Clinico-Epidemiologic Patterns of Laryngeal Cancer: 5-year Results from a Regional Cancer Centre in Northeastern India

Nallathambi, Chandran,Yumkhaibam, Sobita Devi,Singh, Laishram Jaichand,Singh, Thaodem Tomcha,Singh, Indibor Yengkhom,Daniel, Nithinraj Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.5

Purpose: To determine the risk factors, clinical symptoms and patterns of spread in laryngeal cancer. Materials and Methods: A cross sectional study was carried out in the Regional Cancer Centre, Imphal, Manipur, India. One hundred and sixteen patients with laryngeal cancer were retrospectively reviewed for epidemiological data and descriptive statistics were reported for various variables. Results: Median age at presentation was 65 years and 32.8% were undernourished at presentation. The male to female ratio was 5.4:1. Heavy smoking and tobacco chewing was associated in 91.4% and 33.6% of patients respectively. Tracheostomy was required in 21.5% leading to diagnosis of laryngeal cancer. Almost all were squamous cell carcinoma with neuroendocrine and verrucous carcinoma accounting for less than 2%. Supraglottic, glottic and trans-glottic tumors were 56.9%, 36.3% and 6.9% respectively. Nodal metastases were seen in 81.8% of supraglottic cancers and 31.6% of glottic cancers with supraglottic involvement. Level II neck nodes were the commonest site followed by level III. Distant metastases (only liver) were apparent in 1.7% at presentation. Including these liver metastases, unresectable cases were limited to 6% of the patients. Conclusions: Tobacco use is implicated in almost all of the cases and the sex ratio has also decreased due to increased female smokers. The supraglottis remains the commonest site and incidence of nodal metastases is higher than in other countries. There is also a higher requirement for tracheostomy at presentation in this region.

Modeling and Analysis of a Multi Bossed Beam Membrane Sensor for Environmental Applications

Nallathambi Arjunan,Shanmuganantham Thangavelu 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.1

This paper presents a unique pressure sensor design for environmental applications. The design uses a newgeometry for a multi bossed beam-membrane structure with a SOI (silicon-on-insulator) substrate and a mechanicaltransducer. The Intellisuite MEMS CAD design tool was used to build and analyze the structure with FEM (finiteelement modeling). The working principle of the multi bossed beam structure is explained. FEM calculations showthat a sensing diaphragm with Mises stress can provide superior linear response compared to a stress-free diaphragm. These simulation results are validated by comparing the estimated deflection response. The results show that, thesensitivity is enhanced by using both the novel geometry and the SOI substrate.

Highly Efficient Red Emissive Heteroleptic Cyclometalated Iridium(III) Complexes Bearing Two Substituted 2-Phenylquinoxaline and One 2-Pyrazinecarboxylic Acid

Nallathambi Sengottuvelan,윤성재,김대영,황인혜,강성권,김영인 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.1

A series of highly efficient red phosphorescent heteroleptic iridium(III) complexes 1-6 containing two cyclometalating 2-(2,4-substitued phenyl)quinoxaline ligands and one chromophoric ancillary ligand were synthesized: (pqx)2Ir(mprz) (1), (dmpqx)2Ir(mprz) (2), (dfpqx)2Ir(mprz) (3), (pqx)2Ir(prz) (4), (dmpqx)2Ir(prz) (5), (dfpqx)2Ir(prz) (6), where pqx = 2-phenylquinoxaline, dfpqx = 2-(2,4-diflourophenyl)quinoxaline, dmpqx = 2-(2,4-dimethoxyphenyl)quinoxaline, prz = 2-pyrazinecarboxylate and mprz = 5-methyl-2-pyrazinecarboxylate. The absorption, emission, electrochemical and thermal properties of the complexes were evaluated for potential applications to organic light-emitting diodes (OLEDs). The structure of complex 2 was also determined by single-crystal X-ray diffraction analysis. Complex 2 exhibited distorted octahedral geometry around the iridium metal ion, for which 2-(2,4-dimethoxyphenyl)quinoxaline N atoms and C atoms of orthometalated phenyl groups are located at the mutual trans and cis-positions, respectively. The emission spectra of the complexes are governed largely by the nature of the cyclometalating ligand, and the phosphorescent peak wavelengths can be tuned from 588 to 630 nm with high quantum efficiencies of 0.64 to 0.86. Cyclic voltammetry revealed irreversible metal-centered oxidation with potentials in the range of 1.16 to 1.89 V as well as two quasi-reversible reduction waves with potentials ranging from −0.94 to −1.54 V due to the sequential addition of two electrons to the more electron-accepting heterocyclic portion of two distinctive cyclometalated C^N ligands.

