490 research outputs found

    Perfect category-graded algebras

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    In a perfect category every object has a minimal projective resolution. We give a criterion for the category of modules over a categorygraded algebra to be perfect.Comment: A sufficient condition is replaced by a criterion. Several references added. 17 page

    Potential of Panamanian aromatic flora as a source of novel essential oils

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    Flora of Panama is one of the richest in the world and occupies fourth place in vascular plant diversity in the American content. Many plants of the families interalia Apiaceae, Asteraceae, Lauraceae, Lamiaceae, Myrtaceae, Piperaceae, Rutaceae, Rosaceae and Sapindaceae have yielded essential oils (EOs). A summary of results on chemical composition and biological activities of 20 EOs from selected Panamanian plants is provided here, which shows the potential of aromatic flora of Panama. Six species of Piper had sesquiterpene hydrocarbons as major components, three were characterized by monoterpene hydrocarbons, and one by a phenylpropanoid, dillapiole. EOs of P. hispidum and P. longipsicum at a concentration of 250μg/ml showed larvicidal activity against Aedes aegypti, while P. multiplinervium against Helicobacter pylori (IC50 = 0.1μg/mL). The main components of EOs from 9 species belonging to 4 genera: Eugenia, Calyptranthes, Eugenia, Plinia, and Myrcia were sesquiterpene hydrocarbons (E-caryophyllene) or oxygenated sesquiterpenes (α-bisabolol). EO of E. acapulensis showed strong antimicrobial activity against Staphylococcus aureus (MIC=125μg/mL) and Mycobacteria smegmatis (MIC=250μg/mL)

    Measuring the 7Cs of Vaccination Readiness

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    Abstract. Although vaccines are among the most effective interventions used in fighting diseases, vaccination readiness varies substantially among individuals. Vaccination readiness is defined as a set of components that increase or decrease AN individual’s likelihood of getting vaccinated. Building on earlier work that distinguished five components of vaccination readiness (confidence, complacency, constraints, calculation, and collective responsibility), we revised the questionnaire used to measure these components to improve its psychometric properties, specifically criterion validity. In doing so, we also developed two new components of vaccination readiness: compliance and conspiracy. Compliance is the tendency to support monitoring to control adherence to regulations; conspiracy is the tendency to endorse conspiratorial beliefs about vaccination. The newly introduced 7C scale was initially piloted in a cascade of serial cross-sectional studies and then validated with N = 681 participants from the COVID-19 Snapshot Monitoring in Denmark. We report a bifactor measurement model, convergent validity with other questionnaires, and an explanation of 85% variance in the willingness to vaccinate against COVID-19. We also present a 7-item short version of the scale. The instrument is publicly available in several languages ( www.vaccination-readiness.com ), and we seek collaboration to provide translations of our instrument into other languages

    Anti-malarial activity and HS-SPME-GC-MS chemical profiling of Plinia cerrocampanensis leaf essential oil

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    Plinia cerrocampanensis is an endemic plant of Panama. The leaf essential oil of this plant has shown antibacterial activity. However, anti-malarial activity and chemical profiling by HS-SPME-GC-MS of this essential oil have not been reported before. Anti-malarial activity of the essential oil (EO) was evaluated in vitro against chloroquine-sensitive HB3 and chloroquine-resistant W2 strains of Plasmodium falciparum. Synergistic effect of chloroquine and the EO on parasite growth was evaluated by calculating the combination index. A methodology involving headspace solid phase microextraction and gas chromatography-mPlinia cerrocampanensis is an endemic plant of Panama. The leaf essential oil of this plant has shown antibacterial activity. However, anti-malarial activity and chemical profiling by HS-SPME-GC-MS of this essential oil have not been reported before. Anti-malarial activity of the essential oil (EO) was evaluated in vitro against chloroquine-sensitive HB3 and chloroquine-resistant W2 strains of Plasmodium falciparum. Synergistic effect of chloroquine and the EO on parasite growth was evaluated by calculating the combination index. A methodology involving headspace solid phase microextraction and gas chromatography-

    Anti-malarial activity and HS-SPME-GC-MS chemical profiling of Plinia cerrocampanensis leaf essential oil

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    Plinia cerrocampanensis is an endemic plant of Panama. The leaf essential oil of this plant has shown antibacterial activity. However, anti-malarial activity and chemical profiling by HS-SPME-GC-MS of this essential oil have not been reported before. Anti-malarial activity of the essential oil (EO) was evaluated in vitro against chloroquine-sensitive HB3 and chloroquine-resistant W2 strains of Plasmodium falciparum. Synergistic effect of chloroquine and the EO on parasite growth was evaluated by calculating the combination index. A methodology involving headspace solid phase microextraction and gas chromatography-mPlinia cerrocampanensis is an endemic plant of Panama. The leaf essential oil of this plant has shown antibacterial activity. However, anti-malarial activity and chemical profiling by HS-SPME-GC-MS of this essential oil have not been reported before. Anti-malarial activity of the essential oil (EO) was evaluated in vitro against chloroquine-sensitive HB3 and chloroquine-resistant W2 strains of Plasmodium falciparum. Synergistic effect of chloroquine and the EO on parasite growth was evaluated by calculating the combination index. A methodology involving headspace solid phase microextraction and gas chromatography-

