bluuebunny/crossref_metadata_2025 huggingface dataset:
UV Raman chemical imaging using compressed sensing
Authors: Nordberg Markus , Landström Lars
Published: February 2019

A simple and robust set up for achieving hyperspectral imaging in the UV is shown and initial results presented.
Octahedron-shaped three-shell Ln14-substituted polyoxotungstogermanates encapsulating a W4O15 cluster: luminescence and frequency dependent magnetic properties
Authors: Wang Yong-Jiang , Wu Shi-Yu , Sun Yan-Qiong , Li Xin-Xiong , Zheng Shou-Tian
Published: February 2019

The octahedron-shaped three-shell structure of the [(Ln14(H2O)W4(OH)O14)(WO4)4(GeW10O38)6]43− polyanion contains a W4 tetrahedron, a Ln14W4 tetrahedron and a Ge6W60 octahedron.
Nickel-catalyzed alkyl–alkyl cross-coupling reactions of non-activated secondary alkyl bromides with aldehydes as alkyl carbanion equivalents
Authors: Zhu Chenghao , Zhang Junliang
Published: January 2019

A novel nickel-catalyzed alkyl–alkyl cross coupling of non-activated secondary alkyl bromides with aldehydes via hydrazone intermediates has been developed.
Tannic acid capped gold nanoparticles: capping agent chemistry controls the redox activity
Authors: Suherman Alex L. , Zampardi Giorgia , Amin Hatem M. A. , Young Neil P. , Compton Richard G.
Published: February 2019

We report the key role of the capping agent in the detection of metal cations using tannic acid (TA) capped gold nanoparticles at both ensembles (using cyclic voltammetry) and with individual particles (using oxidative and reductive nanoimpacts).
Acyclic 1,2-dimagnesioethanes/-ethene derived from magnesium(i) compounds: multipurpose reagents for organometallic synthesis
Authors: Dange Deepak , Gair Andrew R. , Jones Dafydd D. L. , Juckel Martin , Aldridge Simon , Jones Cameron
Published: February 2019

The sometimes redox reversible 1,2-additions of magnesium(i) dimers across several alkenes and one alkyne yield 1,2-dimagnesioethanes and a 1,2-dimagnesioethene. Treatment of these with bulky amido metal halide precursors affords novel products via three reactivity modes.
Biochemical and structural investigation of sulfoacetaldehyde reductase from Klebsiella oxytoca
Authors: Zhou Yan , Wei Yifeng , Lin Lianyun , Xu Tong , Ang Ee Lui , Zhao Huimin , Yuchi Zhiguang , Zhang Yan
Published: February 2019

Sulfoacetaldehyde reductase (IsfD) is a member of the short-chain dehydrogenase/reductase (SDR) family, involved in nitrogen assimilation from aminoethylsulfonate (taurine) in certain environmental and human commensal bacteria. IsfD catalyzes the reversible NADPH-dependent reduction of sulfoacetaldehyde, which is generated by transamination of taurine, forming hydroxyethylsulfonate (isethionate) as a waste product. In the present study, the crystal structure of Klebsiella oxytoca IsfD in a ternary complex with NADPH and isethionate was solved at 2.8 Å, revealing residues important for substrate binding. IsfD forms a homotetramer in both crystal and solution states, with the C-terminal tail of each subunit interacting with the C-terminal tail of the diagonally opposite subunit, forming an antiparallel β sheet that constitutes part of the substrate-binding site. The sulfonate group of isethionate is stabilized by a hydrogen bond network formed by the residues Y148, R195, Q244 and a water molecule. In addition, F249 from the diagonal subunit restrains the conformation of Y148 to further stabilize the orientation of the sulfonate group. Mutation of any of these four residues into alanine resulted in a complete loss of catalytic activity for isethionate oxidation. Biochemical investigations of the substrate scope of IsfD, and bioinformatics analysis of IsfD homologs, suggest that IsfD is related to the promiscuous 3-hydroxyacid dehydrogenases with diverse metabolic functions.
Collaborative Goals for Communicative Life Participation in Aphasia: The FOURC Model
Authors: Haley Katarina L. , Cunningham Kevin T. , Barry Jennifer , de Riesthal Michael
Published: January 2019

Purpose

Collaborative goal setting is at the heart of person-centered rehabilitation but can be challenging, particularly in the area of aphasia. The purpose of this clinical focus article is to present a step-by-step model for forming a collaborative partnership with clients to develop an intervention plan that follows the client's lead, addresses communicative participation, and integrates multiple treatment strategies.

Method

We introduce the rationale and core features of a 4-step and 4-pronged process (the FOURC model) and illustrate its application through 3 cases of people with aphasia who were treated in outpatient rehabilitation.

Conclusions

The model invites client initiative in a clinically feasible manner while supporting the clinician's role in guiding the intervention based on professional expertise and growing familiarity with the case. Outcomes observed in case studies include strengthened motivation and improved real-life communication.
The Effect of Short-Term Noise Exposure on Audiometric Thresholds, Distortion Product Otoacoustic Emissions, and Electrocochleography
Authors: Lake Alyson Butler , Stuart Andrew
Published: January 2019

Purpose

The purpose of the study was to examine the effect of short-term noise exposure on audiometric thresholds, distortion product otoacoustic emissions (DPOAEs), and electrocochleography (ECochG) as a function of ear and sex.

