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1.
Biochem Genet ; 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37962691

RESUMEN

An increasing number of circRNAs have been found to be involved in the development of gastric cancer. However, the function of circ_0003789 in regulating gastric cancer progression is unclear. Here, we aimed to investigate the expression, function and molecular mechanism of circ_0003789 in gastric cancer pathogenesis. Circ_0003789, miR-429 and ZFP36 ring finger protein like 2 (ZFP36L2) mRNA were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was illustrated by 5-Ethynyl-2'-deoxyuridine (Edu), cell counting kit-8 (CCK-8) and colony formation assays. Apoptosis was determined by flow cytometry. Protein level was detected by Western blotting assay. Xenograft assays were used for functional analysis of circ_0003789 in vivo. The relationship between miR-429 and circ_0003789 or ZFP36L2 was predicted by starbase3.0 online database and identified by dual luciferase reporter assay. The expression levels of circ_0003789 and ZFP36L2 were significantly upregulated in gastric cancer tissues and cells, while the expression of miR-429 was downregulated. Downregulation of circ_0003789 inhibited gastric cancer cell growth and invasion and promoted apoptosis in vitro. Circ_0003789 acted as a sponge of miR-429. Moreover, miR-429 silencing by miR-429 inhibitors attenuated the effects of circ_0003789 interference on cell growth, apoptosis and invasion. ZFP36L2 was targeted by miR-429, and the effects of miR-429 on cell growth, invasion and apoptosis were attenuated by ZFP36L2 overexpression. Circ_0003789 could enhance ZFP36L2 expression by interacting with miR-429. Silencing of circ_0003789 inhibited tumor growth in vivo. Circ_0003789 regulates tumor progression in gastric cancer through miR-429/ZFP36L2 axis. This finding implies that circ_0003789 may be a therapeutic target for gastric cancer.

2.
Int J Mol Sci ; 24(2)2023 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-36674715

RESUMEN

Staphylococcus aureus Cas9 (SaCas9) is a widely used genome editing tool. Understanding its molecular mechanisms of DNA cleavage could effectively guide the engineering optimization of this system. Here, we determined the first cryo-electron microscopy structure of the SaCas9-sgRNA-DNA ternary complex. This structure reveals that the HNH nuclease domain is tightly bound to the cleavage site of the target DNA strand, and is in close contact with the WED and REC domains. Moreover, it captures the complete structure of the sgRNA, including the previously unresolved stem-loop 2. Based on this structure, we build a full-length model for the ternary complex in cleavage state. This model enables identification of the residues for the interactions between the HNH domain and the WED and REC domains. Moreover, we found that the stem-loop 2 of the sgRNA tightly binds to the PI and RuvC domains and may also regulate the position shift of the RuvC domain. Further mutagenesis and molecular dynamics simulations supported the idea that the interactions of the HNH domain with the WED and REC domains play an important role in the DNA cleavage. Thus, this study provides new mechanistic insights into the DNA cleavage of SaCas9 and is also useful for guiding the future engineering of SaCas9-mediated gene editing systems.


Asunto(s)
Sistemas CRISPR-Cas , ARN Guía de Sistemas CRISPR-Cas , Microscopía por Crioelectrón , ADN/química , Edición Génica
3.
Opt Lett ; 46(23): 5790-5793, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34851891

RESUMEN

In this Letter, we propose an approach to generate high-purity orbital angular momentum (OAM) vortex waves using an amplitude-and-phase metasurface (APM). By varying the square split ring opening and orientation angles, the cross-polarized reflection response of the proposed structure can yield full phase and amplitude coverage. Based on the traditional phase-only metasurface (POM), the Chebyshev synthesis method (CSM) is applied to array the metasurface amplitude distribution. Metasurfaces with modes l of 1, 2, 3, and 4 are designed. Compared with the POM, the APM can effectively improve the vortex beam quality and OAM mode purity. The measured results agree well with full-wave simulations. The presented method provides a new, to the best of our knowledge, way to design high-purity OAM generators based on metasurfaces.

