bluuebunny/crossref_metadata_2025 huggingface dataset:
A simple solid‐phase extraction method for the analysis of red cell phospholipids by liquid chromatography‐ tandem mass spectrometry
Authors: Nguyen Van Long
Published: February 2018

Background

There has been increasing interest in the analysis of phospholipids in red blood cells as potential long‐term biomarkers of different disease states. Here, we describe a simple method for the analysis of two phospholipids: 1‐Palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphoethanol (PE 16:0/18:1) and 1‐Palmitoyl‐2‐linoleoyl‐sn‐glycero‐3‐phosphoethanol (PE 16:/0/18:2) in erythrocytes by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS).

Methods

Whole blood samples were removed free of plasma and washed in isotonic saline. Red cells were lysed with ultrapure water. Lysate samples were processed using a hybrid solid‐phase extraction (SPE) phospholipid cartridge (1 mL, 30 mg). Both PE 16:0/18:1 and PE 16:0/18:2 and their deuterated internal standards were separated on an ACE C4 (150 mm × 2.1 mm, 2.7 μm particle size) by gradient elution at a flow rate of 0.5 mL per minute using mobile phases consisting of 0.01 mol/L ammonium acetate in: water (A), methanol (B), and isopropanol (C). The phospholipid species were quantified by the following transitions: PE 16:0/18:1: 701.5→281.3 and PE 16:0/18:2: 699.5→279.3.

Results

Both PE species displayed linearity ranging from 10 to 500 μg/L. The coefficient of variation (CV%) of PE 16:0/18:1 concerning intraday and interday precision was between 1.9%‐2.6% and 3.0%‐4.3%, respectively. For PE 16:0/18:2, this was between 1.8%‐3.4% and 3.7%‐4.1%, respectively. Both phospholipid species had accuracy (PE 16:0/18:1: 91%‐98% and PE 16:0/18:2: 94%‐103%) and extraction recovery (PE 16:0/18:1: 95%‐106% and PE 16:0/18:2: 92%‐102%) exceeding 90% over the analytical range. The limit of detection was 5 μg/L.

Conclusion

Here we propose a simple SPE LC‐MS/MS method for analyzing phospholipids in erythrocytes, which can be easily adopted.
Feasible microbial accumulation of triacylglycerides from crude glycerol
Authors: Fra‐Vázquez Andrea , Pedrouso Alba , Palmeiro‐Sánchez Tania , Moralejo‐Gárate Helena , Mosquera‐Corral Anuska
Published: February 2018

BACKGROUND

Crude glycerol, a by‐product of the biodiesel production industry, was used to produce intracellular storage polymers for waste valorization. The enrichment of a mixed microbial culture (MMC) in microorganisms with the ability to accumulate intracellular polymers was performed in a sequencing batch reactor (SBR) submitted to feast–famine conditions. The effect of different carbon sources in the accumulation of biopolymers was investigated.

RESULTS

A MMC enriched in yeast and bacteria was obtained using crude glycerol as feedstock. Accumulation experiments performed with crude glycerol, synthetic glycerol and synthetic methanol showed the feasibility of the MMC to produce different biopolymers. Triacylglyceride (TAG) accumulation up to 46 wt% in yeast cells was promoted by the presence of residual lipids in crude glycerol. However, bacteria from class Betaproteobacteria used glycerol mainly to accumulate 28 wt% of polyglucose (PG) and methanol as carbon source for cell growth.

CONCLUSIONS

As waste valorization, a possible advantage which comes out of the present study is the use of open, non‐sterile and non‐defined systems to produce TAGs. These TAGs can potentially re‐enter the biodiesel production process helping on the maximisation of the feedstock used in this process. © 2018 Society of Chemical Industry
Retention and mortality on antiretroviral therapy in sub‐Saharan Africa: collaborative analyses of HIV treatment programmes
Authors: Haas Andreas D , Zaniewski Elizabeth , Anderegg Nanina , Ford Nathan , Fox Matthew P , Vinikoor Michael , Dabis François , Nash Denis , Sinayobye Jean d'Amour , Niyongabo Thêodore , Tanon Aristophane , Poda Armel , Adedimeji Adebola A , Edmonds Andrew , Davies Mary‐Ann , Egger Matthias ,   the African regions of the International epidemiologic Databases to Evaluate AIDS (IeDEA)
Published: February 2018

Introduction

By 2020, 90% of all people diagnosed with HIV should receive long‐term combination antiretroviral therapy (ART). In sub‐Saharan Africa, this target is threatened by loss to follow‐up in ART programmes. The proportion of people retained on ART long‐term cannot be easily determined, because individuals classified as lost to follow‐up, may have self‐transferred to another HIV treatment programme, or may have died. We describe retention on ART in sub‐Saharan Africa, first based on observed data as recorded in the clinic databases, and second adjusted for undocumented deaths and self‐transfers.

Methods

We analysed data from HIV‐infected adults and children initiating ART between 2009 and 2014 at a sub‐Saharan African HIV treatment programme participating in the International epidemiology Databases to Evaluate AIDS (IeDEA). We used the Kaplan–Meier method to calculate the cumulative incidence of retention on ART and the Aalen–Johansen method to calculate the cumulative incidences of death, loss to follow‐up, and stopping ART. We used inverse probability weighting to adjust clinic data for undocumented mortality and self‐transfer, based on estimates from a recent systematic review and meta‐analysis.

