bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of low- versus standard-volume bowel preparation on participation in primary screening colonoscopy: a randomized health services study
Authors: Pisera Małgorzata , Franczyk Robert , Wieszczy Paulina , Polkowski Marcin , Rupinski Maciej , Chaber-Ciopinska Anna , Kotowski Bronislaw , Kula Zbigniew , Kielek Slawomir , Buszkiewicz Marek , Rupinska Maria , Kobiela Jaroslaw , Kaminski Michal , Regula Jaroslaw
Published: February 2019

Background The aim of this study was to evaluate the impact of low-volume vs. standard-volume bowel preparation on participation in screening colonoscopy, bowel preparation quality, and lesion detection rates.

Methods This was a multicenter, randomized, health services study within the population-based primary colonoscopy screening program in Poland. Individuals aged 55 – 62 years were randomized in a 1:1 ratio to bowel preparation with a low-volume (0.3 L sodium picosulfate with magnesium citrate) or standard-volume (4 L polyethylene glycol) regimen and then invited to participate in screening colonoscopy. The primary outcome measure was the rate of participation in screening colonoscopy. Compliance with the assigned bowel preparation, bowel preparation quality, and lesion detection rates were also evaluated.

Results A total of 13 621 individuals were randomized and 13 497 were analyzed (6752 in the low-volume group and 6745 in the standard-volume group). The participation rate (16.6 % vs. 15.5 %; P = 0.08) and compliance rate (93.3 % vs. 94.1 %; P = 0.39) did not differ significantly between the groups. In the low-volume group, fewer participants had adequate bowel preparation compared with the standard-volume group (whole colon 79.0 % vs. 86.4 %, P < 0.001; proximal colon 80.1 % vs. 87.3 %, P < 0.001). Detection rates of advanced adenoma (AADR) and advanced serrated polyps (ASPDR) were lower in the low-volume group than in the standard-volume group (AADR in the proximal colon 2.6 % vs. 4.3 %, P = 0.02; ASPDR in the whole colon 2.0 % vs. 3.3 %, P = 0.04; ASPDR in the proximal colon 1.0 % vs. 1.9 %, P = 0.048).

Conclusion When compared with a standard-volume bowel preparation with polyethylene glycol, low-volume bowel preparation with sodium picosulfate/magnesium citrate did not improve participation rate or lesion detection rates, and negatively affected bowel preparation quality.
Validation of whole-body radiographs for examining uterine
disorders in sexually intact female rabbits
Authors: Lübke V. Christine , Fehr Michael , Köstlinger Saskia
Published: February 2019

Objective The present study evaluated whole-body radiographs of female
rabbits regarding uterine disorders.

Material and methods Based on radiographs of 143 rabbits, visibility,
size, shape and density of the uterus, nutritional status of the animal and
possible metastasis in other organs were examined. A suspected diagnosis was
deduced. The radiological findings were compared with the results of the
histopathological examination.

Results Especially the nutritional status was important regarding the
visibility of the genital tract. In 99 of the 130 visible uteri (76.2 %), a
pathological alteration was detected. Thereof, endometrial hyperplasia was most
frequently seen (63.6 %), followed by neoplasia (altogether 42.4 %, 39.4 % of
these with adenocarcinoma), endometritis (35.4 %) and other diseases (18.2 %).
Forty-six rabbits showed only one disease, 42 rabbits had two, 10 rabbits three
and one rabbit four different diseases. Among 13 of the 143 uteri that were not
visible in the radiograph four were altered pathologically. In 31 of the 130
rabbits with a visible uterine region (21.7 %) the uterus was unaltered.
Visualising the uterus proved impossible in two of four skinny rabbits (2.8 %),
whereas in all 39 obese rabbits the uterus was visible. Only in one of the four
skinny rabbits was the uterus without pathological findings and six of the 39
obese rabbits showed no pathological alteration, visibility notwithstanding.
Calcification indicated a tumourous occurrence in 23 of 53 cases. Except for one
rabbit, the mineralised neoplasia was an adenocarcinoma (n = 22). Five animals
with calcification in the uterine region showed no abnormalities. Of these, the
calcification of four animals was no longer existent in the radiograph after
ovariohysterectomy. Neoplastic changes in the uterus did not always show
calcification. In 20 of the 44 patients with uterine neoplasia no calcification
was seen. Changes in uterine size occurred in 118 of the 143 rabbits (82.5 %)
and alteration of the uterine shape in 109 of the 143 rabbits (67.1 %).

Conclusion and clinical relevance Thus, the above presented parameters –
especially size, shape and mineralisation – are very important regarding uterine
diseases.
Bewertung der Pansenfüllung von Milchkühen zur Beurteilung
der individuellen Futteraufnahme in der Bestandsbetreuung
Authors: Götze Katharina , Crivellaro Patricia , Pieper Laura , Engelhard Thomas , Staufenbiel Rudolf
Published: February 2019

Ziel Postpartale Krankheitskomplexe der Milchkuh stehen häufig in
Beziehung mit einer ungenügenden Futteraufnahme (FA) um den Kalbezeitpunkt. Ziel
dieser Studie war, die Zusammenhänge zwischen dem Pansenfüllungs(PF)-Score und
der tierindividuellen FA zu untersuchen. Weiterhin sollte geprüft werden, ob der
PF-Score in der Praxis als Maßstab zur Abschätzung der tierindividuellen FA (in
kg Trockenmasse [TM] bzw. Frischmasse [FM] pro Kuh) genutzt werden kann.

