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Optimization and modeling studies on the production of a new fibrinolytic protease using Streptomyces radiopugnans_VITSD8

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Frontiers in Biology 2018年第1期13卷 70-77页

作者： Dhamodharan Duraikannu subathra devi chandrasekaran School of Biosciences and Technology VIT University Vellore Tamil Nadu lndia

BACKGROUND： The current study demonstrated the possibility of statistical design tools combination with computational tools for optimization of fermentation conditions for enhanced fibrinolytic protease production. METHODS： The effects of using different carbon and nitrogen sources for protease production by Streptomyces radiopugnans_VITSD8 were examined by a full factorial design method. The incubation time, temperature, pH of the medium, and RPM were assessed by the predictable one factor at a time （OFAT） method. Optimization was carried out using starch and oat meal as carbon source, nitrogen source as peptic and malt extract using Fractional Factorial Design （FFD）. The analysis was further continued for medium volume, temperature, initial medium pH, inoculum concentration, high determination co-efficient as （R＇-0.965）, and lower determination co-efficient of variation （CV-8.19%）, which defines a reliable and accurate experimental value. RESULTS： Analysis of variance by the fixed slope effect by temperature and starch; temperature and L-aspargine, temperature and oat meal, temperature and peptic extracts, temperature and pH, temperature and duration of incubation were more vital for protease production at an interactive level. Response surface plots revealed that temperature, starch, and peptic extracts affix critical concerning in temperature. Programming estimated a 28% increase in protease production. Incubation temperature and medium volume portrayed extreme impact among all factor. Starch, peptic and temperature play an important regulatory role in protease production. Optimium temperature for protease production was 33~C. The ratio of carbon and nitrogen sources and pH were the major regulatory factors in protease production by Streptomyces radiopugnans_VITSD8. It demonstrated a 4% noteworthy change in condition. CONCLUSION： Among all the selected parameters, temperature was the most intuitive factor, demonstrating a notable connection with the type of medi

关键词： Protease Streptomyces radiopugnans_VITSD8 Full Factorial design (FFD) fermentation optimization RSM

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Media optimization for extracellular amylase production by Pseudomonas balearica vitps19 using response surface methodology

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Frontiers in Biology 2018年第2期13卷 123-129页

作者： Moni Philip Jacob Kizhakedathil subathra devi chandrasekaran Department of Biotechnology School of Biosciences and Technology VIT University Vellore -632014 Tamil Nadu India

BACKGROUND： In this study, we optimized the process for enhancing amylase production from Pseudomonas balearica VITPS 19 isolated from agricultural lands in Kolathur, India. METHODS： Process optimization for enhancing amylase production from the isolate was carried out by Response Surface Methodology （RSM） with optimized chemical and physical sources using Design expert v.7.0. A central composite design was used to evaluate the interaction between parameters. Interaction between four factors - maltose （C-source）, malt extract （N- source）, pH, and CaCl2 was studied. RESULTS： The factors pH and CaCl2 concentration were found to affect amylase production. Validation of the experiment showed a nearly twofold increase in alpha amylase production. CONCLUSION： Amylase production was thus optimized and increased yield was achieved.

关键词： Pseudomonas balearica VITPS19 alpha amylase optimization response surface methodology central composite design pH

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Strain improvement, optimization and purification studies for enhanced production of streptokinase from Streptococcus uberis TNA-M1

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Frontiers in Biology 2017年第5期12卷 376-384页

作者： Teetam Ghosal Nikita Augustine Ashwini Siddapur Vaishnavi Babu Merlyn Keziah Samuel subathra devi chandrasekaran School of Biosciences and Technology VIT University Vellore-632014 TN India

BACKGROUND： Screening of isolates for their potency to produce streptokinase was an important criterion of this research. The current study emphasizes the strain improvement, optimization and purification studies for enhanced production of streptokinase from Streptococcus uberis TNA-M1 isolated from bovine milk. METHODS： The study was carried out on samples collected from milk sample. Primary screening and characterization is used as an excellent source for the isolation of 13-hemolytic organisms. Strain improvement was done by both physical ＆ chemical mutagenesis. The enzyme activity was checked by clot lysis assay and confirmed by fibrin plate method. The partially purified and crude enzyme were analysed by high-performance liquid chromatography. Molecular weight ＆ enzyme purity was checked by SDS -PAGE, further confirmed by fibrin zymography. RESULTS： Out of the 3 isolated strains, only one isolate expressed 13-haemolysis with streptokinase （SK） activity. Based on the results of radial caseinolytic assay and blood clot dissolving assay, isolate TNA-M1 demonstrated the highest streptokinase activity. Based on morphological, biochemical and molecular characterization, it was identified as Streptococcus uberis and the strain was named as Streptococcus uberis TNA-M1. The results indicated that ultra-violet （UV） and ethyl methane sulfonate （EMS） were effective mutagenic agents for strain improvement of Streptococcus uberis TNA-M1 and enhanced SK productivity. HPLC analysis was performed in order to confirm the presence of streptokinase with the similar retention time （0.875 min） with its standard （0.854） min. SDS-PAGE of the enzyme showed protein band of approximately 47 kDa and confirmed by fibrin zymography. It exhibited fibrinolytic activity, which was more potent than other fibrinolytic enzymes. Glucose and peptone were recorded to be the optimum carbon and nitrogen sources respectively. CONCLUSION： Thus this study presents its novelty by highlighting the potentia

