bluuebunny/crossref_metadata_2025 huggingface dataset:
The utility of De Ritis Ratio in predicting prognosis in testicular cancer
Authors: Guner Ekrem , Seker Kamil Gokhan , Arikan Yusuf , Huseynov Coshgun , Sam Emre , Ozdal Ozdem Levent
Published: March 2020

Objective We aimed to investigate the possible association between testicular cancer prognosis and De Ritis ratio (AST/ALT).

Methods The medical records of all patients who underwent radical inguinal orchiectomy at a single tertiary in Istanbul, Turkey between 2006 and 2017 were retrospectively analyzed. Investigated parameters included patients’ demographics, complete blood count and blood biochemistry results, pathology results, treatment schemes, imaging results, and survival. De Ritis ratio was calculated as follows: AST/ALT.

Results A total of 171 patients with a mean age of 32.6 ± 10.1 years were included in the study. 73 patients had T1, 83 had T2, 13 had T3 and 2 had T4 disease. Rete testis invasion was detected in 74 patients (43.3 %) as well as lymphovascular invasion in 93 (54.4 %) and tunica albuginea invasion in 80 (46.8 %) patients. The cut-off value for AST/ALT was set at 1.35 [Area Under Curve (AUC): 0.791 with a sensitivity of 80 % and specificity of 73 %]. No statistically significance was observed between patients with and without elevated AST/ALT according to rete testis invasion, lymphovascular invasion, tunica albuginea invasion, and tunica vaginalis invasion (p = .25, p = .63, p = 1.0 and p = 1.0, respectively). 28.2 % of patients with seminoma had AST/ALT > 1.35 however 41.9 % of patients with non-seminoma pathology had AST/ALT > 1.35 (p = .078). Mean estimated survival time of patients with AST/ALT > 1.35 was higher than those with AST/ALT < 1.35, 91.8 versus 70.4 months, p < .001). As seen in Kaplan-Meier analysis elevated AST/ALT is associated with early-term mortality.

Conclusion De Ritis ratio was shown to be significantly associated with unfavorable prognosis. De Ritis ratio might serve as a prognostic biomarker in testicular tumor besides well-known tumor markers such as beta-human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP) and lactate dehydrogenase (LDH).
Total Synthesis of Asparenydiol by Two Sonogashira Cross-Coupling Reactions Promoted by Supported Pd and Cu Catalysts
Authors: Evangelisti Claudio , Angelici Gaetano , Casotti Gianluca , Fusini Graziano , Ferreri Matteo , Pardini Luca Fidia , Carpita Adriano
Published: March 2020

Asparenydiol, which is an important natural compound with potential pharmacological activities, was synthesized through two Sonogashira­ cross-coupling reactions catalyzed by supported Pd and Cu catalysts and by a Mitsunobu etherification. The optimization of the Sonogashira­ couplings allowed the use of catalysts supported on different matrices with good results in terms of catalytic efficiency and yields.
Opioid Naive Surgeons and Opioid-Tolerant Patients: Can Education Alter Prescribing Patterns to Total Knee Arthroplasty Patients?
Authors: King Connor A. , Landy David C. , Bradley Alexander T. , Scott Bryan , Curran John , Devanagondi Shwetha , Balach Tessa , Mica Megan Conti
Published: March 2020

Patterns of opioid overprescribing following arthroplasty likely developed given that poor pain control can diminish patient satisfaction, delay disposition, and lead to complications. Recently, interventions promoting responsible pain management have been described, however, most of the existing literature focuses on opioid naive patients. The aim of this study was to describe the effect of an educational intervention on opioid prescribing for opioid-tolerant patients undergoing primary total knee arthroplasty (TKA). As the start to a quality improvement initiative to reduce opioid overprescribing, a departmental grand rounds was conducted. Prescribing data, for the year before and after this intervention, were retrospectively collected for all opioid-tolerant patients undergoing primary TKA. Opioid prescribing data were standardized to mean morphine milligram equivalents (MME). Segmented time series regression was utilized to estimate the change in opioid prescribing associated with the intervention. A total of 508 opioid-tolerant patients underwent TKA at our institution during the study period. The intervention was associated with a statistically significant decrease of 468 mean MME (23%) from 2,062 to 1,594 (p = 0.005) in TKA patients. This study demonstrates that an educational intervention is associated with decreased opioid prescribing among opioid-tolerant TKA patients. While the effective management of these patients is challenging, surgeon education should be a key focus to optimizing their care.
Laparoscopic Fundoplication for the Surgical Management of Gastroesophageal Reflux Disease in Children
Authors: Dekonenko Charlene , Holcomb George W.
Published: March 2020

Gastroesophageal reflux (GER) is common in infants generally resolving in early childhood. However, gastroesophageal reflux disease (GERD) is diagnosed when persistent troublesome symptoms and/or complications of GER develop. These symptoms and complications can significantly affect the quality of life, thus requiring medical or surgical treatment. Medical management is typically trialed, but operative treatment is indicated with severe symptoms such as aspiration pneumonia, apneic episodes, bradycardia, apparent life-threatening events, severe vomiting, failure to thrive, esophagitis, stricture, and failed medical therapy. We review the recent literature on the indications and outcomes for laparoscopic fundoplication in the management of pediatric GERD.
Outcomes following Revision Total Knee Arthroplasty Septic versus Aseptic Failure: A National Propensity-Score-Matched Comparison
Authors: Dai Wen-Li , Lin Ze-Ming , Shi Zhan-Jun , Wang Jian
Published: March 2020

