bluuebunny/crossref_metadata_2025 huggingface dataset:
Healthcare professional acceptance of telemonitoring for chronic care patients in primary care
Authors: Asua José , Orruño Estibalitz , Reviriego Eva , Gagnon Marie Pierre
Published: November 2012

Background

A pilot experimentation of a telemonitoring system for chronic care patients is conducted in the Bilbao Primary Care Health Region (Basque Country, Spain). It seems important to understand the factors related to healthcare professionals’ acceptance of this new technology in order to inform its extension to the whole healthcare system.

This study aims to examine the psychosocial factors related to telemonitoring acceptance among healthcare professionals and to apply a theory-based instrument.

Methods

A validated questionnaire, based on an extension of the Technology Acceptance Model (TAM), was distributed to a total of 605 nurses, general practitioners and paediatricians. Logistic regression analysis was performed to test the theoretical model. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) were computed.

Results

A response rate of 44.3% was achieved. The original TAM model was good at predicting intention to use the telemonitoring system. However, the extended model, that included other theoretical variables, was more powerful. Perceived Usefulness, Compatibility, and Facilitators were the significant predictors of intention. A detailed analysis showed that intention to use telemonitoring was best predicted by healthcare professionals’ beliefs that they would obtain adequate training and technical support and that telemonitoring would require important changes in their practice.

Conclusion

The extended TAM explained a significant portion of the variance in healthcare professionals' intention to use a telemonitoring system for chronic care patients in primary care. The perception of facilitators in the organisational context is the most important variable to consider for increasing healthcare professionals’ intention to use the new technology.
Enhancement of mouse sperm motility by trophinin-binding peptide
Authors: Park Seong Kyu , Yoon Jiwon , Wang Ling , Shibata Toshiaki K , Motamedchaboki Khatereh , Shim Kyung Jun , Chang Mun Seog , Lee Seung Ho , Tamura Naoaki , Hatakeyama Shingo , Nadano Daita , Sugihara Kazuhiro , Fukuda Michiko N
Published: November 2012

Background

Trophinin is an intrinsic membrane protein that forms a complex in the cytoplasm with bystin and tastin, linking it microtubule-associated motor dynein (ATPase) in some cell types. Previously, we found that human sperm tails contain trophinin, bystin and tastin proteins, and that trophinin-binding GWRQ (glycine, tryptophan, arginine, glutamine) peptide enhanced motility of human sperm.

Methods

Immunohistochemistry was employed to determine trophinin protein in mouse spermatozoa from wild type mouse, by using spermatozoa from trophinin null mutant mice as a negative control. Multivalent 8-branched GWRQ (glycine, tryptophan, arginine, glutamine) peptide or GWRQ-MAPS, was chemically synthesized, purified by HPLC and its structure was confirmed by MALDI-TOF mass spectrometry. Effect of GWRQ-MAPS on mouse spermatozoa from wild type and trophinin null mutant was assessed by a computer-assisted semen analyzer (CASA).

Results

Anti-trophinin antibody stained the principal (central) piece of the tail of wild type mouse sperm, whereas the antibody showed no staining on trophinin null sperm. Phage particles displaying GWRQ bound to the principal piece of sperm tail from wild type but not trophinin null mice. GWRQ-MAPS enhanced motility of spermatozoa from wild type but not trophinin null mice. CASA showed that GWRQ-MAPS enhanced both progressive motility and rapid motility in wild type mouse sperm.

Conclusions

Present study established the expression of trophinin in the mouse sperm tail and trophinin-dependent effect of GWRQ-MAPS on sperm motility. GWRQ causes a significant increase in sperm motility.
MDP-based handover policy in wireless relay systems
Authors: Dang Xiaoyu , Wang Jin-Yuan , Cao Zhe
Published: November 2012

Wireless relay transmission has been considered as a supplementary technology for future wireless communication system, and handover is a key element in wireless relay transmissions to support users’ mobility. Handover failure will result in the forced termination of an ongoing call, and a good handover scheme will provide good system performance. This article focuses on the handover decision problem in wireless relay transmission systems. Initially, the architecture of a single-cell relay system is introduced. The handover decision problem is formulated as a Markov decision process (MDP). In the proposed model, a profit function is used to evaluate the quality-of-service of the chosen serving node, and a cost function is used to model processing load and signaling cost. Based on the profit and cost functions, the reward function is formulated. Moreover, the objective is to maximize the expected total reward per connection. The value iteration algorithm is employed to determine the optimal handover policy. Furthermore, the analysis is generalized to multi-cell relay systems. Numerical results show that the proposed MDP-based handover policy is well behaved in wireless relay systems.
Metabolic profiles characterizing different phenotypes of polycystic ovary syndrome: plasma metabolomics analysis
Authors: Zhao Yue , Fu Li , Li Rong , Wang Li-Na , Yang Yan , Liu Na-Na , Zhang Chun-Mei , Wang Ying , Liu Ping , Tu Bin-Bin , Zhang Xue , Qiao Jie
Published: November 2012

Background

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder accompanied with an increased risk of developing type 2 diabetes mellitus and cardiovascular disease; despite being a common condition, the pathogenesis of PCOS remains unclear. Our aim was to investigate the potential metabolic profiles for different phenotypes of PCOS, as well as for the early prognosis of complications.

