bluuebunny/crossref_metadata_2025 huggingface dataset:
Baseline Splenic Volume as a Prognostic Biomarker of FOLFIRI Efficacy and a Surrogate Marker of MDSC Accumulation in Metastatic Colorectal Carcinoma
Authors: Niogret Julie , Limagne Emeric , Thibaudin Marion , Blanc Julie , Bertaut Aurelie , Le Malicot Karine , Rinaldi Yves , Caroli-Bosc François-Xavier , Audemar Franck , Nguyen Suzanne , Sarda Corinne , Lombard-Bohas Catherine , Locher Christophe , Carreiro Miguel , Legoux Jean-Louis , Etienne Pierre-Luc , Baconnier Mathieu , Porneuf Marc , Aparicio Thomas , Ghiringhelli Francois
Published: June 2020

Background: Predictive biomarkers of response to chemotherapy plus antiangiogenic for metastatic colorectal cancer (mCRC) are lacking. The objective of this study was to test the prognostic role of splenomegaly on baseline CT scan. Methods: This study is a sub-study of PRODIGE-9 study, which included 488 mCRC patients treated by 5-fluorouracil, leucovorin and irinotecan (FOLFIRI) and bevacizumab in first line. The association between splenic volume, and PFS and OS was evaluated by univariate and multivariable Cox analyses. The relation between circulating monocytic Myeloid derived suppressor cells (mMDSC) and splenomegaly was also determined. Results: Baseline splenic volume > 180 mL was associated with poor PFS (median PFS = 9.2 versus 11.1 months; log-rank p = 0.0125), but was not statistically associated with OS (median OS = 22.6 versus 28.5 months; log-rank p = 0.1643). The increase in splenic volume at 3 months had no impact on PFS (HR 0.928; log-rank p = 0.56) or on OS (HR 0.843; log-rank p = 0.21). Baseline splenic volume was positively correlated with the level of baseline circulating mMDSC (r = 0.48, p-value = 0.031). Conclusion: Baseline splenomegaly is a prognostic biomarker in patients with mCRC treated with FOLFIRI and bevacizumab, and a surrogate marker of MDSC accumulation.
A Novel Serum Metabolomic Profile for the Differential Diagnosis of Distal Cholangiocarcinoma and Pancreatic Ductal Adenocarcinoma
Authors: Macias Rocio I. R. , Muñoz-Bellvís Luis , Sánchez-Martín Anabel , Arretxe Enara , Martínez-Arranz Ibon , Lapitz Ainhoa , Gutiérrez M. Laura , La Casta Adelaida La , Alonso Cristina , González Luis M. , Avila Matias A. , Martinez-Chantar Maria L. , Castro Rui E. , Bujanda Luis , Banales Jesus M. , Marin Jose J. G.
Published: June 2020

The diagnosis of adenocarcinomas located in the pancreas head, i.e., distal cholangiocarcinoma (dCCA) and pancreatic ductal adenocarcinoma (PDAC), constitutes a clinical challenge because they share many symptoms, are not easily distinguishable using imaging techniques and accurate biomarkers are not available. Searching for biomarkers with potential usefulness in the differential diagnosis of these tumors, we have determined serum metabolomic profiles in healthy controls and patients with dCCA, PDAC or benign pancreatic diseases (BPD). Ultra-high-performance liquid chromatography coupled to mass spectrometry (UHPLC-MS) analysis was performed in serum samples from dCCA (n = 34), PDAC (n = 38), BPD (n = 42) and control (n = 25) individuals, divided into discovery and validation cohorts. This approach permitted 484 metabolites to be determined, mainly lipids and amino acids. The analysis of the results led to the proposal of a logistic regression model able to discriminate patients with dCCA and PDAC (AUC value of 0.888) based on the combination of serum levels of nine metabolites (acylcarnitine AC(16:0), ceramide Cer(d18:1/24:0), phosphatidylcholines PC(20:0/0:0) and PC(O-16:0/20:3), lysophosphatidylcholines PC(20:0/0:0) and PC(0:0/20:0), lysophosphatidylethanolamine PE(P-18:2/0:0), and sphingomyelins SM(d18:2/22:0) and SM(d18:2/23:0)) and CA 19-9. In conclusion, we propose a novel specific panel of serum metabolites that can help in the differential diagnosis of dCCA and PDAC. Further validation of their clinical usefulness in prospective studies is required.
Metabolic Escape Routes of Cancer Stem Cells and Therapeutic Opportunities
Authors: Turdo Alice , Porcelli Gaetana , D’Accardo Caterina , Di Franco Simone , Verona Francesco , Forte Stefano , Giuffrida Dario , Memeo Lorenzo , Todaro Matilde , Stassi Giorgio
Published: June 2020

