bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural and energetic aspects of the differences between real and predicted polymorphs
Authors: Svärd M. , Rasmuson Å. C.
Published: June 2010

In crystal structure prediction simulations based on lattice energy minimization, usually hundreds of structures within a reasonable range of lattice energy and density are found, whereas in practice, it is very rare to find more than a few polymorphs of the same compound. In the work presented here, this discrepancy is investigated from a structural and energetic point of view. 56 crystal structures of 26 polymorphic mono‐ and disubstituted aromatic compounds, extracted from the Cambridge Structural Database, have been analysed with respect to inter‐polymorphic structural similarity. For comparison, potential crystal packing arrangements of the substances have been predicted with molecular mechanics simulations using a generic force field. The predicted structures are analysed with respect to structural features and similarity, and with respect to the number of structures and their lattice energy. It is found that the real polymorphs studied in this work tend to be structurally quite dissimilar with regard to hydrogen bonding and spatial packing of structural motifs, while many of the predicted structures of a given compound are very similar to each other. The results suggest that structure and lattice energy alone cannot explain why so few polymorphs are found in practice compared to the very large numbers predicted in simulations. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thinnest Two‐Dimensional Nanomaterial—Graphene for Solar Energy
Authors: Hu Yun Hang , Wang Hui , Hu Bo
Published: June 2010

Graphene is a rapidly rising star in materials science. This two‐dimensional material exhibits unique properties, such as low resistance, excellent optical transmittance, and high mechanical and chemical stabilities. These exceptional advantages possess great promise for its potential applications in photovoltaic devices. In this Review, we present the status of graphene research for solar energy with emphasis on solar cells. Firstly, the preparation and properties of graphene are described. Secondly, applications of graphene as transparent conductive electrodes and counter electrodes are presented. Thirdly, graphene‐based electron‐ (or hole) accepting materials for solar energy conversion are evaluated. Fourthly, the promoting effect of graphene on photovoltaic devices and the photocatalytic property of graphene–semiconductor composites are discussed. Finally, the challenges to increase the power conversion efficiency of graphene‐based solar cells are explored.
Relationship of microparticles to progenitor cells as a measure of vascular health in a diabetic population
Authors: Curtis Anne M. , Zhang Lifeng , Medenilla Elizabeth , Gui Ming , Wilkinson Patrick F. , Hu Erding , Giri Jay , Doraiswamy Vijay , Gunda Sampath , Burgert Mark E. , Moore Jonni S , Edelberg Jay M. , Mohler Emile R.
Published: June 2010

Objective:

Quantitative measures are needed to identify diabetic patients at higher risk for CV events. Cell‐derived microparticles (MPs) are submicron membrane vesicles released from activated cells that are indicative of cell damage. Progenitor cells (PCs) including proangiogenic cells (PACs), often termed endothelial progenitor cells (EPCs), are mediators of reparative capacity. We examined whether the relationship of MPs to PCs/PACs could be used as an improved and clinically feasible index of vascular pathology.

Methods and Results:

Plasma samples were collected from patients with early‐stage (ES, Diagnosis < 1year) and long‐term (LT, Diagnosis > 5 years,) Type 2 diabetes and compared with age related healthy subjects (H). PC and MP subtypes were measured by a combination of flow cytometry and ELISA‐based methods. The ratio of procoagulant MPs/CD34+ PCs proved a valuable index to distinguish between subject groups (P = 0.01). This index of compromised vascular function was highest in the LT group despite intensive statin therapy and was more informative than a range of soluble protein biomarkers.

Conclusions:

This is the first report of a relationship between MPs and PCs in Type 2 diabetes. This ratio may provide a quantitative and clinically feasible measurement of vascular dysfunction and cardiovascular risk in patients with diabetes. © 2010 International Clinical Cytometry Society
Nichtlinearer Erdbebennachweis von Gebäuden aus Kalksandsteinmauerwerk nach DIN EN 1998
Authors: Butenweg Christoph , Gellert Christoph , Schlundt Andreas
Published: June 2010

Die Erdbebensicherheit von Gebäuden aus Kalksandsteinmauerwerk ist aktuell nach DIN 4149 mit linearen Verfahren nachzuweisen. Dies führt in der praktischen Anwendung zu großen Problemen, da selbst traditionell übliche Grundrisse teilweise nicht mehr ohne zusätzliche Maßnahmen nachweisbar sind. Zur Lösung dieser Problematik wurden von der deutschen Mauerwerksindustrie auf nationaler und europäischer Ebene Forschungsprojekte initiiert, deren Ergebnisse in Form von statisch nichtlinearen Verfahren Eingang in den Nationalen Anhang zur DIN EN 1998‐1 [12] gefunden haben. Mit den Verfahren wird die Nachweissituation zukünftig grundlegend verbessert, da mit diesen die Tragwerksreserven wesentlich besser ausgenutzt werden können. Im Folgenden wird die Anwendung der Verfahren am Beispiel einer Reihenhauszeile aus Kalksandsteinmauerwerk demonstriert. Der Nachweis der Reihenhäuser wurde im Rahmen einer Zustimmung im Einzelfall, die vom Bundesverband Kalksandsteinindustrie eV in Hannover koordiniert wurde, durch unabhängige Gutachter und die Bauaufsicht eingehend geprüft und für richtig befunden. Die Durchführung des Nachweises erfolgte auf Grundlage eines an der RWTH Aachen entwickelten neuen Nachweiskonzeptes. Die baupraktische Anwendbarkeit und einfache Nachvollziehbarkeit dieses Konzepts ist durch eine softwaretechnische Umsetzung sichergestellt.

