Entropy Generation/Availability Energy Loss Analysis Inside MIT Gas Spring and "Two Space" Test Rigs

The results of the entropy generation and availability energy loss analysis under conditions of oscillating pressure and oscillating helium gas flow in two Massachusetts Institute of Technology (MIT) test rigs piston-cylinder and piston-cylinder-heat exchanger are presented. Two solution domains, the gas spring (single-space) in the piston-cylinder test rig and the gas spring + heat exchanger (two-space) in the piston-cylinder-heat exchanger test rig are of interest. Sage and CFD-ACE+ commercial numerical codes are used to obtain 1-D and 2-D computer models, respectively, of each of the two solution domains and to simulate the oscillating gas flow and heat transfer effects in these domains. Second law analysis is used to characterize the entropy generation and availability energy losses inside the two solution domains. Internal and external entropy generation and availability energy loss results predicted by Sage and CFD-ACE+ are compared. Thermodynamic loss analysis of simple systems such as the MIT test rigs are often useful to understand some important features of complex pattern forming processes in more complex systems like the Stirling engine. This study is aimed at improving numerical codes for the prediction of thermodynamic losses via the development of a loss post-processor. The incorporation of loss post-processors in Stirling engine numerical codes will facilitate Stirling engine performance optimization. Loss analysis using entropy-generation rates due to heat and fluid flow is a relatively new technique for assessing component performance. It offers a deep insight into the flow phenomena, allows a more exact calculation of losses than is possible with traditional means involving the application of loss correlations and provides an effective tool for improving component and overall system performance

Giant simple hepatic cyst: a case report and review of relevant literature

Background: Giant cysts of the liver are uncommon. Symptoms are related primarily to the mass effect of the enlarging cyst.Objective: To highlight the challenges of management of giant simple hepatic cyst in a resource limited setting.Case report: Presented is a 58-year-old seamstress with a 5-year history of an enlarging abdominal mass with easy satiety. Surgery revealed an exophytic giant simple hepatic cyst arising from liver segment IV that drained 4.6 litres of serous fluid.Conclusion: Simple hepatic cyst can attain giant dimensions and should be considered in the differential diagnosis of intra- abdominal masses.Keywords: Laparotomy, giant hepatic cyst, drainage, wide excisio

Incidence and risk factors for caesarean wound infection in Lagos Nigeria

<p>Abstract</p> <p>Background</p> <p>Post caesarean wound infection is not only a leading cause of prolonged hospital stay but a major cause of the widespread aversion to caesarean delivery in developing countries. In order to control and prevent post caesarean wound infection in our environment there is the need to access the relative contribution of each aetiologic factor. Though some studies in our environment have identified factors associated with post caesarean wound infection, none was specifically designed to address these issues prospectively or assess the relative contribution of each of the risk factors.</p> <p>Findings</p> <p>Prospective multicentre study over a period of 56 months in Lagos Nigeria. All consecutive and consenting women scheduled for caesarean section and meeting the inclusion criteria were enrolled into the study. Cases were all subjects with post caesarean wound infection. Those without wound infection served as controls. Data entry and analysis were performed using EPI-Info programme version 6 and SPSS for windows version 10.0.</p> <p>Eight hundred and seventeen women were enrolled into the study. Seventy six (9.3%) of these cases were complicated with wound infection. The proportion of subjects with body mass index greater than 25 was significantly higher among the subjects with wound infection (51.3%) than in the subjects without wound infection (33.9%) p = 0.011. There were also significantly higher proportions of subjects with prolonged rupture of membrane (p = 0.02), prolonged operation time (p = 0.001), anaemia (p = 0.031) and multiple vaginal examinations during labour (0.021) among the women that had wound infection compared to the women that did not have wound infection. After adjustment for confounders only prolonged rupture of membrane (OR = 4.45), prolonged operation time (OR = 2.87) and body max index > 25 (2.34) retained their association with post caesarean wound infection.</p> <p>Conclusion</p> <p>Effort should be geared towards the prevention of prolonged rupture of fetal membrane and the reduction of prolonged operation time by the use of potent antibiotics, early intervention and use of good surgical technique. In obese women improved surgical technique and use of non absorbable sutures may suffice.</p

Antibiogram of nasal methicillin resistant Staphylococcus aureus (MRSA) from antenatal clinic attendees in a tertiary hospital, South-South Nigeria

The antibiogram of nasal methicillin resistant Staphylococcus aureus (MRSA) from pregnant women attending University of Uyo Teaching Hospital was investigated using standard microbiological procedures. Out of 772 women, 180(23.3%) harboured nasal MRSA while 592 (76.7%) had MSSA (Methicillin Sensitive Staphylococcus aureus). The highest frequency (33.3%) occured at week 16 while the lowest occured at week 36 of the pregnancy period. Evaluation by logistic regression showed no risk factor involvement for MRSA. The patients were evaluated on their first visit (booking) therefore the MRSA were likely community-acquired. Antibiogram of isolates showed sensitivity mostly to clindamycin (80%), amoxacillin-clavulanic acid (76.7%), ceftriazone (69.4%) and resistance to co-trimoxazole (51.7%). The asymptomatic nasal colonisation of MRSA in pregnant women may therefore be a risk factor for serious systemic infection after delivery

