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1.
J Plant Res ; 137(4): 605-617, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38506958

RESUMO

The intervention of nectar robbers in plant pollination systems will cause some pollinators to modify their foraging behavior to act as secondary robbers, consequently adopting a mixed foraging strategy. The influence of nectar robbing on pollinator behavior may be affected by spatio-temporal difference of robbing intensity, and consequently, may have different effects on the pollination of host plants. However, whether and how the nectar robbing might influence pollinators under different robbing intensity still needs further investigation. In this study, Symphytum officinale was used to detect the effect of nectar robbers on pollinators under different robbing intensity as well as their effects on plant reproductive success. Six robbing levels and three bumblebees with mixed foraging behaviors were used to evaluate the effect of different robbing intensity on pollinator behavior, visitation rate, flower longevity and pollen deposition. Our results indicated that the robbing rate increased gradually with the proportion of robbed flowers, but which did not affect the frequency of legitimate visits. The increase of robbing rate promoted the corolla abscission, and then enhanced the self-pollen deposition, but which had no significant effect on cross-pollen deposition. These results indicate that the overall fitness of S. officinale was improved by combined self and cross-pollination modes when visited by both pollinators and nectar robbers simultaneously. Although nectar robbing is not uncommon, its consequences for pollination in the interaction web have not been well studied. Our results emphasize the significance of indirect impacts in mediating the adaptive outcomes of species interactions.


Assuntos
Boraginaceae , Flores , Néctar de Plantas , Polinização , Reprodução , Polinização/fisiologia , Flores/fisiologia , Animais , Abelhas/fisiologia , Reprodução/fisiologia , Néctar de Plantas/fisiologia , Boraginaceae/fisiologia , Pólen/fisiologia
2.
Mov Disord ; 37(6): 1235-1244, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35285050

RESUMO

BACKGROUND: Cerebral blood flow (CBF) and dopamine transporter (DAT) images are clinically used for the differential diagnosis of parkinsonian disorders. OBJECTIVES: This study aimed to examine the correlation of CBF with striatal DAT in patients with Parkinson's disease (PD) and atypical parkinsonian syndromes (APS) and evaluate the diagnostic power of DAT-correlated CBF in PD through machine learning with each imaging modality alone or in combination. METHODS: Fifty-eight patients with PD and 71 with APS (24 with multiple system atrophy, 21 with progressive supranuclear palsy, and 26 with corticobasal syndrome) underwent 123 I-IMP and 123 I-FP-CIT single-photon emission computed tomography. Multiple regression analyses for CBF and striatal DAT binding were conducted on each group. PD probability was predicted by machine learning and receiver operating characteristic curves. RESULTS: The PD group showed more affected striatal DAT binding positively correlated with the ipsilateral prefrontal perfusion and negatively with the bilateral cerebellar perfusion. In corticobasal syndrome, striatal DAT binding positively correlated with the ipsilateral prefrontal perfusion and negatively with the contralateral precentral perfusion. In Richardson's syndrome, striatal DAT binding positively correlated with perfusion in the ipsilateral precentral cortex and basal ganglia. Machine learning showed that the combination of CBF and DAT was better for delineating PD from APS (area under the curve [AUC] = 0.87) than either CBF (0.67) or DAT (0.50) alone. CONCLUSIONS: In PD and four-repeat tauopathy, prefrontal perfusion was related to ipsilateral nigrostriatal dopaminergic function. This dual-tracer frontostriatal relationship may be effectively used as a diagnostic tool for delineating PD from APS. © 2022 International Parkinson and Movement Disorder Society.


Assuntos
Doença de Parkinson , Transtornos Parkinsonianos , Circulação Cerebrovascular , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Humanos , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/metabolismo , Transtornos Parkinsonianos/diagnóstico por imagem , Transtornos Parkinsonianos/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único/métodos
3.
J Wound Care ; 30(Sup12): S6-S12, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34882009

