bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing the individualized care model
Authors: Suhonen Riitta , Välimäki Maritta , Leino‐Kilpi Helena , Katajisto Jouko
Published: December 2004

Background.  Although there has been some research to identify the dimensions on which individualized care should be measured, the indicators that constitute individualized care remain unclear.

Objectives.  To describe briefly the maintenance of individualized care and to test a hypothetical model of individualized care in a sample of surgical patients.

Design and methods.  A correlational survey design was used. Data were collected with questionnaires from adult patients (n = 454) discharged from surgical wards in one Finnish hospital district (response rate 91%). Structural equation modelling LISREL SIMPLIS using maximum likelihood estimation was used to estimate and test the parameters of the hypothesized model derived deductively from the previous literature.

Results.  The goodness‐of‐fit statistics supported the basic solution of the Individualized Care Model, although two additional paths indicating error covariances between the sub‐concepts were identified in the revised model. In this model individualized care is defined in terms of patients’ views of nursing activities aimed at supporting individuality in care and in terms of perceptions of individuality in their own care.

Conclusions.  The model has been found to capture attributes that characterize individualized care. It can be used as a basis for evaluation in clinical nursing practice from patients’ point of view. The study highlights the importance of patients’ clinical situation, personal life situation and decisional control as predictors of individualized care. The results also confirm the construct validity of the previously developed Individualized Care Scale.
The meaning of caring as described by nurses caring for a person who acts provokingly: an interview study
Authors: Hellzen Ove , Asplund Kenneth , Sandman Per‐Olof , Norberg Astrid
Published: December 2004

Nurses working with people with learning disabilities are sometimes exposed to provoking behaviour such as unpredictable and violent actions, spitting and sexual harassment. Eight nurses at a group dwelling in Sweden were interviewed about their experiences when caring for a person who acts provokingly. Narrative interviews were conducted and interpreted using a method inspired by Ricoeur. Three themes were formulated which describe nurses’ feelings of being tormented, disrupted and helpless. Nurses describe themselves as being deeply humiliated by physical violence, spittle, sexual invective and actions on the part of the patient. They respond more to being spat on and the sexual invective than to the patient's physical violence. The frequent humiliations could be seen as a symbolic language connected to defilement and ‘evil’ and therefore as having a deep symbolic meaning for the nurses. These results were interpreted and reflected on in the light of a theoretical framework from an affliction perspective in order to achieve a deeper understanding of the text. This paper shows that an affliction perspective is important when searching for the meaning of caring for a patient who acts provokingly. The study indicates that the goal in a provoking care situation must be to see the provoking patient, as he appears to the nurses in order to glimpse the goodness concealed behind the provoking facade.
Nursing staff and nursing students‘ emotions towards homosexual patients and their wish to refrain from nursing, if the option existed
Authors: Röndahl Gerd , Innala Sune , Carlsson Marianne
Published: December 2004

Studies have reported that homosexual patients fear they will not receive adequate care if they openly show their sexual orientation, for example, when introducing their partner. The aims of this study were to investigate the emotions of nursing staff and nursing students, and possible relations to cultural background and gender, towards homosexual patients; whether nursing staff and nursing students would choose to refrain from nursing homosexual patients, if the option existed; and, if so, how they express their wish to refrain from nursing this group of patients. All participants received verbal and written information before the study started. Returning a completed questionnaire indicated a participant's tacit consent. Approval was obtained from the heads of departments and persons in charge of nursing and nursing assistant programmes. The study had a descriptive, comparative design, and an Affect Adjective Checklist (AAC) and specially designed Nursing Behaviour Questionnaire (NBQ) were used. The participants included nurses and assistant nurses from an infectious disease clinic, and students enrolled in a university nursing programme and upper secondary assistant nurses’ training, all in central Sweden. The findings showed that both professional nursing staff (response rate 67%, n = 57), and students (response rate 62%, n = 165), expressed emotions of homophobic anger, homophobic guilt and delight. Groups with a cultural background other than Swedish expressed more homophobia. No gender differences were indicated for homophobic emotions. In the professional group, 36% would refrain from nursing for homosexual patients if given the option. The corresponding figure for the students was 9%. The limitations were that the sample was small and not randomly selected, and as participation was anonymous no follow‐up could be done. It was concluded that the emotional factors of homosexual anger and homosexual guilt might be of value in helping to explain and predict attitudes towards homosexuals.
Satisfaction with care: a study of parents of children with congenital heart disease and parents of children with other diseases
Authors: Lawoko Stephen , Soares Joaquim J.F.
Published: December 2004

Aim: We compared parents of children with congenital heart disease (PCCHD, n = 1092) with parents of children with other diseases (PCOD, n = 112) regarding satisfaction with their children's care (SCC). We also examined the association between parental/patient characteristics and SCC.

Method: The parents completed a questionnaire about such areas as satisfaction with care, children's health status, and financial situation. The design was cross‐sectional and data were gathered over 20 consecutive days.

Results: The univariate and multivariate analyses showed that PCCHD were more satisfied with their children's medical care and waiting period for treatment of their ill children than PCOD, although the difference was only modest. Furthermore, mothers were less satisfied with staff attitudes than fathers, with the lowest satisfaction among mothers of children with CHD. However, the multivariate analysis indicated that less satisfaction with care was more associated with decreasing child age, unemployment, financial burden of disease, social isolation and psychological distress than with children's diseases, their severity and parental gender.

