The passage of heavy ions in a track detector polymeric material produces lattice deformations. T... more The passage of heavy ions in a track detector polymeric material produces lattice deformations. These deformations may be in the form of latent tracks or may vanish by self annealing in time. Heavy ion irradiation produces modifications in polymers in their relevant electrical, chemical and optical properties in the form of rearrangement of bonding, cross-linking, chain scission, formation of carbon rich clusters and changes in dielectric properties etc. Modification depends on the ion, its energy and fluence and the polymeric material. In the present work, a study of the dielectric response of pristine and heavy ion irradiated Makrofol-KG polycarbonate is carried out. 40 μm thick Makrofol-KG polycarbonate films were irradiated to various fluences with Si 8+ ions of 100 MeV energy from Pelletron at Inter University Accelerator Centre (IUAC), New Delhi and Ne 6+ ions of 145 MeV from Variable Energy Cyclotron Centre, Kolkata. On irradiation with heavy ions dielectric constant ( ) decreases with frequency where increases with fluence for both the ions. Variation of loss factor (tan ) with frequency for pristine and irradiated with Si ions reveals that tan increases as the frequency increases. Tan also increases with fluence. While Ne irradiated samples tan shows slight variation with frequency as well as with fluence. Tan has positive values indicating the dominance of inductive behavior.
This paper describes an ongoing project to develop a computer-integrated system to assist surgeon... more This paper describes an ongoing project to develop a computer-integrated system to assist surgeons in revision total hip replacement (RTHR) surgery. In RTHR surgery, a failing orthopedic hip implant, typically cemented, is replaced with a new one by removing the old implant, removing the cement and fitting a new implant into an enlarged canal broached in the femur. RTHR surgery is a difficult procedure fraught with technical challenges and a high incidence of complications. The goals of the computer-based system are the significant reduction of cement removal labor and time, the elimination of cortical wall penetration and femur fracture, the improved positioning and fit of the new implant resulting from precise, high-quality canal milling and the reduction of bone sacrificed to fit the new implant. Our starting points are the ROBODOC (R) system for primary hip replacement surgery and the manual RTHR surgical protocol. We first discuss the main difficulties of computer-integrated RTHR surgery and identify key issues and possible solutions. We then describe possible system architectures and protocols for preoperative planning and intraoperative execution. We present a summary of methods and preliminary results in CT image metal artifact removal, interactive cement cut-volume definition and cement machining, anatomy-based registration using fluoroscopic X-ray images and clinical trials using an extended RTHR version of ROBODOC. We conclude with a summary of lessons learned and a discussion of current and future work.
Abstract : In the present study measurement of radon and its progeny concentration has been under... more Abstract : In the present study measurement of radon and its progeny concentration has been undertaken in the buildings constructed in the surroundings of National Hydroelectric Power Corporation (NHPC). LR-115 Type-II solid state nuclear track detectors fixed on a thick flat ...
Solid State Nuclear Track Detectors (SSNTD) are commonly used for long term measurements of radon... more Solid State Nuclear Track Detectors (SSNTD) are commonly used for long term measurements of radon, thoron and progeny concentrations. In the present study, we compared the optical counting method and the spark counting technique for counting the alpha tracks on LR 115 track detector films. The paper discusses the various parameters that are innate in the process. More than 300
To assess the perceived health problems and help seeking behaviour and utilization pattern of ado... more To assess the perceived health problems and help seeking behaviour and utilization pattern of adolescent health clinics. A pre-tested, semi-structured questionnaire was administered to 360 school going adolescents who were selected by stratified random sampling from two sectors of Chandigarh where services were being provided by a school-based and dispensary-based adolescent health clinic. Majority (81%) of the adolescents reported having some health problem during last three months prior to the survey; predominant (60%) problems were psychological and behavioural in nature. To resolve these problems boys consulted mainly friends/peers (48%) while girls consulted their mothers (63%). Compared to the dispensary-based adolescent health clinic, utilisation was significantly higher in a school-based clinic where proportion of psychological or behavioural problems reported was also significantly higher (P<0.01). Adolescents have greater counselling needs for psychosocial problems than...
