bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal structures ofα-quartz homeotypes boron phosphate and boron arsenate: structure-property relationships
Authors: Haines Julien , Cambon Olivier , Astier René , Fertey Pierre , Chateau Christian 
Published: February 2004

AbstractThe structures of single crystals of theα-quartz homeotypes boron phosphate and boron arsenate prepared under high-pressure, high-temperature conditions in a belt-type apparatus were determined by X-ray diffraction. Both structures are more distorted with respect to theβ-quartz structure type thanα-quartz itself with average tetrahedral tilt anglesδof 19.7° and 24.6° for BPO4and BAsO4, respectively. The structure of BAsO4is one of the most highly distorted found amongα-quartz homeotypes. It is shown that for the knownα-quartz homeotypes, the density, which can be related to the frequency constant for piezoelectric resonators, scales with the intertetrahedral bridging angleθ.
Three polymorphic forms of dipotassium O-phospho-L-serinate hydrates
Authors: Bryndal Iwona , Picur Bolesław , Lis Tadeusz 
Published: February 2004

Abstract
Three polymorphic forms of dipotassium salt of O-phospho-L-serine were obtained from water solutions at different pH. Two forms (α and β) crystallize in the monoclinic space group P2, while the third (γ) crystallizes in the orthorhombic space group P212121. All crystals are composed of O-phospho-L-serine ions, potassium cations and water molecules of hydration. In all salts, the O-phospho-L-serine moiety exists as a dianion with two negatively charged phosphate groups, one negatively charged carboxyl group and one positively charged ammonium group. The molecular geometry of O-phospho-L-serine (PSer) dianions resembles that found for the zwitterions in crystalline L- and DL-forms of O-phosphoserine. The orientation of the phosphate group relative to the serine backbone is almost trans (–ap) in all three forms. In all forms, there are no significant differences in the values of the bond lengths in the O-phospho-L-serine moiety. The crystal packings are dominated by K…O interactions and intermolecular hydrogen bonds. The polyhedrons around the K+ cations are rather irregular. However, a specific spatial arrangement of potassium cations is similar in all three crystals.
Scanning Electrochemical Microscopy as a Versatile Tool for Modifying Surfaces
Authors: Radtke Valentin , Heinze Jürgen 
Published: February 2004

Abstract
Micromodification of surfaces is the introduction of well-defined, directly local changes in the chemical or physical properties of such surfaces. This includes etching processes, deposition of materials and chemical modification of the surface material. As a scanning probe technique, the scanning electrochemical microscope (SECM) is predestined to generate chemical changes locally. Our intention is to demonstrate the effect of local chemical changes on a surface. For this purpose, we first recapitulate the work of our group on micromodification and then deal with galvanic deposition of metals, electroless deposition of conducting polymers and the use of etching to introduce organic features onto an inorganic surface.
The Absorption Spectrum of Anisole and the Anisole/CO2 1:1-Cluster. The Influence of Intermolecular Interaction on Intramolecular Vibrations
Authors: Gemechu A. S. , Hoffmann L. J. H. , Marquardt S. , Eisenhardt C. G. , Baumgärtel Helmut , Chelli R. , Cardini G. , Califano S. 
Published: February 2004

Abstract
The S
1(1
B
2) ← S
0(1
A
1) electronic transition of anisole and the anisole/CO2 aggregate cooled in a supersonic free jet has been investigated in detail using REMPI spectroscopy and quantumchemical model calculations. The 42 intramolecular modes of anisole in the 1
S
1 state are assigned. Some previous assignments of modes of anisole in the 1
S
1 state have been improved, some of the assignments are still tentative. The origin of the corresponding electronic transition in the 1:1-aggregate is blueshifted by 117cm−1 versus the 0-0 transition of anisole, the origine in the 1:2-agreggate is redshifted by 216cm−1. Probably a second conformer of the 1:1-aggregate is formed in the molecular beam. 36 fundamental modes of the anisole/CO2 1:1-cluster out of possible 46 intramolecular modes are assigned. Spectral shifts of the fundamental modes in the 1
S
1 state of anisole/CO2 due to the aggregation have been observed. The intermolecular modes and their binary combinations with intramolecular modes have been analyzed.
Kinetic Hydrogen/Deuterium Isotope Effects in Multiple Proton Transfer Reactions
Authors: Limbach Hans-Heinrich , Klein Oliver , Lopez Del Amo Juan Miguel , Elguero Jose 
Published: February 2004

