156 research outputs found

    Syntheses, Characterization, and Antimicrobial Screening of N-(benzothiazol-2-yl)-2-nitrobenzenesulphonamide and its Cu(I), Ni(II), Mn(II), Co(II) and Zn(II) Complexes

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    N-(benzothiazol-2-yl)-2-nitrobenzenesulphonamide (NBS2ABT) was synthesized by the condensation of 2-aminobenzothiazole and 2-nitrobenzenesulphonylchloride under reflux. Five metal complexes of Cu(I), Ni(II), Mn(II), Co(II) and Zn(II) of the ligands were synthesized. The compounds were characterized using magnetic susceptibility measurements, mass spectrometry, elemental microanalysis, UV/VIS spectrophotometry, infra red, 1H and 13C nmr spectroscopies. The antimicrobial tests of the ligands and its metal complexes were carried out on both multi-resistant bacterial strains isolated under clinical conditions and cultured species using agar-well diffusion method. The multi-resistant bacterial strains used were E. coli, Proteus species, P. aeroginosa and S. aureus which were isolated from dogs. The culture species were P. aeruginosa (ATCC 27853), E. coli (ATCC 25922), S. aureus (ATCC 25923), and the fungi, C. krusei (ATCC 6258) and C. albicans (ATCC 90028). The tests were both in vitro and in vivo. The antimicrobial activities of the compounds were compared with those of Ciprofloxacin and trimethoprim-sulphamethoxazole as antibacterial agents and Fluconazole as an antifungal drug. All the compounds showed varying activities against the cultured typed bacteria and fungi used. The Lethal Concentration (LC50) ranged from 5.00±0.86-618.90±30.8 ppm. These are within the permissible concentrations. Key words: N-(benzothiazol-2-yl)-2-nitrobenzenesulphonamide, Metal complexes, Antimicrobial, Ligan

    Application of High-Voltage, Precision, Low-Power Max9943/Max9944 Operational Amplifier in Industrial Process Control Using ±20ma OR 4-20ma Current-Loop Systems

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    This article explains how to apply a high-voltage, high-current-drive operational amplifier to convert a voltage signal into a ±20mA or 4–20mA current signal for use in process-control industrial applications. The MAX9943 op amp a family of high-voltage amplifiers that offers precision, low drift, and low power consumption device was used as case study]. Experiments are described and test results presented. Current loops are known for their high immune to noise compare to voltage-modulated signals, a feature that makes it ideal for use in a noisy industrial environment. This signal can travel over a long distance, sending or receiving information from remote locations. A current loop typically includes a sensor, transmitter, receiver, and an ADC or a micro-controller (figure 1). The sensor measures a physical parameters such as pressure or temperature and provides a corresponding output voltage. The transmitter converts the sensor's output into a proportional 4mA-to-20mA current signal, while the receiver then converts the 4mA-to-20mA current into a voltage signal output. This receiver's output is then received, interpreted and converts into a digital signal output by an ADC or a micro-controller. Experiment performed using the relationship the relationship stated in equation 5, shows that if the input voltage level rise above or fall below ±2.5v, the op amp device attains its saturation point and its output voltage can no longer increase. As shown in figure 3, where the curve flatten and no longer follow the ideal linearity characteristics that was supposed

    X-ray crystallographic and structural studies of (benzothiazol-2-yl)ethanesulphonamide, and its antimicrobial properties