Although improvement in early diagnosis and treatment ameliorated life expectancy of cancer patients, metastatic disease still lacks effective therapeutic approaches. Resistance to anticancer therapies stems from the refractoriness of a subpopulation of cancer cells—termed cancer stem cells (CSCs)—which is endowed with tumor initiation and metastasis formation potential. CSCs are heterogeneous and diverge by phenotypic, functional and metabolic perspectives. Intrinsic as well as extrinsic stimuli dictated by the tumor microenvironment (TME)have critical roles in determining cell metabolic reprogramming from glycolytic toward an oxidative phenotype and vice versa, allowing cancer cells to thrive in adverse milieus. Crosstalk between cancer cells and the surrounding microenvironment occurs through the interchange of metabolites, miRNAs and exosomes that drive cancer cells metabolic adaptation. Herein, we identify the metabolic nodes of CSCs and discuss the latest advances in targeting metabolic demands of both CSCs and stromal cells with the scope of improving current therapies and preventing cancer progression.
BAX Redistribution Induces Apoptosis Resistance and Selective Stress Sensitivity in Human HCC
Authors: Funk Kathrin , Czauderna Carolin , Klesse Ramona , Becker Diana , Hajduk Jovana , Oelgeklaus Aline , Reichenbach Frank , Fimm-Todt Franziska , Lauterwasser Joachim , Galle Peter R. , Marquardt Jens U. , Edlich Frank
Published: June 2020

Cancer therapies induce differential cell responses, ranging from efficient cell death to complete stress resistance. The BCL-2 proteins BAX and BAK govern the cellular decision between survival and mitochondrial apoptosis. Therefore, the status of BAX/BAK regulation can predict the cellular apoptosis predisposition. Relative BAX/BAK localization was analyzed in tumor and corresponding non-tumor samples from 34 hepatocellular carcinoma (HCC) patients. Key transcriptome changes and gene expression profiles related to the status of BAX regulation were applied to two independent cohorts including over 500 HCC patients. The prediction of apoptotic response was tested using cell lines and polyclonal tumor isolates. Cellular protection from BAX was confirmed by challenging cells with mitochondrial BAX. We discovered a subgroup of HCC with selective protection from BAX-dependent apoptosis. BAX-protected tumors showed enrichment of signaling pathways associated with oxidative stress response and DNA repair as well as increased genetic heterogeneity. Gene expression profiles characteristic to BAX-specific protection are enriched in poorly differentiated HCCs and show significant association to the overall survival of HCC patients. Consistently, addiction to DNA repair of BAX-protected cancer cells caused selective sensitivity to PARP inhibition. Molecular characteristics of BAX-protected HCC were enriched in cells challenged with mitochondrial BAX. Our results demonstrate that predisposition to BAX activation impairs tumor biology in HCC. Selective BAX inhibition or lack thereof delineates distinct subgroups of HCC patients with molecular features and differential response pattern to apoptotic stimuli and inhibition of DNA repair mechanisms.
Highly Efficient and Reusable Alkyne Hydrosilylation Catalysts Based on Rhodium Complexes Ligated by Imidazolium-Substituted Phosphine
Authors: Bartlewicz Olga , Jankowska-Wajda Magdalena , Maciejewski Hieronim
Published: June 2020