Material und Methoden Die PF wurde bei pluriparen Kühen (n = 109) nach dem
durch halbe Noten modifizierten Schema von Zaaijer und Noordhuizen (2003)
täglich zwischen Tag 24 (± 4) ante partum (a. p.) und Tag 9 post partum (p. p.)
sowie an den Tagen 28 (± 2) p. p. und 60 (± 2) p. p. beurteilt. Neben einer
Aufzeichnung der tierindividuellen FA erfolgte deren Messung im
4-Stunden-Rhythmus über 24 Stunden (24-Stunden-Tagesprofile) bei 21 Kühen a. p.
und 10 Kühen p. p.

Ergebnisse Zwischen dem PF-Score und der FA bestand ante und post partum
eine signifikante Beziehung, wobei der Laktationszeitpunkt einen großen Einfluss
auf diesen Zusammenhang hatte. Unmittelbar post partum veränderte sich der
PF-Score bereits bei 3,5 kg zusätzlicher TM-Aufnahme mit einer halben Note.
Dagegen reagierte er ante partum erst, wenn die FA um 18 kg TM herabgesetzt
war.

Schlussfolgerung In der 1. Woche p. p. war der PF-Score ein sensibler
Indikator für die FA. Aufgrund seiner trägen Reaktion ante partum eignete er
sich in diesem Zeitraum nur dazu, Risikotiere zu detektieren, deren FA über
mehrere Tage deutlich reduziert ist.

Klinische Relevanz Die größte Aussagekraft besitzt die Beurteilung der PF
1 Woche p. p. zur Einschätzung des individuellen Anstiegs der FA nach dem
Kalben. Es wird empfohlen, in den ersten 7–9 Tagen p. p. den PF-Score täglich zu
erheben und individuell auszuwerten, um Risikotiere mit verminderter FA zu
detektieren. Ante partum können Kühe, deren FA stark vermindert ist, ebenfalls
detektiert und frühzeitig behandelt werden, um postpartalen Störungen
vorzubeugen. In der Laktation (überprüft an Tag 28 und 60 p. p.) scheint der
PF-Score in Bezug auf die tierindividuelle FA nur eine geringe Aussagekraft zu
besitzen.
Analysis of GDF15 and IGFBP7 in Hyperemesis Gravidarum Support Causality
Authors: Fejzo Marlena , Fasching Peter , Schneider Michael , Schwitulla Judith , Beckmann Matthias , Schwenke Eva , MacGibbon Kimber , Mullin Patrick
Published: February 2019

Objective Hyperemesis gravidarum, severe nausea and vomiting in pregnancy, occurs in up to 2% of pregnancies and leads to significant weight loss, dehydration, electrolyte imbalance, and ketonuria. It is associated with both maternal and fetal morbidity. Familial aggregation studies and twin studies suggest a genetic component. In a recent GWAS, we showed that placentation, appetite, and cachexia genes GDF15 and IGFBP7 are linked to hyperemesis gravidarum (HG). The purpose of this study is to determine whether GDF15 and IGFBP7 are upregulated in HG patients.

Methods We compared serum levels of GDF15 and IGFBP7 at 12 and 24 weeksʼ gestation in women hospitalized for HG, and two control groups, women with nausea and vomiting of pregnancy (NVP), and women with no NVP.

Results We show GDF15 and IGFBP7 serum levels are significantly increased in women with HG at 12 weeksʼ gestation. Serum levels of hCG are not significantly different between cases and controls. At 24 weeks gestation, when symptoms have largely resolved, there is no difference in GDF15 and IGFBP7 serum levels between cases and controls.

Conclusion This study supports GDF15 and IGFBP7 in the pathogenesis of HG and may be useful for prediction and diagnosis. The GDF15-GFRAL brainstem-activated pathway was recently identified and therapies to treat conditions of abnormal appetite are under intense investigation. Based on our findings, HG should be included.
Recent Developments in Palladium-Catalysed Non-Directed C–H Bond Activation in Arenes
Authors: Jørgensen Kåre , Fernández-Ibáñez M. , Kancherla Sindhu
Published: February 2019

Over the past decades, organic chemists have focussed on developing new approaches to directed C–H functionalisations, where the site selectivity is steered by the presence of a directing group (DG). Nonetheless, in recent years, more and more non-directed strategies are being developed to circumvent the requisite directing group, making C–H functionalisations more generic. This short review focuses on the latest developments in palladium-catalysed non-directed C–H functionalisations of aromatic compounds.

1 Introduction

2 C–C Bond Formation

2.1 C–H Arylation

2.2 C–H Alkylation

2.3 C–H Alkenylation

2.4 C–H Carbonylation

3 C–Heteroatom Bond Formation

3.1 C–O Bond Formation

3.2 C–N Bond Formation

3.3 C–S Bond Formation

4 Conclusion
Combining Defects in a Single Nanographene: A Fully Helical Saddle Ribbon
Authors: Cruz Carlos , Castro-Fernández Silvia , Maçôas Ermelinda , Millán Alba , Campaña Araceli
Published: February 2019

The controlled preparation of well-defined distorted nanographenes by a bottom-up approach based on organic synthesis permits the direct establishment of unprecedented structure–property relationships in carbon nanostructures. The simultaneous incorporation of various defects in nanographenes affords highly curved structures with novel or enhanced photophysical properties. In this sense, we recently reported a fully helical and saddle-shaped nanographene ribbon containing the first undecabenzo[7]helicene unit. Both its linear and nonlinear optical properties are enhanced in comparison with those of other partially π-extended [7]helicenes. Moreover, the new superhelicene exhibits the highest emission dissymmetry factor (g
lum) reported to date for a homochiral nanographene. The combination of both nonlinear and chiroptical properties in nanographenes opens up new possible future applications for those distorted nanostructures.

