bluuebunny/crossref_metadata_2025_split huggingface dataset:
Image‐based retrospective 4D MRI in external beam radiotherapy: A comparative study with a digital phantom
Authors: Paganelli Chiara , Kipritidis John , Lee Danny , Baroni Guido , Keall Paul , Riboldi Marco 
Published: May 2018

PurposeSeveral image‐based retrospective sorting methods of 4D magnetic resonance imaging (4D MRI) have been proposed for respiratory motion reconstruction in external beam radiotherapy. However, the optimal strategy for providing accurate and artifact‐free 4D MRI, ideally corresponding to an average breathing cycle, is not yet defined. This study presents a proactive comparison of three published image‐based sorting methods, to define a groundwork for benchmarking in 4D MRI.MethodsThree published 4D MRI methods were selected for image retrospective sorting: body area, mutual information, and navigator slice. The three image‐based methods were compared against a conventional retrospective sorting method based on an external surrogate. Comparisons were performed by means of an MRI digital phantom, derived from the XCAT CT phantom generated with different patient‐derived signals, for a total of 12 cases. Specific multislice MRI acquisitions were simulated for slice sorting and sagittal, coronal, and axial orientations were tested. An average 4D cycle was generated as ground truth.ResultsIndividual and grouped patient analyses showed better performance of the navigator slice and mutual information in amplitude binning with respect to the body area strategy. Binning artifacts were reduced on the diaphragm with the slice navigator method due to the acquired internal information. Tumor motion description accurately matched the ground truth in the mutual information strategy with amplitude binning. The body area method followed the performance of the external surrogate and presented larger errors, since was not correlated with the internal anatomy. Sagittal and coronal orientations reported lower errors than axial slicing. Individual analysis showed the need of a patient‐specific evaluation for the selection of the best method.ConclusionsA comparison between three different image‐based retrospective sorting methods for 4D MRI is proposed, providing guidelines for benchmark definition in MRI‐guided radiotherapy.
Prospective frequency correction using outer volume suppression‐localized navigator for MR spectroscopy and spectroscopic imaging
Authors: Lee Chu‐Yu , Choi In‐Young , Lee Phil 
Published: May 2018

PurposeNew frequency correction methods are required to achieve the accurate measurement of frequency drifts in MRS and MRSI. We present a prospective frequency correction method with outer volume suppression (OVS)‐based localization and selective water excitation for effective frequency correction with better SNR improvement compared to other techniques.MethodsAn OVS‐localized navigator was developed to prospectively correct frequency drifts during MRS and MRSI measurements. The performance of the navigator was tested on the human brain and a solution phantom for frequency drifts induced by head motion or gradient heating by a preceding DWI experiment at 3T.ResultsThe OVS‐localized navigator could accurately track motion‐induced frequency drifts with an RMS error of 0.5 Hz. The SNR of MRS signals was not affected by use of the OVS‐localized navigator when compared with and without the navigator (P > 0.05). The frequency drifts induced by DWI experiments were 5.1 ± 0.3 Hz/min during MRSI measurements on humans, resulting in increased spectral linewidth, significant bias in metabolite concentrations, and significantly increased Cramér‐Rao lower bounds (P < 0.05). After prospective frequency corrections, the quality of MRSI was recovered to the level of those without any DWI‐induced frequency drifts, judged by the spectral linewidth, metabolite concentrations, and Cramér‐Rao lower bounds.ConclusionThe OVS‐localized navigator demonstrated effective prospective frequency corrections for large frequency drifts (5 Hz/min) without introducing any saturation‐induced SNR loss. These benefits can be particularly beneficial for the acquisition of MRS signals with long T1 and/or short TR, and spectral editing.
Factor structure of the WISC‐V in four standardization age groups: Exploratory and hierarchical factor analyses with the 16 primary and secondary subtests
Authors: Canivez Gary L. , Dombrowski Stefan C. , Watkins Marley W. 
Published: May 2018

