bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Intra‐ and Interscanner Reliability of MRI Protocols for Spinal Cord Gray Matter and Total Cross‐Sectional Area Measurements
Authors: Papinutto Nico , Henry Roland G.
Published: September 2018

Background

In vivo quantification of spinal cord atrophy in neurological diseases using MRI has attracted increasing attention.

Purpose

To compare across different platforms the most promising imaging techniques to assess human spinal cord atrophy.

Study Type

Test/retest multiscanner study.

Subjects

Twelve healthy volunteers.

Field Strength/Sequence

Three different 3T scanner platforms (Siemens, Philips, and GE) / optimized phase sensitive inversion recovery (PSIR), T1‐weighted (T1‐w), and T2*‐weighted (T2*‐w) protocols.

Assessment

On all images acquired, two operators assessed contrast‐to‐noise ratio (CNR) between gray matter (GM) and white matter (WM), and between WM and cerebrospinal fluid (CSF); one experienced operator measured total cross‐sectional area (TCA) and GM area using JIM and the Spinal Cord Toolbox (SCT).

Statistical Tests

Coefficient of variation (COV); intraclass correlation coefficient (ICC); mixed effect models; analysis of variance (t‐tests).

Results

For all the scanners, GM/WM CNR was higher for PSIR than T2*‐w (P< 0.0001) and WM/CSF CNR for T1‐w was the highest (P< 0.0001). For TCA, using JIM, median COVs were smaller than 1.5% and ICC >0.95, while using SCT, median COVs were in the range 2.2–2.75% and ICC 0.79–0.95. For GM, despite some failures of the automatic segmentation, median COVs using SCT on T2*‐w were smaller than using JIM manual PSIR segmentations. In the mixed effect models, the subject was always the main contributor to the variance of area measurements and scanner often contributed to TCA variance (P< 0.05). Using JIM, TCA measurements on T2*‐w were different than on PSIR (P = 0.0021) and T1‐w (P = 0.0018), while using SCT, no notable differences were found between T1‐w and T2*‐w (P = 0.18). JIM and SCT‐derived TCA were not different on T1‐w (P = 0.66), while they were different for T2*‐w (P< 0.0001). GM area derived using SCT/T2*‐w versus JIM/PSIR were different (P< 0.0001).

Data Conclusion

The present work sets reference values for the magnitude of the contribution of different effects to cord area measurement intra‐ and interscanner variability.

Level of Evidence: 1

Technical Efficacy: Stage 4

J. Magn. Reson. Imaging 2019;49:1078–1090.
Pectoralis major radiation recall
Authors: Hack Emma , Thachil Thanuja , Karanth Narayan
Published: September 2018

Radiation recall is an uncommon phenomenon describing an acute localised inflammatory toxicity affecting tissue previously exposed to radiotherapy. It is precipitated by administration of certain medications, including chemotherapy. We describe a case involving a 50‐year‐old Aboriginal male smoker from a remote community in Northern Australia who underwent treatment for stage IV non‐small cell lung cancer with localised radiotherapy to the primary right upper lung lobe tumour. This was followed by a course of gemcitabine, which was ceased prematurely after four cycles when he presented with radiation recall to his right pectoralis major. Our case description is complemented with a brief review of current literature regarding our case and gemcitabine‐related radiation recall. This was in the context of concurrent musculoskeletal strain, an as‐yet unreported association with radiation recall. His condition settled with steroid administration and discontinuation of gemcitabine.
Impact of electrophysiological and pharmacological noninducibility following pulmonary vein isolation in patients with paroxysmal and persistent atrial fibrillation
Authors: Otsuka Takayuki , Sagara Koichi , Arita Takuto , Yagi Naoharu , Suzuki Shinya , Ikeda Takanori , Yamashita Takeshi
Published: September 2018

Background

Two methods for testing inducibility of atrial fibrillation (AF)—atrial pacing and isoproterenol infusion—have been proposed to determine the endpoint of catheter ablation. However, the utility of the combination for testing electrophysiological inducibility (EPI) and pharmacological inducibility (PHI) is unclear.

Methods

After pulmonary vein isolation (PVI), inducibility of atrial tachyarrhythmia was assessed with the dual methods in 291 consecutive patients with AF (65% paroxysmal) undergoing initial catheter ablation.

Results

The incidence of EPI was significantly higher in patients with persistent AF than paroxysmal AF (32.0% vs 11.7%, respectively, P < .001). The incidence of PHI was not significantly different between the two groups (25.2% vs 26.1%, respectively, P = .87). There was no significant difference in AF recurrence according to inducibility in paroxysmal AF. In persistent AF, however, patients achieving neither EPI nor PHI under PVI‐only strategy had significantly lower rates of AF recurrence than those achieving either EPI or PHI and consequently requiring additional ablation for inducible atrial tachyarrhythmia (68.5% vs 49.0%, respectively; log‐rank test, P = .022). In persistent AF, multivariate Cox regression analysis showed that achieving neither EPI nor PHI was a negative independent predictor of AF recurrence (HR 0.492, 95% CI 0.254‐0.916, P = .026).

