Larvicidal and smoke repellency effect of Toddalia asiatica and Aegle marmelos against the dengue vector, Aedes aegypti (Insecta: Diptera: Culicidae)

Arunachalam VINEETHA,Kadarkarai MURUGAN 한국곤충학회 2009 Entomological Research Vol.39 No.1

Investigations were made to evaluate the larvicidal activity and smoke repellent potential of Toddalia asiatica (L.) and Aegle marmelos at different concentrations (20, 40, 60, 80 and 100 p.p.m.) against first to fourth instar larvae and pupae of Aedes aegypti(L.). The LC50 of A. marmelos and T. asiatica against first instars was 50.960 and 47.893 p.p.m., respectively; against second instars, 52.979 and 50.922; third instars, 56.653 and 54.461; and fourth instars, 60.778 and 61.278. The LC50 and LC90 for A. marmelos and T. asiatica against pupae were 56.634 and 112.992, and 53.64 and 116.22 p.p.m., respectively. The smoke toxicity of T. asiatica against Ae. aegypti was greater than that of A. marmelos. Smoke-exposed gravid females oviposited fewer eggs when compared to those that were not exposed to smoke. Smoke-exposed females hatched a lower percentage of eggs compared to unexposed females.

Exploring the Potential of Flunarizine for Cisplatin-Induced Painful Uremic Neuropathy in Rats

Arunachalam Muthuraman,Sumeet Kumar Singla,Anil Peters 대한배뇨장애요실금학회 2011 International Neurourology Journal Vol.15 No.3

Purpose: The present study was designed to explore the potential of flunarizine for cisplatin induced painful uremic neuropathy in rats. Methods: Cisplatin (2 mg/kg; i.p., for 5 consecutive days) was administered and renal uremic markers i.e., serum creatinine were estimated on days 4 and 25. Behavioral changes were assessed in terms of thermal hyperalgesia (hot plate, plantar, tail immersion,and tail flick tests at different time intervals). Biochemical analysis of total calcium, superoxide anion, DNA, and transketolase,and myeloperoxidase activity in tissue samples was also performed. Furthermore, flunarizine (100, 200, and 300 μM/kg; p.o., for 21 consecutive days) was administered to evaluate its potency on uremic neuropathy, and the results were compared with those for the carbamazepine-treated (30 mg/kg; p.o., for 21 consecutive days) groups. Results: Flunarizine attenuated the cisplatin-induced uremic neuropathy, and the degree of behavioral and biochemical changes in serum and tissue samples in a dose dependent manner. The medium and high doses of flunarizine were shown to produce a significant effect on cisplatin induced painful uremic neuropathy. Conclusions: Our results indicate the potential of flunarizine for anti-oxidative, anti-inflammatory, and neuroprotective actions. Therefore, it may have use as a novel therapeutic agent for the management of painful uremic neuropathy.

Unique photoelectrochemical behavior of TiO₂ nanorods wrapped with novel titanium Oxy-Nitride (TiO_xN_y) nanoparticles

Arunachalam, Maheswari,Yun, Gun,Ahn, Kwang-Soon,Seo, Won-Seon,Jung, Dae Soo,Kang, Soon Hyung Elsevier 2018 International journal of hydrogen energy Vol.43 No.34

