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1.
Genomics ; 116(4): 110848, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38663523

RESUMO

Fiber quality is a major breeding goal in cotton, but phenotypically direct selection is often hindered. In this study, we identified fiber quality and yield related loci using GWAS based on 2.97 million SNPs obtained from 10.65× resequencing data of 1081 accessions. The results showed that 585 novel fiber loci, including two novel stable SNP peaks associated with fiber length on chromosomes At12 and Dt05 and one novel genome regions linked with fiber strength on chromosome Dt12 were identified. Furthermore, by means of gene expression analysis, GhM_A12G0090, GhM_D05G1692, GhM_D12G3135 were identified and GhM_D11G2208 function was identified in Arabidopsis. Additionally, 14 consistent and stable superior haplotypes were identified, and 25 accessions were detected as possessing these 14 superior haplotype in breeding. This study providing fundamental insight relevant to identification of genes associated with fiber quality and yield will enhance future efforts toward improvement of upland cotton.


Assuntos
Gossypium , Haplótipos , Melhoramento Vegetal , Polimorfismo de Nucleotídeo Único , Gossypium/genética , Genoma de Planta , Fibra de Algodão , Estudo de Associação Genômica Ampla , Locos de Características Quantitativas
2.
Phys Rev Lett ; 133(14): 146902, 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39423419

RESUMO

The shallow donor in zinc oxide (ZnO) is a promising semiconductor spin qubit with optical access. Single indium donors are isolated in a commercial ZnO substrate using plasma focused ion beam (PFIB) milling. Quantum emitters are identified optically by spatial and frequency filtering. The indium donor assignment is based on the optical bound exciton transition energy and magnetic dependence. The emission stability of these single donors in terms of both intensity and frequency, alongside their transition linewidths less than twice the lifetime limit, highlight the promise of single In donors as optically accessible spin qubits. The optical stability of single donors after FIB fabrication is promising for optical device integration required for scalable quantum technologies based on single donors in direct band gap semiconductors.

3.
Theor Appl Genet ; 137(2): 49, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38349579

RESUMO

KEY MESSAGE: A novel QTL on chromosome 2A for Fusarium crown rot resistance was identified and validated in wheat. Fusarium crown rot (FCR) is a fungal disease that causes significant yield losses in many cereal growing regions in the world. In this study, genetic analysis was conducted for a wheat EMS mutant C549 which showed stable resistance to FCR at seedling stage. A total of 10 QTL were detected on chromosomes 1A, 2A, 3B, 4A, 6B, and 7B using a population of 138 F7 recombinant inbred lines (RILs) derived from a cross between C549 and a Chinese germplasm 3642. A novel locus Qfcr.cau-2A, which accounted for up to 24.42% of the phenotypic variation with a LOD value of 12.78, was consistently detected across all six trials conducted. Furthermore, possible effects of heading date (HD) and plant height on FCR severity were also investigated in the mapping population. While plant height had no effects on FCR resistance, a weak and negative association between FCR resistance and HD was observed. A QTL for HD (Qhd.cau-2A.2) was coincident with Qfcr.cau-2A. Conditional QTL mapping indicated that although Qfcr.cau-2A and Qhd.cau-2A.2 had significant interactions, Qfcr.cau-2A remained significant after the effects of HD was removed. It is unlikely that genes underlying these two loci are same. Nevertheless, the stable expression of Qfcr.cau-2A in the validation population of 148 F7 RILs developed between C549 and its wild parent Chuannong 16 demonstrated the potential value of this locus in FCR resistance breeding programs.


