bluuebunny/crossref_metadata_2025 huggingface dataset:
Bandgap control with local and interconnected LC piezoelectric shunts
Authors: Flores Parra Edgar A. , Bergamini Andrea , Lossouarn Boris , Van Damme Bart , Cenedese Mattia , Ermanni Paolo
Published: September 2017

This paper reports on the control of longitudinal wave propagation, in the kHz frequency range, using local and interconnected LC (inductance-capacitance) shunts distributed periodically along a rod. The LC shunts are connected to piezoelectric inserts and tuned to engender narrow or broad-band pass-bands in the forbidden band frequency range. The Bragg-scattering bandgaps are the result of the periodic mechanical mismatch between PMMA (polymethyl-methacrylate) of the rod and PZT (lead-zirconate-titanate). The narrow pass-bands correspond to the local configuration, where an equivalence between the mechanical impedance of the PMMA and PZT occurs around the shunt resonance frequency. Conversely, the interconnected shunts give a way to an electrical medium through which energy can propagate parallel to its mechanical counterpart, leading to broad pass-bands. This paper presents analytical models for calculating the dispersion and displacements of the 1D medium with interconnected LC shunts. An analytical formulation is also introduced to expediently identify the location of bandgaps and pass-bands in the medium comprised of local LC shunts. Moreover, analytical investigations are carried out to elucidate different physical phenomena giving rise to these pass-bands. The findings are experimentally validated using a finite periodic rod. The ability to tune the dispersion properties of the medium to control the width or depth of the bandgap, by utilizing local or interconnected shunts, offers a new and powerful application for piezoelectric shunts.
The combination of micro-resonators with spatially resolved ferromagnetic resonance
Authors: Schaffers T. , Meckenstock R. , Spoddig D. , Feggeler T. , Ollefs K. , Schöppner C. , Bonetti S. , Ohldag H. , Farle M. , Ney A.
Published: September 2017

We present two new and complementary approaches to realize spatial resolution for ferromagnetic resonance (FMR) on the 100 nm-scale. Both experimental setups utilize lithographically fabricated micro-resonators. They offer a detection sensitivity that is increased by four orders of magnitude compared with resonator-based FMR. In the first setup, the magnetic properties are thermally modulated via the thermal near-field effect generated by the thermal probe of an atomic force microscope. In combination with lock-in detection of the absorbed microwave power in the micro-resonator, a spatial resolution of less than 100 nm is achieved. The second setup is a combination of a micro-resonator with a scanning transmission x-ray microscope (STXM). Here a conventional FMR is excited by the micro-resonator while focused x-rays are used for a time-resolved snap-shot detection of the FMR excitations via the x-ray magnetic circular dichroism effect. This technique allows a lateral resolution of nominally 35 nm given by the STXM. Both experimental setups combine the advantage of low-power FMR excitation in the linear regime with high spatial resolution to study single and coupled nanomagnets. As proof-of-principle experiments, two perpendicular magnetic micro-stripes (5 μm × 1 μm) were grown and their FMR excitations were investigated using both setups.
Analysis of interface workfunction and process-induced damage of reactive-plasma-deposited ITO/SiO2/Si stack
Authors: Kamioka T. , Hayashi Y. , Isogai Y. , Nakamura K. , Ohshita Y.
Published: September 2017

Workfunction of reactive-plasma deposited indium-tin-oxide (RPD-ITO) at the ITO/SiO2 interface, which is referred as interface workfunction, and the process-induced damage are experimentally extracted for the first time based on capacitance-voltage (C-V) analysis. The estimated interface workfunction value of 4.74 eV for as-deposition condition is about 0.4 eV higher than that in the bulk determined by ultraviolet photoelectron spectroscopy (UPS). The RPD process induces the damage at the Si/SiO2 interface, and the degree of the damage is evaluated as the interface defect density (Dit) to be around 1012 cm-2eV-1. The effects of forming-gas annealing on the interface workfunction and recovery of the damage are also studied. The interface workfunction value once decreases to 4.53 eV by the annealing up to 250 oC and then turns to increase to 4.77 eV after 400 oC annealing. The damage is annihilated by the low-temperature forming-gas annealing at 200 oC.
Research on the effects of geometrical and material uncertainties on the band gap of the undulated beam
Authors: Li Yi , Xu Yanlong
Published: September 2017

Considering uncertain geometrical and material parameters, the lower and upper bounds of the band gap of an undulated beam with periodically arched shape are studied by the Monte Carlo Simulation (MCS) and interval analysis based on the Taylor series. Given the random variations of the overall uncertain variables, scatter plots from the MCS are used to analyze the qualitative sensitivities of the band gap respect to these uncertainties. We find that the influence of uncertainty of the geometrical parameter on the band gap of the undulated beam is stronger than that of the material parameter. And this conclusion is also proved by the interval analysis based on the Taylor series. Our methodology can give a strategy to reduce the errors between the design and practical values of the band gaps by improving the accuracy of the specially selected uncertain design variables of the periodical structures.
Significant increase of quantum efficiency of green InGaN quantum well by realizing step-flow growth
Authors: Tian Aiqin , Liu Jianping , Zhang Liqun , Jiang Lingrong , Ikeda Masao , Zhang Shuming , Li Deyao , Wen Pengyan , Cheng Yang , Fan Xiaowang , Yang Hui
Published: September 2017

