bluuebunny/crossref_metadata_2025 huggingface dataset:
United Kingdom and Ireland precipitation variability and the North Atlantic sea‐level pressure field
Authors: Murphy Sarah J. , Washington Richard
Published: August 2002

The relationship between UK and Ireland (UK&I) precipitation variability and the North Atlantic sea‐level pressure (SLP) field is examined. Strong positive correlations between the North Atlantic Oscillation (NAO) and precipitation in the northwest of the UK&I, particularly in winter, are confirmed but correlations are insignificant at the 0.05 level in the southeast during all months. This paper identifies new patterns of SLP associated with precipitation variability both for regions and months where precipitation variability is not strongly linked with the NAO and for patterns that appear to be more closely related to UK&I precipitation than the NAO.

Two indices of monthly UK&I precipitation variability are calculated using empirical orthogonal functions (EOFs) of monthly UK&I precipitation anomalies. EOF1 represents precipitation variability for the UK&I as a whole and EOF2 the variability in the north–south precipitation gradient across the UK&I. Correlations between both these monthly EOF derived precipitation indices and SLP show a north–south (sub‐tropical/mid‐latitude) dipole, which is particularly strong in winter. These correlation patterns are then used to construct new SLP indices, which necessarily relate more closely to UK&I precipitation. The first index resembles the East Atlantic pattern from September to April. The second may be thought of as an alternative index of the NAO, such that it is optimized with respect to precipitation variability and is located northeast of those centres of action most commonly used to calculate the NAO index.

Stepwise linear regression models, incorporating the two new indices and the original NAOI, suggest that over 25% of UK&I precipitation variability this century (1900–1994) in each month can be explained by a simple index representation of the North Atlantic SLP field. This rises to over 40% of variance explained in nearly all regions of the UK&I. Copyright © 2001 Royal Meteorological Society
A comparison of methods to determine the onset of the growing season in northern Nigeria
Authors: Ati O. F. , Stigter C. J. , Oladipo E. O.
Published: August 2002

In the sudan savanna of northern Nigeria, with its semi‐arid climate, the ability to determine effectively or predict the start of actual productive rains cannot be overemphasized. Several methods exist for calculating the date of onset of the rains that may be taken as the start of the growing season. Five methods currently in use, which are relatively easy to apply on a large scale, were selected for comparison. One is a traditional technique (Ramadan method), two use accumulated rainfall totals (Walter's and Sivakumar's methods), and two use rainfall–evapotranspiration relationships (Kowal's and Benoit's methods). For the period 1961–91, the traditional technique performed most poorly. Walter's method gave quite early onsets and Sivakumar's method gave very late onsets, thereby seriously shortening the growing season. Kowal's and Benoit's determinations fell most often in between the results of Walter's and Sivakumar's methods in their performance. However, although generally to a lesser extent than the other methods, they are still significantly affected by false starts. To avoid incorrectly predicting the growing season's onset as far as possible, but to prevent an unacceptable shortening of the growing season, a combination of Kowal's and Sivakumar's criteria was used to develop an improved technique. This proved to work well for determining the onset date in the study area. However, because some false starts remain when using average onset dates, it is suggested that an operational advisory team should be constituted by the government. This team would be responsible for calculating onset dates in any year, on‐line for the ongoing season, in a participatory approach with farmers, and for disseminating such dates to the farmers. This could be done for any place for which the appropriate data can be made available. In the future, improved climate prediction skill may replace the classical probabilistic approaches presently suffering from increasing rainfall variabilities. Copyright © 2002 Royal Meteorological Society.
Changes in extreme high waters at Liverpool since 1768
Authors: Woodworth Philip L. , Blackman David L.
Published: August 2002

Changes in values of annual maximum high water (AMxHW), annual maximum surge‐at‐high‐water (AMxSHW) and surge at annual maximum high water (SAMxHW) have been investigated using tide gauge data from Liverpool for the period 1768–1999. AMxHW and SAMxHW (measured with respect to mean high water) were found to vary considerably from year to year, but to exhibit no long‐term change over the 232 years. On the other hand, values of AMxSHW were found to be larger in the late‐18th, late‐19th and late‐20th centuries than for most of the 20th century, qualitatively consistent with knowledge of temporal variations in storminess in the region based on meteorological data and anecdotal information. The generalized extreme value method was used to present the available data on AMxHW and other annual extreme parameters in the ‘return period’ form most often employed by coastal engineers, with conclusions on the differences between each set of parameters in each epoch consistent with those obtained from the original time series. Finally, changes in the statistical distribution of surge‐at‐high‐water (SHW), demonstrated by investigation of variations of percentile levels of SHW values, provided additional information on the temporal variations in extreme surges to that provided by AMxSHW values, pointing in particular to increased storminess during the late‐18th and late‐20th centuries, with a suggested secular trend in distribution shape from the late‐18th century until recent decades. Copyright © 2002 Royal Meteorological Society.
Current status of phthalocyanines in the photodynamic therapy of cancer
Authors: ALLEN CYNTHIA M. , SHARMAN WESLEY M. , VAN LIER JOHAN E.
Published: August 2002

Photodynamic therapy is a binary treatment now accepted in clinic for various malignancies in several countries around the world. Phthalocyanine molecules are second-generation photosensitizers with enhanced photophysical and photochemical properties over those of porphyrins. They have been shown to be phototoxic against a number of cell types and tumor models. A great deal of research has been devoted to the elucidation of their mechanism of action and mode of cell death. The present paper reviews phthalocyanine pre-clinical anti-cancer research with emphasis on phthalocyanine induced apoptosis using a silicon phthalocyanine, Pc 4. A brief summary of the latest clinical results using phthalocyanines is presented.
An LDI-TOF and ESI mass spectrometry study of a series of β-substituted cationic metalloporphyrins
Authors: KACHADOURIAN R. , SRINIVASAN N. , HANEY C. A. , STEVENS R. D.
Published: August 2002

