Pollen morphology of the genus Impatiens L. (Balsaminaceae) and its systematic implications

Pollen morphology of 18 species from the genus Impatiens collected from diff erent localities in Nilgiris, Tamil Nadu was evaluated using scanning electron microscopy (SEM) during the period of February 2017 to November 2019. From the observation of pollen it was found to be structurally monad; prolate, sub-prolate and prolate-spheroidal in equatorial view; and circular, rectangular, triangular, quinquangular, elliptic and quadrangular in polar view. The apertures varied from dicolpate, tricolpate to tetracolpate. The main ornamentation type was reticulate in most of the species except Impatiens fruticosa which showed echinate ornamentation. The variations in pollen structure within the species were useful for the identifi cation and classifi cation of the genus Impatiens. The high structural diversity renders important taxonomic value for species differentiation

Antifungal efficacy of marine seaweed extracts against Alternaria sesami and Macrophomina phaseolina in sesame (Sesamum indicum L.)

In Tamil Nadu sesame is cultivated in an area of 74376 ha with average productivity of 433 kg / ha. Productivity has remained stagnant over recent decades because of its susceptibility to biotic and abiotic stresses. Root-rot and leaf spot disease of sesame caused by Macrophomina phaseolina is most serious disease-causing losses in seed yield in sesame.   Diseases caused by fungi Alternaria sesami and Macrophomina phaseolina, which cause diseases with leaf spot and root rot, respectively, usually reduce its production.The antifungal effectiveness of methanolic seaweed extracts, namely from Sargassum myricocystum, which was collected from the Gulf of Mannar in Tamil Nadu, against various infections was assessed in this study. Soxhlet extraction was used to produce the extracts, which were then examined utilizing Gas Chromatography- Mass Spectrometry (GC-MS) analysis, poisoned food techniques and field and pot experiments. The growth of A. sesami (65.33 %) and M. phaseolina (24.44 %) was strongly suppressed by S. myricocystum extract at a 3 % concentration, according to in vitro screening. GC-MS profiling revealed important antifungal substances, such as phytol and squalene. Investigations in the field revealed that treated plants had a reduced incidence of disease and a higher yield, with significant defense against Alternaria leaf spot, powdery mildew and root rot. The structural damage to fungal mycelia and the preservation of plant tissue integrity were confirmed by histopathological and Scanning Electron Microscopy (SEM) investigations. According to these results, S. myricocystum has strong antifungal and biostimulant characteristics and can be used as a sustainable bioinoculant for integrated control of diseases in sesame cultivation

Antagonistic Property of Selected Herbal Combination for Substitute of Synthetic Antimicrobial Agents

The emergence and spread of bacterial strains of multi- drug resistant continues to challenge the healthcare sector of both developed and developing countries. Owing to this problem and concerning the side effects of synthetic antimicrobial agents, the current work was done with medicinal plants. The plant materials such as Terminalia bellerica, Withania somnifera, Madhuca longifolia and Sygyzium cumini was selected based on its potent antimicrobial activity. The best combination of the selected plants was evaluated for their antimicrobial activity. The phytochemical analysis of the selected combination showed the presence of phytoconstituents that are responsible for their biocidal activity. The Minimum inhibitory concentration (MIC) was studied for the selected herbal combination. The results recommend the use of selected plants at their best combination as a substitute to synthetic agents that can effectively prevent the microbial infestation. Keywords: Antimicrobial activity, Cross infection, Medicinal Plant, MIC, Phytochemical

Pollen morphology of the genus Impatiens L. (Balsaminaceae) and its systematic implications

Pollen morphology of 18 species from the genus Impatiens collected from different localities in Nilgiris, Tamil Nadu was evaluated using scanning electron microscopy (SEM) during the period of February 2017 to November 2019. From the observation of pollen it was found to be structurally monad; prolate, sub-prolate and prolate-spheroidal in equatorial view; and circular, rectangular, triangular, quinquangular, elliptic and quadrangular in polar view. The apertures varied from dicolpate, tricolpate to tetracolpate. The main ornamentation type was reticulate in most of the species except Impatiens fruticosa which showed echinate ornamentation. The variations in pollen structure within the species were useful for the identification and classification of the genus Impatiens. The high structural diversity renders important taxonomic value for species differentiation.</jats:p

The biomechanical study of cervical spine: A Finite Element Analysis

The biomechanical study helps us to understand the mechanics of the human cervical spine. A three dimensional Finite Element (FE) model for C3 to C6 level was developed using computed tomography (CT) scan data to study the mechanical behaviour of the cervical spine. A moment of 1 Nm was applied at the top of C3 vertebral end plate and all degrees of freedom of bottom end plate of C6 were constrained. The physiological motion of the cervical spine was validated using published experimental and FE analysis results. The von Mises stress distribution across the intervertebral disc was calculated along with range of motion. It was observed that the predicted results of functional spine units using FE analysis replicate the real behaviour of the cervical spine. </jats:p

The biomechanical effects of S-type dynamic cage using Ti and PEEK for ACDF surgery on cervical spine varying loads

Anterior cervical discectomy with fusion (ACDF) is the common method to treat the cervical disc degeneration. The most serious problems in the fusion cages are adjacent disc degeneration, loss of lordosis, pain, subsidence, and migration of the cage. The objective of our work is to develop the three-dimensional finite element (FE) model from C3-C6 and virtually implant a designed S-type dynamic cage at C4-C5 segment of the model. The dynamic cage design will provide mobility in the early stage after ACDF surgery. Titanium (Ti) and PEEK (polyether ether ketone) were used as the material property for the cages. We applied the physiological motions at different loads from 0.5, 1, 1.5, 2.0 Nm to evaluate the dynamic cage design and the biomechanical performances of the designed S-type dynamic cage. It was observed that in all the loading condition the range of motion in the adjacent level was maintained and the maximum stress at the adjacent disc was reduced. The clinical significance of the S-type dynamic cage is better stress profile at the fusion level and adjacent segments which translates into higher rate of fusion, lower risk of cage subsidence, lower risk of adjacent segment degeneration, and good mechanical stability. </jats:p