bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiofrequency catheter ablation of macroreentrant ventricular tachycardia after corrective surgery for tetralogy of Fallot
Authors: Chinushi Masaomi , Saitou Osamu , Furushima Hiroshi
Published: April 2014

Ventricular tachycardia (VT) may occur in patients after corrective surgery for tetralogy of Fallot (ToF), and this can be a cause of sudden cardiac death. Macroreentrant VT is a unique mechanism in these patients, although other mechanisms are involved in VT development. Owing to advances in electrophysiological knowledge and medical technology, macroreentrant VT after corrective surgery for ToF can be treated by catheter ablation. In the macroreentrant circuit of VT, several critical isthmuses (types 1–4) could be included, and these are supported by anatomical obstacles and operative interventions in the right ventricle. Linear radiofrequency (RF) application through the critical isthmus can terminate and prevent the recurrence of macroreentrant VT. Among the critical isthmuses, the type 1 isthmus (between the right ventricular outflow scar and tricuspid annulus) is the most common, but compared with the other types of isthmuses, it is longer so and has a thicker myocardium. Therefore, higher‐energy RF application using irrigation and/or large‐tip ablation catheters is usually required to complete the linear conduction block. Since other isthmuses may simultaneously work as critical components of the macroreentrant circuit, detailed mapping is encouraged before starting RF application in the type 1 isthmus. Since long‐term evidence of the effectiveness of catheter ablation for VT in patients after ToF repair is limited, hybrid treatment with implantable cardioverter defibrillators (ICDs) would be a reasonable strategy for secondary prevention of cardiac events, such as that in patients with other underlying heart diseases. Indications of electrophysiological study, catheter ablation, and/or ICD therapy for primary prevention of sudden cardiac death should be further examined in high‐risk patients after ToF repair.
Breast cancer prognosis predicted by nuclear receptor‐coregulator networks
Authors: Doan Tram B. , Eriksson Natalie A. , Graham Dinny , Funder John W. , Simpson Evan R. , Kuczek Elizabeth S. , Clyne Colin , Leedman Peter J. , Tilley Wayne D. , Fuller Peter J. , Muscat George E.O. , Clarke Christine L.
Published: April 2014

Although molecular signatures based on transcript expression in breast cancer samples have provided new insights into breast cancer classification and prognosis, there are acknowledged limitations in current signatures. To provide rational, pathway‐based signatures of disrupted physiology in cancer tissues that may be relevant to prognosis, this study has directly quantitated changed gene expression, between normal breast and cancer tissue, as a basis for signature development. The nuclear receptor (NR) family of transcription factors, and their coregulators, are fundamental regulators of every aspect of metazoan life, and were rigorously quantified in normal breast tissues and ERα positive and ERα negative breast cancers. Coregulator expression was highly correlated with that of selected NR in normal breast, particularly from postmenopausal women. These associations were markedly decreased in breast cancer, and the expression of the majority of coregulators was down‐regulated in cancer tissues compared with normal. While in cancer the loss of NR‐coregulator associations observed in normal breast was common, a small number of NR (Rev‐ERBβ, GR, NOR1, LRH‐1 and PGR) acquired new associations with coregulators in cancer tissues. Elevated expression of these NR in cancers was associated with poorer outcome in large clinical cohorts, as well as suggesting the activation of ERα ‐related, but ERα‐independent, pathways in ERα negative cancers. In addition, the combined expression of small numbers of NR and coregulators in breast cancer was identified as a signature predicting outcome in ERα negative breast cancer patients, not linked to proliferation and with predictive power superior to existing signatures containing many more genes. These findings highlight the power of predictive signatures derived from the quantitative determination of altered gene expression between normal breast and breast cancers. Taken together, the findings of this study identify networks of NR‐coregulator associations active in normal breast but disrupted in breast cancer, and moreover provide evidence that signatures based on NR networks disrupted in cancer can provide important prognostic information in breast cancer patients.
Turbulent drag reduction through oscillating discs
Authors: Wise Daniel J. , Ricco Pierre
Published: April 2014

The changes in a turbulent channel flow subjected to sinusoidal oscillations of wall flush-mounted rigid discs are studied by means of direct numerical simulations (DNS). The Reynolds number is ${Re}_{\tau }=180$, based on the friction velocity of the stationary-wall case and the half-channel height. The primary effect of the wall forcing is the sustained reduction of wall-shear stress, which reaches a maximum of 20 %. A parametric study on the disc diameter, maximum tip velocity, and oscillation period is presented, with the aim of identifying the optimal parameters which guarantee maximum drag reduction and maximum net energy saving, the latter computed by taking into account the power spent to actuate the discs. This may be positive and reaches 6 %. The Rosenblat viscous pump flow, namely the laminar flow induced by sinusoidal in-plane oscillations of an infinite disc beneath a quiescent fluid, is used to predict accurately the power spent for disc motion in the fully developed turbulent channel flow case and to estimate localized and transient regions over the disc surface subjected to the turbulent regenerative braking effect, for which the wall turbulence exerts work on the discs. The Fukagata–Iwamoto–Kasagi identity is employed effectively to show that the wall-friction reduction is due to two distinguished effects. One effect is linked to the direct shearing action of the near-wall oscillating-disc boundary layer on the wall turbulence, which causes the attenuation of the turbulent Reynolds stresses. The other effect is due to the additional disc-flow Reynolds stresses produced by the streamwise-elongated structures which form between discs and modulate slowly in time. The contribution to drag reduction due to turbulent Reynolds stress attenuation depends on the penetration thickness of the disc-flow boundary layer, while the contribution due to the elongated structures scales linearly with a simple function of the maximum tip velocity and oscillation period for the largest disc diameter tested, a result suggested by the Rosenblat flow solution. A brief discussion on the future applicability of the oscillating-disc technique is also presented.
Relationship Quality, Work-Family Stress, and Mental Health Among Australian Male Mining Industry Employees
Authors: McPhedran Samara , De Leo Diego
Published: April 2014

