Preliminary Evaluation of the Capacity of Surface-Active Phospholipids to Provide Semipermeability in a Saline Filtration Environment

Background: Semipermeability to fluid transport is one of the principal attributes of a tissue like articular cartilage. Consequently, this characteristic can be exploited in attempts to understand the functional roles of the biological layer of Surface Active Phospholipids (SAPL) which form on its surfaces. A previous study, relevant to peritoneal SAPL was carried out in which hypertonic glucose solution was dialysed against physiological saline through SAPL membrane and concluded that SAPL possessed semipermeability. Our analysis extends this previous study by dialysing hypertonic and hypotonic saline solutions against physiological saline via SAPL membranes which is more relevant to the articular joint environment. Material and Methods: Membranes were produced from either synthetic or bovine cartilage SAPL and used to carry out tests involving the dialysis of hypotonic and hypertonic sodium chloride solutions against physiological saline, using an Ussing chamber to hold both the membranes and dialysis fluids. Results: The dialysis produced osmotic pressures which are commensurate with our experimental constraints, but strongly indicated that it is indeed possible to generated osmotic pressures using SAPL membranes, indicating the semipermeability of this lipid structure. Conclusion: It is widely accepted that the collagen-proteoglycan membrane provides the semipermeability of articular despite the low levels of osmotic pressure recorded in our experiments, our results demonstrate that SAPL aggregation can constitute a semipermeable layer with a strong capability to contribute to the semipermeablity of the collagen-proteoglycan system especially on the surface of the tissue. Consequently its deficiency, as seen in osteoarthritis could lead/contribute to cartilage dysfunction

Optical non-destructive evaluation of articular cartilage integrity: A review

This paper reviews the current status of the application of optical non-destructive methods, particularly infrared (IR) and near infrared (NIR), in the evaluation of the physiological integrity of articular cartilage. It is concluded that a significant amount of work is still required in order to achieve specificity and clinical applicability of these methods in the assessment and treatment of dysfunctional articular joints

Preliminary characterisation of the surface of cartilage following exposure to saturated and unsaturated synthetic lips

Articular cartilage is covered by a microscopic structure known as surface amorphous layer. This surface structure is often the first victim of attack during cartilage degeneration, thereby resulting in a gross impairment in cartilage function such as lubrication and load bearing. We hypothesize that incubation of degraded cartilage in solutions of different species of synthetic surface active phospholipids (saturated and unsaturated species) can remodel this lost surface structure. To test this hypothesis, the structural configuration of the surface of articular cartilage was studied and characterised with the lipid filled surface amorphous layer intact using the AFM. The results were then compared with those obtained following a systematic removal (delipidization) and replacement (relipidization) of this layer. Our results show that the unsaturated surfactant partially restored the lost surface amorphous layer while the saturated surfactant specie settled on the surface due to its poor solubility in aqueous solution

Occupants’ adaptation and design parameters influencing behavioural actions of occupants in naturally ventilated sustainable timber buildings

Existing studies have examined occupants’ adaptation and various parameters affecting thermal comfort of occupants in different buildings. However, there are limited studies that have examined occupants’ adaptation and design parameters in naturally ventilated sustainable buildings, especially structural timber buildings. As a result, this study considers a comparative analysis of occupants’ adaptation and examines various design parameters influencing behavioural actions of occupants in naturally ventilated structural timber buildings. The study evaluates indoor spaces of two dwelling units in each of the two sustainable timber case study buildings located in Western Europe. The research employed analysis of architectural design of the buildings, on-site measurements, and a thermal comfort survey. The parameters measured during the on-site survey include temperature and relative humidity at one hour intervals for twelve days during the summer period. The findings were compared with design parameters such as natural ventilation, size of opening, floor-to-ceiling height, and floor area of the spaces. The results showed more than 85% of the occupants in dwelling units with smaller floor area tend to adapt better to the thermal environment than those living in dwelling units with bigger floor area. It appears that at least 75% of the occupants in spaces with natural cross-ventilation tend to be more thermally satisfied than occupants in spaces with single-sided ventilation. The findings also revealed the risk of summertime overheating tends to be significantly reduced (p<0.05) when spaces have natural cross-ventilation, higher floor-to-ceiling height, and a larger floor area. Finally, the results showed the adaptation of occupants in naturally ventilated buildings and the ability to use control to adjust the thermal environment and reduce the overall annual energy consumption in sustainable buildings. Keywords: architectural design, comparative study, occupants’ adaptation, design parameters, behavioural actions, naturally ventilated sustainable timber building

Near-infrared (NIR) spectroscopic evaluation of articular cartilage: A review of current and future trends

