gene expression were analyzed using a benchmark dose (BMD) approach and the responses grouped based on pathways. A comparison of the transcriptional BMD values with those for the traditional non-cancer and cancer apical endpoints showed a high degree of correlation for specific pathways. Many of the correlated pathways have been implicated in non-cancer and cancer disease pathogenesis. The results demonstrate that transcriptomic changes in pathways can be used to estimate non-cancer and cancer points-of-departure for use in quantitative risk assessments and have identified potential toxicity pathways involved in chemically induced mouse lung and liver responses.


Assuntos
Testes de Carcinogenicidade/métodos , Carcinógenos/toxicidade , Medição de Risco/métodos , Transdução de Sinais , Transcriptoma , Animais , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Pulmonares/induzido quimicamente , Camundongos
19.
Artigo em Zh | MEDLINE | ID: mdl-22804880

RESUMO

OBJECTIVE: To study the effects of electromagnetic pulse (EMP) exposure on the morphological change and excretion functions of mouse microglia (BV-2) cells and possible mechanism. METHODS: BV-2 cells were divided into two groups: the group exposed to EMP at 200 kV/m for 200 pulses and sham exposure group. At 1, 6, 12 and 24 hour after exposure the cells and culture supernatant were collected. Cellular morphological change was observed under invert microscope, the levels of TNF-α, IL-1ß and IL-10 in culture supernatant were determined by enzyme-linked immunosorbent assay (ELISA), nitric oxide (NO) and reactive oxygen species (ROS) were detected by nitrate reductase method and DCFH-DA probe, respectively. The protein and phosphorylation levels of ERK, JNK and p38 were measured by Western Blot method. After the cells pre-treated with the inhibitor of p38 (SB203580) were exposed to EMP, the levels of NO and ROS in culture supernatant were detected. RESULTS: It was found that the large ameboid shape appeared in some microglia cells exposed to EMP for 1, 6 and 12 h. Moreover, the number of microglia cells with ameboid shape increased significantly at 1 h, 6 h and 12 h after EMP exposure compared with sham group (P < 0.05). The levels of cytokines, such as TNF-α, IL-1ß and IL-10, in culture supernatant did not change obviously after EMP exposure. The levels of NO and ROS increased significantly at 1h after EMP exposure, reached the peak at 6 h, began to recover at 12 h and recovered to sham group level at 24 h (P < 0.05). Western blot results showed that the protein and protein phosphorylation levels of ERK and JNK did not change significantly after EMP exposure, however, the protein and protein phosphorylation levels of p38 increased obviously at 1 h and 6 h after EMP exposure, compared with sham group (P < 0.05). In addition, the pretreatment of p38 inhibitor (SB203580) significantly decreased NO and ROS production induced by EMP. CONCLUSION: EMP exposure may activate microglia cells and promote the production of NO and ROS in mouse microglia cells, and p38 pathway is involved in this process.


Assuntos
Campos Eletromagnéticos , Microglia/citologia , Microglia/metabolismo , Animais , Linhagem Celular , Citocinas/metabolismo , Camundongos , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
20.
Artigo em Zh | MEDLINE | ID: mdl-22804884

RESUMO

OBJECTIVE: To establish the inner blood-retinal barrier (BRB) model in vitro by co-culturing RF/6A cells and C6 cells and to investigate the effects of EMP (200 kV/m, 200 pulses) exposure on the permeability of the inner BRB model in vitro. METHODS: RF/6A cells and C6 cells were co-cultured on transwell, and the characteristic of the inner BRB model was assessed by detecting transendothelial electrical resistance (TEER) and the permeability of horseradish peroxidase (HRP). The co-cultured model was exposed or sham exposed to the EMP (200 kV/m 200 pulses) for 0.5, 3, 6, 12, 24 h in vitro, then TEER and the permeability of HRP were measured for studying the effects of EMP on the permeability of inner BRB model in vitro. RESULTS: TEER value (145 Ωcm(2)) of the co-culturing inner BRB model significantly increased, as compared to that of RF/6A cells alone model (P < 0.05) on the 6th day after inoculation. There was significant difference of permeability of HRP between the co-culturing inner BRB model and RF/6A cells alone model (P < 0.05). The ability of inhibiting large molecular materials in the co-culturing inner BRB model enhanced. The TEER value decreased and the permeability of HRP increased as compared to the sham group at 0.5, 3, 6 h after the exposure. CONCLUSION: The inner BRB model by co-culturing RF/6A cells and C6 cells in vitro is efficient and suitable to study the alterations of the restricted permeability function of the inner BRB. EMP (200 kV/m for 200 pulses) could induce the enhanced permeability of the inner BRB model in vitro.


Assuntos
Barreira Hematorretiniana/fisiologia , Campos Eletromagnéticos , Células Endoteliais/fisiologia , Retina/citologia , Animais , Linhagem Celular Tumoral , Técnicas de Cocultura , Impedância Elétrica , Macaca mulatta , Permeabilidade , Ratos
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