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1.
Arch Virol ; 169(3): 42, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38332318

RESUMO

Beauveria bassiana Vuillemin is an entomopathogenic fungus that has been developed as a biological insecticide. B. bassiana can be infected by single or multiple mycoviruses, most of which are double-stranded RNA (dsRNA) viruses, while infections with single-stranded RNA (ssRNA) viruses, especially negative single-stranded RNA (-ssRNA) viruses, have been observed less frequently. In the present study, we sequenced and analyzed the complete genomes of two new different mycoviruses coinfecting a single B. bassiana strain: a -ssRNA virus which we have named "Beauveria bassiana negative-strand RNA virus 1" (BbNSRV1), and a dsRNA virus, which we have named "Beauveria bassiana orthocurvulavirus 1" (BbOCuV1). The genome of BbNSRV1 consists of a single segment of negative-sense, single-stranded RNA with a length of 6169 nt, containing a single open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) with 1949 aa (220.1 kDa). BLASTx analysis showed that the RdRp had the highest sequence similarity (59.79%) to that of Plasmopara viticola lesion associated mononegaambi virus 2, a member of the family Mymonaviridae. This is the first report of a -ssRNA mycovirus infecting B. bassiana. The genome of BbOCuV1 consists of two dsRNA segments, 2164 bp and 1765 bp in length, respectively, with dsRNA1 encoding a protein with conserved RdRp motifs and 70.75% sequence identity to the putative RdRp of the taxonomically unassigned mycovirus Fusarium graminearum virus 5 (FgV5), and the dsRNA2 encoding a putative coat protein with sequence identity 64.26% to the corresponding protein of the FgV5. Phylogenetic analysis indicated that BbOCuV1 belongs to a taxonomically unassigned group of dsRNA mycoviruses related to members of the families Curvulaviridae and Partitiviridae. Hence, it might be the member of a new family that remains to be named and formally recognized.


Assuntos
Beauveria , Micovírus , Vírus de RNA , Vírus , Humanos , Beauveria/genética , RNA de Cadeia Dupla/genética , Filogenia , Genoma Viral , Vírus de RNA/genética , Vírus/genética , Vírus de RNA de Cadeia Dupla/genética , Micovírus/genética , RNA Polimerase Dependente de RNA/genética , RNA Viral/genética , Fases de Leitura Aberta
2.
Mol Plant Microbe Interact ; 36(5): 309-311, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36597013

RESUMO

To screen candidate fungal genes that may relate to avirulence genes corresponding to the host resistance genes, we characterized two field isolates of Magnaporthe oryzae that cause rice blast disease, especially in northeast China, and performed whole-genome resequencing of these two isolates. The genome assembly and annotation data was submitted to the National Center for Biotechnology Information database. Our study unveils the predicted fungal effectors of two dominant M. oryzae isolates in northeast China, providing a resource for Avr genes to clone. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Ascomicetos , Magnaporthe , Oryza , Magnaporthe/genética , Oryza/microbiologia , Genes Fúngicos/genética , Ascomicetos/genética
3.
Virol J ; 20(1): 255, 2023 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-37924080

RESUMO

BACKGROUND: The entomogenous fungus Beauveria bassiana is used as a biological insecticide worldwide, wild B. bassiana strains with high pathogenicity in the field play an important role in controlling insect pests via not only screening of highly virulent strains but also natural infection, but the pathogenicity degeneration of wild strains severely affected aforementioned effects. Previous studies have showed that multiple factors contributed to this phenomenon. It has been extensively proved that the mycovirus infection caused hypovirulence of phytopathogenic fungi, which has been used for plant disease biocontrol. However, it remains unknown whether the mycovirus epidemics is a key factor causing hypovirulence of B. bassiana naturally in the field. METHODS: Wild strains of B. bassiana were collected from different geographic locations in Jilin Province, China, to clarify the epidemic and diversity of the mycoviruses. A mycovirus Beauveria bassiana chrysovirus 2 (BbCV2) we have previously identified was employed to clarify its impact on the pathogenicity of host fungi B. bassiana against the larvae of insect pest Ostrinia furnacalis. The serological analysis was conducted by preparing polyclonal antibody against a BbCV2 coat protein, to determine whether it can dissociate outside the host fungal cells and subsequently infect new hosts. Transcriptome analysis was used to reveal the interactions between viruses and hosts. RESULTS: We surprisingly found that the mycovirus BbCV2 was prevalent in the field as a core virus in wild B. bassiana strains, without obvious genetic differentiation, this virus possessed efficient and stable horizontal and vertical transmission capabilities. The serological results showed that the virus could not only replicate within but also dissociate outside the host cells, and the purified virions could infect B. bassiana by co-incubation. The virus infection causes B. bassiana hypovirulence. Transcriptome analysis revealed decreased expression of genes related to insect epidermis penetration, hypha growth and toxin metabolism in B. bassiana caused by mycovirus infection. CONCLUSION: Beauveria bassiana infected by hypovirulence-associated mycovirus can spread the virus to new host strains after infecting insects, and cause the virus epidemics in the field. The findings confirmed that mycovirus infection may be an important factor affecting the pathogenicity degradation of B. bassiana in the field.


