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1.
Nat Commun ; 15(1): 5498, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38944647

ABSTRACT

IncX3 plasmids carrying the New Delhi metallo-ß-lactamase-encoding gene, blaNDM-5, are rapidly spreading globally in both humans and animals. Given that carbapenems are listed on the WHO AWaRe watch group and are prohibited for use in animals, the drivers for the successful dissemination of Carbapenem-Resistant Enterobacterales (CRE) carrying blaNDM-5-IncX3 plasmids still remain unknown. We observe that E. coli carrying blaNDM-5-IncX3 can persist in chicken intestines either under the administration of amoxicillin, one of the largest veterinary ß-lactams used in livestock, or without any antibiotic pressure. We therefore characterise the blaNDM-5-IncX3 plasmid and identify a transcription regulator, VirBR, that binds to the promoter of the regulator gene actX enhancing the transcription of Type IV secretion systems (T4SS); thereby, promoting conjugation of IncX3 plasmids, increasing pili adhesion capacity and enhancing the colonisation of blaNDM-5-IncX3 transconjugants in animal digestive tracts. Our mechanistic and in-vivo studies identify VirBR as a major factor in the successful spread of blaNDM-5-IncX3 across one-health AMR sectors. Furthermore, VirBR enhances the plasmid conjugation and T4SS expression by the presence of copper and zinc ions, thereby having profound ramifications on the use of universal animal feeds.


Subject(s)
Anti-Bacterial Agents , Chickens , Conjugation, Genetic , Escherichia coli , Plasmids , beta-Lactamases , Animals , Plasmids/genetics , beta-Lactamases/genetics , beta-Lactamases/metabolism , Chickens/microbiology , Humans , Escherichia coli/genetics , Escherichia coli/drug effects , Anti-Bacterial Agents/pharmacology , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Type IV Secretion Systems/genetics , Type IV Secretion Systems/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Amoxicillin/pharmacology , Promoter Regions, Genetic/genetics , Escherichia coli Infections/veterinary , Escherichia coli Infections/microbiology , Escherichia coli Infections/transmission , Gene Expression Regulation, Bacterial/drug effects , Intestines/microbiology
2.
Nat Commun ; 15(1): 3654, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38688912

ABSTRACT

The horizontal transfer of plasmids has been recognized as one of the key drivers for the worldwide spread of antimicrobial resistance (AMR) across bacterial pathogens. However, knowledge remain limited about the contribution made by environmental stress on the evolution of bacterial AMR by modulating horizontal acquisition of AMR plasmids and other mobile genetic elements. Here we combined experimental evolution, whole genome sequencing, reverse genetic engineering, and transcriptomics to examine if the evolution of chromosomal AMR to triclosan (TCS) disinfectant has correlated effects on modulating bacterial pathogen (Klebsiella pneumoniae) permissiveness to AMR plasmids and phage susceptibility. Herein, we show that TCS exposure increases the evolvability of K. pneumoniae to evolve TCS-resistant mutants (TRMs) by acquiring mutations and altered expression of several genes previously associated with TCS and antibiotic resistance. Notably, nsrR deletion increases conjugation permissiveness of K. pneumoniae to four AMR plasmids, and enhances susceptibility to various Klebsiella-specific phages through the downregulation of several bacterial defense systems and changes in membrane potential with altered reactive oxygen species response. Our findings suggest that unrestricted use of TCS disinfectant imposes a dual impact on bacterial antibiotic resistance by augmenting both chromosomally and horizontally acquired AMR mechanisms.


Subject(s)
Bacteriophages , Klebsiella pneumoniae , Plasmids , Triclosan , Triclosan/pharmacology , Plasmids/genetics , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/virology , Bacteriophages/genetics , Bacteriophages/physiology , Drug Resistance, Multiple, Bacterial/genetics , Mutation , Gene Transfer, Horizontal , Whole Genome Sequencing , Evolution, Molecular , Anti-Bacterial Agents/pharmacology
3.
Anal Chem ; 96(10): 4282-4289, 2024 Mar 12.
Article in English | MEDLINE | ID: mdl-38469640