4.
Neurourol Urodyn ; 37(8): 2470-2479, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29917258

RESUMEN

OBJECTIVES: The present work evaluated preventive effect of curcumin on cisplatin-induced bladder cystopathy. METHODS: Fifteen female rats were divided into (i) Control group administered with physiological saline solution for 5 days; (ii) Cis-P group injected with cisplatin (6 mg/kg); and (iii) Cis-Cur group given cisplatin (6 mg/kg) with curcumin for 5 consecutive days. The function of bladder was measured by means of urodynamic analysis. Furthermore, hematoxylin-eosin staining and Masson trichrome staining were performed for morphological analysis. The cell apoptosis was evaluated through terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and flow cytometry. The expression of nerve growth factor (NGF), NF-E2-related factor 2, and hemeoxygenase-1 (HO-1) levels were measured through Western blotting. RESULTS: Urodynamic assay and histopathological manifestations revealed that curcumin ameliorated the bladder dysfunction induced by cisplatin. The level of cisplatin-induced apoptosis in the bladder decreased following curcumin treatment. Also, the increased protein expression of NGF indicated that the curcumin could offer neuroprotection for bladder against cisplatin. Curcumin also activated NRF2, and elevated the expression of HO-1, but curcumin could not rescue cisplatin-induced apoptosis in the cell lines with knockdown of NRF2. CONCLUSIONS: Taken together, the results of this paper showed that curcumin could ameliorate cisplatin-induced cystopathy and inhibit the apoptosis of bladder cell in cisplatin-treated rats. This may be attributed to curcumin's broad biological functions, particularly antioxidant effect, and to its ability to activate the NRF2 protein.


Asunto(s)
Antineoplásicos , Antioxidantes/uso terapéutico , Cisplatino , Curcumina/uso terapéutico , Factor 2 Relacionado con NF-E2/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Enfermedades de la Vejiga Urinaria/inducido químicamente , Enfermedades de la Vejiga Urinaria/tratamiento farmacológico , Animales , Apoptosis/efectos de los fármacos , Femenino , Técnicas de Silenciamiento del Gen , Hemo-Oxigenasa 1/metabolismo , Etiquetado Corte-Fin in Situ , Ratas , Ratas Sprague-Dawley , Vejiga Urinaria/patología , Vejiga Urinaria/fisiopatología , Enfermedades de la Vejiga Urinaria/patología , Urodinámica/efectos de los fármacos
5.
Appl Microbiol Biotechnol ; 102(10): 4243-4253, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29560521

RESUMEN

Bacteriocins are ribosomally synthesised small antimicrobial peptides produced from a wide range of bacteria, and also rich sources for potential alternatives to traditional antibiotics. Many bacteriocins have highly specific antibacterial activity against target pathogens, even including drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. As the final and essential step during biosynthesis, the leader sequence removal and exportation of matured bacteriocin are lacking of research and therefore the last to be understood. In respect of production, bacteriocin precursor peptides are processed and exported by a group of membrane proteins from the ATP-binding cassette transporter family. The main aims of this article are to summarise knowledge till now on the leader signal and correlated transporters for bacteriocin secretion in gram-positive bacteria in a review for the first time, to introduce different strategies for higher production, and to offer new insights into many essential but still unanswered questions above for the purpose of more efficient bacteriocin utilisation.


