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1.
Int Microbiol ; 25(3): 471-479, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35098390

RESUMO

PURPOSE: This study aims to characterize antimicrobial resistance (AMR) of all the non-duplicated Acinetobacter baumannii strains isolated from an intensive care unit in a tertiary hospital during the period of January 1 to December 31, 2015. METHODS: A. baumannii (n = 95 strains) isolated from patients was subjected to antimicrobial susceptibility test (AST) by Vitek 2 Compact system to determine minimum inhibitory concentrations, followed by genotyping by enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). Resistance genes of interest were PCR amplified and sequenced. RESULTS: All isolates were qualified as MDR, with a resistance rate of > 80% to 8 antimicrobials tested. In terms of beta-lactamase detection, the blaOXA23, blaTEM-1, and armA genes were detected frequently at 92.63%, 9 1.58%, and 88.42%, respectively. The metallo-ß-lactamase genes blaIMP and blaVIM were undetected. Aph (3')-I was detected in 82 isolates (86.32%), making it the most prevalent aminoglycoside-modifying enzyme (AMEs) encoding gene. In addition, ant (3″)-I was detected at 30.53%, while 26.32% of the strains harbored an aac (6')-Ib gene. ERIC-PCR typing suggested moderate genetic diversity among the isolates, which might be organized into 10 distinct clusters, with cluster A (n = 86 isolates or 90.53%) being the dominant cluster. CONCLUSIONS: All of the A. baumannii strains detected in the ICU were MDR clones exhibiting extremely high resistance to carbapenems and aminoglycosides as monitored throughout the study period. They principally belonged to a single cluster of isolates carrying blaOXA23 and armA co-producing different AMEs genes.


Assuntos
Acinetobacter baumannii , Acinetobacter baumannii/genética , Aminoglicosídeos/genética , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Proteínas de Bactérias/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Enterobacteriaceae , Humanos , Unidades de Terapia Intensiva , Testes de Sensibilidade Microbiana , Centros de Atenção Terciária , beta-Lactamases/genética
2.
Phys Chem Chem Phys ; 23(8): 4718-4727, 2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33596276

RESUMO

In this work, we report a comparative study of the interfacial properties of fcc-Al/L12-Al3M (M = Sc, Ti, V, Y, Zr, Nb) from first-principles calculations. It is found that the fcc-Al(111)/L12-Al3Nb(111) interface is energetically favorable because of its negative interfacial energy (-0.225 J m-2), whereas the interfacial energies of the other five interfaces are positive. Despite their thermodynamically unfavorable characteristics, the stabilities of the formed interfaces are ranked in the order fcc-Al(111)/L12-Al3Nb(111) > fcc-Al(111)/L12-Al3Ti(111) > fcc-Al(111)/L12-Al3Zr(111) > fcc-Al(111)/L12-Al3Sc(111) > fcc-Al(111)/L12-Al3V(111) > fcc-Al(111)/L12-Al3Y(111). Moreover, the computed generalized stacking fault energy curves revealed that the (111)[11-2] slip system is preferred over the (111)[10-1] slip system under external stresses for all six interfaces. Based on the Rice ratio criterion, the interface slips also energetically favor the generation of stacking faults instead of cleavage for these interface systems; this finding implied that these interfaces did not greatly influence the plastic deformation behavior of aluminum. Furthermore, the derived bulk elastic properties indicate that fcc-Al, L12-Al3Nb, and L12-Al3V tend to present ductile behavior, while L12-Al3Zr, L12-Al3Ti, L12-Al3Y, and L12-Al3Sc are found to be brittle compounds. Nevertheless, all of these intermetallics can strengthen the aluminum matrix without losing much plasticity to provide a higher elastic modulus than aluminum along with the ductile interface nature of fcc-Al(111)/L12-A13M(111).