Conclusion: We corroborated some previous findings and may have provided new insights regarding determinants of SCC among parents. Interventions to improve SCC may need to address issues of parental psychological distress, socialization, and financial burden of illness. Possible ways of achieving this are discussed. Finally, research in a longitudinal format is needed to further scrutinize determinants of parental SCC.
Nursing documentation in nursing homes – state‐of‐the‐art and implications for quality improvement
Authors: Voutilainen Päivi , Isola Arja , Muurinen Seija
Published: December 2004

This study was designed to gain information on the quality of nursing care based on the comments in nursing records. The specific aims of the study were to find out if the patients‘ (i) individual needs are assessed, the goals for nursing care are set, and the nursing interventions are determined; (ii) if the patients’ needs are met and (iii) if goal achievement is regularly evaluated by including comments in nursing documents. In addition, the study aimed to describe the up‐to‐dateness of nursing care plans as well as the frequency of making daily notes. The data were collected on 36 wards of four residential homes. A 30% sample of the nursing documents on each ward was collected (n = 332) using the Senior Monitor instrument. The documents studied were mainly nursing care plans and daily note sheets. Seventy‐three per cent of the nursing home residents had an up‐to‐date nursing care plan at the time of data collection. The main results demonstrated that a written statement on the patient's mental ability was lacking in every fourth document although 75% of the patients suffer from at least moderate dementia in Finnish long‐term care institutions. Development activities should also be targeted to the documentation of clear and concrete means by which patients’ independent functioning is supported. In addition, evaluation was the area that warranted attention and development activities since only every fourth record included information on changes in the patients’ functional capability. Although a lot of in‐service training has been focused on improving the documentation practices, there is still a need for development. The means by which knowledge is transferred to guide the practice should be carefully considered. Also forms should be developed to meet the special requirements for recording nursing care in long‐term care settings.
Strain Measurement Techniques in Explosives
Authors: Lewis A. L. , Goldrein H. T.
Published: December 2004

Abstract:  Experiments to visualise the detailed microstructure of highly heterogeneous plastic‐bonded explosives have utilised high‐resolution moiré interferometry to measure localised deformations under quasi‐static loading. The information obtained has proved valuable in the development of finite element material models, and offers the potential to isolate and examine the influence of particular microstructural features (like binder layer thickness, or explosive crystal size) on deformation characteristics. New insight into failure processes and the implications of ageing effects have been obtained. The experimental methods and modelling have broad applicability to microstructural studies of a variety of composites.
Fresh meniscal allograft transplantation and autologous ACL/PCL reconstruction in a patient with complex knee trauma following knee dislocation – a case report
Authors: Lill H. , Hepp P. , Rose T. , Engel T. , Künzel E. , Josten C.
Published: December 2004

Instability of the knee joint, particularly in combination with the loss of one meniscus, regularly leads to the early development of arthritis. This paper describes the case of a 19‐year‐old male with ruptures of the anterior (ACL) and posterior cruciate ligament (PCL) along with the loss of the medial meniscus due to knee dislocation. Combined, time‐delayed reconstruction of both the ACL and PCL and the allogenic fresh meniscal transplantation of the medial meniscus without bone plugs were performed. The control arthroscopy performed 6 months post‐transplantation revealed good vitality and integration of the grafts as assessed both macroscopically and histologically. A small portion of the posterior horn had to be refixated, and the anterior horn was atrophic. At 24 months after trauma and 13 months following meniscal transplantation, the patient achieved a Lysholm score of 88 points and clinical examination indicated a stable knee. Fresh meniscal allograft transplantation, in combination with autologous ACL and PCL reconstruction, constitutes – in specialized centers – an alternative treatment option for complex trauma of the knee joint with loss of a meniscus.
A Novel Kinesin‐Like Protein, KIF1Bβ3 Is Involved in the Movement of Lysosomes to the Cell Periphery in Non‐Neuronal Cells
Authors: Matsushita Masafumi , Tanaka Shingo , Nakamura Norihiro , Inoue Hiroki , Kanazawa Hiroshi
Published: December 2004

The kinesin superfamily protein, KIF1Bβ, a splice variant of KIF1B, is involved in the transport of synaptic vesicles in neuronal cells, and is also expressed in various non‐neuronal tissues. To elucidate the functions of KIF1Bβ in non‐neuronal cells, we analyzed the intracellular localization of KIF1Bβ and characterized its isoform expression profile. In COS‐7 cells, KIF1B colocalized with lysosomal markers and expression of a mutant form of KIF1Bβ, lacking the motor domain, impaired the intracellular distribution of lysosomes. A novel isoform of the kinesin‐like protein, KIF1Bβ3, was identified in rat and simian kidney. It lacks the 5th exon of the KIF1Bβ‐specific tail region. Overexpression of KIF1Bβ3 induced the translocation of lysosomes to the cell periphery. However, overexpression of KIF1Bβ3‐Q98L, which harbors a pathogenic mutation associated with a familial neuropathy, Charcot‐Marie‐Tooth disease type 2 A, resulted in the abnormal perinuclear clustering of lysosomes. These results indicate that KIF1Bβ3 is involved in the translocation of lysosomes from perinuclear regions to the cell periphery.
How to Roll an Endothelial Cigar: The Biogenesis of Weibel‐Palade Bodies
Authors: Michaux Grégoire , Cutler Daniel F.
Published: December 2004

