bluuebunny/crossref_metadata_2025 huggingface dataset:
Dyspnoe aufgrund eines Fremdkörper-Embolisats nach perkutaner Vertebroplastie
Authors: Bauer M. , Kröger U. , Lenga P.
Published: October 2020

Anamnese und klinischer Befund Notfallmäßige Vorstellung eines 66-jährigen Mannes in der interdisziplinären Notaufnahme aufgrund rechtsseitiger und z. T. atemabhängiger Thoraxschmerzen. Die Beschwerden bestanden seit mehreren Tagen und hatten einen progredienten Charakter. Purulenter Auswurf und Fieber wurden verneint. Anamnestisch war eine COPD mit gelegentlichen pulmonalen Exazerbationen bekannt. Mehrere Wochen vor dem aktuellen Ereignis war eine ambulant erworbene Pneumonie antibiotisch therapiert worden. Zudem berichtete der Patient über mehrere operative Eingriffe im Bereich der Wirbelsäule in den letzten Monaten.

Untersuchungen und Diagnose In der transthorakalen Echokardiografie (TTE) Nachweis eines Fremdkörpers (Palacos) im rechten Ventrikel, welcher sich in der ergänzenden CT-Untersuchung des Thorax und der transösophagealen Echokardiografie (TEE) als eine Zahnstocher-ähnliche Struktur bestätigte.

Therapie und Verlauf Extraktion des Fremdkörpers mittels rechtsanteriorer Mini-Thorakotomie. In der Folge Ausbildung eines iatrogenen Pneumothorax mit beidseitiger nosokomialer Pneumonie und Drainagenversorgung. Nach kurzfristiger Rekonvaleszenz erneute Wiedervorstellung mit beidseitigen pulmonalen Infiltraten. Unter invasiver Beatmung erneute Diagnose eines linksseitigen Pneumothorax, welcher mit einer Bülau-Drainage versorgt wurde. Aufgrund des Nachweises von positiven Blutkulturen erneute Durchführung einer TEE-Untersuchung. Erstdiagnose einer Trikuspidalklappenendokarditis. Trotz eines erfolgreichen operativen biologischen Trikuspidalklappenersatzes mit Anlage einer epikardialen Schrittmacherelektrode verstarb der Patient ungefähr ein ¾ Jahr, nachdem er wegen einer Dyspnoe-Symptomatik notfallmäßig vorstellig wurde.

Diskussion Dieser Fall zeigt, dass eine typische klinische Symptomatik, die mit einer vorbekannten chronischen Erkrankung assoziiert ist, immer wieder an andere und seltenere Erkrankungen denken lassen muss. Auch alltägliche diagnostische und therapeutische Verfahren sind mit einem Restrisiko möglicher Komplikationen behaftet.
Stellenwert der intraoperativen optischen Kohärenztomografie in der Netzhautchirurgie. Teil 2: contra
Authors: Szurman Peter
Published: October 2020

Eine der kontroversesten Diskussionen in der Netzhautchirurgie wird derzeit über den Stellenwert der intraoperativen optischen Kohärenztomografie (iOCT) geführt. Hintergrund ist der Wunsch, den 2-dimensionalen Fundusblick des Operateurs mit der geschichteten Tiefeninformation der OCT zu kombinieren, um eine Art 4-dimensionale „Augmented Reality“ (3-D plus Veränderung über die Zeit) zu erreichen. Dies soll feine Strukturen, die dem Blick des Operateurs bisher verborgen sind, sichtbar machen. Deshalb erscheint die Netzhautchirurgie prädestiniert für den Einsatz einer iOCT zu sein. Die große Hoffnung liegt darin, dass ein dynamisches Live-3-D-Bild mit Echtzeit-Feedback dem Operateur zusätzliche Informationen liefert und die Sicherheit verbessert. So faszinierend die iOCT-Technologie auf den ersten Blick ist, so enttäuscht sie doch im klinischen Alltag, gerade in der Makulachirurgie. Sie liefert nur selten Informationen, die ohne iOCT nicht erzielbar wären oder durch
präoperative Diagnostik nicht in wesentlich besserer Qualität vorlägen. Hoffnungsvoll sind einige Sonderindikationen, die insbesondere die subretinale Chirurgie betreffen.
Zeitlicher Aufwand einer gefäßchirurgischen Routineoperation bei einer Patientin mit COVID-19 – ein Fallbericht
Authors: Mühlberger Dominic , Mumme Achim , Hummel Thomas
Published: October 2020

Hintergrund Der pandemische Verlauf von COVID-19 stellt Gesundheitssysteme und Krankenhäuser weltweit vor neue Herausforderungen. Elektive chirurgische Eingriffe werden verschoben, um internistische und intensivmedizinische Kapazitäten zu erhöhen. Dennoch werden auch chirurgische Fachdisziplinen mit SARS-CoV-2 infizierten Patienten konfrontiert werden.

Methode Wir berichten über unseren ersten Fall einer Patientin mit einer gesicherten SARS-CoV-2-Infektion und einer notwendigen dringlichen Portexplantation und den damit verbundenen erhöhten zeitlichen Arbeitsaufwand.

Ergebnisse Obwohl eine Portentfernung ein gefäßchirurgischer Routineeingriff ist und ein geringer chirurgischer Arbeitsaufwand sowohl in der Vorbereitung als auch in der eigentlichen Operation besteht, stellen Patienten mit einer SARS-CoV-2-Infektion eine Ausnahme dar. Die gesamte Operationsdauer betrug 125 min, bedingt durch die erhöhten intraoperativen Hygienemaßnahmen, während der durchschnittliche OP-Aufenthalt der letzten 5 Portentfernungen lediglich 50 min betrug. Auch in der postoperativen Nachbehandlung zeigten sich deutlich verlängerte Behandlungszeiten.