Rhodium complexes ligated by imidazolium-substituted phosphine were used as catalysts in the hydrosilylation of alkynes (1-heptyne, 1-octyne, and phenylacetylene) with 1,1,1,3,5,5,5-heptamethyltrisiloxane (HMTS) or triethylsilane (TES). In all cases, the above complexes showed higher activity and selectivity compared to their precursors ([Rh(PPh3)3Cl] and [{Rh(µ-Cl)(cod)}2]). In the reactions with aliphatic alkynes (both when HMTS and TES were used as hydrosilylating agents), β(Z) isomer was mainly formed, but, in the reaction of phenylacetylene with TES, the β(E) product was formed. The catalysts are very durable, stable in air and first and foremost insoluble in the reactants which facilitated their isolation and permitted their multiple use in subsequent catalytic runs. They make a very good alternative to the commonly used homogeneous catalysts.
Toxicity Reduction of Industrial and Municipal Wastewater by Advanced Oxidation Processes (Photo-Fenton, UVC/H2O2, Electro-Fenton and Galvanic Fenton): A Review
Authors: Rueda-Márquez Juan José , Levchuk Irina , Manzano Manuel , Sillanpää Mika
Published: June 2020

The application of Fenton-based advanced oxidation processes (AOPs), such as photo-Fenton or electro-Fenton for wastewater treatment have been extensively studied in recent decades due to its high efficiency for the decomposition of persistent organic pollutants. Usually Fenton-based AOPs are used for the degradation of targeted pollutant or group of pollutants, which often leads to the formation of toxic by-products possessing a potential environmental risk. In this work, we have collected and reviewed recent findings regarding the feasibility of Fenton-based AOPs (photo-Fenton, UVC/H2O2, electro-Fenton and galvanic Fenton) for the detoxification of real municipal and industrial wastewaters. More specifically, operational conditions, relevance and suitability of different bioassays for the toxicity assessment of various wastewater types, cost estimation, all of which compose current challenges for the application of these AOPs for real wastewater detoxification are discussed.
High Yield to 1-Propanol from Crude Glycerol Using Two Reaction Steps with Ni Catalysts
Authors: Gatti Martín N. , Cerioni Julieta L. , Pompeo Francisco , Santori Gerardo F. , Nichio Nora N.
Published: June 2020

The objective of the present work is to achieve high yield to 1-propanol (1-POH) by crude glycerol hydrogenolysis in liquid phase and find an alternative to the use of noble metals by employing Ni catalysts. Two Ni catalysts with different supports, alumina (γ-Al2O3), and a phosphorous-impregnated carbon composite (CS-P) were studied and characterized in order to determine their acid properties and metallic phases. With the Ni/γ-Al2O3 catalyst, which presented small particles of metallic Ni interacting with the acid sites of the support, it was possible to obtain a complete conversion of crude glycerol with high selectivity towards 1,2-propylene glycol (1,2 PG) (87%) at 220 °C whereas with the Ni/CS-P catalyst, the presence of AlPOx species and the Ni2P metallic phase supplied acidity to the catalyst, which promoted the C-O bond cleavage reaction of the secondary carbon of 1,2 PG to obtain 1-POH with very high selectivity (71%) at 260 °C. It was found that the employment of two consecutive reaction stages (first with Ni/ γ-Al2O3 at 220 °C and then with Ni/CS-P at 260 °C) allows reaching levels of selectivity and a yield to 1-POH (79%) comparable to noble metal-based catalysts.
Blocking the Bromodomains Function Contributes to Disturbances in Alga Chara vulgaris Spermatids Differentiation
Authors: Wojtczak Agnieszka
Published: June 2020

Bromodomain containing (BRD) proteins play an essential role in many cellular processes. The aim of this study was to estimate activity of bromodomains during alga Chara vulgaris spermatids differentiation. The effect of a bromodomain inhibitor, JQ1 (100 μM), on the distribution of individual stages of spermatids and their ultrastructure was studied. The material was Feulgen stained and analysed in an electron microscope. JQ1 caused shortening of the early stages of spermiogenesis and a reverse reaction at the later stages. Additionally, in the same antheridium, spermatids at distant developmental stages were present. On the ultrastructural level, chromatin fibril system disorders and significantly distended endoplasmic reticulum (ER) cisternae already at the early stages were observed. Many autolytic vacuoles were also visible. The ultrastructural disturbances intensified after prolonged treatment with JQ1. The obtained data show that JQ1 treatment led to changes in the spermatid number and disturbances in chromatin condensation and to cytoplasm reduction. The current studies show some similarities between C. vulgaris and mammals spermiogenesis. Taken together, these results suggest that JQ1 interferes with the spermatid differentiation on many interdependent levels and seems to induce ER stress, which leads to spermatid degeneration. Studies on the role of bromodomains in algae spermiogenesis have not been conducted so far.
Human Liver-Derived Extracellular Matrix for the Culture of Distinct Human Primary Liver Cells
Authors: Alevra Sarika Niki , Payen Valéry L. , Fléron Maximilien , Ravau Joachim , Brusa Davide , Najimi Mustapha , De Pauw Edwin , Eppe Gauthier , Mazzucchelli Gabriel , Sokal Etienne M. , des Rieux Anne , El Taghdouini Adil
Published: June 2020