Weibel‐Palade bodies (WPB) are the regulated secretory organelles of endothelial cells. These cigar‐shaped membrane‐bound structures function in both hemostasis and inflammation but their biogenesis is poorly understood. Here, we review what is currently known about their formation. The content of WPBs is dominated by the hemostatic factor von Willebrand factor (VWF), whose complex biogenesis ends in the formation of high molecular weight multimers. VWF is also organized into proteinaceous tubules which underlie the striated interior of WPBs as seen in the EM. VWF expression is necessary for formation of WPBs, and its heterologous expression can even lead to the specific recruitment of WPB membrane proteins, including the leukocyte receptor P‐selectin, the tetraspanin CD63, and Rab27a. Unusually, the VWF propeptide is implicated in the biogenesis of WPBs, being essential for formation of the storage compartment. The elongation of the cigars and the formation of the tubules are determined by non‐covalent interactions between pro‐ and mature VWF proteins. Surprisingly, high molecular weight multimers seem neither necessary nor sufficient to trigger formation of a storage compartment, and do not seem to have any role in WPB biogenesis. Von Willebrand's disease, usually caused by mutations within VWF, has provided many of the insights into the way in which VWF drives the formation of these organelles.
Protein–Protein Interactions of ESCRT Complexes in the Yeast Saccharomyces cerevisiae
Authors: Bowers Katherine , Lottridge Jillian , Helliwell Stephen B. , Goldthwaite Lisa M. , Luzio J. Paul , Stevens Tom H.
Published: December 2004

Ten class E Vps proteins in yeast are known components of the ESCRT complexes I, II and III, which are required for the sorting of proteins to the lumenal membranes of multivesicular bodies. We used the yeast 2 hybrid system to analyze the protein–protein interactions of all 17 soluble class E Vps proteins, as well as proteins thought to be required for the ubiquitination and deubiquitination of cargo proteins at multivesicular bodies. We identified novel interactions between yeast ESCRT complex components suggesting that ESCRTI binds to both ESCRTII and ESCRTIII. These interactions were confirmed by GST pull‐down experiments. Our data indicate that the link between ESCRTI and ESCRTIII is via Vps28p and Vps37p/Srn2p binding directly to Vps20p, as well as through indirect interactions via ESCRTII. This is in contrast to the situation in mammalian cells where ESCRTI and ESCRTIII interact indirectly via ALIX, the mammalian homologue of yeast proteins Vps31p/Bro1p and Rim20p. Our data also enable us to link all soluble class E Vps proteins to the ESCRT complexes. We propose the formation of a large multimeric complex on the endosome membrane consisting of ESCRTI, ESCRTII, ESCRTIII and other associated proteins.
Annulate Lamellae Play Only a Minor Role in the Storage of Excess Nucleoporins in Drosophila Embryos
Authors: Onischenko Evgeny A. , Gubanova Natalia V. , Kieselbach Thomas , Kiseleva Elena V. , Hallberg Einar
Published: December 2004

The nuclear pore complexes (NPCs), multiprotein assemblies embedded in the nuclear envelope, conduct nucleo‐cytoplasmic traffic of macromolecules. Mimics of NPCs, called annulate lamellae pore complexes (ALPCs), are usually found in cytoplasmic membranous stacks in oocytes and early embryonic cells. They are believed to constitute storage compartments for excess premade nucleoporins. To evaluate the extent to which ALPCs store nucleoporins in early embryonic cells we took advantage of syncytial Drosophila embryos, containing both AL and rapidly proliferating nuclei in the common cytoplasm. Electron microscopic morphometric analysis showed that the number of ALPCs did not decrease to compensate for the growing number of NPCs during syncytial development. We performed Western blot analysis to quantify seven different nucleoporins and analyzed their intraembryonal distribution by confocal microscopy and subcellular fractionation. Syncytial embryos contained a large maternally contributed stockpile of nucleoporins. However, even during interphases, only a small fraction of the excess nucleoporins was assembled into ALPCs, whereas the major fraction was soluble and contained at least one phosphorylated nucleoporin. We conclude that in Drosophila embryos ALPCs play only a minor role in storing the excess maternally contributed nucleoporins. Factors that may prevent nucleoporins from assembly into ALPCs are discussed.
Determinants of Condom Use among Young People in Urban Cameroon
Authors: Meekers Dominique , Klein Megan
Published: December 2004

To reduce the prevalence of reproductive health problems among adolescents, governmental and nongovernmental organizations in Cameroon are implementing youth‐oriented reproductive health programs. To facilitate the design of effective programs to increase condom use, this study examines survey data on the determinants of having ever used condoms and on current condom use with regular and casual partners among unmarried young people in urban Cameroon. While most adolescents have tried condoms at least once, use remains inconsistent. Parental support, personal risk perception, and self‐efficacy are found to be associated with higher levels of condom use, Youth‐oriented programs seeking to increase the number of new condom users among the young should promote parental support for condom use and enhance young people's perceptions of personal risk. Programs that work to convince the young that their sexual history can put them at risk of HIV infection and that dispel the myth that HIV risk with regular partners is low may serve to increase personal risk perception. Finally, communications programs should aim to increase adolescents' self‐efficacy, particularly in terms of their perceived ability to convince partners to use condoms and to use them correctly.
NEW LEARNING AUTOMATA BASED ALGORITHMS FOR ADAPTATION OF BACKPROPAGATION ALGORITHM PARAMETERS
Authors: MEYBODI M. R. , BEIGY H.
Published: December 2004

