bluuebunny/crossref_metadata_2025 huggingface dataset:
TRB3 interacts with ERK and JNK and contributes to the proliferation, apoptosis, and migration of lung adenocarcinoma cells
Authors: Cao Xiaopei , Fang Xiaoyu , Malik Waqar Saleem , He Yuanzhou , Li Xiaochen , Xie Min , Sun Wei , Xu Yongjian , Liu Xiansheng
Published: June 2019

Tribbles homolog 3 (TRB3) has been accounted for regulation of a few cell processes through interaction with other significant proteins. The molecular mechanisms underlying TRB3 in tumorigenesis in lung adenocarcinoma have not been entirely elucidated. The present study is aimed at determining the function and fundamental mechanisms of TRB3 in lung adenocarcinoma progression. TRB3 was highly expressed in A549 and H1299 cells and lung adenocarcinoma tissues compared with human bronchial epithelial cells (HBEpC) and adjacent normal lung tissues. Hypoxia significantly upregulated the expression of TRB3 protein in A549 and H1299 cells in a time‐dependent way. Gene expression profiling interactive analysis data analysis indicated that patients with lung adenocarcinoma with excessive expression of TRB3 mRNA had fundamentally shorter survival time. TRB3 knockdown in A549 cells can inhibit cell proliferation and migration, and promote cell apoptosis. TRB3 knockdown reduced the expression of p‐ERK and p‐JNK, but did not affect the expression of p‐P38 MAPK. TRB3 overexpression enhances the malignant transformation abilities of HBEpC such as cell proliferation, migration and colony formation, which could be reversed by U0126 and SP600125. TRB3 overexpression promotes the phosphorylation of extracellular signal‐regulated kinase (ERK) and c‐Jun N‐terminal kinase (JNK) but was not affected by U0126 and SP600125. The results of coimmunoprecipitation experiments indicated that TRB3 binds directly to ERK and JNK. This study suggests that TRB3 has a potentially carcinogenic role in lung adenocarcinoma by binding to ERK and JNK and promoting the phosphorylation of ERK and JNK. TRB3 can be a possible therapeutic focus for lung adenocarcinoma.
microRNA‐141 is associated with hepatic steatosis by downregulating the sirtuin1/AMP‐activated protein kinase pathway in hepatocytes
Authors: Yousefi Zeynab , Nourbakhsh Mitra , Abdolvahabi Zohreh , Ghorbanhosseini Seyedeh‐Sara , Hesari Zahra , Yarahmadi Sahar , Ezzati‐Mobasser Samira , Seiri Parvane , Borji Mohammad , Meshkani Reza , Malek Mojtaba
Published: June 2019

Sirtuin1 (SIRT1) is a crucial regulator of metabolism and it is implicated in the metabolic pathophysiology of several disorders inclusive of Type 2 diabetes and fatty liver disease (NAFLD). The aim of this study was to investigate the role of miR‐141 in hepatic steatosis via regulation of SIRT1/AMP‐activated protein kinase (AMPK) pathway in hepatocytes. Liver hepatocellular cells (HepG2) were treated with high concentration of glucose to be subsequently used for the assessment of miR‐141 and SIRT1 levels in a model of hepatic steatosis. On the other hand, cells were transfected with miR‐141 to investigate its effect on hepatocyte steatosis and viability as well as SIRT1 expression and activity along with AMPK phosphorylation. Targeting of SIRT1 by miR‐141 was evaluated by bioinformatics tools and confirmed by luciferase reporter assay. Following the intracellular accumulation of lipids in HepG2 cells, the level of miR‐141 was increased while SIRT1 mRNA and protein levels, as well as AMPK phosphorylation, was decreased. Transfection with miR‐141 mimic significantly downregulated SIRT1 expression and activity while miR‐141 inhibitor had the opposite effects. Additionally, modulation of miR‐141 levels significantly influenced AMPK phosphorylation status. The results of luciferase reporter assay verified SIRT1 to be directly targeted by miR‐141. miR‐141 could effectively suppress SIRT1 and lead to decreased AMPK phosphorylation in HepG2 cells. Thus, miR‐141/SIRT1/AMPK signaling pathway may be considered a potential target for the therapeutic management of NAFLD.
The lncRNA SNHG16 affects prognosis in hepatocellular carcinoma by regulating p62 expression
Authors: Zhong Jian‐Hong , Xiang Xiao , Wang Yan‐Yan , Liu Xu , Qi Lu‐Nan , Luo Cheng‐Piao , Wei Wen‐E , You Xue‐Mei , Ma Liang , Xiang Bang‐De , Li Le‐Qun
Published: June 2019

Long noncoding RNAs (lncRNAs) regulate tumor development and progression by promoting proliferation, invasion, and metastasis. The oncogenic role of lncRNA SNHG16 in hepatocellular carcinoma (HCC) has not been revealed. LncRNA SNHG16 is upregulated in HCC and correlates with poorer prognosis. Patients with high SNHG16 expression showed lower rates of overall and disease‐free survival than patients with low SNHG16 expression. Multivariate Cox regression revealed that SNHG16 expression was an independent predictor of poor overall and disease‐free survival. In vitro, SNHG16 promoted HCC cell proliferation, migration, and invasion while inhibiting apoptosis; in vivo, it accelerated tumor development. Altering SNHG16 expression altered levels of miR‐17‐5p, which in turn modified expression of p62, which has been shown to regulate the mTOR and NF‐κB pathways. Indeed, altering SNHG16 expression in HCC cells activated mTOR and NF‐κB signaling. These results reveal a potential mechanism for the oncogenic role of SNHG16 in HCC. SNHG16 may therefore be a promising diagnostic marker as well as therapeutic target in HCC.
hsa_circ_0000745 promotes cervical cancer by increasing cell proliferation, migration, and invasion
Authors: Jiao Jun , Zhang Teng , Jiao Xinlin , Huang Tingting , Zhao Lu , Ma Daoxin , Cui Baoxia
Published: June 2019