RESUMO

OBJECTIVE: Venous leg ulcers (VLUs) are considered the most frequent category of hard-to-heal limb ulcers. Although evidence-based care of VLUs suggests that compression therapy plays a pivotal role in the standard of care, patient adherence is considered low, with at least 33% non-compliance, either due to perceived problems from clinicians regarding their own competency in applying the bandages, or from the patient finding the wrapping bothersome. For many years, four-layer bandaging has been considered the 'gold standard', but application can be difficult and may also prove uncomfortable for patients. Accurate application may be facilitated by a stretch indicator which has been engineered to act as a surrogate for appropriate pressure application that can address the skill concern, while fewer layers can save clinicians' time and improve the quality of life of patients. Here, we review the literature supporting a two-layer system which combines elastic (long stretch) and inelastic (short stretch) components as well as both layers having graphic markers to define that the dressing has been applied at the proper tension. METHOD: An initial search was conducted on PubMed and then followed up by a manual search of Google Scholar to retrieve evidence of different levels, in order to evaluate the outcomes of use of the specific two-layer compression system with pressure indicators in the management of patients presenting with VLUs. RESULTS: A total of four papers discussing the specific compression system in question were identified from 32 publications retrieved from PubMed, while a further six were retrieved from Google Scholar. These 10 publications were considered relevant to the two-layer system and were analysed for the outcomes of care, including wound healing, appropriate application, time-saving and better patient acceptance and adherence. CONCLUSION: Previous authors have demonstrated that two-layer systems are equivalent to four-layer systems. However, the ability to reproducibly apply appropriate compression has remained a question. The papers reviewed demonstrate that evidence suggests that the two-layer compression bandage system with indicators provides continuous, consistent and comfortable treatment that may be easier to apply with accurate pressure levels due to their indicator systems, and therefore, is a procedure that may increase patient adherence and acceptability to the wound therapy.


Assuntos
Qualidade de Vida , Úlcera Varicosa , Bandagens Compressivas , Humanos , Cooperação do Paciente , Úlcera Varicosa/terapia , Cicatrização
4.
Angew Chem Int Ed Engl ; 56(22): 5994-6021, 2017 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-27805788

RESUMO

This Review addresses the technical challenges, scientific basis, recent progress, and outlook with respect to the stability and degradation of catalysts for the oxygen evolution reaction (OER) operating at electrolyzer anodes in acidic environments with an emphasis on ion exchange membrane applications. First, the term "catalyst stability" is clarified, as well as current performance targets, major catalyst degradation mechanisms, and their mitigation strategies. Suitable in situ experimental methods are then evaluated to give insight into catalyst degradation and possible pathways to tune OER catalyst stability. Finally, the importance of identifying universal figures of merit for stability is highlighted, leading to a comprehensive accelerated lifetime test that could yield comparable performance data across different laboratories and catalyst types. The aim of this Review is to help disseminate and stress the important relationships between structure, composition, and stability of OER catalysts under different operating conditions.

5.
Regul Toxicol Pharmacol ; 71(2): 205-12, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25558060

RESUMO

The lethal toxicity (LD50) in oral administration, intravenous, intraperitoneal, intramuscular and subcutaneous injections were used to investigate relationships of log 1/LD50 from different exposure routes. Regression analysis showed that log 1/LD50 in oral route was related to the toxicity in injection route. This relationship in lethality between the two routes is apparently due to the same mechanisms of the compounds to the same species. However, the scatter in the correlation curve indicates that exposure route is an important factor that influences the relationship. Some compounds with low intestinal absorption exhibit much less toxicity in oral administration than that in the injection route. A systemic bias of log 1/LD50 between oral and injection routes indicates that tissue distribution of compounds between blood and target site is a very rapid process, leading to log 1/LD50 in injection greater than those in oral administration. Although compounds can be metabolized in the body both from oral and injection routes, first-pass metabolism occurs in oral route but not in injection route. This will result in decrease of toxicity in oral route for most compounds as compared with injection route. In addition, experimental uncertainty, differences in gender, and species can also affect relationships of log1/LD50 between exposure routes.


