bluuebunny/crossref_metadata_2025 huggingface dataset:
Microsurgical Resection of Tuberculum Sellae Meningioma through Left Cranio-orbital Approach
Authors: Pojskić Mirza , Arnautović Kenan
Published: January 2018

In this video clip, the authors present the resection of a tuberculum sellae meningioma with compression of the left optic nerve and a chiasm (Fig. 1) through a standard cranial orbital (CO) skull base approach.1
2
3 The key step in the tumor resection was microsurgical dissection of left and right A1 segments of the anterior cerebral artery and the anterior communicating artery and the separation of the tumor from these vascular structures. This was followed by careful separation of the meningioma from both optic nerves, the chiasm and the pituitary stalk. The final step was coagulation and resection of the tumor origin on the dura of the tuberculum sellae, devascularizing the tumor. Once this was achieved, the tumor was removed. Using this approach, an optimal surgical corridor to the sellar area was provided while minimizing the retraction of frontal and temporal lobes.

The link to the video can be found at: https://youtu.be/O59Fj2dNXB0.
Endoscopic Transsphenoidal Resection of Craniopharyngioma
Authors: Liew Kong , Narayanan Prepageran , Waran Vicknes
Published: January 2018

Objectives To demonstrate, step-by-step, the technique and efficacy of endoscopic transsphenoidal approach in resection of a suprasellar craniopharyngioma.

Design The video shows a step-by-step approach to the resection, covering the exposure, access, resection, and confirmation of resection and reconstruction.

Setting The surgery was performed in the University of Malaya Medical Centre, a tertiary referral center in the capital of Malaysia.

Participants Surgery was performed jointly by Professor Prepageran from the department of otorhinolaryngology and Professor Vicknes Waran from the division of neurosurgery. Both surgeons are from the University of Malaya. Video compilation, editing, and voice narration was done by Dr. Kong Yew Liew.

Main Outcome Measures Completeness of resection and avoidance of intra- and postoperative complications.

Results Based on intraoperative views and MRI findings, the tumor was completely resected with the patient suffering only transient diabetes insipidus.

Conclusion Central suprasellar tumors can be removed completely via an endoscopic transsphenoidal approach with minimal morbidity to the patient.

The link to the video can be found at: https://youtu.be/ZNIHfk12cYg.
Resection of an Optic Canal Meningioma through a Contralateral Subfrontal Approach with Endoscopic Assistance: A 2D Operative Video
Authors: Labidi Moujahed , Watanabe Kentaro , Bernat Anne-Laure , Hanakita Shunya , Froelich Sébastien
Published: January 2018

Objective To review the use of the contralateral subfrontal approach for the resection of an optic canal meningioma.

Design Operative video.

Results A meningioma, located in the inferomedial side of the optic canal (Fig. 1), was found to cause significant visual deterioration. The subfrontal route was preferred to expose the tumor without mobilization of the optic nerve. Drilling of the anterior limb of the chiasmatic sulcus (limbus sphenoidale) provided adequate exposure of the medial aspect of the optic canal. Gross total resection (Simpson II) of the tumor was accomplished, and endoscopic assistance allowed identification and coagulation of an infiltrated dura mater in the chiasmatic sulcus and tuberculum sellae.

Conclusion The subfrontal approach grants an optimal surgical trajectory to the contralateral chiasmatic sulcus and optic nerve. When the medial side of the optic canal is drilled, tumors extending into the optic canal can be safely resected, under direct visualization of the inferomedial side of the optic nerve. Breach into the sphenoid sinus can occur during drilling of the anterior limb of the chiasmatic sulcus. Endoscopic assistance can provide a better view on blind areas of the surgical field, including the depth of the optic canal (Fig. 2).

The link to the video can be found at: https://youtu.be/fS2udUCPH1g.
Infrasellar Endoscopic Endonasal Approach for a Pituitary Adenoma Extending into the Third Ventricle, with Anterior Displacement of the Pituitary Gland
Authors: Zenonos Georgios , Wang Eric , Fernandez-Miranda Juan
Published: January 2018

Objectives The current video presents the nuances of the infrasellar endoscopic endonasal approach for a pituitary adenoma extending into the third ventricle, with anterior displacement of the pituitary gland.

Design The video analyzes the presentation, preoperative workup and imaging, surgical steps and technical nuances of the surgery, the clinical outcome, and follow-up imaging.

Setting The patient was treated by a skull base team consisting of a neurosurgeon and an ENT surgeon at a teaching academic institution.

Participants The case refers to 73-year-old female patient who was found to have a sellar mass after failure of vision to improve with cataract surgery. She also reported a several-month history of progressive loss of vision along with daily retro-orbital headaches. The adenoma extended into the clivus as well as in the retrosellar and suprasellar regions, eroding into the floor of the third ventricle. The normal gland was displaced anteriorly.

Main Outcome Measures The main outcome measures consisted of reversal of patient symptoms (headaches and visual disturbance), recurrence-free survival based on imaging, as well as absence of any complications.

Results The patient's headaches and visual fields improved. There was no evidence of recurrence.

Conclusion The infrasellar endoscopic endonasal approach is safe and effective for pituitary adenomas extending into the third ventricle, with anterior displacement of the pituitary gland.