Circular RNAs (circRNAs) participate in gene regulation and malignant tumor progression, including uterine cervical cancer (CC). In this study, the expression profile of circRNAs in CC was detected using circRNA microarrays. Then, we selected hsa_circ_0000745 for further examination from the significantly dysregulated circRNAs. Proliferation assays, Transwell assays, quantitative reverse transcription polymerase chain reaction, western blot analysis and tumorigenesis tests in vivo were used to validate the role of hsa_circ_0000745 in CC. hsa_circ_0000745 was upregulated in CC, and its level positively correlated with the level of its linear messenger RNA isoform. Patients with poorly differentiated tumors or vascular/lymphatic invasion presented higher expression of hsa_circ_0000745. The role of hsa_circ_0000745 was illuminated by knocking down hsa_circ_0000745 in CC cells, and the results revealed that reducing hsa_circ_0000745 inhibited cell proliferation, migration, and invasion in CC by upregulating E‐cadherin (E‐cad) expression. In summary, as a tumor promoter in CC, hsa_circ_0000745 enhances the cell's ability to proliferate, migrate, and invade by reducing the expression of E‐cad. hsa_circ_0000745 is a candidate target for the treatment of CC in the clinic.
Treatment with metformin and sorafenib alleviates endometrial hyperplasia in polycystic ovary syndrome by promoting apoptosis via synergically regulating autophagy
Authors: Wang Qian‐qing , Guo Xiang‐cui , Li Li , Gao Zhi‐hui , Ji Mei
Published: June 2019

This study aimed to investigate the molecular mechanisms underlying the roles of metformin (MET) and Sorafenib (SOR) in the treatment of endometrial hyperplasia (EH) in polycystic ovary syndrome (PCOS). Effects of MET and SOR on the area of endometrium and myometrium were detected. Western blot analysis and immunohistochemistry assays were carried out to detect the levels of mammalian target of rapamycin complex 1 (mTORC1), mTORC2, LC3‐II, P62, and Caspase‐3 in rats and cultured cells. Furthermore, cell counting kit‐8 assay and flow cytometry analysis was carried out to determine the apoptotic profiles of treated cells. MET and SOR could apparently decrease the areas of endometrium and myometrium in PCOS. MET notably enhanced the expression of LC3‐II and Caspase‐3 in PCOS while substantially reducing the level of mTORC1 and P62. Similarly, SOR also enhanced the expression of LC3‐II and Caspase‐3 in PCOS while substantially reducing the level of mTORC2 and P62. Treatment with MET and SOR significantly inhibited the proliferation of HCC‐94 and HEC‐1‐A cells while promoting their apoptosis by upregulating the expression of Caspase‐3. In cells treated with MET, the expression of mTORC1 and LC3‐II was upregulated while the expression of P62 was downregulated. Similarly, in cells treated with SOR, the expression of mTORC2 and LC3‐II was also upregulated while the expression of P62 was also downregulated. Furthermore, MET showed no effect on mTORC2 expression, while SOR showed no effect on mTORC1 expression. In this study, we suggested that MET and SOR alleviated the risk of EH in PCOS via the mTORC1/autophagy/apoptosis axis and mTORC2/autophagy/apoptosis axis, respectively.
Effect of preventive or therapeutic treatment with angiotensin 1–7 in a model of bleomycin-induced lung fibrosis in mice
Authors: Rago Flávia , Melo Eliza Mathias , Kraemer Lucas , Galvão Izabela , Cassali Geovanni D , Santos Robson A S , Russo Remo C , Teixeira Mauro Martins
Published: June 2019

Idiopathic pulmonary fibrosis is characterized by aberrant fibroblast activation and excessive collagen deposition that may eventually lead to organ dysfunction. Lung fibrosis is frequently observed in cancer patients undergoing bleomycin (BLM) treatment. Therefore, BLM instillation in mice is the most frequent model used to investigate pulmonary fibrosis. Angiotensin 1–7 [Ang-(1-7)] is a heptapeptide with anti-inflammatory and proresolving activity. Here, we studied the effects of preventive and therapeutic oral administration of Ang-(1-7) in a model of BLM-induced lung fibrosis in mice. Male C57Bl/6j mice were instilled with BLM and followed for weight loss and survival or euthanized to examine pulmonary inflammation, fibrosis, and lung function. For preventive treatment, mice were treated with Ang-(1-7) 1 h before instillation and then twice daily. We observed that preventive treatment with Ang-(1-7) decreased weight loss, inflammation and collagen deposition, increased survival, and ameliorated lung function. Therapeutic treatment with Ang-(1-7), starting 3 days after BLM instillation resulted in decreased inflammation, decreased collagen deposition, and ameliorated lung function, although the effects were of lower magnitude than the preventive treatment. Therapeutic treatment with Ang-(1-7) starting 7 or 14 days after BLM instillation failed to alter any of the changes observed. Therefore, although oral preventive treatment with Ang-(1-7) is effective to decrease pulmonary inflammation, fibrosis, and functional changes induced by BLM, therapeutic effects are much less significant, arguing against its use in patients with chronic fibrosis. It remains to be determined whether other proresolving molecules will have better therapeutic effects in the context of chronic pulmonary fibrosis.
Distinct effects of intrinsic motivation and extrinsic rewards on radical and incremental creativity: The moderating role of goal orientations
Authors: Malik Muhammad Abdur Rahman , Choi Jin Nam , Butt Arif Nazir
Published: June 2019

