Merin Mathew - Academia.edu (original) (raw)

Papers by Merin Mathew

Trends in biomaterials & artificial organs, 2020

Diagnostic nasal endoscopy and computed tomography of para nasal sinuses play an important role i... more Diagnostic nasal endoscopy and computed tomography of para nasal sinuses play an important role in the diagnosis and treatment of Chronic Rhinosinusitis (CRS). This study explains the importance of both, individually and together.The application of these diagnostic modalities is patient and disease dependent. Rather than competing with each other, they go hand in hand!

Poly methyl methacrylate (PMMA) is one of the most widely accepted biomaterial in prosthetic dent... more Poly methyl methacrylate (PMMA) is one of the most widely accepted biomaterial in prosthetic dentistry due to its acceptable advantages. However the conventional PMMA used are far from being ideal because of their inferior mechanical properties. So the present study is to determine the Vickers Hardness and specific wear rate of the silane treated E glass fiber reinforced PMMA. Vickers Hardness number and specific wear rate of PMMA denture base can be determined by varying the weight percentage and aspect ratio of glass fiber. To measure the Vickers hardness, specimens prepared using a standard rectangular mold of 62mm length, 10 mm breadth and 2.5 mm thickness. Vickers Hardness number measured using Vickers hardness test apparatus having square based diamond pyramid as indenter. For wear analysis, specimens prepared using a standard cylindrical mold of 8mm diameter and 25mm length. Specific wear rate measured after measuring the weight loss in the pin on disc method by Wear and Fric...

Journal of Evolution of medical and Dental Sciences, 2013

BACKGROUND: Poly methyl methacrylate is one of the most widely accepted biomaterial in prosthetic... more BACKGROUND: Poly methyl methacrylate is one of the most widely accepted biomaterial in prosthetic dentistry due to its biocompatibility, insoluble and non corrosive characteristics, good transparency, good color stability over the years, easy to process and repair, dimensionally stable, comparatively low density (1.19g/cm3), and low heat distortion temperature. However these materials are far from being ideal because of their inferior mechanical and thermal properties. So the present study is to achieve the desirable impact strength of poly methyl methacrylate material, by reinforcing it with E glass fibers. AIM: Determination of impact strength of PMMA denture base by varying the weight percentage of glass fiber, by varying the aspect ratio of glass fiber. Determination of the optimum property of the PMMA denture base using the correct weight percentage and aspect ratio. MATERIALS AND METHODS: Specimens prepared using a standard cylindrical mold of 8mm diameter and 45mm length. A t...

Journal of Dental Materials and Techniques, 2020

Introduction: Glass ionomer cement (GIC) is a dental restorative material that is prone to solubi... more Introduction: Glass ionomer cement (GIC) is a dental restorative material that is prone to solubility and degradation. GIC could degrade in presence of water and desiccation due to environmental factors during setting process and eventually might lead to the failure of the restoration. Cigarette smoking brings a complex chemical mixture to oral cavity that can inhibit polymerization and promote the solubility of this cement. Therefore, the aim of this study was to evaluate the effect of cigarette smoking on solubility and disintegration of resin-modified glass ionomer cement (RMGIC). Methods: RMGIC used for preparation of control group (n=54) with same number of samples in test group (n=54). The test groups were exposed to cigarette smoking. Samples divided in groups of 6 to immerse in three different mediums (water, normal saline and qahwa, the Arabic tea) for the immersion periods of 1h, 24h and 7days. Differences in weight of each sample were recorded before and after immersion. ...

Journal of Evolution of medical and Dental Sciences, 2021

BACKGROUND Dimensional change and porosity in the polymethylmethacrylate based prosthesis affects... more BACKGROUND Dimensional change and porosity in the polymethylmethacrylate based prosthesis affects its clinical performance. Hence, the present study aimed to evaluate the porosity and water sorption present in the modified polymethyl methacrylate polymer composite. METHODS Control group without fibre reinforcement and test groups with fibre reinforcement were prepared for the study. Three different fibres such as boron free-E glass fibre, untreated and plasma-treated polypropylene fibres in varying weight percentage and aspect ratio were considered for reinforcement. The porosity of the fractured surface was observed through a scanning electron microscope (scanning electron microscope) and sorption measured based on international standards organization (ISO) 1567:1999. RESULTS Control group exhibited porous structures, whereas all fibre-reinforced groups did not exhibit porous structure at the fracture surface. There was a significant difference in the sorption rate between control ...

