bluuebunny/crossref_metadata_2025_split huggingface dataset:
Giant thermopower in 3D-magnetic multilayers. Structural and electron band effects (abstract)
Authors: de Azevedo M. M. P. , Almeida B. G. , Amaral V. S. , Braga M. E. , Sousa J. B. , Freitas P. P. , Krishnan R. 
Published: July 2002

We report measurements of the thermoelectric power (S) and electrical resistivity (ρ) in sputtered multilayers of M(10 Å)/Au25Cu75(t) (with M=Co or Ni) directly grown on Si (100), and in UHV—evaporated Pt 20 Å/Ni(x) multilayers grown on Si(111). The multilayers have thicknesses t=21 Å, 23 Å, and x=19.5 Å, 39 Å, and the data spans the temperature range 10–300 K. All the samples exhibit an anomalous thermopower at high temperatures, with a huge maximum in S and a sharp peak in the temperature derivative dS/dT at a characteristic temperature T*, e.g., ∼190 K for Ni/Pt and ∼260 K for M/Au25Cu75 multilayers. In all cases the thermopower decreases abruptly at T*, from a giant positive value (S≊80 μV K−1 in Ni/Pt and S≊12–50 μV K−1 in M/Au25Cu75) to values close to zero below T*. The electrical resistivity also displays an anomaly over the same temperature range, characterized by a rapid resistivity enhancement Δρ∼1 μΩ cm (within ΔT ∼60 K) when T decreases below T*.
This produces a sharp minimum in the derivative dρ/dT at T*. The shape of the S(T) anomaly is remarkably similar in all cases (mutatis mutandis) for ρ(T), suggesting a general underlying physical mechanism. We found that a suitable buffer (e.g., 100 Å Pt in Ni/Pt, Fe50 Å in Co/Au25Cu75 and 50 Å in Ni/Au25Cu75) suppresses the anomalies, indicating a structural-related underlying effect. In this case, S values are small and negative (as occurs with Ni and Co), exhibiting the usual smooth variation over the whole temperature range. At this stage, it is not clear what is the precise physical mechanism responsible for the observed anomalies. Interfacial atomic mixing in the nonbuffered multilayers may cause individual magnetic atoms or clusters to have entirely nonmagnetic environments (Au, Cu, or Pt in our samples). This situation could give an anomalous transport contribution, through conduction electron scattering at virtual bound states (VBS) localized in the (3-D) magnetic atoms. A sharp peak occurs in the local density of states, N(E), at a characteristic energy EL. A giant thermopower may result when the Fermi level is close to EL (S∝dN/dE; very large).
The VBS model successfully explains large S values observed in bulk noble metals diluted with 3-D magnetic impurities such as Co and Ni. However, the standard treatment does not lead to a sharp cutoff-temperature, below which S(T) gets negligible. Another contribution is the usual s-d electron transition mediated by phonon scattering. This leads to a thermopower proportional to the energy derivative of the splitted ferromagnetic 3D band density of states at EF, which can be very large when sub-band filling is almost complete.
Effects of Zn ion on magnetic properties of Fe3O4 magnetic colloids (abstract)
Authors: Lin C. H. , Kuo P. C. , Pan J. L. , Huang D. R. 
Published: July 2002

