Reliability of finite element method for time harmonic electromagnetic problems involving moving bodies

This work is mainly concerned about the time-harmonic electromagnetic problems involving moving bodies. Such a formulation is possible when the boundaries between different moving objects are stationary and the sources involved are time-harmonic. Even simple media present bianisotropic properties when they are in motion. This kind of problems find applications in diverse fields. Numerical solution is required for most of the practical problems. We examined the reliability of finite element simulator developed for solving such problems

Processing of fluoro alumino-silicate glass-ceramics by Field Assisted Sintering Technology and honeycomb extrusion technique

Field Assisted Sintering Technique (FAST) was used for the crystallisation of ionomer glasses and the production of the relevant glass ceramics. Extrusion was also used as an alternative processing method to produce honeycomb glass ceramics derived from similar glass compositions. Apatite-mullite glass ceramics derived from the general glass composition 4.5SiO$_2$-3A1$_2$O$_3$- 1.5P$_2$O$_5$-(5-x)CaO-xCaF$_2$ can be produced by a lost wax method. However, Field Assisted Sintering Technique and Honeycomb Extrusion Technique are never used before and this present work presents the first data on the use of both of the above mentioned techniques. Calcium (Ca), Strontium (Sr) and Magnisium (Mg) containing glass powder compositions were produced and processed by FAST and Extrusion technique. X-ray diffraction of the materials produced by FAST showed the formation of a fluorapatite, mulite and a minor A1PO$_4$ phase for the calcium glass. Sr-fluorapatite and Sr-aluminium silicate were formed in Sr glass and mullite and wagnerite were formed in Mg glasses. All the crystal phases formed were in good agreement with previous conventional crystallization studies. The FAST sintered glass ceramic properties were improved when compared with conventional sintering. In extrusion technique, the rheological properties were studied using Benow/Bridgwater model for paste parameters. Honeycomb extrusion pressure drop was also studied using a model developed by Blackburn and Bohm. In this study, we used waste glass to model the binder rehology of glass powder and modelled binder rheology in the apatite mullite glass. The measured paste parameters were in good agreement when compared with the experimental results. The produced honeycomb structure was sintered conventionally using a furnace. Microstructural studies and X-ray diffraction were carried out. The results of this studies show a well-defined porous structure and formation of crystal phases similar to the phases observed during conventional sintering

405 nm light exposure of osteoblasts and inactivation of bacterial isolates from arthroplasty patients : potential for new disinfection applications?

Infection rates after arthroplasty surgery are between 1-4 %, rising significantly after revision procedures. To reduce the associated costs of treating these infections, and the patients' post-operative discomfort and trauma, a new preventative method is required. High intensity narrow spectrum (HINS) 405 nm light has bactericidal effects on a wide range of medically important bacteria, and it reduced bacterial bioburden when used as an environmental disinfection method in a Medical Burns Unit. To prove its safety for use for environmental disinfection in orthopaedic theatres during surgery, cultured osteoblasts were exposed to HINS-light of intensities up to 15 mW/cm2 for 1 h (54 J/cm2). Intensities of up to 5 mW/cm2 for 1 h had no effect on cell morphology, activity of alkaline phosphatase, synthesis of collagen or osteocalcin expression, demonstrating that under these conditions this dose is the maximum safe exposure for osteoblasts; after exposure to 15 mW/cm2 all parameters of osteoblast function were significantly decreased. Viability (measured by protein content and Crystal Violet staining) of the osteoblasts was not influenced by exposure to 5 mW/cm2 for at least 2 h. At 5 mW/cm2 HINS-light is an effective bactericide. It killed 98.1 % of Staphylococcus aureus and 83.2 % Staphylococcus epidermis populations seeded on agar surfaces, and is active against both laboratory strains and clinical isolates from infected hip and knee arthroplasties. HINS-light could have potential for development as a method of disinfection to reduce transmission of bacteria during arthroplasty, with wider applications in diverse surgical procedures involving implantation of a medical device. With kind permission of full reproduction from eCM journal (www.ecmjournal.org). Founded by scientists for the benefit of Science rather than profit

