bluuebunny/crossref_metadata_2025 huggingface dataset:
Contrasting trends between species and catchments in diadromous fish counts over the last 30 years in France
Authors: Legrand Marion , Briand Cédric , Buisson Laëtitia , Artur Gwenaël , Azam Didier , Baisez Aurore , Barracou David , Bourré Nicolas , Carry Laurent , Caudal Anne-Laure , Charrier Fabien , Corre Jérémie , Croguennec Eric , Der Mikaélian Sophie , Josset Quentin , Le Gurun Laëtitia , Schaeffer Frédéric , Laffaille Pascal
Published: January 2020

The decline and collapse of populations have been reported for a large range of taxa. Diadromous fishes migrate between fresh water and the sea and encounter many anthropogenic pressures during their complex life cycle. In spite of being of ecological, cultural and economic interest, diadromous fishes have been in decline for decades in many parts across the world. In this study, we investigated the change in five diadromous fish counts in France over a 30-year period using 43 monitoring stations located in 29 rivers across 18 catchments. Our hypothesis was that the counts of these species evolved in a contrasting way between catchments. We also tested the effect of five drivers potentially contributing to the observed trends: catchment, latitude, presence of commercial fisheries, improvement of ecological continuity and salmon stocking. We found contrasting trends in fish counts between species at the national scale, with some taxa increasing (Anguilla anguillaandSalmo trutta), some showing a slight increase (Salmo salar) and some decreasing (Alosaspp. andPetromyzon marinus). For each taxon, exceptAnguilla anguilla, we highlighted a significant catchment effect indicating contrasting trends between catchments and stations. However, we found no significant effect of catchment characteristics for any of the studied taxa.
Analysis of leptin concentrations in oral fluids (saliva and crevicular gingival fluid) and blood in patients with chronic periodontal disease: systematic review of literature
Authors: Caillet Julia , Mignan Solène , Pham-Dang Nathalie , Devoize Laurent
Published: January 2020

Objective: The objective of this systematic analysis was to perform a qualitative and quantitative synthesis of the literature concerning salivary and serum leptin variations in patients with chronic periodontitis (CP) compared with healthy subjects. Saliva leptin concentration analysis could be a relevant and non-invasive biological test for the evaluation of periodontal disease in both medical and clinical trials, beyond the clinical and radiographic elements. Material and Method: Querying the PubMed and Web of Science databases identified articles that met our inclusion criteria. Quantitative analysis of the literature data was performed with the Review Manager 5.3 software. Results: The qualitative analysis included 14 articles and showed a decrease of salivary leptin (5 studies out of 5) and an increase of serum leptin (11 of 12 studies) in patients with CP compared to unaffected subjects of CP. Quantitative analysis was performed on 4 trials. For salivary leptin, we confirmed a decrease in its level in patients with CP with a standardized mean difference (SMD) of −2.27, 95% CI [−2.68, −1.86]. The difference was highly significant but we detected a very important heterogeneity in this dataset (I2 = 94%). For serum leptin, we also confirmed an increase in its rate in patients with CP with an SMD of 2.18, 95% CI [1.75, 2.61]. The difference was highly significant but the heterogeneity measured in this dataset was also too high (I2 = 95%). Conclusion: The current level of evidence was insufficient to assert an increase in serum leptin and a decrease in salivary leptin in CP patients compared to healthy controls due to a great heterogeneity of the values measured in the studies.
Development and production of large blast furnaces from 2015 to 2016 in China
Authors: Dai Bing , Long Hong-ming , Wen Yong-cai , Ji Yi-long , Liu Yun-cai
Published: January 2020

This article has reviewed the production status, total reductant consumption, raw materials and operation principle indexes of large blast furnaces in China from 2015 to 2016. The developing actuality of Chinese large BFs has been quantitatively analyzed and the existing problems have been proposed clearly. Based on that, maintaining production stable, enhancing the quality of raw materials and improving the operation principles are suggested. Large BFs take advantages of high-quality hot metal, energy saving, cost-cutting, high mechanization and automation levels and are sufficient to meet the challenges of economic crisis, environmental pressure and security risk form the future. Thus, the number of large BFs in China will continue to increase in the future.
Weldability of S700MC steel welded with the hybrid plasma + MAG method
Authors: Skowrońska Beata , Chmielewski Tomasz , Golański Dariusz , Szulc Jacek
Published: January 2020

The paper describes the microstructure of welded joints produced by the plasma+MAG (Metal Active Gas) method of S700MC high yield strength steel (700 MPa). Welded joints of thermomechanical steel have been made with different values of heat input. The results of metallographic research of welded joints, microstructure of the weld and heat affected zone, hardness distribution and impact toughness are presented. The heat affected zone consists of two sub-zones with different grain size and lowered hardness. The tensile test show that strength of welded joints was slightly reduced and the bending test revealed no crack formation in the weld. The impact toughness of measured welded samples with V-notch in HAZ (heat affected zone) reached high values that are higher comparing to samples with notch placed in the weld area. The investigation results show that the use of plasma concentrated heat source together with MAG welding arc does not significantly change the structure and deteriorate properties of welded S700MC thermomechanically treated high strength steel. The hybrid plasma+MAG welding method has a potential to become a beneficial alternative to other welding processes due to its high efficiency, reduced amount of weld metal content or limited requirements for a preparation of edges of welded joints.
A global climatological model of extreme geomagnetic field fluctuations
Authors: Rogers Neil C. , Wild James A. , Eastoe Emma F. , Gjerloev Jesper W. , Thomson Alan W. P.
Published: January 2020

