bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental study on the evaporating progress of hexane lenses on water surface with different temperature
Authors: Chen Aiqiang , Chen Xin , Miao Xinxin , Yin Jinghong , Liu Bin
Published: August 2020

The evolution of an evaporating liquid on another nonmiscible fluid is important for many applications. An experimental study on the evaporation process of hexane lens on the surface of deionized water at different temperatures was carried out, and the surface temperature distribution characteristics and internal flow pattern evolution was analyzed. Results show that the surface temperature of hexane lens can be divided into two parts or three areas depending on the temperature of deionized water. The increasing temperature of deionized water gradually changes both vertical temperature gradient and radial temperature gradient inside hexane lens, and their competition determines the flow pattern inside the hexane lens. Flow along hexane edge caused by circumferential surface tension gradient forms a “low temperature channel” between the central low temperature region and the strong evaporation edge. The knowledge will benefit the fundamental understanding of evaporation characteristics of volatile droplets on a liquid surface.
Lockdown-related idiopathic facial paralysis: illustration of an indirect victim of the COVID-19 pandemic?
Authors: Fricain Margaux , Moreau Nathan
Published: August 2020

Introduction: In the midst of the COVID-19 pandemic, there are numerous reports of SARS-CoV-2-related symptoms in many medical subspecialties. Unfortunately, there seems to be little focus on indirect victims of COVID-19, such as diseases/ailments secondary to COVID-19-related lockdown in relevant countries. Observation: We report a case of idiopathic facial paralysis (Bell's Palsy) that occurred in an otherwise-healthy 49-year-old French chef during nationwide lockdown, possibly fostered by severe concerns regarding his professional prospects. Other manifestations of severe anxiety were also observed such as tension-type headache and psoriasis outbreaks. Prednisone and valaciclovir were initiated, in association with simple counselling. Commentary and conclusion: As HSV-1 reactivation in the facial nerve is suspected in the pathophysiology of idiopathic facial paralysis, this case could constitute an example of lockdown-related disease and an illustration of indirect manifestations of the COVID-19 pandemic. Such indirect diseases are likely to increase as the pandemic continues to take its toll both medically and socio-economically.
Gabapentinoid prescription in Oral Medicine and Oral Surgery practice. Part II − a systematic scoping review of the literature
Authors: Sulukdjian Arek , L'Homme Richard , Chanlon Audrey , Moreau Nathan
Published: August 2020

Introduction: Gabapentinoids, pregabalin and gabapentin, neuronal voltage-gated calcium channel inhibitors are first-line treatments for painful neuropathic conditions (and several non-neuropathic painful conditions). Nevertheless, their efficacy and prescription in Oral Medicine and Oral Surgery practice has received little attention so far. A previous article, the first of a two-part series, presented the experience of a French tertiary orofacial pain clinic regarding the prescription of gabapentinoids in orofacial conditions. This second article aimed to explore the scientific literature on the subject. Material and methods: A systematic scoping review was conducted on multiple relevant databases (MEDLINE®, Cochrane®, Agence Nationale de Sécurité du Médicament et des produits de santé, Haute Autorité de Santé) and journal archives (JOMOS, JSOMFS) to assess the indications, non-indications and contraindications of gabapentinoids in an Oral Medicine/Oral Surgery context. Results: Out of 131 records selected during the initial screening, 34 matched the inclusion criteria and were used for subsequent analyses. Gabapentinoids were prescribed in three clinical contexts: orofacial pain management (32 studies), anxiolysis (1 study) and prevention of postoperative nausea/vomiting (1 study), with variable quality of evidence: high (6 studies), moderate (3 studies), low (5 studies) and very low (20 studies) quality studies (GRADE scale). Untoward effects of gabapentinoids were reported in 16 studies, mainly neurological (vertigo, drowsiness, sedation) and gastro-intestinal (nausea, vomiting, diarrhea, constipation). Gabapentinoids were ineffective in preemptive and postoperative analgesia and for the management of mucositis-related pain. Discussion: There is some evidence supporting the use of gabapentinoids in Oral Medicine/Oral Surgery in adherence with current practices observed in France and other countries (practices often extrapolated from their use in other non-orofacial painful conditions). The methodological quality of the studies included in this scoping review is often poor and publication bias is most probable in this field. Therefore, any conclusion drawn from such studies must be subject to circumspection. Conclusion: Data obtained from the present scoping review suggests the potential use of gabapentinoids as second-line treatments for anxiolysis, prevention of postoperative nausea/vomiting and the management of trigeminal neuralgia and masticatory myalgia. Other potential indications of gabapentinoids in Oral Medicine/Oral Surgery practice include cranial neuralgias, post-traumatic trigeminal neuropathies, first bite syndrome, burning mouth syndrome and migraine prophylaxis, when other treatment options are inefficient or unavailable.
On the geodetic hull number for complementary prisms II
Authors: Castonguay Diane , Coelho Erika M. M. , Coelho Hebert , Nascimento Julliano R.
Published: August 2020

