bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetism as indirect tool for carbon content assessment in nickel nanoparticles
Authors: Oumellal Y. , Magnin Y. , Martínez de Yuso A. , Aguiar Hualde J. M. , Amara H. , Paul-Boncour V. , Matei Ghimbeu C. , Malouche A. , Bichara C. , Pellenq R. , Zlotea C.
Published: December 2017

We report a combined experimental and theoretical study to ascertain carbon solubility in nickel nanoparticles embedded into a carbon matrix via the one-pot method. This original approach is based on the experimental characterization of the magnetic properties of Ni at room temperature and Monte Carlo simulations used to calculate the magnetization as a function of C content in Ni nanoparticles. Other commonly used experimental methods fail to accurately determine the chemical analysis of these types of nanoparticles. Thus, we could assess the C content within Ni nanoparticles and it decreases from 8 to around 4 at. % with increasing temperature during the synthesis. This behavior could be related to the catalytic transformation of dissolved C in the Ni particles into graphite layers surrounding the particles at high temperature. The proposed approach is original and easy to implement experimentally since only magnetization measurements at room temperature are needed. Moreover, it can be extended to other types of magnetic nanoparticles dissolving carbon.
Enhanced texture evolution and piezoelectric properties in CuO-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 grain-oriented ceramics
Authors: Chang Yunfei , Watson Beecher , Fanton Mark , Meyer Richard J. , Messing Gary L.
Published: December 2017

In this work, both crystallographic texture and doping engineering strategies were integrated to develop relaxor-PbTiO3 (PT) based ternary ferroelectric ceramics with enhanced texture evolution and superior electromechanical properties. CuO-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) piezoelectric ceramics with [001]c texture fraction ≥97% were synthesized by templated grain growth. The addition of CuO significantly promotes densification and oriented grain growth in the templated ceramics, leading to full texture development at dramatically reduced times and temperatures. Moreover, the CuO dopant remarkably enhances the piezoelectric properties of the textured ceramics while maintaining high phase transition temperatures and large coercive fields. Doping 0.125 wt. % CuO yields the electromechanical properties of d33 = 927 pC/N, d33* = 1510 pm/V, g33 = 43.2 × 10−3 Vm/N, Kp = 0.87, Ec=8.8 kV/cm, and tan δ = 1.3%, which are the best values reported so far in PIN-PMN-PT based ceramics. The high piezoelectric coefficient is mainly from the reversible piezoelectric response, with the irreversible contribution being on the order of 13.1%. We believe that this work not only facilitates closing the performance gap between ceramics and single crystals but also can expand relaxor-PT based piezoelectric application fields.
Photonic-band-gap gyrotron amplifier with picosecond pulses
Authors: Nanni Emilio A. , Jawla Sudheer , Lewis Samantha M. , Shapiro Michael A. , Temkin Richard J.
Published: December 2017

We report the amplification of 250 GHz pulses as short as 260 ps without observation of pulse broadening using a photonic-band-gap circuit gyrotron traveling-wave-amplifier. The gyrotron amplifier operates with a device gain of 38 dB and an instantaneous bandwidth of 8 GHz. The operational bandwidth of the amplifier can be tuned over 16 GHz by adjusting the operating voltage of the electron beam and the magnetic field. The amplifier uses a 30 cm long photonic-band-gap interaction circuit to confine the desired TE03-like operating mode while suppressing lower order modes which can result in undesired oscillations. The circuit gain is >55 dB for a beam voltage of 23 kV and a current of 700 mA. These results demonstrate the wide bandwidths and a high gain achievable with gyrotron amplifiers. The amplification of picosecond pulses of variable lengths, 260–800 ps, shows good agreement with the theory using the coupled dispersion relation and the gain-spectrum of the amplifier as measured with quasi-CW input pulses.
S-band microwave radiation by a high-impedance diode with an A6 anode block
Authors: Sayapin A. , Dai U. , Krasik Ya. E.
Published: December 2017

The results of experimental research of the intensity distribution of microwave fields in the resonant cavities of an A6 anode block with a high-impedance (≥120 Ω) magnetically insulated electron diode powered by a Linear Induction Accelerator (LIA) (∼350 kV, ∼2.5 kA, 150 ns) are presented. The power and duration of the microwave pulses obtained from one cavity varied in the range of 200–300 MW and 120–50 ns, respectively, depending on the charging voltage of the LIA and the value of the axial magnetic field. It was found that the field intensity in cavities adjacent to the extraction cavity differs by ∼3 times and that the field intensity gradually increases along the series of cavities. The direction of this increase coincides with the direction of the electrons' E×B drift, i.e., the change in the magnetic field direction results in the change in the direction of the increase in the intensity of the field in the cavities.
Electronic field emission models beyond the Fowler-Nordheim one
Authors: Lepetit Bruno
Published: December 2017

We propose several quantum mechanical models to describe electronic field emission from first principles. These models allow us to correlate quantitatively the electronic emission current with the electrode surface details at the atomic scale. They all rely on electronic potential energy surfaces obtained from three dimensional density functional theory calculations. They differ by the various quantum mechanical methods (exact or perturbative, time dependent or time independent), which are used to describe tunneling through the electronic potential energy barrier. Comparison of these models between them and with the standard Fowler-Nordheim one in the context of one dimensional tunneling allows us to assess the impact on the accuracy of the computed current of the approximations made in each model. Among these methods, the time dependent perturbative one provides a well-balanced trade-off between accuracy and computational cost.
Joint effect of gate bias and light illumination on metallic LaAlO3/SrTiO3 interface
Authors: Yang Zhihuan , Chen Yuansha , Zhang Hongrui , Huang Hailin , Wang Shufang , Wang Shuanhu , Shen Baogen , Sun Jirong
Published: December 2017

