bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chiral analysis of milnacipran by a nonchiral HPLC – circular dichroism: Improvement of the linearity of dichroic response by temperature control
Authors: Lecoeur‐Lorin Marie , Delépée Raphaël , Ribet Jean‐Paul , Morin Philippe 
Published: September 2008

AbstractThe determination of the enantiomeric excess (e.e.) of a basic drug has been investigated in LC using a nonchiral stationary phase and a circular dichroism (CD) detector in order to avoid expensive chiral columns. The CD detector records both dichroic (Δε) and UV (ε) signals at the same wavelength and calculates the anisotropy factor (g = Δε/ε), which is linearly related to the e.e. The enantiomeric and chemical composition of a chiral drug can be simultaneously determined on a nonchiral HPLC support. However, the g factor from the CD signal is temperature dependent. Indeed, the temperature has an influence on the stability of the CD signal and the linear regression between g factor and the e.e. of 1R,2S‐enantiomer. So, a decrease in temperature gives rise to an improvement of the above‐mentioned linearity correlation. After optimization of chromatographic parameters (porous graphitic carbon‐based column, methanol/ phosphate buffer as mobile phase) and selection of CD wavelength, a linear regression of g factor versus e.e. of 1R,2S‐enantiomer was obtained at temperature‐controlled CD detection and an LOQ of 94% was found. The enantiomeric composition of milnacipran was determined with good accuracy.
Effect of large volume injection of hydrophobic solvents on the retention of less hydrophobic pharmaceutical solutes in RP‐LC
Authors: Udrescu Stefan , Medvedovici Andrei , David Victor 
Published: September 2008

AbstractInjection of large volumes of samples in solvents other than mobile phase composition has been proved for some less hydrophobic compounds. Thus, the retention behavior of several compounds of pharmaceutical interest (isosorbide‐2‐nitrate, isosorbide‐5‐nitrate, tropicamide, pentoxifylline, and methyl p‐hydroxybenzoate) was studied by using different hydrophobic solvents (n‐hexane, n‐heptane, or i‐octane) as sample solvents. Two types of stationary phases were used: octyl and octadecyl modified silica (both of Zorbax Eclipse type). The experiments showed a linear dependence between capacity factor of each solute and sample injection volume, up to maximum volume values of about 680 μL for C8 stationary phase and 580 μL for C18 stationary phase, when the solutes are no longer retained in stationary phase. Injection of large volumes of these hydrophobic solvents is thus possible in RP‐LC with a gradual reduction of retention and peak efficiency. Two major conditions are however necessary in order to apply such an injection approach: the solutes must have a proper solubility in hydrophobic solvents and meanwhile they have to be less hydrophobic than the sample solvent in order to avoid competition with solvent molecules in partitioning between mobile and stationary phases.
Combined effect of temperature and organic modifier concentration on the retention under single mode gradient conditions in reversed‐phase HPLC
Authors: Pappa‐Louisi Adriani , Nikitas Panos , Zisi Christiana , Papachristos Kostas 
Published: September 2008

AbstractThe combined effect of temperature, T, and organic modifier concentration, φ, on the retention under gradient conditions in RPLC is studied by considering, both theoretically and experimentally gradients, of φ at constant T and gradients of T at constant φ. Two approaches are examined: in the first approach the prediction of the elution time of a sample solute is based on the isocratic/isothermal properties of this solute. The second approach is based on a direct fitting procedure of a proper retention model to 2‐D isocratic/T‐gradient or isothermal/φ‐gradient retention data. These approaches were tested using alkylbenzes in eluting systems modified by ACN. We found that both approaches can give excellent predictions under certain prerequisites. However, the first approach exhibits the notable advantage that it can be used effectively to predict retention times under any kind of φ‐gradients at constant T or T‐gradients at constant φ. The second approach has the advantage that it is relatively simple but its applicability is very restricted since its predictions are satisfactory only if the gradients are of the same kind with those used in the fitting procedure and the conditions lie within those used for fitting.
Determination of carbohydrate‐deficient transferrin in human serum by two capillary zone electrophoresis methods and a direct immunoassay: Comparison of patient data
Authors: Marti Ulrich , Joneli Jeannine , Caslavska Jitka , Thormann Wolfgang 
Published: September 2008

