bluuebunny/crossref_metadata_2025_split huggingface dataset:
Will a Marshall Plan for Africa make poverty history?
Authors: Lockwood Matthew 
Published: July 2005

AbstractA large increase in aid for Africa is a priority for both UK government and non‐governmental organizations (NGOs) in 2005. Despite a history of aid dependence and low growth, there is evidence that aid has a positive effect in Africa. But more aid alone will not produce rapid growth and poverty reduction. Africa's governance record is very poor and attempts at governance reform have largely failed without commitment from leaders. Equally, the policy conditionality debate shows that domestic political considerations have driven the shaping of economic policy, more than donor pressures. The clientelist account of African politics provides a coherent explanation for poor governance, partial and gradual policy change, and also the failure of governance reforms. It also points to a different policy agenda for aid. Copyright © 2005 John Wiley & Sons, Ltd.
Development assistance and development finance: evidence and global policy agendas
Authors: Addison Tony , Mavrotas George , McGillivray Mark 
Published: July 2005

AbstractUnderstanding the development effects of official aid is crucial to building a better bridge between research and policy. This paper reviews the current evidence regarding the impact of aid on growth and poverty reduction, and develops a new narrative. In the light of this narrative, the paper then examines aid trends, focusing on the regions of sub‐Saharan Africa and the Pacific. The paper then turns to recent discussion of new and innovative sources of development finance and considers how research has influenced the policy debate through a recent World Institute for Development Economics Research (UNU–WIDER) study for the United Nations (UN) General Assembly. The paper concludes that aid broadly works, that poverty would be higher in the absence of aid, and that the shortfall in aid during the 1990s has, by implication, made it more difficult to meet the Millennium Development Goals (MDGs). Hence, a considerable catch‐up in aid and other development finance flows is now necessary if poverty is to be substantially reduced by 2015. Copyright © 2005 John Wiley & Sons, Ltd.
Stabilization of Enzyme by Exclusive Volume Effect in Hydrophobically Controlled Polymer Microcapsules
Authors: Kim Jin‐Woong , Jung Mi‐Ok , Kim Yong‐Jin , Ryu Jee‐Hyun , Kim Junoh , Chang Ih‐Seop , Lee Ok‐Sub , Suh Kyung‐Do 
Published: July 2005

AbstractSummary: This communication describes an enzyme stabilization method that allows the use of enzymes irrespective of environmental factors, especially heat, while maintaining their activity for a long time. We have designed enzyme microcapsules that consist of papain enzyme cores, poly(propylene glycol) interlayers, and poly(ε‐caprolactone) walls. By confocal laser scanning microscopy measurements and the thermal stability of papain‐loaded microcapsules, it is demonstrated that the papain is surrounded by a hydrophobic polyol layer and stabilized by the exclusive volume effect. In our study, improved thermal stability can be obtained by using more hydrophobic long‐chained polyols, which is understood to be attributed to the effective formation of a hydrophobic polyol layer between the papain and the polymer wall by means of conformational anchoring in the interface.(A) A CLSM image of a PCL microcapsule containing FITC‐labeled papain and RBITC‐labeled PPG at the same time. (B) A scheme of the role of hydrophobic polyols in the interface of enzyme and polymer.magnified image(A) A CLSM image of a PCL microcapsule containing FITC‐labeled papain and RBITC‐labeled PPG at the same time. (B) A scheme of the role of hydrophobic polyols in the interface of enzyme and polymer.
Tailoring of Three‐Phase Crystalline Systems in Isotactic Poly(propylene)
Authors: Obadal Martin , Čermák Roman , Stoklasa Karel 
Published: July 2005

AbstractSummary: A novel method for the tailoring of unique three‐phase crystalline systems in isotactic poly(propylene) has been proven. It is based on a synergistic application of a specific β‐nucleating agent and high pressure during crystallization. The formation of a γ phase was supported by elevated pressure and high temperature during crystallization; under these conditions the growth of both β and α phases was significantly suppressed. Nevertheless, during the course of crystallization at lower pressure and/or lower temperatures, strong β‐nucleation efficiency favored the formation of a β phase.
magnified image
Effects of N‐acetylcysteine on glutathione oxidation and fatigue during handgrip exercise
Authors: Matuszczak Yves , Farid Mehran , Jones Jeffrey , Lansdowne Samme , Smith Melissa A. , Taylor Addison A. , Reid Michael B. 
Published: July 2005