Although periprosthetic joint infection (PJI) has been hypothesized to increase the risk of complications following revision total knee arthroplasty (TKA), strong evidence linking the two is lacking. The aim of this study was to determine whether PJI is an independent risk factor for inpatient perioperative complications, and increased resource use in patients undergoing revision TKA. We relied on the US Nationwide Inpatient Sample (NIS) to identify patients with PJI or non-PJI treated with revision TKA between 2002 and 2014. Overall, 5,316 (16.4%) and 27,033 (83.6%) patients were categorized as PJI and non-PJI, respectively. To adjust for potential baseline differences between the two groups, propensity-score-based matching was performed. This resulted in 5,187 (50%) PJI patients matched to 5,187 (50%) non-PJI patients. The rates of postoperative complications, blood transfusions, prolonged length of stay (pLOS), in-hospital cost, and in-hospital mortality were assessed for both groups. Multivariable logistic regression analyses were performed within the cohort after propensity-score matching. For PJI versus non-PJI, respectively, the following rates were recorded: blood transfusions, 28.3 versus 18.4% (p < 0.0001); postoperative complications, 27.5 versus 19.8% (p < 0.0001); pLOS (>4 d), 61.9 versus 26.9% (p < 0.0001); in-hospital cost (>$39,929), 55.8 versus 44.2% (p < 0.0001); in-hospital mortality, 0.6 versus 0.3% (p = 0.016). In multivariable logistic regression analyses, PJI patients were more likely to receive a blood transfusion (odds ratio [OR]: 1.78; p < 0.0001), to experience postoperative complications (OR: 1.56; p < 0.0001), to have a higher in-hospital cost (OR: 1.65; p < 0.0001), to have a pLOS following surgery following surgery (OR: 4.69; p < 0.0001), and to have a higher in-hospital mortality (OR: 2.14; p = 0.019). After adjustment for potential selection biases, PJI is associated with more adverse perioperative outcomes and resource use than non-PJI patients. This is a Level II (level of evidence), prognostic study.
Associations between Anterior Cruciate Ligament Injuries and Patella Alta and Trochlear Dysplasia in Adults Using Magnetic Resonance Imaging
Authors: Akgün Ayşe Serap , Agirman Mehmet
Published: March 2020

The aim of this study was to research the associations between anterior cruciate ligament (ACL) injuries and patella alta and trochlear dysplasia in adult patients using magnetic resonance imaging (MRI). This retrospective study included 221 adult patients: 110 with acute complete noncontact ACL tears and 111 without ACL injuries who underwent knee MRI procedures between May 2016 and July 2018. After the ACL injuries were verified using the sagittal proton density images, the patellar height and patellar tendon length were measured on the sagittal T1-weighted images, and the Insall–Salvati ratio (ISR) was calculated. In the axial proton density MRI scans, according to the Dejour and Le Coultre classification of trochlear dysplasia, the knees were classified as normal or as types A, B, C, or D. The patellar length was not significantly different between the patient and control groups (41.5 ± 3.3 vs. 41.0 ± 2.9 mm, respectively). An increased patellar tendon length (46.1 ± 3.9 vs. 44.5 ± 3.4 mm, respectively) and an increased ISR (1.11 ± 0.08 vs. 1.08 ± 0.06, respectively) were measured in the patient group (with the ACL tears). In the group with the ACL tears, the rate of trochlear dysplasia was higher (15.45%) than that in the healthy group (4.5%). Of the 17 trochlear dysplasia patients in the ACL group, 11 were type A (10%), 2 were type B (1.82%), 3 were type C (2.73%), and 1 was type D (0.91%). Results showed increased patellar tendon lengths, ISRs, and trochlear dysplasia in the patients with the ACL injuries when compared with the healthy control group. Although the causative relationship has not yet been clearly elucidated, one should keep in mind that these variations may be risk factors for ACL tears.
Is Early Amniotomy Associated with Higher Likelihood of Vaginal Birth after Cesarean?
Authors: Varvoutis Megan S. , Sayres Lauren C. , Dotters-Katz Sarah K.
Published: March 2020

Objective The study aims to reduce cesarean rates, eligible women are being offered an option of vaginal birth after cesarean (VBAC). However, little data exist regarding efficacy of amniotomy as a tool in this population. We sought to evaluate the impact of early amniotomy on VBAC success.

Study Design This is a secondary analysis case-control study using the MFMU (Maternal-Fetal Medicine Units Network) Cesarean Registry. Women were included if they had a singleton pregnancy, were attempting VBAC, and underwent induction with artificial rupture of membranes. Cases were defined as subjects with successful VBAC; controls were defined as subjects with failed trial of labor after cesarean (TOLAC). Early amniotomy was defined as amniotomy at <4 cm. Demographic and obstetric characteristics were compared and multivariate logistic regression was performed.

Results A total of 1,490 women were included. Early amniotomy occurred in 59.5% with VBAC versus 63.2% with failed TOLAC (p = 0.24). After controlling for body mass index, prior vaginal delivery, African–American race, labor length, gestational age, birthweight, epidural use, Foley catheter balloon ripening, induction method and oxytocin use, early amniotomy was associated with a 34% decrease in VBAC success (p < 0.01). Women who had early amniotomy did not have higher rates of chorioamnionitis (2.8 vs. 2.9%, p > 0.99).

