bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single‐coil arterial spin‐tagging for estimating cerebral blood flow as viewed from the capillary: Relative contributions of intra‐ and extravascular signal
Authors: Ewing James R. , Cao Yue , Fenstermacher Joseph 
Published: August 2002

AbstractThe single‐capillary model was applied to the exchange microvessels for water in the cerebral parenchyma and used to calculate blood‐to‐brain flux of water; the theory of the steady‐state arterial spin‐tagging (AST) technique for estimating cerebral blood flow (CBF) was revised to incorporate the presence of both extravascular (tissue) and capillary signal. A crucial element of the single‐coil AST experiment is that magnetization transfer (MT) shortens the effective T1 of the extravascular water, making it one‐quarter that of the T1 of capillary blood. Furthermore, the mean capillary transit time is on the order of the T1 of the extravascular water. The single‐coil AST experiment is distinguished from other methods which use water as an indicator for measurement of CBF in that the (flow‐dependent) populations of inverted protons in the intra‐ and extravascular compartments can be nearly equal for normal physiological conditions. The following questions are considered: Is single‐coil AST contrast linear in resting CBF? Is contrast in the single‐coil AST technique likely to be linear under changes in CBF in normal tissue? Is the contrast likely to be linear in such common pathologies as stroke and cerebral tumor? We demonstrate that, if the population of inverted protons in the microvessels is included in the experiment, the voxel population of inverted protons will be approximately linear with flow across a broad range of flow values. We predict that the single‐coil AST experiment will systematically overestimate resting CBF for flows in the normal range, that changes in CBF in normal tissue will produce an approximately linear response in AST measurement, and, finally, we predict the operating characteristics of the measurement in common cerebral pathologies. Magn Reson Med 46:465–475, 2001. © 2001 Wiley‐Liss, Inc.
The natural history of long thoracic and spinal accessory neuropathies
Authors: Friedenberg Scott M. , Zimprich Todd , Harper C. Michel 
Published: August 2002

AbstractA cohort of 106 patients with electrodiagnostically confirmed long thoracic neuropathy (50 patients) or spinal accessory neuropathy (56 patients) seen at the Mayo Clinic over a 22‐year period were retrospectively studied to better understand the natural history of these disorders and to determine the role of electrodiagnostic testing in predicting prognosis. Mean follow‐up was 48 and 50 months, respectively. Good functional recovery was generally observed regardless of the results of electrodiagnostic studies, but improvement in the amplitude of the spinal accessory compound muscle action potential on serial nerve conduction studies tended to predict a good outcome. No electrodiagnostic findings correlated with poor outcome. Traumatic neuropathies generally did worse than neuropathies of other causes. In spinal accessory neuropathies, involvement of the dominant limb, scapular winging, and impaired arm elevation were associated with a poor outcome. Our data suggest that, contrary to other focal neuropathies, the electrodiagnostic findings do not predict functional outcome in these neuropathies. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
The clique partitioning problem: Facets and patching facets
Authors: Oosten Maarten , Rutten Jeroen H. G. C. , Spieksma Frits C. R. 
Published: August 2002

AbstractThe clique partitioning problem (CPP) can be formulated as follows: Given is a complete graph G = (V, E), with edge weights wij ∈ ℝ for all {i, j} ∈ E. A subset A ⊆ E is called a clique partition if there is a partition of V into nonempty, disjoint sets V1,…, Vk, such that each Vp (p = 1,…, k) induces a clique (i.e., a complete subgraph), and A = ∪ {{i, j}|i, j ∈ Vp, i ≠ j}. The weight of such a clique partition A is defined as Σ{i,j}∈A wij. The problem is now to find a clique partition of maximum weight. The clique partitioning polytope P is the convex hull of the incidence vectors of all clique partitions of G. In this paper, we introduce several new classes of facet‐defining inequalities of P. These suffice to characterize all facet‐defining inequalities with right‐hand side 1 or 2. Also, we present a procedure, called patching, which is able to construct new facets by making use of already‐known facet‐defining inequalities. A variant of this procedure is shown to run in polynomial time. Finally, we give limited empirical evidence that the facet‐defining inequalities presented here can be of use in a cutting‐plane approach for the clique partitioning problem. © 2001 John Wiley & Sons, Inc.
Agonists cause endocytosis of nicotinic acetylcholine receptors on cultured myotubes
Authors: St. John Paul A. , Gordon Herman 
Published: August 2002

