bluuebunny/crossref_metadata_2025 huggingface dataset:
Adoption of high technology medical imaging and hospital quality and efficiency: Towards a conceptual framework
Authors: Sandoval Guillermo A. , Brown Adalsteinn D. , Wodchis Walter P. , Anderson Geoffrey M.
Published: May 2018

Measuring the value of medical imaging is challenging, in part, due to the lack of conceptual frameworks underlying potential mechanisms where value may be assessed. To address this gap, this article proposes a framework that builds on the large body of literature on quality of hospital care and the classic structure‐process‐outcome paradigm. The framework was also informed by the literature on adoption of technological innovations and introduces 2 distinct though related aspects of imaging technology not previously addressed specifically in the literature on quality of hospital care: adoption (a structural hospital characteristic) and use (an attribute of the process of care).

The framework hypothesizes a 2‐part causality where adoption is proposed to be a central, linking factor between hospital structural characteristics, market factors, and hospital outcomes (ie, quality and efficiency). The first part indicates that hospital structural characteristics and market factors influence or facilitate the adoption of high technology medical imaging within an institution. The presence of this technology, in turn, is hypothesized to improve the ability of the hospital to deliver high quality and efficient care. The second part describes this ability throughout 3 main mechanisms pointing to the importance of imaging use on patients, to the presence of staff and qualified care providers, and to some elements of organizational capacity capturing an enhanced clinical environment.

The framework has the potential to assist empirical investigations of the value of adoption and use of medical imaging, and to advance understanding of the mechanisms that produce quality and efficiency in hospitals.
Impacts of forest structure on precipitation interception and run‐off generation in a semiarid region in northern China
Authors: Liu Jiakai , Zhang Zhenming , Zhang Mingxiang
Published: May 2018

Water resource scarcity and uneven distribution are 2 major environmental issues in China today. Forest structure is a dominant factor that influences hydrological processes, but the specific interactions remain uncertain due to the predominant use of individual or 1‐dimensional forest structure metrics in previous studies. In this study, forest structures in 8 run‐off plots on Mount Miaofeng in north China were parameterized by metrics of different dimensionalities. The relation between canopy interception and forest structure, shrub/litter interception, and forest structure as well as run‐off and forest structure were analysed by regression method and validated by leave‐one‐out cross test. The results showed that canopy interception rates ranged from less than 0.10 all the way to 0.80, affected by forest structure and precipitation, with interception rate decreasing logarithmically as precipitation increased. Forests with a larger canopy area (CA), leaf area index (LAI), and higher average height (H) had a narrow range of canopy interception rates, and forest with larger value of diameters at breath height (DBH),H,LAI, vertical heterogeneity coefficient (T), and structure complexity index (SCI) had higher interception rates. Forests with higher value ofDBH,H, and horizontal heterogeneity coefficient (R) had higher shrub/litter interception rates on the forest floor. The run‐off coefficient was only significantly associated withLAI,T, andSCI. The validation test indicated that regression analysis of canopy interception rates and shrub interception are reliable andSCIis a key factor to influence the run‐off coefficient. However, the regression results of litter interception have a relatively large error. According to the results, to reduce the risks of the landslides and floods, forest managers should complicate the canopy and preserve trees with thicker stems and larger canopies. By contrast, to obtain more water resource from run‐off in arid regions, forest managers should harvest trees with large canopies and construct complex vertical structures by intermediate cutting.
Water flow velocity over frozen and nonfrozen black soil slopes
Authors: Chen Chao , Ban Yunyun , Lei Tingwu , Feng Ren , Gao Yuan
Published: May 2018

Ice‐ and snow‐melted water flow over partially thawed frozen soil of cultivated slopes causes serious soil erosion, which results in soil degradation and affects productivity in Northeast China. Water flow velocity over frozen and nonfrozen soil shows importance in understanding meltwater erosion. In this work, a series of laboratory experiments were conducted to measure water flow velocity over frozen and nonfrozen soil slopes. Experiments were performed using the electrolyte trace method under the pulse boundary model, under conditions of 4 slope gradients (5°, 10°, 15°, and 20°), 3 flow rates (1, 2, and 4 L/min), and 7 sensors positioned at 0.1, 1.0, 2.0, 3.0, 4.0, 5.0, and 6.0 m away from the electrolyte injection point. Results showed that velocities over frozen soil slopes increased with flow rate and slope gradient. Flow velocities over nonfrozen soil slopes increased with flow rate and slope gradients from 5° to 15° and stabilized at 15°. Flow velocities over frozen soil slopes were 30%, 54%, 71%, and 91% higher than those over nonfrozen ones at slope gradients of 5°, 10°, 15°, and 20°. Flow velocities over frozen soil slopes under different flow rates of 1, 2, and 4 L/min were approximately 52%, 59%, and 79% higher than those over nonfrozen soil, respectively. This study can help in assessing the erosion of partially thawed frozen soil by meltwater flow.
Clogging of saturated porous media by silt‐sized suspended solids under varying physical conditions during managed aquifer recharge
Authors: Du Xinqiang , Ye Xueyan , Zhang Xiaowan
Published: May 2018

