bluuebunny/crossref_metadata_2025 huggingface dataset:
Associations of lifetime traumatic experience with dysfunctional eating patterns and postsurgery weight loss in adults with obesity: A retrospective study
Authors: Ruffault Alexis , Vaugeois Fanny , Barsamian Charles , Lurbe i Puerto Kàtia , Le Quentrec‐Creven Gérane , Flahault Cécile , Naudé Anne‐Jeanne , Ferrand Margot , Rives‐Lange Claire , Czernichow Sébastien , Carette Claire
Published: March 2018

This study aimed to examine the associations of lifetime traumatic experience with presurgery and postsurgery eating pathology and postoperative weight loss in a sample of adult bariatric surgery patients using electronic medical record (EMR) data. Presurgery lifetime exposure to traumatic event, presurgery and postsurgery dysfunctional eating patterns, and post‐operative total and excess weight losses were extracted from electronic medical records of 200 adult bariatric surgery patients in 2013 and 2014. Logistic regression analyses were conducted. During their lifetime, 60.5% of the patients (81.5% women, age = 44.4 ± 11.5 years; BMIpre = 44.9 ± 5.5 kg/m2) reported that they were exposed to a traumatic event. Before surgery, trauma exposure was associated with impulsive, compulsive, or restrictive eating patterns (OR = 2.40), overeating or disturbed eating (OR = 1.55), and grazing or night eating behaviours (OR = 1.72). After surgery, trauma exposure was associated with lower total weight loss at 6 (OR = 2.06) and 24 months (OR = 2.06), and to overeating or disturbed eating (OR = 1.53) 12 months after surgery. Bariatric surgery candidates with a history of trauma exposure could benefit from closer medical, dietetic, and/or psychological follow‐up care to avoid insufficient postoperative weight loss as well as reappearance of dysfunctional eating patterns after surgery.
Semitransparent CH3NH3PbI3 Films Achieved by Solvent Engineering for Annealing‐ and Electron Transport Layer‐Free Planar Perovskite Solar Cells
Authors: Wei Xiangfeng , Zhang Mengmeng , Liu Xiaoqian , Chen Fang , Lei Xunyong , Liu Han , Meng Fancheng , Zeng Hualing , Yang Shangfeng , Liu Jiehua
Published: March 2018

A new solvent engineering method by using toluene as an antisolvent is developed to construct dense, mirror‐like, void‐free, and semitransparent CH3NH3PbI3 (MAPbI3) perovskite films, and the corresponding planar heterojunction perovskite solar cells (PSCs) exhibit a power conversion efficiency (PCE) of 16.1%. Upon removing the commonly used TiO2 electron transport layer (ETL), a PCE of 12.6% is attained for such an ETL‐free PSC device, suggesting the superior electron self‐extraction ability of MAPbI3 perovskite film fabricated via our approach. Moreover, we further simplified the device fabrication process by removing the thermal post‐annealing step, which is generally required for conventional one‐step or two‐step solution methods used for preparing perovskite films, and achieved a PCE of 13.0 and 10.5% for the PSCs with ETL and without ETL, respectively. Thus, the mirror‐like and semitransparent MAPbI3 perovskite films prepared via our approach can be prepared without thermal annealing process, and this provides a new strategy for solar cells based on non‐FTO substrates and with tandem structures.
On the Agile Literature Review Approach for Practising Managers: A Proposal
Authors: Ho Joseph Kim‐Keung
Published: March 2018

Literature review skill as covered in the subject of Research Methods is not only useful for doing dissertation projects in academic programme study but also valuable for informing practising managers to cope with actual workplace management issues and concerns. To make literature review easier for practising managers to carry out, the writer proposes the agile literature review approach (ALRA), primarily for applied business research and practices. The main ALRA aim is to promote a complicated understanding of a management topic and its associated management concern by the ALRA user. Although the agile approach is lightweight, its effective application requires endorsement of contemporary systems thinking; this thinking is theoretically profound, thus requiring long‐term engaging intellectual learning to master. Copyright © 2018 John Wiley & Sons, Ltd.
Random or evolutionary search for object‐oriented test suite generation?
Authors: Shamshiri Sina , Rojas José Miguel , Gazzola Luca , Fraser Gordon , McMinn Phil , Mariani Leonardo , Arcuri Andrea
Published: March 2018

An important aim in software testing is constructing a test suite with high structural code coverage, that is, ensuring that most if not all of the code under test have been executed by the test cases comprising the test suite. Several search‐based techniques have proved successful at automatically generating tests that achieve high coverage. However, despite the well‐established arguments behind using evolutionary search algorithms (eg, genetic algorithms) in preference to random search, it remains an open question whether the benefits can actually be observed in practice when generating unit test suites for object‐oriented classes. In this paper, we report an empirical study on the effects of using evolutionary algorithms (including a genetic algorithm and chemical reaction optimization) to generate test suites, compared with generating test suites incrementally with random search. We apply the EVOSUITEunit test suite generator to 1000 classes randomly selected from the SF110 corpus of open‐source projects. Surprisingly, the results show that the difference is much smaller than one might expect: While evolutionary search covers more branches of the type where standard fitness functions provide guidance, we observed that, in practice, the vast majority of branches do not provide any guidance to the search. These results suggest that, although evolutionary algorithms are more effective at covering complex branches, a random search may suffice to achieve high coverage of most object‐oriented classes.
The effect of design drift limit on the seismic performance of RC dual high‐rise buildings
Authors: Zaker Esteghamati Mohsen , Banazadeh Mehdi , Huang Qindan
Published: March 2018