Molecular and cellular endocrinology, Jan 14, 2010
The role of the newly discovered estrogen receptor GPR30 in islet physiology and pathophysiology ... more The role of the newly discovered estrogen receptor GPR30 in islet physiology and pathophysiology is unclear. We examined GPR30 expression in relation to hormone secretion and possible anti-apoptotic effects in isolated mouse islets using the synthetic GPR30 ligand G-1. The mRNA and protein expression of GPR30 was analyzed by qPCR, Western blot and confocal microscopy. Hormone secretion and cAMP content were determined with RIA and apoptosis in islet cells with the Annexin-V method. GPR30 mRNA and protein expression was markedly higher in islets from females compared to male. This gender difference was not found for the genomic estrogen receptors ER alpha and ER beta, the ER alpha expression being 10-fold higher than ER beta in both genders. Confocal microscopy revealed abounden GPR30 expression in insulin, glucagon and somatostatin cells. Dose-response studies of G-1 vs 17beta-estradiol in isolated islets at 1 or 12 mM glucose showed an almost identical pattern in that both compound...
More than a century after its discovery, the physiological implications of the renin-angiotensin ... more More than a century after its discovery, the physiological implications of the renin-angiotensin system (RAS) continue to expand, with the identification of new components, functions and subsystems. These advancements have led to better management and understanding of a broad range of cardiovascular and metabolic disorders. The RAS has traditionally been viewed as a circulatory system, involved in the short-term regulation of volume and blood pressure homeostasis. Recently, local RASs have been described as regulators of chronic tissue effects. Most recently, studies have provided evidence of a complete, functional RAS within cells, described as an 'intracrine' or intracellular system. A more comprehensive understanding of the intracellular RAS provides for new strategies in system regulation and a more efficacious approach to the management of RAS-related diseases.
New fluorescent sensors 6, 7 and 9 based on calix[4]arenes have been synthesized and examined for... more New fluorescent sensors 6, 7 and 9 based on calix[4]arenes have been synthesized and examined for their binding abilities towards different metal ions (Li + , Na + , K + , Pb 2+ , Zn 2+ , Hg 2+ and Ag + ) by UV and fluorescence spectroscopy. Two of these receptors (6 and 7) show ratiometric sensing while the third receptor (9) shows 'On-Off' signaling of Pb 2+ ion among the various metal ions tested. The stoichiometry of the complexation was found to be 1:1 as established by Job's plot.
Although they correspond to an important fraction of the total area of mountain glaciers (33000 k... more Although they correspond to an important fraction of the total area of mountain glaciers (33000 km 2 out of 546000 km 2 ), Himalayan glaciers and their mass balance are poorly sampled. For example, between 1977 and 1999, the average area surveyed each year on the field was 6.8 km 2 only. No direct mass balance measurement is available after 1999. To contribute to fill this gap, we use remote sensing data to monitor glacier elevation changes and mass balances in the Spiti/Lahaul region (32.2°N, 77.6°E, Himachal Pradesh, Western Himalaya, India). Our measurements are obtained by comparing a 2004 digital elevation model (DEM) to the 2000 SRTM (Shuttle Radar Topographic Mission) topography.
Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a gen... more Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a genome-wide association study (GWAS) followed by replication in a combined total of 10,503 PACG cases and 29,567 controls drawn from 24 countries across Asia, Australia, Europe, North America, and South America. We observed significant evidence of disease association at five new genetic loci upon meta-analysis of all patient collections. These loci are at EPDR1 rs3816415 (odds ratio (OR) = 1.24, P = 5.94 × 10(-15)), CHAT rs1258267 (OR = 1.22, P = 2.85 × 10(-16)), GLIS3 rs736893 (OR = 1.18, P = 1.43 × 10(-14)), FERMT2 rs7494379 (OR = 1.14, P = 3.43 × 10(-11)), and DPM2-FAM102A rs3739821 (OR = 1.15, P = 8.32 × 10(-12)). We also confirmed significant association at three previously described loci (P < 5 × 10(-8) for each sentinel SNP at PLEKHA7, COL11A1, and PCMTD1-ST18), providing new insights into the biology of PACG.