AbstractThis study examined the factor structure of the Wechsler Intelligence Scale for Children‐Fifth Edition (WISC‐V) with four standardization sample age groups (6–8, 9–11, 12–14, 15–16 years) using exploratory factor analysis (EFA), multiple factor extraction criteria, and hierarchical EFA not included in the WISC‐VTechnical and Interpretation Manual. Factor extraction criteria suggested that one to four factors might be sufficient despite the publisher‐promoted, five‐factor solution. Forced extraction of five factors resulted in only one WISC‐V subtest obtaining a salient pattern coefficient on the fifth factor in all four groups, rendering it inadequate. Evidence did not support the publisher's desire to split Perceptual Reasoning into separate Visual Spatial and Fluid Reasoning dimensions. Results indicated that most WISC‐V subtests were properly associated with the four theoretically oriented first‐order factors resembling the WISC‐IV, thegfactor accounted for large portions of total and common variance, and the four first‐order group factors accounted for small portions of total and common variance. Results were consistent with EFA of the WISC‐V total standardization sample.
Association of follicular fluid volume with membrane stretchability of human metaphase II oocytes following the gonadotropin‐releasing hormone agonist protocol during intracytoplasmic sperm injection
Authors: Inoue Taketo , Taguchi Sayumi , Hirao Kayoko , Tsujimoto Yoshiko , Yamamoto Shuji , Uemura Mikiko , Miyazaki Kazunori , Yamashita Yoshiki 
Published: May 2018

AbstractPurposeThe authors previously revealed the association of the follicular fluid (FF) volume with oolemma stretchability following the gonadotropin‐releasing hormone (GnRH) antagonist protocol during intracytoplasmic sperm injection (ICSI). However, the impact of the GnRH agonist protocol on oolemma stretchability remains unclear.MethodsData that were obtained from 74 ICSI cycles were reviewed retrospectively. Controlled ovarian stimulation was performed in accordance with the short GnRH agonist protocol. Each follicle was individually aspirated and assigned to one of six groups, according to the FF volume. The oolemma stretchability during ICSI was evaluated by using a mechanical stimulus for oolemma penetration; that is, oolemma penetration with or without aspiration (high vs low stretchability, respectively).ResultsThe incidence of low oolemma stretchability was significantly higher in the <1.0 mL group than that in the ≥1.0 mL group. The normal fertilization rate was significantly lower in the <1.0 mL group than that in the 2.0‐<3.0 mL group. The rate of blastocyst development was lower in the <1.0 mL group than that in the 3.0‐<4.0 mL group.ConclusionThe FF volume potentially was associated with metaphase II oolemma stretchability, fertilization, and blastocyst development.
Allogeneic Umbilical Cord Blood Infusion for Adults with Ischemic Stroke: Clinical Outcomes from a Phase I Safety Study
Authors: Laskowitz Daniel T. , Bennett Ellen R. , Durham Rebecca J. , Volpi John J. , Wiese Jonathan R. , Frankel Michael , Shpall Elizabeth , Wilson Jeffry M. , Troy Jesse , Kurtzberg Joanne 
Published: May 2018

Abstract
Stroke is a major cause of death and long-term disability, affecting one in six people worldwide. The only currently available approved pharmacological treatment for ischemic stroke is tissue plasminogen activator; however, relatively few patients are eligible for this therapy. We hypothesized that intravenous (IV) infusion of banked unrelated allogeneic umbilical cord blood (UCB) would improve functional outcomes in patients with ischemic stroke. To investigate this, we conducted a phase I open-label trial to assess the safety and feasibility of a single IV infusion of non-human leukocyte antigen (HLA) matched, ABO matched, unrelated allogeneic UCB into adult stroke patients. Ten participants with acute middle cerebral artery ischemic stroke were enrolled. UCB units were matched for blood group antigens and race but not HLA, and infused 3–9 days post-stroke. The adverse event (AE) profile over a 12 month postinfusion period indicated that the treatment was well-tolerated in these stroke patients, with no serious AEs directly related to the study product. Study participants were also assessed using neurological and functional evaluations, including the modified Rankin Score (mRS) and National Institute of Health Stroke Scale (NIHSS). At 3 months post-treatment, all participants had improved by at least one grade in mRS (mean 2.8 ± 0.9) and by at least 4 points in NIHSS (mean 5.9 ± 1.4), relative to baseline. Together, these data suggest that a single i.v. dose of allogeneic non-HLA matched human UCB cells is safe in adults with ischemic stroke, and support the conduct of a randomized, placebo-controlled phase 2 study.
Ternary Composite of Biomass Porous Carbon/SnO2/Pt: An Efficient Catalyst for Reduction of Aromatic Nitro Compounds
Authors: Shang Huishan , Du Lulu , Guan Huijuan , Zhang Bing , Xiang Xu 
Published: May 2018

