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Katwal BM, Gautam N, Shrestha S, Adhikari R, Baral H, Jha SK, Jha G. Association of Different Biochemical and Hemodynamic Characteristic with Type 2 Diabetes Mellitus and Hypertension in Nephrolithiasis Patients. Kathmandu Univ Med J (KUMJ) 2023; 21:58-63. [PMID: 37800427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Background Although Nephrolithiasis is a common condition caused by a wide variety of metabolic or environmental disturbances, its being one of the major factor of morbidity. Incidence of kidney stone disease (KSD) is highly affected by metabolic disorders and change in blood pressure and glucose. Objective To find out association of different biochemical and hemodynamic parameters with various glycemic status and hypertension in kidney stone disease. Method A cross sectional study was conducted in patients diagnosed as nephrolithiasis by using re¬nal ultrasonography and underwent nephrectomy between January 2019 to January 2021 in Shahid Dharmabhakta National Transplant Centre (SDNTC). A total of 100 subjects with 60 male and 40 females were enrolled. Glycemic status was categorized based on criteria of American Diabetes Association (ADA) and hypertension was defined as BP ≥ 140/90 mm Hg in right arm supine position. All biochemical and hemodynamic profile was carried out following standard protocol. Result Out of 100 patients enrolled, pre-diabetes accounted for 31% followed by diabetes (4%). However, hypertension comprised of 66% in total subjects. Serum urea, cholesterol and triglyceride level were found to be increased by 84.6%, 67.7% and 64.7% respectively in diabetes followed by increase of 3.9%, 19.5% and 3.1% respectively in prediabetes when compared to normal glycemic condition in nephrolithiasis subjects. Serum fasting blood glucose, creatinine and uric acid level was observed significantly higher (p=0.003, p=0.004, p < 0.001 respectively) in hypertensive patients. Duration of hospital stay was also seen positively correlated with hypertension. Conclusion Not only diabetes, prediabetes also manifests the increased risk of kidney stone disease along with hypertension. There is significant impairment in renal function and lipid profile based on diabetes mellitus and hypertension. Early identifying these systemic diseases, different biochemical and hemodynamic parameters and proper treatment accordingly may minimize risk and prevent serious complication in these patients.
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Kriseldi R, Silva M, Lee J, Adhikari R, Williams C, Corzo A. Understanding the interactive effects of dietary leucine with isoleucine and valine in the modern commercial broiler. Poult Sci 2022; 101:102140. [PMID: 36191517 PMCID: PMC9529509 DOI: 10.1016/j.psj.2022.102140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 08/15/2022] [Accepted: 08/16/2022] [Indexed: 12/04/2022] Open
Abstract
A study was conducted to understand the relationship among dietary branched-chain amino acids (BCAA) on the performance of Ross 344 × 708 male broilers. A total of 2,592 d-old male chicks were randomly placed into 144-floor pens according to a 23 full factorial central composite design (CCD) with 20 treatments (14 treatments and 6 center points). Each treatment consisted of varying digestible Ile:Lys (52 to 75), Val:Lys (64 to 87), and Leu:Lys (110 to 185) ratios. Birds and feed were weighed at 20 and 34 d of age to determine body weight gain (BWG), feed intake, and feed conversion ratio (FCR). At 35 d of age, feather amino acid composition and carcass characteristics were evaluated. Data were analyzed as CCD using the surface response option of JMP v. 15. Body weight gain (1,332 g; P < 0.001; R2 = 0.93) and FCR (1.54; P = 0.002; R2 = 0.88) were optimized at the lowest Leu:Lys ratio (110) with moderate Val:Lys (78 to 79) and Ile:Lys (65 to 66) ratios. Poorer BWG and FCR were observed as Leu:Lys ratio increased while increasing Val:Lys and Ile:Lys ratios alleviated the poor performance. Carcass (71.5%; P = 0.031; R2 = 0.76) and breast yield (26.7%; P < 0.001; R2 = 0.96) were maximized at the highest Leu:Lys ratio. This effect was complemented by increasing Ile:Lys ratio beyond 68. Lower Ile:Lys and Val:Lys ratios were required to maximize carcass and breast yield at the lowest Leu:Lys ratio. However, this strategy yielded less meat than providing a high Leu:Lys ratio diet. Dietary BCAA had little effect on altering the composition of feather protein and amino acid (P > 0.10). These results suggest that optimum BCAA ratios to Lys may vary depending on response criteria and demonstrate the importance of maintaining proper Val and Ile ratios centered on dietary Leu. Live performance can be optimized in diets with low Leu:Lys ratios; however, meat yield can be enhanced by increasing dietary Leu:Lys along with Ile:Lys ratios.