AbstractFatigue of hand and forearm muscle groups can limit task performance by astronauts wearing space suits. Countermeasures to delay fatigue would therefore be useful to the space program. N‐acetylcysteine (NAC) has been shown to inhibit fatigue during other tasks so we tested its effects during handgrip exercise. Volunteers practiced isometric handgrip maneuvers until performance was reproducible over three successive sessions (baseline). Performance then was retested after ingesting NAC (150 mg.kg−1) or saline. Drug administration increased NAC and cysteine blood levels (P < 0.001). Performance of sustained maximal efforts was unaffected. During repetitive submaximal efforts, NAC delayed fatigue (130% baseline) and inhibited glutathione oxidation. Saline did not alter glutathione status or performance of sustained maneuvers; repetitive task performance was increased by 15% (P < 0.05), a placebo effect. These data indicate that NAC supports glutathione homeostasis in exercising humans and may delay muscle fatigue during repetitive handgrip exercise. Our findings support oxidative stress as a causal factor in human muscle fatigue and argue for larger translational studies to define NAC effects on human performance. Muscle Nerve, 2005
Pulmonary function tests and blood gases in worsening myasthenia gravis
Authors: Thieben Mark J. , Blacker David J. , Liu Peter Y. , Harper C. Michel , Wijdicks Eelco F. M. 
Published: July 2005

AbstractThe aim of this study was to determine whether pulmonary function tests have a role in predicting the need for ventilation support in myasthenia gravis. Medical records were reviewed for 42 patients with severe myasthenia gravis who required 55 admissions to the intensive care unit. Patients with a vital capacity of more than 20 ml/kg, a maximal expiratory pressure more than 40 cm H2O, or a maximal inspiratory pressure more negative than −40 cm H2O are unlikely to require mechanical ventilation. A decline of 30% or more in maximal inspiratory pressure predicted a group at higher risk of requiring mechanical or noninvasive ventilation. Hypercapnia was frequent and was more common in patients who required mechanical ventilation. Worsening of these pulmonary function and blood gas values in patients with myasthenia gravis may guide decisions about intubation and ventilatory support. Muscle Nerve, 2005
Desmoglein 2 is expressed abnormally rather than mutated in familial and sporadic gastric cancer
Authors: Biedermann Karin , Vogelsang Holger , Becker Ingrid , Plaschke Susanne , Siewert Jörg Rüdiger , Höfler Heinz , Keller Gisela 
Published: July 2005

AbstractAlterations of the cell adhesion molecule E‐cadherin have been demonstrated in sporadic and hereditary gastric carcinomas. A cell adhesion molecule with functional similarity to E‐cadherin is desmoglein 2 (Dsg2), a major component of the desmosomes. In this study, we investigated whether alterations of Dsg2 are involved in gastric carcinogenesis and whether germline mutations contribute to a genetic predisposition in familial gastric cancer patients with no germline mutations in the E‐cadherin gene. Seventy‐five formalin‐fixed, paraffin‐embedded tissues from 37 familial and 38 sporadic gastric carcinomas were analysed for Dsg2 expression by immunohistochemistry. DNA from 31 familial gastric cancer patients was analysed for germline mutations and five sporadic tumours were analysed for somatic mutations by DHPLC. Of the 75 tumours, 25 (33%) demonstrated abnormal (reduced and/or non‐membrane‐associated) Dsg2 expression. There was a trend towards more frequent abnormal expression in diffuse type (42%) than in intestinal type tumours (18%) (p = 0.066). One germline missense variant leading to a non‐conservative amino acid change (c. 2810 C > A, Thr 937 Asn) was found in a familial gastric cancer patient with a diffuse type tumour. No somatic mutations were identified. The observed abnormal expression of Dsg2 protein suggests that this molecule is involved in the carcinogenesis of a subset of gastric carcinomas, in particular of the diffuse type. Somatic mutations in the gene do not seem to be a very frequent inactivation event and the finding of no clear pathogenic germline mutation rules out Dsg2 as a major gastric cancer predisposition gene. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Co‐expression of c‐kit and stem cell factor in primary and metastatic nasopharyngeal carcinomas and nasopharyngeal epithelium
Authors: Sheu Lai‐Fa , Lee Wen‐Cheng , Lee Herng‐Sheng , Kao Woei‐Yau , Chen Ann 
Published: July 2005

