bluuebunny/crossref_metadata_2025 huggingface dataset:
Diplopia in Progressive Supranuclear Palsy
Authors: Yazdi Narges , Ghamsari Mona Ramezani , Shoeibi Ali , Rohani Mohammad
Published: December 2019

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Noonan syndrome‐associated biallelic LZTR1 mutations cause cardiac hypertrophy and vascular malformations in zebrafish
Authors: Nakagama Yu , Takeda Norihiko , Ogawa Seishi , Takeda Hiroyuki , Furutani Yoshiyuki , Nakanishi Toshio , Sato Tatsuyuki , Hirata Yoichiro , Oka Akira , Inuzuka Ryo
Published: December 2019

Background

Variants in the LZTR1 (leucine‐zipper‐like transcription regulator 1) gene (OMIM #600574) have been reported in recessive Noonan syndrome patients. In vivo evidence from animal models to support its causative role is lacking.

Methods

By CRISPR‐Cas9 genome editing, we generated lztr1‐mutated zebrafish (Danio rerio). Analyses of histopathology and downstream signaling were performed to investigate the pathogenesis of cardiac and extracardiac abnormalities in Noonan syndrome.

Results

A frameshift deletion allele was created in the zebrafish lztr1. Crosses of heterozygotes obtained homozygous lztr1 null mutants that modeled LZTR1 loss‐of‐function. Histological analyses of the model revealed ventricular hypertrophy, the deleterious signature of Noonan syndrome‐associated cardiomyopathy. Further, assessment for extracardiac abnormalities documented multiple vascular malformations, resembling human vascular pathology caused by RAS/MAPK activation. Due to spatiotemporal regulation of LZTR1, its downstream function was not fully elucidated from western blots of adult tissue.

Conclusion

Our novel zebrafish model phenocopied human recessive Noonan syndrome and supported the loss‐of‐function mechanism of disease‐causing LZTR1 variants. The discovery of vascular malformations in mutants calls for the clinical follow‐up of patients to monitor for its emergence. The model will serve as a novel platform for investigating the pathophysiology linking RAS/MAPK signaling to cardiac and vascular pathology.
Novel high‐order breathers and rogue waves in the Boussinesq equation via determinants
Authors: Liu Yunkai , Li Biao , Wazwaz Abdul‐Majid
Published: December 2019

By virtue of the bilinear method and the Kadomtsev–Petviashvili (KP) hierarchy reduction technique, wider classes of high‐order breather and semirational and rogue wave solutions to the Boussinesq equation are derived. These solutions are presented explicitly in terms of Gram determinants, whose matrix elements have simply algebraic expressions. The breather and rogue wave solutions are derived from two different types of tau functions of a bilinear equation in the single‐component KP hierarchy. By taking a long wave limit of high‐order breather solutions, a range of hybrid solutions consisting of solitons, breathers, and one fundamental rogue wave are generated. For the rational rogue waves, some typical patterns such as Peregrine‐type, triple, and sextuple rogue waves are put forward by modifying the input parameters. Besides, a new rogue wave pattern of third‐order rogue waves is found, which features a mixture of a triangular pattern of three fundamental rogue waves and a fundamental pattern of second‐order rogue wave. These results may help understand the protean rogue wave manifestations in areas ranging from water waves to fluid dynamics.
An iterative approach to solve a nonlinear moving boundary problem describing the solvent diffusion within glassy polymers
Authors: Garshasbi Morteza , Malek Bagomghaleh Shadi
Published: December 2019

This paper consists in studying a mathematical model of solvent diffusion through the glassy polymers as a one‐dimensional moving boundary problem with kinetic undercooling. We establish an iterative variable time‐step method based on a nonstandard finite difference (NSFD) scheme to solve the considered moving boundary problem. The monotonicity and positivity of the numerical solution are proved. The numerical approach is investigated for three test problems composed of constant and inconstant diffusion coefficients for different values of parameters to demonstrate the validity and ability of the method.
AAPM recommendations on medical physics practices for ocular plaque brachytherapy: Report of task group 221
Authors: Thomson Rowan M. , Furutani Keith M. , Kaulich Theodor W. , Mourtada Firas , Rivard Mark J. , Soares Christopher G. , Vanneste Françoise M. , Melhus Christopher S.
Published: December 2019

The American Association of Physicists in Medicine (AAPM) formed Task Group 221 (TG‐221) to discuss a generalized commissioning process, quality management considerations, and clinical physics practice standards for ocular plaque brachytherapy. The purpose of this report is also, in part, to aid the clinician to implement recommendations of the AAPM TG‐129 report, which placed emphasis on dosimetric considerations for ocular brachytherapy applicators used in the Collaborative Ocular Melanoma Study (COMS). This report is intended to assist medical physicists in establishing a new ocular brachytherapy program and, for existing programs, in reviewing and updating clinical practices. The report scope includes photon‐ and beta‐emitting sources and source:applicator combinations. Dosimetric studies for photon and beta sources are reviewed to summarize the salient issues and provide references for additional study. The components of an ocular plaque brachytherapy quality management program are discussed, including radiation safety considerations, source calibration methodology, applicator commissioning, imaging quality assurance tests for treatment planning, treatment planning strategies, and treatment planning system commissioning. Finally, specific guidelines for commissioning an ocular plaque brachytherapy program, clinical physics practice standards in ocular plaque brachytherapy, and other areas reflecting the need for specialized treatment planning systems, measurement phantoms, and detectors (among other topics) to support the clinical practice of ocular brachytherapy are presented. Expected future advances and developments for ocular brachytherapy are discussed.
Spline curve deformation model with prior shapes for identifying adhesion boundaries between large lung tumors and tissues around lungs in CT images
Authors: Zhang Xin , Wang Jie , Yang Ying , Wang Bing , Gu Lixu
Published: December 2019

Purpose

Automated segmentation of lung tumors attached to anatomic structures such as the chest wall or mediastinum remains a technical challenge because of the similar Hounsfield units of these structures. To address this challenge, we propose herein a spline curve deformation model that combines prior shapes to correct large spatially contiguous errors (LSCEs) in input shapes derived from image‐appearance cues.The model is then used to identify the adhesion boundaries between large lung tumors and tissue around the lungs.