This paper presents a multi-parameter global statistical model of extreme horizontal geomagnetic field fluctuations (dBH/dt), which are a useful input to models assessing the risk of geomagnetically induced currents in ground infrastructure. Generalised Pareto (GP) distributions were fitted to 1-min measurements of |dBH/dt| from 125 magnetometers (with an average of 28 years of data per site) and return levels (RL) predicted for return periods (RP) between 5 and 500 years. Analytical functions characterise the profiles of maximum-likelihood GP model parameters and the derived RLs as a function of corrected geomagnetic latitude,λ. A sharp peak in both the GP shape parameter and the RLs is observed at |λ| = 53° in both hemispheres, indicating a sharp equatorward limit of the auroral electrojet region. RLs also increase strongly in the dayside region poleward of the polar cusp (|λ| > 75°) for RPs > 100 years. We describe how the GP model may be further refined by modelling the probability of occurrences of |dBH/dt| exceeding the 99.97th percentile as a function of month, magnetic local time, and the direction of the field fluctuation,dBH, and demonstrate that these patterns of occurrence align closely to known patterns of auroral substorm onsets, ULF Pc5 wave activity, and (storm) sudden commencement impacts. Changes in the occurrence probability profiles with the interplanetary magnetic field (IMF) orientation reveal further details of the nature of the ionospheric currents driving extreme |dBH/dt| fluctuations, such as the changing location of the polar cusp and seasonal variations explained by the Russell-McPherron effect.
Critical Care EEG
Authors: Koren Johannes , Herta Johannes , Baumgartner Christoph
Published: January 2020

Neuromonitoring mittels kontinuierlichem EEG (cEEG) kommt bei intensivpflichtigen Patienten immer häufiger zur Anwendung. Mithilfe standardisierter EEG-Kriterien können nichtkonvulsive Anfälle bzw. Status epileptici sowie rhythmische und periodische EEG-Muster unklarer Wertigkeit („ictal-interictal continuum“) verlässlich detektiert und unterschieden werden. Ebenso können mittels cEEG zerebrale Ischämien frühzeitig detektiert, sowie Sedierungs- und Therapiemanagement überwacht und gesteuert werden.
Eyewear for Rugby Union: Wearer Characteristics and Experience with
Rugby Goggles
Authors: Little Julie-Anne , Eckert Fabienne , Douglas Marc , Barrett Brendan T.
Published: January 2020

Unlike many other sports, Rugby Union has not permitted players to wear
spectacles or eye protection. With an industrial partner, World Rugby developed
goggles suitable for use while playing rugby for the purposes of growing
participation amongst those that need to wear corrective lenses. This study
reports on the profile and experiences of goggle wearers. 387 players received
the goggles. Data were obtained from 188 (49%) using an online, 75-item
questionnaire. 87% “strongly agreed/agreed” that
goggles are beneficial and 75% are happy with goggle performance. Common
problems reported by 49.7 and 32.6% of respondents were issues with
fogging-up and getting dirty. 15 (8%) players stopped wearing the
goggles because of fogging-up, limits to peripheral vision and poor
comfort/fit. Injuries were reported in 3% of respondents. In
none of these cases did the player stop wearing the goggles. From the positive
experience of players in the trial, the goggles were adopted into the Laws of
the game on July 1, 2019. As the need to correct vision with spectacles is
common, and contact lenses are not worn by 80%+of spectacle
wearers, the new Rugby goggles will widen participation for those that need to
wear refractive correction, or have an existing/increased risk of
uniocular visual impairment.
Synthesis of Spirocyclic Amines by 1,3-Dipolar Cycloaddition of Azomethine Ylides and Azomethine Imines
Authors: Choi Anthony , Castle Jemma , Saruengkhanphasit Rungroj , Coldham Iain
Published: January 2020

Simple ketone starting materials with a halide leaving group and an alkene were prepared in one step and heated with glycine or glycine esters to promote a tandem imine formation, cyclization, and dipolar cycloaddition cascade. The chemistry was also feasible with acetylhydrazide. In each case a single stereoisomer of the tricyclic amine or pyrazolidine product was formed and the stereochemistry was verified by single crystal X-ray diffraction. When the reaction with glycine, which occurs with loss of CO2, was unsuccessful, the cascade process could be promoted by cross metathesis to give the vinyl sulfone starting material that provides a more reactive dipolarophile. Reductive cleavage of the pyrazolidine gave a spirocyclic diamine product.
Preeclampsia: The Need for a Biological Definition and Diagnosis
Authors: Vidaeff Alex C. , Saade George R. , Sibai Baha M.
Published: January 2020

The centuries-old approach to the prevention of eclampsia and its associated maternal morbidity and mortality is based on the recognition of the presence of premonitory signs and symptoms such as hypertension and proteinuria. The spectrum of preceding signs and symptoms came to be known as preeclampsia, which is debatably considered to be an early stage on a clinical continuum possibly leading to eclampsia. The premonitory signs and symptoms were then construed as diagnostic criteria for the poorly understood syndrome of preeclampsia, and this led to a perpetual debate that remains subject to wide disagreement and periodic updates. In this commentary, we will draw attention to the fact that the criteria for preeclampsia should be viewed from the prism of a screening test rather than as diagnostic of a condition in itself. Focusing research on developing better diagnostic and screening methods for what is clinically important, namely maternal and perinatal morbidity and mortality from hypertensive disorders of pregnancy, a long overdue upgrade from what was possible centuries ago, will ultimately lead to better management approaches to what really matters.
Acute Kidney Injury in Neonates with Perinatal Asphyxia Receiving Therapeutic Hypothermia
Authors: Bozkurt Ozlem , Yucesoy Ebru
Published: January 2020

Objective To assess the incidence and severity of acute kidney injury (AKI) and evaluate risk factors that predict AKI in asphyxiated infants receiving therapeutic hypothermia.