Current building codes aim to ensure the acceptable performance of structures implicitly. Because these provisions are empirically developed for low‐ to medium‐rise buildings, their applicability to high‐rise building warrants further investigation. In this paper, the effect of design drift limit on the seismic performance of reinforced concrete dual high‐rise buildings is considered. Nine buildings are designed for 3 drift limits: the code limit (i.e., 2%), one that is lower than the code limit (i.e., 1.5%), and one that is higher than the code limit (i.e., 3%). For each drift limit, buildings of 3 heights (20, 25, and 30 stories) are designed. Finite element models are constructed in OpenSees, and incremental dynamic analysis is performed. The results are used to develop probabilistic seismic demand models, where model parameters are determined using maximum likelihood estimation to incorporate equality and censored data. Reliability analysis using probabilistic demand models is conducted to derive seismic fragility and demand hazard curves. In addition, the collapse performance of the drift limits is evaluated using the Federal Emergency Management Agency (FEMA) P695 procedure. The study results show that the design drift limit affects the building's seismic performance, and the effect depends on the performance level considered. Moreover, from a structural integrity perspective, a larger design drift limit does not induce a significantly higher risk and might yield a more cost‐effective design.
Approximate method of estimating seismic performance of high‐rise buildings with oil‐dampers
Authors: Takabatake Hideo , Kitada Yukihiko
Published: March 2018

When subjected to long‐period ground motions, many existing high‐rise buildings constructed on plains with soft, deep sediment layers experience severe lateral deflection, caused by the resonance between the long‐period natural frequency of the building and the long‐period ground motions, even if they are far from the epicenter. This was the case for a number of buildings in Tokyo, Nagoya, and Osaka affected by the ground motions produced by the 2011 off the Pacific coast of Tohoku earthquake in Japan. Oil‐dampers are commonly used to improve the seismic performance of existing high‐rise buildings subjected to long‐period ground motion. This paper proposes a simple but accurate analytical method of predicting the seismic performance of high‐rise buildings retrofitted with oil‐dampers installed inside and/or outside of the frames. The method extends the authors' previous one‐dimensional theory to a more general method that is applicable to buildings with internal and external oil‐dampers installed in an arbitrary story. The accuracy of the proposed method is demonstrated through numerical calculations using a model of a high‐rise building with and without internal and external oil‐dampers. The proposed method is effective in the preliminary stages of improving the seismic performance of high‐rise buildings.
Seismic performance of reinforced concrete columns confined with two layers of stirrups
Authors: Li Wei , Sun Linzhu , Zhao Junliang , Lu Pengfei , Yang Fang
Published: March 2018

This paper presents an experimental study on seismic behavior of reinforced concrete columns confined with 2 layers of stirrups. Six specimens, namely, 3 square‐section columns and 3 circular‐section columns, were manufactured using 2 layers of high‐strength stirrups. They were tested under cyclic lateral loading. The main parameters under investigation were the cross‐section type and stirrup spacing. The seismic behavior of the test specimens was analyzed in terms of various factors: load–displacement relationship, strength and stiffness degradation, ductility, and dissipated energy. The test results indicate that in general, all tested specimens exhibited very ductile behavior and dissipated energy. They presented a flexural failure mode, and the strength and stiffness degradation of the postelastic stage was not obvious. The results also indicate that a DCS square‐section column exhibited lower lateral displacement capacity than that of a companion DCC circular‐section column with the same stirrup spacing. Furthermore, on the basis of principles of equilibrium and compatibility of strains as well as ACI code, we developed equations to estimate the seismic bending moment capacity, accounting for the confinement effect of 2 layers of high‐strength stirrups. The calculated solutions were then compared with the test results, and the relationships were observed with reasonable accuracy for engineering applications.
Mechanisms of Wnt signaling and control
Authors: Grainger Stephanie , Willert Karl
Published: March 2018

The Wnt signaling pathway is a highly conserved system that regulates complex biological processes across all metazoan species. At the cellular level, secreted Wnt proteins serve to break symmetry and provide cells with positional information that is critical to the patterning of the entire body plan. At the organismal level, Wnt signals are employed to orchestrate fundamental developmental processes, including the specification of the anterior–posterior body axis, induction of the primitive streak and ensuing gastrulation movements, and the generation of cell and tissue diversity. Wnt functions extend into adulthood where they regulate stem cell behavior, tissue homeostasis, and damage repair. Disruption of Wnt signaling activity during embryonic development or in adults results in a spectrum of abnormalities and diseases, including cancer. The molecular mechanisms that underlie the myriad of Wnt‐regulated biological effects have been the subject of intense research for over three decades. This review is intended to summarize our current understanding of how Wnt signals are generated and interpreted.

This article is categorized under:

Biological Mechanisms > Cell Signaling

Developmental Biology > Stem Cell Biology and Regeneration
Clinical feasibility of a new full-thickness endoscopic plication device (GERDx™) for patients with GERD: results of a prospective trial
Authors: Weitzendorfer Michael , Spaun Georg O. , Antoniou Stavros A. , Witzel Kai , Emmanuel Klaus , Koch Oliver O.
Published: March 2018

Background

Previous studies suggest clinical effectiveness of endoscopic full-thickness plication in selected patients with gastroesophageal reflux disease (GERD). The aim of this study was to assess the clinical safety and efficiency of the GERDx™ device by evaluating clinical parameters, reflux symptom scores, and quality of life (QoL).

