bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibiting the NLRP3 inflammasome with MCC950 ameliorates retinal neovascularization and leakage by reversing the IL-1β/IL-18 activation pattern in an oxygen-induced ischemic retinopathy mouse model
Authors: Sui Ailing , Chen Xiuping , Shen Jikui , Demetriades Anna M. , Yao Yiyun , Yao Yixuan , Zhu Yanji , Shen Xi , Xie Bing
Published: October 2020

Activation of the nucleotide-binding domain leucine-rich repeat and pyrin domain containing receptor 3 (NLRP3) inflammasome plays an important role in ocular neovascularization. In our study, we found that the expression and activation levels of NLRP3 inflammasome components, including NLRP3, an apoptosis-associated speck-like protein (ASC) containing caspase activation and recruitment domain (CARD) and caspase-1 (CAS1), were significantly upregulated. In addition, we found interleukin (IL)-1βactivity increased while IL-18 activity decreased in the retinas of oxygen-induced ischemic retinopathy (OIR) mice. MCC950, an inhibitor of NLRP3, reversed the IL-1β/IL-18 activation pattern, inhibited the formation of retinal neovascularization (RNV), decreased the number of acellular capillaries and reduced leakage of retinal vessels. Moreover, MCC950 could regulate the expression of endothelial cell- and pericyte function-associated molecules, such as vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)1, VEGFR2, matrix metalloproteinase (MMP)2, MMP9, tissue inhibitor of metalloproteinases (TIMP)1, TIMP2, platelet-derived growth factor receptor-β(PDGFR-β), platelet-derived growth factor-B (PDGF-B), and angiopoietin2 (Ang2). In vitro, recombinant human (r)IL-18 and rIL-1βregulated the expression of endothelial cell- and pericyte function-associated molecules and the proliferation and migration of endothelial cells and pericytes. We therefore determined that inhibiting the NLRP3 inflammasome with MCC950 can regulate the function of endothelial cells and pericytes by reversing the IL-1β/IL-18 activation pattern to ameliorate RNV and leakage; thereby opening new avenues to treat RNV-associated ocular diseases.
Applying species distribution models in public health research by predicting snakebite risk using venomous snakes’ habitat suitability as an indicating factor
Authors: Yousefi Masoud , Kafash Anooshe , Khani Ali , Nabati Nima
Published: October 2020

Snakebite envenoming is an important public health problem in Iran, despite its risk not being quantified. This study aims to use venomous snakes’ habitat suitability as an indicator of snakebite risk, to identify high-priority areas for snakebite management across the country. Thus, an ensemble approach using five distribution modelling methods: Generalized Boosted Models, Generalized Additive Models, Maximum Entropy Modelling, Generalized Linear Models, and Random Forest was applied to produce a spatial snakebite risk model for Iran. To achieve this, four venomous snakes’ habitat suitability (Macrovipera lebetinus,Echis carinatus,Pseudocerastes persicusandNaja oxiana) were modelled and then multiplied. These medically important snakes are responsible for the most snakebite incidents in Iran. Multiplying habitat suitability models of the four snakes showed that the northeast of Iran (west of Khorasan-e-Razavi province) has the highest snakebite risk in the country. In addition, villages that were at risk of envenoming from the four snakes were identified. Results revealed that 51,112 villages are at risk of envenoming fromM.lebetinus, 30,339 fromE.carinatus, 51,657 fromP.persicusand 12,124 fromN.oxiana. Precipitation seasonality was identified as the most important variable influencing distribution of theP. persicus,E. carinatusandM. lebetinusin Iran. Precipitation of the driest quarter was the most important predictor of suitable habitats of theN. oxiana. Since climatic variables play an important role in shaping the distribution of the four venomous snakes in Iran, thus their distribution may alter with changing climate. This paper demonstrates application of species distribution modelling in public health research and identified potential snakebite risk areas in Iran by using venomous snakes’ habitat suitability models as an indicating factor. Results of this study can be used in snakebite and human–snake conflict management in Iran. We recommend increasing public awareness of snakebite envenoming and education of local people in areas which identified with the highest snakebite risk.
Author Correction: Disruption of SHH signaling cascade by SBE attenuates lung cancer progression and sensitizes DDP treatment
Authors: Du Jing , Chen Weiwei , Yang Lijuan , Dai Juanjuan , Guo Jiwei , Wu Yan , Gong Kaikai , Zhang Jian , Yu Ning , Xie Zhen , Xi Sichuan
Published: October 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Serum adipokines as non-invasive biomarkers in Crohn’s disease
Authors: Ortega Moreno Lorena , Sanz-Garcia Ancor , Fernández de la Fuente Marina J. , Arroyo Solera Ricardo , Fernández-Tomé Samuel , Marin Alicia C. , Mora-Gutierrez Irene , Fernández Paloma , Baldan-Martin Montserrat , Chaparro María , Gisbert Javier P. , Bernardo David
Published: October 2020