Study Design Infants ≥36 weeks' gestation diagnosed with moderate-to-severe perinatal asphyxia and received therapeutic hypothermia were reviewed retrospectively (n = 166). Modified Acute Kidney Injury Network criteria were used to diagnose AKI. The results of infants with AKI were compared with the infants who did not develop AKI.

Results AKI developed in 49 (29.5%) infants, of whom 22 had stage I, 13 had stage II, and 14 had stage III AKI. The overall mortality rate was 15.7% and was significantly higher in infants with AKI when compared with infants without AKI (41 vs. 5%; p < 0.001). Asystole at birth (p = 0.044), placental abruption (p = 0.041), outborn status (p = 0.041), need for vasopressor support (p = 0.031), increased bleeding tendency (p = 0.031), initial lactate level (p = 0.015), and 12-hour lactate level (p = 0.029) were independent risk factors for the development of AKI. Receiver operating characteristic curve analysis demonstrated a good predictive value for initial lactate level (>15 mmol/L), with 69% sensitivity (95% CI: 55–82) and 82% specificity (95% CI: 74–89), and for 12-hour lactate level (>6 mmol/L), with 83.7% sensitivity (95% CI: 70–93) and 73.5% specificity (95% CI: 64.5–81), to predict AKI.

Conclusion AKI is still a common complication of perinatal asphyxia despite treatment with therapeutic hypothermia. Identification of risk factors associated with the development of AKI in asphyxiated infants would be potentially beneficial to reduce morbidity and mortality. Besides perinatal risk factors, initial and 12-hour lactate concentrations can be used for the early prediction of AKI.
Is Vascularized Composite Allograft Transplantation Experimental or an Accepted Surgical Procedure: Results from a National Survey
Authors: Colakoglu Salih , Tebockhorst Seth , Mathes David Woodbridge
Published: January 2020

Background More than 85 patients have received over 100 hand/arm transplants and more than 35 patients have received full or partial face transplants at institutions around the world. Given over two decades of experience in the field and in the light of successful outcomes with up to 17 years follow up time, should we still consider vascularized composite allograft (VCA) as a research/clinical investigation? We present the results of a nationwide electronic survey whose intent was to gather institutional bias with regard to this question.

Methods An 11 question survey that was developed by VCA advisory committee of American Society of Transplantation was sent to all identified Internal Review Board chairs or directors in the United States.

Results We received a total of 54 responses (25.3%) to the survey. The majority (78%) of responses came from either the chairperson, director, or someone who is administratively responsible for an IRB.

Conclusion Though certainly not an exhaustive investigation into each institution's preference, we present a representative sampling. The results of which favor VCA as an accepted clinical procedure given the appropriate setting. Further research is needed to fully ascertain practices at each individual institution.
Anterior Ethmoidal Artery: A Computed Tomography Analysis and New Classifications
Authors: El-Anwar Mohammad Waheed , Khazbak Alaa Omar , Eldib Diaa Bakry , Algazzar Hesham Youssef
Published: January 2020

Objective to determine the anterior ethmoidal artery (AEA) anatomy and variations by computed tomography (CT) in adult and their relations to and presents new AEA classifications.

Methods One hundred and fifty paranasal CT scans (300 sides) were included. Axial images were acquired with multiplanar reformates to obtain delicate details in coronal and sagittal planes.

Results One hundred and forty-four AEAs canal (48%), 293 AEAs foramen (97.7%), and 229 AEAs sulcus could be detected (76.3%). The mean AEA intranasal length was 6.7 ± 1.27 mm (range: 4.24–10.6 mm). The mean angle between AEA and lamina papyracea was 105.49 ± 9.28 degrees (range: 76.41–129.76 degrees). Of them, 95.8% AEAs had an angle with lamina >90 degrees, while 4.2% had angle <90 degrees. The mean angle between AEA and lateral lamella of cribriform plate was 103.95 ± 13.08 degrees (range: 65.57–141.36 degrees). Of them, 87.5% AEAs had an angle >90 degrees and 12.5% had an angle <90 degrees. The mean distance between AEA and skull base was 1.37 ± 1.98 mm (range: 0–8.35 mm). The AEA types in relation to skull base was type 1 (0–2 mm from skull base; 64.6%), type 2 (2–4 mm; 22.2%), type 3 (4–6 mm; 11.1%), and type 4 (>6 mm; 2.1%). The mean distance between the AEA and frontal sinus ostium was 9.17 ± 4.72 mm (range: 0–25.36 mm). AEA classification according to distance from AEA to frontal sinus ostium was 17.4% type 1 (<5 mm), 41.7% type 2 (5–10 mm), 31.9% type 3 (10–15 mm), and 9% type 4 (>15 mm).