Methods

Prospective one-arm trial evaluating the outcome of forty patients with GERD subjected to endoscopic plication with the GERDx™ device. We included patients with at least one typical reflux symptom despite treatment with a PPI for > 6 months, pathologic esophageal acid exposure, hiatal hernia of size < 2 cm, and endoscopic Hill grade II–III. Evaluation of Gastrointestinal Quality of Life Index (GIQLI), symptom scores, esophageal manometry, and impedance-pH-monitoring were performed at baseline and at 3 months after surgery. (Trial Registration: ClinicalTrials.gov NCT 01798212.)

Results

There were no intraoperative complications. Four out of forty patients experienced postoperative complications requiring intervention. Seven of forty patients were subjected to laparoscopic fundoplication 3 months after endoscopic plication due to persistent symptoms and were lost to further follow-up. Thirty out of forty patients were available at 3-month follow-up. There was an improvement of the GIQLI score, from a mean of 92.45 ± 18.47 to 112.03 ± 13.11 (p < 0.001). The general reflux-specific score increased from a mean of 49.84 ± 24.83 to 23.93 ± 15.63 (p < 0.001), and the DeMeester score from a mean of 46.48 ± 30.83 to 20.03 ± 23.62 (p < 0.001). There was no significant change in manometric data after intervention. Three of thirty patients continued daily antireflux medication.

Conclusions

Endoscopic plication with the GERDx™ device reduced distal acid exposure of the esophagus, reflux-related symptoms, and improved GIQLI scores with minimal side effects in a selected cohort of patients and may be a safe alternative in the treatment of GERD.
Ultramafic vegetation and soils in the circumboreal region of the Northern Hemisphere
Authors: Teptina Anzhelika , Paukov Alexander , Rajakaruna Nishanta
Published: March 2018

The paper summarizes literature on climate, soil chemistry, vegetation and metal accumulation by plants found on ultramafic substrata in the circumboreal zone (sensu Takhtajan, Floristic regions of the world, 1986) of the Northern Hemisphere. We present a list of 50 endemic species and 18 ecotypes obligate to ultramafic soils from the circumboreal region of Holarctic, as well as 30 and 2 species of Ni and Zn hyperaccumulators, respectively. The number of both endemics and hyperaccumulators are markedly lower compared to that of the Mediterranean and tropical regions. The diversity of plant communities on ultramafics soils of the circumboral region is also described. The underlying causes for the differences of ultramafic flora between arctic, cold, cool temperate and Mediterranean and tropical regions are also discussed.
Relationship between the Ni hyperaccumulator Alyssum murale and the parasitic plant Orobanche nowackiana from serpentines in Albania
Authors: Bani Aida , Pavlova Dolja , Benizri Emile , Shallari Seit , Miho Liri , Meco Marjol , Shahu Edmira , Reeves Roger , Echevarria Guillaume
Published: March 2018

Orobanche nowackiana Markgr. is the only parasitic flowering plant in Europe which is an obligate serpentinophyte. This plant parasitizes the Ni hyperaccumulator Alyssum murale Waldst. & Kit. which grows in many areas including serpentine slopes of Mt. Komjan (Albania). The aims of the study were to investigate this host/parasite relationship from a biogeochemical point of view in order to evaluate: (1) the metal accumulation in different parts of the parasite and host plants and (2) the effect of Orobanche infection on host growth. Soil and plant samples of A. murale and O. nowackiana were analyzed for elemental concentrations after acid digestion using inductively coupled plasma atomic emission spectrometry (Ca, Mg, Fe, Ni, Cr, Co, Zn, Cu, Mn, Na, Al), colorimetry (for N and P), and flame photometry (for K). Individuals of A. murale, both infected and healthy, showed slight differences in their composition of essential elements (N, P, K) and of some micronutrients. The parasite had higher P, K, Na, and lower N, Ca, Mg, Ni, Zn, Co, Mn and Al concentrations than the host. Orobanche nowackiana is a Ni accumulator with 299 mg kg−1 in the leaves. Hyperaccumulation of Ni by A. murale did not prevent attack by O. nowackiana. After infection there was a decline in Ni concentration and the dry weight of all organs of the host, thus reducing the biomass yield and consequently Ni phytoextraction yield of A. murale. This infection could be a potential threat to the use of A. murale for Ni agromining.
Self-governing prisons: Prison gangs in an international perspective
Authors: Butler Michelle , Slade Gavin , Dias Camila Nunes
Published: March 2018

This paper finds qualified support for the use of Skarbek’s (2011, 2014) governance theory to understand the emergence of prison gang-like groups in Kyrgyzstan, Northern Ireland and Brazil. However, Skarbek’s (2011, 2014) governance theory has little to say about how many prison gangs emerge and how they organise comparatively outside the US context. This paper argues that variation in the number of gangs and their monopolization of informal governance can only be explained by considering importation and deprivation theories alongside governance theories. These theories factor in variation in prison environments and pre-existing societal divisions imported into prison, which affect the costs on information transmission and incentives for gang expansion. In particular, the paper pays attention to the wider role social and political processes play in influencing whether monopoly power by prison gangs is supported and legitimized or not.
Imaging correlations of tau, amyloid, metabolism, and atrophy in typical and atypical Alzheimer's disease
Authors: Whitwell Jennifer L. , Graff‐Radford Jonathan , Tosakulwong Nirubol , Weigand Stephen D. , Machulda Mary M. , Senjem Matthew L. , Spychalla Anthony J. , Vemuri Prashanthi , Jones David T. , Drubach Daniel A. , Knopman David S. , Boeve Bradley F. , Ertekin‐Taner Nilüfer , Petersen Ronald C. , Lowe Val J. , Jack Clifford R. , Josephs Keith A.
Published: March 2018

Introduction

Neuroimaging modalities can measure different aspects of the disease process in Alzheimer's disease, although the relationship between these modalities is unclear.

