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This work presents an innovative and environmentally friendly biological synthesis approach for producing α-Fe2O3 nanoparticles (NPs) and the successful synthesis of α-Fe2O3/reduced graphene oxide (rGO) nanocomposites (NCs). This novel synthesis route utilizes freshly extracted albumin, serving as both a reducing agent and a stabilizing agent, rendering it eco-friendly, cost-effective, and sustainable. A combination of characterization techniques including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM) was employed to predict and confirm the formation of the as-synthesized α-Fe2O3 NPs and α-Fe2O3/rGO NCs. Transmission electron microscopy (TEM) verified the anisotropic nature of the synthesized nanoparticles. To gain insight into the enhanced capacitance of the α-Fe2O3/rGO NCs, a series of electrochemical tests, namely cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), electrochemical impedance spectroscopy (EIS), and stability assessments, were conducted in a conventional three-electrode configuration. Furthermore, a two-electrode asymmetric supercapacitor (ASC) device was fabricated to assess the practical viability of this material. The α-Fe2O3/rGO NCs exhibited a remarkable potential window of 2 V in an aqueous electrolyte, coupled with exceptional cycling stability. Even after undergoing 10 000 cycles, the capacitive retention exceeded 100%, underlining the promising potential of this material for advanced energy storage applications.
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The kinetics of hydrogen oxidation and evolution by [FeFe]-hydrogenases have been investigated by electrochemical impedance spectroscopy-resolving factors that determine the exceptional activity of these enzymes, and introducing an unusual and powerful way of analyzing their catalytic electron transport properties. Attached to an electrode, hydrogenases display reversible electrocatalytic behavior close to the 2H+/H2 potential, making them paradigms for efficiency: the electrocatalytic "exchange" rate (measured around zero driving force) is therefore an unusual parameter with theoretical and practical significance. Experiments were carried out on two [FeFe]-hydrogenases, CrHydA1 from the green alga Chlamydomonas reinhardtii, which contains only the active-site "H cluster," and CpI from the fermentative anaerobe Clostridium pasteurianum, which contains four low-potential FeS clusters that serve as an electron relay in addition to the H cluster. Data analysis yields catalytic exchange rates (at the formal 2H+/H2 potential, at 0 °C) of 157 electrons (78 molecules H2) per second for CpI and 25 electrons (12 molecules H2) per second for CrHydA1. The experiments show how the potential dependence of catalytic electron flow comprises frequency-dependent and frequency-independent terms that reflect the proficiencies of the catalytic site and the electron transfer pathway in each enzyme. The results highlight the "wire-like" behavior of the Fe-S electron relay in CpI and a low reorganization energy for electron transfer on/off the H cluster.
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Hidrogênio/química , Hidrogenase/metabolismo , Catálise , Domínio Catalítico , Chlamydomonas reinhardtii/enzimologia , Clostridium/enzimologia , Espectroscopia de Ressonância de Spin Eletrônica , Transporte de Elétrons , Cinética , Modelos Moleculares , Conformação ProteicaRESUMO
The reasons for using enzymes as tools for solar fuels research are discussed. Many oxidoreductases, including components of membrane-bound electron-transfer chains in living organisms, are extremely active when directly attached to an electrode, at which they display their inherent catalytic activity as electrical current. Electrocatalytic voltammograms, which show the rate of electron flow at steady-state, provide direct information on enzyme efficiency with regard to optimising use of available energy, a factor that would have driven early evolution. Oxidoreductases have evolved to minimise energy wastage ('overpotential requirement') across electron-transport chains where rate and power must be maximised for a given change in Gibbs energy, in order to perform work such as proton pumping. At the elementary level (uncoupled from work output), redox catalysis by many enzymes operates close to the thermodynamically reversible limit. Examples include efficient and selective electrocatalytic reduction of CO2 to CO or formate - reactions that are very challenging at the chemistry level, yet appear almost reversible when catalysed by enzymes. Experiments also reveal the fleeting existence of reversible four-electron O2 reduction and water oxidation by 'blue' Cu oxidases, another reaction of great importance in realising a future based on renewable energy. Being aware that such enzymes have evolved to approach perfection, chemists are interested to know the minimal active site structure they would need to synthesise in order to mimic their performance.
