bluuebunny/crossref_metadata_2025 huggingface dataset:
Oropharyngeal squamous cell carcinoma: radiomic machine-learning classifiers from multiparametric MR images for determination of HPV infection status
Authors: Suh Chong Hyun , Lee Kyung Hwa , Choi Young Jun , Chung Sae Rom , Baek Jung Hwan , Lee Jeong Hyun , Yun Jihye , Ham Sungwon , Kim Namkug
Published: October 2020

We investigated the ability of machine-learning classifiers on radiomics from pre-treatment multiparametric magnetic resonance imaging (MRI) to accurately predict human papillomavirus (HPV) status in patients with oropharyngeal squamous cell carcinoma (OPSCC). This retrospective study collected data of 60 patients (48 HPV-positive and 12 HPV-negative) with newly diagnosed histopathologically proved OPSCC, who underwent head and neck MRIs consisting of axial T1WI, T2WI, CE-T1WI, and apparent diffusion coefficient (ADC) maps from diffusion-weighted imaging (DWI). The median age was 59 years (the range being 35 to 85 years), and 83.3% of patients were male. The imaging data were randomised into a training set (32 HPV-positive and 8 HPV-negative OPSCC) and a test set (16 HPV-positive and 4 HPV-negative OPSCC) in each fold. 1618 quantitative features were extracted from manually delineated regions-of-interest of primary tumour and one definite lymph node in each sequence. After feature selection by using the least absolute shrinkage and selection operator (LASSO), three different machine-learning classifiers (logistic regression, random forest, and XG boost) were trained and compared in the setting of various combinations between four sequences. The highest diagnostic accuracies were achieved when using all sequences, and the difference was significant only when the combination did not include the ADC map. Using all sequences, logistic regression and the random forest classifier yielded higher accuracy compared with the that of the XG boost classifier, with mean area under curve (AUC) values of 0.77, 0.76, and 0.71, respectively. The machine-learning classifier of non-invasive and quantitative radiomics signature could guide the classification of the HPV status.
Clinical and functional analyses of AIPL1 variants reveal mechanisms of pathogenicity linked to different forms of retinal degeneration
Authors: Sacristan-Reviriego Almudena , Le Hoang Mai , Georgiou Michalis , Meunier Isabelle , Bocquet Beatrice , Roux Anne-Françoise , Prodromou Chrisostomos , Bainbridge James , Michaelides Michel , van der Spuy Jacqueline
Published: October 2020

Disease-causing sequence variants in the highly polymorphic AIPL1 gene are associated with a broad spectrum of inherited retinal diseases ranging from severe autosomal recessive Leber congenital amaurosis to later onset retinitis pigmentosa. AIPL1 is a photoreceptor-specific co-chaperone that interacts with HSP90 to facilitate the stable assembly of retinal cGMP phosphodiesterase, PDE6. In this report, we establish unequivocal correlations between patient clinical phenotypes and in vitro functional assays of uncharacterized AIPL1 variants. We confirm that missense and nonsense variants in the FKBP-like and tetratricopeptide repeat domains of AIPL1 lead to the loss of both HSP90 interaction and PDE6 activity, confirming these variants cause LCA. In contrast, we report the association of p.G122R with milder forms of retinal degeneration, and show that while p.G122R had no effect on HSP90 binding, the modulation of PDE6 cGMP levels was impaired. The clinical history of these patients together with our functional assays suggest that the p.G122R variant is a rare hypomorphic allele with a later disease onset, amenable to therapeutic intervention. Finally, we report the primate-specific proline-rich domain to be dispensable for both HSP90 interaction and PDE6 activity. We conclude that variants investigated in this domain do not cause disease, with the exception of p.A352_P355del associated with autosomal dominant cone-rod dystrophy.
Adsorption capability of brewed tea waste in waters containing toxic lead(II), cadmium (II), nickel (II), and zinc(II) heavy metal ions
Authors: Çelebi Hakan , Gök Gülden , Gök Oğuzhan
Published: October 2020

Recently, the search for low-cost eco-friendly adsorbents has become one of the main objectives of researchers. The aim of this study was to test the removal of four heavy metals, namely lead (Pb), zinc (Zn), nickel (Ni) and cadmium (Cd), from a simulated watery solution using brewed tea waste as a potentially suitable adsorbent. The effects of pH levels (2.0–6.0), adsorbent amount (0.1–5.0 g), contact times (1–150 min.) were examined throughout the adsorption process. The results of the experiments showed that the heavy metals elimination yields had an inverse relationship with pH and a linear relationship between the other parameters. The optimum pH for the removal of the heavy metals was between 4.0 and 5.0 in the case of the brewed tea waste. Equilibrium times of 2, 10, 30 and 5 min were required for the adsorption of Pb, Zn, Ni, Cd onto Camellia sinensis, respectively. Based on the results of this study it can be said that brewed tea waste has a high potential to remove heavy metals from aqueous solutions. The maximum adsorption capacities were calculated as 1.197, 1.457, 1.163 and 2.468 mg/g, for Pb, Zn, Ni and Cd, respectively, by fitting the equilibrium data to the Langmuir isotherm model.
A novel assay to measure calcification propensity: from laboratory to humans
Authors: Perez M. Mar , Ferrer Miguel D. , Lazo-Rodriguez Marta , Canals Ana Zeralda , Banon-Maneus Elisenda , Campistol Josep M. , Miller Stephan , Garg Rekha , Gold Alex , Salcedo Carolina , Perelló Joan
Published: October 2020