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Brown A, Lee J, Adhikari R, Haydon K, Wamsley K. Determining the optimum digestible isoleucine to lysine ratio for Ross 708 x Ross YP male broilers from 0 to 18 d of age. J APPL POULTRY RES 2022. [DOI: 10.1016/j.japr.2021.100217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Rabaan AA, Mutair AA, Alawi ZA, Alhumaid S, Mohaini MA, Aldali J, Tirupathi R, Sule AA, Koritala T, Adhikari R, Bilal M, Dhawan M, Mohapatra RK, Tiwari R, Sami SA, Mitra S, Pandey MK, Harapan H, Emran TB, Dhama K. Comparative pathology, molecular pathogenicity, immunological features, and genetic characterization of three highly pathogenic human coronaviruses (MERS-CoV, SARS-CoV, and SARS-CoV-2). EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2021; 25:7162-7184. [PMID: 34859882 DOI: 10.26355/eurrev_202111_27270] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The last two decades have witnessed the emergence of three deadly coronaviruses (CoVs) in humans: severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are still no reliable and efficient therapeutics to manage the devastating consequences of these CoVs. Of these, SARS-CoV-2, the cause of the currently ongoing coronavirus disease 2019 (COVID-19) pandemic, has posed great global health concerns. The COVID-19 pandemic has resulted in an unprecedented crisis with devastating socio-economic and health impacts worldwide. This highlights the fact that CoVs continue to evolve and have the genetic flexibility to become highly pathogenic in humans and other mammals. SARS-CoV-2 carries a high genetic homology to the previously identified CoV (SARS-CoV), and the immunological and pathogenic characteristics of SARS-CoV-2, SARS-CoV, and MERS contain key similarities and differences that can guide therapy and management. This review presents salient and updated information on comparative pathology, molecular pathogenicity, immunological features, and genetic characterization of SARS-CoV, MERS-CoV, and SARS-CoV-2; this can help in the design of more effective vaccines and therapeutics for countering these pathogenic CoVs.
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Brown A, Lee J, Adhikari R, Haydon K, Wamsley K. Determining the optimal digestible isoleucine to lysine ratio of Ross 708 × Ross YP male broilers from 28 to 42 days of age. J APPL POULTRY RES 2021. [DOI: 10.1016/j.japr.2021.100205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Li YI, Turk G, Rohrbach PB, Pietzonka P, Kappler J, Singh R, Dolezal J, Ekeh T, Kikuchi L, Peterson JD, Bolitho A, Kobayashi H, Cates ME, Adhikari R, Jack RL. Efficient Bayesian inference of fully stochastic epidemiological models with applications to COVID-19. ROYAL SOCIETY OPEN SCIENCE 2021; 8:211065. [PMID: 34430050 PMCID: PMC8355677 DOI: 10.1098/rsos.211065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
Epidemiological forecasts are beset by uncertainties about the underlying epidemiological processes, and the surveillance process through which data are acquired. We present a Bayesian inference methodology that quantifies these uncertainties, for epidemics that are modelled by (possibly) non-stationary, continuous-time, Markov population processes. The efficiency of the method derives from a functional central limit theorem approximation of the likelihood, valid for large populations. We demonstrate the methodology by analysing the early stages of the COVID-19 pandemic in the UK, based on age-structured data for the number of deaths. This includes maximum a posteriori estimates, Markov chain Monte Carlo sampling of the posterior, computation of the model evidence, and the determination of parameter sensitivities via the Fisher information matrix. Our methodology is implemented in PyRoss, an open-source platform for analysis of epidemiological compartment models.