Results

We included 505,634 patients: 12,848 (2.5%) from Central Africa, 109,233 (21.6%) from East Africa, 347,343 (68.7%) from Southern Africa and 36,210 (7.2%) from West Africa. In crude analyses of observed clinic data, 52.1% of patients were retained on ART, 41.8% were lost to follow‐up and 6.0% had died 5 years after ART initiation. After accounting for undocumented deaths and self‐transfers, we estimated that 66.6% of patients were retained on ART, 18.8% had stopped ART and 14.7% had died at 5 years.

Conclusions

Improving long‐term retention on ART will be crucial to attaining the 90% on ART target. Naïve analyses of HIV cohort studies, which do not account for undocumented mortality and self‐transfer of patients, may severely underestimate both mortality and retention on ART.
MRI‐based measurements of whole‐brain global cerebral blood flow: Comparison and validation at 1.5T and 3T
Authors: Chen Chun‐Ming , Huang Yen‐Chih , Shih Cheng‐Ting , Chen Yung‐Fang , Peng Shin‐Lei
Published: February 2018

Background

Whole‐brain global cerebral blood flow (CBF) determined by MRI techniques, calculated using total CBF (TCBF) from phase‐contrast MRI (PC‐MRI), and brain parenchyma volume (BPV) from T1‐weighted image, have become increasingly popular in many applications.

Purpose/Hypothesis

To determine if MRI‐based measurements of whole‐brain global CBF data obtained across different field strengths could be merged, TCBF and BPV data acquired at 1.5T and 3T were compared.

Study Type

Prospective study.

Population

Seventeen healthy subjects (eight females, aged 21–29 years old).

Field Strength/Sequence

Fast spoiled gradient echo (FSPGR) and PC‐MRI at both 1.5T and 3T.

Assessment

TCBF and BPV data acquired at 1.5T and 3T were compared.

Statistical Tests

The relationships of TCBF and whole‐brain global CBF between two field strengths were examined by using the Pearson correlation coefficient analysis and intraclass correlation coefficient (ICC).

Results

Regression analysis revealed a strong correlation between TCBF at two field strengths (R2 = 0.78, P < 0.001), and the ICC was 0.85, suggesting measurements of TCBF at 1.5T were comparable and correlated with those at 3T. There was a significant difference in BPV between field strengths, where the white matter estimate was significantly larger at 1.5T when compared with that at 3T (P < 0.001). When TCBF was further normalized to the brain parenchyma mass to obtain whole‐brain global CBF, it only showed a moderate correlation between measurements at the two field strengths (R2 = 0.46, P = 0.003) and lower ICC of 0.66, reflecting the slightly higher interstrength variability in the whole‐brain global CBF measurements.

Data Conclusion

TCBF measurements could be performed equally well with comparable results at both field strengths, but specific attention should be given when TCBF is further normalized to BPV to obtain whole‐brain global CBF.

Level of Evidence: 1

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2018;47:1273–1280.
Evaluating a preventive biological control agent applied on grapevines against Botrytis cinerea and its influence on winemaking
Authors: Escribano‐Viana Rocío , Portu Javier , Garijo Patrocinio , Gutiérrez Ana Rosa , Santamaría Pilar , López‐Alfaro Isabel , López Rosa , González‐Arenzana Lucía
Published: February 2018

BACKGROUND

This research was aimed to study the influence on grape and wine quality and on the fermentation processes of the application of a preventive biological treatment against Botrytis cinerea in Tempranillo Rioja grapevines. For this purpose, a biofungicide containing Bacillus subtilis QST713 was applied twice to the vineyard.

RESULTS

Results were compared with non‐treated samples from the same vineyard and with samples treated with a chemical fungicide composed of fenhexamid. Data showed that general grape quality and spontaneous alcoholic fermentation performance were not influenced by either fungicide application. The chemical fungicide had a considerable influence on the clonal diversity of Saccharomyces cerevisiae species, which led to the alcoholic fermentation. Furthermore, it caused longer malolactic fermentation than with the biological fungicide and in the control. The biofungicide made malolactic fermentation 1 day shorter because the establishment of the commercial lactic acid bacteria used as a starter culture was total. After malolactic fermentation, the wines did not show significant differences in general oenological parameters.

CONCLUSION

Preventive biofungicide treatment against B. cinerea did not negatively influence the quality of grapes and wines and the fermentation processes. Therefore, biological control of B. cinerea with B. subtilis applied on grapevines could be advisable in oenological terms. © 2018 Society of Chemical Industry
Applying nitrogen fertilizer increased anthocyanin in vegetative shoots but not in grain of purple rice genotypes
Authors: Yamuangmorn Supaporn , Dell Bernard , Rerkasem Benjavan , Prom‐u‐thai Chanakan
Published: February 2018

BACKGROUND

Anthocyanin is a major antioxidant compound in purple rice, with properties that can protect against oxidative damage in some human diseases. This study was undertaken to determine if nitrogen (N) fertilizer can enhance anthocyanin and antioxidant levels in four purple Thai rice genotypes.

RESULTS

The anthocyanin concentration and antioxidant capacity were increased in the shoots of N120 plants compared with plants without N. The leaves had higher anthocyanin concentration and antioxidant capacity than the stem+leaf sheath. Maximum shoot anthocyanin concentrations occurred at tillering and then declined by 87–94% at maturity. Antioxidant capacity was high at tillering and panicle initiation and declined by 26% in leaves and by 98% in the stem+leaf sheath at maturity. Unlike in the vegetative shoot, grain anthocyanin was not affected by the addition of N fertilizer. The response of grain antioxidant capacity to N fertilizer was affected by genotype, increasing in KPY by 45% but decreasing in K19959 by 30% in N120 plants.