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    N-(benzothiazol-2-yl)ethanesulphonamide (ES2ABT) was synthesized by the condensation of 2-aminobenzothiazole and ethanesulphonylchloride in acetone at 130 °C. The resulting crude precipitates were recrystallized in absolute ethanol. ES2ABT was characterized using X-ray crystallography, mass spectrometry, elemental microanalysis, UV/VIS spectrophotometry, infra red, proton and 13C NMR spectroscopies. The antimicrobial tests of the compound were carried out on both multi-resistant bacterial strains isolated under clinical conditions and cultured species using agar-well diffusion method. The multi-resistant bacterial strains used were Escherichia coli, Proteus species, Pseudomonas aeroginosa and Staphylococcus aureus which were isolated from dogs. The culture species were Pseudomonas aeruginosa (ATCC 27853), Escherichia Coli (ATCC 25922) Staphylococcus aureus (ATCC 25923), and the fungi, Candida krusei (ATCC 6258) and Candida albicans (ATCC 90028). The tests were both in vitro and in vivo. Thus the Inhibition Zone Diameter (IZD), the Minimum Inhibitory Concentration (MIC), and the Lethal and Effective Concentrations (LC50 and EC50) were determined. The antimicrobial activity of the compound was compared with those of Ciprofloxacin and trimethoprim-sulphamethoxazole as antibacterial agents and Fluconazole as an antifungal drug. The compound showed varying activity against the cultured typed bacteria and fungi used. However, ES2ABT was less active than the antibacterial standard drugs used but not Fluconazole which did not show any activity against Candida krusei (ATCC 6258). The Lethal Concentration (LC50) is 338.80 ± 28.6 ppm. This is within the permissible concentrations. Key words: N-(benzothiazol-2-yl)ethanesulphonamide, antimicrobial, in vivo, in vitr

    Analysis of Electrical Porcelain Insulators from Local Clays

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    This paper focused on the chemical analysis of electrical porcelain insulators based on local clays. Test samples were made by conducting some chemical composition test using the Atomic Assumption Spectrophotometer (AAS). The clay samples were also tested for linear shrinkage and apparent porosity. Based on the results obtained, the linear shrinkage values recorded range from 7.29% to 14.29% for Iva Valley formulations, 5.14% to 14.71% for Nawfija and 7.74% to 10.29% for Ekwulobia. It was observed that linear shrinkage decreases as the content of non-plastic materials increases and increases as clay content increases. Iva Valley formulation recorded porosity values ranging from 8.84% to 20.80%. For Nawfija formulation, porosity values range from 10.81% to 17.30% while Ekwulobia formulations gave porosity values ranging from 9.52% to 16.82. Porcelain insulators that constitute the above results were found to have requisite properties that make them suitable for domestic production of porcelains insulators from the clay samples studied

    Antimicrobial activities of secondary metabolites of endophytic fungi isolated from Catharanthus roseus

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    Introduction: Recently, several endophytes have been shown to possess the potentials to synthesize novel bioactive compounds that have found use for drug discovery. We isolated endophytic fungi associated with Catharanthus roseus collected from the river banks of Amassoma in Southern Nigeria, and identified some of their bioactive secondary metabolites. Methods: The fungi were subjected to solid-state fermentation on rice medium and the metabolites were extracted using ethyl acetate. The fungal crude extracts were screened for antimicrobial activity and were also subjected to high-performance liquid chromatography-diode-array detection (HPLC-DAD) analysis for the identification of the bioactive compounds. Results: The fungal extracts showed both antibacterial and antifungal activities with minimum inhibitory concentrations ranging from 0.0625 to 1 mg/mL. The HPLC-DAD analysis of the extracts suggested the presence of citreoisocoumarin, citreoisocoumarinol, questinol, hydroxyemodin, acropyrone, methyl 2-(4-hydroxyphenyl) acetate, nigricinol, and cladosporin. Conclusion: The results of this study suggest that endophytic fungi associated with C. roseus could be a promising source of novel bioactive compounds with pharmaceutical and industrial importance

    Antimicrobial activities of secondary metabolites of endophytic fungi isolated from Catharanthus roseus

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    Introduction: Recently, several endophytes have been shown to possess the potentials to synthesize novel bioactive compounds that have found use for drug discovery. We isolated endophytic fungi associated with Catharanthus roseus collected from the river banks of Amassoma in Southern Nigeria, and identified some of their bioactive secondary metabolites. Methods: The fungi were subjected to solid-state fermentation on rice medium and the metabolites were extracted using ethyl acetate. The fungal crude extracts were screened for antimicrobial activity and were also subjected to high-performance liquid chromatography-diode-array detection (HPLC-DAD) analysis for the identification of the bioactive compounds. Results: The fungal extracts showed both antibacterial and antifungal activities with minimum inhibitory concentrations ranging from 0.0625 to 1 mg/mL. The HPLC-DAD analysis of the extracts suggested the presence of citreoisocoumarin, citreoisocoumarinol, questinol, hydroxyemodin, acropyrone, methyl 2-(4-hydroxyphenyl) acetate, nigricinol, and cladosporin. Conclusion: The results of this study suggest that endophytic fungi associated with C. roseus could be a promising source of novel bioactive compounds with pharmaceutical and industrial importance