In the geodetic convexity, a set of vertices S of a graph G is convex if all vertices belonging to any shortest path between two vertices of S lie in S. The convex hull H(S) of S is the smallest convex set containing S. If H(S) = V (G), then S is a hull set. The cardinality h(G) of a minimum hull set of G is the hull number of G. The complementary prism GḠ of a graph G arises from the disjoint union of the graph G and Ḡ by adding the edges of a perfect matching between the corresponding vertices of G and Ḡ. A graph G is autoconnected if both G and Ḡ are connected. Motivated by previous work, we study the hull number for complementary prisms of autoconnected graphs. When G is a split graph, we present lower and upper bounds showing that the hull number is unlimited. In the other case, when G is a non-split graph, it is limited by 3.
Comparison of Omegawave Device and an Ambulatory ECG for RR Interval
Measurement at rest
Authors: Naranjo-Orellana José , Ruso-Álvarez José Francisco , Rojo-Álvarez José Luis
Published: August 2020

The aim of this study was to validate the measurements of the beat intervals
taken at rest by the Omegawave® device by comparing them to
an ambulatory electrocardiogram system. For this purpose, the electrocardiogram
was digitally processed, time-aligned, and scrutinized for its suitable use as
gold-standard. Rest measurements were made for 10 minutes on 5 different days to
10 men and 3 women (24.8±5.05 years; 71.82±11.02 kg;
174.35±9.13 cm). RR intervals were simultaneously recorded using
the Omegawave device and a Holter electrocardiogram. The processing of Holter
electrocardiogram signals included the detrending of baseline noise and a
high-pass filtering for emphasizing the QRS complexes and attenuating the T
waves. After obtaining the RR intervals from the electrocardiogram, those from
the Omegawave device were automatically aligned to them with cross-correlation
digital processing techniques and compared to check whether both measurements
could be considered superimposable. A Bland-Altman analysis was applied to the 5
measurements made for all subjects. The Omegawave device exhibited very strong
agreement with a quality-controlled Holter electrocardiogram. Deviations not
exceeding 25 ms could be expected in 95% of the cases, which is
within manageable ranges both for clinical practice and for sports.
Parasympathetic Nervous Activity Responses to Different Resistance
Training Systems
Authors: Kassiano Witalo , de Vasconcelos Costa Bruna Daniella , Lima-Júnior Daltonde , Gantois Petrus , de Souza Fonseca Fabiano , da Cunha Costa Manoel , de Sousa Fortes Leonardo
Published: August 2020

The assessment of parasympathetic nervous activity and psychophysiological
responses infers the stress imposed by different resistance training systems.
Therefore, we compare the effects of different sets configurations, with similar
volume (~60 repetitions), on heart rate variability indices and internal
training load. Twenty-nine resistance-trained adults completed the following
conditions: traditional without and with muscle failure, inter-repetition rest,
and rest-pause in the parallel squat. The heart rate variability indices
(time-domain) were measured before and 30 min after each condition. The internal
training load was obtained through the session-rating of perceived exertion
method. Except for inter-repetition rest, all conditions reduced the heart rate
variability indices after the session (P<0.05), and the
rest-pause triggered the higher reductions (≤−46.7%).
The internal training load was higher in the rest-pause
(≤68.9%). Our results suggest that rest-pause configuration
leads to more considerable disruption of the parasympathetic nervous activity
and higher internal training load in trained adults. In contrast,
inter-repetition rest allows lower autonomic and psychophysiological stress.
Pediatric Microsurgery in the Reconstruction of Complex Posttraumatic Foot and Ankle Defects: A Long-Term Follow-Up with a Comprehensive Review of the Literature
Authors: Elbatawy Amr , Elgammal Mohammed , Zayid Tarek , Hamdy Abdelnaser , Ouf Mohamed Osama , Ismail Hany , Sholkamy Khallad , Malik Mohammad , Zidan Serag M. , Ayad Wael
Published: August 2020

Background Lower limb reconstruction is a well-recognized challenge to the trauma or plastic surgeon. Although techniques and outcomes in the adult population are well documented, they are less so in the pediatric population. Here, we present our experience in the management of posttraumatic foot and ankle defects with free tissue transfer in children.

Methods We performed a retrospective analysis of 40 pediatric patients between the ages of 3 and 16 from 2008 to 2016 who underwent foot and ankle soft tissue reconstruction. Any patient who underwent reconstruction for any reason other than trauma was excluded. Data were collected on operative time, free tissue transfer type, use of vein grafts, length of hospital stay, and postoperative morbidity. Also, a comprehensive systematic literature review was completed according to the PRISMA protocol for all previous reports of foot and ankle reconstruction in the young age group with free tissue transfer.

Results Of our 40 patients, 23 were males and 12 females, free tissue transfer was used to reconstruct primarily the dorsum (71%), heel (11%), medial (9%), and lateral (3%) aspect of the foot. The anterior tibial artery was the predominant recipient vessel for anastomosis (77%). Mean inpatient stay was 9 days and our complication rate was 20%, primarily of superficial infection treated with antibiotic therapy. The review of the literature articles is completely analyzed in detail.

