bluuebunny/crossref_metadata_2025 huggingface dataset:
Patients with sciatica still experience pain and disability 5 years after surgery: A systematic review with meta‐analysis of cohort studies
Authors: Machado G.C. , Witzleb A.J. , Fritsch C. , Maher C.G. , Ferreira P.H. , Ferreira M.L.
Published: May 2016

Background and objective

The clinical course of patients with sciatica is believed to be favourable, but there is conflicting evidence on the postoperative course of this condition. We aimed to investigate the clinical course of sciatica following surgery.

Databases and data treatment

An electronic search was conducted on MEDLINE, EMBASE and CINAHL from inception to April 2015. We screened for prospective cohort studies investigating pain or disability outcomes for patients with sciatica treated surgically. Fractional polynomial regression analysis was used to generate pooled means and 95% confidence intervals (CI) of pain and disability up to 5 years after surgery. Estimates of pain and disability (converted to a 0–100 scale) were plotted over time, from inception to last available follow‐up time.

Results

Forty records (39 cohort studies) were included with a total of 13,883 patients with sciatica. Before surgery, the pooled mean leg pain score was 75.2 (95% CI 68.1–82.4) which reduced to 15.3 (95% CI 8.5–22.1) at 3 months. Patients were never fully recovered in the long‐term and pain increased to 21.0 (95% CI 12.5–29.5) at 5 years. The pooled mean disability score before surgery was 55.1 (95% CI 52.3–58.0) and this decreased to 15.5 (95% CI 13.3–17.6) at 3 months, and further reduced to 13.1 (95% CI 10.6–15.5) at 5 years.

Conclusions

Although surgery is followed by a rapid decrease in pain and disability by 3 months, patients still experience mild to moderate pain and disability 5 years after surgery.

What does this review add?

This review provides a quantitative summary of the postoperative course of patients with sciatica. Patients with sciatica experienced a rapid reduction in pain and disability in the first 3 months, but still had mild to moderate symptoms 5 years after surgery. Although no significant differences were found, microdiscectomy showed larger improvements compared to other surgical techniques.
Forensic discrimination of vaginal epithelia by DNA methylation analysis through pyrosequencing
Authors: Antunes Joana , Silva Deborah S.B.S. , Balamurugan Kuppareddi , Duncan George , Alho Clarice S. , McCord Bruce
Published: May 2016

The accurate identification of body fluids from crime scenes can aid in the discrimination between criminal and innocent intent. This research aimed to determine if the levels of DNA methylation in the locus PFN3A could be used to discriminate vaginal epithelia from other body fluids. In this work we bisulfite‐modified and amplified DNA samples from blood, saliva, semen, and vaginal epithelia using primers for PFN3A. Through pyrosequencing we were able to show that vaginal epithelia present distinct methylation levels when compared to other body fluids. Mixtures of different body fluids present methylation values that correlate with single‐source body fluid samples and the primers for PFN3A are specific for primates. This report successfully demonstrated that the analysis of methylation in the PFN3A locus can be used for vaginal epithelia discrimination in forensic samples.
Vertical acceleration demands on column lines of steel moment‐resisting frames
Authors: Moschen Lukas , Medina Ricardo A. , Adam Christoph
Published: May 2016

In this paper, vertical peak floor acceleration (PFAv) demands on elastic multistory buildings are statistically evaluated using recorded ground motions. These demands are applicable to the assessment of nonstructural components that are rigid in the vertical direction and located at column lines or next to columns. Hence, PFAv demands of the floor system away from column lines and their effects on nonstructural components are not addressed. This study is motivated by the questionable general assumption that typical buildings are considered to be relatively flexible in the horizontal (lateral) direction but relatively rigid in the vertical (longitudinal) direction. Consequently, only few papers address the evaluation of vertical component acceleration demands throughout a building, and there is no consensus on the relevance of vertical accelerations in buildings. The results presented in this study show that the vertical ground acceleration demands are amplified throughout the column line of a steel frame structure. This amplification is in many cases significant, depending on the vertical stiffness of the load‐bearing system, damping ratio, and the location of the nonstructural component in the building. From these outcomes it can be concluded that the perception of a rigid‐body response of the column lines in the vertical direction is highly questionable, and further research on this topic is required. Copyright © 2016 John Wiley & Sons, Ltd.
Survival in patients with acute myeloblastic leukemia in Germany and the United States: Major differences in survival in young adults
Authors: Pulte Dianne , Jansen Lina , Castro Felipe A. , Krilaviciute Agne , Katalinic Alexander , Barnes Benjamin , Ressing Meike , Holleczek Bernd , Luttmann Sabine , Brenner Hermann ,   for the GEKID Cancer Survival Working Group
Published: May 2016

