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1.
Nucleic Acids Res ; 52(17): 10619-10629, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-38989619

RESUMO

The type III-A (Csm) CRISPR-Cas systems are multi-subunit and multipronged prokaryotic enzymes in guarding the hosts against viral invaders. Beyond cleaving activator RNA transcripts, Csm confers two additional activities: shredding single-stranded DNA and synthesizing cyclic oligoadenylates (cOAs) by the Cas10 subunit. Known Cas10 enzymes exhibit a fascinating diversity in cOA production. Three major forms-cA3, cA4 and cA6have been identified, each with the potential to trigger unique downstream effects. Whereas the mechanism for cOA-dependent activation is well characterized, the molecular basis for synthesizing different cOA isoforms remains unclear. Here, we present structural characterization of a cA6-producing Csm complex during its activation by an activator RNA. Analysis of the captured intermediates of cA6 synthesis suggests a 3'-to-5' nucleotidyl transferring process. Three primary adenine binding sites can be identified along the chain elongation path, including a unique tyrosine-threonine dyad found only in the cA6-producing Cas10. Consistently, disrupting the tyrosine-threonine dyad specifically impaired cA6 production while promoting cA4 production. These findings suggest that Cas10 utilizes a unique enzymatic mechanism for forming the phosphodiester bond and has evolved distinct strategies to regulate the cOA chain length.


Assuntos
Proteínas Associadas a CRISPR , Sistemas CRISPR-Cas , Proteínas Associadas a CRISPR/metabolismo , Proteínas Associadas a CRISPR/genética , Nucleotídeos de Adenina/metabolismo , Nucleotídeos de Adenina/biossíntese , Sítios de Ligação , Modelos Moleculares , Oligorribonucleotídeos/metabolismo , Oligorribonucleotídeos/genética , Oligorribonucleotídeos/biossíntese , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/química
2.
Proc Natl Acad Sci U S A ; 120(2): e2205199120, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36598941

RESUMO

Assembly of protein complexes is facilitated by assembly chaperones. Alpha and gamma adaptin-binding protein (AAGAB) is a chaperone governing the assembly of the heterotetrameric adaptor complexes 1 and 2 (AP1 and AP2) involved in clathrin-mediated membrane trafficking. Here, we found that before AP1/2 binding, AAGAB exists as a homodimer. AAGAB dimerization is mediated by its C-terminal domain (CTD), which is critical for AAGAB stability and is missing in mutant proteins found in patients with the skin disease punctate palmoplantar keratoderma type 1 (PPKP1). We solved the crystal structure of the dimerization-mediating CTD, revealing an antiparallel dimer of bent helices. Interestingly, AAGAB uses the same CTD to recognize and stabilize the γ subunit in the AP1 complex and the α subunit in the AP2 complex, forming binary complexes containing only one copy of AAGAB. These findings demonstrate a dual role of CTD in stabilizing resting AAGAB and binding to substrates, providing a molecular explanation for disease-causing AAGAB mutations. The oligomerization state transition mechanism may also underlie the functions of other assembly chaperones.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular , Ceratodermia Palmar e Plantar , Humanos , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Proteínas de Transporte/genética , Ceratodermia Palmar e Plantar/genética , Ceratodermia Palmar e Plantar/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Clatrina/metabolismo , Complexo 2 de Proteínas Adaptadoras/genética , Complexo 2 de Proteínas Adaptadoras/metabolismo
3.
Plant J ; 117(5): 1487-1502, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38048475

RESUMO

Powdery mildew (PM) is one of the most serious fungal diseases affecting cucumbers (Cucumis sativus L.). The mechanism of PM resistance in cucumber is intricate and remains fragmentary as it is controlled by several genes. In this study, we detected the major-effect Quantitative Trait Locus (QTL), PM5.2, involved in PM resistance by QTL mapping. Through fine mapping, the dominant PM resistance gene, CsPM5.2, was cloned and its function was confirmed by transgenic complementation and natural variation identification. In cultivar 9930, a dysfunctional CsPM5.2 mutant resulted from a single nucleotide polymorphism in the coding region and endowed susceptibility to PM. CsPM5.2 encodes a phosphate transporter-like protein PHO1; H3. The expression of CsPM5.2 is ubiquitous and induced by the PM pathogen. In cucumber, both CsPM5.2 and Cspm5.1 (Csmlo1) are required for PM resistance. Transcriptome analysis suggested that the salicylic acid (SA) pathway may play an important role in CsPM5.2-mediated PM resistance. Our findings help parse the mechanisms of PM resistance and provide strategies for breeding PM-resistant cucumber cultivars.


