bluuebunny/crossref_metadata_2025 huggingface dataset:
4H Leukodystrophy: Lessons from 3T Imaging
Authors: Cayami Ferdy , Bugiani Marianna , Pouwels Petra , Bernard Geneviève , van der Knaap Marjo , Wolf Nicole
Published: November 2017

4H leukodystrophy is characterized by hypomyelination, hypodontia, and hypogonadotropic hypogonadism. With its variability in clinical symptoms, application of pattern recognition to identify specific magnetic resonance imaging (MRI) features proved useful for the diagnosis. We collected 3T MR imaging data of 12 patients with mutations in POLR3A (n = 8), POLR3B (n = 3), and POLR1C (n = 1), all obtained at the same scanner. We assessed these images and compared them with previously obtained 1.5T images in 8 patients. Novel MRI findings were myelin islets, closed eye sign, and a cyst-like lesion in the splenium. Myelin islets were variable numbers of small T1 hyperintense and T2 hypointense dots, mostly in the frontal and parietal white matter, and present in all patients. This interpretation was supported with perivascular staining of myelin protein in the hypomyelinated white matter of a deceased 4H patient. All patients had better myelination of the medial lemniscus with a relatively hypointense signal of this structure on axial T2-weighted (T2W) images (“closed eye sign”). Five patients had a small cyst-like lesion in the splenium. In 10 patients with sagittal T2W images, we also found spinal cord hypomyelination. In conclusion, imaging at 3T identified additional features in 4H leukodystrophy, aiding the MRI diagnosis of this entity.
Gap-Balancing versus Measured Resection Technique in Total Knee Arthroplasty: A Comparison Study
Authors: Churchill Jessica , Khlopas Anton , Sultan Assem , Harwin Steven , Mont Michael
Published: November 2017

Proper femoral component alignment in the axial plane during total knee arthroplasty (TKA) depends on accurate bone cuts and soft tissue balancing. Two methods that are used to achieve this are “measured resection” and “gap balancing.” However, a controversy exists as to which method is more accurate and leads to better outcomes. Therefore, the purpose of this study was to evaluate: (1) implant survivorship, (2) patient outcomes, (3) complications, and (4) radiographic analysis comparing patients who underwent TKA with either gap-balancing or measured resection techniques. A total of 214 consecutive patients (221 knees) underwent primary TKA by a single surgeon between 2011 and 2012. Component alignment was achieved by using measured resection in 116 knees and gap balancing was used in 105 knees. The patients had a mean age of 66 years (range, 44–86 years) and a mean body mass index of 32 kg/m2 (range, 22–52 kg/m2). Patient range-of-motion (ROM) and Knee Society (KS) function and pain scores, and radiographic assessment, were assessed preoperatively and postoperatively at ∼6 weeks, 3 months, 1 year, and then annually. The mean follow-up time was 3 years. A Kaplan–Meier's analysis was performed to calculate the survivorship. The aseptic survivorship was 98% in both the measured resection and gap-balancing groups. The mean ROM was not significantly different between the measured resection and gap-balancing groups (123 vs. 123 degrees, p = 0.990). There were no significant differences between the two groups in terms of the KS function scores (86 vs. 85 points, p = 0.829) or the KS pain scores (93 vs. 92 points, p = 0.425). Otherwise, the radiographic evaluation at latest follow-up did not demonstrate any evidence of progressive radiolucencies or loosening, of any prosthesis. The results of this study found that at a mean follow-up of 3 years, both the measured resection and gap-balancing techniques achieved excellent survivorship and postoperative outcomes. This demonstrates that both methods can be used to achieve accurate femoral component alignment with similar short-term outcomes.
Coronal Correction for Severe Deformity Using Robotic-Assisted Total Knee Arthroplasty
Authors: Marchand Robert , Sodhi Nipun , Khlopas Anton , Sultan Assem , Higuera Carlos , Stearns Kim , Mont Michael
Published: November 2017

Although robotic-assisted total knee arthroplasty (TKA) has the potential to accurately reproduce neutral alignment, it is still unclear if this correction is attainable in patients who have severe varus or valgus deformities. Therefore, the purpose of this study was to assess a single surgeon's experience with correcting coronal deformities using the robotic-assisted TKA device. Specifically, we looked at correction of varying degrees of varus and valgus deformity in patients who underwent robotic arm-assisted TKA. A total of 330 robotic-assisted TKA cases performed by a single surgeon were analyzed. Preoperative CT scans were registered to the robotic-assisted software to create a three-dimensional rendering from which coronal alignment was measured. Postoperative coronal alignment measurements were taken in the operating room using the robotic-assisted device after trial component placement. The robotic-assisted device uses optical tracking from navigation probes placed on the distal femur and proximal tibia. The robotic-assisted software can register these probes as bony landmarks to measure coronal alignment in the distal plane of the femoral component and proximal plane of the tibial component. A total of 261 cases were of varus knees, 46 cases were of valgus knees, and 23 cases had 0° preoperative alignment. Severe deformity was defined as 7° or greater deformity. Preoperative neutral alignment was defined as 0°, while postoperative neutral alignment was defined as 0° ± 3°. There were 129 patients with and initial severe varus and 7 patients with an initial severe valgus deformity of 7° or greater. Patients were divided into varus or valgus cohorts, and analysis was performed on the overall cohort, as well as nonsevere (<7°) and severe (7° or greater) deformity cohorts.