AbstractData obtained with two CZE assays for determining carbohydrate‐deficient transferrin (CDT) in human serum under routine conditions, the CAPILLARYS CDT and the high‐resolution CEofix (HR‐CEofix) CDT methods, are in agreement with patient sera that do not exhibit interferences, high trisialo‐transferrin (Tf) levels or genetic variants. HR‐CEofix CDT levels are somewhat higher compared to those obtained with the CAPILLARYS method and this bias corresponds to the difference of the upper reference values of the two assays. The lower resolution between disialo‐Tf and trisialo‐Tf observed in the CAPILLARYS system (mean: 1.24) compared to HR‐CEofix (mean: 1.74) is believed to be the key for this difference. For critical sera with high trisialo‐Tf levels, genetic variants, or certain interferences in the β‐region, the HR‐CEofix approach is demonstrated to perform better than CAPILLARYS. However, the determination of CDT with the HR‐CEofix method can also be hampered with interferences. Results with disialo‐Tf values larger than 3% in the absence of asialo‐Tf should be evaluated with immunosubtraction of Tf and possibly also confirmed with another CZE method or by HPLC. Furthermore, data gathered with the N Latex CDT direct immunonephelometric assay suggest that this assay can be used for screening purposes. To reduce the number of false negative results, CDT data above 2.0% should be confirmed using a separation method.
Determination of amino acid neurotransmitters in human cerebrospinal fluid and saliva by capillary electrophoresis with laser‐induced fluorescence detection
Authors: Deng Ying‐Hua , Wang Hong , Zhang Hua‐Shan 
Published: September 2008

AbstractA CE–LIF detection method has been developed to identify and quantitate six amino acid neurotransmitters including glutamic acid, aspartic acid, γ‐aminobutyric acid, glycine, taurine, and glutamine. N‐Hydroxysuccinimidyl fluorescein‐O‐acetate, a fluorescein‐based dye, was employed for the derivatization of these neurotransmitters prior to CE–LIF analysis. Different parameters which influenced separation and derivatization were optimized in detail. Under optimum conditions, linearity was achieved within concentration ranges of up to three orders of magnitudes for those analytes with correlation coefficients from 0.9989 to 0.9998. The LODs ranged from 0.06 nM to 0.1 nM, and are thus superior or equivalent to those previously reported in the literature using CE–LIF detection. The proposed method has been successfully applied to the determination of amino acid neurotransmitters in biological samples such as human cerebrospinal fluid and saliva with satisfactory recoveries.
Recovering oil from corn ethanol fermentation by‐products
Authors: Wang Tong 
Published: September 2008

AbstractRemoving oil from by‐products of corn fermentation is desirable for improving feed quality and providing an alternative source of oil for biodiesel production. We are investigating ways to increase oil removal by centrifugation during the typical dry grind fermentation process. We have to first make oil or oil containing “bodies” go into the liquid phase and then free the oil so it can be separated by centrifugation. This report outlines our research approaches and results.
Amphiphilic Branched Polymers as Antimicrobial Agents
Authors: Pasquier Nicolas , Keul Helmut , Heine Elisabeth , Moeller Martin , Angelov Borislav , Linser Sebastian , Willumeit Regine 
Published: September 2008

AbstractCationic amphiphilic polymers were prepared from PEI and functional ethylene carbonates bearing cationic, hydrophobic or amphiphilic groups. The polymers are designed to exhibit antimicrobial properties. In a one‐step addition, different functional ethylene carbonates were added to react with the primary amine groups of PEI. The water soluble polymers were studied regarding their ability to form soluble aggregates. Their hydrodynamic radii, their inhibition potential against proliferation of E. coli and their hemolytic potential were determined. A structure‐property relationship was established by analyzing the antimicrobial activity as a function of the ratio of alkyl to cationic groups, length of the alkyl chains, and molecular weight of the PEI.magnified image
Analysis of macrolide antibiotics, using liquid chromatography‐mass spectrometry, in food, biological and environmental matrices
Authors: Wang Jian 
Published: September 2008

