Browsing by Author "Aparna Shukla"

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Brominated Graphene as Mimetic Peroxidase for Sulfide Ion Recognition
(American Chemical Society, 2017) Shikha Singh; Kheyanath Mitra; Aparna Shukla; Rajshree Singh; Ravi Kumar Gundampati; Nira Misra; Pralay Maiti; Biswajit Ray
Brominated graphene (GBR) with ∼3% bromine content has shown novel peroxidase mimetic activity toward 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2. Optimum activity has been observed at pH 4.48 and after a minimum ∼30 min of equilibration time. Among the different analytes studied using the sensor combining TMB, H2O2, and GBR in phosphate buffer of pH 4.48, the S2- ion has effectively shown a short duration of sensing (∼2 min) within the detection range of 0.04-1 mM. A calibration curve for S2- ion estimation has been constructed with the experimental linearity in 0.04-0.4 mM range and having the limit of detection (LOD) value of 25.3 μM. A standard addition experiment has validated the method. A paper strip sensor has been fabricated for successful detection of S2- ion. © 2016 American Chemical Society.
Dextrin and polyurethane graft copolymers as drug carrier: Synthesis, characterization, drug release, biocompatibility and in-vitro toxicity
(Elsevier Ltd, 2021) Aparna Shukla; Swapan Maity; Biswajit Ray; Pralay Maiti
Chemical modification of dextrin with polyurethane as a graft has been synthesized for controlled drug release for longer time period by maintaining the hydrophobic–hydrophilic balance. Estimation of the degree of grafting is visualized from the integrated peak area in the NMR spectra. Particle nature of dextrin is converted into strip like morphology in polyurethane graft dextrin copolymers as obvious from atomic force microscopy. Drug release study of graft copolymers through in vitro studies indicates sustained drug release behavior as compared to pristine dextrin and specific interactions between polymer and drug have been verified through spectroscopic techniques. Biocompatibility of the graft copolymers has been revealed using cellular studies on cancerous HeLa cells through MTT assay and cell adhesion. Further, the cytotoxicity or the cell killing efficiency has been demonstrated resulting in significant cell mortality using the developed graft copolymers. © 2021
Dulung Proglacial Lake, Suru Sub-Basin, Western Himalaya: Evolution, Controls and Impacts on Glacier Stability
(Frontiers Media S.A., 2022) Siddhi Garg; Purushottam Kumar Garg; Bisma Yousuf; Aparna Shukla; Uma Kant Shukla
Proglacial lakes are continually developing and expanding across the Himalayan glaciered terrain in response to climate change. These lakes are known to destabilize the glaciers by enhancing their frontal ablation, causing higher than average glacier area and mass losses. Thus, to comprehend the dynamics of proglacial lakes and their influence on the overall glacier health, we study the lake-terminating Dulung Glacier located in the Suru sub-basin, Ladakh, western Himalaya and compare it with the adjacent land-terminating Chilung Glacier. The pronounced melting of the Dulung Glacier, supported by glacier topography (surface gradient between accumulation and ablation zone) and valley morphology (wider near the snout and narrower downwards), seems to be the prime reason for the formation, accommodation and sustenance of the proglacial lake. The expansion in proglacial lake (.008 km2a−1) during 1977–2018 is accompanied by an enhanced degeneration of the Dulung Glacier (mass balance: −.47 ±.06 m w.e.a−1, shrinkage rate:.3 ±.001% a−1; retreat rate: 32 ±.7 ma−1, surface ice velocity reduction: 16%), which has accelerated post-1993. In comparison, land-terminating Chilung Glacier shows lower degeneration rates (mass balance: −.28 ±.02 m w.e.a−1; shrinkage rate:.2 ±.001% a−1; retreat rate: 17 ± 0.7 ma−1, surface ice velocity reduction: 8%) during 1971–2018. This suggests a substantial impact of the proglacial lake in enhancing the Dulung Glacier’s sensitivity towards climate change compared to the Chilung Glacier. If the current rate of lake expansion continues, it would further enhance the Dulung Glaciers’ degeneration rates, thus impacting its stability. Copyright © 2022 Garg, Garg, Yousuf, Shukla and Shukla.
