bluuebunny/crossref_metadata_2025_split huggingface dataset:
Untersuchungen zur anionischen Copolymerisation von Acrylnitril mit Acrylaten und Methylmethacrylat in Dimethylformamid
Authors: Berger W. , Morgenstern U. , Adler H.‐J. , Erussalimsky B. L. 
Published: May 2005

AbstractDie anionische copolymerisation von Acrylnitril mit Acrylaten und Methylmethacrylat, initiiert durch Lithium‐tertbutoxid in Dimethylformamid, wurde im Temperaturbereich −30°C und +10°C untersucht. Aus dem Einbauverhalten der Ester, der chemischen Uneinheitlichkeit und der Struktur der Copolymerisate werden die nach dem Modell von Mayo und Lewis berechneten Copolymerisationsparameter hinsichtlich ihrer Gültigkeit für diesen anionischen Prozeß überprüft.
Ethylen‐Polymerisation mit trägerfixierten Organometallverbindungen. II. Polymerisationskinetik und Einfluß von Wasserstoff
Authors: Sommer H. , Giesemann J. , Ulbricht J. 
Published: May 2005

AbstractDie Polymerisation des Ethylens wurde mit Trägerkatalysatoren, hergestellt aus γ‐Aluminiumoxid und Tetrabenzylzirkonium, kinetisch untersucht und die Reaktionsordnung bestimmt. In Abhängigkeit von der Zusammensetzung der metallorganischen Oberflächenverbindungen der Katalysatoren wurden unterschiedliche Polymerisationsgeschwindigkeiten gefunden. Während der Polymerisation werden die Polymerisationsaktiven Zentren allmählich gebildet. Zusatz von Wasserstoff vermindert die Polymerisationsgeschwindigkeit und die Molmassen der gebildeten Polymere. In diesem Fall liegen die aktiven Zentren bereits bei Reaktionsbeginn vor. Durch Vorbehandlung der Katalysatoren mit Ethylen oder Wasserstoff werden Benzylgruppen von den fixierten Zirkoniumverbindungen abgespalten.
German Materials Science: A self‐portrait
Authors: Gregory Peter 
Published: May 2005

AbstractAn influential and refreshingly frank report on the state of health of non‐university materials research in Germany has recently been published. National Research Centers, Max Planck Institutes, and Fraunhofer Institutes are among the organizations covered. Recommendations are made on the basis of materials type, and on the performances of the individual institutes. The conclusions of this self‐portrait, painted by representatives of the organizations themselves along with participants from the universities, industry, and state, will provide food for thought for both German materials scientists and those in other European countries concerned with the future development of this crucial economic sector.
Mass‐sensitive detection of solvent vapors: Predicting sensor effects
Authors: Dickert Franz L. , Stathopulos Helen , Reif Martin 
Published: May 2005

An understanding of analyte–coating interactions is needed in order to be able to predict the sensitivity and selectivity of coating materials considered for use in mass‐sensitive devices such as the quartz microbalance. Models are reviewed for the sensor response based on solubility parameters and calculated energies for functionalized coatings and supramolecular cavities (e.g., the substituted tetraazaparacyclophane shown in the Figure). magnified image
Langmuir–Blodgett films of a benzothiazolium dye containing a crown ether ring
Authors: Lednev Igor K. , Petty Micael C. 
Published: May 2005

AbstractThe structure of Langmuir–Blodget (LB) films built up from a novel benzothiazolium steryl dye containing a 1, 10‐dithia‐18‐crown‐6 ether group has been investigated using ellipsometry and polarised absorption spectroscopy. The Y‐type deposition results in a uniaxial film with a thickness of 2.18 ± 0.08 nm per monolayer and an index of refraction of 1.57 ± 0.03. the chromophore parts of the moelcule exhibit an in‐Plane orientation. The influence of mercury vapouron the LB films has been investigated using the technique of surface plasmon resonance.
Subacute sensory neuropathy: A remote effect of carcinoma
Authors: Horwich Mark S. , Cho Lucy , Porro Robert S. , Posner Jerome B. 
Published: May 2005

AbstractSeven patients with subacute sensory neuropathy are described and the findings in 29 previously reported patients are reviewed. The presence of this characteristic neurological disorder strongly suggests an accompanying neoplasm. Five of 7 patients had cancer, and 4 died. Autopsy was performed on 3, and pathological analysis revealed inflammation and degeneration of dorsal root ganglia and degeneration of posterior roots and posterior columns of the spinal cord. The dorsal root ganglion was biopsied in 4 patients and showed similar inflammatory lesions. Electron microscopical studies showed inflammation and neuronal degneration. No viral particles were seen. Viral cultures of the biopsied ganglia from 4 patients were negative. Antineuronal antibodies were not detected in 2 patients. The cause of this syndrome is unknown, and no treatment has been successful.
Periodic lateralized epileptiform discharges (PLEDS) and nystagmus retractorius
Authors: Young G. Bryan , Brown John D. , Bolton Charles F. , Sibbald William M. 
Published: May 2005