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Llamas-Moya S, Higgins N, Adhikari R, Lawlor P, Lacey S. Effect of multicarbohydrase enzymes containing α-galactosidase on the growth and apparent metabolizable energy digestibility of broiler chickens: a meta-analysis. Anim Feed Sci Technol 2021. [DOI: 10.1016/j.anifeedsci.2021.114949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Adhikari R, Doesinger K, Lindner P, Faina B, Bonanni A. Low temperature and high magnetic field performance of a commercial piezo-actuator probed via laser interferometry. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:035002. [PMID: 33820055 DOI: 10.1063/5.0034569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/20/2021] [Indexed: 06/12/2023]
Abstract
The advances in the fields of scanning probe microscopy, scanning tunneling spectroscopy, point contact spectroscopy, and point contact Andreev reflection spectroscopy to study the properties of conventional and quantum materials under cryogenic conditions have prompted the development of nanopositioners and nanoscanners with enhanced spatial resolution. Piezoelectric-actuator stacks as nanopositioners with working strokes of 10 μm and positioning resolution ∼(1-10) nm are desirable for both basic research and industrial applications. However, information on the performance of most commercial piezoelectric actuators in cryogenic environment and in the presence of magnetic fields in excess of 5 T is generally not available. In particular, the magnitude, the rate, and the associated hysteresis of the piezo-displacement at cryogenic temperatures are the most relevant parameters that determine whether a particular piezoelectric actuator can be used as a nanopositioner. Here, the design and realization of an experimental setup based on interferometric techniques to characterize a commercial piezoelectric actuator over a temperature range of 2 K ≤ T ≤ 260 K and magnetic fields up to 6 T are presented. The studied piezoelectric actuator has a maximum displacement of 30 μm at room temperature for a maximum driving voltage of 75 V, which reduces to 1.2 μm with an absolute hysteresis of 9.1±3.3nm at T = 2 K. The magnetic field is shown to have no substantial effect on the piezo-properties of the studied piezoelectric-actuator stack.
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Kumar A, Adhikari R, Dua A. Transients generate memory and break hyperbolicity in stochastic enzymatic networks. J Chem Phys 2021; 154:035101. [DOI: 10.1063/5.0031368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Caciagli A, Singh R, Joshi D, Adhikari R, Eiser E. Controlled Optofluidic Crystallization of Colloids Tethered at Interfaces. PHYSICAL REVIEW LETTERS 2020; 125:068001. [PMID: 32845661 DOI: 10.1103/physrevlett.125.068001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
We report experiments that show rapid crystallization of colloids tethered to an oil-water interface in response to laser illumination. This light-induced transition is due to a combination of long-ranged thermophoretic pumping and local optical binding. We show that the flow-induced force on the colloids can be described as the gradient of a potential. The nonequilibrium steady state due to local heating thus admits an effective equilibrium description. The optofluidic manipulation explored in this work opens novel ways to manipulate and assemble colloidal particles.
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Adhikari P, Kiess A, Adhikari R, Jha R. An approach to alternative strategies to control avian coccidiosis and necrotic enteritis. J APPL POULTRY RES 2020. [DOI: 10.1016/j.japr.2019.11.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Shakya Shrestha S, Adhikari R, Tamrakar S, Shrestha R, Shrestha A. Adherence to Iron, Folic Acid and Calcium Supplement and Factors Affecting it among the Antenatal Care Attending Women in a Tertiary Care Hospital: A Cross Sectional Study. Kathmandu Univ Med J (KUMJ) 2020; 18:186-192. [PMID: 33594028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Background Pregnancy or gestation is the time during which a single or more children grows and develops inside a woman. Antenatal care improves the pregnancy outcomes under which a group of medication i.e. iron, folic acid and calcium are supplemented. Despite the effectiveness of such supplements, poor clinical outcomes are often encountered because of poor-adherence to the regimen. Objective To determine the adherence pattern and factors affecting adherence in antenatal care patients under iron, folic acid, and calcium therapy. Method A cross-sectional study was conducted in Dhulikhel Hospital, Kathmandu University Hospital. Pregnant women attending antenatal care under iron, folic acid, and calcium therapy fulfilling the inclusion criteria were enrolled in this study. After obtaining the informed consent from the patients, structured questionnaire was used to interview the patients. Statistical analysis was performed by using SPSS 23.0. P-value < 0.05 was considered as statistically significant. Result Among 191 patients enrolled in this study majority (39.3%) of them belonged to age group 26-30 years. More than half (61.3%) of the patients were illiterate. Of the total 191, 64.40% were non-adherent to the medication. Forgetfulness was the main reason for missing the dose in majority (52.06%) of the non-adherent subjects while adverse effects (55.40%) was the most prominent cause for discontinuing the medication among non-adherent participants. Significant association was found between patients' adherence and busy work schedule, visiting doctor for follow up. Conclusion More than half of the patients had not adhered to the medication under antenatal care. Forgetfulness was the most common factor for missing the dose in nonadherent patients. Illiteracy was associated with poor adherence. Patient-provider relationship, Socio-economic factors were determined as major barrier to medication adherence.