Conclusion Provided AEA details improve surgeons' awareness of AEA variations in the endoscopic field and can help residents in training.
Do Maternal Micronutrient Deficiencies Program the Body Composition and Behavior of the Offspring? Probable Underlying Mechanisms
Authors: Kalle Anand Kumar , Ghosh Shampa , Thomas Anju Elizabeth , Manchala Raghunath
Published: January 2020

Obesity and noncommunicable diseases (NCDs) like diabetes are epidemic in India. Developmental origins of health and disease hypothesis, based on epidemiological evidence, associates maternal undernutrition and low birth weight (LBW) of the offspring with increased obesity and diabetes in their later life. Considering widespread maternal micronutrient (MN) deficiencies, LBW, and NCDs in India, we tested the hypothesis, “maternal MN deficiency per se programs the offspring for obesity and increases risk for NCDs in their later life” in rodent models. We showed in Wistar rat offspring that maternal MN (single or combined) deficiency per se: (1) increased body fat (visceral fat) and altered lipid metabolism, (2) decreased lean body and fat free mass, and (3) altered muscle function and altered glucose tolerance/metabolism and insulin sensitivity. Rehabilitation prevented vitamin but not mineral restriction-induced changes in offspring, which showed partial mitigation. Increased oxidative/steroid stress, decreased antioxidant status, and inflammatory state were the associated common mechanisms in the offspring. Our attempts to assess the role of epigenetics showed that folate and/or vitamin B12 deficiencies altered mother’s body composition besides that of the offspring. Additionally, in C57BL/6 mice, B12 deficiency-induced anxiety was observed in mothers and offspring. That expressions of histone modifying enzymes in mice brain and promoter methylation of adiponectin, leptin, and 11βHSD1 genes in rat offspring were altered in MN (B12 and Mg) deficiency suggested that altered epigenetics most likely plays a role in maternal MN deficiency-induced changes in body fat/lipid metabolism and anxiety-like behavior in mothers and offspring.
Is Video Laryngoscopy the Optimal Tool for Successful Intubation in a Neonatal Simulation Setting? A Single-Center Experience
Authors: Musharaf Iram , Daspal Sibasis , Shatzer John
Published: January 2020

Background Endotracheal intubation is a skill required for resuscitation. Due to various reasons, intubation opportunities are decreasing for health care providers.

Objective To compare the success rate of video laryngoscopy (VL) and direct laryngoscopy (DL) for interprofessional neonatal intubation skills in a simulated setting.

Methods This was a prospective nonrandomized simulation crossover trial. Twenty-six participants were divided into three groups based on their frequency of intubation. Group 1 included pediatric residents; group 2 respiratory therapists and transport nurses; and group 3 neonatal nurse practitioners and physicians working in neonatology. We compared intubation success rate, intubation time, and laryngoscope preference.

Results Success rates were 100% for both DL and VL in groups 1 and 2, and 88.9% for DL and 100% for VL in group 3. Median intubation times for DL and VL were 22 seconds (interquartile range [IQR] 14.3–22.8 seconds) and 12.5 seconds (IQR 10.3–38.8 seconds) in group 1 (p = 0.779); 17 seconds (IQR 8–21 seconds) and 12 seconds (IQR 9–16.5 seconds) in group 2 (p = 0.476); and 11 seconds (IQR 7.5–15.5 seconds) and 15 seconds (IQR 11.5–36 seconds) in group 3 (p = 0.024).

Conclusion We conclude that novice providers tend to perform better with VL, while more experienced providers perform better with DL. In this era of decreased clinical training opportunities, VL may serve as a useful tool to teach residents and other novice health care providers.
Gorlin–Goltz Syndrome with Multidisciplinary Approach of Treatment
Authors: Sadaksharam Jayachandran , Annapoorni Amutha Velappan
Published: January 2020

Gorlin–Goltz syndrome, is an uncommon genetic condition characterized by the presence of multiple odontogenic keratocysts of jaws along with several other abnormal, cutaneous, ophthalmic, and osseous displays. This syndrome is also acknowledged by various names, such as nevoid basal cell carcinoma syndrome, jaw cyst, and bifid rib syndrome. This article illustrates about the clinical, radiological, and histological diagnostic findings and the multidisciplinary approach of treatment given to one such rare case of Gorlin–Goltz syndrome.
Superior Semicircular Canal Dehiscence Syndrome
Authors: Steenerson Kristen K. , Crane Benjamin T. , Minor Lloyd B.
Published: January 2020

Superior canal dehiscence syndrome (SCDS) is a vestibular disorder caused by a pathologic third window into the labyrinth that can present with autophony, sound- or pressure-induced vertigo, and chronic disequilibrium among other vestibulocochlear symptoms. Careful history taking and examination in conjunction with appropriate diagnostic testing can accurately diagnose the syndrome. Key examination techniques include fixation-suppressed ocular motor examination investigating for sound- or pressure-induced eye movements in the plane of the semicircular canal. Audiometry, vestibular evoked myogenic potentials, and computed tomography confirm the diagnosis. Corrective surgical techniques can be curative, but many patients find their symptoms are not severe enough to undergo surgery. Although a primarily peripheral vestibular disorder, as first-line consultants for most dizziness complaints, neurologists will serve their patients well by understanding SCDS and its role in the differential diagnosis of vestibular disorders.
Does Universal Coverage Mitigate Racial Disparities in Potentially Avoidable Maternal Complications?
Authors: Ranjit Anju , Andriotti Tomas , Madsen Cathaleen , Koehlmoos Tracey , Staat Barton , Witkop Catherine , Little Sarah E. , Robinson Julian
Published: January 2020

Objective Potentially avoidable maternity complications (PAMCs) have been validated as an indicator of access to quality prenatal care. African-American mothers have exhibited a higher incidence of PAMCs, which has been attributed to unequal health coverage. The objective of this study was to assess if racial disparities in the incidence of PAMCs exist in a universally insured population.