This review describes recent developments and applications of near-infrared (NIR) spectroscopy for characterization of articular cartilage integrity. It summarizes the research findings in this area and presents some spectral ranges and peaks associated with the different properties and components of articular cartilage. We further describe recent adaptations of NIR spectroscopy for clinical evaluation of articular cartilage injury and degeneration. Critical to accurate decision-making during repair surgery is having clear knowledge of lesion severity and spread, and how to grade the quality of surrounding cartilage. Thus, in this review, we detail efforts aimed at quantification and classification of cartilage pathology using NIR spectroscopy. Finally, we present open questions and challenges with a view to guiding future directions in NIR spectroscopy research on articular cartilage

The Effect of Computer Simulation on Student Performance in High School Chemistry Learning on Chemical Equations

Chemical equations have been identified as a complicated topic in the Nigerian School Certificate. This study investigates the effect of computer simulations on student performance in high school chemistry courses on the topic of chemical equations in Offa, Nigeria. This study adopted a quasi-experimental research design with a pre-test, post-test, and non-randomized control group. The population is all high school students totaling 756 students. The sample was selected purposively, namely 136 students. Chemical Equation Performance Test (CEPT), Online Computer Simulation of Chemical Equations (OCSCE), and Cognitive Force Checklist (CSC) with reliability coefficients of 0.76, 0.81, and 0.78, respectively, were used as instruments for the study. The results of this study are that there are differences in the performance of students who are taught using computer simulations, between the performance of male and female students, and differences in performance between students who score low, medium, and high. It was concluded that computer simulation affected the performance of high school students. It was supposed that computer simulation affected the performance of high school students. It is recommended that future researchers apply computer simulations to other learning

Ethnomedicinal Uses and Therapeutic Activities of Piper Guineense: A Review

The use of medicinal plants in most developing countries as therapeutic agents for the maintenance of good health is a widespread practice. One of such plant products is Piper guineense, which is a West African spice used in many folklore medicines and has a number of verified pharmacological activities. Proximate analysis reveals that the plant contains crude protein, fat, carbohydrate, vitamins and minerals while preliminary phytochemical screening and gas chromatography-mass spectrophotoscopy of the methanol leaf and seed extract of Piper guineense revealed the presence of several constituents such as alkaloids, glycosides, tannins, flavonoids, terpenes; sesquiterpenoids and monoterpenoids, saponins and secondary metabolites such as Aromadendrene, 1,6,10- Dodecatriene,7,11-dimethyl-3-methylene and piperine, piperidine amongst other secondary metabolites. Studies have revealed that Piper guineense possess several pharmacological and therapeutic properties such as anti-oxidant, anti-microbial, aphrodisiac, anti-parasitic, antiinflammatory, anti-convulsant, molluscicidal, oestrogenic and oxytocic properties. This paper provides a review on the morphology, physicochemical and phytochemical constituents, ethnomedicinal and scientifically proven therapeutic activities of Piper guineense

Percepção local sobre os impactos da conservação da biodiversidade nas atividades de subsistência no parque nacional de Old Oyo, Nigéria

The study examined the socio-economic activities of rural communities in Old Oyo National Park and their perception towards conservation. Ten villages were randomly chosen from the five ranges based on their proximity to the park. A total of one hundred and fifty-two (152) structured questionnaire were administered to obtain information from the local community. The questionnaire was designed to elicit information on the livelihood practices and the impacts of the park on their livelihoods. Data obtained were analyzed using descriptive statistics and inferential statistics. The major occupations of the respondents around the park were farming (25.7%), trading (22.4%), Artisan (19.1%), and Students (12.5%). The results showed that the majority of the respondents were male (69.1%) while 31.9% were female. Many of the respondents (39.5%) experience a loss of right/control over protected resources. The result further revealed that the respondents (28.9%) experienced the loss of traditional access to the park, with  serious impact on the livelihood of the respondents. Chi-square analysis showed that there is an association between gender (χ2 = 1.857 p&lt;0.05)  and perceived access to natural resources. The result further showed a significant relationship between the respondents’ perceived access to the park-related resources and their marital status (χ2 = 10.184 p&lt;0.001), indicating that marital status positively affected their perception of the park resources. It is, therefore, recommended that there should be training on alternative sources of livelihood and also sensitize the communities about the needs for conservation.O estudo examinou as atividades socioeconômicas das comunidades rurais no Parque Nacional Old Oyo e sua percepção em relação à conservação. Dez aldeias foram escolhidas aleatoriamente das cinco faixas com base em sua proximidade com o parque. Um total de cento e cinquenta e dois (152) questionários estruturados foram aplicados para obter informações da comunidade local. O questionário foi elaborado para obter informações sobre as práticas de subsistência e os impactos do parque em seus meios de subsistência. Os dados obtidos foram analisados ​​por meio de estatística descritiva e estatística inferencial. As principais ocupações dos entrevistados no entorno do parque foram agricultura (25,7%), comércio (22,4%), artesão (19,1%) e estudantes (12,5%). Os resultados mostraram que a maioria dos respondentes era do sexo masculino (69,1%) e 31,9% do sexo feminino. Muitos dos entrevistados (39,5%) experimentam uma perda de direito/controle sobre os recursos protegidos. O resultado revelou ainda que os entrevistados (28,9%) vivenciaram a perda do acesso tradicional ao parque, com sério impacto na subsistência dos entrevistados. A análise do qui-quadrado mostrou que há associação entre sexo (χ2 = 1,857 p&lt;0,05) e percepção de acesso aos recursos naturais. O resultado mostrou ainda uma relação significativa entre o acesso percebido dos entrevistados aos recursos relacionados ao parque e seu estado civil (χ2 = 10,184 p&lt;0,001), indicando que o estado civil afetou positivamente sua percepção dos recursos do parque. Recomenda-se, portanto, que haja treinamento sobre fontes alternativas de subsistência e também sensibilize as comunidades sobre as necessidades de conservação