Nonlinear seismic safety verification of calcium silicate masonry buildings according to DIN EN 1998. The standard procedure for the seismic safety verification of masonry buildings according to the seismic design provisions of the German seismic building code DIN 4149 is traditionally based on a linear design concept. The practical application of the linear design concept leads to major difficulties, even for ground plan configurations which have already proven their stability in past earthquakes. This challenging situation was the starting point for intensive research activities on national and European level, initiated by the German masonry industry. The most important result of the activities was the development of an innovative nonlinear design concept, which is already incorporated in the National Annex of DIN EN 1998‐1. The new concept, which fully utilizes the nonlinear bearing reserves, will solve the difficulties in the seismic design of masonry build ings. The application of the concept will be demonstrated on the example of a typical terraced house made of calcium silicate units. The design of the terraced house has been approved by national building authorities, because the new design concept is not part of the German earthquake code DIN 4149 yet. The concept, developed at the RWTH Aachen, was implemented into a software package. The software solution is easy to use and ensures the traceability of the nonlinear results in the engineering practice.
Verhalten von Mauerwerksbauten unter Erdbebeneinwirkung: Auswertung der Schäden des Albstadt‐Erdbebens vom 3. September 1978
Authors: Schwarz Jochen , Beinersdorf Silke , Langhammer Tobias , Leipold Mathias
Published: June 2010

Numerische Untersuchungen zum Verhalten von Mauerwerksbauten unter Erdbebeneinwirkung führen oft zu pessimistischen Schadensprognosen, welche im Gegensatz zu den Beobachtungen stehen. Um diesen Widerspruch aufzulösen, werden erfahrungsbasierte Verletzbarkeitsfunktionen für typische Mauerwerksgebäude auf der Grundlage der durch das Erdbeben vom 3. September 1978 bei Albstadt (mit einer Lokalmagnitude ML von 5,7 und Epizentralintensität I0 = VII—VIII) verursachten Schäden entwickelt. Anhand des Bauwerksbestandes von 1978 erfolgt die Einordnung der beobachteten Schäden in Schadensgrade auf Basis der European Macroseismic Scale EMS‐98 [1]. Die für den Bauwerksbestand repräsentativen Bauweisen werden herausgearbeitet; für die vorherrschenden Gebäude aus unbewehrtem Mauerwerk ist eine weitere Unterscheidung nach Baualter, Geschosszahl und phänomenologischen Gesichtspunkten möglich.

Vulnerability of masonry structures under seismic action: Damage analysis of the September 3, 1978 Albstadt earthquake. Numerical studies of the earthquake behavior of masonry buildings in Central Europe based on national building codes acc. to the Eurocode 8 lead to pessimistic damage prognoses, which are in contradiction to the observed behavior. In order to eliminate this discrepancy realistic experience‐based vulnerability and displacement functions for typical masonry constructions are developed. Because of the rather limited number of earthquake damage observations, the Magnitude ML 5.7 Albstadt earthquake from September 3, 1978 (intensity VII—VIII) in South Germany also based on its excellent documentation is reconstructed with the building stock existing at that time. The prevailing building types and for these the characteristic damage cases are investigated in close cooperation with the local authorities. The presented unreinforced masonry structures are divided by year of construction, number of storeys and phenomenological aspects.
Sustainable Masonry Constructions: Initial structural tests of brick and hemp‐lime composite walls
Authors: Molesworth Ian , Walker Peter
Published: June 2010

The work presented in this paper is part of a larger project investigating methods of reducing environmental impact, and improving performance, of fired clay brick masonry walls. Brick masonry has been combined with natural, sustainable materials in order to create a construction system that is structurally and thermally efficient. This is being accomplished through a programme of desk based research and physical testing on both small and full scale samples. The sustainable materials chosen for use in the project are unfired clay bricks and hemp‐lime.

The paper presents initial results from an on‐going experimental programme investigating performance of novel hemp‐lime and brickwork composite walls. Hemp‐lime provides sufficient thermal resistance to act as the insulative material in a wall construction. Due to its low structural strength and stiffness it has not been used in structural applications to date. Results from preliminary testing suggest that combining structural brickwork with a hemp lime inner leaf can result in some structural benefits despite its low strength. This hypothesis has been investigated further at a larger scale. Results of these initial tests are presented.

Nachhaltige Mauerwerkskonstruktionen: Erste Versuche an Verbundwänden aus Ziegeln und Hanf‐Kalk. Die in diesem Beitrag vorgestellte Arbeit ist Teil eines größeren Projektes zu Untersuchungen zur Verminderung von Umweltauswirkungen, sowie zur Verbesserung des Verhaltens von Wänden aus Ziegelsteinen. Ziegelmauerwerk wurde mit natürlichen, nachhaltigen Materialien kombiniert, um ein Bausystem zu schaffen, welches von der Tragwirkung und der Energieeffizienz her leistungsfähig ist. Durch Simulationen und Versuche sowohl an verkleinerten als auch an 1 : 1‐Modellen wurde dies erreicht. Die nachhaltigen Materialien, die für das Projekt ausgewählt wurden, sind ungebrannte Lehmziegel mit Hanf‐Kalk.

