Femoral lengthening in achondroplasia: magnitude of lengthening in relation to patterns of callus, stiffness of adjacent joints and fracture.

Venkatesh, K P,Modi, H N,Devmurari, K,Yoon, J Y,Anupama, B R,Song, H R Published for the British Editorial Society of Bon 2009 The Bone & Joint Journal Vol.91 No.12

<P>Extensive limb lengthening may be indicated in achondroplastic patients who wish to achieve a height within the normal range for their population. However, increasing the magnitude of lengthening is associated with further complications particularly adjacent joint stiffness and fractures. We studied the relationship between the magnitude of femoral lengthening and callus pattern, adjacent joint stiffness and fracture of the regenerate bone in 40 femoral lengthenings in 20 achondroplastic patients. They were divided into two groups; group A had lengthening of less than 50% and group B of more than 50% of their initial femoral length. The patterns of radiological callus formation were classified according to shape, type and features. The incidence of callus features, knee stiffness and regenerate bone fracture were analysed in the two groups. Group B was associated with an increased incidence of concave, lateral and central callus shapes, adjacent joint and stiffness and fracture. Statistically, the incidence of stiffness in adjacent joints and regenerate bone fracture was significantly associated with the magnitude of lengthening. We suggest that careful radiological assessment of the patterns of callus formation is a useful method for the evaluation and monitoring of regenerate bone.</P>

Comparative Analysis of Effect of Density, Insertion Angle and Reinsertion on Pull-Out Strength of Single and Two Pedicle Screw Constructs Using Synthetic Bone Model

Venkatesh Krishnan,Vicky Varghese,Gurunathan Saravana Kumar 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.3

Study Design: Biomechanical study. Purpose: To determine the effect of density, insertion angle and reinsertion on pull-out strength of pedicle screw in single and two screw-rod configurations. Overview of Literature: Pedicle screw pull-out studies have involved single screw construct, whereas two screws and rod constructs are always used in spine fusions. Extrapolation of results using the single screw construct may lead to using expensive implants or increasing the fusion levels specifically in osteoporotic bones. Methods: Single screw and two screw pull-out strength tests were carried out according to American Society for Testing and Materials F 543-07 on foam models to test the effect of density, insertion angle and reinsertion using poly axial pedicle screws. Results: Bone density was the most significant factor deciding the pull-out strength in both single and two screw constructs. The difference in pull-out strength between single screw and two screw configurations in extremely osteoporotic bone model (80 kg/m3) was 78%, whereas in the normal bone model it was 48%. Axial pull-out value was highest for the single screw configuration; in the two screw configuration the highest pull-out strength was at 10°–15°. There was an 18% reduction in pull-out strength due to reinsertion in single screw configuration. The reinsertion effect was insignificant in the two screw configuration. Conclusions: A significant difference in response of various factors on holding power of pedicle screw between single and two-screw configurations is evident. The percentage increase in pull-out strength between single and two screw constructs is higher for osteoporotic bone when compared to normal bone. Reinsertion has no significant effect on pull-out strength in the two screw rod configuration.

Modelling and Performance Analysis of UPQC with Digital Kalman Control Algorithm under Unbalanced Distorted Source Voltage conditions

Venkatesh Kumar,Rajeswari Ramachandran 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.6

In this paper, the generation of a reference current and voltage signal based on a Kalman filter is offered for a 3-phase 4wire UPQC (Unified Power Quality Conditioner). The performance of the UPQC is improved with source voltages that are distorted due to harmonic components. Despite harmonic and frequency variations, the Kalman filter is capable enough to determine the amplitude and the phase angle of load currents and source voltages. The calculation of the first state is sufficient to identify the fundamental components of the current, voltage and angle. Therefore, the Kalman state estimator is fast and simple. A Kalman based control strategy is proposed and implemented for a UPQC in a distribution system. The performance of the proposed control strategy is assessed for all possible source conditions with varying nonlinear and linear loads. The functioning of the proposed control algorithm with a UPQC is scrutinized and validated through simulations employing MATLAB/Simulink software. Using a FPGA SPATRAN 3A DSP board, the proposed algorithm is developed and implemented. A small-scale laboratory prototype is built to verify the simulation results. The stated control scheme for the UPQC reduces the following issues, voltage sags, voltage swells, harmonic distortions (voltage and current), unbalanced supply voltage and unbalanced power factor under dynamic and steady-state operating conditions.

