bluuebunny/crossref_metadata_2025_split huggingface dataset:
Socio-Cognitive Constructs and Characteristics of Classroom Communities: An Exploration of Relationships
Authors: Gallini Joan K. , Zhang Yu-Li 
Published: May 2005

In our Cultures Connect project, students engaged in interactions with local and remote audiences in a telecommunication, constructivist-based learning environment with an emphasis on writing about real-world science. The sample consisted of fourth and fifth grade students from a predominantly Hispanic school. They were part of a larger learning community with six other school sites connected through telecommunications. Participants at our site worked in cooperative groups toward the development of a research writing project on real-world science topics. Interactions with their distant peers about their research and other topics consistently occurred over the project's course. Data collected for the current study targeted the status of relationships among socio-cognitive factors with selected group dynamic features of task structure preference and audience awareness. The task structure preference variable divided the students into two groups: (1a) preference to work in teams or (1b) preference to work independently. For another analysis, students were divided into two groups on the basis of expressing an (2a) audience awareness or (2b) lack of an audience awareness in their written communications. Sociocognitive factors included confidence in writing, metacognition, academic motivation, and self-efficacy measures. A group-comparison design was used to compare the mean scores on these constructs for each group factor. The group reporting an audience awareness demonstrated a higher orientation to engaging in group interactions and in using metacognitive strategies in writing. A lack of confidence in writing was more prevalent among the students expressing less awareness to different audiences in their writing. Students with a preference to work by themselves showed statistically significant higher ratings in self-efficacy and a marginal significance on the use of metacognitive skills. Those with a group work preference enjoyed interacting with and receiving input from their peers. Other questions assessed students' perceptions of the benefits accrued as a Cultures Connect participant. The study and discussion of results are situated in the constructivist principles of instruction and learning. In addition, the research addresses related concepts of communities of learners, with implications for designing student-directed environments.
Public Awareness about Depression: The Effectiveness of a Patient Guideline
Authors: Patel Vimla L. , Branch Timothy , Mottur-Pilson Christel , Pinard Gilbert 
Published: May 2005

Objective:To evaluate the effectiveness of a patient guideline for educating the public in the recognition and treatment of depression.Method:Lay subjects were interviewed regarding their knowledge and beliefs about depression through the use of a semi-structured questionnaire. They were asked to “think aloud” while evaluating two clinical scenarios about depression, both with and without the use of a patient guideline. All interviews were audio taped, transcribed, and analyzed for subjects' thought processes and accuracy of responses in the presence and absence of the guideline.Results:Subjects with no prior history of depression identified fewer symptoms of depression listed in the patient guideline than did subjects with a history of depression. In the absence of the guideline, only 50% and 38% of subjects provided accurate diagnosis of depression for the simple and complex problems respectively. In the presence of the guideline, 92% and 83% of subjects provided an accurate diagnosis of depression for the simple and complex problems respectively.Conclusions:Lay people have a limited knowledge of depression and its treatment, and are less able to recognize symptoms of depression without the help of patient guideline. The guideline primes lay people to better recognize these symptoms and their relationship to diagnosis. This level of understanding about depression by lay people will facilitate improved communication between physicians and their patients.
Inside Front Cover: Self‐Organization of Semiconducting Polysiloxane‐Phthalocyanine on a Graphite Surface (Adv. Mater. 10/2005)
Authors: Samorí P. , Engelkamp H. , de Witte P. A. J. , Rowan A. E. , Nolte R. J. M. , Rabe J. P. 
Published: May 2005

AbstractHelical phthalocyaninato–polysiloxanes (PSPcs) can self‐organize at surfaces into highly ordered, rod‐like structures with a molecular cross‐section, as is shown schematically on the inside cover and reported by Samori and co‐workers on p. 1265. The inset is a scanning force microscopy image depicting experimentally obtained molecular cylinders with lengths in the range of hundreds of nanometers. The micrometers‐long cylinders so formed have high apparent stiffness and are good candidates for nanoscale photophysics and electronics applications.
Der Weg zu Fludelon: ein Tumortherapeutikum mit außergewöhnlichen Eigenschaften
Authors: Rivkin Alexey , Chou Ting‐Chao , Danishefsky Samuel J. 
Published: May 2005