Cardiovascular calcification (CVC) contributes to morbidity and mortality in patients undergoing dialysis. We examined the pharmacodynamic effects of SNF472, a calcification inhibitor, on plasma calcium phosphate crystallization using spectrometric measurements, and its correlations with effects on CVC in rats or humans. Rats (N = 38) injected with vitamin D (days 1–3) to induce CVC were infused with saline or SNF472 (days 1–12). Inhibition of CVC was 50–65% with SNF472 3 mg/kg and ~ 80% with SNF472 10 or 30 mg/kg. SNF472 dose-dependently inhibited calcium phosphate crystallization, which correlated with inhibition of CVC (r = 0.628, P = 0.005). In patients with calciphylaxis (N = 14), infusion of SNF472 (~ 7 mg/kg) during hemodialysis for 12 weeks inhibited calcium phosphate crystallization by nearly 70%. In patients with CVC (N = 274), infusion of SNF472 during hemodialysis for 52 weeks inhibited calcium phosphate crystallization (placebo: 15%; 300 mg: 61%; 600 mg: 75%), which correlated with inhibition of CVC (r = 0.401, P = 0.003). These findings show a direct correlation between inhibition of calcium phosphate crystallization in plasma and inhibition of CVC both in a rat model and in humans, supporting the use of the pharmacodynamic assay in clinical trials as a potentially predictive tool to evaluate the activity of calcification inhibitors.
Ultra-strong stability of double-sided fluorinated monolayer graphene and its electrical property characterization
Authors: Wang Haidong , Narasaki Masahiro , Zhang Zhongwei , Takahashi Koji , Chen Jie , Zhang Xing
Published: October 2020

Fluorinated graphene has a tunable band gap that is useful in making flexible graphene electronics. But the carbon–fluorine (C–F) bonds in fluorinated graphene can be easily broken by increased temperature or electron beam irradiation. Here, we demonstrate that the stability of fluorinated graphene is mainly determined by its C–F configuration. The double-sided fluorinated graphene has a much stronger stability than the single-sided fluorinated graphene under the same irradiation dose. Density functional theory calculations show that the configuration of double-sided fluorinated graphene has a negative and low formation energy, indicating to be an energetically stable structure. On the contrary, the formation energy of single-sided fluorinated graphene is positive, leading to an unstable C–F bonding that is easily broken by the irradiation. Our findings make a new step towards a more stable and efficient design of graphene electronic devices.
Pathogenesis of CDK8-associated disorder: two patients with novel CDK8 variants and in vitro and in vivo functional analyses of the variants
Authors: Uehara Tomoko , Abe Kota , Oginuma Masayuki , Ishitani Shizuka , Yoshihashi Hiroshi , Okamoto Nobuhiko , Takenouchi Toshiki , Kosaki Kenjiro , Ishitani Tohru
Published: October 2020

Cyclin-dependent kinase 8 (CDK8) is a member of the CDK/Cyclin module of the mediator complex. A recent study reported that heterozygous missense CDK8 mutations cause a neurodevelopmental disorder in humans. The mechanistic basis of CDK8-related disorder has yet to be delineated. Here, we report 2 patients with de novo missense mutations within the kinase domain of CDK8 along with the results of in vitro and in vivo functional analyses using a zebrafish model. Patient 1 and Patient 2 had intellectual disabilities and congenital anomalies. Exome analyses showed that patient 1 had a heterozygous de novo missense p.G28A variant in the CDK8 (NM_001260.3) gene and patient 2 had a heterozygous de novo missense p.N156S variant in the CDK8 gene. We assessed the pathogenicity of these two variants using cultured-cells and zebrafish model. An in vitro kinase assay of human CDK8 showed that enzymes with a p.G28A or p.N156S substitution showed decreased kinase activity. An in vivo assays of zebrafish overexpression analyses also showed that the p.G28A and p.N156S alleles were hypomorphic alleles. Importantly, the inhibition of CDK8 kinase activity in zebrafish embryos using a specific chemical inhibitor induced craniofacial and heart defects similar to the patients’ phenotype. Taken together, zebrafish studies showed that non-synonymous variants in the kinase domain of CDK8 act as hypomorphic alleles causing human congenital disorder.
Deep learning algorithms for detecting and visualising intussusception on plain abdominal radiography in children: a retrospective multicenter study
Authors: Kwon Gitaek , Ryu Jongbin , Oh Jaehoon , Lim Jongwoo , Kang Bo-kyeong , Ahn Chiwon , Bae Junwon , Lee Dong Keon
Published: October 2020

This study aimed to verify a deep convolutional neural network (CNN) algorithm to detect intussusception in children using a human-annotated data set of plain abdominal X-rays from affected children. From January 2005 to August 2019, 1449 images were collected from plain abdominal X-rays of patients ≤ 6 years old who were diagnosed with intussusception while 9935 images were collected from patients without intussusception from three tertiary academic hospitals (A, B, and C data sets). Single Shot MultiBox Detector and ResNet were used for abdominal detection and intussusception classification, respectively. The diagnostic performance of the algorithm was analysed using internal and external validation tests. The internal test values after training with two hospital data sets were 0.946 to 0.971 for the area under the receiver operating characteristic curve (AUC), 0.927 to 0.952 for the highest accuracy, and 0.764 to 0.848 for the highest Youden index. The values from external test using the remaining data set were all lower (P-value < 0.001). The mean values of the internal test with all data sets were 0.935 and 0.743 for the AUC and Youden Index, respectively. Detection of intussusception by deep CNN and plain abdominal X-rays could aid in screening for intussusception in children.
Distinct expression profiles of peptides in placentae from preeclampsia and normal pregnancies
Authors: Huang Jin , Ling Zhonghui , Zhong Hong , Yin Yadong , Qian Yating , Gao Mingming , Ding Hongjuan , Cheng Qing , Jia Ruizhe
Published: October 2020