Managed aquifer recharge is an effective method for utilizing excess flood flows, but clogging of porous media is a limiting factor in the implementation of this water storage technique. In recent years, much research on the physical clogging of porous media during artificial recharge has been conducted. However, the understanding of clogging due to silt‐sized suspended solids (SS) is still inadequate, especially under varying physical conditions. Here, we subjected sand columns to controlled rates of flow and SS suspensions to investigate the influence of media size, SS size, SS concentration, and flow velocity on the clogging of porous media by silt‐sized SS. The results show that the diameter ratio of SS particles to sand grains is the dominant factor influencing the position of physical clogging. As pore velocity increased, the mobility of silt‐sized SS was enhanced and retention in the porous media decreased noticeably. The spatial retention profiles in the porous media were found to vary greatly at different flow velocities. The SS concentration of the infiltrating suspension also dramatically influenced the mobility and deposition of silt‐sized SS particles, such that high concentrations accelerated the clogging process. As the different physical factors changed, the breakthrough curves and retention profiles of silt‐sized SS particles changed obviously and the mechanisms of retention differed. On the whole, clogging position is mainly determined by particle size ratio, but clogging rate is dominated by a variety of factors including particle size ratio, SS concentration, and flow velocity.
In situ chemically specific mapping of agrochemical seed coatings using stimulated Raman scattering microscopy
Authors: Wang Chun‐Chin , Moorhouse Siân , Stain Chris , Seymour Mark , Green Ellen , Penfield Steven , Moger Julian
Published: May 2018

Providing sufficient, healthy food for the increasing global population is putting a great deal of pressure on the agrochemical industry to maximize crop yields without sustaining environmental damage. The growth and yield of every plant with sexual reproduction, depends on germination and emergence of sown seeds, which is affected greatly by seed disease. This can be most effectively controlled by treating seeds with pesticides before they are sown. An effective seed coating treatment requires a high surface coverage and adhesion of active ingredients onto the seed surface and the addition of adhesive agents in coating formulations plays a key role in achieving this. Although adhesive agents are known to enhance seed germination, little is understood about how they affect surface distribution of actives and how formulations can be manipulated to rationally engineer seed coating preparations with optimized coverage and efficacy. We show, for the first time, that stimulated Raman scattering microscopy can be used to map the seed surface with microscopic spatial resolution and with chemical specificity to identify formulation components distributed on the seed surface. This represents a major advance in our capability to rationally engineer seed coating formulations with enhanced efficacy.
Automated three‐dimensional cell counting method for grading uveitis of rodent eye in vivo with optical coherence tomography
Authors: Choi Woo J. , Pepple Kathryn L. , Wang Ruikang K.
Published: May 2018

In preclinical vision research, cell grading in small animal models is essential for the quantitative evaluation of intraocular inflammation. Here, we present a new and practical optical coherence tomography (OCT) image analysis method for the automated detection and counting of aqueous cells in the anterior chamber (AC) of a rodent model of uveitis. Anterior segment OCT images are acquired with a 100 kHz swept‐source OCT system. The proposed method consists of 2 steps. In the first step, we first despeckle and binarize each OCT image. After removing AS structures in the binary image, we then apply area thresholding to isolate cell‐like objects. Potential cell candidates are selected based on their best fit to roundness. The second step performs the cell counting within the whole AC, in which additional cell tracking analysis is conducted on the successive OCT images to eliminate redundancy in cell counting. Finally, 3D cell grading using the proposed method is demonstrated in longitudinal OCT imaging of a mouse model of anterior uveitis in vivo. Rendering of anterior segment (orange) of mouse eye and automatically counted anterior chamber cells (green). Inset is a top view of the rendering, showing the cell distribution across the anterior chamber.
Using poly(l‐lactic acid) and poly(ɛ‐caprolactone) blends to fabricate self‐expanding, watertight and biodegradable surgical patches for potential fetoscopic myelomeningocele repair
Authors: Tatu Rigwed , Oria Marc , Pulliam Sarah , Signey Lorenzo , Rao Marepalli B. , Peiro Jose L. , Lin Chia‐Ying
Published: May 2018

Our study focuses on the development and characterization of a self‐expanding, watertight and biodegradable patch for fetoscopic myelomeningocele (MMC) prenatal repair. We fabricated poly(l‐lactic acid) (PLA) and poly(ɛ‐caprolactone) (PCL) blend films by solution casting. Formulation c with average glass transition temperature of 37.6 ± 1.2°C was chosen for temporospatial recovery. Favorable results from surface studies reflected homogeneous dispersion of polymers in the blend. The cytotoxicity was studied in human foreskin fibroblasts. The blend film was cytocompatible, evidenced by matching percentage of live cells in exposed and control solutions. Subsequently, liquid water permeability experiments confirmed watertight nature of films. Finally, in vitro degradation was investigated in phosphate buffered saline (PBS) and amniotic fluid (AF) separately for 16 weeks. Similar weight loss (n = 6, p = 0.912) and significantly different (n = 3, p = 0.025) surface roughness was observed in PBS and AF, respectively, at 16 weeks. Functional group analysis displayed increasing carbonyl and hydroxyl bonds in PBS and AF, respectively, over time, indicating progression of hydrolytic degradation. Favorable characterization results provide strong evidence to employ PLA‐PCL blend films as surgical patches in fetoscopic MMC repair. Designed patch serves as standalone system to successfully tackle impending hurdles of MMC repair and proves to be a superior alternative compared to existing patches. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 295–305, 2019.
What is the role of sense of community in multiracial societies? A contribution to the community–diversity dialectic: A genetic psychology approach
Authors: Rochira Alessia
Published: May 2018

