02001nas a2200205 4500008004100000022001400041245010600055210006900161260000900230300001200239490000700251520129400258100002101552700001601573700002001589700002001609700001801629700002401647856012401671 2019 eng d a0740-322400aFiber optic Fabry-Perot interferometer sensor: an efficient and fast approach for ammonia gas sensing0 aFiber optic FabryPerot interferometer sensor an efficient and fa cMAR  a684-6890 v363 a

In this work, we propose and demonstrate a Fabry-Perot-interferometer-based polydimethylsiloxane (PDMS) and poly(methyl methacrylate) (PMMA)-composite-coated optical sensor for ammonia and volatile organic compounds (VOCs) detection at room temperature. The principle of sensing is based on change in the cavity length of the FP cavity in the presence of varied concentrations of gases, which results in changes in the total reflectance due to the shift in wavelength of an interference pattern. The sensing composite material was coated on a single-mode optical fiber by using a simple dip-coating technique and explored it for sensing. The ammonia and VOCs measurements were performed for concentrations ranging from 5 to 500 ppm. The corresponding sensitivity and limit of detection of the developed sensor for ammonia gas detection was observed of the order of around 4.16 pm/ppm and 4.8 ppm, respectively. The response and recovery times of the sensor were found to be of the order of 50 s and 10 s, respectively, for the ammonia gas. This sensor provides a simple, cost-effective, highly sensitive, and repeatable approach to measure ammonia gas and other VOCs at room temperature and could fulfill the demands of industrial applications. (C) 2019 Optical Society of America

1 aKanawade, Rajesh1 aKumar, Ajay1 aPawar, Dnyandeo1 aLate, Dattatray1 aMondal, Samir1 aSinha, Ravindra, K. uhttp://library.ncl.res.in/content/fiber-optic-fabry-perot-interferometer-sensor-efficient-and-fast-approach-ammonia-gas02230nas a2200229 4500008004100000022001400041245009600055210006900151260000900220300001400229490000700243520146300250100002201713700001601735700002001751700002101771700002001792700002001812700002401832700001801856856012601874 2019 eng d a1094-408700aNegative axicon tip-based fiber optic interferometer cavity sensor for volatile gas sensing0 aNegative axicon tipbased fiber optic interferometer cavity senso cMAR  a7277-72900 v273 a

In this research work we demonstrated negative axicon optical fiber tip filled with Polydimethylsiloxane (PDMS) as a sensor platform for volatile organic gases detection at room temperature. The response of the sensor was measured with various Volatile Organic Compounds (VOCs) such as Chloroform, Hexane, Isopropanol, Acetone, Toluene and Methanol in the concentration ranging from 5 to 200 ppm. The corresponding sensitivity and limit of detection (LOD) of the developed sensor for the measured VOCs were observed between the order of around 23.7 to 3.2 pm/ppm and 0.84 to 6.10 ppm, respectively. The response and recovery time of sensor were found between the order of 30 to 57 seconds and 8 to 25 seconds respectively for the measured VOCs. Thermal stability of the developed sensor was also studied at 30-70 degrees C with intervals of 10 degrees C. The principle of sensing is based on change in the length of the Fabry-Perot Interferometric (FPI) cavity in the presence of varied concentrations of VOCs, which results in changes in the shift in wavelength of an interference pattern attributed to the change in PDMS filling the cavity length (swelling). The experimentally observed trends in the relative swelling of PDMS with VOCs are found in agreement with the theoretically calculated values obtained from the Hansen solubility parameter (HSP). The developed gas sensor has the potential to fulfill the demands of industrial applications.

1 aKanavvade, Rajesh1 aKumar, Ajay1 aPawar, Dnyandeo1 aVairagi, Kaushal1 aLate, Dattatray1 aSarkar, Sudipta1 aSinha, Ravindra, K.1 aMondal, Samir uhttp://library.ncl.res.in/content/negative-axicon-tip-based-fiber-optic-interferometer-cavity-sensor-volatile-gas-sensing02300nas a2200253 4500008004100000020004100041245008500082210006900167260006500236520141300301653001501714653002201729653001501751653001901766653002501785100001601810700001801826700001801844700002101862700002001883700001201903700001201915856011901927 2022 eng d a978-1-5106-4740-4; 978-1-5106-4739-800aSkin mimicking solid optical tissue phantom fulfillment and its characterization0 aSkin mimicking solid optical tissue phantom fulfillment and its  a1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USAbSPIE3 a