Tuning Photophysical and Electrochemical Properties of Heteroleptic Cationic Iridium(III) Complexes Containing Substituted 2-Phenylquinoxaline and Biimidazole

Nallathambi Sengottuvelan,Hoe-Joo Seo,강성권,김영인 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.8

Design and syntheses of four red phosphorescent heteroleptic cationic iridium(III) complexes containing two substituted phenylquinoxaline (pqx) or benzo[b]thiophen-2-yl-pyridin (btp) main ligands and one 2,2'-biimidazole (H2biim) ancillary ligand are reported: [(pqx)2Ir(biim)]Cl (1), [(dmpqx)2Ir(biim)]Cl (2), [(dfpqx)2Ir(biim)]Cl (3),[(btp)2Ir(biim)]Cl (4). Complex 1 showed a distorted octahedral geometry around the iridium(III) metal ion with cis metallated carbons and trans nitrogen atoms. The absorption, emission and electrochemical properties were systematically evaluated. The complexes exhibited red phosphorescence in the spectral range of 580 to 620 nm with high quantum efficiencies of 0.58 - 0.78 in both solution and solid-state at room temperature depending on the cyclometalated main ligands. The cyclic voltammetry of the complexes (1-3) showed a metal-centered irreversible oxidation in the range of 1.40 to 1.90 V as well as two quasi reversible reduction waves from ‒1.15 to ‒1.45 V attributed to the sequential addition of two electrons to the more electron accepting heterocyclic portion of two distinctive cyclometalated main ligands, whereas complex 4 showed a reversible oxidation potential at 1.24 V and irreversible reduction waves at ‒1.80 V.

Modeling and Analysis of a Multi Bossed Beam Membrane Sensor for Environmental Applications

Arjunan, Nallathambi,Thangavelu, Shanmuganantham The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.1

This paper presents a unique pressure sensor design for environmental applications. The design uses a new geometry for a multi bossed beam-membrane structure with a SOI (silicon-on-insulator) substrate and a mechanical transducer. The Intellisuite MEMS CAD design tool was used to build and analyze the structure with FEM (finite element modeling). The working principle of the multi bossed beam structure is explained. FEM calculations show that a sensing diaphragm with Mises stress can provide superior linear response compared to a stress-free diaphragm. These simulation results are validated by comparing the estimated deflection response. The results show that, the sensitivity is enhanced by using both the novel geometry and the SOI substrate.

Coordination Mode of 2-Dimethylaminomethyl-3-hydroxypyridine with Nickel(II) Halides: Structural and Electrochemical Properties

Sengottuvelan, Nallathambi,Kang, Sung-Kwon,Kim, Young-Inn Korean Chemical Society 2008 Bulletin of the Korean Chemical Society Vol.29 No.9

Tuning Photophysical and Electrochemical Properties of Heteroleptic Cationic Iridium(III) Complexes Containing Substituted 2-Phenylquinoxaline and Biimidazole

Sengottuvelan, Nallathambi,Seo, Hoe-Joo,Kang, Sung-Kwon,Kim, Young-Inn Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.8

Design and syntheses of four red phosphorescent heteroleptic cationic iridium(III) complexes containing two substituted phenylquinoxaline (pqx) or benzo[b]thiophen-2-yl-pyridin (btp) main ligands and one 2,2'-biimidazole (H2biim) ancillary ligand are reported: [$(pqx)_2$Ir(biim)]Cl (1), [$(dmpqx)_2$Ir(biim)]Cl (2), [$(dfpqx)_2$Ir(biim)]Cl (3), [$(btp)_2$Ir(biim)]Cl (4). Complex 1 showed a distorted octahedral geometry around the iridium(III) metal ion with cis metallated carbons and trans nitrogen atoms. The absorption, emission and electrochemical properties were systematically evaluated. The complexes exhibited red phosphorescence in the spectral range of 580 to 620 nm with high quantum efficiencies of 0.58 - 0.78 in both solution and solid-state at room temperature depending on the cyclometalated main ligands. The cyclic voltammetry of the complexes (1-3) showed a metal-centered irreversible oxidation in the range of 1.40 to 1.90 V as well as two quasi reversible reduction waves from -1.15 to -1.45 V attributed to the sequential addition of two electrons to the more electron accepting heterocyclic portion of two distinctive cyclometalated main ligands, whereas complex 4 showed a reversible oxidation potential at 1.24 V and irreversible reduction waves at -1.80 V.

Red-Orange Emissive Cyclometalated Neutral Iridium(III) Complexes and Hydridoiridium(III) Complex Based on 2-Phenylquinoxaline : Structure, Photophysics and Reactivity of Acetylacetone Towards Cyclometalated Iridium Dimer

Sengottuvelan, Nallathambi,Yun, Seong-Jae,Kang, Sung-Kwon,Kim, Young-Inn Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.12

