bluuebunny/crossref_metadata_2025 huggingface dataset:
Referenzwerte für die kardiorespiratorische Fitness der allgemeinen Bevölkerung: Die Studie zur Gesundheit Erwachsener in Deutschland (DEGS1) 2008–2011
Authors: Finger Jonas David , Banzer WinfriedE. , Baumeister Sebastian Edgar , Brandes Mirko , Bös Klaus , Gabrys Lars , Gößwald Antje , Härtel Sascha , Kluttig Alexander , Kuhnert Ronny , Leitzmann MichaelF. , Löllgen Herbert H. , Manz Kristin , Mensink GertB.M. , Niessner Claudia , Rosario Angelika Schaffrath , Kurth Bärbel-Maria
Published: November 2019

Ziel der Studie Das Ziel dieser Auswertung ist die Erstellung bundesweiter, bevölkerungsbezogener Referenzwerte für herzfrequenzbasierte Indikatoren der kardiorespiratorischen Fitness sporttauglicher Erwachsener im Alter von 18 bis 64 Jahren.

Methodik Auf der Datenbasis von 2826 Teilnehmenden des submaximalen Fahrradergometer-Tests in der „Studie zur Gesundheit Erwachsener in Deutschland“ (DEGS1) 2008–2011 wurden folgende körpergewichtsbezogene Indikatoren gebildet: Physical Working Capacity (herzfrequenzbezogene Leistung) bei 150 und 130 S/min, bei 75% der geschätzten maximalen Herzfrequenz (PWC130, PWC150 und PWC75%) sowie die herzfrequenzbasiert geschätzte maximale Sauerstoffaufnahme (VO2max). Die Referenzwerteberechnung erfolgte mit der LMS-Methode nach Cole & Green 1992.

Ergebnisse Das 25., 50. und 75. Perzentil der PWC150 liegt bei Männer bei 1,50, 1,77 und 2,08 Watt/kg. Die entsprechenden Werte bei Frauen sind 1,18, 1,44 und 1,69. Das 25., 50. und 75. Perzentil der PWC130 liegt bei Männer bei 1,16, 1,41 und 1,68 Watt/kg. Die entsprechenden Werte bei Frauen sind 0,81, 1,05 und 1,29. Die altersabhängigen Mediane bei Männern und Frauen sind für die PWC75% 1,87 – Alter in Jahren× 0,01 und 1,31 – (Alter in Jahren/100)2 x 0,98 und für die VO2max bei Männern 41,7 – Alter× 0,15.

Schlussfolgerung Die präsentierten Ergebnisse können als Referenzwerte für die Einschätzung der individuellen kardiorespiratorischen Fitness von in Deutschland lebenden Erwachsenen eingesetzt werden. Sie können außerdem als Basis für ein regelmäßiges Monitoring dienen.
Convenient One-Pot Synthesis of Allylsilanes from Enolizable Ketones
Authors: Kwan Man Lung D. , Challen Paul R. , Tran Quynh D.-D.
Published: November 2019

A convenient one-pot synthesis of allylsilanes from enolizable methyl aryl ketones has been developed. The first step involves nucleophilic addition of the trimethylsilylmethyl group to ketones using the alkylation method developed by Ishihara with slight modification to generate the corresponding β-silylalkoxides. The second step entails addition of diisobutylaluminum chloride and heating at about 130 °C overnight to afford allylsilanes in fair yields.
Synthesis of Biphenylenes and Their π-Extended Derivatives
Authors: Pan Ming-Lun , Wu Yao-Ting
Published: November 2019

A series of biphenylenes and their π-extended derivatives are easily prepared through tert-butyllithium-mediated cyclization of suitable halobiaryls and haloteraryls, respectively. The reactions proceed via the corresponding arynyl intermediates at low temperature (up to –20 °C).
Lewis Base Catalysis Based on Homoconjugate Addition: Rearrangement of Electron-Deficient Cyclopropanes and Their Derivatives
Authors: Babu Kaki Raveendra , He Xin , Xu Silong
Published: November 2019

Cyclopropane is one of the most reactive functionalities owing to its intrinsic ring strain. Transition-metal catalysis and Lewis acid catalysis have been extensively used in ring openings of cyclopropanes; however, Lewis base-catalyzed activation of cyclopropanes remains largely unexplored. Upon nucleophilic attack with Lewis bases, cyclopropanes undergo ring cleavage in a manner known as homoconjugate addition to form zwitterionic intermediates, which have significant potential for reaction development but have garnered little attention. Here, we present a brief overview of this area, with an emphasis on our recent efforts on Lewis base-catalyzed rearrangement reactions of electron-deficient cyclopropanes using the homoconjugate addition process.

1 Introduction

2 DABCO-Catalyzed Cloke–Wilson Rearrangement of Cyclopropyl Ketones

3 Hydroxylamine-Mediated Tandem Cloke–Wilson/Boulton–­Katritzky Reaction of Cyclopropyl Ketones

4 Phosphine-Catalyzed Rearrangement of Vinylcyclopropyl Ketones To Form Cycloheptenones

5 Phosphine-Catalyzed Rearrangement of Alkylidenecyclopropyl Ketones To Form Polysubstituted Furans and Dienones

6 Conclusion and Outlook
Overrating Classifier Performance in ROC Analysis in the Absence of a Test Set: Evidence from Simulation and Italian CARATkids Validation
Authors: Cilluffo Giovanna , Fasola Salvatore , Ferrante Giuliana , Montalbano Laura , Baiardini Ilaria , Indinnimeo Luciana , Viegi Giovanni , Fonseca Joao A. , La Grutta Stefania
Published: November 2019

Background The use of receiver operating characteristic curves, or “ROC analysis,” has become quite common in biomedical research to support decisions. However, sensitivity, specificity, and misclassification rates are still often estimated using the training sample, overlooking the risk of overrating the test performance.