Assuntos
Fusarium , Triticum/genética , Melhoramento Vegetal , Mapeamento Cromossômico , Cromossomos
4.
Arterioscler Thromb Vasc Biol ; 43(6): 910-926, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37078289

RESUMO

BACKGROUND: The benefits of exercise on the cardiovascular system are widely recognized; however, the underlying mechanisms are unknown. Here, we report the effect of the long noncoding RNA NEAT1 (nuclear paraspeckle assembly transcript 1), which is regulated by exercise, on atherosclerosis development after N6-methyladenosine (m6A) modifications. METHODS: Using clinical cohorts and NEAT1-/- mice, we determined the exercise-mediated expression and role of NEAT1 in atherosclerosis. To investigate the mechanism of epigenetic modification of NEAT1 regulated by exercise, we identified METTL14 (methyltransferase-like 14)-a key m6A modification enzyme under exercise-and found that METTL14 alters the expression and role of NEAT1 through m6A modification and elucidated the specific mechanism of METTL14 in vitro and in vivo. Finally, the NEAT1 downstream regulatory network was investigated. RESULTS: We found that NEAT1 expression was downregulated with exercise and that downregulation of NEAT1 was an important factor in the improvement of atherosclerosis with exercise. Exercise-mediated loss of function of NEAT1 can delay atherosclerosis. Mechanistically, we showed that exercise induced a significant downregulation of m6A modification and METTL14, which binds to the m6A sites of NEAT1 and promotes NEAT1 expression through subsequent YTHDC1 (YTH domain-containing 1) recognition to promote endothelial pyroptosis. Furthermore, NEAT1 induces endothelial pyroptosis by binding KLF4 (Kruppel-like factor 4) to promote the transcriptional activation of the key pyroptotic protein NLRP3 (NOD-like receptor thermal protein domain-associated protein 3), whereas exercise can attenuate NEAT1-mediated endothelial pyroptosis to improve atherosclerosis. CONCLUSIONS: Our study of NEAT1 provides new insights into the improvement of atherosclerosis by exercise. This finding demonstrates the role of exercise-mediated NEAT1 downregulation in atherosclerosis while expanding our understanding of the mechanisms by which exercise regulates long noncoding RNA function through epigenetic modifications.


Assuntos
Aterosclerose , RNA Longo não Codificante , Animais , Camundongos , Adenosina , Aterosclerose/genética , Aterosclerose/prevenção & controle , Piroptose , RNA Longo não Codificante/genética
5.
Anal Chem ; 95(4): 2436-2444, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36650048

RESUMO

Disinfection byproducts (DBPs), as an emerging water pollutant, present increasing concern and risk in public health and water safety. Due to their low concentration levels and inherent similarity in molecular structures, sensitive and accurate determination of DBPs is still a challenge especially for onsite or online detection. Herein, a self-regulated fluorescent probe based on the Ag nanoprism-modified lanthanide metal-organic framework (AgNPR@EuMOF) is designed for trichloroacetic acid (TCAA) detection. The EuMOF is constructed with Eu as the metal node and 5-boronoisophthalic acid as the ligand. By introducing sulfhydryl groups into EuMOF, AgNPR can be anchored on the EuMOF surface through Ag-S bonds, enabling the synthesis of stable AgNPR@EuMOF composites. During the sensing process, the triangle AgNPR will react with the organic halogen molecule, accomplished with the blue shift of surface plasmon resonance absorption peak and the significant change in the fluorescence of EuMOF. This probe can detect TCAA in a wide concentration range (0.1-40 µM) with high sensitivity and specificity. The density functional theory calculation on binding energies between DBPs and AgNPR suggests that TCAA has the largest interaction ability with AgNPR than other DBPs. Moreover, the detection of TCAA in real tap water and swimming pool water is also demonstrated with high accuracy. The reported AgNPR@EuMOF represents one of the pioneer fluorescence probes in DBP detection, which holds great promise for onsite or online analysis of trace DBPs in water.

