The entropy generation analysis of a thermal process is capable of determining the efficiency of ... more The entropy generation analysis of a thermal process is capable of determining the efficiency of that process and is therefore helpful to optimize the thermal system operating under various conditions. There are several ingredients upon which the phenomenon of entropy generation can depend, such as the nature of flow and the fluid, the assumed conditions, and the material properties of the working fluid. However, the dependence of entropy generation phenomenon upon such properties has so far not been fully realized, in view of the existing literature. On the other hand, based upon the existing studies, it has been established that the non-uniform concentration of nanoparticles in the base fluid does cause to enhance the heat transfer rate. Therefore, it is logical to investigate the entropy production under the impact of non-homogenous distribution of nanoparticles. Based upon this fact the aim of current study is to explore a comprehensive detail about the influence of non-homogene...
To smoothly operate a cloud testbed-style playground of SDN-enabled distributed clusters, we need... more To smoothly operate a cloud testbed-style playground of SDN-enabled distributed clusters, we need a promising solution to collectively monitor distributed clusters in a unified manner that can embrace multiple layers of physical and virtualized resources and inter-connecting flows. Also, it is required to detect various security attacks that exploit the widened attack surface due to virtualization and containerization. Thus, by leveraging multi-layer visibility framework denoted as SmartX MultiView Visibility Framework (MVF) [1], we are currently establishing a security extension of SmartX MVF. However, current tree-style visualization associated with SmartX MVF is not intuitive enough to accommodate the complicated dependencies for multilevel security extension. Therefore, in this paper, an ongoing realization of multi-layer onion-ring visualization is introduced that can support multi-level visibility points for collecting visibility data from multiple layers.
Carissa carandas L. is traditionally used as antibacterial medicine and accumulates many antioxid... more Carissa carandas L. is traditionally used as antibacterial medicine and accumulates many antioxidant phytochemicals. Here, we expand this traditional usage with the green biosynthesis of silver nanoparticles (AgNPs) achieved using a Carissa carandas L. leaf extract as a reducing and capping agent. The green synthesis of AgNPs reaction was carried out using 1mM silver nitrate and leaf extract. The effect of temperature on the synthesis of AgNPs was examined using room temperature (25 °C) and 60 °C. The silver nanoparticles were formed in one hour by stirring at room temperature. In this case, a yellowish brown colour was developed. The successful formation of silver nanoparticles was confirmed by UV–Vis, Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analysis. The characteristic peaks of the UV-vis spectrum and XRD confirmed the synthesis of AgNPs. The biosynthesised AgNPs showed potential antioxidant activity through DPPH assay. These AgNPs also exhibited potential a...
Seedlings recovered from underdeveloped seeds of different commercial cultivars of Citrus were st... more Seedlings recovered from underdeveloped seeds of different commercial cultivars of Citrus were studied for their ploidy level. Cytological examination revealed that maximum triploid plants were found in lime Kaghzi (15.5%) followed by grapefruit Foster, mandarin Kinnow, sweet orange Musambi and mandarin Feutrell’s Early (7.3%). Lime also produced the highest percentage of tetraploids (9.1%) followed by mandarin Kinnow and grapefruit Foster, while the minimum was found in mandarin Feutrell’s Early. The polyploids were transplanted in pots and after hardening they were grown in the greenhouse for further morphological and genetic assays.
Abstract A theranostic nanodelivery system for simultaneous therapeutics and magnetic resonance i... more Abstract A theranostic nanodelivery system for simultaneous therapeutics and magnetic resonance imaging (MRI) diagnostic agents’ delivery was successful synthesized, using Zn/Al−layered double hydroxide (LDH) as the nano-carrier, chlorogenic acid (CA) as the therapeutic agent and gadolinium as the diagnostic contrast agent. The contrast of the MR image was improved with gold nanoparticles (AuNPs), which were coated on the surface of the nanohybrid (ZAGCAu). The kinetic release study was conducted with UV–Vis spectrophotometer and high release was observed (up to 90%). Other characterizations conducted on the nanohybrid include; HRTEM, XRD, FTIR, FESEM and Elemental analysis, which all confirmed the theranostic nanohybrid development (ZAGCAu). Cell viability test (in vitro) was also carried out with ZAGCAu on normal cell lines (3T3) and liver cancer cell lines (HepG2). The results indicated relative cytotoxicity against HepG2 and slight toxicity on the 3T3. The preliminary MRI contrast property of the ZAGCAu was tested to ascertain the inherent signal optimization on a 3 T MRI machine. Various concentrations of the ZAGCAu indicated enhanced T1 and T2 signals in comparison with the Gd and water references used. The preliminary studies conducted on the ZAGCAu nanohybrid developed in this work shows its potentiality as a future theranostic agent for simultaneous diagnostic and therapeutic functions in cancer treatment.