Adipose tissue secretes molecules that can promote activity in Crohn’s disease. We aimed to evaluate the role of serum adipokines as possible biomarkers in Crohn’s disease. Serum samples were obtained from 40 patients with endoscopically active or quiescent Crohn’s disease and 36 healthy controls. Serum leptin, ghrelin, resistin and adiponectin levels were analysed by Multiplex in a Luminex 200 system technology. Receiver Operating Characteristic curves were performed to evaluate the adipokines discriminatory capacity. A logistic regression adjusted by possible confounders (i.e. gender, age, BMI) was performed for those adipokines that showed an area under the curve > 0.7. No differences were found in age, gender or BMI among groups. Distribution for serum resistin was different among the three groups of study, and only this adipokine showed an area under the curve of 0.75 comparing actives patients and healthy control groups. Resistin median concentration was selected as a cut-off for a logistic regression analysis; odds ratio along its 95% confidence interval adjusted by gender, age, and BMI yielded a value of 5.46 (1.34–22.14) comparing actives patients and healthy controls. High concentration of serum resistin is probably associated to activity, being this association independent of gender, age or BMI.
Survival is reduced when endogenous period deviates from 24 h in a non-human primate, supporting the circadian resonance theory
Authors: Hozer Clara , Perret Martine , Pavard Samuel , Pifferi Fabien
Published: October 2020

Circadian rhythms are ubiquitous attributes across living organisms and allow the coordination of internal biological functions with optimal phases of the environment, suggesting a significant adaptive advantage. The endogenous period called tau lies close to 24 h and is thought to be implicated in individuals’ fitness: according to the circadian resonance theory, fitness is reduced when tau gets far from 24 h. In this study, we measured the endogenous period of 142 mouse lemurs (Microcebus murinus), and analyzed how it is related to their survival. We found different effects according to sex and season. No impact of tau on mortality was found in females. However, in males, the deviation of tau from 24 h substantially correlates with an increase in mortality, particularly during the inactive season (winter). These results, comparable to other observations in mice or drosophila, show that captive gray mouse lemurs enjoy better fitness when their circadian period closely matches the environmental periodicity. In addition to their deep implications in health and aging research, these results raise further ecological and evolutionary issues regarding the relationships between fitness and circadian clock.
Genome-wide identification of AP2/ERF transcription factor-encoding genes in California poppy (Eschscholzia californica) and their expression profiles in response to methyl jasmonate
Authors: Yamada Yasuyuki , Nishida Shohei , Shitan Nobukazu , Sato Fumihiko
Published: October 2020

With respect to the biosynthesis of plant alkaloids, that of benzylisoquinoline alkaloids (BIAs) has been the most investigated at the molecular level. Previous investigations have shown that the biosynthesis of BIAs is comprehensively regulated by WRKY and bHLH transcription factors, while promoter analyses of biosynthesis enzyme-encoding genes have also implicated the involvement of members of the APETALA2/ethylene responsive factor (AP2/ERF) superfamily. To investigate the physiological roles of AP2/ERF transcription factors in BIA biosynthesis, 134 AP2/ERF genes were annotated using the draft genome sequence data of Eschscholzia californica (California poppy) together with transcriptomic data. Phylogenetic analysis revealed that these genes could be classified into 20 AP2, 5 RAV, 47 DREB, 60 ERF and 2 Soloist family members. Gene structure, conserved motif and orthologous analyses were also carried out. Gene expression profiling via RNA sequencing in response to methyl jasmonate (MeJA) indicated that approximately 20 EcAP2/ERF genes, including 10 group IX genes, were upregulated by MeJA, with an increase in the expression of the transcription factor-encoding gene EcbHLH1 and the biosynthesis enzyme-encoding genes Ec6OMT and EcCYP719A5. Further quantitative RT-PCR confirmed the MeJA responsiveness of the EcAP2/ERF genes, i.e., the increased expression of 9 group IX, 2 group X and 2 group III ERF subfamily genes. Transactivation activity of group IX EcAP2/ERFs was also confirmed by a luciferase reporter assay in conjunction with the promoters of the Ec6OMT and EcCYP719A5 genes. The physiological roles of AP2/ERF genes in BIA biosynthesis and their evolution in the regulation of alkaloid biosynthesis are discussed.
Homocysteine level is positively and independently associated with serum creatinine and urea nitrogen levels in old male patients with hypertension
Authors: Yang Qianhong , Lu Youwei , Deng Yanhua , Xu Jiayi , Zhang Xi
Published: October 2020

A cross-sectional study to show whether and how serum fasting homocysteine levels are associated with renal function changes in patients with hypertension. Homocysteine levels were associated with serum creatinine and blood urea nitrogen (BUN) levels with coefficients of 2.04 and 0.07, respectively, only in males and independent of confounders. In addition, low density lipoprotein cholesterol (LDL-C) levels were positively and left ventricular ejection fraction (LVEF) was negatively associated with serum creatinine level in males; age was positively associated with serum creatinine levels in females. Age was a common risk factor positively associated with BUN levels in both sexes, while total cholesterol (TC) levels and glycemic control were independent risk factors that were positively associated with BUN levels only in males. LDL-C levels and LVEF were negatively associated with BUN levels in females. Body mass index (BMI) was positively associated and hemoglobin A1c (HbA1c) levels, high density lipoprotein cholesterol (HDL-C) levels and the presence of stroke were negatively associated with serum uric acid levels in male patients. In contrast, only LVEF was positively associated with uric acid levels in females. In conclusion, homocysteine level is an independent risk factor associated with serum creatinine and BUN levels in male patients with hypertension.
Survive or swim: different relationships between migration potential and larval size in three sympatric Mediterranean octocorals
Authors: Guizien Katell , Viladrich N. , Martínez-Quintana Á. , Bramanti L.
Published: October 2020