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Bolitho A, Singh R, Adhikari R. Periodic Orbits of Active Particles Induced by Hydrodynamic Monopoles. PHYSICAL REVIEW LETTERS 2020; 124:088003. [PMID: 32167321 DOI: 10.1103/physrevlett.124.088003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
Terrestrial experiments on active particles, such as Volvox, involve gravitational forces, torques and accompanying monopolar fluid flows. Taking these into account, we analyze the dynamics of a pair of self-propelling, self-spinning active particles between widely separated parallel planes. Neglecting flow reflected by the planes, the dynamics of orientation and horizontal separation is symplectic, with a Hamiltonian exactly determining limit cycle oscillations. Near the bottom plane, gravitational torque damps and reflected flow excites this oscillator, sustaining a second limit cycle that can be perturbatively related to the first. Our work provides a theory for dancing Volvox and highlights the importance of monopolar flow in active matter.
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Adhikari R, White D, House JD, Kim WK. Effects of additional dosage of vitamin D 3, vitamin D 2, and 25-hydroxyvitamin D 3 on calcium and phosphorus utilization, egg quality and bone mineralization in laying hens. Poult Sci 2019; 99:364-373. [PMID: 32416821 PMCID: PMC7587905 DOI: 10.3382/ps/pez502] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 09/24/2019] [Indexed: 12/26/2022] Open
Abstract
Vitamin D is essential for the metabolism of calcium (Ca) and phosphorus (P) in birds. The objective of the study was to evaluate the effect of different isoforms of dietary vitamin D on Ca and P utilization, egg quality, and bone mineralization of laying hens. A total of 42 Lohmann white laying hens at 57 wk of age were randomly assigned to 7 dietary treatments for 6 wk. Dietary treatments were: 3,000 IU/kg Vit D3 as control, and control with additional 3,000 IU/kg 25-hydroxyvitamin D3 (T1), 9,000 IU/kg 25-hydroxyvitamin D3 (T2), 3,000 IU/kg vitamin D3 (T3), 9,000 IU/kg vitamin D3 (T4), 3,000 IU/kg of vitamin D2 (T5), or 9,000 IU/kg of vitamin D2 (T6). Egg production and egg quality were measured weekly. Fecal samples were collected at weeks 2 and 6 to measure Ca and P utilization. After 6 wk, the left tibia and femurs were collected to measure bone mineral density (BMD) and bone mineral content (BMC). A 1-way ANOVA with Tukey HSD means separation test was used for statistical analysis. There were no significant differences in egg production, egg quality, BMD, or BMC of tibia and femurs among the treatments (P > 0.05). T6 significantly reduced feed intake (P < 0.05). The apparent total tract digestibility (ATTD) of Ca was higher (P < 0.012) in treatments supplemented with additional vitamin D, irrespective of forms. The ATTD of P was higher (P < 0.0001) in T5 compared to the other treatments at both time points. The utilization of Ca and P by laying hens can be improved through the addition of different isoforms of vitamin D in diets. However, additional vitamin D supplementation to laying hens, regardless of forms, had no effect on either bone mineralization or measures of egg quality.