AbstractEin Prinzip der Biosynthese von niedermolekularen Naturstoffen ist die Optimierung ihrer Fähigkeit, an bestimmte Proteine oder andere Zielmoleküle zu binden. Die Rahmenbedingungen, innerhalb derer ein zu synthetisierender Wirkstoff funktionieren muss, mögen letztlich ganz anders aussehen – dennoch kann der Einsatz solcher Naturstoffe als Leitsubstanzen zu einem signifikanten Vorsprung bei der Suche nach neuen, klinisch relevanten Wirkstoffen führen. In diesem Kurzaufsatz beschreiben wir, wie die chemische Synthese zu wirksameren Epothilonderivaten führte und wie dies wiederum die Entwicklung neuer Synthesewege inspirierte. Dies demonstriert den Nutzen von zielgerichteten Totalsynthesen bei der Suche nach neuen Wirkstoffen.
Kreislaufführung von Prozesswässern und Wertstofffraktionen
Authors: Reinhardt E. , Nurminen P. 
Published: May 2005

AbstractSowohl die Klarfiltration von Prozesswässern zur direkten Wiederverwendung oder als Vorbehandlung für nachfolgende Aufbereitungsschritte als auch die Konzentrierung und/oder Entsalzung von Dispersionen, Suspensionen usw. sind Einsatzgebiete für die Cross‐Rotation‐Filtration.
Produktionsintegrierter Umweltschutz mit innovativer Membrantechnik
Authors: Brickwedde F. , Schwake M. 
Published: May 2005

AbstractMembranverfahren haben sich in den letzten Jahren zu einer Querschnittstechnologie entwickelt, die eine effiziente Gestaltung von Prozessen gestattet. Laufend werden neue erfolgreiche industrielle Anwendungen für diese Trenntechnik präsentiert.
Membranen für Brennstoffzellen
Authors: Ruffmann B. , Rohland B. 
Published: May 2005

AbstractIn der Brennstoffzelle wird die chemische Energie eines Brennstoffs direkt in elektrische Energie umwandelt. Sie besteht aus zwei durch einen Elektrolyten gasdicht getrennten Halbzellen. An der Anode wird der Brennstoff oxidiert, an der Kathode der Sauerstoff reduziert. Die fünf Typen von Brennstoffzellen unterscheiden sich neben der Betriebstemperatur hauptsächlich durch die unterschiedlichen elektrolytisch leitenden Membranen. Alle Membranen müssen dabei neben ihrer unipolaren Ionenleitfähigkteit die Fähigkeit besitzen, Brenngase und Luft gasdicht voneinander zu trennen. Vor‐ und Nachteile der verschiedenen Membran‐Typen werden vorgestellt sowie Entwicklungstrends diskutiert.
Prozesssimulation druckgetriebener Membranprozesse
Authors: Schipolowski T. , Wozny G. 
Published: May 2005

AbstractZur Intensivierung industrieller Prozesse werden Membranverfahren verschiedener Art und konventionelle Trennverfahren zunehmend in derselben Anlage integriert. Die gegenseitige Abhängigkeit der Komponenten erfordert jedoch die Berücksichtigung der Gesamtanlage bei allen Entscheidungen im Rahmen von Prozesssynthese, Detail Engineering und Anlagenbetrieb. Daher besteht ein Bedarf zur Integration von Membranmodellen in die Simulationsumgebungen für chemische Prozesse. Der Beitrag gibt einen Überblick über die Anforderungen an Simulationsmodelle, häufig gewählte Ansätze und aktuelle Entwicklungen. Die Auswahl geeigneter Modelle ist außerhalb der typischen Anwendungsbereiche ein individueller Vorgang auf der Basis experimenteller Untersuchungen. Die Kriterien der Modellentwicklung werden anhand eines Fallbeispiels für die Simulation eines Gasreinigungsprozesses erläutert.
Fouling in Membranbelebungsreaktoren: Erfahrungen beim Betrieb mit diskontinuierlichem Schlammabzug
Authors: Drews A. , Iversen V. , Vocks M. , Kraume M. , Lesjean B. 
Published: May 2005

AbstractErfahrungen aus dem Betrieb einer Membranbelebung mit diskontinuierlichem Schlammabzug werden vorgestellt. Das Ziel ist, den Einfluss der Betriebsbedingungen auf Fouling und den Abbau extrazellulärer polymerer Substanzen zu bestimmen sowie mit bekannten Zusammenhängen aus Anlagen mit kontinuierlichem Abzug zu vergleichen.
Filtration mit Keramikmembranen – Anwendungsbeispiele aus der chemischen und der Lebensmittelindustrie
Authors: Bolduan P. , Latz M. 
Published: May 2005