This study sought to identify potential bioactive peptides from the placenta that are involved in preeclampsia (PE) to obtain information about the prediction, diagnosis and treatment of PE. The liquid chromatography/mass spectrometry was used to perform a comparative analysis of placental peptides in normal and PE pregnancies. Gene ontology (GO), pathway analysis and ingenuity pathway analysis (IPA) were used to evaluate the underlying biological function of the differential peptides based on their protein precursors. Transwell assays and qPCR were used to study the effect of the identified bioactive peptides on the function of HTR-8/SVneo cells. A total of 392 upregulated peptides and 420 downregulated peptides were identified (absolute fold change ≥ 2 and adjusted P value < 0.05). The GO analysis, pathway analysis, and IPA revealed that these differentially expressed peptides play a role in PE. In addition, the up-regulated peptide “DQSATALHFLGRVANPLSTA” derived from Angiotensinogen exhibited effect on the invasiveness of HTR-8/SVneo cells. The current preliminary research not only provides a new research direction for studying the pathogenesis of PE, but also brings new insights for the prediction, diagnosis and treatment of PE.
Distinct response of gross primary productivity in five terrestrial biomes to precipitation variability
Authors: Ritter François , Berkelhammer Max , Garcia Cynthia
Published: October 2020

Climate change will impact precipitation variability, potentially accelerating climate-terrestrial carbon feedbacks. However, the response of ecosystems to precipitation variability is difficult to constrain due to myriad physiological and abiotic variables that limit terrestrial productivity. Based on a combination of satellite imagery and a global network of daily precipitation data, we present here a statistical framework to isolate the impact of precipitation variability on the gross primary productivity of five biomes that collectively account for 50% of global land area. The productivity of mesic grasslands and forests decreases by ~28% and ~7% (respectively) in response to more irregular rain within the year, while the sensitivity is halved in response to higher year-to-year variability. Xeric grasslands are similarly impacted by intra-annual rainfall variance, but they show an increase in productivity with higher interannual rainfall variability. Conversely, the productivity of boreal forests increases under higher variability on both timescales. We conclude that projected changes in precipitation variability will have a measurable global impact on the terrestrial carbon sink.
Unfolding multi-stranded perylene bisimide LC columns – a mesogen design for efficient nanoscale multilayer self-assembly
Authors: Lehmann Matthias , Hecht Markus , Herbst Stefanie , Cui Kang , Würthner Frank
Published: October 2020

A completely nanosegregated multilayer liquid crystal phase is found for a mesogen tethered perylene bisimide – a design which opens the way to new complex multifunctional materials.
Enhanced tetrabromobisphenol A debromination by nanoscale zero valent iron particles sulfidated with S0 dissolved in ethanol
Authors: Wang Heli , Zhong Yin , Zhu Xifen , Li Dan , Deng Yirong , Huang Weilin , Peng Ping'an
Published: October 2020

Modification of nanoscale zero-valent iron (nZVI) with reducing sulfur compounds has proven to improve the reactivity of nZVI towards recalcitrant halogenated organic contaminants.
Jackfruit (Artocarpus heterophyllus Lam.) oligopeptides regulate immune responses via Th cell stimulation, cytokine secretion and antibody production
Authors: Hao Yun-tao , Liu Xin-ran , Zhu Na , Mao Rui-xue , Liu Rui , Wu Lan , Kang Jia-wei , Hu Jia-ni , Li Yong
Published: October 2020

This study aimed to observe the immunomodulatory effects of oligopeptides derived from jackfruit (Artocarpus heterophyllus Lam.) (JOPs).
Anticancer potential of an exopolysaccharide from Lactobacillus helveticus MB2-1 on human colon cancer HT-29 cells via apoptosis induction
Authors: Xiao Luyao , Ge Xiaojia , Yang Lin , Chen Xiaohong , Xu Qian , Rui Xin , Fan Xia , Feng Li , Zhang Qiuqin , Dong Mingsheng , Li Wei
Published: October 2020

LHEPS-1 exhibited the strongest anti-proliferation effect, prevented G1 to S transition and increased the apoptosis of human colon cancer HT-29 cells.
Metallophthalocyanines in a ternary photoactive layer (P3HT:MPc:PC70BM) for bulk heterojunction solar cells
Authors: Gounden Denisha , Pillay Michael N. , Raab Timo , Nombona Nolwazi , Schmidt-Mende Lukas , van Zyl Werner E.
Published: October 2020

Novel bulk heterojunction organic photovoltaic solar cells have been fabricated by introducing a series of metallophthalocyanines into a photoactive blend of a poly(3-hexylthiophene-2,5-diyl) and [6,6]-phenyl C70 butyric acid methyl ester.
Structure–activity relationship studies on 2,5,6-trisubstituted benzimidazoles targeting Mtb-FtsZ as antitubercular agents
Authors: Haranahalli Krupanandan , Tong Simon , Kim Saerom , Awwa Monaf , Chen Lei , Knudson Susan E. , Slayden Richard A. , Singleton Eric , Russo Riccardo , Connell Nancy , Ojima Iwao
Published: October 2020