The effects of Zn ion on magnetic properties Fe3O4 magnetic colloids were investigated in this study. Fe3O4 magnetic colloids were produced by the chemical coprecipitation method, i.e., mixing an acidic solution containing FeCl2⋅4H2O, FeCl3⋅6H2O, ZnCl2⋅4H2O, with a NaOH alkali solution at 70 °C, and then centrifuging them from the mixed solution. Various reaction times, solution pH values, and Zn ion contents were also used. Fe3O4 magnetic fluid was obtained by adding ammonium oleate into the mixed solution, precipitating the colloids from the solution, neutralizing the colloids by hydrochloric acid, and dispersing the colloids in n-hexane. XRD, EDX, TEM, and VSM were used to determine the structure, chemical compositions, particle sizes, and magnetic properties of the colloids and the magnetic fluid. The spinel colloids was easily form at a higher pH value in solutions where the pH value ranged from 7 to 12. Fe3O4 colloids were completely formed within the first minute of mixing and the particle size of Fe3O4 colloids did not increase with time after the first minute.
The lattice parameter of Fe3O4 colloids increased linearly with the Zn ion content because the diameter of Zn ion is larger than that of Fe ions. The particle size of Fe3O4 colloids was found to be 10 nm by TEM. For an initially fixed Zn content of 8 wt % in solutions, the Zn content in the Fe3O4 colloids ranged from 3.32 wt % at pH=5 to a maximum value of 7.85 wt % at pH=10. Later, it reduced to 7.51 wt % at pH=12 because Zn ion has the lowest solubility at pH=10. At 8 wt % of zinc ion in the solution, the σs of the Fe3O4 colloid increase sharply from 0 at pH=3 to 92 emu/g at pH=8 and then reach a maximum value of 94 at pH=10. The σs value and Hc value of the Fe3O4 colloid were found significantly improved by adding a suitable amount of Zn ions, e.g., ranging from 70 emu/g and 48 Oe at Zn=0 wt % to a maximum 94 emu/g and 50 Oe at Zn=7.14 wt %. Later they reduced to 70 emu/g and 44 Oe at Zn=12.52 wt % when prepared at pH=10. The σs value of the magnetic fluid was found linearly proportional to the colloid content in the magnetic fluid. For a colloid containing 7.51 wt % of Zn ion, the σs value of the magnetic fluid is 9.8 emu/g at 25 wt % of colloid.
Low-lying stationary points and torsional interconversions of cyclic (H2O)4: An ab initio study
Authors: Schütz Martin , Klopper Wim , Lüthi Hans-Peter , Leutwyler Samuel 
Published: July 2002

The global and local minima, stationary points, and torsional rearrangement processes of cyclic homodromic (H2O)4 were studied on its four-dimensional torsional intermolecular potential energy surface. Eight different energetically low-lying torsional stationary point structures were found by ab initio theory, and fully structure-optimized at the second-order Mo/ller–Plesset level, using large basis sets. Second-order energies close to the one-particle basis set limit were obtained at these geometries using the explicitly correlated Mo/ller–Plesset method. The effects of higher-order correlation energy terms were investigated by coupled cluster theory, and terms beyond second order were found to cancel in good approximation. The S4 symmetric global minimum has a square and almost planar O...O...O...O arrangement with free O–H bonds alternating ‘‘up’’ and ‘‘down’’ relative to this plane, with two isometric versions of this structure. Another torsional conformer with two neighboring up O–H bonds followed by two neighboring down O–H bonds is a local minimum, 0.93 kcal/mol above the global minimum. The four versions of this structure are connected to the global minima via two distinct but almost degenerate first-order torsional saddle points, which occur as two sets of eight isometric versions each, both about 1.24 kcal/mol above the global minimum. Yet another set of eight second-order saddle points lies at 1.38 kcal/mol. The structure with three O–H bonds up and one down is not a stationary point, while the structure with all four O–H bonds on the same side of the plane is a first-order saddle point.
The fully planar C4h symmetric structure is a fourth-order stationary point 2.8 kcal/mol above the minimum. The torsional interconversion paths between this multitude of points are complex, and are discussed in three-dimensional spaces of symmetry-adapted torsional coordinates, and also in a network representation. The torsional normal-mode eigenvectors point fairly directly along the torsional interconversion pathways, but the harmonic frequencies are well below the corresponding barriers. Tunneling interconversion between torsional conformers is, hence, less important than for the water trimer.
Theory of hot particle stability
Authors: Berk H. L. , Wong H. V. , Tsang K. T. 
Published: July 2002

The investigation of stabilization of hot particle drift reversed systems to low frequency modes has been extended to arbitrary hot beta βH, for systems that have unfavorable field-line curvature. Steep profile equilibria are considered where the thickness of the pressure drop Δ, is less than plasma radius rp. The analysis describes layer modes which have mΔ/rp &lt;1, where m is the mode number, and radial structure larger than Δ. Stabilization is classified as either being ‘‘robust,’’ where all excitations are positive energy, or ‘‘fragile,’’ where stability criteria exist to magnetohydrodynamic (MHD)-like and drift-compressional instabilities, but positive and negative energy waves are present (with the possibility that negative energy waves are destabilized by dissipative mechanisms). It is shown that in making a continuous transition from the fragile stability regime to the robust stability regime one must go through an unstable region. To bridge the unstable band in a physical manner one must either produce robust stability conditions very rapidly, or use transient stability techniques such as ponderomotive forces or transient minimum-B coils. The positive energy stabilization terms of the layer mode from wall stabilization terms and finite Larmor radius terms are explicitly exhibited.
It is shown the robust stability can even be achieved with only wall stabilization for all possible m values of the layer modes if βH &gt; (2)/(3) . When robust stability conditions are fulfilled, the hot particles will have their bounce frequency less than their grad-B drift frequency. This allows for a low bounce frequency expansion to describe the axial dependence of the magnetic compressional response. Such as expansion provides for another negative energy source in the theory, with the system then being susceptible to the drift compressional instability if dβH/dr &gt;dβw/dr, where βw is the beta of the background plasma. If robust stabilization conditions are not fulfilled, the regions of fragile stability are extremely small if the MHD-like modes, the diamagnetic compressional and drift-compressional modes are to be simultaneously avoided.
The drug situation in Thailand: the role of government and the police
Authors: CHEURPRAKOBKIT SUTHAM 
Published: July 2002

