bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification, quantification and comparison of major non‐polar lipids in normal and dry eye tear lipidomes by electrospray tandem mass spectrometry
Authors: Ham Bryan M. , Jacob Jean T. , Keese Monica M. , Cole Richard B. 
Published: November 2004

AbstractMillions of individuals suffer from a health condition known as keratoconjunctivitis sicca (KCS, also known as ‘dry eye’). Studies have indicated that the lipids in the tear film layer, which covers the outer portion of the eye, may be directly correlated with the existence of dry eye syndrome. By identifying and comparing the major, non‐polar lipids in normal eye tears with a dry eye model, it may be possible to identify a symptom of, or a contributing factor to, dry eye. Electrospray tandem mass spectrometry (ES‐MS/MS) was used to identify and compare the non‐polar lipids, detected as lithium adducts, from normal and dry eye tear samples obtained from rabbits. A limited number of normal human tear samples were also examined for lipid content, and a close resemblance to rabbit was observed. Three distinct regions were delineated in the ES mass spectra of the non polar lipids, m/z 20–500, 500–800 and 800–1100. A common feature noted among identified lipid components was a glycerol backbone with fatty acyl substituents attached. Product ion spectra were obtained for lithiated monoacyl‐, 1,2‐ and 1,3‐diacyl‐ and triacylglyceride standards. Newly proposed structures and fragmentation pathways for the major product ions are presented for the 1,2‐ and 1,3‐diglycerides, and also for the monoglyceride. New approaches to distinguishing asymmetric 1,2‐diglycerides and 1,2‐ from 1,3‐diglycerides are proposed. For the rabbit tear samples, the m/z 20–500 range contains monoester diols with empirical formulas CnH2nO4, the m/z 500–800 range includes diesters with empirical formulas CnH2n−2O5 and the m/z 800–1100 range contains triesters with empirical formulas CnH2n−4O6. Also found in the extracts were three isoprene acetals (terpenoids). Copyright © 2004 John Wiley & Sons, Ltd.
Structural elucidation and identification of alkaloids in Rhizoma Coptidis by electrospray ionization tandem mass spectrometry
Authors: Wang Daowu , Liu Zhiqiang , Guo Mingquan , Liu Shuying 
Published: November 2004

AbstractSimple, convenient, sensitive and accurate analytical methods are needed for the structural characterization and identification of alkaloid components in Rhizoma Coptidis in traditional Chinese herbal medicine, which has important bioactivity. In this work, the identification of alkaloid compounds in Rhizoma Coptidis was investigated by obtaining molecular mass information using electrospray ionization mass spectrometry (ESI‐MS). Multi‐stage tandem mass spectrometric (ESI‐MSn) data for the alkaloid compounds were used for detailed structural characterization, then structure information was obtained by comparison of the fragmentation mechanisms of both alkaloids in Rhizoma Coptidis and standard samples of berberine, palmatine, coptisine and jatrorrhizine by MS. Based on the results obtained, the structure of a novel compound was elucidated. The results of the experiments demonstrate that ESI‐MSn is a sensitive, selective and effective tool for the rapid determination of alkaloids in Rhizoma Coptidis. Copyright © 2004 John Wiley & Sons, Ltd.
Firm or subgroup culture: where does fitting in matter most?
Authors: Adkins Bryan , Caldwell David 
Published: November 2004

AbstractUsing the Organizational Culture Profile (OCP), this research investigated the extent to which fit between individuals (n = 136) and their competency groups (P–G fit) and the organization (P–O fit) were related to job satisfaction. Even in a consulting firm with a strong organization culture, we found small, but interpretable, differences between the value‐based cultures of the competency groups in the firm. Although the two forms of fit were highly correlated, both individual consultants' fit with the culture of their competency group and the organization as a whole were significant predictors of job satisfaction. Copyright © 2004 John Wiley & Sons, Ltd.
Stability, sensory quality, texture properties and nutritional value of fish oil‐enriched spreadable fat. Wojciech Kolanowski, Franciszek Swiderski, Danuta Jaworska, Stanislaw Berger Journal of the Science of Food and Agriculture 84(15):2135–2141 (2004) DOI: 10.1002/jsfa.1770 (published online 3 August 2004)
Authors: Kolanowski Wojciech , Swiderski Franciszek , Jaworska Danuta , Berger Stanislaw 
Published: November 2004

