bluuebunny/crossref_metadata_2025 huggingface dataset:
Greater sage‐grouse use of mechanical conifer reduction treatments in northwest utah
Authors: Cook Avery A. , Messmer Terry A. , Guttery Michael R.
Published: March 2017

A potential consequence of climate change, altered fire regimes, and a legacy of resource exploitation in western North America is increased displacement of desirable sagebrush (Artemisia spp.) communities by invasive plant species. Annually, an estimated 90,000 ha of sage‐grouse (Centrocercus spp.) habitat is degraded by pinyon (Pinus spp.) and juniper (Juniperus spp.; PJ) encroachment. Sage‐grouse responses to conifer encroachment may include avoidance of otherwise available habitats, lek abandonment, and subsequent population declines. Thus, restoration of PJ encroached sage‐grouse habitats that exhibit intact sagebrush understories is a priority conservation action. However, better information is needed regarding sage‐grouse response to these management actions. We used sage‐grouse fecal pellet surveys and radiotelemetry location data to identify vegetation and landscape attributes that may influence sage‐grouse use of PJ removal treatments completed using mechanical methods. Use of PJ removal treatments by sage‐grouse was positively associated with irrigated pasture and alfalfa (Medicago sativa) hay within 1 km (β = 7.69, SE = 5.58, P = 0.17) and negatively associated with PJ canopy cover (β = −1.52, SE = 0.84, P = 0.07) within 500 m of treatments. Percent cover of mesic habitats and sagebrush canopy were greater within 1 km of treatments where sage‐grouse were detected; however, these relationships were weak because of large variability in conditions across sites. Our results document sage‐grouse use of 9 of 16 mechanical PJ removal treatments examined in an encroached sagebrush landscape and suggest that mechanical PJ removal treatments should be sited adjacent to occupied sage‐grouse habitat in areas that minimize surrounding PJ cover. © 2017 The Wildlife Society.
A semi-empirical glycosylation model of a camelid monoclonal antibody under hypothermia cell culture conditions
Authors: Aghamohseni Hengameh , Spearman Maureen , Ohadi Kaveh , Braasch Katrin , Moo-Young Murray , Butler Michael , Budman Hector M
Published: March 2017

The impact of cell culture environment on the glycan distribution of a monoclonal antibody (mAb) has been investigated through a combination of experiments and modeling. A newly developed CHO DUXB cell line was cultivated at two levels of initial Glutamine (Gln) concentrations (0, 4 mM) and incubation temperatures of (33 and 37 °C) in batch operation mode. Hypothermia was applied either through the entire culture duration or only during the post-exponential phase. Beyond reducing cell growth and increasing productivity, hypothermia significantly altered the galactosylation index profiles as compared to control conditions. A novel semi-empirical dynamic model was proposed for elucidating the connections between the extracellular cell culture conditions to galactosylation index. The developed model is based on a simplified balance of nucleotides sugars and on the correlation between sugars’ levels to the galactosylation index (GI). The model predictions were found to be in a good agreement with the experimental data. The proposed empirical model is expected to be useful for controlling the glycoprofiles by manipulating culture conditions.
Elementary students’ challenges with informational texts: Reading the words and the world
Authors: Brugar Kristy A. , Roberts Kathryn L.
Published: March 2017

The purpose of this study is to describe ways in which elementary students access information from various components of informational social studies texts in schools. Although the time devoted to elementary social studies has decreased considerably in recent years, a renewed focus on content-area literacy skills, driven by state standard initiatives, presents us with the opportunity to regain lost social studies instructional time by integrating social studies content during literacy instructional time. However, it is not entirely clear what this instructional time should entail. This paper describes how third-, fourth-, and fifth-grade children navigate various aspects of the written and graphical elements of informational social studies reading materials. Results indicate that when students are unable to correctly answer questions about the content of the reading materials, they primarily attempt to do so in one of four ways: (1) responding without the use of a discernable strategy; (2) extracting random information from the passage; (3) relying on prior knowledge; or, (4) extracting information from the correct aspect of text that is not responsive to the question. Based on researcher-developed reading assessments as data sources, we explain the challenges children encounter and make recommendations for elementary social studies instruction.
Effects of traumatic brain injury and posttraumatic stress disorder on development of Alzheimer's disease in Vietnam Veterans using the Alzheimer's Disease Neuroimaging Initiative: Preliminary report
Authors: Weiner Michael W. , Harvey Danielle , Hayes Jacqueline , Landau Susan M. , Aisen Paul S. , Petersen Ronald C. , Tosun Duygu , Veitch Dallas P. , Jack Clifford R. , Decarli Charles , Saykin Andrew J. , Grafman Jordan , Neylan Thomas C. ,   Department of Defense Alzheimer's Disease Neuroimaging Initiative
Published: March 2017

Introduction

Traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) have previously been reported to be associated with increased risk of Alzheimer's disease (AD). We are using biomarkers to study Vietnam Veterans with/without mild cognitive impairment with a history of at least one TBI and/or ongoing PTSD to determine whether these contribute to the development of AD.

Methods

Potential subjects identified by Veterans Administration records underwent an initial telephone screen. Consented subjects underwent clinical evaluation, lumbar puncture, structural magnetic resonance imaging, and amyloid positron emission tomography (PET) scans.