Methods

We assessed subject‐level regional correlations between tau on [18F]AV‐1451 positron emission tomography (PET), β amyloid on Pittsburgh compound B PET, hypometabolism on [18F] fluorodeoxyglucose PET, and cortical thickness on magnetic resonance imaging in 96 participants with typical and atypical Alzheimer's disease presentations. We also assessed how correlations between modalities varied according to age, presenting syndrome, tau‐PET severity, and asymmetry.

Results

[18F]AV‐1451 uptake showed the strongest regional correlation with hypometabolism. Correlations between [18F]AV‐1451 uptake and both hypometabolism and cortical thickness were stronger in participants with greater cortical tau severity. In addition, age, tau asymmetry, and clinical diagnosis influenced the strength of the correlation between [18F]AV‐1451 uptake and cortical thickness.

Discussion

These findings support a close relationship between tau and hypometabolism in Alzheimer's disease but show that correlations between neuroimaging modalities vary across participants.
Gender Dysphoria and Gender Change in Disorders of Sex Development/Intersex Conditions: Results From the dsd-LIFE Study
Authors: Kreukels Baudewijntje P.C. , Köhler Birgit , Nordenström Anna , Roehle Robert , Thyen Ute , Bouvattier Claire , de Vries Annelou L.C. , Cohen-Kettenis Peggy T. ,   on behalf of the dsd-LIFE group
Published: March 2018

Background

Information on the psychosexual outcome of individuals with disorders of sex development (DSDs) and intersex conditions is of great importance for sex assignment at birth of newborns with DSD.

Aim

To assess gender change and gender dysphoria in a large sample of individuals with different DSDs.

Methods

A cross-sectional study was conducted in 14 European centers with 1,040 participants (717 female-identifying and 311 male-identifying persons and 12 persons identifying with another gender) with different forms of DSD. The cohort (mean age = 32.36 years, SD = 13.57) was divided into 6 major subgroups: women with 45,X DSD and variants (Turner syndrome; n = 325), men with 47,XXY DSD and variants (Klinefelter syndrome; n = 219), women with XY DSD without androgen effects (n = 107) and with androgen effects (n = 63), men with XY DSD (n = 87), and women with 46,XX congenital adrenal hyperplasia (n = 221). Data on psychosexual outcome were gathered by medical interviews and questionnaires.

Outcomes

Gender change and gender dysphoria.

Results

Although gender changes were reported by 5% of participants, only in 1% (3% if those with Klinefelter and Turner syndromes—conditions in which gender issues are not prominent—are excluded) did the gender change take place after puberty and was likely initiated by the patient. 39 participants (4%) reported gender variance: between male and female, a gender other than male or female, or gender queer, alternating gender roles, or a gender expression that differed from the reported gender. This group had lower self-esteem and more anxiety and depression than the other participants.

Clinical Implications

Clinicians should be aware of and sensitive to the possibility that their patients with DSD not only might have transgender feelings and a desire to change gender, but also identify as different from male or female. The complexity of their feelings might require counseling for some patients.

Strengths and Limitations

The study is unique in the large number of participants from many different clinics, with sizable numbers in most subgroups, and in the large number of aspects that were measured. However, the very broadness of the study made it impossible to focus in detail on gender issues. Also, there is a need for instruments specifically measuring gender dysphoria in individuals with DSD that take non-binary genders into account.

Conclusion

To make appropriate gender care possible for people with DSD, the gender-normative and gender-variant development of children with DSD should be studied in longitudinal studies.
S-Nitrosoglutathione Reductase (GSNOR) Deficiency Results in Secondary Hypogonadism
Authors: Masterson Thomas A. , Arora Himanshu , Kulandavelu Shathiyah , Carroll Rona S. , Kaiser Ursula B. , Gultekin Sakir H. , Hare Joshua M. , Ramasamy Ranjith
Published: March 2018

Background

Excess reactive oxygen species and reactive nitrogen species are implicated in male infertility and impaired spermatogenesis.

Aim

To investigate the effect of excess reactive nitrogen species and nitrosative stress on testicular function and the hypothalamic-pituitary-gonadal axis using the S-nitrosoglutathione reductase-null (Gsnor−/−) mouse model.

Methods

Testis size, pup number, and epididymal sperm concentration and motility of Gsnor−/− mice were compared with those of age-matched wild-type (WT) mice. Reproductive hormones testosterone (T), luteinizing hormone (LH), and follicle-stimulating hormone were compared in Gsnor−/− and WT mice. Immunofluorescence for Gsnor−/− and WT testis was performed for 3β-hydroxysteroid dehydrogenase and luteinizing hormone receptor (LHR) and compared. Human chorionic gonadotropin and gonadotropin-releasing hormone stimulation tests were performed to assess and compare testicular and pituitary functions of Gsnor−/− and WT mice.

Outcomes

Evaluation of fertility and reproductive hormones in Gsnor−/− vs WT mice. Response of Gsnor−/− and WT mice to human chorionic gonadotropin and gonadotropin-releasing hormone to evaluate LH and T production.