ABSTRACT

Chirality is a widespread phenomenon in nature and in living organisms and plays an important role in living systems. The sensitive discrimination of chiral molecular enantiomers remains a challenge in the fields of chemistry and biology. Establishing a simple, fast, and efficient strategy to discriminate the spatial configuration of chiral molecular enantiomers is of great significance. Chiral perovskite nanocrystals (PNCs) have attracted much attention because of their excellent optical activity. However, it is a challenge to prepare perovskites with both chiral and fluorescence properties for chiral sensing. In this work, we synthesized two chiral fluorescent perovskite nanocrystal assembly (PNA) enantiomers by using l- or d-phenylalanine (Phe) as chiral ligands. PNA exhibited good fluorescence recognition for l- and d-proline (Pro). Homochiral interaction led to fluorescence enhancement, while heterochiral interaction led to fluorescence quenching, and there is a good linear relationship between the fluorescence changing rate and l- or d-Pro concentration. Mechanism studies show that homochiral interaction-induced fluorescence enhancement is attributed to the disassembly of chiral PNA, while no disassembly of chiral PNA was found in heterochiral interaction-induced fluorescence quenching, which is attributed to the substitution of Phe on the surface of chiral PNA by heterochiral Pro. This work suggests that chiral perovskite can be used for chiral fluorescence sensing; it will inspire the development of chiral nanomaterials and chiral optical sensors.

4.
Talanta ; 273: 125919, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38513470

ABSTRACT

2,4-dinitroaniline (2,4DNBA), a significant hazardous chemical, is extensively used in industry and agriculture. The chemical accumulates in the environment for a long time, causing irreversible damage to the ecosystem. Currently, it is quite challenging to identify it by common analysis and detection techniques. Herein, a luminescent organic cocrystal (TCNB-8HQ) was prepared using 1,2,4,5-tetracyanobenzene (TCNB) as the electron acceptor and 8-hydroxyquinoline (8HQ) as the electron donor. The prepared TCNB-8HQ was used as a fluorescent probe with a fast and specific response to 2,4DNBA. This detection method possessed a linear range of 0.5-200 µmol/L with a detection limit as low as 0.085 µmol/L to detect 2,4DNBA in real samples with satisfactory spiking recovery. As revealed by fluorescence spectrum and UV-vis absorption spectrum, the detection mechanism involved competitive absorption between cocrystal material and 2,4DNBA. Moreover, the feasibility of the system was explored by preparing portable indicator strips for 2,4DNBA from organic cocrystal (TCNB-8HQ). This study not only provided an environmentally friendly gram-level preparation strategy to synthesize the fluorescent material but also investigated their application in chemical detection.

6.
Article in English | MEDLINE | ID: mdl-38323900

ABSTRACT

Three microaerophilic bacterial strains, designated SG22T, SG63T and SG29T were isolated from paddy soils in PR China. Cells of these strains were Gram-staining-negative and long rod-shaped. SG22T, SG63T and SG29T showed the highest 16S rRNA gene sequence similarities with the members of the genus Anaeromyxobacter. The results of phylogenetic and phylogenomic analysis also indicated that these strains clustered with members of the genus Anaeromyxobacter. The main respiratory menaquinone of SG22T, SG63T and SG29T was MK-8 and the major fatty acids were iso-C15 : 0, iso-C17 : 0 and C16 : 0. SG22T, SG29T and SG63T not only possessed iron reduction ability but also harboured genes (nifHDK) encoding nitrogenase. The genomic DNA G+C contents of SG22T, SG63T and SG29T ranged from 73.3 to 73.5 %. The average nucleotide identity (ANI) and digital DNA-DNA hybridisation (dDDH) values between SG22T, SG63T and SG29T and the closely related species of the genus Anaeromyxobacter were lower than the cut-off values (dDDH 70 % and ANI 95-96 %) for prokaryotic species delineation. On the basis of these results, strains SG22T, SG63T and SG29T represent three novel species within the genus Anaeromyxobacter, for which the names Anaeromyxobacter terrae sp. nov., Anaeromyxobacter oryzisoli sp. nov. and Anaeromyxobacter soli sp. nov., are proposed. The type strains are SG22T (= GDMCC 1.3185T = JCM 35581T), SG63T (= GDMCC 1.2914T = JCM 35124T) and SG29T (= GDMCC 1.2911T = JCM 35123T).


Subject(s)
Myxococcales , Nitrogen-Fixing Bacteria , Ferric Compounds , Phylogeny , RNA, Ribosomal, 16S/genetics , Base Composition , Fatty Acids/chemistry , Sequence Analysis, DNA , DNA, Bacterial/genetics , Bacterial Typing Techniques , Nucleotides , Soil
7.
Luminescence ; 39(1): e4615, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37957886