Skin mimicking optical tissue phantoms are widely used in diagnostics systems for characterization, optimization, routine calibration and validation. In general, solid phantoms are more preferred in comparison to liquid phantoms. Therefore, our aim is to prepare and characterize the solid tissue phantoms having skin equivalent optical properties. In this work, we have used epoxy resin and hardener as a base material and titanium oxide (TiO2) nanoparticles and ink as a scatterer and absorber media, respectively. The total transmission (Tt), collimated transmission (Tc), and diffuse reflectance (Rd) spectra of the developed phantoms were measured with an integrating sphere installed in UV-VIS spectrometer within the wavelength range 400-700 nm. To characterize the optical properties such as absorption (mu(a)), reduced scattering (mu(s)'), and anisotropy factor (g) of the developed tissue phantoms, the numerical model based on Inverse Adding Doubling (IAD) has been used. With various concentrations of absorber and scatterer, a calibration curve was prepared. The calculated experimental optical properties from IAD matched with the predicted intrinsic optical properties of the skin. Thus, the preliminary results suggest that the recipe used in this study may be used as an alternative approach to developing skin mimicking solid optical phantom for diagnostics system applications.

10aAbsorption10aanisotropy factor10ascattering10askin mimicking10asolid tissue phantom1 aKumar, Ajay1 aHinge, Sarika1 aDixit, Hemant1 aKanawade, Rajesh1 aKulkarni, Gauri1 aChoi, B1 aZeng, H uhttp://library.ncl.res.in/content/skin-mimicking-solid-optical-tissue-phantom-fulfillment-and-its-characterization02607nas a2200217 4500008004100000245014200041210006900183260000800252300000700260490000600267520182300273100001802096700001602114700002102130700002002151700002302171700002102194700002302215700002302238856012802261 2023 eng d00aResponse of cardiac pulse parameters in humans at various inclinations via 360° rotating platform for simulated microgravity perspective0 aResponse of cardiac pulse parameters in humans at various inclin cJUL a540 v93 a

On the Earth, the human body is designed and adapted to function under uniform gravitational acceleration. However, exposure to microgravity or weightlessness as experienced by astronauts in space causes significant alterations in the functioning of the human cardiovascular system. Due to limitations in using real microgravity platforms, researchers opted for various ground-based microgravity analogs including head-down tilt (HDT) at fixed inclination. However, in the present study, an investigation of response of various cardiac parameters and their circulatory adaptation in 18 healthy male subjects was undertaken by using an indigenously developed 360 & DEG; rotating platform. Cardiac pulse was recorded from 0 & DEG; to 360 & DEG; in steps of 30 & DEG; inclination using piezoelectric pulse sensor (MLT1010) and associated cardiac parameters were analyzed. The results showed significant changes in the pulse shape while an interesting oscillating pattern was observed in associated cardiac parameters when rotated from 0 & DEG; to 360 & DEG;. The response of cardiac parameters became normal after returning to supine posture indicating the ability of the cardiovascular system to reversibly adapt to the postural changes. The observed changes in cardiac parameters at an inclination of 270 & DEG;, in particular, were found to be comparable with spaceflight studies. Based on the obtained results and the proposed extended version of fluid redistribution mechanism, we herewith hypothesize that the rotation of a subject to head down tilt inclination (270 & DEG;) along with other inclinations could represent a better microgravity analog for understanding the cumulative cardiac response of astronauts in space, particularly for short duration space missions.

1 aJagtap, Sagar1 aKumar, Ajay1 aMahale, Bhoopesh1 aDixit, Jyotsana1 aKalange, Ashok, E.1 aKanawade, Rajesh1 aGangal, Shashikala1 aVidyasagar, Pandit uhttp://library.ncl.res.in/content/response-cardiac-pulse-parameters-humans-various-inclinations-360%C2%B0-rotating-platform02593nas a2200349 4500008004100000022001400041245019200055210006900247260000900316300001100325490000800336520142000344653001501764653001001779653002001789653002001809653002101829653001701850100001801867700002001885700001801905700002101923700002401944700002301968700001901991700002202010700001602032700002402048700002402072700002102096856012602117 2023 eng d a0223-523400aSynthesis, biological evaluation and docking studies of silicon incorporated diarylpyrroles as MmpL3 inhibitors: an effective strategy towards development of potent anti-tubercular agents0 aSynthesis biological evaluation and docking studies of silicon i cNOV  a1156330 v2593 a

Growing global demand for new molecules to treat tuberculosis has created an urgent need to develop novel strategies to combat the menace. BM212 related compounds were found to be potent anti-TB agents and they inhibit mycolic acid transporter, MmpL3, a known potent drug target from Mycobacterium tuberculosis. In order to enhance their inhibitory potency, several silicon analogues of diarylpyrroles related to BM212 were designed, synthesized, and evaluated for anti-tubercular activities. In Alamar blue assay, most of the silicon-incorporated compounds were found to be more potent than the parent compound (BM212), against Mycobacterium tuberculosis (MIC = 1.7 & mu;M, H37Rv). Docking results from the crystal structure of MmpL3 and silicon analogues as pharmacophore model also strongly correlate with the biological assays and suggest that the incorporation of silicon in the inhibitor scaffold could enhance their potency by stabilizing the hydrophobic residues at the binding pocket. The best docking hit, compound 12 showed an MIC of 0.1 & mu;M against H37Rv with an acceptable in vitro ADME profile and excellent selectivity index. Overall, the present study indicates that, the designed silicon analogues, especially compound 12 could be a good inhibitor for an intrinsically flexible drug-binding pocket of MmpL3 and has potential for further development as anti-tubercular agents.