One popular learning algorithm for feedforward neural networks is the backpropagation (BP) algorithm which includes parameters, learning rate (η), momentum factor (α) and steepness parameter (λ). The appropriate selections of these parameters have large effects on the convergence of the algorithm. Many techniques that adaptively adjust these parameters have been developed to increase speed of convergence. In this paper, we shall present several classes of learning automata based solutions to the problem of adaptation of BP algorithm parameters. By interconnection of learning automata to the feedforward neural networks, we use learning automata scheme for adjusting the parameters η, α, and λ based on the observation of random response of the neural networks. One of the important aspects of the proposed schemes is its ability to escape from local minima with high possibility during the training period. The feasibility of proposed methods is shown through simulations on several problems.
ON COMPUTING THE FUZZIFIER IN ↓FLVQ: A DATA DRIVEN APPROACH
Authors: ROMDHANE L. B. , AYEB B. , WANG S.
Published: December 2004

Clustering is an important research area that has practical applications in many fields. Fuzzy clustering has shown advantages over crisp and probabilistic clustering, especially when there are significant overlaps between clusters. Most analytic fuzzy clustering approaches are derived from Bezdek's fuzzy c-means algorithm. One major factor that influences the determination of appropriate clusters in these approaches is an exponent parameter, called the fuzzifier. To our knowledge, no theoretical reason leading to an optimal setting of this parameter is available. This paper presents the development of an heuristic scheme for determining the fuzzifier. This scheme creates close interactions between the fuzzifier and the data set to be clustered. Experimental results in clustering IRIS data and in code book design required for image compression reveal a good performance of our proposal.
INFLOW/OUTFLOW CONDITIONS FOR TIME-HARMONIC INTERNAL FLOWS
Authors: ATASSI OLIVER V. , ALI AMR A.
Published: December 2004

Inflow/Outflow conditions are formulated for time-harmonic waves in a duct governed by the Euler equations. These conditions are used to compute the propagation of acoustic and vortical disturbances and the scattering of vortical waves into acoustic waves by an annular cascade. The outflow condition is expressed in terms of the pressure, thus avoiding the velocity discontinuity across any vortex sheets. The numerical solutions are compared with the analytical solutions for acoustic and vortical wave propagation with and without the presence of vortex sheets. Grid resolution studies are also carried out to discern the truncation error of the numerical scheme from the error associated with numerical reflections at the boundary. It is observed that even with the use of exponentially accurate boundary conditions, the dispersive characteristics of the numerical scheme may result in small reflections from the boundary that slow convergence. Finally, the three-dimensional interaction of a wake with a flat plate cascade is computed and the aerodynamic and aeroacoustic results are compared with those of lifting surface methods.
Annexin A5 Scintigraphy of Forearm as a Novel In Vivo Model of Skeletal Muscle Preconditioning in Humans
Authors: Rongen Gerard A. , Oyen Wim J.G. , Ramakers Bart P. , Riksen Niels P. , Boerman Otto C. , Steinmetz Neil , Smits Paul
Published: December 2004

Background—

Nonlethal ischemia and reperfusion reduce ischemia-reperfusion-induced cell death, a phenomenon called ischemic preconditioning. In animal models, this potent endogenous protection is mimicked in vivo by administration of adenosine. In humans, exploitation of ischemic preconditioning is hindered by the lack of an appropriate in vivo model to study this phenomenon. To solve this problem, we aimed to set up an easy-to-use human in vivo model to study ischemic or pharmacological preconditioning.

Methods and Results—

Healthy male volunteers performed unilateral ischemic handgrip. At reperfusion, we intravenously injected technetium-99m-labeled Annexin A5, a presumed marker of ischemic injury, and we imaged both forearms and hands simultaneously with a gamma camera. Region of interest analysis (counts per pixel) and subsequent calculation of the percentage difference in radioactivity between experimental and control hands (thenar muscle; mean±SE) revealed significant uptake to the ischemically exercised tissue (26±3% at 4 hours after reperfusion;
P
<0.05). This selective localization of Annexin A5 was reduced by ischemic preconditioning (10 minutes of ischemia plus reperfusion before ischemic exercise) or by infusion of adenosine into the brachial artery to 6±1% and 10±3%, respectively (
P
<0.05 versus ischemic exercise alone), resembling observations in animal models with infarct size as an end point. Appropriate control experiments supported our conclusion.