Study Design PAMCs in each racial group were compared relative to White mothers using multivariate logistic regression. Stratified subanalyses assessed for adjusted differences in the odds of PAMCs for each racial group within direct versus purchased care.

Results A total of 675,553 deliveries were included. Among them, 428,320 (63%) mothers were White, 112,170 (17%) African-American, 37,151 (6%) Asian/Pacific Islanders, and 97,912 (15%) others. African-American women (adjusted odds ratio [aOR]: 1.05, 95% CI: 1.02–1.08) were more likely to have PAMCs compared with White women, and Asian women (aOR: 0.92, 95% CI: 0.89–0.95) were significantly less likely to have PAMCs compared with White women. On stratified analysis according to the system of care, equal odds of PAMCs among African-American women compared with White women were realized within direct care (aOR: 1.03, 95% CI: 1.00–1.07), whereas slightly higher odds among African-American persisted in purchased (aOR: 1.05, 95% CI: 1.01–1.10).

Conclusion Higher occurrence of PAMCs among minority women sponsored by a universal health coverage was mitigated compared with White women. Protocol-based care as in the direct care system may help overcome health disparities.
Eigenvalues of large chiral non-Hermitian random matrices
Authors: Chang Shuhua , Jiang Tiefeng , Qi Yongcheng
Published: January 2020

We study a non-Hermitian chiral random matrix of which the eigenvalues are complex random variables. The empirical distributions and the radius of the eigenvalues are investigated. The limit of the empirical distributions is a new probability distribution defined on the complex plane. The graphs of the density functions are plotted; the surfaces formed by the density functions are understood through their convexity and their Gaussian curvatures. The limit of the radius is a Gumbel distribution. The main observation is that the joint density function of the eigenvalues of the chiral ensemble, after a transformation, becomes a rotation-invariant determinantal point process on the complex plane. Then, the eigenvalues are studied by the tools developed by Jiang and Qi [J. Theor. Probab. 30, 326 (2017); 32, 353 (2019)]. Most efforts are devoted to deriving the central limit theorems for distributions defined by the Bessel functions via the method of steepest descent and the estimates of the zero of a non-trivial equation as the saddle point.
Microwave reflectometer for density profile and turbulence measurements on the COMPASS tokamak
Authors: Bogar O. , Zajac J. , Zacek F. , Varavin M. , Hron M. , Panek R. , Silva A.
Published: January 2020

The fast microwave reflectometer system on the COMPASS tokamak consists of an O-mode polarized K-band (18 GHz–26 GHz), Ka-band (26 GHz–40 GHz), and a part of U-band (40 GHz–54 GHz). The plasma density profile from the edge plasma area is measured using a fast sweeping rate up of to 6 µs of the probing wave. The processing of the reflected signal is realized by the heterodyne detection configuration based on the I/Q modulator. Two different methods of dynamic calibration of the required linear sweep frequency, together with static frequency and dispersion calibration, were used. The electron density profile was reconstructed by a spectrogram-based method with four sweeps on average. The system has the capability to measure the mid-plane low-field side electron density profile in the density range from 4 × 1018 m−3 to 3.6 × 1019 m−3. Experimental results obtained on COMPASS discharges are presented to demonstrate the performance of the diagnostics.
Trace level toxic ammonia gas sensing of single-walled carbon nanotubes wrapped polyaniline nanofibers
Authors: Ansari Nagma , Lone Mohd Yaseen , Shumaila  , Ali Javid , Zulfequar Mohammad , Husain Mushahid , Islam S. S , Husain Samina
Published: January 2020

This paper presents a two-step enhancement and a comprehensive analysis of single-walled carbon nanotubes (SWCNTs) wrapped polyaniline nanofiber (NPANI) ammonia (NH3) gas sensor at room temperature. SWCNT-PANI composites are successfully synthesized using an efficient and cost-effective rapid in situ chemical polymerization method. The structural morphology and modification of the samples are characterized using field-emission scanning electron microscopy and HRTEM. FTIR and Raman spectroscopic studies are also performed to gain a better insight into the chemical environmental interaction in the as-prepared nanocomposite. The analysis confirms the successful formation of the nanocomposite. The observed NH3 gas-sensing response at 10 ppm of SWCNT, f-SWCNT (functionalised SWCNT), and SWCNT-PANI composite sensors are 5%–6%, 18%–20%, and 24%–25%, respectively. The SWCNT-PANI composite sensors have shown higher repeatability, selectivity, long-term stability, and fast response-recovery characteristics as compared to f-SWCNTs and pristine SWCNT sensors. Concentration and temperature dependent gas-sensing studies are also analyzed. The sensor response also shows a linear relationship with NH3 gas concentration and an inverse relationship with increasing temperature.
Applications of extracellular vesicles in tissue regeneration
Authors: Ma Zhijie , Wang Yang , Li Haiyan
Published: January 2020

