bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of circular waveguides with soft and hard surfaces realized by strip‐loaded walls using asymptotic boundary conditions
Authors: Kishk Ahmed A. , Morgan Michael 
Published: August 2002

AbstractSoft and hard walls are realized for a circular waveguide with walls coated by a uniform dielectric layer of appropriate thickness and loaded with conducting strips. The strips are oriented along the waveguide axis (z‐axis) for hard surfaces or φ‐directed for soft surfaces in a periodic form. The simple approximate asymptotic strip boundary condition (ASBC) is used to analyze the structure. For the dominant mode, when the waveguide walls are hard or soft, a linear field distribution across the waveguide cross section can be obtained. Then the waveguide can be used as an antenna with good linear polarization. The characteristics of such waveguides are presented with sample radiation patterns as compared with hollow waveguide radiation patterns. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 433–436, 2001.
Pulmonary abnormalities at long‐term follow‐up of patients with Langerhans cell histiocytosis
Authors: Bernstrand Cecilia , Cederlund Kerstin , Sandstedt Bengt , Åhström Lars , Lundell Marie , Dahlquist Gisela , Henter Jan‐Inge 
Published: August 2002

AbstractBackgroundIn Langerhans cell histiocytosis (LCH) pulmonary involvement, which is often initially asymptomatic, may contribute to significant morbidity and mortality. To determine the long‐term prognosis, a cross‐sectional study was undertaken.ProcedureForty‐one patients with ≥5 years follow‐up after the diagnosis of LCH were interviewed and underwent physical examination, blood tests, a chest X‐ray and a high‐resolution CT (HRCT) of the lungs. All patients included had been referred to the Department of Pediatrics at the Karolinska Hospital in Stockholm between July 1962 and February 1990 (median follow‐up 16 years). Biopsies from all patients were reviewed and confirmed to be consistent with LCH. Information on previous clinical features including treatment and the results of chest X‐rays were also collected for risk factor analysis.ResultsRadiographic abnormalities of the lungs (cysts and/or emphysema), found in 10/41 (24%) at follow‐up, were classified into five groups according to the extent of the cysts. These patients had more often suffered from multisystem than from single‐system disease (P = 0.01), were significantly older at diagnosis (P < 0.001), and had been more heavily treated with chemotherapy and/or radiotherapy. They were also more frequently smokers (P < 0.0001) and 7/10 (70%) had suffered lung involvement at diagnosis. At the time of diagnosis of the pulmonary involvement, 4/10 (40%) patients had respiratory symptoms, but only 2/10 (20%) had symptoms at follow‐up.ConclusionsTen (24%) of the 41 patients had abnormal findings on radiological examination of the lungs at long‐term follow‐up and seven are or had been smokers. It is of great importance that patients with LCH be informed about smoking‐related pulmonary morbidity. Prolonged monitoring of the lungs for smokers and patients with known pulmonary involvement is recommended. Med. Pediatr. Oncol. 36:459–468, 2001. © 2001 Wiley‐Liss, Inc.
Expression of cytokeratin‐18‐related tissue polypeptide‐specific (TPS) antigen in Wilms tumor
Authors: Rebhandl Winfried , Handisurya Alessandra , Memaran Nima , Felberbauer Franz Xaver , Aberle Judith , Paya Kurosh , Strobl Birgit , Horcher Ernst 
Published: August 2002