Binary logistic regression analysis of hard palate dimensions for sexing human crania

Venkatesh Kamath,Muhammed Asif,Radhakrishna Shetty,Ramakrishna Avadhani 대한해부학회 2016 Anatomy & Cell Biology Vol.49 No.2

Sex determination is the preliminary step in every forensic investigation and the hard palate assumes significance in cranial sexing in cases involving burns and explosions due to its resistant nature and secluded location. This study analyzes the sexing potential of incisive foramen to posterior nasal spine length, palatine process of maxilla length, horizontal plate of palatine bone length and transverse length between the greater palatine foramina. The study deviates from the conventional method of measuring the maxillo-alveolar length and breadth as the dimensions considered in this study are more heat resistant and useful in situations with damaged alveolar margins. The study involves 50 male and 50 female adult dry skulls of Indian ethnic group. The dimensions measured were statistically analyzed using Student’s t test, binary logistic regression and receiver operating characteristic curve. It was observed that the incisive foramen to posterior nasal spine length is a definite sex marker with sex predictability of 87.2%. The palatine process of maxilla length with 66.8% sex predictability and the horizontal plate of palatine bone length with 71.9% sex predictability cannot be relied upon as definite sex markers. The transverse length between the greater palatine foramina is statistically insignificant in sexing crania (P=0.318). Considering a significant overlap of values in both the sexes the palatal dimensions singularly cannot be relied upon for sexing. Nevertheless, considering the high sex predictability of incisive foramen to posterior nasal spine length this dimension can definitely be used to supplement other sexing evidence available to precisely conclude the cranial sex.

Current views on temperature-modulated <i>R</i> gene-mediated plant defense responses and tradeoffs between plant growth and immunity

Venkatesh, Jelli,Kang, Byoung-Cheorl Elsevier 2019 Current opinion in plant biology Vol.50 No.-

<P>Elevated ambient temperatures will likely be a key consequence of climate change over the next few decades. Adverse climatic changes could make crop plants more vulnerable to a number of biotic and abiotic stresses, which would have a major impact on worldwide food production in the future. Recent studies have indicated that elevated temperatures directly and/or indirectly affect plant–pathogen interactions. Elevated temperatures alter multiple signal transduction pathways related to stress responses in the host plant. High temperatures can also influence plant pathogenesis, but little is known about the molecular mechanisms associated with such effects. An improved understanding of the molecular genetic mechanisms involved in plant immune responses under elevated temperatures will be essential to mitigate the adverse effects of climate change to ensure future food security. In this review, we discuss recent advances in our understanding of the effects of temperature on resistance (<I>R</I>) gene and/or regulators of <I>R</I> genes in plant defense responses and summarize current evidence for tradeoffs between plant growth and immunity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>R</I> genes are critical components of temperature-modulated defense mechanisms. </LI> <LI> PhyB and PIF4 integrate temperature and defense responses. </LI> <LI> Plant immune responses are constrained by tradeoffs with temperature-dependent growth. </LI> <LI> The temperature sensitivity of regulators of <I>R</I> genes plays an important role in modulation of plant defense. </LI> </UL> </P>

Role of ultrasound in the evaluation of first-trimester pregnancies in the acute setting

Venkatesh A. Murugan,Bryan O’Sullivan Murphy,Carolyn Dupuis,Alan Goldstein,Young H. Kim 대한초음파의학회 2020 ULTRASONOGRAPHY Vol.39 No.2

In patients presenting for an evaluation of pregnancy in the first trimester, transvaginal ultrasound is the modality of choice for establishing the presence of an intrauterine pregnancy; evaluating pregnancy viability, gestational age, and multiplicity; detecting pregnancy-related complications; and diagnosing ectopic pregnancy. In this pictorial review article, the sonographic appearance of a normal intrauterine gestation and the most common complications of pregnancy in the first trimester in the acute setting are discussed.

Creating round focused micro-jets from rectangular nozzles

Venkatesh Inguva,Rita Graceffa,Joachim Schulz,Osman Bilsel,Blair J. Perot 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.9

A focused jet is an axisymmetric jet of liquid surrounded by an outer coaxial gas jet. The gas jet is typically used to compress the liquid jet in the radial direction thereby focusing it. At microscales, it is difficult to manufacture micro-scale delivery nozzles (needles) and to consistently align and axially position the liquid and the gas needles. However, it is very easy, using standard etching technologies to make precise and repeatable rectangular nozzle designs. This work will therefore explore the geometric and fluid dynamics constraints that allow one to design rectangular nozzles that produce round coaxial micro-jets of liquid and gas. Because of the small scales, the fluid dynamics of the focusing jet is unusual, and this work demonstrates that the liquid jet is best focused by shear stretching and not via gas compression. This paper shows that sheet jetting occurs when the Reynolds number of the gas is too high. Dripping occurs when the Weber number of the liquid is too low. The desired round jet occurs by balancing Weber number of the liquid jet and Reynolds number of the gas such that surface tension at the interface holds the water jet round while the acceleration of the water jet due to shear at the interface from fast-moving air causes the liquid jet cross-sectional area to decrease. The goal of this initial paper is to demonstrate that a parameter region exists where this flow behavior is possible.

