bluuebunny/crossref_metadata_2025 huggingface dataset:
Macrophage polarization plays roles in bone formation instructed by calcium phosphate ceramics
Authors: Li Mingzheng , Guo Xiaodong , Qi Wenting , Wu Zhenzhen , de Bruijn Joost D. , Xiao Yu , Bao Chongyun , Yuan Huipin
Published: January 2020

TCPs recruited more macrophages which polarized towards tissue repair macrophages to create a favourable osteo-immune environment for material-instructed bone formation.
Refining transfer set in calibration transfer of near infrared spectra by backward refinement of samples
Authors: Zheng Kaiyi , Feng Tao , Zhang Wen , Huang Xiaowei , Li Zhihua , Zhang Di , Shi Jieyong , Marunaka Yoshinori , Zou Xiaobo
Published: January 2020

We report a backward refinement method applied to multiple near infrared datasets to obtain small prediction errors.
Enhanced performance of a core–shell structured Fe(0)@Fe oxide and Mn(0)@Mn oxide (ZVIM) nanocomposite towards remediation of arsenic contaminated drinking water
Authors: Panda Amulya Prasad , Rout Priyanka , Kumar Sanjukta A. , Jha Usha , Swain S. K.
Published: January 2020

A unique core–shell structured Fe(0)@Fe oxides and Mn(0)@Mn oxides (ZVIM) nanocomposite was synthesized and utilized for effective remediation of arsenic contaminated drinking water.
Molecular and environmental factors regulating seed longevity
Authors: Zinsmeister Julia , Leprince Olivier , Buitink Julia
Published: January 2020

Seed longevity is a central pivot of the preservation of biodiversity, being of main importance to face the challenges linked to global climate change and population growth. This complex, quantitative seed quality trait is acquired on the mother plant during the second part of seed development. Understanding what factors contribute to lifespan is one of the oldest and most challenging questions in plant biology. One of these challenges is to recognize that longevity depends on the storage conditions that are experimentally used because they determine the type and rate of deleterious conditions that lead to cell death and loss of viability. In this review, we will briefly review the different storage methods that accelerate the deteriorative reactions during storage and argue that a minimum amount of information is necessary to interpret the longevity data. Next, we will give an update on recent discoveries on the hormonal factors regulating longevity, both from the ABA signaling pathway but also other hormonal pathways. In addition, we will review the effect of both maternal and abiotic factors that influence longevity. In the last section of this review, we discuss the problems in unraveling cause-effect relationship between the time of death during storage and deteriorative reactions leading to seed ageing. We focus on the three major types of cellular damage, namely membrane permeability, lipid peroxidation and RNA integrity for which germination data on seed stored in dedicated seed banks for long period times are now available.
CP-25 inhibits PGE2-induced angiogenesis by down-regulating EP4/AC/cAMP/PKA-mediated GRK2 translocation
Authors: Han Chen-Chen , Liu Qian , Zhang Yu , Li Yi-Fan , Cui Dong-Qian , Luo Ting-Ting , Zhang Yu-Wen , Wang Xin-Ming , Wang Chun , Ma Yang , Wei Wei
Published: January 2020

G protein-coupled receptor kinase 2 (GRK2), a type of cytosolic enzyme, transiently translocates to the plasma membrane upon G protein-coupled receptors (GPCRs) activation, and it also binds to extracellular signal-regulated kinase (ERK) to inhibit the activation of ERK. GRK2 deficiency in endothelial cells (ECs) leads to increased pro-inflammatory signaling and promotes recruitment of leukocytes to activated ECs. However, the role of GRK2 in regulating angiogenesis remains unclear. Here, we show that GRK2 is a novel regulatory molecule on migration and tube formation of ECs, vessel sprouting ex vivo and angiogenesis in vivo. We identify that EP4/AC/cAMP/protein kinase A (PKA)-mediated GRK2 translocation to cells membrane decreases the binding of GRK2 and ERK1/2 to inhibit ERK1/2 activation, which promotes prostaglandin E2 (PGE2)-induced angiogenesis. GRK2 small interfering RNA (siRNA) inhibits the increase in PGE2-induced HUVECs migration and tube formation. In vivo, PGE2 increases ECs sprouting from normal murine aortic segments and angiogenesis in mice, but not from GRK2-deficient ones, on Matrigel. Further research found that Lys220 and Ser685 of GRK2 play an important role in angiogenesis by regulating GRK2 translocation. Paeoniflorin-6′-O-benzene sulfonate (CP-25), as a novel ester derivative of paeoniflorin (pae), has therapeutic potential for the treatment of adjuvant arthritis (AA) and collagen-induced arthritis (CIA), but the underlying mechanism of CP-25 on angiogenesis has not been elucidated. In our study, CP-25 inhibits the migration and tube formation of HUVECs, and angiogenesis in mice by down-regulating GRK2 translocation activation without affecting GRK2 total expression. Taken together, the present results revealed that CP-25 down-regulates EP4/AC/cAMP/PKA-mediated GRK2 translocation, restoring the inhibition of GRK2 for ERK1/2, thereby inhibiting PGE2-stimulated angiogenesis.
Remote Microphone System Use in the Homes of Children With Hearing Loss: Impact on Caregiver Communication and Child Vocalizations
Authors: Thompson Emily C. , Benítez-Barrera Carlos R. , Angley Gina P. , Woynaroski Tiffany , Tharpe Anne Marie
Published: January 2020

Purpose

This study examined the impact of home use of remote microphone systems (RMSs) on caregiver communication and child vocalizations in families of children with hearing loss.