Methods

A total of 217 women with PCOS and 48 healthy women as normal controls were studied. Plasma samples of subjects were tested using two different analytical platforms of metabolomics: 1H nuclear magnetic resonance (NMR) and gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS).

Results

Our results showed that carbohydrate, lipid and amino acid metabolisms were influenced in PCOS. The levels of lactate, long-chain fatty acids, triglyceride and very low-density lipoprotein were elevated, while glucose, phosphatidylcholine and high-density lipoprotein (HDL) concentrations were reduced in PCOS patients as compared with controls. Additionally, the levels of alanine, valine, serine, threonine, ornithine, phenylalanine, tyrosine and tryptophan were generally increased, whereas the levels of glycine and proline were significantly reduced in PCOS samples compared to controls. Furthermore, the ratio of branched-chain amino acid to aromatic amino acid concentrations (BCAA/AAA) in PCOS plasma was significantly reduced in PCOS patients and was insusceptible to obesity and insulin sensitivity.

Conclusions

Our results suggested that the enhanced glycolysis and inhibited tricarboxylic acid cycle (TAC) in women with PCOS. Decrease of BCAA/AAA ratio was directly correlated with the development of PCOS. Ovulatory dysfunction of PCOS patients was associated with raised production of serine, threonine, phenylalanine, tyrosine and ornithine. Elevated levels of valine and leucine, and decreased concentrations of glycine in PCOS plasma could contribute to insulin sensitivity and could be considered as the potential biomarkers for long-term risk assessment of diabetes mellitus.
Integration of time-resolved transcriptomics data with flux-based methods reveals stress-induced metabolic adaptation in Escherichia coli
Authors: Töpfer Nadine , Jozefczuk Szymon , Nikoloski Zoran
Published: November 2012

Background

Changes in environmental conditions require temporal effectuation of different metabolic pathways in order to maintain the organisms’ viability but also to enable the settling into newly arising conditions. While analyses of robustness in biological systems have resulted in the characterization of reactions that facilitate homeostasis, temporal adaptation-related processes and the role of cellular pathways in the metabolic response to changing conditions remain elusive.

Results

Here we develop a flux-based approach that allows the integration of time-resolved transcriptomics data with genome-scale metabolic networks. Our framework uses bilevel optimization to extract temporal minimal operating networks from a given large-scale metabolic model. The minimality of the extracted networks enables the computation of elementary flux modes for each time point, which are in turn used to characterize the transitional behavior of the network as well as of individual reactions. Application of the approach to the metabolic network of Escherichia coli in conjunction with time-series gene expression data from cold and heat stress results in two distinct time-resolved modes for reaction utilization—constantly active and temporally (de)activated reactions. These patterns contrast the processes for the maintenance of basic cellular functioning and those required for adaptation. They also allow the prediction of reactions involved in time- and stress-specific metabolic response and are verified with respect to existing experimental studies.

Conclusions

Altogether, our findings pinpoint the inherent relation between the systemic properties of robustness and adaptability arising from the interplay of metabolic network structure and changing environment.
K-NN query algorithm based on PB-tree with the parallel lines division
Authors: Tang Jine , Zhou ZhangBing , Wang Qun
Published: November 2012

Spatial index and query are enabling techniques for achieving the vision of the Internet of Things. K-NN is an algorithm which is used widely in spatial database. Traditional query algorithms use R-tree as the index structure and improve the query efficiency by using the measurement distance and pruning strategy. Based on the study of previous algorithms, this paper proposes a novel K-NN query algorithm based on PB-tree with the parallel lines division. PB-tree index is different from the traditional R-tree index, where PB-tree adopts parallel lines to divide the spatial region and uses parallel lines as the parent node. It is similar to the binary tree index structure and requires to query three small portions nearest to the queried object in each K-NN query. Therefore, the search range is narrowed and the query efficiency is enhanced. Experiments show that PB-tree is better than the traditional R-tree from the aspect of query performance. PB-tree can avoid the deficiency of a large number of overlap and coverage among odes in R-tree and multiple index paths when searching data objects, and hence PB-tree can find K-NN objects meeting the conditions quickly and efficiently in large data sets.
Spatial mapping and quantification of developmental branching morphogenesis
Authors: Short Kieran , Hodson Mark , Smyth Ian
Published: November 2012

Branching morphogenesis is a fundamental developmental mechanism that shapes the formation of many organs. The complex three-dimensional shapes derived by this process reflect equally complex genetic interactions between branching epithelia and their surrounding mesenchyme. Despite the importance of this process to normal adult organ function, analysis of branching has been stymied by the absence of a bespoke method to quantify accurately the complex spatial datasets that describe it. As a consequence, although many developmentally important genes are proposed to influence branching morphogenesis, we have no way of objectively assessing their individual contributions to this process. We report the development of a method for accurately quantifying many aspects of branching morphogenesis and we demonstrate its application to the study of organ development. As proof of principle we have employed this approach to analyse the developing mouse lung and kidney, describing the spatial characteristics of the branching ureteric bud and pulmonary epithelia. To demonstrate further its capacity to profile unrecognised genetic contributions to organ development, we examine Tgfb2 mutant kidneys, identifying elements of both developmental delay and specific spatial dysmorphology caused by haplo-insufficiency for this gene. This technical advance provides a crucial resource that will enable rigorous characterisation of the genetic and environmental factors that regulate this essential and evolutionarily conserved developmental mechanism.
Visual motion speed determines a behavioral switch from forward flight to expansion avoidance inDrosophila
Authors: Reiser Michael B. , Dickinson Michael H.
Published: November 2012