Knowledge about migration potential is key to forecasting species distributions in changing environments. For many marine benthic invertebrates, migration happens during reproduction because of larval dispersal. The present study aims to test whether larval size can be used as a surrogate for migration potential arising from larval longevity, competence, sinking, or swimming behavior. The hypothesis was tested using larvae of three sympatric gorgonian species that release brooded lecithotrophic larvae in the same season: Paramuricea clavata, Corallium rubrum and Eunicella singularis. Despite different fecundities and larval sizes, the median larval longevity was similar among the three species. Free-fall speed increased with larval size. Nevertheless, the only net sinkers were the P. clavata larvae, as swimming was more common than free fall in the other two species with larger larvae. For the other two species, swimming activity frequency decreased as larval size increased. Interestingly, maximum larval longevity was lowest for the most active but intermediately sized larvae. Larval size did not covary consistently with any larval traits of the three species when considered individually. We thus advise not using larval size as a surrogate for migration potential in distribution models. The three species exemplified that different mechanisms, i.e., swimming activity or larval longevity, resulting from a trade-off in the use of energy reserves can facilitate migration, regardless of life history strategy.
Effects of age on pregnancy outcomes in patients with simple tubal factor infertility receiving frozen-thawed embryo transfer
Authors: Sun Yi-Fei , Zhang Jie , Xu Yue-Ming , Luo Zhuo-Ye , Sun Yong , Hao Gui-Min , Gao Bu-Lang
Published: October 2020

This study was to retrospectively analyze the effect of the age of embryos transfer and oocyte retrieval on the clinical pregnancy outcome in patients with simple tubal factor infertility (TFI) who received frozen-thawed embryo transfer. Patients (n = 3619) with simple TFI who underwent in vitro fertilization (IVF)/ intracytoplasmic sperm injection (ICSI) frozen-thawed embryo transfer at our hospital were enrolled. Univariate logistic regression analysis, categorical multivariate logistic regression analysis, curve fitting and threshold effect analysis were performed. Age of embryo transfer was a significant (P < 0.05) independent risk factor affecting the clinical pregnancy, live birth, and miscarriage rates. The Clinical pregnancy outcome declined significantly after the age of 34 years. After limiting the female oocyte retrieval age to ≤ 34 years, no significant change was detected in the clinical pregnancy, live birth, or miscarriage rate with increase of transplantation age. In conclusion, in patients with simple TFI undergoing IVF/ICSI frozen-thawed embryo transfer, age is a significant independent risk factor affecting the clinical pregnancy, live birth, and miscarriage rate. Aging of oocytes has a greater impact on the clinical pregnancy in women with simple TFI than the aging of the body. Patients with TFI can freeze embryos in advance to preserve fertility.
Comparing the diagnostic concordance of tele-EMS and on-site-EMS physicians in emergency medical services: a retrospective cohort study
Authors: Quadflieg Lina T. M. , Beckers Stefan K. , Bergrath Sebastian , Brockert Ann-Katrin , Schröder Hanna , Sommer Anja , Brokmann Jörg C. , Rossaint Rolf , Felzen Marc
Published: October 2020

In 2014, a telemedicine system was established in 24-h routine use in the emergency medical service (EMS) of the city of Aachen. This study tested whether the diagnostic concordance of the tele-EMS physician reaches the same diagnostic concordance as the on-site-EMS physician. The initial prehospital diagnoses were compared to the final hospital diagnoses. Data were recorded retrospectively from the physicians’ protocols as well as from the hospital administration system and compared. Also, all diagnostic misconcordance were analysed and reviewed in terms of logical content by two experts. There were no significant differences between the groups in terms of demographic data, such as age and gender, as well as regarding the hospital length of stay and mortality. There was no significant difference between the diagnostic concordance of the systems, except the diagnosis “epileptic seizure”. Instead, in these cases, “stroke” was the most frequently chosen diagnosis. The diagnostic misconcordance “stroke” is not associated with any risks to patients’ safety. Reasons for diagnostic misconcordance could be the short contact time to the patient during the teleconsultation, the lack of personal examination of the patient by the tele-EMS physician, and reversible symptoms that can mask the correct diagnosis.
Compact folded dipole metasurface for high anomalous reflection angles with low harmonic levels
Authors: Islam Nasim Al , Choi Sangjo
Published: October 2020