A new series of heteroleptic cyclometalated iridium(III) complexes has been synthesized and characterized by absorption, emission and cyclic voltammetry studies: $(pqx)_2Ir(acac)$ (1), $(dmpqx)_2Ir(acac)$ (2) and $(dfpqx)_2Ir(acac)$ (3) where pqx=2-phenylquinoxalinate, dmpqx=2-(2,4-dimethoxyphenyl)quinoxalinate, dfpqx=2-(2,4-difluorophenyl) quinoxalinate and acac=acetylacetonate anion. The reaction of excess acetylacetone with ${\mu}$-chloride-bridged dimeric iridium complex, $[(C\^N)_2Ir({\mu}-Cl)]_2$, gives a complex 1 and an unusual hydridoiridium(III) complex, $(pqx)IrH(acac)_2$ (4). The complex 1, 2 and 3 show their emissions in an orangered region (${\lambda}_{PL,max}$ = 583-616 nm), and the emission maxima can be tuned by the change of substituent at phenyl ring of 2-phenylquinoxaline ligand. The phosphorescent line shape indicates that the emissions originate predominantly from $^3MLCT$ states with little admixture of ligand-based $^3({\pi}-{\pi}^*)$ excited states. The structures of complex 3 and 4 are additionally characterized by a single crystal X-ray diffraction method. The complex 3 shows a distorted octahedral geometry around iridium(III) metal ion. A strong trans influence of the phenyl ring is examined. In complex 4, there are two discrete molecules which are mirror images each other at the ratio of 1:1 in an unit cell. We propose that the phosphorescent complex 1, 2 and 3 are possible candidates for the phosphors in OLEDs applications.

Regulation of estrous cycle by Cynodon dactylon in letrozole induced polycystic ovarian syndrome in Wistars albino rats

Anandaramajayan Nallathambi,Rajesh Bhargavan 대한해부학회 2019 Anatomy & Cell Biology Vol.52 No.4

Menstrual cycle is controlled by luteinizing hormone (LH) and follicle-stimulating hormone of anterior pituitary and regulated by gonadotropin-releasing hormone of hypothalamus. Any disturbance to this regulatory mechanism alters the pulsatile release of these hormones, especially LH; leads to polycystic ovarian syndrome (PCOS). Changes in vaginal cytology are used to interpret the changes in hormonal levels and modifications in estrous cycle. The aim of this study is to compare the pattern of vaginal cytology and body mass among PCOS rats which are treated with metformin and Cynodon dactylon. Twentyfour Wistar rats were selected and divided into four groups: control, induced, treatment, and referral. PCOS was induced in all groups except controls by giving letrozole through oral gavage for 21 days. After inducing PCOS, the referral and treatment group were treated for PCOS with metformin and C. dactylon respectively for next 21 days. Vaginal smear of all the groups were taken every day from day one and screened for estrous cycle. The body mass of the animals was measured on days 1, 21, and 42. Animals were sacrificed after 24 hours of the last dose and the reproductive organs were dissected out and weighed. Results of the study show the estrous cycle begins to revert after 1-week administration of C. dactylon; while the changes were slower in referral group. There was a rapid decrease in the body mass as well as reproductive organs among the treatment and referral group compared to that of induced and control. Finding of this study suggests that C. dactylon treats PCOS better than metformin.

Highly Efficient Red Emissive Heteroleptic Cyclometalated Iridium(III) Complexes Bearing Two Substituted 2-Phenylquinoxaline and One 2-Pyrazinecarboxylic Acid

Sengottuvelan, Nallathambi,Yun, Seong-Jae,Kim, Dae-Young,Hwang, In-Hye,Kang, Sung Kwon,Kim, Young-Inn Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.1

A series of highly efficient red phosphorescent heteroleptic iridium(III) complexes 1-6 containing two cyclometalating 2-(2,4-substitued phenyl)quinoxaline ligands and one chromophoric ancillary ligand were synthesized: (pqx)$_2Ir$(mprz) (1), (dmpqx)$_2Ir$(mprz) (2), (dfpqx)$_2Ir$(mprz) (3), (pqx)$_2Ir$(prz) (4), (dmpqx)$_2Ir$(prz) (5), (dfpqx)$_2Ir$(prz) (6), where pqx = 2-phenylquinoxaline, dfpqx = 2-(2,4-diflourophenyl)quinoxaline, dmpqx = 2-(2,4-dimethoxyphenyl)quinoxaline, prz = 2-pyrazinecarboxylate and mprz = 5-methyl-2-pyrazinecarboxylate. The absorption, emission, electrochemical and thermal properties of the complexes were evaluated for potential applications to organic light-emitting diodes (OLEDs). The structure of complex 2 was also determined by single-crystal X-ray diffraction analysis. Complex 2 exhibited distorted octahedral geometry around the iridium metal ion, for which 2-(2,4-dimethoxyphenyl)quinoxaline N atoms and C atoms of orthometalated phenyl groups are located at the mutual trans and cis-positions, respectively. The emission spectra of the complexes are governed largely by the nature of the cyclometalating ligand, and the phosphorescent peak wavelengths can be tuned from 588 to 630 nm with high quantum efficiencies of 0.64 to 0.86. Cyclic voltammetry revealed irreversible metal-centered oxidation with potentials in the range of 1.16 to 1.89 V as well as two quasi-reversible reduction waves with potentials ranging from -0.94 to -1.54 V due to the sequential addition of two electrons to the more electron-accepting heterocyclic portion of two distinctive cyclometalated C^N ligands.