Interconnecting the construct of sense of community (SOC), elaborated by McMillan and Chavis, with the notion of social representations, elaborated by Moscovici, this article aims to contribute to advancing an understanding of the relationship between SOC and respect for diversity. Utilizing a genetic psychology approach and the intergroup contact theory, the article articulates 3 levels through which the social representation of community and SOC can be formed and transformed (i.e., microgenetic, ontogenetic, and sociogenetic) to enhance the investigation of the relationship between the 2 phenomena beyond the intraindividual and interindividual levels that tend to emphasize homophily, or preference for similarity. In particular, the article elaborates on the sociogenetic formation of SOC by examining the macro‐level forces that participate in establishing what a community should be and who is entitled to be part of it. Examples from 2 previous studies are discussed.
Clinical evaluation of Roche COBAS® AmpliPrep/COBAS® TaqMan® CMV test using nonplasma samples
Authors: Hildenbrand Cynthia , Wedekind Laura , Li Ge , vonRentzell Jeanne E. , Shah Krunal , Rooney Paul , Harrington Amanda T. , Zhao Richard Y.
Published: May 2018

Cytomegalovirus (CMV) infection is a leading cause of loss of hearing, vision, and mental retardation in congenitally infected children. It is also associated with complications of organ transplant and opportunistic HIV coinfection. The Roche COBAS® AmpliPrep/COBAS® TaqMan® CMV test is an FDA–approved test that measures CMV DNA viral load in plasma for the diagnosis and management of patients at risk of CMV‐associated diseases. Besides plasma, CMV is often found in bronchoalveolar lavage (BAL), cerebrospinal fluid (CSF), and urine. Thus, monitoring of CMV for critical care of patients in these nonplasma samples becomes necessary. The objective of this study was to conduct an analytic and clinical feasibility study of the Roche CMV test in BAL, CSF, and urine. The lower limit of detection, analytic measurement range, assay sensitivity, specificity, and precision were determined. Results of this study showed that the lower limit of detections were 50, 100, and 300 IU/mL for BAL, CSF, or urine, respectively. The analytic measurement ranges were from log10 2.48 to log10 5.48. The assay specificity was 94.4% for BAL and 100% for CSF and urine. The assay precision was all within the acceptable range. The performance of Roche test was further compared with 2 comparators including the RealTime CMV assay (Abbott Molecular) and a CMV Quantitative Polymerase Chain Reaction test (Vela Diagnostics). There was a general positive correlation between the Roche method and the Abbott or the Vela method. Overall, this study suggests that the Roche CMV test is suitable for the quantification of CMV viral load DNA in the described nonplasma samples.
Integration of hepatitis B virus DNA in chronically infected patients assessed by Alu‐PCR
Authors: Larsson Simon B. , Tripodi Gianluca , Raimondo Giovanni , Saitta Carlo , Norkrans Gunnar , Pollicino Teresa , Lindh Magnus
Published: May 2018

Hepatitis B virus (HBV) infection is the main risk factor for hepatocellular carcinoma (HCC) worldwide. Integration of HBV DNA into the human genome has been found in >80% of HBV‐related HCC cases. Some studies have, however, found similar integration patterns in tumorous and nontumorous tissues. Thus, the role of integrations for the development of HCC as well as the rate of integration in different stages of infection remain unclear. The aim of this study was to investigate integrations in patients without HCC, representing different stages of chronic HBV (CHB) infection. Extracted DNA in liver biopsies from 74 patients (one with 2 available biopsies) with CHB infection was analyzed by Alu‐PCR. Amplicons were further analyzed by Sanger sequencing. Integration was detected in 39 biopsies (52%) as an amplicon containing both human and HBV sequences by Alu‐PCR with one primer targeting a region in the HBV genome. Integrations were found in patients representing the different stages of CHB infection. A majority of the HBV sequences were located upstream or downstream of nucleotide position 1820, which previously has been identified as a common breakpoint in the HBV genome in integrated sequences. Approximately 60% of the HBV integrations were found in noncoding regions of the human genome. Integrations of HBV DNA into the human genome is an event frequently found in mild phases of chronic hepatitis.
Fusarium species and moniliformin occurrence in sorghum grains used as ingredient for animal feed in Argentina
Authors: Pena Gabriela A , Cavaglieri Lilia R , Chulze Sofía N
Published: May 2018

BACKGROUND

A survey on Fusarium species and moniliformin (MON) occurrence in sorghum grains collected from one of the main sorghum‐producing areas of Argentina was conducted. Also, growth of F. thapsinum, one of the main sorghum pathogens, and MON production under different water activity (aw) conditions on a sorghum‐based medium were determined.

RESULTS

Infection of sorghum grains by Fusarium species ranged from 82.5 to 99%; closely related species F. verticillioides, F. thapsinum and F. andiyazi were the most frequently recovered, followed by F. proliferatum and F. subglutinans. By sequencing a portion of the translation elongation factor‐1α (TEF‐1α) gene and by maximum parsimony analysis, F. verticillioides and closely related species were identified as F. thapsinum, F. andiyazi and F. verticillioides. Species within the F. graminearum species complex (FGSC) were isolated in high frequency. Maximum growth rates of 12 F. thapsinum strains were obtained at 0.995 aw. All evaluated strains were able to produce MON at all aw values tested, but MON production was higher at 0.995–0.982 aw. MON was detected in 41% of the samples at levels ranging from 363.2 to 914.2 µg kg−1.