International journal of scientific research, 2018

In search of developing a self disinfecting alginate impression material, the present study condu... more In search of developing a self disinfecting alginate impression material, the present study conducted to evaluate the mixing characteristics of commercially available alginate dental impression material with three distinct disinfectant solutions. Four commercially available alginate powders were selected as A: Tropicalgin, B: Cavex CA 37, C: KROMOPAN, D: United Alginate. Disinfectant solutions also were selected as I: Isopropyl alcohol 70%, II: Hydrogen peroxide- 6%, III: Povidone- Iodine- 10%. The mixing procedure was standardized by choosing a consistent manufacturer recommended powder to liquid ratio for all type of test materials. From the result obtained, it is observed that consistency suitable for impression making was obtained only with 6% hydrogen peroxide and 10 % povidone iodine for all types of alginate powders. A sandy like consistency, which is not suitable for dental impression, was obtained with isopropyl alcohol for all four types of alginates.

Dental implants considered as an important dental treatment modality as it substitutes missing or... more Dental implants considered as an important dental treatment modality as it substitutes missing or damaged teeth with maximum life like acceptability. It consists of various parts such as crown portion, abutment and the root portion. Several medical devices are assembled together to achieve the functionality of the dental implants. It is available in several geometry, lengths and diameter. Different implant systems available in the market and are focused mainly on the factors such as implant/abutment interface, body shape and implant to bone interface. The success rate of implant is greatly depended on the osseointegration and implant bone interface stability. In addition to these factors, the safety concerns and compatibility aspects are significant in deciding the suitability of any implant system. Therefore, the current review seeks the suitability of dental tech implant system. A range of products are available from this implant system to fulfil the need of professionals in diver...

Paripex Indian Journal Of Research, 2018

BACKGROUND: The changes in lipid profile have long been associated with cancer. Recent advances i... more BACKGROUND: The changes in lipid profile have long been associated with cancer. Recent advances in the field of biologic science have sparked new interest in the areas of identifying cancer biomarkers in the bodily fluids. AIMS: The present study evaluated alterations in plasma lipid profile in patients with premalignant and malignant lesions of Head & Neck region. MATERIAL AND METHODS: This clinical study was conducted in our institution for 2 years.Total of 100 patients, 50 with PM & 50 with M lesions were randomly selected from outpatient visiting the Department of ENT, Head & Neck Oncology, Oral Medicine & Radiology. Plasma lipids: (i) Total cholesterol (ii)LDL cholesterol (iii)HDL cholesterol (iv)VLDL cholesterol and (v)Triglycerides analysed. STATISTICAL ANALYSIS: Student's t-test was performed to compare mean values of the parameters. RESULTS: Serum lipids were in normal range in PM and M group and no statistical significant difference between P values when compared.

Journal of Hydrology: Regional Studies, 2021

Abstract Study region Kerala, Southern Western Ghats, India Study focus A better understanding of... more Abstract Study region Kerala, Southern Western Ghats, India Study focus A better understanding of the trends in rainfall, its distribution and characteristics is of paramount importance, for effective management of water resources, especially, in regions with marked spatiotemporal variability in rainfall. The present study examines the spatiotemporal changes in rainfall pattern and its effect on the hydrological regime of a tropical monsoon dominated region in Western Ghats, India. New hydrological insights for the region Weakening of monsoon rains was observed in the region, with decreasing trend in monsoon season, increasing trend in pre-monsoon season as well as an accelerated change in rainfall pattern during the recent decades. Monsoon droughts are becoming more prominent as evidenced the increasing trend in total number of dry and prolonged dry spells. Seasonality Index of rainfall consistently showed decreasing trend indicating that the rainfall distribution is becoming more symmetric over the years. No significant relationship was observed between ENSO events and rainfall characteristics indicating that ENSO episodes do not considerably affect the variability of rainfall in the region. Effect of changes in rainfall characteristics have a strong bearing on the hydrological regime of the region, which was evident in the declining trend of streamflow and groundwater level. The study calls for a revised plan for water management, adaptive cropping pattern and reservoir operations in the state of Kerala.