Australia is one of the world's foremost mining nations. While the economic and employment benefits of the mining industry are well documented, potentially negative aspects of mining industry employment are less understood. It has been suggested that mining industry workers may be more likely than workers in other occupations to experience relationship problems and work-family stress, but there is very little empirical study examining this proposal. Data from the nationally representative Household, Income, and Labour Dynamics in Australia (HILDA) survey were used to compare males employed in the Australian mining industry with males working in other occupations, on indices of relationship quality and work-family balance, as well as mental and emotional health. Employment in the resources sector was not associated with poorer outcomes on these measures, relative to other occupations. These results suggest that hypothesised connections between mining industry employment and relationship/family stress require careful examination.
Heat shock suppresses mating and sperm transfer in the rice leaf folder Cnaphalocrocis medinalis
Authors: Liao H.J. , Qian Q. , Liu X.D.
Published: April 2014

Temperature is a key environmental factor in determining the population size of Cnaphalocrocis medinalis in summer. High temperatures inhibit survival, development and fecundity of this insect. However, biological responses of female and male adults to heat shock, and physiological mechanism of high temperature suppressing population development are still ambiguous. We experimentally tested the impact of heat shock (5 h day−1) on biological traits, spermatogenesis and sperm transfer of adults of C. medinalis. The result showed that heat exposure to 39 and 40 °C for 5 h reduced longevity and copulation frequency of adults, and hatchability of eggs. Immediate survival rate of males was lower than that of females after 3 days of exposure to 41 °C. The oviposition period, copulation frequency, fecundity of adults and hatchability of eggs were significantly lower when male adults were exposed to 40 or 41 °C for 3 days. Heat shock decreased frequency and success rate of mating when males were exposed, and it also resulted in postponement of mating behaviour and prolongation of mating duration as both the female and male adults were exposed. Heat shock did not affect spermatogenesis, but significantly inhibited sperms maturation. Moreover, males could not ejaculate sperm into females during copulation when these male moths received heat shock. Heat shock remarkably suppressed mating behaviour and sperm transfer, which led to a dramatic decline of rice leaf folder populations.
Contrasting perceptions of ecosystem services of an African forest park
Authors: HARTTER JOEL , SOLOMON JENNIFER , RYAN SADIE J. , JACOBSON SUSAN K. , GOLDMAN ABE
Published: April 2014

Traditionally, conservation programmes assume that local peoples’ support for parks depends on receiving material benefits from foreign exchange, tourism, development and employment. However, in the case of forest parks in Africa, where annual visitation can be small, local support may instead result from ecosystem services. Kibale National Park, a forest park in Uganda, demonstrates that people appreciate parks in ways that are seldom cited nor explored. Public perceptions of benefits accrued from Kibale were explored using two different sampling techniques: a community census and a geographic sample. In both surveys, over 50% of respondents perceived benefits provided by Kibale National Park, and over 90% of those who perceived benefits identified ecosystem services, whereas material benefits were cited less frequently. Multimodel selection on a suite of general linear models for the two different sampling methods provided a comparison of factors influencing perceptions of ecosystem services. Perceptions of Park benefits were influenced by geography, household and respondent characteristics, and perception of negative impacts from the Park. Perceived ecosystem benefits played an important role in the way the Park was viewed and valued locally. Parks have considerable impacts on neighbouring communities, and their long-term political and economic sustainability depends on managing these relationships well. Since local people have the most to gain or lose by conserving neighbouring parks, analyses that incorporate the perceptions of local people are essential to management and sustainability of park landscapes.
Systematic detection and association ofEntamoebaspecies in stool samples from selected sites in India
Authors: NATH J. , BANYAL N. , GAUTAM D. S. , GHOSH S. K. , SINGHA B. , PAUL J.
Published: April 2014

This study developed a fast and high throughput dot-blot technique to evaluate the presence ofEntamoebain stool samples (n = 643) followed by a PCR-based method to validate and differentiate the two speciesE. histolyticaandE. dispar. The prevalence rate of the parasite has been detected in a cross-sectional study carried out in the population of the Eastern and Northern parts of India. Of the various demographic features, prevalence was highest in the monsoon season (P = 0·017), in the <15 years age group (P = 0·015). In HIV-positive individuals, the prevalence rate was significantly high (P = 0·008) in patients with a CD4 cell count <200 as well as in patients without antiretroviral therapy (ART) (P = 0·011). Our analysis further confirmed that risk factors such as toilet facilities, living conditions, hygienic practices, drinking water source, occupation and level of education are important predictors as they were found to contribute significantly in the prevalence of the parasite.
Recanalisation of the left superior caval vein after Fontan procedure: not so rare complication: possibilities of percutaneous closure using various devices
Authors: Kusa Jacek , Szydlowski Leslaw , Nowakowska Ewa , Skierska Agnieszka
Published: April 2014

