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1.
Phytopathology ; 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39190815

RESUMO

Bacillus velezensis YL2021 has extensive antimicrobial activities against phytopathogens, and its genome harbors a catechol-type siderophore biosynthesis gene cluster. Here, we describe the characterization of siderophore produced by strain YL2021 and its antimicrobial activity in vitro and in vivo. A few types of siderophores were detected by chrome azurol S plates coupled with Arnow's test, purified and identified by Reversed-phase high-performance liquid chromatography (RP-HPLC). We found that strain YL2021 can produce different antimicrobial compounds under low-iron M9 medium or iron-sufficient LB medium although antimicrobial activities can be easily observed on the two media as described above in vitro. Strain YL2021 can produce at least three catechol-type siderophores in low-iron M9 medium while no siderophore was produced in LB medium. Among them, the main antimicrobial siderophore produced by strain YL2021 was bacillibactin, with m/z of 882, based on the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, which has broad-spectrum antimicrobial activities against Gram-positive, Gram-negative bacteria, the oomycete Phytophthora capsici and phytopathogenic fungi. Moreover, the antifungal activity of siderophore including bacillibactin observed in vitro was correlated with control efficacies against rice sheath blight disease caused by Rhizoctonia solani and rice blast disease caused by Magnaporthe oryzae in vivo. Collectively, the results demonstrate that siderophore including bacillibactin produced by Bacillus velezensis YL2021 is a promising biocontrol agent for application in rice disease control.

2.
Sensors (Basel) ; 23(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37050726

RESUMO

Railway switches and crossings (S&C) are among the most important high-value components in a railway network and a failure of such an asset could result in severe network disturbance. Therefore, potential defects need to be detected at an early stage to prevent traffic-disturbing downtime or even severe accidents. A squat is a common defect of S&Cs that has to be monitored and repaired to reduce such risks. In this study, a testbed including a full-scale S&C and a bogie wagon was developed. Vibrations were measured for different squat sizes by an accelerometer mounted at the point machine. A method of processing the vibration data and the speed data is proposed to investigate the possibility of detecting and quantifying the severity of a squat. One key technology used is wavelet denoising. The study shows that it is possible to monitor the development of the squat size on the rail up to around 13 m from the point machine. The relationships between the normalised peak-to-peak amplitude of the vibration signal and the squat depth were also estimated.

3.
Opt Lett ; 47(12): 3087-3090, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35709057

RESUMO

An in-house dual-modality x-ray fluorescence tomography (XFT) and x-ray computed tomography (XCT) system was developed to quantify iodine contrast distribution through the whole tumor volume ex vivo. The quantitative XFT was calibrated with water phantoms containing iodine solutions of various concentrations (0.0175-1.4 wt.%). The vasculature distribution was reflected by the iodine perfusion, which was validated with histology. This technique may open a new, to the best of our knowledge, route to the non-destructive three-dimensional-imaging-based histological analysis of tumor samples.


Assuntos
Iodo , Neoplasias , Humanos , Neoplasias/diagnóstico por imagem , Imagem Óptica , Imagens de Fantasmas , Tomografia Computadorizada por Raios X/métodos , Raios X
4.
J Appl Clin Med Phys ; 23(11): e13775, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36168935

RESUMO

PURPOSE: The purpose of this work is to develop and evaluate a novel cycle-contrastive unpaired translation network (cycleCUT) for synthetic computed tomography (sCT) generation from T1-weighted magnetic resonance images (MRI). METHODS: The cycleCUT proposed in this work integrated the contrastive learning module from contrastive unpaired translation network (CUT) into the cycle-consistent generative adversarial network (cycleGAN) framework to effectively achieve unsupervised CT synthesis from MRI. The diagnostic MRI and radiotherapy planning CT images of 24 brain cancer patients were obtained and reshuffled to train the network. For comparison, the traditional cycleGAN and CUT were also implemented. The sCT images were then imported into a treatment planning system to verify their feasibility for radiotherapy planning. The mean absolute error (MAE), peak signal-to-noise ratio (PSNR), and structural similarity index (SSIM) between the sCT and the corresponding real CT images were calculated. Gamma analysis between sCT- and CT-based dose distributions was also conducted. RESULTS: Quantitative evaluation of an independent test set of six patients showed that the average MAE was 69.62 ± 5.68 Hounsfield Units (HU) for the proposed cycleCUT, significantly (p-value < 0.05) lower than that for cycleGAN (77.02 ± 6.00 HU) and CUT (78.05 ± 8.29). The average PSNR was 28.73 ± 0.46 decibels (dB) for cycleCUT, significantly larger than that for cycleGAN (27.96 ± 0.49 dB) and CUT (27.95 ± 0.69 dB). The average SSIM for cycleCUT (0.918 ± 0.012) was also significantly higher than that for cycleGAN (0.906 ± 0.012) and CUT (0.903 ± 0.015). Regarding gamma analysis, cycleCUT achieved the highest passing rate (97.95 ± 1.24% at the 2%/2 mm criteria and 10% dose threshold) but was not significantly different from the others. CONCLUSION: The proposed cycleCUT could be effectively trained using unaligned image data, and could generate better sCT images than cycleGAN and CUT in terms of HU number accuracy and fine structural details.