Journal of International Oral Health, 2020

Aim: Biofilm bacteria show coordinated behavior with heterogeneous bacterial communities and comp... more Aim: Biofilm bacteria show coordinated behavior with heterogeneous bacterial communities and complex three-dimensional structures. Biofilm formation on dental implants occurs in a manner similar to that of a natural tooth. Bacterial adhesion occurs after pellicle formation. Therefore, to reduce bacterial adhesion, the biomaterial surface can be modified, thereby lowering the scope of biofilm formation. This review aimed to understand the mechanism of biofilm formation; the most common microorganisms associated with a biofilm, nature of the bonds to the host tissue, and the methods to overcome biofilm formation and associated infectious diseases from dental materials and implants. Materials and Methods: A comprehensive literature search was conducted on published articles using internet search databases such as PubMed, EBSCO, Cochrane library, Embase, HMIC, Web of Science, Google Scholar, and Directory of Open Access using keywords such as biofilm, quorum sensing, implant-related biofilm formation, and biofilm control. Results: A total of 121 articles published from March 2007 to May 2020 were screened during the review process, of which only 33 articles were selected for this study. Surface roughness is directly proportional to bacterial aggregation. PEEK is a modified functional peptide nanoparticle-coated biomaterial that manifests antibacterial activity against gram-negative Escherichia coli and gram-positive Staphylococcus aureus. Conclusions: New strategies are to be followed to control biofilm-mediated implant infections. Clinicians should extensively adopt newer techniques to deal with biofilm-mediated therapeutic challenges.

Journal of International Oral Health, 2020

Aim: Dental cements are used extensively in various dental restorative procedures and are suscept... more Aim: Dental cements are used extensively in various dental restorative procedures and are susceptible to bacterial adhesion and biofilm formation. Streptococcus mutans are the causative organism for dental caries and associated problems. This study aimed to develop an antibacterial activity for four types of dental cements by incorporating the leaves, fruit, and bark extract of the Ziziphus spina-christi, a well-known medicinal plant found mainly in the Middle East region. Materials and Methods: This in vitro study was conducted by using a systematic sampling method. A total of 312 samples were prepared for both control and test groups for this study. Negative control samples were prepared using four dental cements alone (n = 24) and positive control (n = 72) using gentamicin incorporated into these four different types of dental cements. The collected plant materials were extracted using Soxhlet apparatus with methanol as a solvent. Obtained extracts were incorporated in various percentages (5, 10, and 15 wt%) into dental cements to prepare test samples (n = 216). Antibacterial efficacy of the extracts selected was measured by using well diffusion method. The antibacterial activity of all the prepared samples was measured using the disk-diffusion method. The null hypothesis was that the extract incorporation did not inhibit bacterial growth on the selected dental cements. Results were analyzed statistically using one-way analysis of variance (ANOVA) followed by Tukey–Kramer multiple comparison tests using GraphPad InStat software. Level of significance was set at P = 0.05. Results: All extracts showed antibacterial activity for gentamicin. Zone produced was superior for leaf extract compared to stem and fruit extract (P < 0.001). Negative control samples showed bacterial growth. The test samples did not support bacterial growth. However, the inhibition zone was absent. Conclusion: Ziziphus spina plant extracts can inhibit the growth on S. mutans. The efficacy of each extracts against the bacteria was varied.

International Journal of River Basin Management, 2020

The changes in land use and regional climate together with human interventions affect the hydrolo... more The changes in land use and regional climate together with human interventions affect the hydrological processes resulting in spatial and temporal alterations of surface and subsurface flow processes. Both climate and land surface change have adverse implications on the natural hydrologic system in terms of variation in the runoff regime, surface storage, evapotranspiration, subsurface flow and infiltration thereby affecting the hydrology of the river basin as a whole. Even though several studies worldwide have attempted to address the influence of climate change, land use change and human activities on the hydrology of river basins, either as a whole or limited to a few components of the hydrological cycle, limited attention has been given to study the hydrological changes in the river basins of arid and semiarid tropics, which are essentially fed by precipitation. The objective of the study is to analyze the changes in hydrological characteristics of the Cauvery river basin, a semiarid river basin in South India. The changes in the hydrology of the Cauvery river basin are studied by analyzing the trends in hydro-meteorological parameters using Mann-Kendall trend tests and Sen's estimator of slope. Results showed that the changes in volume of rainfall and the number of rainy days significantly affect the overall hydrological regime of the river basin. Analysis of annual and seasonal rainfall over the Cauvery river basin, showed a decreasing trend in the middle Cauvery basin. Declining trend in the number of rainfall events was also observed in the middle Cauvery region. Effect of decreasing trend in volume of rainfall and number of rainy days is evident from the decreasing trends in the streamflow of main channel and tributaries of the Cauvery river. The regions of increase in evapotranspiration showed a significant correlation with the regions which exhibited a decline in groundwater level.

