Statistical analysis in cellular systems for channel capacity improvement with dynamic pilots across different angles users.

Accurate channel state information (CSI) is crucial for optimizing wireless communication systems. In scenarios with varying user-to-base station angles, the angle-dependent coherence time impacts conventional pilot strategies. Due to small angles, the coherence time of the user decreases dramatically because of doppler shift, which causes an increase in the number of pilots. We introduces an innovative sub-block design approach for systems with different user angles. This method harmonizes coherence time of high and low-angle users, while maintaining a constant pilot count. This not only improves spectral efficiency but also ensures accurate channel estimation. Through simulations, we demonstrate the effectiveness of our approach in enhancing both spectral efficiency upt to 10 % and CSI precision. This breakthrough contributes to the advancement of channel estimation techniques in scenarios with angle-dependent coherence time, offering practical benefits to wireless communication systems.

A novel simulation-based analysis of a stochastic HIV model with the time delay using high order spectral collocation technique.

The economic impact of Human Immunodeficiency Virus (HIV) goes beyond individual levels and it has a significant influence on communities and nations worldwide. Studying the transmission patterns in HIV dynamics is crucial for understanding the tracking behavior and informing policymakers about the possible control of this viral infection. Various approaches have been adopted to explore how the virus interacts with the immune system. Models involving differential equations with delays have become prevalent across various scientific and technical domains over the past few decades. In this study, we present a novel mathematical model comprising a system of delay differential equations to describe the dynamics of intramural HIV infection. The model characterizes three distinct cell sub-populations and the HIV virus. By incorporating time delay between the viral entry into target cells and the subsequent production of new virions, our model provides a comprehensive understanding of the infection process. Our study focuses on investigating the stability of two crucial equilibrium states the infection-free and endemic equilibriums. To analyze the infection-free equilibrium, we utilize the LaSalle invariance principle. Further, we prove that if reproduction is less than unity, the disease free equilibrium is locally and globally asymptotically stable. To ensure numerical accuracy and preservation of essential properties from the continuous mathematical model, we use a spectral scheme having a higher-order accuracy. This scheme effectively captures the underlying dynamics and enables efficient numerical simulations.

Juvenile Dermatomyositis Presenting As Generalized Poikiloderma: A Case Report.

Juvenile dermatomyositis (JDM) is a chronic autoimmune inflammatory disorder and is considered the most common form of idiopathic inflammatory myopathies. JDM primarily affects the skin and the skeletal muscles. Characteristic signs and symptoms include Gottron papules, heliotrope rash, calcinosis cutis, and symmetrical proximal muscle weakness. However, JDM presenting with generalized scaly poikeloderma is an unfamiliar presentation. Herein we report a 14-month-old female toddler presented with generalized progressive asymptomatic scaly mottled violaceous patches (poikilodermatous) that started when she was seven months old. Her lab results were unremarkable. She was diagnosed with poikilodermatous skin rash with a differential diagnosis of Amyopathic dermatomyositis, poikilodermatous genodermatosis, and patch-stage mycosis fungoides. She was prescribed moisturizer creams only. A year later, during a follow-up, she presented with a full picture of JDM, with a history of scaly poikilodermatous skin patches that became more widespread, frequent choking during oral intake, and not being able to stand and sit unsupported. Laboratory workup was significant for low WBC and hemoglobin counts, along with elevated CPK, LDH, ferritin, CRP, and ESR levels. MRI revealed the right anterior thigh and vastus lateralis subcutaneous edema. Therefore, the child was diagnosed and treated as a case of JDM.

Biocompatibility and antioxidant activity of a novel carrageenan based injectable hydrogel scaffold incorporated with Cissus quadrangularis: an in vitro study.

