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Return to work after spinal cord injury in Malaysia

Ramakrishnan K, Chung TY, Hasnan N, Abdullah SJ

Spinal Cord, 2011 Jul;49(7):812-6.
PMID: 21221119 DOI: 10.1038/sc.2010.186

STUDY DESIGN: Cross-sectional survey.
OBJECTIVES: To determine the employment outcomes of persons with spinal cord injury (SCI) and to investigate the impact of various demographic, injury-related and work-related variables on these outcomes.
SETTING: People living with SCI in Malaysia who are members of a disability support organization.
METHODS: A total of 84 members of the Malaysian Spinal Injury Association, who have had traumatic SCI for at least 2 years and were between 15 and 64 years of age at the time of study, were interviewed through phone using a questionnaire to identify the association between demographic, injury-related and work-related variables and employment outcomes.
RESULTS: The return to work rate in this study was 57.1% (employed at the time of study). The overall employment rate after SCI was 76.2% (worked at some point after injury). Those who were younger at time of injury (<20 years of age), able to drive a modified vehicle, independent in personal care and mobility were positively related to being employed. On the other hand, being hospitalized in the preceding 1 year and receiving financial incentives were negatively related to employment.
CONCLUSION: Functional independence, especially ability to drive, was strongly associated with return to work and should be one of the priority goals of comprehensive rehabilitation of persons with SCI. The negative impact of recent hospitalization as well as financial compensation needs to be probed further.
Return to work after spinal cord injury: factors related to time to first job

Ramakrishnan K, Mazlan M, Julia PE, Abdul Latif L

Spinal Cord, 2011 Aug;49(8):924-7.
PMID: 21383761 DOI: 10.1038/sc.2011.16

STUDY DESIGN: Cross-sectional survey.
OBJECTIVES: To investigate factors related to length of time between spinal cord injury (SCI) onset and start of first post-injury employment.
SETTING: Persons living with SCI in the community who are members of a disability support organization.
METHODS: Participants were randomly selected from the membership list of a non-governmental voluntary organization. They met the following four criteria: traumatic SCI, minimum of 15 years of age at the time of survey, a minimum of 2 years after SCI and had been employed for some time since SCI. The main outcome measure was time (in years) from injury onset to beginning first post-injury job.
RESULTS: Participants averaged 4.9 years (s.d. 5.1) from the time of SCI to their first post-injury job, with a range of 3 months to 20 years. Fifty percent of the participants who eventually returned to work had done so by 4 years. Return to pre-injury employer and employment were associated with early return, whereas having less years in education and being older at the time of injury were associated with longer time to return to work.
CONCLUSION: Rehabilitation team need to consider return to employment as a realistic goal even many years after SCI. Perhaps a focus on returning more people to their pre-injury employer and employment with added focus and input from rehabilitation team for those with lower education status and older age at time of injury might expedite the process of reintegration.
Immigrant Health Study. 5. Faecal pathogens in foreign workers. [Abstract]

Suresh K, Rajah S, Khairul Anuar A, Anuar Zaini MZ, Saminathan R, Ramakrishnan S

JUMMEC, 1998;3:62-63.

