Effect of Coefficient of Thermal Expansion (CTE) Mismatch of Solder Joint Materials in Photovoltaic (PV) Modules Operating in Elevated Temperature Climate on the Joint's Damage

With failure of solder joints (SJs) in photovoltaic (PV) modules constituting over 40% of the total module failures, investigation of SJ's reliability factors is critical. This study employs the Garofalo creep model in ANSYS Finite Element Modelling (FEM) to simulate solder joint damage. Accumulated creep strain energy density is used to quantify damage. PV modules consisting of interconnections formed from different material combinations (silver, copper, aluminum, zinc, tin and brass) are subjected to induced temperature cycles ranging from -40 °C to +85 °C. Results show that zinc-solder-silver joint having the highest CTE mismatch of 19.6 ppm exhibits the greatest damage while silver-solder-silver with no mismatch possesses the least damage

Antimicrobial Susceptibility Profile of Bacterial Pathogens Isolated From Pregnant Women with Asymptomatic Bacteriuria at Tertiary Hospital in Northeastern Nigeria

Asymptomatic urinary tract infection among pregnant women is a common clinical episode that is frequently undiagnosed. A total of 200 clean-catch mid-stream urine (150 pregnant women and 50 non-pregnant women)were examined by microscopy and culture methods. Overall, the  prevalence of asymptomatic bacteriuria was 59.0% (118/200) and was significantly higher among pregnant (63.3%, 95/150) than non-pregnant (46.0%, 23/50) subjects (÷2 = 4.66, df = 1, p = 0.03). Tertiary education (72.6%, OR = 1.45, p = 0.014), third trimester (77.6%, OR = 1.39, p = 0.042), multi-gravidity (79.0%, OR = 1.41, p = 0.0017) and multiparity (75.9%, OR = 1.49, p = 0.03) were factors associated with asymptomatic bacteriuria in studied pregnant subjects. Of the 118 bacterial isolates, Klebsiella spp accounted for 39.8% (47/118), followed by S. aureus 22.9% (27/118), E.coli 19.5% (23/118), Proteus spp 9.3% (11/118) and P. aeruginosa 8.5% (10/118) (p < 0.0001). Antibacterial susceptibility test revealed that all bacterial isolates were susceptible to quinolones (ciprofloxacin, pefloxacin and ofloxacin). In addition to this, S. aureus was also susceptible to erythromycin. However, all bacterial isolates were resistant to readily available antibacterial drugs including augmentin®, cotrimoxazole, penicillin and cephalexin. In conclusion, prevalence of asymptomatic bacteriuria among pregnant women in this study isconsidered to be high and the bacterial isolates were quinolones sensitive and resistant to other commonly used antibacterial drugs. Considering the clinical implications of untreated urinary tract infection, it is therefore advisable that routine urine culture may be adopted as part of antenatal care.Keywords: Asymptomatic bacteriuria, urinary tract infection, antimicrobial susceptibility, tertiary hospita

Plasmid profile of Escherichia coli 0157:H7 from apparently healthy animals

One hundred samples from healthy animals were screened for the presence of enterohaemorrhagic Escherichia coli 0157: H7 and 17 were positive for EHEC 0157:H7 after confirmation using serology kits. Antibiotic susceptibility patterns showed the isolates to be highly susceptible to the various antibiotics screened with a few showing multiple antibiotic resistance. The plasmid profiles revealed that 8/17 (47%) of the animal isolates harboured detectable plasmids ranging in size from 0.564 kb to >23 kb. Key words: Escherichia coli, EHEC, animals, plasmid profile. African Journal of Biotechnology Vol.2(9) 2003: 322-32

Computational Biology and Bioinformatics in Nigeria

Over the past few decades, major advances in the field of molecular biology, coupled with advances in genomic technologies, have led to an explosive growth in the biological data generated by the scientific community. The critical need to process and analyze such a deluge of data and turn it into useful knowledge has caused bioinformatics to gain prominence and importance. Bioinformatics is an interdisciplinary research area that applies techniques, methodologies, and tools in computer and information science to solve biological problems. In Nigeria, bioinformatics has recently played a vital role in the advancement of biological sciences. As a developing country, the importance of bioinformatics is rapidly gaining acceptance, and bioinformatics groups comprised of biologists, computer scientists, and computer engineers are being constituted at Nigerian universities and research institutes. In this article, we present an overview of bioinformatics education and research in Nigeria. We also discuss professional societies and academic and research institutions that play central roles in advancing the discipline in Nigeria. Finally, we propose strategies that can bolster bioinformatics education and support from policy makers in Nigeria, with potential positive implications for other developing countries. © 2014 Fatumo et al.SAF was supported by H3ABioNet NABDA Node, Abuja, Nigeria with NIH Common Fund Award/NHGRI Grant Number U41HG006941 and Genetic Epidemiology Group at Wellcome Trust Sanger Institute.Published versio

Selenium as adjunct to HAART in the management of HIV/Hepatitis B Virus coinfection: A Randomized open label study

