bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the dimensionality of spectroscopic data by submatrix analysis
Authors: Cartwright Hugh 
Published: May 2005

AbstractIn the treatment of spectroscopic data by principal component analysis, correct determination of the dimensionality of the data is essential. Submatrix analysis, which involves preliminary analysis of subsets of the data matrix, is described, and shown to be valuable in determining both the size of the factor space and estimates of equilibrium constants in the system, even for data containing abnormally large experimental error.
Relationships between higher‐order data array configurations and problem formulations in multivariate data analysis
Authors: Esbensen Kim. H. , Wold Svante , Geladi Paul 
Published: May 2005

AbstractA scaffold for detailed understanding of the concept ‘dimensionality’ in data analysis is furnished by a systematic classification of higher‐order data array configurations. Three major types of problem formulation in multivariate data analysis can be characterized for relevant data classes:

data description (intra‐class data structure modelling of inter‐object and inter‐variable relationships)
classification (inter‐class discrimination)
correlation, regression (inter‐variable relationships).
The relationship between these three categories of data analytical problem formulation and the fundamental data array classification is exposed. These relations are augmented to include the general case of data arrays of order R, and R‐way data analysis with the use of bilinear projections is presented. Based upon this, some possible directions for the future development of data analysis may be imagined.
A test of three fitting criteria for multiresponse non‐linear modeling
Authors: Pell Randy J. , Kowalski Bruce R. 
Published: May 2005

AbstractThis work evaluates objective functions for multiresponse non‐linear modeling using computer simulations. Tests are performed under a variety of signal‐to‐noise ratios and noise variance–covariance structures. The standard error of prediction for the model parameters, computed from 50 trials, is used for performance comparisons. The full rank and rank‐deficient problems are considered. For the full rank problem one model was investigated, a first‐order two‐step consecutive reaction model, and two objective functions were considered, the total sum of squares and the determinant criterion. No distinction could be made between the two objective functions for this model.For the rank‐deficient case two models were investigated, a first‐order two‐step consecutive reaction as in the full rank case, and a pH titration model described by the Henderson–Hasselbalch equation. Three objective functions were investigated for the rank‐deficient case, the total sum of squares, a weighted total sum of squares and the determinant criterion. The total sum of squares was found to perform poorly under all conditions tested compared to the weighted total sum of squares and the determinant criterion. The determinant criterion was found to perform much better than the other two criteria when the data have a combination of a low signal‐to‐noise ratio and high variance–covariance noise structure.
Comparison of pattern recognition descriptors for chemical acoustic emission analysis
Authors: Wentzell Peter D. , Lee Oliver , Wade Adrian P. 
Published: May 2005

AbstractFeatures used to characterize acoustic emission signals from chemical systems are evaluated with regard to their potential for pattern recognition. Eight chemical systems involving phase transitions, hydration, dissolution and effervescence are employed and treated as separate signal classes. These are compared pairwise and the discriminatory capabilities of about 50 features are investigated by computing Fisher weights. Time domain and frequency domain descriptors are examined. Correlations among the features evaluated are also reported. Recommended descriptors are the mean and median frequencies, frequency bandwidth, number of level crossings (0% and 25%), crest factor (time and frequency domains), half‐life, kurtosis and normalized percentiles of the signal and its power spectrum. The effectiveness of the recommended descriptors is demonstrated through the separation of signal classes in two different systems (melting ice and an enzyme‐catalyzed gas formation reaction) by principal components analysis.
Computer‐generated multicomponent calibration designs for optimal analysis sample predictions
Authors: Hitchcock Kimberly , Kalivas John H. , Sutter Jon M. 
Published: May 2005

AbstractThis paper utilizes variable step size generalized simulated annealing (VSGSA) to design multicomponent calibration samples for spectroscopic data. VSGSA is an optimization procedure which is capable of converging to exact positions of global optima located on multidimensional continuous functions. On the basis of analysis sample response vectors, optimally designed calibration concentration matrices are obtained assuming knowledge of components present. The complexity of response surfaces established by the optimization criteria is described.
The ectal relations of the right and left parietal and paroccipital fissures
Authors: Wilder B. G. 
Published: May 2005

