Folded Architecture for Digital Gammatone Filter Used in Speech Processor of Cochlear Implant

Rajalakshmi Karuppuswamy,Kandaswamy Arumugam,Swathi Priya M 한국전자통신연구원 2013 ETRI Journal Vol.35 No.4

Emerging trends in the area of digital very large scale integration (VLSI) signal processing can lead to a reduction in the cost of the cochlear implant. Digital signal processing algorithms are repetitively used in speech processors for filtering and encoding operations. The critical paths in these algorithms limit the performance of the speech processors. These algorithms must be transformed to accommodate processors designed to be high speed and have less area and low power. This can be realized by basing the design of the auditory filter banks for the processors on digital VLSI signal processing concepts. By applying a folding algorithm to the second-order digital gammatone filter (GTF), the number of multipliers is reduced from five to one and the number of adders is reduced from three to one, without changing the characteristics of the filter. Folded second-order filter sections are cascaded with three similar structures to realize the eighth-order digital GTF whose response is a close match to the human cochlea response. The silicon area is reduced from twenty to four multipliers and from twelve to four adders by using the folding architecture.

Biocompatible silica nanoparticles conjugated with azidocoumarin for trace level detection and visualization of endogenous H₂S in PC3 cells

Rajalakshmi, Kanagaraj,Nam, Yun-Sik,Youg, Sumin,Selvaraj, Muthusamy,Lee, Kang-Bong Elsevier 2018 Sensors and actuators. B Chemical Vol.259 No.-

<P><B>Abstract</B></P> <P>The silica nanoparticles (SiO<SUB>2</SUB>NPs) conjugated with azidocoumarin (Cy-N<SUB>3</SUB>) was applied for the selective and sensitive H<SUB>2</SUB>S detection, even when H<SUB>2</SUB>S was present in 1000-fold excess of other bio thiols and ions. In the silica nanoprobes, azide in the Cy-N<SUB>3</SUB> group acted as the recognition element, and the probe was biocompatible. The nanoprobe displayed blue emission at 456 nm and excitation at 367 nm. After introducing H<SUB>2</SUB>S into the probe solution, the fluorescent intensity at 456 nm increased linearly as a function of H<SUB>2</SUB>S concentration (correlation coefficient, 0.9970), and the limit of detection was 6 nM. The enhanced fluorescent emission intensity was due to H<SUB>2</SUB>S-mediated reduction of the electron-withdrawing azide into electron-donating amine. The SiO<SUB>2</SUB>NPs@Cy-N<SUB>3</SUB> and its reaction products with H<SUB>2</SUB>S (SiO<SUB>2</SUB>NPs@Cy-NH<SUB>2</SUB>) were characterized by <SUP>1</SUP>H NMR and TEM. The probe also showed low cytotoxicity and could trace endogenous H<SUB>2</SUB>S in physiological pH. We therefore then successfully utilized it to detect H<SUB>2</SUB>S in living PC3 cells. The probe was also successfully employed for detection of H<SUB>2</SUB>S gas using Whatman papers coated with SiO<SUB>2</SUB>NPs@Cy-N<SUB>3</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biocompatible chemosensor for H<SUB>2</SUB>S detection was developed using silica nanoparticles. </LI> <LI> H<SUB>2</SUB>S detection was achieved even in 1000-fold excess of other interferents. </LI> <LI> The lowest LOD was 6 nM under physiological conditions. </LI> <LI> The probe was successfully applied for H<SUB>2</SUB>S detection in live PC3 cells. </LI> <LI> The paper strip probe coated with silica nanoparticles successfully detected H<SUB>2</SUB>S. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Preparedness of Siddha system of medicine in practitioner perspective during a pandemic outbreak with special reference to COVID-19

Rajalakshmi, S.,Samraj, K.,Sathiyarajeswaran, P.,Kanagavalli, K. Cellmed Orthocellular Medicine and Pharmaceutical 2020 셀메드 (CellMed) Vol.10 No.4

