bluuebunny/crossref_metadata_2025 huggingface dataset:
Switch from Palladium‐Catalyzed Cycloisomerization/Dimerization of Terminal Allenyl Ketones to Preferential Formation of Monomers by a 5‐Palladatricyclo[4.1.0.02,4]heptane Catalyst: Synthesis of Furans from Substrates Incompatible with the Commonly Used Silver Catalysts
Authors: Hashmi A. Stephen K. , Sehwarz Lothar
Published: July 2007

By making the choice of either PDCl2(MeCN)2 or PTH rac‐4 as catalyst, the allenyl ketones 1 could be preferentially cycloisomerized/dimerized to either 2,4‐disubstituted furans 3 or preferentially cycloisomerized to the monosubstituted furans 2. Since the PTH catalyst tolerates functional groups like terminal alkynes, α‐halogen ketones, and alkyl halides that inhibit the silver catalysis, the latter method is an important extension of Marshall's Ag1‐catalyzed isomerization of 1 to 2. Some of these latter reactions also showed exciting chemoselectivities, e.g. with allenyl ketones, such as 1c and 1d, which also also possess a 1,6‐enyne substructure, no enynecyclization was observed. This is also the first reported example of catalysis by a PTH.
2,4‐Diphosphoranediyl‐1,3‐diphosphetanes
Authors: Schrödel Hans‐Peter , Schmidpeter Alfred
Published: July 2007

The 1,3‐dichloro‐ and 1,3‐dibromo‐substituted title compounds 5b, c result from the condensation of triphenylphosphonium‐bis(trimethylsily1)methylide 1 with PC13 and PBr3. The chloro derivative 5b undergoes a variety of single and double substitution reactions, of which some have merely been tested and others have been made preparative use of. The substitution of one chloride by an ylidyl, amino, phosphino, or metal carbonyl group is accompanied by the spontaneous dissociation of the other P‐CI bond to yield the, 1,3‐diphosphetenium chlorides 14/15, 19, 31 and 36, respectively. In other cases (9, 27, 32) dissociation can be achieved by means of a Lewis acid. Protonation of 5b occurs at the carbon ring members; methylation and formation of transition metal complexes occurs at a phosphorus ring member. PCl3 degrades the four‐membered ring of5b or enlarges the ring to yield 3,5‐diphosphoranediyl‐l,2,4‐triphospholane derivatives 39, 40, 42.
Palladacycles as Reactive Intermediates
Authors: Dyker Gerald
Published: July 2007

Palladacycles are discussed as the key intermediates of some important preparative ring forming reactions; their reactivity depends strongly on the ring size. The existence of 5‐membered palladacycles, and even 4‐membered palladacycles, is now firmly established, whereas the knowledge of 6‐membered and larger palladacycles is based mainly on mechanistic considerations. The role of 5‐membered palladacycles as catalysts is described briefly.
Reactions of Complex Ligands, LXXVII. Axial‐Chiral Metal Carbenes: Synthesis and Structure of 1,1‐Binaphthyl‐Derived Carbonyl‐Carbene Complexes of Chromium
Authors: Heinz Dötz Karl , Tomuschat Philipp , Nieger Martin
Published: July 2007

Axial‐chiral mono‐ and biscarbene complexes of chromium containing the 1,1‐binaphthyl skeleton have been obtained in both racemic and enantiopure forms in a one‐pot reaction starting from lithiated 2,2‐dimethoxy‐1,1‐binaphthyl (1) and hexacarbonyl chromium via the Fischer route. An X‐ray structure analysis of the biscarbene complex 2 reveals that the biscarbene functionalization significantly increases the dihedral angle defined by the biaryl planes. The enantiopure complexes have been characterized by CD spectroscopy.
Formation of the Cationic [(2‐Aminoethenyl)carbine]iron Complexes by Treatment of (2‐Methoxyethenyl)carbene Complexes with Primary Amines:Synthesis and Characterisation
Authors: Kühn Jürg , Schollmeyer Dieter , Rü‐Braun Karola
Published: July 2007

Cationic (2‐methoxyethenyl)methoxycarbene iron complexes 2, [Cp(CO)2Fe(C(OMe)CHCR(OMe))+][PF6−], are obtained by the addition of methanol to the corresponding (alkynyl)‐methoxycarbene complexes 1, [Cp(CO)2Fe(C(OMe)CCR)+][PF6−]. Primary amines, H2NR', react with these 1,3‐dimethoxy‐substituted (alkenyl)carbene complexes, 2, through an addition/elimination process to yield cationic (2‐aminoethenyl)methoxycarbene iron complexes, 3, [Cp(CO)2Fe(C(OMe)CHCR(NHR'))+][PF6−] in an isolated yield of 71–90%. The complexes 3a–c were characterized by X‐ray structural analyses. Thus, previously isolated products, from the reaction, of the (alkynyl)methoxycarbene complexes 1a and 1c, with aniline at room temperature, are assigned to the structures 3c and 3e. The spectroscopic and structural data obtained are discussed.
Metal Complexes of Biologically Important Ligands, XCIV. Hexanuclear Isocyanide and Carbene Metal Complexes from Neomycin B
Authors: Krawielitzki Stefan , Beck Wolfgang
Published: July 2007

