Polyolefin Based Copolymers as Matrix Component in Coir Fiber Reinforced Composites

Maitrayee Saikia,Nilakshi Kakati,Urmilla Baruah,Lachit Phukan,Prakash J. Saikia,Shashi D. Baruah 한국섬유공학회 2020 Fibers and polymers Vol.21 No.9

Natural fiber reinforced polymer composites have attracted much attention in global market as they possess muchadvantageous characteristics over conventional composite materials in terms of eco-friendliness, light weight, low cost, goodmechanical properties and biodegradability. Among natural fibers, the surface properties of coir fiber can be easily improvedwhen the fiber is reinforced with polymer matrix. Therefore, the aim of the present investigation is to develop a coir fibercomposite reinforced with polyolefin based copolymers (PCs) and investigate the influence of coir fiber loading onmechanical as well as on water absorption behavior of the composites. Three types of PCs were synthesized using differentcontrolled radical polymerizations (CRP) techniques and used as matrix in composite preparation. Poly(ethylene-co-butylmethacrylate) synthesized via dual concurrent atom transfer radical polymerization (ATRP)-reversible addition fragmentationchain transfer (RAFT) polymerization as well as RAFT mediated miniemulsion polymerization and poly(1-octene-co-butylmethacrylate) synthesized via RAFT polymerization were used as matrix component to prepare the composite materials. Theperformance evaluation of these PCs in the prepared composites was also compared. The composites were prepared usingcompression moulding method by reinforcing with 65, 70, 75 and 80 wt. % coirfiber loading. Analysis by universal testingmachine (UTM) showed that the tensile strength and flexural strength of composites were decreased with increase in the fiberloading. Highest tensile as well as flexural strength was observed for 65 wt. % coir fiber loading. Among the three types ofPCs matrixes, poly(ethylene-co-butyl mehacrylate) synthesized by RAFT mediated miniemulsion polymerization showedhighest tensile and flexural strengths in the prepared composite. PCs reinforced coir fiber composites showed the potentialadvantage over coir fiber composites with commercial Araldite 506 resin as matrix component in terms of tensile as well asflexural properties. The morphological study by scanning electron microscopy (SEM) analysis confirmed the good adhesionbetween the PCs matrixes and the coir fibers in the prepared composites. X-ray photoelectron spectroscopy (XPS) analysisdemonstrated significant changes occurred on the surface of coir fiber due to reinforcement of PCs matrixes and X-raydiffraction studies showed the amorphous natures of the composites without any crystallinity. Thermogravimetric analysisresults revealed that due to penetration of PCs matrix into the coir fiber, the thermal stability of composites were significantlyincreased. Furthermore, water absorption properties of composites were also investigated. Based on these results thesynthesized PCs/coir composite materials are found to be suitable for its use as hardboards and in different householdfurniture materials.

Umbilical cord ulceration: An underdiagnosed entity

( Barkha Maheshwari ),( Maitrayee Roy ),( Shipra Agarwal ),( S Devi ),( Ashu Singh ),( Nita Khurana ),( Sangeeta Gupta ) 대한산부인과학회 2016 Obstetrics & Gynecology Science Vol.59 No.5

Umbilical cord ulceration is a rare condition presenting with sudden fetal bradycardia due to fetal hemorrhage and in most cases leading to intrauterine death. A strong association with intestinal atresia has been reported. Most cases present after 30 weeks of gestation, with preterm labor or rupture of membranes followed by sudden fetal bradycardia. We report two such cases of umbilical cord ulceration and review the available literature. One of the cases interestingly presented at 26 weeks, much earlier than what is reported in the world literature. In view of high perinatal mortality and morbidity, awareness of this condition is mandatory for timely and appropriate management to improve the fetal outcome.