Aim: Evaluation of possibilities of percutaneous closure of recanalised left superior caval vein after total cavopulmonary connection.Methods and Results: We analysed 19 patients after total cavopulmonary connection catheterised because of a sudden increase of desaturation. In four of them, the recanalisation of the left superior caval vein was identified. For this reason, the balloon occlusion tests of the veins were made temporarily. In all cases, the haemodynamic status of patients did not change, and arterial oxygen saturation increased significantly. Thus, using different types of implants, these veins were closed effectively in all patients. During the short-term follow-up, the effectiveness of treatments and constantly maintaining a high level of saturation were confirmed.Conclusions: Meticulous investigation of unclear causes of desaturation in cyanotic patients after Fontan completion is necessary. Almost all causes of desaturation, including recanalised additional left superior caval vein, can be effectively treated percutaneously.
Severe coarctation of the aorta in a 900 g donor of twin–twin transfusion newborn with successful repeated transcatheter angioplasty: a case report
Authors: Al-Ammouri Iyad , Jaradat Saba , Radwan Jinan
Published: April 2014

We present a case of severe aortic coarctation in a donor of twin–twin transfusion syndrome. Patients underwent two angioplasty procedures at age 7 and 47 days, weighing 900 and 1500 g, respectively. Umbilical artery approach was used in the first procedure, and femoral artery approach was used in the second. Follow-up at the age of 13 months showed no recurrence of coarctation.
Validity and reliability of the Arabic version of the Household Food Insecurity Access Scale in rural Lebanon
Authors: Naja Farah , Hwalla Nahla , Fossian Talar , Zebian Dina , Nasreddine Lara
Published: April 2014

Objective

To assess the validity and reliability of the Arabic version of the Household Food Insecurity Access Scale (HFIAS) in rural Lebanon.

Design

A cross-sectional study on a sample of households with at least one child aged 0–2 years. In a one-to-one interview, participants completed an adapted Arabic version of the HFIAS. In order to evaluate the validity of the HFIAS, basic sociodemographic information, anthropometric measurements of the mother and child, and dietary intake data of the child were obtained. In order to examine reproducibility, the HFIAS was re-administered after 3 months.

Setting

Rural Lebanon.

Subjects

Mother and child pairs (n 150).

Results

Factor analysis of HFIAS items revealed two factors: ‘insufficient food quality’ and ‘insufficient food quantity’. Using Pearson's correlation, food insecurity was inversely associated with mother's and father's education levels, number of cars and electrical appliances in the household, income, weight-for-age and length-for-age of the child and the child's dietary adequacy. In contrast, mother's BMI and crowding index were positively associated with food insecurity scores (P < 0·05 for all correlations). Cronbach's α of the scale was 0·91. A moderate correlation was observed between the two administrations of the questionnaire (intra-class correlation = 0·58; P < 0·05).

Conclusions

Our findings indicated that the adapted Arabic version of the HFIAS is a valid and reliable tool to assess food insecurity in rural Lebanon, lending further evidence to the utility of the HFIAS in assessing food insecurity in culturally diverse populations.
The Most Important Topic Political Scientists Are Not Studying: Adapting to Climate Change
Authors: Javeline Debra
Published: April 2014

Few, if any, political scientists currently study climate change adaptation or are even aware that there is a large and growing interdisciplinary field of study devoted not just to mitigating greenhouse gas emissions but to reducing our vulnerability to the now-inevitable impacts of climate change. The lack of political science expertise and research represents an obstacle for adapting to climate change, because adaptation is fundamentally political. Technical advances in adaptations for infrastructure, agriculture, public health, coastal protection, conservation, and other fields all depend on political variables for their implementation and effectiveness. For example, adaptation raises questions about political economy (adaptation costs money), political theory (adaptation involves questions of social justice), comparative politics (some countries more aggressively pursue adaptation), urban politics (some cities more aggressively pursue adaptation), regime type (democracies and authoritarian regimes may differently pursue adaptation), federalism (different levels of government may be involved), and several other fields of study including political conflict, international development, bureaucracy, migration, media, political parties, elections, civil society, and public opinion. I review the field of climate change adaptation and then explore the tremendous contributions that political scientists could make to adaptation research.
Temporal and Computerized Psycholinguistic Analysis of the Blog of a Chinese Adolescent Suicide
Authors: Li Tim M. H. , Chau Michael , Yip Paul S. F. , Wong Paul W. C.
Published: April 2014