COVID-19 (Corona Virus Disease-2019) is an infectious respiratory disease caused by the most recently discovered coronavirus, SARS-CoV-2 (Severe Acute Respiratory Syndrome Corona virus-2). This new viral disease was unknown before the outbreak began in Wuhan, China, in December 2019. As of November 16th 2020, it affects about 54.3 million populations, death troll increased to 1.32 million cases in worldwide. Whereas in India 8.85 cases are infected with COVID-19, of which 1, 30, 112 cases were died. Till now there has been no specific anti-virus drug or vaccines are available for the treatment of this disease, the supportive care and non-specific treatment to the symptoms of the patient are the only options in Biomedicine, the entire world turns its attention towards alternative medicine or Traditional medicine. Siddha medicine is one of the primordial systems of medicine practiced in the southern part of India, it dealt a lot about pandemic, and its management. This review provides an insight into Pandemic in Siddha system and its management in both ancient history and modern history, National and state level Government policies related to current pandemic, World Health Organization (WHO) guidelines on usage of unproven drug during infectious disease outbreak, Preparedness of Siddha system during a pandemic outbreak Challenges and Recommendations.

Metal free bioimaging reagent for intracellular citrate in prostate cancer cells using aryl boronate derivative

Rajalakshmi, Kanagaraj,Nam, Yun-Sik,Selvaraj, Muthusamy,Lee, Yeonhee,Lee, Kang-Bong Elsevier 2018 Sensors and actuators. B Chemical Vol.259 No.-

<P><B>Abstract</B></P> <P>A boronate group integrated on a triphenylimidazoleoxadiazolephenyl (TPIOP) moiety exhibited unusual sensing and detection abilities towards citrate. TPIOP boronate exhibited a bathochromic shift in its fluorescence emission upon interaction with citrate. Quantification of trace levels of citrate ions in the human body may aid in the diagnosis of prostate cancer and kidney malfunctions. Herein, a novel, metal-free sensing strategy for citrate was developed based on fluorimetric detection with TPIOP boronate. The fluorescence of TPIOP boronate increased linearly and was gradually red-shifted upon addition of citrate. The enhanced emission intensity was attributed to aggregation induced emission. The vacant ‘p’ orbital of boron in TPIOP boronate acts as a Lewis acid, and accepts electrons from citrate, which is a Lewis base. Upon binding, the hybridization geometry of boron changes from sp<SUP>2</SUP> trigonal planar to sp<SUP>3</SUP> tetrahedral. The TPIOP boronate-citrate aggregates increase the polarity of TPIOP-boronate, which caused the red shift in the fluorescence. Citrate could be detected visually using a UV lamp, as the probe changed from blue to green upon interaction with the analyte. The developed probe was applied for the visualization of endogenous citrate in PC3 live cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel boronate derivative was designed and synthesized for use as a metal-free citrate sensor. </LI> <LI> The sensor changes color from blue to green in the presence of citrate. </LI> <LI> Sensor showed 500-fold selectivity over other carboxylates, and the LOD was 10 nM. </LI> <LI> This probe showed low cytotoxicity and can be utilized for the detection of citrate in live PC3 cells. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Hopf-bifurcation Analysis of a Delayed Model for the Treatment of Cancer using Virotherapy

Rajalakshmi, Maharajan,Ghosh, Mini Department of Mathematics 2022 Kyungpook mathematical journal Vol.62 No.1

Virotherapy is an effective method for the treatment of cancer. The oncolytic virus specifically infects the lyse cancer cell without harming normal cells. There is a time delay between the time of interaction of the virus with the tumor cells and the time when the tumor cells become infectious and produce new virus particles. Several types of viruses are used in virotherapy and the delay varies with the type of virus. This delay can play an important role in the success of virotherapy. Our present study is to explore the impact of this delay in cancer virotherapy through a mathematical model based on delay differential equations. The partial success of virotherapy is guarenteed when one gets a stable non-trivial equilibrium with a low level of tumor cells. There exits Hopf-bifurcation by considering the delay as bifurcation parameter. We have estimated the length of delay which preserves the stability of the non-trivial equilibrium point. So when the delay is less than a threshold value, we can predict partial success of virotherapy for suitable sets of parameters. Here numerical simulations are also performed to support the analytical findings.