Abstract
In this paper, a description of multiple kinetic isotope effects (MKIE) of degenerate double, triple and quadruple proton transfer reactions in terms of formal kinetics is developped. Both single and multiple barrier processes are considered, corresponding to so-called “concerted” and “stepwise” reaction pathways. Each step is characterized by a rate constant and the transfer of a given H isotopes or ensemble of H isotopes. The MKIE are expanded in terms of kinetic H/D isotope effects P contributed by single sites in which a proton is transferred in the rate limiting steps. By combination with a modified Bell tunneling model the formalism developed can be used in order to take into account tunneling effects of both concerted and stepwise multiple proton transfers at low temperatures.
High Time Resolution Multifrequency EPR of Radical Pair Intermediates in Photosynthetic Reaction Centers: Structure Determination on a Nanosecond Time Scale
Authors: Link G. , Heinen U. , Berthold T. , Ohmes E. , Weidner J.-U. , Kothe G. 
Published: February 2004

Abstract
The primary steps of photosynthesis proceed via light-induced radical pairs as short-lived intermediates. In this paper we discuss novel coherence phenomena which can be observed for these species. It is demonstrated that the analysis of quantum beat oscillations in combination with multifrequency EPR and a magnetically oriented sample represents a powerful structural tool. We expect that this is of general interest, since the detailed structure of radical pair intermediates can be determined on a nanosecond time scale.
Pharmacokinetics of nifedipine in Taiwanese
Authors: Chien Shu‐Chen , Uang Yow‐Shieng , Lin Hsiu‐Yi , Hsu Kuang‐Yang 
Published: February 2004

AbstractTo elucidate the pharmacokinetics of nifedipine in Taiwanese, a retrospective review of nifedipine bioequivalence studies completed in Taiwan in the past 5 years was conducted. A total of 198 healthy male volunteers were given a single dose of a 10 mg Adalat® capsule as a reference drug after overnight fasting. Pharmacokinetic parameters derived from Adalat® administration were calculated by non‐compartmental analysis with the WinNonlin program. After oral administration of an immediate‐release dosage form of a 10 mg nifedipine capsule to Taiwan residents, a skewed distribution with no clear evidence of bimodality of pharmacokinetic parameters was observed. The mean Cmax was 143.12±53.48 ng/ml, the mean AUC was 293.77±115.62 ng·h/ml, the mean T1/2 was 3.08±1.61 h, and the median value of Tmax was 0.61 h. Compared with other published studies, the Cmax and AUC of nifedipine after 10 mg administration were significantly higher in Taiwanese than in British and American subjects. However, the Cmax and AUC were similar to those of Indian and Mexican subjects. According to the antimode of AUC distribution of 22.5 ng·h/ml/mg proposed by Kleinbloesem, 69.7% of Taiwanese can be categorized as slow metabolizers. Based on the results in this study, the majority of Taiwanese show lower activity of nifedipine metabolism. Copyright © 2004 John Wiley & Sons, Ltd.
On the perspectives of capillary electrophoresis modes for the determination of morphine in human plasma without sample pretreatment
Authors: Emara Samy , Darwish Ibrahim , Youssef Diaa , Masujima Tsutomu 
Published: February 2004