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Hematite (α-Fe2O3) nanostructures have been extensively studied as photo-anodes for the conversion of sunlight into chemical fuels by water splitting. A number of factors limit the photo-activity of pristine hematite nanostructures, including poor electrical conductivity and long penetration depth of light. Previous studies have shown that use of tin (Sn) as an n-type dopant can substantially enhance the photoactivity of hematite photoanodes by modifying their morphological, optical and electrical properties. This article presents impedance spectroscopic investigation of interplay between Sn-doping and the photoanode performance for photoelectrochemical water splitting using hematite nanostructure. Mott-Schottky measurements show that the Sn dopant serves as electron donor and increases the donor density of Sn-doped α-Fe2O3 nanostructured layer to 2.39 × 1019 cm-3. Photoelectrochemical impedance spectroscopy shows efficient photogenerated charge transfer from hematite to electrolyte in Sn-doped α-Fe2O3 nanostructure. The Sn-doped α-Fe2O3 nanostructure exhibit a photocurrent density of 1.2 mA/cm2 at 1.4 V versus RHE electrode.
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In this article, the effect of copper (Cu) as a redox additive and dopant on the performance of a polyaniline (PANI) based supercapacitor was thoroughly investigated. The electrochemical properties of PANI in H2SO4 and in H2SO4 + CuSO4 and Cu doped PANI in H2SO4 were studied using cyclic voltammetry (CV) and impedance spectroscopy (IS). The CV result indicates that the capacity of PANI in H2SO4 was significantly improved with the introduction of Cu(2+) ions into the electrolyte, but it appeared unstable because of underpotential deposition of copper over the PANI surface and the relatively irreversible nature of the redox reaction. However, a stable and improved performance was obtained for Cu doped PANI due to the combined effect of an increase in conductivity and the surface modification of the PANI film. For Cu doped PANI, nearly â¼2.4 and â¼1.5 fold improved interfacial capacitance was achieved compared to that of PANI (H2SO4) and PANI (H2SO4 + CuSO4) respectively. The obtained Nyquist spectra for all the configurations were analysed using an equivalent circuit to understand the fundamentals of capacitive and resistive response of the supercapacitor. The IS measurements lead to direct determination of parameters like series resistance, rate capability of electrodes, ion diffusion phenomena and interfacial capacitance. The experimental results and their analysis will have significant impact on understanding the effect of dopants and redox additives on the performance of PANI based supercapacitors and also lay the basis for designing a supercapacitor with an appropriate electrode and electrolyte material for numerous industrial and consumer applications.
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The health benefits imparted by probiotics and prebiotics as well as synbiotics have been the subject of extensive research in the past few decades. These food supplements termed as functional foods have been demonstrated to alter, modify and reinstate the pre-existing intestinal flora. They also facilitate smooth functions of the intestinal environment. Most commonly used probiotic strains are: Bifidobacterium, Lactobacilli, S. boulardii, B. coagulans. Prebiotics like FOS, GOS, XOS, Inulin; fructans are the most commonly used fibers which when used together with probiotics are termed synbiotics and are able to improve the viability of the probiotics. Present review focuses on composition and roles of Probiotics, Prebiotics and Synbiotics in human health. Furthermore, additional health benefits like immune-modulation, cancer prevention, inflammatory bowel disease etc. are also discussed. Graphical abstractPictorial summary of health benefits imparted by probiotics, prebiotics and synbiotics.
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The present work reports a detailed electro-analytical framework for studying commercially available mono-crystalline silicon solar cells under varying illumination conditions to explore their application in the up-and-coming field of low concentration photovoltaics (LCPVs). The effect of low concentration illumination (>1-12 suns) on performance indicating parameters, i.e., short circuit current, open circuit voltage, fill factor, efficiency and ideality factor, was investigated using DC characterization. The same framework can be used for AC characterization in order to explore diffusion capacitance, transition capacitance, diffusion resistance and recombination kinetics under varying illumination. Recent developments in the impedance spectroscopy technique have broadened its horizon and have allowed its use in addressing unexplored material and performance aspects of mono-crystalline Si solar cells under non-equilibrium conditions. The obtained DC and AC experimental results are coupled with theoretical treatment to demonstrate the characteristic features of charge recombination in the space-charge region and the quasi-neutral region.