Asunto(s)
Bacteriocinas/metabolismo , Bacterias Grampositivas/fisiología , Antibacterianos/farmacología , Bacteriocinas/genética , Bacteriocinas/farmacología , Química Farmacéutica/tendencias , Proteínas de Transporte de Membrana/metabolismo , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos
6.
Appl Microbiol Biotechnol ; 102(2): 763-772, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29167920

RESUMEN

Lantibiotic nukacin ISK-1 is produced by Staphylococcus warneri ISK-1. The dual functional transporter NukT, an ABC transporter maturation and secretion protein, contributes to cleavage of the leader peptide from the prepeptide (modified NukA) and the final transport of nukacin ISK-1. NukT consists of an N-terminal peptidase domain (PEP), a C-terminal nucleotide-binding domain (NBD), and a transmembrane domain (TMD). In this study, NukT and its peptidase-inactive mutant were expressed, purified, and reconstituted into liposomes for analysis of their peptidase and ATPase activities. The ATPase activity of the NBD region was shown to be required for the peptidase activity of the PEP region. Furthermore, we demonstrated for the first time that leader peptide cleavage by the PEP region significantly enhanced the ATPase activity of the NBD region. Taken together, the presented results offer new insights into the processing mechanism of lantibiotic transporters and the necessity of interdomain cooperation.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Adenosina Trifosfatasas/metabolismo , Bacteriocinas/biosíntesis , Procesamiento Proteico-Postraduccional , Señales de Clasificación de Proteína , Transportadoras de Casetes de Unión a ATP/genética , Adenosina Trifosfatasas/genética , Proteínas Bacterianas/metabolismo , Transporte Biológico , Liposomas/metabolismo , Proteínas de la Membrana/metabolismo , Mutación , Unión Proteica , Staphylococcus/genética , Staphylococcus/metabolismo
7.
J Nanosci Nanotechnol ; 16(4): 4191-4, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27451785

RESUMEN

Carbon nanotubes were unzipped to become reduced-graphene nanoribbons via one-step solvothermal process in a Teflon-lined autoclave. The samples were characterized by X-ray diffraction, thermo-gravimetric analysis and transmission electrical microscopy, respectively. Results showed that the solvothermal reaction temperature played an important role in the structure of the samples. When it was 75 °C, carbon nanotubes were completely cutted into graphene oxide nanoribbons. Moreover, when it was 155 °C, they were become reduced-graphene nanoribbons. Furthermore, the as-prepared reduced-graphene nanoribbons could improve mechanical strength of the phenolic resin/hollow glass beads foamed composites. When the reduced-graphene nanoribbons loading was 0.4 wt%, the tensile and compressive strength of the composites were increased by 19.7% and 21.3%, respectively.


Asunto(s)
Cristalización/métodos , Grafito/química , Nanopartículas/química , Nanopartículas/ultraestructura , Calor , Ensayo de Materiales , Oxidación-Reducción , Tamaño de la Partícula , Solventes/química , Propiedades de Superficie
8.
Molecules ; 21(3): 374, 2016 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-26999101

RESUMEN

Non-small-cell lung cancer (NSCLC) dominates over 85% of all lung cancer cases. Epidermal growth factor receptor (EGFR) activating mutation is a common situation in NSCLC. In the clinic, molecular-targeting with Gefitinib as a tyrosine kinase inhibitor (TKI) for EGFR downstream signaling is initially effective. However, drug resistance frequently happens due to additional mutation on EGFR, such as substitution from threonine to methionine at amino acid position 790 (T790M). In this study, we screened a traditional Chinese medicine (TCM) compound library consisting of 800 single compounds in TKI-resistance NSCLC H1975 cells, which contains substitutions from leucine to arginine at amino acid 858 (L858R) and T790M mutation on EGFR. Attractively, among these compounds there are 24 compounds CC50 of which was less than 2.5 µM were identified. We have further investigated the mechanism of the most effective one, Digitoxin. It showed a significantly cytotoxic effect in H1975 cells by causing G2 phase arrest, also remarkably activated 5' adenosine monophosphate-activated protein kinase (AMPK). Moreover, we first proved that Digitoxin suppressed microtubule formation through decreasing α-tubulin. Therefore, it confirmed that Digitoxin effectively depressed the growth of TKI-resistance NSCLC H1975 cells by inhibiting microtubule polymerization and inducing cell cycle arrest.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Glicósidos Cardíacos/administración & dosificación , Digitoxina/administración & dosificación , Resistencia a Antineoplásicos/genética , Microtúbulos/efectos de los fármacos , Proteínas Quinasas Activadas por AMP/biosíntesis , Apoptosis/efectos de los fármacos , Carcinoma de Pulmón de Células no Pequeñas/genética , Glicósidos Cardíacos/química , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Digitoxina/química , Resistencia a Antineoplásicos/efectos de los fármacos , Receptores ErbB/biosíntesis , Receptores ErbB/genética , Gefitinib , Regulación Neoplásica de la Expresión Génica , Humanos , Medicina Tradicional China , Microtúbulos/patología , Mutación , Quinazolinas/uso terapéutico , Tubulina (Proteína)/biosíntesis , Tubulina (Proteína)/genética
9.
World J Gastrointest Surg ; 16(1): 173-185, 2024 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-38328335