Conclusion The need for durable coverage of exposed joints, tendons, fractures, or hardware makes the free flap particularly well suited to trauma reconstruction of the foot and ankle. The lack of underlying vascular disease in this patient group allows for low complication rates. Our study evidences the safety and positive long-term outcomes of free tissue transfer for the reconstruction of huge sized-soft tissue defects of the foot and ankle in children.
Modeling power and linewidth of quantum dot superluminescent light emitting diode
Authors: Guin Shampa , Das Nikhil Ranjan
Published: August 2020

A model for quantum dot (QD) superluminescent light emitting diode (SLED) is presented to study an optical power output and linewidth over a wide range of injection currents. The analysis is based on the photon and carrier rate equations including the effects of homogeneous and inhomogeneous broadening, carrier escape process, and high-current heating. The model is validated using experimental data available from the literature. The results show non-monotonic variations of the output optical power and linewidth of the SLED with the injection current density. It is seen that there exists an optimum injection current density for which the power–linewidth product becomes maximum for a given device length of the QD SLED.
An ultrasound probe array for a high-pressure, high-temperature solid medium deformation apparatus
Authors: Ghaffari H. O. , Pec M.
Published: August 2020

Inelastic deformation of minerals and rocks is associated with activation of various defects such as fractures, twins, and dislocations. Active and passive ultrasound probes are potential tools to examine the nature of these defects under a broad range of pressure and temperature conditions. Here, we report on the development of an ultrasound probe array that allows us to monitor deforming samples in a high-pressure, high-temperature solid medium apparatus (a modified Griggs rig). We utilize several broadband miniature piezoelectric sensors that are placed above and below the sample to record acoustic emissions accompanying deformation and determine their locations in 1D. The emissions are recorded at 50 MS/s with a 12 bit resolution. Proper grounding and electric insulation of the sensors, together with optimized power delivery from the heating system, tremendously reduces electromagnetic interference and allows for a background noise level of ≈90 mV at a full range of ±2 V and 60 dB amplification. The system is capable of recording acoustic waves from 80 kHz to 2.5 MHz at sample temperatures up to 1100 °C and confining pressure up to 2.5 GPa.
Electromagnetic Hopkinson bar: A powerful scientific instrument to study mechanical behavior of materials at high strain rates
Authors: Guo Yazhou , Du Bing , Liu Huifang , Ding Zhupan , Zhao Zhenqiang , Tang Zhongbin , Suo Tao , Li Yulong
Published: August 2020

The split Hopkinson bar (SHB) has been widely used for testing the dynamic mechanical behavior of materials. However, it is hard to involve complex stress conditions in traditional SHB due to its intrinsic characteristics. The Electromagnetic Hopkinson bar (E-Hopkinson bar) has been recently proposed as a solution. Different from the traditional SHB, the stress pulse of the E-Hopkinson bar is generated directly by the electromagnetic force. Therefore, the stress pulse that loads the specimen can be accurately controlled. With this advantage, some experiments that cannot be done with traditional SHB can be conducted by the E-Hopkinson bar technique. In this review, we introduced briefly the basic principles of the E-Hopkinson bar. Some lasted tests, such as symmetrically dynamic compression/tension of materials, interlaminar fracture of composites, dynamic Bauschinger effect of metals, intermediate strain rate tests, and dynamic multi-axial tests were also introduced. This new technique will be helpful for those researchers in the field of solid mechanics, especially when the strain rate and complex stress condition are involved.
Enhanced thermoelectricity at the ultra-thin film limit
Authors: Nguyen Thao Thi Thu , Dang Linh Tuan , Bach Giang Huong , Dang Tung Huu , Nguyen Kien Trung , Pham Hong Thi , Nguyen-Tran Thuat , Nguyen Tuyen Viet , Nguyen Toan The , Nguyen Hung Quoc
Published: August 2020

At the ultra-thin film limit, quantum confinement strongly improves the thermoelectric figure of merit in materials such as Sb2Te3 and Bi2Te3. These high quality films have only been realized using well controlled techniques such as molecular beam epitaxy. We report a twofold increase in the Seebeck coefficient for both p-type Sb2Te3 and n-type Bi2Te3 using thermal co-evaporation, an affordable approach. At the thick film limit greater than 100 nm, their Seebeck coefficients are around 100 μV/K, similar to the results obtained in other works. When the films are thinner than 50 nm, the Seebeck coefficient increases to about 500 μV/K. With the Seebeck coefficient ∼1 mV/K and an estimate ZT ∼0.6, this pair of materials presents the first step toward a practical micro-cooler at room temperature.
Investigation of heat transfer across a nanoscale air gap between a flying head and a rotating disk
Authors: Sakhalkar S. , Cheng Q. , Ghafari A. , Bogy D.
Published: August 2020

Understanding nanoscale heat transfer at the head–disk interface (HDI) is necessary for thermal management of hard disk drives (HDDs), especially for heat-assisted magnetic recording and microwave-assisted magnetic recording. To accurately model the head temperature profile in HDDs, it is imperative to employ a spacing-dependent heat transfer coefficient due to the combined effects of pressurized air conduction and wave-based phonon conduction. Moreover, while flying at near-contact, the fly height and heat transfer are affected by adhesion/contact forces in the HDI. In this study, we develop a numerical model to predict the temperature profile and the fly height for a flying slider over a rotating disk. We compare our simulations with touchdown experiments performed with a flying Thermal Fly-Height Control (TFC) slider with a near-surface Embedded Contact Sensor (ECS), which helps us to detect the temperature change. We incorporate the effects of disk temperature rise, adhesion/contact forces, air and phonon conduction heat transfer, and friction heating in our model. As the head approaches the disk with increasing TFC power, enhanced nanoscale heat transfer leads to a drop in the ECS temperature change vs TFC power curve. We find that the exclusion of the disk temperature rise causes the simulation to overestimate the ECS cooling drop. The incorporation of adhesion force results in a steeper ECS cooling drop. The addition of phonon conduction in the model causes a larger ECS cooling drop. The simulation with friction heating predicts a larger ECS temperature slope beyond contact. The simulation with these features agrees with the experiment.
Electrically tunable high Curie temperature two-dimensional ferromagnetism in van der Waals layered crystals
Authors: Wang Hua , Qi Jingshan , Qian Xiaofeng
Published: August 2020

