bluuebunny/crossref_metadata_2025 huggingface dataset:
Simple discrimination in stingless bees (Melipona quadrifasciata): Probing for select‐ and reject‐stimulus control
Authors: Scienza Livia , de Carvalho Marilia Pinheiro , Machado Armando , Moreno Antonio Maurício , Biscassi Natália , de Souza Deisy das Graças
Published: June 2019

Simple and conditional discrimination training may produce various types of controlling relations. Responses may be controlled primarily by the positive stimulus (select–control relation) or by the negative stimulus (reject–control relation; the subject excludes the negative stimulus and chooses the positive). Bees learn to respond in simple and conditional discriminations. However, no study has searched for reject–control responding in Melipona bees. We trained Melipona quadrifasciata on a simple discrimination task (S+ vs. S‐; e.g., blue vs. yellow) and then probed for stimulus control with two types of probe trials, S+ versus a new stimulus (Select–control probes) and S‐ versus a new stimulus (Reject–control probes). For Group Different, a new‐stimulus color (e.g., white) was used in one type of probe and another color (e.g., black) was used in the other type. For Group Same, a single new‐stimulus color was used in both types of probes. On Select probes, the bees always preferred S+ to the new stimulus. On Reject probes, results were mixed. Depending on the colors used in training and probing, bees responded to both stimuli, and even preferred the S‐. The data suggest no control by the negative function of the S‐ and support the select‐stimulus control hypothesis of responding.
Higher human T‐cell leukaemia virus type 1 (HTLV‐1) proviral load is associated with end‐stage kidney disease in Indigenous Australians: Results of a case‐control study in central Australia
Authors: Talukder Mohammad Radwanur R. , Walley Rebecca , Pham Hai , Schinke Shane , Woodman Richard , Wilson Kim , Sajiv Cherian , Einsiedel Lloyd
Published: June 2019

Case series suggest that human T‐cell leukaemia virus type 1 (HTLV‐1) is associated with kidney disease; however, little is known about the impact of proviral load (PVL). The present study was commenced to determine whether higher HTLV‐1 PVL is associated with end stage kidney disease (ESKD) in Indigenous Australians. A case‐control study was conducted in Alice Springs Hospital (ASH), 1 July 2007 to 30 November 2015. Cases included all 80 Indigenous adults (>17 years) with HTLV‐1c and ESKD, matched 1:1 by sex to controls with HTLV‐1 who had no renal disease or other recognised disease associations of HTLV‐1, and were recruited during the same period. The association between PVL and ESKD was assessed using logistic regression. Median (IQR) HTLV‐1c PVL for subjects with ESKD (6.86, IQR (3.35, 8.23) log copies per 105 peripheral blood leukocytes (PBL) (ie, 0.95; IQR, 0.03; 3.70% PBL) was significantly higher than that of the asymptomatic group (3.47; IQR (−0.04, 6.61) log copies per 10
5 PBL (ie, 0.01; IQR, 0.00; 0.52% PBL) (asymptomatic vs ESKD, P (ranksum) < .001). Major factors associated with ESKD were diabetes (adjusted odds ratio [aOR], 21.80; 95% CI, 4.84, 98.22; P < .001), hypertension (aOR, 4.16; 1.11, 15.64; P = .03), remote residence (aOR, 5.34; 95% CI, 1.17, 27.29; P = .03) and HTLV‐1c PVL greater than or equal to 100 copies per 10
5 PBL (aOR, 3.67; 95% CI, 1.36, 9.92; P = .01). Higher HTLV‐1c PVL are strongly associated with inflammatory diseases. The high HTLV‐1c PVL reported here may have clinical implications for people with HTLV‐1 who require haemodialysis. Longitudinal studies are required to determine whether this association is causal.
Inflammation‐regulatory microRNAs: Valuable targets for intracranial atherosclerosis
Authors: Li Jia , Li Keshen , Chen Xiangyan
Published: June 2019

Intracranial atherosclerosis (ICAS) is the most common etiology of ischemic stroke with the highest rate of stroke recurrence. Little is currently known of the association of circulating inflammation‐regulatory microRNAs (miRNAs) with ICAS. In this review, we briefly discuss that ICAS is characterized as a dynamic and unstable inflammatory process within intracranial arteries. Then, as a topic of discussion, we mainly concentrate on the following crucial miRNAs (miR‐155, miR‐27a/b, miR‐342‐5p, miR‐21, miR‐124, and miR‐223) by virtue of their multiple roles in regulating the progression of atherosclerosis involved with systemic and local inflammatory activities in cerebral arteries. Clinical perspectives of other miRNAs (miR‐146a, miR‐181b, miR‐126, miR‐143, and let‐7b) in ICAS are also mentioned. In relevance to the inflammatory mechanisms of ICAS, the in‐depth knowledge of miRNAs engaged in the progression of intracranial atherosclerotic plaques may provide an approach to a more precise exploration of diagnostic and therapeutic targets for ICAS.
Twelve‐month outcomes of a bioabsorbable implant for in‐office treatment of dynamic nasal valve collapse
Authors: Sidle Douglas M. , Stolovitzky Pablo , Ow Randall A. , Silvers Stacey , Matheny Keith , Bikhazi Nadim , Wani Manish , Scurry W. Cooper , Most Sam P.
Published: June 2019

Objectives

To examine 12‐month outcomes for in‐office treatment of dynamic nasal valve collapse (NVC) with a bioabsorbable implant.

Study Design

Prospective, multicenter, nonrandomized study.