Previous studies have investigated the role of intrinsic motivation and extrinsic rewards in enhancing employee creativity. However, the possibility that these motivational factors affect the creativity of different types remains largely unexplored, particularly in the organizational settings. Moreover, the potential that personality traits may moderate the function of these motivational factors toward creativity is another underresearched area. By drawing on the person–situation interaction perspective, we propose that both intrinsic motivation and extrinsic rewards predict creativity but of different types. Thus, we diverge from the view that creativity is a uniform criterion domain by adopting the distinction between radical and incremental creativity. Our empirical analysis of 220 independent employee–supervisor dyads confirmed that intrinsic motivation and extrinsic rewards predict radical and incremental creativity, respectively. Moreover, the effects of intrinsic motivation on radical and incremental creativity are more positive for employees with higher learning goal orientation. By contrast, the effect of extrinsic rewards on incremental creativity is more positive for employees with higher performance goal orientation. This study offers elaborate and nuanced perspectives and insights into the role of different motivational processes in the development of different types of creativity.
Distant political‐economic forces and global‐to‐local pathway to impacts on forests of Ejido landscapes across Yucatán, México
Authors: Lawrence Ted J. , Morreale Stephen J. , Stedman Richard C.
Published: June 2019

Indigenous community land tenure in many locations worldwide is shifting towards individually parcelized and privatized systems. Among the drivers of this shifting land tenure are distant political‐economic forces and commodity markets, from local to global. Accompanying the observed land tenure changes are shifts in livelihoods, away from subsistence‐based and toward market‐oriented activities. These changes can ultimately impact land use, land cover, and biodiversity conservation. We investigated a global‐to‐local causal pathway, from agriculture, livestock, and forestry production for distant markets, extending through shifting land tenure and livelihoods, to impacts on forest cover within ejidos (a type of community landholding) across Yucatán, México, where Maya people are the primary land managers. To reveal this causal pathway, we conducted exploratory data analysis, using ordinary least squares regression, mapped variables, and variographic analyses to assess spatial patterns and correlations. We further explored relationships among variables using spatially explicit simultaneous autoregressive models. We found that commodity production for distant markets is strongly related to parcelized ejido lands, which in turn are often deforested. Conversely, community‐managed lands, which traditionally involve subsistence‐based agroforestry, are much more likely to be densely forested. Overall, we conclude that recent deforestation of ejido lands across the State is, at least partly, the result of shifting land tenure and livelihoods due to the increasing presence of commodity markets. Moreover, we conclude that community‐managed lands and associated subsistence livelihoods can attenuate deforestation and potentially advance forest and biodiversity conservation across México and elsewhere.
Assessing the impact of sleep time on truck driver performance using a recurrent event model
Authors: Liu Yi , Guo Feng , Hanowski Richard J.
Published: June 2019

Driver fatigue is a major safety concern for commercial truck drivers and is directly related to the total hours of sleep prior to a working shift. To evaluate changes in driving performance over a long on‐duty driving period, we propose a mixed Poisson process recurrent‐event model with time‐varying coefficients. We use data from 96 commercial truck drivers whose trucks were instrumented with an advanced in situ data acquisition system. The driving performance is measured by unintentional lane deviation events, a known performance deterioration related to fatigue. Driver sleep time and other activities are extracted from a detailed activity register. The time‐varying coefficients are used to model the baseline intensity and difference among three cohorts of shifts in which the driver slept less than 7 hours, between 7 to 9 hours, and more than 9 hours prior to driving. We use the penalized B‐splines approach to model the time‐varying coefficients and an expectation‐maximization algorithm with embedded penalized quasi‐likelihood approximation for parameter estimation. Simulation studies show that the proposed model fits low and high event rate data well. The results show a significantly higher intensity after 8 hours of on‐duty driving for shifts with less than 7 hours of sleep prior to work. The study also shows drivers tend to self‐adjust sleep duration, total driving hours, and breaks. This study provides crucial insight into the impact of sleep time on driving performance for commercial truck drivers and highlights the on‐road safety implications of insufficient sleep and breaks while driving.
Copper isotopes as possible neoplasia biomarkers in captive wild felids
Authors: Gourlan Alexandra T. , Douay Guillaume , Telouk Philippe
Published: June 2019

The longevity of zoo animals is increasing due to continuous improvement in husbandry and veterinary medicine. However, increasing age is correlated to a higher prevalence of neoplasia. Despite tremendous improvement in diagnoses and monitoring capacities, cancers are still a challenge for veterinarians within the global zoo community. The recent use of copper isotopes as biomarkers for neoplasia in both human and veterinary medicine is a promising and cost‐effective diagnostic tool.

