945 research outputs found

    Resources for Chemistry Teaching in Secondary Schools in Akwa Ibom State, Nigeria

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    This study investigated the status of human and material resources for effective implementation of the new chemistry curriculum for secondary schools in Nigeria in Akwa Ibom state. To achieve the objectives of the study, two research questions were raised. Ex-post-facto design was used. The sample consisted of 105 chemistry teachers from all the 31 local government areas of the state using criterion sampling technique. A researcher-developed questionnaire, Resources for Chemistry Teaching Questionnaire (RCTQ), with a reliability index of 0.83 determined using Cronbach’s alpha reliability formula, was used in collecting relevant data. The results of data analyses using percentage rating showed that available human resources are not equitably distributed; the basic facilities are either lacking or are grossly inadequate; and the basic chemicals and equipment for students’ activities are either lacking or are grossly inadequate. Consequently, it was been recommended that the state government should urgent steps to ensure successful implementation of the new curriculum in the state

    In-Vitro Effect of some Commonly Found Botanicals on the Growth and Sporulation of Choanephora Cucurbitarum (Berkeley and Ravenel)

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    A soft rot infection of Abelmoschus esculentus, Amaranthus hybridus and Vigna unguiculata was observed in home gardens and Government farms in the 2010 cropping season. This disease caused remarkable yield loss in these crops. Due to residual effects of synthetic chemical control, it became necessary to test the potency of some botanicals on the growth and  sporulation of the fungus as a control measure.  The  procedures involved isolation and identification of the fungus and potency trials of aqueous and ethanolic extracts of the  botanicals on the assay fungus. The isolated fungus was confirmed  as Choanephora cucurbitarum. The extracts were obtained from Zingiber officinale Roscoe, Gmelina arborea Roxb, Chromolaena odorata Linnaeus and Azadirachta indica A. Juss. Different concentrations of the extracts (0%, 10%, 20%, 30%, 40% and 50%) were used. With ethanol extract, there was complete inhibition of growth by all plant extracts and at all concentrations;  and a little growth in aqueous extracts with Azadirachta indica showing the highest inhibitory effect, while C. odorata showed the lowest inhibitory effect on the first day, (A. indica, 0.1 ± 0.0 ≥ G. arborea, 0.1 ± 0.0 ˃ Z. officinale, 0.2 ± 0.0 ˃ C. odorata, 0.3 ± 0.0). On the last day, the level of inhibition was as follows A. indica, 0.4 ± 0.0 ˃ G. arborea, 0.6 ± 0.0 ˃ Z. officinale, 0.7 ± 0.0 ≥ C. odorata 0.7 ± 0.0. The inhibitory effect increased with increase in the percentage concentration of the extracts. The  potency  was also due in part to the phytochemical constituents of the plant extracts which was observed from the screening test that Saponins, Tannins, Alkaloids, Cardiac glycosides, Flavonoids, Reducing Compounds, Polyphenol, Phlobatannins, Anthraquinones and Hydroxymethyl anthraquinones were either present or absent. Ke words: Botanicals, Cross-River, Phytochemicals, Extract, Susceptibility.

    Extract of Ginger (Zingiber Officinale) on the Histology of the Spleen Using Adult Male Rats

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    Usage of botanical medicine is ancient and plant chemicals are still the backbone of our pharmacopoeia because more than 50% of drugs used in Western pharmacopoeia are isolated from herbs or derived from modification of chemicals first found in plants. Zingiber officinale is one of the most widely used herbs and food flavouring agent and commonly known as ginger. This study was done to evaluate the possible histological effect(s) of ethanolic extract of Zingiber offinale on the liver of adult male albino rats. Twenty five (25) adult wistar rats weighing between 125-200g were divided into five groups of five (5) rats each. Group C, D and E served as experimental groups while group A and B served as the control groups. Group C was administered a dose of 100mg/kg of the extract, group D was given oral dose of 250mg/kg of the extract while group E was given oral dose of 500mg/kg of Zingiber officinale extract. Administration of extract lasted for fourteen days at the end of which the animals were sacrificed using chloroform-inhalation method. The spleen was harvested as tissue samples from sacrificed animals for pathological examination using routine histological procedure and stained with the haematoxylin and eosin stains. Histological examinations of spleen showed that after treatment with low and medium doses (100, 250mg/kg) the ginger extract produced little damaging effects on the spleen histology, indicating moderate lymphoid hyperplasia in the splenic cells. But at higher dosage (500mg/kg), reactive lymphoid hyperplasia in the splenic cells was extensive. Therefore, Zingerber officinale should be used with caution because it may have harmful effects on the spleen cells at high doses. Keywords: Ginger, Histology, Ethanolic extract, Spleen, Wistar rat

    Dipole-field-assisted charge extraction in metal-perovskite-metal back-contact solar cells

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    Hybrid organic-inorganic halide perovskites are low-cost solution-processable solar cell materials with photovoltaic properties that rival those of crystalline silicon. The perovskite films are typically sandwiched between thin layers of hole and electron transport materials, which efficiently extract photogenerated charges. This affords high-energy conversion efficiencies but results in significant performance and fabrication challenges. Herein we present a simple charge transport layer-free perovskite solar cell (PSC), comprising only a perovskite layer with two interdigitated gold back-contacts. Charge extraction is achieved via self-assembled molecular monolayers (SAMs) and their associated dipole fields at the metal/perovskite interface. Photovoltages of approximately 600 mV generated by SAM-modified PSCs are equivalent to the built-in potential generated by individual dipole layers. Efficient charge extraction results in photocurrents of up to 12.1 mA/cm2 under simulated sunlight, despite a large electrode spacing.Comment: 18 pages, 5 figure