CONCLUSION

Applying N fertilizer could be a promising way to improve the antioxidative properties in vegetative parts for use in rice‐grass juice, cosmetics and other products, especially the young leaves, which contained high values of anthocyanin as well as antioxidant capacity. However, further field studies should be undertaken to optimize N utilization for anthocyanin and antioxidant capacity in purple rice genotypes. © 2018 Society of Chemical Industry
Factors associated with benefit of active middle ear implants compared to conventional hearing aids
Authors: McRackan Theodore R. , Clinkscales William B. , Ahlstrom Jayne B. , Nguyen Shaun A. , Dubno Judy R.
Published: February 2018

Objective

Identify factors associated with benefit of middle ear implants (MEIs) as compared to conventional hearing aids (HAs).

Study Design

Independent review of audiological data from a multicenter prospective U.S. Food and Drug Administration (FDA) clinical trial. Preoperative and postoperative earphone, unaided/aided/implanted pure‐tone thresholds, and word recognition scores were evaluated.

Results

Ninety‐one subjects were included in this study. Mean word recognition was better with MEIs than with HAs (81.8% ± 12.0% vs. 77.6% ± 14.6%, P = 0.035). Word recognition with MEIs showed a low positive correlation with word recognition measured with earphones (r = 0.25, P = 0.016) and a moderate positive correlation with aided word recognition (r = 0.42, P < 0.001). Earphone word recognition alone was not predictive of MEI benefit over HA benefit (r = 0.09, P = 0.41), unlike differences between scores with earphone and HAs (earphone‐aided differences [EAD]) (r = 0.62, P < 0.011). As compared to those with –EADs, subjects with +EADs showed greater improvement in word recognition from unaided to implanted and from HAs to implanted (P < 0.0001). Using the 95% CI for word recognition scores, 16 subjects showed significantly higher scores with the MEI than with HAs. Of those, 14 had +EAD.

Conclusion

Word recognition benefit derived from conventional HAs and MEIs from this large, multi‐center FDA trial provides further evidence of the importance of aided word recognition in clinical decision making, such as determining candidacy for and success with MEIs.

Level of Evidence

2b. Laryngoscope, 128:2133–2138, 2018
Patterns of concurrent cigarette, alcohol, and e‐cigarette use: Off‐setting or additive behaviors?
Authors: Parikh Anuraag S. , Bhattacharyya Neil
Published: February 2018

Objectives

To understand nationwide concurrent use of e‐cigarettes (Ecig) with alcohol and conventional cigarettes (Ccig), the major risk factors for head and neck cancer.

Study Design

Cross‐sectional analysis of nationally representative survey.

Methods

The National Health Interview Surveys for 2014 and 2015 were analyzed for adult responses to specific questions regarding the daily frequency of alcohol, Ccig, and Ecig use. Statistical relationships between these social habits were determined.

Results

A total of 241.1 million adults (raw N = 162,048) were surveyed (mean age 47.1 years, 51.8% female). Of those, 12.1% (29.2 million) and 3.8% (9.08 million) reported being every day Ccig users and some days Ccig users, respectively. A total of 2.3% (5.63 million) and 1.1% (2.76 million) reported being every day Ecig users and some days Ecig users, respectively. In addition, 58.4% of everyday Ecig users reported also being everyday Ccig users (P < 0.001). Furthermore, 25.6% (61.3 million) and 8.3% (20.0 million) of adults reported light drinking (1–3 drinks/week) and moderate/heavy drinking (4–7 drinks/week), respectively. Of the moderate/heavy drinkers, 17.7% were everyday Ccig users, whereas 12.2% of everyday Ccig users were moderate/heavy drinkers (P < 0.001). Among everyday Ecig users, 34.6% and 11.2% were light drinkers and moderate/heavy drinkers, respectively (P < 0.001). Among non‐Ccig users, everyday Ecig users were likely to consume higher levels of alcohol given that 36.5% and 8.9% were light drinkers and moderate/heavy drinkers, respectively (P < 0.01).

Conclusion

We demonstrate a substantial level of Ccig use among moderate/heavy drinkers and Ecig users, as well as a novel independent association between Ecig and moderate/heavy alcohol use. These patterns of concurrent risk factor exposure should be considered when counseling patients who report Ecig use.

Level of Evidence

2b. Laryngoscope, 1817–1821, 2018
Utility of the bow and lean test in predicting subtype of benign paroxysmal positional vertigo
Authors: Choi Seongjun , Choi Hye Rang , Nahm Hyunjoo , Han Kyujin , Shin Jung Eun , Kim Chang‐Hee
Published: February 2018

Objectives/Hypothesis

To investigate the role of the bow and lean test (BLT) in the diagnosis of benign paroxysmal positional vertigo (BPPV).

Study Design

Retrospective case‐control study.

Methods

Between March 2015 and June 2017, we enrolled 113 patients with posterior semicircular canal (PSCC) BPPV, 74 patients with lateral semicircular canal (LSCC) canalolithiasis, 53 patients with LSCC cupulolithiasis, and 32 patients with light cupula. We retrospectively assessed bowing nystagmus (BN) and leaning nystagmus (LN).

Results

In PSCC BPPV, 75% of the patients showed at least one of BN and LN, and direction of nystagmus provoked by a Dix‐Hallpike test on the affected side was consistent with that of LN and opposite to that of BN. In LSCC canalolithiasis, 65% (48 of 74) of the patients showed both BN and LN, which were in the same direction in 38 patients (of 48) and in the opposite direction in 10 patients (of 48). The affected side can be determined according to the results of THE BLT in 74% (55 of 74) of LSCC canalolithiasis patients, and among them, the side determined according to the results of head‐roll test was discordant with that according to the BLT in 20 of 55 patients (36%). In LSCC cupulopathy (n = 85), both BN and LN were persistent and observed in all cases, but we could not distinguish LSCC cupulolithiasis from light cupula according to nystagmus direction in the BLT.

