bluuebunny/crossref_metadata_2025 huggingface dataset:
A rare case of refractory pouchitis requiring ileal J-pouch excision after total proctocolectomy for ulcerative colitis
Authors: Nishimuta Masato , Ikeda Takuto , Ichihara Akiko , Wada Takashi , Nanashima Atsushi
Published: February 2020

ABSTRACT

Introduction:

Pouchitis is a late-period complication after ileal pouch-anal (canal) anastomosis in patients with ulcerative colitis (UC). Most pouchitis is controlled with the antimicrobial agents. However, some postoperative pouchitis does not respond to antimicrobial agents, and it is very difficult to treat cases of refractory and severe pouchitis.

Presentation of case:

A 66-year-old man underwent total proctocolectomy with ileal pouch-anal anastomosis 22 years ago. He repeatedly presented pouchitis over the last five years. The administration of antimicrobial agents had not been effective, and he sustainably suffered from stenosis symptoms at the ileal pouch-anal anastomosis site. Therefore, we decided to excise the diseased ileal pouch by permanent ileostomy according to technique of abdominoperineal resection. The postoperative course was uneventful, and at 6 months after resection, there was no relapse of abdominal symptoms and he reported a better quality of life.

Discussion:

The cause of pouchitis is still unknown. Oral administration of antimicrobial agents, such as metronidazole and ciprofloxacin are effective for almost pouchitis, but there are some patients of refractory pouchitis. In the cases of refractory pouchitis, the 5-ASA formulation, a steroid enema, immunomodulators, biologics, and plasma pheresis are used. But, despite attempts with these various treatments, there are rare cases that require surgical intervention to excise the diseased ileal pouch.

Conclusions:

We should consider surgical intervention for severe refractory pouchitis after ileal pouch-anal (canal) anastomosis for UC.

Highlights:
Preferences in stapes surgery among American otological society otologists
Authors: Liu Yuan F. , Gupta Avigeet , Nguyen Shaun A. , Lambert Paul R. , Jung Timothy T.
Published: February 2020

Objective

Stapes surgery is technically challenging, yet its methodology is not standardized. We aim to elucidate preferences in stapes surgery among American Otological Society (AOS) otologists and determine if any common practice patterns exist.

Study design

Cross‐sectional study via emailed questionnaire.

Setting

Surgery centers.

Subjects and methods

Members of the AOS were an emailed a survey to quantify variables including surgical volume, anesthetic preference, laser use, type of procedure, footplate sealing technique, antibiotic use, and trainee participation.

Results

Most otologists (71%) performed 2 to 5 stapes surgeries per month under general anesthesia (69%) with stapedotomy (71%) as the preferred procedure. Most (56%) used the rosette method of laser stapedotomy with manual pick debris removal for footplate fenestration. Either the handheld potassium titanyl phosphate (KTP) laser (40%) or handheld carbon dioxide (CO2) laser (33%) was used. The heat‐activated memory hook (51%) was the preferred prosthesis. Footplate sealing method was variable, as was antibiotic use among respondents. Trainee participation was limited, as 42% of otologists allowed residents to place the prosthesis, and fewer allowed residents to crimp the prosthesis, and laser or drill the footplate. Surgeons with higher surgical volume (≥ 6 surgeries per month) demonstrated the following statistically significant correlations: footplate fenestration with laser in a rosette pattern and pick for debris removal (rs = −0.365, P = 0.014) and trainee participation with fellows only (rs = 0.341, P = 0.022).

Conclusions

Trends in various surgical decisions showed a lack of consensus in all aspects of stapes surgery.
Arctic River Dissolved and Biogenic Silicon Exports—Current Conditions and Future Changes With Warming
Authors: Carey Joanna C. , Gewirtzman Jonathan , Johnston Sarah Ellen , Kurtz Andrew , Tang Jianwu , Vieillard Amanda M. , Spencer Robert G. M.
Published: February 2020

Silicon (Si) exports from terrestrial to marine systems can dictate phytoplankton species composition in Arctic coastal waters. Diatoms are often the dominant autotroph in Arctic waters, making Si an important control on Arctic marine primary productivity. Yet even as Arctic regions are among the fastest warming on Earth, we lack baseline knowledge on the magnitudes and controls of Arctic river Si exports. To address uncertainties in current and future Si behavior, we used a combination of field data and modeling to quantify daily yields of dissolved Si (DSi) and biogenic Si (BSi) from a 400 km space‐for‐time latitudinal gradient of seven basins across the boreal‐Arctic transition in Alaska (United States) over the course of 2 years (2015–2016). Mean annual DSi concentrations (33–149 μM) and yields (13–49 kmol km−2 year−1) were significantly and positively correlated with mean basin active layer depth, indicating that permafrost thaw will likely increase DSi fluxes to Arctic coastal waters. Conversely, BSi concentrations (7–16 μM) and yields (2.6–4.5 kmol km−2 year−1) were more uniform across the seven basins, indicating that warming may not substantially alter BSi loads to coastal systems in the near future. Our data also indicate that climatic warming will advance the timing of Si delivery to coastal waters in the spring, although the ratios of Si to nitrogen in Arctic river exports will likely remain steady. These results highlight the important role of basin hydrology, largely driven by permafrost extent, as a key driver of Si exchange at the land‐sea interface in the Arctic.
Characterization and Quantification of Gas Hydrates in the California Borderlands
Authors: Kannberg P. K. , Constable S.
Published: February 2020