Assuntos
Beauveria , Micovírus , Animais , Virulência/genética , Micovírus/genética , Beauveria/genética , Perfilação da Expressão Gênica , Larva
4.
Molecules ; 28(13)2023 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-37446827

RESUMO

A rapid, precise, and dependable method for quantifying flavonoids in the fruiting bodies of Sanghuangporus was established using ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QQQ-MS/MS). Separation was achieved using a ZORBAX Eclipse Plus C18 column (1.8 µm, 3.0 mm × 100 mm) with a 15 min gradient of a mobile phase consisting of 0.01% aqueous formic acid and 2 mm/L ammonium formate (mobile phase A), and 0.01% formic acid and 2 mm/L ammonium formate in methanol (mobile phase B). A mass spectrometry analysis was performed using the multiple reaction monitoring (MRM) mode with an electrospray ion source. This method enabled the simultaneous detection of 10 flavonoids (sakuranetin, quercitrin, myricitrin, kaempferol, luteolin, rutin, hyperoside, kaempferol-3-O-rutinoside, catechin, and catechin gallate) in the fruiting bodies of Sanghuangporus. Additionally, we applied this method to analyze the flavonoid content in fruiting bodies of various Sanghuangporus species. The results revealed substantial variations in flavonoid content, up to a 100-fold difference, among different species, with myricitrin, hyperoside, and rutin identified as the most abundant flavonoids. This protocol serves as a valuable tool for quantifying flavonoid compounds in different Sanghuangporus species or under diverse cultivation conditions, particularly for identifying species with high levels of specific flavonoid compounds.


Assuntos
Flavonoides , Espectrometria de Massas em Tandem , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Flavonoides/química , Rutina , Carpóforos
5.
J Environ Manage ; 313: 114960, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35381528

RESUMO

China implemented the Promoting the Big and Quashing the Small Policy (PBQSP) in 2007 to alleviate air pollution due to coal-fired power plants (CFPPs). However, how the policy affected the air pollutant emissions remains poorly understood. We compared the air pollutant emissions between decommissioned and newly-built CFPPs under the PBQSP by developing a plant-level supply chain emission inventory model, taking Shandong, China's top provincial-level coal power producer, as the case area. The results indicated that compared to a 27.4% increase in electricity produced in Shandong from 2010 to 2014, the NOx, particulate matter (PM), Hg, and SO2 emissions disproportionately increased by 10.3%, 11.7%, 11.8% and 0.5%, respectively. It was found that the PBQSP policy has made great contribution to air pollution mitigation, as the supply chain emission intensities (emissions per kilowatt-hour) of NOX, PM, Hg and SO2 of the newly-built CFPPs are three-quarters, two-fifths, three-fifths, and four-fifths lower, respectively, than those of the decommissioned CFPPs. However, coal transport route changes caused an increase in NOX, PM, and SO2 emissions by 44.0%, 45.5%, and 55.6%, respectively, during the transportation stage, which offset the PBQSP overall mitigation effect. By building a comprehensive assessment framework for air pollutant control policies, our study provides insights for formulating coordinated mitigation measures for the pollutant-intensive industries, such as promoting efficient air pollutant control technologies including the spray dust suppression devices.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Ambientais , Mercúrio , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Poluição do Ar/prevenção & controle , China , Carvão Mineral/análise , Fontes de Energia Elétrica , Material Particulado/análise , Políticas , Centrais Elétricas
6.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 51(5): 552-562, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36581571