Der vorliegende Beitrag präsentiert erste Ergebnisse aus einer laufenden Untersuchung zum Verhalten von neuartigen Mauerwerkswänden, die aus Hanf‐Kalk und Ziegelmauerwerk kombiniert werden. Hanf‐Kalk bietet eine ausreichende thermische Beständigkeit, um als Dämmmaterial in einer Wandkonstruktion zu fungieren. Aufgrund seiner geringen Festigkeit und Steifigkeit kam es bisher nicht zu einer Anwendung bei baulichen Konstruktionen. Die Ergebnisse aus Vorversuchen lassen vermuten, dass die Kombination des tragenden Ziegelmauerwerks mit Hanf‐Kalk als innerer Schale trotz ihrer geringen Festigkeit zu einigen Vorteilen führen kann. Diese Hypothese wurde in größerem Maße weiter untersucht. Die Ergebnisse dieser ersten Tests werden vorgestellt.
Bcl11b represses a mature T‐cell gene expression program in immature CD4+CD8+ thymocytes
Authors: Kastner Philippe , Chan Susan , Vogel Walter K. , Zhang Ling‐Juan , Topark‐Ngarm Acharawan , Golonzhka Olga , Jost Bernard , Le Gras Stéphanie , Gross Michael K. , Leid Mark
Published: June 2010

Bcl11b is a transcription factor that, within the hematopoietic system, is expressed specifically in T cells. Although Bcl11b is required for T‐cell differentiation in newborn Bcl11b‐null mice, and for positive selection in the adult thymus of mice bearing a T‐cell‐targeted deletion, the gene network regulated by Bcl11b in T cells is unclear. We report herein that Bcl11b is a bifunctional transcriptional regulator, which is required for the correct expression of approximately 1000 genes in CD4+CD8+CD3lo double‐positive (DP) thymocytes. Bcl11b‐deficient DP cells displayed a gene expression program associated with mature CD4+CD8− and CD4−CD8+ single‐positive (SP) thymocytes, including upregulation of key transcriptional regulators, such as Zbtb7b and Runx3. Bcl11b interacted with regulatory regions of many dysregulated genes, suggesting a direct role in the transcriptional regulation of these genes. However, inappropriate expression of lineage‐associated genes did not result in enhanced differentiation, as deletion of Bcl11b in DP cells prevented development of SP thymocytes, and that of canonical NKT cells. These data establish Bcl11b as a crucial transcriptional regulator in thymocytes, in which Bcl11b functions to prevent the premature expression of genes fundamental to the SP and NKT cell differentiation programs.
Understanding the molecular mechanisms of the multifaceted IL‐10‐mediated anti‐inflammatory response: Lessons from neutrophils
Authors: Bazzoni Flavia , Tamassia Nicola , Rossato Marzia , Cassatella Marco A.
Published: June 2010

Analysis of the molecular mechanisms governing the ability of IL‐10 to keep inflammation under control has highlighted the existence of a great degree of plasticity and specificity with regard to innate immune cells. In this respect, neutrophils represent a perfect example of innate immune cells conditioned by external signals (for instance, by LPS), as well as by intracellular regulatory pathways, that render them optimally responsive to IL‐10 only when required. The focus of this review are the recent experimental findings that have uncovered the sophisticated and complex molecular mechanisms responsible for the modulation of pro‐ and anti‐inflammatory cytokine production by IL‐10 in neutrophils and other innate immune cells. Understanding how IL‐10 exerts its anti‐inflammatory response, particularly in the case of neutrophils, will provide novel clues leading, hopefully, to the therapeutic control of neutrophil‐driven inflammatory reactions, such as septic infections, rheumatoid arthritis, osteoarthritis and chronic obstructive pulmonary disease.
In2O3 Nanofibers and Nanoribbons: Preparation by Electrospinning and Their Formaldehyde Gas‐Sensing Properties
Authors: Li Zhipeng , Fan Yingju , Zhan Jinhua
Published: June 2010

In2O3 nanofibers and nanoribbons were prepared by electrospinning combined with a poly(vinyl pyrrolidone)‐assisted sol–gel technique. By tuning the experimental parameters, the morphological transformation of In2O3 from nanofibers to nanoribbons was achieved. It was found that both the rapid evaporation of solvent and the concentration of the precursor played important roles in the formation process of In2O3 nanoribbons. The average diameter of the In2O3 nanofibers is 180 nm. The nanoribbons have an average width of 1 μm and a thickness of about 150 nm. The lengths of both can reach millimeters. The average grain size consisting of nanofibers and nanoribbons is 18.6 and 11.2 nm, respectively. The gas‐sensing properties of In2O3 nanofibers and nanoribbons toward formaldehyde vapor were investigated. Interestingly, the gas sensor fabricated with In2O3 nanoribbons exhibited a higher and faster response at a relatively lower operating temperature than that fabricated with nanofibers.
A Microporous Metal–Organic Framework with Immobilized –OH Functional Groups within the Pore Surfaces for Selective Gas Sorption
Authors: Chen Zhenxia , Xiang Shengchang , Arman Hadi D. , Li Peng , Tidrow Steven , Zhao Dongyuan , Chen Banglin
Published: June 2010

A new two‐dimensional microporous metal–organic framework Cu(BDC‐OH)(H2O)·0.5DEF [abbreviation: Cu(BDC‐OH); H2BDC‐OH = 2‐hydroxybenzene‐1,4‐dicarboxylic acid; DEF = diethylformamide] with functional OH groups on the pore surfaces was solvothermally synthesized and structurally characterized. The activated Cu(BDC‐OH) exhibits a moderate Langmuir surface of 584 m2 g–1, a pore volume of 0.214 cm3 g–1, and C2H2/CH4 and CO2/CH4 selectivity of 6.7 and 9.3, respectively, at 296 K, thereby highlighting the promise for its application in gas separation.
Residential Solid Oxide Fuel Cell Generator Fuelled by Ethanol: Cell, Stack and System Modelling with a Preliminary Experiment
Authors: Lanzini A. , Santarelli M. , Orsello G.
Published: June 2010