Filamenting temperature sensitive protein Z (FtsZ) is an essential bacterial cell division protein and a promising target for the development of new antibacterial therapeutics.
Evaluating the chemical exfoliation of lithium cobalt oxide using UV-Vis spectroscopy
Authors: Pachuta Kevin , Pentzer Emily , Sehirlioglu Alp
Published: October 2020

The exfoliation yield of protonated lithium cobalt oxide was quantified with ultraviolet-vis spectroscopy. An in-depth analysis using this method confirmed and discovered many key aspects of its soft-chemical exfoliation.
In situ fabrication of MS@MnO2 hybrid as nanozymes for enhancing ROS-mediated breast cancer therapy
Authors: Zhu Xufeng , Liu Yanan , Yuan Guanglong , Guo Xian , Cen Jieqiong , Gong Youcong , Liu Jie , Gang Ye
Published: October 2020

The reactive oxygen species (ROS)-mediated anti-cancer therapy that shows the advantages of tumor specificity, high curative effect, and less toxic side-effects has powerful potential for cancer treatment.
Atom transfer between precision nanoclusters and polydispersed nanoparticles: a facile route for monodisperse alloy nanoparticles and their superstructures
Authors: Bose Paulami , Chakraborty Papri , Mohanty Jyoti Sarita , Nonappa  , Ray Chowdhuri Angshuman , Khatun Esma , Ahuja Tripti , Mahendranath Ananthu , Pradeep Thalappil
Published: October 2020

A unique method to prepare well-defined highly monodisperse gold–silver alloy nanoparticles through a chemical reaction of gold nanoclusters and polydispersed silver nanoparticles.
Solvent-driven chirality for luminescent self-assembled structures: experiments and theory
Authors: Lochenie Charles , Insuasty Alberto , Battisti Tommaso , Pesce Luca , Gardin Andrea , Perego Claudio , Dentinger Mike , Wang Di , Pavan Giovanni M. , Aliprandi Alessandro , De Cola Luisa
Published: October 2020

Visualizing the interconversion from chiral helices to ribbons like-structures of self-assembled luminescent platinum complexes.
Nanopore sensing of single-biomolecules: a new procedure to identify protein sequence motifs from molecular dynamics
Authors: Nicolaï Adrien , Rath Aniket , Delarue Patrice , Senet Patrick
Published: October 2020

MoS2 nanopores have emerged as one of the most promising solid-state nanopores for protein sequence motifs detection.
Boosting or moderating surface-initiated Cu(0)-mediated controlled radical polymerization with external additives
Authors: Li Wei , Sheng Wenbo , Jordan Rainer , Zhang Tao
Published: October 2020

External additives regulate the copper disproportionation/comproportionation equilibrium to control polymer brush growth in surface-initiated Cu(0)-mediated controlled radical polymerization.
Polymerization-induced self-assembly via RAFT in emulsion: effect of Z-group on the nucleation step
Authors: Guimarães Thiago R. , Bong Y. Loong , Thompson Steven W. , Moad Graeme , Perrier Sébastien , Zetterlund Per B.
Published: October 2020

It is demonstrated that the nature of the Z-group of trithiocarbonate RAFT agents can have a major effect on the nucleation step of aqueous RAFT PISA performed as emulsion polymerization.
Temperature-sensing luminescent materials La9.67Si6O26.5:Yb3+–Er3+/Ho3+ based on pump-power-dependent upconversion luminescence
Authors: Zhang Jia , Chen Jiajun , Zhang Yining
Published: October 2020

Rare earth ion doped upconversion (UC) luminescent materials could show potential applications in optical temperature sensing.
Magnetic thermally sensitive interpenetrating polymer network (IPN) nanogels: IPN-pNIPAm@Fe2O3-SiO2
Authors: Teng Yun , Pong Philip W. T.
Published: October 2020

In this paper, iron oxide-silica@poly(acrylamide-co-N,N-diethylacrylamide)/poly(N,N-diethylacrylamide) interpenetrating polymer network (IPN-pNIPAm@Fe2O3-SiO2) nanogels, possessing both magnetic and thermo-sensitive properties were successfully prepared.
Fully inkjet-printed multilayered graphene-based flexible electrodes for repeatable electrochemical response
Authors: Pandhi Twinkle , Cornwell Casey , Fujimoto Kiyo , Barnes Pete , Cox Jasmine , Xiong Hui , Davis Paul H. , Subbaraman Harish , Koehne Jessica E. , Estrada David
Published: October 2020

A fully inkjet printed and flexible multilayer graphene based three electrode device showed electrochemical reversibility.
Facile construction of a ZIF-67/AgCl/Ag heterojunction via chemical etching and surface ion exchange strategy for enhanced visible light driven photocatalysis
Authors: Shao Wei , Chen Yan-Ru , Xie Feng , Zhang Hao , Wang Hai-Tao , Chang Na
Published: October 2020

It is of great importance to design and fabricate heterojunction photocatalysts to improve photocatalytic performance.
Development of an efficient CVD technique to prepare TiO2/porous–carbon nanocomposites for high rate lithium-ion capacitors
Authors: Iwamura Shinichiroh , Motohashi Shota , Mukai Shin R.
Published: October 2020