Identifying intrinsic low-dimensional ferromagnets with high magnetic transition temperature and electrically tunable magnetism is crucial for the development of miniaturized spintronics and magnetoelectrics. Recently, long-range 2D ferromagnetism was observed in van der Waals crystals CrI3 and Cr2Ge2Te6, however, their Curie temperature is significantly lowered when reducing down to monolayer/few layers. Herein, using renormalized spin-wave theory and first-principles electronic structure theory, we present a theoretical study of electrically tunable 2D ferromagnetism in van der Waals layered CrSBr and CrSeBr semiconductors with a high Curie temperature of ∼150 K and a sizable bandgap. The high transition temperature is attributed to the strong anion-mediated superexchange interaction and a sizable spin-wave excitation gap due to large exchange and single-ion anisotropy. Remarkably, hole and electron doping can switch the magnetization easy axis from the in-plane to the out-of-plane direction. These unique characteristics establish monolayer CrSBr and CrSeBr as a promising platform for realizing 2D spintronics and magnetoelectrics such as 2D spin valves and spin field effect transistors.
The impact of flexoelectricity on materials, devices, and physics
Authors: Deng Qian , Lv Sihao , Li Zhaoqi , Tan Kai , Liang Xu , Shen Shengping
Published: August 2020

In dielectric materials, due to the flexoelectric effect, a large inhomogeneous deformation can break or significantly alter the inversion symmetry of the material and induce net polarization. Such a phenomenon is distinctive comparing to other forms of electromechanical coupling, such as piezoelectricity and electrostriction, in that it is an intrinsic and universal effect whose strength scales up with the decrease in the sample size. Research works in the past decade indicate that the emergence of flexoelectricity not only provides a new way of realizing electromechanical coupling, but also has impact on multiple fields including smart materials, devices, and even physics. Our objective of this perspective is to briefly introduce the field of flexoelectricity and discuss on its future development. Also, current challenges and ambiguities that may impede the further development of the field are pointed out. Furthermore, our opinions on why flexoelectricity matters and how can we use it in novel ways are presented.
Electrical modulation of the LWIR absorption and refractive index in InAsSb-based strained layer superlattice heterostructures
Authors: Liu Jinghe , Donetsky Dmitry , Jiang Haiying , Kipshidze Gela , Shterengas Leon , Belenky Gregory , Sarney Wendy L. , Svensson Stefan P.
Published: August 2020

InAsSb-based strained layer superlattices (SLS) have strong fundamental absorption, which can be easily modified in a controlled manner by injecting excess carriers. This makes them attractive for intensity modulation of infrared lasers as well as beam steering and spatial beam shaping with a nanosecond-scale time response. This paper reports the modulation of the fundamental absorption and the refractive index by carrier injection in a 3.45-nm-period InAsSb0.65/InAsSb0.35 SLS with a low temperature energy gap of 85 meV grown by molecular beam epitaxy on a GaSb substrate with a GaInSb metamorphic buffer. The SLS absorber was sandwiched by n- and p-type wider energy gap layers for electrical injection and confinement of excess carriers. The population of conduction band states was obtained by measuring the intensity modulation of a 10.6 μm CO2 laser for temperatures ranging from T = 77 to 200 K. An increase of the electron quasi-Fermi level with electrical injection up to 20 meV was observed. The experimental data imply a decrease in the Auger coefficient with temperature, from 3 × 1024 cm6/s at 77 K to 1 × 1024 cm6/s at T = 200 K attributed to recombination involving two electrons and a heavy hole. The refractive index changes obtained by electrical injection of excess carriers can reach 0.05 at T = 77 K and 0.035 at T = 200 K, which are at least three orders of magnitude greater than those obtained with electro-optical materials.
Realization of mutual synchronization of spin torque nano-oscillators under room temperature by noise reduction technique
Authors: Zeng Lang , Xu Xiaojun , Chen Hao-Hsuan , Zhou Yan , Zhang Deming , Wang Yijiao , Zhang Youguang , Zhao Weisheng
Published: August 2020

The pragmatic use of Spin Torque Nano-Oscillators (STNOs) in real electronic systems is severely hindered due to their low output power and poor noise figure. The most accepted and promising way to increase the output power and decrease the signal noise of STNOs is through their mutual synchronization. However, it is confused that the mutual synchronization of STNOs is very difficult to achieve at room temperature although the non-linear nature of STNOs contributes to the large frequency range of injection locking. In this work, first, it is revealed that the difficulty of STNOs' mutual synchronization stems from the high output signal noise of STNOs. Based on this observation, a noise reduction technique is invented, which introduces a Band Pass Filter in the coupling loop of STNOs. Using the noise reduction technique, it is demonstrated that even non-identical STNOs can be mutually synchronized at room temperature.
On the role of surface grooves in the reduction of pressure losses in heated channels
Authors: Hossain M. Z. , Floryan J. M.
Published: August 2020