The flexibility and feasibility of a 5 kW SOFC generator designed for natural gas (NG) and fuelled by a non‐conventional liquid fuel such as ethanol is analysed. A complete generator model is implemented to predict and determine the main criticalities when ethanol fuel is adoperated. The main balance‐of‐plant (BoP) units considered are the reformer, the recirculation system based on an ejector, the tubular cells bundles constituting the stack unit, the after‐burner zone and the air blower. The electrical and global efficiencies achieved at nominal operating conditions show how ethanol maintains generator performance good, while only slightly reducing the system AC efficiency from 48% (achieved by NG) to 45%. The effectiveness and flexibility of the recirculation system when changing the fuel is also verified since a safe steam‐to‐carbon ratio (STCR) is established after the fuel is switched from NG ethanol. The stack thermal management is analysed in detail and related to the system performances, showing how a high endothermic fuel reforming reaction is required to maintain the overall system efficiency. A preliminary experiment with ethanol feeding the Siemens generator is finally presented. The system response to the new fuel is monitored by several measured parameters and the system regulation is explained.
Hydrogeological and mineralogical analysis of the pre‐Romanesque monument of Santa María del Naranco, Asturias, Spain
Authors: Fernández Beatriz González , Pascual Celia Marcos , Casares Eduardo Menéndez
Published: June 2010

The church of Santa María del Naranco is an important monument from the pre‐Romanesque period of Asturian art. Here we present research that locates the probable source of travertine used in the construction of a vault within this monument. Since the genesis of this travertine is associated with spring activity, and archival evidence suggests that stone procurement during this period tended to be local, we surveyed existing carbonated aquifers within a 5‐km radius of the monument. We identified a spring (Sopeña) with an associated outcrop of discontinuous travertine that appeared to have been quarried in the past. We conducted X‐ray powder diffraction, electron microprobe, and inductively coupled plasma mass spectrometry analyses of samples extracted from the suspected travertine source, an additional more distant travertine quarry for comparison, and the vault. Matching mineralogy and geochemistry indicate that the Sopeña travertine was the probable source of rock material used in the construction of the vault. This study provides insight into local ancient monument construction and can assist in procuring original stone material for historical restoration. © 2010 Wiley Periodicals, Inc.
Alluvial geoarchaeology of an ephemeral stream: Implications for Holocene landscape change in the central part of the Ebro Depression, northeast Spain
Authors: Constante Ana , Luis Peña‐Monné José , Muñoz Arsenio
Published: June 2010

La Virgen is an ephemeral tributary of the Ebro River in northeast Spain with a complex alluvial sequence. We analyzed alluvial stratigraphy to develop a model of Holocene fluvial evolution for La Virgen and infer causes of floodplain dynamics. Three alluvial terraces were mapped and described using a combination of geoarchaeological and geomorphological techniques. Stratigraphic ages were estimated using 14C dating and archaeological remains. Sedimentation in the valley floor commenced in the Neolithic period ca. 6000 BC and continued during the Bronze and Iron ages (ca. 1800–500 BC), the Iberian and Roman periods (ca. 500 BC–AD 500), and the Middle Ages (ca. AD 500–1500). The main terrace (N3) is 14m thick and predominantly composed of sand, silt, and clay that we believe are derived from local hillslopes and represent a long period of human‐induced soil erosion that intensified during the Bronze and Iron ages until the Late Roman period. © 2010 Wiley Periodicals, Inc.
Using ichnofossils to characterize chert tools: A preliminary study from Southern Iberia
Authors: Rodríguez‐Tovar Francisco J. , Morgado Antonio , Lozano José A.
Published: June 2010

Characterizing raw material of stone tools used by Late Neolithic and Copper Age communities is important for interpreting access to available sources and establishing regional routes of distribution. Ichnological analysis may be used to help characterize lithic material and determine the source of artifacts. Here we report for the first time the existence of trace fossils in artifacts from the Late Neolithic and Copper Age of southern Spain. Ichnological analysis indicates a trace fossil assemblage consisting of relatively scarce small‐sized Chondrites and abundant Phycosiphon. A regional survey of natural outcrops and chert quarries indicates the presence of discrete trace fossils only in the samples from geological formations that are part of the Campo de Gibraltar Complex. Ichnological composition in these samples is similar to that discerned in the artifacts and suggests that this was the probable source of the chert used in tool manufacture. © 2010 Wiley Periodicals, Inc.
A Novel Role for Thyroid-Stimulating Hormone: Up-Regulation of Hepatic 3-Hydroxy-3-Methyl-Glutaryl-Coenzyme A Reductase Expression Through the Cyclic Adenosine Monophosphate/Protein Kinase A/Cyclic Adenosine Monophosphate–Responsive Element Binding Protein Pathway
Authors: Tian Limin , Song Yongfeng , Xing Mingzhao , Zhang Wei , Ning Guang , Li Xiaoying , Yu Chunxiao , Qin Chengkong , Liu Jun , Tian Xingsong , Sun Xianglan , Fu Rui , Zhang Lin , Zhang Xiujuan , Lu Yan , Zou Jianwen , Wang Laicheng , Guan Qingbo , Gao Ling , Zhao Jiajun
Published: June 2010

