Publications by authors named "Nidhi Tiwari"

21 Publications

  • Page 1 of 1

Health data from diaries used in low-income communities, north India.

Bull World Health Organ 2021 Jun 1;99(6):446-454. Epub 2021 Apr 1.

Lady Hardinge Medical College, New Delhi, India.

Objective: To determine the acceptability of keeping a self-written health diary among members of low-income communities, with the aim of generating needed health data.

Methods: We identified three different types of impoverished communities (tribal, inner-city slum and rural) in north India, and conducted a baseline survey to establish the sociodemographic properties of the members of 595 (tribal), 446 (slum) and 51 (rural) households. We designed health diaries with a single page to fill in per month, each with a carbon duplicate, and distributed diaries to willing participants. Health volunteers visited households each month to assist with diary completion and to collect duplicate pages for a period of one year. We compared the frequency of illnesses reported in health diaries with baseline survey data.

Findings: A total of 4881 diary users (tribal: 2205; slum: 2185; rural: 491) participated in our project. In terms of acceptability, 49.6% (1093/2205), 64.7% (1413/2185) and 79.0% (388/491) at the tribal, slum and rural sites, respectively, expressed satisfaction with the scheme and a willingness to continue. In the tribal and slum areas, we observed increased reporting of illnesses from health diaries when compared with baseline data. We observed that influenza-like illnesses were reported with the highest frequency of 58.9% (2972/5044) at the tribal site.

Conclusion: We observed high levels of acceptability and participation among the communities. From our initial field studies, we have observed the benefits to both our study participants (timely preventive education and referrals) and to service providers (obtaining health data to allow improved planning).
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http://dx.doi.org/10.2471/BLT.20.264325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8164179PMC
June 2021

Synthesis of pH-sensitive crosslinked guar gum-g-poly(acrylic acid-co-acrylonitrile) for the delivery of thymoquinone against inflammation.

Int J Biol Macromol 2021 May 12;182:1218-1228. Epub 2021 May 12.

Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University (A Central University), VidyaVihar, Raebareli Road, Lucknow, U.P. 226025, India. Electronic address:

The present work aims to synthesize the pH-sensitive crosslinked guar gum-g-poly(acrylic acid-co-acrylonitrile) [guar-g-(AA-co-ACN)] via microwave-assisted technique for the sustained release of thymoquinone. The synthesized material [guar-g-(AA-co-ACN)] was optimized by varying synthetic parameters viz. monomer concentration, reaction time, and microwave power to obtain the maximum yield of the crosslinked guar gum grafted product as well as maximum encapsulation of thymoquinone. The synthesized material [guar-g-poly(AA-co-ACN)] was characterized by FT-IR, SEM, XRD, NMR, zeta potential, and thermal techniques. This synthesized material was used to encapsulate thymoquinone (TQ) for effective nanotherapeutic delivery. In-vitro thymoquinone release behavior of guar-g-poly(AA-co-ACN) based nanoparticles (NpTGG) was investigated. The maximum thymoquinone release (78%) was achieved at pH 7.4 and time (6 h). The NpTGG also exhibited better antioxidant activity and hemocompatibility as compared to thymoquinone. Cytotoxicity of uar-g-(AA-co-ACN) and NpTGG was also evaluated against the human kidney VERO cell line and found to be nontoxic. Current research provides a cost-effective and green approach for the synthesis of guar-g-(AA-co-ACN) and NpTGG for sustained release of thymoquinone.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.05.072DOI Listing
May 2021

Osteosarcoma of jaws: Challenges in diagnosis.

J Oral Maxillofac Pathol 2020 Sep-Dec;24(3):589. Epub 2021 Jan 9.

Department of Oral Surgery, Government Dental College, Raipur, Chhattisgarh, India.