RESUMO

OBJECTIVE: To investigate the effect and mechanism of piceatannol on cerebral ischemia-reperfusion injury. METHODS: The oxygen-glucose deprivation reperfusion (OGD/R) model was constructed in primary cultured suckling rat cortical neuron cells. After 2 h of oxygen-glucose deprivation, the cells were treated with piceatannol for 24 h. The cell survival rate was detected by MTT assay, and the degree of cell damage was detected by intracellular lactate dehydrogenase (LDH) release assay. The activity of superoxide dismutase (SOD) and the content of adenosine triphosphate (ATP) were detected by colorimetric method. The content of reactive oxygen species (ROS) was detected by flow cytometry or observed with inverted fluorescence microscope. The ultrastructure of mitochondria was observed with transmission electron microscopy. Western blotting was used to detect the phosphorylation levels of protein kinase B (AKT) and glycogen synthase kinase (GSK)-3ß. Immunofluorescence staining was used to observe the nuclear localization of nuclear factor-erythroid 2-related factor (Nrf) 2. After OGD/R neuron cells were pretreated with Nrf2 inhibitor ML385 for 24 h, the effect of Nrf2 on the improvement of cell activity and antioxidant activity of piceatannol were investigated. Western blotting was used to detect the protein expression levels of Nrf2, heme oxygenase (HO) 1 and NADPH quinone oxidoreductase (NQO) 1. RESULTS: Piceatannol significantly increased the survival rate of OGD/R neurons, decreased LDH release and reactive oxygen species content, increased SOD activity, ameliorated mitochondrial ultrastructural damage, increased mitochondrial membrane potential and ATP level (all P<0.05), increased phosphorylation of AKT and GSK-3ß protein, up-regulated the expression of Nrf2, HO-1 and NQO1 protein, increased the nuclear-to-plasma ratio of Nrf2, and promoted the nuclear transfer of Nrf2 (all P<0.05). ML385 could significantly reverse the rescue effect of paclitaxel on the model cells and the regulatory activities of SOD, ROS and LDH (all P<0.05). CONCLUSION: Piceatannol can regulate Nrf2 by activating GSK-3ß signaling pathway, promote its nuclear translocation, exert corresponding antioxidant effect, and protect mitochondrial structure and function in rat neuron cells.


Assuntos
Oxigênio , Traumatismo por Reperfusão , Ratos , Animais , Oxigênio/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fator 2 Relacionado a NF-E2/farmacologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Glicogênio Sintase Quinase 3 beta/farmacologia , Glucose/metabolismo , Glucose/farmacologia , Transdução de Sinais , Neurônios , Superóxido Dismutase , Estresse Oxidativo
7.
Compr Psychiatry ; 97: 152154, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31884329

RESUMO

BACKGROUND: Internal migrant workers in the service industry are an important population in China, but the sleep quality of this population has not been well studied. The aims of the present study were to examine the prevalence of poor sleep quality among internal migrant workers in the service industry, explore the risk factors associated with poor sleep quality, and assess the correlation between insomnia and psychiatric factors. METHODS: We conducted a cross-sectional study in Shenzhen, a migrant city in China. The respondent-driven sampling (RDS) method was used to recruit participants. Sociodemographic data and physical and psychiatric health status were investigated using questionnaires. In total, 1756 internal migrant workers completed the questionnaires. The Chinese version of the Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality, the General Anxiety Disorder-7 (GAD-7) and Center for Epidemiologic Studies Depression (CES-D) scales were used to assess anxiety and depression, respectively. Mental resilience was assessed by the Chinese version of the Connor-Davidson Resilience Scale (CD-RISC). Regression analysis was used to identify the risk factors of poor sleep quality. A structural equation model (SEM) was used to analyze the relationships among sleep, anxiety, depression and resilience. RESULTS: The prevalence of poor sleep quality among internal migrant workers in the service industry was 25.4%. Multivariate regression analysis revealed that participants who were older (OR = 1.452), worked >8 h per day (OR = 1.553), had experienced physical illness in the past 2 weeks (OR = 3.631) and had psychiatric problems such as anxiety (OR = 1.695-3.331) and depression (OR = 1.437) had an increased risk of poor sleep quality (P < 0.05). Moreover, the risk of poor sleep quality increased as the severity of anxiety increased. We also detected sex-specific risk factors and depression associated with sleep quality in women (OR = 1.480, P < 0.05) but not in men. The SEM showed that sleep was mutually correlated with anxiety (r = 0.277, P < 0.001), depression (r = 0.301, P < 0.001), and resilience (r = -0.103, P < 0.001). Resilience was mutually correlated with anxiety (r = -0.179, P < 0.001) and depression (r = -0.222, P < 0.001). CONCLUSIONS: Our study indicated that poor sleep quality was common among internal migrant workers in the service industry. Older age, long working hours, and poor physical and psychiatric health status contributed to poor sleep quality. Compared to males, sleep quality in females was more likely to be impacted by depression. Optimum working hours and physical and psychological health are critical to improving sleep quality. Interventions for ameliorating sleep quality might have different priorities for males and females.