Methods

One hundred sixty‐six patients with severe‐to‐extreme class of Nasal Obstruction Symptom Evaluation (NOSE) scores were enrolled at 16 U.S. clinics (November 2016–July 2017). Patients were treated with a bioabsorbable implant (Latera, Spirox Inc., Redwood City, CA) to support the lateral wall, with or without concurrent inferior turbinate reduction (ITR), in an office setting. NOSE scores and Visual Analog Scale (VAS) were measured at baseline and 1, 3, 6, and 12 months postoperatively. The Lateral Wall Insufficiency (LWI) score was determined by independent physicians observing the lateral wall motion video.

Results

One hundred five patients were treated with implant alone, whereas 61 had implant + ITR. Thirty‐one patients reported 41 adverse events, all of which resolved with no clinical sequelae. Patients showed significant reduction in NOSE scores throughout 12 months postoperatively (77.4 ± 13.4 baseline vs. 36.2 ± 22.7 at 1 month postoperatively, 33.0 ± 23.4 at 3 months, 32.1 ± 24.6 at 6 months, and 30.3 ± 24.3 at 12 months; P < 0.001). They also showed significant reduction in VAS scores postoperatively (69.7 ± 18.1 baseline vs. 31.3 ± 27.1 at 12 months postoperatively, P < 0.001). These results were similar in patients treated with implant alone and those treated with the implant + ITR. Consistent with patient‐reported outcomes, postoperative LWI scores were demonstrably lower (1.42 ± 0.09 and 0.93 ± 0.08 pre‐ and postoperatively, P < 0.001).

Conclusion

In‐office treatment of dynamic NVC with a bioabsorbable implant improves clinical evidence of LWI at 6 months and improves nasal obstructive symptoms in a majority of patients up to 12 months.

Level of Evidence

2b

Laryngoscope, 130:1132–1137, 2020
Fibroblast growth factor receptor promotes progression of cutaneous squamous cell carcinoma
Authors: Khandelwal Alok R. , Kent Burton , Hillary Savage , Alam Md Maksudul , Ma Xiaohua , Gu Xin , DiGiovanni John , Nathan Cherie‐Ann O.
Published: June 2019

Cutaneous squamous cell carcinoma (cSCC) is a keratinocyte‐derived invasive and metastatic tumor of the skin. It is the second‐most commonly diagnosed form of skin cancer striking 200 000 Americans annually. Further, in organ transplant patients, there is a 65‐ to 100‐fold increased incidence of cSCC compared to the general population. Excision of cSCC of the head and neck results in significant facial disfigurement. Therefore, increased understanding of the mechanisms involved in the pathogeneses of cSCC could identify means to prevent, inhibit, and reverse this process. In our previous studies, inhibition of fibroblast growth factor receptor (FGFR) significantly decreased ultraviolet B‐induced epidermal hyperplasia and hyperproliferation in SKH‐1 mice, suggesting an important role for FGFR signaling in skin cancer development. However, the role of FGFR signaling in the progression of cSCC is not yet elucidated. Analysis of the expression of FGFR in cSCC cells and normal epidermal keratinocytes revealed protein overexpression and increased FGFR2 activation in cSCC cells compared to normal keratinocytes. Further, tumor cell‐specific overexpression of FGFR2 was detected in human cSCCs, whereas the expression of FGFR2 was low in premalignant lesions and normal skin. Pretreatment with the pan‐FGFR inhibitor; AZD4547 significantly decreased cSCC cell‐cycle traverse, proliferation, migration, and motility. Interestingly, AZD4547 also significantly downregulated mammalian target of rapamycin complex 1 and AKT activation in cSCC cells, suggesting an important role of these signaling pathways in FGFR‐mediated effects. To further bolster the in vitro studies, NOD.Cg‐Prkdcscid Il2rgtm1Wjl/SzJ mice with SCC12A tumor xenografts treated with AZD4547 (15 mg/kg/bw, twice weekly oral gavage) exhibited significantly decreased tumor volume compared to the vehicle‐only treatment group. The current studies provide mechanistic evidence for the role of FGFR and selectively FGFR2 in the early progression of cSCC and identifies FGFR as a putative therapeutic target in the treatment of skin cancer.
Postural Abnormalities in Parkinson's Disease: An Epidemiological and Clinical Multicenter Study
Authors: Tinazzi Michele , Gandolfi Marialuisa , Ceravolo Roberto , Capecci Marianna , Andrenelli Elisa , Ceravolo Maria Gabriella , Bonanni Laura , Onofrj Marco , Vitale Michela , Catalan Mauro , Polverino Paola , Bertolotti Claudio , Mazzucchi Sonia , Giannoni Sara , Smania Nicola , Tamburin Stefano , Vacca Laura , Stocchi Fabrizio , Radicati Fabiana G. , Artusi Carlo Alberto , Zibetti Maurizio , Lopiano Leonardo , Fasano Alfonso , Geroin Christian
Published: June 2019

Introduction

The overall frequency of postural abnormalities (PA) in Parkinson's disease (PD) is unknown. We evaluated the overall prevalence of PA and assessed the association with demographic and clinical variables.

Methods

For this multicenter, cross‐sectional study, consecutive PD outpatients attending 7 tertiary Italian centers were enrolled. Patients were evaluated and compared for the presence of isolated PA such as camptocormia, Pisa syndrome, and anterocollis and for combined forms (ie, camptocormia + Pisa syndrome) together with demographic and clinical variables.

Results

Of the total 811 PD patients enrolled, 174 (21.5%; 95% confidence interval [CI], 18.6%–24.3%) presented PA, 144 of which had isolated PA and 30 had combined PA. The prevalence of camptocormia was 11.2% (95% CI, 9%–13.3%), Pisa syndrome 8% (95% CI, 6.2%–9.9%), and anterocollis 6.5% (95% CI, 4.9%–8.3%). Patients with PA were more often male and older with longer disease duration, more advanced disease stage, more severe PD symptoms, a bradykinetic/rigid phenotype, and poorer quality of life. They were initially treated with levodopa, and more likely to be treated with a combination of levodopa and dopamine agonist, took a higher daily levodopa equivalent daily dose, and had more comorbidities. Falls and back pain were more frequent in PD patients with PA than in those without PA. Multiple logistic regression models confirmed an association between PA and male gender, older age, Hoehn and Yahr stage, and total Unified Parkinson's Disease Rating Scale score.