Methods

The deformation of the whole curve is driven by the transformation of the control points (CPs) of the spline curve, which are influenced by external and internal forces. The external force drives the model to fit the positions of the non‐LSCEs of the input shapes while the internal force ensures the local similarity of the displacements of the neighboring CPs. The proposed model corrects the gross errors in the lung input shape caused by large lung tumors, where the initial lung shape for the model is inferred from the training shapes by shape group‐based sparse prior information and the input lung shape is inferred by adaptive‐thresholding‐based segmentation followed by morphological refinement.

Results

The accuracy of the proposed model is verified by applying it to images of lungs with either moderate large‐sized (ML) tumors or giant large‐sized (GL) tumors. The quantitative results in terms of the averages of the dice similarity coefficient (DSC) and the Jaccard similarity index (SI) are 0.982 ± 0.006 and 0.965 ± 0.012 for segmentation of lungs adhered by ML tumors, and 0.952 ± 0.048 and 0.926 ± 0.059 for segmentation of lungs adhered by GL tumors, which give 0.943 ± 0.021 and 0.897 ± 0.041 for segmentation of the ML tumors, and 0.907 ± 0.057 and 0.888 ± 0.091 for segmentation of the GL tumors, respectively. In addition, the bidirectional Hausdorff distances are 5.7 ± 1.4 and 11.3 ± 2.5 mm for segmentation of lungs with ML and GL tumors, respectively.

Conclusions

When combined with prior shapes, the proposed spline curve deformation can deal with large spatially consecutive errors in object shapes obtained from image‐appearance information. We verified this method by applying it to the segmentation of lungs with large tumors adhered to the tissue around the lungs and the large tumors. Both the qualitative and quantitative results are more accurate and repeatable than results obtained with current state‐of‐the‐art techniques.
High spatial resolution inorganic scintillator detector for high‐energy X‐ray beam at small field irradiation
Authors: Debnath Sree Bash Chandra , Fauquet Carole , Tallet Agnes , Goncalves Anthony , Lavandier Sébastien , Jandard Franck , Tonneau Didier , Darreon Julien
Published: December 2019

Purpose

Small field dosimetry for radiotherapy is one of the major challenges due to the size of most dosimeters, for example, sufficient spatial resolution, accurate dose distribution and energy dependency of the detector. In this context, the purpose of this research is to develop a small size scintillating detector targeting small field dosimetry and compare its performance with other commercial detectors.

Method

An inorganic scintillator detector (ISD) of about 200 µm outer diameter was developed and tested through different small field dosimetric characterizations under high‐energy photons (6 and 15 MV) delivered by an Elekta Linear Accelerator (LINAC). Percentage depth dose (PDD) and beam profile measurements were compared using dosimeters from PTW namely, microdiamond and PinPoint three‐dimensional (PP3D) detector. A background fiber method has been considered to quantitate and eliminate the minimal Cerenkov effect from the total optical signal magnitude. Measurements were performed inside a water phantom under IAEA Technical Reports Series recommendations (IAEA TRS 381 and TRS 483).

Results

Small fields ranging from 3 × 3 cm2, down to 0.5 × 0.5 cm2 were sequentially measured using the ISD and commercial dosimeters, and a good agreement was obtained among all measurements. The result also shows that, scintillating detector has good repeatability and reproducibility of the output signal with maximum deviation of 0.26% and 0.5% respectively. The Full Width Half Maximum (FWHM) was measured 0.55 cm for the smallest available square size field of 0.5 × 0.5 cm2, where the discrepancy of 0.05 cm is due to the scattering effects inside the water and convolution effect between field and detector geometries. Percentage depth dose factor dependence variation with water depth exhibits nearly the same behavior for all tested detectors. The ISD allows to perform dose measurements at a very high accuracy from low (50 cGy/min) to high dose rates (800 cGy/min) and was found to be independent of dose rate variation. The detection system also showed an excellent linearity with dose; hence, calibration was easily achieved.

Conclusions

The developed detector can be used to accurately measure the delivered dose at small fields during the treatment of small volume tumors. The author's measurement shows that despite using a nonwater‐equivalent detector, the detector can be a powerful candidate for beam characterization and quality assurance in, for example, radiosurgery, Intensity‐Modulated Radiotherapy (IMRT), and brachytherapy. Our detector can provide real‐time dose measurement and good spatial resolution with immediate readout, simplicity, flexibility, and robustness.
A deep learning method for producing ventilation images from 4DCT: First comparison with technegas SPECT ventilation
Authors: Liu Zhiqiang , Miao Junjie , Huang Peng , Wang Wenqing , Wang Xin , Zhai Yirui , Wang Jingbo , Zhou Zongmei , Bi Nan , Tian Yuan , Dai Jianrong
Published: December 2019

Purpose

The purpose of this study is to develop a deep learning (DL) method for producing four‐dimensional computed tomography (4DCT) ventilation imaging and to evaluate the accuracy of the DL‐based ventilation imaging against single‐photon emission‐computed tomography (SPECT) ventilation imaging (SPECT‐VI). The performance of the DL‐based method is assessed by comparing with density change‐ and Jacobian‐based (HU and JAC) methods.

