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1.
J Transl Med ; 22(1): 396, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38685022

RESUMEN

BACKGROUND: The aim of this study was to assess the microbial variations and biomarkers in the vaginal and oral environments of patients with human papillomavirus (HPV) and cervical cancer (CC) and to develop novel prediction models. MATERIALS AND METHODS: This study included 164 samples collected from both the vaginal tract and oral subgingival plaque of 82 women. The participants were divided into four distinct groups based on their vaginal and oral samples: the control group (Z/KZ, n = 22), abortion group (AB/KAB, n = 17), HPV-infected group (HP/KHP, n = 21), and cervical cancer group (CC/KCC, n = 22). Microbiota analysis was conducted using full-length 16S rDNA gene sequencing with the PacBio platform. RESULTS: The vaginal bacterial community in the Z and AB groups exhibited a relatively simple structure predominantly dominated by Lactobacillus. However, CC group shows high abundances of anaerobic bacteria and alpha diversity. Biomarkers such as Bacteroides, Mycoplasma, Bacillus, Dialister, Porphyromonas, Anaerococcus, and Prevotella were identified as indicators of CC. Correlations were established between elevated blood C-reactive protein (CRP) levels and local/systemic inflammation, pregnancy, childbirth, and abortion, which contribute to unevenness in the vaginal microenvironment. The altered microbial diversity in the CC group was confirmed by amino acid metabolism. Oral microbial diversity exhibited an inverse pattern to that of the vaginal microbiome, indicating a unique relationship. The microbial diversity of the KCC group was significantly lower than that of the KZ group, indicating a link between oral health and cancer development. Several microbes, including Fusobacterium, Campylobacter, Capnocytophaga, Veillonella, Streptococcus, Lachnoanaerobaculum, Propionibacterium, Prevotella, Lactobacillus, and Neisseria, were identified as CC biomarkers. Moreover, periodontal pathogens were associated with blood CRP levels and oral hygiene conditions. Elevated oral microbial amino acid metabolism in the CC group was closely linked to the presence of pathogens. Positive correlations indicated a synergistic relationship between vaginal and oral bacteria. CONCLUSION: HPV infection and CC impact both the vaginal and oral microenvironments, affecting systemic metabolism and the synergy between bacteria. This suggests that the use of oral flora markers is a potential screening tool for the diagnosis of CC.


Asunto(s)
Microbiota , Boca , Infecciones por Papillomavirus , Neoplasias del Cuello Uterino , Vagina , Humanos , Femenino , Vagina/microbiología , Vagina/virología , Neoplasias del Cuello Uterino/microbiología , Neoplasias del Cuello Uterino/virología , Infecciones por Papillomavirus/virología , Infecciones por Papillomavirus/microbiología , Boca/microbiología , Boca/virología , Adulto , Persona de Mediana Edad , Papillomaviridae/aislamiento & purificación , Papillomaviridae/genética , ARN Ribosómico 16S/genética , Virus del Papiloma Humano
2.
Artículo en Inglés | MEDLINE | ID: mdl-38466063

RESUMEN

Objective: The clinical effect of tonsillectomy with the preservation of tonsillar capsule and stent tissue and punctuated suture of tonsillar capsule and stent tissue was analyzed retrospectively. Methods: From January 2013 to January 2022, a total of 960 patients underwent tonsillectomy, consisting of 530 males and 430 females with ages ranging from 4 to 60 years (median age: 11 years). The capsule and scaffold tissues were preserved in all patients during the operation, and the surrounding mucosa, capsule, and scaffold tissues were sutured without tension. Indexes such as operation time, intraoperative blood loss, tonsillar white membrane, incidence of postoperative bleeding, postoperative pain score, and incidence of tonsillar remnant were recorded, and the school attendance of children (≤12 years old) was recorded. Results: The mucosal covering of tonsillar fossa healed well in all patients, and the sutures were completely removed at 4 weeks after reexamination. All patients were followed up for 1-8 years, and there was no residual hyperplasia or residual inflammation. Children under 12 years old could return to school 4 days after surgery without any postoperative complications. Conclusion: Tonsillectomy, preserving the tonsillar capsule and scaffold tissue followed by punctate suturing, offered several advantages: it resulted in less intraoperative blood loss and postoperative pain. Patients could resume a normal diet 6 hours after the surgery without an increased risk of complications. Moreover, it significantly reduced the risk of postoperative bleeding.