AbstractExpression of c‐kit has been demonstrated in 33% of adult nasopharyngeal carcinomas (NPCs) and in 88% of paediatric NPCs. Patients with tumours expressing c‐kit tend to exhibit better survival, but a paracrine/autocrine function for the stem cell factor (SCF)/c‐kit system in nasopharyngeal carcinomas has not been reported. This study evaluated the expression of c‐kit and SCF by immunohistochemical staining of nasopharyngeal epithelium (NPE) and of primary and metastatic NPCs. In addition, c‐kit and SCF expression were studied in HONE‐1 NPC cells by immunoprecipitation and western blotting. Expression of c‐kit and SCF was detected in 75% and 57% of NPE, respectively, and there was 48% co‐expression. In primary NPCs, 86% expressed c‐kit, 69% had SCF expression, and there was 67% co‐expression. In metastatic NPCs, 76% expressed c‐kit, 72% expressed SCF and there was 68% co‐expression. Co‐expression of c‐kit and SCF with tyrosine autophosphorylation of p145c − kit was demonstrated in HONE‐1 NPC cells. In addition, the expression level of c‐kit and its autophosphorylation status was not obviously influenced by the transient co‐expression of Epstein–Barr nuclear antigen 1 (EBNA1) and latent membrane protein 1 (LMP1). Co‐expression of c‐kit and SCF is therefore commonly found in nasopharyngeal epithelium and NPCs, and in HONE‐1 NPC cells with autoactivation possibly independent of the co‐expression of EBNA1 and LMP1. All of these findings suggest that autoactivation of SCF/c‐kit signalling may be a potent regulator of the nasopharyngeal epithelial barrier and of immune function at the nasopharyngeal mucosa surface, and may contribute to the carcinogenesis and progression of NPC. Further molecular analysis is required to evaluate the possibility of treatment with tyrosine kinase inhibitors in NPC, analogous to the treatment of gastrointestinal stromal tumours with STI571. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
First‐trimester screening for Down syndrome with ductus venosus Doppler studies in addition to nuchal translucency and serum markers
Authors: Borrell Antoni , Gonce Anna , Martinez Josep M. , Borobio Virginia , Fortuny Albert , Coll Oriol , Cuckle Howard 
Published: July 2005

AbstractObjectiveTo estimate the improvement in screening efficiency when fetal ductus venosus Doppler studies are added to existing first‐trimester Down syndrome screening protocols.MethodsStatistical modelling was used with parameters derived from prospective ductus venosus studies and from the published literature. The pulsatility index for veins (PIV), was determined in the fetal ductus venosus for 3706 unaffected and 25 Down syndrome pregnancies at 10–14 weeks' gestation. Concurrent nuchal translucency measurement and maternal serum pregnancy associated plasma protein A and free‐β human chorionic gonadotrophin were also measured.ResultsThe median PIV in Down syndrome was 1.70 times higher than in unaffected pregnancies (95% confidence interval 1.36–2.12). PIV levels followed an approximately log Gaussian distribution with log10 standard deviations of 0.193 and 0.076 in Down syndrome and unaffected pregnancies. There were no statistically significant correlations between PIV and the other markers. Modelling predicts that for a fixed 5% false‐positive rate, the addition of PIV to nuchal translucency alone will increase the detection rate from 76 to 85%, and combined with serum markers, from 88 to 92%. For a fixed 85% detection rate, the false‐positive rate reduced from 15 to 4.8% and from 3.2 to 1.2% respectively.ConclusionDuctus venosus Doppler studies can substantially improve Down syndrome screening efficiency. Copyright © 2005 John Wiley & Sons, Ltd.
Binary copolymerization with full depropagation: A study of methyl methacrylate/α‐methyl styrene copolymerization
Authors: Leamen M. J. , McManus N. T. , Penlidis A. 
Published: July 2005

AbstractThe kinetics of the copolymerization of α‐methyl styrene and methyl methacrylate (MMA) have been revisited for the bulk system. Reactivity ratios and other kinetic parameter estimates based upon a copolymerization model developed by Kruger et al. (Makromol Chemie 1987, 188, 2163–2175) have been determined for a range of temperatures (60–140 °C). An interesting phenomenon has been uncovered, which shows that there is a distinct difference in copolymer composition predicted by the model when compared with experimental data at feed ratios of MMA below a critical value. This deviation also appears to be influenced by the reaction temperature. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3868–3877, 2005
Synthesis of methyl methacrylate, styrene, and isobutylene multiblock copolymers using atom transfer and cationic polymerization
Authors: Toman Luděk , Janata Miroslav , Spěváček Jiří , Vlček Petr , Látalová Petra , Sikora Antonín , Masař Bohumil 
Published: July 2005

