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1.
Antimicrob Agents Chemother ; 67(11): e0081223, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37877694

RESUMO

Type II toxin-antitoxin systems are highly prevalent in bacterial genomes and play crucial roles in the general stress response. Previously, we demonstrated that the type II antitoxin PfMqsA regulates biofilm formation through the global regulator AgtR in Pseudomonas fluorescens. Here, we found that both the C-terminal DNA-binding domain of PfMqsA and AgtR are involved in bacterial antibiotic susceptibility. Electrophoretic mobility shift assay (EMSA) analyses revealed that AgtR, rather than PfMqsA, binds to the intergenic region of emhABC-emhR, in which emhABC encodes an resistance-nodulation-cell division efflux pump and emhR encodes a repressor. Through quantitative real-time reverse-transcription PCR and EMSA analysis, we showed that AgtR directly activates the expression of the emhR by binding to the DNA motif [5´-CTAAGAAATATACTTAC-3´], leading to repression of the emhABC. Furthermore, we demonstrated that PfMqsA modulates the expression of EmhABC and EmhR. These findings enhance our understanding of the mechanism by which antitoxin PfMqsA contributes to antibiotic susceptibility.


Assuntos
Antitoxinas , Pseudomonas fluorescens , Pseudomonas fluorescens/genética , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
2.
Phys Chem Chem Phys ; 25(35): 23901-23908, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37642508

RESUMO

Using the ab initio molecular metadynamics method, the adsorption of the structure of 1-hydroxyethane-1,1-diphosphonic acid (HEDP) on the Fe3O4 surface and subsequent detachment of Fe atoms from the surface were simulated, and the dissolution mechanism by which HEDP dissolves Fe3O4 scale at room temperature while other organic acids cannot was elucidated. The adsorbed hydroxyl groups, water and HEDP on the Fe3O4 surface play a synergistic role in detaching the Fe ions, which increases the coordination number of the Fe atoms and weakens the original Fe-O bond strength. In addition, the strong coordination ability and flexible molecular structure of HEDP also facilitate dissolution of Fe3O4 scale by breaking down the chemical bonds and forming Fe-HEDP complexes. The free energy surface for the dissolution reaction shows a low barrier, and the descaling reaction is easily accomplished.

3.
Malar J ; 20(1): 158, 2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33743712

RESUMO

BACKGROUND: China has accumulated considerable experience in malaria control and elimination over the past decades. Many research papers have been published in Chinese journals. This study intends to describe the development and experience of malaria control and elimination in China by quantitatively analysing relevant research using a bibliometric analysis. METHODS: A long-term, multistage bibliometric analysis was performed. Research articles published in Chinese journals from 1980 to 2019 were retrieved from the Wanfang and China National Knowledge Infrastructure (CNKI) databases. Year of publication, journal name and keywords were extracted by the Bibliographic Items Co-occurrence Matrix Builder (BICOMB). The K/A ratio (the frequency of a keyword among the total number of articles within a certain period) was considered an indicator of the popularity of a keyword in different decades. VOSviewer software was used to construct keyword co-occurrence network maps. RESULTS: A total of 16,290 articles were included. The overall number of articles continually increased. However, the number of articles published in the last three years decreased. There were two kinds of keyword frequency trends among the different decades. The K/A ratio of the keyword 'Plasmodium falciparum' decreased (17.05 in the 1980s, 13.04% in the 1990s, 9.86 in the 2000s, 5.28 in the 2010s), but those of 'imported case' and 'surveillance' increased. Drug resistance has been a continuous concern. The keyword co-occurrence network maps showed that the themes of malaria research diversified, and the degree of multidisciplinary cooperation gradually increased. CONCLUSIONS: This bibliometric analysis revealed the trends in malaria research in China over the past 40 years. The results suggest emphasis on investigation, multidisciplinary participation and drug resistance by researchers and policymakers in malaria epidemic areas. The results also provide domestic experts with qualitative evidence of China's experience in malaria control and elimination.