Conclusions

PA are frequent and disabling complications in PD, especially in the advanced disease stages.
An overview of new antitubercular drugs, drug candidates, and their targets
Authors: Bahuguna Aparna , Rawat Diwan S.
Published: June 2019

The causative agent of tuberculosis (TB), Mycobacterium tuberculosis and more recently totally drug‐resistant strains of M. tuberculosis, display unique mechanisms to survive in the host. A four‐drug treatment regimen was introduced 40 years ago but the emergence of multidrug‐resistance and more recently TDR necessitates the identification of new targets and drugs for the cure of M. tuberculosis infection. The current efforts in the drug development process are insufficient to completely eradicate the TB epidemic. For almost five decades the TB drug development process remained stagnant. The last 10 years have made sudden progress giving some new and highly promising drugs including bedaquiline, delamanid, and pretomanid. Many of the candidates are repurposed compounds, which were developed to treat other infections but later, exhibited anti‐TB properties also. Each class of drug has a specific target and a definite mode of action. These targets are either involved in cell wall biosynthesis, protein synthesis, DNA/RNA synthesis, or metabolism. This review discusses recent progress in the discovery of newly developed and Food and Drug Administration approved drugs as well as repurposed drugs, their targets, mode of action, drug‐target interactions, and their structure‐activity relationship.
Wilkinson filtering power divider using coupled lines and T‐shaped stub
Authors: Xu Kai‐Da , Xu Jiashuai , Li Daotong
Published: June 2019

A new Wilkinson filtering power divider (PD) with high performance has been presented. By employing four pairs of parallel‐coupled lines and a T‐shaped stub to construct the filtering PD, sharp roll‐off skirts and high stopband rejections can be achieved with three transmission poles and six transmission zeros. Theoretical deduction is presented to verify the proposed structure. For demonstration, a filtering PD example with center frequency of 2 GHz and 3‐dB fractional bandwidth of 48% is fabricated and measured. It is shown that the measured minimum insertion loss within the passband is less than 0.4 dB. The lower stopband rejection of over 17 dB and upper stopband rejection of more than 23 dB from 2.7 to 4.9 GHz can be achieved. The measured isolations between two output ports are greater than 20 dB within the passband.
Analysis of electromagnetic behaviors induced by contact failure in electrical connectors
Authors: Li Qingya , Gao Jinchun , Flowers George T.
Published: June 2019

Electrical connectors are widely used in electrical devices as an interconnect element and their reliability is a critical factor in device performance. However, there are multiple factors that may lead to poor reliability. These include contact failure induced by temperature and humidity, vibration, and atmospheric contamination, which may induce deterioration of the transmitted signal and leakage of electromagnetic energy. In the current work, the contact failure characteristics of a specific connector are investigated through measurement and analysis of high frequency parameters and spectrums. Based on transmission line theory and electrical contact theory, an equivalent model was developed to explore the effect of contact failure on high frequency parameters. Experiments were conducted using a network analyzer, signal generator, signal analyzer, and H‐field probe. The high frequency parameters were measured and compared with the calculated values, with consistent results. The leakage spectrums were measured with an H‐field probe for a variety of input signal amplitudes and frequencies and loose contact conditions. The results indicate that leakage increases with higher frequency and greater input signal amplitude.
The discrete duality finite volume method for a class of quasi‐Newtonian Stokes flows
Authors: He Zhengkang , Li Rui , Chen Jie , Chen Zhangxin
Published: June 2019

In this paper, we propose a discrete duality finite volume (DDFV) scheme for the incompressible quasi‐Newtonian Stokes equation. The DDFV method is based on the use of discrete differential operators which satisfy some duality properties analogous to their continuous counterparts in a discrete sense. The DDFV method has a great ability to handle general geometries and meshes. In addition, every component of the velocity gradient can be reconstructed directly, which makes it suitable to deal with the nonlinear terms in the quasi‐Newtonian Stokes equation. We prove that the proposed DDFV scheme is uniquely solvable and of first‐order convergence in the discrete L2‐norms for the velocity, the strain rate tensor, and the pressure, respectively. Ample numerical tests are provided to highlight the performance of the proposed DDFV scheme and to validate the theoretical error analysis, in particular on locally refined nonconforming and polygonal meshes.
Risk of congenital heart diseases associated with NAT2 genetic polymorphisms and maternal polycyclic aromatic hydrocarbons exposure
Authors: Tao Jing , Li Nana , Liu Zhen , Qiu JinPing , Deng Ying , Li Xiaohong , Chen Ming , Yu Jing , Zhu Jun , Yu Ping , Wang Yanping
Published: June 2019

Objective

N‐Acetyltransferase 2 (NAT2) is a phase II xenobiotic‐metabolizing enzyme participating in the detoxification of toxic arylamines and aromatic amines. The present study was designed to investigate whether maternal NAT2 genetic polymorphisms are associated with fetal susceptibility to congenital heart diseases (CHDs) and to assess whether the risk is modified by polycyclic aromatic hydrocarbons (PAHs) exposure.

Methods

We conducted a hospital‐based case‐control study to investigate the association of NAT2 gene polymorphisms (rs1799930 G/A, rs1208 A/G, and rs1799931 G/A) and the combinations of PAHs exposure and genetic variants with the risk of CHDs. Three hundred fifty‐seven mothers of CHDs fetuses and 270 control mothers were recruited. Logistic regression models for the risk of CHDs were applied to determine the effect of NAT2 polymorphisms, as well as gene‐exposure interactions.