关键词： Streptokinase Streptococcus uberis clot busters mutagenesis optimization

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Transforming nanoscale VO_(2)(B) into a scalable sodium-ion electrode

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Nano Research 2024年第10期17卷 8809-8818页

作者： Yunkai Luo Swetha chandrasekaran Bintao Hu Randy Chen Marcus Worsley Bruce Dunn Department of Materials Science and Engineering University of CaliforniaLos AngelesCA 90095USA Lawrence Livermore National Laboratory CA 94550USA

The intermittent nature of renewable energies requires highly reliable grid-level energy storage approaches.A critical consideration in developing this technology is the areal capacity which determines battery performance and influences the cost of battery *** related importance is finding new ways of developing scalable *** recent years,threedimensional(3D)printing of conductive scaffolds has emerged as an alternative to overcome the scalability limitations of commercial tape cast *** research carried out in the current study demonstrates a successful scalability pathway for nanoscale VO_(2)(B),a desirable cathode for sodium-ion batteries which has a nano-flower morphology with a crystallite size<20 *** electrodepositing VO_(2)(B)onto a graphene aerogel scaffold,we were able to achieve mass loading of over 100 mg·cm^(-2) and still possess an areal capacity of 10 mAh·cm^(-2) at a current density of 5 mA·cm^(-2).Moreover,after 1000 cycles,these electrodes retained 75% to 80% of their initial *** at high loading levels,the electrodeposited VO_(2)(B)exhibits pseudocapacitive material signatures such as a box-like voltammetry response,linear galvanostatic response,and no phase change upon *** scalability of the VO_(2)(B)electrode is demonstrated in a series of experiments which show the areal capacity to scale upon increase in both mass loading and electrode thickness,with only small changes in specific *** study establishes that nanoscale materials can be scaled up to achieve thick electrodes without compromising their electrochemical properties.

关键词： nano VO_(2)(B) sodium-ion battery scalable electrodes three-dimensional(3D)printed scaffold additive manufacturing

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近海三角张力腿平台钢筋束假定失效研究

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哈尔滨工程大学学报（英文版） 2024年第1期23卷 182-200页

作者： Srinivasan chandrasekaran Ganta Shanmukha Rao Department of Ocean Engineering Indian Institute of TechnologyMadras 600036India

Offshore triceratops is one of the successful manifestations of the form-dominant design approaches deployable in ultra-deepwater oil and gas *** deck’s geometric shape and partial isolation from the legs counteract lateral *** are position-restrained to the sea bed by taut-moored tendons,while ball joints partially isolate the deck from the buoyant ***,compliance in the horizontal plane imposes large displacements,intuiting the necessity to examine tendon *** analysis of triceratops under wave and wind combined action is carried out under the postulated conditions of a tendon failure.10-yr,100-yr,and 1000-yr post-Katrina hurricane conditions are assumed as loading to the *** confirm a marginal increase in the natural periods of stiff degrees of freedom even under postulated failure conditions,ensuring good adaptability to ultra-deep *** postulated failure,the tension of adjacent tendons varies significantly,causing a shift to the mean position of the *** life is significantly reduced under the postulated failure of tendons,making the platform free-floating without affecting its *** also show that the pitch response of the deck is a clear manifestation of the postulated failure,which is otherwise absent due to the presence of ball *** attempted study deliberates on the fatigue life of tendons,assessing the platform’s suitability to ultra-deep waters and identifying the vulnerable legs for the chosen load combinations.