Assuntos
Substâncias Perigosas/administração & dosagem , Substâncias Perigosas/toxicidade , Testes de Toxicidade Aguda/métodos , Administração Oral , Animais , Injeções Intramusculares , Injeções Intraperitoneais , Injeções Intravenosas , Injeções Subcutâneas , Dose Letal Mediana , Camundongos , Relação Quantitativa Estrutura-Atividade , Distribuição Tecidual/efeitos dos fármacos , Distribuição Tecidual/fisiologia , Testes de Toxicidade Aguda/normas
7.
Pest Manag Sci ; 80(2): 805-819, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37794206

RESUMO

BACKGROUND: Naturally occurring alkaloids are particularly suitable for use as pesticide precursors and further modifications due to their cost-effectiveness, unique mechanism of action, tolerable degradation, and environmental friendliness. The famous tobacco mosaic virus (TMV) is a persistent plant pathogenic virus that can parasitize many plants and severely reduce crop production. To treat TMV disease, TMV helicase acts as a crucial target by hydrolyzing adenosine triphosphate (ATP) to provide energy for double-stranded RNA unwinding. RESULTS: To seek novel framework alkaloid leads targeting TMV helicase, this work successfully established an efficient screening platform for TMV helicase inhibitors based on natural alkaloids. In vivo activity screening, enzyme activity detection, and binding assays showed that Rutaecarpine from Evodia rutaecarpa (Juss.) Benth exhibited excellent TMV helicase inhibitory properties [dissociation constant (Kd ) = 1.1 µm, half maximal inhibitory concentration (IC50 ) = 227.24 µm] and excellent anti-TMV ability. Molecular docking and dynamic simulations depicted that Rutaecarpine could stably bind in active pockets of helicase with low binding energy (ΔGbind = -17.8 kcal/mol) driven by hydrogen bonding and hydrophobic interactions. CONCLUSION: Given Rutaecarpine's laudable bioactivity and structural modifiability, it can serve as a privileged building block for further pesticide discovery.


Assuntos
Alcaloides , Alcaloides Indólicos , Praguicidas , Quinazolinonas , Vírus do Mosaico do Tabaco , Viroses , Simulação de Acoplamento Molecular , Nicotiana , Doenças das Plantas/prevenção & controle
8.
J Agric Food Chem ; 72(13): 6900-6912, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38513076

RESUMO

As a notorious phytopathogenic virus, the tobacco mosaic virus (TMV) severely reduced the quality of crops worldwide and caused critical constraints on agricultural production. The development of novel virucides is a persuasive strategy to address this predicament. Herein, a series of novel bisamide-decorated benzotriazole derivatives were elaborately prepared and screened. Biological tests implied that the optimized compound 7d possessed the most brilliant antiviral inactive profile (EC50 = 157.6 µg/mL) and apparently surpassed that of commercial ribavirin (EC50 = 442.1 µg/mL) 2.8-fold. The preliminary antiviral mechanism was elaborately investigated via transmission electron microscopy, microscale thermophoresis (MST) determination, RT-qPCR, and Western blot analysis. The results showed that compound 7d blocked the assembly of TMV by binding with coat protein (Kd = 0.7 µM) and suppressed TMV coat protein gene expression and biosynthesis process. Computational simulations indicated that 7d displayed strong H-bonds and pi interactions with TMV coat protein, affording a lower binding energy (ΔGbind = -17.8 kcal/mol) compared with Ribavirin (ΔGbind = -10.7 kcal/mol). Overall, current results present a valuable perception of bisamide decorated benzotriazole derivatives with appreciably virustatic competence and should be profoundly developed as virucidal candidates in agrochemical.


Assuntos
Ribavirina , Vírus do Mosaico do Tabaco , Triazóis , Relação Estrutura-Atividade , Ribavirina/farmacologia , Antivirais/farmacologia , Antivirais/química , Desenho de Fármacos
9.
Pest Manag Sci ; 80(8): 4098-4109, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38578108

RESUMO

BACKGROUND: Bacterial virulence factors are involved in various biological processes and mediate persistent bacterial infections. Focusing on virulence factors of phytopathogenic bacteria is an attractive strategy and crucial direction in pesticide discovery to prevent invasive and persistent bacterial infection. Hence, discovery and development of novel agrochemicals with high activity, low-risk, and potent anti-virulence is urgently needed to control plant bacterial diseases. RESULTS: A series of novel ß-hydroxy pyridinium cation decorated pterostilbene derivatives were prepared and their antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) were systematacially assessed. Among these pterostilbene derivatives, compound 4S exhibited the best antibacterial activity against Xoo in vitro, with an half maximal effective concentration (EC50) value of 0.28 µg mL-1. A series of biochemical assays including scanning electron microscopy, crystal violet staining, and analysis of biofilm formation, swimming motility, and related virulence factor gene expression levels demonstrated that compound 4S could function as a new anti-virulence factor inhibitor by interfering with the bacterial infection process. Furthermore, the pot experiments provided convinced evidence that compound 4S had the high control efficacy (curative activity: 71.4%, protective activity: 72.6%), and could be used to effectively manage rice bacterial leaf blight in vivo. CONCLUSION: Compounds 4S is an attractive virulence factor inhibitor with potential for application in treating plant bacterial diseases by suppressing production of several virulence factors. © 2024 Society of Chemical Industry.