Results

Our study did not demonstrate an association of maternal NAT2 genetic polymorphisms alone with CHDs occurrence. However, we found that certain genetic polymorphisms of NAT2 in the present of high PAHs exposure have a higher risk of CHDs.

Conclusion

Our study suggests that the risk of CHDs associated with maternal NAT2 gene polymorphisms is potentiated by PAHs exposure.
Preparation of fast‐degrading poly(lactic acid)/soy protein concentrate biocomposite foams via supercritical CO2 foaming
Authors: Liu Tong , Peng Xiang‐Fang , Mi Hao‐Yang , Li Heng , Turng Lih‐Sheng , Xu Bai‐Ping
Published: June 2019

To increase the degradation rate of poly(lactic acid) (PLA), soy protein concentrate (SPC) was introduced via melt compounding using a self‐developed, co‐rotating, non‐twin‐screw extruder. Poly(2‐ethyl‐2‐oxazoline) (PEOX) and diphenyl methane diisocyanate (MDI) were added to plasticize the melt and improve the compatibility between PLA and SPC. The PLA/SPC blends were subsequently foamed using supercritical carbon dioxide (CO2) as a blowing agent to produce porous composites. The involvement of SPC promoted cold crystallization of PLA but reduced the thermal stability of the blends. PLA showed a strong interfacial bonding with modified SPC, and the SPC formed continuous three‐dimensional networks when its proportion reached 30 wt%. In the foaming process, SPC domains acted as heterogeneous nucleation sites, which resulted in enhanced cell densities and reduced cell diameters. The PLA/SPC (70:30) sample showed the finest cell structure due to the presence of the SPC network. For the same blends, increasing the foaming pressure from 16 to 20 MPa enhanced the cell density by about 5 times. The water absorption rate and the biodegradation rate of the PLA/SPC foams were much higher than that of neat PLA due to the hydrophilicity of SPC and the porous structure of the foams. POLYM. ENG. SCI., 59:1753–1762, 2019. © 2019 Society of Plastics Engineers
Classroom goal structures: Observations from urban and rural high school classes in China
Authors: Wang Jing , Rao Nirmala
Published: June 2019

This study reports on the goal structures of one rural and one urban Grade 11 class in China, based on classroom observations and teacher and student interviews. Classroom observations, conducted over a 6‐month period, focused on physical settings and classroom activities. In each class, seven students and the homeroom teacher were interviewed to discern their views about classroom goal structures. Results indicated that although high scores and rankings on tests were admired, students were also encouraged to master knowledge, exert effort, develop good habits, and learn from their errors, reflecting the coexistence of both mastery and performance goals. Comparisons revealed that the rural class had a predominantly examination‐oriented focus whereas the urban class did not place as great importance on examination outcomes. Implications of the findings for research and practices are discussed.
In vitro drug delivery performance of five valved holding chambers with and without facemasks
Authors: Csonka Péter , Lehtimäki Lauri
Published: June 2019

Background

Valved holding chambers (VHCs) are essential for efficient pulmonary delivery of inhaled medication in preschool children. The numerous devices in the market vary in material, aerodynamic characteristics, volume, valve properties, and mask design. Drug delivery is affected by the VHC characteristics as well as by the age and breathing pattern of the child.

Methods

We measured the drug delivery efficacy of five VHCs widely available in the market, evaluated the effect of facemasks and tested the differences between manufacturing lots. A breathing simulator was used to mimic normal (respiratory rate [RR] 25/minute and tidal volume (VT) 200 mL) and obstructive (RR 50/minute and VT 50 mL) breathing of infants and toddlers.

Results

Salbutamol output was significantly higher with a normal breathing pattern compared to the obstructive breathing pattern in most VHCs. Without masks, the differences in the median in vitro filter doses of salbutamol were mainly from 2 to 10‐fold among different types of VHCs. With masks, there was a greater than 20‐fold difference in drug delivery capacity between the most and least effective devices. Most VHCs had a notable variation of performance between individual devices from different lots within the same brand.

Conclusions

There was an extreme variation in the salbutamol delivery performance among different types of VHCs for both normal and obstructive pediatric breathing patterns with and without masks. This magnitude of performance variability can have significant and unpredictable clinical implications.
Unsaturation in binuclear iron carbonyl complexes of the split (3 + 2) five‐electron donor hydrocarbon ligand bicyclo[3.2.1]octa‐2,6‐dien‐4‐yl: Role of agostic hydrogen atoms
Authors: Wan Di , Li Huidong , Shi Liming , Wu Xueke , Fan Qunchao , Feng Hao , King Robert Bruce , Schaefer Henry F.
Published: June 2019

The experimentally known split (3 + 2) five‐electron donor bicyclo[3.2.1]octa‐2,6‐dien‐4‐yl (bcod) ligand provides a flexible alternative to the rigid planar cyclopentadienyl (Cp) ligand. In this connection, the structures and energetics of the binuclear iron carbonyl complexes (bcod)2Fe2(CO)n (n = 4, 3, 2, 1) have been investigated by density functional theory for comparison with the corresponding Cp2Fe2(CO)n derivatives. The cis and trans doubly CO‐bridged (bcod)2Fe2(μ‐CO)2(CO)2 structures are the lowest energy tetracarbonyl structures, similar to the Cp2Fe2(CO)4 system. However, an unbridged (bcod)2Fe2(CO)4 isomer lies only ~1 kcal/mol in energy above the doubly bridged isomers. The flexibility of the bcod ligand leads to low‐energy singlet and triplet spin state structures with agostic hydrogen atoms for the unsaturated (bcod)2Fe2(CO)n (n = 3, 2, 1) systems. Analogous structures are not found in the corresponding Cp2Fe2(CO)n systems with the rigid Cp ligand. Such structures, effectively involving donation of an electron pair from an olefinic C‐H bond to an iron atom through three‐center two‐electron C‐H‐Fe bonding, are energetically competitive with isomeric structures with metal‐metal multiple bonds.
Fabrication of Fly Ash‐Based Mesoporous Aluminosilicate Oxides Loaded with Zinc and its Synergistic Fire Resistancy in Polypropylene
Authors: Zhang Sheng , Tang Wufei , Li Limin , Li Hongfei , Sun Jun , Gu Xiaoyu , Chen Shou , Peng Xiaohua , Bourbigot Serge
Published: June 2019