Background The risks and benefits of sodium-glucose co-transporter 2 (SGLT2) inhibitors on cardio... more Background The risks and benefits of sodium-glucose co-transporter 2 (SGLT2) inhibitors on cardiovascular outcomes have not been well established. We pooled evidence from all available clinical trials to assess the cardiovascular effects of this drug. Design A systematic review and meta-analysis of randomised controlled trials. Methods We queried electronic databases (MEDLINE, Scopus, CENTRAL and clinicaltrials.gov) from their inception to July 2017 for published and unpublished placebo controlled trials of SGLT2 inhibitors. Only studies with a follow-up period of at least 24 weeks and reporting at least one cardiovascular outcome were included. Results from trials were presented as odds ratios (ORs) with 95% confidence intervals (CIs) and were pooled using a random-effects model. Results Thirty-five eligible studies (canagliflozin, nine; empagliflozin, eight; dapagliflozin, 18), consisting of 34,987 patients with type 2 diabetes mellitus were included. Pooled results show that SGLT...
Citation classics have been published in many fields of medicine; however, none have focused on i... more Citation classics have been published in many fields of medicine; however, none have focused on interventional cardiology. The goal of this study was to identify the top 100 articles in the field of interventional cardiology and highlight their important trends and characteristics. The Scopus database was used by 2 independent reviewers to extract the top 100 articles using a variety of keywords. We found articles published between 1953 and 2012. Majority (n = 78) of the top 100 articles were published between 1996 and 2010, and the United States was affiliated with the highest number of articles in our list (n = 68). Over half (n = 54) the articles were funded. Private funding was correlated with higher citations (p = 0.036). A third (n = 33) of the papers had authors with conflicts of interest; however, conflict of interest had no effect on citations (p = 0.837). Majority (n = 57) of the articles studied coronary angioplasty and stenting; followed by coronary angiography (n = 14). Women were underrepresented, with only 11 female first authors in the top 100 papers, and only 1 female in the list of top authors who had 5 or more publications. In conclusion, the following features define the typical highly cited article in interventional cardiology-a clinical trial conducted in the United States, which studies angioplasty, and has been published relatively recently in a high-impact journal by a male first author.
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2009
Ion implantation induced defects and their consequent electrical impact have been investigated. U... more Ion implantation induced defects and their consequent electrical impact have been investigated. Unintentionally doped n-type gallium nitride was implanted with 100keV Si+ and 300keV Ar+ ions in a fluence range of 1014–1015ions/cm2. The samples were characterized with Rutherford backscattering/Channeling method for damage buildup. Time of flight elastic recoil detection analysis was implied on the Si implanted samples to see the
Introduction: Although evidence exists that adolescents' hypertension could lead to adults' hyper... more Introduction: Although evidence exists that adolescents' hypertension could lead to adults' hypertension, it is a general belief that measures for early detection and treatment of this condition is seldom undertaken especially in medically underserved communities such as Maiduguri, Northeastern Nigeria. This study investigated the prevalence of undiagnosed hypertension among adolescents in Maiduguri, Nigeria, and explored the association between undiagnosed hypertension and adolescents' physical characteristics and parental socio-demographic factors. Methods: Participants' physical characteristics were assessed, and information on their socio-demographics including parental socioeconomic status were obtained. Blood pressures and heart rates of the participants were also measured three times at 5-10-min period. Results: The prevalence of undiagnosed hypertension among the students was 13.2 %, and overwhelming majority (82.4 %) of the hypertensive students were in the prehypertensive stage, while 17.6 % were in the stage 1 classification of hypertension. Higher prevalence of undiagnosed hypertension was observed for the females compared to the male adolescents (X 2 = 15.49, p = 0.001), and presence of undiagnosed hypertension is positively but tenuously linked to age (r = 0.11, p = 0.01), body mass index (r = 0.10, p = 0.01), and parental income (r = 0.26, p = 0.02) of the students. Discussion: This study suggests that any effective programs designed to mitigate undiagnosed hypertension among adolescents in this city should include strategies that address possible barriers to physical activity and exercise among female adolescents in the society.