Assuntos
Antibacterianos , Estilbenos , Fatores de Virulência , Xanthomonas , Xanthomonas/efeitos dos fármacos , Xanthomonas/patogenicidade , Estilbenos/farmacologia , Estilbenos/química , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Compostos de Piridínio/farmacologia , Compostos de Piridínio/química , Oryza/microbiologia , Amino Álcoois/farmacologia , Amino Álcoois/química , Biofilmes/efeitos dos fármacos
10.
J Craniofac Surg ; 24(3): e260-5, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23714985

RESUMO

Computer-aided design has gained increasing popularity in clinical practice, and the advent of rapid prototyping technology has further enhanced the quality and predictability of surgical outcomes. It provides target guides for complex bony reconstruction during surgery. Therefore, surgeons can efficiently and precisely target fracture restorations. Based on three-dimensional models generated from a computed tomographic scan, precise preoperative planning simulation on a computer is possible. Combining the interdisciplinary knowledge of surgeons and engineers, this study proposes a novel surgical guidance method that incorporates a built-in occlusal wafer that serves as the positioning reference.Two patients with complex facial deformity suffering from severe facial asymmetry problems were recruited. In vitro facial reconstruction was first rehearsed on physical models, where a customized surgical guide incorporating a built-in occlusal stent as the positioning reference was designed to implement the surgery plan. This study is intended to present the authors' preliminary experience in a complex facial reconstruction procedure. It suggests that in regions with less information, where intraoperative computed tomographic scans or navigation systems are not available, our approach could be an effective, expedient, straightforward aid to enhance surgical outcome in a complex facial repair.


Assuntos
Desenho Assistido por Computador , Assimetria Facial/cirurgia , Marcadores Fiduciais , Planejamento de Assistência ao Paciente , Procedimentos de Cirurgia Plástica/métodos , Contenções , Cirurgia Assistida por Computador , Adolescente , Simulação por Computador , Feminino , Displasia Fibrosa Óssea/cirurgia , Fraturas Cominutivas/cirurgia , Osso Frontal/lesões , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Registro da Relação Maxilomandibular/instrumentação , Masculino , Doenças Mandibulares/cirurgia , Reconstrução Mandibular/métodos , Maxila/cirurgia , Pessoa de Meia-Idade , Modelos Anatômicos , Órbita/cirurgia , Fraturas Orbitárias/cirurgia , Osteotomia de Le Fort/métodos , Tomografia Computadorizada por Raios X/métodos , Interface Usuário-Computador , Fraturas Zigomáticas/cirurgia
11.
Water Sci Technol ; 67(8): 1695-700, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23579822

RESUMO

A prototype capable of generating underwater high-voltage discharges (3.5 kV) coupled with water plasma expansion was constructed. The level of phytomass disintegration caused by transmission of the pressure shockwaves (50-60 MPa) followed by this expansion was analyzed using gas adsorption techniques. The dynamics of the external surface area and the micropore volume on multiple pretreatment stages of maize silage and sunflower seeds was approximated with robust analytical techniques. The multiple increases on the reaction surface were manifest in up to a 15% increase in cumulative methane production, which was itself manifest in the overall acceleration of the anaerobic fermentation process. Disintegration of the sunflower seeds allowed up to 45% higher oil yields using the same operating pressure.