3.
Eur Arch Otorhinolaryngol ; 281(1): 237-243, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37603052

RESUMEN

PURPOSE: Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited disorder that involves epistaxis, mucocutaneous telangiectases, and visceral arteriovenous malformations (AVMs). This study aims to investigate the genetic causes in a Chinese family with HHT. METHODS: HHT was confirmed according to Curaçao's diagnostic criteria. Three patients diagnosed with HHT and healthy members were recruited. Whole-exome sequencing (WES) and sanger sequencing were performed to define the patient's genetically pathogenic factor. RESULTS: The proband presented with recurrent epistaxis, hepatopulmonary arteriovenous malformation, and adenocarcinoma. A novel frameshift mutation (c.1376_1377delAC, p.H459Lfs*41) of the ENG gene was revealed in affected individuals by WES. There was no report of this variant and predicted to be highly damaging by causing truncation of the ENG protein. CONCLUSION: We report a novel variant in the ENG gene in Chinese that extends the mutational and phenotypic spectra of the ENG gene, and also demonstrates the feasibility of WES in the application of genetic diagnosis of HHT.


Asunto(s)
Mutación del Sistema de Lectura , Telangiectasia Hemorrágica Hereditaria , Humanos , Endoglina/genética , Telangiectasia Hemorrágica Hereditaria/complicaciones , Telangiectasia Hemorrágica Hereditaria/diagnóstico , Telangiectasia Hemorrágica Hereditaria/genética , Epistaxis , Mutación , China
4.
Small ; 19(23): e2207666, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36703516

RESUMEN

H2 O2 -fueled micromotors are state-of-the-art mobile microreactors in environmental remediation. In this work, a magnetic FeOx @MnO2 @SiO2 micromotor with multi-functions is designed and demonstrated its catalytic performance in H2 O2 /peroxymonosulfate (PMS) activation for simultaneously sustained motion and organic degradation. Moreover, this work reveals the correlations between catalytic efficiency and motion behavior/mechanism. The inner magnetic FeOx nanoellipsoids primarily trigger radical species (• OH and O2 •- ) to attack organics via Fenton-like reactions. The coated MnO2 layers on FeOx surface are responsible for decomposing H2 O2 into O2 bubbles to provide a propelling torque in the solution and generating SO4 •- and • OH for organic degradation. The outer SiO2 microcapsules with a hollow head and tail result in an asymmetrical Janus structure for the motion, driven by O2 bubbles ejecting from the inner cavity via the opening tail. Intriguingly, PMS adjusts the local environment to control over-violent O2 formation from H2 O2 decomposition by occupying the Mn sites via inter-sphere interactions and enhances organic removal due to the strengthened contacts and Fenton-like reactions between inner FeOx and peroxides within the microreactor. The findings will advance the design of functional micromotors and the knowledge of micromotor-based remediation with controlled motion and high-efficiency oxidation using multiple peroxides.

5.
Chembiochem ; 24(10): e202300147, 2023 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-37041126

RESUMEN

Phase separation is a crucial biophysical process that governs cellular signaling and function. This process allows biomolecules to separate and form membraneless compartments in response to both extra- and intra-cellular stimuli. Recently, the identification of phase separation in different immune signaling pathways, including the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway, has shed light on its tight association with pathological processes such as viral infections, cancers, and inflammatory diseases. In this review, we present the phase separation in cGAS-STING signaling, along with its related cellular regulatory functions. Furthermore, we discuss the introduction of therapeutics targeting cGAS-STING signaling, which plays a pivotal role in cancer progression.