Methods A simulation study was performed to highlight the inferential implications of splitting (or not) the dataset into training and test set. The normality assumption was made for the classifier given the disease status, and the Youden's criterion considered for the detection of the optimal cutoff. Then, an ROC analysis with sample split was applied to assess the discriminant validity of the Italian version of the Control of Allergic Rhinitis and Asthma Test (CARATkids) questionnaire for children with asthma and rhinitis, for which recent studies may have reported liberal performance estimates.

Results The simulation study showed that both single split and cross-validation (CV) provided unbiased estimators of sensitivity, specificity, and misclassification rate, therefore allowing computation of confidence intervals. For the Italian CARATkids questionnaire, the misclassification rate estimated by fivefold CV was 0.22, with 95% confidence interval 0.14 to 0.30, indicating an acceptable discriminant validity.

Conclusions Splitting into training and test set avoids overrating the test performance in ROC analysis. Validated through this method, the Italian CARATkids is valid for assessing disease control in children with asthma and rhinitis.
Weight-bearing MRI of the Lumbar Spine: Technical Aspects
Authors: Nordberg Cecilie Lerche , Hansen Bjarke Brandt , Nybing Janus Damm , Hansen Philip , Bliddal Henning , Griffith James F. , Fournier Gilles , Guglielmi Giuseppe , Boesen Mikael
Published: November 2019

Magnetic resonance imaging (MRI) has an established role in the assessment of degenerative musculoskeletal conditions. However, conventional supine MRI findings often correlate poorly with clinical findings. Some patients experience accentuated back pain in the weight-bearing position. Therefore, supine MRI may underestimate the severity of degenerative spine findings. To try and improve the clinical validity of spine imaging, axial loading devices have been used with conventional supine MR imaging to simulate loading of the upright spine. More recently, upright weight-bearing MRI systems (0.25–0.6 T) were introduced, allowing images to be obtained in the standing or seated weight-bearing position and even during upright flexion or extension, rotation, or bending. Some scanners even enable capturing of real-time spinal movement. This review addresses the technical aspects and potential challenges of weight-bearing MRI, both in clinical practice and research.
Weight-bearing MRI of the Lumbar Spine: Spinal Stenosis and Spondylolisthesis
Authors: Hansen Bjarke Brandt , Nordberg Cecilie Lerche , Hansen Philip , Bliddal Henning , Griffith James F. , Fournier Gilles , Thorseth Ingrid , Guglielmi Giuseppe , Boesen Mikael
Published: November 2019

Symptoms of degenerative lumbar spinal stenosis include back pain, radiculopathy, claudication, and muscular fatigue that tend to be predominant in the standing position or during walking. Lumbar spondylolisthesis is also a well-known cause of spinal stenosis, lateral recess, and neural foraminal narrowing that tends to become more severe in the upright position. This indicates a functional positional component of both spinal stenosis and spondylolisthesis. Lumbar spinal stenosis and spondylolisthesis are typically evaluated by magnetic resonance imaging (MRI) performed in the supine position with a pillow under the patient's lower limbs that slightly flexes the lumbar spine and ameliorates symptoms. Because these two entities tend to be aggravated in the upright position, it seems rational to also consider performing diagnostic imaging in these patients in the upright position. This article reviews the use of weight-bearing MRI for lumbar spinal stenosis and spondylolisthesis.
Weight-bearing CT Technology in Musculoskeletal Pathologies of the Lower Limbs: Techniques, Initial Applications, and Preliminary Combinations with Gait-Analysis Measurements at the Istituto Ortopedico Rizzoli
Authors: Leardini Alberto , Durante Stefano , Belvedere Claudio , Caravaggi Paolo , Carrara Claudio , Berti Lisa , Lullini Giada , Giacomozzi Claudia , Durastanti Gilda , Ortolani Maurizio , Guglielmi Giuseppe , Bazzocchi Alberto
Published: November 2019

Musculoskeletal radiology has been mostly limited by the option between imaging under load but in two dimensions (i.e., radiographs) and three-dimensional (3D) scans but in unloaded conditions (i.e., computed tomography [CT] and magnetic resonance imaging in a supine position). Cone-beam technology is now also a way to image the extremities with 3D and weight-bearing CT. This article discusses the initial experience over a few studies in progress at an orthopaedic center. The custom design of total ankle replacements, the patellofemoral alignment after medial ligament reconstruction, the overall architecture of the foot bones in the diabetic foot, and the radiographic assessment of the rearfoot after subtalar fusion for correction of severe flat foot have all taken advantage of the 3D and weight-bearing feature of relevant CT scans. To further support these novel assessments, techniques have been developed to obtain 3D models of the bones from the scans and to merge these with state-of-the-art gait analyses.
Weight-bearing MR Imaging of Knee, Ankle and Foot
Authors: Bruno Federico , Arrigoni Francesco , Palumbo Pierpaolo , Natella Raffaele , Splendiani Alessandra , Di Cesare Ernesto , Guglielmi Giuseppe , Masciocchi Carlo , Barile Antonio
Published: November 2019