Extracellular vesicles (EVs) can be classified into several types based on their different biosyntheses or release pathways, including exosomes, microvesicles, apoptotic bodies, and large oncosomes. As they contain DNAs, RNAs, proteins, and other bioactive signals, EVs have been utilized in the diagnosis field for a long time. Considering the fact that stem cells have been widely used for tissue regeneration and EVs possess similar biological properties to their source cells, tissue regeneration abilities of EVs have recently attracted much attention in the regenerative medicine field. In this paper, recent advances and challenges of EVs applied in the repair and regeneration of damaged tissues, such as skin, heart, liver, kidney, bone, and central nervous system, have been summarized. Specifically, critical bioactive molecules, which are encapsulated within EVs and play significant roles in the tissue regeneration, have been highlighted. Finally, the prospects and future development directions of the application of EVs in the field of tissue regeneration have been discussed.
Measurement of a time dependent spatial beam profile of an RF-driven H− ion source
Authors: Wada M. , Shinto K. , Shibata T. , Sasao M.
Published: January 2020

The AC component of a beam current extracted from a negative hydrogen (H−) ion source was detected through a 0.1 mm wide, 66.5 mm long entrance slit to observe the spatial distribution. An internal antenna type multicusp source driven by a 2 MHz radio frequency (RF) power delivered beams to an electrostatic accelerator coupled to a pair of magnetic lenses. The local beam intensity measured by a Faraday cup after the entrance slit exhibited an oscillation showing two main frequency components: the RF power supply frequency and the frequency two times the driving RF. The frequency spectrum of the detected signal showed sharp peaks at 2 MHz, 4 MHz, and 6 MHz as well as at 3 MHz and 5 MHz. A 1 mm displacement of the Faraday cup slit position from the center of the beam axis increased the oscillation amplitude, corresponding to a larger amplitude of the AC component at the beam edge.
A powerful pulsed “point-like” neutron source based on the high-current ECR ion source
Authors: Skalyga V. A. , Golubev S. V. , Izotov I. V. , Shaposhnikov R. A. , Razin S. V. , Sidorov A. V. , Bokhanov A. F. , Kazakov M. Yu. , Lapin R. L. , Vybin S. S.
Published: January 2020

The paper presents recent results of a “pointlike” neutron source development based on a D-D fusion in a D-loaded target caused by its bombardment with a sharply focused deuterium ion beam. These developments are undergoing at the Institute of Applied Physics of Russian Academy of Sciences in order to study a possibility to create an effective and compact device for fast-neutron radiography. The last experiments with a beam produced by a gasdynamic high-current ECR ion source and its focusing with a magnetic lens demonstrated that 60 mA of deuterium ions may be constricted to a transversal size of ∼1 mm at the focal plane. With a purpose to improve this result in terms of the beam current and its size, a combined electrostatic and magnetic focusing system is proposed and analyzed. It is shown that the combined system may enhance the total beam current and reduce its footprint down to 0.13 mm. All numerical analysis was performed using the IBSimu code.
Light-induced phenomena in one-component gas: Pressure anisotropy and change of gas temperature
Authors: Chermyaninov I. V. , Chernyak V. G.
Published: January 2020

The phenomena of pressure anisotropy and radiative temperature change in a one-component gas in a field of resonant laser radiation are investigated. This is a continuation of the work by Chermyaninov and Chernyak [“Light-induced phenomena in one-component gas: The transport phenomena,” Phys. Fluids 28, 092007 (2016)]. A model of a limitless gas, and a gas between infinite parallel plates at large Knudsen (Kn ≫ 1) numbers are considered. The mechanisms of these phenomena are discussed. Expressions for the components of the pressure tensor and the change of gas temperature are obtained. Numerical estimates of these effects are provided for the case of the inhomogeneous broadening of the absorption line.
Improving the performance of light-emitting diodes via plasmonic-based strategies
Authors: Fan Xingce , Hao Qi , Qiu Teng , Chu Paul K.
Published: January 2020

Light-emitting diodes (LEDs), featuring long lifetime, small size, and low energy consumption, are increasingly popular for displays and general light sources. In the past decades, new light-emitting materials and novel device configurations are being continuously investigated to obtain highly efficient LEDs. Nevertheless, the unsatisfying external quantum efficiency severely limits their commercial implementation. Among all the approaches to boost the efficiency of LEDs, the incorporation of plasmonic structures exhibits great potential in increasing the spontaneous emission rates of emitters and improving the light extraction efficiency. In this Perspective, the methods to deal with challenges in quantum-well-based LEDs and organic LEDs by employing plasmonic materials are described, the mechanisms of plasmonic-based strategies to improve the light generation and extraction efficiency are discussed, and the plasmonic control over directional emission of phosphors is introduced as well. Moreover, important issues pertaining to the design, fabrication, and manipulation of plasmonic structures in LEDs to optimize the device performance, as well as the selection roles in finding appropriate plasmonic materials and structures for desired LED devices, are explained. This perspective lists the challenges and opportunities of plasmonic LEDs, with the aim of providing some insights into the future trends of plasmonic LEDs.
Numerical investigation of continuous droplet transport in parallel-plate electrowetting-on-dielectric digital microfluidics (EWOD DMF) with stripped electrodes
Authors: Guan Yin , Zhu Mengnan , Li Baiyun , Tu Jiyue , Xing Lu , Chen Xiyang
Published: January 2020