Results

Gsnor −/− mice had smaller litters (4.2 vs 8.0 pups per litter; P < .01), smaller testes (0.08 vs 0.09 g; P < .01), and decreased epididymal sperm concentration (69 vs 98 × 106; P < .05) and motility (39% vs 65%; P < .05) compared with WT mice. Serum T (44.8 vs 292.2 ng/dL; P < .05) and LH (0.03 vs 0.74 ng/mL; P = .04) were lower in Gsnor−/− than in WT mice despite similar follicle-stimulating hormone levels (63.98 vs 77.93 ng/mL; P = .20). Immunofluorescence of Gsnor−/− and WT testes showed similar staining of 3β-hydroxysteroid dehydrogenase and LHR. Human chorionic gonadotropin stimulation of Gsnor−/− mice increased serum T (>1,680 vs >1,680 ng/dL) and gonadotropin-releasing hormone stimulation increased serum LH (6.3 vs 8.9 ng/mL; P = .20) similar to WT mice.

Clinical Translation

These findings provide novel insight to a possible mechanism of secondary hypogonadism from increased reactive nitrogen species and excess nitrosative stress.

Strengths and Limitations

Limitations of this study are its small samples and variability in hormone levels.

Conclusion

Deficiency of S-nitrosoglutathione reductase results in secondary hypogonadism, suggesting that excess nitrosative stress can affect LH production from the pituitary gland.
Two-Career Chaos: A Look in the Rearview Mirror
Authors: Tauxe Lisa
Published: March 2018

Can we really have it all? A scientist reflects on the gut-wrenching choices of juggling marriage, kids, and careers.
Correction: Author Correction: The scaffold protein p140Cap limits ERBB2-mediated breast cancer progression interfering with Rac GTPase-controlled circuitries
Authors: Grasso Silvia , Chapelle Jennifer , Salemme Vincenzo , Aramu Simona , Russo Isabella , Vitale Nicoletta , di Cantogno Ludovica Verdun , Dallaglio Katiuscia , Castellano Isabella , Amici Augusto , Centonze Giorgia , Sharma Nanaocha , Lunardi Serena , Cabodi Sara , Cavallo Federica , Lamolinara Alessia , Stramucci Lorenzo , Moiso Enrico , Provero Paolo , Albini Adriana , Sapino Anna , Staaf Johan , Di Fiore Pier Paolo , Bertalot Giovanni , Pece Salvatore , Tosoni Daniela , Confalonieri Stefano , Iezzi Manuela , Di Stefano Paola , Turco Emilia , Defilippi Paola
Published: March 2018

Nature Communications 8: Article number: 14797 (2017); Published online 16 March 2017; Updated 30 March 2018 In the original version of this Article, the affiliation details for Anna Sapino were incorrectly given as Department of Medical Sciences, University of Torino, 10126 Torino, Italy instead ofCandiolo Cancer Institute-FPO, IRCCS, Str.
Effects of accelerated degradation on metal supported thin film-based solid oxide fuel cells
Authors: Reolon R. P. , Sanna S. , Xu Y. , Lee I. , Bergmann C. P. , Pryds N. , Esposito V.
Published: March 2018

Elemental distribution effects are detected throughout the metal supported TF-SOFC, indicating low energy surface elemental interdiffusion and electromigration effects.
Eosin Y–Yb(OTf)3 catalyzed visible light mediated electrocyclization/indole ring opening towards the synthesis of heterobiaryl-pyrazolo[3,4-b]pyridines
Authors: Singh Shikha , Chauhan Parul , Ravi Makthala , Yadav Prem P.
Published: March 2018

Synthesis of heterobiaryl-pyrazolo[3,4-b]pyridines via Lewis acid and visible light photo-catalysis at room temperature.
NiCo2O4 nanoframes with a nanosheet surface as efficient electrocatalysts for the oxygen evolution reaction
Authors: Chen Zhen , Zhao Bo , He Ya-Chuan , Wen Hao-Ran , Fu Xian-Zhu , Sun Rong , Wong Ching-Ping
Published: March 2018

NiCo2O4 nanoframes with a nanosheet surface demonstrate excellent electrocatalytic performance for the oxygen evolution reaction.
Directing group assisted ZnI2-catalyzed cyclopropanation of indoles via 2-furylcarbenoids
Authors: Chen Wei , Ji Dong-Sheng , Luo Yong-Chun , Wang Zhu-Yin , Xu Peng-Fei
Published: March 2018

An efficient method for the synthesis of cyclopropane-fused indolines via a Zn2I catalyzed cyclopropanation of indoles and enynones was reported.
Palladium-catalyzed direct approach to α-CF3 aryl ketones from arylboronic acids
Authors: Jiang Bo , Zhang Xiaofei , Yang Chunhao
Published: March 2018

A concise synthesis of α-CF3 aryl ketones was achieved via Pd-catalyzed cross-couplings of arylboronic acids, ICH2CF3 and atmospheric pressure CO.
Boolean-chemotaxis of logibots deciphering the motions of self-propelling microorganisms
Authors: Bhuyan Tamanna , Bhattacharjee Mitradip , Singh Amit Kumar , Ghosh Siddhartha Sankar , Bandyopadhyay Dipankar
Published: March 2018

Self-propelling logibots for AND, NAND, NOT, OR, NOR, and NIMPLY gates emulating chemotaxis of microorganisms.
Physicochemical properties of nanostructured Pd/lanthanide-doped ceria spheres with high catalytic activity for CH4combustion
Authors: Fuentes Rodolfo O. , Acuña Leandro M. , Leyva A. Gabriela , Baker Richard T. , Pan Huiyan , Chen Xiaowei , Delgado-Jaén Juan J.
Published: March 2018