Asunto(s)
ADN , Transducción de Señal , ADN/metabolismo , Transducción de Señal/genética , Nucleotidiltransferasas/metabolismo , Inmunidad Innata
6.
Pestic Biochem Physiol ; 197: 105680, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38072537

RESUMEN

We applied a new RNA interference (RNAi) system using rolling circle transcription (RCT) technology to generate RNA microspheres (RMS) for targeting two key chitin synthetic pathway genes [chitin synthase A (CHSA), chitin synthase B (CHSB)] in the larvae of the oriental armyworm (Mythimna separate), a RNAi-unsusceptible agriculturally important lepidopteran pest. Feeding the third-instar larvae with the RMS-CHSA- or RMS-CHSB-treated corn leaf discs suppressed the expression of CHSA by 81.7% or CHSB by 88.1%, respectively, at 72 h. The silencing of CHSA consequently affected the larval development, including the reduced body weight (54.0%) and length (41.3%), as evaluated on the 7th day, and caused significant larval mortalities (51.1%) as evaluated on the 14th day. Similar results were obtained with the larvae fed RMS-CHSB. We also compared RNAi efficiencies among different strategies: 1) two multi-target RMS [i.e., RMS-(CHSA + CHSB), RMS-CHSA + RMS-CHSB], and 2) multi-target RMS and single-target RMS (i.e., either RMS-CHSA or RMS-CHSB) and found no significant differences in RNAi efficiency. By using Cy3-labeled RMS, we confirmed that RMS can be rapidly internalized into Sf9 cells (<6 h). The rapid cellular uptake of RMS accompanied with significant RNAi efficiency through larval feeding suggests that the RCT-based RNAi system can be readily applied to study the gene functions and further developed as bio-pesticides for insect pest management. Additionally, our new RNAi system takes the advantage of the microRNA (miRNA)-mediated RNAi pathway using miRNA duplexes generated in vivo from the RMS by the target insect. The system can be used for RNAi in a wide range of insect species, including lepidopteran insects which often exhibit extremely low RNAi efficiency using other RNAi approaches.


Asunto(s)
MicroARNs , Mariposas Nocturnas , Animales , Interferencia de ARN , Quitina Sintasa/genética , Quitina Sintasa/metabolismo , Microesferas , Mariposas Nocturnas/genética , Mariposas Nocturnas/metabolismo , Insectos/genética , Larva/metabolismo , ARN Bicatenario
7.
Int J Mol Sci ; 24(2)2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36674895

RESUMEN

Calcium/calmodulin-dependent protein kinase (CaMK), a key downstream target protein in the Ca2+ signaling pathway of eukaryotes, plays an important regulatory role in the growth, development and pathogenicity of plant fungi. Three AaCaMKs (AaCaMK1, AaCaMK2 and AaCaMK3) with conserved PKC_like superfamily domains, ATP binding sites and ACT sites have been cloned from Alternaria alternata, However, their regulatory mechanism in A. alternata remains unclear. In this study, the function of the AaCaMKs in the development, infection structure differentiation and pathogenicity of A. alternata was elucidated through targeted gene disruption. The single disruption of AaCaMKs had no impact on the vegetative growth and spore morphology but significantly influenced hyphae growth, sporulation, biomass accumulation and melanin biosynthesis. Further expression analysis revealed that the AaCaMKs were up-regulated during the infection structure differentiation of A. alternata on hydrophobic and pear wax substrates. In vitro and in vivo analysis further revealed that the deletion of a single AaCaMKs gene significantly reduced the A. alternata conidial germination, appressorium formation and infection hyphae formation. In addition, pharmacological analysis confirmed that the CaMK specific inhibitor, KN93, inhibited conidial germination and appressorium formation in A. alternata. Meanwhile, the AaCaMKs genes deficiency significantly reduced the A. alternata pathogenicity. These results demonstrate that AaCaMKs regulate the development, infection structure differentiation and pathogenicity of A. alternata and provide potential targets for new effective fungicides.