Electrowetting-on-dielectric digital microfluidics (EWOD DMF) has recently emerged as a promising technology for a variety of applications based on the manipulation of discrete microdroplets. A great deal of effort has been devoted to advancing this technology by means of enhancing droplet speed and stability. In this work, we numerically investigate the continuous droplet transport process in a parallel-plate EWOD DMF device with a previously proposed “stripped electrode” design and compare it with the transport motion of the conventional “square electrode” design. The microfluidic droplet motion is solved by a finite volume formulation on a fixed computational domain. The gas-liquid interface of a droplet is captured by a coupled level-set and volume-of-fluid scheme with the surface tension force at the interface computed by the continuum surface force method. A simplified viscous stress scheme reliant on the Hele-Shaw flow model is used to evaluate the viscous forces exerted by the parallel plates. The numerically simulated transport processes of the “stripped electrode” and “square electrode” designs show good agreement with the experimental results. Furthermore, a parametric study is conducted in which the influences of the strip number, activated contact angle, and gap spacing between the plates on droplet transport speed and stability are examined. It has been found that both the transport speed and stability can be noticeably improved by the “stripped electrode” design, which can be adopted for promoting the transport efficiency in a large number of droplet-based applications utilizing parallel-plate EWOD DMF systems.
The effect of kinetics on intrinsic stress generation and evolution in sputter-deposited films at conditions of high atomic mobility
Authors: Jamnig A. , Pliatsikas N. , Sarakinos K. , Abadias G.
Published: January 2020

Vapor-based metal film growth at conditions that promote high atomic mobility is typically accompanied by compressive stress formation after completion of island coalescence, while an apparent stress relaxation is observed upon deposition interruption. Despite numerous experimental studies confirming these trends, the way by which growth kinetics affect postcoalescence stress magnitude and evolution is not well understood, in particular, for sputter-deposited films. In this work, we study in situ and in real-time stress evolution during sputter-deposition of Ag and Cu films on amorphous carbon. In order to probe different conditions with respect to growth kinetics, we vary the deposition rate F from 0.015 to 1.27nm/s, and the substrate temperature TS from 298 to 413K. We find a general trend toward smaller compressive stress magnitudes with increasing TS for both film/substrate systems. The stress-dependence on F is more complex: (i) for Ag, smaller compressive stress is observed when increasing F; (ii) while for Cu, a nonmonotonic evolution with F is seen, with a compressive stress maximum for F=0.102nm/s. Studies of postdeposition stress evolution show the occurrence of a tensile rise that becomes less pronounced with increasing TS and decreasing F, whereas a faster tensile rise is seen by increasing F and TS. We critically discuss these results in view of ex situ obtained film morphology which show that deposition-parameter-induced changes in film grain size and surface roughness are intimately linked with the stress evolution.
Experimental investigation of the Cs behavior in the cesiated H− ion source during high power long beam operation
Authors: Saquilayan Glynnis Mae Q. , Hiratsuka Junichi , Ichikawa Masahiro , Umeda Naotaka , Kojima Atsushi , Watanabe Kazuhiro , Tobari Hiroyuki , Kashiwagi Mieko
Published: January 2020

The behavior of the Cesium (Cs) in Cs-seeded negative ion sources has been investigated experimentally under the beam accelerations of up to 0.5 MeV. The pulse length was extended to 100 s to catch the precise variations in the Cs D2 emission, discharge power, negative ion current, and temperatures in the ion source. The variations of the negative ions were estimated by the beam current and the heat loads in the accelerator. This experiment shows that the buildup of temperature in the chamber walls lead to the evaporation of deposited Cs to enter the plasma region and influenced H− ion production. The H− ion beams were stably sustained by reducing the temperature rise of the chamber wall below 50 °C. A stable long pulse beam could be achieved through the temperature control of the surfaces inside the source chamber walls.
High-temperature properties of Fe-Pt film-magnets prepared by electroplating method
Authors: Yanai Takeshi , Omagari Yuya , Furutani Seiya , Yamashita Akihiro , Fujita Naoyuki , Morimura Takao , Nakano Masaki , Fukunaga Hirotoshi
Published: January 2020

We prepared L10 ordered Fe50Pt50 thick-films on Cu substrates using the electroplating method and evaluated their high-temperature properties in the temperature range of 25-200°C. The Hc and the (BH)max at 150°C for the Fe50Pt50 films annealed by ordinary annealing method (700°C, 60 min) were 500 kA/m and 50 kJ/m3, respectively, and the thermal coefficient of Hc was -0.3%/°C. To improve the high-temperature properties, we employed a flash annealing method using an infrared furnace (8 kW). The flash annealing method improved the high-temperature properties (Hc = 700 kA/m, (BH)max = 70 kJ/m3 at 150°C) and the thermal coefficient (-0.21%/°C). The thermal stability of the films is comparable to those for Sm-Co-system magnets and better than for Nd-Fe-B-system ones. We, therefore, found the L10 ordered Fe50Pt50 films prepared by the electroplating and the flash annealing are one of the hopeful small magnets in the wide temperature range.
The role of effective angle of attack in hovering pitching-flapping-perturbed revolving wings at low Reynolds number
Authors: Chen Long , Zhou Chao , Wu Jianghao
Published: January 2020