A series of β-halogenated cationic metalloporphyrins were analyzed by LDI-TOF and ESI-MS. Although LDI-TOFMS reveals to be a good tool for the characterization of this family of metal-complexes, including the redox state of the metal, ESI-MS indicates in addition the relative tendency of such metal-complexes to be reduced.
Effects of noise on parameter recovery from Raman spectrograms
Authors: Dawlaty Jahan Mansoor , Ulness Darin J.
Published: August 2002

Noisy light‐based Raman spectrograms are simulated to model a single Raman‐active mode with known spectroscopic parameters. Gaussian white noise is added to the spectrograms to mimic experimental data. Two‐dimensional slices of the χ2 surface for the simulated noisy spectrograms are calculated. From the minima of a number of these surfaces, the precision of the recovered spectroscopic parameters from simulated experimental data is obtained. Three different studies dealing with various aspects of the effects of noise on the recovered parameters are presented. The advantage of noisy light‐based Raman spectrograms in yielding exquisite precision, as suggested by previous work, is verified. Furthermore, the advantage of Raman spectrograms in yielding good precision even for poor signal‐to‐noise levels is quantified. Copyright © 2001 John Wiley & Sons, Ltd.
Raman scattering studies of the ZnSe/GaAs interface
Authors: Zhang X. B. , Tsoi H. L. , Ha K. L. , Hark S. K.
Published: August 2002

Raman spectroscopy was used to study the band bending at the interface of ZnSe/GaAs hetero‐structures. A series of samples, which contained a ZnSe buffer layer, 0–35 nm thick, grown at a lower temperature than the much thicker ZnSe epilayer, by metal–organic chemical vapor phase deposition, were investigated. Compared with that of the GaAs substrate, an enhancement of the intensity of the LOGaAs phonon was found in samples grown without and with a thick (≥28 nm) buffer layer, but not in a sample grown with a 4 nm thick buffer layer. The enhancement is attributed to the electric field induced Raman scattering, resulted from a strong band bending on the GaAs side of the hetero‐structure. The results suggest that the direction of the interfacial electric field on the GaAs side will reverse with increasing buffer layer thickness. Between this reversal, a near flat band condition can be achieved, as was found in a sample grown with a 4 nm buffer layer. This suggestion is consistent with the concomitant improvement of the structure of the epilayer and of the interfacial quality of the hetero‐junction, which unpins the Fermi level and affects the band bending. Copyright © 2001 John Wiley & Sons, Ltd.
Differentiation of mono‐oxo and polyoxo and of monomeric and polymeric vanadate, molybdate and tungstate species in metal oxide catalysts by IR and Raman spectroscopy
Authors: Busca Guido
Published: August 2002

The expected and experimental features of vanadate, molybdate and tungstate species observed in inorganic compounds of different structures are discussed. In particular, fourfold coordinated species (truly tetrahedral and distorted tetrahedral), isolated and polymeric mono‐oxo and dioxo metallyl species are discussed. On these bases, some of the data concerning surface species in oxide‐supported oxides are also considered. The need to perform both IR and Raman experiments and, if possible, 18O/16O exchange experiments is also emphasized. Copyright © 2002 John Wiley & Sons, Ltd.
Brave new (paradoxical) world: structure and improvisation in virtual teams
Authors: da Cunha João Vieira , e Cunha Miguel Pina
Published: August 2002

Global virtual teams require a different approach to management that brings together apparent opposites.

This approach is based on three principles that are more like a recipe than a blueprint.

Principle 1: Plan to remain flexible.

Principle 2: Rely on structure to promote initiative.

Principle 3: Use pressure to boost creativity.

These three principles have a broader implication. Most paradoxes in management can be integrated into syntheses.
Tumor p16M is a possible marker of advanced stage in non–small cell lung cancer
Authors: Ng Calvin S.H. , Zhang Jun , Wan Song , Lee Tak Wai , Arifi Ahmed A. , Mok Tony , Lo Dennis Y.M. , Yim Anthony P.C.
Published: August 2002

Background and Objectives

The inactivation of the tumor suppressor gene p16 by methylation (p16M) has been recognized recently as an important process in the oncogenesis for a variety of carcinomas. There have been few reports of its use in lung cancer. We investigate p16M in patients with non–small cell lung cancer (NSCLC).

Methods

p16M in tumor, plasma, and pleural lavage fluid from patients with resectable NSCLC were investigated by using methylation‐specific polymerase chain reaction.

Results

Of the 33 patients studied, 14 (42%) had p16M tumors. There was a significant association between p16M tumors and advanced TNM staging (stage III or IV, P = 0.047, Fisher exact test). Circulating p16M was identified in 2 of the 14 patients with p16M tumor and was also associated with advanced TNM staging (P = 0.049). The presence of plasma p16M in NSCLC patients and in p16M tumor patients was associated with poor survival and shorter disease‐free survival (P = 0.0028, P = 0.0039, Kaplan‐Meier log rank). In addition, p16M was present in three preresectional and four postresectional lavage samples. Preresectional p16M was associated with poor survival and shorter disease‐free survival (P = 0.0085). p16M tumor involving the visceral pleura was significantly associated with positive p16M postresectional lavage.