The link to the video can be found at: https://youtu.be/zp_06mEyRvY.
Approach to Infants Born Through Meconium Stained Amniotic Fluid: Evolution Based on Evidence?
Authors: Nangia Sushma , Chandrasekharan Praveen , Lakshminrusimha Satyan , Rawat Munmun
Published: January 2018

Meconium-stained amniotic fluid (MSAF) during delivery is a marker of fetal stress. Neonates born through MSAF often need resuscitation and are at risk of meconium aspiration syndrome (MAS), air leaks, hypoxic-ischemic encephalopathy, extracorporeal membrane oxygenation (ECMO), and death. The neonatal resuscitation approach to MSAF has evolved over the last three decades. Previously, nonvigorous neonates soon after delivery were suctioned under the vocal cords with direct visualization technique using a meconium aspirator. The recent neonatal resuscitation program (NRP) recommends against suctioning but favors resuscitation with positive pressure ventilation of nonvigorous neonates with MSAF. This recommendation is aimed to prevent delay in resuscitation and minimize hypoxia-ischemia often associated with MSAF. In this review, we discuss the pathophysiology, evolution and the evidence, randomized control trials, observational studies, and translational research to support these recommendations. The frequency of ECMO use for neonatal respiratory indication of MAS has declined over the years probably secondary to improvements in neonatal intensive care and reduction of postmaturity. Changes in resuscitation practices may have contributed to reduced incidence and severity of MAS. Larger randomized controlled studies are needed among nonvigorous infants with MSAF. However, ethical dilemmas and loss of equipoise pose a challenge to conduct such studies.
Volar Locking Plate Fixation of Distal Radius Fractures: Splint versus Immediate Mobilization
Authors: Duprat André , Diaz Juan , Vernet Paul , Gouzou Stéphanie , Facca Sybille , Igeta Yuka , Liverneaux Philippe
Published: January 2018

Background The goal of this study was to demonstrate that the use of a splint after performing an osteosynthesis of the distal radius with a volar locking plate is unnecessary. The main hypothesis was that postoperative flexion of the wrist was greater without a splint. Secondary hypothesis was that patients who were allowed immediate mobilization got better results in terms of pain, Quick Disabilities of the Arm, Shoulder and Hand (DASH), Patient-Rated Wrist Evaluation (PRWE), strength, extension, pronation, and supination.

Case Description Our series included 72 patients, aged 59 years in average of which 59 were female patients. All patients had been operated for a volar locking plate fixation of a distal radius fracture. The first 36 patients (group I) were immobilized by a splint at 30° of extension of the wrist for 2 weeks. The following 36 patients (group II) were not immobilized.

Results At 3 months, all the average variables were better in the group without splint (group I: flexion 74.83%, extension 83.13%, pronation 92.07%, supination 88.11%, pain 1.72/10, Quick DASH 21.78/100, PRWE 22.97/100, strength 62.96%; group II: flexion 85.50%, extension 83.4%, pronation 92.96%, supination 92.96%, pain 1.28/10, Quick DASH 19.57/100, PRWE 20.56/100, strength 66.34%). No complication was reported.

Conclusion Overall, our results demonstrate that wearing a splint after volar locking plate fixation of a distal radius fracture is unnecessary.
Endoscopic ultrasound-guided choledochoduodenostomy using partially-covered self-expandable metal stent in patients with malignant distal biliary obstruction and unsuccessful ERCP
Authors: Rai Praveer , Lokesh CR , Goel Amit , Aggarwal Rakesh
Published: January 2018

Background and study aims Endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) is an alternative to percutaneous transhepatic biliary drainage (PTBD) for patients with malignant distal biliary obstruction in whom ERCP has failed. We studied technical success, clinical success, stent patency rate and occurrence of adverse events in patients undergoing EUS-CDS with partially-covered self-expanding metal stent (PCSEMS).

Patients and methods Medical records of consecutive patients with unresectable malignant distal biliary obstruction requiring biliary drainage who underwent EUS-CDS because of failure of attempt at ERCP were reviewed. EUS-CDS was done using 6-cm, PCSEMS (Wallflex, Boston Scientific). Technical success, clinical success (more than 50 % reduction in total bilirubin at 2 weeks post-procedure), stent patency rate and adverse events (AEs) were assessed. Patients were followed up for 3 months post-procedure.

Results Between January 2015 and December 2016, 30 patients underwent EUS-CDS, including 20 (67 %) with failed biliary cannulation and 10 (33 %) with duodenal stenosis. Technical success was achieved in 28 patients, all of whom also had clinical success. Median total serum bilirubin decreased from 20 mg/dL to 5 mg/dL at 2 weeks post-procedure. Three patients (10 %) had adverse events (bile leak, hemobilia, stent block in one patient each; no stent migration); none of these adverse events was major and all were managed successfully. There were no procedure-related deaths. Five patients died of disease progression in the 3-month period post-procedure, and the 3-month dysfunction-free stent patency rate was 83 %.

Conclusion EUS-CDS with a PCSEMS has a high technical and clinical success. Adverse events were infrequent, minor and could be managed easily.
Endoscopic ultrasound guided needle-based confocal laser endomicroscopy in solid pancreatic masses – a prospective validation study
Authors: Karstensen John , Cârţână Tatiana , Constantinescu Codruţa , Dumitrașcu Silviu , Kovacevic Bojan , Klausen Pia , Hassan Hazem , Klausen Tobias , Bertani Helga , Bhutani Manoop , Săftoiu Adrian , Vilmann Peter
Published: January 2018

Background and study aims Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is a keystone in diagnosing and staging of pancreatic masses. Recently, a microfiber that can pass through a 19-gauge needle has been introduced for confocal laser endomicroscopy (nCLE). The aims of this study were to evaluate the diagnostic value and the reproducibility of nCLE criteria for solid malignant lesions.