Conclusions—

Annexin A5 scintigraphy can be applied to test pharmacological or physiological interventions for their ability to prevent ischemia-reperfusion injury.
A Novel Mouse Model of Hypogonadotrophic Hypogonadism: N-Ethyl-N-Nitrosourea-Induced Gonadotropin-Releasing Hormone Receptor Gene Mutation
Authors: Pask Andrew J. , Kanasaki Haruhiko , Kaiser Ursula B. , Conn P. Michael , Janovick Jo Ann , Stockton David W. , Hess David L. , Justice Monica J. , Behringer Richard R.
Published: December 2004

An autosomal-recessive mutation that causes hypogonadotrophic hypogonadism was isolated during an N-ethyl-N-nitrosourea mutagenesis screen in mice. Affected males had micropenis and small, undescended testes with spermatogenesis arrested at the pachytene stage of meiosis, leading to sterility. Androgen-sensitive organs were small and immature. Affected females were externally normal but sterile with small ovaries due to an arrest at the secondary stage of folliculogenesis, and the uterus and oviducts were thin and immature. Circulating reproductive hormones were significantly decreased in affected males and females. There was also a dramatic reduction in the numbers of FSH- and LH-producing gonadotrophs. Meiotic mapping of the mutation and candidate gene sequencing determined that the N-ethyl-N-nitrosourea-induced lesion is in the third transmembrane domain of the GnRH receptor gene (Gnrhr). In vitro studies indicate that the mutant receptor is not coupled to the plasma membrane signal transduction system. Moreover, this mutant cannot be rescued with defined GnRH receptor pharmacoperones (pharmacological chaperones), an approach that rescues many other misfolded mutants. The mutant GnRH receptor was also shown to exert a dominant-negative effect on wild-type receptor function, indicating that the mutant receptor is unable to fold properly and likely misrouted within the cell, not reaching the plasma membrane. Surprisingly, Gnrhr mutant transcripts were significantly up-regulated in the pituitaries of Gnrhr mutants, revealing a previously unknown autoregulatory feedback loop. This is the first report of a mouse with a Gnrhr loss of function mutation. These GnRH-insensitive mice provide a novel animal model for the study of human idiopathic hypogonadotrophic hypogonadism.
Polysilanes—a new look at some old materials
Authors: Miller Robert D.
Published: December 2004

In spite of the fact that the first polysilane derivatives were probably prepared in the mid 1920's, there was little scientific interest until recently. The synthesis of the first soluble homo and copolymers about 10 years ago has stimulated an explosive development of this class of materials. This brief review traces the historical development of the polysilanes and focuses on recent studies of polymer structure, electronic properties, photochemical reactions and mechanisms and finally on new applications.
15N CPMAS NMR study of the structure of polyaniline
Authors: Wehrle Bernd , Mortensen John , Limbach Hans‐Heinrich , Heinze Jürgen
Published: December 2004

The structure and properties of polyaniline are investigated using 15N cross polarization magic angle spinning (CPMAS) solid state NMR spectroscopy. The high resolution spectra obtained demonstrate the potential of the method for studying the structures of other nitrogen containing heterocyclic polymers.
Materials R&D at los alamos national laboratory
Authors: Follansbee Paul S.
Published: December 2004

The materials programs at Los Alamos National Laboratory (LANL) have broadend tremendously since the laboratory was originally founded to support the Mahattan Project, which led to the development of the atomic bomb. Alongside the primary national security mission of the laboratory, collaborations with industry that make use of the special expertise gathered at LANL are growing in importance. Some of the unique facilities available at LANL are described and several projects are highlighted, providing a good idea of the wide range of materials research being carried out at the laboratory today.
Shear‐induced orientation of side‐group liquid‐crystalline polymers
Authors: Kannan Rangaramanujam M. , Kornfield Julia A. , Schwenk Norbert , Boeffel Christine
Published: December 2004

Side group liquid‐crystalline polymers (SG‐LCP) will need to be macroscopically oriented if the applications foreseen for them are to be realized. The first observation of oscillatory‐sheer‐induced alignment of an SG‐LCP melt (the Figure shows a schematic of the rheo‐optical apparatus used) is reported. This discovery widens the potential applications of SG‐LCPs, but also raises fundamental questions regarding the mechanism of flow‐induced alignment.

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Electrochemistry of polydialkylcyclopentadithiophenes—modulation of π dimerization by interchain spacing groups
Authors: Zotti Gianni , Berlin Anna , Pagani Giorgio , Schiavon Gilberto , Zecchin Sandro
Published: December 2004

π dimerization in polythiophenes, leading to stabilization of the intermediate polaronic form, hasrecently been proposed as the origin of the distinctive twin process in the oxidation cycles of polythiophenes. Electrochemical measurements on polymers obtained by anodic cupling 4,4‐di‐n‐alkylcyclopentadithiophene (see Fugure) confirm this; the π dimerization operates when the spacing groups between the polymer strands are absent of the spacing group increases.

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“Atomic arrangements”: Join Japan to a UK university
Authors: Joyce Bruce A. , Vvedensky Dimitri D.
Published: December 2004

Collaboration with Japanese industry, universities, and government agencies is essential for any internationally recognized semiconductor research center. Since being established in 1989, the University of London Semiconductor Materials Interdisciplinary Research Centre has developed many such programs. Tha aims, organization, research, and results of one program “Atom Arrangement: Design and Control for New Materials” are described and the role of the “combination of cultures” highlighted.
Iron nitride/boron nitride magnetic nanocomposite powders
Authors: Gonsalves Kenneth E. , Chow Gan‐Moog , Zhang Yide , Budnick Joseph I. , Xiao Tongsan D.
Published: December 2004