Electromagnetic methods are directly sensitive to electrically resistive gas hydrates and can be used to characterize and quantify hydrate deposits. Using a 1 km long deep‐towed marine electromagnetic system, six survey lines were acquired coincident with legacy seismic reflection data in the Santa Cruz Basin in the Outer California Borderlands. While the strongest seismic indicators place hydrate in the central basin, resistors inferred to be hydrate are located predominantly on the flanks of the basin, coincident with gas migration pathways such as faults and steeply dipping strata. Two features consistent with the resistivity profile from previously imaged seafloor methane seeps were also found. Resistivity is related to hydrate saturation through Archie's law, and total hydrate volume of the Santa Cruz Basin is estimated to be 980 × 109 m3 of gas in place.
Extended Cave Drip Water Time Series Captures the 2015–2016 El Niño in Northern Borneo
Authors: Ellis Shelby A. , Cobb Kim M. , Moerman Jessica W. , Partin Judson W. , Bennett A. Landry , Malang Jenny , Gerstner Hein , Tuen Andrew A.
Published: February 2020

Time series of cave drip water oxygen isotopes (δ18O) provide site‐specific assessments of the contributions of climate and karst processes to stalagmite δ18O records employed for hydroclimate reconstructions. We present ~12‐year‐long time series of biweekly cave drip water δ18O variations from three sites as well as a daily resolved local rainfall δ18O record from Gunung Mulu National Park in northern Borneo. Drip water δ18O variations closely match rainfall δ18O variations averaged over the preceding 3–18 months. We observe coherent interannual drip water δ18O variability of ~3‰ to 5‰ related to the El Niño–Southern Oscillation (ENSO), with sustained positive rainfall and drip water δ18O anomalies observed during the 2015/2016 El Niño. Evidence of nonlinear behavior at one of three drip water monitoring sites implies a time‐varying contribution from a longer‐term reservoir. Our results suggest that well‐replicated, high‐resolution stalagmite δ18O reconstructions from Mulu could characterize past ENSO‐related variability in regional hydroclimate.
Link Between Autumnal Arctic Sea Ice and Northern Hemisphere Winter Forecast Skill
Authors: Acosta Navarro J. C. , Ortega P. , Batté L. , Smith D. , Bretonnière P. A. , Guemas V. , Massonnet F. , Sicardi V. , Torralba V. , Tourigny E. , Doblas‐Reyes F. J.
Published: February 2020

Dynamical forecast systems have low to moderate skill in continental winter predictions in the extratropics. Here we assess the multimodel predictive skill over Northern Hemisphere high latitudes and midlatitudes using four state‐of‐the‐art forecast systems. Our main goal was to quantify the impact of the Arctic sea ice state during November on the sea level pressure (SLP), surface temperature, and precipitation skill during the following winter. Interannual variability of the November Barents and Kara Sea ice is associated with an important fraction of December to February (DJF) prediction skill in regions of Eurasia. We further show that skill related to sea ice in these regions is accompanied with enhanced skill of DJF SLP in western Russia, established by a sea ice‐atmosphere teleconnection mechanism. The teleconnection is strongest when atmospheric blocking conditions in Scandinavia/western Russia in November reduce a systematic SLP bias that is present in all systems.
Relating CMIP5 Model Biases to Seasonal Forecast Skill in the Tropical Pacific
Authors: Ding Hui , Newman Matthew , Alexander Michael A. , Wittenberg Andrew T.
Published: February 2020

We examine links between tropical Pacific mean state biases and El Niño/Southern Oscillation forecast skill, using model‐analog hindcasts of sea surface temperature (SST; 1961–2015) and precipitation (1979–2015) at leads of 0–12 months, generated by 28 different models from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Model‐analog forecast skill has been demonstrated to match or even exceed traditional assimilation‐initialized forecast skill in a given model. Models with the most realistic mean states and interannual variability for SST, precipitation, and 10‐m zonal winds in the equatorial Pacific also generate the most skillful precipitation forecasts in the central equatorial Pacific and the best SST forecasts at 6‐month or longer leads. These results show direct links between model climatological biases and seasonal forecast errors, demonstrating that model‐analog hindcast skill—that is, how well a model can capture the observed evolution of tropical Pacific anomalies—is an informative El Niño/Southern Oscillation metric for climate simulations.
Modeled IMF By Effects on the Polar Ionosphere and Thermosphere Coupling
Authors: Liu Jing , Burns Alan G. , Wang Wenbin , Zhang Yongliang
Published: February 2020

There is still an inadequate understanding of how the interplanetary magnetic field (IMF) east‐west component (By) affects thermospheric composition, and other ionospheric and thermospheric fields in a systematic way. Utilizing the state‐of‐art first‐principles Coupled Magnetosphere Ionosphere Thermosphere (CMIT) modeling and TIMED/Global Ultraviolet Imager (GUVI)‐observed ΣO/N2 covering an entire solar cycle (year 2002–2016), as well as a neutral parcel trajectory tracing technique, we emphasize that not only the direction of By, but also its strength relative to the IMF north‐south component (Bz) that has important effects on high latitude convection, Joule heating, electron density, neutral winds, and neutral composition patterns in the upper thermosphere. The Northern Hemisphere convection pattern becomes more twisted for positive By cases than negative cases: the dusk cell becomes more rounded compared with the dawn cell. Consequently, equatorward neutral winds are stronger during postmidnight hours in negative By cases than in positive By cases, creating a favorable condition for neutral composition disturbances (characterized by low ΣO/N2) to expand to lower latitudes. This may lead to a more elongated ΣO/N2 depletion area along the morning‐premidnight direction for negative By conditions compared with the positive By conditions. Backward neutral parcel trajectories indicate that a lower ΣO/N2 parcel in negative By cases comes from lower altitudes, as compared with that for positive By cases, leading to larger enhancements of N2 in the former case.
Gassmann Consistency for Different Inclusion‐Based Effective Medium Theories: Implications for Elastic Interactions and Poroelasticity
Authors: Zhao Luanxiao , Cao Chenghao , Yao Qiuliang , Wang Yirong , Li Hui , Yuan Hemin , Geng Jianhua , Han De‐hua
Published: February 2020