One hundred seventy three stool samples were obtained from workers from Indonesia, Bangladesh, Myanmar, Pakistan and others. The stool samples were examined for Ascaris, Trichuris, Hookworm, Schistosomes, trematodes and cestodes. The protozaon parasites included Bnlantidiirrir coli, Blastocystis honlinis, Cyclospora cryptosporidium, Microsporidiirin, Entamoeeba histolytica, Giardia lamblia, lodamoeba butschilli. Of these 21.9%, 17% and 1% of the population studied had hookworm, Trichuris trichiura and Ascaris lumbricoides infections respectively. There was only one Indonesian reported to have Hymenolepis nana infections. The most common protozoan seen in the faecal sample is Blastocystis hominis (36%) followed by Giardia lamblia (4%). Most of the stools positive with these faecal pathogens were semisolid especially the ones positive for the protozoan. We have also shown Blastocystis from the Indonesian workers show very small forms almost 3-5 in size compared to the normal size of 10-15 pm in the other nationalities. These forms show a distinct growth profile in cultures and appears to be more resistant to temperature changes than Blastocystis seen in the other two nationalities. The high incidence of Hookworm and Trichuris infections is suggestive that if these workers are left unheated their productivity will be hampered by other possible serious complications such as anaemia, weight loss, abdominal pain with diarrhoea1 stools and nausea. There are increasing reports that Blastocystis hominis is pathogenic. Flatulence, abdominal discomfort and the increase in the frequency of the passing watery stool has been noted in patients infected with the parasite. Since most of the workers are generally housed in crowded rooms it is highly likely that this will facilitate transmission through the faecal-oral route of both Giardia and Blastocystis possibly increasing the incidences of these infections among workers.
Fulltext Nurse's perception and compliance on identification, situation, background, assessment and recommendation (ISBAR) tools for handoff communication in tertiary hospital, Dammam

Chiew, Lisa, Sazelin Abu Bakar, Ramakrishnan, Selvi, Patricia, Lo Cheng Cheng, Karunagaran, Yugeswary, Zuraidah Bunyaman

Malaysian Journal of Medical Research, 2019;3(4):26-32.
MyJurnal

Background: The identification, situation, background, assessment and recommendation (ISBAR) is a handoff tool that plays an important role in transferring responsibility and accountability in patient care from outgoing shifts to incoming shifts. Many researchers believe that handoff is very important among nurses. Nurses had the responsibility to ensure patients' correct information which were shared among themselves during handoff. It also delivers the best patient care by improving the transfer of clinical information globally and systematically. Purpose: The aim of the study is to determine nurse's perception and compliance on ISBAR tool for handoff communication in tertiary hospital, Dammam. Method: A cross-sectional descriptive study was conducted in oncology unit at tertiary hospital, Dammam, Saudi Arabia. Total sample size was 70. Questionnaire was the instrument tool in the study to measure nurse's perception and compliance on ISBAR tools. Result: The overall perception mean score achieved was 38.64±1.455 and compliance score was 7.73±0.588. This showed nurses had good perception and compliance on ISBAR tools and none of them had poor perception and compliance regarding the same. There was statistically significant relationship (P=0.000) between perception and compliance on ISBAR tools. Conclusion: ISBAR is reliable and effective handoff communication tools to promote patient safety. However, continuous education should be maintained to ensure all nurses competent in ISBAR tool. Further studies will be necessary to evaluate relationship between nurses' perception and compliance on ISBAR tool.
Fulltext Recent advances in salivary proteomics, genomics and transcriptomics: a reliable tool in periodontal diagnosis – a review

P, Rajapriya, P, Saravanan, NK, Burnice, KC, Priyanka, S, Shalini, Ramakrishnan

Ann Dent, 2014;21(2):8-16.
MyJurnal

This review intends to provide a highlight on the potential application of salivary proteomics in
periodontal diagnosis and attempts to throw light on the emerging salivary diagnostic tools for periodontal disease detection. Background: Clinical parameters for detection of periodontitis such as probing depth, attachment level, bleeding on probing, plaque index, and radiographic assessment of alveolar bone loss provide information on the severity of periodontitis, but they do not measure disease activity. Ideally, development and application of rapid and simple diagnostic tests based on host salivary or immune factors may facilitate early detection of patients at risk for periodontal diseases, allow appropriate intervention, decrease the need for more aggressive treatment and improve the response to periodontal therapy. Results: Studies have shown that saliva could be used as a diagnostic fluid as it is one of the inexpensive, noninvasive and easy-to-use diagnostic methods. Salivary constituents that have been studied as potential diagnostic biomarkers for periodontal disease includes locally produced proteins of host and bacterial origin, genetic/genomic biomarkers such as DNA and mRNA of host origin, bacteria and bacterial products, ions, steroid hormones and volatile compounds. Conclusion: Periodontal oral diagnostic devices will enable screening of large populations, more quickly and effectively. Use of salivary biomarkers to sample large populations will help to identify at-risk groups more effectively and increase access to treatment for those most at need, thereby, improving public health.
Fulltext Codon usage and codon pair patterns in non-grass monocot genomes

