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1.
Int J Biol Macromol ; 275(Pt 1): 133643, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38964680

RESUMEN

In this study, the effects of different ultrasonic treatment intensities (57, 170, and 283 W/cm2) on the chemical composition, molecular chain characteristics, crystal structure, micromorphology, interfacial adsorption behavior and emulsifying properties of sugar beet pectin (SBP) were investigated. Ultrasonic treatment did not change the types of SBP monosaccharides, but it had impacts on their various monosaccharide contents. Moreover, the feruloylated, acetyl, and methoxy groups of SBP also undergo varying degrees of changes. The increase in ultrasonic treatment intensity led to transition in the molecular chain conformation of SBP from rigid semi-flexible chains to flexible chains, accompanied by modification in its crystal structure. Microstructural analysis of SBP confirmed the significant change in molecular chain conformation. Modified SBP could form an elastic interfacial film with higher deformation resistance on the oil-water interface. The SBP sample modified with 170 W/cm2 exhibited better emulsifying properties owing to its better interfacial adsorption behavior. Moreover, the emulsions prepared with modified SBP exhibited better stability capability under different environmental stresses (pH value, salt ion concentration, heating temperature and freeze-thaw treatment). The results revealed that the ultrasonic technology is useful to improve the emulsifying properties of SBP.


Asunto(s)
Beta vulgaris , Pectinas , Beta vulgaris/química , Pectinas/química , Emulsiones/química , Ondas Ultrasónicas , Adsorción , Conformación Molecular , Concentración de Iones de Hidrógeno
2.
Front Microbiol ; 15: 1388651, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39077736

RESUMEN

Objectives: To investigate the genetic characteristics and transmission mechanism of the NDM-1-, IMP-4-, and SHV-12-producing multidrug-resistant (MDR) clinical isolate, Citrobacter freundii BC73. Methods: C. freundii BC73 was isolated from a urine specimen of a urological patient diagnosed with bladder cancer at a Chinese teaching hospital. Antimicrobial susceptibility testing was carried out using DL-120E susceptibility cards and DL-96A system. Whole genome sequencing (WGS) of the isolate was performed using the Illumina and Oxford Nanopore platforms to analyze the genetic context of drug resistance genes and plasmid characteristics. The phylogenetic tree was constructed and visualized by KSNP3.0 software and iTOL5.0 online database. Results: C. freundii isolate BC73 co-carrying bla NDM-1, bla IMP-4 and bla SHV-12 were multidrug-resistant. bla NDM-1 and bla IMP-4 were located on a novel IncFIB-like plasmid, pCFBC1, and an IncN-IncU hybrid plasmid, pCFBC2, respectively. The transferability of bla NDM-1 and bla IMP-4 from C. freundii BC73 to E. coli J53 was successfully demonstrated. The genetic context of the bla NDM-1 and bla IMP-4 genes were ISCR27-groEL-∆groES-cutA-dsbD-trpF-ble MBL-bla NDM-1-∆ISAba125-IS3000 and intI1-bla IMP-4-Kl.pn.13-mobC-IS6100, respectively. Additionally, two extensive transposition units (MGE1 in pCFBC1, MGE2 in pCFBC2) were identified and numerous antimicrobial resistance genes were discovered on it. Conclusion: To our knowledge, our study represents the first characterization of a ST22 C. freundii isolate co-harboring bla NDM-1, bla IMP-4, and bla SHV-12, obtained from a urine sample. The dissemination of this MDR isolate should be of close concern in future clinical surveillance.

3.
Sci Rep ; 14(1): 14418, 2024 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-38909136

RESUMEN

This study aimed to investigate the epidemiological characteristics and trends over time of carbapenemase-producing (e.g., KPC, NDM, VIM, IMP, and OXA-48) Gram-negative bacteria (CPGNB). Non-duplicated multi-drug resistant Gram-negative bacteria (MDRGNB) were collected from the First Affiliated Hospital of Zhengzhou University from April 2019 to February 2023. Species identification of each isolate was performed using the Vitek2 system and confirmed by matrix-assisted laser desorption ionization-time of flight mass spectrometry according to the manufacturer's instructions. PCR detected carbapenem resistance genes in the strains, strains carrying carbapenem resistance genes were categorized as CPGNB strains after validation by carbapenem inactivation assay. A total of 5705 non-repetitive MDRGNB isolates belonging to 78 different species were collected during the study period, of which 1918 CPGNB were validated, with the respiratory tract being the primary source of specimens. Epidemiologic statistics showed a significant predominance of ICU-sourced strains compared to other departments. Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii, and Pseudomonas aeruginosa were the significant CPGNB in Henan, and KPC and NDM were the predominant carbapenemases. Carbapenem-resistant infections in Henan Province showed an overall increasing trend, and the carriage of carbapenemase genes by CPGNB has become increasingly prevalent and complicated. The growing prevalence of CPGNB in the post-pandemic era poses a significant challenge to public safety.


