bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mikrofeine Polyolefin‐Pulver. 1. Mitt.: Über den einfluß des lösungsmittels, der konzentration der lösung und von nichtlöserzusätzen auf die pe‐pulvercharakteristik
Authors: Bischof C. , Herma H. , Gieseke R. , Schneider J. , Küchler H. 
Published: May 2005

AbstractDie Bedingungen für die Herstellung mikrofeiner LDPE‐Pulver aus konzentrierten PE‐Lösungen werden untersucht. Der Einfluß wesentlicher Parameter wie Molmasse, Lösungsmittel, PE‐Konzentration, Abkühlgeschwindigkeit und Zusatz von Nichtlösern auf die Teilchenbildung und Pulvercharakteristik werden aufgezeigt. Die Möglichkeiten, sowohl die Ausbeute an Feinstkorn < 32 μ als auch die Teilchengrößenverteilung durch Variation der Versuchsparameter zu beeinflussen, werden diskutiert.
Texturuntersuchungen an Polyvinylidenfluorid (PVDF). Teil II. Untersuchungen zum Orientierungszustand einachsig gereckter PVDF‐folien der Modifikation II in Abhängigkeit von der Einwirkung eines elektrischen Feldes
Authors: Geiss D. , Ruscher Ch. 
Published: May 2005

AbstractDer Orientierungszustand in einachsig gereckten PVDF‐Folien, deren geordnete Bereiche überwiegend aus der monoklinen Modifikation II bestehen, entspricht einem gemischten Texturtyp. Einer vorherrschenden Fasertextur ist ein uniplanarer Texturanteil überlagert. Dieser ist als Mehrfachtextur mit einer gleichzeitigen bevorzugten Ausrichtung der Netzebene (110) und (020) parallel zur Folienoberfläche ausgebildet. Als Folge einer elektrischen Feldeinwirkung werden sowohl Änderungen der kristallinen Struktur der geordneten Bereiche der Modifikation II als auch Änderungen des Orientierungszustandes nachgewiesen.
Head to head polymers. XXIX. A new synthetic route to poly(1,1‐dimethylpropane)
Authors: Malanga M. , Vogl O. 
Published: May 2005

AbstractPoly(1,1‐dimethylpropane) was synthesized by Wurtz coupling polymerization. The polymer was of moderate molecular weight, about 50% crystalline, had a melting temperature of 87°C and a glass transition temperature of −17°C. The polymer was essentially the same material as that obtained by cationic hydride transfer polymerization of 3‐methylbutene‐1 at very low temperatures, or by cationic ring opening polymerization of 1,1‐dimethylcyclopropane. Poly(1,1‐dimethylpropane) obtained by the Wurtz reaction was obtained in only low yield; a substantial part of the total reaction product was 1,1‐dimethylcyclopropane.
Zur Feinstruktur von Ethylen‐Vinylacetat‐Copolymeren
Authors: Beyer D. , Lautner W. , Behrens H. 
Published: May 2005

AbstractWährend der Copolymerisation von Ethylen mit Vinylacetat werden Vinylacetat‐Einheiten in die Polyethylen‐Ketten eingebaut. Infolgedessen wird die Gitterzelle der Polyethylenstruktur aufgeweitet. Mit Hilfe der Röntgenweitwinkelstreuung wurde die Vergrößerung der Gitterparameter bestimmt. Auf der Grundlage dieser Veränderung der Gitterparameter wird ein Strukturmodell für Ethylen‐Vinylacetat‐Copolymere vorgeschlagen.
Synthesis of a zeolite film on a mercury surface
Authors: Kiyozumi Yoshimichi , Mizukami Fujio , Maeda Kazuyuki , Toba Makoto , Niwa Shu‐ichi 
Published: May 2005

Polycrystalline zeolite films–of great importance in catalysis, separation, and sensing—can be grown on various substrates, but in most cases there are problems in detaching the films. It is shown that a mercury surface accelerates the nucleation and crystallization of MFI‐type zeolites and that the surface of the film against the mercury (left in Figure) is smoother than that on the solution side (right in Figure). magnified image
The general theory of assembly and its application to the production of moulds and other tools
Authors: Čatić I. , Zelić B. , Kokolek R. 
Published: May 2005