Nanostructured 1 wt% Pd/LnDC spheres exhibited high activity for CH4oxidation with total conversion of CH4attained at a temperature below 400 °C.
A facile route for the synthesis of heterogeneous crystal structures in hierarchical architectures with vacancy-driven defects via the oriented attachment growth mechanism
Authors: Kao Li Cheng , Ye Yifan , Liu Yi-Sheng , Dong Chung Li , Guo Jinghua , Liou Sofia Ya Hsuan
Published: March 2018

One-dimensional rutile TiO2 nanorod arrays with a tunable morphology and intact crystalline sub-nano structures attached are successfully fabricated as a large-scale film based on substrates.
Capitalization of interfacial AlON interactions to achieve stable binder-free porous silicon/carbon anodes
Authors: Han Xiang , Zhang Ziqi , You Run , Zheng Guorui , Li Cheng , Chen Songyan , Yang Yong
Published: March 2018

Synergetic capitalization of structural integrity and strong interfacial interactions to achieve stable binder-free silicon anodes.
Tunable pseudocapacitance storage of MXene by cation pillaring for high performance sodium-ion capacitors
Authors: Luo Jianmin , Fang Cong , Jin Chengbin , Yuan Huadong , Sheng Ouwei , Fang Ruyi , Zhang Wenkui , Huang Hui , Gan Yongping , Xia Yang , Liang Chu , Zhang Jun , Li Weiyang , Tao Xinyong
Published: March 2018

2D transition metal carbide materials called MXene have attracted significant interest in the field of electrochemical energy storage due to their high electrical conductivity and high volumetric capacity.
A visible-near-infrared fluorescent probe for peroxynitrite with large pseudo-Stokes and emission shift via through-bond energy and charge transfers controlled by energy matching
Authors: Guo Yuxin , Lu Gonghao , Zhuo Jiezhen , Wang Jiayu , Li Xue , Zhang Zhiqiang
Published: March 2018

We reported a visible-near-infrared fluorescent probe for peroxynitrite detection with large pseudo-Stokes and emission shifts, based on through-bond energy transfer (TBET) in combination with intramolecular charge transfer (ICT).
Sign reversal of magneto-capacitance in an organic heterojunction based opto-spintronic system
Authors: Luan Lin , Wang Kai , Hu Bin
Published: March 2018

Positive and negative magneto-capacitance can be achieved in an organic opto-spintronic device comprising an NPB/C60 heterojunction. The effect can be ascribed to the competition between the spin-dependent dissociation and bi-molecular recombination mechanisms.
Intriguing electronic insensitivity and high carrier mobility in monolayer hexagonal YN
Authors: Zheng Kai , Yang Xibin , Cui Heping , Yang Qun , Ye Huaiyu , Xiong Daxi , Ingebrandt Sven , Chen Xianping
Published: March 2018

A novel two-dimensional h-YN monolayer with high carrier mobility, insensitive electronic responses to strain and light electron effective masses in its few layer structures was predicted to be a promising candidate for future nanoscale electronic devices in high-strain conditions.
Jamming game for secure orthogonal frequency division multiplexing access systems
Authors: Fadakar Gabalou Vahed , Maham Behrouz , Jahandideh Mojtaba
Published: March 2018

In a communication system, security and reliability have an important impact on the quality of services. In this study, the authors investigate power and subcarrier allocation of a transmitter over the downlink of an orthogonal frequency division multiplexing access system with security considerations among users in the presence of a jammer. This study considers the interaction between the jammer and the transmitter as a zero‐sum game where the objective function is the transmitter's secrecy sum‐rate. To allocate the available resources, they solve the optimisation problem of each player to characterise its optimal strategies. Considering the intractability of the closed form Nash equilibrium for general power regime, they study a matrix game for obtaining maxmin and minmax solutions and demonstrate the validity of inequality . Moreover, they show the existence of pure Nash equilibrium point for low total power regimes of the transmitter and the jammer and attain an expression for each regime. Finally, they examine the jamming power effect on the secrecy sum‐rate and acquire lower and upper bounds of this rate using simulations.
Cyclic gradient descent optimisation for joint MAP estimation of channel and phase noise in orthogonal frequency division multiplexing
Authors: Shrivastav Kamayani , Yadav Rajendra Prasad , Jain Kamal Chand
Published: March 2018

This study addresses the statistically optimal channel estimation for orthogonal frequency division multiplexing systems in the presence of phase noise (PHN). The maximum a posteriori (MAP) cost function for the joint estimation of channel transfer function (CTF) and PHN is presented, which utilises the prior statistical knowledge of PHN spectral components without the assumption of small PHN. The frequency‐domain estimation of unknown frequency selective fading makes the method simpler, compared with the estimation of channel impulse response in time domain. An iterative cyclic gradient descent optimisation algorithm is derived to minimise the cost function over the unknown CTF and PHN. Cramer‐Rao lower bound is analysed and compared with the simulation results to illustrate that the proposed joint MAP estimation can achieve near optimum performance.
Gain enhancement of a dual‐band WLAN microstrip antenna loaded with diagonal pattern metamaterials
Authors: Roy Sourav , Chakraborty Ujjal
Published: March 2018

