bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulating local S1P receptor signaling as a regenerative immunotherapy after volumetric muscle loss injury
Authors: Hymel Lauren A. , Ogle Molly E. , Anderson Shannon E. , San Emeterio Cheryl L. , Turner Thomas C. , York William Y. , Liu Alan Y. , Olingy Claire E. , Sridhar Sraeyes , Lim Hong Seo , Sulchek Todd , Qiu Peng , Jang Young C. , Willett Nick J. , Botchwey Edward A.
Published: July 2020

Regeneration of skeletal muscle after volumetric injury is thought to be impaired by a dysregulated immune microenvironment that hinders endogenous repair mechanisms. Such defects result in fatty infiltration, tissue scarring, chronic inflammation, and debilitating functional deficits. Here, we evaluated the key cellular processes driving dysregulation in the injury niche through localized modulation of sphingosine‐1‐phosphate (S1P) receptor signaling. We employ dimensionality reduction and pseudotime analysis on single cell cytometry data to reveal heterogeneous immune cell subsets infiltrating preclinical muscle defects due to S1P receptor inhibition. We show that global knockout of S1P receptor 3 (S1PR3) is marked by an increase of muscle stem cells within injured tissue, a reduction in classically activated relative to alternatively activated macrophages, and increased bridging of regenerating myofibers across the defect. We found that local S1PR3 antagonism via nanofiber delivery of VPC01091 replicated key features of pseudotime immune cell recruitment dynamics and enhanced regeneration characteristic of global S1PR3 knockout. Our results indicate that local S1P receptor modulation may provide an effective immunotherapy for promoting a proreparative environment leading to improved regeneration following muscle injury.
Are the Relationships of Lean Mass and Fat Mass With Bone Microarchitecture Causal or Due to Familial Confounders? A Novel Study of Adult Female Twin Pairs
Authors: Bui Minh , Zebaze Roger , Li Shuai , Hopper John L , Bjørnerem Åshild
Published: July 2020

It is not known whether the relationships of lean mass (LM) and fat mass (FM) with bone microarchitecture and geometry are causal and/or are because of confounders, including familial confounders arising from genetic and environment effects shared by relatives. We tested the hypotheses that: (i) LM is associated with cortical bone traits, (ii) FM is associated with trabecular bone traits, and (iii) these relationships of LM and FM with bone microarchitecture and geometry have a causal component. Total body composition was quantified for 98 monozygotic (MZ) and 54 dizygotic (DZ) white female twin pairs aged 31 to 77 years. Microarchitecture at the distal tibia and distal radius was quantified using HRpQCT and StrAx software. We applied the Inference about Causation through Examination of FAmiliaL CONfounding (ICE FALCON) method. Within‐individuals, distal tibia total bone area, cortical area, cortical thickness, and trabecular number were positively associated with LM (standardized regression coefficient (β) = 0.13 to 0.43; all p < 0.05); porosity of the inner transitional zone (ITZ) was negatively associated with LM (β = −0.22; p < 0.01). Trabecular number was positively associated with FM (β = 0.40; p < 0.001), and trabecular thickness was negatively associated with FM (β = −0.27; p < 0.001). For porosity of ITZ and trabecular number, the cross‐pair cross‐trait association with LM was significant before and after adjustment for the within‐individual association with LM (all ps < 0.05). For trabecular number, the cross‐pair cross‐trait association with FM was significant before and after adjustment for the within‐individual association with FM (p < 0.01). There were no significant changes in these cross‐pair cross‐trait associations after adjustment for the within‐individual association (p = 0.06 to 0.99). Similar results were found for distal radius measures. We conclude that there was no evidence that the relationships of LM and FM with bone microarchitecture and geometry are causal; they must in part due to by familial confounders affecting both bone architecture and body composition. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
The reliability of a breath‐hold protocol to determine cerebrovascular reactivity in adolescents
Authors: Koep Jodie L. , Barker Alan R. , Banks Rhys , Banger Rohit R. , Sansum Kate M. , Weston Max E. , Bond Bert
Published: July 2020

Purpose

Cerebrovascular reactivity (CVR) is impaired in adolescents with cardiovascular disease risk factors. A breath‐hold test is a noninvasive method of assessing CVR, yet there are no reliability data of this outcome in youth. This study aimed to assess the reliability of a breath‐hold protocol to measure CVR in adolescents.

Methods

Twenty‐one 13 to 15 year old adolescents visited the laboratory on two separate occasions, to assess the within‐test, within‐day and between‐day reliability of a breath‐hold protocol, consisting of three breath‐hold attempts. CVR was defined as the relative increase from baseline in middle cerebral artery mean blood velocity following a maximal breath‐hold of up to 30 seconds, quantified via transcranial Doppler ultrasonography.

Results

Mean breath‐hold duration and CVR were never significantly correlated (r< .31,P> .08). The within‐test coefficient of variation for CVR was 15.2%, with no significant differences across breath‐holds (P= .88), so the three breath‐hold attempts were averaged for subsequent analyses. The within‐ and between‐day coefficients of variation for CVR were 10.8% and 15.3%, respectively.

Conclusions

CVR assessed via a three breath‐hold protocol can be reliably measured in adolescents, yielding similar within‐ and between‐day reliability. Analyses revealed that breath‐hold length and CVR were unrelated, indicating the commonly reported normalization of CVR to breath‐hold duration (breath‐hold index) may be unnecessary in youth.
Stress and coping strategies in pediatric dental residents
Authors: Silverstein Sarah T. , Tanbonliong Thomas , Kritz‐Silverstein Donna
Published: July 2020

Purpose/objectives

This study examines the amount and sources of stress, as well as coping strategies, exercise, and alcohol use, among pediatric dental residents in the United States.