Materials and methods

Fifty patients with esophagus or lung cancer who underwent thoracic radiotherapy were enrolled in this study. For each patient, 4DCT scans paired with 99mTc‐Technegas SPECT/CT were acquired before the first radiotherapy treatment. 4DCT and SPECT/CT were first rigidly registered using MIMvista and converted to data matrix using MATLAB, and then transferred to a DL model based on U‐net for correlating 4DCT features and SPECT‐VI. Two forms of 4DCT dataset [(a) ten phases and (b) two phases of peak‐exhalation and peak‐inhalation] as input are studied. Tenfold cross‐validation procedure was used to evaluate the performance of the DL model. For comparative evaluation, HU and JAC methodologies are used to calculate specific ventilation imaging based on 4DCT (CTVI) for each patient. The voxel‐wise Spearman’s correlation was evaluated over the whole lung between each of CTVI and corresponding SPECT‐VI. The SPECT‐VI and produced CTVIs were segmented into high, median, and low functional lung (HFL, MFL, and LFL) regions. The spatial overlap of corresponding HFL, MFL, and LFL for each CTVI against SPECT‐VI was also evaluated using the dice similarity coefficient (DSC). The averaged DSC of functional lung regions was calculated and statistically analyzed with a one‐factor ANONA model among different methods.

Results

The voxel‐wise Spearman rs values were (0.22 ± 0.31), (−0.09 ± 0.18), and (0.73 ± 0.16)/(0.71 ± 0.17) for the CTVIHU, CTVIJAC, and CTVIDL(1)/CTVIDL(2). These results showed the DL method yielded the strongest correlation with SPECT‐VI. Using the DSC as the spatial overlap metric, we found that the CTVIHU, CTVIJAC, and CTVIDL(1)/CTVIDL(2) methods achieved averaged DSC values for all patients to be (0.45 ± 0.08), (0.33 ± 0.04), and (0.73 ± 0.09)/(0.71 ± 0.09), respectively. The results demonstrated that the DL method yielded the highest similarity with SPECT‐VI with the prominently significant difference (P < 10−7).

Conclusions

This study developed a DL method for producing CTVI and performed a validation against SPECT‐VI. The results demonstrated that DL method can derive CTVI with greatly improved accuracy in comparison to HU and JAC methods. The produced ventilation images can be more accurate and useful for lung functional avoidance radiotherapy and treatment response modeling.
Elucidating heteroatom influence on homonuclear 4J(H,H) coupling constants by DFT/NMR approach
Authors: Chini Maria Giovanna , Urbani Daniele , Dambruoso Paolo , Riccio Raffaele , Bifulco Giuseppe
Published: December 2019

We report the structural dependency of long range scalar J‐coupling constant across four bonds as function of the dihedral angles Φ1 and Φ3. The calculated homonuclear coupling constants 4J(H,H), obtained at a density functional theory level, were measured between C(1)─X(2) and X(2)─C(3) bonds in three‐term models, where C, N, O, and S were systematically used as the second atom of the alkyl structures (1‐4).

The 4J(H,H) calculated values, tabulated for variation of 30° for both Φ1 and Φ3, have disclosed an unexpected detectable coupling constant (4J(H,H) ≥ 1 Hz) across heteroatoms, useful to provide valuable structural information. A 2‐methyl‐1,3‐dithiane sulfide (5) was used as a case study to prove the applicability and reliability of the calculated values to real issues. The 4J(H,H) values obtained at density functional theory for the system 4 have reproduced with good accuracy an unexpected experimental 4J(H2ax‐H4ax) = 1.01 Hz of sulfide molecule (5), suggesting these calculated coupling constant values as a new powerful tool for the organic synthesis and stereochemical analysis.
Solvent optimization and conformational flexibility effects on 1H and 13C NMR scaling factors
Authors: Merrill Amy T. , Tantillo Dean J.
Published: December 2019

The effects of including (a) implicit solvent in geometry optimizations, (b) conformationally flexible molecules in test sets, and (c) empirical dispersion D3(BJ) on scaling factors for predicting 1H and 13C NMR chemical shifts were explored. Scaling factors with optimizations performed in the gas phase and with a Polarizable Continuum Model (PCM) solvent model were obtained for 12 organic solvents, including 2,2,2‐trifluroethanol and chlorobenzene, for which scaling factors have been developed for the first time. Scaling factors for aromatic solvents were split into primary and secondary scaling factors to account for CH–π effects. Including empirical dispersion D3(BJ) did not lead to significant improvement.
Thermo‐acoustic ultrasound for noninvasive temperature monitoring at lead tips during MRI
Authors: Dixit Neerav , Pauly John M. , Scott Greig C.
Published: December 2019

Purpose

We explore the use of thermo‐acoustic ultrasound (TAUS) to monitor temperature at the tips of conductive device leads during MRI.