Highly selective and sensitive detection of Cr⁶⁺ ions using size-specific label-free gold nanoparticles

Kanagaraj, Rajalakshmi,Nam, Yun-Sik,Pai, Sung Jin,Han, Sang Soo,Lee, Kang-Bong Elsevier 2017 Sensors and actuators. B Chemical Vol.251 No.-

<P><B>Abstract</B></P> <P>Gold nanoparticles (AuNPs) of various sizes were synthesized by modifying the citrate concentration; 45nm AuNPs were found to respond to Cr<SUP>6+</SUP> ions selectively. Label-free AuNPs, 45nm, showed localized surface plasmon resonance bands at 530nm, which decreased linearly upon addition of Cr<SUP>6+</SUP>. The addition of Cr<SUP>6+</SUP> also resulted in the appearance of a new band at 750nm, along with a visible color change in the solution from wine red to violet. The decrease in absorbance and color change were due to AuNP aggregation upon coordination of Cr<SUP>6+</SUP>. The detection limit for Cr<SUP>6+</SUP> was 0.4nM, and excellent selectivity was observed in the presence of other metal ions and anions. The binding site and sensing mechanism for Cr<SUP>6+</SUP> and label-free AuNPs were characterized by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. This method was applied to tap, pond, and waste water samples, and validated using inductively coupled plasma-optical emission spectrometry, illustrating the utility of the sensitive, selective, and simple AuNP sensor in the detection of Cr<SUP>6+</SUP>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Color change is induced by size-specific Au nanoparticles aggregation in the presence of Cr<SUP>6+</SUP> ions. </LI> <LI> A newly developed assay method uses 45nm label-free Au nanoparticles for detection of Cr<SUP>6+</SUP>ions. </LI> <LI> The sensor exhibits excellent selectivity for Cr<SUP>6+</SUP>ions over other metal cations and anions. </LI> <LI> The present assay method can detect a Cr<SUP>6+</SUP>ionic concentration of ∼ 0.4nM within 70min. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Manju</P> <P>[DISPLAY OMISSION]</P>

ON SOFT ROUGH PRE OPEN SETS IN SOFT ROUGH TOPOLOGICAL SPACES

J. Rajalakshmi,Dr. R. Selvi 충청수학회 2022 충청수학회지 Vol.35 No.2

The notions of soft rough pre open set, soft rough pre closed set, soft rough dense set, soft rough sub maximal, soft rough pre interior and soft rough pre closure are introduced and studied. We also investigate some related properties of these concepts.

Biochar Characterization and Evaluation for their Application as a Soil Amendments

Krishnakumar Srinivasagam,Rajalakshmi Anaimalai Gopalakr,Manikandan Angamuthu,Vinoth Chelladurai 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

On-off-on relay fluorescence recognition of ferric and fluoride ions based on indicator displacement in living cells

Selvaraj, Muthusamy,Rajalakshmi, Kanagaraj,Nam, Yun-Sik,Lee, Yeonhee,Song, Jong-Won,Lee, Ho-Jin,Lee, Kang-Bong Elsevier 2019 Analytica Chimica Acta Vol.1066 No.-