Assuntos
Ascomicetos , Cucumis sativus , Cucumis sativus/genética , Fosfatos , Ascomicetos/genética , Melhoramento Vegetal , Mapeamento Cromossômico , Resistência à Doença/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia
4.
Plant J ; 119(2): 1039-1058, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38804740

RESUMO

Plant stems constitute the most abundant renewable resource on earth. The function of lysine (K)-2-hydroxyisobutyrylation (Khib), a novel post-translational modification (PTM), has not yet been elucidated in plant stem development. Here, by assessing typical pepper genotypes with straight stem (SS) and prostrate stem (PS), we report the first large-scale proteomics analysis for protein Khib to date. Khib-modifications influenced central metabolic processes involved in stem development, such as glycolysis/gluconeogenesis and protein translation. The high Khib level regulated gene expression and protein accumulation associated with cell wall formation in the pepper stem. Specially, we found that CaMYB61 knockdown lines that exhibited prostrate stem phenotypes had high Khib levels. Most histone deacetylases (HDACs, e.g., switch-independent 3 associated polypeptide function related 1, AFR1) potentially function as the "erasing enzymes" involved in reversing Khib level. CaMYB61 positively regulated CaAFR1 expression to erase Khib and promote cellulose and hemicellulose accumulation in the stem. Therefore, we propose a bidirectional regulation hypothesis of "Khib modifications" and "Khib erasing" in stem development, and reveal a novel epigenetic regulatory network in which the CaMYB61-CaAFR1 molecular module participating in the regulation of Khib levels and biosynthesis of cellulose and hemicellulose for the first time.


Assuntos
Capsicum , Regulação da Expressão Gênica de Plantas , Lisina , Proteínas de Plantas , Caules de Planta , Proteômica , Caules de Planta/genética , Caules de Planta/metabolismo , Caules de Planta/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Capsicum/genética , Capsicum/crescimento & desenvolvimento , Capsicum/metabolismo , Lisina/metabolismo , Processamento de Proteína Pós-Traducional , Parede Celular/metabolismo , Parede Celular/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética
5.
J Biol Chem ; 299(3): 102986, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36754281

RESUMO

Dengue virus (DENV) is one of the most prevalent mosquito-transmitted human viruses that causes significant morbidity and mortality worldwide. To persist in the cell and consequently cause disease, DENV is evolved with mechanisms to suppress the induction of type I interferons by antagonizing cGAS-STING signaling. Using recombinant proteins and in vitro cleavage assays, we have shown that the DENV protease NS2B3 is capable of cleaving cGAS in the N-terminal region without disrupting the C-terminal catalytic center. This generates two major cleavage products: cleavage product N-terminal (CP-N) and cleavage product C-terminal (CP-C). We observed reduction in DNA-binding affinity of CP-C as compared to full-length cGAS. Reduction in DNA-binding affinity is also correlated with the decrease in enzymatic activity of CP-C. CP-N, on the other hand, has almost comparable DNA-binding ability as that of the full-length cGAS. In fact, CP-N competitively inhibits cyclic GMP-AMP production by both full-length cGAS and CP-C. We hypothesize that high DNA-binding affinity of CP-N enables it to sequester the DNA from CP-C and noncleaved full-length cGAS and thus reduces the rate of enzyme activation and cyclic GMP-AMP synthesis. Furthermore, we found that NS2B3 physically interacts with full-length cGAS and CP-C, laying the basis for their shuttling to and eventual degradation in the autophagosome. Overall, our study highlights a multifaceted and effective strategy by which an RNA virus antagonizes cGAS-STING signaling which may be useful for the design of antivirals targeting viral proteases.