Previous epidemiologic studies on AML have been limited by the rarity of the disease. Here, we present population level data on survival of patients with AML in Germany and the United States (US). Data were extracted from 11 population‐based cancer registries in Germany and the Surveillance, Epidemiology, and End Results (SEER13) database in the US. Patients diagnosed with AML in 1997–2011 were included. Period analysis was used to estimate 5‐year relative survival (RS) and trends in survival in the early 21st century. Overall 5‐year age‐adjusted RS for patients with AML in 2007–2011 was greater in Germany than in the US at 22.8% and 18.8%, respectively. Five‐year RS was higher in Germany than in the US at all ages, with particularly large differences at ages 15–24 for whom 5‐year RS was 64.3% in Germany and 55.0% in the US and 35–44, with 5‐year RS estimates of 61.8% in Germany and 46.6% in the US. Most of the difference in 5‐year RS was due to higher 1‐year RS, with overall 1‐year RS estimates of 47.0% in Germany and 38.5% in the US. A small increase in RS was observed between 2003–2005 and 2009–2011 in both countries, but no increase in survival was observed in either country for ages 75+. To our knowledge, this is the first detailed description of AML survival in Germany. Comparison to the US suggests that further analysis into risk factors for poor outcomes in AML in the US may be useful in improving survival.
A survey of publication practices of single‐case design researchers when treatments have small or large effects
Authors: Shadish William R. , Zelinsky Nicole A. M. , Vevea Jack L. , Kratochwill Thomas R.
Published: May 2016

The published literature often underrepresents studies that do not find evidence for a treatment effect; this is often called publication bias. Literature reviews that fail to include such studies may overestimate the size of an effect. Only a few studies have examined publication bias in single‐case design (SCD) research, but those studies suggest that publication bias may occur. This study surveyed SCD researchers about publication preferences in response to simulated SCD results that show a range of small to large effects. Results suggest that SCD researchers are more likely to submit manuscripts that show large effects for publication and are more likely to recommend acceptance of manuscripts that show large effects when they act as a reviewer. A nontrivial minority of SCD researchers (4% to 15%) would drop 1 or 2 cases from the study if the effect size is small and then submit for publication. This article ends with a discussion of implications for publication practices in SCD research.
Parametric analysis of delayed primary and conditioned reinforcers
Authors: Leon Yanerys , Borrero John C. , DeLeon Iser G.
Published: May 2016

We examined the effects of delayed reinforcement on the responding of individuals with intellectual disabilities. Three conditions were evaluated: (a) food reinforcement, (b) token reinforcement with a postsession exchange opportunity, and (c) token reinforcement with a posttrial exchange opportunity. Within each condition, we assessed responding given (a) a no‐reinforcement baseline, (b) immediate reinforcement, and (c) delayed reinforcement, in which responses produced a reinforcer after 1 of 6 delays. Results suggest that delayed food produced greater response persistence than did delayed tokens.
Comparisons of synthesized and individual reinforcement contingencies during functional analysis
Authors: Fisher Wayne W. , Greer Brian D. , Romani Patrick W. , Zangrillo Amanda N. , Owen Todd M.
Published: May 2016

Researchers typically modify individual functional analysis (FA) conditions after results are inconclusive (Hanley, Iwata, & McCord, 2003). Hanley, Jin, Vanselow, and Hanratty (2014) introduced a marked departure from this practice, using an interview‐informed synthesized contingency analysis (IISCA). In the test condition, they delivered multiple contingencies simultaneously (e.g., attention and escape) after each occurrence of problem behavior; in the control condition, they delivered those same reinforcers noncontingently and continuously. In the current investigation, we compared the results of the IISCA with a more traditional FA in which we evaluated each putative reinforcer individually. Four of 5 participants displayed destructive behavior that was sensitive to the individual contingencies evaluated in the traditional FA. By contrast, none of the participants showed a response pattern consistent with the assumption of the IISCA. We discuss the implications of these findings on the development of accurate and efficient functional analyses.
Interview‐informed synthesized contingency analyses: Thirty replications and reanalysis
Authors: Jessel Joshua , Hanley Gregory P. , Ghaemmaghami Mahshid
Published: May 2016

The speed with which a functional analysis (FA) provides a convincing demonstration of the variables that influence problem behavior may be termed efficiency. Multiple FA formats have been developed to improve analytic efficiency while the core components of the Iwata, Dorsey, Slifer, Bauman, and Richman (1982/1994) procedures are maintained. We attempted to illustrate an alternative efficient process for conducting FAs of problem behavior that relied on modifying those core components. In Study 1, we describe 30 applications of the interview‐informed synthesized contingency analysis (Hanley, Jin, Vanselow, & Hanratty, 2014), which required an average of 25 min of analysis. The first sessions of these analyses were reanalyzed in Study 2 to determine if contingencies that controlled problem behavior could be identified in only 3 to 5 min. This was the case in 80% of analyses.
Zebrafish model of photochemical thrombosis for translational research and thrombolytic screening in vivo
Authors: Lee I‐Ju , Yang Yi‐Cyun , Hsu Jia‐Wen , Chang Wei‐Tien , Chuang Yung‐Jen , Liau Ian
Published: May 2016

Acute thromboembolic diseases remain the major global cause of death or disability. Although an array of thrombolytic and antithrombotic drugs has been approved to treat or prevent thromboembolic diseases, many more drugs that target specific clotting mechanisms are under development. Here a novel zebrafish model of photochemical thrombosis is reported and its prospective application for the screening and preclinical testing of thrombolytic agents in vivo is demonstrated. Through photochemical excitation, a thrombus was induced to form at a selected section of the dorsal aorta of larval zebrafish, which had been injected with photosensitizers. Such photochemical thrombosis can be consistently controlled to occlude partially or completely the targeted blood vessel. Detailed mechanistic tests indicate that the zebrafish model of photochemical thrombosis exhibits essential features of classical coagulation and a thrombolytic pathway. For demonstration, tissue plasminogen activator (tPA), a clinically feasible thrombolytic agent, was shown to effectively dissolve photochemically induced blood clots. In light of the numerous unique advantages of zebrafish as a model organism, our approach is expected to benefit not only the development of novel thrombolytic and antithrombotic strategies but also the fundamental or translational research targeting hereditary thrombotic or coagulation disorders.

