bluuebunny/crossref_metadata_2025 huggingface dataset:
Tuning the Decay Time of Lanthanide‐Based Near Infrared Luminescence from Micro‐ to Milliseconds through d→f Energy Transfer in Discrete Heterobimetallic Complexes
Authors: Torelli Stéphane , Imbert Daniel , Cantuel Martine , Bernardinelli Gérald , Delahaye Sandra , Hauser Andreas , Bünzli Jean‐Claude G. , Piguet Claude
Published: March 2005

Inert and optically active pseudo‐octahedral CrIIIN6 and RuIIN6 chromophores have been incorporated by self‐assembly into heterobimetallic triple‐stranded helicates HHH‐[CrLnL3]6+ and HHH‐[RuLnL3]5+. The crystal structures of [CrLnL3](CF3SO3)6 (Ln=Nd, Eu, Yb, Lu) and [RuLnL3](CF3SO3)5 (Ln=Eu, Lu) demonstrate that the helical structure can accommodate metal ions of different sizes, without sizeable change in the intermetallic M⋅⋅⋅Ln distances. These systems are ideally suited for unravelling the molecular factors affecting the intermetallic nd→4f communication. Visible irradiation of the CrIIIN6 and RuIIN6 chromophores in HHH‐[MLnL3]5/6+ (Ln=Nd, Yb, Er; M=Cr, Ru) eventually produces lanthanide‐based near infrared (NIR) emission, after directional energy migration within the complexes. Depending on the kinetic regime associated with each specific d–f pair, the NIR luminescence decay times can be tuned from micro‐ to milliseconds. The origin of this effect, together with its rational control for programming optical functions in discrete heterobimetallic entities, are discussed.
Redefining the boundaries of the hippocampal CA2 subfield in the mouse using gene expression and 3‐dimensional reconstruction
Authors: Lein Edward S. , Callaway Edward M. , Albright Thomas D. , Gage Fred H.
Published: March 2005

The morphology of neurons in the main divisions of the hippocampal complex allow the easy identification of granule cells in the dentate gyrus and pyramidal cells in the CA1 and CA3 regions of Ammon's horn. However, neurons in the CA2 subfield have been much more difficult to reliably identify. We have recently identified a set of genes whose expression is restricted to either the dentate gyrus, CA1, CA2, or CA3. Here we show that these genes have an essentially nonoverlapping distribution throughout the entire septotemporal extent of the hippocampus. 3‐Dimensional reconstruction of serial sections processed for in situ hybridization of mannosidase 1, alpha (CA1), bcl‐2‐related ovarian killer protein (CA3), and Purkinje cell protein 4 (dentate gyrus + CA2) was used to define the boundaries of each subregion throughout the entire hippocampus. The boundaries observed for these three genes are recapitulated across a much larger set of genes similarly enriched in specific hippocampal subregions. The extent of CA2 defined on the basis of gene expression is somewhat larger than that previously described on the basis of structural anatomical criteria, particularly at the rostral pole of the hippocampus. These results indicate that, at least at the molecular level, there are robust, consistent genetic boundaries between hippocampal subregions CA1, CA2, CA3, and the dentate gyrus, allowing a redefinition of their boundaries in order to facilitate functional studies of different neuronal subtypes in the hippocampus. J. Comp. Neurol. 485:1–10, 2005. © 2005 Wiley‐Liss, Inc.
Effect of initial oxygen concentration and film oxygen transmission rate on the quality of fresh‐cut romaine lettuce
Authors: Kim Ji Gang , Luo Yaguang , Tao Yang , Saftner Robert A , Gross Kenneth C
Published: March 2005

Modified atmosphere packaging (MAP) is widely used to maintain the quality of fresh‐cut produce by matching the oxygen transmission rate (OTR) of the packaging film to the respiration rate of the packaged product. The effect of the interaction between film OTR and the initial headspace O2 on quality of fresh‐cut vegetables has not previously been reported. Romaine lettuce leaves were sliced, washed, dried and packaged with film OTRs of 8.0 and 16.6 pmol s−1 m−2 Pa−1, and with initial headspace O2 of 0, 1, 2.5, 10 and 21 kPa. Packages were hermetically sealed and stored at 5 °C for up to 14 days. For samples packaged in 16.6 OTR film, increasing the initial headspace O2 concentration delayed O2 depletion within the packages, hastened the onset and increased the intensity of discoloration, and inhibited the development of CO2 injury, acetaldehyde and ethanol accumulation, off‐odors and electrolyte leakage. With 8.0 OTR‐packaged lettuce pieces, ≤1 kPa initial headspace O2 treatments induced an essentially anaerobic environment within the packages and increased acetaldehyde and ethanol accumulation and off‐odor development. Increasing the initial O2 concentration above 1 kPa in 8.0 OTR packages transiently increased O2 concentrations and reduced fermentative volatile production, off‐odors, electrolyte leakage and CO2 injury. Regardless of initial headspace O2 concentration, all 16.6 OTR‐packaged samples had severe discoloration after 14 days of storage. Quality was better maintained in 8.0 OTR‐packaged lettuce pieces as the initial headspace O2 concentration was increased. A 21 kPa initial O2 treatment of 8.0 OTR‐packaged lettuce maintained good quality throughout storage and had the best overall quality score. Copyright © 2005 Society of Chemical Industry
Wilson's disease in children: 37-Year experience and revised King's score for liver transplantation
Authors: Dhawan Anil , Taylor Rachel M. , Cheeseman Paul , De Silva Pamela , Katsiyiannakis Leah , Mieli-Vergani Giorgina
Published: March 2005

