A Study about the Effect of Addition of Carbon Nanofibers on the Strain-Rate Sensitivity of Thermoplastic Polymer Matrix Nanocomposites Manufactured by Ultrasonication Process

Thermoplastic polymers have been widely used in the industry due to their high toughness and impact resistance along with their remolding capabilities as compared to thermoset polymers, which also makes them an attractive choice for polymer composites. Many desirable features of thermoplastic polymers like ease of processing, low weight and cost, and corrosion resistance make thermoplastics a viable option for applications in the automotive, aerospace, sporting goods and many other industries. To further increase the mechanical, thermal and electrical properties of thermoplastic polymers, nanomaterials are added to the polymer matrix that can improve these properties at very low loading levels as compared to conventional fillers. In this work, Polypropylene (PP), a semi-crystalline thermoplastic known for its balance of strength, modulus and chemical resistance has been used as the polymer matrix. It is one of the most widely used thermoplastic polymers in several industries as it shows a good combination of stiffness, toughness and creep resistance along with being light-weight and cost effective. Carbon Nanofibers have been used as the nanomaterial in this work for understanding the effect of nanomaterials to mechanical properties of the polymer matrix. Thermoplastics, including Polypropylene, exhibit varying mechanical properties based on the different loading rates that they are subjected to. Polymers experience stress relaxation at constant strains and creep under constant load due to their viscoelastic nature, i.e. they exhibit properties both of an elastic solid and a viscous liquid. The stress relaxations are distinct for different polymers and are divided into unique processes that lead to a strain-rate dependency of the semi-crystalline polymer which has been studied in this work. To fabricate these nanocomposites, ultrasound-assisted mixing has been used to reduce the processing time, utilizing the well-known dispersive qualities of ultrasound in solutions. Ultrasound-assisted mixing, as a processing technique for directly manufacturing polymer matrix nanocomposites has not been studied much in the literature. Ultrasonication in polymer solutions can also be responsible for polymer degradation due to its cavitation effects. To understand the effects of dispersion and polymer degradation caused by ultrasonication, mechanical mixing of polymer solutions has also been used as a counterpart to the ultrasonication process. For studying the effects of processing and nanomaterial addition on the strain-rate dependency of the polymer matrix, tensile tests were conducted using injection molded dog-bone samples made as per the ASTM D638 V standards. For manufacturing these dog-bone samples, an injection mold was designed and manufactured based on the statistical analysis of simulations conducted using Moldex 3D, a polymer melt-flow simulating software. Tensile strength, elongation at break and the tensile modulus values have been used as the basis for comparison. To understand the strain rate dependency of the polymer and its nanocomposite, quasi-static strain rates varying from 10-4 to 10-1 s-1 have been utilized. Thermal Gravimetric Analysis (TGA) has also been conducted for studying the effects on the thermal properties of the polymer. Polypropylene has shown a visible response to varying strain rates as expected, as the strength and modulus of the polymer increases with increasing strain rate, while the elongation decreases. Ultrasonically processed polymer and its nanocomposites also show a similar linearity in the strain-rate dependency as the pure polymer. The effects of ultrasonication on the polymer degradation have been presented along with the effects of addition of nanomaterials. Mechanical and thermal properties have been discussed based on the tensile tests and TGA. Conclusions and future recommendations are presented based on the observations done

Novel mutation predicted to disrupt SGOL1 protein function

Cell cycle alterations are the major cause of cancers in human. The proper segregation of sister chromatids during the cell division process defines the fate of daughter cells which is efficiently maintained by various proteomic complexes and signaling cascades. Shugosin (SGOL1) is one among those proteins which are required for phosphatise 2A protein (PP2A) localization to centromeres during division. This localization actively manages the adherence of sister chromatids at the centromeric region until the checkpoint signals are received. Wide evidences of SGOL1 genomic variants have been studied for their correlation with chromosomal instability and chromatid segregation errors. Here we used computational methods to prioritize the Single Nucleotide Polymorphism’s (SNP’s) capable of disrupting the normal functionality of SGOL1 protein. L54Q, a mutation predicted as deleterious in this study was found to be located in N-terminal coiled coil domain which is effectively involved in the proper localization of PP2A to centromere. We further examined the effect of this mutation over the translational efficiency of the SGOL1 coding gene. Our analysis revealed major structural consequences of mutation over folding conformation of the 3rd exon. Further we carried molecular dynamic simulations to unravel the structural variations induced by this mutation in SGOL1 N-terminal coiled coil domain. Root mean square deviation (RMSD), root mean square fluctuation (RMSF), H-Bond scores further supported our result. The result obtained in our study will provide a landmark to future research in understanding genotype-phenotype association of damaging non-synonymous SNPs (nsSNPs) in several other centromere proteins as done in SGOL1 and will be helpful to forecast their role in chromosomal instabilities and solid tumor formation.Keywords: SGOL1; Molecular Dynamics Simulation; Gromacs; PhD-SNP; SIFT; Polyphen; MutPredThe Egyptian Journal of Medical Human Genetics (2013) 14, 149–15

