Occlusal Splint Therapy for a Dysfunctional Temporomandibular Joint

Splint therapy is an effective form of treatment for the pain of many types of temporomandibular disorders and bruxism. There are many unanswered questions as to how splints work. This article is a review of the literature which focuses on an effective splint design for the different degrees of temporomandibular problems

Predicting the potential geographical distribution of the sugarcane woolly aphid using GARP and DIVA-GIS

Management of newly emerging pests and diseases has often been limited by the lack of forecasting systems that could predict the route(s) of spread and potential geographical distribution of the species. While the importance of the patterns of spread of invasive organisms has always been realized, the necessary analytical tools for making reasonably robust predictions are limited. In recent years however, availability of ecological and climatologic data,computational abilities to process huge data sets, and development of suitable algorithms have helped in a better understanding of the patterns of spread of the invasive species. For instance, algorithms such as Genetic Algorithm for Rule Set Prediction (GARP) and DIVA-GIS, are being successfully employed in a wide range of situations for predicting the spread of invasive species1–4. Here, we explore these two modelling approaches to predict the potential geographical distribution of a newly emerging insect pest, the sugarcane woolly aphid that has played havoc with crops in parts of Maharashtra and Karnataka5

Evaluation of the antimicrobial activity of heat-cure denture base resin materials incorporated with silver nanoparticles

Background: Poly (Methyl methacrylic acid) based materials are the most widely used for the fabrication of removable complete and partial dentures. Certain microorganisms adhere to the tissue surface of a denture base, especially on palatal region, often leading to Denture stomatitis. Numerous attempts were made to treat the denture stomatitis with various antifungal agents showing variable success rates. This may be attributed to the loss of the drug rapidly into the saliva, inhomogeneous distribution of the drug and the development of resistance to antifungal therapy. Aim: This study was done to evaluate the effect of incorporating various concentrations of silver nanoparticles on the antimicrobial activity of heat-cure denture base resin materials. Methods: Silver nanoparticles were incorporated at various concentrations (0.5, 1.0, 2.0 and 5.0 wt%) into three heat-cure denture base materials. A total of 300 disc-shaped specimens (10 × 2 mm) of heat-cure acrylic resin were made using compression molding technique which comprises 100 specimens with each denture base material. Fifty specimens from each denture base materials were allocated to each microorganism used in the study which comprises into five groups with ten specimens (n=10) for each concentration such as control, 0.5wt%, 1.0wt%, 2.0wt% and 5.0wt% concentrations of silver nanoparticles. Antimicrobial activity of control and modified specimens were evaluated using direct contact method against C albicans, and S Mutans by counting the number of colony-forming units. The data were subjected to One way ANOVA and Tukey HSD tests for statistical analyses. Results: Significant(P<0.05) differences were observed in the antimicrobial activity against C albicans and S Mutans between the control and modified groups of heat-cure denture base resin materials. Conclusion: Silver nanoparticles are the favourable materials to incorporate into denture base materials as they exhibit superior antimicrobial activity

Global, regional, and national incidence of six major immune-mediated inflammatory diseases: findings from the global burden of disease study 2019

Background The causes for immune-mediated inflammatory diseases (IMIDs) are diverse and the incidence trends of IMIDs from specific causes are rarely studied. The study aims to investigate the pattern and trend of IMIDs from 1990 to 2019. Methods We collected detailed information on six major causes of IMIDs, including asthma, inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, psoriasis, and atopic dermatitis, between 1990 and 2019, derived from the Global Burden of Disease study in 2019. The average annual percent change (AAPC) in number of incidents and age standardized incidence rate (ASR) on IMIDs, by sex, age, region, and causes, were calculated to quantify the temporal trends. Findings In 2019, rheumatoid arthritis, atopic dermatitis, asthma, multiple sclerosis, psoriasis, inflammatory bowel disease accounted 1.59%, 36.17%, 54.71%, 0.09%, 6.84%, 0.60% of overall new IMIDs cases, respectively. The ASR of IMIDs showed substantial regional and global variation with the highest in High SDI region, High-income North America, and United States of America. Throughout human lifespan, the age distribution of incident cases from six IMIDs was quite different. Globally, incident cases of IMIDs increased with an AAPC of 0.68 and the ASR decreased with an AAPC of −0.34 from 1990 to 2019. The incident cases increased across six IMIDs, the ASR of rheumatoid arthritis increased (0.21, 95% CI 0.18, 0.25), while the ASR of asthma (AAPC = −0.41), inflammatory bowel disease (AAPC = −0.72), multiple sclerosis (AAPC = −0.26), psoriasis (AAPC = −0.77), and atopic dermatitis (AAPC = −0.15) decreased. The ASR of overall and six individual IMID increased with SDI at regional and global level. Countries with higher ASR in 1990 experienced a more rapid decrease in ASR. Interpretation The incidence patterns of IMIDs varied considerably across the world. Innovative prevention and integrative management strategy are urgently needed to mitigate the increasing ASR of rheumatoid arthritis and upsurging new cases of other five IMIDs, respectively. Funding The Global Burden of Disease Study is funded by the Bill and Melinda Gates Foundation. The project funded by Scientific Research Fund of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital (2022QN38)

