519 research outputs found
Sythesis, Physico-Chemical and Antimicrobial Evaluation of Cu(II), Fe(II), Mn(II) Complexes with Schiff Base Derived from N-(2- hydroxybenzylidene)-3-(benzylideneamino)benzenesulfonamide
A Schiff-base derived from N-(2-hydroxybenzylidene)-3-(benzylideneamino)benzene sulfonamide, and its metal complexes of Cu(II), Fe(II) and Mn(II) were synthesized and characterized based on their melting point decomposition temperature, solubility, molar conductance, magnetic moment and infrared analyses. Jobâs method of continuous variation revealed that all the metal complexes are in 1:1 Metal-Ligand ratio. Physical and analytical data suggested that the Schiff base act as tretradentate ligand towards metal ion via azomethine-N, deprotonated phenolic-O and S=O group of sulphanilamine. All the complexes have low molar conductance value (11.28-66.8Ί-1cm2mol-1), indicating that they are non-electrolyte. The magnetic moment values ranges from1.74 to 5.98B.M shows that all the complexes are paramagnetic in nature. The synthesized ligand and its respective metal complexes were screened for their antibacterial activity against Staphylococcus aureus (Grampositive), Escherichia coli, (Gram-negative) bacterial strains and antifungal activity against Mucor inducus spp and Aspergillus fumigatus. The results of these studies revealed that the Schiff base and its metal complexes showed significant antibacterial and antifungal activity at high concentrations
Synthesis, characterization and antimicrobial studies of Cu(II) and Zn(II) complexes with the Schiff base N-salicylidene-4-chloroaniline
Transition Metal Complexes of Cu(II) and Zn(II) with Schiff base N-salicylidene-4-chloroaniline were synthesized and characterized by solubility test, infrared spectra, conductivity measurement, magnetic susceptibility, metal-ligand ratio determination, and antimicrobial activity. The low molar conductance values range (16.-27Ohm-1cm2mol-1) indicated that all the complexes are non-electrolytes. The magnetic susceptibility revealed that the Cu(II) complex is paramagnetic while Zn(II) complex is diamagnetic. The metal-ligand ratio was found to be 1:2 in all the complexes. The infrared spectra suggested that the Schiff base behaves as a bidentate ligand. The Schiff base and its metal complexes were tested for antibacterial activity using Staphylococcus aureus and Escherichia coli and fungal activity using Aspergillus flavus and Mucor species. The results of the tests indicated moderate antimicrobial activity against the tested organism when compared with the standards (Ciprofloxacin and Ketoconazole), and this activity increases by increasing concentration. The Metal Complexes showed higher activity than free Ligand due to chelation.Keywords: Salicylaldehyde, 4-chloroaniline, Schiff base, Complexes, antimicrobial activit
Assessment of Reliability and Availability of Series-Parallel Sub-Systems
The paper presents the explicit expressions for measuring reliability parameter of systems, Graphs were plotted to highlight important results. Results have shown that measures of system effectiveness such MTSF, system availability and profit increases with repair rates and decreases with failure rates.The developed model helps in determining the optimal maintenance strategies which ensure the maximum overall availability of the system. The optimum values of failure and repair rates for each subsystem were given. It is observed that the first subsystem is having the maximum availability with (97%). The optimum values of failure and repair rates for maximum availability level for each subsystem is also shown. Keywords: Mean time to system failure, Availability, Reliability, Maintenance and Subsystem
Genetic studies of agronomic and kernel quality traits in white maize (Zea mays L.) inbred lines
Field experiments were conducted at National Horticultural Research Institute, Bagauda (11°33´N; 8°23´E) in the Sudan Savannah and Institute for Agricultural Research, Samaru (11011´N; 07038âE) in the Northern Guinea Savanna ecological zones of Nigeria. The experiments were conducted between July-October, 2014 rainy season to estimates mean squares for general combining ability (GCA), specific combining ability( SCA) and interaction between general combining ability and location (GCA x location) and specific combining ability and location Interactions ( SCA x location) for agronomic traits and kernel quality traits. The study comprised of 15 hybrid lines, 6 parental lines along with 4 checks which were laid out in partially balanced lattice design with three replications. Analysis of