As an animal translates through the world, its eyes will experience a radiating pattern of optic flow in which there is a focus of expansion directly in front and a focus of contraction behind. For flying fruit flies, recent experiments indicate that flies actively steer away from patterns of expansion. Whereas such a reflex makes sense for avoiding obstacles, it presents a paradox of sorts because an insect could not navigate stably through a visual scene unless it tolerated flight towards a focus of expansion during episodes of forward translation. One possible solution to this paradox is that a fly's behavior might change such that it steers away from strong expansion, but actively steers toward weak expansion. In this study, we use a tethered flight arena to investigate the influence of stimulus strength on the magnitude and direction of turning responses to visual expansion in flies. These experiments indicate that the expansion-avoidance behavior exhibits a speed-dependent inversion. At slower speeds of expansion, flies exhibit an attraction to the focus of expansion, whereas the behavior transforms to expansion avoidance at higher speeds. Open-loop experiments indicate that this inversion of the expansion-avoidance response depends on whether or not the head is fixed to the thorax. The inversion of the expansion-avoidance response with stimulus strength has a clear manifestation under closed-loop conditions. Flies will actively orient toward a focus of expansion at low temporal frequency but steer away from it at high temporal frequency. The change in the response with temporal frequency does not require motion stimuli directly in front or behind the fly. Animals in which the stimulus was presented within 120° sectors on each side consistently steered toward expansion at low temporal frequency and steered toward contraction at high temporal frequency. A simple model based on an array of Hassenstein-Reichardt type elementary movement detectors suggests that the inversion of the expansion-avoidance reflex can explain the spatial distribution of straight flight segments and collision-avoidance saccades when flies fly freely within an open circular arena.
Mortality from desiccation contributes to a genotype-by-temperature interaction for cold survival inDrosophila melanogaster
Authors: Kobey Robert L. , Montooth Kristi
Published: November 2012

Survival at cold temperatures is a complex trait, primarily due to the fact that the physiological cause of injury may differ across degrees of cold exposure experienced within the lifetime of an ectothermic individual. In order to better understand how chill-sensitive insects experience and adapt to low temperatures, we investigated the physiological basis for cold survival across a range of temperature exposures from -4°C to 6°C in five genetic lines of the fruit fly, Drosophila melanogaster. Genetic effects on cold survival were temperature dependent and resulted in a significant genotype-by-temperature interaction for survival across cold temperature exposures that differ by as little as 2°C. We investigated desiccation as a potential mechanism of injury across these temperature exposures. Flies were dehydrated following exposures near 6°C, while flies were not dehydrated following exposures near -4°C. Furthermore, decreasing humidity during cold exposure decreased survival, and increasing humidity during cold exposure increased survival at 6°C, but not at -4°C. These results support the conclusion that in D. melanogaster there are multiple physiological mechanisms of cold-induced mortality across relatively small differences in temperature and that desiccation contributes to mortality for exposures near 6°C but not for subzero temperatures. Because D. melanogaster has recently expanded its range from tropical to temperate latitudes, the complex physiologies underlying cold tolerance are likely to be important traits in the recent evolutionary history of this fruit fly.
The role of glucocorticoids in naturally fasting grey seal (Halichoerus grypus) pups: dexamethasone stimulates mass loss and protein utilisation, but not departure from the colony
Authors: Bennett Kimberley A. , Fedak Mike A. , Moss Simon E. W. , Pomeroy Patrick P. , Speakman John R. , Hall Ailsa J.
Published: November 2012

Seals must manage their energy reserves carefully while they fast on land to ensure they go to sea with sufficient fuel to sustain them until they find food. Glucocorticoids (GC) have been implicated in the control of fuel metabolism and termination of fasting in pinnipeds. Here we tested the hypothesis that dexamethasone, an artificial GC, increases fat and protein catabolism, and induces departure from the breeding colony in wild, fasting grey seal pups. A single intramuscular dose of dexamethasone completely suppressed cortisol production for 24-72 hours, demonstrating activation of GC receptors. In experiment 1, we compared the effects of a single dose of dexamethasone or saline administered ten days after weaning on fasting mass and body composition changes, cortisol, blood urea nitrogen (BUN) and glucose levels, and timing of departure from the colony. In experiment 2, we investigated the effects of dexamethasone on short-term (5 days) changes in mass loss, body composition and BUN. In experiment 1, dexamethasone induced a short-lived increase in mass loss, but there was no difference in timing of departure between dexamethasone and saline treated pups (n = 10). In experiment 2, dexamethasone increased protein and water loss and prevented a decrease in BUN levels (n = 11). Our data suggest changes in cortisol contribute to regulation of protein catabolism in fasting seal pups, irrespective of the sex of the animal, but do not terminate fasting. By affecting the rate of protein depletion, lasting changes in cortisol levels could influence the amount of time seal pups have to find food, and thus may have important consequences for their survival.
Three cone opsin genes determine the properties of the visual spectra in the Japanese anchovy Engraulis japonicus (Engraulidae, Teleostei)
Authors: Kondrashev Sergei L. , Miyazaki Taeko , Lamash Nina E. , Tsuchiya Tohru
Published: November 2012