Methods

One hundred fifty pediatric dental residents (n = 76 postgraduate year [PGY] 1; n = 74 PGY2) in 2‐year residency programs responded to an anonymous survey that included demographic questions, the Perceived Stress Scale (PSS), Graduate Dental Environment Stress Scale (GDES), Tactics For Coping With Stress Inventory, and questions about alcohol consumption and exercise.

Results

Stress scores were moderate (mean PSS = 16.7 ± 7.1; GDES = 61.7 ± 16.0). The largest sources of stress were research requirements, program/clinic issues, and finances. There were no significant differences in amount and sources of stress between PGY1 and PGY2 residents (P ≥ 0.10). Residents from western programs (based on AAPD districts) reported less stress than those in other areas (PSS, P = 0.04; GDES, P = 0.09). Number of negative coping tactics used was positively correlated (PPS, P < 0.0001; GDES, P = 0.0004), while number of positive coping tactics was negatively correlated (PSS, P < 0.0001; GDES, P = 0.0008) with stress scores. Younger residents (< 30yrs) used more coping tactics than older residents (P = 0.0002). Hospital‐based residents used more negative coping tactics than those in university‐based and combined programs (P = 0.05). Residents exercising > 150 min/wk had lower PSS (P = 0.03) and GDES (P = 0.09) scores. Alcohol consumption was unrelated to stress scores.

Conclusion(s)

Amount and sources of stress do not differ by residency year. Residents utilizing positive coping strategies and exercising had lower stress than those using negative coping strategies. Pediatric dental residency programs should educate and encourage residents to use positive coping strategies and exercise.
Global Research Alliance N2O chamber methodology guidelines: Design considerations
Authors: Clough Timothy J. , Rochette Philippe , Thomas Steve M. , Pihlatie Mari , Christiansen Jesper R. , Thorman Rachel E.
Published: July 2020

Terrestrial ecosystems, both natural ecosystems and agroecosystems, generate greenhouse gases (GHGs). The chamber method is the most common method to quantify GHG fluxes from soil–plant systems and to better understand factors affecting their generation and mitigation. The objective of this study was to review and synthesize literature on chamber designs (non‐flow‐through, non‐steady‐state chamber) and associated factors that affect GHG nitrous oxide (N2O) flux measurement when using chamber methods. Chamber design requires consideration of many facets that include materials, insulation, sealing, venting, depth of placement, and the need to maintain plant growth and activity. Final designs should be tailored, and bench tested, in order to meet the nuances of the experimental objectives and the ecosystem under study while reducing potential artifacts. Good insulation, to prevent temperature fluctuations and pressure changes, and a high‐quality seal between base and chamber are essential. Elimination of pressure differentials between headspace and atmosphere through venting should be performed, and designs now exist to eliminate Venturi effects of earlier tube‐type vent designs. The use of fans within the chamber headspace increases measurement precision but may alter the flux. To establish best practice recommendations when using fans, further data are required, particularly in systems containing tall plants, to systematically evaluate the effects that fan speed, position, and mixing rate have on soil gas flux.
Multiple list coloring of 3‐choice critical graphs
Authors: Xu Rongxing , Zhu Xuding
Published: July 2020

A graph is called 3‐choice critical if is not 2‐choosable but any proper subgraph is 2‐choosable. A characterization of 3‐choice critical graphs was given by Voigt in 1998. Voigt conjectured that if is a bipartite 3‐choice critical graph, then is ‐choosable for every integer . This conjecture was disproved by Meng et al. in 2017. They showed that if where have the same parity and , or with , then is bipartite 3‐choice critical, but not (4,2)‐choosable. On the other hand, all the other bipartite 3‐choice critical graphs are (4,2)‐choosable. This paper strengthens the result of Meng, Puleo and Zhu and show that all the other bipartite 3‐choice critical graphs are ‐choosable for every integer .
Astragalus root extract improved average daily gain, immunity, antioxidant status and ruminal microbiota of early weaned yak calves
Authors: Wei Haiyan , Ding Luming , Wang Xianju , Yan Qi , Jiang Cuixia , Hu Changsheng , Wang Guowen , Zhou Yuqing , Henkin Zalmen , Degen Abraham Allan
Published: July 2020

BACKGROUND

Early weaning in yak calves is being attempted to improve yak reproduction rate. However, this has to be done with caution because of the high mortality rate of calves due to the lack of nutrients and the harsh environmental conditions. Twenty‐four weaned male yak calves were used in a 60 day feeding trial in which astragalus root extract (ARE) was supplemented. They were assigned randomly to one of four dietary treatments (n = six per treatment) that differed in ARE level: 0 g kg−1 (control), ARE0; 20 g kg−1, ARE20; 50 g kg−1, ARE50; and 80 g kg−1 dry matter intake (DMI), ARE80.

RESULTS

Final bodyweight and average daily gain (ADG) were significantly higher and the DMI/ADG ratio was significantly lower in calves with ARE supplementation than control (ARE0) calves. Ruminal concentrations of acetate and propionate and serum concentration of superoxide dismutase in ARE80 calves were higher than in the other groups and serum concentration of insulin was higher in ARE80 calves than in ARE20 calves. Serum immunoglobulin G (IgG) and interleukin‐2 (IL‐2) concentrations in ARE‐fed calves were higher than in controls. Serum tumor necrosis factor (TNF‐α) concentration was higher in ARE50 and ARE80 groups than ARE0 calves and serum interleukin‐6 (IL‐6) concentration was higher in ARE80 than in ARE0 calves. Serum immunoglobulin A (IgA), IgG and immunoglobulin M (IgM) concentrations increased with age in ARE‐fed calves. ARE supplementation increased the abundance of fiber degrading bacteria.