Lecture Notes in Nanoscale Science and Technology, 2013
In this chapter, we analyze the polarization response of multi-layer quantum dot molecules (QDMs)... more In this chapter, we analyze the polarization response of multi-layer quantum dot molecules (QDMs) containing up to nine vertically stacked quantum dot layers by carrying out a systematic set of multi-million atom simulations. The atomistic modeling and simulations allow us to include correct symmetry properties in the calculations of the electronic and optical spectra: a factor critical to explain the experimental evidence. The values of the degree of polarization (DOP) calculated from our model based on the geometry parameters directly extracted from the experimental TEM images follow the trends of the recently published experimental data. We also present detailed physical insight of the fundamental underlying physics by examining strain profiles, band edges diagrams, and wave function plots. Multi-directional calculations of the DOP reveal a unique property of the InAs QDMs that the TE response in the plane perpendicular to the growth direction is highly anisotropic. Therefore we propose that a single value of the DOP is not sufficient to fully characterize the polarization response. We explain this anisotropy of the TE modes in terms of the orientation of the hole wave functions that align along the [110] direction. Our results provide a new insight that the isotropic polarization response measured in the experimental PL spectra is due to two factors: (i) TM [001] mode increases due to enhanced intermixing of HH and LH bands and (ii) TE [110] mode reduces significantly due to the hole wave function alignments along the [110] direction. This is in contrast to general notion that only an increase in the TM [001] mode is responsible for the isotropic polarization. We also present polarization response as a function of various geometry configurations of the quantum dot layers to provide a guide to experimentalists for the design of optical devices based on multi-layer QDMs.
ABSTRACT Chemical vapor deposition graphene growth results are inconsistent, specifying that cruc... more ABSTRACT Chemical vapor deposition graphene growth results are inconsistent, specifying that crucial growth parameters still remain unknown or uncontrolled. In current study, we demonstrate that water can be used as a special tool to control thickness and size of graphene islands, during ambient pressure chemical vapor deposition growth of graphene. Large area bi-layer graphene was synthesized using optimized condition in the absence of water, which was later used as reference condition for water assisted growth of multilayer graphene (MLG), by introducing water vapors during the growth stage. Raman Spectroscopy, UV-Vis spectroscopy and Transmission Electron Microscopy were used to estimate the quality and thickness of graphene. It was observed that graphene thickness increases from 2 to 25 layers with increase in water vapors ranging from zero to 2000 ppmv, which revealed significant improvement in growth rate. Scanning electron microscopy results exhibited growth of discontinuous graphene islands which reveal the etching behavior of water vapors. In conclusion, water plays dual role during growth of graphene, i.e. speed up growth rate, subsequently result in MLG growth, as well as etching of graphene edges.
Archives of public health = Archives belges de santé publique, 2014
Childhood vaccination rates in Nigeria are among the lowest in the world and this affects morbidi... more Childhood vaccination rates in Nigeria are among the lowest in the world and this affects morbidity and mortality rates. A 2011 mixed methods study in two states in Nigeria examined coverage of measles vaccination and reasons for not vaccinating children. A household survey covered a stratified random cluster sample of 180 enumeration areas in Bauchi and Cross River States. Cluster-adjusted bivariate and then multivariate analysis examined associations between measles vaccination and potential determinants among children aged 12-23 months, including household socio-economic status, parental knowledge and attitudes about vaccination, and access to vaccination services. Focus groups of parents in the same sites subsequently discussed the survey findings and gave reasons for non-vaccination. A knowledge to action strategy shared findings with stakeholders, including state government, local governments and communities, to stimulate evidence-based actions to increase vaccination rates. I...
Electrons and holes captured in self-assembled quantum dots (QDs) are subject to symmetry breakin... more Electrons and holes captured in self-assembled quantum dots (QDs) are subject to symmetry breaking that cannot be represented in with continuum material representations. Atomistic calculations reveal symmetry lowering due to effects of strain and piezo-electric fields. These effects are fundamentally based on the crystal topology in the quantum dots. This work studies these two competing effects and demonstrates the fine structure splitting that has been demonstrated experimentally can be attributed to the underlying atomistic structure of the quantum dots.