AbstractThe original article to which this Correction refers was published in Journal of the Science of Food and Agriculture 84(15):2135–2141 (2004) DOI: 10.1002/jsfa.1770 (published online 3 August 2004)
Level sets of the first eigenfunction from the rearrangement point of view
Authors: Chu Chie‐Ping 
Published: November 2004

AbstractThe level curves of the first Dirichlet eigenfunction for the Laplace operator of a convex plane domain is convex. We make this observation by a new rearrangement technique. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lagrangian solutions to systems of real principal type
Authors: Hansen Sönke , Röhrig Daniel 
Published: November 2004

AbstractWe derive a transport equation for the principal symbol of a Fourier integral operator which solves a real principal type system. We apply this to Lamé's system of elastodynamics and obtain transport equations which remain valid at caustics. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The interior transmission problem for anisotropic Maxwell's equations and its applications to the inverse problem
Authors: Haddar Houssem 
Published: November 2004

AbstractThe interior transmission problem appears naturally in the study of the inverse scattering problem of determining the shape of a penetrable medium from a knowledge of the time harmonic incident waves and the far field patterns of the scattered waves. We propose a variational study of this problem in the case of Maxwell's equations in an inhomogeneous anisotropic medium. Then we apply the obtained results to build an ‘extented far field’ operator and give a characterization of the medium from the knowledge of the range of this operator. We then show how the linear sampling method can be viewed as an approximation of this characterization. Copyright © 2004 John Wiley & Sons, Ltd.
Degenerate scale problem when solving Laplace's equation by BEM and its treatment
Authors: Chen J. T. , Lin S. R. , Chen K. H. 
Published: November 2004

AbstractIn this paper, Laplace problems are solved by using the dual boundary element method (BEM). It is found that a degenerate scale problem occurs if the conventional BEM is used. In this case, the influence matrix is rank deficient and numerical results become unstable. Both the circular and elliptical bars are studied analytically in the continuous system. In the discrete system, the Fredholm alternative theorem in conjunction with the SVD (Singular Value Decomposition) updating documents is employed to sort out the spurious mode which causes the numerical instability. Three regularization techniques, method of adding a rigid body mode, hypersingular formulation and CHEEF (Combined Helmholtz Exterior integral Equation Formulation) concept, are employed to deal with the rank‐deficiency problem. The addition of a rigid body term, c, in the fundamental solution is proved to shift the original degenerate scale to a new degenerate scale by a factor e−c. The torsion rigidities are obtained and compared with analytical solutions. Numerical examples including elliptical, square and triangular bars were demonstrated to show the failure of conventional BEM in case of the degenerate scale. After employing the three regularization techniques, the accuracy of the proposed approaches is achieved. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of DMSO used as solvent in copper mediated living radical polymerization
Authors: Monge Sophie , Darcos Vincent , Haddleton David M. 
Published: November 2004

AbstractThe use of DMSO as solvent for transition metal mediated living radical polymerization was investigated using copper (I) bromide/N‐(n‐propyl)‐2‐pyridyl‐methanimine catalyst system and ethyl‐2‐bromoisobutyrate as initiator. The best conditions for polymerization in DMSO of different methacrylates (MMA, BMA, DMAEMA, HEMA) were determined. In all cases, the measured number‐average molar mass of the product increased linearly with monomer conversion in agreement with the theoretical Mn with low polydispersity products (1.16 < PDI < 1.4) achieved. Solvent was found to play a crucial role in the process. The effect of the polar solvent has been investigated and it was shown that DMSO could coordinate copper (II), increasing the activation process, or copper (I), changing the nature of the copper catalyst by competitive complexation of ligand and DMSO. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6299–6308, 2004
Influence of the alkene structure on the mechanism and kinetics of thiol–alkene photopolymerizations with real‐time infrared spectroscopy
Authors: Roper Todd M. , Guymon C. A. , Jönsson E. S. , Hoyle C. E. 
Published: November 2004

