Type I Arnold Chiari Malformation with Syringomyelia and Scoliosis: Radiological Correlations between Tonsillar Descent, Syrinx Morphology and Curve Characteristics: A Retrospective Study

Shanmugasundaram Sivaraj,Viswanathan Vibhu Krishnan,Shetty Ajoy Prasad,Rai Nimish,Hajare Swapnil,Kanna Rishi Mukesh,Rajasekaran Shanmuganathan 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.1

Study Design: Retrospective cohort.Purpose: The current study was planned to evaluate deformity characteristics, assess relationship between morphology of syrinx/Arnold Chiari malformation (ACM) and deformity, analyze effect of posterior fossa decompression (PFD), and evaluate outcome.Overview of Literature: Scoliosis in ACM-I and syringomyelia (SM) is uncommon, and deformity characteristics differ from those seen in idiopathic scoliosis.Methods: Data regarding patients, who underwent PFD for ACM-I presenting with SM and scoliosis between January 2009 and December 2018, were retrospectively collected. Only patients with 2-year follow-up were included. Sagittal/coronal deformity and sagittal spinopelvic parameters were examined. Symmetry and extent of tonsillar descent, as well as morphology (configuration/variation) and extent of syrinx were determined.Results: A total of 42 patients (20 females; age: 14.2±5.8 years) were included; 35 patients (83.3%) had atypical curves. Mean preoperative coronal Cobb was 57.7°±20.9°; and 12 (28.6%) had significant coronal imbalance. Tonsillar descent was classified as grade 1, 2, and 3 in 16 (38.1%), 11 (26.2%), and 15 (35.7%) patients; 35 patients (83.3%) had asymmetric tonsillar descent; 17 (40.4%), 3 (7.1%), 16 (38.1%), and 6 (14.4%) had circumscribed, moniliform, dilated, and slender syrinx patterns; and 9 (21.4%), 12 (28.6%), and 21 (50%) of syrinx were right-sided, left-sided, and centric. There was no significant relationship between side of tonsillar dominance (<i>p</i> =0.31), grade of descent (<i>p</i> =0.30), and convexity of deformity. There was significant association between side of syrinx and convexity of scoliosis (<i>p</i> =0.01). PFD was performed in all, and deformity correction was performed in 23 patients. In curves ≤40°, PFD alone could stabilize scoliosis progression (<i>p</i> =0.02). There was significant reduction in syrinx/cord ratio following PFD (<i>p</i> <0.001).Conclusions: ACM-I+SM patients had atypical curve patterns in 83% of cases, and the side of syrinx deviation correlates with scoliosis convexity. Syrinx shrinks significantly following PFD. PFD may not stabilize scoliosis in curves >40°.

Phenothiazine based blue emitter for light-emitting electrochemical cells

Shanmugasundaram, K.,Chitumalla, R.,Jang, J.,Choe, Y. Royal Society of Chemistry 2017 New journal of chemistry Vol.41 No.18

Synthesis and photophysical characterization of an ionic fluorene derivative for blue light-emitting electrochemical cells

Shanmugasundaram, K.,Subeesh, M.S.,Sunesh, C.D.,Chitumalla, R.K.,Jang, J.,Choe, Y. Elsevier Science 2015 ORGANIC ELECTRONICS Vol.24 No.-

A highly fluorescent an ionic fluorene derivative 1 was synthesized and its photophysical, electrochemical and electroluminescence characteristics were investigated. Deep blue emissions were observed for compound 1 in solid as well as in dilute solutions. The synthesized compound shows high fluorescence quantum yield around 77% indicates that compound 1 can perform its role as efficient ionic emitter in LEC devices. Light-emitting electrochemical cell (LEC) devices were fabricated incorporating compound 1 without (device I) and with (device II) ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM.PF<SUB>6</SUB>). Devices I and II exhibited blue electroluminescence maximum centered at 455 and 454nm with CIE coordinates of (0.15, 0.21) and (0.16, 0.22), respectively. Maximum luminance and current efficiency of 1105cdm<SUP>-2</SUP> and 0.14cdA<SUP>-1</SUP> respectively, has achieved for device I while that of device II resulted in 1247cdm<SUP>-2</SUP> and 0.14cdA<SUP>-1</SUP> respectively.

