bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased dairy farm methane concentrations linked to anaerobic digester in a five‐year study
Authors: Debruyn Zachary , VanderZaag Andrew , Wagner‐Riddle Claudia
Published: January 2020

Organic waste materials are sources of anthropogenic methane (CH4) emissions. Anaerobic digestion (AD) is a technology that produces biogas from organic waste materials, and CH4 is the primary component of biogas. Unintended emission of CH4 from biogas facilities could undercut the environmental benefits of this technology. The objective of this study was to determine if the implementation of an AD system affected ambient CH4 concentrations ([CH4]) on a commercial dairy farm over 5 yr, from before installation into full operation. Concentrations at 4.5‐m height on a tower receiving wind that originated from various directions, comprising components of the dairy farm such as the AD facility, crop fields, or main barn, were measured using a closed‐path tunable diode laser trace‐gas analyzer. In 2012 and 2013, the first 2 yr of AD operation, [CH4] was not significantly different than pre‐AD levels in 2011 (2.04 ± 0.01 μl L−1). However, mean [CH4] increased to 2.47 ± 0.03 and 2.48 ± 0.04 μl L−1 in 2014 and 2015, respectively, and the occurrence of high [CH4] (>10 μl L−1) increased from <0.05% in Year 1 (pre‐AD) to 12% in Years 4 and 5. These elevated concentrations were related to an increased use of food waste feedstocks over time and suggest that the biogas system was a source of fugitive CH4 emissions. Food waste materials have a high biogas potential and are a valuable resource that require appropriate facility design and management to fully harness their benefits.
Microwave‐assisted synthesis and biological evaluation of new thiazolylhydrazone derivatives as tyrosinase inhibitors and antioxidants
Authors: Zhang Yu , Fu Xi , Yan Yangting , Liu Jinbing
Published: January 2020

In this work, we have synthesized a series of 2‐thiazolylhydrazone derivatives (1–27) and investigated their biological activities as tyrosinase inhibitors and antioxidants. Some compounds showed potent tyrosinase inhibitory activities and 4‐(2‐(2‐(1‐(4‐Aminophenyl)ethylidene)‐hydrazinyl)thiazol‐4‐yl) phenol (26) showed more potent inhibitory effect than the standard tyrosinase inhibitor kojic acid (IC50: 9.8 μM vs. 23.6 μM). Compounds 2, 14, and 26 exhibited high antioxidant activities in 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azinobis (3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) assays. The structure–activity relationship (SAR) indicated that the substitutions of bromine, hydroxyl group, and amino groups cause great effect to the inhibition effect against tyrosinase. The mechanism and kinetic studies demonstrated that the inhibitory effect of compound 26 on the tyrosinase by acting as the reversible and uncompetitive inhibitor. Docking studies suggests that compound 26 interacts strongly with mushroom tyrosinase via hydrogen bonding.
Synthesis and Transformation of 4‐(1‐Chloro‐1‐nitroethyl)‐6,7‐dimethoxy‐2‐methylquinazoline: Spectral Characterization and Anti‐cancer Properties of some Novel Quinazoline Derivatives
Authors: Hoan Duong Quoc , Hoa Le Thi , Huan Trinh Thi , Dinh Nguyen Huu
Published: January 2020

An efficient and simple method has been reported for the synthesis of 4‐(1‐Chloro‐1‐nitroethyl)‐6,7‐dimethoxy‐2‐methylquinazoline (2) as a key compound for further transformation to other novel 6,7‐dimethoxy‐2‐methyl‐4‐substituted quinazolines. The structure of the synthesized compounds was characterized by spectroscopic methods. The pathway of some unprecedented reactions was proposed. (E)‐1‐(6,7‐dimethoxy‐2‐methylquinazolin‐4‐yl)‐3‐(4‐nitrophenyl)prop‐2‐en‐1‐one (11) exhibits high in vitro cytotoxicity on three cell lines, Hepatocellular carcinoma (Hep‐G2), Human lung carcinoma (LU‐1), and Human breast carcinoma (MCF‐7) with IC50 of 2.1, 11.6 and 2.2 μM, respectively.
T3P‐promoted synthesis of a series of novel 3‐aryl‐2‐phenyl‐2,3‐dihydro‐4H‐1,3‐benzothiazin‐4‐ones
Authors: Silverberg Lee J. , Pacheco Carlos , Sahu Debashish , Scholl Peter , Sobhi Hany F. , Bachert Joshua T. , Bandholz Kaitlyn , Bendinsky Ryan V. , Bradley Heather G. , Colburn Baylee K. , Coyle David J. , Dahl Jonathon R. , Felty Megan , Fox Ryan F. , Gonzalez Kyanna M. , Islam Jasra M. , Koperna Stacy E. , Moyer Quentin J. , Noble Duncan J. , Ramirez Melissa E. , Yang Ziwei
Published: January 2020

A series of 11 novel 3‐aryl‐2‐phenyl‐2,3‐dihydro‐4H‐1,3‐benzothiazin‐4‐ones was prepared at room temperature by T3P‐mediated cyclization of N‐aryl‐C‐phenyl imines with thiosalicylic acid. This provides simple and ready access to N‐aryl compounds in this family, which have been generally difficult to prepare.
Gr1 makes an unexpected cameo appearance in eosinophils
Authors: Lacy Paige
Published: January 2020