Elevated thyroid-stimulating hormone (TSH) and hypercholesterolemia commonly coexist, as typically seen in hypothyroidism, but there is no known mechanism directly linking the two. Here, we demonstrated that in liver cells, TSH promoted the expression of 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (HMGCR), a rate-limiting enzyme in cholesterol synthesis, by acting on the TSH receptor in hepatocyte membranes and stimulating the cyclic adenosine monophosphate / protein kinase A / cyclic adenosine monophosphate–responsive element binding protein (cAMP/PKA/CREB) signaling system. In thyroidectomized rats, the production of endogenous thyroid hormone was eliminated and endogenous TSH was suppressed through pituitary suppression with constant administration of exogenous thyroid hormone, and hepatic HMGCR expression was increased by administration of exogenous TSH. These results suggested that TSH could up-regulate hepatic HMGCR expression, which indicated a potential mechanism for hypercholesterolemia involving direct action of TSH on the liver. (Hepatology 2010)
Expanding Access to Hepatitis C Virus Treatment—Extension for Community Healthcare Outcomes (ECHO) Project: Disruptive Innovation in Specialty Care†
Authors: Arora Sanjeev , Kalishman Summers , Thornton Karla , Dion Denise , Murata Glen , Deming Paulina , Parish Brooke , Brown John , Komaromy Miriam , Colleran Kathleen , Bankhurst Arthur , Katzman Joanna , Harkins Michelle , Curet Luis , Cosgrove Ellen , Pak Wesley
Published: June 2010

The Extension for Community Healthcare Outcomes (ECHO) Model was developed by the University of New Mexico Health Sciences Center as a platform to deliver complex specialty medical care to underserved populations through an innovative educational model of team-based interdisciplinary development. Using state-of-the-art telehealth technology, best practice protocols, and case-based learning, ECHO trains and supports primary care providers to develop knowledge and self-efficacy on a variety of diseases. As a result, they can deliver best practice care for complex health conditions in communities where specialty care is unavailable. ECHO was first developed for the management of hepatitis C virus (HCV), optimal management of which requires consultation with multidisciplinary experts in medical specialties, mental health, and substance abuse. Few practitioners, particularly in rural and underserved areas, have the knowledge to manage its emerging treatment options, side effects, drug toxicities, and treatment-induced depression. In addition, data were obtained from observation of ECHO weekly clinics and database of ECHO clinic participation and patient presentations by clinical provider. Evaluation of the ECHO program incorporates an annual survey integrated into the ECHO annual meeting and routine surveys of community providers about workplace learning, personal and professional experiences, systems and environmental factors associated with professional practice, self-efficacy, facilitators, and barriers to ECHO. The initial survey data show a significant improvement in provider knowledge, self-efficacy, and professional satisfaction through participation in ECHO HCV clinics. Clinicians reported a moderate to major benefit from participation. We conclude that ECHO expands access to best practice care for underserved populations, builds communities of practice to enhance professional development and satisfaction of primary care clinicians, and expands sustainable capacity for care by building local centers of excellence.
A Longitudinal Study on the Natural History of Serum Hepatitis B Surface Antigen Changes in Chronic Hepatitis B
Authors: Chan Henry Lik-Yuen , Wong Vincent Wai-Sun , Wong Grace Lai-Hung , Tse Chi-Hang , Chan Hoi-Yun , Sung Joseph Jao-Yao
Published: June 2010

Serum hepatitis B surface antigen (HBsAg) quantification has been suggested to reflect the concentration of covalently closed circular DNA in the liver. We aimed to investigate the HBsAg levels at different stages of chronic hepatitis B and the changes in HBsAg level during the natural progression of disease. One hundred seventeen untreated patients with chronic hepatitis B were studied with longitudinal follow-up for 99 ± 16 months. HBsAg quantification was performed at the first visit, the last visit, and three visits at each quartile during the follow-up. At the first visit, HBsAg level was higher among patients who were hepatitis B e antigen (HBeAg)-positive (N = 49) than those who were HBeAg-negative (N = 68) (4.01 ± 0.91 log IU/mL versus 2.73 ± 1.25 log IU/mL,

P

< 0.001). HBsAg level was persistently high at approximately 5 log IU/mL among patients in the immune tolerance phase (N = 7). The HBsAg levels among patients with HBeAg-positive active disease (N = 25) or sustained HBeAg seroconversion (N = 17) were comparable at approximately 3-4 log IU/mL. The HBsAg levels among patients who were HBeAg-negative tended to be higher among patients with active (N = 46) than those with inactive disease (N = 22). The median HBsAg levels decreased in HBeAg-negative patients with active and inactive disease by 0.041 log IU/mL/year and 0.043 log IU/mL/year, respectively. Twenty-two (17%) patients had HBsAg reduction >1 log IU/mL at the last visit; most of them showed reduced hepatitis B virus DNA, and eight had HBsAg loss.

Conclusion:

HBsAg remained stable in HBeAg-positive patients and tended to reduce slowly in HBeAg-negative patients. Reduction of HBsAg for >1 log IU/mL could reflect improved immune control. (Hepatology 2010)
Professional knowledge creation in the hospital sector: a qualitative study in Taiwan
Authors: Yang Chen‐Wei , Fang Shih‐Chieh , Lin Julia L.
Published: June 2010