Wilson's disease (WD) is a rare liver-based disorder of copper metabolism. Prognostic criteria described by our group in 1986 to predict death without transplantation have not been universally validated. The clinical features of 88 children were reviewed, retrospectively in 74 and prospectively in 14. Data from the retrospectively recruited patients that died or survived on long-term chelation were used to evaluate the validity of our old scoring system and to devise a new prognostic index, then assessed in the 14 prospectively recruited patients. Using the old scoring system, 5 children scoring ≥ 7, the cutoff value for death without transplantation, survived, whereas 4 scoring ≤ 7 died (sensitivity 87% and specificity 90%). A new index based on serum bilirubin, international normalized ratio, aspartate aminotransferase (AST), and white cell count (WCC) at presentation identified a cutoff score of 11 for death and proved to be 93% sensitive and 98% specific, with a positive predictive value of 88%. When the new index was evaluated prospectively in 14 patients, it predicted the need for transplantation in only the 4 who required it, although 1 child with a score of 11 survived on medical treatment. In conclusion, the new Wilson Index is more sensitive and specific in predicting mortality without transplantation than the old scoring system, but needs to be validated in a larger number of patients. (Liver Transpl 2005;11:441–448.)
Liver transplant in a patient with a ventriculoperitoneal shunt
Authors: Faybush Elisa , Mulligan David C. , Birch Barry D. , Sirven Joseph I. , Balan Vijayan
Published: March 2005

There are no published accounts of patients with ventriculoperitoneal shunts undergoing liver transplantation in the literature. Because patients with ventriculoperitoneal shunts are prone to infections, this may be a theoretical contraindication to transplantation. We present a case of a patient with cirrhosis who had a ventriculoperitoneal shunt placed many years prior to transplantation. The patient had no neurological complications and the shunt was intact and functioning. Prior to transplantation, the patient underwent a ventriculoperitoneal to ventriculopleural shunt conversion that was reversed posttransplantation. Apart from some minor complications, the patient has done remarkably well from a graft and neurological perspective. In conclusion, patients who have ventriculoperitoneal shunts may be considered for liver transplantation as the risk of infectious and neurological complications is low and there are no deleterious effects on graft survival. (Liver Transpl 2005;11:467–468.)
Classification and Prediction of Survival in Hepatocellular Carcinoma by Gene Expression Profiling
Authors: Marsh Wallis J. , Finkelstein Sydney D. , Schwartz Myron E. , Fiel Isabel M. , Dvorchik Igor
Published: March 2005

We analyzed global gene expression patterns of 91 human hepatocellular carcinomas (HCCs) to define the molecular characteristics of the tumors and to test the prognostic value of the expression profiles. Unsupervised classification methods revealed two distinctive subclasses of HCC that are highly associated with patient survival. This association was validated via 5 independent supervised learning methods. We also identified the genes most strongly associated with survival by using the Cox proportional hazards survival analysis. This approach identified a limited number of genes that accurately predicted the length of survival and provides new molecular insight into the pathogenesis of HCC. Tumors from the low survival subclass have strong cell proliferation and antiapoptosis gene expression signatures. In addition, the low survival subclass displayed higher expression of genes involved in ubiquitination and histone modification, suggesting an etiological involvement of these processes in accelerating the progression of HCC. In conclusion, the biological differences identified in the HCC subclasses should provide an attractive source for the development of therapeutic targets (e.g., HIF1a) for selective treatment of HCC patients. Supplementary material for this article can be found on the Hepatology Web site (
http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html
) Copyright 2004 American Association for the Study of Liver Diseases. Hepatology. 2004 Sep;40(3):667–76.
Hepatic vein anatomy of the medial segment for living donor liver transplantation using extended right lobe graft
Authors: Hwang Shin , Lee Sung-Gyu , Choi Sang-Tae , Moon Deok-Bog , Ha Tae-Yong , Lee Young-Joo ng , Park Kwang-Min , Kim Ki-Hun , Ahn Chul-Soo , Kim Keon-Kuk , Kim Yeon-Dae
Published: March 2005

Hepatic vein anatomy (V4) of the medial segment (S4) has been a matter of concern since introduction of extended right lobe (ERL) graft. To assess risk of hepatic venous congestion (HVC) in ERL donors, we tried to newly classify V4 anatomy. We analyzed V4 anatomy of 328 living donor livers by using 3-dimensional reconstruction (3-DR) and volumetry of computed tomography (CT). Variations of V4 were divided into type A (middle hepatic vein [MHV] dominant: n = 142, 43.3%), type B (MHV-dominant, but enabling preservation of dorsal V4 branch [V4b]: n = 40, 12.2%), type C (mixed: n = 92, 28%), and type D (left hepatic vein dominant: n = 54, 16.5%). We analyzed the amount of HVC at S4 in 143 donor livers of right lobe (RL) and ERL grafts. Occlusion of MHV trunk induced HVC equivalent to 85.2%, 85.4%, 55.2%, and 35.4% of S4 volume and 34%, 33.9%, 20.3%, and 14.2% of left liver volume in livers of types A, B, C, and D, respectively. Tailored V4b preservation reduced HVC significantly in type B livers. Considering that functional capability may be decreased in HVC portion, functional hepatic resection rate (FHRR) of ERL graft procurement ranged as follows: 62.3%-75% in type A; 62.2%-75% and 62.2%-68.7% in type B with and without V4b preservation, respectively; 63.2%-70.7% in type C; and 61.8%-67.2% in type D. These results support the theory that these categories of V4 types are closely correlated with potential amount of HVC at S4, reflect the possibility of V4b preservation, and are compatible with CT findings. We believe that this V4 classification is applicable to assess donor V4 anatomy in practice. (Liver Transpl 2005;11:449–455.)
Finite element shakedown analysis of two‐dimensional structures
Authors: Garcea Giovanni , Armentano Giampaolo , Petrolo Salvatore , Casciaro Raffaele
Published: March 2005