Head and Neck Cancer Research, 2018

Background: Schwannomas are benign and slow growing tumors that arise from the Schwann cells whic... more Background: Schwannomas are benign and slow growing tumors that arise from the Schwann cells which ensheath the axons of peripheral nerve, cranial nerve and autonomic nervous system. A schwannoma of facial nerve may originate from extra or intra cranial segments of the nerve. Most of the facial nerve schwannomas originate from intra-tympanic region. In decreasing order of their frequency, schwannomas were found along the tympanic, mastoid (vertical), labrynthine and meatal segments of the facial nerve. It is an extremely rare entity as malignant degeneration of schwannomas is not frequent. A high level of clinical suspicion with detailed neuro-otological and radiological studies play important role in preoperative diagnosis of schwannomas. Case presentation: We reported a case of 35-year-old male with progressive right sided facial asymmetry, sudden onset hearing loss and non-pulsatile tinnitus in right ear. The patient's presentation and diagnostic examinations helped us to reach a provisional diagnosis though final diagnosis was done on the basis of histopathological examination of the excised tumor which was suggestive of facial nerve schwannoma. Conclusion: The rare and inconsistent clinical presentation and radiological pattern of facial schwannoma often leads to a delayed and indefinite diagnosis. The critical step in management of diverse lesion is diagnosis for the management of facial schwannoma. This report is about a challenging case of facial nerve schwannoma in intra-tympanic region which was diagnosed and managed in our institution.

The Journal of Indian Prosthodontic Society, 2018

The present study aimed to evaluate flexural strength of hydrogen plasma-treated polypropylene fi... more The present study aimed to evaluate flexural strength of hydrogen plasma-treated polypropylene fibers-reinforced polymethyl methacrylate (PMMA) polymer composite. Materials and Methods: One control group with no fiber reinforcement and 9 polymer composite test groups with varying fiber weight percentage (2.5, 5, and 10 Wt%) and aspect ratio (3/220, 6/220, and 12 mm/220 µm) were prepared. Flexural strength was measured using Instron. Results: All hydrogen plasma-treated polypropylene fiber-reinforced test groups obtained significantly higher flexural strength characteristics. Among the test groups, 6 mm long fibers reinforced in 10 Wt% showed superior flexural strength. Conclusion: Hydrogen plasma treatment on polypropylene fiber has a significant role in enhancing the adhesion between PMMA polymer matrix and the polypropylene fibers and thereby the flexural strength.

Journal of Drug Delivery and Therapeutics, 2017

Nanosuspensions are colloidal dispersions and biphasic system consisting of drug particles disper... more Nanosuspensions are colloidal dispersions and biphasic system consisting of drug particles dispersed in an aqueous vehicle in which the diameter of the suspended particle is less than 1μm in size. Many drugs including antibiotics are having poor solubility. Nanosuspensions have proven to be a better alternative over other approaches currently available for improving bioavailability of such drugs with low solubility. This review describes the methods of pharmaceutical nanosuspension of antibiotic formulations and pharmaceutical applications in drug delivery.

Impact Strength of E Glass Reinforced Pmma, Jul 8, 2013

International Journal of Experimental Dental Science, 2014

Background Poly (methyl 2-methylpropenoate) (PMMA) is one of the most widely accepted biomaterial... more Background Poly (methyl 2-methylpropenoate) (PMMA) is one of the most widely accepted biomaterials due to its acceptable advantageous but the limitations associated with these materials make them far from being ideal. So, the present study is to achieve desirable flexural strength by reinforcing PMMA with E-glass fiber. Aim Determination of flexural strength of PMMA by varying the weight percentage of glass fiber (2.5 wt%, 5 wt%, 10 wt%), and by varying the aspect ratio (3 mm/20 µm, 6 mm/20 µm, 12 mm/20 µm) of glass fiber. Materials and methods Specimens prepared using a standard rectangular mold of 62 mm length, 10 mm breadth and 2.5 mm thickness. A total of 60 samples prepared (6 samples in each group) polymer—monomer ratio 2.4:1 by weight used to prepare samples. Flexural strength is tested using universal testing machine Instron. The microstructural analysis using scanning electron microscopy performed in order to understand the fiber matrix bonding. Detailed statistical analysi...