AbstractBackgroundSo far, there is no approved tumour marker for diagnosis or follow‐up in Wilms tumour (WT). Tissue polypeptide‐specific antigen (TPS), a cytokeratin 18 proteolytic fragment, has been suggested to be of value in the clinical management of WT patients. Cytokeratin 18 fragments are an early indicator of apoptosis and cytokeratin 18 might influence tumour cell behaviour. We investigated TPS expression in specimens of WT and other paediatric renal malignanciesProcedureImmunoreactivity of WT sections (n = 9), clear cell sarcomas (CCSK, n = 3), and a renal cell carcinoma (RCC), and two pediatric kidney tumour cell lines (WT: SK‐NEP‐1 and rhabdoid tumour of the kidney: G‐401) were investigated using the monoclonal antibody M3. Additionally, immunoblotting and RT‐PCR analysis were performed. Cell culture supernatants were evaluated for TPS release. Serum TPS was measured in five patients at diagnosis, during chemotherapy and after surgical resection.ResultsModerate to strong immunoreactivity for TPS was found in tubular and blastemal components of nearly all (8/9) WT specimens. This was confirmed by Western‐blotting. Cystic and epithelial‐like portions of CCSKs and RCC showed distinct reactivity (3/3). The supernatant of G‐401 but not of SK‐NEP‐1 showed a time‐ and cell number‐dependent increase of TPS release. Interestingly, TPS synthesis was demonstrated in SK‐NEP‐1 cells. Median preoperative serum TPS was elevated (293 U/l) compared to healthy children and lowest after surgical resection (49.5 U/l).ConclusionsThis is the first study demonstrating the synthesis and release of TPS by WTs and other paediatric renal malignancies. Considering the elevated levels of TPS in serum of these patients, a further investigation of this marker by larger clinical trials seems to be justified. Med Pediatr Oncol 2001;37:357–364. © 2001 Wiley‐Liss, Inc.
Intensive timed sequential remission induction chemotherapy with high‐dose cytarabine for childhood acute myeloid leukemia
Authors: Loeb David M. , Bowers Daniel C. , Civin Curt I. , Friedman Alan D. 
Published: August 2002

AbstractBackgroundTimed sequential chemotherapy and high‐dose cytarabine (cytosine arabinoside, Ara‐C; HDAC) are both effective treatments for acute myeloid leukemia (AML). We review our institutional experience with timed sequential induction chemotherapy consisting of daunorubicin/Ara‐C/‐thioguanine (DAT) or idarubicin/Ara‐C/‐thioguanine (IAT) followed on day 14 by HDAC regardless of the degree of marrow aplasia for children with newly diagnosed AML.ProcedureChildren presenting with newly diagnosed AML were treated with induction chemotherapy consisting of idarubicin (12 mg/m/day on days 1–3 or daunorubicin at 45 mg/m2/day for the first five patients), Ara‐C (100 mg/m2/day by continuous infusion on days 1–7), and thioguanine (100 mg/m2/day on days 1–7). HDAC (1 g/m2/dose every 12 hr for 10 doses) was administered beginning on day 14, regardless of the results of bone marrow examination.ResultsThirteen children received timed sequential HDAC. Only one child received HDAC later than Day 18. Eleven of the children achieved a complete remission. All patients experienced grade 4 hematologic toxicity, and all had fever as well. There were 11 children with documented infections. Ten had grade 3 or 4 GI toxicity. One patient died of sepsis.ConclusionsHDAC administered as a part of timed sequential therapy yields an excellent remission induction rate with manageable toxicity. Med Pediatr Oncol 2001;37:365–371. © 2001 Wiley‐Liss, Inc.
37Cl/35Cl and 13C/12C isotope effects on the fluorine shielding in several two‐carbon chlorofluorocarbons
Authors: Tordeux Marc , Wakselman Claude , Jarjayes Olivier , Béguin Claude G. 
Published: August 2002

AbstractIsotope effects on the chemical shift (IECS) of 19F bonded through two or three bonds to the isotopes 35Cl and 37Cl are reported for a wide range of two‐carbon chlorofluorocarbons (and, for a few cases, with the isotopes 79Br and 81Br, for two‐carbon bromofluorocarbons). These IECS through two bonds were found to range, for one chlorine atom, from −5.0 to −7.6 ppb for aliphatic compounds and from −4.5 to −6.4 ppb for olefinic compounds. The IECS through three bonds were found to be less than −1.15 ppb. No deviation from additivity was detected for the IECS when several equivalent chlorine atoms are present. The broadening of the 19F lines, due to scalar relaxation arising from 19F–37&#38;sol;35Cl spin–spin interactions, ranges from 0.32 to 2.50 Hz in our series and are related to the 2J(Cl, 19F)T1(Cl) term. IECS of 19F bonded through one or two bonds to the isotopes 13C and 12C are also reported for the same series. Several correlations, related to structural information, can be made and discussed between these IECS [13&#38;sol;12C IECS through two bonds as a function of 1J(13C, 19F) spin–spin coupling constants and 13&#38;sol;12C IECS as a function of 37&#38;sol;35Cl IECS]. 37&#38;sol;35Cl IECS can also be observed on 13C satellites of 19F spectra. For non‐symmetrical compounds, the dependence of these signals on the 37&#38;sol;35Cl IECS is the same as that for the main 19F signal; however, for the centrosymmetrical compounds, the main 19F signal appears to be sensitive to all the chlorine atoms, whereas the 13C satellites seem to be sensitive only to the directly bonded chlorine. Copyright © 2001 John Wiley & Sons, Ltd.
Gradient‐enhanced 1D HMQC‐ and HSQC‐relayed experiments with maximum sensitivity
Authors: Parella Teodor , Belloc Jordi 
Published: August 2002