Method

We drew on data from a prior study in which Language ENvironmental Analysis recorders were used with 9 families during 2 consecutive weekends—1 that involved using an RMS and 1 that did not. Audio samples from Language ENvironmental Analysis recorders were (a) manually coded to quantify the frequency of verbal repetitions and alert phrases caregivers utilized in communicating to children with hearing loss and (b) automatically analyzed to quantify children's vocalization rate, duration, complexity, and reciprocity when using and not using an RMS.

Results

When using an RMS at home, caregivers did not repeat or clarify their statements as often as when not using an RMS while communicating with their children with hearing loss. However, no between-condition differences were observed in children's vocal characteristics.

Conclusions

Results provide further support for home RMS use for children with hearing loss. Specifically, findings lend empirical support to prior parental reports suggesting that RMS use eases caregiver communication in the home setting. Studies exploring RMS use over a longer duration of time might provide further insight into potential long-term effects on children's vocal production.
Feedback controlled pseudo resistor
Authors: Zhou Zhijun , Warr Paul
Published: January 2020

The pseudo resistor (PR) is widely used in integrated circuits. It comprises two transistors back‐to‐back to force them into the sub‐threshold region, which provides large resistance with a small die area. However, its linearity is limited by the non‐linear MOS transistors in weak inversion. In this Letter, a new PR topology is proposed, employing a feedback loop that continuously adjusts the voltage at the shared gate node of the PR with the input signal. The proposed architecture substantially increases the linearity and impedance of the PR.
Semi‐supervised uncorrelated dictionary learning for colour face recognition
Authors: Liu Qian , Jiang Bo , Zhang Jia‐lei , Gao Peng , Xia Zhi‐jian
Published: January 2020

Colour images are increasingly used in the fields of computer vision, pattern recognition and machine learning, since they can provide more identifiable information than greyscale images. Thus, colour face recognition has attracted accumulating attention. Its key problem is how to remove the similarity between colour component images and take full advantage of colour difference information. Decision‐level similarity reduction between colour component images directly affects the recognition effect, but it has been found in no work. In this study, the authors propose a novel colour face recognition approach named semi‐supervised uncorrelated dictionary learning (SUDL), which realises decision‐level similarity reduction and fusion of all colour components in face images. SUDL employs the labelled and unlabelled colour face image samples into structured dictionary learning to achieve three uncorrelated discriminating dictionaries corresponding to three colour components of face images, and then uses these dictionaries and the sparse coding technique to make a classification decision. Experimental results in multiple public colour face image databases demonstrate that the dictionary decorrelation, structured dictionary learning and unlabelled samples used in the proposed approach are effective and reasonable, and the proposed approach outperforms several representative colour face recognition methods in recognition rates, despite of its poor time performance.
A systematic review of the role of non-magnified endoscopy for the assessment of H. pylori infection
Authors: Glover Ben , Teare Julian , Patel Nisha
Published: January 2020

Background and study aims There is growing interest in the endoscopic recognition of Helicobacter pylori infection, and application to routine practice. We present a systematic review of the current literature regarding diagnosis of H. pylori during standard (non-magnified) endoscopy, including adjuncts such as image enhancement and computer-aided diagnosis.

Method The Medline and Cochrane databases were searched for studies investigating performance of non-magnified optical diagnosis for H. pylori, or those which characterized mucosal features associated with H. pylori infection. Studies were preferred with a validated reference test as the comparator, although they were included if at least one validated reference test was used.

Results Twenty suitable studies were identified and included for analysis. In total, 4,703 patients underwent investigation including white light endoscopy, narrow band imaging, i-scan, blue-laser imaging, and computer-aided diagnostic techniques. The endoscopic features of H. pylori infection observed using each modality are discussed and diagnostic accuracies reported. The regular arrangement of collecting venules (RAC) is an important predictor of the H. pylori-naïve stomach. “Mosaic” and “mottled” patterns have a positive association with H. pylori infection. The “cracked” pattern may be a predictor of an H. pylori-negative stomach following eradication.

Conclusions This review summarizes current progress made in endoscopic diagnosis of H. pylori infection. At present there is no single diagnostic approach that provides validated diagnostic accuracy. Further prospective studies are required, as is development of a validated classification system. Early studies in computer-aided diagnosis suggest potential for a high level of accuracy but real-time results are awaited.
Standard versus simplified radiofrequency ablation protocol for Barrett’s esophagus: comparative analysis of the whole treatment pathway
Authors: Tan Wei Keith , Ragunath Krish , White Jonathan R. , Santiago Jose , Fernandez-Sordo Jacobo Ortiz , Pana Mirela , Alias Bincy , Hadjinicolaou Andreas V. , Sujendran Vijay , di Pietro Massimiliano
Published: January 2020

Background and study aims The standard radiofrequency ablation (RFA) protocol for Barrett’s esophagus (BE) encompasses an intermediary cleaning phase between two ablation sessions. A simplified protocol omitting the cleaning phase is less labor-intensive but equally effective in studies based on single ablation procedures. The aim of this study was to compare efficacy and safety of the standard and simplified RFA protocols for the whole treatment pathway for BE, including both circumferential and focal devices.