Results

We observed worse cognitive functioning in PTSD and TBI + PTSD groups, worse global cognitive functioning in the PTSD group, lower superior parietal volume in the TBI + PTSD group, and lower amyloid positivity in the PTSD group, but not the TBI group compared to controls without TBI/PTSD. Medial temporal lobe atrophy was not increased in the PTSD and/or TBI groups.

Discussion

Preliminary results do not indicate that TBI or PTSD increase the risk for AD measured by amyloid PET. Additional recruitment, longitudinal follow‐up, and tau‐PET scans will provide more information in the future.
A description of self-similar Blow-up for dimensions $n ⩾ 3$
Authors: Bebernes J. , Eberly D.
Published: March 2017

A precise description of the asymptotic behavior near the blowup singularity for solutions of

u_t − Δu = f(u)

which blows up in finite time

T

is given.

On établie une description précise de la conduite asymptotique autour de la singularité de l’explosion totale pour la solution de l’équation

u_t − Δu = f(u)

.
Double multi‐strata space–time coded spatial modulation
Authors: Jeon Chanyong , Lee Jeong Woo
Published: March 2017

A spatial modulation (SM) using double multi‐strata space–time codes (MSSTC) is proposed, which will be called D‐MSSTC‐SM. Uneven transmit power and phase are allocated to layers of each MSSTC and rotation angles are assigned to SM codebooks to maximise the minimum coding gain distance of D‐MSSTC‐SM. It is observed that the proposed D‐MSSTC‐SM enables higher spectral efficiency and lower error probability than other conventional schemes.
Multi user MIMO‐OFDM‐based power line communication structure with hardware impairments and crosstalk
Authors: Hassan Emad S.
Published: March 2017

Broadband power line communication (BPLC) provides high speed data services without requiring the installation of new infrastructure. Multiple‐input–multiple‐output orthogonal frequency division multiplexing (MIMO‐OFDM) technology can significantly improve the BPLC performance. In this study a new multi‐user (MU) MIMO‐OFDM structure for BPLC is proposed. The effects of physical hardware impairments on the performance of this structure are also presented. Unlike to MIMO‐BPLC with ideal hardware, the hardware impairments cause a capacity limit at high signal‐to‐noise ratio (SNR). Another technical challenge in designing MIMO BPLC network is the crosstalk between MIMO PLC ports which has non‐negligible effect on network capacity. In order to reduce the effects of crosstalk, the authors propose a new scheme based on applying Pre‐coding at the transmitter before applying the singular value decomposition (SVD) on the MIMO channel. Due to the nature of the power‐line channel, the different users have different channel conditions. Thus this study also addresses the application of an efficient resource allocation algorithm to improve the overall performance of the proposed BPLC structure. The obtained results indicate that by applying the proposed resource allocation algorithm along with the Maximum Ratio Combining Pre‐coding (Pre‐MRC), the proposed structure becomes insensitive to crosstalk and has significant channel capacity compared to conventional PLC networks.
Max–min fairness based linear transceiver–relay design for MIMO interference relay channel
Authors: Singh Vindheshwari P. , Chaturvedi Ajit Kumar
Published: March 2017

In this work, the authors investigate a multi‐user multi‐input multi‐output (MIMO) interference relay system, where several transmitter nodes simultaneously communicate with their respective receiver nodes through half‐duplex MIMO amplify and forward (AF) relay nodes. For this system configuration, they address the problem of linear transceiver–relay design to achieve max–min fairness among all the users' data streams. Assuming perfect channel state information, this problem is formulated as the maximisation of the minimum signal‐to‐interference‐plus‐noise ratio (SINR) per stream among all the users subject to transmit power constraints at the transmitter and relay nodes. Since the formulated problem of jointly optimising all the transmitters, relays and receivers is non‐convex, a globally optimal solution cannot be easily obtained. Therefore, they propose a quasi‐optimal iterative algorithm to jointly optimise the transmitter precoders, relay precoding matrices and receiver filters for all the users and relays such that the minimum per stream received SINR is improved at each iteration. Simulation results show that the proposed algorithm improves fairness among data‐streams of all users and outperforms existing strategies in terms of minimum user rate and bit error rate.
Compartmentalisation‐based design automation method for power grid
Authors: Vatanparvar Korosh , Fakhouri Sani , Siddika Mst‐Ayesha , Al Faruque Mohammad Abdullah
Published: March 2017

Power grid design and maintenance are conducted to solve the problems caused by load growth over time and to stay within the constraints of voltage drop, power factor, etc. Typically, solutions to these problems are optimised individually. Considering multiple problems simultaneously and applying different solutions require vast design space exploration. This exclusively needs advanced algorithms and complex global optimisation methods which are not easily‐applicable in different scenarios. In the state‐of‐the‐art methods, for solving multiple problems simultaneously, these individually optimised solutions are applied sequentially to the power grid. In this so‐called uncoordinated method, the final solution may not be optimal solution considering all the variables, since it is considering the overlapping effect of the solutions on the power grid. To validate the compartmentalisation method, a detailed distribution grid has been modeled. After analysing the possible solutions and optimisation, power loss was reduced 45% and total cost decreased by 71%, compared to the uncoordinated method.
Pulse train‐controlled CCM boost converter with suppression of low‐frequency oscillation
Authors: Xu Ruidong , Zhang Yong , Lu Shengli , Chen Guipeng , Yu Dongsheng , Wang Long
Published: March 2017