By evaluating the consistency of the Gassmann theory with various inclusion‐based effective medium theories, we investigate the impact of elastic interactions between ellipsoidal pores on the poroelasticity. To rule out any factors that can violate the Gassmann condition, other than elastic interactions, we first construct idealized models that contain only a single set of isolated, identical, and vertically aligned ellipsoidal pores. The numerical simulation suggests that the periodic distribution of ellipsoidal pores generate uniform pore pressure distribution, whereas random distribution of ellipsoidal pores generates heterogeneous pore pressure distributions. Then we analyze the precise conditions under which the underlying Gassmann relationship is valid for various inclusion‐based models. The results reveal the following: (1) Noninteracting effective medium theories are always consistent with the Gassmann prediction, simply because the elastic interactions are ignored. (2) The elastic interactions between randomly distributed pores cause heterogeneous pore pressure that violates the essential requirement of the Gassmann theory. The differential effective medium and self‐consistent approximation theories corresponding to this model thus are inconsistent with the Gassmann prediction. (3) The elastic interactions between periodically distributed pores cause uniform pore pressure; therefore, the Gassmann condition is fully satisfied. The T‐matrix approach explicitly takes into account such elastic interactions and thus is consistent with the Gassmann theory. It is interesting to notice that on top of other well‐known common types of heterogeneities, like pore structure or fluid heterogeneities, the distribution of pores and its associated elastic interactions can be a separate source of heterogeneity, and this makes Gassmann equations not valid anymore.
Magmatic and Sedimentary Structure beneath the Klyuchevskoy Volcanic Group, Kamchatka, From Ambient Noise Tomography
Authors: Green Robert G. , Sens‐Schönfelder Christoph , Shapiro Nikolai , Koulakov Ivan , Tilmann Frederik , Dreiling Jennifer , Luehr Birger , Jakovlev Andrey , Abkadyrov Ilyas , Droznin Dima , Gordeev Evgeny
Published: February 2020

The Klyuchevskoy Volcanic Group is a cluster of the world's most active subduction volcanoes, situated on the Kamchatka Peninsula, Russia. The volcanoes lie in an unusual off‐arc position within the Central Kamchatka Depression (CKD), a large sedimentary basin whose origin is not fully understood. Many gaps also remain in the knowledge of the crustal magmatic plumbing system of these volcanoes. We conducted an ambient noise surface wave tomography, to image the 3‐D shear wave velocity structure of the Klyuchevskoy Volcanic Group and CKD within the surrounding region. Vertical component cross correlations of the continuous seismic noise are used to measure interstation Rayleigh wave group and phase traveltimes. We perform a two‐step surface wave tomography to model the 3‐D Vsv velocity structure. For each inversion stage we use a transdimensional Bayesian Monte Carlo approach, with coupled uncertainty propagation. This ensures that our model provides a reliable 3‐D velocity image of the upper 15 km of the crust, as well as a robust assessment of the uncertainty in the observed structure. Beneath the active volcanoes, we image small slow velocity anomalies at depths of 2–5 km but find no evidence for magma storage regions deeper than 5 km—noting the 15 km depth limit of the model. We also map two clearly defined sedimentary layers within the CKD, revealing an extensive 8 km deep sedimentary accumulation. This volume of sediments is consistent with the possibility that the CKD was formed as an Eocene‐Pliocene fore‐arc regime, rather than by recent (<2 Ma) back‐arc extension.
Patterns and Dynamics of SST Fronts in the California Current System
Authors: Mauzole Y. L. , Torres H. S. , Fu L.‐L.
Published: February 2020

The California Current System (CCS) is one of the four major Eastern Boundary Current Systems, where major coastal upwelling is observed in the ocean. Oceanic fronts are abundant in the CCS, and are known to be associated with coastal upwelling. Analyses of satellite observations (altimetry and sea surface temperature, SST) of the CCS highlight the presence of SST fronts in the southern part of the CCS outside of the coastal upwelling season, which will be investigated. The submesoscale‐permitting and tidal‐resolving LLC4320‐simulation was used to analyze the nature of these features, through the study of the surface density gradients, the vertical velocities and the horizontal strain. An algorithm was also developed to track SST fronts in the model. The classical scenario of coastal upwelling is confirmed in the central CCS (off California), with a strain field correlated to vertical velocities associated with the SST fronts, and collocated density fronts. In contrast, in the southern CCS (off Baja California), vertical velocities were much weaker and density gradients were not always observed where SST fronts were detected, leading to the assumption that the fronts there may be affected by thermohaline compensation occurring in the region. These findings confirm the existence of SST fronts in the CCS outside of the traditional coastal upwelling framework, with part of the fronts in the southern CCS being passive and advected by the background flow.
Ground‐Based Observations Reveal Unique Valley Precipitation Patterns in the Central Himalaya
Authors: Ouyang Lin , Yang Kun , Lu Hui , Chen Yingying , Lazhu  , Zhou Xu , Wang Yan
Published: February 2020