All 132 knees with initial varus deformity of less than 7° were corrected to neutral (mean 1°, range -1–3°). A total of 82 knees (64%) with 7° or greater varus deformity were corrected to neutral (mean 2°, range 0–3°). However, roughly 30% of patients with severe deformity who were not corrected to neutral were still corrected within a couple of degrees of neutral. There were seven knees with 7° or greater valgus deformity, and all were corrected to neutral (mean 2°, range 0–3°). This study demonstrated that all knees were corrected in the appropriate direction within a few degrees of neutral, and no knees were overcorrected. The implication of this ability to achieve alignment goals on clinical outcomes will need to be evaluated in future studies. The results from this study demonstrate the potential for the robotic-assisted device during TKA in helping surgeons achieve a preoperatively planned desired neutral alignment.
Outcome of Cesarean Myomectomy: Is it a Safe Procedure?
Authors: Senturk Mehmet , Polat Mesut , Doğan Ozan , Pulatoğlu Çiğdem , Yardımcı Oğuz , Karakuş Resul , Tayyar Ahter
Published: November 2017

Objective Myomectomy performed during cesarean section is still controversial because of the potential for associated complications, especially with large myomas. Many obstetricians avoid performing cesarean myomectomy procedures because of the risk of uncontrollable hemorrhage. However, the prevalence of pregnant women with myomas is increasing, leading to an increase in the likelihood that physicians will encounter this issue. The aim of this study was to compare outcomes and complications of patients who either had or did not have cesarean myomectomy.

Method A total of 361 patients were evaluated in this retrospective study. Patients who had cesarean section with myomectomy and patients had cesarean section without myomectomy were compared with regard to demographics, drop in hemoglobin levels, complications, blood transfusion rates and duration of operation. These parameters were also compared when the diameter of the myoma was larger than 5 cm. Values of p < 0.01 and p < 0.05 were considered statistically significant.

Results While maternal age and gravidity were similar in both groups (p > 0.05), the mean myoma diameter was smaller and the duration of operation was longer in the group who underwent cesarean myomectomy (p < 0.05). The reduction in hemoglobin level, rate of complications, and number of transfusions were similar in both groups (p > 0.05).

Conclusion This study shows that myomectomy during cesarean section does not increase complications or transfusion rates and appears to be a safe procedure.
Neue Therapieansätze bei entzündlichen Gelenkerkrankungen
Authors: Benesova Karolina , Kai Bender Niko , Lorenz Hanns-Martin
Published: November 2017

Nachdem in mehreren Phase-III-Studien die Wirksamkeit und Sicherheit gezeigt werden konnte, erhielten Anfang dieses Jahres die ersten beiden JAK-Inhibitoren (Baricitinib und Tofacitinib) auch in Deutschland die Zulassung zur Behandlung der mittelschweren bis schweren aktiven rheumatoiden Arthritis. Apremilast, ein selektiver Phosphodiesterase-4 (PDE4)-Inhibitor, wird seit Anfang 2015 als orale Therapie zur Behandlung der Psoriasis und Psoriasis-Arthritis eingesetzt. Bei Psoriasis-Arthritis führt Apremilast u. a. zu einer Verringerung des Schmerzes sowie einer Verbesserung der druckschmerzhaften und geschwollenen Gelenke, der Daktylitis und der Enthesitis. Secukinumab ist ein rekombinanter humaner monoklonaler Antikörper gegen Interleukin (IL)-17 A, der initial zur Behandlung erwachsener Patienten mit mittelschwerer bis schwerer Plaque-Psoriasis eingesetzt wurde. Im November 2015 hat die EMA die Zulassung von Secukinumab auf die Behandlung von Patienten mit aktiver Psoriasis-Arthritis und ankylosierender Spondylitis erweitert. Ustekinumab ist ein humaner monoklonaler Antikorper gegen IL-12/23 und seit 2009 für die Behandlung der Plaque-Psoriasis eingesetzt. Im September 2013 erhielt Ustekinumab durch die EMA auch die Zulassung für die Behandlung der Psoriasisarthritis.
Die akute und die elektive OP-Indikation
Authors: Henniger Martina , Kehl Gabriele , Rehart Stefan
Published: November 2017

Trotz verbesserter Therapiemöglichkeiten bedeutet die Diagnose „Rheumatoide Arthritis“ nach wie vor für den Patienten eine erhebliche physische und psychische Belastung. Zu den Krankheitssymptomen wie Schmerzen, lang anhaltende Morgensteifigkeit, Funktionsstörungen, Müdigkeit kommen die Notwendigkeit einer medikamentösen Dauertherapie und in vielen Fällen auch Operationen. Häufig leiden die Patienten unter Verunsicherung, Ängsten und Zweifeln, bei den jüngeren Patienten eher im Hinblick auf Berufswahl, Familienplanung oder Freizeitaktivitäten, bei den älteren Patienten im Hinblick auf Verlust von Mobilität und Selbstständigkeit. Hinsichtlich der Frage der operativen Intervention findet sich oft eine ambivalente Haltung der Patienten. Einerseits besteht bei persistierenden Schmerzen und Funktionseinschränkungen der Wunsch nach Besserung, andererseits bestehen Ängste hinsichtlich möglicher Komplikationen. Die meisten rheumaorthopädischen Operationen werden elektiv durchgeführt, sodass vor der geplanten Operation genügend Zeit bleibt, um den Patienten bestmöglich auf den Eingriff vorzubereiten. Schon bei der Indikationsstellung müssen zusätzliche Funktionsstörungen bei polyartikulärem Befall berücksichtigt werden, ggf. muss eine sinnvolle Reihenfolge von Operationen gemeinsam mit dem Patienten festgelegt werden. Risiken, individuelle Besonderheiten z.B. durch Voroperationen/Vorerkrankungen, der Umgang mit den Medikamenten, Alternativen zum Eingriff, postoperative Behandlung und das zu erwartende Ergebnis des Eingriffs sollten mit dem Patienten im Vorfeld ausführlich besprochen werden. Hilfreich für solche Gespräche ist es, wenn der Patient schriftlich entsprechende Informationen für den Arzt mit sich führt. Auch psychische Vorerkrankungen oder Belastungen sollten miteinbezogen werden, da das Outcome erheblich vom Vorhandensein positiver Copingmechanismen profitiert.
Learning curve and competence for volumetric laser endomicroscopy in Barrett’s esophagus using cumulative sum analysis
Authors: Trindade Arvind , Inamdar Sumant , Smith Michael , Rosen Lisa , Han Dennis , Chang Kenneth , Leggett Cadman , Lightdale Charles , Pleskow Douglas , Sejpal Divyesh , Tearney Guillermo , Thomas Rebecca , Wallace Michael
Published: November 2017