A kind of mesoporous aluminosilicate oxides (MAOs) were fabricated from industrial waste, coal fly ash. After loaded with zinc on MAO, the product MAO‐Zn was characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy (SEM). MAO‐Zn was incorporated with intumescent flame retardant (IFR) together and used in polypropylene (PP). Basic characterization including limiting oxygen index (LOI), vertical burning test (UL‐94), and cone calorimeter test (CCT) were finished. The result showed the LOI value of PP was only 17.7 and cannot pass UL‐94 grade; however, 25 wt% IFR in PP help the composite obtained LOI value of 27.6 and passed UL‐94V‐1 grade. Surprisingly, with only 2 wt% MAO‐Zn substitution of IFR, the LOI of PP/IFR composite sharply went up to 37.2 and passed V‐0 grade. CCT results documented that heat, smoke, and fatal gas release were obviously suppressed by IFR/MAO‐Zn combination. By SEM observation and quantitative analysis of TGA results, the contribution of MAO‐Zn was summarized as adsorption of heat/smoke and promotion on charring. It was worth mentioning that the low dose of MAO‐Zn (≤ 3 wt%) did not bring further deterioration on mechanical properties. J. VINYL ADDIT. TECHNOL., 26:135–143, 2020. © 2019 Society of Plastics Engineers
Surface functionalization of carbon nanotubes by biological adhesive polymers carbopol for developing high‐permittivity polymer composites
Authors: Liu Hongfu , Tang Yaokai , Jin Zhao , Song Shichuan , Zhang Pingping , Zhao Shugao , Guan Shanshan , Guan Wenna
Published: June 2019

Surface functionalization of carbon nanotubes (CNTs) by biological adhesive polymers carbopol (CP) was developed by simply mixing CNT suspension and an aqueous solution of CP without any toxic solvents. CP can be easily coated onto CNTs through hydrogen bonds OCOH⋯NH2CO and electrostatic interaction between COO on CP and NH3+ on CNTs. After modification, the surface of the CNT is endowed with a large number of carboxyl groups, which can effectively prevent the reaggregation of CNT by electrostatic repulsion between the ionized carboxyl groups. Hence, highly dispersed functionally modifying CNT by CP (CP‐CNT) filler in polydimethylsiloxane (PDMS) matrix can be obtained. More important, with the help of adhesive properties of CP, the interfacial compatibility between fillers and matrix can also be improved. Thus, the CP‐CNT/PDMS composites exhibited higher dielectric permittivity comparing with CNT/PDMS composites at the same filler content. We present a potential and green approach of surface functionalization of CNT for preparing high‐permittivity polymer composites. J. VINYL ADDIT. TECHNOL., 26:165–172, 2020. © 2019 Society of Plastics Engineers
Evaluation of a naturally derived tannin extracts biopolymer additive in drilling muds for high-temperature well applications
Authors: Ismail Abdul R. , Mohd Norddin M. N. A. , Latefi Nur A. S. , Oseh Jeffrey O. , Ismail Issham , Gbadamosi Afeez O. , Agi Augustine J.
Published: June 2019

The formulations of drilling fluids using conventional clays are often faced with difficulties in the control of rheology, filtration and gelation, owing to the flocculation of the clay at the temperature above 250 °F. In this study, tannins were extracted from the bark wastes of Rhizophora Mucronata spp. (RMTE) and used as a deflocculant to formulate water-based muds (WBMs). The efficacy of reducing the gelation and viscosity of WBMs with the extracted RMTE was compared with commercial Modified Desco Tannin (MDT). The RMTE was characterized using Fourier-transform infrared spectroscopy (FTIR). Rheological and filtration control properties tests were conducted on the RMTE and MDT mud samples before and after hot rolling tests at different temperatures of 225 °F, 250 °F, 275 °F and 300 °F. FTIR test data indicate the presence of different active functional groups in the RMTE structure, especially the hydroxyl (–OH) groups, which are responsible for the good thinning ability of the RMTE. Experimental data of the WBM after hot rolling tests with 8 g concentration at 300 °F show a 43.5% reduction of plastic viscosity with MDT and 50% reduction with RMTE. With a concentration of 2 g, the yield point of the WBM with commercial MDT and locally derived RMTE at 225 °F before hot rolling tests reduced by 50% and 57.1%, respectively. Furthermore, the addition of RMTE and MDT to the WBM reduced the filtrate volume and the gel strength. The experimental data indicate that the RMTE shows better deflocculating performance compared to that of the MDT, illustrating the need for its application in WBMs for high-temperature wells.
A High Wave Speed Basal Sedimentary Layer Identified From Seismic Imaging of the Plate Boundary in Central Cascadia
Authors: Peterson D. E. , Keranen K. M.
Published: June 2019