Conclusions

Although a BLT yields better lateralization in LSCC canalolithiasis, it may be more useful in predicting the diagnosis and lateralization of PSCC BPPV than LSCC canalolithiasis.

Level of Evidence

4 Laryngoscope, 2600–2604, 2018
Continuous vagal monitoring value in prevention of vocal cord paralysis following thyroid surgery
Authors: Kandil Emad , Mohsin Khuzema , Murcy Mohammad A. , Randolph Gregory W.
Published: February 2018

Objectives/Hypothesis

Continuous intraoperative neuromonitoring (CIONM) of the vagus nerve was proposed to obtained frequent repetitive electromyography (EMG) data to recognize early change in intraoperative function of the recurrent laryngeal nerve. We examine our initial experience using this technology.

Study Design

Retrospective review.

Methods

Data for all patients who underwent neck surgery by a single surgeon at a North American institution over a 5‐year period were reviewed. CIONM was used in cases with possible higher risk of traction injury and according to surgeon preference. In these cases, stretch injury was established by warning alarm with threshold of ≥50% reduction in amplitude and/or ≥ 10% increase in latency. Preoperative and postoperative direct laryngoscopy was performed for all patients.

Results

A total of 879 endocrine neck surgeries were performed. CIONM was used to monitor 455 recurrent laryngeal nerves (RLNs) in 344 (39.1%) surgeries. An automatic periodic stimulation (APS) alarm detected impending nerve injury in 33 (9.6%) cases by 64.9% ± 12.7% decrease in amplitude and by 27.3% increase in latency in one case. A total loss of signal (LOS) was detected in 15 (4.36%) cases. The immediate release of causative retraction successfully preserved the nerves in all cases with impending injury; however, there was no improvement in the LOS cases. Other than the cases with LOS, postoperative laryngoscopy showed normal vocal cord function in all cases.

Conclusions

APS technology is safe, feasible, and helpful in approximately 10% of cases in our series, which developed nascent neurapraxia adverse EMG changes associated with intraoperative RLN stretch that could be reversed intraoperatively.

Level of Evidence

4. Laryngoscope, 128:2429–2432, 2018
Decreasing Revision Surgery in FAMM Flap Reconstruction of the Oral Cavity: Traditional Versus Modified Harvesting Technique
Authors: Ibrahim Badr , Rahal Akram , Bissada Eric , Christopoulos Apostolos , Moubayed Sami P. , Guertin Louis , Tabet Jean‐Claude , Olivier Marie‐Jo , Ayad Tareck
Published: February 2018

Objective

To compare the surgical and functional outcomes between two harvesting techniques for the inferiorly based facial artery musculomucosal (FAMM) flap for oral cavity and oropharynx reconstructions.

Methods

Multicenter retrospective chart review.

Results

We reviewed 55 cases of FAMM flap, including 29 traditional cases and 26 performed using the modified harvesting method. The overall rate of surgical re‐intervention in the traditional group was 31% (n = 9 of 29) and 15% (n = 4 of 26) in the modified group (P = 0.196). The specific re‐intervention rate for pedicle sectioning was 27% (n = 8 of 29) in the traditional group versus 0% (n = 0 of 26) in the modified group. The overall rate of complications was 21%. Nine out of 10 dentate patients in the traditional group and four out of five in the modified group needed tooth extraction. There was no difference between the two groups in terms of tracheostomy duration (P = 0.338) and time to first oral intake (P = 0.629). Speech and feeding outcomes were similar among groups (P = 0.922; P = 0.700, respectively). Dental rehabilitation was achieved in 67% and 78% of patients in the traditional and modified groups, respectively.

Conclusion

The FAMM flap offers a low morbidity approach to reconstruct the oral cavity. The modified approach to harvesting the flap is a safe and effective technique, with similar functional results and equally low morbidity profile as the traditional technique. It has the added advantage of lower rates of secondary surgical interventions.

Level of Evidence

4. Laryngoscope, 1802–1805, 2018
The impact of adjuvant chemoradiotherapy timing on survival of head and neck cancers
Authors: Tam Moses , Wu S. Peter , Gerber Naamit K. , Lee Anna , Schreiber David , Givi Babak , Hu Kenneth
Published: February 2018

Background

Delays in postoperative head and neck (HN) radiotherapy have been associated with decreased overall survival; however, the impact of delays in postoperative HN chemoradiotherapy remains undefined.

Methods

All patients with nonmetastatic HN cancer (oral cavity, oropharynx, larynx, hypopharynx) who underwent curative intent surgery and received adjuvant chemoradiotherapy were identified from the National Cancer Database (2005–2012). Overall treatment time (OTT) was defined as the time from surgery to the end of radiation therapy. Statistical methods included Cox proportional hazards modeling, which adjusted for clinicopathologic, demographic, and socioeconomic factors. Recursive partitioning analysis (RPA) identified the optimal threshold of OTT via conditional inference trees to estimate the greatest differences in overall survival (OS) on the basis of randomly selected training and validation sets.

