bluuebunny/crossref_metadata_2025 huggingface dataset:
Microendoscopy detects altered muscular contractile dynamics in a mouse model of amyotrophic lateral sclerosis
Authors: Chen Xuefeng , Sanchez Gabriel N. , Schnitzer Mark J. , Delp Scott L.
Published: January 2020

Amyotrophic lateral sclerosis (ALS) is a fatal disease involving motor neuron degeneration. Effective diagnosis of ALS and quantitative monitoring of its progression are crucial to the success of clinical trials. Second harmonic generation (SHG) microendoscopy is an emerging technology for imaging single motor unit contractions. To assess the potential value of microendoscopy for diagnosing and tracking ALS, we monitored motor unit dynamics in a B6.SOD1G93A mouse model of ALS for several weeks. Prior to overt symptoms, muscle twitch rise and relaxation time constants both increased, consistent with a loss of fast-fatigable motor units. These effects became more pronounced with disease progression, consistent with the death of fast fatigue-resistant motor units and superior survival of slow motor units. From these measurements we constructed a physiological metric that reflects the changing distributions of measured motor unit time constants and effectively diagnoses mice before symptomatic onset and tracks disease state. These results indicate that SHG microendoscopy provides a means for developing a quantitative, physiologic characterization of ALS progression.
Radio-Frequency Electromagnetic Field Exposure of Western Honey Bees
Authors: Thielens Arno , Greco Mark K. , Verloock Leen , Martens Luc , Joseph Wout
Published: January 2020

Radio-frequency electromagnetic fields (RF-EMFs) can be absorbed in all living organisms, including Western Honey Bees (Apis Mellifera). This is an ecologically and economically important global insect species that is continuously exposed to environmental RF-EMFs. This exposure is studied numerically and experimentally in this manuscript. To this aim, numerical simulations using honey bee models, obtained using micro-CT scanning, were implemented to determine RF absorbed power as a function of frequency in the 0.6 to 120 GHz range. Five different models of honey bees were obtained and simulated: two workers, a drone, a larva, and a queen. The simulations were combined with in-situ measurements of environmental RF-EMF exposure near beehives in Belgium in order to estimate realistic exposure and absorbed power values for honey bees. Our analysis shows that a relatively small shift of 10% of environmental incident power density from frequencies below 3 GHz to higher frequencies will lead to a relative increase in absorbed power of a factor higher than 3.
Clinical characteristics and treatment outcome of oropharyngeal squamous cell carcinoma in an endemic betel quid region
Authors: Chen Tseng-Cheng , Wu Chen-Tu , Ko Jenq-Yuh , Yang Tsung-Lin , Lou Pei-Jen , Wang Cheng-Ping , Chang Yih-Leong
Published: January 2020

The clinical characteristics of oropharyngeal squamous cell carcinoma (OPSCC) may be different between endemic and non-endemic regions of betel nut chewing. The impact of combined alcohol drinking/betel quid chewing/cigarette smoking (ABC) exposure on the survival of OPSCC remains unclear. We reviewed the medical records of OPSCC patients between 1999 and 2013. Immunohistochemical staining of p16 and HPV genotype detection by DNA Polymerase chain reaction were both performed for each tumor. A total of 300 eligible patients including 74 HPV+ OPSCC patients and 226 HPV− OPSCC patients were enrolled. The 5-year disease-free survival rates for the HPV−, HPV+ OPSCC with and without ABC patients were 49.8%, 58.4% and 94%, respectively. The 5-year overall survival rates for the patients with HPV−, HPV+ OPSCC with and without ABC patients were 46%, 57.4% and 86%, respectively. Advanced locoregionally disease (T3/T4, N2/N3), HPV- OPSCC, combined 2 or all ABC exposure were the independent adverse prognostic factors for disease-free and overall survival. Therefore, our data suggest that in an endemic region of betel quid chewing, HPV− OPSCC comprises the majority of OPSCC and has a worse survival. Combined 2 or all ABC exposure had a significant negative impact on disease-free and overall survival.
Distinct capabilities of different Gammaproteobacterial strains on utilizing small peptides in seawater
Authors: Liu Shuting , Liu Zhanfei
Published: January 2020

Proteins and peptides account for 20–75% of marine biota biomass, of which a major fraction is metabolized by bacteria, thus deciphering interactions between bacteria and peptides is important in understanding marine carbon and nitrogen cycling. To better understand capabilities of different bacterial strains on peptide decomposition, four Gammaproteobacteria (Pseudoalteromonas atlantica, Alteromonas sp., Marinobacterium jannaschii, Amphritea japonica) were incubated in autoclaved seawater amended with tetrapeptide alanine-valine-phenylalanine-alanine (AVFA), a fragment of RuBisCO. While AVFA was decomposed greatly by Pseudoalteromonas atlantica and Alteromonas sp, it remained nearly intact in the Marinobacterium jannaschii and Amphritea japonica incubations. Pseudoalteromonas and Alteromonas decomposed AVFA mainly through extracellular hydrolysis pathway, releasing 71–85% of the AVFA as hydrolysis products to the surrounding seawater. Overall, this study showed that Gammaproteobacterial strains differ greatly in their capabilities of metabolizing peptides physiologically, providing insights into interactions of bacteria and labile organic matter in marine environments.
Increased frequency of PD-1hiCXCR5- T cells and B cells in patients with newly diagnosed IgA nephropathy
Authors: Wang Xin , Li Tao , Si Rui , Chen Jinyun , Qu Zhihui , Jiang Yanfang
Published: January 2020