AbstractA 57‐year‐old diabetic woman presented with focal right‐sided seizures and hyperglycemia. She later showed periodic lateralized epileptiform discharges (PLEDs), originating in the left hemisphere, which were temporally associated with nystagmus retractorius. It appears that the left hemisphere epileptiform activity diffusely excited brainstem structures via polysynaptic pathways to produce the nystagmus.
Fisher's syndrome: A pharmacological study of the pupils
Authors: Okajima Toru , Imamura Shigehiro , Kawasaki Shoichiro , Ideta Toru , Tokuomi Haruhiko 
Published: May 2005

AbstractA pharmacological study was performed in the involved pupils to demonstrate the site of lesion in a patient with Fisher's syndrome who showed marked ptosis, complete external ophthalmoplegia, pupillary involvement with anisocoria, facial paresis, ataxia, areflexia, and albuminocytological dissociation in the cerebrospinal fluid. The instillation of 2.5% methacholine produced mild constriction of one pupil. This response was not detectable in the recovery stage. The instillation of 1.25% l‐epinephrine produced marked bilateral dilation of the pupils, in both the early and recovery stages. Instillation of 5% tyramine produced pupillary dilation as in the normal pupil. The response to 5% cocaine, tested only in the recovery stage, was weak in one pupil.These results imply that the pupillary involvement was due to peripheral involvement of the sympathetic and parasympathetic nervous systems. The lesion in the sympathetic nervous system was preganglionic, but in the parasympathetic nervous system the precise localization could not be determined.
L‐dopa effects on H‐reflex recovery in Parkinson's disease
Authors: Sax Daniel S. , Johnson Timothy L. , Feldman Robert G. 
Published: May 2005

AbstractConditioning of Hoffman's reflex in 7 normal and 7 parkinsonian subjects before and after L‐dopa therapy was tested using standard methods. Features of the raw data, including timing, duration, and magnitude of facilitation, were estimated optimally with nonlinear least‐squares for each test sequence on each subject. For each parkinsonian subject there was a consistent trend with treatment for several features to return to the average features of the normal group; to varying degrees, clinical reduction in bradykinesia and rigidity was also observed in all cases. These results are in general agreement with similar previous studies reported by other investigators but offer stronger statistical evidence and differ in certain finer details.
Paraparesis after renal transplantation
Authors: Jablecki Charles K. , Aguilo Juan J. , Piepgras David G. , Zincke Horst , Goldstein Norman P. 
Published: May 2005

AbstractA diabetic patient suffered paraparesis immediately after renal transplantation. Distal spinal cord infarction was diagnosed clinically. The infarction was probably caused by interruption of blood flow through the branches of the right internal iliac artery to the spinal cord when the vessel was divided for anastomosis to the transplanted kidney. This case report emphasizes the potential importance of the blood supply to the distal spinal cord derived from branches of the aorta below its bifurcation.
Chronic hexosaminidase A and B deficiency
Authors: Goldie William D. , Holtzman David , Suzuki Kunihiko 
Published: May 2005

AbstractThe leukocytes and fibroblasts from a mildly retarded 10‐year‐old girl who had a slowly progressive motor dysfunction showed absence of hexosaminidase A and B activities. Leukocytes from her asymptomatic mother and sister contained half the normal levels of both enzymes. This child is the second patient reported with a chronic form of hexosaminidase A and B deficiency, an enzyme deficiency previously described only in infants with rapidly progressive psychomotor deterioration (Sandhoff's disease).
Determination of serum catecholamine metabolites in neuroblastoma by high performance liquid chromatography with electrochemical detection
Authors: Tang Qin‐Mei , Xu Xiu‐Rong , Shi Ying‐Qiang , Jin Bai‐Xiang 
Published: May 2005