The lack of robust methods to preserve, purify and in vitro maintain the phenotype of the human liver’s highly specialized parenchymal and non-parenchymal cell types importantly hampers their exploitation for the development of research and clinical applications. There is in this regard a growing interest in the use of tissue-specific extracellular matrix (ECM) to provide cells with an in vitro environment that more closely resembles that of the native tissue. In the present study, we have developed a method that allows for the isolation and downstream application of the human liver’s main cell types from cryopreserved material. We also isolated and solubilized human liver ECM (HL-ECM), analyzed its peptidomic and proteomic composition by mass spectrometry and evaluated its interest for the culture of distinct primary human liver cells. Our analysis of the HL-ECM revealed proteomic diversity, type 1 collagen abundance and partial loss of integrity following solubilization. Solubilized HL-ECM was evaluated either as a coating or as a medium supplement for the culture of human primary hepatocytes, hepatic stellate cells and liver sinusoidal endothelial cells. Whereas the solubilized HL-ECM was suitable for cell culture, its impact on the phenotype and/or functionality of the human liver cells was limited. Our study provides a first detailed characterization of solubilized HL-ECM and a first report of its influence on the culture of distinct human primary liver cells.
A Role for mir-26a in Stress: A Potential sEV Biomarker and Modulator of Excitatory Neurotransmission
Authors: Lafourcade Carlos Andrés , Fernández Anllely , Ramírez Juan Pablo , Corvalán Katherine , Carrasco Miguel Ángel , Iturriaga Andrés , Bátiz Luis Federico , Luarte Alejandro , Wyneken Ursula
Published: June 2020

Stress is a widespread problem in today’s societies, having important consequences on brain function. Among the plethora of mechanisms involved in the stress response at the molecular level, the role of microRNAs (miRNAs) is beginning to be recognized. The control of gene expression by these noncoding RNAs makes them essential regulators of neuronal and synaptic physiology, and alterations in their levels have been associated with pathological conditions and mental disorders. In particular, the excitatory (i.e., glutamate-mediated) neurotransmission is importantly affected by stress. Here, we found that loss of miR-26a-5p (miR-26a henceforth) function in primary hippocampal neurons increased the frequency and amplitude of miniature excitatory currents, as well as the expression levels of the excitatory postsynaptic scaffolding protein PSD95. Incubation of primary hippocampal neurons with corticosterone downregulated miR-26a, an effect that mirrored our in vivo results, as miR-26a was downregulated in the hippocampus as well as in blood serum-derived small extracellular vesicles (sEVs) of rats exposed to two different stress paradigms by movement restriction (i.e., stress by restraint in cages or by complete immobilization in bags). Overall, these results suggest that miR-26a may be involved in the generalized stress response and that a stress-induced downregulation of miR-26a could have long-term effects on glutamate neurotransmission.
Fibroblasts Colonizing Nerve Conduits Express High Levels of Soluble Neuregulin1, a Factor Promoting Schwann Cell Dedifferentiation
Authors: Fornasari Benedetta E. , El Soury Marwa , Nato Giulia , Fucini Alessia , Carta Giacomo , Ronchi Giulia , Crosio Alessandro , Perroteau Isabelle , Geuna Stefano , Raimondo Stefania , Gambarotta Giovanna
Published: June 2020