Conclusions

Achieving neither EPI nor PHI following PVI was associated with favorable outcome in patients with persistent AF. The combination of tests may discriminate patients responsive to the PVI‐only strategy. Further selective approaches are necessary to improve outcome for inducible atrial tachyarrhythmia in patients with persistent AF.
Article alert: 200 items from 2014, grouped and indexed
Authors: Hafdahl Adam R.
Published: September 2018

This ninth Article Alert installment's print component presents 200 methodological articles about research synthesis published in 2014, all grouped by type of contribution and assigned descriptive keywords. More than 5300 articles, book chapters, and other types of work from 2004 to 2008 and 2014 have been added to the archive component since the eighth installment. The online Supporting Information provides this and all previous installments' print‐ and archive‐component records, most with a DOI name or other online identifier. In building the parent bibliographic compilation, more effort has been devoted recently to shorter pieces such as editorial material.
Monitoring of cefepime in urine by micellar electrokinetic capillary chromatography with ultraviolet detection and liquid chromatography coupled to mass spectrometry
Authors: Kummer Mirjam , Šestáková Nela , Theurillat Regula , Huynh‐Do Uyen , Endimiani Andrea , Sendi Parham , Thormann Wolfgang
Published: September 2018

Cefepime monitoring in urine by micellar electrokinetic capillary chromatography with UV detection and liquid chromatography coupled to mass spectrometry via electrospray ionization is described. For micellar electrokinetic capillary chromatography, sample preparation comprised urine dilution and dodecyl‐sulfate protein precipitation at pH 4.5, whereas diluted urines were analyzed in the other assay. Both approaches provided suitable conditions for cefepime analysis in urines of healthy volunteers that were spiked with cefepime. Cefepime monitoring by micellar electrokinetic capillary chromatography in samples from patients taking multiple drugs were prone to interferences, whereas liquid chromatography coupled to mass spectrometry provided clean chromatograms and thus selective detection of cefepime in all samples. The latter assay was used to measure urinary cefepime in a prospective pilot study and to assess cefepime stability in urines at 25, 4, −20 and −70°C. The data suggest that urinary cefepime is stable for at least 72 h at all tested temperatures.
Estimating avian road mortality when only a single observer is available
Authors: Durkin Maureen M. , Cohen Jonathan B.
Published: September 2018

Gulf Islands National Seashore in Florida, USA, hosts breeding populations of migratory beach‐nesting birds, along with other avian species. It consists of 2 barrier islands with a public paved road that runs through the center. For the past decade, bird carcasses were observed opportunistically along the roadway, and this mortality sparked interest among wildlife managers about population‐level effects on species of conservation concern. Accurately estimating wildlife mortality from carcass counts requires correcting negative bias due to imperfect detection and scavenging between surveys. We had only 1 observer available to perform road surveys, leading to a carcass detection rate of 1.0 after discovery, and a persistence rate that was only estimable after discovery. We therefore employed a robust design version of a time‐of‐detection model to estimate detection and persistence rates. We used a post hoc derivation of the superpopulation size for carcasses, which is an estimate of the total number of carcasses that were ever present on the road for any period of time. Each primary survey consisted of 2 passes on the road within 4 hours. Probability of detection for 2 passes was near 100%. We counted 77 avian carcasses between 22 May and 4 July 2013 and estimated that this represented 106.8 ± 21.3 (SE) birds killed on the road during that time period. Opportunistic surveying by park service staff detected between 0% and 100% of carcasses we estimated to be present, depending on the date. Standardized surveys are needed going forward to estimate annual variation in carcass numbers and to determine effectiveness of mortality mitigation. Moreover, further research can use these estimates to understand the contribution of road mortality to population trends. © 2018 The Wildlife Society.
Improving surface heat flux estimation for a large lake through model optimization and two‐point calibration: The case of Lake Geneva
Authors: Rahaghi Abolfazl Irani , Lemmin Ulrich , Cimatoribus Andrea , Bouffard Damien , Riffler Michael , Wunderle Stefan , Barry David Andrew
Published: September 2018

Net Surface Heat Flux (SurHF) was estimated from 2008 to 2014 for Lake Geneva (Switzerland/France), using long‐term temperature depth profiles at two locations, hourly maps of reanalysis meteorological data from a numerical weather model and lake surface water temperatures from calibrated satellite imagery. Existing formulas for different heat flux components were combined into 54 different total SurHF models. The coefficients in these models were calibrated based on SurHF optimization. Four calibration factors characterizing the incoming long‐wave radiation, sensible, and latent heat fluxes were further investigated for the six best performing models. The combination of the modified parameterization of the Brutsaert equation for incoming atmospheric radiation and of similarity theory‐based bulk parameterization algorithms for latent and sensible surface heat fluxes provided the most accurate SurHF estimates. When optimized for one lake temperature profile location, SurHF models failed to predict the temperature profile at the other location due to the spatial variability of meteorological parameters between the two locations. Consequently, the optimal SurHF models were calibrated using two profile locations. The results emphasize that even relatively small changes in calibration factors, particularly in the atmospheric emissivity, significantly modify the estimated long‐term heat content. The lack of calibration can produce changes in the calculated heat content that are much higher than the observed annual climate change‐induced trend. The calibration improved parameterization of bulk transfer coefficients, mainly under low wind regimes.
On estimation of coastal wave parameters and wave‐induced shear stresses
Authors: Xiong J. , Wang Y. P. , Gao S. , Du J. , Yang Y. , Tang J. , Gao J.
Published: September 2018