10aantibiotic10aBM21210adocking studies10aMmpL3 inhibitor10aSilicon analogue10atuberculosis1 aVasudevan, N.1 aMotiwala, Zenia1 aRamesh, Remya1 aWagh, Sachin, B.1 aShingare, Rahul, D.1 aKatte, Revansiddha1 aAnand, Amitesh1 aChoudhary, Sushil1 aKumar, Ajay1 aGokhale, Rajesh, S.1 aKulkarni, Kiran, A.1 aReddy, Srinivasa uhttp://library.ncl.res.in/content/synthesis-biological-evaluation-and-docking-studies-silicon-incorporated-diarylpyrroles02860nas a2200241 4500008004100000022001400041245016700055210006900222260000900291300001100300490000700311520196300318653002402281653003702305653001402342653004102356653001902397100001602416700002302432700002002455700002102475856012202496 2024 eng d a0091-328600aFabrication and evaluation of a spatially resolved fiber-optic probe for diffuse reflectance measurement for noninvasive diabetic foot ulcer diagnosis perspective0 aFabrication and evaluation of a spatially resolved fiberoptic pr cAPR  a0441030 v633 a

Timely diagnosis and monitoring of wound progression or healing are key to improving the long-term outcome of diabetic foot ulcers (DFU). Diffuse reflectance spectroscopy (DRS) has the potential to noninvasively diagnose the DFU in real time, as it detects changes in local blood volume fraction and oxygenation state level that occur when tissue becomes diseased or ulcerated. Since foot soles have a thicker epidermis and deeper blood vessels/capillaries than other parts of the body, a spatially resolved fiber-optic probe (SRFP) is needed to detect the optimal spatially resolved diffuse reflectance (SRDR) signal from the local site of the ulcer for DFU diagnosis. Therefore, herein, an SRFP consisting of a linear array of seven 400-mu m fibers with detector-source (D-S) fiber separation (rho) ranging from 0.8 to 4.8 mm was designed, fabricated, tested, and evaluated for SRDR measurement from a standard reflectance plate of barium sulfate (BaSO4) and foot sole of 27 healthy human subjects. The variation in SRDR spectra for each detector and source fiber pair measured with BaSO4 was found to be less than 1.6%. In-vivo measurements from the foot sole demonstrate that the fabricated probe has the ability to spatially resolve and distinguish the SRDR spectra from sites, namely, the fifth metatarsal, ball of great joint, calcaneum, and great toe. Experimentally and theoretically, the detector and source fiber pair of rho=1.6 and 2.4 mm were optimal for SRDR measurements from a human foot. To evaluate and validate the performance of SRFP in a context relevant to DFU diagnosis, further SRDS measurements were performed on the solid tissue phantoms that mimic the optical properties of the normal and diabetic foot sole, and their results are statistically found different. Preliminary results suggest that developed SRFP can be explored for DRS measurement from foot ulcer patients to confirm its potential clinical applicability.

10adiabetic foot ulcer10adiffuse reflectance spectroscopy10afoot sole10aspatially resolved fiber-optic probe10atissue phantom1 aKumar, Ajay1 aHattale, Gangadhar1 aPawar, Dnyandeo1 aKanawade, Rajesh uhttp://library.ncl.res.in/content/fabrication-and-evaluation-spatially-resolved-fiber-optic-probe-diffuse-reflectance00733nas a2200193 4500008004100000245012800041210006900169260000900238490000700247653002300254653001000277100001600287700002300303700001800326700002000344700002400364700002100388856013000409 2024 eng d00aNormal and diabetic foot sole skin mimicking tissue phantom fulfillment for spectroscopic-based DFU diagnostics perspective0 aNormal and diabetic foot sole skin mimicking tissue phantom fulf cJUN 0 v1410aOPTICAL-PROPERTIES10aSTATE1 aKumar, Ajay1 aHattale, Gangadhar1 aHinge, Sarika1 aKulkarni, Gauri1 aLate, Dattatray, J.1 aKanawade, Rajesh uhttp://library.ncl.res.in/content/normal-and-diabetic-foot-sole-skin-mimicking-tissue-phantom-fulfillment-spectroscopic-based