50 research outputs found

    Exchange Mechanisms in Macroscopic Ordered Organic Magnetic Semiconductors

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    Small molecule organic semiconductors such as phthalocyanines and their derivatives represent a very interesting alternative to inorganic semiconductor materials for the development of flexible electronic devices such as organic thin field effect transistors, organic Light Emitting Diodes and photo-voltaic cells. Phthalocyanine molecules can easily accommodate a variety of metal atoms as well in the central core of the molecule, resulting in wide range of magnetic properties. Exploration of optical properties of organic crystalline semiconductors thin films is challenging due to sub-micron grain sizes and the presence of numerous structural defects, disorder and grain boundaries. However, this can be overcome by fabricating macroscopically ordered semiconductor films by solution processing. Presence of fewer grain boundaries and defects while modifying the pi orbital overlap by controlling the molecular stacking by forming macroscopic long range ordered grains, was essential in understanding the delocalization and diffusion length and its role in magnetic exchange mechanisms in this system. The origins of magnetic exchange mechanism between delocalized ligand electrons and spins in organic semiconductors has been of key interest as it underlies many complex optical and transport properties and is investigated in this thesis. The interaction between magnetic ions in organic magnetic semiconductors is quite challenging to interpret due to competing exchange mechanisms present in crystalline thin films. Better understanding of these exchange mechanisms is essential for tuning of magnetic exchange interaction to suit the need of practical magnetic storage and spintronic devices. Optical techniques such as linear dichroism, magnetic circular dichroism and magneto-photoluminescence are used and provided key understanding about the relation between excitons, spin exchange mechanisms and collective magnetic behavior of delocalized electrons in organic semiconductors. An enhancement in the collective magnetization of the crystalline thin films with strong exchange coupling between the delocalized ligand electrons and d-electrons is observed. The electronic states responsible for magnetic exchange are identified utilizing magnetic field and temperature dependent studies. Furthermore, soluble organics allowed engineering of organic analogues to diluted magnetic semiconductors (DMS) by creation of metal/metal-free Pc alloys. Optical studies provided crucial information about delocalization and diffusion lengths in these systems allowing fine tuning of this delocalization length scale and metal-metal distance. The exploration of magnetic behavior in metal/metal-free Pc alloys opens an avenue for tuning magnetic properties through an exchange similar to Ruderman-Kittel-Kasuya Yosida (RKKY) type interaction in organic magnetic semiconductors

    Advancing The Ability To Predict Cognitive Decline and Alzheimer’s Disease Based On Genetic Variants Beyond Amyloid-beta and Tau

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    A growing amount of neurodegenerative R&D is focused on identifying genomic- based explanations of AD that are beyond Amyloid-b and Tau. The proposed effort involves identifying some of the genomic variations, such as single nucleotide polymorphisms (SNPs), allele , chromosome, epigenetic contributors to MCI and AD that are beyond Aβ and Tau. The project involves building a prediction model based on a support vector machine (SVM) classifier that takes into account the genomic variations and epigenetic factors to predict the early stage of mild cognitive impairment (MCI) and Alzheimer disease (AD). To achieve this, picking up important feature sets which will be input to the machine learning model were identified using statistical model tests. The data used in this research were obtained from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database / ADNI GO2 GWAS. Future work may involve increase in sample size analyzed from ADNI DB, explore and analyze potential secondary effects/medical-conditions such as other diseases that might have influenced the observed results and separate out MCI from AD and further explore predictions and results

    Effect of Nanostructure on the Thermal Oxidation of Atomized Iron

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    The effect of nanostructure on the thermal oxidation of atomized iron has been investigated. Above 500oC atomized iron is oxidized in the presence of air. However, when iron is compacted with multiwalled carbon nanotubes (MWCNT) this oxidation is shifted by more than 100oC. Iron is protected by the nanostructure environment A large number of compositions of atomic ratios of iron and MWCNT have been examined in this study to understand the effect in detail. The effect of nanostructure in the thermal oxidation of iron is interpreted as due to iron atom experiencing extensive overlap and confinement effect causing spin transfer. Based on the theoretical calculations reported in the literature this confinement effect of iron is suggested to produce a transformation from 3d64s2 to an effective configuration of 3d84s0 producing spintronics effect. (Refer to PDF file for exact formulas)

    A cross-sectional survey of orthopaedicians to understand the prescribing pattern of disease modifying osteoarthritis drugs in osteoarthritis