AbstractThe incorporation of pulsed‐field gradients for coherence selection into 1D proton‐detected pulse sequences provides clean spectra free of cancellation artifacts but, frequently, at the expense of a sensitivity loss by a theoretical factor of 2 due to the rejection of another contributed pathway. A series of slightly modified gradient‐enhanced 1D carbon‐selective HMQC‐ and HSQC‐relayed experiments are proposed to obtain maximum signal‐to‐noise ratios in the same overall acquisition time. In contrast to the implementation of this so‐called PEP approach in multi‐dimensional experiments, the proposed 1D experiments do not have extra requirements for data acquisition or data processing with respect to the original ones and the excellent spectral quality due to of gradient‐selected experiments is preserved. Copyright © 2001 John Wiley & Sons, Ltd.
Principal component analysis in studies of substituent‐induced chemical shifts of 1,4‐disubstituted benzenes
Authors: Canto Eduardo L. , Tasic Ljubica , Bruns Roy E. , Rittner Roberto 
Published: August 2002

AbstractChemometric analyses of 1,4‐disubstituted benzene aromatic carbon atom NMR chemical shifts, bearing 14 substituents (X) within a complete series involving the same substituents as fixed groups (Y), are reported. The substituent effects of (i) strong electron donors (NMe2, NH2 and OMe), (ii) halogens (F, Cl and Br), (iii) electron acceptors (CF3, CN and NO2), (iv) acceptors of the carbonyl type [C(O)OEt, C(O)Me and CHO] and (v) neutral groups (H and Me) were studied using principal component analysis (PCA). The charge alterations (Δq) induced by introducing a substituent X at C‐1 were also analyzed by the means of PCA of data obtained from theoretical calculations (AM1 method). The correlations among the substituent chemical shifts (SCS) and among the charge alterations (Δq) and the dependence of SCS on charge alterations were analyzed by regression analyses applied to the scores of the first principal components (PC1) obtained in the PCA of the SCS and Δq values. Copyright © 2001 John Wiley & Sons, Ltd.
Electronic structure of nitrogen–chlorine bonds in some compounds studied by NQR spectroscopy and DFT calculations
Authors: Poleshchuk O. Kh. , Makiej K. , Ostafin M. , Nogaj B. 
Published: August 2002

Abstract35Cl‐NQR frequencies of 1,3,5‐trichloro‐1,3,5‐triazine‐2,4,6‐(1H,3H,5H)‐trione and 1,3‐dichloro‐5,5‐dimethylhydantoin were measured at 77 K. The asymmetry parameters of electric field gradient (EFG) tensors on 35Cl nuclei were also determined with nutation 35Cl‐NQR spectroscopy in zero magnetic field. The calculated quadrupole coupling constants and asymmetry parameters for 14N and 35Cl nuclei were compared with the corresponding experimental values for several compounds containing N—Cl bonds. The electronic structure of the N—Cl bond in these compounds is discussed in terms of the terminology of lone pairs, hybrid orbitals and NAO charges. Copyright © 2001 John Wiley & Sons, Ltd.
Unnaturally configured 13‐epi steroids: full 1H and 13C assignments and ring C–D conformations from 1H, 1H vicinal couplings
Authors: Fielding Lee , Diepeveen Yolande , Fletcher Dan , Hamilton Niall 
Published: August 2002