A dense unit cell array used in a metasurface for a high reflection angle (θr > 50°) leads to high coupling among the unit cells; thus, parasitic reflections are unavoidable. The up-do-date patch-based metasurfaces for high reflection angles were electrically large (> 80 λ2), but for a practical point of view, a more compact metasurface design is needed. As a solution for these issues, we use the folded dipole-based unit cells with closed-loop currents for low near-field coupling and design compact metasurfaces (~ 40 λ2) for high reflection angles (θr = 56° and 70°) at 10 GHz. The folded dipole unit cells are arranged according to the recently developed non-linear phase boundary condition for low harmonic reflections. As a counterpart, we also designed a metasurface using conventional patch-shaped unit cells with the same reflection phases (θr = 70°). In experiments, the folded dipole metasurface shows lower harmonic levels (θr = 0° and − 70°) and a comparable anomalous reflection (θr = 70°) versus the patch-shaped metasurface. The time-domain analysis demonstrates that the low harmonic levels from the folded dipole metasurface are due to low scattering from the guided waves and the edge scattering. The proposed compact folded dipole-based metasurface with low undesired harmonics can be used as a practical reflect-array for millimeter-wave communication links.
Publisher Correction: Sex dependent effects of post-natal penicillin on brain, behavior and immune regulation are prevented by concurrent probiotic treatment
Authors: Kayyal Marya , Javkar Tanvi , Firoz Mian M. , Binyamin Dana , Koren Omry , McVey Neufeld Karen-Anne , Forsythe Paul
Published: October 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Carbapenems drive the collateral resistance to ceftaroline in cystic fibrosis patients with MRSA
Authors: Varela Maria Celeste , Roch Melanie , Taglialegna Agustina , Long Scott W. , Saavedra Matthew Ojeda , Rose Warren E. , Davis James J. , Hoffman Lucas R. , Hernandez Rafael E. , Rosato Roberto R. , Rosato Adriana E.
Published: October 2020

Chronic airways infection with methicillin-resistant Staphylococcus aureus (MRSA) is associated with worse respiratory disease cystic fibrosis (CF) patients. Ceftaroline is a cephalosporin that inhibits the penicillin-binding protein (PBP2a) uniquely produced by MRSA. We analyzed 335 S. aureus isolates from CF sputum samples collected at three US centers between 2015–2018. Molecular relationships demonstrated that high-level resistance of preceding isolates to carbapenems were associated with subsequent isolation of ceftaroline resistant CF MRSA. In vitro evolution experiments showed that pre-exposure of CF MRSA to meropenem with further selection with ceftaroline implied mutations in mecA and additional mutations in pbp1 and pbp2, targets of carbapenems; no effects were achieved by other β-lactams. An in vivo pneumonia mouse model showed the potential therapeutic efficacy of ceftaroline/meropenem combination against ceftaroline-resistant CF MRSA infections. Thus, the present findings highlight risk factors and potential therapeutic strategies offering an opportunity to both prevent and address antibiotic resistance in this patient population.
Environmental and microbial controls on microbial necromass recycling, an important precursor for soil carbon stabilization
Authors: Buckeridge Kate M. , Mason Kelly E. , McNamara Niall P. , Ostle Nick , Puissant Jeremy , Goodall Tim , Griffiths Robert I. , Stott Andrew W. , Whitaker Jeanette
Published: October 2020

There is an emerging consensus that microbial necromass carbon is the primary constituent of stable soil carbon, yet the controls on the stabilization process are unknown. Prior to stabilization, microbial necromass may be recycled by the microbial community. We propose that the efficiency of this recycling is a critical determinant of soil carbon stabilization rates. Here we explore the controls on necromass recycling efficiency in 27 UK grassland soils using stable isotope tracing and indicator species analysis. We found that recycling efficiency was unaffected by land management. Instead, recycling efficiency increased with microbial growth rate on necromass, and was highest in soils with low historical precipitation. We identified bacterial and fungal indicators of necromass recycling efficiency, which could be used to clarify soil carbon stabilization mechanisms. We conclude that environmental and microbial controls have a strong influence on necromass recycling, and suggest that this, in turn, influences soil carbon stabilization.
Nickel – p-block metal mixed chalcogenides based on AuCu3-type fragments: iodine-assisted synthesis as a way of obtaining new structures
Authors: Stroganova Ekaterina A. , Kazakov Sergey M. , Efimov Nikolay N. , Khrustalev Victor N. , Keilholz Simon , Götze Andre , Kohlmann Holger , Kuznetsov Alexey N.
Published: October 2020

Three new mixed nickel-rich chalcogenides, Ni9.39Ga2S2, Ni5.80GaTe2, and Ni5.78InTe2, have been synthesized by a high-temperature route with the addition of iodine, and characterized by X-ray diffraction, DFT calculations, and magnetic measurements.
Controllable synthesis of nitrogen-doped carbon nanobubbles to realize high-performance lithium and sodium storage
Authors: Sun Lin , Xie Jie , Zhang Xixi , Zhang Lei , Wu Jun , Shao Rong , Jiang Ruiyu , Jin Zhong
Published: October 2020

Carbon nanobubbles are regarded as one of the most promising carbon-based anode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), with significantly improved capacity and superior cycling stability.
Core–shell nano/microstructures for heterogeneous tandem catalysis
Authors: Wang Zijian , Qi Jian , Yang Nailiang , Yu Ranbo , Wang Dan
Published: October 2020