AbstractThe basis of the General Theory of Assembly (GTA) and its application to the production of moulds and other tools is described. The terms of accuracy and precision are defined. Existing methods of calculating tolerances are explained and their significance summarised. The results of a production run on a small series of homogeneous components are presented. The assembly of two‐ and multi‐component fits is explained by examples. Average improvements in the tolerances of fits from 2 to 8.3 times are presented. Finally, an attempt is made to answer the question why GTA has not been used more in toolmaking in spite of its simplicity and applicability without any additional investment in equipment.
Rethinking the injection molding process with thermosets and rubber
Authors: Buschhaus F. , Benfer W. 
Published: May 2005

AbstractTo optimize the processing, a process model has to be developed. To be able to use a model of this kind, we must also have material data (thermodynamic material data, viscosity, processing time) and must install sensors on the machine and in the mould.The flow properties of thermosets/elastomers under processing conditions is determined not only by pressure, temperature and throughput, but also to a considerable extent by the boundary conditions.At a given throughput, it is possible to calculate the pressure loss for passing through a runner system by dividing up the flow into a plug flow and a boundary shear flow. This takes into account the pronounced temperature profile, which brings about a low‐viscosity outer layer and a high‐viscosity core.With thermosets/elastomers, the compounding process influences the flow properties to a considerable extent. This means that the continuous monitoring of the material state must be included in the process control. This monitoring can be carried out during the mould filling period. Since the mould is filled over a wide area at constant velocity, the gate can be regarded as a “rheometer” and the pressure loss between two pressure sensors installed in the gate used as a measure of the viscosity.Starting from this measurement of the flow properties, moulding properties such as weight and surface texture are influenced in the compression phase. The form of the pressure build‐up in the compression phase affects the flash formation; this pressure buildup should, in fact, be carried out in such a way that the pressure maximum is not reached until the outer layers have passed through their viscosity minimum.After the compression, the moulding is crosslinked in the crosslinking phase far enough for it to be demoulded or for the moulding properties, which are connected with a given crosslinking profile over the cross‐section, are reached.
The quinlan decision: Problems and legislative alternatives
Authors: Beresford H. Richard 
Published: May 2005

AbstractIn the Quinlan decision, a state supreme court authorized remval of a respirator from a person in a chronic vegetative state provided that the attending physicians and an “ethics committee” agreed there was no reasonable possibility of her regaining cognition or sapience. While the decision involves an unusual factual situation and poses some troublesome technical and doctrinal problems, it underscores the need for formal legal standards to guide physicians and families of severely brain‐damaged patients.Legislation seems preferable to a series of court decisions. The legislative process allows the public to express views on controversial ethical and religious questions. It also permits extensive deliberations about medical and scientific data relating to brain damage and its prognosis. Legislative alternatives include expanding the concept of brain death, redefining homicide, allocating to physicians and families legally unreviewable discretion to decide on levels of care, mandating procedures for implementing a desired reduction of care, and approving the use of a “living will” as a means of requiring physicians to withdraw or withhold treatment.
Sarcoidosis, galactorrhea, and amenorrhea: 2 Autopsy cases, 1 with chiari‐frommel syndrome
Authors: Brust John C. M. , Rhee Richard S. , Plank Charles R. , Newmark Michael , Felton Charles P. , Lewis Linda D. 
Published: May 2005

AbstractTwo women with amenorrhea and galactorrhea, 1 with Chiari‐Frommel syndrome, died of cerebral sarcoidosis. At autopsy in both cases, sarcoid granulomas were numerous in the hypothalamus, but the pituitary appeared normal and did not contain increased prolactin as determined by immunoperoxidase technique. These are the first autopsy reports of sarcoidosis with galactorrhea and of Chiari‐Frommel syndrome in the absence of pituitary adenoma.
Recovery of cognition after prolonged vegetative state
Authors: Rosenberg Gary A. , Johnson Stephen F. , Brenner Richard P. 
Published: May 2005

AbstractA 43‐year‐old man remained in a vegetative state for one and one‐half years after resuscitation from cardiac arrest. During the vegetative period neurological examinations provided little indication of recovery. Initially, his EEG showed activity of delta and theta frequencies. After eighteen months intellectual functions partially recoverd; his verbal WAIS score is now 100, although he remains severely physically disabled. The usual prognostic criteria did not predict the cognitive outcome in this patient with prolonged medical coma.
Subcellular distribution of rat pituitary homogenates by poly(ethylene glycol)‐dextran countercurrent partitioning
Authors: De Marco Luiz , Morris Wesley B. , Mashiter Keith , Peters Timothy J. 
Published: May 2005