3.
Int J Med Microbiol ; 310(1): 151379, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31759864

RESUMO

The presence of bacterial species other than the pathogen at infection site can affect the progression of a bacterial infection. Based on the fact that Citrobacter freundii can coexist during Pseudomonas aeruginosa infection, this study aims to investigate the impact of the co-existing C. freundii on the pathogenesis of P. aeruginosa infection. A murine peritonitis model was used to compare the mortality rates and histopathology of P. aeruginosaPAO1 infection in the presence and absence of a C. freundii clinical isolate C9. We also investigated the intercellular interaction between PAO1 and C9 by examining pyocyanin production and comparing gene expression levels. The results demonstrate that co-infection with C9 significantly increased the mortality rate and tissue damages in PAO1 infected mice. At an inoculum of 106 CFU, no mortality was observed in the C9 infected group at three days post-infection, whereas the mortality rate in the PAO1-C9 co-infection group was 64%, compared with 24% in the PAO1 infected group. Pyocyanin production in P. aeruginosa PAO1 increased 8 folds approximately in the presence of C. freundii C9, and operons associated with phenazine synthesis, phzA1 and phzA2, were also upregulated. Disruption of the phzA1 and phzA2 eliminated the exacerbated pathogenicity in the co-infection group, indicating that the elevated pyocyanin production was the main contributing factor. The results suggest that co-existing C. freundii during P. aeruginosa infection can exacerbate the pathogenicity, which may have significant implications in patients infected with these bacteria.


Assuntos
Coinfecção/microbiologia , Infecções por Enterobacteriaceae/microbiologia , Peritonite/microbiologia , Infecções por Pseudomonas/microbiologia , Animais , Proteínas de Bactérias/genética , Citrobacter freundii , Modelos Animais de Doenças , Masculino , Camundongos , Peritonite/mortalidade , Fenazinas/metabolismo , Pseudomonas aeruginosa , Piocianina/biossíntese , Virulência
4.
Phys Chem Chem Phys ; 21(35): 19437-19446, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31460522

RESUMO

The research into the co-segregation behavior of Sc and Zr solutes and their effect on the mechanical properties of the Al Σ5 (210) [110] grain boundary was carried out by first principles calculations. It is concluded that Sc and Zr both have a powerful driving force to segregate to the grain boundary, and based on the most negative segregation energy, first one Sc atom segregates to the grain boundary, then one Zr atom and finally another Sc atom. The grain boundary energy, strengthening/embrittling energy, fracture energy and theoretical tensile peak stress all demonstrate that Sc and Zr solutes have a strengthening effect on the grain boundary, which can be attributed to the combination of the "chemical effect" (charge density variation) and the "structural effect" (atomic arrangement change), especially the migration of the first Sc-segregated site toward the grain boundary, which not only brings stronger Sc/Zr-Al bonds instead of weak Al-Al bonds but also leads to the shrinkage and charge accumulation of the great vacuum area between two grains. This work sheds light on the underlying mechanism of the better mechanical performance due to the co-addition of Sc and Zr solutes at the atomic and electronic levels.

5.
Am J Emerg Med ; 37(9): 1760-1769, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31182360

RESUMO

OBJECTIVE: It is unclear whether point-of-care ultrasound (POCUS) by emergency medicine physicians is as accurate as radiology-performed ultrasound (RADUS). We aim to summarize the diagnostic accuracy of ultrasonography for intussusception and to compare the performance between POCUS and RADUS. METHODS: Databases were searched from inception through February 2018 using pre-defined index terms. Peer-reviewed primary studies that investigated the diagnostic accuracy of ultrasound for intussusception in children were included. The study is reported using Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA). Meta-analysis of the diagnostic accuracy of ultrasound for intussusception was conducted using the random-effects bivariate model. Subgroup analysis (POCUS vs RADUS) was also performed. Meta-regression was utilized to determine if the diagnostic accuracy between POCUS and RADUS was significantly different. RESULTS: Thirty studies (n = 5249) were included in the meta-analysis. Ultrasonography for intussusception has a sensitivity: 0.98 (95% CI: 0.96-0.98), specificity: 0.98 (95% CI: 0.95-0.99), positive likelihood ratio: 43.8 (95% CI: 18.0-106.7) and negative likelihood ratio: 0.03 (95% CI: 0.02-0.04), with an area under ROC (AUROC) curve of 0.99 (95% CI: 0.98-1.00). Meta-regression suggested no significant difference in the diagnostic accuracy for intussusception between POCUS and RADUS (AUROC: 0.95 vs 1.00, p = 0.128). CONCLUSIONS: Current evidence suggested POCUS has a high diagnostic accuracy for intussusception not significantly different from that of RADUS.