Patients and methods We performed a retrospective analysis of prospectively collected data on patients receiving RFA between January 2007 and August 2017 at two institutions. Outcomes assessed were: 1) complete remission of dysplasia (CR-D) and intestinal metaplasia (CR-IM) at 18 months; and 2) rate of esophageal strictures.

Results One hundred forty-five patients were included of whom 73 patients received the standard and 72 patients received the simplified protocol. CR-D was achieved in 94.5 % and 95.8 % of patients receiving the standard and simplified protocol, respectively (P = 0.71). CR-IM was achieved in 84.9 % and 77.8 % of patients treated with the standard and simplified protocol, respectively (P = 0.27). Strictures were significantly more common among patients who received the simplified protocol (12.5 %) compared to the standard protocol (1.4 %; P = 0.008). The median number of esophageal dilations was one.

Conclusion The simplified RFA protocol is as effective as the standard protocol in eradicating BE but carries a higher risk of strictures. This needs to be taken into account, particularly in patients with higher pretreatment risk of strictures, such as those with esophageal narrowing from previous endoscopic mucosal resection (EMR).
Endoscopic ultrasound-guided pancreatic duct intervention and pancreaticogastrostomy using a novel cross-platform technique with small-caliber devices
Authors: Hayat Umar , Freeman Martin L. , Trikudanathan Guru , Azeem Nabeel , Amateau Stuart K. , Mallery James
Published: January 2020

Background and study aims Endoscopic ultrasound (EUS)-guided pancreaticogastrostomy (PG) has been used as an alternative to surgery to drain pancreatic ducts for treatment of disconnected pancreatic duct syndrome (DPDS). Previous techniques involved using needle-knife cautery, bougie dilation or a stent extraction screw to allow stent passage through the gastric wall and pancreatic parenchyma, with potential for severe complications including duct leak, especially if drainage fails. A novel technique employing EUS guided puncture of the main pancreatic duct (MPD) with a 19- or a 22-gauge needle, passage of an 0.018-guidewire, dilation of the tract with a small-diameter (4 F) angioplasty balloon and placement of 3F plastic stents with the pigtail curled inside the duct as an anchor.

Methods This is a retrospective case series at a single tertiary center. EUS-guided PG was considered when conventional endoscopic pancreatic duct drainage failed. Main outcomes included technical and clinic success and complications.

Results Eight patients underwent PG. Indications were DPDS (n = 4), stenotic pancreaticoenteral anastomosis after Whipple procedure (n = 3) and chronic pancreatitis with dilated MPD (n = 1). Median MPD diameter was 6.75 mm [IQR 2.8 – 7.6]. Technical success was achieved in seven of eight cases (88 %); angioplasty balloon passed into the pancreatic duct in all accessed ducts. There was one asymptomatic duct leak, and no major or delayed complications, with clinical improvement (complete or partial) in five of eight (71 %).

Conclusions EUS-guided PG using a small-caliber guidewire, 4F angioplasty balloon, and reverse 3F single pigtail stents offers a safe and atraumatic alternative without use of cautery.
Narkoseführung bei Elektrochemotherapie
Authors: Volberg Christian , Gschnell Martin
Published: January 2020

Die Elektrochemotherapie (ECT) ist ein Verfahren zur Symptomkontrolle bei inoperablen oder exulcerierenden Hautmetastasen oder -karzinomen. Mit Hilfe der Elektroporation wird eine Wirkverstärkung des verabreichten Chemotherapeutikum, Bleomycin oder Cisplatin, erreicht und eine lokale Reduktion der Metastasen, bei gleichzeitig geringer systemischer Belastung, hervorgerufen. Man kann die ECT in Lokal-, Regional- oder Allgemeinanästhesie durchführen, wobei sich die Form der Anästhesie nach der Anzahl und Ausdehnung der Metastasen, sowie der betroffenen Körperstelle richtet. Bei der Allgemeinanästhesie sind einige Besonderheiten zu beachten. Um einer Lungenschädigung durch Bleomycin vorzubeugen, muss der Patient mit einem geringen FiO2 (< 0,3), oder am besten mit Raumluft, beatmet werden. Zur Vermeidung von Medikamenteninteraktionen und postoperativen Schmerzen wird die Allgemeinanästhesie als TIVA in tiefer Relaxierung durchgeführt. Das Anästhesieteam sollte Kenntnis über die notwendigen Vorsichtsmaßnahmen bei Applikation von Chemotherapeutika haben und Kontraindikationen für die Durchführung einer Narkose bei ECT bereits im Vorfeld erkennen.
Anatomical variants of profunda femoris artery : among cadavers from South India
Authors: KV Vinay , AY Raghavendra ,   Vishal K,   Shishir K
Published: January 2020