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A novel nonviral gene delivery tool of BMP‐2 for the reconstitution of critical‐size bone defects in rats
Authors: Kolk Andreas , Tischer Thomas , Koch Christian , Vogt Stephan , Haller Bernhard , Smeets Ralf , Kreutzer Kilian , Plank Christian , Bissinger Oliver
Published: May 2016

The osseointegration of bone implants, implant failure, and the bridging of critical‐size bone defects are frequent clinical challenges. Deficiencies in endogenous bone healing can be resolved through the local administration of suitable recombinant growth factors (GFs). In preclinical models, gene‐therapy‐supported bone healing has proven promising for overcoming certain limitations of GFs. We report the dose‐dependent bridging of critical‐size mandibular bone defects (CSDs) in a rat model using a non‐viral BMP‐2‐encoding copolymer‐protected gene vector (pBMP‐2) embedded in poly(d, l‐lactide) (PDLLA) coatings on titanium discs that were used to cover drill holes in the mandibles of 53 male Sprague Dawley rats. After sacrificing, the mandibles were subjected to micro‐computed tomography (µCT), micro‐radiography, histology, and fluorescence analyses to evaluate bone regeneration. pBMP‐2 in PDLLA‐coated titanium implants promoted partial bridging of bone defects within 14 days and complete defect healing within 112 days when the DNA dose per implant did not exceed 2.5 µg. No bridging was observed in untreated control CSDs. Thus, the delivery of plasmid DNA coding for BMP‐2 appears to be a potent method for controlled new‐bone formation with an inverse dose dependency. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2441–2455, 2016.
Therapeutic plasma exchange performed in tandem with hemodialysis without supplemental calcium in the apheresis circuit
Authors: Zhao Yong , Ibrahim Hiba , Bailey Jeffrey A. , Linden Jeanne , Hickson Elda , Haynes Stefanie , Greene Mindy , Vauthrin Michelle , Weinstein Robert
Published: May 2016

Therapeutic plasma exchange (TPE) and hemopoietic progenitor cell (HPC) collection are apheresis procedures that can safely be performed in tandem with hemodialysis. Despite the return of citrate‐anticoagulated blood to the patient during HPC collection, it is not necessary to administer supplemental calcium during these procedures because the ionized calcium concentration is restored as the returning blood passes through the dialyzer. It is not known whether this applies to TPE, in which a mixture of blood and pharmaceutical albumin, an avid binder of plasma ionized calcium, is returned to the patient through the dialyzer. We report on three dialysis‐dependent patients who required TPE and underwent tandem treatments without supplemental calcium in the apheresis circuit. Overall, ionized calcium fell 4–12% (P = 0.0.024) and patients reported no symptoms of hypocalcemic toxicity. Tandem hemodialysis/TPE can be performed without supplemental calcium in the apheresis circuit. J. Clin. Apheresis 32:154–157, 2017. © 2016 Wiley Periodicals, Inc.
A Simple and Convenient Method for the Synthesis of 3,5‐disubstituted 1,2,4‐thiadiazoles via Oxidative Dimerization of Primary Thioamides
Authors: Subhas Bose D. , Raghavender Reddy K.
Published: May 2016

A simple and efficient protocol has been developed for the preparation of 3,5‐diaryl‐1,2,4‐thiadiazoles in high yields through the oxidative dimerization of primary thioamides in aqueous medium at room temperature.
Homogenization of scatterometer wind retrievals
Authors: Bentamy Abderrahim , Grodsky Semyon A. , Elyouncha Anis , Chapron Bertrand , Desbiolles Fabien
Published: May 2016

Surface winds (10 m equivalent neutral wind velocity) from scatterometer missions since 1992 to present require homogenization to meet the requirements for oceanic and atmospheric climate data records. Sources of differences between winds retrieved from different scatterometer measurements mainly arise from calibration/validation procedures used for each scatterometer and differences in measurement physics. In this study, we focus on the calibration/validation component of the European Remote Sensing Satellite (ERS)‐1 and ERS‐2 wind speed biases. ERS‐1 and ERS‐2 data, named as WNF products, are from the Institut Français de Recherche pour l'Exploitation de la MER (IFREMER). In addition to WNF data, the newly calibrated ERS‐2 products provided by the European Space Agency (ESA), indicated as ASPS2.0 products, are also used. Our approach utilizes collocated satellite‐buoy data. Expected values of the normalized radar cross section (NRCS) are calculated from buoy winds for each antenna beam using the Cmod5.n geophysical model function. The comparisons between expected and measured NRCS examine differences along with variables such as backscatter coefficient and incidence angle ranges. The difference between the expected and measured NRCS is then used to set up empirical models aiming at the correction for biases in ERS‐1 and ERS‐2 WNF NRCS calibrations. Finally, ERS‐1 and ERS‐2 wind retrievals are reprocessed using the corrected NRCS and Cmod5.n. These earlier corrected ERS‐1/2 winds are analysed along with later scatterometer data (QuikSCAT and ASCAT‐A) for their deviations from in situ buoy winds during 1992–2011 period. The scatterometer data homogeneity is also investigated at global scales based on the use of collocated scatterometer retrievals and atmospheric re‐analyses winds derived from ERA Interim and CFSR models.
Interdecadal increase of tropical cyclone genesis frequency over the western north Pacific in May
Authors: Huangfu Jingliang , Huang Ronghui , Chen Wen
Published: May 2016