This paper aims to develop a professional knowledge creation model for the hospital sector. For this purpose, we qualitatively explore the determinants and process of knowledge creation in the hospital sector. Drawing from organization theory, we develop a hospital's professional knowledge creation model and develop three propositions first. We further explore the theoretical model at organization level by case study in Taiwan. The findings suggest that the hospital's professional knowledge creation is influenced by knowledge stock, social ties and isomorphic pressures as propositions argued. However, hospitals' attempts to keep aligned with their highly institutionalized environments may pay more attention to both existing knowledge stock and the process of professional knowledge creation for their survival. Finally, it is hoped that the significances of this study will contribute to the development of hypotheses in the future quantitative study for building a generalized knowledge creation model for the hospital organization. Copyright © 2010 John Wiley & Sons, Ltd.
Impact of the spatial distribution of imperviousness on the hydrologic response of an urbanizing basin
Authors: Mejía Alfonso I. , Moglen Glenn E.
Published: June 2010

An event‐based model is used to investigate the impact of the spatial distribution of imperviousness on the hydrologic response of a basin characterized by an urban land use. The impact of the spatial distribution of imperviousness is investigated by accounting for its location within the basin when estimating the generated runoff and the hydrologic response. The event model accounts for infiltration and saturation excess; the excess runoff is routed to the outlet using a geomorphologic unit hydrograph. To represent the spatial distribution of rainfall and imperviousness, radar and remotely derived data are used, respectively. To estimate model parameters and analyse their behaviour, a split sample test and parameter sensitivity analysis are performed. From the analysis of parameters, we found the impervious cover tends to increase the sensitivity and storm dependency of channel routing parameters. The calibrated event model is used to investigate the impact of the imperviousness gradient by estimating and comparing hydrographs at internal locations in the basin. From this comparison, we found the urban land use and the spatial variability of rainfall can produce bigger increases in the peak flows of less impervious areas than the most urbanized ones in the basin. To examine the impacts of the imperviousness pattern, scenarios typifying extreme cases of sprawl type and clustered development are used while accounting for the uncertainty in parameters and the initial condition. These scenarios show that the imperviousness pattern can produce significant changes in the response at the main outlet and at locations internal to the overall watershed. Overall, the results indicate the imperviousness pattern can be an influential factor in shaping the hydrologic response of an urbanizing basin. Copyright © 2010 John Wiley & Sons, Ltd.
Induction of Foxp3 expression in T cells by cellulose acetate beads in vitro
Authors: Jimma Fumie , Takeda Yuji , Kaneda Kenta , Wakabayashi Ichiro
Published: June 2010

Gene expression of transforming growth factor‐β (TGF‐β) is needed to induce expression of transcription factor forkhead box P3 (Foxp3), which is required for the development and function of regulatory T (Treg) cells. The number of circulating Treg cells and the level of Foxp3 expression increase during granulocyte and monocyte apheresis (GMA), a useful therapy for ulcerative colitis. However, the mechanism underlying GMA‐induced Foxp3 expression is unknown. We found that the level of TGF‐β mRNA in peripheral blood mononuclear cells (PBMCs) was augmented just after treatment of peripheral blood with a GMA carrier, cellulose acetate beads, in vitro and that Foxp3 expression in PBMCs increased after culturing these cells for 5 days after the treatment. The augmentation of TGF‐β expression was observed in CD3−PBMCs but not in CD3+T cells. Furthermore, the increase in Foxp3 expression in T cells depended on co‐culture with CD3−PBMCs. We conclude that cellulose acetate beads have an ability to induce Foxp3 expression in peripheral blood T cells via augmentation of TGF‐β expression in CD3−PBMCs. J. Clin. Apheresis 25:216–222, 2010. © 2010 Wiley‐Liss, Inc.
Expression of caspase‐8 and caspase‐9 in rat hippocampus during postnatal development
Authors: Chang Li‐Rong , Liu Jin‐Ping , Song Yi‐Zhi , Lu Tao , Lu Gang , Wu Yan
Published: June 2010

The role of caspases in the regulation of apoptosis of neurons during development is well established. An emerging body of evidence indicates that caspases may also play significant roles which are nonapoptotic. We have demonstrated previously that the executor caspase‐3 exhibited a unique pattern of spatiotemporal expression in the postnatal rat hippocampal subregions, and the activation of caspase‐3 in different hippocampal neurons appeared to have distinct roles during postnatal development. In the present study, we examined the expressions of initiator caspases in the hippocampus, using immunofluorescent staining for caspase‐8 and caspase‐9, and Hoechst 33342 staining for nuclear chromatin to assess caspase‐8 and ‐9 expression in the CA1, CA3, and the dentate gyrus (DG) on postnatal days (P) 0, P2, P4, P7, P14, P21, P28, P56. The results indicate that caspase‐8 and caspase‐9 were expressed in pyramidal neurons of CA1 and CA3 fields, and granular neurons of the DG during development. Caspase‐8 was expressed in a general upward trend while caspase‐9 showed a slight downward pattern, but still remained at high levels in the adult hippocampus. The expression profiles of caspases‐8 and ‐9 are distinct from that of the apoptotic cells. These data indicate that caspase‐8 may be involved not only in the classical apoptotic function, but also in the cell death of necrosis, and in response to different insults and other nonapoptotic functions. Caspase‐9 plays a role in apoptosis during postnatal development, but it may have other functions as well. Microsc. Res. Tech. 74:153–158, 2011. © 2010 Wiley‐Liss, Inc.
Force spectroscopy of an elastic peptide: Effect of D2O and temperature on persistence length
Authors: Haward Simon J. , Shewry Peter R. , Marsh Justin , Miles Mervyn J. , Mc Master Terence J.
Published: June 2010