We presented a systemic investigation on the joint effect of gate bias and light illumination on a metallic LaAlO3/SrTiO3 interface in the temperature range from 15 K to 300 K. We showed that the photo excitation significantly enhanced the gating effect for the metallic two-dimensional electron gas. However, its effect is strongly temperature dependent; it is strong at low and high temperatures, and weak in the intermediate temperature range. There are evidences that the amplified gating effect stemmed from enhanced carrier depletion while the Hall mobility remains nearly unaffected. Acceleration of the gating process, together with a training effect marked by a strong dependence on gating history of the getting effect, is induced by repeating the electric cycling, indicating atomic reconfiguration due to oxygen migration and the memory of the migration paths.
Sex-specific differences in growth, mortality and migration support population resilience in the heavily exploited migratory marine teleost Mugil cephalus (Linnaeus 1758)
Authors: Stewart John , Hegarty Anne-Marie , Young Caitlin , Fowler Ashley M.
Published: December 2017

Understanding mechanisms supporting the resilience of exploited fish populations is fundamental to sustainable management. Herein we identify sex-specific differences in life history traits that confer resilience in the heavily exploited population of Mugil cephalus along eastern Australia. M. cephalus in this region emigrate from estuaries and undergo an annual northerly spawning migration that is dominated by males. Males mature, on average, at younger ages than females and were most abundant in the spawning migration at age-4, whereas females were most abundant at age-5. Females grew significantly faster and larger than males, with both sexes being aged up to 14 years. These sex-specific differences relate directly to the population stability of M. cephalus under the reproductive strategy of a spawning migration. Males participate in the spawning migration at younger ages and in greater numbers than females to ensure a sufficient number of males for successful spawning. Females partition more energy to growth than males, maturing and participating in the spawning migration at older ages and larger sizes. The larger body size of females is related to increased fecundity, increased survivorship and more efficient swimming ability. These traits, combined with population strategies of both delayed and skipped spawning, convey substantial resilience.
Living on the edge: characteristics of human–wildlife conflict in a traditional livestock community in Botswana
Authors: McNutt J. Weldon , Stein Andrew B. , McNutt Lesley Boggs , Jordan Neil R.
Published: December 2017

Context
Conflicts between wildlife and humans have occurred for millennia, and are major drivers of wildlife decline. To promote coexistence, Botswana established buffer zones called wildlife-management areas (WMAs) adjacent to National Parks and Reserves where communities assume stewardship of wildlife and derive financial benefits from it. In contrast, communities outside WMAs are generally excluded from these benefits despite incurring ‘coexistence costs’, including crop damage and livestock depredation, although they may receive compensation for these losses.

Aims
To investigate the perceptions and actions of a livestock farming community outside (but surrounded by) WMAs in northern Botswana, especially in relation to predator management.

Methods
We conducted standard-format interviews with 62 heads of households (cattleposts), and evaluated responses using descriptive and multivariate statistics.

Key results
Almost half (46%) of respondents expressed negative perceptions of predators, with 67% reporting losses to predation. After disease, predation was the most commonly reported source of livestock losses. Increased age of the head of household was the strongest predictor of reported predation. Few households employed husbandry beyond kraaling at night, but some (21%) reported conducting lethal control of predators. Reported use of lethal control was independent of the household experience with predation and whether they derived financial benefits from wildlife. Instead, households with larger herds were more likely to report using lethal control, despite the most educated farmers tending to have larger herds. Lethal control was almost twice as likely in households previously denied government compensation for losses (42%) than in those granted compensation (23%). Perhaps as a result of perceived failures of the government compensation scheme, most households (91%) supported the development of an independent insurance program, with 67% expressing willingness to pay a premium.

Conclusions
Our results challenge the assumption that deriving financial benefit from wildlife increases tolerance. A measurable disconnect also exists between the willingness of a household to employ lethal control and their experience with predation, suggesting that lethal control was used pre-emptively rather than reactively.

Implications
Efforts must be made to connect the financial costs incurred during farming alongside wildlife with the financial benefits derived from wildlife. Where compensation schemes exist, timely payments may reduce retaliatory killing.
Transverse fields to tune an Ising-nematic quantum phase transition
Authors: Maharaj Akash V. , Rosenberg Elliott W. , Hristov Alexander T. , Berg Erez , Fernandes Rafael M. , Fisher Ian R. , Kivelson Steven A.
Published: December 2017

Significance

Many interesting materials, including various high-temperature superconductors, exhibit a low-temperature “electron nematic” phase in which the electronic properties spontaneously break the rotational symmetry of the crystal. A nematic quantum critical point (QCP) marks the zero-temperature phase transition from a nematic ground state to a symmetric state as a function of a macroscopic nonthermal parameter. Here, we examine appropriate general means to tune Ising nematic systems to a QCP and in particular show that shear strain is a powerful tuning parameter. Moreover, we identify 4f ferroquadrupolar order as a realization of Ising nematic order and argue that it provides a promising platform for fundamental studies of metallic QCPs in the laboratory.
Effects of Al–8.5Si–25Cu–xY filler metal foils on vacuum brazing of SiCp/Al composites
Authors: Yu Yueyue , Xu Dongxia , Tian Jinfeng , Wang Dongbin , Wang Peng , Niu Jitai
Published: December 2017