AbstractScreening and conﬁrmation of drugs of abuse in body ﬂuids are important for the medicinal treatment and form the legal basis of court judgments. A fast and precise identiﬁcation of toxic substances is necessary. Morphine was determined in human plasma by capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC) using sample stacking mode. The electrophoretic separation was performed in an uncoated fused‐silica capillary, 70 cm long to the detector, with an additional 10 cm to the cathode (75 µm i.d. and 360 µm o.d.). The UV absorbance detection was set at 190 nm. The electrophoretic buffers were prepared from 60 to 300 mm disodium tetraborate decahydrate, pH 10.5. Sodium dodecyl sulfate was added to the ﬁnal solution in a concentration of 60 mm for MECC. All electrophoretic separations were carried out at 10 kV and the capillary temperature was ambient (25°C). A linear calibration graph was obtained in the concentration range studied (50–5000 ng/mL). Several samples of drug‐free plasma were checked for potential endogenous interference and the results showed no interference from the endogenous components, which co‐migrated with morphine. As little as 50 ng/mL of morphine could be successfully analyzed by MECC in the concentration mode with acceptable precision. It is possible to determine morphine directly in plasma at therapeutic concentrations. Copyright © 2003 John Wiley & Sons, Ltd.
Development and validation of a hydrophilic interaction liquid chromatography–tandem mass spectrometric method for the analysis of paroxetine in human plasma
Authors: Naidong Weng , Eerkes Angela 
Published: February 2004

AbstractA sensitive, simple, fast and rugged hydrophilic interaction liquid chromatography–tandem mass spectrometry (HILIC‐MS/MS) method for the determination of paroxetine was developed and validated over curve range 0.050–50 ng/mL using only 0.4 mL plasma. This is the ﬁrst published LC‐MS/MS method and the low limit of quantitation of this method is 10‐fold lower than previously published methods. A simple liquid–liquid extraction method using methyl‐tert butyl ether (MTBE) as the extraction solvent was used to extract paroxetine and the internal standard (IS) fentanyl‐d5 from plasma. The extract was evaporated to dryness, reconstituted and injected onto a silica column using a low aqueous–high organic mobile phase. The chromatographic run time was 2.0 min per injection, with retention times of 1.1 and 1.2 min for paroxetine and IS, respectively. The detection was by monitoring paroxetine at m/z 330 → 192 and IS at m/z 342 → 188, respectively. The inter‐day precision and accuracy of the quality control (QC) samples were <5.0% relative standard deviation (RSD) and <2.9% relative error (RE). This method can be used for supporting therapeutical drug monitoring and pharmacokinetic or drug–drug interaction studies. Copyright © 2003 John Wiley & Sons, Ltd.
High‐performance liquid chromatographic determination of Levetiracetam in human plasma: comparison of different sample clean‐up procedures
Authors: Pucci Vincenzo , Bugamelli Francesca , Mandrioli Roberto , Ferranti Anna , Kenndler Ernst , Raggi Maria Augusta 
Published: February 2004

AbstractAn accurate and precise high‐performance liquid chromatographic method using diode array detection for the determination of the novel antiepileptic, Levetiracetam, has been developed. Three clean‐up procedures for the analysis of Levetiracetam in human plasma were implemented and evaluated, namely solid‐phase extraction, deproteinization by addition of organic solvents and formation of insoluble salts. Adenosine was used as the internal standard for all three sample pretreatment procedures. Among the several cartridges used for solid‐phase extraction, the hydrophilic–lypophilic balance (Oasis® HLB) phase provides the best extraction yield of Levetiracetam, together with high precision. With the two other clean‐up procedures involving plasma deproteinization by addition of methanol or zinc sulphate, lower sensitivity and precision of the assays were obtained. However, they are cheaper and faster when compared with the solid‐phase extraction procedure. Copyright © 2003 John Wiley & Sons, Ltd.
Simultaneous determination of sulfamethoxazole and trimethoprim in human plasma by capillary zone electrophoresis
Authors: Teshima Daisuke , Otsubo Kaori , Makino Kazutaka , Itoh Yoshinori , Oishi Ryozo 
Published: February 2004