Wave parameters, e.g., wave height, near‐bed wave orbital velocity, and wave‐induced shear stresses, are important hydrodynamic parameters for sediment processes in coastal oceans. Wave orbital velocity is particularly critical in sediment resuspension. Several algorithms to calculate wave orbital velocity have been proposed, including linear wave theory, spectrum, and Joint North Sea Wave Project methods, but the validity of these algorithms in relatively shallow waters is not well understood. In this study, we compared the wave parameters obtained by different instruments and algorithms at four sites, one within the intertidal zone with a mean depth of 1 m and the remainder three in deeper offshore water with mean depths of 15–30 m. We found a high consistency of the estimated wave height, peak wave period, and wave orbital velocity among different datasets and different algorithms at the offshore sites, while there were significant discrepancies at the shoreline site. Using Ursell number, our study suggests that it is reliable to apply any of the three algorithms and different instruments (acoustic Doppler velocimeter and buoy) in deeper water. However, for very shallow water, it is recommended to use the measured high‐frequency velocity and spectrum method to calculate wave orbital velocity, and use wave gauge instrument or zero‐crossing algorithm to obtain wave height and period information. Finally, the effect of turbulence and bedform morphology on wave‐induced shear stress is discussed: without removing the turbulence or taking onto account bedforms (e.g., ripples), the orbital velocity will be remarkably over‐estimated or under‐estimated.
A new analytical method for determination of the nitrogen isotopic composition of methionine: Its application to aquatic ecosystems with mixed resources
Authors: Ishikawa Naoto F. , Chikaraishi Yoshito , Takano Yoshinori , Sasaki Yoko , Takizawa Yuko , Tsuchiya Masashi , Tayasu Ichiro , Nagata Toshi , Ohkouchi Naohiko
Published: September 2018

Compound‐specific nitrogen isotope (δ15N) analysis of amino acids is a powerful tool for estimating the trophic positions (TPs) of animals. The TP of an animal can be represented as a linear function of the isotopic difference between glutamic acid (δ15NGlu) and phenylalanine (δ15NPhe). However, the method using δ15NGlu and δ15NPhe cannot be applied to animals in mixed food webs where basal resources are derived from both terrestrial and aquatic primary producers, because the mean value of δ15NPhe relative to δ15NGlu differs greatly between terrestrial plants (+8.4‰) and aquatic algae (−3.4‰). To resolve this problem, the δ15N of methionine (δ15NMet) is useful. Because the C–N bond of methionine is not cleaved in its initial metabolic step, theoretically there should be little diversity in δ15NMet relative to δ15NGlu among primary producers and a small trophic discrimination factor for methionine in animal metabolism. We developed a dual‐column‐coupled GC‐C‐IRMS method to determine δ15NMet. Data collected from controlled feeding experiments and wild samples demonstrated that the isotopic difference between methionine and phenylalanine in terrestrial food webs (ΔMet−Phe = −16.5 ± 0.5‰) is clearly distinguishable from that in aquatic food webs (ΔMet−Phe = −5.0 ± 0.5‰). This approach allowed us to determine ecologically reasonable TP values for carnivores in a stream food web, which were substantially underestimated with the conventional method. This method has potential utility in assessing TP for animals that rely on varying proportions of both terrestrial‐ and aquatic‐derived resources, with no requirement to characterize δ15N in their basal resources.
High‐resolution imaging particle analysis of freshwater cyanobacterial blooms
Authors: Graham M. D. , Cook J. , Graydon J. , Kinniburgh D. , Nelson H. , Pilieci S. , Vinebrooke R. D.
Published: September 2018

Effective assessment of the health risk of cyanobacterial blooms requires an early warning system, which enables rapid detection of species of concern and determination of whether their cell concentrations exceed advisory guidelines. Advanced digital flow cytometry using FlowCam® (Fluid Imaging Technologies) in combination with light microscopy is a solid prospect for tracking cyanobacterial communities in a timely manner. However, implementation of such a method poses several challenges for the user. We first address sample preparation, instrumentation, taxonomic enumeration, and trouble‐shooting to facilitate high throughput of analyses of water samples for total cyanobacterial cell counts and their species composition. Preservation and initial screening of samples using light microscopy to estimate community size structure are endorsed to insure their archival quality and avoid clogging of the flow cell. We show that the highest magnification (×20 objective) is needed to achieve representative total and species‐specific cell enumerations. We also report that total cyanobacterial cell counts for samples analyzed using FlowCam vs. inverted light microscopy show significant positive correlation, as do those for preserved vs. live samples. Quantification of community composition using FlowCam vs. light microscopy also shows strong concordance. Although our FlowCam method performs well in the context of the World Health Organization advisory threshold of a total cyanobacterial count of 100,000 cells mL−1, it remains a work in progress in terms of reliably automated species‐level identifications.
The mRECIST Classification Provides Insight into Tumor Biology for Patients With Hepatocellular Carcinoma Awaiting Liver Transplantation
Authors: Lee David D. , Samoylova Mariya , Mehta Neil , Musto Kaitlyn R. , Roberts John P. , Yao Francis Y. , Harnois Denise M.
Published: September 2018