    PUFFIN: A Path-Unifying Feed-Forward Interfaced Network for Vapor Pressure Prediction

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    Accurately predicting vapor pressure is vital for various industrial and environmental applications. However, obtaining accurate measurements for all compounds of interest is not possible due to the resource and labor intensity of experiments. The demand for resources and labor further multiplies when a temperature-dependent relationship for predicting vapor pressure is desired. In this paper, we propose PUFFIN (Path-Unifying Feed-Forward Interfaced Network), a machine learning framework that combines transfer learning with a new inductive bias node inspired by domain knowledge (the Antoine equation) to improve vapor pressure prediction. By leveraging inductive bias and transfer learning using graph embeddings, PUFFIN outperforms alternative strategies that do not use inductive bias or that use generic descriptors of compounds. The framework's incorporation of domain-specific knowledge to overcome the limitation of poor data availability shows its potential for broader applications in chemical compound analysis, including the prediction of other physicochemical properties. Importantly, our proposed machine learning framework is partially interpretable, because the inductive Antoine node yields network-derived Antoine equation coefficients. It would then be possible to directly incorporate the obtained analytical expression in process design software for better prediction and control of processes occurring in industry and the environment

    Ethnomedical uses and pharmacological activities of most prevalent species of genus Piper in Panama: A review

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    Ethnopharmacogical relevance: Piperaceae is the fifth largest family of plants in Panama. This review focuses on the ethnomedical uses of the most prevalent Panamanian species and biological activities of their extracts and/or constituents both in Panama and worldwide. Many species have a plethora of ethnomedical uses such as antibacterial, antifungal, anti-inflammatory, anticancer, antidiabetic, anti-Helicobacter pylori, antiulcer, antiprotozoal, estrogenic, insecticidal, local anesthetic, diuretic, and for women’s health conditions. Aim of the review: The aim of this review is to compile all ethnomedical uses of most prevalent species of Piper in Panama, and their extracts or phytoconstituents worldwide, through a complete literature search, so that it may allow selection of potential unexplored Piper species for future research and development of phytotherapeuticals for important ailments

    Seasonal variation in the production of secondary metabolites and antimicrobial activity of two plant species used in Brazilian traditional medicine

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    Guapira graciliflora and Pseudobombax marginatum are two species used in the treatment of various diseases in traditional medicine of the Brazilian semiarid region, but no studies assessing their phytochemical and pharmacological properties have been reported. This study aimed to evaluate seasonal variation in the production of secondary metabolites and antimicrobial activity of these plants. The broth microdilution test was used against pathogenic microorganisms to evaluate the antimicrobial activity. The content of total polyphenols and flavonoids was determined by ultra violet (UV) spectrophotometry using gallic acid and quercetin as standards respectively. The concentration of polyphenols was higher in winter for P. marginatum and in summer for G. graciliflora, while for flavonoids the opposite occurred. Regarding the antimicrobial activity, only P. marginatum showed inhibition against seven tested strains and antibiosis against four, with variation in the minimum inhibitory concentration (MIC) and minimum microbicide concentration (MMC) between the two seasons. G. graciliflora showed no activity. The results show that the chemical composition of the extracts from P. marginatum and G. gracilliflora exhibits seasonal variation, with the first plant showing moderate antimicrobial activity.Keywords: Seasonal variation, phenolic compounds, medicinal plants, Gapira graciliflora, Pseudobombax marginatumAfrican Journal of Biotechnology Vol. 12(8), pp. 847-85

    Schinopsis brasiliensis engl. to combat the biofilm-dependents diseases in vitro

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    Dental caries and periodontal disease are the most prevalent of the biofilm-dependent diseases. With numerous side effects on the use of chlorhexidine, the search for new safe therapeutic alternatives for microorganisms involved with these diseases increases every day. This study aimed to evaluate the antimicrobial activity and cytotoxicity of extracts made from the bark of Schinopsis brasiliensis Engl. against five oral microorganisms and analyze their phytochemical and thermal degradation profile. The liquid-liquid partition was performed with hexane, chloroform and ethyl acetate. The identification and quantification of the chemical marker was done. Antimicrobial activity was evaluated based on the minimum inhibitory concentration. The cytotoxicity was analyzed based on the hemolysing potential of the samples. The thermal degradation profile was performed by two different methods. Gallic acid was identified as the main compound of the samples and showed the highest amount in the chloroform fraction. All samples were able to inhibit the growth of the microorganisms tested and showed no cytotoxicity. The ethanol extract absorbs less heat than the fractions. All samples exhibited exothermic peak consistent with degradation of gallic acid. Based on the results, the samples used are potential candidates for use in dental formulations for biofilm control924CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSem informaçã

    The role of Cis-Regulatory elements in morphological adaptation to cave environment in Astyanax mexicanus

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    Trabajo presentado en EMBO Workshop Enhanceropathies: Understanding enhancer function to understand human disease, celebrado en Santander (España) del 06 al 09 de octubre de 2021
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