AbstractDas klassische Anwendungsgebiet der Keramikmembranen ist die Abwassertechnik, darüber hinaus werden sie mittlerweile in allen Bereichen eingesetzt, in denen Medien filtriert werden, z. B. bei Recyclingprozessen in der chemischen Industrie, zur Zellabtrennung in der Biotechnologie oder zur Fruchtsaftfiltration in der Lebensmittelindustrie.
Membranen als Katalysatorträger
Authors: Schomäcker R. , Schmidt A. , Frank B. , Haidar R. , Seidel‐Morgenstern A. 
Published: May 2005

AbstractDurch den Einsatz von Membranen und Membranreaktoren in der Katalyse bieten sich verschiedene Möglichkeiten, den Umsatz, die Selektivität und die Raum‐Zeit‐Ausbeute von katalytischen Prozessen zu steigern. Am Beispiel von porösen Polymermembranen, in die Palladium‐Nanopartikel eingebettet sind, wird das Konzept der Anwendung von katalytisch aktiven Membranen für Hydrierreaktionen vorgestellt.
A novel atomic force microscope operating in liquid for in situ investigation of electrochemical preparation of porous alumina
Authors: Zhang Haijun , Zhang Dongxian , He Yulin 
Published: May 2005

AbstractA novel atomic force microscope (AFM) operating in liquid is described in this article. The specially designed AFM probe involves a tip attached to a cantilever, a tip holder, and a circular Plexiglas window. When the probe dives into the fluid, a circular meniscus is established around the Plexiglas window, preventing the tip from being affected or destroyed by surface tension of the liquid. In this setup, the whole scanning probe and the sample can completely dive into fluid. Meanwhile, the probe tip scans over the sample surface when the instrument works. These advantages enable the instrument to scan comparatively large or heavy samples with a high speed. The highest scan rate is about 30 lines/s or 14 s for a 400 × 400‐pixel, 3 × 3 μm image. Using the new AFM, we carry out in‐situ investigation of the formation processes of porous alumina during electrochemical anodic oxidation. A lead ring and an aluminum foil serve as cathode and anode, respectively. They are entirely immersed in the bath electrolyte, which is oxalic acid solution. During anodic oxidation, the AFM images of the sample surface are successively acquired without elevating the sample out of the solution. Experiments reveal that electrochemical reactions take place soon after the power supply is switched on, and with the progression of anodization, nanostructures of porous alumina gradually occur on the aluminum substrate, finally yielding ordered arrays of nanopores. As a typical example of applications, the results of this work show that the new AFM is an ideal and powerful tool for in‐situ observation and study of materials or samples in aqueous solutions. Microsc. Res. Tech. 66:126–131, 2005. © 2005 Wiley‐Liss, Inc.
Microscopy analysis of bone marrow–derived osteoprogenitor cells cultured on hydrogel 3‐D scaffold
Authors: Srouji S. , Maurice S. , Livne E. 
Published: May 2005

AbstractBone marrow contains progenitor cells that are able to differentiate into several mesenchymal lineages, including bone. These cells may also provide a potential therapy for bone repair. The purpose of this study was to select the osteoprogenitor cell subpopulation from bone marrow–derived mesenchymal stem cells (MSCs) and to test the ability of a hydrogel scaffold to support growth and osteogenic differentiation. MSCs isolated from rat femur bone marrow were cultured in DMEM medium supplemented with antibiotics, FCS, and L‐glutamine. Osteogenic supplements (dexamethasone, sodium β‐glycerophosphate, and ascorbic acid) were added for one, two or three weeks. A selective subpopulation of osteoprogenitor cells was identified by immunohistochemistry, general morphology, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Committed osteogenic cells were transferred to a 3‐D hydrogel scaffold and cultured for an additional week. In standard culture, the osteoprogenitor cells formed cell clusters identified by Alizarin red S staining and by positive osteocalcin immunostaining. The number of osteoprogenitor cells, matrix synthesis, and mineralization increased gradually up to three weeks in culture. Mineral deposition in the matrix analyzed by EDS revealed the presence of calcium and phosphate ions at a Ca/P molar ratio of 1.73 in both the osteogenic cultures and the scaffold osteoprogenitor culture. Histological preparations revealed cell clusters within the hydrogel scaffold and SEM analysis revealed cell clusters attached to the scaffold surface. It is concluded that the hydrogel scaffold can support growth and differentiation of osteogenic cultures including mineralization and can potentially serve as a bone graft substitute containing committed osteoprogenitor cells. Microsc. Res. Tech. 66:132–138, 2005. © 2005 Wiley‐Liss, Inc.
Recent advances in atomic‐scale spin‐polarized scanning tunneling microscopy
Authors: Smith Arthur R. , Yang Rong , Yang Haiqiang , Dick Alexey , Neugebauer Joerg , Lambrecht Walter R.L. 
Published: May 2005