Discussion of the neutrophil marker Ly6G/Gr1, which is readily detectable on mouse eosinophils, and is expressed in higher levels in the presence of IL-5.
Preexisting malignancy abrogates the beneficial effects of CXCR4 blockade during sepsis
Authors: Zhang Wenxiao , Chihade Deena B. , Xie Jianfeng , Chen Ching-wen , Ramonell Kimberly M. , Liang Zhe , Coopersmith Craig M. , Ford Mandy L.
Published: January 2020

Patients with cancer are at an increased risk of developing and dying from sepsis. We previously reported that blockade of the chemokine receptor CXCR4 resulted in decreased CD4+ T cell exhaustion and improved survival in a model of polymicrobial sepsis in previously healthy mice. Here, we sought to determine whether CXCR4 blockade could improve mortality and immune dysregulation during sepsis complicated with malignancy. Results in animals inoculated with a lung cancer cell line and subjected to CLP 3 weeks later indicated that CXCR4 was up-regulated on naïve and central memory T cells following sepsis. Of note, and in contrast to results in previously healthy mice, CXCR4 blockade failed to improve survival in cancer septic animals; instead, it actually significantly worsened survival. In the setting of cancer, CXCR4 blockade failed to result in T cell egress from the bone marrow, reverse lymphopenia in the spleen, or reverse T cell exhaustion. Mechanistically, elevated expression of CD69 on naïve T cells in the bone marrow of cancer septic animals was associated with their inability to egress from the bone marrow in the setting of CXCR4 blockade. In conclusion, these results illuminate the differential impact of CXCR4 blockade on sepsis pathophysiology in the setting of cancer and highlight the need for personalized therapy during sepsis.
Development of an automated, GMP compliant FASTlab™ radiosynthesis of [18F]GE‐179 for the clinical study of activated NMDA receptors
Authors: Khan Imtiaz , Berg Tom Christian , Brown Jane , Bhalla Rajiv , Wilson Anthony , Black Andrew , McRobbie Graeme , Nairne James , Olsson Andreas , Trigg William
Published: January 2020

N‐(2‐chloro‐5‐(S‐2‐[18F]fluoroethyl)thiophenyl)‐N'‐(3‐thiomethylphenyl)‐N'‐methylguanidine, ([18F]GE‐179), has been identified as a promising positron emission tomography (PET) ligand for the intra‐channel phencyclidine (PCP) binding site of the N‐methyl‐D‐aspartate (NMDA) receptor. The radiosynthesis of [18F]GE‐179 has only been performed at low radioactivity levels. However, the manufacture of a GMP compliant product at high radioactivity levels was required for clinical studies. We describe the development of a process using the GE FASTlab™ radiosynthesis platform coupled with HPLC purification. The radiosynthesis is a two‐step process, involving the nucleophilic fluorination of ethylene ditosylate, 11, followed by alkylation to the deprotonated thiol precursor, N‐(2‐chloro‐5‐thiophenol)‐N'‐(3‐thiomethylphenyl)‐N'‐methyl guanidine, 8. The crude product was purified by semi‐preparative HPLC to give the formulated product in an activity yield (AY) of 7 ± 2% (n = 15) with a total synthesis time of 120 minutes. The radioactive concentration (RAC) and radiochemical purity (RCP) were 328 ± 77 MBq/mL and 96.5 ± 1% respectively and the total chemical content was 2 ± 1 μg. The final formulation volume was 14 mL. The previously described radiosynthesis of [18F]GE‐179 was successfully modified to deliver an process on the FASTlab™ that allows the manufacture of a GMP quality product from high starting radioactivitity (up to 80 GBq) and delivers a product suitable for clinical use.
Pre‐school neurocognitive and functional outcomes after liver transplant in children with early onset urea cycle disorders, maple syrup urine disease, and propionic acidemia: An inception cohort matched‐comparison study
Authors: Jain‐Ghai Shailly , Joffe Ari R. , Bond Gwen Y. , Siriwardena Komudi , Chan Alicia , Yap Jason Y. K. , Hajihosseini Morteza , Dinu Irina A. , Acton Bryan V. , Robertson Charlene M. T. ,   the Western Canadian Complex Pediatric Therapies Follow‐up Group
Published: January 2020

Background

Urea cycle disorders (UCD) and organic acid disorders classically present in the neonatal period. In those who survive, developmental delay is common with continued risk of regression. Liver transplantation improves the biochemical abnormality and patient survival is good. We report the neurocognitive and functional outcomes post‐transplant for nine UCD, three maple syrup urine disease, and one propionic acidemia patient.

Methods

Thirteen inborn errors of metabolism (IEM) patients were individually one‐to‐two matched to 26 non‐IEM patients. All patients received liver transplant. Wilcoxon rank sum test was used to compare full‐scale intelligence‐quotient (FSIQ) and Adaptive Behavior Assessment System‐II General Adaptive Composite (GAC) at age 4.5 years. Dichotomous outcomes were reported as percentages.

Results

FSIQ and GAC median [IQR] was 75 [54, 82.5] and 62.0 [47.5, 83] in IEM compared with 94.5 [79.8, 103.5] and 88.0 [74.3, 97.5] in matched patients (P‐value <.001), respectively. Of IEM patients, 6 (46%) had intellectual disability (FSIQ and GAC <70), 5 (39%) had autism spectrum disorder, and 1/13 (8%) had cerebral palsy, compared to 1/26 (4%), 0, 0, and 0% of matched patients, respectively. In the subgroup of nine with UCDs, FSIQ (64[54, 79]), and GAC (56[45, 75]) were lower than matched patients (100.5 [98.5, 101] and 95 [86.5, 99.5]), P = .005 and .003, respectively.