Patients and methods This prospective dual-center study included patients with pancreatic masses suspicious of malignancy referred for EUS-FNA. Endomicroscopic imaging was performed under EUS-guidance until organ-specific structures were obtained. Afterwards, standard cytology was obtained and patients were followed for up to 12 months. All nCLE parameters included in former studies were correlated with the final diagnosis (dark lobular structures/normal acinar cells, dark cell aggregates > 40 µm, dilated irregular vessels with fluorescein leakage, fine white fibrous bands, small black cell movements, pseudoglandular structures). Finally, three CLE novices and three CLE experts assessed the unedited movies from all patients.

Results Twenty-eight patients were enrolled in the study. A final diagnosis was obtained in 24 patients (86 %). One patient (3 %) died before a diagnosis was obtained, while 3 were lost to follow-up (11 %). In 18/24 patients (74 %) the diagnosis was malignant. The mean sensitivity, specificity, and accuracy for the nCLE parameters ranged from 19 – 93 %, 0 – 56 %, 26 – 69 %, respectively. The inter-observer values ranged from κ = 0.20 – 0.41 for novices and κ = –0.02 – 0.38 for experts.

Conclusions The diagnostic value of nCLE in solid pancreatic masses is questionable and the inter-observer agreement for both novices and CLE experts appears limited.
Ameliorative Effects of Zataria Multiflora Hydro-Alcoholic extract on Gentamicin Induced Nephrotoxicity in Rats
Authors: Hajihashemi Saeed , Jafarian Tahereh , Ahmadi Mahboubeh , Rahbari Ali , Ghanbari Fatemeh
Published: January 2018

Background Nephrotoxicity is the major side effects of aminoglycoside antibiotics such as gentamicin. The aim of this study was to investigate the therapeutic effects of Z.multiflora (ZM) hydroalcoholic extract on gentamicin-induced nephrotoxicity.

Methods Twenty-eight male Wistar rats categorized into four groups: 1) the control group without injection, 2) the gentamicin treated group (100 mg/kg, i.p) 3) the gentamicin and Z. Multiflora treated group; Z. Multiflora extract(0.8 mg/ml in the drinking water) administered after gentamicin (100 mg/kg, i.p) 4) the normal saline and Z. Multiflora treated group; Z. Multiflora extract (0.8 mg/ml in the drinking water) administered after normal saline injection (2 ml/kg,i.p ).

Results Post-treatment with ZM extract caused a significant reduction in the levels of plasma creatinine and blood urea nitrogen (BUN), absolute and fractional excretion of sodium, malondialdehyed (MDA) level in comparison to gentamicin group. In addition, ZM extract significantly increased creatinine clearance, urine osmolarity, and Renal blood flow (RBF) and the Ferric reducing ability of plasma (FRAP) level which had decreased compared to the control group as a result of treatment with gentamicin.

Conclusion The above result indicated that ZM extract improved renal toxicity of gentamicin via reducing oxidative stress, oxygen-free radicals, and lipid peroxidation.
Risk factors for allograft failure in liver transplant recipients
Authors: Huesing-Kabar Anna , Dohna Christina zu , Heinzow Hauke , Cicinnati Vito , Beckebaum Susanne , Schmidt Martina , Gerth Hans , Pohlen Michele , Wilms Christian , Palmes Daniel , Schmidt Hartmut , Kabar Iyad
Published: January 2018

Background With regard to quality of life and organ shortage, follow-up after liver transplantation (LT) should consider risk factors for allograft failure in order to avoid the need for re-LT and to improve the long-term outcome of recipients. Therefore, the aim of this study was to explore potential risk factors for allograft failure after LT.

Material and methods A total of 489 consecutive LT recipients who received follow-up care at the University Hospital of Muenster were included in this study. Database research was performed, and patient data were retrospectively reviewed. Risk factors related to donor and recipient characteristics potentially leading to allograft failure were statistically investigated using binary logistic regression analysis. Graft failure was determined as graft cirrhosis, need for re-LT because of graft dysfunction, and/or allograft-associated death.

Results The mean age of recipients at the time of LT was 50.3 ± 12.4 years, and 64.0 % were male. The mean age of donors was 48.7 ± 15.5 years. Multivariable statistical analysis revealed male recipient gender (p = 0.04), hepatitis C virus infection (HCV) (p = 0.014), hepatocellular carcinoma (HCC) (p = 0.03), biliary complications after LT (p < 0.001), pretransplant diabetes mellitus (p = 0.03), and/or marked fibrosis in the initial protocol biopsy during follow-up (p = 0.001) to be recipient-related significant and independent risk factors for allograft failure following LT.

Conclusion Male recipients, patients who received LT for HCV or HCC, those with pretransplant diabetes mellitus, and LT recipients with biliary complications are at high risk for allograft failure and thus should be monitored closely.
High breakdown electric field in β-Ga2O3/graphene vertical barristor heterostructure
Authors: Yan Xiaodong , Esqueda Ivan S. , Ma Jiahui , Tice Jesse , Wang Han
Published: January 2018

In this work, we study the high critical breakdown field in β-Ga2O3 perpendicular to its (100) crystal plane using a β-Ga2O3/graphene vertical heterostructure. Measurements indicate a record breakdown field of 5.2 MV/cm perpendicular to the (100) plane that is significantly larger than the previously reported values on lateral β-Ga2O3 field-effect-transistors (FETs). This result is compared with the critical field typically measured within the (100) crystal plane, and the observed anisotropy is explained through a combined theoretical and experimental analysis.
Perspective: Theory of quantum transport in molecular junctions
Authors: Thoss Michael , Evers Ferdinand
Published: January 2018