Breast Cancer Scenario in a Regional Cancer Centre in Eastern India over Eight Years - Still a Major Public Health Problem

Datta, Karabi,Choudhuri, Maitrayee,Guha, Subhas,Biswas, Jaydip Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

In spite of screening and early diagnostic tests, the upward trend of breast cancer has become a matter of great concern in both developed and developing countries. The data collected by Population Based Cancer Registry in Chittaranjan National Cancer Institute, a regional cancer centre in Kolkata, from 1997 to 2004 gives an insight about the scenario of Breast Cancer in this part of Eastern India.The total no of female breast cancer cases were steadily increasing from 1997 to 2001 and only slightly lower from 2002 to 2004. and majority were in the 40-49 year old age group during this period. The next most commonly affected age group was 50-59 years. Regarding the distribution according to treatment, the main modality was surgery and radiotherapy followed by combined surgery, chemotherapy and radiotherapy and then combined surgery and chemotherapy. The commonest type was ductal followed by lobular cancer. In this eight year study in CNCI, status of patients on last day of the respective year was assessed. Number of patients alive was 43.5% in 1997. The percentage gradually increased up to 2000 and then gradually decreased to 47.4% in 2004. Also with every passing year, percentage mortality gradually decreased from 25.7% in 1997 to 16.8% in 2004. Better pattern of care (diagnosis and treatment) was reflected in this picture. However, lost to follow up, which also implies non compliance to treatment, increased to 30.8% in 1997 to 35.8% in 2004. Due to the small number of male breast cancers, only female cases were considered. In conclusion, breast cancer continues to be a major problem in Kolkata, India.

Primary Rectal Adenocarcinoma Metastasizing to Bilateral Breasts - a Rare Case Demonstrated by ¹⁸F-FDG PET/CT

Soundararajan, Ramya,Arora, Saurabh,Das, Chandan Jyoti,Roy, Maitrayee,Kumar, Rakesh,Bal, Chandrasekhar The Korea Society of Nuclear Medicine 2016 핵의학 분자영상 Vol.50 No.2

Quantitative histology-based classification system for assessment of the intestinal mucosal histological changes in patients with celiac disease

Prasenjit Das,Gaurav PS Gahlot,Alka Singh,Vandana Baloda,Ramakant Rawat,Anil K Verma,Gaurav Khanna,Maitrayee Roy,Archana George,Ashok Singh,Aasma Nalwa,Prashant Ramteke,Rajni Yadav,Vineet Ahuja,Vishnu 대한장연구학회 2019 Intestinal Research Vol.17 No.3

Background/Aims: The existing histological classifications for the interpretation of small intestinal biopsies are based on qualitative parameters with high intraobserver and interobserver variations. We have developed and propose a quantitative histological classification system for the assessment of intestinal mucosal biopsies. Methods: We performed a computer-assisted quantitative histological assessment of digital images of duodenal biopsies from 137 controls and 124 patients with celiac disease (CeD) (derivation cohort). From the receiver-operating curve analysis, followed by multivariate and logistic regression analyses, we identified parameters for differentiating control biopsies from those of the patients with CeD. We repeated the quantitative histological analysis in a validation cohort (105 controls and 120 patients with CeD). On the basis of the results, we propose a quantitative histological classification system. The new classification was compared with the existing histological classifications for interobserver and intraobserver agreements by a group of qualified pathologists. Results: Among the histological parameters, intraepithelial lymphocyte count of ≥25/100 epithelial cells, adjusted villous height fold change of ≤0.7, and crypt depth-to-villous height ratio of ≥0.5 showed good discriminative power between the mucosal biopsies from the patients with CeD and those from the controls, with 90.3% sensitivity, 93.5% specificity, and 96.2% area under the curve. Among the existing histological classifications, our quantitative histological classification showed the highest intraobserver (69.7%–85.03%) and interobserver (24.6%–71.5%) agreements. Conclusions: Quantitative assessment increases the reliability of the histological assessment of mucosal biopsies in patients with CeD. Such a classification system may be used for clinical trials in patients with CeD.