326 research outputs found

    Corrosion Fatigue Crack Growth Behavior At Notched Hole In 7075-T6 Under Different Biaxial Stress Ratios

    Get PDF
    This thesis presents the results of a study to quantify the effects of biaxial loading on fatigue crack behavior in both air and saltwater (3.5% NaCl) environments from pre-cracked notched circular hole in a 7075-T6 cruciform specimen using a fracture mechanics approach. With stress ratio of R = 0.5, the crack growth behavior was investigated under fatigue loading with 0.5, 0, -0.5, and -1 biaxial stress ratio lambda. The crack propagation was monitored using optical microscopy. Finite Element Analysis was performed using the different stress ranges and stress ratios with various crack sizes to compute of stress intensity factors (delta K) at the crack tips. It was observed from the study that negative biaxiality has a very pronounced effect on the crack growth rate. The crack propagates faster with negative biaxiality and also the saltwater environment accelerates the crack propagation due to corrosion

    Evolving standards of information disclosure: Reform of Saudi Arabian medical law in the light of the developments of English law

    Get PDF
    Abstract The major concern of this thesis is about the current professional standard of care under Saudi Arabian medical law, regarding doctors’ duty to disclose information and risks to competent adult patients about a proposed medical treatment. Additionally, the thesis has highlighted other legal deficiencies that occur as a result of applying the professional standard in Saudi Arabia and considered how reforms can be introduced, based on English law experience in a way that is in harmony with Islamic Sharia. The thesis has undertaken a novel approach by critically studying and comparing the current practice in Saudi Arabian medical law to the comparative English law approach. The reason for this is to provide a comprehensive legal literature review based on the extremely well- developed English law experiences in the same matters. Realising the significance of the principle of the respect for autonomy, the thesis has placed a noticeable emphasis on this principle by arguing that considering and respecting autonomy would lead the law to protect the patient’s autonomy and self-determination in a medical context. The thesis has argued that both Western and Islamic Sharia medical ethics have considered the notion of the respect for patients’ autonomy, but that consideration has been approached differently, as the thesis has shown. Further, the thesis has critically discussed how the English law standard of care has been developed in the last three decades, in order to move from the professional standard of care to a new standard that protects patients’ autonomy and self-determination. These developments and years of experience have provided sufficient arguments and supports for the thesis’s motion to recommend and suggest that Saudi Arabian medical law departs from the professional standard and adopts the prudent patient standard to protect patients’ autonomy in compliance with Islamic Sharia. In addition to proposing a legal formula for the prudent patient standard that can be adopted by Saudi Arabian medical law, this thesis has also proposed other formulas as solutions for other legal deficiencies, based on English law experience and in accordance with Islamic Sharia

    A comparative study of the effects of different low-level lasers on the proliferation, viability, and migration of human melanocytes in vitro.

    Get PDF
    The aim of this study was to investigate the effects of different low-level laser therapies (LLLTs) of various wavelengths and energies on normal cultured human melanocytes. Various studies have shown the effects of LLLs on various types of cultured cells. Presently, little is known about the biological effects of LLLTs on melanocytes. Melanocytes were exposed to LLLT at 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 J/cm(2) using a blue (457 nm), red (635 nm), or ultraviolet (UV) (355 nm) laser. Melanocyte viability, proliferation, and migration were monitored at 72 h after irradiation. The blue (P < 0.001) and red (P < 0.001 and P < 0.01) lasers significantly enhanced viability at 0.5 to 2.0 J/cm(2), whereas the UV laser (P < 0.001) could significantly enhance viability only at 0.5 and 1.0 J/cm(2) compared with controls. The blue and red lasers also significantly enhanced the proliferation of the melanocytes at 0.5 to 2.0 J/cm(2) (P < 0.001), and the UV laser significantly enhanced proliferation at 0.5 to 1.5 J/cm(2) (P < 0.001 and P < 0.01) compared with controls. The blue laser significantly enhanced melanocyte migration at 0.5 to 4.0 J/cm(2) (P < 0.001 to P < 0.05), but the red (P < 0.001 and P < 0.01) and UV (P < 0.001 to P < 0.05) lasers could significantly enhance such migration at 0.5 to 1.0 J/cm(2) and 0.5 to 2.0 J/cm(2), respectively, compared with controls. LLLT at low energy densities is able to significantly increase melanocyte viability, proliferation, and migration in vitro, and at higher energy densities, it gives non-stimulatory results. Additionally, the blue laser was the best among the three lasers. These findings might have potential application in vitiligo treatment in future

