Auswahl der wissenschaftlichen Literatur zum Thema „J P Narayan“

Microneedles are small-scale devices that may be used for access to interstitial fluid and/or capillary blood for transdermal monitoring of chemicals [1]. In this presentation, the integration of several types of electrochemical sensors with hollow microneedles will be considered. For example, carbon fiber electrodes have been integrated with digital micromirror device-produced microneedles; ascorbic acid and hydrogen peroxide were detected with these devices [2]. Carbon paste electrodes have also been integrated with digital micromirror device-produced microneedles; electrodes made from rhodium-dispersed carbon paste were used for hydrogen peroxide sensing [3]. In addition, lactate oxidase-modified rhodium-dispersed carbon paste electrodes were demonstrated for lactate sensing, including in the presence of interferents such as ascorbic acid, uric acid, and acetaminophen. A multiplexed microneedle array containing digital micromirror device-produced microneedles was subsequently used for amperometric detection of glucose, lactate, and pH; detection of these analytes in complex media was shown [4]. More recently, digital micromirror device-produced hollow microneedles were modified with a working sensor, which was prepared with graphene ink and 4 (3-Butyl-1-imidazolio)-1-butanesulfonate) ionic liquid. Direct oxidation of fentanyl via square-wave voltammetry was shown; a detection limit of 27.8 μM was demonstrated using this approach [5]. Two photon polymerization has also been used to create hollow microneedles for biosensing; a porous carbon electrode created using interference lithography was used for potassium ion sensing in the presence of interfering sodium ions [6]. In another study, nitrogen-incorporated ultrananocrystalline diamond coatings were deposited on Ti –6Al–4V alloy microneedles using microwave plasma enhanced chemical vapor deposition; dopamine and uric acid were electrochemically detected in an in vitro study [7]. These studies indicate that microneedles may have utility for minimally invasive detection of analytes in a real time manner. Benefits and disadvantages of the microneedle-based sensing approach as well as efforts needed for clinical translation of microneedle-based sensing technology will be considered. References [1] Miller PR, Narayan RJ, Polsky R. Microneedle-based sensors for medical diagnosis. Journal of Materials Chemistry B. 2016;4:1379-1383. [2] Miller PR, Gittard SD, Edwards TL, Lopez DM, Xiao X, Wheeler DR, Monteiro-Riviere NA, Brozik SM, Polsky R, Narayan RJ. Integrated carbon fiber electrodes within hollow polymer microneedles for transdermal electrochemical sensing. Biomicrofluidics. 2011;5:013415. [3] Windmiller JR, Zhou N, Chuang MC, Ramírez GV, Santhosh P, Miller PR, Narayan R, Wang J. Microneedle array-based carbon paste amperometric sensors and biosensors. Analyst. 2011;136:1846-1851. [4] Miller PR, Skoog SA, Edwards TL, Lopez DM, Wheeler DR, Arango DC, Xiao X, Brozik SM, Wang J, Polsky R, Narayan RJ. Multiplexed microneedle-based biosensor array for characterization of metabolic acidosis. Talanta. 2012;88:739–742. [5] Joshi P, Riley PR, Mishra R, Azizi Machekposhti S, Narayan R. Transdermal polymeric microneedle sensing platform for fentanyl detection in biofluid. Biosensors. 2022 Mar 27;12:198. [6] Miller PR, Xiao X, Brener I, Burckel DB, Narayan R, Polsky R. Microneedle-based transdermal sensor for on-chip potentiometric determination of K+. Advanced Healthcare Materials. 2014;3:876-881. [7] Skoog SA, Miller PR, Boehn RD, Sumant AV, Polsky R, Narayan RJ. Nitrogen-incorporated ultrananocrystalline diamond microneedle arrays for electrochemical biosensing. Diamond and Related Materials. 2015;54:39-46.

ABSTRACT Soon after tooth extraction the bone resorption takes place reducing the height and width of alveolar ridge. This produces an altered morphology of the bone unfavorable for implant placement and implant placement becomes impossible without surgical correction. Socket grafting maintains and preserves ridge for implant placement. How to cite this article Mahesh L, Narayan TV, Bali P, Shukla S. Socket Preservation with Alloplast: Discussion and a Descriptive Case. J Contemp Dent Pract 2012;13(6):934-937.