Assuntos
Vírus da Dengue , Nucleotidiltransferases , Peptídeo Hidrolases , Humanos , Vírus da Dengue/enzimologia , Imunidade Inata , Nucleotidiltransferases/metabolismo , Peptídeo Hidrolases/metabolismo
6.
Mol Microbiol ; 119(6): 752-767, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37170643

RESUMO

Borrelia spirochetes are unique among diderm bacteria in their lack of lipopolysaccharide (LPS) in the outer membrane (OM) and their abundance of surface-exposed lipoproteins with major roles in transmission, virulence, and pathogenesis. Despite their importance, little is known about how surface lipoproteins are translocated through the periplasm and the OM. Here, we characterized Borrelia burgdorferi BB0838, a distant homolog of the OM LPS assembly protein LptD. Using a CRISPR interference approach, we showed that BB0838 is required for cell growth and envelope stability. Upon BB0838 knockdown, surface lipoprotein OspA was retained in the inner leaflet of the OM, as determined by its inaccessibility to in situ proteolysis but its presence in OM vesicles. The topology of the OM porin/adhesin P66 remained unaffected. Quantitative mass spectrometry of the B. burgdorferi membrane-associated proteome confirmed the selective periplasmic retention of surface lipoproteins under BB0838 knockdown conditions. Additional analysis identified a single in situ protease-accessible BB0838 peptide that mapped to a predicted ß-barrel surface loop. Alphafold Multimer modeled a B. burgdorferi LptB2 FGCAD complex spanning the periplasm. Together, this suggests that BB0838/LptDBb facilitates the essential terminal step in spirochetal surface lipoprotein secretion, using an orthologous OM component of a pathway that secretes LPS in proteobacteria.


Assuntos
Borrelia burgdorferi , Borrelia burgdorferi/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Lipopolissacarídeos/metabolismo , Bactérias/metabolismo , Lipoproteínas/metabolismo
7.
Small ; 20(28): e2310786, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38317521

RESUMO

High-entropy materials have attracted much attention in the electrocatalysis field due to their unique structure, high chemical activity, and compositional tunability. However, the harsh and complex synthetic methods limit the application of such materials. Herein, a universal non-equilibrium liquid-phase synthesis strategy is reported to prepare high-entropy amorphous oxide nanoparticles (HEAO-NPs), and the composition of HEAO-NPs can be precisely controlled from tri- to ten-component. The non-equilibrium synthesis environment provided by an excessively strong reducing agent overcomes the difference in the reduction potentials of various metal ions, resulting in the formation of HEAO-NPs with a nearly equimolar ratio. The oxygen evolution reaction (OER) performance of HEAO-NPs is further improved by adjusting the composition and optimizing the electronic structure. The Fe16Co32Ni32Mn10Cu10BOy exhibits a smaller overpotential (only 259 mV at 10 mA cm-2) and higher stability in OER compared with commercial RuO2. The amorphous high-entropy structure with an optimized concentration of iron makes the binding energy of CoNi shift to a higher direction, promotes the generation of high-valence active intermediates, and accelerates the OER kinetic process. The HEAO-NPs have promising application potential in the field of catalysis, biology, and energy storage, and this work provides a general synthesis method for composition-controllable high-entropy materials.