A complement of cone visual pigments was identified in the Japanese anchovy Engraulis japonicus, one of the engraulid fish species that has a retina specialized for polarization and color vision. The nature of the chromophore bound to opsin proteins was investigated using high performance liquid chromatography (HPLC). The opsin genes were then cloned and sequenced, and the absorption spectra of different types of cones were obtained by microspectrophotometry (MSP). Two green (EJ-RH2-1, EJ-RH2-2) and one red (EJ-LWS) cone opsin genes were identified and are presumably related to the Vitamin A1-based visual pigments (i.e., rhodopsins) with λmax values of 492, 474 and 512 nm for EJ-RH2-1, EJ-RH2-2, and EJ-LWS, respectively. The long and short cones from the ventro-temporal retinal zone consisted of a pure population of RH2 class gene-based pigments (λmax value of 492 nm). The long and short cones from other retinal areas and the lateral components of the triple cones possessed a mixture of RH2 and LWS class gene-based pigments that exhibited a λmax value approximately 502 nm. The central component of the triple cones contained only RH2 class gene-based pigments (λmax value of 474 nm). Thus, E. japonicus possesses a middle-wave range of spectral sensitivity and acquires different color vision systems in distinct visual fields. .
miR-206 regulates the growth of the teleost tilapia (Oreochromis niloticus) through the modulation of IGF-1 gene expression
Authors: Yan Biao , Zhao Liuhui , Guo Jintao , Zhao Jinliang
Published: November 2012

MicroRNAs (miRNAs) are ~22 nt noncoding RNAs that play an important role in regulating muscle development. Our previous study shows that miR-206 is specifically expressed in tilapia skeletal muscle, and exhibits dynamic expression pattern during different developmental stages. Here, we reveal that miR-206 emerges as a crucial regulator of tilapia growth. miR-206 loss of function contributes to the acceleration of tilapia growth. We identify IGF-1 as one of the direct regulatory targets of miR-206. miR-206 can directly regulate IGF-1 expression by targeting its 3’-UTR, and inhibition of miR-206 substantially increases IGF-1 mRNA level in vivo. Thus, miR-206 may be developed as a molecular marker to assist fish breeding. Key words: Nile tilapia, miR-206, growth performance, IGF-1
Amphiphilic Brush-Like Copolymers Involving Hydrophobic Amino Acid- and Oligopeptide-Side Chains for Optical Tumor Imaging In Vivo
Authors: Miki Koji , Nakano Katsuya , Matsuoka Hideki , Yeom Chan Joo , Harada Hiroshi , Hiraoka Masahiro , Ohe Kouichi
Published: November 2012

Amphiphilic brush-like copolymers having simple amino acids or oligopeptides and poly(ethylene glycol) as side chains were synthesized via ring-opening metathesis polymerization and further transformations. All of the synthesized copolymers formed spherical self-assemblies in water and their hydrodynamic diameters were 100–250 nm, as measured by dynamic light scattering. Amphiphilic polymers bearing leucine and valine can form stable spherical self-assemblies in water because of the synergistic effects of intermolecular hydrogen bonding and hydrophobic interaction. The oligomerization of leucine moieties and capping with the proper length of fatty acyl groups at an N-terminus could significantly affect both the stability and fluorescence intensity of near-infrared fluorescent (NIRF) dye-containing polymeric self-assemblies. All of the self-assemblies consisting of leucine- and oligoleucine-grafted copolymers with a NIRF indocyanine green dye and hydrophilic targeting agents showed low cytotoxicity in cell viability tests. Furthermore, self-assemblies consisting of N-acetylleucine-grafted copolymers with strong fluorescence could visualize a tumor site with high-contrast in vivo, while low contrast images were obtained by utilizing oligoleucine-grafted self-assemblies because of their weak fluorescence. These results indicate that the precise control of both the number of leucine moieties and the length of the fatty acyl groups is important to produce highly functionalized tumor-targeting vehicles delivering a NIRF dye.
Environmentally Friendly Inorganic Red Pigments Based on Bismuth Oxide
Authors: Wendusu  , Masui Toshiyuki , Imanaka Nobuhito
Published: November 2012

Novel inorganic red pigments based on bismuth oxide, [(Bi1−xErx)1−yFey]2O3 (0 < x ≤ 0.50, 0 < y ≤ 0.30), were synthesized by a conventional solid-state reaction method, and their color properties were characterized. The color of the sample depended on its composition, with the [(Bi0.72Er0.28)0.80Fe0.20]2O3 pigment having the most vivid red hue. The a* value corresponding to red chromaticity of the [(Bi0.72Er0.28)0.80Fe0.20]2O3 pigment was +30.9, which was greater than that of a commercial Fe2O3 pigment (a* = +28.9). Since these pigments are composed of nontoxic and safe elements, they can be effective alternatives to the conventional Fe2O3 pigment.
Industry Structure, Executive Pay, and Short-Termism
Authors: Thanassoulis John
Published: November 2012