The Cascadia subduction zone is known to produce large tsunamigenic ruptures but has enigmatically little microseismicity in historic times. With the paucity of microseismicity and recent long‐offset multichannel seismic imaging in the past 20 years, poor constraints are available for Cascadia on plate boundary structure, fluid pressure, and mechanical properties, the combination of which control seismogenic behavior. Here we present prestack time‐migrated seismic images from two profiles across the central Cascadia megathrust offshore southern Washington, focused on the plate boundary. Our results indicate that (1) a ~1 km‐thick sedimentary unit with high seismic wave speed (over 4.5 km/s) directly overlies oceanic crust and (2) the décollement is at the interface between oceanic crust and the high wave speed unit. The high wave speed begins seaward of the deformation front and is consistent with porosity near or below 5%, interpreted to result from a combination of depth compaction and diagenesis over young, hot oceanic crust. The location of the décollement is identified by the participation of the entire sedimentary package in upper‐plate compressional deformation. We suggest that the low‐porosity basal unit may focus fluid escape from oceanic crust along faults and may be mechanically strong similar to Sumatra, where a high‐wave speed, diagenetically altered basal unit facilitated megathrust rupture to the trench. A uniformly strong basal unit above the plate interface at Cascadia may inhibit microseismicity while building stress released in great earthquakes.
A Circular Polarization Reconfigurable Antenna Based on Off‐Center‐Driven Dipoles
Authors: Zhang P.P. , Lin G.Y. , Xiao M.Z. , Cui Y.H.
Published: June 2019

A novel circular polarization (CP) reconfigurable antenna is proposed. The CP antenna consists of two folded off‐center‐driven dipoles. By switching four PIN diodes in the off‐center‐driven dipoles, the senses of CP can be changed between the left‐handed CP and the right‐handed CP. Two parasitic rectangular loops are added to the folded off‐center‐driven dipoles to improve the bandwidth. A T‐shaped microstrip probe line is used to feed the antenna. Experimental results show that the CP reconfigurable antenna achieves an impedance bandwidth of 31% (2.05–2.8 GHz) for return los >10 dB and a CP bandwidth of 16% (2.3–2.7 GHz) for axial ratio <3 dB. The measured gain of the CP reconfigurable antenna is about 7 dBi.
Variation of Digisonde‐Derived Scale Height During Quiet and Disturbed Geomagnetic Conditions Over an African Equatorial Station
Authors: Adebiyi S. J. , Adeniyi J. O. , Reinisch B. W. , Adebesin B. O. , Ikubanni S. O. , Adimula I. A. , Oladipo O. A. , Olawepo A. O. , Joshua B. W. , Adekoya B. J.
Published: June 2019

One inherent parameter in the extrapolation of ionospheric topside profile is the scale height, which can be derived from an ionogram. For the first time in the African equatorial region, the variation of digisonde‐derived scale height (Hm) is investigated at Ilorin (Geog. 8.50°N; 4.50°E; dip. –7.9°) during quiet and disturbed conditions. Diurnal pattern of Hm revealed a consistent but insignificant hump before sunrise, followed by a marked increase, maximizing around local noon, and a decrease thereafter till nighttime. The daytime values, however, shows significant seasonal differences. A striking observation is the highest value in December solstice and lowest during June solstice. This is attributed to the influence of ion‐neutral drag and topside thermal structure on the shape of the topside ionosphere. Hm also exhibits high correlation with the bottomside thickness parameter (B0) and the total electron content; however, it is generally moderate with F2 layer critical frequency (foF2) and peak height (hmF2). These correlations do not show significant seasonal dependence. The large network of Global Positioning System (receivers may serve as a good data source for the reconstruction of the topside profile owing to the excellent relationship between Hm and total electron content. The linear model developed to describe the dependence of Hm on B0 generally gives a good representation of Hm with digisonde‐B0 as input. Large discrepancies were observed with the three options of the IRI 2016‐B0 used as input. The B0 models, if well established at the station, could be an alternative source to estimate Hm.
Framework for High‐End Estimates of Sea Level Rise for Stakeholder Applications
Authors: Stammer D. , van de Wal R. S. W. , Nicholls R. J. , Church J. A. , Le Cozannet G. , Lowe J. A. , Horton B. P. , White K. , Behar D. , Hinkel J.
Published: June 2019

An approach to analyze high‐end sea level rise is presented to provide a conceptual framework for high‐end estimates as a function of time scale, thereby linking robust sea level science with stakeholder needs. Instead of developing and agreeing on a set of high‐end sea level rise numbers or using an expert consultation, our effort is focused on the essential task of providing a generic conceptual framework for such discussions and demonstrating its feasibility to address this problem. In contrast, information about high‐end sea level rise projections was derived previously either from a likely range emerging from the highest view of emissions in the Intergovernmental Panel on Climate Change assessment (currently the Representative Concentration Pathway 8.5 scenario) or from independent ad hoc studies and expert solicitations. Ideally, users need high‐end sea level information representing the upper tail of a single joint sea level frequency distribution, which considers all plausible yet unknown emission scenarios as well as involved physical mechanisms and natural variability of sea level, but this is not possible. In the absence of such information we propose a framework that would infer the required information from explicit conditional statements (lines of evidence) in combination with upper (plausible) physical bounds. This approach acknowledges the growing uncertainty in respective estimates with increasing time scale. It also allows consideration of the various levels of risk aversion of the diverse stakeholders who make coastal policy and adaptation decisions, while maintaining scientific rigor.
Rock On with a Group That Makes Music from Geophysical Data
Authors: Duncombe Jenessa
Published: June 2019

Musical numbers include an Italian fault and a tour of an African greenstone belt.
Latest Climate Model Points to Hotter Earth
Authors: Joel Lucas
Published: June 2019

