73 research outputs found

    Origin of multiple band gap values in single width nanoribbons

    Get PDF
    Deterministic band gap in quasi-one-dimensional nanoribbons is prerequisite for their integrated functionalities in high-performance molecular-electronics based devices. However, multiple band gap values commonly observed in the same width of graphene nanoribbons fabricated in same slot of the experiments remains unresolved, and raise a critical concern over scalable production of pristine and/or hetero-structure nanoribbons with deterministic properties and functionalities for plethora of applications. Here, we show that a modification in the depth of potential wells in the periodic direction of a supercell on relative shifting of passivating atoms at the edges is the origin of multiple band gap values for the same width of nanoribbons in a crystallographic orientation, although they carry practically the same ground state energy. The results are similar when calculations are extended from planar graphene to buckled silicene nanoribbons. Thus, the findings facilitate tuning of the electronic properties of quasi-one-dimensional materials such as bio-molecular chains, organic and inorganic nanoribbons by performing edge engineering.Comment: 11 pages, 6 figure

    Dentofacial and Cranial Changes in Down Syndrome

    Get PDF
    AbstractObjectivesThis study aimed to determine the prevalence of certain oral characteristics usually associated with Down syndrome and to determine the oral health status of these patients.MethodsThe cross-sectional study was conducted among patients attending a special education program at Faculty of Dentistry, Jamia Millia Islamia, Delhi, India. The study design consisted of closed-ended questions on demographic characteristics (age, sex, and education and income of parents), dietary habits, and oral hygiene habits. Clinical examination included assessment of oral hygiene according to Simplified Oral Hygiene Index (OHI-S), dental caries according to decayed, missing, and filled teeth (DMFT) index, periodontal status according to the Community Periodontal Index of Treatment Needs (CPITN), and malocclusion according to Angles classification of malocclusion. Examinations were carried out using a using a CPI probe and a mouth mirror in accordance with World Health Organization criteria and methods. Craniometric measurements, including maximum head length and head breadth were measured for each participant using Martin spreading calipers centered on standard anthropological methods.ResultsThe majority of the patients were males (n = 63; 82%) with age ranging from 6–40 years. The Intelligence Quotient (IQ) score of the patients indicated that 31% had moderate mental disability and 52% had mild mental disability. 22% exhibited hearing and speech problems.12% had missing teeth and 15% had retained deciduous teeth in adult population. The overall prevalence of dental caries in the study population was 78%. DMFT, CPITN and OHI scores of the study group were 3.8 ± 2.52, 2.10 ± 1.14 and 1.92 ± 0.63 respectively. The vast majority of patients required treatment (90%), primarily of scaling, root planing, and oral hygiene education. 16% of patients reported CPITN scores of 4 (deep pockets) requiring complex periodontal care. The prevalence of malocclusion was 97% predominantly of Class III malocclusions. Further 14% presented with fractured anterior teeth primarily central incisor. The percentage means of cephalic index was 84.6% in the study population. The brachycephalic and hyperbrachycephalic type of head shape was dominant in the Down syndrome individuals (90%).ConclusionThe most common dentofacial anomaly seen in these individuals was fissured tongue followed by macroglossia

    Expression of transforming growth factor ? and its correlation with lipodystrophy in oral submucous fibrosis: an immunohistochemical study

    Get PDF
    Objective: In our routine review of Oral Submucous Fibrosis (OSMF) biopsies, we observed decreased adipose tissue even though most are from buccal mucosa. Pathogenesis of OSMF has demonstrated the role of Transforming Growth Factor ? (TGF ?), in causing fibrosis. This study aims to correlate the role of TGF ? with loss of adipose tissue in OSMF. Study Design: From our archives, 84 OSMF cases (24 early and 60 advanced OSMF) were screened for adipose tissue. Immunoexpression of TGF ? in these cases were investigated. Results: Adipose tissue was seen in 67% of early OSMF and in 13% of advanced cases. Early cases showed more intense TGF ? staining of epithelium, fibroblast, macrophages and inflammatory cells than the advanced cases. Conclusion: These findings suggest that TGF ? plays a key role in causing lipodystrophy in OSMF and is secreted more during early course of the disease than in advanced stage

    Preparation and Characterization of Celecoxib Entrapped Guar Gum Nanoparticles Targeted for Oral Drug Delivery against Colon Cancer: An In-Vitro Study