While the Himalayas act as a natural barrier to water vapor transport to the Tibetan Plateau, many north‐south‐oriented valleys channel moisture onto the Plateau. However, owing to the lack of in situ data, the spatiotemporal characteristics of precipitation remain unclear along these valleys. In this study, a high‐altitude (2,800–4,500 m above mean sea level) rain‐gauge network was established in the Yadong Valley, one of the main valleys in the central Himalayan Region (CHR). New observations from this network are used to evaluate the Integrated Multi‐satellitE Retrieval for Global Precipitation Measurement (IMERG) precipitation product, with results demonstrating that the IMERG data can reproduce the seasonal and diurnal patterns of precipitation seen in the observational data. This combination of in situ and IMERG precipitation data reveals two unique characteristics in the CHR. First, precipitation during the premonsoon season (March‐May) contributes 20–40% of the annual total, from the high altitudes of the CHR to Southeast Tibetan Plateau, due to water vapor flux conveyed by southwesterlies from the Bay of Bengal, whereas this percentage is much lower in the northern Himalaya and South Asia. Second, diurnal variations in precipitation during the monsoon season (June‐September) vary between the low and high altitudes of the north‐south‐oriented valleys in the CHR: Precipitation at high altitudes has two peaks (one in the afternoon and the other at night), which is different from the single nighttime peak in low altitudes that is usually reported. These two notable spatiotemporal characteristics are indicative of the unique climate that exists at the high altitudes of the CHR.
Effects of Anthropogenic Activity on Global Terrestrial Gross Primary Production
Authors: Melnikova Irina , Sasai Takahiro
Published: February 2020

Gross primary production (GPP) has been identified as the largest terrestrial carbon flux and the major driver of the growing biosphere uptake of carbon. Factorial simulations using several biosphere models have been used to estimate the effects of long‐term (>50 years) climate change on global terrestrial GPP. However, no study has integrated large‐ensemble climate simulation data into a biosphere model to realistically estimate global terrestrial GPP with associated uncertainty. Here we present a novel approach to estimate the global terrestrial long‐term GPP with associated climate data‐induced uncertainty that combines a diagnostic‐type biosphere model with a large‐ensemble climate simulation data set. We distinguish the effects of recent anthropogenic activity on global GPP (the anthropogenic GPP effect) from the effects of interannual climate variability (the natural GPP effect) by comparing GPP model estimates forced by historical and “nonwarming” climate data. We provide evidence for an increasing anthropogenic effect on global terrestrial GPP. The anthropogenic GPP effect is driven by CO2 fertilization, which is projected to weaken or saturate by 2050–2150, depending on the representative concentration pathway scenario used. Model results suggest that shortwave radiation couples with El Niño–Southern Oscillation conditions and volcanic eruptions to drive the natural GPP effect. Because shortwave radiation at the surface is related to cloud cover, we encourage future studies to focus on cloud‐radiation feedbacks on the carbon cycle.
Crustal‐Scale Sheath Folding at HP Conditions in an Exhumed Alpine Subduction Zone (Tauern Window, Eastern Alps)
Authors: Groß Philip , Handy Mark R. , John Timm , Pestal Gerhard , Pleuger Jan
Published: February 2020

We investigate a well‐preserved paleo subduction channel that preserves a coherent part of the European continental margin exposed in the central Tauern Window (Eastern Alps), with the aim of testing models of sheath fold nappe formation and exhumation. The subduction zone was active during Paleogene convergence of the European and Adriatic plates, after closure of the Alpine Tethyan ocean. New cross sections and structural data together with new petrological data document a recumbent, tens of kilometers‐scale sheath fold in the center of the Tauern Window that formed during pervasive top‐foreland shear while subducted at high‐pressure (HP) conditions (~2.0 GPa, 500 °C) close to maximum burial depth. The fold comprises an isoclinally folded thrust that transported relicts of the former Alpine Tethys onto a distal part of the former European continental margin. The passive margin stratigraphy is still well preserved in the fold and highlights the special character of this segment of the European continental margin. We argue that this segment formed a promontory to the margin, which was inherited from Mesozoic rifting. In accordance with classical sheath fold theory, this promontory may have acted as an initial structural perturbation to nucleate a fold that was passively amplified to a sheath fold during top‐foreland shear in the subduction zone. The fold was at least partly exhumed and juxtaposed with the surrounding lower pressure units by opposing top‐hinterland and top‐foreland shear zones above and below, respectively, that is, in the sense of a nappe fold formed during channel‐extrusion exhumation.
Diagnostic Analysis of Bank Storage Effects on Sloping Floodplains
Authors: Liang Xiuyu , Zlotnik Vitaly A. , Zhang You‐Kuan , Xin Pei
Published: February 2020

Stream bank storage effects during floods have received limited attention, despite the significant role of such floods in aquifer water budgets. One reason is the complexity of geometry of the problem, which commonly has been treated numerically. Using a simple model in a domain with moving boundary, a semianalytical solution for bank storage effects is proposed to account for stream stage hydrograph, floodplain slope, and aquifer parameters. The results extend classic solutions by Cooper and Rorabaugh (1963, https://doi.org/10.3133/wsp1536J) for idealized vertical streambanks but applied to realistic floodplain cross sections. The accuracy of the semianalytical solution is verified by a one‐dimensional numerical method and compared to a vertical two‐dimensional variably saturated‐flow numerical model. Comparison indicates that a robust solution is valid for diagnostic analyses of modeling bank storage effects on floodplains. The semianalytical solution is applied to laboratory experiments as well. The results indicate that the present solution provides reasonable estimates of peak timing and head of groundwater flow response in the sloping bank during varying stream stage.
What Causes the Postmonsoon 18O Depletion Over Bay of Bengal Head and Beyond?
Authors: Cai Zhongyin , Tian Lide
Published: February 2020