TiO2 nanoparticles with a diameter of around 5 nm were homogeneously deposited inside the pores of meso-macroporous carbons.
Access to substituted cyclobutenes by tandem [3,3]-sigmatropic rearrangement/[2 + 2] cycloaddition of dipropargylphosphonates under Ag/Co relay catalysis
Authors: Ni Qijian , Song Xiaoxiao , Png Chin Wen , Zhang Yongliang , Zhao Yu
Published: October 2020

In situ generation of allenes through [3,3]-sigmatropic rearrangement of propargylphosphonates. Divergent allene–allene or allene–alkyne cycloaddition by Ag/Co relay catalysis. Products as promising suppressors of cellular proliferation.
Clinical Intersections Among Idiopathic Language Disorder, Social (Pragmatic) Communication Disorder, and Attention-Deficit/Hyperactivity Disorder
Authors: Redmond Sean M.
Published: October 2020

Purpose

Estimates of the expected co-occurrence rates of idiopathic language disorder and attention-deficit/hyperactivity disorder (ADHD) provide a confusing and inconsistent picture. Potential sources for discrepancies considered so far include measurement and ascertainment biases (
Redmond, 2016a
,
2016b
). In this research symposium forum article, the potential impact of applying different criteria to the observed co-occurrence rate is examined through an appraisal of the literature and an empirical demonstration.

Method

Eighty-five cases were selected from the
Redmond, Ash, et al. (2019)
study sample. Standard scores from clinical measures collected on K–3rd grade students were used to assign language impairment status, nonverbal impairment status, social (pragmatic) communication disorder status, and ADHD status. Criteria extrapolated from the specific language impairment (
Stark & Tallal, 1981
), developmental language disorder (
Bishop et al., 2017
), and
Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition
language disorder (
American Psychiatric Association, 2013
) designations were applied.

Results

The
Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition
language disorder designation and its separation of language disorder from the social (pragmatic) communication disorder designation provided the clearest segregation of idiopathic language deficits from elevated ADHD symptoms, showing only a 2% co-occurrence rate. In contrast, applying the broader developmental language disorder designation raised the observed co-occurrence rate to 22.3%. The specific language impairment designation yielded an intermediate value of 16.9%.

Conclusions

Co-occurrence rates varied as a function of designation adopted. The presence of pragmatic symptoms exerted a stronger influence on observed co-occurrence rates than low nonverbal abilities. Impacts on clinical management and research priorities are discussed.

Presentation Video

https://doi.org/10.23641/asha.13063751
Advances in Specific Language Impairment Research and Intervention: An Overview of Five Research Symposium Papers
Authors: Rice Mabel L.
Published: October 2020

Purpose

This article provides an overview of five papers appearing together on the topic of “Advances in Specific Language Impairment Research and Intervention,” which was the 2019 program in an ongoing series of research symposia presented at the Annual Convention of the American Speech-Language-Hearing Association.

Method

The article provides a historical context for the set of papers, then a short summation of each paper's content, followed by the identification of overarching themes and working conclusions.

Results

Each paper provides summations of empirical results, and some papers provide new empirical evidence.

Conclusion

The papers collectively highlight six points: (a) Children with specific language impairment (SLI) are likely to be unidentified among their age peers. (b) There is great need for better identification of children with SLI across developmental levels. (c) Progress is evident toward a better understanding of causal pathways, as examined across different research designs involving comparison of children with typical language acquisition to children with SLI and other possibly co-occurring atypical conditions. (d) Measuring multiple dimensions of language brings enhanced informativeness, with differing outcomes for differing dimensions. (e) Replicated research findings require precision of methods in order to reduce unexplained error variance especially when defining groups. (f) Accurate identification of children with SLI is the first step toward a sound treatment plan for SLI and reading disorders as well.

Presentation Video

https://doi.org/10.23641/asha.13063721
Synthesis of articular cartilage‐inspired branched polyelectrolyte polymer for enhanced lubrication
Authors: Wang Yixin , Wan Li , Sun Yulong , Zhang Hongyu
Published: October 2020

The superlubrication property of articular cartilage is attributed to the hydration lubrication mechanism. This involves the complexation of biomacromolecules with phosphatidylcholine lipids to form a lubricating boundary layer on the surface. Based on this mechanism, a branched polyelectrolyte polymer – PEI‐PMPC was synthesised in this study to enhance lubrication via tert‐butyl hydroperoxide‐initiated grafting polymerisation of 2‐methacryloyloxyethyl phosphorylcholine (MPC) onto polyethyleneimine (PEI) with various molecular weights. Following the characterisation of the polymer using nuclear magnetic resonance, a series of tribological tests were performed under different normal loads and different scan rates. The results showed that the PEI‐PMPC polyelectrolyte polymer in aqueous solution could effectively reduce the friction coefficient and wear generation between the polyethylene ball and the silica wafer. Additionally, an improvement in the lubrication performance was detected for the PEI‐PMPC polyelectrolyte polymer when high molecular weight PEI was used during the reaction, which was attributed to the formation of the hydration shells surrounding the zwitterionic charges of PMPC and the viscosity of the polymer. In conclusion, the PEI‐PMPC polyelectrolyte polymer developed herein was characterised by enhanced lubrication, and may be potentially used for biomedical applications such as intra‐articular injection to restore joint lubrication.
Robust H∞ filtering for 2D systems with RON under the stochastic communication protocol
Authors: Li Dehao , Liang Jinling , Wang Fan
Published: October 2020