Assuntos
Bibliometria , Controle de Doenças Transmissíveis/estatística & dados numéricos , Erradicação de Doenças/estatística & dados numéricos , Malária/prevenção & controle , China
4.
Malar J ; 19(1): 136, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-32228585

RESUMO

BACKGROUND: Since the National Malaria Elimination Action Plan was launched in China in 2010, local malaria transmission has decreased rapidly. Zero indigenous cases were reported since 2017. However, after 2010, the proportion of imported cases in China increased from 45.7% in 2010 to 99.9% in 2016, and almost all provinces of China have reported imported cases in recent years. Prevention of the reintroduction of malaria into China is crucial for the maintenance of its malaria-free status. Hence, it is of utmost importance to correctly identify the source of malaria infections within the country. CASE INTRODUCTION AND RESPONSE: In 2016 and 2017, three laboratory-confirmed cases of malaria caused by Plasmodium falciparum were identified in patients with no previous travel history to endemic areas were reported in Jiangsu Province, China, where malaria due to P. falciparum was eliminated about 30 years ago. These were diagnosed after 41, 31 and 39 days of seeking treatment, respectively, and all of them had received blood transfusions. Further investigations indicated that two of the cases had received blood from foreign students (from Indonesia and Ghana), and the other had received blood from an individual who had worked in Equatorial Guinea. All three blood donors were traced, and found to be carrying asymptomatic P. falciparum infections by microscopic examination and PCR. Furthermore, five polymorphic microsatellite markers (C1M4, C4M62, C13M13, C14M17, and C13M63) were typed and used to link parasites from the donors with those of the transfusion-receiving patients. CONCLUSIONS: Three transfusion-transmitted malaria cases were identified in China, all of which were due to the transfusion of blood donated by individuals who had contracted malaria outside the country. These cases can provide a reference for those faced with similar challenges in malaria case identification and classification in other regions. In addition, a stricter screening policy including the use of appropriate detection methods for malaria parasites should be developed and adopted for blood donation in regions undergoing malaria elimination.


Assuntos
Doadores de Sangue/estatística & dados numéricos , Transfusão de Sangue/estatística & dados numéricos , Malária Falciparum/transmissão , Plasmodium falciparum/isolamento & purificação , Adulto , Idoso , Infecções Assintomáticas , China , Guiné Equatorial/etnologia , Feminino , Gana/etnologia , Humanos , Indonésia/etnologia , Malária Falciparum/diagnóstico , Masculino , Pessoa de Meia-Idade , Viagem
5.
Org Biomol Chem ; 18(3): 569, 2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31858091

RESUMO

Correction for 'A folate-conjugated platinum porphyrin complex as a new cancer-targeting photosensitizer for photodynamic therapy' by Mengqian Yang et al., Org. Biomol. Chem., 2019, 17, 5367-5374.

6.
Environ Microbiol ; 21(5): 1740-1756, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30680880

RESUMO

The mqsRA operon encodes a toxin-antitoxin pair that was characterized to participate in biofilm and persister cell formation in Escherichia coli. Notably, the antitoxin MqsA possesses a C-terminal DNA-binding domain that recognizes the [5'-AACCT(N)2-4 AGGTT-3'] motif and acts as a transcriptional regulator controlling multiple genes including the general stress response regulator RpoS. However, it is unknown how the transcriptional circuits of MqsA homologues have changed in bacteria over evolutionary time. Here, we found mqsA in Pseudomonas fluorescens (PfmqsA) is acquired through horizontal gene transfer and binds to a slightly different motif [5'-TACCCT(N)3 AGGGTA-3'], which exists upstream of the PfmqsRA operon. Interestingly, an adjacent GntR-type transcriptional regulator, which was termed AgtR, is under negative control of PfMqsA. It was further demonstrated that PfMqsA reduces production of biofilm components through AgtR, which directly regulates the pga and fap operons involved in the synthesis of extracellular polymeric substances. Moreover, through quantitative proteomics analysis, we showed AgtR is a highly pleiotropic regulator that influences up to 252 genes related to diverse processes including chemotaxis, oxidative phosphorylation and carbon and nitrogen metabolism. Taken together, our findings suggest the rewired regulatory circuit of PfMqsA influences diverse physiological aspects of P. fluorescens 2P24 via the newly characterized AgtR.