Two-dimensional (2D) island morphologies have been widely reported for green light-emitting InGaN quantum well (QW) layers, but the step-flow morphology has not been obtained for a green InGaN QW layer to date. In this Letter, we first investigate the cause of the 2D island morphology of green InGaN QWs via a comparison study with blue InGaN QWs. The short diffusion lengths of adatoms at low growth temperatures were found to be the cause of the 2D island morphology for the green InGaN QW. Step-flow growth of green InGaN QWs was obtained by increasing the miscut angle of the c-plane GaN substrates from 0.20° to 0.48°, which reduces the atomic terrace width. Green InGaN/GaN multiple quantum wells (MQWs) with step-flow morphologies were found to have sharper well/barrier interfaces than MQWs with 2D island morphologies. The internal quantum efficiency of the green InGaN/GaN MQWs with the step-flow morphology is double that of the corresponding MQWs with the 2D island morphology at an excitation power density of 6.4 kW/cm2. Additionally, the emission linewidth of the green InGaN/GaN MQWs with the step-flow morphology is greatly reduced. As a result, the threshold currents of green laser diodes with larger miscut angles are greatly reduced.
Design, assessment and feasibility of legume-based cropping systems in three European regions
Authors: Pelzer E. , Bourlet C. , Carlsson G. , Lopez-Bellido R. J. , Jensen E. S. , Jeuffroy M.-H.
Published: September 2017

Grain legumes in cropping systems result in agronomic and environmental benefits. Nevertheless, their areas in Europe have strongly decreased over the past decades. Our aim was to design locally adapted innovative cropping systems including grain legumes for three European local pedoclimatic contexts, to assess their sustainability, and to discuss their feasibility with stakeholders. The methodology included an initial diagnosis of the most frequent cropping systems and local improvement targets in each local context (e.g. improve legume profitability, limit diseases of legumes, reduce intensive use of chemical inputs in cropping systems), the design of innovative legume-based cropping systems during a common workshop, focusing on three aims ((i) decrease pesticide use, (ii) reduce mineral N fertiliser dependency, and (iii) increase yield stability of grain legume crops and other crops of the crop sequence), and their multicriteria sustainability assessment. Stakeholders meetings were organised in each local context to discuss the feasibility of implementing the innovative cropping systems in farmers’ fields (technical implementation of cropping systems and possibility of development of legume sectors). Four to five cropping systems were designed in each local context, with crop sequences longer than references. They included at least two grain legumes (pea, faba bean, chickpea, lentil or lupine), as sole crops or intercropped with cereals. Overall sustainability was similar or improved in 71% of the legume-based cropping systems compared with their corresponding references. Among the designed cropping systems, stakeholders identified feasible ones considering both technical issues and development of legume sectors. The results indicate that reintegrating more grain legumes in the three European local contexts tested will contribute to more sustainable farming systems.
Biosolids differently affect seed yield, nodule growth, nodule-specific activity, and symbiotic nitrogen fixation of field bean
Authors: Pampana S. , Scartazza A. , Cardelli R. , Saviozzi A. , Guglielminetti L. , Vannacci G. , Mariotti M. , Masoni A. , Arduini I.
Published: September 2017

The main aim of this research was to verify whether mineral nitrogen (N) continuously released by organic fertilisers during the field bean growth cycle may be sufficiently high to enhance plant growth and seed yield but sufficiently low that it does not negatively affect nodulation and symbiotic N2 fixation. Plants were grown without N fertilisation, and with mineral and organic N (biosolids) fertilisation. All plant parts were collected and dry matter, N content, %Ndfa, and N2 fixed were measured at 8th node, flowering, and maturity stages. Nodule specific activity, N derived from soil, and N remobilisation were estimated. The nitrate concentration of soil was also determined. Biosolids reduced nodule growth, nodule fixation activity, and N2 fixation during the vegetative but not the reproductive phase. During seed filling, nodule fixation activity increased and N2 fixation was roughly twice that of the Control plants. Biosolids increased seed yield by removing the imbalance between N demand and N supply for pod growth. This may be related to an increase in nodule-specific activity due to the reduction in mineral N in the soil.
Effects of pharmacological inhibition of plasminogen binding on liver regeneration in rats
Authors: Miura Atsushi , Ishiguro Kyoko , Koizumi Kouta , Yaita Yuki , Ozaki-Masuzawa Yori , Hosono Takashi , Seki Taiichiro
Published: September 2017

The fibrinolysis system is thought to play an important role in liver regeneration. We previously found that plasminogen (Plg) is localized to the cell surface of regenerating liver tissue as well as proliferating hepatocytes in vitro. Here, we investigated the significance of Plg binding to the cell surface during liver regeneration. Pre-administration of tranexamic acid (TXA), which is a competitive inhibitor of Plg binding, to hepatectomized rats mildly delayed restoration of liver weight in vivo. Although binding of Plg to the cell membrane decreased following TXA administration, TXA showed little effect on hepatocyte proliferation in rats. We also discovered that Plg treatment did not stimulate proliferation of primary rat hepatocytes in vitro. These results suggest that Plg/plasmin potentiates liver regeneration via a pathway distinct from those through which hepatocyte proliferation is stimulated.
Identification of new channels by systematic analysis of the mitochondrial outer membrane
Authors: Krüger Vivien , Becker Thomas , Becker Lars , Montilla-Martinez Malayko , Ellenrieder Lars , Vögtle F.-Nora , Meyer Helmut E. , Ryan Michael T. , Wiedemann Nils , Warscheid Bettina , Pfanner Nikolaus , Wagner Richard , Meisinger Chris
Published: September 2017

