New Phosphated Poly(methyl Methacrylate) Polymers for the Prevention of Denture-induced Microbial Infection: an In Vitro Study

Purpose: Poly(methyl methacrylate) (PMMA) has been widely used as a denture-base acrylic resin due to its excellent physical and mechanical properties. However, the material is highly prone to microbial fouling that often leads to Candida-associated denture stomatitis. Incorporation of phosphate groups into PMMA could facilitate adsorption of salivary antimicrobials and inhibit microbial adherence on the polymer surface. An in vitro study evaluated PMMA polymers containing varying amounts of phosphate group for their efficacy to inhibit Candida albicans adhesion, adsorb salivary histatin 5, and exhibit candidacidal activity. Methods: Six PMMA polymers containing 0%, 5%, 15%, 10%, 20%, and 25% of phosphate group were synthesized by bead (suspension) polymerization technique using mixtures of methyl methacrylate and methallyl phosphate as monomers. The efficacy of the polymers to inhibit the adherence of C. albicans was examined by using human saliva-coated polymer beads and radio-labeled C. albicans cells, as compared with that of PMMA. The potency of the phosphated PMMA polymers to adsorb histatin 5 was determined by measuring the radioactivity of the adsorbed labeled-peptide on the polymer surface. The candidacidal activity of the histatin 5-adsorbed polymers was assessed by using the fluorescence technique. The percent release of the fluorescent probe calcein from the C. albicans membrane caused by the disruption of the cell membrane was determined. The data were analyzed statistically by one-way ANOVA followed by Scheffé’s test (α = 0.05 and n = 6). Results: The presence of ≥15% phosphate content in PMMA significantly reduced the saliva-mediated adhesion of C. albicans. Phosphated PMMA polymers showed significantly enhanced adsorption of histatin 5 in a phosphate density-dependent manner. The candidacidal activity of the histatin 5-bound polymers increased significantly with the increase in the phosphate content of the polymer. Conclusion: Phosphated PMMA polymers have the potential to serve as novel denture-base resins, which may reduce C. albicans colonization and prevent denture stomatitis

Development of graphite based nanomaterials for green chemistry applications

Graphite is a valuable natural resource and useful carbon allotrope that has been explored for various applications. Graphene is a two-dimensional (2D) transparent material, which is the strongest, thinnest, and most conductive substance known. Graphene-based materials are strategic nanomaterials that have been investigated for various applications, encompassing water contaminant remediation, energy conversion and storage, and electrochemical biosensors, and graphite is its primary source. This MSc thesis focuses mainly on: (a) the characterization of graphite and the study of its properties, both of which influence the quality of graphene based materials; (b) the development of a novel and simple strategy toward the generation of high quality graphenoids; and (c) the exploration of green chemistry applications such as environmental contaminant remediation and energy conversion and storage. [...

Design and evaluation of a consulting system for database design

Database design is a difficult problem for non-expert designers. It is desirable to assist such designers during the problem solving process by means of a knowledge based (KB) system. Although a number of prototype KB systems have been proposed, there are many shortcomings. Firstly, few have incorporated sufficient expertise in modeling relationships, particularly higher order relationships. Secondly, there does not seem to be any published empirical study that experimentally tested the effectiveness of any of these KB tools. Thirdly, problem solving behavior of non-experts, whom the systems were intended to assist, has not been one of the bases for system design. In this project, a consulting system, called CODA, for conceptual database design that addresses the above short comings was developed and empirically validated. More specifically, the CODA system incorporates (a) findings on why non-experts commit errors and (b) heuristics for modeling relationships. Two approaches to knowledge base implementation were used and compared in this project, namely system restrictiveness and decisional guidance (Silver 1990). The Restrictive system uses a proscriptive approach and limits the designer\u27s choices at various design phases by forcing him/her to follow a specific design path. The Guidance system approach, which is less restrictive, involves providing context specific, informative and suggestive guidance throughout the design process. Both the approaches would prevent erroneous design decisions. The main objectives of the study are to evaluate (1) whether the knowledge-based system is more effective than the system without a knowledge-base and (2) which approach to knowledge implementation - whether Restrictive or Guidance - is more effective. To evaluate the effectiveness of the knowledge base itself, the systems were compared with a system that does not incorporate the expertise (Control). An experimental procedure using student subjects was used to test the effectiveness of the systems. The subjects solved a task without using the system (pre-treatment task) and another task using one of the three systems, viz. Control, Guidance or Restrictive (experimental task). Analysis of experimental task scores of those subjects who performed satisfactorily in the pre-treatment task revealed that the knowledge based approach to database design support lead to more accurate solutions than the control system. Among the two KB approaches, Guidance approach was found to lead to better performance when compared to the Control system. It was found that the subjects perceived the Restrictive system easier to use than the Guidance system