This study explores the mechanical unfolding of elastic protein analogues as a function of temperature, in both H2O and D2O, using atomic force microscopy (AFM) force spectroscopy in a specially constructed AFM liquid cell. This represents the first time that the effect of D2O on protein flexibility has been investigated at the single molecule level by this technique. Model elastic peptides, R6, were encoded from synthetic genes expressed in Escherichia coli. The peptides possess short N‐ and C‐terminal domains with central repetitive domains containing 13 repeats of the motif PGQGQQ‐plus‐GYYPTSLQQ. These sequences mimic those in native high molecular weight subunit glutenin proteins which confer elasticity to bread dough. Fitting single molecule stretching events to the worm‐like chain model, allows determination of the molecular persistence length under various experimental conditions. The effect of increasing the temperature is to increase the persistence length of the peptide in both H2O and D2O, consistent with the expected “thermal softening” effect. However, the effect is significantly enhanced in D2O, in which the persistence length at 45°C is ∼25% greater than the value measured in H2O at the same temperature. Stronger intrapeptide H‐bonding due to isotopic substitution of hydrogen for deuterium is the most likely cause of the enhanced backbone rigidity. Microsc. Res. Tech. 74:170–176, 2011. © 2010 Wiley‐Liss, Inc.
Effects of ethanol, formaldehyde, and gentle heat fixation in confocal resonance Raman microscopy of purple nonsulfur bacteria
Authors: Kniggendorf Ann‐Kathrin , Gaul Tobias William , Meinhardt‐Wollweber Merve
Published: June 2010

Resonance Raman microscopy is well suited to examine living bacterial samples without further preparation. Therefore, comparatively little thought has been given to its compatibility with common fixation methods. However, fixation of cell samples is a very important tool in the microbiological sciences, allowing the preservation of samples in a specific condition for further examination, future measurements, transport, or later reference. We examined the effects of three common fixatives—ethanol, formaldehyde solution, and gentle heat—on the resonant Raman spectrum of three generic bacteria species, Rhodobacter sphaeroides DSM 158T, Rhodopseudomonas palustris DSM 123T, and Rhodospirillum rubrum DSM 467T, holding carotenoid‐ and heme‐chromophores in confocal Raman microscopy. In addition, we analyzed the effect of poly‐L‐lysine coating of microscope slides, widely used for mounting biological and medical samples, on subsequent confocal Raman measurements of native and fixed samples. The results indicate that ethanol is preferable to formaldehyde as fixative if applied for less than 24 h, whereas heat fixation has a strong, detrimental effect on the resonant Raman spectrum of bacteria. Formaldehyde fixation excels at fixation times above 24 h, but causes an overall reduction in signal intensity. Poly‐L‐lysine coating has no discernable effect on the Raman spectra of samples fixed with ethanol or heat, but it further decreases the signal intensity, especially at higher wavenumbers, in the spectra of samples fixed with formaldehyde. Microsc. Res. Tech. 74:177–183, 2011. © 2010 Wiley‐Liss, Inc.
Tandem mass spectrometry for the analysis of self‐sorted pseudorotaxanes: the effects of Coulomb interactions
Authors: Jiang Wei , Schalley Christoph A.
Published: June 2010

The increasing complexity of self‐assembled supramolecules generates the need for analytical techniques that can accurately elucidate their structures. Here, we explore the ability of tandem mass spectrometry to deliver structural information on a series of self‐sorted crown ether/ammonium pseudorotaxanes. Of these intertwined molecules, different charge states are accessible and the effects of Coulomb interactions on the fragmentation pattern can be examined. Three different cases can be distinguished: (1) one or more counterions are present in the complex and compete with the crown for binding to the ammonium ion. This destabilizes the supramolecular bond. (2) In multiply charged complexes, charge repulsion significantly alters the fragmentation behavior as compared with singly charged ions. (3) If guest and host are both charged, the supramolecular bond becomes very weak. The different charge states provide different pieces of information about the supramolecules under study. Although singly charged complexes provide data on the building block connectivity, the doubly charged analogs are more reliable with respect to complex stoichiometry. As there are several factors which may cause differences in the gas phase and solution behavior of supramolecules (the presence and absence of solvation, changes in the strength of non‐covalent interactions upon ionization), it is important to establish well understood correlations between the complexes' gas‐phase behavior and their solution structures. A more detailed understanding will help to characterize the structures of even more complex supramolecular architectures by mass spectrometry. Copyright © 2010 John Wiley & Sons, Ltd.
Chemical inducers and transcriptional markers of oligodendrocyte differentiation
Authors: Joubert Lara , Foucault Isabelle , Sagot Yves , Bernasconi Lilia , Duval François , Alliod Chantal , Frossard Marie‐José , Pescini Gobert Rosanna , Curchod Marie‐Laure , Salvat Catherine , Nichols Anthony , Pouly Sandrine , Rommel Christian , Roach Arthur , Hooft van Huijsduijnen Rob
Published: June 2010

Oligodendrocytes generate and maintain myelin, which is essential for axonal function and protection of the mammalian central nervous system. To advance our molecular understanding of differentiation by these cells, we screened libraries of pharmacologically active compounds and identified inducers of differentiation of Oli‐neu, a stable cell line of mouse oligodendrocyte precursors (OPCs). We identified four broad classes of inducers, namely, forskolin/cAMP (protein kinase A activators), steroids (glucocorticoids and retinoic acid), ErbB2 inhibitors, and nucleoside analogs, and confirmed the activity of these compounds on rat primary oligodendrocyte precursors and mixed cortical cultures. We also analyzed transcriptional responses in the chemically induced mouse and rat OPC differentiation processes and compared these with earlier studies. We confirm the view that ErbB2 is a natural signaling component that is required for OPC proliferation, whereas ErbB2 inhibition or genetic knockdown results in OPC differentiation. © 2010 Wiley‐Liss, Inc.
Chronic caloric restriction reduces tissue damage and improves spatial memory in a rat model of traumatic brain injury
Authors: Rich Nicholas J. , Van Landingham Jacob W. , Figueiroa Silvia , Seth Rohit , Corniola Rikki S. , Levenson Cathy W.
Published: June 2010