Osteosarcoma (OS) accounts for about 20% of all sarcomas with gnathic involvement seen in about 6%-10% of all OSs. The clinical presentation of OSs in the jaws is different from that of long bones as swelling is the most common complaint in patients with jaw OS followed by pain. The histopathologic variables seen are more favorable in OSs of jaws. Low-grade tumors are Stage I, high-grade tumors are Stage II and metastatic tumors (regardless of grade) are Stage III. A 17-year-old male patient reported with a complaint of the presence of an intra-oral growth gradually increasing in size in the right buccal mucosa region soft tissue enveloping the occlusal aspect of the right mandibular second molar. Extraorally swelling was present on the right side of the face for 4 months. Radiographically, there was a radiolucency from the distal aspect of right Mandibular second molar extending into the ramus region of the mandible with ill-defined borders. Hemi-mandibulectomy was done with the removal of the right mandible from the premolar region to condyle and coronoid processes. Microscopic evaluation of the sections after hematoxylin and eosin staining revealed interlacing fascicles of spindle-shaped cells arranged in a biphasic pattern and some areas of attempted bone formation evident in deeper sections. Tumor was an osteoblastic variety consisting of tumor osteoid surrounded by bizarrely arranged fibroblast-like cells. It showed positive staining with α-smooth muscle actin and Vimentin, suggesting a malignant tumor of mesenchymal cells with high myofibroblastic activity. Our case had small-cell histology; therefore, differential diagnosis was important.
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http://dx.doi.org/10.4103/jomfp.JOMFP_142_20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8083400PMC
January 2021

Mechanistic Insights into the Structural Stability of Collagen-Containing Biomaterials Such as Bones and Cartilage.

J Phys Chem B 2021 05 30;125(18):4757-4766. Epub 2021 Apr 30.

Centre of Biomedical Research, SGPGIMS Campus, Raebareli Road, Lucknow 226014, India.

Structural stability of various collagen-containing biomaterials such as bones and cartilage is still a mystery. Despite the spectroscopic development of several decades, the detailed mechanism of collagen interaction with citrate in bones and glycosaminoglycans (GAGs) in the cartilage extracellular matrix (ECM) in its native state is unobservable. We present a significant advancement to probe the collagen interactions with citrate and GAGs in the ECM of native bones and cartilage along with specific/non-specific interactions inside the collagen assembly at the nanoscopic level through natural-abundance dynamic nuclear polarization-based solid-state nuclear magnetic resonance spectroscopy. The detected molecular-level interactions between citrate-collagen and GAG-collagen inside the native bone and cartilage matrices and other backbone and side-chain interactions in the collagen assembly are responsible for the structural stability and other biomechanical properties of these important classes of biomaterials.
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http://dx.doi.org/10.1021/acs.jpcb.1c01431DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8151626PMC
May 2021

Dysregulation of Multiple Signaling Neurodevelopmental Pathways during Embryogenesis: A Possible Cause of Autism Spectrum Disorder.

Cells 2021 Apr 20;10(4). Epub 2021 Apr 20.

Department of Pharmacy, Mohammed Al-Mana College for Medical Sciences, Dammam 34222, Saudi Arabia.

Understanding the autistic brain and the involvement of genetic, non-genetic, and numerous signaling pathways in the etiology and pathophysiology of autism spectrum disorder (ASD) is complex, as is evident from various studies. Apart from multiple developmental disorders of the brain, autistic subjects show a few characteristics like impairment in social communications related to repetitive, restricted, or stereotypical behavior, which suggests alterations in neuronal circuits caused by defects in various signaling pathways during embryogenesis. Most of the research studies on ASD subjects and genetic models revealed the involvement of mutated genes with alterations of numerous signaling pathways like Wnt, hedgehog, and Retinoic Acid (RA). Despite significant improvement in understanding the pathogenesis and etiology of ASD, there is an increasing awareness related to it as well as a need for more in-depth research because no effective therapy has been developed to address ASD symptoms. Therefore, identifying better therapeutic interventions like "novel drugs for ASD" and biomarkers for early detection and disease condition determination are required. This review article investigated various etiological factors as well as the signaling mechanisms and their alterations to understand ASD pathophysiology. It summarizes the mechanism of signaling pathways, their significance, and implications for ASD.
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http://dx.doi.org/10.3390/cells10040958DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8074600PMC
April 2021

Experimental Rodent Models of Vascular Dementia: A Systematic Review.

CNS Neurol Disord Drug Targets 2021 Jan 8. Epub 2021 Jan 8.

Department of Epidemic Disease Research, Institute for Research & Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441. Saudi Arabia.