Recent research has identified a population of PD-1hiCXCR5− ‘peripheral helper’ T (Tph) cells that simulate plasma cell differentiation by interactions between IL-21 and SLAMF5. However, the alteration of circulating Tph and CD138+ B in IgA nephropathy (IgAN) remains poorly understood. Flow cytometry analysis was used to measure the frequency of circulating PD-1hiCXCR5− T cells and CD138+ B cells in 37 patients with IgAN and 23 healthy controls (HCs). Estimated glomerular filtration rate (eGFR), 24 h urinary protein and serum cytokine concentrations were measured. The percentage of different subsets of circulating PD-1hiCXCR5− T cells and CD138+ B cells were significantly higher in patients with IgAN compared to HCs. Pretreatment, the percentage of different subsets of circulating PD-1hiCXCR5− T cells and CD138+ B cells were negatively correlated with eGFR, the percentage of circulating CD138+ B cells was positively correlated with 24-h urinary protein concentration, and the percentage of circulating PD-1hiCXCR5−, CD28+ and ICOS+ T cells. Posttreatment, the percentage of different subsets of circulating PD-1hiCXCR5− T cells and CD138+ B cells and serum IL-21 concentration were significantly reduced. Different subsets of circulating PD-1hiCXCR5− T cells contribute to the progression and pathogenesis of IgAN by regulating the differentiation of CD138+ B cells through a combination of surface molecules.
Cross section measurements of 151Eu(3He,5n) reaction: new opportunities for medical alpha emitter 149Tb production
Authors: Moiseeva A. N. , Aliev R. A. , Unezhev V. N. , Zagryadskiy V. A. , Latushkin S. T. , Aksenov N. V. , Gustova N. S. , Voronuk M. G. , Starodub G. Ya. , Ogloblin A. A.
Published: January 2020

Method for production of alpha emitter 149Tb by irradiation of 151Eu with 70 MeV 3He nuclei is proposed. For the first time, the cross sections for the formation of isotopes 149,150,151,152Tb were measured experimentally using a stack foil technique in the 3He particles energy range 70 → 12 MeV. The thick target yield of 149Tb is 39 MBq/μAh, or 230 MBq/μA 149Tb at saturation. The optimal energy range from the point of view of radioisotopic purity is 70 → 40 MeV. At these conditions about 150 MBq/μA 149Tb can be produced in 8 hours irradiation, which is sufficient for therapeutic applications. The main impurities are 150Tb (~100% in activity) and 151Tb (~30% in activity). The proposed method surpasses its counterparts by the high content of the target isotope in the natural mixture and the simplicity of the radiochemical separation of 149Tb from the bulk target material.
Phytoavailability of bound residue of Carbendazim to Chinese cabbage (Brassica campestris ssp.chinensis) coexisted with Superabsorbent polymers
Authors: Yang Yatian , Wang Haiyan , Li Wei , Chen Yan , Guo Wei , Gu Xin , Ye Qingfu
Published: January 2020

Understanding the bioavailability and phytotoxicity of Carbendazim (MBC) bound residues (BR) in soils incubated with different Superabsorbent polymer (SAP) amendment on succeeding crops is essential to assess their environmental fate and risks. In our research, we studied the morphological characteristics and 14C-accumulation of Chinese cabbage and released BR in three typical cultivated soils. The plant dry weight was in order of superabsorbent-hydrogels formulations (HMBC) > MBC > MBC and SAP (MBC-SAP) at 35 d in basic soil 3 (S3), with 675.40 ± 29.07 mg/plant.d.w, 575.93 ± 25.35 mg/plant.d.w and 427.86 ± 18.79 mg/plant.d.w. The whole plant accumulated 2-fold more BR when grew in neutral soil 2 (S2) treated with SAP than MBC at 7 d. The root accumulated a greater proportion of 14C-MBC residue than shoot, with order of MBC-SAP > MBC > HMBC at 21d. The results indicate MBC-BR could be released and accumulated in plant. HMBC promoted the Chinese cabbage growth with lowest 14C accumulation, while MBC-SAP inhibited plant growth with the highest 14C uptake. The released BR rate was 61.43 ± 3.75% of initial BR in MBC-SAP, with 2-fold higher than MBC and HMBC. It is assumed HMBC could be a potential environmentally friendly measure for rational use of pesticides in future.
Author Correction: Biological parameters, life table and thermal requirements of Thaumastocoris peregrinus (Heteroptera: Thaumastocoridae) at different temperatures
Authors: Barbosa L. R. , Santos F. , Soliman E. P. , Rodrigues A. P. , Wilcken C. F. , Campos J. M. , Zanuncio A. J. V. , Zanuncio J. C.
Published: January 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Warming and drying over the central Himalaya caused by an amplification of local mountain circulation
Authors: Norris Jesse , Carvalho Leila M. V. , Jones Charles , Cannon Forest
Published: January 2020

Climatic changes over the central Himalaya are critical for water resources in downstream regions where hundreds of millions of people live. Warming and drying in this region have both occurred in recent decades, but the associated meteorological factors are difficult to diagnose based on observations from unevenly distributed weather stations, reanalyses, and global climate models that poorly reproduce the orographic diurnal cycle. Here, recent trends in the summer diurnal cycle over the central Himalaya are investigated using a 36-year high-resolution dynamical downscaling. We illustrate contrasting trends over the diurnal cycle of circulation and convection over the Himalaya. In the daytime, warming of the slopes has enhanced anabatic upslope winds. At night, clearer skies have radiatively cooled the slopes, enhancing katabatic downslope winds. The enhanced upslope winds have prevented any drying over the mountains in the daytime, while the enhanced downslope winds are associated with significant nocturnal drying at high elevations. This amplification in the diurnal cycle is critical for projecting the future hydroclimate over the region’s complex terrain.
Embedding oxygen vacancies at SnO2–CNT surfaces via a microwave polyol strategy towards effective electrocatalytic reduction of carbon-dioxide to formate
Authors: Pavithra Kumaravelu , Kumar Sakkarapalayam Murugesan Senthil
Published: January 2020