Conclusion

This study evaluated FSIQ and GAC at age 4.5 years through a case‐comparison between IEM and matched non‐IEM patients post‐liver transplantation. The neurocognitive and functional outcomes remained poor in IEM patients, particularly in UCD. This information should be included when counselling parents regarding post‐transplant outcome.
Parenteral Nutrition–Dependent Children With Short‐Bowel Syndrome Lack Duodenal‐Adaptive Hyperplasia but Show Molecular Signs of Altered Mucosal Function
Authors: Sanaksenaho Galina , Mutanen Annika , Godbole Nimish , Kyrönlahti Antti , Koivusalo Antti , Lohi Jouko , Pihlajoki Marjut , Heikinheimo Markku , Pakarinen Mikko P.
Published: January 2020

Background

Although adaptive mucosal growth of the remaining small intestine is an essential compensatory mechanism to bowel resection in experimental short‐bowel syndrome (SBS), only scarce clinical data are available. We studied structural and molecular mechanisms of intestinal adaptation in children with SBS.

Methods

: Fourteen patients, who had been dependent on parenteral nutrition (PN) since neonatal period for a median (interquartile range)1.4 (0.7–6.5) years, were studied at the age of 1.5 (1.0–6.5) years. Median length of remaining small bowel was 33 (12–60) cm, and 6 patients had their ileocecal valve preserved. Six children without gastrointestinal disorders served as age‐matched and gender‐matched controls. All patients underwent duodenal biopsies. Mucosal microarchitecture, proliferation, apoptosis, inflammation, and epithelial‐barrier function were addressed using histology, immunohistochemistry, and quantitative real‐time polymerase chain reaction.

Results

: Villus height, crypt depth, enterocyte proliferation, and apoptosis were similar in patients and matched controls. Messenger RNA (mRNA) expression of numerous genes regulating gut epithelial‐barrier function (TGFB2, CAV1, CLDN1, MUC2, and NLRC4) was significantly altered. Of various nutrient transporters studied, only expression of SLC2A1 encoding facilitative glucose transporter GLUT1 was increased among patients, whereas RNA expression of genes encoding sodium‐dependent glucose, sterol, fatty‐acid, and peptide transport remained unchanged.

Conclusion

: Duodenal mucosal hyperplasia has a limited role in mediating physiological adaptation following intestinal resection among PN‐dependent children with SBS. Further clinical studies addressing functional significance of the observed alterations in mucosal RNA expression are warranted.
Rheumatoid arthritis and periodontitis in adults: Using the Korean National Health Insurance Service‒National Sample Cohort
Authors: Lee Kyeong Hee , Choi Yoon Young
Published: January 2020

Background

Using the database of the National Health Insurance Service–National Sample Cohort (NHIS–NSC), we aimed to assess the relationship between the prevalence of rheumatoid arthritis (RA) and periodontitis.

Methods

Participants aged ≥19 years with a previous health check‐up at the NHIS between 2009 and 2015 were selected. In total, 559,280 participants were included after implementing appropriate exclusion criteria. The Chi‐squared test was used to compare the general and health‐related characteristics of participants with and without RA or periodontitis. Univariate and multivariate logistic regression analyses with consecutive adjustment for confounders, were used to assess the association between the prevalence of rheumatoid arthritis and periodontitis.

Results

The prevalence of rheumatoid arthritis in patients with and without periodontitis was 6.2% and 5.2%, respectively. The prevalence of periodontitis in patients with and without rheumatoid arthritis was 19.6% and 16.6%, respectively. The possibility of having rheumatoid arthritis was greater in patients with periodontitis than in individuals without periodontitis (odds ratio [OR]; 1.22, P <0.001), and remained high (OR; 1.07, P <0.001) after adjusting for confounders.

Conclusion

Our results revealed a significant association between the prevalence of rheumatoid arthritis and periodontitis.
Vibrational Raman optical activity of camphor: The importance of electric‐dipole—electric‐quadrupole polarizability contribution
Authors: Johnson Jordan L. , Zajac Grzegorz , Baranska Malgorzata , Polavarapu Prasad L.
Published: January 2020

The importance of the electric‐dipole—electric‐quadrupole polarizability contribution to the vibrational Raman optical activity (VROA) and dimensionless circular intensity difference spectra of (1S)‐camphor is examined. The spectra are simulated with and without this tensor contribution using density functional theory calculations, and similarity is evaluated for each against the experimental spectra. Careful examination of the comparison between experimental and calculated spectra reveals multiple vibrational bands, in the ~1,130–950 cm−1 region, originating from −C–H bending vibrations that are dominated by the electric‐dipole—electric‐quadrupole polarizability contributions. The similarity overlap analysis also reveals that the similarity overlap between experimental and predicted spectra in the measured spectral range increases, by up to 12%, when electric‐dipole—electric‐quadrupole polarizability contributions are included. The negative VROA band at 1,125 cm−1 in the experimental spectrum of (1S)‐(‐)‐camphor can only be reproduced in the predicted spectra when electric‐dipole—electric‐quadrupole polarizability contribution is included. Investigations on additional molecules indicated that (a) two experimental VROA bands of (1S,4R)‐(+)‐fenchone at ~1,740 and 220 cm−1 originate from dominating electric‐dipole—electric‐quadrupole polarizability contribution and (b) the symmetric and antisymmetric ring deformation modes of dimethyloxirane have dominating electric‐dipole—electric‐quadrupole polarizability contribution. These observations establish the importance of electric‐dipole—electric‐quadrupole polarizability contribution to VROA for the first time.
Two‐stage degradation in n‐channel LTPS‐TFTs under negative and positive bias stresses
Authors: Guo Jian , Yu Zhinong , Yan Wei , Shi Dawei , Xue Jianshe , Xue Wei
Published: January 2020