Objective: Management of viral hepatitis in patients with HIV disease is quite challenging and  complex. With effective HIV treatment, people with HIV/HBV co-infection are living longer. HBV  epidemiologic surveys showed an inverse association between selenium (Se) level and regional cancer incidence, as well as viral infection. This study assessed effect of selenium as adjunct to HAART in management of HIV/HBV co-infection.Methods: A randomized open label study with participants allocated into three treatment groups: – HAART-only, Se-only and HAART-plus-Se. HIV viral load, HBV viral load, CD4 cell count, and alanine aminotransaminase (ALT), were analyzed at baseline and 18th month, analyzed using SPSS 5 v11. Ethical approval was obtained from Institute’s Ethical Review Board.Results: Sample size was 149 HIV/HBV patients. Rate of HBV clearance was higher among those on HAART-plus-Se at 18th month when compared with rate of clearance among those on HAART-only (p=0.046). CD4 count increment among HAARTplus- Se group compared with HAART-only group was higher (p=0.133), though not statistically significant. On comparison of baseline and 18th month ALT, there was significant decline for HAART-plus-Se (p=0.002) compared with HAART-only group.Conclusion: Selenium seems to have protective effect on liver cells; may be beneficial as adjunct to HAART in HIV/HBV management.Key words: HIV/HBV co-infection, Selenium adjunct, HAAR

World Health Organization Discontinues Its Drinking-Water Guideline for Manganese

Background: The World Health Organization (WHO) released the fourth edition of Guidelines for Drinking-Water Quality in July 2011. In this edition, the 400-µg/L drinking-water guideline for manganese (Mn) was discontinued with the assertion that because “this health-based value is well above concentrations of manganese normally found in drinking water, it is not considered necessary to derive a formal guideline value.

Acanthus montanus: An experimental evaluation of the antimicrobial, anti-inflammatory and immunological properties of a traditional remedy for furuncles

<p>Abstract</p> <p>Background</p> <p><it>Acanthus montanus </it>(Nees) T. Anderson (Acanthaceae) is a shrub widespread in Africa, the Balkans, Romania, Greece and Eastern Mediterranean. It is used in African traditional medicine for the treatment of urogenital infections, urethral pain, endometritis, urinary disease, cystitis, leucorrhoea, aches and pains. In southeastern Nigeria, the root is popular and acclaimed highly effective in the treatment of furuncles. This study was undertaken to experimentally evaluate the antimicrobial and anti-inflammatory properties of the root extract as well as its effect on phagocytosis and specific cell-mediated immune response which may underlie the usefulness of the roots in treatment of furuncles.</p> <p>Methods</p> <p>The aqueous root extract (obtained by hot water maceration of the root powder) was studied for effects on the growth of clinically isolated strains of <it>Pseudomonas aeruginosa </it>and <it>Staphylococcus aureus</it>. The anti-inflammatory activity was investigated using acute topical edema of the mouse ear induced by xylene, acute paw edema induced by agar in rats, formaldehyde arthritis in rats, vascular permeability induced by acetic acid in mice and heat- and hypotonicity-induced haemolysis of ox red blood cells (RBCs). Also evaluated were the effects on <it>in vivo </it>leukocyte migration induced by agar, phagocytic activity of macrophages on <it>Candida albicans </it>and specific cell-mediated immune responses (delayed type hypersensitivity reaction (DTHR) induced by sheep red blood cell (SRBC)). The acute toxicity and lethality (LD₅₀) in mice and phytochemical constituents of the extract were also determined.</p> <p>Results</p> <p>The extract moderately inhibited the growth of the test organisms and significantly (<it>P </it>< 0.05) inhibited (57%) topical acute edema in the mouse ear. It significantly (<it>P </it>< 0.05) suppressed the development of acute edema of the rat paw in a non-dose-related manner and was not effective in inhibiting the global edematous response to formaldehyde arthritis. It also inhibited vascular permeability induced by acetic acid in mice and the haemolysis of ox RBCs induced by heat- and hypotonicity. The extract increased total leukocyte and neutrophil counts and caused a significant (<it>P </it>< 0.05) dose-related increase in the total number of macrophages at the 800 mg/kg dose. On phagocytic activity, the extract evoked a significant (<it>P </it>< 0.05) increase in the number of macrophages with ingested <it>C. albicans </it>at 800 mg/kg dose, and significantly (<it>P </it>< 0.05) inhibited DTHR in a dose-related manner. Phytochemical tests on the extract revealed an abundant presence of alkaloids and carbohydrates while saponins, glycosides, and terpenoids occurred in trace amounts. Acute toxicity test established an oral and intraperitoneal LD₅₀greater than 5,000 mg/kg.</p> <p>Conclusion</p> <p>The effectiveness of the root of <it>A. montanus </it>in the treatment of furuncles may largely derive from mobilization of leukocytes to the site of the infection and activation of phagocytic activity as well as suppression of exacerbated immune responses by its constituents. Antimicrobial and anti-inflammatory activities are likely contributory mechanisms. Phytochemical constituents such as alkaloids and carbohydrates may be responsible for these pharmacological activities.</p

