University of Nigeria
  • Nsukka, Enugu State, Nigeria
Recent publications
Objectives: This study investigated the impact of rohypnol on gastric tissue integrity.Methods: Forty male Wistar rats were randomized into control, low dose rohypnol-treated, high dose rohypnol-treated, low dose rohypnol-treated recovery and high dose rohypnol-treated recovery groups.Results: Rohypnol caused significant rise in gastric malondialdehyde (MDA), oxidized glutathione (GSSG), nitric oxide (NO), tumour necrotic factor-α (TNF-α), and interleukin-6 (IL-6) levels. Also, rohypnol caused reductions in gastric reduced glutathione (GSH) (as well as GSH/GSSG), and activities of superoxide dismutase (SOD), catalase, glutathione-S-transferase (GST), glutathione peroxidase (GPx), cyclo-oxygenase (COX-2). Furthermore, rohypnol upregulated caspase 3 activity and induced gastric DNA damage, evident by a rise in 8-hydroxydeoxyguanosine (8-OHdG) and DNA fragmentation index (DFI) in gastric tissue. These alterations were coupled with reduced gastric weight and distorted gastric cytoarchitecture. Cessation of rohypnol caused a significant but not complete reversal of rohypnol-induced gastric damage.Conclusion: This study revealed that rohypnol induced gastric injury by suppressing glutathione content and COX-2 activity, and upregulating caspase 3-dependent apoptosis, which was partly reversed by rohypnol withdrawal.
The breakout of the COVID-19 pandemic, which has resulted in the shutting down of schools globally, has made a virtual classroom urgently imperative to support the physical classroom. This move cannot be realistic if the level of awareness and proficiency of the stakeholders, as well as challenges faced, are not noted. Hence, this study examined the awareness, proficiency, and challenges of English as a second language (ESL) lecturers in the use of emerging technologies in the post-Covid-19 era as well as the availability of the emerging technologies. The study adopted a survey research design. Three purposes of the study, three research questions, and four hypotheses were formulated to guide the study. The participants of the study comprised all ESL lecturers at the University of Nigeria, Nsukka and its affiliate, Alvan Ikoku Federal College of Education, Owerri. A 37-item structured questionnaire and a structured interview were used for data collection. The data collected were analyzed using mean, standard deviation, t-test and content analysis. The study found, among other things, that there is a significant difference between male and female English language lecturers’ proficiency level in the use of emerging technologies for teaching in the post-Covid-19 era. The study makes a significant contribution to other studies on the use of emerging technologies with respect to gender and age.
The enhanced distributed channel access (EDCA) protocol is a supplement to IEEE 802.11 medium access control (MAC), ratified by IEEE 802.11e task group to support quality of service (QoS) requirements of both data and real-time applications. Previous research show that it supports priority scheme for multimedia traffic but strict QoS is not guaranteed. This can be attributed to inappropriate tuning of the medium access parameters. Thus, an in-depth analysis of the EDCA protocol and ways of tuning medium access parameters to improve QoS requirements for multimedia traffic is presented in this work. An EDCA model was developed and simulated using MATLAB to assess the effect of differentiating contention window (CW) and arbitration inter-frame space (AIFS) of different traffic on QoS parameters. The optimal performance, delay, and maximum sustainable throughput for each traffic type were computed under saturation load. Insight shows that traffic with higher priority values acquired most of the available channels and starved traffic with lower priority values. The AIFS has more influence on the QoS of EDCA protocol. It was also observed that small CW values generate higher packet drops and collision rate probability. Thus, EDCA protocol provides mechanism for service differentiation which strongly depends on channel access parameters: CW sizes and AIFS.
Background Starches have been shown to be important across various disciplines such as the pharmaceutical industries, food industries and also paper industries. Starch is basically a mixture of polymers consisting of α- d -glucose as the monomeric unit. The goal of this study is to modify the native starches which were obtained from Zea mays , Triticumestivum and Oriza sativa through cross-linking (using sucrose and formaldehyde at different concentrations) and also to assess the utilizability of the modified starches as potential excipients [binder] for tableting of paracetamol. Results Maize and rice starches cross-linked with 2.5% sucrose gave the least percentage moisture content. The batches cross-linked with 40% formaldehyde showed the highest moisture content. The densities (bulk and tapped) of maize wheat and rice starches showed a reduction with the increasing concentration of the cross-linking agent for sucrose, which is the reverse case for formaldehyde. The different concentrations of sucrose and formaldehyde cross-maize, wheat and rice starches had pH values between 4.50 and 5.52. The onset and end set of the glass transition temperatures were varied for all the starches modified with formaldehyde. The melting peak temperatures obtained indicated that the formaldehyde-modified rice starch had significantly lower melting temperature than those of wheat and maize starches. Conclusions This study reveals that various concentrations of sucrose and formaldehyde had some influence on the properties of the native starches and resulted in the production of new starch motifs with improved or new functionalities suitable for use as drug excipients in tableting.