Schlussfolgerung COVID-19-positive Patienten werden auch in Zukunft für chirurgische Fachdisziplinen eine Herausforderung darstellen, nicht aufgrund von fachspezifischen Fragestellungen, sondern vielmehr aufgrund der logistischen und hygienischen Maßnahmen im Umfeld des chirurgischen Eingriffs.
Webbasierte Selbsthilfe zur Stimmungsverbesserung in der Wartezeit auf ambulante Psychotherapie – Eine qualitative Erhebung der Teilnehmerperspektive
Authors: Grünzig Sasha-Denise , Teigelkötter Wiebke , Bengel Jürgen , Krämer Lena Violetta
Published: October 2020

Ziel der Studie Patienten warten in Deutschland durchschnittlich 5 Monate auf den Beginn einer ambulanten Psychotherapie. Begleitete webbasierte Selbsthilfeinterventionen können depressive Symptome in der Wartezeit reduzieren. Ziel der Studie ist zu untersuchen, wie Betroffene die Teilnahme an einer webbasierten Intervention zur Stimmungsverbesserung erleben.

Methodik Patienten auf den Wartelisten kooperierender Hochschulambulanzen wurden dazu eingeladen, im Rahmen einer Studie eine webbasierte Intervention zur Stimmungsverbesserung zu nutzen. Elf Teilnehmende der Intervention wurden in einem qualitativen Telefoninterview zu ihren Erfahrungen mit der Maßnahme befragt. Die Daten wurden entsprechend den Prinzipien der Grounded Theory analysiert.

Ergebnisse Aus den Daten konnten 3 Kategorien extrahiert werden, welche das Erleben der Teilnehmenden hinsichtlich ihrer Erwartungen, ihrer Erfahrungen sowie ihrer Adhärenz beschreiben. Die webbasierte Intervention wurde sehr unterschiedlich erlebt und sowohl mit positiven als auch negativen Erfahrungen verbunden. Die Teilnehmenden ließen sich anhand der beschriebenen Kategorien in 3 Nutzertypen gruppieren: Den selbstständigen Typus, den überforderten Typus und den anspruchsvollen Typus.

Diskussion Nicht alle Patienten machen gleichermaßen gute Erfahrungen mit der Intervention und einige scheitern an der Umsetzung. Um Patienten bestmöglich auf die Nutzung der Intervention vorzubereiten, sollten sie vorab noch ausführlicher über die Handhabung und Ziele der Intervention aufgeklärt werden. Interventionen sollten individuell entsprechend des Unterstützungsbedarfs von Patienten implementiert werden, um positive Erfahrungen zu ermöglichen und adhärenzfördernd zu wirken.
Non-HDL-Cholesterin
Authors: Adam Leonie , Bobbert Thomas
Published: October 2020

Die diabetische Stoffwechsellage korreliert häufig mit einer Dyslipidämie, die sich typischerweise durch erhöhte Triglyzeride, niedriges HDL-Cholesterin und eine hohe Konzentration an small dense LDL-Cholesterin (LDL: low-density lipoprotein) auszeichnet. Zur kardiovaskulären Risikostratifizierung bei Diabetes mellitus Typ 2 eignet sich die Verwendung von Non-HDL-Cholesterin (HDL: high-density lipoprotein), um sämtliche potenziell atherogene Lipoproteine – VLDL (very-low-density lipoprotein), IDL (intermediate-density lipoprotein), LDL, Lipoprotein(a), Chylomikronen, Remnants – zu erfassen.
Postoperative Behaviour after Primary Strabismus Surgery in Children: Is There an Influence of Intraoperative Topical Anaesthesia?
Authors: Karstädt Nadja , Crozier Thomas A. , Horn Maren , Naxer Sabine , Schittkowski Michael P.
Published: October 2020

Introduction The course of the recovery phase after general anaesthesia, during which consciousness and pain gradually return, is essentially determined by the choice of anaesthetic drug, and its total dose or duration of application. This phase is often complicated by more or less severe agitation, especially in children. In the present study we investigated whether the application of a topical anaesthetic to the conjunctiva at the end of a strabismus operation had a positive effect on the recovery behaviour of the child.

Patients/Methods This prospective, randomised, blinded study was conducted with 50 healthy, ASA class I or II children, aged 3 to 8 years undergoing their first strabismus operation. Following the surgeonʼs randomisation two drops of a 0,5% tetracaine-HCl ophthalmic solution were applied to the operated conjunctiva three times at 30-s intervals immediately following wound closure. The postoperative evaluation encompassed heart rate, as well as COMFORT and CHEOPS scores. The first assessment was directly postoperatively with repetitions at 15, 30, 45, 60, 75, 90 and 120 min, as well as on the day after surgery.

Results The CHEOPS scores did not differ significantly between children with or without topical anaesthesia at any time during the observation period. The COMFORT scores revealed a slight, but non-significant analgesic effect at 15 and 30 min. The 60 min score showed the opposite effect, possibly indicating a slight disadvantage of the topical anaesthesia. There were no significant differences with regard to time to first request for additional systemic analgesia, to the total dose of systemic pain medication, or to when the patient was eligible for discharge to the ward.