Trends in biomaterials & artificial organs, 2020

Diagnostic nasal endoscopy and computed tomography of para nasal sinuses play an important role i... more Diagnostic nasal endoscopy and computed tomography of para nasal sinuses play an important role in the diagnosis and treatment of Chronic Rhinosinusitis (CRS). This study explains the importance of both, individually and together.The application of these diagnostic modalities is patient and disease dependent. Rather than competing with each other, they go hand in hand!

Poly methyl methacrylate (PMMA) is one of the most widely accepted biomaterial in prosthetic dent... more Poly methyl methacrylate (PMMA) is one of the most widely accepted biomaterial in prosthetic dentistry due to its acceptable advantages. However the conventional PMMA used are far from being ideal because of their inferior mechanical properties. So the present study is to determine the Vickers Hardness and specific wear rate of the silane treated E glass fiber reinforced PMMA. Vickers Hardness number and specific wear rate of PMMA denture base can be determined by varying the weight percentage and aspect ratio of glass fiber. To measure the Vickers hardness, specimens prepared using a standard rectangular mold of 62mm length, 10 mm breadth and 2.5 mm thickness. Vickers Hardness number measured using Vickers hardness test apparatus having square based diamond pyramid as indenter. For wear analysis, specimens prepared using a standard cylindrical mold of 8mm diameter and 25mm length. Specific wear rate measured after measuring the weight loss in the pin on disc method by Wear and Fric...

Journal of Evolution of medical and Dental Sciences, 2013

BACKGROUND: Poly methyl methacrylate is one of the most widely accepted biomaterial in prosthetic... more BACKGROUND: Poly methyl methacrylate is one of the most widely accepted biomaterial in prosthetic dentistry due to its biocompatibility, insoluble and non corrosive characteristics, good transparency, good color stability over the years, easy to process and repair, dimensionally stable, comparatively low density (1.19g/cm3), and low heat distortion temperature. However these materials are far from being ideal because of their inferior mechanical and thermal properties. So the present study is to achieve the desirable impact strength of poly methyl methacrylate material, by reinforcing it with E glass fibers. AIM: Determination of impact strength of PMMA denture base by varying the weight percentage of glass fiber, by varying the aspect ratio of glass fiber. Determination of the optimum property of the PMMA denture base using the correct weight percentage and aspect ratio. MATERIALS AND METHODS: Specimens prepared using a standard cylindrical mold of 8mm diameter and 45mm length. A t...

Journal of Dental Materials and Techniques, 2020

Introduction: Glass ionomer cement (GIC) is a dental restorative material that is prone to solubi... more Introduction: Glass ionomer cement (GIC) is a dental restorative material that is prone to solubility and degradation. GIC could degrade in presence of water and desiccation due to environmental factors during setting process and eventually might lead to the failure of the restoration. Cigarette smoking brings a complex chemical mixture to oral cavity that can inhibit polymerization and promote the solubility of this cement. Therefore, the aim of this study was to evaluate the effect of cigarette smoking on solubility and disintegration of resin-modified glass ionomer cement (RMGIC). Methods: RMGIC used for preparation of control group (n=54) with same number of samples in test group (n=54). The test groups were exposed to cigarette smoking. Samples divided in groups of 6 to immerse in three different mediums (water, normal saline and qahwa, the Arabic tea) for the immersion periods of 1h, 24h and 7days. Differences in weight of each sample were recorded before and after immersion. ...

Journal of Evolution of medical and Dental Sciences, 2021

BACKGROUND Dimensional change and porosity in the polymethylmethacrylate based prosthesis affects... more BACKGROUND Dimensional change and porosity in the polymethylmethacrylate based prosthesis affects its clinical performance. Hence, the present study aimed to evaluate the porosity and water sorption present in the modified polymethyl methacrylate polymer composite. METHODS Control group without fibre reinforcement and test groups with fibre reinforcement were prepared for the study. Three different fibres such as boron free-E glass fibre, untreated and plasma-treated polypropylene fibres in varying weight percentage and aspect ratio were considered for reinforcement. The porosity of the fractured surface was observed through a scanning electron microscope (scanning electron microscope) and sorption measured based on international standards organization (ISO) 1567:1999. RESULTS Control group exhibited porous structures, whereas all fibre-reinforced groups did not exhibit porous structure at the fracture surface. There was a significant difference in the sorption rate between control ...