Assuntos
Neoplasias Encefálicas , Planejamento da Radioterapia Assistida por Computador , Humanos , Planejamento da Radioterapia Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos , Razão Sinal-Ruído , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia
5.
Sensors (Basel) ; 22(17)2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36080815

RESUMO

Railway switches and crossings (S&Cs) are critical, high-value assets in railway networks. A single failure of such an asset could result in severe network disturbance and considerable economical losses. Squats are common rail surface defects of S&Cs and need to be detected and estimated at an early stage to minimise maintenance costs and increase the reliability of S&Cs. For practicality, installation of wired or wireless sensors along the S&C may not be reliable due to the risk of damages of power and signal cables or sensors. To cope with these issues, this study presents a method for collecting and processing vibration data from an accelerometer installed at the point machine to extract features related to the squat defects of the S&C. An unsupervised anomaly-detection method using the isolation forest algorithm is applied to generate anomaly scores from the features. Important features are ranked and selected. This paper describes the procedure of parameter tuning and presents the achieved anomaly scores. The results show that the proposed method is effective and that the generated anomaly scores indicate the health status of an S&C regarding squat defects.


Assuntos
Ferrovias , Algoritmos , Florestas , Reprodutibilidade dos Testes , Vibração
6.
Clin Transplant ; 34(3): e13810, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32011059

RESUMO

This retrospective multicenter cohort study aimed to compare the outcome of haploidentical hematopoietic stem cell transplantation (HID-HSCT) with matched sibling donor (MSD) and unrelated donor (URD) transplantation in severe aplastic anemia (SAA) patients 40 years of age and older. With a median follow-up time of 17.6 months, 85 consecutive patients were enrolled in the study, and the median patient age was 45 years (40, 58). The cumulative engraftment rates of neutrophil and platelet were 98.8 ± 0.0% and 92.9 ± 0.1%. The cumulative incidences of Grade 2-4 acute graft-versus-host disease (aGvHD) and chronic graft-versus-host disease (cGvHD) at 3 years were 14.1 ± 0.1% and 17.3 ± 0.2%. The 3-year estimated overall survival (OS) and failure-free survival (FFS) were 91.2 ± 3.2% and 89.7 ± 3.5%. In multivariate analysis, the only factor associated with inferior survival was an ECOG score ≥2. HID-HSCT was associated with a higher incidence of GvHD, but the difference of 3-year estimated OS between HID group and the other two cohorts was not significant (86.7 ± 6.4% for HID vs 92.1% ± 4.4% for MSD and 100% for URD, P = .481). HID-HSCT might be a feasible alternative option for selected SAA patients aged 40 years and older without a matched donor.