Conclusion The application of topical tetracaine-HCl immediately after wound closure had no positive effects on the course of the postoperative recovery period after strabismus surgery in children. There was no evidence of an effect on pain or emergence agitation.
Digital and Technical Developments in the Amblyopia Therapy
Authors: Schramm Charlotte , Wenner Yaroslava
Published: October 2020

The digital media becomes more and more common in our everyday lives. So it is not surprising that technical progress is also leaving its mark on amblyopia therapy. New media and technologies can be used both in the actual amblyopia therapy or therapy monitoring. In particular in this review shutter glasses, therapy monitoring and analysis using microsensors and newer video programs for amblyopia therapy are presented and critically discussed. Currently, these cannot yet replace classic amblyopia therapy. They represent interesting options that will occupy us even more in the future.
Aerobic Oxidation of Phosphite Esters to Phosphate Esters by Using an Ionic-Liquid-Supported Organotelluride Reusable Catalyst
Authors: Koguchi Shinichi , Mihoya Aya , Shibuya Yuga , Ito Akane , Toyoda Anna , Oba Makoto
Published: October 2020

We describe the synthesis of an ionic-liquid (IL)-supported organotelluride catalyst and its application as a recyclable catalyst for the aerobic oxidation of phosphite esters to phosphate esters. This method shows high conversion rates, allows the ready isolation and purification of the resulting products, and exhibits good reusability of the catalyst.
Impairment of Uterine Contractility Is Associated with Unexplained Infertility
Authors: Hunt Sarah , Abdallah Karim S. , Ng Ernest , Rombauts Luk , Vollenhoven Beverley , Mol Ben W.
Published: October 2020

The uterine junctional zone represents the juncture between endometrium and myometrium. The junctional zone is hormonally dependent and displays continuous peristaltic activity throughout the menstrual cycle in the nonpregnant state which is concerned with sperm transport and embryo implantation. Peristalsis may be observed using various invasive and noninvasive modalities, of which ultrasound is the most readily applied in the clinical setting. Women with pelvic pathology display alterations in uterine peristalsis which may contribute to infertility. Characterization of peristalsis in infertility subgroups, the development of a subjective peristalsis tool, and the application of potential therapeutics to an assisted reproductive treatment setting are the subject of ongoing investigation. Meta-analysis indicates a potential role for oxytocin antagonist in the improvement of fertility treatments.
Are Plain X-Rays Necessary in the Diagnosis of De Quervain's Tenosynovitis?
Authors: Henry Tyler W. , Tulipan Jacob E. , Beredjiklian Pedro K. , Matzon Jonas L. , Lutsky Kevin F.
Published: October 2020

Background The routine use of plain radiography represents a significant expenditure and has been proven unnecessary in several orthopedic conditions. The utility of plain radiographs in the diagnosis of De Quervain's tenosynovitis (DeQ) is not clear.

Questions/Purpose This study evaluates whether plain radiographic findings routinely predict the need for surgery or alter treatment courses in the initial diagnosis of DeQ.

Patients and Methods A total of 200 patients who received wrist X-rays and had a diagnosis of DeQ were retrospectively selected at random. Their images were evaluated for relevant findings, including radial styloid abnormalities, arthritis, and tendon calcification. A chart review was performed to determine whether these X-rays altered the treatment courses.

Results Of the 200 patients, 141 (69.1%) cases had at least one positive radiographic finding. Carpometacarpal joint (CMC) arthritis was the most common finding, seen in 63 (30.9%) cases. Of all patients, 141 (69.1%) were treated with corticosteroid injection only, 54 (26.5%) with corticosteroid injection and ultimately surgery, and 9 (4.4%) with surgery alone. There were no significant differences in the rates of surgery with positive X-ray findings. There were no cases in which radiographic findings resulted in a change in management, per the report of the treating physician.

Conclusions Despite the high proportion of positive findings on X-ray, no radiographic findings altered the course of treatment in patients with isolated DeQ. Obtaining plain radiographs for isolated DeQ represents a significant cost and should be reserved for cases in which the results are preemptively deemed likely to influence the treatment course.

Level of Evidence This is a level IV study.
Caudal Cruciate Ligament Rupture in an Adult Dog 8.5 Years Post Juvenile Tibial Plateau Cranial Hemiepiphysiodesis
Authors: Petazzoni Massimo , Dallago Melania , Ferretti Antonio
Published: October 2020

The aim of this study was to report a case of caudal cruciate ligament rupture in a 9-year-old dog who underwent juvenile tibial plateau cranial hemiepiphysiodesis that was performed to treat a partial cranial cruciate ligament rupture and excessive tibial plateau angle. A 9-year-old, 45 kg, male Bernese Mountain dog was referred for a non-traumatic acute right pelvic-limb lameness. At the age of 5 months, the dog underwent bilateral tibial plateau cranial hemiepiphysiodesis to treat a bilateral partial cranial cruciate ligament rupture and excessive tibial plateau angles. At clinical examination, a caudal tibial subluxation of the right stifle was detected. The right tibial plateau angle was 3 degree. Arthroscopy confirmed a complete caudal cruciate ligament rupture. The cranial cruciate ligament was partially torn. A diagnosis of caudal cruciate ligament rupture 8.5 years post juvenile tibial plateau hemiepiphysiodesis was made. A tibial plateau overcorrection might have contributed to caudal cruciate ligament rupture in this dog.
Prevalence and Risk Factors for Bilateral Meniscal Tears Identified during Treatment for Cranial Cruciate Ligament Disease Via Tibial Plateau Levelling Osteotomy in Dogs
Authors: Laube Rebecca L. , Kerstetter Kyle K.
Published: October 2020

Objective The aim of this study was to report the prevalence and risk factors of bilateral meniscal tears during a tibial plateau levelling osteotomy (TPLO).

Methods Data from 362 dogs that underwent staged or simultaneous TPLO between January 2006 and April 2019 were retrospectively collected. Variables such as breed, sex, weight change and intervals between surgeries were analysed with logistic regression. Preoperative tibial plateau angle, age, cranial cruciate ligament status and body weight were analysed with a generalized linear mixed model. All analyses were performed to assess the likelihood of bilateral meniscal tears versus unilateral tears and no tears. Correlation of meniscal tears between stifles was assessed with Cohen's kappa coefficient.