This communication presents the gain enhancement of a dual‐band WLAN microstrip antenna loaded with left‐handed split‐ring resonator metamaterials. A diagonal repeating pattern of metamaterial unit cells is integrated into the right corner of the substrate to enhance the gain in the lower WLAN band without distorting the upper band characteristics. The proposed antenna covers the different operating bands: 2.4–2.484 and 5.15–5.85 GHz (IEEE 802.11a and b/g/n) for WLAN applications. The gain improvement in the lower operating band is obtained around 3.69 dB which is explained by estimating the Green function of the metamaterial diagonal periodic pattern at the lower resonant frequency. The antenna provides high gain and efficiency and easily printable on a low‐cost FR‐4 substrate. The proposed antenna prototype is developed and tested and experimental results show an excellent agreement with the simulated one.
Analysis of magnetic‐coupling effect on the performances of 2DoF direct‐drive induction motors
Authors: Wang Peixin , Si Jikai , Xie Lujia , Hu Yihua , Hua Wei
Published: March 2018

The coupling between the rotary and linear magnetic fields is a special feature of two‐degrees‐of‐freedom (2DoF) motors. The magnetic‐coupling effect on the performances of 2DoF direct‐drive induction motors (2DoF‐DDIMs) is exposed and investigated based on 3D finite‐element analysis and experiments on a prototyped motor. The performances of the 2DoF‐DDIM are analysed under the conditions of with and without coupling. Further, the speed coupling coefficient is introduced and calculated to consider the effect of the magnetic‐coupling effect on speed. The magnetic‐coupling effect of 2DoF‐DDIM, which leads to induced voltages and currents under rotary or linear motion and lower speed and higher fluctuations under helical motion, enhances with an increase in the source frequency and rotary speed. This research on the magnetic‐coupling effect of 2DoF‐DDIM will provide a significant reference for characteristic research and precise control of 2DoF‐DDIM.
Analytical method to compute bridge stresses in V‐shape IPMs
Authors: Lin Ruiyang , Sudhoff Scott D. , Krousgrill Charles
Published: March 2018

V‐shape interior permanent‐magnet machines (IPMs) have been widely utilised in the industry due to their high‐power density, high efficiency, and low manufacturing cost. There has been growing interest in applying multi‐objective optimisation to the design of electric machines. In the context of V‐shape IPM designs, it is important to include stress analysis in the optimisation design analysis as the steel bridges in the IPM rotor are structural weak points, where high stresses develop. However, traditional finite element analysis (FEA) that is normally used to compute bridge stresses becomes cumbersome due to its high computational cost. In this study, a computationally efficient analytical method is proposed to compute the mechanical stresses developed within the steel bridges in a V‐shape IPM. The proposed method is shown to yield accurate predictions compared with FEA while reducing computational cost. A design study is conducted that demonstrates that the machine performance can be improved by incorporating the proposed structural analysis in a multi‐objective optimisation‐based‐design environment.
End‐user participation in a collaborative distributed voltage control and demand response programme
Authors: Abessi Ahad , Zakariazadeh Alireza , Vahidinasab Vahid , Ghazizadeh Mohammad Sadegh , Mehran Kamyar
Published: March 2018

A new generation of electric appliances with controllable reactive power creates an opportunity for operators in distribution systems to be used as a resource for reactive power support. On the other hand, implementing demand response (DR) programmes as an alternative resource to manage the active power demand may also affect the reactive power balance. Collaborative effect of reactive power support devices and the DR programme is investigated in order to control voltage problem in a distribution network. In the first step, distributed voltage (DV) control and DR methods are considered as individual control actions; then, the hybrid DV control with DR (DVDR) method is proposed to improve the voltage profile. The IEEE 33‐bus distribution standard test system is chosen for validating the novel method, in which the optimum reactive power injection in the candidate buses and demand curtailment in each area are calculated. The proposed DVDR method can better mitigate the voltage problem and the results showed far desirable performance compared with using just DR or DV methods. The proposed method can also curtail less demand in comparison to the DR method.
Optimal operation of a droop‐controlled DCMG with generation and load uncertainties
Authors: Maulik Avirup , Das Debapriya
Published: March 2018

This study presents a method for determining optimal droop settings of dispatchable distributed generation units in a droop‐controlled microgrid (DCMG). The objectives are to (i) minimise the operational cost and (ii) minimise the emission in the DCMG while meeting all the operational constraints. The proposed formulation takes into account the electricity demand, load uncertainties and renewable power uncertainties in the MG. Load and renewable power uncertainties are modelled by Hong's point estimate method. The bi‐objective optimisation problem is solved using fuzzified particle swarm optimisation. The proposed method is validated on a 6‐bus DCMG test system. The results show the effectiveness of the proposed method.
Minimisation of active power losses and number of control adjustments in the optimal reactive dispatch problem
Authors: Mazzini Ana Paula , Asada Eduardo N. , Lage Guilherme Guimarães
Published: March 2018

Trade‐offs between power system's optimal operational performance and the minimal number of control adjustments necessary to attain a desired operating point make optimal reactive dispatch (ORD) solutions practical to system operators. In this study, a multi‐objective ORD model that provides, in terms of weighting factors, trade‐offs between minimal active power losses in transmission systems and minimal number of control adjustments in generator voltages, tap ratios and shunt controls is featured. This multi‐objective ORD is formulated as a mixed‐integer non‐linear programming (MINLP) problem, and the proposed resolution methodology is based on translating the original MINLP problem into non‐linear programming (NLP) problem deploying a sigmoid function, enabling the use of NLP solvers. Both original MINLP and translated NLP models are implemented in GAMS and numerical tests with IEEE test‐systems with up to 300 buses are conducted using DICOPT, KNITRO and CONOPT solvers to validate the proposed ORD model and its resolution methodology. Results demonstrate the relation between active power losses and the number of adjustments in control variables, which is valuable information for operation planning. Another fundamental result is the high computational performance of the method when compared to specialized MINLP solvers.
Enhanced heat transfer characteristics and ampacity analysis of a high‐voltage overhead transmission line under aeolian vibration
Authors: Zhang Meng , Xu Jiankun , Zhao Guifeng , Hao Guanyang
Published: March 2018