Background and study aims Little is known about the learning curve for image interpretation in volumetric laser endomicroscopy (VLE) in Barrett’s esophagus (BE). The goal of this study was to calculate the learning curve, competence of image interpretation, sensitivity, specificity, and accuracy of VLE among novice users.

Methods 31 novice users viewed 96 VLE images electronically at three academic institutions after a brief training session. There were 24 images of each histologic type: normal gastric cardia, normal esophageal squamous epithelium, non-neoplastic BE, and neoplastic BE. The users were asked to identify the correct tissue type and level of confidence. The cumulative summation (CUSUM) technique was used to construct a learning curve.

Results 22 (71 %) of the physicians achieved VLE interpretation competency during their 96-slide review. Half of the physicians achieved competency at 65 images (95 % confidence interval [CI] 45 – 85). There was a statistically significant association between confidence in diagnosis and selecting the correct histologic tissue type (P < 0.001). The median accuracy for esophageal squamous epithelium, normal gastric cardia, non-neoplastic BE, and neoplastic BE was 96 % (95 %CI 95 % – 96 %), 95 % (95 %CI 94 % – 96 %), 90 % (95 %CI 88 % – 91 %), 96 % (95 %CI 95 % – 96 %). The overall accuracy was 95 % (95 %CI 93 % – 95 %).

Conclusion The majority of novice users achieved competence in image interpretation of VLE for BE, using a pre-selected image set, with a favorable learning curve after a brief training session. An electronic review of VLE images, prior to real-time use of VLE, is encouraged.
Anti-inflammatory Effects of Canthin-6-one Alkaloids from Ailanthus altissima
Authors: Cho Seung-Kye , Jeong Miran , Jang Dae , Choi Jung-Hye
Published: November 2017

Canthin-6-one (CO) alkaloids possess various biological activities, including antibacterial, antitumor, antifungal, and antiviral activities. However, their anti-inflammatory effects and underlying molecular mechanisms are poorly characterized. This study aimed to investigate the anti-inflammatory effects of CO and its derivative 5-(1-hydroxyethyl)-canthin-6-one (5-HCO), isolated from the stem barks of Ailanthus altissima in lipopolysaccharide (LPS)-stimulated macrophages. CO (1 and 5 µM) and 5-HCO (7.5 and 15 µM) significantly inhibited the LPS-induced expression of inducible nitric oxide synthase. In addition, CO (1 and 5 µM) and 5-HCO (15 µM) markedly suppressed the production of prostaglandin E2 (PGE2) and expression of cyclooxygenase-2, a key enzyme in PGE2 synthesis, in LPS-stimulated macrophages. Moreover, CO treatment significantly reduced monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) expression, whereas 5-HCO inhibited MCP-1, but not TNF-α expression. Both CO and 5-HCO inhibited the phosphorylation of inhibitor kappa B and transcriptional activation of nuclear factor kappa B (NF-κB) in LPS-stimulated macrophages. In addition, CO, but not 5-HCO, markedly reduced Akt phosphorylation. Taken together, these data suggest that CO, but not 5-HCO with a hydroxyethyl moiety on the D ring, has potent anti-inflammatory activity in LPS-stimulated macrophages through the downregulation of both the NF-κB and the Akt pathway.
The future of the impact agenda depends on the revaluation of academic freedom
Authors: Holbrook J. Britt
Published: November 2017

Opponents of the impact agenda often base their arguments on the claim that requiring scholarly research to demonstrate broader societal impacts conflicts with academic freedom. This paper argues that this claim entails a narrow interpretation of academic freedom as freedom from interference. A richer interpretation is proposed of academic freedom as freedom to pursue research that may have broader impacts. Adopting a positive view of academic freedom will require disciplines to adjust their standards of academic rigor and universities to amend their criteria for promotion and tenure. It will also provide the foundation for an academic response to the rise of neopopulism.
Application of surface coil in nuclear magnetic resonance studies of physical properties of quasi-2D materials
Authors: Liu Wencong , Lu Lu , Mitrović V. F.
Published: November 2017

We conduct a comprehensive set of tests of performance of surface coils used for nuclear magnetic resonance (NMR) study of quasi-2-dimensional samples. We report 115In and 31P NMR measurements on InP, semi-conducting thin substrate samples. Surface coils of both zig-zag meander-line and concentric spiral geometries were used. We compare reception sensitivity and signal-to-noise ratio of the NMR signal obtained by using surface-type coils to that obtained by standard solenoid-type coils. As expected, we find that surface-type coils provide better sensitivity for NMR study of thin film samples. Moreover, we compare the reception sensitivity of different types of the surface coils. We identify the optimal geometry of the surface coils for a given application and/or direction of the applied magnetic field.
Possible observation of the Berezinskii-Kosterlitz-Thouless transition in boron-doped diamond films
Authors: Coleman Christopher , Bhattacharyya Somnath
Published: November 2017