In the present paper, the formulation proposed by Casciaro and Garcea (Comput. Meth. Appl. Mech. Eng., 2002; 191:5761–5792) and applied to the shakedown analysis of plane frames, is extended to the analysis of two‐dimensional flat structures in both the cases of plane‐stress and plane‐strain. The discrete formulation is obtained using a mixed finite element in which both stress and displacement fields are interpolated. The material is assumed to be elasto‐plastic and a linearization of the elastic domain is performed. The result is a versatile iterative scheme well suited to implementation in general purpose FEM codes. An extensive series of numerical tests is presented showing the reliability of the proposed formulation. Copyright © 2005 John Wiley & Sons, Ltd.
Charakterisierung von Plasma‐ Polymerfilmen mittels Flugzeit‐ Sekundärionen‐Massenspektrometrie (ToF‐SIMS). Characterisation Plasma‐Polymerfilms by Time‐of‐Flight Secondary Ion Mass Spectrometry (ToF‐SIMS)
Authors: von Gradowski M. , Wahl M. , Jacoby B. , Hilgers H. , Kopnarski M.
Published: March 2005

Die Flugzeit‐Sekundärionen‐Massenspektrometrie (ToF‐SIMS) ist eine sehr oberflächenempfindliche Analysemethode, die in vielen wissenschaftlichen und industriellen Bereichen eingesetzt wird. Sie dient zur Identifikation und Lokalisation des Elementinventars sowie der vorliegenden organischen und anorganischen Verbindungen auf Festkörperoberflächen.

Die Oberflächeninformationen werden aus Massenspektren gewonnen, in denen aufgrund der sehr hohen Massenauflösung des Instruments (m/Δm > 5.000) sogar zwischen Spezies gleicher nomineller Masse unterschieden werden kann. Zusätzlich können laterale Oberflächenverteilungen gemessen werden, die eine Lokalisation chemischer Spezies mit einer Auflösung < 1μm zulassen.

Mit Hilfe multivariater Modelle lassen sich die massenspektrometrischen Signale mit physikalischen Oberflächeneigenschaften (wie z. B. Benetzungsverhalten, Elementkonzentrationen, Reibverhalten etc.) korrelieren. Daraus können häufig entscheidende Hinweise über die Funktion der untersuchten Oberflächenstruktur abgeleitet werden. Die Flugzeit‐Sekundärionen‐Massenspektrometrie wird damit zu einem unverzichtbaren Hilfsmittel für die Entwicklung funktionaler Oberflächen, die wiederum Grundlage vieler neuer und innovativer Produkte sind.
Serum markers of angiogenesis and myocardial ultrasonic tissue characterization in patients with dilated cardiomyopathy
Authors: Ohtsuka Tomoaki , Inoue Katsuji , Hara Yuji , Morioka Norikatsu , Ohshima Kiyotaka , Suzuki Jun , Ogimoto Akiyoshi , Shigematsu Yuji , Higaki Jitsuo
Published: March 2005

Background and aims

It has been proven that a disturbance in angiogenesis contributes to the progression of myocardial interstitial fibrosis in idiopathic dilated cardiomyopathy (DCM). This study was designed to evaluate the relationship between serum activity of angiogenic factors and myocardial ultrasonic tissue characterization in patients with DCM.

Methods and results

We studied 30 patients with DCM and 15 healthy control subjects. Serum levels of vascular endothelial growth factor (VEGF), interleukin (IL)‐4 and IL‐13 were measured using enzyme‐linked immunosorbent assay. We determined calibrated myocardial integrated backscatter (IB) as the value of myocardial interstitial fibrosis using ultrasonic tissue characterization and also quantified the magnitude of cyclic variations in IB (CV‐IB). Serum levels of VEGF and IL‐13 were significantly higher in patients with DCM than in control subjects (both P<0.05). Calibrated IB was significantly higher and CV‐IB was markedly lower in patients with DCM than in control subjects (both P<0.01). In patients with DCM, the levels of IL‐13 significantly correlated with calibrated IB (r=0.520, P=0.018). In addition, there was a significant negative correlation between levels of VEGF and CV‐IB (r=−0.611, P=0.007).