Background: The profunda femoris artery (PFA) is a branch of femoral artery which plays an important role in the arterial supply of the thigh. An extensive knowledge of the branching pattern and relations are necessary for clinicians to prevent any iatrogenic damage to these blood vessels and the surrounding structures in vascular reconstructive surgeries. Objective: To study the direction of origin of PFA from femoral artery and measure DIP- the distance between the origin of PFA from femoral artery to midpoint of inguinal ligament. Materials and Methods: Forty six femoral triangles (23 on right & 23 on left side) were dissected and studied in embalmed cadavers available in dissection hall of K. S. Hegde Medical Academy, Mangalore, India over a period of two years from July 2011 to July 2013. These cadavers were of South Indian origin. The direction of origin of PFA from femoral artery was noted. The DIP was measured using Vernier caliper. Results: The direction of origin of the PFA in majority of the cases was found to be from the posterolateral side (65.22%) of femoral artery. The DIP varies from 25 to 50 mm on the right and 24 to 60 mm on the left side. In 50 % of the cases, the DIP was in the range of 41 to 50 mm on both the sides. Conclusion: The anatomical data obtained here is of importance for surgeons and radiologists for procedures centred on the PFA and in vascular reconstructive surgeries involving the groin.
Limb body wall complex - report of an unusual case
Authors: Rao Vuba Rama , Revathi P , Priya Vuba Sujana , Karuna V , Gupta Anirban Das , Swetha V , Ramurthy N
Published: January 2020

Limb body wall complex is an extremely rare birth defect and a foetal polymalformative syndrome. A case of Gravida-2, Para-0, Abortion-1 with 20 weeks of pregnancy who attended the antenatal clinic in the month of may 2012, at Konaseema Institiute of Medical Sciences and Research foundation (KIMS&RF), Amalapuram, Andhra Pradesh, underwent routine anomaly scan which showed a polymalformative fetus. The pregnancy was terminated. The physical examination findings of the aborted fetus were suggestive of limb body wall complex (LBWC).
Third head of sternocleidomastoid muscle
Authors: Sabnis Anjali Satyen , Shaikh Shaguphta T , More Rakhi Milind
Published: January 2020

During routine dissection in the neck region, a third head of sternocleidomastoid (SCM) muscle was found unilaterally in one cadaver and bilaterally in another cadaver. In both the cases third head was supplied by the spinal accessory nerve. SCM is most prominent muscle in the neck region which is used as important landmark during teaching living anatomy and gross anatomy of triangles of neck to students. As many important nerves and vessels are related to this key muscle of neck, any variation in relation to its origin, insertion and nerve supply attracts the attention of surgeons and anatomists. Embryological basis and clinical significance was discussed in these two cases of unilateral and bilateral presence of third head of SCM.
Unusually large thymus showing involution - a case report
Authors: Xaviour Rosemol , K. Girijamony V , B. Sheela
Published: January 2020

The most superficial structure in the superior mediastinum, the thymus, usually continues to grow up to the age of 5-6yrs and progressively involutes thereafter. It hardly weighs more than 10 gms in an adult. During routine dissection of a cadaver in the Anatomy Department, Government Medical College, Thrissur,an unusually large thymus was noticed in the superior mediastinum extending into the anterior mediastinum. After histological examination of the same by the Pathologist, it was concluded as a case of thymus showing involution rather than a Thymoma or a Thymic Hyperplasia.
Use of beeswax for repair of damaged dry human bones in anatomy
Authors: Bhat Shruthi , Nayak Sheela G , Pare Vidyashambhava , Borker Sagar
Published: January 2020

Background: Beehives are made up of wax, which are the natural glandular secretions of honeybees. One such huge beehive was incidentally noticed on the wall behind the Department of Anatomy, K.V.G. Medical College Sullia in 2012. The bees had already abandoned it and there were no bees even fluttering around. So we plucking it ensured that it was excised as a whole, instead of allowing it to get biodegraded. With assistance we got it to the Department. Objective: To study the architecture of this beehive and use of its wax to repair damaged dry human bones in the Department of Anatomy. Materials and Methods: Spirit lamp, spirit, Forceps, Cutting blades, quick fix, varnish, spatula and enamel paint were used for the study. Wax melted when heated at 62-65degree Celsius. Crude wax of the beehive was placed on the damaged bone by plucking a part of it. Then the bone was given a correct shape manually. Damaged bone part was repaired artistically using a hot spatula. Results: We could repair many damaged bones with this chunk of wax. Conclusion: This is a simple, cost effective, appropriate technique of bone repair in Anatomy. Regular maintenance of bones will prevent its damage. Thus bones can be used for a long period which can ensure percolation of right information to students of Anatomy.
Perforated transverse vaginal septum - report of an unusual case
Authors: Ramarao Vuba , Revathi P , Gupta Anirban Das , Mohanrao B.Rama , Saha Aditi
Published: January 2020

A case of perforated transverse vaginal septum in the middle third of the vagina, in a 21 yrs old recently married lady who came for evaluation of dyspareunia at OPD of Gynaecology, Konaseema Institute of Medical Sciences & Research Foundation, Amalapuram, Andhra Pradesh is reported here. Diagnosis was made clinically and later on confirmed by USG. The patient was treated surgically by excision of the septum following which she conceived successfully. The patient is presently carrying 10 weeks as on the day of reporting and is under our constant follow up.
Anatomical skin incisions for window dissections
Authors: Dixit Daksha , Singel T.C. , Talsaniya Dhaval , Changani Mohit
Published: January 2020

Skin incisions for comprehensive study dissection, composite dissection, composite window corridor dissection and comprehensive window dissections are different. Many authors/practical volumes have described skin incisions for comprehensive study dissections. There is great need to establish, describe and define the incisions for comprehensive window dissections. The authors have studied and practiced their skin incisions for window dissections of various regions of limbs, during the last three years(2010-2012). The authors have established superior, inferior and vertical incision lines and skin was incised according to that. Skin incisions for various regions are made on the basic principle of windows. Superior and inferior incision lines limit the dissection area and vertical incision line provides better scope of expansion and exposure in a window view. The authors have established, described and defined the incisions for various dissection topics which gives better exposure and scope for expansion of dissection layer wise and in better window manner.
Unusual site of formation of brachiocephalic vein along with multiple venous anomalies in neck and its clinical importance
Authors: Jana Rashmoni
Published: January 2020