8.
Small ; 20(2): e2306464, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37658488

RESUMO

Transition metals are excellent active sites to activate peroxymonosulfate (PMS) for water treatment, but the favorable electronic structures governing  reaction mechanism still remain elusive. Herein, the authors construct typical d-orbital configurations on iron octahedral (FeOh ) and tetrahedral (FeTd ) sites in spinel ZnFe2 O4 and FeAl2 O4 , respectively. ZnFe2 O4 (136.58 min-1 F-1 cm2 ) presented higher specific activity than FeAl2 O4 (97.47 min-1 F-1 cm2 ) for tetracycline removal by PMS activation. Considering orbital features of charge amount, spin state, and orbital arrangement by magnetic spectroscopic analysis, ZnFe2 O4 has a larger bond order to decompose PMS. Using this descriptor, high-spin FeOh is assumed to activate PMS mainly to produce nonradical reactive oxygen species (ROS) while high-spin FeTd prefers to induce radical species. This hypothesis is confirmed by the selective predominant ROS of 1 O2 on ZnFe2 O4 and O2 •- on FeAl2 O4 via quenching experiments. Electrochemical determinations reveal that FeOh has superior capability than FeTd for feasible valence transformation of iron cations and fast interfacial electron transfer. DFT calculations further suggest octahedral d-orbital configuration of ZnFe2 O4 is beneficial to enhancing Fe-O covalence for electron exchange. This work attempts to understand the d-orbital configuration-dependent PMS activation to design efficient catalysts.

9.
Brief Bioinform ; 23(1)2022 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-34661630

RESUMO

With the development of biotechnology, a large number of phosphorylation sites have been experimentally confirmed and collected, but only a few of them have kinase annotations. Since experimental methods to detect kinases at specific phosphorylation sites are expensive and accidental, some computational methods have been proposed to predict the kinase of these sites, but most methods only consider single sequence information or single functional network information. In this study, a new method Predicting Kinase of Specific Phosphorylation Sites (PKSPS) is developed to predict kinases of specific phosphorylation sites in human proteins by combining PKSPS-Net with PKSPS-Seq, which considers protein-protein interaction (PPI) network information and sequence information. For PKSPS-Net, kinase-kinase and substrate-substrate similarity are quantified based on the topological similarity of proteins in the PPI network, and maximum weighted bipartite matching algorithm is proposed to predict kinase-substrate relationship. In PKSPS-Seq, phosphorylation sequence enrichment analysis is used to analyze the similarity of local sequences around phosphorylation sites and predict the kinase of specific phosphorylation sites (KSP). PKSPS has been proved to be more effective than the PKSPS-Net or PKSPS-Seq on different sets of kinases. Further comparison results show that the PKSPS method performs better than existing methods. Finally, the case study demonstrates the effectiveness of the PKSPS in predicting kinases of specific phosphorylation sites. The open source code and data of the PKSPS can be obtained from https://github.com/guoxinyunncu/PKSPS.


Assuntos
Algoritmos , Proteínas Quinases , Humanos , Fosforilação , Mapas de Interação de Proteínas , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Software
10.
J Transl Med ; 22(1): 224, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429799

RESUMO

BACKGROUND: In recent years, natural bone extracellular matrix (ECM)-inspired materials have found widespread application as scaffolds for bone tissue engineering. However, the challenge of creating scaffolds that mimic natural bone ECM's mechanical strength and hierarchical nano-micro-macro structures remains. The purposes of this study were to introduce an innovative bone ECM-inspired scaffold that integrates a 3D-printed framework with hydroxyapatite (HAp) mineralized graphene oxide-collagen (GO-Col) microscaffolds and find its application in the repair of mandibular bone defects. METHODS: Initially, a 3D-printed polycaprolactone (PCL) scaffold was designed with cubic disks and square pores to mimic the macrostructure of bone ECM. Subsequently, we developed multi-layer mineralized GO-Col-HAp microscaffolds (MLM GCH) to simulate natural bone ECM's nano- and microstructural features. Systematic in vitro and in vivo experiments were introduced to evaluate the ECM-inspired structure of the scaffold and to explore its effect on cell proliferation and its ability to repair rat bone defects. RESULTS: The resultant MLM GCH/PCL composite scaffolds exhibited robust mechanical strength and ample assembly space. Moreover, the ECM-inspired MLM GCH microscaffolds displayed favorable attributes such as water absorption and retention and demonstrated promising cell adsorption, proliferation, and osteogenic differentiation in vitro. The MLM GCH/PCL composite scaffolds exhibited successful bone regeneration within mandibular bone defects in vivo. CONCLUSIONS: This study presents a well-conceived strategy for fabricating ECM-inspired scaffolds by integrating 3D-printed PCL frameworks with multilayer mineralized porous microscaffolds, enhancing cell proliferation, osteogenic differentiation, and bone regeneration. This construction approach holds the potential for extension to various other biomaterial types.