Rapidly solidified Al–8.5Si–25Cu– xY (wt-%, x = 0, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5) foils were used as filler metal to braze Al matrix composites with high SiC particle content (SiCp/Al-MMCs), and the filler presented fine microstructure and good wettability on the composites. The joint shear strength first increased, then decreased and a sound joint with a maximum shear strength of 135.32 MPa was achieved using Al–8.5Si–25Cu–0.3Y as the filler metal. After Y exceeded 0.3%, a needle-like intermetallic compound, Al3Y, was found in the brazing seam, resulting in a dramatic decline in the shear strength of the brazed joints. In this research, the Al–8.5Si–25Cu–0.3Y filler metal foil was found to be suitable for the brazing of SiCp/Al-MMCs with high SiC particle content.
Enhancement of mechanical properties of low carbon steel joints via graphene addition
Authors: Jafarlou H. , Hassannezhad K. , Asgharzadeh H. , Marami G. R.
Published: December 2017

Steel base metal laps or welding electrode surfaces were coated using graphene suspensions with various concentrations, and then the steel plates were welded using the shielded metal arc welding process. Microstructural observations showed that the addition of graphene to the weldment significantly refines the microstructure and promotes the formation of fine acicular ferrite. The results of mechanical testing indicated that with lower concentrations of graphene in the weldment, both the strength and ductility improve, but the hardness remains unchanged in comparison to the unreinforced weld metal. However, reinforcing with a higher concentration of graphene gives rise to the significant enhancement of the hardness and strength without deterioration of the ductility.
Influence of cryogenic thermal treatment on mechanical properties of an Al–Cu–Mg alloy
Authors: Araghchi M. , Mansouri H. , Vafaei R.
Published: December 2017

In this study, a cryogenic thermal treatment is developed and its effects on mechanical properties and precipitates are investigated. Water-quenched samples were immersed in liquid nitrogen and reheated in hot oil at 180°C or boiling water for 5 min. Finally, the samples were artificially aged at 190°C for 12 h. The results indicated a notable increase of about 75 MPa in the ultimate tensile strength in comparison to T6 heat-treated alloy. TEM observations revealed that the S(S′) precipitates were fine and uniformly distributed in the microstructure due to reheating in hot oil and subsequent aging treatment.
Black hole entropy in massive Type IIA
Authors: Benini Francesco , Khachatryan Hrachya , Milan Elisa
Published: December 2017

We study the entropy of static dyonic BPS black holes in AdS4 in 4d

N

=
2

gauged supergravities with vector and hyper multiplets, and how the entropy can be reproduced with a microscopic counting of states in the AdS/CFT dual field theory. We focus on the particular example of BPS black holes in AdS

4

×

S
6

in massive Type IIA, whose dual three-dimensional boundary description is known and simple. To count the states in field theory we employ a supersymmetric topologically twisted index, which can be computed exactly with localization techniques. We find a perfect match at leading order.
High-cycle electromechanical aging of dielectric elastomer actuators with carbon-based electrodes
Authors: de Saint-Aubin C A , Rosset S , Schlatter S , Shea H
Published: December 2017

We present high-cycle aging tests of dielectric elastomer actuators (DEAs) based on silicone elastomers, reporting on the time-evolution of actuation strain and of electrode resistance over millions of cycles. We compare several types of carbon-based electrodes, and for the first time show how the choice of electrode has a dramatic influence on DEA aging. An expanding circle DEA configuration is used, consisting of a commercial silicone membrane with the following electrodes: commercial carbon grease applied manually, solvent-diluted carbon grease applied by stamping (pad printing), loose carbon black powder applied manually, carbon black powder suspension applied by inkjet-printing, and conductive silicone-carbon composite applied by stamping. The silicone-based DEAs with manually applied carbon grease electrodes show the shortest lifetime of less than 105 cycles at 5% strain, while the inkjet-printed carbon powder and the stamped silicone-carbon composite make for the most reliable devices, with lifetimes greater than 107 cycles at 5% strain. These results are valid for the specific dielectric and electrode configurations that were tested: using other dielectrics or electrode formulations would lead to different lifetimes and failure modes. We find that aging (as seen in the change in resistance and in actuation strain versus cycle number) is independent of the actuation frequency from 10 Hz to 200 Hz, and depends on the total accumulated time the DEA spends in an actuated state.
Linear synchronization and circuit implementation of chaotic system with complete amplitude control*
Authors: Li Chun-Biao , Thio Wesley Joo-Chen , Sprott Julien Clinton , Zhang Ruo-Xun , Lu Tian-Ai
Published: December 2017