Purpose Alkaline-fermented foods (AFFs) play an essential role in the diet of millions of Africans particularly in the fight against hidden hunger. Among AFFs, soumbala is a very popular condiment in Burkina Faso, available and affordable, rich in macronutrients (proteins, lipids, carbohydrates, essential amino acids, and fatty acids), micronutriments (minerals, B group vitamins), and fibers. Bacillus spp. are known to be the predominant microbial species in AFFs and thus have elicited enhanced interest as starter cultures or probiotics. However, few data exist on identification and safety attributes of relevant Bacillus species from African AFFs, particularly from Burkinabe soumbala. Methods This study aimed to genotypically characterize 20 Bacillus strains previously isolated from soumbala , using PCR and sequencing of the 16S rRNA genes, and to evaluate their safety attributes. Results Phylogenetic analysis revealed that the strains were most closely related by decreasing numbers to B. cereus , B. subtilis , Bacillus sp., B. tropicus , B. toyonensis , B. nealsonii , B. amyloliquefaciens , Brevibacillus parabrevis , and B. altitudinis . Among the isolates, 10 were β-hemolytic and 6 were γ-hemolytic while 4 were of indeterminate hemolysis. The 6 γ-hemolytic (presumptively non-pathogenic) strains were susceptible to all tested antibiotics except bacitracin. Strains F20, and F21 were the most sensitive to imipenem (38.04 ± 1.73 mm and 38.80 ± 1.57 mm, respectively) while strain B54 showed the weakest sensitivity to bacitracin (11.00 ± 0.63 mm) with high significant differences ( p < 0.0001). Conclusion The findings highlight identification and safety quality of Bacillus strains which could be further characterized as probiotic-starter cultures for high-quality soumbala production.
Background Antibiotic resistance is on the rise, and new antibiotic research has slowed in recent years, necessitating the discovery of possibly novel microbial resources capable of producing bioactive compounds. Microbial infections are gaining resistance to existing antibiotics, emphasizing the need for novel medicinal molecules to be discovered as soon as possible. Because the possibilities of isolating undiscovered actinomycetes strains have decreased, the quest for novel products has shifted to rare actinomycetes genera from regular environments or the identification of new species identified in unusual habitats. Main body of the abstract The non-streptomyces actinobacteria are known as rare actinomycetes that are extremely difficult to cultivate. Rare actinomycetes are known to produce a variety of secondary metabolites with varying medicinal value. In this review, we reported the diversity of rare actinomycetes in several habitat including soil, plants, aquatic environment, caves, insects and extreme environments. We also reported some isolation methods to easily recover rare Actinobacteria from various sources guided with some procedures to identify the rare Actinobacteria isolates. Finally, we reported the biosynthetic potential of rare actinomycetes and its role in the production of unique secondary metabolites that could be used in medicine, agriculture, and industry. These microbial resources will be of interest to humanity, as antibiotics, insecticides, anticancer, antioxidants, to mention but a few. Short conclusion Rare actinomycetes are increasingly being investigated for new medicinal compounds that could help to address existing human health challenges such as newly emerging infectious illnesses, antibiotic resistance, and metabolic disorders. The bioactive secondary metabolites from uncommon actinomycetes are the subject of this review, which focuses on their diversity in different habitats, isolation, identification and biosynthetic potentials.
Titanium–molybdenum-based alloys are widely used as an orthodontic arch wire for performing an orthodontic mechanotherapy. However, the poor tribological behaviour of titanium-based alloys, in terms of high and unstable friction, severe adhesive wear; low resistance to abrasion has become a major setback. Herein, Ti94Mo6Xn(x = Nb, Ta, Zr and Sn) alloys were fabricated by arc melting and the effect of Nb, Ta, Zr and Sn minor-additions on tribological properties of βtype biomedical Ti-alloys in simulated body fluid (Ringer’s SBF solution) was studied. Additionally, the post-test characteristics, and morphology were studied by XRD, pin-on-disk tester, nano-indentation, 3D confocal microscope and scanning electron microscope (SEM). Results showed that anti-friction resistance rate and the extent of anti-wear resistance improved by up to 40% and 43% with Sn and Nb minor addition, respectively. It was exciting that these functionalised Ti–Mo-based alloys had higher friction and wear resistance than the commonly used Ti–6Al–4 V alloys, which can be beneficial for many biomedical applications.
The G protein-coupled receptor 84 (GPR84) is a putative medium-chain fatty acids (MCFAs) receptor involved in immune regulation and other metabolic processes. Most available studies focused on the GPR84 characterization from mammals, neglecting vital information that could be obtained from other levels of life, such as amphibians, necessary for an apt evolutionary understanding of the orphan GPR84. Hence, this study molecularly characterized and functionally explored the GPR84 from the Chinese Giant Salamander (Andrias davidianus). Therefore, we report that the Chinese Giant Salamander (CGS), one of the world's largest amphibians, expresses a GPR84 protein having 376 amino acids, with about 70% homologous to other amphibians and around 50% to human GPR84. Investigating the relative localized expression of gpr84 mRNA in CGS using quantitative PCR revealed the highest expression in the kidney and liver. Furthermore, four medium-chain fatty acids (MCFAs) at micromolar levels activated CGS-GPR84 transfected and expressed in HEK293 cells. In HEK293 cells, four different concentrations of MCFAs inhibited forskolin-induced cAMP accumulation and resulted in a dose-dependent increase in extracellular signal-regulated kinases 1 and 2 (ERK1/2). Interestingly, MCFAs activation of GPR84 concomitantly led to the upregulation of inflammatory mediators such as Nuclear Factor Kappa B (NF-κB) and IL-6. Conclusively, this study successfully elucidated the intriguing molecular and functional properties of CGS GPR84, particularly as an immune modulator, and has positioned the findings within the existing body of knowledge for a better overall understanding of GPR84, especially in amphibians.