AbstractRegulated trafficking of neurotransmitter receptors in excitable cells may play an important role in synaptic plasticity. In addition, agonist‐induced endocytosis of nicotinic acetylcholine receptors (nAChRs) in particular might be involved in nicotine tolerance and addiction. The existing evidence concerning regulated internalization of cell‐surface nAChRs is indirect and equivocal, however. In the present study, radioligand binding and fluorescence microscopy were used to show that agonists cause substantial endocytosis of nAChRs on cultured myotubes. Exposure to carbachol or nicotine caused a decrease in the intensity of fluorescent labeling of clusters of cell‐surface nAChRs that was blocked by low temperature. Overall, myotubes exposed to carbachol or nicotine bound 50–70% less [125I]‐α‐bungarotoxin on the cell surface than untreated cells. The effect of carbachol was significant within 5 min, increased progressively for at least 4 h, and had a sensitivity of 100 nM or less. Exposure to carbachol caused the appearance or dramatic expansion of an intracellular pool of nAChRs, which were localized to discrete, largely perinuclear structures. A pulse‐chase labeling protocol allowed the selective labeling and localization of nAChRs that had been internalized from the cell surface. In untreated cells, very little internalization of nAChRs occurred over a period of 3 h, indicating that constitutive endocytosis of receptors over this period was minimal. Exposure to carbachol, however, caused a dramatic increase in the endocytosis of nAChRs. These results provide direct evidence that agonists, including the tobacco alkaloid nicotine, can cause substantial endocytosis of cell‐surface nAChRs. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 212–223, 2001
Higher‐order hybrid‐mixed axisymmetric thick shell element for vibration analysis
Authors: Kim Jin Gon , Kim Yoon Young 
Published: August 2002

AbstractIn this study, we present free vibration analysis of shells of revolution using the hybrid‐mixed finite element. The present hybrid‐mixed element, which is based on the modified Hellinger–Reissner variational principle, employs consistent stress parameters corresponding to cubic displacement polynomials with additional nodeless degrees to resolve the numerical difficulties due to the spurious constraints. The stress parameters are eliminated and the nodeless degrees are condensed out by the Guyan reduction. Several numerical examples show that the present element with cubic displacement interpolation functions and consistent quadratic stress functions is highly accurate for the free vibration analysis of shells of revolution, especially for higher vibration modes. Copyright © 2001 John Wiley & Sons, Ltd.
Complexity in local stakeholder coordination: decentralization and community water management in Northern Ghana
Authors: Jackson Edward T. , Gariba Sulley 
Published: August 2002

AbstractStakeholder coordination is a prominent theme in current development discourse. Experience with decentralization and community water management in northern Ghana highlights the complexities of coordinating stakeholders at the local level. In this case, roles and responsibilities must be clarified between legislated sub‐district structures on the one hand, and civic water groups on the other. This is especially important with regard to resolving which party should collect revenues and manage assets and expenditures in the water sector. The key mechanism for addressing these issues is the District Assembly, which is empowered under the decentralization law to coordinate stakeholders, both ‘horizontally’, across social actors, and ‘vertically’, between the national and sub‐district levels. While such local‐level dynamics are indeed complex and challenging, they are at the same time probably more amenable to at least medium‐term resolution than stakeholder competition issues at the national level. Copyright © 2002 John Wiley & Sons, Ltd.
The effect of ionic strength on the viscosity of sodium alginate solution
Authors: Zhang Hucheng , Wang Hanqing , Wang Jianji , Guo Ruifang , Zhang Qingzhi 
Published: August 2002