6.
BMC Geriatr ; 23(1): 850, 2023 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-38093173

RESUMO

BACKGROUND: Quality of life (QoL) of older adults has become a pivotal concern of the public and health system. Previous studies found that both cognitive decline and neuropsychiatric symptoms (NPS) can affect QoL in older adults. However, it remains unclear how these symptoms are related to each other and impact on QoL. Our aim is to investigate the complex network relationship between cognitive and NPS symptoms in older adults, and to further explore their association with QoL. METHODS: A cross-sectional study was conducted in a sample of 389 older individuals with complaints of memory decline. The instruments included the Neuropsychiatric Inventory, the Mini Mental State Examination, and the 36-item Short Form Health Survey. Data was analyzed using network analysis and mediation analysis. RESULTS: We found that attention and agitation were the variables with the highest centrality in cognitive and NPS symptoms, respectively. In an exploratory mediation analysis, agitation was significantly associated with poor attention (ß = -0.214, P < 0.001) and reduced QoL (ß = -0.137, P = 0.005). The indirect effect of agitation on the QoL through attention was significant (95% confidence interval (CI) [-0.119, -0.035]). Furthermore, attention served as a mediator between agitation and QoL, accounting for 35.09% of the total effect. CONCLUSIONS: By elucidating the NPS-cognition-QoL relationship, the current study provides insights for developing rehabilitation programs among older adults to ensure their QoL.


Assuntos
Disfunção Cognitiva , Qualidade de Vida , Humanos , Idoso , Qualidade de Vida/psicologia , Estudos Transversais , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia , Cognição
7.
BMC Pulm Med ; 23(1): 357, 2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37740212

RESUMO

BACKGROUND: Glucocorticoids and Beta-2 receptor agonists are commonly used for the treatment of asthma in clinical practice, while these agents are accompanied by adverse reactions of different kinds. Studies have shown that acupuncture is effective in treating bronchial asthma. However, different acupuncture modalities have different costs and skill requirements, and there remains a lack of comparisons between different acupuncture modalities. This study aims to assess the efficacy of various acupuncture modalities in the treatment of asthma. METHODS: The following databases were searched for randomized controlled trials (RCTs) on acupuncture for the treatment of bronchial asthma from database inception to August 26, 2022: PubMed, Embase, The Cochrane Library, Web of Science, Chinese Journal Full-text Database (CNKI), Wanfang Database (Wanfang Date), VIP Database (VIP), China Biology Medicine disc (CBM). Stata 15.1 software was used to conduct network meta-analysis. The risk of bias in the included studies was evaluated using the Cochrane Risk of Bias Assessment Tool 2 (RoB2). RESULTS: A total of 8,693 relevant studies were found, and 30 RCTs were included, involving 2,722 patients with bronchial asthma and eight acupuncture modalities: manual acupuncture, moxibustion, electroacupuncture, ignipuncture, flying needle acupuncture, acupoint catgut embedding, acupoint application, and warm-needle moxibustion. The other 29 studies had certain risks, with the quality graded as "moderate". Among the pair-wise comparisons of statistical significance (p < 0.05), acupoint application was the most effective in improving pulmonary function (FEV1: Traditional medicine therapy-acupoint application [-7.29 (-12.11,-2.47)]; acupoint application-moxibustion [7.20 (0.28,14.11)]; FVC: acupoint application-Traditional medicine therapy [8.02 (2.54,13.50)]). Acupoint catgut embedding was the most effective in improving the ACT score of the patients (Traditional medicine therapy-acupoint catgut embedding [-4.29 (-7.94, -0.65)]; acupoint catgut embedding-moxibustion [5.52 (1.05,9.99)]). CONCLUSION: Acupoint application has evident merits in improving the clinical response rate and pulmonary function, while acupoint catgut embedding can improve other secondary indicators. For the clinical treatment of asthma, acupoint application can be selected as a complementary and alternative therapy, while the other acupuncture therapies can also be considered according to the examination results of the patients.


Assuntos
Terapia por Acupuntura , Asma , Humanos , Asma/terapia , Metanálise em Rede , Ensaios Clínicos Controlados Aleatórios como Assunto
8.
Nano Lett ; 22(5): 2134-2139, 2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35108020

RESUMO

Shallow donors in ZnO are promising candidates for photon-mediated quantum technologies. Utilizing the indium donor, we show that favorable donor-bound exciton optical and electron spin properties are retained in isolated ZnO nanowires. The inhomogeneous optical line width of single nanowires (60 GHz) is within a factor of 2 of bulk single-crystalline ZnO. Spin initialization via optical pumping is demonstrated and coherent population trapping is observed. The two-photon absorption width approaches the theoretical limit expected due to the hyperfine interaction between the indium nuclear spin and the donor-bound electron.