Surface Topography: Metrology and Properties, 2014
ABSTRACT Metal organic chemical vapor deposited (MOCVD) thin films of aluminum nitride (AlN) were... more ABSTRACT Metal organic chemical vapor deposited (MOCVD) thin films of aluminum nitride (AlN) were irradiated with 700 keV Ni ions at fluences of 1 × 1012, 1 × 1013, and 1 × 1014 ions cm−2. The stopping and range of ions in matter (SRIM) analysis was performed to investigate the depth distribution of the Ni ions and vacancy production in AlN film. The x-ray diffraction (XRD) patterns of the implanted samples show a shift of the AlN (0 0 2) orientation peak towards higher angles at 1 × 1012 ions cm−2, exhibiting the incorporation of nickel ions into the AlN phase. The XRD patterns also demonstrated a reduction in shift of the (0 0 2) orientation peak along with the formation of AlNi3 phase with the increase of ion fluence. The AFM surface analysis of the ion-irradiated AlN film exhibits a rise of film surface roughness. After ion irradiation, the samples were annealed at 900 °C in a nitrogen environment. Annealing reduces the surface roughness of not only the implanted samples but also the as-grown samples.
Emergence of multi-drug resistant (MDR) and extensively drug resistant (XDR) TB throughout the de... more Emergence of multi-drug resistant (MDR) and extensively drug resistant (XDR) TB throughout the developing world is very disturbing in the present scenario of TB management. There is a fundamental need to explore alternative anti-TB agents. Hence natural plants should be investigated to understand their antimicrobial properties and safety. Garlic (Allium sativum) is one of natural plant which possesses variety of biological properties like anti-tumor, anti-hyperlipedemic and anti-microbial etc. The present study was evaluated for anti-bacterial activity of garlic against non-MDR and MDR isolates of M. tuberculosis. A total of 20 clinical isolates of MTB including 15 MDR and 5 non-MDR were investigated. Ethanolic extract of garlic was prepared by maceration method. Minimum inhibitory concentration (MIC) was performed by using 7H9 middle brook broth dilution technique. MIC of garlic extract was ranged from 1 to 3 mg/ml; showing inhibitory effects of garlic against both non-MDR and MDR ...
In this study we present the dependence of electrical properties of copper phthalocyanine (CuPc) ... more In this study we present the dependence of electrical properties of copper phthalocyanine (CuPc) and metal free phthalocyanine (H 2 Pc) bulk heterojunction structure under different illumination levels. To fabricate the device on ITO coated glass substrate the bulk heterojunction thin film of CuPc and H 2 Pc with thickness varying from 100 nm to 300 nm are deposited by thermal evaporator. Aluminum thin film was deposited by thermal evaporation as a top contact. The optical properties of the fabricated device are investigated using UV-vis spectroscopy. The current-voltage characteristics in dark and under illumination show that the device is sensitive towards visible light. The absorption spectrum describes its photo sensitivity in the range of wavelength from 200 nm to 850 nm. Simulation of current-intensity of light curve is carried out and experimental results are found in good agreement with simulated ones.
Climate change aggravates degradation of the sub-humid and dry land ecosystem of the Sudano-Sahel... more Climate change aggravates degradation of the sub-humid and dry land ecosystem of the Sudano-Sahelian belt of Nigeria (Long. 3 0-15 0 East and Lat. 9 0-14 0 North). This has intensified aridity and aggravated plants moisture stress and subsequently decreasing the landscape ecology and bio-productivity of the physical environment in the belt. There is need to identify changes, trend and visualize the extent of aridity in the belt, lack of information on changes that have taken place is evident thus, the need to investigate and map changes that have taken place in the belt to identify sustainable issues for adaptation. This study used derived indicators of eco-climate parameters (1950-2006); rainfall related-onset dates, cessation dates, Moisture Quality Index, hydrologic growing season (HGS) and Aridity Index (AI). These were summarized; decadal mean determined and ranked using numerical identifiers for the interpretation of the decadal moisture effectiveness across the belt. The point data were transformed to spatial data, surfaces were interpolated, mapped and the area extent of each Moisture Effectiveness zone (MEZ) was used to determine spatio-temporal aridity trend. The result signals rapid advancement of desert condition such that areas of deficient moisture zones grew significantly. Consequently, the eco-climatic and agro-climatic zones we have always known might have been affected and need to be redefined using modern geospatial techniques.