A facile and scalable microwave-polyol method has been utilised to introduce vacancies onto SnO2–CNT surfaces which significantly brings down the overpotential to around 150 mV during the electrochemical reduction of CO2.
A direct Z-scheme ZnS/Co9S8 heterojunction-based photoelectrochemical sensor for the highly sensitive and selective detection of chlorpyrifos
Authors: Chen Shi-Hua , Xiao Xiang-Yu , Li Pei-Hua , Li Yi-Xiang , Yang Meng , Guo Zheng , Huang Xing-Jiu
Published: January 2020

A direct Z-scheme ZnS/Co9S8 heterojunction-based photoelectrochemical sensor for analyzing organophosphorus chlorpyrifos.
What will happen when microorganisms “meet” photocatalysts and photocatalysis?
Authors: Deng Yaocheng , Li Zaiyun , Tang Rongdi , Ouyang Kai , Liao Chanjuan , Fang Yi , Ding Chunxia , Yang Lihua , Su Long , Gong Daoxin
Published: January 2020

In recent years, photocatalytic technology has been widely studied as an environmental restoration technology and energy production technology to solve the two crises of energy shortage and environmental pollution.
Supply of methionine and arginine alters phosphorylation of mechanistic target of rapamycin (mTOR), circadian clock proteins, and α-s1-casein abundance in bovine mammary epithelial cells
Authors: Hu Liangyu , Chen Yifei , Cortes Ismael M. , Coleman Danielle N. , Dai Hongyu , Liang Yusheng , Parys Claudia , Fernandez Carlos , Wang Mengzhi , Loor Juan J.
Published: January 2020

Methionine (Met) and arginine (Arg) regulate casein protein abundance through alterations in activity of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway.
Covalently functionalized uniform amino-silica nanoparticles. Synthesis and validation of amine group accessibility and stability
Authors: Miller Peter J. , Shantz Daniel F.
Published: January 2020

This paper describes the synthesis and characterization of stable, 18 nm silica nanoparticles that are functionalized with amine groups.
Scalable synthesis of colloidal CsPbBr3 perovskite nanocrystals with high reaction yields through solvent and ligand engineering
Authors: Ng Chun Kiu , Yin Wenping , Li Hanchen , Jasieniak Jacek J.
Published: January 2020

Application of green chemistry to obtain 70% reaction yields of high quality CsPbBr3 perovskite nanocrystals through solvent and ligand engineering.
Fluorinated vesicles embedded with Ru-based catalysts as efficient and recyclable nanoreactors for photo-mediated aerobic oxidation
Authors: Que Yurong , Ruan Junyi , Xiao Yan , Feng Chun , Lu Guolin , Huang Xiaoyu
Published: January 2020

This article reports a versatile platform to prepare efficient nanoreactors containing a variety of catalysts for diverse reactions, especially for aerobic oxidation.
The suppression of lithium dendrites by a triazine-based porous organic polymer-laden PEO-based electrolyte and its application for all-solid-state lithium batteries
Authors: Angulakshmi N. , Dhanalakshmi R. Baby , Kathiresan Murugavel , Zhou Yingke , Stephan A. Manuel
Published: January 2020

A triazene-p-phenylenediamine-based porous organic polymer (TP-POP) was successfully synthesized and incorporated as a filler in the PEO + LiTFSI matrix.
Correction: Cyclo[18]carbon: the smallest all-carbon electron acceptor
Authors: Stasyuk Anton J. , Stasyuk Olga A. , Solà Miquel , Voityuk Alexander A.
Published: January 2020

Correction for ‘Cyclo[18]carbon: the smallest all-carbon electron acceptor’ by Anton J. Stasyuk et al., Chem. Commun., 2020, 56, 352–355.
Highly Efficient Synthesis of Hindered 3-Azoindoles via Metal-Free C–H Functionalization of Indoles
Authors: Jacob Nicolas , Guillemard Lucas , Wencel-Delord Joanna
Published: January 2020

Although 3-azoindoles have recently emerged as an appealing family of photoswitch molecules, the synthesis of such compounds has been poorly covered in the literature. Herein a high-yielding and operationally simple protocol is reported allowing the synthesis of 3-azoindoles, featuring important steric hindrance around the azo motif. Remarkably, this C–H coupling is characterized by excellent atom economy and occurs under metal-free conditions, at room temperature, and within few minutes, delivering the expected products in excellent yields (quantitatively in most of the cases). Accordingly, a library of new molecules, with potential applications as photochromic compounds, is prepared.
Effects of melatonin on the proliferation and differentiation of rat adipose-derived stem cells
Authors: Zaminy Arash , Kashani Iraj Ragerdi , Barbarestani Mohammad , Hedayatpour Azim , Mahmoudi Reza , Vardasbi Safoura , Shokrgozar Mohammad Ali
Published: January 2020