Assuntos
Intussuscepção/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito/normas , Ultrassonografia/normas , Adolescente , Área Sob a Curva , Criança , Pré-Escolar , Serviço Hospitalar de Emergência/normas , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Estudos Retrospectivos
6.
Ergonomics ; 62(3): 406-419, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30307379

RESUMO

The objective of this study is to investigate the potential of functional near-infrared spectroscopy (fNIRS) combined with heart rate variability indices, for the evaluation of the mental workload of urban rail transit drivers under simulated driving conditions, particularly during task engagement and disengagement. Experienced metro drivers wearing fNIRS monitoring systems were asked to drive for 90 min in a professional metro driving simulator. Workload stimulus tasks were added and an n-back task (n = 3) was implemented to induce workload in the simulated driving experiment. Experimental results indicate that fNIRS are sensitive to mental workload and reliable for discriminating the degree of mental workload. Research findings demonstrate the feasibility and reliability of fNIRS as a tool for real-time evaluating and monitoring driver mental workload along with task factors from a perspective of brain activations during simulated or actual driving. Practitioner Summary: This study provides evidence for the potential of functional near-infrared spectroscopy (fNIRS) for the evaluation of the mental workload of urban rail transit drivers under simulated driving conditions. The first fNIRS application to mental workload evaluation in the field of urban rail transportation helps companies develop reasonable shiftwork schedule and ensure operation safety. Abbreviations: fNIRS: functional near-infrared spectroscopy; oxy-Hb: Oxy-hemoglobin; NASA-TLX: National Aeronautics and Space Administration Task Load Index; EEG: electroencephalogram; ECG: electrocardiogram; HRV: variability; LF: low-frequency power; HF: high-frequency power; PFC: prefrontal cortex; NIRS: near-infrared spectroscopy; DWT: discrete wavelet transform; EMG: electromyography; DT: determination test; TP: total power; LFnorm: standardized LF; HFnorm: standardized HF; VLF: very low frequency; deoxy-Hb: deoxy-hemoglobin.


Assuntos
Condução de Veículo , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Carga de Trabalho , Adulto , Simulação por Computador , Feminino , Frequência Cardíaca/fisiologia , Hemoglobinas , Humanos , Masculino , Análise e Desempenho de Tarefas , Adulto Jovem
7.
J Cell Sci ; 128(22): 4196-209, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26430214

RESUMO

Nuclear receptor interaction protein (NRIP, also known as DCAF6 and IQWD1) is a Ca(2+)-dependent calmodulin-binding protein. In this study, we newly identify NRIP as a Z-disc protein in skeletal muscle. NRIP-knockout mice were generated and found to have reduced muscle strength, susceptibility to fatigue and impaired adaptive exercise performance. The mechanisms of NRIP-regulated muscle contraction depend on NRIP being downstream of Ca(2+) signaling, where it stimulates activation of both 'calcineurin-nuclear factor of activated T-cells, cytoplasmic 1' (CaN-NFATc1; also known as NFATC1) and calmodulin-dependent protein kinase II (CaMKII) through interaction with calmodulin (CaM), resulting in the induction of mitochondrial activity and the expression of genes encoding the slow class of myosin, and in the regulation of Ca(2+) homeostasis through the internal Ca(2+) stores of the sarcoplasmic reticulum. Moreover, NRIP-knockout mice have a delayed regenerative capacity. The amount of NRIP can be enhanced after muscle injury and is responsible for muscle regeneration, which is associated with the increased expression of myogenin, desmin and embryonic myosin heavy chain during myogenesis, as well as for myotube formation. In conclusion, NRIP is a novel Z-disc protein that is important for skeletal muscle strength and regenerative capacity.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Calmodulina/metabolismo , Músculo Esquelético/fisiologia , Proteínas Nucleares/metabolismo , Regeneração/fisiologia , Animais , Camundongos , Camundongos Knockout , Contração Muscular/fisiologia , Músculo Esquelético/metabolismo , Transdução de Sinais
8.
Cell Physiol Biochem ; 39(4): 1307-16, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27606686