Asunto(s)
Proteínas Bacterianas , Bacterias Gramnegativas , Infecciones por Bacterias Gramnegativas , beta-Lactamasas , beta-Lactamasas/genética , beta-Lactamasas/metabolismo , China/epidemiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Humanos , Bacterias Gramnegativas/genética , Bacterias Gramnegativas/enzimología , Bacterias Gramnegativas/efectos de los fármacos , Infecciones por Bacterias Gramnegativas/microbiología , Infecciones por Bacterias Gramnegativas/epidemiología , Masculino , Femenino , Pruebas de Sensibilidad Microbiana , Adulto , Persona de Mediana Edad , Carbapenémicos/farmacología , Antibacterianos/farmacología , Anciano , Farmacorresistencia Bacteriana Múltiple/genética , Niño , Adolescente , Preescolar , Adulto Joven , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/aislamiento & purificación , Acinetobacter baumannii/genética , Acinetobacter baumannii/enzimología , Acinetobacter baumannii/efectos de los fármacos , Lactante
4.
Angew Chem Int Ed Engl ; : e202410833, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38923633

RESUMEN

We herein describe the first example of ligand-controlled, copper-catalyzed regiodivergent asymmetric difunctionalization of terminal alkynes through a cascade hydroboration and hydroallylation process. The catalytic system, consisting of (R)-DTBM-Segphos and CuBr, could efficiently achieve asymmetric 1,1-difunctionalization of aryl terminal alkynes, while ligand switching to (S,S)-Ph-BPE could result in asymmetric 1,2-difunctionalization exclusively. In addition, alkyl substituted terminal alkynes, especially industrially relevant acetylene and propyne, were also valid feedstocks for asymmetric 1,1-difunctionalization. This protocol is characterized by good functional group tolerance, a broad scope of substrates (>150 examples), and mild reaction conditions. We also showcase the value of this method in the late-stage functionalization of complicated bioactive molecules and simplifying the synthetic routes toward the key intermediacy of natural product (bruguierol A). Mechanistic studies combined with DFT calculations provide insight into the mechanism and origins of this ligand-controlled regio- and stereoselectivity.

5.
Int J Biol Macromol ; 264(Pt 1): 130606, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38447830

RESUMEN

Chickpea protein isolate (CPI) typically exhibits limited emulsifying properties under various food processing conditions, including pH variations, different salt concentrations, and elevated temperatures, which limits its applications in the food industry. In this study, CPI-citrus pectin (CP) conjugates were prepared through the Maillard reaction to investigate the influence of various CP concentrations on the structural and emulsifying properties of CPI. With the CPI/CP ratio of 1:2, the degree of graft reached 35.54 %, indicating the successful covalent binding between CPI and CP. FT-IR and intrinsic fluorescence spectroscopy analyses revealed alterations in the secondary and tertiary structures of CPI after glycosylation modification. The solubility of CPI increased from 81.39 % to 89.59 % after glycosylation. Moreover, freshly prepared CPI emulsions showed an increase in interfacial protein adsorption (70.33 % to 92.71 %), a reduction in particle size (5.33 µm to 1.49 µm), and a decrease in zeta-potential (-34.9 mV to -52.5 mV). Simultaneously, the long-term stability of the emulsions was assessed by employing a LUMiSizer stability analyzer. Furthermore, emulsions prepared with CPI:CP 1:2 exhibited excellent stability under various environmental stressors. In conclusion, the results of this study demonstrate that the glycosylation is a valuable approach to improve the emulsifying properties of CPI.


Asunto(s)
Cicer , Pectinas , Reacción de Maillard , Espectroscopía Infrarroja por Transformada de Fourier , Emulsiones/química , Emulsionantes/química
6.
Neuroscience ; 545: 31-46, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38460903