Performance evaluation of two fuzzy-logic-based homing guidance schemes

Homing guidance schemes based on fuzzy logic have been developed for a planar engagement model, with randomly jinking target maneuver and line-of-sight (LOS) rate measurement corrupted with glint noise. Two versions of fuzzy guidance schemes have been proposed, the first one using information required for proportional navigation (PN) and the second one using the information required for augmented PN (APN). The performance of the two fuzzy guidance schemes, in terms of commanded acceleration profiles and the values of the terminal miss distance, have been compared with PN and APN, respectively. It is observed that the fuzzy guidance schemes are able to match closely the performance of PN and APN guidance laws, and in cases where the measurements are noisy and the estimates are inaccurate, the fuzzy guidance schemes are shown to perform better than PN and APN

Sliding mode estimation scheme for missile homing guidance

A new approach to maneuvering target tracking using the Sliding Mode Observer theory, in the specific context of homing missile guidance, is developed. This scheme requires a priori information about the target acceleration bounds alone, and there is no need for a dynamic model to represent the target maneuver dynamics. The proposed estimator is as simple to implement as the conventional Extended Kalman Filter (EKF) itself. The simulation results, in the presence of realistic noise sources, demonstrate the superiority of the proposed estimation scheme over the EKF

Two robust homing missile guidance laws based on sliding mode control theory

Two new guidance laws for short range homing missiles are developed by invoking the sliding mode control (SMC) theory. Guidance law 1 as structured around the basic proportional navigation (PN), with an additive switching term, which is a function of the line of sight (LOS) rate alone. An adaptive procedure is suggested to select the gain of the switching term, in order to reduce chattering. This guidance law is nearly as simple to implement as the PN itself and does not require any explicit target maneuver estimation. Guidance law 2, based on a first order sliding surface, is designed such that it results in a continuous acceleration law, thereby reducing the chattering problem. While explicitly taking into account the effect of aerodynamic drag, it requires the second derivatives of LOS angle and range, which are not directly measured. An estimation scheme, again based on sliding mode theory, is presented to estimate these quantities. Simulation results clearly demonstrate the superior performance of these scheme

Switched Bias Proportional Navigation for Homing Guidance Against Highly Maneuvering Targets

A new form of the Proportional Navigation (PN) guidance law for short-range homing missiles is proposed. Named the Switched Bias Proportional Navigation (SBPN) law, it is derived by invoking sliding-mode control theory and is structured around the basic PN, with an additive switched bias term. This additional term depends only on the polarity of the line-of-sight rate, which is readily available with a seeker. It is shown that the bias term acts as an estimate of the target acceleration and other unmodeled dynamics. An adaptive procedure is suggested to select the gain of this term, which results in improved performance. The SBPN is almost as simple to implement as the PN law itself, as it does not require any additional information related to the engagement, in the form of either measurements or estimates. Simulation results show that the acceleration profiles of SBPN closely follow those of augmented PN guidance law, after a short initial transient. They further demonstrate the robustness of the proposed SBPN in the presence of missile velocity variation

Guided missile with an intelligent agent

Guided missiles involve the use of a conventional deviated pursuit course like proportional navigation algorithm and its variants, which is optimal when the speed advantage of the guided missile is very high and the target maneouvering is minimal. Against the present-day aircraft, which employs fly-by-wire technology for high maneouverability and high speed, missiles need to have a much higher speed advantage or to use a combination of artificial intelligence and modern control algorithms. Results of Simulation of pursuit and evasion with an autonomous intelligent agent incorporated in the control loop are presented