From the amino glycoside neomycin B, the acetate‐protected hexaisocyanide 4 has been prepared. 4 forms the hexanuclear complexes [(4)(AuCl)6] (5), {(4)[Cr(CO)5]6}, {(4)[MCl2(η5‐C5Me5)]6} (M = Rh, Ir), {(4)[RuCl2(p‐cymene)]6}, {(4)‐[MCl2(PR3)]6} (MPd, Pt), and 4{(4)[PdCl(C6H4CH2NMe2)]6). The hexaisocyanohexagold(I) complex 5 reacts with H2NtBu and PhNH2 to give the corresponding carbene complexes. The compounds have been characterized by IR, 13C‐ and 31P‐NMR spectroscopy, and (partially) by FAB‐MS data.
A Novel Approach to the Synthesis of Endohedral Fullerenes as Demonstrated by Endohedral Barium Fullerenes
Authors: Möschel Christian , Jansen Martin
Published: July 2007

A new route to endohedral fullerenes involving the evaporation of carbon and a metal at different positions, i.e. at different temperatures, in a radio‐frequency furnace is described. For the first time, endohedral barium fullerenes within the composition range Ba@C74 to Ba@C136 have been produced in high yields as compared to hollow fullerenes, and have been extracted with CS2. Ba@C60, and Ba@C70, are only soluble in CS2 following sublimation. Furthermore, the first nonlanthanoid dimetallo fullerenes ranging in composition from Ba2@C88 to Ba2@C116 have been obtained. All endohedral barium fullerenes were characterized by mass spectrometry. Properties such as sublimation behaviour, solubility, and sensitivity to air have been studied.
A Novel Stoichiometry for Chlorogold(I) Complexes: Structure of L4Au3Cl3(L =pyrrolidine)
Authors: Jones Peter G. , Ahrens Birte
Published: July 2007

The reaction between (tht)AuCl (tht = tetrahydrothiophene) and neat pyrrolidine (L) leads to the compound L4Au3Cl3. An X‐ray structure determination reveals the presence of molecules LAuCl and ions L2Au+ and Cl−, in the ratio 2:1:1. The packing is characterised by Au.Au contacts and N‐H‐Cl‐hydrogen bonds.
Process Parametric Study for Ethene Carboxylic Acid Removal onto Powder Activated Carbon using Box‐Behnken Design
Authors: Kumar A. , Prasad B. , Mishra I. M.
Published: July 2007

Ethene carboxylic acid removal from wastewater using powder activated carbon (PAC) requires a proper process parametric study to determine its optimal performance characteristics. Response Surface Methodology (RSM) is one of the advanced statistical analysis techniques for parametric studies involving a minimum number of trials. The Box‐Behnken surface statistical design of experiments was carried out with three factors, i.e., dose, w, temperature, T, and time of contact, t, between the ethene carboxylic acid and the adsorbent, while maintaining the ethene carboxylic acid concentration, C0 = 100 mg/L, as a fixed input parameter. The performance of the Box‐Behnken design was analyzed and optimized using Design‐Expert software for ethene carboxylic acid removal onto adsorbent using a batch system. The higher values of the correlation coefficients, lack‐of‐fit greater than 4 and p values < 0.05 are in good agreement with the optimum combination of process parameters, which proves the fitness of the selected model for analyzing the experimental data.
Application of AIM Parameters at Ring Critical Points for Estimation of π‐Electron Delocalization in Six‐Membered Aromatic and Quasi‐Aromatic Rings
Authors: Palusiak Marcin , Krygowski Tadeusz M.
Published: July 2007

The AIM parameters at thering critical point(the electron density and its Laplacian, the total electron energy density and both its components, potential and kinetic electron energy densities), have been intercorrelated with aromaticity indices: the geometry‐based HOMA and the magnetism‐based NICS, NICS(1), and NICS(1)zz. A set of 33 phenylic rings having possibly a diversified aromatic character, and a set of 20 quasi‐rings formed by intramolecular hydrogen and lithium bonds, have been taken into consideration. It has been found that the density of total electron energy,H, may serve as a new quantitative characteristic of π‐electron delocalization. The dependences betweenHvalues and aromaticity indices are correlated (ccH/HOMA=0.99, ccH/NICS(1)zz=0.95).
Efficacy and safety of imatinib in patients with chronic myeloid leukemia and complete or near‐complete cytogenetic response to interferon‐α
Authors: Branford Susan , Hughes Timothy , Milner Alvin , Koelmeyer Rachel , Schwarer Anthony , Arthur Chris , Filshie Robin , Moreton Susan , Lynch Kevin , Taylor Kerry
Published: July 2007

BACKGROUND.

Interferon‐alpha (IFN‐α) confers a survival advantage for the minority of patients with chronic myeloid leukemia (CML) who achieve a complete cytogenetic response. The question of whether IFN‐α‐responsive patients can experience further improvements with imatinib has not been answered. Imatinib offers clear quality of life advantages. Furthermore, patients who achieve a major molecular response (MMR) while receiving imatinib are likely to remain progression free.

METHODS.

A total of 23 patients treated for a median of 4.5 years with IFN‐α (range, 1.6–14.3 years) who had achieved a complete (Philadelphia chromosome [Ph] negative, n = 15 patients) or near‐complete (1–10% Ph, n = 8 patients) cytogenetic response were studied. The primary objective was to determine whether ceasing therapy with IFN‐α and switching to 12 months of imatinib treatment at a dose of 400 mg/day could improve the molecular response as assessed by real‐time quantitative polymerase chain reaction of BCR‐ABL transcript levels. Safety was also assessed.

RESULTS.