AbstractA method for determining serum catecholamine metabolites such as vanillylmandelic acid (VMA), 3‐methoxy‐4‐hydroxyphenyl glycol (MHPG) and homovanillic acid (HVA) in neuroblastoma by using high performance liquid chromatography and electrochemical detector is described. The separation of catecholamine metabolites was performed on a reverse phase column with an eluting system containing citric acid‐potassium hydrogen phosphate buffer and methanol as the organic modifier. The experimental results showed that VMA and HVA levels in the serum of neuroblastoma patients were 15–30 times higher than that of the normal control group. The same phenomenon also occurred in patients with stage II neuroblastoma. Serum VMA, MHPG and HVA levels reduced to normal in patients suffering from neuroblastoma after surgery. Serum catecholamine metabolites analysed by using HPLC/ECD is more simple, sensitive and reliable than that by usual urine assay and might be used for the diagnosis of neuroblastoma even in early stage.
The determination of nivacortol in plasma using HPLC
Authors: Honour J. W. , Sudan H. L. , Lovell G. 
Published: May 2005

AbstractA high performance liquid chromatographic method with ultraviolet detection was developed for the determination of nivacortol (WIN 27914) in biological samples. The drug was isolated from human plasma by using a solid‐phase extraction and eluted with ethanol. The solvent was evaporated and the residue dissolved in the chromatographic eluent. The sample was subjected to chromatography on a C8 silica column and eluted with a gradient of acetonitrile in 0.1 M sodium acetate buffer, pH 6.5. A single concentration of a structural analogue (WIN 31338) was used as internal standard for the quantitative determination of the analyte. The plasma concentrations were below that needed to suppress ACTH secretion by pituitary cells in culture and did not suppress plasma ACTH in Nelson's syndrome.
HPLC electrochemical fluorometric detection of amino acids including tryptophan using 4‐fluoro‐7‐nitrobenzo‐2‐oxa‐1, 3‐diazole
Authors: Watanabe Noriyuki , Toyo'oka Toshimasa , Imai Kazuhiro 
Published: May 2005

AbstractIt has been shown that by electrochemical oxidation 7‐nitrobenzo‐2‐oxa‐1,3‐diazole‐tryptochan (NBD‐T) is converted to fluorophores having the same emission and excitation spectra as those for other NBD‐amino acids, NBD‐dioxindolylalanine was tentatively assumed to be a main electrochemical oxidation product of NBD‐tryptophan. A coulochemical cell placed between an analytical column and a fluorometer showed no detrimental effect on the separation of NBD‐amino acids by reversed phase HPLC. Highly sensitive fluorescence detection was achieved for amino and imino acids at 10–100 fmol levels. The detection limit for tryptophan was 50 fmol.
Liquid chromatographic analysis of metoclopramide with fluorescence detection in cirrhotic patients
Authors: Albani Fiorenzo , Riva Roberto , Contin Manuela , Baruzzi Agostino 
Published: May 2005

AbstractMetoclopramide extracted from plasma and urine has been analysed using reversed phase HPLC with acetic acid/acetonitrile/triethylamine as eluent and fluorescence detection. This method exploits the natural fluorescence of metoclopramide for its detection in patients on multiple drug therapies.
Improved HPLC determination of urinary neopterin
Authors: Dewitte J. D. , Berthou F. , Dreano Y. , Floch H. H. 
Published: May 2005

AbstractIn order to improve the urinary neopterin measurement, the reversed‐phase HPLC method has been reevaluated. The parameters which influence the chromatographic behavior of 12 pteridines were studied: nature of buffer, pH,ionic strength, addition of organic modifier to the mobile phase. Accordingly, an isocratic HPLC method is described which offers a good compromise between specificity and analysis time. This method is well‐suited to automation in routine clinical laboratory use. Using this HPLC method, urinary neopterin related to creatinine was determined in lung diseases (neoplasm, sarcoïdosis and bronchial asthma) and in kidney allografts. This method was shown to be useful in the diagnosis and in the monitoring of treatment of rejection episodes.
Determination of Δ1‐tetrahydrocannabinol in human fat biopsies from marihuana users by gas chromatography–mass spectrometry
Authors: Johansson Eva , Norén Koidu , Sjövall Jan , Halldin Magnus M. 
Published: May 2005