Device degradation behaviors of n‐channel low‐temperature polycrystalline silicon thin film transistors under negative bias stress and positive bias stress were investigated. It was found that the threshold‐voltage has a two‐stage degradation, shifting to different direction with time. The mobility and the subthreshold swing SS both show a dependence on the stress time. It was determined that the interface trap states, the grain boundary trap states, and electron trapping together dominate the time‐dependent degradation behaviors. The trap is caused by the rupture of Si─H and Si─O bonds. A comprehensive model is proposed to explain the time‐dependent degradation behaviors clearly. In addition, after removing the stress, the recovery behaviors of threshold voltage Vth can be observed, which provide the evidence supporting the degradation model proposed.
Synthesis of multidentate functional monomer for ion imprinting
Authors: Chen Liangqun , Liang Hongbing , Xing Jun
Published: January 2020

In this work, N,N,N‐tri(2‐carboxyethyl)‐3‐(2‐aminoethylamino)propyl‐trimethoxysilane was prepared as a multidentate functional monomer. The 3D model of the monomer coordinating with Cu2+ indicated that the monomer is able to provide five ligating atoms like ethylenediaminetetraacetic acid‐Cu2+ to complex with Cu2+. When Cu2+ was used as a template ion, the synthesis conditions of Cu2+‐imprinted polymers were optimized upon orthogonal design. It is interesting to find that Cu2+‐imprinted polymer offers a selectivity coefficient of 192.2 when the molar ratio of Cu2+ to monomer was exactly 1:1. That means there is no excess ligating atom in the ion‐imprinted polymer and therefore, the nonspecific adsorption could be avoided. Benefiting from the excellent selectivity of Cu2+‐imprinted polymer, even if the concentration of Zn2+ was 25 times that of Cu2+, Cu2+‐imprinted polymer still affords a high selectivity coefficient. Finally, the optimal synthesis conditions for Cu2+‐imprinted polymer, except the pH, were adopted to prepare Ni2+‐imprinted polymer, and Ni2+‐imprinted polymer also offered satisfying selectivity to Ni2+. That implies this multidentate monomer is adaptable in ion imprinting and, the optimal synthesis conditions of Cu2+‐imprinted polymer except pH are likely suitable for the imprinting of other ions besides Cu2+.
Genetic Testing for Congenital Bilateral Hearing Loss in the Context of Targeted Cytomegalovirus Screening
Authors: Peterson Joseph , Nishimura Carla , Smith Richard J. H.
Published: January 2020

Objectives/Hypothesis

To determine the prevalence of children with genetic hearing loss who are cytomegalovirus (CMV) positive at birth and the relative proportion of genetic and CMV etiology among children with congenital bilateral hearing loss.

Study Design

Database review.

Methods

We performed a review of clinical test results for patients undergoing comprehensive genetic testing for all known hearing loss–associated genes from January 2012 to January 2019. This population was reviewed for reported CMV status and genetic causes of congenital bilateral hearing loss.

Results

In the OtoSCOPE database, 61/4,282 patients were found to have a documented CMV status, and 661/4282 had documented bilateral congenital hearing loss. Two patients were identified who had both a positive CMV result and a genetic cause for their hearing loss. Forty‐eight percent of patients with bilateral congenital hearing loss (320/661) were found to have a genetic etiology. In 62% (198/320), the hearing loss was associated with pathogenic variants in GJB2, STRC, SLC26A4 or an Usher syndrome–associated gene.

Conclusions

We estimate that ~2% of CMV‐positive newborns with hearing loss have a known genetic variant as a cause. The subcohort of CMV‐positive newborns with symmetric mild‐to‐moderate bilateral hearing loss will have at least a 7% chance of having pathogenic gene variants associated with hearing loss. In a CMV‐positive neonate who failed their newborn hearing screen bilaterally, genetic screening needs to be considered for accurate diagnosis and possible deferment of antiviral treatment.

Level of Evidence

4 Laryngoscope, 130:2714–2718, 2020
Tribochemical degradation of vacuum‐stable lubricants: A comparative study between multialkylated cyclopentane and perfluoropolyether in a vacuum ball‐on‐disc and full‐bearing tests
Authors: Kürten Dominik , Khader Iyas , Kailer Andreas
Published: January 2020

In this study, the decomposition of a multialkylated cyclopentane (MAC) and a perfluoro‐poly‐ether (PFPE) lubricant was investigated in a ball‐on‐disc sliding test under vacuum and in a rolling contact fatigue (RCF) test on full bearings. In situ mass spectrometry was conducted to study the tribochemical formation of hydrogen in a steel‐on‐steel ball‐on‐disc sliding contact. Further investigations on lubricant degradation in rolling‐sliding contact indicated fragmentation and oxidation reaction of the MAC oil by interaction with the oxide layer and the nascent bearing steel.Finite element method (FEM) analysis was carried out to model the contact in the ball‐on‐disc experiments and to extract contact surface temperature fields.