Although it has been known for some time that chronic caloric or dietary restriction reduces the risk of neurodegenerative disorders and injury following ischemia, the possible role of chronic restriction in improving outcomes after traumatic brain injury (TBI) has not been previously studied. Therefore, 2‐month‐old male Sprague‐Dawley rats were divided into two dietary groups, an ad libitum fed group (AL) and a caloric‐restriction group (CR) that was provided with 70% of the food intake of AL rats (n = 10/group). After 4 months, a weight‐drop device (300 g) was used to produce a 2‐mm bilateral medial frontal cortex contusion following craniotomy. Additional animals in each dietary group (n = 10) were used as sham‐operated controls. The CR diet resulted in body weights that were reduced by 30% compared with AL controls. Not only did CR decrease the size of the cortical lesion after injury, there were marked improvements in spatial memory as measured by Morris water maze that included an increase in the number of animals successfully finding the platform as well as significantly reduced time to finding the hidden platform. Western analysis, used to examine the expression of proteins that play a role in neuronal survival, revealed significant increases in brain‐derived neurotrophic factor (BDNF) in the cortical region around the site of injury and in the hippocampus in CR rats after injury. These findings suggest that molecular mechanisms involved in cell survival may play a role in reducing tissue damage and improving cognition after TBI and that these mechanisms can be regulated by dietary interventions. © 2010 Wiley‐Liss, Inc.
Amyloid‐β oligomers impair fear conditioned memory in a calcineurin‐dependent fashion in mice
Authors: Dineley Kelly T. , Kayed Rakez , Neugebauer Volker , Fu Yu , Zhang Wenru , Reese Lindsay C. , Taglialatela Giulio
Published: June 2010

Soluble oligomeric aggregates of the amyloid‐β (Aβ) peptide are believed to be the most neurotoxic Aβ species affecting the brain in Alzheimer disease (AD), a terminal neurodegenerative disorder involving severe cognitive decline underscored by initial synaptic dysfunction and later extensive neuronal death in the CNS. Recent evidence indicates that Aβ oligomers are recruited at the synapse, oppose expression of long‐term potentiation (LTP), perturb intracellular calcium balance, disrupt dendritic spines, and induce memory deficits. However, the molecular mechanisms behind these outcomes are only partially understood; achieving such insight is necessary for the comprehension of Aβ‐mediated neuronal dysfunction. We have investigated the role of the phosphatase calcineurin (CaN) in these pathological processes of AD. CaN is especially abundant in the CNS, where it is involved in synaptic activity, LTP, and memory function. Here, we describe how oligomeric Aβ treatment causes memory deficits and depresses LTP expression in a CaN‐dependent fashion. Mice given a single intracerebroventricular injection of Aβ oligomers exhibited increased CaN activity and decreased pCREB, a transcription factor involved in proper synaptic function, accompanied by decreased memory in a fear conditioning task. These effects were reversed by treatment with the CaN inhibitor FK506. We further found that expression of hippocampal LTP in acutely cultured rodent brain slices was opposed by Aβ oligomers and that this effect was also reversed by FK506. Collectively, these results indicate that CaN activation may play a central role in mediating synaptic and memory disruption induced by acute oligomeric Aβ treatment in mice. © 2010 Wiley‐Liss, Inc.
Effects of zona incerta lesions on striatal neurochemistry and behavioral asymmetry in 6‐hydroxydopamine‐lesioned rats
Authors: Walker Ruth H. , Davies Georgia , Koch Rick J. , Haack Andrew K. , Moore Cynthia , Meshul Charles K.
Published: June 2010

Analysis of optimal sites for neurosurgical interventions in patients with Parkinson's disease (PD) suggests that significant clinical benefits may be achieved by involvement of the zona incerta (ZI). Unilateral electrolytic ZI lesions were made in intact and ipsilaterally 6‐hydroxydopamine (6OHDA)‐lesioned rats. Extracellular levels of glutamate, dopamine, and its metabolites in the ipsilateral striatum of awake rats were measured by using microdialysis, and tests of behavioral asymmetry were performed. In intact rats, ZI lesions had no effect on striatal extracellular glutamate or absolute levels of dopamine or metabolites, but dopamine metabolism decreased. After ZI lesions, contralateral forepaw use decreased in the forepaw adjusting steps test, but there was no change in response to vibrissa stimulation or cylinder exploration. There was no development of rotational asymmetry with amphetamine. In 6OHDA‐lesioned rats, striatal extracellular glutamate levels were elevated compared with controls. ZI lesions reduced the increased levels of glutamate back to normal values. ZI lesions reduced dopamine and homovanillic acid levels and showed a trend toward a decrease in dopamine metabolism. 6OHDA‐lesioned rats demonstrated the expected asymmetry of motor behaviors. After ZI lesions, ipsilateral turns following amphetamine injection were reduced, and there was a trend toward improved symmetry of forepaw use as determined with the forepaw adjusting steps test. There was no change in forepaw use with vibrissa stimulation or cylinder exploration. These data indicate that lesions of the ZI can affect striatal neurochemistry and motor behavioral asymmetry and suggest potential mechanisms by which ZI lesions may improve symptoms in PD. © 2010 Wiley‐Liss, Inc.