The model’s dire forecast matches those of other leading models.
Detection of Ocean Internal Tide Source Oscillations on the Slope of Aogashima Island, Japan
Authors: Fukao Y. , Miyama T. , Tono Y. , Sugioka H. , Ito A. , Shiobara H. , Yamashita M. , Varlamov S. , Furue R. , Miyazawa Y.
Published: June 2019

Barotropic tidal currents over bottom topography force density surfaces to oscillate vertically and thereby to act as quasi‐stationary internal tide sources. Deploying a seafloor pressure gauge array with an aperture of 30 km for a year (2014–2015), we detected the low‐mode semidiurnal internal tidal waves propagating with a horizontal phase speed of ~1 m/s in the onshore and offshore directions over the array along the eastern slope of Aogashima Island, south of Japan. The amplitudes of the offshore propagating waves were greater than those of the onshore propagating waves, and both were positively correlated with the amplitudes of the local semidiurnal tide, which peaked in September and March. A tide‐resolving ocean circulation model (JCOPE‐T) well reproduced the observed onshore and offshore internal tidal wave propagation. The model indicated a standing wave region on the slope, where offshore propagating waves interact with standing waves locally pinned to the slope. Along the same profile over a distance of 100 km, we conducted seismic‐oceanographic analysis of the legacy multichannel seismic reflection data to retrieve vertical cross sections of the reflecting layers, which indicated sharp temperature changes in the ocean. Many of the slant reflecting layers were subparallel to the contour lines of the semidiurnal internal‐tide‐associated temperature anomalies in the JCOPE‐T model, suggesting a causal link between the fine reflection layering structure and the semidiurnal low‐mode internal tidal field.
Climate‐Sensitive Controls on Large Spring Emissions of CH4 and CO2 From Northern Lakes
Authors: Jansen J. , Thornton B. F. , Jammet M. M. , Wik M. , Cortés A. , Friborg T. , MacIntyre S. , Crill P. M.
Published: June 2019

Northern lakes are important sources of the climate forcing trace gases methane (CH4) and carbon dioxide (CO2). A substantial portion of lakes' annual emissions can take place immediately after ice melt in spring. The drivers of these fluxes are neither well constrained nor fully understood. We present a detailed carbon gas budget for three subarctic lakes, using 6 years of eddy covariance and 9 years of manual flux measurements. We combine measurements of temperature, dissolved oxygen, and CH4 stable isotopologues to quantify functional relationships between carbon gas production and conversion, energy inputs, and the redox regime. Spring emissions were regulated by the availability of oxygen in winter, rather than temperature as during ice‐free conditions. Under‐ice storage increased predictably with ice‐cover duration, and CH4 accumulation rates (25 ± 2 mg CH4‐C·m−2·day−1) exceeded summer emissions (19 ± 1 mg CH4‐C·m−2·day−1). The seasonally ice‐covered lakes emitted 26–59% of the annual CH4 flux and 15–30% of the annual CO2 flux at ice‐off. Reduced spring emissions were associated with winter snowmelt events, which can transport water downstream and oxygenate the water column. Stable isotopes indicate that 64–96% of accumulated CH4 escaped oxidation, implying that a considerable portion of the dissolved gases produced over winter may evade to the atmosphere.
Modeling of the Ionospheric Critical Frequency of the F2 layer over Asia based on Modified Temporal‐Spatial Reconstruction
Authors: Wang Jian , Ma Jian‐guo , Huang Xiang‐dong , Bai Hong‐mei , Chen Qiang , Cheng Hua‐ye
Published: June 2019

A model based on modified temporal‐spatial reconstruction is proposed to improve the accuracy of predicting the monthly median ionospheric critical frequency of the F2 layer. This model has three new characteristics. (1) The solar activity parameters of the 10.7‐cm solar radio flux and sunspot number are together introduced into temporal reconstruction. (2) Both the geomagnetic dip and its modified value are chosen as features of the geographical spatial variation for spatial reconstruction. (3) Harmonic functions are used to represent the ionospheric critical frequency of the F2 layer, which reflects seasonal and solar cycle variations. Furthermore, combining the least squares fitting regression for these characteristics with harmonic analysis, a valid model can be established from vertical sounding data spread across three ionospheric regions (high, middle, and low latitudes in Asia). Statistical results reveal that the ionospheric critical frequency of the F2 layer calculated by the proposed model is consistent with the trend of the monthly median observations. The average root‐mean‐square error is only 0.70 MHz (corresponding to relative error 11.30%), reflecting that our model outperforms the International Reference Ionosphere model with International Union of Radio Science and Consultative Committee on International Radio (CCIR) coefficients. Moreover, the proposed method has great potential in terms of providing higher prediction accuracy for ionospheric parameters on the global scale.
Synthesis, structure and magnetic properties of copper(ii) azide
Authors: Shi Taqing , Xu Ye , Zou Ya-Jing , Wang Zhao-Xi
Published: June 2019

A novel 3D copper(ii) azide built from 1D double chains with EE azide bridges has been synthesized by hydrothermal reaction. The magnetic analyses reveal that antiferromagnetic interactions are dominant with concomitant spin-canted antiferromagnetism.
Efficient luminescent properties and cation recognition ability of heavy group 13 element complexes of N2O2- and N2O4-type dipyrrins
Authors: Sumiyoshi Akinobu , Chiba Yusuke , Matsuoka Ryota , Noda Takumu , Nabeshima Tatsuya
Published: June 2019

Heavy group 13 element complexes of N2O2- and N2O4-type dipyrrins exhibited efficient luminescent properties and cation recognition ability.
Response surface methodology to optimise the heat-assisted aqueous extraction of phenolic compounds from coffee parchment and their comprehensive analysis
Authors: Aguilera Yolanda , Rebollo-Hernanz Miguel , Cañas Silvia , Taladrid Diego , Martín-Cabrejas María A.
Published: June 2019