    Semantic Web Service Engineering: Annotation Based Approach

    Get PDF
    Web services are an emerging paradigm which aims at implementing software components in the Web. They are based on syntactic standards, notably WSDL. Semantic annotation of Web services provides better qualitative and scalable solutions to the areas of service interoperation, service discovery, service composition and process orchestration. Manual annotation is a time-consuming process which requires deep domain knowledge and consistency of interpretation within annotation teams. Therefore, we propose an approach for semi-automatically annotating WSDL Web services descriptions. This is allowed by Semantic Web Service Engineering. The annotation approach consists of two main processes: categorization and matching. Categorization process consists in classifying WSDL service description to its corresponding domain. Matching process consists in mapping WSDL entities to pre-existing domain ontology. Both categorization and matching rely on ontology matching techniques. A tool has been developed and some experiments have been carried out to evaluate the proposed approach

    Htab2RDF: Mapping HTML Tables to RDF Triples

    Get PDF
    The Web has become a tremendously huge data source hidden under linked documents. A significant number of Web documents include HTML tables generated dynamically from relational databases. Often, there is no direct public access to the databases themselves. On the other hand, RDF (Resource Description Framework) gives an efficient mechanism to represent directly data on the Web based on a Web-scalable architecture for identification and interpretation of terms. This leads to the concept of Linked Data on the Web. To allow direct access to data on the Web as Linked Data, we propose in this paper an approach to transform HTML tables into RDF triples. It consists of three main phases: refining, pre-treatment and mapping. The whole process is assisted by a domain ontology and the WordNet lexical database. A tool called Htab2RDF has been implemented. Experiments have been carried out to evaluate and show efficiency of the proposed approach

    Orofacial Development Changes in Children Following Cancer Treatment: A Comprehensive Review of Literature and Analysis of Current Data in Leeds Dental Institute.

    Get PDF
    Introduction: Childhood cancer survivors often experience various side effects after treatment, including dental and orofacial developmental conditions. According to the literature, the treatment for cancer in children can affect the development of teeth, the function of salivary glands, the development of facial structures, and the operation of the temporomandibular joint [TMJ]. Leeds Dental Institute [LDI] has accumulated a wealth of data while providing dental healthcare for cancer survivors. This extensive data has not been thoroughly explored or published. Thus, this study aims to investigate the long-term effects of cancer treatment on dental and orofacial structures from the literature and the available records in children at Leeds Dental Institute. Methods: This research is structured into two sections. The first is a comprehensive literature review of existing studies on the adverse effects of cancer treatments on oral and facial structures in children by searching six databases to establish a foundation for understanding the broader context of the issue. The second section is a retrospective data collection and analysis of paediatric patient data from the electronic records in LDI using a list of appointments attended by cancer patients in LDI. Results: Fifty-one articles were included in the comprehensive literature review following the database search and the inclusion criteria. Numerous studies concluded that chemotherapy and other anticancer treatments in children are linked to increased dental anomalies like microdontia and enamel defects, especially when treatment occurs at a young age. The findings have been summarised in tables. Of the 806 registered appointments identified, the clinical records of 85 childhood cancer survivors who met the inclusion criteria were included. The post-treatment identified conditions included microdontia, hypodontia and enamel hypoplasia. Demographics, cancer diagnosis and type of treatment, in addition to dental findings, were summarised in tables. The data were also categorised according to age at the cancer treatment time and type of treatment provided. Conclusions: The literature review and LDI patient data revealed that childhood cancer survivors commonly face serious long-term dental issues due to their treatments. These findings highlight the importance of a better understanding of cancer therapy's impact on orofacial development, requiring more attention and support from healthcare professionals, particularly dentists

    Asthma Control Impact on the Quality of Life and Parent's Educational Degree Effect on Asthma Control among Pediatric Patients in Saudi Arabia, Riyadh City