AbstractThe viscosities of aqueous sodium alginate solutions were measured in different NaCl concentrations (C
s) at 298 K. Based on the Odijk–Skolnick–Fixman theories, the electrostatic persistence lengths were calculated for various ionic strengths. The intrinsic persistence length of sodium alginate in solution was determined to be 125 Å by the method suggested by Odijk. In the region of $\hbox{C}_{\rm S}^{-1/2}> 6.5$, the increase in intrinsic viscosity, [η], for sodium alginate on decreasing the C
s is due to the larger contribution of electrostatic persistence length to the total persistence length, and the departure of [η]
calc from [η]
expl is attributed to the variation of the Flory Φ constant with ionic strength. A peak was observed in the plot of reduced viscosity v. sodium alginate concentration at a constant low ionic strength. As in the treatment of Rinaudo et al., this maximum in reduced viscosity is attributed to a preferential intermolecular distance. The roles of electrostatic persistence length, the critical inter‐rod spacing and the effect of added salt concentration on this maximum are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Automated complete slide digitization: a medium for simultaneous viewing by multiple pathologists
Authors: Leong F. J. W‐M. , McGee J. O'D. 
Published: August 2002

AbstractDevelopments in telepathology robotic systems have evolved the concept of a ‘virtual microscope’ handling ‘digital slides’. Slide digitization is a method of archiving salient histological features in numerical (digital) form. The value and potential of this have begun to be recognized by several international centres. Automated complete slide digitization has application at all levels of clinical practice and will benefit undergraduate, postgraduate, and continuing education. Unfortunately, as the volume of potential data on a histological slide represents a significant problem in terms of digitization, storage, and subsequent manipulation, the reality of virtual microscopy to date has comprised limited views at inadequate resolution. This paper outlines a system refined in the authors' laboratory, which employs a combination of enhanced hardware, image capture, and processing techniques designed for telepathology. The system is able to scan an entire slide at high magnification and create a library of such slides that may exist on an internet server or be distributed on removable media (such as CD‐ROM or DVD). A digital slide allows image data manipulation at a level not possible with conventional light microscopy. Combinations of multiple users, multiple magnifications, annotations, and addition of ancillary textual and visual data are now possible. This demonstrates that with increased sophistication, the applications of telepathology technology need not be confined to second opinion, but can be extended on a wider front. Copyright © 2001 John Wiley & Sons, Ltd.
Two‐ and three‐dimensional ultrasound in malformations of the medullary canal: report of four cases
Authors: Bonilla‐Musoles Fernando , Machado Luis E. , Osborne Newton G. , Muñoz Elkin A. , Raga Francisco , Blanes Javier , Bonilla Jr Francisco 
Published: August 2002

AbstractA comparison between two‐dimensional (2D), and three‐dimensional (3D) ultrasonography was made in four fetuses diagnosed with neural tube defect (NTD) in the first half of pregnancy. 3D ultrasonography (orthogonal and multiplanar systems) proved to be an excellent complement to 2D, particularly when using orthogonal planes. When using the 3D multiplanar surface imaging system, excellent images of the malformations can be rapidly obtained. Copyright © 2001 John Wiley & Sons, Ltd.
Novel mutations in the human CYP21 gene
Authors: Levo Antti , Partanen Jukka 
Published: August 2002

AbstractThe great majority of genetic defects underlying steroid 21‐hydroxylase deficiency appear to result from intergenic recombinations between the homologous CYP21 and CYP21P genes. For a minority, novel sporadic point mutations have been detected. De novo mutations in CYP21 have also been reported, but only a few studies have systematically screened their occurrence. We here describe a population‐based patient sample in order to estimate the rate of single‐family (i.e. sporadic) and de novo germline mutations in the human CYP21 locus. Among 76 Finnish families were observed three single‐family mutations and two de novo mutations in CYP21. The rates obtained, ∼5% and ∼2% for novel and de novo mutations, respectively, indicate that they are not rare and that their occurrence should not be ignored in genetic diagnostics of this disorder. Copyright © 2001 John Wiley & Sons, Ltd.
Animal models of fetal renal disease
Authors: Peters Craig A. 
Published: August 2002