AbstractRat pituitary homogenates were subjected to two phase countercurrent partition in a poly(ethylene glycol)–dextran mixture using a simple apparatus with enhanced gravity to facilitate the phase separations. Assay of the fractions for organelle marker enzymes and prolactin after 17 transfers showed similar distributions for endoplasmic reticulum, lysosomes, prolactin granules and plasma membrane at the lowest dextran concentrations. Increasing the dextran concentrations had a differential effect on the various organelles. Excellent resolution of endoplasmic reticulum from the other organelles was obtained and marked organelle heterogeneity was demonstrated. Two‐phase countercurrent partition thus offers an alternative approach to the subcellular fractionation of pituitary homogenates and should prove useful in separating endoplasmic reticulum from plasma membrane and other cell components.
A rapid and reliable method for extraction and assay of tricyclic antidepressant drugs in serum or plasma
Authors: Roberts G. M. , Hann C. S. 
Published: May 2005

AbstractBecause of their narrow therapeutic ranges and differing patient tolerances, the monitoring of tricyclic antidepressants (TADs) commonly prescribed for control of endogenous depression is highly desirable for the satisfactory treatment of patients. The majority of methods for analysis of TADs require multiple extractions from plasma with organic solvents, accompanied by obligatory centrifugation steps. We describe a simple procedure for the rapid extraction of serum TADs, with high recovery of the analyte drugs. It involves sample preparation using Analytichem ‘BOND‐ELUT’ C‐2 reverse phase columns, and analysis by gas chromatography using a nitrogen‐phosphorus detector. The method offers a quick, inexpensive and low‐maintenance assay which is applicable to all the common tricyclic class drugs.
Paper chromatography of urinary amino acids. A 30 year survey of dietary influences on the normal pattern, and patients' results
Authors: Mattingley Joan M. 
Published: May 2005

AbstractIn the clinical laboratory, paper chromatography is still the most useful, simple, inexpensive procedure for initial identification of abnormalities of amino acid excretion. The results of its use for more than 8000 paediatric and adult renal patients is surveyed. Nonspecific generalized aminoaciduria was the most frequent abnormality found, comprising some 70% of abnormal results, with cystine‐lysinuria the next most common. The identification of the abnormal excretory pattern of amino acids as distinct from the normal was complicated by the effects of the New Zealand diet. In particular, valine, citrulline, hydroxyproline and glutamic acid are found in considerable amounts as part of the normal pattern. Their dietary origin is discussed. Varying mixtures of monosaccharides and disaccharides occurred in association with a range of amino acid patterns.
Simple determination of forphenicinol in human plasma and erythrocytes by HPLC with native fluorescence detection
Authors: Kai Masaaki , Tamura Kazuhiko , Ohno Masahiro , Ohkura Yosuke 
Published: May 2005

AbstractA high performance liquid chromatographic method is described for monitoring forphenicinol, a possible therapeutic drug for cancer and muscular dystrophy, in human plasma and erythrocytes. Forphenicinol in the deproteinized samples was separated from interfering biogenic substances on an aminopropyl‐bonded silica (Unicil NH2) column within 10 minutes with isocratic elution, and determined with fluorescence detection. The detection limits for forphenicinol in plasma and erythrocytes are 65 pmol (12.8 ng)/ml and 160 pmol (31.5 ng)/ml, respectively, corresponding to 2 pmol each in a 100 μl injection volume. The method is very simple, and sensitive enough to permit the quantification of forphenicinol in the blood samples from man dosed with forphenicinol.
Opioid peptides in the cerebrospinal fluid of Alzheimer patients
Authors: Muhlbauer Michael , Metcalf James C. , Robertson James T. , Fridland Genevieve , Desiderio Dominic M. 
Published: May 2005

AbstractEndogenous opioid receptoractive peptides in the cerebrospinal fluid (CSF) of human controls and in those patients diagnosed as having senile dementia of the Alzheimer's type (SDAT) are measured with a radioreceptorassay following HPLC separation. [3H]Etorphine is the ligand used to detect in the HPLC fractions the presence of those endogenous peptides that preferentially interact with several opioid receptors. The RRA uses a receptor‐rich P2 fraction extracted from a canine limbic system. The total opioid peptide content found in the HPLC fractions 6–20 (to avoid salts in fractions 1–5) of SDAT CSF (383 ± 187 pmol ME‐equivalents per ml CSF) is significantly higher than the corresponding total from patients with no known neurological disorders (89.1 ± 46.3 pmol ME‐equivalents per ml).
HPLC of trazodone in serum after microscale protein precipitation
Authors: Lam Stanley , Boselli Lucia 
Published: May 2005