Although chaotic signals are considered to have great potential applications in radar and communication engineering, their broadband spectrum makes it difficult to design an applicable amplifier or an attenuator for amplitude conditioning. Moreover, the transformation between a unipolar signal and a bipolar signal is often required. In this paper, a more intelligent hardware implementation based on field programmable analog array (FPAA) is constructed for chaotic systems with complete amplitude control. Firstly, two chaotic systems with complete amplitude control are introduced, one of which has the property of offset boosting with total amplitude control, while the other has offset boosting and a parameter for partial control. Both cases can achieve complete amplitude control including amplitude rescaling and offset boosting. Secondly, linear synchronization is established based on the special structure of chaotic system. Finally, experimental circuits are constructed on an FPAA where the predicted amplitude control is realized through only two independent configurable analog module (CAM) gain values.
Temporal variability in offspring quality and individual reproductive output in a broadcast-spawning marine fish
Authors: Roney Nancy E , Oomen Rebekah A , Knutsen Halvor , Olsen Esben M , Hutchings Jeffrey A
Published: December 2017

The protracted spawning period of broadcast-spawning marine fishes has potential to generate considerable variability in metrics of individual reproductive output. We undertook a temporally detailed genetic study of larvae produced by Atlantic cod (Gadus morhua) from two spatially proximate populations spawning under controlled semi-natural conditions over 94 days. Based on daily samples of larvae (n = 4489 in total), we document fine-scaled temporal changes in, and correlates of, offspring phenotype and reproductive output (egg batches produced or fertilized). Larval length and standardized yolk-sac volume declined 11 and 49% over the spawning period, respectively. The adaptive significance of these trends is unclear. Longer, heavier females produced longer, better-provisioned larvae. Body size affected the number of egg batches to which an individual contributed genetically but not spawning duration. Males contributed gametes to a greater number of egg batches (19.5 vs. 9.2), and spawned over a longer period of time (48.9 vs. 30.8 days), than females. After accounting for body size and condition, egg batch number and spawning duration differed between adjacent populations separated by < 10 km. Our work highlights the need to understand the environmental and adaptive causes of temporal variability in offspring quality and its consequences to individual fitness and per capita population growth in batch-spawning fishes.
Tolerability profile of the current antifungal armoury
Authors: Mourad Ahmad , Perfect John R
Published: December 2017

The tolerability of available antifungal agents is essential to the final outcome of the management of invasive mycoses. There are limited classes of antifungal agents for use, and they can have serious direct toxicities and/or drug–drug interactions. In this review, we examine the common toxicities noted for antifungal agents and attempt to both identify the issues around the adverse events and provide clinical context for their occurrence in these fragile patients.
Human Amniotic Membrane for the Prevention of Intradural Spinal Cord Adhesions: Retrospective Review of its Novel Use in a Case Series of 14 Patients
Authors: Walker Corey T , Godzik Jakub , Kakarla U Kumar , Turner Jay D , Whiting Alexander C , Nakaji Peter
Published: December 2017

BACKGROUND

Tethering after spinal surgery is caused by adhesions that arise from intradural tissue manipulation. Microsurgical detethering is the only treatment for symptomatic patients, but retethering occurs commonly and no treatment is widely available to prevent this complication.

OBJECTIVE

To apply human amniotic membrane (HAM) grafts, which are immune-privileged and known to possess antifibrogenic properties, in patients requiring microsurgical detethering. For this first-in-human use, we evaluated the safety and potential efficacy of these grafts for preventing retethering.

METHODS

We retrospectively reviewed the medical records of all patients who required detethering surgery and received an HAM graft between 2013 and 2016 at our institution after various previous intradural spinal surgeries. In all 14 cases, intradural lysis of adhesions was achieved, an HAM graft was sewn in place intradurally, and a dural patch was closed in a watertight fashion over the graft.

RESULTS

Fourteen patients had received HAM grafts to prevent retethering. All patients had at least 6 mo of follow-up (mean follow-up, 14 mo). Retethering was noted in only 1 patient. Surgical re-exploration showed that the retethering occurred caudal to the edge of the HAM graft, with no tethering underneath the original graft. No complications were attributed specifically to the HAM graft placement.

CONCLUSION

This first-in-human series provides evidence that HAM grafts are a safe and potentially efficacious method for preventing retethering after microsurgical intradural lysis of adhesions. These results lay the groundwork for further prospective controlled trials in patients with this difficult-to-treat pathology.
Organophosphorus Compounds at 80: Some Old and New Issues
Authors: Costa Lucio G
Published: December 2017

One of the major classes of pesticides is that of the organophosphates (OPs). Initial developments date back almost 2 centuries but it was only in the mid-1940s that OPs reached a prominent status as insecticides, a status that, albeit declining, is still ongoing. OPs are highly toxic to nontarget species including humans, the primary effects being an acute cholinergic toxicity (responsible for thousands of poisoning each year) and a delayed polyneuropathy. Several issues of current debate and investigation on the toxicology of OPs are discussed in this brief review. These include (1) possible additional targets of OPs, (2) OPs as developmental neurotoxicants, (3) OPs and neurodegenerative diseases, (4) OPs and the “aerotoxic syndrome,” (5) OPs and the microbiome, and (6) OPs and cancer. Some of these issues have been debated and studied for some time, while others are newer, suggesting that the study of the toxicology of OPs will remain an important scientific and public health issue for years to come.
Microvascular Permeability after an Acute and Chronic Salt Load in Healthy Subjects
Authors: Rorije Nienke M. G. , Olde Engberink Rik H. G. , Chahid Youssef , van Vlies Naomi , van Straalen Jan P. , van den Born Bert-Jan H. , Verberne Hein J. , Vogt Liffert
Published: December 2017

Background

Sodium-induced microcirculatory changes, endothelial surface layer alterations in particular, may play an important role in sodium-mediated blood pressure elevation. However, effects of acute and chronic sodium loading on the endothelial surface layer and microcirculation in humans have not been established. The objective of this study was to assess sodium-induced changes in blood pressure and body weight as primary outcomes and also in microvascular permeability, sublingual microcirculatory dimensions, and urinary glycosaminoglycan excretion in healthy subjects.