Every patient who had not achieved an MMR while receiving IFN‐α (n = 16 patients) achieved an MMR after a median of 3 months of imatinib treatment. Significant BCR‐ABL reductions (median, 63‐fold; range, 18–425‐fold) occurred in 15 of these patients. Every patient who had already achieved an MMR while receiving IFN‐α (n = 7 patients) maintained an MMR while receiving imatinib. No patients discontinued imatinib due to toxicity, but 1 patient withdrew consent.

CONCLUSIONS.

These data suggest that switching IFN‐α‐responsive patients to imatinib leads to a rapid improvement in achieving an MMR, a response with established prognostic value, and is well tolerated. The study should help patients and their physicians make evidence‐based decisions regarding the potential benefits and risks of switching to imatinib. Cancer 2007. © 2007 American Cancer Society.
Cost effectiveness of mammography screening for Chinese women
Authors: Wong Irene O. L. , Kuntz Karen M. , Cowling Benjamin J. , Lam Cindy L. K. , Leung Gabriel M.
Published: July 2007

BACKGROUND.

Although the cost effectiveness of screening mammography in most western developed populations has been accepted, it may not apply to Chinese women, who have a much lower breast cancer incidence. The authors estimated the cost effectiveness of biennial mammography in Hong Kong Chinese women to inform evidence‐based screening policies.

METHODS.

For the current study, a state‐transition Markov model was developed to simulate mammography screening, breast cancer diagnosis, and treatment in a hypothetical cohort of Chinese women. The benefit of mammography was modeled by assuming a stage shift, in which cancers in screened women were more likely to be diagnosed at an earlier disease stage. The authors compared costs, quality‐adjusted life years (QALYs) saved, and life years saved (LYS) for 5 screening strategies.

RESULTS.

Biennial screening resulted in a gain in life expectancy ranging from 4.3 days to 9.4 days compared with no screening at an incremental cost of from US$1166 to US$2425 per woman. The least costly, nondominated screening option was screening from ages 40 years to 69 years, with an incremental cost‐effectiveness ratio (ICER) of US$61,600 per QALY saved or US$64,400 per LYS compared with no screening. In probabilistic sensitivity analyses, the probability of the ICER being below a threshold of US$50,000 per QALY (LYS) was 15.3% (14.6%).

CONCLUSIONS.

The current results suggested that mammography for Hong Kong Chinese women currently may not be cost effective based on the arbitrary threshold of US$50,000 per QALY. However, clinicians must remain vigilant and periodically should revisit the question of population screening: Disease rates in China have been increasing because of westernization and socioeconomic development. Cancer 2007. © 2007 American Cancer Society.
Serum Aspergillus galactomannan antigen values strongly correlate with outcome of invasive aspergillosis
Authors: Woods Gail , Miceli Marisa H. , Grazziutti Monica L. , Zhao Weizhi , Barlogie Bart , Anaissie Elias
Published: July 2007

BACKGROUND.

Determining the outcome of patients with aspergillosis can be particularly difficult because patients with aspergillosis are at risk for other conditions that mimic this infection. Galactomannan is an Aspergillus‐specific antigen released during invasive aspergillosis and is detected by the quantitative serum galactomannan index (GMI) test.

METHODS.

Using a kappa correlation coefficient test (KCC), the strength of correlation was determined between GMI and survival outcome of aspergillosis among 56 adults with hematologic cancer (90% had myeloma) who underwent serial GMI monitoring until hospital discharge or death.

RESULTS.

All 56 patients received antineoplastic therapy (myeloablative followed by stem cell transplantation [autologous in 21 patients and allogeneic in 3 patients] or nonmyeloablative therapy [32 patients]). The overall correlation between survival outcome and GMI was excellent (KCC = 0.8609; 95% confidence interval [95% CI], 0.7093–1.000 [P < .0001]) and was comparable among neutropenic and nonneutropenic patients (KCC = 0.8271; 95% CI, 0.6407–1.000 [P < .0001] and KCC = 1.0; 95% CI, 1–1 [P = .0083], respectively).

CONCLUSIONS.

The survival outcome of patients with aspergillosis strongly correlated with serum GMI. These findings have important implications for patient care and clinical trials of mold‐active antifungal agents. Cancer 2007; 110:830–4. © 2007 American Cancer Society.
The stabilization of two‐dimensional non‐symmetric half‐plane recursive filters via the discrete Hilbert transformations
Authors: Reddy C. R. , Sathyanarayana P. , Swamy M. N. S.
Published: July 2007

The discrete Hilbert transform (DHT) relations for 2D semicausal signals have been introduced. an alternative algorithm to stabilize non‐symmetric half‐plane (NSHP) recursive filters by applying the DHT directly in the nonsymmetric half‐plane is presented. the results of the direct DHT (DDHT) stabilization procedure are compared with the method of quarter‐plane DHT (QDHT) stabilization after transforming the NSHP polynomial into the quarter‐plane by application of an appropriate transformation. It is observed that the proposed scheme produces the same stable NSHP filter as that obtained through the QDHT method.
Method of analysis of non‐linear systems on the basis of generalization of the volterra functional series relative to complex envelopes
Authors: Kabanov D. A. , Zaytsev A. N.
Published: July 2007

The paper considers the mathematical modelling of weakly non‐linear narrow‐band circuits and systems on the basis of application of the Volterra functional series. the investigation uses multidimensional pulse and transfer functions as well as the Volterra functional series relative to the narrow‐band signal envelopes. Examples are given of the construction of Volterra kernels of narrow‐band non‐linear circuits and systems.
A Mixed‐Mode Analogue and Switch Level Simulator
Authors: Menzel S. P. , Vlach J.
Published: July 2007