Assuntos
Durapatita , Grafite , Osteogênese , Ratos , Animais , Durapatita/análise , Durapatita/metabolismo , Durapatita/farmacologia , Alicerces Teciduais/química , Regeneração Óssea , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Engenharia Tecidual , Poliésteres/química , Mandíbula , Impressão Tridimensional
11.
Artigo em Inglês | MEDLINE | ID: mdl-39037442

RESUMO

Two Gram-stain-negative, aerobic, milk-white coloured, non-motile, short rod-shaped bacteria, designated as strains SYSU D60010T and SYSU D60012T, were isolated from sand samples collected from the Taklimakan Desert of Xinjiang Province in China. Both strains were positive for oxidase, catalase and nitrate reduction, but negative for amylase, H2S production, hydrolysis of gelatin and cellulase. Strains SYSU D60010T and SYSU D60012T grew well at 28 °C, at pH 7 and had the same NaCl tolerance range of 0-1 % (w/v). The major fatty acids (>5 %) of strains SYSU D60010T and SYSU D60012T were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), iso-C19 : 0 cyclo ω8c, C16 : 0 and iso-C18 : 1 2-OH. Q-10 was the only respiratory ubiquinone. Strains SYSU D60010T and SYSU D60012T showed high 16S rRNA gene sequence similarities to Aestuariivirga litoralis SYSU M10001T (94.2 and 94.1 %), Rhodoligotrophos jinshengii BUT-3T (92.0 and 91.9 %) and Rhodoligotrophos appendicifer 120-1T (91.8 and 91.7 %), and the genomes were 7.4 and 5.8 Mbp in size with DNA G+C contents of 62.8 and 63.0 mol%, respectively. Phylogenetic, phenotypic and chemotaxonomic characteristics indicated that these two strains represent a novel genus and two novel species within the family Aestuariivirgaceae. We propose the name Taklimakanibacter deserti gen. nov., sp. nov. for strain SYSU D60010T, representing the type strain of this species (=KCTC 52783T =NBRC 113344T) and Taklimakanibacter lacteus gen. nov., sp. nov. for strain SYSU D60012T, representing the type strain of this species (=KCTC 52785T=NBRC 113128T).


Assuntos
Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Clima Desértico , Ácidos Graxos , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA , Microbiologia do Solo , RNA Ribossômico 16S/genética , Ácidos Graxos/química , DNA Bacteriano/genética , China , Ubiquinona/análogos & derivados , Areia/microbiologia
12.
Inorg Chem ; 63(32): 15061-15071, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39091042

RESUMO

A novel ZnO/CuI/Cu foam electrode was constructed, which demonstrated excellent photoelectrocatalytic activity for the self-Fenton degradation of tetracycline in water. The H2O2 yield was 405.0 µmol L-1 over ZnO/CuI/Cu foam (CIZ-3) under light irradiation (100 mW cm-2) for 5 h at -1.23 V (vs NHE), which was 1.7 times higher than that of ZnO/Cu foam and 1.6 times higher than that of CuI/Cu foam, respectively. The 99.0% of tetracycline was degraded by CIZ-3 due to its efficient yield of H2O2 to self-catalyzed generation of •OH. The results of the open-circuit potential between CuI and ZnO displayed that the electrons from the conduction band of CuI flowed to ZnO and the holes from the valence band of ZnO migrated to CuI. As a result, the photogenerated electron-hole pairs of ZnO/CuI were efficiently separated, which greatly promoted the photoelectrocatalytic activity of ZnO/CuI/foam. The toxicity of the aqueous tetracycline solution was significantly reduced by observing the growth of Escherichia coli in the treated wastewater.