With recent changes in United Network for Organ Sharing policy, patients in the United States with hepatocellular carcinoma (HCC) are likely to spend more time on the liver transplantation (LT) waiting list. The increasing wait time will allow for an opportunity to assess tumor biology prior to LT. Modified Response Evaluation Criteria in Solid Tumors (mRECIST) paradigm provides such a framework for this assessment, and yet little is understood of its utility as it would apply for patients listed for LT in the United States. Through a collaboration between the University of California, San Francisco, and the Mayo Clinic, Jacksonville, Florida, the experience of 772 patients listed for LT were retrospectively reviewed to study the impact of immediate mRECIST classification following locoregional therapy (LRT) on pre‐ and post‐LT outcomes. Patients who had progression of disease (PD; n = 72), failed to respond to LRT (n = 89) at any time point, or did not achieve radiologic complete response (CR; n = 224) were all at significant risk for wait‐list dropout (odds ratio [OR] = 12.11, 4.81, and 2.48; respectively). CR identified a cohort of patients who were at a reduced risk for wait‐list dropout. However, 24.9% eventually required further intervention while waiting for transplant, and as many as 82.4% were found to have residual HCC on explant pathology. Failure to respond to LRT was associated with increased risk for recurrence (OR = 3.00) more so than PD (OR = 1.36), suggesting that despite PD, patients who eventually can respond to LRT may represent favorable candidates for LT. In conclusion, for patients awaiting LT, the mRECIST assessment provides critical guidance for patient management. Although PD portends a poor prognosis, our findings suggest that further aggressive LRT should be pursued because a response to LRT may yield acceptable results for patients awaiting LT as well as after LT.
THE CRUCIAL ROLE OF TALENT IN ORGANIZATIONAL PERFORMANCE
Authors: Lewis Clinton
Published: September 2018

Lewis Jr., a senior executive at Zoetis, a global animal health company, believes the success of a leader hinges on “the ability to attract, develop and retain talented people.” In assessments for a position of greater responsibility, he looks at various factors, which involve a wide range of people: “In assessing my people, I look at their mind‐set, capabilities, and the consistency of their performance—and to that end, I also look at the quality of their team.” He observes the rigor with which his team members develop their own teams, and points out that they “need to develop a robust and diverse talent pipeline lower in the organization, from which we can draw our next generation of leadership.”
Tannic Acid Physically Cross‐Linked Responsive Hydrogel
Authors: Zheng Lu‐Yi , Shi Jing‐Min , Chi Yan‐Hui
Published: September 2018

Tannic acid (TA) is a polyphenol‐rich compound found in many natural plants. There are large numbers of phenolic hydroxyls at the terminal of the TA molecule, being capable of forming hydrogen bonds with hydrogen‐bonding donating polymers such as polyvinylpyrrolidone (PVP) and then engineering a hydrogel network. The reversible switch between phenolic hydroxyls and quinones tuned by pH affords the dynamic nature of the resultant hydrogen bonds. The gels exhibit excellent shear‐thinning and self‐recovery properties. Moreover, the polyphenols can form coordinates with Fe(III) that link different TAs to form a hydrogel network. Hence, adding Fe(III) solution to the TA‐PVP sol can form additional interactions inside the TA‐PVP gel. The easy preparation of the dual‐responsive gels with nontoxic raw materials may allow for its application in the biomedical field.
SPION‐Decorated Nanofibers by RAFT‐Mediated Free Radical Emulsion Polymerization‐Induced Self Assembly
Authors: Nguyen Duc , Huynh Vien , Pham Nguyen , Pham Binh , Serelis Algirdas , Davey Tim , Such Chris , Hawkett Brian
Published: September 2018

RAFT‐mediated free‐radical emulsion polymerization is successfully used to synthesize polystyrene nanofibers using triblock amphiphilic macro‐RAFT copolymers as stabilizers. The polymerization is under RAFT control, producing various morphologies from spherical particles, nanofibers, nanoplatelets, and polymer vesicles. Optimum conditions are established for the synthesis of predominantly negatively charged polymer nanofibers. Superparamagnetic iron oxide nanoparticles (SPION)‐decorated nanofibers are formed by simple mixing of the SPIONs with the fibers at an appropriate pH. The composite material has been found to be superparamagnetic and could be aligned under a magnetic field.
Polymer Nanospheres with Hydrophobic Surface Groups as Supramolecular Building Blocks Produced by Aqueous PISA
Authors: Ebeling Bastian , Belal Khaled , Stoffelbach François , Woisel Patrice , Lansalot Muriel , D'Agosto Franck
Published: September 2018

A robust and straightforward synthesis of waterborne polymer nanospheres bearing the supramolecular association unit dialkoxynapthalene at their surface is presented using polymerization‐induced self‐assembly (PISA). A RAFT agent bearing this unit is first employed to produce poly(acrylic acid) chains, which are then chain‐extended with styrene (S) to spontaneously form the nano‐objects via RAFT aqueous emulsion polymerization. The particular challenge posed by the dialkoxynapthalene hydrophobicity can be overcome by the use of PISA and the deprotonation of the poly(acrylic acid). At pH = 7, very homogeneous latexes are obtained. The particle diameters can be tuned from 36 to 105 nm (with a narrow particle size distribution) by varying the molar mass of the PS block. The surface accessibility of the dialkoxynapthalene moieties is demonstrated by complexation with the complementary host cyclobis(paraquat‐p‐phenylene) (CBPQT4+ · Cl−), highlighting the potential of the nanospheres to act as building blocks for responsive supramolecular structures.
CH Activation as a Shortcut to Conjugated Polymer Synthesis
Authors: Blaskovits J. Terence , Leclerc Mario
Published: September 2018