Conduits for the repair of peripheral nerve gaps are a good alternative to autografts as they provide a protected environment and a physical guide for axonal re-growth. Conduits require colonization by cells involved in nerve regeneration (Schwann cells, fibroblasts, endothelial cells, macrophages) while in the autograft many cells are resident and just need to be activated. Since it is known that soluble Neuregulin1 (sNRG1) is released after injury and plays an important role activating Schwann cell dedifferentiation, its expression level was investigated in early regeneration steps (7, 14, 28 days) inside a 10 mm chitosan conduit used to repair median nerve gaps in Wistar rats. In vivo data show that sNRG1, mainly the isoform α, is highly expressed in the conduit, together with a fibroblast marker, while Schwann cell markers, including NRG1 receptors, were not. Primary culture analysis shows that nerve fibroblasts, unlike Schwann cells, express high NRG1α levels, while both express NRG1β. These data suggest that sNRG1 might be mainly expressed by fibroblasts colonizing nerve conduit before Schwann cells. Immunohistochemistry analysis confirmed NRG1 and fibroblast marker co-localization. These results suggest that fibroblasts, releasing sNRG1, might promote Schwann cell dedifferentiation to a “repair” phenotype, contributing to peripheral nerve regeneration.
Biomarkers in Hepatocellular Carcinoma: Diagnosis, Prognosis and Treatment Response Assessment
Authors: Piñero Federico , Dirchwolf Melisa , Pessôa Mário G.
Published: June 2020

Hepatocellular carcinoma (HCC) is one of the main cancer-related causes of death worldwide. Thus, there is a constant search for improvement in screening, diagnosis, and treatment strategies to improve the prognosis of this malignancy. The identification of useful biomarkers for surveillance and early HCC diagnosis is still deficient, with available serum biomarkers showing low sensitivity and heterogeneous specificity despite different cut-off points, even when assessed longitudinally, or with a combination of serum biomarkers. In contrast, HCC biomarkers used for prognostic (when associated with clinical outcomes) or predictive purposes (when associated with treatment response) may have an increased clinical role in the near future. Furthermore, some serum biomarkers are already implicated as a treatment selection tool, whether to provide access to certain therapies or to assess clinical benefit after treatment. In the present review we will discuss the clinical utility and foreseen future of HCC biomarkers implicated in surveillance, diagnosis, prognosis, and post-treatment assessment.
Intrinsic Abnormalities of Cystic Fibrosis Airway Connective Tissue Revealed by an In Vitro 3D Stromal Model
Authors: Mazio Claudia , Scognamiglio Laura S. , De Cegli Rossella , Galietta Luis J. V. , Di Bernardo Diego , Casale Costantino , Urciuolo Francesco , Imparato Giorgia , Netti Paolo A.
Published: June 2020

Cystic fibrosis is characterized by lung dysfunction involving mucus hypersecretion, bacterial infections, and inflammatory response. Inflammation triggers pro-fibrotic signals that compromise lung structure and function. At present, several in vitro cystic fibrosis models have been developed to study epithelial dysfunction but none of these focuses on stromal alterations. Here we show a new cystic fibrosis 3D stromal lung model made up of primary fibroblasts embedded in their own extracellular matrix and investigate its morphological and transcriptomic features. Cystic fibrosis fibroblasts showed a high proliferation rate and produced an abundant and chaotic matrix with increased protein content and elastic modulus. More interesting, they had enhanced pro-fibrotic markers and genes involved in epithelial function and inflammatory response. In conclusion, our study reveals that cystic fibrosis fibroblasts maintain in vitro an activated pro-fibrotic state. This abnormality may play in vivo a role in the modulation of epithelial and inflammatory cell behavior and lung remodeling. We argue that the proposed bioengineered model may provide new insights on epithelial/stromal/inflammatory cells crosstalk in cystic fibrosis, paving the way for novel therapeutic strategies.
On the Efficiency of Using Transpiration Cooling to Mitigate Urban Heat
Authors: Gao Kai , Santamouris Mattheos , Feng Jie
Published: June 2020