RESUMO

BACKGROUND/AIMS: Motility is a feature of many pathogens that contributes to the migration and dispersion of the infectious agent. Whether gentamycin has a post-antibiotic effect (PAE) on the swarming and swimming motility of Escherichia coli (E. coli) remains unknown. In this study, we aimed to examine whether short-term pretreatment of sub-inhibitory concentrations of gentamycin alter motility of E. coli and the mechanisms involved therein. METHODS: After exposure to sub-inhibitory concentrations (0.8 µg/ml) of gentamicin, the swarming and swimming motility of E. coli was tested in semi-solid media. Real-time PCR was used to detect the gene expression of succinate dehydrogenase (SDH). The production of SDH and fumarate by E. coli pretreated with or without gentamycin was measured. Fumarate was added to swarming agar to determine whether fumarate could restore the swarming motility of E. coli. RESULTS: After pretreatment of E. coli with sub-inhibitory concentrations of gentamycin, swarming motility was repressed in the absence of growth inhibition. The expression of all four subunits of SDH was down-regulated, and the intracellular concentration of SDH and fumarate, produced by E. coli, were both decreased. Supplementary fumarate could restore the swarming motility inhibited by gentamycin. A selective inhibitor of SDH (propanedioic acid) could strongly repress the swarming motility. CONCLUSION: Sub-inhibitory concentrations of gentamycin inhibits the swarming motility of E. coli. This effect is mediated by a reduction in cellular fumarate caused by down-regulation of SDH. Gentamycin may be advantageous for treatment of E. coli infections.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Escherichia coli/efeitos dos fármacos , Flavoproteínas/antagonistas & inibidores , Regulação Bacteriana da Expressão Gênica , Gentamicinas/farmacologia , Subunidades Proteicas/antagonistas & inibidores , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/enzimologia , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Flavoproteínas/genética , Flavoproteínas/metabolismo , Fumaratos/metabolismo , Malonatos/farmacologia , Testes de Sensibilidade Microbiana , Movimento/efeitos dos fármacos , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Transdução de Sinais , Ácido Succínico/metabolismo , Fatores de Tempo
9.
BMC Pediatr ; 16(1): 161, 2016 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-27741941

RESUMO

BACKGROUND: Nasal colonization with bacterial pathogens is associated with risk of invasive respiratory tract infections, but the related information for Chinese healthy children is scarce. METHODS: This cross-sectional study was conducted with healthy children from 6 kindergartens in the Chaoshan region, southern China during 2011-2012. Nasal swabs were examined for five common bacterial pathogens: Streptococcus pneumoniae, Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis, and Staphylococcus aureus. RESULTS: Among 1,088 children enrolled, 79.6 % (866) were target-bacterial carriers, of which 34.4 % (298/866) were positive for ≥2 bacteria species. The most common pathogen in the bacterial carriers was M. catarrhalis (76.6 %), followed by S. pneumoniae (26.6 %), S. aureus (21.8 %), H. parainfluenzae (12.7 %), and H. influenzae (2.3 %). Multiple logistic regression analyses showed negative associations between age and the overall or multiple bacterial carriage, and between the father's education level and multiple bacterial carriage (all p < 0.05). Age was negatively associated with the carriage of M. catarrhalis and S. pneumoniae, and positively associated with the S. aureus carriage (all p < 0.0001). CONCLUSIONS: This study shows high nasal carriage of common pathogenic bacteria and coexistence of multiple pathogens in healthy Chaoshan kindergarten children, with M. catarrhalis as the commonest colonizer. Increasing age of children and higher paternal education are associated with lower risk of bacterial carriage. Longitudinal follow-up studies would be helpful for better understanding the infection risk in bacterial pathogen carriers.