Mazumdar P, Binti Othman R, Mebus K, Ramakrishnan N, Ann Harikrishna J

Ann Bot, 2017 Nov 28;120(6):893-909.
PMID: 29155926 DOI: 10.1093/aob/mcx112

Background and Aims: Studies on codon usage in monocots have focused on grasses, and observed patterns of this taxon were generalized to all monocot species. Here, non-grass monocot species were analysed to investigate the differences between grass and non-grass monocots.
Methods: First, studies of codon usage in monocots were reviewed. The current information was then extended regarding codon usage, as well as codon-pair context bias, using four completely sequenced non-grass monocot genomes (Musa acuminata, Musa balbisiana, Phoenix dactylifera and Spirodela polyrhiza) for which comparable transcriptome datasets are available. Measurements were taken regarding relative synonymous codon usage, effective number of codons, derived optimal codon and GC content and then the relationships investigated to infer the underlying evolutionary forces.
Key Results: The research identified optimal codons, rare codons and preferred codon-pair context in the non-grass monocot species studied. In contrast to the bimodal distribution of GC3 (GC content in third codon position) in grasses, non-grass monocots showed a unimodal distribution. Disproportionate use of G and C (and of A and T) in two- and four-codon amino acids detected in the analysis rules out the mutational bias hypothesis as an explanation of genomic variation in GC content. There was found to be a positive relationship between CAI (codon adaptation index; predicts the level of expression of a gene) and GC3. In addition, a strong correlation was observed between coding and genomic GC content and negative correlation of GC3 with gene length, indicating a strong impact of GC-biased gene conversion (gBGC) in shaping codon usage and nucleotide composition in non-grass monocots.
Conclusion: Optimal codons in these non-grass monocots show a preference for G/C in the third codon position. These results support the concept that codon usage and nucleotide composition in non-grass monocots are mainly driven by gBGC.
Fulltext Recent development and challenges in extraction of phytonutrients from palm oil

Hoe BC, Chan ES, Nagasundara Ramanan R, Ooi CW

Compr Rev Food Sci Food Saf, 2020 11;19(6):4031-4061.
PMID: 33337051 DOI: 10.1111/1541-4337.12648

Phytonutrients are plant-derived bioactives which are widely utilized as colorants or supplements in food, cosmetic, and pharmaceutical products. To meet the global demand for phytonutrients, oil palm has emerged as a promising source of phytonutrients on account of its large-scale plantation worldwide and high oil productivity. Phytonutrients including carotenoids, tocols, sterols, squalene, phospholipids, coenzyme Q10, and polyphenols can be found in crude palm oil as well as in the byproducts (e.g. palm oil mill effluent and palm-pressed fiber oil) generated from the palm oil milling process. However, the high viscosity and semisolid properties of palm oil are problematic in phytonutrient extraction. Another major challenge is the retention of the sensitive phytonutrients during the extraction process. Over the years, the advances in the extraction methods have improved the extractability of phytonutrients. The emerging extraction methods can operate under mild conditions to mitigate the risk of phytonutrient degradation. This review outlines the types of phytonutrient in palm oil and their extraction strategies. The working principles and operating conditions of extraction methods are discussed along with their potential and limitations in terms of extraction efficiency and practicability. The methods for pretreatment of feedstocks for improving extraction efficiency are also highlighted. The challenges in the extraction of phytonutrient from palm oil feedstock are summarized. Lastly, we provide suggestions for overcoming the limitations and improving the performances of phytonutrient extraction.
Lactation failure in crossbred Sahiwal Friesian cattle