Two hundred and twenty‐nine serum samples from 10 different species of wild felids under human care were processed through mass spectrometry to determine the ratio of heavy and light copper isotopes (65Cu/63Cu). The results of this preliminary study exhibit an important variability between felid species, with a ratio ranging between −1.71 and 0.63. Additionally, copper isotopes seem to be a promising diagnostic tool in monitoring cancer in wild animals, as in human medicine, where the isotopic ratio decreases significantly with time in the presence of a tumor.
Rethinking Business Models in the Great Depression: The Failure of America's Vacuum Cleaner Industry
Authors: Scott Peter
Published: June 2019

We examine the factors leading to the onset of organizational rigidities in the dominant vacuum cleaner firms of the 1920s, Hoover and Eureka. Strategies aimed at strengthening organizational commitment, in conjunction with low levels of organizational diversity—owing to managerial hierarchies dominated by men recruited from the sales force—restricted organizational flexibility and adaptability while accentuating resistance to change. In conjunction with core competencies that largely reflected conditions in the previous rapid-growth phases of both firms, organization rigidity left them vulnerable to the new conditions of the Depression, including product and value chain innovation by a new entrant, Electrolux.
Ventilation Pathways for the North Pacific Oxygen Deficient Zone
Authors: Margolskee A. , Frenzel H. , Emerson S. , Deutsch C.
Published: June 2019

Oxygen deficient zones (ODZs) in the tropical ocean exert a profound influence on global biogeochemical cycles, but the factors that regulate their long‐term structure and sensitivity to oceanic change remain poorly understood. We analyzed hydrographic observations and a high‐resolution physical/biogeochemical model to diagnose the primary pathways that ventilate the tropical Pacific ODZs. Historical and recent autonomous observations reveal pronounced and widespread O2 peaks, termed secondary oxygen maxima (SOMs), within the depths of the broader O2 minimum layer, especially at the equatorward edge of both northern and southern ODZs. In the northern ODZ, Lagrangian particle tracking in an eddy‐permitting numerical model simulation attributes these features to intrusions of the Northern Subsurface Countercurrent along the equatorial edge of the ODZ. Zonal subsurface jets also ventilate the poleward edge of the northern ODZ but induce a smaller O2 flux and do not yield detectable SOMs. Along the ODZ's eastern boundary, oxygenation is achieved by the seasonal cycle of upwelling of low‐O2 water onto the continental shelf, followed by downwelling of O2‐replenished near‐surface waters back into the ODZ. Waters entering the northern Pacific ODZ originate from the extratropics in both hemispheres, but two thirds are from the Southern Hemisphere and arrive later and with a wider range of transit times. These results suggest that predicting future changes in the large Pacific ODZs will require a better understanding of the climate sensitivity of the narrow zonal jets and seasonal dynamics of coastal upwelling that supply their O2.
Highly porous, low band-gap NixMn3−xO4(0.55 ≤x≤ 1.2) spinel nanoparticles within situcoated carbon as advanced cathode materials for zinc-ion batteries
Authors: Long Jun , Gu Jinxing , Yang Zhanhong , Mao Jianfeng , Hao Junnan , Chen Zhongfang , Guo Zaiping
Published: June 2019

Aqueous zinc ion batteries (ZIBs) are emerging as a highly promising alternative technology for grid-scale applications where high safety, environmental-friendliness, and high specific capacities are needed.
Construction of strawberry-like Ni3S2@Co9S8 heteronanoparticle-embedded biomass-derived 3D N-doped hierarchical porous carbon for ultrahigh energy density supercapacitors
Authors: Wang Shifu , Xiao Zuoyi , Zhai Shangru , Wang Haisong , Cai Weijie , Qin Longfei , Huang Jianying , Zhao Di , Li Zhongcheng , An Qingda
Published: June 2019

The design of advanced supercapacitors requires electrode materials that combine high surface area with a developed hierarchical porous structure to facilitate ion transport and electrolyte permeability.
Using CoS cathode materials with 3D hierarchical porosity and an ionic liquid (IL) as an electrolyte additive for high capacity rechargeable magnesium batteries
Authors: Pan Mingguang , Zou Jianxin , Laine Richard , Khan Darvaish , Guo Rui , Zeng Xiaoqin , Ding Wenjiang
Published: June 2019

Developing high capacity, rechargeable magnesium batteries is highly desired to meet increasing energy demands while targeting viable replacements for lithium batteries.
Highly efficient and thermally stable single-activator white-emitting phosphor K2Ca(PO4)F:Eu2+ for white light-emitting diodes
Authors: Li Ying , Qiu Zhongxian , Zhang Jilin , Ji Xiaoyu , Zhang Xinguo , Liao Shuzhen , Zhou Wenli , Yu Liping , Lian Shixun
Published: June 2019

Highly efficient and stable white emission is realized in a single-doped K2Ca(PO4)F:Eu2+ phosphor with Eu2+ on both K+ and Ca2+ sites.
Hepatoprotective activity of raspberry ketone is mediated via inhibition of the NF-κB/TNF-α/caspase axis and mitochondrial apoptosis in chemically induced acute liver injury
Authors: Fouad Dalia , Badr Amira , Attia Hala A.
Published: June 2019

