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1.
Microbiol Spectr ; : e0234221, 2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35579464

RESUMO

Staphylococcus haemolyticus is an opportunistic pathogen associated with hospital-acquired infections. However, the genetic diversity of S. haemolyticus among the patients and the hospital environment is largely unknown. Here, we isolated 311 S. haemolyticus strains from different sampling sites of patients and hospital environment. Genomic analysis showed that ST42 is an emerging clone widely disseminated in the hospital. S. haemolyticus ST42 strains exhibited decreased susceptibilities for multiple antibiotics compared with other STs and carried significantly more antibiotic resistance genes (ARGs). Furthermore, ST42 strains harbored more virulence genes per isolate than in other STs, and the capsular biosynthesis genes capDEFG were more prevalent in ST42 strains. Using the Galleria mellonella infection model, we demonstrated that ST42 strains are highly virulent compared with non-ST42 strains. Taken together, our data identified an emerging ST42 clone of S. haemolyticus with aggregated ARGs and virulence determinants in the hospital, representing a significant health threat in terms of both disease and treatment. IMPORTANCE S. haemolyticus is an emerging opportunistic pathogen with a high burden of antimicrobial resistance. We performed molecular epidemiological analysis of S. haemolyticus that was isolated from a hospital, and found that the phylogenetic lineages are diverse accompanied by a dominant epidemic clonal lineage ST42. We demonstrated that S. haemolyticus ST42 strains have been disseminated among patients and the hospital environment. The data provide mechanistic insight and indicate that S. haemolyticus ST42 strains are multidrug-resistance and virulent clones via accumulating more ARGs and virulence genes.

2.
Biochem Biophys Res Commun ; 612: 70-76, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35504092

RESUMO

Acetaminophen (APAP) overdose induces acute liver injury (ALI), even acute liver failure (ALF). There is a significant unmet need to furtherly elucidate the mechanisms and find new therapeutic target. Recently, emerging evidence indicates that nicotinamide adenine dinucleotide (NAD+) plays a crucial role in APAP-induced ALI. Herein, we firstly investigated the protein expression of NAD kinase (NADK), as the rate-limiting enzyme converting NAD+ to nicotinamide adenine dinucleotide phosphate (NADP+), and found it was positively correlated with APAP-induced ALI in a dose- and time-dependent manner. Additionally, supplementation of N-acetylcysteine (NAC), known as an antidote of APAP, mitigated the ALI and downregulated the expression of NADK which was also in a dose-dependent manner. Moreover, pretreatment with methotrexate (MTX), the inhibitor of NADK, attenuated the levels of transaminases, alleviated morphological abnormalities, and improved oxidative stress triggered by APAP overdose, which was attributed to elevated hepatic NAD+ pool. Subsequently, the increased NAD+ upregulated the expression of Sirt1, SOD2 and attenuated DNA damage. Collectively, elevated expression of NADK is related to APAP-induced ALI, and inhibition of NADK alleviates the ALI through elevating liver NAD+ level and improving antioxidant capacity.

3.
J Phys Chem Lett ; : 4244-4250, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35522045

RESUMO

Phase junctions of photocatalysts can promote the separation of photogenerated charge carriers for efficient utilization of the carriers. Construction of phase junctions and establishing their structure-performance relationship are still required. Herein, polycrystalline TiO2 decahedral plates with different phases were synthesized by thermal treatment-induced topotactic transition of titanium oxalate crystals. The phase of TiO2 evolved from pure anatase to anatase-brookite, anatase-brookite-rutile, and then to anatase-rutile, while the morphology of the decahedral plates was well maintained. The biphase anatase-brookite was found to be most efficient in photocatalytic hydrogen generation. Specifically, the hydrogen generation rate of the biphase anatase-brookite TiO2 was nearly 2.4 times greater than that of the biphase anatase-rutile TiO2. The spatially resolved surface photovoltage measurements indicate the more efficient separation of photogenerated charge carriers and thus greater photocatalytic activity of the former. This work provides a strategy for developing efficient phase-junction photocatalysts.

