bluuebunny/crossref_metadata_2025 huggingface dataset:
Der Einfluss der Mikrobiota auf den Blutdruck
Authors: Wilck Nicola
Published: November 2020

Den Einfluss der Mikrobiota auf Gesundheit und Krankheit besser zu verstehen, ist eine große Herausforderung für die Forschung. Darmbakterien können die Blutdruckregulation beeinflussen und die Entstehung von Bluthochdruck begünstigen. Dabei ist zum einen eine aberrante Zusammensetzung der Bakterien relevant, zum anderen sind veränderte Funktionen der bakteriellen Gemeinschaft ausschlaggebend. Eine Schlüsselfunktion nehmen von Bakterien produzierte Metabolite ein, die vom Wirt resorbiert werden und Einfluss auf Gefäßfunktion, immunologische Prozesse und Endorganschäden nehmen können. Da Bakterien diese Metabolite aus N 11907967 ährstoffen herstellen, wird einmal mehr die zentrale Rolle der Ernährung klar. Ballaststoff- und Salzgehalt der Nahrung sollen in diesem Artikel beispielhaft aufzeigen, wie Nährstoffe über bakteriell vermittelte Mechanismen den Blutdruck beeinflussen können. Zukünftig könnte die gezielte Nutzung der Mikrobiota die Therapie von Patienten mit Bluthochdruck verbessern.
Nachhaltige Infrastruktur für die Versorgungsforschung: Der Aufbau einer regionalen, krankenkassenübergreifenden GKV-Routinedatenbank
Authors: Scholten Nadine , Ihle Peter , Pfaff Holger ,   für das CoRe-Net Konsortium,   und den kooperierenden Krankenkassen (AOK Rheinland/Hamburg, BARMER, DAK-Gesundheit, pronova BKK)
Published: November 2020

Ziel Die wissenschaftliche Nutzung von GKV Routinedaten hat v. a. auch im Bereich der Versorgungsforschung immer mehr zugenommen. Dadurch ergeben sich auch neue Fragen in Bezug auf den Aufbau von krankenkassenübergreifenden Datenbanken, die eine längerfristige Speicherung dieser Daten für längsschnittliche Analysen möglich machen sollen. Anhand der Erfahrungen beim Aufbau der CoRe-Net Datenbank soll gezeigt werden, dass es möglich ist eine derartige Forschungsinfrastruktur zu installieren und langfristig nutzbar zu machen.

Methodik/Ergebnisse Auf Basis der aktuellen geltenden Rahmenbedingungen (u. a. ergänzte Präzisierung des § 75 SGB X) und unter Berücksichtigung strenger datenschutzrechtlicher Kriterien ist es möglich eine krankenkassenübergreifende Datenbank aufzubauen: In CoRe-Net wurde dazu eine Pseudonymisierungs- und eine Vertrauensstelle implementiert. Gleichzeitig wird eine mehrfache Pseudonymisierung unter Nutzung eines Einweg-Hashverfahrens durchgeführt. Datenauswertungen sind nur nach Zustimmung durch die beteiligten Kassen und bei Vorliegen eines gültigen Ethikvotums möglich.

Schlussfolgerung Die Anpassung des § 75 SGB X in 2018 schaffte einen rechtlichen Rahmen, GKV-Routinedaten im Rahmen eines Forschungsvorhabens auch für künftige Fragestellungen im Rahmen eines definierten Forschungsbereichs zu erheben und zu speichern.
Donorsite defect of medial femoral condyle corticoperiostal flap in the treatment of lower limb infected nonunions
Authors: Guzzini Matteo , Arioli Leopoldo , Rugiero Clelia , Rossini Marco , Argento Giuseppe , Ferretti Andrea
Published: November 2020

Backgrounds Chronic osteomyelitis is a major challenge in orthopaedic surgery; it is the result of open fracture, periprosthetic infection and septic arthritis. Osteomyelitis leads to fracture nonunion. The treatment of bone infection and infected nonunion consists primarily of the complete removal of infected and avascular bone and soft tissue from the surgical site, followed by local and systemic pathogen-specific antibiotic therapy and temporary stabilisation, but may lead to massive skeletal and soft tissue defects. The use of free or pedicled vascularised bone transfers and callus distraction techniques (bone transport) has been recommended for large bone defects. The aim of this study is to evaluate the results of patients affected by infected non-unions of the lower limbs, treated with a corticoperiosteal flap from the medial femoral condyle and to investigate the donor site morbidity of this flap.

Materials and methods The patients were 11 males (average age of 45.6 years), who presented a nonunion of the tibial diaphysis in 7 cases and non-union of femoral diaphysis in 4 cases, treated with free or pedicled corticoperiosteal flap. In all patients, surgical debridement was performed before the flap of infected bone and soft tissues that would not contribute to wound healing. Clinical and radiographic evaluations of the recipient site were performed. Preoperative and postoperative X-ray and MRI scans after the 3-year follow-up of the donor site were performed, in order to observe possible bone restoration and any complications.

Results The patients reported complete clinical and radiographic bone healing in 90.9 % of cases. As regards donor site, there were no differences between the medial femoral donor condyle compared to the contralateral site, due to complete regeneration of donor site bone. MRI investigation showed complete restoration of the donor site with vascularised bone in all patients.

