Synthesis, characterization and antibacterial studies of metal complexes of sulfadiazine with N-alkyl-N-phenyldithiocarbamate

Co(II), Cu(II), Pd(II) and Pt(II) complexes of 4-amino-N-(2-pyrimidinyl)benzene sulfonamide (sulfadiazine) with some N-alkyl-N-phenyl dithiocarbamate have been synthesized and characterized by elemental analysis, conductivity measurements, UV-Vis and FTIR spectroscopy. The complexes are formulated as four coordinate MN2S2 species in which the metal ions are coordinated to one molecule of sulfadiazine through the pyrimidinyl and sulfulnamido nitrogen atoms and one molecule of dithiocarbamate through two sulfur atoms with both molecules acting as bidentate chelating ligands. The in vitro antibacterial activities of the complexes and sulfadiazine were evaluated against eight bacteria strains using the agar well diffusion method. The metal complexes showed varied antibacterial properties and their minimum inhibitory concentration (MIC) and maximum bactericidal concentration (MBC) were determined. KEY WORDS: Sulfadiane, Dithiocarbamate, Metal complexes, Antibacterial, Drug resistance Bull. Chem. Soc. Ethiop. 2013, 27(1), 77-84.DOI: http://dx.doi.org/10.4314/bcse.v27i1.

Analiza kretanja rasta proizvodnje poljoprivrednih kultura u Nigeriji (1961. –2014.)

This paper focuses on trend analysis of crop productivity growth in Nigeria between 1961 and 2014. It was therefore intended to estimate the effect of different factors of production that influence crop output and to compute their technical efficiency, technological change and total factor productivity change. Panel data was broken into land, labour, tractor, fertilizer and animal power. Descriptive statistics, Cobb-Douglas production analysis and Malmquist Productivity index were the tools employed for the analysis. The result of the trend analysis shows that time has a positive effect on crop production and also shows that there is an increase in crop output, land, labour, tractor, fertilizer and animal power over years. Land and animal power are statistically significant at 1% probability level and a unit increase in land and animal power, crop output increases by 2.176772 tons and 0.7531192 tons respectively, this implies that land and animal power have a positive effect on crop output in Nigeria. Labour and tractor have negative impact on crop output, while fertilizer has no significant effect on crop output. The efficiency change, technical change and total factor productivity change were also analyzed. According to the analysis, Nigeria experienced the highest agricultural productivity from 1992, with value of 1.166. It is therefore recommended that the use of agricultural land should be increased, relevant policies should address the constraints to technology progress, and efficiency should be promoted in order to improve productivity growth.Ovaj je rad usredotočen na analizu kretanja rasta proizvodnje poljoprivrednih kultura u Nigeriji u razdoblju od 1961. do 2014. Cilj je ovog rada odrediti kako različiti faktori proizvodnje utječu na količinu proizvedenih kultura te izmjeriti njihovu tehničku učinkovitost, tehnološki razvoj i promjene u ukupnom faktoru produktivnosti. Panel podaci razdijeljeni su u sljedeće kategorije: zemljište, radna snaga, traktori, gnojivo i životinjska snaga (radne životinje). Za potrebe analize korištena je deskriptivna statistika, Cobb-Douglasova proizvodna funkcija i Malmquistov indeks produktivnosti. Dobiveni rezultati pokazuju da vrijeme ima pozitivan učinak na proizvodnju poljoprivrednih kultura te da je tijekom godina zamjetan porast u količini proizvedenih kultura, zemljištu, radnoj snazi, traktorima, gnojivu i životinjskoj snazi. Zemljište i životinjske snaga statistički su značajne kategorije, s razinom vjerojatnosti od 1 %. Porast jedinice zemljišta rezultira porastom od 2,176.772 tona u poljoprivrednim kulturama, a životinjske snage porastom od 0,7531192 tona u poljoprivrednim kulturama. Iz ovoga proizlazi da zemljište i životinjska snaga imaju pozitivan utjecaj na količinu proizvedenih poljoprivrednih kultura u Nigeriji. Kategorije radne snage i traktora imaju negativan učinak, a gnojiva nemaju nikakav značajni učinak na količinu proizvedenih poljoprivrednih kultura. Mjerena je i tehnička učinkovitost te tehnološki razvoj i promjene u ukupnom faktoru produktivnosti. Prema dobivenim rezultatima, poljoprivredna je proizvodnja u Nigeriji 1992. dosegla svoju najveću vrijednost od 1,166. S obzirom na rezultate preporučuje za povećanje poljoprivrednog zemljišta i učinkovitosti te donošenje relevantnih mjera čiji bi cilj bio rješavanje problematike razvoja tehnologije

