Preparation and mechanical properties of Nanoclay-MWCNT/Epoxy hybrid nanocomposites

[EN] Among the various kinds of reinforcing element, Multi Wall Carbon Nano-tubes (MWCNT) and Nanoclay have found much more attention as a filler element to upgrade the mechanical properties of polymer composite material. In this paper, production of hybrid nanocomposites and the effect of MWCNT and nanoclay on mechanical properties of hybrid nanocomposites have been evaluated. In hybrid nanocomposites, MWCNT and nanoclay are embedded in epoxy resin. The processing of hybrid nanocomposite is always been a difficult task for researcher to prepare defects free samples. Here, the processing of Epoxy/Nanoclay-MWCNT hybrid composites has been done by using homogenizer and ultrasonic techniques for complete dispersion of nanoparticles into epoxy resin. The MWCNT and nanoclay were embedded into epoxy resin in different weight fractions and mixtures were used for tensile test and hardness specimen production. The tensile modulus and tensile strength values have been calculated via tensile tests. The test result shows that tensile modulus of samples increases as the filler content increase up to certain extent but then start decreasing. Also the elongation reduces as the filler content rises in the epoxy which shows the brittleness present in the samples. Rockwell hardness on B-scale was conducted on Nanocomposite samples and found that increasing the filler content excessively does not improve hardness as much.Kumar, S.; Gupta, A. (2021). Preparation and mechanical properties of Nanoclay-MWCNT/Epoxy hybrid nanocomposites. Journal of Applied Research in Technology & Engineering. 2(1):17-21. https://doi.org/10.4995/jarte.2021.14239OJS172121Alsafee, A.B., Al-ajaj, I.A., Khalili, A.S. (2014). Concentration effect of multi walled carbon nanotube on mechanical properties of epoxies composites. 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Comparative Antiproliferative activity of aerial parts of few Apocynaceae plants in HepG2, HT29 and SK-OV3 Human cancer cell lines

Aims: Apocynaceae family is the 5th largest medicinal plant family rich in potent secondary metabolites such as Alkaloids, Cardiac glycosides,Terpenoids, irridoid/secoirridoids, flavonoids and Phenolic contents. The present study was aimed to evaluate and compare in-vitroantiproliferative activity of three plants of this family.Methods: Aerial parts of Carissa carandas Linn. (C), Nerium indicum Mill. (N) and Wrightia tinctoria RBr. (W), were collected and dried. Thepowdered drugs were extracted in Ethanol (1), 60% Ethanol (2) and Water (3). Estimation of Phytoconstituents performed using standardmethods. In-vitro cytotoxic activity performed using Sulphorhodamine B (SRB) assay in HepG2, HT29 and SKOV3 human cancer cell lines takingAdriamycin (ADR) as standard. For extracts, GI50 value ≤ 20μg/ml was considered to demonstrate activity.Results: For HepG2 cell line graphs and photomicrographs showed GI50 value as ADR=39.79, C1=2.5, N2=66.3, N3<10 and C2=C3= N1=W1-3>80. Also TGI for C1>80. The extracts, C1, C2, N1, N2, and N3 were found to possess activity against HepG2.These extracts were screened onHT 29 and SKOV3cell lines. The GI50 value observed was<10 for C1, N2, N3 and ADR in HT 29 and <10 for N3 and ADR in SK OV3 cell lines.Thus it was found that aqueous extract of Nerium indicum (N3) and Ethanolic extract of Carissa carandas (C1) were most cytotoxic extractsagainst all three cell lines.Conclusions: our study establishes that Apocynaceae family plants could be an important anticancer lead and could serve as Botanical drug forneoplasia.Keywords: Apocynaceae, SRB Assay, Phytoconstituents, Anticancer drug screening models, Hep G2, HT 29, SK-OV3, HCC

A new species of the genus Epistaurus (Orthoptera: Acrididae) from Central India

Epistaurus tinsensis sp. n. is described from Chhattisgarh, India. A key to the species of the genus from India is also provided

Thanatophoric dysplasia, an enigmatic dilemma: a case report

Thanatophoric dysplasia is a rare, fatal form of skeletal dysplasia that affects fetus in utero. It is characterized by marked underdevelopment of fetal skeleton and short limbs. This disorder can be diagnosed antenatally and the couple should be counselled for termination of pregnancy. 20 years old female came in her second trimester carrying an ultrasound report which showed features of thanatophoric dwarfism. She was advised to terminate her pregnancy but she decided to continue with her pregnancy. She was induced after 40 weeks and she delivered a stillborn baby with dwarf like features, a condition identified as thanatophoric dwarfism. Early diagnosis can be done by ultrasound as early as 13 weeks of gestation and since babies born with thanatophoric dysplasia have a very poor prognosis, couples should be counselled regarding early termination of pregnancy. 3D ultrasound scan and molecular analysis can also help identify this disorder

Plasma adrenocorticotropin (ACTH) values and cortisol response to 250 and 1 μ g ACTH stimulation in patients with hyperthyroidism before and after carbimazole therapy: Case-control comparative study