Green Electroluminescence from Charged Phenothiazine Derivative

Shanmugasundaram, Kanagaraj,Subeesh, Madayanad Suresh,Sunesh, Chozhidakath Damodharan,Chitumalla, Ramesh Kumar,Jang, Joonkyung,Choe, Youngson American Chemical Society 2016 The Journal of Physical Chemistry Part C Vol.120 No.36

<P>A novel charged green-emitting organic small molecule, PPP, was synthesized and characterized by thermal, photophysical, electrochemical, and electroluminescence investigations. The theoretical properties of PPP were confirmed by means of computational studies. PPP exhibits a good thermal decomposition temperature of 355 degrees C. The compound PPP shows positive solvatochromism upon increasing the solvent polarity due to the more polarized excited state arising from the intramolecular charge transfer in the excited state. Solid-state emission of PPP was slightly red shifted compared to that of its solution emission spectrum, showing the reduced intermolecular interaction in the solid state. Solution-processed LEC devices were fabricated using PPP as a neat light-emitting layer. The fabricated single-component light-emitting electrochemical cell devices exhibited green electroluminescence centered at 530 nm with the CIE coordinates of (0.32, 0.58). Electroluminescent devices operated at very low turn-on voltages reveal a maximum luminance of 499 cd/m(2). These promising results are highly desirable for the development of low-cost lighting devices.</P>

Facile in-situ formation of rGO/ZnO nanocomposite: Photocatalytic remediation of organic pollutants under solar illumination

Shanmugasundaram, Arunkumar,Boppella, Ramireddy,Jeong, Yun-Jin,Park, Jongsung,Kim, Young-Bae,Choi, Byungchul,Park, Su Han,Jung, Seunghun,Lee, Dong-Weon Elsevier 2018 Materials chemistry and physics Vol.218 No.-

<P><B>Abstract</B></P> <P>Herein, we present a facile hydrothermal route for the preparation of hierarchical mesoporous zinc oxide (ZnO) and reduced graphene oxide-zinc oxide (ZnO<SUB>rGO</SUB>) composites for degradation of organic pollutants from natural water resources. Morphologies of the as-synthesized materials were carried out by electron microscopy in scanning and transmission modes. Thermal stability of the as-prepared products was characterised by thermogravimetric-differential thermal analysis. Crystal structure and phase purity of the materials was characterised by powder x-ray diffraction, micro-Raman, and X-ray photoelectron spectroscopy analysis. Optical properties of the as-prepared materials were investigated by ultra violet-diffused reflectance and photoluminescence spectroscopy analysis. Photocatalytic activity of the as-prepared materials was estimated by evaluating the degradation kinetics of methylene blue (MB) dye in aqueous solution under standard solar light illumination. The calculated rate constant of the Zn<SUB>rGO</SUB> is found to be ∼2.831 h<SUP>−1</SUP> which is ∼6.3 times higher than the estimated rate constant of the as-prepared pristine ZnO (0.455 h<SUP>−1</SUP>). The exceptional photocatalytic activity of the as-prepared Zn<SUB>rGO</SUB> composites is attributed to the account of their synergetic effect, porous structure, and effective separation of charge carriers. Finally, based on the obtained experimental results viable photocatalytic mechanism has been proposed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new one-step approach yields ZnO/rGO hybrids with <I>in-situ</I> formation of heterojunctions. </LI> <LI> Ethanolamine used to mineralize the ZnO precursor and also facilitates the reduction GO <I>in-situ</I>. </LI> <LI> The ZnO/rGO heterojunctions show improved photo catalytic activity under solar light illumination. </LI> <LI> Plausible photo catalysis mechanism has been proposed. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Electrochemical Properties of Nickel Oxide Nanoparticles Loaded Poly(o-toluidine) Composites

Shanmugasundaram Komathi,Pothum Selvi,Paramasivam Manisankar,Anantha Iyengar Gopalan,이광필 한국전기화학회 2011 한국전기화학회지 Vol.14 No.1

New nanocomposites, composed of poly(o-toludine) (POT) and nickel oxide nanoparticles (NiO-NPs), were prepared through oxidative polymerization of o-toludine (OT) in the presence of NiO-NPs. Films of NiO/POT were prepared with different amount of NiO-NPs (x) and different concentrations of OT (y) and designated as NiO(x)/POT(y) nanocomposites (x = amount of NiO-NPs (mg), y = concentration of OT (mM)). Field emission scanning electron microscopy images revealed that NiO-NP_s have nanorod like morphology. The two peaks, 0.39 V and 0.77V,are attributed to the redox conversion of leucoemeraldine to emeraldine and emeraldine to fully oxidized forms of POT, respectively. Electroactivity of the NiO(x)/POT(y) films showed dependence on x and y. Efficient electrocatalysts could be obtained by tuning x and y.