Conclusions

Positive tumor and plasma p16M indicate advanced staging in NSCLC. Patients with plasma and preresection pleural lavage p16M have shorter survival. Further research in this direction is warranted. J. Surg. Oncol. 2002;79:101–106. © 2002 Wiley‐Liss, Inc.
Accuracy of sentinel node biopsy in predicting nodal status in patients with breast carcinoma
Authors: Sabel Michael S. , Zhang Paul , Barnwell John M. , Winston Janet S. , Hurd Thelma C. , Edge Stephen B.
Published: August 2002

Background and Objectives

While sentinel lymph node biopsy is considered by many to have replaced axillary node dissection in the management of breast cancer, concerns remain regarding false‐negative results.

Methods

To investigate the accuracy of sentinel node biopsy, we reexamined all sentinel and nonsentinel nodes with multilevel sectioning and immunohistochemical staining in 42 consecutive cases of breast cancer in which sentinel node biopsy was performed and followed by axillary dissection.

Results

By routine hematoxylin and eosin (H&E) staining, 34% of patients were found to be node positive, with no cases of false‐negative sentinel node biopsy. Reevaluation of 775 negative sentinel and nonsentinel nodes with an additional two levels and immunohistochemistry identified three “node‐negative” patients who had micrometastases in the sentinel node, increasing detection in 8% of cases. More important, is the fact however, that there were no cases where additional sections and immunohistochemistry identified metastases in nonsentinel nodes that had bypassed the sentinel node. The accuracy of the sentinel node in predicting the nodal status was 100%.

Conclusions

Cytokeratin immunohistochemistry will identify more patients with nodal micrometastases; however, it was unable to identify any cases where micrometastases were present in nonsentinel nodes when the sentinel node was negative. The status of the sentinel node accurately identifies the status of the axillary basin. J. Surg. Oncol. 2001;77:243–246. © 2001 Wiley‐Liss, Inc.
Endovascular photodynamic therapy using mono‐L‐aspartyl‐chlorin e6 to inhibit Intimal hyperplasia in balloon‐injured rabbit arteries
Authors: Nagae Tsuneyuki , Aizawa Katsuo , Uchimura Norio , Tani Daisuke , Abe Mitsuhiro , Fujishima Kazuyuki , Wilson Samuel E. , Ishimaru Shin
Published: August 2002

Background and Objective

Intimal hyperplasia (IH) leading to restenosis is a major complication of arterial revascularization. The purpose of this study was to investigate the effect of photodynamic therapy (PDT) using mono‐L‐aspartyl chlorin e6 (NPe6) as a photosensitizer and intraluminal radial irradiation for inhibition of IH experimentally.

Study Design/Materials and Methods

Study of laser transmission through the blood indicated that exclusion of blood is a prerequisite for intraluminal PDT. For homogeneous radial laser irradiation to the vessel wall, we used a newly developed cylindrical diffusing balloon laser fiber. Injuries were induced by pulling a balloon catheter through the right iliac artery of rabbits. One and 6 hours after the NPe6 injection (5mg/kg i.v.), drug distribution was examined by fluorescence microscopy. Nineteen rabbits received NPe6 at the time of injuries and PDT was performed with 664‐nm laser at 30 and 10 J/cm2 (20, 30, 40 mW/cm2) 1 hour after the injuries. The arteries were harvested at 2 days. In a second group of rabbits, PDT was given at 30 mW/cm2 (30 J/cm2). Two weeks after treatment, the arteries were removed and examined histologically.

Results

NPe6 was found to be distributed selectively in the injured media. Endovascular NPe6‐PDT showed complete depletion of smooth muscle cells even with 10 J/cm2 at 2 days. IH was significantly inhibited at 14 days after PDT.

Conclusions

Endovascular PDT of injured artery using NPe6 can prevent IH in this model of arterial wall injury and may become clinically useful for the prophylaxis of IH. Lasers Surg. Med. 28:381–388, 2001. © 2001 Wiley‐Liss, Inc.
Concentrated autologous plasma protein: A biochemically neutral solder for tissue welding
Authors: Stewart Robert B. , Bleustein Clifford B. , Petratos Peter B. , Chin Katherine C. , Poppas Dix P. , Kung Robert T.V.
Published: August 2002

Background and Objective

Xenographic or allographic serum protein solders used for laser welding may have immunologic and/or pathogenic complications. The objective of these studies was to develop a safe, autologous solder.

Study Design/Materials and Methods

Five methods of preparing concentrated autologous plasma protein solder (CAPPS) were evaluated. Next, the CAPPS was evaluated via (1) thermal denaturation studies using differential scanning calorimetry, (2) tissue welding studies to characterize both acute and healing properties.

Results

The optimal concentration method to produce CAPPS rapidly was a dialysis method using chemical (osmotic) forces. The CAPPS showed similar denaturation profiles to serum albumin (SA) solders. Acutely, CAPPS provided comparable breaking strengths to SA solders. At 7 days, there was no significant difference in breaking strength or histology between 50% human SA solder and CAPPS (using a porcine skin model).