AbstractThe parietal and paroccipital fissures may be either completely separated by an isthmus, or apparently continuous. When so continuous ectally there may still be an ental and concealed vadum or shallow. Disregarding the vadum on the present occasion, the ectal relations of the two fissures may be designated as either continuity or separation. That continuity occurs more frequently on the left side has been noted by Ecker, Cunningham and the writer. Hitherto, however, statistics have included unmated hemicerebrums as well as mates from the same individuals. The following statement is based upon the cerebrums of 58 adults of both sexes and various nationalities and characters. The speaker has examined 48; the other 10 have been accurately recorded by Bischoff, Dana, Jensen and Mills.The four possible combinations of right and left continuity and separation occurred as follows:

Left continuity and right separation in 27; 46.5%.
Right and left continuity in 22; 38%.
Right and left separation in 8; I 3.8%.
Left separation and right continuity in I; I.7%.
When 5 groups of persons are recognized the combinations are as follows:

In 8 moral and educated persons, combination I, 62.5; II, 25; III, 12.5.
In 23 ignorant or unknown, I, 56.5; II, 34.8; III, 8.7.
In 20 insane, I, 40; II, 35; III, 20; IV, 5.
In 4 murderers, I, o; II, 75, III, 25.
In 3 negroes, I, 33; II, 67.
So far as these 58 individuals are concerned, the most common combination, viz., left continuity and right separation, is decidedly the rule with the moral and educated, less frequent with the ignorant and unknown, the insane and negroes, and does not occur at all in the murderers. The only instance of the reverse combination (left separation and right continuity) is an insane Swiss woman. The only two known to be left‐handed presented the more frequent combination I.These statistics suggest many special queries and problems, some of which were briefly indicated. But the speaker wished this to be regarded as a preliminary communication and asked the coöperation of other members in the effort to obtain satisfactory records of larger numbers, particularly of brains of wellborn, moral and educated persons. For this purpose a blank form was outlined and will be sent upon application.
The influence of Fe‐group metals on the CVD of titanium carbide
Authors: Konyashin Igor Y. 
Published: May 2005

AbstractA number of experiments and computer simulations involving chemical vapor deposition (CVD) of TiC or TiN on various substrates containing Fe, Co or Ni allow the following mechanism of the influence of these metals on the CVD process to be assumed: These metals, being transferred from the substrate into the coating, evidently accelerate the decomposition of methane and enhance its reactivity at the substrate surface. Carburization of titanium, formed due to hydrogen reduction of TiCl4, which is a limiting stage of the TiC CVD, is activated in this way. The deposition rate, structure and morphology of the TiC coatings are affected by the presence of Fe, Co or Ni at the deposition zone, due to their catalytic effect on the process of methane activation and decomposition.
Absolute (calibrationless) chronoamperometric determination with a mercury hemispherical semimicroelectrode
Authors: Bustin Dušan , Mesároš Štefan , Rievaj Miroslav , Tomčík Peter 
Published: May 2005

AbstractAmperometric determination of electroactive species not requiring calibration described in this work is based on separation of linear and spherical parts of limiting diffusion current of a determined substance to the hemispherical Hg‐semimicroelectrode (radius 37.5 μm). Charges transfered by these two components of current during experiment are comparable for semimicroelectrodes and the determination error is acceptably low (< 10%) for concentration interval 50–500 μmol dm−3. The calibrationless amperometric determination was verified with cadmium and lead. A new way of calculating optimum value of electrode radius to minimize the determination error is also presented.
A simple electropolymerization method for the production of microarray electrodes
Authors: Imisides Mark D. , Wallace Gordon G. 
Published: May 2005

AbstractThe preparation of a polymer based microarray system is described. The technique utilizes electropolymerization to form a nonconductive polymeric layer on a conductive substrate. Provided appropriate electrochemical conditions are used, microarray behavior can be obtained for the resultant modified electrode substrate.
Determination of formation constants of metal complexes by potentiometric stripping analysis
Authors: Tutunji Maha F. 
Published: May 2005