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This study provides a comprehensive analysis of a biofabricated nanomaterial derived from Sansevieria trifasciata root extract, evaluating its structural, morphological, and optical properties for use in asymmetric supercapacitors. The nanomaterial comprises pristine ZnO nanoparticles (ZnO NPs) and a 1% Ag-doped ZnO nanocomposite (Ag@ZnO NC), synthesized through a green-assisted sol-gel autocombustion method. Employing techniques such as X-ray diffraction, ultraviolet-visible near-infrared, scanning electron microscopy-energy-dispersive X-rayspectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and transmission electron microscopy, the study confirms a hexagonal wurtzite structure and nanocrystallites with spherical and hexagonal shapes (30 nm). Optical analysis reveals a red shift in the band gap with Ag doping, indicating improved conductivity. The material shows potential applications in solar cells, optoelectronics, spintronics, wastewater treatment, and high-performance asymmetric supercapacitors. Raman spectra validate the wurtzite phase and identify intrinsic defects. Electrochemical tests demonstrate remarkable supercapacitive behavior with a 94% capacitance retention after 10,000 cycles, highlighting its promise as advanced asymmetric supercapacitors.
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Natural ores are abundant, cost-effective, and environmentally friendly. Ultrathin (2D) layers of a naturally abundant van der Waals mineral, Biotite, have been prepared in bulk via exfoliation. We report here that this 2D Biotene material has shown extraordinary Li-Na-ion battery anode properties with ultralong cycling stability. Biotene shows 302 and 141 mAh g-1 first cycle-specific charge capacity for Li- and Na-ion battery applications with â¼90% initial Coulombic efficiency. The electrode exhibits significantly extended cycling stability with â¼75% capacity retention after 4000 cycles even at higher current densities (500-2000 mA g-1). Further, density functional theory studies show the possible Li intercalation mechanism between the 2D Biotene layers. Our work brings new directions toward designing the next generation of metal-ion battery anodes.
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BACKGROUND: The whole world has been severely affected due to the COVID-19 pandemic. The rapid and large-scale spread has caused immense pressure on the medical sector hence increasing the chances of false detection due to human errors and mishandling of reports. At the time of outbreaks of COVID-19, there is a crucial shortage of test kits as well. Quick diagnostic testing has become one of the main challenges. For the detection of COVID-19, many Artificial Intelligence based methodologies have been proposed, a few had suggested integration of the model on a public usable platform, but none had executed this on a working application as per our knowledge. OBJECTIVE: Keeping the above comprehension in mind, the objective is to provide an easy-to-use platform for COVID-19 identification. This work would be a contribution to the digitization of health facilities. This work is a fusion of deep learning classifiers and medical images to provide a speedy and accurate identification of the COVID-19 virus by analyzing the user's CT scan images of the lungs. It will assist healthcare workers in reducing their workload and decreasing the possibility of false detection. METHODS: In this work, various models like Resnet50V2 and Resnet101V2, an adjusted rendition of ResNet101V2 with Feature Pyramid Network, have been applied for classifying the CT scan images into the categories: normal or COVID-19 positive. RESULTS: A detailed analysis of all three models' performances have been done on the SARS-CoV-2 dataset with various metrics like precision, recall, F1-score, ROC curve, etc. It was found that Resnet50V2 achieves an accuracy of 96.79%, whereas Resnet101V2 achieves an accuracy of 97.79%. An accuracy of 98.19% has been obtained by ResNet101V2 with Feature Pyramid Network. As Res- Net101V2 with Feature Pyramid Network is showing better results, thus, it is further incorporated into a working application that takes CT images as input from the user and feeds into the trained model and detects the presence of COVID-19 infection. CONCLUSION: A mobile application integrated with the deeper variant of ResNet, i.e., ResNet101V2 with FPN checks the presence of COVID-19 in a faster and accurate manner. People can use this application on their smart mobile devices. This automated system would assist healthcare workers as well, which ultimately reduces their workload and decreases the possibility of false detection.