The interdecadal changes in the frequency of tropical cyclone (TC) genesis in the western North Pacific (WNP) were examined for the epoch 1979–2013. There was an interdecadal increase in the frequency of TC genesis in the WNP in May during 1999–2013 than during 1979–1998, and such changes differed from those occurring between June and December. This interdecadal change is attributed to the early onset of the South China Sea summer monsoon (SCSSM) during 1999–2013, when the southwesterly winds spread eastwards and the monsoon trough (MT) moved into the WNP earlier. The MT favoured enhanced convection and anomalous low‐level cyclonic vorticity, facilitating more TC genesis. During 1979–1998, in contrast, the onset of the SCSSM was delayed and the MT was confined to the west of the South China Sea. As a result, weakened convection and anomalous anticyclonic low‐level vorticity are observed over the WNP, facilitating less TC genesis.
Vancomycin displays time‐dependent eradication of mature Staphylococcus aureus biofilms
Authors: Post Virginia , Wahl Peter , Richards R. Geoff , Moriarty T. Fintan
Published: May 2016

This study was carried out to determine the time and concentration profile required to achieve vancomycin‐mediated eradication of Staphylococcus aureus biofilm. This information is critical for the identification of performance targets for local antibiotic delivery vehicles that target biofilm infections. S. aureus UAMS‐1 biofilms were grown for 7 days on titanium–aluminium–niobium discs in Mueller Hinton broth. After 7 days, the discs were then incubated in Mueller Hinton broth containing vancomycin at concentrations of 100, 200, 500, 1,000, and 2,000 mg/L. Biofilm eradication was assessed under both static and shaking conditions. Samples were retrieved at regular intervals for up to 28 days for quantification of residual biofilm. One additional disc was processed per time point for scanning electron microscopy. Progressive and significant reduction of viable bacteria was observed over time at all concentrations compared to unexposed controls. After 28 days under static conditions, the S. aureus biofilm was completely eradicated at 200 mg/L vancomycin and higher concentrations, but not at 100 mg/L. In contrast, bacterial biofilm could not be eradicated under shaking conditions at any concentration.

Clinical significance: The present study shows that it is possible to eradicate mature S. aureus biofilm from metal implants by vancomycin alone although the time concentration profile required cannot be achieved by systemic administration or any of the local delivery vehicles currently available. Identifying targets for antibiotic delivery is the first step in developing fit for purpose local antibiotic delivery vehicles that will successfully and predictably treat established biofilm infection. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:381–388, 2017.
Diagnostic potential of multi‐targeted LAMP (loop‐mediated isothermal amplification) for osteoarticular tuberculosis
Authors: Sharma Kusum , Sharma Megha , Batra Nitya , Sharma Aman , Dhillon Mandeep Singh
Published: May 2016

Delay in diagnosing osteoarticular tuberculosis (OATB) contributes significantly to morbidity by causing disfiguration and neurological sequelae. The delay caused by conventional culture and the expertise and expense involved in other nucleic acid based tests, make LAMP (loop‐mediated isothermal amplification) assay a favorable middle path. We evaluated LAMP assay using IS6110 and MPB64 for rapid diagnosis of OATB by comparing with IS6110 PCR and culture. LAMP assay was performed on 140 synovial fluid and pus samples (10 culture‐positive proven cases, 80 culture‐negative probable cases, and 50 negative controls) using three set of primer pairs each for IS6110 and MPB64. LAMP assay, using two‐target approach, had an overall sensitivity and specificity of 90% and 100% in detecting OATB. Sensitivity of IS6110 PCR, IS6110 LAMP, and MPB64 LAMP was 80%, 100%, and 100%, respectively, for confirmed cases and 72.5%, 81.75%, and 86.25%, respectively, for probable cases. Six additional cases were picked using two‐target approach. LAMP assay utilizing IS6110 and MPB64 is a cost‐effective technique for an early and reliable diagnosis of OATB. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:361–365, 2017.
Intra‐articular dexamethasone to inhibit the development of post‐traumatic osteoarthritis
Authors: Grodzinsky Alan J. , Wang Yang , Kakar Sanjeev , Vrahas Mark S. , Evans Christopher H.
Published: May 2016