CONCLUSION

This study provides new data on the occurrence of Fusarium species in sorghum grains destined for animal consumption in Argentina. The production of MON at different aw values showed that the toxin can be produced under field conditions. The risk to livestock exposed to daily low levels of MON associated with the toxin occurrence in the sorghum grains analyzed is unknown. © 2018 Society of Chemical Industry
Identification of Correlative Shifts in Indices of Brain Cholesterol Metabolism in the C57BL6/Mecp2tm1.1Bird Mouse, a Model for Rett Syndrome
Authors: Lütjohann Dieter , Lopez Adam M. , Chuang Jen‐Chieh , Kerksiek Anja , Turley Stephen D.
Published: May 2018

Rett syndrome (RS) is a pervasive neurodevelopmental disorder resulting from loss‐of‐function mutations in the X‐linked gene methyl‐Cpg‐binding protein 2 (MECP2). Using a well‐defined model for RS, the C57BL6/Mecp2tm1.1Bird mouse, we have previously found a moderate but persistently lower rate of cholesterol synthesis, measured in vivo, in the brains of Mecp2−/y mice, starting from about the third week after birth. There was no genotypic difference in the total cholesterol concentration throughout the brain at any age. This raised the question of whether the lower rate of cholesterol synthesis in the mutants was balanced by a fall in the rate at which cholesterol was converted via cholesterol 24‐hydroxylase (Cyp46A1) to 24S‐hydroxycholesterol (24S‐OHC), the principal route through which cholesterol is ordinarily removed from the brain. Here, we show that while there were no genotypic differences in the concentrations in plasma and liver of three cholesterol precursors (lanosterol, lathosterol, and desmosterol), two plant sterols (sitosterol and campesterol), and two oxysterols (27‐hydroxycholesterol [27‐OHC] and 24S‐OHC), the brains of the Mecp2
−/y mice had significantly lower concentrations of all three cholesterol precursors, campesterol, and both oxysterols, with the level of 24S‐OHC being ~20% less than in their Mecp2
+/y controls. Together, these data suggest that coordinated regulation of cholesterol synthesis and catabolism in the central nervous system is maintained in this model for RS. Furthermore, we speculate that the adaptive changes in these two pathways conceivably resulted from a shift in the permeability of the blood–brain barrier as implied by the significantly lower campesterol and 27‐OHC concentrations in the brains of the Mecp2−/y mice.
Atmospheric corrosion study in a harbor located in a tropical island
Authors: Castañeda Abel , Valdés Cecilia , Corvo Francisco
Published: May 2018

Atmospheric corrosion level in tropical coastal zones is usually very significant. Corrosion control and preservation of infrastructure in these regions is very important to increase durability. Atmospheric corrosion of carbon steel, copper, galvanized steel, and aluminum was evaluated in a coastal industrial port zone located in a tropical island during 1 year. Samples were exposed at seven outdoor corrosion sites located at different distances from the sea. Main atmospheric pollutants, relative humidity, and air temperature were monitored during the exposure time. The existence of a combination between two of the most aggressive atmosphere types was determined (coastal‐industrial and industrial‐coastal). Changes in RH and temperature influenced significantly the chloride deposition. A new statistical model to explain the influence of time of exposure for all metals tested was developed. A possible antagonist effect between pollutants on corrosion may be possible. Acceleration of corrosion rate vs time is observed in the site close to the shoreline. Significant differences between corrosivity categories determined and those calculated by ISO standard dose response functions were found. The narrow entrance of the harbor with low movement of the inner water causes a decrease in salinity in the port zone.
Influence of austenitizing and tempering on the corrosion behavior and sensitization of martensitic stainless steel X50CrMoV15
Authors: Babutzka Martin , Heyn Andreas , Rosemann Paul
Published: May 2018

Electrochemical tests, hardness measurements, and microstructure analysis are performed to study the influence of austenitizing, quenching, and tempering parameters on the corrosion resistance of the martensitic stainless steel grade X50CrMoV15 (1.4116). Different heat treatment states were studied using an adapted EPR‐Test to evaluate the chromium distribution and depletion caused by the formation and dissolution of chromium rich carbides. The EPR results were correlated with pitting corrosion behavior, demonstrating the strong effect of heat treatment parameters on the susceptibility of martensitic stainless steels to corrosion phenomena.
Chemically Enhanced Wet‐Spinning Process to Accelerate Thermal Stabilization of Polyacrylonitrile Fibers
Authors: Fakhrhoseini Seyed Mousa , Khayyam Hamid , Naebe Minoo
Published: May 2018

In this study, a fast and inexpensive approach is introduced to assist stabilization of polyacrylonitrile (PAN) fibers by adding ammonium iron(II) sulfate in coagulation bath. Effects of chemical treatment on stabilization process and structural evolution of fibers are studied using calorimetric, infrared, and X‐ray techniques. A stepwise infrared study confirms the assisted cyclization reaction, and an X‐ray analysis reveals a significant improvement in crystallinity and orientation of polymer chains which lead to an increase in tensile strength and modulus of PAN fibers. Differential scanning calorimetry results show 13 °C reductions in peak temperature of the stabilization reaction which means a sign of chemical activation at lower temperature by adding sulfate ions. Quantification of IR spectra shows a 7% increase in extent of reaction of chemically treated fibers and higher degree of conjugation compared with untreated and post‐treated fibers. Finally, mechanical properties of chemically treated fibers are improved due to an increase in size and orientation of polymer chains after chemical treatment in the coagulation bath. Compared to control and post‐treated PAN fibers, thermochemical properties of presented fibers are improved due to chemically assisted stabilization, and as a consequence, energy consumption of the stabilization step will be reduced by a simple and facile treatment.
Rex in Caldicellulosiruptor bescii: Novel regulon members and its effect on the production of ethanol and overflow metabolites
Authors: Sander Kyle , Chung Daehwan , Hyatt Doug , Westpheling Janet , Klingeman Dawn M. , Rodriguez Miguel , Engle Nancy L. , Tschaplinski Timothy J. , Davison Brian H. , Brown Steven D.
Published: May 2018