CONCLUSION

ARE at a dosage of 5% to 8% DMI can be supplemented to early weaned yak calves to improve growth performance, antioxidant capacity and immunity. © 2020 Society of Chemical Industry
Antioxidant, functional properties and health‐promoting potential of native South American berries: a review
Authors: Vega‐Galvez Antonio , Rodríguez Angela , Stucken Karina
Published: July 2020

Nowadays berries are globally recognized to be among the healthiest foods because they contain diverse and abundant bioactive compounds. Among these are phenolic acids, flavonoids, and anthocyanins, which are known to have beneficial health effects. South America, particularly southern Chile, is covered by a diversity of insufficiently studied and underexploited native berry species. In this review we summarize all the available literature on the phenolic composition, antioxidant activity, bioaccessibility, and biological activity of five native South American berries: calafate, maqui, murta, arrayán, and chequén. The potential of these native berries for promoting human health and as source of bioactive substances is remarkable. Bioactive compounds, mainly anthocyanins, and in less abundance flavonoids and phenolic acids, show strong antioxidant effects. Some of these constituents are bioaccessible and bioavailable, and exert anticancer, antimicrobial, and anti‐inflammatory activities as well as inhibitory effects against enzymes involved in metabolic syndromes. Given the potential of native South American berries to promote health, more work is still needed to understand fully the potential beneficial effects of the consumption of these berries on human health. © 2020 Society of Chemical Industry
Quantitative identification and segmentation repeatability of thoracic spinal muscle morphology
Authors: Pai S Anoosha , Zhang Honglin , Shewchuk Jason R. , Al Omran Bedoor , Street John , Wilson David , Doroudi Majid , Brown Stephen H. M. , Oxland Thomas R.
Published: July 2020

Objective

MRI derived spinal‐muscle morphology measurements have potential diagnostic, prognostic, and therapeutic applications in spinal health. Muscle morphology in the thoracic spine is an important determinant of kyphosis severity in older adults. However, the literature on quantification of spinal muscles to date has been limited to cervical and lumbar regions. Hence, we aim to propose a method to quantitatively identify regions of interest of thoracic spinal muscle in axial MR images and investigate the repeatability of their measurements.

Methods

Middle (T4‐T5) and lower (T8‐T9) thoracic levels of six healthy volunteers (age 26 ± 6 years) were imaged in an upright open scanner (0.5T MROpen, Paramed, Genoa, Italy). A descriptive methodology for defining the regions of interest of trapezius, erector spinae, and transversospinalis in axial MR images was developed. The guidelines for segmentation are laid out based on the points of origin and insertion, probable size, shape, and the position of the muscle groups relative to other recognizable anatomical landmarks as seen from typical axial MR images. 2D parameters such as muscle cross‐sectional area (CSA) and muscle position (radius and angle) with respect to the vertebral body centroid were computed and 3D muscle geometries were generated. Intra and inter‐rater segmentation repeatability was assessed with intraclass correlation coefficient (ICC (3,1)) for 2D parameters and with dice coefficient (DC) for 3D parameters.

Results

Intra and inter‐rater repeatability for 2D and 3D parameters for all muscles was generally good/excellent (average ICC (3,1) = 0.9 with ranges of 0.56‐0.98; average DC = 0.92 with ranges from 0.85‐0.95).

Conclusion

The guidelines proposed are important for reliable MRI‐based measurements and allow meaningful comparisons of muscle morphometry in the thoracic spine across different studies globally. Good segmentation repeatability suggests we can further investigate the effect of posture and spinal curvature on muscle morphology in the thoracic spine.
Increased Pain Reporting by Head and Neck Cancer Patients at Radiation Oncology Consultation: A Quality‐of‐Life Analysis
Authors: Havard Molly , Esslinger Hope , Mierzwa Michelle , Kharofa Jordan , Takiar Vinita
Published: July 2020

Objectives

Head and neck cancers (HNC) are associated with significant morbidity. Quality‐of‐life (QoL) analyses can assist with understanding subjective factors shaping the patient experience. Here, we assess for patient and/or tumor factors associated with increased pain reporting at the time of initial radiation oncology consultation at a single institution in 2015.

Study Design

Prospective cross‐sectional questionnaire research.

Methods

All new patient consultations in 2015 were offered the European Organization for Research and Treatment of Cancer Quality‐of‐Life Questionnaire Core‐30 (EORTC QLQ‐C30) survey. HNC patients were also offered the EORTC QLQ‐HN35 module. Retrospective chart review was performed on patients who completed the surveys. Patient demographics, tumor characteristics, and QoL responses were analyzed for potential associations. Statistical analyses were conducted using SAS v9.4 (SAS Institute, Cary, NC), with P < .05 considered significant.

Results

Of 771 new patient consultations, 137 consultations were for HNC patients. Of those, 62 patients completed both surveys. HNC patients reported greater pain relative to all other disease sites (odds ratio [OR]: 2.05; P < .01). On univariate analysis of the EORTC QLQ‐C30 data, increased pain was found to be associated with tumor size > 4 cm (OR: 3.05; P ≤ .05). The EORTC QLQ‐HN35 data revealed lymph node involvement to be independently associated with pain (OR: 3.12; P ≤ .05). On multivariate analysis, increased pain was associated with lack of pain medication prescription at the time of consultation (P ≤ .05) and age ≥ 65 years (P ≤ .05).