Assuntos
Ansiedade/epidemiologia , Povo Asiático/estatística & dados numéricos , Depressão/epidemiologia , Saúde Mental/estatística & dados numéricos , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Sono/fisiologia , Migrantes/psicologia , Adulto , Idoso , Ansiedade/psicologia , Transtornos de Ansiedade/epidemiologia , Povo Asiático/psicologia , China/epidemiologia , Estudos Transversais , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Vigilância da População , Prevalência , Fatores de Risco , Inquéritos e Questionários
8.
Alcohol Clin Exp Res ; 42(6): 1062-1072, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29672876

RESUMO

BACKGROUND: Widespread brain atrophy in alcohol-dependent individuals (ALC) has been consistently documented in pathological and magnetic resonance imaging (MRI) studies. Longitudinal MRI studies have shown that the regional brain volume losses in ALC are partially reversible during abstinence from alcohol. The goal of this study was to determine volume reductions in cortical and subcortical regions functionally important to substance use behavior and their changes during short-term (1 week to 1 month) and long-term abstinence (1 to 7 months) from alcohol. The regions of interest (ROIs) were as follows: anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), insula, amygdala, and hippocampus. METHODS: A total of 85 unique ALC were assessed at 1 week (n = 65), 1 month (n = 82), and 7 months (n = 36) of abstinence. In addition, 17 light/nondrinking healthy controls (CON) were assessed at baseline and follow-up over a 10-month interval. Regional brain volumes were derived from FreeSurfer. Cross-sectional statistical analyses using 1-way analysis of variance or Fisher's exact test were applied to identify group differences. Longitudinal statistical analyses using linear mixed models were applied to identify regional volume increases and nonlinear volume recovery trajectories. RESULTS: We demonstrated significant regional volume reductions in ACC, DLPFC, and hippocampus. Older age was associated with smaller DLPFC and OFC, and higher average monthly drinking over 1 year prior to study was associated with smaller OFC. We also demonstrated significant volume increases of all ROIs except amygdala in ALC and significant nonlinear volume recovery trajectories of DLPFC, OFC, and insula. CONCLUSIONS: Results showed significant volume reductions in key regions of the executive control, salience, and emotion networks in ALC at entry into treatment and significant volume increases during short-term and long-term abstinence that were nonlinear over the entire abstinence period for the DLPFC, OFC, and insula. This gray matter plasticity during alcohol abstinence may have important neurobiological and neurocognitive implications in ALC, and it may contribute to an individual's ability to maintain abstinence from alcohol at different phases.


Assuntos
Abstinência de Álcool/estatística & dados numéricos , Alcoolismo/patologia , Encéfalo/patologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Feminino , Substância Cinzenta/patologia , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Fatores de Tempo , Adulto Jovem
9.
Neuroradiology ; 59(7): 685-690, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28534135

RESUMO

PURPOSE: Familial cerebral cavernous malformation (CCM) patients present with multiple lesions that can grow both in number and size over time and are reliably detected on susceptibility-weighted imaging (SWI). Manual counting of lesions is arduous and subject to high variability. We aimed to develop an automated algorithm for counting CCM microbleeds (lesions <5 mm in diameter) on SWI images. METHODS: Fifty-seven familial CCM type-1 patients were included in this institutional review board-approved study. Baseline SWI (n = 57) and follow-up SWI (n = 17) were performed on a 3T Siemens MR scanner with lesions counted manually by the study neuroradiologist. We modified an algorithm for detecting radiation-induced microbleeds on SWI images in brain tumor patients, using a training set of 22 manually delineated CCM microbleeds from two random scans. Manual and automated counts were compared using linear regression with robust standard errors, intra-class correlation (ICC), and paired t tests. A validation analysis comparing the automated counting algorithm and a consensus read from two neuroradiologists was used to calculate sensitivity, the proportion of microbleeds correctly identified by the automated algorithm. RESULTS: Automated and manual microbleed counts were in strong agreement in both baseline (ICC = 0.95, p < 0.001) and longitudinal (ICC = 0.88, p < 0.001) analyses, with no significant difference between average counts (baseline p = 0.11, longitudinal p = 0.29). In the validation analysis, the algorithm correctly identified 662 of 1325 microbleeds (sensitivity=50%), again with strong agreement between approaches (ICC = 0.77, p < 0.001). CONCLUSION: The automated algorithm is a consistent method for counting microbleeds in familial CCM patients that can facilitate lesion quantification and tracking.