1 Introduction

2 Synthesis of Embedded Seven-Membered Rings

3 Combination of Defects: Seven-Membered Rings and π-Extended Helicenes

4 Conclusions and Outlook
Asymmetric Allylic Amination of Morita–Baylis–Hillman Adducts with Simple Aromatic Amines by Nucleophilic Amine Catalysis
Authors: Chen Xin , Zhao Shuai , Chen Zhi-Li , Rui Xue , Gao Ming-Mei
Published: February 2019

Asymmetric allylic amination of Morita–Baylis–Hillman (MBH) adducts with simple aromatic amines is successfully realized by nucleophilic amine catalysis. A range of substituted α-methylene-β-arylamino esters is accessed in moderate to high yields (up to 88%) and with excellent enantioselectivities (up to 97% ee). Inorganic fluorides are found to be able to improve the enantioselectivity of the allylic amination reaction. A pyrrole-2-carboxylate and a cyclic imide are also compatible with this catalytic system. A chiral 2,3-dihydroquinolin-4-one derivative is easily obtained from the allylic amination product.
Two Clinical Experiences with a New Sarcode: Potentised Mitral Valve in LM Potencies
Authors: Kara Shamini , Wadhwani Gyandas
Published: February 2019

Sarcodes are an important part of homeopathic materia medica, but their use is ambiguous. Mitral valve is yet another addition to the list but lacking in guidelines for therapeutic application based on homoeopathic drug proving data. Two clinical cases are outlined that empirically received potentised mitral valve in ascending LM potencies and experienced an improved quality of life that was corroborated with outcome in relation to impact of daily living (ORIDL). Potentised mitral valve may be a valuable addition to our materia medica after it has been proved according to homoeopathic guidelines.
Endoscopic Resection of a Cerebellopontine Angle Meningioma via a Retrosigmoid Approach
Authors: Hitti Frederick Luke , Lee John Y.K.
Published: February 2019

A variety of lesions may arise within the cerebellopontine angle (CPA). Schwannomas and meningiomas are most commonly found in this location. Imaging characteristics of meningiomas include hyperdensity on head computed tomography (CT) and avid contrast enhancement on T1-weighted postcontrast magnetic resonance imaging (MRI). Here, we present the case of a 49-year-old woman with enlarging right CPA meningioma. The patient reported mild hearing loss on the right but her neurological exam was otherwise benign. Since the lesion was enlarging and symptomatic, the patient was offered resection of the mass for diagnosis and treatment via an endoscopic retrosigmoid approach. We provide a video that illustrates the steps taken to resect this mass endoscopically. After cerebrospinal fluid (CSF) was drained to achieve brain relaxation, the tumor was visualized. The tumor had a rich vascular supply and had the appearance of a typical meningioma. The bipolar was used to cauterize the tumor's vascular supply. The tumor capsule was then opened with the microscissors. The round knife, suction, and ultrasonic tissue debrider were used to debulk the tumor. After internal debulking of the tumor, the capsule was dissected off the cerebellum and mobilized. A combination of blunt and sharp dissection was done to free the tumor capsule from the adjacent structures. Inferiorly, the lower cranial nerves were visualized. Tissue pathology confirmed a diagnosis of grade I meningioma. A gross total resection was achieved and the patient remained neurologically stable, postoperatively. Furthermore, T1-weighted postcontrast brain MRI, 1 year after surgery, showed no residual.

The link to the video can be found at: https://youtu.be/X9c_inLp-So.
Idiopathic Trigeminal Neuralgia: A Case Report
Authors: Jain Shruti , Lamba Chetna
Published: February 2019

Trigeminal neuralgia (TN) is the most frequent type of neuropathic facial pain affecting one or more branches of trigeminal nerve. Here, a 51-year-old woman diagnosed with idiopathic trigeminal neuralgia (ITN) presented with complaints of pain over right side of the face with redness of the eyes and excessive lachrymation since 5 years with weekly acute episodes of shooting pain. Chelidonium was chiefly prescribed followed by few doses of Spigelia as per indications which provided adequate pain relief. The complaints flared up following stressful circumstances for which Pulsatilla was prescribed after detailed case taking. The frequency, duration and intensity of pain reduced after homoeopathic treatment. The need for conventional medicine was also reduced. This suggests positive role of individualised homoeopathy in the treatment of ITN. Further studies should be undertaken to evaluate the role of homoeopathy in ITN.
Exponential stability for the compressible micropolar fluid with cylinder symmetry in R3
Authors: Huang Lan , Drazic Ivan
Published: February 2019

This paper is concerned with three-dimensional compressible viscous and heat-conducting micropolar fluid in the domain to the subset of R3 bounded with two coaxial cylinders that present the solid thermoinsulated walls, being in a perfect and polytropic thermodynamical sense. We prove that cylindrically symmetric solutions decay to a constant exponentially as time goes to infinity based on the assumptions that the initial total energy is sufficiently small and initial data are sufficiently smooth cylindrically symmetric functions.
Exact eigenvalues and eigenfunctions for a one-dimensional Gel’fand problem
Authors: Miyamoto Yasuhito , Wakasa Tohru
Published: February 2019