Aims: To derive an expression for change in entropy of spinning black holes on the basis of the model for the energy of spinning black holes ( Mahto et al. 2011a) & the model for entropy change ( Mahto et al. 2011b) and then calculate their values for different test spinning black holes. Study Design: Data for the mass of black holes have collected from the research paper entitled :Super massive Black Holes in Galactic Nuclei: Past Present & Future Research(2005), Space Science Reviews by L. Ferrarese & H. Ford and Black holes in Astrophysics(2005), New Journal Physics by R. Narayan. The data for black hole constant for spinning black holes () is taken from the paper entitled: Study of Schwarzschild radius with reference to the spinning black holes. Bulletin of Pure and Applied Sciences (2011a). Place and Duration of Study: Department of Physics, Marwari College Bhagalpur and University Department of Physics, T.M.B.U. Bhagalpur, between December 2013 and March 2014. Methodology: A theoretical based work using Laptop to calculate the calculation for change in entropy of different test spinning black holes at Marwari College Bhagalpur and the residential research chamber of the first author. Results: The calculation shows that the change in entropy of spinning black holes of the rest masses for stellar – mass black holes (M ~ 5 ­ 20 Mʘ) in X-ray binaries is to J/K and for the super massive black holes (M ~ 106 – 109.5 Mʘ) in active galactic nuclei is to J/K. The nature of the graph for XRBs is the same to the Hawking entropy with the event horizon and straight line for AGN which confirms the validity of equations and . Conclusion: The change in energy and entropy of black holes are mainly dependent on the mass and independent of their event horizons.

Healthcare education and practice has significantly been impacted by COVID-19. This includes the challenge on pedagogical approaches that highlight the potential of technology to facilitate innovative new approaches in response to social distancing, lockdowns, remote learning and improving the patient experience and positive outcomes. Many of these innovative approaches are not fundamentally new but are now seeing relevance beyond early adopters to mainstream implementation. This presentation draws upon collaborations with educational researchers and technologists that have explored the integration of technology into healthcare education and practice. COVID-19 Adversity to Opportunity Many healthcare programmes required reenvisaging teaching and learning approaches in response to COVID-19 restrictions. This had a particular impact on the development of interpersonal and practical knowledge and skills essential for healthcare graduates. The limited access to on-campus learning provided an opportunity for both institutional and individual evaluation of pedagogical practices. The affordances of traditional, didactic, and “hands-on” skills were compared with those that could be facilitated using online asynchronous/ synchronous strategies. A particular concern was the development of the interpersonal and practical skills required in safe and effective healthcare practice. Alongside easing of restrictions, these skills were adapted using online demonstrations within the limits of socially distanced “bubbles”, telehealth and limited clinical placements. Reconsideration of summative assessments was also required- with the introduction online synchronous and asynchronous verbal assessments, and asynchronous submissions of practical skills online (Cochrane et al., 2021; Narayan et al., 2021). In the prospect of COVID-19 restrictions continuing to lift, it is envisioned that most of the reenvisaged pedagogical approaches to healthcare education will persist, without compromising student critical thinking or practical skills. Interprofessional Collaboration This presentation will highlight the importance of interprofessional collaboration in healthcare curriculum design using a Design-Based-Research methodology (Chen et al., 2020; Kartoğlu et al., 2020) to facilitate authentic learning and develop self-determined learning capabilities for healthcare professionals. DBR- Design Principles in response to COVID Transferable design principles will be introduced for enhancing healthcare education that will improve practice in a COVID19 world, particularly drawing from eight healthcare projects including: STUDIO602 – enhancing clinical practice with mobile technologies (Cochrane & Sinfield, 2021), developing a virtual reality handover experience for healthcare students (Cochrane et al., 2018), using immersive reality to develop critical thinking in clinical health education (Stretton et al., 2018), enhancing first responder clinical simulation education using immersive reality and biometrics (Cochrane et al., 2020), designing authentic learning for graduate entry nursing students (Macdiarmid et al., 2021), designing public and environmental health education (Kersey et al., 2018), Biomedical engineering (Lam et al., 2021), and physiology education (Fabris et al., 2019). References Chen, W., Sandars, J., & Reeves, T. C. (2020). Navigating complexity: The importance of design-based research for faculty development. Medical Teacher, 1-3. https://doi.org/10.1080/0142159X.2020.1774530 Cochrane, T., Aiello, S., Cook, S., Aguayo, C., & Wilkinson, N. (2020). MESH360: A framework for designing MMR enhanced Clinical Simulations [Journal]. Research in Learning Technology, 28(Mobile Mixed Reality - Themed Collection). https://doi.org/10.25304/rlt.v28.2357 Cochrane, T., Narayan, V., Aiello, S., Birt, J., Cowie, N., Cowling, M., Deneen, C., Goldacre, P., Alizadeh, M., Sinfield, D., Stretton, T., & Worthington, T. (2021, 29th November- 1st December 2021). Post Pandemic Socially Constructed Blended Synchronous Learning: Vignettes from the Mobile Learning SIG. ASCILITE 2021: 38th International Conference on Innovation, Practice and Research in the Use of Educational Technologies in Tertiary Education, University of New England (UNE), Armidale, Australia. Cochrane, T., & Sinfield, D. (2021). STUDIO602: A model for designing real world collaborations between Higher education and Industry. In K. MacCallum & D. Parsons (Eds.), Industry Practices, Processes and Techniques Adopted in Education - Supporting innovative teaching and learning practice (Vol. In preparation). Springer. http://davidparsons.ac.nz/industry-in-ed/ Cochrane, T., Stretton, T., Aiello, S., Britnell, S., Cook, S., & Narayan, V. (2018). Authentic Interprofessional Health Education Scenarios using Mobile VR [Journal]. Research in Learning Technology, 26, 2130. https://doi.org/10.25304/rlt.v26.2130 Fabris, C. P., Rathner, J. A., Fong, A. Y., & Sevigny, C. P. (2019). Virtual Reality in Higher Education. International Journal of Innovation in Science and Mathematics Education (formerly CAL-laborate International), 27(8). Kartoğlu, Ü., Siagian, R. C., & Reeves, T. C. (2020). Creating a "Good Clinical Practices Inspection" Authentic Online Learning Environment through Educational Design Research. TechTrends : for leaders in education & training, 1-12. https://doi.org/10.1007/s11528-020-00509-0 Kersey, K., Lees, A., Conn, C., Cochrane, T., Narayan, V., & Williams, M. (2018). “Context matters”: The challenges and opportunities of designing tertiary public and environmental health education in South Auckland. Pacific Health, 1(1), 1-12. https://doi.org/https://doi.org/10.24135/pacifichealth.v1i1.8 Lam, L., Cochrane, T., Rajagopal, V., Davey, K., & John, S. (2021). Enhancing student learning through trans-disciplinary project-based assessment in bioengineering. Pacific Journal of Technology Enhanced Learning, 3(1), 4-5. https://doi.org/10.24135/pjtel.v3i1.80 Macdiarmid, R., Winnington, R., Cochrane, T., & Merrick, E. (2021). Using educational design research to develop authentic learning for Graduate Entry Nursing students in New Zealand. Nurse Education in Practice, 102965. https://doi.org/10.1016/j.nepr.2021.102965 Narayan, V., Cochrane, T., Aiello, S., Birt, J., Cowie, N., Cowling, M., Deneen, C., Goldacre, P., Alizadeh, M., Sinfield, D., Stretton, T., & Worthington, T. (2021, 29 November - 1 December). Mobile learning and socially constructed blended learning through the lens of Activity Theory. ASCILITE 2021: 38th International Conference on Innovation, Practice and Research in the Use of Educational Technologies in Tertiary Education, University of New England (UNE), Armidale, Australia. Stretton, T., Cochrane, T., & Narayan, V. (2018). Exploring Mobile Mixed Reality in Healthcare Higher Education: A Systematic Review [Journal]. Research in Learning Technology, 26, 2131. https://doi.org/10.25304/rlt.v26.2131

ABSTRACT Reconstruction of the post-burn contracture is a complex task in plastic surgery. A burn patient treated traditionally only by dressings develops scar with contracture involving the burned region. The lip is a part of the face that is frequently affected by burn injury. Post-burn scar sequelae in this area often result in cosmetic disfigurement and psychological upset in patients. Microstomia poses difficulty in airway intubation during anesthesia and contracture of the neck if present confounds difficulty. Reconstruction of post-burn oral commissure aims to restore both symmetry of the lips (esthetic) and full oral competence (functional). Frequently treated in our department, we present a case series of post-burn contracture of neck with microstomia whose neck extension and mouth opening both were restricted giving less option but more challenge for both anesthesiologists and plastic surgeons. How to cite this article Narayan N, Dhanraj P, Mahesh MS. Reconstruction of Post-burn Microstomia: Our Experience. J Health Sci Res 2015;6(1):5-7.