Key Word Index*P[ khasiana^P[ manii^P[ pedicellosum^P[ thomsoni^Piperaceae^2!"2\3! dimethoxypheny... more Key Word Index*P[ khasiana^P[ manii^P[ pedicellosum^P[ thomsoni^Piperaceae^2!"2\3! dimethoxyphenyl#propanoylpyrrole^03!benzoð0\2Łdioxol!4!yl!tetradecan!1!ol^1!acetoxy!0\2! dimethoxy!4!"1!propenyl#benzene^1\5!dimethoxy!3!"1!propenyl#phenol^amides^~avones^lig! nans^b!sitosteryl palmitate^"¦#!asarinin^X!ray structure Abstract*Thirty eight compounds of di}erent types have been isolated from twelve Piper species[ The ether extract of the leaves of P[ aduncum yielded eleven compounds\ out of which 1\5!dimethoxy!3!"1!pro! penyl#phenol was isolated for the _rst time from the genus Piper and 1!acetoxy!0\2!dimethoxy!4!"1!pro! penyl#benzene is a new compound[ The petrol extract of the stems and leaves of P[ attenuatum furnished a novel long chain alcohol\ 03!benzoð0\2Łdioxol!4!yl!tetradecan!1!ol[ From P[ betle\ b!sitosteryl palmitate was isolated for the _rst time from the genus Piper[ A novel amide\ 2!"2\3!dimethoxyphenyl#propanoyl pyrrole has been obtained from P[ brachystachyum[ Nerolidol was isolated for the _rst time from P[ falconeri[ From the methanol extract of the stems and leaves of P[ khasiana\ piperlonguminine\ piperine\ apigenin dimethyl ether and b!sitosterol were obtained[ Retrofractamide A was obtained for the _rst time from P[ lon`um^the structure of "¦#!asarinin\ isolated from P[ lon`um\ was con_rmed by X!ray crystallographic studies[ Retrofractamide A\ apigenin dimethyl ether\ tetratriacontanol and tectochrysin were isolated from P[ manii[ P[ pedicellosum furnished b!sitosterol\ pellitorine\ piperlonguminine\ cepharadione A and furacridone\ the last compound being isolated for the _rst time from the genus Piper[ Þ 0887
We report the demonstration of an all-optical, bias free and errorfree (bit-error-rate ~10 −12 ),... more We report the demonstration of an all-optical, bias free and errorfree (bit-error-rate ~10 −12 ), 10Gbit/s non-return-to-zero (NRZ) to return-tozero (RZ) data format conversion using a 7.5µm diameter III-V-on-silicon microdisk resonator. The device is completely processed in a 200mm CMOS pilot line. The data format conversion is based on the phenomenon of pulse carving of an NRZ optical data stream by an optical clock. The underlying physical effect for the pulse carving is the change in the refractive index caused by the generation of free-carriers in a pump -probe configuration. We believe it to be the first NRZ-to-RZ format convertor built on a hybrid III-V-on-silicon technology platform.
Most households in low and middle income countries, including in India, use solid fuels (coal/cok... more Most households in low and middle income countries, including in India, use solid fuels (coal/coke/lignite, firewood, dung, and crop residue) for cooking and heating. Such fuels increase child mortality, chiefly from acute respiratory infection. There are, however, few direct estimates of the impact of solid fuel on child mortality in India. We compared household solid fuel use in 1998 between 6790 child deaths, from all causes, in the previous year and 609 601 living children living in 1.1 million nationally-representative homes in India. Analyses were stratified by child's gender, age (neonatal, post-neonatal, 1-4 years) and colder versus warmer states. We also examined the association of solid fuel to non-fatal pneumonias. Solid fuel use was very common (87% in households with child deaths and 77% in households with living children). After adjustment for demographic factors and living conditions, solid-fuel use significantly increase child deaths at ages 1-4 (prevalence ratio...