AbstractTernary composite of biomass porous carbon/SnO2/Pt was prepared by a facile two‐step method consisting of the hydrothermal process and the impregnation‐chemical reduction procedure. The SEM and TEM revealed that particles of SnO2 deposited on the surface of porous carbon (PC) and formed an intermediate layer, which facilitated Pt nanoparticles (around 3–4 nm) to deposit uniformly and firmly on the surface. The ternary composite catalyst of Pt‐SnO2/PC exhibited significantly enhanced performance during the catalytic reduction of 4‐nitrophenol to 4‐aminophenol, and the reaction could completely finished within 80 seconds at room temperature, which apparent rate constant (Ka=71 × 10−3 s−1) was approximately 36 times higher than that of Pt/PC with the same Pt loading. The hybrid catalyst also presented a good stability and the catalytic activity could maintain above 90% even after eighth recycling of reaction. Due to its unique structure and high catalytic performance, ternary composite of Pt‐SnO2/PC has great potential in catalysis applications.
Ru(II)‐Catalyzed Hydroarylation of Maleimides with Cyclic N‐SulfonylKetimines through ortho‐C‐H Bond Activation
Authors: Reddy Keesari N. , Krishna Rao Medikonda V. , Sridhar Balasubramanian , Reddy Basi V. Subba 
Published: May 2018

AbstractA highly regioselective Ru(II)‐catalyzed hydroarylation of maleimides with 3‐aryl cyclic N‐sulfonyl ketimines has been developed for the first time to produce 3‐[(isothiazol‐3‐yl)phenyl]succinimide derivatives in good yields. This method is a simple and atom‐economical, which provides pharmaceutically relevant 3‐arylsuccinimide derivatives.
Synthesis, Characterization, and Structure of a [Cu(phen)2(OTf)]OTf Complex: An Efficient Nitrogen Transfer Pre‐catalyst.
Authors: Valle Henry U. , Riley Kathleen M. , Russell Dylan E. , Wolgemuth Daniel K. , Voges‐Haupt C. Flannery , Rogers T. Alexander , Redd Shanterell L. , Stokes Sean L. , Emerson Joseph P. 
Published: May 2018

AbstractAziridines are valued as important building blocks for the synthesis of a wide range of active compounds. The development of efficient, cost effective catalysts for nitrene transfer reactions to olefins is a continuing area of research in modern chemistry. There are a number of transition metal complexes that are known to catalyse the aziridination of olefins, however most require expensive transition metal ions. Herein we report our efforts to generate aziridines using a copper(II) complex that offers high efficiency at forming aziridines from olefins and N‐transfer agents.
Brønsted‐Acid‐Catalyzed para‐Selective Diazotization of Anilines with Aryl Diazonium Tetrafluoroborates
Authors: Xiong Biquan , Wang Gang , Wan Liming , Xiong Tao , Zhou Congshan , Liu Yu , Zhang Panliang , Yang Changan , Tang Kewen 
Published: May 2018

AbstractAn efficient brønsted acid‐catalyzed method for the para‐selective diazotization at the aromatic carbon‐hydrogen sites para to an amido substituent in nonpolar solvent is illustrated, using aryl diazonium tetrafluoroborates as diazotization reagents. The direct transformation occurs under mild reaction conditions with ample scope, avoids the use of metals, and is tolerated with valuable functional groups. It is a simple way to generate a broad spectrum of functionalized azo anilines from basic starting materials with good to excellent yields.
Enantioselective Palladium‐Catalyzed N‐Allylation of Lactams
Authors: Visse Robin , Fidan Mesut , Götzinger Alissa , Motzny Angelika , Jeddi Samir , Braun Manfred 
Published: May 2018

AbstractN‐Deprotonated five‐, six‐, seven, and nine‐membered lactams undergo smooth palladium‐catalyzed N‐allylation with methyl‐(pent‐3‐en‐2‐yl)‐carbonate or 2‐chloro‐3‐pentene. With axially chiral bisphosphane ligands, enantioselectivities ranging from 83 to 97% ee are reached. The configuration of one of the allylation products is assigned unambiguously by the preparation of a relay compound and by analogy to the others. Using the enantioselective allylation protocol as a key step, δ‐valerolactam is converted into (4S,9aR)‐4‐methylquinolizidine.
Heavy-lifting of gauge theories by cosmic inflation
Authors: Kumar Soubhik , Sundrum Raman 
Published: May 2018