Rex is a global redox‐sensing transcription factor that senses and responds to the intracellular [NADH]/[NAD+] ratio to regulate genes for central metabolism, and a variety of metabolic processes in Gram‐positive bacteria. We decipher and validate four new members of the Rex regulon in Caldicellulosiruptor bescii; a gene encoding a class V aminotransferase, the HydG FeFe Hydrogenase maturation protein, an oxidoreductase, and a gene encoding a hypothetical protein. Structural genes for the NiFe and FeFe hydrogenases, pyruvate:ferredoxin oxidoreductase, as well as the rex gene itself are also members of this regulon, as has been predicted previously in different organisms. A C. bescii rex deletion strain constructed in an ethanol‐producing strain made 54% more ethanol (0.16 mmol/L) than its genetic parent after 36 hr of fermentation, though only under nitrogen limited conditions. Metabolomic interrogation shows this rex‐deficient ethanol‐producing strain synthesizes other reduced overflow metabolism products likely in response to more reduced intracellular redox conditions and the accumulation of pyruvate. These results suggest ethanol production is strongly dependent on the native intracellular redox state in C. bescii, and highlight the combined promise of using this gene and manipulation of culture conditions to yield strains capable of producing ethanol at higher yields and final titer.
Serial passage through resistant and susceptible cucumber cultivars affects the virulence of Fusarium oxysporum f. sp. cucumerinum
Authors: Huang Xiaoqing , Sun Manhong , Lu Xiaohong , Li Shidong
Published: May 2018

Fusarium oxysporum f. sp. cucumerinum (Foc) is the causal pathogen of cucumber Fusarium wilt resulting in losses to cucumber production. To investigate the effects of the selective pressures of host plants on the virulence of Foc, a low virulence isolate, foc‐3b, was successively inoculated on resistant and susceptible cucumber cultivars for five generations. The virulence of the original isolate diverged; virulence was significantly strengthened after serial passage on the resistant cultivar and weakened on the susceptible plants (p ˂ .05). The expression of four virulence‐related genes of F. oxysporum, G‐protein α subunit gene fga1, sucrose nonfermenting 1 gene snf1, F‐box protein gene frp1, and Class V chitin synthase gene chsV, was quantified using real‐time PCR. All genes were significantly upregulated after serial passage on the resistant cultivar, compared to the original strain, and the expression of snf1 was downregulated in strains re‐isolated from the susceptible plants (p ˂ .05). A significant positive correlation was found between the expression levels of gene snf1, frp1, and chsV and disease severity of cucumber Fusarium wilt, suggesting these genes may impact virulence differentiation. This study will improve the management of cucumber Fusarium wilt and provide insight into the mechanisms underlying virulence of F. oxysporum.
Heterogeneity of plural forms: A revised transaction cost approach
Authors: Schnaider Paula Sarita Bigio , Ménard Claude , Saes Maria Sylvia Macchione
Published: May 2018

Strategies pushing firms to adopt plural forms and the heterogeneity of solutions they endorse have attracted increasing attention. This paper proposes a theoretical framework that combines asset specificity and uncertainty toexplainwhy there are plural forms and focuses on the key role of uncertainty, within a given range of asset specificity, topredictwhat and when specific types of plural forms should be observed. Propositions derived from this model are tested on an extensive set of cases from the agribusiness sector. The empirical richness of these cases allows going beyond the existing literature, which has essentially focused on franchising.
Whole‐exome sequencing for variant discovery in blepharospasm
Authors: Tian Jun , Vemula Satya R. , Xiao Jianfeng , Valente Enza Maria , Defazio Giovanni , Petrucci Simona , Gigante Angelo Fabio , Rudzińska‐Bar Monika , Wszolek Zbigniew K. , Kennelly Kathleen D. , Uitti Ryan J. , van Gerpen Jay A. , Hedera Peter , Trimble Elizabeth J. , LeDoux Mark S.
Published: May 2018

Background

Blepharospasm (BSP) is a type of focal dystonia characterized by involuntary orbicularis oculi spasms that are usually bilateral, synchronous, and symmetrical. Despite strong evidence for genetic contributions to BSP, progress in the field has been constrained by small cohorts, incomplete penetrance, and late age of onset. Although several genetic etiologies for dystonia have been identified through whole‐exome sequencing (WES), none of these are characteristically associated with BSP as a singular or predominant manifestation.

Methods

We performed WES on 31 subjects from 21 independent pedigrees with BSP. The strongest candidate sequence variants derived from in silico analyses were confirmed with bidirectional Sanger sequencing and subjected to cosegregation analysis.