The three basic factors in designing an excellent core–shell heterogeneous tandem catalyst, including sequencing, proximity and compatibility of different catalytic sites, are systematically summarized and discussed.
MXenes: promising donor and acceptor materials for high-efficiency heterostructure solar cells
Authors: Zhang Yinggan , Xiong Rui , Sa Baisheng , Zhou Jian , Sun Zhimei
Published: October 2020

Searching for feasible photovoltaic materials from MXenes. Ti2CO2/Zr2CO2 (Hf2CO2) heterostructure solar cells exhibit remarkable absorbance and high PCEs.
Aggregation propensity of therapeutic fibrin-homing pentapeptides: insights from experiments and molecular dynamics simulations
Authors: Zanuy David , Puiggalí-Jou Anna , Conflitti Paolo , Bocchinfuso Gianfranco , Palleschi Antonio , Alemán Carlos
Published: October 2020

CREKA (Cys–Arg–Glu–Lys–Ala) and its engineered analogue CRMeEKA, (N-methyl-Glu instead of Glu), are emerging pentapeptides that were specifically designed to bind fibrin–fibronectin complexes accumulated in the walls of tumour vessels.
A surfactant reaction model for the reciprocating motion of a self-propelled droplet
Authors: Tanaka Shinpei , Nakata Satoshi , Nagayama Masaharu
Published: October 2020

We report herein experimental observations of the reciprocating motion of a self-propelled droplet floating on the surface of an aqueous surfactant solution and a simple reaction model capable of reproducing the observed behavior of the droplet.
Correction: Investigating the electroactivity of nitrogen species in MoC nanoparticles/N-doped carbon nanosheets for high-performance Na/Li-ion batteries
Authors: Wu Qing , Li Xiaofeng , Wang Xianjie , Yao Tai , Bai Ying , Jian Jikang , Song Bo
Published: October 2020

Correction for ‘Investigating the electroactivity of nitrogen species in MoC nanoparticles/N-doped carbon nanosheets for high-performance Na/Li-ion batteries’ by Qing Wu et al., J. Mater. Chem. A, 2020, DOI: 10.1039/d0ta08301a.
Data privacy‐based coordinated placement method of workflows and data
Authors: Huang Tao , Xue Shengjun , Hu Yumei , Shi Yiran , Jin Wei
Published: October 2020

With the rapid development of data acquisition technology, many industries data already have the characteristics of big data and cloud technology has provided strong support for the storage and complex calculations of these massive data. The meteorological department established the cloud data centre based on the existing storage and computing resources and re‐arranged the historical data to reduce the historical data access time of applications. However, the placement of each workflow and input data also affects the average data access time, which in turn affects the computing efficiency of the cloud data centre. At the same time, because of the collaborative processing of multiple nodes, the resource utilisation of cloud data centre has also been paid more and more attention. In addition, with the increase of data security requirements, some privacy conflict data should avoid being placed on the same or neighbouring nodes. In response to this challenge, based on the fat‐tree network topology, this study proposes a data privacy protection‐based collaborative placement strategy of workflow and data to jointly optimise the average data access time, the average resource utilisation, and the data conflict degree. Finally, a large number of experimental evaluations and comparative analyses verify the efficiency of the proposed method.
Unified Smith predictor‐based loop‐shaping H∞ damping controller for mitigating inter‐area oscillations in power system
Authors: Sarkar Mithu , Subudhi Bidyadhar
Published: October 2020

Low‐frequency inter‐area oscillation is one of the major problems to transfer the bulk power from one area to another area in an interconnected large power system. A wide‐area signal‐based controller is more effective to improve the damping of the inter‐area oscillation than a local area signal‐based controller. A wide‐area measurement system makes it easier to transmit the wide‐area signal through the communication system from the remote location to the controller site. However, the involvement of the unavoidable time delay in the wide‐area signal transmission from a remote area to a controller site is to possess a great deal of challenge to design a damping controller. In this study, a unified Smith predictor (USP)‐based loop shaping controller is designed to handle the negative effect of the delay using the wide‐area signal. The robust stabilization normalised co‐prime factor problem is converted into a generalised H ∞ optimisation problem for additional pole placement constraints. The performances of the USP‐based loop‐shaping H ∞ controller are compared with the USP‐based H ∞ controller. From the obtained results, it is verified that the proposed controller gives an excellent damping performance and handles the effect of time delay.
Design and implementation of an LCL grid‐connected inverter based on capacitive current fractional proportional–integral feedback strategy
Authors: Wang Qingyi , Ju Binlei , Zhang Yiqiong , Zhou Dan , Wang Nan , Wu Genping
Published: October 2020

The capacitive current feedback active damping strategy has a limited damping region. When the grid‐side impedance is large, the digital control inductor–capacitor–inductor (LCL) grid‐connected inverter system with grid‐side current loop control and capacitive current feedback active damping cannot run stably. To address this issue, this study proposes an improved capacitive current feedback active damping strategy, namely the capacitive current fractional proportional–integral feedback strategy (CCFPIFS), which increases the upper‐frequency limit of the system damping region and approaches to the Nyquist sampling frequency. Furthermore, this study analyses the constraints of fractional‐order proportional–integral controller parameters to ensure the stability of the system. The simulation analysis is performed by Simulink. The experimental results are consistent with theoretical expectations. Consequently, the proposed CCFPIFS can not only achieve better control performance and improve the robustness of the LCL grid‐connected inverter system, but also improve the output power quality of the system. This damping strategy can make the LCL grid‐connected inverter system work stably under the environment of high grid impedance.
Effect of mineral oil on flashover voltage of HTV silicone rubber under AC corona ageing: from the view of trap level distribution
Authors: Yu Yu , Wang Ke , Yang Yan , Li Gang , Wu Guangning , Li Jinzhong , Gao Bo
Published: October 2020