Theory

In TAUS, rapid radiofrequency (RF) power deposition excites an acoustic signal via thermoelastic expansion. Coupling of the MRI RF transmit to device leads causes SAR amplification at lead tips, allowing MRI RF transmitters to excite significant lead tip TAUS signals. Because the amplitude of the TAUS signal depends on temperature, it becomes feasible to monitor the lead tip temperature during MRI by tracking the TAUS amplitude.

Methods

The TAUS temperature dependence was characterized in a phantom and in tissue. To perform TAUS acquisitions in an MRI scanner, amplitude modulated RF chirps were transmitted by the body coil, and the lead tip TAUS signal was detected by an ultrasonic transducer. The TAUS signal level was correlated with the RF current induced on the lead and the associated artifacts in MRI. TAUS signals acquired during RF‐induced heating were used to estimate the lead tip temperature.

Results

The TAUS signal exhibited strong dependence on temperature, increasing over 30% with C of heating both in the phantom and in tissue. A lead tip TAUS signal was observed for a 100 mA rms current induced on a lead. During RF‐induced heating, the TAUS signal appeared to accurately approximate the peak lead tip temperature.

Conclusions

TAUS allows for noninvasive monitoring of lead tip temperature in an MRI environment. With further development, TAUS opens new avenues to improve RF device safety during MRI scans.
Spin‐lock imaging of intrinsic susceptibility gradients in tumors
Authors: Zu Zhongliang , Janve Vaibhav , Gore John C.
Published: December 2019

Purpose

Previous studies have shown that diffusion of water through intrinsic susceptibility gradients produces a dispersion of the spin‐lattice relaxation rate in the rotating frame (R1ρ) over a low range of spin‐locking amplitudes (0 < ω1 < 100 Hz), whereas at higher ω1 and high magnetic fields, a second dispersion arises due to chemical exchange. Here, we separated these different effects and evaluated their contributions in tumors.

Methods

Maps of R1ρ and its changes with locking field were acquired on intracranial 9‐L tumor models. The R1ρ changes due to diffusion () were calculated by subtracting maps of R1ρ at 100 Hz (R1ρ[100 Hz]) from those at 0 Hz (R1ρ[0 Hz]). The R1ρ changes due to exchange () were calculated by subtracting maps of R1ρ at 5620 Hz (R1ρ[5620 Hz]) from those of R1ρ at 100 Hz (R1ρ[100 Hz]). Measurements of vascular dimensions and spacing were performed ex vivo using 3D confocal microscopy.

Results

The R1ρ changes at low ω1 in tumors (5.24 ± 1.78 s−1) are substantially (p = 3.76) greater than those in normal tissues (1.36 ± 0.70 s−1), which we suggest are due to greater contributions from diffusion through susceptibility gradients. Tumor vessels were larger and spaced less closely compared with normal brain, which may be 1 factor contributing the susceptibility within 9‐L tumors. The contrast between tumor and normal tissues for is larger than for and for the apparent R2w.

Conclusion

Images that are sensitive to the variations of spin‐lock relaxation rates at low ω1 provide a novel form of contrast that reflects the heterogeneous nature of intrinsic variations within tumors.
Interleukin‐6 secretion by fibroblasts in carpal tunnel syndrome patients is associated with trigger finger and inhibited by tranilast
Authors: Kawamoto Hiroya , Iwatsuki Katsuyuki , Kurimoto Shigeru , Yamamoto Michiro , Tatebe Masahiro , Morita Akimasa , Kinoshita Fumie , Hirata Hitoshi
Published: December 2019

Introduction

In this study we aimed to clarify the association between interleukin‐6 (IL‐6) secretion in fibroblasts in carpal tunnel syndrome (CTS) patients and their biophysical parameters, including association with trigger finger and whether tranilast inhibits IL‐6 secretion in fibroblasts.

Methods

Fibroblasts were obtained from tenosynovial tissue harvested from idiopathic CTS patients undergoing carpal tunnel release and tenosynovectomy and cultured in media containing tranilast with or without tumor necrosis‐α (TNF‐α) or interleukin‐1β (IL‐1β). Their proliferation was evaluated and secreted IL‐6 levels and IL‐6 mRNA expression were quantified. Correlations between IL‐6 concentration and patient characteristics were examined.

Results

IL‐6 secretion was significantly associated with trigger finger (P = .001). Tranilast inhibited fibroblast proliferation in a dose‐dependent manner and suppressed IL‐6 secretion.

Discussion

IL‐6 overproduction in tenosynovial tissue may account for the association between CTS and trigger finger. Future studies should investigate whether tranilast can be used to treat patients with CTS.
A step toward the future of seamless measurement with wearable sensors in pediatric populations with neuromuscular diseases
Authors: Lang Catherine E. , Cade W. Todd
Published: December 2019

See article on pages 293–300 in this issue.
Preparation of novel, liquid, solvent‐free, polyolefin‐based adhesives
Authors: Hanifpour Ahad , Bahri‐Laleh Naeimeh , Nekoomanesh‐Haghighi Mehdi
Published: December 2019