Results

Cosegregating deleterious variants (GRCH37/hg19) in CACNA1A (NM_001127222.1: c.7261_7262delinsGT, p.Pro2421Val), REEP4 (NM_025232.3: c.109C>T, p.Arg37Trp), TOR2A (NM_130459.3: c.568C>T, p.Arg190Cys), and ATP2A3 (NM_005173.3: c.1966C>T, p.Arg656Cys) were identified in four independent multigenerational pedigrees. Deleterious variants in HS1BP3 (NM_022460.3: c.94C>A, p.Gly32Cys) and GNA14 (NM_004297.3: c.989_990del, p.Thr330ArgfsTer67) were identified in a father and son with segmental cranio‐cervical dystonia first manifest as BSP. Deleterious variants in DNAH17, TRPV4, CAPN11, VPS13C, UNC13B, SPTBN4, MYOD1, and MRPL15 were found in two or more independent pedigrees. To our knowledge, none of these genes have previously been associated with isolated BSP, although other CACNA1A mutations have been associated with both positive and negative motor disorders including ataxia, episodic ataxia, hemiplegic migraine, and dystonia.

Conclusions

Our WES datasets provide a platform for future studies of BSP genetics which will demand careful consideration of incomplete penetrance, pleiotropy, population stratification, and oligogenic inheritance patterns.
A photon source model based on particle transport in a parameterized accelerator structure for Monte Carlo dose calculations
Authors: Ishizawa Yoshiki , Dobashi Suguru , Kadoya Noriyuki , Ito Kengo , Chiba Takahito , Takayama Yoshiki , Sato Kiyokazu , Takeda Ken
Published: May 2018

Purpose

An accurate source model of a medical linear accelerator is essential for Monte Carlo (MC) dose calculations. This study aims to propose an analytical photon source model based on particle transport in parameterized accelerator structures, focusing on a more realistic determination of linac photon spectra compared to existing approaches.

Methods

We designed the primary and secondary photon sources based on the photons attenuated and scattered by a parameterized flattening filter. The primary photons were derived by attenuating bremsstrahlung photons based on the path length in the filter. Conversely, the secondary photons were derived from the decrement of the primary photons in the attenuation process. This design facilitates these sources to share the free parameters of the filter shape and be related to each other through the photon interaction in the filter. We introduced two other parameters of the primary photon source to describe the particle fluence in penumbral regions. All the parameters are optimized based on calculated dose curves in water using the pencil‐beam–based algorithm. To verify the modeling accuracy, we compared the proposed model with the phase space data (PSD) of the Varian TrueBeam 6 and 15 MV accelerators in terms of the beam characteristics and the dose distributions. The EGS5 Monte Carlo code was used to calculate the dose distributions associated with the optimized model and reference PSD in a homogeneous water phantom and a heterogeneous lung phantom. We calculated the percentage of points passing 1D and 2D gamma analysis with 1%/1 mm criteria for the dose curves and lateral dose distributions, respectively.

Results

The optimized model accurately reproduced the spectral curves of the reference PSD both on‐ and off‐axis. The depth dose and lateral dose profiles of the optimized model also showed good agreement with those of the reference PSD. The passing rates of the 1D gamma analysis with 1%/1 mm criteria between the model and PSD were 100% for 4 × 4, 10 × 10, and 20 × 20 cm2 fields at multiple depths. For the 2D dose distributions calculated in the heterogeneous lung phantom, the 2D gamma pass rate was 100% for 6 and 15 MV beams. The model optimization time was less than 4 min.

Conclusion

The proposed source model optimization process accurately produces photon fluence spectra from a linac using valid physical properties, without detailed knowledge of the geometry of the linac head, and with minimal optimization time.
Evaluating blood clot progression using magnetic particle spectroscopy
Authors: Khurshid Hafsa , Shi Yipeng , Berwin Brent L. , Weaver John B.
Published: May 2018

Purpose

To evaluate the thrombus maturity noninvasively providing the promise of much earlier and more accurate diagnosis of diseases ranging from stroke to myocardial infarction to deep vein thrombosis.

Methods

Magnetic spectroscopy of nanoparticle Brownian rotation (MSB), a form of magnetic particle spectroscopy sensitive to Brownian rotation of magnetic nanoparticles, was used for the detection and characterization of blood clots. The nanoparticles’ relaxation time was quantified by scaling the MSB spectra in frequency to match the spectra from nanoparticles in a reference state. The nanoparticles’ relaxation time, in the bound state, was used to characterize the nanoparticle binding to thrombin on the blood clot. The number of nanoparticles bound to the clot was also estimated. Both the relaxation time and the weight of bound nanoparticles were obtained for clots of several ages, reflecting different stages of development and organization. The impact of clot development was explored using functionalized nanoparticles present during clot formation.

Results

The relaxation time of the bound nanoparticles decreases for more mature, organized clots. The number of nanoparticles able to bind the clot diminishes quantitatively with clot age. On mature clots, the nanoparticles bind the thrombin on the surface while for developing clots the nanoparticles bind several thrombin molecules or become trapped in the clot matrix during formation.

Conclusions

By estimating the magnetic nanoparticles’ relaxation time the clot age and organization can be predicted. The purposed methods are quick and minimally invasive for in vivo applications.
Interaction between cyanine dye IR‐783 and polystyrene nanoparticles in solution
Authors: Zhang Yunzhi , Xu Hui , Casabianca Leah B.
Published: May 2018

The interactions between small molecule drugs or dyes and nanoparticles are important to the use of nanoparticles in medicine. Noncovalent adsorption of dyes on nanoparticle surfaces is also important to the development of nanoparticle dual‐use imaging contrast agents. In this work, solution‐state NMR is used to examine the noncovalent interaction between a near‐infrared cyanine dye and the surface of polystyrene nanoparticles in solution. Using 1D proton NMR, we can approximate the number of dye molecules that associate with each nanoparticle for different sized nanoparticles. Saturation‐Transfer Difference NMR was also used to show that protons near the positively charged nitrogen in the dye are more strongly associated with the negatively charged nanoparticle surface than protons near the negatively charged sulfate groups of the dye. The methods described here can be used to study similar drug or dye molecules interacting with the surface of organic nanoparticles.
A novel phase‐unwrapping method by using phase‐jump detection and local surface fitting: application to Dixon water–fat MRI
Authors: Cheng Junying , Guan Jijing , Mei Yingjie , Xu Lin , Liu Xiaoyun , Feng Qianjin , Chen Wufan , Feng Yanqiu
Published: May 2018

Purpose

This study aims to develop an accurate and robust phase‐unwrapping method that works effectively under severe noise, rapid‐varying phase, and disconnected regions for water–fat Dixon MRI.