International journal of scientific research, 2018

In search of developing a self disinfecting alginate impression material, the present study condu... more In search of developing a self disinfecting alginate impression material, the present study conducted to evaluate the mixing characteristics of commercially available alginate dental impression material with three distinct disinfectant solutions. Four commercially available alginate powders were selected as A: Tropicalgin, B: Cavex CA 37, C: KROMOPAN, D: United Alginate. Disinfectant solutions also were selected as I: Isopropyl alcohol 70%, II: Hydrogen peroxide- 6%, III: Povidone- Iodine- 10%. The mixing procedure was standardized by choosing a consistent manufacturer recommended powder to liquid ratio for all type of test materials. From the result obtained, it is observed that consistency suitable for impression making was obtained only with 6% hydrogen peroxide and 10 % povidone iodine for all types of alginate powders. A sandy like consistency, which is not suitable for dental impression, was obtained with isopropyl alcohol for all four types of alginates.

Dental implants considered as an important dental treatment modality as it substitutes missing or... more Dental implants considered as an important dental treatment modality as it substitutes missing or damaged teeth with maximum life like acceptability. It consists of various parts such as crown portion, abutment and the root portion. Several medical devices are assembled together to achieve the functionality of the dental implants. It is available in several geometry, lengths and diameter. Different implant systems available in the market and are focused mainly on the factors such as implant/abutment interface, body shape and implant to bone interface. The success rate of implant is greatly depended on the osseointegration and implant bone interface stability. In addition to these factors, the safety concerns and compatibility aspects are significant in deciding the suitability of any implant system. Therefore, the current review seeks the suitability of dental tech implant system. A range of products are available from this implant system to fulfil the need of professionals in diver...

Paripex Indian Journal Of Research, 2018

BACKGROUND: The changes in lipid profile have long been associated with cancer. Recent advances i... more BACKGROUND: The changes in lipid profile have long been associated with cancer. Recent advances in the field of biologic science have sparked new interest in the areas of identifying cancer biomarkers in the bodily fluids. AIMS: The present study evaluated alterations in plasma lipid profile in patients with premalignant and malignant lesions of Head & Neck region. MATERIAL AND METHODS: This clinical study was conducted in our institution for 2 years.Total of 100 patients, 50 with PM & 50 with M lesions were randomly selected from outpatient visiting the Department of ENT, Head & Neck Oncology, Oral Medicine & Radiology. Plasma lipids: (i) Total cholesterol (ii)LDL cholesterol (iii)HDL cholesterol (iv)VLDL cholesterol and (v)Triglycerides analysed. STATISTICAL ANALYSIS: Student's t-test was performed to compare mean values of the parameters. RESULTS: Serum lipids were in normal range in PM and M group and no statistical significant difference between P values when compared.

Journal of Hydrology: Regional Studies, 2021

Abstract Study region Kerala, Southern Western Ghats, India Study focus A better understanding of... more Abstract Study region Kerala, Southern Western Ghats, India Study focus A better understanding of the trends in rainfall, its distribution and characteristics is of paramount importance, for effective management of water resources, especially, in regions with marked spatiotemporal variability in rainfall. The present study examines the spatiotemporal changes in rainfall pattern and its effect on the hydrological regime of a tropical monsoon dominated region in Western Ghats, India. New hydrological insights for the region Weakening of monsoon rains was observed in the region, with decreasing trend in monsoon season, increasing trend in pre-monsoon season as well as an accelerated change in rainfall pattern during the recent decades. Monsoon droughts are becoming more prominent as evidenced the increasing trend in total number of dry and prolonged dry spells. Seasonality Index of rainfall consistently showed decreasing trend indicating that the rainfall distribution is becoming more symmetric over the years. No significant relationship was observed between ENSO events and rainfall characteristics indicating that ENSO episodes do not considerably affect the variability of rainfall in the region. Effect of changes in rainfall characteristics have a strong bearing on the hydrological regime of the region, which was evident in the declining trend of streamflow and groundwater level. The study calls for a revised plan for water management, adaptive cropping pattern and reservoir operations in the state of Kerala.