Clinical management of several pathologies of the lower extremity joint relies on instrumental imaging evaluation. The assessment of joint changes with physiologic load requires studies using positions with the patient standing. Weight-bearing radiographs are the mainstay for the evaluation of several conditions such as knee osteoarthritis, pes planus, and hallux valgus, in particular to obtain measurements of articular parameters, especially for presurgical studies. In the last few years, dedicated magnetic resonance imaging and computed tomography scanners have also been developed to obtain high-resolution, multiplanar, and sectional images of the lower extremity joints during weight-bearing. These techniques provide detailed information on joint structure modifications under load in both physiologic and pathologic conditions to improve the diagnostic accuracy of weight-bearing studies.
Weight-bearing Magnetic Resonance Imaging of the Cervical Spine
Authors: Lee Ryan Ka Lok , Griffith James F.
Published: November 2019

The cervical spine is subject to the effect of gravity in the upright position. Weight-bearing upright magnetic resonance imaging (MRI) potentially allows a better diagnosis and evaluation of cervical spine pathology that may be masked or not fully appreciated in the usual non–weight-bearing supine position. Only limited studies are currently available in this area. This article summarizes the current literature on weight-bearing MRI of the cervical spine.
Fever in the Neurointensive Care Unit
Authors: Chavali Siddharth , Tripathi Manjari , Rajagopalan Vanitha
Published: November 2019

Fever occurs commonly in patients admitted to the neurocritical care unit. An increase in the body temperature is known to have deleterious effects on patients with acute nervous system injury and in most cases is associated with an increase in mortality and morbidity of these patients. There are multiple causes of fever in these patients. Due to the potentially devastating effects of fever in patients with cerebral diseases, it warrants treatment in every case. In all patients with acute cerebral damage, treatment of fever and maintenance of euthermia is important to obtain a better functional recovery and to limit any further secondary insult to the brain. This review highlights the etiology and pathophysiology of fever in neurocritical care unit patients, the effects on various organ systems and associated systemic complications, and the evaluation and different therapeutic options available for the management of fever in this patient subset.
Recomendaciones para optimizar el éxito en reimplante de dedos
Authors: Landin-Jarillo Luis , Gonzalez-Peinado David , Alonso-Sanz Javier , Villar-Yus Carlos , Casado-Sanchez Cesar
Published: November 2019

Los traumatismos con amputación o desvascularización de los dedos de la mano son lesiones complejas que precisan la derivación a unidades de referencia. El objetivo del reimplante es un resultado funcional y estético, y depende del traumatismo, del paciente y del cirujano. El éxito observado en reimplantes y revascularizaciones ha alcanzado el 89,5% en nuestra serie de 130 pacientes entre los años 2006 y 2019. La valoración inicial del paciente y de la parte amputada tienen repercusión directa en la indicación y el resultado final del reimplante. El desempeño de las técnicas de microcirugía es esencial para el éxito del procedimiento. En esta revisión, damos a conocer los diagnósticos prácticos así como la secuencia para la ejecución del reimplante desde antes de la llegada del paciente a quirófano, y proponemos una serie de detalles técnicos para ayudar al lector a conseguir el éxito de sus reimplantes.
Fracturas de Fémur Proximal de Alta Energía Tratadas con Reducción a Través de Mini-open y Clavo Cefalo-medular
Authors: Villalón Ignacio E. , Cancino Jaime , Vigueras Cristóbal , Contesse Iván , Piriz Julio , del Río Javier
Published: November 2019

Objetivo Evaluar los resultados radiológicos de pacientes con fractura de fémur proximal tratados con clavo cefalo-medular y reducción abierta a través de abordaje mini-open.

Material y Métodos Estudio retrospectivo-descriptivo de una serie consecutiva de 45 pacientes (38 hombres, 7 mujeres, edad promedio 52 años) con fractura de cadera de alta energía tratados con clavo cefalo-medular y reducción a través de abordaje mini-open. Se registró el mecanismo del accidente y presencia de lesiones asociadas. En todos los casos se contó con radiografías preoperatorias y tomografía axial computada (TAC). Se clasificaron de acuerdo a la AO. Se registró en número de fragmentos que presentaba la fractura. Se tomaron radiografías de control en forma mensual hasta la consolidación. Se midió el ángulo cervico-diafisiario operado y contralateral.

Resultados Todos los casos fueron secundarios a un accidente de alta energía. Veintidós pacientes presentaron lesiones asociadas. El número de fragmentos promedio fue de 3. La diferencia entre el ángulo cervico-diafisiario post operatorio de la cadera fracturada versus la cadera contralateral fue de 4,9 grados. Un paciente presentó no-unión. El tiempo promedio hasta la consolidación radiográfica fue de 3,7 meses.

Conclusión El uso de clavos cefalo-medulares asociado a reducción a través de mini-open en pacientes jóvenes con fractura de fémur proximal de alta energía, presenta buenos resultados radiológicos con bajo número de complicaciones.
Association of Vitamin D Insufficiency and Peripheral Vascular Resistance
Authors: Kumar Goud Chukkala Bharat , Garre Indrani , Radhika S.
Published: November 2019

Background Vitamin D insufficiency is prevalent worldwide. Recently, the role of vitamin D substitution in hypertensive vitamin D deficient and insufficient patients has been studied by many investigators worldwide. In this observational study, the peripheral vascular resistance (PVR) of patients with vitamin D insufficiency or deficiency was analyzed.

Objective The main purpose of this article is the assessment of PVR in vitamin D deficient subjects and in that any gender variation.