Vascular dementia (VaD) occurs due to cerebrovascular insufficiency, which leads to decreased blood circulation to the brain, thereby resulting in mental disabilities. The main causes of vascular cognitive impairment (VCI) are severe hypoperfusion, stroke, hypertension, large vessel disease (cortical), small vessel disease (subcortical VaD), strategic infarct, hemorrhage (microbleed), cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and cerebral amyloid angiopathy (CAA),which leads to decreased cerebrovascular perfusion. Many metabolic disorders such as diabetes mellitus (DM), dyslipidemia, and hyperhomocysteinemia are also related to VaD. The rodent experimental models provide a better prospective for the investigation of the molecular mechanism of new drugs. A plethora of experimental models are available that mimic the pathological conditions and lead to VaD. This review article updates the current knowledge on the basis of VaD, risk factors, pathophysiology, mechanism, advantages, limitations, and the modification of various available rodent experimental models.
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http://dx.doi.org/10.2174/1871527319666210108123438DOI Listing
January 2021

Novel β-Coronavirus (SARS-CoV-2): Current and future aspects of pharmacological treatments.

Saudi Pharm J 2020 Oct 27;28(10):1243-1252. Epub 2020 Aug 27.

Biotechnology Division, Council of Scientific & Industrial Research-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India.

The novel coronavirus outbreak has reported to be rapidly spreading across the countries and becomes a foremost community health alarm. At present, no vaccine or specific drug is on hand for the treatment of this infectious disease. This review investigates the drugs, which are being evaluated and found to be effective against nCOVID-19 infection. A thorough literature search was performedon the recently published research papers in between January 2020 to May 2020, through various databases like "Science Direct", "Google Scholar", "PubMed","Medline", "Web of Science", and "World Health Organization (WHO)". We reviewed and documented the information related with the current and future aspects for the management and cure of COVID-19. As of 21st July 2020 a total of 14,562,550 confirmed cases of coronavirus and 607,781 deaths have been reported world-wide. The main clinical feature of COVID-19 ranges from asymptomatic disease to mild lower respiratory tract illness to severe pneumonia, acute lung injury, acute respiratory distress syndrome (ARDS), multiple organ dysfunction, and death. The drugs at present used in COVID-19 patients and ongoing clinical trials focusing on drug repurposing of various therapeutic classes of drug e.g. antiviral, anti-inflammatory and/or immunomodulatory drugs along with adjuvant/supportive care. Many drugs on clinical trials shows effective results on preliminary scale and now used currently in patients. Adjuvant/supportive care therapy are used in patients to get the best results in order to minimize the short and long-term complications. However, further studies and clinical trials are needed on large scale of population to reach any firm conclusion in terms of its efficacy and safety.
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http://dx.doi.org/10.1016/j.jsps.2020.08.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7449930PMC
October 2020

Self healable neuromorphic memtransistor elements for decentralized sensory signal processing in robotics.

Nat Commun 2020 08 12;11(1):4030. Epub 2020 Aug 12.

School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.

Sensory information processing in robot skins currently rely on a centralized approach where signal transduction (on the body) is separated from centralized computation and decision-making, requiring the transfer of large amounts of data from periphery to central processors, at the cost of wiring, latency, fault tolerance and robustness. We envision a decentralized approach where intelligence is embedded in the sensing nodes, using a unique neuromorphic methodology to extract relevant information in robotic skins. Here we specifically address pain perception and the association of nociception with tactile perception to trigger the escape reflex in a sensorized robotic arm. The proposed system comprises self-healable materials and memtransistors as enabling technologies for the implementation of neuromorphic nociceptors, spiking local associative learning and communication. Configuring memtransistors as gated-threshold and -memristive switches, the demonstrated system features in-memory edge computing with minimal hardware circuitry and wiring, and enhanced fault tolerance and robustness.
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http://dx.doi.org/10.1038/s41467-020-17870-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7424569PMC
August 2020

Probing short and long-range interactions in native collagen inside the bone matrix by BioSolids CryoProbe.

Magn Reson Chem 2021 02 16;59(2):99-107. Epub 2020 Aug 16.

Centre of Biomedical Research, SGPGIMS Campus, Lucknow, 226014, India.

