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1.
Gels ; 10(5)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38786221

RESUMO

It is difficult to plug the fracture water channeling of a fractured low-permeability reservoir during water flooding by using the conventional acrylamide polymer gel due to its weak mechanical properties. For this problem, micron graphite powder is added to enhance the comprehensive properties of the acrylamide polymer gel, which can improve the plugging effect of fracture water channeling. The chemical principle of this process is that the hydroxyl and carboxyl groups of the layered micron graphite powder can undergo physicochemical interactions with the amide groups of the polyacrylamide molecule chain. As a rigid structure, the graphite powder can support the flexible skeleton of the original polyacrylamide molecule chain. Through the synergy of the rigid and flexible structures, the viscoelasticity, thermal stability, tensile performance, and plugging ability of the new-type gel can be significantly enhanced. Compared with a single acrylamide gel, after adding 3000 mg/L of micrometer-sized graphite powder, the elastic modulus, the viscous modulus, the phase transition temperature, the breakthrough pressure gradient, the elongation at break, and the tensile stress of the acrylamide gel are all greatly improved. After adding the graphite powder to the polyacrylamide gel, the fracture water channeling can be effectively plugged. The characteristics of the networked water flow channel are obvious during the injected water break through the gel in the fracture. The breakthrough pressure of water flooding is high. The experimental results are an attempt to develop a new gel material for the water plugging of a fractured low-permeability reservoir.

2.
J Colloid Interface Sci ; 669: 23-31, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38703579

RESUMO

Although ordered porous carbon materials (PCMs) have shown promising potential in the field of electromagnetic wave absorption (EWA), creating multifunctional PCMs with outstanding microwave absorption performance remains a significant challenge. Herein, ordered porous carbon aerogels loaded with pea-pod-like nitrogen-doped carbon nanotubes (CNTs) were fabricated via orientation freeze-drying followed by high-temperature pyrolysis. The optimized aerogel exhibits extraordinary EWA performance with a broad effective absorption bandwidth of 7.68 GHz and exceptionally strong absorption of -91.58 dB at a low filling ratio of only 3 wt%, which is the largest absorption strength among all known aerogels to date. The exceptional EWA performance is attributed to the synergistic effect of abundant loss mechanisms resulting from a unique pod-like structure in ordered porous carbon aerogel, where nitrogen-doped CNTs encapsulate magnetic alloy nanoparticles. Optimized aerogel exhibits superior compressive elasticity, thermal insulation, and light weight, laying the groundwork for designing practical next-generation EWA materials.

3.
Mikrochim Acta ; 191(3): 144, 2024 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-38372819

RESUMO

A novel fluorescence "off-on" probe was developed using a boron difluoride-modified zinc metal-organic framework (Zn-MOF3) for sensitive determination of tetracycline (TC) and Al3+. The Zn-MOF3 has excellent optical property and good applicability in aqueous phase. The fluorescence recorded at 436 nm was quenched at the excitation wavelength of 336 nm. Signal-off detection of tetracycline via fluorescence quenching of Zn-MOF3 is based on the inner filter effect. Fluorescence on-off-on detection of Al3+ occurs via the specific binding between tetracycline and Al3+. The limits of detection for TC and Al3+ were 28.4 nM and 106.7 nM, respectively. This probe exhibited high selectivity which was used for the determination of TC and Al3+ with satisfied recoveries (89.8 to 105.6% for TC, 90.0 to 110.4% for Al3+) and good precision (< 5%) in milk. The developed sensor represents the first "off-on" system for fluorescence detection of TC and Al3+ based on Zn-MOF3 with a better aspect of the innovation.


Assuntos
Compostos de Boro , Estruturas Metalorgânicas , Zinco , Fluorescência , Tetraciclina , Antibacterianos
4.
Polymers (Basel) ; 15(24)2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38139884