The mitochondrial outer membrane is essential for communication between mitochondria and the rest of the cell and facilitates the transport of metabolites, ions, and proteins. All mitochondrial outer membrane channels known to date are β-barrel membrane proteins, including the abundant voltage-dependent anion channel and the cation-preferring protein-conducting channels Tom40, Sam50, and Mdm10. We analyzed outer membrane fractions of yeast mitochondria and identified four new channel activities: two anion-preferring channels and two cation-preferring channels. We characterized the cation-preferring channels at the molecular level. The mitochondrial import component Mim1 forms a channel that is predicted to have an α-helical structure for protein import. The short-chain dehydrogenase-related protein Ayr1 forms an NADPH-regulated channel. We conclude that the mitochondrial outer membrane contains a considerably larger variety of channel-forming proteins than assumed thus far. These findings challenge the traditional view of the outer membrane as an unspecific molecular sieve and indicate a higher degree of selectivity and regulation of metabolite fluxes at the mitochondrial boundary.
Subset- and tissue-defined STAT5 thresholds control homeostasis and function of innate lymphoid cells
Authors: Villarino Alejandro V. , Sciumè Giuseppe , Davis Fred P. , Iwata Shigeru , Zitti Beatrice , Robinson Gertraud W. , Hennighausen Lothar , Kanno Yuka , O’Shea John J.
Published: September 2017

Innate lymphoid cells (ILCs) patrol environmental interfaces to defend against infection and protect barrier integrity. Using a genetic tuning model, we demonstrate that the signal-dependent transcription factor (TF) STAT5 is critical for accumulation of all known ILC subsets in mice and reveal a hierarchy of STAT5 dependency for populating lymphoid and nonlymphoid tissues. We apply transcriptome and genomic distribution analyses to define a STAT5 gene signature in natural killer (NK) cells, the prototypical ILC subset, and provide a systems-based molecular rationale for its key functions downstream of IL-15. We also uncover surprising features of STAT5 behavior, most notably the wholesale redistribution that occurs when NK cells shift from tonic signaling to acute cytokine-driven signaling, and genome-wide coordination with T-bet, another key TF in ILC biology. Collectively, our data position STAT5 as a central node in the TF network that instructs ILC development, homeostasis, and function and provide mechanistic insights on how it works at cellular and molecular levels.
Modeling pacemaker deterioration with age
Authors: Sedwick Caitlin
Published: September 2017

New JGP study models how sinoatrial node pacemaker activity changes in aged hearts.
GradDock: rapid simulation and tailored ranking functions for peptide-MHC Class I docking
Authors: Kyeong Hyun-Ho , Choi Yoonjoo , Kim Hak-Sung
Published: September 2017

Motivation

The identification of T-cell epitopes has many profound translational applications in the areas of transplantation, disease diagnosis, vaccine/therapeutic protein development and personalized immunotherapy. While data-driven methods have been widely used for the prediction of peptide binders with notable successes, the structural modeling of peptide binding to MHC molecules is crucial for understanding the underlying molecular mechanism of the immunological processes.

Results

We developed GradDock, a structure-based method for the rapid and accurate modeling of peptide binding to MHC Class I (pMHC-I). GradDock explicitly models diverse unbound peptides in vacuo and inserts them into the MHC-I groove through a steered gradient descent with a topological correction process. The simulation process yields diverse structural conformations including native-like peptides. We completely revised the Rosetta score terms and developed a new ranking function specifically for pMHC-I. Using the diverse peptides, a linear programming approach is applied to find the optimal weights for the individual Rosetta score terms. Our examination revealed that a refinement of the dihedral angles and a modification of the repulsion can dramatically improve the modeling quality. GradDock is five-times faster than a Rosetta-based docking approach for pMHC-I. We also demonstrate that the predictive capability of GradDock with the re-weighted Rosetta ranking function is consistently more accurate than the Rosetta-based method with the standard Rosetta score (approximately three-times better for a cross-docking set).

Availability and implementation

GradDock is freely available for academic purposes. The program and the ranking score weights for Rosetta are available at http://bel.kaist.ac.kr/research/GradDock.

Supplementary information

Supplementary data are available at Bioinformatics online.
A comprehensive assessment of long intrinsic protein disorder from the DisProt database
Authors: Necci Marco , Piovesan Damiano , Dosztányi Zsuzsanna , Tompa Peter , Tosatto Silvio C E
Published: September 2017

Motivation

Intrinsic disorder (ID), i.e. the lack of a unique folded conformation at physiological conditions, is a common feature for many proteins, which requires specialized biochemical experiments that are not high-throughput. Missing X-ray residues from the PDB have been widely used as a proxy for ID when developing computational methods. This may lead to a systematic bias, where predictors deviate from biologically relevant ID. Large benchmarking sets on experimentally validated ID are scarce. Recently, the DisProt database has been renewed and expanded to include manually curated ID annotations for several hundred new proteins. This provides a large benchmark set which has not yet been used for training ID predictors.