Method

Preexposure and postexposure measures of audiometric thresholds, DPOAEs, and ECochG indices were examined. Sixteen male and 16 female adults participated. Participants were exposed to a 2000-Hz narrowband noise presented at 105 dBA for 10 min.

Results

Following noise exposure, significantly (p< .0001) larger auditory threshold differences were observed for left ears. Larger auditory threshold differences were also observed for 3000 and 4000 Hz versus 2000 and 6000 Hz. DPOAE absolute amplitude differences increased with decreasingL1,L2level (p< .0001). DPOAE absolute amplitude differences also significantly rose with increasing f2frequencies (p< .0001). Females generally had larger DPOAE absolute amplitude differences than males (p< .05). Summating potential amplitudes were significantly larger for female left ears following noise exposure (p= .03). Left-ear summating potential/action potential amplitude ratios and summating potential/action potential area ratios were increased following noise exposure (p< .05).

Conclusions

Utilizing a test battery to examine the effects of short-term noise exposure can reveal the functional status of different structures in the cochlea. There appears to be a susceptibility of the left ear to short-term loud noise exposure. Findings with respect to a sex susceptibility to short-term loud noise exposure were not strong, as sex differences were only observed for a subset of the conditions.
The Impact of Manipulating Attentional Shifting Demands on Preschool Children With Specific Language Impairment
Authors: Aljahlan Yara , Spaulding Tammie J.
Published: January 2019

Purpose

This study investigated attentional shifting in preschool children with specific language impairment (SLI) compared to their typically developing peers. Children's attentional shifting capacity was assessed by varying attentional demands.

Method

Twenty-five preschool children with SLI and 25 age-matched, typically developing controls participated. A behavioral task measuring attentional shifting within and across multiple dimensions (auditory, linguistic, and visual) was employed. Demands on attentional shifting were increased based on input dimension (low load: staying within dimension; medium load: shifting between 2 dimensions; and high load: shifting among 3 dimensions).

Results

Compared to controls, the group with SLI made more erroneous responses and exhibited longer response times. Although both groups' error rates were similarly affected by shifting compared to nonshifting trials, their response speed was not. The group with SLI exhibited a larger comparative decrement to their response speed in the high–attentional load condition.

Discussion

When demands on attentional shifting increase, children with SLI struggle to shift their attention as efficiently to changing stimuli as their unimpaired peers. Potential implications for the assessment and treatment of this population are discussed.
Bilingual Preschoolers' Spontaneous Productions: Considering Jamaican Creole and English
Authors: Washington Karla N. , Fritz Kristina , Crowe Kathryn , Kelly Brigette , Wright Karem Rachel
Published: January 2019

Purpose

The purpose of this study was to characterize grammatical production in Jamaican Creole (JC) and English using the Index of Productive Syntax (IPSyn; Scarborough,1990) in a sample of typically developing bilingual Jamaicans.

Method

Spontaneous language samples were collected in JC and English from 62 preschoolers aged 4–6 years. Language samples were analyzed for IPSyn subdomains (Total Score, Noun Phrases, Verb Phrases, Questions/Negations, Sentence Structures), mean length of utterance in morphemes, and number of different words. Child and family demographic information were also collected along with nonverbal IQ performance.

Results

IPSyn Total Score in JC and English were significantly correlated, and significant correlations were found between IPSyn subdomains in each language for Noun Phrases, Verb Phrases, and Sentence Structures, but not Questions/Negations. Item analysis for the IPSyn items showed that only 7 of the 56 items did not perform similarly in both languages, with performance on only 2 of these being significantly different. IPSyn scores in both languages were correlated with mean length of utterance in morphemes and number of different words, but only IPSyn JC was correlated with nonverbal IQ and age.

Conclusion

The IPSyn shows promise as a mainstream tool useful in characterizing grammatical productions across languages in typically developing bilingual Jamaican preschoolers.
Comparative analysis of DFT-vdW vs. Coulomb energies for configurational space of layered cathode material at different delithiation levels
Authors: Zolotarev Pavel , Eremin Roman
Published: February 2019

Doping and intercalation ion disordering complicate drastically computer modeling of cathode material properties and behavior during charge-discharge processes. For layered cathode material, parameters of the energetically favored entries of compositional/configurational spaces (CCS) are known to correlate well with the CCS mean values. For the CCS (20760 configurations) of commercially used Li1-xNi0.8Co0.15Al0.05O2, a comparative analysis of electrostatic energies and those obtained using first-principles calculations was performed. Based on the Coulomb energy values, the CCS subgroups containing energetically favorable configurations (ca. 25% of the total number of CCS entries) can be identified reliably for Li deficiencies x ≤ 0.5. Further delithiation results in discrepancies between the title methods demonstrating a limited applicability of the simplified selection procedure. The most apparent reason for this is dispersion interaction which can significantly influence structure behavior and shift energetic properties of the layered cathode materials at high lithium deintercalation levels.
Validation of new device with pneumatic sensor for measurement and recording of arterial blood pressure
Authors: Kuźma Joanna , Tomczuk Krzysztof , Kopczyński Aleksander
Published: February 2019