Assuntos
Portador Sadio/epidemiologia , Infecções por Haemophilus/epidemiologia , Infecções por Moraxellaceae/epidemiologia , Mucosa Nasal/microbiologia , Infecções Pneumocócicas/epidemiologia , Infecções Estafilocócicas/epidemiologia , Portador Sadio/diagnóstico , Criança , Pré-Escolar , China/epidemiologia , Estudos Transversais , Feminino , Infecções por Haemophilus/diagnóstico , Haemophilus influenzae/isolamento & purificação , Haemophilus parainfluenzae/isolamento & purificação , Humanos , Masculino , Moraxella catarrhalis/isolamento & purificação , Infecções por Moraxellaceae/diagnóstico , Infecções Pneumocócicas/diagnóstico , Infecções Estafilocócicas/diagnóstico , Staphylococcus aureus/isolamento & purificação , Streptococcus pneumoniae/isolamento & purificação
10.
Cell Physiol Biochem ; 31(2-3): 347-54, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23485684

RESUMO

The number of clinical specimens containing ß-lactam-resistant Pseudomonas aeruginosa isolates is increasing. However, whether resistance is associated with reduced fitness is still uncertain in clinical Pseudomonas aeruginosa isolates. In this study, we aimed to determine whether ß-lactam resistance conferred a fitness cost in Pseudomonas aeruginosa. Growth rate, extracellular slime production, elastase activity, proteolytic activity, LasA protease activity, biofilm formation, and pairwise in vitro competition experiments were investigated in a collection of 11 isogenic, ß-lactam-susceptible and -resistant (≥8-fold increase in minimum inhibitory concentration (MIC)) pairs of P. aeruginosa clinical isolates; each pair was recovered from a different patient treated with ß-lactam antibiotics. All ß-lactam-resistant Pseudomonas aeruginosa isolates showed a significant reduction in elastase activity. In addition, 90.9% (10/11) of ß-lactam-resistant Pseudomonas aeruginosa isolates were associated with markedly lower growth rate and proteolytic activity, and 81.8% (9/11) of ß-lactam-resistant Pseudomonas aeruginosa isolates had less extracellular slime production, compared to susceptible isolates. Meanwhile, LasA protease activity and biofilm formation ability were variable among isolates. Pairwise in vitro competition experiments showed that 72.7% (8/11) of ß- lactam-susceptible strains could outgrow resistant strains. In conclusion, resistance development with ß-lactam exposure confers a fitness cost, resulting in a decreased invasion potential, while the effect on viability varied. Thus, the potential for the dissemination of ß-lactam-resistant Pseudomonas aeruginosa clinical isolates should not be underestimated.


Assuntos
Antibacterianos/farmacologia , Aptidão Genética/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Resistência beta-Lactâmica/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Metaloproteases/metabolismo , Testes de Sensibilidade Microbiana , Fenótipo , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/isolamento & purificação , Fatores de Virulência/metabolismo
11.
Materials (Basel) ; 16(9)2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37176218

RESUMO

This study systematically investigated the performance and microstructure characterization of cryogenic rolling (CR) and room-temperature rolling (RTR) Al-Mg-Si alloys. The result showed that the hardness of the CR alloys decreased at the early aging stage, but that the hardness of the RTR alloys increased at the early aging stage. Retrogression phenomena were apparent in the CR alloys at the early aging stage. Despite undergoing the same solid solution treatment, a few substructures were still observed in the CR alloys, and the degree of recrystallization in the CR alloys was significantly inferior to that in the RTR alloys. After aging for 50 h, the strength and precipitates' density in the CR 75 alloy were higher than that in the other alloys; this indicated that the substructures were beneficial to precipitation and precipitate growth. A precipitation strength model was employed to illustrate the precipitation contribution at different aging stages. The results showed that the CR 75 alloy obtained the strongest precipitation strengthening.