Efficacy of polyurethane graft on cyclodextrin to control drug release for tumor treatment
(Academic Press Inc., 2019) Aparna Shukla; Akhand Pratap Singh; Biswajit Ray; Vinod Aswal; Amrita G. Kar; Pralay Maiti
Hydrophilicity of cyclodextrin is controlled through grafting of polyurethane of varying graft density, thereby maintain the hydrophilic-hydrophobic balance, to sustain the drug delivery rate for better tumor treatment. Grafting is verified through nuclear magnetic resonance (1H NMR) and other spectroscopic techniques along with the hydrodynamic volume measurement of grafted species and the degree of substitution has been calculated from the integrated peak areas. Thermal and mechanical stability of the graft copolymers have improved significantly with respect to cyclodextrin and the formation of smaller blobs having larger in number has been obtained from small angle neutron scattering, atomic force microscopy and optical images. Sustained drug delivery has been achieved using graft copolymer as opposed to burst release in pure cyclodextrin and polyurethane and the phenomenon is understood from the specific interactions, as observed though spectroscopic and thermal measurement, between graft copolymer and drug followed by this novel architecture of the graft copolymers. Biocompatibility of graft copolymers has been checked using cellular studies through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell adhesion. Importantly, the cell killing efficiency has been demonstrated by embedding anti-cancer drug in polymer matrices causing mortality rate of 80% using graft copolymer against meagre 20% using pure drug or drug embedded in cyclodextrin and the result is realised from the sustained release of drug from the graft copolymer vis-à-vis burst release in other systems. Cellular studies have been translated into an animal model showing the efficacy of newly developed patch, made of drug embedded in copolymer, towards the significant suppression of tumors in mice as compared to control. Histopathological images and biochemical parameters indicate the normal body organ/blood in copolymer treated mice against severely damaged organ especially liver/blood in the mice treated with pure drug or drug embedded in cyclodextrin arising from burst release. Thus, graft copolymer with unique architecture is found to be an effective drug delivery vehicle for melanoma cancer treatment without side effect. © 2018 Elsevier Inc.
Field evidences showing rapid frontal degeneration of the Kangriz glacier, western Himalayas, Jammu & Kashmir
(Science Press, 2018) Siddhi Garg; Aparna Shukla; Manish Mehta; Vinit Kumar; Shruti Anna Samuel; S.K. Bartarya; Uma Kant Shukla
Life cycle of glaciers in the Himalayan region has notably changed due to the climatic variability since last few decades. Glaciers across the world and specially the Himalayan glaciers have shown large scale degeneration in the last few decades. Himalayan glaciers serve as an important fresh water resource for the downstream communities, who are dependent on this water for domestic and other purposes. Therefore, glacier shrinkage and the associated hydrological changes pose a significant problem for regional-scale water budgets and resource management. These issues necessitate the regular and rigorous monitoring of the wastage pattern of the Himalayan glaciers in field and using satellite remote sensing data. In this work, we report rapid and enhanced degeneration of the frontal part of the Kangriz glacier, Jammu and Kashmir (J & K), in terms of surface melting, debris cover, snout characteristics and meltwater discharge. Ablation data acquired during 2016–2017 shows the average lowering of the frontal part of the glacier to be ~148 ± 34 cm, one-third of which was found to have occurred within a 13 day time period in September, 2017. Also, the quantum of ice melt was found to be inversely influenced (r = -0.84) by the debris thickness. 15 day meltwater discharge measurement revealed its strong relationship with snout disintegration pattern, evidenced twice during the said time period. Volume of water discharged from the glacier was estimated to be 7.91×106 m3 for the measurement duration. Also, mean daily discharge estimated for the 15 days interval showed good positive correction (r = 0.78) with temperature indicating the direct dependency of the former on land surface temperature conditions of the region. Besides the lowering and discharge observations, the frequent ice-block break-offs at the glacier snout further enhance its overall drastic degeneration. The study suggests that, being the largest glacier in the Suru basin, the Kangriz glacier needs to be continuously monitored in order to understand its glacio-hydrological conditions. © 2018, Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag GmbH Germany, part of Springer Nature.