The flashover voltage of high temperature vulcanised (HTV) silicone rubber will be decreased after corona ageing, and it further decreases under the effect of mineral oil. The mechanisms for the phenomena can be explained by considering the role of trap level distribution. In this study, the corona ageing of silicone rubber was conducted and the flashover voltage was tested. The isothermal surface potential decay was tested to explore the internal relationship between trap distribution and flashover voltage. Besides, the surface microtopography and chemical structure of silicone rubber were gained by scanning electron microscopy and Fourier infrared spectroscopy to explain the change of trap distribution. The test results show that the flashover voltage of HTV silicone rubber decreases with AC corona ageing time, the reduction of flashover voltage for an oil‐impregnated sample is more serious. The density of shallow electron traps increases at first and then decreases, while the density of shallow hole traps increases with ageing time. The density of deep traps decreases after corona ageing. These trap level distribution characteristics are beneficial to promote the development of flashover, leading to lower flashover voltage. The effect of mineral oil can be regarded as an accelerated ageing effect.
Partial discharge direction‐of‐arrival estimation in air‐insulated substation by UHF wireless array and RSSI maximum likelihood estimator
Authors: Han Bei , Luo Lingen , Sheng Gehao , Jiang Xiuchen
Published: October 2020

The quick detection and localisation of partial discharge (PD) in an air‐insulated substation (AIS) based on ultrahigh‐frequency (UHF) sensor arrays are efficient for power equipment monitoring. The adopted UHF PD time difference‐of‐arrival (DOA) methods mainly use the time difference of electromagnetic wave signals. Thus, the system requires both a high‐sampling rate and time synchronisation accuracy, leading to a high cost and large size. In this study, the feasibility and accuracy of PD DOA in an AIS were investigated using an UHF wireless sensor array and the received signal strength indicator. First, the power pattern of the designed UHF wireless sensor array was obtained via an offline experiment. Then, a statistical approach to the PD DOA method based on the maximum likelihood estimator was employed to obtain the preliminary DOA result. Finally, interpolation and clustering algorithms were used to improve the accuracy of the DOA. A laboratory test was conducted. The average error of the PD DOA was <6°, and the cost‐effectiveness and portability were clearly improved.
Multi‐objective optimal provision of fast frequency response from EV clusters
Authors: Sanchez Gorostiza Francisco , Gonzalez‐Longatt Francisco , Rueda José Luis
Published: October 2020

Declining levels of rotational inertia in modern power systems prompt transmission system operators (TSOs) to develop novel ways of maintaining the balance between generation and demand. Services such as fast frequency response (FFR) can help the TSO achieve this balance. The growing penetration of electric vehicles (EVs) promotes the provision of FFR from clusters of EVs. Fast charging stations are more geared towards destination charging, whereas slow charging stations are more attractive as providers of FFR, given the longer connection times. In this study, the provision of FFR from EV clusters is formulated as a multi‐objective optimisation problem with network security constraints and two minimisation objectives, i.e. the maximum frequency deviation following a disturbance and the energy provided by public EV charging stations. A methodology was developed to solve the optimisation problem with a variant of the non‐dominated sorting genetic algorithm. This methodology allows the decision‐maker to consider trade‐offs among the objectives, leading to a more informed decision. An enhanced frequency‐responsive aggregate model of an EV cluster was developed to study the provision of FFR in a multi‐area power system. A reduced model of the Nordic power system was used to illustrate the performance of the proposed methodology.
Impact of STATCOM and BFCL on the performance of distance relay and its improvement by adaptive setting for grid‐interactive offshore wind and marine current farm
Authors: Kushwaha Satendra Kumar Singh , Mohanty Soumya Ranjan , Samuel Paulson
Published: October 2020

This study explores the impact of the dynamic impedance of static synchronous compensator (STATCOM) and bridge type fault current limiter (BFCL) on the performance of distance relay and its improvement by adaptive setting for Grid Interactive Offshore Wind and Marine‐Current Farm. For assessments, analytical results are presented under different STATCOM settings, low voltage ride through (LVRT) condition, and different types of fault conditions. Moreover, the presence of STATCOM and BFCL significantly changes the apparent impedance characteristic of the studied system. It is also seen that the presence of STATCOM likely to induce an under reach and overreach problem of distance relay. Further, the LVRT capability is significantly affected as STATCOM supplies reactive power to offshore wind generators during a short circuit on the grid side. It is found that the grid integration of OWF and MCF with STATCOM and BFCL is likely to induce mis‐coordination and subsequently deteriorate the performance of distance relay, leading to system security problems. Therefore, this study proposed an adaptive setting in order to eliminate the simultaneous influence upon the dynamic impedance due to incorporation of STATCOM and BFCL on the distance relay setting. The simulation results show the efficacy of the proposed adaptive setting.
Non‐isolated DC–DC converter with a high‐voltage conversion ratio
Authors: Shayeghi Hossein , Pourjafar Saeed , Maalandish Mohammad , Nouri Soheil
Published: October 2020