Algorithms to Find Linear Geodetic Numbers and Linear Edge Geodetic Numbers in Graphs

Given two vertices u and v of a connected graph G=(V, E), the closed interval I[u, v] is that set of all vertices lying in some u-v geodesic in G. A subset of V(G) S={v1,v2,v3,….,vk} is a linear geodetic set or sequential geodetic set if each vertex x of G lies on a vi – vi+1 geodesic where 1 ? i < k . A linear geodetic set of minimum cardinality in G is called as linear geodetic number lgn(G) or sequential geodetic number sgn(G). Similarly, an ordered set S={v1,v2,v3,….,vk} is a linear edge geodetic set if for each edge e = xy in G, there exists an index i, 1 ? i < k such that e lies on a vi – vi+1 geodesic in G. The cardinality of the minimum linear edge geodetic set is the linear edge geodetic number of G denoted by legn(G). The purpose of this paper is to introduce algorithms using dynamic programming concept to find minimum linear geodetic set and thereby linear geodetic number and linear edge geodetic set and number in connected graphs

An experimental study on the influence of instructional mobile applications in enhancing listening comprehension of rural students in India

IntroductionMobile learning (M-learning) is integral to language education, offering accessibility, portability, and diverse resources. It offers real-life language use with synchronous learning, flexibility, and an opportunity to engage with the global community. It allows learners to practice language skills from anywhere. This study aims to evaluate linguistic instructional mobile applications' effectiveness on listening comprehension among Indian rural students.MethodsPedagogic mobile applications were employed in an experimental study with 149 tertiary-level students from rural colleges in Tamil Nadu, India. Participants were divided into control (n = 75) and experimental (n = 74) groups. Pre and post-tests assessed listening comprehension levels, considering demographic variables. Different types of audio files were used in the intervention to improve the listening skills of the experimental group.ResultsStatistical analyses, including paired t-tests, independent t-tests, and ANOVA, revealed significant improvement in listening skills for the experimental group. Gender, locality, and parental income were considered as significant variables, showing that students from diverse backgrounds benefited from mobile applications.DiscussionThe results indicate that M-learning effectively aids rural students in overcoming language barriers, emphasizing the potential of mobile applications in language education

LOW-RESOLUTION CUSTOMIZABLE UBIQUITOUS DISPLAYS

In a conventional display, pixels are constrained within the rectangular or circular boundaries of the device. This thesis explores moving pixels from a screen into the surrounding environment to form ubiquitous displays. The surrounding environment can include a human, walls, ceiling, and floor. To achieve this goal, we explore the idea of customizable displays: displays that can be customized in terms of shapes, sizes, resolutions, and locations to fit into the existing infrastructure. These displays require pixels that can easily combine to create different display layouts and provide installation flexibility. To build highly customizable displays, we need to design pixels with a higher level of independence in its operation. This thesis shows different display designs that use pixels with pixel independence ranging from low to high. Firstly, we explore integrating pixels into clothing using battery-powered tethered LEDs to shine information through pockets. Secondly, to enable integrating pixels into the architectural surroundings, we explore using battery-powered untethered pixels that allow building displays of different shapes and sizes on a desired surface. The display can show images and animations on the custom display configuration. Thirdly, we explore the design of a solar-powered independent pixel that can integrate into walls or construction materials to form a display. These pixels overcome the need to recharge them explicitly. Lastly, we explore the design of a mechanical pixel element that can be embedded into construction material to form display panels. The information on these displays is updated manually when a user brushes over the pixels. Our work takes a step forward in designing pixels with higher operation independence to envision a future of displays anywhere and everywhere