<P><B>Abstract</B></P> <P>In this work, we developed novel titanium oxynitride (TiO<SUB>x</SUB>N<SUB>y</SUB>) nanoparticles with diameter of 25 ± 2 nm and crystalline size of ∼15 nm on hydrothermally grown one-dimensional (1D) TiO<SUB>2</SUB> nanorod (TNR) arrays. Herein, the TiO<SUB>x</SUB>N<SUB>y</SUB> nanoparticles were synthesized by facile nitridation using TiO<SUB>2</SUB> powder at 100% NH<SUB>3</SUB> gas atmosphere. Titanium oxynitride composed of potentially energetic metal-nitrogen bonds (TiN), compared to the weaker TiO bond, becomes chemically stable in the alkaline environment, and is considered as a suitable material for photoelectrochemical (PEC) system. The PEC performance of TiO<SUB>x</SUB>N<SUB>y</SUB> decorated TNR (abbreviated as TiO<SUB>x</SUB>N<SUB>y</SUB> @TNR) films was evaluated in 0.1 M KOH solution under solar illumination condition, and achieved the potentially high photocurrent density (<I>J</I>) of 2.1 mA/cm<SUP>2</SUP> at 1.23 V versus reversible hydrogen electrode (RHE) (abbreviated as V<SUB>RHE</SUB>) in the TiO<SUB>x</SUB>N<SUB>y</SUB>@TNR arrays, in comparison with the poor photoresponse (0.7 mA/cm<SUP>2</SUP> at 1.23 V<SUB>RHE</SUB>) of the pristine TNR arrays. A nearly three-fold enhancement was attained in the TiO<SUB>x</SUB>N<SUB>y</SUB> decorated TNR arrays, attributed to the high visible light absorption and fast carrier separation, due to the hybridization with the visible active TiO<SUB>x</SUB>N<SUB>y</SUB> nanoparticles in the cascading band alignment between the TiO<SUB>x</SUB>N<SUB>y</SUB> and TNR materials. Furthermore, the introduction of TiO<SUB>x</SUB>N<SUB>y</SUB> layer on the TNR surface quite reduces the interfacial resistance in the solid-liquid interface region, and further, the TiO<SUB>x</SUB>N<SUB>y</SUB> layer contributes to the passivation of the surface states (<I>e.g.,</I> defect, trap sites etc.) where the charge recombination reaction frequently happens, leading to the improvement of PEC performance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Titanium oxynitride (TiO<SUB>x</SUB>N<SUB>y</SUB>) nanoparticles on 1D TiO<SUB>2</SUB> nanorod was well developed. </LI> <LI> TiO<SUB>x</SUB>N<SUB>y</SUB> nanoparticles were synthesized by nitridation using TiO<SUB>2</SUB> powder at 100% NH<SUB>3</SUB> gas. </LI> <LI> Photocurrent density of 2.1 mA/cm<SUP>2</SUP> at 1.23 V<SUB>RHE</SUB> in the TiO<SUB>x</SUB>N<SUB>y</SUB>@TNR arrays was achieved. </LI> <LI> A three-fold enhancement was attained in the TiO<SUB>x</SUB>N<SUB>y</SUB> decorated TNR film versus TNR film. </LI> </UL> </P>

Effects of Al₂O₃ Coating on BiVO₄ and Mo-doped BiVO₄ Film for Solar Water Oxidation

Arunachalam, Maheswari,Yun, Gun,Lee, Hyo Seok,Ahn, Kwang-Soon,Heo, Jaeyeong,Kang, Soon Hyung The Korean Electrochemical Society 2019 Journal of electrochemical science and technology Vol.10 No.4

Planar BiVO₄ and 3 wt% Mo-doped BiVO₄ (abbreviated as Mo:BiVO₄) film were prepared by the facile spin-coating method on fluorine doped SnO₂(FTO) substrate in the same precursor solution including the Mo precursor in Mo:BiVO₄ film. After annealing at a high temperature of 450℃ for 30 min to improve crystallinity, the films exhibited the monoclinic crystalline phase and nanoporous architecture. Both films showed no remarkably discrepancy in crystalline or morphological properties. To investigate the effect of surface passivation exploring the Al₂O₃ layer, the ultra-thin Al₂O₃ layer with a thickness of approximately 2 nm was deposited on BiVO₄ film using the atomic layer deposition (ALD) method. No distinct morphological modification was observed for all prepared BiVO₄ and Mo:BiVO₄ films. Only slightly reduced nanopores were observed. Although both samples showed some reduction of light absorption in the visible wavelength after coating of Al₂O₃ layer, the Al₂O₃ coated BiVO₄ (Al₂O₃/BiVO₄) film exhibited enhanced photoelectrochemical performance in 0.5 M Na₂SO₄ solution (pH 6.5), having higher photocurrent density (0.91 mA/㎠ at 1.23 V vs. reversible hydrogen electrode (RHE), briefly abbreviated as V_RHE) than BiVO₄ film (0.12 mA/㎠ at 1.23 V_RHE). Moreover, Al₂O₃ coating on the Mo:BiVO₄ film exhibited more enhanced photocurrent density (1.5 mA/㎠ at 1.23 V_RHE) than the Mo:BiVO₄ film (0.86 mA/㎠ at 1.23 V_RHE). To examine the reasons, capacitance measurement and Mott-Schottky analysis were conducted, revealing that the significant degradation of capacitance value was observed in both BiVO₄ film and Al₂O₃/Mo:BiVO₄ film, probably due to degraded capacitance by surface passivation. Furthermore, the flat-band potential (V_FB) was negatively shifted to about 200 mV while the electronic conductivities were enhanced by Al₂O₃ coating in both samples, contributing to the advancement of PEC performance by ultra-thin Al₂O₃ layer.