Solid-state nuclear magnetic resonance is a promising technique to probe bone mineralization and interaction of collagen protein in the native state. However, many of the developments are hampered due to the low sensitivity of the technique. In this article, we report solid-state nuclear magnetic resonance (NMR) experiments using the newly developed BioSolids CryoProbe™ to access its applicability for elucidating the atomic-level structural details of collagen protein in native state inside the bone. We report here approximately a fourfold sensitivity enhancement in the natural abundance C spectrum compared with the room temperature conventional solid-state NMR probe. With the advantage of sensitivity enhancement, we have been able to perform natural abundance N cross-polarization magic angle spinning (CPMAS) and two-dimensional (2D) H- C heteronuclear correlation (HETCOR) experiments of native collagen within a reasonable timeframe. Due to high sensitivity, 2D H/ C HETCOR experiments have helped in detecting several short and long-range interactions of native collagen assembly, thus significantly expanding the scope of the method to such challenging biomaterials.
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http://dx.doi.org/10.1002/mrc.5084DOI Listing
February 2021

Cerebral palsy: Aetiology, pathophysiology and therapeutic interventions.

Clin Exp Pharmacol Physiol 2020 12 19;47(12):1891-1901. Epub 2020 Aug 19.

Department of Pharmacology and Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Alkharj, Saudi Arabia.

Cerebral palsy (CP) is the most common non-progressive neurodevelopmental disorder in which the impairment of motor and posture functions occurs. This condition may be present in many different clinical spectra. Various aetiological and risk factors play a crucial role in the causation of CP. In various cases, the causes of CP may not be apparent. Interruption in the supply of oxygen to the fetus or brain asphyxia was considered to be the main causative factor explaining CP. Antenatal, perinatal, and postnatal factors could be involved in the origin of CP. Understanding its pathophysiology is also crucial for developing preventive and protective strategies. A major advancement in the brain stimulation techniques has emerged as a promising status in diagnostic and interventional approaches. This review provides a brief explanation about the various aetiological factors, pathophysiology, and recent therapeutic approaches in the treatment of cerebral palsy.
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http://dx.doi.org/10.1111/1440-1681.13379DOI Listing
December 2020

Role of inflammatory markers in corona virus disease (COVID-19) patients: A review.

Exp Biol Med (Maywood) 2020 09 7;245(15):1368-1375. Epub 2020 Jul 7.

Department of Pharmacology & Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Alkharj 11942, Saudi Arabia.

Impact Statement: In late 2019, a novel virus called SARS-CoV-2, expanded globally from Wuhan, China and was declared a pandemic on 11 March 2020 by the WHO. The mechanism of virus entry inside the host cell depends upon the cellular proteases including cathepsins, HAT, and TMPRSS2, which splits up the spike protein and causes further penetration. MERS coronavirus uses DPP4, while coronavirus HCoV-NL63 and SARS-CoV and SARS-CoV-2 employ ACE-2 as the key receptor. Cytokine storm syndrome was analyzed in critically ill nCOVID-19 patients and it is presented with high inflammatory mediators, systemic inflammation, and multiple organ failure. Among various inflammatory mediators, the level of interleukins (IL-2, IL-7, IL-10), G-CSF, MIP1A, MCP1, and TNF-α was reported to be higher in critically ill patients. Understanding this molecular mechanism of ILs, T cells, and dendritic cells will be helpful to design immunotherapy and novel drugs for the treatment of nCOVID-19 infection.
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http://dx.doi.org/10.1177/1535370220939477DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7441343PMC
September 2020

Optogenetics inspired transition metal dichalcogenide neuristors for in-memory deep recurrent neural networks.

Nat Commun 2020 06 25;11(1):3211. Epub 2020 Jun 25.

School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.

Shallow feed-forward networks are incapable of addressing complex tasks such as natural language processing that require learning of temporal signals. To address these requirements, we need deep neuromorphic architectures with recurrent connections such as deep recurrent neural networks. However, the training of such networks demand very high precision of weights, excellent conductance linearity and low write-noise- not satisfied by current memristive implementations. Inspired from optogenetics, here we report a neuromorphic computing platform comprised of photo-excitable neuristors capable of in-memory computations across 980 addressable states with a high signal-to-noise ratio of 77. The large linear dynamic range, low write noise and selective excitability allows high fidelity opto-electronic transfer of weights with a two-shot write scheme, while electrical in-memory inference provides energy efficiency. This method enables implementing a memristive deep recurrent neural network with twelve trainable layers with more than a million parameters to recognize spoken commands with >90% accuracy.
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http://dx.doi.org/10.1038/s41467-020-16985-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7316775PMC
June 2020

Water-lipid interactions in native bone by high-resolution solid-state NMR spectroscopy.

Solid State Nucl Magn Reson 2020 06 22;107:101666. Epub 2020 Apr 22.