In the conventional boost converter with pulse train (PT) control, the output voltage will produce undesirable low‐frequency oscillation in continuous conduction mode. To alleviate the problem, this study proposes a novel boost converter in which much more energy can be delivered when the output voltage is less than the reference and vice versa, the energy delivery is suppressed. The response speed of the proposed converter is greatly improved and low‐frequency oscillation is reduced. Firstly, the low‐frequency oscillation of the PT‐controlled conventional boost converter is analysed. Furthermore, the operating principles of the proposed boost converter are studied. Then the processes of start‐up and load switching are simulated. The waveforms of the steady‐state operation and the transient response of the load change are illustrated through experimental results, which indicate that the novel boost converter outperforms the traditional one in fast response, short start‐up time, small overshoot, wide load range and effective suppression of low‐frequency oscillation.
Model validation of DFIGs for power system oscillation stability analysis
Authors: Bu Siqi , Du Wenjuan , Wang Haifeng
Published: March 2017

The suitability assessment of system modelling is critical to a resource‐limited computational environment, which aims to strike a balance between the modelling accuracy and efficiency. In this study, a novel approach to evaluate the damping torque contributions from different dynamic components of doubly fed induction generator (DFIG) to system oscillation stability is first proposed. Then, this approach is employed to investigate the change of DFIG parameters (i.e. parameters of induction generator and converter controllers, and connection status), with the aim of identifying impact mechanism of these parameters on the damping torque contribution of each dynamic component. On this basis, the dynamic model of DFIGs with least orders but acceptable accuracy for oscillation stability analysis can be determined under certain parameter conditions, which undoubtedly brings significant benefits to system planner and operator to mitigate computational burden and save planning time when dealing with large‐scale power systems. In this study, the model validation of grid‐connected DFIGs is demonstrated in the New York power system ‐ New England test system (NYPS‐NETS) example system with 16 machines and 68 buses. Time‐domain simulation is used to verify the calculation results of the proposed approach.
Effects of varying the through silicon via liners thickness on their hoop stresses and deflections
Authors: Atieno Juma Mary , Zhang Xuliang , Bai He Song
Published: March 2017

Through silicon via (TSV) interconnect reliability is a problem in electronic packaging. The authors address the insertion losses, deflections which can result to separation of TSV layers and hoop stresses. These problems are due to different coefficient of thermal expansion between materials. The authors propose a robust methodology for (TSV) liners in this paper which in turn solves the reliability problem in (TSV). Silicon dioxide material is used in their paper as a TSV liner. First, they modelled the equivalent TSV circuit in advanced design systems (ADS). The authors then simulated it to obtain the TSV characterisation from which they obtained the S‐parameter S21 which represents the insertion losses. Insertion losses have been described with changes in frequencies from 0 to 20 GHz with changes in TSV thickness from 7 to 8 µm. Later two different shapes of the TSV liner; the disc‐ and rod‐shaped are modelled in analysis system 14 software. The two shapes with a radius of 5 µm each and a fixed pressure of 100 µPa developed changes in hoop stresses and deflections when the liners thicknesses are varied from 2 to 3 µm. The disc shape experienced least reliability problems so the authors propose its use in via structures.
Morphological features of IFN-γ–stimulated mesenchymal stromal cells predict overall immunosuppressive capacity
Authors: Klinker Matthew W. , Marklein Ross A. , Lo Surdo Jessica L. , Wei Cheng-Hong , Bauer Steven R.
Published: March 2017

Significance

Substantial evidence exists demonstrating the immunosuppressive function of mesenchymal stromal cells (MSCs), but inconsistent clinical results suggest that better understanding of MSC-mediated immunosuppression and identification of features predictive of immunosuppressive capacity would advance MSC-based therapeutics. In this work, we present a robust analytical approach to quantify the immunosuppressive capacity of MSCs by integrating high-dimensional flow cytometry data from multiple experimental conditions into a single measure of immunosuppressive capacity. Additionally, we identified morphological features of MSCs that predicted immunosuppressive capacity, as well as the magnitude of IFN-γ–mediated immunosuppression enhancement. These improved methods of MSC characterization could be used to identify MSC preparations with desired immunosuppressive capacity, as well as screen for pretreatments that enhance their immunosuppressive function.
Structure-guided SCHEMA recombination generates diverse chimeric channelrhodopsins
Authors: Bedbrook Claire N. , Rice Austin J. , Yang Kevin K. , Ding Xiaozhe , Chen Siyuan , LeProust Emily M. , Gradinaru Viviana , Arnold Frances H.
Published: March 2017

Significance

Critical for regulating cell function, integral membrane proteins (MPs) are key engineering targets. MP engineering is limited because these proteins are difficult to express with proper plasma membrane localization in heterologous systems. We investigate the expression, localization, and light-induced behavior of the light-gated MP channel, channelrhodopsin (ChR), because of its utility in studying neuronal circuitry. We used structure-guided SCHEMA recombination to generate libraries of chimeric ChRs that are diverse in sequence yet still capable of efficient expression, localization, and useful light-induced functionality. The conservative nature of recombination generates unique protein sequences that tend to fold and function. Recombination is also innovative: chimeric ChRs can outperform their parents or even exhibit properties not known in natural ChRs.
Fast, clash-free RNA conformational morphing using molecular junctions
Authors: Héliou Amélie , Budday Dominik , Fonseca Rasmus , van den Bedem Henry
Published: March 2017

Motivation

Non-coding ribonucleic acids (ncRNA) are functional RNA molecules that are not translated into protein. They are extremely dynamic, adopting diverse conformational substates, which enables them to modulate their interaction with a large number of other molecules. The flexibility of ncRNA provides a challenge for probing their complex 3D conformational landscape, both experimentally and computationally.