BACKGROUND: Over the past years, polysaccharide-based scaffolds have emerged as the most promising material for tissue engineering. In the present study, carrageenan, an injectable scaffold has been used owing to its advantage and superior property. Cissus quadrangularis, a natural agent was incorporated into the carrageenan scaffold. Therefore, the present study aimed to assess the antioxidant activity and biocompatibility of this novel material. METHODS: The present in vitro study comprised of four study groups each constituting a sample of 15 with a total sample size of sixty (n = 60). The carrageenan hydrogel devoid of Cissus quadrangularis acted as the control group (Group-I). Based on the concentration of aqueous extract of Cissus quadrangularis (10% w/v, 20% w/v and 30% w/v) in carrageenan hydrogel, respective study groups namely II, III and IV were considered. Antioxidant activity was assessed using a 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay, whereas the biocompatibility test was performed using a brine shrimp lethality assay. The microstructure and surface morphology of the hydrogel samples containing different concentrations of Cissus quadrangularis aqueous extract was investigated using SEM. One-way ANOVA with the post hoc tukey test was performed using SPSS software v22. RESULTS: A significant difference (P < 0.05) in the antioxidant activity was observed among the study groups. Group III reported the highest activity, whereas the control group showed the least antioxidant activity. Additionally, a significant (P < 0.01) drop in the antioxidant activity was observed in group IV when compared with group III. While assessing the biocompatibility, a significant (P < 0.001) dose-dependent increase in biocompatibility was observed with the increasing concentration of aqueous extract of Cissus quadrangularis. SEM analysis in group III showed even distribution throughout the hydrogel although the particles are close and densely arranged. Reduced antioxidant activity in group IV was probably due to clumping of the particles, thus reducing the active surface area. CONCLUSION: Keeping the limitations of in vitro study, it can be assumed that a carrageenan based injectable hydrogel scaffold incorporated with 20% w/v Cissus quadrangularis can provide a favourable micro-environment as it is biocompatible and possess better antioxidant property.

Body mass index among elderly population and its association with neurological and musculoskeletal diseases in Aseer, Saudi Arabia.

Introduction: An increase in BMI in the elderly may reduce life expectancy and increase the risk of death, cardiovascular disease, and metabolic syndrome. Frailty index, body weight, and pain levels all seem to be linked. Excessively low or high body weight may cause muscle weakness and decrease physical activity, placing the elderly at risk for frailty. Methodology: This was a cross-sectional study to investigate BMI among the elderly and neurological and musculoskeletal diseases in the Aseer region, Saudi Arabia conducted during the period from 5 January, 2020 to 26 February, 2020. The data were collected using a self-administered pre-designed questionnaire, and 503 full forms of eligible subjects were included. Results: A total of 503 participants were included in this study, 61.2% of them were female, with a mean age of 67 ± 9. The mean BMI was 31.1 ± 7.5. Parkinsonism and hemiplegia were significantly associated with BMI (P = 0.003) and (P = 0.027), respectively. Osteoporosis and participants with no musculoskeletal problems were significantly associated with BMI (P = 0.001) and (P = 0.003), respectively. Conclusion: We found a significant association between Parkinsonism and hemiplegia and BMI as these conditions were more common among overweight patients. Moreover, osteoporosis was also significantly associated with BMI, and most of the patients with osteoporosis were underweight.

Vertical Load and Torque during Postspace Preparation and Their Influence on Microcrack Development.

PURPOSE: To investigate, in vitro, the magnitudes of vertical load and torque generated during post space preparation of root canal treated teeth and their influence on microcrack development. MATERIALS AND METHODS: Forty extracted premolars with single canals were decoronated. The roots were prepared using ProTaper Next system (Dentsply Sirona) to X3 file, obturated, and provisionalized. After a 3-week incubation period, the roots were distributed into 2 groups according to the post drill system used (ParaPost fiber post and RelyX fiber post). During post space preparation, the vertical load, torque, and preparation time were recorded. Before and after the post space preparation, the roots were imaged with micro-computed tomography (SkyScan 1172; Bruker micro-CT) to detect new microcracks. The data were analyzed using the Mann-Whitney U-test and chi-square test. RESULTS: In ParaPost and RelyX, the post space was prepared in 48.31 ±25.28 and 47.71 ±13.36 seconds, respectively (p = 0.360). The peak vertical load generated with ParaPost (20.23 ±7.80 N) was significantly lower than that of RelyX (29.43 ±5.82 N) (p = 0.010). The maximum torque attained with ParaPost (1.42 ±0.61 N.cm) was found to be significantly lower than that of RelyX (3.23 ±1.58 N.cm) (p = 0.000). No post drill fracture or visible deformation was noticed throughout the experiment. New microcracks were found in three ParaPost samples only. CONCLUSIONS: The choice of postdrill influenced the loads and torques generated during postspace preparation. The ParaPost system showed favorably lower load and torque values during the postspace preparation compared with the RelyX system.