Assuntos
Proteínas de Bactérias/metabolismo , Pseudomonas fluorescens/metabolismo , Antitoxinas/genética , Antitoxinas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Evolução Molecular , Regulação Bacteriana da Expressão Gênica , Óperon , Pseudomonas fluorescens/genética
7.
Electrophoresis ; 40(4): 499-507, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30467879

RESUMO

Aflatoxin contamination in agricultural products poses a great threat to humans and livestock. The aim of this study was to establish a simple, rapid, highly sensitive, and inexpensive method for the simultaneous detection of aflatoxin B1 , B2 , G1 , and G2 in agricultural products. We used a vortex assisted low density solvent-microextraction (VALDS-ME) technique for sample preconcentration and sample detection was achieved with a CE-LIF method. Aflatoxins were separated in an uncoated fused-silica capillary with the MEKC mode and were excited by a 355 nm UV laser to produce native fluorescence for detection. The obtained LOD and LOQ for the four aflatoxins were in the range of 0.002-0.075 and 0.007-0.300 µg/L, respectively, and the analysis time was within 6.5 min. Using the established method, aflatoxins were screened in naturally contaminated dairy cattle feed samples including alfalfa, bran, and corn kernel. The result shows that the alfalfa and bran samples were contaminated with aflatoxins to varying degrees. Compared with other analytical techniques for aflatoxin screening in agricultural products, this CE-LIF method combined with VALDS-ME preconcentration technique is simple, rapid, highly efficient, and inexpensive.


Assuntos
Aflatoxinas/análise , Ração Animal/análise , Cromatografia Capilar Eletrocinética Micelar/métodos , Microextração em Fase Líquida/métodos , Contaminação de Alimentos/análise , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
8.
Org Biomol Chem ; 17(21): 5367-5374, 2019 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-31106316

RESUMO

A new folate-conjugated platinum porphyrin complex (Por 4) was synthesized and characterized. The singlet oxygen production of the conjugates was evaluated through a 1,3-diphenylisobenzofuran method. The targeting ability and subcellular localization of Por 4 were confirmed by confocal laser scanning microscopy in HeLa cells (overexpression of FR) as well as in A549 cells (low expression of FR). The results suggested that the modification of the carboxyl group with a porphyrin compound did not decrease the binding affinity of folic acid to FR positive cancer cells. Moreover, the MTT assay using HeLa cells and A549 cells verified the low cytotoxicity of Por 4 in the dark. Upon irradiation, Por 4 showed noticeable improvement in toxicity against cancer cells with the overexpression of FR. Upon the treatment of Por 4 at the concentration of 20 µM, the cell viability was determined as 22% and 75% for HeLa and A549 cells, respectively, indicating that the folate-conjugated platinum porphyrin complex could be a promising PDT agent for cancer with overexpression of the folate receptor.


Assuntos
Antineoplásicos/farmacologia , Ácido Fólico/farmacologia , Compostos Organoplatínicos/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Platina/farmacologia , Porfirinas/farmacologia , Células A549 , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Ácido Fólico/química , Células HeLa , Humanos , Estrutura Molecular , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Platina/química , Porfirinas/química , Oxigênio Singlete/análise , Relação Estrutura-Atividade , Células Tumorais Cultivadas
9.
Mikrochim Acta ; 186(5): 315, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-31041599

RESUMO

Manganese-doped carbon quantum dots (MnCQDs) were prepared through one-step hydrothermal method using citric acid and manganese tetraphenyl porphyrin as carbon sources in aqueous media. The structure of MnCQDs was confirmed by TEM, XRD, and XPS. The MnCQDs display a typical excitation-dependent emission behavior and exhibit bright green luminescence (with a peak at 482 nm) under UV irradiation (365 nm) and a fluorescence quantum yield of 13%. The MnCQDs can be used as a fluorescent probe for ferric ion in aqueous solution with a 220 nM detection limit. The MTT assay demonstrated the low cytotoxicity of MnCQDs towards HeLa cells. Due to the excitation-dependent emission properties, MnCQDs can be used as a multi-color (blue, green, and red) bioimaging agent in cancer cells and in living zebrafish. The application of MnCQDs as selective biosensing probe for Fe3+ was also realized in cells and zebrafish mode. Because of the existence of paramagnetic ions, MnCQDs demonstrate an enhanced magnetic resonance (MR) signal. Thus, the MnCQDs can serve as a positive contrast agent for MR imaging. Graphical abstract Schematic presentation of the preparation of luminescent manganese-doped carbon quantum dots (MnCQDs). MnCQDs showed good magnetic resonance effect and can be used as a fluorescence probe for the detection of Fe3+ in HeLa cells and zebrafish.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , Imageamento por Ressonância Magnética/métodos , Manganês/química , Pontos Quânticos/química , Fluorometria , Células HeLa , Humanos , Ferro/metabolismo
10.
J Asian Nat Prod Res ; 17(4): 415-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25363682