Molecular junctions, where single molecules are bound to metal or semiconductor electrodes, represent a unique architecture to investigate molecules in a distinct nonequilibrium situation and, in a broader context, to study basic mechanisms of charge and energy transport in a many-body quantum system at the nanoscale. Experimental studies of molecular junctions have revealed a wealth of interesting transport phenomena, the understanding of which necessitates theoretical modeling. The accurate theoretical description of quantum transport in molecular junctions is challenging because it requires methods that are capable to describe the electronic structure and dynamics of molecules in a condensed phase environment out of equilibrium, in some cases with strong electron-electron and/or electronic-vibrational interaction. This perspective discusses recent progress in the theory and simulation of quantum transport in molecular junctions. Furthermore, challenges are identified, which appear crucial to achieve a comprehensive and quantitative understanding of transport in these systems.
Observation of two coupled Faraday waves in a vertically vibrating Hele-Shaw cell with one of them oscillating horizontally
Authors: Li Xiaochen , Li Xiaoming , Liao Shijun
Published: January 2018

A system of two coupled Faraday waves is experimentally observed at the two interfaces of the three layers of fluids (air, pure ethanol, and silicon oil) in a covered Hele-Shaw cell with periodic vertical vibration. Both the upper and lower Faraday waves are subharmonic, but they coexist in different forms: the upper one vibrates vertically, while the crests of the lower one oscillate horizontally with unchanged wave height, and the troughs of the lower one usually remain in the same place (relative to the basin). Besides, they are strongly coupled: the wave height of the lower Faraday waves is either a linear function (when forcing frequency is fixed) or a parabolic function (when acceleration amplitude is fixed) of that of the upper one with a same wavelength.
Near-field multiple traps of paraxial acoustic vortices with strengthened gradient force generated by sector transducer array
Authors: Wang Qingdong , Li Yuzhi , Ma Qingyu , Guo Gepu , Tu Juan , Zhang Dong
Published: January 2018

In order to improve the capability of particle trapping close to the source plane, theoretical and experimental studies on near-field multiple traps of paraxial acoustic vortices (AVs) with a strengthened acoustic gradient force (AGF) generated by a sector transducer array were conducted. By applying the integration of point source radiation, numerical simulations for the acoustic fields generated by the sector transducer array were conducted and compared with those produced by the circular transducer array. It was proved that strengthened AGFs of near-field multiple AVs with higher peak pressures and smaller vortex radii could be produced by the sector transducer array with a small topological charge. The axial distributions of the equivalent potential gradient indicated that the AGFs of paraxial AVs in the near field were much higher than those in the far field, and the distances at the near-field vortex antinodes were also proved to be the ideal trapping positions with relatively higher AGFs. With the established 8-channel AV generation system, theoretical studies were also verified by the experimental measurements of pressure and phase for AVs with various topological charges. The formation of near-field multiple paraxial AVs was verified by the cross-sectional circular pressure distributions with perfect phase spirals around central pressure nulls, and was also proved by the vortex nodes and antinodes along the center axis. The favorable results demonstrated the feasibility of generating near-field multiple traps of paraxial AVs with strengthened AGF using the sector transducer array, and suggested the potential applications of close-range particle trapping in biomedical engineering.
Solving the incompressible surface Navier-Stokes equation by surface finite elements
Authors: Reuther Sebastian , Voigt Axel
Published: January 2018

We consider a numerical approach for the incompressible surface Navier-Stokes equation on surfaces with arbitrary genus g(S). The approach is based on a reformulation of the equation in Cartesian coordinates of the embedding R3, penalization of the normal component, a Chorin projection method, and discretization in space by surface finite elements for each component. The approach thus requires only standard ingredients which most finite element implementations can offer. We compare computational results with discrete exterior calculus simulations on a torus and demonstrate the interplay of the flow field with the topology by showing realizations of the Poincaré-Hopf theorem on n-tori.
Large eddy simulation of rotating turbulent flows and heat transfer by the lattice Boltzmann method
Authors: Liou Tong-Miin , Wang Chun-Sheng
Published: January 2018

Due to its advantage in parallel efficiency and wall treatment over conventional Navier-Stokes equation-based methods, the lattice Boltzmann method (LBM) has emerged as an efficient tool in simulating turbulent heat and fluid flows. To properly simulate the rotating turbulent flow and heat transfer, which plays a pivotal role in tremendous engineering devices such as gas turbines, wind turbines, centrifugal compressors, and rotary machines, the lattice Boltzmann equations must be reformulated in a rotating coordinate. In this study, a single-rotating reference frame (SRF) formulation of the Boltzmann equations is newly proposed combined with a subgrid scale model for the large eddy simulation of rotating turbulent flows and heat transfer. The subgrid scale closure is modeled by a shear-improved Smagorinsky model. Since the strain rates are also locally determined by the non-equilibrium part of the distribution function, the calculation process is entirely local. The pressure-driven turbulent channel flow with spanwise rotation and heat transfer is used for validating the approach. The Reynolds number characterized by the friction velocity and channel half height is fixed at 194, whereas the rotation number in terms of the friction velocity and channel height ranges from 0 to 3.0. A working fluid of air is chosen, which corresponds to a Prandtl number of 0.71. Calculated results are demonstrated in terms of mean velocity, Reynolds stress, root mean square (RMS) velocity fluctuations, mean temperature, RMS temperature fluctuations, and turbulent heat flux. Good agreement is found between the present LBM predictions and previous direct numerical simulation data obtained by solving the conventional Navier-Stokes equations, which confirms the capability of the proposed SRF LBM and subgrid scale relaxation time formulation for the computation of rotating turbulent flows and heat transfer.
Magnetic plasma expulsion
Authors: Phillips R. E. , Ordonez C. A.
Published: January 2018