Injury to the joint provokes a number of local pathophysiological changes, including synthesis of inflammatory cytokines, death of chondrocytes, breakdown of the extra‐cellular matrix of cartilage, and reduced synthesis of matrix macromolecules. These processes combine to engender the subsequent development of post‐traumatic osteoarthritis (PTOA). To prevent this from happening, it is necessary to inhibit these disparate responses to injury; given their heterogeneity, this is challenging. However, dexamethasone has the necessary pleiotropic properties required of a drug for this purpose. Using in vitro models, we have shown that low doses of dexamethasone sustain the synthesis of cartilage proteoglycans while inhibiting their breakdown after injurious compression in the presence or absence of inflammatory cytokines. Under these conditions, dexamethasone is non‐toxic and maintains the viability of chondrocytes exposed chronically to such cytokines as interleukin (IL) ‐1, IL‐6, and tumor necrosis factor‐α. Moreover, the anti‐inflammatory properties of dexamethasone have been appreciated for decades. In view of this information, we have initiated a pilot clinical study to determine whether a single, intra‐articular injection of dexamethasone into the wrist shows promise in preventing PTOA after intra‐articular fracture of the distal radius.

CLINICAL SIGNIFICANCE: Suppressing the various etiopathophysiological responses to injury in the joint is an attractive strategy for lowering the clinical burden of PTOA. The intra‐articular administration of dexamethasone soon after injury offers a simple and inexpensive means of accomplishing this. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:406–411, 2017.
Antimicrobial activity of pomegranate peel extracts as affected by cultivar
Authors: Rosas‐Burgos Ema C , Burgos‐Hernández Armando , Noguera‐Artiaga Luis , Kačániová Miroslava , Hernández‐García Francisca , Cárdenas‐López José L , Carbonell‐Barrachina Ángel A
Published: May 2016

BACKGROUND

Some studies have reported that different parts of the pomegranate fruit, especially the peel, may act as potential antimicrobial agents and thus might be proposed as a safe natural alternative to synthetic antimicrobial agents. The high tannin content, especially punicalagin, found in pomegranate extracts, has been reported as the main compound responsible for such antimicrobial activity. Because the pomegranate peel chemical composition may vary with the type of cultivar (sweet, sour–sweet and sour), pomegranates may also differ with respect to their antimicrobial capacity.

RESULTS

The extract from PTO8 pomegranate cultivar peel had the highest antimicrobial activity, as well as the highest punicalagins (α and β) and ellagic acid concentrations. In the results obtained from both antibacterial and antifungal activity studies, the sour–sweet pomegranate cultivar PTO8 showed the best antimicrobial activity, and the highest ellagic acid concentrations.

CONCLUSION

The results of the present study suggest that ellagic acid content has a significant influence on the antimicrobial activity of the pomegranate extracts investigated. The pomegranate peel of the PTO8 cultivar is a good source of antifungal and antibacterial compounds, and may represent an alternative to antimicrobial agents of synthetic origin. © 2016 Society of Chemical Industry
Modeling the impact of selective harvesting on red deer antlers
Authors: Pozo Rocío A. , Schindler Susanne , Cubaynes Sarah , Cusack Jeremy J. , Coulson Tim , Malo Aurelio F.
Published: May 2016

Hunting is a common component in the management of ungulate species. Despite its widespread use, the influence of selective harvesting on phenotypic trait change is still ambiguous, and represents a critical gap in our understanding of the responses of wild populations under harvest. Using the long‐term red deer (Cervus elaphus) dataset (1972–2012) from the Isle of Rum National Nature Reserve, Scotland, we assessed the relationship between antler length and key demographic processes (i.e., survival, recruitment, antler growth, parent‐offspring trait correlation) for the male component of the population. We then constructed the first integral projection model for this species to examine the effects of simulated trophy hunting on 2 population‐level parameters: the stable antler size distribution and the relative reproductive value of males. When male mortality rates due to hunting were <20%, the effect on antler size distribution and the reproductive value function were relatively small. However, as mortality due to hunting increased to 50% in large individuals, the direct effects of hunting on mean antler size and reproductive value became evident. Our model acts as a useful starting point to investigate the ecological and evolutionary consequences of hunting in red deer. © 2016 The Wildlife Society.
Flame‐Retarded Epoxy Resins with a Curing Agent of DOPO‐Triazine Based Anhydride
Authors: Wirasaputra Alvianto , Yao Xiaohao , Zhu Yaming , Liu Shumei , Yuan Yanchao , Zhao Jianqing , Fu Yi
Published: May 2016

A 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO)‐triazine based anhydride (2,4,6‐tris‐(DOPO‐methylformatephthalic anhydride‐phenoxy)‐1,3,5‐triazine (TDA)) is synthesized and used as a halogen‐free flame retardant co‐curing agent for diglycidyl ether of bisphenol A/methylhexahydrophthalic anhydride (DGEBA/MHHPA) system. The conjugation of anhydride group is increased by the utilization of TDA, leading to the reduction in the curing activation energy. The cured epoxy resin passes V‐0 rating of UL 94 test with the limiting oxygen index of 32.7 vol% when the phosphorus content is only 1.5 wt%. The flame‐retarding action of triazine ring and DOPO moiety is investigated by the residue analysis and the characterization of pyrolysis gas. Due to the presence of bulky aromatic subunits in the molecular structure of TDA, the flame‐retarded epoxy resins maintain the high glass transition temperature of DGEBA/MHHPA. Besides, the moisture absorption is diminished following the usage of TDA.