The entropy generation analysis of a thermal process is capable of determining the efficiency of ... more The entropy generation analysis of a thermal process is capable of determining the efficiency of that process and is therefore helpful to optimize the thermal system operating under various conditions. There are several ingredients upon which the phenomenon of entropy generation can depend, such as the nature of flow and the fluid, the assumed conditions, and the material properties of the working fluid. However, the dependence of entropy generation phenomenon upon such properties has so far not been fully realized, in view of the existing literature. On the other hand, based upon the existing studies, it has been established that the non-uniform concentration of nanoparticles in the base fluid does cause to enhance the heat transfer rate. Therefore, it is logical to investigate the entropy production under the impact of non-homogenous distribution of nanoparticles. Based upon this fact the aim of current study is to explore a comprehensive detail about the influence of non-homogene...
To smoothly operate a cloud testbed-style playground of SDN-enabled distributed clusters, we need... more To smoothly operate a cloud testbed-style playground of SDN-enabled distributed clusters, we need a promising solution to collectively monitor distributed clusters in a unified manner that can embrace multiple layers of physical and virtualized resources and inter-connecting flows. Also, it is required to detect various security attacks that exploit the widened attack surface due to virtualization and containerization. Thus, by leveraging multi-layer visibility framework denoted as SmartX MultiView Visibility Framework (MVF) [1], we are currently establishing a security extension of SmartX MVF. However, current tree-style visualization associated with SmartX MVF is not intuitive enough to accommodate the complicated dependencies for multilevel security extension. Therefore, in this paper, an ongoing realization of multi-layer onion-ring visualization is introduced that can support multi-level visibility points for collecting visibility data from multiple layers.
Carissa carandas L. is traditionally used as antibacterial medicine and accumulates many antioxid... more Carissa carandas L. is traditionally used as antibacterial medicine and accumulates many antioxidant phytochemicals. Here, we expand this traditional usage with the green biosynthesis of silver nanoparticles (AgNPs) achieved using a Carissa carandas L. leaf extract as a reducing and capping agent. The green synthesis of AgNPs reaction was carried out using 1mM silver nitrate and leaf extract. The effect of temperature on the synthesis of AgNPs was examined using room temperature (25 °C) and 60 °C. The silver nanoparticles were formed in one hour by stirring at room temperature. In this case, a yellowish brown colour was developed. The successful formation of silver nanoparticles was confirmed by UV–Vis, Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analysis. The characteristic peaks of the UV-vis spectrum and XRD confirmed the synthesis of AgNPs. The biosynthesised AgNPs showed potential antioxidant activity through DPPH assay. These AgNPs also exhibited potential a...
Seedlings recovered from underdeveloped seeds of different commercial cultivars of Citrus were st... more Seedlings recovered from underdeveloped seeds of different commercial cultivars of Citrus were studied for their ploidy level. Cytological examination revealed that maximum triploid plants were found in lime Kaghzi (15.5%) followed by grapefruit Foster, mandarin Kinnow, sweet orange Musambi and mandarin Feutrell’s Early (7.3%). Lime also produced the highest percentage of tetraploids (9.1%) followed by mandarin Kinnow and grapefruit Foster, while the minimum was found in mandarin Feutrell’s Early. The polyploids were transplanted in pots and after hardening they were grown in the greenhouse for further morphological and genetic assays.
Abstract A theranostic nanodelivery system for simultaneous therapeutics and magnetic resonance i... more Abstract A theranostic nanodelivery system for simultaneous therapeutics and magnetic resonance imaging (MRI) diagnostic agents’ delivery was successful synthesized, using Zn/Al−layered double hydroxide (LDH) as the nano-carrier, chlorogenic acid (CA) as the therapeutic agent and gadolinium as the diagnostic contrast agent. The contrast of the MR image was improved with gold nanoparticles (AuNPs), which were coated on the surface of the nanohybrid (ZAGCAu). The kinetic release study was conducted with UV–Vis spectrophotometer and high release was observed (up to 90%). Other characterizations conducted on the nanohybrid include; HRTEM, XRD, FTIR, FESEM and Elemental analysis, which all confirmed the theranostic nanohybrid development (ZAGCAu). Cell viability test (in vitro) was also carried out with ZAGCAu on normal cell lines (3T3) and liver cancer cell lines (HepG2). The results indicated relative cytotoxicity against HepG2 and slight toxicity on the 3T3. The preliminary MRI contrast property of the ZAGCAu was tested to ascertain the inherent signal optimization on a 3 T MRI machine. Various concentrations of the ZAGCAu indicated enhanced T1 and T2 signals in comparison with the Gd and water references used. The preliminary studies conducted on the ZAGCAu nanohybrid developed in this work shows its potentiality as a future theranostic agent for simultaneous diagnostic and therapeutic functions in cancer treatment.