Methods Subjects who were not known hypertensives, and who were free of other comorbidities, were included. Diabetic subjects were excluded. Serum vitamin D3 levels of all the subjects were recorded. Thirty-three subjects with serum vitamin D3 levels in insufficiency or deficiency range were included in our study. AGEDIO peripheral resistance calculator was used to calculate arterial stiffness indices, PVR, stroke volume, cardiac output, and cardiac index. Augmentation pressure (AG) is the contribution that wave reflection makes to systolic arterial pressure. Augmentation index (AI) is an indirect measure of arterial stiffness and is calculated as AG divided by pulse pressure ×100.

Results The total number of subjects studied was 33, of whom 18 were males, and 15 were females. The mean serum vitamin D3 levels were 19.28 nanograms/mL. In this study, it was observed that the mean AI was 21.42 ± 12.6%, and mean pulse wave velocity was 6.9 ± 1.2 m/s. Among central hemodynamic measures, mean PVR was found to be 1733 ± 201.1dyn*s/cm5, mean cardiac output was 4.3 ± 0.5 L/min, and mean cardiac index was 2.56 +/– 0.33 L/mi*L/m2). Twenty-five (76%) patients showed increased PVR. Even though in patients with normal PVR, there is female preponderance, but in patients with high PVR, there was no gender difference.

Conclusions This study has shown that the PVR was significantly high in vitamin D deficient and insufficient subjects (without hypertension or diabetes mellitus) with no significant gender difference for high PVR, even though AG and AI were not significantly different among subjects.
The Nehari manifold for a class of Schrödinger equation involving fractional p-Laplacian and sign-changing logarithmic nonlinearity
Authors: Truong Le Xuan
Published: November 2019

In this paper, we study the Schrödinger equation involving fractional p-Laplacian on the whole space of the form (−Δ)psu+V(x)|u|p−2u=λK(x)|u|p−2u+μQ(x)|u|p−2u⁡log|u|, with the sign-changing weight function Q and the possibly vanishing potential V. By using the relationship between fibering maps and the Nehari manifold, we obtain the existence of at least two nontrivial solutions.
What should the density of amorphous solids be?
Authors: Cui Xiang-Yuan , Ringer Simon P. , Wang Gang , Stachurski Z. H.
Published: November 2019

A survey of published literature reveals a difference in the density of amorphous and crystalline solids (organic and inorganic) on the order of 10%–15%, whereas for metallic alloys, it is found to be typically less than 5%. Standard geometric models of atomic packing can account for the polymeric and inorganic glasses without requiring changes in interatomic separations (bond lengths). By contrast, the relatively small difference in density between crystalline and glassy metals (and metallic alloys) implies variations in interatomic separations due to merging orbitals giving rise to reduced atomic volumes. To test this hypothesis, quantum density functional theory computations were carried out on ordered and irregular clusters of aluminum. The results point to decreasing interatomic distances with decreasing coordination, from which one can deduce that the geometrical method of random hard sphere packing significantly underestimates the densities of amorphous metallic alloys.
Higher-order harmonic generation of laser radiation due to relativistic plasma resonance at nonrelativistic laser intensity
Authors: Metelskii I. I. , Kovalev V. F. , Bychenkov V. Yu.
Published: November 2019

The well-known plasma resonance (transformation into plasma waves) at a critical density in an inhomogeneous plasma easily becomes relativistic nonlinear even at nonrelativistic laser intensities because the generated electrostatic field is significantly increased. Therefore, the widely used theory of harmonic generation by plasma resonance in a laser-produced plasma should be re-examined. We formulate the corresponding analytical theory of higher-order harmonic generation by nonrelativistic intense laser radiation propagating in a spatially inhomogeneous plasma. We find the spectral and angular characteristics of the harmonic radiation field and demonstrate the role of relativistic nonlinearity at plasma resonance in forming the harmonic spectra. The applicability range of the developed theory is determined by the plasma wave-breaking condition in the vicinity of the critical plasma density, which we analyze explicitly. The proposed theory is compared with the standard perturbation approach. Because the latter corresponds to low laser intensities, this comparison clearly shows the failure of the theory of harmonic generation via linear plasma resonance. The presented relativistic theory, which is applicable up to the laser intensity corresponding to plasma wave breaking, demonstrates the formation of a smooth power-law energy spectrum of higher-order laser harmonics in contrast to the standard perturbation theory. A spectral modulation of harmonics is also shown, which is a unique feature of relativistic nonlinearity.
ChaosNet: A chaos based artificial neural network architecture for classification
Authors: Balakrishnan Harikrishnan Nellippallil , Kathpalia Aditi , Saha Snehanshu , Nagaraj Nithin
Published: November 2019

Inspired by chaotic firing of neurons in the brain, we propose ChaosNet—a novel chaos based artificial neural network architecture for classification tasks. ChaosNet is built using layers of neurons, each of which is a 1D chaotic map known as the Generalized Luröth Series (GLS) that has been shown in earlier works to possess very useful properties for compression, cryptography, and for computing XOR and other logical operations. In this work, we design a novel learning algorithm on ChaosNet that exploits the topological transitivity property of the chaotic GLS neurons. The proposed learning algorithm gives consistently good performance accuracy in a number of classification tasks on well known publicly available datasets with very limited training samples. Even with as low as seven (or fewer) training samples/class (which accounts for less than 0.05% of the total available data), ChaosNet yields performance accuracies in the range of 73.89%−98.33%. We demonstrate the robustness of ChaosNet to additive parameter noise and also provide an example implementation of a two layer ChaosNet for enhancing classification accuracy. We envisage the development of several other novel learning algorithms on ChaosNet in the near future.
Optimization of Seebeck coefficients of strain-symmetrized semiconductor heterostructures
Authors: Proshchenko Vitaly S. , Settipalli Manoj , Neogi Sanghamitra
Published: November 2019