Assuntos
Hemorragia Cerebral/diagnóstico por imagem , Hemangioma Cavernoso do Sistema Nervoso Central/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
10.
Nucleic Acids Res ; 43(15): 7612-23, 2015 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-26150423

RESUMO

The mer operon confers bacterial resistance to inorganic mercury (Hg(2+)) and organomercurials by encoding proteins involved in sensing, transport and detoxification of these cytotoxic agents. Expression of the mer operon is under tight control by the dual-function transcriptional regulator MerR. The metal-free, apo MerR binds to the mer operator/promoter region as a repressor to block transcription initiation, but is converted into an activator upon Hg(2+)-binding. To understand how MerR interacts with Hg(2+) and how Hg(2+)-binding modulates MerR function, we report here the crystal structures of apo and Hg(2+)-bound MerR from Bacillus megaterium, corresponding respectively to the repressor and activator conformation of MerR. To our knowledge, the apo-MerR structure represents the first visualization of a MerR family member in its intact and inducer-free form. And the Hg(2+)-MerR structure offers the first view of a triligated Hg(2+)-thiolate center in a metalloprotein, confirming that MerR binds Hg(2+) via trigonal planar coordination geometry. Structural comparison revealed the conformational transition of MerR is coupled to the assembly/disassembly of a buried Hg(2+) binding site, thereby providing a structural basis for the Hg(2+)-mediated functional switching of MerR. The pronounced Hg(2+)-induced repositioning of the MerR DNA-binding domains suggests a plausible mechanism for the transcriptional regulation of the mer operon.


Assuntos
Proteínas de Bactérias/química , Proteínas de Ligação a DNA/química , Mercúrio/química , Proteínas Repressoras/química , Transativadores/química , Bacillus megaterium/genética , Sítios de Ligação , Modelos Moleculares , Óperon , Ligação Proteica , Conformação Proteica
11.
Plant Physiol ; 167(1): 11-24, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25371551

RESUMO

Marker-free transgenic plants can be developed through transposon-mediated transgene reintegration, which allows intact transgene insertion with defined boundaries and requires only a few primary transformants. In this study, we improved the selection strategy and validated that the maize (Zea mays) Activator/Dissociation (Ds) transposable element can be routinely used to generate marker-free transgenic plants. A Ds-based gene of interest was linked to green fluorescent protein in transfer DNA (T-DNA), and a green fluorescent protein-aided counterselection against T-DNA was used together with polymerase chain reaction (PCR)-based positive selection for the gene of interest to screen marker-free progeny. To test the efficacy of this strategy, we cloned the Bacillus thuringiensis (Bt) δ-endotoxin gene into the Ds elements and transformed transposon vectors into rice (Oryza sativa) cultivars via Agrobacterium tumefaciens. PCR assays of the transposon empty donor site exhibited transposition in somatic cells in 60.5% to 100% of the rice transformants. Marker-free (T-DNA-free) transgenic rice plants derived from unlinked germinal transposition were obtained from the T1 generation of 26.1% of the primary transformants. Individual marker-free transgenic rice lines were subjected to thermal asymmetric interlaced-PCR to determine Ds(Bt) reintegration positions, reverse transcription-PCR and enzyme-linked immunosorbent assay to detect Bt expression levels, and bioassays to confirm resistance against the striped stem borer Chilo suppressalis. Overall, we efficiently generated marker-free transgenic plants with optimized transgene insertion and expression. The transposon-mediated marker-free platform established in this study can be used in rice and possibly in other important crops.