Modern observations from Bay of Bengal (BOB) head have shown that precipitation δ18O value reaches the lowest stage during late postmonsoon when the summer monsoon has weakened or retreated, complicating the traditional interpretation of low δ18O value as strong monsoon. We show that this postmonsoon 18O depletion phenomenon exists from BOB periphery to the southeast and south Tibetan Plateau. Accumulative precipitation along back‐trajectory still explains daily precipitation δ18O variability during both the monsoon and nonmonsoon, thus indicating that longer‐term weighted‐mean δ18O is biased toward synoptic conditions during precipitation events. Further, we propose that transport of moisture from the east (west) of the India‐Burma Trough leads to depleted (enriched) 18O during the postmonsoon (premonsoon). Our results reconcile the apparent contradiction but beg the consideration of potential bias and influence of different precipitation regimes in paleo archives.
Single-agent activity of phosphatidylinositol 3-kinase inhibition with copanlisib in patients with molecularly defined relapsed or refractory diffuse large B-cell lymphoma
Authors: Lenz Georg , Hawkes Eliza , Verhoef Gregor , Haioun Corinne , Thye Lim Soon , Seog Heo Dae , Ardeshna Kirit , Chong Geoffrey , Haaber Jacob , Shi Wei , Gorbatchevsky Igor , Lippert Susanne , Hiemeyer Florian , Piraino Paolo , Beckmann Georg , Peña Carol , Buvaylo Viktoriya , Childs Barrett H. , Salles Gilles
Published: February 2020

Patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) have adverse outcomes. We evaluated the efficacy and safety of the phosphatidylinositol 3-kinase inhibitor copanlisib in patients with relapsed/refractory DLBCL and assessed the relationship between efficacy and DLBCL cell of origin (COO; activated B-cell like [ABC] and germinal center B-cell like [GCB]) and other biomarkers. The primary endpoint was objective response rate (ORR) in DLBCL COO subgroups (ABC, GCB, and unclassifiable) and by CD79B mutational status (NCT02391116). Sixty-seven patients received copanlisib (ABC DLBCL, n = 19; GCB DLBCL, n = 30; unclassifiable, n = 3; missing, n = 15). The ORR was 19.4%; 31.6% and 13.3% in ABC and GCB DLBCL patients, respectively. ORR was 22.2%/20.0% for patients with/without CD79B mutations (wild type, n = 45; mutant, n = 9; missing, n = 13). Overall median progression-free survival and duration of response were 1.8 and 4.3 months, respectively. Adverse events included hypertension (40.3%), diarrhea (37.3%), and hyperglycemia (32.8%). Aberrations were detected in 338 genes, including BCL2 (53.7%) and MLL2 (53.7%). A 16-gene signature separating responders from nonresponders was identified. Copanlisib treatment demonstrated a manageable safety profile in patients with relapsed/refractory DLBCL and a numerically higher response rate in ABC vs. GCB DLBCL patients.
Sarcodon aspratus polysaccharides ameliorated obesity-induced metabolic disorders and modulated gut microbiota dysbiosis in mice fed a high-fat diet
Authors: Chen Juan , Liu Jiaojiao , Yan Chenchen , Zhang Chan , Pan Wenjuan , Zhang Wenna , Lu Yongming , Chen Lei , Chen Yan
Published: February 2020

The polysaccharides isolated from the fruit body of S. aspratus (SATPs) might be a potential health supplement or prebiotic in the prevention of obesity and associated metabolic disorders.
Mulberry leaf polyphenols attenuated postprandial glucose absorptionviainhibition of disaccharidases activity and glucose transport in Caco-2 cells
Authors: Li Qian , Wang Chen , Liu Fan , Hu Tenggen , Shen Weizhi , Li Erna , Liao Sentai , Zou Yuxiao
Published: February 2020

The present study attempted to evaluate the mechanism of action and bioactivity of mulberry leaf polyphenols (MLPs) in type-2 diabetes preventionviainhibition of disaccharidase and glucose transport.
Glycyrrhizin inhibits osteoarthritis development through suppressing the PI3K/AKT/NF-κB signaling pathway in vivo and in vitro
Authors: Jiang Ren-Hao , Xu Jia-Jing , Zhu Ding-Chao , Li Jia-Feng , Zhang Chen-Xi , Lin Nan , Gao Wei-Yang
Published: February 2020

Osteoarthritis (OA) is a serious and frequently occurring disease in the elderly, characterized by cartilage degeneration and proliferation of bone structure.
Facile synthesis of hierarchical Ni7S6 and Co(ii)-doped Ni7S6 flower structures for high-performance supercapacitors
Authors: Zhang Daojun , Fu Xueying , Zhang Xiaobei , Li Chengxiang , Bian Hao , Zhang Xinyu , Cao Zhi , Zhang Renchun , Zhang Jingchao
Published: February 2020

The as-prepared flower-like Ni7S6 structure with abundant surface active sites demonstrated good supercapacitor performance in an alkaline solution.
Hexafluorosilicate anion in the formation of a coordination cage: anion competition
Authors: Lee Jeyeong , Park Seonghyeon , Kim Dongwon , Lee Young-A , Jung Ok-Sang
Published: February 2020