Methods

Twelve normotensive males followed both a low-sodium diet (less than 50 mmol/day) and a high-sodium diet (more than 200 mmol/day) for eight days in randomized order, separated by a crossover period. After the low-sodium diet, hypertonic saline (5 mmol sodium/liter body water) was administered intravenously in 30 min.

Results

Both sodium interventions did not change blood pressure. Body weight increased with 2.5 (95% CI, 1.7 to 3.2) kg (P < 0.001) after dietary sodium loading. Acute intravenous sodium loading resulted in increased transcapillary escape rate of 125I-labeled albumin (2.7 [0.1 to 5.3] % cpm · g−1 · h–1; P = 0.04), whereas chronic dietary sodium loading did not affect transcapillary escape rate of 125I-labeled albumin (−0.03 [−3.3 to 3.2] % cpm · g−1 · h–1; P = 1.00), despite similar increases of plasma sodium and osmolality. Acute intravenous sodium loading coincided with significantly increased plasma volume, as assessed by the distribution volume of albumin, and significantly decreased urinary excretion of heparan sulfate and chondroitin sulfate. These changes were not observed after dietary sodium loading.

Conclusions

Our results suggest that intravenous sodium loading has direct adverse effects on the endothelial surface layer, independent of blood pressure.
Physiologic Evaluation of Ventilation Perfusion Mismatch and Respiratory Mechanics at Different Positive End-expiratory Pressure in Patients Undergoing Protective One-lung Ventilation
Authors: Spadaro Savino , Grasso Salvatore , Karbing Dan Stieper , Fogagnolo Alberto , Contoli Marco , Bollini Giacomo , Ragazzi Riccardo , Cinnella Gilda , Verri Marco , Cavallesco Narciso Giorgio , Rees Stephen Edward , Volta Carlo Alberto
Published: December 2017

Background

Arterial oxygenation is often impaired during one-lung ventilation, due to both pulmonary shunt and atelectasis. The use of low tidal volume (VT) (5 ml/kg predicted body weight) in the context of a lung-protective approach exacerbates atelectasis. This study sought to determine the combined physiologic effects of positive end-expiratory pressure and low VT during one-lung ventilation.

Methods

Data from 41 patients studied during general anesthesia for thoracic surgery were collected and analyzed. Shunt fraction, high V/Q and respiratory mechanics were measured at positive end-expiratory pressure 0 cm H2O during bilateral lung ventilation and one-lung ventilation and, subsequently, during one-lung ventilation at 5 or 10 cm H2O of positive end-expiratory pressure. Shunt fraction and high V/Q were measured using variation of inspired oxygen fraction and measurement of respiratory gas concentration and arterial blood gas. The level of positive end-expiratory pressure was applied in random order and maintained for 15 min before measurements.

Results

During one-lung ventilation, increasing positive end-expiratory pressure from 0 cm H2O to 5 cm H2O and 10 cm H2O resulted in a shunt fraction decrease of 5% (0 to 11) and 11% (5 to 16), respectively (P < 0.001). The Pao
2/Fio2
ratio increased significantly only at a positive end-expiratory pressure of 10 cm H2O (P < 0.001). Driving pressure decreased from 16 ± 3 cm H2O at a positive end-expiratory pressure of 0 cm H2O to 12 ± 3 cm H2O at a positive end-expiratory pressure of 10 cm H2O (P < 0.001). The high V/Q ratio did not change.

Conclusions

During low VT one-lung ventilation, high positive end-expiratory pressure levels improve pulmonary function without increasing high V/Q and reduce driving pressure.
Recent developments in systemic lupus erythematosus pathogenesis and applications for therapy
Authors: Lo Mindy S. , Tsokos George C.
Published: December 2017

Purpose of review

Systemic lupus erythematosus (SLE) pathogenesis is complex. Aberrancies of immune function that previously were described but not well understood are now becoming better characterized, in part through recognition of monogenic cases of lupus-like disease.

Recent findings

We highlight here recent descriptions of metabolic dysfunction, cytokine dysregulation, signaling defects, and DNA damage pathways in SLE. Specifically, we review the effects of signaling abnormalities in mammalian target of rapamycin, Rho kinase, Bruton's tyrosine kinase, and Ras pathways. The importance of DNA damage sensing and repair pathways, and their influence on the overproduction of type I interferon in SLE are also reviewed.

Recent findings in SLE pathogenesis expand on previous understandings of broad immune dysfunction. These findings have clinical applications, as the dysregulated pathways described here can be targeted by existing and preclinical therapies.
Minimally Invasive Lateral Lumbar Interbody Fusion for Adult Spinal Deformity
Authors: Park Hyung-Youl , Ha Kee-Yong , Kim Young-Hoon , Chang Dong-Gune , Kim Sang-il , Lee Jae-Won , Ahn Joo-Hyun , Kim Jong-Bin
Published: December 2017

Study Design.

A retrospective cohort study.

Objective.

To evaluate the clinical and radiological efficacies of supplementing minimally invasive lateral lumbar interbody fusion (LLIF) with open posterior spinal fusion (PSF) in adult spinal deformity (ASD).