HIERARCHICAL APPROACH OF USING P300 IN EEG BASED BCI

Brain Computer Interface is a system that translates the electrical activity of the brain into commands which can control devices in real time applications, enabling the disabled people to communicate with the outside world. In this paper we focus on P300 based real time application where the users’ difficulty in communicating with the external environment is made easier. The P300 Event Related Potential (ERP) are natural responses of the brain to some specific stimuli. A person who is paralysed or bedridden needs full care and attention. This means that a care team will likely be working together (including family, friends, nurses and other professional help). Because of this, it is important to make sure that every or any one of the care team member should always be there with the patient. If there occurs a situation where the patient is in need and the care taker is not present with them, our work finds a solution for this problem using BCI technology. In this concept we use a CRT or LED monitor placed infront of the user where different images are displayed. These images represent the basic needs of the paralysed person. When the user is in need of some requirements they can gaze at the images displayed on the monitor. Meanwhile the signals generated during this event is processed and the output is given to the desired applications. Thus this paper eases the users difficulty in meeting their basic needs

Thanatophoric dysplasia: A case report with probable recurrence

Thanatophoric dysplasia (TD) is a congenital, sporadic, and the most lethal skeletal dysplasia caused by new mutation in the fibroblast growth factor receptor 3 gene. At birth, it is characterized by shortening of the limbs (micromelia), small conical thorax, platyspondyly (flat vertebral bodies), and macrocephaly. TD is divided into two clinically defined subtypes: Type I and II which can be differentiated by the skull shape and femur morphology. Ultrasound examination in the second trimester is often straight forward in diagnosing the congenital anomaly. We report a case of preterm stillborn female baby with dysmorphic facies, macrocephaly, micromelia with short stubby fingers and deep skin creases, short limbs, narrow thorax, and protuberant abdomen delivered at our hospital to a 24-year-old multigravida mother with the previous history of first-trimester abortion. The antenatal ultrasound examination showed shortening of long bones with femur-shaped like a telephone receiver. Dysmorphic facial feature, skeletal abnormalities, and histopathological examination lead us to make the diagnosis of TD Type I. We report this case of TD in view of recurrence risk of around 1%, occurring mostly through autosomal dominant mode of inheritance, which may be the possibility in this case

Field testing of an onsite sanitation system on apartment building blackwater using biological treatment and electrochemical disinfection

The Closed Loop Advanced Sanitation System (CLASS) was designed to treat, disinfect, and recycle toilet blackwater from existing flush toilets in a multi-story apartment building. Two systems were tested at two unique sites in Coimbatore, India for a combined 7500+ treatment hours resulting in more than 180 000 L of treated water. The CLASS prototypes used a combination of biological pretreatment and electrochemical oxidation processes to produce treated water that nearly met the stringent requirements outlined in the standard ISO 30500. The nutrient and organic loading from the toilet blackwater was predominantly reduced by over 85–95% and 80–87%, respectively, through biological processes that were achieved using either a sequencing batch reactor (SBR, site A) or an anaerobic–aerobic biodigester (EcoSan, site B). Complete disinfection of E. coli with nil CFU per ml was achieved using electrochemical processes that also served to remove the remaining organic and nutrient loading to over 90–96%. The treated water was reused for flushing by the residents of the apartment building for 89 days