Effect of Viscous Dissipation on Natural Convection Flow in a Vertical Parallel-Plate Microchannel with Suction and Injection

This paper investigates the effects of viscous dissipation on the hydrodynamic and thermal behaviour of a fully developed natural convection flow in a vertical parallel–plate microchannel with suction and injection by the Homotopy perturbation method. The velocity slip and temperature jump conditions at the walls are taken into account. The influence of viscous dissipation () on the microchannel hydrodynamic and thermal behaviour was discussed with the aid of graphs. The study reveals that the presence () and variation of viscous dissipation parameter in natural convention flow significantly affects the microfluidic system of infinite length and should not be neglected. Keywords: Natural convection, viscous dissipation, suction and injection

Cu(II), and Zn(II) complexes of (4E)-4

4-dihydroxyphenyl)ethylidene]amino}ethyl)imino]pentan-2-one have been synthesized and characterized by elemental analyses, molar conductance, electronic and IR spectral studies, and XRD. FTIR confirmed the ligand coordinates the metal ion to form mononuclear complex via the oxygen and nitrogen atoms of the phenolic group and azomethine group, respectively. Tetrahedral geometry is proposed for Co(II) complex and square-planar geometry for Ni(II) and Cu(II) complexes. The antibacterial studies of the compounds were determined and they show that the metal complexes are more active than the free ligands. The antioxidant activity by DPPH and ABTS method was examined and it shows Cu(II); IC 50 = 2.31 ± 1.54 M for DPPH and Co(II); IC 50 = 1.83 ± 1.08 M for ABTS were the most active

Radiological Impacts of Natural Radioactivity in Locally Produced Tobacco Products in Ibadan, Oyo State, Nigeria

Radionuclides are found naturally in air, water and soil. They are even found in vegetation, consumer products and in human body. Everyone on the planet is exposed to some background level of ionizing radiation through external exposures that occurs as a result of irradiation, and internal exposures that occurs as a result of ingestion and inhalation. Studies have shown that tobacco contains minute quantities of radioisotopes from uranium and thorium-decay series which are radioactive and carcinogenic. Tobacco product increases both external and internal exposure due to these radioisotopes. In fact, tobacco products have been considered to be one of the most significant causes of lung cancer. Owing to the large-scale consumption of tobacco in Nigeria at the present time, locally produced tobacco products in Nigeria were collected from the market and the naturally-occurring 238U and 232Th decay series, as well as non-series decay 40K in these products were measured using γ-ray spectrometer. The radiological impacts of the radionuclides in these products were assessed from their specific activities. The average values of the absorbed dose rate were 19.72 and 17.59 nGy h-1 for snuff and cigarette products respectively. The average values of the effective doses due to daily inhalation of smoke by consumers from one wrap of snuff and one stick of cigarette products is 592.32 and 66.62 μSv yr-1 respectively. Similarly, the values of the radium equivalent activity index for snuff and cigarette samples were 40.95 and 38.95 Bq kg-1 respectively. Also the external radiation hazard index were 0.12 and 0.11 for snuff and cigarette samples respectively while the internal radiation hazard index were 0.17 and 0.15 for the two samples respectively. The average excess lifetime cancer risk (x 10-3) values for daily inhalation of smoke from one wrap of snuff and one (1) stick of cigarette were 2.07 and 0.23 x 10-3 respectively. The estimated values of some of these parameters were found to be lower than the recommended limit by UNSCEAR (2000). However, the effective dose poses a serious health risk to addicted consumers of the product when three (3) or more wraps of snuff and one (1) or more packs of cigarette products are consumed daily. The mean excess lifetime cancer risks values estimated were also much higher than the recommended limits by UNSCEAR (2000). This then makes the risk of suffering cancer and other radiation injuries to be high.Keywords: Radiological impacts, Tobacco, Cigarette, Snuff, Cancer, Radiation injury, Nigeria