Assuntos
Biomassa , Eletricidade , Biocombustíveis , Helianthus , Pressão , Água , Zea mays
12.
J Xray Sci Technol ; 21(2): 251-82, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23694914

RESUMO

Recent advances in cone-beam computed tomography (CBCT) have rapidly enabled widepsread applications of dentomaxillofacial imaging and orthodontic practices in the past decades due to its low radiation dose, high spatial resolution, and accessibility. However, low contrast resolution in CBCT image has become its major limitation in building skull models. Intensive hand-segmentation is usually required to reconstruct the skull models. One of the regions affected by this limitation the most is the thin bone images. This paper presents a novel segmentation approach based on wavelet density model (WDM) for a particular interest in the outer surface of anterior wall of maxilla. Nineteen CBCT datasets are used to conduct two experiments. This mode-based segmentation approach is validated and compared with three different segmentation approaches. The results show that the performance of this model-based segmentation approach is better than those of the other approaches. It can achieve 0.25 ± 0.2 mm of surface error from ground truth of bone surface.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Imageamento Tridimensional/métodos , Maxila/diagnóstico por imagem , Análise de Ondaletas , Algoritmos , Inteligência Artificial , Bases de Dados Factuais , Humanos , Modelos Estatísticos , Reprodutibilidade dos Testes
13.
Front Aging Neurosci ; 15: 1241237, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37693646

RESUMO

Introduction: Idiopathic normal pressure hydrocephalus (INPH) is a potentially reversible syndrome characterized by complex symptoms, difficulty in diagnosis and a lack of detailed clinical description, and it is difficult to distinguish from Alzheimer's disease (AD). The objective of this study was to design a method for measuring the actual amount of hydrocephalus in patients with INPH and to evaluate INPH. Methods: All subjects underwent a 3D T1-weighted MRI. Statistical parametric mapping 12 was used for preprocessing images, statistical analysis, and voxel-based morphometric gray matter (GM) volume, white matter (WM) volume, and cerebrospinal fluid (CSF) volume analysis. The demographic and clinical characteristics of the groups were compared using a t-test for continuous variables and a chi-square test for categorical variables. Pearson's correlation analysis and Bonferroni's statistic-corrected one-way ANOVA were used to determine the relationship among demographic variables. Receiver operating characteristic (ROC) curves were used to assess the accuracy of the callosal angle (CA), WM ratio, and CSF ratio in distinguishing probable INPH from AD. Results: The study included 42 patients with INPH, 32 patients with AD, and 24 healthy control subjects (HCs). There were no differences among the three groups in basic characteristics except for Mini-Mental State Examination (MMSE). There was a correlation between the intracranial CSF ratio and CA. The WM ratio and CSF ratio in patients with INPH and AD were statistically different. Furthermore, the combination of CA, WM ratio, and CSF ratio had a greater differential diagnostic value between INPH and AD patients than CA alone. Conclusion: INPH can be accurately assessed by measuring intracranial CSF ratio, and the addition of WM ratio and CSF ratio significantly improved the differential diagnostic value of probable INPH from AD compared to CA alone.

14.
Anal Chim Acta ; 1279: 341790, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37827684

RESUMO

Microdroplet mass spectrometry (MMS), achieving ultra-fast enzyme digestion in the ionization source, holds great promises for innovating protein analysis. Here, in-depth protein characterization is demonstrated by direct injection of intact protein mixtures via on-line coupling MMS with capillary C4 liquid chromatography (LC) containing UV windows (UVLC-MMS) through an enzyme introduction tee. We showed complete sets of peptides of individual proteins (hemoglobin, bovine serum albumin, and ribonuclease A) in a mixture could be obtained in one injection. Such full (100%) sequence coverage, however, could not be achieved by conventional nanoLC-MS method using bottom-up approach with single enzyme. Moreover, direct injection of a chaperone α-crystalline (α-Cry) complex yielded identification of post-translational modifications including novel sites and semi-quantitative characterization including 3:1 stoichiometry ratio of αA- and αB-Cry sub-units and ∼1.4 phosphorylation/subunit on S45 (novel site) and S122 (main site) of αA-Cry, ∼0.7 phosphorylation/subunit on S19 (main site) and S45 of αB-Cry, as well as 100% acetylation on both N-termini of each subunits by matching the mass and retention time of the intact and its digested peptides. Furthermore, trifluoroacetic acid was able to be used in the mobile phase with UVLC-MMS to improve the separation of differentially reduced intact species and detectability of the droplet-digested products. This allowed us to completely map four disulfide linkages of ribonuclease A based on collision-induced dissociation of disulfide clusters, some of which would otherwise not be detected, preventing scrambling or shuffling errors arising from lengthy bulk solution digestion by the bottom-up approach. Integration of UVLC and MMS greatly improves droplet digestion efficiency and MS detection, enabling highly efficient workflow for in-depth and accurate protein characterization.