Post‐RCF hydrogen analysis of bearing components indicated increased hydrogen content in the samples lubricated with the MAC fluid. The RCF tests with PFPE did not indicate any signs of surface damage.
Experimental investigation on mechanical properties and wear characterization of Al‐Si12CulMg1 aluminium alloy reinforced with titanium diboride and boron carbide particulate hybrid composites using stir casting process
Authors: Vadivel P. , Velmurugan C. , Chelladurai S.J.S.
Published: January 2020

LM13 aluminium alloy (Al−Si12CulMg1) with titanium diboride (TiB2) and boron carbide (B4C) particulate hybrid composites have been prepared using stir casting process. Wt% of titanium diboride is varied from 0–10 and constant 5 wt% boron carbide particles have been used to reinforce LM13 aluminium alloy. Microstructure of the composites has been investigated and mechanical properties viz., hardness, the tensile strength of composites have been analyzed. Wear behavior of samples has been tested using a pin on disc apparatus under varying load (20 N–50 N) for a sliding distance of 2000 m. Fracture and wear on the surface of samples have been investigated. Microstructures of composites show uniform dispersion of particles in LM13 aluminium alloy. Hardness and tensile strength of composites increased with increasing wt % of reinforcements. Dry sliding wear test results reveal that weight loss of composites increased with increasing load and sliding distance. Fracture on the surface of composites reveals that the initiation of crack is at the interface of the matrix and reinforcement whereas dimples are observed for LM13 aluminium alloy. Worn surface of composites shows fine grooves and delamination is observed for the matrix.
A simple method for estimating the roundness of minimum zone circle
Authors: Huang Q. , Mei J. , Yue L. , Cheng R. , Zhang L. , Fang C. , Li R. , Chen L.
Published: January 2020

With the rapid development of micromachining technology, the feature size of object parts becomes smaller whilst the required tolerance accuracy becomes higher. The geometry of these micro‐parts must be critically verified at sub‐micrometer or even nanometer accuracy in three dimensions to guarantee machining quality, such as the cylindrical parts. Therefore, the method for estimating roundness error plays an increasingly important role in machining. This paper focuses on the roundness estimation based on the minimum zone circle method in a Cartesian coordinate system. An asymptotic search method is also proposed to obtain the coordinates of the concentric centre of the minimum zone circle model and to calculate the roundness error. Comparison and simulation experiments are also conducted to test the performance of the proposed method. The results demonstrate that the proposed method is effective, reliable and can meet the requirements for roundness estimation.
Factors influencing mechanical and wear performance of dental composite: A review
Authors: Kumar S.R. , Patnaik A. , Bhat I.K.
Published: January 2020

With environmental concerns, the development of a posterior restorative as a true alternative to dental amalgam is needed. Hence in this regard, the development of dental composites have gained more and more research interest, as they have the advantages of better aesthetic look, better physical, mechanical and tribological properties over the other available dental materials. In this study, the physical, mechanical and wear behavior of dental composite materials have been reviewed. Numerous experimental results, analytical studies and their significance were also discussed for various dental composite materials. The wear performances of dental composite materials depend up on various factors including oral environment, resin chemistry, filler technology and interfacial bonding strength etc. In oral environment, the presence of medium such as water, air, heptane, ethanol, artificial saliva etc. and durations up to which composite is kept such as seven days, one month or three months etc. affect the performance of dental composite. Abrasion and erosion are two major causes for the wear behavior of dental composite / human teeth. The major issue, most significant challenges and effect of each of those factors affecting the performance of dental composite materials were also presented along with some recommendation.
Investigation of three‐body wear behavior and hardness of experimental titanium alloys for dental applications in oral environment
Authors: Yilmaz E.Ç.
Published: January 2020

The aim of this study was to investigate the three‐body wear resistance and hardness of commercially pure titanium and titanium alloys containing zirconium and tantalum (cp‐Ti, Ti‐5Zr and Ti‐5Ta). Each titanium test group, were subjected to wear tests under 105 wear cycles, 50 N mechanical force, 2.0 Hz wear frequency, 6 mm diameter Al2O3 antagonist ball, 5 °C/55 °C thermal change conditions immersed in poppy seed slurry as third‐body medium. The mean wear volume loss and depth of all test specimens after the three‐body wear tests was determined with use non‐contact 3D profilometer and also Vicker's hardness was measured. Wear area of microstructures were evaluated using scanning electron microscopy (SEM) and x‐ray diffraction (XRD) analysis. The hardness of Ti‐5Zr material was significantly greater than the other alloy material and cp‐Ti. However, for the test materials in this study considered, correlations between the three‐body wear resistance and hardness were found to be insignificant. It was concluded, the three‐body wear resistance of the alloy formed with the adding of zirconium and tantalum to the pure titanium is increased after wear tests.
Effect of reduction rate and annealing temperature on texture evolution and magnetic properties of used non‐oriented silicon steel
Authors: Song S.X.
Published: January 2020

This paper discusses the method of improving the magnetic properties of used silicon steel by cold rolling and annealing process with used non‐oriented silicon steel as the object. The texture evolution and magnetic domain structure are also investigated. Experimental results show that the magnetic domain can be transformed vastly compared with the used silicon steel when the specimens are prepared through the same cold rolling and annealing conditions. The length of the magnetic wall and the density of magnetic domain per unit area are boosted, and the magnetic domain refinement is exceedingly apparent. Under the same annealing condition (at 950 °C for 5 min), the γ‐fiber is gradually decreased to 6.6 % and the {110} recrystallization texture is gradually enhanced with increased reduction from 28.3 % to 40 %. The intensity of the Goss texture reaches a maximum of 22.2. For the cold rolling reduction of 34.3 %, the γ‐fiber gradually decrease to 13.8 % and the {110} recrystallization texture is gradually enhanced with increase in the annealing temperature from 800 °C to 950 °C. Moreover, the intensity of Goss texture reaches 14. The sample prepared through 40 % reduction and annealing at 950 °C for 5 min exhibited the most desirable magnetic properties. The magnetic induction B50 value of the specimen is increased by 0.052 T, and the core loss P1.5/50 is reduced by 0.478 W/kg compared with the initial specimen.
Assessment of measurement uncertainty examining sustained load tests with bonded fasteners
Authors: Stierschneider E. , Schwenn M. , Zeman O. , Bergmeister K.
Published: January 2020