Salvaging collateral damage by COVID-19 pandemic in form of exposed silicone ear framework in 33-year post reconstructed ear

Total ear reconstruction is being practiced by different techniques. Ready to use Silicone ear framework (Silastic ear framework by Dow corning) was being used frequently by Plastic surgeons in the eighties and nineties of the twentieth century. Framework exposure, either due to skin necrosis or due to infection used to be the commonest complication in the early postoperative period. A follow-up case of a 50 year old male patient, our 33 years follow up case of Total ear reconstruction by silicone ear framework implantation presented to us with exposed silicone framework and infection. Due to constant use of facemask with elastic ear loop for support during COVID-19 pandemic. The exposed infected implant successfully salvaged using negative pressure wound therapy. In all cases of autologous or alloplastic ear reconstruction, we strictly recommend not to use facemasks with elastic ear loops. If a facemask has to be used it should have a head loop or to be used with an ear protector. 

Damage suffered by Hanuman Dhoka after the 2015 Nepal Earthquakes

The current report presents findings by the ICCROM-ICOMOS-Smithsonian Institute team thatvisited some of the interior areas of Hanuman Dhoka after the April/May 2015 earthquakes on the26th of May 2015. The purpose of the visit was to assess the stability conditions of the interior areasof Hanuman Dhoka in order to witness the overall damage of the movable heritage and to analysethe possibility of evacuating and rescuing it. The visit was requested by the Department ofArchaeology of Nepal and the members of the ICCROM-ICOMOS-Smithsonian Institute team thatvisited the building were escorted by museum staff members.Given the high national significance of the Hanuman Dhoka palace and museum buildings, it isimportant that emergency stabilization of the heritage structures and collections is addressed in aholistic way. The aim of the first aid should be to assess and document damage using pastdocumentation, prevent further damage and promote early recovery through prioritization ofconservation treatments (of buildings and collections), and ensure business continuity throughcreative use/reuse while the stabilization and recovery work is underway

Photographic Evaluation, Analysis and Comparison of Aesthetically Pleasing Smiles: A Prospective Study

Objective:To evaluate the differences in aesthetically pleasing smiles and compare the smile arc parameters in males and females by dental specialists using photographs.Methods:The study was conducted on 500 North Indian subjects (Indo-Aryan race; 212 males and 288 females) aged 17-25 years (mean age, males=21.1 years; females=23.4 years), with reasonably pleasing smiles. The facial photographs were taken using a DSLR camera. The standardized photographs were shown to 30 judges for evaluation and rated using the visual analog scale. The smiles were categorized into attractive, fair, and average. The quantification of the smile characteristics was done by using an objective method that involved identifying consonant and non-consonant smiles.Results:The association between smile arc and smile attractiveness was significant (p=0.018) in females. The buccal corridor width was higher among those with fair to attractive smiles as compared with those with an average smile (p=0.018). Most subjects with an attractive smile had a smile arc parallel to the upper lip as compared with most subjects with a fair or average smile who did not have the smile arc in parallel (p=0.006).Conclusion:Most females were in the fair to attractive category whereas most males were in the average to fair category. The buccal corridor width was found to be higher among those with a fair to attractive smile as compared with those with an average smile. There was an association between smile arc and smile attractiveness in females

Patients Prefer a Virtual Reality Approach Over a Similarly Performing Screen-Based Approach for Continuous Oculomotor-Based Screening of Glaucomatous and Neuro-Ophthalmological Visual Field Defects