Assuntos
Dissulfetos , Ribonuclease Pancreático , Dissulfetos/química , Sequência de Aminoácidos , Cromatografia Líquida/métodos , Peptídeos/análise , Espectrometria de Massas/métodos , Proteínas , Ribonucleases
15.
J Agric Food Chem ; 71(6): 2804-2816, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36744848

RESUMO

Discovering new anti-virulent agents to control plant bacterial diseases by preventing bacterial pathogenesis/pathogenicity rather than affecting bacterial growth is a sensible strategy. However, the effects of compound-manipulated bacterial virulence factors on host response are still not clear. In this work, 35 new 1,3,4-oxadiazole derivatives were synthesized and systematically evaluated for their anti-phytopathogenic activities. Bioassay results revealed that compound C7 possessed outstanding antibacterial activity in vitro (half-maximal effective concentration: 0.80 µg/mL) against Xanthomonas oryzae pv. oryzae (Xoo) and acceptable bioactivity in vivo toward rice bacterial leaf blight. Furthermore, virulence factor-related biochemical assays showed that C7 was a promising anti-virulent agent. Interestingly, C7 could indirectly reduce the inducible expression of host SWEET genes and thereby alleviate nutrient supply in the infection process of phytopathogenic bacteria. Our results highlight the potential of 1,3,4-oxadiazole-based agrochemicals for manipulating type III secretion system-induced phytopathogenic bacteria starvation mechanisms to prevent plant bacterial diseases.


Assuntos
Infecções Bacterianas , Oryza , Xanthomonas , Sistemas de Secreção Tipo III/genética , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia , Oxidiazóis/farmacologia , Oxidiazóis/química , Fatores de Virulência/metabolismo , Xanthomonas/genética , Oryza/metabolismo , Antibacterianos/química
16.
Eur J Med Chem ; 250: 115215, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36812655

RESUMO

Bacterial survival depends on membrane lipid homeostasis that enables to regulate lipid composition to adapt and optimize their growth in diverse environments. Therefore, the development of inhibitors that interfere with the bacterial fatty acid synthesis process is considered to be a promising tactic. In this study, 58 novel spirochromanone derivatives were prepared and their structure-activity relationship (SAR) was investigated. The bioassay results showed that all most of the compounds showed excellent biological activities, exampled by compounds B14, C1, B15, and B13, which had outstanding inhibitory activities toward various pathogenic bacteria with EC50 values of 0.78 µg/mL ∼3.48 µg/mL. Preliminary antibacterial behavior was studied by a series of biochemical assays including, but not limited to, fluorescence imaging patterns, GC-MS analysis, TEM images, and fluorescence titration experiments. Notably, compound B14 decreased the lipid content of the cell membrane, and increased cell membrane permeability, thereby destroying the integrity of the bacterial cell membrane. Further qRT-PCR results indicated that compound B14 interfered with the mRNA expression levels of fatty acid synthesis process-related genes including ACC, ACP, and Fab family genes. Herein, we highlight the promising bactericidal skeleton based on the spiro[chromanone-2,4'-piperidine]-4-one as a potential inhibitor of fatty acid synthesis.


Assuntos
Bactérias , Piperidinas , Relação Estrutura-Atividade , Ácidos Graxos/farmacologia , Lipídeos , Antibacterianos/química , Testes de Sensibilidade Microbiana
17.
J Agric Food Chem ; 71(14): 5463-5475, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37012216

RESUMO

The discovery of natural product-based pesticides is critical for agriculture. In this work, a series of novel tricyclic diterpenoid derivatives decorated with an amino alcohol moiety were elaborately prepared from natural abietic acid, and their antibacterial behavior was explored. Bioassay results indicated that compound C2 exhibited the most promising bioactivity (EC50 = 0.555 µg mL-1) against Xanthomonas oryzae pv. oryzae (Xoo), about 73 times higher than the effect of commercial thiodiazole copper (TC). Results of in vivo bioassays showed that compound C2 displayed significantly higher control of rice bacterial leaf blight (curative activity: 63.8%; protective activity: 58.4%) than TC (curative activity: 43.6%; protective activity: 40.8%), and their bioactivity could be improved maximally 16% by supplementing the auxiliaries. Antibacterial behavior suggested that compound C2 could suppress various virulence factors. Overall, these findings suggested that new botanical bactericide candidates could control intractable plant bacterial diseases by suppressing virulence factors.