AbstractThe effect of the chemical structure on the reactivity of alkenes used in thiol–ene photopolymerizations has been investigated with real‐time infrared spectroscopy. Model studies of thiol–ene photoreactions with various monofunctional hydrocarbon alkenes and the monofunctional thiol ethyl‐3‐mercaptopropionate have been performed to identify and understand structure–reactivity relationships. The results demonstrate that terminal enes react very rapidly with thiol, achieve complete conversion, and are independent of the aliphatic hydrocarbon substituent length. Disubstitution on a single carbon of a terminal ene significantly reduces the reactivity, whereas substitution on the carbon α to the terminal ene has a minimal influence on the reactivity. Internal trans enes display reduced reactivity and a lower overall conversion and deviate from the standard thiol–ene reaction mechanism because of steric strain induced by 1,3‐interactions. The reactivity and conversion of internal trans enes decrease as the substituents on the ene become larger, reaching a minimum when the substituent size is greater than or equal to that of propyl groups. Internal cis enes react rapidly with thiol; however, they undergo a fast isomerization–elimination reaction sequence generating the trans ene, which proceeds to react at a reduced rate with thiol. The reactivity of cyclic enes is dictated by ring strain, stereoelectronic effects, and hydrogen abstractability. The reactivity trends in the model studies have been used to explain the photopolymerization mechanism and kinetics of a series of multifunctional thiol–ene systems. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6283–6298, 2004
Effect of the composition ratio of copolymerized poly(carbonate) glycol on the microphase‐separated structures and mechanical properties of polyurethane elastomers
Authors: Kojio Ken , Nonaka Yoshiteru , Masubuchi Tetsuo , Furukawa Mutsuhisa 
Published: November 2004

AbstractRandomly copolymerized poly(carbonate) glycols were employed as starting materials for the synthesis of polyurethane elastomers (PUEs). The poly(carbonate) glycols had hexamethylene (C6) and tetramethylene (C4) units between carbonate groups in various composition ratios (C4/C6 = 0/100, 50/50, 70/30, and 90/10), and the number‐average molecular weights of these poly(carbonate) glycols were 1000 and 2000. The PUEs were synthesized with these poly(carbonate) glycols, 4,4′‐diphenylmethane diisocyanate, and 1,4‐butanediol by a prepolymer method. Differential scanning calorimetry measurements revealed that the difference between the glass‐transition temperature of the soft segment in the PUEs and the glass‐transition temperature of the original glycol polymer decreased and the melting point of the hard‐segment domain increased with an increasing C4 composition ratio. The microphase separation of the poly(carbonate) glycol‐based PUEs likely became stronger with an increasing C4 composition ratio. Young's modulus of these PUEs increased with an increasing C4 composition ratio. This was due to increases in the degree of microphase separation and stiffness of the soft segment with an increase in the C4 composition ratio. The molecular weight of poly(carbonate) glycol also influenced the microphase‐separated structure and mechanical properties of the PUEs. The addition of different methylene chain units to poly(carbonate) glycol was quite effective in controlling the microphase‐separated structure and mechanical properties of the PUEs. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4448–4458, 2004
Density functional theory with finite electric field
Authors: Umari P. , Pasquarello Alfredo 
Published: November 2004

AbstractThe method for treating finite electric fields within periodic boundary conditions is used to formally define a density functional depending on the electric field. An exchange and correlation energy functional depending on the electric field is introduced and related to the functional at zero field by a formal expansion with respect to the field. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Optical properties of molecules in solution via hybrid TDDFT/MM simulations
Authors: Sulpizi M. , Röhrig U. F. , Hutter J. , Rothlisberger U. 
Published: November 2004