Dauerlastversuche sind im Zuge der Produktqualifizierung von Verbunddübeln erforderlich. Ziel dieser Dauerlastversuche ist die Beurteilung des Kriechverhaltens des Befestigungselements unter konstanter Zugbelastung. Auf Basis der Versuche wird eine Extrapolation des Verschiebungsverhaltens über die angenommene Lebensdauer des Befestigungselements vorgenommen. Drei verschiedene Messgrößen sind dabei von Interesse, dies sind die Bruchlast bei den Auszugsversuchen, die Gleichmäßigkeit der Aufbringung der Dauerlast sowie die Verschiebung. Da jede dieser Messgrößen mit Messunsicherheiten behaftet ist, wird im vorliegenden Beitrag auf die realistische Erfassung eben dieser eingegangen, um in der Folge das Verschiebungsverhalten über die Lebensdauer verbessert prognostizieren zu können. Die Bewertung der einzelnen Messunsicherheitsbeiträge erfolgt in Übereinstimmung mit dem „Guide to the expression of Uncertainty in Measurement“, sowohl für die maximal erwartbare Messunsicherheit bei Durchführung entsprechend den Genauigkeitsanforderungen der Prüfrichtlinien, als auch mit praxisnahen Werten.
Indirect taxation with shadow cost of public funds in mixed oligopoly
Authors: Zhang Qidi , Wang Leonard F.S. , Yang Yapo
Published: January 2020

We adopt a mixed oligopoly model, where a state‐owned welfare‐maximizing public firm competes with a profit‐maximizing private firm, to compare the welfare effects of the specific and ad valorem tax in the presence of the shadow cost of public funds. Following the assumption of most previous literature that total output is constant under specific and ad valorem taxation, we find that, when the shadow cost of public funds exists, the tax policy must be adjusted according to the privatization level of the public firm; if the privatization level is low (medium, high), the government needs to adopt ad valorem (specific, ad valorem) tax. Moreover, the private firm will earn a higher (lower) profit under ad valorem tax than under specific tax, if the public firm is not fully privatized and the shadow cost of public funds is high (low).
First maternal uniparental disomy for chromosome 2 with PREPL novel frameshift mutation of congenital myasthenic syndrome 22 in an infant
Authors: Zhang Ping , Wu Bingbing , Lu Yulan , Ni Qi , Liu Renchao , Zhou Wenhao , Wang Huijun
Published: January 2020

Background

Congenital myasthenic syndrome 22 (CMS22) is a rare autosomal recessive disorder due to isolated PREPL deficiency and characterized by neonatal hypotonia, muscular weakness, and feeding difficulties. Eight such cases have already been reported, while maternal uniparental disomy with a PREPL pathogenic mutation has never been involved.

Methods

Trio whole‐exome sequencing (WES), comparative genomic hybridization microarray (arry‐CGH), and Sanger sequencing were performed on a 6‐month‐old girl with severe neonatal hypotonia and feeding difficulties. Also, the phenotype and genotype of reported CMS22 patients were reviewed.

Results

In this female infant, we identified a novel homozygous frameshift mutation in PREPL (c.1282_1285delTTTG, p.Phe428Argfs*18) by trio‐WES. Sanger sequencing confirmed that her mother was heterozygous and her father was normal. Trio‐WES data showed that 96.70% (1668/1725) variants on chromosome 2 were homozygous and maternally inherited, suggesting maternal uniparental disomy of chromosome 2 [UPD(2)mat]. Array‐CGH did not show copy number variants (CNVs) but revealed complete UPD(2).

Conclusion

To date, nine patients with CMS22 have been reported including our patient, and we report the youngest and the first UPD(2)mat with PREPL novel homozygous pathogenic mutation case, which expand the mutation spectrum of PREPL gene.
Novel KLHL26 variant associated with a familial case of Ebstein’s anomaly and left ventricular noncompaction
Authors: Samudrala Sai Suma K. , North Lauren M. , Stamm Karl D. , Earing Michael G. , Frommelt Michele A. , Willes Richard , Tripathi Swarnendu , Dsouza Nikita R. , Zimmermann Michael T. , Mahnke Donna K. , Liang Huan Ling , Lund Michael , Lin Chien‐Wei , Geddes Gabrielle C. , Mitchell Michael E. , Tomita‐Mitchell Aoy
Published: January 2020

Background

Ebstein's anomaly (EA) is a rare congenital heart disease of the tricuspid valve and right ventricle. Patients with EA often manifest with left ventricular noncompaction (LVNC), a cardiomyopathy. Despite implication of cardiac sarcomere genes in some cases, very little is understood regarding the genetic etiology of EA/LVNC. Our study describes a multigenerational family with at least 10 of 17 members affected by EA/LVNC.

Methods

We performed echocardiography on all family members and conducted exome sequencing of six individuals. After identifying candidate variants using two different bioinformatic strategies, we confirmed segregation with phenotype using Sanger sequencing. We investigated structural implications of candidate variants using protein prediction models.