Pressure-gradient-driven flows in grooved horizontal channels were investigated. The results show that a significant reduction in pressure losses can be achieved by exposing such channels to spatially distributed heating. The system response strongly depends on the characterization of both patterns and on their relative position, leading to a pattern interaction problem. Mismatch and misplacement of both patterns may result in a significant increase in pressure losses or may have no effect on such losses. The reduction in pressure loss is associated with the formation of convection rolls on the bounding surfaces due to spatially distributed buoyancy along the streamwise direction. The pressure-gradient-reducing effect is active only in small Reynolds number flows. Explicit results are given for fluids with the Prandtl number Pr = 0.71, representing air.
Temperature limitations for stimulated emission in 3–4
μ
m range due to threshold and non-threshold Auger recombination in HgTe/CdHgTe quantum wells
Authors: Kudryavtsev K. E. , Rumyantsev V. V. , Aleshkin V. Ya. , Dubinov A. A. , Utochkin V. V. , Fadeev M. A. , Mikhailov N. N. , Alymov G. , Svintsov D. , Gavrilenko V. I. , Morozov S. V.
Published: August 2020

We report on the stimulated emission (SE) from HgTe/CdHgTe quantum well (QW) heterostructures up to 240 K at 3.7 μm wavelength. Based on the temperature dependence of the SE threshold, a total Auger recombination (AR) coefficient of 10−27 cm6/s has been deduced for HgTe/CdHgTe QWs, which is much lower than that for bulk HgCdTe with the same bandgap and indicates suppression of (threshold) AR processes due to the symmetry of carrier dispersion curves. We demonstrate that QW-specific, non-threshold AR contributes strongly to the temperature quenching of laser action from HgTe/CdHgTe QWs. We expect, however, that the above processes may be partially suppressed via introduction of wide-gap CdHgTe barrier layers with a [Cd] fraction of 80% or higher. In this case, lasing up to at least 270 K at 3.7 μm wavelength seems feasible.
Minimal auxiliary basis set for time-dependent density functional theory and comparison with tight-binding approximations: Application to silver nanoparticles
Authors: Giannone Giulia , Della Sala Fabio
Published: August 2020

The modeling of optical spectra of plasmonic nanoparticles via first-principles approaches is computationally expensive; thus, methods with high accuracy/computational cost ratio are required. Here, we show that the Time-Dependent Density Functional Theory (TDDFT) approach can be strongly simplified if only one s-type function per atom is employed in the auxiliary basis set, with a properly optimized exponent. This approach (named TDDFT-as, for auxiliary s-type) predicts excitation energies for silver nanoparticles with different sizes and shapes with an average error of only 12 meV compared to reference TDDFT calculations. The TDDFT-as approach resembles tight-binding approximation schemes for the linear-response treatment, but for the atomic transition charges, which are here computed exactly (i.e., without approximation from population analysis). We found that the exact computation of the atomic transition charges strongly improves the absorption spectra in a wide energy range.
The bounded rationality of probability distortion
Authors: Zhang Hang , Ren Xiangjuan , Maloney Laurence T.
Published: August 2020

Significance

People distort probability in decision under risk and many other tasks. These distortions can be large, leading us to make markedly suboptimal decisions. There is no agreement on why we distort probability. Distortion changes systematically with task, hinting that distortions are dynamic compensations for some intrinsic “bound” on working memory. We first develop a model of the bound and compensation process and then report an experiment showing that the model accounts for individual human performance in decision under risk and relative frequency judgments. Last, we show that the particular compensation in each experimental condition serves to maximize the mutual information between objective decision variables and their internal representations. We distort probability to compensate for our own perceptual and cognitive limitations.
Hyperpolarized [1-
13
C]pyruvate-to-[1-
13
C]lactate conversion is rate-limited by monocarboxylate transporter-1 in the plasma membrane
Authors: Rao Yi , Gammon Seth , Zacharias Niki M. , Liu Tracy , Salzillo Travis , Xi Yuanxin , Wang Jing , Bhattacharya Pratip , Piwnica-Worms David
Published: August 2020

Significance

Hyperpolarized [1-
13
C]pyruvate magnetic resonance spectroscopic imaging (MRSI), which measures [1-
13
C]pyruvate-to-[1-
13
C]lactate conversion, has been widely explored as a metabolic-imaging modality interpreted to reflect LDHA activity and glycolytic flux. However, we show definitively that hyperpolarized [1-
13
C]pyruvate-to-[1-
13
C]lactate conversion rates are primarily a functional readout of [1-
13
C]pyruvate transmembrane influx mediated by MCT1, providing a mechanistic reinterpretation and redirection of clinical translation.
How cholesterol stiffens unsaturated lipid membranes
Authors: Chakraborty Saptarshi , Doktorova Milka , Molugu Trivikram R. , Heberle Frederick A. , Scott Haden L. , Dzikovski Boris , Nagao Michihiro , Stingaciu Laura-Roxana , Standaert Robert F. , Barrera Francisco N. , Katsaras John , Khelashvili George , Brown Michael F. , Ashkar Rana
Published: August 2020

Significance

Cholesterol regulates critical cell functions, including lysis, viral budding, and antibiotic resistance, by modifying the bending rigidity of cell membranes; i.e., the ability of membranes to bend or withstand mechanical stresses. A molecular-level understanding of these functions requires knowledge of how cholesterol modifies membrane mechanics over relevant length and time scales. Currently, it is widely accepted that cholesterol has no effect on the mechanical properties of unsaturated lipid membranes, implying that viruses, for example, can bud from regions enriched in (poly)unsaturated lipids. Our observations that cholesterol causes local stiffening in DOPC membranes indicate that a reassessment of existing concepts is necessary. These findings have far-reaching implications in understanding cholesterol’s role in biology and its applications in bioengineering and drug design.
An enumerative algorithm for de novo design of proteins with diverse pocket structures
Authors: Basanta Benjamin , Bick Matthew J. , Bera Asim K. , Norn Christoffer , Chow Cameron M. , Carter Lauren P. , Goreshnik Inna , Dimaio Frank , Baker David
Published: August 2020