Magnetic confinement of plasmas is widely studied for restricting a plasma's extent to a given region. Presented here is one scheme for what is referred to as magnetic plasma expulsion, which would prevent the plasma from entering a given region. Magnetic plasma expulsion techniques may allow instrumentation access to the interiors of plasmas. Magnetic plasma expulsion techniques may also make alternative approaches for magnetic plasma confinement possible. Particle-in-cell simulation with the Warp code is used to study magnetic plasma expulsion. Some conditions for achieving magnetic plasma expulsion are reported.
Magnetic properties of Pr-Fe-B thick-film magnets deposited on Si substrates with glass buffer layer
Authors: Nakano M. , Kurosaki A. , Kondo H. , Shimizu D. , Yamaguchi Y. , Yamashita A. , Yanai T. , Fukunaga H.
Published: January 2018

In order to improve the magnetic properties of PLD-made Pr-Fe-B thick-film magnets deposited on Si substrates, an adoption of a glass buffer layer was carried out. The glass layer could be fabricated under the deposition rate of approximately 70 μm/h on a Si substrate using a Nd-YAG pulse laser in the vacuum atmosphere. The use of the layer enabled us to reduce the Pr content without a mechanical destruction and enhance (BH)max value by approximately 20 kJ/m3 compared with the average value of non-buffer layered Pr-Fe-B films with almost the same thickness. It is also considered that the layer is also effective to apply a micro magnetization to the films deposited on Si ones.
Tailoring the electronic properties of Ca2RuO4 via epitaxial strain
Authors: Dietl C. , Sinha S. K. , Christiani G. , Khaydukov Y. , Keller T. , Putzky D. , Ibrahimkutty S. , Wochner P. , Logvenov G. , van Aken P. A. , Kim B. J. , Keimer B.
Published: January 2018

We establish strain engineering of ruthenium oxides as a method to controllably induce phase transitions between electronic ground states with vastly different electrical and magnetic properties. Specifically, we show that the epitaxial strain acting on Ca2RuO4 thin films on NdCaAlO4 (110), LaAlO3 (100), and LaSrAlO4 (001) substrates induces a transition from the Mott-insulating phase of bulk Ca2RuO4 into a metallic phase. Magnetometry and spin-polarized neutron reflectometry reveal a low-temperature, small-moment ferromagnetic state in Ca2RuO4 films on LaAlO3 (100) and LaSrAlO4(001). Thin-film structures may open up new ways to investigate and utilize the electronic response of ruthenates to lattice modification.
Effect of chitosan coating on the structural and magnetic properties of MnFe2O4 and Mn0.5Co0.5Fe2O4 nanoparticles
Authors: Mdlalose W. B. , Mokhosi S. R. , Dlamini S. , Moyo T. , Singh M.
Published: January 2018

We report the influence of polymer coatings on structural and magnetic properties of MnFe2O4 and Mn0.5Co0.5Fe2O4 nanoferrites synthesized by glycol thermal technique and then coated with chitosan viz. CHI-MnFe2O4 and CHI-Mn0.5Co0.5Fe2O4. The compounds were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), high-resolution scanning electron microscopy (HRSEM), Mössbauer spectroscopy and magnetization measurements. The powder XRD patterns of naked nanoferrites confirmed single-phase spinel cubic structure with an average crystallite size of 13 nm, while the coated samples exhibited an average particle size of 15 nm. We observed a reduction in lattice parameters with coating. HRTEM results correlated well with XRD results. 57Fe Mössbauer spectra showed ordered magnetic spin states in both nanoferrites. This study shows that coatings have significant effects on the structural and magnetic properties of Mn-nanoferrites. Magnetization studies performed at room temperature in fields up to 14 kOe revealed the superparamagnetic nature of both naked and coated nanoparticles with spontaneous magnetizations at room temperature of 49.2 emu/g for MnFe2O4, 23.6 emu/g for coated CHI–MnFe2O4 nanoparticles, 63.2 emu/g for Mn0.5Co0.5Fe2O4 and 33.2 emu/g for coated CHI–Mn0.5Co0.5Fe2O4 nanoparticles. We observed reduction in coercive fields due to coating. Overall, chitosan-coated manganese and manganese-cobalt nanoferrites present as suitable candidates for biomedical applications owing to physicochemical, and magnetic properties exhibited.
Losses analysis of soft magnetic ring core under sinusoidal pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) excitations
Authors: Gao Hezhe , Li Yongjian , Wang Shanming , Zhu Jianguo , Yang Qingxin , Zhang Changgeng , Li Jingsong
Published: January 2018

Practical core losses in electrical machines differ significantly from those experimental results using the standardized measurement method, i.e. Epstein Frame method. In order to obtain a better approximation of the losses in an electrical machine, a simulation method considering sinusoidal pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) waveforms is proposed. The influence of the pulse width modulation (PWM) parameters on the harmonic components in SPWM and SVPWM is discussed by fast Fourier transform (FFT). Three-level SPWM and SVPWM are analyzed and compared both by simulation and experiment. The core losses of several ring samples magnetized by SPWM, SVPWM and sinusoidal alternating current (AC) are obtained. In addition, the temperature rise of the samples under SPWM, sinusoidal excitation are analyzed and compared.
Thermal stability of atomic layer deposited WCxNy electrodes for metal oxide semiconductor devices
Authors: Zonensain Oren , Fadida Sivan , Fisher Ilanit , Gao Juwen , Danek Michal , Eizenberg Moshe
Published: January 2018