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COVID-19 , Aprendizado Profundo , Humanos , SARS-CoV-2 , Inteligência Artificial , PandemiasRESUMO
Background: Stress urinary incontinence (SUI) is a common ailment in affecting quality of life. This study was performed to see role of incontinence severity index (ISI) in evaluating severity of SUI and to see the impact of treatment of SUI. Materials and Methods: A total of 40 women with the diagnosis of SUI on history and clinical examination were enrolled. ISI was calculated on all the women before treatment. All women were treated with either conservative treatment (pelvic floor exercises, life style modification, and duloxetine therapy) (4, 10%) or Burch's colposuspension (18, 45%) or tension-free obturator tape (18, 45%) as per clinical situation after discussion with patients. ISI was again calculated 6 months after treatment. Results: Mean age, parity, body mass index in the study were 41.60 years, 2.73, and 24.2 kg/m2, respectively. All 40 (100%) patients had SUI with the mean duration of symptoms being 4.04 years. A total of 11 (27.5%) had moderate SUI (ISI 3-6), while 24 (60%) had severe SUI (ISI 8-9), while 5 (12.5%) had very severe SUI (ISI 12). Range of pretreatment ISI was 3-12 with mean being 8.8 ± 3.2. Posttreatment ISI reduced significantly with range of 1-4 and mean of 1.3 ± 0.4 (P < 0.001). The reduction was significant for all the groups, but there was no significant difference in efficacy of three treatment groups. Statistical analysis was done using SPSS IBM Version 2-1-0 using Chi-square test, Fisher's Extract test, and ANOVA test as appropriate. Conclusion: ISI is a useful modality to evaluate the severity of SUI and to see the impact of treatment modalities on SUI.
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Metagenomic analyses have revealed microbial dysbiosis in the gut of patients with colorectal cancer (CRC). The gut microbiota influences CRC via a variety of mechanisms, including microbial-derived factors such as metabolites or genotoxins. Pathogenic drivers and opportunistic passenger bacteria may underlie direct effect of the gut microbiota on carcinogenesis. We posit that metabolites generated by gut microbiota can influence CRC through a multitude of epigenetic or genetic effects on malignant transformation. A closer look at the cross talks between the commensals, epithelial cells, immune regulators etc., needs to be established with more substantiated studies. The recurrence of chemoresistant disease following therapy undoubtedly provides the impetus for morbidity and mortality; yet, the role of gut microbiome in drug resistance remains to be fully investigated. We review the current literature on microbial dysbiosis during CRC and discuss the mechanistic basis of CRC-associated bacteria in tumor initiation, progression and drug resistance.
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Much research addresses the proposition that identifying with a group shapes individuals' behaviour. Typically, such research employs experimental or survey methods, measuring or manipulating social identification and relating this to various outcome variables. Although shedding much light on the processes involved in the identity-behaviour relationship, such research tends to overlook the various constraints that limit individuals' abilities to act in accordance with their identities. Using interview data gathered in north India, we explore the factors affecting the enactment of a religious identity. More specifically, using data gathered at a religious mass gathering, we compare and contrast participants' reports of identity enactment when they are at the event and when they are in their home villages. These two contexts differ in terms of their social organization, especially the degree to which they are marked by the presence of a shared identity. Exploring participants' accounts of such differences in social organization, we consider the social processes that constrain or facilitate identity enactment. In so doing, our analysis contributes to a richer analysis of the identity-behaviour relationship.