This study outlines a new theory linking industry structure to optimal employment contracts and executive short-termism. Firms hire their executives using optimal contracts derived within a competitive labour market. To motivate effort, firms must use some variable remuneration. Such remuneration introduces a myopia problem: an executive would wish to inflate early expected earnings at some risk to future profits. To manage this short-termism, some bonus pay is deferred. Convergence in size among firms makes the cost of managing the myopia problem grow faster than the cost of managing the effort problem. Eventually, the optimal contract jumps from one deterring myopia to one tolerating myopia. Under some conditions, the industry partitions: the largest firms hire executives on contracts tolerant of myopia; smaller firms ensure myopia is ruled out.

This paper was accepted by Wei Xiong, finance.
Treatment Effectiveness and Side Effects: A Model of Physician Learning
Authors: Chan Tat , Narasimhan Chakravarthi , Xie Ying
Published: November 2012

In this paper we study how treatment effectiveness and side effects impact the prescription decision of a risk-averse physician, and how detailing and patient feedback help reduce the physician's uncertainty in these two attributes in the erectile dysfunction category. To separately identify the impacts of effectiveness and side effects, we augment the observed prescription choices with unique data on self-reported reasons for switching in our estimation. Results show that the two new drugs Levitra and Cialis have higher mean effectiveness than the existing drug Viagra, but physicians have large uncertainty regarding the effectiveness for Levitra and side effects for Cialis. Detailing is effective in reducing the uncertainty for effectiveness but much less so for side effects. Based on the results, we investigate the roles of effectiveness and side effects in physicians' prescription choices, and the importance of detailing for new entrants in competing with incumbent drugs.

This paper was accepted by J. Miguel Villas-Boas, marketing.
Zero-Variance Importance Sampling Estimators for Markov Process Expectations
Authors: Awad Hernan P. , Glynn Peter W. , Rubinstein Reuven Y.
Published: November 2012

We consider the use of importance sampling to compute expectations of functionals of Markov processes. For a class of expectations that can be characterized as positive solutions to a linear system, we show there exists an importance measure that preserves the Markovian nature of the underlying process, and for which a zero-variance estimator can be constructed. The class of expectations considered includes expected infinite horizon discounted rewards as a particular case. In this setting, the zero-variance estimator and associated importance measure can exhibit behavior that is not observed when estimating simpler path functionals (like exit probabilities). The zero-variance estimators are not implementable in practice, but their characterization can guide the design of a good importance measure and associated estimator by trying to approximate the zero-variance ones. We present bounds on the mean-square error of such an approximate zero-variance estimator, based on Lyapunov inequalities.
Oxygen Saturation Screening for Critical Congenital Heart Disease
Authors: Govindaswami Balaji , Jegatheesan Priya , Song Dongli
Published: November 2012

Critical congenital heart disease (CCHD) refers to lesions of the cardiovascular system, present at birth, which if left untreated in early infancy, will severely compromise the infant’s well-being and survival. Transposed great arteries, hypoplastic left heart, total anomalous pulmonary venous drainage, coarctation of the aorta, and interrupted aortic arch account for more than 70% of CCHD. Until recently, clinical examination followed by blood gas analysis (100% oxygen challenge) and echocardiogram have been the mainstays for diagnosis. However, these methods are unsatisfactory in preventing missed diagnosis before discharge in hospital-born infants. Prenatal diagnosis results in 25% to 50% detection of CCHD in the United States at the present time. In the last 10 to 15 years, noninvasive transcutaneous pulse oximetry has provided the means and impetus for blood oxygen saturation screening as an adjunct to traditional screening methods. It now seems that sufficient evidence exists to embrace universal oxygen saturation screening as one of the newborn screening tests before discharge from the hospital. The optimal method for universal oxygen saturation screening remains debatable, continues to be studied, and is evolving. Nevertheless, the current state of universal oxygen saturation screening should help provide reassurance to the scientific, medical, and health policy communities that this is yet another example of good preventive medicine at work in pediatrics and newborn medicine.
Antiretroviral effect of 4-thio-uridylate against human immunodeficiency virus type 1
Authors: Kanizsai Szilvia , Ghidán Ágoston , Ongrádi Joseph , Nagy Károly
Published: November 2012

Antiretroviral effect of thiolated nucleotide 4-thio-uridylate (S4UMP, designated as UD29) against human immunodeficiency virus type 1 (HIV-1) have been quantitatively determined in cell-based viral infectivity assays. In syntitium inhibition assay on MT-2 human T-cell line UD29 prevented cell fusion and formation of syntitia induced by HIV-1IIIBwith IC50values of 11.7 μg/ml. In a single-cycle viral infection assay (MAGI assay) UD29 proved to have a potent inhibitory effect against HIV-1IIIBon HeLaCD4-LTR/β-gal cells, which was dose dependent with IC50values of 4.75 μg/ml and IC90of 39.7 μg/ml. UD29 showed a most prominent antiviral effect when administered 30 min prior HIV-1 infection. As HIV entry requires thiol/disulfide exchange process, results suggest that reactive -SH group of enol-form of the thiolated nucleotide may interfere with the function of cell surface proteins. UD29 cannot penetrate into cells and may have an interactive role in redox processes active in viral entry.
Influence of mesh size and truncation order on reconstruction of impact force on composite elastic beams
Authors: El-Bakari A. , Dkiouak R. , Khamlichi A. , Jacquelin E. , Limam A.
Published: November 2012