An innovative procedure for functionalization of polyolefins was developed. It was found that synthesized polyolefins end‐capped with trimethoxysilane (silylated polyolefins) are new polyolefin‐based adhesives. To prepare the mentioned materials,1‐octene as a higher α‐olefin was cooligomerized with two linear, nonconjugated dienes (ie, 1,5‐hexadiene and 1,7‐octadiene) by using metallocene catalyst system, Cp2HfCl2/MAO, at room temperature. Then, amine‐terminated trimethoxysilane (3‐aminopropyltrimethoxysilane) was reacted with unsaturated bonds of synthesized cooligomers in the presence of palladium(II) acetate. Embedding of the dienes on 1‐octene oligomeric chains was explored by Fourier transform infrared (FTIR), 1H, and 13C‐NMR spectroscopy. On the basis of the results, 1,5‐hexadiene showed both 1‐butene branch and five‐member ring. On the other hand, 1,7‐octadiene was incorporated by 1,2‐addition, forming both 1‐hexene branch and seven‐member ring in the cooligomer backbone. Mole percentage of CC and cyclic moieties reached to a value of 28.54, 18.59% mol in 1‐octene/1,5‐hexadiene, and 38.04, 6.71% mol in 1‐octene/1,7‐octadiene cooligomers, respectively. Reaction of synthesized cooligomers with 3‐aminopropyltrimethoxysilane was confirmed by FTIR spectroscopy, which yielded targeted adhesives. To study the adhesion properties, resulting adhesives were applied to different substrates. Obtained results demonstrated that tensile shear strength of synthesized adhesives to polar substrates was 2.21% to 2.84% more than nonpolar substrates. Among studied systems, the best performance was achieved by1‐octene/1,7‐octadiene–based adhesive and Al substrate with tensile shear strength of 1.45 N/mm2.
Preparation of piperazine cyanurate by hydrogen‐bonding self‐assembly reaction and its application in intumescent flame‐retardant polypropylene composites
Authors: Dong Haoran , Yuan Bihe , Qi Congrui , Li Kaiyuan , Shang Sheng , Sun Yaru , Chen Gongqing , Zhang Hongming , Chen Xianfeng
Published: December 2019

Piperazine cyanurate (PCA) is designed and synthesized via hydrogen‐bonding self‐assembly reactions between piperazine and cyanuric acid. Chemical structure and morphology of PCA are investigated by Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. The prepared PCA is combined with ammonium polyphosphate (APP) to prepare flame‐retardant polypropylene (PP) composites. Thermostability, flammability, and combustion characteristics of PP composites are analyzed. The maximum thermal decomposition rate of flame‐retarded PP composites has an apparent reduction compared with that of pure PP, and obvious char is left for this intumescent flame retardant (IFR) system of APP and PCA. A high limiting oxygen index value and UL‐94 V‐0 rating are achieved with addition of APP and PCA. In cone calorimetry test, heat and smoke releases of PP are significantly decreased by this IFR system. Gaseous decomposition products during the thermal decomposition of flame‐retardant composites are studied. Chemical structure and morphology of char residues are analyzed. The results illustrate that APP and PCA have a superb synergistic action in the aspect of improvement in fire safety of PP. A possible flame‐retardant mechanism is concluded to reveal the synergism between APP and PCA.
Efficient approach to enhancing the fire resistance of polypropylene by modified microporous aluminosilicate from kaolinite as synergist
Authors: Gu Xiaoyu , Wang Yufei , Liu Xiaodong , Zhang Sheng , Li Hongfei , Sun Jun , Jin Xiaodong , Tang Wufei
Published: December 2019

In this work, kaolinite (K) was firstly converted to one kind of microporus aluminosilicate (4A) by a green andeconomical method, which was thenacted as the precursor to synthesize two other microporus aluminosilicate (3A and 5A) by ions exchange. After modified and loaded with one kind of rare earth ion (La3+), the final product (A‐La) was then used as synergist to enhance fire retardant property for polypropylene (PP) with intumescent flame‐retardants (IFR). The properties of PP composites for thermal stability and flame retardant were studied and demonstrated that A‐La, especially 4A‐La, had the most obviously flame‐retardant effect. Meanwhile, the macro/micro‐structure of char residues and real‐time fourier transform infrared spectroscopy (FTIR) after heating also showed that A‐La were helpful to promote the formation of homogenous and compact intumescent char layer. This dense carbon layer can effectively control the convection of combustion gases mixture, and heat transfer between underlying matrix and outside environment.
Effect of thermoplastic resin transfer molding process and flame surface treatment on mechanical properties of carbon fiber reinforced polyamide 6 composite
Authors: Lee Jungwoo , Lim Jun Woo , Kim Minkook
Published: December 2019

The thermoplastic resin transfer molding (T‐RTM) process for carbon fiber reinforced thermoplastic polymer composites (CFRTP) were experimentally investigated and optimized using high‐pressure resin transfer molding system for mass production. The CFRTP was manufactured by Anionic ring opening polymerization of the T‐RTM process and the curing process was analyzed by in situ cure monitoring using dielectrometry. Mechanical properties, productivity, and crystal structures of the PA 6 matrix and CFRTP were evaluated by differential scanning calorimetry, X‐ray diffraction analysis, tensile, and interlaminar shear strength tests. The crystallinity, impregnation quality and process speed were determined by the curing temperature. In addition, a time‐ and cost‐effective flame surface treatment was developed to remove moisture from the carbon fiber and increase the interfacial bonding strength of the CFRTP. As a result, optimal T‐RTM processing conditions were suggested for realizing maximum productivity and mechanical properties for the CFRTP.
Machine Learning Line Bundle Cohomology
Authors: Brodie Callum R. , Constantin Andrei , Deen Rehan , Lukas Andre
Published: December 2019