Conclusion Unlike data from nulliparous women, our data suggest that induction with early amniotomy does not increase the likelihood of VBAC.
Does Body Mass Index Cause a Clinical Difference in Simultaneous Bilateral and Unilateral Knee Arthroplasty?
Authors: Ogur Hasan Ulas , Cicek Hakan , Seyfettinoglu Fırat , Tuhanioglu Ümit , Aydoğdu Ali , Kılıcarslan Kasım
Published: March 2020

This study aims to investigate clinical and functional factors in patients undergoing unilateral and simultaneous bilateral total knee arthroplasty (TKA) who were classified into subgroups of nonobese, obese, and morbidly obese, and to determine perioperative and postoperative complications. We conducted an evaluation of 489 nonobese, obese, and morbidly obese patients who underwent TKA due to primary knee osteoarthritis between January 2006 and December 2013. The arthroplasties were performed by three different surgeons. Patients who underwent unilateral (group 1) or simultaneous bilateral (group 2) TKAs were divided into subgroups in accordance with BMI levels, that is, (a) nonobese (BMI < 30 kg/m2), (b) obese (BMI = 30–34.9 kg/m2), and (c) morbidly obese (BMI ≥35 kg/m2). Clinical and functional assessments were performed using Knee Society Scores (KSSs), the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC), and range of motion (ROM) values. Perioperative and early postoperative complications were assessed. The mean follow-up period was 46.65 months (minimum: 24 months; maximum: 84 months). There were no significant differences between the patients undergoing unilateral or simultaneous bilateral TKA procedures regarding postoperative ROM, WOMAC indices, and KSSs (p > 0.05), except for morbidly obese patients. Most intraoperative and early postoperative complications occurred in the morbidly obese group, especially in those undergoing simultaneous bilateral TKA procedures (p < 0.001). Unilateral and simultaneous bilateral TKA procedures showed no differences regarding ROM, clinical scores, and perioperative and early postoperative complications in nonobese and obese patients. A moderate increase was detected in complication rates in the unilateral TKA morbidly obese patients (group 1c); however, morbidly obese patients constituted the major risk group in simultaneous bilateral TKA patients (group 2c) regarding clinical scores (lower WOMAC scores and KSSs) and the development of complications.
Omphalocele in Finland from 1993 to 2014: Trends, Prevalence, Mortality, and Associated Malformations—A Population-Based Study
Authors: Raitio Arimatias , Tauriainen Asta , Syvänen Johanna , Kemppainen Teemu , Löyttyniemi Eliisa , Sankilampi Ulla , Vanamo Kari , Gissler Mika , Hyvärinen Anna , Helenius Ilkka
Published: March 2020

Inroduction The aim of this study is to assess the changes in prevalence, mortality and termination pregnancy of omphalocele, and to identify associated anomalies.

Materials and Methods A population-based nationwide register study. All cases with omphalocele were identified in the Finnish Register of Congenital Malformations and the Care Register for Health Care from 1993 to 2014 including live births, stillbirths, and terminations of pregnancy due to fetal anomalies. Associated anomalies were recorded and analyzed, and perinatal and infant mortality and prevalence were calculated.

Results There were 600 cases with omphalocele including 229 live births, 39 stillbirths, and 332 (55%) abortions. Birth prevalence in Finland was 1.96 per 10,000 births with no consistent trend over time. However, total prevalence was much higher (4.71/10,000) because more than half of these families chose option for the termination of pregnancy. Omphalocele is often complicated with other anomalies; most commonly chromosomal abnormalities (9.3%), heart defects (6.3%), central nervous system anomalies (3.0%), gastrointestinal, and urogenital malformations (both 2.0%). Proportion of chromosomal and central nervous system abnormalities were even higher in terminated pregnancies. Overall infant mortality was 22%. Total 1-year survival rates for isolated omphalocele, cases with multiple anomalies and neonates with chromosomal defects were 80, 88, and 17%, respectively.

Conclusion Omphalocele is a rare congenital anomaly, often associated with other malformations. Our data suggest that isolated cases may be more common than previously thought. In the absence of chromosomal defects, survival is reasonably good. Regardless, more than half of these pregnancies are often terminated.
Discontinuity-induced intermittent synchronization transitions in coupled non-smooth systems
Authors: Yi Ming , Wang Canjun , Yang Keli
Published: March 2020

The synchronization transition in coupled non-smooth systems is studied for increasing coupling strength. The average order parameter is calculated to diagnose synchronization of coupled non-smooth systems. It is found that the coupled non-smooth system exhibits an intermittent synchronization transition from the cluster synchronization state to the complete synchronization state, depending on the coupling strength and initial conditions. Detailed numerical analyses reveal that the discontinuity always plays an important role in the synchronization transition of the coupled non-smooth system. In addition, it is found that increasing the coupling strength leads to the coexistence of periodic cluster states. Detailed research illustrates that the periodic clusters consist of two or more coexisting periodic attractors. Their periodic trajectory passes from one region to another region that is divided by discontinuous boundaries in the phase space. The mutual interactions of the local nonlinearity and the spatial coupling ultimately result in a stable periodic trajectory.
Classical Wigner model based on a Feynman path integral open polymer
Authors: Svensson S. Karl-Mikael , Poulsen Jens Aage , Nyman Gunnar
Published: March 2020