Conclusions

These studies demonstrate that the CAPPS system provides acceptable acute and chronic properties for laser welding. Lasers Surg. Med. 29:336–342, 2001. © 2001 Wiley‐Liss, Inc.
A guide map to the terrain of gift value
Authors: Larsen Derek , Watson John J.
Published: August 2002

This article integrates a broad range of gift‐giving literature into a conceptual framework that puts the all too often overlooked construct of personal value at its core. Although there have been substantial contributions from the fields of anthropology, sociology, economics, and consumer behavior, efforts to model gift giving have failed to put the value of the gift‐giving experience at the center of the exchange. Within this article, a model of the gift‐giving experience that overcomes this critical shortcoming is proposed. The model establishes clear categories for breaking the giving process into easily examinable elements, and it is argued that although the concept of value is not a simple one, it should be central to any examination of the gift‐giving phenomenon. © 2001 John Wiley & Sons, Inc.
Wingless‐type frizzled protein receptor signaling and its putative role in human colon cancer
Authors: Uthoff Sonja M. S. , Eichenberger M. Robert , McAuliffe Tracy L. , Hamilton Crystal J. , Galandiuk Susan
Published: August 2002

We wish to identify new candidate genes involved in the pathogenesis of human colon cancer to better understand the diversity of phenotype presentation that varies from individual to individual. Our working hypothesis is that genetic polymorphism of genes in the Wingless‐type (Wnt) frizzled protein receptor pathway is associated with the susceptibility to develop colon cancer. The putative role of the Wnt pathway in sporadic human malignancy of the colon suggests involvement in inherited cancer as well. β‐catenin is the crucial messenger in frizzled receptor signaling, transmitting Wnt‐ligand signals such as signals from secreted apoptosis‐related proteins to the nucleus. It functions as a genome denunciator by initiating amplification of oncogenes. The net effect of β‐catenin depends on the magnitude of its accumulation in the cytoplasm and, therefore, upon expression profiles of genes in the Wnt pathway. We propose that variations in allelic frequencies of genes involved in the β‐catenin cascade may either promote or impede malignant transformation of the colon. If certain polymorphisms in Wnt signaling through β‐catenin predispose to colon cancer, this might manifest as decreased binding affinity of proteins such as axin or the adenomatous polyposis coli protein to β‐catenin. Association studies are proposed to test the hypothesis, which could serve as an initial step toward understanding the complexity of tumor biology. The clinical rationale in unraveling the genetic susceptibility to cancer lies in identification of a subgroup of individuals who may benefit from β‐catenin targeting agents, which could potentially overcome this genetic instability. © 2001 Wiley‐Liss, Inc.
Optimization of accelerated solvent extraction for the analysis of munitions residues in sediment samples
Authors: Onuska Francis I. , El‐Shaarawi A. H. , Terry K. , Vieira Eny M.
Published: August 2002

Accelerated solvent extraction (ASE) has been compared with a Soxhlet extraction for extracting and estimating the concentration of hexahydro‐1,3,5‐trinitro‐s‐triazine (RDX) and octahydro‐1,3,5,7‐tetrazocine (HMX) in sediment samples. Extraction of RDX and HMX was studied in terms of process kinetics and recovery. A three factor, 16 run triplicate experimental design was used to generate data on each of two extraction solvents, acetonitrile and a mixture of acetone–methanol (1:1). Response surface methods were used to model the dependence of the concentration on the experimental conditions and to establish the optimum extraction conditions. The results were complex in that several interactions were found among analyte, method, and solvent. Acetonitrile was superior to acetone–methanol for RDX and HMX from the perspectives of kinetics and recovery, due in part to a much higher solubility. The accelerated solvent extraction generally recovered more than the Soxhlet. In terms of sample throughput, the accelerated solvent extraction offers advantages over the Soxhlet. A spike recovery study using fortified sediment yielded complete recoveries of HMX and RDX. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 54–61, 2001
Hemichorea, moya‐moya, and ulcerative colitis
Authors: Shanahan P. , Hutchinson M. , Bohan A. , O' Donoghue D. , Sheahan K. , Owens A.
Published: August 2002

This is a case report linking chorea, colitis, and moya‐moya. The clear involvement in the vasculopathy of the basal ganglia offers an obvious substrate for the movement disorder.
Non‐standard Stokes and Navier–Stokes problems: existence and regularity in stationary case
Authors: Bernard J. M.
Published: August 2002

This paper is devoted to Stokes and Navier–Stokes problems with non‐standard boundary conditions: we consider, in particular, the case where the pressure is given on a part of the boundary. These problems were studied by Bégue, Conca, Murat and Pironneau. They proved the existence of variational solutions, indicating that these were solutions of the initial non‐standard problems, if they are regular enough, but without specifying the conditions on the data which would imply this regularity. In this paper, first we show that the variational solutions, on supposing pressure on the boundary Γ2 of regularity H1/2 instead of H−1/2, have their Laplacians in L2 and, therefore, are solutions of non‐standard Stokes problem. Next, we give a result of regularity H2, which we generalize, obtaining regularities Wm, r, m∈ℕ, m⩾2, r⩾2. Finally, by a fixed‐point argument, we prove analogous results for the Navier–Stokes problem, in the case where the viscosity νis large compared to the data. Copyright © 2002 John Wiley & Sons, Ltd.
Mathematical modelling of drug resistant malaria parasites and vector populations
Authors: Aneke S. J.
Published: August 2002

In this paper, we describe the phenomenon of drug resistant malaria infection in a hyperendemic region by a system of ordinary differential equations models. Different situations on both vectors and humans are described. The first presentations deal with single population each for both humans and vectors (with the human population fixed). These models are without resistant strains. The second group of models deal with both resistant and sensitive strains. Our focus in analysing the models is on establishing a unique positive asymptotic equilibrium for each of them. It is shown that (under suitable conditions in most cases) the equilibrium points are (locally) asymptotically stable. The biological significance of each of these points emerges as a by‐product. Copyright © 2002 John Wiley & Sons, Ltd.
Two‐turn contrawound toroidal helix antenna
Authors: Hansen R. C.
Published: August 2002