Grafted cyclodextrin as carrier for control drug delivery and efficient cell killing
(John Wiley and Sons Inc, 2019) Aparna Shukla; Biswajit Ray; Pralay Maiti
The presence of hydroxyl groups in cyclodextrin (CD) makes it highly hydrophilic and simultaneously allows its chemical modification to graft polyurethane to control the drug release for longer period of time by maintaining the hydrophobic–hydrophilic balance through varying extent of grafting. Grafting of polyurethane on CD is confirmed through 1H NMR and molecular weight measurement while FTIR and UV visible studies further support grafting and emphasize the interaction among polymer chains as a whole. Degree of grafting is evaluated from the integrated peak area in NMR spectra. Thermal and mechanical measurements show improved stability and strength of the graft polymers with respect to pure CD. The conversion of particle nature of CD to strip-like morphology in graft copolymers is evident from atomic force microscopy. Sustained drug release has been achieved using graft copolymer against burst release from pure CD and specific interactions, as observed through spectroscopy and thermal measurements, are responsible for sustained release of drug. Biocompatibility of graft copolymers has been checked using cellular studies through MTT assay and cell adhesion. Importantly, the cell killing efficiency has been demonstrated by embedding anticancer drug in polymer matrices causing mortality rate of 75% using graft copolymer against scanty 25% using pure drug or drug embedded in CD and the result is understood from the sustained release of drug from the graft copolymer vis-à-vis burst release in other systems. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 434–444, 2019. © 2018 Wiley Periodicals, Inc.
On geomorphic manifestations and glaciation history of the Kangriz glacier, western Himalaya
(Wadia Institute of Himalayan Geology, 2019) Siddhi Garg; Aparna Shukla; Manish Mehta; Vinit Kumar; Uma Kant Shukla
Glaciers modify the landscape, forming the erosional and depositional landforms, which in turn can be used for reconstructing the palaeoglacial events. However, the rates of landscape evolution and dynamics are poorly understood in the remote and inaccessible glaciated Himalayan environments. To help elucidate the origin of landforms and to quantify rates of landscape evolution in such an environment, we undertook an in-depth geomorphological investigation of the Kangriz glacier and adjoining areas, Suru sub-basin, western Himalayas (WH), Jammu and Kashmir, India. Based on detailed field investigations and large scale geomorphological mapping, five prominent stages of lateral moraines (Kangriz glacial stage: KGS-I to V) could be identified in chronological order along with several short lived glacial phases. Other than the lateral moraines, ~11 phases of retreat manifested as recessional mounds (RM) are preserved between KGS-IV 3 and the present day snout (PDS), which suggest an overall loss of ~619 m (length) and ~7 km (glacier volume) from KGS-IV to the present time. Though denuded, the location and dimensions of these RMs not only defines the strength of the respective degenerative phase but are clear evidences of an active glacier snout. Besides, palaeo-Equilibrium Line Altitude (ELA) reconstruction reveals an overall rise in the ELA by 966 m between the KGS-I and PDS (from 4357 to 5323 masl), which is suggestive of an overall warming of the climatic conditions. This study reiterates the necessity of analyzing the surrounding landscape in detail for developing a comprehensive understanding about the past behavior and present response of the glacier. © 2019, Wadia Institute of Himalayan Geology. All rights reserved.
Photosensitization Ability of 1,7-Phenanthroline Based Bis-BODIPYs: Perplexing Role of Intramolecular Rotation on Photophysical Properties
(American Chemical Society, 2019) Vishwa Deepak Singh; Roop Shikha Singh; Bhupendra Kumar Dwivedi; Sujay Mukhopadhyay; Aparna Shukla; Pralay Maiti; Daya Shankar Pandey
1,7-Phenanthroline based bis-boron dipyrromethenes (bis-BODIPYs) B1 and B2 obtained via small substitutional changes (-Cl/-SCH3) have been described. The effect of restriction of intramolecular rotation (RIR) in emission enhancement in a viscous solvent (glycerol) has been studied besides the vital role of intermolecular interactions scrutinized by X-ray single-crystal studies. The efficiency of intersystem crossing (ISC) in the generation of singlet oxygen (φ ∼19.2% and 56.7%) by photoirradiation using visible light along with distinct photostability has been investigated by 1,3-diphenylisobenzofuran (DPBF) titration studies. The 1O2 generation quantum yield and photosensitizing durability of the bis-BODIPYs have been investigated by photooxidation of 1,5-dihydroxynaphthalene (DHN) in the presence of B1 and B2 as photosensitizers. The pseudo-first-order rate constants for photooxidation reactions and consumption rates of DHN reflected appreciable 1O2 generation quantum yields (φ: B1, 29.0; B2, 57.8%). Density functional theory (DFT) studies showed the distribution of electron density over the dipyrrin moiety. Overall results indicated that these new photosensitizers (PSs) may be very promising in photodynamic therapy of tumors, photobiology, and organic photochemistry. Copyright © 2019 American Chemical Society.