The classical Wigner model is one way to approximate the quantum dynamics of atomic nuclei. Here, a new method is presented for sampling the initial quantum mechanical distribution that is required in the classical Wigner model. The new method is tested for the position, position-squared, momentum, and momentum-squared autocorrelation functions for a one-dimensional quartic oscillator and double well potential as well as a quartic oscillator coupled to harmonic baths of different sizes. Two versions of the new method are tested and shown to possibly be useful. Both versions always converge toward the classical Wigner limit. For the one-dimensional cases, some results that are essentially converged to the classical Wigner limit are acquired and others are not far off. For the multi-dimensional systems, the convergence is slower, but approximating the sampling of the harmonic bath with classical mechanics was found to greatly improve the numerical performance. For the double well, the new method is noticeably better than the Feynman–Kleinert linearized path integral method at reproducing the exact classical Wigner results, but they are equally good at reproducing exact quantum mechanics. The new method is suggested as being interesting for future tests on other correlation functions and systems.
A bridged loop gap resonator (BLGR) for small animal imaging by 1.5 T MRI systems
Authors: Staat C. , Mützel M. , Haase A.
Published: March 2020

A bridged loop gap resonator (BLGR) was developed as a transmit and receive coil for a mobile insert to be used for small animal proton imaging by 1.5 T MRI devices. The insert system has its own gradient system, radio frequency (RF) transmit and receive coil, and control and signal processing unit. The reflection S11 and transmission S21 parameters, quality factor (Q), sensitivity, signal to noise ratio (SNR), and maps of the static (B0) and RF (B1) magnetic flux densities were measured. The RF coil was developed starting from a loop gap resonator (LGR) for a balanced LGR and a shielded balanced LGR for a shielded bridged balanced LGR. The purpose of developing this device is to minimize the influence of the sample and surroundings on the RF coil parameters. The final design of the BLGR does not require retuning after a sample change. A 3D image of a mouse in formalin was acquired with a fast low angle shot (FLASH) MRI sequence. The SNR was calculated from one FLASH image. The signal for SNR calculation was acquired from a gadolinium-doped water sample and the noise from the air outside of the sample. This article verifies that the BLGR is viable for small animal nuclear magnetic resonance imaging at 1.5 T and is independent of sample size and material.
Novel ring-type measurement system of shear yield stress for magnetorheological fluid under high temperature
Authors: Li Hao-Peng , Chen Fei , Wang Ge , Tian Zu-Zhi , Ji Jin-Jie
Published: March 2020

In order to investigate the shear yield stress of magnetorheological (MR) fluid at different temperatures, shear gaps, and shear rates, a ring measurement system is designed based on the MR characteristics. The magnetic field and temperature field of the system are simulated and analyzed, which proves that the design of the measurement system is reasonable. On this basis, the measurement system is manufactured and experiments are carried out to verify its performance. The results show that the system can provide a uniform and strong enough magnetic field to make MR effects occur. Meanwhile, the temperature of the shear gap can reach 100 °C in 610 s, and it can increase up to 240 °C when heating continues, which can provide stable measurement conditions at different temperatures, especially at high temperatures. All the results of the experiments show that the measurement system meets the requirements of measuring the shear yield stress of MR fluid. To test the accuracy of the measurement system, repeated experiments are carried out as well. The shear yield stress by the system is almost the same as that provided by the manufacturer, showing excellent measuring precision. The repeatability error of the measurement system is less than 4.02%, indicating that the measurement system is of high accuracy.
A control hardware based on a field programmable gate array for experiments in atomic physics
Authors: Bertoldi A. , Feng C.-H. , Eneriz H. , Carey M. , Naik D. S. , Junca J. , Zou X. , Sabulsky D. O. , Canuel B. , Bouyer P. , Prevedelli M.
Published: March 2020

Experiments in Atomic, Molecular, and Optical (AMO) physics require precise and accurate control of digital, analog, and radio frequency (RF) signals. We present control hardware based on a field programmable gate array core that drives various modules via a simple interface bus. The system supports an operating frequency of 10 MHz and a memory depth of 8 M (223) instructions, both easily scalable. Successive experimental sequences can be stacked with no dead time and synchronized with external events at any instructions. Two or more units can be cascaded and synchronized to a common clock, a feature useful to operate large experimental setups in a modular way.
Edge-pixel referencing suppresses correlated baseline noise in heterodyned spectroscopies
Authors: Robben Kevin C. , Cheatum Christopher M.
Published: March 2020

Referencing schemes are commonly used in heterodyned spectroscopies to mitigate correlated baseline noise arising from shot-to-shot fluctuations of the local oscillator. Although successful, these methods rely on careful pixel-to-pixel matching between the two spectrographs. A recent scheme introduced by Feng et al. [Opt. Express 27(15), 20323–20346 (2019)] employed a correlation matrix to allow free mapping between dissimilar spectrographs, leading to the first demonstration of floor noise limited detection on a multichannel array used in heterodyned spectroscopy. In addition to their primary results using a second reference spectrometer, Feng et al. briefly demonstrated the flexibility of their method by referencing to same-array pixels at the two spectral edges (i.e., edge-pixel referencing). We present a comprehensive study of this approach, which we term edge-pixel referencing, including optimization of the approach, assessment of the performance, and determination of the effects of background responses. We show that, within some limitations, the distortions due to background signals will not affect the 2D IR line shape or amplitude and can be mitigated by band narrowing of the pump beams. We also show that the performance of edge-pixel referencing is comparable to that of referencing to a second spectrometer in terms of noise suppression and that the line shapes and amplitudes of the spectral features are, within the measurement error, identical. Altogether, these results demonstrate that edge-pixel referencing is a powerful approach for noise suppression in heterodyned spectroscopies, which requires no new hardware and, so, can be implemented as a software solution for anyone performing heterodyned spectroscopy with multichannel array detectors already.
Time-dependent modeling of coupled plasma-wall dynamics
Authors: Smirnov R. D. , Krasheninnikov S. I. , Umansky M. V.
Published: March 2020