AbstractThe Mn3N2 (010) surface has been studied using spin‐polarized scanning tunneling microscopy at the atomic scale. The principle objective of this work is to elucidate the properties and potential of this technique to measure atomic‐scale magnetic structures. The experimental approach involves the use of a combined molecular beam epitaxy/scanning tunneling microscopy system that allows the study of atomically clean magnetic surfaces. Several key findings have been obtained. First, both magnetic and non‐magnetic atomic‐scale information has been obtained in a single spin‐polarized image. Magnetic modulation of the height profile having an antiferromagnetic super‐period of c = 12.14 Å (6 atomic rows) together with a non‐magnetic superstructure having a period of c/2 = 6.07 Å (3 atomic rows) was observed. Methods of separation of magnetic and non‐magnetic profiles are presented. Second, bias voltage‐dependent spin‐polarized images show a reversal of the magnetic modulation at a particular voltage. This reversal is clearly due to a change in the sign of the magnetic term in the tunnel current. Since this term depends on both the tip's as well as the sample's magnetic local density of states, the reversal can be caused by either the sample or the tip. Third, the shape of the line profile was found to vary with the bias voltage, which is related to the energy‐dependent spin contribution from the 2 chemically inequivalent Mn sites on the surface. Overall, the results shown here expand the application of the method of spin‐polarized scanning tunneling microscopy to measure atomic‐scale magnetic structures. Microsc. Res. Tech. 66:72–84, 2005. © 2005 Wiley‐Liss, Inc.
Mechanically engraved mica surface using the atomic force microscope tip facilitates return to a specific sample location
Authors: Liu Zhiguo , Li Zhuang , Zhou Hualan , Wei Gang , Song Yonghai , Wang Li 
Published: May 2005

AbstractBy controlling the interaction between the atomic force microscope tip and mica, patterns of different sizes and shape have been produced on the surface of mica. Using these operator‐constructed patterns as a reliable marker, the original scanned sample location can be re‐located and imaged again on the same mica surface by atomic force microscopy (AFM). This location technique can be used to find the same object again even if the sample was removed from the AFM instrument or the sample was imaged in a different mode. Microsc. Res. Tech. 66:156–162, 2005. © 2005 Wiley‐Liss, Inc.
Ornithine transcarbamylase deficiency in pregnancy
Authors: Cordero D. R. , Baker J. , Dorinzi D. , Toffle R. 
Published: May 2005

SummaryWomen heterozygous for mutations at the ornithine transcarbamylase (OTC) locus may be at risk for hyperammonaemia and its untoward effects including coma and death in the postpartum period. We present the case of a pregnant woman heterozygous for OTC deficiency (McKusick 311250) whose past medical history was significant for two prior pregnancies complicated by postpartum hyperammonaemic coma. In the index pregnancy, increased levels of serum ammonium were noted during labour. Postpartum hyperammonaemia was averted by administration of oral sodium benzoate. Our experience demonstrates that in women at risk, perilous hyperammonaemia can be prevented through appropriate medical management.
Acid sphingomyelinase deficiency. Phenotype variability with prevalence of intermediate phenotype in a series of twenty‐five Czech and Slovak patients. A multi‐approach study
Authors: Pavlů‐Pereira H. , Asfaw B. , Poupčtová H. , Ledvinová J. , Sikora J. , Vanier M. T. , Sandhoff K. , Zeman J. , Novotná Z. , Chudoba D. , Elleder M. 
Published: May 2005