AbstractMacrolides are a group of antibiotics that have been widely used in human medical and veterinary practices. Analysis of macrolides and related compounds in food, biological, and environmental matrices continue to be the focus of scientists for the reasons of food safety, pharmacokinetic studies, and environmental concerns. This article presents an overview on the primary biological properties of macrolides and their associated analytical issues, including extraction, liquid chromatography‐mass spectrometry (LC‐MS), method validation, and measurement uncertainty. The main techniques that have been used to extract macrolides from various matrices are solid‐phase extraction and liquid–liquid extraction. Conventional liquid chromatography (LC) with C18 columns plays a dominant role for the determination of macrolides, whereas ultra‐performance liquid chromatography (UPLC) along with sub‐2 µm particle C18 columns reduces run time and improves sensitivity. Mass spectrometry (MS), serving as a universal detection technique, has replaced ultraviolet (UV), fluorometric, and electrochemical detection for multi‐macrolide analysis. The triple‐quadrupole (QqQ), quadrupole ion trap (QIT), triple‐quadrupole linear ion trap, time‐of‐flight (TOF), and quadrupole time‐of‐flight (QqTOF) mass spectrometers are current choices for the determination of macrolides, including quantification, confirmation, identification of their degradation products or metabolites, and structural elucidation. LC or UPLC coupled to a triple‐quadrupole mass spectrometer operated in the multiple‐reaction monitoring (MRM) mode (LC/MS/MS) is the first choice for quantification. UPLC‐TOF or UPLC‐QqTOF has been recognized as an emerging technique for accurate mass measurement and unequivocal identification of macrolides and their related compounds. © 2008 Crown in the right of Canada. Published by John Wiley & Sons, Inc., Mass Spec Rev 28:50–92, 2009
Neuropathy as a potential complication of levodopa use in Parkinson's disease
Authors: Toth Cory , Brown Martin Sutton , Furtado Sarah , Suchowersky Oksana , Zochodne Douglas 
Published: September 2008

AbstractThe presence and potential etiologies of peripheral neuropathy (PN) in patients with Parkinson's Disease (PD) is unknown. We examined for presence of PN in patients with PD. From a PD patient population of 500 patients screened for features of symptomatic PN, patients were further selected for clinical, electrophysiological, and laboratory studies related to PN. This PD patient population with idiopathic PN (PD‐IPN) was compared to a group of PD patients without PN (PD‐only), and a large group of patients without PD with idiopathic PN (IPN) for abnormalities in Cbl, fasting homocysteine (Hcy), and fasting methylmalonic acid (MMA) levels. PD‐IPN and IPN patients identified with abnormalities in Cbl, Hcy, or MMA levels were treated with intramuscular Cbl for 1 to 2 years. Of 49 PD patients with symptomatic PN, 34 patients (69%) had PD‐IPN, and 32/34 (94%) had abnormal Hcy or MMA levels as compared to 26/258 (10%) of IPN patients. Cumulative lifetime L‐dopa dosage and fasting MMA levels were associated with PN severity. Cbl therapy led to improvements in Hcy and MMA levels in all groups, and PN in PD‐IPN patients stabilized during therapy. PN in PD patients may be associated with iatrogenic Cbl metabolic abnormalities. Alternatively PN may be a peripheral nervous system manifestation of PD. © 2008 Movement Disorder Society
The use of smell identification tests in the diagnosis of Parkinson's disease in Brazil
Authors: Silveira‐Moriyama Laura , Carvalho Margarete de Jesus , Katzenschlager Regina , Petrie Aviva , Ranvaud Ronald , Barbosa Egberto Reis , Lees Andrew J. 
Published: September 2008

AbstractSmell identification tests may be of routine clinical value in the differential diagnosis of PD but are subject to cultural variation and have not been systematically evaluated in the Brazilian population. We have applied culturally adapted translations of the University of Pennsylvania 40‐item smell identification test (UPSIT‐40) and the 16‐item identification test from Sniffin' Sticks (SS‐16) to nondemented Brazilian PD patients and controls. Pearson's correlation coefficient between the test scores was 0.76 (95% CI 0.70–0.81, n = 204, P < 0.001). To calculate reliability measures for each test we used the diagnosis (either PD or control) as outcome variable for separate logistic regression analyses using the score in the UPSIT‐40 or the SS‐16 as a covariate. The SS‐16 specificity was 89.0% with a sensitivity of 81.1% (106 PD and 118 controls). The UPSIT‐40 specificity was 83.5% and its sensitivity 82.1% (95 PD and 109 controls). Regression curves were used to associate an individual's smell test score with the probability of belonging to the PD, as opposed to the control group. Our data provide support for the use of the UPSIT‐40 and SS‐16 to help distinguish early PD from controls. © 2008 Movement Disorder Society
Chorea‐acanthocytosis: Report of two Brazilian cases
Authors: Rodrigues Guilherme Riccioppo , Walker Ruth H. , Bader Benedikt , Danek Adrian , Marques Wilson , Tumas Vitor 
Published: September 2008