Murugaiyah M, Ramakrishnan P, Omar AR, Knight CH, Wilde CJ

J Dairy Res, 2001 May;68(2):165-74.
PMID: 11504381

Milk producers in Malaysia make extensive use of crossbred Sahiwal Friesian dairy cattle. These animals have, however, been found susceptible to lactation failure. A survey of cows in an experimental herd of F1 Sahiwal Friesian animals indicated that, in 30% of animals, milk yield decreased to negligible levels within the first 8 weeks post partum. Lactation failure was associated with a progressive increase in the amount of residual milk left in the udder after normal milking. By week 3 of lactation, residual milk volume was significantly greater than that in animals that, based on previous lactation history were not susceptible to lactation failure, and accounted for up to 30% of milk available at the morning milking. The cellular consequences of residual milk accumulation were evident in the activities of acetyl-CoA carboxylase, fatty acid synthetase and galactosyltransferase, key enzyme markers of cellular differentiation, which decreased in glands undergoing lactation failure and were lower than values measured in tissue of control cows. Mammary cell number, estimated by tissue DNA content, was also reduced in animals undergoing lactation failure. These indices of mammary development indicate that lactation failure is the result of premature involution in susceptible animals. Premature involution is a predictable consequence of progressive milk stasis in failing lactation, and attributable to an increase in autocrine feedback by inhibitory milk constituents. The progressive increase in residual milk is, on the other hand, unlikely to be attributable to impaired mammary development. Measurements of milk storage during milk accumulation showed no differences between control and lactation failure cows in the distribution of milk between alveolar and cisternal storage compartments. We conclude that lactation failure in Sahiwal Friesian cows is due to a failure of milk removal, and probably the result of an impaired milk ejection reflex rather than to the glands' milk storage characteristics.
Reusing colored industrial wastewaters in a photofermentation for enhancing biohydrogen production by using ultrasound stimulated Rhodobacter sphaeroides

Budiman PM, Wu TY, Ramanan RN, Md Jahim J

Environ Sci Pollut Res Int, 2017 Jul;24(19):15870-15881.
PMID: 28409433 DOI: 10.1007/s11356-017-8807-x

One-time ultrasonication pre-treatment of Rhodobacter sphaeroides was evaluated for improving biohydrogen production via photofermentation. Batch experiments were performed by varying ultrasonication amplitude (15, 30, and 45%) and duration (5, 10, and 15 min) using combined effluents from palm oil as well as pulp and paper mill as a single substrate. Experimental data showed that ultrasonication at amplitude 30% for 10 min (256.33 J/mL) achieved the highest biohydrogen yield of 9.982 mL H2/mLmedium with 5.125% of light efficiency. A maximum CODtotal removal of 44.7% was also obtained. However, when higher ultrasonication energy inputs (>256.33 J/mL) were transmitted to the cells, biohydrogen production did not improve further. In fact, 20.6% decrease of biohydrogen yield (as compared to the highest biohydrogen yield) was observed using the most intense ultrasonicated inoculum (472.59 J/mL). Field emission scanning electron microscope images revealed the occurrence of cell damages and biomass losses if ultrasonication at 472.59 J/mL was used. The present results suggested that moderate ultrasonication pre-treatment was an effective technique to improve biohydrogen production performances of R. sphaeroides.
Field's stain--a rapid staining method for Acanthamoeba spp