Results Prevalence of bilateral meniscal tears was 48.0% (95% confidence interval [CI]: 43.0–53.0%). There was moderate agreement of the presence of meniscal tears between stifles (Cohen's kappa coefficient = 0.41, 95% CI: 0.31–0.51).The odds for bilateral meniscal tears were higher for Rottweilers (odds ratio [OR:] 4.5 [95% CI 1.1–30.3], p = 0.033), older dogs (OR: 1.2 [95% CI: 1.1–1.4 per year], p < 0.0001), smaller dogs (OR: 0.98 [95% CI: 0.97–0.99 per 0.45-kg], p = 0.001), stifles with complete cranial cruciate ligament tears (OR: 21.1 [95% CI: 7.1–62.4], p < 0.0001).

Conclusion Contralateral meniscal tears, breed, older age, lower patient weight and complete cranial cruciate ligament tear were significant risk factors for bilateral meniscal tears. Surgeons can use these results to determine prognoses and propensities for meniscal tears in at-risk dogs.
Novel Coronavirus: What to Learn from a Microbiologist?
Authors: Chhina Deepinder K. , Chaudhary Jyoti
Published: October 2020

In December 2019, an outbreak of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) was declared in Wuhan, city of China. Later on, the World Health Organization declared COVID-19 as a pandemic on March 11, 2020. The clinical course of the disease ranges from asymptomatic cases to fatal severe respiratory illness. Various laboratory tests are available for the diagnosis of disease. The gold standard test is real-time PCR (polymerase chain reaction), whereas antigen testing can be used as a point-of-care test. Antibody detection by ELISA (enzyme-linked immunosorbent assay) can be used for the surveillance of the immune response.
Comparison of Hyoid Bone Position in Skeletal Class I Subjects with Varying Growth Patterns: A Cephalometric Study
Authors: Bhullar Mandeep Kaur , Gupta Nikita , Mittal Sanjay , Aggarwal Isha , Palkit Tanzin , Goyal Merry
Published: October 2020

Introduction Hyoid bone plays a significant role in physiological functions of craniofacial region, and its position adapts to changes of the head posture. The objective of this study was to evaluate the hyoid bone position among skeletal Class I subjects with various growth patterns.

Materials and Methods 90 subjects of north Indian origin, aged between 16 to 30 years, having skeletal class I relation were selected for the study. Subjects were then subdivided into three groups, that is, Group I (n = 30; normodivergent), Group II (n = 30; hypodivergent) and Group III (n = 30; hyperdivergent), based on their vertical growth pattern. Lateral cephalograms were traced and analyzed manually for evaluation of hyoid bone position.

Result  The sagittal position of the hyoid bone shows no significant difference with varying growth patterns. The vertical relation G-C3Chor distance showed significant difference in hypodivergent subjects. The axial inclination of the hyoid bone showed no significant difference between different growth patterns.

Conclusion The anteroposterior position of the hyoid bone does not change with different growth patterns in skeletal class I subjects. The G-C3Chor distance was found to be statistically significant when the three groups were compared.
Modeling interfacial mass transfer driven bubble growth in supersaturated solutions
Authors: Vachaparambil Kurian J. , Einarsrud Kristian Etienne
Published: October 2020

A commonly encountered phenomenon in chemical processes is bubble evolution driven by supersaturation. On the continuum scale, this essentially involves interfacial mass transfer resulting in the growth of bubbles and their subsequent detachment from a surface. Analytical approaches to study this phenomenon typically involve estimating the driving force for interfacial mass transfer based on Sherwood number (Sh) correlations and the bulk concentration of dissolved gas. This is often not practical since the bulk concentration is often unknown and Sh correlations are sometimes not available to provide an accurate description of the associated flow fields. With the use of interface-resolved simulations to model these processes, the local distribution of dissolved gas can be obtained by solving for the concentration field. The driving force for interfacial mass transfer can be computed based on Sh correlations (which can be adopted for specific flows and are typically used in “engineering” applications) or the universally applicable Fick’s first law. This paper compares the predictions of these approaches for the well-studied case of a two-dimensional bubble growing in an unbounded supersaturated solution for three different levels of supersaturation. The equivalent two-dimensional simulations are run in a previously developed volume of fluid framework on OpenFOAM® [K. J. Vachaparambil and K. E. Einarsrud, Appl. Math. Model. 81, 690–710 (2020)]. The results show that the choice of an appropriate Sh correlation can provide a reasonable estimate of bubble growth. In a more universal approach, which is relevant when the flow being simulated cannot be captured by a single Sh correlation (e.g., bubble growth/coalescence and detachment) or when existing Sh correlations are not applicable, Fick’s first law can be used to compute the driving force for bubble growth, provided that the concentration boundary layer can be resolved.
Ultrafast single-shot optical vector network analyzer based on coherent time-stretch
Authors: Li A. Lun , Xu B. Liang , Fu C. Sidong , Zhang D. Lei , Duan E. Yuhua , Li F. Yaoshuai , Yang G. Ningning , Yu H. Yu , Zhang I. Chi , Wong J. Kenneth K. Y. , Zhang K. Xinliang
Published: October 2020