Significance

Reengineering naturally occurring proteins to have new functions has had considerable impact on industrial and biomedical applications, but is limited by the finite number of known proteins. A promise of de novo protein design is to generate a larger and more diverse set of protein structures than is currently available. This vision has not yet been realized for small-molecule binder or enzyme design due to the complexity of pocket-containing structures. Here we present an algorithm that systematically generates NTF2-like protein structures with diverse pocket geometries. The scaffold sets, the insights gained from detailed structural characterization, and the computational method for generating unlimited numbers of structures should contribute to a new generation of de novo small-molecule binding proteins and catalysts.
Structural base for the transfer of GPI-anchored glycoproteins into fungal cell walls
Authors: Vogt Marian Samuel , Schmitz Gesa Felicitas , Varón Silva Daniel , Mösch Hans-Ulrich , Essen Lars-Oliver
Published: August 2020

Significance

The synthesis and maturation of the cell wall are essential for fungal life. Factors involved in these processes provide a potential platform with side effect-free, antimycotic targets. A key step in cell-wall biogenesis is the transfer of GPI-anchored proteins from the plasma membrane to the glycan meshwork as catalyzed by Dfg5 enzymes. We characterize the structure of a member of the Dfg5 subfamily and provide insights into the architecture of the GPI-core glycan when bound to Dfg5 as supported by MD simulations and in vivo analysis in yeast. Our data let us propose a sorting mechanism at the fungal cell surface and set a base for structure-based drug development using this important cell-wall biosynthesis factor.
Human epidermal stem cell differentiation is modulated by specific lipid subspecies
Authors: Vietri Rudan Matteo , Mishra Ajay , Klose Christian , Eggert Ulrike S. , Watt Fiona M.
Published: August 2020

Significance

Cells generate a vast repertoire of lipid molecules whose functions are poorly understood. To investigate whether lipids can regulate cell fate decisions, we carried out a systematic lipidomic analysis and perturbation of lipid metabolism in cultured human epidermal keratinocytes, determining associations with the onset of differentiation. We identified individual lipid species that induced exit from the epidermal stem cell compartment. Our observations suggest that more research is warranted on the regulation of biological processes via lipid species, moving beyond the more conventional contribution of proteins and nucleic acids.
Configurational entropy of basaltic melts in Earth’s mantle
Authors: Lee Sung Keun , Mosenfelder Jed L. , Park Sun Young , Lee A. Chim , Asimow Paul D.
Published: August 2020

Significance

Proper inference of the seismological and chemical effects of partial melting in Earth’s upper mantle depends on physical properties of interstitial melts at elevated pressure. Silicate liquids display anomalous softening upon compression. This lacks an atomic-scale explanation, partly because studies linking microstructure and physical properties of melts are limited to ambient pressure. Here we studied basaltic glass quenched from high pressure with multinuclear NMR spectroscopy that defines the populations of oxygen species in the glass with sufficient precision to reveal a decrease with pressure in the configurational entropy, which we attribute to entanglement of the melt network upon densification. We explain how the configurational entropy can be used as a tool to explain the anomalous behavior of melts under compression.
Being native and being foreign
Authors: Minagawa Harumi , Nesbitt Dallas
Published: August 2020

Pennington and Richards (2016) argue that if the medium of instruction (MOI) is
not the native language of the instructor, lack of proficiency in the MOI could bring about a lack of confidence. This study inquired how
native Japanese as a Foreign Language (JFL) teachers at tertiary institutions in New Zealand and Australia perceive their English
proficiency, how it influences their linguistic identity, and how the fact that they are native speakers of the target language influences
their linguistic identity. Based on responses from an online questionnaire with more than 50 respondents as well as 12 follow-up individual
interviews, this study argues that their linguistic identity is not narrowly conceived around their non-nativeness in English and nativeness
in Japanese, but constructed from more multi-faceted aspects of language teacher identity formation, especially by factors pertinent to the
very nature of the tertiary teaching environment in these countries.
LncRNA TUG1 reverses LPS-induced cell apoptosis and inflammation of macrophage via targeting MiR-221-3p/SPRED2 axis
Authors: Hu Lili , Ye Hongwei , Liao Jianjun
Published: August 2020

This study aimed to identify the role of lncRNA TUG1 with miR-221-3p on mice with lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS). Animal model was established, and lung tissue histopathologic status and permeability were detected by hematoxylin-eosin (HE) or Evans blue dye assay respectively. Levels of inflammation cytokines, lncRNA TUG1, miR-221-3p, sprouty related EVH1 domain-containing 2 (SPRED2), and phosphorylated (p)-ERK1/2 were determined by ELISA, qRT-PCR or Western blot. Pulmonary impairment and apoptosis were examined by flow cytometry. We observed that LPS up-regulated levels of tumor necrosis factor-α (TNF-α), Interleukin-1β (1L-1β), and ERK1/2 phosphorylation, and reduced SPRED2 levels, which were rescued by overexpressed lncRNA TUG1. StarBase and dual-luciferase reporter assay verified that miR-221-3p was targeted by lncRNA TUG1. MiR-221-3p could reverse the effect of lncRNA TUG1 on cell apoptosis, levels of TNF-α, IL-1β, SPRED2, and p-ERK1/2. Therefore, overexpressed lncRNA TUG1 attenuated LPS-induced pulmonary impairment in ARDS mice via regulating miR-221-3p/SPRED2 axis.
Experimental artefacts can lead to misattribution of bioactivity from soluble mesenchymal stem cell paracrine factors to extracellular vesicles
Authors: Whittaker Thomas E. , Nagelkerke Anika , Nele Valeria , Kauscher Ulrike , Stevens Molly M.
Published: August 2020