Conclusions Our results suggest that the use of bone flaps for the treatment of infected non-unions is an effective procedure, that must be performed after accurate debridement of the non-union site. The corticoperiosteal flap seems to have few morbidities on the donor site and a high percentage of successful bone healing.
Extended Half-Life Factor VIII/Factor IX Products: Assay Discrepancies and Implications for Hemophilia Management
Authors: Müller Jens , Goldmann Georg , Marquardt Natascha , Pötzsch Bernd , Oldenburg Johannes
Published: November 2020

Due to structural differences between extended half-life (EHL) factor VIII (FVIII) or FIX products and equivalent plasma wild-type molecules used for assay calibration, reagent-dependent discrepancies during monitoring of FVIII- and FIX-replacement therapies with EHL products have been described. To assess the performance of available one-stage clotting and chromogenic substrate assays on the Siemens Atellica COAG 360 analyzer, an in vitro study using spiked plasma samples was performed. The described results confirm previously described findings and allowed allocation of each EHL product to an appropriate assay. In addition, corresponding EHL product–specific analytes were defined within the order entry system of the University Hospital Bonn. The requirement of product-specific FVIII and FIX assays complicates patient monitoring and demonstrates the need for both continuous education and communication between treating physicians and the coagulation laboratory.
Posteriore Sakkulation des Uterus im zweiten Trimenon – Diagnostik, erfolgreiche Therapie und Literatur
Authors: Hüner Beate , Handke-Vesely Annette , Janni Wolfgang , Reister Frank
Published: November 2020

Eine seltene Komplikation in der Geburtshilfe ist die posteriore Sakkulation des Uterus. Bleibt die Aufrichtung des schwangeren retroflektierten Uterus aus, persistiert der Fundus in der hinteren Kreuzbeinhöhle. Durch die zunehmende Größe verändert sich die gewohnte Anatomie und es kann bei Unkenntnis darüber zu einer hohen Morbidität für die Mutter kommen. Frühzeitige Aufrichtungsversuche können eine komplikationslose Prolongation der Schwangerschaft ermöglichen. In unserem Fall berichten wir von einer Erstgravida mit Erstdiagnose einer posterioren Sakkulation des Uterus in der 21. Schwangerschaftswoche. Nach Bestätigung der Diagnose mittels MRT gelang die Aufrichtung des Uterus durch vaginal digitales Anheben des Uterus sowie zeitgleicher rektoskopischer CO2-Füllung. Im weiteren Verlauf kam es zur komplikationslosen Spontangeburt nach Blasensprung in der 35. Schwangerschaftswoche.
The Effect of Maternal Pulmonary Function Test Parameters on Umbilical Cord Blood Gas and the Duration of Labor
Authors: Çaltekin Melike Demir , Onat Taylan , Kırmızı Demet Aydogan , Baser Emre , İntepe Yavuz Selim , Kara Mustafa , Yalvac Ethem Serdar
Published: November 2020

Objective To evaluate the relationship between the maternal pulmonary function test (PFT) and the Apgar score of the newborn, umbilical cord blood (UCB) gas values and the duration of delivery.

Material and Methods The present study included 41 volunteer nulliparous pregnant women who presented to our obstetrics clinic and PFTs were performed by using spirometry.

Results A significant positive correlation was observed between 5th-minute Apgar scores and maternal FEV1 (forced expiratory volume in the first second) (lt), FEV1%, FVC (lt), FVC% (r=0.509, p=0.003; r=0.47, p=0.007; r=0.434, p=0.013; r=0.417, p=0.017; respectively). A significant positive correlation was observed between UCB pH value and maternal FEV1 (lt), FVC (lt) (r=0.515, p=0.003; r=0.351, p=0.049; respectively).

Conclusion Our results showed that FEV1 and FVC values, which indicate maternal respiratory functions, may affect Apgar scores of the newborn and UCB gas values.
Sonoelastography to Assess Muscular Stiffness Among Older Adults and its Use for the Diagnosis of Sarcopenia: A Systematic Review
Authors: Janczyk Ewa Magdalena , Champigny Noémie , Michel Emeline , Raffaelli Charles , Annweiler Cédric , Zory Raphael , Guérin Olivier , Sacco Guillaume
Published: November 2020

Changes in muscle stiffness have been reported with sarcopenia. Sonoelastography is an accessible and non-radiating imaging technique allowing quantification of elastic properties of tissue. We performed a systematic review of the literature to investigate whether sonoelastography can be a reliable method to assess sarcopenia in older patients. We searched Medline, Google Scholar, Scopus, SpringerLink and Science direct from January 1, 1990 to April 1, 2020. Three independent review authors assessed trial eligibility, extracted the data, and assessed risk of bias. We intended to learn which types of elastography have been tested, if such measures are repeatable, and if they have been compared to the currently accepted diagnostic method. Ten studies met the inclusion criteria. Most followed a cross-sectional design with young and older adult subgroups. The gastrocnemius, rectus femoris, and vastus intermedius appeared most frequently. Nine of the included studies used shear wave elastography and one-strain elastography. The passive elastic constant was significantly greater in sarcopenic versus healthy subjects after passive stretching (124.98 ± 60.82 vs. 46.35 ± 15.85, P = 0.004). However, even in non-sarcopenic patients, the age of the patient was responsible for about 45.5 % of the variance in SWV. Among ten included articles, four reported higher stiffness in the muscles of older adults, two reported lower stiffness, and four found no significant difference. Due to the substantial heterogenicity of actual data, we could not make any conclusions about the potential usefulness of elastography to assess sarcopenia. Further studies are needed, including a larger sample of older patients and using a standardized and reproducible protocol.
Application of Azide-Tetrazole Tautomerism and Arylsulfanyl Group Dance in the Synthesis of Thiosubstituted Tetrazoloquinazolines
Authors: Novosjolova Irina , Turks Māris , Jeminejs Andris , Goliškina Svetlana M. , Stepanovs Dmitrijs , Bizdēna Ērika
Published: November 2020