Combined Methanolic Leaf Extracts of Vernonia amygdalina and Gongronema latifolium Improves Sperm Parameter Impairment and Testicular Damage in STZ Induced Diabetic Wistar Rats

The effects of  methanolic leaf extracts of Vernonia amygdalina (VA) and Gongronema latifolium (GL) on the histology and DNA of the testes, and the sperm parameters of streptozocin (STZ) induced diabetic rats were investigated in this study. 18 male albino rats which were divided into three groups of six rats each were used for this work: A (Normal control) and B (Diabetic control) received tap water, C received combined extract of VA and GL, (400mg/kg twice daily, 200mg/kg each extract). Groups B &amp;C animals were induced for diabetes by intraperitoneal injection of 45mg/kg of Streptozocin, reconstituted in 0.1M sodium citrate buffer. Following sacrifice, the testes and semen were collected for histopathological studies and semen analysis respectively. The results revealed normal testes with prominent seminiferous tubules, containing germ cells at various stages of development and spermatozoa in group A. In group B, there were signs of degeneration in the seminiferous tubules (STs), destruction of germ cells, spermatozoa and Leydig cells. In group C, the testes showed normal STs with Sertoli cells, Leydig cells, germ cells and spermatozoa, suggestive of a possible regeneration. Feulgen’s reaction showed damage to the DNA of the testes in group B which was almost completely reversed in group C. Semen analysis revealed reduced sperm count, high percentage of abnormal forms and high percentage of spermatozoa with retarded motility in group B compared to group A. In group C, there was marked improvement in all the parameters. Keywords: Diabetes mellitus, sperm parameters, testicular damage, Vernonia amygdalina, Gongronema latifoliu

Influence of Long-term Ingestion of Garcinia Kola Seed Diet on Sperm Count, Sperm Motility, and Fertility in the Wistar Rat

The influence of long-term ingestion of Garcinia kola seed on the sperm count, sperm motility, and fertility was investigated in the rat. Twenty adult Wistar rats initially weighing between 150 and 160 g were randomly divided into 2 groups (A and B) of 10 rats each. Group A animals served as control and were fed normal rat feed. Group B rats were fed Garcinia kola seed diet, obtained by mixing 20g of Garcinia kola seed powder and 80g of rat feed (20% w/w). The animals were allowed their respective diets and tap water ad libitum for 8 weeks. The results obtained revealed that there was a significant difference (p&lt; 0.05) between the sperm count (16.42 × 106 ± 5.25 × 106/ml) and sperm motility(8.72 ± 2.33%) of the treatment group (Group B) and the respective values of the control, sperm count (89.38 × 106 ±  3.68 × 106/ml) and sperm motility (75.56  ±  1.23%). The findings suggest that long- term ingestion of Garcinia kola seed diet may cause a significant reduction in sperm count, sperm motility, and ultimately infertility in the male wistar rat. Keywords: Fertility; Sperm Count; Sperm Motility; Garcinia kola; Wistar rat.

Cholecystectomy: Indications at University of Calabar Teaching Hospital, Calabar, Nigeria

Background/objective: The relative rarity of gallbladder disease has been documented in various parts of Africa. Recently the incidence has been reported as rising in some African countries. We undertook this study to evaluate the indications for cholecystectomy in our center and compare with others. Methods: This is a retrospective study of 18 open cholecystectomies in 10years. Results: The ages ranged from 13 and 65 years (mean 39.2years). There were 15 females and 3 males (F: M=ratio 5:1). Calculous cholecystitis 9(50%) in patients, acalculous cholecystitis 8(44.4%) and a patient with carcinoma of the gallbladder were offered cholecystectomy. The commonest stone was mixed multiple stones. Conclusion: The numbers of cholecystectomies attest to the rarity of gallbladder disease in this environment. This may be due to the high fiber and low cholesterol diet predominant in this costal population in southern Nigeria.Introduction/Objectif: La raret\ue9 relative de la maladie de la v\ue9sicule biliaire a \ue9t\ue9 document\ue9 dans la plupart des pays africains. Jusqu'\ue0 r\ue9cemment la fr\ue9quence a \ue9t\ue9 rapport\ue9e comme en hausse dans quelques pays africains. Nous avons entrepris cette \ue9tude afin d\u2019\ue9valuer les indications de la chol\ue9cystectomie dans notre centre et les compar\ue9 avec d\u2019autres. M\ue9thodes: Il s\u2019agit d\u2019une \ue9tude r\ue9trospective de 18 chol\ue9cystectomies ouvertes au cours d\u2019une dur\ue9e de dix ans. R\ue9sultats: Les \ue2ges varient entre 13 et 65 ans (moyenne 37,2 ans.) Il y a eu 15 du sexe f\ue9minin et 3 du sexe masculin (F: M = proportion de 5:1). Chol\ue9cystites calculs de 9 soit 50% chez les patients chol\ue9cystite acalculies de 8 soit 44,4% et un patient atteint d\u2019un cancer de la v\ue9sicule biliaire a \ue9t\ue9 donn\ue9 la chol\ue9cystectomie. Un mixte de multiples pierres \ue9tait la pierre la plus fr\ue9quente. Conclusion: Le nombre des chol\ue9cystectomies confirme la raret\ue9 de la maladie v\ue9siculaire dans cet environnement. Cela peut \ueatre du \ue0 la haute teneur en fibres et faible taux de cholest\ue9rol alimentaire pr\ue9dominant dans cette population costale dans le sud du Nig\ue9ria