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Broad Bandgap D–A Copolymer Based on Bithiazole Acceptor Unit for Application in High‐Performance Polymer Solar Cells with Lower Fullerene Content
Authors: Wang Kun , Guo Xia , Guo Bing , Li Wanbin , Zhang Maojie , Li Yongfang
Published: May 2016

A new broad bandgap and 2D‐conjugated D‐A copolymer, PBDTBTz‐T, based on bithienyl‐benzodithiophene donor unit and bithiazole (BTz) acceptor unit, is designed and synthesized for the application as donor material in polymer solar cells (PSCs). The polymer possesses highly coplanar and crystalline structure with a higher hole mobility and lower HOMO energy level which is beneficial to achieve higher open circuit voltage (Voc) of the PSCs with the polymer as donor. The PSCs based on PBDTBTz‐T:PC71BM blend film with a lower PC71BM content of 40% demonstrate a power conversion efficiency (PCE) of 6.09% with a relatively higher Voc of 0.92 V. These results indicate that the lower HOMO energy level of the BTz‐based D–A copolymer is beneficial to a high Voc of the PSCs. The polymer, with highly coplanar and crystalline structure, can effectively reduce the content of fullerene acceptor in the active layer and can enhance the absorption and PCE of the PSCs.

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1H and 13C NMR spectral assignment of N,N′‐disubstituted thiourea and urea derivatives active against nitric oxide synthase
Authors: Chayah Mariem , Camacho M. Encarnación , Carrión M. Dora , Gallo Miguel A.
Published: May 2016

The 1H and 13C NMR resonances of seventeen N‐alkyl and aryl‐N′‐[3‐hydroxy‐3‐(2‐nitro‐5‐substitutedphenyl)propyl]‐thioureas and ureas (1–17), and seventeen N‐alkyl or aryl‐N′‐[3‐(2‐amino‐5‐substitutedphenyl)‐3‐hydroxypropyl]‐thioureas and ureas (18–34), designed as NOS inhibitors, were assigned completely using the concerted application of one‐ and two‐dimensional experiments (DEPT, HSQC and HMBC). NOESY studies confirm the preferred conformation of these compounds. Copyright © 2016 John Wiley & Sons, Ltd.
Mapping of intracellular pH in the in vivo rodent heart using hyperpolarized [1‐13C]pyruvate
Authors: Lau Angus Z. , Miller Jack J. , Tyler Damian J.
Published: May 2016

Purpose

To demonstrate the feasibility of mapping intracellular pH within the in vivo rodent heart. Alterations in cardiac acid‐base balance can lead to acute contractile depression and alterations in Ca2+ signaling. The transient reduction in adenosine triphosphate (ATP) consumption and cardiac contractility may be initially beneficial; however, sustained pH changes can be maladaptive, leading to myocardial damage and electrical arrhythmias.

Methods

Spectrally selective radiofrequency (RF) pulses were used to excite the
and CO2 resonances individually while preserving signal from the injected hyperpolarized [1‐13C]pyruvate. The large flip angle pulses were placed within a three‐dimensional (3D) imaging acquisition, which exploited CA‐mediated label exchange between
and CO2. Images at 4.5 × 4.5 × 5 mm3 resolution were obtained in the in vivo rodent heart. The technique was evaluated in healthy rodents scanned at baseline and during high cardiac workload induced by dobutamine infusion.

Results

The intracellular pH was measured to be 7.15 ± 0.04 at baseline, and decreased to 6.90 ± 0.06 following 15 min of continuous β‐adrenergic stimulation.

Conclusions

Volumetric maps of intracellular pH can be obtained following an injection of hyperpolarized [1‐13C]pyruvate. The new method is anticipated to enable assessment of stress‐inducible ischemia and potential ventricular arrythmogenic substrates within the ischemic heart. Magn Reson Med 77:1810–1817, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Improving peak local SAR prediction in parallel transmit using in situ S‐matrix measurements
Authors: Restivo Matthew , Raaijmakers Alexander , van den Berg Cornelis , Luijten Peter , Hoogduin Hans
Published: May 2016

Purpose

Peak local specific absorption rate (pSAR10g) is an important parameter used to determine patient safety during radiofrequency transmission. pSAR10g predictions for parallel transmit MRI are affected by the level of coupling exhibited by a modeled array in the simulation environment. However, simulated array coupling is rarely equal to the physical array coupling. Accurately simulating the physical array coupling may improve the accuracy of predicted SAR levels.

Methods

The scattering parameter matrix (S‐matrix) of a prototype 4‐channel array was measured in situ using directional couplers installed on a 7T scanner. Agreement between the simulated and measured S‐matrix was achieved by using network co‐simulation with a modified cost function. B1+ maps acquired in a phantom were compared to B1+ distributions determined from simulations.

Results

The modified co‐simulation technique forces the simulations to have S‐matrices similar to the measured values. A comparison of realistically versus ideally simulated coupling conditions shows that ideally simulated coupling can result in large ( > 40%) error in pSAR10g predictions, even when the array is reasonably tuned. The simulated B1+ distributions match the measured B1+ distributions better when the coupling is accurately simulated.