Context: Although the production and metabolic clearance rate of cortisol is increased during thyrotoxic state, the net effect on adrenocortical reserves is not clear. Objective: We assessed circulating ACTH levels, cortisol binding globulin (CBG), and adrenocortical reserves in hyperthyroid patients (before and after carbimazole therapy) and healthy controls. Design and Setting: This was a case-control investigative study in a tertiary care setting. Patients and Methods: Plasma ACTH and free cortisol index (FCI; serum cortisol/CBG) were measured in 49 consecutive patients with hyperthyroidism and 50 controls. ACTH1-24 stimulation tests (250 and 1 μ g) were carried out in the first 29 patients and 15 controls. Peak FCI less than the mean -3 SD of healthy controls was considered subnormal. ACTH1-24 stimulation tests were repeated in 24 patients in the euthyroid state. Results: The mean basal plasma ACTH and FCI were higher and CBG was lower in thyrotoxic patients in comparison with controls. The peak cortisol was less than 18 μ g/dl in 10 of 29 and 14 of 29 on 250 and 1 μ g ACTH1-24 stimulation. Peak FCI was subnormal only in three of 27 (11.1%) and two of 21 (7.4%) on 250 and 1 μg ACTH1-24 stimulation, respectively. The mean plasma ACTH, basal FCI, and subnormal peak FCI (two of the three) normalized after euthyroidism. Plasma ACTH and FCI did not correlate with severity of thyrotoxicosis. Conclusions: Up to 11% of thyrotoxics have subnormal peak FCI on ACTH1-24 stimulation. Such changes occur despite high basal plasma ACTH and FCI. Use of FCI, rather than total cortisol, is required for the interpretation of cortisol values in thyrotoxicosis due to the variation in CBG

Gastrointestinal stromal tumor causing ileo-ileal intussusception in an adult patient a rare presentation with review of literature

Gastrointestinal stromal tumors (GIST) are mesenchymal tumors occurring anywhere along the gastrointestinal tract and are believed to originate from the interstitial cells of Cajal. They commonly arise in the stomach or small intestine. The usual growth pattern is exophytic invading adjacent organs or perforation into the peritoneal cavity which may result in bleeding or obstructive symptoms. Intussusception and obstruction is a very uncommon presentation of these lesions because of their tendency to grow in an extraluminal fashion. We report an unusual case of 59 yrs old man presenting with acute small bowel obstruction, which on exploration was found to be due to ileo-ileal intussusception and the lead point of intussusception was a tumor, which was histologically diagnosed as GIS

20W Output Broadband Amplifier with Automatic Gain Control and Thermal Protection

The requirement is to explore concept, design, fabrication and testing of a common source class B, cwrf amplifier by using readily available MOSFET that can withstand a load mismatch at all phase angles with more than a VSWR of 20:1. This amplifier must give an output of more than 20W with 13dB gain in the frequency range of 28 to 46MHz i.e. 37 ± 9MHz. This module will make one of the stages for a multistage cascaded high power cwrf solid state amplifier. The amplifier must be over current and over voltage protected by using external self-regulated dc power supply at the drain. The amplifier MOSFET device is presently to be biased at the gate with a variable dc supply. This arrangement will make it gain controlled. This will be feed backed from the cwrf output so as to make it automatic gain controlled in future. Various techniques of sampling forward and reflected power at the output must also be explored. A thermoswitch at the heat sink of MOSFET is to be added along with necessary circuitry to regulate the operating temperature, thereby protecting the device from overheating

Validation of the use of POSSUM score in enteric perforation peritonitis - results of a prospective study

Introduction: The objective of the study was to present our last 5-years experience of peritonitis and validate POSSUM score in predicting mortality and morbidity in patients of enteric perforation (EP) peritonitis. Methods: Data was collected prospectively for all peritonitis cases admitted in single surgical unit from January 2005 to December 2009. Parameters for calculating POSSUM were also retrieved; in these patients, O:E (Observed vs. Expected) ratio of mortality and morbidity were estimated after calculating predicted mortality and morbidity by exponential regression equations. Results: 887 patients with peritonitis were admitted and treated in this unit during the 5 years of study period. Duodenal (n=431; 48%) followed by ileal (n=380; 42.8%) perforations were the commonest. Mean age of the patients was 34 years and 86% were males. Mean delay in presentation was 78.5 hrs. Mean duration of hospital and ICU stay was 13 and 7.2 days. Postoperative complications were seen in 481 (54%) patients, and 90 (10%) patients died. POSSUM scores and predicted mortality/morbidity were calculated in 380 patients of ileal perforation peritonitis; O:E ratio of mortality and morbidity were 0.47 and 0.85 in these patients. Conclusion: POSSUM and P-POSSUM are accurate tools for predicting morbidity and mortality respectively in EP patients. Though they may sometime over or under predict morbidity as well as mortality.Key words: Enteric perforation, Peritonitis, POSSUM , P-POSSU

Efficacy of ProTaper Retreatment System in Root Canals Obturated with Gutta-Percha Using Two Different Sealers and GuttaFlow

Objective. To compare the efficacy of ProTaper retreatment files in removing three different obturating materials. Study Design. Forty-five human, single-rooted premolars were divided into three experimental groups. Group 1 was obturated with gutta-percha and AH Plus sealer, Group 2 was obturated with gutta-percha and zinc oxide eugenol sealer, and Group 3 was obturated with GuttaFlow. Retreatment was done using the ProTaper universal rotary retreatment files. Root halves were visualized using magnifying loops at 3X magnification and optical stereomicroscope at 10X magnification. Images were analyzed using AutoCAD 2004 software to calculate area of the remaining debris in the canal. For statistical analysis were used variance test and ANOVA. Results. Total debris/canal area ratio between the three groups showed a statistically significant difference (P < 0.001). Conclusion. ProTaper retreatment system did not produce completely clean canals in any of the groups. However, it had the best efficacy towards removing silicon based obturating material GuttaFlow