Revisiting the 24 year (1994-2018) record of glacier mass budget in the Suru sub-basin, western Himalaya: Overall response and controlling factors
(Elsevier B.V., 2021) Siddhi Garg; Aparna Shukla; Purushottam Kumar Garg; Bisma Yousuf; Uma Kant Shukla; Sonam Lotus
Glacier mass balance time-series measurements have immense importance in comprehending the overall regional hydrology and meteorology of the mountain systems. Such assessments are critical in the Indus River basin (compared to the Ganga and Brahmaputra), which besides having a significant contribution from the glaciers, also exhibits considerable heterogeneity in glacier response. Thus, to quantify this variability in glacier behavior and thereby develop a comprehensive understanding of the past as well as the future evolution of the glaciers, we reconstruct the annual surface mass balance records of 75 glaciers (size >1 km2) in the Suru sub-basin, western Himalaya for the period 1994-2018. We apply a remote sensing-based equilibrium line altitude-mass balance approach, supported by geodetic mass balance estimates (for 18 major glaciers) and limited field measurements. Our findings suggest a persistent negative mass balance of the glaciers (average: -0.69 ± 0.28 m w.e.a-1, cumulative: -16.56 m w.e), varying from -0.46 ± 0.27 (1997) to -0.79 ± 0.28 (2018) m w.e.a-1 during the study period. This overall mass loss coincides with an increased temperature (Tavg increased 0.5 °C; Tmin increased 0.27 °C; Tmax increased 0.06 °C) and reduced precipitation (by 4%) in the valley during 1994-2018, which shows the sensitivity of these glaciers to climate change. Within the Suru sub-basin, smaller, cleaner and high-altitude mountain glaciers of the Ladakh range have experienced greater mass loss (cumulative: -20.88 m w.e) compared to the Greater Himalayan range (cumulative: -13.44 m w.e). We observe latitudinal variability in mass loss in the Western Himalaya, with the highest mass loss rates in the Greater Himalayan Range (>-0.9 m w.e.a-1) and lowest in the Karakoram Range (<-0.1 m w.e.a-1), suggesting a transitional response of the Suru sub-basin glaciers (-0.69 m w.e.a-1). The overall regional picture suggests synchronicity in the mass loss pattern of western Himalayan glaciers, predominantly controlled by the climatic conditions. Meanwhile, the variability in their mass loss rates is attributed to the unique glacier characteristics. © 2021
Sensitivity of glaciers in part of the suru basin, western himalaya to ongoing climatic perturbations
(Springer International Publishing, 2019) Aparna Shukla; Siddhi Garg; Vinit Kumar; Manish Mehta; Uma Kant Shukla
Temporal and spatial climate variability acts as the major driving force which induces changes in glacier response. However, variation in the glacier behavior could also be introduced due to the influence of non-climatic factors. Therefore, in order to assess the influence of these climatic and non-climatic factors on the response of 15 major glaciers of the Suru basin, western Himalayas, Jammu and Kashmir, a multiparametric study has been carried out involving estimation of dimensional (area and length changes) parameters, snowline altitude (SLA)/accumulation area ratio (AAR) and non-climatic factors (debris cover and topographic). Satellite data from the Landsat series sensors (MSS/TM/ETM+/OLI) during the period 1977–2016 along with the Shuttle Radar Topographic Mission (SRTM) Global Digital Elevation Model version-3 (GDEM v-3) constitute the primary datasets used. Results indicate towards an overall negative health of the glaciers with 6.25 ± 0.0012% loss in glacier area and increase in the average retreat rate from 16 ± 3.4 (1977) to 23 ± 3.4 m/y (2016). This glacier degeneration was accompanied by a debris cover increase of ~80% and mean snow line altitude (SLA) upshift of 116 ± 17 m over the span of 39 years. The observed glacier changes exhibit strong correlation with long-term temperature variability (average r2 = 0.481 ± 0.06; maximum r2 = 0.925), however, sensitivity to precipitation trends (average r2 = 0.143 ± 0.07) is not found to be significant. Besides, disparity in glacier response can be partly explained by the spatial variability in meteorological parameters, with glaciers of the Ladakh Range (LR) shrinking (area loss: 9%) and accumulating more debris cover (debris increase: 116%) as compared to those in the Greater Himalayan Range (GHR) (6% and 78%, respectively). However, SLA rise was more pronounced in the GHR glaciers (average of 141 ± 97 m). The differential behavior of glaciers in both the ranges can be attributed partly to the impact of the non-climatic factors such as glacier size, length, maximum elevation and mean slope. © Springer Nature Switzerland AG 2020. All rights reserved.