The two‐turn CWTHA is analyzed from a small diameter that allows constant current, through the third resonance. Around the third resonance, and around the first resonance and below, the bandwidth is much less than 1%. The very low (or very high) values of resistance make matching difficult and lossy. At the second resonance the resistance is modest, but the rapid change of reactance limits the bandwidth to a few percent. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 251–252, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10289
On the computing algorithms of the hybrid FEM/MLFMA
Authors: Sheng Xin‐Qing , Yung Edward Kai‐Ning
Published: August 2002

Several computing algorithms of the hybrid FEM/MLFMA, the conventional algorithm (CA), the direct–iterative decomposition algorithm (DIDA), and a new one, the iterative–iterative decomposition algorithm (IIDA), are described in this Letter. The required computing resources of these three algorithms are compared analytically and numerically. Several important numerical features of these algorithms are pointed out and confirmed. Criteria are given for the choice of computing algorithms. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 265–268, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10293
Simultaneous suppression of IMD2 and IMD3 in analog electroabsorption modulation
Authors: Sohn Sung‐Il , Han Sang‐Kook
Published: August 2002

A linearized optical modulation scheme using a dual parallel electroabsorption modulator (EAM) and an RF 180° hybrid junction is proposed. The IMD2 generated by each EAM is suppressed by controlling the dc bias voltage of the EAM, and the IMD3 is suppressed by having a proper input optical power split ratio and an RF 180° hybrid junction. Reductions of both the IMD2 and the IMD3 at the same operation voltage were achieved, and a subsequent SFDR enhancement of 29 dB was obtained. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 373–376, 2001.
Explicit formulas for obtaining the radiation characteristics of an antenna based on a three‐dimensional metallic photonic bandgap structure
Authors: He Sailing , Popov Mikhail , Qiu Min , Liao Zhigang , Simovski Constantin
Published: August 2002

An antenna based on a three‐dimensional metallic photonic bandgap (MPBG) structure consisting of many parallel metallic short wires is considered. An explicit method is introduced to calculate the radiation pattern for such an antenna system. The explicit method is verified numerically by comparing the results obtained by the finite‐difference time‐domain method. The present method improves the computation speed significantly. A genetic algorithm is used to make an optimal design for such a 3‐D MPBG structure‐based antenna. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 376–381, 2001.
Infrared microstrip dipole antennas—FDTD predictions versus experiment
Authors: Codreanu Iulian , Boreman Glenn D.
Published: August 2002

We report on the successful use of niobium microbolometers coupled to microstrip dipole antennas for the detection of midinfrared radiation. Measurements of the detector response versus antenna length performed at the 10.6 μm wavelength allowed us to identify the first three current‐wave resonances along the antenna arms. The detector response was also measured as a function of the radiation wavelength in the 9–11 μm spectral domain. Excellent agreement between the experimental results and finite‐difference time‐domain (FDTD) predictions was obtained. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 381–383, 2001.
Metastatic Ewing sarcoma/PNET of bone at diagnosis: Prognostic factors—a report from Saudi Arabia
Authors: Jenkin R. Derek , Al‐Fawaz Ibrahim , Al‐Shabanah Mohammed O. , Allam Ayman , Ayas Mouhab , Memon Muhammad , Rifai Samira , Schultz Henrik P.
Published: August 2002

Background

To evaluate outcome and prognostic factors in Saudi Arabian patients with metastatic Ewing sarcoma and PNET of bone (PMES) at diagnosis.

Procedure

Ninety‐nine of 304 (33%) consecutive patients with Ewing sarcoma and PNET of bone registered at our centre from 1975 to 1998, had metastatic disease at registration and 93 were available for analysis. The maximum x‐axis diameter of the primary tumor was used as the measure of primary tumor size. Usually a trial of systemic treatment was undertaken before a decision was made on local treatment. Standard chemotherapy regimens were used in all treated patients. Forty‐one (44%) patients did not receive radical local treatment due to an inadequate response to chemotherapy, or a decision not to undertake more than palliative treatment. Radical treatment of the primary site was radiation alone 41 (79%), resection alone 7 (13%), and resection and radiation 4 (8%).

Results

The 5‐year survival rates were 9% for all 93 evaluable patients, 16% for 52 patients who received chemotherapy and radical local treatment, 0% for 41 patients who received lesser treatment, 19% for 43 patients with lung metastases alone, and 0% (P = 0.002) for 50 patients with other sites involved. For 60 patients with imaging data, 5‐year survivals were 34 and 0% when the maximum transverse diameter of the primary tumor was < 10 cm (N = 20) and ≥ 10 cm (N = 40), respectively.

Conclusions

Small primary tumor size and the presence of lung metastases alone were the only significant favorable prognostic factors. Earlier diagnosis will be the basis for better results. Med Pediatr Oncol 2001;37:383–389. © 2001 Wiley‐Liss, Inc.
1H and 13C NMR study of 2‐hydroxyglutaric acid and its lactone
Authors: Bal Dominika , Gryff‐Keller Adam
Published: August 2002

Determination of the level and absolute configuration of 2‐hydroxyglutaric acid in a patient's urine is a method of diagnosing two metabolic diseases. Such a determination can be done with the aid of NMR spectroscopic methods. In this paper the careful interpretation of 1H and 13C NMR spectra of this metabolite and its lactone measured under conditions used in biomedical assays is reported. The 1H chemical shifts and spin–spin coupling constants were derived using the total lineshape analysis method. Copyright © 2002 John Wiley & Sons, Ltd.
Accurate measurement of 1J(195Pt, 14N) in K[Pt(NH3)Cl3] by complete lineshape analysis
Authors: Gore Ernest S.
Published: August 2002