    Neuropharmacological evaluation of Annona senegalensis leaves

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    The neuropharmacological activities of methanol leaf extract (ME) of Annona senegalensis Pers (Annonaceae) and its bioactive fractions (MF and F7) were studied in rodents using pentylenetetrazol (PTZ)-induced seizures, pentobarbitone-induced sleep, apomorphine-induced stereotypy, open field, elevated plus maze (EPM) and rotarod performance tests. The extract and fractions inhibited PTZ-induced seizures, prolonged pentobarbitone-induced sleep, reduced stereotypic behaviour induced by apomorphine, decreased the frequency of line crossing and centre square entries and increased rearing in the air in the open field. The frequency of grooming and rearing against the wall were decreased, whereas the duration of grooming increased. Also, the extract and fractions increased the duration of stay in the open arm when compared to the closed arm of the EPM, and reduced the average time spent on the rotarod. Acute toxicity test showed an oral LD50 of ME greater than 5 g/kg in mice. Phytochemical analysis showed that ME tested positive for carbohydrates, reducing sugar, resins, saponins,  tannins, steroids, terpenoids, alkaloids, flavonoids and glycosides; MF tested positive for saponins, steroids, terpenoids, alkaloids, carbohydrates, reducing sugar, flavonoids and glycosides; while F7 tested positive for flavonoids. These findings suggest that leaves of A. senegalensis possess anticonvulsant, central depressant and anxiolytic-like properties attributable to flavonoids.Keywords: Annona senegalensis, anticonvulsant, anxiolytic, sedative, stereotypy

    Toxicity study of diethyl phthalate on Clarias gariepinus fingerlings

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    Diethyl Phthalate (DEP) is used as a plasticizer, a detergent base, in aerosol sprays, as a perfume binder and after shave lotion. It is known to be a contaminant of fresh water and marine ecosystem. Therefore, a study was designed to determine the acute toxicity effects of DEP on a fresh water fish, Clarias gariepinus fingerlings. The fish was treated with 50, 75, 100 and 150 μg/l. DEP was dissolved in distilled water to determine the LC50. There was 100% mortality observed in 150 μg/l. The LC50 of DEP was estimated at log toxicant concentration as 2.217, 2.734, 3.435 and 3.931 μg/l at 24, 48, 72, 96 h and 1.871μg/l for the total death. This shows that the impacts are dose and time dependent with respect to marked reduction in mortality rate. At sub-lethal concentrations of the test substance at 30, 40, 60 and 80 μg/l in a renewal bioassay system, the water and the test compound were changed intermittently. One group was maintained as a control in dechlorinated water. There was significant difference (P < 0.05) in brain and muscle AchE activity compared to the control. The liver ACP activity was statistically significant (P < 0.05) at day 15 while the muscle ACP in other treatment groups showed no significant difference (P > 0.05). Liver AST showed no significance in all treated groups (P > 0.05) and liver ALT activity was statistically significant (P < 0.05) at day 30 only. The haematological parameters (HB, PCV, RBC and WBC) carried out showed that haemoglobin and erythrocyte levels estimated in all treatment groups to the duration of exposure showed no significant difference (P > 0.05) compared to the control. The park cell volume showed a significant difference (P < 0.05) at day 30 only. The leucocyte count throughout the exposure period showed that the mean values are statistically significant (P < 0.05) at day 15 only compared to the control. The mean cell volume (MCV) showed a significant difference at day 15 (P < 0.05) whereas mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC) showed no significant difference (P > 0.05) throughout the exposure period. No significant difference was seen between the lymphocytes and the neutrophils. In day 0 and 15 only, the monocytes and the lymphocytes showed a significant difference (P < 0.05). The gill damages indicated toxicity of DEP with raised lamella, oedema of the lamella epithelia, loss of lamellar epithelium, mild oedema and raising of the filament. The liver damage showed focal necrosis and vacuolization, hepatocyte degeneration in the liver. These alterations may have long term effects on that that are continuously exposed to DEP in the aquatic environment.Keywords: Diethyl phthalate, Clarias gariepinus, acute toxicity, sublethal toxicity, heamatology, biochemical, histopathology, environment