Conclusion

Patients with HNC reported significantly more pain at consultation than patients with other primary malignancies. Understanding factors contributing to subjective pain may allow providers to potentially address these symptoms proactively to improve patients’ QoL.

Level of Evidence

2c – Outcomes research. Laryngoscope, 131:326–332, 2021
A Systematic Review and Meta‐Analysis of Taste Dysfunction in Chronic Rhinosinusitis
Authors: Xie Deborah X. , Leland Evelyn M. , Seal Stella M. , Lin Sandra Y. , Rowan Nicholas R.
Published: July 2020

Objectives

Patients with chronic rhinosinusitis (CRS) often describe alterations in sense of taste. These complaints have historically been attributed to olfactory dysfunction; however, there is evidence of direct, objective, gustatory disturbances in the setting of CRS that are not thoroughly characterized. This study sought to investigate and summarize gustatory dysfunction experienced by patients with CRS.

Methods

PubMed, EMBASE, Cochrane Library, Web of Science, and Scopus databases were reviewed following PRISMA guidelines. English language, original studies investigating objective taste in adult patients with CRS were included. A meta‐analysis with inverse variance, random‐effects model was performed.

Results

Of 2750 studies screened, 11 articles with 471 unique patients were included. Patients with CRS exhibit worse gustatory function compared to healthy controls (standardized mean difference 0.94 [95% CI, 0.44–1.45]). Hypogeusia was identified in 32/95 (33.7%) patients from three studies that used methods with a validated definition of hypogeusia. Older age, male gender, and smoking history were associated with taste dysfunction, while objective gustatory and olfactory dysfunction were not correlated. Subjective taste and quality of life measures were also not associated with objective taste. The impact of sinus surgery on objective taste is unclear.

Conclusion

Approximately 34% of patients with CRS experience hypogeusia. Neither olfactory function nor subjective taste were associated with objective gustatory function. Given the substantial prevalence of taste dysfunction patients with CRS, there is significant potential for growth in understanding of pathogenesis, impact on quality of life, and potential treatment strategies of taste impairment in the CRS patient population.

Level of Evidence

1 Laryngoscope, 131:482–489, 2021
Nano–Micro Dimensional Structures of Fiber‐Shaped Luminous Halide Perovskite Composites for Photonic and Optoelectronic Applications
Authors: Ercan Ender , Liu Cheng‐Liang , Chen Wen‐Chang
Published: July 2020

Perovskite nanomaterials have been revealed as highly luminescent structures regarding their dimensional confinement. In particular, their promising potential lies behind remarkable luminescent properties, including color tunability, high photoluminescence quantum yield, and the narrow emission band of halide perovskite (HP) nanostructures for optoelectronic and photonic applications such as lightning and displaying operations. However, HP nanomaterials possess such drawbacks, including oxygen, moisture, temperature, or UV lights, which limit their practical applications. Recently, HP‐containing polymer composite fibers have gained much attention owing to the spatial distribution and alignment of HPs with high mechanical strength and ambient stability in addition to their remarkable optical properties comparable to that of nanocrystals. In this review, the fabrication methods for preparing nano–microdimensional HP composite fiber structures are described. Various advantages of the luminescent composite nanofibers are also described, followed by their applications for photonic and optoelectronic devices including sensors, polarizers, waveguides, lasers, light‐down converters, light‐emitting diode operations, etc. Finally, future directions and remaining challenges of HP‐based nanofibers are presented.
On Demand Light‐Degradable Polymers Based on 9,10‐Dialkoxyanthracenes
Authors: Becker Fabian , Klaiber Marvin , Franzreb Matthias , Bräse Stefan , Lahann Joerg
Published: July 2020

Light induced degradation of polymers has drawn increasing interest due to the need for externally controllable modulation of materials properties. However, the portfolio of polymers, that undergo precisely controllable degradation, is limited and typically requires UV light. A novel class of backbone‐degradable polymers that undergo aerobic degradation in the presence of visible light, yet remain stable against broad‐spectrum light under anaerobic conditions is reported. In this design, the polymer backbone is comprised of 9,10‐dialkoxyanthracene units that are selectively cleaved by singlet oxygen in the presence of green light as confirmed by NMR and UV/vis spectroscopy. The resulting polymers have been processed by electrohydrodynamic (EHD) co‐jetting into bicompartmental microfibers, where one hemisphere is selectively degraded on demand.
THE IMS PARADOX: A PERSPECTIVE ON STRUCTURAL ION MOBILITY‐MASS SPECTROMETRY
Authors: McCabe Jacob W. , Hebert Michael J. , Shirzadeh Mehdi , Mallis Christopher S. , Denton Joanna K. , Walker Thomas E. , Russell David H.
Published: July 2020