Conclusion

The increase in serum VEGF and IL‐13 may be closely related to alterations in myocardial texture in DCM.
Children's Social Welfare in China, 1989–1997: Access to Health Insurance and Education
Authors: Adams Jennifer , Hannum Emily
Published: March 2005

Fundamental changes in China's finance system for social services have decentralized responsibilities for provision to lower levels of government and increased costs to individuals. The more localized, market-oriented approaches to social service provision, together with rising economic inequalities, raise questions about access to social services among China's children. With a multivariate analysis of three waves of the China Health and Nutrition Survey (1989, 1993 and 1997), this article investigates two dimensions of children's social welfare: health care, operationalized as access to health insurance, and education, operationalized as enrolment in and progress through school. Three main results emerge. First, analyses do not suggest an across-the-board decline in access to these child welfare services during the period under consideration. Overall, insurance rates, enrolment rates and grade-for-age attainment improved. Secondly, while results underscore the considerable disadvantages in insurance and education experienced by poorer children in each wave of the survey, there is no evidence that household socio-economic disparities systematically widened. Finally, findings suggest that community resources conditioned the provision of social services, and that dimensions of community level of development and capacity to finance public welfare increasingly mattered for some social services.
Health Finance in Rural Henan: Low Premium Insurance Compared to the Out-of-Pocket System
Authors: Jackson Sukhan , Sleigh Adrian C. , Peng Li , Xi-Li Liu
Published: March 2005

China's health reforms of the 1980s led to privatization of rural health care with adverse impact on farmers. A decade later a new rural co-operative medical scheme (RCMS), was piloted throughout many provinces to promote better equity. Although many schemes later collapsed owing to inadequate funding, some continue to the present. This article compares such a scheme with the out-of-pocket system in Henan province. We study the township hospitals, focusing on cost of services, utilization rates and impact of RCMS on hospitals' financial sustainability. Our results derive from monthly hospital records and a survey of four hospitals in two adjacent counties, one county with low-premium RCMS and the other with the out-of-pocket system.

All hospitals charged for preventive activities (such as antenatal care, immunization), an unfortunate consequence of limited government support. It was not clear that on average, the total cost of individual patient visits in RCMS hospitals was lower than non-RCMS hospitals. Farmers were generally unaware of their insurance entitlements, except the catastrophic illnesses for which there was a real benefit from refund of US$100 or more. Although the effect of the RCMS on hospital charges was unclear it was notable that the utilization rates in RCMS areas were twice those in non-RCMS.

We conclude that RCMS hospitals were better funded because of re-imbursements from the insurance scheme and therefore were more viable as sources of good health care. Thus, health care could become more equitable under RCMS than the out-ofpocket system. China is now beginning to test a revised form of RCMS with pooling at the county level, increased premiums (10 yuan per person) and increased government funding. However, it must be followed closely to determine the effect on rural services and health care costs for farmers.
Measuring Taiwanese Public Opinion on Taiwanese Independence
Authors: Fuh-sheng Hsieh John , Niou Emerson M.S.
Published: March 2005

Whether there will be a war between China and Taiwan depends very much upon whether Taiwan will declare independence. And given that Taiwan is a democracy now, public opinion on the issue will certainly affect the political leaders' decision to move one way or the other. Since the early 1990s, several competing methods have been used in surveys to study Taiwanese attitudes on the independence – unification issue. The existence of a large percentage of respondents with conditional preferences makes us realize that the traditional six-point or 11-point scale measures of preferences oversimplify the situation. In this article, we construct a new measure of preferences and show that it clearly outperforms the traditional methods.
Corruption and Market in Contemporary China. By YAN SUN. [Ithaca, NY: Cornell University Press, 2004. 272 pp. Hard cover $49.95, ISBN 0-8014-4284-2; paperback $21.00, ISBN 0-8-8014-8942-3.].
Authors: Wedeman Andrew
Published: March 2005

In Corruption and Market in Contemporary China, Yan Sun seeks to describe, in qualitative terms, corruption in post-Mao China and assess its consequences. Corruption is not, she argues, a unitary phenomena but rather consists of a variety of different forms of malfeasance whereby officials use the public authority granted them by right of their positions to seek private gains. Differences in form imply differences in result. Thus, we might presume it makes a difference if an official loots the treasury and absconds to the Cayman Islands or if she accepts a minor bribe in return for granting a business licence to an entrepreneur who goes on to establish a flourishing business empire.

In trying to describe Chinese corruption, Sun faces a Herculean task. Since 1979, the Ministry of Supervision and the Party's Discipline Inspection Commission have disciplined three million cadres and the judicial Procuratorate has prosecuted one million cases of economic and disciplinary crime. Even given detailed and systematic data, the task of cataloguing the multitudinous forms of corruption and then characterizing them into a manageable typology would be a formidable analytic task. Such data are, however, lacking. Sun is therefore forced to turn to case data drawn from a variety of compilations and collections. These data are problematic – as Sun recognizes – because of sampling error and selection bias.

Using her database (which consists of approximately 1,300 mostly senior-level cases), supplemented by data from official and unofficial Chinese sources, Sun breaks corruption down into two major categories, transactive and nontransactive, differentiating between exchanges between state officials and private interests (e.g. bribery), and the theft of state assets by officials (e.g. embezzlement). She then disaggregates these categories into 11 subcategories and 27 specific forms. She further differentiates between two periods (pre-1992 and post-1992) and breaks corruption down along regional lines.
China, Sex and Prostitution. By ELAINE JEFFREYS. [London and New York: Routledge Curzon, 2004. 212 pp. ISBN 0-415-31863-7.]
Authors: Remick Elizabeth J.
Published: March 2005

This book's primary theoretical targets are methodological problems and political biases in China studies, and it uses scholarly and administrative discourses about female prostitution in order to illustrate the field's shortcomings. As befits its embrace of the text-based “new humanities,” its sources are scholarly debates, police and government reports, and secondary sources rather than ethnographic fieldwork.