关键词： Ball joints Tendons Buoyant legs Fatigue life Irregular waves Postulated failure

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Quantifying Kinematic Tremor in an NGLY1-Deficient Individual: A Case Study

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Case Reports in Clinical Medicine 2024年第1期13卷 25-36页

作者： Brock Futrell Christopher Alexander Malaya Dacia Martinez Diaz Christian Alfaro Hannah Elizabeth Gustafson Subhalakshmi chandrasekaran Rhea Mohan Phatak Bernhard Suter Charles Shannon Layne Department of Health and Human Performance University of Houston Houston USA Center for Neuromotor and Biomechanics Research University of Houston Houston USA Department of Computer Science and Engineering Texas A&M University College Station USA Blue Bird Circle Rett Center Texas Children’s Hospital Houston USA Baylor College of Medicine Houston USA Center for NeuroEngineering and Cognitive Science University of Houston Houston USA

NGLY1 Deficiency is an autosomal recessive congenital disorder that has been identified in less than 100 individuals. Most individuals with NGLY1 Deficiency display hyperkinetic movement disorders, including choreiform, athetoid, dystonic myoclonic, dyskinetic, and dysmetric movements. Developing a consistent and concise consensus on the classification and evaluation of tremors is essential to forward the research and treatment of tremors. It has also been reported that some individuals with NGLY1 Deficiency demonstrate tremor, but such tremor has never been formally investigated. The primary objective of this study is to determine if an individual with NGLY1 Deficiency demonstrates an identifiable tremor during a series of arm movements and, if so, describe the frequency and power characteristics of that tremor. Arm movement kinematics were obtained using a 16-camera Vicon system, and time series trajectory waveforms for three planes of a marker placed on the hand were developed. Custom MATLAB scripts were utilized to compute Fast Fourier Transformations of the data within the identified waveform segments. A mean frequency of 2.30 Hz (SD = 1.05) with a mean power of 5.02 |P1(f)| (SD = 4.63) suggests that our participant’s kinematic data did display a persistent tremor in both hands across all tasks and movement planes. Analyses of the reaching hand and the non-reaching hand suggest the participant displayed an action tremor in both postural and intention (kinetic) tremors. Future directions should include assessing additional individuals with NGLY1 Deficiency to determine if the tremor is a distinguishable disorder behavior. Additionally, evaluating other anatomical sites, such as the elbow, head, and lower limbs, would provide further insights into the characteristics of this tremor.

关键词： Tremor NGLY Fast Fourier Transformation Reaching Hyperkinetic Movement

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3-Dimensional Kinematic Comparison of Arm Movements between an Individual with NGLY1 Deficiency and a Neurotypical Individual

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Case Reports in Clinical Medicine 2024年第4期13卷 122-146页

作者： Charles S. Layne Christopher A. Malaya Brock Futrell Dacia Martinez Diaz Christian Alfaro Hannah E. Gustafson Subhalakshmi chandrasekaran Rhea M. Phatak Bernhard Suter Department of Health and Human Performance University of Houston Houston TX USA Center for Neuromotor and Biomechanics Research University of Houston Houston TX USA Center for Neuro Engineering and Cognitive Science University of Houston Houston TX USA Department of Computer Science and Engineering Texas A&M University College Station TX USA Blue Bird Circle Rett Center Texas Children&#8217s Hospital Houston TX USA Baylor College of Medicine Houston TX USA

NGLY1 Deficiency is an ultra-rare autosomal recessively inherited disorder. Characteristic symptoms include among others, developmental delays, movement disorders, liver function abnormalities, seizures, and problems with tear formation. Movements are hyperkinetic and may include dysmetric, choreo-athetoid, myoclonic and dystonic movement elements. To date, there have been no quantitative reports describing arm movements of individuals with NGLY1 Deficiency. This report provides quantitative information about a series of arm movements performed by an individual with NGLY1 Deficiency and an aged-matched neurotypical participant. Three categories of arm movements were tested: 1) open ended reaches without specific end point targets;2) goal-directed reaches that included grasping an object;3) picking up small objects from a table placed in front of the participants. Arm movement kinematics were obtained with a camera-based motion analysis system and “initiation” and “maintenance” phases were identified for each movement. The combination of the two phases was labeled as a “complete” movement. Three-dimensional analysis techniques were used to quantify the movements and included hand trajectory pathlength, joint motion area, as well as hand trajectory and joint jerk cost. These techniques were required to fully characterize the movements because the NGLY1 individual was unable to perform movements only in the primary plane of progression instead producing motion across all three planes of movement. The individual with NGLY1 Deficiency was unable to pick up objects from a table or effectively complete movements requiring crossing the midline. The successfully completed movements were analyzed using the above techniques and the results of the two participants were compared statistically. Almost all comparisons revealed significant differences between the two participants, with a notable exception of the 3D initiation area as a percentage of the complete movement. The stati

