The Histological effects of microwave oven on bone decalcification using gooding and stewart fluid at varying temperatures and concentrations

This study evaluates the histological preservation of bone tissue architecture at varying temperatures and concentrations of Gooding and Stewart (GS) decalcifying fluid as the preservation of tissue architecture depends on the quality and velocity of the decalcification processes. In the present study, a decalcification methodology was adopted using household microwave oven to induce the decalcification rate of rabbit compact bone sample for microscopic analysis. Bone biopsy was obtained from rabbit limb and fixed immediately for 24hrs in 10% formalin. Traditional decalcification was carried out at RT (Room Temperature) with 5%-GS as control while microwave oven decalcification was conducted with 5%-GS and 10%-GS at 300C, 400C and 500C respectively. The results showed that 5%-GS and 10%-GS gave excellent histological architecture at 300C while at 400C, the histological architectures were comparable to RT decalcification. But at 500C, bone tissue architecture was completely destroyed being ghost-like in appearance. Of particular interest is the fact that the bone tissue treated with 5%-GS irrespective of the temperature presented excellent tissue architecture than that of 10%-GS. Thus 5%-GS gave the best result in this study.Key Words: Microwave Oven, Decalcification, Decalcifying fluid, Tissue architecture

Sub acute and chronic effects of Carica Papaya on the kidney of rats

This study investigates the sub-acute and chronic effects of Carica papaya on the kidney of growing Sprague Dawley rats. A total 40 growing rats (95.0 ± 10.0 grams) within the ages of 7 ± 1weeks were involved in the study. They were divided into eight groups of 5 rats each: A (control; n = 5), B (n = 10), C (n = 10) and D (n = 10). Group A1 and A2 served as the acute and chronic control respectively. Group B1, C1 and D1 served as the subacute test while group B2, C2 and D2 served as the chronic test. The rats received varied doses of powdered Carica papaya seed (6, 8, 10grams). Group A1, B1, C1 and D1 were fed for 3 weeks while Group A2, B2, C2 and D2 were fed for 6 weeks. At the end of each stage, animals were sacrificed and the kidneys were harvested for histological study. The results showed histological distortions in the liver parenchymal architecture in a dose and duration dependent manner. Our findings suggest therefore, that Carica papaya seeds have nephrotoxic potentials and as such, the need for further studies cannot be overemphasized.Key words: Carica papaya seed, Herb, Sub-acute, Chronic, Nephrotoxic

The Role of the st313-td Gene in Virulence of Salmonella Typhimurium ST313

Multidrug-resistant Salmonella enterica serovar Typhimurium ST313 has emerged in sub-Saharan Africa causing severe infections in humans. Therefore, it has been speculated that this specific sequence type, ST313, carries factors associated with increased pathogenicity. We assessed the role in virulence of a gene with a yet unknown function, st313-td, detected in ST313 through comparative genomics. Additionally, the structure of the genomic island ST313-GI, harbouring the gene was determined. The gene st313-td was cloned into wild type S. Typhimurium 4/74 (4/74-C) as well as knocked out in S. Typhimurium ST313 02-03/002 (Δst313-td) followed by complementation (02-03/002-C). Δst313-td was less virulent in mice following i.p. challenge than the wild type and this phenotype could be partly complemented in trans, indicating that st313-td plays a role during systemic infection. The gene st313-td was shown not to affect invasion of cultured epithelial cells, while the absence of the gene significantly affects uptake and intracellular survival within macrophages. The gene st313-td was proven to be strongly associated to invasiveness, harboured by 92.5% of S. Typhimurium blood isolates (n = 82) and 100% of S. Dublin strains (n = 50) analysed. On the contrary, S. Typhimurium isolates of animal and food origin (n = 82) did not carry st313-td. Six human, non-blood isolates of S. Typhimurium from Belarus, China and Nepal harboured the gene and belonged to sequence types ST398 and ST19. Our data showed a global presence of the st313-td gene and in other sequence types than ST313. The gene st313-td was shown to be expressed during logarithmic phase of growth in 14 selected Salmonella strains carrying the gene. This study reveals that st313-td plays a role in S. Typhimurium ST313 pathogenesis and adds another chapter to understanding of the virulence of S. Typhimurium and in particular of the emerging sequence type ST313