Trees are considered to be effective for the mitigation of urban overheating, and the cooling capacity of trees mainly comes from two mechanisms: transpiration and shading. This study explores the transpiration cooling of large trees in urban environments where the sea breeze dominates the climate. In the experiment, sap flow sensors were used to measure the transpiration rate of two large trees located in Sydney over one year. Also, the temperature difference between the inside and outside of the canopy, as well as the vertical temperature distribution below the canopy, were measured during summer. In this experiment, the temperature under the canopies decreased by about 0.5 degrees from a 0.5 m height to a 3.5 m height, and the maximum temperature difference between the inside and outside of the canopy was about 2 degrees. After applying a principal component analysis of multiple variables, we found that when a strong sea breeze is the primary cooling mechanism, the sap flow still makes a considerable contribution to cooling. Further, the sea breeze and the transpiration cooling of trees are complementary. In conclusion, the characteristics of synoptic conditions must be fully considered when planting trees for mitigation purposes. Since the patterns of sea breeze and sap often do not coincide, the transpiration cooling of trees is still effective when the area is dominated by sea breeze.
Control of Lateral Composition Distribution in Graded Films of Soluble Solid Systems A1−xBx by Partitioned Dual-Beam Pulsed Laser Deposition
Authors: Sakai Joe , Roque José Manuel Caicedo , Vales-Castro Pablo , Padilla-Pantoja Jessica , Sauthier Guillaume , Catalan Gustau , Santiso José
Published: June 2020

Lateral compositionally-graded thin films are powerful media for the observation of phase boundaries as well as for high-throughput materials exploration. We herein propose a method to prepare epitaxial lateral compositionally-graded films using a dual-beam pulsed laser deposition (PLD) method with two targets separated by a partition. Tuning the ambient pressure and the partition—substrate gap makes it possible to control of the gradient length of the deposits at the small sizes (≤ 10 mm) suitable for commercial oxide single crystal substrates. A simple Monte Carlo simulation qualitatively reproduced the characteristic features of the lateral thickness distribution. To demonstrate this method, we prepared (1−x)PbTiO3—xPbZrO3 and (1−x)LaMnO3—xLa0.6Sr0.4MnO3 films with lateral composition gradient widths of 10 and 1 mm, respectively, with the partitioned dual PLD.
Classification of Vowels from Imagined Speech with Convolutional Neural Networks
Authors: Tamm Markus-Oliver , Muhammad Yar , Muhammad Naveed
Published: June 2020

Imagined speech is a relatively new electroencephalography (EEG) neuro-paradigm, which has seen little use in Brain-Computer Interface (BCI) applications. Imagined speech can be used to allow physically impaired patients to communicate and to use smart devices by imagining desired commands and then detecting and executing those commands in a smart device. The goal of this research is to verify previous classification attempts made and then design a new, more efficient neural network that is noticeably less complex (fewer number of layers) that still achieves a comparable classification accuracy. The classifiers are designed to distinguish between EEG signal patterns corresponding to imagined speech of different vowels and words. This research uses a dataset that consists of 15 subjects imagining saying the five main vowels (a, e, i, o, u) and six different words. Two previous studies on imagined speech classifications are verified as those studies used the same dataset used here. The replicated results are compared. The main goal of this study is to take the proposed convolutional neural network (CNN) model from one of the replicated studies and make it much more simpler and less complex, while attempting to retain a similar accuracy. The pre-processing of data is described and a new CNN classifier with three different transfer learning methods is described and used to classify EEG signals. Classification accuracy is used as the performance metric. The new proposed CNN, which uses half as many layers and less complex pre-processing methods, achieved a considerably lower accuracy, but still managed to outperform the initial model proposed by the authors of the dataset by a considerable margin. It is recommended that further studies investigating classifying imagined speech should use more data and more powerful machine learning techniques. Transfer learning proved beneficial and should be used to improve the effectiveness of neural networks.
Towards an Understanding of Crystallization by Attachment
Authors: Pan Haihua , Tang Ruikang
Published: June 2020

Crystallization via particle attachment was used in a unified model for both classical and non-classical crystallization pathways, which have been widely observed in biomimetic mineralization and geological fields. However, much remains unknown about the detailed processes and driving mechanisms for the attachment. Here, we take calcite crystal as a model mineral to investigate the detailed attachment process using in situ Atomic Force Microscopy (AFM) force measurements and molecular dynamics simulations. The results show that hydration layers hinder the attachment; however, in supersaturated solutions, ionic bridges are formed between crystal gaps as a result of capillary condensation, which might enhance the aggregation of calcite crystals. These findings provide a more detailed understanding of the crystal attachment, which is of vital importance for a better understanding of mineral formation under biological and geological environments with a wide range of chemical and physical conditions.
Crystal Chemistry of Stanfieldite, Ca7M2Mg9(PO4)12 (M = Ca, Mg, Fe2+), a Structural Base of Ca3Mg3(PO4)4 Phosphors
Authors: Britvin Sergey N. , Krzhizhanovskaya Maria G. , Bocharov Vladimir N. , Obolonskaya Edita V.
Published: June 2020