AbstractFetal models of urinary tract disease have been used for many years and have provided unique and important insights into the pathophysiology of these conditions. This review will summarize the principal model systems used and the current directions of investigation. These models (including rabbit, opossum, sheep and recently swine) have demonstrated that in utero obstruction of the urinary tract alters renal growth, differentiation and produces stereotypical patterns of tissue response, particularly fibrosis. New molecular understanding of these processes has identified specific mechanisms that may be key elements in the development of renal dysfunction due to obstruction. These factors include the renin–angiotensin system (RAS) and its interaction with TGF‐β in altering growth regulation and tissue fibrosis. These factors offer the prospect of clinical utility as markers of disease progression as well as pharmacologic therapy. Gene knockout systems have opened a new horizon of molecular models of congenital obstructive uropathy with insights into the role of the RAS in particular. It remains to be defined how closely these knockouts represent the human conditions they resemble. Continued application of fetal models of urinary obstruction, integrating large animal and knockout systems offers promise for improved diagnosis and treatment in these challenging conditions. Copyright © 2001 John Wiley & Sons, Ltd.
Validity and completeness of the General Practice Research Database for studies of inflammatory bowel disease
Authors: Lewis James D. , Brensinger Colleen , Bilker Warren B. , Strom Brian L. 
Published: August 2002

AbstractPurposeThe objective of this study was to evaluate the validity and completeness of the General Practice Research Database (GPRD) as a tool for research into inflammatory bowel disease epidemiology.MethodsPatients diagnosed with inflammatory bowel disease were identified from GPRD. Mailed surveys were sent to the general practitioner caring for a stratified random sample of 170 of these patients and collected information on the diagnosis of inflammatory bowel disease and the most recent surgery and hospitalization.ResultsUsable surveys were returned for 157 patients (92%). The inflammatory bowel disease diagnosis was highly probable or probable in 144 (92%, 95% CI 86 to 96%). Among the 53 patients with a potentially incident inflammatory bowel disease diagnosis, 33 (62%) had the first recorded diagnosis in GPRD within 30 days of the date reported in the survey (median difference −8 days; interquartile range 0 to −81days). Of 12 surgeries and 25 hospitalizations reported in the survey, 11 (92%) and 19 (76%) were identified in GPRD, respectively.ConclusionsThe diagnosis of inflammatory bowel disease in GPRD appears reliable for most patients. Important medical events such as hospitalizations and surgery are recorded at a high rate, although algorithms to identify these events are complex. Copyright © 2002 John Wiley & Sons, Ltd.
Triphenylphosphine oxide‐based bismaleimide and poly(bismaleimide): Synthesis, characterization, and properties
Authors: Liu Ying Ling , Liu Yuan Ling , Jeng Ru Jong , Chiu Yie‐Shun 
Published: August 2002

AbstractA novel phosphorus‐containing bismaleimide, 3,3′‐bis(maleimidophenyl)phenylphosphine oxide (BMPPPO), was synthesized from triphenylphosphine oxide. This bismaleimide exhibited good solubility in common organic solvents, such as methylethylketone, methylisobutylketone, dichloromethane, chloroform, tetrahydrofuran, acetone, methanol, ethanol, and hot toluene. A low melting point (Tm = 148 °C), a relatively low polymerization temperature (Tp = 214 °C), and a wide processing window (Tp − Tm = 66 °C) were also obtained for BMPPPO. This implies better processing capability. In contrast to most known phosphorus‐containing polymers, the incorporation of BMPPPO into poly(bismaleimide) enhanced the polymer glass‐transition temperature. Thermal stability at temperatures over 550 °C and char yields in the high‐temperature region over 700 °C were also improved. As a result, the flame‐retardant properties of the poly(bismaleimide)s were improved. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1716–1725, 2001
Copolymerization of propylene with various higher α‐olefins using silica‐supported rac‐Me2Si(Ind)2ZrCl2
Authors: Xu Jun‐Ting , Zhu Yin‐Bang , Fan Zhi‐Qiang , Feng Lin‐Xian 
Published: August 2002