9.
Molecules ; 28(4)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36838627

RESUMO

The use of a coal-based energy structure generates a large amount of CO2 and NOx. The numerous emissions from these agents result in acid rain, photochemical smog, and haze. This environmental problem is considered one of the greatest challenges facing humankind in this century. Preheating combustion technology is considered an essential method for lowering the emissions of CO2 and NO. In this research, the char prepared from O2/CO2 and O2/H2O atmospheres was employed to reveal the effects of the addition of an oxidizing agent on the combustion characteristics of char. The structural features and combustion characteristics of preheated chars were determined by Raman, temperature-programmed desorption (TPD), and non-isothermal, thermo-gravimetric (TGA) experiments. According to the experimental results, the addition of oxidizing agents promoted the generation of smaller aromatic ring structures and oxygen-containing functional groups. The improvement in the surface physicochemical properties enhanced the reactivity of char and lowered its combustion activation energy. Furthermore, the combustion mechanisms of the char prepared from the O2/CO2 and O2/H2O atmospheres were investigated using the density functional theory (DFT). The simulation results illustrated that the combustion essence of char could be attributed to the migration of active atoms, the fracture of the benzene ring structure, and the reorganization of new systems. The addition of oxidizing agents weakened the conjugated components of the aromatic ring systems, promoting the successive decomposition of CO and NO. The results of this study can provide a theoretical basis for regulating the reaction atmosphere in the preheating process and promoting the development of clean combustion for high-rank coals.


Assuntos
Dióxido de Carbono , Oxigênio , Dióxido de Carbono/farmacologia , Oxigênio/química , Carvão Mineral , Atmosfera , Temperatura
10.
Entropy (Basel) ; 25(3)2023 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-36981419

RESUMO

Support vector machine (SVM) is a widely used and effective classifier. Its efficiency and accuracy mainly depend on the exceptional feature subset and optimal parameters. In this paper, a new feature selection method and an improved particle swarm optimization algorithm are proposed to improve the efficiency and the classification accuracy of the SVM. The new feature selection method, named Feature Selection-score (FS-score), performs well on data sets. If a feature makes the class external sparse and the class internal compact, its FS-score value will be larger and the probability of being selected will be greater. An improved particle swarm optimization model with dynamic adjustment of inertia weight (DWPSO-SVM) is also proposed to optimize the parameters of the SVM. By improving the calculation method of the inertia weight of the particle swarm optimization (PSO), inertia weight can decrease nonlinearly with the number of iterations increasing. In particular, the introduction of random function brings the inertia weight diversity in the later stage of the algorithm and the global searching ability of the algorithm to avoid falling into local extremum. The experiment is performed on the standard UCI data sets whose features are selected by the FS-score method. Experiments demonstrate that our algorithm achieves better classification performance compared with other state-of-the-art algorithms.

11.
Can J Infect Dis Med Microbiol ; 2023: 5516408, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37771844

RESUMO

Background: Malaria is a global public health concern, mainly occurring in sub-Saharan Africa. Children infected with malaria are more likely to develop severe disease, which can be fatal. During COVID-19 in 2020, diagnosing and treating malaria became difficult. We analyzed the clinical characteristics and laboratory indicators of children with severe malaria in Benin to provide important information for designing effective prevention and treatment strategies to manage pediatric cases. Methods: Clinical characteristics of pediatric patients with severe malaria admitted to two hospitals in Benin (Central Hospital of Lokossa and Regional Hospital of Natitingou, located ∼650 kilometers apart) were collected from January to December 2020. Patients were grouped according to age (group A: 4-12 months old, group B: 13-36 months old, and group C: 37-60 months old), and clinical and laboratory indicators were compared. The incidences of severe pediatric malaria in both hospitals in 2020 were calculated. Inclusion, exclusion, and blood transfusion criteria were identified. Results: We analyzed 236 pediatric cases. The main clinical symptoms among all patients were severe anemia, vomiting, prostration, poor appetite, dysphoria, and dyspnea. Over 50% of patients in group A experienced vomiting and severe anemia. Most patients in group B had severe anemia and prostration. Delirium affected significantly more patients in group C than in groups A and B. In group C, the hemoglobin and hematocrit levels were significantly higher (p < 0.05), and the leukocyte count was significantly lower (p < 0.01) than in groups A and B. Parasitemia was significantly higher in group C than in group A (p < 0.01). Twelve deaths occurred. Conclusions: Severe pediatric malaria is seasonal in Benin. The situation in children under 5 years old is poor. The main problems are severe disease conditions and high fatality rates. Effective approaches such as prevention and early and appropriate treatment are necessary to reduce the malaria burden in pediatric patients.