Background: Osteogenesis driven by adipose-derived stem cells (ADSCs) is regulated by physiological and pathological factors. Accumulating evidence from in vitro and in vivo experiments suggests that melatonin may have an influence on bone formation. However, little is known about the effects of melatonin on osteogenesis, which thus remains to be elucidated. This study was performed to determine whether melatonin at physiological concentrations (0.01-10 nM) could affect the in vitro proliferation and osteogenic differentiation of rat ADSCs.Materials and Methods: ADSCs were isolated from the fat of adult rats. After cell expansion in culture media and through three passages, osteogenesis was induced in a monolayer culture using osteogenic medium with or without melatonin at physiological concentrations (0.01-10 nM). After four weeks, the cultures were examined for mineralization by Alizarin Red S and von Kossa staining and for alkaline phosphatase (ALP) activity using an ALP kit. Cell viability and apoptosis were also assayed by 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTT) assay and flow cytometry, respectively.Results: The results indicated that at physiological concentrations, melatonin suppressed proliferation and differentiation of ADSCs. These data indicate that ADSCs exposed to melatonin, had a lower ALP activity in contrast to the cells exposed to osteogenic medium alone. Similarly, mineral deposition (calcium level) also decreased in the presence of melatonin. Flow cytometry confirmed that cell growth had decreased and that the numbers of apoptotic cells had increased.Conclusion: These results suggest that the physiological concentration of melatonin has a negative effect on ADSC osteogenesis.
Lock-and-Key Exciplexes for Thermally Activated Delayed Fluorescence
Authors: Voll Constantin-Christian A. , Markopoulos Georgios , Wu Tony C. , Welborn Matthew , Engelhart Jens U. , Rochat Sébastien , Han Grace G. D. , Sazama Graham T. , Lin Ting-An , Van Voorhis Troy , Baldo Marc A. , Swager Timothy M.
Published: January 2020

We combine synthetic supramolecular chemistry and materials science to develop novel exciplexes for thermally activated delayed fluorescence. Our approach starts from a bowl-shaped acceptor molecule for which we synthesize tailor-made donors that bind in a lock-and-key fashion. The donor design is guided by extensive density functional theory calculations of three independent donor families. The investigation of a large number of custom-synthesized donors allows us to derive empirical relationships for the prediction of the exciplex emission color. Incorporated within organic light-emitting devices, the lock-and-key exciplexes yield external quantum efficiencies of up to 5.4%, with potentially tunable emission color across the blue and green visible spectrum.
Effect of Smoking Cessation on the Pharmacokinetics and Pharmacodynamics of Clopidogrel after PCI: The Smoking Cessation Paradox Study
Authors: Ramotowski Bogumił , Gurbel Paul A. , Tantry Udaya , Bracha Jan S. , Karaźniewicz-Łada Marta , Lewandowski Zbigniew , Budaj Andrzej
Published: January 2020

Background Cigarette smoking is associated with enhanced clopidogrel effect and platelet inhibition. However, the effect of smoking cessation on clopidogrel pharmacokinetics (PK) and pharmacodynamics (PD) is unknown. We aimed to determine the effect of smoking cessation, confirmed by cotinine measurement, on clopidogrel PK and PD after percutaneous coronary intervention (PCI).

Methods and Results Following successful PCI, patients treated with 75 mg/day clopidogrel who reported smoking ≥10 cigarettes/day with NicAlert urine cotinine level 6 were enrolled. Clopidogrel and its metabolite concentrations, VerifyNow P2Y12 reaction units (PRUs), and NicAlert levels were measured in the study group before and at 30 days after smoking cessation and in a control group. CYP1A2 and CYP2C19 genotypes were determined. At 30-day visit (n = 87), 45 patients continued smoking, whereas 42 patients stopped smoking. Baseline PRUs were similar between groups. At 30 days, the smoking cessation group had higher PRUs (150.5 ± 68.6 vs. 118.4 ± 65.9, p = 0.03), greater absolute PRU change (27.7 ± 39.8 vs. −12.9 ± 55.4, p = 0.0002), greater change of PRUs adjusted for baseline platelet reactivity (38.6 ± 10.0, p < 0.01), greater risk of high platelet reactivity (HPR) (odds ratio: 10.14 [1.52–67.5], p = 0.017), and a trend towards decreased H3 clopidogrel metabolite levels (−3.41 ng/mL [−11.00 to 0.54 ng/mL], p = 0.072). CYP2C19 LoF carriers who stopped smoking had the highest PRUs, whereas those with the wild type who continued smoking had the lowest PRUs (p < 0.008).

Conclusion Smoking cessation in clopidogrel-treated patients after PCI is associated with increased platelet reactivity and greater risk of HPR. Alternative P2Y12 inhibitors may be considered in selected patients who stop smoking after PCI.
Disk-shaped magnetic particles for cancer therapy
Authors: Goiriena-Goikoetxea M. , Muñoz D. , Orue I. , Fernández-Gubieda M. L. , Bokor J. , Muela A. , García-Arribas A.
Published: January 2020

Magnetic disks are a new generation of nanoparticles with outstanding properties to face biomedical challenges as a cancer treatment. The key features of their suitability are the ability of rotation (torque), the high dispersion capability, and the easy manipulation under low magnetic fields. These properties make disk-shaped particles ideal magnetomechanical actuators to damage cancer cell integrity, deliver antitumor drugs, generate heat (magnetic hyperthermia), or separate cancer cells for early detection. Since the experimental demonstration of the capability of destroying brain cancer cells by the force exerted from rotating Ni80Fe20 microdisks, important advances have been reported on disks composed of different magnetic materials and dimensions. Here, we present the evolution of a decade-old research field by combining the discussion of in vitro experiments available in the literature with our most recent results. More importantly, we compare the torque and dispersion capability of each type of magnetic disk in order to promote the investigation toward the most efficient magnetomechanical actuator to destroy cancer cells.
Quality factor tuning of micromechanical resonators via electrical dissipation
Authors: Bousse Nicholas E. , Miller James M. L. , Kwon Hyun-Keun , Vukasin Gabrielle D. , Kenny Thomas W.
Published: January 2020