RESUMEN

BACKGROUND: Recently, research has linked Helicobacter pylori (H. pylori) stomach infection to colonic inflammation, mediated by toxin production, potentially impacting colorectal cancer occurrence. AIM: To investigate the risk factors for post-colon polyp surgery, H. pylori infection, and its correlation with pathologic type. METHODS: Eighty patients who underwent colon polypectomy in our hospital between January 2019 and January 2023 were retrospectively chosen. They were then randomly split into modeling (n = 56) and model validation (n = 24) sets using R. The modeling cohort was divided into an H. pylori-infected group (n = 37) and an H. pylori-uninfected group (n = 19). Binary logistic regression analysis was used to analyze the factors influencing the occurrence of H. pylori infection after colon polyp surgery. A roadmap prediction model was established and validated. Finally, the correlation between the different pathological types of colon polyps and the occurrence of H. pylori infection was analyzed after colon polyp surgery. RESULTS: Univariate results showed that age, body mass index (BMI), literacy, alcohol consumption, polyp pathology type, high-risk adenomas, and heavy diet were all influential factors in the development of H. pylori infection after intestinal polypectomy. Binary multifactorial logistic regression analysis showed that age, BMI, and type of polyp pathology were independent predictors of the occurrence of H. pylori infection after intestinal polypectomy. The area under the receiver operating characteristic curve was 0.969 [95% confidence interval (95%CI): 0.928-1.000] and 0.898 (95%CI: 0.773-1.000) in the modeling and validation sets, respectively. The slope of the calibration curve of the graph was close to 1, and the goodness-of-fit test was P > 0.05 in the two sets. The decision analysis curve showed a high rate of return in both sets. The results of the correlation analysis between different pathological types and the occurrence of H. pylori infection after colon polyp surgery showed that hyperplastic polyps, inflammatory polyps, and the occurrence of H. pylori infection were not significantly correlated. In contrast, adenomatous polyps showed a significant positive correlation with the occurrence of H. pylori infection. CONCLUSION: Age, BMI, and polyps of the adenomatous type were independent predictors of H. pylori infection after intestinal polypectomy. Moreover, the further constructed column-line graph prediction model of H. pylori infection after intestinal polypectomy showed good predictive ability.