12.
Environ Sci Technol ; 56(12): 8854-8863, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35536552

RESUMO

Understanding the formation and inhibition of more toxic polychlorinated byproducts from the catalytic oxidation elimination of chlorinated volatile organic compounds (Cl-VOCs) and unveiling efficient strategies have been essential and challenging. Here, RuOx supported on CePO4-doped CeO2 nanosheets (Ru/Pi-CeO2) is designed for boosting catalytic oxidation for the removal of dichloromethane (DCM) as a representative Cl-VOC. The promoted acid strength/number and sintering resistance due to the doping of electron-rich and thermally stable CePO4 are observed along with the undescended redox ability and the exposed multi-active sites, which demonstrates a high activity and durability of DCM oxidation (4000 mg/m3 and 15,000 mL/g·h, stable complete-oxidation at 300 °C), exceptional versatility for different Cl-VOCs, alkanes, aromatics, N-containing VOCs, CO and their multicomponent VOCs, and enhanced thermal stability. The suppression of polychlorinated byproducts is determined over Ru/Pi-CeO2 and oxy-anionic S, V, Mo, Nb, or W doping CeO2, thus the oxy-anionic doping strategy is proposed based on the quenching of the electron-rich oxy-anions on chlorine radicals. Moreover, the simple mechanical mixing with these oxy-anionic salts is also workable even for other catalysts such as Co, Sn, Mn, and noble metal-based catalysts. This work offers further insights into the inhibition of polychlorinated byproducts and contributes to the convenient manufacture of monolithic catalysts with superior chlorine-poisoning resistance for the catalytic oxidation of Cl-VOCs.


Assuntos
Compostos Orgânicos Voláteis , Ânions , Catálise , Cloro , Oxirredução
13.
BMC Plant Biol ; 21(1): 53, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33478384

RESUMO

BACKGROUND: Pre-harvest sprouting (PHS) in wheat can cause severe damage to both grain yield and quality. Resistance to PHS is a quantitative trait controlled by many genes located across all 21 wheat chromosomes. The study targeted a large-effect quantitative trait locus (QTL) QPhs.ccsu-3A.1 for PHS resistance using several sets previously developed near-isogenic lines (NILs). Two pairs of NILs with highly significant phenotypic differences between the isolines were examined by RNA sequencing for their transcriptomic profiles on developing seeds at 15, 25 and 35 days after pollination (DAP) to identify candidate genes underlying the QTL and elucidate gene effects on PHS resistance. At each DAP, differentially expressed genes (DEGs) between the isolines were investigated. RESULTS: Gene ontology and KEGG pathway enrichment analyses of key DEGs suggested that six candidate genes underlie QPhs.ccsu-3A.1 responsible for PHS resistance in wheat. Candidate gene expression was further validated by quantitative RT-PCR. Within the targeted QTL interval, 16 genetic variants including five single nucleotide polymorphisms (SNPs) and 11 indels showed consistent polymorphism between resistant and susceptible isolines. CONCLUSIONS: The targeted QTL is confirmed to harbor core genes related to hormone signaling pathways that can be exploited as a key genomic region for marker-assisted selection. The candidate genes and SNP/indel markers detected in this study are valuable resources for understanding the mechanism of PHS resistance and for marker-assisted breeding of the trait in wheat.