RESUMO

A new eremophilane norsesquiterpenoid (1), together with a known eremophilane sesquiterpenoid (2), was isolated from the leaves of Ligularia virgaurea. The structure of 1 was elucidated by a combination of spectroscopic analysis (IR, 1D NMR, 2D NMR, and HR-ESI-MS), and its absolute configuration was determined by a single-crystal X-ray diffraction experiment (with copper radiation). The known compound 2 was identified by comparison of its physical and spectral data with those reported in the literature. Compound 1 was assayed for its cytotoxic activities against human cervical carcinoma cell (HeLa) and human small cell lung cancer cell (NCI-446) lines.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Asteraceae/química , Sesquiterpenos/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos/química , Sesquiterpenos/farmacologia
11.
Malar J ; 13: 379, 2014 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-25245258

RESUMO

BACKGROUND: Anopheles sinensis is one of the most important malaria vectors in China and other Southeast Asian countries. High levels of resistance have been reported in this species due to the long-term use of insecticides, especially pyrethroids, for public health and agricultural purposes. Knockdown resistance (kdr) caused by a single base pair mutation in the gene encoding the sodium channel is strongly associated with pyrethroid insecticide resistance in many Anopheles mosquitoes. There are few methods currently available for detecting kdr mutations in An. sinensis. METHODS: A novel AllGlo probe-based qPCR (AllGlo-qPCR) method was developed to screen for the predominant kdr mutations in An. sinensis mosquitoes from the Jiangsu Province. The results from AllGlo-qPCR, allele-specific PCR (AS-PCR), and TaqMan-MGB probe-based qPCR (TaqMan-qPCR) were compared. A comparative analysis of the equipment required, ease of use and cost of the available methods was also performed. Finally, the AllGlo-qPCR method was used to detect the frequencies of kdr mutations from the other four provinces in central China. RESULTS: Six kdr genotypes were detected in An. sinensis from the Jiangsu Province by DNA sequencing. The AllGlo-qPCR method detected all of the kdr genotypes with a high level of accuracy (97% sensitivity and 98% specificity). AllGlo-qPCR correctly determined the kdr genotypes of 98.73% of 158 An. sinensis samples, whereas TaqMan-qPCR and AS-PCR correctly identified 96.84% and 88.61% of mutations, respectively. Furthermore, the AllGlo-qPCR method is simpler to perform, requires less equipment, and exhibits a moderate expense cost comparing with the other tested methods of kdr mutation detection. Samples collected from four of the other provinces in central China showed a high frequency of kdr mutation in An. sinensis, as detected by the established AllGlo-qPCR method. CONCLUSION: The novel AllGlo-qPCR method developed for kdr mutation detection in An. sinensis exhibits greater specificity and sensitivity than currently available methods and is more cost-effective; therefore, it represents a useful tool for entomological surveillance.


Assuntos
Anopheles/efeitos dos fármacos , Anopheles/genética , Resistência a Inseticidas/genética , Técnicas de Sonda Molecular , Reação em Cadeia da Polimerase/métodos , Animais , Sequência de Bases , China , Genótipo , Dados de Sequência Molecular , Mutação , Sensibilidade e Especificidade
12.
Mar Pollut Bull ; 205: 116637, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38955090