Journal of International Oral Health, 2020

Aim: Biofilm bacteria show coordinated behavior with heterogeneous bacterial communities and comp... more Aim: Biofilm bacteria show coordinated behavior with heterogeneous bacterial communities and complex three-dimensional structures. Biofilm formation on dental implants occurs in a manner similar to that of a natural tooth. Bacterial adhesion occurs after pellicle formation. Therefore, to reduce bacterial adhesion, the biomaterial surface can be modified, thereby lowering the scope of biofilm formation. This review aimed to understand the mechanism of biofilm formation; the most common microorganisms associated with a biofilm, nature of the bonds to the host tissue, and the methods to overcome biofilm formation and associated infectious diseases from dental materials and implants. Materials and Methods: A comprehensive literature search was conducted on published articles using internet search databases such as PubMed, EBSCO, Cochrane library, Embase, HMIC, Web of Science, Google Scholar, and Directory of Open Access using keywords such as biofilm, quorum sensing, implant-related biofilm formation, and biofilm control. Results: A total of 121 articles published from March 2007 to May 2020 were screened during the review process, of which only 33 articles were selected for this study. Surface roughness is directly proportional to bacterial aggregation. PEEK is a modified functional peptide nanoparticle-coated biomaterial that manifests antibacterial activity against gram-negative Escherichia coli and gram-positive Staphylococcus aureus. Conclusions: New strategies are to be followed to control biofilm-mediated implant infections. Clinicians should extensively adopt newer techniques to deal with biofilm-mediated therapeutic challenges.

Journal of International Oral Health, 2020

Aim: Dental cements are used extensively in various dental restorative procedures and are suscept... more Aim: Dental cements are used extensively in various dental restorative procedures and are susceptible to bacterial adhesion and biofilm formation. Streptococcus mutans are the causative organism for dental caries and associated problems. This study aimed to develop an antibacterial activity for four types of dental cements by incorporating the leaves, fruit, and bark extract of the Ziziphus spina-christi, a well-known medicinal plant found mainly in the Middle East region. Materials and Methods: This in vitro study was conducted by using a systematic sampling method. A total of 312 samples were prepared for both control and test groups for this study. Negative control samples were prepared using four dental cements alone (n = 24) and positive control (n = 72) using gentamicin incorporated into these four different types of dental cements. The collected plant materials were extracted using Soxhlet apparatus with methanol as a solvent. Obtained extracts were incorporated in various percentages (5, 10, and 15 wt%) into dental cements to prepare test samples (n = 216). Antibacterial efficacy of the extracts selected was measured by using well diffusion method. The antibacterial activity of all the prepared samples was measured using the disk-diffusion method. The null hypothesis was that the extract incorporation did not inhibit bacterial growth on the selected dental cements. Results were analyzed statistically using one-way analysis of variance (ANOVA) followed by Tukey–Kramer multiple comparison tests using GraphPad InStat software. Level of significance was set at P = 0.05. Results: All extracts showed antibacterial activity for gentamicin. Zone produced was superior for leaf extract compared to stem and fruit extract (P < 0.001). Negative control samples showed bacterial growth. The test samples did not support bacterial growth. However, the inhibition zone was absent. Conclusion: Ziziphus spina plant extracts can inhibit the growth on S. mutans. The efficacy of each extracts against the bacteria was varied.

International Journal of River Basin Management, 2020

The changes in land use and regional climate together with human interventions affect the hydrolo... more The changes in land use and regional climate together with human interventions affect the hydrological processes resulting in spatial and temporal alterations of surface and subsurface flow processes. Both climate and land surface change have adverse implications on the natural hydrologic system in terms of variation in the runoff regime, surface storage, evapotranspiration, subsurface flow and infiltration thereby affecting the hydrology of the river basin as a whole. Even though several studies worldwide have attempted to address the influence of climate change, land use change and human activities on the hydrology of river basins, either as a whole or limited to a few components of the hydrological cycle, limited attention has been given to study the hydrological changes in the river basins of arid and semiarid tropics, which are essentially fed by precipitation. The objective of the study is to analyze the changes in hydrological characteristics of the Cauvery river basin, a semiarid river basin in South India. The changes in the hydrology of the Cauvery river basin are studied by analyzing the trends in hydro-meteorological parameters using Mann-Kendall trend tests and Sen's estimator of slope. Results showed that the changes in volume of rainfall and the number of rainy days significantly affect the overall hydrological regime of the river basin. Analysis of annual and seasonal rainfall over the Cauvery river basin, showed a decreasing trend in the middle Cauvery basin. Declining trend in the number of rainfall events was also observed in the middle Cauvery region. Effect of decreasing trend in volume of rainfall and number of rainy days is evident from the decreasing trends in the streamflow of main channel and tributaries of the Cauvery river. The regions of increase in evapotranspiration showed a significant correlation with the regions which exhibited a decline in groundwater level.