10.
World J Gastrointest Endosc ; 16(6): 318-325, 2024 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-38946854

RESUMEN

BACKGROUND: At present, laparoscopic cholecystectomy (LC) is the main surgical treatment for gallstones. But, after gallbladder removal, there are many complications. Therefore, it is hoped to remove stones while preserving the function of the gallbladder, and with the development of endoscopic technology, natural orifice transluminal endoscopic surgery came into being. AIM: To compare the quality of life, perioperative indicators, adverse events after LC and transgastric natural orifice transluminal endoscopic gallbladder-preserving surgery (EGPS) in patients with gallstones. METHODS: Patients who were admitted to The First Affiliated Hospital of Xinjiang Medical University from 2020 to 2022 were retrospectively collected. We adopted propensity score matching (1:1) to compare EGPS and LC patients. RESULTS: A total of 662 cases were collected, of which 589 cases underwent LC, and 73 cases underwent EGPS. Propensity score matching was performed, and 40 patients were included in each of the groups. In the EGPS group, except the gastrointestinal defecation (P = 0.603), the total score, physical well-being, mental well-being, and gastrointestinal digestion were statistically significant compared with the preoperative score after surgery (P < 0.05). In the LC group, except the mental well-being, the total score, physical well-being, gastrointestinal digestion, the gastrointestinal defecation was statistically significant compared with the preoperative score after surgery (P < 0.05). When comparing between groups, gastrointestinal defecation had significantly difference (P = 0.002) between the two groups, there was no statistically significant difference in the total postoperative score and the other three subscales. In the surgery duration, hospital stay and cost, LC group were lower than EGPS group. The recurrence factors of gallstones after EGPS were analyzed: and recurrence was not correlated with gender, age, body mass index, number of stones, and preoperative score. CONCLUSION: Whether EGPS or LC, it can improve the patient's symptoms, and the EGPS has less impact on the patient's defecation. It needed to, prospective, multicenter, long-term follow-up, large-sample related studies to prove.

11.
Materials (Basel) ; 17(9)2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38730893

RESUMEN

Metakaolin-based geopolymers have substantial potential as replacements for cement, but their relatively inferior mechanical properties restrict their application. This paper aims to enhance the mechanical properties of metakaolin-based geopolymers by incorporating appropriate amounts of calcium sources. CaCO3, Ca(OH)2, and CaSO4 are three types of calcium sources commonly found in nature and are widely present in various industrial wastes. Thus, the effects of these three calcium sources on the performance of metakaolin-based geopolymers were studied. Through the analysis of the mechanical properties, heat-release behavior during hydration, hydration products, and microstructure of geopolymers, the effectiveness of the aforementioned calcium sources in improving the performance of metakaolin-based geopolymer was evaluated, and the mechanisms of action were elucidated. The results indicate that the pozzolanic reaction between CH and MK could promote MK hydration and increase the proportion of CASH gel in the hydration products, thereby facilitating the setting of the geopolymer and enhancing its strength. CS could react with the active aluminates in MK to form ettringite, thus forming a higher early strength. CC had a lower reactivity with MK and does not improve the performance of MK-based geopolymers.

12.
Adv Sci (Weinh) ; 11(5): e2305152, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38044308

RESUMEN

Hand gesture plays an important role in many circumstances, which is one of the most common interactive methods in daily life, especially for disabled people. Human-machine interaction is another popular research topic to realize direct and efficient control, making machines intelligent and maneuverable. Here, a special human-machine interaction system is proposed and namedas computer-vision (CV) based gesture-metasurface interaction (GMI) system, which can be used for both direct beam manipulations and real-time wireless communications. The GMI system first needs to select its working mode according to the gesture command to determine whether to perform beam manipulations or wireless communications, and then validate the permission for further operation by recognizing unlocking gesture to ensure security. Both beam manipulation and wireless communication functions are validated experimentally, which show that the GMI system can not only realize real-time switching and remote control of different beams through gesture command, but also communicate with a remote computer in real time by translating the gesture language to text message. The proposed non-contact GMI system has the advantages of good interactivity, high flexibility, and multiple functions, which can find potential applications in community security, gesture-command smart home, barrier-free communications, and so on.