AbstractTrazodone, an anti‐depressant medication, is found in serum in the 500–1000 ng/mL range in patients taking therapeutic doses. Because of this relatively high concentration, it has been possible to devise an HPLC assay system using the rapid, convenient microscale procedure described previously by Lam et al. (Clin. Chem. 26, 963 1980) to prepare the sample for chromatography. To 0.1 mL serum were added 0.1 mL acetonitrile and 10 μL of 10% zinc sulfate in water. The mixture was centrifuged and 50 μL of the clear supernatant was injected into a reversed‐phase column which was eluted with 65% 0.05 M potassium phosphate−35% acetonitrile, with detection by ultraviolet absorbance at 210 nm. The trazodone elutes in 6 min, clearly resolved from endogenous interferences. The recovery of trazodone added to serum was better than 90%. Peak height was proportional to concentrations in the serum sample from 125 ng/mL to 3000 ng/mL.
Reduction of quinones with zinc metal in the presence of zinc ions: Application of post‐column reactor for the fluorometric detection of vitamin K compounds
Authors: Haroon Y. , Bacon D. S. , Sadowski J. A. 
Published: May 2005

AbstractA simple and effective chemical method has been developed for quantitatively reducing quinones, which is based on their reaction with zinc metal and zinc ions. Comparison of this method with conventional electrochemical reduction revealed the chemical method to be considerably superior. The reduction of quinones to their corresponding hydroquinones was verified by ultraviolet spectrophotometry. The reduction methodology has been applied to derivatize phylloquinone and its metabolite, namely phylloquinone 2,3‐epoxide, ‘on‐line’, with subsequent fluorometric detection of the generated hydroquinones.
Detection and identification of three thioether conjugates of 2‐hydroxyacetanilide by liquid chromatography/electrochemistry
Authors: Rottero Anthony E. , Kissinger Peter 
Published: May 2005

AbstractThe three 2‐mercaptoethanol (ME) thioether conjugates of 2‐hydroxyacetanilide (2HAA) are detected and identified using liquid chromatography/electrochemistry (LC/EC). The conjugates are produced either by incubations of 2HAA with liver microsomes in the presence of NADPH and ME or by chemically oxidizing a solution of 2HAA and allowing it to react with ME. Identification of the three isomers is based on retention time and comparison of the electrochemical behavior of model compounds.Production of the three isomers by microsomal protein occurs only in the presence of NADPH and shows that 2HAA proceeds through a cytochrome P‐450 mediated pathway to a reactive intermediate similar to acetaminophen, possibly N‐acetyl‐o‐quinoneimine.The relative percentages of each isomer produced were calculated as the percentage of the total peak areas of the isomers. Compound A (2HAA‐5‐ME) is produced in 53.7% and 24.6%, compound B (2HAA‐4‐ME) is produced in 16.2% and 70.3% and compound C (2HAA‐3‐ME) is produced in 30.1% and 5.1% by microsomal incubations and chemical oxidation respectively.
Determination of 3, 4‐dihydroxyphenylglycol (DHPG) by HPLC with coulometric detection, and correlation with 3‐methoxy‐4‐hydroxyphenylglycol (MHPG) in human plasma
Authors: Karege F. , Gaillard J.‐M. , Tissot R. , Azorin J.‐M. , Valli M. 
Published: May 2005

AbstractA method for determining plasma 3,4‐dihydroxyphenylethyleneglycol (DHPG), a central noradrenaline (NA) metabolite, is described. The method used HPLC with dual coulometric detection set in screen mode of operation. The isolation of DHPG and related catecholamines (noradrenaline, dopamine and dihydroxybenzylamine) was performed on acid washed alumina extracted with 0.2 M HClO4 containing EDTA (0.2%), and reduced glutathione as stabilizer. A reversed phase column with an eluting system containing 0.025 M citric acid‐sodium hydrogen phosphate buffer in the ratio 3:2 (v:v) and 5% methanol was used. The experimental results of plasma DHPG levels compared favourably with the results from the literature, and a positively significant correlation with plasma MHPG was found. This method could be used as an alternative in central NA assessment.
Rapid sample preparation methods for analysis of residues of sulfamethazine and its N4‐acetyl and desamino metabolites in swine tissue by HPLC
Authors: Haagsma N. , Pluijmakers H. G. J. M. , Aerts M. M. L. , Beek W. M. J. 
Published: May 2005