Conclusion

Considering the measured array coupling matrix in numerical simulations eliminates a potential confound in pSAR10g prediction. Magn Reson Med 77:2040–2047, 2017. © 2016 International Society for Magnetic Resonance in Medicine
High quality three‐dimensional gagCEST imaging of in vivo human knee cartilage at 7 Tesla
Authors: Krishnamoorthy Guruprasad , Nanga Ravi Prakash Reddy , Bagga Puneet , Hariharan Hari , Reddy Ravinder
Published: May 2016

Purpose

To develop a new faster and higher quality three‐dimensional (3D) gagCEST MRI technique for reliable quantification of glycosaminoglycan (GAG) present in the human knee cartilages.

Methods

A new magnetization‐prepared 3D gradient echo‐based MRI pulse sequence has been designed to obtain the B0 inhomogeneity, B1 inhomogeneity, and CEST Z‐spectra images.

Results

The gagCEST values of different compartments of knee cartilage are calculated using a newly developed technique for healthy subjects and a symptomatic knee cartilage degenerated subject. The effect of the acquired CEST saturation frequency offset step‐size was investigated to establish the optimal step‐size to obtain reproducible gagCEST maps. Our novel 3D gagCEST technique demonstrates markedly higher gagCEST contrast value than the previously reported 3D gagCEST studies. This study demonstrates the need for separate B0 and B1 inhomogeneity estimation and correction.

Conclusion

The new technique provided high quality gagCEST maps with clearer visualization of different layers of knee cartilage with reproducible results. Magn Reson Med 77:1866–1873, 2017. © 2016 International Society for Magnetic Resonance in Medicine
Measuring the labeling efficiency of pseudocontinuous arterial spin labeling
Authors: Chen Zhensen , Zhang Xingxing , Yuan Chun , Zhao Xihai , van Osch Matthias J.P.
Published: May 2016

Purpose

Optimization and validation of a sequence for measuring the labeling efficiency of pseudocontinuous arterial spin labeling (pCASL) perfusion MRI.

Methods

The proposed sequence consists of a labeling module and a single slice Look‐Locker echo planar imaging readout. A model‐based algorithm was used to calculate labeling efficiency from the signal acquired from the main brain‐feeding arteries. Stability of the labeling efficiency measurement was evaluated with regard to the use of cardiac triggering, flow compensation and vein signal suppression. Accuracy of the measurement was assessed by comparing the measured labeling efficiency to mean brain pCASL signal intensity over a wide range of flip angles as applied in the pCASL labeling.

Results

Simulations show that the proposed algorithm can effectively calculate labeling efficiency when correcting for T1 relaxation of the blood spins. Use of cardiac triggering and vein signal suppression improved stability of the labeling efficiency measurement, while flow compensation resulted in little improvement. The measured labeling efficiency was found to be linearly (R = 0.973; P < 0.001) related to brain pCASL signal intensity over a wide range of pCASL flip angles.

Conclusion

The optimized labeling efficiency sequence provides robust artery‐specific labeling efficiency measurement within a short acquisition time (∼30 s), thereby enabling improved accuracy of pCASL CBF quantification. Magn Reson Med 77:1841–1852, 2017. © 2016 International Society for Magnetic Resonance in Medicine Magn Reson Med 77:1841–1852, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Integrated parallel reception, excitation, and shimming (iPRES) with multiple shim loops per radio‐frequency coil element for improved B0 shimming
Authors: Darnell Dean , Truong Trong‐Kha , Song Allen W.
Published: May 2016

Purpose

Integrated parallel reception, excitation, and shimming (iPRES) coil arrays allow radio‐frequency currents and direct currents to flow in the same coils, which enables excitation/reception and localized B0 shimming with a single coil array. The purpose of this work was to improve their shimming performance by adding the capability to shim higher‐order local B0 inhomogeneities that are smaller than the radio‐frequency coil elements.

Methods

A novel design was proposed in which each radio‐frequency/shim coil element is divided into multiple direct current loops, each using an independent direct current current, to increase the number of magnetic fields available for shimming while maintaining the signal‐to‐noise ratio of the coil. This new design is termed iPRES(N), where N represents the number of direct current loops per radio‐frequency coil element. Proof‐of‐concept phantom and human experiments were performed with an 8‐channel body coil array to demonstrate its advantages over the original iPRES(1) design.

Results

The average B0 homogeneity in various organs before shimming and after shimming with the iPRES(1) or iPRES(3) coil arrays was 0.24, 0.11, and 0.05 ppm, respectively. iPRES(3) thus reduced the B0 inhomogeneity by 53% and further reduced distortions in echo‐planar images of the abdomen when compared with iPRES(1).

Conclusion

iPRES(N) can correct for localized B0 inhomogeneities more effectively than iPRES(1) with no signal‐to‐noise ratio loss, resulting in a significant improvement in image quality. Magn Reson Med 77:2077–2086, 2017. © 2016 International Society for Magnetic Resonance in Medicine
Resilient Coping Moderates the Effect of Trauma Exposure on Depression
Authors: Sinclair Vaughn G. , Wallston Kenneth A. , Strachan Eric
Published: May 2016