Biochemical Properties, In-Vitro Antimicrobial, and Free Radical Scavenging Activities of the Leaves of Annona muricata

Fifteen (15) male Wistar rats were completely randomized into three (3) groups. Group A was normal control, Group B received 200 mg/kg weight of ethyl acetate extract of Annona muricata leaves (AMLE) and Group C received 100 mg/kg b.weight AMLE. Single daily dose of AMLE was administered orally for twenty one (21) days after which the animals were sacrificed. The blood samples were taken for haematological and biochemical analysis. Antibacterial and antifungal activities of n-hexane, ethyl acetate and methanol extracts of Annona muricata leaves were carried out. These extracts exhibited satisfactory inhibitory activities against bacterial and fungal strains, which include; Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Klebsiellae pneumonae, Candida albicans, Aspergillus niger, penicillium notatum and Rhizopus stolonifer. N-hexane extract of the plant exhibited antioxidant property by scavenging DPPH radicals with IC50 of 342.44 μg/mL. GC-MS analysis of nhexane, ethyl acetate and methanol extracts of the plant principally revealed the presence of Urs-12-ene (23.15%), Squalene (48.80%) and Clionasterol (15.88%) respectively. Keywords: biochemical properties, antimicrobial, antioxidant, urs-12-ene, squalene, clionastero

Assessment of Charcoal Production and Its Impact on Deforestation and Environment in Borgu Local Government Area of Niger State, Nigeria

Commercial charcoal production is gradually becoming one of the major sources of sustenance and currently plays a major role in promoting entrepreneurial development in Borgu Local Government Area of Niger State. The study was carried out to assess charcoal production and its impact on deforestation and environment in the study area. Data for the study were generated from a structured questionnaire administered to charcoal producers in the study area. Data obtained revealed that majority (83%) were male with 56% within the age class of 21-40, majority (67%) were married and about (51%) attained primary education. Majority of the producers (82%) used traditional earth mound kiln method for charcoal production and about 56% of the producers obtained their raw material from free area. Most preferred tree species for charcoal production was Prosopis africana and accounted for 61%. Loss of biodiversity ranked 1st as regards impact of charcoal production on deforestation and environment in the study area, closely followed by forest degradation and soil degradation respectively. This study will enable forestry policy makers, charcoal producers, and farmers in the study area to be better informed about the implications of charcoal production on deforestation and environment and seek innovative means and ways to combat its menace

REVIEW ON ENVIRONMENTAL IMPACT AND VALOURIZATION OF WASTE COOKING OIL

 There is a large volume of waste cooking oil (WCO) in the world, which has made waste management extremely difficult. The main purpose of the large-scale organized collection of WCO is the synthesis of biodiesel. Although alternative applications are equally important and necessitate attention, the majority of studies focus primarily on the synthesis of biodiesel from WCO. The major objective of this review paper is to draw attention to the potential environmental implications of used cooking oil as well as its potential for reuse in products other than biodiesel. It can be transformed into direct-burn energy, biodiesel, hydrogen gas, pyrolytic oil, or hydrogen. Applications like combined heat and power generation (CHP) are where WCO is most useful. Additionally, it can be chemically processed to create biodegradable polyurethane sheets, soaps, alkyd resins, greases, and lubricants. WCO is a carbon source that can be used in fermentation processes to create polyhydroxybutyrate and rhamnolipid biosurfactant after being completely cleaned and sterilized. Therefore, waste cooking oil can be viewed as a waste that can be converted into energy or used as a catalyst for biological or chemical processes