AbstractThailand has long dealt with the drug problem and has used several strategies to control it, including promulgating and amending drug laws, implementing drug suppression and prevention policies, cooperating with international organizations and, more recently, developing treatment facilities. Although Thailand has recently received positive results regarding reducing the opium cultivation area in the Golden Triangle and in arresting some major drug‐trafficking individuals, three important issues still remain: (1) the continuation of using Thailand's advanced transportation system for the movement of illicit drug activities, (2) the rapid increase of amphetamine use among teenagers and (3) the Thai police officers' lack of concern about the drug problem and insufficient knowledge about drug laws. The article concludes that the Thai government must emphasize drug prevention strategies and the interception of illicit transported drugs and motivate its police officers to more fully enforce drug laws. In addition, more research is needed to measure the effectiveness of the drug prevention strategies and treatment programs.
A model for prediction of fume formation rate in gas metal arc welding (GMAW), globular and spray modes, DC electrode positive
Authors: Dennis John H. , Hewitt Peter J. , Redding Christopher A. J. , Workman Andrew D. 
Published: July 2002

Abstract
Prediction of fume formation rate during metal arc welding and the composition of the fume are of interest to occupational hygienists concerned with risk assessment and to manufacturers of welding consumables. A model for GMAW (DC electrode positive) is described based on the welder determined process parameters (current, wire feed rate and wire composition), on the surface area of molten metal in the arc and on the partial vapour pressures of the component metals of the alloy wire. The model is applicable to globular and spray welding transfer modes but not to dip mode. Metal evaporation from a droplet is evaluated for short time increments and total evaporation obtained by summation over the life of the droplet. The contribution of fume derived from the weld pool and spatter (particles of metal ejected from the arc) is discussed, as are limitations of the model. Calculated droplet temperatures are similar to values determined by other workers. A degree of relationship between predicted and measured fume formation rates is demonstrated but the model does not at this stage provide a reliable predictive tool.
Analysis of temporal gene expression profiles: clustering by

simulated annealing and determining the optimal number of clusters
Authors: Lukashin Alexander V. , Fuchs Rainer 
Published: July 2002

Abstract
Motivation: Cluster analysis of genome-wide expression data from DNA microarray hybridization studies has proved to be a useful tool for identifying biologically relevant groupings of genes and samples. In the present paper, we focus on several important issues related to clustering algorithms that have not yet been fully studied.
Results: We describe a simple and robust algorithm for the clustering of temporal gene expression profiles that is based on the simulated annealing procedure. In general, this algorithm guarantees to eventually find the globally optimal distribution of genes over clusters. We introduce an iterative scheme that serves to evaluate quantitatively the optimal number of clusters for each specific data set. The scheme is based on standard approaches used in regular statistical tests. The basic idea is to organize the search of the optimal number of clusters simultaneously with the optimization of the distribution of genes over clusters. The efficiency of the proposed algorithm has been evaluated by means of a reverse engineering experiment, that is, a situation in which the correct distribution of genes over clusters is known a priori. The employment of this statistically rigorous test has shown that our algorithm places greater than 90% genes into correct clusters. Finally, the algorithm has been tested on real gene expression data (expression changes during yeast cell cycle) for which the fundamental patterns of gene expression and the assignment of genes to clusters are well understood from numerous previous studies.
Availability: The source code of the program implementing the algorithm is available upon request from the authors.
Contact: alex_lukashin@biogen.com
* To whom correspondence should be addressed.
Levofloxacin: serum bactericidal activity against methicillin-resistant Staphylococcus aureus isolates
Authors: Muller-Serieys C. , Decré D. , Benoit C. , Bigot C. , Maubert B. , Carbon C. 
Published: July 2002