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Singh R, Adhikari R, Cates ME. Competing chemical and hydrodynamic interactions in autophoretic colloidal suspensions. J Chem Phys 2019; 151:044901. [DOI: 10.1063/1.5090179] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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Jasek A, Latham RE, Mañón A, Llamas-Moya S, Adhikari R, Poureslami R, Lee JT. Impact of a multicarbohydrase containing α-galactosidase and xylanase on ileal digestible energy, crude protein digestibility, and ileal amino acid digestibility in broiler chickens. Poult Sci 2018; 97:3149-3155. [PMID: 29897592 DOI: 10.3382/ps/pey193] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 04/25/2018] [Indexed: 11/20/2022] Open
Abstract
Exogenous enzymatic supplementation of poultry feeds, including α-galactosidase and xylanase, has been shown to increase metabolically available energy, although little information has been published on the impact on amino acid digestibility. An experiment was conducted to investigate a multicarbohydrase containing α-galactosidase and xylanase on amino acid digestibility, ileal digestible energy (IDE), and CP in male broiler chicks. The experiment was a 2 × 2 (diet × enzyme) factorial arrangement with 15 replicates of 8 male broilers per replicate raised for 21 d in a battery setting. The 2 dietary treatments included a positive control (PC) and a negative control (NC) diet formulated to contain 2.5% less calculated AME and digestible amino acids. Each of these diets was fed with and without enzyme. Broilers were fed a starter diet from 0-14 d (crumble) and a grower from 14-21 d (pellet). Birds were sampled on day 21 to determine ileal amino acid digestibility, IDE, and CP digestibility. Titanium dioxide (TiO2) was used as an indigestible marker for the determination of digestibility coefficients. Total ileal amino acid digestibility was increased (P = 0.008) by 3.80% with the inclusion of enzyme. Methionine and lysine digestibility was improved (P < 0.05) with the inclusion of enzyme by 3.37% and 2.61%, respectively. Enzyme inclusion increased (P = 0.001) cysteine digestibility by 9.3%. Diet-influenced ileal amino acid digestibility with tryptophan, threonine, isoleucine, and valine digestibility being increased (P < 0.05) in the PC when compared to the NC. IDE was decreased (P = 0.037) in broilers fed the NC diet by 100 kcal/kg feed when compared to broilers fed the PC diet. Enzyme inclusion increased (P = 0.047) IDE value by 90 kcal/kg. Crude protein digestibility was not influenced by diet; however, similar improvements in CP digestibility with enzyme inclusion were observed as with energy. These data support the benefits of a multicarbohydrase containing α-galactosidase and xylanase inclusion to improve nutrient and ileal amino acid digestibility across multiple dietary nutrient profiles.
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Singh R, Ghosh D, Adhikari R. Fast Bayesian inference of the multivariate Ornstein-Uhlenbeck process. Phys Rev E 2018; 98:012136. [PMID: 30110802 DOI: 10.1103/physreve.98.012136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Indexed: 06/08/2023]
Abstract
The multivariate Ornstein-Uhlenbeck process is used in many branches of science and engineering to describe the regression of a system to its stationary mean. Here we present an O(N) Bayesian method to estimate the drift and diffusion matrices of the process from N discrete observations of a sample path. We use exact likelihoods, expressed in terms of four sufficient statistic matrices, to derive explicit maximum a posteriori parameter estimates and their standard errors. We apply the method to the Brownian harmonic oscillator, a bivariate Ornstein-Uhlenbeck process, to jointly estimate its mass, damping, and stiffness and to provide Bayesian estimates of the correlation functions and power spectral densities. We present a Bayesian model comparison procedure, embodying Ockham's razor, to guide a data-driven choice between the Kramers and Smoluchowski limits of the oscillator. These provide novel methods of analyzing the inertial motion of colloidal particles in optical traps.
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Mallick A, Laskar A, Adhikari R, Roy S. Redox Reaction Triggered Nanomotors Based on Soft-Oxometalates With High and Sustained Motility. Front Chem 2018; 6:152. [PMID: 29780800 PMCID: PMC5946003 DOI: 10.3389/fchem.2018.00152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/17/2018] [Indexed: 11/13/2022] Open
Abstract
The recent interest in self-propulsion raises an immediate challenge in facile and single-step synthesis of active particles. Here, we address this challenge and synthesize soft oxometalate nanomotors that translate ballistically in water using the energy released in a redox reaction of hydrazine fuel with the soft-oxometalates. Our motors reach a maximum speed of 370 body lengths per second and remain motile over a period of approximately 3 days. We report measurements of the speed of a single motor as a function of the concentration of hydrazine. It is also possible to induce a transition from single-particle translation to collective motility with biomimetic bands simply by tuning the loading of the fuel. We rationalize the results from a physicochemical hydrodynamic theory. Our nanomotors may also be used for transport of catalytic materials in harsh chemical environments that would otherwise passivate the active catalyst.