Assuntos
Anemia Aplástica , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Adulto , Anemia Aplástica/terapia , Estudos de Coortes , Doença Enxerto-Hospedeiro/etiologia , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Condicionamento Pré-Transplante , Resultado do Tratamento , Doadores não Relacionados
7.
Tumour Biol ; 37(1): 151-62, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26577857

RESUMO

Observational studies have reported controversial results on the association between GSTT1 and GSTM1 genotypes and treatment outcome of breast cancer. The purpose of this study is to evaluate the association between GSTT1 and GSTM1 and treatment outcome in breast cancer patients. Eligible studies were searched in PubMed, EMBASE, Cochrane Library, and China National Knowledge Infrastructure databases. A random-effect model or fixed-effect model was used to calculate the overall combined risk estimates. Twenty-one studies with a total of 4990 patients were included in this meta-analysis. The GSTM1 null genotype (odds ratio (OR) = 1.33, 95 % confidence interval (CI) 1.01-1.75, P = 0.046) and GSTT1/GSTM1 double null genotype (OR = 2.22, 95 % CI 1.02-4.84, P = 0.045) were significantly associated with an increased tumor response. A reduced overall survival (hazard ratio (HR) = 0.84, 95 % CI 0.72-0.98, P = 0.024) was observed in GSTM1 null genotype, especially in mixed descent (HR = 0.77, 95 % CI 0.61-0.96, P = 0.018) and large sample size (HR = 0.85, 95 % CI 0.72-0.99, P = 0.033). Evidence of publication bias was observed in GSTM1 genotype rather than in GSTT1 genotype. This meta-analysis suggests that GSTM1 null and GSTT1/GSTM1 double null polymorphisms might be significantly associated with an increased tumor response. However, the GSTM1 null genotype might be significantly associated with a reduced overall survival. Future studies are warranted to confirm these findings.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Glutationa Transferase/genética , Polimorfismo Genético , Genótipo , Humanos , Razão de Chances , Prognóstico , Modelos de Riscos Proporcionais , Resultado do Tratamento
8.
BMC Plant Biol ; 14: 274, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25300176

RESUMO

BACKGROUND: Sesame (Sesamum indicum L., 2n = 26) is an important oilseed crop with an estimated genome size of 369 Mb. The genetic basis, including the number and locations of quantitative trait loci (QTLs) of sesame grain yield and quality remain poorly understood, due in part to the lack of reliable markers and genetic maps. Here we report on the construction of a hitherto most high-density genetic map of sesame using the restriction-site associated DNA sequencing (RAD-seq) combined with 89 PCR markers, and the identification of grain yield-related QTLs using a recombinant inbred line (RIL) population. RESULT: In total, 3,769 single-nucleotide polymorphism (SNP) markers were identified from RAD-seq, and 89 polymorphic PCR markers were identified including 44 expressed sequence tag-simple sequence repeats (EST-SSRs), 10 genomic-SSRs and 35 Insertion-Deletion markers (InDels). The final map included 1,230 markers distributed on 14 linkage groups (LGs) and was 844.46 cM in length with an average of 0.69 cM between adjacent markers. Using this map and RIL population, we detected 13 QTLs on 7 LGs and 17 QTLs on 10 LGs for seven grain yield-related traits by the multiple interval mapping (MIM) and the mixed linear composite interval mapping (MCIM), respectively. Three major QTLs had been identified using MIM with R2 > 10.0% or MCIM with ha 2 > 5.0%. Two co-localized QTL groups were identified that partially explained the correlations among five yield-related traits. CONCLUSION: Three thousand eight hundred and four pairs of new DNA markers including SNPs and InDels were developed by RAD-seq, and a so far most high-density genetic map was constructed based on these markers in combination with SSR markers. Several grain yield-related QTLs had been identified using this population and genetic map. We report here the first QTL mapping of yield-related traits with a high-density genetic map using a RIL population in sesame. Results of this study solidified the basis for studying important agricultural traits and implementing marker-assisted selection (MAS) toward genetic improvement in sesame.


Assuntos
Mapeamento Cromossômico/métodos , Grão Comestível/genética , Genoma de Planta/genética , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Sesamum/genética , Etiquetas de Sequências Expressas , Ligação Genética , Marcadores Genéticos/genética , Genômica , Genótipo , Repetições de Microssatélites/genética , Fenótipo , Análise de Sequência de DNA
9.
Eur Phys J E Soft Matter ; 37(7): 20, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25052065

RESUMO

In this paper the enthalpy relaxation of polystyrene (PS) was restudied using a structure-dependent Kohlrausch stretch exponent ß with incorporation of a coupling model (CM). The structure dependence of ß is described in 3 semi-phenomenological equations. The temperature and structure dependence of the relaxation time of the Johari-Goldstein (JG) relaxation (τ JG) is presented using the traditional Tools-Narayanaswamy-Moynihan (TNM) and Adam-Gibbs-Vogel (AGV) equations. The fitting results of heat capacity data are much better than the conventional TNM and Adam-Gibbs (AG) models when the structure dependence of ß is described using an exponential equation and τ JG is calculated using the AGV equation, although there are one fewer fitting parameters in the new model. The results indicate that both the structure dependence of ß and the CM model may play considerable roles in the investigation on the structure relaxation process in polymers around the glass transition.