AbstractABCBA‐type pentablock copolymers of methyl methacrylate, styrene, and isobutylene (IB) were prepared by the cationic polymerization of IB in the presence of the α,ω‐dichloro‐PS‐b‐PMMA‐b‐PS triblock copolymer [where PS is polystyrene and PMMA is poly(methyl methacrylate)] as a macroinitiator in conjunction with diethylaluminum chloride (Et2AlCl) as a coinitiator. The macroinitiator was prepared by a two‐step copper‐based atom transfer radical polymerization (ATRP). The reaction temperature, −78 or −25 °C, significantly affected the IB content in the resulting copolymers; a higher content was obtained at −78 °C. The formation of the PIB‐b‐PS‐b‐PMMA‐b‐PS‐b‐PIB copolymers (where PIB is polyisobutylene), prepared at −25 (20.3 mol % IB) or −78 °C (61.3 mol % IB; rubbery material), with relatively narrow molecular weight distributions provided direct evidence of the presence of labile chlorine atoms at both ends of the macroinitiator capable of initiation of cationic polymerization of IB. One glass‐transition temperature (Tg), 104.5 °C, was observed for the aforementioned triblock copolymer, and the pentablock copolymer containing 61.3 mol % IB showed two well‐defined Tg's: −73.0 °C for PIB and 95.6 °C for the PS–PMMA blocks. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3823–3830, 2005
Electrosyntheses of high‐quality poly(5‐nitroindole) films in boron trifluoride diethyl etherate containing additional diethyl ether
Authors: Xu Jingkun , Zhou Weiqiang , Hou Jian , Pu Shouzhi , Yan Liushui , Wang Jingwu 
Published: July 2005

AbstractHigh‐quality poly(5‐nitroindole) (PNP) films were synthesized electrochemically by the direct anodic oxidation of 5‐nitroindole in boron trifluoride diethyl etherate (BFEE) containing additional 10% diethyl ether (EE) (by volume). The addition of EE to BFEE could improve the solubility of the monomer. The oxidation potential onset of 5‐nitroindole in this medium was measured to be only 1.04 V versus a saturated calomel electrode (SCE), which was much lower than that determined in acetonitrile and 0.1 mol L−1 tetrabutylammonium tetrafluoroborate (1.53 V vs SCE). PNP films obtained from this medium showed good electrochemical behavior and good thermal stability with a conductivity of 10−2 S cm−1; this indicated that BFEE containing 10% EE was a suitable medium for the electrosyntheses of PNP films. Structural studies showed that the polymerization of the 5‐nitroindole ring occurred at the 2,3‐position. As‐formed PNP films were thoroughly soluble in the strong polar organic solvent dimethyl sulfoxide and partly soluble in tetrahydrofuran or acetone. Fluorescent spectral studies indicated that PNP was a good green‐light emitter, with excitation and emission wavelengths of 420 and 550 nm, respectively. To the best of our knowledge, this is the first time that nitro‐group‐substituted high‐quality conducting polymer films have been electrodeposited. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3986–3997, 2005
Crosslinked sulfonated polyimide networks as polymer electrolyte membranes in fuel cells
Authors: Sundar Saimani , Jang Wonbong , Lee Choonkeun , Shul Yonggun , Han Haksoo 
Published: July 2005

AbstractSulfonated polyimides with tertiary nitrogen in the polymer backbone were synthesized with 1,4,5,8‐naphthalenetetracarboxylic dianhydride, 4,4′‐diaminobiphenyl 2,2′‐disulfonic acid, 2‐bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane, and diaminoacrydine hemisulfate. They were crosslinked with a series of dibromo alkanes to improve the hydrolytic stability. The crosslinked sulfonated polyimide films were characterized for their thermal stability, ion‐exchange capacity (IEC), water uptake, hydrolytic stability, and proton conductivity. All the sulfonated polyimides had good thermal stability and exhibited a three‐step degradation pattern. With an increase in the alkyl chain length of the crosslinker, IEC decreased as 1.23 > 1.16 > 1.06 > 1.01, and the water uptake decreased as 7.29 > 6.70 > 6.55 > 5.63. The order of the proton conductivity of the crosslinked sulfonated polyimides at 90 °C was as follows: polyimide crosslinked with dibromo butane (0.070) > polyimide crosslinked with dibromo hexane (0.055) > polyimide crosslinked with dibromo decane (0.054). The crosslinked polyimides showed higher hydrolytic stability than the uncrosslinked polyimides. Between the crosslinked polyimides, the hydrolytic stability decreased with an increase in the alkyl chain length of the crosslinker. The crosslinked and uncrosslinked sulfonated polyimides exhibited almost the same proton conductivities. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2370–2379, 2005
New way of presenting the universal calibration of gel permeation chromatography to include macromolecules with very high segment density
Authors: Papanagopoulos Dimitrios 
Published: July 2005