Effects of dynamic wall outgassing on divertor plasma during an edge localized mode (ELM)-like heat pulse are modeled using the newly coupled edge plasma code UEDGE and wall reaction-diffusion code FACE. Different divertor regimes are simulated depending on the degree of the plasma detachment. It is shown that hydrogen outgassing from the divertor target plate induced by ELM pulse in the semi-detached regime can trigger deep plasma detachment. The induced detachment does not spontaneously reverse after the pulse due to ineffective implantation of low energy plasma hydrogen in the target material. We also show that plasma neutrals play an essential role in heat transport in a detached divertor. The modeled hydrogen dynamics in the wall material demonstrates that the heat pulse leads to enhanced hydrogen transport toward the wall bulk.
Investigation on ion behavior in magnetically shielded and unshielded Hall thrusters by laser-induced fluorescence
Authors: Duan Xingyue , Cheng Mousen , Yang Xiong , Guo Ning , Li Xiaokang , Wang Moge , Guo Dawei
Published: March 2020

Non-intrusive characterization of the ion velocity distribution functions at several points of interest in 600 W magnetically shielded MSHT-600 and unshielded USHT-600 Hall thrusters plume by laser-induced fluorescence was conducted. Several visual clues supporting the magnetic shielding effect of MSHT-600 were presented. The measured ion axial velocity distribution functions show that the ion axial velocity is higher and observed to reach the maximum at nearer location to the exit plane on the centerline in the magnetically shielded Hall thruster than that in the unshielded one under the same operating conditions but uniformly distributed in the radial direction when ignoring the slower population for both thrusters. These results are in accordance with the higher specific impulse measured in several other shielded Hall thrusters. Moreover, the ion axial velocity on the centerline is higher than the average axial velocity at other radial locations for the same axial distance downstream of the exit plane in USHT-600, while the higher plume divergence or the inner pole erosion causes the velocity on the centerline to decrease in MSHT-600. The downstream shift of the accelerating potential and electric field distribution are also the typical features in magnetically shielded Hall thrusters as reported in other studies. Finally, the xenon ion velocity vector fields show that the ion population starts to meet and diverge further downstream of the exit plane in MSHT-600 than that in USHT-600, which may be associated with the difference of the plume divergence.
Collision cross sections and nonequilibrium viscosity coefficients of N2 and O2 based on molecular dynamics
Authors: Mankodi Tapan K. , Bhandarkar Upendra V. , Myong R. S.
Published: March 2020

This study examines the collision dynamics of atom–atom, atom–molecule, and molecule–molecule interactions for O–O, N–N, O2–O, N2–N, O2–N, N2–O, O2–O2, N2–N2, and N2–O2 systems under thermal nonequilibrium conditions. Investigations are conducted from a molecular perspective using accurate O4, N4, and N2O2 ab initio potential energy surfaces and by performing Molecular Dynamics (MD) simulations. The scattering angle and collision cross sections for these systems are determined, forming the basis for better collision simulations. For molecular interactions, the effect of the vibrational energy on the collision cross section is shown to be significant, which in turn has a profound effect on nonequilibrium flows. In contrast, the effect of the rotational energy of the molecule is shown to have a negligible effect on the cross section. These MD-based cross sections provide a theoretically sound alternative to the existing collision models, which only consider the relative translational energy. The collision cross sections reported herein are used to calculate various transport properties, such as the viscosity coefficient, heat conductivity, and diffusion coefficients. The effect of internal energy on the collision cross sections reflects the dependence of these transport properties on the nonequilibrium degree. The Chapman–Enskog formulation is modified to calculate the transport properties as a function of the trans-rotational and vibrational temperatures, resulting in a two-temperature nonequilibrium model. The reported work is important for studying highly nonequilibrium flows, particularly hypersonic re-entry flows, using either particle methods or techniques based on the conservation laws.
Interface charge engineering in AlTiO/AlGaN/GaN metal–insulator–semiconductor devices
Authors: Nguyen Duong Dai , Suzuki Toshi-kazu
Published: March 2020

Toward interface charge engineering in AlTiO/AlGaN/GaN metal-insulator-semiconductor (MIS) devices, we systematically investigated insulator-semiconductor interface fixed charges depending on the composition of the AlTiO gate insulator obtained by atomic layer deposition. By evaluating the positive interface fixed charge density from the insulator-thickness dependence of the threshold voltages of the MIS devices, we found a trend that the interface fixed charge density decreases with the decrease in the Al composition ratio, i.e., increase in the Ti composition ratio, which leads to shallow threshold voltages. This trend can be attributed to the large bonding energy of O-Ti in comparison with that of O-Al and to consequent possible suppression of interface oxygen donors. For an AlTiO gate insulator with an intermediate composition, the MIS field-effect transistors exhibit favorable device characteristics with high linearity of transconductance. These results indicate a possibility of interface charge engineering using AlTiO, in addition to energy gap engineering and dielectric constant engineering.
Nonlinear spin waves in ferromagnetic/superconductor hybrids
Authors: Golovchanskiy I. A. , Abramov N. N. , Stolyarov V. S. , Golubov A. A. , Ryazanov V. V. , Ustinov A. V.
Published: March 2020