Results

A total of 16,733 patients were included, with a median follow‐up of 37 months. Median OS for OTT in a predefined threshold of ≤ 13 weeks was 10.1 years (95% confidence interval [CI], 9.8 years; not reached) compared with 8.7 years (95% CI, 8.2–9.2 years) in > 13 weeks. On multivariate analysis, OTT of > 13 weeks versus ≤ 13 weeks independently increased mortality risk (hazard ratio, 1.10; 95% CI, 1.04–1.17; P = < 0.001). RPA identified an optimal OTT threshold of 97 days (interquartile range: 96–98 days). The OTT threshold of 97 days was confirmed in a full Cox regression model estimating the risk of death according to overall treatment time as a continuous variable.

Conclusion

In this large hospital‐based national data, an OTT of greater than approximately 14 weeks most consistently increased the risk of death.

Level of Evidence

4. Laryngoscope, 128:2326–2332, 2018
Spreading the digital word: ISI’s Electronic Library Project
Authors: Czech Isabel
Published: February 2018

Describes the process behind – and the progress of – a unique project designed to explore many of the technical and economic issues pertaining to the implementation and use of an electronic library.
Porous Vesicles with Extrusion‐Tunable Permeability and Pore Size from Mixed Solutions of PEO–PPO–PEO Triblock Copolymers
Authors: Schantz A. Benjamin , Ren Tingwei , Pachalla Abhishek , Shen Yuexiao , Hickey Robert J. , Kumar Manish
Published: February 2018

Block copolymer (BC) vesicles in aqueous solution can encapsulate hydrophilic molecules or nanoparticles for drug and gene delivery, enhanced imaging, microreactors, or sensors. Inexpensive, biocompatible poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO) triblock copolymers (TBCs) would be ideal for these applications if they could form concentrated vesicle solutions to encapsulate such molecules with high efficiency. It is shown that solutions of two PEO–PPO–PEO TBCs (EO5–PO68–EO5 and EO100–PO65–EO100) form vesicles, that the vesicle membranes are permeable to low‐molecular weight (MW) solutes, and that extrusion reduces the membrane permeability and MW cutoff. Osmotic permeabilities before and after extrusion are ≈1000 and ≈10 µm s−1, respectively, while the MW cutoffs for solute rejection are ≈1000 and ≈400 g mol−1. Therefore, it is hypothesized that the vesicles contain pores, and that extrusion reduces the pores' size and the membrane's porosity. These selectively permeable vesicles can function as microreactors or sensors encapsulating large solutes without the need to add channel molecules or proteins.
Geant4‐DNA track‐structure simulations for gold nanoparticles: The importance of electron discrete models in nanometer volumes
Authors: Sakata Dousatsu , Kyriakou Ioanna , Okada Shogo , Tran Hoang N. , Lampe Nathanael , Guatelli Susanna , Bordage Marie‐Claude , Ivanchenko Vladimir , Murakami Koichi , Sasaki Takashi , Emfietzoglou Dimitris , Incerti Sebastien
Published: February 2018

Purpose

Gold nanoparticles (GNPs) are known to enhance the absorbed dose in their vicinity following photon‐based irradiation. To investigate the therapeutic effectiveness of GNPs, previous Monte Carlo simulation studies have explored GNP dose enhancement using mostly condensed‐history models. However, in general, such models are suitable for macroscopic volumes and for electron energies above a few hundred electron volts. We have recently developed, for the Geant4‐DNA extension of the Geant4 Monte Carlo simulation toolkit, discrete physics models for electron transport in gold which include the description of the full atomic de‐excitation cascade. These models allow event‐by‐event simulation of electron tracks in gold down to 10 eV. The present work describes how such specialized physics models impact simulation‐based studies on GNP‐radioenhancement in a context of x‐ray radiotherapy.

Methods

The new discrete physics models are compared to the Geant4 Penelope and Livermore condensed‐history models, which are being widely used for simulation‐based NP radioenhancement studies. An ad hoc Geant4 simulation application has been developed to calculate the absorbed dose in liquid water around a GNP and its radioenhancement, caused by secondary particles emitted from the GNP itself, when irradiated with a monoenergetic electron beam. The effect of the new physics models is also quantified in the calculation of secondary particle spectra, when originating in the GNP and when exiting from it.

Results

The new physics models show similar backscattering coefficients with the existing Geant4 Livermore and Penelope models in large volumes for 100 keV incident electrons. However, in submicron sized volumes, only the discrete models describe the high backscattering that should still be present around GNPs at these length scales. Sizeable differences (mostly above a factor of 2) are also found in the radial distribution of absorbed dose and secondary particles between the new and the existing Geant4 models. The degree to which these differences are due to intrinsic limitations of the condensed‐history models or to differences in the underling scattering cross sections requires further investigation.

Conclusions

Improved physics models for gold are necessary to better model the impact of GNPs in radiotherapy via Monte Carlo simulations. We implemented discrete electron transport models for gold in Geant4 that is applicable down to 10 eV including the modeling of the full de‐excitation cascade. It is demonstrated that the new model has a significant positive impact on particle transport simulations in gold volumes with submicron dimensions compared to the existing Livermore and Penelope condensed‐history models of Geant4.
Technical Note: A planning technique to lower normal tissue toxicity in lung SBRT plans based on two likely dependent RTOG metrics
Authors: Narayanasamy Ganesh , Desai Dharmin , Morrill Steven , Zhang Xin , Galhardo Edvaldo , Maraboyina Sanjay , Penagaricano Jose
Published: February 2018

Purpose

Intermediate‐ and low‐dose falloff in stereotactic body radiotherapy (SBRT) of lung tumor is known to relate to normal tissue toxicity. The purpose is twofold to analyze the relation between RTOG parameters (namely, R50%, D2cm) in lung SBRT plans and to explore planning methods that correlate with higher than acceptable dose to normal tissue.