ABSTRACT

By using the method of low-temperature crystallization, CsPbBr3 perovskite nanocrystals (PNCs) coated with trifluoroacetyl lysine (Tfa-Lys) and oleamine (Olam) were synthesized in aqueous solution. The structure of the CsPbBr3 PNCs was characterized by many methods, such as ultraviolet (UV)-visible absorption spectrophotometer, fluorescence spectrophotometer, transmission electron microscopy (TEM), and X-ray diffraction (XRD) pattern. The fluorescence emission of the CsPbBr3 PNCs is stable in water for about 1 day at room temperature. It was also found that the fluorescence of the PNCs could be obviously and selectively quenched after the addition of mercury ion (Hg2+ ), allowing a visual detection of Hg2+ by the naked eye under UV light illumination. The fluorescence quenching rate (I0 /I) has a good linear relationship with the addition of Hg2+ in the concentration range 0.075 to 1.5 mg/L, with a correlation coefficient (R2 ) of 0.997, and limit of detection of 0.046 mg/L. The fluorescence quenching mechanism of the PNCs was determined by the fluorescence lifetime and X-ray photoelectron spectroscopy (XPS) of the PNCs. Overall, the synthesis method for CsPbBr3 PNCs is simple and rapid, and the as-prepared PNCs are stable in water that could be conveniently used for selective detection of Hg2+ in the water environment.


Subject(s)
Calcium Compounds , Mercury , Nanoparticles , Titanium , Water/chemistry , Oxides/chemistry , Nanoparticles/chemistry
8.
Lancet Microbe ; 5(1): e13-e23, 2024 01.
Article in English | MEDLINE | ID: mdl-38006896

ABSTRACT

BACKGROUND: The global spread of plasmid-borne carbapenem resistance is an ongoing public health challenge; however, the nature of such horizontal gene transfer events among complex bacterial communities remains poorly understood. We examined the in-situ transfer of the globally dominant New Delhi metallo-ß-lactamase (NDM)-5-positive IncX3 plasmid (denoted pX3_NDM-5) in hospital wastewater to simulate a real-world, One Health antimicrobial resistance context. METHODS: For this transmission study, we tagged pX3_NDM-5 with the green fluorescent protein gene, gfp, using a CRISPR-based method and transferred the plasmid to a donor Escherichia coli strain. Bacteria were extracted from a hospital wastewater treatment plant (Fujian Provincial Maternity and Children's Hospital, Fuzhou, China) as the bacterial recipient community. We mixed this recipient community with the E coli donor strain carrying the gfp-tagged plasmid, both with and without sodium hypochlorite (NaClO) as an environmental stressor, and conducted several culture-based and culture-independent conjugation assays. The conjugation events were observed microscopically and quantified by fluorescence-activated cell sorting. We analysed the taxonomic composition of the sorted transconjugal pool by 16S rRNA gene amplicon sequencing and assessed the stability of the plasmid in the isolated transconjugants and its ability to transfer back to E coli. FINDINGS: We show that the plasmid pX3_NDM-5 has a broad host range and can transfer across various bacterial phyla, including between Gram-negative and Gram-positive bacteria. Although environmental stress with NaClO did not affect the overall plasmid transfer frequency, it reduced the breadth of the transconjugant pool. The taxonomic composition of the transconjugal pool was distinct from that of the recipient communities, and environmental stress modulated the permissiveness of some operational taxonomic units towards the acquisition of pX3_NDM-5. Notably, pX3_NDM-5 transconjugants included the Gram-positive pathogen Enterococcus faecalis, and the plasmid could subsequently be reconjugated back to E coli. These findings suggest that E faecalis could act as a natural shuttle vector for the wide dissemination of pX3_NDM-5 plasmids. INTERPRETATION: Our culture-independent conjugation model simulates natural environmental conditions and challenges the established theory that Gram-negative and Gram-positive bacteria rarely exchange clinically important plasmids. The data show that plasmids disseminate more widely across genera and phyla than previously thought. These findings have substantial implications when considering the spread of antimicrobial resistance across One Health sectors. FUNDING: The Laboratory of Lingnan Modern Agriculture Project, the National Natural Science Foundation of China, the Natural Science Foundation of Fujian Province of China, and the Outstanding Young Research Talents Program of Fujian Agriculture and Forestry University.


Subject(s)
Anti-Infective Agents , Escherichia coli , Female , Pregnancy , Child , Humans , Escherichia coli/genetics , Wastewater , RNA, Ribosomal, 16S/genetics , Plasmids/genetics , Bacteria/genetics , Hospitals
9.
Int J Clin Pract ; 2023: 6638089, 2023.
Article in English | MEDLINE | ID: mdl-37588100

