Hypouricemic and xanthine oxidase inhibitory activities of the fractions of Coccinia grandis L. Voigt

Umamaheswari, M,Chatterjee, TK Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.7 No.5

The present study was aimed at investigating the hypouricemic and xanthine oxidase inhibitory activities of the various fractions of the hydromethanolic extract of the leaves of Coccinia grandis L. Voigt (Cucurbitaceae). The leaves of this species was used in traditional medicinal system for the treatment of gout, rheumatism, jaundice, bronchitis, fever, skin eruptions, wounds, etc. The degree of xanthine oxidase inhibition was determined in vitro by measuring the increase in absorbance at 295 nm associated with uric acid formation. Among the fractions tested, the chloroform fraction exhibited highest potency ($IC_{50}$ $17.8\;{\mu}g/ml$). This was followed by the pet-ether ($IC_{50}$ $29.7\;{\mu}g/ml$), ethyl acetate ($IC_{50}$ $41.2\;{\mu}g/ml$) and residual ($IC_{50}$ $47\;{\mu}g/ml$) fractions. The $IC_{50}$ value of allopurinol was $6.1\;{\mu}g/ml$. In addition, the hypouricemic and hepatic xanthine oxidase (XO)/xanthine dehydrogenase (XDH) inhibitory activities of the fractions were examined in vivo using oxonate (280 mg/kg, i.p.) induced hyperuricemic mice. At a dose of 200 mg/kg orally for 7 days, the pet-ether, chloroform and ethyl acetate fractions produced a significant (P < 0.01) reduction in serum urate level and also inhibited hepatic XO/XDH activities when compared to hyperuricemic mice. These inhibitory effects were weaker than that observed for the standard drug, allopurinol (10 mg/kg, p.o.). Lineweaver-Burk analysis of the enzyme kinetics indicated that the mode of inhibition was of a mixed type. These results suggest that the use of Coccinia grandis leaves for the treatment of gout could be attributed to its XO inhibitory activity.

Deep eutectic solvents synthesis of perovskite type cerium aluminate embedded carbon nitride catalyst: High-sensitive amperometric platform for sensing of glucose in biological fluids

Umamaheswari Rajaji,가네시,Shen-Ming Chen,Mani Govindasamy,Sangyoun Kim,Razan A. Alshgari,시모가 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.102 No.-

In the present work, a novel method for the green synthesis of CeAlO3 (CAO) polycrystalline powderthrough deep eutectic solvents (DES) was carried out by hydrothermal method. The carbon nitride(CN) was synthesized directly by fractional thermal polymerisation process. The combination ofCeAlO3 with CN provides an excellent sensing platform for developing highly sensitive and stable electrocatalystfor non-enzymatic glucose (GLU) oxidation. The structural, morphological and electrochemicalanalysis of CeAlO3/CN (CAO/CN) shows the successful synthesis without any impurities. The synergisticeffects of pyridinic-N, pyrrolic-N and graphitic-N are highly influencing and playing a prominent role insensory performances of the prepared CAO/CN nano-electrocatalyst towards GLU sensing. The limit ofdetection (LOD) at CAO/CN modified glassy carbon electrode (CAO/CN/GCE) was calculated to be0.86 nM in the linear concentration range of 0.01–1034.5 mM by amperometric method. The antiinterference,reproducibility, repeatability and stability analysis suggest the promising performance ofthe fabricated electrode towards GLU detection. The real time application of CAO/CN/GCE was evaluatedtowards GLU sensing in human blood, saliva and sweat, a satisfactory result was obtained. Therefore, theCAO/CN/GCE has a great application prospect as a highly efficient catalyst material for highly sensitiveand efficient non-enzymatic glucose sensor.

