406 research outputs found
Two secure non-symmetric role Key-Agreement protocols
Recently, some two-party Authenticated Key Agreement protocols over elliptic curve based algebraic groups, in the context of Identity-Based cryptography have been proposed. The main contribution of this category of protocols is to reduce the complexity of performing algebraic operations through eliminating the need to using Bilinear Pairings. In this paper, we proposed two novel Identity-Based Authenticated Key Agreement protocols over non-symmetric role participants without using Bilinear Pairings. The results show that our proposed schemes beside of supporting security requirements of Key Agreement protocols, require a subset of operations with low complexity in compare with related protocols in this scientific area
STRESS AND ITS RELIEF AMONG UNDERGRADUATE DENTAL STUDENTS IN MALAYSIA
This study was conducted to identify the prevalence of stress, types of stressors, consequences of stress and stress relievers among undergraduate dental students at the University of Malaya during the different years of study. A descriptive cross-sectional quantitative study was conducted using a self-administered questionnaire among Bachelor of Dental Surgery students during Years 2 to 5. A 100 response rate was obtained. The instrument asked questions about the preceding academic year. The results of the questionnaire reveal the prevalence of stress was 100. The most common cause of stress among preclinical students was academic concerns and among clinical students was patient management and clinical performance. Physical and behavioral problems were reported as consequences of stress. Most students overcame stress by having strong interpersonal relationships. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down
Synthesis and characterization of photocrosslinked biobased polyester membrane
A series of bio-based photocrosslinked polyester membranes, poly(1,8-octanediol-itaconate-citrate-dodecandioate), (POSCI) were synthesized through polycondensation followed by photocrosslinking under UV irradiation in the presence of 2,2-dimethoxy-2-phenylacetophenone (DMPA) as photoinitiator (PI). Upon varied UV exposure time and DMPA content, the corresponding changes in chemical, structural, and mechanical properties of the polymer were studied. The transmission peak of FTIR spectrum centred at 1725 cm-1 indicates the formation of ester structure. Contact angle results suggested all of the synthesized POSCI membranes had hydrophilic properties as their contact angle is less than 90 °. Sol-gel analysis shows that the swelling ratio of POSCI decreases while the gel fraction increases with increasing in photocrosslinking time. The tensile strength of POSCI, thus, increased correspondingly with longer UV exposure. Excess DMPA, however, proved otherwise
Design And Development Of High Frequency High Power Transformer For Renewable Energy Application.
This paper presents a design and fabrication of a high
frequency transformer for 5 kW power rating. Within an
operating frequency of 25 kHz, a MnZn P type core has
been utilized. Two set of E-E geometry cores had to be
stacked in order to achieve rhe calculated 64.14 cm4 of
the W^Ac volume. Test and validation of the designed
shows that the prototype designed tansformer had
proven to be very compact, higher fill factor, smaller in
size, lighter in weight if compared to other winding
approaches which utilizing copper round wires. The
measured overall losses of the transformer itself were
remain below the expected value of 32.974 W. The
efficiency of the transformer was found to be at 93%
average. Overall test results also show that the design
and implementation of this high frequency power
transformer is applicable especially fo renewable energy
system.
Synthesis and Characterization of Silver-Coated Polymeric Scaffolds for Bone Tissue Engineering: Antibacterial and In Vitro Evaluation of Cytotoxicity and Biocompatibility
In bone tissue engineering, multifunctional composite materials are very challenging. Bone tissue engineering is an innovative technique to develop biocompatible scaffolds with suitable orthopedic applications with enhanced antibacterial and mechanical properties. This research introduces a polymeric nanocomposite scaffold based on arabinoxylan-co-acrylic acid, nano-hydroxyapatite (nHAp), nano-aluminum oxide (nAl₂O₃), and graphene oxide (GO) by free-radical polymerization for the development of porous scaffolds using the freeze-drying technique. These polymeric nanocomposite scaffolds were coated with silver (Ag) nanoparticles to improve antibacterial activities. Together, nHAp, nAl₂O₃, and GO enhance the multifunctional properties of materials, which regulate their physicochemical and biomechanical properties. Results revealed that the Ag-coated polymeric nanocomposite scaffolds had excellent antibacterial properties and better microstructural properties. Regulated morphological properties and maximal antibacterial inhibition zones were found in the porous scaffolds with the increasing amount of GO. Moreover, the nanosystem and the polymeric matrix have improved the compressive strength (18.89 MPa) and Young’s modulus (198.61 MPa) of scaffolds upon increasing the amount of GO. The biological activities of the scaffolds were investigated against the mouse preosteoblast cell lines (MC3T3-E1) and increasing the quantities of GO helps cell adherence and proliferation. Therefore, our findings showed that these silver-coated polymeric nanocomposite scaffolds have the potential for engineering bone tissue
Automated attendance management and alert system
“Automated Attendance Management and Alert System (AAMAS)” was developed to help UiTM lecturers and Academic Affairs Department in monitoring students’ absenteeism and improving the absenteeism record management. AAMAS provides various functions, from managing and recording students’ attendance record, to sending automatic alerts to students with high absenteeism via short messaging system (SMS) and email. The system is also able to track the number of alerts sent. Through AAMAS, a significant amount of time and money can be saved, for instance time needed to fill out forms and issue notification letters manually can be minimized significantly. Besides, message interception, human resources and human errors can also be reduced. AAMAS which was tailored to UiTM could be also enhanced and custom-made to cater other learning institutions’ requirements throughout Malaysia.Keywords: automated system; attendance management; system development