Outlook for inverse design in nanophotonics

Recent advancements in computational inverse design have begun to reshape the landscape of structures and techniques available to nanophotonics. Here, we outline a cross section of key developments at the intersection of these two fields: moving from a recap of foundational results to motivation of emerging applications in nonlinear, topological, near-field and on-chip optics.Comment: 13 pages, 6 figure

The Human Sweet Tooth

Humans love the taste of sugar and the word "sweet" is used to describe not only this basic taste quality but also something that is desirable or pleasurable, e.g., la dolce vita. Although sugar or sweetened foods are generally among the most preferred choices, not everyone likes sugar, especially at high concentrations. The focus of my group's research is to understand why some people have a sweet tooth and others do not. We have used genetic and molecular techniques in humans, rats, mice, cats and primates to understand the origins of sweet taste perception. Our studies demonstrate that there are two sweet receptor genes (TAS1R2 and TAS1R3), and alleles of one of the two genes predict the avidity with which some mammals drink sweet solutions. We also find a relationship between sweet and bitter perception. Children who are genetically more sensitive to bitter compounds report that very sweet solutions are more pleasant and they prefer sweet carbonated beverages more than milk, relative to less bitter-sensitive peers. Overall, people differ in their ability to perceive the basic tastes, and particular constellations of genes and experience may drive some people, but not others, toward a caries-inducing sweet diet. Future studies will be designed to understand how a genetic preference for sweet food and drink might contribute to the development of dental caries

Variations in some morphological and yield characteristics of mungbean (Vigna radiata (L.) Wilczek) cultivars introduced into the rain-forest agroecology of Southeastern Nigeria

In an effort to increase the legume base of the people, mungbean (Vigna radiata (L) Wilczek) was introduced into the agro-ecology of southeastern Nigeria. During a field evaluation of mungbean cultivars at Michael Okpara University of Agriculture, Umudike, Nigeria, nine (9) plants were observed to differ in some vegetative and reproductive traits. The plants were consequently protected and their seeds harvested for further investigations. The progenies of the 9 genotypes and 2 mungbean cultivars (NM-92 and NM-94) were further evaluated in the screen house at the Federal University of Technology, Owerri, Nigeria. Data on the peduncle and vine lengths, days to 50 % anthesis, growth period, pod maturity period, pod length, number of seeds pod-1, number of pods plant-1 and 100 seed weight and subjected to analysis of variance using the unbalanced treatment procedure. In terms of the morphological characteristics, variation can be said to have occurred with regards to: growth habit (length of vine), vine hairiness, petal and seed coat colours. Results however show that Genotype-6 and Genotype-8 resemble the NM-92 and NM-94 cultivars in nearly all the attributes measured. Variations among the cultivars have also been observed in the aspects of: podyield per plant, pod and peduncle lengths, seed weight (g/100 seeds) and number of seeds per pod. Further studies are however ongoing to establish the genetic evidence of this phenotypic differences

Development of an uninterrupted solar powered traffic light from locally accessed materials

Advances in transport technology have brought benefits, but growing vehicular traffic and increased fossil fuel use have created problems. In view of these, the need to address the shortage of important infrastructures such as traffic light systems in most cities of Nigeria is imperative. This paper aims at designing, constructing and testing an uninterrupted solar powered traffic light that could operate at a T-junction to reduce traffic jam and risks around the area. The design made use of an Atmel series of 89S51 Microcontroller Unit (MCU), a Vero board, resistors, transistors, diodes, capacitors, Light Emitting Diodes (LED) and battery charged with a solar powered photovoltaic module. The testing of the traffic light was carried out at the pre-implementation and post-implementation stages of the construction as well as subsequent tests carried out on the complete system for precision.Keywords: Traffic light systems, vehicular traffic, fossil fuel, solar photovoltaic International Journal of Natural and Applied Sciences, 6(4): 482 - 487, 201