Reconstructing impact forces can improve considerably structural health monitoring as the extent of damage can be better made out. In this work an inverse problem formulation to identify the pressure generated by a non punctual impact is investigated. Considering the case of linear elastic layered composite structures, reconstruction of impact pressure is performed through a finite element model of the structure and impulse response functions between the impact zone and sensors placed at known positions. Assuming that the pressure is uniform, reconstruction is carried out by regularized deconvolution based on generalized singular value decomposition. The infl uence of mesh size, modal truncation and time sampling on the reconstructed pressure is discussed.
The experimental study of the hybrid fixation in ACL reconstruction
Authors: Cofaru I. I. , Husi G. , Cofaru N. F. , Roman M. D.
Published: November 2012

The article is approaching an interesting topic regarding ACL reconstruction using the hamstring tendons (semitendinosus and gracilis) as the graft. The initial graft fixation after ACL reconstruction is mechanical and it must assure the stability of the system until the biologic integration takes place. No fixation system is as strong as the native ACL insertion. Therefore, hibrid fixation like an improvement of simple fixation is a field worth studying. The fixation shown in this article is the Hybrid fixation consisting of direct fixation with interference screw and an extra cortical fixation over a cortical screw.
Supplementary Cementitious Materials for Concrete: Characterization Needs
Authors: Juenger Maria , Provis John L. , Elsen Jan , Matthes Winnie , Hooton R. Doug , Duchesne Josée , Courard Luc , He Huan , Michel Frédéric , Snellings Ruben , Belie Nele De
Published: November 2012

A wide variety of materials are currently used as supplementary cementitious materials (SCMs) for concrete, including natural materials and byproducts from various industries. Historically, natural SCMs, mostly derived from volcanic deposits, were common in concrete. In recent years, the dominant SCMs have been industrial by-products such as fly ash, ground granulated blast furnace slag (GGBFS), and silica fume. There is currently a resurgence of research into historic and natural SCMs, as well as other alternative SCMs for many reasons. The primary benefits of SCM use in improvement of long-term mechanical performance, durability, and sustainability are widely accepted, so local demand for these materials can exceed supply. This paper describes some of the SCMs that are attracting attention in the global research community and the properties and characteristics of these materials that affect their performance. Special attention is paid to the importance and demands of material characterization. Many SCMs do not necessarily lend themselves to characterization methods used in standardized test methods, which sometimes fail to describe the properties that are most important in predicting reactivity.
Towards a Bacteria-Based Agent to Make Concrete Self-Healing
Authors: Mors Renee M. , Jonkers Henk M.
Published: November 2012

A bacteria-based healing agent for concrete is currently under development in the Microlab of TU Delft. The agent consists of organic mineral precursor compound and bacteria in a protective reservoir. Cracks in the concrete matrix may be sealed and blocked by calcium carbonate based crystals, formed by bacterial conversion of mineral precursor compound. Given the solubility of the agent components, healing agent material may be prematurely released during the wet mixing stage, potentially influencing cement hydration and functionality of other concrete additions. Several materials have been selected as potential mineral precursor compound, being organic salts and a carbohydrate. Tests on standard mortar specimens show that strength development is not compromised when calcium lactate is added to the standard mixture. Calcium lactate was added to the mortar mixture either pure or in combination with a superplasticizer, either based on sulfonated naphthalene or modified polycarboxylate ether, to determine possible interferential effects.
Chloride Diffusion in Blended Cement Concrete Made with Quartzite Recycled Aggregate
Authors: Zega Claudio J. , Villagrán-Zaccardi Yury A. , Di Maio Ángel A.
Published: November 2012

Using waste materials as aggregate for new concrete production is a growing tendency, because of several environmental problems. Recycled coarse aggregate (RCA) obtained from crushing waste concrete has lower density and greater absorption than natural aggregate, because of the higher porosity of the mortar attached to the RCA particles. Compressive strength level achieved in recycled concrete may be similar to that of conventional concrete. On the other hand, durable performance of recycled concrete is variable, and diverse evidence can be found in literature for different durability issues. In this paper, chloride ingress in conventional and recycled concrete, made with quartzite aggregate and blended Portland cement is evaluated when immersed in NaCl solution. Two strength levels (21 and 35 MPa) and two contents of RCA (25 and 75%), as substitute of natural quartzite aggregate, were considered. The chloride diffusion coefficient and the relationship between water-soluble chloride and bound chloride are analyzed.
Estimation of the Crystallinity of P-type Hydrogenated Nanocrystalline Cubic Silicon Carbide by Conductive Atomic Force Microscopy
Authors: Hamashita Daisuke , Kurokawa Yasuyoshi , Konagai Makoto
Published: November 2012