Utjecaj klimatskih promjena na proizvodnju riže u Adamawi, Nigerija

This study analyzes the effect of climate change on rice production in Adamawa State, Nigeria. The study describes the trend in rice production and determines the factors affecting the output of rice in Adamawa. Secondary data from 1990-2015 was used. The analytical tools used were descriptive analysis, unit root and regression analysis. The result of the study reveals that there is variation in the trend of the climatic factors affecting rice production in Adamawa State. The findings reveal that rainfall and minimum temperature are the major climatic factors that affect the rice production; such that 1% increase in rainfall leads to 22.2% increase in rice production and 1% increase in minimum temperature leads to 3.7% reduction in rice production. Therefore rainfall is found to be positively significant to rice output, while minimum temperature is found to be negatively significant. The study therefore recommends that irrigation facilities should be built, especially in the north where drought threatens food production. Also breeders should develop rice varieties that have less gestation period and can survive high temperature.Ovaj se rad bavi utjecajem klimatskih promjena na proizvodnju riže u Adamawi, Nigerija. Opisuju se trendovi rasta i pada proizvodnje te određuju faktori koji utječu na količinu proizvedene riže. Istraživanje se temelji na sekundarnim podacima iz razdoblja od 1990. do 2015. Za analizu su korištene sljedeće metode: deskriptivna analiza, test jediničnog korijena i regresijska analiza. Rezultati dobiveni istraživanjem pokazuju da klimatski faktori utječu na proizvodnju riže u Adamawi, a kao glavni među njima ističu se količina padalina i minimalna temperatura: porast u količini padalina od 1 % rezultira porastom u proizvodnji riže od 22.2 %, a porast minimalne temperature od 1 % rezultira padom u proizvodnji riže od 3.7 %. Iz toga se može zaključiti da postoji pozitivna korelacija između količine padalina i količine proizvedene križe te negativna korelacija s obzirom na minimalnu temperaturu. S obzirom na dobivene rezultate preporučuje se izgradnja objekata za navodnjavanje, osobito na sjeveru gdje su sušna razdoblja prijetnja proizvodnji hrane. Također, uzgajivačima se preporuča razvoj vrsta riže koje imaju kraći gestacijski period te mogu preživjeti više temperature

ASSESSMENT OF PHYSIOLOGICAL AND ELECTROCHEMICAL EFFECTS OF A REPURPOSED ZINC DITHIOCARBAMATE COMPLEX ON ACINETOBACTER BAUMANNII BIOFILMS

Acinetobacter baumannii is an infectious agent of global proportion and concern, partly due to its proficiency in development of antibiotic resistance phenotypes and biofilm formation. Dithiocarbamates (DTC) have been identified as possible alternatives to the current antimicrobials. We report here the evaluation of several DTC-metal complexes against A. baumannii planktonic cells and biofilms. Among the DTC-metal complexes and DTCs tested, ZnL1 (N-methyl-1-phenyldithiocarbamato-S,S′ Zn(II)), originally designed as an antitumor agent, is effective against biofilm forming A. baumannii. A MIC value of 12.5 µM, comparable to that of Gentamicin (5 µM) was measured for planktonic cells in tryptic soy broth. Spectroscopy, microscopy and biochemical analyses reveal cell membrane degradation and leakage after treatment with ZnL1. Bioelectrochemical analyses show that ZnL1 reduces biofilm formation and decreases extracellular respiration of pre-formed biofilms, as corroborated by microscopic analyses. Due to the affinity of Zn to cells and the metal chelating nature of L1 ligand, we hypothesize ZnL1 could alter metalloprotein functions in the membranes of A. baumannii cells, leading to altered redox balance. Results indicate that the DTC-Zn metal complex is an effective antimicrobial agent against early A. baumannii biofilms under laboratory conditions