Background: Text analysis of personal documents provides insight into the cognition of those who complete suicide. Many personal documents are digitalized and easily found on the Internet, which can be used to advance suicide research. Aims: (1) To examine the temporal relationships between posting intensity and language use to sketch the suicidal process of a young man on the basis of his blog entries. (2) To investigate whether digitalized personal documents and paper documents of suicide cases have similar or different language patterns. Method: Firstly, 193 blog entries of a 13-year-old boy posted during the year prior to his suicide were analyzed using the Chinese Linguistic Inquiry and Word Count (CLIWC) program. The temporal relationships between posting intensity and language use were illustrated by time series visualization. Secondly, the findings of this case study were compared with previous case studies from a systematic search of three Ovid databases. Results: Posting frequency and language use in the blog helped sketch the suicidal process of the young boy. In this case study, the ratio of positive to negative emotion words was associated with the posting trend. Progressive self-referencing appeared to be a primary predictive sign of suicide. However, the comparison did not show other clearly consistent patterns. Conclusion: Digitalized personal documents, when interpreted with other information of the individual, provide insight into the suicidal process of completed suicides. This study extends the findings of psycholinguistic analyses of suicides to the Chinese social context and online document form.
Critical behavior of a water monolayer under hydrophobic confinement
Authors: Bianco Valentino , Franzese Giancarlo
Published: April 2014

The properties of water can have a strong dependence on the confinement. Here, we consider a water monolayer nanoconfined between hydrophobic parallel walls under conditions that prevent its crystallization. We investigate, by simulations of a many-body coarse-grained water model, how the properties of the liquid are affected by the confinement. We show, by studying the response functions and the correlation length and by performing finite-size scaling of the appropriate order parameter, that at low temperature the monolayer undergoes a liquid-liquid phase transition ending in a critical point in the universality class of the two-dimensional (2D) Ising model. Surprisingly, by reducing the linear size L of the walls, keeping the walls separation h constant, we find a 2D-3D crossover for the universality class of the liquid-liquid critical point for "Equation missing", i.e. for a monolayer thickness that is small compared to its extension. This result is drastically different from what is reported for simple liquids, where the crossover occurs for "Equation missing" and is consistent with experimental results and atomistic simulations. We shed light on these findings showing that they are a consequence of the strong cooperativity and the low coordination number of the hydrogen bond network that characterizes water.
Towards a mathematical theory of meaningful communication
Authors: Corominas-Murtra Bernat , Fortuny Jordi , Solé Ricard V.
Published: April 2014

Meaning has been left outside most theoretical approaches to information in biology. Functional responses based on an appropriate interpretation of signals have been replaced by a probabilistic description of correlations between emitted and received symbols. This assumption leads to potential paradoxes, such as the presence of a maximum information associated to a channel that creates completely wrong interpretations of the signals. Game-theoretic models of language evolution and other studies considering embodied communicating agents show that the correct (meaningful) match resulting from agent-agent exchanges is always achieved and natural systems obviously solve the problem correctly. Inspired by the concept ofduality of the communicative signstated by the swiss linguist Ferdinand de Saussure, here we present a complete description of the minimal system necessary to measure the amount of information that is consistently decoded. Several consequences of our developments are investigated, such as the uselessness of a certain amount of information properly transmitted for communication among autonomous agents.
Determination of trace fungicides in environmental water samples using poly(HPMA-EDMA) monolith microextraction coupled to high performance liquid chromatography
Authors: Chen Mi , Zhang Miao , Wang Xiangfang , Peng Sha , Cheng Jing
Published: April 2014

A novel poly(2-hydroxypropyl methacrylate-ethylene dimethacrylate) (HPMA-EDMA) monolithic capillary column was synthesized and selected as the extraction medium for polymer monolith microextraction (PMME).
Stress in titania nanoparticles: an atomistic study
Authors: Darkins Robert , Sushko Maria L. , Liu Jun , Duffy Dorothy M.
Published: April 2014

The size-dependent surface and bulk stresses intrinsic to titania nanoparticles are investigated using atomistic simulation. Surface charge is also shown to induce a significant tensile stress.
Caterpillar locomotion-inspired valveless pneumatic micropump using a single teardrop-shaped elastomeric membrane
Authors: So Hongyun , Pisano Albert P. , Seo Young Ho
Published: April 2014

This paper presents a microfluidic pump operated by an asymmetrically deformed membrane, which was inspired by caterpillar locomotion.
Fabrication of highly electrically conducting fine patterns via substrate-independent inkjet printing of mussel-inspired organic nano-material
Authors: Ma Siyuan , Liu Liang , Bromberg Vadim , Singler Timothy J.
Published: April 2014

We report the inkjet printing of an aqueous suspension of synthesized mussel-inspired poly(dopamine) nanoparticles and the subsequent site-selective silver electroless plating process.
Synthesis and properties of air-stable n-channel semiconductors based on MEH-PPV derivatives containing benzo[c]cinnoline moieties
Authors: Chen Jyh-Chien , Wu Hsin-Chung , Chiang Chi-Jui , Chen Tuo , Xing Li
Published: April 2014

An OFET based on P50 exhibited air-stable n-channel behavior with an electron mobility of 7.8 × 10−3 cm2 V−1 s−1 under ambient conditions without annealing.
Substituent effect on the electroluminescence efficiency of amidinate-ligated bis(pyridylphenyl) iridium(iii) complexes
Authors: Rai Virendra Kumar , Nishiura Masayoshi , Takimoto Masanori , Hou Zhaomin
Published: April 2014

A significant substituent effect on the EL properties was observed and a heteroleptic iridium(iii) complex with a t-Bu substituted amidinate ligand [(ppy)2Ir{(t-BuN)2CPh}] showed high current and power efficiency.
Discrimination of Chinese patent medicines using near-infrared spectroscopy and principal component accumulation method
Authors: Shan Ruifeng , Mao Zhiyi , Yin Lihui , Cai Wensheng , Shao Xueguang
Published: April 2014