10.
J Agric Food Chem ; 72(19): 10772-10780, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38703122

RESUMO

Protoporphyrinogen IX oxidase (PPO, E.C. 1.3.3.4) plays a pivotal role in chlorophyll biosynthesis in plants, making it a prime target for herbicide development. In this study, we conducted an investigation aimed at discovering PPO-inhibiting herbicides. Through this endeavor, we successfully identified a series of novel compounds based on the pyridazinone scaffold. Following structural optimization and biological assessment, compound 10ae, known as ethyl 3-((6-fluoro-5-(6-oxo-4-(trifluoromethyl)pyridazin-1(6H)-yl)benzo[d]thiazol-2-yl)thio)propanoate, emerged as a standout performer. It exhibited robust activity against Nicotiana tabacum PPO (NtPPO) with an inhibition constant (Ki) value of 0.0338 µM. Concurrently, we employed molecular simulations to obtain further insight into the binding mechanism with NtPPO. Additionally, another compound, namely, ethyl 2-((6-fluoro-5-(5-methyl-6-oxo-4-(trifluoromethyl)pyridazin-1(6H)-yl)benzo[d]thiazol-2-yl)thio)propanoate (10bh), demonstrated broad-spectrum and highly effective herbicidal properties against all six tested weeds (Leaf mustard, Chickweed, Chenopodium serotinum, Alopecurus aequalis, Poa annua, and Polypogon fugax) at the dosage of 150 g a.i./ha through postemergence application in a greenhouse. This work identified a novel lead compound (10bh) that showed good activity in vitro and excellent herbicidal activity in vivo and had promising prospects as a new PPO-inhibiting herbicide lead.


Assuntos
Desenho de Fármacos , Inibidores Enzimáticos , Herbicidas , Nicotiana , Proteínas de Plantas , Protoporfirinogênio Oxidase , Piridazinas , Protoporfirinogênio Oxidase/antagonistas & inibidores , Protoporfirinogênio Oxidase/metabolismo , Protoporfirinogênio Oxidase/química , Protoporfirinogênio Oxidase/genética , Piridazinas/química , Piridazinas/farmacologia , Herbicidas/farmacologia , Herbicidas/química , Herbicidas/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/síntese química , Relação Estrutura-Atividade , Nicotiana/metabolismo , Nicotiana/enzimologia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Simulação de Acoplamento Molecular , Estrutura Molecular , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Cinética
11.
Chem Commun (Camb) ; 60(23): 3162-3165, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38407303

RESUMO

Advancing catalyst design requires meticulous control of nanocatalyst selectivity at the atomic level. Here, we synthesized two Pd1Ag14 nanoclusters: Pd1Ag14(PPh3)8(SPh(CF3)2)6 and Pd1Ag14(P(Ph-p-OMe)3)7(SPh)6, each with well-defined structures. Notably, in Pd1Ag14(P(Ph-p-OMe)3)7(SPh)6, the detachment of a phosphine ligand from the top silver atom facilitates the exposure of singular active sites. This exposure significantly enhances its selectivity for the electrocatalytic reduction of CO2 to CO, achieving a Faraday efficiency of 83.3% at -1.3 V, markedly surpassing the 28.1% performance at -1.2 V of Pd1Ag14(PPh3)8(SPh(CF3)2)6. This work underscores the impact of atomic-level structural manipulation on enhancing nanocatalyst performance.