Because the 195Pt triplet due to coupling with 14N in K[Pt(NH3)Cl3] in D2O is significantly broadened, 1J(195Pt, 14N) determined from the peak separation is not exactly equal to the true coupling constant. It is shown that an accurate value can be determined by a complete lineshape analysis. However, the previously published equation for the lineshape of a spin‐½ nucleus bound to a spin‐1 nucleus is not valid in this case because the intrinsic linewidth of the 195Pt resonance cannot be ignored. A closed expression for the lineshape is given which accounts for the intrinsic linewidth and gives a value for 1J(195Pt, 14N) at 300 K of 235.3±0.2 Hz, in good agreement with the value, 234 Hz, calculated from the published value of 1J(195Pt, 15N) and significantly different than the value, 230.4±1.7 Hz, determined from the peak separation. The T1 of 14N was measured directly by the inversion‐recovery technique and compared with the values extracted from the lineshape. The lineshape T1 values were shown to be unreliable unless T1 ≪ T20, where 1/T20 is the intrinsic linewidth of 195Pt. Also observed was a deuterium isotope effect on the chemical shift of 195Pt of −2.7 ppm per deuteron bound to N and a temperature variation of 0.74 ppm K−1 for the 195Pt chemical shift. Copyright © 2001 John Wiley & Sons, Ltd.
Total assignment of the 1H and 13C NMR data for felodipine and its derivatives
Authors: Jung Jihyun , Kim Laehee , Lee Chang Sik , Cho Yoon Hwan , Ahn Seung‐Ho , Lim Yoongho
Published: August 2002

The 1H and 13C NMR data for felodipine and its derivatives were completely assigned. Felodipine has 3‐ethyl and 5‐methyl esters which make the 1,4‐dihydropyridine asymmetric. It is, however, difficult to distinguish 2,6‐dimethyl groups in the NMR spectra. With the help of NOESY and computer‐aided molecular modeling, these groups can be assigned. Whereas the 1,4‐dihydropyridine of felodipine is connected through a methine carbon to a dichlorophenyl ring, the aromatic pyridine of felodipine derivatives is connected through a quaternary carbon. As a result, the three‐dimensional conformations between the pyridine ring and the phenyl ring have important implications. Copyright © 2001 John Wiley & Sons, Ltd.
1H and 13C NMR structure determination of new sesquiterpene glycosides isolated from Pittosporum viridiflorum viridiflorum
Authors: Ramanandraibe Voahangy , Rakotovao Marcelle , Frappier François , Martin Marie‐Thérèse
Published: August 2002

The acetone extract of fresh leaves of Pittosporum viridiflorum viridiflorum afforded new sesquiterpene glycosides, 4‐O‐β‐D‐glucopyranosylgermacra‐1(10),5‐diene and its 6′‐O‐acetyl and 2′‐O‐acetyl derivatives, the structures of which were elucidated by NMR methods. Copyright © 2001 John Wiley & Sons, Ltd.
Connectivities in molecules by INADEQUATE: recent developments
Authors: Buddrus J. , Lambert J.
Published: August 2002

The INADEQUATE (Incredible Natural Abundance DoublE QUAntum Transfer Experiment) consists of a pulse sequence which eliminates the NMR signals from isolated spins (spin system A) displaying signals from coupled spins (spin system AX or higher spin systems). It is of great importance when applied to molecules with skeleton elements such as carbon, silicon or tungsten, all of which contain a small percentage of spin‐½ isotopes embedded in magnetically inactive isotopes. Analysis of the AX type spectra gives one‐bond and long‐range coupling constants (see compound 6) and, most important, the connectivity pattern of the skeleton atoms in molecules of unknown structure such as the carbon compounds 1 or 2, the silicon compound 3 or the lithium compound 4b. Unfortunately, INADEQUATE is rather insensitive, in the case of carbon only one out of 104 molecules gives the desired response. Efforts to reduce this drawback are described; recently, a remarkable step forward has been made by concentrating the four lines of an AX spin system to just two signals (see Fig. 2). Copyright © 2001 John Wiley & Sons, Ltd.
The 2‐imino‐1,3‐selenazolidine group bonded to phosphorus and silicon: a multinuclear magnetic resonance study
Authors: Bakhmutova Ekaterina V. , Cruz Alejandro , Ramirez‐Trejo Raúl , Contreras Rosalinda , Wrackmeyer Bernd
Published: August 2002

A tris(imino)phosphane (3), its sulfide [3(S)], an iminodiphenylphosphane (4), and an iminotrimethylsilane (5), in all of which the imino group belongs to a pseudo‐ephedrine‐derived 2‐imino‐1,3‐selenazolidine ring, were prepared and studied by multinuclear magnetic resonance (1H, 13C, 15N, 29Si, 31P, 77Se NMR). By application of various 1D and 2D NMR techniques, NMR parameters such as the isotope induced chemical shifts 1Δ14/15N(31P) for 4, 1Δ14/15N(29Si) for 5, numerous coupling constants and chemical shifts could be obtained. The absolute sign of 1J(29Si,15N) (>0) was determined for 5. The largest values so far for 3J(77Se,31P) (198.0 Hz in 3 and 194.0 Hz in 4) were observed, and the absolute sign of these coupling constants 3J(77Se,31P) > 0 was determined, together with the signs of various other coupling constants involving 77Se or 31P. Copyright © 2001 John Wiley & Sons, Ltd.
Growth hormone inhibits apoptosis in in vitro produced bovine embryos
Authors: Kölle Sabine , Stojkovic Miodrag , Boie Gudrun , Wolf Eckhard , Sinowatz Fred
Published: August 2002