Abstract
The aim of this study was to assess the serum bactericidal activity (SBA) of levofloxacin compared with that of ofloxacin against methicillin-resistant Staphylococcus aureus (MRSA) isolates. Serum from 10 healthy volunteers (seven females, three males) was collected after a single oral dose of either levofloxacin (500 mg) or ofloxacin (400 mg). Subjects were allocated randomly to treatment after at least a 1 week interval between antibiotic regimens. Three well-defined MRSA strains were tested, each susceptible to levofloxacin and ofloxacin, with different levels of resistance to methicillin (HBD 456, HBD 3 and HBD 2; class 1, 2 and 3 Tomasz heterogeneous resistance, respectively) together with a methicillin-susceptible (MSSA) reference strain ( S. aureus ATCC 25923). SBA was tested in vitro by a microtitration method 15 min before dosing and at 1, 4, 8 and 12 h after drug absorption. Levofloxacin was significantly more bactericidal than ofloxacin against all strains of S. aureus tested (SBA ≥1:2). An SBA was recorded for only a short period with ofloxacin, and thereafter only bacteriostatic activity remained. This study, therefore, confirms the superior activity of levofloxacin over that of ofloxacin against MSSA and MRSA.
Obesity and Response to Advanced Therapies in Rheumatoid Arthritis
Authors: Baker Joshua F. , Reed George , Poudel Dilli Ram , Harrold Leslie R. , Kremer Joel M. 
Published: February 2022

ObjectiveWe performed a study of tumor necrosis factor inhibitors (TNFi) compared to non‐TNFi biologic therapies in rheumatoid arthritis to test whether body mass index (BMI) modified the effect of each therapy.MethodsWe utilized data from CorEvitas. We studied 3 clinical outcomes based on the Clinical Disease Activity Index (CDAI) at 6 months from therapy initiation: 1) achievement of low disease activity (LDA); 2) a change as large as the minimum clinically important difference (MCID); and 3) the absolute change. We categorized BMI and utilized restricted cubic splines to consider nonlinear associations. We used linear and logistic regression to evaluate associations with response, adjusting for confounders. To determine if comparative effectiveness of therapy varied by BMI, we tested for interactions between BMI and class of therapy.ResultsThe sample included 2,891 TNFi and 3,010 non‐TNFi initiators. Among all initiators, those with severe obesity experienced lower odds of achieving LDA or MCID and less improvement in CDAI score, although associations were attenuated with adjustment. Low BMI was associated with reduced response rates in adjusted models including lower odds of LDA (odds ratio 0.32 [95% confidence interval (95% CI) 0.15, 0.71], P = 0.005). Analyses stratified by TNFi and non‐TNFi therapies demonstrated no differences in clinical response rates for TNFi versus non‐TNFi across BMI categories (all P for interaction >0.05). Estimates for non‐TNFi biologics fit within the 95% CI for TNFi.ConclusionThis study observed lower response rates among obese and underweight patients and no evidence of a superior effect of non‐TNFi therapy over TNFi therapy in particular BMI categories.
SDF‐based tracking control for state‐constrained nonholonomic systems with disturbances via relay switching control: Theory and experiment
Authors: Zhang Shengmiao , Gao Yang , Zhang Zhongcai , Cao Dianguo 
Published: February 2022

SummaryThis article investigates the tracking control problem for a kind of chained‐form nonholonomic systems in the presence of unknown time‐varying disturbances and full‐state constraints. First, a finite‐time tracking controller is constructed to drive the action of relay switching, which converts the whole control system into two design stages. In order to handle with the predefined asymmetric state constraints, the original tracking error system is turned into an unconstrained system on the basis of state‐dependent function (SDF) function transformations. In this framework, an adaptive tracking control strategy is proposed by means of backstepping and dynamic surface control. Correspondingly, another tracking control law is also constructed to assure the stability of the tracking error system before the action of switching. The theoretical analysis of stability indicates that the proposed tracking control scheme can guarantee that the output state tracking errors converge to zero and the desired state constraints are not violated. At the same time, all the closed‐loop system signals maintain bounded in entire control process. Finally, the validity of the presented tracking control algorithm is demonstrated by simulation and experiment results.
Phase Transfer of Mo2C Induced by Boron Doping to Boost Nitrogen Reduction Reaction Catalytic Activity
Authors: Fan Binbin , Wang Haozhi , Zhang Hong , Song Yue , Zheng Xuerong , Li Changjiu , Tan Yeqiang , Han Xiaopeng , Deng Yida , Hu Wenbin 
Published: February 2022