A sustainable aqueous extraction method was developed using a response surface methodology optimisation for the recovery of coffee parchment phenolics.
Carboxymethylpachymaran entrapped plant-based hollow microcapsules for delivery and stabilization of β-galactosidase
Authors: Deng Ziyu , Pei Yaqiong , Wang Shishuai , Zhou Bin , Li Jiwei , Hou Xinyao , Li Jing , Li Bin , Liang Hongshan
Published: June 2019

β-Galactosidase (β-Gal) as a dietary supplement can alleviate symptoms of lactose intolerance.
Controllable synthesis of 3-chloro- and 3,3-dichloro-2-oxindoles via hypervalent iodine-mediated chlorooxidation
Authors: Jiang Xinpeng , Yang Liechao , Yang Wenlong , Zhu Yu , Fang Liyun , Yu Chuanming
Published: June 2019

Controllable synthesis of 3-chloro- and 3,3-dichloro-2-oxindoles via chlorooxidation of indoles has been developed in up to 99% yields.
Three-dimensional, hetero-structured, Cu3P@C nanosheets with excellent cycling stability as Na-ion battery anode material
Authors: Zhu Jinliang , He Qiuchen , Liu Yang , Key Julian , Nie Shuangxi , Wu Mingmei , Shen Pei Kang
Published: June 2019

A novel flower-like superstructure consisting of single-crystalline Cu3P porous nanosheets wrapped by a uniform carbon shell exhibits excellent electrochemical performance for sodium storage.
Enhanced selectivity and activity for electrocatalytic reduction of CO2 to CO on an anodized Zn/carbon/Ag electrode
Authors: Gao Yugang , Li Fengping , Zhou Peng , Wang Zeyan , Zheng Zhaoke , Wang Peng , Liu Yuanyuan , Dai Ying , Whangbo Myung-Hwan , Huang Baibiao
Published: June 2019

The selectivity and activity of the anodized Zn/C/Ag composite electrode containing a tiny amount of Ag (∼0.5 wt%) are enhanced by the synergistic effect of Zn, C and Ag.
Electrochromic triphenylamine-based cobalt(ii) complex nanosheets
Authors: Liu Yurong , Sakamoto Ryota , Ho Cheuk-Lam , Nishihara Hiroshi , Wong Wai-Yeung
Published: June 2019

Structurally tunable, readily-processable and stable triphenylamine-based Co(ii) complex nanosheets can be used as solid-state electrochromic materials.
Analysis of residual CFO impact on downlink massive MISO systems
Authors: Nguyen T.‐H. , Van Eeckhaute M. , Determe J.‐F. , Louveaux J. , De Doncker P. , Horlin F.
Published: June 2019

Massive antenna technologies provide a good power focusing gain for emerging communication systems. They can easily be integrated into an orthogonal frequency‐division multiplexing (OFDM) system. However, OFDM is known to be prone to carrier frequency offset (CFO) due to the loss of the orthogonality among OFDM subcarriers. In this Letter, the authors investigate the impact of residual CFO (RCFO) on the downlink performance of massive multiple‐input single‐output (MISO) OFDM systems using matched‐filter (MF) and maximum‐ratio‐transmission (MRT) precoders. Particularly, the exact mean‐square‐error (MSE) expressions of the equalised received signal of both MF and MRT systems are derived. Numerical simulations with Rayleigh fading channels are carried out to validate the analysis. The results show that the RCFO causes a MSE plateau compared to the ideal case of no CFO.
Multi‐cell MMSE data detection for massive MIMO: new simplified bounds
Authors: Alwakeel Ahmed S. , Mehana Ahmed Hesham
Published: June 2019

In this study, the authors analyse and provide new insights into the problem of multi‐cell minimum mean square error (MMSE) detector in massive multiple‐input multiple‐output (MIMO) systems. Their system combines pilot hopping and pilot reuse strategy in the multi‐cell scenario. They obtain a deterministic expression of rate bounds of the uplink system when MMSE is used for channel estimation and data detection. Their result is different from the existing MMSE bounds in massive MIMO literature in that they obtain an achievable rate that is simply a scaled version of that of the matched filter (MF) detection, i.e. the achievable rate of the MF detection can be scaled with a constant, which is a function of the number of antennas and users as well as the power allocation to directly obtain the achievable rate of the MMSE detection. This new finding saves a significant amount of work needed when analysing MMSE detection in massive MIMO since it reduces the problem to obtaining simpler results (using MF analysis) and then extending the result to the MMSE case in a straightforward manner. Simulation results show how tight the achievable rate bound to the actual one at a large number of BS antennas.
Optimal energy management of compressed air energy storage in day‐ahead and real‐time energy markets
Authors: Nojavan Sayyad , Akbari‐Dibavar Alireza , Zare Kazem
Published: June 2019

A hybrid stochastic‐robust optimisation framework for compressed air energy storage (CAES) independent owners is proposed to provide optimal bids and offers in both day‐ahead (DA) and real‐time (RT) energy arbitrage markets. The RT energy market has an excellent opportunity for energy arbitrage, but there are few works which consider this trading. To deal with uncertain characteristics of market prices in the presented study, for DA market stochastic programming (SP) is proposed; however, for RT stage the uncertainty and volatility of electricity price are managed by robust optimisation approach (ROA), and the CAES owner will be safe against undesired price fluctuations. At first, the optimal scheduling of CAES is investigated in the DA market considering price scenarios. After the DA market realisation, additional bids and offers at RT stage will be determined. The proposed optimisation is modelled mathematically as mixed integer linear programming (MIP) and handled by GAMS optimisation software. Using ROA, participation in the RT market can increase the profit of the CAES units. The gained profit in RT market is directly related to robustness level and is selected by decision maker.