Asunto(s)
Fungicidas Industriales , Pyrus , Pyrus/microbiología , Virulencia/genética , Alternaria , Fungicidas Industriales/farmacología , Fungicidas Industriales/metabolismo
8.
J Appl Microbiol ; 133(4): 2631-2641, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35870147

RESUMEN

AIMS: Calmodulin (CaM), acts as a kind of multifunctional Ca2+ sensing protein, which is ubiquitous in fungi, is highly conserved across eukaryotes and is involved in the regulation of a range of physiological processes, including morphogenesis, reproduction and secondary metabolites biosynthesis. Our aim was to understand the characteristics and functions of AaCaM in Alternaria alternata, the causal agent of pear black spot. METHODS AND RESULTS: A 450 bp cDNA sequence of AaCaM gene of A. alternata was cloned by the PCR homology method. Sequence analysis showed that this protein encoded by AaCaM was a stable hydrophilic protein and had a high similarity to Neurospora crassa (CAA50271.1) and other fungi. RT-qPCR analysis determined that AaCaM was differentially upregulated during infection structural differentiation of A. alternata both on hydrophobic and pear wax extract-coated surface, with a 3.37-fold upregulation during the hydrophobic induced appressorium formation period (6 h) and a 1.46-fold upregulation during the infection hyphae formation period (8 h) following pear wax induction. Pharmaceutical analysis showed that the CaM-specific inhibitor, trifluoperazine (TFP), inhibited spore germination and appressorium formation, and affected toxins and melanin biosynthesis in A. alternata. CONCLUSIONS: AaCaM plays an important role in regulating infection structure differentiation and secondary metabolism of A. alternata. SIGNIFICANCE AND IMPACT OF STUDY: Our study provides a theoretical basis for further in-depth investigation of the specific role of AaCaM in the calcium signalling pathway underlying hydrophobic and pear wax-induced infection structure differentiation and pathogenicity of A. alternata.


Asunto(s)
Pyrus , Alternaria/metabolismo , Calcio/metabolismo , Calmodulina/genética , Calmodulina/metabolismo , ADN Complementario/metabolismo , Melaninas/metabolismo , Preparaciones Farmacéuticas , Enfermedades de las Plantas/microbiología , Pyrus/genética , Pyrus/metabolismo , Pyrus/microbiología , Trifluoperazina/metabolismo
9.
Angew Chem Int Ed Engl ; 61(38): e202205509, 2022 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-35866521

RESUMEN

Targeted protein degradation via proteasomal and lysosomal pathways is a promising therapeutic approach, and proteins in cytoplasm or on the cell membrane can be easily contacted and have become the major targets. However, degradation of disease-related proteins that exist in membrane-bound organelles (MBO) such as the endoplasmic reticulum (ER) remains unsolved due to the membrane limits. Here we describe a DNA nanodevice that shows ER targeting capacity and undergoes new intracellular degradation via the autophagy-dependent pathway. Then the DNA nanostructure functionalized with specific ligands is used to selectively catch ER-localized proteins and then transport them to the lysosome for degradation. Through this technique, the degradation of both exogenous ER-resident protein (ER-eGFP) and endogenous overexpressed molecular chaperone (glucose-regulated protein 78) in cancer cells has been successfully executed with high efficiency.