variance revealed significant (P⤠0.01) GCA for days to maturity (27.74), ear length (8.85cm) , ear diameter (22.25cm), plant height (1501.60cm), field weight (1.70kg), moisture content at harvest (16.48%) and yield (10947553.16 kgha-1) indicating the additive gene action contributing the expression of these traits. The mean squares due to SCA were highly significant (P⤠0.01) for days to maturity (7.49), ear length (10.06cm), ear diameter (26.96cm) and moisture content at harvest (6.78%) indicating the preponderance of non-additive gene action in the expression of these traits. The mean squares for GCAĂ location and SCAĂ location were not significant for all traits except percent whole kernel which shows highly significant GCA Ă location interaction (2077.97%) and this indicated that, different parental genotypes behaved differently with respect to this trait under different location.Keywords: Agronomic traits, Genetic, General Combining Ability, Inbred lines, Kernel Quality and Specific Combining Abilit
Growth performance, carcass and organ characteristics of growing rabbits fed graded levels of Moringa oleifera leaf meal in diets
An experiment was conducted at the Department of Animal Science teaching and research farm, Bayero University Kano, to evaluate the effect of feeding graded levels of Moringa oleifera leaf meal (MOLM) in diets on growth performance, carcass and organ characteristics of weaned rabbits. Twenty eight grower rabbits of averagely 975g in weight were allotted into four treatments of seven rabbits each in a completely randomize design. Four isonitrogenous diets (16% CP) were formulated in which MOLM was included at 0, 15, 30 and 45% for treatments 1, 2, 3 and 4 respectively. The diets were fed to the animals for eight weeks. The result showed that daily weight gain (5.95-13.39g/day) and carcass weight (497.70-727.65g) increased (P<0.05) with increasing levels of MOLM in diets, but dressing percentage (42.49-45.96%) was not affected by dietary treatments. Similarly, the weight of liver (40.35-57.05g), lungs (10.22-11.24g), heart (2.95-4.10g), kidney (8.30-10.70g), kidney fat (11.10-12.65g), small intestine (81.25-99.80g), large intestine (102.45-117.95g), caecum (20.50- 30.50g), stomach (90.75-114.65g), spleen (1.00-1.80g) and abdominal fat (7.89-11.25g) characteristics were not different across the treatments. The results indicate that weaned rabbits can utilize Moringa oleifera leaf meal at up to 45% level of inclusion in diets without any deleterious effects on growth performance, carcass yield and organ characteristics.Key words: Carcass yield, growth, Moringa oleifera, organ characteristics, rabbit
Microorganisms associated with the production of volatile compounds in spoilt tomatoes
The microorganisms associated with the production of volatile compounds in spoilt tomatoes has been isolated and identified. The mean heterotrophic bacterial count recorded range between 8.7 x 106 to 9.1 x 106 cfu/g. The highest value was obtained from Bado and the least from Dundaye market. The organisms isolated and identifiedĂâĂ include three species of bacteria and four fungal species. These include Bacillus, Listeria, Morganella, Aspergillus, Absidia, and Fusarium. GC-MS analysis revealed the presence of eightĂâĂ compounds dominated by 9, 12 Ă¢ââââŹĹ octadecadienoic acid (31.08%), 2, 3 Ă¢ââââŹĹ Butandiol (28.79%), and n-Hexadecanoic acid (19.85%). This studyĂâĂ suggests that spoilt tomatoes could be exploited for the biogeneration of some volatile compounds that could provide baseline knowledge for curbing post harvest lost
pH-Sensitive nanoparticles containing 5-fluorouracil and leucovorin as an improved anti-cancer option for colon cancer
Parenteral administration of chemotherapeutic drugs, 5-fluorouracil (5-FU) and leucovorin (LV), is commonly used to treat large bowel carcinomas such as colon cancer (CC) and colorectal carcinoma (CRC). Our study aims to design a novel nanoparticulate drug-delivery vehicle for oral use capable of colon-specific release. A modified double-emulsion solvent evaporation method was used in the preparation of pH-responsive Eudargit S100 polymeric nanoparticles, loaded with 5-FU/LV combination (5-FU/LV-loaded Eudargit S100 NPs). Our optimized drug-loaded NP showed a pH-responsive drug release and exhibited significantly more cytotoxic actions in cancer-cell lines than free drugs. These findings open the way for conducting clinical trials for colon malignancies treated with nanoparticles
Relationship between serum level of ionized calcium, magnesium, phosphate, vitamin d and parathyroid hormone with stages of CKD.