Nucleophilic aromatic substitution reaction between 4-aryl­thio-2-chloroquinazolines and NaN3 takes place with an unusual sulfanyl group dance and leads to the formation of 5-(arylthio)tetrazolo[1,5-c]-quinazolines, which do not form the azide tautomer and do not undergo CuAAC reactions with alkynes. On the other hand, 5-azidotetrazolo[1,5-a]quinazoline (formally described as 2,4-diazidoquinazoline) undergoes regioselective nucleophilic aromatic substitution with thiols at C5 and forms 5-(alkyl/arylthio)tetrazolo[1,5-a]quinazolines, the structure of which has been proved by X-ray crystallography. The latter exist in tautomeric equilibrium with their 2-azidoquinazoline form, which provides possibility for copper-catalyzed azide–alkyne 1,3-dipolar cyclo­addition reaction, leading to the 4-alkyl/arylthio-2-(1H-1,2,3-triazol-1-yl)quinazolines.
Adapting Clinical Systems to Enable Adolescents' Genomic Choices
Authors: Prows Cynthia A. , Marsolo Keith , Myers Melanie F. , Nix Jeremy , Hall Eric S.
Published: November 2020

Background We offered adolescents personalized choices about the type of genetic results they wanted to learn during a research study and created a workflow to filter and transfer the results to the electronic health record (EHR).

Methods We describe adaptations needed to ensure that adolescents' results documented in the EHR and returned to adolescent/parent dyads matched their choices. A web application enabled manual modification of the underlying laboratory report data based on adolescents' choices. The final PDF format of the laboratory reports was not viewable through the EHR patient portal, so an EHR form was created to support the manual entry of discrete results that could be viewed in the portal.

Results Enabling adolescents' choices about genetic results was a labor-intensive process. More than 350 hours was required for development of the application and EHR form, as well as over 50 hours of a study professional's time to enter choices into the application and EHR. Adolescents and their parents who learned genetic results through the patient portal indicated that they were satisfied with the method of return and would make their choices again if given the option.

Conclusion Although future EHR upgrades are expected to enable patient portal access to PDFs, additional improvements are needed to allow the results to be partitioned and filtered based on patient preferences. Furthermore, separating these results into more discrete components will allow them to be stored separately in the EHR, supporting the use of these data in clinical decision support or artificial intelligence applications.
Risk Factors for Central Venous Access Device-Related Thrombosis in Hospitalized Children: A Systematic Review and Meta-Analysis
Authors: Tian Lingyun , Li Wan , Su Yanan , Gao Huimin , Yang Qiuhong , Lin Pan , Wang Liqian , Zeng Jiaqi , Li Yinglan
Published: November 2020

Objective To identify the potential associations of patient-, treatment-, and central venous access device (CVAD)-related factors with the CVAD-related thrombosis (CRT) risk in hospitalized children.

Methods A systematic search of PubMed, EMBASE, Web of Science, the Cochrane Library, China National Knowledge Infrastructure, Wanfang, and VIP database was conducted. RevMan 5.3 and Stata 12.0 statistical software were employed for data analysis.

Results In terms of patient-related factors, the patient history of thrombosis (odds ratio [OR] = 3.88, 95% confidence interval [CI]: 2.57–5.85), gastrointestinal/liver disease (OR = 1.85, 95% CI: 0.99–3.46), hematologic disease (OR = 1.45, 95% CI: 1.06–1.99), and cancer (OR = 1.58, 95% CI: 1.01–2.48) were correlated with an increased risk of CRT. In terms of treatment-related factors, parenteral nutrition (PN)/total PN (OR = 1.70, 95% CI: 1.21–2.39), hemodialysis (OR = 2.17, 95% CI: 1.34–3.51), extracorporeal membrane oxygenation (OR = 1.51, 95% CI: 1.31–1.71), and cardiac catheterization (OR = 3.92, 95% CI: 1.06–14.44) were associated with an increased CRT risk, while antibiotics (OR = 0.46, 95% CI: 0.32–0.68) was associated with a reduced CRT risk. In terms of the CVAD-related factors, CRT risk was more significantly increased by peripherally inserted central catheter than tunneled lines (OR = 1.81, 95% CI: 1.15–2.85) or totally implantable venous access port (OR = 2.81, 95% CI: 1.41–5.60). And subclavian vein catheterization significantly contributed to a lower CRT risk than femoral vein catheterization (OR = 0.36, 95% CI: 0.14–0.88). Besides, multiple catheter lines (OR = 4.06, 95% CI: 3.01–5.47), multiple catheter lumens (OR = 3.71, 95% CI: 1.99–6.92), central line-associated bloodstream infection (OR = 2.66, 95% CI: 1.15–6.16), and catheter malfunction (OR = 1.65, 95% CI: 1.07–2.54) were associated with an increased CRT risk.

Conclusion The exact identification of the effect of risk factors can boost the development of risk assessment tools with stratifying risks.
Anticoagulation in COVID-19: Effect of Enoxaparin, Heparin, and Apixaban on Mortality
Authors: Billett Henny H. , Reyes-Gil Morayma , Szymanski James , Ikemura Kenji , Stahl Lindsay R. , Lo Yungtai , Rahman Shafia , Gonzalez-Lugo Jesus D. , Kushnir Margarita , Barouqa Mohammad , Golestaneh Ladan , Bellin Eran
Published: November 2020

Background Mortality in coronavirus disease of 2019 (COVID-19) is associated with increases in prothrombotic parameters, particularly D-dimer levels. Anticoagulation has been proposed as therapy to decrease mortality, often adjusted for illness severity.

