305 research outputs found
Design and manufacture of functional titanium–palladium devices for the activation of anti-cancer prodrugs
National health organisations and authorities have reported an increment in death cases due to cancer. To overcome this issue and improve the survival rate, it is needed to find new clinical methods, early diagnoses techniques and treatments. Radiation and chemotherapy have been used for years to treat cancer. However, these types of treatments have serious side effects such as hair loosing, the mortality of healthy cells and other organs. A new treatment based on prodrugs therapy is in development with the intention to reduce these side effects or to replace the harmful treatments completely. Prodrug treatments need an activation agent, i.e. a catalyst, to convert the prodrug delivered to the cancerous cells to an active drug in-situ. Metals such as palladium can be used as a catalyst to activate the prodrug in targeted cancer cells. In this PhD study, the research was divided into two major aspects. The first aspect was to design and manufacture a catalyst carrier with specific properties and specifications such as biocompatibility of the materials used as the carrier, suitable mechanical properties to withstand physiological loads and conditions, and cost efficiency of the production. Two different manufacturing methods were used, Powder Metallurgy technique and Arc Melting technique, to achieve the optimal fabrication method. The carriers were characterised via XRD, SEM, EDS, DSC methods and mechanical tests to ensure the carrier meets the requirements. In the second stage, the carriers were coated with Palladium in its metallic state (i.e. Pd0). The coating was required to meet the requirements of being unalloyed, pure and free of any contamination, and its deposition cost and time effective. Four coating methods were employed. Powder Metallurgy technique and sintering (with and without space holder), Magnetron Sputtering, Pulsed Laser Deposition and Supersonic Beam Cluster Deposition methods were used to apply Palladium coating onto the carriers. The coating was characterised by XPS, XRD, FIB, XRF, SEM, EDS, biochemical and in-situ biological tests. The results obtained confirmed that the devices achieve high biocompatibility of the materials, and an excellent superelasticity can withstand the loads inside the human body. Also, the Magnetron sputtering methods as a coating method demonstrated it is the most effective for achieving a uniform and long-lasting deposited layer. The devices were able to activate a clinically approved prodrug.</div
3+1d quasiparticle anisotropic hydrodynamics for ultrarelativistic heavy-ion collisions
We present the first comparisons of experimental data with phenomenological
results from 3+1d quasiparticle anisotropic hydrodynamics (aHydroQP). We
compare charged-hadron multiplicity, identified-particle spectra,
identified-particle average transverse momentum, charged-particle elliptic
flow, and identified-particle elliptic flow produced in LHC 2.76 TeV Pb+Pb
collisions. The dynamical equations used for the hydrodynamic stage utilize
non-conformal aHydroQP. The resulting aHydroQP framework naturally includes
both shear and bulk viscous effects in addition to higher-order non-linear
transport coefficients. The 3+1d aHydroQP evolution obtained is
self-consistently converted to hadrons using anisotropic Cooper-Frye freezeout
performed on a fixed-energy-density hypersurface. The final production and
decays of the primordial hadrons are modeled using a customized version of
THERMINATOR 2. In this first study, we utilized smooth Glauber-type initial
conditions and a single effective freeze-out temperature T_FO = 130 MeV with
all hadronic species in full chemical equilibrium. With this rather simple
setup, we find a very good description of many heavy-ion observables.Comment: 6 pages, 4 figure
Utilising artificial neural networks (ANNs) towards accurate estimation of life-cycle costs for construction projects
This study aimed to establish a new model of Life Cycle Cost (LCC) for construction projects using Artificial Neural Networks (ANNs). Survey research and Costs Significant Items (CSIs) methods were conducted to identify the most important cost and non-cost factors affecting the estimation of LCC. These important factors are considered as input factors of the model. The results indicated that neural network models were able to estimate the cost with an average accuracy between 91%-95%
Revisional Bariatric Surgery
Metabolic surgery is considered a valuable tool in treating obesity compared to the non-surgical approach. Its effectiveness is evident in the form of weight loss, eliminating obesity-related comorbidities, and improving quality of life. Hence, the rate of metabolic surgery conducted worldwide has risen dramatically, parallel to the increasing rates of obesity. Unfortunately, there are drawbacks to metabolic surgeries. Weight regain/insufficient weight loss is feared by the patient and bariatric surgeon and can occur with nonadherence to a healthy lifestyle and dietary habits. Long-term complications related to metabolic surgery are possible following any metabolic surgery (e.g., chronic reflux, malnutrition, and fistula). Revisional surgery is the most effective approach to combat these drawbacks, and therefore a bariatric surgeon should be familiar with it. This chapter will discuss the indication of revisional surgery, the preoperative workup, the surgical techniques, and the outcome of revisional surgery. The chapter will focus on the most commonly performed metabolic surgery, that is, laparoscopic adjustable gastric band, laparoscopic sleeve gastrectomy, laparoscopic Roux-en-Y gastric bypass, and laparoscopic one anastomosis gastric bypass. By the end of this chapter, the reader will be able to: (1) Define metabolic surgery failure and indications of the revision. (2) Be able to approach the patient preoperatively and formulate a plan. (3) Be knowledgeable about the main operative steps. (4) Be aware of the predicted outcome of revisional surgery
Quranic Arabic Semantic Search Model Based on Ontology of Concepts
The Holy Quran is the essential resource for Islamic sciences and Arabic language. Therefore, numerous Quranic search applications have been built to facilitate the retrieval of knowledge from the Quran. This thesis presents a novel Arabic Quran semantic search model.