Designing a Band for Vehicles' Drivers Induced by Ultraviolet and Infrared Radiations.

Background: Solar radiations that reach the Earth can be divided into ultraviolet, visible light, and infrared. Overexposure to these radiations can facilitate adverse skin diseases such as sunburn, skin cancer, and photoaging. People who drive vehicles for an extended period are likely to develop skin cancer in the exposed body area. Method: This research proposes a wearable protective device around the upper arm to measure the transmitted radiation through the front and the side windows. A novel skin type classification algorithm using a color sensor was created to provide an accurate skin type identification. Also, the device was programmed to calculate the time before sunburn occurrence based on the ultraviolet index, sunscreen's sun protection factor, and skin type. Results: The prototype was tested inside a Toyota Camry model 2001 vehicle with an accuracy of 97%. The front window had transmitted more infrared radiation compared to the side window. The highest recorded value was 76.76 mW/cm2. On the other hand, the side window had transmitted more ultraviolet compared to the front window as it lacks the protective polyvinyl butyral layer that the front window has. The highest recorded ultraviolet index was 3.5. Conclusion: These results highlight the importance of wearing the designed solar band and using appropriate UV and IR protection while driving a vehicle to prevent skin diseases from occurring.

Cutaneous Features of Anti-MDA-5 Antibody-Positive Amyopathic Dermatomyositis in a Sudanese Patient.

Clinically amyopathic dermatomyositis (CADM) is a rare form of DM characterized by unique cutaneous and pulmonary features with no muscle involvement. A subset of patients with CADM has a specific antibody known as anti-melanoma differentiation-associated protein 5 (MDA5). The systemic associations of anti-MDA-5 CADM warrant an early recognition and management to prevent fetal sequelae. It is seen more commonly in white and Asian female individuals. The clinical features of anti-MDA5 antibody-positive CADM in other ethnic groups are not well reported. Here, we describe a case of CADM with identified autoantibodies against MDA5 in a Sudanese female patient presenting with characteristic cutaneous features in association with MDA5 autoantibodies: ulcerated Gottron's papules, painful palmar papules, shawl sign, and heliotrope sign. No evidence of pulmonary or systemic involvement was identified. Treatment with prednisolone and mycophenolate mofetil was initiated. This case emphasizes the importance of keeping a high level of suspicion and to recognize the unique clinical feature of this type of DM aiding in early treatment and preventing fatal outcomes.

Oral and oropharyngeal cancer: Knowledge, attitude and practices among medical and dental practitioners.

BACKGROUND: Oral and oropharyngeal cancer are significant health problems. They are both life-threatening conditions usually diagnosed at an advanced stage causing survival rates to decline. AIM: To assess and compare practices, knowledge and attitude regarding oral and oropharyngeal cancer between dental and medical practitioners. METHODS: A cross-sectional study was conducted to assess knowledge, attitude and practices of oral and oropharyngeal cancer among dental and medical practitioners at King Abdulaziz Medical City, Riyadh, Saudi Arabia. 360 participants were included in the study using a convenient sampling technique. Participants were approached in their clinics and printed self-administered questionnaire were handed over to them after signing a written consent form. Frequency distribution and Chi-Square test were used for the statistical analysis and the level of significance was set at P value of .05 or less. RESULTS: A total of 174 participants responded. Assessment of oral and oropharyngeal cancer knowledge between dental practitioners and medical practitioners showed comparable results. Regarding practices, a significant difference was seen between medical practitioners and dental practitioners in determining the duration of intra-oral ulcer to consider urgent referral (P = .006) and in number of referrals made in relation to suspicious oral lesions (P = .002). Moreover, a significant difference (P = .006) was seen between medical practitioners and dental practitioners in determining the duration of intra-oral ulcer to consider urgent referral. CONCLUSION: Medical and dental practitioners showed areas of differences in practice, attitude and knowledge of oral and oropharyngeal cancer that when addressed would lead to improved survival rates.