The construction of a coordination cage in a system of dual anions including hexafluorosilicate was investigated. Significant catalytic effects on catechol oxidation catalysis performance ranks among the most efficient yet recorded.
Defect repair of tin selenide photocathode via in situ selenization: enhanced photoelectrochemical performance and environmental stability
Authors: Wang Ruilun , Lyu Yanhong , Du Shiqian , Zhao Shiyong , Li Hao , Tao Li , Jiang San Ping , Zheng Jianyun , Wang Shuangyin
Published: February 2020

In situ selenization is a potential method to repair the defects of metal selenide films for enhancing their photoelectrochemical performance and environmental stability.
Influences of niobium pentoxide on roughness, hydrophilicity, surface energy and protein absorption, and cellular responses to PEEK based composites for orthopedic applications
Authors: Ge Junpeng , Wang Fan , Xu Zhiyan , Shen Xuening , Gao Chao , Wang Dongliang , Hu Gangfeng , Gu Jinlou , Tang Tingting , Wei Jie
Published: February 2020

PNCs prepared by pressing–sintering exhibited improved surface properties and excellent cellular responses.
A novel amphiphilic oligopeptide induced the intrafibrillar mineralisationviainteracting with collagen and minerals
Authors: Wang Qing-qing , Miao Leiying , Zhang He , Wang Si Qing , Li Quanli , Sun Weibin
Published: February 2020

The self-assembled oligopeptide inspired by CEMP1 achieved collagen mineralisation by binding with collagen and attracting calcium ions.
Evolutional carrier mobility and power factor of two-dimensional tin telluride due to quantum size effects
Authors: Li Yu , Ding Teng , Sang David K. , Wu Mengnan , Li Junqin , Wang Cong , Liu Fusheng , Zhang Han , Xie Heping
Published: February 2020

Layer-dependent transport behaviour and thermoelectric performance of 2D SnTe layered materials.
Recent progress in silver nanowire networks for flexible organic electronics
Authors: Li Wenting , Zhang Huan , Shi Shengwei , Xu Jinxin , Qin Xin , He Qiqi , Yang Kecong , Dai Wubin , Liu Gang , Zhou Quanguo , Yu Huangzhong , Silva S. Ravi P. , Fahlman Mats
Published: February 2020

Silver nanowires for flexible organic electronics have been comprehensively summarized from synthesis, film fabrication, characterization and applications to perspectives.
Interlaced Pd–Ag nanowires rich in grain boundary defects for boosting oxygen reduction electrocatalysis
Authors: Liu Xiao-Jing , Yin Xing , Sun Yi-Dan , Yu Feng-Jiao , Gao Xiang-Wen , Fu Li-Jun , Wu Yu-Ping , Chen Yu-Hui
Published: February 2020

Pd–Ag interlaced nanowires with grain boundary defect engineering exhibit enhanced activity and superior stability for oxygen reduction reaction in alkaline media.
Severity detection tool for patients with infectious disease
Authors: Tadesse Girmaw Abebe , Zhu Tingting , Le Nguyen Thanh Nhan , Hung Nguyen Thanh , Duong Ha Thi Hai , Khanh Truong Huu , Van Quang Pham , Tran Duc Duong , Yen Lam Minh , Van Doorn Rogier , Van Hao Nguyen , Prince John , Javed Hamza , Kiyasseh Dani , Van Tan Le , Thwaites Louise , Clifton David A.
Published: February 2020

Hand foot and mouth disease (HFMD) and tetanus are serious infectious diseases in low‐ and middle‐income countries. Tetanus, in particular, has a high mortality rate and its treatment is resource‐demanding. Furthermore, HFMD often affects a large number of infants and young children. As a result, its treatment consumes enormous healthcare resources, especially when outbreaks occur. Autonomic nervous system dysfunction (ANSD) is the main cause of death for both HFMD and tetanus patients. However, early detection of ANSD is a difficult and challenging problem. The authors aim to provide a proof‐of‐principle to detect the ANSD level automatically by applying machine learning techniques to physiological patient data, such as electrocardiogram waveforms, which can be collected using low‐cost wearable sensors. Efficient features are extracted that encode variations in the waveforms in the time and frequency domains. The proposed approach is validated on multiple datasets of HFMD and tetanus patients in Vietnam. Results show that encouraging performance is achieved. Moreover, the proposed features are simple, more generalisable and outperformed the standard heart rate variability analysis. The proposed approach would facilitate both the diagnosis and treatment of infectious diseases in low‐ and middle‐income countries, and thereby improve patient care.
Survey on health care applications in 5G networks
Authors: Liu Enjie , Effiok Emmanuel , Hitchcock Jon
Published: February 2020

In 2019, 5G was introduced and it is being gradually deployed all over the world. 5G introduces new concepts, such as network slicing to better support various applications with different performance requirements on data rate and latency; and edge and cloud computing that will be responsible for the leverage of computational requirements. This study aims to describe the functions and features of the key 5G technologies and conduct a survey on the latest development of driving technologies for 5G. This survey focuses on health care applications that would benefit from the advantages brought by 5G.
DOA estimation method of electronically controlled beam‐scanning LWA based on ESPRIT algorithm
Authors: Ma Shuang , Meng Fan‐Yi , Jin Tao , Fu Jia‐Hui , Wu Qun
Published: February 2020