Surface evolution and dynamics of the Kangriz glacier, western Himalaya in past 50 years
(Elsevier B.V., 2022) Siddhi Garg; Aparna Shukla; Purushottam Kumar Garg; Bisma Yousuf; Uma Kant Shukla
Glacier specific studies, in a relatively unexplored terrain of Ladakh, hold immense importance tocomprehend not only the glacier response but also its synchronicity with the general regional trend. Accordingly, in this study, the Kangriz glacier in the Suru sub-basin, western Himalaya, has been taken up for multiparametric (area, terminal retreat, debriscover, snow line altitude, surface dynamics) assessment for the period 1971–2018. Results reveal an overall shrinkage of 3.3 ± 1.6%, with an expansion in the supraglacial debris cover by 45% (1971–2018). Concomitantly, the glacier surface velocity has reduced by 10.85 ± 5.68 ma−1 (35%), from 31.2 ± 5.8 ma−1 (1993/94) to 20.3 ± 1.7 ma−1 (2017/18), with mass wastage of ‐0.52 ± 0.19 m w.e.a−1 during 2000–17. The notable glacier degeneration is synchronous with regional warming (Tmax increase by 7%, Tmin increase by 43%, Tavg increase by 64%) and a decrease in precipitation by 3% (significant at α <0.05). Besides, frontal dynamics have changed recently, with an enhanced intensity of terminal retreat (2016–2018: 57 ± 13(Stdev) ma−1). The overall glacier status suggests a degenerative pattern of the glacier, which is in sync with the other western Himalayan glaciers. In view of the recently amplified ice-calving events and rapid mass loss observed in the snout region, the frontal glacier morphology may change drastically in the coming years. © 2022 Elsevier B.V.
Synthesis, characterization, and application of chitosan nanomaterials loaded with other metals/elements in plant
(Elsevier, 2022) Aparna Shukla; Anand Sharma; Vanya Nayak; Ranjana Verma; Jay Singh
In the last few decades, chitosan nanomaterials have been broadly explored in the field of biology, pharmaceutical, and agriculture because of their unique properties such as diverse biological functions, biodegradability, nontoxic nature, and facile availability. Metal-embedded chitosan-based nanomaterials have gained significant attention as they possess dual properties i.e., growth promotion as well as protection in plants. Furthermore, metals or elements encapsulated in chitosan are less toxic due to the slow-release phenomenon and showed a long-lasting effect in plants. The blending of various metals Zn, Cu, Ag, and other elements with chitosan is known to supplement properties like providing nutrition to plants and help plant growth by protecting them from biotic and abiotic stress. Furthermore, metal-chitosan nanoparticles have predominantly shown antimicrobial functions against many plant pathogenic bacteria and fungi. However, the role of chitosan-based nanomaterials their bioactivity, and pathogenic mode of action is still not much explored which limits their application in agriculture. In order to expedite the predicted role of chitosan metal nanomaterials, it is crucial to assemble all the bioactivity processes responsible for the sustainable growth of plants. In this chapter, we discuss different chitosan/metal-based nanomaterials that have been explored in plant growth and their protection from microbes usually fungi, bacteria and viruses along with their mode of action. © 2022 Elsevier Inc. All rights reserved.