ABSTRACT

In this study, we conducted a meta-analysis to assess the efficacy and safety of teprotumumab in treating thyroid eye disease. We searched the Cochrane Library, PubMed, and Embase databases from inception to May 25, 2022, and included all randomized controlled trials. Odds ratios (ORs) were calculated using fixed- or random-effect models. A total of three studies involving 341 patients were identified. Overall, the analysis revealed that teprotumumab demonstrated superior integrated proptosis response compared to placebo in both the intention-to-treat (ITT) population (OR = 17.81, 95% CI = [10.32, 30.76], I2 = 50%) and per-protocol population (OR = 24.53, 95% CI = [12.96, 46.45], I2 = 14%). Furthermore, patients receiving teprotumumab showed significant improvement in overall response (OR = 8.35, 95% CI = [4.74, 14.71], I2 = 79%), diplopia response (OR = 5.53, 95% CI = [3.24, 9.44], I2 = 0%), and achieving a clinical activity score (CAS) of 0 or 1 (OR = 6.26, 95% CI = [3.87, 10.12], I2 = 0%). Moreover, patients treated with teprotumumab experienced greater improvements in proptosis (MD = -2.49, 95% CI = [-2.54, -2.45], I2 = 98%) and Graves' ophthalmopathy-specific quality of life (GO-QOL, MD = 11.48, 95% CI = [11.03, 11.93], I2 = 95%). However, it is important to note that patients receiving teprotumumab had a higher risk of adverse events, including serious adverse events, gastrointestinal adverse reactions, and muscle spasms. In summary, teprotumumab demonstrated greater improvement in proptosis response, proptosis, diplopia response, overall response, GO-QOL, and CAS. Nonetheless, it should be considered that its use is associated with a higher risk of adverse events.


Subject(s)
Exophthalmos , Graves Ophthalmopathy , Humans , Graves Ophthalmopathy/drug therapy , Quality of Life , Diplopia , Randomized Controlled Trials as Topic
10.
ACS Appl Mater Interfaces ; 15(35): 41977-41991, 2023 Sep 06.
Article in English | MEDLINE | ID: mdl-37606315

ABSTRACT

Lanthanide metal-organic frameworks (Ln-MOFs) with exceptional optical performance and structural diversity offer a unique platform for the development of luminescent materials. However, Ln-MOFs often suffer from luminescence quenching by high-vibrating oscillators, especially in aqueous solution. Thus, multiple strategies have been adopted to improve the luminescence of Ln3+. Anomalous research about water-induced lanthanide luminescence enhancement of Ln-MOFs is in the primary stage. Here, two Eu-based metal-organic framework (Eu-MOF) isomers named QXBA-Eu-1 and QXBA-Eu-2 were constructed by using the same ligand under different solvent thermal conditions, which exhibited distinctive water- and methanol-boosting emission behaviors. As for QXBA-Eu-1, water and methanol molecules replaced the free N,N-dimethylacetamide (DMA) molecules in the framework, repressed the rotation or libration suppression of the QXBA linker, and formed hydrogen bonds with the coordinated water molecules, which suppressed the O-H high-energy vibrations, reduced nonradiative transitions, stabilized the T1 state, and facilitated the intersystem crossing (ISC) process. For QXBA-Eu-2, water molecules tended to replace the coordinated DMA ligands, which altered the S1 and T1 energy levels of the ligand and facilitated the ligand-to-metal energy transfer (LMET) process and strengthened the luminescence of Eu3+. Importantly, free solvent molecules and the hydroxylation of Eu3+ centers also restrained the rotation or libration of the QXBA linker, by which the nonradiative transition was further inhibited and the lanthanide luminescence enhanced. Thus, this work not only opened an unprecedented path to enhance lanthanide luminescence in aqueous solution but also expanded its application scope.

11.
ISME J ; 17(6): 916-930, 2023 06.
Article in English | MEDLINE | ID: mdl-37031344

ABSTRACT

While decomposition of organic matter by bacteria plays a major role in nutrient cycling in terrestrial ecosystems, the significance of viruses remains poorly understood. Here we combined metagenomics and metatranscriptomics with temporal sampling to study the significance of mesophilic and thermophilic bacteria and their viruses on nutrient cycling during industrial-scale hyperthermophilic composting (HTC). Our results show that virus-bacteria density dynamics and activity are tightly coupled, where viruses specific to mesophilic and thermophilic bacteria track their host densities, triggering microbial community succession via top-down control during HTC. Moreover, viruses specific to mesophilic bacteria encoded and expressed several auxiliary metabolic genes (AMGs) linked to carbon cycling, impacting nutrient turnover alongside bacteria. Nutrient turnover correlated positively with virus-host ratio, indicative of a positive relationship between ecosystem functioning, viral abundances, and viral activity. These effects were predominantly driven by DNA viruses as most detected RNA viruses were associated with eukaryotes and not associated with nutrient cycling during the thermophilic phase of composting. Our findings suggest that DNA viruses could drive nutrient cycling during HTC by recycling bacterial biomass through cell lysis and by expressing key AMGs. Viruses could hence potentially be used as indicators of microbial ecosystem functioning to optimize productivity of biotechnological and agricultural systems.