It is known that every positive solution of a one-dimensional Gel’fand problem can be written explicitly. In this paper, we give exact expressions of all the eigenvalues and eigenfunctions of the linearized eigenvalue problem at each solution. We study asymptotic behaviors of eigenvalues and eigenfunctions as the L∞-norm of the solution goes to infinity. We also study the problem u″ + λe−u = 0 and the associated linearized problem.
High performance and low-cost graphene vacuum pressure sensor based on one-step laser scribing
Authors: Jin Fu-Hua , Pang Yu , Cai Wen-Long , Jian Jin-Ming , Ren Lin-Lin , Fan Yan-Yan , Li Ming-Rui , Zhao Wei-Sheng , Yang Yi , Yang Si-Fan , Ren Tian-Ling
Published: February 2019

Vacuum pressure sensors play a significant role in industry and scientific research. However, there are still many challenges for further application of vacuum pressure sensors due to their complex fabrication and high cost. In this work, we have fabricated a graphene vacuum pressure sensor by one-step laser scribing within 25 min. The resistance of the sensor decreases with declining vacuum pressure. Four linear segments are obtained in the relationship between the resistance response and the vacuum pressure ranging from 7.5 × 10−4 Torr to 2.35 Torr at room temperature. Besides, the graphene sensor exhibits a high sensitivity of 1.2 × 10−2 Torr−1 and a rapid response time of 9 s, which are superior to previously reported sensors. The sensing mechanism of the graphene vacuum pressure sensor is investigated. Under the influence of van der Waals interactions between the stacked graphene multilayers, the void space among the neighboring graphene layers reduces with decreasing vacuum pressure, resulting in a decrease of the sheet resistance. The designed graphene vacuum pressure sensor with the distinguished features of high performance, small size, low cost, and simple fabrication shows great feasibility and tremendous potential for vacuum measurement applications.
Impedance spectroscopy of Al/AlN/n-Si metal-insulator-semiconductor (MIS) structures
Authors: Schmidt Rainer , Mayrhofer Patrick , Schmid Ulrich , Bittner Achim
Published: February 2019

In this work, a comprehensive characterization of metal-insulator-semiconductor structures by impedance spectroscopy is demonstrated for the case of electrically insulating, highly c-axis oriented, 600 nm sputter-deposited AlN films on n-Si substrates with Al top electrodes. Direct visual analysis and equivalent circuit fitting of the dielectric data were performed. For the latter procedure, the circuit model consisted of three series resistor-capacitor connection elements for the three dielectric contributions detected. The three contributions were identified as the AlN film, n-Si substrate, and an interface barrier effect. Several essential device parameters were determined separately, by visual or equivalent circuit fitting analysis, such as the dielectric permittivity of the AlN layer, the temperature dependence of the AlN permittivity, and the resistances of the AlN layer, the n-Si substrate, and the interface contribution. Furthermore, DC bias dependent impedance measurements allowed the identification of a Schottky-type interface barrier.
Ultrafast dynamics of magnetic vortices and pulse collapse in a laser-under dense plasma interaction
Authors: Li Guangyu , Li Song , Ain Quratul , Gao Kai , Mirzaie Mohammad , Hafz Nasr A. M.
Published: February 2019

The energy of an intense ultrashort laser pulse interacting with high density (still under dense) plasma is typically transformed into electron heating and in excitation of nonlinear coherent structures such as magnetic vortices, solitons, or post-solitons. Using 33 TW 30 fs laser pulses and a high-density nitrogen gas jet, we experimentally investigated magnetic vortices in the laser pulse collapse region where electrons are efficiently accelerated and heated. Those vortices, which are associated with rapidly decaying magnetic fields, are found to be immobile and persist for several picoseconds. A collisionless plasma was formed due to the quasi-static field ionization of the gas associated with the hot and fast electron currents. The evolution dynamics of such nonlinear plasma phenomena have been monitored by using a 30-fs probe laser beam through employing the polarimetric and shadowgraphic techniques. Our experimental results are also supported by particle-in-cell simulations.
Imaging collective behavior in an rf-SQUID metamaterial tuned by DC and RF magnetic fields
Authors: Zhuravel Alexander P. , Bae Seokjin , Lukashenko Alexander V. , Averkin Alexander S. , Ustinov Alexey V. , Anlage Steven M.
Published: February 2019

We examine the collective behavior of two-dimensional nonlinear superconducting metamaterials using a non-contact spatially resolved imaging technique. The metamaterial is made up of sub-wavelength nonlinear microwave oscillators in a strongly coupled 27 × 27 planar array of radio-frequency Superconducting QUantum Interference Devices (rf-SQUIDs). By using low-temperature laser scanning microscopy, we image microwave currents in the driven SQUIDs while in non-radiating dark modes and identify the clustering and uniformity of like-oscillating meta-atoms. We follow the rearrangement of coherent patterns due to meta-atom resonant frequency tuning as a function of external dc and rf magnetic flux bias. We find that the rf current distribution across the SQUID array at zero dc flux and small rf flux reveals a low degree of coherence. By contrast, the spatial coherence improves dramatically upon increasing the rf flux amplitude, in agreement with simulation.
Mathematical model of gender bias and homophily in professional hierarchies
Authors: Clifton Sara M. , Hill Kaitlin , Karamchandani Avinash J. , Autry Eric A. , McMahon Patrick , Sun Grace
Published: February 2019