This paper presents construction, operating principle and initial study of new device for measurement and recording of arterial blood pressure, created at Wroclaw University of Science and Technology. This device is equipped with a pneumatic pressure sensor based on the pneumatic nozzle flapper amplifier principle. During the measurement sensor is applied to the patient’s body, where the pulse is easily palpable. After that, sensor is gradually pressed against to the artery, in order to record peak amplitude. Maximum value of this amplitude corresponds to the real blood pressure waveform. This device was validated according to „International Protocol revision 2010 for the validation of blood pressure measuring devices in adults”.
Two-Point One-Loop Fermionic Amplitudes in Constant Homogeneous Magnetic Field
Authors: Dobrynina Alexandra , Karabanov Ilya , Parkhomenko Alexander , Vassilevskaya Lubov
Published: February 2019

Two-point one-loop fermionic amplitudes modifiled by a constant homogeneous magnetic fileld are studied. In addition to the amplitudes resulted after an insertion of scalar, pseudoscalar, vector and axial-vector fermionic currents, we calculate similar amplitudes with the tensor and (pseudo)scalar vertices. The crossed-field limit of these amplitudes is presented. The tensor current is a fermionic part of the Pauli Lagrangian relevant for the electromagnetic interaction of fermions through the anomalous magnetic moment and its contribution to the photon polarization operator is briefly discussed.
Binding energies of quantum dipole in plane
Authors: Koval Eugene A. , Koval Oksana A.
Published: February 2019

We propose a numerical algorithm based on a discrete variable representation and shifted inverse iterations and apply it to for the analysis of the bound states of edge dislocation modelled by a quantum dipole in a plane. The good agreement with results of recent papers of Amore et al [J. Phys. B 45, 235004 (2012)] was obtained. The error estimates of the previous results of low-lying states energies of other authors were not known due to limitations of the variational approaches and this paper fills this gap presenting calculated low-lying bound states energies by non-variational technique. The probability densities of low-lying states were calculated.
Teaching Practice of Python Programming Course in Big Data Era
Authors: Liu Qing
Published: February 2019

The era of big data poses new challenges and higher requirements for students majoring in economics and management. The programming course should also adapt to the requirements of the era of big data. From the five aspects of content reorganization, comparative teaching, case teaching, WeChat help, and practical teaching, the teaching practice methods of this course are expounded. Through the study of programming courses, students’ professional qualities have been improved, and their competitiveness has been strengthened.
Research on Computing Efficiency of MapReduce in Big Data Environment
Authors: Gao Tilei , Yang Ming , Jiang Rong , Li Yu , Yao Yao
Published: February 2019

The emergence of big data has brought a great impact on traditional computing mode, the distributed computing framework represented by MapReduce has become an important solution to this problem. Based on the big data, this paper deeply studies the principle and framework of MapReduce programming. On the basis of mastering the principle and framework of MapReduce programming, the time consumption of distributed computing framework MapReduce and traditional computing model is compared with concrete programming experiments. The experiment shows that MapReduce has great advantages in large data volume.
Optimal Control Methods of Experiment Times in System-of-Systems Combat Computer Simulation
Authors: Zhao Zhiqiang , Zhou Feiyue
Published: February 2019

In the process of scheme optimization, in order to eliminate the influence of random factor, it needs to conduct computer simulation of Monte Carlo. Therefore, it is proposed to introduce confidence interval into systemof-systems combat simulation, and confirm whether the Monte Carlo simulation finishes according to data sample generated in simulation process. According to characteristic of data sample, extend correspondingly confidence interval method, and under the condition of obtaining the solution meeting accuracy requirements, reduce simulation experiment times as far as possible. The simulation experiment results show that confidence interval extension method is able to possess self-adaptation control to Monte Carlo simulation.
Evaluation of Multilocus Sequence Typing of Cyclospora cayetanensis based on microsatellite markers
Authors: Hofstetter Jessica N. , Nascimento Fernanda S. , Park Subin , Casillas Shannon , Herwaldt Barbara L. , Arrowood Michael J. , Qvarnstrom Yvonne
Published: January 2019

Cyclospora cayetanensis is a human parasite transmitted via ingestion of contaminated food or water. Cases of C. cayetanensis infection acquired in the United States often go unexplained, partly because of the difficulties associated with epidemiologic investigations of such cases and the lack of genotyping methods. A Multilocus Sequence Typing (MLST) method for C. cayetanensis based on five microsatellite loci amplified by nested PCR was described in 2016. The MLST loci had high variability, but many specimens could not be assigned a type because of poor DNA sequencing quality at one or more loci. We analyzed Cyclospora-positive stool specimens collected during 1997–2016 from 54 patients, including 51 from the United States. We noted limited inter-specimen variability for one locus (CYC15) and the frequent occurrence of unreadable DNA sequences for two loci (CYC3 and CYC13). Overall, using the remaining two loci (CYC21 and CYC22), we detected 17 different concatenated sequence types. For four of five clusters of epidemiologically linked cases for which we had specimens from >1 case-patient, the specimens associated with the same cluster had the same type. However, we also noted the same type for specimens that were geographically and temporally unrelated, indicating poor discriminatory power. Furthermore, many specimens had what appeared to be a mixture of sequence types at locus CYC22. We conclude that it may be difficult to substantially improve the performance of the MLST method because of the nucleotide repeat features of the markers, along with the frequent occurrence of mixed genotypes in Cyclospora infections.
Oxidativer Stress im Sport – ein Fall für Antioxidanzien!?
Authors: Gröber Uwe
Published: February 2019