Raspberry Ketone (RK) is a natural phenolic compound which is marketed nowadays as a popular weight-reducing remedy, with reported antioxidant and anti-inflammatory activities. However, its biological activity is not fully elucidated. Hepatotoxicity is the leading cause of acute liver failure in Europe and North America, and its management is still challenging. Therefore, this study aimed to assess the therapeutic detoxification activity of RK against liver injury in vivo and to explore the underlying mechanisms using carbon tetrachloride (CCl4)-induced hepatotoxicity as a model. First, a dose–response study using 4 different doses, 25, 50, 100, and 200 mg kg−1 day−1, of RK was conducted. RK was administered for 5 days as a pretreatment, followed by a single dose of CCl4 (1 ml kg−1, 1 : 1 v/v CCl4 : olive oil). The RK dose of 200 mg kg−1 showed the greatest protective effect and was selected for further investigations. CCl4 hepatotoxicity was confirmed by elevation of liver enzymes, and histopathological examination. CCl4-induced oxidative stress was evident from increased lipid peroxidation measured as thiobarbituric acid reactive substances (TBARS) along with depleted superoxide dismutase (SOD), reduced glutathione (GSH), and total antioxidant capacity (TAC). Increased oxidative stress was associated with increased cytochrome c expression with subsequent activation of caspase-9 and caspase-3, in addition to DNA fragmentation reflecting apoptosis. CCl4 also induced the expression of inflammatory cytokines (NF-κB and TNF-α). Interestingly, RK hepatoprotective activity was evident from the reduction of liver enzymes, and maintenance of hepatocyte integrity and microstructures as evaluated by histopathological examination using H and E, and transmission electron microscopy. The antioxidant activity of RK was demonstrated by the increase of TAC, SOD, and GSH, with a concomitant decrease of the TBARS level. Moreover, RK pretreatment inhibited CCl4-induced upregulation of inflammatory mediators. RK antiapoptotic activity was indicated by the reduction of the expression of cytoplasmic cytochrome-C, a decrease of caspases, and inhibition of DNA fragmentation. In conclusion, this study demonstrates that RK is a promising hepatoprotective agent. The underlying mechanisms include antioxidant, anti-inflammatory, and anti-apoptotic activities. This is the first study reporting RK hepatoprotective activity in acute hepatic injury and approves its antiapoptotic effect in the liver.
Evaluation of next‐generation low‐power communication technology to replace GSM in IoT‐applications
Authors: Durand Thomas G. , Visagie Lourens , Booysen Marthinus J.
Published: June 2019

The large demand for smart metering and control, asset tracking, remote monitoring, and other applications has resulted in the emergence of innovative new internet of things (IoT) low‐power wide‐area networks (LPWANs) featuring low power consumption, low cost, high scalability and low data rate transmissions. This article compares the performance of LoRaWAN, Sigfox, and NB‐IoT as emerging technologies, in terms of power consumption, throughput, scalability, and range. For practical reasons, the comparison also includes cellular GPRS. Although GPRS does not fit the description of LPWAN technologies, it is a legacy method for IoT communications and provides insight into application areas where LPWAN technology can be applied. The study gives a clear comparative overview of the advantages and shortcomings of the various communication networks and highlights the most suitable applications cases for each technology on the basis of the tested metrics.
Comparison between statistical and principal component analysis in reduction of near‐field FDTD data
Authors: Ramos Glaucio L. , Rodrigues Gustavo F. , Camilo Franz M. , Rego Cássio G.
Published: June 2019

We present a comparison of statistical and principal component analyses (PCA) for reducing the amount of near‐field data required as an input to a time‐domain spherical‐multipole near‐to‐far‐field transformation. Such transformations are necessary for finite‐difference time‐domain (FDTD) simulations that typically only model the near‐field. The authors demonstrate their approach for the case of far‐fields scattered by a dielectric sphere. For a threshold value of , the PCA technique reduced the data required by 32%, using 12 components. A similar compression was achieved with statistical analysis, when the threshold is set at . Their work shows that the proposed statistical compression is preferable because it has simpler implementation and low‐cost processing, when implemented together with the NFF transformation code.
Microstrip monopole antenna with a novel UC‐EBG for 2.4 GHz WBAN applications
Authors: Gao Guoping , Zhang Ruifeng , Yang Chen , Meng Huijia , Geng Wenfei , Hu Bin
Published: June 2019

A microstrip monopole antenna backed with a novel uniplanar compact electromagnetic bandgap (UC‐EBG) structure for 2.4 GHz wireless body area network applications is proposed here. The proposed antenna has a size reduction of 50% when the number of EBG array is optimised from 3 × 4 to 2× 3, while the radiation performance is almost invariable at the same time. The operating frequency band under different conditions has the capability of covering the 2.4–2.4835 GHz industrial, scientific, and medical band. Due to the addition of 2×3 UC‐EBG on the back, the radiation patterns become unidirectional, and the measured average gain increases from 2.1 to 5.6 dB. Meanwhile, the cross‐polarisation of the monopole antenna can be suppressed prominently by the EBG array. The simulated specific absorption rate values are 0.0536 W/kg under 1 g standard and 0.0296 W/kg under 10 g standard, which are far below the limitation of USA and Europe. These results can manifest the reliable wearable performance of the proposed antenna.
Coordinated‐control strategy of scalable superconducting magnetic energy storage under an unbalanced voltage condition
Authors: Lin Xiaodong , Lei Yong , Fu Weizhen , Zhu Yingwei , Zhou Qun
Published: June 2019