Pirehma M, Suresh K, Sivanandam S, Anuar AK, Ramakrishnan K, Kumar GS

Parasitol Res, 1999 Oct;85(10):791-3.
PMID: 10494803

Acanthamoeba sp. is a free-living amoeba known to cause chronic central nervous system infection or eye infection in humans. Many cases remain undetected for want of a good detection system. We report for the first time a rapid staining method to facilitate the identification of Acanthamoeba sp. using the modified Field's staining technique. A. castellanii, which was used in the present experiment, is maintained in our laboratory in mycological peptone medium (Gibco). The cultures were pooled together and smears were made on glass slides for staining purposes. Different types of stains such as Field's stain, modified Field's stain, Wright's stain, Giemsa stain, Ziehl-Neelsen stain, and trichrome stain were used to determine the best stain for the identification of this amoeba. The concentration of various stains and the duration of staining were varied to provide the best color and contrast for each stain. Acanthamoeba was also obtained from the brain of experimentally infected mice and was stained with various stains as mentioned above to determine the best stain for use in identifying the presence of this parasite in experimentally infected animals. The modified Field's stain gives a very good color contrast as compared with other stains. Furthermore, it takes only 20 s to be carried out using the least number of reagents, making it suitable for both laboratory and field use.
Irregular shedding of Blastocystis hominis

Vennila GD, Suresh Kumar G, Khairul Anuar A, Rajah S, Saminathan R, Sivanandan S, et al.

Parasitol Res, 1999 Feb;85(2):162-4.
PMID: 9934969

The shedding pattern of the protozoan parasite, Blastocystis hominis, is investigated in man and in experimental animal infections. The shedding pattern of the vacuolar and cystic forms of Blastocystis hominis in infected individuals have been shown in the present study to be irregular. The study shows that there is marked fluctuation in the shedding of the parasite from day to day, varying from as high as 17 to 0 per x40 microscopic field. The cystic stages when estimated in 8 Blastocystis-infected individuals ranged from as high as 7.4x10(5) cysts per gram of stool to 0. The shedding of cystic and vacuolar forms observed over a period of 20 days in experimentally-infected Wistar rats were not only shown to be irregular but the amount varied from host to host. The study has important diagnostic implications in that the stool samples must be collected more than once from patients showing clinical signs and symptoms to eliminate the cause of it to Blastocystis. The study also shows that there are asymptomatic individuals who pass a large amount of cysts as such individuals should be treated to prevent transmission to others.
Late blight in tomato: insights into the pathogenesis of the aggressive pathogen Phytophthora infestans and future research priorities

Mazumdar P, Singh P, Kethiravan D, Ramathani I, Ramakrishnan N

Planta, 2021 May 08;253(6):119.
PMID: 33963935 DOI: 10.1007/s00425-021-03636-x

MAIN CONCLUSION: This review provides insights into the molecular interactions between Phytophthora infestans and tomato and highlights research gaps that need further attention. Late blight in tomato is caused by the oomycota hemibiotroph Phytophthora infestans, and this disease represents a global threat to tomato farming. The pathogen is cumbersome to control because of its fast-evolving nature, ability to overcome host resistance and inefficient natural resistance obtained from the available tomato germplasm. To achieve successful control over this pathogen, the molecular pathogenicity of P. infestans and key points of vulnerability in the host plant immune system must be understood. This review primarily focuses on efforts to better understand the molecular interaction between host pathogens from both perspectives, as well as the resistance genes, metabolomic changes, quantitative trait loci with potential for improvement in disease resistance and host genome manipulation via transgenic approaches, and it further identifies research gaps and provides suggestions for future research priorities.
Fulltext Investigation into mass loading sensitivity of sezawa wave mode-based surface acoustic wave sensors