A novel direction‐of‐arrival (DOA) estimation method based on electronically controlled beam scanning leaky‐wave antenna (LWA) combined with estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm is proposed. In order to implement this method, a virtual partial pattern synthesis method is presented to construct an array manifold of subarrays from LWA for the ESPRIT algorithm. Then, the multi‐channel receiver model and signal subspace are established based on the beam scanning property of LWA. As the traditional array antenna is substituted by LWA, the rotation operator of the algorithm has to be changed. From this point, the preprocessing ESPRIT algorithm based on the Hadamard product is proposed to extract the directional matrix of LWA. Numerical simulations are conducted, and the DOA performance is demonstrated through estimation error, response rate, and compared with the Cramer‐Rao bound. Simulation results show that the DOA method utilising LWA exhibits satisfactory estimation performance and fast response speed. In addition, the influence of antenna parameters on the estimation accuracy and the method to improve the performance of DOA estimation for LWA are discussed.
Compact single‐ and dual‐band bandpass filters with controllable transmission zeros using dual‐layer dual‐mode loop resonators
Authors: Liu Qing , Zhang Dewei , Zhang Junjie , Zhou Dongfang , An Na
Published: February 2020

An unbalanced microstrip bandpass filter (BPF) in dual‐extended doublet topology with source‐load (S‐L) coupling is first presented and researched based on dual‐layer capacitive‐loaded dual‐mode loop resonators. The input and output ports are located on the upper substrate layer. The lower dual‐mode loop resonator is coupled to the upper loop resonator using four coupling apertures in the middle metal layer. Single‐ and dual‐band responses with four controllable finite‐transmission zeros (FTZs) are analysed. Then, a balanced BPF in dual‐extended doublet topology without S‐L coupling on the basics of the proposed unbalanced filter is presented and researched. Single‐ and dual‐band differential mode responses with three controllable FTZs can be realised with good common mode suppression. Some design examples are provided to illustrate the performances of the realised single‐ and dual‐band unbalanced and balanced filters with controllable FTZs. The measured results agree well with simulated ones.
Differentially fed six‐beam switchable reconfigurable antenna
Authors: Jin Gui‐Ping , Li Miao‐Lan , Xu Ye‐Chun , Yang Ju , Liao Shao‐Wei
Published: February 2020

Differentially fed six‐beam switchable reconfigurable antenna is proposed in this study. The antenna consists of radiators, parasitic elements, cross‐shaped feeding network and the ground plane. The radiators are formed by two pairs of gear‐shaped cross dipoles. By changing the excitation differential ports to drive one of two pairs of dipoles, and by enabling different reflectors, the beam can be switched to point to six different directions with different zenith and azimuth angles. For all the beam directions, the proposed antenna can obtain −10 dB differential reflection coefficient of 20.8% operating from 3.01 to 3.76 GHz, a high average gain of 7.6 dBi and radiation efficiency of 80%.
5G camouflage antenna for pico‐cell base stations
Authors: Alieldin Ahmed , Huang Yi , Stanley Manoj , Xu Qian
Published: February 2020

A camouflage dual‐polarised antenna for 5G pico‐cell (PC) base stations is proposed in this study. The antenna offers good coverage for the 5G sub‐6 GHz frequency band (3.3–3.8 GHz) with a reflection coefficient better than −15 dB and a port‐to‐port coupling less than −23 dB. The proposed antenna consists of two layers (a radiating layer and a feeding layer) separated by an air gap. The radiating layer uses a transparent conducting film (indium tin oxide) to form two patches (a radiating patch and a parasitic patch) printed on the opposite sides of a glass laminate. The radiating layer has visual transparency of 77%, which makes it possible to be integrated with the glass cover of the head of a street lamp while the feeding layer is embedded inside the head for camouflage. A 2 × 2 antenna array is formed to achieve a realised gain of 13.2 dBi and a 3‐dB solid angle of 33° × 33°. Therefore, the proposed design is very suitable to be employed as a camouflage 5G PC base station.
Three‐dimensional profiling of collimated radio‐frequency orbital angular momentum beams
Authors: Hamilton Joshua K. , Berry Simon J. , Spencer Joseph H. , Lawrence Christopher R. , Smith Francis C. , Drysdale Timothy D.
Published: February 2020

The use of orbital angular momentum (OAM) modes in radio communication is thought to enhance capacity. This work focuses on using the l = +1 mode transmitted from a 180 mm diameter, 8‐element circular antenna array. The transmitted OAM beam was collimated by using a spherical mirror and the intensity and phase were investigated. A xyz scanning stage was used to profile the propagating OAM beam in three dimensions, resulting in a detailed investigation into the effects of collimation on the OAM beam. The proposed system was shown to reduce the beam divergence from 36.6° to 1.2°, without affecting the OAM mode purity of the beam for a frequency range of 4–6 GHz. This investigation showed a step towards realising practical control over the divergence of OAM‐carrying beams.
Stacked frequency reconfigurable Yagi‐like MIMO antenna system
Authors: Hussain Rifaqat , Jehangir Syed S. , Khan Muhammad U. , Sharawi Mohammad S.
Published: February 2020

In this work, a 2‐layer frequency reconfigurable Yagi‐like multiple‐input–multiple‐output (MIMO) antenna system is proposed based on a closed pentagonal slot‐loop excitation. The MIMO system consists of 4 identical active antenna elements reactively loaded with varactor diodes to achieve frequency reconfigurability over a band from 1.5 to 2.1 GHz. The distinguishing feature of the proposed work is achieving Yagi‐like directional characteristics over a very wide frequency band. The conventional omni‐directional pattern of a slot antenna is made directional by using a parasitic metallic reflector layer below the substrate. By using the reflector element, the back‐lobe radiation is highly suppressed and a front‐to‐back ratio of 5–13 dB is achieved within the entire frequency band of operation. The proposed design is compact with an overall size of , and a reflector size of . A single element has a maximum peak gain of 4 dBi and total measured radiation efficiency of 76%. The antenna system also shows good MIMO performance with high port isolation of 11.3 dB and very low envelope correlation coefficient values within the operational band.
Inrush current reduction technology of DAB converter for low‐voltage battery systems and DC bus connections in DC microgrids
Authors: Kwak Bongwoo , Kim Myungbok , Kim Jonghoon
Published: February 2020