RESUMO

Metal materials undergo severe corrosion in eutrophic environments. The effect of DO decay stimulated by high concentrations of nitrogen and phosphorus pollutants on microorganisms leads to the coupling of electrochemical and microbial corrosion processes. However, there are few studies on microbial corrosion mechanisms in eutrophic environments. This article discusses the corrosive factors of marine eutrophication, summarizes the impact of marine eutrophication on microbial corrosion and the potential mechanisms, including aerobic biofilm corrosion, aerobic & anaerobic mixed biofilm corrosion, and anaerobic microbial electron transfer corrosion, and expounds on the research methods for microbial corrosion of materials serving in estuarine areas prone to pollution. Microbial prevention and control, such as nutrient restriction and microbial interspecies competition, are of research value in the field of green protection. Microbial corrosion mechanisms studies in marine eutrophication environments are significant for environment monitor development, water intake and algae control technologies, and corrosion protection in polluted environments.


Assuntos
Biofilmes , Eutrofização , Corrosão , Água do Mar/química , Água do Mar/microbiologia
13.
Front Med (Lausanne) ; 11: 1436000, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39309678

RESUMO

Background: The clinical efficacy of reverse shoulder arthroplasty (RSA), hemiarthroplasty (HA), and non-surgical management in the treatment of proximal humeral fractures (PHFs) is inconclusive. This systematic review and meta-analysis compared the clinical outcomes of arthroplasty and non-surgical management of PHFs. Methods: The databases of PubMed, Embase, Web of Science, and Cochrane Library were searched on 5 May 2023 for studies comparing arthroplasty and non-surgical treatment of PHFs. Both randomized controlled trials (RCTs) and non-randomized controlled trials (nRCTs), were included. Standard methodological quality assessments were conducted for both types of studies. The primary outcome was the Constant-Murley Score (CMS) after surgical or non-surgical treatment. Secondary study outcomes included the visual analog scale (VAS), range of motion, and complications. All functional scores and complications were subjected to subgroup and sensitivity analyses. Results: A total of four RCTs and six nRCTs were included in this study, which provided 508 patients in total for meta-analysis: 238 treated with arthroplasty and 270 treated non-surgically, of which 83 were treated with HA and 155 with RSA. All relevant information was collected, including functional scores, VAS, range of motion, and complications. The study found no significant difference in functional outcomes (mean difference, 2.82; 95% confidence interval, -0.49 to 6.14; P = 0.10; I 2 = 77%) and complications (mean difference, 1.08; 95% confidence interval, 0.51-2.25; P = 0.85; I 2 = 47%) between arthroplasty and non-surgical treatment. Both RCTs and nRCTs showed the same results. However, VAS scores were significantly lower in surgical treatment compared to non-surgical treatment. Subgroup and sensitivity analyses showed that RSA could achieve better functional scores than non-surgical treatment (mean difference, 6.00; 95% confidence interval, 1.97-10.03; P = 0.004; I 2 = 0%), while the results for HA were not significant (P > 0.05). Conclusion: There were no significant differences in complications between arthroplasty and non-surgical treatment for PHFs. RSA could achieve better functional results than non-surgical treatment, while HA could only achieve better forward flexion.

14.
Int J Pharm ; : 124744, 2024 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-39317244

RESUMO

The combination of chemotherapy and ferroptosis therapy can greatly improve the efficiency of tumor treatment. However, ferroptosis-based therapy is limited by the unsatisfactory Fenton activity and insufficient H2O2 supply in tumor cells. In this work, a nano-drug delivery system Cur@DOX@MOF-199 NPs was constructed to combine ferroptosis and apoptosis by loading curcumin (Cur) and doxorubicin (DOX) based on the copper-based organic framework MOF-199. Cur@DOX@MOF-199 NPs decompose quickly by glutathione (GSH), releasing Cu2+, DOX and Cur. Cu2+ can deplete GSH while also being reduced to Cu+; DOX can induce apoptosis and simultaneously boost H2O2 production. Moreover, Cur enhanced the expression of intracellular heme oxygenase-1 (HO-1), for decomposing heme and releasing Fe2+, which further combined with Cu+ to catalyze H2O2 for hydroxyl radical (OH) generation, leading to the accumulation of lipid peroxide and ferroptosis. As a result, Cur@DOX@MOF-199 NPs exhibited significantly enhanced antitumor efficacy in MCF-7 tumor-bearing mouse model, suggesting this nano formulation is an excellent synergetic pathway for apoptosis and ferroptosis.