Modular multilevel converters (MMCs) have the advantages of high‐power density and small‐harmonic distortion because of their modularity and flexibility, thus providing a new avenue for research into scalable superconducting magnetic energy storage (SMES) in renewable energy generation. This study presents coordinated control for a three‐phase four‐wire (3P4W) MMC‐based SMES system under unbalanced voltage applications. First, the positive‐ and negative‐sequence mathematical models and the port‐controlled Hamiltonian with dissipation model of the 3P4W MMC‐SMES system are established by introducing an additional path for zero‐sequence current. Second, a multi‐objective passivity‐based control strategy that can effectively improve the power quality and system robustness and eliminate both double‐frequency active and reactive power fluctuations or double‐frequency active power fluctuation and negative‐sequence current is proposed. The simulation results based on MATLAB/Simulink demonstrate the effectiveness of the proposed topology of the SMES and its control strategy.
Evaluation of battery‐renewable hybrid stations in small‐isolated systems
Authors: Psarros Georgios N. , Papathanassiou Stavros A.
Published: June 2019

Hybrid power stations (HPSs) are virtual power plants comprising storage and renewable energy source facilities operated in a coordinated manner as dispatchable stations. The HPS concept has been introduced as a means to increase renewable penetration in saturated island systems. The main objective of this study is to shed light on the operation of battery‐based HPSs in small‐island systems and their investment feasibility. Anticipated benefits for the island system are quantified in terms of system production cost and renewable penetration, while the exploitation of available renewable energy by the HPS is analyzed and the internal operation of its components is evaluated. A mixed integer linear programming generation scheduling approach is used to conduct daily and annual simulations of the entire island generation system, while at the same time optimising the internal management of the HPS as well. Based on the operating results thus obtained, the economic feasibility of battery‐based HPS investments using wind, photovoltaics or their combination as the renewable generation component is assessed, by utilising the levelised cost of energy as the primary evaluation index and accounting for the life expectancy of the HPS battery storage system.
Frequency control of power system including PV and wind farms by using output frequency band control of HVDC interconnection line
Authors: Tada Kimiko , Sato Takamasa , Umemura Atsushi , Takahashi Rion , Tamura Junji , Matsumura Yoshiharu , Yamaguchi Daisuke , Kudo Hirooki , Niiyama Masakazu , Taki Yasuhito
Published: June 2019

Due to serious environmental issues in recent years, renewable energy has been focused on all over the world to solve the issues. However, because of indirect characteristics such as variations of solar radiation intensity or wind speeds, the output of power generation utilizing renewable energy becomes unstable. As a result, frequency and voltage in the power system can fluctuate. To solve this problem, various methods to control the frequency variations have been studied and reported until now, one of which is based on High voltage direct current (HVDC) transmission line. This paper proposes a novel control scheme to reduce the frequency variations due to large penetrations of wind power and photovoltaic (PV) power, which is introduced to power flow control of HVDC transmission line with utilizing a notch‐band pass filter in its frequency control system.
Modifying the control design of DFIG‐based wind turbines in order to inhibit power system oscillations
Authors: Jafarian Mohammad , Asefi Mohammad‐Naser
Published: June 2019

Providing additional damping for system electromechanical oscillations through doubly fed induction generator (DFIG)‐based wind turbines is investigated in this study. In this regard, first an objective function is developed to tune the DFIG control gains, aim to maximise the wind farm (WF) contribution to system oscillation damping, but it is shown that it causes a decrease in the damping of DFIG stator mode. In other words, with the current DFIG control design, it is not possible to improve both the small signal stability of the power system and the dynamic stability of WF together. Afterwards, two high‐pass filters are suggested to be employed in the control design of DFIG. It is shown that with the modified control design, it is possible to improve the system oscillation without spoiling the dynamic stability of the WF itself. Eigenvalue analysis is performed to validate the effectiveness of the modified control design.
Perspectives on solar power in dense urban areas – with Copenhagen International School as case study
Authors: Nørgaard Per , Poder Søren H.
Published: June 2019

With the solar power panels as integrated surface elements in new building constructions, solar power will be economic attractive in urban areas, close to the power consumption. In the new dense urban areas, the rooftop areas will be attractive for other purposes, like terraces and green roofs. The solar power panels may instead be placed at the facades of the buildings – this is especially relevant at high geographic latitudes, where the altitude of the sun is low. It may even make sense to mount panels at all facades, better distributing the generation over the day.
Two‐step market clearing for local energy trading in feeder‐based markets
Authors: Khorasany Mohsen , Mishra Yateendra , Ledwich Gerard
Published: June 2019

Recent innovations in information and communication technologies (ICT) provide new opportunities and challenges for the integration of distributed energy resources (DERs) into the energy supply system as active market players. By increasing the integration of DERs, the novel market platform should be designed for these new market players to provide correct incentives for them to join the market and follow market rules. In this paper, a feeder‐based market is proposed for local energy trading among prosumers and consumers in the distribution system to share energy with other players in the local market and with neighbourhood areas. A two‐step market clearing (2SMC) mechanism is proposed for market clearing, in which in the first step, each local market is cleared independently to determine the market clearing price and in the second step, players can trade energy with neighbourhood areas. In comparison to a centralised market, the proposed method is scalable and reduces computation overheads, because instead of clearing market for a large number of players, the market is cleared for a fewer number of players. Case studies demonstrate the efficiency and effectiveness of the proposed market clearing method in increasing social welfare and reducing computation time.
Primary frequency regulation supported by battery storage systems in power system dominated by renewable energy sources
Authors: Turk Ana , Sandelic Monika , Noto Giancarlo , Pillai Jayakrishnan R. , Chaudhary Sanjay K.
Published: June 2019