Direct electrochemistry of cytochrome c with three-dimensional nanoarchitectured multicomponent composite electrode and nitrite biosensing

Shanmugasundaram, K.,Sai-Anand, G.,Gopalan, A.I.,Lee, H.G.,Yeo, H.K.,Kang, S.W.,Lee, K.P. Elsevier Sequoia 2016 Sensors and actuators. B Chemical Vol.228 No.-

A novel electrochemical nitrite ion (NO<SUB>2</SUB><SUP>-</SUP>) biosensor was designed and fabricated by modifying a glassy carbon electrode (GCE) into three-dimensional nanoarchitectured electrode (3DNE) using a multicomponent nanocomposite (MCNC) film composed of graphene embedded titanium dioxide nanowires (TiO<SUB>2</SUB>(G) NWs), thiol-functionalized polyaniline (PANI(SH)), gold nanoparticles (Au), and immobilized cytochrome c (cyt c). The new NO<SUB>2</SUB><SUP>-</SUP> biosensor was designated as cyt c/TiO<SUB>2</SUB>(G) NWsΠANI(SH)-Au MCNC/3DNE. The assembly of the 3DNE, involved sequential depositions of PANI(SH) and Au over previously synthesized TiO<SUB>2</SUB>(G) NWs by electrospinning-hydrothermal processes and immobilization of the cyt c onto the TiO<SUB>2</SUB>(G) NWs/PANI(SH)/Au MCNC film. The cyt c/TiO<SUB>2</SUB>(G) NWsΠANI(SH)-Au MCNC/3DNE exhibited direct electron transfer from cyt c to the electrode at a high rate constant (25.34s<SUP>-1</SUP>). The fabricated cyt c/TiO<SUB>2</SUB>(G) NWsΠANI(SH)-Au MCNC/3DNE showed high selectivity to NO<SUB>2</SUB><SUP>-</SUP> ions with excellent sensitivity (9.2μA/mM), a wide linear concentration range (10μM-720mM), and a low detection limit (0.05μM). Additionally, the cyt c/TiO<SUB>2</SUB>(G) NWsΠANI(SH)-Au MCNC/3DNE exhibited high stability with good reproducibility and repeatability.

Electrocatalytic Reduction of CO₂ on the Dual-Atoms Anchored N6-Graphene Catalyst. A Theoretical Approach

( Shanmugasundaram Kamalakannan ),함형철 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.0

Preparation of a functional nanofibrous polymer membrane incorporated with poly(2-aminothio phenol) stabilized gold nanoparticles

Shanmugasundaram, Komathi,Subramanian, Palaniappan,Paramasivam, Manisankar,Iyengar, Gopalan Anantha,Lee, Kwang-Pill Springer-Verlag 2011 Gold bulletin Vol.44 No.1

Synthesis, Spectral and Antimicrobial Studies of Some N(2)-Substituted Tetrahydroindazoles

Shanmugasundaram Amirthaganesan,Gopalakrishnan Aridoss,Keun Soo Park,임권택,정연태 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.5

A series of N(2)-benzothiazolyl substituted tetrahydroindazoles has been synthesized via cyclic β keto esters. Optimum reaction condition was found as acidic toluene and effect of higher acidity towards substituted hydrazines in situ was described. Synthesized compounds have been achieved as single isomer and characterized by using 1D and 2D NMR spectral reports. Antimicrobial screening was carried out for the synthesized compounds along with a series of N(2)-pyridyl tetrahydroindazoles.1 The results of the in vitro antimicrobial screening studies revealed that compounds 13, 16 against Staphylococcus aureus, 11 against Escherichia coli, 10-12, 16 against Pseudomonas aeruginosa and 12 against Klebsiella pneumoniae recorded almost two-fold better activity compared to the standard drug used.