Results

Despite their conformational diversity, ncRNAs mostly preserve their secondary structure throughout the dynamic ensemble. Here we present a kinematics-based procedure to morph an RNA molecule between conformational substates, while avoiding inter-atomic clashes. We represent an RNA as a kinematic linkage, with fixed groups of atoms as rigid bodies and rotatable bonds as degrees of freedom. Our procedure maintains RNA secondary structure by treating hydrogen bonds between base pairs as constraints. The constraints define a lower-dimensional, secondary-structure constraint manifold in conformation space, where motions are largely governed by molecular junctions of unpaired nucleotides. On a large benchmark set, we show that our morphing procedure compares favorably to peer algorithms, and can approach goal conformations to within a low all-atom RMSD by directing fewer than 1% of its atoms. Our results suggest that molecular junctions can modulate 3D structural rearrangements, while secondary structure elements guide large parts of the molecule along the transition to the correct final conformation.

Availability and Implementation

The source code, binaries and data are available at https://simtk.org/home/kgs.

Supplementary information

Supplementary data are available at Bioinformatics online.
Seasonal distribution and reproductive strategy of seahorses
Authors: Qin Geng , Zhang Yanhong , Ho Adeljean L. F. C. , Zhang Yuan , Lin Qiang
Published: March 2017

The unique morphology and life history characteristics make seahorses excellent flagship species for marine ecosystems. The ecological rarity of seahorses has made it difficult to address fundamental demographic processes of seahorses, such as seasonal migration and ecological characteristics. This 3-year investigation evaluated, for the first time, the seasonal distribution of a wild seahorse, Hippocampus mohnikei, and its ecological significance. The results revealed a significant difference in the abundance of wild H. mohnikei populations between warm and cold seasons, indicating that seahorses might undertake a seasonal inshore-offshore migration every year. A total of 42 794 samples were taken during the 3-year survey in the Laizhou Bay, and migratory seahorses had the highest reproductive rates from July to September each year, suggesting that seahorse reproduction might be an important trigger for variation in distribution and migration. Moreover, water temperature might also affect the temporal and spatial abundance of migratory seahorses. There was no genetic subdivision among the different geographical populations of H. mohnikei along China’s coast. In conclusion, this study confirmed that large-scale seasonal seahorse migrations occur periodically and that reproduction is one of the important drivers, suggesting that closed-season fishing of breeding grounds is essential and applicable for seahorse conservation.
NBS1 is regulated by two kind of mechanisms: ATM-dependent complex formation with MRE11 and RAD50, and cell cycle–dependent degradation of protein
Authors: Zhou Hui , Kawamura Kasumi , Yanagihara Hiromi , Kobayashi Junya , Zhang-Akiyama Qiu-Mei
Published: March 2017

Nijmegen breakage syndrome (NBS), a condition similar to Ataxia-Telangiectasia (A-T), is a radiation-hypersensitive genetic disorder showing chromosomal instability, radio-resistant DNA synthesis, immunodeficiency, and predisposition to malignances. The product of the responsible gene, NBS1, forms a complex with MRE11 and RAD50 (MRN complex). The MRN complex is necessary for the DNA damage–induced activation of ATM. However, the regulation of MRN complex formation is still unclear. Here, we investigated the regulatory mechanisms of MRN complex formation. We used an immunoprecipitation assay to determine whether levels of the MRN complex were increased by radiation-induced DNA damage and found that the levels of these proteins and their mRNAs did not increase. ATM-dependent phosphorylation of NBS1 contributed to the DNA damage–induced MRN complex formation. However, pre-treatment of cells with an ATM-specific inhibitor did not affect homologous recombination (HR) and non-homologous end-joining (NHEJ) repair. G0 phase cells, decreasing NBS1 and HR activity but not NHEJ, gained HR-related chromatin association of RAD51 by overexpression of NBS1, suggesting that the amount of NBS1 may be important for repressing accidental activation of HR. These evidences suggest that NBS1 is regulated by two kind of mechanisms: complex formation dependent on ATM, and protein degradation mediated by an unknown MG132-resistant pathway. Such regulation of NBS1 may contribute to cellular responses to double-strand breaks.
Posterior Inferior Cerebellar Artery/Vertebral Artery Subarachnoid Hemorrhage: A Comparison of Saccular vs Dissecting Aneurysms
Authors: Foster Mitchell T , Herwadkar Amit , Patel Hiren C
Published: March 2017

BACKGROUND

Two distinct categories of aneurysms are described in relation to the posterior inferior cerebellar artery (PICA) and vertebral artery (VA): saccular (SA) and dissecting (DA) types. This distinction is often unrecognized because abnormalities here are uncommon and most studies are small.

OBJECTIVE

To determine if there are any differences in the clinical presentation, in-hospital course, or outcomes in patients with DA vs SA of the PICA or VA.