Asunto(s)
Autofagia , Retículo Endoplásmico , ADN/metabolismo , Retículo Endoplásmico/metabolismo , Lisosomas/metabolismo , Chaperonas Moleculares/metabolismo
10.
J Am Chem Soc ; 143(1): 471-480, 2021 01 13.
Artículo en Inglés | MEDLINE | ID: mdl-33347297

RESUMEN

Alkyl boronic acids and esters play an important role in the synthesis of C(sp3)-rich medicines, agrochemicals, and material chemistry. This work describes a new type of transition-metal-free mediated transformation to enable the construction of C(sp3)-rich and sterically hindered alkyl boron reagents in a practical and modular manner. The broad generality and functional group tolerance of this method is extensively examined through a variety of substrates, including synthesis and late-stage functionalization of scaffolds relevant to medicinal chemistry. The strategic significance of this approach, with alkyl boronic acids as linchpins, is demonstrated through various downstream functionalizations of the alkyl boron compounds. This two-step concurrent cross-coupling approach, resembling formal and flexible alkyl-alkyl couplings, provides a general entry to synthetically challenging high Fsp3-containing drug-like scaffolds.

11.
Small ; 17(50): e2100927, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34318613

RESUMEN

As emerging micro/nano-scale devices, micro/nanomotors have been innovatively applied in the environmental and biomedical applications. In this paper, the recent advances of Mn-based micro/nanomotors (Mn-micro/nanomotors) in catalytic oxidation of organic contaminants and the mechanisms in decomposition of H2 O2 (e.g., the generation of O2 bubbles and reactive oxygen species) are reviewed. The intrinsic characteristics and synthetic strategies of Mn-based materials are discussed, aiming to gain comprehensive understandings on the asymmetric design of micro/nanomotors. Mn-micro/nanomotors have many advantages such as flexible structures, biocompatibility, powerful motion, long lifetime, and low-cost as compared to noble-metal micro/nanomotors. These merits fulfil Mn-micro/nanomotors great promises from proof-of-concept studies to realistic applications, including pollutant decomposition, trace detection of heavy metal ions, oil removal, drug delivery, isolation of biological targets, and killing bacteria and cancer cells. The great flexibility in fabrication enables diverse and innovative strategies to address challenges for Mn-micro/nanomotors, including high consumption of H2 O2 and non-directional motion. Meanwhile, a perspective of Mn-micro/nanomotors in water remediation by coupling the motors with other Fenton/Fenton-like systems to enhance the catalytic activity and to yield more reactive oxygen species is presented. Directions to the design of on-demand H2 O2 -fueled Mn-micro/nanomotors for advanced purification of organic contaminants in aquatic systems are also proposed.


Asunto(s)
Manganeso , Nanotecnología , Catálisis , Iones , Movimiento (Física)
12.
Soft Matter ; 17(5): 1184-1188, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33527954

RESUMEN

A series of short intrinsically disordered polypeptide conjugated oligonucleotides (IDPOCs) were rationally developed and assembled into well-defined nanospheres. The nanospheres exhibited excellent reversible thermoresponsive regulation of their contraction and expansion. Furthermore, the nanospheres showed biocompatibility, drug encapsulation and effective cellular uptake.


Asunto(s)
Nanosferas , Oligonucleótidos , Péptidos , Temperatura
13.
Immunol Invest ; 50(2-3): 184-200, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32208776

RESUMEN

BACKGROUND: Tumor necrosis factor superfamily member 4 (TNFSF4) has significant role in modulating autoimmune diseases (ADs) and single nucleotide polymorphism (SNP) is also related with the susceptibility to some diseases. So a meta-analysis aimed at systematically assessing the associations between TNFSF4 polymorphisms (rs2205960 G > A, rs704840 T > G and rs844648 G > A) and ADs risk was performed in Asians. METHODS: Total 14 eligible articles published before March 2019 involving 35 studies, of which 21 studies (16,109 cases and 26,378 controls) for rs2205960 G > A, 8 studies (2,424 cases and 3,692 controls) for rs704840 T > G, and 6 studies (3,839 cases and 5,867 controls) for rs844648 G > A were included. Effects of the three respective polymorphisms on the susceptibility to ADs were estimated by pooling the odds ratios (ORs) with their corresponding 95% confidence interval (95% CI) in allelic, dominant, recessive, heterozygous and homozygous models. RESULTS: The overall analysis revealed that all the rs2205960 G > A, rs704840 T > G and rs844648 G > A polymorphisms could increase the risk of ADs in allelic, dominant, recessive, heterozygous and homozygous models. Furthermore, subgroup analysis showed that both rs2205960 G > A and rs704840 T > G were significantly associated with the susceptibility to systemic lupus erythematosus (SLE). What's more, statistically significant association between rs2205960 G > A polymorphism and primary Sjögren's syndrome (pSS) susceptibility was also observed in allelic, dominant and heterozygous models. CONCLUSIONS: This current meta-analysis suggested that all of the three TNFSF4 polymorphisms may be associated with ADs susceptibility in Asians.


