The proposed mechanism of bactericidal action of eugenol, &#8733-terpineol and g-terpinene against Listeria monocytogenes, Streptococcus pyogenes, Proteus vulgaris and Escherichia coli

The mechanism of antimicrobial activity of essential oils components; - terpineol, g-terpinene and eugenol was studied to evaluate their effect on the bacterial membrane against four strains of bacteria:Listeria monocytogenes, Streptococcus pyogenes, Proteus vulgaris and Escherichia coli. The study was done to observe changes in membrane composition by assaying for the leakage of protein and lipid using Bradford and van Handel’s method respectively. The oils components were capable of inducing cell lysis by the leakage of protein and lipid contents. Eugenol at 2 × MIC was highly effective toward protein content leakage after 120 min of exposure. Alpha terpineol and g-terpinene showed similar effect at 2 × MIC under the same condition. Gamma terpinene displayed the highest activity toward lipid content leakage at 2 x MIC while -terpineol and eugenol showed similar effect after 120 min of exposure. The result revealed that both cell wall and membrane of the treated gram negative and gram positive bacteria were significantly damaged

Assessment of the Nutrient Status of Soil under Chromolaena odorata L. (Siam Weed) Fallow in Moniya, Oyo State Southwestern Nigeria

In Nigeria, soil fertility restoration for improved agricultural production is a recurrent issue of immense importance mostly with her ever increasing population currently above 150 million. Therefore, identifying sustainable ecological practice to improve soil fertility is one of the surest ways to enhance food security. The study examined the trend in soil nutrient under the canopy of Chromolaena odorata of zero, 6 months, 1 yr and 2 yr fallows. The grid system of sampling was employed to collect soil samples from ten quadrats of 5m x 5m in each of the Chromolaena fallows. Result showed that C. odorata, a plant of secondary succession had significant effect on the buildup of nutrients in the soil, as the contents of soil properties under the canopy of C. odorata progressively increased with the age of fallows, which perhaps was affected by the increase in Chromolaena plant and cover. The pH level of soils under the canopy of C. odorata especially in the 2nd year fallow considerably favoured the increase in the contents of essential elements in the soil. However, to improve soil fertility, the study suggested that C. plantshould be planted along with staple crops to help minimize nutrient loss, and also, fallows with C. plantsshould be allowed for a reasonable number of years to facilitate nutrient accretion before cultivation.Keywords: Chromolaena Density, Nutrient Status, Physical and Chemical Properties, Nutrient Accretio

Effect of ion species on the accumulation of ion-beam damage in GaN

Wurtzite GaN epilayers bombarded with a wide range of ion species (10 keV H-1, 40 keV C-12, 50 keV O-16, 600 keV Si-28, 130 keV Cu-63, 200 keV Ag-107, 300 keV Au-197, and 500 keV Bi-209) are studied by a combination of Rutherford backscattering/channeling (RBS/C) spectrometry and cross-sectional transmission electron microscopy. Results show that strong dynamic annealing processes lead to a complex dependence of the damage-buildup behavior in GaN on ion species. For room-temperature bombardment with different ion species, bulk disorder, as measured by RBS/C, saturates at some level that is below the random level, and amorphization proceeds layer-by-layer from the GaN surface with increasing ion dose. The saturation level of bulk disorder depends on implant conditions and is much higher for light-ion bombardment than for the heavy-ion irradiation regime. In the case of light ions, when ion doses needed to observe significant lattice disorder in GaN are large (greater than or similar to 10(16) cm(-2)), chemical effects of implanted species dominate. Such implanted atoms appear to stabilize an amorphous phase in GaN and/or to act as effective traps for ion-beam-generated mobile point defects and enhance damage buildup. In particular, the presence of a large conce ntration of carbon in GaN strongly enhances the accumulation of implantation-produced disorder. For heavier ions, where chemical effects of implanted species seem to be negligible, an increase in the density of collision cascades strongly increases the level of implantation-produced lattice disorder in the bulk as well as the rate of layer-by-layer amorphization proceeding from the surface. Such an increase in stable damage and the rate of planar amorphization is attributed to (i) an increase in the defect clustering efficiency with increasing density of ion-beam-generated defects and/or (ii) a superlinear dependence of ion-beam-generated defects, which survive cascade quenching, on the density of collision cascades. Physical mechanisms responsible for such a superlinear dependence of ion-beam-generated defects on collision cascade density are considered. Mechanisms of surface and bulk amorphization in GaN are also discussed