15.
Materials (Basel) ; 17(14)2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39063815

RESUMO

Microbial contamination in aircraft fuel-containing systems poses significant threats to flight safety and operational integrity as a result of microbiologically influenced corrosion (MIC). Regular monitoring for microbial contamination in these fuel systems is essential for mitigating MIC risks. However, the frequency of monitoring remains a challenge due to the complex environmental conditions encountered in fuel systems. To investigate the impact of environmental variables such as water content, oxygen levels, and temperature on the MIC of aluminum alloy in aircraft fuel systems, orthogonal experiments with various combinations of these variables were conducted in the presence of sulfate-reducing bacteria. Among these variables, water content in the fuel oil demonstrated the most substantial influence on the corrosion rate of aluminum alloys, surpassing the effects of oxygen and temperature. Notably, the corrosion rate of aluminum alloys was the highest in an environment characterized by a 1:1 water/oil ratio, 0% oxygen, and a temperature of 35 °C. Within this challenging environment, conducive to accelerated corrosion, changes in the corrosion behavior of aluminum alloys over time were analyzed to identify the time point at which MIC intensified. Observations revealed a marked increase in the depth and width of corrosion pits, as well as in the corrosion weight-loss rate, starting from the 7th day. These findings offer valuable insights for determining the optimal frequency of microbial contamination detection in aircraft fuel systems.

16.
Int J Biol Macromol ; 278(Pt 2): 134885, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39168193

RESUMO

Nanocomposite polymer coatings are being used as a new generation of marine antibiofouling coatings because of their toxin-free chemical composition and ease of large-scale adoption. Cellulose nanocrystal (CN) exhibits significant potential for composite reinforcement. Herein, CN was surface-modified via α,ω-bis(3-(2-hydroxyl-terminated polydimethylsiloxane (HTPDMS), resulting in dihydroxyl-terminated poly(dimethylsiloxane)-grafted CN (HP-g-CN). The amine-terminated PDMS as the foundational component was sequentially reacted with isophorone diisocyanate, isophthalaldehyde, and carbon disulfide to produce PDMS-based poly (urea-thiourea-imine) (PDMS-PUTI). Subsequently, a composite (PDMS-PUTI/HP-g-CN) was produced through physical blending. The intrinsic imine bonds and dynamic hydrogen-bonding network were responsible for the self-healing properties, which achieved a healing efficiency of up to 89.2 %. HP-g-CN was grafted with the non-leaching lubricant, HTPDMS, resulting in improved mechanical properties (1.38 MPa of ultimate strength) and adhesion strength (2.43 MPa), along with the self-cleaning and self-lubricating performance (0.700 coefficient) of the coating. Additionally, the fouling resistance to bovine serum albumin (BSA, 10.44 µg cm-2), bacteria (∼97.08 % and âˆ¼ 98.05 % reduction for Pseudomonas sp. (P. sp.) and Shewanella sp. (S. sp.), respectively), and diatoms (∼27 cells mm-2) was further enhanced. Marine field tests conducted over 90 days revealed that the coatings were static fouling-resistant for an extended period. This study demonstrated a multifunctional, high-performance, and environmentally friendly nanocomposite polymer coating for preventing marine biofouling.


Assuntos
Incrustação Biológica , Celulose , Nanopartículas , Celulose/química , Nanopartículas/química , Incrustação Biológica/prevenção & controle , Polímeros/química , Silicones/química , Nanocompostos/química , Dimetilpolisiloxanos/química , Animais , Organismos Aquáticos/química
17.
Insect Sci ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38511329