METHODS

Thirty-eight patients with a VA or PICA aneurysm were identified from a departmental subarachnoid hemorrhage database and categorized into DA or SA types. Prospectively collected demographic and outcome data (length of stay, discharge Glasgow Outcome Score) were supplemented by abstracting records for procedural data (extraventricular drain [EVD], ventriculoperitoneal [VP] shunt, tracheostomy, and nasogastric feeding). Univariate, binary logistic regression, and Cox regression analysis was used to compare patients with SA vs DA.

RESULTS

Three aneurysms related to arteriovenous malformation were excluded. Five patients were conservatively managed. Of the 30 treated cases, more patients with a DA presented in poor grade (6/13 vs 2/17 SA; P = .035). More DA patients required an EVD (85% vs 29%; P = .003), VP shunt (54% vs 6%; P = .003), tracheostomy (46% vs 6%; P < .01), and nasogastric feeding (85% vs 35%; P = .007). The median length of stay (41 vs 17 d, P < .001) was longer, and the age and injury severity adjusted odds of discharge home were significantly lower in the DA group (P = .008). Thirty-day mortality was not significantly different (23% of DA vs 24% of SA; P = .2).

CONCLUSION

The presentation, clinical course, and outcomes differ in patients with DA vs SA of the PICA and VA.
Re-operation After Long-Segment Fusions for Adult Spinal Deformity: The Impact of Extending the Construct Below the Lumbar Spine
Authors: Witiw Christopher D , Fessler Richard G , Nguyen Stacie , Mummaneni Praveen , Anand Neel , Blaskiewicz Donald , Uribe Juan , Wang Michael Y , Kanter Adam S , Okonkwo David , Park Paul , Deviren Vedat , Akbarnia Behrooz A , Eastlack Robert K , Shaffrey Christopher , Mundis Gregory M ,   on behalf of the International Spine Study Group
Published: March 2017

BACKGROUND

Deciding where to end a long-segment fusion for adult spinal deformity (ASD) may be a challenge, particularly in the absence of an abnormality at L5/S1. Some suggest prophylactic extension of the construct to the sacrum and/or ilium (S/I) to protect against distal junctional failure, while others support terminating in the lower lumbar spine to preserve motion.

OBJECTIVE

To compare the risk of re-operation after long-segment fusions for ASD that ends at L4 or L5 (L4/5) vs S/I.

METHODS

A multicenter database of patients treated for ASD by circumferential minimally invasive surgery or hybrid surgical technique was screened for individuals with long fusions (≥4 vertebral levels) ending at L4 or below and with at least 2 yr of follow-up. Multivariate regression modeling was used to compare surgical morbidity between the L4/5 and S/I groups, and Cox proportional hazard modeling was used to compare risk of re-operation.

RESULTS

There were 45 subjects with fusion to L4/5 and 71 to S/I. Over a 32-mo median follow-up, 41 re-operations were performed; 6 were for distal junctional failure. In those with normal or mild degeneration at L5/S1, fusion to S/I afforded no significant change in re-operative risk (hazard ratio = 1.18 [95% confidence interval: 0.53-2.62], P = .682). In those undergoing circumferential minimally invasive surgery correction, fusion to S/I was associated with significantly greater blood loss (499.6 cc, P < .001) and surgical time (97.5 min, P = .04).

CONCLUSION

In the setting of a normal or mildly degenerated L5/S1 disc space, fusion to the sacrum/ilium did not significantly change the risk of requiring a re-operation after a long-segment fusion for ASD.
Long-term Effects of Remote Ischemic Preconditioning on Kidney Function in High-risk Cardiac Surgery Patients
Authors: Zarbock Alexander , Kellum John A. , Van Aken Hugo , Schmidt Christoph , Küllmar Mira , Rosenberger Peter , Martens Sven , Görlich Dennis , Meersch Melanie
Published: March 2017

Background

In a multicenter, randomized trial, the authors enrolled patients at high-risk for acute kidney injury as identified by a Cleveland Clinic Foundation score of 6 or more. The authors enrolled 240 patients at four hospitals and randomized them to remote ischemic preconditioning or control. The authors found that remote ischemic preconditioning reduced acute kidney injury in high-risk patients undergoing cardiac surgery. The authors now report on the effects of remote ischemic preconditioning on 90-day outcomes.

Methods

In this follow-up study of the RenalRIP trial, the authors examined the effect of remote ischemic preconditioning on the composite endpoint major adverse kidney events consisting of mortality, need for renal replacement therapy, and persistent renal dysfunction at 90 days. Secondary outcomes were persistent renal dysfunction and dialysis dependence in patients with acute kidney injury.

Results

Remote ischemic preconditioning significantly reduced the occurrence of major adverse kidney events at 90 days (17 of 120 [14.2%]) versus control (30 of 120 [25.0%]; absolute risk reduction, 10.8%; 95% CI, 0.9 to 20.8%; P = 0.034). In those patients who developed acute kidney injury after cardiac surgery, 2 of 38 subjects in the remote ischemic preconditioning group (5.3%) and 13 of 56 subjects in the control group (23.2%) failed to recover renal function at 90 days (absolute risk reduction, 17.9%; 95% CI, 4.8 to 31.1%; P = 0.020). Acute kidney injury biomarkers were also increased in patients reaching the major adverse kidney event endpoint compared to patients who did not.