AbstractA method based on the data obtained from complexometric titration followed by potentiometric stripping analysis is developed. Optimization of the experimental conditions, namely: choice of the proper oxidant, deposition potential, plating time, concentration, and pH, considerably reduced the errors contributed by kinetic dissociation. This method was applied to ethylenediaminetetraacetic acid (EDTA) titration with lead and gave a formation constant for Pb‐EDTA that agreed well with literature values. The method may be applied to the determination of formation constants of 1 : 1 complexes with Kf values about 1020. The feasibility of the metal ion depends mainly on the solubility of the metal in the mercury in addition to its reversible behavior at the thin mercury film electrode.
Highly sensitive detection of L‐lactate and pyruvate by amperometric flow‐injection analysis based on enzymatic substrate recycling and selective detection of hydrogen peroxide
Authors: Yao Toshio , Satomura Masahiro , Nakahara Tuketoshi 
Published: May 2005

AbstractThe poly(1,2‐diaminobenzene)film‐coated platinum electrode was used as an amperometric detector in a flow‐injection system with the lactate dehydrogenase/lactate oxidase coimmobilized reactor involving amplification by substrate recycling. Both L‐lactate and pyruvate are recycled enzymatically during their passage through the enzyme reactor in the presence of reduced nicotinamide adenine dinuceotide (NADH) and oxygen in the carrier stream. As a result, a large amount of hydrogen peroxide is generated in the enzyme reactor. The poly(1,2‐diaminobenzene)‐coated electrode could only selectively detect the hydrogen peroxide generated in the enzyme reactor, without an increase in the base‐line current owing to the direct oxidation of NADH, because the poly(1,2‐diaminobenzene) film effectively prevented NADH in the carrier stream from reaching the electrode surface and allowed only the hydrogen peroxide to penetrate into the polymerized film. In the present flow‐injection analysis (FIA) system, both L‐lactate and pyruvate were determined with a 400‐fold increase in sensitivity compared with the unamplified responses. The detection limit was 2 × 10−9 M (20 fmol) for 10 μL sample injection.
A conductometric detector for capillary separations
Authors: Müller D. , Jelínek I. , Opekar F. , Štulik K. 
Published: May 2005

AbstractA simple electrochemical cell has been constructed for conductometric detection in capillary electrophoresis or HPLC. A platinum ring electrode is chemically deposited at the capillary end and the other electrode, a platinum wire, is immersed, together with the capillary, in a vessel containing the running buffer or the mobile phase used. The cell has been tested on a model system and its operational parameters have been discussed. The measurement is very sensitive (a limit of determination of ca. 3 × 10−9 M for potassium ions) and the detector response is rapid, comparable with that of the UV photometric detector. The dynamic range is wide (at least five concentration decades) but is nonlinear at high concentrations.
Polarographic maxima revisited
Authors: Noufi Mouna , Yarnitzky Chaim , Ariel Magda 
Published: May 2005

AbstractThe relation between maxima (of the first kind) and drop lifetime‐potential (TE) curves was investigated by recording both the DC polarogram and the TE curve and comparing the latter to that obtained with the blank solution, under identical conditions. The advanced instrumentation for measuring drop life‐time allowed the detection of minute variations occurring in various regions of the applied potential range. Positive maxima were studied with CUII/ClO, CuII/Cl−, PbII/Cl−, FeIII/C2O and UO/C2O systems; negative maxima, with solutions of NiII, ZnII and PbII.Hypotheses explaining the variations in maximum shape and height and in drop lifetime, taking into account the nature of the electroactive species (mainly, the location of the reduction step vs. the pzc), or the supporting electrolyte concentration are submitted, including the differing behavior observed with positive and negative maxima.
An amperometric lactate sensor based on a NAD+‐analog and lactate dehydrogenase coimmobilized on reticulated vitreous carbon
Authors: Khayyami Masoud , Garcia Nuria Peña , Larsson Per‐Olof , Danielsson Bengt , Johansson Gillis 
Published: May 2005