A nonmonotonic thermopower (S) as a function of the carrier concentration (ne) has been reported for III–V semiconductor superlattices (SLs), deviating from the Pisarenko relation. However, |S| has been shown to decrease with increasing ne in n-type Si/Ge heterostructures, the widely used systems for numerous applications. Here, we illustrate that S of a SinGem SL, with n Si and m Ge monolayers, can deviate from the Pisarenko relation depending on the period and the composition; for example, oscillations of S of a Si12Ge12 SL reach a peak |S|=540 μV/K at ne=1.3×1020 cm−3, 5.4 times higher than that of bulk Si at the same doping level. Additionally, S shows an interesting sign-change nature at certain carrier concentrations. We demonstrate the direct relationship between the electronic structure and S of strain-symmetrized Si/Ge SLs using two independent modeling approaches. We anticipate that this relationship will provide insight into fully exploiting S as a tool to control electronic properties of Si/Ge heterostructures as well as future technology-enabling materials. Furthermore, we expect that this analysis will encourage future investigations to enhance thermoelectric properties of a broad class of semiconductor SLs in the high-doping regime.
Epitaxial κ-(AlxGa1−x)2O3 thin films and heterostructures grown by tin-assisted VCCS-PLD
Authors: Storm P. , Kneiß M. , Hassa A. , Schultz T. , Splith D. , von Wenckstern H. , Koch N. , Lorenz M. , Grundmann M.
Published: November 2019

The structural, surface, and optical properties of phase-pure κ-(AlxGa1−x)2O3 thin films on c-sapphire and STO(111):Nb substrates as well as on MgO(111) and κ-Ga2O3 templates are reported as a function of alloy composition for x < 0.4. The thin films were grown by tin-assisted pulsed laser deposition (PLD). For the variation of the Al-content, we utilized radially segmented PLD targets that enable the deposition of a thin film material library by discrete composition screening. Growth on κ-Ga2O3 (001) thin film templates enhanced the phase pure growth window remarkably up to x = 0.65. The crystallization of the κ-phase was verified by X-ray diffraction 2θ-ω-scans for all samples. Both in- and out-of-plane lattice constants in dependence on the Al-content follow a linear relationship according to Vegard’s law over the complete composition range. Atomic force microscope measurements confirm smooth surfaces (Rq ≈ 1.4 nm) for all investigated Al-contents. Furthermore, bandgap tuning from 4.9 eV to 5.8 eV is demonstrated and a linear increase in the bandgap with increasing Al-content was observed.
Numerical study of total temperature effect on hypersonic boundary layer transition
Authors: Zhao Jinshan , Liu Sen , Zhao Lei , Zhang Zhigang
Published: November 2019

The total temperature in the hypersonic wind tunnel test can be significantly different from that in real flight conditions, and this leads to a large discrepancy in the measurement of the boundary layer transition between ground experiment measurements and flight tests. Even at the same Mach number and Reynolds number, different wind tunnels may yield different transition data for the same model due to the total temperature effect. In this paper, the boundary layer transition on a 7° half-angle sharp cone (at a 0° angle of attack) with four freestream total temperatures is investigated using both the simulations of a local correlation-based transition model and linear stability analysis. The results show that as the freestream total temperature increases, the starting point of the transition on the sharp cone gradually moves backward and the length of the transition region decreases. The N factor of the unstable wave gradually decreases with increasing freestream total temperature, causing the transition onset to move backward. The total temperature effects on boundary transition as determined by both methods of analysis were in good agreement.
Effect of bolus viscosity on carbohydrate digestion and glucose absorption processes: An in vitro study
Authors: Karthikeyan J. S. , Salvi Deepti , Corradini Maria G. , Ludescher Richard D. , Karwe Mukund V.
Published: November 2019

Digestion is the process of breaking down food into smaller nutrient components which can be easily absorbed in the intestinal tract. The aim of this study was to experimentally investigate the influence of bolus (gastric content) viscosity on digestion and nutrient absorption processes, using an in vitro gastrointestinal model, the TIM-1 system. Two types of simple carbohydrates, namely, glucose and maltodextrin, were used as model foods. The initial bolus viscosity was varied (∼1 mPa·s, ∼15 mPa·s, and ∼100 mPa·s) using different glycerol-water proportions. A fluorescent molecular rotor compound (Fast Green For Coloring Food) was used to monitor viscosity changing patterns of the gastrointestinal content during digestion in the in vitro stomach and small intestinal sections. The digested-nutrient absorption data indicated that the initial bolus viscosity did not significantly affect the glucose absorption process in the small intestine. However, an increase in the initial bolus viscosity from ∼1 mPa·s to ∼15 mPa·s reduced the maltodextrin to glucose conversion by 35%. A further increase in the initial bolus viscosity from ∼15 mPa·s to ∼100 mPa·s did not significantly reduce the maltodextrin to glucose conversion.
Human stroma and epithelium co-culture in a microfluidic model of a human prostate gland
Authors: Jiang L. , Ivich F. , Tahsin S. , Tran M. , Frank S. B. , Miranti C. K. , Zohar Y.
Published: November 2019