High‐voltage overhead transmission lines feature both electrical conductivity and mechanical strength properties. Current studies of the aeolian vibration of transmission lines focus primarily on the mechanical properties of these lines but rarely address the lines’ enhanced heat transfer properties, which directly affect transmission line ampacity. In this study, the authors analyse the vibration‐enhanced heat transfer characteristics of an energised transmission line undergoing aeolian vibration based on the coupled fluid–solid numerical method. The allowable ampacity is calculated using the heat balance method, which accounts for the heat transfer enhancement effect arising from aeolian vibration. Various parameters, such as the vibration amplitude and the ratio between the natural frequency of the conductor and the frequency of the vortex shedding, are investigated. The results demonstrate that aeolian vibration can effectively improve the heat dissipation effect of the conductor and significantly increase the line ampacity. The maximum heat transfer effect occurs in the lock‐in region, in which the allowed ampacity can increase by more than 6%.
Generalised extended‐frequency dynamic phasor model of LCC‐HVDC systems for electromagnetic transient simulations
Authors: Bagheri‐Vandaei Afshin , Filizadeh Shaahin
Published: March 2018

This study introduces a new model for line‐commutated converter high‐voltage direct current (LCC‐HVDC) systems based upon the concept of extended‐frequency dynamic phasors (DPs). The proposed model is able to represent LCC‐HVDC converters during normal as well as abnormal operating modes such as system imbalances and commutation failure by automatically adjusting its parameters based upon converter terminal quantity measurements. The model offers a high level of accuracy with reduced computational burden, and is suitable as a replacement for conventional switch‐based models of LCC in electromagnetic transient (EMT) simulation platforms. The proposed model is thoroughly evaluated against detailed EMT simulations of the CIGRE HVDC benchmark and the IEEE 12‐bus systems with an embedded LCC‐HVDC link. Simulation results confirm that the proposed DP‐based model retains EMT‐grade accuracy even at large simulations steps. Significant acceleration ratios reaching up to an order of magnitude are observed in the simulations using the proposed model compared with conventional EMT models.
Scheduling wind‐battery energy storage hybrid systems in time‐of‐use pricing schemes
Authors: Zhang Xinsong , Gu Juping , Yuan Yue , Hua Liang , Shen Yanchi
Published: March 2018

Battery energy storage systems (BESSs) are incorporated into wind farms to gain more profits by shifting energy over time and to track predetermined power schedules. In operations, charging/discharging power of the BESS is adjusted flexibly to follow the power schedules of the wind‐BESS hybrid systems (W‐BESS‐HS), which are set to be the sum of short‐term predicted wind powers and charging/discharging schedules of the BESS. In order to extend lifetime of batteries, the BESS operation is subject to a sequential charging/discharging state sequence, which is predetermined according to time‐of‐use (ToU) pricing schemes. An iteration scheme is presented to update scheduled charging/discharging rates of the BESS according to simulation results based on sequential Monte‐Carlo simulation (SMCS) technology so that the W‐BESS‐HS can not only meet a probabilistic requirement on generation schedule tracking but also gain further economic benefits by achieving a trade‐off between punishments resulted from power deviations and wind power curtailment losses. In the SMCS simulation, a series of real‐time indices are presented to evaluate performances of the W‐BESS‐HS at every dispatching interval and provide updating directions of the iteration scheme. The research work can provide theoretical support when operating the W‐BESS‐HS in ToU pricing schemes.
Equivalent input disturbance‐based robust LFC strategy for power system with wind farms
Authors: Liu Fang , Ma Junjie
Published: March 2018

Due to the intermittent power generation, wind farms integrated into the grid may cause a problem of large frequency fluctuation, when the capacity of load frequency control (LFC) is not enough to compensate the unbalance between the generation and the load demand. In this study, a new robust LFC strategy against load disturbance and wind power fluctuation is proposed to improve the disturbance‐resistant performance of the power system with wind farms. First, a simplified model of the power system with wind farms is established without considering the accurate model information. Then, a control scheme based on the compensation of equivalent input disturbance (EID) is introduced, and a method of EID estimation is presented. The robust LFC design addresses various disturbances and internal/external uncertainties of power systems. Finally, to evaluate the effectiveness of the proposed method, two case studies are carried out and the performance comparisons with the classical proportional–integral–derivative control scheme are used to confirm the proposed method.
Power transformers monitoring based on electrical measurements: state of the art
Authors: Meira Matias , Ruschetti Cristian R. , Álvarez Raúl E. , Verucchi Carlos J.
Published: March 2018

Faults diagnosis in power transformers has been traditionally based on the insulation resistance measurement, polarisation index, analysis of dissolved gasses in oil, dissipation/power factor measurement, and partial discharges within many other alternatives. Originally, all these techniques presented an offline implementation, that is, with the transformer out of service. Currently, some of them, such as partial discharges measurement or gas analysis (gas chromatography), are carried out online in those cases in which the importance of a machine justifies it. These techniques have been recently complemented with new alternatives, such as frequency response analysis, an offline application technique. At the same time, in recent years, development of online diagnostic strategies has been carried out only based in monitoring of electrical variables. These techniques have the advantage of being economical in relation to traditional ones. Its development are incipient and with high growth potential. This study presents a review of the most important techniques and a critical comparison between them.