Capillary electrophoresis–electrochemiluminescence detection method for the analysis of ibandronate in drug formulations and human urine

A simple, rapid and sensitive CE method coupled with electrochemiluminescence (ECL) detection for direct analysis of ibandronate (IBAN) has been developed. Using a buffer solution of 20 mM sodium phosphate (pH 9.0) and a voltage of 13.5 kV, separation of IBAN in a 30‐cm length capillary was achieved in 3 min. ECL detection was performed with an indium tin oxide working electrode bias at 1.6 V (versus a Pt wire reference) in a 200‐mM sodium phosphate buffer (pH 8.0) containing 3.5 mM Ru(bpy) 3 2+ (where bpy=2,2′‐bipyridyl). Derivatization of IBAN prior to CE‐ECL analysis was not needed. Linear correlation ( r =0.9992, n =7) between ECL intensity and analyte concentration was obtained in the range of 0.25–50 μM IBAN. The LOD of IBAN in water was 0.08 μM. The developed method was applied to the analysis of IBAN in a drug formulation and human urine sample. SPE using magnetic Fe 3 O 4 @Al 2 O 3 nanoparticles as the extraction phase was employed to pretreat the urine sample before CE‐ECL analysis. The linear range was 0.2–12.0 μM IBAN in human urine ( r =0.9974, n =6). The LOD of IBAN in urine was 0.06 μM. Total analysis time including sample preparation was <1 h.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87050/1/2155_ftp.pd

Width-tuned magnetic order oscillation on zigzag edges of honeycomb nanoribbons

Quantum confinement and interference often generate exotic properties in nanostructures. One recent highlight is the experimental indication of a magnetic phase transition in zigzag-edged graphene nanoribbons at the critical ribbon width of about 7 nm [G. Z. Magda et al., Nature \textbf{514}, 608 (2014)]. Here we show theoretically that with further increase in the ribbon width, the magnetic correlation of the two edges can exhibit an intriguing oscillatory behavior between antiferromagnetic and ferromagnetic, driven by acquiring the positive coherence between the two edges to lower the free energy. The oscillation effect is readily tunable in applied magnetic fields. These novel properties suggest new experimental manifestation of the edge magnetic orders in graphene nanoribbons, and enhance the hopes of graphene-like spintronic nanodevices functioning at room temperature.Comment: 22 pages, 9 figure

Learning satisfaction of undergraduates in single-sex-dominated academic fields in Taiwan

AbstractThe present study investigated relationships between undergraduates’ learning satisfaction, academic identity, self-esteem and feeling of depression and loneliness in Taiwan. Data were from a national survey in Taiwan. Participants were 15,706 third-year undergraduates (8719 female, 6987 male). The results showed that, after controlling for undergraduates’ academic performance and attitudes toward university and department, (1) learning satisfaction of females in male-dominant fields was negatively correlated with their feeling of depression, (2) learning satisfaction of males in female-dominant fields was positively correlated with their academic identity and self-esteem, and (3) learning satisfaction of undergraduates in non-dominated fields was positively correlated with their academic identity and self-esteem but also negatively correlated with their feelings of depression

On a retailer’s EOQ in a supply chain with two-level trade credit

Recently, Teng and Goyal [Journal of the Operational Research Society, Vol. 58, pp. 1252-1255, 2007.] extended and modified Huang’s model [Journal of the Operational Research Society, Vol. 54, pp. 1011-1015, 2003.] to develop their model and established the proper theoretical results to obtain the optimal solution. Their inventory model is correct and interesting. However, they give the optimal solutions showing that Theorems 1 and 2 in Teng and Goyal are not complete. The main purpose of this paper is to overcome Teng and Goyal’s shortcomings and to present complete proofs of their Theorems 1 and 2

Applying Cytogenetics in Phylogenetic Studies

Cytogenetics, with its fundamental role in the field of genetic investigation, continues to be an indispensable tool for studying phylogenetics, given that currently molecular evolutionary analyses are more commonly utilized. Chromosomal evolution indicated that genomic evolution occurs at the level of chromosomal segments, namely, the genomic blocks in the size of Mb‐level. The recombination of homologous blocks, through the mechanisms of insertion, translocation, inversion, and breakage, has been proven to be a major mechanism of speciation and subspecies differentiation. Meanwhile, molecular cytogenetics (fluorescence in situ hybridization‐based methodologies) had been already widely applied in studying plant genetics since polyploidy is common in plant evolution and speciation. It is now recognized that comparative cytogenetic studies can be used to explore the plausible phylogenetic relationships of the extant mammalian species by reconstructing the ancestral karyotypes of certain lineages. Therefore, cytogenetics remains a feasible tool in the study of comparative genomics, even in this next generation sequencing (NGS) prevalent era

Backpropagating constraints-based trajectory tracking control of a quadrotor with constrained actuator dynamics and complex unknowns

In this paper, a backpropagating constraints-based trajectory tracking control (BCTTC) scheme is addressed for trajectory tracking of a quadrotor with complex unknowns and cascade constraints arising from constrained actuator dynamics, including saturations and dead zones. The entire quadrotor system including actuator dynamics is decomposed into five cascade subsystems connected by intermediate saturated nonlinearities. By virtue of the cascade structure, backpropagating constraints (BCs) on intermediate signals are derived from constrained actuator dynamics suffering from nonreversible rotations and nonnegative squares of rotors, and decouple subsystems with saturated connections. Combining with sliding-mode errors, BC-based virtual controls are individually designed by addressing underactuation and cascade constraints. In order to remove smoothness requirements on intermediate controls, first-order filters are employed, and thereby contributing to backstepping-like subcontrollers synthesizing in a recursive manner. Moreover, universal adaptive compensators are exclusively devised to dominate intermediate tracking residuals and complex unknowns. Eventually, the closed-loop BCTTC system stability can be ensured by the Lyapunov synthesis, and trajectory tracking errors can be made arbitrarily small. Simulation studies demonstrate the effectiveness and superiority of the proposed BCTTC scheme for a quadrotor with complex constrains and unknowns

Polynomial Fuzzy Observer-Based Feedback Control for Nonlinear Hyperbolic PDEs Systems

This article explores the observer-based feedback control problem for a nonlinear hyperbolic partial differential equations (PDEs) system. Initially, the polynomial fuzzy hyperbolic PDEs (PFHPDEs) model is established through the utilization of the fuzzy identification approach, derived from the nonlinear hyperbolic PDEs model. Various types of state estimation and controller design problems for the polynomial fuzzy PDEs system are discussed concerning the state estimation problem. To investigate the relaxed stability problem, Euler’s homogeneous theorem, Lyapunov–Krasovskii functional with polynomial matrices (LKFPM), and the sum-of-squares (SOSs) approach are adopted. The exponential stabilization condition is formulated in terms of the spatial-derivative-SOSs (SD-SOSs). Additionally, a segmental algorithm is developed to find the feasible solution for the SD-SOS condition. Finally, a hyperbolic PDEs system and several numerical examples are provided to illustrate the validity and effectiveness of the proposed results