Assuntos
Elementos de DNA Transponíveis/genética , Oryza/genética , Plantas Geneticamente Modificadas/genética , Animais , Bacillus thuringiensis/genética , DNA Bacteriano/genética , DNA de Plantas/genética , Resistência à Doença/genética , Marcadores Genéticos/genética , Vetores Genéticos/genética , Proteínas de Fluorescência Verde/genética , Lepidópteros , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transformação Genética/genética , Transgenes/genética
13.
Acta Crystallogr D Biol Crystallogr ; 70(Pt 6): 1549-60, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24914966

RESUMO

In biological systems, methylation is most commonly performed by methyltransferases (MTs) using the electrophilic methyl source S-adenosyl-L-methionine (SAM) via the S(N)2 mechanism. (2S,3S)-ß-Methylphenylalanine, a nonproteinogenic amino acid, is a building unit of the glycopeptide antibiotic mannopeptimycin. The gene product of mppJ from the mannopeptimycin-biosynthetic gene cluster is the MT that methylates the benzylic C atom of phenylpyruvate (Ppy) to give ßMePpy. Although the benzylic C atom of Ppy is acidic, how its nucleophilicity is further enhanced to become an acceptor for C-methylation has not conclusively been determined. Here, a structural approach is used to address the mechanism of MppJ and to engineer it for new functions. The purified MppJ displays a turquoise colour, implying the presence of a metal ion. The crystal structures reveal MppJ to be the first ferric ion SAM-dependent MT. An additional four structures of binary and ternary complexes illustrate the molecular mechanism for the metal ion-dependent methyltransfer reaction. Overall, MppJ has a nonhaem iron centre that bind, orients and activates the α-ketoacid substrate and has developed a sandwiched bi-water device to avoid the formation of the unwanted reactive oxo-iron(IV) species during the C-methylation reaction. This discovery further prompted the conversion of the MT into a structurally/functionally unrelated new enzyme. Through stepwise mutagenesis and manipulation of coordination chemistry, MppJ was engineered to perform both Lewis acid-assisted hydration and/or O-methyltransfer reactions to give stereospecific new compounds. This process was validated by six crystal structures. The results reported in this study will facilitate the development and design of new biocatalysts for difficult-to-synthesize biochemicals.


Assuntos
Ferro/química , Metiltransferases/química , Cristalografia por Raios X , Modelos Moleculares , Conformação Proteica , Engenharia de Proteínas , Streptomyces/enzimologia
14.
Magn Reson Med ; 71(6): 2155-65, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23900962

RESUMO

PURPOSE: A novel longitudinal relaxation time (T1 ) measurement method using complex amplitude modulation is presented. THEORY: The method applies a series of inversion pulses to the imaged region in accordance with a binary modulation sequence. The longitudinal magnetization acquired in a given pulse repetition time (TR) interval is the sum of the individual longitudinal magnetization recovered during each previous TR interval, weighted by T1 decay factors and the combined effect of all the radiofrequency pulses they have experienced. The demodulated signal for each voxel is an exponential curve with a decaying rate determined by T1 and the acquisition flip angle θ. METHODS: Sequences using a 15-cycle pseudorandom binary code were implemented on Siemens 3T Trio with standard gradient echo readout and multislice gradient echo-planar imaging. The sequences were tested on T1 phantoms and human and compared against inversion recovery method. RESULTS: Our studies on phantoms and a human volunteer show that T1 estimated from this method is very accurate and well reproducible. The average scan time is ∼1.6 s per slice (full k-space gradient echo-planar imaging with matrix size 128 × 128). CONCLUSION: The current protocol is almost twice as fast as two fastest existing methods. Optimizing protocols and incorporating common acceleration techniques will make it even faster.


Assuntos
Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Algoritmos , Mapeamento Encefálico/métodos , Imagem Ecoplanar , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imagens de Fantasmas , Reprodutibilidade dos Testes , Fatores de Tempo
15.
Magn Reson Med ; 69(3): 803-11, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22499027

RESUMO

Despite rigid-body realignment to compensate for head motion during an echo-planar imaging time-series scan, nonrigid image deformations remain due to changes in the effective shim within the brain as the head moves through the B(0) field. The current work presents a combined prospective/retrospective solution to reduce both rigid and nonrigid components of this motion-related image misalignment. Prospective rigid-body correction, where the scan-plane orientation is dynamically updated to track with the subject's head, is performed using an active marker setup. Retrospective distortion correction is then applied to unwarp the remaining nonrigid image deformations caused by motion-induced field changes. Distortion correction relative to a reference time-frame does not require any additional field mapping scans or models, but rather uses the phase information from the echo-planar imaging time-series itself. This combined method is applied to compensate echo-planar imaging scans of volunteers performing in-plane and through-plane head motions, resulting in increased image stability beyond what either prospective or retrospective rigid-body correction alone can achieve. The combined method is also assessed in a blood oxygen level dependent functional MRI task, resulting in improved Z-score statistics.