Conclusions

Remote ischemic preconditioning significantly reduced the 3-month incidence of a composite endpoint major adverse kidney events consisting of mortality, need for renal replacement therapy, and persistent renal dysfunction in high-risk patients undergoing cardiac surgery. Furthermore, remote ischemic preconditioning enhanced renal recovery in patients with acute kidney injury.
Evidence-based Pediatric Orthopaedics: How Safe is “Safe”?
Authors: Augustithis G. Alexander , Ensor Hannah Margaret , Huntley James S.
Published: March 2017

Background:

The aim of minimizing the risks of complications and adverse events is at the center of surgical practice.

This study aimed to assess the evidence on which pediatric orthopaedic surgical procedures are described as “safe.” In particular, the objective was to ascertain the proportion of studies describing a procedure as “safe,” which achieved a 95% upper limit confidence interval of risk of 5% or less for major adverse events.

Method:

A primary search of Journal of Paediatric Orthopaedics 2009 to 2014 for the single term “safe” returned 71 papers appropriate for analysis. Of these, 60 positively identified at least 1 intervention as “safe.” These papers were analyzed and the number of interventions and the number of complications recorded. Data sets (n=67) were created and the 95% upper confidence interval calculated for the probability of a complication.

Results:

Only 16 data sets (ex 67) provided evidence that the probability of a major complication was under 5%.

Conclusions:

This work suggests there is widespread failure of understanding of how low sample sizes or can lead to an unjustifiable claim that procedures are “safe.”

Level of Evidence:

Unclassifiable.
Delirium and Mortality in Critically Ill Children: Epidemiology and Outcomes of Pediatric Delirium*
Authors: Traube Chani , Silver Gabrielle , Gerber Linda M. , Kaur Savneet , Mauer Elizabeth A. , Kerson Abigail , Joyce Christine , Greenwald Bruce M.
Published: March 2017

Objectives:

Delirium occurs frequently in adults and is an independent predictor of mortality. However, the epidemiology and outcomes of pediatric delirium are not well-characterized. The primary objectives of this study were to describe the frequency of delirium in critically ill children, its duration, associated risk factors, and effect on in-hospital outcomes, including mortality. Secondary objectives included determination of delirium subtype, and effect of delirium on duration of mechanical ventilation, and length of hospital stay.

Design:

Prospective, longitudinal cohort study.

Setting:

Urban academic tertiary care PICU.

Patients:

All consecutive admissions from September 2014 through August 2015.

Interventions:

Children were screened for delirium twice daily throughout their ICU stay.

Measurements and Main Results:

Of 1,547 consecutive patients, delirium was diagnosed in 267 (17%) and lasted a median of 2 days (interquartile range, 1–5). Seventy-eight percent of children with delirium developed it within the first 3 PICU days. Most cases of delirium were of the hypoactive (46%) and mixed (45%) subtypes; only 8% of delirium episodes were characterized as hyperactive delirium. In multivariable analysis, independent predictors of delirium included age less than or equal to 2 years old, developmental delay, severity of illness, prior coma, mechanical ventilation, and receipt of benzodiazepines and anticholinergics. PICU length of stay was increased in children with delirium (adjusted relative length of stay, 2.3; CI = 2.1–2.5; p < 0.001), as was duration of mechanical ventilation (median, 4 vs 1 d; p < 0.001). Delirium was a strong and independent predictor of mortality (adjusted odds ratio, 4.39; CI = 1.96–9.99; p < 0.001).

Conclusions:

Delirium occurs frequently in critically ill children and is independently associated with mortality. Some in-hospital risk factors for delirium development are modifiable. Interventional studies are needed to determine best practices to limit delirium exposure in at-risk children.
Cumulative Probability and Time to Reintubation in U.S. ICUs
Authors: Miltiades Andrea N. , Gershengorn Hayley B. , Hua May , Kramer Andrew A. , Li Guohua , Wunsch Hannah
Published: March 2017

Objective:

Reintubation after liberation from mechanical ventilation is viewed as an adverse event in ICUs. We sought to describe the frequency of reintubations across U.S. ICUs and to propose a standard, appropriate time cutoff for reporting of reintubation events.

Design and Setting:

We conducted a cohort study using data from the Project IMPACT database of 185 diverse ICUs in the United States.

Patients:

We included patients who received mechanical ventilation and excluded patients who received a tracheostomy, had a do-not-resuscitate order placed, or died prior to first extubation.

Measurements and Main Results:

We assessed the percentage of patients extubated who were reintubated; the cumulative probability of reintubation, with death and do-not-resuscitate orders after extubation modeled as competing risks, and time to reintubation. Among 98,367 patients who received mechanical ventilation without death or tracheostomy prior to extubation, 9,907 (10.1%) were reintubated, with a cumulative probability of 10.0%. Median time to reintubation was 15 hours (interquartile range, 2–45 hr). Of patients who required reintubation in the ICU, 90% did so within the first 96 hours after initial extubation; this was consistent across various patient subtypes (89.3% for electives surgical patients up to 94.8% for trauma patients) and ICU subtypes (88.6% for cardiothoracic ICUs to 93.5% for medical ICUs).