It has been demonstrated that some commonly used Extracellular Vesicle (EV) isolation techniques can lead to substantial contamination with non‐EV factors. Whilst it has been established that this impacts the identification of biomarkers, the impact on apparent EV bioactivity has not been explored. Extracellular vesicles have been implicated as critical mediators of therapeutic human mesenchymal stem cell (hMSC) paracrine signalling. Isolated hMSC‐EVs have been used to treat multiple in vitro and in vivo models of tissue damage. However, the relative contributions of EVs and non‐EV factors have not been directly compared. The dependence of hMSC paracrine signalling on EVs was first established by ultrafiltration of hMSC‐conditioned medium to deplete EVs, which led to a loss of signalling activity. Here, we show that this method also causes depletion of non‐EV factors, and that when this is prevented proangiogenic signalling activity is fully restored in vitro. Subsequently, we used size‐exclusion chromatography (SEC) to separate EVs and soluble proteins to directly and quantitatively compare their relative contributions to signalling. Non‐EV factors were found to be necessary and sufficient for the stimulation of angiogenesis and wound healing in vitro. EVs in isolation were found to be capable of potentiating signalling only when isolated by a low‐purity method, or when used at comparatively high concentrations. These results indicate a potential for contaminating soluble factors to artefactually increase the apparent bioactivity of EV isolates and could have implications for future studies on the biological roles of EVs.
Recreation ecology research in China’s protected areas: progress and prospect
Authors: Zhong Linsheng , Zhang Xiangju , Deng Jinyang , Pierskalla Chad
Published: August 2020

As a type of tourist destination, Protected Areas (PAs) have been the focus of recreation ecology research since their establishment. The contradiction between recreation and ecological protection of PAs in China is more prominent than in other countries because of China’s large population density and complex PA management system. Thus, a review of related research is urgent for promoting sustainable tourism development of PAs in China. Combining quantitative analysis with a literature review, this study analyzed the historical development process and current research topics of recreation ecology in China’s PAs, focusing on the impacts of tourism on the natural environment, environmental management of tourism, and the development of different types of sustainable tourism in PAs. Overall, the research gaps are as follows: (1) studies on impact mechanism of tourism based on long-term monitoring are lacking; (2) the existence of numerous local communities in most of the PAs in China is usually ignored; (3) insufficient attention has been paid to the impacts of tourism infrastructure construction; (4) assessments of sustainable PA tourism are lacking. Correspondingly, this paper presents implications for future research and serves as a reference for PA tourism management in other countries.
pH-responsive SERS substrates based on AgNP-polyMETAC composites on patterned self-assembled monolayers
Authors: Wang Limin , Wei Peng , Stumpf Steffi , Schubert Ulrich S , Hoeppener Stephanie
Published: August 2020

Patterned silver nanoparticle (NP)-poly[2-(methacryloyloxy)ethyl] trimethyl ammonium chloride (AgNP-polyMETAC) composites were prepared by electrochemical lithography, surface-initiated atom-transfer radical polymerization (SI-ATRP) and NP growth inside the polymer brushes. For this purpose, polymer brushes of poly[2-(methacryloyloxy)ethyl] trimethyl ammonium chloride (polyMETAC) were utilized as strong electrolyte brush system. These were introduced in form of patterned polymer brushes to create pH-responsive surface enhanced Raman scattering SERS substrates. It is well-known that the charges of strong polyelectrolyte chains are usually insensitive to pH changes, hence, rarely strong polyelectrolyte brushes have been utilized so far to study pH-responsive properties of such films. Here pH-insensitive polyMETAC brushes exhibit pH-sensitive properties and can be used as pH-responsive surfaces for SERS applications due to the embedding of AgNPs into the polymer brushes. When increasing the pH, the assembly of the AgNPs transfers from quasi two-dimensional (2D) aggregates, attaching mainly to the polymer surface, into a three-dimensional (3D) assembly, where the particles are penetrating into the brushes. These changes result in significant alterations of the SERS efficiency of the polymer brush composite. At pH 5, the enhancement of the Raman scattering approaches its maximum. The fabricated SERS substrates show a high sensitivity as well as good experimental reliability at different pH values. Moreover, electrochemical lithography was utilized to fabricate patterned SERS substrate, which allows an easy combination of multiple other functionalities in hierarchical structuring steps. In addition, the microstructure is in our studies beneficial because of a simplified and reliable characterization of the polymer brushes at defined sample areas. The introduction of the microstructured brush system is regarded moreover attractive for the development of high-throughput platforms for rapid, automated screening and analysis applications.
Method for the production of pure and C-doped nanoboron powders tailored for superconductive applications
Authors: Capra Marco , Loria Federico , Bernini Cristina , Bovone Gianmarco , Moros Alice , Stöger-Pollach Michael , Schachinger Thomas , Bernardi Johannes , Siri Antonio Sergio , Vignolo Maurizio
Published: August 2020