We investigate different approaches to machine learning of line bundle cohomology on complex surfaces as well as on Calabi‐Yau three‐folds. Standard function learning based on simple fully connected networks with logistic sigmoids is reviewed and its main features and shortcomings are discussed. It has been observed recently that line bundle cohomology can be described by dividing the Picard lattice into certain regions in each of which the cohomology dimension is described by a polynomial formula. Based on this structure, we set up a network capable of identifying the regions and their associated polynomials, thereby effectively generating a conjecture for the correct cohomology formula. For complex surfaces, we also set up a network which learns certain rigid divisors which appear in a recently discovered master formula for cohomology dimensions.
The awareness of the Jordanian population about OTC medications: A cross‐sectional study
Authors: Taybeh Esra’ , Al‐Alami Zina , Alsous Mervat , Rizik Mai , Alkhateeb Zakaria
Published: December 2019

Due to the shortage of literature related to the safe use of over‐the‐counter (OTC) products by patients worldwide, the aim of this study was to evaluate people's knowledge and attitudes regarding the use of OTC products in Jordan. Using an internet‐based questionnaire mainly spread through social media platforms, a descriptive cross‐sectional study was conducted with Jordanian candidates who consume OTC products. A total of 274 OTC product users answered the survey questions. The results showed that analgesics were the most commonly used OTC products among the participants (50.4%). The majority used the OTC products only as needed rather than on a regular basis. Only 42.4% of the participants sought a pharmacist's help in determining the dose of the OTC medicine. Most of the participants were very interested in reading a patient information leaflet (80.3%) and the side effects and contraindications (89.5%). The majority of participants agreed that antibiotics have to be prescribed (68.5%), and anti‐allergy medications should not be used as sleep aid medications (75.0%). About 53.4% thought that OTCs are sometimes enough to treat their health conditions without the need to follow‐up with a physician. A chi‐square analysis showed an association between gender, age, educational level and having a family member in the medical field and OTC products knowledge among Jordanians. Females, for example, were more interested in reading leaflet, checking production and expiry dates, knowing adverse effects, and appropriate storage conditions (P < .001, 0.022, 0.003, 0.007, respectively). We concluded that a good level of knowledge on the use of OTC products among the study population was identified in the present study.
How environmental orientation influences firm performance: The missing link of green supply chain integration
Authors: Zhou Cong , Xia Weili , Feng Taiwen , Jiang Jijiao , He Qingsong
Published: December 2019

Although the importance of environmental orientation has been recognized, how it affects firm performance remains unclear. Drawing on resource dependence theory, we explore how environmental orientation affects firm performance via green supply chain integration and the moderating effect of technology turbulence. We test hypotheses using hierarchical regression analysis by collecting data from 264 Chinese firms. The results reveal that both external environmental orientation and internal environmental orientation are positively related to green supply chain integration. Furthermore, green supply chain integration partially mediates the relationships between external environmental orientation and two types of firm performance and fully mediates the relationships between internal environmental orientation and two types of firm performance. The results also indicate that technology turbulence negatively moderates the relationship between internal environmental orientation and green supply chain integration and positively moderates that between external environmental orientation and green supply chain integration. This article contributes to green supply chain integration theory and practices by providing novel insights into how environmental orientation influences firm performance.
tRNA introns: Presence, processing, and purpose
Authors: Schmidt Casey A. , Matera A. Gregory
Published: December 2019

The presence of introns in both protein‐coding and noncoding RNA transcripts is a fascinating phenomenon. It seems counterintuitive that an organism would devote precious time and energy to removing a nucleic acid sequence that will not be present in the final product. Nevertheless, introns (including self‐splicing ones) are clearly important components of the basic cellular process of gene expression. Transfer RNA (tRNA) introns have been detected in all three kingdoms of life, and their precise removal is crucial for tRNA function. Of particular interest to this review are the tRNA intronic circular RNAs (tricRNAs) that form during metazoan tRNA splicing. In animal cells, these ultrastable introns form a novel class of noncoding RNA. Here, we summarize established knowledge and describe new findings in the field of tRNA splicing.

This article is categorized under:

RNA Processing > Splicing Mechanisms

RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems

RNA in Disease and Development > RNA in Disease

RNA Processing > tRNA Processing
Two New Coordination Polymers with UO22+ Units and Fluorinated Aromatic Carboxylate Linkers
Authors: Christoffels Ronja , Ruschewitz Uwe
Published: December 2019

A new coordination polymer, namely 2∞[(UVIO2)2(L)(DMA)3] (1) (C2/c, Z = 8) with L = 4‐monofluorobiphenyl‐3,3',5,5'‐tetracarboxylate (4‐mF‐BPTC4–) was synthesized by solvothermal reaction in DMA (N,N'‐dimethylacetamide). Its crystal structure was solved and refined from single‐crystal X‐ray diffraction data. It contains two different types of UO22+ units, which are connected by fluorinated tetracarboxylate ligands to form a layered structural motif. Three DMA molecules are coordinated to one UO22+ unit (CN = 7), whereas the other is solely coordinated by oxygen atoms of the tetracarboxylate linkers (CN = 8). The layers are held together by van der Waals interactions, which do not include any hydrogen bonds. An isostructural coordination polymer is formed with L' = 4,4'‐difluorobiphenyl‐3,3',5,5'‐tetracarboxylate (4,4'‐dF‐BPTC4–), as confirmed by XRPD (X‐ray powder diffraction), IR/Raman spectroscopy and elemental analysis. The DSC/TG analyses of both compounds show that they are stable up to approx. 300 °C in an inert argon atmosphere.
Views of veterinarians and meat inspectors concerning the practical application of visual meat inspection on domestic pigs in Finland
Authors: Laukkanen-Ninios Riikka , Rahkila Riitta , Oivanen Leena , Wirta Eeva-Riitta , Fredriksson-Ahomaa Maria
Published: December 2019