The prostate is a walnut-sized gland that surrounds the urethra of males at the base of the bladder comprising a muscular portion, which controls the release of urine, and a glandular portion, which secretes fluids that nourish and protect sperms. Here, we report the development of a microfluidic-based model of a human prostate gland. The polydimethylsiloxane (PDMS) microfluidic device, consisting of two stacked microchannels separated by a polyester porous membrane, enables long-term in vitro cocultivation of human epithelial and stromal cells. The porous separation membrane provides an anchoring scaffold for long-term culturing of the two cell types on its opposite surfaces allowing paracrine signaling but not cell crossing between the two channels. The microfluidic device is transparent enabling high resolution bright-field and fluorescence imaging. Within this coculture model of a human epithelium/stroma interface, we simulated the functional development of the in vivo human prostate gland. We observed the successful differentiation of basal epithelial cells into luminal secretory cells determined biochemically by immunostaining with known differentiation biomarkers, particularly androgen receptor expression. We also observed morphological changes where glandlike mounds appeared with relatively empty centers reminiscent of prostatic glandular acini structures. This prostate-on-a-chip will facilitate the direct evaluation of paracrine and endocrine cross talk between these two cell types as well as studies associated with normal vs disease-related events such as prostate cancer.
Production of intense uranium beams with inductive heating oven at Institute of Modern Physics
Authors: Lu W. , Sun L. T. , Qian C. , Li L. B. , Guo J. W. , Huang W. , Zhang X. Z. , Zhao H. W.
Published: November 2019

HIAF (High Intensity heavy ion Accelerator Facility) is a new accelerator complex under construction at the Institute of Modern Physics. As the main injector of this project, the high-charge-state ECR ion source needs to provide intense uranium beams, such as 700 eμA of U35+. This requires the performance of metal ovens to be further improved so that the crucible can operate at an ultrahigh temperature for a long time without damage in a high magnetic field (>3 T). In order to meet these requirements, an inductive oven with special thermal shielding and support has been developed in the past two years. The off-line test result has shown that this oven can reach up to 2000 °C with ∼1.2 kW of heating power. After ∼5 days of continuous running on the SECRAL-II platform, the tantalum crucible survived. In this contribution, we will discuss the structure of this inductive oven and analyze the test results as well.
Longing for a national container. On the symbolic economy of Europe's new nationalism
Authors: Kraemer Klaus
Published: November 2019

This paper discusses how to explain the rise of a new nationalism in Europe. It begins by problematizing the inconsistencies in the current culturalist, socio-economic, and socio-political approaches. It then makes Pierre Bourdieu's theory of social space fruitful for a sociological explanation of neonationalism by removing it from the conceptional framework of national container societies. It finally shows that the transnational opening of national societies is accompanied by profound processes of symbolic appreciation and depreciation of economic, cultural, and social ‘capital’ that the inhabitants of the national container possess.
B cells are sufficient to prime the dominant CD4+ Tfh response to Plasmodium infection
Authors: Arroyo E. Nicole , Pepper Marion
Published: November 2019

CD4+ T follicular helper (Tfh) cells dominate the acute response to a blood-stage Plasmodium infection and provide signals to direct B cell differentiation and protective antibody expression. We studied antigen-specific CD4+ Tfh cells responding to Plasmodium infection in order to understand the generation and maintenance of the Tfh response. We discovered that a dominant, phenotypically stable, CXCR5+ Tfh population emerges within the first 4 d of infection and results in a CXCR5+ CCR7+ Tfh/central memory T cell response that persists well after parasite clearance. We also found that CD4+ T cell priming by B cells was both necessary and sufficient to generate this Tfh-dominant response, whereas priming by conventional dendritic cells was dispensable. This study provides important insights into the development of CD4+ Tfh cells during Plasmodium infection and highlights the heterogeneity of antigen-presenting cells involved in CD4+ T cell priming.
Vortex dynamics controlled by local superconducting enhancement
Authors: Rollano V , Gomez A , Muñoz-Noval A , del Valle J , Menghini M , de Ory M C , Prieto J L , Navarro E , Gonzalez E M , Vicent J L
Published: November 2019

A controlled local enhancement of superconductivity yields unexpected modifications in the vortex dynamics. This local enhancement has been achieved by designing an array of superconducting Nb nanostructures embedded in a V superconducting film. The most remarkable findings are: (i) vanishing of the main commensurability effect between the vortex lattice and the array unit cell, (ii) hysteretic behavior in the vortex dynamics, (iii) broadening of the vortex liquid phase and (iv) strong softening of the vortex lattice. These effects can be controlled and they can be quenched by reducing the Nb array superconducting performance applying an in-plane magnetic field. These results can be explained by taking into account the repulsive potential landscape created by the superconducting Nb nanostructures on which vortices move.
Improvement of radiative recombination rate in deep ultraviolet laser diodes with step-like quantum barrier and aluminum-content graded electron blocking layer*
Authors: Wang Yi-Fu , Niass Mussaab I , Wang Fang , Liu Yu-Huai
Published: November 2019

The design of the active region structures, including the modifications of structures of the quantum barrier (QB) and electron blocking layer (EBL), in the deep ultraviolet (DUV) AlGaN laser diode (LD) is investigated numerically with the Crosslight software. The analyses focus on electron and hole injection efficiency, electron leakage, hole diffusion, and radiative recombination rate. Compared with the reference QB structure, the step-like QB structure provides high radiative recombination and maximum output power. Subsequently, a comparative study is conducted on the performance characteristics with four different EBLs. For the EBL with different Al mole fraction layers, the higher Al-content AlGaN EBL layer is located closely to the active region, leading the electron current leakage to lower, the carrier injection efficiency to increase, and the radiative recombination rate to improve.
Fluctuation theorem for entropy production at strong coupling*
Authors: Xu Y Y , Liu J , Feng M
Published: November 2019