Ever-increasing demands for a higher bandwidth of data in the optical communications augment the operating frequency of components and systems. To accelerate the development of these large-bandwidth technologies, there is a growing demand to characterize the frequency response of optical devices in real time. In this work, we report a method to significantly improve the measurement speed of an optical vector network analyzer (OVNA) with coherent time-stretch (CTS). Single-shot frequency spectrum measurements are enabled by time-stretch technology that maps the spectrum of an optical pulse to the time domain. Compared to single-ended detection, the implementation of coherent detection enables the acquiring of accurate phase information of the signal and also provides the digital processed cancellation of dispersion-induced impairments. By utilizing dispersive time-stretch and digital coherent detection techniques, we demonstrate an ultrafast and wide bandwidth OVNA. We successfully characterize its performance by measuring the frequency response of a micro-ring cavity and a silicon Mach–Zehnder interferometer with 0.07-nm spectral resolution and 0.156-rad phase accuracy over 10-nm bandwidth. Meanwhile, the dynamic responses of the magnitude and phase, and the drift of the resonance wavelength of the micro-ring modulator under thermal tuning, were fully recorded by the CTS-OVNA at a 20-MHz frame rate.
Structural basis for CDK7 activation by MAT1 and Cyclin H
Authors: Peissert Stefan , Schlosser Andreas , Kendel Rafaela , Kuper Jochen , Kisker Caroline
Published: October 2020

Significance

The fundamental processes of cell-cycle regulation and transcription are linked by the heterotrimeric CDK-activating kinase (CAK) complex. We solved the crystal structure of the active CAK complex and provide a molecular rationale for CAK activation, regulation, and substrate recognition. Our data thus highly advance our understanding of this essential factor which is also a proven target for cancer therapy.
Strongman, patronage and fake news
Authors: Ragragio Jefferson Lyndon D.
Published: October 2020

Human rights are essential pillars of democracies. But under populism, they are a proclaimed nemesis of political
leaders who claim to represent the common people. This article argues that the discourses of strongman, patronage and fake news
constitute three prominent right-wing populist ploys that erode human rights in Rodrigo Duterte’s Philippines. It interrogates the
communicative power of populism as a means of disfiguring free expression and press freedom. Drawing from human rights and media
reports and interviews, the pro-human rights current is reformatted by strongman pronouncement in the war on drugs, unity of
long-established blocs of power through patronage, and belligerent charge of fake news.
Anomalous tqγ Couplings and Radiative B Meson Decays*
Authors: Tan Ying , Yue Chong-Xing
Published: October 2020

Motivated by the recent ATLAS results in terms of the branching ratios Br(t → qγ), we consider the effects of the anomalous tqγ couplings on the radiative B meson decays

B
¯

→

X
D

γ

and B → Vγ with V being light vector mesons ρ, ω, ϕ and K
*. Comparing with the corresponding experimental measured data, we obtain the constraints on anomalous tqγ couplings.
Effect of B-Site Ordering on the Magnetic Order in Multifunctional La2NiMnO6 Double Perovskite*
Authors: Yang Dexin , Jiang Rui , Zhang Yaohua , Zhang Hui , Lei Senlin , Yang Tao , Hu Xiaoshi , Huang Shuai , Ge Jingyuan , Su Kunpeng , Wang Haiou , Huo Dexuan
Published: October 2020

To obtain various Ni/Mn orderings, we use a low-temperature synthesized method to modulate the Ni/Mn ordering of the ferromagnetic-ferroelastic La2NiMnO6 compound, and the Ni/Mn ordering is estimated by the low-temperature saturation magnetism. The microstructures, crystal structures and magnetic properties are investigated, and the Landau theory are used to describe the form and magnitude of the coupling effects between Ni/Mn ordering and magnetic order parameters. It is predicted that the Ni/Mn ordering would be a strong coupling effect with the Curie transition temperatures if the La2NiMnO6 sample stoichiometry is close.
Diffraction-Limited Imaging with a Graphene Metalens*
Authors: Li Xueyan , Lin Han , Zhao Yuejin , Jia Baohua
Published: October 2020

Planar graphene metalens has demonstrated advantages of ultrathin thickness (200 nm), high focusing resolution (343 nm) and efficiency (>32%) and robust mechanical strength and flexibility. However, diffraction-limited imaging with such a graphene metalens has not been realized, which holds the key to designing practical integrated imaging systems. In this work, the imaging rule for graphene metalenses is first derived and theoretically verified by using the Rayleigh-Sommerfeld diffraction theory to simulate the imaging performance of the 200 nm ultrathin graphene metalens. The imaging rule is applicable to graphene metalenses in different immersion media, including water or oil. Based on the theoretical prediction, high-resolution imaging using the graphene metalens with diffraction-limited resolution (500 nm) is demonstrated for the first time. This work opens the possibility for graphene metalenses to be applied in particle tracking, microfluidic chips and biomedical devices.
Magnetic Phase Diagram of Cu4–xZnx(OH)6FBr Studied by Neutron-Diffraction and μSR Techniques*
Authors: Wei Yuan , Ma Xiaoyan , Feng Zili , Adroja Devashibhai , Hillier Adrian , Biswas Pabitra , Senyshyn Anatoliy , Hoser Andreas , Mei Jia-Wei , Meng Zi Yang , Luo Huiqian , Shi Youguo , Li Shiliang
Published: October 2020

We systematically investigate the magnetic properties of Cu4 – x
Zn
x
(OH)6FBr using the neutron diffraction and muon spin rotation and relaxation (μSR) techniques. Neutron-diffraction measurements suggest that the long-range magnetic order and the orthorhombic nuclear structure in the x = 0 sample can persist up to x = 0.23 and 0.43, respectively. The temperature dependence of the zero-field μSR spectra provides two characteristic temperatures, T

A
0
and Tλ
, which are associated with the initial drop close to zero time and the long-time exponential decay of the muon relaxation, respectively. Comparison between T