Bei intensiver körperlicher Anstrengung kann es zur Überproduktion von reaktiven Sauerstoff- und Stickstoffverbindungen und damit zu oxidativem Stress kommen. Neben potenziell schädlicher Wirkung auf körpereigene Strukturen haben freie Radikale auch physiologische Aufgaben, u. a. im Rahmen der Infektabwehr, bei der kontraktilen Funktion des Skelettmuskels sowie bei mitochondrialer und vaskulärer Adaptation. Moderates sportliches Training erhöht Konzentration und Aktivität körpereigener antioxidativer Schutzsysteme, sodass trainierte Sportler eine höhere Resistenz gegen oxidativen Stress besitzen. Breitensportler können ihren Bedarf an Antioxidanzien über eine angepasste Ernährung decken, während bei Spitzensportlern in intensiven Trainings- und Wettkampfphasen eine temporäre, laborkontrollierte Supplementierung empfohlen werden kann. Neben Vitamin C kommt bei Leistungssportlern dem Coenzym Q10 eine besondere Bedeutung zu.
Chirurgische Zugänge zum Tibiakopf
Authors: Hissnauer Tim-Nicolas , Krause Matthias , Frings Jannik , Frosch Karl-Heinz
Published: February 2019

Intraartikuläre Tibiakopffrakturen sind häufig komplex und können eine große chirurgische Herausforderung darstellen. Das Ziel der operativen Versorgung ist die anatomische stufenlose Gelenkrekonstruktion. Die Frakturmorphologie erfordert eine frakturspezifische Zugangsstrategie, welche entscheidende Voraussetzung für ein gutes postoperatives Ergebnis ist. Um eine komplette visuelle Einsicht über die frakturierten Gelenkflächen zu erlangen, können die verschiedenen Zugänge kombiniert oder bedarfsweise erweitert werden. Dabei kann durch eine laterale oder mediale femorale Epikondylenosteotomie die Einsicht auf die betroffene Gelenkfläche maßgeblich verbessert werden. Darüber hinaus ist zu beachten, dass dorsale Anteile der Gelenkfläche meist nur mit dorsalen Zugängen visualisiert werden können! Auch die geplante Positionierung von Platten und Schrauben sollte in der Zugangswahl Berücksichtigung finden!
Late Neutrophil Priming Following a Single Session of High-intensity Interval Exercise
Authors: de Oliveira Ottone Vinícius , Costa Karine , Tossige-Gomes Rosalina , de Matos Mariana , Brito-Melo Gustavo , Magalhaes Flavio , Esteves Elizabethe , Amorim Fabiano , Rocha-Vieira Etel
Published: January 2019

This study evaluated the effect of an acute high-intensity interval exercise (HIIE) session on the function of human neutrophils. Twelve sedentary men performed a HIIE session (8 bouts of 60 s at 90% of peak power, intercalated with 75 s of active recovery at 30 W). Neutrophils were collected before, 30 min and 24 h after the exercise session for the evaluation of phagocytic capacity, expression of phagocytic receptors, reactive oxygen species generation, and redox status. 24 h after the HIIE session, an increase was observed in both neutrophil phagocytic capacity and yeast-induced generation of reactive oxygen species, which indicates neutrophil priming in response to an acute HIIE session. Neutrophils also presented an increase in superoxide dismutase activity 24 h after the exercise. Improvement in neutrophil function was accompanied by increased serum levels of IL-8 and increased concentration of plasma lactate dehydrogenase. Our findings show a late activating effect of one HIIE session on neutrophils. We propose that priming of neutrophils by HIIE may play a role in skeletal muscle inflammation after exercise.
Atypical Chemokine Receptors in Cardiovascular Disease
Authors: Gencer Selin , van der Vorst Emiel , Aslani Maria , Weber Christian , Döring Yvonne , Duchene Johan
Published: February 2019

Inflammation has been well recognized as one of the main drivers of atherosclerosis development and therefore cardiovascular diseases (CVDs). It has been shown that several chemokines, small 8 to 12 kDa cytokines with chemotactic properties, play a crucial role in the pathophysiology of atherosclerosis. Chemokines classically mediate their effects by binding to G-protein-coupled receptors called chemokine receptors. In addition, chemokines can also bind to atypical chemokine receptors (ACKRs). ACKRs fail to induce G-protein-dependent signalling pathways and thus subsequent cellular response, but instead are able to internalize, scavenge or transport chemokines. In this review, we will give an overview of the current knowledge about the involvement of ACKR1–4 in CVDs and especially in atherosclerosis development. In the recent years, several studies have highlighted the importance of ACKRs in CVDs, although there are still several controversies and unexplored aspects that have to be further elucidated. A better understanding of the precise role of these atypical receptors may pave the way towards novel and improved therapeutic strategies.
Microsurgical Resection of the Epidermoid Tumor in the Cerebellopontine Angle
Authors: Pojskić Mirza , Arnautović Kenan I.
Published: January 2019