This study is a thorough investigation of the chemical, structural, and electrical stability of W based organo-metallic films, grown by atomic layer deposition, for future use as gate electrodes in advanced metal oxide semiconductor structures. In an earlier work, we have shown that high effective work-function (4.7 eV) was produced by nitrogen enriched films (WCxNy) dominated by W-N chemical bonding, and low effective work-function (4.2 eV) was produced by hydrogen plasma resulting in WCx films dominated by W-C chemical bonding. In the current work, we observe, using x-ray diffraction analysis, phase transformation of the tungsten carbide and tungsten nitride phases after 900 °C annealing to the cubic tungsten phase. Nitrogen diffusion is also observed and is analyzed with time-of-flight secondary ion mass spectroscopy. After this 900 °C anneal, WCxNy effective work function tunability is lost and effective work-function values of 4.7–4.8 eV are measured, similar to stable effective work function values measured for PVD TiN up to 900 °C anneal. All the observed changes after annealing are discussed and correlated to the observed change in the effective work function.
Spin-orbit beams for optical chirality measurement
Authors: Samlan C. T. , Suna Rashmi Ranjan , Naik Dinesh N. , Viswanathan Nirmal K.
Published: January 2018

Accurate measurement of chirality is essential for the advancement of natural and pharmaceutical sciences. We report here a method to measure chirality using non-separable states of light with geometric phase-gradient in the circular polarization basis, which we refer to as spin-orbit beams. A modified polarization Sagnac interferometer is used to generate spin-orbit beams wherein the spin and orbital angular momentum of the input Gaussian beam are coupled. The out-of-phase interference between counter-propagating Gaussian beams with orthogonal spin states and lateral-shear or/and linear-phase difference between them results in spin-orbit beams with linear and azimuthal phase gradient. The spin-orbit beams interact efficiently with the chiral medium, inducing a measurable change in the center-of-mass of the beam, using the polarization rotation angle and hence the chirality of the medium are accurately calculated. Tunable dynamic range of measurement and flexibility to introduce large values of orbital angular momentum for the spin-orbit beam, to improve the measurement sensitivity, highlight the techniques' versatility.
Photo-conductive detection of continuous THz waves via manipulated ultrafast process in nanostructures
Authors: Moon Kiwon , Lee Eui Su , Lee Il-Min , Park Dong Woo , Park Kyung Hyun
Published: January 2018

Time-domain and frequency-domain terahertz (THz) spectroscopy systems often use materials fabricated with exotic and expensive methods that intentionally introduce defects to meet short carrier lifetime requirements. In this study, we demonstrate the development of a nano-photomixer that meets response speed requirements without using defect-incorporated, low-temperature-grown (LTG) semiconductors. Instead, we utilized a thin InGaAs layer grown on a semi-insulating InP substrate by metal-organic chemical vapor deposition (MOCVD) combined with nano-electrodes to manipulate local ultrafast photo-carrier dynamics via a carefully designed field-enhancement and plasmon effect. The developed nano-structured photomixer can detect continuous-wave THz radiation up to a frequency of 2 THz with a peak carrier collection efficiency of 5%, which is approximately 10 times better than the reference efficiency of 0.4%. The better efficiency results from the high carrier mobility of the MOCVD-grown InGaAs thin layer with the coincidence of near-field and plasmon-field distributions in the nano-structure. Our result not only provides a generally applicable methodology for manipulating ultrafast carrier dynamics by means of nano-photonic techniques to break the trade-off relation between the carrier lifetime and mobility in typical LTG semiconductors but also contributes to mass-producible photo-conductive THz detectors to facilitate the widespread application of THz technology.
Linear and nonlinear magneto-optical properties of monolayer MoS2
Authors: Nguyen Chuong V. , Hieu Nguyen N. , Muoi Do , Duque Carlos A. , Feddi Elmustapha , Nguyen Hieu V. , Phuong Le T. T. , Hoi Bui D. , Phuc Huynh V.
Published: January 2018

In this work, using the compact density matrix approach, we study the linear and nonlinear magneto-optical properties of monolayer molybdenum disulfide (MoS2) via an investigation of the absorption coefficients (MOACs) and refractive index changes (RICs). The results are presented as functions of photon energy and external magnetic field. Our results show that the MOACs and the RICs appear as a series of peaks in the inter-band transitions between Landau levels, while the intra-band transitions result in only one peak. Because of the strong spin-orbit coupling, the peaks caused by the spin-up and -down states are different. With the increase in the magnetic field, both MOACs and RICs give a blue-shift and reduce in their amplitudes. These results suggest a potential application of monolayer MoS2 in the optoelectronic technology, magneto-optical, valleytronic, and spintronic devices.
Resonant enhancement of accelerating gradient with silicon dual-grating structure for dielectric laser acceleration of subrelativistic electrons
Authors: Chen Zhaofu , Koyama Kazuyoshi , Uesaka Mitsuru , Yoshida Mitsuhiro , Zhang Rui
Published: January 2018