Methods

RTOG recommended target dose coverage, conformity index, homogeneity index, R50%, and D2cm were evaluated retrospectively in 105 lung tumor SBRT plans. Deviations in R50% and D2cm were correlated with parameters including prescription dose, tumor location, number of beams or arcs, beam configuration (coplanar or noncoplanar), type of treatment plan (3D‐CRT, IMRT or volumetric arc therapy), and shortest distance to the chest wall.

Result

All plans met the target coverage, conformity index, homogeneity index, and critical organ dose tolerance objectives. Dose falloff product (DFP) of R50% and D2cm has a small variance and small dependence on PTV. Low correlation between DFP and PTV suggests that R50% and D2cm are not independent. Coplanar beam placement was found to be prevalent among plans with large deviations in R50%, D2cm.

Conclusion

This study questions the independence of the two RTOG recommended metrics, R50% and D2cm in lung SBRT plans, and suggests that noncoplanar beams may provide better normal tissue sparing by reducing the intermediate dose falloff.
Technical Note: Quantitative accuracy evaluation for spectral images from a detector‐based spectral CT scanner using an iodine phantom
Authors: Duan Xinhui , Arbique Gary , Guild Jeffrey , Xi Yin , Anderson Jon
Published: February 2018

Purpose

The purpose of this study was to evaluate the quantitative accuracy of spectral images from a detector‐based spectral CT scanner using a phantom with iodine‐loaded inserts.

Methods

A 40‐cm long‐body phantom with seven iodine inserts (2–20 mg/ml of iodine) was used in the study. The inserts could be placed at 5.5 or 10.5 cm from the phantom axis. The phantom was scanned five times for each insert configuration using 120 kVp tube voltage. A set of iodine, virtual noncontrast, effective atomic number, and virtual monoenergetic spectral CT images were generated and measurements were made for all the iodine rods. Measured values were compared with reference values calculated from the chemical composition information provided by the phantom manufacturer. Radiation dose from the spectral CT was compared to a conventional CT using a CTDI (32 cm) phantom.

Results

Good agreement between measurements and reference values was achieved for all types of spectral images. The differences ranged from −0.46 to 0.1 mg/ml for iodine concentration, −9.95 to 6.41 HU for virtual noncontrast images, 0.12 to 0.35 for effective Z images, and −17.7 to 55.7 HU for virtual monoenergetic images. For a similar CTDIvol, image noise from the conventional CT was 10% lower than the spectral CT.

Conclusions

The detector‐based spectral CT can achieve accurate spectral measurements on iodine concentration, virtual non‐contrast images, effective atomic numbers, and virtual monoenergetic images.
Interleaved 3D‐CNNs for joint segmentation of small‐volume structures in head and neck CT images
Authors: Ren Xuhua , Xiang Lei , Nie Dong , Shao Yeqin , Zhang Huan , Shen Dinggang , Wang Qian
Published: February 2018

Purpose

Accurate 3D image segmentation is a crucial step in radiation therapy planning of head and neck tumors. These segmentation results are currently obtained by manual outlining of tissues, which is a tedious and time‐consuming procedure. Automatic segmentation provides an alternative solution, which, however, is often difficult for small tissues (i.e., chiasm and optic nerves in head and neck CT images) because of their small volumes and highly diverse appearance/shape information. In this work, we propose to interleave multiple 3D Convolutional Neural Networks (3D‐CNNs) to attain automatic segmentation of small tissues in head and neck CT images.

Method

A 3D‐CNN was designed to segment each structure of interest. To make full use of the image appearance information, multiscale patches are extracted to describe the center voxel under consideration and then input to the CNN architecture. Next, as neighboring tissues are often highly related in the physiological and anatomical perspectives, we interleave the CNNs designated for the individual tissues. In this way, the tentative segmentation result of a specific tissue can contribute to refine the segmentations of other neighboring tissues. Finally, as more CNNs are interleaved and cascaded, a complex network of CNNs can be derived, such that all tissues can be jointly segmented and iteratively refined.

Result

Our method was validated on a set of 48 CT images, obtained from the Medical Image Computing and Computer Assisted Intervention (MICCAI) Challenge 2015. The Dice coefficient (DC) and the 95% Hausdorff Distance (95HD) are computed to measure the accuracy of the segmentation results. The proposed method achieves higher segmentation accuracy (with the average DC: 0.58 ± 0.17 for optic chiasm, and 0.71 ± 0.08 for optic nerve; 95HD: 2.81 ± 1.56 mm for optic chiasm, and 2.23 ± 0.90 mm for optic nerve) than the MICCAI challenge winner (with the average DC: 0.38 for optic chiasm, and 0.68 for optic nerve; 95HD: 3.48 for optic chiasm, and 2.48 for optic nerve).

Conclusion

An accurate and automatic segmentation method has been proposed for small tissues in head and neck CT images, which is important for the planning of radiotherapy.
Recurrence of Ewing sarcoma: Is detection by imaging follow‐up protocol associated with survival advantage?
Authors: Heinemann Melina , Ranft Andreas , Langer Thorsten , Jürgens Herbert , Kreyer Justus , Vieth Volker , Schäfers Michael , Weckesser Matthias , Simon Thorsten , Hassenpflug Wolf , Corbacioglu Selim , Bielack Stefan , Mayer‐Steinacker Regina , Kühne Thomas , van den Berg Henk , Gelderblom Hans , Bauer Sebastian , Stegger Lars , Dirksen Uta
Published: February 2018

Background

The Cooperative Ewing Sarcoma Study and the Late Effects Surveillance System of the Society for Paediatric Oncology and Haematology recommend a structured follow‐up imaging protocol (FUIP) for patients with Ewing sarcoma (EwS) with decreasing frequency of imaging over the first 5 years. The present study aims to assess the effectiveness of the FUIP for EwS patients regarding survival after relapse.