    Biologically active phenolic acids produced by Aspergillus sp., an endophyte of Moringa oleifera

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    This study investigates the secondary metabolites of an endophytic Aspergillus sp. isolated from leaves of M. oleifera growing in Anambra State, South-Eastern Nigeria. Antimicrobial and antioxidant screening of the fungal extract and isolated compounds, as well as cytotoxicity assay of the extract against cisplatin-sensitive A2780 (sens) and cisplatin-resistant A2780 (cisR) ovarian cancer cell lines were carried out using standard methods. Chemical investigations of the fungal extract involving a combination of different chromato-graphic methods and spectroscopic techniques were carried out to isolate and characterize the constituents of the extract. At a concentration range of 1-4 mg/ml, the crude extract of Aspergillus sp. showed mild antimicrobial activity against Bacillus subtilis, Klebsiella pneumoniae, and Candida albicans. The fungal extract showed good antioxidant activity at 500 µg/ml, with an inhibition of 72.1%. Also, at 100 µg/ml, the extract showed excellent cytotoxic activity against A2780 (sens) and A2780 (cisR), with growth inhibitions of 105.1% and 105.5% respectively. Two known pharmacologically active phenolic compounds (p-hydroxyphenyl acetic acid and ferulic acid) were isolated from the fermentation extract of the endophytic fungus. At 250 µg/ml, ferulic acid exhibited an excellent antioxidant activity with an inhibition of 90.4%, while an inhibition of 35.4% was recorded for p-hydroxyphenyl acetic acid. Ferulic acid also showed a mild antifungal activity at 500 µg/ml against A. niger with an IZD of 2 mm. p-Hydroxyphenyl acetic acid showed no antimicrobial activity. These results further confirm the potentials of endophytic fungi associated with Nigerian plants as source of bioactive compounds with pharmaceutical or industrial applications. DOI: http://dx.doi.org/10.5281/zenodo.140498

    Beyond ''women's traits'': exploring how gender, social difference and household characteristics influence trait preferences

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    Open Access Journal; Published online: 14 Dec 2021Demand-led breeding strategies are gaining importance in public sector breeding globally. While borrowing approaches from the private sector, public sector programs remain mainly focused on food security and social impact related outcomes. This necessitates information on specific user groups and their preferences to build targeted customer and product profiles for informed breeding decisions. A variety of studies have identified gendered trait preferences, but do not systematically analyze differences related to or interactions of gender with other social dimensions, household characteristics, and geographic factors. This study integrates 1000minds survey trait trade-off analysis with the Rural Household Multi-Indicator Survey to study cassava trait preferences in Nigeria related to a major food product, gari. Results build on earlier research demonstrating that women prioritize food product quality traits while men prioritize agronomic traits. We show that food product quality traits are more important for members from food insecure households and gender differences between men and women increase among the food insecure. Furthermore, respondents from poorer households prioritize traits similar to respondents in non-poor households but there are notable trait differences between men and women in poor households. Women in female headed household prioritized quality traits more than women living with a spouse. Important regional differences in trait preferences were also observed. In the South East region, where household use of cassava is important, and connection to larger markets is less developed, quality traits and in ground storability were prioritized more than in other states. These results reinforce the importance of recognizing social difference and the heterogeneity among men and women, and how individual and household characteristics interact to reveal trait preference variability. This information can inform trait prioritization and guide development of breeding products that have higher social impact, which may ultimately serve the more vulnerable and align with development goals
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