AbstractA capillary electrophoretic method for the simultaneous determination of sulfamethoxazole and trimethoprim in plasma was developed. Sulfamethoxazole and trimethoprim extracted from human plasma with ethyl acetate were analyzed at 20 kV and 25°C using 15 mm phosphate buffer (pH 6.2) as the electrolyte. The detection was by UV at 220 nm. The run time was 8.0 min and the limit of quantiﬁcation was 10.00 µg/mL for sulfamethoxazole and 2.00 µg/mL for trimethoprim. The recovery was >99% for both compounds. This method enabled the detection of sulfamethoxazole and trimethoprim in plasma of patients after oral ingestion of their combined formulation. The present simple and rapid method is applicable to drug monitoring in immunocompromised patients who are taking the combined formulation of these compounds for the treatment or prophylaxis of Pneumocystis carinii pneumonia. Copyright © 2004 John Wiley & Sons, Ltd.
An isocratic HPLC method for the quantitation of eicosanoids in human platelets
Authors: Moraes Leonardo A. , Giner Rosa M. , Paul‐Clark Mark J. , Perretti Mauro , Perrett David 
Published: February 2004

AbstractWe describe here a modiﬁed protocol for the simultaneous quantiﬁcation of speciﬁc eicosanoids formed during stimulation of human platelets in vitro with adenosine diphosphate. The eicosanoids thromboxane B2 (TXB2), arachidonic acid (AA), 12‐R‐hydroxyeicosatetraenoic acid (12‐R‐HETE), 12‐S‐hydroxyheptadecatrienoic acid (12‐S‐HHTrE) and the internal standard prostaglandin B1 (PGB1) were extracted from human platelets by liquid–liquid extraction using ethyl acetate. This was followed by derivatization and ﬂuorescent detection prior to analysis by reversed phase liquid chromatography. The highperformance liquid chromatographic method consisted of ODS reversed‐phase column (3 µm) and a mobile phase of acetonitrile–water (85:15). TXB2 and AA plasma calibration curves were linear between 6.25 and 125 ng mL−1 (r2 > 0.997), whereas for 12‐R‐HETE and 12‐S‐HHTrE the curves were linear between 5.0 and 40 ng mL−1 (r2 > 0.998). All calibration curve standards had <15% CV (coefﬁcient of variation) and between‐run precision, and the percentage relative deviation for replicate (n = 6) quality controls was less than 5.5%. The method was adapted to allow the screening of drugs that may affect either one or both of the lipoxygenase and cyclo‐oxygenase pathways. Copyright © 2004 John Wiley & Sons, Ltd.
Quantum mechanical considerations on the algebraic structure of central molecular chirality
Authors: Capozziello Salvatore , Lattanzi Alessandra 
Published: February 2004

AbstractThe chiral algebra of tetrahedral molecules, derived from Fischer's projections, is discussed in the framework of quantum mechanics. A “quantum chiral algebra” is obtained whose operators, acting as rotations or inversions, commute with the Hamiltonian of the system. It is shown that energy and chirality eigenstates are strictly related through the Heisenberg relations, while chirality operators “conserve” parity eigenstates. Chirality 16: 162–167, 2004. © 2004 Wiley‐Liss, Inc.
Multicenter Phase II study of estramustine phosphate plus weekly paclitaxel in patients with androgen‐independent prostate carcinoma
Authors: Vaughn David J. , Brown Archie W. , Harker W. Graydon , Huh Sang , Miller Lance , Rinaldi David , Kabbinavar Fairooz 
Published: February 2004