Fluctuation theorems have been applied successfully to any system away from thermal equilibrium, which are helpful for understanding the thermodynamic state evolution. We investigate fluctuation theorems for strong coupling between a system and its reservoir, by path-dependent definition of work and heat satisfying the first law of thermodynamics. We present the fluctuation theorems for two kinds of entropy productions. One is the informational entropy production, which is always non-negative and can be employed in either strong or weak coupling systems. The other is the thermodynamic entropy production, which differs from the informational entropy production at strong coupling by the effects regarding the reservoir. We find that, it is the negative work on the reservoir, rather than the nonequilibrium of the thermal reservoir, which invalidates the thermodynamic entropy production at strong coupling. Our results indicate that the effects from the reservoir are essential to understanding thermodynamic processes at strong coupling.
First-principles study of high performance lithium/sodium storage of Ti3C2T2 nanosheets as electrode materials*
Authors: Bai Li-Na , Kong Ling-Ying , Wen Jing , Ma Ning , Gao Hong , Zhang Xi-Tian
Published: November 2019

Ti3C2
Tx
nanosheet, the first synthesized MXene with high capacity performance and charge/discharge rate, has attracted increasingly attention in renewable energy storage applications. By performing systematic density functional theory calculations, the theoretical capacity of the intrinsic structure of single- and multi-layered Ti3C2
T
2 (T = F or O) corresponding to M (M = Li and Na) atoms are investigated. Theoretical volumetric capacity and gravimetric capacity are obtained, which are related to the stacking degree. The optimal ratios of capacity to structure are determined under different stacking degrees for understanding the influence of surface functional groups on energy storage performance. Its performance can be tuned by performing surface modification and increasing the interlayer distance. In addition, the reason for theoretical capacity differences of M atoms is analyzed, which is attributed to difference in interaction between the M-ions and substrate and the difference in electrostatic exclusion between adsorbed M-ions. These results provide an insight into the understanding of the method of efficiently increasing the energy storage performance, which will be useful for designing and using high performance electrode materials.
Growth characteristics of type IIa large single crystal diamond with Ti/Cu as nitrogen getter in FeNi–C system*
Authors: Guo Ming-Ming , Li Shang-Sheng , Hu Mei-Hua , Su Tai-Chao , Wang Jun-Zuo , Gao Guang-Jin , You Yue , Nie Yuan
Published: November 2019

High-quality type IIa large diamond crystals are synthesized with Ti/Cu as nitrogen getter doped in an FeNi–C system at temperature ranging from 1230 °C to 1380 °C and at pressure 5.3–5.9 GPa by temperature gradient method. Different ratios of Ti/Cu are added to the FeNi–C system to investigate the best ratio for high-quality type IIa diamond. Then, the different content of nitrogen getter Ti/Cu (Ti : Cu = 4 : 3) is added to this synthesis system to explore the effect on diamond growth. The macro and micro morphologies of synthesized diamonds with Ti/Cu added, whose nitrogen concentration is determined by Fourier transform infrared (FTIR), are analyzed by optical microscopy (OM) and scanning electron microscopy (SEM), respectively. It is found that the inclusions in the obtained crystals are minimal when the Ti/Cu ratio is 4:3. Furthermore, the temperature interval for diamond growth becomes narrower when using Ti as the nitrogen getter. Moreover, the lower edge of the synthesis temperature of type IIa diamond is 25 °C higher than that of type Ib diamond. With the increase of the content of Ti/Cu (Ti : Cu = 4 : 3), the color of the synthesized crystals changes from yellow and light yellow to colorless. When the Ti/Cu content is 1.7 wt%, the nitrogen concentration of the crystal is less than 1 ppm. The SEM results show that the synthesized crystals are mainly composed by (111) and (100) surfaces, including (311) surface, when the nitrogen getter is added into the synthesis system. At the same time, there are triangular pits and dendritic growth stripes on the crystal surface. This work will contribute to the further research and development of high-quality type IIa diamond.
A novel particle tracking velocimetry method for complex granular flow field*
Authors: Wang Bi-De , Song Jian , Li Ran , Han Ren , Zheng Gang , Yang Hui
Published: November 2019

Particle tracking velocimetry (PTV) is one of the most commonly applied granular flow velocity measurement methods. However, traditional PTV methods may have issues such as high mismatching rates and a narrow measurement range when measuring granular flows with large bulk density and high-speed contrast. In this study, a novel PTV method is introduced to solve these problems using an optical flow matching algorithm with two further processing steps. The first step involves displacement correction, which is used to solve the mismatching problem in the case of high stacking density. The other step is trajectory splicing, which is used to solve the problem of a measurement range reduction in the case of high-speed contrast The hopper flow experimental results demonstrate superior performance of this proposed method in controlling the number of mismatched particles and better measuring efficiency in comparison with the traditional PTV method.
Landau-like quantized levels of neutral atom induced by a dark-soliton shaped electric field*
Authors: Wang Yueming , Jin Zhen
Published: November 2019

Motivated by the fascinating progresses in the cold atom experiments and theories, especially the artificial gauge field induced spin–orbit coupling of neutral atoms, we present a novel dispersion of neutral atoms carrying a non-vanishing magnetic moment in a special gauge field, an external electric field of dark-soliton shaped profile. By means of WKB approximation, we obtain discrete quantized landau-like energy levels, which is instructive for the quantum Hall effect of neutral particles. The observability of the results is also discussed.
Microfluidic temperature sensor based on temperature-dependent dielectric property of liquid*
Authors: Liu Qi , Yu Yu-Feng , Zhao Wen-Sheng , Li Hui
Published: November 2019