NIR spectroscopy combined with PCAcc was used to identify 12 classes of Chinese patent medicines.
Vortex-assisted emulsification microextraction followed by in-syringe ultrasound-assisted back-microextraction to determine haloacetic acids in waters
Authors: Rocío-Bautista Priscilla , Pino Verónica , Delgado Bárbara , Afonso Ana M. , Ayala Juan H.
Published: April 2014

We have evaluated a vortex-assisted emulsification microextraction procedure followed by in-syringe ultrasound-assisted back-microextraction for determining nine haloacetic acids in waters using HPLC-DAD.
Application of a non-aqueous capillary electrophoresis method to the analysis of triclosan in personal care products
Authors: Ma Hui , Wang Lijuan , Liu Huitao , Luan Feng , Gao Yuan
Published: April 2014

The application of a non-aqueous capillary electrophoresis method to the analysis of triclosan in personal care products.
Direct imaging of single gold nanoparticle etching: sensitive detection of lead ions
Authors: Dai Dinggui , Xu Dong , Cheng Xiaodong , He Yan
Published: April 2014

We present a highly sensitive Pb2+ detection method by in situ real-time imaging of Pb2+ catalyzed etching and size reduction of immobilized single gold nanoparticles with darkfield microscopy.
Li–Se battery: absence of lithium polyselenides in carbonate based electrolyte
Authors: Cui Yanjie , Abouimrane Ali , Sun Cheng-Jun , Ren Yang , Amine Khalil
Published: April 2014

The absence of lithium polyselenides in the Li–Se cell using carbonate based electrolyte prevents the occurrence of shuttle effect.
Optical reading of the open and closed states of a molecular turnstile
Authors: Zigon Nicolas , Larpent Patrick , Jouaiti Abdelaziz , Kyritsakas Nathalie , Hosseini Mir Wais
Published: April 2014

The reversible switching between the open and closed states of a molecular turnstile can be addressed by emission spectroscopy.
Conformational change and biocatalysis-triggered spectral shift of single Au nanoparticles
Authors: Zhao Yun , He Ya-Kai , Zhang Jing , Wang Feng-Bin , Wang Kang , Xia Xing-Hua
Published: April 2014

The conformational change of guanine-rich DNA and the biocatalytic process of DNAzyme are observed directly on single gold nanoparticles through NPPR spectra.
A preferable molecular crystal membrane for H2 gas separation
Authors: Takasaki Yuichi , Takamizawa Satoshi
Published: April 2014

A high H2 permeability (P), which does not obey the Knudsen diffusion law, was observed through a microporous single-crystal membrane.
Water-dispersible silicon dots as a peroxidase mimetic for the highly-sensitive colorimetric detection of glucose
Authors: Chen Qiong , Liu Meiling , Zhao Jiangna , Peng Xue , Chen Xiaojiao , Mi Naxiu , Yin Bangda , Li Haitao , Zhang Youyu , Yao Shouzhuo
Published: April 2014

We demonstrate that photoluminescent Si-dots exhibit an intrinsic peroxidase-like activity, and can catalyze the oxidization of 3,3′,5,5′-tetramethylbenzidine (TMB) by H2O2, and produce a color change.
Two 3D metal–organic frameworks of Cd(ii): modulation of structures and porous properties based on linker functionalities
Authors: Haldar Ritesh , Bonakala Satyanarayana , Kanoo Prakash , Balasubramanian Sundaram , Maji Tapas Kumar
Published: April 2014

Two Cd(ii) based 3D frameworks exhibit interesting structural features and adsorption properties based on the linker functionality modulation.
How to print a crystal structure model in 3D
Authors: Chen Teng-Hao , Lee Semin , Flood Amar H. , Miljanić Ognjen Š.
Published: April 2014

We present a simple procedure for the conversion of Crystallographic Information Files (CIFs) into Virtual Reality Modelling Language (VRML2, .wrl) files, which can be used as input files for three-dimensional (3D) printing.
Effect of post-synthesis hydrogen-treatment on the nature of iron species in Fe-BEA as NH3-SCR catalyst
Authors: Shwan Soran , Jansson Jonas , Olsson Louise , Skoglundh Magnus
Published: April 2014

The relative amount of monomeric iron species increases after post-synthesis treatment with hydrogen, which improves the low-temperature activity during NH3-SCR.
Biomimetic polyorganosiloxanes: model compounds for new materials
Authors: Kociok-Köhn Gabriele , Mahon Mary F. , Molloy Kieran C. , Price Gareth J. , Prior Timothy J. , Smith Douglas R. G.
Published: April 2014

Model organosilicon derivatives of DNA bases and polymeric analogues are reported with the crystallographically studied formation of hydrogen-bonded aggregates.
Bis(phosphinoselenoic amides) as versatile chelating ligands for alkaline earth metal (Mg, Ca, Sr and Ba) complexes: syntheses, structure and ε-caprolactone polymerisation
Authors: Kottalanka Ravi K. , Adimulam Harinath , Bhattacharjee Jayeeta , Vignesh Babu H. , Panda Tarun K.
Published: April 2014