Head and Neck Cancer Research, 2018

Background: Schwannomas are benign and slow growing tumors that arise from the Schwann cells whic... more Background: Schwannomas are benign and slow growing tumors that arise from the Schwann cells which ensheath the axons of peripheral nerve, cranial nerve and autonomic nervous system. A schwannoma of facial nerve may originate from extra or intra cranial segments of the nerve. Most of the facial nerve schwannomas originate from intra-tympanic region. In decreasing order of their frequency, schwannomas were found along the tympanic, mastoid (vertical), labrynthine and meatal segments of the facial nerve. It is an extremely rare entity as malignant degeneration of schwannomas is not frequent. A high level of clinical suspicion with detailed neuro-otological and radiological studies play important role in preoperative diagnosis of schwannomas. Case presentation: We reported a case of 35-year-old male with progressive right sided facial asymmetry, sudden onset hearing loss and non-pulsatile tinnitus in right ear. The patient's presentation and diagnostic examinations helped us to reach a provisional diagnosis though final diagnosis was done on the basis of histopathological examination of the excised tumor which was suggestive of facial nerve schwannoma. Conclusion: The rare and inconsistent clinical presentation and radiological pattern of facial schwannoma often leads to a delayed and indefinite diagnosis. The critical step in management of diverse lesion is diagnosis for the management of facial schwannoma. This report is about a challenging case of facial nerve schwannoma in intra-tympanic region which was diagnosed and managed in our institution.

The Journal of Indian Prosthodontic Society, 2018

The present study aimed to evaluate flexural strength of hydrogen plasma-treated polypropylene fi... more The present study aimed to evaluate flexural strength of hydrogen plasma-treated polypropylene fibers-reinforced polymethyl methacrylate (PMMA) polymer composite. Materials and Methods: One control group with no fiber reinforcement and 9 polymer composite test groups with varying fiber weight percentage (2.5, 5, and 10 Wt%) and aspect ratio (3/220, 6/220, and 12 mm/220 µm) were prepared. Flexural strength was measured using Instron. Results: All hydrogen plasma-treated polypropylene fiber-reinforced test groups obtained significantly higher flexural strength characteristics. Among the test groups, 6 mm long fibers reinforced in 10 Wt% showed superior flexural strength. Conclusion: Hydrogen plasma treatment on polypropylene fiber has a significant role in enhancing the adhesion between PMMA polymer matrix and the polypropylene fibers and thereby the flexural strength.

Journal of Drug Delivery and Therapeutics, 2017

Nanosuspensions are colloidal dispersions and biphasic system consisting of drug particles disper... more Nanosuspensions are colloidal dispersions and biphasic system consisting of drug particles dispersed in an aqueous vehicle in which the diameter of the suspended particle is less than 1μm in size. Many drugs including antibiotics are having poor solubility. Nanosuspensions have proven to be a better alternative over other approaches currently available for improving bioavailability of such drugs with low solubility. This review describes the methods of pharmaceutical nanosuspension of antibiotic formulations and pharmaceutical applications in drug delivery.

Impact Strength of E Glass Reinforced Pmma, Jul 8, 2013

International Journal of Experimental Dental Science, 2014

Background Poly (methyl 2-methylpropenoate) (PMMA) is one of the most widely accepted biomaterial... more Background Poly (methyl 2-methylpropenoate) (PMMA) is one of the most widely accepted biomaterials due to its acceptable advantageous but the limitations associated with these materials make them far from being ideal. So, the present study is to achieve desirable flexural strength by reinforcing PMMA with E-glass fiber. Aim Determination of flexural strength of PMMA by varying the weight percentage of glass fiber (2.5 wt%, 5 wt%, 10 wt%), and by varying the aspect ratio (3 mm/20 µm, 6 mm/20 µm, 12 mm/20 µm) of glass fiber. Materials and methods Specimens prepared using a standard rectangular mold of 62 mm length, 10 mm breadth and 2.5 mm thickness. A total of 60 samples prepared (6 samples in each group) polymer—monomer ratio 2.4:1 by weight used to prepare samples. Flexural strength is tested using universal testing machine Instron. The microstructural analysis using scanning electron microscopy performed in order to understand the fiber matrix bonding. Detailed statistical analysi...