RESUMEN

Traumatic brain injury (TBI) is a prevalent form of cranial trauma that results in neural conduction disruptions and damage to synaptic structures and functions. Cannabidiol (CBD), a primary derivative from plant-based cannabinoids, exhibits a range of beneficial effects, including analgesic, sedative, anti-inflammatory, anticonvulsant, anti-anxiety, anti-apoptotic, and neuroprotective properties. Nevertheless, the effects of synaptic reconstruction and the mechanisms underlying these effects remain poorly understood. TBI is characterized by increased levels of tumor necrosis factor-alpha (TNF-α), a cytokine integral for the modulation of glutamate release by astrocytes. In the present study, the potential of CBD in regulating aberrant glutamate signal transmission in astrocytes following brain injury, as well as the underlying mechanisms involved, were investigated using immunofluorescence double staining, enzyme-linked immunosorbent assay (ELISA), western blot analysis, hematoxylin and eosin (H&E) staining, Nissl staining, transmission electron microscopy, and RT-qPCR. In this study, we examined the impact of CBD on neuronal synapses, focusing on the TNF-α-driven purinergic signaling pathway. Specifically, our research revealed that CBD pretreatment effectively reduced the secretion of TNF-α induced by astrocyte activation following TBI. This reduction inhibited the interaction between TNF-α and P2Y1 receptors, leading to a decrease in the release of neurotransmitters, including Ca2+ and glutamate, thereby initiating synaptic remodeling. Our study showed that CBD exhibits significant therapeutic potential for TBI-related synaptic dysfunction, offering valuable insights for future research and more effective TBI treatments. Further exploration of the potential applications of CBD in neuroprotection is required to develop innovative clinical strategies.


Asunto(s)
Astrocitos , Lesiones Traumáticas del Encéfalo , Cannabidiol , Transducción de Señal , Sinapsis , Factor de Necrosis Tumoral alfa , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Animales , Cannabidiol/farmacología , Lesiones Traumáticas del Encéfalo/metabolismo , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Lesiones Traumáticas del Encéfalo/patología , Factor de Necrosis Tumoral alfa/metabolismo , Transducción de Señal/efectos de los fármacos , Sinapsis/efectos de los fármacos , Sinapsis/metabolismo , Masculino , Ratas Sprague-Dawley , Ácido Glutámico/metabolismo , Fármacos Neuroprotectores/farmacología , Plasticidad Neuronal/efectos de los fármacos , Plasticidad Neuronal/fisiología , Ratas , Ratones
7.
BMC Microbiol ; 24(1): 64, 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38373913

RESUMEN

BACKGROUND: Multi-drug-resistant organisms (MDROs) in gram-negative bacteria have caused a global epidemic, especially the bacterial resistance to carbapenem agents. Plasmid is the common vehicle for carrying antimicrobial resistance genes (ARGs), and the transmission of plasmids is also one of the important reasons for the emergence of MDROs. Different incompatibility group plasmid replicons are highly correlated with the acquisition, dissemination, and evolution of resistance genes. Based on this, the study aims to identify relevant characteristics of various plasmids and provide a theoretical foundation for clinical anti-infection treatment. METHODS: 330 gram-negative strains with different antimicrobial phenotypes from a tertiary hospital in Henan Province were included in this study to clarify the difference in incompatibility group plasmid replicons. Additionally, we combined the information from the PLSDB database to elaborate on the potential association between different plasmid replicons and ARGs. The VITEK mass spectrometer was used for species identification, and the VITEK-compact 2 automatic microbial system was used for the antimicrobial susceptibility test (AST). PCR-based replicon typing (PBRT) detected the plasmid profiles, and thirty-three different plasmid replicons were determined. All the carbapenem-resistant organisms (CROs) were tested for the carbapenemase genes. RESULTS: 21 plasmid replicon types were detected in this experiment, with the highest prevalence of IncFII, IncFIB, IncR, and IncFIA. Notably, the detection rate of IncX3 plasmids in CROs is higher, which is different in strains with other antimicrobial phenotypes. The number of plasmid replicons they carried increased with the strain resistance increase. Enterobacterales took a higher number of plasmid replicons than other gram-negative bacteria. The same strain tends to have more than one plasmid replicon type. IncF-type plasmids tend to be associated with MDROs. Combined with PLSDB database analysis, IncFII and IncX3 are critical platforms for taking blaKPC-2 and blaNDM. CONCLUSIONS: MDROs tend to carry more complex plasmid replicons compared with non-MDROs. The plasmid replicons that are predominantly prevalent and associated with ARGs differ in various species. The wide distribution of IncF-type plasmids and their close association with MDROs should deserve our attention. Further investigation into the critical role of plasmids in the carriage, evolution, and transmission of ARGs is needed.


Asunto(s)
Antibacterianos , Antiinfecciosos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Plásmidos/genética , beta-Lactamasas/genética , Bacterias Gramnegativas/genética , Carbapenémicos/farmacología , Fenotipo , Replicón , Pruebas de Sensibilidad Microbiana , Klebsiella pneumoniae/genética
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