Objective We wanted to investigate whether anticoagulation improves survival in COVID-19 and if this improvement in survival is associated with disease severity.

Methods This is a cohort study simulating an intention-to-treat clinical trial, by analyzing the effect on mortality of anticoagulation therapy chosen in the first 48 hours of hospitalization. We analyzed 3,625 COVID-19+ inpatients, controlling for age, gender, glomerular filtration rate, oxygen saturation, ventilation requirement, intensive care unit admission, and time period, all determined during the first 48 hours.

Results Adjusted logistic regression analyses demonstrated a significant decrease in mortality with prophylactic use of apixaban (odds ratio [OR] 0.46, p = 0.001) and enoxaparin (OR = 0.49, p = 0.001). Therapeutic apixaban was also associated with decreased mortality (OR 0.57, p = 0.006) but was not more beneficial than prophylactic use when analyzed over the entire cohort or within D-dimer stratified categories. Higher D-dimer levels were associated with increased mortality (p < 0.0001). When adjusted for these same comorbidities within D-dimer strata, patients with D-dimer levels < 1 µg/mL did not appear to benefit from anticoagulation while patients with D-dimer levels > 10 µg/mL derived the most benefit. There was no increase in transfusion requirement with any of the anticoagulants used.

Conclusion We conclude that COVID-19+ patients with moderate or severe illness benefit from anticoagulation and that apixaban has similar efficacy to enoxaparin in decreasing mortality in this disease.
Dielectric elastomer generator with piezoelectric offset
Authors: Cao Jianbo , Xu Ge , E Shiju , Zhao Tianfeng , Gao Zhao , Luo Hanpin
Published: November 2020

In the past studies, dielectric elastomer generators (DEGs) need a high voltage DC power supply to provide an offset voltage, which restricts the application of DEG technology in practical projects. To solve this problem, this study adopts piezoelectric materials to provide an offset voltage for DEGs and a self-priming circuit to recycle the energy generated by DEGs. A new DEG with piezoelectric offset is designed to solve the problem of self-supply in the DEG power generation process. Before the experiment, the mathematical model is established by analyzing the dielectric elastomer generator and piezoelectric offset circuit and self-priming circuit, and the above models are simulated through the MATLAB/Simulink software. The simulation results demonstrate that the elastic restoring force of dielectric elastomers overcomes the electric field force and converts mechanical energy into electrical energy, and piezoelectric materials can provide an offset voltage for DEGs. The experimental results are in good agreement with the simulation analysis, and the calculated power of DEG-SPC is 673 mW, which lay a foundation for further research on dielectric elastomer power generation technology.
Microstrip resonator for nonlinearity investigation of thin magnetic films and magnetic frequency doubler
Authors: Belyaev B. A. , Afonin A. O. , Ugrymov A. V. , Govorun I. V. , Solovev P. N. , Leksikov A. A.
Published: November 2020

A structure that consists of a λ/4 stepped-impedance microstrip resonator is proposed as an instrument for the investigation of nonlinear effects in thin magnetic films and also can be used as a microwave frequency doubler. A conversion efficiency of 0.65% is observed at a one-layer 100 nm Ni80Fe20 thin film at an input signal level of 4.6 W for a 1 GHz probe signal. The maximum measured conversion efficiency (1% at 1 GHz) was achieved for the 9-layer Ni80Fe20 film where 150 nm magnetic layers were separated by SiO2 layers.
Strong enhancement of coherent terahertz radiation by target ablation using picosecond laser pulses
Authors: Geng Yixing , Li Dongyu , Zhang Siyuan , Wu Minjian , Yang Tong , Wang Dan , Yan Lixin , Zhu Jungao , Hu Xiyao , Zhao Yanying , Yan Xueqing , Lin Chen
Published: November 2020

We have studied the generation of terahertz (THz) radiation via the interaction of an intense femtosecond laser pulse with aluminum (Al) and plastic targets pre-ablated by a picosecond ablation pulse. The measurements of the plasma shadowgraph and 1D-MULTI simulations show a similar micrometer density scale length of the pre-ablated plasma for the two types of targets after ablation. It is found that for the Al target, the intensity of THz radiation increased obviously under the condition of ablation, and only with the appropriate ablation delay time, the cutoff energy and charge of the accelerated protons also increased. 2D-simulations using the EPOCH program indicate that the strong enhancement of THz for the Al target is due to the increased number of energetic electrons from the interaction between the main laser and the ablated plasma. However, for the plastic targets, the intensity of THz radiation was almost vanished in the case of ablation, but the accelerated protons still existed and the cutoff energy even tended to increase. However, due to the lack of ability to simulate the molecular structure, we cannot distinguish between Al and plastic targets in the simulation. The mechanism of radiation suppression by ablation of the plastic target needs further investigation.
Tunable deep ultraviolet laser based near ambient pressure photoemission electron microscope for surface imaging in the millibar regime
Authors: Ning Yanxiao , Li Yifan , Wang Chao , Li Rongtan , Zhang Fengfeng , Zhang Shenjin , Wang Zhimin , Yang Feng , Zong Nan , Peng Qinjun , Xu Zuyan , Wang Xiaoyang , Li Rukang , Breitschaft Martin , Hagen Sebastian , Schaff Oliver , Fu Qiang , Bao Xinhe
Published: November 2020