We show that the accelerating gradient of a dual-grating structure for dielectric laser acceleration of subrelativistic electrons can be enhanced by resonating with the zeroth diffraction order inside the channel. We analyze diffraction of light at a subwavelength grating (SWG) to illustrate the principle of the resonant enhancement. We present examples of dual-grating resonators for 50 keV electrons with different channel widths. The dependence of reflectivity and phase on the SWG dimensions provides flexibility in controlling the enhancement factor and filling time, thus enabling high-gradient acceleration driven by ultrashort low-power laser pulses.
Color-tunable light emission of SrLa4-x-ySi3O13:xTb3+, yEu3+ phosphors by energy transfer process for warm white LEDs
Authors: Peng Bing , Song Kaixin , Zhang Shuangshuang , Shen Shaohua , Xu Junming , Wu Jun , Su Weitao
Published: January 2018

SrLa4-x-ySi3O13: xTb3+, yEu3+ phosphor was prepared by high temperature solid-state method. The luminescent centers of Eu3+ and Tb3+ occupying La3+ lattice sites in hosts were confirmed by Rietevld refinement method. The phenomenon of self-cross-relaxation energy transfer is observed between Tb3+ ions from 5D4-7FJ to 7F6-5D4 transition. Additionally, the direction of energy transfer (ET) was observed from Tb3+ to Eu3+ ions, and ET efficiency became more efficient as the concentration of activator increases. The type of ET between Tb3+ and Eu3+ ions was demonstrated to be the dipole-dipole mechanism. The multi-color lights were realized covering the green to red visible region by the route of energy transfer. Furthermore, the decrease of Eu3+ emission intensity resulting from thermal quenching can be effectively compensated by Tb3+→Eu3+ ET. The excellent luminescent properties and thermal stability show this phosphor to be a promising candidate for white LEDs.
Reduction of electron heating by magnetizing ultracold neutral plasma
Authors: Tiwari Sanat Kumar , Baalrud Scott D.
Published: January 2018

Electron heating in a magnetized ultracold neutral plasma is modeled using classical molecular dynamics simulations. A sufficiently strong magnetic field is found to reduce disorder induced heating and three body recombination heating of electrons by constraining electron motion, and therefore heating, to the single dimension aligned with the magnetic field. A strong and long-lasting temperature anisotropy develops, and the overall kinetic electron temperature is effectively reduced by a factor of three. These results suggest that experiments may increase the effective electron coupling strength using an applied magnetic field.
Efficiency of mating, artificial insemination or resynchronisation at different times after first timed artificial insemination in postpartum Nellore cows to produce crossbred calves
Authors: Rodrigues Walvonvitis Baes , Jara Jean do Prado , Borges Juliana Correa , Fialho de Oliveira Luiz Orcirio , Gomes de Abreu Urbano Pinto , Anache Natalia Albanese , Casanova da Silva Karine , Bezerra Alexandre de Oliveira , Cardoso Christopher Junior Tavares , Nogueira Eriklis
Published: January 2018

The objective of this trial was to evaluate different post-timed artificial insemination (TAI) reproductive managements in postpartum beef cows to produce crossbred calves from artificial insemination (AI). Nellore cows (n = 607), with 45 days postpartum, were inseminated at a fixed time, using a protocol that included an intravaginal progesterone-releasing device along with oestradiol benzoate, prostaglandin, equine chorionic gonadotropin, and oestradiol cypionate, followed TAI 48 h post-device removal. Four post-TAI treatments were evaluated: in CONTROL (T1, n = 161), cows were exposed to Nellore clean-up bulls until the end of the breeding season (75 days). In OBSERVATION (T2, n = 132), heat detection was performed for 15–25 days post-TAI, followed by AI. In RESYNC22 (T3, n = 157) and RESYNC30 (T4, n = 157), resynchronisation started after 22 or 30 days, following second TAI at Day 32 or 40 days after first TAI. In T2, T3 and T4, after the second AI, cows were exposed to Nellore clean-up bulls until the end of the breeding season (75 days). The pregnancy rate (PR) for the first TAI did not differ (54.6%, 53.0%, 59.2%, and 51.6% for CONTROL, OBSERVATION, RESYNC 22, and RESYNC 30, respectively; P = 0.66), and no difference was observed for the second TAI (RESYNC 22 = 45.31% and RESYNC30 = 46.05%; P = 0.137), in the PR at the end of the breeding season (86.33%, 86.36%, 78.98%, and 81.52%, P = 0.43), or embryonic losses (4.54%, 2.85%, 6.45% and 7.40%, respectively; P = 0.61), but the percentage of crossbred pregnancy was higher in groups with resynchronisation (RESYNC22 and RESYNC30) than CONTROL and OBSERVATION (98.38%, 90.62%, 63.30%, 78.95%, P < 0.001). In conclusion, resynchronisation programs of 22 or 30 days are more efficient to produce AI products, and the final pregnancy rate is similar among the treatments, differing only in the amount of calves produced by AI.
Spatiotemporal variation in the structure of reef fish and macroalgal assemblages in a north-east Atlantic kelp forest ecosystem: implications for the management of temperate rocky reefs
Authors: Pita Pablo , Fernández-Márquez Diana , Freire Juan
Published: January 2018