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Férias e Feriados , Identificação Social , Humanos , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Posthysterectomy vault prolapse is a common problem after vaginal or abdominal hysterectomy. The objective was to assess the role of Pelvic Floor Distress Inventory 20 (PFDI-20) in evaluation of vault prolapse. MATERIALS AND METHODS: Prospective study in 20 women with posthysterectomy vault prolapse of Stage 2 and above. The outcome measure was to calculate PFDI-20 score in all cases before surgical intervention and to recalculate it again in 6 months after different surgical procedures for vault prolapse and to statistically compare the PFDI-20 score in different types of surgery over 4 years period at a tertiary referral hospital for surgical treatment. Prolapse was classified using Pelvic Organ Prolapse Quantification and intraoperative findings. All women were operated for vault prolapse as per hospital protocol and stage of prolapse by either vaginal sacrospinous fixation or abdominal sacrocolpopexy. RESULTS: Mean age, parity, and body mass index were 54.8 years, 3.5, and 22.71 kg/m2 respectively. Preceding surgery was vaginal hysterectomy in 75% women and abdominal hysterectomy in 25% women. Complaints were bulge or mass feeling at perineum (100%), pressure in lower abdomen and perineum (55%), and constipation (60%). The type of prolapse was vault prolapse (100%), cystocele (100%), rectocele (100%), and enterocele (45%). The range of PFDI-20 was 88-152 with mean being 123.50 ± 22.71 before surgery while its range decreased significantly to 80-126 with mean being 106.40 ± 16.45 after surgery (P < 0.01). Mean postoperative PFDI-20 score was 107.40 in vaginal sacrospinous fixation group and was 105.30 in abdominal sacrocolpopexy group and was not statistically different (P = 0.18). CONCLUSION: PFDI-20 score can be used to see the adverse impact of vault prolapse on pelvic floor and to assess the beneficial effect of different types of surgeries on the score.
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BACKGROUND: Urinary incontinence (UI) presents in over 50% menopausal women affecting their quality of life leading to depression and hence needs addressal and treatment as very few of them seek medical help. AIMS: Our aim was to determine the prevalence of depression, and the correlation of severity of UI with depression in incontinent women versus continent controls. METHODOLOGY: A cross-sectional case-control study of previously diagnosed 100 incontinent women (Stress/Urgency/Mixed) was done over a period of 3 months. The severity of UI was assessed on Patient Incontinence Severity Assessment (a form of Likert scale) and depression was assessed on a validated Patient Health Questionnaire-9 scale. STATISTICAL ANALYSIS: The statistical analysis was performed using SPSS version 19.0. RESULTS: Most of our cases were 51-60 years, with Urge UI being the most predominant (88%). Hundred percent of our incontinent patients were depressed, with 48% and 45% being severely and moderately severely depressed, respectively. A highly significant correlation was found between the severity of incontinence, amount of leakage, leaking pattern, and depression. CONCLUSION: All of our incontinent patients were depressed, with the severity of depression increasing with the severity of incontinence.
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BACKGROUND: Stress urinary incontinence (SUI) is involuntary leakage of urine on raised intra- abdominal pressure which adversely affects quality of life usually requiring surgical treatment. METHODS: This is a prospective study of efficacy, cure rates and complications of tension free transobturator tape (TOT) surgery on 85 women with SUI. Pre-operatively and 6 months post-operatively International consultation on Incontinence Questionnaire - Short Form (ICIQ-SF) scores were calculated for all patients to know the severity of incontinence and efficacy of tape. RESULTS: Mean age, parity, body mass index and mean duration of symptoms were 45.78 years, 2.68, 26.38 kg/m2 and 3.85 years, respectively. SUI was demonstrated in all cases on cough stress test and Bonney's test. Mean operative time, blood loss, post-operative analgesic injections, post- operative stay and post- operative catheterisation were 23.28 min, 45.50 ml, 1.2 injections, 1.2 days and 1.2 days. Various complications noted were excessive bleeding (3.52%), urinary retention (7.05%), urinary urgency (8.23%), urinary tract infection (2.35%), surgical site infection (1.17%), groin pain (28.23%) and mesh exposure (3.52%). At 6 months follow-up, the complete cure rate was 83.52% , partial cure rate was 11.76% and failure rate was found to be 4.70% whereas it was 79.16%, 12.0% and 8.33% respectively at 3 years follow up. 2 patients (2.35%) required burch colposuspension and 12 patients (14.11%) required pelvic floor exercises and duloxetine therapy for their symptoms. Mean pre- operative ICIQ-SF score reduced post- operatively (17.8 ± 4.67 to 2.71 ± 1.42) (p value = 0.001). CONCLUSION: Study demonstrates short and long-term efficacy and safety of TOT for surgical management of SUI.