Temporal inventory of glaciers in the Suru sub-basin, western Himalaya: Impacts of regional climate variability
(Copernicus GmbH, 2020) Aparna Shukla; Siddhi Garg; Manish Mehta; Vinit Kumar; Uma Kant Shukla
The importance of updated knowledge about the glacier extent and characteristics in the Himalaya cannot be overemphasized. Availability of precise glacier inventories in the latitudinally diverse western Himalayan region is particularly crucial. In this study we have created an inventory of the Suru sub-basin in the western Himalaya for the year 2017 using Landsat Operational Land Imager (OLI) data. Changes in glacier parameters have also been monitored from 1971 to 2017 using temporal satellite remote-sensing data and limited field observations. Inventory data show that the sub-basin has 252 glaciers covering 11% of the basin, having an average slope of 25±6 (standard deviations have been italicized throughout the text) and dominantly north orientation. The average snow line altitude (SLA) of the basin is 5011±54 m& a.s.l. with smaller (47%) and cleaner (43%) glaciers occupying the bulk area. Long-term climate data (1901-2017) show an increase in the mean annual temperature (Tmax and Tmin) of 0.77°C (0.25 and 1.3°C) in the sub-basin, driving the overall glacier variability in the region. Temporal analysis reveals a glacier shrinkage of 6 ± 0.02%, an average retreat rate of 4.3±1.02, debris increase of 62% and a 22±60m SLA increase in the past 46 years. This confirms their transitional response between the Karakoram and the Greater Himalayan Range (GHR) glaciers. Besides, glaciers in the sub-basin occupy two major ranges, the GHR and Ladakh Range (LR), and experience local climate variability, with the GHR glaciers exhibiting a warmer and wetter climate as compared to the LR glaciers. This variability manifests itself in the varied response of GHR and LR glaciers. While the GHR glaciers exhibit an overall rise in SLA (GHR: 49±69m; LR: decrease of 18±50m), the LR glaciers have deglaciated more (LR: 7%; GHR: 6%) with an enhanced accumulation of debris cover (LR: 73%; GHR: 59%). Inferences from this study reveal prevalence of glacier disintegration and overall degeneration, transition of clean ice to partially debris-covered glaciers, local climate variability and non-climatic (topographic and morphometric)-factor-induced heterogeneity in glacier response as the major processes operating in this region. The Shukla et al. (2019) dataset is accessible at https://doi.org/10.1594/PANGAEA.904131. © Author(s) 2020.
UV-B and UV-C pre-treatments induce physiological changes and artemisinin biosynthesis in Artemisia annua L. - An antimalarial plant
(2011) Rashmi Rai; Ram Prasad Meena; Shachi Shuchi Smita; Aparna Shukla; Sanjay Kumar Rai; Shashi Pandey-Rai
Present study was undertaken to investigate if short-term UV-B (4.2 kJ m-2 day-1) and UV-C (5.7 kJ m-2 day -1), pre-treatments can induce artemisinin biosynthesis in Artemisia annua. Twenty-one day old Artemisia seedlings were subjected to short-term (14 days) UV pre-treatment in an environmentally controlled growth chamber and then transplanted to the field under natural conditions. Treatment of A. annua with artificial UV-B and UV-C radiation not only altered the growth responses, biomass, pigment content and antioxidant enzyme activity but enhanced the secondary metabolites (artemisinin and flavonoid) content at all developmental stages as compared to non-irradiated plants. The extent of oxidative damage was measured in terms of the activities of enzymes such as catalase, superoxide dismutase and ascorbate peroxidase. Reinforcement in the antioxidative defense system seems to be a positive response of plants in ameliorating the negative effects of UV-B and UV-C radiations. While the carotenoid content was elevated, the chlorophyll content decreased under UV-B and UV-C pre-treatments. The reverse transcription PCR analysis of the genes associated in artemisinin/isoprenoid biosynthesis like 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), cytochrome P450 oxidoreductase (CPR) and amorpha-4,11-diene synthase (ADS) genes at different growth stages revealed UV induced significant over-expression of the above protein genes. UV-B and UV-C pre-treatments, led to an increase in the concentrations of artemisinin at full bloom stage by 10.5% and 15.7% than that of the control respectively. Thus, the result of our study suggests that short term UV-B pre-treatment of seedlings in greenhouse prior to transplantation into the field enhances artemisinin production with lesser yield related damages as compared to UV-C radiation in A. annua. © 2011 Elsevier B.V. All rights reserved.