In this video, we demonstrate epidermoid tumor microsurgical resection of the cerebellopontine angle (CPA) performed by the senior author (K.I.A.). Epidermoid tumors arise from ectoderm trapped within/displaced into the central nervous system. They show predilection for CPA Angle (up to 40%), 4th ventricle, suprasellar region, and spinal cord.1 They are the 3rd most common CPA tumor, comprising approximately 7% of CPA pathology. CPA lesions can produce 5th and 7–12th cranial nerve neuropathies.2
3
4 Recurrent episodes of aseptic meningitis caused by cyst content rupture may occur. Symptoms include fever, meningeal irritation, and hydrocephalus. A 26-year-old female presented with headaches. Head magnetic resonance imaging (MRI) revealed right CPA tumor with brain stem compression (Fig. 1, A–C). There was evidence of restricted diffusion in diffusion-weighted imaging, typical of epidermoid tumor. Surgery was performed in prone position with head turned 25 degrees to the ipsilateral side using retrosigmoid craniotomy.5 Tumor was ventral to the 7th and 8th cranial nerve complexes, between the 5th nerve as well as toward the brainstem. The surgical plan was gross total resection with tumor capsule resection to prevent recurrence.6 (Small residuals can be left behind when capsule is adherent to critical structures.) Tumor was adherent to brain stem perforators which were preserved using meticulous dissection. Cranial nerves and vascular structures were also left intact. We irrigated with antibiotic saline and used perioperative treatment to prevent aseptic meningitis. The pathohistological diagnosis revealed epidermoid tumor cyst. Postoperative MRI revealed complete resection (Fig. 1, D–F). The patient recovered fully and was neurologically intact.

The link to the video can be found at: https://youtu.be/LyWl-KZUSGY.
Reduction in Mortality following Elective Major Hip and Knee Surgery: A Systematic Review and Meta-Analysis
Authors: Xu Ke , Chan Noel , Ibrahim Quazi , Kruger Paul , Sinha Smita , Bhagirath Vinai , Ginsberg Jeffrey , Bangdiwala Shrikant , Guyatt Gordon , Eikelboom John , Hirsh Jack
Published: January 2019

Background Systematic reviews reporting time trends in mortality following major orthopaedic surgery are few and have limitations. They reported on only a fraction (< 15%) of the available data and did not investigate potential causes of the reduction in mortality.

Methods We searched PubMed for randomized trials and observational studies, published between 1950 and 2016, reporting on mortality within 3 months of elective total hip and knee replacement (THR/TKR). Mortality risks were estimated for each 5-year interval using a Poisson regression model and presented by study design and mode of prophylaxis. To estimate the mortality reduction unrelated to anti-thrombotic use, we performed a pooled analysis of four thromboprophylaxis strategies for which data spanned five decades.

Results We identified 255 eligible studies, which documented 31,604 deaths among 6,293,954 patients, and found a consistent decline in mortality irrespective of study design and mode of prophylaxis. Mortality declined from 1.15% pre-1980 to 0.24% post-2000, a 78.7% relative risk reduction (95% confidence interval [CI]: 74.7–82.1%) in randomized and cohort studies. Furthermore, our data showed a 74.4% (95% CI: 68.7–79.0%) relative reduction in mortality independent of the methods of prophylaxis, thereby indicating that improvements in peri-operative care unrelated to anti-thrombotic prophylaxis played a major role in such reduction.

Conclusion Mortality following elective THR/TKR has markedly declined over the past 50 years and is now low irrespective of which prophylactic agent is being used. Although anti-thrombotic prophylaxis may have contributed, other improvements in peri-operative care played a major role in the mortality reduction.
Introduction to the Audiological Evaluation: Case-Based Applications to Patients with Skull Base Disease
Authors: Dumanch Kelsey , Poling Gayla
Published: February 2019

Objectives To provide an introduction to the role of audiological evaluations with special reference to patients with skull base disease.

Design Review article with case-based overview of the current state of the practice of diagnostic audiology through highlighting the multifaceted clinical toolbox and the value of mechanism-based audiological evaluations that contribute to otologic differential diagnosis.

Setting Current state of the practice of diagnostic audiology.

Main Outcome Measures Understanding of audiological evaluation results in clinical practice and value of contributions to interdisciplinary teams to identify and quantify dysfunction along the auditory pathway and its subsequent effects.

Results Accurate auditory information is best captured with a test battery that consists of various assessment crosschecks and mechanism-driven assessments.

Conclusion Audiologists utilize a comprehensive clinical toolbox to gather information for assessment, diagnosis, and management of numerous pathologies. This information, in conjunction with thorough medical review, provides mechanism-specific contributions to the otologic and lateral skull base differential diagnosis.
Universal Electrocardiographic Screening for Long QT Syndrome in Hospitalized Neonates
Authors: Kaemingk Bethany D. , Ulrich Timothy J. , Li Man , Carey William A. , Ellsworth Marc A.
Published: February 2019

Objective Long QT syndrome (LQTS) is a known cause of unexpected death, leading some to recommend routine neonatal electrocardiographic (ECG) screening. We used continuous electronic heart rate corrected QT interval (QTc) monitoring to screen for interval prolongation in a cohort of hospitalized neonates to identify those at a risk of having LQTS. We hypothesized that this screening method would yield an acceptable positive predictive value (PPV).

Study Design A cohort of 589 infants hospitalized in a level II neonatal intensive care unit were screened through continuous electronic QTc monitoring linked to an investigator-designed, computerized data sniffer. Screening was conducted from days-of-life 3 through 7 or until hospital discharge. The data sniffer alerted investigators for a 24-hour average QTc of ≥475 ms. Positively screened patients were further evaluated with 12-lead ECG.

Results Positive screens were obtained in 5.6% of patients, all of whom had negative follow-up ECG testing (PPV = 0%). Furthermore, one-quarter of positively screened neonates underwent echocardiography based on ECG findings, none of which identified clinically relevant pathology.