Background The risks and benefits of sodium-glucose co-transporter 2 (SGLT2) inhibitors on cardio... more Background The risks and benefits of sodium-glucose co-transporter 2 (SGLT2) inhibitors on cardiovascular outcomes have not been well established. We pooled evidence from all available clinical trials to assess the cardiovascular effects of this drug. Design A systematic review and meta-analysis of randomised controlled trials. Methods We queried electronic databases (MEDLINE, Scopus, CENTRAL and clinicaltrials.gov) from their inception to July 2017 for published and unpublished placebo controlled trials of SGLT2 inhibitors. Only studies with a follow-up period of at least 24 weeks and reporting at least one cardiovascular outcome were included. Results from trials were presented as odds ratios (ORs) with 95% confidence intervals (CIs) and were pooled using a random-effects model. Results Thirty-five eligible studies (canagliflozin, nine; empagliflozin, eight; dapagliflozin, 18), consisting of 34,987 patients with type 2 diabetes mellitus were included. Pooled results show that SGLT...
Citation classics have been published in many fields of medicine; however, none have focused on i... more Citation classics have been published in many fields of medicine; however, none have focused on interventional cardiology. The goal of this study was to identify the top 100 articles in the field of interventional cardiology and highlight their important trends and characteristics. The Scopus database was used by 2 independent reviewers to extract the top 100 articles using a variety of keywords. We found articles published between 1953 and 2012. Majority (n = 78) of the top 100 articles were published between 1996 and 2010, and the United States was affiliated with the highest number of articles in our list (n = 68). Over half (n = 54) the articles were funded. Private funding was correlated with higher citations (p = 0.036). A third (n = 33) of the papers had authors with conflicts of interest; however, conflict of interest had no effect on citations (p = 0.837). Majority (n = 57) of the articles studied coronary angioplasty and stenting; followed by coronary angiography (n = 14). Women were underrepresented, with only 11 female first authors in the top 100 papers, and only 1 female in the list of top authors who had 5 or more publications. In conclusion, the following features define the typical highly cited article in interventional cardiology-a clinical trial conducted in the United States, which studies angioplasty, and has been published relatively recently in a high-impact journal by a male first author.
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2009
Ion implantation induced defects and their consequent electrical impact have been investigated. U... more Ion implantation induced defects and their consequent electrical impact have been investigated. Unintentionally doped n-type gallium nitride was implanted with 100keV Si+ and 300keV Ar+ ions in a fluence range of 1014–1015ions/cm2. The samples were characterized with Rutherford backscattering/Channeling method for damage buildup. Time of flight elastic recoil detection analysis was implied on the Si implanted samples to see the
Introduction: Although evidence exists that adolescents' hypertension could lead to adults' hyper... more Introduction: Although evidence exists that adolescents' hypertension could lead to adults' hypertension, it is a general belief that measures for early detection and treatment of this condition is seldom undertaken especially in medically underserved communities such as Maiduguri, Northeastern Nigeria. This study investigated the prevalence of undiagnosed hypertension among adolescents in Maiduguri, Nigeria, and explored the association between undiagnosed hypertension and adolescents' physical characteristics and parental socio-demographic factors. Methods: Participants' physical characteristics were assessed, and information on their socio-demographics including parental socioeconomic status were obtained. Blood pressures and heart rates of the participants were also measured three times at 5-10-min period. Results: The prevalence of undiagnosed hypertension among the students was 13.2 %, and overwhelming majority (82.4 %) of the hypertensive students were in the prehypertensive stage, while 17.6 % were in the stage 1 classification of hypertension. Higher prevalence of undiagnosed hypertension was observed for the females compared to the male adolescents (X 2 = 15.49, p = 0.001), and presence of undiagnosed hypertension is positively but tenuously linked to age (r = 0.11, p = 0.01), body mass index (r = 0.10, p = 0.01), and parental income (r = 0.26, p = 0.02) of the students. Discussion: This study suggests that any effective programs designed to mitigate undiagnosed hypertension among adolescents in this city should include strategies that address possible barriers to physical activity and exercise among female adolescents in the society.