The passage of heavy ions in a track detector polymeric material produces lattice deformations. T... more The passage of heavy ions in a track detector polymeric material produces lattice deformations. These deformations may be in the form of latent tracks or may vanish by self annealing in time. Heavy ion irradiation produces modifications in polymers in their relevant electrical, chemical and optical properties in the form of rearrangement of bonding, cross-linking, chain scission, formation of carbon rich clusters and changes in dielectric properties etc. Modification depends on the ion, its energy and fluence and the polymeric material. In the present work, a study of the dielectric response of pristine and heavy ion irradiated Makrofol-KG polycarbonate is carried out. 40 μm thick Makrofol-KG polycarbonate films were irradiated to various fluences with Si 8+ ions of 100 MeV energy from Pelletron at Inter University Accelerator Centre (IUAC), New Delhi and Ne 6+ ions of 145 MeV from Variable Energy Cyclotron Centre, Kolkata. On irradiation with heavy ions dielectric constant ( ) decreases with frequency where increases with fluence for both the ions. Variation of loss factor (tan ) with frequency for pristine and irradiated with Si ions reveals that tan increases as the frequency increases. Tan also increases with fluence. While Ne irradiated samples tan shows slight variation with frequency as well as with fluence. Tan has positive values indicating the dominance of inductive behavior.
This paper describes an ongoing project to develop a computer-integrated system to assist surgeon... more This paper describes an ongoing project to develop a computer-integrated system to assist surgeons in revision total hip replacement (RTHR) surgery. In RTHR surgery, a failing orthopedic hip implant, typically cemented, is replaced with a new one by removing the old implant, removing the cement and fitting a new implant into an enlarged canal broached in the femur. RTHR surgery is a difficult procedure fraught with technical challenges and a high incidence of complications. The goals of the computer-based system are the significant reduction of cement removal labor and time, the elimination of cortical wall penetration and femur fracture, the improved positioning and fit of the new implant resulting from precise, high-quality canal milling and the reduction of bone sacrificed to fit the new implant. Our starting points are the ROBODOC (R) system for primary hip replacement surgery and the manual RTHR surgical protocol. We first discuss the main difficulties of computer-integrated RTHR surgery and identify key issues and possible solutions. We then describe possible system architectures and protocols for preoperative planning and intraoperative execution. We present a summary of methods and preliminary results in CT image metal artifact removal, interactive cement cut-volume definition and cement machining, anatomy-based registration using fluoroscopic X-ray images and clinical trials using an extended RTHR version of ROBODOC. We conclude with a summary of lessons learned and a discussion of current and future work.
Abstract : In the present study measurement of radon and its progeny concentration has been under... more Abstract : In the present study measurement of radon and its progeny concentration has been undertaken in the buildings constructed in the surroundings of National Hydroelectric Power Corporation (NHPC). LR-115 Type-II solid state nuclear track detectors fixed on a thick flat ...
Solid State Nuclear Track Detectors (SSNTD) are commonly used for long term measurements of radon... more Solid State Nuclear Track Detectors (SSNTD) are commonly used for long term measurements of radon, thoron and progeny concentrations. In the present study, we compared the optical counting method and the spark counting technique for counting the alpha tracks on LR 115 track detector films. The paper discusses the various parameters that are innate in the process. More than 300
To assess the perceived health problems and help seeking behaviour and utilization pattern of ado... more To assess the perceived health problems and help seeking behaviour and utilization pattern of adolescent health clinics. A pre-tested, semi-structured questionnaire was administered to 360 school going adolescents who were selected by stratified random sampling from two sectors of Chandigarh where services were being provided by a school-based and dispensary-based adolescent health clinic. Majority (81%) of the adolescents reported having some health problem during last three months prior to the survey; predominant (60%) problems were psychological and behavioural in nature. To resolve these problems boys consulted mainly friends/peers (48%) while girls consulted their mothers (63%). Compared to the dispensary-based adolescent health clinic, utilisation was significantly higher in a school-based clinic where proportion of psychological or behavioural problems reported was also significantly higher (P<0.01). Adolescents have greater counselling needs for psychosocial problems than...