13.
Aging Cell ; 23(3): e14057, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38044573

RESUMEN

Aging is a complex biological process leading to impaired functions, with a variety of hallmarks. In the testis of Drosophila, the terminal epithelium region is involved in spermatid release and maturation, while its functional diversity and regulatory mechanism remain poorly understood. In this study, we performed single-cell RNA-sequencing analysis (scRNA-seq) to characterize the transcriptomes of terminal epithelium in Drosophila testes at 2-, 10 and 40-Days. Terminal epithelium populations were defined with Metallothionein A (MtnA) and subdivided into six novel sub-cell clusters (EP0-EP5), and a series of marker genes were identified based on their expressions. The data revealed the functional characteristics of terminal epithelium populations, such as tight junction, focal adhesion, bacterial invasion, oxidative stress, mitochondrial function, proteasome, apoptosis and metabolism. Interestingly, we also found that disrupting genes for several relevant pathways in terminal epithelium led to male fertility disorders. Moreover, we also discovered a series of age-biased genes and pseudotime trajectory mediated state-biased genes during terminal epithelium aging. Differentially expressed genes during terminal epithelium aging were mainly participated in the regulation of several common signatures, e.g. mitochondria-related events, protein synthesis and degradation, and metabolic processes. We further explored the Drosophila divergence and selection in the functional constraints of age-biased genes during aging, revealing that age-biased genes in epithelial cells of 2 Days group evolved rapidly and were endowed with greater evolutionary advantages. scRNA-seq analysis revealed the diversity of testicular terminal epithelium populations, providing a gene target resource for further systematic research of their functions during aging.


Asunto(s)
Drosophila , Testículo , Animales , Masculino , Testículo/metabolismo , Drosophila/genética , Transcriptoma/genética , Envejecimiento/genética , Epitelio
14.
Mol Biotechnol ; 65(8): 1346-1358, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36577835

RESUMEN

Growing evidence has suggested that lncRNAs play a significant role in the development of colorectal adenocarcinoma. LncRNA LINC02535 was a potential novel lncRNA marker of neoplastic processes of the colon. Nevertheless, the function and mechanisms of LINC02535 in colorectal adenocarcinoma remain unclear. Proteins levels were measured by western blotting. EdU, CCK-8, Transwell, and wound healing assays were performed to investigate the function of LINC02535 in colorectal adenocarcinoma. The distribution of LINC02535 in cells was evaluated by subcellular fractionation assay. The interaction among RNAs was identified by luciferase reporter and RIP assays. In this study, our findings revealed that LINC02535 was highly expressed in colorectal adenocarcinoma cells. Knockdown of LINC02535 inhibited colorectal adenocarcinoma cell proliferation, migration, and invasion. Mechanistically, LINC02535 bound with miR-30d-5p and worked as a competing endogenous RNA to facilitate the expression of messenger RNA chromodomain helicase DNA-binding protein 1 (CHD1). miR-30d-5p directly targeted the sequence of CHD1 3'-untranslated region. Notably, CHD1 upregulation abolished the suppressive influence of LINC02535 inhibition on the malignant phenotypes of colorectal adenocarcinoma cells. Overall, it was disclosed that LINC02535 played an oncogenic role in colorectal adenocarcinoma progression by sponging miR-30d-5p to upregulate CHD1 expression.


Asunto(s)
Adenocarcinoma , Neoplasias Colorrectales , MicroARNs , ARN Largo no Codificante , Humanos , Adenocarcinoma/genética , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Neoplasias Colorrectales/genética , ADN Helicasas/genética , Proteínas de Unión al ADN/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , MicroARNs/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo
15.
Chemosphere ; 338: 139516, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37454983

RESUMEN

This study was conducted on a full-scale (500 t/d) municipal solid waste incinerator (MSWI), investigating the influence of different loads on the emission of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD/Fs) and their removal by selective catalytic reduction (SCR) system. The total concentration of PCDD/Fs at the SCR inlet under 100% load was higher than that under 80% load. The changing loads caused different distribution characteristics of PCDD/Fs at the SCR inlet, and the dominant congeners changed from high-chlorinated PCDDs (80% load) to low-chlorinated PCDFs (100% load). Moreover, the increased load enhanced the removal efficiency of PCDD/Fs by SCR from 17.3% to 64.2%, which was influenced by the inlet PCDD/F distribution and the moisture content. The high-chlorinated PCDD/Fs with the more stable structure were more difficult to be deteriorated and the high moisture content can weaken the catalytic activity of SCR catalysts. Correlation analysis was used to study the relationship between major air pollutants and PCDD/F emissions. The results showed that HCl positively correlated with PCDD/F emission concentrations, while NOx and SO2 negatively correlated. The results of this study can provide a reference for MSWI to operate properly under variable loads.