A comprehensive review on the applications of exosomes and liposomes in regenerative medicine and tissue engineering
Tissue engineering and regenerative medicine are generally concerned with reconstruct-ing cells, tissues, or organs to restore typical biological characteristics. Liposomes are round vesicles with a hydrophilic center and bilayers of amphiphiles which are the most influential family of na-nomedicine. Liposomes have extensive research, engineering, and medicine uses, particularly in a drug delivery system, genes, and vaccines for treatments. Exosomes are extracellular vesicles (EVs) that carry various biomolecular cargos such as miRNA, mRNA, DNA, and proteins. As exosomal cargo changes with adjustments in parent cells and position, research of exosomal cargo constitu-ents provides a rare chance for sicknesses prognosis and care. Exosomes have a more substantial degree of bioactivity and immunogenicity than liposomes as they are distinctly chiefly formed by cells, which improves their steadiness in the bloodstream, and enhances their absorption potential and medicinal effectiveness in vitro and in vivo. In this review, the crucial challenges of exosome and liposome science and their functions in disease improvement and therapeutic applications in tissue engineering and regenerative medicine strategies are prominently highlighted
Quality of life satisfaction among converted Kelantan Chinese Muslims
This article investigates the quality of life of the Kelantan Chinese Muslim community before and after conversion to Islam, focusing on their level of satisfaction in term of economic aspect. This research was carried out using the sequential explanatory mixed method design involving 75 respondents selected for quantitative and five respondents for qualitative. The sampling method adopted was convenience and snowball samplings. The research data was collected using questionnaires and semi-structured interviews. The results revealed that respondents were moderately satisfied before conversion and satisfied after conversion. Besides that, there is no significant difference of quality of life before and after conversion to Islam (F = 0.868, p = 0.355) and it was not influenced by the period of conversion to Islam (F = 0.832, p = 0.589). This analysis indicates numerous respondents are still moderately satisfied in their quality of life even though the average data shows they are satisfied after conversion
Non-viral, Tumor-free Induction of Transient Cell Reprogramming in Mouse Skeletal Muscle to Enhance Tissue Regeneration
© 2018 The American Society of Gene and Cell Therapy. Overexpression of Oct3/4, Klf4, Sox2, and c-Myc (OKSM) transcription factors can de-differentiate adult cells in vivo. While sustained OKSM expression triggers tumorigenesis through uncontrolled proliferation of toti- and pluripotent cells, transient reprogramming induces pluripotency-like features and proliferation only temporarily, without teratomas. We sought to transiently reprogram cells within mouse skeletal muscle with a localized injection of plasmid DNA encoding OKSM (pOKSM), and we hypothesized that the generation of proliferative intermediates would enhance tissue regeneration after injury. Intramuscular pOKSM administration rapidly upregulated pluripotency (Nanog, Ecat1, and Rex1) and early myogenesis genes (Pax3) in the healthy gastrocnemius of various strains. Mononucleated cells expressing such markers appeared in clusters among myofibers, proliferated only transiently, and did not lead to dysplasia or tumorigenesis for at least 120 days. Nanog was also upregulated in the gastrocnemius when pOKSM was administered 7 days after surgically sectioning its medial head. Enhanced tissue regeneration after reprogramming was manifested by the accelerated appearance of centronucleated myofibers and reduced fibrosis. These results suggest that transient in vivo reprogramming could develop into a novel strategy toward the acceleration of tissue regeneration after injury, based on the induction of transiently proliferative, pluripotent-like cells in situ. Further research to achieve clinically meaningful functional regeneration is warranted
In Vivo evaluation of the novel nanocomposite porous 3D scaffold in a rabbit model: hematology and biochemistry analysis
Issues of safety are very crucial with biomaterials and medical devices. Sixteen male New Zealand White rabbits equally into four groups: Group A, rabbits had part of their radial bone (2 cm, mid shaft) and left empty as a control. Group B, rabbits were implanted with scaffold 5211. Group C, rabbits were implanted with scaffold 5211GTA+Alginate. Group D, rabbits were implanted with 5211PLA. All scaffolds were prepared by freeze-drying method. Blood samples were collected at day 0 and 1st, 2nd, 3rd, 4th and 8th week after implantation. The blood examination included complete hemogram and certain serum biochemical parameters. The results showed that there was no significant difference (P>0.05) among each treatment group in comparison with control group (day 0). However, red blood cells, hemoglobin, packed cell volume, mean corpuscular hemoglobin concentration, monocyte, plasma protein, inorganic phosphate, sodium, chloride and urea were significantly increased (P<0.05) among treatment groups at week 8. An abnormal architecture of viscera was observed in all animals, thus indicating a form of toxicity related to the degrading scaffold materials. The severity of histopathological lesions in viscera was not coated polymers dependent nor development materials. In conclusion, implantation of 5211 scaffold with or without coated framework has a significant impact on histopathological and certain hematological and biochemical parameters
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