This paper describes an experimental mixed‐mode simulation system which couples an incremental time analogue simulator to an event‐driven switch level simulator. the analogue timing programme uses a variable‐step‐size, multi‐order (VSMO) numerical integration algorithm which detects and uses latency while maintaining wave‐form synchronization. the switch level programme uses piecewise linear wave‐forms rather than discrete states to model the operation of logical networks. A unified format in which time responses are events is used for communication between the two programmes. the mixed‐mode simulator operates without backtracking or translation between logical states and analogue wave‐forms.
A general theory for broad‐band matching of two‐ports with applications to fet amplifiers with internal feedback
Authors: Carlin Herbert J. , Civalleri Pier Paolo
Published: July 2007

We prove that the problem of broad‐band matching an arbitrary linear two‐port to resistive terminations by means of input and output lossless equalizers can be reduced to two passive load single‐matching problems by weighting partial gains due to each equalizer with suitable frequency functions.

We apply the technique to the problem of determining the maximum of an ideal rectangular gain function for an FET amplifier with internal feedback and losses. the solution is exact for zero feedback. For finite feedback the ideal input‐equalized gain is exact whereas the output least upper bound is approximate. the results in effect provide a figure of merit for a given FET which is a useful yardstick against which practical designs can be evaluated. Some numerical results are presented.
A chebyshev rational function with low Q‐factors
Authors: Rabrenović D. , Lutovac M.
Published: July 2007

The presented rational function is a modification of a recently published Chebyshev rational function defined by means of some orthogonal polynomials. the necessary conditions providing for the lowest pole Q‐factors for a given ripple are found. the function is a ratio of two similar Chebyshev polynomial transfer functions with multiple poles.

The selectivity of the function can be increased by using the Chebyshev rational characteristic function instead of the characteristic polynomials. the minimum number of active elements in the cascade connection is obtained with third‐order elliptic characteristic functions.

The function is compared with the Cauer (elliptic) and MCPER filters. the distinctive features of the presented function are small Q‐factors of the poles, almost ideal dynamic range, simple design and poles with the same multiplicity m, where m designates the number of cascaded blocks.
Development of a new stabilized four‐phase oscillator based on partial conservativity
Authors: Kaplan B. Z. , Yardeni D.
Published: July 2007

The paper treats the development of a non‐linearly stabilized oscillator model for generating four sine waves in quadrature. the treatment appears important although quadrature signals can also be generated by a well‐known twophase oscillator. the latter generates only two of the signals needed in a four‐phase system, but the rest of the phases signals could nevertheless be generated by simply inverting the two existing signals. For certain applications, however, the generation of all four signals in a completely cyclic and symmetrical manner is preferable. This method of generation is dealt with in the present paper. A previous paper of ours has treated a system of a similar objective. the present system, however, is much simpler. This simplicity is manifested not only through the mathematical representation but also when an electronic realization of the system is considered. the present model realization appears considerably less expensive, since the number of necessarily non‐linear operations is much reduced. This reduction is due to the fact that the non‐linearly stabilized model imbeds a ‘partially conservative’ linear oscillator. the concept of ‘partial conservativity’ has been introduced recently. the present work treats comprehensively the advantages that are gained by imbedding a partially conservative oscillator.
An equivalent circuit for the analysis of transmission line matrix (tlm) scattering algorithms
Authors: Saleh A. H. M. , de Cogan D.
Published: July 2007

The transmission line matrix (TLM) method is a technique which is widely used for modelling physical phenomena. This paper outlines an equivalent‐circuit model based on the superposition of current and voltage source contributions.
Low‐sensitivity SC realization of brune and C‐type reactance sections
Authors: Fahmy M. F. , El‐Wardaney A. , Raheem G. A. , Fattah F. A.
Published: July 2007

The SC implementation of doubly terminated reactance reference filters containing Brune or C‐type sections is presented. It is shown that the one‐to‐one correspondence between the elements of the reactance reference network and its simulated SC circuit is still maintained. Computer evaluations as well as experimental verifications have shown that the resulting structure is less sensitive with respect to parasitics. Illustrative examples are given.
Extension of a driving‐point and a transfer function to a positive real two‐port matrix
Authors: Martens G. O. , Unbehauen R.
Published: July 2007

A solution is presented to the problem, which arises in two‐port modelling, of determining a second driving‐point function from a given driving‐point function and a transfer function. the given functions must have a common denominator and satisfy the necessary positive real (PR) matrix conditions: the driving‐point function must be PR and on the imaginary axis the real part of the transfer function must be zero whenever the real part of the driving‐point function is zero. By using a partial fraction expansion and determining a required first‐order polynomial, a unique second (minimum) driving‐point function is obtained. Examples to illustrate the method are worked out.
Circuit macromodels and large‐signal behaviour of fet‐input operational amplifiers
Authors: Golzio D. , Graffi S. , V.‐Kovács Zs. M. , Masetti G.
Published: July 2007

The origin of the slew rate asymmetry found experimentally in FET‐input LF355 op amps is analysed in order to explain why macromodels based on a strict build‐up technique can fail when used to simulate the behaviour of amplifiers driven by out‐of‐band large voltage signals. These simulations may be very important in predicting the effects of electromagnetic interferences conveyed to the circuit input port. Other performances of op amp macromodels designed either by build‐up techniques or by simplification/build‐up techniques are also compared and discussed.
Relaxation‐based computation of a synchronous sequential circuit stable state
Authors: Diouf Magatte , Carlin Charles‐Henri
Published: July 2007