Patients and methods

A retrospective multicenter analysis on 160 eligible patients with EwS recurrence was performed. Potential survival differences following recurrence diagnosis between patients with protocol‐detected and symptomatic relapse were investigated using the Kaplan–Meier method. Additional subgroup analyses were performed on the relapse type. Overall survival (OS) was calculated from diagnosis of relapse to last follow‐up or death.

Results

In the multicenter analysis, recurrence was detected by FUIP in 77 of 160 patients (48%) and due to symptoms in 83 patients (52%). Regarding the entire study population, OS was significantly superior in patients with protocol‐detected relapse compared to patients with symptomatic relapse (median, 2.4 vs. 1.2 years; P < 0.001). In the subgroup analyses, patients whose lung recurrences were detected by the FUIP experienced longer survival after recurrence than those whose recurrences were detected symptomatically (P = 0.023). In the 83 symptomatic patients, pain was the most prevalent symptom of relapse (72%).

Conclusion

FUIP may benefit survival in EwS relapse, especially in lung recurrence. Pain was the leading symptom of relapse.
Inflammatory myofibroblastic tumors—A retrospective analysis of the Cooperative Weichteilsarkom Studiengruppe
Authors: Kube Stefanie , Vokuhl Christian , Dantonello Tobias , Scheer Monika , Hallmen Erika , Feuchtgruber Simone , Escherich Gabriele , Niggli Felix , Kuehnle Ingrid , von Kalle Thekla , Bielack Stefan , Klingebiel Thomas , Koscielniak Ewa
Published: February 2018

Background

Inflammatory myofibroblastic tumors (IMTs) are a rare subgroup of soft tissue tumors. The outcome of patients with IMT has been reported as favorable when the tumor is completely resected. If surgical resection is not possible, systemic therapy has to be considered. However, the best systemic treatment and response rates are currently unclear.

Methods

Thirty‐eight patients under the age of 21, who were registered between 2000 and 2014 with a primary diagnosis of IMT, were analyzed.

Results

IMT was typically localized intra‐abdominally or in the pelvis. In 20 patients, the tumor was resected without further therapy; 17 patients were in complete remission at last evaluation and two patients were in partial remission. Eighteen patients received systemic therapy, 15 of whom had macroscopically incomplete resection. Systemic therapy most commonly consisted of regimens with dactinomycin, ifosfamide or cyclophosphamide, and vincristine, with or without doxorubicin, and it seemed to reduce tumor extension in individual cases. Five‐year event‐free survival was 74 ± 14% and 5‐year overall survival was 91 ± 10% for all patients. The patients who died due to the disease were those with incomplete resection (n = 3).

Conclusions

Surgery without further systemic therapy was a feasible and acceptable therapeutic option for every second patient with IMT. Standard chemotherapy for pediatric soft tissue sarcoma produced favorable results in individual cases and was able to shrink the tumor enough to enable resection. Superior efficacy of new targeted therapies such as anaplastic lymphoma kinase‐inhibitors compared to standard chemotherapy has to be proven in the future.
Medicanes as subtropical cyclones: the December 2005 case from the perspective of surface pressure tendency diagnostics and atmospheric water budget
Authors: Fita Lluís , Flaounas Emmanouil
Published: February 2018

Mediterranean cyclones with tropical‐like characteristics such as spiral cloud coverage and a central cloud‐free “eye” are referred to as medicanes. These systems have been analyzed due to their relation with high‐impact weather. In previous studies, the identification of medicanes has been typically performed subjectively, using satellite pictures, but also objectively through three‐dimensional diagnosis of a warm core and an axisymmetric structure. Despite the presence of these characteristics, it is still unclear if medicanes show dynamical similarities with tropical cyclones.

We analyse the (thermo‐)dynamics of a recognized medicane that occurred in December 2005 by applying different diagnostics to a high‐resolution simulation. These diagnostics are focused on the intensification, dynamical structure and water budget of this representative case, aiming to highlight extratropical and tropical cyclone characteristics.

Three stages in the medicane life cycle are identified. In stage I, a potential vorticity (PV) streamer reaches the Mediterranean, triggering deep convection and deepening the medicane's central surface pressure due to diabatic heating. When the lowest central pressure is reached (stage II), the medicane presents a warm core and an axisymmetric structure. However, convection is rather weak and the PV streamer evolves into a cut‐off system which contributes to the deepening of the medicane's surface pressure. Finally, stage III corresponds to the decay phase where the medicane tends to weaken and lose its axisymmetric structure.

Our results highlight the detrimental role of deep convection prior to the mature stage of the medicane, as well as the possibility of positive or negative feedback of upper‐tropospheric dynamics on the central surface pressure. In addition, we show that the medicane warm core might be achieved due to front seclusion, while the “eye” formation is associated with dry air intrusions. Our analysis suggests that medicanes are hybrid systems combining characteristics of both tropical and extratropical cyclones and thus they plausibly correspond to subtropical cyclones.
Automated diagnosis of colon cancer using hyperspectral sensing
Authors: Beaulieu Robert J. , Goldstein Seth D. , Singh Jasvinder , Safar Bashar , Banerjee Amit , Ahuja Nita
Published: February 2018

Background

Surgical management of colorectal cancer relies on accurate identification of tumor and possible metastatic disease. Hyperspectral (HS) sensing is a passive, non‐ionizing diagnostic method that has been considered for multiple tumor types. The ability to use HS for identification of tumor specimens during surgical resection of colorectal cancers was explored.