Direct (hetero)arylation polymerization exploits the palladium‐catalyzed activation of aromatic CH bonds for the atom‐economical synthesis of conjugated polymers for a wide range of applications. This account outlines how direct arylation methodologies overcome many of the limitations of contemporary polymerization techniques at both the research and production scale, and explains how monomer design and reaction conditions must be tailored to ensure high polymer molecular weight, yield, and structural integrity. Current research aims to improve further this reaction's profile as a sustainable methodology while at the same time making it competitive with the Migita–Stille and Miyaura–Suzuki polymerizations both in scope of accessible structures and synthetic efficiency. This feature article charts the recent developments and future directions of CH activation research as it moves toward becoming at once an industrially feasible, environmentally friendly, and synthetically powerful polymerization technique.
Sulfur Polymers Meet Poly(ionic liquid)s: Bringing New Properties to Both Polymer Families
Authors: Gomez Iñaki , De Anastro Asier Fdz , Leonet Olatz , Blazquez Jose Alberto , Grande Hans‐Jürgen , Pyun Jeffrey , Mecerreyes David
Published: September 2018

Sulfur‐containing polymers and poly(ionic liquid)s are emerging macromolecules with unique properties and applications. This article shows the first integration of these two polymer families, leading to materials with a unique combination of properties. The synthetic strategy toward sulfur‐containing poly(ionic liquid)s involves first the copolymerization of elemental sulfur with 4‐vinylbenzyl chloride and subsequent quaternization of the alkyl chloride group using N‐methyl imidazole. The synthetic pathway is completed by the anion exchange reaction of the poly(sulfur‐co‐4‐vinylbenzyl imidazolium chloride) by a sulphonamide anion. The obtained polymers are fully characterized by NMR, FTIR, SEC, DSC, and TGA. The sulfur poly(ionic liquid)s combine some properties related to its poly(ionic liquid) nature, such as anion‐dependent solubility (water vs organic solvents) and high ionic conductivity as well as properties related to its sulfur content, such as redox activity.
New research links smoking to higher risk for dementia
Authors: Canady Valerie A.
Published: September 2018

Researchers seeking to understand whether smoking cessation can alter the risk of dementia have found a lower risk among long‐term quitters. The findings are currently published online in the Annals of Clinical and Translational Neurology and will publish in the October issue.
Initiative to increase youth engagement in MH supports
Authors: Canady Valerie A.
Published: September 2018

Connecting young people to mental health treatment and supports while facilitating community partnerships is the goal of a new two‐year learning opportunity for mental health organizations and other providers in nontraditional settings.
Groups object to Kavanaugh nomination to U.S. Supreme Court
Authors: Canady Valerie A.
Published: September 2018

As confirmation hearings for D.C. Circuit Judge Brett Kavanaugh to be an associate justice on the U.S. Supreme Court got off to a tumultuous start last week, national groups representing people with disabilities have expressed their opposition to his nomination to Senate leadership, pointing to Kavanaugh's views and opinions on cases involving access to health care, self‐determination and civil rights protections.
Compressed‐Sensing MP2RAGE sequence: Application to the detection of brain metastases in mice at 7T
Authors: Trotier Aurélien J. , Rapacchi Stanislas , Faller Thibaut L. , Miraux Sylvain , Ribot Emeline J.
Published: September 2018

Purpose

To develop a Compressed Sensing (CS)‐MP2RAGE sequence to drastically shorten acquisition duration and then detect and measure the T1 of brain metastases in mice at 7 T.

Methods

The encoding trajectory of the standard Cartesian MP2RAGE sequence has been modified (1) to obtain a variable density Poisson disk under‐sampling distribution along the ky‐kz plane, and (2) to sample the central part of the k‐space exactly at TI1 and TI2 inversion times. In a prospective study, the accuracy of the T1 measurements was evaluated on phantoms containing increasing concentrations of gadolinium. The CS acceleration factors were increased to evaluate their influence on the contrast and T1 measurements of brain metastases in vivo. Finally, the 3D T1 maps were acquired with at 4‐fold increased spatial resolution. The volumes and T1 values of the metastases were measured while using CS to reduce scan time.

Results

The implementation of the CS‐encoding trajectory did not affect the T1 measurements in vitro. Accelerating the acquisition by a factor of 2 did not alter the contrast or the T1 values of the brain metastases. 3D T1 maps could be obtained in < 1 min using a CS factor of 6. Increasing the spatial resolution enabled more accurately measurement of the metastasis volumes while maintaining an acquisition duration below 5 min.

Conclusion

The CS‐MP2RAGE sequence could be of great interest in oncology to either rapidly obtain mouse brain 3D T1 maps or to increase the spatial resolution with no penalty on the scan duration.
Hyperpolarized 13C spectroscopic imaging using single‐shot 3D sequences with unpaired adiabatic refocusing pulses
Authors: Wang Jiazheng , Hesketh Richard L. , Wright Alan J. , Brindle Kevin M.
Published: September 2018