In recent years, the transition process towards clean energy has caused many challenges to power systems, especially in the field of operation and power system control. Conventional generators, which have been providing ancillary services to maintain stability and reliability to the system, are being replaced by intermittent renewable generators. Therefore, maintaining system quality and stability in terms of power system frequency control is one of the major challenges that require new resources and system integration. Battery energy storage systems (BESSs), as fast‐acting energy storage systems, with the capability to act as a controllable source and sink of electricity are one of the prominent solutions for system services. This study investigates the primary frequency control provision from BESSs to the renewable energy sources dominated power system. The simulation results for various cases have shown that integration of BESSs has significantly improved power system frequency stability.
Stochastic scheduling of battery energy storage system for large‐scale wind power penetration
Authors: Prasanta Gupta Pranda , Jain Prerna , Sharma Suman , Chand Sharma Kailash , Bhakar Rohit
Published: June 2019

High penetrations of wind generation have intermittency and volatility issues in deregulated power system. With increasing penetration of wind power, independent system operator (ISO) faces an enormous challenge in secure operation with intermittency and uncertainty of renewable energy resources. To handle these issues, battery energy storage system (BESS) is a probable solution for enhancing the wind penetration in the electric grid. In this regard, this article proposes a stochastic security constrained unit commitment (SCUC) with BESS considering wind uncertainty. The proposed approach is formulated and solved by Benders decomposition (BD) method which reduces computational time. The goal is to detect the optimal amount of SCUC, locational marginal price (LMP), wind curtailment, and line contingency by performing DC optimal power flow (DCOPF). Numerical case studies are investigated in detail using IEEE Reliability test system (RTS) 24‐bus network and simulation results are found to be inspiring.
Coordinated active and reactive power control for overvoltage mitigation in physical LV microgrids
Authors: Mai Tam T. , Haque Niyam A.N.M.M. , Vo Hau T. , Nguyen Phuong H.
Published: June 2019

The share of photovoltaic (PV) systems in the distribution networks is rapidly growing, leading to the common issue of overvoltage at the end of distribution feeders during the periods when peak generation is surplus to consumption. In this study, a hierarchical control is proposed to mitigate overvoltage at the point of connection of PV systems in physical low‐voltage microgrids. The proposed mechanism is comprised of primary and secondary control layers to tackle the overvoltage problems given the communication capability is available. This mechanism employs a multi‐objective optimisation approach to effectively coordinate curtailed active power and absorbed reactive power of the PV inverters with the aim of minimising the active power curtailment. The feasibility of the proposed control approach is successfully verified through simulations on a simplified LV network.
Ordinal optimisation approach for complex distribution network reconfiguration
Authors: Xing Haijun , Hong Shaoyun
Published: June 2019

The increasing complexity of the distribution system makes the practical distribution network operation much difficult. This paper presents an ordinal optimisation (OO) approach to solve the distribution network reconfiguration, which is an NP‐ hard problem with discrete control variables. OO uses crude and computationally fast model to reduce the search space. The spirit of OO is to seek the good enough solution instead of the best with high probability. The proposed approach is validated with two practical distribution systems, TPC 84 node test system. The results are compared with Optimal Flow Pattern (OFP), Common Genetic Algorithm (CGA), Partheno Genetic Algorithm with Tree Structure Encoding technology (TSE‐PGA) and Second‐Order Cone Programming (SOCP).
Detection and classification of disturbances in the islanded micro‐grid by using wavelet transformation and feature extraction algorithm
Authors: Wang Yunqi , Raza Ahmed , Mohammed Faisal Parvez , Ravishankar Jayashri , Phung Toan
Published: June 2019

Digital signal processing (DSP) methods have been used by many researchers for detection and classification of transient disturbances because of their fast and powerful abilities to recognise waveform distortions. However, some DSP methods such as the wavelet transformation (WT) show less accuracy when applied to noisy real data. In this study, disturbance features are extracted in the wavelet domain based on the WT levels. Moreover, a new feature extraction algorithm namely normalised Renyi entropy with the signal energy is applied. This algorithm has been proven to be effective and robust for noisy signals. However, their application in power systems has not yet been tested. Using a laboratory setup of an islanded micro‐grid, experimental results validate the efficacy of the wavelet‐based normalised Renyi entropy in the detection and classification of four disturbance types (voltage sag, interruption, harmonics, mixture of harmonics and sag).
Analysis of the impacts of wind power forecast error on power system operation
Authors: Jiang Yamin , Preece Robin
Published: June 2019

With increasing penetration of renewable energy resources, the uncertain nature of these intermittent resources can introduce power dispatch problems resulting in serious risks to power system operational performance and reliability. Wind generation forecasts are crucial for power system scheduling and operation. In this study, a probabilistic method is proposed to assess the effects that wind generation forecast errors have on the dispatched power flow following short‐term wind generation forecasts. Case studies have been conducted using a 29‐bus reduced order model of the Great Britain power system under different scenarios. It is shown that the translation of wind plant forecast errors to errors in dispatched wind forecasts is non‐linear at high penetration levels.
Impact of photovoltaic systems on voltage stability in islanded distribution networks
Authors: Sinder Rebecca Laginestra , Assis Tatiana Mariano Lessa , Taranto Glauco Nery
Published: June 2019

