Scientific Research Publishing

Citric acid (2-hydroxypropane-1,2,3-tricarboxylic acid) is a tricarboxylic acid, naturally presents in several fruits, vegetables, and in the milk. Commercially, citric acid is usually found as a white crystalline solid and it has several industrial applications. This acid is widely used in food and pharmaceutical industries because of its various functions, such as acidulant, food preservative, chelating agent, carbonic gas fixer, humectant, emollient, and others. In this work, the authors aimed at the study of citric acid solvent extraction in order to establish the composition of the organic phase and to obtain thermodynamic and kinetic data for the chosen system. Discontinuous extraction experiments in a single stage were performed from a synthetic solution of citric acid, with the typical concentration (10% w/v) observed in industrial fermented musts. Exploratory experiments were carried out by using different organic phases in order to select the most suitable solvent phase ...

One of the leading causes of disability in the elderly is the pain associated with knee osteoarthritis (OA). Chronic pain from knee OA can decrease physical activity, increasing the risk for chronic disease, decreased functional independence and diminished quality of life. In spite of the increased prevalence of knee OA in women, there has been limited investigation into the factors underlying the sex disparity of knee OA. And urinary estradiol (E2) metabolites were shown to be associated with the incidence of knee OA in perimenopausal women. In this paper, the authors aimed to determine the associations between urinary estradiol (E 2 ) metabolite concentration and medial knee loading with radiographic disease severity in middle aged women with initial stage knee osteoarthritis (OA). Women presenting with knee pain were recruited into a cross-sectional correlation study (KOA, n = 9, age = 52 ± 4 yrs). Self-report menstrual history, the Modified Baecke Questionnaire and the Knee In...

A large amount of Municipal Solid Waste (MSW) in Africa still piles up on the spot, in trenches, ditches, riverbanks and roadsides, the waste burns in open air or drift by the river flow or the heavy rains. The consequences are air pollution, contamination of soil, groundwater, and rivers. Matadi is the capital of the province Congo Central situated in the bank of the Congo River, where there is also a large amount of MSW. In this article, the authors aimed to present the key elements for the best performance and profitability of Municipal Solid Waste (MSW) management in low-income cities and presented a case study of Matadi. The research provided an overview of methods and models for integrated planning of a two-phase program: MSW collection and transportation, and MSW treatment. The authors presented the case study of Matadi (the Democratic Republic of Congo) that had a low level of the MSW management compared to other African cities. And they developed a spreadsheet model for ...

Polo-like kinase 1 (PLK1) is a serine/threonine kinase that plays critical roles in cell cycling and DNA damage response. Overexpression of PLK1 is associated with the poorer prognosis of cancers, including colorectal cancer (CRC). Although the downstream pathways of the overexpression that lead to oncogenesis have been extensively studied, little is known about the factors that cause the overexpression of PLK1 in CRC. DNA methylation was reported to be affecting the expression of PLK1 in some cancers. This study aimed to investigate the contribution of genetic mutation and DNA methylation of the PLK1 gene to the overexpression of PLK1 in CRC. The study involved data mining from Catalogue of Somatic Mutations in Cancer (COSMIC) and UniProtKB, Sanger sequencing on DNA from the cell lines HCT116, SW48, Colo320DM and T84 to analyze the possible mutation of PLK1. Other than that methylation status of the PLK1 promoter in CRC were also analyzed by using mass spectrometry (MS) and pyros...

PE class has been recognized as an ideal environment in school to develop students’ social skills. However, there were few studies conducted to examine the effects of college students’ sport experiences on their social skills in PE classes. In this study, the authors investigated the influences of sport experiences on social skills among Chinese college students in physical education (PE) classes. First, the authors tested the reliability and validity of the Chinese version of the Experience Scale in University Physical Education Classes (ESUPEC) for examining Chinese college students’ sport experiences in PE classes. Students ( n  = 366, 194 males, 172 females, mean age = 18.6 years old) from two universities in China completed a survey by using the Chinese version of ESUPEC. And the results of factor analyses and reliability analyses indicated that the structure of the scale was consistent with the original version of ESUPEC, and the reliability and validity of the scale wer...

Human papilloma virus (HPVs) being the most common sexually transmitted infection worldwide is studied and taken more interest. In this study, the authors aimed to evaluate the sensitivity and accuracy of the HPV DNA test in conjunction with thin prep cytology test as a screening method of human papilloma virus (HPV) infection. The study was a retrospective cohort implemented to determine the real performance of liquid based medium and HPV DNA testing combined in second clinical hospital of Jilin University Changchun, China. The study group included total 150 patients from January 1, 2011 to December 30, 2012. A computerized search identified patients with thin prep test results and high risk HPV DNA testing during a 2-year period was recruited. The patients were chosen after proper speculum examination followed by thin prep cytology (TCT) and HPV DNA test. Cytologic specimens were obtained with endocervical brush, which was rinsed into the vial of Cytyc. The residual samples afte...

In recent days, the multilevel inverter technology is widely applied to domestic and industrial applications for medium voltage conversion. But the power quality issues of the multilevel inverter limit the usage of much sensitive equipment like medical instruments. The lower distortion level of the output voltage and current can generate a quality sinusoidal output voltage in inverters and they can be used for many applications. The harmonics can cause major problems in equipment due to the nonlinear loads connected with the power system. So, it is necessary to minimize the losses to raise its overall efficiency. In this paper, a new topology of seven-level asymmetrical cascaded H-bridge multilevel inverter with a fuzzy logic controller had been implemented to reduce the Total Harmonic Distortion (THD) and to improve the overall performance of the inverter. The proposed model was well suited for use with a solar PV application. In this topology, only six IGBT switches were used w...