Mohanan AA, Islam MS, Ali SH, Parthiban R, Ramakrishnan N

Sensors (Basel), 2013;13(2):2164-75.
PMID: 23389346 DOI: 10.3390/s130202164

In this work mass loading sensitivity of a Sezawa wave mode based surface acoustic wave (SAW) device is investigated through finite element method (FEM) simulation and the prospects of these devices to function as highly sensitive SAW sensors is reported. A ZnO/Si layered SAW resonator is considered for the simulation study. Initially the occurrence of Sezawa wave mode and displacement amplitude of the Rayleigh and Sezawa wave mode is studied for lower ZnO film thickness. Further, a thin film made of an arbitrary material is coated over the ZnO surface and the resonance frequency shift caused by mass loading of the film is estimated. It was observed that Sezawa wave mode shows significant sensitivity to change in mass loading and has higher sensitivity (eight times higher) than Rayleigh wave mode for the same device configuration. Further, the mass loading sensitivity was observed to be greater for a low ZnO film thickness to wavelength ratio. Accordingly, highly sensitive SAW sensors can be developed by coating a sensing medium over a layered SAW device and operating at Sezawa mode resonance frequency. The sensitivity can be increased by tuning the ZnO film thickness to wavelength ratio.
Improved mannan-degrading enzymes' production by Aspergillus niger through medium optimization

Mohamad SN, Ramanan RN, Mohamad R, Ariff AB

N Biotechnol, 2011 Feb 28;28(2):146-52.
PMID: 20970530 DOI: 10.1016/j.nbt.2010.10.008

The effect of different carbon and nitrogen sources on the production of mannan-degrading enzymes, focussing on β-mannanase, by Aspergillus niger was investigated using shake flask culture. The β-mannanase activity obtained during growth of A. niger on guar gum (GG, 1495 nkat mL(-1)) was much higher than those observed on other carbon substrates, locust bean gum (1148 nkat mL(-1)), α-cellulose (10.7 nkat mL(-1)), glucose (8.8 nkat mL(-1)) and carboxymethylcellulose (4.6 nkat mL(-1)). For fermentation using GG as a carbon source, bacteriological peptone gave the highest β-mannanase activity (1744 nkat mL(-1)) followed by peptone from meat (1168 nkat mL(-1)), yeast extract (817 nkat mL(-1)), ammonium sulphate (241 nkat mL(-1)), ammonium nitrate (113 nkat mL(-1)) and ammonium chloride (99 nkat mL(-1)) when used as a nitrogen source. The composition of bacteriological peptone and initial pH of the medium were further optimized using response surface methodology (RSM). Medium consisted of 21.3 g L(-1) GG and 57 g L(-1) peptone with initial culture pH of 5.5 was optimum for β-mannanase production (2063 nkat mL(-1)) by A. niger. The β-mannanase production obtained in this study using A. niger was significantly higher than those reported in the literature.
Fulltext Genetic predisposition of LEPR (rs1137101) gene polymorphism related to type 2 diabetes mellitus - a meta-analysis

Veerabathiran R, P A, Bk I, D R, Rs AH

Ann Med, 2023;55(2):2302520.
PMID: 38198642 DOI: 10.1080/07853890.2024.2302520

Background: Type 2 diabetes mellitus (T2DM) is a multifaceted disease appropriate to elevated blood glucose levels resulting from decreased insulin and beta-cell activity. Using a case-control methodology, researchers have examined the relationship between polymorphisms in LEPR and T2DM in a population from south India.Materials and Methods: We conducted a genetic analysis of 311 participants, and results were accomplished using a case-control study, a meta-analysis of previous studies on LEPR was conducted, and type 2 diabetes genotype distribution across various geographical regions Malaysians, Chinese Han, Kuwait, Iran, Mongolia, and Han Chinese, Greece, Saudi, India (North India, Punjabi), (South India, Tamilnadu). The study involved 254 prospective investigations, and nine association studies were preferred according to preset criteria. Studies were assessed for quality using the Hardy-Weinberg equilibrium (HWE) and the Newcastle-Ottawa Scale (NOS). An analysis of the genetic models was conducted to determine their relationship, statistical analysis was utilized to calculate odds ratios (ORs) and matching 95% confidence intervals (CIs).Results: The LEPR-rs1137101 polymorphism in the case-control study was associated with a significant increase in the risk of type 2 diabetes. A meta-analysis revealed a connection between LEPR gene polymorphism (rs1137101) and type 2 diabetes risk. Investigators might gain a more profound thought on the significance of the identified genetic variation and its impact on the chance of developing type 2 diabetes by verifying and strengthening previously reported findings. The model of fixed effects was chosen due to the low heterogeneity, and significant associations were observed in the allelic (OR = 0.79, 95% CI [0.70-0.87]), homozygote (OR = 0.58, 95% CI [0.46-0.72]), dominant (OR = 0.66, 95% CI [0.56-0.79]), and recessive (OR = 0.83, 95% CI [0.71-0.96]) genetic models. A Begg's funnel plot and Egger's test indicated no publication bias. These findings suggest that the rs1137101 variant in the LEPR gene has been linked to a higher risk of T2DM.Conclusions: A larger sample size, however, is required for further research, and consideration of potential confounding factors is needed to validate these associations. Understanding the implications of LEPR gene polymorphisms in T2DM susceptibility may contribute to personalized treatment strategies for patients with T2DM.
Fulltext Colorimetric quantification of sucrose in presence of thermo-sensitive polymers present in aqueous two-phase systems