13.
Environ Sci Technol ; 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39235142

RESUMO

Taste and odor (T&O) are among the most frequently encountered aesthetic issues in drinking water. While fungi have been reported to produce offensive odors, their contribution to T&O in drinking water remains understudied and often overlooked. In this study, the profiles of fungal community and odorants produced by 10 native fungal isolates were investigated in 36 samples collected from two drinking water treatment plants and a premise plumbing system. A total of 17 odorants were identified with Penicillium, Aspergillus, Paecilomyces, and Alternaria genera exhibiting the highest odorant yields. Significant concentrations of musty/earthy compounds were produced by these fungal isolates, such as 2-methylisoborneol (2-MIB) (26-256 ng/L), geosmin (10-13 ng/L), and 2-isobutyl-3-methoxy-pyrazine (IBMP) (3-13 ng/L). The high odor activity value of the odorants primarily occurred within 4 d, while toxicity continued to increase during the 8 d incubation. UV treatment in premise plumbing significantly (p < 0.05) reduced the gene read counts of Ascomycota phylum, Aspergillus spp., Fusarium spp., Rhizopus spp., and Trichoderma spp., by 2.3-4.0 times. These findings underscore the previously underestimated role of fungi in contributing to T&O issues in drinking water and corresponding risks to consumers and indicate UV as a promising strategy for fungal control in drinking water.

14.
Environ Sci Technol ; 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38329941

RESUMO

Perfluoroalkyl substances (PFAS) are a class of persistent organic pollutants known as "forever chemicals". Currently, the hydrated electron-based advanced reduction process (ARP) holds promise for the elimination of PFAS. However, the efficiency of ARP is often challenged by an oxygen-rich environment, resulting in the consumption of hydrated electron source materials in exchange for the high PFAS decomposition efficiency. Herein, we developed a ternary system constructed by indole and isopropyl alcohol (IPA), and the addition of IPA significantly enhanced the PFOA degradation and defluorination efficiency in the presence of low-concentration indole (<0.4 mM). Meanwhile, opposite results were obtained with a higher amount of indole (>0.4 mM). Further exploring the molecular mechanism of the reaction system, the addition of IPA played two roles. On one hand, IPA built an anaerobic reaction atmosphere and improved the yield and utilization efficiency of hydrated electrons with a low concentration of indole. On the other hand, IPA suppressed the attraction between indole and PFOA, thus reducing the hydrated electron transfer efficiency, especially with more indole. In general, the indole/PFAS/IPA system significantly improved the PFAS destruction efficiency with a small amount of hydrated electron donors, which provided new insights for development of simple and efficient techniques for the treatment of PFAS-contaminated wastewater.

15.
Environ Sci Technol ; 58(13): 5832-5843, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38511412

RESUMO

Photosensitizer-mediated abiotic oxidation of Mn(II) can yield soluble reactive Mn(III) and solid Mn oxides. In eutrophic water systems, the ubiquitous algal extracellular organic matter (EOM) is a potential photosensitizer and may have a substantial impact on the oxidation of Mn(II). Herein, we focused on investigating the photochemical oxidation process from Mn(II) to solid Mn oxide driven by EOM. The results of irradiation experiments demonstrated that the generation of Mn(III) intermediate was crucial for the successful photo oxidization of Mn(II) to solid Mn oxide mediated by EOM. EOM can serve as both a photosensitizer and a ligand, facilitating the formation of the Mn(III)-EOM complex. The complex exhibited excellent efficiency in removing 17α-ethinylestradiol. Furthermore, the complex underwent decomposition as a result of reactions with reactive intermediates, forming a solid Mn oxide. The presence of nitrate can enhance the photochemical oxidation process, facilitating the conversion of Mn(II) to Mn(III) and then to solid Mn oxide. This study deepens our grasp of Mn(II) geochemical processes in eutrophic water and its impact on organic micropollutant fate.