Centre of Biomedical Research, SGPGIMS Campus, Raebarelly Road, Lucknow, 226014, India. Electronic address:

The study of structural and dynamical properties of lipid and its associated interaction with different components of bone is essential to understand its role at a different level of bone homeostasis such as bone mineralization and bone metabolism. In this article, we present water-dependent dynamical changes observed in lipids (triglycerides) in its absolute native environment inside bone by high-resolution H solid-state nuclear magnetic resonance spectroscopy (ssNMR). Relaxation measurement (T measurement) ssNMR experiments were performed at different levels of water network induced by dehydration and H/D exchange in native bone. Our measurements reflect the changes in the local environment and dynamical properties of triglyceride due to different hydration levels. The present study explains the role of water in stabilizing the structural properties of triglycerides in bone hence will help understand its pathological role associated with bone physiology and bone disorders.
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http://dx.doi.org/10.1016/j.ssnmr.2020.101666DOI Listing
June 2020

Field-Driven Athermal Activation of Amorphous Metal Oxide Semiconductors for Flexible Programmable Logic Circuits and Neuromorphic Electronics.

Small 2019 Jul 23;15(27):e1901457. Epub 2019 May 23.

School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.

Despite extensive research, large-scale realization of metal-oxide electronics is still impeded by high-temperature fabrication, incompatible with flexible substrates. Ideally, an athermal treatment modifying the electronic structure of amorphous metal oxide semiconductors (AMOS) to generate sufficient carrier concentration would help mitigate such high-temperature requirements, enabling realization of high-performance electronics on flexible substrates. Here, a novel field-driven athermal activation of AMOS channels is demonstrated via an electrolyte-gating approach. Facilitating migration of charged oxygen species across the semiconductor-dielectric interface, this approach modulates the local electronic structure of the channel, generating sufficient carriers for charge transport and activating oxygen-compensated thin films. The thin-film transistors (TFTs) investigated here depict an enhancement of linear mobility from 51 to 105.25 cm V s (ionic-gated) and from 8.09 to 14.49 cm V s (back-gated), by creating additional oxygen vacancies. The accompanying stochiometric transformations, monitored via spectroscopic measurements (X-ray photoelectron spectroscopy) corroborate the detailed electrical (TFT, current evolution) parameter analyses, providing critical insights into the underlying oxygen-vacancy generation mechanism and clearly demonstrating field-induced activation as a promising alternative to conventional high-temperature annealing strategies. Facilitating on-demand active programing of the operation modes of transistors (enhancement vs depletion), this technique paves way for facile fabrication of logic circuits and neuromorphic transistors for bioinspired computing.
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http://dx.doi.org/10.1002/smll.201901457DOI Listing
July 2019

Thorium decorporation efficacy of rationally-selected biocompatible compounds with relevance to human application.

J Hazard Mater 2019 03 13;365:952-961. Epub 2018 Nov 13.

Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India. Electronic address:

During civil, nuclear or defense activities, internal contamination of actinides in humans and mitigation of their toxic impacts are of serious concern. Considering the health hazards of thorium (Th) internalization, an attempt was made to examine the potential of ten rationally-selected compounds/formulations to decorporate Th ions from physiological systems. The Th-induced hemolysis assay with human erythrocytes revealed good potential of tiron, silibin (SLB), phytic acid (PA) and Liv.52 (L52) for Th decorporation, in comparison to diethylenetriaminepentaacetic acid, an FDA-approved decorporation drug. This was further validated by decorporation experiments with relevant human cell models (erythrocytes and liver cells) and biological fluid (blood) under pre-/post-treatment conditions, using inductively coupled plasma mass spectrometry (ICP-MS) and transmission electron microscopy (TEM). Furthermore, density functional theory-based calculations and extended X-ray absorption fine structure (EXAFS) spectroscopy confirmed the formation of Th complex by these agents. Amongst the chosen biocompatible agents, tiron, SLB, PA and L52 hold promise to enhance Th decorporation for human application.
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http://dx.doi.org/10.1016/j.jhazmat.2018.11.038DOI Listing
March 2019

Ultralow Power Dual-Gated Subthreshold Oxide Neuristors: An Enabler for Higher Order Neuronal Temporal Correlations.

ACS Nano 2018 11 5;12(11):11263-11273. Epub 2018 Nov 5.

School of Materials Science and Engineering , Nanyang Technological University , 50 Nanyang Avenue , Singapore 639798.