Growth hormone (GH) has recently been shown to exert distinct effects on the differentiation and metabolism of early embryos. Up to now, however, it is not clear whether GH is able to modulate apoptosis during early embryogenesis. Differential cell staining of 8‐day‐old bovine embryos cultured with 100 ng bovine recombinant GH (rbGH) per ml medium (synthetic oviduct fluid–polyvinylalcohol) demonstrated that GH significantly increased the number of inner cell mass (ICM) and trophectoderm cells in bovine expanded blastocysts. As shown by terminal deoxynucleotidyl transferase mediated dUTP labeling (TUNEL) supplementation of bGH decreased the percentage of 8‐day‐old embryos showing at least one apoptotic cell from 58 to 21%. The percentage of apoptotic cells in one blastocyst was significantly (P < 0.01) reduced from 4.6 to 1.1% by GH treatment. Incubation of the embryos with 150 mM vanillylnonanamide induced apoptosis in all embryos. Whereas in control embryos 14% of the embryonic cells were TUNEL‐positive, the percentage of apoptotic cells declined to 2.7% in the GH treated embryos. Expression of immunoreactive bcl‐2 in blastocysts was not affected by GH treatment. Synthesis of the bax protein which is known to promote apoptosis was reduced in embryos cultured with GH. Our results suggest that GH acts as survival factor during in vitro culture and reduces apoptosis by altering the bax to bcl‐2 ratio during early embryogenesis. Mol. Reprod. Dev. 61: 180–186, 2002. © 2002 Wiley‐Liss, Inc.
Origin and minimization of residual motion‐related artifacts in navigator‐corrected segmented diffusion‐weighted EPI of the human brain
Authors: Jiang Hangyi , Golay Xavier , van Zijl Peter C.M. , Mori Susumu
Published: August 2002

Motion sensitivity in diffusion‐weighted imaging (DWI) can be effectively suppressed using single‐shot echo‐planar imaging (EPI). However, segmented (multishot) EPI is often used to increase resolution and reduce spatial distortions, which in turn increases susceptibility to brain motion. The sources of these residual motion artifacts in navigator‐echo‐corrected segmented EPI images of the brain were investigated. The results indicate that the dominant source of these artifacts is cardiac pulsation with occasional involuntary movement of the subject. The relationship between the cardiac cycle and motion artifacts shows that optimum timing for the data acquisition is possible. In addition it is shown that the effects of involuntary motion can be removed by swapping k‐space data between redundant datasets. Magn Reson Med 47:818–822, 2002. © 2002 Wiley‐Liss, Inc.
VD‐AUTO‐SMASH imaging
Authors: Heidemann Robin M. , Griswold Mark A. , Haase Axel , Jakob Peter M.
Published: August 2002

Recently a self‐calibrating SMASH technique, AUTO‐SMASH, was described. This technique is based on PPA with RF coil arrays using auto‐calibration signals. In AUTO‐SMASH, important coil sensitivity information required for successful SMASH reconstruction is obtained during the actual scan using the correlation between undersampled SMASH signal data and additionally sampled calibration signals with appropriate offsets in k‐space. However, AUTO‐SMASH is susceptible to noise in the acquired data and to imperfect spatial harmonic generation in the underlying coil array. In this work, a new modified type of internal sensitivity calibration, VD‐AUTO‐SMASH, is proposed. This method uses a VD k‐space sampling approach and shows the ability to improve the image quality without significantly increasing the total scan time. This new k‐space adapted calibration approach is based on a k‐space–dependent density function. In this scheme, fully sampled low‐spatial frequency data are acquired up to a given cutoff‐spatial frequency. Above this frequency, only sparse SMASH‐type sampling is performed. On top of the VD approach, advanced fitting routines, which allow an improved extraction of coil‐weighting factors in the presence of noise, are proposed. It is shown in simulations and in vivo cardiac images that the VD approach significantly increases the potential and flexibility of rapid imaging with AUTO‐SMASH. Magn Reson Med 45:1066–1074, 2001. © 2001 Wiley‐Liss, Inc.
Rat lung MRI using low‐temperature prepolarized helium‐3
Authors: Kober Frank , Wolf Pierre‐Etienne , Vermeulen Gérard , Duhamel Guillaume , Lamalle Laurent , Leviel Jean‐Louis , Décorps Michel , Ziegler Anne
Published: August 2002

The purpose of this study was to evaluate the recently proposed technique of 3He prepolarization at low temperature and high field (Kober et al. Magn Reson Med 1999; 41:1084–1087) for fast imaging of the lung. Helium‐3 was cooled to 2.4 K in a magnetic field of 8 Tesla to obtain a polarization of 0.26%. The polarized 3He was warmed up to room temperature and transferred to a rat, with a final polarization of about 0.1%, large enough for acquiring a 3D image of the rat lung in 30 s. Magn Reson Med 45:1130–1133, 2001. © 2001 Wiley‐Liss, Inc.
Fast T1 mapping with volume coverage
Authors: Steinhoff S. , Zaitsev M. , Zilles K. , Shah N.J.
Published: August 2002