First, this thesis evaluated existing search tools constructed for the Holy Quran, against 13 criteria depending on: search features, output features, the precision of the retrieved verses, recall database size, and types of database contents.
Then, the study reviewed the existing Quran ontologies and compared them against 11 criteria. Some deficits have been found in all these ontologies. Additionally, a single Quranic ontology does not cover most of the knowledge in the Quran. Therefore, I developed a new Arabic-English Quran ontology from ten datasets related to the Quran such as: Quran chapter and verse names, Quran word meanings, and Quran topics. The main aim of developing a Quranic ontology is to facilitate the retrieval of knowledge from the Quran. Additionally, the Quran ontology will enrich the raw Arabic and English Quran text with Islamic semantic tags.
Furthermore, I developed the first Annotated Corpus of Quran Questions and Answers in Arabic. This corpus has 2200 pairs of question and answer collected from trusted Islamic sources. Each pair of question and answer is labelled with 5 tags. Examples of tags are: question type: either factoid or descriptive, topic of question-based on the Quran ontology, and question class.
Finally, the thesis explains a new semantic search model for the Arabic Quran based on my Quran ontology. This model aims at overcoming limitations in the existing Quran search applications. This search tool employs both Information Retrieval techniques and semantic search technologies. The performance of this search model is evaluated by using The Annotated Corpus of Arabic Quran Questions and Answers
Comparative early outcomes of tricuspid Valve repair versus replacement for secondary tricuspid regurgitation
Background Comparative outcome data on tricuspid valve repair (TVr) versus tricuspid valve replacement (TVR) for severe secondary tricuspid regurgitation (TR) are limited.
Methods We used a national inpatient sample to assess in-hospital morbidity and mortality, length of stay and cost in patients with severe secondary TR undergoing isolated TVr versus TVR.
Results A total of 1364 patients (national estimate=6757) underwent isolated tricuspid valve surgery during the study period, of whom 569 (41.7%) had TVr and 795 (58.3%) had TVR. There was no difference in the prevalence of major morbidities between the two groups, except for liver disease and hepatic cirrhosis, which
were more common in the TVR group. Before propensity matching, in-hospital mortality was similar between patients who underwent isolated TVr and TVR (8.1% vs 10.8%, p=0.093), but the incidence of postoperative morbidities differed: TVR was associated with higher rates of permanent pacemaker implantation and blood transfusion, while TVr was associated with more acute kidney injury. After rigorous propensity score matching, TVR was associated with significantly higher rates of in- hospital death (12% vs 6.9%, p=0.009) and permanent pacemaker implantation (33.7% vs 11.2%, p\u3c0.001). Postoperative morbidities and length of stay, however, were not different between the two groups. Nonetheless, cost of hospitalisation was 16% higher in the TVr group. Conclusions In patients undergoing isolated surgery for secondary TR, TVR is associated with higher in-hospital mortality and need for permanent pacemaker compared with TVr. Further studies are needed to understand the impact of the type of surgery on the short-term and long- term mortality in this complex undertreated populatio
Knowledge and Interest in Treating Gingival Recession among Dental Practitioners in Saudi Arabia
BACKGROUND: Gingival recession is an enigma among clinicians due to multiple etiological factors and various treatment modalities.
AIM: Objective of this study was to evaluate the knowledge and interest among dental practitioners regarding the treatment of gingival recession.
MATERIAL AND METHODS: A survey was conducted to assess knowledge of gingival recession and interest and satisfaction of dental practitioners in periodontics. This survey was circulated among 250 dental practitioners throughout four months. The structured questionnaire consisted of 9 questions assessing the knowledge and interest of dental practitioners in periodontics; gingival recession per se.
RESULTS: Majority of the participants were general dentists. Among them, 46.23% had a habit of reading dental journals. Most of the participants had an opinion that improper tooth brushing (42.71%) is an important cause of the gingival recession. Only 34.17% had information about Miller's classification of gingival recession. Regarding general indication of root coverage procedures, 28.64% answered aesthetics was the most common indication. 39.7% mentioned that traumatic occlusion was a risk factor for gingival recession. A group of 29.65% mentioned that accidental toothbrush trauma leads to gingival recession.
CONCLUSION: The knowledge of gingival recession among the study participants was adequate. More specifically, the interest of participants in periodontics was 5.39 and satisfaction in treating periodontal cases was 5.47
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