4.
Biochem Biophys Res Commun ; 607: 103-109, 2022 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-35367821

RESUMO

A growing body of evidence suggests that metabolic events play essential roles in the development of liver fibrosis. Immune response gene 1 (IRG1) catalyzes the generation of itaconate, which function as a metabolic checkpoint under several pathological circumstances. In the present study, the hepatic level of IRG1 was determined in mice with carbon tetrachloride (CCl4)-induced liver fibrosis. And then the pathological significance of IRG1 and the pharmacological potential of 4-octyl itaconate (4-OI), a cell-permeable derivate of itaconate, in liver fibrosis were investigated in mice. The results indicated that the hepatic level of IRG1 was upregulated in mice with liver fibrosis. CCl4-induced formation of fibrotic septa and deposition of collagen was aggravated in IRG1 KO mice. IRG1 deletion also resulted in increased expression of transforming growth factor beta 1 (TGF-ß1), enhanced phosphorylation of Smad3, elevated level of alpha smooth muscle actin (α-SMA) and hydroxyproline, which were associated with compromised activation of nuclear erythroid 2-related factor 2 (Nrf2)-mediated antioxidant system and exacerbated oxidative stress. Interestingly, supplementation with 4-OI activated Nrf2 pathway, suppressed TGF-ß1 signaling and attenuated fibrogenesis. Our data indicated that upregulation of IRG1 might function as a protective response during the development of liver fibrosis, and 4-OI might have potential value for the pharmacological intervention of liver fibrosis.


Assuntos
Fator 2 Relacionado a NF-E2 , Fator de Crescimento Transformador beta1 , Animais , Tetracloreto de Carbono/toxicidade , Fator de Transcrição de Proteínas de Ligação GA/metabolismo , Células Estreladas do Fígado/metabolismo , Imunidade , Fígado/metabolismo , Cirrose Hepática/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
5.
J Hazard Mater ; 434: 128936, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35461002

RESUMO

Carbonate-bound uranium (U) is critical in controlling the migration of U in circumneutral to alkaline conditions. The potential release risk of carbonate-bound U should be concerned due to the contribution of mineral replacement. Herein, we explored the fate of U during the conversion process from microbial-induced calcite to hydroxylapatite (HAP) and investigated the phase and morphology evolution of minerals and the immobilization efficiency, distribution, and stability of U. The results showed that most calcite could convert to HAP during the conversion process. The aqueous residual U was below 1.0 mg/L after U-HAP formation, and the U removal efficiencies were enhanced by 20.0-74.4% compared to the calcite precipitation process. XRD and TEM results showed that the products were a mixture of HAP and uramphite. The elemental mapping results showed that most U concentrated on uramphite while a handful of U distributed homogeneously in calcite and HAP matrixes. The stability test verified that U-bearing HAP decreased the U solubility by 98-100% relative to calcite due to the uramphite formation and U incorporation into HAP. Our findings demonstrated that the combinations of microbial-induced calcite precipitation and calcite-HAP conversion could facilitate the U immobilization in treating radioactive wastewater and soil.

6.
Micromachines (Basel) ; 13(4)2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35457799

RESUMO

The dissimilar materials bonding of NiTi alloy with shape memory effect (SME) and CuSn10 alloy with good ductility, electrical conductivity, and thermal conductivity can be used in aerospace, circuits, etc. In order to integrate NiTi and CuSn10 with greatly different physical and chemical properties by selective laser melting (SLM), the effects of forming interlayers with different SLM process parameters were explored in this study. The defects, microstructure, and component diffusion at the interface were also analyzed. Columnar grain was found along the molten pool boundary of the interfacial region, and grains in the interfacial region were refined. Elements in the interfacial region had a good diffusion. Phase identifying of the interface showed that Ni4Ti3 was generated. The analysis showed that the columnar grain, refined grains in the interfacial region, and a certain amount of Ni4Ti3 could strengthen the interfacial bonding. This study provides a theoretical basis for forming NiTi/CuSn10 dissimilar materials structural members.