Hyperpolarized MRI with 13C‐labeled metabolites has enabled metabolic imaging of tumors in vivo. The heterogeneous nature of tumors and the limited lifetime of the hyperpolarization require high resolution, both temporally and spatially. We describe two sequences that make more efficient use of the 13C polarization than previously described single‐shot 3D sequences. With these sequences, the target metabolite resonances were excited using spectral‐spatial pulses and the data acquired using spiral readouts from a series of echoes created using a fast‐spin‐echo sequence employing adiabatic 180° pulses. The third dimension was encoded with blipped gradients applied in an interleaved order to the echo train. Adiabatic inversion pulses applied in the absence of slice selection gradients allowed acquisition of signal from odd echoes, formed by unpaired adiabatic pulses, as well as from even echoes. The sequences were tested on tumor‐bearing mice following intravenous injection of hyperpolarized [1‐13C]pyruvate. [1‐13C] pyruvate and [1‐13C] lactate images were acquired in vivo with a 4 × 4 × 2 cm3 field of view and a 32 × 32 × 16 matrix, leading to a nominal resolution of 1.25 × 1.25 × 1.25 mm3 and an effective resolution of 1.25 × 1.25 × 4.5 mm3 when the z‐direction point spread function was taken into account. The acquisition of signal from more echoes also allowed for an improvement in the signal‐to‐noise ratio for resonances with longer T2 relaxation times. The pulse sequences described here produced hyperpolarized 13C images with improved resolution and signal‐to‐noise ratio when compared with similar sequences described previously.
Very high‐order accurate finite volume scheme for the convection‐diffusion equation with general boundary conditions on arbitrary curved boundaries
Authors: Costa Ricardo , Nóbrega João M. , Clain Stéphane , Machado Gaspar J. , Loubère Raphaël
Published: September 2018

Obtaining very high‐order accurate solutions in curved domains is a challenging task as the accuracy of discretization methods may dramatically reduce without an appropriate treatment of boundary conditions. The classical techniques to preserve the nominal convergence order of accuracy, proposed in the context of finite element and finite volume methods, rely on curved mesh elements, which fit curved boundaries. Such techniques often demand sophisticated meshing algorithms, cumbersome quadrature rules for integration, and complex nonlinear transformations to map the curved mesh elements onto the reference polygonal ones. In this regard, the reconstruction for off‐site data method, proposed in the work of Costa et al, provides very high‐order accurate polynomial reconstructions on arbitrary smooth curved boundaries, enabling integration of the governing equations on polygonal mesh elements, and therefore, avoiding the use of complex integration quadrature rules or nonlinear transformations. The method was introduced for Dirichlet boundary conditions and the present article proposes an extension for general boundary conditions, which represents an important advance for real context applications. A generic framework to compute polynomial reconstructions is also developed based on the least‐squares method, which handles general constraints and further improves the algorithm. The proposed methods are applied to solve the convection‐diffusion equation with a finite volume discretization in unstructured meshes. A comprehensive numerical benchmark test suite is provided to verify and assess the accuracy, convergence orders, robustness, and efficiency, which proves that boundary conditions on arbitrary smooth curved boundaries are properly fulfilled and the nominal very high‐order convergence orders are effectively achieved.
Pregnancy course and outcomes in mosaic trisomy 16 confined to the placenta: A case series
Authors: Donato Xavier‐Côme , Brechard Marie‐Pierre , François‐Renard Pauline , Hairion Dominique , Quarello Edwin , Hoffet Médéric , Katsogiannou Maria , Desbriere Raoul
Published: September 2018

What's already known about this topic?

T16 CPM is correlated with increased occurrence of intrauterine growth restriction.

Feto‐maternal outcomes of T16 CPM have no predictable pattern, making pregnancy management challenging.

What does this study add?

Intrauterine growth restriction and very low PAPP‐A levels with or without first‐trimester risk <1/250 and, a fortiori, association with placental abnormalities should be indicators for chorionic villus sampling.

Cases should be closely monitored with serial ultrasounds for fetal growth and Doppler flows, FHR and maternal arterial pressure.
Potential therapeutics of Alzheimer's diseases: New insights into the neuroprotective role of trehalose‐conjugated beta sheet breaker peptides
Authors: Di Natale G. , Zimbone S. , Bellia F. , Tomasello M.F. , Giuffrida M.L. , Pappalardo G. , Rizzarelli E.
Published: September 2018

Alzheimer's disease (AD) is a progressive neurodegenerative disease with no cure. The conversion of the amyloid‐β (Aβ) peptide into soluble oligomers has recently become recognized as playing a key role in AD pathogenesis. Thus, prevention and therapeutic strategies against AD focus on modulating Aβ levels aiming also at stabilizing Aβ's monomeric status or inhibiting the peptide's self‐assembly. Peptide‐based inhibitors may provide a reasonable alternative to chemical small molecules. We report herein further insights into the neuroprotective action of two trehalose‐conjugated peptides able to counteract the Aβ's oligomers associated neuronal toxicity. In addition, the Trehalose‐Succinyl‐LPFFD‐NH2 (Th‐Succ‐LPFFD‐NH2) and Ac‐LPFFD‐Trehalose (Ac‐LPFFD‐Th) derivatives protect neuronal cells from excitotoxic insult mediated by NMDA and evoke by themselves pro‐survival signal pathways as an additional cell protective action. UHPLC‐HRMS experiments suggest that a possible step associated to the neuroprotective mechanism involves the cell uptake and/or a membrane interaction of the studied peptides.
Dual‐Responsive Polydimethylsiloxane Networks
Authors: Giebler Michael , Radl Simone Viola , Ast Markus , Kaiser Simon , Griesser Thomas , Kern Wolfgang , Schlögl Sandra
Published: September 2018

