Effect of cyclodextrin glucanotransferase enzyme in biodegradation of diesel oil

Sivaraman, C.,Ganguly, Anasuya,Mutnuri, Srikanth Techno-Press 2012 Advances in environmental research Vol.1 No.2

Microbial degradation of hydrocarbons is found to be an attractive process for remediation of contaminated habitats. However the poor bioavailability of hydrocarbons results in low biodegradation rates. Cyclodextrins are known to increase the bioavailability of variety of hydrophobic compounds. In the present work we purified the Cyclodextrin Glucanotransferase (CGTase) enzyme which is responsible for converting starch into cyclodextrins and studied its role on biodegradation of diesel oil contaminated soil. Purification of CGTase from Enterobacter cloacae was done which resulted in 6 fold increase in enzyme activity. The enzyme showed maximum activity at pH 7, temperature $60^{\circ}C$ with a molecular weight of 66 kDa. Addition of purified CGTase to the treatment setup with Pseudomonas mendocina showed enhanced biodegradation of diesel oil ($57{\pm}1.37%$) which was similar to the treatment setup when added with Pseudomonas mendocina and Enterobacter cloacae ($52.7{\pm}6.51%$). The residual diesel oil found in treatment setup added with Pseudomonas mendocina at end of the study was found to be $73{\pm}0.21%$. Immobilization of Pseudomonas mendocina on alginate containing starch also led to enhanced biodegradation of hydrocarbons in diesel oil at 336 hours.

Triphenylamine and Benzothiadiazole-Based D-A-A’ and A’-A-D-D-A-A’ Type Small Molecules for Solution-Processed Organic Solar Cells

Sivaraman Somasundaram,전수지,박상혁 한국고분자학회 2016 Macromolecular Research Vol.24 No.3

Utilization of small-molecule based organic photovoltaic (OPV) devices has received strong attention due to their easy preparation, purification, and batch-to-batch resemblance in properties. In this work, a series of simple benzothiadiazole and triphenylamine-containing molecules were synthesized, and their application to organic photovoltaic devices was investigated. The absorption spectra demonstrated that the absorption wavelength of the small molecules could be tuned dramatically by extension of molecular structure from donor-acceptor-acceptor (D-A-A’) to A’-A-D-D-A-A’ sequences. Due to the intramolecular energy transfer from the acceptor to donor and vice versa in D-A-A’ structures in prepared molecules, the maximum emission wavelengths were red-shifted gradually with the increase of chain length. Bulk heterojunction (BHJ) type solar cell devices were fabricated by using the small molecules as donors and (6,6)-phenyl C61-butyric acid methyl ester (PC61BM) as acceptor (2:1), gave maximal open circuit voltage of the photovoltaic cells of 0.59 V and the power conversion efficiencies of the devices were measured 0.83% under AM 1.5G irradiation (100 mWcm-2).

A protecting group-free divergent synthesis of natural benzofurans <i>via</i> one-pot synthesis of 2-bromo-6-hydroxybenzofurans

Sivaraman, Aneesh,Harmalkar, Dipesh S.,Kang, Jiyoon,Choi, Yongseok,Lee, Kyeong The Royal Society of Chemistry 2019 Organic & Biomolecular Chemistry Vol.17 No.8

<P>2-Bromo-6-hydroxybenzofurans are potentially versatile intermediates for the divergent synthesis of numerous benzofuran-based natural products and their analogues. Herein we report the first one-pot strategy for the efficient synthesis of 2-bromo-6-hydroxybenzofurans. The present protocol provides shorter routes for the synthesis of moracins M, N, O and P; gramniphenols F and G; and morunigrol C using a protecting group-free approach.</P>

TPB Based Imidazoles as Hole Transporting Materials for Efficient Perovskite Solar Cells

Somasundaram Sivaraman,박상혁 한국고분자학회 2018 한국고분자학회 학술대회 연구논문 초록집 Vol.43 No.1

Performance and evaluation of MoS2 based machining using PVD-TiAlN coated tool

Viswanathan Sivaraman,Subramanian Prakash 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.9

A recent trend on turning of difficult-to-machine (DTM) materials using environmentally friendly vegetable oil has became popular due to its immense machinability aids. Conventional cutting oils fail to give cooling/lubrication at higher cutting speed-feed combination and create environmental pollution. The present work investigated the effect of molybdenum disulphide nanoparticle (nMoS 2 ) dispersed in castor oil, as a cutting fluid, sprayed using minimum quantity lubrication (MQL) technique on turning of AISI O1 cold worked tool steel. The machining was carried out by varying the speed ranging from 110-170 m/min, a feed rate of 0.02-0.08 mm/rev and depth of cut of 0.7 mm. PVD-TiAlN coated tungsten carbide insert was used for the experimentation. The experimental results of nMQL condition were compared with the dry and wet condition. The results proved that application nMQL has given 15-49 % enhanced tool life with better surface finish as compared with dry and wet condition, respectively. No major phase change occurs in nMQL when compared with other conditions because of their low cutting temperature.