    In Silico Approaches and the Role of Ontologies in Aging Research

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    The 2013 Rostock Symposium on Systems Biology and Bioinformatics in Aging Research was again dedicated to dissecting the aging process using in silico means. A particular focus was on ontologies, as these are a key technology to systematically integrate heterogeneous information about the aging process. Related topics were databases and data integration. Other talks tackled modeling issues and applications, the latter including talks focussed on marker development and cellular stress as well as on diseases, in particular on diseases of kidney and skin

    Assessment of peripheral arterial disease in diabetic adults with foot ulcers in an African population

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    Background: Peripheral arterial disease (PAD) is a recognized risk factor for diabetic foot ulceration. It was thought that PAD is not common in Sub-Saharan Africa. Studies show otherwise. It becomes necessary to assess the prevalence of PAD among diabetic adults with foot ulcers in Nigeria. The objective of the study was to assess the prevalence of PAD in diabetic subjects with foot ulcers in Nigeria.Methods: Diagnosis of PAD was made with the ankle-brachial index (ABI). Edinburgh claudication questionnaire was administered to the patients. An ABI of <0.9 is diagnostic of PAD. Risk factors for PAD were assessed. A control group of non-diabetic adults was used.Results: Sixty-seven per cent (67%) of the test group has PAD as compared to 18% of the control group. Smoking, duration of diabetes and systemic hypertension were strongly associated with PAD.Conclusions: Diabetic adults with foot ulcers in Nigeria have a high prevalence of PAD

    Comparison of serum levels of calcium and magnesium among preeclamptic and normotensive pregnant women at Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria

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    Background:Despite numerous studies, the exact aetiology of pre-eclampsia remains unknown. Some studies have shown that supplementation of calcium and magnesium could ameliorate the effects of pre-eclampsia. The objective of this study was to compare the calcium and magnesium levels in the serum of Nigerian women with or without pre-eclampsia.Methods:In this study, serum calcium and magnesium levels were determined using atomic absorption spectrometry in 54 patients and 48 healthy normotensive pregnant women. The mean, standard deviation, Student’s‘t’ test and Pearson correlation were employed.Results:Serum calcium was significantly lower in patients than controls (9.17 ± 0.6 vs. 7.22 ± 0.5 mg/dl. P <0.001) (t test). Plasma Magnesium was significantly lower in patients than controls 13.19 ± 1.1 vs. 9.81 ± 0.7 mg/dl. P <0.001). The systolic and diastolic blood pressure showed significant inverse correlation with both calcium and magnesium (P<0.01).Conclusion:There was significant reduction in the levels of calcium and magnesium in patients with pre-eclampsia. Dietary supplementation of these trace elements may help to prevent pre-eclampsia

    Bacterial Isolates and Antibiotic Sensitivity among Gambian Children with Severe Acute Malnutrition

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    Background. Establishing the pattern of infection and antimicrobial sensitivities in the local environment is critical to rational use of antibiotics and the development of management algorithms. Methods. Morbidity history and physical examination of 140 children with severe acute malnutrition were recorded. Their blood, stool, and urine samples were cultured and antibiotic sensitivity patterns determined for any bacterial pathogens isolated. Results. Thirty-eight children had a pathogen isolated from blood culture, 60% of which were considered contaminants. Coagulase negative staphylococcus was the predominant contaminant, while the major causes of bacteraemia were nontyphoidal Salmonella (13%), S. pneumoniae (10%), and E. coli (8%). E. coli accounted for 58% of the urinary isolates. No pathogen was isolated from stool. In vitro sensitivity by disk diffusion showed that 87.5% of the isolates were sensitive to ampicillin and/or gentamicin and 84.4% (27/32) to penicillin and/or gentamicin. Conclusions. A combination of ampicillin and gentamicin provides adequate antibiotic cover for severely malnourished children in The Gambia

    Effect of moderate - vigorous intensity physical exercise on female sex hormones in premenopausal university students in Nnewi, Nigeria

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    Background: Sedentary lifestyle and diseases associated with it is on the increase in our communities, state and country as a whole. The objective was to determine the effect of exercise on ovarian reserve status of the participants using day 3 FSH, LH and estrogen values and the ovulatory status of the participants using day 21 progesterone values. Methods: The study was a prospective comparative study. A total of 30 participants were recruited for this work. They were divided into 2 groups: 15 subjects that did exercise for 1 month and 15 controls that didn’t do any form of exercise. Baseline blood samples were collected from the two groups on day 3 and day 21 of the menstrual cycle. The subjects started exercise on day 1 of the next menstrual cycle. Blood samples were collected from the subjects and control on day 3 and day 21 of the next menstrual cycle. Results:There was significant reduction in weight and therefore BMI of the study group compared to control group and study group baseline after one month of exercise (P<0.05). There were no significant differences in the baseline levels of Estrogen, FSH, LH and progesterone between the subjects and control groups before the exercise, but after 1 month of exercise, there were significant differences in the levels of estrogen, FSH, LH and progesterone in these groups (P<0.01). Among the study group there were significant differences in the baseline and final levels of Estrogen, FSH, LH and Progesterone (P<0.01). Conclusions: The hormonal pattern shows that moderate-vigorous exercise may increase the responsiveness and sensitivity of the follicles to FSH and LH with attendant increase in ovulatory status of young females.
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