Results

Here, we describe the first systematic benchmarking of ID predictors on the new DisProt dataset. In contrast to previous assessments based on missing X-ray data, this dataset contains mostly long ID regions and a significant amount of fully ID proteins. The benchmarking shows that ID predictors work quite well on the new dataset, especially for long ID segments. However, a large fraction of ID still goes virtually undetected and the ranking of methods is different than for PDB data. In particular, many predictors appear to confound ID and regions outside X-ray structures. This suggests that the ID prediction methods capture different flavors of disorder and can benefit from highly accurate curated examples.

Availability and implementation

The raw data used for the evaluation are available from URL: http://www.disprot.org/assessment/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Meta-server for automatic analysis, scoring and ranking of docking models
Authors: Anashkina Anastasia A , Kravatsky Yuri , Kuznetsov Eugene , Makarov Alexander A , Adzhubei Alexei A
Published: September 2017

Motivation

Modelling with multiple servers that use different algorithms for docking results in more reliable predictions of interaction sites. However, the scoring and comparison of all models by an expert is time-consuming and is not feasible for large volumes of data generated by such modelling.

Results

Quality ASsessment of DOcking Models (QASDOM) Server is a simple and efficient tool for real-time simultaneous analysis, scoring and ranking of data sets of receptor–ligand complexes built by a range of docking techniques. This meta-server is designed to analyse large data sets of docking models and rank them by scoring criteria developed in this study. It produces two types of output showing the likelihood of specific residues and clusters of residues to be involved in receptor–ligand interactions and the ranking of models. The server also allows visualizing residues that form interaction sites in the receptor and ligand sequence and displays 3D model structures of the receptor–ligand complexes.

Availability

http://qasdom.eimb.ru.

Supplementary information

Supplementary data are available at Bioinformatics online.
A novel SCCA approach via truncated
ℓ
1-norm and truncated group lasso for brain imaging genetics
Authors: Du Lei , Liu Kefei , Zhang Tuo , Yao Xiaohui , Yan Jingwen , Risacher Shannon L , Han Junwei , Guo Lei , Saykin Andrew J , Shen Li ,   for the Alzheimer’s Disease Neuroimaging Initiative
Published: September 2017

Motivation

Brain imaging genetics, which studies the linkage between genetic variations and structural or functional measures of the human brain, has become increasingly important in recent years. Discovering the bi-multivariate relationship between genetic markers such as single-nucleotide polymorphisms (SNPs) and neuroimaging quantitative traits (QTs) is one major task in imaging genetics. Sparse Canonical Correlation Analysis (SCCA) has been a popular technique in this area for its powerful capability in identifying bi-multivariate relationships coupled with feature selection. The existing SCCA methods impose either the ℓ1-norm or its variants to induce sparsity. The ℓ0-norm penalty is a perfect sparsity-inducing tool which, however, is an NP-hard problem.

Results

In this paper, we propose the truncated ℓ1-norm penalized SCCA to improve the performance and effectiveness of the ℓ1-norm based SCCA methods. Besides, we propose an efficient optimization algorithms to solve this novel SCCA problem. The proposed method is an adaptive shrinkage method via tuning τ. It can avoid the time intensive parameter tuning if given a reasonable small τ. Furthermore, we extend it to the truncated group-lasso (TGL), and propose TGL-SCCA model to improve the group-lasso-based SCCA methods. The experimental results, compared with four benchmark methods, show that our SCCA methods identify better or similar correlation coefficients, and better canonical loading profiles than the competing methods. This demonstrates the effectiveness and efficiency of our methods in discovering interesting imaging genetic associations.

Availability and implementation

The Matlab code and sample data are freely available at http://www.iu.edu/∼shenlab/tools/tlpscca/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Intradermal Scalp Closure Using Barbed Suture in Cranial Tumor Surgeries: A Technical Note
Authors: Buttrick Simon S , Eichberg Daniel , Ali Sheikh C , Komotar Ricardo J
Published: September 2017

BACKGROUND AND IMPORTANCE

Traditional scalp closure technique following elective craniotomy involves placement of staples or a continuous running suture. Despite low complication rates, these techniques are often considered to be disfiguring by patients, contribute to the psychosocial trauma of brain surgery, and are associated with discomfort during postoperative staple or suture removal. Some authors have described scalp closure using intradermal absorbable suture, but this technique likely does not reach the tensile strength of closure using traditional methods, and requires knots at the apices of the incision, which can act as a nidus for infection.

CLINICAL PRESENTATION

We employed a barbed intradermal closure method in supratentorial elective craniotomies for tumor resection. Complication rates were recorded, and cosmetic outcomes were informally assessed. Intradermal closure with barbed sutures was utilized in 76 patients. At the 2-wk postoperative clinic visit, cosmetic outcomes were excellent in all cases. There was 1 superficial wound infection that presented 6 wk after a pterional craniotomy for low-grade glioma. This resolved with superficial wound revision and oral antibiotic therapy.