A superparamagnetic nanocomposite consisting of magnetic particles in a non‐magnetic matrix phase, FexN/BN (x = 3 or 4), is one result of research targeted at reducing the grain size of crystalline materials from the conventional micrometer to the nanometer range. Superior mechanical, magnetic and physical properties are anticipated for small‐grain materials. The synthesis of FexN/BN via an inorganic gel is reported in which the precomposite gel is converted to the nanocomposite by thermochemical processing in a reactive gaseous environment.
Layer‐by‐layer growth and decomposition of an organic crystal observed in real time by atomic force microscopy
Authors: Schimmel Thomas , Winzer Bettina , Kemnitzer Rainer , Koch Thomas , Küppers Jürgen , Schwoerer Markus
Published: December 2004

Layer‐by‐layer growth of an insulating organic molecular crystal has been observed for the first time in situ and in real time using the atomic force microscope. It is shown that the growth and decomposition processes occurring at step edges are induced and controlled locally by the tip‐sample interaction. Detached molecules can be followed and their fate recorded. A mechanism is suggested for the simultaneous decomposition, molecular transport, and layer growth, and stability conditions are derived for nucleating islands.
Mesogenic calixarenes
Authors: Malthête Jacques
Published: December 2004

A novel class of mesogens consists of the calix[n]arenes (see Figure). In addition to forming interesting host‐guest complexes—which offer the possibility of investigations into mesomorphic stability connected with host‐guest complexation—these molecules may be used as the central core of cloumnar mesogens. Different ways of obtaining macroscopic ferroelectric stacking are also briefly considered.

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Electron–Electron Interactions in Organic Superconductors
Authors: Haddon Robert C. , Ramirez Arthur P. , Glarum Sivert H.
Published: December 2004

Superconductivity in organic superconductors is still not properly understood. The normal state magnetism of examples of quasi‐1D,2D, and 3D organic superconductors is summarized and compared. In addition to the results of d.c. magnetization, magnetic susceptibility, and ESR measurements, the densities of states derived from measurements and from badn‐structure calculations are discussed. The importance of electron‐electron interactions for all molecular superconductors is outlined.
Reaction of alkali metal intercalated C60 with oxygen: Deintercalation, activation, and decomposition
Authors: Snyder G. Jeffrey , Simon Arndt
Published: December 2004

The air sensitivity of C60 intercalated with an alkali metal has been known for some years. It is shown here that for K6C6, and Rb6C60 the route by which the deintercalation occurs involves–rather unexpectedly–the formation of the alkali metal carbonates, not the oxides. This observation is used to explain why impurity oxygen does not exist in alkali‐metal‐intercalated C60 although it is extremely difficult to remove oxygen from non‐intercalated C60.
Paramagnetic liquid crystalline nickel(II) compounds
Authors: Griesar Klaus , Galyametdinov Yuri , Athanassopoulou Maria , Ovchinnikov Igor , Haase Wolfgang
Published: December 2004

Metallomesogens containing paramagnetic transition metal ions are of interest because the orientation of these mesophases can be controlled by a magnetic field. The first paramagnetic Ni‐containing liquid crystals (related to the non‐mesogenic compound shown in the Figure) are reported. Their complicated temperature‐dependent magnetic behavior is discussed and shown to reflect changes in the coordination core of nickel.

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Homogeneous dispersion of nanostructured aluminum nitride in a polyimide matrix
Authors: Chen Xiaohe , Gonsalves Kenneth E. , Chow Gan‐Moog , Xiao Tongsan D.
Published: December 2004

Advanced polymer/nanoparticle composites are currently of great interest because of their unique properties. The bulk properties of these materials are strongly influenced by the nature of the ultrafine filler particles–including their dispersion. A technique is presented for the de‐agglomeration of chemically synthesized aluminum nitride nanoparticles and their uniforn dispersion in a polymer matrix. Detrailed mechanisms for the de‐agglomeration are discussed as topics for future investigation.
Synthesis of covalent carbon—nitride solids: Alternatives to diamond?
Authors: Lieber Charles M. , Zhang Z. John
Published: December 2004

Covalent carbon nitride has been produced for the first time. Binary carbon‐nitrogen solids are an important synthetic goal, since although β‐C3N4, has been predicted to have a hardness comparable to or greater than diamond, it cannot be produced by traditional solid‐state chemistry methods. The novel approach described here combines pulsed laser ablation with a high‐flux atomic beam. From comparisons with calculated diffraction patterns, it is inferred that crystalline β‐C3N4, has been synthesized, although in an impure form.
Photoinitiated Electron Transfer in Synthetic Model Systems
Authors: Akins Daniel L. , Guo Chu
Published: December 2004

Studies of electon transfer (ET) have enhanced our understanding of photosynthetic and photobiochemical systems in recent years, but much remains to be learnt. In particular, the connection between the arthitecture of the photosynthetic reaction center and its function needs to be investigated, Raman scattering studies are presented on model ET systems–covalently linked porphyrin‐methylviologen and porphyrin‐dibenzylviologen–in which the doner and acceptor are kept in a well‐defined geometry, and the conclusions that can be drawn are discussed.
Starburst/Cascade Dendrimers: Fundamental building blocks for a new nanoscopic chemistry set
Authors: Tomalia Donald A.
Published: December 2004

That dendrimer structures act as fundamental chemical building blocks (see Figure), forming a “nanoscopic chemistry set” analogous to the “picoscopic chemistry set” formed by atoms, is discussed in this review. Following the logic used by 19th century chemists while defining the atomic “chemistry set”, it is shown that the ability to preface directionality in dendrimer systems validates this approach.