We propose a low-cost compact microfluidic temperature sensor by virtue of the temperature-dependent permittivity of liquid. The sensor is composed of a coplanar waveguide (CPW) transmission line loaded with three resonators and a microfluidic plate with three channels. The resonant frequency of each resonator relies on the temperature-dependent dielectric property of liquid in corresponding channel, which therefore can be used to extract the temperature. The proposed sensor features a compact size and low cost since it requires only micro fluid volume instead of additional electronic components to produce significant frequency shift with changing temperature. Moreover, it exhibits decent accuracy and stability in a temperature sensing range from 30 °C to 95 °C. A theoretical analysis of the sensor is provided, followed by the detailed characterization method, and a prototype is designed, manufactured, and measured to verify the theoretical analysis.
Sound propagation in inhomogeneous waveguides with sound-speed profiles using the multimodal admittance method
Authors: Li Qi , Liu Juan , Guo Wei
Published: November 2019

The multimodal admittance method and its improvement are presented to deal with various aspects in underwater acoustics, mostly for the sound propagation in inhomogeneous waveguides with sound-speed profiles, arbitrary-shaped liquid-like scatterers, and range-dependent environments. In all cases, the propagation problem governed by the Helmholtz equation is transformed into initial value problems of two coupled first-order evolution equations with respect to the modal components of field quantities (sound pressure and its derivative), by projecting the Helmholtz equation on a constructed orthogonal and complete local basis. The admittance matrix, which is the modal representation of Direchlet-to-Neumann operator, is introduced to compute the first-order evolution equations with no numerical instability caused by evanescent modes. The fourth-order Magnus scheme is used for the numerical integration of differential equations in the numerical implementation. The numerical experiments of sound field in underwater inhomogeneous waveguides generated by point sources are performed. Besides, the numerical results computed by simulation software COMSOL Multiphysics are given to validate the correction of the multimodal admittance method. It is shown that the multimodal admittance method is an efficient and stable numerical method to solve the wave propagation problem in inhomogeneous underwater waveguides with sound-speed profiles, liquid-like scatterers, and range-dependent environments. The extension of the method to more complicated waveguides such as horizontally stratified waveguides is available.
Phase transition of DNA compaction in confined space: Effects of macromolecular crowding are dominant*
Authors: Chen Erkun , Fan Yangtao , Zhao Guangju , Mao Zongliang , Zhou Haiping , Liu Yanhui
Published: November 2019

With a view of detecting the effects of macromolecular crowding on the phase transition of DNA compaction confined in spherical space, Monte Carlo simulations of DNA compaction in free space, in confined spherical space without crowders and in confined spherical space with crowders were performed separately. The simulation results indicate that macromolecular crowding effects on DNA compaction are dominant over the roles of multivalent counterions. In addition, effects of temperature on the phase transition of DNA compaction have been identified in confined spherical space with different radii. In confined spherical space without crowders, the temperature corresponding to phase transition depends on the radius of the confined spherical space linearly. In contrast, with the addition of crowders to the confined spherical space, effects of temperature on the phase transition of DNA compaction become insignificant, whereas the phase transition at different temperatures strongly depends on the size of crowder, and the critical volume fraction of crowders pertains to the diameter of crowder linearly.
Anisotropy of turbulent fluctuations of velocity and third-order moments in the near wake of a circular cylinder
Authors: Molochnikov V M , Mikheev N I , Mikheev A N , Saushin I I
Published: November 2019

Turbulent structure of the near wake behind a circular cylinder in a cross flow at Re = 3900 was studied experimentally. Instantaneous velocity vector fields in the wake were measured using Smoke Image Velocimetry (SIV). The profiles of velocity components, their RMS fluctuations and Reynolds stresses were compared with direct numerical simulation and experimental data obtained by other authors. The anisotropy of turbulent fluctuations in different zones of the wake was analyzed. Third-order moments of velocity fluctuations in the near wake behind the cylinder were measured for the first time ever.
Stability of axisymmetric supersonic submerged microjet of nonequilibrium sulphur hexafluoride
Authors: Tsyryulnikov I S , Aniskin V M , Mironov S G
Published: November 2019

The influence of vibrational excitation and relaxation of molecules of gaseous sulphur hexafluoride (SF6) on the gas-dynamic structure and stability of high-velocity microjets flowing out of axisymmetric convergent micronozzles is studied numerically. The present numerical simulations are performed with allowance for vibrational relaxation of molecules with the use of a two-temperature model of relaxing flows by means of solving unsteady Navier-Stokes equations in a 3D formulation. The effects of vibrational relaxation of gas molecules on the gas-dynamic structure, intensity of disturbances, and length of the supersonic core of microjets are considered.
Influence of streamwise vortical structures on heat transfer in the far cylinder wake in a slot channel flow
Authors: Palkin E , Mullyadzhanov R
Published: November 2019

We report on Large-eddy simulations (LES) of a flow around a cylinder in a narrow duct channel (slot) at the Reynolds number 3750 based on the bulk velocity and the diameter of the cylinder. Secondary streamwise vortical structures in the far wake are investigated appearing near the mixing layer at the midplane and near the duct channel surface. We investigate the correlation between the heat flux and friction velocity fluctuations and evaluate the propagation speed of these disturbances, which appears to be different.