12.
Phys Med Biol ; 69(16)2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38996417

RESUMO

Objective.This study aims to address the issue of long scan durations required by traditional graphical analysis methods, such as the Logan plot and its variant, the reversible equilibrium (RE) Logan plot, for dynamic PET imaging of tracer kinetics.Approach.We propose a relative RE Logan model that builds on the principles of the Logan plot and its variant to significantly reduce scan time without compromising the accuracy of tracer kinetics analysis. The model is supported by theoretical evidence and experimental validations, including two computer simulations and one clinical data analysis.Main results.The proposed model demonstrates a significant linear relationship between the variablexand the slopeDVTof the RE Logan plot, and the variablex' and the slopeDVT'of the relative RE Logan plot. The Pearson correlation coefficients (r) of the linear fitting of thex' to thexequal 0.9849 in the simulated data and 0.9912 in the clinical data. Similarly, thervalues for the linear fitting ofDVT'toDVTequal 0.9989 and 0.9988 in the simulated data, and 0.9954 in the clinical data.Significance.These results demonstrate the model's capability to maintain strong linear relationships and produce parametric images comparable to the traditional RE Logan plot, but with the considerable advantage of shorter scan durations. This innovation holds significant potential for enhancing the efficiency and feasibility of PET imaging in clinical settings.


Assuntos
Tomografia por Emissão de Pósitrons , Tomografia por Emissão de Pósitrons/métodos , Humanos , Cinética , Traçadores Radioativos , Fatores de Tempo , Processamento de Imagem Assistida por Computador/métodos , Simulação por Computador
13.
Opt Express ; 21(9): 11294-308, 2013 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-23669986

RESUMO

Almost all the face recognition algorithms are unsatisfied due to illumination variation. Feature with high frequency represents the face intrinsic structure according to the common assumption that illumination varies slowly and the face intrinsic feature varies rapidly. In this paper, we will propose an adaptive scheme based on FBEEMD and detail feature fusion. FBEEMD is a fast version of BEEMD without time-consuming surface interpolation and iteration computation. It can decompose an image into sub-images with high frequency matching detail feature and sub-images with low frequency corresponding to contour feature. However, it is difficult to determine by quantitative analysis that which sub-images with high frequency can be used for reconstructing an illumination-invariant face. Thus, two measurements are proposed to calculate weights for quantifying the detail feature. With this fusion technique, one can reconstruct a more illumination-neutral facial image to improve face recognition rate. Verification experiments using classical recognition algorithms are tested with Yale B, PIE and FERET databases. The encouraging results show that the proposed scheme is very effective when dealing with face images under variable lighting condition.


Assuntos
Biometria/métodos , Face/anatomia & histologia , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Iluminação/métodos , Reconhecimento Automatizado de Padrão/métodos , Fotografação/métodos , Inteligência Artificial , Humanos
14.
Bioorg Med Chem ; 21(11): 3245-55, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23623257

RESUMO

Protoporphyrinogen oxidase (PPO, E.C. 1.3.3.4) is the action target for several structurally diverse herbicides. A series of novel 4-(difluoromethyl)-1-(6-halo-2-substituted-benzothiazol-5-yl)-3-methyl-1H-1,2,4-triazol-5(4H)-ones 2a-z were designed and synthesized via the ring-closure of two ortho-substituents. The in vitro bioassay results indicated that the 26 newly synthesized compounds exhibited good PPO inhibition effects with K(i) values ranging from 0.06 to 17.79 µM. Compound 2e, ethyl 2-{[5-(4-(difluoromethyl)-3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-6-fluorobenzo-thiazol-2-yl]thio}acetate, was the most potent inhibitor with K(i) value of 0.06 µM against mtPPO, comparable to (K(i)=0.03 µM) sulfentrazone. Further green house assays showed that compound 2f (K(i)=0.24 µM, mtPPO), ethyl 2-{[5-(4-(difluoromethyl)-3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-6-fluorobenzothiazol-2-yl]thio}propanoate, showed the most promising post-emergence herbicidal activity with broad spectrum even at concentrations as low as 37.5 gai/ha. Soybean exhibited tolerance to compound 2f at the dosages of 150 gai/ha, whereas they are susceptible to sulfentrazone even at 75 gai/ha. Thus, compound 2f might be a potential candidate as a new herbicide for soybean fields.