Women have become better represented in business, academia, and government over time, yet a dearth of women at the highest levels of leadership remains. Sociologists have attributed the leaky progression of women through professional hierarchies to various cultural and psychological factors, such as self-segregation and bias. Here, we present a minimal mathematical model that reveals the relative role that bias and homophily (self-seeking) may play in the ascension of women through professional hierarchies. Unlike previous models, our novel model predicts that gender parity is not inevitable, and deliberate intervention may be required to achieve gender balance in several fields. To validate the model, we analyze a new database of gender fractionation over time for 16 professional hierarchies. We quantify the degree of homophily and bias in each professional hierarchy, and we propose specific interventions to achieve gender parity more quickly.
Simulation research on magnetic pole erosion of Hall thrusters
Authors: Ding Yongjie , Wang Lei , Fan Haotian , Li Hong , Xu Weifeng , Wei Liqiu , Li Peng , Yu Daren
Published: February 2019

It is shown from the experimental results of existing Hall thrusters that erosion phenomena occur in the magnetic poles when the maximum magnetic field is located in the plume region. The developed Particle-in-Cell model is used in this paper for simulation research on magnetic pole erosion of Hall thrusters. The simulation results show that when the maximum magnetic field is located in the plume region, there is a large potential drop between the channel outlet and the magnetic pole. Therefore, low-energy ions close to the outlet plane are accelerated to bombard the magnetic pole surface, which is an important reason for the magnetic pole erosion. Moreover, the ion flux and energy bombarded on the magnetic pole under two conditions (magnetic pole grounding and floating) are calculated and compared. It is shown from the simulation results that grounding the magnetic pole can reduce the potential drop between the channel outlet and magnetic pole, thereby reducing the ion energy and flux bombarded on the magnetic pole and effectively alleviating the erosion of the magnetic pole.
The dielectric constant: Reconciling simulation and experiment
Authors: Jorge Miguel , Lue Leo
Published: February 2019

In this paper, we present a simple correction scheme to improve predictions of dielectric constants by classical non-polarisable models. This scheme takes into account electronic polarisation effects, through the experimental refractive index of the liquid, and a possible mismatch between the potential energy surface and the dipole moment surface. We have described the latter effect by an empirical scaling factor on the point charges, the value of which was determined by fitting the dielectric constant of methanol. Application of the same scaling factor to existing benchmark datasets, comprising four different models and a wide range of compounds, led to remarkable improvements in the quality of the predictions. In particular, the observed systematic underestimation of the dielectric constant was eliminated by accounting for the two missing terms in standard models. We propose that this correction term be included in future development and validation efforts of classical non-polarisable models.
Effects of core space and excitation levels on ground-state correlation and photoionization dynamics of Be and Ne
Authors: Omiste Juan J. , Madsen Lars Bojer
Published: February 2019

We explore the effects of correlation on the ground-state energies and on photoionization dynamics in atomic Be and Ne. We apply the time-dependent restricted-active-space self-consistent-field method for several excitation schemes and active orbital spaces with and without a dynamic core to address the effects systematically at different levels of approximation. For the ground-state many-electron wave functions, we compare the correlation energies with entropic measures of entanglement. A larger magnitude of the correlation energy does not always correspond to a larger value of the considered entanglement measures. To evaluate the impact of correlation in a process involving continua, we consider photoionization by attosecond pulses. The photoelectron spectra may be significantly affected by including a dynamical core.
Relativistic coupled-cluster investigation of parity (P) and time-reversal (T ) symmetry violations in HgF
Authors: Talukdar Kaushik , Nayak Malaya K. , Vaval Nayana , Pal Sourav
Published: February 2019

We employ the Z-vector method in the four-component relativistic coupled-cluster framework to calculate the parity (P) and time-reversal (T ) symmetry violating scalar-pseudoscalar nucleus-electron interaction constant (Ws), the effective electric field (Eeff) experienced by the unpaired electron, and the nuclear magnetic quadrupole moment-electron interaction constant (WM) in the open-shell ground electronic state of HgF. The molecular frame dipole moment and the magnetic hyperfine structure (HFS) constant of the molecule are also calculated at the same level of theory. The outcome of our study is that HgF has a high value of Eeff (115.9 GV/cm), Ws (266.4 kHz), and WM (3.59 × 1033 Hz/e cm2), which shows that it can be a possible candidate for the search of new physics beyond the standard model. Our results are in good agreement with the available literature values. Furthermore, we investigate the effect of the basis set and the virtual energy functions on the computed properties. The role of the high-energy virtual spinors is found to be significant in the calculation of the HFS constant and the P,T-odd interaction coefficients.
Is it possible to enlarge the trapping range of optical tweezers via a single beam?
Authors: Li X. Z. , Ma H. X. , Zhang H. , Tang M. M. , Li H. H. , Tang J. , Wang Y. S.
Published: February 2019

For optical tweezers, a tiny focal spot of the trapping beam is necessary for providing sufficient intensity-gradient force. This condition results in a limited small trapping range to guarantee stable trapping of the particle. Exploiting structured light, i.e., an optical vortex beam, the trapping range can be enlarged by adjusting its doughnut ring diameter. However, the trapped particle scarcely remains static due to the optical spanner action of the orbital angular momentum of the vortex beam. To enlarge the trapping range and simultaneously ensure stable trapping, we propose a beam, referred to as a mirror-symmetric optical vortex beam (MOV). Essentially, MOV is constructed by using two opposite optical spanners and a pair of static optical tweezers. The optical spanners attract the particle to the site of the static optical tweezers, which realizes long-range optical trapping. Through detailed force-field analysis, it is found that MOV could perform these setting functions. In experiments, yeast cells are manipulated in a long range of ∼25 μm, which is 3 times longer than that of the Gaussian beam. Further, the trapping range is easily adjusted by changing a parameter as desired. This technique provides versatile optical tweezers, which will facilitate potential applications for particle manipulation.
The correlation factor model for the exchange-correlation energy and its application to transition metal compounds
Authors: Wang Rodrigo , Zhou Yongxi , Ernzerhof Matthias
Published: February 2019