<P><B>Abstract</B></P> <P>A new boronic acid derivative functionalized with a 4-(3-(4-(4,5-diphenyl-1H-imidazole-2-yl)phenyl)-1,2,4-oxadiazol-5-yl)phenyl (IOP) moiety was synthesized for use as a sequential “on-off-on”-type relay fluorescence probe for Fe<SUP>3+</SUP> ions and F<SUP>−</SUP> ions with high selectivity and sensitivity under physiological conditions. The introduction of Fe<SUP>3+</SUP> to IOP boronic acid (IOPBA) formed an Fe<SUP>3+</SUP> IOPBA complex, which led to quenching of the blue fluorescence intensity at 458 nm. The lowest-energy conformation of IOPBA was theoretically predicted to adopt an extended structure, and the Fe<SUP>3+</SUP> ion in the Fe<SUP>3+</SUP> IOPBA complex was coordinated to two phenyl groups to form a π-complex. Upon addition of F<SUP>−</SUP> to the Fe<SUP>3+</SUP> IOPBA complex, the original fluorescence was recovered due to formation of [FeF<SUB>6</SUB>]<SUP>3‒</SUP>, resulting in “on-off-on”-type sensor behavior. IOPBA showed high selectivity towards Fe<SUP>3+</SUP> among other cations. Moreover, the Fe<SUP>3+</SUP> IOPBA complex showed specific selectivity towards F<SUP>−</SUP>, with other cations and anions not interfering with detection. Both sensing processes showed 1:1 stoichiometry with binding constants of 6.87 × 10<SUP>6</SUP> and 4.49 × 10<SUP>6</SUP> mol<SUP>−1</SUP> L for Fe<SUP>3+</SUP> with IOPBA and F<SUP>−</SUP> with Fe<SUP>3+</SUP> IOPBA, respectively. The limits of detection for Fe<SUP>3+</SUP> and F<SUP>−</SUP> were 10 and 1 nM, respectively. The proposed method was successfully applied in real water samples. Furthermore, the probe had low cytotoxicity and was successfully used as a bioimaging reagent to detect intracellular Fe<SUP>3+</SUP> and F<SUP>−</SUP> in living HeLa cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Imidazole oxadiazole boronic acid derivative (IOPBA) was designed and synthesized. </LI> <LI> IOPBA showed highly sensitive and selective response for Fe<SUP>3+</SUP> and F<SUP> <B>−</B> </SUP>. </LI> <LI> On-off-on type relay response was achieved at Fe<SUP>3+</SUP> IOPBA with F<SUP> <B>−</B> </SUP>. </LI> <LI> The probe expressed LODs of 10 and 1 nM for Fe<SUP>3+</SUP> and F<SUP>−</SUP>, respectively. </LI> <LI> IOPBA can be utilized as bioimaging reagent for Fe<SUP>3+</SUP> and F<SUP>−</SUP> in living HeLa cells. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Rapid-Response and Highly Sensitive Boronate Derivative-Based Fluorescence Probe for Detecting H ₂ O ₂ in Living Cells

Selvaraj, Muthusamy,Rajalakshmi, Kanagaraj,Nam, Yun-Sik,Lee, Yeonhee,Kim, Byoung Chan,Pai, Sung Jin,Han, Sang Soo,Lee, Kang-Bong Hindawi 2019 Journal of analytical methods in chemistry Vol.2019 No.-

<P>Intracellular H<SUB>2</SUB>O<SUB>2</SUB> monitoring is important and has driven researchers to pursue advancements for the rapid identification of H<SUB>2</SUB>O<SUB>2</SUB>, since H<SUB>2</SUB>O<SUB>2</SUB> is short-lived in cell lines. An arylboronate derivative has been investigated as a chemospecific fluorescence recognition agent for H<SUB>2</SUB>O<SUB>2</SUB>. Triphenylimidazoleoxadiazolephenyl (TPIOP) boronate was contrived as a novel candidate for the rapid and sensitive recognition of H<SUB>2</SUB>O<SUB>2</SUB>. The probe was conjugated using the TPIOP functional group acting as an excellent fluorescent enhancer. The TPIOP group stimulated the polarization of C–B bond due to its extended <I>π</I>-conjugation, which included heteroatoms, and induced the production of rapid signal because of the highly polar C–B bond along with the corresponding boronate unit. While H<SUB>2</SUB>O<SUB>2</SUB> reacts with TPIOP boronate, its nucleophilic addition to the boron generates a charged tetrahedral boronate complex, and then the C–B bond migrates toward one of the electrophilic peroxide oxygen atoms. The resulting boronate ester is then hydrolyzed by water into a phenol, which significantly enhances fluorescence through aggregation-induced emission. The TPIOP boronate probe responded to H<SUB>2</SUB>O<SUB>2</SUB> rapidly, within 2 min, and exhibited high sensitivity with a limit of detection of 8 nM and a 1000-fold selectivity in the presence of other reactive oxygen species. Therefore, the developed TPIOP boronate chemodosimeter was successfully utilized to visualize and quantify intracellular H<SUB>2</SUB>O<SUB>2</SUB> from human breast cancer (MCF-7) cells, as well as gaseous and aqueous H<SUB>2</SUB>O<SUB>2</SUB> from environmental samples using Whatman paper strips coated with TPIOP boronate.</P>