The post-mortem inspection of domestic pigs within the European Union was revised in 2014, primarily to include visual meat inspection of each carcase and offal. Palpations and incisions were removed from routine meat inspection procedures, as they are mostly used to detect pathological lesions caused by organisms irrelevant for public health, and instead can cause cross-contamination of carcases with foodborne pathogens. However, examination of all external surfaces of the carcase and organs, declaration of patho-physiological lesions as unfit for human consumption, and possibility for minimal handling of carcases and offals were held in place. In addition, the European Food Safety Authority suggested that palpation and incisions should be performed outside the slaughter line, but this was not incorporated in the revised legislation. We surveyed in 2014 the opinions of meat inspectors and veterinarians using an online questionnaire to determine what practical measures are required for the visual meat inspection procedure and when meat inspection staff consider additional palpations and incisions necessary. Based on the survey, turning the carcase and organs or technical arrangements such as mirrors were seen necessary to view all external surfaces. In addition, the pluck set cannot be trimmed on the side line. Local lesions, such as abscesses and lesions in the lymph nodes, signs of systemic infection and lymphoma, were the major lesions requiring additional post-mortem meat inspection procedures. Meat inspection personnel raised concerns on the poor quality of food chain information and export requirements demanding palpations and incisions. The efficient use of visual meat inspection requires legislation to better support the implementation and application of it, changes in the slaughter line layout and a possibility to classify incoming pig batches based on their risk.
Behind the pathology of macrophage-associated demyelination in inflammatory neuropathies: demyelinating Schwann cells
Authors: Park Hwan Tae , Kim Young Hee , Lee Kyung Eun , Kim Jong Kuk
Published: December 2019

In inflammatory peripheral demyelinating disorders, demyelination represents segmental demyelination in which the myelin sheath of a myelinating Schwann cell (SC) is completely removed by macrophages or a partial myelin degeneration in the paranode occurring due to autoantibodies attacking the node/paranode. For the segmental demyelination from living myelin-forming SCs, macrophages infiltrate within the endoneurium and insinuate between myelin lamellae and the cytoplasm of SCs, and the myelin is then removed via phagocytosis. During the macrophage invasion into the SC cytoplasm from the node of Ranvier and internodal areas, the attacked SCs do not remain quiescent but transdifferentiate into inflammatory demyelinating SCs (iDSCs), which exhibit unique demyelination pathologies, such as myelin uncompaction from Schmidt-Lanterman incisures with myelin lamellae degeneration. The longitudinal extension of this self-myelin clearance process of iDSCs into the nodal region is associated with the degeneration of nodal microvilli and paranodal loops, which provides a potential locus for macrophage infiltration. In addition to the nodal intrusion, macrophages appear to be able to invade fenestrated internodal plasma membrane or the degenerated outer mesaxon of iDSC. These SC demyelination morphologies indicate that the SC reprogramming to iDSCs may be a prerequisite for macrophage-mediated inflammatory demyelination. In contrast, paranodal demyelination caused by autoantibodies to nodal/paranodal antigens does not result in iDSC-dependent macrophage infiltration and subsequent segmental demyelination. In the context of inflammatory demyelination, the novel perspective of iDSCs provides an important viewpoint to understand the pathophysiology of demyelinating peripheral neuropathies and establish diagnostic and therapeutic strategies.
Agonist-specific desensitization of PGE2-stimulated cAMP signaling due to upregulated phosphodiesterase expression in human lung fibroblasts
Authors: Nunez Francisco J. , Schulte Nancy A. , Fogel David M. , Michalski Joel , Rennard Stephen I. , Penn Raymond B. , Toews Myron L. , Ostrom Rennolds S
Published: December 2019

Pulmonary fibrosis is characterized by fibroblasts persisting in an activated form, producing excessive fibrous material that destroys alveolar structure. The second messenger molecule cyclic 3′,5′-adenosine monophosphate (cAMP) has antifibrotic properties, and prostaglandin E2(PGE2) can stimulate cAMP production through prostaglandin E (EP)2and EP4receptors. Although EP receptors are attractive therapeutic targets, the effects of long-term exposure to PGE2have not been characterized. To determine the effects of long-term exposure of lung fibroblasts to PGE2, human fetal lung (HFL)-1 cells were treated for 24 h with 100 nM PGE2or other cAMP-elevating agents. cAMP levels stimulated by acute exposure to PGE2were measured using a fluorescent biosensor. Pretreatment for 24 h with PGE2shifted the concentration-response curve to PGE2rightward by approximately 22-fold but did not affect responses to the beta-adrenoceptor agonist isoproterenol. Neither isoproterenol nor forskolin pretreatment altered PGE2responses, implying that other cAMP-elevating agents do not induce desensitization. Use of EP2- and EP4-selective agonists and antagonists suggested that PGE2-stimulated cAMP responses in HFL-1 cells are mediated by EP2receptors. EP2receptors are resistant to classical mechanisms of agonist-specific receptor desensitization, so we hypothesized that increased PDE activity mediates the loss of signaling after PGE2pretreatment. PGE2treatment upregulated messenger RNA for PDE3A, PDE3B, PDE4B, and PDE4D and increased overall PDE activity. The PDE4 inhibitor rolipram partially reversed PGE2-mediated desensitization and PDE4 activity was increased, but rolipram did not alter responses to isoproterenol. The PDE3 inhibitor cilostazol had minimal effect. These results show that long-term exposure to PGE2causes agonist-specific desensitization of EP2receptor-stimulated cAMP signaling through the increased expression of PDE isozymes, most likely of the PDE4 family.
Staging and quantification of florbetaben PET images using machine learning: impact of predicted regional cortical tracer uptake and amyloid stage on clinical outcomes
Authors: Kim Jun Pyo , Kim Jeonghun , Kim Yeshin , Moon Seung Hwan , Park Yu Hyun , Yoo Sole , Jang Hyemin , Kim Hee Jin , Na Duk L. , Seo Sang Won , Seong Joon-Kyung
Published: December 2019