AbstractSix steroids with inverted stereochemistry at C‐13 (13‐epi) were studied. Measurement of vicinal proton–proton couplings was facilitated by a 1D TOCSY experiment, which provided efficient deconvolution of the ring D protons from other signals. A simple semi‐quantitative analysis of the ring D couplings was found to be sufficient to determine the conformation of ring D. Examples of 13α, 14β half‐chair, 17β envelope and 16β envelope conformations were found. Copyright © 2001 John Wiley & Sons, Ltd.
Translactonization of erythromycin A during oximation: mixture analysis and reaction monitoring by NMR
Authors: Grover Rajesh K. , Joshi B. S. , Batra S. , Roy Raja , Bhaduri A. P. 
Published: August 2002

AbstractOximation of erythromycin A with hydroxylamine hydrochloride and sodium acetate in methanol led to the formation of pseudoerythromycin A enol ether with erythromycin A oxime as analysed by detailed two‐dimensional NMR spectroscopy in the mixture along with traces of 8,9‐anhydroerythromycin A 6,9‐hemiketal and erythromycin A 6,9:9,12‐spiroketal. The formation of the degraded products was established by performing in situ 13C NMR spectroscopy. The analysis suggests that pseudoerythromycin A enol ether is formed by the translactonization of erythromycin A enol ether which forms as a result of acid degradation. Copyright © 2001 John Wiley & Sons, Ltd.
Unambiguous signal assignments of 1H and 13C NMR spectra for chlorinated benzenes using 37Cl/35Cl isotope effects
Authors: Matsubara Koshi 
Published: August 2002

AbstractOne‐bond 37Cl/35Cl isotope effects on 13C NMR chemical shifts were used to assign the 1H and 13C NMR spectra of bis(4‐chlorophenyl)sulfone, 4,5‐dichlorophthalic acid and 2,2′‐thiobis(4,6‐dichlorophenol). The chlorine‐bonded carbons showed characteristic peaks separated by about 4 ppb with a 3 : 1 area ratio, corresponding to the natural abundance of 35Cl and 37Cl. The determination of the chlorine‐bonded carbon signals based on the isotope effects was useful when the empirical additivity rules of the chemical shifts and several 2D NMR techniques were insufficient for a complete definitive assignment. Copyright © 2001 John Wiley & Sons, Ltd.
Structure determination of daphjamilin, a new bicoumarin glycoside, by NMR spectroscopy
Authors: Riaz Muhammad , Malik Abdul 
Published: August 2002

AbstractDaphjamilin, a new dimeric coumarin glycoside, was isolated from the roots of Daphne oleoides and assigned the structure 7‐O‐α‐L‐rhamnosyl‐8‐[2‐oxo‐2H‐1‐benzopyran‐7′‐(hydroxy)‐6′‐yl]‐2H‐1‐benzopyran‐2‐one by extensive NMR studies. Copyright © 2001 John Wiley & Sons, Ltd.
Cycle time as a variable in homonuclear decoupling in solids: use of CRAMPS to determine minor constituent impurities in organic crystals to ≤0.005%
Authors: Gerstein Bernard C. , Kimura Hideaki 
Published: August 2002

AbstractThe use of proton CRAMPS NMR with varying cycle time and gain is shown to avoid the problems of dynamic range and probe background, and to allow residual solvent in some organic crystals such as durene to determined with an accuracy of ≤0.005%. Copyright © 2001 John Wiley & Sons, Ltd.
Diastereoselective synthesis and 1H and 13C NMR study of 4‐acetyl‐2,6‐diaroyl‐3,5‐diaryl‐4‐ethoxycarbonylthiane‐1,1‐dioxides
Authors: Renuga S. , Selvaraj S. , Perumal S. , Lycka A. , Gnanadeebam M. 
Published: August 2002