Sensitive capacitive transduction of micromechanical resonators can contribute significant electrical dissipation, which degrades the quality factor of the eigenmodes. We theoretically and experimentally demonstrate a scheme for isolating the electrical damping of a mechanical resonator due to Ohmic dissipation in the readout amplifier. The quality factor suppression arising from the amplifier is strongly dependent on the amplifier feedback resistance and parasitic capacitance. By studying the thermomechanical displacement noise spectrum of a doubly clamped micromechanical beam, we confirm that electrical dissipation tunes the actual, not effective, quality factor. Electrical dissipation is an important consideration in the design of sensitive capacitive displacement transducers, which are a key component in resonant sensors and oscillators.
New developments in high-pressure X-ray diffraction beamline for diamond anvil cell at SPring-8
Authors: Hirao N. , Kawaguchi S. I. , Hirose K. , Shimizu K. , Ohtani E. , Ohishi Y.
Published: January 2020

An overview of the recently renovated high-pressure X-ray diffraction (XRD) BL10XU beamline for the diamond anvil cell at SPring-8 is presented. The renovation includes the replacement of the X-ray source and monochromator, enhanced focusing systems for high-energy XRD, and recent progress in the sample environment control techniques that are available for high-pressure studies. Other simultaneous measurement techniques for combination with XRD, such as Raman scattering spectroscopy and Mössbauer spectroscopy, have been developed to obtain complementary information under extreme conditions. These advanced techniques are expected to make significant contributions to in-depth understanding of various and complicated high-pressure phenomena. The experience gained with the BL10XU beamline could help promote high-pressure research in future synchrotron radiation facilities.
Peculiarities of escape kinetics in the presence of athermal noises
Authors: Capała Karol , Dybiec Bartłomiej , Gudowska-Nowak Ewa
Published: January 2020

Stochastic evolution of various dynamic systems and reaction networks is commonly described in terms of noise assisted escape of an overdamped particle from a potential well, as devised by the paradigmatic Langevin equation in which additive Gaussian stochastic force reproduces effects of thermal fluctuations from the reservoir. When implemented for systems close to equilibrium, the approach correctly explains the emergence of the Boltzmann distribution for the ensemble of trajectories generated by the Langevin equation and relates the intensity of the noise strength to the mobility. This scenario can be further generalized to include effects of non-Gaussian, burstlike forcing modeled by Lévy noise. In this case, however, the pulsatile additive noise cannot be treated as the internal (thermal) since the relation between the strength of the friction and variance of the noise is violated. Heavy tails of Lévy noise distributions not only facilitate escape kinetics, but also, more importantly, change the escape protocol by altering the final stationary state to a non-Boltzmann, nonequilibrium form. As a result, contrary to the kinetics induced by a Gaussian white noise, escape rates in environments with Lévy noise are determined not by the barrier height, but instead by the barrier width. We further discuss consequences of simultaneous action of thermal and Lévy noises on statistics of passage times and population of reactants in double-well potentials.
Existence and stability of skyrmion bags in thin magnetic films
Authors: Kind Charles , Friedemann Sven , Read Dan
Published: January 2020

Skyrmion bags are spin textures of any integer topological degree, realized in micromagnetic simulations and experimentally in liquid crystals. They have been proposed as a promising new form of magnetic data storage due to their stability with respect to perturbations and the possibility of encoding different values in topologically distinct magnetization configurations. We simulate skyrmion bags in magnetic thin films having a range of physically realistic material parameters. The results give a range over which stable skyrmion bags may be found in experiment, and we extract a relationship to help guide the production of these potentially useful quasiparticles.
Oxygen octahedral tilt ordering in (Na1/2Bi1/2)TiO3 ferroelectric thin films
Authors: Pramanick A. , Paterson A. R. , Denis L. , Abbas W. , Niu G. , Ren W. , Zhao J. , Dai L. , Borkiewicz O. , Ren Y. , Ho D. , Trolier-McKinstry S. , Jones J. L.
Published: January 2020

Oxygen octahedra tilt (OOT) transition is the most common type of distortion in inorganic ABO3 compounds with a perovskite crystal structure. The importance of OOT transitions is underlined by accompanying changes in the B-O and A-O bonding environments, which consequently affects the electronic states and hence influences electrical, magnetic, and superconducting properties of many perovskite compounds. In recent years, controlled manipulation of the OOT order in perovskite thin film ferroelectrics has been attempted through heteroepitaxial strain engineering. The current study demonstrates an alternative approach whereby OOT ordering in a 200 nm thick polycrystalline thin film of (Na1/2Bi1/2)TiO3 (NBT) Pb-free ferroelectric is induced by applying electric-field along the 111 octahedral tilt axis, which is furthermore enabled by a strong (111) crystallographic texture normal to the film surface. In situ x-ray diffraction reveals that electric-field-induced OOT ordering proceeds through nucleation and rapid growth of domains with ordered a−a−a− tilting, followed by an increase in the tilt angle within the ordered domains.
Noise in stimulated Raman scattering measurement: From basics to practice
Authors: Audier X. , Heuke S. , Volz P. , Rimke I. , Rigneault H.
Published: January 2020