RESUMO

To meet the escalating demand for oil and gas exploration in microporous reservoirs, it has become increasingly crucial to develop high-performance plugging materials. Through free radical grafting polymerization technology, a carboxymethyl chitosan grafted poly (oligoethylene glycol) methyl ether methyl methacrylate acrylic acid copolymer (CCMMA) was successfully synthesized. The resulting CCMMA exhibited thermoresponsive self-assembling behavior. When the temperature was above its lower critical solution temperature (LCST), the nanomicelles began to aggregate, forming mesoporous aggregated structures. Additionally, the electrostatic repulsion of AA chains increased the value of LCST. By precisely adjusting the content of AA, the LCST of CCMMA could be raised from 84.7 to 122.9 °C. The rheology and filtration experiments revealed that when the temperature surpassed the switching point, CCMMA exhibited a noteworthy plugging effect on low-permeability cores. Furthermore, it could be partially released as the temperature decreased, exhibiting temperature-switchable and self-adaptive plugging properties. Meanwhile, CCMMA aggregates retained their reversibility, along with thermal thickening behavior in the pores. However, more detailed experiments and analysis are needed to validate these claims, such as a comprehensive study of the CCMMA copolymer's physical properties, its interaction with the reservoir environment, and its performance under various conditions. Additionally, further studies are required to optimize its synthesis process and improve its efficiency as a plugging material for oil and gas recovery in microporous reservoirs.

5.
ACS Omega ; 8(38): 35066-35076, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37780003

RESUMO

In this study, we present an innovative intelligent polymer sealant designed to mitigate CO2 leakage during underground geological storage (CCUS). This sealant is formulated by cross-linking CO2-responsive polymers, specifically acrylamide (AM) and N-[3-(dimethylamino) propyl] methacrylamide (DMAPMA), with polyethylenimine (PEI) serving as the cross-linking agent. The polymer sealant's characteristics were systematically investigated, varying the CO2-responsive polymer content (1.5 wt %) and PEI content (0.1-0.6 wt %). A comprehensive analysis encompassing the rheological properties, thermal behavior, conductivity, and microstructures was conducted. Experimental results indicate that the polymer sealant exhibits excellent injectability, rapid response kinetics, thermal stability, and robust mechanical strength. Upon encountering CO2, the polymer system undergoes a transition from sol to gel state, forming a surface-smooth, uniformly porous three-dimensional (3D) network skeleton structure. Remarkably, the gel's modulus remains relatively unaffected by the shear frequency. Core fluid displacement experiments demonstrated a substantial sealing efficiency of 73.6% for CO2 and an impressive subsequent injection water sealing rate of 96.2%, underscoring its superior sealing and migration performance. In conclusion, the proposed CO2-responsive gel sealant exhibits an exceptional potential for successful utilization in CCUS operations. This advancement introduces a novel avenue to enhance the effectiveness of CO2-responsive gel sealants, thereby contributing to the advancement of CO2 leakage mitigation strategies in geological storage scenarios.

6.
Sensors (Basel) ; 23(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37836926

RESUMO

Incipient fault detection in a hydraulic system is a challenge in the condition monitoring community. Existing research mainly monitors abnormal working conditions in hydraulic systems by separately detecting the key working parameter, which often causes a high miss warning rate for incipient faults due to the oversight of parameter dependence. A principal component analysis provides an effective method for incipient fault detection by taking the correlation of multiple parameters into consideration, but this technique assumes the systems are Gaussian-distributed, making it invalid for a dynamic non-Gaussian system. In this paper, we combine a canonical variable analysis (CVA) and adaptive kernel density estimation (AKDE) for the early fault detection of nonlinear dynamic hydraulic systems. The collected hydraulic system data set was used to construct the typical variable space, and the state space and residual space are divided to represent the characteristics of different correlations between the two variables, which are quantitatively described using Hotelling's T2 and Q. In order to investigate the proper upper control limits, AKDE was utilised to estimate the underlying probability density functions of T2 and Q by taking the nonlinearity of the hydraulic system variables into consideration. The advantages of the proposed approach for incipient fault detection are illustrated via a marine power plant lubrication system.

7.
RSC Adv ; 13(34): 23505-23513, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37546225

RESUMO

In this work, novel adsorbent polyaniline-modified halloysite nanotubes (HNT@PA-2) were synthesized successfully by in situ polymerization to increase active adsorption sites. With the increase of the amount of aniline, the adsorption capacity of naproxen becomes higher. The optimal ratio of halloysite nanotubes to aniline was 1 : 2. The effects of adsorption conditions such as pH, mass of HNT@PA-2, time and initial concentration of naproxen were systematically researched. The optimum adsorption for naproxen was pH 9, mass 10 mg and contact time 4 h. The adsorption of naproxen conformed to the pseudo-first-order kinetic model, and the maximum adsorption capacity was 242.58 mg g-1 at 318 K. In addition, the effects of ionic strength and different heavy metals also were studied. Higher ionic strength of the system could influence the adsorption of naproxen. The effects of Al3+, Pb2+, Zn2+ and Co2+ ions on the adsorption of naproxen could be ignored, while Cu2+ and Fe3+ ions inhibited the process. The mechanisms for naproxen adsorbed by the HNT@PA-2 were π-π interaction, hydrogen bonding and hydrophobic reaction. Therefore, the HNT@PA-2 could be used for the treatment of medical wastewater for removing naproxen.