Low‐voltage battery energy storage system and dual active bridge (DAB) converter control method for DC bus connection in DC microgrid. To use power efficiently in a DC microgrid, power must be easily transferred in both directions. DAB converters can easily transfer power in both directions using only the phase shift of the gate at 50% fixed duty on the primary and secondary sides. In the transient state, however, an overcurrent occurs to charge the output capacitor. A soft start algorithm is used to overcome this overcurrent problem. In the conventional method, the control complexity and response characteristics are slow because the duty control is included and the algorithm is performed in several stages. In this study, a gate drive circuit is constructed using a pulse transformer for 50% fixed duty control and short circuit protection. A soft start control algorithm is proposed, including a first‐order phase shift scheme for the stable soft start at 50% fixed duty. The 3 kW prototype DAB converter is designed and implemented for bidirectional power conversion testing. The experimental results show that stable power transfer is achieved in the initial transient state through bidirectional output control and soft start.
Charging/discharging system based on zeta/sepic converter and a sliding mode controller for dc bus voltage regulation
Authors: Henao‐Bravo Elkin Edilberto , Saavedra‐Montes Andres Julian , Ramos‐Paja Carlos Andres , Bastidas‐Rodriguez Juan David , Gonzalez Montoya Daniel
Published: February 2020

This study proposes a charging/discharging system of energy storage devices (ESDs) to regulate the voltage of a dc bus. The proposed charging/discharging system is formed by a zeta/sepic converter and a sliding mode controller (SMC). The SMC uses a single sliding surface to regulate the dc bus voltage for the three operating modes of the charger/discharger converter (charging, discharging, and stand‐by) and for ESD voltages lower, equal, or higher than the dc bus voltage. This study includes the stability analysis of the SMC and a design procedure of the SMC parameters. The charging/discharging system is simulated in PSIM, where the results confirm that the proposed SMC regulates the bus voltage in charging, discharging, and stand‐by modes for different operating points of the system. Finally, the proposed charging/discharging system was constructed for demonstrating the feasibility of the solution for real applications. Moreover, the experimental results obtained in such a platform put into evidence the accuracy of the proposed SMC in regulating the bus voltage in all the possible conditions: bus voltage lower, equal or higher than ESD voltage, and during charge, discharge, and stand‐by modes of the ESD.
Modelling and optimisation of a dual‐control MHz‐level CLLC converter with minimised power losses in battery charging applications
Authors: Zhang Zeyu , Khaligh Alireza
Published: February 2020

In this study, a novel ‘’ dual‐control modulation is proposed for the MHz‐level CLLC converters in battery charging applications. Phase shift between the primary and secondary switches is utilised as an additional control variable to effectively reduce the power losses, especially in light‐ and medium‐load conditions. Compared to other state of the art, a more generalised theoretical model is developed to characterise the converter with higher accuracy based on extended harmonic approximation. Furthermore, a numerical algorithm is utilised to thoroughly examine the converter performance under various operating conditions and systematically search for the optimised design parameters under the proposed modulation scheme. The modelling and optimisation are verified by simulation on a 3.3 kW onboard charger design for electric vehicles, which shows an estimated efficiency enhancement between 1 and 4%. Finally, a laboratory prototype has been developed using gallium nitride semiconductor devices, at the resonant frequency of 1 MHz. The converter measured efficiencies are 96.4, 96.2 and 94% for the selected heavy, medium‐ and light‐load conditions, respectively. This system would allow insights into the practical implementation and evaluation of utilising wide bandgap semiconductors to achieve both high power density and enhanced efficiency for emerging power electronic systems.
Dual range flyback topology for high efficiency at dual voltage mains
Authors: Ezra Noam , Long Teng
Published: February 2020

This study introduces a dual range flyback converter, which overcomes low efficiency of the conventional flyback converter for universal mains voltages, i.e. 220 and 110 V AC mains. The topology comprises of reconfigurable primary power loops enabled by additional state switches. This combination allows the converter to run in parallel or series modes, enhancing the performance at 220 V AC high line or 110 V AC low line mains. It reduces the voltage rating of devices, supports two working points that operate in boundary conduction mode under fixed frequency and improves the utilisation of the devices. A 100 kHz, 60 W, 110 V AC or 220 V AC to 13 V DC converter has been designed and tested. The experimental results of the proposed converter have been compared against a conventional flyback converter. The results show a small improvement of performance at low voltage (110 V AC) and considerable performance improvement at high voltage (230 V AC): 0.6 and 2.3% efficiency improvement at full load, respectively.
Closed‐form complex permeability expression for proximity‐effect homogenisation of litz‐wire windings
Authors: Niyomsatian Korawich , Gyselinck Johan , Sabariego Ruth V.
Published: February 2020

The eddy‐current losses in litz‐wire windings are mostly due to the proximity effect, which can be macroscopically modelled via a complex frequency‐dependent permeability. In this study, the authors propose a new closed‐form expression for this complex permeability. Results are compared with approximations found in the literature in a wide‐frequency range. For the sake of validation, a two‐dimensional)‐axisymmetric gapped transformer with litz‐wire primary and secondary coils is studied.