A newly developed instrument comprising a near ambient pressure (NAP) photoemission electron microscope (PEEM) and a tunable deep ultraviolet (DUV) laser source is described. This NAP-PEEM instrument enables dynamic imaging of solid surfaces in gases at pressures up to 1 mbar. A diode laser (976 nm) can illuminate a sample from the backside for in situ heating in gases up to 1200 K in minutes. The DUV laser with a tunable wavelength between 175 nm and 210 nm is perpendicularly incident onto the sample surface for PEEM imaging of a wide spectrum of solids with different surface work functions. Using this setup, we have first demonstrated spatiotemporal oscillation patterns of CO oxidation reaction on Pt(110) from high vacuum to NAPs and gas-induced restructuring of metal nanostructures in millibar gases. The new facility promises important applications in heterogeneous catalysis, electrochemical devices, and other surface processes under nearly working conditions.
Using mathematics to diagnose, cure, and predict cardiac arrhythmia
Authors: Glass Leon
Published: November 2020

Mathematics can be used to analyze and model cardiac arrhythmia. I discuss three different problems. (1) Diagnosis of atrial fibrillation based on the time intervals between subsequent beats. The probability density histograms of the differences of the intervals between consecutive beats have characteristic shapes for atrial fibrillation. (2) Curing atrial fibrillation by ablation of the core of rotors. Recent clinical studies have proposed that ablating the core of rotors in atrial tissue can cure atrial fibrillation. However, the claims are controversial. One problem that arises relates to difficulties associated with developing algorithms to identify the core of rotors. In model tissue culture systems, heterogeneity in the structure makes it difficult to unambiguously locate the core of rotors. (3) Risk stratification for sudden cardiac death (SCD). Despite numerous clinical studies, there is still a need for improved criteria to assess the risk of SCD. I discuss the possibility of using the dynamics of premature ventricular complexes to help make predictions. The development of wearable devices to record and analyze cardiac rhythms offers new prospects for the diagnosis and treatment of cardiac arrhythmia.
Direct numerical simulations of turbulent periodic-hill flows with mass-conserving lattice Boltzmann method
Authors: Lin Wei-Jie , Li Ming-Jiun , Su Chi-Wei , Huang Xiao-Ying , Lin Chao-An
Published: November 2020

The multi-relaxation time lattice Boltzmann method is used to perform direct numerical simulations of laminar and turbulent pressure-driven flows within a channel with hill-shape periodic constriction for the first time. The simulations are conducted on a graphics processing unit cluster with two-dimensional domain decomposition to accelerate the computation. The hill-shape boundary is represented using the interpolated bounce back scheme. However, the scheme generates mass leakage across the boundary, which is more pronounced in the turbulent flow regime, and this may produce diverging solutions for turbulent flows. The mass leakage due to the local mass imbalance along the curved boundary is solved by modifying the distribution functions locally or globally, and both predict similar velocity distributions. Since the global correction method is more computing time-consuming, the local correction method is adopted. The present numerical implementation’s capability is first validated by performing direct numerical simulations of turbulent channel flow at Reτ = 180, and the current predicted results agree well with the benchmark solutions. Direct numerical simulations are further conducted for the turbulent flow over the periodic hill at Reh = 2800. Both the mean velocity and turbulent stress compare favorably with the benchmark solutions. The present simulation also correctly predicts the turbulence splatting effect near the windward hill. Both phenomena are in good accordance with the benchmark solutions.
Highly sensitive SWIR detector array based on nanoscale phototransistors integrated on CMOS readout
Authors: Liu Lining , Rabinowitz Jacob , Bianconi Simone , Park Min-Su , Mohseni Hooman
Published: November 2020

Ultra-sensitive and fast infrared imaging has become increasingly important in applications that require high frame rates at low light levels, such as exoplanet imaging. The sensitivity of conventional short-wave infrared cameras is limited by their readout noise level. This limitation can be addressed by the internal gain of the sensors, but only if fast response time and low dark current are achieved simultaneously. Recent theoretical predictions suggested that reducing the internal capacitance of detectors with internal gain can increase their sensitivity. Here, we show the experimental validation of this prediction for III–V heterojunction phototransistors. We have fabricated a 320 × 256 array of InGaAs/InP infrared phototransistors integrated with a conventional silicon readout circuit. The array is made of two groups of pixels: 50% are devices with a 1 μm base diameter and the other 50% with a 2 μm base diameter. Characterization of a large number of pixels shows that 1 μm devices have significantly higher sensitivity than 2 μm devices. These have an average noise equivalent photon sensitivity of about 20 photons at a camera frame rate of ∼500 frames per second, which is better than the best existing infrared cameras with a similar cutoff wavelength and frame rate. Interestingly, the processing variation in the 1 μm devices resulted in variation in sensitivity, and a good number of devices show sensitivity to less than 10 photons. These results suggest that the proposed phototransistors are promising for ultra-sensitive short-wavelength infrared cameras.
Development of a cantilever beam thrust stand for electric propulsion thrusters
Authors: Zhang H. , Li D. T. , Li H.
Published: November 2020