CONCLUSION

We present a novel scalp closure technique for craniotomies using intradermal barbed Monocryl suture. We have had excellent cosmetic outcomes, and the infection rate of 1.3% compares favorably to published rates. Further studies are required to quantify the improvement in patient satisfaction compared to conventional closure methods.
Optical polarization variations in the blazar PKS 1749+096
Authors: Uemura Makoto , Itoh Ryosuke , Liodakis Ioannis , Blinov Dmitry , Nakayama Masanori , Xu Longyin , Sawada Naoko , Wu Hsiang-Yun , Fujishiro Issei
Published: September 2017

We report on the variation in the optical polarization of the blazar PKS 1749+096 observed in 2008–2015. The degree of polarization (PD) tends to increase in short flares, having a time-scale of a few days. The object favors a polarization angle (PA) of 40°–50° at the flare maxima, which is close to the position angle of the jet (20°–40°). Three clear polarization rotations were detected in the negative PA direction associated with flares. In addition, a rapid and large decrease in the PA was observed in the other two flares, while another two flares showed no large PA variation. The light-curve maxima of the flares possibly tended to lag behind the PD maxima and color-index minima. The PA became −50° to −20° in the decay phase of active states, which is almost perpendicular to the jet position angle. We propose a scenario to explain these observational features, where transverse shocks propagate along curved trajectories. The favored PA at the flare maxima suggests that the observed variations were governed by the variations in the Doppler factor, δ. Based on this scenario, the minimum viewing angle of the source, $\theta _\mathrm{min} = {4 {^{\circ}_{.}} 8}$–6${^{\circ}_{.}}$6, and the location of the source, Δr ≳ 0.1 pc, from the central black hole were estimated. In addition, the acceleration of electrons by the shock and synchrotron cooling would have a time-scale similar to that of the change in δ. The combined effect of the variation in δ and acceleration/cooling of electrons is probably responsible for the observed diversity of the polarization variations in the flares.
Income Mobility, Income Risk, and Welfare
Authors: Krebs Tom , Krishna Pravin , Maloney William F
Published: September 2017

This paper presents a framework for the quantitative analysis of individual income dynamics, mobility, and welfare, with ex ante identical individuals facing a stochastic income process and market incompleteness, implying that they are unable to insure against persistent shocks to income. We show how the parameters of the income process can be estimated using repeated cross-sectional data with a short panel dimension and use a simple consumption-saving model for quantitative analysis of mobility and welfare. Our empirical application, using data on individual incomes from Mexico, provides striking results. Most of the measured income mobility is driven by measurement error or transitory income shocks and is therefore (almost) welfare neutral. Only a small part of measured income mobility is due to either welfare-reducing income risk or welfare-enhancing catching-up of low-income individuals with high-income individuals, both of which, nevertheless, have economically significant effects on social welfare. Strikingly, roughly half of the mobility that cannot be attributed to measurement error or transitory income shocks is driven by welfare-reducing persistent income shocks. Decomposing mobility into its fundamental components is thus crucial from the standpoint of welfare evaluation.
Medicate or Meditate? Greater Pain Acceptance is Related to Lower Pain Medication Use in Persons With Chronic Pain and Spinal Cord Injury
Authors: Kratz Anna L. , F. Murphy John , Kalpakjian Claire Z. , Chen Philip
Published: September 2017

Objectives:

There is little information about whether use of pain self-management skills that are common targets of psychosocial interventions for pain are associated with reduced reliance on pain medications. The aim of this study was to test whether higher chronic pain acceptance, which is a readily modified pain self-management approach, is related to lower use of pain medications (eg, opioid medications, and gabapentinoids) in a sample with chronic pain and spinal cord injury (SCI).

Materials and Methods:

This is a cross-sectional survey study of pain medication use, pain severity and distribution (Brief Pain Inventory [BPI]), depressive symptoms (Patient Health Questionnaire-9 [PHQ-9]), and chronic pain acceptance (Chronic Pain Acceptance Questionnaire [CPAQ]) administered to a sample of 120 adults with chronic pain and SCI.

Results:

Regression results indicated that, above and beyond the effects of pain intensity, pain distribution, and depressive symptoms, higher pain acceptance was related to lower use of all types of pain medications, and lower odds of using opioid medications or gabapentinoids. Pain intensity was not related to pain medication use, but greater pain distribution was related to using more pain medications in general and to greater odds of using gabapentinoids.

Discussion:

Findings from this study indicate that those with chronic pain and SCI who have a more accepting orientation to pain are less reliant on pain medications, and thereby experience lower risks associated with medication consumption. Longitudinal, daily process, and clinical trial studies are needed to better understand the association between pain acceptance and pain medication consumption.
Stigma and Pain in Adolescents Hospitalized for Sickle Cell Vasoocclusive Pain Episodes
Authors: Martin Sarah R. , Cohen Lindsey L. , Mougianis Ifigenia , Griffin Anya , Sil Soumitri , Dampier Carlton
Published: September 2017

Objectives:

Sickle cell disease (SCD) pain and hospitalizations increase during adolescence and adolescents with SCD may be at-risk for experiencing health-related stigma, which may result in poor health outcomes. This study examined relations among health-related stigma, pain interference, social support, quality of life (QOL), and hospital outcomes (ie, loneliness, pain reduction, and length of stay [LOS]) in adolescents hospitalized with SCD pain.

Materials and Methods:

Twelve- to 18-year-old adolescents (N=92) hospitalized with SCD pain completed measures of stigma, pain interference, social support, QOL, and state loneliness. Reduction of pain intensity during hospitalization and LOS were collected from medical chart review.

Results:

Higher stigma was associated with higher pain interference, lower QOL, more loneliness, and less pain reduction in the hospital. Pain interference was positively associated with LOS.