AbstractThe optical properties of molecules in complex environments were investigated within hybrid time‐dependent density functional theory / molecular mechanics (TDDFT/MM) simulation studies. The potential energy surface in the excited state is described within time‐dependent density functional theory (TDDFT). The solvent is described through a molecular mechanics approach and the effects due to the inhomogeneities of the electric field of the solvent molecules are fully included. The results for different systems including both n → π* and π → π* transitions are discussed. We apply this TDDFT/MM technique to the study of the properties of the ground state and of the first excited singlet state of two different systems: acetone in water and aminocoumarins in water and acetonitrile. Our approach yields quantitative information on the solvent‐induced shifts, both batho‐ and hypsochromic, of the electronic absorption spectra, and on the effect of a protic and an aprotic solvent on the spectral shift. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Crystalline diamond polymorphs analyzed with first‐principles 13C NMR chemical shift calculations
Authors: Sebastiani Daniel 
Published: November 2004

AbstractWe present the fully periodic calculation of nuclear magnetic resonance (NMR) chemical shifts in crystalline diamond polymorphs within density functional theory. The carbon atoms in these systems have identical fourfold coordination, their topology up to their first neighbors is completely the same. The differences occur only with respect to their second neighbors, which are oriented differently in the considered crystals. We focus on the 2H, 4H, 6H, and 15R polymorphs and compare their computed 13C NMR chemical shift spectra to that of cubic diamond. The results show that it should be possible to discriminate between the only slightly different topologies of the diamond polymorphs by means of magic‐angle‐spinning solid‐state NMR experiments. The predicted variations in the solid‐state NMR spectrum are strong enough to allow for a quantitative experimental analysis of such systems. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Unilateral Surgery for Hyperparathyroidism: Indications, Limits, and Late Results—New Philosophy or Expensive Selection without Improvement of Surgical Results?
Authors: Mortier Pierre‐E. , Mozzon Marta M. , Fouquet Olivier P. , Soudan Benoit C. , Huglo Damien G. , Cussac Jean‐F. , Proye Charles A.G. 
Published: November 2004

AbstractWe assessed the “late” results after unilateral parathyroidectomy (PTX) performed for selected indications. From October 1998 throughout March 2001 we operated on 454 patients for hyperparathyroidism (HPT). A positive unifocal 99mtc‐MIBI scan was required for the unilateral approach to be used. Intact parathormone (PTH) measurements were done intraoperatively. Postoperative calcium and PTH serum levels of unilaterally operated patients were checked. Follow‐up has been 16.2 months (range 6–40 months). Of the 454 patients, 336 (74.0%) were not eligible for the unilateral approach; and 125 (27.5%) of the 454 patients had renal HPT. Among the 329 patients with primary HPT, 125 (38.0%) were excluded for well established reasons, and in 77 other cases (23.5%) preoperative imaging results did not allow the unilateral approach. Altogether, 126 patients (38.3%) with primary HPT were selected for the unilateral approach. Of the 126 unilateral operations, 8 (6.3%) had to be converted to a bilateral procedure. Among the 118 patients with a unilateral approach, 3 patients have been reoperated for overlooked contralateral disease, and 13 dropped out of the study. A total of 102 postoperative calcium and PTH serum late levels are known: 90 (88.2%) patients had normal levels; 10 (9.8%) had a high PTH level, and 2 (1.9%) had high ionized calcium levels. The failure rate in selected cases was 4.2% (5/118) (three were reoperated, and two had a supranormal postoperative ionized Ca level). Even with stringent indications, the late results of unilateral surgery (95.8% cure rate) barely matched those of conventional bilateral surgery (97.6% cure rate). The economic impact of such a surgical strategy should be clarified.
Open Minimally Invasive Parathyroid Surgery
Authors: Udelsman Robert , Donovan Patricia I. 
Published: November 2004

AbstractOutpatient minimally invasive parathyroidectomy (MIP) employs (1) preoperative parathyroid localization with high quality sestamibi scans, (2) cervical block anesthesia, (3) limited exploration, and (4) the rapid intraoperative parathyroid hormone assay to confirm an adequate resection. The technical aspects of this procedure are described, and the results obtained in 255 patients who underwent MIP are compared with those of 401 patients who underwent conventional bilateral cervical exploration under general anesthesia. MIP and standard exploration were indistinguishable with regard to high cure and low complication rates. MIP, however, was superior with regard to operating time, length of hospital stay, patient comfort, and costs.
Endoscopic Parathyroid Surgery: Results of 365 Consecutive Procedures
Authors: Henry Jean‐François , Sebag Frédéric , Tamagnini Paola , Forman Céline , Silaghi Horatiu 
Published: November 2004