A series of alkaline earth metal (Mg, Ca, Sr, Ba) complexes with the bis(phosphinoselenoic amine) ligand have been reported and the complexes are utilized as catalysts for the ROP of ε-caprolactone.
The interference standard method: evidence of principle, potentialities and limitations
Authors: Amais Renata S. , Nóbrega Joaquim A. , Donati George L.
Published: April 2014

High resolution sector field ICP-MS (SF-ICP-MS) is used to explore the mechanisms and limitations of the interference standard (IFS) method.
A full conformational characterization of antiandrogen cortexolone-17α-propionate and related compounds through theoretical calculations and nuclear magnetic resonance spectroscopy
Authors: Ferraboschi Patrizia , Legnani Laura , Celasco Giuseppe , Moro Luigi , Ragonesi Laura , Colombo Diego
Published: April 2014

Theoretical calculations and NMR analyses were used in order to conformationally characterize the topical androgen cortexolone-17α-propionate (red shading) in comparison with other steroidal androgens and antiandrogens.
Evaluation of photo-reactive siderophore producing bacteria before, during and after a bloom of the dinoflagellate Lingulodinium polyedrum
Authors: Yarimizu Kyoko , Polido Geraldine , Gärdes Astrid , Carter Melissa L. , Hilbern Mary , Carrano Carl J.
Published: April 2014

Evidence is increasing for a mutualistic relationship between phytoplankton and heterotrophic marine bacteria.
Zinc'ing sensibly: controlling zinc homeostasis at the transcriptional level
Authors: Choi Sangyong , Bird Amanda J.
Published: April 2014

Zinc-responsive transcription factors play a central role in zinc homeostasis by regulating zinc transporter and metallothionein gene expression.
Strategies for the construction of tetrahydropyran rings in the synthesis of natural products
Authors: Nasir Nadiah Mad , Ermanis Kristaps , Clarke Paul A.
Published: April 2014

This review focuses on the methodology used for the construction of tetrahydropyran (THP) rings in the synthesis of natural products over the last seven years.
Spectroscopic investigation of fluorinated phenols as pH-sensitive probes in mixed liposomal systems
Authors: Gasbarri Carla , Angelini Guido
Published: April 2014

The pKa values of three fluorinated phenols, 2,4,6-trifluorophenol (3FP), 2,3,5,6-tetrafluorophenol (4FP) and 2,3,4,5,6-pentafluorophenol (5FP) have been measured by using UV-vis and 19F-NMR spectroscopy at 25 °C in water and in the presence of pure POPC, pure DDAB and mixed POPC–DDAB liposomes.
NIS-mediated regioselective amidation of indole with quinazolinone and pyrimidone
Authors: Ghosh Suman Kr , Nagarajan Rajagopal
Published: April 2014

A mild, metal-free condition was developed for the direct regioselective C2 amidation of indoles and pyrroles with quinazolinone and pyrimidone derivatives in intermolecular fashion, which led to novel indolyl/pyrrolyl quinazolinone and pyrimidone derivatives in moderate to good yields.
Spin crossover iron(ii) complexes as PARACEST MRI thermometers
Authors: Jeon Ie-Rang , Park Jesse G. , Haney Chad R. , Harris T. David
Published: April 2014

We demonstrate the potential utility of spin crossover iron(ii) complexes as temperature-responsive paramagnetic chemical exchange saturation transfer (PARACEST) contrast agents in magnetic resonance imaging (MRI) thermometry.
A particle based model to simulate microscale morphological changes of plant tissues during drying
Authors: Karunasena H. C. P. , Senadeera W. , Brown R. J. , Gu Y. T.
Published: April 2014

SPH–DEM based microscale drying model can predict shrinkage and cell wall wrinkling of plant cells in tissues at different moisture contents and turgor pressures during drying (top row: full tissue view, bottom row: enlarged view).
Flexible freestanding sandwich-structured sulfur cathode with superior performance for lithium–sulfur batteries
Authors: Song Jiangxuan , Yu Zhaoxin , Xu Terrence , Chen Shuru , Sohn Hiesang , Regula Michael , Wang Donghai
Published: April 2014

Flexible freestanding sandwich-structured sulfur cathodes are developed for lithium–sulfur batteries, which exhibit excellent cycling stability and rate capability. A high areal capacity of ∼4 mA h cm−2 is also demonstrated based on this new cathode configuration.
Efficient synthesis of hierarchical NiO nanosheets for high-performance flexible all-solid-state supercapacitors
Authors: Qian Yue , Liu Rong , Wang Qiufan , Xu Jing , Chen Di , Shen Guozhen
Published: April 2014

A simple strategy was developed to grow NiO nanosheets on carbon cloth as a binder-free electrode for a high-performance flexible all-solid-state supercapacitor device.
Graphene nanosheets supporting Ru nanoparticles with controlled nanoarchitectures form a high-performance catalyst for COx-free hydrogen production from ammonia
Authors: Li Gang , Nagasawa Hiroki , Kanezashi Masakoto , Yoshioka Tomohisa , Tsuru Toshinori
Published: April 2014

Support-dependent and structure-sensitive Ru supported by graphene showed an easily controllable nanoarchitecture, yielding drastically improved catalytic performance for ammonia decomposition.
Temporal evolutions of the photoluminescence quantum yields of colloidal InP, InAs and their core/shell nanocrystals
Authors: Zhang Jianbing , Li Rong , Sun Weipeng , Wang Qi , Miao Xiangshui , Zhang Daoli
Published: April 2014