A
0
and T
M from previously reported magnetic-susceptibility measurements suggest that the former comes from the short-range interlayer-spin clusters that persist up to x = 0.82. On the other hand, the doping level where Tλ
becomes zero is about 0.66, which is much higher than threshold of the long-range order, i.e., ∼0.4. Our results suggest that the change in the nuclear structure may alter the spin dynamics of the kagome layers and a gapped quantum-spin-liquid state may exist above x = 0.66 with the perfect kagome planes.
Quantum Oscillations and Electronic Structure in the Large-Chern-Number Topological Chiral Semimetal PtGa*
Authors: Xu Sheng , Zhou Liqin , Wang Xiao-Yan , Wang Huan , Lin Jun-Fa , Zeng Xiang-Yu , Cheng Peng , Weng Hongming , Xia Tian-Long
Published: October 2020

We report the magnetoresistance (MR), de Haas-van Alphen (dHvA) oscillations and the electronic structures of single-crystal PtGa. The large unsaturated MR is observed with the magnetic field B ∥ [111]. Evident dHvA oscillations with the B ∥ [001] configuration are observed, from which twelve fundamental frequencies are extracted and the spin-orbit coupling (SOC) induced band splitting is revealed. The light cyclotron effective masses are extracted from the fitting by the thermal damping term of the Lifshitz–Kosevich formula. Combining with the calculated frequencies from the first-principles calculations, the dHvA frequencies F
1/F
3 and F
11/F
12 are confirmed to originate from the electron pockets at Γ and R, respectively. The first-principles calculations also reveal the existence of spin-3/2 Rarita–Schwinger–Weyl fermions and time-reversal doubling of the spin-1 excitation at Γ and R with large Chern numbers of ± 4 when SOC is included.
Scrolled Production of Large-Scale Continuous Graphene on Copper Foils*
Authors: Zhang Zhibin , Qi Jiajie , Zhao Mengze , Shang Nianze , Cheng Yang , Qiao Ruixi , Zhang Zhihong , Ding Mingchao , Li Xingguang , Liu Kehai , Xu Xiaozhi , Liu Kaihui , Liu Can , Wu Muhong
Published: October 2020

We report an efficient and economical way for mass production of large-scale graphene films with high quality and uniformity. By using the designed scrolled copper-graphite structure, a continuous graphene film with typical area of 200 × 39 cm2 could be obtained in 15 min, and the production rate of the graphene film and space utilization rate of the CVD reactor can reach 520 cm2⋅min−1 and 0.38 cm−1⋅min−1, respectively. Our method provides a guidance for the industrial production of graphene films, and may also accelerate its large-scale applications.
Effects of Eu2+ on the luminescence and afterglow that arise from defects in β-SiAlON:Eu2+
Authors: Suda Yoriko , Kamigaki Yoshiaki , Miyagawa Hayato , Takeda Takashi , Takahashi Kohsei , Hirosaki Naoto
Published: October 2020

Si6−z
Al
z
O
z
N8−z
(β-SiAlON):Eu2+ is known as a high brightness green phosphor. When β-SiAlON:Eu2+ is excited with UV light (approximately 265 nm), a curved decay afterglow is observed as a result of the trap levels created by the defects in the host crystal. However, the defect signals are hardly detected by electron spin resonance (ESR) and thermoluminescence (TL), which are common defect detection methods. Non-doped (Eu = 0) β-SiAlON emits blue light from a nitrogen defect, and the defect can be detected by time-resolved fluorescence (TR-F) measurement at 15 K. Similarly, upon measuring TR-F at 15 K for Eu-doped β-SiAlON, a blue emission (460 nm) is detected in addition to the green emission of Eu2+ (530 nm). The green emission has an afterglow of several milliseconds that decays with the same decay curve as the blue emission of the defect, and its time constant is 5–6 ms. This blue emission is quenched by the Eu concentration and temperature. The Si dangling bond signal intensity, observed by ESR, and the glow intensity, observed by TL, also decrease with the increment of the Eu concentration. It is difficult to detect the defect as an electron trap owing to the interaction between Eu2+ and the nitrogen defect. However, the afterglow arising from the electrons trapped at the defect level does not decrease with the Eu concentration. The blue emission was quenched at room temperature but the afterglow was not reduced, which also affected the light emission above room temperature. Therefore, it is possible to detect nitrogen defects optically by TR-F at low temperature, as well as the Eu2+ afterglow of several milliseconds.
Signal conditioning using logarithmic amplifier for biomedical applications of electrical impedance tomography
Authors: Saxena M , Gharpure D C , Wagh V G
Published: October 2020

Objective: The aim of this study was to explore the use of a logarithmic amplifier to improve the spatial resolution (RES) of a low-cost electrical impedance tomography (EIT) system. In an EIT system, the measured signal has a large dynamic range from µV to mV, which requires high-RES (analog to digital conversion) cards. The logarithmic amplifier reduces the dynamic range by expanding lower values and compressing higher values, thereby improving the sensitivity and at the same time preventing the signal from saturation. In addition, a low-RES analog to digital conversion (ADC) cards can be used, making the system cost effective. This work evaluates the performance of a logarithmic amplifier and a linear amplifier used for signal conditioning in a low-cost EIT system. Approach: Two EIT systems based on a linear amplifier and logarithmic amplifier were designed. Phantom experiments were carried out with very small amounts of current injection. The signal-to-noise ratio (SNR), image quality, minimum detectable size and minimum detectable conductivity change were obtained. Main results: The logarithmic amplifier-based EIT system increased the average SNR by 4 dB. It also showed improvement in the RES and contrast-to-noise ratio of the images. The minimum size detectable by the logarithmic amplifier-based system was of radius 0.25 cm in a tank of radius 11 cm and the minimum change in conductivity detectable was 11%. Significance: Logarithmic amplifier-based signal conditioning is a promising technique for improving the spatial RES of a low-cost EIT system that has a low-RES ADC.
Electrical performances degradations and physics based mechanisms under negative bias temperature instability stress for p-GaN gate high electron mobility transistors
Authors: Zhang Chi , Liu Siyang , Li Sheng , Li Ningbo , Tao Xinyi , Hou Bo , Zhou Bin , Wei Jiaxing , Chen Yiqiang , Sun Weifeng
Published: October 2020