AbstractIn recent years, several series have documented the feasibility of endoscopic approaches for parathyroid diseases. We performed a retrospective study to evaluate the results of endoscopic parathyroidectomy (EP) in the management of our patients with primary hyperparathyroidism (PHPT). During a 5.5 year period (1998–2003), we operated on 644 patients with PHPT. EP was proposed for patients with sporadic PHPT, without associated goiter, and without previous neck surgery in whom a single adenoma was localized by means of sonography and sestamibi scanning. EP was performed by the lateral approach with insufflation for patients with an adenoma located deep in the neck and by a gasless midline approach for patients whose adenoma was located anteriorly. A quick parathyroid (QPTH) assay was used during the surgical procedures. Among 644 patients with PHPT, 279 (43.3%) were not eligible for EP for the following reasons: associated nodular goiter (116 cases), previous neck surgery (52 cases), suspicion of multiglandular disease (31 cases), lack of preoperative localization (61 cases), and miscellaneous causes (19 cases). EP was performed in 365 patients with sporadic PHPT: 339 lateral access, 25 midline access, and one thoracoscopy. The median operating time was 49 minutes (16–130 minutes). Conversion to conventional parathyroidectomy was required in 49 patients (13.4%) for these reasons: missed adenomas (14 cases), difficulty with the dissection (8 cases), multiglandular disease correctly predicted by QPTH (11 cases), false‐negative QPTH assay results (4 cases), false‐positive sestamibi scan results (11 cases), and 1 false‐positive sonography result. One patient presented with definitive recurrent nerve palsy. Three patients remained hypercalcemic, and one other patient had recurrent hypercalcemia. In conclusion, EP can be proposed for more than half of the patients with PHPT. Immediate results of EP are similar to those obtained with conventional parathyroidectomy, but no conclusions can be drawn in terms of the influence of EP on the outcome of the patients operated on for PHPT.
Single Center Experience in Primary Surgery for Medullary Thyroid Carcinoma
Authors: Ukkat Jörg , Gimm Oliver , Brauckhoff Michael , Bilkenroth Udo , Dralle Henning 
Published: November 2004

AbstractMedullary thyroid carcinoma (MTC) is a rare disease, and most studies are either based on small numbers or multicenter studies with their inherent difficulties. Since 1995, a total of 440 patients with MTC underwent surgery in our clinic. A primary operation was performed in 188 patients (43% of 440). In 60 patients, the primary operation was performed because of a germline RET mutation (“prophylactic surgery”). Most (84%, 158/188) of the patients had pathologic calcitonin levels. Notably, MTC was found in almost 10% (3/30) of patients with normal calcitonin levels. However, all patients with lymph node metastases (LNMs) had elevated calcitonin levels. Total thyroidectomy (TTx) was performed in all patients. Lymph node dissection (LND) was performed at various extensions: one‐compartment LND in 35% (66/188), three‐compartment LND in 31% (58/188), and four‐compartment LND in 29% (22/188). In general, lymph node dissection increased the likelihood of complications. LNM and distant metastases (DM) correlated with the extent of the primary tumor (pT category). The presence of LNM ranged from 17% (pT1 tumor) to 100% (pT4 tumor), whereas the presence of DM ranged from 0% (pT1 tumor) to 81% (pT4 tumor). Biochemical cure (normal calcitonin levels) was obtained in 72% (137/188) of patients. All 60 patients undergoing prophylactic surgery (tumor stage pT0/pT1) were biochemically cured. In contrast, only 60% (77/128) of the remaining patients were cured. The data suggest that primary surgery should be scheduled as soon as possible to treat patients at a node‐negative stage. In the case of normal basal and elevated stimulated calcitonin levels, TTx and cervicocentral LND is recommended. If the basal calcitonin level is elevated, LND should include the cervicolateral compartment.