Unsaturated phosphatidylcholines lining on the surface of cartilage and its possible physiological roles

Background Evidence has strongly indicated that surface-active phospholipid (SAPL), or surfactant, lines the surface of cartilage and serves as a lubricating agent. Previous clinical study showed that a saturated phosphatidylcholine (SPC), dipalmitoyl-phosphatidylcholine (DPPC), was effective in the treatment of osteoarthritis, however recent studies suggested that the dominant SAPL species at some sites outside the lung are not SPC, rather, are unsaturated phosphatidylcholine (USPC). Some of these USPC have been proven to be good boundary lubricants by our previous study, implicating their possible important physiological roles in joint if their existence can be confirmed. So far, no study has been conducted to identify the whole molecule species of different phosphatidylcholine (PC) classes on the surface of cartilage. In this study we identified the dominant PC molecule species on the surface of cartilage. We also confirmed that some of these PC species possess a property of semipermeability. Methods HPLC was used to analyse the PC profile of bovine cartilage samples and comparisons of DPPC and USPC were carried out through semipermeability tests. Results It was confirmed that USPC are the dominant SAPL species on the surface of cartilage. In particular, they are Dilinoleoyl-phosphatidylcholine (DLPC), Palmitoyl-linoleoyl-phosphatidylcholine, (PLPC), Palmitoyl-oleoyl-phosphatidylcholine (POPC) and Stearoyl-linoleoyl-phosphatidylcholine (SLPC). The relative content of DPPC (a SPC) was only 8%. Two USPC, PLPC and POPC, were capable of generating osmotic pressure that is equivalent to that by DPPC. Conclusion The results from the current study confirm vigorously that USPC is the endogenous species inside the joint as against DPPC thereby confirming once again that USPC, and not SPC, characterizes the PC species distribution at non-lung sites of the body. USPC not only has better anti-friction and lubrication properties than DPPC, they also possess a level of semipermeability that is equivalent to DPPC. We therefore hypothesize that USPC can constitute a possible addition or alternative to the current commercially available viscosupplementation products for the prevention and treatment of osteoarthritis in the future

Conceptual Fracture Parameters for Articular Cartilage

Background: Superficial cracks can occur in articular cartilage due to trauma or wear and tear. Our understanding of the behaviour of such cracks in a loaded matrix is limited. A notable study investigated the growth of cracks induced in the bottom layer of the matrix. This paper extends existing studies, characterizing the propagation of superficial cracks and matrix resistance under tension at varying rates of loading. Methods: Cartilage strips with artificially induced superficial cracks were subjected to tensile loading at different loading velocities using a miniature tensile testing device. Load-displacement data, video and still images were recorded for analysis. Findings: The propagation of superficial cracks in articular cartilage does not follow the classical crack tip advance that is characteristic of most engineering materials. Instead, the crack tip exhibited a negligible movement while the side edges of the crack rotated about it, accompanied by matrix stretching and an upward pull (necking) of the bottom layer of the sample. As loading progresses, the crack edges stretch and rotate to assume a position parallel to the articular surface, followed by the final fracture of the matrix at a point just below the crack tip. Using the recorded mechanical data and images, an analogous poroelastic fracture toughness, KpIC = 1.83 MPa. (SD 0.8) is introduced. Interpretation: It is extremely difficult for a superficial crack to propagate through articular cartilage. This may be because of the energy dissipation from the crack due to the movement and exudation of water, and large stretching of the matrix