Jeffreys argues that China studies suffers from several problems. First, it has methodological deficiencies: China studies is dominated by scholars who wrongly claim to have access to the “truth” about China because of their linguistic skills; as “nation-translators” they produce positivist, realist, empiricist works disconnected from the theoretically-oriented “new humanities.” Moreover, scholars who do attempt to apply postmodern or postcolonial theories to China engage it as an object that can illustrate their theories, never as a subject that can generate theory. In short, Anglophone authors privilege the metropolitan discourse and ignore what Chinese people have to say. Secondly, the field suffers from political biases: China Studies is still mired in a Cold War ideological framework in which scholars accept the word of the CCP only “to turn it back on the CCP … to show how and where the CCP and Chinese Marxism have failed” (p. 41). Their analytical reliance on the state/civil society dichotomy emphasizes the power of the state over and above society, with the implication that only non-state actors can speak truthfully. This “preclude[s] the possibility that there might be anything positive or productive about the operation of power in China” (p. 41). Jeffreys advocates replacing the state/civil society dichotomy with the Foucauldian notion of “governmentality,” which forces one to examine the complex historical background and administrative networks in which government officials are enmeshed, and which creates the limits of the possible for them. Lastly, she argues that international NGOs and metropolitan feminists are fundamentally misguided when they push the Chinese government to recognize the validity of sex work because they have no idea what the actual ramifications of this would be in the Chinese context. Such a policy would, unlike the commonsense efforts of the Chinese police, make life worse, not better, for prostitutes.
In The Name of Harmony and Prosperity: Labor and Gender Politics in Taiwan's Economic Restructuring. By ANRU LEE. [New York: State University of New York Press 2004. xvi+196pp. $45.00. ISBN 0-7914-6033-9.]
Authors: Chen I-Ru
Published: March 2005

Anru Lee's In The Name of Harmony and Prosperity examines the labour and gender politics in the latest phase of Taiwan's economic restructuring. The author argues that the conventional wisdom that regards the interaction between culture and economy as a static relationship is problematic, and she sets out to develop a dialectic approach to culture and economy. Lee has collected a huge amount of data from fieldwork interviews and observational skills, and the research outcome further affirms the idea that the cultural dimension has to be taken into account in order to understand fully Taiwan's economic success. The book is divided into seven broad chapters: Taiwan's great transformation; From sunrise to sunset; The waning of a hard work ethic; The meaning of work; Between filial daughter and loyal sister; Guests from the tropics; and Bringing the global and the local.

The author begins with a general description of Taiwan's economic transformation in recent decades, and then focuses on the latest changes in the textile industry in Homei, analysing how the local residents responded to and engaged in the changes. In chapter two, “From sunrise to sunset,” Lee highlights the significance of the cultural ideal in Taiwan's decentralized production system. She argues that the “black-hand becoming boss” (heishou bian toujia) cultural notion helps to thwart the development of class consciousness in Taiwan's society and adds legitimacy to the factory owner's complaint of labour shortages and society's declining work ethic. Chapter three, “The waning of a hard work ethic,” shows the paradoxical nature of the claims about the shortage of labour and explores the New Generation moral discourse, which involves a network value of hard work, equal opportunity and social mobility. Chapter four presents the life stories of three women from different generations and discusses the meaning of work to them. The author argues that not only gender but also other social institutions (such as the patrilineal kinship system, family and relations in production) have to be examined in order to fully comprehend the relationship between the economy and the formation of women's subjectivity.
Framework to evaluate the worth of hydraulic conductivity data for optimal groundwater resources management in ecologically sensitive areas
Authors: Feyen Luc , Gorelick Steven M.
Published: March 2005

We propose a framework that combines simulation optimization with Bayesian decision analysis to evaluate the worth of hydraulic conductivity data for optimal groundwater resources management in ecologically sensitive areas. A stochastic simulation optimization management model is employed to plan regionally distributed groundwater pumping while preserving the hydroecological balance in wetland areas. Because predictions made by an aquifer model are uncertain, groundwater supply systems operate below maximum yield. Collecting data from the groundwater system can potentially reduce predictive uncertainty and increase safe water production. The price paid for improvement in water management is the cost of collecting the additional data. Efficient data collection using Bayesian decision analysis proceeds in three stages: (1) The prior analysis determines the optimal pumping scheme and profit from water sales on the basis of known information. (2) The preposterior analysis estimates the optimal measurement locations and evaluates whether each sequential measurement will be cost‐effective before it is taken. (3) The posterior analysis then revises the prior optimal pumping scheme and consequent profit, given the new information. Stochastic simulation optimization employing a multiple‐realization approach is used to determine the optimal pumping scheme in each of the three stages. The cost of new data must not exceed the expected increase in benefit obtained in optimal groundwater exploitation. An example based on groundwater management practices in Florida aimed at wetland protection showed that the cost of data collection more than paid for itself by enabling a safe and reliable increase in production.
On the coupling between molecular diffusion and solvation shell exchange
Authors: Møller Klaus B. , Rey Rossend , Masia Marco , Hynes James T.
Published: March 2005