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    Background: Numerous dietary supplements with disease-modifying action are available in Indian market. However, doctor’s preferences for these disease modifying osteoarthritis drugs (DMOADs) to prevent progression of OA are not known. The objective of this study was to quantify doctor preferences for potential DMOADs.Methods: The survey instrument (online survey questionnaire at survey monkey) was developed by researchers upon review of existing literature and detailed discussion with practicing clinicians. Face and content validity and reliability (test-retest method) was assessed through a focused panel of clinicians to determine if content was adequate to obtain the necessary data. This was a cross-sectional digital survey of 207 orthopaedicians during Indian Orthopaedic Association Conference-2018 organized at Coimbatore.Results: NSAIDs + DMOAD combinations were the most preferred treatment option for newly diagnosed OA patients. 44% orthopaedicians prefer to start the treatment with combination of NSAID and DMOAD as compared to 10% with paracetamol monotherapy. Glucosamine/chondroitin combinations are the most commonly preferred DMOAD by the orthopaedicians; followed by undenatured type II collagen. 66% of the doctors surveyed opined that the efficacy of undenatured type-II collagen is better as compared to other DMOADs.Conclusions:The findings from the survey suggest that majority of orthopaedicians prefer to prescribe NSAID with DMOAD combinations for newly diagnosed osteoarthritis patients.

    Clinical Features Present, Past & Future Prospective of Monkey Pox: A Orthopoxvirus

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    Some issues regarding the potential spread of monkeypox have arisen just as the international world is beginning to recover from the initial alarm that was caused by the probable spread of coronavirus disease 2019 (COVID-19). Despite the fact that parts of Africa have traditionally been more susceptible to monkeypox than other regions of the world, the majority of new cases that have been linked to the outbreak that began in 2022 have been reported in countries located in Europe and the western hemisphere. Despite the fact that a great number of organisations are working on contact-tracing activities at the moment, the origin of this outbreak is still unknown at this time. The monkeypox virus belongs to the family of viruses known as Poxviridae and the genus known as Orthopoxvirus. Following the eradication of smallpox across the globe in the 1970s, news of monkeypox caused widespread worry across the globe. Through vaccination with the smallpox virus, individuals were able to develop cross-immunity against monkeypox. After distribution of the smallpox vaccine was discontinued, the number of outbreaks of monkeypox rose. The monkeypox epidemic that occurred in the United States in 2003 was the first time that the disease gained extensive notice in the media. In spite of its name, the virus known as monkeypox is not transmitted by monkeys. Although a number of different kinds of rodents and other small mammals have been suggested as the primal hosts of the monkeypox virus, the virus\u27s true lineage is still a mystery. The virus that causes monkeypox was first identified in macaque monkeys, which is where the disease was first seen. When monkeypox does transfer from one person to another, it often does so through a person\u27s mucocutaneous lesions or through the respiratory droplets that they expel. However, this only happens very infrequently. However, supporting therapy can be given to reduce symptoms, and medications such tecovirimat may be administered in really severe cases. At this time, there is no specific treatment for patients who have infected the virus; however, supportive treatments can be given. It is debatable whether or not these treatments are successful in reducing symptoms because there are no concrete guidelines to follow in this regard

    Spin Exchange Interaction in Substituted Copper Phthalocyanine Crystalline Thin Films

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    All rights reserved. The origins of spin exchange in crystalline thin films of Copper Octabutoxy Phthalocyanine (Cu-OBPc) are investigated using Magnetic Circular Dichroism (MCD) spectroscopy. These studies are made possible by a solution deposition technique which produces highly ordered films with macroscopic grain sizes suitable for optical studies. For temperatures lower than 2K, the contribution of a specific state in the valence band manifold originating from the hybridized lone pair in nitrogen orbitals of the Phthalocyanine ring, bears the Brillouin-like signature of an exchange interaction with the localized d-shell Cu spins. A comprehensive MCD spectral analysis coupled with a molecular field model of a σπ-d exchange analogous to sp-d interactions in Diluted Magnetic Semiconductors (DMS) renders an enhanced Zeeman splitting and a modified g-factor of -4 for the electrons that mediate the interaction. These studies define an experimental tool for identifying electronic states involved in spin-dependent exchange interactions in organic materials

    Schedule of Factors Influencing Adherence (SOFIA) to Psychiatric Treatment in Persons with Schizophrenia: Validity and Pilot Testing