Discussion:

These preliminary findings highlight the importance of assessing and addressing SCD-related stigma and pain interference in adolescents hospitalized for SCD pain as these factors may influence treatment outcomes.
Randomized Controlled Trial of Telephone-delivered Cognitive Behavioral Therapy Versus Supportive Care for Chronic Back Pain
Authors: Rutledge Thomas , Atkinson J. Hampton , Chircop-Rollick Tatiana , D’Andrea John , Garfin Steven , Patel Shetal , Penzien Donald B. , Wallace Mark , Weickgenant Anne L. , Slater Mark
Published: September 2017

Objective:

The objective of this study was to evaluate the efficacy of a telephone-delivered, home-based cognitive-behavioral intervention for chronic low back pain in comparison to a matched supportive care (SC) treatment.

Methods:

Participants (N=66) were patients with chronic back pain that were randomized to either an 8-week Cognitive-Behavioral Therapy (CBT) or a SC condition matched for contact frequency, format, and time. Participants completed validated measures of improvement in back pain disability, pain severity, and overall improvement.

Results:

Intent-to-treat analyses at posttreatment showed that the treatment groups not show significantly different improvements in back pain disability (mean changes, −2.4 and −2.6 for CBT and SC, respectively; Cohen d, 0.49 and 0.55, respectively) or reductions in pain severity (mean changes, −0.9 and −1.4 for CBT and SC respectively; Cohen d, 0.50, and 0.90, respectively). Participants rated their overall improvement levels at 31% (CBT) versus 18.5% (SC).

Discussion:

Results from this clinical trial suggest that home-based, telephone-delivered CBT and SC treatments did not significantly differ in their benefits for back pain severity and disability, and may warrant further research for applications to hospital settings. Major limitations included recruitment difficulties that underpowered primary analyses, the lack of objective improvement measures, and the absence of a usual care/untreated control group for comparisons.
Associations of Early Opioid Use With Patient-reported Outcomes and Health Care Utilization Among Older Adults With Low Back Pain
Authors: Gold Laura S. , Hansen Ryan N. , Avins Andrew L. , Bauer Zoya , Comstock Bryan A. , Deyo Richard A. , Heagerty Patrick J. , Rundell Sean D. , Suri Pradeep , Turner Judith A. , Jarvik Jeffrey G.
Published: September 2017

Objectives:

The objective of this study was to compare outcomes and health care utilization of older patients who did versus did not fill opioid prescriptions within 90 days of initiating care for low back pain.

Materials and Methods:

For patients ≥65 years with new back pain visits, we used propensity scores to match those who filled no opioid prescriptions to those who filled ≥2 opioid prescriptions within 90 days (and the first opioid prescription within 30 d) of the index visit. Over 24 months, we examined patient-reported outcomes, health care utilization, and subsequent opioid prescription fills.

Results:

Among 1954 patients eligible for matching, 238 (12%) filled ≥2 opioid prescriptions within 90 days; 200 of these were matched to controls. Patients with versus without early opioid prescriptions had similar patient-reported outcomes but were more likely to have filled ≥1 opioid prescription 18 to 24 months after the index visit (odds ratio [95% confidence interval]=2.4 [1.5-3.9]) and to have had ≥1 visit to the emergency department in the subsequent 24 months (OR, 1.6; 95% confidence interval, 1.0-2.5).

Discussion:

Among older patients with new back pain visits, filling ≥2 opioid prescriptions within 90 days of the visit was associated with similar back pain-related outcomes but increased likelihood of filling opioid prescriptions 18 to 24 months later compared with matched patients who did not fill early opioid prescriptions.
Defining the “Critical Elements” for the Most Common Procedures in Spine Surgery
Authors: Laratta Joseph Lawrence , Shillingford Jamal N. , Cohen-Tanugi Samuel Jeffrey , Lombardi Joseph M. , Lenke Lawrence G. , Riew K. Daniel , Lehman Ronald A. , Ludwig Steven C.
Published: September 2017

Study Design.

Survey.

Objective.

To define the critical elements of common spine surgeries.

Summary of Background Data.

Despite significant relevance to the field of spine surgery, the term “critical element” of surgery has not been clearly defined. Every surgical procedure involves numerous steps, each with its own potential for complications and harm to the patient. Despite its crucial role in surgical training, billing, and the ethicality of concurrent surgery, the term “critical element” of surgery has not been defined.

Methods.

A survey was administered to surgeons associated with AO Spine North America and the Society for Minimally Invasive Spine Surgery to determine the critical elements for four common spine procedures: open lumbar laminectomy and fusion, microdiscectomy, anterior cervical discectomy and fusion (ACDF), and posterior cervical laminectomy and fusion. Respondents were asked which steps necessitated their direct supervision. Surgical subspecialty, level of experience, and practice demographics were also recorded.

Results.

For all applicable procedures, decompression, instrumentation, and fusion were designated as critical elements. Patient positioning and fascial closure were not. Radiographic localization was considered critical for all procedures, except posterior cervical laminectomy and fusion. Exposure was not considered critical for any procedures, except ACDF. Certain substeps of decompression in ACDF and open lumbar laminectomy and fusion were not considered critical. Orthopaedic surgeons considered exposure and fusion in ACDF procedures to be critical whereas neurosurgeons did not. Surgeons operating in private practice considered every step of these common procedures to be critical elements.