To perform a mixed mode analysis with the electrical and gate levels in the waveform relaxation context, an initial steady state of the analysed circuit must be computed prior to transient analysis. By using Boolean algebra and discrete relaxation, we propose various algorithms to compute a stable state or a stable total state of a logic synchronous sequential system with master‐slave flip‐flops. Furthermore, a dynamic ordering of the logic gates which improves the convergence of the computation of a stable total state is presented. We show that a stable state can be calculated within only two iterations.
SMOS: A CAD‐compatible statistical model for analogue mos integrated circuit simulation
Authors: Michael Christopher , Abel Christopher , Ismail Mohammed
Published: July 2007

An analogue CAD tool capable of simulating MOS circuit performance variance caused by intra‐die variability inherent to IC fabrication processes has been developed. the nucleus of this tool is a general, CAD‐compatible, MOS statistical model called SMOS which comprehends the effects of device geometry, circuit layout and transistor bias on parameter variance. an example of the model calculation procedure is presented to illustrate both the modelling algorithms and the process characterization data required by the statistical model. the statistical model is verified through experimental data which show excellent agreement with performance variances predicted by simulation. Implementations of the statistical model in two circuit simulation environments, SPICE and APLAC, are also described. Statistical analysis and simulation of two basic analogue subcircuits, the current mirror and the source‐coupled pair, are presented.
Cellular neural networks with non‐linear and delay‐type template elements and non‐uniform grids
Authors: Roska Tamás , Chua Leon O.
Published: July 2007

The cellular neural network (CNN) paradigm is a powerful framework for analogue non‐linear processing arrays placed on a regular grid. In this paper we extend the current repertoire of CNN cloning template elements (atoms) by introducing additional non‐linear and delay‐type characteristics. In addition, architectures with non‐uniform processors and neighbourhoods (grid sizes) are introduced. With this generalization, several well‐known and powerful analogue array‐computing structures can be interpreted as special cases of the CNN. Moreover, we show that the CNN with these generalized cloning templates has a general programmable circuit structure (a prototype machine) with analogue macros and algorithms. the relations with the cellular automaton (CA) and the systolic array (SA) are analysed. Finally, some robust stability results and the state space structure of the dynamics are presented.
A path‐following method for finding multiple equilibrium points in cellular neural networks
Authors: Vandenberghe Lieven , Vandewalle Joos
Published: July 2007

Owing to the piecewise linear character of the non‐linearities, the computation of equilibrium points in a cellular neural network could be accomplished in a trivial way by solving 3nlinear systems (wherenis the number of neurons). This is clearly infeasible even for moderatenand it is the purpose of this paper to present a more efficient path‐following method for computing equilibrium points. the method is guaranteed to find at least one solution. the possibility of finding all solutions is also investigated and this leads to new theoretical insight to the relation between the properties of the interconnection matrix and the number of equilibrium points.
Neural networks for constrained optimization problems
Authors: Lillo Walter E. , Hui Stefen , Żak Stanislaw H.
Published: July 2007

This paper is concerned with utilizing neural networks and analogue circuits to solve constrained optimization problems. We propose a novel neural network architecture for solving a class of non‐linear programming problems. the proposed neural network is then used, and if necessary modified, to solve minimum norm problems subject to linear constraints. Minimum norm problems have many applications in various areas, but we focus on their applications to the control of discrete dynamic processes. the applicability of the proposed neural network is demonstrated on numerical examples.
A class of non‐canonic, driving‐point immittance realizations of passive, common‐ground, transformerless, two‐element‐kind RLC networks
Authors: Kandic Dragan , Reljin Branimir
Published: July 2007

A new class of non‐canonic, driving‐point immittance realizations of passive, common‐ground, transformerless, two‐element‐kind RLC networks with minimum number of nodes is presented. Six new algorithms of realization are developed by application of canonic, orthogonal matrix transformations with reduced number of degrees of freedom. the number of applied RLC elements of one kind can be minimized and of the other kind reduced, while their parameter values are calculated directly in a linear way.
An algorithm for solving the equations of monotone non‐linear resistive networks
Authors: Sandberg Irwin W.
Published: July 2007

An algorithm related to the PQ theorem is given for solving the equations of a large class of monotone non‐linear resistive networks. the algorithm converges to a solution whenever a solution exists, while it produces an unbounded sequence of iterates if there is no solution.
Simple yet accurate current copiers for low‐voltage current‐mode signal‐processing applications
Authors: Huang Renyuan , Wey Chin‐Long
Published: July 2007

As pressures increase on VLSI designers to use a lower supply voltage of 3.3 V rather than the present 5 V, currentmode signal‐processing techniques will surely become increasingly important and attractive. Numerous current copiers have been proposed. Among them, the copier with a negative feedback approach is the best candidate for low‐voltage current‐mode signal‐processing applications. However, the copier using a positive‐gain feedback amplifier achieves better accuracy at the cost of increasing circuit complexity and settling time. This paper presents an alternative circuit implementation of the negative feedback approach. the proposed current copier uses a negative‐gain feedback amplifier which can be easily realized by a simple circuitry with high accuracy and faster settling time. Simulation results show that with the simple digital CMOS process the proposed copier can be realized with only three transistors, achieves a dynamic range from 300 to 550 μA with an accuracy of 0.1% and can be settled within 3 ns with a power supply of 3.3 V. Thus the copier is well suited to our low‐voltage current‐mode sensor array applications.
Chaos from a current‐programmed ćuk converter
Authors: Tse C. K. , Chan W. C. Y.
Published: July 2007