ABSTRACT Purpose Several antiplaque agents are being available in the market in spite of vast development of modern medical science, satisfactory treatment of ‘oral diseases’ by newer drugs is not fully achieved, rather the chemical compounds has exposed the patients to it is different ill effects, therefore, there is interest to find out effective remedy of any disease by harmless herbal drugs thus the aim of this study was to compare plaque formation at 24 hours after the use of Triphala, Hi ora, Chlorhexidine and colgate plax mouth washes. Methods A controlled, randomized, double-blind, crossover clinical trial was designed. Thirty subjects underwent four consecutive experimental phases with four treatments: Triphala, Hi Ora, Chlorhexidine and colgate plax. On the day of study, the subjects discontinued all other oral hygiene habits and were randomly assigned for treatment with the experimental mouthwash. Each experimental phase was preceded by a 28- day washout period. Plaque formation was recorded after one undisturbed day. Results Triphala, Hi Ora and Chlorhexidine reduced de novo plaque formation to a greater extent than the colgate plax mouthwash (p < 0.05). Conclusion Triphala and Hi Ora presents an anti-plaque efficacy similar to that of chlorhexdine, and was more effective at inhibiting plaque formation than the colgate plax mouth wash. How to cite this article Narayan A, Mendon C. Comparing the Effect of Different Mouthrinses on de novo Plaque Formation. J Contemp Dent Pract 2012;13(4):460-463.

BackgroundSleep disorders are prevalent in rheumatoid arthritis (RA). Sleep is closely related to disease activity, depression, stress, fatigue and pain [1]. Community prevalence of sleep disorders in India varies from 6.2% to 36.3% [2,3]. Studies assessing sleep quality in the Indian population with RA are limited.ObjectivesTo assess the prevalence of impaired sleep quality using Pittsburgh Sleep Quality Index (PSQI) and determine factors predicting impaired sleep quality in patients with RA.MethodsA cross-sectional study was conducted in patients with RA presenting to our rheumatology clinic after informed consent and Ethics Committee approval from January 2021. Sleep quality was assessed by PSQI, depression by Patient Health Questionnaire (PHQ-9) and Quality of life by Indian Health Assessment Questionnaire (IHAQ). Disease activity was assessed using Disease Activity Index (DAS28 CRP) and Clinical Disease Activity Index (CDAI). Serum samples for interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) were collected and stored at -800C. Relationship of fatigue was examined with age, serum TNF-α, IL-1, IL-6, CDAI, DAS28 CRP and patient global assessment (PtGA) using Spearman correlation coefficient. Linear regression analysis was performed to determine the predictors of impaired sleep quality in patients with RA.ResultsOne hundred and fifty-four patients were enrolled, 133 were females (86.3%). Median pain VAS score was 6[2]. Mean DAS was 4.35 ± 1.31, mean CDAI: 19.75 ± 7.91 and median IHAQ was 9.5[8]. The prevalence of depression (PHQ-9 >10) was 5.8% (n = 9) with a median PHQ-9 of 2[3]. One patient was on tofacitinib, 20 were on methotrexate monotherapy and others were on combination of conventional DMARDs.The prevalence of impaired sleep (PSQI >5) was 8.4% (n = 13) with a median PSQI of 2[2]. PSQI had significant correlation with PHQ-9 (r = 0.471, p<0.0001), IHAQ (r = 0.288, p<0.0001), DAS28 (r = 0.197, p = 0.015) and CDAI (r = 0.235 p = 0.003). Age, pain VAS, serum TNF-α, IL-1 and IL-6 had no correlation with PSQI. Among individual components of DAS, PtGA (r = 0.296 p <0.0001) alone correlated with PSQI. PHQ-9, IHAQ and PtGA were significant predictors of impaired sleep quality (Table 1).ConclusionCompared to other studies within India, our patients had very low prevalence of impaired