Assuntos
Algoritmos , Artefatos , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Imagem Ecoplanar/métodos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Humanos , Movimento (Física) , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Se Pu ; 41(1): 24-36, 2023 Jan.
Artigo em Zh | MEDLINE | ID: mdl-36633074

RESUMO

Thin layer chromatography (TLC) is a very useful liquid chromatography approach. The simple device, convenient operation, versatility, high throughput capabilities, low cost, and simple sample pretreatments make it widely employed in various fields. In recent years, TLC-MS has become one of the most prominent trends for this technology as developments of modern analytical technology and comprehensive application of different approaches. With the development and upgrading of medicine, food, and scientific instrument industries, it is believed that TLC-MS technology should play a better role and obtain an opportunity for development. This study reviewed TLC-MS interface technologies (most of which are in recent 10 years) based on more than 150 studies and classified these TLC-MS technologies as three strategies. The first is indirect coupling using commercially available interface instruments. The second is TLC-in-site detection directly with special MS ion source devices like fast-atom-bombardment desorption ionization, matrix-assisted laser desorption ionization, surface-assisted laser desorption ionization, electrospray-assisted laser desorption ionization, laser-induced acoustic desorption/electrospray ionization, electrostatic-spray ionization, easy ambient sonic-spray ionization, desorption sonic spray ionization, ionization using "desorption/ionization resource", ionization using "molecular ionization-desorption analysis source", multiwavelength laser desorption ionization, ionization using flowing afterglow-atmospheric pressure glow discharge, ionization low-temperature plasma probe, desorption/ionization induced using neutral clusters, ionization using inductively coupled plasma and so on. These MS analyses are performed after TLC development, thus, the relative position of the chromatographic bands on TLCs is invariable, and this analysis can be regarded as static detection, though flexible travel stages or conveyor belts can be introduced to move TLC plates. The third strategy is to monitor TLC run using MS in real-time just as the monitor employed in HPLC, in which the chromatographic bands are still moving. This strategy is generally run on forced-flow TLC techniques and is less examined. The typical coupling technologies (especially appeared in recent ten years) are summarized and briefly described in this study. TLC-MS has greatly enhanced the research efficiency of bioactive substances for food and drugs due to the widespread usage of TLC-bioautography technology. Nowadays, the main bottleneck in the development of TLC-MS is the design and commercialization of "plug and play" components. The high-throughput and real-time monitoring TLC-MS technology with flexible scanning functions is also expected. Furthermore, the comparative studies of different kinds of desorbing-ionizing technologies are also application problems for further discussion.


Assuntos
Compostos Orgânicos , Cromatografia em Camada Fina , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Cromatografia Líquida de Alta Pressão
17.
Plants (Basel) ; 12(20)2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37896027

RESUMO

Sanghuangporus, a medicinal mushroom, has gained significant attention due to its beneficial properties. Phenolic acids are among the major bioactive compounds in Sanghuangporus, known for their antioxidant and anti-inflammatory activities. To precisely quantify the phenolic acid content, we developed a method utilizing ultra-high-performance liquid chromatography with triple quadrupole (UHPLC-QqQ). This study optimized the UHPLC-QqQ conditions to simultaneously separate and detect eight phenolic acids in Sanghuangporus baumii (Pilát) L.W. Zhou and Y.C. Dai, including chlorogenic acid, p-coumaric acid, caffeic acid, cryptochlorogenic acid, protocatechuic acid, ferulic acid, sinapic acid, and syringic acid. The separation process utilized a ZORBAX Eclipse Plus C18 column using 0.01% formic acid and 2 mmol/L ammonium formate in water as the aqueous phase and methanol containing 0.01% formic acid and 2 mmol/L ammonium formate as the organic phase. Calibration curves were constructed using standard solutions to quantitatively determine the phenolic acid content. The results showed significant variation in phenolic acid content among S. baumii fruiting bodies, with Protocatechuic acid, p-coumaric acid, and caffeic acid being the most abundant. This method is valuable for quantifying phenolic acid compounds under different cultivation conditions. It provides excellent sensitivity, selectivity, and reproducibility for the quantification of phenolic acids in Sanghuangporus, contributing to a better understanding of its chemical composition and potential health benefits. This approach represents a novel technical means for the simultaneous analysis of compound phenolic acids in Sanghuangporus fruiting bodies.