In this paper, an in-depth evaluation of the negative bias temperature instability (NBTI) in p-GaN gate high electron mobility transistors with Schottky-type gate contact has been reported in detail. The measured results reveal that the threshold voltage (V
th) positively shifts by 0.35 V and the on-state drain-source resistance (R
dson) increases by 24.2 mΩ within 1 h at room temperature, even under the minimum allowed operating gate-voltage condition (V
gs = −10 V) in the datasheet of the commercial device. With the help of energy band theory and experimental analyses, donor-type traps are demonstrated to dominate the degradation by reducing the positive charges in the p-GaN cap. Moreover, further quantitative analysis has been performed by the conductance–frequency measurements method. Considering the risk of degradation induced by NBTI, it turns necessary for the system designers to choose a more suitable negative bias operating condition so as to extend the robustness of the entire power system.
Mechanical metamaterials with programmable compression-twist coupling
Authors: Goswami Debkalpa , Zhang Yunlan , Liu Shuai , Abdalla Omar A , Zavattieri Pablo D , Martinez Ramses V
Published: October 2020

The rational design of mechanical metamaterials has the potential to grant them with properties unattainable by bulk materials. This paper describes twisting mechanical metamaterials (TMMs), a new class of programmable matter whose rationally designed architecture endows them with compression-twist coupling, a property absent in conventional materials. Upon compression, the cellular architecture of TMMs efficiently transforms longitudinal strain into unidirectional or bidirectional twisting—free from mechanical frustrations and independent of the flexible material chosen to fabricate the TMM. TMMs can be rapidly designed using an automated generative algorithm, which enables the tailoring of their twisting properties (up to 3.24° twist per % strain) and Poisson’s ratio (−0.6 to +1.22) using only two design parameters. The scalable architecture of TMMs does not suffer from size effects which impair their twist per unit strain. Bidirectional TMMs autonomously switch their direction of rotation during uniform displacement-controlled compressive loading, conferring them with non-interchangeable compression-twist coupling. The capability of TMMs to controllably convert translation to rotation blurs the boundary between materials and machines, expanding the range of mechanical properties currently accessible to 3D printed materials and paving the way toward the creation of future programmable matter.
Protein–protein docking with interface residue restraints*
Authors: Li Hao , Huang Sheng-You
Published: October 2020

The prediction of protein–protein complex structures is crucial for fundamental understanding of celluar processes and drug design. Despite significant progresses in the field, the accuracy of ab initio docking without using any experimental restraints remains relatively low. With the rapid advancement of structural biology, more and more information about binding can be derived from experimental data such as NMR experiments or chemical cross-linking. In addition, information about the residue contacts between proteins may also be derived from their sequences by using evolutionary analysis or deep learning. Here, we propose an efficient approach to incorporate interface residue restraints into protein–protein docking, which is named as HDOCKsite. Extensive evaluations on the protein–protein docking benchmark 4.0 showed that HDOCKsite significantly improved the docking performance and obtained a much higher success rate in binding mode predictions than original ab initio docking.
Evidence of potential change in nonsequential double ionization*
Authors: Jia Changchun , Zhang Pu , Wen Hua , Chen Zhangjin
Published: October 2020

Recently, the quantitative rescattering model (QRS) for nonsequential double ionization (NSDI) is modified by taking into account the potential change (PC) due to the presence of electric field at the time of recollision. Using the improved QRS model, we simulate the longitudinal momentum distributions of doubly charged ions He2+ by projecting the correlated two-electron momentum distributions for NSDI of He onto the main diagonal. The obtained results are compared directly with the experimental data at different intensities. It is found that when the PC is considered, the width of momentum distributions reduces and the agreement between theory and experiment is improved.
Growth of high quality InSb thin films on GaAs substrates by molecular beam epitaxy method with AlInSb/GaSb as compound buffer layers*
Authors: Li Yong , Li Xiao-Ming , Hao Rui-Ting , Guo Jie , Zhuang Yu , Cui Su-Ning , Wei Guo-Shuai , Ma Xiao-Le , Wang Guo-Wei , Xu Ying-Qiang , Niu Zhi-Chuan , Wang Yao
Published: October 2020

A series of InSb thin films were grown on GaAs substrates by molecular beam epitaxy (MBE). GaSb/AlInSb is used as a compound buffer layer to release the strain caused by the lattice mismatch between the substrate and the epitaxial layer, so as to reduce the system defects. At the same time, the influence of different interface structures of AlInSb on the surface morphology of buffer layer is explored. The propagation mechanism of defects with the growth of buffer layer is compared and analyzed. The relationship between the quality of InSb thin films and the structure of buffer layer is summarized. Finally, the growth of high quality InSb thin films is realized.
Dynamic measurement of beam divergence angle of different fields of view of scanning lidar*
Authors: Li Qing-Yan , Yan Shi-Yu , Zhang Bin , Wang Chun-Hui
Published: October 2020

The laser beam divergence angle is one of the important parameters to evaluate the quality of the laser beam. It can not only accurately indicate the nature of the beam divergence when the laser beam is transmitted over a long distance, but also objectively evaluate the performance of the laser system. At present, lidar has received a lot of attention as a core component of environment awareness technology. Micro-electromechanical system (MEMS) micromirror has become the first choice for three-dimensional imaging lidar because of its small size and fast scanning speed. However, due to the small size of the MEMS micromirror, the lidar scanning system has a small field of view (FOV). In order to achieve a wide range of scanning imaging, collimating optical system and wide-angle optical system are generally added to the system. However, due to the inherent properties of the optical lens, it is impossible to perfect the imaging, so the effects of collimating and expanding the beam will be different at different angles. This article aims to propose a measurement system that dynamically measures the divergence angles of MEMS scanning lidar beams in different fields of view to objectively evaluate the performances of scanning lidar systems.
Thin accretion disk around a four-dimensional Einstein-Gauss-Bonnet black hole *
Authors: Liu Cheng , Zhu Tao , Wu Qiang
Published: October 2020