7.
Front Public Health ; 10: 862598, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35419331

RESUMO

It is difficult to study the intestinal damage induced by space radiation to astronauts directly, and few prediction models exist. However, we can simulate it in patients with pelvic tumor radiotherapy (RT). Radiation-induced intestinal injury (RIII) is common in cancer patients who receieved pelvic and abdominal RT. We dynamically analyzed gut microbiota and metabolites alterations in 17 cervical and endometrial cancer patients after pelvic RT. In patients who later developed grade 2 RIII, dysbiosis of gut microbiota and metabolites were observed. Univariate analysis showed that Erysipelatoclostridium and ptilosteroid A were related to the occurrence of grade 2 RIII. Notably, a strong positive correlation between gut bacteria Erysipelatoclostridium relative abundance and gut metabolite ptilosteroid A expression was found. Furthermore, combinations of Erysipelatoclostridium and ptilosteroid A could provide good diagnostic markers for grade 2 RIII. In conclusion, gut bacteria Erysipelatoclostridium and its related metabolite ptilosteroid A may collaboratively predict RIII, and could be diagnostic biomarkers for RIII and space radiation injury.


Assuntos
Microbioma Gastrointestinal , Lesões por Radiação , Bactérias , Disbiose/microbiologia , Humanos , Pregnanos
9.
Biomed Res Int ; 2022: 3227957, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35360517

RESUMO

Background: Serum chitinase-3-like protein 1 (CHI3L1) is a promising marker for diagnosing liver fibrosis. This meta-analysis was carried out to assess the diagnostic performance of serum CHI3L1 for the estimation of liver fibrosis. Methods: Systematic searches were performed on PubMed, Embase, Web of Science, Scopus, the Cochrane Library, Google Scholar, Sinomed, the China National Knowledge Infrastructure (CNKI), the Chinese Medical Journal Database, and the Wanfang databases for available studies. The primary studies were screened strictly according to inclusion and exclusion criteria, and sensitivity, specificity, and other measures of accuracy of serum CHI3L1 for evaluating liver fibrosis were pooled with 95% confidence intervals. I 2 was calculated to assess heterogeneity, and sources of heterogeneity were explored by subgroup analysis. Deeks' test was used to assess for publication bias, and likelihood ratio was used to determine posttest probability. Results: Our research integrated 11 articles, accounting for 1897 patients older than 18 years old. The pooled sensitivity and specificity for significant fibrosis, advanced fibrosis, and cirrhosis were 0.79 and 0.82 with an area under the receiver operating characteristic curve (AUC) of 0.85, 0.81 and 0.83 with an AUC of 0.91, and 0.72 and 0.74 with an AUC of 0.85, respectively. Random-effects models were used to assess for significant heterogeneity, and subgroup analysis showed that age and aetiology of included patients were likely sources of heterogeneity. No potential publication bias was found for serum CHI3L1 in the diagnosis of significant fibrosis, advanced fibrosis, or cirrhosis, and posttest probability was moderate. Conclusion: Measurement of serum CHI3L1 is a feasible diagnostic tool for liver fibrosis.


Assuntos
Quitinases , Adolescente , Proteína 1 Semelhante à Quitinase-3 , Humanos , Cirrose Hepática/diagnóstico , Curva ROC , Sensibilidade e Especificidade
10.
Chemosphere ; 299: 134286, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35304216

RESUMO

Organic acids usually compete the immobilization of As by iron (hydro)oxides, but their oxidizing effects are ignored. Therefore, the gallic acid (GA) with strong redox activity was chosen to investigate the influence of arsenite [As(III)] oxidation on As immobilization by ferrihydrite. Our results found that the As amount adsorbed on ferrihydrite decreased with the pH rising from 5 to 9 in the presence of GA, and the adsorption amount (28.8 g kg-1) at pH 9 was 45.1% lower than that in the absence of GA. Meanwhile, the As adsorption amounts in treatments of GA addition before As (Fh-GA-As(III)) were significantly lower than that in their corresponding simultaneous addition (Fh-As(III)/GA). The proportions of As(V)/Astotal on ferrihydrite and in equilibrium suspension were increased as the pH increased in the presence of GA, and the highest oxidation efficiency of As(III) by GA at pH 9 was 90.3%, which was mainly due to the contribution of hydrogen peroxide (H2O2, 52.6%) and semiquinone radicals (SQ-, 27.1%). In general, the oxidation and competition adsorption of As by GA inhibited the As immobilization by ferrihydrite, and the oxidation of As(III) by GA was strongly dependent on pH, while H2O2 and SQ- were demonstrated as the main oxidant at pH 9.