Temperate rocky reefs and kelp forest ecosystems have been severely affected by overfishing, pollution and habitat destruction, and climate change is a major driver of kelp decline in many regions. Although necessary for management, ecological interactions between kelp and fish remain largely unknown in the north-east Atlantic. In the present study, underwater visual censuses (UVC) and univariate and multivariate multiple regression models were used to analyse the spatiotemporal variations in the abundance and habitat use of the rocky reef fish and macroalgae assemblages of Galicia (north-west Spain). The underwater seascape was dominated by large rocks and kelp forests of Laminaria hyperborea, L. ochroleuca and Saccorhiza polyschides. Fish assemblages were ruled by gadids, labrids and sparids. The most frequent fish species were Labrus bergylta (counted in 90% of UVC) and Pollachius pollachius (in 100% of UVC), whereas the most abundant were Boops boops (mean±s.d., 556.4±39.7 individuals ha–1) and L. bergylta (432.10±440.05 individuals ha–1). Fish and macroalgal assemblages showed different spatial preferences and responded strongly to seasonality, wave exposure and depth. To a lesser degree, fish and macroalgal assemblages showed preferences for habitat structure. Moreover, because the findings of the present study indicate that L. bergylta is a good indicator species of the health of rocky reef and kelp forests ecosystems, monitoring of this fish can be helpful for management and conservation actions.
Can bioturbation be responsible for thicker freshwater lenses than expected in littoral environments?
Authors: Carol E. , Richiano S. , Tanjal C.
Published: January 2018

A study of hydrological and lithological characteristics that allow the development of freshwater lenses in littoral ridges underneath clay sediments of the coastal plain was undertaken, considering as a case of study the freshwater lenses located in the coastal sector of Samborombón Bay (Argentina). Geological characteristics were studied at a regional scale, as well as detailed sedimentological and ichnological aspects. Thickness of the lens and the freshwater–saline water interface were determined by salinity measurements in exploration wells located at different depths. Results obtained suggest that the infiltration of rainwater into the littoral ridges causes the formation of freshwater lenses that deepen below the clayey layers of the coastal-plain deposits. The key to answering this question are the crustacean burrows, which regionally occur in the fine sediments of the coastal plain. The burrows create an interconnected system of galleries and tunnels filled with sandy-silt material that favours seepage. Because the alternation of coastal-plain deposits and littoral ridges is a frequent situation throughout the world, the data provided by the present work do not represent just a simple case study; on the contrary, they show that biological structures promote bigger freshwater lenses in coastland environments, thus increasing water reserves.
Rogue waves and large deviations in deep sea
Authors: Dematteis Giovanni , Grafke Tobias , Vanden-Eijnden Eric
Published: January 2018

Significance

Quantifying the departure from Gaussianity of the wave-height distribution in the seas and thereby estimating the likelihood of appearance of rogue waves is a long-standing problem with important practical implications for boats and naval structures. Here, a procedure is introduced to identify ocean states that are precursors to rogue waves, which could permit their early detection. Our findings indicate that rogue waves obey a large deviation principle—i.e., they are dominated by single realizations—which our method calculates by solving an optimization problem. The method generalizes to estimate the probability of extreme events in other deterministic dynamical systems with random initial data and/or parameters, by using prior information about the nature of their statistics.
Supercritical CO
2
uptake by nonswelling phyllosilicates
Authors: Wan Jiamin , Tokunaga Tetsu K. , Ashby Paul D. , Kim Yongman , Voltolini Marco , Gilbert Benjamin , DePaolo Donald J.
Published: January 2018

Significance

Reliable estimates of geologic carbon storage capacities (needed for policymaking) in both saline aquifers and unconventional gas/oil shales rely on understanding trapping mechanisms. We found that CO
2
uptake by muscovite (a common mineral and a conservative proxy for illite) far exceeds the maximum adsorption capacity of its external surface area. Our measurements using different methods collectively suggest that CO
2
enters muscovite interlayers without bulk interlayer expansion, contrary to the conventional wisdom that only swelling clays take up CO
2
into interlayers. Because the nonswelling illitic clay is the major clay mineral in deep subsurface tight rocks, their excess uptake of CO
2
may significantly contribute to CO
2
storage capacity and warrants further in-depth studies.
Biodegradable Piezoelectric Force Sensor
Authors: Curry Eli J. , Ke Kai , Chorsi Meysam T. , Wrobel Kinga S. , Miller Albert N. , Patel Avi , Kim Insoo , Feng Jianlin , Yue Lixia , Wu Qian , Kuo Chia-Ling , Lo Kevin W.-H. , Laurencin Cato T. , Ilies Horea , Purohit Prashant K. , Nguyen Thanh D.
Published: January 2018

Significance

Measuring physiological pressures such as lung pressure, brain pressure, eye pressure, etc. is important for monitoring health status, preventing the buildup of dangerous internal forces in impaired organs, and enabling novel approaches of using mechanical stimulation for tissue regeneration. Pressure sensors are often implanted and directly integrated with soft biological systems. Therefore, the devices should be flexible and at the same time biodegradable to avoid invasive removal surgery. Here, we present the study and processing of a biodegradable polymer which can convert mechanical force to electricity, and employ the polymer to develop a biocompatible implanted force sensor. The sensor, relying solely on common medical materials, can monitor important biological forces and eventually self-vanish, causing no harm to the body.
Local policy proposals can bridge Latino and (most) white Americans’ response to immigration
Authors: Huo Yuen J. , Dovidio John F. , Jiménez Tomás R. , Schildkraut Deborah J.
Published: January 2018

Significance

Subnational immigrant policies (i.e., those instituted at the state level in the United States) are not only key to successful integration, they send a message about who belongs. Our evidence suggests that welcoming state-level immigrant policies lead to greater belonging among foreign-born Latinos, US-born Latinos, and even US-born whites. Only self-identified politically conservative whites showed depressed feelings of belonging when state policies support immigrants. Patterns remained constant across states that vary in their historic reception of immigrants (Arizona and New Mexico). These findings suggest that debates about the polarizing effects of immigration policies by racial group are misplaced. With a majority of whites nationally identifying as either liberal or moderate, welcoming immigration policies have direct and spillover effects that can further national unity.