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    Qualitative research has highlighted the complex interplay of multiple factors that preclude persons with schizophrenia in rural Indian settings for discontinued psychiatric treatment. In this context, this paper aims to establish the face and content validities of an interview schedule titled „Schedule of Factors Influencing Adherence (SOFIA) to Psychiatric Treatment in Persons with Schizophrenia‟ which comprehensively assesses factors for discontinued psychiatric treatment and the feasibility of its administration of the schedule. SOFIA contains 16 factors. This schedule involves three phases of interviewing patients and family members. This was given to twelve experts who used likert scales to rate each items wells as the dimensions of the schedule. Later on, fifteen persons with schizophrenia were interviewed with SOFIA to test the feasibility of administration. The results showed that Fourteen items were rated as either satisfactory (score=4) or very much satisfactory (score=5) by all twelve experts; remaining two were rated as 4 or 5 by 11 experts. Regarding comprehensiveness of the factors, scoring methods and general instructions given to the interviewers, all provided scores > 4; regarding method of interviewing, 11 provided score of > 4; with regard to overall interview schedule, all experts provided scores > 4. Pilot testing revealed that it took 60 minutes to administer SOFIA

    Malnutrition among under Five Children in Uttarakhand

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    BACKGROUND: Globally more than one third of child deaths are attributable to under nutrition. Eighty percent of the world’s undernourished children live in 20 countries, with India being home to nearly 60 million children who are underweight. OBJECTIVE: This study aimed to assess malnutrition among under five children in a selected hospital of Dehradun, Uttarakhand. METHODOLOGY: A quantitative research approach was used with descriptive cross-sectional research design. Non probability convenient sampling technique was used to select 70 under five children who fulfilled the inclusion criteria. The data collection tools included Socio -demographic profile and Anthropometric assessment of the children. The data was analyzed based on objectives by using descriptive and inferential statistics. Data was analyzed using WHO anthroplus software and SPSS 21.0. RESULT: The result showed that out of 70 children 17.14% showed mild wasting, 18.57% showed moderate wasting and (21.43%) showed severe wasting. 11.43% children showed mild stunting, moderate stunting was present in 15.71% children and severe stunting was present in 27.14% children. 31.43% children were moderately underweight and 30% were severely underweight. CONCLUSION: The study concluded that majority of the children were malnourished

    Schedule of Factors Influencing Adherence (SOFIA) to Psychiatric Treatment in Persons with Schizophrenia: Validity and Pilot Testing

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    Qualitative research has highlighted the complexinterplay of multiple factors that preclude persons withschizophrenia in rural Indian settings for discontinuedpsychiatric treatment. In this context, this paper aims toestablish the face and content validities of an interviewschedule titled „Schedule of Factors InfluencingAdherence (SOFIA) to Psychiatric Treatment in Personswith Schizophrenia‟ which comprehensively assessesfactors for discontinued  psychiatric treatment and   thefeasibility of its administration of the schedule. SOFIAcontains 16 factors. This schedule involves three phases of interviewing patients and family members.  This wasgiven to twelve experts who used likert scales to rate eachitems wells as the dimensions of the schedule. Later on,fifteen persons with schizophrenia were interviewed withSOFIA to test the feasibility of administration. The resultsshowed that Fourteen items were rated as eithersatisfactory (score=4) or very much satisfactory (score=5)by all twelve experts; remaining two were rated as 4 or 5by 11 experts. Regarding comprehensiveness of thefactors, scoring methods and general instructions given tothe interviewers, all provided scores > 4; regardingmethod of interviewing, 11 provided score of > 4; withregard to overall interview schedule, all experts providedscores > 4. Pilot testing revealed that it took 60 minutes to administer SOFIA

    First light preparations of the 4m ILMT

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    peer reviewedThe 4m International Liquid Mirror Telescope (ILMT) is a zenith-pointing optical observing facility at ARIES Devasthal observatory (Uttarakhand, India). The first light preparatory activities of the ILMT were accomplished in April 2022 followed by on-sky tests that were carried out at the beginning of May 2022. This telescope will perform a multi-band optical (SDSS g′g', r′r' and i′i') imaging of a narrow strip (~22′22') of sky utilizing the time-delayed integration technique. Single-scan ILMT images have an integration time of 102 sec and consecutive-night images can be co-added to further improve the signal-to-noise ratio. An image subtraction technique will also be applied to the nightly recorded observations in order to detect transients, objects exhibiting variations in flux or position. Presently, the facility is in the commissioning phase and regular operation will commence in October 2022, after the monsoon. This paper presents a discussion of the main preparation activities before first light, along with preliminary results obtained
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