Assuntos
Arsênio , Adsorção , Compostos Férricos , Ácido Gálico , Peróxido de Hidrogênio , Compostos Orgânicos , Oxirredução
11.
Microbiol Spectr ; 10(2): e0206421, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35230154

RESUMO

Two tet(X4)-positive Enterobacter cloacae isolates TECL_1 and TECL_2 were isolated from pigs in China. S1-PFGE and Southern blotting showed that tet(X4) located on plasmids in the size of ∼290 kb and ∼190 kb in TECL_1 and TECL_2, respectively. Conjugation experiment demonstrated that the tet(X4)-harboring plasmid can transfer from the donor strain TECL_1 and TECL_2 to the recipient strain Escherichia coli J53, and the tigecycline resistance of transconjugants was increased by 128-fold and 64-fold compared with E. coli J53, respectively. We obtained the complete plasmid sequence of pTECL_2-190k-tetX4 (190,185 bp) from E. cloacae TECL_2 and found that the plasmid was a hybrid plasmid with replicon types of IncFIA, IncHI1A and IncHI1B. We further analyzed 85 tet(X4)-carrying plasmids in the public database and clarified that pTECL_2-190k-tetX4-like plasmid was widespread in multiple species of Enterobacteriaceae. IMPORTANCE We identified two tet(X4)-positive E. cloacae isolates, which has not been previously reported. We obtained the complete sequence of pTECL_2-190k-tetX4 and found that it was a hybrid plasmid with multiple replicon types, including IncFIA, IncHI1A and IncHI1B. By comparing all the known tet(X4)-carrying plasmids, we found that pTECL_2-190k-tetX4-like plasmid has been disseminated across various species in China. Our study expanded the identification of tet(X4)-positive species and emphasized that pTECL_2-190k-tetX4-like plasmid has spread widely in various species.


Assuntos
Enterobacter cloacae , Escherichia coli , Animais , Antibacterianos/farmacologia , China , Enterobacter cloacae/genética , Escherichia coli/genética , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Suínos , Tigeciclina/farmacologia
12.
BMC Genomics ; 23(1): 88, 2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35100991

RESUMO

BACKGROUND: Mobile colistin resistance like gene (mcr-like gene) is a new type of polymyxin resistance gene that can be horizontally transferred in the Enterobacteriaceae. This has brought great challenges to the treatment of multidrug-resistant Escherichia coli and K. pneumoniae. RESULTS: K. pneumoniae 16BU137 and E. coli 17MR471 were isolated from the bus and subway handrails in Guangzhou, China. K. pneumoniae 19PDR22 and KP20191015 were isolated from patients with urinary tract infection and severe pneumonia in Anhui, China. Sequence analysis indicated that the mcr-1.1 gene was present on the chromosome of E. coli 17MR471, and the gene was in the gene cassette containing pap2 and two copies of ISApl1.The mcr-1.1 was found in the putative IncX4 type plasmid p16BU137_mcr-1.1 of K. pneumoniae 16BU137, but ISApl1 was not found in its flanking sequence. Mcr-8 variants were found in the putative IncFIB/ IncFII plasmid pKP20191015_mcr-8 of K. pneumoniae KP20191015 and flanked by ISEcl1 and ISKpn26. CONCLUSION: This study provides timely information on Enterobacteriaceae bacteria carrying mcr-like genes, and provides a reference for studying the spread of mcr-1 in China and globally.