Inspired by neural computing, the pursuit of ultralow power neuromorphic architectures with highly distributed memory and parallel processing capability has recently gained more traction. However, emulation of biological signal processing via artificial neuromorphic architectures does not exploit the immense interplay between local activities and global neuromodulations observed in biological neural networks and hence are unable to mimic complex biologically plausible adaptive functions like heterosynaptic plasticity and homeostasis. Here, we demonstrate emulation of complex neuronal behaviors like heterosynaptic plasticity, homeostasis, association, correlation, and coincidence in a single neuristor via a dual-gated architecture. This multiple gating approach allows one gate to capture the effect of local activity correlations and the second gate to represent global neuromodulations, allowing additional modulations which augment their plasticity, enabling higher order temporal correlations at a unitary level. Moreover, the dual-gate operation extends the available dynamic range of synaptic conductance while maintaining symmetry in the weight-update operation, expanding the number of accessible memory states. Finally, operating neuristors in the subthreshold regime enable synaptic weight changes with high gain while maintaining ultralow power consumption of the order of femto-Joules.
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http://dx.doi.org/10.1021/acsnano.8b05903DOI Listing
November 2018

Arsenic surface complexation behavior in aqueous systems onto Al substituted Ni, Co, Mn, and Cu based ferrite nano adsorbents.

J Hazard Mater 2019 01 29;361:383-393. Epub 2018 Sep 29.

Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur, 208016, India; Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016, India. Electronic address:

The present study is about surface complexation behavior of arsenic species adsorbed onto ternary metal oxide adsorbents (Ni-Al-Fe, Co-Al-Fe, Mn-Al-Fe, and Cu-Al-Fe). The analysis is carried out by X-ray absorption spectroscopy (XAS) tool. XANES (μ(E) vs. E) spectra close to the absorption edge (i.e., As K-edge) of all samples are observed along with the As(III) and As(V) standards. The first derivative of XANES for Ni-As(V), and Cu-As(V) samples agree with that of As(V) standards, respectively. Whereas, As(III) adsorbed adsorbent systems (i.e., Ni, Co, Mn, and Cu) are observed with mixed oxidation state of arsenic. A total of 65-85 % is observed with initial oxidation state (As(III) or As(V)), and remaining 15-35 % is observed with modified oxidation state (As(V) or As(III)) that explains the occurrence of possible charge transfer. EXAFS analysis shows the As-O bond distances in the range of 1.7-1.8 Å. The corresponding As-M bond distances are around 2.7, 3.2, and 3.6 Å which confirms the formation various edge sharing (E), and corner sharing (C, V) surface complexes. Surface coverage is understood as an important parameter as bidentate attachments (E, C) are evident in As(III), and As(V), but monodentate attachments (V) are only observed in As(V).
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http://dx.doi.org/10.1016/j.jhazmat.2018.07.056DOI Listing
January 2019

Indium Tungsten Oxide Thin Films for Flexible High-Performance Transistors and Neuromorphic Electronics.

ACS Appl Mater Interfaces 2018 Sep 31;10(36):30506-30513. Epub 2018 Aug 31.

Thin-film transistors (TFTs) with high electrical performances (mobility > 10 cm/V s, V < 1 V, SS < 1 V/decade, on/off ratio ≈ 10) obtained from the silicon- and oxide-based single-crystalline semiconductor materials require high processing temperature and hence are not suitable for flexible electronics. Amorphous oxide-based transparent electronic devices are attractive to meet emerging technological demands where crystalline oxide-/silicon-based architectures cannot provide a solution. Here, we tackle this problem by using a novel amorphous oxide semiconducting material-namely, indium tungsten oxide (IWO)-as the active channel in flexible TFTs (FTFTs). Post-annealing temperature as low as 270 °C for amorphous IWO thin films deposited by radio frequency sputtering at room temperature could result in smooth morphology ( R ≈ 0.42 nm), good adhesion, and high carrier density ( n ≈ 7.19 × 10 cm). Excellent TFT characteristics of flexible devices could be achieved with linear field effect mobility μ ≈ 25.86 cm/V s, subthreshold swing SS ≈ 0.30 V/decade, threshold voltage V ≈ -1.5 V, and on/off ratio I/ I ≈ 5.6 × 10 at 3 V and stable operation during bending of the FTFT. Additionally, IWO TFTs were implemented as synapses, the building block for neuromorphic computing. Paired-pulse facilitation up to 138% was observed and showed an exponential decay resembling chemical synapses. Utilizing this characteristic, a high-pass dynamic temporal filter was devised providing increased gain from 1.55 to 21 when frequency was raised from 22 to 62 Hz. The high performance and stability of flexible TFTs obtained with IWO films demonstrate their promise for low-voltage electronic applications.
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http://dx.doi.org/10.1021/acsami.8b06956DOI Listing
September 2018

Potential of carnosine, a histamine precursor in rat model of bilateral common carotid artery occlusion-induced vascular dementia.