Conclusion.

Decompression, instrumentation, and fusion were considered critical elements of common spine surgeries. There were significant differences in responses according to surgical specialty and practice setting. Future research is necessary to determine the implications of these findings and guide the definition of the “critical portions” of surgery.

Level of Evidence: 1
Percutaneous Posterior Transarticular Atlantoaxial Fixation for the Treatment of Odontoid Fractures in the Elderly
Authors: Alhashash Mohamed , Shousha Mootaz , Gendy Hany , Barakat Ahmed Samir , Boehm Heinrich
Published: September 2017

Study Design.

A prospective study of 20 multimorbid patients older than 65 years undergoing minimally invasive surgical treatment for odontoid fracture.

Objective.

To analyze the results of percutaneous transarticular atlantoaxial screw fixation as a new minimally invasive treatment modality in this high risk group of patients.

Summary of Background Data.

Odontoid fractures are a common injury pattern in the elderly. These fractures typically present significant challenges as geriatric patients often have multiple comorbidities that may adversely affect fracture management. Despite numerous publications on this subject, with a trend toward primary operative stabilization, the appropriate treatment for this frequent and potentially life threatening injury remains controversial.

Methods.

Between January 2013 and December 2015, 20 consecutive patients underwent posterior percutaneous transarticular atlantoaxial screw fixation for odontoid fracture type II. The two main inclusion criteria were age 65 years or older and ASA score of III or IV. The screws were inserted percutaneously with the help of two fluoroscopy devices. Clinical and radiological examinations were regularly performed for a minimum of 18 months postoperatively.

Results.

The mean age was 81 years, all of them with multiple comorbidities. Reduction of the fracture and screw insertion was possible in all cases. The mean operative time was 51.75 minutes and mean blood loss was 41.7 mL. Three patients died in the first 3 months after surgery. Healing of the fracture occurred in 15 patients (88.2%). Revision surgery was not necessary in any of the patients. Mean visual analogue scale (VAS) at the final follow-up was 2.4, and mean patient satisfaction score was 7.1.

Conclusion.

Percutaneous transarticular atlantoaxial fixation in elderly patients offers a good minimally invasive operative treatment in this multimorbid group of patients. This new technique with short operative time is well tolerated by the geriatric patients leading to a healing rate up to 88%.

Level of Evidence: 4
Risk Factors for Surgical Site Infection After Posterior Lumbar Spinal Surgery
Authors: Liu Jia-Ming , Deng Hui-Lin , Chen Xuan-Yin , Zhou Yang , Yang Dong , Duan Man-Sheng , Huang Shan-Hu , Liu Zhi-Li
Published: September 2017

Study Design.

A retrospective study.

Objective.

The purpose of this study was to identify the independent risk factors for postoperative surgical site infection (SSI) after posterior lumbar spinal surgery based on the perioperative factors analysis.

Summary of Background Data.

SSI is one of the most common complications after spinal surgery. Previous studies have identified different risk factors for postoperative SSI after lumbar spinal surgery. However, most of the studies were focused on the patient and procedure-related factors. Few studies reported the correlation between laboratory tests and postoperative SSI.

Methods.

A retrospective study was carried out in a single institution. Patients who underwent posterior lumbar spinal surgery between January 2010 and August 2016 were included in this study. All patients’ medical records were reviewed and patients with postoperative SSI were identified. Perioperative variables were included to determine the risk factors for SSI by univariate and multivariate regression analysis.

Results.

A total of 2715 patients undergoing posterior lumbar spinal surgery were included in this study. Of these patients, 64 (2.4%) were detected with postoperative SSI, including 46 men and 18 women. Diabetes mellitus (P = 0.026), low preoperative serum level of calcium (P 
= 0.009), low preoperative and postoperative albumin (P = 0.025 and 0.035), high preoperative serum glucose (P = 0.029), multiple fusion segments (P < 0.001), increased surgical time and estimated blood loss (P = 0.023 and 0.005), decreased postoperative hemoglobin (P = 0.008), and prolonged drainage duration (P = 0.016) were found to be the independent risk factors for SSI. Multilevel fusion and a history of diabetes mellitus were the two strongest risk factors (odds ratio = 2.329 and 2.227) for SSI.

Conclusion.

Based on a large population analysis, previous reported risk factors for SSI were confirmed in this study while some new independent risk factors were identified significantly associated with SSI following lumbar spinal surgery, including preoperative low serum level of calcium, decreased preoperative and postoperative albumin, and decreased postoperative hemoglobin.