Assuntos
Cromossomos de Plantas/genética , Regulação da Expressão Gênica de Plantas/genética , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Transcriptoma , Triticum/genética , Regulação para Baixo , Perfilação da Expressão Gênica , Marcadores Genéticos/genética , Germinação/genética , Melhoramento Vegetal , Reguladores de Crescimento de Plantas/metabolismo , Sementes/genética , Sementes/fisiologia , Transdução de Sinais , Triticum/fisiologia , Regulação para Cima
14.
Environ Sci Technol ; 55(6): 4007-4016, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33666414

RESUMO

Bulk metal doping and surface phosphate modification were synergically adopted in a rational design to upgrade the CeO2 catalyst, which is highly active but easily deactivated for the catalytic oxidation of chlorinated volatile organic compounds (Cl-VOCs). The metal doping increased the redox ability and defect sites of CeO2, which mostly promoted catalytic activity and inhibited the formation of dechlorinated byproducts but generated polychlorinated byproducts. The subsequent surface modification of the metal-doped CeO2 catalysts with nonmetallic phosphate completely suppressed the formation of polychlorinated byproducts and, more importantly, enhanced the stability of the surface structure by forming a chainmail layer. A highly active, durable, and selective catalyst of phosphate-functionalized RuOx-CeO2 was the most promising among all the metal-doped (Ru, Pd, Pt, Cr, Mn, Fe, Co, and Cu) CeO2 catalysts investigated owing to the prominent chemical stability of RuOx and its superior versatility in the catalytic oxidation of different kinds of Cl-VOCs and other typical pollutants, including dimethyl sulfide, CO, and C3H8. Moreover, the chemical stability of the catalyst, including its bulk and surface structural stability, was investigated by combining intensive treatment with HCl/H2O or HCl with subsequent ex situ ultraviolet-visible light Raman spectroscopy and confirmed the superior resistance to Cl poisoning of the phosphate-functionalized RuOx-CeO2. This work exemplifies a promising strategy for developing ideal catalysts for the removal of Cl-VOCs and provides a catalyst with the superior catalytic performance in Cl-VOC oxidation to date.


Assuntos
Fosfatos , Catálise , Oxirredução
15.
Environ Sci Technol ; 55(20): 14204-14214, 2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34623146

RESUMO

MnO2 nanorods with exposed (110), (100), or (310) facets were prepared and investigated for catalytic oxidation of chlorobenzene, then the (110)-exposed MnO2 nanorod was screened as the candidate parent and further modified by Pt and/or Mo with different contents. The loading of Pt enhanced activity and versatility of the pristine MnO2, but the polychlorinated byproducts and Cl2 were promoted, conversely, as the decoration of Mo inhibited the polychlorinated byproducts and improved durability. Determination of structure and properties suggested that Pt facilitated the formation of more oxygen vacancies/Mn3+ and surface adsorbed oxygen weakened the bonds of surface lattice oxygen, while Mo stabilized surface lattice oxygen and increased acid sites, especially Brønsted acid sites. Expectedly, Pt and Mo bifunctionally modified MnO2 presented a preferable activity, selectivity, and durability along with the super resistance to H2O, high-temperature, and HCl, and no prominent deactivation was observed within 30 h at 300 °C under dry and humid conditions, even at high-temperature aging at 600 °C and HCl-pretreatment (7 h). In this work, the optimized Mo and Pt codecorated MnO2 was considered a promising catalyst toward practical applications for catalytic oxidation of actual Cl-VOCs emissions.