The connection between diffusion and solvent exchanges between first and second solvation shells is studied by means of molecular dynamics simulations and analytic calculations, with detailed illustrations for water exchange for the Li+ and Na+ ions, and for liquid argon. First, two methods are proposed which allow, by means of simulation, to extract the quantitative speed-up in diffusion induced by the exchange events. Second, it is shown by simple kinematic considerations that the instantaneous velocity of the solute conditions to a considerable extent the character of the exchanges. Analytic formulas are derived which quantitatively estimate this effect, and which are of general applicability to molecular diffusion in any thermal fluid. Despite the simplicity of the kinematic considerations, they are shown to well describe many aspects of solvent exchange/diffusion coupling features for nontrivial systems.
Synchrotron-based investigations of the nature and impact of iron contamination in multicrystalline silicon solar cells
Authors: Buonassisi Tonio , Istratov Andrei A. , Heuer Matthias , Marcus Matthew A. , Jonczyk Ralf , Isenberg Joerg , Lai Barry , Cai Zhonghou , Heald Steven , Warta Wilhelm , Schindler Roland , Willeke Gerhard , Weber Eicke R.
Published: March 2005

Synchrotron-based microprobe techniques were used to obtain systematic information about the size distribution, spatial distribution, shape, electrical activity, chemical states, and origins of iron-rich impurity clusters in multicrystalline silicon (mc-Si) materials used for cost-effective solar cells. Two distinct groups of iron-rich cluster have been identified in both materials: (a) the occasional large (diameter ⩾1μm) particles, either oxidized and/or present with multiple other metal species reminiscent of stainless steels or ceramics, which are believed to originate from a foreign source such as the growth surfaces, production equipment, or feedstock, and (b) the more numerous, homogeneously distributed, and smaller iron silicide precipitates (diameter ⩽800nm, often ⩽100nm), originating from a variety of possible formation mechanisms involving atomically dissolved iron in the melt or in the crystal. It was found that iron silicide nanoprecipitates account for bulk Fe concentrations as high as 1014–1015cm−3 and can have a large negative impact on device performance because of their high spatial density and homogeneous distribution along structural defects. The large (diameter ⩾1μm) particles, while containing elevated amounts—if not the majority—of metals, are low in spatial density and thus deemed to have a low direct impact on cell performance, although they may have a large indirect impact via the dissolution of Fe, thus assisting the formation of iron silicide nanoprecipitates. These results demonstrate that it is not necessarily the total Fe content that limits the mc-Si device performance but the distribution of Fe within the material.
Transformation of nanodiamond into carbon onions: A comparative study by high-resolution transmission electron microscopy, electron energy-loss spectroscopy, x-ray diffraction, small-angle x-ray scattering, and ultraviolet Raman spectroscopy
Authors: Mykhaylyk Oleksandr O. , Solonin Yurii M. , Batchelder David N. , Brydson Rik
Published: March 2005

The structural properties of both nanodiamond particles synthesized by detonation and the products of their transformation into carbon onions via vacuum annealing at 1000 and 1500°C have been studied using high-resolution transmission electron microscopy (HRTEM), electron energy-loss spectroscopy, x-ray diffraction (XRD), small-angle x-ray scattering (SAXS), and Raman spectroscopy. The advantages of UV Raman spectroscopy over visible Raman spectroscopy for the analysis of these carbon nanomaterials are demonstrated. It was found that the synthesized nanodiamond particles have a composite core-shell structure comprising an ordered diamond core covered by a disordered (amorphous) outer shell formed by the mixed sp2∕sp3 bonding of carbon atoms. The observed structure of the nanodiamond particles are comparable with the structure of the bucky diamond clusters comprising a diamond core and a reconstructed surface which stabilizes the cluster at the average diameter of ∼30Å, as predicted recently from theoretical studies. Assuming a spherical shape for the particles and employing a two-step boundary model of electron density distribution developed in this work to describe the SAXS patterns produced by the core-shell structure of the nanodiamond particles, it was evaluated that the average diameter of the core is ∼30Å and the average thickness of the shell is ∼8Å; values which are in agreement with results obtained from HRTEM and XRD measurements. A discrepancy between these results and average diamond crystallite size obtained from Raman spectra by applying the phonon confinement model (35–45Å) is discussed. It is hypothesized from analysis of broadening of the XRD diamond peaks that at the nanoscale under influence of the particle shape, which is not strictly of a cubic (or spherical) symmetry, a slight hexagonal distortion of the cubic diamond structure appears in the nanodiamond particles. The transformation of the nanodiamond into carbon onions proceeds from the amorphous outer shell of the particles inwards towards the particles’ diamond core. UV Raman spectroscopy effectively senses the initial stage of the transformation revealing a reconstruction of the mixed sp2∕sp3 bonding of carbon atoms located in the outer shell, into sp2-bonded carbon atoms similar to those in nanocrystalline graphite. It is shown that intershell distance in carbon onions formed from nanodiamonds depends on the temperature of the transformation and relates to the linear thermal expansion coefficient of the graphite structure along the stacking direction of the graphene layers (the c axis). In accordance with SAXS results, there is evidence for an increase of the average particle size of the synthesized nanodiamond [48(3)Å] after transformation into carbon onions [58(10)Å].
Adhesion between single-walled carbon nanotubes
Authors: Tang Tian , Jagota Anand , Hui Chung-Yuen
Published: March 2005