We revisit laser intensity noise in the context of stimulated Raman scattering (SRS), which has recently proved to be a key technique to provide label free images of chemical bonds in biological and medical samples. Contrary to most microscopy techniques, which detect a weak photon flux resulting from light matter interactions, SRS is a pump-probe scheme that works in the high flux regime and happens as a weak modulation (10−4–10−6) in a strong laser field. As a result, laser noise is a key issue in SRS detection. This practical tutorial provides the experimentalists with the tools required to assess the amount of noise and the ultimate SRS detection limit in a conventional lock-in-based SRS system. We first define the quantities that are relevant when discussing intensity noise and illustrate them through a conventional model of light detection by a photodiode. SRS is then introduced in its lock-in-based implementation, and the model presented is adapted in this particular case. The power spectral density, relative intensity noise (RIN), signal to noise ratio, and sensitivity of the system are derived and discussed. Two complementary methods are presented that allow measurement of the RIN and assessment of the performance of a SRS system. Such measurements are illustrated on two commercial laser systems. Finally, the consequences of noise in SRS are discussed, and future developments are suggested. The presentation is made simple enough for undergraduate students, graduate students, and newcomers in the field of stimulated Raman and more generally in pump-probe based schemes.
Automatic error control during forward flux sampling of rare events in master equation models
Authors: Klein Max C. , Roberts Elijah
Published: January 2020

Enhanced sampling methods, such as forward flux sampling (FFS), have great capacity for accelerating stochastic simulations of nonequilibrium biochemical systems involving rare events. However, the description of the tradeoffs between simulation efficiency and error in FFS remains incomplete. We present a novel and mathematically rigorous analysis of the errors in FFS that, for the first time, covers the contribution of every phase of the simulation. We derive a closed form expression for the optimally efficient count of samples to take in each FFS phase in terms of a fixed constraint on sampling error. We introduce a new method, forward flux pilot sampling (FFPilot), that is designed to take full advantage of our optimizing equation without prior information or assumptions about the phase weights and costs along the transition path. In simulations of both single and multidimensional gene regulatory networks, FFPilot is able to completely control sampling error. We then discuss how memory effects can introduce additional error when relaxation along the transition path is slow. This extra error can be traced to correlations between the FFS phases and can be controlled by monitoring the covariance between them. Finally, we show that, in sets of simulations with matched error, FFPilot is on the order of tens-to-hundreds of times faster than direct sampling and noticeably more efficient than previous FFS methods.
Magnetic motion of biogenic guanine crystal plate combined with Fe2O3 nanoparticles
Authors: Nagai Ryosuke , Kurahashi Masaru , Kishimoto Kengo , Koyanagi Tsuyoshi , Iwasaka Masakazu , Asada Hironori
Published: January 2020

To reduce the magnetic field amplitude required to orient guanine crystal plates, we have attached magnetic nanoparticles to these guanine crystal plates. Fe2O3 nanoparticles are mixed with the guanine crystal plates, which are dispersed in water. Observation by optical microscopy confirmed that the large particles, which are nanoparticle aggregates, attach preferentially to the side edges of the guanine crystal plates. The individual crystal plate surfaces show clear, undisturbed light interference patterns, which mean that each plate’s optical properties have been maintained. The magnetic orientation experiments of these guanine crystal plates with different numbers of optically observed particles are conducted under both in-plane and vertical magnetic fields. The positions of the attached particles do not change, even when the magnetic field is applied. In these experiment, it was difficult to align the crystal direction with the magnetic field direction because the magnetic orientation characteristics are strongly affected by the positions and numbers of the attached particles. However, in-plane rotation and an increased tilt angle are achieved for the guanine crystal plates using magnetic fields of several millitesla.
Magnetic field effect on recombination of radicals diffusing on a two-dimensional plane
Authors: Lukzen Nikita N. , Ivanov Konstantin L. , Sadovsky Vladimir M. , Sagdeev Renad Z.
Published: January 2020

Magnetic Field Effects (MFEs) on the recombination of radicals, which diffuse on an infinite plane, are studied theoretically. The case of spin-selective diffusion-controlled recombination of Radical Pairs (RPs) starting from a random spin state is considered assuming uniform initial distribution of the radicals. In this situation, reaction kinetics is described by a time-dependent rate coefficient K(t), which tends to zero at long times. Strong MFEs on K(t) are predicted that originate from the Δg and hyperfine driven singlet-triplet mixing in the RP. The effects of spin relaxation on the magnetic field are studied, as well as the influence of the dipole-dipole interaction between the electron spins of the RP. In the two-dimensional case, this interaction is not averaged out by diffusion and it strongly affects the MFE. The results of this work are of importance for interpreting MFEs on lipid peroxidation, a magnetosensitive process occurring on two-dimensional surfaces of cell membranes.
Thermal transport properties of GaN with biaxial strain and electron-phonon coupling
Authors: Tang Dao-Sheng , Qin Guang-Zhao , Hu Ming , Cao Bing-Yang
Published: January 2020