Studies of large proteins, protein complexes, and membrane protein complexes pose new challenges, most notably the need for increased ion mobility (IM) and mass spectrometry (MS) resolution. This review covers evolutionary developments in IM‐MS in the authors' and key collaborators' laboratories with specific focus on developments that enhance the utility of IM‐MS for structural analysis. IM‐MS measurements are performed on gas phase ions, thus “structural IM‐MS” appears paradoxical—do gas phase ions retain their solution phase structure? There is growing evidence to support the notion that solution phase structure(s) can be retained by the gas phase ions. It should not go unnoticed that we use “structures” in this statement because an important feature of IM‐MS is the ability to deal with conformationally heterogeneous systems, thus providing a direct measure of conformational entropy. The extension of this work to large proteins and protein complexes has motivated our development of Fourier‐transform IM‐MS instruments, a strategy first described by Hill and coworkers in 1985 (Anal Chem, 1985, 57, pp. 402–406) that has proved to be a game‐changer in our quest to merge drift tube (DT) and ion mobility and the high mass resolution orbitrap MS instruments. DT‐IMS is the only method that allows first‐principles determinations of rotationally averaged collision cross sections (CSS), which is essential for studies of biomolecules where the conformational diversities of the molecule precludes the use of CCS calibration approaches. The Fourier transform‐IM‐orbitrap instrument described here also incorporates the full suite of native MS/IM‐MS capabilities that are currently employed in the most advanced native MS/IM‐MS instruments. © 2020 John Wiley & Sons Ltd. Mass Spec Rev
Triple diffusive mixed convection flow in a duct using convective boundary conditions
Authors: Umavathi Jawali C. , Ali Hafiz Muhammad , Patil Sapnali Limbaraj
Published: July 2020

The motivation of the current article is to explore a numerical investigation on steady triply diffusive convection in a vertical channel. Heat is exchanged from the external fluid with the plates. The reference temperature is taken as equal and also as different for the external fluid. Solutions in the absence of viscous dissipation and buoyancy forces are also obtained as special cases. General solutions including the effects of viscous dissipation and buoyancy forces are obtained analytically using the method of perturbation. The analytical solutions can be used only if the Brinkman number is small. Hence to know the flow properties for all values of Brinkman number, we resort to numerical solutions. The effects of thermal Grashof number, solutal Grashof number, and the chemical reaction parameter on the flow field are evaluated numerically. The obtained results are validated against previously published results for special case of the problems.
Synthetic likelihood method for reaction network inference
Authors: Linder Daniel F. , Rempała Grzegorz A.
Published: July 2020

We propose a novel Markov chain Monte‐Carlo (MCMC) method for reverse engineering the topological structure of stochastic reaction networks, a notoriously challenging problem that is relevant in many modern areas of research, like discovering gene regulatory networks or analyzing epidemic spread. The method relies on projecting the original time series trajectories, from the stochastic data generating process, onto information rich summary statistics and constructing the appropriate synthetic likelihood function to estimate reaction rates. The resulting estimates are consistent in the large volume limit and are obtained without employing complicated tuning strategies and expensive resampling as typically used by likelihood‐free MCMC and approximate Bayesian methods. To illustrate the method, we apply it in two real data examples: the molecular pathway analysis with RNA‐seq and the famous incidence data from 1665 plague outbreak at Eyam, England.
Classical motions of infinitesimal rotators on Mylar balloons
Authors: Kovalchuk Vasyl , Mladenov Ivaïlo
Published: July 2020

This paper starts with the derivation of the most general equations of motion for the infinitesimal rotators moving on arbitrary two‐dimensional surfaces of revolution. Both geodesic and geodetic (i.e., without any external potential) equations of motion on surfaces with nontrivial curvatures that are embedded into the three‐dimensional Euclidean space are discussed. The Mylar balloon as a concrete example for the application of the scheme was chosen. A new parameterization of this surface is presented, and the corresponding equations of motion for geodesics and geodetics are expressed in an analytical form through the elliptic functions and elliptic integrals. The so‐obtained results are also compared with those for the two‐dimensional sphere embedded into the three‐dimensional Euclidean space for which it can be shown that the geodesics and geodetics are plane curves realized as the great and small circles on the sphere, respectively.
Optimizing Coded Aperture Imaging techniques to allow for online tracking of fiducial markers with high‐energy scattered radiation from treatment beam
Authors: Mahl Adam , Miller Brian , Miften Moyed , Jones Bernard L.
Published: July 2020

Purpose

Real‐time visualization of target motion using fiducial markers during radiation therapy treatment will allow for more accurate dose delivery. The purpose of this study was to optimize techniques for online fiducial marker tracking by detecting the scattered treatment beam through coded aperture imaging (CAI). Coded aperture imaging is a novel imaging technique that can allow target tracking in real time during treatment, and do so without adding any additional radiation dose, by making use of the scattered treatment beam radiation.

Methods

Radiotherapy beams of various energies, incident on phantoms containing gold fiducial markers were modeled using MCNP6.2 Monte Carlo transport code. Orthogonal scatter radiographs were collected through a CAI geometry. After decoding the simulated radiograph data, the centroid location and FWHM/SNR of the fiducial signals were analyzed. The effects of properties related to the CA (rank, pattern, and physical dimensions), detector (dimensions and pixel count), position (CA and phantom), and the incident beam (spectrum and direction) were investigated. These variables were evaluated by quantifying the positional accuracy, resolution, and SNR of the fiducials' signal. The effects of phantom scatter and decoding artifacts were reduced via Fourier filtering to avoid treatment interruption and physical interaction with the coded mask.

Results

The method was able to accurately localize the markers to within 1 pixel of a simulated radiograph. A 10 × 10 × 2 cm tungsten mask was chosen to attenuate >99 % of incident scatter through opaque elements, while minimizing collimation artifacts which arise from vignetting of the coded radiograph. Clear separation of centroids from fiducial signals with 2.5 mm separation was maintained, and initial optimization of parameters has produced an aperture which decodes the location of multiple fiducial markers inside a human phantom properly with a high SNR in the final radiograph image.