Neck veins are important for various diagnostic, therapeutic and experimental procedures. So knowledge of their anatomical variation is also important. The author reports an unusual site of formation of brachiocephalic vein with multiple venous anomalies in the neck. A rare site of formation of the right brachiocephalic vein was found at the middle of neck under the right sternocleido mastoid muscle by union of right internal jugular and subclavian vein. Another observation was of facial, lingual and superior thyroid veins joined together and formed a common vein over the sternocleidomastoid muscle that drained into the external jugular vein. This unusual course of brachiocephalic vein and aberrant drainage of facial, lingual and superior thyroid veins may cause unusual bleeding during surgeries and invasive procedures. So clinicians should be aware of these variations of major neck veins to avoid complications.
An ensemble of random graphs with identical degree distribution
Authors: Ma Fei , Wang Xiaomin , Wang Ping
Published: January 2020

Degree distribution, or equivalently called degree sequence, has been commonly used to study a large number of complex networks in the past few years. This reveals some intriguing results, for instance, the popularity of power-law distribution in most of these networks under consideration. Along such a research line, in this paper, we generate an ensemble of random graphs with an identical degree distribution P(k)∼k−γ (γ=3) as proved shortly, denoted as graph space N(p,q,t), where probability parameters p and q hold on p+q=1. Next, we study some topological structure properties of great interest on each member in the graph space N(p,q,t) using both precisely analytical calculations and extensively numerical simulations, as follows. From the theoretical point of view, given an ultrasmall constant pc, perhaps only the graph model N(1,0,t) is small-world and the others are not in terms of diameter. Then, we obtain exact solutions for a spanning tree number on two deterministic graph models in the graph space N(p,q,t), which gives both upper bound and lower bound for that of other members. Meanwhile, for an arbitrary p(≠1), we prove using the Pearson correlation coefficient that the graph model N(p,q,t) does go through two phase transitions over time, i.e., starting by a nonassortative pattern, then suddenly going into a disassortative region, and gradually converging to an initial position (nonassortative point). Therefore, to some extent, the three topological parameters above can serve as the complementary measures for degree distribution to help us clearly distinguish all members in the graph space N(p,q,t). In addition, one “null” graph model is built.
Reciprocal characterization from multivariate time series to multilayer complex networks
Authors: Zhao Yi , Peng Xiaoyi , Small Michael
Published: January 2020

Various transformations from time series to complex networks have recently gained significant attention. These transformations provide an alternative perspective to better investigate complex systems. We present a transformation from multivariate time series to multilayer networks for their reciprocal characterization. This transformation ensures that the underlying geometrical features of time series are preserved in their network counterparts. We identify underlying dynamical transitions of the time series through statistics of the structure of the corresponding networks. Meanwhile, this allows us to propose the concept of interlayer entropy to measure the coupling strength between the layers of a network. Specifically, we prove that under mild conditions, for the given transformation method, the application of interlayer entropy in networks is equivalent to transfer entropy in time series. Interlayer entropy is utilized to describe the information flow in a multilayer network.
Shallow impurity band in ZrNiSn
Authors: Schrade Matthias , Berland Kristian , Kosinskiy Andrey , Heremans Joseph P. , Finstad Terje G.
Published: January 2020

ZrNiSn and related half Heusler compounds are candidate materials for efficient thermoelectric energy conversion with a reported thermoelectric figure-of-merit of n-type ZrNiSn exceeding unity. Progress on p-type materials has been more limited, which has been attributed to the presence of an impurity band, possibly related to Ni interstitials in a nominally vacant 4d position. The specific energetic position of this band, however, has not been resolved. Here, we report the results of a concerted theory-experiment investigation for a nominally undoped ZrNiSn, based on the electrical resistivity, the Hall coefficient, the Seebeck coefficient, and the Nernst coefficient, measured in a temperature range from 80 to 420 K. The results are analyzed with a semianalytical model combining a density functional theory (DFT) description for ideal ZrNiSn, with a simple analytical correction for the impurity band. The model provides a good quantitative agreement with experiment, describing all salient features in the full temperature span for the Hall, conductivity, and Seebeck measurements, while also reproducing key trends in the Nernst results. This comparison pinpoints the impurity band edge to 40 meV below the conduction band edge, which agrees well with a separate DFT study of a supercell containing Ni interstitials. Moreover, we corroborate our result with a separate study of the ZrNiSn0.9Pb0.1 sample showing similar agreement with an impurity band edge shifted to 32 meV below the conduction band.
A novel Lyapunov theorem on finite/fixed-time stability of discontinuous impulsive systems
Authors: Wang Zengyun , Cao Jinde , Cai Zuowei , Abdel-Aty Mahmoud
Published: January 2020