Four different sequences which enable high‐resolution, multislice T1 relaxation‐time mapping are presented. All these sequences are based on the Look‐Locker method with differences arising from the use of either a saturation‐recovery or inversion‐recovery module prior to data acquisition with a full k‐space or banded k‐space acquisition scheme. The methods were implemented on a standard clinical scanner and the accuracy of the T1 results was evaluated against spectroscopic measurements. The accuracy of the T1 maps validated by phantom imaging measurements is around 1% for species which relax with T1 times that mimic gray/white matter (T1 ≤ 1000 ms). Additionally, the inherent multislice, multipoint capability of the methods is demonstrated. Finally, in vivo results of the human brain obtained using the faster method are presented. The fastest data acquisition was achieved with a saturation‐recovery, banded k‐space method where k‐space was divided into three segments; an overall acquisition time of around 5 min (for species with T1 ≤ 1 sec) was achieved for a T1 map which can, in principle, provide whole‐brain coverage with a matrix size of 256 × 256 at multiple time‐points. Magn Reson Med 46:131–140, 2001. © 2001 Wiley‐Liss, Inc.
Evaluation of regional pulmonary perfusion using ultrafast magnetic resonance imaging
Authors: Levin David L. , Chen Qun , Zhang Ming , Edelman Robert R. , Hatabu Hiroto
Published: August 2002

An ultrafast MR sequence was used to measure changes in signal intensity during the first pass of intravascular contrast through the pulmonary circulation. From this, mean transit time, relative blood volume, and relative blood flow were calculated. Data were collected in an isogravitational plane in six healthy subjects. A slight but significant gradient in transit time was present, with faster times at the lung apex. A significant decrease in blood volume, compared with the lung base, was also seen in the apex. Significant decreases in blood volume and blood flow, compared with central portions of the lung, were seen in the lung periphery. Six additional subjects were imaged along a gravitational plane. A significant gradient in transit time was seen, with faster transit in dependent regions of the lung. MRI is able to evaluate regional differences in pulmonary perfusion with high spatial and temporal resolution. Magn Reson Med 46:166–171, 2001. © 2001 Wiley‐Liss, Inc.
The effect of myelinating Schwann cells on axons
Authors: Martini Rudolf
Published: August 2002

Myelinating Schwann cells control the number of neurofilaments and elevate the phosphorylation state of neurofilaments in the axon, eventually leading to the typical large axon caliber. Conversely, absence of myelin leads to lower amounts of neurofilaments, reduced phosphorylation levels, and smaller axon diameters. In addition, myelinating Schwann cells mediate the spacing of Na+ channel clusters during development of the node of Ranvier. When axons are associated with mutant Schwann cells in inherited neuropathies, their calibers are reduced and their neurofilaments are less phosphorylated and more closely spaced. Also, axonal transport is reduced and axons degenerate at the distal ends of long nerves. Myelin‐associated glycoprotein may mediate some aspects of Schwann cell–axon communication, but much remains to be learned about the molecular bases of Schwann cell–axon communication. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 456–466, 2001
Effects of cardiotrophin‐1 (CT‐1) in a mouse motor neuron disease
Authors: Mitsumoto Hiroshi , Klinkosz Bogdan , Pioro Erik P. , Tsuzaka Kazufumi , Ishiyama Takeo , O'Leary Rhona M. , Pennica Diane
Published: August 2002

Cardiotrophin‐1 (CT‐1) has potent survival‐promoting effects on motor neurons in vitro and in vivo and may be effective in treating motor neuron diseases (MND). We investigated the effects of CT‐1 treatment in wobbler mouse MND. Wobbler mice were randomly assigned to receive subcutaneously injected CT‐1 (1 mg/kg, n = 18, in two experiments) or vehicle (n = 18, in two experiments) daily, 6 times/week for 4 weeks after clinical diagnosis at age 3 to 4 weeks. Cardiotrophin‐1 treatment prevented deterioration in paw position and walking pattern abnormalities. Grip strength declined steadily in the vehicle group, whereas in the CT‐1 group it declined at week 1 but increased thereafter to exceed baseline strength by 5% (P = 0.0002) at week 4. Running speed was faster with CT‐1 (P = 0.007). Biceps muscle twitch tension, muscle weight, mean muscle fiber diameter, and intramuscular axonal sprouting were significantly greater with CT‐1 treatment than with vehicle treatment. Histometry revealed a trend that indicated CT‐1 modestly increased the number of immunoreactive motor neurons, as determined by both choline acetyltransferase and c‐Ret antibodies, and reduced the number of phosphorylated neurofilament immunoreactive perikarya (P = 0.05). The number of large myelinated motor axons significantly increased with treatment (206 versus 113, P = 0.01). We conclude that CT‐1 exerts myotrophic effects as well as neurotrophic effects in a mouse model of spontaneous MND, a finding that has potential therapeutic implications for human MND. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 769–777, 2001
A finite element algorithm for parameter identification of material models for fluid saturated porous media
Authors: Mahnken R. , Steinmann P.
Published: August 2002

In this contribution an algorithm for parameter identification of geometrically linear Terzaghi–Biot‐type fluid‐saturated porous media is proposed, in which non‐uniform distributions of the state variables such as stresses, strains and fluid pore pressure are taken into account. To this end a least‐squares functional consisting of experimental data and simulated data is minimized, whereby the latter are obtained with the finite element method. This strategy allows parameter identification based on in situ experiments. In order to improve the efficiency of the minimization process, a gradient‐based optimization algorithm is applied, and therefore the corresponding sensitivity analysis for the coupled two‐phase problem is described in a systematic manner. For illustrative purpose, the performance of the algorithm is demonstrated for a slope stability problem, in which a quadratic Drucker–Prager plasticity model for the solid and a linear Darcy law for the fluid are combined. Copyright © 2001 John Wiley & Sons, Ltd.