Level of Evidence: 4
Capturing Plastic Surgery on Film—Making Reconstruction Visible
Authors: Lunger Alexander , Ismail Tarek , Sarraf Namita , Epple Christian , Schaefer Kristin Marit , Schaefer Dirk J.
Published: September 2017

The Swiss Plastic Surgery Association (https://plasticsurgery.ch/en/) decided to produce a corporate video to illustrate the concept of "plastic surgery of confidence" to the public. We show the diversity of specializations and the vast range of tasks that surgeons passionately handle day in and day out. We wanted to convey 2 main messages: first, that plastic surgery is more than just cosmetic surgery, and second, that plastic surgery in Switzerland is synonymous with quality and confidence. We selected 17 topics that we felt had good filmic potential and would best explain to the public what plastic surgery is about. This included the selection of appropriate patients, experts, and locations from all over the country. We thought it crucial to show the initial preoperative situation, as only in this case would the achievement of reconstruction be evident and comprehensive to the layman audience. The actual production was filmed in 5 different locations and took 5 days of shooting. We recorded 17 surgeons, 9 patients, and about 30 voluntary background actors. From 23 hours of footage, we created a 7 minute, 22 second corporate video, recorded in 3 of the Swiss national languages. The video was presented to the public online in June 2016, on the same day as the National Open Day of Plastic Surgery in Switzerland. The video is available online. We evaluated the impact of the video using a questionnaire for lay people and observed that it could substantially improve the perception of our specialty, especially regarding the reconstructive aspect. We feel that a freely available corporate video is a very useful means to promote plastic surgery and help patients better understand what it is all about.
Multimodal Analgesia in Breast Surgical Procedures: Technical and Pharmacological Considerations for Liposomal Bupivacaine Use
Authors: Afonso Anoushka M. , Newman Martin I. , Seeley Neil , Hutchins Jacob , Smith Kevin L. , Mena Gabriel , Selber Jesse C. , Saint-Cyr Michel H. , Gadsden Jeffrey C.
Published: September 2017

Enhanced recovery after surgery is a multidisciplinary perioperative clinical pathway that uses evidence-based interventions to improve the patient experience as well as increase satisfaction, reduce costs, mitigate the surgical stress response, accelerate functional recovery, and decrease perioperative complications. One of the most important elements of enhanced recovery pathways is multimodal pain management. Herein, aspects relating to multimodal analgesia following breast surgical procedures are discussed with the understanding that treatment decisions should be individualized and guided by sound clinical judgment. A review of liposomal bupivacaine, a prolonged-release formulation of bupivacaine, in the management of postoperative pain following breast surgical procedures is presented, and technical guidance regarding optimal administration of liposomal bupivacaine is provided.
Factors associated with hospital participation in Centers for Medicare and Medicaid Services' Accountable Care Organization programs
Authors: Chukmaitov Askar S. , Harless David W. , Bazzoli Gloria J. , Deng Yangyang
Published: September 2017

Background:

In 2012, the Centers for Medicare and Medicaid Services (CMS) initiated the Medicare Shared Savings Program (MSSP) and Pioneer Accountable Care Organization (ACO) programs. Organizations in the MSSP model shared cost savings they generated with CMS, and those in the Pioneer program shared both savings and losses. It is largely unknown what hospital and environmental characteristics are associated with the development of CMS ACOs with one- or two-sided risk models.

Purpose:

The aim of this study was to assess the organizational and environmental characteristics associated with hospital participation in the MSSP and Pioneer ACOs.

Methodology:

Hospitals participating in CMS ACO programs were identified using primary and secondary data. The ACO hospital sample was linked with the American Hospital Association, Health Information and Management System Society, and other data sets. Multinomial probit models were estimated that distinguished organizational and environmental factors associated with hospital participation in the MSSP and Pioneer ACOs.

Results:

Hospital participation in both CMS ACO programs was associated with prior experience with risk-based payments and care management programs, advanced health information technology, and location in higher-income and more competitive areas. Whereas various health system types were associated with hospital participation in the MSSP, centralized health systems, higher numbers of physicians in tightly integrated physician–organizational arrangements, and location in areas with greater supply of primary care physicians were associated with Pioneer ACOs. Favorable hospital characteristics were, in the aggregate, more important than favorable environmental factors for MSSP participation.

Conclusion:

MSSP ACOs may look for broader organizational capabilities from participating hospitals that may be reflective of a wide range of providers participating in diverse markets. Pioneer ACOs may rely on specific hospital and environmental characteristics to achieve quality and spending targets set for two-sided contracts.

Practice Implications:

Hospital and ACO leaders can use our results to identify hospitals with certain characteristics favorable to their participation in either one- or two-sided ACOs.
Releasable Single Suture for Primary Pterygium Excision With a Conjunctival Autograft
Authors: Parmar Gautam Singh , Arya Sachin , Meena Ashok Kumar , Ghodke Bhushan , Jain Elesh , Jain Budhendra
Published: September 2017

Purpose:

To evaluate the efficacy of a releasable single suture for pterygium excision with a conjunctival autograft (CAG).

Methods:

Retrospective case series at a tertiary eye care center in central India was conducted. Medical records of 150 patients, who underwent primary pterygium excision with a CAG secured by a single releasable 10-0 nylon suture in the last year were reviewed. The surgical duration was noted. The suture was released on the first postoperative day under topical anesthesia. Patients were followed up until 1 year. At each visit, factors studied were patient comfort [pain grading on a visual analog scale], graft apposition, complications, and recurrence.

Results:

Mean age of patients was 39 ± 11 years. Most patients in our study were female (58.7%). Sixty percent of pterygia were of Tan grade 2. The mean duration of surgery was 4.8 ± 1.3 minutes. The maximum size of the CAG was 6 mm (3–6 mm). The graft retraction rate was 5.3% (1 mm retraction in the CAG more than 5.5 mm) with no event of graft loss. Four percent of patients had grade 1 recurrence.

Conclusions:

Releasable single suture may offer a good and simple alternative, which uses the gold standard technique of the CAG with exclusion of suture-related complications.