Continuum analysis and molecular simulations are carried out to study the adhesion between two identical single-walled carbon nanotubes. A critical radius Rmin=D∕Wflat is found below which the contact area is zero, where D is the effective bending stiffness of the nanotube, and Wflat is the work needed to separate two flat parallel graphite sheets of unit area in equilibrium. Using our theory, the change in the potential energy during the deformation is obtained and the theoretical result compares well with molecular simulations.
Structural and magnetic properties of NiMnSb/InGaAs/InP(001)
Authors: Koveshnikov A. , Woltersdorf G. , Liu J. Q. , Kardasz B. , Mosendz O. , Heinrich B. , Kavanagh K. L. , Bach P. , Bader A. S. , Schumacher C. , Rüster C. , Gould C. , Schmidt G. , Molenkamp L. W. , Kumpf C.
Published: March 2005

The structural and magnetic properties of NiMnSb films, 5–120 nm thick, grown on InGaAs/InP(001) substrates by molecular-beam epitaxy, were studied by x-ray diffraction, transmission electron microscopy (TEM), and ferromagnetic resonance (FMR) techniques. X-ray diffraction and TEM studies show that the NiMnSb films had the expected half-Heusler structure, and films up to 120 nm were pseudomorphically strained at the interface, greater than the critical thickness for this system, about 70 nm (0.6% mismatch to InP). No interfacial misfit dislocations were detected up to 85 nm, however, relaxation in the surface regions of films thicker than 40 nm was evident in x-ray reciprocal space maps. TEM investigations show that bulk, planar defects are present beginning in the thinnest film (10 nm). Their density remains constant but they gradually increase in size with increasing film thickness. By 40 nm these defects have overlapped to form a quasicontinuous network aligned closely with ⟨100⟩ in-plane directions. The associated strain fields and or compositional ordering from these defects introduced a reduction in crystal symmetry that influenced the magnetic properties. The in-plane and perpendicular FMR anisotropies are not well described by bulk and interface contributions. In thick films, the in-plane uniaxial and fourfold anisotropies increased with increasing film thickness. The lattice defects resulted in a large extrinsic magnetic damping caused by two-magnon scattering, an increase in the coersive field with increasing film thickness, and a lower magnetic moment (3.6 Bohr magnetons) compared to the expected value for the bulk crystals (4 Bohr magnetons).
Effects of hydrogen on positive charges in gate oxides
Authors: Zhao C. Z. , Zhang J. F.
Published: March 2005

Positive charge formation in gate oxides is a main source for the instability of the state-of-the-art metal-oxide-semiconductor device. Despite past efforts, the relation between hydrogenous species and positive charges is not fully understood. In this work, the effects of hydrogen on positive charges will be investigated at both elevated temperature (e.g., 400°C) and room temperature. At 400°C, it is found that hydrogen can convert some defects into hole traps. Three different types of positive charges have been reported recently. They are as-grown hole traps, anti-neutralization positive charges (ANPC), and cyclic positive charges (CPC). Although an exposure to hydrogen at 400°C neutralizes all three, impacts of hydrogen on these three types of defects are markedly different. After the hydrogen-induced neutralization, the defect responsible for ANPC is fully recovered and is the same as that in a fresh device. In contrast, the defect for CPC is not fully recovered and can be reactivated easily by stresses. The as-grown hole trap can be converted to ANPC through hydrogenation. At room temperature, it will be shown that there are two parallel processes for forming positive charges. One involves hydrogen and the other is through hole trapping. The relative importance of these two depends on the relative density of hydrogen against that of holes.
Fast microtomography using high energy synchrotron radiation
Authors: Di Michiel Marco , Merino Jose Manuel , Fernandez-Carreiras David , Buslaps Thomas , Honkimäki Veijo , Falus Peter , Martins Thierry , Svensson Olof
Published: March 2005

At the High Energy Beamline ID15A at the European Synchrotron Radiation Facility we have developed a fast three-dimensional x-ray microtomography system, which acquires a complete dataset in typically less than 10s. This unprecedented speed is achieved by combining a high efficiency phosphor screen, a reflecting microscope objective and a fast charge coupled device detector with the very intense high-energy white beam radiation provided by a wiggler source. The achieved spatial resolution is 2μm. The available x-ray energy spectrum spans from 20to250keV and can therefore be used for low and high Z materials. The spectrum can be modified by inserting different filters into the x-ray beam in order to optimize the signal-to-noise ratio and to avoid beam-hardening artifacts. Different phosphors with different energy sensitivity can be used. The very high speed allows in situ studies of systems evolving on the time scale of a few seconds or minutes. Three examples are given on sintering of metallic powders, solidification of binary alloys and liquid front propagation in granular materials.
Sm
(
Co
,
Cu
)
5
∕
Fe
exchange spring multilayer films with high energy product
Authors: Zhang J. , Takahashi Y. K. , Gopalan R. , Hono K.
Published: March 2005

The [Sm(Co,Cu)5∕Fe]6 multilayer film that was fabricated by annealing Cr[a-(Sm-Co)(9nm)∕Cu(xnm)∕Fe(5nm)∕Cu(xnm)]6∕Cr(x=0–0.75) multilayer has shown good in-plane texture and a high maximum energy product (BH)max of 32 MGOe with a coercivity of 7.24 kOe. The addition of the Cu layer between the a-d-SM-Co6 and Fe layers with optimum thickness increases the coercivity significantly, thereby improving the maximum energy product. The single-phase behavior and the irreversible rotation in the demagnetization process indicates strong exchange coupling between the Sm(Co,Cu)5 and Fe layers.
Dielectric measurement of ferroelectric Sr0.61Ba0.39Nb2O6 single crystal fiber using cavity perturbation method
Authors: Huang Chuanyong , Bhalla Amar S. , Lanagan M. T. , Cross L. Eric , Guo Ruyan
Published: March 2005