AbstractChorea‐acanthocytosis (ChAc) is a neurodegenerative disorder characterized by chorea, neuropsychiatric disturbances and acanthocytosis, caused by mutations of VPS13A. This gene produces the protein chorein which is absent in patients with ChAc on Western blot assay. We report the first two Brazilian patients with ChAc confirmed by chorein detection. Patient 1 is a 36‐year‐old man with chorea, epilepsy, myopathy, and suicidal ideation. Patient 2 is a 60‐year‐old woman with a 30 year history of psychiatric disturbances, epilepsy, choreic movements, and myopathy. Both patients had acanthocytosis, elevated creatine kinase (CK), and absence of chorein on Western blot analysis. The presence of chorea and neuropsychiatric disturbances associated with elevated CK levels, epilepsy, hyporeflexia, and acanthocytosis suggests the diagnosis of ChAc. Chorein assay of peripheral blood confirms the diagnosis. © 2008 Movement Disorder Society
Traffic matrix estimation based on a square root Kalman filtering algorithm
Authors: Zhou Jingjing , Yang Jiahai , Yang Yang , Liu Hongbo , Zeng Ming 
Published: September 2008

AbstractThe traffic matrix (TM) is one of the crucial inputs for many network management and traffic engineering tasks. As it is usually impossible to directly measure traffic matrices, it becomes an important research topic to infer them by modeling incorporating measurable data and additional information. Many estimation methods have been proposed so far, but most of them are not sufficiently accurate or efficient. Researchers are therefore making efforts to seek better estimation methods. Of the proposed methods, the Kalman Filtering method is a very efficient and accurate method. However, the error covariance calculation components of Kalman filtering are difficult to implement in realistic network systems due to the existence of ill‐conditioning problems. In this paper, we proposed a square root Kalman filtering traffic matrix estimation (SRKFTME) algorithm based on matrix decomposition to improve the Kalman filtering method. The SRKFTME algorithm makes use of the evolution equations of forecast and analysis error covariance square roots. In this way the SRKFTME algorithm can ensure the positive definiteness of the error covariance matrices, which can solve some ill‐conditioning problems. Also, square root Kalman filtering will be less affected by numerical problems. Simulation and actual traffic testing results show superior accuracy and stability of SRKFTME algorithm compared with prior Kalman filtering methods. Copyright © 2008 John Wiley & Sons, Ltd.
Second trimester maternal serum ADAM12 levels in Down's syndrome pregnancies
Authors: Donalson Kim , Turner Steve , Wastell Hilary , Cuckle Howard 
Published: September 2008

AbstractObjectiveTo estimate the utility of maternal serum ADAM12 as a Down's syndrome marker.MethodsSamples from 71 Down's syndrome affected pregnancies were retrieved from − 20 °C storage together with 710 controls matched for gestation and storage time. ADAM12 was measured prior to identification of the affected pregnancies, and expressed in multiples of the gestation‐specific median (MoM).ResultsThe median ADAM12 level in the affected pregnancies was 1.36 MoM with a 10th–90th centile range of 0.90–1.94 MoM compared with 1.01 and 0.65–1.52 MoM in the unaffected control pregnancies (P = < 0.0001, two‐side Wilcoxon Rank Sum Test). The Mahalanobis distance between the medians was 0.96 compared with 0.92, 1.18, 1.07 and 1.24 for α‐fetoprotein, intact human chorionic gonadotrophin (hCG), unconjugated estriol and inhibin‐A respectively in the same samples. In unaffected pregnancies there were highly statistically significant correlations between ADAM12 and each of the other markers; in the affected pregnancies the only significant correlations were with hCG (P≤0.0001) and inhibin‐A (P≤0.05). Statistical modelling predicted that ADAM12 as a fifth marker could increase the detection rate by 2–3% or reduce the false‐positive rate by 0.9–1.7%.ConclusionsADAM12 is a second trimester marker of Down's syndrome, with discriminatory power similar to existing markers. It could be considered in multi‐marker combinations. Copyright © 2008 John Wiley & Sons, Ltd.
Evaluation of body mass index, pre‐vaccination serum progesterone levels and anti‐anthrax protective antigen immunoglobulin G on injection site adverse events following anthrax vaccination in women
Authors: Zhang Yujia , Martin Stacey W. , Rose Jr Charles E. , Biagini Raymond E. , Franzke Laura H. , Smith Jerry P. , Sammons Deborah L. , Robertson Shirley A. , McNeil Michael M. 
Published: September 2008