18.
J Orthop Surg Res ; 18(1): 838, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37932742

RESUMO

BACKGROUND: Spinal cord ischemia-reperfusion injury (SCII) is a catastrophic event, which can cause paraplegia in severe cases. In the reperfusion stage, oxidative stress was up-regulated, which aggravated the injury and apoptosis of neurons. As the main active ingredient of garlic, diallyl trisulfide (DATS) displays strong antioxidant capacity. However, it is unknown whether DATS can protect the neurons of SCII. MATERIALS AND METHODS: In this study, the descending aorta at the distal end of the left subclavian artery was ligated and perfused again after 14 min. Samples including blood and spinal cord (L2-L5) were taken 24 h later for morphological and biochemical examination. RESULTS: After SCII, the rats showed motor dysfunction, increase apoptosis, malondialdehyde content, mitochondrial biogenesis and dynamic balance disorder. After the application of DATS, the adenosine monophosphate activated protein kinase (AMPK) was activated, the mitochondrial damage was improved, the oxidative stress was weakened, and the neuronal damage was recovered to some extent. However, the addition of compound C significantly weakened the protective effect of DATS. CONCLUSION: Oxidative stress caused by mitochondrial damage was one of the important mechanisms of neuronal damage in SCII. DATS could activate AMPK, stabilize mitochondrial biogenesis and dynamic balance, and reduce neuronal damage caused by oxidative stress.


Assuntos
Proteínas Quinases Ativadas por AMP , Traumatismo por Reperfusão , Ratos , Animais , Proteínas Quinases Ativadas por AMP/metabolismo , Estresse Oxidativo , Traumatismo por Reperfusão/metabolismo , Antioxidantes/farmacologia , Medula Espinal , Apoptose , Mitocôndrias/metabolismo
19.
Nat Commun ; 14(1): 3144, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37253805

RESUMO

The low-carbon power transition, which is key to combatting climate change, has far-reaching effects on achieving the Sustainable Development Goals (SDGs) in terms of issues such as resource use, environmental emissions, employment, and many more. Here, we assess the potential impacts of the power transition on progress toward achieving multiple SDGs (covering 18 targets across the 17 goals) across 49 economies under nine socioeconomic and climate scenarios. We find that the low-carbon power transition under the representative concentration pathway (RCP)2.6 scenarios could lead to an approximately 11% improvement in the global SDG index score from 54.70 in 2015 to 59.89-61.33 in 2100. However, the improvement would be significantly decreased to 4.42%-7.40% and 7.55%-8.93% under the RCP6.0 and RCP4.5 scenarios, respectively. The power transition could improve the overall SDG index in most developed economies under all scenarios while undermining their resource-related SDG scores. Power transition-induced changes in international trade would improve the SDG progress of developed economies but jeopardize that of developing economies, which usually serve as resource hubs for meeting the demand for low-carbon power transition in developed economies.

20.
Comput Intell Neurosci ; 2022: 7543957, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35814544

RESUMO

The Chinese sports industry encompasses both the secondary and tertiary sectors of the country's economy. More prominent are the issues of unbalanced industrial structure development, mismatch between supply and demand, and rapid expansion of the sports goods manufacturing industry. This paper first employs the literature method to investigate the dynamic mechanism and promotion strategy of China's sports industry's green development. In order to improve the accuracy of data mining and quantitative analysis in the sports industry, this paper proposes a time series-based model for the analysis of sports industry data. Utilizing the global steady-state feature fusion method, the statistical and quantitative fusion analysis method, and the fuzzy analytical control method, accurate mining of sports industry data is achieved. The simulation results demonstrate that this method has greater precision and a higher degree of feature matching for sports industry data mining, thereby reducing the disturbance error of sports industry data mining.


Assuntos
Indústrias , Esportes , China , Mineração de Dados , Indústria Manufatureira
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