Summary of Background Data.

Minimally invasive techniques have been increasingly applied for surgery of ASD. Few reports have been published that directly compare LLIF combined with PSF to conventional PSF for ASD.

Methods.

To evaluate the advantages of minimally invasive LLIF for ASD, patients who underwent minimally invasive LLIF followed by open PSF (combined group) were compared with patients who only underwent PSF (only PSF group). The clinical and radiological outcomes for deformity correction and indirect decompression were assessed. The occurrence of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) were also evaluated.

Results.

No significant differences were observed in the clinical outcomes of the Oswestry Disability Index (ODI), visual analog scale, and major complications including reoperations between the groups. No additional advantage was found for coronal deformity correction, but the restoration of lumbar lordosis in the combined group was significantly higher postoperatively (15.3° vs. 8.87°, P = 0.003) and last follow-up (6.69° vs. 1.02°, P = 0.029) compared to that of the only PSF group. In the subgroup analysis for indirect decompression for the combined group, a significant increase of canal area (104 vs. 122 mm2) and foraminal height (16.2 vs. 18.5 mm) was noted. The occurrence of PJK or PJF was significantly higher in the combined group than in the only PSF group (P = 0.039).

Conclusion.

LLIF has advantages of indirect decompression and greater improvements of sagittal correction compared to only posterior surgery. LLIF should be conducted considering the above-mentioned benefits and complications including PJK or PJF in ASD.

Level of Evidence: 4
Functional Limitations Due to Stiffness After Long-Level Spinal Instrumented Fusion Surgery to Correct Lumbar Degenerative Flat Back
Authors: Choi Jeong-Hoon , Jang Jee-Soo , Yoo Kyong-Suk , Shin Jong-Mog , Jang Il-Tae
Published: December 2017

Study Design.

A retrospective analysis of functional limitations due to stiffness after long-level spinal instrumented fusion surgery to correct lumbar degenerative flat back was performed.

Objective.

To analysis the functional limitations in patients treated surgically for adult lumbar degenerative flat back (ALDFB) with long-level instrumented fusion to the sacrum or pelvis.

Summary of Background Data.

Long-level instrumented fusion for ALDFB decreases back pain and spinal deformity. On the contrary, this surgery considerably eliminates spinal range of motion. This may have the potential to impair function and ability to perform activities of daily living (ADLs).

Methods.

Consecutive 44 patients who underwent long-level instrumented fusion to the sacrum or pelvis for ALDFB were retrospectively included in this study. All patients were followed up for a minimum of 13 months. The Lumbar Stiffness Disability Index for Korean Lifestyle and Oswestry Disability Index were administered and analyzed to assess the impact of spinal stiffness on daily living. Cohorts were defined based on the upper instrumented vertebrae (above T10 [group 1] or below L1 [group 2]) and lower instrumented vertebrae (S1 pedicle screw [group S] or iliac bolt screw [group I]).

Results.

All patients showed deteriorated postoperative ADLs compared to preoperative values. Group 1 showed deterioration postoperatively compared to group 2. Group 1 showed deteriorated postoperative ADLs compared to preoperative values. In group 2, question 5 and 7 showed deterioration postoperatively compared to preoperative values, and question 2 and 10 showed improvement postoperatively compared to preoperative values. Group I showed deterioration postoperatively compared to group S.

Conclusion.

This study will hopefully allow surgeons to provide patients with ALDFB with a more informed explanation of expected surgery effects on specific ADLs.

Level of Evidence: 3
Postoperative Emergency Department Utilization and Hospital Readmission After Cervical Spine Arthrodesis
Authors: Derman Peter B. , Lampe Lukas P. , Pan Ting Jung , Salzmann Stephan N. , Kueper Janina , Girardi Federico P. , Lyman Stephen , Hughes Alexander P.
Published: December 2017

Study Design.

Retrospective state database analysis.

Objective.

To quantify the 30- and 90-day emergency department (ED) utilization and inpatient readmission rates after primary cervical arthrodesis, to stratify these findings by surgical approach, and to describe risk factors and conditions precipitating these events.

Summary of Background Data.

Limited data exist on ED utilization and hospital readmission rates after cervical spine arthrodesis.

Methods.

The New York State all-payer health-care database was queried to identify all 87,045 patients who underwent primary subaxial cervical arthrodesis from 1997 through 2012. Demographic data and clinical information were extracted. Readmission data were available for the entire study period, whereas ED utilization data collection began later and was therefore analyzed starting in 2005. Incidences of these events within 30 and 90 days of discharge as well as trends over time were tabulated. The conditions prompting these encounters were also collected. Data were analyzed with respect to surgical approach.

Results.

The hospital readmission rate was 4.2% at 30 days and 6.2% at 90 days postoperatively. Approximately 6.2% of patients were managed in the ED without inpatient admission within 30 days and 11.3% within 90 days of surgery. The most common conditions prompting such events were dysphagia or dysphonia, respiratory complications, and infection. ED utilization and readmission rates were lowest after anterior surgeries. A preoperative Charlson Comorbidity Index of 1 or greater and traumatic pathologies were associated with increased risk of subsequent ED utilization or hospital readmission. Thirty-day hospital readmission rates declined after 2010, whereas 30-day ED utilization continued to increase.

Conclusion.