Purpose

We developed a machine learning–based classifier for in vivo amyloid positron emission tomography (PET) staging, quantified cortical uptake of the PET tracer by using a machine learning method, and investigated the impact of these amyloid PET parameters on clinical and structural outcomes.

Methods

A total of 337 18F-florbetaben PET scans obtained at Samsung Medical Center were assessed. We defined a feature vector representing the change in PET tracer uptake from grey to white matter. Using support vector machine (SVM) regression and SVM classification, we quantified the cortical uptake as predicted regional cortical tracer uptake (pRCTU) and categorised the scans as positive and negative. Positive scans were further classified into two stages according to the striatal uptake. We compared outcome parameters among stages and further assessed the association between the pRCTU and outcome variables. Finally, we performed path analysis to determine mediation effects between PET variables.

Results

The classification accuracy was 97.3% for cortical amyloid positivity and 91.1% for striatal positivity. The left frontal and precuneus/posterior cingulate regions, as well as the anterior portion of the striatum, were important in determination of stages. The clinical scores and magnetic resonance imaging parameters showed negative associations with PET stage. However, except for the hippocampal volume, most outcomes were associated with the stage through the complete mediation effect of pRCTU.

Conclusion

Using a machine learning algorithm, we achieved high accuracy for in vivo amyloid PET staging. The in vivo amyloid stage was associated with cognitive function and cerebral atrophy mostly through the mediation effect of cortical amyloid.
Novel prognostic model for stratifying survival in stage I lung adenocarcinoma patients
Authors: Liu Di-Han , Ye Zheng-Hao , Chen Si , Sun Xue-Song , Hou Jing-Yu , Zhao Ze-Rui , Long Hao
Published: December 2019

Purpose

We combined conventional clinical and pathological characteristics and pathological architectural grading scores to develop a prognostic model to identify a specific group of patients with stage I lung adenocarcinomas with poor survival following surgery.

Methods

This retrospective study included 198 patients with stage I lung adenocarcinomas recruited from 2004 to 2013. Multivariate analyses were used to confirm independent risk factors, which were checked for internal validity using the bootstrapping method. The prognostic scores, derived from β-coefficients using the Cox regression model, classified patients into high- and low-risk groups. The predictive performance and discriminative ability of the model were assessed by the area under the receiver operating characteristic curve (AUC), concordance index (C-index) and Kaplan–Meier survival analyses.

Results

Three risk factors were identified: T2 (rounding of β-coefficients = 81), necrosis (rounding of β-coefficients = 67), and pathological architectural score of 5–6 (rounding of β-coefficients = 58). The final prognostic score was the sum of points. The derived prognostic scores stratified patients into low- (score ≤ 103) and high- (score > 103) risk groups, with significant differences in 5-year overall survival (high vs. low risk: 49.3% vs. 88.0%, respectively; hazard ratio: 4.55; p < 0.001). The AUC for the proposed model was 0.717. The C-index of the model was 0.693.

Conclusion

An integrated prognostic model was developed to discriminate resected stage I adenocarcinoma patients into low- and high-risk groups, which will help clinicians select individual treatment strategies.
Recent disruptions in the timing and intensity of precipitation in Calakmul, Mexico
Authors: Mardero Sofia , Schmook Birgit , Christman Zachary , Metcalfe Sarah E. , De la Barreda-Bautista Betsabé
Published: December 2019

This study addresses changes in the timing and intensity of precipitation from 1982 to 2016 from three meteorological stations around Calakmul, Mexico, a landscape balancing biodiversity conservation and smallholder agricultural production. Five methods were used to assess changes in precipitation: the Mann-Kendall test of annual and wet season trends; a fuzzy-logic approach to determine the onset of the rainy season; the Gini Index and Precipitation Concentration Index (PCI) to evaluate the temporal distribution of precipitation; Simple Precipitation Intensity Index (SDII) to evaluate precipitation intensity; and the Rainfall Anomaly Index (RAI) to identify the deficit or surplus of rainfall compared with the long-term mean. Overall, rainfall trends in Calakmul over this period indicate a slight increase, though results of the indices (Gini, SDII, PCI) all indicate that rainfall has become more intense and more unevenly distributed throughout the year. There was no significant trend in the onset date of rainfall or the RAI overall, though there were more pronounced crests and troughs from 2004 to 2016. Higher interannual variability and more pronounced rainfall anomalies, both positive and negative, suggest that rainfall in the Calakmul region has become more extreme. This research informs for management and livelihood strategies in the local region and offers insights for analyses of regional patterns of seasonal precipitation events in tropical landscapes worldwide.