    Get PDF
    Asthma is Common, Chronic, and Serious respiratory disease which affect all age groups, especially children, Asthma according to GINA 2016 now days affecting 1-18 % of the population of many different countries around the world. (1) in 2013 a study has been conducted in Saudi Arabia, findings showed that those diagnosed with asthma in KSA do not have good control over their condition; incidence of asthma attacks and referral to hospitals for asthma management were considerably high. (2) The objective of this study is to be able to describe in detail the level of Asthma control among participant and to find the correlation between the control level of the disease and the impact on the pediatric asthmatic patients' quality of life, Also, as a secondary objective we were looking for any correlations with the control of asthma with the parents' education degree. This study was carried out from 5 October 2017 until 3 November 2017, cross-sectional study with a questionnaire which was disturbed. A total 559 child who was diagnosed by asthma were included in the study, For the asthma control test (see figure 1), we found the majority had uncontrolled asthma (45.1%), Most of the children scored 'Never' in Quality of Life Questionnaire when asked in nearly all twelve aspects of the child life. Our results suggest that uncontrolled asthma associated with low quality of life, we did not find any association between asthma control level and Educational degree of the parents. Keywords: Asthma, Asthma control, prevalence of asthma, Saudi arabia, chronic airway diseas

    Stimulatory Effects of Lycium shawii on Human Melanocyte Proliferation, Migration, and Melanogenesis: In Vitro and In Silico Studies

    Get PDF
    There is no first-line treatment for vitiligo, a skin disease characterized by a lack of melanin produced by the melanocytes, resulting in an urgent demand for new therapeutic drugs capable of stimulating melanocyte functions, including melanogenesis. In this study, traditional medicinal plant extracts were tested for cultured human melanocyte proliferation, migration, and melanogenesis using MTT, scratch wound-healing assays, transmission electron microscopy, immunofluorescence staining, and Western blot technology. Of the methanolic extracts, Lycium shawii L. (L. shawii) extract increased melanocyte proliferation at low concentrations and modulated melanocyte migration. At the lowest tested concentration (i.e., 7.8 ÎĽg/mL), the L. shawii methanolic extract promoted melanosome formation, maturation, and enhanced melanin production, which was associated with the upregulation of microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1 and TRP-2 melanogenesis-related proteins, and melanogenesis-related proteins. After the chemical analysis and L. shawii extract-derived metabolite identification, the in silico studies revealed the molecular interactions between Metabolite 5, identified as apigenin (4,5,6-trihydroxyflavone), and the copper active site of tyrosinase, predicting enhanced tyrosinase activity and subsequent melanin formation. In conclusion, L. shawii methanolic extract stimulates melanocyte functions, including melanin production, and its derivative Metabolite 5 enhances tyrosinase activity, suggesting further investigation of the L. shawii extract-derived Metabolite 5 as a potential natural drug for vitiligo treatment

    Stimulatory effects of Lycium shawii on human melanocyte proliferation, migration, and melanogenesis: In vitro and in silico studies

    Get PDF
    There is no first-line treatment for vitiligo, a skin disease characterized by a lack of melanin produced by the melanocytes, resulting in an urgent demand for new therapeutic drugs capable of stimulating melanocyte functions, including melanogenesis. In this study, traditional medicinal plant extracts were tested for cultured human melanocyte proliferation, migration, and melanogenesis using MTT, scratch wound-healing assays, transmission electron microscopy, immunofluorescence staining, and Western blot technology. Of the methanolic extracts, Lycium shawii L. (L. shawii) extract increased melanocyte proliferation at low concentrations and modulated melanocyte migration. At the lowest tested concentration (i.e., 7.8 μg/mL), the L. shawii methanolic extract promoted melanosome formation, maturation, and enhanced melanin production, which was associated with the upregulation of microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1 and TRP-2 melanogenesis-related proteins, and melanogenesis-related proteins. After the chemical analysis and L. shawii extract-derived metabolite identification, the in silico studies revealed the molecular interactions between Metabolite 5, identified as apigenin (4,5,6-trihydroxyflavone), and the copper active site of tyrosinase, predicting enhanced tyrosinase activity and subsequent melanin formation. In conclusion, L. shawii methanolic extract stimulates melanocyte functions, including melanin production, and its derivative Metabolite 5 enhances tyrosinase activity, suggesting further investigation of the L. shawii extract-derived Metabolite 5 as a potential natural drug for vitiligo treatment
    • …
    corecore