Conclusions:

The reintubation rate for ICU patients liberated from mechanical ventilation in U.S. ICUs is approximately 10%. We propose a time cutoff of 96 hours for reintubation definitions and benchmarking efforts, as it captures 90% of ICU reintubation events. Reintubation rates can be reported as simple percentages, without regard for deaths or changes in goals of care that might occur.
Coffee and cancer risk: a summary overview
Authors: Alicandro Gianfranco , Tavani Alessandra , La Vecchia Carlo
Published: March 2017

We reviewed available evidence on coffee drinking and the risk of all cancers and selected cancers updated to May 2016. Coffee consumption is not associated with overall cancer risk. A meta-analysis reported a pooled relative risk (RR) for an increment of 1 cup of coffee/day of 1.00 [95% confidence interval (CI): 0.99–1.01] for all cancers. Coffee drinking is associated with a reduced risk of liver cancer. A meta-analysis of cohort studies found an RR for an increment of consumption of 1 cup/day of 0.85 (95% CI: 0.81–0.90) for liver cancer and a favorable effect on liver enzymes and cirrhosis. Another meta-analysis showed an inverse relation for endometrial cancer risk, with an RR of 0.92 (95% CI: 0.88–0.96) for an increment of 1 cup/day. A possible decreased risk was found in some studies for oral/pharyngeal cancer and for advanced prostate cancer. Although data are mixed, overall, there seems to be some favorable effect of coffee drinking on colorectal cancer in case–control studies, in the absence of a consistent relation in cohort studies. For bladder cancer, the results are not consistent; however, any possible direct association is not dose and duration related, and might depend on a residual confounding effect of smoking. A few studies suggest an increased risk of childhood leukemia after maternal coffee drinking during pregnancy, but data are limited and inconsistent. Although the results of studies are mixed, the overall evidence suggests no association of coffee intake with cancers of the stomach, pancreas, lung, breast, ovary, and prostate overall. Data are limited, with RR close to unity for other neoplasms, including those of the esophagus, small intestine, gallbladder and biliary tract, skin, kidney, brain, thyroid, as well as for soft tissue sarcoma and lymphohematopoietic cancer.
Estrogen and DPP-4 inhibitor share similar efficacy in reducing brain pathology caused by cardiac ischemia-reperfusion injury in both lean and obese estrogen-deprived rats
Authors: Pratchayasakul Wasana , Sivasinprasasn Sivaporn , Sa-Nguanmoo Piangkwan , Proctor Cicely , Kerdphoo Sasiwan , Chattipakorn Nipon , Chattipakorn Siriporn C.
Published: March 2017

Objective:

Cardiac ischemia-reperfusion injury (I/R) caused an oxidative burst, increased beta-amyloid production, and decreased dendritic spine density in the brain. However, the effect of cardiac I/R in the brain of estrogen-deprived rats who were or were not obese have not been investigated. Moreover, the benefits of estrogen or dipeptidyl peptidase-4 (DDP-4) inhibitor therapies in those conditions have never been determined. We hypothesized that cardiac I/R aggravates brain pathology in estrogen-deprived obese rats, to a greater extent when compared with estrogen-deprived lean rats, and treatment with either estrogen or a DPP-4 inhibitor attenuates those adverse effects.

Methods:

In protocol 1, rats were divided into sham operation (n = 12) or ovariectomy (n = 24). Sham-operated rats were fed with normal diet (ND) and ovariectomized rats were fed with either ND or high-fat diet (HF) for 12 weeks. Then, rats were subdivided to sham operation or cardiac I/R injury. In protocol 2, ovariectomized rats were given either ND (n = 18) or HF (n = 18). At week 13, ovariectomized rats were subdivided to receive vehicle, estradiol, or DPP-4 inhibitor for 4 weeks. Then, all rats were subjected to cardiac I/R.

Results:

Cardiac I/R injury aggravated brain oxidative stress, beta-amyloid production, and decreased dendritic spine density in either sham-operated or ovariectomized ND-fed rats, but not in ovariectomized HF-fed rats. Either estrogen or DPP-4 inhibitor therapies reduced those conditions in all rats with cardiac I/R.

Conclusions:

Cardiac I/R aggravates brain toxicity in estrogen-deprived lean rats, but not in the estrogen-deprived obese rats. Estrogen and DPP-4 inhibitor treatments attenuate those effects in all groups.
Racial Differences and Disparities in Osteoporosis-related Bone Health
Authors: Cram Peter , Saag Kenneth G. , Lou Yiyue , Edmonds Stephanie W. , Hall Sylvie F. , Roblin Douglas W. , Wright Nicole C. , Jones Michael P. , Wolinsky Fredric D.
Published: March 2017

Background:

Determining whether observed differences in health care can be called disparities requires persistence of differences after adjustment for relevant patient, provider, and health system factors. We examined whether providing dual-energy x-ray absorptiometry (DXA) test results directly to patients might reduce or eliminate racial differences in osteoporosis-related health care.

Design, Subjects, and Measures:

We analyzed data from 3484 white and 1041 black women who underwent DXA testing at 2 health systems participating in the Patient Activation after DXA Result Notification (PAADRN) pragmatic clinical trial (ClinicalTrials.gov NCT-01507662) between February 2012 and August 2014. We examined 7 outcomes related to bone health at 12 weeks and 52 weeks post-DXA: (1) whether the patient correctly identified their DXA baseline results; (2) whether the patient was on guideline-concordant osteoporosis pharmacotherapy; (3) osteoporosis-related satisfaction; (4) osteoporosis knowledge; (5 and 6) osteoporosis self-efficacy for exercise and for diet; and (7) patient activation. We examined whether unadjusted differences in outcomes between whites and blacks persisted after adjusting for patient, provider, and health system factors.