sleep quality. Sleep quality significantly influences disease activity likely by affecting PtGA. Risk factors for poor sleep quality are presence of depression, poor quality of life and patient global assessment of disease activity. Hence a holistic management of RA must involve addressing these risk factors.Table 1.Predictors of impaired sleep qualityPredictorsβ (95% CI)P valuePtGA0.176(0.023 - 0.412)0.004Depression (PHQ-9)0.282 (0.101 - 0.342)<0.0001IHAQ0.230 (0.025 -.129)0.004References[1] McBeth J, Dixon WG, Moore SM, Hellman B, James B, Kyle SD, et al. Sleep Disturbance and Quality of Life in Rheumatoid Arthritis: Prospective mHealth Study. J Med Internet Res. 2022 Apr 22;24(4):e32825.[2] Ramaswamy G, Premarajan KC, Kar SS, Narayan SK, Thekkur P. Prevalence and determinants of sleep disorders in a community in rural southern India. Natl Med J India. 2020 May 1;33:132.[3] Panda S, Taly AB, Sinha S, Gururaj G, Girish N, Nagaraja D. Sleep-related disorders among a healthy population in South India. Neurol India. 2012 Jan 1;60(1):68.AcknowledgementsNone.Disclosure of InterestsNone Declared.

ABSTRACT Introduction The ultimate success of fixed prosthesis is to pay meticulous attention to the detailed production of the missing tooth structure. Such an accurate replication is technically demanding. Hence, the aim of the study was to evaluate the accuracy of marginal fit of castings with varying sprue diameter and using ring and ringless techniques. Materials and methods Forty standardized wax copings were fabricated on a stainless steel die and divided into two groups. The first group was cast using the metal ring investment technique; the second group was cast using the ringless investment technique. Both the groups were further divided into two groups, each based on the diameter of the sprue (groups I and III: 4.5 mm and groups II and IV: 2.5 mm). The vertical marginal gap was measured at three sites per specimen, using a digital optical microscope at ×100 magnification. The results were analyzed using two-way analysis of variance and independent t-test to determine statistical significance. Results The vertical marginal gaps of castings fabricated using the ringless technique (0.145 ± 0.072 mm) were significantly less (p < 0.001) than those castings fabricated using the conventional metal ring technique (0.264 ± 0.100 mm); however, the vertical marginal gaps of the 2.5 mm sprue diameter (0.199 ± 0.092 mm) and 4.5 mm sprue diameter (0.211 ± 0.118 mm) castings were not statistically significant (p > 0.05). There was also statistically significant interaction (p < 0.001) between group IIA (0.120 ± 0.038 mm) and group IA (0.302 ± 0.098 mm), which was analyzed using the independent t-test. Conclusion It can be concluded that the ringless casting technique in comparison to metal ring technique produces metal castings of better marginal adaptation. Furthermore, the sprue diameter had significant difference wherein the 4.5 mm diameter produced the least vertical discrepancies in the ringless casting technique and 2.5 mm produced lesser vertical discrepancies in the metal ring. Clinical significance One of the key factors that decides the success of a metal-ceramic restoration is the marginal fit. The accurate fit of the restoration greatly minimizes the plaque accumulation, offers good mechanical properties, and reduces micro-leakage and development of secondary caries. The techniques of casting procedure and sprue diameter can have an influence on the outcome. Hence, the current research was undertaken to study the influence of these factors on marginal fit. How to cite this article Dutta T, George VT, Balakrishnan D, Narayan AI. An in vitro Comparative Study to evaluate the Marginal Fit of Castings using Ring and Ringless Casting Techniques with Varying Sprue Diameter. World J Dent 2017;8(2):109-113.