Assuntos
Antibacterianos , Oxidiazóis , Testes de Sensibilidade Microbiana , Fatores de Virulência , Gerenciamento Clínico
18.
J Agric Food Chem ; 71(17): 6525-6540, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37073686

RESUMO

As quorum sensing (QS) regulates bacterial pathogenicity, antiquorum sensing agents have powerful application potential for controlling bacterial infections and overcoming pesticide/drug resistance. Identifying anti-QS agents thus represents a promising approach in agrochemical development. In this study, the anti-QS potency of 53 newly prepared benzothiazole derivatives containing an isopropanolamine moiety was analyzed, and structure-activity relationships were examined. Compound D3 exhibited the strongest antibacterial activity, with an in vitro EC50 of 1.54 µg mL-1 against Xanthomonas oryzae pv oryzae (Xoo). Compound D3 suppressed QS-regulated virulence factors (e.g., biofilm, extracellular polysaccharides, extracellular enzymes, and flagella) to inhibit bacterial infection. In vivo anti-Xoo assays indicated good control efficiency (curative activity, 47.8%; protective activity, 48.7%) at 200 µg mL-1. Greater control efficiency was achieved with addition of 0.1% organic silicone or orange peel essential oil. The remarkable anti-QS potency of these benzothiazole derivatives could facilitate further novel bactericidal compound development.


Assuntos
Infecções Bacterianas , Oryza , Xanthomonas , Benzotiazóis , Percepção de Quorum , Biofilmes , Antibacterianos/farmacologia , Doenças das Plantas , Testes de Sensibilidade Microbiana
19.
J Nanosci Nanotechnol ; 12(4): 3402-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22849133

RESUMO

In aqueous solution, the agglomeration of silica nanopowder is a major problem which causes poor uniformity of electroplated surfaces. Silica surface is susceptible to moisture due to the hydroxyl group on its surface which causes the silica nanopowder to become agglomerated. In this study, silica nanoparticle dispersion in the electroplated layer is reported. From zeta potential analysis, silica nanopowder has a negatively charged surface in an alkaline bath. Silica nanopowder is less agglomerated in an alkaline bath than in an acidic bath due to the surface charge. Additives change the surface morphologies of the electroplated layer as well as the silica nanopowder contents. Comparing an alkaline bath and an acidic bath, the advantage of an additive to the electroplated layer is only observed in an alkaline bath. Types of sonicators and sonication periods are also surveyed for silica nanopowder dispersion. Sonication time can be reduced by a horn-type sonicator, and longer sonication time guaranteed better silica nanopowder dispersion.

20.
Metabolites ; 12(6)2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35736463

RESUMO

Sea bass (Lates calcarifer) is rich in protein, amino acids, and long-chain omega 3 (omega-3), which have many health benefits. In East Asian food culture, soup is often eaten as a nutritional supplement. The purpose of this study was to investigate the benefits of Hi-Q sea bass essence (SBE) supplementation for improved exercise performance and anti-fatigue. Fifty male Institute of Cancer Research (ICR) mice were divided to five groups (10 mice/group) and administered different doses of SBE (EC): (1) vehicle (water); (2) isocaloric (0.94 g casein/kg/mice/day); (3) SBE-1X (1.04 g/kg/mice/day); (4) SBE-2X (2.08 g/kg/mice/day); and (5) SBE-4X (4.16 g/kg/mice/day). We found that SBE supplementation significantly improved more than 1.96-fold endurance exercise performance (p < 0.05) and more than 1.13-fold glycogen storage in the liver and muscles (p < 0.05), and had dose-dependent by SBE dose (p < 0.05). In addition, supplementation with SBE at different doses had significant effects on the fatigue-related biochemical markers, i.e., lactate, ammonia, and blood urea nitrogen (BUN) levels were reduced significantly (p < 0.05), and were also dose-dependent. In conclusion, supplementation with SBE for 4 weeks was able to effectively improve exercise performance and had an anti-fatigue effect. In addition, it did not cause any physiological or histopathological damage.

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