The nonlinear dielectric property of the ferroelectric Sr0.61Ba0.39Nb2O6 (SBN) crystal is essential to device application at various frequency ranges. The dielectric constant of the SBN single crystal fiber was investigated at x band microwave frequency using the resonant cavity perturbation method. It was found that compared with large and decreasing dielectric constant of SBN at low frequency, the dielectric property of the SBN crystal at x band frequency was smaller with similar value controlled by dipole orientation or atomic vibration.
Protein kinase casein kinase 2 holoenzyme produced ectopically in human cells can be exported to the external side of the cellular membrane
Authors: Rodríguez Fernando , Allende Catherine C. , Allende Jorge E.
Published: March 2005

Ectokinases can phosphorylate extracellular proteins and external domains of membrane proteins influencing cell adhesion, movement, and cellular interactions. An ectokinase with the properties of casein kinase 2 (CK2) has been previously described, but little is known about the structural characteristics that allow this enzyme to be exported from the cell. Transfection of human embryonic kidney-293 cells with cDNAs coding for the catalytic (CK2α or CK2α′) and regulatory (CK2β) subunits with hemaglutinin tags allowed us to study the export of ectopically synthesized enzyme. When the catalytic (CK2α or CK2α′) and the CK2β regulatory subunits are cotransfected, the tetrameric enzyme composed of both subunits (holoenzyme) is detected outside the cell. This observation has been confirmed by assaying protein kinase activity in immunoprecipitates obtained with antihemaglutinin antibody by using a CK2-specific peptide substrate and by Western blots as well as by immunofluorescence of nonpermeabilized cells. Transfection with cDNA of catalytic or regulatory subunit alone does not result in export of these subunits. A study of the kinetics of appearance of the ectopically synthesized protein at different times after transfection indicates that a 5- to 7-h delay after the synthesis of the protein before it appears in the extracellular compartment. Using mutations of CK2α that eliminate phosphorylating activity [CK2α(Asp-156-Ala)] or that make it less sensitive to heparin inhibition [CK2α(Lys-75-Glu,Lys-76-Glu)] demonstrated that these mutations do not prevent the holoenzyme to be exported from the cells.
Design principles of chemical penetration enhancers for transdermal drug delivery
Authors: Karande Pankaj , Jain Amit , Ergun Kaitlin , Kispersky Vincent , Mitragotri Samir
Published: March 2005

Chemical penetration enhancers (CPEs) are present in a large number of transdermal, dermatological, and cosmetic products to aid dermal absorption of curatives and aesthetics. This wide spectrum of use is based on only a handful of molecules, the majority of which belong to three to four typical chemical functionalities, sporadically introduced as CPEs in the last 50 years. Using >100 CPEs representing several chemical functionalities, we report on the fundamental mechanisms that determine the barrier disruption potential of CPEs and skin safety in their presence. Fourier transform infrared spectroscopy studies revealed that regardless of their chemical make-up, CPEs perturb the skin barrier via extraction or fluidization of lipid bilayers. Irritation response of CPEs, on the other hand, correlated with the denaturation of stratum corneum proteins, making it feasible to use protein conformation changes to map CPE safety
in vitro
. Most interestingly, the understanding of underlying molecular forces responsible for CPE safety and potency reveals inherent constraints that limit CPE performance. Reengineering this knowledge back into molecular structure, we designed >300 potential CPEs. These molecules were screened
in silico
and subsequently tested
in vitro
for molecular delivery. These molecules significantly broaden the repertoire of CPEs that can aid the design of optimized transdermal, dermatological, and cosmetic formulations in the future.
Physical activity interventions in the prevention and treatment of paediatric obesity: systematic review and critical appraisal
Authors: Reilly John J. , McDowell Zoe C.
Published: March 2005

Interventions for prevention and treatment of childhood obesity typically target increases in physical activity and, more recently, reductions in physical inactivity (sedentary behaviour such as television viewing). However, the evidence base for such strategies is extremely limited. The main aim of the present review was to update the systematic review and critical appraisal of evidence in the light of the recent rapid expansion of research in this area. Randomised controlled trials (RCT) that targeted activity or inactivity, that followed up children or adolescents for at least 1 year and that included an objective weight-related outcome measure were included. Trials were appraised using previously published criteria (Harbour & Miller, 2001), and literature search strategies described previously (Reillyet al. 2002) were updated to May 2002. A total of four new RCT, two new systematic reviews and one meta-analysis were identified. The evidence base has increased markedly since the completion of earlier reviews, although high-quality evidence is still lacking. The evidence on childhood obesity prevention is not encouraging, although promising targets for prevention are now clear, notably reduction in sedentary behaviour. There is stronger evidence that targeting activity and/or inactivity might be effective in paediatric obesity treatment, but doubts as to the generalisability of existing interventions, and the clinical relevance of the interventions is unclear. Further research in settings outside the USA is urgently needed, and two ongoing RCT in Scotland are summarised.