This work introduces a novel non‐isolated boost DC–DC converter with high‐voltage gain and high efficiency. The magnetic coupling and voltage lift circuit technique has been utilised to enhance the voltage conversion ratio. In order to decrease the peak voltage across the active switch, the voltage lift circuit acts as a clamp circuit. The zero current switching in the OFF‐state and the zero voltage switching in the ON‐state of diodes are other advantages of the suggested converter which leads to approach high efficiency by decreasing the conduction losses. In addition, only one power metal–oxide–semiconductor field‐effect transistor with lower ON‐state resistance is employed, which can provide the simple control circuit of the proposed topology. For demonstrating the performance of the proposed structure, the principle of operation modes and comparison results with other previous works is carried out. Finally, experimental results with a 200 W power level at 25 kHz operating frequency are prepared, which validate the usefulness of the proposed converter.
Surface plasmon resonance of silver nano‐dendrites improved light absorption in an organic photovoltaic active layer
Authors: Hamdan Khairus Syifa , Abdullah Shahino Mah , Talik Noor Azrina , Sulaiman Khaulah , Zakaria Rozalina
Published: October 2020

Surface plasmon resonance (SPR) or so‐called plamonics behaviour is well‐known for its tunability along the light absorption spectrum. Additionally, there are number of parameters alteration could be tuned to tailor the materials’ characteristics towards any special needs of the application. In this work, the authors report a novel metallic structure of silver nano‐dendrites (Ag NDs) fabricated using electrochemistry deposition technique. This Ag NDs was implemented in the active layer of an organic photovoltaic to increase the light absorption in the intrinsic layer. The optical properties’ behaviour of these structures depicts that smaller assemblies can provide prominent SPR properties which will enhance the light trapping mechanism in the active layer of organic solar cells. The incident light will be trapped more efficiently and scattered extensively within the cell layers with the presence of Ag NDs arrays. The ultraviolet–visible and photoluminescence spectra show that the presence of Ag NDs enhances the absorption of light inside the organic solar cells’ layer compared to the original solar cell. The amount of collective light absorption at the active layer of an organic photovoltaic is very important in improving the efficiency of the device.
Effect of sputtering pressure on the structure and properties of SiO2 films prepared by magnetron sputtering
Authors: Zhao Leran , Zhao Changjiang , Liu Juncheng , Liu Zhigang , Chen Yan
Published: October 2020

The effects of sputtering pressure on the O/Si ratio, microstructure, surface morphology and optical properties within 300–1100 nm of SiO2 film via radio frequency magnetron sputtering were investigated. The results showed that the molar ratio of O/Si in the film increased from 1.96 to 2.03, from silicon rich to oxygen rich, with the sputtering pressure increase from 0.3 to 1.3 Pa. The SiO2 films deposited at different pressure were all amorphous. There were many ditches with a length of about 50 nm on the surface of the film deposited at lower pressure. The increase of sputtering pressure could reduce the number of ditches, and make the surface denser and more uniform. The refractive index increased first, then decreased and finally increased with the increase of sputtering pressure, and the maximum and minimum values were obtained at 0.7 and 1.1 Pa, respectively. The change of absorptivity was approximately the same as that of the refractive index, while the change of the average transmittance of coated quartz glass was exactly the opposite of refractive index. The minimum value of the average transmittance 92.6% and the maximum value 93.1% were obtained at 0.7 and 1.1 Pa, respectively.
Hurricanes on tidally locked terrestrial planets: fixed surface temperature experiments
Authors: Yan Mingyu , Yang Jun
Published: October 2020

Aims.In this work, we study the presence of hurricanes on exoplanets. Tidally locked terrestrial planets around M dwarfs are the main targets of space missions looking to discover habitable exoplanets. The question of whether hurricanes can form on this kind of planet is important for determining their climate and habitability.

Methods.Using a high-resolution global atmospheric circulation model, we investigated whether there are hurricanes on tidally locked terrestrial planets under fixed surface temperatures (TS). The relevant effects of the planetary rotation rate, surface temperature, and bulk atmospheric compositions were examined.