P-type hydrogenated nanocrystalline cubic silicon carbide is a promising material for the emitter of n-type crystalline silicon heterojunction solar cell due to its lower light absorption and wider bandgap of 2.2 eV. The electrical properties of hydrogenated nanocrystalline cubic silicon carbide can be influenced by its crystallinity. In this study, we propose the use of conductive atomic force microscopy (Conductive-AFM) to evaluate the crystalline volume fraction (fc) of p-nc-3C-SiC:H thin films (20∼30 nm) as a new method instead of Raman scattering spectroscopy, X-ray diffraction, and spectroscopic ellipsometry.
To Bias or Not to Bias? An “How-To” Guide for Spectral Response Measurements of Thin Film Multi-Junction Photovoltaic Modules
Authors: Pravettoni Mauro
Published: November 2012

Current-matching between junctions in a multi-junction photovoltaic device is fundamental for its performance prediction: the measurement of the spectral response of each junction provides a valuable information to optimize the device performance. Various aspects make spectral response measurements of such devices particularly challenging. In this work these aspects are analysed theoretically and guidelines to avoid their impact in the experimental practice are given.
Gas Phase Electrodeposition: A Programmable Localized Deposition Method for Rapid Combinatorial Investigation of Nanostuctured Devices and 3D Bulk Heterojunction Photovoltaic Cells
Authors: Lin En-Chiang , Fang Jun , Jacobs Heiko O.
Published: November 2012

This article applies a recently discovered gas phase nanocluster electrodeposition process to the formation and combinatorial improvement of 3D bulk heterojunction photovoltaic cells. The gas phase deposition process used here is a single reactor system that forms charged nanoclusters (gold, silver, tungsten, and platinum) at atmospheric pressure. The clusters deposit onto selected surface areas with sub 100 nm lateral resolution using a programmable concept similar to liquid phase electrodeposition such that biased electrodes turn ON or OFF deposition in selected areas. Continued deposition of the nanoparticles results in a tower array with different lengths and density on a single substrate which is used as contacts to the active organic layer of 3D bulk heterojunction photovoltaic cells. Applying a combinatorial approach identifies in a massively parallel way electrode designs and topologies that improve light scattering, absorption, and minority carrier extraction. We report photovoltaic cells with higher and denser nanocluster tower arrays that improve the power conversion efficiency of bulk heterojunction photovoltaic cells by approximately 47.7%.
In-Situ Raman Characterization of SOFC Anodes
Authors: Maher Robert C. , Offer Gregory , Brandon Nigel P. , Cohen Lesley F.
Published: November 2012

Solid oxide fuel cells (SOFCs) have many advantages when compared to other fuel cell technologies, particularly for distributed stationary applications. As a consequence they are becoming ever more economically competitive with incumbent energy solutions. However, as with all technologies, improvements in durability, efficiency and cost is required before they become feasible alternatives. Such improvements are enabled through improved understanding of the critical material interactions occurring during operation. Raman spectroscopy is a noninvasive and non-destructive optical characterization tool which is ideally suited to the study of these critical chemical processes occurring within operational SOFCs. In this paper we will discuss advantages of using Raman characterization for understanding these important chemical processes occurring within SOFCs. We will present the specific examples of the type of measurement possible and discuss the direction of future research.
Development of a Silver Based Stable Current Collector for Solid Oxide Fuel Cell Cathodes
Authors: Sarikaya Ayhan , Petrovsky Vladimir , Dogan Fatih
Published: November 2012

Long term stability has been a crucial issue for the future applications of the solid oxide fuel cells (SOFCs). Current collectors for the cathodes have been among the most vulnerable components of the SOFCs due to their operation in oxidizing atmospheres at relatively high temperatures. Ag and Ag based LSM (lanthanum-strontium manganite) composites were studied to develop highly stable and low-cost current collectors compatible with other fuel cell components. In this study, no degradation was observed in the electrical conductivity and the porous microstructure of the Ag-LSM composite current collectors after 600 hours of operation at 800oC in air.
Layer Transfer and Simultaneous Activation of Phosphorus Atoms in Silicon Films by Near-Infrared Semiconductor Diode Laser Irradiation
Authors: Kobayashi Yoshitaka , Sakaike Kohei , Nakamura Shogo , Ikeda Mitsuhisa , Ohta Akio , Higashi Seiichiro
Published: November 2012

Layer transfer and simultaneous activation of phosphorus atoms in Si films induced by semiconductor diode laser (SDL) irradiation have been investigated. Phosphorus-doped a-Si films supported by columns on a starting substrate (quartz) and a counter substrate (glass) were closely contacted face-to-face, and an 812 nm light from a SDL was irradiated to the a-Si films from the backside of the starting substrate. After SDL irradiation, 20μm wide and 1000μm long Si films were transferred to the counter substrate and were crystallized simultaneously. From optical microscope images, it was confirmed that the original form was completely maintained after the film transfer. The electrical conductivity of transferred Si film was as high as 708 S/cm. Hall measurement of the films revealed very high electron concentration of 9.5×1020 cm-3, which indicated efficient doping is achieved by the laser transfer technique.
Highly Transparent AZO/Ag/AZO Multilayer Front Contact for n-i-p Silicon Thin-Film Solar Cells
Authors: Theuring Martin , Vehse Martin , Noureddine Ibrahim , von Maydell Karsten , Agert Carsten
Published: November 2012