Molecular and cellular endocrinology, Jan 14, 2010
The role of the newly discovered estrogen receptor GPR30 in islet physiology and pathophysiology ... more The role of the newly discovered estrogen receptor GPR30 in islet physiology and pathophysiology is unclear. We examined GPR30 expression in relation to hormone secretion and possible anti-apoptotic effects in isolated mouse islets using the synthetic GPR30 ligand G-1. The mRNA and protein expression of GPR30 was analyzed by qPCR, Western blot and confocal microscopy. Hormone secretion and cAMP content were determined with RIA and apoptosis in islet cells with the Annexin-V method. GPR30 mRNA and protein expression was markedly higher in islets from females compared to male. This gender difference was not found for the genomic estrogen receptors ER alpha and ER beta, the ER alpha expression being 10-fold higher than ER beta in both genders. Confocal microscopy revealed abounden GPR30 expression in insulin, glucagon and somatostatin cells. Dose-response studies of G-1 vs 17beta-estradiol in isolated islets at 1 or 12 mM glucose showed an almost identical pattern in that both compound...
More than a century after its discovery, the physiological implications of the renin-angiotensin ... more More than a century after its discovery, the physiological implications of the renin-angiotensin system (RAS) continue to expand, with the identification of new components, functions and subsystems. These advancements have led to better management and understanding of a broad range of cardiovascular and metabolic disorders. The RAS has traditionally been viewed as a circulatory system, involved in the short-term regulation of volume and blood pressure homeostasis. Recently, local RASs have been described as regulators of chronic tissue effects. Most recently, studies have provided evidence of a complete, functional RAS within cells, described as an 'intracrine' or intracellular system. A more comprehensive understanding of the intracellular RAS provides for new strategies in system regulation and a more efficacious approach to the management of RAS-related diseases.
New fluorescent sensors 6, 7 and 9 based on calix[4]arenes have been synthesized and examined for... more New fluorescent sensors 6, 7 and 9 based on calix[4]arenes have been synthesized and examined for their binding abilities towards different metal ions (Li + , Na + , K + , Pb 2+ , Zn 2+ , Hg 2+ and Ag + ) by UV and fluorescence spectroscopy. Two of these receptors (6 and 7) show ratiometric sensing while the third receptor (9) shows 'On-Off' signaling of Pb 2+ ion among the various metal ions tested. The stoichiometry of the complexation was found to be 1:1 as established by Job's plot.
Although they correspond to an important fraction of the total area of mountain glaciers (33000 k... more Although they correspond to an important fraction of the total area of mountain glaciers (33000 km 2 out of 546000 km 2 ), Himalayan glaciers and their mass balance are poorly sampled. For example, between 1977 and 1999, the average area surveyed each year on the field was 6.8 km 2 only. No direct mass balance measurement is available after 1999. To contribute to fill this gap, we use remote sensing data to monitor glacier elevation changes and mass balances in the Spiti/Lahaul region (32.2°N, 77.6°E, Himachal Pradesh, Western Himalaya, India). Our measurements are obtained by comparing a 2004 digital elevation model (DEM) to the 2000 SRTM (Shuttle Radar Topographic Mission) topography.
Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a gen... more Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a genome-wide association study (GWAS) followed by replication in a combined total of 10,503 PACG cases and 29,567 controls drawn from 24 countries across Asia, Australia, Europe, North America, and South America. We observed significant evidence of disease association at five new genetic loci upon meta-analysis of all patient collections. These loci are at EPDR1 rs3816415 (odds ratio (OR) = 1.24, P = 5.94 × 10(-15)), CHAT rs1258267 (OR = 1.22, P = 2.85 × 10(-16)), GLIS3 rs736893 (OR = 1.18, P = 1.43 × 10(-14)), FERMT2 rs7494379 (OR = 1.14, P = 3.43 × 10(-11)), and DPM2-FAM102A rs3739821 (OR = 1.15, P = 8.32 × 10(-12)). We also confirmed significant association at three previously described loci (P < 5 × 10(-8) for each sentinel SNP at PLEKHA7, COL11A1, and PCMTD1-ST18), providing new insights into the biology of PACG.