This work is focused on the numerical investigation of spin waves that propagate in nonlinear ferromagnet/superconductor bilayered films and periodic structures. The nonlinearity in these hybrid structures emerges due to the non-monotonous dependence of magnetization of a superconducting subsystem on the magnetic field, which is characterized by the superconducting critical field. It is shown that at relatively high amplitudes of spin waves in comparison to the superconducting critical field, the spin-wave spectrum changes drastically: the spin-wave spectral line can either bifurcate or stretch continuously depending on the type of considered superconductor. In addition, in the case of propagation of spin waves with relatively high amplitude in periodic magnonic metamaterials, additional zero-group-velocity modes appear that are known as flatbands. Overall, these findings suggest a versatile way for tunability of the spin-wave spectrum in nonlinear ferromagnet/superconductor structures by changing the excitation signal in respect to the superconducting critical field.
Free surface effects on spanwise turbulent structure in the far-field of submerged jets
Authors: Essel Ebenezer E. , Roussinova Vesselina , Balachandar Ram
Published: March 2020

The flow structure in the cross-sectional and spanwise planes of a turbulent round jet interacting with a free surface has been studied using planar particle image velocimetry. The submerged jet was positioned at an offset height of 5d below the free surface, where d is the nozzle diameter. Measurements were conducted in both streamwise-surface-normal (x-y) and nine streamwise-spanwise (x-z) planes (−4 ≤ y/d ≤ 4) located in the far-field (x/d = 42–62) at an exit Reynolds number of 28 000. To highlight the effects of the free surface, measurements were also performed to evaluate the characteristics of a reference free jet at similar initial conditions. For each jet, the spanwise planes were used to reconstruct the three-dimensional (3D) averaged velocity field to reveal the salient flow features in the cross section of the jet. The reconstruction shows the presence of the well-known surface current, which is usually prominent in the far-field of surface jets. The spanwise development of the surface current is found to reduce the streamwise and spanwise Reynolds normal stresses in the upper shear layer of the surface jet, but the Reynolds shear stress and its associated dominant quadrant motions in the spanwise plane are enhanced near the free surface. As the free surface is approached, the spanwise spread rate increases, but the local vorticity thickness decreases due to the enhancement of the mean shear in the spanwise direction. Two-point spatial correlations are used to show that the large-scale structures near the free surface undergo oblique stretching in the spanwise plane to augment the wider spanwise growth of the surface current. The spatial distributions of the energetic modes based on proper orthogonal decomposition also reveal interesting features near the free surface that are consistent with the inclination of the turbulent structures relative to the flow direction.
Efficient quantum-dot light-emitting diodes using ZnS–AgInS2 solid-solution quantum dots in combination with organic charge-transport materials
Authors: Motomura Genichi , Ogura Kei , Kameyama Tatsuya , Torimoto Tsukasa , Uematsu Taro , Kuwabata Susumu , Tsuzuki Toshimitsu
Published: March 2020

Colloidal quantum dots (QDs), which exhibit highly saturated color emission, are expected to be used as emitting materials in wide-color-gamut displays. However, the development of low-toxicity alternatives is necessary because QDs with high color purity and highly efficient emission contain toxic materials such as Cd and Pb. In this study, QD light-emitting diodes (QD-LEDs) with ZnS–AgInS2 solid-solution nanoparticles [(AgIn)xZn2(1−x)S2, ZAIS] as low-toxicity QDs were fabricated and their electroluminescence properties were investigated. The ZAIS QDs exhibited red photoluminescence, with a peak wavelength of ca. 700 nm. Because the charge-injection barrier of ZAIS QDs without a wide-bandgap shell is relatively low, the QD-LEDs with red ZAIS QDs in combination with organic charge-transport materials induce electron injection from an organic electron-transport layer. These QD-LEDs exhibit an external quantum efficiency of 2.2%, a turn-on voltage of 2.4 V, and red emission with chromaticity coordinates (0.66, 0.33).
Multiscale coupled Maxwell’s equations and polarizable molecular dynamics simulation based on charge response kernel model
Authors: Yamada Atsushi
Published: March 2020

A computational scheme of coupled Maxwell’s equations and polarizable molecular dynamics simulation has been developed based on a multi-scale model to describe the coupled dynamics of light electromagnetic waves and molecules in crystalline solids, where the charge response kernel model is employed to incorporate electronic polarization of the molecules. The method is applicable to electronically non-resonant light–matter interaction systems that involve atomic motions in spectroscopy and photonics. Since the scheme simultaneously traces the light propagation in a medium on a macroscopic scale and the microscopic molecular motion under the light electric field, this enables us to treat the experimental setup and mimic its measurement process. As the first applications, we demonstrate three numerical examples of basic spectroscopies of an ice crystalline solid: simulations of reflection and transmission of visible light, infrared absorption measurement, and stimulated Raman scattering measurement. These examples show the detailed behaviors of the interacting light fields and molecules in the spectroscopic processes.
Temperature and pressure dependence of the alpha relaxation in ortho-terphenyl
Authors: Yungbluth Jack C. , Medvedev Grigori A. , Savoie Brett M. , Caruthers James M.
Published: March 2020