Strain inevitably exists in practical GaN-based devices due to the mismatch of lattice structure and thermal expansion brought by heteroepitaxial growth and band engineering, and it significantly influences the thermal properties of GaN. In this work, thermal transport properties of GaN considering the effects from biaxial strain and electron-phonon coupling (EPC) are investigated using the first principles calculation and phonon Boltzmann transport equation. The thermal conductivity of free GaN is 263 and 257 W/mK for in-plane and cross-plane directions, respectively, which are consistent better with the experimental values in the literature than previous theoretical reports and show a nearly negligible anisotropy. Under the strain state, thermal conductivity changes remarkably. In detail, under +5% tensile strain state, average thermal conductivity at room temperature decreases by 63%, while it increases by 53% under the −5% compressive strain, which is mostly attributed to the changes in phonon relaxation time. Besides, the anisotropy of thermal conductivity changes under different strain values, which may result from the weakening effect from strain induced piezoelectric polarization. EPC is also calculated from the first principles method, and it is found to decrease the lattice thermal conductivity significantly. Specifically, the decrease shows significant dependence on the strain state, which is due to the relative changes between phonon-phonon and electron-phonon scattering rates. Under a compressive strain state, the decreases of lattice thermal conductivity are 19% and 23% for in-plane and cross-plane conditions, respectively, comparable with those under a free state. However, the decreases are small under the tensile strain state, because of the decreased electron-phonon scattering rates and increased phonon anharmonicity.
Glycosidic linkage flexibility: The ψ torsion angle has a bimodal distribution in α-L-Rhap-(1→2)-α-L-Rhap-OMe as deduced from 13C NMR spin relaxation
Authors: Zerbetto Mirco , Polimeno Antonino , Widmalm Göran
Published: January 2020

The molecular dynamics (MD) computer simulation technique is powerful for the investigation of conformational equilibrium properties of biomolecules. In particular, free energy surfaces of the torsion angles (those degrees of freedom from which the geometry mostly depends) allow one to access conformational states, as well as kinetic information, i.e., if the transitions between conformational states occur by simple jumps between wells or if conformational regions close to these states also are populated. The information obtained from MD simulations may depend substantially on the force field employed, and thus, a validation procedure is essential. NMR relaxation data are expected to be highly sensitive to the details of the torsional free energy surface. As a case-study, we consider the disaccharide α-l-Rhap-(1 → 2)-α-l-Rhap-OMe that features only two important torsion angles, ϕ and ψ, which define the interglycosidic orientation of the sugar residues relative to each other, governed mainly by the exo-anomeric effect and steric interactions, respectively. In water, a ψ− state is preferred, whereas in DMSO, it is a ψ+ state, suggesting inherent flexibility at the torsion angle. MD simulations indicated that bistable potentials describe the conformational region well. To test whether a unimodal distribution suffices or if a bimodal distribution better represents molecular conformational preferences, we performed an alchemical morphing of the torsional free energy surface and computed T1, T2, and NOE 13C NMR relaxation data that were compared to experimental data. All three NMR observables are substantially affected by the morphing procedure, and the results strongly support a bimodal Boltzmann equilibrium density with a major and a minor conformational state bisected at ψ ≈ 0°, in accord with MD simulations in an explicit solvent.
Through-substrate terahertz time-domain reflection spectroscopy for environmental graphene conductivity mapping
Authors: Lin Hungyen , Burton Oliver J. , Engelbrecht Sebastian , Tybussek Kai-Henning , Fischer Bernd M. , Hofmann Stephan
Published: January 2020

We demonstrate how terahertz time-domain spectroscopy (THz-TDS) operating in reflection geometry can be used for quantitative conductivity mapping of large area chemical vapor deposited graphene films through silicon support. We validate the technique against measurements performed using the established transmission based THz-TDS. Our through-substrate approach allows unhindered access to the graphene top surface and thus, as we discuss, opens up pathways to perform in situ and in-operando THz-TDS using environmental cells.
Enhancement of perpendicular magnetic anisotropy of ferromagnet/oxide heterointerface by an oxygen-dependent orbital modulation
Authors: Meng Fei , Feng Chun , Wang Lei , Li Yukun , Yao Mingke , Xu Xiulan , Li Baohe , Hu Qiang , Hu Lang , Yu Guanghua
Published: January 2020

Tailoring the magnetic anisotropy of a ferromagnet film is the critical issue to construct high-efficient magnetic memory and logic devices. In this paper, we demonstrated a controllable magnetic anisotropy of Pt/Co/HfO2 multilayers by tuning the oxygen-dependent orbital occupancy at the Co/HfO2 interface. Driven by the large difference in formation enthalpy between HfO2 with CoO, an effective O2− migration occurred at the Co/HfO2 interface by thermal activation, which increased the electronic occupation on the Co 3dz2 orbit and facilitated the out-of-plane Co-O orbital hybridization. Therefore, the interfacial magnetic anisotropy energy was enhanced by two times, leading to a transition from in-plane to out-of-plane anisotropy. Conversely, the O2− migration was suppressed when HfO2 was replaced by ZnO with the formation enthalpy close to CoO, which makes the orbital tunability effect disappear and the magnetic anisotropy of film unchangeable. These findings are crucial for exploiting the magnetoionic control of interfacial magnetism and advancing the functionalized design of memorizers based on orbital engineering.
Hyaluronic acid-based hydrogels show promise as bio-ink in the 3D printing of tissues
Authors: Mandel Savannah
Published: January 2020

Stiffness and bioactivity of biomaterial, thiol-modified hyaluronic acid, is tuned in a cell-friendly system suited to 3D printing and cell encapsulation.
A Two-Dimensional Coordination Polymer Formed from Cobalt(II) and an Extended Dipyridyl Ligand
Authors: AL-Fayaad Hydar A. , Siddique Rashid G. , Arachchige Kasun S. Athukorala , Clegg Jack K.
Published: January 2020