Assuntos
Etinilestradiol , Óxidos , Óxidos/química , Fármacos Fotossensibilizantes , Compostos de Manganês/química , Oxirredução , Água/química
16.
Environ Sci Technol ; 58(25): 11140-11151, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38867458

RESUMO

Microplastic records from lake cores can reconstruct the plastic pollution history. However, the associations between anthropogenic activities and microplastic accumulation are not well understood. Huguangyan Maar Lake (HML) is a deep-enclosed lake without inlets and outlets, where the sedimentary environment is ideal for preserving a stable and historical microplastic record. Microplastic (size: 10-500 µm) characteristics in the HML core were identified using the Laser Direct Infrared Imaging system. The earliest detectable microplastics appeared unit in 1955 (1.1 items g-1). The microplastic abundance ranged from n.d. to 615.2 items g-1 in 1955-2019 with an average of 134.9 items g-1. The abundance declined slightly during the 1970s and then increased rapidly after China's Reform and Opening Up in 1978. Sixteen polymer types were detectable, with polyethylene and polypropylene dominating, accounting for 23.5 and 23.3% of the total abundance, and the size at 10-100 µm accounted for 80%. Socioeconomic factors dominated the microplastic accumulation based on the random forest modeling, and the contributions of GDP per capita, plastic-related industry yield, and total crop yield were, respectively, 13.9, 35.1, and 9.3% between 1955-2019. The total crop yield contribution further increased by 1.7% after 1978. Coarse sediment particles increased with soil erosion exacerbated microplastics discharging into the sediment.


Assuntos
Monitoramento Ambiental , Lagos , Microplásticos , China , Microplásticos/análise , Poluentes Químicos da Água/análise , Plásticos , Sedimentos Geológicos/química
17.
Antonie Van Leeuwenhoek ; 117(1): 108, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39080041

RESUMO

A novel rod-shaped bacterium, designated as strain SYSU D60015T that formed yellowish colonies was isolated from a sandy soil collected from the Kumtag Desert in Xinjiang, China. Cells were Gram-stain-negative, oxidase-positive, catalase-negative and motile with a single polar flagellum. Growth optimum occurred between 28 and 37 °C, pH 7.0 and with 0-0.5% (W/V) NaCl. The predominant cellular fatty acids (> 5%) were summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), C19:0 cyclo ω8c, C18:1 ω7c 11-methyl and C16:0. The polar lipid profile contained one phosphatidylethanolamine, one diphosphatidylglycerol, one phosphatidylglycerol, one unidentified phospholipid, three unidentified aminolipids, two unidentified aminophospholipids and seven unidentified lipids. The only respiratory quinone was ubiquinone-10. Based on 16S rRNA gene sequence phylogenetic analysis, strain SYSU D60015T was found to form a distinct linage within the family Sneathiellaceae, and had 16S rRNA gene sequence similarities of 90.8% to Taonella mepensis H1T, and 90.2% to Ferrovibrio denitrificans S3T. The genome of SYSU D60015T was 5.66 Mb in size with 68.2% of DNA G + C content. The low digital DNA-DNA hybridization (dDDH, 18.0%), average nucleotide identity (ANI, 77.5%) and amino acid identity (AAI, 56.0%) values between SYSU D60015T and Ferrovibrio terrae K5T indicated that SYSU D60015T might represent a distinct genus. Based on the phylogenetic, phenotypic, chemotaxonomic and genomic data, we propose Desertibaculum subflavum gen. nov., sp. nov. as a novel species of a new genus within the family Sneathiellaceae. The type strain is SYSU D60015T (= NBRC 112952T = CGMCC 1.16256T).


Assuntos
Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Clima Desértico , Ácidos Graxos , Filogenia , RNA Ribossômico 16S , Microbiologia do Solo , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , China , Ácidos Graxos/análise , Ácidos Graxos/química , Análise de Sequência de DNA , Fosfolipídeos/análise , Fosfolipídeos/química
18.
Appl Opt ; 63(16): 4473-4479, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38856629

RESUMO

This study employed a two-step hydrothermal reduction process and freeze-drying technique. Initially, carbon nanosphere composite aerogels (CNSs) were synthesized through the hydrothermal reduction of glucose. Subsequently, boron-doped graphene/carbon nanosphere composite aerogel (BGA/CNS) was prepared by utilizing graphene oxide (GO) and boric acid as carbon (C) and boron (B) sources, respectively, in conjunction with CNS. The photo-enhanced thermionic electron emission (PETE) performance of the samples was assessed using a custom-made device. Boron atom doping was found to modulate the bandgap of graphene aerogel and induce P-type semiconductor characteristics, while the addition of CNSs increased its specific surface area, thereby enhancing its photoelectric properties. The results indicated that BGA/CNS-8h exhibited superior PETE effects, with a short-circuit current, open-circuit voltage, and maximum power of 5.81 µA, -2.10V, and-1.57µW.