Morphological instability of the lithium-electrolyte interface is a critical problem limiting the development of lithium-metal negative electrodes for batteries. At high current densities approaching the diffusion-limited current density, dendrites form due to depletion of Li+ ions near the electrode surface (1). At lower current densities, unstable deposition produces whiskers (2). Whiskers are separated by typically several micrometers, and in contrast to dendrites grow by addition of Li atoms to their base or "root" (3). Experimental evidence indicates that whisker growth is fed by large-scale interface or grain boundary diffusion, and that whiskers relieve compressive stress in the metal generated by electrodeposition (4-7). The present study proposes that Li electrodeposition is destabilized by interface diffusion driven by compressive stress due to incorporation of Li atoms at grain boundaries. The competition between stress and stabilizing surface energy effects generates a surface pattern which determines (in part) whisker sites. A morphological instability model is formulated based on the Asaro-Tiller-Grinfel'd (ATG) surface instability on elastically stress solids (8). The model applies to deposits less than 1 micron thick for which elastic deformation is expected to dominate (9,10). The Li electrode is depicted by a three-layer elastic model consisting of a stress-free substrate (current collector) layer, a Li layer with uniform diffusion-induced in-plane stress, and top layer. The top layer can simulate submicron thickness solid-electrolyte interface (SEI) layers, or macroscopically thick polymer separators and solid electrolytes. The Li-top layer interface deforms by diffusion. Out-of-plane normal stress is included to simulate the effect of applied stress on the instability (11,12). For model calculations, the interface stress was estimated from neutron-depth-profiling measurements of Li diffusion into Cu current collectors (13). The measured Li incorporation was found to be consistent with a whisker spacing of several microns, in agreement with experimental results (3,6,14). Calculations showed that the instability is inhibited significantly by the use of substrates with elastic modulus much greater than that of Li. This substrate stiffness effect is consistent with experimental observations of Sn whiskers (15). The effect of a stress-free SEI layer on the instability was found to be negligible, due to its small thickness. Whisker growth was suppressed by macroscopically thick top layers with elastic modulus at least 10 times that of Li. No significant whisker inhibition was found at applied stress levels of ~ 1 MPa, which are found experimentally to stabilize deposition in Li films significantly exceeding 1 micron thickness (11,12). This effect may be due to an instability associated with viscoplastic rather than elastic deformation (16). REFERENCES P. Bai et al., Energy Environ. Sci., 9, 3221(2016). L Frenck et al., Front. Energy Res., 7, 115 (2016) A. Kushima et al., Nano Energy, 32, 271 (2017). J. H. Cho et al., Energy Storage Mater., 24, 281 (2020). X. Wang et al., Nat. Energy, 3, 227 (2018). A. A. Rulev et al., J. Phys. Chem. Lett., 11, 10511 (2020). E. Chason et al., Prog. Surf. Sci., 88, 103 (2013). B. J. Spencer et al., J. Appl. Phys., 73, 4956 (1993). C. Xu et al., Proc. Nat. Acad. Sci., 114, 57 (2017). L. Q. Zhang et al., Nat. Nanotechnol., 15, 94 (2020). A. J. Louli et al., J. Electrochem. Soc., 166, A1291 (2019). K. L. Harrison et al., ACS Appl. Mater. Interfaces, 13, 31668 (2021). S. Lv et al., Nat. Commun., 9, 2152 (2018). J. Steiger et al., J. Power Sources, 261, 112 (2014). B. Hutchinson et al., Mater. Sci. Forum, 467-470, 465 (2004). S. Narayan and L. Anand, J. Electrochem. Soc., 167, 040525 (2020).