Chronic kidney disease screening and renoprotection in type 2 diabetes

Background: Type 2 diabetes (T2D) is a major cause of chronic kidney disease. Control of hypertension and the use of angiotensin converting enzyme inhibitors (ACEI) and/or angiotensin II receptor blockers especially in those with proteinuria have been shown to protect against chronic kidney disease and delay its progression to kidney failure. Methods: We reviewed the medical records of 169 patients at 12 months with a view of auditing the screening for chronic kidney disease and the use of renoprotective measures. Results: Urinalysis was done in 49.1% and serum creatinine in 50.3%. No patient had glomerular filtration rate estimated. Seventy nine (67.6%) of the hypertensive patients were on anti-hypertensives. ACEI was used in 49 (45.8%) of these patients BP control was optimal in 29.1%. Conclusion: There is poor adherence to guidelines on chronic kidney disease screening and renoprotection in T2D

Intrapartum prediction of birth weight using maternal anthropometric measurements and ultrasound scan

This prospective study was conducted at Federal Medical Centre, Owo, Nigeria, between April 1st and 31st of July, 2013 to predict birth weight in labour using four clinical methods and ultrasound scan independently and comparatively to determine which is closest to the actual birth weight. The four clinical methods are Ojwang's formula, Johnson's formula, 5% of maternal weight and 10% of maternal body mass index. A total of 100 women who fulfilled the inclusion criteria had their foetal weight estimated using the methods. Accuracy of the prediction was determined by mean weight difference, percentage error and proportion of estimates within 10% of actual birth weight.Tests of significant difference were done and the level of significance was set at 0.05.Correlation and regression analyses were carried out.Of the five methods used, ultrasound scan estimation had the highest correlation coefficient of 0.681(P<0.001) followed by Ojwang's rule with correlation coefficient of 0.675(P<0.001). The prediction using Johnson's method performed next to Ojwang's rule with correlation coefficient of 0.629(P<0.001).The methods using 5% maternal weight and 10% maternal BMI had correlation coefficients of 0.312(P<0.001) and 0.220(P<0.001) respectively. It was then concluded that there is positive significant correlation between the methods used and actual birth weight. The method using 10% maternal BMI is the least reliable while the ultrasound scan estimate was the most reliable. Ojwang's rule estimation performed next to ultrasound and should be considered first in settings where ultrasound machine or the expertise to use the machine is lacking.Keywords: Birth weight, Foetal weight, Ultrasonography, Pregnancy, Delivery, Prospective studie

The pattern of infection and in vivo response to Chloroquine by uncomplicated Plasmodium falciparum malaria in northwestern Nigeria

The pattern of infection and in vivo response of uncomplicated Plasmodium falciparum malaria to Chloroquine as first line drug and Quinine, Halofantrine or Sulfadoxine-Pyrimethamine as second line medications was evaluated at nested sentinel points, including Government and Private Practices, for three consecutive months. 559 cases were evaluated of which 22.5% failed on Chloroquine therapy. The age range of P. falciparum malaria cases was 4 months to 48 years, with a mean and median age of 9.2 and 3 years, respectively. There were significantly more female patients than male. Also, ages 5 years and below accounted for 63.2% of cases and as a group had an increased risk of treatment failure with Chloroquine compared to older patients. In general, male patients also had a higher relative risk of treatment failure on Chloroquine. Patients treated in Government practices were more likely to fail than those treated in Private practices. All cases of failure to Chloroquine treatment responded to Quinine, Halofantrine or Sulfadoxine-Pyrimethamine. Key Words: Plasmodium falciparum malaria, Chloroquine, resistance. African Journal of Biotechnology Vol.4(1) 2005: 79-8

In Vivo Comparative Evaluation of Effects of Artemeter-Lumefantrine, Sulphadoxine-Pyrimetamine and Halofantrine on G6PD Activities, Haemoglobin Concentration and Malaria Parasite Clearance Rate in Malaria Infected Adults

Background: The use of antimalaria combination therapy especially regimens containing an artemisin-based compound has been recommended as a good first-line treatment for malaria by WHO. However, limited reports exist on the effects of the ACT and other antimalarial drugs on some vital biological parameters such as G6PD activity and haemoglobin concentration. In this study, we investigated the effects of Artemeter-Lumefantrine, sulphadoxine-pyrimetamine combination therapies and Halofantrine monotherapy on G6PD activity, Haemoglobin level and parasite clearance rate in malaria-infected adults treated with the drugs in Enugu, Nigeria. Methodology: Forty malaria-infected adults aged between 20 and 30 years were used. The subjects were divided into four groups (A, B, C and D). The groups A, B and C were given Artemeter-Lumefantrine, sulphadoxine-pyrimetamine and halofantrine respectively, while group D was a control group (malaria-positive control). Blood samples of the subjects were collected through venepuncture at baseline (Day 0) and after treatment on Day 4, for comparative analysis of G6PD activity, haemoglobin concentration and parasite clearance for each group. Results: The result of this study showed that sulphadoxine-pyrimetamine significantly (p<0.05) lowered haemoglobin concentration as compared with Halofantrine, Artemeter-lumefantrine and control. The haemoglobin concentration of the last three groups did not show any significant difference (p>0.05) between each other. The G6PD activity of the group treated with sulphadoxine-pyrimetamine was significantly (p<0.05) higher as compared with that treated with Artemeter-lumefantrine but non-significant (p>0.05) as compared with halofantrine and control. Parasite clearance rate was significantly (p<0.05) highest with the Halofantrine group (76%, p< 0.05) while Sulphadoxine-pyrimetamine had the lowest (52%) parasite clearance. Conclusion: This study therefore indicated that antimalaria drugs as well as malaria parasite could cause a reduction in haemoglobin concentration with sulphadoxine-pyrimetamine causing significant (p<0.05) increase in G-6-PD activity. Keywords: Antimalarials, Artemether-Lumefantrine, G6PD, sulphadoxine-pyrimetamine, Parasite clearance, Halofantrine, Haemoglobin concentratio