12.
Materials (Basel) ; 16(10)2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37241452

RESUMO

The quality of extruded profiles depends largely on accurate constitutive models and thermal processing maps. In this study, a modified Arrhenius constitutive model for homogenized 2195 Al-Li alloy with multi-parameter co-compensation was developed and further enhanced the prediction accuracy of flow stresses. Through the processing map and microstructure characterization, the 2195 Al-Li alloy could be deformed optimally at the temperature range of 710~783 K and strain rate of 0.001~0.12 s-1, preventing the occurrence of local plastic flow and abnormal growth of recrystallized grains. The accuracy of the constitutive model was verified through numerical simulation of 2195 Al-Li alloy extruded profiles with large shaped cross-sections. Dynamic recrystallization occurred at different regions during the practical extrusion process, resulting in slight variations in the microstructure. The differences in microstructure were due to the varying degrees of temperature and stress experienced by the material in different regions.

13.
Microb Drug Resist ; 29(2): 51-58, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36577022

RESUMO

Linezolid has been reported to restore erythromycin susceptibility in erythromycin-resistant Staphylococcus aureus. This phenomenon has not been reported in enterococci and the mechanisms involved therein are still unknown. The purpose of this study was to investigate the mechanisms involved and the effect of combining linezolid with erythromycin on erythromycin-resistant enterococci. Checkerboard techniques were used to determine drug interactions, and 12 of 14 isolates showed a synergistic effect between erythromycin and linezolid (fractional inhibitory concentration <0.5). We observed that the erm(B) gene, which encodes a dimethyltransferase responsible for erythromycin resistance, was expressed from transposon Tn1545 in the tested erythromycin-resistant enterococci. After exposure to linezolid, erm(B)-mediated rRNA dimethylation at A2071 could not be detected, and the erm(B) gene was lost following acquisition of erythromycin susceptibility. Thus, in conclusion, linezolid combined with erythromycin exerts a synergistic effect against erythromycin-resistant enterococci. Linezolid treatment suppressed erm(B)-mediated rRNA dimethylation at A2071, which could lead to loss of the erm(B) gene.


Assuntos
Eritromicina , Staphylococcus aureus Resistente à Meticilina , Linezolida/farmacologia , Eritromicina/farmacologia , Antibacterianos/farmacologia , Enterococcus/genética , Farmacorresistência Bacteriana/genética , Testes de Sensibilidade Microbiana , RNA Ribossômico
14.
Materials (Basel) ; 16(16)2023 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-37629881

RESUMO

The hot deformation behavior and dynamic softening mechanism of 7B50 aluminum alloy were studied via isothermal compression experiments in the range of 320-460 °C/0.001-1.0 s-1. According to the flow curves obtained from the experiments, the flow behavior of this alloy was analyzed, and the Zener-Hollomon (Z) parameter equation was established. The hot processing maps of this alloy were developed based on the dynamic material model, and the optimal hot working region was determined to be 410-460 °C/0.01-0.001 s-1. The electron backscattered diffraction (EBSD) microstructure analysis of the deformed sample shows that the dynamic softening mechanism and microstructure evolution strongly depend on the Z parameter. Meanwhile, a correlation between the dynamic softening mechanism and the lnZ value was established. Dynamic recovery (DRV) was the only softening mechanism during isothermal compression with lnZ ≥ 20. Discontinuous dynamic recrystallization (DDRX) becomes the dominant dynamic recrystallization (DRX) mechanism under deformation conditions of 15 < lnZ < 20. Meanwhile, the size and percentage of DDRXed grains increased with decreasing lnZ values. The geometric dynamic recrystallization (GDRX) mechanism and continuous dynamic recrystallization (CDRX) mechanism coexist under deformation conditions with lnZ ≤ 15.