Asunto(s)
Pueblo Asiatico , Enfermedades Autoinmunes/genética , Genotipo , Ligando OX40/genética , Enfermedades Autoinmunes/epidemiología , China/epidemiología , Frecuencia de los Genes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , India/epidemiología , Malasia/epidemiología , Polimorfismo de Nucleótido Simple
14.
Plant Dis ; 104(11): 2764-2767, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32897843

RESUMEN

Xanthomonas oryzae pv. oryzae is the causative agent of bacterial blight of rice and causes severe harvest loss and challenges to a stable food supply globally. In this study, a hypervirulent strain, LN4, compatible in rice varieties carrying Xa3, Xa4, xa13, and xa25 resistance genes, was used to generate DNA for nanopore sequencing. After assembly, the genome comprises a single chromosome of 5,012,583 bp, consisting of a total of 6,700 predicted coding sequences. Seventeen transcription activator-like effectors (TALEs) were encoded in the genome, of which two (Tal7 and Tal6c) were major TALEs. The approach and genome data provide information for the discovery of new virulence effectors and understanding of the virulence mechanism of TALEs in rice.


Asunto(s)
Oryza , Xanthomonas , Enfermedades de las Plantas , Efectores Tipo Activadores de la Transcripción , Xanthomonas/genética
15.
J Am Chem Soc ; 141(43): 17414-17420, 2019 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-31557015

RESUMEN

Gold(I) complexes are considered active species toward oxidative addition; current understanding indicates a different mechanism in contrast to other late transition metals, but a rational understanding of the reactivity profile is lacking. Herein, we propose that the accessibility of the gold(I) center to tri- or tetra-coordination is critical in the oxidative process involving a tri- or tetra-coordinate gold(I) with the oxidizing reagent as one of the ligands as an intermediate. A computational study of the geometry of (Phen)R3PAu(I)NTf2 complexes shows that the accessibility of such tricoordinate species shows a good correlation with the "trans influence" of phosphine ligands: the weak σ-donating phosphine ligands promote tricoordination of gold(I) complexes. The oxidative addition to the asymmetric tricoordinate (Phen)R3PAu(I)NTf2 complexes with alkynyl hypervalent iodine reagents was built. The kinetic profile of the oxidative addition exhibits a good relationship to the Hammett substituent parameter (ρ = 3.75, R2 = 0.934), in which the gold(I) complexes bearing less σ-donating phosphine ligands increase the rate of oxidative addition. The positive ρ indicates a high sensitivity of the oxidative addition to the trans influence. The reactivity profile of oxidative addition to a linear bis(pyridine)gold(I) complex further supports that the oxidative addition to gold(I) complexes is promoted by ligands with small trans influence.

16.
Chemistry ; 25(41): 9624-9628, 2019 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-31094025

RESUMEN

A gold(I)-catalyzed cascade cyclization-alkynylation of allenoates using alkynyl bromide to generate ß-alkynyl-γ-butenolides was investigated. Whereas alkynyl iodides afforded significant amounts of the homo-coupling of two lactone units, alkynyl bromides led to a selective reaction, and a broad functional group tolerance was observed. Under the optimized reaction conditions, it was possible to directly synthesize a large range of ß-alkynyl-γ-butenolides in moderate to good yields without the need for any external oxidant.