Persistent organic pollutants (POPs) are toxic chemicals that stay in the environment for a long time. To address the toxicity issues, global nations, including 53 African countries, ratified the Stockholm Convention to minimize or eliminate the production of 12 POPs known as the “Dirty Dozen”. However, these Dirty Dozen Chemicals (DDCs) still exist in significant concentration in the African environment, prompting numerous research to investigate the level of their occurrences. Here, we conducted a bibliometric analysis to examine the publication trends in DDCs-related research in Africa using articles published between 1949 and 2021 from the Web of Science and Scopus databases. A total of 884 articles were published within the survey period, with a publication/author and author/publication ratio of 0.36 and 2.76, respectively. South Africa ranked first in terms of number of publications (n = 133, 15.05%), and total citations (n = 3115), followed by Egypt (n = 117), Nigeria (n = 77), USA (n = 40), and Ghana (n = 38). Research collaboration was relatively high (collaboration index = 2.88). The insignificant difference between the theoretical and observed Lotka's distribution indicates Lotka's law does not fit the DDC literature. An annual growth rate of 0.57% implies that a substantial increase of articles in years to come is not expected. More research programs should be established in other African countries to measure up to South Africa's supremacy. This is critical in order to provide a basis for effective compliance to the Stockholm Convention on POPs in Africa.
In this study, the effect of galena mining with respect to heavy metal pollution of groundwater, surface water, soil and sediments in Enyimagalagu and Mkpuma-Akpatakpa Communities in Ebonyi State, Nigeria, was investigated to estimate the health and economic burden. The heavy metals were measured using atomic absorption spectrometry (AAS). The water quality of the groundwater and surface water was determined using the water quality index (WQI). The potential health burden was estimated by determining carcinogenic and non-carcinogenic health risks via risk index (RI) and hazard index (HI), respectively. The potential economic burden was estimated using the value of statistical life (VSL) and cost of illness (COI). Obtained results revealed that the WQI of the groundwater and surface water ranged from 197 to 327 indicating very poor to unsuitable water for drinking. No non-carcinogenic risks were associated with exposure to the soil and sediment components of the environment. However, there were non-carcinogenic risks associated with the surface and groundwater, with the HIs ranging from 1.8 to 5.4. Based on the carcinogenic risk threshold of 10⁻⁶, there were carcinogenic risks across all the environmental media ranging from 8.4*10⁻⁵ - 2.1*10⁻³. The economic cost of heavy metal pollution ranged from 20.7 million USD (10.35 billion) to 543.3 million USD (271.6 billion) for the VSL, whereas it ranged from 0.141 million USD (70.8 million) to 3.72 million USD (1.86 billion) for the COI. These costs are quite huge and can be avoided via pollution abatement measures.
Geothermal water is rich in lithium (Li) and it can be recovered by adsorption and other methods. Product recovery by adsorption is important for the achievement of a circular economy and the reduction of geogenic Li in the biosphere. This paper aims to review the performance of different adsorbents for the removal of Li from geothermal water. The reported adsorption capacity was between 6 – 69 mg/g for most materials and the optimal pH was about 12. Ion-exchange was the major mechanism of Li uptake onto nano-adsorbents of inorganic origin. Other important mechanisms observed were intercalation with associated hydrogen bonds, electrostatic attraction, intermolecular and intramolecular complexation. The Langmuir isotherm and pseudo-second-order model were best-fit to describe the Li uptake in most cases. Adsorption is observed to have some technical advantages over other processes. It is relatively cheaper, does not have chemical resistance observed in membranes, does not have the limited selectivity and difficulty of integration into industrial processes, and does not possess the high electrical requirement of electrochemical techniques. HCl is the most effective eluent for Li desorption and most adsorbents can be reused over 5 times with good retention of adsorption capacity. Future studies can look into column adsorption of Li, molecular modelling of Li interaction with sorbents, used adsorbent disposal and cost analysis.
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13,283 members
Oguejiofo T. Ujam
  • Department of Pure and Industrial Chemistry
Tonia Onyeka
  • Department of Anesthesia
Mark Okeji
  • Department of Medical Radiography and Radiological Sciences
Chukwuemeka Iyoke
  • Department of Obstetrics and Gynecology
Anthonius Anayochukwu Eze
  • Department of Medical Biochemistry
University Road, 410001, Nsukka, Enugu State, Nigeria
Head of institution
Professor Charles Arizechukwu Igwe