Exploiting the salient features of o‐nitrobenzyl chemistry, this work aims at the preparation of polydimethylsiloxane networks that undergo well‐defined bond cleavage in response to either UV light or different pH values as external trigger. Polydimethylsiloxane (PDMS) oligomers with terminal anhydride groups are thermally crosslinked in the presence of a bi‐functional epoxy monomer containing a photolabile o‐nitrobenzyl ester (o‐NBE) group. The susceptibility of the ester groups toward hydrolytic cleavage reactions is used for a pH‐triggered network degradation. Sol–gel analysis confirms that the degradation time can be easily controlled by the base concentration over different time scales varying between hours and weeks. Along with classical ester hydrolysis, photoinduced degradation of the elastomeric networks is carried out by photoisomerization and cleavage of the o‐NBE links upon exposure with UV light. Positive‐tone patterns with a structure size of 100 μm are obtained by photolithographic techniques confirming the spatial control of solubility properties. However, by increasing the exposure dose, recrosslinking of the networks is observed due to side reactions of the primary photocleavage products. As the reformed crosslinks are less sensitive to ester hydrolysis, the side reactions are employed to inscribe negative‐tone microstructures in the PDMS network. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2319–2329
Synthesis of RAFT‐Mediated Amphiphilic Graft Copolymeric Micelle Using Dextran and Poly (Oleic Acid) toward Oral Delivery of Nifedipine
Authors: Karmakar Puja Das , Seesala Venkata Sundeep , Pal Aniruddha , Dhara Santanu , Chatterjee Soumit , Pal Sagar
Published: September 2018

A novel, pH‐responsive supramolecular graft copolymeric micelle, composed of dextran and poly (oleic acid), has been synthesized through reversible addition fragmentation chain transfer polymerization with controlled Mn and narrow polydispersity. The structural properties of the copolymer have been studied using FTIR and 1H NMR spectral analyses. Critical micelle concentration (CMC) has been determined fluorometrically and conductometrically. The copolymer shows pH responsive micellar stability, which has been confirmed using DLS study. Dextran‐g‐OA copolymer demonstrates spherical morphology at CMC, while rod‐like assembly has been evidenced beyond CMC that is probably because of the structural alteration of copolymeric chains at higher copolymer concentration. Dextran‐g‐OA is noncytotoxic toward MG‐63 cells. As the self‐assemble nature of copolymer micelle promotes the oral administration of hydrophobic drugs, nifedipine (NFD, a hydrophobic drug) has been used as model drug that has been encapsulated substantially into the core of the micelle. The copolymer releases the loaded NFD at a much slower rate in simulated gastric fluid (pH 1.2) and relatively faster in simulated intestinal fluid (pH 7.4) with a cumulative release of ~95% within 24 h, suggesting an ideal candidate as nifedipine carrier. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2354–2363
Associations between gait speed and well‐known fall risk factors among community‐dwelling older adults
Authors: Kyrdalen Ingebjørg Lavrantsdatter , Thingstad Pernille , Sandvik Leiv , Ormstad Heidi
Published: September 2018

Background and Purpose

Exercise interventions are effective at preventing falls in community‐dwelling older adults, especially before disability is present. Gait speed below 1.0 m/s is a strong predictor for falls in the elderly. However, evidence is sparse for gait speed alone being sufficient to identify individuals at a high risk of falling. This study aimed to describe the prevalence of fall risk factors among community‐dwelling older adults in their late 70s and to investigate the associations between these risk factors and low gait speed in this population.

Methods

This cross‐sectional cohort study comprised 108 elderly living in a small Norwegian municipality, born between 1936 and 1938. Exclusion criteria were living in residential care, inability to walk 4 m, and severe cognitive impairment. Measurements included gait speed, depressive symptoms, executive functions, fear of falling, vision function, fall history, body mass index, medications, and comorbidity. Gait speed was dichotomized using a cut‐off of 1 m/s, and associations between different risk factors and low gait speed was explored using logistic regression analysis.

Results

Mean gait speed was 1.0 ± 0.3 m/s. In 44.4% of the participants, gait speed was below 1.0 m/s, indicating increased fall risk. Low gait speed was significantly associated with a history of multiple falls (odds ratio [OR] = 3.70, 95% CI [1.18, 11.65]), low educational level (OR = 3.58, 95% CI [1.10, 11.66]), higher number of medications (OR = 4.28, 95% CI [1.63, 11.2]), and higher number of depressive symptoms (OR = 1.31, 95% CI [1.09, 1.58]). We found no significant associations between gait speed and comorbidity, sex, vision, executive functions, or fear of falling.

Conclusion

Our results indicate that gait speed with cut‐off 1.0 m/s could represent a useful tool for identifying individuals who are vulnerable but not yet disabled and could benefit from fall‐preventive exercise. However, extended assessment is probably needed to personalize interventions.
Killing two bugs with one stone: a perspective for targeting multiple pest species by incorporating reproductive interference into sterile insect technique
Authors: Honma Atsushi , Kumano Norikuni , Noriyuki Suzuki
Published: September 2018

The sterile insect technique is an environmentally friendly method to control and even eradicate agricultural and veterinary insect pests without using chemical pesticides in excess. However, the continuous production and release of sterile insects is economically costly and eradication programs using sterile insects have not always been successful owing to the incomplete mating ability of the sterile insects. Here we focus on the theory and empirical findings of interspecific negative mating interaction, known as reproductive interference, to develop a more cost‐effective and value‐added pest management program. We suggest that sterile insects can be used for simultaneous control of both wild‐type conspecifics and closely related pest species by taking advantage of the fact that, when species recognition abilities are incomplete, courtship and mating are often misdirected toward heterospecies. This new approach might help mitigate economic damage and human health crises caused by pest insects. © 2018 Society of Chemical Industry
Morphology Control of Organic–Inorganic Bismuth‐Based Perovskites for Solar Cell Application
Authors: Sanders Simon , Stümmler Dominik , Pfeiffer Pascal , Ackermann Nils , Schimkat Florian , Simkus Gintautas , Heuken Michael , Baumann Peter K. , Vescan Andrei , Kalisch Holger
Published: September 2018