The present paper describes the improvement of the performances of boron powder obtained applying the freeze-drying process (FDP) for the nanostructuration and doping of B2O3, which is here used as boron precursor. After the nanostructuration process, B2O3 is reduced to elemental nanoboron (nB) through magnesiothermic reaction with Mg. For this work, the usefulness of the process was tested focusing on the carbon-doping (C-doping), using Cblack, inulin and haemoglobin as C sources. The choice of these molecules, their concentration, size and shape, aims at producing improvements in the final compound of boron: in this case the superconductive magnesium diboride, which has been prepared and characterized both as powder and wire. The characteristics of B2O3, B and MgB2 powder, as well as MgB2 wire were tested and compared with that obtained using the best commercial precursors: H. C. Starck micrometric boron and Pavezyum nanometric boron. Both the FDP and the magnesiothermic reaction were carried out with simplicity and a great variety of doping sources, i.e. elements or compounds, which can be organic or inorganic and soluble or insoluble. The FDP allows to produce nB suitable for numerous applications. This process is also very competitive in terms of scalability and production costs if compared to the via gas technique adopted by nanoboron producers currently available on the world market.
Blue phosphorene reactivity on the Au(111) surface
Authors: Zhang Wei , Enriquez Hanna , Zhang Xuan , Mayne Andrew J , Bendounan Azzedine , Dappe Yannick J , Kara Abdelkader , Dujardin Gérald , Oughaddou Hamid
Published: August 2020

The synthesis of blue phosphorene by molecular beam epitaxy (MBE) has recently come under the spotlight due to its potential applications in electronic and optoelectronic devices. However, this synthesis remains a significant challenge. The surface reactivity between the P atoms and the Au atoms should be considered for the P/Au(111) system. In the MBE process, the temperature of the substrate is a key parameter for the growth of blue phosphorene. During the initial growth stage, irregularly shaped Phosphorus clusters grow on top of Au(111) surface at room temperature. When the substrate temperature is increased, these clusters transform into a phosphorene-like structure with a honeycomb lattice. An atom exchange reaction is observed between the P and first layer Au atoms under thermal activation at higher temperature, where the P atoms replace Au atoms to form a blue phosphorene structure within the top Au layer and at the step edges.
Efficient fusion of photonic W-states with nonunitary partial-swap gates
Authors: Wei Hai-Rui , Liu Wen-Qiang , Kwek Leong-Chuan
Published: August 2020

We introduce a nonunitary partial-swap gate for fusing arbitrary small-sized photonic W-states into a large-scale entangled network of W-state efficiently without ancillary photons. A partial-swap gate is designed in an optical architecture based on linear optics elements. By introducing auxiliary degree of freedom, this gate provides a higher success probability with less cost. Our implementation can create a larger target state with a simpler set-up than previous proposals for W-state fusion. Also all ‘garbage’ states are recyclable, i.e., there is no complete failure output in our scheme in principle.
Random-injection-based two-channel chaos with enhanced bandwidth and suppressed time-delay signature by mutually coupled lasers: Proposal and numerical analysis*
Authors: Xu Shi-Rong , Jia Xin-Hong , Ma Hui-Liang , Lin Jia-Bing , Liang Wen-Yan , Yang Yu-Lian
Published: August 2020

Simultaneous bandwidth (BW) enhancement and time-delay signature (TDS) suppression of chaotic lasing over a wide range of parameters by mutually coupled semiconductor lasers (MCSLs) with random optical injection are proposed and numerically investigated. The influences of system parameters on TDS suppression (characterized by autocorrelation function (ACF) and permutation entropy (PE) around characteristic time) and chaos BW are investigated. The results show that, with the increasing bias current, the ranges of parameters (detuning and injection strength) for the larger BW (> 20 GHz) are broadened considerably, while the parameter range for optimized TDS (< 0.1) is not shrunk obviously. Under optimized parameters, the system can simultaneously achieve two chaos outputs with enhanced BW (> 20 GHz) and perfect TDS suppression. In addition, the system can generate two-channel high-speed truly physical random number sequences at 200 Gbits/s for each channel.
Magnetoelastic coupling effect of Fe10Co90 films grown on different flexible substrates*
Authors: Zhao Jiapeng , Guo Qinhuang , Yin Huizhong , Zou Jintang , Zhao Zhenjie , Cheng Wenjuan , Jiang Dongmei , Zhan Qingfeng
Published: August 2020

The magneto–mechanical coupling effect and magnetic anisotropy of Fe10Co90 (FeCo) films deposited on silicon wafer (Si), flexible polyethylene terephthalate (PET), freestanding polydimethylsiloxane (PDMS), and pre-stretched 20% PDMS substrates were studied in detail. The loop squareness ratio M
r/M
s and the coercive H
c of the FeCo film grown on a PET substrate can be obviously tuned by applying a small tensile-bending strain, and those of the FeCo film grown on a freestanding PDMS substrate can only be slightly changed when applying a relatively large tensile bending strain. For the FeCo film prepared on a 20% pre-stretched PDMS, a wrinkled morphology is obtained after removing the pre-strain. The wrinkled FeCo film can keep the magnetic properties unchanged when applying a relatively large tensile bending strain perpendicular to the wrinkles. This reveals that PDMS is an ideal substrate for magnetic films to realize flexible immutability. Our results may help for developing flexible magnetic devices.