The chaotic dynamics of a current‐programmed Ćuk converter having no voltage feedback is studied. an iterative map that describes the operation of the circuit is derived, from which a route to chaos similar to that from a ‘tent’ map is predicted. Computer simulation based on an exact piecewise switched model confirms the predicted route to chaos.
Darwin: Analogue circuit synthesis based on genetic algorithms
Authors: Kruiskamp Wim , Leenaerts Domine
Published: July 2007

DARWIN is a synthesis tool for generating sized net lists of CMOS op amps from performance specifications and process parameters. the synthesis process starts with an initial set of randomly generated op amps. Owing to genetic operator ‘crossover’ and ‘mutation’, the population of op amps evolves to a population in which several op amps meet the required specifications. During the synthesis process the circuit topology and circuit parameters (capacitor values, bias currents and transistor lengths and widths) evolve simultaneously with the final solution. the circuit description we use in the genetic algorithm ensures that all intermediately generated circuits possess a number of qualities that are required for a correct functioning of the circuit. Synthesis experiments have shown that DARWIN is capable of synthesizing functional circuits without the need of much design knowledge.
A modified sensitivity measure for linear digital systems
Authors: Xiao Chengshan
Published: July 2007

In this paper a new sensitivity measure for state space systems is proposed. This new measure is a modified form of Tavsanoglu and Thiele's measure but has three advantages: (1) it is more precise than Tavsanoglu and Thiele's measure when the parameters of the state space realizations contain 0 and ±1; (2) it can be used to explain why the sparse Schur and Hessenberg realizations can give better actual sensitivity performance than the corresponding fully parametrized optimal realizations; (3) it is identical with the global round‐off noise gain G = tr(QW) + y obtained by Hwang under a dynamic constraint.
CYP2R1 (vitamin D 25‐hydroxylase) gene is associated with susceptibility to type 1 diabetes and vitamin D levels in Germans
Authors: Ramos‐Lopez Elizabeth , Brück Patrick , Jansen Thomas , Herwig Jürgen , Badenhoop Klaus
Published: July 2007

Background

The vitamin D system has been implicated in type 1 diabetes by epidemiological and immune intervention studies as well as by polymorphisms of the vitamin D binding protein (DBP) and CYP27B1 genes. CYP2R1, a cytochrome P450 enzyme, catalyzes the formation of vitamin D3 to 25‐hydroxyvitamin D3 (25(OH)D3), the main circulating vitamin D metabolite.

Methods

Two hundred and three simplex type 1 German diabetes families (609 subjects) were genotyped for the rs10741657 and for the rs12794714 polymorphisms. 25(OH)D3 levels were measured and correlated with CYP2R1 polymorphisms in 133 type 1 diabetes patients as well as its mRNA expression from peripheral blood mononuclear cells (PBMCs) in 58 type 1 diabetes patients.

Frequencies and genotypes of the CYP2R1 polymorphisms were analyzed using Haploview software version 3.2. The correlation between 25(OH)D3 and CYP2R1mRNA with the genotypes of the rs10741657 and rs12794714 polymorphism was evaluated by Wilcoxon‐Mann–Whitney‐ and ANOVA test using Bias Statistical package 7.01.

Results

Whereas the rs12794714 polymorphism was not associated with type 1 diabetes the variant ‘G’ of the rs10741657 polymorphism was more often transmitted to affected offspring (61% vs 39% P = 0.004) and was also more frequent in cases than in controls (46.1% vs 35.7%, P = 0.03).

Patients carrying the genotype ‘GG’ or ‘GA’ of the rs10741657 polymorphism possessed, on average, lower levels of 25(OH)D3 compared to those with the genotype ‘AA’ (P = 0.003, Pc = 0.01 and P = 0.01, Pc = 0.04, respectively).

Conclusion

Thus, our findings reveal a novel association of CYP2R1 polymorphisms in patients with type 1 diabetes and with their circulating levels of 25(OH)D3. Copyright © 2007 John Wiley & Sons, Ltd.
The use of multiple purging methods as an indicator of eating disorder severity
Authors: Edler Crystal , Haedt Alissa A. , Keel Pamela K.
Published: July 2007

Objective:

Previous studies indicate a distinction between those who use one versus multiple methods of purging, but these studies have not controlled for differences in purging frequency. The current study examined whether purging frequency or the use of multiple purging (MP) methods provides more information about eating disorder severity.

Method:

Existing data were reanalyzed to examine associations between facets of purging and psychological measures among women with bulimia nervosa, purging disorder, and controls. Analyses compared the use of MP methods and purging frequency as indicators of eating pathology.

Results:

MP methods demonstrated associations with greater eating disorder severity; purging frequency was associated with increased binge frequency and general psychopathology.

Conclusion:

The presence of MP methods provides more information about eating disorder severity than purging frequency, which seems to be a marker of related psychopathology. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007
The influence of success and failure experiences on agency
Authors: Abele Andrea E. , Rupprecht Thomas , Wojciszke Bogdan
Published: July 2007

Agency is—besides communion—a basic dimension of traits. It can be specifically linked to behavioral outcomes, to status, mastery, self‐esteem and to success. The present paper analyzes the situational malleability of agency. Two studies tested whether an individual's agency (but not communion) is situationally influenced by the experience of success versus failure at a task, as well as whether this effect is the same for men and women. Supporting our hypotheses, the induction of success versus failure experiences led to changes in agency that were independent of actual performance, independent of type of task (memorizing vs. face recognition), independent of induction methodology (easy vs. difficult task vs. manipulated performance feedback), and independent of self‐esteem, initial level of agency and of the participants' gender. Communion was not influenced by this kind of experience. Implications for both the basic dimension of agency and for theories on gender and gender stereotypes are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Motivated self and recall: visual perspectives in remembering past behaviors
Authors: Sanitioso Rasyid Bo
Published: July 2007