Subject(s)
Composting , Microbiota , Viruses , Viruses/genetics , Archaea , Bacteria/genetics , Microbiota/genetics , Nutrients
12.
Article in Chinese | MEDLINE | ID: mdl-37100753

ABSTRACT

Objective: To evaluate the efficacy of neoadjuvant chemotherapy (NACT) in the treatment of locally advanced olfactory neuroblastoma (ONB), and to explore the factors related to the efficacy of NACT. Methods: A total of 25 patients with ONB who underwent NACT in Beijing TongRen Hospital from April 2017 to July 2022 were retrospectively analyzed. There were 16 males and 9 females, with an average age of 44.9 years (ranged 26-72 years). There were 22 cases of Kadish stage C and 3 cases of stage D. After multiple disciplinary team(MDT) discussion, all patients were treated sequentially with NACT-surgery-radiotherapy. Among them, 17 cases were treated with taxol, cis-platinum and etoposide (TEP), 4 cases with taxol, nedaplatin and ifosfamide (TPI), 3 cases with TP, while 1 case with EP. SPSS 25.0 software was used for statistical analysis, and survival analyses were calculated based on the Kaplan-Meier method. Results: The overall response rate of NACT was 32% (8/25). Subsequently, 21 patients underwent extended endoscopic surgery and 4 patients underwent combined cranial-nasal approach. Three patients with stage D disease underwent cervical lymph node dissection. All patients received postoperative radiotherapy. The mean follow-up time was 44.2 months (ranged 6-67 months). The 5-year overall survival rate was 100.0%, and the 5-year disease-free survival rates was 94.4%. Before NACT, Ki-67 index was 60% (50%, 90%), while Ki-67 index was 20% (3%, 30%) after chemotherapy [M (Q1, Q3)]. The change of Ki-67 before and after NACT was statistically significant (Z=-24.24, P<0.05). The effects of age, gender, history of surgery, Hyams grade, Ki-67 index and chemotherapy regimen to NACT were analyzed. Ki-67 index≥25% and high Hyams grade were related to the efficacy of NACT (all P<0.05). Conclusions: NACT could reduce Ki-67 index in ONBs. High Ki-67 index and Hyams grade are clinical indicators sensitive to the efficacy of NACT. NACT-surgery-radiotherapy is effective for patients with locally advanced ONB.


Subject(s)
Esthesioneuroblastoma, Olfactory , Nose Neoplasms , Male , Female , Humans , Adult , Middle Aged , Aged , Neoadjuvant Therapy/adverse effects , Neoadjuvant Therapy/methods , Retrospective Studies , Esthesioneuroblastoma, Olfactory/therapy , Esthesioneuroblastoma, Olfactory/etiology , Ki-67 Antigen , Paclitaxel , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Nasal Cavity , Nose Neoplasms/therapy , Neoplasm Staging
13.
ACS Appl Mater Interfaces ; 15(18): 22590-22601, 2023 May 10.
Article in English | MEDLINE | ID: mdl-37098047

ABSTRACT

The concentration of vanillymandelic acid (VMA) in urine is closely related with pheochromocytoma diagnosis. Thus, it is essential to develop more accurate and convenient fluorescence sensing strategies toward VMA. Until now, the design of double ratiometric detection methods for VMA was still in the unexplored stage. In this work, novel Ln3+-based metal-organic frameworks (QBA-Eu and QBA-Gd0.875Eu0.125) possessing dual emission peaks was fabricated successfully, which served as isomers of YNU-1 and exhibited more excellent water stability in fluorescence and structure than the ones of YNU-1. The formation of the complex between QBA ligands and VMA molecules via hydrogen bonds within QBA-Eu frameworks produced a new emission band centered at 450 nm and resulted in the decline of monomer emission intensity for QBA at 390 nm. Owing to the reduced energy gap [ΔE (S1 - T1)], the antenna effect was hampered and luminescence of Eu3+ ions also decreased. The developed double ratiometric (I615nm/I475nm, I390nm/I475nm) fluorescence sensors based on QBA-Eu and QBA-Gd0.875Eu0.125 possessed the advantages of fast response (4 min), low detection limits (0.58 and 0.51; 0.22 and 0.31 µM), and wide linear ranges (2-100 and 2-80 µM), which met the requirements of pheochromocytoma diagnosis. We also applied them to determine VMA in an artificial urine sample and diluted human urine sample and obtained satisfactory results. They will become prospective fluorescence sensing platforms for VMA.