Clinical effects of Garcinia kola in knee osteoarthritis

<p>Abstract</p> <p>Objectives</p> <p>Over the past years, there has been a growing number of knee osteoarthritis (KOA) patients who are not willing to comply with long-term non-steroidal anti-inflammatory drugs (NSAID) treatment and wish to use herbal anti- rheumatic medicine. This study assessed the clinical effects of <it>Garcinia kola </it>(GK) in KOA patients.</p> <p>Patients and methods</p> <p>Prospective randomized, placebo controlled, double blind, clinical trial approved by the institutional medical ethics review board and written informed consent obtained from each patient. All KOA patients presenting at the Obafemi Awolowo University Teaching Hospital complex were recruited into the study. The patients were grouped into four (A = Placebo, B = Naproxen, C = <it>Garcinia kola</it>, D = Celebrex). The drugs and placebo were given twice a day per oral route. Each dose consisted of 200 mg of <it>G. kola</it>, Naproxen (500 mg), Celebrex (200 mg) and Ascorbic acid (100 mg). The primary outcome measure over six weeks study period was the change in mean WOMAC pain visual analogue scales (VAS). Secondary outcome measures included the mean change in joint stiffness and physical function (mobility/walking).</p> <p>Results</p> <p>143 patients were recruited, 84 (58.7%, males – 24, females – 60) satisfied the selection criteria and completed the study. The effect of knee osteoarthritis bilateralism among the subjects was not significant on their outcome (p > 0.05). The change in the mean WOMAC pain VAS after six weeks of <it>G. kola </it>was significantly reduced compared to the placebo (p < 0.001). Multiple comparisons of the mean VAS pain change of <it>G. kola </it>group was not lowered significantly against the naproxen and celebrex groups (p > 0.05). The onset of <it>G. kola </it>symptomatic pain relief was faster than the placebo (p < 0.001). However, it was slower than the active comparators (p > 0.05). The duration of therapeutic effect of <it>Garcinia kola </it>was longer than the placebo (p > 0.001). <it>G. kola </it>period of effect was less than naproxen and celebrex (p < 0.001). <it>G. kola </it>subjects had improved mean change mobility/walking after six weeks better than the control group(p < 0.001). The mean change in mobility of the <it>G. kola </it>group when compared to the active comparators was not significantly better (p < 0.05). The mean change of knee joint stiffness (p < 0.001) and the change of mean WOMAC score (p < 0.001) were improved on <it>Garcinia kola </it>as compared to the placebo. The mid term outcome of eleven <it>Garcinia kola </it>subjects after cessation of use had a mean pain relief period of 17.27 +/- 5.15 days (range: 9–26 days). There was no significant cardiovascular, renal or drug induced adverse reaction to <it>Garcinia kola</it>.</p> <p>Conclusion</p> <p><it>Garcinia kola </it>appeared to have clinically significant analgesic/anti-inflammatory effects in knee osteoarthritis patients. <it>Garcinia kola </it>is a potential osteoarthritis disease activity modifier with good mid term outcome. Further studies are required for standardization of dosages and to determine long-term effects.</p

Sex-specific disruption of murine midbrain astrocytic and dopaminergic developmental trajectories following antenatal GC treatment

The mammalian midbrain dopaminergic systems arising in the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) are critical for coping behaviours and are implicated in neuropsychiatric disorders where early life challenges comprise significant risk factors. Here, we aimed to advance our hypothesis that glucocorticoids (GCs), recognised key players in neurobiological programming, target development within these systems, with a novel focus on the astrocytic population. Mice received antenatal GC treatment (AGT) by including the synthetic GC, dexamethasone, in the mothers' drinking water on gestational days 16-19; controls received normal drinking water. Analyses of regional shapes and volumes of the adult SNc and VTA demonstrated that AGT induced long-term, dose-dependent, structural changes that were accompanied by profound effects on astrocytes (doubling/tripling of numbers and/or density). Additionally, AGT induced long-term changes in the population size and distribution of SNc/VTA dopaminergic neurons, confirming and extending our previous observations made in rats. Furthermore, glial/neuronal structural remodelling was sexually dimorphic and depended on the AGT dose and sub-region of the SNc/VTA. Investigations within the neonatal brain revealed that these long-term organisational effects of AGT depend, at least in part, on targeting perinatal processes that determine astrocyte density and programmed cell death in dopaminergic neurons. Collectively, our characterisation of enduring, AGT-induced, sex-specific cytoarchitectural disturbances suggests novel mechanistic links for the strong association between early environmental challenge (inappropriate exposure to excess GCs) and vulnerability to developing aberrant behaviours in later life, with translational implications for dopamine-associated disorders (such as schizophrenia, ADHD, autism, depression), which typically show a sex bia