The present study examined motivational influences on visual perspectives in remembering past events and behaviors. Participants were first induced to believe that extraversion or introversion is conducive of success. Next, they recalled in details two introverted past behaviors. Introversion‐success participants, presumably motivated to see themselves as introverted, recalled and visualized the behaviors more from a first‐person actor perspective than did extraversion‐success participants (who recalled the behaviors from a third‐person observer perspective). Remembering past behaviors from a first‐person actor perspective implies that the behaviors are true of the self and impacts self‐definition to a relatively greater degree. The findings thus extend the influence of desired self to how people remember past events. They also contribute to the integration of motives in research on the link between self‐inferences and the subjective experience of remembering. Copyright © 2007 John Wiley & Sons, Ltd.
Pilot scale SO2 control by dry sodium bicarbonate injection and an electrostatic precipitator
Authors: Pilat Michael J. , Wilder James M.
Published: July 2007

A 500 actual cubic feet gas per minute (acfm) pilot‐scale SO2 control study was undertaken to investigate flue gas desulfurization (FGD) by dry sodium sorbents in 400°F (204.5°C) flue gases emitted from a coal fired boiler with flue gas concentrations between 350 and 2500 ppm SO2. Powdered sodium alkaline reagents were injected into the hot flue gas downstream of the air preheater and the spent reagents were collected using an electrostatic precipitator. Three different sorbents were used: processed sodium bicarbonate of two particle sizes; solution mined sodium bicarbonate, and processed sodium sesquicarbonate. SO2 concentrations were measured upstream of the reagent injection, 25‐ft (7.62 m) downstream of the injection point, and downstream of the electrostatic precipitator. SO2 collection efficiencies ranged from 40 to 80% using sodium bicarbonate stoichiometric ratios from 0.5 to 3.0. Much of the in‐duct SO2 removal occurred during the first second of reagent reaction time, indicating that the sulfur dioxide–sodium reaction rates may be faster than have been measured for fixed bed measurements reported in the literature. © 2007 American Institute of Chemical Engineers Environ Prog, 2007
A combined S‐transform and fuzzy expert system for phase selection in digital relaying
Authors: Samantaray S. R. , Dash P. K. , Panda G.
Published: July 2007

This paper presents a new approach for faulty phase selection in transmission line based on combined S‐transform and Fuzzy Expert System (FES). The S‐transform with complex window is used to generate S‐contours (time–frequency contours), which ‘time‐localizes’ the fault. Features such as standard deviation (sd) and change in energy (ce) of the S‐contours for half cycle post fault current samples are calculated and fuzzified with simple triangular membership function. The fuzzified inputs are fed to the FES and the corresponding fuzzy rule is fired to provide the output as “1” for faulty phase and ground involved and “0” for no‐fault. The proposed integrated approach is tested for all 11 types of shunt faults with a wide range of operating conditions of the power system network. For testing the robustness of the proposed technique, the same is applied for the faults created on experimental set up with different operating conditions and provides accurate results. The output from the FES shows the fastness of the proposed technique and thus suitable for online application. Copyright © 2007 John Wiley & Sons, Ltd.
Flux variation in a Siberian taiga forest near Yakutsk estimated by a one‐dimensional model with routine data, 1986–2000
Authors: Yamazaki Takeshi , Ohta Takeshi , Suzuki Rikie , Ohata Tetsuo
Published: July 2007

For a larch forest site near Yakutsk, energy and water fluxes are estimated and their variations are investigated using a one‐dimensional land surface model with daily routine data. The estimation period is 1986–2000, including the period before the start of tower observation (1997) on the left bank of the Lena River. The land surface model includes three submodels: vegetation, snow cover, and soil. The model can calculate water and energy fluxes above and within the forest if meteorological data over the forest are given as input. Data used in this study are Baseline Meteorological Data in Siberia (BMDS) Version 3. This set comprises daily data of main meteorological elements. The procedure is as follows: (1) preparation of equations between routine Yakutsk data and larch tower data; (2) estimation of past meteorological data over the taiga using those equations; and (3) estimation of fluxes using the one‐dimensional model. The date of leaf‐out start is parameterized with soil temperature and accumulated air temperature. It corresponds to the green‐up time obtained from satellite normalized difference vegetation index (NDVI) data. Estimated monthly deviation of net radiation, Rn, is 10 Wm−2. Its maximum is 20 Wm−2. The monthly deviation of latent heat flux, LE, is less than 12 Wm−2. Its warm season average is less than 7 Wm−2. Although the magnitude of LE is almost zero in December and January, and several Wm−2 aside from these 2 months, the sensible heat flux, H, sometimes becomes negative during the cold season. The variation of evapotranspiration is considerably smaller than that of precipitation. The evapotranspiration (E) normalized by potential evaporation (Ep), E/Ep is 0·37–0·44 in the warm season; it tends to be large when leaf‐out starts early. The amount of evapotranspiration in the warm season can be estimated from Ep within an error of 5 mm using this relationship. Copyright © 2007 John Wiley & Sons, Ltd.
Osteoblast adhesion and morphology on TiO2 depends on the competitive preadsorption of albumin and fibronectin
Authors: Sousa S. R. , Lamghari M. , Sampaio P. , Moradas‐Ferreira P. , Barbosa M. A.
Published: July 2007