Results:

Mean age was 66.5 years and 29% were black. At baseline black women had less education, poorer health status, and were less likely to report a history of osteoporosis (P<0.001 for all). In unadjusted analyses black women were less likely to correctly identify their actual DXA results, more likely to be on guideline-concordant therapy, and had similar patient activation. After adjustment for patient demographics, baseline health status and other factors, black women were still less likely to know their actual DXA result and less likely to be on guideline-concordant therapy, but black women had greater patient activation.

Conclusions:

Adjustment for patient and provider level factors can change how racial differences are viewed, unmasking new disparities, and providing explanations for others.
Immunohistochemical Characterization of Fumarate Hydratase (FH) and Succinate Dehydrogenase (SDH) in Cutaneous Leiomyomas for Detection of Familial Cancer Syndromes
Authors: Carter Cody S. , Skala Stephanie L. , Chinnaiyan Arul M. , McHugh Jonathan B. , Siddiqui Javed , Cao Xuhong , Dhanasekaran Saravana M. , Fullen Douglas R. , Lagstein Amir , Chan May P. , Mehra Rohit
Published: March 2017

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is caused by germline mutations in the FH gene, and is associated with increased incidence of leiomyomas and a potentially aggressive variant of renal cell carcinoma (HLRCC-associated RCC). Absent immunohistochemical expression of fumarate hydratase (FH) has previously been used to diagnose HLRCC-associated RCC, but immunohistochemical staining of leiomyomas is not standard practice. We performed immunohistochemistry (IHC) on whole sections from consecutive cutaneous leiomyomas from our archives to evaluate for both FH and succinate dehydrogenase B expression, in addition to clinicopathologic data collection and review of all hematoxylin and eosin–stained slides for blinded morphologic evaluation of features reported to be seen in HLRCC-associated uterine leiomyomas. Ninety-six cutaneous leiomyomas from 87 patients were identified; 12 of these specimens were from 7 patients with documented HLRCC. FH expression by IHC was absent in 9 specimens and retained in 85 specimens; 2 cases were equivocal with minimal FH expression. Seven of the 9 absent expression specimens were from patients with HLRCC, as were both of the equivocal specimens. The overall sensitivity and specificity of absent FH expression in leiomyomas for detection of patients with HLRCC were 70.0% and 97.6%, respectively. Inclusion of cases classified as equivocal increased sensitivity to 75.0%. Succinate dehydrogenase B expression was retained in 95 specimens and equivocal in 1 specimen. None of the evaluated morphologic features showed any association with leiomyomas in HLRCC. Loss of FH immunohistochemical expression in cutaneous leiomyomas is a sensitive and specific marker for detection of HLRCC, thus suggesting a role for prospective FH IHC in patients with these tumors to screen for HLRCC.
Impact of Donor Age on Recipient Survival in Adult-to-Adult Living-donor Liver Transplantation
Authors: Kubota Toyonari , Hata Koichiro , Sozu Takashi , Ueda Yoshihide , Hirao Hirofumi , Okamura Yusuke , Tamaki Ichiro , Yoshikawa Junichi , Kusakabe Jiro , Tanaka Hirokazu , Kageyama Shoichi , Anazawa Takayuki , Yoshizawa Atsushi , Yagi Shintaro , Yamashiki Noriyo , Okajima Hideaki , Kaido Toshimi , Uemoto Shinji
Published: March 2017

Objective:

To investigate the influence of donor age on recipient outcome after living-donor partial liver transplantation (LDLT).

Background:

Donor age is a well-known prognostic factor in deceased donor liver transplantation; however, its role in LDLT remains unclear.

Methods:

We retrospectively analyzed 315 consecutive cases of primary adult-to-adult LDLT in our center between April 2006 and March 2014. Recipients were divided into 5 groups according to the donor age: D-20s (n = 60); D-30s (n = 72); D-40s (n = 57); D-50s (n = 94); and D-60s (n = 32). The recipient survival and the association with various clinical factors were investigated.

Results:

Recipient survival proportions were significantly higher in D-20s compared with all the other groups (P = 0.008, < 0.001, < 0.001, and = 0.006, vs D-30s, -40s, -50s, and -60s, respectively), whereas there was no association between recipient survival and their own age. There are 3 typical relationships between donors and recipients in adult-to-adult LDLT: from child-to-parent, between spouses/siblings, and from parent-to-child. The overall survival in child-to-parent was significantly higher than in spouses/siblings (P = 0.002) and in parent-to-child (P = 0.005), despite significantly higher recipient age in child-to-parent [59 (42–69) years, P < 0.001]. Contrastingly, parent-to-child exhibited the lowest survival, despite the youngest recipient age [26 (20–43) years, P < 0.001]. In addition, younger donor age exhibited significantly better recipient survival both in hepatitis C virus-related and in non-hepatitis C virus diseases. Univariate and multivariate analyses both demonstrated that donor age and graft-type (right-sided livers) are independent prognostic factors for recipient survival.

Conclusions:

Donor age is an independent, strong prognostic factor in adult-to-adult LDLT.