In the recently developed correlation factor (CF) model [Precechtelova et al., J. Chem. Phys. 143, 144102 (2015)], the exchange-correlation (XC) hole is approximated. Since various constraints satisfied by the XC-hole are known, approximations to it can be designed which largely avoid empirical adjustments. In the CF approach, the XC-hole is written as a product of an exchange hole times a CF. An important constraint satisfied by the CF model is that it correctly reproduces the exact exchange energy in the high density limit. This is achieved by employing the exact exchange-energy per particle (ϵXr) as an input variable, i.e., the CF model builds on exact exchange. Variations of the initial CF model are proposed which ensure that the exact answer is obtained in the homogeneous limit. Furthermore, we apply a correction to the depth of the XC-hole that is designed to capture strong correlation. EC functionals that build on exact exchange, such as hybrids, often fail for systems that exhibit sizeable electron correlation. Despite this fact and despite the reduction of empiricism to a single parameter within CF, accurate atomization energies are obtained for strongly-correlated transition metal compounds. The CF model significantly improves upon widely used functionals such as Perdew-Burke-Ernzerhof (PBE), PBE hybrid, and Tao-Perdew-Staroverov-Scuseria (TPSS).
Numerical study of dispersion of nanoparticles in magnetohydrodynamic liquid with Hall and ion slip currents
Authors: Qureshi Imran Haider , Nawaz M. , Shahzad A.
Published: February 2019

Heat transfer in partially ionized Erying-Powell liquid containing four types of nano-particles is discussed in this manuscript. Mathematical models for the mixture Erying-Powell plasma and nano-particles are developed and are solved by using finite element method (FEM). Numerical computations are carried out under tolerance 10-5. Physical parameters have significant effects on both thermal boundary layer thicknesses and momentum boundary layer thicknesses. Shear stresses at the surface can be minimized by the Hall and ion slip currents whereas the shear stresses at the sheet for Erying-Powell fluid are high as comparing to the Newtonian fluid. The rate of transfer of heat is significantly influenced by Hall and ion slip parameters. Highest rate of transfer of heat is observed for the case of TiO2 nano-particles. Therefore, it is recommended to disperse TiO2 nano-particles in Erying-Powell fluid for enhancement of heat transfer in Erying-Powell plasma.
Surface evolution of native silicon oxide layer and its effects on the growth of self-assisted VLS GaAs nanowires
Authors: Vorathamrong Samatcha , Panyakeow Somsak , Ratanathammaphan Somchai , Praserthdam Piyasan
Published: February 2019

This research focuses on the impact of native SiO2 layer evolution, occurring on the surfaces of Si(111) substrates on the morphological and structural properties of self-assisted GaAs nanowires. GaAs nanowires growth were grown on Si(111) substrates, already covered with native SiO2 developing in different states with identical growth parameters including growth temperature, growth time, and Ga and As flux, using self-assisted VLS process by MBE technique. Results from nanowire samples and substrates were compared to understand the correlation between the changes in appearance of native SiO2 layer and the changes in the growth pattern of the nanowires.
Action-spectroscopy studies of positively charge-tagged azobenzene in solution and in the gas-phase
Authors: Gruber Elisabeth , Strauss Marcel A. , Wegner Hermann A. , Andersen Lars H.
Published: February 2019

The absorption of a positively charge-tagged azobenzene molecule is studied in the gas-phase by measuring photoinduced fragmentation of ions as a function of time. This technique provides information on prompt as well as delayed fragmentation, and a single dissociation channel after one-photon absorption is identified. The spectra in solution, as well as in the gas-phase, show a weak S0 → S1, a strong S0 → S2, and a broad absorption band in the UV regime. The bands are assigned through time dependent density functional theory calculations. The ratio of the various absorption bands depends on the trans to cis isomerization fraction and may be tuned by light irradiation. Gas-phase absorption spectra are presented and discussed in terms of trans and cis isomers.
A new model for the bouncing regime boundary in binary droplet collisions
Authors: Al-Dirawi Karrar H. , Bayly Andrew E.
Published: February 2019

This work experimentally investigates binary collisions of identical droplets over a range of liquid viscosities, using 2%, 4%, and 8% of hydroxypropyl methylcellulose solutions in water. The collisions were captured by using a high-speed camera, and regime maps of collision outcomes were derived. The performance of existing models of the boundary of the bouncing regime was assessed and found to give poor predictions. This was attributed to assumptions and errors in the treatment of kinetic energy and the droplet shape factors used in these models. A new model was derived which addresses these issues: the definition of the kinetic energy that contributes to deformation was corrected; a new shape factor that accurately reflects the geometry of the droplet at maximum deformation was proposed, and, importantly, an empirical approach was implemented to account for the effect of the impact parameter on this shape factor. Moreover, the model includes an estimate of the viscous dissipation, which is calculated directly from the experimentally observed difference between the impact and the rebound kinetic energies and measurements of the post-collision droplet oscillations. The proposed model shows a striking improvement versus the existing models, reducing the mean absolute error by an order of magnitude.
A model of carrier density and drain current for monolayer graphene field-effect transistors
Authors: Zhuang Feng , Deng Wanling , Ma Xiaoyu , Huang Junkai
Published: February 2019