The application of electric thrusters on spacecrafts has become more and more extensive. Accurate, direct measurement of thrust is not only one of the most critical elements of electric thruster characterization but also one of the most difficult measurements to make in the ground test and verification of electric propulsion. It is hard to measure the thrust in a finite simulation environment due to small thrust and interference factors in the measurement. A cantilever beam thrust stand has been designed and tested in our propulsion laboratory. The device is used to measure the thrust of a plasma thruster multiple times a day. The thrust stand allows adjusting the instrument sensibility by changing the size of the cantilever beam. The range of thrust depends on the thrusters; e.g., for a 15 kg ion thruster, the thrust can vary from 10 mN up to 220 mN. Calibration of the system is carried out using calibrated mass. The balance results are compared to the thrust calculated using electrical parameters, showing an agreement within 3.16%.
Sub-kelvin thermometer for on-chip measurements of microwave devices utilizing two-level systems in superconducting microresonators
Authors: Wheeler J. , Vissers M. R. , Malnou M. , Hubmayr J. , Ullom J. N. , Gao J.
Published: November 2020

We present a superconducting microresonator thermometer based on two-level systems (TLSs), which is drop-in compatible with cryogenic microwave systems. The operational temperature range is 50–1000 mK (which may be extended to 5 mK), and the sensitivity (50–75 μK/Hz) is relatively uniform across this range. The miniature footprint that conveniently attaches to the feedline of a cryogenic microwave device facilitates the measurement of on-chip device temperature and requires no additional thermometry wiring or readout electronics. We demonstrate the practical use of these TLS thermometers to investigate static and transient chip heating in a kinetic inductance traveling-wave parametric amplifier operated with a strong pump tone. TLS thermometry may find broad application in cryogenic microwave devices such as superconducting qubits and detectors.
Optimal chordwise stiffness distribution for self-propelled heaving flexible plates
Authors: Wang Wenjiang , Huang Haibo , Lu Xi-Yun
Published: November 2020

The effect of non-uniform chordwise stiffness distribution on the self-propulsive performance of three-dimensional flexible plates is studied numerically. Some typical stiffness distributions, including uniform, declining, and growing distribution, are considered. First, the normalized bending stiffness K̃ is derived, which can well represent the overall bending stiffness of the non-uniform plates. For different non-uniformly distributed plates with the same K̃, the maximum displacement difference between the trailing and leading edges of the plate during the flapping is almost identical. There exists a common optimal K̃ at which all the plates achieve their optimal performance, i.e., the highest cruising speed and efficiency. Second, we reveal what kind of non-uniform distribution could be the best at a specific K̃ in terms of the propulsive performance. The force analysis indicates that a larger bending deformation in the anterior part for the growing distribution leads to a larger thrust. Hence, the large local slope along the anterior flexible plate is preferred to enhance the propulsive performance. The results obtained in this study may shed some light on a better understanding of the hydrodynamic effect on the self-propulsion of the non-uniform stiffness wings or fins of animals.
Metrics of Horowitz–Myers type with the negative constant scalar curvature
Authors: Liang Zhuobin , Zhang Xiao
Published: November 2020

We construct a one-parameter family of complete metrics of Horowitz–Myers type with the negative constant scalar curvature. We also verify a positive energy conjecture of Horowitz and Myers for these metrics.
Atomic structure and electronic properties of hydrogenated X (=C, Si, Ge, and Sn) doped TiO2: A theoretical perspective
Authors: Filippatos Petros-Panagis , Kelaidis Nikolaos , Vasilopoulou Maria , Davazoglou Dimitris , Chroneos Alexander
Published: November 2020

Titanium dioxide (TiO2) and especially its polymorph, anatase, are widely used transition-metal oxides for renewable energy applications such as photocatalytic and photovoltaic devices due to their chemical stability and their electrochemical and photocatalytic properties. However, the wide energy bandgap of anatase limits its photocatalytic ability and electron transport properties. Doping with appropriate elements is an established way to control and tune the optical and electronic properties of anatase such as conductivity, transparency, and bandgap. Metal doping can improve anatase’s properties as an electron transport layer, whereas non-metal (anion) doping is widely used to improve its photocatalytic activity. Herein, we investigate the effect of carbon group dopants in conjunction with hydrogenation of TiO2 by applying density functional theory. We find that hydrogenation has a positive impact on the structural and electronic properties of TiO2, thus making it an appropriate candidate for energy harvesting devices.
Drivers restricting biodiversity in Australian saline lakes: a review
Authors: Timms Brian V.
Published: November 2020

Inland saline lakes are well known to be less biodiverse than fresh waters. In Australia, the most important driver affecting biodiversity is salinity that imposes an inverse linear relationship. However, in detailed studies across a wide salinity spectrum, the relationship is scale dependent. This is mediated in part by the range of salinity tolerated becoming broader as the maximum tolerated salinity increases. Other factors of importance sometimes include hydrology, habitat heterogeneity, season, pH and oxygen, but these are usually not easy to quantify. Even rarer is the influence of colonisation by marine organisms, which is applicable only at some sites near the coastline and the influence of ionic proportions on the presence of some species and, hence, diversity. The contribution of predation or competition on diversity, reported in some overseas salinas, is suspected but yet to be proved in Australia. The crustacean component in saline lakes is more influenced by these drivers than is most of the insect fraction.
Sexually transmissible infections, partner notification and intimate relationships: a qualitative study exploring the perspectives of general practitioners and people with a recent chlamydia infection
Authors: Coombe Jacqueline , Goller Jane , Bittleston Helen , Vaisey Alaina , Sanci Lena , Groos Anita , Tomnay Jane , Temple-Smith Meredith , Hocking Jane
Published: November 2020