Patient comorbidities, traumatic pathologies, and surgical approach are associated with increased postoperative complications. Anterior procedures carry the lowest risk, followed by posterior and then circumferential. Awareness of these findings should help to encourage development of strategies to minimize the rate of postoperative ED utilization and hospital readmission.

Level of Evidence: 3
Dynamic Fluctuation of Truncal Shift Parameters During Quiet Standing in Healthy Young Individuals
Authors: Kato So , Fok Kai Lon , Lee Jae W. , Masani Kei
Published: December 2017

Study Design.

Retrospective analysis.

Objective.

To describe the dynamic fluctuation of truncal shift parameters during quiet standing in healthy young individuals using biomechanical analyses.

Summary of Background Data.

Coronal decompensation (CD) and sagittal vertical axis (SVA) are the key radiographic parameters to assess static truncal stability, with the known cut-off value of 4 cm for SVA in determining severity of spinal deformity. These values are obtained at a specific moment during quiet standing, when the posture innately changes. Thus, unassessed truncal sway could potentially compromise the reliability of these measurements.

Methods.

Previously obtained biomechanical data with 11 male, healthy participants aged 16 to 29 were used to quantify the dynamic sway of standing posture. The participants were instructed to quietly stand with surface reflective markers for 130 seconds. The midpoint of bilateral acromia was used as a surrogate for C7 vertebral body. The time series of coronal and sagittal shifts of C7 to sacrum were measured as quasi-coronal decompensation (CD) and quasi-sagittal vertical axis (SVA) to simulate CD and SVA on radiographs. A force platform was also used to measure the center of pressure (COP) displacement.

Results.

The group averages of the dynamic sway range were 20.2 ± 4.1 mm (range: 15.1–28.6) in the sagittal plane (quasi-SVA) and 9.8 ± 3.2 mm (range: 5.5–15.2) in the coronal plane (quasi-CD). There were significant correlations between quasi-CD sway and medial-lateral COP velocity (Pearson r = 0.65, P = 0.03), as well as between quasi-SVA sway and COP sway area (r = 0.65, P = 0.03).

Conclusion.

Given the considerable fluctuation of quasi-SVA and quasi-CD during quiet standing, the reliability of radiographic measurement using CD and SVA at a specific moment can be substantially compromised. The assessment based on the currently proposed cut-off values should be interpreted with caution, and repeat examinations are warranted.

Level of Evidence: 4
Can Early Patient-reported Outcomes Be Used to Identify Patients at Risk for Poor 1-Year Health Outcomes After Lumbar Laminectomy With Arthrodesis?
Authors: Purvis Taylor E. , Neuman Brian J. , Riley Lee H. , Skolasky Richard L.
Published: December 2017

Study Design.

Prospective cohort.

Objective.

Determine A) between-patient variability in patient-reported outcomes (PROs) at four postoperative time points; B) within-patient correlation of 1-year PROs with PROs at three earlier time points; and C) ability of early PROs to predict 1-year PROs after lumbar laminectomy with arthrodesis.

Summary of Background Data.

It is unclear whether early PROs can help identify patients at risk for poor health outcomes.

Methods.

Between 2015 and 2016, we assessed pre- and postoperative back pain, leg pain, disability, physical health, and mental health in 146 patients. We examined PRO variability between patients and correlations within patients during the first postoperative year. For early (≤3-mo) and 1-year PROs, we examined concordance between experiencing a minimal important difference (MID) early and at 1 year and odds of experiencing a 1-year MID given early absence of a MID.

Results.

Postoperatively, we found increasing between-patient variability of PROs. For individual patients, we found moderate to strong between-assessment correlations (intraclass correlations) between repeated PROs (back pain, 0.47; leg pain, 0.51; disability, 0.47; physical health, 0.63; mental health, 0.53). Early MIDs were experienced for back pain (57%), leg pain (52%), physical health (38%), disability (34%), and mental health (16%). Concordance was moderate for leg pain (0.48), mental health (0.46), disability (0.38), back pain (0.36), and physical health (0.25). In patients without an early MID, odds of experiencing a MID at 1 year were low for physical health (odds ratio [OR] = 0.33), back pain (OR = 0.30), leg pain (OR = 0.14), and disability (OR = 0.11) but not mental health (OR = 0.50).

Conclusion.

Although postoperative recovery is variable, early PROs can identify patients at risk for poor 1-year outcomes and may help tailor care during the first year after lumbar laminectomy with arthrodesis.

Level of Evidence: 2
Novel therapeutic strategies and targets in advanced uveal melanoma
Authors: Chua Vivian , Aplin Andrew E.
Published: December 2017

Purpose of review

Currently, there are no U.S. Food and Drug Administration-approved or effective treatment options for advanced-stage uveal melanoma. In this article, we focus on therapeutic targets in pathways/mechanisms associated with common mutations in uveal melanoma. We review the challenges associated with targeting of these pathways and novel treatment strategies.