8.
Mater Horiz ; 10(9): 3791-3796, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37409589

RESUMO

The clinical applications of phototherapy nanomaterials are still limited due to concerns regarding their phototoxicity and efficacy. Herein, we report a novel type of D-π-A molecular backbone that induces type I/II photosensitivity and photodegradability by forming J-aggregates. The photodegradation rate can be regulated by changing the donor groups to regulate the photosensitivity of their aggregates because the photodegradability performance results from their oxidation by 1O2 generated by their type II photosensitivity. AID4 NPs possess faster photodegradation because of their better type I&II photosensitivity, which can also self-regulate by inhibiting type II and improving type I under hypoxic conditions. Moreover, they exhibited good photothermal and photoacoustic performance for improving their therapeutic effect by a synergistic effect and achieving photoacoustic imaging in vivo. The experimental result also showed that they can be effective for antibacterial and anti-tumor treatment and the photodegradation products of AID4 NPs possess low biological toxicity in the dark or under light. This study could provide a novel strategy for improving the safety and treatment effects of phototherapy.


Assuntos
Nanopartículas , Neoplasias , Fotoquimioterapia , Humanos , Terapia Fototérmica , Nanopartículas/uso terapêutico , Fotoquimioterapia/métodos , Fototerapia/métodos
9.
Curr Org Synth ; 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37005532

RESUMO

AIM: Organic electro-optic (EO) materials have recently gained considerable attention owing to their advantages compared to inorganic EO materials. Among different kinds of organic EO materials, organic EO molecular glass exhibits desired prospect because of its high chromophore loading density and large macroscopic EO activity. INTRODUCTION: The objective of this study is to design and synthesize a novel organic EO molecular glass JMG utilizing julolidine moiety as the electron donor, thiophene moiety as the conjugated bridge, trifluoromethyl substituted tricyanofuran derivate (Ph-CF3-TCF) as the electron acceptor. METHOD: The JMG's structure was characterized through NMR and HRMS. The photophysical property, glass transition temperature, first hyperpolarizability (ß) and dipole moment (µ) of JMG were determined through UV-vis spectra, DSC test and DFT calculation. RESULTS: JMG's Tg reached to 79 °C and it can form high-quality optical film. The theoretical calculation shows that the first hyperpolarizability (ß) and dipole moment (µ) of JMG were calculated to 730×10-30 esu and 21.898 D. After connecting poling with the poling voltage of 49 V/µm at 90 ℃for 10 min, the highest EO coefficient (r33) of the poled JMG films reached to 147 pm/V. CONCLUSION: A novel julolidine-based NLO chromophore with two tert-butyldiphenylsilyl (TBDPS) groups was successfully prepared and characterized. TBDPS group is introduced as the film-forming group, and it also plays the role of isolation group, which can suppress the electrostatic interaction between chromophores, improve the poling efficiency and further enhance the EO activity. The excellent performances endow JMG with potential applications in device fabrication.

10.
Chem Biodivers ; 20(4): e202300100, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36930226

RESUMO

'On Water'-promoted the three-component tandem Michael addition/D-A cycloaddition reaction in 80 °C at 3 h has been developed without employing any catalyst and organic solvent. The process allows facile access to polycyclic N-heterocycles derivatives contain indole and maleimide from easily accessible starting materials in moderate to high yields (up to 91 %). Compared with conventional reaction conditions, this reaction not only improves the reaction efficiency and rate but also minimizes the side reaction.


Assuntos
Água , Reação de Cicloadição , Catálise
11.
Sci Rep ; 13(1): 2238, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36755100