Assuntos
Herbicidas/síntese química , Proteínas de Plantas/antagonistas & inibidores , Protoporfirinogênio Oxidase/antagonistas & inibidores , Tiazóis/síntese química , Bioensaio , Herbicidas/química , Herbicidas/farmacologia , Simulação de Acoplamento Molecular , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Plantas Daninhas/crescimento & desenvolvimento , Protoporfirinogênio Oxidase/química , Protoporfirinogênio Oxidase/metabolismo , Glycine max/efeitos dos fármacos , Glycine max/enzimologia , Glycine max/crescimento & desenvolvimento , Especificidade da Espécie , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologia , Tiazóis/química , Tiazóis/farmacologia , Triazóis/química , Triazóis/farmacologia
15.
J Agric Food Chem ; 71(39): 14221-14231, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37729497

RESUMO

Protoporphyrinogen IX oxidase (PPO/Protox, E.C. 1.3.3.4) is recognized as one of the most important targets for herbicide discovery. In this study, we report our ongoing research efforts toward the discovery of novel PPO inhibitors. Specifically, we identified a highly potent new compound series containing a pyrimidinedione moiety and bearing a versatile building block-benzoxazinone scaffold. Systematic bioassays resulted in the discovery of compound 7af, ethyl 4-(7-fluoro-6-(3-methyl-2,6-dioxo-4-(trifluoromethyl)-3,6-dihydropyrimidin-1(2H)-yl)-3-oxo-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)butanoate, which exhibited broad-spectrum and excellent herbicidal activity at the dosage of 37.5 g a.i./ha through postemergence application. The inhibition constant (Ki) value of 7af to Nicotiana tabacum PPO (NtPPO) was 14 nM, while to human PPO (hPPO), it was 44.8 µM, indicating a selective factor of 3200, making it the most selective PPO inhibitor to date. Moreover, molecular simulations further demonstrated the selectivity and the binding mechanism of 7af to NtPPO and hPPO. This study not only identifies a candidate that showed excellent in vivo bioactivity and high safety toward humans but also provides a paradigm for discovering PPO inhibitors with improved performance through molecular simulation and structure-guided optimization.


Assuntos
Benzoxazinas , Herbicidas , Humanos , Benzoxazinas/farmacologia , Benzoxazinas/química , Protoporfirinogênio Oxidase , Inibidores Enzimáticos/química , Herbicidas/química , Nicotiana/metabolismo
16.
J Agric Food Chem ; 71(23): 8746-8756, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37261811

RESUMO

Protoporphyrinogen IX oxidase (PPO, E.C. 1.3.3.4), a key functional enzyme existing in various organisms, is acknowledged to be one of the most important action targets in the development of herbicides due to its pivotal roles in chlorophyll and heme biosynthesis pathways. As our persistent research work on the discovery of novel PPO-inhibiting herbicides, a new compound methyl 2-((5-(3-chloro-4,5,6,7-tetrahydro-2H-indazol-2-yl)-6-fluorobenzo[d]thiazol-2-yl)thio)acetate (8aj, Ki = 16 nM) was screened out as a hit compound via a fragment-based virtual screening method performed in the Auto Core Fragment in silico Screening web server. Subsequently, through a fused process of "hit-to-lead" optimization guided by molecular simulation, a total of 30 3-chloro-4,5,6,7-tetrahydro-2H-indazol-benzo[d]thiazole derivatives were synthesized and characterized. The results of the enzymatic inhibition bioassay showed that more than half of the newly synthesized compounds displayed higher activity against Nicotiana tabacum PPO (NtPPO) than oxadiazon, a commercial PPO-inhibiting herbicide. In particular, compound 8ab, a subnanomolar inhibitor with a Ki value of 380 pM against NtPPO, was discovered, which showed to be 71-fold more active than the commercial control oxadiazon (Ki = 27 nM), and was proven to be the most potent PPO inhibitor so far. Furthermore, the greenhouse assay demonstrated that most of the synthetic compounds showed good herbicidal activity toward the tested weeds. Especially, compound 8ad (Ki = 670 pM) showed the most promising post-emergence herbicidal activity with a broad spectrum of weed control even at a concentration as low as 37.5 g a.i./ha and relatively safe to rice at a dosage of 150 g a.i./ha, indicating that 8ad has the greatest potential to be developed as a new herbicide for weed control in paddy fields. This work provides a paradigm for the rational design and discovery of a novel PPO-inhibiting herbicide guided by the fragment-based drug design.