Recently, a novel four-dimensional Einstein-Gauss-Bonnet (4EGB) theory of gravity was proposed by Glavan and Lin [D. Glavan and C. Lin, Phys. Rev. Lett. 124, 081301 (2020)], which includes a regularized Gauss-Bonnet term using the re-scalaring of the Gauss-Bonnet coupling constant

in the limit

. This theory has also been reformulated to a specific class of the Horndeski theory with an additional scalar degree of freedom and to a spatial covariant version with a Lagrangian multiplier, which can eliminate the scalar mode. Here, we study the physical properties of the electromagnetic radiation emitted from a thin accretion disk around a static spherically symmetric black hole in 4EGB gravity. For this purpose, we assume the disk is in a steady-state and in hydrodynamic and thermodynamic equilibrium, so that the emitted electromagnetic radiation is a black body spectrum. We study in detail the effects of the Gauss-Bonnet coupling constant

in 4EGB gravity on the energy flux, temperature distribution, and electromagnetic spectrum of the disk. With an increase in the parameter

, the energy flux, temperature distribution, and electromagnetic spectrum of the accretion disk all increase. We also show that the accretion efficiency increases with the growth of the parameter

. Our results indicate that the thin accretion disk around a static spherically symmetric black hole in 4EGB gravity is hotter, more luminous, and more efficient than that around a Schwarzschild black hole with the same mass for positive

, while it is cooler, less luminous, and less efficient for negative

.
Carbon Capture and Storage Using Renewable Energy Sources: A Review
Authors: Ragul hari S , Prem Balaji C , Karunamurthy K
Published: October 2020

The world is undergoing a population explosion; urbanization has also taken giant leaps with higher standards of people. It is noted that the supply and the demand for energy have not been in correlation with one another, as around. When the supply of energy is scaled up, there will large amounts of emissions released from the power plants. Therefore, it is important to focus on capturing and storage of harmful greenhouse gas emissions, using renewable energy resources, so that emission mitigation can be made in an efficient and economically feasible way. The pragmatic analysis of solar-assisted post-combustion carbon capture (SPCC) has been reviewed upon, where the energy compensation of a coal-fired plant due to regeneration of absorbent has been scrutinized. It is also been compared with the integration of geothermal energy (GTCC) for carbon capture. In the adsorption process, various techno-economic analysis of Carbon Capture and Storage (CCS) integrating solar-assisted temperature swing adsorption has been reported along with the effect of absorbent material in pressure-temperature swing adsorption for CO2 capture. Assessment of solar-assisted CCS are also been accomplished by adopting pliable thinking on the energy system. Finally, the integration with solar thermal power plant using novel Sodium Carbonate as a solvent is discussed. Thus, several parts of the CCS system have been construed with renewable energy towards the goal of zero-emission power generation, which seems highly impossible, can be harnessed by 2050
Impact analysis on change in climatic conditions due to the development of highway roads and other infrastructures at Coimbatore - an evidence
Authors: Thenmozhi G , Cherian Mary , Nirmala M
Published: October 2020

Global warming, a major threat is mainly due to the increase in population. This leads to an increase in infrastructural facilities, and vehicles. The major reasons for the increase in temperature may be due to pollutant gases from Industries and Vehicles, other Infrastructural development, etc. Because of this, trees are being cut down which increases the temperature thereby reducing the rainfall. Also, rainfall decreases because of the destruction of trees leading to decreased groundwater levels. The proposed study primarily focuses on the change in climatic conditions such as temperature, relative humidity, and rainfall due to the development of infrastructures such as highway roads, bridges, etc. The above indicators were being addressed by many authors earlier, but there exists a gap in addressing the growth of infrastructure on the above-said factors. This proposed study presents a chance to address the gap that exists in the earlier literature based on the indicators specified above due to the infrastructural developments. Hence an Impact analysis is required to address the issues of infrastructure development especially for Coimbatore – Pollachi highway road. The detailed meteorological data of the past five years are taken for analysis and suggestions for Smart City projects, Policymaking decisions are addressed.
A Design Analysis of Suspension Energy Regenerative System Using Dynamo Damping
Authors: Mujumdar Tapan , Sneh Asim , Gupta Manshu , Venugopal T.
Published: October 2020

The ordinary vehicle suspension system scatters the mechanical vibration vitality as a considerable amount of waste heat. In recent times the regenerative suspension systems have pulled in much consideration for the augmentation of vibration attenuating performance as well as the reduction of energy dissipation or harvesting the same. The main objective is to fabricate a prototype of Suspension Energy Regeneration System (S.E.R.S.) at a convenient cost for the automobile industry, further conduct the experiments, and analyse the power output. Also, to raise the fuel efficiency of the engine by decreasing the consumption of electrical energy produced by the I.C. engine by harvesting the same energy from S.E.R.S. Thus, reducing the fuel energy wastage and promote sustainable development. The main focus is to evaluate the possibility of using dynamo as a damping module in the Suspension system. The performance analysis was done to observe the differences between the operations of the conventional suspension system and S.E.R.S. After carrying out the necessary study, the simplified design of S.E.R.S. was made and fabricated which was cost-efficient as well as had enough power regeneration to support auxiliary electronic system in vehicles like audio system, headlights, etc.