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Centistidea acrocercopsi Ahmad & Pandey, sp. nov., C. cosmopteryxi Ahmad & Pandey, sp. nov., and C. tihamica Ghramh & Ahmad, sp. nov. are described as new to science. The genus Centistidea Rohwer (Hymenoptera: Braconidae: Miracinae) is recorded for the first time from Saudi Arabia. Two species were reared from Acrocercops phaeospora Meyrick and Cosmopteryx phaeogastra (Meyrick) in India, while Centistidea tihamica was collected by Malaise trap in Saudi Arabia. Characters of these new species and their affinities with related taxa are discussed. Data on habitat, host records, and host plant species for all the parasitoid species are also provided.
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Probiotics are microorganisms which when administered in adequate amounts confer health benefits to the host. A leading pharmaceutical company producing Bacillus coagulans as a probiotic was facing the problem of recurring phage attacks. Two mutants viz. B. co PIII and B. co MIII that were isolated as phage resistant mutants after UV irradiation and MMS treatment of phage sensitive B. coagulans parental culture were characterized at functional and molecular level and were noted to have undergone interesting genetic changes. The non-specific genetic alterations induced by mutagenesis can also lead to alterations in cell performance. Hence, in the current study the parental strain and the two mutants were selected for shake flask optimization. Plackett-Burman design was used to select the significant culture variables affecting biomass production. Evolutionary operation method was applied for further optimization. The study showed wide variations in the nutritional requirements of phage resistant mutants, post exposure to mutagens. An increment of 150, 134 and 152 % was observed in the biomass productions of B. coagulans (parental type) and mutants B.co PIII and B.co MIII respectively, compared to the yield from one-factor-at-a-time technique. Using Logistic and modified Leudeking-Piret equations, biomass accumulation and substrate utilization efficiency of the bioprocess were determined. The experimental data was in agreement with the results predicted by statistical analysis and modelling. The developed model may be useful for controlling the growth and substrate consumption kinetics in large scale fermentation using B. coagulans.
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In the present paper, the nature of electronic states and transport properties of nanostructured flower-like molybdenum disulphide grown by hydrothermal route has been studied. The band structure, electronic nature of charge, thermodynamics and the limit of phonon scattering through density functional theory (DFT) has also been studied. The band tail states, dynamics of trap states and transport of carriers was investigated through intensive impedance spectroscopy analysis. The direct fingerprint of density and band tail state is analyzed from the capacitance plot as capacitance reflects the capability of a semiconductor to accept or release the charge carriers with a corresponding change in its Fermi potential levels. A recently introduced infrared photo-carrier radiometry and density functional perturbation theory (DFPT) techniques have been used to determine the temperature dependence of carrier mobility in flower type-MoS2. The present study illustrates that a large amount of trapped charges leads to an underestimation of the measured effective mobility and the potential of the material. Thus, a continuous engineering effort is required to improve the quality of fabricated nanostructures for its potential applications.
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A field experiment was conducted to study the effect of different amendments of tannery sludge on physiological and biochemical parameters of tomato plant (Lycopersicon esculentum L. Mill). The accumulation of metals (Cr, Fe) in different parts of tomato plants grown on tannery sludge amended soil increased in a concentration and duration-dependent manner. The accumulation of both the metals was found lowest in the fruits of the plant. The statistical analysis of the results showed an increase in chlorophyll and protein contents in lower sludge amendment ratio at all exposures followed by a decrease at highest (100%) sludge amendment ratio. Lipid peroxidation enhanced in both root and leaves of sludge grown plants of tomato at all the sludge amendments and exposure periods, which is evidenced by increased malondialdehyde content, however the maximum increase was found in the roots (43.63%) and leaves (56.66%) of the plant grown on 100% tannery sludge at 60 d, over respective controls. The level of antioxidants, cysteine, non-protein thiol and ascorbic acid increased in the sludge grown plants of tomato to cope up with stress induced by the excess amount of the heavy metals present in the tannery sludge. The maximum increase was found in cysteine content (75.53% in the leaves), non-protein thiol content (92.68% in the roots) and ascorbic acid content (29.66% in the roots) of the plant at 75% tannery sludge after 30 d. The tomato plants were found well adopted for minimizing damage induced by reactive oxygen species, when grown on tannery sludge amendments in the present study.