A model of carrier density and drain current for monolayer graphene field-effect transistors (GFET) is proposed in this paper. In general, the carrier density is the numerical integration of the density of states (DOS) and Fermi-Dirac distribution. To avoid numerical solution, a physical-based and analytical calculation for carrier density and quantum capacitance is presented. Due to the intrinsic physical mechanism, the interface trap density is taken into account in the drain current model of GFET. Through the comparisons between model results and numerical iterations or experimental data, the validity of the proposed models is supported. The clear physical conception and simplicity of algorithm make our scheme suitable for compact modelling.
Homogeneous shrinking/amplifying device and its layered realization
Authors: Yang Chengfu , Huang Ming , Li Tinghua , Yang Jingjing , Mao Fuchun , Xue Yuyang
Published: February 2019

Arbitrary regular/irregular shaped electromagnetic shrinking device and amplifying device with homogeneous, non-negative, anisotropic and genetic constitutive parameters are proposed and designed based on linear transformation optics, which provides the flexibility for device designing, and closer to the practical implementation. Furthermore, layered structure based on effective medium theory is utilized to remove the anisotropic property of the proposed device. Simulation results show that when with sufficient layers, both the layered shrinking device and amplifying device behave nearly as perfect as the ideal one. A dielectric or magnetic object placed inside the proposed device will be visually transformed into another object with a bigger/smaller size and different constitutive parameters are figured out clearly, making the proposed device have potential applications in military camouflage or other field of electromagnetic engineering system. The shrinking/amplifying scale is tailored by the ratio of b/c (b and c are the quasi-radius of the arbitrarily shaped polygon). Composing of alternatively isotropic layers with positive material parameters would dramatically reduce the fabrication difficulty and move the device a step further towards the practical application.
Non-uniform Mg distribution in GaN epilayers grown on mesa structures for applications in GaN power electronics
Authors: Liu Hanxiao , Fu Houqiang , Fu Kai , Alugubelli Shanthan R. , Su Po-Yi , Zhao Yuji , Ponce Fernando A.
Published: February 2019

A strong variation in the luminescence characteristics in Mg-doped GaN grown on mesa structures has been observed, with the sidewall luminescence being different from that of the flat regions. A comparison with the luminescence characteristics of Mg-doped GaN epilayers with different Mg concentrations indicates that the sidewall has a significantly lower Mg content. This observed non-uniform Mg distribution is attributed to the dependence of Mg incorporation efficiency on the crystal orientation of the growth surface, which should impact the electrical performance of power devices.
Quantum dots with split enhancement gate tunnel barrier control
Authors: Rochette S. , Rudolph M. , Roy A.-M. , Curry M. J. , Eyck G. A. Ten , Manginell R. P. , Wendt J. R. , Pluym T. , Carr S. M. , Ward D. R. , Lilly M. P. , Carroll M. S. , Pioro-Ladrière M.
Published: February 2019

We introduce a silicon metal-oxide-semiconductor quantum dot architecture based on a single polysilicon gate stack. The elementary structure consists of two enhancement gates separated spatially by a gap, one gate forming a reservoir and the other a quantum dot. We demonstrate that, in three devices based on two different versions of this elementary structure, a wide range of tunnel rates is attainable while maintaining single-electron occupation. A characteristic change in the slope of the charge transitions as a function of the reservoir gate voltage, attributed to screening from charges in the reservoir, is observed in all devices and is expected to play a role in the sizable tuning orthogonality of the split enhancement gate structure. The all-silicon process is expected to minimize strain gradients from electrode thermal mismatch, while the single gate layer should avoid issues related to overlayers (e.g., additional dielectric charge noise) and help improve the yield. Finally, reservoir gate control of the tunnel barrier has implications for initialization, manipulation, and readout schemes in multi-quantum dot architectures.
TiO2 Films Functionalized with ABDA for Enhanced Photoelectrochemical Performance
Authors: Chen Penggang , Zhang Lulu , Liu Bingwen , Chen Peng , Yan Pengfei
Published: February 2019

Efficient photogenerated charge separation is needed for potential solar energy conversion and storage. Herein, we present the preparation and characterization of an optically active anthracence-based molecule 4,4′-(anthracene-2,6-diylbis(azanediyl))bis(4-oxobutanoic acid) (ABDA), whose coupling with TiO2 has been proven useful in the pursuit of enhanced photoelectrochemical (PEC) performance. Ultraviolet-visible absorption spectroscopy and PEC measurements indicated that the ABDA/TiO2 composite has extended the light absorption of TiO2 to the visible region and efficiently increased the charge separation. The photocurrent of ABDA/TiO2 is 1.8 times higher than that of pristine TiO2. This study has provided a method for the development of functionalized TiO2 with enhanced PEC behaviour for energy conversion applications.
Phosphatidic acids mediate transport of Ca2+ and H+ through plant cell membranes
Authors: Medvedev Sergei , Voronina Olga , Tankelyun Olga , Bilova Tatiana , Suslov Dmitry , Bankin Mikhail , Mackievic Viera , Makavitskaya Maryia , Shishova Maria , Martinec Jan , Smolikova Galina , Sharova Elena , Demidchik Vadim
Published: February 2019