Subject(s)
Adrenal Gland Neoplasms , Lanthanoid Series Elements , Metal-Organic Frameworks , Pheochromocytoma , Humans , Lanthanoid Series Elements/chemistry , Metal-Organic Frameworks/chemistry , Fluorescent Dyes/chemistry , Prospective Studies , Spectrometry, Fluorescence/methods
14.
Inorg Chem ; 61(43): 17185-17195, 2022 Oct 31.
Article in English | MEDLINE | ID: mdl-36263654

ABSTRACT

The establishment of a reliable and sensitive method for the detection of flavonoids, such as kaempferol (Kae) and quercetin (Que), is important and challenging in food chemistry and pharmacology because numerous structural analogues may interfere with the detection. Until now, designing an efficient switch-on fluorescence sensing strategy for Kae and Que was still in the unachievable stage. In this work, a switch-on near-infrared (NIR) luminescence sensing assay for Kae and Que was fabricated based on a metal-organic framework (MOF) called IQBA-Yb for the first time. The fluorescence enhancing mechanism was that analytes served as additional "antenna" of Yb3+, leading to the efficient switch-on NIR emission under excitation at 467 nm. Meanwhile, the combination results of experiment and theoretical calculation revealed that there existed hydrogen bonds between Kae, Que, and the MOF skeleton, further promoting the energy transfer between the analyte and Yb3+ and facilitating fluorescence enhancement response. The developed probe possessed excellent sensing capability for Kae and Que, accompanied by a wide linear range (0.04-70, 0.06-90 µM), low detection limit (0.01, 0.06 µM), and short response time (20 min, 6 min), which was used to determine the Kae and Que contents in Green Lake and eatable Que samples with satisfactory results.


Subject(s)
Metal-Organic Frameworks , Quercetin , Quercetin/chemistry , Kaempferols/chemistry , Luminescence , Flavonoids/chemistry
15.
Ying Yong Sheng Tai Xue Bao ; 33(4): 1083-1090, 2022 Apr.
Article in Chinese | MEDLINE | ID: mdl-35543063

ABSTRACT

With the Quanfuzhuang River basin located at Hani Rice Terrace core region as study area, we analyzed the isotopic composition and the effects of 12 surface water sampling sites for the forest landscape type and terrace landscape type from May 2015 to April 2016. The results showed that: 1) For the variation of isotope composition, both the average value and the variation range of δ18O in surface water under forest patches were smaller than that under terrace patches. 2) The overall elevation effect of the hydrogen and oxygen stable isotopes in surface water was obvious, except that in August and March, which could be expressed as the linear regression equation δ18O=-0.012H+13.84 (r=-0.83, n=12). 3) The altitude gradient of δ18O in surface water was -1.2‰·(100 m)-1, which was not the true altitude gradient affected by precipitation but by landscape gradient of δ18O in surface water between forest patches and terrace patches. 4) Under the "Forest-Terrace" landscape pattern, the δ18O differences in surface water between forest patches and terrace patches enhanced the elevation effect. Therefore, when landscape heterogeneity was strong, isotopic effect was strengthened, even with opposite isotope effect.


Subject(s)
Oryza , Water , Hydrogen , Oxygen Isotopes/analysis , Rivers
16.
Int J Antimicrob Agents ; 59(5): 106568, 2022 May.
Article in English | MEDLINE | ID: mdl-35288258

ABSTRACT

OBJECTIVE: To describe the undetected circulation of an epidemic BKC-1-producing Klebsiella pneumoniae ST442 clone, occasioning the first reported outbreak of the infrequent carbapenemase BKC-1. METHODS: Six hundred and forty-seven K. pneumoniae isolates (2008-2017) with reduced susceptibility to carbapenems were screened for blaBKC-1. BKC-1-positive isolates were typed using pulsed-field gel electrophoresis and multi-locus sequence typing. Susceptibility profiles were determined by broth microdilution, and additional antimicrobial resistance genes (ARGs) were investigated by polymerase chain reaction. Some isolates were submitted to full genomic characterization by whole-genome sequencing (Illumina MiSeq and MinIon), and in-vivo virulence studies using the Galleria mellonella model. RESULTS: Sixteen (2.5%) K. pneumoniae, from 15 patients, carrying blaBKC-1 were found between 2010 and 2012. Among these patients, the all-cause mortality rate was 54.5%. A major clone - A1-ST442 (13/16) - was isolated during the study period. The BKC-1-producing isolates had a multi-drug-resistant phenotype, remaining susceptible to gentamicin (87.5%) and ceftazidime-avibactam (100%) alone. The presence of two carbapenemases - blaBKC-1 and blaKPC-2 - was detected in six isolates, increasing the ß-lactam minimum inhibitory concentration significantly. Additionally, other ARGs were identified on A1-ST442 and B1-ST11 clones. The B1-ST11 clone was more virulent than the A1-ST442 clone. CONCLUSION: An undetected outbreak caused predominantly by a BKC-1-positive A1-ST442 clone between 2010 and 2012 was identified 10 years later in a Brazilian hospital. The misidentification of BKC-1 may have worsened the spread of resistant clones; this reinforces the need for correct and rapid identification of antimicrobial resistance mechanisms in hospitals.