AbstractBackgroundIn 2002, CDC initiated the Anthrax Vaccination Program (AVP) to provide voluntary pre‐exposure anthrax vaccination for individuals at high risk for exposure to Bacillus anthracis spores. The AVP offered an opportunity to investigate hypothesized reasons for a reported gender difference in injection site adverse events (AEs) following anthrax vaccine adsorbed (AVA).ObjectivesTo evaluate in women the impact of body mass index (BMI), pre‐vaccination serum progesterone levels, and pre‐vaccination anti‐anthrax protective antigen immunoglobulin G concentrations (anti‐PA IgG) on the occurrence of AEs following subcutaneous AVA vaccination.MethodsParticipants' BMI was determined at enrollment. Also, pre‐vaccination blood samples were assayed for serum progesterone and anti‐PA IgG. Post‐vaccination solicited AEs were recorded by participants using a 4‐day diary card.ResultsObese group had an elevated risk for arm soreness. Decreased pre‐vaccination serum progesterone level was associated with arm swelling. Increased pre‐vaccination anti‐PA IgG was associated with itching on the arm; and within the obese group, was associated with arm swelling, lump or knot, redness, soreness, and warmth.ConclusionsIn AVA vaccinated women, obesity was associated with arm soreness and decreased pre‐vaccination serum progesterone levels were associated with increased rate of arm swelling. Increased pre‐vaccination anti‐PA IgG may be associated with an increased frequency of itching on the arm, and in obese women, may increase the occurrence of arm swelling, lump or knot, redness, and warmth. Administering AVA according to a woman's menstrual phase may reduce the occurrence of certain injection site reactions. Copyright © 2008 John Wiley & Sons, Ltd.
Preferential formation of electroactive crystalline phases in poly(vinylidene fluoride)/organically modified silicate nanocomposites
Authors: Ramasundaram Subramaniyan , Yoon Sun , Kim Kap Jin , Park Cheolmin 
Published: September 2008

AbstractThe role of organically modified silicate (OMS), Lucentite STN on the formation of β‐crystalline phase of poly(vinylidene fluoride) (PVDF) is investigated in the present study. The OMS was solution blended with PVDF and cast on glass slide to form PVDF‐OMS nanocomposites. Solution cast samples were subjected to various thermal treatments including annealing (AC‐AN), melt‐quenching followed by annealing (MQ‐AN), and melt‐slow cooling (MSC). Fourier‐transform infrared spectroscopy (FT‐IR), wide angle X‐ray diffraction (WAXD), and differential scanning calorimetry (DSC) were used to investigate the crystalline structure of thermally treated samples. As a special effort, the combination of in situ thermal FT‐IR, WAXD, and DSC studies was utilized to clearly assess the thermal properties. FT‐IR and WAXD results of MQ‐AN samples revealed the presence of β‐phase of PVDF. Ion‐dipole interaction between the exfoliated clay nanolayers and PVDF was considered as a main factor for the formation of β‐phase. Melt‐crystallization temperature and subsequent melting point were enhanced by the addition of OMS. Solid β‐ to γ‐crystal phase transition was observed from in situ FT‐IR and WAXD curves when the representative MQ‐AN sample was subjected to thermal scanning. Upon heating, β‐phase was found to disappear through transformation to the thermodynamically stable γ‐phase rather than melting directly. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2173–2187, 2008
Step‐like melting mechanisms of isothermally crystallized isotactic polypropylene
Authors: Medellín‐Rodríguez Francisco J. , Mata‐Padilla Manuel , Sánchez‐Valdes Saul , Vega‐Díaz Sofia , Dávalos‐Montoya Olga 
Published: September 2008

AbstractThe complex melting behavior of isotactic polypropylene, after isothermal crystallization, was studied within the context of step‐like melting mechanisms which were previously proposed for high temperature polymers. The morphological characteristics of the melting process were also studied as a function of molecular weight, and close similarities were observed with respect to high temperature polymers. Positive birefringence crystals of low molecular weight samples developed double melting behavior in three steps. The first melting step was assigned to continuous melting of secondary crosshatch reversing lamellae, together with recrystallization of the remaining isothermal crystals. In the second melting step (first melting endotherm), crystals tended to lose their original coarse negative birefringence due to melting of secondary reversing branching. This effect rendered new, finer texture, but still negative birefringence crystals. In the third melting step (second melting endotherm), there was a combination of melting of two crystal populations, one consisting of the remaining fraction of reversing primary crystals, and the other consisting of nonreversing primary crystals. A crosshatch secondary branching model was therefore proposed to explain the overall results. Mixed birefringence spherulites of high molecular weight samples displayed similar, although proportional, behavior under identical crystallization and melting conditions corroborating the proposed melting mechanism. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2188–2200, 2008