Assuntos
Proteínas de Escherichia coli , Polimixinas , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Enterobacteriaceae/genética , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Genômica , Humanos , Polimixinas/farmacologia
13.
Sci Rep ; 12(1): 1808, 2022 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-35110569

RESUMO

Epidemiological studies have indicated that natural disasters have important impacts on ischemic stroke. This study determined the associations between natural disasters and the incidence and prevalence of ischemic stroke at the global level. A 28-year ecological trend study was performed to estimate worldwide changes in the incidence and prevalence of ischemic stroke and their associations with natural disasters by analyzing data from 193 countries. Quantum geographic information system-based visualization and multivariable linear regression were used. Changes in the incidence and prevalence of ischemic stroke, as well as disaster occurrence, varied among the different regions over the past 28 years (p < 0.001). Multiple linear regression revealed an independent and positive association between disaster occurrence and the incidence of ischemic stroke in males, females and both sexes combined (standardized coefficients = 0.515, 0.470 and 0.483, p < 0.001); similar associations were found for the prevalence of ischemic stroke (standardized coefficients = 0.471, 0.417 and 0.438, p < 0.001). The incidence and prevalence of ischemic stroke changed significantly at the global level and were independently associated with natural disasters. Both males and females show common but different vulnerabilities to natural disasters. This evidence supports policy making and resource allocation for disaster response and disease burden reduction.


Assuntos
Saúde Global/tendências , AVC Isquêmico/epidemiologia , Desastres Naturais , Feminino , Humanos , Incidência , AVC Isquêmico/diagnóstico , Masculino , Prevalência , Medição de Risco , Fatores de Risco , Distribuição por Sexo , Fatores Sexuais , Fatores de Tempo
14.
Front Surg ; 9: 652806, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35223972

RESUMO

OBJECTIVE: This meta-analysis aimed to evaluate whether ketorolac administration is associated with an increased anastomotic leak rate after colorectal surgery. METHODS: The literature was searched using the Web of Science, Embase, and PubMed databases, and the search ended on May 31, 2020. The Newcastle-Ottawa Scale was used to assess methodological quality. Statistical heterogeneity was assessed using the Chi-square Q test and I 2 statistics. Subgroup analysis was performed, and Egger's test was used to assess publication bias. RESULTS: This meta-analysis included seven studies with 400,822 patients. Our results demonstrated that ketorolac administration after surgery increases the risk of anastomotic leak [OR = 1.41, 95% CI: 0.81-2.49, Z = 1.21, P = 0.23]. Low heterogeneity was observed across these studies (I 2 = 0%, P = 0.51). The results of subgroup analysis showed that the use of ketorolac in case-control and retrospective cohort studies significantly increased the risk of anastomotic leak (P < 0.05). Furthermore, the subgroup analysis revealed that ketorolac use increased anastomotic leak rate in patients in the United States and Canada, and ketorolac plus morphine use did not increase anastomotic leak rate in Taiwanese patients (P < 0.05). No significant publication bias was observed (P = 0.126). Moreover, the analysis of risk factors related to anastomotic leak rate indicated that the total use of ketorolac did not increase the risk of anastomotic leak similar to the control group (P > 0.05). CONCLUSION: The meta-analysis indicates that the use of ketorolac increases the risk of anastomotic leak after colorectal surgery. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, identifier CRD42020195724.