19.
Dermatol Surg ; 50(9): 825-828, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38687899

RESUMO

BACKGROUND: The presence of scalp nevi in children frequently causes apprehension, leading physicians and parents to consider unnecessary biopsies or excisions of scalp nevi in children. There are limited data on the dermoscopic characteristics of scalp nevi in Chinese children. OBJECTIVE: The aim of this study was to comprehensively analyze the clinical and dermoscopic features of scalp nevi in this specific population of Chinese pediatric patients, with a focus on a single pediatric dermatologic surgery practice. METHODS: This retrospective cohort study investigated patients who underwent surgical excision of scalp nevi. All patients underwent dermoscopy with photographic documentation. RESULTS: Seventy-two scalp nevi in 56 Chinese children were included. Notably, no melanoma cases were detected. The parietal region (35, 48.6%) was the most frequently affected anatomical site. Clinical asymmetry was more prevalent in nevi with a diameter exceeding 6 mm ( p < .05). The predominant dermoscopic pattern observed was the globular pattern (50, 69.4%) while an intriguing rarity of a reverse-eclipse pattern (1, 1.4%). CONCLUSION: This study revealed that scalp nevi in Chinese children usually did not exhibit concerning behavior. Increasing awareness of the clinical characteristics, dermoscopic features, and the natural progression of scalp nevi in children can potentially help reduce unnecessary surgical interventions.


Assuntos
Dermoscopia , Nevo , Couro Cabeludo , Neoplasias Cutâneas , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , China/epidemiologia , População do Leste Asiático , Neoplasias de Cabeça e Pescoço/cirurgia , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Nevo/diagnóstico por imagem , Nevo/patologia , Nevo/cirurgia , Estudos Retrospectivos , Couro Cabeludo/patologia , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/cirurgia
20.
BMC Health Serv Res ; 24(1): 1089, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39294738

RESUMO

BACKGROUND: Pharmacogenetics/pharmacogenomics (PGx) focuses on the genetic variation that causes the heterogeneity of pharmacokinetics and drug response among individuals and has the potential to predict individual efficacy and/or side effects. This study aims to investigate and understand the implementation of genetic testing for the personalized medication (GTPM) in children's hospitals in Mainland China. METHODS: A survey was conducted on 50 children's hospitals from 31 provinces, municipalities, and autonomous regions across Mainland China, and statistical analysis and recommendations were made. RESULTS: Questionnaire response was rate of 76.0% (38/50). Data from 15 hospitals conducting GTPM were included in this study, but only 6 hospitals had offered PGx tests for no less than five drug-related genes, and only 5 hospitals had covered more than ten drugs, which was a small scale overall. 20.0% of the laboratories did not conduct internal quality control, and 33.3% did not participate in inter-laboratory quality assessment. 46.7% of the practitioners did not receive external training. The primary goal for GTPM was to optimize drug dosage in the 15 hospitals, while the main challenge for GTPM was the implementation cost. CONCLUSION: Although GTPM in pediatrics has made major progress in Mainland China in recent years, there were still various problems in terms of software, hardware configuration, personnel allocation, business scale, quality control, and result interpretation. This requires joint efforts of health administration, medical insurance departments, researchers, and hospitals to promote and improve GTPM.


Assuntos
Medicina de Precisão , Humanos , China , Criança , Medicina de Precisão/métodos , Inquéritos e Questionários , Testes Farmacogenômicos , Hospitais Pediátricos , Farmacogenética , População do Leste Asiático
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