RESUMO

To investigate the effect of water on the mechanical properties and acoustic emission (AE) characteristics of coal in the failure and deformation processes. Coal samples of different content were subjected to uniaxial compression tests and AE signals were monitored. The characteristics of the AE signals were further analyzed using fractal analysis. The results show that saturated coal samples have substantially reduced mechanical properties such as uniaxial compressive strength (UCS), dissipation energy, peak stress, and elastic modulus. Under loading, stress-strain curves are characterized by five distinct stages: (1) compaction; (2) linear elastic; (3) crack stable propagation; (4) crack accelerating propagation; and (5) post-peak and residual stages. Using phase-space theory, a novel Grassberger Procaccia (GP) algorithm was utilized to find the AE fractal characteristics of coal samples in different stages. It is significant to note that AE energy does not exhibit fractal characteristics in either the first or second stages. Contrary to the first two stages, the third stage showed obvious fractal characteristics. Fractal analysis of AE time sequences indicates that fractal dimension values change as stress increases, indicating the initiation of complex microcracks in coal. In the fourth stage, the fractal dimension rapidly declines as the strength reaches its limit, indicating the occurrence of macrocracks. However, fractal dimensions continued to decrease further or increased slightly in the fifth stage. Consequently, the coal begins to collapse, potentially resulting in a disaster and failure. It is, therefore, possible to accurately predict coal and rock dynamic failures and microcrack mechanisms by observing the subsequent sudden drop in the correlation dimension of the AE signals in response to different stages of loading.

12.
Nat Prod Res ; : 1-6, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36718098

RESUMO

Four prenylated indole alkaloids (1-4) were targeted isolated from the mangrove rhizosphere soil-derived fungus Penicillium janthinellum HK1-6 by using molecular networking strategies. Among them, the planar structure and relative configuration of notoamide X (1) were elucidated by detailed analysis of the spectroscopic data especially the NOESY spectrum for the first time and its absolute configuration was determined by ECD spectrum. Furthermore, curated molecular networks of MS/MS data were generated with GNPS which allowed highlighting six prenylated indole alkaloids (5, 6, 8, 9, 11, 12) that had not previously been identified in this fungus and two (7, 10) that had never been observed in any fungus. The MS/MS fragmentation pathway of these prenylated indole alkaloids was summarized.

13.
World J Clin Cases ; 10(33): 12104-12115, 2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36483797

RESUMO

BACKGROUND: The therapeutic effects of a combination of Chinese medicines called Baihedihuang decoction (BD) have been clinically verified, although its molecular targets in breast cancer related anxiety remain unknown. AIM: To explore the molecular mechanisms of BD for breast cancer related anxiety treatment. METHODS: We used the Traditional Chinese Medicine Systems Pharmacology database to screen the active ingredients and potential targets of BD, and constructed the "drug-ingredient-target" network map with the help of Cytoscape 3.8 software. Also, we used the Online Mendelian Inheritance in Man, DrugBank, and Gencards databases to collect the disease targets of breast cancer related anxiety, and used the STRING platform to perform protein interaction analysis and construct the protein-protein interaction network. Metascape platform was used for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of key targets. Molecular docking technology was used to verify the drug component/target disease network. RESULTS: We screened 16 active ingredients of BD for breast cancer related anxiety, with 113 target proteins. There are 931 disease targets of breast cancer related anxiety, and finally, 43 key targets and 305 Kyoto Encyclopedia of Genes and Genomes pathways were generated. The main active ingredients of BD for breast cancer related anxiety are verbascoside, ß-sitosterol, stigmasterol, catalpol, etc. CDK2, TP53, HTR2A, ESR1, etc. are its key targets, and the main involved signaling pathways may include neuroactive ligand-receptor interaction pathway, 5-hydroxytryptaminergic synapse, P53 signaling pathway, cGMP-PKG signaling pathway, the cAMP signaling pathway, etc. Finally, molecular docking was performed with Vina software to validate the key active ingredients in BD with the selected key action targets. The molecular docking results showed that verbascoside, ß-sitosterol, stigmasterol and CDK2 could stably bind and interact through amino acid residues SER249, ARG260, PRO228, ALA282, SER276, LYS273, ASN272, etc. CONCLUSION: The therapeutic effect of BD for breast cancer related anxiety is multi-level, multi-target, and multi-pathway. The findings of this study provide ideas and basis for further research.

14.
Int J Gen Med ; 15: 8603-8615, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36545244

RESUMO

Objective: In the direction of evaluating the current status of outcome indicators and control group selection in randomized controlled studies of Chinese herbal compounding (such as Sini plus Renshen Decoction, Jianpifuzhengfang, Bufei Jianzhong Decoction, etc) for cancer-caused fatigue and to provide a reference for clinical studies of Chinese herbal compounding for cancer-caused fatigue. Methods: Randomized controlled studies of Chinese herbal medicine for cancer-caused fatigue in the midst of 2012 and 2022 were searched in CNKI, PubMed, and EMBASE databases on the China Knowledge Network, and the literature was screened using NoteExpress. Two researchers independently conducted the literature review, and then the studies that met the criteria were grouped and analyzed adopting qualitative analysis of outcome indicators and control groups. Results: A total of 70 randomized controlled studies that met the requirements were included, and after doing statistical analysis, it can draw to the conclusion that the risk of bias in the included studies was high; at the same time, the TCM evidence score scale, objective indicators, and safety indicators were underutilized; additionally, there were no uniform standards for the fatigue scale, and the selection of control groups lacked balance and consistency. Conclusion: The outcome indicators of TCM compound treatment of cancer-caused fatigue should be on the basis of the principle of "diagnosis and treatment" in TCM, the proportion of objective indicators should be exaggerated, as well as the interventions in the control group should be unified.