SummaryA multi‐approach study in a series of 25 Czech and Slovak patients with acid sphingomyelinase deficiency revealed a broad phenotypic variability within Niemann–Pick disease types A and B. The clinical manifestation of only 9 patients fulfilled the historical classification: 5 with the rapidly progressive neurovisceral infantile type A and 4 with a slowly progressive visceral type B. Sixteen patients (64%) represented a hitherto scarcely documented ‘intermediate type’ (IT). Twelve patients showed a protracted neurovisceral course with overt or mild neurological symptoms, three a rapidly progressing fatal visceral affection with rudimentary neurological lesion. One patient died early from a severe visceral disease. The genotype in our patients was represented by 4 frameshift and 14 missense mutations. Six were novel (G166R, R228H, A241V, D251E, D278A, A595fsX601). The Q292K mutation (homoallelic, heteroallelic) was strongly associated with a protracted neurovisceral phenotype (10 of 12 cases). The sphingomyelin loading test in living fibroblasts resulted in total degradation from less than 2% in classical type A to 70–80% in classical type B. In the IT group it ranged from 5% to 49% in a 24 h chase. The liver storage showed three patterns: diffuse, zonal (centrolobular), and discrete submicroscopic. Our series showed a notable variability in both the neurological and visceral lesions as well as in their proportionality and synchrony, and demonstrates a continuum between the historical ‘A’ and ‘B’ phenotypes of ASM deficiency. This points to a broad phenotypic potential of ASM deficiency, suggesting the existence of still unknown factors independently controlling the storage level in the visceral and neuronal compartments. This report highlights the important position of the IT in the ASM deficiency phenotype classification. We define IT as a cluster of variants combining clinical features of both the classical types. The protracted neuronopathic variant with overt, borderline or subclinical neurology prevails and is important in view of future enzyme replacement therapy. It appears more common in central Europe. The visceral, rapidly progressing early fatal type has been recognized rarely so far.
Hyperchylomicronaemia due to lipoprotein lipase deficiency as a cause of false‐positive newborn screening for biotinidase deficiency
Authors: Santer R. , Gokçay G. , Demirkol M. , Gal A. , Lukacs Z. 
Published: May 2005

SummaryTwo cases of molecular genetically proven lipoprotein lipase deficiency are reported. Both patients were detected owing to a false‐positive neonatal screening test for biotinidase deficiency. We conclude that both the fluorimetric and the colorimetric screening tests for biotinidase deficiency used with dried blood samples are affected by severe hyperchylomicronaemia and that, most probably, severe plasma turbidity interferes with the assay.
Pyrolytic Graphites: Their Description as Semimetallic Molecular Solids
Authors: Klein Claude A. 
Published: May 2005

This paper is concerned with an investigation of the electrical,the galvanomagnetic, and the thermoelectric properties of pyrolytic graphites whose morphological features are conditioned by the deposition temperature, the heat treatment, and the doping level.
(1) Basal-plane magnetoresistance and c-direction specific resistance of deposits prepared at temperatures ranging from 1900°to 2500°C point to a remarkable improvement of the crystallites'alignment with rising deposition temperature. In both crystallographic directions the Seebeck coefficient closely follows semi-empirical predictions based on the two-dimensional model of theπ-electron bands. The Fermi level of a standard deposit (2100°C)is at 0.025 eV below the valence-band edge and thus indicates that crystal defects trap about 7.5×1018 electrons/cm3 at room temperature;this figure is in accord with a Hall coefficient of 0.33 cm3/C. The average in-plane mobility (930 cm2/V-sec) corresponds to a mean free path of the order of the crystallite diameter (250 Å).
(2) Post-deposition treatment at temperatures above 2500°C results in (a) a rapid drop of the room-temperature basal-plane resistivity down to 50 μΩ-cm or less, (b) a Hall effect conversion from p to n type in the early stages of graphitization, and (c) a trend toward negative Seebeck coefficients in the layer planes. In conjunction with low-field magnetoresistance measurements these results can be described in terms of semimetallic concepts, the simultaneous presence of holes and electrons with equal concentrations(6×1018 cm−3 at room temperature) stemming from a slight band overlap. Average mobilities imply that the carrier behavior approaches single-crystal characteristics ( ≈ 104 cm2/V-secat room temperature) after heat treatment above 3000°C. Normal to the layers, the specific resistance always exceeds 0.1 Ω-cm, which points to a molecular conduction process in this direction.
(3) An incorporation of boron into the carbon-hexagon networks lowers the electrical resistance of graphite particularly in the c direction (twenty-fold decrease at a composition of 0.6 at.%B); concurrently the two temperature coefficients become approximately equal to zero. In the rigid-lattice approximation band-population figures derived from the resistivity temperature dependence reflect the Hall coefficient behavior, the peak occurring at an equivalent boron content of 0.04%. The ionization efficiency is of the order of 50% with a Fermi level depressed by more than 0.1 eV. Thermoelectric power measurements in the c direction accord with the view that charge transport across the layer planes involves most of the excess holes, and reveal that boron enhances the Seebeck anisotropy of graphite.