Methods

Patients with colorectal cancer who underwent operative resection were enrolled. HS measurements were performed both intra‐ and extra‐luminally. Spectral results were correlated with pathologic evaluation.

Results

Fifteen patient specimens were analyzed. For patients with confirmed colorectal cancer, extraluminal spectra analysis yielded 61.68% sensitivity with 90% specificity. For intraluminal specimens, sensitivity increased to 91.97% with 90% specificity.

Conclusions

Hyperspectral sensing can reliably detect tumors in resected colon specimens. This research offers promising results for a diagnostic technology that is non‐ionizing and does not require the use of contrast agents to achieve accurate colorectal cancer detection.
A 0.2 V Micro‐Electromechanical Switch Enabled by a Phase Transition
Authors: Dong Kaichen , Choe Hwan Sung , Wang Xi , Liu Huili , Saha Bivas , Ko Changhyun , Deng Yang , Tom Kyle B. , Lou Shuai , Wang Letian , Grigoropoulos Costas P. , You Zheng , Yao Jie , Wu Junqiao
Published: February 2018

Micro‐electromechanical (MEM) switches, with advantages such as quasi‐zero leakage current, emerge as attractive candidates for overcoming the physical limits of complementary metal‐oxide semiconductor (CMOS) devices. To practically integrate MEM switches into CMOS circuits, two major challenges must be addressed: sub 1 V operating voltage to match the voltage levels in current circuit systems and being able to deliver at least millions of operating cycles. However, existing sub 1 V mechanical switches are mostly subject to significant body bias and/or limited lifetimes, thus failing to meet both limitations simultaneously. Here 0.2 V MEM switching devices with ≳106 safe operating cycles in ambient air are reported, which achieve the lowest operating voltage in mechanical switches without body bias reported to date. The ultralow operating voltage is mainly enabled by the abrupt phase transition of nanolayered vanadium dioxide (VO2) slightly above room temperature. The phase‐transition MEM switches open possibilities for sub 1 V hybrid integrated devices/circuits/systems, as well as ultralow power consumption sensors for Internet of Things applications.
Egg Viability and Egg‐to‐Fry Survival of Captive‐Reared Chinook Salmon Released to Spawn Naturally
Authors: Stark Eric J. , Vidergar Dmitri T. , Kozfkay Christine C. , Kline Paul A.
Published: February 2018

Conservation hatchery strategies for anadromous salmonids are designed to boost depressed wild populations while conserving genetic resources. Captive rearing is an approach in which eggs or juveniles are collected from wild fish, taken into a hatchery and reared to maturation, and then released to spawn. In this study, we quantified spawn timing and redd production for captive‐reared and wild Chinook Salmon Oncorhynchus tshawytscha and measured survival of eggs to the eyed stage of development (egg viability) and from egg to fry. The study objective was to determine whether there was a difference in egg viability and egg‐to‐fry survival between captive‐reared and wild Chinook Salmon that spawned in the wild. During 2007–2009, 90 redds were sampled in the East Fork Salmon River, Idaho; 45 of captive‐origin salmon and 45 of wild origin. Egg viability was significantly lower for captive‐reared fish (75.0%) than for their wild counterparts (95.6%). The overall mean egg‐to‐fry survival for captive‐reared fish was quite high (80.4%), and although it was significantly lower than that for wild fish (84.0%), biologically this survival difference was not large. While others have estimated the egg‐to‐fry survival of production hatchery Chinook Salmon in the wild, it had not previously been estimated for captive‐reared fish released to spawn. Through the use of novel techniques such as hydraulic pumping and egg capsules, we were able to successfully estimate egg viability and egg‐to‐fry survival of captive‐reared and wild Chinook Salmon spawning in the wild. Although egg viability and egg‐to‐fry survival of captive‐reared fish was lower than for their wild counterparts, both survival rates may be sufficient to provide a demographic benefit to the receiving wild population.
An optimal grid current control strategy with grid voltage observer (GVO) for LCL‐filtered grid‐connected inverters
Authors: Dou Xiaobo , Jiao Yang , Yang Kang , Wu Zaijun , Gu Wei , Li Haojie , Tang Xiaochen
Published: February 2018

An optimal grid current control strategy with grid voltage observer (GVO) for LCL‐filtered grid‐connected inverters is proposed in this paper. The quasi proportional resonant (QPR) controller is applied in this control strategy conducted in a stationary αβ frame to suppress the transient fluctuations and the total harmonic distortion (THD) of the output grid current and achieve faster transient performance. Active damping is chosen as the damping method in this paper, which uses the capacitor current acting as the feedback of the inner current loop to replace the actual resistor in parallel with the filter capacitor digitally. The LCL‐filtered resonance frequency can be changed by this virtual impendence, and the control system will be stabilized more effectively. In this proposed control strategy, a GVO is introduced to replace the actual sensors, the sampling precision of which can be influenced negatively in the actual experimental environment. The introduced GVO can provide clean and noise‐free estimation of the grid voltage and also reduce the overall cost of the whole control system. The estimated grid voltage acts as the feedforward of the internal current loop, which accelerates the regulating rate of the internal current loop, improves the dynamic response of the system effectively, and restrains the influence caused by grid voltage variation. Finally, the validity of the proposed approach is verified through simulations and a three‐phase prototype test system with a TMS320F28335 digital signal processor. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.