The occurrence of the Berezinskii-Kosterlitz-Thouless (BKT) transition is investigated in heavily boron-doped nanocrystalline diamond films through a combination of current-voltage and resistance measurements. We observe transport features suggesting a robust BKT transition along with transport features related to vortex pinning in nanocrystalline diamond films with smaller grain size. The vortex core energy determined through analysis of the resistance temperature curves was found to be anti-correlated to the BKT transition temperatures. It is also observed that the higher BKT temperature is related to an increased vortex-antivortex binding energy derived from the activated transport regions. Further, the magnetic field induced superconductor insulator transition shows the possibility of the charge glass state. The consequences of granularity such as localization and vortex pinning can lead to tuneable BKT temperatures and strongly affects the field induced insulating state.
Lift and drag in three-dimensional steady viscous and compressible flow
Authors: Liu L. Q. , Wu J. Z. , Su W. D. , Kang L. L.
Published: November 2017

In a recent paper, Liu, Zhu, and Wu [“Lift and drag in two-dimensional steady viscous and compressible flow,” J. Fluid Mech. 784, 304–341 (2015)] present a force theory for a body in a two-dimensional, viscous, compressible, and steady flow. In this companion paper, we do the same for three-dimensional flows. Using the fundamental solution of the linearized Navier-Stokes equations, we improve the force formula for incompressible flows originally derived by Goldstein in 1931 and summarized by Milne-Thomson in 1968, both being far from complete, to its perfect final form, which is further proved to be universally true from subsonic to supersonic flows. We call this result the unified force theorem, which states that the forces are always determined by the vector circulation Γϕ of longitudinal velocity and the scalar inflow Qψ of transverse velocity. Since this theorem is not directly observable either experimentally or computationally, a testable version is also derived, which, however, holds only in the linear far field. We name this version the testable unified force formula. After that, a general principle to increase the lift-drag ratio is proposed.
Engineering of electronic properties of single layer graphene by swift heavy ion irradiation
Authors: Kumar Sunil , Kumar Ashish , Tripathi Ambuj , Tyagi Chetna , Avasthi D. K.
Published: November 2017

In this work, swift heavy ion irradiation induced effects on the electrical properties of single layer graphene are reported. The modulation in minimum conductivity point in graphene with in-situ electrical measurement during ion irradiation was studied. It is found that the resistance of graphene layer decreases at lower fluences up to 3 × 1011 ions/cm2, which is accompanied by the five-fold increase in electron and hole mobilities. The ion irradiation induced increase in electron and hole mobilities at lower fluence up to 1 × 1011 ions/cm2 is verified by separate Hall measurements on another irradiated graphene sample at the selected fluence. In contrast to the adverse effects of irradiation on the electrical properties of materials, we have found improvement in electrical mobility after irradiation. The increment in mobility is explained by considering the defect annealing in graphene after irradiation at a lower fluence regime. The modification in carrier density after irradiation is also observed. Based on findings of the present work, we suggest ion beam irradiation as a useful tool for tuning of the electrical properties of graphene.
Turbulent kinetic energy budgets in wall bounded flows with pressure gradients and separation
Authors: Schiavo Luiz A. C. A. , Wolf William Roberto , Azevedo João Luiz F.
Published: November 2017

Numerical simulations are employed to investigate the turbulent kinetic energy (TKE) budgets in turbulent channel flows with pressure gradients and separation. Incompressible, highly resolved large eddy simulations are performed for Reτ = 170 and 615 to investigate the flow developing along a convergent-divergent channel. The aim of this work is to analyze the TKE budgets both in physical and Fourier spaces to characterize the important scales in the individual processes in such turbulent flows. The study is performed for different positions along the channel where favorable and adverse pressure gradients are present. Proper orthogonal decomposition is employed to understand the role of the most energetic structures in the TKE budgets. Results indicate that such structures account for most of the turbulent effects present in the flow, except for the transport term. A spectral TKE equation in Fourier space is developed for flows with one homogeneous direction to characterize the turbulent processes as a function of the wavelength in the channel spanwise direction. The results show that viscous effects occur at the same range of wavelengths for which production is found and that TKE is transported to the near-wall region, being dissipated by large spanwise scale motion. They also show that favorable pressure gradients change the distribution of processes along the spanwise wavelengths. In the adverse pressure gradient region, TKE is transported both toward the wall and toward the center of the channel, where it is balanced by the advection term.
Reversal of spontaneous magnetization and spontaneous exchange bias for Sm1−xYxCrO3: The effect of Y doping
Authors: Zhang Hongguang , Wang Jianhua , Xie Liang , Fu Dexiang , Guo Yanyan , Li Yongtao
Published: November 2017

We report the crystal and electronic structures and magnetic properties of non-magnetic Y3+ ion doped SmCrO3 crystals. Structural distortion and electronic structure variation are caused by cation disorder due to Y doping. Although the spin moment of Sm3+ is diluted by nonmagnetic Y ions, spin reorientation continues to exist, and the temperature-dependent magnetization reversal effect and the spontaneous exchange bias effect under zero field cooling are simultaneously induced below Neel temperature. Significantly, the method of doping promotes the achievement of temperature dependent tunable switching of magnetization and sign of a spontaneous exchange bias from positive to negative. Our work provides more tunable ways to the sign reversal of magnetization and exchange bias, which have potential application in designing magnetic random access memory devices, thermomagnetic switches and spin-valve devices.
Interesting low temperature magneto-elastic behavior of a FINEMET metglass
Authors: Hossain Md. Sarowar , Hakim M. A. , Mukhopadhyay P. K.
Published: November 2017