Posttraumatic depression rates are increasing in the United States, and there is a great need to identify malleable factors that could moderate posttraumatic depression levels. The purpose of this study was to examine whether resilient coping moderates the effects of trauma exposure on depression, while controlling for neuroticism—an established predictor of depressive symptoms. This study used data from 3,734 pairs of twins from the community‐based University of Washington Twin Registry. Each twin pair was randomized with twin A in one subsample and twin B in the second subsample. The four‐item Brief Resilient Coping Scale measured resilient coping. The two‐item Patient Health Questionnaire measured depression. Multiple linear regression analyses were performed on each subsample, controlling for neuroticism. In addition to significant effects of neuroticism and trauma exposure on depression (p < .001), the effect of the interaction of resilient coping and trauma exposure on depression was significant in both subsamples (p < .01). High levels of resilient coping were associated with lower depression scores in the context of previous trauma exposure. Individuals high in resilient coping who experienced significant life traumas were less depressed after trauma exposure, even after controlling for neuroticism. Because coping skills may be learned, interventions that teach resilient coping to individuals with traumatic histories merit investigation. © 2016 Wiley Periodicals, Inc.
Handling Missing Data With Multilevel Structural Equation Modeling and Full Information Maximum Likelihood Techniques
Authors: Schminkey Donna L. , von Oertzen Timo , Bullock Linda
Published: May 2016

With increasing access to population‐based data and electronic health records for secondary analysis, missing data are common. In the social and behavioral sciences, missing data frequently are handled with multiple imputation methods or full information maximum likelihood (FIML) techniques, but healthcare researchers have not embraced these methodologies to the same extent and more often use either traditional imputation techniques or complete case analysis, which can compromise power and introduce unintended bias. This article is a review of options for handling missing data, concluding with a case study demonstrating the utility of multilevel structural equation modeling using full information maximum likelihood (MSEM with FIML) to handle large amounts of missing data. MSEM with FIML is a parsimonious and hypothesis‐driven strategy to cope with large amounts of missing data without compromising power or introducing bias. This technique is relevant for nurse researchers faced with ever‐increasing amounts of electronic data and decreasing research budgets. © 2016 Wiley Periodicals, Inc.
Beliefs About Dysmenorrhea and Their Relationship to Self‐Management
Authors: Chen Chen X. , Kwekkeboom Kristine L. , Ward Sandra E.
Published: May 2016

Dysmenorrhea is highly prevalent and is the leading cause of work and school absences among women of reproductive age. However, self‐management of dysmenorrhea is not well understood in the US, and little evidence is available on factors that influence dysmenorrhea self‐management. Guided by the Common Sense Model, we examined women's representations of dysmenorrhea (beliefs about causes, symptoms, consequences, timeline, controllability, coherence, and emotional responses), described their dysmenorrhea self‐management behaviors, and investigated the relationship between representations and self‐management behaviors. We conducted a cross‐sectional, web‐based survey of 762 adult women who had dysmenorrhea symptoms in the last six months. Participants had varied beliefs about the causes of their dysmenorrhea symptoms, which were perceived as a normal part of life. Dysmenorrhea symptoms were reported as moderately severe, with consequences that moderately affected daily life. Women believed they understood their symptoms moderately well and perceived them as moderately controllable but them to continue through menopause. Most women did not seek professional care but rather used a variety of pharmacologic and complementary health approaches. Care‐seeking and use of self‐management strategies were associated with common sense beliefs about dysmenorrhea cause, consequences, timeline, and controllability. The findings may inform development and testing of self‐management interventions that address dysmenorrhea representations and facilitate evidence‐based management. © 2016 Wiley Periodicals, Inc.
Low frequency accelerator sensor based on piezoelectric ZnO nanorods grown by low temperature scalable process
Authors: Nour Eiman Satti , Chey Chan Oeurn , Willander Magnus , Nur Omer
Published: May 2016

Piezoelectric vertically aligned zinc oxide (ZnO) nanorods (NRs) were grown by low temperature aqueous chemical approach and successfully used as a low frequency self‐powered accelerator detector system. The nanogenerator (NG) device was tested under the influence of low frequency vibrations, different load masses, and finger prints pressure. The experimental results show relatively high sensitivity to frequencies as low as 5 Hz. This energy conversion device has produced a maximum output voltage of about 0.3 and 1.4 V under a frequency of 41 Hz and a mass of 1000 g, respectively. The fabricated NG can be used as an accelerator sensor with a good performance in the range from about 0.67 to 5.5 m s−2 with a sensitivity of 0.045 V s2 m−1. Furthermore, it has been demonstrated that the NG is able to harvest energy under finger‐print scanning. The result from the finger‐print pressure was consistent with the masses testing results. This energy‐harvesting technology also provides a simple and cost‐effective platform to capture low‐frequency mechanical energy, i.e., body movements, and other applications like developing a sensitive finger print camera, etc.
Comparison between Si/SiO2 mid‐gap interface states and deep levels associated with silicon‐oxygen superlattices in p‐type silicon
Authors: Simoen Eddy , Jayachandran S. , Delabie A. , Caymax M. , Heyns M.
Published: May 2016

In this paper, the deep levels found by deep‐level transient spectroscopy in Si‐O superlattices on p‐type silicon substrates are compared with the band of near mid‐gap hole traps typically observed at the Si/SiO2 interface. In addition, the impact of a post‐deposition Forming Gas Annealing is investigated. A large similarity between the two material systems is reported, which indicates that similar silicon‐oxygen bonds may be responsible for the deep hole traps.(© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)