RESUMO

Mosquitoes (Anopheles sinensis), widely geographically distributed in Asia including China, are the primary vector of the malaria parasite Plasmodium vivax and other parasitic diseases such as Malayan filariasis. An. sinensis can survive through low winter temperatures. Aquaporin channels are found in all life forms, where they facilitate environmental adaptation by allowing rapid trans-cellular movement of water (classical aquaporins) or water and solutes such as glycerol (aquaglyceroporins). Here, we identified and characterized 2 aquaporin (AQP) homologs in An. sinensis: AsAQP2 (An. sinensis aquaglyceroporin) and AsAQP4 (An. sinensis aquaporin). When expressed in frog (Xenopus laevis) oocytes, AsAQP2 transported water, glycerol, and urea; AsAQP4 transported only water. Water permeation through AsAQP2 and AsAQP4 was inhibited by mercuric chloride. AsAQP2 expression was slightly higher in adult female mosquitoes than in males, and AsAQP4 expression was significantly higher in adult males. The 2 AsAQPs were highly expressed in Malpighian tubules and midgut. AsAQP2 and AsAQP4 expression was up-regulated by blood feeding compared with sugar feeding. At freezing point (0 °C), the AsAQP4 expression level increased and An. sinensis survival time reduced compared with those at normal temperature (26 °C). At low temperature (8 °C), the AsAQP2 and AsAQP4 expression levels decreased and survival time was significantly longer compared with those at 26 °C. These results suggest that AsAQP2 and AsAQP4 have roles in water homeostasis during blood digestion and in low temperature adaptation of A. sinensis. Together, our results show that the 2 AQPs are important for mosquito diuresis after blood feeding and when exposed to low temperatures.

18.
BMC Genomics ; 14: 276, 2013 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-23617778

RESUMO

BACKGROUND: Tibial dyschondroplasia (TD) is a common skeletal disorder in broiler chickens. It is characterized by the presence of a non-vascularized and unmineralized cartilage in the growth plate. Previous studies have investigated differential expression of genes related to cartilage development during latter stages of TD. The aim of our study was to identify differentially expressed genes (DEGs) in the growth plate of broiler chickens, which were associated with early stage TD. We induced TD using tetramethylthiuram disulfide (thiram) for 1, 2, and 6 days and determined DEGs with chicken Affymetrix GeneChip assays. The identified DEGs were verified by quantitative polymerase chain reaction (qPCR) assays. RESULTS: We identified 1630 DEGs, with 82, 1385, and 429 exhibiting at least 2.0-fold changes (P < 0.05) at days 1, 2, and 6, respectively. These DEGs participate in a variety of biological processes, including cytokine production, oxidation reduction, and cell surface receptor linked signal transduction on day 1; lipid biosynthesis, regulation of growth, cell cycle, positive and negative gene regulation, transcription and transcription regulation, and anti-apoptosis on day 2; and regulation of cell proliferation, transcription, dephosphorylation, catabolism, proteolysis, and immune responses on day 6. The identified DEGs were associated with the following pathways: neuroactive ligand-receptor interaction on day 1; synthesis and degradation of ketone bodies, terpenoid backbone biosynthesis, ether lipid metabolism, JAK-STAT, GnRH signaling pathway, ubiquitin mediated proteolysis, TGF-ß signaling, focal adhesion, and Wnt signaling on day 2; and arachidonic acid metabolism, mitogen-activated protein kinase (MAPK) signaling, JAK-STAT, insulin signaling, and glycolysis on day 6. We validated seven DEGs by qPCR. CONCLUSIONS: Our findings demonstrate previously unrecognized changes in gene transcription associated with early stage TD. The DEGs we identified by microarray analysis will be used in future studies to clarify the molecular pathogenic mechanisms of TD. From these findings, potential pathways involved in early stage TD warrant further investigation.


Assuntos
Osteocondrodisplasias/genética , Doenças das Aves Domésticas/genética , Animais , Galinhas/genética , Regulação para Baixo , Lâmina de Crescimento/crescimento & desenvolvimento , Lâmina de Crescimento/patologia , Carne , Osteocondrodisplasias/induzido quimicamente , Osteocondrodisplasias/metabolismo , Análise Serial de Proteínas , Tiram , Tíbia/patologia , Transcriptoma
19.
Zhonghua Yi Xue Za Zhi ; 93(28): 2200-4, 2013 Jul 23.
Artigo em Zh | MEDLINE | ID: mdl-24169328