Davallialactone protects against adriamycin-induced cardiotoxicity in vitro and in vivo.

Arunachalam, Sankarganesh,Kim, Sun Young,Lee, Sun Hwa,Lee, Young Hee,Kim, Min Sun,Yun, Bong Sik,Yi, Ho Keun,Hwang, Pyoung Han Springer-Verlag Tokyo 2012 Journal of Natural Medicines Vol.66 No.1

<P>Adriamycin (ADR) is a potent anticancer drug. Its clinical applications are limited due to its cardiotoxicity. Oxidative stress is responsible for cardiomyopathy induced by ADR. Previous studies have demonstrated that davallialactone (DAVA), extracted from mushroom Inonotus xeranticus, has potential antiplatelet aggregation activity and free radical scavenging properties. In this study, we investigated whether DAVA has protective effects against ADR-induced free radical accumulation and apoptosis in cardiac muscle cells and compared the effects of DAVA with N-acetylcysteine, a potent antioxidant. We evaluated the effect of DAVA on ADR-induced cytotoxicity by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and crystal violet staining, the reactive oxygen species (ROS) production by flow cytometry, and the expression of stress-related proteins like Cu/Zn superoxide dismutase (SOD), Mn-SOD, and the involvement of mitogen-activated protein kinase pathway by Western blot analysis. Apoptosis was assessed by nuclear condensation and the expression levels of pro-apoptotic proteins, such as caspase-3 and polyadenosine diphosphate-ribose polymerase (PARP). The cardio-protective effects of DAVA were also evaluated in an in vivo study in an animal model of ADR-induced acute cardiomyopathy. Our results showed that DAVA significantly increased the viability of doxorubicin-injured H9c2 cells and inhibited ADR-induced ROS production, apoptosis, and the expression of Cu/Zn SOD and Mn-SOD. DAVA also inhibited the expression of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), which was activated by ADR. In the in vivo animal model, treatment involving DAVA significantly reduced cardiomyocyte lesions. These results suggest that DAVA is a potentially protective agent for ADR-induced cardiotoxicity in cardiomyocytes and can be a potential candidate to protect against cardiotoxicity in ADR-treated cancer patients.</P>

Oxygen evolution NiOOH catalyst assisted V₂O₅@BiVO₄ inverse opal hetero-structure for solar water oxidation

Arunachalam, Maheswari,Ahn, Kwang-Soon,Kang, Soon Hyung Elsevier 2019 International journal of hydrogen energy Vol.44 No.10