AbstractBACKGROUNDThe current study determined the efficacy and toxicity of weekly paclitaxel in combination with estramustine phosphate (EMP) in patients with androgen‐independent prostate carcinoma (AIPC).METHODSPatients with progressive AIPC received 90 mg/m2 paclitaxel by 1‐hour intravenous infusion weekly for 3 weeks, followed by a 1‐week treatment rest. Patients received 140 mg EMP orally 3 times daily on the day before, the day of, and the day after paclitaxel administration. Patients received 1 mg warfarin daily to prevent thromboembolism.RESULTSSixty‐six patients with progressive AIPC received treatment at 29 centers. Forty‐two percent of patients had a 50% decline in prostate‐specific antigen (PSA; 95% confidence interval [CI], 30–54%). For 26 patients with bidimensionally measurable disease, the objective response rate was 15% (95% CI, 1–30%). The median time to disease progression was 6.3 months, and the median time to PSA progression was 11.4 months. The median survival period was 15.6 months. Grade 3–4 toxicities were uncommon and included thromboembolism (8%), anemia (3%), neutropenia (3%), and peripheral neuropathy (2%). There was one treatment‐related death.CONCLUSIONSThis regimen of EMP plus weekly paclitaxel was an active and well tolerated treatment for patients with AIPC. Cancer 2004;100:746–50. © 2004 American Cancer Society.
Intensive sequential chemotherapy with hematopoietic growth factor support for non‐Hodgkin lymphoma in patients infected with the human immunodeficiency virus
Authors: Costello Régis T. , Zerazhi Hacène , Charbonnier Aude , de Colella Jean‐Marc Schiano , Alzieu Claude , Poizot‐Martin Isabelle , Cohen Rolande , Bardou Valérie‐Jeanne , Xerri Luc , Olive Daniel , Nezri Meyer , Lepeu Gérard , Gastaut Jean‐Albert 
Published: February 2004

AbstractBACKGROUNDOptimal treatment of human immunodeficiency virus (HIV)‐associated non‐Hodgkin lymphoma (NHL) has yet to be defined, because chemotherapy could exacerbate immunodeficiency, with subsequent adverse effects for patients.METHODSThe authors investigated the feasibility of an intensive chemotherapy regimen for HIV‐associated NHL. Thirty‐eight patients were treated with a first course of cyclophosphamide (Cy), vincristine, and prednisone; followed by 3 courses of high‐dose Cy (2000 mg/m2), doxorubicin (Doxo; 50 mg/m2), vincristine, and prednisone (modified high‐dose CHOP); 1 course of high‐dose methotrexate (MTX; 8000 mg/m2); and 1 course of high‐dose cytarabine (8000 mg/m2). Radiotherapy was added to the treatment regimen for patients with bulky disease or residual tumor. Chemotherapy was administered in conjunction with granulocyte–colony‐stimulating factor and antiretroviral therapy.RESULTSPatients received 91.5%, 93%, 66%, and 63% of the scheduled doses of Cy, Doxo, MTX, and cytarabine, respectively. The complete response rate was 60.5%, with a total response rate of 79%. The 40‐month overall survival rate was 43%, the disease‐free survival rate was 65%, and the recurrence‐free survival rate was 39%. Both an International Prognostic Index score of 0 or 1 and Burkitt‐type histology had positive effects on survival, whereas CD4‐positive lymphocyte counts, viral burden, and previous highly active antiretroviral therapy did not. CD4‐positive T lymphocyte levels decreased from 0.197 ± 0.156 ×109/L before treatment to 0.152 ± 0.1 ×109/L at 6 months after the end of treatment. A decrease in viral load, from 380,000 ± 785,000 copies/mL before treatment to 25,000 ± 43,000 copies/mL at 6 months after the end of treatment, also was observed.CONCLUSIONSThe results of the current study indicate that intensive chemotherapy is effective and tolerable for patients with HIV‐associated NHL. Cancer 2004;100:667–76. © 2004 American Cancer Society.
Effect of breast‐conserving therapy versus radical mastectomy on prognosis for young women with breast carcinoma
Authors: Kroman Niels , Holtveg Helle , Wohlfahrt Jan , Jensen Maj‐Britt , Mouridsen Henning T. , Blichert‐Toft Mogens , Melbye Mads 
Published: February 2004