We here report on studies of low temperature dynamic elastic properties of an amorphous ribbon of a FINEMET alloy, with and without magnetic field. Characterization with XRD and SEM showed that the sample was partially amorphous. Magnetization study showed the system as ferromagnetic and there was no transition in resistivity, anomalous peaks in sound velocity and internal friction measurements, with a small hysteresis and strong magnetic field dependence, were found in this temperature range. After analysing the data we concluded that it was magnetic in origin. This is reported for the first time in the FINEMET system.
Simulation of photoluminescence lifetime and open-circuit voltage in Cu(In,Ga)Se2 thin film solar cells
Authors: López Salas J. F. , Richter M. , Parisi J. , Heise S. J.
Published: November 2017

Time-resolved photoluminescence is an established method of investigating charge carrier lifetime in thin film solar cells. However, the correlation between photoluminescence lifetime and device efficiency is still not sufficiently clear. In this study, we work with the example of Cu(In,Ga)Se2 thin film solar cells to investigate this correlation in more detail. Using a simulation model capable of reproducing experimental results for time-resolved photoluminescence, current voltage characteristics, and quantum efficiency spectra, we have investigated the effect of single absorber parameters on the photoluminescence lifetime and open-circuit voltage. Our simulations show that differences in band gap grading of the absorber have a strong effect on the open-circuit voltage but do not alter the photoluminescence lifetime. On the other hand, a higher Shockley–Read–Hall recombination rate, caused by an increased defect state density or a decreased electron emission from trap states back to the conduction band, reduces both open-circuit voltage and photoluminescence lifetime simultaneously.
Magnetoresistance in doped Bi0.85Sb0.15 single crystals
Authors: Kozhemyakin G. N. , Zayakin S. A.
Published: November 2017

We have studied the influence of donor and acceptor doping on the magnetotransport properties in Bi0.85Sb0.15 single crystals, which show the properties of a topological band insulator. High-quality Bi0.85Sb0.15 single crystals with tellurium (Te) and tin (Sn) doping from 5 × 10−5 at. % to 10−3 at. % were grown using the Czochralski technique. High carrier mobilities up to 5.8 × 105 cm2 V−1 s−1 at 77 K were achieved in these single crystals. Doping Bi0.85Sb0.15 single crystal with Te at a level of 10−4 at. % gave the highest magnetoresistance at temperatures of 120–200 K. A very high magnetoresistance of 1640% was reached in Sn-doped (10−4 at. %) single crystals in a magnetic field of 1.15 T at 90 K. The influences of Te and Sn doping of Bi1–xSbx single crystals and of magnetic field on the thermal activation energy gap were studied. The observed high magnetoresistance in doped Bi0.85Sb0.15 single crystals could be useful for practical applications in magnetic sensors and multifunctional electromagnetic devices.
Confirmation of hot electron preheat with a Cu foam sphere on GEKKO-LFEX laser facility
Authors: Gong T. , Habara H. , Uematsu Y. , Hayashi Y. , Kawazu S. , Kubota Y. , Matsumoto T. , Nakaguchi S. , Noma S. , Otsuki T. , Tsujii A. , Yahata K. , Yoshida Y. , Arikawa Y. , Fujioka S. , Nagatomo H. , Shiraga H. , Mcguffey C. , Krauland C. M. , Wei M. S. , Tanaka K. A.
Published: November 2017

Experiments with a solid Cu foam (∼1.3 g/cm3) sphere coated by a 20 μm CH ablator are performed on the GEKKO-LFEX laser facility to study the effect of hot electron preheat on the implosion performance. When the target is imploded by the GEKKO lasers (∼1.2 × 1015 W/cm2 in peak intensity), plenty of hot electrons are measured through the induced Cu Kα emission, indicating that the target could suffer strong preheat. This suffering of preheat is confirmed by the temporal evolution of the target self-emission, which is well reproduced by a 2D cylindrically symmetric radiative hydrodynamic code (FLASH) when a module handling the hot electron preheat is coupled. The results given by this benchmarked code indicate that, in the typical experiments with a small (∼200 μm in diameter) solid sphere target conducted on the GEKKO-LFEX laser facility, the hot electron preheat greatly degrades the implosion performance, reducing the peak areal densities of a Cu foam sphere and a CD sphere by ∼20% and ∼35%, respectively.
Growth and wall-transpiration control of nonlinear unsteady Görtler vortices forced by free-stream vortical disturbances
Authors: Marensi Elena , Ricco Pierre
Published: November 2017

The generation, nonlinear evolution, and wall-transpiration control of unsteady Görtler vortices in an incompressible boundary layer over a concave plate is studied theoretically and numerically. Görtler rolls are initiated and driven by free-stream vortical perturbations of which only the low-frequency components are considered because they penetrate the most into the boundary layer. The formation and development of the disturbances are governed by the nonlinear unsteady boundary-region equations with the centrifugal force included. These equations are subject to appropriate initial and outer boundary conditions, which account for the influence of the upstream and free-stream forcing in a rigorous and mutually consistent manner. Numerical solutions show that the stabilizing effect on nonlinearity, which also occurs in flat-plate boundary layers, is significantly enhanced in the presence of centrifugal forces. Sufficiently downstream, the nonlinear vortices excited at different free-stream turbulence intensities Tu saturate at the same level, proving that the initial amplitude of the forcing becomes unimportant. At low Tu, the disturbance exhibits a quasi-exponential growth with the growth rate being intensified for more curved plates and for lower frequencies. At higher Tu, in the typical range of turbomachinery applications, the Görtler vortices do not undergo a modal stage as nonlinearity saturates rapidly, and the wall curvature does not affect the boundary-layer response. Good quantitative agreement with data from direct numerical simulations and experiments is obtained. Steady spanwise-uniform and spanwise-modulated zero-mass-flow-rate wall transpiration is shown to attenuate the growth of the Görtler vortices significantly. A novel modified version of the Fukagata-Iwamoto-Kasagi identity, used for the first time to study a transitional flow, reveals which terms in the streamwise momentum balance are mostly affected by the wall transpiration, thus offering insight into the increased nonlinear growth of the wall-shear stress.
An efficient X-band relativistic backward wave oscillator combining single-mode structure with overmoded structure
Authors: Xiao Renzhen , Song Zhimin , Li Xiaoze
Published: November 2017