Subject(s)
Klebsiella Infections , Klebsiella pneumoniae , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacterial Proteins/genetics , Carbapenems/pharmacology , Disease Outbreaks , Humans , Klebsiella Infections/drug therapy , Klebsiella Infections/epidemiology , Klebsiella pneumoniae/genetics , Microbial Sensitivity Tests , Multilocus Sequence Typing , beta-Lactamases/genetics
17.
Otolaryngol Head Neck Surg ; 167(2): 382-390, 2022 08.
Article in English | MEDLINE | ID: mdl-35015582

ABSTRACT

OBJECTIVE: This study aimed to assess the effectiveness of 3 endoscopic endonasal approaches for the management of cerebrospinal fluid (CSF) leaks and meningoencephaloceles in the lateral recess of the sphenoid sinus (LRSS). STUDY DESIGN: Retrospective study. SETTING: University hospital. METHODS: This study retrospectively reviewed 49 patients with CSF leaks and meningoencephaloceles in the LRSS. Three endoscopic surgical repair approaches were indicated based on 5 different Rhoton's types of the LRSS. The postoperative symptoms, complications, and follow-up outcomes were investigated and evaluated. RESULTS: The success rate of endoscopic surgical repair was 100% at a median follow-up of 75.06 (12-203.4) months. Endoscopic approaches to the LRSS included the prelacrimal recess (PLR) (18.37%), transsphenoidal (18.37%), and transpterygoid approaches (64.26%). All patients in the PLR approach (PLRA) group and most of the patients in the transpterygoid approach group had a full lateral type LRSS. Hypoesthesia and dry eyes were reported in 5 patients (55.56%) and 1 (11.12%) patient, respectively, from the PLRA group and in 6 (19.35%) and 5 (16.12%) patients, respectively, from the transpterygoid approach group. CONCLUSIONS: Endoscopic closure is a safe and effective method for the treatment of CSF leaks and meningoencephaloceles in the LRSS. The transpterygoid approach and PLRA offer adequate exposure of the LRSS with extensive lateral pneumatization or a full LRSS. The endoscopic route of the PLRA is more direct than that of the transpterygoid approach. Careful preoperative imaging evaluation is crucial while selecting the optimal surgical approach for the repair of a skull base defect.


Subject(s)
Cerebrospinal Fluid Leak , Sphenoid Sinus , Cerebrospinal Fluid Leak/surgery , Encephalocele/surgery , Endoscopy/methods , Humans , Retrospective Studies , Sphenoid Sinus/surgery
18.
Talanta ; 238(Pt 2): 123030, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-34801893

ABSTRACT

The development of analytical method for selective and sensitive detection of gossypol (Gsp), an extraction from the cotton plants, is important but still challenging in food safety and medical field. Herein, we reported a turn-on near infrared (NIR) fluorescence detection strategy for Gsp based on a metal-organic framework (MOF), QBA-Yb, which was prepared from 4,4'-(quinolone-5, 8-diyl) benzoate with Yb(NO3)3·5H2O by solvothermal synthesis. The Gsp acted as another "antenna" to sensitize the luminescence of Yb3+, leading to the turn-on NIR emission upon 467 nm excitation. As Gsp concentration increased, the NIR emission at 973 nm enhanced gradually, thus enabling highly sensitive Gsp detection in a turn-on way. The experiment and theoretical calculation results revealed the presence of strong hydrogen bonds between Gsp molecules and the MOF skeleton. The developed QBA-Yb probe showed excellent characteristics for detection of Gsp molecules, accompanied by wide linear range (5-160 µg/mL), low detection limit (0.65 µg/mL) and short response time (within 10 min). We have further demonstrated that the QBA-Yb probe was successfully applied for the determination of Gsp in real samples of cottonseeds.