Surface oxidation substantially affects the optical properties of nanocrystals. Primary oxidation eliminates the surface dangling bonds and leads to PL enhancement, while it does not affect the nanocrystal size. However, further surface oxidation results in reduction of PL.
Optimal diversity multiplexing tradeoff for opportunistic relaying coded cooperation protocols with quantised channel state information feedback
Authors: Haghighi Ali Asghar
Published: April 2014

A cooperative multiple relay system is considered in this study which exploit opportunistic relaying (OR)‐based protocol with coded cooperation approach. For the considered system, the optimal diversity multiplexing tradeoff (DMT) is determined in different scenarios including either considering the source node as a potential relay or not. The study is then extended to the case where the quantised channel state information (QCSI) feedback is considered. In particular, an OR‐based protocol with QCSI at the source node is presented. It is shown that the QCSI feedback linearly improves the DMT performance. In addition, it is proved that the role of QCSI feedback to improve DMT performance is higher than that of cooperative relays.
Extended low‐density parity‐check codes for feedback‐based cooperative diversity schemes
Authors: Ali Hussain , Kousa Maan
Published: April 2014

Cooperative diversity or user cooperation achieves the diversity gain without adding physical antennas to the users or mobile stations. The users work in a cooperative fashion by using their single antennas to create a virtual transmit diversity, called relay diversity or cooperative diversity. The diversity gain achieved by cooperative diversity can be further improved using error correction codes. Low‐density parity‐check (LDPC) codes are linear block codes with good error correction capabilities. The authors present a novel approach using extended LDPC codes to increase the diversity gain in cooperative diversity. The authors also compare the extended LDPC codes with the punctured LDPC codes in a cooperative diversity and show that there is a performance–complexity tradeoff between the punctured and the extended LDPC codes in the cooperative diversity. Furthermore, the authors will propose two feedback‐based protocols for cooperative diversity and compare their throughput with non‐feedback‐based cooperative diversity using extended LDPC codes.
Performance analysis of asynchronous optical code division multiple access with spectral‐amplitude‐coding
Authors: Sedaghat Mohammad Ali , Müller Ralf R. , Marvasti Farokh
Published: April 2014

In this study, the performance of a spectral‐amplitude‐coding optical code division multiple access (SAC‐OCDMA) system in the asynchronous regime is evaluated using a Gaussian approximation of the decision variable for codes with fixed cross‐correlation used in SAC‐OCDMA systems. The authors consider the effect of phase‐induced intensity noise (PIIN), thermal noise and shot noise. Moreover, the validity of the Gaussian approximation is confirmed by a Kolmogorov–Smirnov fitness test. For sake of comparison, the bit error rate (BER) of the asynchronous SAC‐OCDMA system is also plotted numerically in comparison with the BER of the synchronous SAC‐OCDMA. They show that a SAC‐OCDMA system without any time management for the users, that is, the asynchronous regime, has a better performance than the synchronous SAC‐OCDMA when PIIN effect exists.
Performance analysis of V‐BLAST reception under multiuser decode‐and‐forward cooperation
Authors: Miridakis Nikolaos I.
Published: April 2014

The performance of a dual‐hop system is studied and evaluated, where m single‐antenna source nodes communicate with a destination equipped with n ≥ m antennas via m single‐antenna relays. The decode‐and‐forward protocol is implemented at the relays whereas the classical ordered V‐BLAST scheme is performed at the destination. The analysis involves spatially independent non‐identically distributed Rayleigh channel fading channels, reflecting on distinct average received powers among the different source and/or relay nodes with the destination, suitable for practical applications. The identically distributed scenario is also included as a special case. Novel union closed‐form system bound expressions are derived in terms of the outage probability and the average symbol error probability. These bounds correspond to the cases of both the perfect and the imperfect channel state information at the relay and the destination nodes. The numerical results, accompanied with the equivalent simulation ones, reveal the accuracy of the proposed approach.
Power allocation for orthogonal frequency division multiplexing‐based cognitive radio networks with cooperative relays
Authors: Du Sidan , Huang Fangjiang , Wang Shaowei
Published: April 2014

The power allocation problem in orthogonal frequency division multiplexing‐based cognitive radio (CR) networks with cooperative relays has been investigated here, where both the interference to primary users (PUs) and the power budget of the CR network are considered. The authors try to maximise the overall throughput of the CR network within the given constraints. The coupling variables in the formulated problem make it hard to solve, so an iterative optimisation scheme to find out the optimal solution with a controllable complexity is developed. First, the original problem is decomposed into two subproblems that can be solved independently. A fast barrier method has been employed to work out the optimal solution to one of the subproblems with a complexity of O(L2N), where L and N are the number of PUs and subcarriers, respectively. Then, an iterative procedure is developed to solve the other subproblem. Numerical results show that the proposed method can significantly increase the throughput of the CR system, comparing with other representative ones. Furthermore, the proposed algorithm gives a general power optimisation framework for CR networks with cooperative relays.
Distributed allocation of subcarrier, power and bit‐level in multicell orthogonal frequency‐division multiple‐access networks
Authors: Fathi Mohammad , Karipidis Eleftherios
Published: April 2014