A combined modes operation mechanism in a sectioned relativistic backward wave oscillator (RBWO) is presented. The RBWO consists of single-mode slow wave structure (SWS) and overmoded SWS. In the single-mode SWS, the electron beam interacts with TM01 mode synchronously; in the overmoded SWS, the operation mode is mainly TM02 mode. The microwave frequency is determined by the single-mode SWS, which alleviates the mode competition in the overmoded SWS. Moreover, the power capacity of the RBWO can be improved due to the employment of overmoded structure and TM02 mode operation. Particle-in-cell simulation results demonstrate that a microwave with a power of 2.5 GW and a frequency of 9.18 GHz is generated with a 680 kV, 7.3 kA electron beam, corresponding to a beam-wave power conversion efficiency of 50%.
Investigation of phase evolution and control over phase transformation temperature and thermal hysteresis using stoichiometry and co-doping in VO2 thin films
Authors: Jaffari G. Hassnain , Mahmood Wardah
Published: November 2017

Structural phase transition temperature and its associated hysteresis in VO2 have been controlled by high valent dopant induced local structural modification which acts as phase nucleation site during phase transformation. Monoclinic phase intensity loops plotted against temperature has been observed to exhibit thermal hysteresis. It is shown that the size, shape and central position of hysteresis loop depend on stoichiometry and doping concentration. Highest reduction in phase transformation temperature and thermal hysteresis width has been observed in case of W+6-Mo+6 co-doping and W+6 doping, respectively. Hence energy barrier associated with the structural phase transition has been successfully manipulated to vary Tc and hysteresis width. These findings have implications for designing the phase switching devices and smart window applications.
High-gain monolithic 3D CMOS inverter using layered semiconductors
Authors: Sachid Angada B. , Desai Sujay B. , Javey Ali , Hu Chenming
Published: November 2017

We experimentally demonstrate a monolithic 3D integrated complementary metal oxide semiconductor (CMOS) inverter using layered transition metal dichalcogenide semiconductor N-channel (NMOS) and P-channel (PMOS) MOSFETs, which are sequentially integrated on two levels. The two devices share a common gate. Molybdenum disulphide and tungsten diselenide are used as channel materials for NMOS and PMOS, respectively, with an ON-to-OFF current ratio (ION/IOFF) greater than 106 and electron and hole mobilities of 37 and 236 cm2/Vs, respectively. The voltage gain of the monolithic 3D inverter is about 45 V/V at a supply voltage of 1.5 V and a gate length of 1 μm. This is the highest reported gain at the smallest gate length and the lowest supply voltage for any 3D integrated CMOS inverter using any layered semiconductor.
Phase noise measurements with a cryogenic power-splitter to minimize the cross-spectral collapse effect
Authors: Hati Archita , Nelson Craig W. , Pappas David P. , Howe David A.
Published: November 2017

The cross-spectrum noise measurement technique enables enhanced resolution of spectral measurements. However, it has disadvantages, namely, increased complexity, inability of making real-time measurements, and bias due to the “cross-spectral collapse” (CSC) effect. The CSC can occur when the spectral density of a random process under investigation approaches the thermal noise of the power splitter. This effect can severely bias results due to a differential measurement between the investigated noise and the anti-correlated (phase-inverted) noise of the power splitter. In this paper, we report an accurate measurement of the phase noise of a thermally limited electronic oscillator operating at room temperature (300 K) without significant CSC bias. We mitigated the problem by cooling the power splitter to liquid helium temperature (4 K). We quantify errors of greater than 1 dB that occur when the thermal noise of the oscillator at room temperature is measured with the power splitter at temperatures above 77 K.
High-efficiency and low-loss gallium nitride dielectric metasurfaces for nanophotonics at visible wavelengths
Authors: Emani Naresh Kumar , Khaidarov Egor , Paniagua-Domínguez Ramón , Fu Yuan Hsing , Valuckas Vytautas , Lu Shunpeng , Zhang Xueliang , Tan Swee Tiam , Demir Hilmi Volkan , Kuznetsov Arseniy I.
Published: November 2017

The dielectric nanophotonics research community is currently exploring transparent material platforms (e.g., TiO2, Si3N4, and GaP) to realize compact high efficiency optical devices at visible wavelengths. Efficient visible-light operation is key to integrating atomic quantum systems for future quantum computing. Gallium nitride (GaN), a III-V semiconductor which is highly transparent at visible wavelengths, is a promising material choice for active, nonlinear, and quantum nanophotonic applications. Here, we present the design and experimental realization of high efficiency beam deflecting and polarization beam splitting metasurfaces consisting of GaN nanostructures etched on the GaN epitaxial substrate itself. We demonstrate a polarization insensitive beam deflecting metasurface with 64% and 90% absolute and relative efficiencies. Further, a polarization beam splitter with an extinction ratio of 8.6/1 (6.2/1) and a transmission of 73% (67%) for p-polarization (s-polarization) is implemented to demonstrate the broad functionality that can be realized on this platform. The metasurfaces in our work exhibit a broadband response in the blue wavelength range of 430–470 nm. This nanophotonic platform of GaN shows the way to off- and on-chip nonlinear and quantum photonic devices working efficiently at blue emission wavelengths common to many atomic quantum emitters such as Ca+ and Sr+ ions.
Low-power optical technique using semiconductors modulates terahertz radiation
Authors: Liebendorfer Adam
Published: November 2017