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Paudel P, Pandey A, Shrestha R, Neupane A, Lamichhane P, Adhikari R, Gyawali R, Kafle B. Optical properties of natural dyes: prospect of application in dye sensitized solar cells (DSSCs) and organic light emitting diodes (OLEDs). FOOD RESEARCH 2018. [DOI: 10.26656/fr.2017.2(5).096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Del Bianco L, Spizzo F, Li T, Adhikari R, Bonanni A. Influence of Mn co-doping on the magnetic properties of planar arrays of GaxFe4−xN nanocrystals in a GaN matrix. Phys Chem Chem Phys 2018; 20:25411-25420. [DOI: 10.1039/c8cp04475a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mn co-doping affects the formation of iron nitride nanocrystals in a GaN matrix, determining the system's structural and magnetic properties.
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Paul S, Laskar A, Singh R, Roy B, Adhikari R, Banerjee A. Direct verification of the fluctuation-dissipation relation in viscously coupled oscillators. Phys Rev E 2017; 96:050102. [PMID: 29347721 DOI: 10.1103/physreve.96.050102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Indexed: 06/07/2023]
Abstract
The fluctuation-dissipation relation, a central result in nonequilibrium statistical physics, relates equilibrium fluctuations in a system to its linear response to external forces. Here we provide a direct experimental verification of this relation for viscously coupled oscillators, as realized by a pair of optically trapped colloidal particles. A theoretical analysis, in which interactions mediated by slow viscous flow are represented by nonlocal friction tensors, matches experimental results and reveals a frequency maximum in the amplitude of the mutual response which is a sensitive function of the trap stiffnesses and the friction tensors. This allows for its location and width to be tuned and suggests the utility of the trap setup for accurate two-point microrheology.
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Kumar A, Adhikari R, Dua A. Kumar, Adhikari, and Dua Reply. PHYSICAL REVIEW LETTERS 2017; 119:099802. [PMID: 28949555 DOI: 10.1103/physrevlett.119.099802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Indexed: 06/07/2023]
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Abstract
Enhanced colloidal transport beyond the limit imposed by diffusion is usually achieved through external fields. Here, we demonstrate the ballistic transport of a colloidal sphere using internal sources of energy provided by an attached active filament. The latter is modeled as a chain of chemo-mechanically active beads connected by potentials that enforce semi-flexibility and self-avoidance. The fluid flow produced by the active beads and the forces they mediate are explicitly taken into account in the overdamped equations of motion describing the colloid-filament assembly. The speed and efficiency of transport depend on the dynamical conformational states of the filament. We characterize these states using filament writhe as an order parameter and identify ones yielding maxima in speed and efficiency of transport. The transport mechanism reported here has a remarkable resemblance to the flagellar propulsion of microorganisms which suggests its utility in biomimetic systems.
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Bera S, Paul S, Singh R, Ghosh D, Kundu A, Banerjee A, Adhikari R. Fast Bayesian inference of optical trap stiffness and particle diffusion. Sci Rep 2017; 7:41638. [PMID: 28139705 PMCID: PMC5282562 DOI: 10.1038/srep41638] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/19/2016] [Indexed: 11/09/2022] Open
Abstract
Bayesian inference provides a principled way of estimating the parameters of a stochastic process that is observed discretely in time. The overdamped Brownian motion of a particle confined in an optical trap is generally modelled by the Ornstein-Uhlenbeck process and can be observed directly in experiment. Here we present Bayesian methods for inferring the parameters of this process, the trap stiffness and the particle diffusion coefficient, that use exact likelihoods and sufficient statistics to arrive at simple expressions for the maximum a posteriori estimates. This obviates the need for Monte Carlo sampling and yields methods that are both fast and accurate. We apply these to experimental data and demonstrate their advantage over commonly used non-Bayesian fitting methods.
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Pokhrel S, Adhikari R, Yadav P. Fabrication and Characterization of Biodegradable Poly(vinyl alcohol)/Chitosan Blends. ACTA ACUST UNITED AC 2017. [DOI: 10.14233/ajchem.2017.20612] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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