Asunto(s)
Contaminantes Atmosféricos , Dibenzodioxinas Policloradas , Dibenzodioxinas Policloradas/análisis , Residuos Sólidos/análisis , Incineración , Dibenzofuranos/análisis , Contaminantes Atmosféricos/análisis , Dibenzofuranos Policlorados/análisis
16.
Bioeng Transl Med ; 8(6): e10540, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38023724

RESUMEN

The management of infected wounds is still an intractable challenge in clinic. Development of antibacterial wound dressing is of great practical significance for wound management. Herein, a natural-derived antibacterial drug, tannic acid (TA), was incorporated into the electrospun polyvinyl alcohol (PVA) fiber (TA/PVA fiber, 952 ± 40 nm in diameter). TA worked as a cross-linker via hydrogen bonding with PVA to improve the physicochemical properties of the fiber and to reach a sustained drug release (88% release of drug at 48 h). Improved mechanical property (0.8-1.2 MPa) and computational simulation validated the formation of the hydrogen bonds between TA and PVA. Moreover, the antibacterial and anti-inflammatory characteristics of TA laid the foundation for the application of TA/PVA fiber in repairing infected wounds. Meanwhile, in vitro studies proved the high hemocompatibility and cytocompatibility of TA/PVA fiber. Further in vivo animal investigation showed that the TA/PVA fiber promoted the repair of infected wound by inhibiting the bacterial growth, promoting granulation formation, and collagen matrix deposition, accelerating angiogenesis, and inducing M2 macrophage polarization within 14 days. All the data demonstrated that the TA cross-linked fiber would be a potent dressing for bacteria-infected wound healing.

17.
Materials (Basel) ; 15(22)2022 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-36431370

RESUMEN

The individual coupling processes of two-phase materials are controlled to some extent by damage theory. However, the existing theory is not sufficient to explain the effect of pore pressure on mortar materials under freeze-thaw action. In order to predict the resistance of saturated mortars during rapid cooling and to describe the physical behavior of the pore structure, the authors derived in detail the governing equations of saturated mortars during freezing in the framework of the pore elasticity theory and analyzed the sensitivity of physical parameters to the influence of temperature stresses by means of stress-strain calculations. In addition, the effects of phase change and latent heat of freezing on the local thermodynamic equilibrium are considered, and a mathematical model is established for quantitatively simulating the temperature distribution of the specimen. This model is reformulated and extended in the current work to intuitively reveal the effect of concrete dimensions on the temperature hysteresis effect. The results of the numerical model calculations show that during the freezing process, for the specimen with dimensions of 50 mm × 50 mm × 50 mm and a water-cement ratio of 0.6, the maximum temperature difference from center to surface is 10 °C, the maximum vertical strain on the surface is 4.27 × 10-4, and the maximum pore water pressure at the center of the specimen is 76 MPa. The model calculation results present a similar pattern to the physical interpretation and reference results, thus effectively evaluating the freezing damage process of saturated mortar.

18.
Carbohydr Polym ; 281: 119017, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35074133

RESUMEN

Bacterial infections on open wounds have always been a threat to human health. Herein, we prepared a silver (Ag)-polydopamine (PDA)/bacterial cellulose (BC)-chitosan (CTS) film using biological self-generation and in situ reduction. CTS was added to culture medium to allow BC to intertwine with CTS during film formation. Silver nitrate was reduced in situ to Ag nanoparticles under ultraviolet irradiation, and the nanoparticles were well dispersed in the BC-CTS film with the help of PDA, which worked synergistically with the CTS. The Ag-PDA/BC-CTS film was enriched in functional groups, and it had good tensile and swelling properties. The inhibition film demonstrated broad-spectrum inhibition of Gram-positive and Gram-negative bacteria, and this inhibition was maintained at more than 80% after 48 h of continuous use. The good biocompatibility of the film was verified using NIH3T3 fibroblasts. The results suggested that the Ag-PDA/BC-CTS film inhibited the growth of harmful bacteria while having little effect on healthy cells.