Results.We find that hurricanes can form on the planets but not on all of them. For planets near the inner edge of the habitable zone of late M dwarfs, there are more numerous and stronger hurricanes on both day and night sides. For planets in the middle and outer ranges of the habitable zone, the possibility of hurricane formation is low or even close to zero, as has been suggested in recent studies. Earth-based hurricane theories are applicable to tidally locked planets only when the atmospheric compositions are similar to that of Earth. However, if the background atmosphere is lighter than H2O, hurricanes can hardly be produced because convection is always inhibited due to the effect of the mean molecular weight, similarly to the case of Saturn. These results have broad implications on the precipitation, ocean mixing, climate, and atmospheric characterization of tidally locked planets. Finally, A test with a coupled slab ocean and an Earth-like atmosphere in a tide-locked orbit of ten Earth days demonstrates that there are also hurricanes present in the experiment.
Numerical Model for the Analysis of Thermal Transients in District Heating Networks
Authors: Capone Martina , Guelpa Elisa , Verda Vittorio
Published: October 2020

As District Heating (DH) networks are experiencing an evolution towards the so-called 4th generation, there is a need to update the currently used models to take into account the ever-increasing complexity of this technology. Indeed, to further improve the reduction in energy consumption and carbon-dioxide emissions, a wide range of technologies and management strategies are being introduced within district heating, such as a large exploitation of Renewable Energy Sources (RES). As a consequence, thermal transients assume a major importance, posing the need to redefine the relevant physical parameters and to develop a model which accurately describes their behaviour. In this framework, this paper proposes a quantitative analysis of the influence of the pipe heat-capacity on the model. Moreover, an equivalent-model, which is able to take into account the two heat capacities of steel and water in just one equation, is proposed and compared with two commonly used approaches. One of the features of the proposed model is the suitability for application to large networks. To prove its capabilities, an application to the Turin district heating network, which is among the largest systems in Europe, is proposed. Results show significant improvements in terms of accuracy over computational time ratio.
Performance assessment of integrated energy systems for the production of renewable hydrogen energy carriers
Authors: Lonis Francesco , Tola Vittorio , Cau Giorgio
Published: October 2020

To guarantee a smooth transition to a clean and low-carbon society without abandoning all of a sudden liquid fuels and products derived from fossil resources, power-to-liquids processes can be used to exploit an excess of renewable energy, producing methanol and dimethyl ether (DME) from the conversion of hydrogen and recycled CO2. Such a system could behave as an energy storage system, and/or a source of fuels and chemicals for a variety of applications in several industrial sectors.

This paper concerns the conceptual design, performance analysis and comparison of small-scale decentralised integrated energy systems to produce methanol and DME from renewable hydrogen and captured CO2. Renewable hydrogen is produced exploiting excess RES. Water electrolysis is carried out considering two different technologies alternatively: commercially mature low temperature alkaline electrolysers (AEL) and innovative high temperature solid oxide electrolysers (SOEC). A first conversion of hydrogen and CO2 takes place in a catalytic reactor where methanol is synthesised through the hydrogenation process. Methanol is then purified in a distillation column. Depending on the final application, methanol can be further converted into DME through catalytic dehydration in another catalytic reactor. The chemical (either methanol or DME) is stored at ambient conditions and used as necessary.

To predict the performance of the main components and of the overall system, numerical simulation models were developed using the software Aspen Plus. The performance and efficiencies of each section and of the overall systems were evaluated through extensive mass and energy balances. Globally, the overall power-to-liquids efficiency was found to be above 0.55 for all the different configurations, both considering a powerto-methanol or a power-to-DME process.
Approaching the validation of building energy models: billing vs indoor environmental data
Authors: Palladino Domenico , Nardi Iole
Published: October 2020

To understand the real building energy consumption, and to identify the best energy improvements (due to energy refurbishment and/or HVAC replacement), the energy audit is recommended, but it generally entails the realization of an energy model of the building itself. The main issue of this approach is the collection of data, needed to verify the reliability of the energy audit results. Currently, to validate buildings energy model retrieved by hourly semi-stationary software, is it possible to refer to: (i) bills related to energy carrier (i.e. natural gas and/or electricity); (ii) monitored indoor parameters. The aim of the paper is to understand which of the two is more suitable for the purpose. In this work, the two options are investigated considering, as case study, a family house located in central Italy, whose envelope thermophysical properties and HVAC systems are known, and whose bills and indoor environmental conditions (air temperature and relative humidity) were archived since December 2019. Results from the two validation methods are very close to each other; particularly, results show that energy audit performed with indoor environmental parameters better fits the real consumption, but it entails more complex validation procedure.
Energy flexibility in Mediterranean buildings: a case-study in Sicily
Authors: Marotta Ilaria , Guarino Francesco , Cellura Maurizio , Longo Sonia
Published: October 2020

Since the building sector is responsible for 40% of the world’s electricity demand, it is essential to act on it in order to reduce emissions of climate change gases on a global scale, as expressed also in the latest directive on the energy performance of buildings. A design approach that focuses on the energy flexibility of buildings can contribute to the improvement of its energy-environmental performances. In this context, the objective of the study is the analysis of the energy performance of a residential building in Sicily and the definition of strategies aimed at increasing its energy flexibility. In particular, the case study is a 631 m2single-family house, modeled and simulated in TRNSYS environment. The approach involves the development of scenarios to reduce operating costs and CO2emissions during the use phase of the building. Rule Based Control algorithms are implemented. The flexible control reacts to a price or emission signal, by modulating the heating set-point accordingly. The results highlighted significant increases in energy flexibility. The economic algorithm achieves savings of 21.46%, accompanied by a 15% reduction in emissions. The environmental algorithm allows to reduce CO2 emissions by about 30%. The economic impact is positive, with a 17.58% reduction in costs.