Analyze and Compare the Crystallographic Changes for Zinc Substituted Hydroxyapatite using X-Ray Diffraction

The main motive of the study is to analyze and compare the crystallographic changes using the X-Ray diffraction method for zinc substituted hydroxyapatite. Materials and Methods: Different types of zinc substituted hydroxyapatite are used. Calcium nitrate tetrahydrate, zinc chloride hexahydrate, diammonium hydrogen phosphate and ammonium hydroxide solutions are added and they are mixed with ammonium hydroxide solution. The ultrasonic was used to carry the precipitation method. The zinc substituted data(N=4), the total sample size was calculated as 4 using clinclac.com, alpha error is 0.05, the G power at 80%, the enrollment ratio to 0:1 and the confidence interval to 95% and the total sample size was computed. Result: Using SPSS software and a one sample T-test, 0% 1%, 5% and 10% percent of zinc with hydroxyapatite were calculated. There is a statistical significance, P=0.002, (p<0.05). The wt% of Zinc hydroxyapatite is of no significance with P=0.177, (p<0.05). The result shows that when compared to other percentages, 10% of zinc substituted hydroxyapatite. Conclusion: The analysis of this study shows that Hydroxyapatite with 10% Zinc Doped Hydroxyapatite has Superior qualities to other Substitutes for future medical applications

Needleless Electrospun Nanofibers for Drug Delivery Systems

Bubble, hollow tube, roller, wire-based and slit-surface needleless electrospinning units are discussed on the basis of the entrepreneurial product cycle of prototype development translating into commercial units. The controlled release of curcumin from a scaffold under physiological simulated conditions shows a significant release of curcumin within 48 hours of test. This work may serve as a useful guide for a drug delivery industry to process nanofibers at a large and continuous scale with a blend of drugs in the nanofibers using wire electrode electrospinning. This work may also serve as a useful guide to obtain a high-quality nanofiber from a needleless electrospinning process for drug delivery applications

Cytotoxic responses to 405 nm light exposure in mammalian and bacterial cells : involvement of reactive oxygen species

Light at wavelength 405 nm is an effective bactericide. Previous studies showed that exposing mammalian cells to 405 nm light at 36 J/cm2 (a bactericidal dose) had no significant effect on normal cell function, although at higher doses (54 J/cm2), mammalian cell death became evident. This research demonstrates that mammalian and bacterial cell toxicity induced by 405 nm light exposure is accompanied by reactive oxygen species production, as detected by generation of fluorescence from 6-carboxy-2’,7’- dichlorodihydrofluorescein diacetate. As indicators of the resulting oxidative stress in mammalian cells, a decrease in intracellular reduced glutathione content and a corresponding increase in the efflux of oxidised glutathione was observed from 405 nm light treated cells. The mammalian cells were significantly protected from dying at 54 J/cm2 in the presence of catalase, which detoxifies H2O2. Bacterial cells were significantly protected by sodium pyruvate (H2O2 scavenger) and by a combination of free radical scavengers (sodium pyruvate, dimethyl thiourea (OH scavenger) and catalase) at 162 and 324 J/cm2. Results herefore suggested that the cytotoxic mechanism of 405 nm light in mammalian cells and bacteria could be oxidative stress involving predominantly H2O2 generation, with other ROS contributing to the damage

Functionalization of textile cotton fabric with reduced graphene oxide/MnO2/polyaniline based electrode for supercapacitor