This paper deals with the Finite/Fixed-Time Stability (FTS) problem of the discontinuous impulsive differential equation. Under the framework on differential inclusion, this problem can be transformed into the FTS problem of impulsive differential inclusion. A uniform criterion on FTS of nonlinear discontinuous impulsive differential systems with pre-given finite impulse instances is established, which is effective for both stabilizing impulses and destabilizing impulses. During this process, we propose an improved Lyapunov method, where the derivative of the Lyapunov Function (LF) may not exist in some instances. Moreover, the upper-bound estimation for the derivative of LF is allowed to be a time-varying function and takes both positive and negative values. Finally, the proposed criterion is supported by two numerical examples.
Linear thermomagnetic energy harvester for low-grade thermal energy harvesting
Authors: Kishore Ravi Anant , Singh Deepa , Sriramdas Rammohan , Garcia Anthony Jon , Sanghadasa Mohan , Priya Shashank
Published: January 2020

Low-grade thermal energy, either from waste heat or from natural resources, constitutes an enormous energy reserve that remains to be fully harvested. Harvesting low-grade heat is challenging because of the low Carnot efficiency. Among various thermal energy harvesting mechanisms available for capturing low-grade heat (temperature less than 100 °C), the thermomagnetic effect has been found to be quite promising. In this study, we demonstrate a scalable thermomagnetic energy harvester architecture that exhibits 140% higher power density compared to the previously published spring–mass designs. The alternating force required to oscillate the thermomagnetic mass is generated through the interaction between two magnetic forces in opposite directions. We employed numerical modeling to illustrate the behavior of a thermomagnetic device under different operating conditions and to obtain the optimal hot-side and cold-side temperatures for continuous mode operations. A miniaturized thermomagnetic harvester was fabricated and experiments were conducted to systematically evaluate the performance. The prototype was found to exhibit an oscillation frequency of 0.33 Hz, a work output of 0.6 J/kg/cycle, and a power density of 0.2 W/kg of gadolinium under the temperature difference of 60 K.
Reversible H-T′ phase transition in monolayer molybdenum disulfide via electron beam assisted solid state lithiation/delithiation
Authors: Ji Xujing , Wu Chunyang , Deng Jingfei , Li Jixue , Jin Chuanhong
Published: January 2020

Two-dimensional (2D) transition metal dichalcogenides (TMDs) possess a variety of polymorphs that exhibit distinctive atomic and electronic structures and the consequent material properties. Hence, exploiting the dynamics of phase transition between different polymorphs will lay a foundation toward controlled phase engineering based applications. In this Letter, we reported a solid-state approach to realize the H to T′ transition in monolayer molybdenum disulfide in situ inside a transmission electron microscope. The release of lithium ions and the subsequent lithiation were driven by energetic electron beam irradiation, both of which in turn triggered the H to T′ phase transition of the object monolayer MoS2. The as-formed T′ phase domains showed a random nucleation behavior. Interestingly, the reverse process, i.e., T′ back to H phase transition, caused by prolonged e-beam illumination, was also captured in situ. During both phase transformation processes, i.e., H → T′ and T′ → H, we did not observe any large area T phase existing in monolayer MoS2. Our results will be instructive to elucidate the microscopic mechanisms of the phase transition and should also be extendable to other 2D TMD materials.
Control of passivation and compensation in Mg-doped GaN by defect quasi Fermi level control
Authors: Klump A. , Hoffmann M. P. , Kaess F. , Tweedie J. , Reddy P. , Kirste R. , Sitar Z. , Collazo R.
Published: January 2020

A defect quasi Fermi level (dQFL) control process based on above bandgap illumination was applied to control H and VN-complexes, which are the main contributors to the passivation and self-compensation, respectively, in Mg:GaN grown via metalorganic chemical vapor deposition. Secondary ion mass spectrometry measurements confirmed that the total Mg incorporation was unaffected by the process. However, the total H concentration was reduced to similar levels obtained by post-growth thermal activation prior to any annealing treatment. Similarly, the 2.8 eV emission in the photoluminescence spectra, attributed to compensating VN and its complexes, was reduced for the dQFL-process samples. After thermal activation and Ni/Au contact deposition, Hall effect measurements revealed lower resistivities (increased mobilities and free hole concentrations) for dQFL-grown samples with Mg doping concentrations above and below 2 × 1019 cm−3. All these results demonstrate that the dQFL process can effectively reduce the H-passivation and self-compensation of the Mg:GaN films.
Modeling and measuring intracellular displacement during cell penetration
Authors: Sun Yumeng , Liu Yaowei , Zhao Qili , Sun Mingzhu , Zhao Xin
Published: January 2020

Cell penetration is a typical micromanipulation technique widely utilized in many cell biological applications. The significant cell deformation generated during penetration can mechanically damage the cell and even cause the death of the cell. Measuring the intracellular displacement resulting from cell deformation can provide a quantitative evaluation of the mechanical harm done to cells during penetration. The existing labeled intracellular displacement measurement approaches have limitations in spatial resolution and must introduce markers, which cause further harm to the cell. Moreover, label-free methods, such as traditional optical flow methods, are not suitable for measuring the inconsistent intracellular displacement distribution due to cell penetration. This paper presents a label-free noncontact method for measuring the intracellular displacements during penetration. First, based on a finite element simulation, the uneven distribution of intracellular displacements due to penetration was modeled by a quadratic model. Then, by combining the obtained displacement model with the Farnebäck dense optical flow method, a model-based optical flow method was developed to measure intracellular displacements. Finally, the method was used to ascertain the intracellular displacement in porcine oocyte penetration experiments. The forward-backward error of the proposed detection method is less than 0.5 pixels, lower by 49.3% and 26.1%, respectively, compared with two typical Farnebäck optical flow methods. This method could be used to analyze cell damage during penetration. With an appropriate extension, the method may be suitable for measuring the intracellular displacement due to cell manipulations other than penetration.
Detecting network structures from measurable data produced by dynamics with hidden variables
Authors: Shi Rundong , Jiang Weinuo , Wang Shihong
Published: January 2020

