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Open access

Jitendra Katariya and Raj Kumar Arya

Abstract

Four binary polymer -solvent systems, poly(styrene)-tetrahydrofuran, poly(styrene) - p-xylene, poly(methyl methacrylate) - ethylbenzene and poly(methyl methacrylate) - tetrahydrofuran, systems have been studied. It has been observed that thicker coatings will retain a higher amount of the residual solvent as compared to thinner coatings. In the case of poly(styrene)-tetrahydrofuran coating residual solvent remaining within the coatings were 9.09% and 4.74% for the coatings of the thicknesses of 967 micron and 559 micron, respectively. Similar trends were also observed in the case of poly(methyl methacrylate)-ethylbenzene, poly(methyl methacrylate)-tetrahydrofuran, and poly(styrene)-p-xylene systems.

Open access

N. Mohan Raj, L.A. Kumaraswamidhas and S. Arungalai Vendan

Abstract

This research study aims to investigate the mechanical and metallographical aspects of ultrasonic welding of Cu-Cu wires. Experimental trials have been conducted and observations have been recorded as a database that collates parametric, quality and strength aspects of various weldments. Destructive testing and metallurgical characterizations have been carried out to examine the strength and integrity of the weldment. The key focus of this research attempt is laid on determining and evaluating the factors that governs the strength of the weldment. Metallurgical characterizations reveal vital information on the weld integrity and the extent of grain distribution. Further, FEM is employed to understand the deformation and thermal aspects involved in Cu-Cu welding using ultrasonics. The numerical model may provide an insight into the thermal phenomenon governing the joining process and subsequently estimation of the impact. Response surface methodology is employed to identify the parametric interdependencies and subsequently determine the optimized range.

Open access

Senapathyhally Nagaraju Lavanya, Sathyanarayana Niranjan-Raj, Siddaiah Chandra Nayaka and Kestur Nagaraju Amruthesh

Abstract

The obligate oomycete Sclerospora graminicola (Sacc.) Schroet, is the incitant of downy mildew disease, which is the main constraint in pearl millet production worldwide. Different elicitors from Trichoderma hamatum UOM 13, e.g. mycelial extract and cell wall glucans, were assessed for their resistance elicitation efficiency and the possible underlying mechanisms. Both mycelial extract and cell wall glucans of T. hamatum UOM 13 positively influenced seed quality parameters of pearl millet, significantly enhanced seed germination and seedling vigor in comparison to the untreated control. Seed priming with cell wall glucan elicitors of T. hamatum UOM 13 suppressed downy mildew on susceptible pearl millet seedlings under greenhouse conditions by induction of systemic host resistance. Of the different elicitor delivery methods tested, transplant root dip was more effective than seed treatment and foliar spray. A combination of transplant root dip + seed treatment + foliar spray was significantly more effective than the single delivery methods. The induced resistance corresponded to up regulation of genes of important defense proteins upon pathogen inoculation. Transcripts of genes of defense enzymes glucanase, phenylalanine ammonia lyase, peroxidase and polyphenoloxidase were significantly increased due to the T. hamatum UOM elicitor effect. Expression of hydroxyproline-rich glycoprotein genes, known to play an important role in cell wall cross-linking, were also up regulated in response to T. hamatum UOM cell wall glucan treatment. This study emphasizes the role of T. hamatum UOM as a potential elicitor of downy mildew resistance in pearl millet and presents novel insights into the involvement of important defense proteins mediating such as resistance trigger.

Open access

Lana Filipovic, Sandra Arandelovic, Nevenka Gligorijevic, Ana Krivokuca, Radmila Jankovic, Tatjana Srdic-Rajic, Gordana Rakic, Zivoslav Tesic and Sinisa Radulovic

Abstract

Background. In our previous study we reported the synthesis and cytotoxicity of two trans-platinum(II) complexes: trans-[PtCl2(3-acetylpyridine)2] (1) and trans-[PtCl2(4-acetylpyridine)2] (2), revealing significant cytotoxic potential of 2. In order to evaluate the mechanism underlying biological activity of both trans-Pt(II) isomers, comparative studies versus cisplatin were performed in HeLa, MRC-5 and MS1 cells.

Materials and methods. The cytotoxic activity of the investigated complexes was determined using SRB assay. The colagenolytic activity was determined using gelatin zymography, while the effect of platinum complexes on matrix metalloproteinases 2 and 9 mRNA expression was evaluated by quantitative real-time PCR. Apoptotic potential and cell cycle alterations were determined by FACS analyses. Western blot analysis was used to evaluate the effect on expression of DNA-repair enzyme ERCC1, and quantitative real-time PCR was used for the ERCC1 mRNA expression analysis. In vitro antiangiogenic potential was determined by tube formation assay. Platinum content in intracellular DNA and proteins was determined by inductively coupled plasma-optical emission spectrometry.

Results. Compound 2 displayed an apparent cytoselective profile, and flow cytometry analysis in HeLa cells indicated that 2 exerted antiproliferative effect through apoptosis induction, while 1 induced both apoptosis and necrosis. Action of 1 and 2, as analyzed by quantitative real-time PCR and Western blot, was associated with down-regulation of ERCC1. Both trans-complexes inhibited MMP-9 mRNA expression in HeLa, while 2 significantly abrogated in vitro tubulogenesis in MS1 cells. Conclusions. The ability of 2 to induce multiple and selective in vitro cytotoxic effects encourages further investigations of trans-platinum(II) complexes with substituted pyridines.

Open access

Shabil Mustafa, AC Raj, Jayaprasad Anekar, Darshan Devang Divakar, Abdulaziz Abdullah Al Kheraif, Ravikumar Ramakrishnaiah, Aftab Ahmed Khan, Obaid Abdullah Alshahrani and Narendra Prakash Rai

Abstract

Background

Assessing the maturational status and pubertal growth spurt of a patient has considerable influence on diagnosis, treatment planning, and the outcome of orthodontic treatment.

Objectives

To assess the usefulness of panoramic radiographs as a tool to estimate the growth and to ascertain the importance of tooth calcification stages as an indicator of maturity by using digital panoramic radiographs.

Methods

We compared the dental maturity assessed by calcification of mandibular canine, first premolar, second premolar, and second molars using digital panoramic radiographs and skeletal maturity assessed by cervical vertebral maturation stages using lateral cephalograms and hand-wrist radiographs. Skeletal maturity was assessed using a cervical vertebrae maturation technique; hand-wrist maturity was evaluated using Fishman skeletal maturity indicators. Dental maturity was estimated according to guidelines of Demirjian. Spearman rank-order correlation coefficients were used to determine the correlation between tooth calcification stages and skeletal maturity assessed on panoramic radiographs, lateral cephalograms, and hand-wrist radiographs of 60 patient participants, including 45 boys and 15 girls.

Results

The panoramic radiograph is a reliable tool with which to estimate of growth and development of boys.

Conclusion

The relationship between tooth calcification stages and the skeletal maturity indicators in boys allows clinicians to identify the stage of the pubertal growth from panoramic radiographs. It is appropriate to put these skeletal and dental maturation relationships into daily orthodontic diagnostic practice.