Subject(s)
Gossypol , Metal-Organic Frameworks , Fluorescence , Luminescence
19.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-943082

ABSTRACT

ObjectiveTo observe the effects of the water extracts of Trichosanthis Radix-Polygonati Rhizoma at different ratios on glucose and lipid metabolism in KKAy mice with spontaneous type 2 diabetes and explore the mechanism of the extract in alleviating insulin resistance based on phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/forkhead box O1 (FoxO1) signaling pathway. MethodThe 8-week-old C57BL/6J male mice were taken as the normal control group, and KKAy male mice of the same age were randomly assigned into a model group, a metformin group, Trichosanthis Radix-Polygonati Rhizoma groups at the ratios of 1∶1 (Trichosanthis Radix 30 g, Polygonati Rhizoma 30 g), 1∶3 (Trichosanthis Radix 15 g, Polygonati Rhizoma 45 g), and 1∶5 (Trichosanthis Radix 10 g, Polygonati Rhizoma 50 g) according to blood glucose level and body weight, with 6 mice in each group. The administration lasted for 8 weeks, and the body weight (BW) and fasting blood glucose (FBG) of mice were recorded at the same time points of the 2nd, 4th, 6th, and 8th weeks, respectively. Oral glucose tolerance test (OGTT) was performed at the 7th week. After drug administration, the serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and fasting insulin (FINS) were measured, and homeostasis model assessment-insulin resistance (HOMA-IR) index was calculated. The liver tissue samples were stained with hematylin-eosin (HE) and periodic acid-Schiff (PAS) for observation of the fat distribution and glycogen content. The protein levels of PI3K, Akt, p-Akt, FoxO1, and p-FoxO1 in the liver were determined by Western blot. ResultCompared with the normal group, the model group showed increased food intake, FBG, glucose tolerance, FINS, HOMA-IR, TC, TG, and LDL-C (P<0.01), and down-regulated protein levels of PI3K, Akt, phosphorylaison (p)-Akt, FoxO1, and p-FoxO1 in the liver (P<0.01). Compared with the model group, Trichosanthis Radix-Polygonati Rhizoma lowered FBG and HOMA-IR (P<0.05, P<0.01). In particular, the combination at the ratio of 1∶3 showed the best performance (P<0.01) comparable to metformin. Furthermore, Trichosanthis Radix-Polygonati Rhizoma at different ratios lowered blood glucose at different time points of OGTT (P<0.05) and TC and LDL-C (P<0.01). Additionally, the combination at the ratio of 1∶3 reduced TG (P<0.01). The liver of mice in the drug administration groups showed regular morphology, with few lipid droplets and rich glycogen. Western blot showed that Trichosanthis Radix-Polygonati Rhizoma up-regulated the protein levels of PI3K and p-Akt, down-regulated the protein level of FoxO1, and up-regulated the protein level of p-FoxO1 (P<0.05). ConclusionTrichosanthis Radix-Polygonati Rhizoma, especially at the ratio of 1∶3, lowered the FBG, TC, LDL-C, and HOMA-IR index, promoted liver glycogen synthesis, and reduced steatosis in KKAy mice, which may be related to the regulation of PI3K/Akt/FoxO1 signaling pathway in the liver.

20.
Inorg Chem ; 60(24): 18870-18878, 2021 Dec 20.
Article in English | MEDLINE | ID: mdl-34855375

ABSTRACT

Photochromic materials are constructed with molecules accompanied by structural change after triggering by light, which are of great importance and necessity for various applications. However, because of space-confinement effects, molecule stacking of these photoresponsive chromophores within coordination polymers (CPs) always results in an efficiency decrement and a response delay, and this phenomenon will lead to a poor photochromic property. Herein, a CP (named CIT-E) with a 3-fold-interpenetrating network structure, which was prepared with (Z)-1,2-diphenyl-1,2-bis[4-(pyridin-3-ylmethoxy)phenyl]ethene (1Z) and a CuI cluster, showed fast reversible photochromic behavior. Under UV-light illumination, the color of CIT-Z changed from pale yellow to reddish brown. With the illumination of green light, the polymer could return to its initial color within 10 s. To reveal the mechanism of reversible photochromic behavior of CIT-Z, single-crystal structures of each color state were fully studied, and other scientific study methods were also used, such as time-dependent density functional theory calculation and control experiments. It was found that, with light illumination, this behavior of CIT-Z was the result of a ligand-to-metal charge-transfer process, and this process was triggered by subtle molecular conformation variation of tetraphenylethylene. It should be noted that CIT-Z has high thermal and chemical stability, which are excellent advantages as smart photoresponsive materials. As a proof of concept, a uniform thin film with such a fascinating photochromic property allows applications in invisible anticounterfeiting and dynamic optical data storage. Overall, the present study opens up a new avenue toward reversible photochromic materials.

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