15.
World J Clin Cases ; 10(27): 9703-9713, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36186177

RESUMO

BACKGROUND: Gemcitabine plus nab-paclitaxel (GA) is a commonly used first-line treatment regimen for metastatic pancreatic cancer, and many studies will add a novel targeted agent to this regimen for improving patient survival rate. However, the clinical effectiveness of GA is the most controversial issue. AIM: To compare the efficacy and safety of GA regimen with a targeted agent and GA regimen. METHODS: Up to 1 December 2021, the eligible randomized controlled trials (RCTs) relating to GA and GA with a targeted agent were searched on PubMed, EMBASE and Cochrane Library for eligible data. We screened out appropriate studies for overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and toxicity, which had been pooled and finally analyzed by using Stata version 15.1. In addition, we use Reference Citation Analysis (https://www.referencecitationanalysis.com/) to collect the latest related literature to improve the latest cutting-edge research results. RESULTS: Seven RCTs involving 1544 patients (848 men and 696 women) were included. There were no significant differences between GA with a targeted agent and GA in PFS [hazard ratio (HR): 1.18 95% confidence interval (CI): 0.91-1.53], OS (HR: 1.12 95%CI: 0.99-1.27), and ORR (HR: 0.96 95%CI: 0.71-1.29). There was no notable difference in the two groups in grade 3/4 toxicity (fatigue, anemia, vomiting and neutropenia), whereas the incidence of grade 3/4 diarrhea considerably increased in GA with a targeted drug. CONCLUSION: Adding a novel targeted agent to the GA regimen did not improve survival rate of patients with metastatic pancreatic cancer.

16.
Sci Rep ; 12(1): 16360, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36180498

RESUMO

During the deformation and fracture process, the acoustic emission (AE) signals can be produced for the of coal, rock and other solid materials, which revealing the damage localization evolution process. The effect of gas adsorption and pressure can change mechanical properties of coal mass and affect its damage development. Based on this, the experimental system for gas-bearing coal loading and AE monitoring was constructed, to analyze AE response characteristics under the joint action of loading stress and gas pressure on coal specimen. Afterwards, the damage localization evolution process of coal mass was studied with the moment tensor inversion method. Results showed that temporal response of AE signals was closely related to the damage degree and loading level of coal specimen, which could reveal its local severe damage and final failure characteristics. The spatial distribution and spread trend of AE fracture events inside coal specimen could be calculated through the moment tensor inversion method. It was basically consistent with the results of crack expansion on the specimen surface. The zones, where fracture events occurred intensively, gathered and spread in a continuous trend, were conductive to forming the macrocrack belt macroscopically. It could be regarded as the hazard zone with dynamic failure occurrence. Moreover, when the coal specimen faced the critical failure, the precursor characteristics of AE response appeared with the shear fracture events dominated markedly. The study results provide a new research idea for revealing the damaging localization evolution process under the coupling effect of stress and gas and lay the application foundation.

17.
Dis Markers ; 2022: 5447017, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36118672

RESUMO

Background: Tryptophan 2,3-dioxygenase (TDO) encoded by TDO2, a rate-limiting enzyme in the kynurenine pathway, catabolizes tryptophan to kynurenine, evades immune surveillance, and promotes tumor growth. Although accumulating evidence suggests a crucial role of TDO2 during tumor formation and development, systematic evaluation of TDO2 across human cancers has rarely been reported. Methods: To shed more light on the role of TDO2 in human cancer, we explored the expression profiles of TDO2 and identified its prognostic value in pancancer analysis through TCGA, CCLE, and GTEx databases. We further utilized TCGA data to evaluate the association between TDO2 and tumor immunological features, such as mismatch repair (MMR), tumor immune infiltration, immune checkpoint-related genes, tumor mutational burden (TMB), microsatellite instability (MSI), and DNA methyltransferase (DNMT). Results: TDO2 exhibited different expression levels in various cancer cell lines. Frequently, TDO2 was detected to be highly expressed in the majority of cancers. In addition, high TDO2 expression was correlated with an unfavorable prognosis for patients in KIRP, LGG, TGCT, and UVM. Moreover, high TDO2 expression level positively correlated with higher immune infiltration, especially dendritic cells. Additionally, there is a close relationship between TDO2 and immune checkpoint-related gene markers, such as LAIR1, CD276, NRP1, CD80, and CD86. Finally, correlation analysis has demonstrated a high-correlation between TDO2 and TMB, MSI, MMR, and DNMT of multiple cancer types. Conclusion: Therefore, our results suggest that TDO2 can function as a potential prognostic biomarker due to its role in tumor immunity regulation.