Conclusion

Current results show a proof of concept for a novel real‐time imaging method. Coded aperture imaging is a promising technique for extracting the fiducial scatter signal from a broader Compton‐scatter background. These results can be used to further optimize the CAI parameter space and guide fabrication and testing of a clinical device.
Je später, desto lieber: C(sp3)‐H‐Hydroxylierung
Authors: Thomas Franziska
Published: July 2020

Naturstoffe und Pharmakophore so spät wie möglich zu funktionalisieren, hat den Reiz, gegen Ende der Synthese die ohnehin komplexen Strukturen im Syntheseweg einfach verändern zu können. So entstehen schnell und mit wenig Aufwand unterschiedlich wirkende Moleküle. Als gutes Werkzeug dafür haben sich Eisen‐ und Mangankatalysatoren mit sterisch anspruchsvollen Substituenten herausgestellt.
Die Entstehung des Lebedew‐Verfahrens
Authors: Requardt Axel
Published: July 2020

Im Jahr 1931 ging im russischen Jaroslawl die erste großtechnische Butadien‐Anlage weltweit in Betrieb. Sie arbeitete nach einem Verfahren, das Sergej Wasilewitsch Lebedew vier Jahre zuvor im Rahmen eines Wettbewerbs entwickelt hatte. Das war der Schlüssel zur Kautschukproduktion.
Digitalisierung: molekulares Design plattformisieren
Authors: Scarbath‐Evers Laura Katharina , Cappel Daniel , Weiser Jörg
Published: July 2020

Mit Hochdurchsatzsimulationen lassen sich Milliarden hypothetischer Moleküle in kurzer Zeit auf gewünschte Eigenschaften screenen. Um simulierte und experimentelle Daten zu verbinden, bieten sich Plattformen an, mit denen Forschungsabteilungen in Echtzeit zusammenarbeiten können.
Videoclip oder Realexperiment?
Authors: Tausch Michael W.
Published: July 2020

Die Covid‐19‐Pandemie hat dazu geführt, dass Schulen verstärkt digitale Medien nutzen. Im Chemieunterricht ist der Einsatz von Videoclips aber eine zweischneidige Sache.
Evaluation of a Deepwater Release Method for Hatchery-Reared Lake Sturgeon
Authors: Lacho Christine D. , McDougall Craig A. , Nelson Patrick A. , Legge Michael M. , Gillespie Mark A. , Michaluk Yhana , Klassen Cheryl N. , Macdonald Don
Published: July 2020

Hatchery rearing and stocking of young Lake Sturgeon Acipenser fulvescens have become key management and species recovery tools in many jurisdictions, yet there has been relatively little investigation into the optimization of release methods. Based on the contemporary understanding of the species’ ecology in Boreal Shield rivers, it was hypothesized that poststocking survival and/or within-reach retention could be improved via release of hatchery-reared fish directly into the deepwater habitats that are preferred by juvenile and subadult life stages. Acoustic telemetry and mark–recapture methods were used to evaluate this hypothesis. In total, 390 PIT-tagged age-1 Lake Sturgeon (mean ± SD of length measured 1 week prior to stocking = 242 ± 29 mm FL) were released during spring 2015 from shore at the base of a set of falls on the Nelson River, Manitoba (mimicking the status quo stocking procedure for the reach), and 391 PIT-tagged individuals (240 ± 27 mm FL) were released approximately 4.2 river kilometers downstream of the shore release location into an approximately 750-m-long patch of deepwater habitat (maximum depth = 15 m) using the deepwater release method. Of the released fish, 30 (15 per stocking method) were implanted with acoustic transmitters. In total, 23% and 22% of the stocked fish were recaptured in gill-net surveys conducted during fall 2015 and 2016, respectively. Recapture proportions associated with the two release types were not significantly different. Acoustic telemetry revealed considerable variation among individuals and offered general insight into poststocking behavior but provided no direct support for the primary hypothesis. Despite the null results of the current study, optimization of release methods for Lake Sturgeon may warrant further investigation.
Variable Length at Age for Black Crappies and White Crappies in Missouri Small Impoundments
Authors: Michaletz Paul H.
Published: July 2020

I observed exceptionally variable TL at age for both Black Crappies Pomoxis nigromaculatus and White Crappies P. annularis in several small impoundments in northern Missouri. I used linear mixed models to assess the relative influences of sex, juvenile growth (back-calculated lengths at age 1 [L1] and age 2 [L2]), and age in explaining variation in TL of age-3 and older crappies. I also examined the potential effects of TL, age, and sex on body condition (relative weight Wr) and TL, age, and Wr on reproductive investment (gonadosomatic index [GSI]) of females. Models with various combinations of explanatory variables were compared with Akaike’s information criterion. The most supported model explained over 60% of the variation in TL at age of age-3 and older fish and included age, L2, and sex for both species. For White Crappies, the L2-only model explained more variation in TL than the age-only model, but the opposite was true for Black Crappies. Logistic regression using TL and L2 as independent variables revealed that crappies of both species had less than a 50% probability of reaching 229 mm TL—a common minimum TL limit—by age 5 if L2 did not exceed 150 mm, indicating the importance of juvenile growth in determining adult size. The best model for Wr included TL, age, and sex for both species but explained less than 19% of the variation in this variable. Likewise, the best models for GSI explained less than 10% of the variation and included TL and Wr for Black Crappies and TL, Wr, and age for White Crappies. Because of the importance of juvenile growth in determining sizes of adult crappies, future studies should focus on processes that influence growth rates during the juvenile phase.
Use of a Restrictive Regulation to Manage Walleyes in a New Glacial Lake in South Dakota
Authors: Blackwell Brian G. , Smith Bradley J. , Kaufman Todd M. , Moos Tyrel S.
Published: July 2020