Phosphatidic acids (PAs) are a key intermediate in phospholipid biosynthesis, and a central element in numerous signalling pathways. Functions of PAs are related to their fundamental role in molecular interactions within cell membranes modifying membrane bending, budding, fission and fusion. Here we tested the hypothesis that PAs are capable of direct transport of ions across bio-membranes. We have demonstrated that PAs added to the maize plasma membrane vesicles induced ionophore-like transmembrane transport of Ca2+, H+ and Mg2+. PA-induced Ca2+ fluxes increased with an increasing PAs acyl chain unsaturation. For all the PAs analysed, the effect on Ca2+ permeability increased with increasing pH (pH 8.0>pH 7.2>pH 6.0). The PA-induced Ca2+, Mg2+ and H+ permeability was also more pronounced in the endomembrane vesicles as compared with the plasma membrane vesicles. Addition of PA to protoplasts from Arabidopsis thaliana (L.) Heynh. roots constitutively expressing aequorin triggered elevation of the cytosolic Ca2+ activity, indicating that the observed PA-dependent Ca2+ transport occurs in intact plants.
Amplification of abiotic stress tolerance potential in rice seedlings with a low dose of UV-B seed priming
Authors: Thomas Dhanya T. , Puthur Jos T.
Published: February 2019

UV-B radiation is a major abiotic stress factor that adversely affects the growth and productivity of crop plants including rice (Oryza sativa L.). However, on the other hand, lower doses of UV-B radiation applied to seeds can have a priming effect on plants emerging from it. In this study, seeds of O. sativa var. kanchana were primed with UV-B radiation (6 kJ m–2) and were further subjected to NaCl, polyethylene glycol 6000 (PEG) and UV-B stress. The effects of UV-B priming in imparting NaCl, PEG and UV-B stress tolerance to rice seedlings were analysed through various photosynthetic features and antioxidative mechanisms. PSI and PSII activity levels as well as chl a fluorescence were found to be significantly higher in the UV-B primed and unstressed seedlings. When stress (NaCl, PEG and high UV-B) was imposed, increased PSI and PSII activity levels, chl a fluorescence and metabolite accumulation (proline, total phenolics and sugar) as well as nonenzymatic (ascorbate and glutathione) and enzymatic (superoxide dismutase, catalase, ascorbate peroxidase) antioxidants were recorded in UV-B primed and NaCl-stressed plants followed by UV-B primed and UV-B–stressed plants, and primed and PEG-stressed, compared with unprimed and stressed conditions. The results indicate that UV-B priming in rice seedlings effectively enhances the NaCl stress tolerance potential in rice to a greater extent than UV-B and PEG stress tolerance potential. The cost-effectiveness of UV-B seed priming is predominantly clear from the differing tolerance responses of rice seedlings exposed to different stress conditions.
Successive crystal structure snapshots suggest the basis for MHC class I peptide loading and editing by tapasin
Authors: Hafstrand Ida , Sayitoglu Ece Canan , Apavaloaei Anca , Josey Benjamin John , Sun Renhua , Han Xiao , Pellegrino Sara , Ozkazanc Didem , Potens Renée , Janssen Linda , Nilvebrant Johan , Nygren Per-Åke , Sandalova Tatyana , Springer Sebastian , Georgoudaki Anna-Maria , Duru Adil Doganay , Achour Adnane
Published: February 2019

MHC-I epitope presentation to CD8
+
T cells is directly dependent on peptide loading and selection during antigen processing. However, the exact molecular bases underlying peptide selection and binding by MHC-I remain largely unknown. Within the peptide-loading complex, the peptide editor tapasin is key to the selection of MHC-I–bound peptides. Here, we have determined an ensemble of crystal structures of MHC-I in complex with the peptide exchange-associated dipeptide GL, as well as the tapasin-associated scoop loop, alone or in combination with candidate epitopes. These results combined with mutation analyses allow us to propose a molecular model underlying MHC-I peptide selection by tapasin. The N termini of bound peptides most probably bind first in the N-terminal and middle region of the MHC-I peptide binding cleft, upon which the peptide C termini are tested for their capacity to dislodge the tapasin scoop loop from the F pocket of the MHC-I cleft. Our results also indicate important differences in peptide selection between different MHC-I alleles.
Evolution of chloroplast retrograde signaling facilitates green plant adaptation to land
Authors: Zhao Chenchen , Wang Yuanyuan , Chan Kai Xun , Marchant D. Blaine , Franks Peter J. , Randall David , Tee Estee E. , Chen Guang , Ramesh Sunita , Phua Su Yin , Zhang Ben , Hills Adrian , Dai Fei , Xue Dawei , Gilliham Matthew , Tyerman Steve , Nevo Eviatar , Wu Feibo , Zhang Guoping , Wong Gane K.-S. , Leebens-Mack James H. , Melkonian Michael , Blatt Michael R. , Soltis Pamela S. , Soltis Douglas E. , Pogson Barry J. , Chen Zhong-Hua
Published: February 2019

Chloroplast retrograde signaling networks are vital for chloroplast biogenesis, operation, and signaling, including excess light and drought stress signaling. To date, retrograde signaling has been considered in the context of land plant adaptation, but not regarding the origin and evolution of signaling cascades linking chloroplast function to stomatal regulation. We show that key elements of the chloroplast retrograde signaling process, the nucleotide phosphatase (SAL1) and 3′-phosphoadenosine-5′-phosphate (PAP) metabolism, evolved in streptophyte algae—the algal ancestors of land plants. We discover an early evolution of SAL1-PAP chloroplast retrograde signaling in stomatal regulation based on conserved gene and protein structure, function, and enzyme activity and transit peptides of SAL1s in species including flowering plants, the fern
Ceratopteris richardii
, and the moss
Physcomitrella patens
. Moreover, we demonstrate that PAP regulates stomatal closure via secondary messengers and ion transport in guard cells of these diverse lineages. The origin of stomata facilitated gas exchange in the earliest land plants. Our findings suggest that the conquest of land by plants was enabled by rapid response to drought stress through the deployment of an ancestral SAL1-PAP signaling pathway, intersecting with the core abscisic acid signaling in stomatal guard cells.