    Get PDF
    The present study is an attempt to synthesize nanosized guar gum carriers encapsulating celecoxib as the chemopreventive agent for experimental colorectal cancer (CRC).  Guar gum nanoparticles without celecoxib (eGGNPs) and celecoxib loaded guar gum nanoparticles (cGGNPs) were prepared by oil-in-water emulsification and in situ polymer crosslinking method. Electron microscopy, zeta potential and fourier transform infrared spectra analysis was used to affirm the size, stability and morphology of the nanoparticles. In-vitro drug release was investigated using dialysis method. Further, the effect of nanoparticles (eGGNPs & cGGNPs) was evaluated on Caco 2 colon cancer cell lines. Spherical guar gum nanoparticles were obtained in the size range of 200±6nm with zeta potential of -32.1mV indicating good stability of the GGNPs with drug loading of 30±3.2%, and drug release following zero order kinetics. The eGGNPs had no effect on Caco2 cell viability whereas the cGGNPs showed time and concentration dependent growth inhibition of Caco 2 cells. These findings suggest the successful preparation of chemopreventive nanoparticles that can be targeted as the prophylactic agent for experimental colorectal cancer. Keywords: nanoparticles, guar gum, celecoxib, colorectal cancer, release kinetics, cytotoxicit

    Formulation Development and Evaluation of Herbal Toothpaste for Treatment of Oral Disease

    Get PDF
    Streptococcus mutans is the most common cause of tooth decay. Parabens and other commonly used as anti-Streptococcus agents in toothpaste industry have numerous side effects such as discoloration of teeth. The herbal extract of all three plants gives antimicrobial and anti-inflammatory activity and prevent and reducing the tooth decay, dental caries and given to freshness of mouth. The aim of present work was development and evaluation of herbal antimicrobial toothpaste containing Bark of Acacia nilotica, Acacia catechu and flower buds of syzygium aromaticum as herbal ingredients. Different types of formulations (F1-F6) were formulated using calcium carbonate as abrasive and Glycerine as humectant in varied concentrations. All the formulations were evaluated for various parameters like dryness, color, appearance, consistency, washability, pH, spreadability and foaming power. Polyherbal toothpaste containing hydroalcoholic extract of plants was tested for antimicrobial activity against Staphylococcus aureus and Streptococcus mutans with different concentrations of toothpaste were used (25, 50and 100 mg/ml). Among the tested bacteria used Staphylococcus aureus was found to be most sensitive to the formulated toothpaste as seen by zone of inhibition (19-24 mm) followed by Streptococcus mutans (13-18 mm). The results showed that the formulated polyherbal toothpaste is promising antimicrobial effects against both organisms. It may be safer compared to fully synthetic toothpaste. Further studies are warranted to prove safety and efficacy of the formulated polyherbal toothpaste. Keywords: Streptococcus mutans, Acacia nilotica, Acacia catechu, syzygium aromaticum, polyherbal toothpast

    FAULT DIAGNOSIS OF INDUCTION MOTOR USING PLC

    Get PDF
    ABSTRACT: Induction motors are used in many industrial applications in a wide range of operating areas as they have simple and robust structure, and low production costs. Induction motors are now being used more as compared to before due to their certain advantages such as versatility, dependability and economy, good self-starting capability, offers users simple, rugged construction easy maintenance, low cost and reliability. The reliability of an induction motor is of great Importance in industrial as well as commercial, aerospace and military applications. Also the knowledge about fault mode behavior of an induction motor drive system is extremely important from the standpoint of improved system design, protection, and fault tolerant control. [1] In this paper different problems are dealt, such as overvoltage, over current , over temperature, over speed, inrush current, vibration monitoring which are being faced by IM's during it's course of operation. There are various methods for fault detection and protection of IM. Some of them are On-line fault detection, Stator fault monitoring techniques, Microcontrollers based protection system and Programmable Logic Controller (PLC) based protection system. In this study, the method used is PLC based protection system of IM

    Comparison of seven modelling algorithms for γ-aminobutyric acid–edited proton magnetic resonance spectroscopy

    Get PDF
    Edited MRS sequences are widely used for studying γ-aminobutyric acid (GABA) in the human brain. Several algorithms are available for modelling these data, deriving metabolite concentration estimates through peak fitting or a linear combination of basis spectra. The present study compares seven such algorithms, using data obtained in a large multisite study. GABA-edited (GABA+, TE = 68 ms MEGA-PRESS) data from 222 subjects at 20 sites were processed via a standardised pipeline, before modelling with FSL-MRS, Gannet, AMARES, QUEST, LCModel, Osprey and Tarquin, using standardised vendor-specific basis sets (for GE, Philips and Siemens) where appropriate. After referencing metabolite estimates (to water or creatine), systematic differences in scale were observed between datasets acquired on different vendors' hardware, presenting across algorithms. Scale differences across algorithms were also observed. Using the correlation between metabolite estimates and voxel tissue fraction as a benchmark, most algorithms were found to be similarly effective in detecting differences in GABA+. An interclass correlation across all algorithms showed single-rater consistency for GABA+ estimates of around 0.38, indicating moderate agreement. Upon inclusion of a basis set component explicitly modelling the macromolecule signal underlying the observed 3.0 ppm GABA peaks, single-rater consistency improved to 0.44. Correlation between discrete pairs of algorithms varied, and was concerningly weak in some cases. Our findings highlight the need for consensus on appropriate modelling parameters across different algorithms, and for detailed reporting of the parameters adopted in individual studies to ensure reproducibility and meaningful comparison of outcomes between different studies.publishedVersio
    corecore