15.
Int J Hyperthermia ; 39(1): 358-371, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35184661

RESUMO

BACKGROUND: Hyperthermia is a widely used adjunct treatment for different cancers including nasopharyngeal carcinoma (NPC). The protooncogene c-Myc is up-regulated in NPC and its expression is associated with poor prognosis. OBJECTIVE: We hypothesized that c-Myc constitutes an important hyperthermia treatment target, and we investigated its contribution to hyperthermia responses in NPC. METHODS: The growth of the human NPC cell lines CNE1 and CNE2 was analyzed using CCK-8 and clonogenicity assays after 43 °C hyperthermia, knockdown or overexpression of c-Myc. Flow cytometry measurements assessed cell cycle parameters and apoptosis, while levels of c-Myc together with key transcriptional targets were determined using qPCR and Western blotting. Parallel experiments were undertaken using NPC xenografts in nude mice and lastly, global transcriptomic changes were determined using 'RNAseq'. RESULTS: Hyperthermia increased the ubiquitination and proteasomal destruction of c-Myc, causing a rapid decline in c-Myc protein levels in NPC cells. Similar to c-Myc knockdown, NPC cells treated with hyperthermia showed growth inhibition associated with the downregulation of c-Myc target genes. Moreover, low levels of c-Myc could be sustainably repressed in NPC cells through repeated hyperthermia treatments. Importantly, the key findings of growth inhibition and decreased c-Myc protein levels were reproduced in NPC tumor xenografts. Bioinformatic analyses showed that downregulation of c-Myc constituted a central node in the hyperthermia response of NPC cells. CONCLUSION: Our study reveals that hyperthermia can readily destabilize c-Myc levels in NPC cells and inhibit tumor growth. This proposes new strategies for implementing hyperthermia to target c-Myc-driven cancers to improve therapeutic efficacy.


Assuntos
Hipertermia Induzida , Neoplasias Nasofaríngeas , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Humanos , Camundongos , Camundongos Nus , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/terapia
16.
Vet Microbiol ; 266: 109355, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35114536

RESUMO

The source and route of bacterial colonization of the uterus are still not established. The objective was to investigate the source and route of bacterial colonization of the uterus by exploring the genetic relationship among E. coli strains isolated from the gastrointestinal and the reproductive tract of dairy cows pre- and postpartum. Secondarily, uterine health status (metritis vs. healthy) was evaluated. Cows (n = 34) had the rectoanal junction (RAJ), vulva, and vagina swabbed every three days starting six days before expected calving until nine days postpartum. The uterus was swabbed postpartum. A blood sample was collected at all time points, but cultures were negative. Whole-genome sequencing was performed on 44 isolates recovered from eight cows (four metritic and four healthy) with growth on selective E. coli media from the RAJ, vulva and/or vagina and uterus. Clonal isolates were found in the RAJ or the vulva prepartum and in the vulva, vagina or uterus postpartum. Clonal isolates were also found in the RAJ, the vulva, the vagina and the uterus postpartum. Clonal isolates were found in individual cows and different cows. Absence of clustering based on virulence factor genes and all genes indicate no strain specificity to body site or uterine health status. These findings indicate that the gastrointestinal tract is the likely source of bacteria that colonize the reproductive tract via ascending colonization of the uterus through the lower genital tract. Additionally, cow to cow transmission occurs, and strains are not specific to body site or to health status.


Assuntos
Doenças dos Bovinos , Endometrite , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Endometrite/veterinária , Escherichia coli/genética , Feminino , Trato Gastrointestinal , Período Pós-Parto , Útero/microbiologia
17.
Nanomaterials (Basel) ; 12(4)2022 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-35215033

RESUMO

A nickel-titanium (NiTi)-based intermetallic coating was in-situ synthesized on a Ti-6Al-4V (TC4) substrate via laser melting deposition (LMD) using Ni-20Cr and TC4 powders. Scanning electron microscopy, X-ray diffraction, a digital microhardness tester and an electrochemical analyzer were used to evaluate the microstructure, Vicker's microhardness and electrochemical corrosion resistance of the intermetallic coating. Results indicate that the microstructure of the intermetallic coating is composed of NiTi2, NiTi and Ni3Ti. The measured microhardness achieved is as high as ~850 HV0.2, ~2.5 times larger than that of the TC4 alloy, which can be attributed to the solid solution strengthening of Al and Cr, dispersion strengthening of the intermetallic compounds, and grain refinement strengthening from the rapid cooling of LMD. During the electrochemical corrosion of 3.5% NaCl solution, a large amount of Ti ions were released from the intermetallic coating surface and reacted with Cl- ions to form [TiCl6]2 with an increase in corrosion voltage. In further hydrolysis reactions, TiO2 formation occurred when the ratio of [TiCl6]2- reached a critical value. The in-situ synthesized intermetallic coating can achieve a superior corrosion resistance compared to that of the TC4 alloy.