AbstractFuture measurements of primordial non-Gaussianity can reveal cosmologically produced particles with masses of order the inflationary Hubble scale and their interactions with the inflaton, giving us crucial insights into the structure of fundamental physics at extremely high energies. We study gauge-Higgs theories that may be accessible in this regime, carefully imposing the constraints of gauge symmetry and its (partial) Higgsing. We distinguish two types of Higgs mechanisms: (i) a standard one in which the Higgs scale is constant before and after inflation, where the particles observable in non-Gaussianities are far heavier than can be accessed by laboratory experiments, perhaps associated with gauge unification, and (ii) a “heavy-lifting” mechanism in which couplings to curvature can result in Higgs scales of order the Hubble scale during inflation while reducing to far lower scales in the current era, where they may now be accessible to collider and other laboratory experiments. In the heavy-lifting option, renormalization-group running of terrestrial measurements yield predictions for cosmological non-Gaussianities. If the heavy-lifted gauge theory suffers a hierarchy problem, such as does the Standard Model, confirming such predictions would demonstrate a striking violation of the Naturalness Principle. While observing gauge-Higgs sectors in non-Gaussianities will be challenging given the constraints of cosmic variance, we show that it may be possible with reasonable precision given favorable couplings to the inflationary dynamics.
Electrical Resistivity Imaging and the Saline Water Interface in High-Quality Coastal Aquifers
Authors: Costall A. , Harris B. , Pigois J. P. 
Published: May 2018

AbstractPopulation growth and changing climate continue to impact on the availability of natural resources. Urbanization of vulnerable coastal margins can place serious demands on shallow groundwater. Here, groundwater management requires definition of coastal hydrogeology, particularly the seawater interface. Electrical resistivity imaging (ERI) appears to be ideally suited for this purpose. We investigate challenges and drivers for successful electrical resistivity imaging with field and synthetic experiments. Two decades of seawater intrusion monitoring provide a basis for creating a geo-electrical model suitable for demonstrating the significance of acquisition and inversion parameters on resistivity imaging outcomes. A key observation is that resistivity imaging with combinations of electrode arrays that include dipole–dipole quadrupoles can be configured to illuminate consequential elements of coastal hydrogeology. We extend our analysis of ERI to include a diverse set of hydrogeological settings along more than 100 km of the coastal margin passing the city of Perth, Western Australia. Of particular importance are settings with: (1) a classic seawater wedge in an unconfined aquifer, (2) a shallow unconfined aquifer over an impermeable substrate, and (3) a shallow multi-tiered aquifer system over a conductive impermeable substrate. We also demonstrate a systematic increase in the landward extent of the seawater wedge at sites located progressively closer to the highly urbanized center of Perth. Based on field and synthetic ERI experiments from a broad range of hydrogeological settings, we tabulate current challenges and future directions for this technology. Our research contributes to resolving the globally significant challenge of managing seawater intrusion at vulnerable coastal margins.
Short, medium and long‐term effects of density on the demographic traits of a threatened newt
Authors: Vignoli Leonardo , Velletrani Fabiana , Venditti Cristina , Luiselli Luca , Yadid Yitzhak , Macale Daniele 
Published: May 2018