Fundam Clin Pharmacol 2018 Oct 23;32(5):516-531. Epub 2018 May 23.

Pharmacology Division, Department of Pharmaceutical Sciences and Drug Research, Faculty of Medicine, Punjabi University, Patiala, 147002, Punjab, India.

The present study investigates the potential of Carnosine, a histamine precursor in rat model of bilateral common carotid artery occlusion (BCCAo)-induced vascular dementia (VaD). Wistar rats were subjected to BCCAo procedure under anaesthesia to induce VaD. The rats were subjected to Morris water maze (MWM) test (6th day onwards post-surgery). MWM test was employed to assess learning and memory of the animals whereby escape latency time, time spent in target quadrant and Path length (distance travelled) taken as important parameters. Serum nitrite level; Brain thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) levels; Brain acetylcholinesterase (AChE) activity; brain Myeloperoxidase activity (MPO) and neutrophil count were estimated as per standard procedures. BCCAo in rats produced a significant vascular endothelial dysfunction, as reflected by decrease in serum nitrite levels. Further, these animals showed poor performance on MWM, depicting impairment of learning and memory. There was a significant rise in brain oxidative stress level as indicated by increase in TBARS and decrease in GSH levels. An increase in brain AChE activity was also observed. Moreover, these rats also exhibited an increase in MPO activity and neutrophil infiltration in brain (as marker of inflammation). Treatment of Carnosine (200 and 400 mg/kg, i.p.)/Donepezil (0.3 mg/kg, i.p.) ameliorated BCCAo-induced memory deficits; endothelial dysfunction; biochemical and histopathological changes. It is concluded that Carnosine has shown efficacy in rat model of BCCAo-induced VaD and can be considered as an important therapeutic agent for the treatment of VaD.
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http://dx.doi.org/10.1111/fcp.12376DOI Listing
October 2018

Synthesis and Biological Activities of Oxadiazole Derivatives: A Review.

Mini Rev Med Chem 2016 ;16(10):825-45

Department of Pharmaceutical Sciences, Dr. H.S. Gour University, Sagar, 470003, Madhya Pradesh, India.

Recently, there has been wide interest in compounds containing the oxadiazole scaffold because of their unique chemical structure and their broad spectrum of biological properties. This review provides readers with an overview of the main synthetic methodologies for oxadiazoles and of their broad spectrum of pharmacological activities such as, anti-microbial, anti-fungal activity, antiviral, anti-tubercular, anti-inflammatory, anti-convulsant, anti-angiogenic, anti-proliferative, analgesic, anti-oedema and in alzheimer activity, which were reported over the past years.
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http://dx.doi.org/10.2174/1389557516666160211120835DOI Listing
February 2017

Unique selectivity reversal in Am(3+)-Eu(3+) extraction in a tripodal TREN-based diglycolamide in ionic liquid: extraction, luminescence, complexation and structural studies.

Dalton Trans 2016 Feb 22;45(6):2476-84. Epub 2015 Dec 22.

Laboratory of Molecular Nanofabrication, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

An N-pivot diglycolamide extractant (DGA-TREN) was synthesized for the first time and its complexation behaviour was studied towards trivalent lanthanide/actinide ions. The solvent extraction studies suggested a unique selectivity reversal in the extraction of trivalent actinides versus trivalent lanthanides which was observed performing extraction studies in an ionic liquid vis-à-vis a molecular diluent for a tripodal TREN-based diglycolamide ligand (DGA-TREN) vs. a tripodal diglycolamide ligand (T-DGA) which may have great significance in radioactive waste remediation. The nature of the bonding to Eu(3+) ion was investigated by EXAFS as well as by DFT calculations.
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http://dx.doi.org/10.1039/c5dt04729cDOI Listing
February 2016