This study aims at assessing the influence of the competitive preadsorption of human serum albumin (HSA) and human plasma fibronectin (FN) from binary solutions and 10% plasma on MC3T3‐E1 osteoblast adhesion and morphology on two types of TiO2 substrates. One was commercially pure titanium with a titanium oxide layer formed in an H2O2 solution and the other TiO2 sputtered on Si (Sousa et al., Langmuir 2004; 20:9745–9754.). The strategy applied in the present investigation was to compare osteoblast adhesion to surfaces preadsorbed with HSA, FN, HSA/FN = 1, HSA/FN = 200, and 10% plasma. The adsorption of proteins was evaluated measuring the amount and the effectiveness of binding with radiolabeled proteins, 125I‐FN and 125I‐HSA. Our results indicated that MC3T3‐E1 osteoblast adhesion correlates well with the amounts of FN and HSA adsorbed on TiO2 surfaces. Also, we found that fewer osteoblasts adhered to both substrates preadsorbed with HSA, HSA/FN = 200, and 10% plasma, after 4 and 24 h, than to the surfaces preadsorbed with FN and HSA/FN = 1. For the latter, FN was able to compensate the inhibitory effect of HSA on osteoblast adhesion. Therefore, the presence of lower amounts of coadsorbed albumin may improve presentation of FN in a more integrin‐recognized conformation, suggesting that some degree of molecular packing prevents loss of integrin‐binding activity. FN reversibility does not seem to be dependent on the HSA/FN adsorption mass ratio in solution, suggesting that FN competitively adsorbs to TiO2 in a favorable conformation and does not suffers subsequent conformational changes allowing exchange with other FN molecules in solution. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Matrix metalloproteinases and their inhibitors in the foreign body reaction on biomaterials
Authors: Jones Jacqueline A. , McNally Amy K. , Chang David T. , Qin L. Abigail , Meyerson Howard , Colton Erica , Kwon I.L. Keun , Matsuda Takehisa , Anderson James M.
Published: July 2007

Matrix metalloproteinases (MMPs) can degrade structural components within the extracellular matrix and at the cellular surface producing changes in cellular behavior (i.e., adhesion and migration) and subsequent pathological responses (i.e., the foreign body reaction and wound healing). We continue to study the foreign body reaction that occurs following biomaterial implantation by investigating secretory responses of biomaterial‐adherent macrophages and foreign body giant cells (FBGCs) as directed by material surface chemistry and further this research by determining whether secreted MMPs play a role in macrophage adhesion and fusion. We have identified numerous MMPs and their tissue inhibitors (TIMPs) in in vitro cell‐culture supernatants using antibody arrays and quantified select MMP/TIMPs with ELISAs. MMP‐9 concentrations were significantly greater than both TIMP‐1 and TIMP‐2 on all materials. The ratios of MMP‐9/TIMP‐1 and MMP‐9/TIMP‐2 increased with time because of an increase in MMP‐9 concentrations over time, while the TIMP concentrations remained constant. Total MMP‐9 concentrations in the supernatants were comparable on all materials at each timepoint, while TIMP‐1 and TIMP‐2 concentrations tended to be greater on hydrophilic/anionic surfaces. Analysis of the MMP/TIMP quantities produced per cell revealed that the hydrophilic/neutral surfaces, which inhibited macrophage adhesion, activated the adherent macrophages/FBGCs to produce a greater quantity of MMP‐9, TIMP‐1, and TIMP‐2 per cell. Pharmacological inhibition of MMP‐1,‐8,‐13, and ‐18 reduced macrophage fusion without affecting adhesion, while inhibitors of MMP‐2,‐3,‐9, and ‐12 did not affect adhesion or fusion. These findings demonstrate that material surface chemistry does modulate macrophage/FBGC‐derived MMP/TIMP secretion and implicates MMP involvement in macrophage fusion. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Effect of weight‐bearing on bone‐bonding behavior of strontium‐containing hydroxyapatite bone cement
Authors: Ni G.X. , Lu W.W. , Tang B. , Ngan A.H.W. , Chiu K.Y. , Cheung K.M.C. , Li Z.Y. , Luk K.D.K.
Published: July 2007

The purpose of this study was to investigate and compare the chemical composition and nanomechanical properties at the bone‐cement interface under non‐weight‐bearing and weight‐bearing conditions, in order to understand the effect of weight‐bearing on the bone‐bonding behavior of strontium‐containing hydroxyapatite (Sr‐HA) cement. In one group, Sr‐HA cement was injected into rabbit ilium (under non‐weight‐bearing conditions). Unilateral hip replacement was performed with Sr‐HA cement (under weight‐bearing conditions) in the other group. Six months later, scanning electron microscopy (SEM) with energy‐dispersive X‐ray (EDX) analysis and nanoindentation tests were conducted on the interfaces between cancellous bone and the Sr‐HA cement. The nanoindentation results revealed two different transitional behaviors under different conditions. nder weight‐bearing conditions, both the Young modulus and hardness at the interface were considerably higher than those at either the Sr‐HA cement or cancellous bone. On the contrary, under non‐weight‐bearing conditions, both the Young modulus and hardness values at the interface were lower than those at the cancellous bone, but were higher than the Sr‐HA cement. In addition, EDX results showed that the calcium and phosphorus contents at the interface under weight‐bearing conditions were considerably higher than those under non‐weight‐bearing conditions. The differences in chemical composition and nanomechanical properties at the cement‐bone interface under two different conditions indicate that weight‐bearing produces significant effects on the bone‐bonding behavior of the Sr‐HA cement. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007