Molecular dynamics (MD) simulations of ortho-terphenyl using an all-atom model with the optimized potentials for liquid simulations (OPLS) force field were performed both in the high temperature Arrhenian region and at lower temperatures that include the onset of the super-Arrhenian region. From the MD simulations, the internal energy of both the equilibrium liquid and crystal was determined from 300 K to 600 K and at pressures from 0.1 MPa to 1 GPa. The translational and rotational diffusivities were also determined at these temperatures and pressures for the equilibrium liquid. It is shown that within a small offset, the excess internal energy Ūx from the MD simulations is consistent with the experimentally determined excess internal energy reported earlier [Caruthers and Medvedev, Phys. Rev. Mater. 2, 055604, (2018)]. The MD mobility data {including extremely long-time 1 atm simulations from the study by Eastwood et al. [J. Phys. Chem. B 117, 12898, (2013)]} were combined with experimental data to form a unified dataset, where it was shown that in both the high temperature Arrhenian region and the lower temperature super-Arrhenian region, the mobility is a linear function of 1/Ūx(T,p), albeit with different proportionality constants. The transition between the Arrhenian and super-Arrhenian regions is relatively sharp at a critical internal energy Ūxα. The 1/Ūx(T,p) model is able to describe the mobility data over nearly 16 orders-of-magnitude. Other excess thermodynamic properties such as excess enthalpy and excess entropy (i.e., the Adam–Gibbs model) are unable to unify the pressure dependence of the mobility.
Thermohaline convective instability in an inclined porous layer with permeable boundaries
Authors: Dubey Rashmi , Murthy P. V. S. N.
Published: March 2020

This study aims at investigating the onset of thermohaline convective instability in an inclined porous layer of finite width confined between two permeable boundaries. The instability in the flow is driven by the combined effect of temperature and solute concentration gradients acting vertically across the layer, and it depends on the angle of inclination at which that layer is inclined to the horizontal. This work complements previous studies on the double-diffusive convective instability by extensively discussing the effect of the solute concentration gradient for the case when the thermal and solutal buoyancy forces have comparable magnitudes and they act in the same and opposite directions. The investigation is illustrated by the results associated with the cases when the diffusivity ratio is thermally dominant, when the diffusivity ratio is thermally suppressed, and when the two components diffuse with the same intensity. A wide spectrum of the neutral stability curves are presented at different inclinations, which depict the instability in the basic state prevailing in the form of stationary and oscillatory modes. The neutral stability curves are seen to exhibit some exceptional behavior in the case when the thermal buoyancy and the solutal buoyancy act in the opposite directions. It is observed that the instability is always initiated by the non-traveling modes, except in the case when the thermal diffusivity is reasonably higher than the solutal diffusivity and when the two buoyant forces are acting in the opposite directions. The ratio of the two buoyant forces has an exceptionally non-monotonic impact on the instability, if considered in the vertical porous layer.
The EXP pair-potential system. IV. Isotherms, isochores, and isomorphs in the two crystalline phases
Authors: Bacher Andreas Kvist , Pedersen Ulf R. , Schrøder Thomas B. , Dyre Jeppe C.
Published: March 2020

This paper studies numerically the solid phase of a system of particles interacting by the exponentially repulsive pair potential, which is a face-centered cubic (fcc) crystal at low densities and a body-centered cubic (bcc) crystal at higher densities [U. R. Pedersen et al., J. Chem. Phys. 150, 174501 (2019)]. Structure is studied via the pair-distribution function and dynamics via the velocity autocorrelation function and the phonon density of states. These quantities are evaluated along isotherms, isochores, and three isomorphs in both crystal phases. Isomorphs are traced out by integrating the density-temperature relation characterizing configurational adiabats, starting from state points in the middle of the fcc-bcc coexistence region. Good isomorph invariance of structure and dynamics is seen in both crystal phases, which is notable in view of the large density variations studied. This is consistent with the fact that the virial potential-energy correlation coefficient is close to unity in the entire fcc phase and in most of the bcc phase (basically below the re-entrant density). Our findings confirm that the isomorph theory, developed and primarily studied for liquids, applies equally well for solids.
Efficient removal of antimony with natural secondary iron minerals: effect of structural properties and sorption mechanism
Authors: Wang Nana , Deng Nairui , Qiu Yuyin , Su Zebin , Huang Chujie , Hu Kaimei , Wang Jianqiao , Ma Liang , Xiao Enzong , Xiao Tangfu
Published: March 2020