Chronic kidney disease is defined as either damage or a decreased Glomerular Filtration Rate of less than 60ml/min/1.73m for 3 or more months. There is destruction of renal mass with irreversible sclerosis and loss of nephron leading to a progressive decline in GFR.Secondary hyperparathyroidism hyperphosphataemia, hypocalcaemia and vitamin-D deficiency are common complications of CKD. Objective: To determine relationship between serum level of ionised calcium, magnesium, phosphate, vitamin-D and parathyroid hormone with stages of CKD. Method: This study was conducted at ABUTH Zaria. 125 consecutive adult patients in various stages of CKD who presented were enrolled and 125 apparently healthy matched for sex and age controls were also recruited. Results: 9% of patients were in stage-1, 16% in stage-2, 22% in stage-3, 12% in stage-4 and 41% in stage-5. Serum ionised calcium, vitamin-D and eCrCl showed a progressive decline as the stage of CKD advances, while serum phosphate, creatinine and iPTH showed a progressive increase as the stage of CKD advances. Changes in serum magnesium showed a slight change with advancing stages of CKD. The difference in mean serum levels of calcium, phosphorus, vitamin-D, parathyroid hormone, creatinine and eCrCl with different stages of CKD were statistically significant. eCrCl correlated negatively with phosphate and iPTH while serum creatinine correlated negatively with calcium and positively with phosphate and iPTH. Conclusion: Majority of CKD patients were in late stage. Correlation of analytes with stages was more in late stages and biochemical derangements occurred in late, rather than early stages of CKD
Pembelajaran berasaskan masalah dalam sains: satu meta analisis
Pembelajaran berasaskan masalah (PBM) merupakan salah satu pendekatan pembelajaran konstruktivis (Alias & Saleh, 2007) yang menekankan penglibatan pelajar secara aktif sepanjang proses pembelajaran (Yeung, 2010) manakala guru bertindak sebagai fasilitator dalam membimbing pelajar mencapai objektif pembelajaran dan pengajaran (PdP) yang telah ditetapkan. Pendekatan pembelajaran ini menggunakan masalah berasaskan kepada situasi sebenar (real-world), bersifat kompleks (Wirkala & Kuhn, 2011), tidak berstruktur (Savin-Baden & Kay, 2006) dan tiada penyelesaian yang spesifik (Hmelo-Silver, 2004) bagi merangsang pelajar mengaplikasikan kemahiran berfikir aras tinggi seperti pemikiran kritis dan kemahiran penyelesaian masalah (Rissi, 2010; Sungur, Tekkay & Geban, 2006). Berbeza dengan pendekatan pembelajaran konvensional yang menekankan pembelajaran berbentuk hafalan, pendekatan PBM merangsang minda pelajar dengan cara mengemukakan masalah pada awal sesi pembelajaran (Hung, 2009). Masalah tersebut akan mecetuskan konflik di dalam minda pelajar seterusnya meningkatkan perasaan ingin tahu serta mendorong pelajar berusaha dalam mencari penyelesaian kepada masalah yang diberi
Mathematical Modelling of Dynamics of HIV Transmission Depicting the Importance of Counseling and Treatment
Human immunodeficiency virus is an incurable disease which attacks and destroys the human immunesystem thereby making the body susceptible to all kinds of illnesses. If left unattended to, it can lead to the damaging ofbody organs such as the brain, kidney and the heart which can result to death. Unfortunately this disease has no knowncure till date but through counseling and administering of antiretroviral drugs, the likelihood of dying from it becomesminimal. This study presents the deterministic HIV transmission model. The model has a unique endemic equilibrium point which is locally asymptotically stable if R0 > 1 , DFE of the model was obtained and is shown to be Localasymptotically stable when the associated basic reproduction number was R > 1. We established the numerical simulation of the model which shows that the effective use of condom, counseling or the use of anti-retrovirus drug can lead to effective reduction on HIV transmission. Finally, we discussed that the ART treatment rate will reduce the basic reproduction number R0 hence, leading to the extinction of HIV/AIDS
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