AbstractA NAD+‐analog was coimmobilized with lactate dehydrogenase (LDH) on reticulated vitreous carbon (RVC) to give an amperometric lactate biosensor. Both LDH and the NAD+ ‐analog were bound covalently with carbodiimide to the surface of the porous RVC‐material. The electrode was operated in a FIA‐arrangement in the presence or absence of a soluble mediator. Meldola Blue. The stability was poor when the electrode was operated at +400 mV (vs. Ag/AgCl) in the absence of mediator but improved most significantly in the presence of 5 μM mediator, so that 65% of the original activity remained after 16 days. The amperometric currents were smaller with regeneration by mediator at −100 mV than with direct electrochemical oxidation at +400 mV, indicating that the additional steps slow down the reaction rate. Linear calibration plots were obtained from the detection limit, 1 μM, to 500 μM lactate with 5 μM mediator, reoxidized at −100 mV. The sample throughput was about 60 h−1.
Metal analysis in real matrices. Simultaneous voltammetric determination of copper and antimony in alloys
Authors: Locatelli Clinio 
Published: May 2005

AbstractThis work addresses the simultaneous determination of copper(II) and antimony(III) in real matrices by differential pulse (DPASV) and fundamental harmonic alternating current anodic stripping voltammetry (ACASV). The voltammetric measurements were carried out using as supporting electrolyte the same acidic mixture (nitric, hydrochloric and perchloric acids) used in the dissolution of the real matrices with proper dilution. The procedure of the sample preparation is thus reduced to one step hence avoiding errors from long and complex sample handlings prior to the instrumental measurement. The results were verified by the analysis of the standard reference materials NBS‐SRM 631 Spectrographic Zinc Spelter D‐2 and BCS 207/2 Gunmetal. The precision, expressed as relative standard deviation, and the accuracy, expressed as relative error, were, in all cases, less than 5%; the detection limit, for each element and in the experimental conditions employed, was around 10−7 M. The standard addition technique improved the resolution of the voltammetric method, even in the case of very high metal concentration ratios.
Rapid isoelectric focusing and detection of nanogram amounts of proteins from body tissues and fluids
Authors: Allen Robert C. 
Published: May 2005

AbstractPolyacrylamide gel isoelectric focusing was carried out using 250 μm thick gels backed with polyester films at voltage gradients up to 460 V/cm. Peltier cooling was employed with berrylium oxide heat transfer plates to achieve adequate cooling. Visualization of low protein concentrations was obtained by the use of a highly sensitive silver staining technique. Results indicated that over separating distances of 5.4 cm 150 to 200 bands should be resolved and that considerable differences between two commercial carrier ampholytes exist. Pharmalyte carrier ampholytes from Pharmacia have better continuity and conductance over the range of pH 3–10 but require much higher field strengths to achieve maximal separation than do LKB Ampholines over a similar pH range.
Microheterogeneity of serum myeloma immunoglobulins revealed by a technique of high resolution two‐dimensional electrophoresis
Authors: Latner Albert L. , Marshall Thomas , Gambie Moira 
Published: May 2005

AbstractA simplified technique of high resolution two‐dimensional electrophoresis has been used to investigate heterogeneity of human serum myeloma proteins. Three types of microheterogeneity have been detected. The heavy chains of IgA, IgM and IgD myeloma proteins demonstrate charge heterogeneity which is far less extensive following neuraminidase treatment and is therefore largely due to sialic acid. The underlying charge heterogeneity, which is apparently resistant to neuraminidase, resembles the charge heterogeneity demonstrated by the heavy chains of IgG myeloma proteins which show no response to neuraminidase treatment. The third type of microheterogeneity is most clearly demonstrated by the heavy chains of IgD myeloma proteins which exhibit heterogeneity with respect to small variations (∼︁3000) in molecular weight. This type of heterogeneity has also been observed, to a lesser extent, in the heavy chain of IgM and IgA myeloma proteins.
One‐ and two‐dimensional electrophoresis in micro‐slab gels
Authors: Poehling Hans‐Michael , Neurhoff Volker 
Published: May 2005

AbstractAll acrylamide slab gel electrophoresis widely used for various separation problems at the marcro‐level can be converted readily to micro‐versions. This is demonstrated in isoelectric focusing, homogeneous or gradient micro‐slab gels, and two‐dimensional separations. The different types of micro‐slab gel electrophoresis have the same resolving capability as the corresponding macro‐method, which is demonstrated with different biological samples. Enzyme staining after two‐dimension separations is also possible. The apparatus, preparation and handling of the different micro‐slab gels is described in full detail.
True and false glycoprotein microheterogeneity observed with lectin crossed affinoimmunoelectrophoresis of inter‐alpha‐trypsin‐inhibitor
Authors: Salier Jean‐Philippe , Faye Loîc , Vergaine Dominique , Martin Jean‐Pierre 
Published: May 2005