Prediction of Temperature Distribution in the Workpiece during Multi-Pass Grinding by Finite Volume Method

Umamaheswari Madopothula,Vijayaraghavan, Lakshmanan,Ramesh Babu, Nimmagadda,Pradeev, Elango 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.11

The finite volume model is developed for multi-pass grinding by considering the grinding wheel and work contact zone as a rectangular shaped moving heat source with uniform heat distribution at a velocity equal to the feed rate. Though some literature dealt the thermal modelling of single pass grinding, in practical application multi-pass grinding is done in most of the industries to enhance the finish of work material. Modelling the temperature profile in multi-pass grinding is complex due to the heat from previous passes is carried out to the next pass. This heat accumulation from previous passes increase the peak flash temperature. Hence there is an urge to develop a thermal model which calculates the depth of heat affected zone for multi-pass grinding. The experimentally obtained grinding power is used in calculating the heat flux which replicates the condition of abrasive grains, work-wheel interaction and process behavior. For experimental validation, thermocouple is placed at a depth of 1.5mm below the grinding surface and temperature values are obtained as the material is ground till the wheel touches the thermocouple. The temperature distribution for multiple grinding passes on the work material at different depths and time, Peak temperature and the heat flux distribution. Manuscript

EXISTENCE AND STABILITY RESULTS FOR STOCHASTIC FRACTIONAL NEUTRAL DIFFERENTIAL EQUATIONS WITH GAUSSIAN NOISE AND LÉVY NOISE

P. Umamaheswari,K. Balachandran,N. Annapoorani,김대욱 경남대학교 수학교육과 2023 Nonlinear Functional Analysis and Applications Vol.28 No.2

In this paper we prove the existence and uniqueness of solution of stochastic fractional neutral differential equations with Gaussian noise or Lévy noises by using the Picar-Lindelöf successive approximation scheme. Further stability results of nonlinear stochastic fractional dynamical system with Gaussian and Lévy noises are established. Examples are provided to illustrate the theoretical results.

Enhanced ANTSEC Framework with Cluster based Cooperative Caching in Mobile Ad Hoc Networks

Subbian Umamaheswari,Govindaraju Radhamani 한국통신학회 2015 Journal of communications and networks Vol.17 No.1

In a mobile ad hoc network (MANET), communication between mobile nodes occurs without centralized control. In this environment the mobility of a node is unpredictable; this is considered as a characteristic of wireless networks. Because of faulty or malicious nodes, the network is vulnerable to routing misbehavior. The resource constrained characteristics of MANETs leads to increased query delay at the time of data access. In this paper, AntHocNet+ Security (ANTSEC) framework is proposed that includes an enhanced cooperative caching scheme embedded with artificial immune system. This framework improves security by injecting immunity into the data packets, improves the packet delivery ratio and reduces end-to-end delay using cross layer design. The issues of node failure and node malfunction are addressed in the cache management.

Direct synthesis Method ? Based Controller Design for Cold Rolling Mill

S.Umamaheswari,V.Palanisamy,M.Chidambaram 보안공학연구지원센터 2010 International Journal of Control and Automation Vol.3 No.2

Reduced-order thermal behavior of universal motor-driven domestic food mixers/grinders using AC and DC supplies

Mercy, A.,Umamaheswari, B.,Latha, K. The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.9

This paper presents an improvement in the thermal performance of universal motor, which improves the efficiency and increases the life of the motor. Excessive heating in the winding can lead to an insulation failure of a universal motor and reduce the life of a food mixer. Hence, to avoid hot spots in machine parts and obtain a homogenous temperature distribution, it is necessary to take the thermal limits into consideration. To monitor temperature increase, a lumped parameter thermal model is designed with 12 nodes for a food mixer driven by a universal motor. This paper proposes a reduced-order thermal model for a universal motor used in food mixers to monitor its thermal behavior. In this paper, a 12th-order model is reduced to a 5th-order model using a balanced truncation reduction method. The reduced-order model is validated through simulation and experimental results by comparing its response with a full-order model. A thermal analysis is carried out using AC and DC supplies along with experimentation. It can be seen that when the universal motor is operated with a DC supply, its thermal performance is improved, which increases the life of the machine. This results in energy savings, since the efficiency of the universal motor is increased when it is operated using the DC supply.