Key Word Index*P[ khasiana^P[ manii^P[ pedicellosum^P[ thomsoni^Piperaceae^2!"2\3! dimethoxypheny... more Key Word Index*P[ khasiana^P[ manii^P[ pedicellosum^P[ thomsoni^Piperaceae^2!"2\3! dimethoxyphenyl#propanoylpyrrole^03!benzoð0\2Łdioxol!4!yl!tetradecan!1!ol^1!acetoxy!0\2! dimethoxy!4!"1!propenyl#benzene^1\5!dimethoxy!3!"1!propenyl#phenol^amides^~avones^lig! nans^b!sitosteryl palmitate^"¦#!asarinin^X!ray structure Abstract*Thirty eight compounds of di}erent types have been isolated from twelve Piper species[ The ether extract of the leaves of P[ aduncum yielded eleven compounds\ out of which 1\5!dimethoxy!3!"1!pro! penyl#phenol was isolated for the _rst time from the genus Piper and 1!acetoxy!0\2!dimethoxy!4!"1!pro! penyl#benzene is a new compound[ The petrol extract of the stems and leaves of P[ attenuatum furnished a novel long chain alcohol\ 03!benzoð0\2Łdioxol!4!yl!tetradecan!1!ol[ From P[ betle\ b!sitosteryl palmitate was isolated for the _rst time from the genus Piper[ A novel amide\ 2!"2\3!dimethoxyphenyl#propanoyl pyrrole has been obtained from P[ brachystachyum[ Nerolidol was isolated for the _rst time from P[ falconeri[ From the methanol extract of the stems and leaves of P[ khasiana\ piperlonguminine\ piperine\ apigenin dimethyl ether and b!sitosterol were obtained[ Retrofractamide A was obtained for the _rst time from P[ lon`um^the structure of "¦#!asarinin\ isolated from P[ lon`um\ was con_rmed by X!ray crystallographic studies[ Retrofractamide A\ apigenin dimethyl ether\ tetratriacontanol and tectochrysin were isolated from P[ manii[ P[ pedicellosum furnished b!sitosterol\ pellitorine\ piperlonguminine\ cepharadione A and furacridone\ the last compound being isolated for the _rst time from the genus Piper[ Þ 0887
We report the demonstration of an all-optical, bias free and errorfree (bit-error-rate ~10 −12 ),... more We report the demonstration of an all-optical, bias free and errorfree (bit-error-rate ~10 −12 ), 10Gbit/s non-return-to-zero (NRZ) to return-tozero (RZ) data format conversion using a 7.5µm diameter III-V-on-silicon microdisk resonator. The device is completely processed in a 200mm CMOS pilot line. The data format conversion is based on the phenomenon of pulse carving of an NRZ optical data stream by an optical clock. The underlying physical effect for the pulse carving is the change in the refractive index caused by the generation of free-carriers in a pump -probe configuration. We believe it to be the first NRZ-to-RZ format convertor built on a hybrid III-V-on-silicon technology platform.
Most households in low and middle income countries, including in India, use solid fuels (coal/cok... more Most households in low and middle income countries, including in India, use solid fuels (coal/coke/lignite, firewood, dung, and crop residue) for cooking and heating. Such fuels increase child mortality, chiefly from acute respiratory infection. There are, however, few direct estimates of the impact of solid fuel on child mortality in India. We compared household solid fuel use in 1998 between 6790 child deaths, from all causes, in the previous year and 609 601 living children living in 1.1 million nationally-representative homes in India. Analyses were stratified by child's gender, age (neonatal, post-neonatal, 1-4 years) and colder versus warmer states. We also examined the association of solid fuel to non-fatal pneumonias. Solid fuel use was very common (87% in households with child deaths and 77% in households with living children). After adjustment for demographic factors and living conditions, solid-fuel use significantly increase child deaths at ages 1-4 (prevalence ratio...
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Papers by rajesh kumar