AbstractMediterranean streams undergo seasonal reductions in water availability that may affect amphibian demography due to habitat loss and the concentration of individuals in the shrinking aquatic habitats. However, there are few empirical examples of how increased population density experienced by larval stages produces long‐term effects on growth and fitness at postmetamorphic stages. We tested the effect of four different larval densities on the demography and growth of the endangered stream‐dwelling newt Euproctus platycephalus. By manipulating larval populations in experimental aquaria, we analyzed the short‐term effects of density in terms of growth and mortality rates as well as of social behavior. To assess medium‐ and long‐term effects we tested the metamorph individuals after 1 and 3 years, respectively, and adults for maternal effect by assessing the relationship between mean larval size and fecundity. Larval body size and growth rate appeared inversely proportional to larval density. Density affected the incidence of aggressive behavior by increasing the rate of mutilation to arms and tail. One‐year‐old salamanders raised at the highest larval density grew significantly less. All 3‐year‐old individuals reached comparable body size and body condition irrespective of initial larval density. Salamanders presented a positive relationship between maternal size and (1) fecundity and (2) larval size. In natural conditions, increased density may cause slower growth and a reduction in the percentage of individuals reaching metamorphosis. Prolonged dry periods and increased water withdrawals for agricultural and industrial practices have almost certainly affected the population dynamics of Sardinian newt populations in the long term.
Characteristics of Airplanes and Helicopters Recorded by a Dense Seismic Array Near Anza California
Authors: Meng Haoran , Ben‐Zion Yehuda 
Published: May 2018

AbstractWe observe frequent air traffic events in continuous seismic waveforms recorded for about 30 days by 1,108 vertical geophones in a tight array on the San Jacinto fault zone. The waveforms of the air traffic events resemble tremor or collections of small earthquakes. However, time‐frequency analysis reveals clear Doppler effects that can be modeled with basic equations and fitted well with parameters corresponding to airplanes and helicopters. The flying traces can be inverted by fitting the parameters at each station across the entire array. About 31 air traffic events are detected per day in the relatively remote study area, with peak activity from about 8:00 to 18:00 and significantly fewer events between 23:00 and 4:00 local time. The average event duration is about 200 s, so they cover together >7% of the day. To estimate the total time covered by earthquakes, we derive a scaling relation logτ(M) = 0.41M + 0.89 between earthquake duration and magnitudes using data of 266 earthquakes in the magnitude range 0 ≤ M ≤ 3. The results indicate that in most places, the duration of air traffic events is likely to exceed considerably the total time covered by earthquakes.
Acidification and Climate Linkages to Increased Dissolved Organic Carbon in High‐Elevation Lakes
Authors: Gavin A. L. , Nelson S. J. , Klemmer A. J. , Fernandez I. J. , Strock K. E. , McDowell W. H. 
Published: May 2018

AbstractIncreasing concentrations of dissolved organic carbon (DOC) in the northeastern U.S. have been attributed to two potential mechanisms: recovery from acidification and changing climate. Maine's high‐elevation lakes (>600m) could potentially provide unique insight into the response of surface water chemistry to declining acidic deposition and interannual climate variability. The geochemical response in 29 lakes was analyzed during 30 years of change in sulfate (
) deposition and climate. All 29 lakes exhibited positive trends in DOC from 1986 to 2015, and 19 of 29 lakes had statistically significant increases in DOC throughout the study period. These results illustrate a region‐wide change from low‐DOC lakes (<5mg/L) to moderate DOC lakes (5–30mg/L). Increasing DOC trends for these high‐elevation lakes were more consistent than for lower elevation lakes in the northeastern U.S. A linear mixed effects model demonstrated that lake water
and climate variables describe most of the variability in DOC concentrations (r2 = 0.78), and the strongest predictor of DOC concentration was an inverse relationship with
. Due to
concentrations trending toward preacidification levels and projections of a warmer, wetter, and more variable climate, there is uncertainty for the future trajectory of DOC trends in surface waters. Long‐term monitoring of Maine's high‐elevation lakes is critical to understand the recovery and response in surface water chemistry to a changing chemical and physical environment in the decades ahead.
Modulation of Annual Cycle of Tornadoes by El Niño–Southern Oscillation
Authors: Allen John T. , Molina Maria J. , Gensini Vittorio A. 
Published: May 2018

AbstractLong‐term trends suggest shifts toward earlier tornado season peaks, and yet fail to examine the role of year‐to‐year climate variability. Here, El Niño–Southern Oscillation phase is demonstrated to influence annual cycle characteristics of United States tornadoes. Observations and favorable environments show substantial modification of the peak spatial distribution and the temporal onset of tornado occurrence. La Niña produces an earlier annual peak probability by 1.5–2 weeks, with a higher overall fraction of events in March and April. In contrast, El Niño leads to a week delay in the maximum probability and enhances a second peak in the fall months. Consequently, this suggests that climate change is not the sole driver of changes to seasonal onset and peak, and climate variability plays an important role in modulating the annual cycle.