This study is concerned with the robust filtering problem for two‐dimensional (2D) systems in Roesser model with randomly occurring non‐linearity (RON) and stochastic communication protocol (SCP). The introduced non‐linearity is sector‐like and governed by a random variable obeying the Bernoulli distribution law. The SCP is depicted by an independent and identically distributed sequence to schedule the signal transmission. The phenomenon of time delay is also taken into consideration. The aim of this study is to design a filter such that the augmented filtering error system satisfies a predefined performance index. Sufficient condition is first given to ensure the robust stability of the augmented filtering error system via Lyapunov theory and stochastic analysis. Then, the result is extended to guarantee the performance of the augmented system under SCP, where sufficient criterion related to the transmission probability is given in terms of matrix inequality. Moreover, the filter gains are explicitly designed which enable the system to achieve the filtering performance. Finally, a numerical example is given to show the effectiveness of the proposed design method.
Millimetre‐wave design and verification of a meta‐surface dielectric window made of polytetrafluoroethylene in Ka‐ and Q‐band
Authors: Wang Yu , Liu Guo , Wang Weijie , Fang Chao , Wu Zewei , Luo Yong
Published: October 2020

A periodic dielectric meta‐surface structure was designed to extend the output window operating bandwidth of a wideband mode gyrotron travelling wave tube. The equivalent permittivity of the meta‐surface matching layer can be adjusted arbitrarily by changing the lattice dimensions. The fabricated meta‐surface dielectric window demonstrated a relative bandwidth of 53.9% with a reflection below in the Ka‐ and Q‐band.
Neglected X-ray discovered polars
Authors: Beuermann K. , Burwitz V. , Reinsch K. , Schwope A. , Thomas H.-C.
Published: October 2020

We report results on the ROSAT-discovered noneclipsing short-period polars RX J0154.0−5947, RX J0600.5−2709, RX J0859.1+0537, RX J0953.1+1458, and RX J1002.2−1925 collected over 30 years. We present accurate linear orbital ephemerides that allow a correct phasing of data taken decades apart. Three of the systems show cyclotron and Zeeman lines that yield magnetic field strengths of 36 MG, 19 MG, and 33 MG for the last three targets, respectively. RX J0154.0−5947, RX J0859.1+0537, and RX J1002.2−1925 show evidence for part-time accretion at both magnetic poles, while RX J0953.1+1458 is a polar with a stable one-pole geometry. RX J1002.2−1925 shows large variations in the shapes of its light curves that we associate with an unstable accretion geometry. Nevertheless, it appears to be synchronized. We determined the bolometric soft and hard X-ray fluxes and the luminosities at theGaiadistances of the five stars. Combined with estimates of the cyclotron luminosities, we derived high-state accretion rates that range fromṀ= 2.9 × 10−11 M⊙yr−1to 9.7 × 10−11 M⊙yr−1for white dwarf masses between 0.61 and 0.82M⊙, in agreement with predictions based on the observed effective temperatures of white dwarfs in polars and the theory of compressional heating. Our analysis lends support to the hypothesis that different mean accretion rates appply for the subgroups of short-period polars and nonmagnetic cataclysmic variables.
Link between radio-loud AGNs and host-galaxy shape
Authors: Zheng X. C. , Röttgering H. J. A. , Best P. N. , van der Wel A. , Hardcastle M. J. , Williams W. L. , Bonato M. , Prandoni I. , Smith D. J. B. , Leslie S. K.
Published: October 2020

The morphology of quiescent galaxies has been found to be correlated with the activity of their central super massive black hole. In this work, we use data from the first data release of the LOFAR Two-Metre Sky Survey (LoTSS DR1) and the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) to select more than 15 000 quiescent galaxies at z <  0.3 to investigate the connection between radio-loud active galactic nuclei (RLAGNs) and the morphology of their host galaxy. Taking advantage of the depth of LoTSS, we find that the fraction of RLAGNs with L150 MHz > 1021 W Hz−1 at fixed stellar mass, velocity dispersion, or surface mass density does not depend on the galaxy projected axis ratio (q). However, the high-power (L150 MHz > 1023 W Hz−1) RLAGNs are more likely to be found in massive, round galaxies, while the low- and intermediate-power (L150 MHz ≤ 1023 W Hz−1) RLAGNs have similar distributions of q to non-RLAGN galaxies. We argue that our results support the picture that high-power RLAGNs are more easily triggered in galaxies with a merger-rich history, while low-power RLAGNs can be triggered in galaxies growing mainly via secular processes. Our work also supports the idea that the low-luminosity RLAGN may be sufficient for maintenance-mode feedback in low-mass quiescent galaxies with disc-like morphology, which is based on a simple extrapolation from the observed energy balance between cooling and RLAGN-induced cavities in massive clusters. We find no significant difference between the q distributions of RLAGNs likely to be found in clusters and those likely not found in clusters after controlling the radio luminosity and stellar mass of the two samples, indicating that the environment does not significantly influence the morphology–RLAGN correlation.
TERRE project: interplay between unsaturated soil mechanics and low-carbon geotechnical engineering
Authors: Tarantino Alessandro , El Mountassir Grainne , Wheeler Simon , Gallipoli Domenico , Russo Giacomo , Augarde Charles , Urciuoli Gianfranco , Pirone Marianna , Stokes Alexia , van de Kuilen Jan Willem , Gard Wolfgang , Fourcaud Thierry , Romero Enrique , Priegue Angel , Smith Colin C , Larrey-Lassalle Pyrène , Becker Patrick , Ferrari Alessio , Dainese Roberta , Salifu Emmanuel , Beber Raniero , Scarfone Riccardo , Cuccurullo Alessia , Coudert Elodie , Dias Sofia , Mmuguda-Viswanath Sravan , Rossi Lorenzo MW , Kamath Abhijith , Fraccica Alessandro , Karagianni Pavlina , González Castejón Javier , Ouakka Slimane , Zannin Jacopo , Speranza Gianluca
Published: October 2020