Asunto(s)
Quitosano , Nanopartículas del Metal , Animales , Antibacterianos/farmacología , Bacterias , Celulosa/farmacología , Quitosano/farmacología , Bacterias Gramnegativas , Bacterias Grampositivas , Humanos , Nanopartículas del Metal/toxicidad , Ratones , Pruebas de Sensibilidad Microbiana , Células 3T3 NIH , Plata/farmacología
19.
Carbohydr Polym ; 257: 117671, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33541624

RESUMEN

It is difficult to obtain stable multifunctional silver-containing materials that are suitable for use as wound dressings. To solve this problem, we added graphene oxide (GO) to an acetobacter culture medium and used a biological blending self-growth method to fix GO onto the bacterial cellulose to form a mixed-growth film. We then used polydopamine to fix AgNPs to obtain a novel silver-based cellulose wound dressing. This composite material was characterized by infrared spectroscopy, electron microscopy, and X-ray diffractometry, and the results showed that silver nanoparticles uniformly covered the material surface, while graphene was wrapped in a layer of bacterial cellulose. This composite film was conductive and produced a weak current, and it generated heat when a voltage was applied. This allowed it to accelerate wound cell migration and promote wound healing. In addition, AgNPs immobilized on the surface released Ag+, which generated a large number of oxidizing free radicals that killed and bacteria. The in vitro cytotoxicity tests showed that the Ag-pDA/BC (rGO) composite film has excellent biocompatibility, giving it good application prospects for wound dressings.


Asunto(s)
Celulosa/química , Fibroblastos/metabolismo , Grafito/química , Nanopartículas del Metal/química , Plata/química , Cicatrización de Heridas/efectos de los fármacos , Animales , Materiales Biocompatibles , Biopelículas , Conductividad Eléctrica , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Radicales Libres , Gluconacetobacter xylinus , Técnicas In Vitro , Ratones , Células 3T3 NIH , Nanopartículas/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
20.
Vet Med Sci ; 7(6): 2250-2259, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34455709

RESUMEN

BACKGROUND: In highly intensive dairy farms, cows often suffer from metabolic disorders that cause severe oxidative stress. OBJECTIVES: This study aimed to observe correlations and associations of oxidative stress-related indicators with milk compositions and metabolites. METHODS: Twenty-two multiparous Holstein dairy cows in early lactation were randomly selected from a commercial dairy farm. The morning milk was collected for composition and metabolites analysis. Blood was sampled via the tail vein to analyze oxidative stress-related indicators (reactive oxygen species, ROS; catalase, CAT; superoxide dismutase, SOD; glutathione peroxidase, GPX; malondialdehyde, MDA) and metabolites. RESULTS: Results showed that ROS were positively correlated with CAT, GPX, SOD, and MDA. However, the levels of CAT, GPX, and SOD were negatively related to milk fat (P  <  0.05). Nineteen serum and 7 milk metabolites were selected from detectable metabolites according to their correlations with ROS, CAT, GPX, and SOD (P  <  0.05). Metabolic pathway analysis and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database revealed that these metabolites are primarily involved in the metabolic pathways of carbohydrates and amino acids. CONCLUSIONS: This study gave us a better understanding on oxidative stress that ROS not only increased oxidative damage (MDA) in dairy cows, but also altered some metabolites involved in amino acid and carbohydrate metabolism.


Asunto(s)
Lactancia , Leche , Animales , Antioxidantes/metabolismo , Bovinos , Femenino , Leche/metabolismo , Estrés Oxidativo , Superóxido Dismutasa/metabolismo
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