AbstractRapid sample preparation methods for the determination of sulfamethazine (SMZ) and its N4‐acetyl and desamino metabolites in swine tissues at the 0.1 mg kg−1 level are presented. The methods use sonication‐aided extraction with dichloromethane. For SMZ and N4‐acetyl SMZ analysis extracts are cleaned up and concentrated on a silica disposable column followed by HPLC on a CP™ Spher C8 column using acetonitrile‐sodium acetate buffer as the mobile phase. For desamino‐SMZ analysis the extract was cleaned up and concentrated on a Florisil disposable column, followed by HPLC on a Nucleosil 5‐CN column after formation of an ion‐pair complex with 1‐heptanesulfonic acid. For desamino SMZ peak identification by diode‐array UV/VIS detection is also described. Mean recoveries from spiked tissue samples were about 87% (muscle) and 76% (kidney) for SMZ and N4‐acetyl SMZ and about 70% for desamino SMZ.
HPLC receptorassay of opioid peptides in the cerebrospinal fluid of lower back pain patients
Authors: Desiderio Dominic M. , Onishi Hiroshi , Fridland Genevieve , Wood George , Pagidipati Devaiah 
Published: May 2005

AbstractTotal opioid peptide receptoractivity in human cerebrospinal fluid is measured in patients who are experiencing lower back pain. Desalted CSF is eluted from a C18 Sep‐Pak and is subjected to a radioreceptorassay (RRA) that employs tritiated etorphin, which is aligand that is effectively displaced by opioids from several different types of opioid receptors. Three clinical groups have significantly different endogenous levels of 2.4, 4.5, and 6.4 pmol of methionine enkephalin‐equivalents per mL CSF. Those three levels indicate that more opioid activity is correlated with the amount of drug to relieve the patient's perception of pain. When the total opioid content exceeds an empirical threshold, the sample is further fractionated with gradient reversed phase HPLC, and the opioid receptoractivity in each HPLC fraction is measured to determine the characteristics pattern of those receptoractive opioid peptides present in that patient's CSF. Different HPLC RRA patterns are found for different clinical categories. A possible interpretation of these two different sets of data‐is that a lesion exists in one or several of the opioid peptidergic systems (metabolism, receptors) in this particular patient population.
HPLC determination of ferrochelatase activity in human liver
Authors: Roberts R. G. 
Published: May 2005

AbstractA method utilizing HPLC to estimate ferrochelatase activity in human liver cells is presented. A partially purified homogenate of liver cells is incubated with mesoporphyrin IX and cobalt(II) ion. The ferrochelatase in the homogenate incorporates the cobalt(II) ion into the mesoporphyrin. After a fixed time (90 min) the porphyrins are extracted into an ethyl acetate‐acetic acid mixture. The porphyrins are then separated using reversed phase HPLC with a mobile phase of methanol‐acetonitrile‐phosphate buffer pH 3.0 (200:60:30 v/v). The enzyme activity is estimated by measuring the rate of utilization of mesoporphyrin. The optimum pH and substrate concentration for the reaction have been determined.
Separation and quantitation of plasma free fatty acids as phenacyl esters by HPLC
Authors: Uji Yoshinori , Noma Akio , Shiraki Masataka , Maeda Masako , Tsuji Akio , Okabc Hiroaki 
Published: May 2005

AbstractWe have developed a rapid method for the separation of plasma free fatty acids as their phenacyl esters by high‐performance liquid chromatography (HPLC) using a reversed‐phase (C18) column. The derivatives of series of both saturated and unsaturated fatty acids (C12:0C22:6) are simultaneously separated within 45 min and detected with ultraviolet at 241 nm. The limit of detection of fatty acids was approximately 0.5 nmol in 20 μL injected volume of extracts, and the coefficient of variation of the present method did not exceed 3.0%. Comparison of the results of the present HPLC method with those of gas chromatography, gave very good correlations for all fatty acids in human plasma.