Assuntos
Inibidores Enzimáticos , Herbicidas , Protoporfirinogênio Oxidase , Inibidores Enzimáticos/farmacologia , Controle de Plantas Daninhas , Herbicidas/farmacologia , Plantas Daninhas , Nicotiana/metabolismo
17.
Bioorg Med Chem ; 20(1): 296-304, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22130420

RESUMO

Protoporphyrinogen oxidase (Protox, EC 1.3.3.4) has attracted great interest during the last decades due to its unique biochemical characteristics and biomedical significance. As a continuation of our research work on the development of new PPO inhibitors, 23 new 1,3,4-thiadiazol-2(3H)-ones bearing benzothiazole substructure were designed and synthesized. The in vitro assay indicated that the newly synthesized compounds 1a-w displayed good inhibition activity against human PPO (hPPO) with K(i) values ranging from 0.04µM to 245µM. To the knowledge, compound 1a, O-ethyl S-(5-(5-(tert-butyl)-2-oxo-1,3,4-thiadiazol-3(2H)-yl)-6-fluorobenzothiazol-2-yl)carbonothioate, with the K(i) value of 40nM, is so far known as the most potent inhibitor against hPPO. Based on the molecular docking and modified molecular mechanics/Poisson-Boltzmann surface area (MM-PBSA) calculations, the quantitative structure-activity relationships of 1,3,4-thiadiazol-2(3H)-ones and 1,3,4-oxadiazol-2(3H)-one derivatives were established with excellent correlation relationships (r(2)=0.81) between the calculated and experimental binding free energies. Some important insights were also concluded for guiding the future rational design of new hPPO inhibitors with improved potency.


Assuntos
Inibidores Enzimáticos/química , Oxidiazóis/química , Protoporfirinogênio Oxidase/antagonistas & inibidores , Tiadiazóis/química , Benzotiazóis/síntese química , Benzotiazóis/química , Benzotiazóis/farmacologia , Sítios de Ligação , Simulação por Computador , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Humanos , Conformação Molecular , Oxidiazóis/síntese química , Oxidiazóis/farmacologia , Estrutura Terciária de Proteína , Protoporfirinogênio Oxidase/metabolismo , Relação Quantitativa Estrutura-Atividade , Termodinâmica , Tiadiazóis/síntese química , Tiadiazóis/farmacologia
18.
Gynecol Endocrinol ; 28(8): 665-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22329840

RESUMO

OBJECTIVE: Uterine leiomyomas represents a major public health problem. Despite their prevalence, the causation and pathogenesis of leiomyomas are poorly understood. A broad range of organisms and tissues contain 14-3-3 proteins which have been associated with the pathogenesis of many diseases through participating in signal transduction pathways. This study was designed to evaluate which 14-3-3 isoforms might be optimal targets in leiomyomas, and to further explore their relationship with estrogen and progesterone receptor (ER and PR). METHODS: Paired samples of leiomyoma and adjacent myometrium were obtained from 80 subjects who had surgical excision of uterine leiomyomas. The expression of 14-3-3 isoforms was detected by Western bolt and RT-PCR, and their relationship with ER and PR was analysed by immunohistochemistry. RESULTS: The expressions of 14-3-3σ had decreased significantly in leiomyoma compared with that in normal myometrium and was negatively correlated with ER and PR by immunohistochemistry. CONCLUSION: The down-regulation of 14-3-3σ in leiomyoma suggests that 14-3-3σ may play a role in tumorigenesis, and that its mechanism may be involved in the up-regulation of ER and PR.


Assuntos
Proteínas 14-3-3/metabolismo , Biomarcadores Tumorais/metabolismo , Exonucleases/metabolismo , Regulação Neoplásica da Expressão Gênica , Leiomioma/metabolismo , Proteínas de Neoplasias/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Neoplasias Uterinas/metabolismo , Proteínas 14-3-3/genética , Adulto , Biomarcadores Tumorais/genética , Western Blotting , Regulação para Baixo , Exonucleases/genética , Exorribonucleases , Feminino , Humanos , Imuno-Histoquímica , Leiomioma/patologia , Leiomioma/cirurgia , Pessoa de Meia-Idade , Miométrio/metabolismo , Miométrio/patologia , Proteínas de Neoplasias/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para Cima , Neoplasias Uterinas/patologia , Neoplasias Uterinas/cirurgia
19.
Front Oncol ; 12: 868975, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35686106