Lecture Notes in Nanoscale Science and Technology, 2013
In this chapter, we analyze the polarization response of multi-layer quantum dot molecules (QDMs)... more In this chapter, we analyze the polarization response of multi-layer quantum dot molecules (QDMs) containing up to nine vertically stacked quantum dot layers by carrying out a systematic set of multi-million atom simulations. The atomistic modeling and simulations allow us to include correct symmetry properties in the calculations of the electronic and optical spectra: a factor critical to explain the experimental evidence. The values of the degree of polarization (DOP) calculated from our model based on the geometry parameters directly extracted from the experimental TEM images follow the trends of the recently published experimental data. We also present detailed physical insight of the fundamental underlying physics by examining strain profiles, band edges diagrams, and wave function plots. Multi-directional calculations of the DOP reveal a unique property of the InAs QDMs that the TE response in the plane perpendicular to the growth direction is highly anisotropic. Therefore we propose that a single value of the DOP is not sufficient to fully characterize the polarization response. We explain this anisotropy of the TE modes in terms of the orientation of the hole wave functions that align along the [110] direction. Our results provide a new insight that the isotropic polarization response measured in the experimental PL spectra is due to two factors: (i) TM [001] mode increases due to enhanced intermixing of HH and LH bands and (ii) TE [110] mode reduces significantly due to the hole wave function alignments along the [110] direction. This is in contrast to general notion that only an increase in the TM [001] mode is responsible for the isotropic polarization. We also present polarization response as a function of various geometry configurations of the quantum dot layers to provide a guide to experimentalists for the design of optical devices based on multi-layer QDMs.
ABSTRACT Chemical vapor deposition graphene growth results are inconsistent, specifying that cruc... more ABSTRACT Chemical vapor deposition graphene growth results are inconsistent, specifying that crucial growth parameters still remain unknown or uncontrolled. In current study, we demonstrate that water can be used as a special tool to control thickness and size of graphene islands, during ambient pressure chemical vapor deposition growth of graphene. Large area bi-layer graphene was synthesized using optimized condition in the absence of water, which was later used as reference condition for water assisted growth of multilayer graphene (MLG), by introducing water vapors during the growth stage. Raman Spectroscopy, UV-Vis spectroscopy and Transmission Electron Microscopy were used to estimate the quality and thickness of graphene. It was observed that graphene thickness increases from 2 to 25 layers with increase in water vapors ranging from zero to 2000 ppmv, which revealed significant improvement in growth rate. Scanning electron microscopy results exhibited growth of discontinuous graphene islands which reveal the etching behavior of water vapors. In conclusion, water plays dual role during growth of graphene, i.e. speed up growth rate, subsequently result in MLG growth, as well as etching of graphene edges.
Archives of public health = Archives belges de santé publique, 2014
Childhood vaccination rates in Nigeria are among the lowest in the world and this affects morbidi... more Childhood vaccination rates in Nigeria are among the lowest in the world and this affects morbidity and mortality rates. A 2011 mixed methods study in two states in Nigeria examined coverage of measles vaccination and reasons for not vaccinating children. A household survey covered a stratified random cluster sample of 180 enumeration areas in Bauchi and Cross River States. Cluster-adjusted bivariate and then multivariate analysis examined associations between measles vaccination and potential determinants among children aged 12-23 months, including household socio-economic status, parental knowledge and attitudes about vaccination, and access to vaccination services. Focus groups of parents in the same sites subsequently discussed the survey findings and gave reasons for non-vaccination. A knowledge to action strategy shared findings with stakeholders, including state government, local governments and communities, to stimulate evidence-based actions to increase vaccination rates. I...
Electrons and holes captured in self-assembled quantum dots (QDs) are subject to symmetry breakin... more Electrons and holes captured in self-assembled quantum dots (QDs) are subject to symmetry breaking that cannot be represented in with continuum material representations. Atomistic calculations reveal symmetry lowering due to effects of strain and piezo-electric fields. These effects are fundamentally based on the crystal topology in the quantum dots. This work studies these two competing effects and demonstrates the fine structure splitting that has been demonstrated experimentally can be attributed to the underlying atomistic structure of the quantum dots.