AbstractThe universal calibration of gel permeation chromatography presents deviations when star‐shaped polymers are used, especially when they present high segment density. Polymers presenting high segment density also have higher values of Flory's parameter Φ than the corresponding flexible, linear polymers. This deviation disappears if we express the hydrodynamic volume of the polymers with the quantity [η]M/Φ (where [η] is the intrinsic viscosity and M is the molecular mass) instead of the commonly used quantity [η]M. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2388–2391, 2005
Quantum properties of complete solutions for a new noncentral ring‐shaped potential
Authors: Dong Shi‐Hai , Chen Chang‐Yuan , Lozada‐Cassou M. 
Published: July 2005

AbstractWe propose a new exactly solvable ring‐shaped potential V(r,θ) = −(α/r) + (σ/r2) + β cos2θ/(r2sin2θ). The exact bound‐state solutions are presented explicitly. The creation and annihilation operators are established directly from the normalized radial wave functions. We present two important recurrence relations among the diagonal matrix elements and obtain some explicit expressions of mean values of rk (8 ≥ k ≥ −11). The exact form of continuum states is also obtained analytically. Comments are made on the calculation formula of phase shifts and the analytical properties of the scattering amplitude. It is interesting to find that the exact form of continuum states will reduce to that of the bound states at the poles of the scattering amplitude. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
A bio‐inspired approach for regulating and measuring visco‐elastic properties of a robot arm
Authors: Zollo Loredana , Dipietro Laura , Siciliano Bruno , Guglielmelli Eugenio , Dario Paolo 
Published: July 2005

AbstractThis work focuses on interaction control of robot manipulators in unstructured environments, with special regard for situations of unpredictable contact/noncontact transitions. It is basically addressed to those environments where a high level of robot adaptability is required and no information on the geometry of the environment is available. By pointing out the main limitations of standard interaction control schemes in managing situations of contact/noncontact transitions, this paper proposes a new control solution that is inspired by the biological model of motor control in voluntary movements. It consists of a combination of a feedforward loop and a proportional‐derivative plus gravity compensation control in the feedback loop. The control law is named coactivation‐based compliance control in the joint space since a unique function, called coactivation function, is evaluated for regulating robot visco‐elasticity in an unpredictably variable environment. It resumes the mechanism of adjustable visco‐elastic properties acting on the agonist and antagonist muscles of a human arm. The work also proposes a methodology for evaluating performance of interaction control schemes that is based on stiffness graphical representation through ellipses. The method replicates the experimental setup used in neuroscience to measure stiffness in human limbs. It is regarded as a powerful tool for evaluating robot behavior over space and time, since it allows both a visual representation of stiffness variation during motion and a quantitative measure of robot performance. It is shown how the method can be used to evaluate a control scheme and how it can provide indications to improve a control law. In this paper, an application to the standard compliance control in the joint space and the coactivation‐based compliance control is presented. © 2005 Wiley Periodicals, Inc.
Collision‐free control of robotic manipulators in the task space
Authors: Galicki Mirosław 
Published: July 2005

AbstractThis paper addresses the problem of position control of robotic manipulators in the task space with obstacles. A computationally simple class of task space regulators consisting of a transpose Jacobian controller plus an integral term including the task error and the gradient of a penalty function generated by obstacles is proposed. The Lyapunov stability theory is used to derive the control scheme. Through the use of the exterior penalty function approach, collision avoidance of the robot with obstacles is ensured. The performance of the proposed control strategy is illustrated through computer simulations for a direct‐drive arm of a SCARA type manipulator operating in both an obstacle‐free task space and a task space including obstacles. © 2005 Wiley Periodicals, Inc.