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Highly polarizable biaryl salts for liquid crystals and nonlinear optics: Synthesis and properties of a phenol/pyridinium triflate
Authors: Boy Philippe , Combellas Catherine , Mathey Grágoire , Palacin Serge , Persoons André , Thiébault André , Verbiest Thierry
Published: December 2004

A nonlinear waveguide material with a good transparency/efficiency trade‐off is presented. The synthesis of the biaryl‐based salt and its mesomorphic and nonlinear optical properties, including second harmonic generation from floating Langmuir‐Blodgett layers, are described. The advantages of this new phenol/pyridinium triflate, which exhibits mesomorphic properties over a 50°C range, compared to the uncharged and zwitterionic analogues are discussed.
Chlorine precursor route (CPR) chemistry to poly(p‐phenylene vinylene)‐based light emitting diodes
Authors: Hsieh Bing R. , Antoniadis Homer , Bland Douglas C. , Feld William A.
Published: December 2004

Thin film organic electrolumiscent devices based on poly 2,3‐diphenyl‐1,4‐phenylenevinylene (DP‐PPV, see Fig.) have been fabricated using the chlorine‐precursor route. Devices with the configuration Mg/DP/‐PPV/ITO are shown to have an external quantum efficiency for green electroluminescence of 0.1%, a value comparable to the efficiency of CA/PPV devices.

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The radical cation iodide of the new electron donor tetraiodotetrathiafulvalene: Magnetic properties and crystal structure
Authors: Gompper Rudolf , Hock Joachim , Polborn Kurt , Dormann Elmar , Winter Hubert
Published: December 2004

Tetrathiafulvalene and its derivatives can be chemically or electrochemically oxidized to yield stable radical cation salts which display unusual electrical properties. In order to increase the dimensionality of the system by extending the π‐conjugation and thus stabilizing the metallic state, while at the same time keeping the system small, the tetraiodo‐derivative (see Fig.) has been synthesized and characterized.

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Imaging the surfaces of nanoporous semiconductors by atomic force microscopy
Authors: Enzel Patricia , Henderson Grant S. , Ozin Geoffrey A. , Bedard Robert L.
Published: December 2004

Open framework semiconductors tin(IV) sulfides and tin(IV) selenides) exhibiting bulk crystalline nanoporosity have been studied using atomic force microscopy (AFM). The bulk porosity is reflected in the surface structures of these materials (see Fig.), and little reconstruction can be detected, important points in the assessment of the electrical transport characteristics of this new class of nanoporous materials.

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New nonlinear optical crystals for UV and VUV harmonic generation
Authors: Xia Younan , Chen Chuangtian , Tang Dingyuan , Wu Baichang
Published: December 2004

Among the nonlinear optical (NLO) materials, second harmonic generators are important because of their applications in extending the limited frequencies available from lasers. A theory is presented that makes it possible to design and synthesize new NLO materials according to need, based on an understanding of the structure–property relationships. Four inorganic NLO crystals serve as an illustration of the success of this method.
III–V based diluted magnetic semi conductors: Carrier–induced magnetism
Authors: Munekata Hiro
Published: December 2004

Magnetism in III–V semiconductors is a comparatively new area of study: the first III–V based diluted magnetic semiconductors were produced in epitaxial films of (In, Mn)As grown on GaAs(100) substrates in 1989. An account is given of the magnetic behavior of these novel semi‐magnetic alloys at various carrier concentrations. Finally, magneto‐optical devices are presented in which the control of the carrier concentration by an electric field results in the manipulation of magnetic properties.
Photoconductivity in the columnar phases of a glassy discotic twin
Authors: Adam Dieter , Schuhmacher Peter , Simmerer Jürgen , Häußling Lukas , Paulus Wolfgang , Siemensmeyer Karl , Etzbach Karl‐Heinz , Ringsdorf Helmut , Haarer Dietrich
Published: December 2004

Processible organic materials exhibiting high charge carrier mobilities are a step closer with the development of liquid crystalline photoconducting materials. The mobilities have been measured in various phase regions over the temperature range from – 100 to 165°C and the influence of different annealing conditions assessed, indicating that these materials could soon compete with amorphous semiconductors in electronics applications.
Excited‐state complexes of conjugated polymers
Authors: Jenekhe Samson A.
Published: December 2004

Excited‐state charge‐transfer complexes (exciplexes) of conducting polymers can be formed by the absorption of light by the polymers (e.g. see Figure), and their generation is not restricted by the free‐energy requirements of their ground‐sate analos. This makes them of particular interest for applications ranging from xerographic photoconductors to nonlinear optics and LEDs.

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Metallomesogenic Polymers
Authors: Oriol Luis , Serrano José L.
Published: December 2004

Processible, molecularly ordered metal‐containing systms result when metallomesogens, liquid crystalline systems containing a metal atom, are integrated into the structure of a plymer (see Figure). The structural design of metallomesogenic polymers is reviewed and the potential applications of these interesting materials discussed.