Assuntos
Neoplasias , Triptofano Oxigenase , Antígenos B7/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , DNA , Humanos , Imunoterapia , Cinurenina/genética , Cinurenina/metabolismo , Metiltransferases/genética , Instabilidade de Microssatélites , Neoplasias/genética , Neoplasias/terapia , Prognóstico , Triptofano/genética , Triptofano/metabolismo , Triptofano Oxigenase/genética , Triptofano Oxigenase/metabolismo
18.
RSC Adv ; 12(38): 24778-24785, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36128401

RESUMO

A novel fluorescent probe based on molecularly imprinted polymers (MIPs) coupled with N-doped carbon dots (CDs) was prepared and used for specific recognition and sensitive determination of tetracycline (TC). N-doped CDs were synthesized using citric acid as a carbon source and ethylenediamine as a nitrogen source by a microwave assisted pyrolysis method. The determination conditions such as the solvents, material amount, pH value, and temperature were optimized. The CDs-MIPs have the best quenching on TC in water. The proposed method used for TC determination in milk powder samples had a detection limit of 0.054 µg mL-1 and a wide range of 0.5-30 µg mL-1. Meanwhile, satisfactory recoveries were obtained ranging from 95 to 108%. Oxytetracycline, chlorotetracycline and most of the coexisting substances showed no obvious interference indicating that the CDs-MIP probe exhibited high selectivity due to the presence of imprinted sites. Charge transfer from CDs-MIPs to TC may be through the mechanism of fluorescence quenching. This work gives a feasible strategy for the synthesis of N-doped carbon dot based molecularly imprinted polymers used as a fluorescent sensor in the food analysis field.

19.
RSC Adv ; 12(33): 21022-21025, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35919833

RESUMO

An efficient metal-free, (NH4)2S2O8 mediated oxidative dearomatization of indoles for the construction of C2-quaternary indolinones was disclosed. A series of C2-quaternary indolinones derivatives with good functional group tolerance were obtained in moderate to excellent yields. This methodology provides an alternative approach for the direct generation of all-carbon quaternary centers at the C2 position of indoles. This catalytic approach represents a step-economic and convenient strategy for the oxidative dearomatization of indoles.

20.
Genome Res ; 2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-35948368

RESUMO

Understanding the genetic mechanisms of phenotypic variation in hybrids between domestic animals and their wild relatives may aid germplasm innovation. Here, we report the high-quality genome assemblies of a male Pamir argali (O ammon polii, 2n = 56), a female Tibetan sheep (O aries, 2n = 54), and a male hybrid of Pamir argali and domestic sheep, and the high-throughput sequencing of 425 ovine animals, including the hybrids of argali and domestic sheep. We detected genomic synteny between Chromosome 2 of sheep and two acrocentric chromosomes of argali. We revealed consistent satellite repeats around the chromosome breakpoints, which could have resulted in chromosome fusion. We observed many more hybrids with karyotype 2n = 54 than with 2n = 55, which could be explained by the selfish centromeres, the possible decreased rate of normal/balanced sperm, and the increased incidence of early pregnancy loss in the aneuploid ewes or rams. We identified genes and variants associated with important morphological and production traits (e.g., body weight, cannon circumference, hip height, and tail length) that show significant variations. We revealed a strong selective signature at the mutation (c.334C > A, p.G112W) in TBXT and confirmed its association with tail length among sheep populations of wide geographic and genetic origins. We produced an intercross population of 110 F2 offspring with varied number of vertebrae and validated the causal mutation by whole-genome association analysis. We verified its function using CRISPR-Cas9 genome editing. Our results provide insights into chromosomal speciation and phenotypic evolution and a foundation of genetic variants for the breeding of sheep and other animals.

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