Ramalakshmi S, Ooi CW, Ariff AB, Ramanan RN

MethodsX, 2014;1:229-32.
PMID: 26150957 DOI: 10.1016/j.mex.2014.09.006

The use of biodegradable material such as simple carbohydrates and recyclable material such as thermo-sensitive polymers is in need to develop a sustainable aqueous two-phase system (ATPS) for the purification of biomolecules. Accurate determination of sucrose concentration is important in liquid-liquid equilibrium (LLE) study of carbohydrate-based ATPS. The well-established phenol-sulfuric acid method has been widely employed in the measurement of carbohydrate concentration. However, the presence of thermo-sensitive polymers, which has a lower critical solution temperature (LCST) below room temperature, in carbohydrate samples could hamper the precision of spectrophotometric analysis due to the formation of two phases or cloudiness in the sample. Thus, the following modifications were made in an attempt to eliminate the interference occurred during conventional phenol-sulfuric acid assay.•The modified assay for sucrose quantification was performed at an ice-cold temperature throughout the reaction in order to avoid the interference from thermo-sensitive polymers.•This method required a sample volume of 3 μL and hence the volume of other reagents employed was also considerably reduced.•The absorbance was measured at 520 nm which allowed a longer linearity range (0.05-7.5%, w/v).
Efficacy of guided bone regeneration using composite bone graft and resorbable collagen membrane in Seibert's Class I ridge defects: radiological evaluation

Saravanan P, Ramakrishnan T, Ambalavanan N, Emmadi P, John TL

J Oral Implantol, 2013 Aug;39(4):455-62.
PMID: 23964779 DOI: 10.1563/AAID-JOI-D-10-00211

The purpose of the study was to evaluate radiologically the efficacy of guided bone regeneration using composite bone graft (autogenous bone graft and anorganic bovine bone graft [Bio-Oss]) along with resorbable collagen membrane (BioMend Extend) in the augmentation of Seibert's class I ridge defects in maxilla. Bone width was evaluated using computerized tomography at day 0 and at day 180 at 2 mm, 4 mm, and 6 mm from the crest. There was a statistically significant increase in bone width between day 0 and day 180 at 2 mm, 4 mm, and 6 mm from the crest. The results of the study demonstrated an increase in bone width of Seibert's class I ridge defects in the maxilla of the study patients.
An effective strategy for unit commitment of microgrid power systems integrated with renewable energy sources including effects of battery degradation and uncertainties

Manoharan P, Chandrasekaran K, Chandran R, Ravichandran S, Mohammad S, Jangir P

Environ Sci Pollut Res Int, 2024 Feb;31(7):11037-11080.
PMID: 38217814 DOI: 10.1007/s11356-023-31608-z