Depicting network structures from measurable data is of significance. In real-world situations, it is common that some variables of networks are unavailable or even unknown. These unavailable and unknown variables, i.e., hidden variables, will lead to much reconstruction error, even make reconstruction methods useless. In this paper, to solve hidden variable problems, we propose three reconstruction methods, respectively, based on the following conditions: statistical characteristics of hidden variables, linearizable hidden variables, and white noise injection. Among them, the method based on white noise injection is active and invasive. In our framework, theoretic analyses of these three methods are given at first, and, furthermore, the validity of theoretical derivations and the robustness of these methods are fully verified through numerical results. Our work may be, therefore, helpful for practical experiments.
Persistent and reversible electrostatic control of doping in graphene/hexagonal boron nitride heterostructures
Authors: Quezada-Lopez E. A. , Joucken F. , Chen H. , Lara A. , Davenport J. L. , Hellier K. , Taniguchi T. , Watanabe K. , Carter S. , Ramirez A. P. , Velasco J.
Published: January 2020

Since its first application as a substrate for graphene field effect transistors (FETs), hexagonal boron nitride (hBN) has become a prominent component in two-dimensional (2D) material devices. In addition, hBN has been shown to host defects that can be manipulated to change the electronic properties of adjacent 2D materials. Despite the wide use of such defect manipulations, no focused efforts have been made to further the understanding of defect excitations and their influence in graphene/hBN FETs. In this study, we explore the effect of high electric fields (∼10V/nm) on graphene/hBN FETs and find that persistent and reversible shifts in graphene's charge neutrality point (CNP) occur. By increasing the applied electric field and temperature of our device, we find that this CNP shift is enhanced. With this insight, we propose a mechanism that explains these observations based on Poole–Frenkel emissions from defects in hBN. Finally, we show that such an effect may be suppressed by using graphite as a backgate, thus preventing unintended changes in the electrical properties of graphene/hBN FETs.
Differential Galois integrability obstructions for nonlinear three-dimensional differential systems
Authors: Szumiński W. , Przybylska M.
Published: January 2020

In this short communication, we deal with an integrability analysis of nonlinear three-dimensional differential systems. Right-hand sides of these systems are linear in one variable, which enables one to find explicitly a particular solution and to calculate variational equations along this solution. The conditions for the complete integrability with two functionally independent rational first integrals for B-integrability and the partial integrability are obtained from an analysis of properties of the differential Galois group of variational equations. They have a very simple form of numbers, which is necessary to check whether they are appropriate integers. An application of the obtained conditions to some exemplary nonlinear three-dimensional differential systems is shown.
Development of a prototype radio-frequency system for a radio-frequency quadrupole cooler buncher in the rare isotope science project
Authors: Heo Seongjin , Boussaid Ramzi , Shin Taeksu , Park Young-Ho , Son Hyock-Jun , Moon Jun-Young , Kim Eun-San , Bahng Jungbae
Published: January 2020

Radioactive ion beams produced using the isotope separation on-line method in the Rare isotope Accelerator complex for ON-line (RAON) experiment are to be delivered with a beam emittance of around 3 π mm mrad, an energy spread of less than 10 eV, and a short beam bunch width of around 10 µs to meet the requirements of an electron beam ion source charge breeder. A radio frequency quadrupole cooler buncher (RFQ-CB) will be used to meet the beam quality requirements mentioned above. Our target bunching capacity of RFQ-CB is 108 ions/bunch for various ion species. Such a high bunching capacity requires an RF amplitude of ∼3 kV and a frequency range of 1.5–4.5 MHz in our RFQ-CB design. We designed and tested the prototype RF system composed of a helical resonator, a high-power RF amplifier, and high-voltage probes. To reduce heat load to the high voltage probes, we employed vacuum capacitors serially connected to the ends of helical resonators. In the experiment, we confirmed that our 4.5-µH helical resonators made of a 12-mm copper tube and variable vacuum capacitor with a capacitance range of 120–1120 pF can produce required voltages and frequencies using a 100-W RF amplifier. As a result, with 2.5-W RF output power, we obtained the maximum voltage amplitude of 1 kV at 4.5 MHz, which is equivalent to 6.4 kV with 100-W RF output power.
Morphology and chemical behavior of model CsOx/Cu2O/Cu(111) nanocatalysts for methanol synthesis: Reaction with CO2 and H2
Authors: Hamlyn Rebecca , Mahapatra Mausumi , Orozco Ivan , Hunt Adrian , Waluyo Iradwikanari , White Michael G. , Senanayake Sanjaya D. , Rodriguez José
Published: January 2020