15.
Environ Pollut ; 327: 121539, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37019259

RESUMO

Overconsumption of antibiotics is an immediate cause for the emergence of antimicrobial resistance (AMR) and antibiotic resistant bacteria (ARB), though its environmental impact remains inadequately clarified. There is an urgent need to dissect the complex links underpinning the dynamic co-evolution of ARB and their resistome and mobilome in hospital sewage. Metagenomic and bioinformatic methods were employed to analyze the microbial community, resistome and mobilome in hospital sewage, in relation to data on clinical antibiotic use collected from a tertiary-care hospital. In this study, resistome (1,568 antibiotic resistance genes, ARGs, corresponding to 29 antibiotic types/subtypes) and mobilome (247 types of mobile genetic elements, MGEs) were identified. Networks connecting co-occurring ARGs with MGEs encompass 176 nodes and 578 edges, in which over 19 types of ARGs had significant correlations with MGEs. Prescribed dosage and time-dependent antibiotic consumption were associated with the abundance and distributions of ARGs, and conjugative transfer of ARGs via MGEs. Variation partitioning analyses show that effects of conjugative transfer were most likely the main contributors to transient propagation and persistence of AMR. We have presented the first evidence supporting idea that use of clinical antibiotics is a potent driving force for the development of co-evolving resistome and mobilome, which in turn supports the growth and evolution of ARB in hospital sewage. The use of clinical antibiotics calls for greater attention in antibiotic stewardship and management.


Assuntos
Antibacterianos , Microbiota , Esgotos , Antagonistas de Receptores de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Antibacterianos/farmacologia , Bactérias/genética , Genes Bacterianos , Esgotos/microbiologia , Metagenoma
16.
J Vasc Interv Radiol ; 23(8): 1036-42, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22609290

RESUMO

PURPOSE: To evaluate the treatment efficacy of unilateral versus bilateral transarterial chemoembolization for hepatocellular carcinoma (HCC) based on whether the tumor is located across the Cantlie line within the watershed zone of the liver. MATERIALS AND METHODS: Seventy-seven patients with 87 HCCs located in the watershed zone who underwent complete chemoembolization (unilateral, n = 57 [74%]; bilateral, n = 20 [26%]) were included. Tumors located in the watershed zone were further divided into two groups: tumors across the Cantlie line (type A) and tumors not across the line (type B). Comparison of treatment outcomes of unilateral or bilateral chemoembolization for the two groups was performed. The tumor viability (ie, presence of viable component or tumor progression) and position of the viable component on follow-up computed tomography was recorded. RESULTS: Tumor viability rates for type A tumors in the unilateral and bilateral chemoembolization groups were 52.2% and 11.1%, respectively; for type B tumors, they were 23.7% and 11.8%, respectively. The tumor viability rate of type A tumors was significantly higher in the unilateral chemoembolization group than in the bilateral chemoembolization group (P = .05), but there was no significant difference for type B tumors (P > .05). CONCLUSIONS: The tumor viability rate of HCC tumors across the Cantlie line was higher with unilateral chemoembolization group than with bilateral chemoembolization. In patients with HCC across the Cantlie line, embolization of bilateral hepatic arteries may achieve better treatment efficacy.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Artéria Hepática , Neoplasias Hepáticas/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Sobrevivência Celular , Distribuição de Qui-Quadrado , Meios de Contraste , Feminino , Artéria Hepática/diagnóstico por imagem , Humanos , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Taiwan , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Carga Tumoral
17.
Materials (Basel) ; 15(22)2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-36431730

RESUMO

Fine-grained pure tungsten fabricated by a sol drying reduction low-temperature sintering method and hot isothermal compression tests were performed by using the Gleeble 3800 thermo mechanical simulator at deformation temperatures from 1273 K to 1473 K and strain rates from 0.001 s-1 to 1 s-1. In addition, the constitutive equation was established by least square method combined with the Zerilli-Armstrong model, and the hot deformation behavior was discussed. Moreover, based on constitutive equation, the influence of the rolling process and its parameters on temperature, strain, density and rolling force in the hot rolling process was investigated at elevated temperature by the finite element model (FEM). Furthermore, the form of rolling damage and its formation mechanism were analyzed. Results showed the grains of pure tungsten are dense, irregular polyhedral spherical and very fine, and the average grain size is about 5.22 µm. At a high strain rate, the flow stress increases rapidly with the increase in strain, while the stress-strain curve shows a flattening trend in the tested strain rate range with increasing temperature, and no flow stress peak exists, showing obvious dynamic recovery characteristics. Furthermore, the FEM simulation showed that compared with the rolling temperature, the reduction has a greater influence on the temperature, stress-strain field and its distribution. There are three kinds of damage in the hot rolling process: transverse cracks, longitudinal cracks and side cracks, which are attributed to the competition between additional stress caused by uneven deformation and material strength. Moreover, the control method of hot rolling defects had been preliminarily proposed. These results should be of relevance for the optimum design of the hot rolling process of pure tungsten.