AbstractA gas chromatographic–mass spectrometric (GC/MS) method for analysis of Δ1‐tetrahydrocannabinol (Δ1‐THC) in human fat samples is described. The fat sample, obtained from heavy marihuana users 1 week before and 4 weeks after smoking, is homogenized in hexane + 2‐propanol, centrifuged, and the supernatant mixed with Lipidex 5000. The solvent is evaporated and the dried gel is packed in a glass column. Δ1 ‐THC is eluted from the column with methanol + water + acetic acid, diluted with water and the eluent is passed through a bed of Octadecylsilanebonded silica. After washing and drying, the retained Δ1‐THC is eluted with hexane, derivatized with N‐methyl‐N‐(t‐butyl‐dimethysilyl)trifluoroacetamide (MTBSTFA) and finally purified by HPLC on an Octadecyl SI 100 column in methanol. The amount of Δ1‐THC is determined by GC/MS, using selected ion monitoring, and a deuterated internal standard. The recovery of Δ1‐THC is about 80%, and the concentration of Δ1‐THC in the fat samples analysed ranged between 0.4 and 193 ng/g wet tissue.
Simultaneous measurement of ethosuximide and phenobarbital in brain tissue, serum and urine by HPLC
Authors: Galan‐Valiente Josefa , Soto‐Otero Ramon , Sierra‐Marcuño German 
Published: May 2005

AbstractA simple rapid method for simultaneous ethosuximide and phenobarbital assay in brain tissue, serum and urine has been developed. Extraction of samples from brain tissue and serum were performed with dichloromethane at low pH in the presence of an excess of ammonium sulfate. Glucuronide conjugates in urine samples were hydrolyzed by enzymatic cleavage with β‐glucuronidase and then extracted with dichloromethane. The extracts were analyzed using a Spherisorb 5 ODS column and a mixture of acetonitrile, methanol and phosphate buffer (21: 24: 55, v/v) as eluent. No interference was encountered and the method is both precise and reproducible.
Quantification of midodrine and its active metabolite in plasma using a high performance liquid chromatography column switching technique
Authors: Posch Werner , Lindner Wolfgang 
Published: May 2005

AbstractAn automated column‐switching HPLC system is described for the simultaneous determination of midodrine, an alpha‐adrenergic stimulating drug, and its active metabolite, ST‐1059. Serum or plasma (850 μ L) is directly injected onto a RP 18 (30 μm particle size) pre‐column (9 × 4 mm ID) which acts as an on‐line liquid‐solid extractor and analyte enrichment system. The injection is followed by washing steps. The fraction containing the analytes is transferred onto an analytical RP18 column via step gradient elution where the final analysis is performed. Fluorescence detection is used (λex 290 nm and λem 322 nm), and method detection limits of 0.8 ng/mL plasma were reached. These were sufficiently low to determine the plasma concentration‐time profiles for both compounds following oral administration of 2.5 mg and 5 mg midodrine hydrochloride. The assay in serum or plasma was linear in the range of 1 to 15 ng analyte/mL, the recovery was >95%, and the reproducibility was sufficient. The assay was rugged and was maintained by routinely changing the home‐made, dry packed pre‐column every 20th serum injection.
Solid phase extraction for an improved assay of physostigmine in biological fluids
Authors: Hurst P. R. , Whelpton R. 
Published: May 2005

AbstractA simple, selective and very sensitive assay is described for the quantification of physostigmine in blood, plasma and urine. The most appropriate solid phase column was selected after a systematic investigation of nine types of phase. The conditions for solid phase extraction were optimized using [3H]physostigmine so that the overall recoveries were >90%. Physostigmine was retained on alkaline treated cyanopropyl columns and eluted into the minimum volume of methanol, obviating the need for an evaporation step. Extracted samples were quantified by HPLC with a three electrode coulometric detection system. The limit of detection was 50 pg/mL for a 0.5 mL plasma sample. The precision (CV) for 0.5 mL plasma samples containing 50 pg was 8.1%. Application of the method to plasma, blood and urine samples is presented.
Identification by gas chromatography/mass spectrometry of long‐chain fatty acids and alcohols from hamster meibomian glands using picolinyl and nicotinate derivatives
Authors: Harvey D. J. 
Published: May 2005

AbstractMeibomian secretions from the hamster were hydrolysed with base and examined as TMS, [2H9]TMS, methyl ester/TMS, picolinyl ester/TMS and nicotinate/TMS derivatives by capillary GC/MS. Over 90 compounds, representing over 89% of the hydrolysed fraction, were identified. Fatty acids with chain lengths from 10 to 32 carbon atoms were found, the most common of these were in the C15 to C18 and in the C25 to C30 regions. Chain types were predominantly iso or anteiso branched, mono‐unsaturated (C16 and C18) and straight. Fatty alcohols were mainly from the iso or anteiso series and tended to have longer chain lengths; the major alcohols had anteiso‐25 and 27 and iso‐26‐chains. In these respects the secretions were similar to those reported earlier from other species, although fewer mono‐unsaturated compounds with longer chains (C20 to C30 region) were found than in the rat and human. The steroid fraction was characterized by a larger number of compounds than normally present in secretions of this type. The major compound was cholesterol, in common with that in all other examined species except the rabbit.
Evaluation of pyrimido[5,4‐d]pyrimidine derivatives as peroxyoxalate chemiluminescence reagents using a flow injection system
Authors: Nakashima Kenichiro , Maki Kouichi , Akiyama Shuzo , Imai Kazuhiro 
Published: May 2005