Exploiting impurities in a gallium arsenide crystal, a new approach allows for modifying waveforms of difficult-to-control terahertz radiation without bulky macroscopic modulators.
Hydraulic fracturing near domestic groundwater wells
Authors: Jasechko Scott , Perrone Debra
Published: November 2017

Significance

Millions of Americans rely on self-supply groundwater wells for drinking water, but the number of these wells that are located near hydraulic fracturing operations is unknown. Here, we show that approximately half of all hydraulically fractured wells stimulated in 2014 exist within 2–3 km of one or more domestic (public and self-supply) groundwater wells. Our finding that many hydraulically fractured and domestic groundwater wells are colocated emphasizes that determining how frequently hydraulic fracturing activities impact groundwater quality is important to maintaining high-quality water in many domestic wells.
Causes of ice age intensification across the Mid-Pleistocene Transition
Authors: Chalk Thomas B. , Hain Mathis P. , Foster Gavin L. , Rohling Eelco J. , Sexton Philip F. , Badger Marcus P. S. , Cherry Soraya G. , Hasenfratz Adam P. , Haug Gerald H. , Jaccard Samuel L. , Martínez-García Alfredo , Pälike Heiko , Pancost Richard D. , Wilson Paul A.
Published: November 2017

Significance

Conflicting sets of hypotheses highlight either the role of ice sheets or atmospheric carbon dioxide (CO
2
) in causing the increase in duration and severity of ice age cycles ∼1 Mya during the Mid-Pleistocene Transition (MPT). We document early MPT CO
2
cycles that were smaller than during recent ice age cycles. Using model simulations, we attribute this to post-MPT increase in glacial-stage dustiness and its effect on Southern Ocean productivity. Detailed analysis reveals the importance of CO
2
climate forcing as a powerful positive feedback that magnified MPT climate change originally triggered by a change in ice sheet dynamics. These findings offer insights into the close coupling of climate, oceans, and ice sheets within the Earth System.
Broad detection of bacterial type III secretion system and flagellin proteins by the human NAIP/NLRC4 inflammasome
Authors: Reyes Ruiz Valeria M. , Ramirez Jasmine , Naseer Nawar , Palacio Nicole M. , Siddarthan Ingharan J. , Yan Brian M. , Boyer Mark A. , Pensinger Daniel A. , Sauer John-Demian , Shin Sunny
Published: November 2017

Significance

Inflammasomes are cytosolic multiprotein complexes that initiate innate immune responses to microbial infection. Inflammasome specificity is determined by cytosolic innate immune sensors, including nucleotide-binding domain, leucine-rich repeat-containing family, apoptosis inhibitory proteins (NAIPs). In mice, which encode seven different NAIPs, individual NAIPs recognize specific components of the structurally related bacterial type III secretion system (T3SS) and flagellar apparatus. Humans encode a single functional NAIP, raising the question of whether human NAIP recognizes the same repertoire of bacterial ligands. Here, we find that, in contrast to the ligand specificity exhibited by the murine NAIPs, the single human NAIP broadly detects multiple T3SS and flagellin proteins. These findings provide a basis for understanding the mechanisms underlying human-specific innate immune responses against bacterial infection.
Membrane targeting of inhibitory Smads through palmitoylation controls TGF-β/BMP signaling
Authors: Li Wenqing , Li Weini , Zou Lihui , Ji Shanming , Li Chaoyi , Liu Kehui , Zhang Guoqiang , Sun Qinmiao , Xiao Fei , Chen Dahua
Published: November 2017

Significance

Inhibitory Smads (I-Smads) play important roles to negatively regulate TGF-β/BMP (bone morphogenetic protein) signaling, thus controlling numerous cellular and developmental processes. Recent studies have suggested that Smad7, a member of I-Smads, is overexpressed in numerous cancer types and its abundance is positively correlated to the malignancy. However, the molecular mechanism underlying action of I-Smads in cells remains poorly understood. Here we show that the
Drosophila
I-Smad, Dad, accesses the membrane via palmitoylation to target the BMP type I receptor for ubiquitination. Importantly, we show that the palmitoyltransferase dHIP14 catalyzes Dad palmitoylation and antagonizes BMP/Dpp signaling. Our findings uncover a mechanism by which I-Smad controls TGF-β/BMP signaling.
Amorphous MoS
3
as the sulfur-equivalent cathode material for room-temperature Li–S and Na–S batteries
Authors: Ye Hualin , Ma Lu , Zhou Yu , Wang Lu , Han Na , Zhao Feipeng , Deng Jun , Wu Tianpin , Li Yanguang , Lu Jun
Published: November 2017

Significance

We propose a concept of “sulfur-equivalent cathode materials,” and reason that instead of using problematic elemental sulfur, one can use sulfur-containing compounds as the alternatives with a comparable electrochemical property but free of any polysulfide generation. We demonstrate here the great potential of amorphous MoS
3
as such a sulfur-equivalent cathode material for room-temperature Li–S and Na–S batteries. More remarkably, we find that MoS
3
is fully cyclable in the carbonate electrolyte (which is known to kill conventional sulfur cathodes) under a relatively high temperature of 55 °C. MoS
3
can also be used as the cathode material of even more challenging Na–S batteries to enable an impressive performance.
Bicaudal D2 facilitates the cytoplasmic trafficking and nuclear import of HIV-1 genomes during infection
Authors: Dharan Adarsh , Opp Silvana , Abdel-Rahim Omar , Keceli Sevnur Komurlu , Imam Sabrina , Diaz-Griffero Felipe , Campbell Edward M.
Published: November 2017