The geotechnical construction industry is a major component of the overall construction sector and is strategically important in infrastructure development (transportation, flood and landslide protection, building foundations, waste disposal). Although industry and research in the overall construction sector have been investing significantly in recent years to produce innovative low-carbon technologies, little innovation has been created in geotechnical construction industry, which is lagging behind other construction industry sectors. This paper discusses the interplay between low-carbon geotechnical engineering and unsaturated soil mechanics based on the research carried out within the project TERRE (Marie Skłodowska-Curie Innovative Training Networks funded by the European Commission, 2015-2019,H2020-MSCA-ITN-2015-675762).
Probabilistic analysis of flood embankment stability: the case study of the Adige River embankment in Italy
Authors: Amabile Alessia , De Polo Fabio , Tarantino Alessandro
Published: October 2020

Flooding is a worldwide phenomenon. Over the last few decades the world has experienced a rising number of devastating flood events and the trend in such natural disasters is increasing. Furthermore, escalations in both the probability and magnitude of flood hazards are expected as a result of climate change. Flood defence embankments are one of the major flood defence measures and stability assessment for these structures is therefore a very important process. Traditional deterministic approaches to stability analysis do not allow taking into account and quantifying the uncertainties in soil characterisation. For this reason they may not be sufficient to capture the failure of flood embankments. The paper presents a probabilistic approach for the stability analysis of flood embankments taking into account the probabilistic distribution of soil hydro-mechanical properties. The approach is validated against the failure case study of the Adige river embankment in Italy, by comparing the probability of failure of two sections, within and outside the failure segment respectively.
Analysis of massive sulphate attack to cement-treated compacted soils
Authors: Ramon-Tarragona Anna , Alonso Eduardo
Published: October 2020

The paper describes the heave experienced by two embankments providing access to a bridge located in a high-speed railway line. The compacted soil, a mixture of a low plasticity clay, sand and gravel, had a significant sulphate content (2 – 2.5%). The embankments received a reinforcing treatment by mixing the soil with cement in the proximity of the bridge abutments. In addition, a grid of grouting columns provided more stiffness to the embankments. The embankments experienced a fast heaving rate (around 4 mm/month) in the areas improved by cement mixing. Precision extensometers indicated that heave concentrated in the upper 6 – 8 m of the embankments. The sulphate content reduced sharply to 0.25% at increasing depth. No heave was detected in these deeper zones. The swelling was found to be associated with the development of thaumasite and ettringite minerals. The presence of clay, cement and sulphates in the compacted soils and the infiltration of water from rainfall events are ideal conditions for the growth of the mentioned minerals. Long-term tests performed on compacted samples provided a good evidence of the phenomena developing in situ. A chemical modelling of the mineral changes at the soil-cement interface provided an additional insight into the development of swelling, which could last for a long time (several years). Accordingly, it was decided to underpin the railway track and to excavate the upper active volume of the embankments. This solution went in parallel with train service, which was never interrupted.
Water retention and characteristic curves representing tropical clay soils from Africa
Authors: Alhaj K.M.A. , Biscontin G. , Elshafie M.Z.E.B , Osman A.S.
Published: October 2020

Soil water retention curves (SWRCs) form an essential component of frameworks coupling the hydromechanical behaviour of unsaturated soils. The curves describe how suction changes with variables such as degree of saturation, void ratio and volumetric/gravimetric water content. SWRCs can be determined from incrementally drying initially saturated reconstituted samples to a final residual state, thus developing the primary drying curve (PDC). The primary wetting curve (PWC) is established from subsequent incremental wetting from residual state and is hysteretic compared with the PDC. SWRCs for reconstituted, high-plasticity, tropical clays from Africa (Sudan, Tanzania and South Africa) will be produced using suction measuring instruments, a tensiometer, filter paper and a dew point potentiometer. The development of SWRCs under various subsequent cycles of drying will be presented and discussed along with details concerning volumetric changes and cracking during drying. In order to investigate the uniqueness of the PDC and PWC and the effect of initial void ratio, SWRCs will be determined for samples formed by reconstituted from slurry under different applied energy levels.
Subsidence of dredged organic sediments in cultivated peatlands
Authors: van Paassen Leon A. , Oliveira Bruna R.F. , Zain Nor H.M. , Jommi Cristina
Published: October 2020