In this work, a new cotton electrode has been synthesized by coating ternary materials of reduced graphene oxide (rGO), manganese dioxide (MnO2), and polyaniline (PANi) on textile cotton fabric. First, Graphene oxide was deposited on cotton fibers by a simple 'dip and dry' method and chemically reduced into rGO/cotton fabric. MnO2 nanoparticles were accumulated on rGO/cotton fabric by in situ chemical deposition method. PANi layer was coated on rGO/MnO2/cotton fabric by in situ oxidative polymerization technique. A thin PANi coating layer acts as a protective layer on rGO/MnO2/cotton fabric to restrain MnO2 nanoparticles and rGO from dissolution in H2SO4 acidic electrolyte. The specific surface area of cotton electrode was measured using the Brenauer-Emmett-Teller (BET) method. The cyclic voltammetry (CV) results show that the cotton electrode has good capacitive behavior. The ternary cotton electrode exhibits high specific capacitance values of 888 F g(-1) and 252 F g(-1) at a discharge current density of 1 A g(-1) and 25 A g(-1) in 1MH(2)SO(4) electrolyte solution. The high areal specific capacitance of 444 Fcm(-2) was achieved for as-fabricated electrode. Also, the cotton electrode retains around 70% of specific capacitance after 3000 cycles at charge-discharge current density of 15 A g(-1). The slow decrease in specific capacitance is observed with increased discharge current density which proves its excellent rate capability. These results of rGO/MnO2/PANi/cotton fabric electrode show that this can be an excellent electrode for supercapacitor in energy storage devices

The effects of 405 nm light on bacterial membrane integrity determined by salt and bile tolerance assays, leakage of UV absorbing material and SYTOX green labelling

Bacterial inactivation by 405nm light is accredited to the photo-excitation of intracellular porphyrin molecules which results in energy transfer and the generation of reactive oxygen species (ROS) which impart cellular oxidative damage. The specific mechanism of cellular damage, however, is not fully understood. Previous work has suggested that destruction of nucleic acids may be responsible for inactivation; however, microscopic imaging has suggested membrane damage as a major constituent of cellular inactivation. This study investigates the membrane integrity of Escherichia coli and Staphylococcus aureus exposed to 405nm light. Results indicated membrane damage to both species, with loss of salt and bile tolerance by S. aureus and E. coli, respectively, consistent with reduced membrane integrity. Increased nucleic acid release was also demonstrated in 405nm light-exposed cells, with up to 50% increase in DNA concentration into the extracellular media in the case of both organisms. SYTOX green fluorometric analysis however demonstrated contradictory results between the two test species. With E. coli, increasing permeation of SYTOX green was observed following increased exposure, with >500% increase in fluorescence, whereas no increase was observed with S. aureus. Overall, this study has provided good evidence that 405nm light exposure causes loss of bacterial membrane integrity in E. coli, but the results with S. aureus are more difficult to explain. Further work is required to gain greater understanding of the inactivation mechanism in different bacterial species, as there are likely to be other targets within the cell which are also impaired by the oxidative damage from photo-generated ROS

The future of cervical cancer prevention: advances in research and technology

This article provides an informative overview of the current situation and future trends in cervical cancer prevention. Cervical cancer remains a significant public health concern worldwide and is characterized by notable variations in both incidence and mortality rates between developed and developing countries. This underscores the importance of understanding the pathophysiology of cervical cancer, stressing the involvement of high-risk HPV types. The presence of supplementary risk factors facilitates the transition from infection to cancer. This review examines current preventive methods, including the success of HPV vaccines such as Gardasil and Cervarix, and the effectiveness of screening techniques, from cytology to HPV DNA testing. It noted the limitations faced by primary and secondary preventive measures, particularly in low-resource settings, which include access to vaccines and effective screening procedures. Emerging technologies in cervical cancer prevention, such as liquid-based cytology, molecular testing, and AI, promise to improve early detection and diagnosis accuracy and efficiency. The potential of precision medicine to customize treatment based on individual risk factors was discussed. It explores the innovation in genetic editing techniques, such as CRISPR/Cas9, in targeting HPV oncoproteins, the advent of immunotherapy, the role of tumor-infiltrating lymphocytes, and the prospects of biomarkers in improving early detection. Research and technological advancements are leading to transformative changes in cervical cancer prevention. These developments suggest a path toward improved screening, diagnosis, and treatment that could significantly reduce the global burden of the disease. However, realizing the full potential of these advances requires inclusive research and international collaboration to overcome access disparities, particularly in resource-limited settings