Conclusion Electronic monitoring of QTc in hospitalized neonates during the first week of life was not an efficient way to identify those at a risk of having LQTS. Conversely, screening triggered unnecessary testing.
Frontal Sinus Fractures: Evolving Clinical Considerations and Surgical Approaches
Authors: Arnold Mark A. , Tatum Sherard A.
Published: February 2019

Frontal sinus fractures are an uncommon injury of the maxillofacial skeleton, and account for 5–15% of all maxillofacial fractures. As the force of impact increases, fractures may extend beyond the anterior table to involve adjacent skull, posterior table and frontal sinus outflow tract (FSOT). Fractures at these subsites should be evaluated independently to assess the need for and type of operative intervention. Historically, these fractures were managed aggressively with open techniques resulting in obliteration or cranialization. With significant injuries, these approaches are still indispensable. However, the treatment of frontal sinus fractures has changed dramatically over the past half-century, and recent case series have demonstrated favorable outcomes with conservative management. Concurrently, there has been an increasing role of minimally invasive endoscopic techniques, both for primary and expectant management, with a focus on sinus preservation. Here, we review the diagnosis and management of frontal sinus fractures, with an emphasis on subsite evaluation. Following a detailed assessment, an appropriate treatment strategy is selected from a variety of open and minimally invasive approaches available in the surgeon's armamentarium.
Clinical Predictors Leading to Change of Initial Conservative Treatment of 836 Vestibular Schwannomas
Authors: Kleijwegt Maarten , Bettink Floris , Malessy Martijn , Putter Hein , van der Mey Andel
Published: February 2019

Objective This study was aimed to determine the role of clinical presentation and tumor characteristics in vestibular schwannoma (VS) at diagnosis, initially treated with conservative management.

Design The study was designed as a retrospective chart review.

Setting The study was prepared at national tertiary referral center for VS patients.

Participants A total of 836 VS patients, initially treated conservatively, were included.

Main Outcome Measures Patient characteristics: age at diagnosis, gender, frequency, and duration of, hearing loss, tinnitus, balance disorder (unsteadiness, dizziness, and vertigo), respectively; and tumor characteristics: laterality, growth, cystic component, and location were analyzed in relation to tumor size at diagnosis and change in treatment strategy.

Results In total, 169 (20%) patients had a change in treatment strategy. Factors at diagnosis that had a high influence on intervention were a short duration of hearing loss (hazard ratio [HR]: 4.8, p < 0.001) and cystic tumors (HR = 2.6, p < 0.001). Balance disorders and extracanalicular (EC) tumor location have a medium influence on intervention (HR = 1.6, p < 0.01). Tumour growth was seen in 55% of the intervention group; we found a significant correlation with a short duration of hearing loss. Cystic VS was significantly higher between the medium and large tumors, 24.3% and 38.1%. (p = 0.001), respectively.

Conclusions Patients with a short duration of hearing loss, balance disorders, EC located tumors, and cystic tumors have a significantly higher chance of a change in treatment strategy. Large tumor size at diagnosis and a cystic component were related to age > 65 years at diagnosis.
An x-band continuous wave saturation recovery electron paramagnetic resonance spectrometer based on an arbitrary waveform generator
Authors: McPeak Joseph E. , Quine Richard W. , Eaton Sandra S. , Eaton Gareth R.
Published: February 2019

An X-band (ca. 9-10 GHz) continuous wave saturation recovery spectrometer to measure electron spin-lattice relaxation (T1) was designed around an arbitrary waveform generator (AWG). The AWG is the microwave source and is used for timing of microwave pulses, generation of control signals, and digitizer triggering. Use of the AWG substantially simplifies the hardware in the bridge relative to that in conventional spectrometers and decreases the footprint. The bridge includes selectable paths with different power amplifications to permit experiments requiring hundreds of milliwatts to fractions of nanowatts for the pump and observe periods. The signal is detected with either a single or quadrature-output double balanced mixer. The system can operate with reflection or crossed-loop resonators. The source noise from the AWG was decreased by addition of a Wenzel high-stability clock. The source is sufficiently stable that automatic frequency control is not needed. The spectrometer was tested with samples that contained 1 × 1015 to 8 × 1017 spins and have T1 between a few hundred ns and hundreds of μs. Excellent signal-to-noise ratio was obtained with acquisition times of 2–90 s. Signal-to-noise performance is similar to that of a conventional saturation recovery spectrometer with a solid-state source. The stability and data reproducibility are better than with conventional sources. With replacement of frequency-sensitive components, this spectrometer can be used to perform saturation recovery measurements at any frequency within the range of the AWG.
Numerical simulation of magnetized jet creation using a hollow ring of laser beams
Authors: Lu Y. , Tzeferacos P. , Liang E. , Follett R. K. , Gao L. , Birkel A. , Froula D. H. , Fu W. , Ji H. , Lamb D. , Li C. K. , Sio H. , Petrasso R. , Wei M. S.
Published: February 2019

Three dimensional FLASH magneto-hydrodynamic modeling is carried out to interpret the OMEGA laser experiments of strongly magnetized, highly collimated jets driven by a ring of 20 OMEGA beams. The predicted optical Thomson scattering spectra and proton images are in good agreement with a subset of the experimental data. Magnetic fields generated via the Biermann battery term are amplified at the boundary between the core and the surrounding of the jet. The simulation predicts multiple axially aligned magnetic flux ropes with an alternating poloidal component. Future applications of the hollow ring configuration in laboratory astrophysics are discussed.
Finite-size scaling study of aging during coarsening in non-conserved Ising model: The case of zero temperature quench
Authors: Vadakkayil Nalina , Chakraborty Saikat , Das Subir K.
Published: February 2019