Surface Topography: Metrology and Properties, 2014
ABSTRACT Metal organic chemical vapor deposited (MOCVD) thin films of aluminum nitride (AlN) were... more ABSTRACT Metal organic chemical vapor deposited (MOCVD) thin films of aluminum nitride (AlN) were irradiated with 700 keV Ni ions at fluences of 1 × 1012, 1 × 1013, and 1 × 1014 ions cm−2. The stopping and range of ions in matter (SRIM) analysis was performed to investigate the depth distribution of the Ni ions and vacancy production in AlN film. The x-ray diffraction (XRD) patterns of the implanted samples show a shift of the AlN (0 0 2) orientation peak towards higher angles at 1 × 1012 ions cm−2, exhibiting the incorporation of nickel ions into the AlN phase. The XRD patterns also demonstrated a reduction in shift of the (0 0 2) orientation peak along with the formation of AlNi3 phase with the increase of ion fluence. The AFM surface analysis of the ion-irradiated AlN film exhibits a rise of film surface roughness. After ion irradiation, the samples were annealed at 900 °C in a nitrogen environment. Annealing reduces the surface roughness of not only the implanted samples but also the as-grown samples.
Emergence of multi-drug resistant (MDR) and extensively drug resistant (XDR) TB throughout the de... more Emergence of multi-drug resistant (MDR) and extensively drug resistant (XDR) TB throughout the developing world is very disturbing in the present scenario of TB management. There is a fundamental need to explore alternative anti-TB agents. Hence natural plants should be investigated to understand their antimicrobial properties and safety. Garlic (Allium sativum) is one of natural plant which possesses variety of biological properties like anti-tumor, anti-hyperlipedemic and anti-microbial etc. The present study was evaluated for anti-bacterial activity of garlic against non-MDR and MDR isolates of M. tuberculosis. A total of 20 clinical isolates of MTB including 15 MDR and 5 non-MDR were investigated. Ethanolic extract of garlic was prepared by maceration method. Minimum inhibitory concentration (MIC) was performed by using 7H9 middle brook broth dilution technique. MIC of garlic extract was ranged from 1 to 3 mg/ml; showing inhibitory effects of garlic against both non-MDR and MDR ...
In this study we present the dependence of electrical properties of copper phthalocyanine (CuPc) ... more In this study we present the dependence of electrical properties of copper phthalocyanine (CuPc) and metal free phthalocyanine (H 2 Pc) bulk heterojunction structure under different illumination levels. To fabricate the device on ITO coated glass substrate the bulk heterojunction thin film of CuPc and H 2 Pc with thickness varying from 100 nm to 300 nm are deposited by thermal evaporator. Aluminum thin film was deposited by thermal evaporation as a top contact. The optical properties of the fabricated device are investigated using UV-vis spectroscopy. The current-voltage characteristics in dark and under illumination show that the device is sensitive towards visible light. The absorption spectrum describes its photo sensitivity in the range of wavelength from 200 nm to 850 nm. Simulation of current-intensity of light curve is carried out and experimental results are found in good agreement with simulated ones.
Climate change aggravates degradation of the sub-humid and dry land ecosystem of the Sudano-Sahel... more Climate change aggravates degradation of the sub-humid and dry land ecosystem of the Sudano-Sahelian belt of Nigeria (Long. 3 0-15 0 East and Lat. 9 0-14 0 North). This has intensified aridity and aggravated plants moisture stress and subsequently decreasing the landscape ecology and bio-productivity of the physical environment in the belt. There is need to identify changes, trend and visualize the extent of aridity in the belt, lack of information on changes that have taken place is evident thus, the need to investigate and map changes that have taken place in the belt to identify sustainable issues for adaptation. This study used derived indicators of eco-climate parameters (1950-2006); rainfall related-onset dates, cessation dates, Moisture Quality Index, hydrologic growing season (HGS) and Aridity Index (AI). These were summarized; decadal mean determined and ranked using numerical identifiers for the interpretation of the decadal moisture effectiveness across the belt. The point data were transformed to spatial data, surfaces were interpolated, mapped and the area extent of each Moisture Effectiveness zone (MEZ) was used to determine spatio-temporal aridity trend. The result signals rapid advancement of desert condition such that areas of deficient moisture zones grew significantly. Consequently, the eco-climatic and agro-climatic zones we have always known might have been affected and need to be redefined using modern geospatial techniques.
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