关键词： NGLY1 Deficiency Developmental Disorders Kinematics 3 Dimensional Analyses

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Variation of Flow Field Around Twin Cylinders with and Without the Outer Perforated Cylinder ? Numerical Study

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China Ocean Engineering 2016年第5期30卷 763-771页

作者： chandrasekaran SRINIVASAN N.MADHAVI Department of Ocean Engineering Indian Institute of Technology Madras Department of Ocean Engineering IIT Madras

Presence of the outer perforated cylinder reduces the direct wave impact on the inner cylinder, which has been testified by many researchers. However, the force reduction mechanism, which is complicated due to the wave-porous structure interaction, needs to be addressed in detail. The present study explains the mechanism with the aid of the computational fluid dynamics （CFD） tool STAR CCM＋. This package is chosen for its capabilities to simulate viscous and turbulence effects caused by passage of waves. For the present study, flow fields around the twin cylinders with different orientations are examined with and without the outer perforated cover. Mechanism contributing to the reduction of force on the existing structure is explained in physical terms, and force reduction is quantified. The present study has direct application in the retrofitting application of offshore members.

关键词： CFD offshore structure perforated cylinder hydrodynamic force water particle kinematics twin cylinders

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Appropriate Sub-band Selection in Wavelet Packet Decomposition for Automated Glaucoma Diagnoses

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International Journal of Automation and computing 2015年第4期12卷 393-401页

作者： chandrasekaran Raja Narayanan Gangatharan Department of Electronics and Communication Engineering Anjalai Ammal Mahalingam Engineering College Department of Electronics and Communication Engineering R.M.K.College of Engineering and Technology

The most common reason for blindness among human beings is *** increase of fluid pressure damages the optic nerve which gradually leads to irreversible loss of vision.A technique for automated screening of Glaucoma from the fundal retinal images is presented in this *** paper intends to explore the significance of both the approximate and detail coefficients through wavelet packet decomposition(WPD).Decomposition is done with "db3" wavelet function and the images are decomposed up to level-3producing 84 *** features,the energy and the entropy are calculated for each sub-band producing two feature matrices(158 images × 84 features).The above step is purely a statistical measure based on *** enhance the diagnostic accuracy,the second phase considers the structural(biological) region of interest(ROI) in the image and then extracts the same *** is worthy to note that direct biological features are not extracted to eliminate the drawbacks of segmentation whereas the biologically significant region is taken as ***,the detailed coefficient sub-bands(prominent edges) show more significance in the biological-ROI *** from enhancing the diagnostic accuracy by feature reduction,the paper intends to mark the significance indices,uniqueness and discrimination capability of the significant features(sub-bands) in both the ***,the crisp inputs are fed to the classifier ***,from the significant features of the biological-ROI feature matrices,the accuracy is raised to 85%which is notable than the accuracy of 79%achieved without considering the ROI.

关键词： Glaucoma wavelet packet decomposition feature reduction feature significance artificial neural networks.

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Automating Transfer Credit Assessment-A Natural Language Processing-Based Approach

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Computers, Materials & Continua 2022年第11期73卷 2257-2274页

作者： Dhivya chandrasekaran Vijay Mago Lakehead University Thunder BayOntarioP7B 5E1Canada

Student mobility or academic mobility involves students moving between institutions during their post-secondary education,and one of the challenging tasks in this process is to assess the transfer credits to be offered to the incoming *** general,this process involves domain experts comparing the learning outcomes of the courses,to decide on offering transfer credits to the incoming *** manual implementation is not only labor-intensive but also influenced by undue bias and administrative *** proposed research article focuses on identifying a model that exploits the advancements in the field of Natural Language Processing(NLP)to effectively automate this *** the unique structure,domain specificity,and complexity of learning outcomes(LOs),a need for designing a tailor-made model *** proposed model uses a clustering-inspired methodology based on knowledge-based semantic similarity measures to assess the taxonomic similarity of LOs and a transformer-based semantic similarity model to assess the semantic similarity of the *** similarity between LOs is further aggregated to form course to course *** to the lack of quality benchmark datasets,a new benchmark dataset containing seven course-to-course similarity measures is *** the inherent need for flexibility in the decision-making process the aggregation part of the model offers tunable parameters to accommodate different levels of *** providing an efficient model to assess the similarity between courses with existing resources,this research work also steers future research attempts to apply NLP in the field of articulation in an ideal direction by highlighting the persisting research gaps.

关键词： Articulation agreements higher education natural language processing semantic similarity

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