AbstractConjugate addition of ethyl acetoacetate to 2,2′‐sulfonylbis(1,3‐diarylprop‐2‐en‐1‐ones) afforded a diastereom‐eric mixture (in a ratio of ∼65:35) of 4‐acetyl‐2,6‐diaroyl‐3,5‐diaryl‐4‐ethoxycarbonylthiane‐1,1‐dioxides differing in configuration at C‐4. The stereochemistry of the diastereomeric thianes was established by 1H, 13C and 2D NMR spectroscopic techniques such as H,H‐COSY, C,H‐COSY and NOESY. Copyright © 2001 John Wiley & Sons, Ltd.
Structure elucidation of three new acetylated flavonoid glycosides from Centaurium spicatum
Authors: Shahat Abdelaaty A. , Apers Sandra , Miert Sabine Van , Claeys Magda , Pieters Luc , Vlietinck Arnold 
Published: August 2002

AbstractThree new acetylated flavonol glycosides, quercetin 3‐O‐(2,3,4‐triacetyl‐α‐rhamnopyranosyl)‐(1 → 6)‐β‐galactopyranoside, quercetin 3‐O‐[(2,3,4‐triacetyl‐α‐rhamnopyranosyl)‐(1 → 6)]‐3‐acetyl‐β‐galactopyranoside and quercetin 3‐O‐[(2,3,4‐triacetyl‐α‐rhamnopyranosyl)‐(1 → 6)]‐4‐acetyl‐β‐galactopyranoside, were isolated from Centaurium spicatum (L.) Fritsch (Gentianaceae). Structure elucidation, especially the localization of the acetyl groups, and complete 1H and 13C NMR assignments of these biologically active compounds were carried out using one‐ and two‐dimensional NMR methods, including 1H and 13C NMR, DEPT‐135 and DEPT‐90 and gradient‐assisted experiments such as DQF‐COSY, TOCSY, HSQC and HMBC experiments. Copyright © 2001 John Wiley & Sons, Ltd.
Stereochemical and conformational studies on pharmaceutical compounds by NMR and molecular modelling
Authors: Sharman Gary J. , Jones Ian C. 
Published: August 2002

AbstractNMR and molecular modelling were used to determine the stereochemistry of two pairs of pharmaceutical compounds. In both cases, an unexpected conformation complicated the analysis of one isomer, but the insight provided by molecular modelling allowed the NMR data to be interpreted and the identity proved. This study highlights the difficulty of predicting conformation, even for what might be expected to be straightforward systems. Copyright © 2001 John Wiley & Sons, Ltd.
Dipole‐stabilized carbanions in series of cyclic aldonitrones: Part 4. 13C, 14N and 7Li NMR spectra of dipole‐stabilized organolithiums derived from a cyclic aldonitrone
Authors: Voinov Maxim A. , Salnikov Georgy E. , Genaev Alexander M. , Mamatyuk Victor I. , Shakirov Makhmut M. , Grigor'ev Igor A. 
Published: August 2002

Abstract13C, 14N and 7Li NMR spectra of a lithiation product of the cyclic aldonitrone 1,2,2,5,5‐pentamethyl‐3‐imidazoline 3‐oxide were obtained. The 13C NMR spectrum of the lithiated particle exhibits the resonances of the C‐4 and C‐5 atoms (δ213 ppm and 73 ppm, respectively) shifted to high frequency relative to the signals of the corresponding nuclei of the starting nitrone (δC‐4 132 ppm and δC‐5 60 ppm). The 14N NMR spectrum of the particle shows the resonance of the N‐3 atom (−115 ppm) at lower frequency in comparison with −74 ppm for the starting nitrone. The calculated chemical shift changes are in good agreement with those observed experimentally. The electronic structure of the lithiated particle is discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Complete 1H and 13C resonance assignments of glycosidic conjugates of non‐amidated and amidated bile acids
Authors: Iida Takashi , Kasuga Yuka , Arakawa Masayuki , Mushiake Kumiko , Ikegawa Shigeo , Goto Junichi , Nambara Toshio 
Published: August 2002