Significance

Following envelope-mediated fusion, the HIV-1 viral core, which houses the viral RNA and proteins required for virus reverse transcription and integration, must traffic toward the nucleus for subsequent nuclear import of the viral genome. In this study we examined the role of BICD2, a known dynein adaptor protein, for its role during the postentry trafficking of HIV-1 virions. We show that BICD2 binds viral capsid and mediates the postentry trafficking of HIV-1. Moreover, we also show that depletion of BICD2 sensitizes the virus to detection by innate immune sensing, revealing this BICD2 is necessary for the virus to avoid detection by innate sensing mechanisms in macrophages.
Coupled European and Greenland last glacial dust activity driven by North Atlantic climate
Authors: Újvári Gábor , Stevens Thomas , Molnár Mihály , Demény Attila , Lambert Fabrice , Varga György , Jull A. J. Timothy , Páll-Gergely Barna , Buylaert Jan-Pieter , Kovács János
Published: November 2017

Significance

Atmospheric dust is a major component of climate change. However, the relationship between glacial continental dust activity and abrupt centennial–millennial-scale climate changes of the North Atlantic is poorly known. Recent advances in high-precision radiocarbon dating of small gastropods in continental loess deposits provide an opportunity to gain unprecedented insights into dust variations and its major drivers at centennial–millennial scales from a near-source dust archive. Here, we show that Late Quaternary North Atlantic temperature and dustiness in Greenland and Europe were largely synchronous and suggest that this coupling was driven via precipitation changes and large-scale atmospheric circulation.
Storm, rogue wave, or tsunami origin for megaclast deposits in western Ireland and North Island, New Zealand?
Authors: Dewey John F. , Ryan Paul D.
Published: November 2017

Significance

The origin of boulderite deposits in the geological record is controversial. Many argue that boulders weighing over 30 tonnes characterize tsunamites. We compare and contrast two such deposits with boulders exceeding this weight: a tsunamite from the Miocene of New Zealand and a present-day boulderite at Annagh Head, western Ireland. Combining field, historical, and oceanographic data, we argue that the latter is a cliff-top storm deposit (CTSD). Numerical modeling shows that the weight of a boulder in such CTSDs does not just reflect storm wave height, which can be over 60 m in western Ireland, but is also a function of its shape. We review the characteristics that distinguish these two deposits.
Smek1/2 is a nuclear chaperone and cofactor for cleaved Wnt receptor Ryk, regulating cortical neurogenesis
Authors: Chang Wen-Hsuan , Choi Si Ho , Moon Byoung-San , Cai Mingyang , Lyu Jungmook , Bai Jinlun , Gao Fan , Hajjali Ibrahim , Zhao Zhongfang , Campbell Daniel B. , Weiner Leslie P. , Lu Wange
Published: November 2017

Significance

Receptor-like tyrosine kinase (Ryk) is a Wnt receptor and is important for many developmental processes, including cranial facial development, neurogenesis, and axon guidance. However, little is known about the role of the intracellular domain, Ryk-ICD, in signal transduction. Its downstream targets are also unknown. We have previously shown that Ryk-ICD is located in the cytoplasm of neural stem cells whereas it moves into the nucleus upon neuronal differentiation. In this study, we discovered that Smek1/2 function as a chaperone for Ryk-ICD during its nuclear localization and that both Smek and Ryk-ICD associate with chromatin to regulate the transcription of downstream target genes and neural differentiation.
Synaptic homeostasis requires the membrane-proximal carboxy tail of GluA2
Authors: Ancona Esselmann Samantha G. , Díaz-Alonso Javier , Levy Jonathan M. , Bemben Michael A. , Nicoll Roger A.
Published: November 2017

Significance

AMPA-type glutamate receptors are known to play critical roles in both basal synaptic transmission and acute forms of plasticity, such as long-term potentiation and long-term depression, but less is known about their role in neuronal homeostasis. A model for bidirectional synaptic scaling is emerging in which the GluA2 AMPA receptor subunit has a central role. Here we confirm that GluA2, but not GluA1, is necessary for scaling, and we show that GluA2 is also sufficient for mediating this phenomenon. In addition, we find that the membrane-proximal C-terminal domain of GluA2 is required for scaling following chronic pharmacologic silencing of network activity. How the GluA2 membrane-proximal C-terminal domain mediates synaptic insertion of AMPA receptors following chronic silencing remains to be elucidated.
AP-4 mediates export of ATG9A from thetrans-Golgi network to promote autophagosome formation
Authors: Mattera Rafael , Park Sang Yoon , De Pace Raffaella , Guardia Carlos M. , Bonifacino Juan S.
Published: November 2017

Significance

A family of adaptor protein (AP) complexes functions to sort transmembrane cargos at different stages of the endomembrane system of eukaryotic cells. AP-4 is one of the most recently described and least well-understood members of this family. Interest in this complex has risen because mutations in any of its four subunits cause a form of hereditary spastic paraplegia (HSP) with intellectual disability. In this study, we demonstrate that AP-4 sorts ATG9A, the only transmembrane component of the core autophagy machinery, from thetrans-Golgi network to peripheral compartments. This sorting is required to promote the early steps of autophagosome formation. Our observations implicate AP-4 as an autophagy regulator and altered autophagy as an underlying defect in AP-4–deficient HSP.