Many low-lying peatlands in delta areas undergo significant subsidence due to drainage for agricultural purposes. Subsidence may be attributed to shrinkage, consolidation or oxidation. At the same time the canals and ditches are regularly dredged to maintain water quality and drainage capacity. Often these dredged sediments are placed on land, which may help to slow down subsidence. In this study subsidence of organic sediments was monitored for a period of three years. The sediments were dredged from lakes and canals in the peatlands of Wormer- en Jisperveld, in the Netherlands and placed in an on-land constructed depot. Samples were collected at regular time intervals to measure water content and organic content. Additionally, laboratory tests were performed to characterize the organic sediments and determine the compression, consolidation, shrinkage and water retention characteristics under various oxidizing conditions. The laboratory tests showed that oxidation can significantly affect the compression, consolidation, water retention and shrinkage characteristics of organic soils. However, monitoring results in the field showed that the major part of the subsidence, which occurred within the three years of this study, could be attributed to shrinkage of the dredged sediments and the remainder to consolidation of the underlying peat layers, while the organic matter content did not change significantly.
Physical modelling of piles under lateral loading in unsaturated soils
Authors: Lalicata Leonardo Maria , Rotisciani Giada Maria , Desideri Augusto , Casini Francesca , Thorel Luc
Published: October 2020

In this paper, selected aspects of an experimental study conducted in a geotechnical centrifuge are discussed. The tests aimed to explore the effects of partial saturation of soil on the response of a single pile subjected to a combination of lateral force and bending moment under drained conditions. The soil used in the experiments is a low plasticity silty soil, named B-grade kaolin, characterized by a relatively high permeability compared to the typical values for clayey soils. Two different elevations of the water table and its effects on the pile response under loading are studied. The data show a marked influence of soil partial saturation on the pile response, both under working loads and ultimate loads. In particular, under working loads, the displacement of the head of the pile is appreciably lower than that measured under saturated conditions.
A single-stress model for the prediction of yielding of unsaturated cemented soils under isotropic loads
Authors: Bruno Agostino Walter , Gallipoli Domenico , Rouainia Mohamed , Lloret-Cabot Marti
Published: October 2020

This paper presents a bounding surface model predicting the combined effects of cementation and partial saturation on the mechanical behaviour of soils subjected to isotropic loading. The loss of cementation caused by loading, wetting or drying of a normally consolidated soil is described by a “cementation bonding function”. This states that, under virgin conditions, the ratio between cemented and uncemented void ratios monotonically decreases with increasing levels of scaled stress. The scaled stress is the variable governing the intrinsic behaviour of the soil under both saturated and unsaturated conditions. Combination of the cementation bounding function with a previously proposed model for unsaturated soil behaviour leads to the formulation of a “cemented unified normal compression line” (CUNCL). This describes the virgin behaviour of both cemented and uncemented soils under saturated and unsaturated conditions. Progressive yielding is modelled by assuming that the slope of the generic loading curve tends towards the slope of the CUNCL as the soil state moves from overconsolidated to virgin conditions. The model has been calibrated and validated against existing experimental data demonstrating a good ability to predict the void ratio of cemented soils during isotropic loading, unloading and wetting under both saturated and unsaturated conditions.
Numerical modelling of the response of an unsaturated silty soil under wetting and gravitational loading processes
Authors: Rotisciani Giada M. , Lalicata Leonardo M. , Desideri Augusto , Casini Francesca
Published: October 2020

This paper presents the results of a numerical study aiming at simulating the response of an unsaturated fine-grained soil under wetting and gravitational loading processes. This study is based on the results of some centrifuge tests carried out to assess the influence of partial saturation on the laterally loaded pile response. The hydro-mechanical behaviour of the silty soil is described using a constitutive model adapted to unsaturated conditions. The model predictions are compared with the measurements provided by LVDTs and laser transducers in the first phases of the experimental study. Besides validating the model, the numerical study aimed at investigating the influence of the after-compaction conditions on both the displacement field and the evolution of the more significant state variables during imbibition and gravitational loading processes. Finally, an additional analysis is conducted to determine the effects of the pile installation on the soil response.
A deformation-dependent soil-water characteristic surface model considering hysteresis
Authors: Guoqing Cai , Tianchi Wu , Hao Li , Chenggang Zhao , Jingjing Tian , Jian Li
Published: October 2020

The soil-water characteristic surface model plays an essential part in predicting the hydraulic behaviour of unsaturated soils. Based on the theory of plasticity bounding surface, this paper presents a three-dimensional soil-water characteristic surface model considering the effects of deformation and hysteresis. Suction and void ratio are adopted as independent variables, while the degree of saturation is adopted as a dependent variable. A new mapping rule is used where the distance between the current position and its image point can be calculated as a difference in the degree of saturation axis. The model is verified by comparing with drying-wetting tests on bentonite/kaolin mix and pearl clay. The efficiency of the proposed model is proven by validation tests.
The mechanical behavior of an expansive soil due to long-term seasonal rainfalls
Authors: LI Kai , Kong Liang , Nowamooz Hossein , Chazallon Cyrille
Published: October 2020

Expansive soils, susceptible to be affected by the environmental conditions, expand when water is added and shrink when they dry out. This continuous change in soil volume is able to cause structures built on them to move unevenly and crack. To investigate the hydro-mechanical behavior of unsaturated expansive soils, many laboratory tests on these materials have been carried on and numerous models have also been proposed with a relatively large number of parameters. In this study, a simplified model based on Zarka method has been developed for unsaturated expansive soils. The direct determination of the steady solutions in Zarka analysis is able to replace classic step-by-step method and needs less model parameters. In this context, this paper presents a Zarka-based model to predict the volume change in unsaturated expansive soils under seasonal drought and rainfall cycles and the proposed model is implemented in the finite element code to simulate long-term behavior of a 2D structure consisting of expansive soils and subjected to successive drought and rainfall cycles. Finally, the numerical calculation defines the plastic strain field and the inelastic displacement field of the studied structure.