AbstractThe copolymerization of propylene with 1‐hexene, 1‐octene, 1‐decene, and 1‐dodecene was carried out with silica‐supported rac‐Me2Si(Ind)2ZrCl2 as a catalyst. The copolymerization activities of the homogeneous and supported catalysts and the microstructures of the resulting copolymers were compared. The activity of the supported catalyst was only one‐half to one‐eighth of that of the homogeneous catalyst, depending on the comonomer type. The supported catalyst copolymerized more comonomer into the polymer chain than the homogeneous catalyst at the same monomer feed ratio. Data of reactivity ratios showed that the depression in the activity of propylene instead of an enhancement in the activity of olefinic comonomer was responsible for this phenomenon. We also found that copolymerization with α‐olefins and supporting the metallocene on a carrier improved the stereoregularity and regioregularity of the copolymers. The melting temperature of all the copolymers decreased linearly with growing comonomer content, regardless of the comonomer type and catalyst system. Low mobility of the propagation chain in the supported catalyst was suggested as the reason for the different polymerization behaviors of the supported catalyst with the homogeneous system. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3294–3303, 2001
Rheological properties and foam processability for blends of linear and crosslinked polyethylenes
Authors: Yamaguchi Masayuki , Suzuki Ken‐Ichi 
Published: August 2002

AbstractThe effect of blending crosslinked linear low‐density polyethylene (cLLDPE) on the rheological properties and foam processability of linear low‐density polyethylene was studied. A small addition of cLLDPE, which had a low density of crosslink points, enhanced strain‐hardening behavior in the elongational viscosity to a great degree, although it had little effect on the steady‐state shear viscosity. The enhanced strain hardening reduced heterogeneous deformation during foaming. As a result, a foam with a uniform cell size distribution was obtained. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2159–2167, 2001
Life after cancer: adaptation issues faced by Chinese gynaecological cancer survivors in Hong Kong
Authors: Molassiotis Alexander , Chan Carmen W.H. , Yam Bernard M.C. , Chan Eunice S.J. , Lam Charlotte S.W. 
Published: August 2002

AbstractAn explorative study using qualitative data collection methods was used to look at the adaptation issues faced by Chinese survivors of gynaecological cancers. Eighteen women who were free from illness and between 2 and 16 years post‐diagnosis participated. Content analysis of the data revealed that cancer and its treatment led to a positive revival of these women as they re‐evaluated their life, started treasuring family relationships, improved their mood and became more sensitive to other people's needs. However, they also described problems with marital relationships, concerns about the future of their children, sexuality and femininity, loss of fertility and discomfort due to pain and weakness. A third of the sample reported that their husbands had extramarital affairs. Despite this, women, especially those who had good communication with their partners, commented that they maintained a loving relationship. Cultural beliefs and misconceptions about sexual functioning were also depicted as affecting adaptation to illness. Long‐term psychosocial care may help these women to adapt better to the demands of the illness, especially sexual and psychosexual rehabilitation, as sexual problems were reported by all women in the study. Copyright © 2002 John Wiley & Sons, Ltd.
Individual quality of life in patients with leukaemia and lymphoma
Authors: Montgomery Charles , Pocock Marilyn , Titley Kirsten , Lloyd Keith 
Published: August 2002

AbstractWith increasingly sophisticated chemotherapy regimes being prescribed the quality of life of cancer patients has become a key outcome measure. Little has been reported concerning the experience of patients with haematological malignancy receiving chemotherapy. The objective of this study was to evaluate the clinical usefulness of a novel quality of life measure—the Schedule for the Evaluation of Individual Quality of Life—Direct Weighting (SEIQoL‐DW) in a sample of patients with either leukaemia or lymphoma. Fifty‐one patients from the haematology clinic and in‐patient unit at The Royal Devon and Exeter Hospital completed the SEIQoL‐DW; in addition, each patient completed the Hospital Anxiety and Depression Scale (HADS) and a ten item questionnaire covering aspects of their treatment and satisfaction with information provided. The practical application of the SEIQoL‐DW is described and two patients quality of life profiles are illustrated for comparison. The relationship between quality of life, satisfaction with information provided and psychological distress as measured by the HADS is discussed. Copyright © 2002 John Wiley & Sons, Ltd.