Results

Exome sequencing analysis of four affected and two unaffected members identified a novel, rare, and damaging coding variant in the Kelch‐like family member 26 (KLHL26) gene located on chromosome 19 at position 237 of the protein (GRCh37). This variant region was confirmed by Sanger sequencing in the remaining family members. KLHL26 (c.709C > T p.R237C) segregates only with EA/LVNC‐affected individuals (FBAT p < .05). Investigating structural implications of the candidate variant using protein prediction models suggested that the KLHL26 variant disrupts electrostatic interactions when binding to part of the ubiquitin proteasome, specifically Cullin3 (CUL3), a component of E3 ubiquitin ligase.

Conclusion

In this familial case of EA/LVNC, we have identified a candidate gene variant, KLHL26 (p.R237C), which may have an important role in ubiquitin‐mediated protein degradation during cardiac development.
Entropy generation in nanofluid flow of Walters‐B fluid with homogeneous‐heterogeneous reactions
Authors: Qayyum Sumaira , Hayat Tasawar , Jabeen Sumaira , Alsaedi Ahmed
Published: January 2020

Research on optimization of entropy generation in nanofluid flow gained much interest. In this study, the Walter's‐B nanofluid flow is considered to analyze the irreversibility in cubic autocatalysis. Fluid motion is considered in presence of viscous dissipation, magnetohydrodynamics (MHD), radiation, and heat generation absorption. Homotopy analysis method (HAM) is employed to solve nonlinear ordinary differential system. Results show that fluid flow reduces for larger Weissenberg and Hartman numbers. Temperature gradually enhances for larger Weissenberg number and radiation parameter. For higher estimation of thermophoresis parameter, the temperature and concentration are enhanced. Opposite impact of Hartman and Weissenberg numbers is noticed for entropy generation and Bejan number. Disorderedness and Bejan number are reduced near the sheet, while the opposite trend is seen away from the sheet.
A technique for reduction of mutual coupling by steering surface wave propagation
Authors: Ghosh Jeet , Mitra Debasis
Published: January 2020

In this article, we present an efficient approach to reduce mutual coupling in a planar slot antenna array by using high refractive index metamaterial. The metamaterial structure is employed to steer the propagation of the surface wave. For this purpose, array of complementary slot coupled split‐ring resonator structures are designed on the two sides of the slot array. The proposed configuration is fabricated and both simulation and measurement results confirm that an average of 10 dB improvements in isolation level is achieved throughout the wide operating bandwidth. Moreover, due to the implementation of the complementary metamaterial structure, the proposed configuration becomes planar and easy to fabricate.
Physical performance of a long axial field‐of‐view PET scanner prototype with sparse rings configuration: A Monte Carlo simulation study
Authors: Zein Sara A. , Karakatsanis Nicolas A. , Issa Mohammad , Haj‐Ali Amin A. , Nehmeh Sadek A.
Published: January 2020

Purpose

There is a growing interest in extending the axial fields‐of‐view (AFOV) of PET scanners. One major limitation for the widespread clinical adoption of such systems is the multifold increase in the associated material costs. In this study, we propose a cost‐effective solution to extend the PET AFOV using a sparse detector rings configuration. The corresponding physical performance was validated using Monte Carlo simulations.

Methods

Monte Carlo model of the Siemens BiographTM mCT PET/CT, with a 21.8 cm AFOV and a set of compact rings of LSO crystals was developed as a gold standard. The mCT configuration was then modified by interleaving the LSO crystals in the axial direction within each detector block with 4 mm physical gaps (equivalent to the LSO crystal axial dimension) thus extending the AFOV to 43.6 cm (Ex‐mCT). The physical performances of the two MC models were assessed and then compared using NEMA NU 2‐2007 standards.

Results

Ex‐mCT showed <0.2 mm difference in transaxial spatial resolution, and, 0.8 mm and 0.3 mm deterioration in axial spatial resolution, compared to the mCT, at 1 and 10 cm off‐center of the transaxial field‐of‐view respectively. The system sensitivities for the mCT and Ex‐mCT models were 9.4 ± 0.2 and 10.75 ± 0.2 cps/kBq respectively. The higher sensitivity of Ex‐mCT was due to four additional detector rings required to double the mCT AFOV. PET images of the NEMA Image Quality (IQ) phantom showed no artifacts due to detector rings sparsity, and all spheres were visible in both configurations. Ex‐mCT achieved percent contrast recoveries within 5.6% of those of the mCT for all spheres and a maximum of 36% higher background variability at the center of the AFOV. The Ex‐mCT, however, showed a more uniform noise distribution over an axial range of almost twice the length of the mCT AFOV.

Conclusions

Using the proposed sparse detector‐ring configuration, the AFOV of current generation PET systems can be doubled while maintaining the original number and volume of detector crystal elements, and without jeopardizing the system’s overall physical performance. Despite an increase in the noise level, the Ex‐mCT exhibited an improved noise uniformity.
Multi‐energy inter‐pixel coincidence counters for charge sharing correction and compensation in photon counting detectors
Authors: Taguchi Katsuyuki
Published: January 2020

Purpose

Smaller pixel sizes of x‐ray photon counting detectors (PCDs) are advantageous for count rate capabilities but disadvantageous for charge sharing. With charge sharing, the energy of an x‐ray photon may be split and one photon may produce two or more counts at adjacent pixels, both at lower energies than the incident energy. This “double‐counting” increases noise variance and degrades the spectral response. Overall, it has a significantly negative impact on the performance of PCD‐based computed tomography (CT). Charge sharing is induced by the detection physics and occurs regardless of count rates; thus, it is impossible to avoid. We propose in this paper a method that has a potential to address both noise and bias added by charge sharing.