Standard automated perimetry (SAP) is the gold standard for evaluating the presence of visual field defects (VFDs). Nevertheless, it has requirements such as prolonged attention, stable fixation, and a need for a motor response that limit application in various patient groups. Therefore, a novel approach using eye movements (EMs) – as a complementary technique to SAP – was developed and tested in clinical settings by our group. However, the original method uses a screen-based eye-tracker which still requires participants to keep their chin and head stable. Virtual reality (VR) has shown much promise in ophthalmic diagnostics – especially in terms of freedom of head movement and precise control over experimental settings, besides being portable. In this study, we set out to see if patients can be screened for VFDs based on their EM in a VR-based framework and if they are comparable to the screen-based eyetracker. Moreover, we wanted to know if this framework can provide an effective and enjoyable user experience (UX) compared to our previous approach and the conventional SAP. Therefore, we first modified our method and implemented it on a VR head-mounted device with built-in eye tracking. Subsequently, 15 controls naïve to SAP, 15 patients with a neuro-ophthalmological disorder, and 15 glaucoma patients performed three tasks in a counterbalanced manner: (1) a visual tracking task on the VR headset while their EM was recorded, (2) the preceding tracking task but on a conventional screen-based eye tracker, and (3) SAP. We then quantified the spatio-temporal properties (STP) of the EM of each group using a cross-correlogram analysis. Finally, we evaluated the human–computer interaction (HCI) aspects of the participants in the three methods using a user-experience questionnaire. We find that: (1) the VR framework can distinguish the participants according to their oculomotor characteristics; (2) the STP of the VR framework are similar to those from the screen-based eye tracker; and (3) participants from all the groups found the VR-screening test to be the most attractive. Thus, we conclude that the EM-based approach implemented in VR can be a user-friendly and portable companion to complement existing perimetric techniques in ophthalmic clinics

Prevalence of sustained hypertension and obesity among urban and rural adolescents: a school-based, cross-sectional study in North India.

OBJECTIVE: Recent data on sustained hypertension and obesity among school-going children and adolescents in India are limited. This study evaluates the prevalence of sustained hypertension and obesity and their risk factors among urban and rural adolescents in northern India. SETTING: A school-based, cross-sectional survey was conducted in the urban and rural areas of Ludhiana, Punjab, India using standardised measurement tools. PARTICIPANTS: A total of 1959 participants aged 11-17 years (urban: 849; rural: 1110) were included in this school-based survey. PRIMARY AND SECONDARY OUTCOME MEASURES: To measure sustained hypertension among school children, two distinct blood pressure (BP) measurements were recorded at an interval of 1 week. High BP was defined and classified into three groups as recommended by international guidelines: (1) normal BP: 95th percentile. The Indian Academy of Pediatrics classification was used to define underweight, normal, overweight and obesity as per the body mass index (BMI) for specific age groups. RESULTS: The prevalence of sustained hypertension among rural and urban areas was 5.7% and 8.4%, respectively. The prevalence of obesity in rural and urban school children was 2.7% and 11.0%, respectively. The adjusted multiple regression model found that urban area (relative risk ratio (RRR): 1.7, 95% CI 1.01 to 2.93), hypertension (RRR: 7.4, 95% CI 4.21 to 13.16) and high socioeconomic status (RRR: 38.6, 95% CI 16.54 to 90.22) were significantly associated with an increased risk of obesity. However, self-reported regular physical activity had a protective effect on the risk of obesity among adolescents (RRR: 0.4, 95% CI 0.25 to 0.62). Adolescents who were overweight (RRR: 2.66, 95% CI 1.49 to 4.40) or obese (RRR: 7.21, 95% CI 4.09 to 12.70) and reported added salt intake in their diet (RRR: 4.90, 95% CI 2.83 to 8.48) were at higher risk of hypertension. CONCLUSION: High prevalence of sustained hypertension and obesity was found among urban school children and adolescents in a northern state in India. Hypertension among adolescents was positively associated with overweight and obesity (high BMI). Prevention and early detection of childhood obesity and high BP should be strengthened to prevent the risk of cardiovascular diseases in adults

Effect of matrix shrinkage on permeability of coalbed methane reservoirs

The dynamic nature of coalbed methane reservoir permeability makes the continuous modeling of the flow process difficult. Knowledge of conventional reservoir modeling is of little value because the gas storage and flow mechanisms in coal are remarkably different. Field observations suggest that the gas productivity does not decline with time as expected. An increasing permeability is a possible explanation. This laboratory study is aimed at measuring the volumetric changes in coal matrix resulting from gas desorption, its impact on coal porosity and permeability, and an estimate of the stage when the effect is significant. Results using cylindrical samples of coal suggest that coal matrix shrinks with desorption of gas. The shrinkage is linearly proportional to the quantity of gas desorbed. Using the measured changes in matrix volume, variations in total and cleat porosity were estimated and found to increase significantly with desorption. These changes should, therefore, be used as input when simulating long-term gas production