Above-average precipitation in the 1990s resulted in many new fisheries across northeastern South Dakota and elsewhere in the Upper Midwest. Walleye Sander vitreus populations in these new fisheries can be extremely vulnerable to angler harvest. In an attempt to maintain a Walleye fishery in Reetz Lake, South Dakota, a new lake, a restrictive regulation of one Walleye ≥711 mm TL per day was implemented when the lake opened to public fishing (October 2001). To evaluate the regulation, we monitored the estimated number of Walleyes ≥508 mm, Walleye gill-net catch per unit of effort (CPUE) of stock-length fish (≥250 mm), size structure, condition, length at age at capture (ages 2–5), mortality, recruitment, and angler use during the period 2001–2019. The estimated number of Wall-eyes ≥508 mm, gill-net CPUE, and proportional size distribution of preferred-length fish (PSD-P; ≥510 mm) trended higher across years. Relative weight (Wr) for the quality–preferred (380–509 mm) and preferred–memorable (510–629 mm) length-groups and the length at age at capture for ages 4 and 5 trended lower. Walleyes <510 mm were in better condition than larger fish throughout the study. Estimated total mortality was 62% in 2004 but substantially declined in subsequent years before ranging from 6% to 21% for 2010–2019. The coefficient of variation of age-3 gill-net CPUE by cohort was 93%, indicating variable recruitment. Decreasing trends in Wr and growth were not surprising, as Walleye CPUE increased through time. Lengths at age remained at or above statewide and national averages. The values for number of angler-hours and Walleye catch rates were high during the summer months when most anglers targeted Walleye. The regulation that restricted harvest at Reetz Lake to one Walleye ≥711 mm allowed an abundant Walleye population to establish and was successful at maintaining the fishery in terms of abundance, size structure, and angler use.
Acid‐Catalyzed Rearrangements of 3‐Aryloxirane‐2‐Carboxamides: Novel DFT Mechanistic Insights
Authors: Qu Zheng‐Wang , Zhu Hui , Katsyuba Sergey A. , Mamedova Vera L. , Mamedov Vakhid A. , Grimme Stefan
Published: July 2020

Efficient synthesis of 3‐arylquinolin‐2(1H)‐ones and N‐(2‐carboxyaryl)‐oxalamides from protic acid‐catalyzed rearrangements of 3‐aryloxirane‐2‐carboxamides was achieved recently but not well understood. In contrast to the classical Meinwald rearrangement, extensive DFT calculations reveal that the proximal aryl and amide groups have strong synergetic effects to control the amide‐aided and aryl‐directed oxirane‐opening and further rearrangement sequences. The ortho‐nitro substituent of the proximal aryl is directly involved in a nucleophilic oxirane ring‐opening, the amide C=O is an important proton shuttle for facile H‐shifts, while the N‐aryl may act as a potential ring‐closing site via Friedel‐Crafts alkylation. The mechanistic insights are useful for rational design of novel synthesis by changing the aryl and amide functional groups proximal to the oxirane ring.
Take Advantage of Lessons Learned During the Pandemic
Authors: Burke Darcy , Macler Bruce
Published: July 2020

The COVID‐19 pandemic has had wide‐ranging effects on the water industry, but now you and your colleagues are getting your utility back to “normal,” whatever normal now means. As of this writing in mid‐May, events are still moving unexpectedly and unevenly, so some things still can't be predicted. However, the fundamentals still apply. You need to ensure employee health and safety, your customers require attention, and operations need to continue.
Reduced‐dose craniospinal irradiation for central nervous system relapsed neuroblastoma
Authors: Luo Leo Y. , Kramer Kim , Cheung Nai‐Kong V. , Kushner Brian H. , Modak Shakeel , Basu Ellen M. , Roberts Stephen S. , Wolden Suzanne L.
Published: July 2020

Purpose

In patients with high‐risk neuroblastoma, there is an increased recognition of relapse in the central nervous system (CNS). Craniospinal irradiation (CSI) has been an effective treatment but carries significant long‐term complications. It is unclear whether reducing the CSI dose from 21 to 18 Gy can achieve similar CNS tumor control.

Patients and methods

A retrospective review of pediatric patients with CNS‐relapsed neuroblastoma treated with CSI and boost to parenchymal lesions between 2003 and 2019 was performed. The goal was to assess CNS control comparing 18 Gy and 21 Gy regimens.

Results

Ninety‐four patients with CNS‐relapsed neuroblastoma were treated with CSI followed by intraventricular compartmental radioimmunotherapy. Median age at the time of CNS disease was 4 years (range 1‐13 years). Forty‐one patients (44%) received 21 Gy CSI prior to an institutional decision to lower the dose; 53 patients (56%) received 18 Gy CSI. Seventy‐nine patients (84%) received additional boosts. With a median follow up of 4.1 years for surviving patients, 2‐year CNS relapse‐free survival was 74% for 18 Gy group versus 77% for 21 Gy group, and 5‐year CNS relapse‐free survival was 66% for 18 Gy versus 72% for 21 Gy group, respectively (P = .40). Five‐year overall survival rate was 43% in 18 Gy group versus 47% in 21 Gy group (P = .72).