Assuntos
Compostos de Manganês , Nanotubos , Catálise , Clorobenzenos , Óxidos
16.
J Sep Sci ; 43(13): 2610-2618, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32243078

RESUMO

A novel aptamer-modified magnetic mesoporous carbon was prepared to develop a specific and sensitive magnetic solid-phase extraction method through combination with ultra-high performance liquid chromatography-tandem mass spectrometry for the analysis chloramphenicol in complex samples. More specifically, the chloramphenicol aptamer-modified Mg/Al layered double hydroxide magnetic mesoporous carbon was employed as a novel magnetic solid-phase extraction sorbent for analyte enrichment and sample clean-up. The extraction solvent, extraction time, desorption solvent, and desorption time were investigated. It was found that the mesoporous structure and aptamer-based affinity interactions resulted in acceptable selective recognition and a good chemical stability toward trace amounts of chloramphenicol. Upon combination with the ultra-high performance liquid chromatography-tandem mass spectrometry technique, a specific and sensitive recognition method was developed with a low limit of detection (0.94 pmol/L, S/N = 3) for chloramphenicol analysis. The developed method was successfully employed for the determination of chloramphenicol in complex serum, milk powders, fish and chicken samples, giving recoveries of 87.0-107% with relative standard deviations of 3.1-9.7%.


Assuntos
Antibacterianos/análise , Aptâmeros de Nucleotídeos/química , Carbono/química , Cloranfenicol/análise , Fenômenos Magnéticos , Tamanho da Partícula , Porosidade , Propriedades de Superfície
17.
Molecules ; 25(4)2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32085411

RESUMO

In this study, a novel monolithic capillary column based on a NH2-MIL-53(Al) metal-organic framework (MOF) incorporated in poly (3-acrylamidophenylboronic acid/methacrylic acid-co-ethylene glycol dimethacrylate) (poly (AAPBA/MAA-co-EGDMA)) was prepared using an in situ polymerization method. The characteristics of the MOF-polymer monolithic column were investigated by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, Brunauer-Emmett-Teller analysis, and thermogravimetric analysis. The prepared MOF-polymer monolithic column showed good permeability, high extraction efficiency, chemical stability, and good reproducibility. The MOF-polymer monolithic column was used for in-tube solid-phase microextraction (SPME) to efficiently adsorb trace sulfonamides from food samples. A novel method combining MOF-polymer-monolithic-column-based SPME with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was successfully developed. The linear range was from 0.015 to 25.0 µg/L, with low limits of detection of 1.3-4.7 ng/L and relative standard deviations (RSDs) of < 6.1%. Eight trace sulfonamides in fish and chicken samples were determined, with recoveries of the eight analytes ranging from 85.7% to 113% and acceptable RSDs of < 7.3%. These results demonstrate that the novel MOF-polymer-monolithic-column-based SPME coupled with UHPLC-MS/MS is a highly sensitive, practical, and convenient method for monitoring trace sulfonamides in food samples previously extracted with an adequate solvent.


Assuntos
Análise de Alimentos , Polímeros/química , Microextração em Fase Sólida , Sulfonamidas/análise , Espectrometria de Massas em Tandem , Adsorção , Animais , Calibragem , Galinhas , Cromatografia Líquida de Alta Pressão , Peixes , Concentração de Íons de Hidrogênio , Estruturas Metalorgânicas , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Difração de Raios X
18.
BMC Plant Biol ; 19(1): 348, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399046

RESUMO

BACKGROUND: Resistance to pre-harvest sprouting (PHS) is one of the major objectives in wheat breeding programs. However, the complex quantitative nature of this trait presents challenges when breeding for PHS resistance. Characterization of PHS using near-isogenic lines (NILs) targeting major quantitative trait locus/loci (QTL/QTLs) can be an effective strategy for the identification of responsible genes and underlying mechanisms. RESULTS: In this study, multiple pairs of NILs were developed and confirmed for a major QTL located on the 4BL chromosome arm that contributes to PHS resistance in wheat, using a combined heterogeneous inbred family method and a fast generation cycling system. Phenotypic characterization of these confirmed NILs revealed significant differences in PHS resistance between the isolines, where the presence of the resistant allele increased the resistance to sprouting on spikes by 54.0-81.9% (average 70.8%) and reduced seed germination by 59.4-70.5% (average 66.2%). The 90 K SNP genotyping assay on the confirmed NIL pairs identified eight SNPs on 4BL, associated with five candidate genes; two of the candidate genes were related to seed dormancy. Agronomic traits in the NIL pairs were investigated; both plant height and grain number per spike were positively correlated with PHS susceptibility. CONCLUSIONS: This study confirmed multiple pairs of NILs and identified SNPs between PHS isolines, which are valuable resources for further fine-mapping of this locus to clone the major genes for PHS resistance and investigate the possible functional regulation of these genes on important agronomic traits, such as plant height and grain number per spike.