Methods

The proposed method first segments the phase map into blocks by automatically detecting phase jumps, and then clusters the pixels near phase jumps into residual pixels. Thereafter, the proposed method sequentially performs intrablock, interblock, and residual‐pixel unwrapping using the local surface fitting approach. To address intrablock wraps, the proposed method segments each block into subblocks using the phase partition approach and then performs inter‐subblock unwrapping using a block‐growing approach. The phase derivative variance is used as the quality criterion to determine the region‐growing path of residual pixels. The performance of the proposed method was evaluated on simulation and in vivo Dixon data.

Results

The proposed method obtained accurate phase‐unwrapping results in the simulation experiment with severe noise, rapid‐varying phase, and disconnected regions, and the mean and SD error ratio was 0.26 ± 0.07%. For 505 in vivo knee and ankle images, the total water–fat swap ratio by the proposed method was 1.78%, whereas those by phase region expanding labeler for unwrapping discrete estimates and clustering and local surface fitting were 38.42% and 7.72%, respectively.

Conclusion

The proposed method achieves accurate and robust performance in phase unwrapping and can benefit phase‐related MRI applications such as Dixon water–fat separation.
Functional magnetic resonance electrical impedance tomography (fMREIT) sensitivity analysis using an active bidomain finite‐element model of neural tissue
Authors: Sadleir Rosalind J. , Fu Fanrui , Chauhan Munish
Published: May 2018

Purpose

A direct method of imaging neural activity was simulated to determine typical signal sizes.

Methods

An active bidomain finite‐element model was used to estimate approximate perturbations in MR phase data as a result of neural tissue activity, and when an external MR electrical impedance tomography imaging current was added to the region containing neural current sources.

Results

Modeling‐predicted, activity‐related conductivity changes should produce measurable differential phase signals in practical MR electrical impedance tomography experiments conducted at moderate resolution at noise levels typical of high field systems. The primary dependence of MR electrical impedance tomography phase contrast on membrane conductivity changes, and not source strength, was demonstrated.

Conclusion

Because the injected imaging current may also affect the level of activity in the tissue of interest, this technique can be used synergistically with neuromodulation techniques such as deep brain stimulation, to examine mechanisms of action.
A numerical scheme to the McKendrick–von Foerster equation with diffusion in age
Authors: Kakumani Bhargav Kumar , Tumuluri Suman Kumar
Published: May 2018

In this paper a numerical scheme for McKendrick–von Foerster equation with diffusion in age (MV‐D) is proposed. First, we discretize the time variable to get a second‐order ordinary differential equation (ODE). At each time level, well‐posedness of this ODE is established using classical methods. Stability estimates for this semidiscrete scheme are derived. Later we construct piecewise linear (in time) functions using the solutions of the semidiscrete problems to approximate the solution to MV‐D and establish the convergence result. Numerical results are presented in some cases and compared with the corresponding analytic solutions where the latter is known explicitly.
Surface‐initiated atom transfer radical polymerization of a new rhodanine‐based monomer for rapid magnetic removal of Co(II) ions from aqueous solutions
Authors: Rahmaninia Arman , Mansoori Yagoub , Nasiri Farough
Published: May 2018

The present study reports synthesis and characterization of a new acrylamide‐based monomer containing rhodanine moiety, N‐3‐amino‐thiazolidine‐4‐one‐acrylamide (ATA). Poly(ATA)‐grafted magnetite nanoparticles (poly(ATA)‐g‐MNPs) were prepared using surface‐initiated atom transfer radical polymerization of the monomer on Fe3O4 nanoparticles. The grafted nanoparticles were characterized by Fourier transform infrared analysis, scanning electron microscopy, X‐ray diffraction, and vibrating sample magnetometry. The amount of the grafted polymer was 209 mg g−1, as calculated from thermogravimetric analysis experiment. The capability of poly(ATA)‐g‐MNPs to remove Co(II) cations was shown under optimal conditions of contact time, pH, adsorbent dosage, and initial Co(II) concentration. About 86% of the Co(II) cations were removed over 7 minutes. The adsorption kinetics obeyed the pseudo–second‐order kinetic equation, and the Langmuir isotherm model best described the adsorption isotherm with a maximum adsorption capacity of 3.62 mg g−1. The thermodynamic investigation showed spontaneous nature of the adsorption process (ΔG = −2.90 kJ mol−1 at 25°C ± 1°C). In addition, the poly(ATA)‐g‐MNPs were regenerated by simply washing with an aqueous 0.1M HCl solution. The study of the reusability of the prepared magnetic sorbent revealed that the sorbent can be reused without a significant decrease in the extraction efficiency and be recovered by 95.4% after 7 cycles. These findings suggest that the grafted nanoparticles are stable and reusable adsorbent and can be potentially applied to water treatment in efficient removal of Co(II) cations.
Mandibular growth in survivors of pediatric parotid gland carcinoma treated with interstitial brachytherapy
Authors: Wu Wen‐Jie , Huang Ming‐Wei , Zhang Guo‐Hao , Zhao Dan , Zheng Lei , Yu Guang‐Yan , Zhang Jian‐Guo
Published: May 2018

Background

The aim of the study was to present long‐term results of mandibular growth in pediatric parotid gland carcinoma survivors treated with interstitial brachytherapy.