Background
Individuals diagnosed with a chlamydia infection are advised to notify their sexual partners from the previous 6 months so that they too can get tested and treated as appropriate. Partner notification is an essential component of chlamydia management, helping to prevent ongoing transmission and repeat infection in the index case. However, partner notification can be challenging, particularly in circumstances where a relationship has ended or transmission has occurred beyond the primary relationship. Methods: In this study we use data from 43 semistructured interviews with general practitioners (GPs) and people with a recent diagnosis of chlamydia. The interviews examined experiences of chlamydia case management in the general practice context. Here, we focus specifically on the effect of a chlamydia infection on intimate relationships in the context of the consultation and beyond.? Results: A chlamydia infection can have significant consequences for intimate relationships. Although GPs reported speaking to their patients about the importance of partner notification and participants with a recent chlamydia infection reported notifying their sexual partners, both would appreciate further support to engage in these conversations. Conclusions: Conversations with patients should go beyond simply informing them of the need to notify their sexual partners from the previous 6 months, and should provide information about why partner notification is important and discuss strategies for informing partners, particularly for those in ongoing relationships. Ensuring GPs have the training and support to engage in these conversations with confidence is vital.
Leukotriene B
4
licenses inflammasome activation to enhance skin host defense
Authors: Salina Ana Carolina Guerta , Brandt Stephanie L. , Klopfenstein Nathan , Blackman Amondrea , Bazzano Júlia Miranda Ribeiro , Sá-Nunes Anderson , Byers-Glosson Nicole , Brodskyn Claudia , Tavares Natalia Machado , Da Silva Icaro Bonyek Santos , Medeiros Alexandra I. , Serezani C. Henrique
Published: November 2020

Significance

Production of IL-1β is an essential component of the inflammatory response and host defense. IL-1β secretion is dependent on the activation of an intracellular platform termed inflammasome. The initial inflammatory signals that drive inflammasome activation remains elusive. Here, we show that the bioactive lipid leukotriene B
4
enhances both transcriptional and posttranscriptional programs that activate the inflammasome in vivo and in vitro. We identified critical signaling programs required for inflammasome assembly, IL-1β secretion, and its consequences in skin host defense. Our data also suggest that the prevention of LTB
4
actions might be an important therapeutic strategy to prevent IL-1β–dependent inflammatory diseases by inhibiting both first and second signals necessary for inflammasome activation.
The BAFFling persistence of memory B cells
Authors: Brooks Jeremy F. , Zikherman Julie
Published: November 2020

Although BAFF/BLyS and its receptor, BAFFR, play critical roles in naive B cell survival, the pathways involved in the persistence of memory B cells are largely unknown. In this issue of JEM, two groups, Müller-Winkler et al. (https://doi.org/10.1084/jem.20191393) and Lau et al. (https://doi.org/10.1084/jem.20191167), take complementary approaches to identify an essential role for BAFFR in the survival of memory B cells.
Imaging and dosimetric characteristics of 67 Cu
Authors: Merrick Michael J , Rotsch David A , Tiwari Ashok , Nolen Jerry , Brossard Thomas , Song Jeongseog , Wadas Thaddeus J , Sunderland John J , Graves Stephen A
Published: November 2020

In recent years the use of beta-emitting radiopharmaceuticals for cancer therapy has expanded rapidly following development of therapeutics for neuroendocrine tumors, prostate cancer, and other oncologic malignancies. One emerging beta-emitting radioisotope of interest for therapy is 67Cu (t1/2: 2.6 d) due to its chemical equivalency with the widely-established positron-emitting isotope 64Cu (t1/2: 12.7 h). In this work we evaluate both the imaging and dosimetric characteristics of 67Cu, as well as producing the first report of SPECT/CT imaging using 67Cu. To this end, 67Cu was produced by photon-induced reactions on isotopically-enriched 68Zn at the Low-Energy Accelerator Facility (LEAF) of Argonne National Laboratory, followed by bulk separation of metallic 68Zn by sublimation and radiochemical purification by column chromatography. Gamma spectrometry was performed by efficiency-calibrated high-purity germanium (HPGe) analysis to verify absolute activity calibration and establish radionuclidic purity. Absolute activity measurements corroborated manufacturer-recommended dose-calibrator settings and no radionuclidic impurities were observed. Using the Clinical Trials Network anthropomorphic chest phantom, SPECT/CT images were acquired. Medium energy (ME) SPECT collimation was found to provide the best image quality from the primary 185 keV gamma emission of 67Cu. Reconstructed images of 67Cu were similar in quality to images acquired using 177Lu. Recovery coefficients were calculated and compared against quantitative images of 99mTc, 177Lu, and 64Cu within the same anthropomorphic chest phantom. Production and clinical imaging of 67Cu appears feasible, and future studies investigating the therapeutic efficacy of 67Cu-based radiopharmaceuticals are warranted.
Bipolaron formed through electron-hole excitation
Authors: Wu Chen-Huan
Published: November 2020

We investigate the electronic properties and electron correlations of the bipolaron formed with the participation of electron-hole excitations in the presence of Yukawa-type coupling (between nonrelativistic fermions) in three spatial dimension. The electron-hole excitation, which is necessary to the formation of bipolaron, leads to imaginary particle-hole channel order parameter, and provide finite boson field mass to the single-polaron dispersion in a broken-symmetry phase. We found that the bipolaron exhibits fermi-liquid features as long as the long-range strong interaction is suppressed, and it behave differently compared to the single-polaron. The bosonic momentum determines the mass of boson field propagator and the gap function, and it also related to the self-energies and the single-particle Green’s functions. The Thouless criterion is also used during the calculation of gap equation at critical temperature (which becomes lower in weak-coupling regime), which corresponds to the pole (instability) of the pair propagator in zero center-of-mass freamwork. The mean field term and the bosonic fluctuation-induced contribution to free energy in Aslamazov-Larkin-type bipolaron diagram are also studied.
Magnetism and optical properties of (Fe, Ni) co-doped 3C-SiC from first principles calculation
Authors: Lin Long , Lou Mengsi , Huang Jingtao , Tao Hualong , Chen Ruixin
Published: November 2020