18.
BMC Genomics ; 23(1): 20, 2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-34996351

RESUMO

BACKGROUND: Carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP) causes serious infections with significant morbidity and mortality. However, the epidemiology and transmission mechanisms of CR-hvKP and the corresponding carbapenem-resistant plasmids require further investigation. Herein, we have characterized an ST11 K. pneumoniae strain EBSI041 from the blood sample encoding both hypervirulence and carbapenem resistance phenotypes from a patient in Egypt. RESULTS: K. pneumoniae strain EBSI041 showed multidrug-resistance phenotypes, where it was highly resistant to almost all tested antibiotics including carbapenems. And hypervirulence phenotypes of EBSI041 was confirmed by the model of Galleria mellonella infection. Whole-genome sequencing analysis showed that the hybrid plasmid pEBSI041-1 carried a set of virulence factors rmpA, rmpA2, iucABCD and iutA, and six resistance genes aph(3')-VI, armA, msr(E), mph(E), qnrS, and sul2. Besides, blaOXA-48 and blaSHV-12 were harboured in a novel conjugative IncL-type plasmid pEBSI041-2. The blaKPC-2-carrying plasmid pEBSI041-3, a non-conjugative plasmid lacking the conjugative transfer genes, could be transferred with the help of pEBSI041-2, and the two plasmids could fuse into a new plasmid during co-transfer. Moreover, the emergence of the p16HN-263_KPC-like plasmids is likely due to the integration of pEBSI041-3 and pEBSI041-4 via IS26-mediated rearrangement. CONCLUSION: To the best of our knowledge, this is the first report on the complete genome sequence of KPC-2- and OXA-48-coproducing hypervirulent K. pneumoniae from Egypt. These results give new insights into the adaptation and evolution of K. pneumoniae during nosocomial infections.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Egito , Humanos , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Plasmídeos/genética , beta-Lactamases/genética
19.
Colloids Surf B Biointerfaces ; 211: 112318, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35007856

RESUMO

Light-triggered antibacterial therapy has been proven to be a secure and effective way to treat bacterial infection. Nevertheless, the long-term security of the common photosensitizer remains to be seen in the body. In this work, carbon dots (CDs) with good biocompatibility are incorporated into TiO2 nanorods to improve the photocatalytic and photothermal ability of titanium implants under the irradiation of visible light (VL) and near-infrared (NIR) light. The C-TiO2 NR exhibit excellent in vitro and in vivo antimicrobial effect under 660 nm VL and 808 nm NIR light co-irradiation owing to the combined effect of hyperthermia, reactive oxygen species (ROS) and nanorod structure. Besides, C-TiO2 NR can improve the adhesion and diffusion of bone marrow mesenchymal stem cells (BMSCs).


Assuntos
Hipertermia Induzida , Nanotubos , Antibacterianos/química , Antibacterianos/farmacologia , Carbono , Titânio/química , Titânio/farmacologia
20.
J Colloid Interface Sci ; 608(Pt 1): 599-604, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34628319

RESUMO

Developing high-performance electrocatalysts with favorable phase, surface structure and electronic structure for oxygen evolution reaction (OER) is crucial for efficient electrocatalytic water splitting. With Fe3+ ions as both dopant and morphology-controlling agent, Fe-doped NiS2 microcrystals with the exposed chemically stable {001} facets were synthesized hydrothermally for electrocatalytic OER. The initial electrocatalytic OER activation processes led to the conversion of iron-rich surface layers of the NiS2 microcrystals into Fe-doped Ni (oxy)hydroxide as the shell and the residual inner of the NiS2 microcrystals as the core. Such Fe-doped NiS2 microcrystals with the derived core/shell structure only required a small OER overpotential of 277 mV to reach an electrochemical current density of 10 mA/cm2, and showed a good stability in a more than 20 h duration test almost without overpotential increase.

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