Cs is a promoter of Cu-based catalysts for the synthesis of alcohols from CO2 hydrogenation. Scanning tunneling microscopy and ambient-pressure x-ray photoelectron spectroscopy were used to study the morphology and chemical properties of surfaces generated by the deposition of cesium on Cu2O/Cu(111) and Cu(111) substrates. CsOx nanostructures were formed after Cs metal was deposited on Cu2O/Cu(111) at 300 K. The formed CsOx protrude over the surface of copper oxide by 2–4 Å, with the dimension at the base of the nanostructures being in the range of 1–3 nm. Heating to elevated temperature induced significant changes in the size and dispersion of the CsOx nanostructures, and there was a clear reconstruction of the copper oxide substrate, which then exhibited long range order with a hexagonally packed structure. The as-deposited and annealed surfaces of CsOx/Cu2O/Cu(111) were more reactive toward CO2 than plain Cu2O/Cu(111) or clean Cu(111). However, none of them were stable in the presence of H2, which fully reduced the copper oxide at 400–450 K. In CsOx/Cu(111), the CsOx nanoclusters were dispersed all over the metallic copper in no particular order. The CsOx species had an average width of 2 nm and ∼1 Å height. The CsOx/Cu(111) systems exhibited the highest activity for the binding and dissociation of CO2, suggesting that the CsOx-copper interface plays a key role in alcohol synthesis.
Upgrading the LANSCE accelerator with a SNS RF-driven H− ion source
Authors: Stockli Martin P. , Han Baoxi , Clemmer Mike , Cousineau Sarah M. , Justice Alan , Kang Yoon W. , Murray Syd N. , Pennisi Terry R. , Piller Chip , Stinson Chris M. , Welton Robert F. , Draganic Ilija N. , Batygin Yuri K. , Garnett Robert W. , Kleinjan David , Medina Jacob L. , Montross Joel P. , Rouleau Gary , Dudnikov Vadim
Published: January 2020

The LANSCE accelerator is currently powered by a filament-driven, biased converter-type H− ion source that operates at 10%, the highest plasma duty factor for this type of source, using only ∼2.2 SCCM of H2. The ion source needs to be replaced every 4 weeks, which takes up to 4 days. The measured negative beam current of 12–16 mA falls below the desired 24 mA acceptance of the LANCSE accelerator. The SNS (Spallation Neutron Source) RF-driven, H− ion source injects ∼50 mA of H− beam into the SNS accelerator at 60 Hz with a 6% duty factor and an availability of >99.5% but requires ∼30 SCCM of H2. Up to 7 A h of H− have been produced during the 14-weeks-long source service cycles, which is unprecedented for small emittance, high-current, pulsed H− ion sources. The emittance of the SNS source is slightly smaller than the emittance of the LANSCE source. The SNS source also features unrivaled low Cs consumption and can be installed and started up in <12 h. LANSCE and SNS are working toward the use of SNS H− ion sources on the LANSCE accelerator because they could (a) fill the LANSCE accelerator to its capacity, (b) decrease the source replacement time by a factor of up to 7, and (c) increase source lifetime by a factor of about 4. This paper discusses some of the challenges that emerge when trying to match a different H− source into an existing injector with significantly different characteristics and operating regimes.
DNA-induced changes in traveling wave dielectrophoresis velocity of microparticles
Authors: Nakano Michihiko , Ding Zhenhao , Inaba Masafumi , Suehiro Junya
Published: January 2020

Electrokinetic motion of dielectric microparticles is used in various applications, as the dielectrophoresis (DEP) of the microparticles depends on their polarization in an electric field. This polarization, given by the Clausius–Mossotti (CM) factor, depends on a particle’s surface conductance. This study demonstrates that DNA can induce changes to the nature of the traveling-wave DEP (twDEP) force on a microparticle. As DNA molecules have electric charges on their phosphate backbones, attaching these molecules to the surface of a microparticle increases its surface conductance, resulting in a change in the imaginary part of the CM factor. We conducted image-based analysis of the twDEP velocity of ensembles of microparticles labeled with DNA in the range of 100–10 000 molecules per microparticle. Our experiments revealed that, in addition to being proportional to the number of DNA molecules on a particle, the twDEP velocity of sparsely labeled microparticles (∼100 DNA molecules per microparticle) can be distinguished from that of a bare one, suggesting that the twDEP velocity measurement can be utilized as a DNA detection method.
Effects of parallel and meander configuration on thin-film magnetoimpedance element
Authors: Kikuchi Hiroaki , Tanii Masaru , Umezaki Taisei
Published: January 2020

We investigated the effects of configuration of thin-film magnetoimpedance element on impedance profile. The parallel type and meander type sensor element were fabricated. The parallel line configuration has advantages to reduce a bias field and to enhance total inductance attributable to positive mutual inductance, while a large number of lines brings a decrement of impedance changes. The meander type induces a large demagnetizing effect and decrement of the total inductance due to negative mutual inductance. However, this configuration can utilize the space of the element, which contributes to enhance spatial resolution.
Incoherent light imaging using an optical phased array
Authors: Clevenson Hannah A. , Spector Steven J. , Benney Lucas , Moebius Michael G. , Brown Julian , Hare Alva , Huang Alex , Mlynarczyk Jacqueline , Poulton Christopher V. , Hosseini Ehsan , Watts Michael R. , Dawson Robin , Laine J. P. , Lane Benjamin F.
Published: January 2020

Recent advances in silicon photonics have enabled large-scale optical phased arrays for applications such as beam steering and directional light detection. However, to date, these results have only been applied to coherent light. Many applications, including passive imaging with natural illumination, require operation using incoherent and/or broadband light. Here, we implement an optical phased array designed for these applications using a planar, fractal, path length-matching architecture known as an “H-tree.” We demonstrate electronic beamsteering and natural light imaging using this flat, broadband, photonic-integrated device.