Environmental contextAntimony is classified as a priority pollutant and is increasingly detected in the environment as a result of various anthropogenic activities. Natural secondary iron minerals are important sinks for many toxic elements. We found that antimony promotes structural transformations in secondary iron minerals, and that antimony is then further immobilised by the newly formed iron mineral phases.
AbstractSecondary iron minerals (SIMs), naturally formed in acid mine drainage (AMD), can serve as sinks to remove antimony (Sb) from the environment. In this study, we investigated the relationship between the structural characteristics and SbIII or SbV sorption behaviours of two different SIMs (neo-formed SIM (n-SIM) and mature SIM (m-SIM)). The results showed that both m- and n-SIMs were composed of mixed crystal phases, mainly schwertmannite, jarosite, goethite and ferrihydrite. Despite similar elemental compositions, they had different microstructures. m-SIM was a regular spheroid with a close-packed arrangement, while n-SIM was an incomplete irregular spheroid with ordered channels and a random loose arrangement. The initial SbIII or SbV sorption rate order was n-SIM>m-SIM. The maximum sorption capacities of n- and m-SIMs were 219.8 (SbIII) or 366.3 (SbV) mg g−1 and 160.3 (SbIII) or 114.9 (SbV) mg g−1 respectively, and n- and m-SIMs could both effectively remove Sb from natural wastewaters, while trace Sb levels remained. Sb immobilisation on SIMs occurred as a rapid endothermal and homogeneous sorption process. After Sb sorption, the SO42− and total Fe(aq) concentrations in the sample solutions significantly changed. X-ray diffraction (XRD) and Raman analyses confirmed that n- or m-SIM had transformed in the presence of Sb, even without FeII(aq), which indicated an important SIMs transformation-Sb immobilisation relationship. These findings are valuable for better understanding the Sb behaviours associated with natural SIMs and the short-term fate of Sb in the environment.
A revised circumscription for Siphonolejeunea and a new species from New Zealand
Authors: Renner Matt A. M. , de Lange Peter J.
Published: March 2020

A molecular phylogeny to test the monophyly of Nephelolejeunea by using previously published nrITS, rbcL and trnL–F sequence data demonstrated that Nephelolejeunea is paraphyletic with respect to Siphonolejeunea. Nephelolejeunea and Siphonolejeunea are, therefore, merged and, as the latter name has priority, new combinations in Siphonolejeunea are made for 10 species. The valid publication of the name Austrolejeunea is re-evaluated and we conclude that both Siphonolejeunea subgenus Austrolejeunea and Siphonolejeunea olgae were validly published in 1963. Siphonolejeunea bidentata is reported as new for New Zealand on the basis of a collection from the Wairarapa, a new species, Siphonolejeunea raharahanehemiae, is described on the basis of recent collections from Te Paki, where it grows on the twigs of Metrosideros bartlettii (Myrtaceae), and we provide a revised key to species of Siphonolejeunea. The significant conflict in signal between nrITS and chloroplast markers associated with the relationships of Cololejeunea angustiflora, which chloroplast sequence data suggest may not be grouped with the rest of Cololejeunea, is another interesting result from the phylogeny. The relationships of Cololejeunea angustiflora and its allies warrant further investigation.
Non-consensual sharing of personal sexually explicit imagery among young people in Australia: results from an online survey
Authors: Douglass Caitlin H. , Wright Cassandra J. C. , Davis Angela C. , Lim Megan S. C.
Published: March 2020

Consensual sharing of personal sexually explicit imagery (SEI) is part of young people’s sexual practise; however, harms arise if content is shared without consent. Australians aged 15–29 years were recruited for an online survey. Participants indicated if they had ever sent SEI of themselves to someone else, received SEI directly from the person in the imagery and whether they thought it was illegal to forward SEI without consent. Participants reported whether anyone shared their SEI without permission, if they told people, made official reports or if there were consequences for perpetrator(s). Logistic regression was used to identify associations between victimisation, gender, age group, sexual identity and knowledge of SEI-related law. In total, 1007 participants (65% female, mean age 23 years, 67% heterosexual) were recruited; 63% sent personal SEI to another person, 71% received SEI from the person pictured and 77% correctly identified it is illegal to forward SEI without consent. Thirteen percent (n = 126) indicated another person forwarded personal SEI without consent. In univariate analysis, victimisation was associated with identifying as non-heterosexual (odds ratio = 1.51, confidence interval = 1.03–2.22), but was independent from age group, gender and knowledge. In multivariate analysis, sexual identity, age group, gender and knowledge were not significantly associated with victimisation. Among participants who experienced non-consensual sharing of personal SEI, 63% told friends, 10% told family, 93% made no official report and 94% reported no consequences for perpetrator(s). Initiatives are needed to promote legal rights and enable young people to seek support.
Metabolic and genetic basis for auxotrophies in Gram-negative species
Authors: Seif Yara , Choudhary Kumari Sonal , Hefner Ying , Anand Amitesh , Yang Laurence , Palsson Bernhard O.
Published: March 2020

Auxotrophies constrain the interactions of bacteria with their environment, but are often difficult to identify. Here, we develop an algorithm (AuxoFind) using genome-scale metabolic reconstruction to predict auxotrophies and apply it to a series of available genome sequences of over 1,300 Gram-negative strains. We identify 54 auxotrophs, along with the corresponding metabolic and genetic basis, using a pangenome approach, and highlight auxotrophies conferring a fitness advantage in vivo. We show that the metabolic basis of auxotrophy is species-dependent and varies with 1) pathway structure, 2) enzyme promiscuity, and 3) network redundancy. Various levels of complexity constitute the genetic basis, including 1) deleterious single-nucleotide polymorphisms (SNPs), in-frame indels, and deletions; 2) single/multigene deletion; and 3) movement of mobile genetic elements (including prophages) combined with genomic rearrangements. Fourteen out of 19 predictions agree with experimental evidence, with the remaining cases highlighting shortcomings of sequencing, assembly, annotation, and reconstruction that prevent predictions of auxotrophies. We thus develop a framework to identify the metabolic and genetic basis for auxotrophies in Gram-negatives.