The downlink of multicell orthogonal frequency‐division multiple‐access (OFDMA) networks is studied, and the adaptive allocation of spectrum, power and rate is addressed. The authors consider networks with adaptive frequency reuse and discrete‐level rates. Initially, the joint allocation problem is formulated as a centralised non‐linear mixed‐integer program (MIP), which is computationally intractable to solve optimally for practical problem sizes. Then, the capability of the receivers is exploited to estimate the subcarrier channel gains and the joint allocation problem is accordingly decomposed into subproblems, each of which is solved by a different base station with linear complexity. In the proposed iterative algorithm, the base stations perform rate and receiver allocation per subcarrier, with concurrent iterations. A filtering method is introduced to further decrease the algorithm complexity. Furthermore, for benchmarking purposes, the authors transform the original non‐linear MIP to a linear MIP and find the optimal solution by means of standard branch‐and‐cut solvers. The merit of the proposed algorithm is demonstrated with numerical comparisons of its performance against the solutions of the linear MIP and the iterative waterfilling algorithm.
Probabilistic relay assignment strategy for cooperation networks with random relays
Authors: Azari M. Mahdi , Rabiei Amir Masoud , Behnad Aydin
Published: April 2014

A new approach in fairness is proposed by using a probabilistic relay assignment strategy for cooperative communication systems. In this approach, relays are allocated to sources based on a probabilistic relay assignment function, which is characterised by the outage probability. To examine the proposed relay assignment strategy, an exact expression for the outage probability of an opportunistic coded cooperation diversity system is derived. It is assumed that the relays in this system are distributed according to a two‐dimensional homogeneous Poisson point process, and the transmission channels undergo Rayleigh fading as well as path loss. It is observed that the proposed strategy reduces the number of requests for using the relays and, thus, utilises the relays more efficiently. Furthermore, compared to the conventional opportunistic relay assignment strategy, the total power consumed by the relays decreases, while the quality of service requirements are still satisfied.
Adaptive user selection of opportunistic multicast scheduling in wireless networks
Authors: Li Mingming , Wang Xiaoxiang , Zhou Jia , Qu Jing
Published: April 2014

In this study, an adaptive user selection of opportunistic multicast scheduling system (OMS‐AUS) scheme is proposed to improve the system throughput performance of opportunistic multicast scheduling system. Different from the previous literatures, the user selection ratio would no longer be a constant, but would vary as the number of users that have not received multicast bits changes, which can exploit the system transmission ability better. The objective is to obtain the optimal values of user selection fractions. (i) For the case without instantaneous channel state information (CSI), a channel gain distribution‐based OMS‐AUS is proposed. Firstly, a system throughput matrix (STM) is formulated to imitate the user grouping process. Secondly, the value of each element in STM is derived according to the channel gain distribution. Finally, by fully searching the elements in STM, the optimal solution is obtained. To reduce the computational complexity, a suboptimal heuristic searching scheme is also proposed. (ii) For the case with instantaneous CSI, an improved approach based on both the channel gain distribution and instantaneous CSIs is proposed. Simulation results show that both of the two proposed approaches can obtain better performance compared to the existing schemes.
Uplink scheduling solution for enhancing throughput and fairness in relayed long‐term evolution networks
Authors: Ruby Rukhsana , Leung Victor C.M.
Published: April 2014

Relaying is one of the key techniques adopted by third‐generation partnership project long‐term evolution (LTE) advanced as part of 4G cellular technologies, aiming to increase coverage and capacity of networks especially for the edge nodes. The authors have considered the uplink scheduling of LTE networks with the help of positioned relay nodes which have fixed routing configuration. The entire problem is projected as a constrained convex optimisation formulation and for the solution purpose, subgradient method is adopted. Revealing the guiding principles of optimal solution, a few suboptimal scheduling algorithms are proposed to allocate resource blocks across all nodes with the help of existing work. Deploying a large number of relays may not be useful to basic user nodes, and hence, the proposed schemes are adaptive and have ability to distinguish useful relays from not‐useful ones. In addition to system throughput maximisation, for ensuring fairness across user nodes, the authors have proposed scheduling techniques which are the outcome of Nash bargaining solution. Numerical calculations and results have been shown to justify that relay nodes can potentially improve system's performance at low load, whereas at high load they remain inactive because of their inability to contribute.
Packet error rate‐based adaptive rate optimisation with selective‐repeat automatic repeat request for convolutionally‐coded M‐ary quadrature amplitude modulation systems
Authors: Hwang Ji Won , Shikh‐Bahaei Mohammad
Published: April 2014

Link adaptation using adaptive modulation and coding (AMC) is a popular physical layer technique for efficient use of time‐varying fading channels. Using a cross‐layer approach, AMC and truncated automatic repeat request scheme at data link layer are jointly considered. For a convolutionally‐coded M‐ary quadrature amplitude modulation system under block fading channel condition, a variable rate transmission scheme that uses imperfect channel state information is derived. First, a closed‐form expression for approximating packet error rate (PER) is found as a function of coded information rate. It is then shown that by solving an optimisation problem using this expression, optimum transmission rate can be determined in a way that maximises the spectral efficiency while satisfying an average PER constraint. Hence, the parameters in physical and medium access control layers are incorporated in the analysis.