<P><B>Abstract</B></P> <P>Using vanadium oxide (V<SUB>2</SUB>O<SUB>5</SUB>) inverse opal (IO) as a three-dimensional (3D) electron transporting tunnel, bismuth vanadate (BiVO<SUB>4</SUB>) as a light harvester, and Amorphous Nickel Hydroxide (NiOOH) as an oxygen evolution co-catalyst, a V<SUB>2</SUB>O<SUB>5</SUB>@BiVO<SUB>4</SUB>@NiOOH IO architecture was fabricated as an efficient photoanode on a conductive fluorine doped tin oxide (FTO) substrate for photoelectrochemical (PEC) water oxidation. V<SUB>2</SUB>O<SUB>5</SUB> is the visible light absorbing photoanodes for water oxidation; however, the efficiency of this compound remains low (∼0.08 mA/cm<SUP>2</SUP> at 1.23 V vs. reversible hydrogen electrode (V<SUB>RHE</SUB>)) and the unfavorable surface trap states limits the activity of V<SUB>2</SUB>O<SUB>5</SUB> photoelectrodes in a PEC system. We found that the photoactive thin conductive BiVO<SUB>4</SUB> (∼12 nm) in the V<SUB>2</SUB>O<SUB>5</SUB> IO greatly enhanced the charge separation efficiency to achieve better PEC water oxidation through modification of the surface states. The subsequent addition of NiOOH as an effective Oxygen evolution catalyst subsequently reduces the large overpotential and generates the photocurrent density of 1.14 mA/cm<SUP>2</SUP> at 1.23 V<SUB>RHE</SUB>. Electrochemical impedance spectroscopy (EIS) evidenced that NiOOH deposition can substantially lower the charge transfer resistance (R<SUB>ct</SUB>) at the semiconductor interface. Specifically, the consecutive and ordered morphology renders direct conduction pathways for the extraction of photogenerated electron/hole pairs and the convenient structure to penetrate the photogenerated carriers toward the semiconductor surface over the electrolyte. It is expected that the uninterrupted pathways will improve the electron transportation and thus the charge collection properties.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Simple synthesis method adapted to prepare V<SUB>2</SUB>O<SUB>5</SUB> IO photoanode. </LI> <LI> V<SUB>2</SUB>O<SUB>5</SUB>@BiVO<SUB>4</SUB>@NiOOH IO architecture was fabricated as photoanode for water oxidation. </LI> <LI> Thin conductive BiVO<SUB>4</SUB> (∼12 nm) in the V<SUB>2</SUB>O<SUB>5</SUB> IO enhanced the charge separation efficiency. </LI> <LI> Inverse opal morphology prompts uninterrupted pathways to improve the electron transportation. </LI> </UL> </P>

Rare earth doped CaSO₄ luminescence phosphors for applications in novel displays – new recipes

Lakshmanan, Arunachalam,Kim, Seon-Bae,Kum, Byung Gon,Jang, Hyun Myung,Kang, Bong Koo WILEY-VCH Verlag 2006 Physica status solidi. PSS. A, Applications and ma Vol.203 No.3

<P>New Recipes for rare earth doped CaSO<SUB>4</SUB> luminescence phosphors which give high photoluminescence efficiency combined with high thermal stability desired for noval display applications are described. The influence of cooling rate, thermal treatments and water washing as well as crystal size and morphology on the luminescence efficiency are described. While a modified co-precipitation technique was found best suited for preparing thermostimulated luminescence phosphors required for radiation dosimetry, those made by solid state diffusion reactions at high temperatures were found best suited to achieve the high photoluminescence efficiency required for lighting and display applications. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)</P>

염료감응형 태양전지로의 응용을 위한 얇은 TiO2가 코팅 된 WO3 역오팔 광전극의 개발

Maheswari Arunachalam,곽서의,이인호,김청수,강순형,이상권 한국재료학회 2019 한국재료학회지 Vol.29 No.8

In this study, we prepare pure WO3 inverse opal(IO) film with a thickness of approximately 3 μm by electrodeposition, and an ultra-thin TiO2 layer having a thickness of 2 nm is deposited on WO3 IO film by atomic layer deposition. Both sets of photoelectrochemical properties are evaluated after developing dye-sensitized solar cells(DSSCs). In addition, morphological, crystalline and optical properties of the developed films are evaluated through field-emission scanning electron microscopy(FE-SEM), High-resolution transmission electron microscopy(HR-TEM), X-ray diffraction(XRD) and UV/ visible/infrared spectrophotometry. In particular, pure WO3 IO based DSSCs show low VOC, JSC and fill factor of 0.25 V, 0.89 mA/cm2 and 18.9 %, achieving an efficiency of 0.04 %, whereas the TiO2/WO3 IO based DSSCs exhibit VOC, JSC and fill factor of 0.57 V, 1.18 mA/cm2 and 50.1 %, revealing an overall conversion efficiency of 0.34 %, probably attributable to the high dye adsorption and suppressed charge recombination reaction.