Following quenches from random initial configurations to zero temperature, we study aging during evolution of the ferromagnetic (nonconserved) Ising model towards equilibrium, via Monte Carlo simulations of very large systems, in space dimensions d = 2 and 3. Results for the two-time autocorrelations exhibit scaling with respect to ℓ/ℓw, where ℓ and ℓw are the average domain sizes at t and tw (⩽t), the observation and waiting times, respectively. The scaling functions are shown to be of power-law type for ℓ/ℓw → ∞. The exponents of these power-laws have been estimated via a novel application of the finite-size scaling method and discussed with reference to the available results from non-zero temperatures. While in d = 2 we do not observe any temperature dependence, in the case of d = 3 the outcome for quench to zero temperature appears different from the available results for high temperatures, which we explain via structural consideration. We also present results on the freezing phenomena that this model exhibits at zero temperature. Furthermore, from simulations of a very large system, thereby avoiding the freezing effect, it has been confirmed that the growth of average domain size in d = 3, that remained a puzzle in the literature, follows the Lifshitz-Allen-Cahn law in the asymptotic limit. We presented results for different acceptance probabilities for the spin flip trial moves. We observe slower growth for lower probability, even though the asymptotic exponent remains the same.
Time resolved measurements of droplet preferential concentration in homogeneous isotropic turbulence without mean flow
Authors: Lian H. , Chang X. Y. , Hardalupas Y.
Published: February 2019

An experimental investigation of the time-dependent spatial distribution of droplet concentration in a “box” of stationary homogeneous and isotropic turbulence without mean flow was performed for polydispersed droplet clouds with a wide range of mean droplet diameters and droplet size distributions, characterized by a representative Stokes number, based on the droplet arithmetic diameter and the Kolmogorov time scale of the flow, varying between 0.2 and 6, and for turbulent Reynolds numbers of 98, 127, 147, and 235. A novel morphological tracking scheme was used to provide temporal tracking of droplet clusters according to cluster morphological features. The tracking scheme was based on Voronoï space tessellation, multivariate kernel density estimation, and mean shift feature space tracking. The developed tracking scheme was used to establish the relationship between the morphological features of droplet clusters, i.e., number of clusters per unit area and cluster length scales, and the velocity of droplet clusters. The time scale of the droplet clusters increased with both the turbulent Reynolds number and the Stokes number, but its dependence was stronger on the turbulence level. In addition, the effect of filling factors of turbulent flows by turbulent structures on droplet clustering was discussed, which led to suggestions of potential flow control methods to mitigate droplet preferential concentration.
Materials processing using radio-frequency ion-sources: Ion-beam sputter-deposition and surface treatment
Authors: Becker M. , Gies M. , Polity A. , Chatterjee S. , Klar P. J.
Published: February 2019

The capabilities of ion-beam techniques for thin-film processing, i.e., for materials deposition by ion-beam sputtering and surface treatment, are reviewed. The basic interaction mechanisms between ions and solids are summarized and related to materials processing by ion sources. Typical geometries of ion sources, targets, and samples are discussed for corresponding experimental apparatus. The versatility of ion-beam techniques in the preparation of thin films and multilayer structures is illustrated by several examples: ion-beam sputter-deposition of various binary oxide materials (including crystalline MgO, NiO, ZnO, SnxOy, and CuxOy) as well as combinatorial growth of materials libraries of amorphous ternary oxides. Furthermore, controlled ion-beam etching of surfaces is discussed.
Photo-acoustic detection of chirality in metal-polystyrene metasurfaces
Authors: Petronijević E. , Leahu G. , Li Voti R. , Belardini A. , Scian C. , Michieli N. , Cesca T. , Mattei G. , Sibilia C.
Published: February 2019

Nowadays, nanophotonics aims towards low-cost chip-scale devices that can tailor electromagnetic properties, one of which is the control of circular polarization at the nanoscale. Here, we demonstrate the chiral properties of metasurfaces produced by means of nanosphere lithography combined with tilted metal deposition. We apply the photo-acoustic technique to characterize the circular dichroism (CD) at 633 nm of polystyrene nanospheres covered by three different metals: Au- and Cr-covered samples show extrinsic chiral behavior, while the Ag-covered sample shows CD at normal incidence, characteristic of intrinsic chirality. As the experimental data are in good agreement with numerical predictions, we believe that such design can be optimized to get efficient circularly polarized detection at the nanoscale.
Enhancement of perpendicular magnetic anisotropy and spin-orbit torque in Ta/Pt/Co/Ta multi-layered heterostructures through interfacial diffusion
Authors: Wang Rui , Xiao Zhengyu , Liu Huihui , Quan Zhiyong , Zhang Xiao , Wang Meimei , Wu Mingzhong , Xu Xiaohong
Published: January 2019