The electronic structures, magnetic properties and optical properties of (Fe, Ni) co-doped 3C-SiC system are systematically studied based on the first principles calculation. The results show that Fe single doped, Ni single doped, and (Fe, Ni) co-doped system all induce magnetism. The most stable (Fe, Ni) co-doped systems is determined by calculating the magnetic coupling energies of ten different configuration. The (Fe, Ni) co-doped systems indicated that have a higher Curie temperature and the (1, 7) configuration significantly improves FM stability compared to other configurations. In addition, the results of the optical properties of (Fe, Ni) co-doped 3C-SiC exist absorption in the entire infrared, visible, and ultraviolet light regions, which has a substantial change compared with the undoped system. An effective way is comfirmed to improve the magnetic and optical performance of 3C-SiC.
Band-stop filter based on tunable Fano resonance and electromagnetically induced transparency in metal-dielectric-metal waveguide coupling systems
Authors: Guo Yiyuan , Huo Yiping , Niu Qiqiang , He Qian , Hao Xiangxiang
Published: November 2020

Metal-dielectric-metal (MIM) waveguide coupling systems based on surface plasmon polaritons (SPPs) are designed and studied. The finite element method is used to simulate the transmission spectra of structures in the whole simulation process. One waveguide coupling system consists of an inverted T-shaped cavity with defect (ITD) and a waveguide with a metal wall. The filter band appears in the transmission spectrum due to the opposite direction of two Fano resonances. The filter band width and the filtering range can be tuned effectively by changing the structure parameters. In this system, the center frequency and bandwidth of the filter band are 1330 nm and 114 nm, respectively. The insertion loss and reflection loss are −1.41 dB and −16.89 dB, respectively. The optimization is carried out on the basis of the first system in order to improve the filtering performance. Optimized waveguide coupling system contains an ITD and a waveguide with a slot cavity. Electromagnetically induced transparency (EIT) and Fano resonance exist simultaneously, and the filter band is induced in the transmission spectrum. In this system, the center frequency and bandwidth of the filter band are 1412 nm and 120 nm, respectively. The insertion loss and reflection loss are −0.50 dB and −37.32 dB, respectively. EIT and Fano resonance can not only be regulated independently, but also be regulated simultaneously by changing the structural parameters. And the intensity of EIT and the width of the filter band can be manipulated with changes of the structural parameters. The transmission response of SPPs propagating in the structure can be adjusted dynamically. Moreover, these novel SPPs optical waveguide structures have good filtering efficiency and can meet different filtering needs. These results show that the proposed systems are promising for filter, slow light device and photonic device integration applications.
Ionizing blast waves in a non-ideal gas under isothermal flow condition: Power Series Method
Authors: Sharma Kajal , Chauhan Astha , Arora Rajan
Published: November 2020

In this work, the propagation of blast waves in a non-ideal gas for isothermal flow with the effect of the azimuthal magnetic field is investigated. It is supposed that the magnetic field is directed orthogonally to the motion of the gas particles having zero electrical resistance. Approximate solutions are obtained analytically by expanding the flow parameters in the form of power series for the cylindrically symmetric motion using Sakurai’s technique. The flow variables are determined behind the shock. The effects of the parameter of non-idealness and the magnetic field strength on the flow density, velocity, pressure and magnetic pressure of the flow are discussed in detail and shown graphically. It is observed that an increase in the value of the parameter of non-idealness causes a decrease in the flow velocity, density and magnetic pressure, while pressure behaves reversely. The magnetic pressure and flow velocity increase with the magnetic field, while the flow density and pressure decrease with an increase in the magnetic field. Some of the applications of the present work include experiments on pinch effect, an explosion of long thin wire, and certain axially symmetric hypersonic problems.
ZnSe-based Faraday isolator for high-power mid-IR lasers
Authors: Mironov E A , Palashov O V , Snetkov I L , Balabanov S S
Published: November 2020

High-power Faraday isolators (FIs) for mid-IR radiation are of great practical importance, since they expand the capabilities of constructing optical schemes of solid state mid-IR lasers, which have progressed significantly in recent years. Isolators for high-power radiation with a wavelength of 1.5–2 µm are especially important for the solid-state lasers in order to cover the entire mid-IR range. We developed the FI for high-power mid-IR radiation based on CVD-ZnSe polycrystals and studied its characteristics. The isolation of radiation with a wavelength of 1940 nm was demonstrated. No thermally induced depolarization effects were observed for radiation with a wavelength of 1940 nm up to 20 W. For studying the limitations of the isolator in terms of operating power, experiments with more powerful radiation at a wavelength of 1075 nm were performed. Estimates show the possibility of isolating radiation with a power of up to 200 W with the isolation ratio of the device of ∼25 dB. Ways to improve the device are discussed. The level of cold depolarization can be reduced, by annealing the magneto-optical elements. The device can be compactified by using a different optical isolation scheme and a different organization of the magnetic system. This path will also allow compensating thermally induced depolarization and, according to the estimates, will ensure the isolation of mid-IR radiation of a kilowatt power level.