Assuntos
Triticum/genética , Cromossomos de Plantas , Genótipo , Fenótipo , Melhoramento Vegetal , Desenvolvimento Vegetal/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
19.
J Sep Sci ; 42(3): 716-724, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30548208

RESUMO

A facile and efficient strategy is developed to modify aptamers on the surface of the magnetic metal-organic framework MIL-101 for the rapid magnetic solid-phase extraction of ochratoxin A. To the best of our knowledge, this is the first attempt to create a robust aptamer-modified magnetic MIL-101 with covalent bonding for the magnetic separation and enrichment of ochratoxin A. The saturated adsorption of ochratoxin A by aptamer-modified magnetic MIL-101 was 7.9 times greater than that by magnetic metal-organic framework MIL-101 due to the former's high selective recognition as well as good stability. It could be used for extraction more than 12 times with no significant changes in the extraction efficiency. An aptamer-modified magnetic MIL-101-based method of magnetic solid-phase extraction combined with ultra high performance liquid chromatography with tandem mass spectrometry was developed for the determination of trace ochratoxin A with limit of detection of 0.067 ng/L. Ochratoxin A of 4.53-13.7 ng/kg was determined in corn and peanut samples. The recoveries were in the range 82.8-108% with a relative standard deviation (n = 5) of 4.5-6.5%. These results show that aptamer-modified magnetic MIL-101 exhibits selective and effective enrichment performance and have excellent potential for the analysis of ultra-trace targets from complex matrices.


Assuntos
Aptâmeros de Nucleotídeos/química , Contaminação de Alimentos/análise , Estruturas Metalorgânicas/química , Ocratoxinas/análise , Arachis/química , Fenômenos Magnéticos , Estruturas Metalorgânicas/síntese química , Zea mays/química
20.
J Therm Biol ; 83: 172-177, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31331516

RESUMO

Hibernators survive challenging winters by entering torpor, which lowers body temperature (Tb) to ∼5 °C for 12-14 days, followed by spontaneous arousals where Tb increases to ∼37 °C for 10-12 h before entering another torpor bout. This Tb cycle is accompanied by significant fluctuations in metabolic rate. Little is known about the role of the liver in lipid metabolism during hibernation. In this study we measured the effect of ambient temperature on liver volume and lipid content in 13-lined ground squirrels (Ictidomys tridecemlineatus). We housed animals at thermoneutral (25 °C) or cold (5 °C) ambient temperatures, with the same photoperiod (12 h light:12 h dark) for an entire year. We determined volume and water-fat ratio of the liver using magnetic resonance imaging (MRI). Ambient temperature significantly affected both liver volume and fat content. From October to August squirrels housed at 25 °C had 25% smaller livers compared to the squirrels housed at 5 °C, but their average lipid content (13.3%) was 37% higher. Because the squirrels housed at 25 °C appeared to continue feeding throughout the winter but did not enter extended torpor, more carbohydrates may have been diverted to lipid stores. By contrast, animals housed at 5 °C did not appear to feed, and carbohydrates would likely be preferentially stored in the liver as glycogen to supply glucose for brain metabolism. These results suggest that the fat burden caused by hibernators preparing for winter can lead to symptoms of metabolic syndrome, but that these symptoms are reversible in the spring.


Assuntos
Tecido Adiposo/anatomia & histologia , Hibernação , Fígado/anatomia & histologia , Sciuridae/fisiologia , Tecido Adiposo/metabolismo , Animais , Temperatura Baixa , Metabolismo dos Lipídeos , Fígado/metabolismo , Masculino , Tamanho do Órgão , Sciuridae/metabolismo
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