An Exhaustive Solution of Power System Unit Commitment Problem Using Enhanced Binary Salp Swarm Optimization Algorithm

Venkatesh Kumar C.,Ramesh Babu M. 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.1

The Unit Commitment (UC) problem is a combinatorial optimization problem in power system operation with the key focus on achieving optimum commitment schedule of the generators for forecasted demand and spinning reserve. The computational complexity to determine a solution for the UC problem grows exponentially with the number of generators and system constraints. In this paper, the UC problem is formulated as a mixed-integer optimization problem and solved using novel Adaptive Binary Salp Swarm Algorithm by considering minimum up/down time limits, prohibited operating zones, spinning reserve, valve-point eff ect, and ramp rate limits. The proposed algorithm is tested for effi ciency on the standard 10-unit system, 26-unit RTS system, 54-unit IEEE 118-bus system, 20, 40, 60, 80, and 100-unit systems. Additionally, an Adaptive Multi-Objective Binary Salp Swarm Optimization Algorithm is proposed for resolving the bi-objective emission constrained UC problem and tested using a 10-unit system. The obtained results are analyzed for positive diff erences against other algorithms from the literature. The statistical analysis exhibits the effi ciency of the proposed method for large scale real-time systems.

Ligand Based Pharmacophore Identification and Molecular Docking Studies for Grb2 Inhibitors

Venkatesh Arulalapperumal,Sugunadevi Sakkiah,Sundarapandian Thangapandian,이유노,Chandrasekaran Meganathan,황수완,이근우 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.5

Grb2 is an adapter protein involved in the signal transduction and cell communication. The Grb2 is responsible for initiation of kinase signaling by Ras activation which leads to the modification in transcription. Ligand based pharmacophore approach was applied to built the suitable pharmacophore model for Grb2. The best pharmacophore model was selected based on the statistical values and then validated by Fischer’s randomization method and test set. Hypo1 was selected as a best pharmacophore model based on its statistical values like high cost difference (182.22), lowest RMSD (1.273), and total cost (80.68). It contains four chemical features, one hydrogen bond acceptor (HBA), two hydrophobic (HY), and one ring aromatic (RA). Fischer’s randomization results also shows that Hypo1 have a 95% significant level. The correlation coefficient of test set was 0.97 which was close to the training set value (0.94). Thus Hypo1 was used for virtual screening to find the potent inhibitors from various chemical databases. The screened compounds were filtered by Lipinski’s rule of five, ADMET and subjected to molecular docking studies. Totally, 11 compounds were selected as a best potent leads from docking studies based on the consensus scoring function and critical interactions with the amino acids in Grb2 active site.

Enhancing fire resistance of steel bridges through composite action

Venkatesh K.R. Kodur,Augusto Gil 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.43 No.3

Bridge fire hazard has become a growing concern over the last decade due to the rapid increase of ground transportation of hazardous materials and resulting fire incidents. The lack of fire safety provisions in steel bridges can be a significant issue owing steel thermal properties that lead to fast degradation of steel properties at elevated temperatures. Alternatively, the development of composite action between steel girders and concrete decks can increase the fire resistance of steel bridges and meet fire safety requirements in some applications. This paper reviews the fire problem in steel bridges and the fire behavior of composite steel-concrete bridge girders. A numerical model is developed to trace the fire response of a typical bridge girder and is validated using measurements from fire tests. The selected bridge girder is composed by a hot rolled steel section strengthened with bearing stiffeners at midspan and supports. A concrete slab sitting on the top of the girder is connected to the slab through shear studs to provide full composite action. The validated numerical model was used to investigate the fire resistance of real scale bridge girders and the effect of the composite action under different scenarios (standard and hydrocarbon fires). Results showed that composite action can significantly increase the fire resistance of steel bridge girders. Besides, fire severity played an important role in the fire behavior of composite girders and both factors should be taken into consideration in the design of steel bridges for fire safety.