This work analyses the impact of photovoltaic generation on voltage stability margin in an islanded microgrid. An indicator of voltage collapse proximity, based on the maximum deliverable power, is used to study the contribution of photovoltaic generation to the voltage stability margin. In this context, the well‐known power–voltage curves, also known as ‘nose’ curves, are developed, taking into account different levels of photovoltaic penetration. Furthermore, the effect of the power factor at the photovoltaic generators as well as the influence of the adopted model for such generators are also investigated. The results have shown that the photovoltaic generation can significantly affect the voltage stability margin.
Low power millimeter wave radar system for the visually impaired
Authors: Long Ningbo , Wang Kaiwei , Cheng Ruiqi , Hu Weijian , Yang Kailun
Published: June 2019

In order to help visually impaired people to avoid obstacles, a K‐band millimetre wave (MMW) radar system based on the principle of frequency‐modulated continuous wave (FMCW) is proposed in this study. The FMCW basic principle and the signal processing algorithm are elaborated in detail. The prototype of the radar system has been designed and manufactured. The experiment results show the qualified detection accuracy in view of low deviation. The maximum deviations from the range measurement experiments for a person and a car are 0.14 and 0.47 m, respectively. As a wearable system, the radar system has the characteristics of low power and small size, which is very suitable for blind navigation application. In addition, the MMW radar has broad application prospects in the field of automotive blind spot detection and small robots.
Third‐order harmonic currents suppression method based on selective component compensation for cascadedH‐bridge STATCOM under asymmetric grid
Authors: Lu Daorong , Hu Haibing
Published: June 2019

To achievelow cost and compactness, small dc capacitance in dc‐link is preferred in the cascaded H‐bridge (CHB) static synchronous compensator (STATCOM). However, small dc capacitance will definitely result in high dc‐link ripples among three clusters, and thus cause severe third‐order harmonic currents under the asymmetric grid. In this study, to mitigate the third‐order harmonic currents, a selective component compensation approach for the CHB STATCOM is proposed. To study the effect of the dc‐link ripples on the phase currents, sequence component decomposition is employed to derive the relationship between the dc‐link ripples and the converter voltages. The relationship reveals that the converter voltages contain positive, negative, and zero sequence components in both fundamental and third‐order under the asymmetric grid, while only the positive and negative sequence components in third‐order converter voltages result in third‐order harmonic currents due to the three‐wire system. Therefore, the third‐order harmonic currents suppression method is proposed by only compensating the positive and negative components in third‐order converter voltages. A 380 V/15 kVA STATCOM prototype is built to verify the proposed control method.
Target localisation in multistatic radar using BR, TDOA, and AOA measurements
Authors: Wang Jun , Qin Zhaotao , Bi Yanxian , Wei Shaoming , Luo Feixiang
Published: June 2019

This study investigates the target localisation problem by using the hybrid bistatic range (BR), time difference of arrival, and angle of arrival (AOA) measurements in multistatic passive radar. An explicit algebraic solution is developed by linearising the non‐linear measurement equations through introducing multiple nuisance parameters in the first stage and estimating the localisation error of the first stage solution to refine the final target position estimate in the second stage. The closed‐form resulting estimator has attractive computational complexity. Theoretical analysis of the proposed method is presented, and it is shown to be able to reach the Cramer–Rao lower bound at low noise levels. Simulations are included to validate the performance of the proposed estimator.
Superpixel cosegmentation algorithm for synthetic aperture radar image change detection
Authors: Shao Ningyuan , Zou Huanxin , Chen Cheng , Li Meilin , Sun Jiachi , Qin Xianxiang
Published: June 2019

Image segmentation has gained increasing popularity and has been widely applied in various image processing tasks recently. A simple linear iterative clustering (SLIC) superpixel generating algorithm for optical images based on k ‐means clustering approach works well in terms of computational simplicity and segmentation speed. However, due to the inherent speckle noise, it may generate poor segmentations for synthetic aperture radar (SAR) images. In this paper, an improved similarity measure combining pixel intensity and location similarity with edge information is utilised to replace the Euclidean distance in CIELAB colour space for performing local clustering to generate superpixels by using SLIC. Additionally, a constructed image is used to perform the superpixel cosegmentation, simultaneously segmenting the SAR image pairs. The generated superpixels can be taken as basic units for the subsequent change detection. The experimental results conducted on one simulated dataset and one real‐world SAR dataset demonstrate the feasibility and effectiveness of the proposed algorithm.
Boenninghausen's Therapeutic Pocket Book and Musculoskeletal Pain
Authors: Katarmal Daisy
Published: June 2019

This paper intends to throw light on Boenninghausen's method and his less often used repertory: Boenninghausen's Therapeutic Pocket Book. This is one of the first repertories and is considered an authentic work of Boenninghausen. However, Therapeutic Pocket Book is less used in practice because of certain points of criticisms; an attempt has been made to give a rationale for these points. Another point of controversy is discussed that may be frequently encountered in practice: whether to consider the disease pathology or solely depends on the totality of symptoms to work out a case homeopathically. The practical use of Therapeutic Pocket Book has been illustrated with a study in which it is observed that the homoeopathic treatment done using Boenninghausen's method is able to reduce the intensity of pain in patients with musculoskeletal pain.