AbstractFacilitating the cleavage of a NN bond and suppressing the competition hydrogen evolution reaction is essential, and but still remains a challenge in nitrogen reduction reaction (NRR). Crystal phase tailoring is an effective approach to optimize the energy barrier during the NRR process to improve the catalytic efficiency. Herein, a boron‐doping strategy to induce phase transfer from hexagonal Mo2C to cubic Mo2C for regulating the electronic structure and catalytic properties of electrocatalysts toward NRR is reported. The B doped cubic Mo2C is found to increase the exposure of active sites, regulate the d band center of Mo for enhancing the adsorption and activation of nitrogen, and reduce the energy barrier of NRR pathway, giving rise to a high ammonia yield of 52.1 μg h−1 mg−1 at −0.6 V versus reversible hydrogen electrode under ambient conditions. More importantly, the hydrogen adsorption on the surface of electrocatalyst is significantly inhibited due to the B‐doping, further improving the faradic efficiency to 36.9%, which is 4 times that of hexagonal Mo2C (9%). This work not only sheds light on the atomic‐scale design of efficient NRR electrocatalysts, but also provides a promising avenue for synchronizing the catalytic activity and selectivity for catalytic reactions.
Antibody‐Incorporated Nanomedicines for Cancer Therapy
Authors: Wu Shun‐Yu , Wu Fu‐Gen , Chen Xiaoyuan 
Published: February 2022

AbstractAntibody‐based cancer therapy, one of the most significant therapeutic strategies, has achieved considerable success and progress over the past decades. Nevertheless, obstacles including limited tumor penetration, short circulation half‐lives, undesired immunogenicity, and off‐target side effects remain to be overcome for the antibody‐based cancer treatment. Owing to the rapid development of nanotechnology, antibody‐containing nanomedicines that have been extensively explored to overcome these obstacles have already demonstrated enhanced anticancer efficacy and clinical translation potential. This review intends to offer an overview of the advancements of antibody‐incorporated nanoparticulate systems in cancer treatment, together with the nontrivial challenges faced by these next‐generation nanomedicines. Diverse strategies of antibody immobilization, formats of antibodies, types of cancer‐associated antigens, and anticancer mechanisms of antibody‐containing nanomedicines are provided and discussed in this review, with an emphasis on the latest applications. The current limitations and future research directions on antibody‐containing nanomedicines are also discussed from different perspectives to provide new insights into the construction of anticancer nanomedicines.
Detection of Neurofilament Light Chain with Label‐Free Electrolyte‐Gated Organic Field‐Effect Transistors
Authors: Solodka Kateryna , Berto Marcello , Ferraro Diana , Menozzi Claudia , Borsari Marco , Bortolotti Carlo A. , Biscarini Fabio , Pinti Marcello 
Published: February 2022

AbstractNeurofilaments are structural scaffolding proteins of the neuronal cytoskeleton. Upon axonal injury, the neurofilament light chain (NF‐L) is released into the interstitial fluid and eventually reaches the cerebrospinal fluid and blood. Therefore, NF‐L is emerging as a biomarker of neurological disorders, including neurodegenerative dementia, Parkinson's disease, and multiple sclerosis. It is challenging to quantify NF‐L in bodily fluids due to its low levels. This work reports the detection of NF‐L in aqueous solutions with an organic electronic device. The biosensor is based on the electrolyte‐gated organic field‐effect transistor (EGOFET) architecture and can quantify NF‐L down to sub‐pM levels; thanks to modification of the device gate with anti‐NF‐L antibodies imparted with potentially controlled orientation. The response is fitted to the Guggenheim–Anderson–De Boer adsorption model to describe NF‐L adsorption at the gate/electrolyte interface, to consider the formation of a strongly adsorbed protein layer bound to the antibody and the formation of weakly bound NF‐L multilayers, an interpretation which is also backed up by morphological characterization via atomic force microscopy. The label‐free, selective, and rapid response makes this EGOFET biosensor a promising tool for the diagnosis and monitoring of neuronal damages through the detection of NF‐L in physio‐pathological ranges.