RESUMO

Background: The objective of the current study was to investigate the diagnostic value of contrast-enhanced cone-beam breast computed tomography (CE-CBBCT) for breast lesion with rim enhancement (RE). Methods: All 36 patients were examined by non-contrast (NC-CBBCT) and contrast-enhanced CBBCT (CE-CBBCT) after contrast media (CM) injection. Qualitative morphological enhancement parameters and quantitative enhancement parameters were compared between malignant and benign groups. Multivariable logistic regression analysis was performed to identify independent factors that could predict breast lesion with RE malignancy. Receiver operating curve (ROC) was used to evaluate prediction performance. Results: A total of 36 patients with 40 lesions underwent breast CE-CBBCT were enrolled. There were significant differences in most qualitative morphological enhancement parameters between the two groups. A multivariate logistic regression model showed that △standardized HU (INRphase 2-INRpreCM) [odds ratio (OR) = 1.148, 95% CI = 1.034-1.276, p = 0.01] and △standardized HU (RPphase 2 - RPphase 1) (OR = 0.891, 95% CI = 0.814-0.976, p = 0.013) were independent indicators in predicting breast lesion with RE malignancy. △standardized HU (INRphase 2 - INRpreCM) combined with △standardized HU (RPphase 2 - RPphase 1) showed significant larger area under the receiver operating curve (AUC) and higher sensitivity than each alone (p < 0.001, AUC = 0.932, sensitivity = 92.59%, specificity = 92.31%). The regression equation of the prediction model was as follows: Logit (p) = 0.351 + 0.138X × â–³standardized HU (INRphase 2 - INRpreCM) - 0.115 × â–³standardized HU (RPphase 2 - RPphase 1). Conclusion: With the observation of qualitative morphological enhancement parameters and the comparison of quantitative enhancement parameters of CBBCT, a reliable basis for the diagnostic accuracy in predicting breast lesion with RE could be provided. These conclusions should be verified in large, well-designed studies.

20.
Microbiol Spectr ; 10(6): e0229722, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36287061

RESUMO

Antibiotic resistance genes (ARGs) pose a serious threat to public health and ecological security in the 21st century. However, the resistome only accounts for a tiny fraction of metagenomic content, which makes it difficult to investigate low-abundance ARGs in various environmental settings. Thus, a highly sensitive, accurate, and comprehensive method is needed to describe ARG profiles in complex metagenomic samples. In this study, we established a high-throughput sequencing method based on targeted amplification, which could simultaneously detect ARGs (n = 251), mobile genetic element genes (n = 8), and metal resistance genes (n = 19) in metagenomes. The performance of amplicon sequencing was compared with traditional metagenomic shotgun sequencing (MetaSeq). A total of 1421 primer pairs were designed, achieving extremely high coverage of target genes. The amplicon sequencing significantly improved the recovery of target ARGs (~9 × 104-fold), with higher sensitivity and diversity, less cost, and computation burden. Furthermore, targeted enrichment allows deep scanning of single nucleotide polymorphisms (SNPs), and elevated SNPs detection was shown in this study. We further performed this approach for 48 environmental samples (37 feces, 20 soils, and 7 sewage) and 16 clinical samples. All samples tested in this study showed high diversity and recovery of targeted genes. Our results demonstrated that the approach could be applied to various metagenomic samples and served as an efficient tool in the surveillance and evolution assessment of ARGs. Access to the resistome using the enrichment method validated in this study enabled the capture of low-abundance resistomes while being less costly and time-consuming, which can greatly advance our understanding of local and global resistome dynamics. IMPORTANCE ARGs, an increasing global threat to human health, can be transferred into health-related microorganisms in the environment by horizontal gene transfer, posing a serious threat to public health. Advancing profiling methods are needed for monitoring and predicting the potential risks of ARGs in metagenomes. Our study described a customized amplicon sequencing assay that could enable a high-throughput, targeted, in-depth analysis of ARGs and detect a low-abundance portion of resistomes. This method could serve as an efficient tool to assess the variation and evolution of specific ARGs in the clinical and natural environment.


Assuntos
Genes Bacterianos , Metagenoma , Humanos , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Esgotos , Metagenômica/métodos
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