Extremely long quasiparticle spin lifetimes in superconducting aluminium using MgO tunnel spin injectors

There has been an intense search in recent years for long-lived spin-polarized carriers for spintronic and quantum-computing devices. Here we report that spin polarized quasi-particles in superconducting aluminum layers have surprisingly long spin-lifetimes, nearly a million times longer than in their normal state. The lifetime is determined from the suppression of the aluminum's superconductivity resulting from the accumulation of spin polarized carriers in the aluminum layer using tunnel spin injectors. A Hanle effect, observed in the presence of small in-plane orthogonal fields, is shown to be quantitatively consistent with the presence of long-lived spin polarized quasi-particles. Our experiments show that the superconducting state can be significantly modified by small electric currents, much smaller than the critical current, which is potentially useful for devices involving superconducting qubits

The temporal trend of disease burden attributable to metabolic risk factors in China, 1990–2019 : An analysis of the Global Burden of Disease study

Background and aims: The disease burden attributable to metabolic risk factors is rapidly increasing in China, especially in older people. The objective of this study was to (i) estimate the pattern and trend of six metabolic risk factors and attributable causes in China from 1990 to 2019, (ii) ascertain its association with societal development, and (iii) compare the disease burden among the Group of 20 (G20) countries. Methods: The main outcome measures were disability-adjusted life-years (DALYs) and mortality (deaths) attributable to high fasting plasma glucose (HFPG), high systolic blood pressure (HSBP), high low-density lipoprotein (HLDL) cholesterol, high body-mass index (HBMI), kidney dysfunction (KDF), and low bone mineral density (LBMD). The average annual percent change (AAPC) between 1990 and 2019 was analyzed using Joinpoint regression. Results: For all six metabolic risk factors, the rate of DALYs and death increased with age, accelerating for individuals older than 60 and 70 for DALYs and death, respectively. The AAPC value in rate of DALYs and death were higher in male patients than in female patients across 20 age groups. A double-peak pattern was observed for AAPC in the rate of DALYs and death, peaking at age 20–49 and at age 70–95 plus. The age-standardized rate of DALYs increased for HBMI and LBMD, decreased for HFPG, HSBP, KDF, and remained stable for HLDL from 1990 to 2019. In terms of age-standardized rate of DALYs, there was an increasing trend of neoplasms and neurological disorders attributable to HFPG; diabetes and kidney diseases, neurological disorders, sense organ diseases, musculoskeletal disorders, neoplasms, cardiovascular diseases, digestive diseases to HBMI; unintentional injuries to LBMD; and musculoskeletal disorders to KDF. Among 19 countries of Group 20, in 2019, the age-standardized rate of DALYs and death were ranked fourth to sixth for HFPG, HSBP, and HLDL, but ranked 10th to 15th for LBMD, KDF, and HBMI, despite the number of DALYs and death ranked first to second for six metabolic risk factors. Conclusions: Population aging continuously accelerates the metabolic risk factor driven disease burden in China. Comprehensive and tight control of metabolic risk factors before 20 and 70 may help to mitigate the increasing disease burden and achieve healthy aging, respectively

Virtue perspectivism, externalism, and epistemic circularity

Virtue perspectivism is a bi-level epistemology according to which there are two grades of knowledge: animal and reflective. The exercise of reliable competences suffices to give us animal knowledge; but we can then use these same competences to gain a second-order assuring perspective, one through which we may appreciate those faculties as reliable and in doing so place our first-order (animal) knowledge in a competent second-order perspective. Virtue perspectivism has considerable theoretical power, especially when it comes to vindicating our external world knowledge against threats of scepticism and regress. Prominent critics, however, doubt whether the view ultimately hangs together without succumbing to vicious circularity. In this paper, I am going to focus on circularity-based criticisms of virtue perspectivism raised in various places by Barry Stroud, Baron Reed and Richard Fumerton, and I will argue that virtue perspectivism can ultimately withstand each of them