Procedure

Twenty‐five survivors of pediatric parotid gland carcinoma treated with iodine‐125 seed interstitial brachytherapy were included for quantitative analysis, including three dimensional (3D) cephalometry and measurement of mandibular volume.

Results

3D cephalometry showed that the median fore‐and‐aft increments of the lengths of the condyle, the ramus, and the body of the mandible were 1.23, 0.19, and 1.66 mm for the affected side, respectively, and were 1.37, 1.95, and 3.42 mm for the unaffected side, respectively. The difference in increments of the ramus was statistically significant between the affected side and the unaffected side (P = 0.003; P < 0.05). Moreover, mandibular volume measurements showed that the median fore‐and‐aft increments of the volumes of the condyle, the ramus, and the body of the mandible were 290.62, 220.14, and 1706.40 mm3 for the affected side, respectively, and were 269.15, 370.40, and 1469.86 mm3 for the unaffected side, respectively. The difference in increments was statistically significant between the affected side and the unaffected side for the ramus (P = 0.005; P < 0.05) and the body (P = 0.043; P < .05).

Conclusion

Mandibular growth was affected by interstitial brachytherapy, especially for the ramus, in pediatric parotid gland carcinoma survivors treated with interstitial brachytherapy. Nevertheless, the impact was mild in these survivors.
Psychosocial determinants of physical activity and dietary behaviors in adolescents and young adults with cancer and survivors
Authors: Diorio Caroline , Lin Meiko , Ginn Elizabeth , Ladas Elena J.
Published: May 2018

Background

Survivors of childhood cancer are at increased risk of lifestyle influenced health issues. We sought to understand the association between stages of change (SOC) and psychosocial variables related to modifiable health behaviors: physical activity (PA), dietary fat intake, and intake of fruits and vegetables among adolescents and young adults at different phases of cancer therapy.

Methods

We conducted an exploratory cross‐sectional survey of adolescents and young adults currently being treated for cancer or who are survivors of childhood cancer. We evaluated SOC and several psychosocial variables using the previously validated Patient‐Centered Assessment and Counseling for Exercise (PACE+): Physical Activity and Diet Surveys for Adolescents tool. Current dietary behaviors were evaluated with 24 hr diet recall.

Results

One hundred and eighteen patients participated in the survey. SOC did not vary by phase of treatment. Ethnicity and body mass index were strongly associated with SOC for PA, but not for dietary behaviors. There was a significant association between SOC and self‐efficacy, knowledge of strategies, and family or friend support for PA, dietary fat, and fruits and vegetables. Higher self‐efficacy and family support were significant variables impacting SOC and participants’ reported intake of fruits and vegetables servings.

Conclusion

We demonstrate that SOC for the investigated behaviors did not change based on phase of treatment, supporting the initiation of lifestyle interventions early on in treatment. We identify several psychosocial variables that may act as important targets for future lifestyle interventions aimed to improve dietary and exercise behaviors in adolescents and young adults with cancer and survivors.
Gemcitabine/nab‐paclitaxel for pediatric relapsed/refractory sarcomas
Authors: Metts Jonathan L. , Alazraki Adina L. , Clark Dana , Amankwah Ernest K. , Wasilewski‐Masker Karen J. , George Bradley A. , Olson Thomas A. , Cash Thomas
Published: May 2018

Background

Pediatric patients with relapsed/refractory sarcomas have poor outcomes and need novel therapies that provide disease control while maintaining an acceptable quality of life. The activity and toxicity of gemcitabine and nab‐paclitaxel in combination has not been reported in pediatrics.

Procedure

We reviewed the records of fifteen relapsed/refractory patients and one treatment‐naïve patient who received gemcitabine/nab‐paclitaxel at our institution.

Results

Sixteen patients (median age 13.5 years, range 3–19 years) received 53 cycles of gemcitabine/nab‐paclitaxel. Twenty‐nine cycles (55%) resulted in ≥Grade 3 toxicity, with nonhematologic Grade ≥3 toxicities occurring in only eight of 53 cycles (15%). Patients received red blood cell and platelet transfusions in 23% and 4% of cycles, respectively. Grade ≥3 infectious toxicities occurred in 4% of cycles. Of 14 patients with measurable disease, there were no complete responses (CR), one partial response (PR; 7%), and six patients (43%) with stable disease (SD; median SD: 4.5 months, range: 2–19 months). In total, 31% of the patients derived clinical benefit (CR + PR + SD ≥ 4 months). Median time to progression was 72 days with a 4‐month progression‐free survival of 31% ± 12% and 1‐year overall survival of 19% ± 10%. With a median follow‐up for all 16 patients of 21 months from the first treatment with gemcitabine/nab‐paclitaxel, one (6%) remains alive with disease.

Conclusions

Gemcitabine/nab‐paclitaxel is a relatively safe regimen with mainly hematologic toxicities. It offers a well‐tolerated, palliative option providing clinical benefit in a subset of patients. A phase I trial of this combination is underway.