Outcomes of salvage radical prostatectomy following more than one failed local therapy

Arjun Sivaraman,Peter Scardino,James Eastham 대한비뇨의학회 2018 Investigative and Clinical Urology Vol.59 No.3

Purpose: To describe the salvage radical prostatectomy (sRP) experience in patients presenting with recurrent, clinically localized prostate cancer after multiple failed local treatments. Materials and Methods: Among the 251 sRP performed during 2000–2016, 11 patients had failed multiple local therapies. We describe baseline clinical characteristics at primary cancer diagnosis and prior to sRP, surgical information, complications and oncological outcomes. Results: The mean±standard deviation age at sRP was 65±5 years and the median (interquartile range) serum prostate-specific antigen (PSA) level was 2 (1.3) ng/mL. The most common first and subsequent treatments were radiotherapy and cryotherapy, respectively, with median time of 24 months from the last local treatment. The median operative time was 180 minutes and median estimated blood loss was 750 mL. Five (45.5%) patients underwent additional procedures during sRP for pre-operative morbidity from prior treatments (rectourethral fistula, urethral stricture, incontinence). Post-operative complications requiring invasive intervention occurred in 7 (63.6%) patients. Over a median follow-up of 29 (12–96) months, 10 of the 11 men (90.9%) achieved an undetectable PSA in after sRP. Three of these men with an initially undetectable PSA level experienced biochemical recurrence; the remaining 7 are without evidence of disease. Overall, no local recurrence or systemic metastasis was identified at last follow-up. Conclusions: sRP is technically feasible and offers durable cancer control in patients with recurrent prostate cancer despite having undergone multiple prior attempts at cure. These patients experience higher rates of post-operative complications and such patients must be appropriately counseled regarding the potential risks and benefits.

Antioxidant Activities of Squid Protein Hydrolysates Prepared with Papain Using Response Surface Methodology

Balasubramanian Sivaraman,Robinson Jeya Shakila,Geevaretnam Jeyasekaran,Durairaj Sukumar,Uthaman Manimaran,Ganesan Sumathi 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.3

Squid protein hydrolysates (SPH) were prepared from the Indian squid Loligo duvauceli using papain. Response surface methodology (RSM) was used for optimization of hydrolysis conditions, including temperature, time, and the enzyme-substrate ratio using DPPH radical scavenging activity as a response. The amino acid composition of SPH was compared with raw squid muscle. In vitro antioxidant activities were evaluated based on reducing power, metal chelation, ABTS, hydroxyl radical, and superoxide anion radical scavenging assays. SPH exhibited good ABTS radical scavenging activities of 96.50±0.90%, superoxide anion radical scavenging activities of 96.4±0.89%, reducing powers of 0.71±0.02, moderate hydroxyl radical scavenging activities of 64.03±2.11%, and metal chelating activities of 52.04±1.02%. In vivo antioxidant activities determined using a sardine minced model system showed 42% reduction in formation of secondary oxidative products as thiobarbituric acid reactive substances (TBARS), almost equivalent to reduction by ascorbic acid of 41.42% at 400 ppm.

Can pelvic node dissection at radical prostatectomy influence the nodal recurrence at salvage lymphadenectomy for prostate cancer?

Arjun Sivaraman,Nicole Benfante,Karim Touijer,Jonathan Coleman,Peter Scardino,Vincent Laudone,James Eastham 대한비뇨의학회 2018 Investigative and Clinical Urology Vol.59 No.3

Purpose: To verify the quality of pelvic lymph node dissection (PLND) performed at radical prostatectomy (RP) and its impact on nodal recurrence in patients undergoing salvage lymph node dissection (sLND). Materials and Methods: Retrospective review of 48 patients who underwent sLND for presumed nodal recurrence, to describe the PLND characteristics at RP and correlate the anatomical sites and number of suspicious nodes reported in radiological imaging and final pathology of sLND. Results: Overall, at RP, 8 (16.7%) did not undergo PLND, 32 (66.7%) and 8 (16.7%) received a “limited” (between external iliac vein and obturator nerve) and an “extended” (external iliac, hypogastric, and obturator) dissection, respectively. Median nodes removed during limited and extended dissection were 2 and 24, respectively. At sLND, the mean age was 61.3 years and median prostate specific antigen (PSA) was 1.07 ng/mL. Median nodes removed at sLND were 17 with a median of 2 positive nodes. Recurrent nodes were identified within the template of an extended PLND in 62.5%, 50.0% and 12.5% patients, respectively, following prior no, limited and extended dissection at RP. Recurrence outside the expected lymphatic drainage pathway was noted in 37.5% patients with prior extended dissection at RP. There was a correlation between imaging and pathology specimen in 83% for node location and 58.3% for number of anatomical sites involved. Conclusions: In prostate cancer patients undergoing sLND, most had inadequate PLND at the original RP. Pattern of nodal recurrence may be influenced by the prior dissection and pre sLND imaging appears to underestimate the nodal recurrence.

Design and Analysis of Two Stage Model for Effective Beam forming using MATLAB and VerilogHDL

Devi Sivaraman,Ajith Kumar P.C,Sundaramoorthy T,Neeraj Kr. Shukla 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.4

Beam forming is a technique in signal processing that has found widespread applications in fields such as radar, wireless communication, bio-medical ultrasounds and so on. Beam forming consist of an array of antennas whose radiation pattern are adjusted to a particular direction. This paper aims in implementing a two stage design for acoustic beam forming using MATLAB and Verilog HDL. First stage is a delay and sum beam former used to obtain beams from a particular direction while the second stage is an LMS model based on Least Mean Square (LMS) algorithm. This stage improves the efficiency of delay sum by removing the unwanted signals. Different hardware parameters like logic utilization, memory usage, CPU time and delay of this design are analyzed to determine its characteristics as compared to delay sum and LMS. This study found that the two stage model gives better beam forming and noise removal than when the stages are implemented independently.

Role of Electron Withdrawing Groups in Phenoxazine-Oxadiazole Based D-A Molecules Towards Enriching TADF Emission

Somasundaram Sivaraman,박상혁,강현구 한국고분자학회 2023 한국고분자학회 학술대회 연구논문 초록집 Vol.48 No.2