Antioxidant activities of Erythrina stricta Roxb.using various in vitro and ex vivo models

AsokKumar, K,UmaMaheswari, M,Sivashanmugam, AT,SubhadraDevi, V,Subhashini, N,Ravi, TK Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.8 No.3

Erythrina stricta, a deciduous tree widely used traditionally in indigenous system of medicine for various ailments such as rheumatism, fever, leprosy, epilepsy etc. The leaves of Erythrina stricta was extracted with ethanol (70%) and used for the evaluation of various in vitro antioxidant assays which includes H - donor activity, nitric oxide scavenging, superoxide anion scavenging, reducing ability, hydroxyl radical, hydrogen peroxide scavenging, total phenolic content, total flavonoid content, total antioxidant activity by thiocyanate and phosphomolybdenum method, metal chelating, $\beta$-carotene bleaching, total peroxy radical assays. The pro-oxidant activity was measured using bleomycin-dependent DNA damage. Ex vivo models like lipid peroxidation and erythrocyte haemolysis were also used to study the antioxidant property of the extract. The various antioxidant activities were compared with suitable standard antioxidants such as ascorbic acid, butylated hydroxyl toluene, $\alpha$-tocopherol, curcumin, quercetin and Trolox. The generation of free radicals viz. $O_2^{{\cdot}-}$, $OH^{\cdot}$, $H_2O_2$, $NO^{\cdot}$ and peroxyl radicals were effectively scavenged by the ethanolic extract of Erythrina stricta. In all the methods, the extract offered strong antioxidant activity in a concentration dependent manner. The total phenolic content, flavonoid content and total antioxidant activity in Erythrina stricta were determined as microgram (g) pyrocatechol, quercetin and $\alpha$-tocopherol equivalent/mg respectively. The extract did not exhibit any prooxidant activity when compared with ascorbic acid. The results obtained in the present study clearly indicates that Erythrina stricta scavenges free radicals and reduces lipid peroxidation, ameliorating the damage imposed by oxidative stress in different disease conditions and serve as a potential source of natural antioxidant.

Versatile midfacial degloving approach in oral and maxillofacial surgery

Anunay Pangarikar,Umamaheswari G,Prachi Parab,Suresh Kumar,Devarathnamma M,V 대한구강악안면외과학회 2019 대한구강악안면외과학회지 Vol.45 No.4

Objectives: Oral and maxillofacial surgeons must gain mastery of various approaches to the midface due to the increasing incidence, complexity, and severity of presenting midfacial fractures. Unlike in the case of other body parts, the need to preserve facial aesthetics makes it more difficult for the surgeon to select an approach for managing the facial injuries. The midfacial degloving (MFD) approach is a combination of intraoral and intranasal incisions made to access the midface without any external incision. The aim of the present study was to evaluate the efficacy of MFD in maxillofacial surgery and to assess its advantages and complications. Materials and Methods: The MFD approach was used in five cases, with three cases treated with open reduction and internal fixation and two cases operated on for posttraumatic deformity. Nasal dorsum augmentation was completed in three cases and nasal osteotomy was performed in one case. The bicoronal flap technique was combined with MFD for frontal bone augmentation in one case. The intraoperative time required for flap completion and the ease of performing the planned procedures were noted. Postoperative evaluation was done for reduction, aesthetics, function, and complications. Results: Access was excellent for performing all planned procedures. Average time spent for flap elevation and exposure of the midface was 63 minutes. Complications like postoperative swelling, infraorbital nerve paresthesia, and intranasal crusting were all transient. No long-term complications like stenosis of the nose, sneer deformity, or weakness of the facial muscles were noticed. Additionally, no complications were noted when MFD was combined with bicoronal flap. Conclusion: Though the MFD approach is technically demanding and takes more time than other facial approaches, it should be learned and applied by maxillofacial surgeons in selective cases, as it provides complete exposure of the midface without facial scarring.

Real Time Implementation of Active Power Filters for Harmonic Suppression and Reactive Power Compensation using dSPACE DS1104

Kumar, Seethapathy,Umamaheswari, B. The Korean Institute of Electrical Engineers 2008 Journal of Electrical Engineering & Technology Vol.3 No.3

In this paper, an Active Power Filter (APF) is implemented using a dSPACE DS1104 processor to compensate harmonics and reactive power produced by nonlinear load. The reference source current is computed based on the measurement of harmonics in the supply voltage and load current. A hysteresis based current controller has been implemented in a DSP processor for injecting the compensating current into the power system, so that APF allows suppression of the harmonics and reactive power component of load current, resulting in a supply current that is purely sinusoidal. Simulation and experimental results of the proposed APF to meet the IEEE-519 standards are presented.