17.
Chemistry ; 25(20): 5158-5162, 2019 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-30791173

RESUMEN

Biological macromolecular machines perform impressive mechanical movements. F-adenosine triphosphate (ATP) synthase uses a proton gradient to generate ATP through mechanical rotations. Here, a programmed hexagonal DNA nanomachine, in which a three-armed DNA nanostructure (TAN) can perform stepwise rotations in the confined nanospace powered by DNA fuels, is demonstrated. The movement of TAN can precisely go through a 60° rotation, which is confirmed by atomic force microscopy, and each stepwise directional rotating is monitored by fluorescent measurements. Moreover, the rotary nanomachine is used to spatially organize cascade enzymes: glucose oxidase (GOx) and horseradish peroxidase (HRP) in four different arrangements. The multistep regulations of the biocatalytic activities are achieved by employing TAN rotations. This work presents a new prototype of rotary nanodevice with both angular and directional control, and provides a nanoscale mechanical engineering platform for the reactive molecular components, demonstrating that DNA-based framework may have significant roles in futuristic nanofactory construction.


Asunto(s)
ADN/química , Nanoestructuras/química , Adenosina Trifosfato/química , Glucosa Oxidasa/química , Peroxidasa de Rábano Silvestre/química , Nanotecnología , Rotación
18.
Angew Chem Int Ed Engl ; 58(6): 1823-1827, 2019 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-30417501

RESUMEN

Herein we report a highly selective photoredox C(sp3 )-H alkylation/arylation of ethers through the combination of a photo-organocatalyst (benzaldehyde) and a transition-metal catalyst (nickel). This method provides a simple and general strategy for the C(sp3 )-H alkylation/arylation of ethers. A selective late-stage modification of (-)-ambroxide has also been conducted to demonstrate the applicability of the method.

19.
Angew Chem Int Ed Engl ; 58(15): 5129-5133, 2019 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-30680917

RESUMEN

While gold-mediated synergistic catalytic processes involving transmetalations with other metals are well understood, AuI /AuIII cycles in these reactions are rarely reported. Herein a gold-catalyzed direct alkynylation of cyclopropenes is enabled by two operating catalytic cycles, an oxidative catalytic cycle involving an alkynyl AuIII complex formed by oxidative addition and one involving a silver-mediated C-H activation.

20.
Ecotoxicol Environ Saf ; 148: 89-96, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29031879

RESUMEN

The behaviors of nanoparticles rely on the aqueous condition such as natural organic matter (NOM). Therefore the presence of NOM would influence the interaction of nanoparticles with other substances possibly. Here, microcystin-LR (MC-LR) adsorption on iron oxide nanoparticles (IONPs) was studied in an aqueous solution with different types of NOM, including extracellular polymeric substances (EPS) from cyanobacteria and alginic acid sodium salt (AASS) from brown algae. Results revealed that EPS played an important role in stabilizing IONPs and in the toxin adsorption efficiency. The stability of IONPs was heavily depended on the concentration and type of NOM, which can affect the surface charge of IONPs significantly in solution. The enhanced stability of IONPs was due to the electrostatic interactions. Adsorption kinetics and isotherm studies confirmed that NOM can affect the IONPs' adsorption efficiency, and pseudo-second-order kinetics better explained this process. The removal efficiency for MC-LR decreased in the presence of NOM (Control > EPS-M1 > AASS > EPS-M9), indicating that NOM and MC-LR compete for limited adsorption sites. The presence of NOM in a eutrophic environment stabilized the IONPs while inhibiting the MC-LR removal efficiency. This investigation emphasized the negative effect of cyanobacterial EPS on the removal of microcystins when using magnetic separation technology. And this results could also be used to model the transportation of iron minerals carrying toxic substances in aqueous environment.


Asunto(s)
Agua Dulce/química , Sustancias Húmicas/análisis , Nanopartículas de Magnetita/química , Microcistinas/análisis , Contaminantes Químicos del Agua/análisis , Adsorción , Cianobacterias/química , Cinética , Toxinas Marinas , Modelos Teóricos
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