Oxide-metal-oxide structures are an alternative to single material transparent electrical contacts. Among other advantages, these multilayer systems provide good conductivity and transmittance, even when fabricated at room temperature. Low temperature processing is a requirement for silicon thin-film solar cells on various flexible substrates. The design and fabrication of oxide-metal-oxide structures based on ZnO:Al and Ag are investigated in this work. Further the integration of an optimized multilayer electrode into an amorphous silicon solar cell in substrate configuration was performed. Measurement results and possible loss mechanisms are discussed.
Development of Low-Temperature Ambipolar a-SiGe:H Thin-Film Transistors Technology
Authors: Dominguez Miguel A. , Rosales Pedro , Torres Alfonso , Moreno Mario
Published: November 2012

We present the fabrication and characterization of low-temperature ambipolar thin-film transistors (TFTs) based on hydrogenated amorphous silicon-germanium (a-SiGe:H) as active layer. Inverted staggered a-SiGe:H TFTs were fabricated on Corning glass. Spin-on glass silicon dioxide was used as gate dielectric to improve the quality of the dielectric-semiconductor interface. For positive gate bias the transfer characteristic showed n-type TFT behavior, while for negative gate bias p-type behavior was observed. The n-type region exhibits subthreshold slope of 0.45 V/decade while the p-type region shows a subthreshold slope of 0.49 V/decade.
Effect of DBD plasma on human cells in presence of osmolytes and denaturant
Authors: Kaushik Nagendra Kumar , Attri Pankaj , Choi Eun-Ha , Kaushik Neha
Published: November 2012

Non thermal plasma is emerging as a novel tool for the treatment of living tissues for biological and medical purpose. In this study we described the effect of DBD (dielectric barrier discharge) plasma on both cancer and normal cell line in presence of osmolytes. Osmolytes having unique protective metabolic roles and also found in animal body, they are acting as antioxidants, providing redox balance, detoxifying sulfide, protect macromolecules, enhance protein folding and regulate cell volume. Based on these interesting properties of osmolytes, non thermal plasma in presence of osmolytes appears to provide a new outlook. Results of this study reveals that osmolytes in presence of plasma act as protecting agent for normal cells however, not to cancer cells in the presence of plasma. The main goal of this study is to protect normal cells from the toxic effect of DBD plasma.
Study of Atmospheric Microplasma for Plasma-Life Science
Authors: Shimizu Kazuo , Tatematsu Shigeki , Fukunaga Hodaka , Blajan Marius
Published: November 2012

Atmospheric microplasma has been intensively studied for various application fields, since this technology has features shown here: generated around only 1 kV under atmospheric pressure,discharge gap of only 10 to 100mm,dielectric barrier discharge. Low discharge voltage atmospheric plasma processis an economical and effective solution forvarious applications such as indoor air control including sterilization, odor removal, surface treatment, and would be suitable for plasma-life science field such as medical application.

In thispaper, the basic study for plasma-life science will be presented. One life science application of microplasma is “sterilization”. The sterilization process was carried out with active species generated between themicroplasmaelectrodes.The active species were observed by emission spectrometry. The spectra showed the existence of active species, and the microplasma had typical characteristics of non-thermal plasma. Sterilization of E. coli was confirmed after microplasma treatment with Ar gas. The bacteria shape was changed after the microplasma process. The other application is “Surface treatment” by long life active species of materials which used for the medical field. The targets are glass, polymer film and others could be also possible.

The process is known as remote microplasma sterilization method. Microplasma generated by both air and Ar are effective for sterilization. Observation by the SEM images shows the E. coli had a shrunked shape after the microplasma treatment.

The contact angle of a water droplet on the polymer surface was measured to estimate its hydrophilicity. The relation between the contact angle and treatment time was investigated. Contact angle decreased from 75.6° to 45.6° after 10 s of treatment.
A Novel Method for Low-Resistivity Metal-Interconnection by Using Metallic Functional Liquids and Catalytically Generated Hydrogen Atoms
Authors: Kieu Nguyen T. T. , Ohdaira Keisuke , Shimoda Tatsuya , Matsumura Hideki
Published: November 2012

A novel method to make low-resistivity metal lines in assembled silicon (Si) integrated circuit (IC) chips or other semiconductor chips with high-speed and low-cost is demonstrated. In the method, functional silver (Ag)-liquid (Ag-ink) which contains Ag nanoparticles (NPs) in organic solution is used to draw metal-lines in trenches formed on a plastic substrate by imprint technology. Surface energy of trenches is modified by exposing the substrate to ultra-violet (UV) light with the purpose of concentrating the functional Ag-ink into trenches by capillary effect in order to connect with electrodes of Si chips. The resistivity of such metal-lines can be lowered to 4×10-6 Ωcm by exposing the Ag metal-lines to hydrogen (H) atoms generated by catalytic cracking reaction with a heated tungsten catalyzer. X-ray photoelectron spectroscopy (XPS) proves that H atoms can remove organic compounds surrounding Ag NPs, resulting in the low-temperature sintering of NPs as confirmed by scanning electron microscopy (SEM). The method is promising for low-cost fabricating of IC cards or other electronic devices utilizing assemble of many semiconductor chips.