Since the performance of revolving wings is limited at a low Reynolds number (Re), the pitching-flapping-perturbed revolving wing (PFP-RW) is proposed as an approach for an augmentation of lift and efficiency. However, the underlying physics of the effective angle of attack (αe) in aerodynamic force generation is underexplored. Here, as a follow-up of our previous study [L. Chen et al., “Unsteady aerodynamics of a pitching-flapping-perturbed revolving wing at low Reynolds number,” Phys. Fluids 30, 051903 (2018)], we further investigate the role of αe in aerodynamic force generation and the corresponding leading-edge vortex (LEV) behaviors of a hovering PFP-RW at Re = 1500. Results show that the efficiency of a PFP-RW with sinusoidal flapping motion can be improved by a sinusoidal modulation of the αe profile while retaining the αe amplitude. Instead of the αe amplitude, if the flapping amplitude is fixed during the sinusoidal modulation of the αe profile, the lift of a PFP-RW is significantly enhanced despite a slight reduction in efficiency. For PFP-RWs with different pitching-flapping perturbations but an identical αe profile, a general trend of resultant-velocity-normalized lift and drag coefficients in the wind frame is predominantly retained, except for the deviations during the late downstroke. The breakdown of the general trend is attributed to the wing-LEV interaction, the effect of which is not reflected by the instantaneous resultant velocity. For PFP-RWs with small-amplitude sinusoidal αe profiles, the variation of pitching-flapping perturbations can further lead to novel LEV behaviors, e.g., a dual-LEV structure, during its formation. Our findings can provide guidance for the control of pitching-flapping perturbations on PFP-RWs.
Microwave detector diodes based on InGaAs/AlGaAs/GaAs heterostructures
Authors: Vostokov N. V. , Revin M. V. , Shashkin V. I.
Published: January 2020

An original low-barrier diode n+-InGaAs/AlGaAs/n+-GaAs heterostructure was developed and grown by metalorganic vapor phase epitaxy. Growth conditions are practically the same as were used in standard pseudomorphic high-electron-mobility transistor technology. Test diodes were made on the basis of the heterostructure and their transport properties were studied. For comparison with experimental results, the transport characteristics of diodes were simulated in the framework of the combined thermionic-emission/diffusion theory. A useful method for the microwave measurements of diodes on a wafer was employed, which allows one to determine all the main parameters of the equivalent diode circuit and their detection characteristics. The diodes have a high quadratic nonlinearity parameter value (> 20 V−1) and small specific values of differential resistance (10−4 Ω cm2) and capacitance (10−7 F/cm2) at zero bias. The prospects of using the developed heterostructure to create highly sensitive microwave radiation detectors are shown.
A 30-nm thick integrated hafnium zirconium oxide nano-electro-mechanical membrane resonator
Authors: Ghatge M. , Walters G. , Nishida T. , Tabrizian R.
Published: January 2020

This paper reports a 30 nm-thick integrated nano-electro-mechanical resonator based on atomically engineered ferroelectric hafnium zirconium oxide (Hf0.5Zr0.5O2) film. A 10 nm-thick Hf0.5Zr0.5O2 layer is atomically engineered through capping with 10 nm-thick titanium nitride (TiN) layer and rapid thermal annealing to promote the orthorhombic crystal phase with strong ferroelectric properties. The resulting metal-ferroelectric-metal (MFM) membrane is then patterned to create an integrated nano-electro-mechanical resonator with an overall thickness of 30 nm and a planar-to-vertical aspect ratio exceeding 104:1. Benefiting from large electrostrictive effects in ferroelectric Hf0.5Zr0.5O2, the 30 nm-thick nanomechanical resonator is excited into flexural resonance at 195 kHz with a very large vibration amplitude of ∼100 nm. The transmission response of the nano-electro-mechanical resonator is extracted, using a two-port apodization of the TiN electrodes, showing quality factors (Q) of 15 and 3300 at atmospheric and 10−7 Torr ambient pressures, respectively. Finally, the structural robustness of the MFM nano-membrane is explored through the application of a ∼24 μm deflection, using a point-force by a micro-probe, highlighting the extended elasticity despite the small thickness and ultra-high aspect ratio. The atomic-level thickness, fully integrated operation, high Q, and structural robustness of the Hf0.5Zr0.5O2-based nano-membrane resonator promise its potential for the realization of highly integrated transducers for chip-scale classical and quantum information processing and sensing applications.
Toward attosecond control of electron dynamics in two-dimensional materials
Authors: Guan Mengxue , Hu Shiqi , Zhao Hui , Lian Chao , Meng Sheng
Published: January 2020

Attosecond motion of strongly driven electrons encodes information on intense laser–solid interactions, leading to material- and laser-dependent photoemission and high-harmonic generation (HHG). Here, we investigate sub-cycle control over the electron dynamics in two-dimensional (2D) materials via adjusting the relative phase of two-color pulses. Electrons in 2D solids are sensitive to the exact shape of the optical field, showing properties similar to those of isolated atoms. Accompanied by spectra modulations, the resultant harmonic yields are enhanced and the cutoff energy increases to a ratio as large as 24% when an optimized phase is applied. Different from the atomic-like HHG, however, the cutoff energy is linearly dependent on the maximum strength of the light electric field, in line with that shown in conventional bulk solids. Thus, two-dimensional materials provide a unique platform where both bulk and atomic electron dynamics can be investigated. Our work suggests a simple way to generate optimized harmonic emission with existing experimental laser technology and offers a powerful tool for analyzing attosecond quantum dynamics during laser–solid interactions.
Stochastic magnetoelectric neuron for temporal information encoding
Authors: Yang Kezhou , Sengupta Abhronil
Published: January 2020

Emulating various facets of computing principles of the brain can potentially lead to the development of neuro-computers that are able to exhibit brain-like cognitive capabilities. In this Letter, we propose a magnetoelectronic neuron that utilizes noise as a computing resource and is able to encode information over time through the independent control of external voltage signals. We extensively characterize the device operation using simulations and demonstrate its suitability for neuromorphic computing platforms performing temporal information encoding.