AbstractBACKGROUNDAmong middle‐aged and older women with early breast carcinoma, breast‐conserving therapy (BCT) has been shown to have an effect on survival that is similar to that of modified radical mastectomy (RM). Nonetheless, it remains to be established whether BCT also is the optimal treatment option for early breast carcinoma in young women, because these women generally have more aggressive disease and a higher frequency of local recurrence compared with older women.METHODSWe investigated a cohort of 9285 premenopausal women with primary breast carcinoma who were age < 50 years at diagnosis. These women were identified from a population‐based Danish breast carcinoma database containing detailed information on patient and tumor characteristics, predetermined treatment regimens, and survival.RESULTSIn total, 7165 patients (77.2%) were treated with RM, and 2120 patients (22.8%) were treated with BCT. We calculated the relative risk of death within the first 10 years after diagnosis according to surgical treatment and age, both before and after adjustment for known prognostic factors. No increased risk of death was observed among women who received BCT compared with women who underwent RM, regardless of age at diagnosis (< 35 years, 35–39 years, 40–44 years, or 45–49 years), despite the increased risk of local recurrence among young women. Restricting the analysis to women with small tumors (size < 2 cm) yielded similar results.CONCLUSIONSDespite having a higher rate of local recurrence, young women with breast carcinoma who receive BCT are similar to young women treated with RM in terms of survival. Cancer 2004;100:688–93. © 2003 American Cancer Society.
Breast carcinoma survival in Europe and the United States
Authors: Sant Milena , Allemani Claudia , Berrino Franco , Coleman Michel P. , Aareleid Tiiu , Chaplain Gilles , Coebergh Jan Willem , Colonna Marc , Crosignani Paolo , Danzon Arlette , Federico Massimo , Gafà Lorenzo , Grosclaude Pascale , Hédelin Guy , Macè‐Lesech Josette , Garcia Carmen Martinez , Møller Henrik , Paci Eugenio , Raverdy Nicole , Tretarre Brigitte , Williams Evelyn M. I. ,   European Concerted Action on Survival and Care of Cancer Patients (EUROCARE) Working Group
Published: February 2004

AbstractBACKGROUNDBreast carcinoma survival rates were found to be higher in the U.S. than in Europe.METHODSMultiple regression analysis of breast carcinoma survival rates among women diagnosed between 1990 and 1992 was performed using clinical data from population‐based case series from the Surveillance, Epidemiogy, and End Results (SEER) program (13,172 women) and the European Concerted Action on survival and Care of Cancer Patients (EUROCARE) project (4478 women).RESULTSEarly‐stage tumors (T1N0M0) were more frequent in the SEER data (41% of cases) than in the EUROCARE data (29%). In the SEER data, early tumors were more frequent in women age ≥ 65 years (43%) than in younger women (38%), whereas the reverse was true in the European data (25% vs. 31%). In both case series, > 90% of women underwent surgery and 81–82% underwent lymphadenectomy, but the number of axillary lymph nodes evaluated was higher in the SEER data than in the EUROCARE data. The 5‐year survival rate was higher in the U.S. case series (89%) than in the European series (79%). This differential was observed for each stage category evaluated: early (T1N0M0), large lymph node‐negative (T2–3N0M0), lymph node‐positive (T1–3N+M0), locally advanced (T4M0), and metastatic (M1) tumors. The overall relative excess risk (RER) of death was significantly higher (RER, 1.37; 95% confidence interval [95% CI], 1.25–1.50) among European women compared with U.S. women (referent group). Adjustment for stage, age, surgery, and the number of lymph nodes evaluated explained most of the excess risk (RER, 1.07; 95% CI, 0.98–1.17).CONCLUSIONSTransatlantic differences in the 5‐year survival rates for women diagnosed with breast carcinoma between 1990 and 1992 were attributable mainly to differences in stage of disease. Resources should be invested to achieve earlier diagnosis of breast carcinoma in Europe, especially for elderly women. Cancer 2004;100:715–22. © 2003 American Cancer Society.