Conclusion

For patients with CNS‐relapsed neuroblastoma, CNS disease control is comparable between 18 Gy and 21 Gy CSI dose regimens, in conjunction with radioimmunotherapy and CNS penetrating chemotherapy. More than 65% of the patients remain CNS disease free after 5 years. The findings support 18 Gy as the new standard CSI dose for CNS‐relapsed neuroblastoma.
Biodegradable polymeric networks of poly(propylene fumarate) and phosphonic acid‐based monomers
Authors: Cemali Görkem , Aruh Avram , Köse Gamze Torun , Can Erde
Published: July 2020

Poly(propylene fumarate) (PPF) was crosslinked with vinyl phosphonic acid (VPA) and vinyl phosphonic acid diethyl ester (VPES) to prepare biodegradable and biocompatible polymers with a network structure. Intended for this purpose, the PPF pre‐polymer was synthesized through a polycondensation reaction of propylene glycol and fumaric acid in an excess of propylene glycol. The PPF pre‐polymer was then thermally cured with various ratios of VPA and VPES in the presence of benzoyl peroxide initiator via radical polymerization. Complete cure of PPF/VPA and PPF/VPES copolymers was confirmed by differential scanning calorimetry, crosslink density was determined via swelling experiments, and thermomechanical properties and thermal degradation profiles were characterized by dynamic mechanical and thermogravimetric analyses, respectively. Various compositions of the PPF/VPA and PPF/VPES copolymers exhibited compressive modulus values in the wide range 10–836 MPa and compressive strength values in the range 14–119 MPa. The equilibrium water content of the PPF/VPA and PPF/VPES copolymers ranged from 4 to 20.5 wt%. Biodegradation rate of the polymers in buffer solution at 37 °C, examined via both weight loss and pH measurements, was significantly influenced by the co‐monomer and initiator compositions. Combining the results of these studies indicated that PPF/VPA and PPF/VPES copolymers show potential for applications as bone tissue engineering scaffolds. Moreover, just varying PPF and co‐monomer ratio and initiator amount provides adjustable and controllable characteristics of the end product. © 2020 Society of Industrial Chemistry
Computational mechanistic study of human liver glycerol 3‐phosphate dehydrogenase using ONIOM method
Authors: Yildiz Ibrahim , Sizirici Yildiz Banu
Published: July 2020

Human liver glycerol 3‐phosphate dehydrogenase catalyzes transfer of a hydride anion from NADH to dihydroxyacetone phosphate (DHAP) forming L‐glycerol 3‐phosphate and NAD+ in a single step reaction. It is proposed that a hydride ion is transferred from NADH to the carbonyl carbon of DHAP through a general acid catalysis in which the carbonyl oxygen of DHAP is protonated by a nearby acidic residue. Based on the crystal structure of enzyme, it was suggested that one of the active site lysine residues (Lys120/Lys204) might act as general acid for the protonation of the carbonyl oxygen at DHAP. In this study, we formulated a number of computational systems to study the hydride transfer mechanism including main active site amino acid side chains, NADH cofactor, and DHAP. The calculations involved ONIOM method consisting of DFT and molecular mechanics (MM). We evaluated the energetics of the hydride transfer process in different model systems while probing the roles of active site residues, Lys120/Lys204/Asp260. Based on calculations, protonated Asp260 has more favorable energetics to act as the general acid catalysis as compared to Lys120/204 residues.
Value of lung ultrasonography to predict weaning success in ventilated neonates
Authors: El Amrousy Doaa , Elgendy Marwa , Eltomey Mohamed , Elmashad Abd Elrahman
Published: July 2020

Background

Invasive mechanical ventilation (MV) is lifesaving for critically ill neonates. Limiting the duration of MV support is crucial. Lung ultrasonography is a bedside technique useful to predict weaning success in adults, but few data are available about its use in neonates. Our aim was to assess the value of lung ultrasonography to predict weaning success of the ventilated neonates.

Methods

This study included 80 neonates on MV suffering from different pulmonary diseases. All patients had lung ultrasound just before extubation and 6 hours after extubation. Lung ultrasound score (LUS) was calculated for all neonate. Blood gases and chest x‐ray were performed just before extubation as well. All neonates were followed up for 48 hours after extubation for extubation failure (EF).

Results

Eighteen neonates (22.5%) experienced EF. Neonates with EF had significantly lower gestational age, lower weight but significantly prolonged duration of MV, prolonged NICU stay, and higher mortality. LUS before and after extubation was significantly higher in neonates with EF than those with weaning success. Pre‐extubation LUS had a sensitivity of 83% and a specificity of 88% to predict weaning success in neonates at a cutoff value ≤4. While, post‐extubation LUS had a sensitivity of 89%, and a specificity of 90% to predict weaning success in neonates at a cutoff point ≤6.

Conclusion

Lung ultrasound is a rapid, noninvasive, repetitive, and reliable tool for predicting the weaning success of ventilated neonates.
Introducing variability in targeting the microtubules: Review of current mechanisms and future directions in colchicine therapy
Authors: Forkosh Esther , Kenig Ariel , Ilan Yaron
Published: July 2020

Microtubules (MTs) are highly dynamic polymers that constitute the cellular cytoskeleton and play a role in multiple cellular functions. Variability characterizes biological systems and is considered a part of the normal function of cells and organs. Variability contributes to cell plasticity and is a mechanism for overcoming errors in cellular level assembly and function, and potentially the whole organ level. Dynamic instability is a feature of biological variability that characterizes the function of MTs. The dynamic behavior of MTs constitutes the basis for multiple biological processes that contribute to cellular plasticity and the timing of cell signaling. Colchicine is a MT‐modifying drug that exerts anti‐inflammatory and anti‐cancer effects. This review discusses some of the functions of colchicine and presents a platform for introducing variability while targeting MTs in intestinal cells, the microbiome, the gut, and the systemic immune system. This platform can be used for implementing novel therapies, improving response to chronic MT‐based therapies, overcoming drug resistance, exerting gut‐based systemic immune responses, and generating patient‐tailored dynamic therapeutic regimens.