Recent findings

Common mutations that promote uveal melanoma initiation and progression include alterations in G protein subunit alpha q/11 (GNAQ/GNA11) and breast cancer gene 1-associated protein 1 (BAP1). Mutant GNAQ/GNA11 induces constitutive activation of tumorigenic pathways such as extracellular signal-regulated kinase (ERK)1/2 and yes-associated protein. Inhibition of mitogen-activated protein kinase kinase (MEK) downstream of ERK1/2, however, was shown in trials to have limited clinical benefit. Recent reports suggested that combination therapies of MEK inhibition and modulators of mechanisms of drug resistance may improve tumor responses to MEK inhibitors. BAP1 has been shown to be involved in modulating chromatin dynamics and deubiquitination of proteins. Hence, epigenetic inhibitors are being investigated in BAP1 mutant uveal melanoma. However, other functions of BAP1, such as in DNA damage repair and cell cycle regulation, indicate additional targets for treatment of BAP1 mutant uveal melanoma. In addition, the frequent delayed development of uveal melanoma macrometastases is likely due to cellular dormancy mechanisms. Nuclear receptor subfamily 2, group F, member 1 and transforming growth factor beta 2 were among factors that have been shown in other cancers to induce dormant phenotypes.

Findings from studies in uveal melanoma and in other cancers provide evidence for potential strategies that may be tested preclinically and clinically in advanced-stage uveal melanoma to improve treatment outcome and overall survival of patients.
Patterns of Care and Outcomes of Hypofractionated Chemoradiation Versus Conventionally Fractionated Chemoradiation for Glioblastoma in the Elderly Population
Authors: Haque Waqar , Verma Vivek , Butler Edward B. , Teh Bin S.
Published: December 2017

Purpose:

This study evaluated practice patterns, outcomes, and predictors of survival for elderly patients with glioblastoma (GBM) receiving definitive chemoradiotherapy (CRT) with either hypofractionated radiotherapy or conventionally fractionated radiotherapy.

Materials and Methods:

The National Cancer Data Base was queried for patients age 65 years and above diagnosed with GBM between 2006 and 2012 that received definitive CRT with either hypofractionated radiotherapy (hCRT) or conventionally fractionated radiotherapy (cCRT). Patient, tumor, and treatment parameters were extracted. Statistics included Kaplan-Meier analysis to evaluate overall survival (OS) as well as Cox proportional hazards modeling to determine variables associated with OS. Propensity score matching was performed in order to assess groups in a balanced manner while reducing indication biases.

Results:

Altogether, 5126 patients met inclusion criteria; 126 (2.5%) underwent hCRT, while 5000 (97.5%) received cCRT. Temporal trends revealed that the use of hCRT is rising, especially in more recent years. Patients undergoing hCRT were older, with worse performance status, treated with biopsy only, and more likely to receive treatment at an academic facility. cCRT was associated with improved median OS (10.7 vs. 6.2 mo, P<0.001). This persisted in both Cox multivariate analysis (hazard ratio, 0.59; 95% confidence interval, 0.49-0.72; P=<0.001) and on propensity-matched analysis (median OS 8.7 vs. 6.2 mo; hazard ratio, 0.69; 95% confidence intervcal, 0.53-0.89; P=0.005).

Conclusions:

This is the first study to directly evaluate hCRT versus cCRT for patients with GBM. The use of hCRT is rising over time; practice patterns of hCRT administration are evaluated. Delivery of hCRT independently predicted for poorer OS. Prospective data is recommended to validate the findings herein.
Duodenal Adenomas in Patients With Multiple Colorectal Adenomas Without Germline APC or MUTYH Mutations
Authors: Kallenberg Frank G.J. , Latchford Andrew , Lips Nikki C. , Aalfs Cora M. , Bastiaansen Barbara A.J. , Clark Susan K. , Dekker Evelien
Published: December 2017

BACKGROUND:

Patients with genetic adenomatous polyposis syndromes have an increased risk for duodenal cancer, and clear surveillance recommendations exist for this group. However, limited data are available on the duodenal phenotype of patients with multiple colorectal adenomas (10–99) without a germline APC or MUTYH mutation.

OBJECTIVE:

We aimed to assess the frequency, extent, and progression of duodenal adenomas in patients with multiple colorectal adenomas without a germline APC or MUTYH mutation.

DESIGN:

This was an historical cohort study.

SETTINGS:

This study was undertaken at 2 polyposis registries: the Academic Medical Center in the Netherlands, and St. Mark’s Hospital in the United Kingdom.

PATIENTS:

We collected data on all patients with 10 to 99 colorectal adenomas and absent APC and MUTYH mutations, who underwent ≥1 esophagogastroduodenoscopy.

MAIN OUTCOME MEASURES:

The frequency, extent, and progression of duodenal adenomas were measured. Demographic and endoscopic data were collected, described, and compared between patients with and without duodenal adenomas.

RESULTS:

Eighty-three patients were identified, of which 8 (9.6%) had duodenal adenomas, detected at a median of 58 years (range, 45–75 y). Duodenal adenomas were detected in 6 of 8 patients at first esophagogastroduodenoscopy. At diagnosis, all 8 patients had Spigelman stage I or II disease. Two of 5 patients with duodenal adenomas who underwent follow-up esophagogastroduodenoscopies increased to stage III disease. The other 3 remained stable. No one developed duodenal cancer. No differences in demographic and endoscopic data were found between patients with and without duodenal adenomas.

LIMITATIONS:

This study was limited by its retrospective design, selection bias, and small sample size.

CONCLUSIONS:

Duodenal adenomas are found in a minority of patients with multiple colorectal adenomas without a germline APC or MUTYH mutation, at an average age of 58 years, and, at diagnosis, disease severity is mild. These results are a first step in unraveling the duodenal phenotype of these patients, which is needed to provide appropriate upper GI screening and surveillance recommendations. See Video Abstract at http://links.lww.com/DCR/A357.