18.
Healthcare (Basel) ; 10(5)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35627911

RESUMO

Placenta accreta spectrum (PAS) described the anchoring placental villi attached or penetrating into/through the myometrium. PAS is clinically important because of the unpredictable bleeding amount when manually removing the defective decidualization at the endometrial-myometrial interface. Therefore, a multidisciplinary strategy for cesarean delivery with PAS is crucial. Postoperative embolization after cesarean hysterectomy in a hybrid suite was studied by many scientists. In this study, we demonstrated two cases of intraoperative embolization without hysterectomy in a hybrid operating room for cesarean delivery with placenta accreta. Our results show that intraoperative uterine artery embolization with a hybrid suite is a time-preserving and safe method for cesarean delivery with PAS owing to avoiding the risk of morbidity and mortality during patient transfer.

19.
Cell Physiol Biochem ; 28(5): 1045-50, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22178954

RESUMO

Numerous antibiotics can induce an SOS repair system in bacteria that leads to antibiotic-resistant mutation of the bacterium. Therefore, searching for drugs that can prevent the SOS response and thus improve the long-term viability of some antibiotics is important. In this study, we aimed to detect the suppressive effects of baicalein on the SOS system and rifampin-resistant mutation in Staphylococcus aureus. We determined the reactive oxygen species (ROS) formation and intracellular ATP level in S. aureus with baicalein treatment to investigate the mechanisms involved in its effects on the SOS system. The results showed that baicalein was a potent inhibitor of the expression of the SOS genes RecA, LexA and SACOL1400. The rifampin-resistant mutation rate of S. aureus induced by ciprofloxacin was significantly reduced after treatment with baicalein. Treatment with baicalein led to a significant decrease in intracellular reactive oxygen species (ROS) formation and ATP level. Our findings indicate that baicalein may be an SOS-response inhibitor in S. aureus through inhibiting ROS formation and ATP production and may be used to prevent excessive mutation induced by antibiotics.


Assuntos
Antioxidantes/farmacologia , Ciprofloxacina/farmacologia , Flavanonas/farmacologia , Resposta SOS em Genética/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Anti-Infecciosos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Espécies Reativas de Oxigênio/metabolismo , Recombinases Rec A/genética , Recombinases Rec A/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Staphylococcus aureus/metabolismo
20.
Sci Rep ; 11(1): 13243, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34168186

RESUMO

Oesophageal cancer is the sixth leading cause of cancer death worldwide. This nationwide study analyses the survival results of oesophageal cancer under multidisciplinary team (MDT) care. We enrolled oesophageal cancer patients diagnosed between 2010 and 2015 with follow-up for at least 1 year. This study performed propensity score matching with a ratio of 1:1 between MDT participants and non-MDT participants. We performed conditional Cox proportional hazards model to research relative risk of survival and associated factors of survival. The adjusted survival curves were plotted. 8184 newly diagnosed oesophageal cancer patients were included. The favourable survival factors include participant status of MDT, gender, monthly salary, urbanization level, other catastrophic illness, stage of cancer, treatment methods, and service volume of physicians (P < 0.05). MDT participants showed lower risk of death (HR = 0.73; 95% CI 0.67-0.79). Further stratification analysis revealed that the incorporation of an MDT reduced the death risk of patients with stages 2, 3, and 4 cancer, with the greatest reduction observed in patients with stage 3 cancer (HR = 0.72; 95% CI 0.67-0.79). The risk of death was lower for oesophageal cancer patients who enrolled in MDT care.


Assuntos
Neoplasias Esofágicas/mortalidade , Comunicação Interdisciplinar , Equipe de Assistência ao Paciente , Adulto , Idoso , Neoplasias Esofágicas/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Análise de Sobrevida
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