AbstractCrossed affinoimmunoelectrophoresis (CAIE) with free lectin in the first dimension was used to investigate sugar heterogeneity of inter‐α‐trypsin‐inhibitor (ITI) in normal human serum and after purification. Such a heterogeneity was assessed with Lens culinaris agglutinin and Concanavalin‐A, but not with wheat germ agglutinin. The use of a mixture of purified ITI and ITI‐free serum demonstrated that a distortion of the immunoprecipitation patterns for ITI in normal serum was observed with Con‐A and WGA and was due to presence of other glycoproteins. Thus, prior protein purification is sometimes required before obtaining a true pattern of glycoprotein microheterogeneity by lectin CAIE. Furthermore, loading a sugar specific for the lectin in the second dimension gel was shown to be necessary in order to observe all heterogeneous forms of the glycoprotein tested.
Two‐dimensional electrophoresis of membrane and cytosol proteins of mouse liver and brain
Authors: Klose Joachim , Feller Marianne 
Published: May 2005

AbstractMembrane proteins and cytosol proteins from organs (liver, brain) of inbred mice were separated by two‐dimensional electrophoresis (2DE). The 2DE technique revealed high resolution of complex protein solutions by staining the proteins. The 2DE patterns of membrane proteins showed about 660 protein spots (polypeptides) for both liver and brain. The protein patterns of the cytosols revealed about 800 polypeptides for the liver and about 680 for the brain. The membrane proteins and cytosol proteins of the 2DE patterns represented two protein populations specific for these two cell components. They matched in 7 % (liver) or 23 % (brain) of the total number of membrane protein spots. The matched spots represented dissociable membrane proteins rather than contamination of the isolated membrane fractions by cytosol proteins. Protein patterns of the same cell fraction but from the two different organs investigated contained more than 50 % organ‐unspecific polypeptides.Several conditions of our 2DE standard procedure were reinvestigated to test the usefulness for our technique of some methodical steps employed in 2DE by other authors. We found that many steps often used in sample preparations impaired rather than improved the 2DE pattern. In particular, addition of SDS to the protein sample resulted in a considerable loss of proteins during isoelectric foucing. The 2DE itself could be simplified by omitting several steps such as prefocusing, equilibration of focusing gels, forming gel gradients, autoradiography. This has some implications for the development of 2DE to a routine method.
A method for continuous preparative electrophoresis using a supporting medium
Authors: Lammel Bernd 
Published: May 2005

AbstractA method for continuous preparative electrophoresis is presented. It is based on the principle that a supporting medium, e.g. a polyacrylamide gel, is moved continuously relative to an electrical field. At one fixed point, the sample is applied to the gel. The charged particles migrate with different velocities in the supporting medium. Simultaneously, they are dragged along with the supporting medium. This procedure leads to a two‐dimensional separation of charged particles, which is necessary for a continuous operation of an electrophoresis apparatus. Three different designs of apparatuses, using this method, are presented in this paper. The operation of one construction was tested by separating three protein mixtures.
Two‐dimensional immunoelectrophoresis of rat serum apolipoproteins
Authors: Dolphin Peter J. 
Published: May 2005

AbstractA two‐dimensional crossed immunoelectrophoretic method for the determination of the specificity of antibodies raised against rat serum lipoproteins and apolipoproteins (Apo) is described. The method may also be used for the detection of as yet undesignated apoproteins, associated with the serum lipoprotein fractions, and exploits the superior resolving capacity of 7m urea 10% polyacrylamide gel electrophoresis for the first dimension separation and minimizes physical separation of polyacrylamide and agarose in the second dimension electrophoresis by use of low electroendosmotic flow agarose. The use of polyacrylamide instead of cellulose acetate in the first dimension permits the analysis of larger amounts of antigen protein, crossed imunoelectrophoresis of Apo E which binds to cellulose acetate, and the crossed immunoelectrophoresis of antigens previously focused to their isoelectric points in polyacrylamide gels containing ampholytes.