AbstractComplete 1H and 13C resonance assignments on the basis of 1D and 2D NMR were made for seven naturally occurring variants of the 3α‐, 6α‐ and 7β‐O‐β‐D‐glycosidic conjugates (glucosides, N‐acetylglucosaminides and glucuronides) of non‐amidated and glycine‐ and taurine‐amidated bile acids related to lithocholic, hyodeoxycholic, chenodeoxycholic, ursodeoxycolic, deoxycholic and cholic acids. The 1H and 13C NMR signals serving to characterize each of the glycosidic conjugates of bile acids and the effects of the O‐β‐D‐glucosidation, O‐β‐D‐N‐acetylglucosaminidation and O‐β‐D‐glucuronidation at the 3‐, 6‐ or 7‐position in the 5β‐steroid nucleus on the 1H and 13C resonances were clarified and used in the structural elucidation of these bile acid glycosides. Copyright © 2001 John Wiley & Sons, Ltd.
Temperature calibration of a high‐resolution magic‐angle spinning NMR probe for analysis of tissue samples
Authors: Nicholls Andrew W. , Mortishire‐Smith Russell J. 
Published: August 2002

AbstractThe increase in tissue sample temperature caused by the spinning of a rotor in high‐resolution magic‐angle spinning (HRMAS) NMR spectroscopy was investigated using two literature NMR thermometers. The classical methanol thermometer was used to calibrate the temperature difference between the set temperature and the actual sample temperature. At spin speeds of 2, 4, 6 and 8 kHz, a mean increase in sample temperature over the set temperature of 0.8 ± 0.1, 2.2 ± 0.1, 5.0 ± 0.1 and 7.9 ± 0.2 K, respectively, was noted. This calibration was used to gauge the accuracy of the literature glucose thermometer, which was shown to have a mean increase over the set temperature of −0.3 ± 0.1, 1.2 ± 0.2, 3.0 ± 0.2 and 6.1 ±0.1 K at 2, 4, 6 and 8 kHz, respectively. By correcting for the errors measured in this study, a more accurate determination and adjustment of sample temperature in HRMAS NMR spectroscopic analyses of intact tissues is now possible. Copyright © 2001 John Wiley & Sons, Ltd.
Identification and complete 1H and 13C spectral assignments for the triterpene fern‐9(11)‐en‐28‐oic acid
Authors: Reynolds William F. , McLean Stewart , Burke Sharon J. , Jacobs Helen 
Published: August 2002

AbstractThe structure of the triterpene fern‐9(11)‐en‐28‐oic acid (1), was determined by concerted application of 2D methods, which also provided full 1H and 13C spectral assignments. Compound 1 is a rare triterpene which has been isolated once before, as its methyl ester. Earlier errors in 13C spectral assignments are corrected. Copyright © 2001 John Wiley & Sons, Ltd.
Essential role of ZP molecules in tubal transport of embryos in mice
Authors: Kim Chang Hun , Seo Byoung Boo , Yamanouchi Keitaro , Kuromaru Masamich , Sawasaki Toru , Hinsch Elvira , Hinsch Klaus‐Dieter , Naito Kunihiko , Tachi Chikashi , Tojo Hideaki 
Published: August 2002

AbstractOur understandings of the molecular and cellular mechanisms underlying tubal transport of embryos are poor. This study describes the essential role of the molecules on the zona pellucida (ZP) in the tubal transport of mouse embryos. The bovine and porcine embryos that were interspecifically transferred to the mouse oviduct were selectively retained in the oviduct and rarely transported to the uterus. Antiserum ZP3‐9 against synthetic peptides that are specific for mouse ZP3, significantly interfered with tubal transport of the treated embryos. The treatment of mouse embryos with antiserum ZP2‐20 against the synthetic peptides, deduced from the sequences that are conserved in the structure of ZP2 from mouse and human, also inhibited their tubal transport. Among various proteolytic and glycosidic enzymes, treatments with trypsin and β‐glucosidase prior to transfer to the oviduct, significantly interfered with the tubal transport of the enzyme‐treated mouse embryos. We hypothesize that species‐specific epitopes on the ZP may be recognized by the oviductal cilia and/or the epithelial cells of ducts for tubal transport. Mol. Reprod. Dev. 61: 327–334, 2002. © 2002 Wiley‐Liss, Inc.