Students' awareness, willingness and utilisation of facebook for research data collection: Multigroup analysis with age and gender as control variables

Previous research has extensively analysed teachers' and students' Facebook use for instructional engagement, writing, research dissemination and e-learning. However, Facebook as a data collection mechanism for research has scarcely been the subject of previous studies. The current study addressed these gaps by analysing students' awareness, willingness, and utilisation of Facebook for research data collection [RDC]. This study aimed to predict students’ Facebook use for research data collection based on their awareness and willingness and to determine age and gender differences in such predictions. A sample of 11,562 students of tertiary institutions participated in an online survey. The researchers designed and validated the online survey. Exploratory Factor Analysis was used for dimensionality. Average Variance Extracted [AVE] was used for convergent validity, whilst the Fornel-Larcker criterion and Heterotrait-Monotrait ratio were used for discriminant validity. Composite reliability indices of .97, .94 and .90 proved the instrument’s three sub-scales usable. One sample t-test and multigroup analysis were conducted using SPSS 27 and Smart PLS 3. The study found high awareness but low usage of Facebook for RDC among Nigerian university students. Younger and male students showed higher willingness and actual use of Facebook for RDC. Awareness directly impacted by awareness, and acted as Facebook usage for RDC, with stronger impacts for males and students aged 19 to 28. Willingness was positively impacted and acted as a negative mediator between awareness and usage for some age groups and genders. These findings provide important insights into using Facebook for RDC among students in Nigerian universities and highlight the need to consider the impact of demographic factors such as age and gender when promoting social media platforms for academic purposes

Diagnostic accuracy of a clinical diagnosis of idiopathic pulmonary fibrosis: An international case-cohort study

We conducted an international study of idiopathic pulmonary fibrosis (IPF) diagnosis among a large group of physicians and compared their diagnostic performance to a panel of IPF experts. A total of 1141 respiratory physicians and 34 IPF experts participated. Participants evaluated 60 cases of interstitial lung disease (ILD) without interdisciplinary consultation. Diagnostic agreement was measured using the weighted kappa coefficient (\u3baw). Prognostic discrimination between IPF and other ILDs was used to validate diagnostic accuracy for first-choice diagnoses of IPF and were compared using the Cindex. A total of 404 physicians completed the study. Agreement for IPF diagnosis was higher among expert physicians (\u3baw=0.65, IQR 0.53-0.72, p20 years of experience (C-index=0.72, IQR 0.0-0.73, p=0.229) and non-university hospital physicians with more than 20 years of experience, attending weekly MDT meetings (C-index=0.72, IQR 0.70-0.72, p=0.052), did not differ significantly (p=0.229 and p=0.052 respectively) from the expert panel (C-index=0.74 IQR 0.72-0.75). Experienced respiratory physicians at university-based institutions diagnose IPF with similar prognostic accuracy to IPF experts. Regular MDT meeting attendance improves the prognostic accuracy of experienced non-university practitioners to levels achieved by IPF experts

Marine Tar Residues: a Review

Abstract Marine tar residues originate from natural and anthropogenic oil releases into the ocean environment and are formed after liquid petroleum is transformed by weathering, sedimentation, and other processes. Tar balls, tar mats, and tar patties are common examples of marine tar residues and can range in size from millimeters in diameter (tar balls) to several meters in length and width (tar mats). These residues can remain in the ocean envi-ronment indefinitely, decomposing or becoming buried in the sea floor. However, in many cases, they are transported ashore via currents and waves where they pose a concern to coastal recreation activities, the seafood industry and may have negative effects on wildlife. This review summarizes the current state of knowledge on marine tar residue formation, transport, degradation, and distribution. Methods of detection and removal of marine tar residues and their possible ecological effects are discussed, in addition to topics of marine tar research that warrant further investigation. Emphasis is placed on ben-thic tar residues, with a focus on the remnants of the Deepwater Horizon oil spill in particular, which are still affecting the northern Gulf of Mexico shores years after the leaking submarine well was capped