Recently, Pb‐based organometal halide perovskite solar cells have passed 20% power conversion efficiency (PCE). However, the main issue hampering commercialization is toxic Pb contained in these cells. Therefore, great attention is devoted to replace Pb by less harmful metals such as Bi. Yet, the most efficient methylammonium bismuth iodide (MBI) perovskite solar cells reported in literature reach PCE up to 0.2%. In this work, MBI perovskite solar cells, which are processed by spin‐coating under inert nitrogen atmosphere, employing a standard non‐inverted stack are presented. The control of perovskite morphology by modifying the process has been highlighted and the impact on photovoltaic (PV) characteristics has been shown. It is observed that the concentration of the perovskite solution (0.15–0.30 M) has a huge impact on the crystallite size, and the rotation speed during the spin‐coating process determines the layer coverage. Exposure of MBI solar cells to ambient air is found to be essential to obtain the highest short‐circuit current and open‐circuit voltage. The PCE increases over time, from 0.004% directly after processing up to 0.17% after 48 h. The fabricated cells exhibit an open‐circuit voltage of 0.72 V, which is the highest value published for this type of solar cell.
Ultra‐High Vacuum Deposition of Pyrene Molecules on Metal Surfaces
Authors: Schleicher Sebastian , Borca Bogdana , Rawson Jeff , Matthes Frank , Bürgler Daniel E. , Kögerler Paul , Schneider Claus M.
Published: September 2018

Interfacial properties of organic adsorbates featuring aromatic π‐orbitals on metal surfaces play an important role for organic electronics and spintronics. Pyrene is a flat aromatic molecule with a size between ultimately small benzene and extended graphene segments. The deposition of pyrene molecules onto clean and reactive surfaces with a sub‐monolayer coverage under ultra‐high vacuum (UHV) conditions is challenging, since pyrene is a solid with a high vapor pressure. Here, a sublimation procedure under UHV and image pyrene adlayers on in situ prepared Au(111) and Fe/W(110) substrates by means of low‐temperature scanning tunneling microscopy is presented. For Au(111), the molecule–surface interaction is weak as indicated by the specific herringbone reconstruction of the Au(111) surface that is visible through the self‐assembled pyrene adlayer. Pyrene desorption due to weak intermolecular interaction self‐limits the growth to one monolayer (ML). On the more reactive 2–4 ML thick Fe films on W(110), the molecular order of the pyrene adlayer sensitively depends on the Fe thickness‐dependent dislocation pattern at the substrate surface. Irregular arrangements occur for 1 ML Fe and near substrate dislocations for 2–4 ML Fe. Self‐assembled ordered arrays form predominantly for 2 ML Fe, where the dislocation pattern leaves sufficiently large unperturbed areas between the dislocation lines.
Interaction Channels Between Perfluorinated Iron Phthalocyanine and Cu(111)
Authors: Belser Axel , Karstens Reimer , Nagel Peter , Merz Michael , Schuppler Stefan , Chassé Thomas , Peisert Heiko
Published: September 2018

The initial growth and interfacial electronic structure of perfluorinated iron phthalocyanine (FePcF16) on Cu(111) has been studied using X‐ray photoelectron spectroscopy (XPS) and polarization dependent X‐ray absorption spectroscopy (XAS). The planar molecules are oriented preferred flat lying on the substrate surface during the growth of the first layers while the tilt angle is increased in thicker films. A clear interaction at the interface is observed, involving both the central metal ion and the macrocycle. At monolayer coverages, the Fe2p spectrum shows an interface signal at 707.1 eV, while the C‐N component of the C1s spectrum is distinctly shifted with respect to the thicker films. In addition, the nitrogen atom is involved in the complex interaction (including charge transfer), best visible in the change of the shape in the π* resonance of N K edge spectra recorded from molecules at the interface.
Heme FeSO2− intermediates in sulfite reduction: Contrasts with FeOO2− species from oxygen–oxygen bond activating systems
Authors: Surducan Mihai , Brânzanic Adrian M.V. , Silaghi‐Dumitrescu Radu
Published: September 2018

Sulfite reductase (SiR) catalyzes a six electron and six proton reduction of sulfite to sulfide. Similarly to the cytochrome P450 (cytP450) family, the active site in SiR contains a (partially reduced) heme bound axially to a cysteinate ligand—though with an extra Fe4S4 cluster. Fe(III)SO2−, Fe(III)SOH−, and Fe(III)SO(H2) intermediates have been proposed for the catalytic cycle of SiR, leading to a formally Fe(V)S species—akin to the widely accepted reaction mechanism in cytP450. Here, density functional theory (DFT) data is reported for of such FeSO(H2) intermediates. The Fe(III)SO2− models display relatively high energies for homolytic bond breaking compared to their isomeric oxygen‐bound Fe(III)OS2− models, and thus offer a better alternative in terms of avoiding radical side products able to induce enzyme suicide. This could be due to the fact that the (iron‐bound) sulfur is more active from a redox standpoint compared to oxygen, thus permitting the departing oxygen to maintain a redox‐inert state. Di‐protonation of the oxygen is computed to lead to a compound I type Fe(IV)S coupled to a porphyrin radical anion—consistent with an intermediate previously observed by x‐ray crystallography.