Heavy metal/ferromagnetic metal bi-layered structures that exhibit both strong perpendicular magnetic anisotropy (PMA) and large spin-orbit torque (SOT) efficiency have high potential in high-density, low-power memory, and logic device applications. Here, we report the enhancement of PMA and SOT in Ta/Pt/Co/Ta multi-layered heterostructures through interfacial diffusion. The structures can exhibit PMA fields of 9100 Oe at 300 K and 14100 Oe at 10 K and an effective spin Hall angle (SHA) of 0.61 ± 0.03 at 300 K. These values are larger than the corresponding values reported previously for similar heterostructures. The current-induced magnetization switching was demonstrated. The critical switching current density is on the order of 106 A/cm2, and the corresponding switching efficiency is higher than that reported for similar structures. X-ray absorption spectroscopy and high-angle annular dark-field scanning transmission electron microscopy analyses suggest a strong correlation between the observed PMA and SOT enhancement and the interfacial diffusion during the sputtering growth of the samples. It is very likely that the interfacial diffusion gives rise to enhanced spin-orbit coupling at the interface, while the latter results in enhancement in the PMA, SHA, and switching efficiency in the structure.
Wide dynamic range magnetic field cycler: Harnessing quantum control at low and high fields
Authors: Ajoy A. , Lv X. , Druga E. , Liu K. , Safvati B. , Morabe A. , Fenton M. , Nazaryan R. , Patel S. , Sjolander T. F. , Reimer J. A. , Sakellariou D. , Meriles C. A. , Pines A.
Published: January 2019

We describe the construction of a fast field cycling device capable of sweeping a 4-order-of-magnitude range of magnetic fields, from ∼1 mT to 7 T, in under 700 ms, and which is further extendable to a 1 nT-7 T range. Central to this system is a high-speed sample shuttling mechanism between a superconducting magnet and a magnetic shield, with the capability to access arbitrary fields in between with high resolution. Our instrument serves as a versatile platform to harness the inherent dichotomy of spin dynamics on offer at low and high fields—in particular, the low anisotropy, fast spin manipulation, and rapid entanglement growth at low field as well as the long spin lifetimes, spin specific control, and efficient inductive measurement possible at high fields. Exploiting these complementary capabilities in a single device opens up applications in a host of problems in quantum control, sensing, and information storage, besides in nuclear hyperpolarization, relaxometry, and imaging. In particular, in this paper, we focus on the ability of the device to enable low-field hyperpolarization of 13C nuclei in diamond via optically pumped electronic spins associated with nitrogen vacancy defect centers.
Micro-dynamics of neutral flow induced dusty plasma flow
Authors: Arora Garima , Bandyopadhyay P. , Hariprasad M. G. , Sen A.
Published: February 2019

We present a detailed experimental study of gas flow induced motion of dust particles in a DC glow discharge plasma. The characteristics of the dust dynamics are investigated as a function of the differential gas flow rate, the background neutral pressure, the dust particle size, and the neutral species of the gas. The experiments have been carried out in the table top Dusty Plasma Experimental (DPEx) device in which a plasma is created between a disk shaped anode and a grounded cathode in a Π-shaped Pyrex glass tube. The asymptotic steady state flow velocity of the injected micron sized dust particles is found to increase with an increase in neutral flow velocity and decrease with an increase in the background pressure. Furthermore, this velocity is seen to be independent of the size of the dust particles, but decreases with an increase in the mass of the background gas. A simple theoretical model, based on estimates of the various forces acting on the dust particles, is used to elucidate the role of neutrals in the flow dynamics of the dust particles. Our experiments thus provide a detailed microscopic understanding of some of the past phenomenological observations of dust flows in the DPEx device and can prove useful in future experimental implementations of dust flow experiments.
Bubbles in water under stretch-induced cavitation
Authors: Min Sa Hoon , Berkowitz Max L.
Published: February 2019

When a finite sample of water experiences tension, it may develop voids (bubbles). We present here a result for the work (Helmholtz free energy change) that needs to be done for the creation of a bubble in fixed volume of water under tension and show that this result depends on the general form of stress–strain relationship. We observe that it is very important to include the curvature-dependent surface tension into consideration in order to explain bubble stability. The analytical result we obtained for the free energy allows us to make prediction for the values of critical and stable radii of the bubbles. We also performed simulations on the TIP4P/2005 water model and observed creation of bubbles in water under stretch. Combining analytical results obtained from our thermodynamic description with the results from computer simulations allowed us to determine the two parameters that describe the curvature-dependent surface tension and also to find the values of critical and stable bubble radii. We also determined the values of critical bubble radii by using mean first-passage time calculations.
Interface of GaP/Si(001) and antiphase boundary facet-type determination
Authors: Lenz A. , Supplie O. , Lenz E. , Kleinschmidt P. , Hannappel T.
Published: January 2019

GaP/Si(001) virtual substrates are highly interesting for solar cells and optoelectronic device applications. While antiphase disorder at the resulting surface of the virtual substrate—after a few tens of nm GaP—can be suppressed, the structural and electronic properties of the actual GaP-to-Si interface and of the antiphase domains within the GaP are still of high importance. Here, we compare scanning tunneling microscopy data of the prepared Si(001) 2° off-oriented substrate with cross-sectional scanning tunneling microscopy data (XSTM) taken after GaP0.98N0.02/GaP growth. Besides regions where an intermixing of Si with GaP cannot be excluded, we also observe sections with a quite abrupt appearance. In addition, basic knowledge for use of contrast mechanisms occurring in XSTM experiments at antiphase boundaries will be established in order to understand their atomic structure. Thereby, we present a structural model for an entire antiphase domain cross section, including antiphase boundary facet-type determination. Furthermore, we find indications that the majority of the antiphase boundaries within this sample exhibit an equal number of so-called wrong bonds and that XSTM will allow to directly determine the electronic impact of the antiphase boundaries on its surroundings in the future.