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Synthesis and compositional tuning of the band properties of isostructural TMA–SnSxSe1–x−1 Nanoporous Materials
Authors: Ahari Homayoun , Ozin Geoffrey A. , Bedard Robert L. , Petrov Srebri , Young David
Published: December 2004

Crystalline, nanoporous tin chalcogenide semiconducting materials (see Figure) in which the band gap can be fine tuned chemically are reported. Variation of the proportions of slfur and selenium in the title materials results in the absorpton maxima red shifting with increasing selenium content over a range of 100 nm (350–450 nm).

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Electroluminescent properties of self‐assembled polymer thin films
Authors: Tian Jing , Thompson Mark E. , Wu Chung‐Chih , Sturm James C. , Register Richard A. , Marsella Michael J. , Swager Timothy M.
Published: December 2004

Novel photo‐ and electroluminescent polymers based on poly(p‐pyridyl vinylene), poly(p‐pyridinium vinylene) and their butyl‐substituted derivatives are reported. The materials exhibit good fluorescence quantum yields and the butyl derivatives are soluble in conventional organic solvents. Highly luminescent thin films of these materials can be prepared on a variety of substrates using a simple elecrostatic deposition technique and the high‐temperature annealing step required for PPV films is not required.
New angular molecular donor containing two tetrathiafulvalene (ttf) units fused to selenophene: synthesis, x‐ray structure, cyclic voltammetry and conducting charge transfer complex with TCNQ**
Authors: Wang Changsheng , Ellern Arkady , Becker James Y. , Bernstein Joel
Published: December 2004

Extended TTF‐based donor systems based for the first time on selenophene (see Fig.) are reported. Selenophene is an isologue of thiophene but has a stronger electron‐donating ability, a larger size, and a higher polarizability. These factors should lead to materials with increased bandwidth, improved dimensionality, increased electrical conductivity, and reduced on‐site Coulombic repulsion. The one‐pot synthesis of these materials and their complexation with TCNQ are presented

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αThiophene octamer as a new class of photo‐active material for photoelectrical conversion**
Authors: Noma Naoki , Tsuzuki Toshimitsu , Shirota Yasuhiko
Published: December 2004

α‐thiophene octamer (α‐8T) is shown to be a suitable materials for application as the p‐type semiconductor component in photovoltaic devices. Combined with a perylene pigment as the n‐type semicondctor, the α‐8T is used to produce a pn heterojunction cell which exhibits a fill factor of 0.5 ad a conversion efficiency of 0.6% for irradiation of while light, a performance comparable to that reported for copper‐ and titanyl‐phthalocyanine‐based devices. The application of α‐8T would allow vacuum deposition techniques to be used in the production of the cells.
Noncovalent synthesis of organic fibers**
Authors: Menger Fredric M. , Lee Stephen S. , Tao Xueliang
Published: December 2004

The self‐assembly of organic molecules into fibers (e.g. see Fig.) is reversible. In the dreams of chemists the exploitation of this phenomenon could lead, for example, to the use of bio‐compatible fibrous organics to simulate blood clots. Dissolution of the clot could be affected thermally or chemically. Recently developed technology which could make this sort of ting possible in the future is reviewed

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New conjugated polymer/sol‐gel glass composites: Luminescence and optical waveguides
Authors: Faraggi Erez Z. , Sorek Yoram , Levi Ofer , Avny Yair , Davidov Dan , Neumann Ronny , Reisfeld Renata
Published: December 2004

Composites of a sol‐gel glass and a conjugated polymer have the potential to combine their unique properties: the high stability and ease of preparation of the sol‐gel host and the optical fluorescence of the polymers. Two methods of preparation of such new composites are described, one of which successfully leads to composites with photoluminescence similar to that of homogeneous films of conjugated polymers. This result opens up new vistas in the fabrication of devices based on thin films of conjugated polymers using composite materials.
Fabrication of three‐dimensional micro‐structures: Microtransfer molding
Authors: Zhao Xiao‐Mei , Xia Younan , Whitesides George M.
Published: December 2004

Microtransfer molding is a new technique for rapidly fabricating micrometer‐scale structures over large areas (3.5 cm × 0.8 cm). This new technique, which involves the solidification of a liquid precursor in an elastomeric mold, can generate microstructures of organic polymers and ceramics such as that shown in the Figure on both planar and contoured surfaces and is able to make three‐dimensional structures layer by layer.

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Tools and strategies for Developing New Materials
Authors: Gür Turgut M.
Published: December 2004

The synergistic dependence of materials properties and performance upon structure and processing provides effective strategies for developing new materials for advanced technologies. This intimate interplay provides the central theme of this article. Advanced synthesis techniques, controlled microstructure, compositional tuning and theoretical predictions are powerful tools for searching for new materials or improved properties. These are discussed by selected examples including fullerenes, giant magnetoresistance multilayers, diamond and nitride films. The article also provides a brief overview of these materials and discusses their technological significance.
Aligned ZrO2(c)‐CaZrO3 eutectics grown by the laser floating zone method: Electrical and optical properties
Authors: Peña José I. , Merino Rosa I. , de la Fuente Germán F. , Orera Victor M.
Published: December 2004

Ceramic eutectics grown from the melt have great structural advantages compared to conventional ceramics and also properties that make them suitable for applications as electronic and optical materials. The preparation of ordered lamellar eutectics of ZrO2(c)CaZrO3 is described and the macroscopic and engineering characteristics of the material reported. The Figure shows an optical micrograph of a transverse section obtained in the transmission illumination mode.

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