The large use of renewable sources and plug-in electric vehicles (PEVs) would play a critical part in achieving a low-carbon energy source and reducing greenhouse gas emissions, which are the primary cause of global warming. On the other hand, predicting the instability and intermittent nature of wind and solar power output poses significant challenges. To reduce the unpredictable and random nature of renewable microgrids (MGs) and additional unreliable energy sources, a battery energy storage system (BESS) is connected to an MG system. The uncoordinated charging of PEVs offers further hurdles to the unit commitment (UC) required in contemporary MG management. The UC problem is an exceptionally difficult optimization problem due to the mixed-integer structure, large scale, and nonlinearity. It is further complicated by the multiple uncertainties associated with renewable sources, PEV charging and discharging, and electricity market pricing, in addition to the BESS degradation factor. Therefore, in this study, a new variant of mixed-integer particle swarm optimizer is introduced as a reliable optimization framework to handle the UC problem. This study considers six various case studies of UC problems, including uncertainties and battery degradation to validate the reliability and robustness of the proposed algorithm. Out of which, two case studies defined as a multiobjective problem, and it has been transformed into a single-objective model using different weight factors. The simulation findings demonstrate that the proposed approach and improved methodology for the UC problem are effective than its peers. Based on the average results, the economic consequences of numerous scenarios are thoroughly examined and contrasted, and some significant conclusions are presented.
Molecular docking studies of selected medicinal drugs as dengue virus-2 protease inhibitors

Rufaidah Othman, Saiful Anuar Karsani, Rozana Othman, Aida Baharuddin, Ramakrishnan NR, Noorsaadah Abd. Rahman, et al.

Sains Malaysiana, 2017;46:1865-1875.

Dengue is a potentially deadly disease with no effective drug. An in silico molecular docking was performed using Autodock
4.2.6 to investigate the molecular interactions between protease inhibitors, comprising antibiotic derivatives namely
doxycycline (3), rolitetracycline (5) and a non-steroidal anti-inflammatory drug (NSAID), meclofenamic acid (4), against
the NS2B-NS3 protease from dengue virus-2 (DENV-2). The non-competitive inhibitor (3) showed lower binding energy
(-5.15 kcal/mol) than the predicted competitive inhibitors 4 and 5 (-3.64 and -3.21 kcal/mol, respectively). Structural
analyses showed compound 3 that bound to a specific allosteric site, interacted with Lys74, a significant amino acid
residue bonded to one of the catalytic triad, Asp75. Compounds 4 and 5 showed direct binding with two of the catalytic
triad, His51 and Ser135, hence, predicted to be competitive inhibitors.
Optimization of an induction strategy for improving interferon-alpha2b production in the periplasm of Escherichia coli using response surface methodology

Azaman SN, Ramakrishnan NR, Tan JS, Rahim RA, Abdullah MP, Ariff AB

Biotechnol Appl Biochem, 2010 Aug;56(4):141-50.
PMID: 20604747 DOI: 10.1042/BA20100104

Induction strategies for the periplasmic production of recombinant human IFN-alpha2b (interferon-alpha2b) by recombinant Escherichia coli Rosetta-gami 2(DE3) were optimized in shake-flask cultures using response surface methodology based on the central composite design. The factors included in the present study were induction point, which related to the attenuance of the cell culture, IPTG (isopropyl beta-D-thiogalactoside) concentration and induction temperature. Second-order polynomial models were used to correlate the abovementioned factors to soluble periplasmic IFN-alpha2b formation and percentage of soluble IFN-alpha2b translocated to the periplasmic space of E. coli. The models were found to be significant and subsequently validated. The proposed induction strategies consisted of induction at an attenuance of 4 (measured as D600), IPTG concentration of 0.05 mM and temperature of 25 degrees C. The optimized induction strategy reduced inclusion-body formation as evidenced by electron microscopy and yielded 323.8 ng/ml of IFN-alpha2b in the periplasmic space with translocation of 74% of the total soluble product. In comparison with the non-optimized condition, soluble periplasmic production and the percentage of soluble IFN-alpha2b translocated to the periplasmic space obtained in optimized induction strategies were increased by approx. 20-fold and 1.4-fold respectively.

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