Methods

We propose applying a multi‐energy inter‐pixel coincidence counter (MEICC) technique, which uses energy‐dependent coincidence counters, keeps the book of charge sharing events during data acquisition, and provides the exact number of charge sharing occurrences, which can be used to either correct or compensate for them after the acquisition is completed. MEICC does not interfere with the primary counting process; therefore, PCDs with MEICC will remain as fast as those without MEICC. MEICC can be implemented using current electronics technology because its inter‐pixel coincidence counters used to handle digital data are rather simple. We evaluated Cramér–Rao lower bound (CRLB) of PCDs with and without MEICC using a Monte Carlo simulation.

Results

When the number of energy windows was four or larger and eight neighboring pixels were used, the CRLBs of 225‐µm PCD with MEICC normalized by those of the current PCD with the same number of windows were 0.361–0.383 for water density images of two basis functions, which was only 5.7–16.4% worse than those of a PCD without charge sharing (which were at 0.329–0.358). In contrast, the normalized CRLBs of the PCD with one coincidence counter were 0.466–0.499, which were 37.3–45.6% worse than the PCD without charge sharing. The use of eight neighboring pixels provided ~10% better CRLB values than four neighboring pixels for MEICC. With four energy windows, decreasing the number of coincidence counters from 16 to 9 only slightly increased the CRLB from 0.255 to 0.269 (which corresponded to as little as a 5.5% change). The normalized CRLBs of MEICC for K‐edge imaging (gold) were 0.295–0.426, while those of the one coincidence counter were 0.926–0.959 and the ideal PCDs were 0.126–0.146.

Conclusions

The proposed MEICC provides spectral information that can be used to address charge sharing problems in PCDs and is expected to satisfy the requirements for clinical x‐ray CT. MEICC is very effective, especially for K‐edge imaging, which requires accurate spectral information.
A modified formalism for electron beam reference dosimetry to improve the accuracy of linac output calibration
Authors: Muir Bryan R.
Published: January 2020

Purpose

To present and demonstrate the accuracy of a modified formalism for electron beam reference dosimetry using updated Monte Carlo calculated beam quality conversion factors.

Methods

The proposed, simplified formalism allows the use of cylindrical ionization chambers in all electron beams (even those with low beam energies) and does not require a measured gradient correction factor. Data from a previous publication are used for beam quality conversion factors. The formalism is tested and compared to the present formalism in the AAPM TG‐51 protocol with measurements made in Elekta Precise electron beams with energies between 4 MeV and 22 MeV and with fields shaped with a 10 × 10 cm2 clinical applicator as well as a 20 × 20 cm2 clinical applicator for the 18 MeV and 22 MeV beams. A set of six ionization chambers are used for measurements (two cylindical reference‐class chambers, two scanning‐type chambers and two parallel‐plate chambers). Dose per monitor unit is derived using the data and formalism provided in the TG‐51 protocol and with the proposed formalism and data and compared to that obtained using ionization chambers calibrated directly against primary standards for absorbed dose in electron beams.

Results

The standard deviation of results using different chambers when TG‐51 is followed strictly is on the order of 0.4% when parallel‐plate chambers are cross‐calibrated against cylindrical chambers. However, if parallel‐plate chambers are directly calibrated in a cobalt‐60 beam, the difference between results for these chambers is up to 2.2%. Using the proposed formalism and either directly calibrated or cross‐calibrated parallel‐plate chambers gives a standard deviation using different chambers of 0.4%. The difference between results that use TG‐51 and the primary standard measurements are on the order of 0.6% with a maximum difference in the 4 MeV beam of 2.8%. Comparing the results obtained with the proposed formalism and the primary standard measurements are on the order of 0.4% with a maximum difference of 1.0% in the 4 MeV beam.

Conclusions

The proposed formalism and the use of updated data for beam quality conversion factors improves the consistency of results obtained with different chamber types and improves the accuracy of reference dosimetry measurements. Moreover, it is simpler than the present formalism and will be straightforward to implement clinically.
Apoptosis in porcine cumulus‐oocyte complexes: Relationship with their morphology and the developmental competence
Authors: Tello Maria F. , Lorenzo María S. , Luchetti Carolina G. , Maruri Alejandro , Cruzans Paula R. , Alvarez Gabriel M. , Gambarotta Mariana C. , Salamone Daniel F. , Cetica Pablo D. , Lombardo Daniel M.
Published: January 2020

The aim of this study was to assess the presence and distribution of apoptosis in porcine cumulus‐oocyte complexes (COCs) and its relations with COC morphology and developmental competence. The COCs were obtained from slaughterhouse ovaries, classified into A1 (top category), A2, B1, B2, C, and D based on their morphology. A1, A2, and B1 were matured and fertilized in vitro, and blastocyst rate was compared among them. Before and after in vitro maturation (IVM), annexin‐V staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed to assess early and late apoptosis, respectively. There was a significant increase in both annexin‐V (+) oocytes and TUNEL (+) cumulus cells as morphology further deteriorated. There were no statistical differences regarding annexin‐V (+) oocytes within immature and post‐IVM COCs, but TUNEL (+) oocytes were only observed in post‐IVM COCs. Early and late apoptosis was detected in cumulus cells of all categories of immature and post‐IVM COCs. However, the difference was only significant for annexin‐V (+). There were no significant differences in embryo development. Therefore, apoptosis increases as the morphological features of the immature COCs decrease. In conclusion, the selection of COCs from Categories A1, A2, and B1 may be used as a selection criterion for in vitro development.