Fermentative Transformation of Ginsenoside Rb1 from Panax ginseng C. A. Meyer to Rg3 and Rh2 by Lactobacillus paracasei subsp. tolerans MJM60396

Sasikumar Arunachalam Palaniyandi,손병모,Karthiyaini Damodharan,서주원,양승환 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.5

Lactic acid bacteria (LAB) were screened for ginsenoside transforming activity using crude ginseng extract. Thin-layer chromatography analysis of fermented ginseng extract showed that LAB strain MJM60396 possessed higher ginsenoside transformation ability than other strains. It converted major ginsenosides into minor ginsenosides such as Rg3 and Rh2. MJM60396 also showed high β-glucosidase activity. Strain MJM60396 was identified as Lactobacillus paracasei subsp. tolerans based on 16S rRNA gene sequence. To delineate the pathway involved in the production of the minor ginsenosides Rg3 and Rh2, strain MJM60396 was incubated with pure ginsenoside Rb1. HPLC analysis revealed the appearance of Rg3 and Rh2 peak from the incubation mixture containing Rb1 and strain MJM60396. Furthermore, β-glucosidase enzyme was prepared from strain MJM60396. To achieve its maximum activity, we optimized the pH and temperature conditions. Cell-free β-glucosidase enzyme hydrolyzed ginsenoside Rb1 through the following pathway: ginsenoside Rb1 → Rd → Rg3 → Rh2. This is the first report on the transformation of ginsenosides Rb1 to Rg3 and Rh2 by a Lac. paracasei subsp. tolerans strain. Our results indicate that Lac. paracasei subsp. tolerans MJM60396 has the potential to be used for preparing ginsenosides Rg3 and Rh2 as nutraceuticals.

Foliar Application of Extract from an Azalomycin-Producing Streptomyces malaysiensis Strain MJM1968 Suppresses Yam Anthracnose Caused by Colletotrichum gloeosporioides

( Sasikumar Arunachalam Palaniyandi ),( Seung Hwan Yang ),( Joo Won Suh ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.6

Yam anthracnose caused by Colletotrichum gloeosporioides (C.g) is the most devastating disease of yam (Dioscorea sp.). In the present study, we evaluated the culture filtrate extract (CFE) of azalomycin-producing Streptomyces malaysiensis strain MJM1968 for the control of yam anthracnose. MJM1968 showed strong antagonistic activity against C.g in vitro. Furthermore, the MJM1968 CFE was tested for inhibition of spore germination in C.g, where it completely inhibited spore germination at a concentration of 50 μg/ml. To assess the in planta efficacy of the CFE and spores of MJM1968 against C.g, a detached leaf bioassay was conducted, which showed both the treatments suppressed anthracnose development on detached yam leaves. Furthermore, a greenhouse study was conducted to evaluate the CFE from MJM1968 as a fungicide for the control of yam anthracnose. The CFE non-treated plants showed a disease severity of >92% after 90 days of artificial inoculation with C.g, whereas the disease severity of CFE-treated and benomyl-treated yam plants was reduced to 26% and 15%, respectively, after 90 days. Analysis of the yam tubers from the CFE-treated and non-treated groups showed that tubers from the CFE-treated plants were larger than that of non-treated plants, which produced abnormal smaller tubers typical of anthracnose. This study demonstrated the utility of the CFE from S. malaysiensis strain MJM1968 as a biofungicide for the control of yam anthracnose.