RESUMO

OBJECTIVE: To explore the clinical patterns and clinical significance for RET screening in adrenal pheochromocytoma (PHEO) associated with multiple endocrine neoplasia type 2A (MEN2A). METHODS: The clinical data of 32 PHEO patients with MEN2A from 13 unrelated MEN2A pedigrees from August 1989 to January 2013 were analyzed. The comprehensive medical data included systemic examinations and germline RET gene screening. RESULTS: Among 68 patients belonging to 13 MEN2A families, 32 (47.1%) presented with PHEO. There were 19 males and 13 females with a mean age of (41 ± 12) years. And the mean maximum diameter of PHEO was (4.6 ± 2.2) cm. The diagnosis of PHEO was made after medullary thyroid carcinoma (n = 12, 37.5%), simultaneously (n = 12, 37.5%), initially (n = 7, 21.9%) and death during appendectomy for PHEO-induced hypertensive crisis (n = 1, 3.1%). The diagnosis of PHEO was made before (n = 22) or after (n = 10) clinical screening. The former had 12 symptomatic cases while the latter only 1 case (12/22 vs 1/10, P = 0.024).Except for 5 asymtomatic fatal cases during non-PHEO operations, bilateral PHEO was found in 17 cases including 3 unilaterally treated cases developing another PHEO in contralateral adrenal with a lag period of 5, 10 and 17 years. There were 7 symptomatic patients in bilateral cases versus 6 in unilateral cases (7/17 vs 6/10, P = 0.440). Twenty-five patients underwent PHEO surgery: laparascopic approach in 14 cases (8 with bilateral simultaneous adrenalectomy) and open approach in 11 (2 with bilateral simultaneous adrenalectomy). And 10 patients undergoing bilateral adrenal-sparing operations or adrenalectomy required hormonal replacement therapy. During a mean observation period of 72 (1-282) months, no local recurrence, distant metastasis or Addisonian crisis were noted in 25 cases (contralateral relapse in 3 cases). Among them, 2 cases developed adrenocortical insufficiency unresponsive to an adjustment of hormonal doses.RET screening showed 4 recurrent missense substitutions in 32 MEN2A-PHEO patients: p. C634Y exon 11 (n = 27, 84.4%), p. C634R exon 11 (n = 3, 9.4%), p. C634F exon 11 (n = 1, 3.1%) and p. C618R exon 10 (n = 1, 3.1%). CONCLUSIONS: The mutations of RET proto-oncognene of PHEO in MEN2A are frequently located at codon 634. A combination of pedigree examination and RET gene screening may facilitate an early diagnosis and early treatment of asymptomatic PHEO patients in MEN2A.Laparoscopic cortical-sparing adrenalectomy for preserving adrenocortical function is a preferred surgical approach.


Assuntos
Neoplasias das Glândulas Suprarrenais/metabolismo , Neoplasia Endócrina Múltipla Tipo 2a/metabolismo , Proteínas Proto-Oncogênicas c-ret/metabolismo , Adrenalectomia , Éxons , Feminino , Humanos , Masculino , Mutação , Feocromocitoma , Proto-Oncogene Mas
20.
Bioelectrochemistry ; 154: 108539, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37579554

RESUMO

Deterioration corrosion occurs between the external surface of oil pipelines and aerobic oil-degrading microorganisms in oil fields. Microorganisms with aerobic oil pollution remediation capabilities may catalyze more serious anaerobic microbial corrosion due to the carbon source supply. In this study, Acinetobacter soli strains were isolated from oil-contaminated environments, and their role in the deterioration corrosion behavior of X70 steel in an oil-water environment was investigated using the EDS multipoint scanning method. The presence of oil controls the deposition of carbon and phosphorus and diffusion of oxygen, leading to significant adhesion attraction and initial growth inhibition of biofilm on the metal surface. A. soli facilitates oxygen transfer and iron ion dissolution, thereby accelerating the pitting corrosion of X70 steel. This corrosion of the X70 steel, in turn, further accelerates the microbial degradation of oil, inhibiting the appearance of calcareous scale in the later stage of corrosion. The corrosion of X70 steel is influenced by microbial degradation, and the specific corrosion behaviors are related to the activity of A. soli in the petroleum environment. This study sheds light on the corrosion mechanisms of X70 steel by A. soli at different stages, providing insights into the interactions between microorganisms, oil pollution, and metal corrosion in oil fields.


Assuntos
Biofilmes , Aço , Corrosão , Carbono , Água
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