The synthesis of the extended dipyridyl ligand 4,4′-(2,5-dimethyl-1,4-phenylene)dipyridine (L) in an improved yield via the palladium catalysed Suzuki coupling of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (1) and 1,4-dibromo-2,5-dimethylbenzene (2) is reported along with its use to form a two-dimensional coordination polymer [Co2L2(OAc)4(H2O)2]n. The coordination polymer consists of one-dimensional chains of octahedral cobalt ions bridged by acetate ligands which are connected to form two dimensional sheets with square lattice (sql) topology via the dipyridyl ligands (L). The structure contains small voids totalling ~6.6% of the unit cell volume. The crystal structures 1, L, L·2H2O, and L·2HNO3 are also reported.
Reduced sensitivity from pooled urine, pharyngeal and rectal specimens when using a molecular assay for the detection of chlamydia and gonorrhoea near the point of care
Authors: Badman Steven G. , Bell Sara F. E. , Dean Judith A. , Lemoire Jime , Coffey Luke , Debattista Joseph , Redmond Andrew M. , Williams Owain D. , Gilks Charles F. , Whiley David M.
Published: January 2020

Background
The aim of this study was to compare the performance of pooled self-collected urogenital, pharyngeal and anorectal specimens to that of individual specimen results for the molecular detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) near the point of care (POC) for diagnostic sensitivity. Methods: Clients (mostly men who have sex with men) attending an urban community testing service and three sex-on-premises venues in Brisbane, Australia, were offered CT and NG testing by trained lay providers. Participants provided three self-collected specimens (urine, pharyngeal and rectal) for testing by GeneXpert (Cepheid, Sunnyvale, CA, USA). If any of the individual specimens from a participant were positive, all three specimens were pooled and retested. Results: Of the 388 participants who provided three individual anatomical specimens, 76 (19.6%) were found to be positive for CT and/or NG at one or more sites. The pooling approach failed to detect five CT rectal and four NG pharyngeal infections. The overall performance (sensitivity) of the pooling approach compared with individual specimen testing and Cohen’s κ were 90.0% and 0.86 respectively for CT and 89.7% and 0.89 respectively for NG. Conclusions: Reduced sensitivity was observed when using pooled specimens for the detection of CT and NG using GeneXpert near the POC, similar to results reported in laboratory-based CT and NG pooling studies. These data suggest specimen pooling is feasible near to the POC, potentially saving time and costs when screening at-risk populations for CT and NG. Our data also suggest a reduction in pooled urine could improve overall test sensitivity.
Analysis of low sexual desire in Chinese women: a national population-based epidemiological survey in mainland China
Authors: Tong Jiali , Zhang Chunni , Zhang Lei , Xu Tao , Lang Jinghe , Zhu Lan
Published: January 2020

Background
Low sexual desire is the most prevalent female sexual health problem; however, national epidemiologic data on female sexual desire in China are absent. Understanding factors related to low sexual desire are essential in preparing educational and consultative programs and policies to improve women’s sexual health. Methods: A national epidemiological survey on female sexual function was conducted from February 2014 to January 2016 in mainland China. Women were randomly selected using multistage, stratified, cluster sampling. The sexual functioning was assessed by using the Chinese version of the 19-item Female Sexual Function Index (FSFI) questionnaire. Results: The questionnaire on sexual dysfunction was completed by 25446 women who were aged 20–70 years. The prevalence of low sexual desire was 21.6% (domain score ≤4.28), and the declines in sexual desire started as early as 25–29 years. Sexual arousal was most closely related to sexual desire (Pearson’s correlation = 0.760). Higher educational attainment was associated with a decreased risk of low sexual desire. Diabetes, non-gynaecological cancer, pelvic inflammatory disease and pelvic pain had negative effects on sexual desire (OR = 1.44, 99% CI = 1.11–1.87; OR = 1.92, 99% CI = 1.18–3.13; OR = 1.32, 99% CI = 1.07–1.63; OR = 1.77, 99% CI = 1.13–2.76 respectively). Conclusions: The prevalence of low sexual desire in females in China was modest. Low sexual desire is correlated with sexual arousal disorder. Biopsychosocial factors have overlapping effects on sexual desire.
Biosynthesis of silver nanoparticle from pomelo (Citrus Maxima) and their antibacterial activity against acidovorax oryzae RS-2
Authors: Ali Khattak Arif , Yao Rong , Wu Wenge , Masum Md Mahidul Islam , Luo Jinyan , Wang Yanli , Zhang Yang , An Qianli , Sun Guochang , Li Bin
Published: January 2020

Silver nanoparticles (AgNPs), synthesized with plant materials, are considered to be an emerging field of agriculture for their eco-friendly and outstanding antibacterial attributes. In this study, we synthesized AgNPs using pomelo (Citrus maxima) fruit extract as a biological capping and reducing material. The particle size was determined as 11.3–12.8 nm by using UV–vis spectrophotometer, TEM and x-ray diffraction analysis. UV–vis spectrophotometer analysis also confirmed the formation of AgNPs in colloidal solution and showed a maximum absorption at 426 nm. Fourier transform infrared spectra was used to analysed the involvement of biological molecule in AgNPs synthesis. The minimum inhibitory concentration of AgNPs against Acidovorax oryzae strain RS-2 was determined as 25 μg ml−1 by agar well diffusion and bacterial growth assay. In addition, bacterial viability and swarming motility were significantly inhibited by AgNPs. Compared with the control, 25 μg ml−1 of AgNPs lower bacterial biofilm formation up to 68.24%. The bacterial cell wall damaged by AgNPs was observed t TEM. Furthermore, AgNPs treatment resulted into the down regulation of expression of many type VI secretion system related genes, suggesting that AgNPs also have an effect on the virulence of bacteria. The overall conclusion of this study suggests that AgNPs can play an important role in controlling A. oryzae.