AbstractEighteen kinds of pyrimido[5,4‐d]pyrimidines together with several commercially available fluorescent compounds such as perylene, Rhodamine B, etc., were evaluated as the reagents for a peroxyoxalate chemiluminescence (CL) detection system by using a flow injection method. The peroxyoxalate CL reaction employed consists of bis(2,4,6‐trichlorophenyl)oxalate, hydrogen peroxide, triethylamine, and a fluorophore. Under the conditions used, 2,6‐bis[di‐(2‐hydroxyethyl)amino]‐4,8‐dipiperidinopyrimido[5,4‐d]pyrimridine (Dipyridamole) and 2,4,6,8‐tetrathiomorpholinopyrimido[5,4‐d]pyrimidine (1i) gave very intense chemiluminescence intensities which were larger than those of any other commercially available fluorescent compounds tested (e.g., 10 times larger than that of perylene).
Determination of nitrated pyrenes and their derivatives by high performance liquid chromatography with chemiluminescence detection after online electrochemical reduction
Authors: Imaizumi Noriko , Hayakawa Kazuichi , Suzuki Yasuo , Miyazaki Motoichi 
Published: May 2005

AbstractA sensitive and selective high performance liquid chromatographic method for the simultaneous determination of nitrated polycyclic aromatic hydrocarbons and their reduced compounds has been developed. As the model compounds for the proposed method, pyrene, aminopyrene, nitrosopyrene, and several nitrated pyrenes were used. After separation on a reversed phase column, both nitropyrenes and nitrosopyrene which were not fluorescent, were electrochemically reduced to strongly fluorescent aminopyrenes, and detected chemilumigenically by using bis(2,4,6‐trichlorophenyl)oxalate and hydrogen peroxide as post column reagents. Their detection limits were all at the fmol levels, which were one or two orders lower than those by fluorescence detection.By the proposed method, nitropyrene, 1,3‐, and 1,8‐dinitropyrenes were detected in sooty emissions of cars after simple purifications.
Determination of fluorescent cyanobenz[f]isoindole derivatives of dopamine and norepinephrine using high performance liquid chromatography with chemiluminescence detection
Authors: Kawasaki Takao , Imai Kazuhiro , Higuchi Takeru , Wong Osborne S. 
Published: May 2005

AbstractDopamine (DA), norepinephrine (NE) and 3,4‐dihydroxybenzylamine (DHBA) are converted to highly fluorescent cyanobenz[f]isoindole (CBI) derivatives by reacting these amines with naphthalene‐2,3‐dicarboxaldehyde in the presence of cyanide ion. Femtomole amounts of these CBI derivatives separated by reverse‐phase high performance liquid chromatography can be detected by a post‐column chemiluminescence system utilizing bis(2,4‐dinitrophenyl) oxalate and hydrogen peroxide. Linear detection response was observed between 1 to 600 fmol, giving a signal to noise ratio of approximately 15 at the 1 fmol level. An assay procedure was developed for the determination of DA and NE in 20 μL of urine sample using DHBA as the internal standard.
Identification of 17‐hydroxyprogesterone and other steroid hormones in saliva from a normal child and patients with congenital adrenal hyperplasia by plasmaspray liquid chromatography/mass spectrometry
Authors: Shindo Noriko , Yamauchi Noriko , Murayama Kimie , Fairbrother Ann , Krolik Stefan 
Published: May 2005

AbstractA very sensitive, selective and simultaneous method for the analysis of salivary steroid hormones was examined by discharge‐assisted thermospray liquid chromatography mass spectrometry (plasmaspray LC/MS). Plasmaspray LC/MS gave [M + M]+ or [MH — H2O]+ as a predominant ion in most of the steroids in this work and in some cases fragment ions were also observed. Eight salivary steroid hormones, pregnenolone, 17‐hydroxypregnenolone, progesterone, 17‐hydroxyprogesterone, 11‐deoxycortisol, cortisol, aldosterone, and testosterone were identified within 10 minutes using the selected ion monitoring technique in conjunction with plasmaspray LC/MS. Progesterone, 17‐hydroxyprogesterone, cortisol, aldosterone and testosterone were detected in 1 mL of saliva from a normal child and two patients with congenital adrenal hyperplasia.