Stanfieldite, natural Ca-Mg-phosphate, is a typical constituent of phosphate-phosphide assemblages in pallasite and mesosiderite meteorites. The synthetic analogue of stanfieldite is used as a crystal matrix of luminophores and frequently encountered in phosphate bioceramics. However, the crystal structure of natural stanfieldite has never been reported in detail, and the data available so far relate to its synthetic counterpart. We herein provide the results of a study of stanfieldite from the Brahin meteorite (main group pallasite). The empirical formula of the mineral is Ca8.04Mg9.25Fe0.72Mn0.07P11.97O48. Its crystal structure has been solved and refined to R1 = 0.034. Stanfieldite from Brahin is monoclinic, C2/c, a 22.7973(4), b 9.9833(2), c 17.0522(3) Å, β 99.954(2)°, V 3822.5(1)Å3. The general formula of the mineral can be expressed as Ca7M2Mg7(PO4)12 (Z = 4), where the M = Ca, Mg, Fe2+. Stanfieldite from Brahin and a majority of other meteorites correspond to a composition with an intermediate Ca≈Mg occupancy of the M5A site, leading to the overall formula ~Ca7(CaMg)Mg9(PO4)12 ≡ Ca4Mg5(PO4)6. The mineral from the Lunar sample “rusty rock” 66095 approaches the M = Mg end member, Ca7Mg2Mg9(PO4)12. In lieu of any supporting analytical data, there is no evidence that the phosphor base with the formula Ca3Mg3(PO4)4 does exist.
Extension of Elastic Models to Decagonal Quasicrystals
Authors: Li Wu , Shi Yiqing
Published: June 2020

The main design of this paper is to adopt potential functions for solving plane defect problems originating from two-dimensional decagonal quasicrystals. First, we analyze the strict potential function theory for the plane problems of two-dimensional quasicrystals. To clarify effectiveness of the method, we give some examples and the results which can be precisely determined, including the elasticity and fracture theories of two-dimensional quasicrystals. These results maybe play a positive role in studying the fracture of two-dimensional quasicrystals in the future.
Rusty Blackbird Habitat Selection and Survivorship during Nesting and Post-Fledging
Authors: Wohner Patricia J. , Foss Carol R. , Cooper Robert J.
Published: June 2020

Rusty blackbird (Euphagus carolinus) populations have declined dramatically since the 1970s and the cause of decline is still unclear. As is the case for many passerines, most research on rusty blackbirds occurs during the nesting period. Nest success is relatively high in most of the rusty blackbird’s range, but survival during the post-fledging period, when fledgling songbirds are particularly vulnerable, has not been studied. We assessed fledgling and adult survivorship and nest success in northern New Hampshire from May to August in 2010 to 2012. We also assessed fledgling and adult post-fledging habitat selection and nest-site selection. The likelihood of rusty blackbirds nesting in a given area increased with an increasing proportion of softwood/mixed-wood sapling stands and decreasing distances to first to sixth order streams. Wetlands were not selected for nest sites, but both adults and fledglings selected wetlands for post-fledging habitat. Fledglings and adults selected similar habitat post-fledging, but fledglings were much more likely to be found in habitat with an increasing proportion of softwood/mixed-wood sapling stands and were more likely to be closer to streams than adults. No habitat variables selected during nesting or post-fledging influenced daily survival rates, which were relatively low for adults over the 60-day study periods (males 0.996, females 0.998). Fledgling survival rates (0.89) were much higher than reported for species of similar size.
Balloon Pulmonary Angioplasty with Stent Implantation as a Treatment of Proximal Chronic Thromboembolic Pulmonary Hypertension
Authors: Darocha Szymon , Pietura Radosław , Banaszkiewicz Marta , Pietrasik Arkadiusz , Kownacki Łukasz , Torbicki Adam , Kurzyna Marcin
Published: June 2020

We present a case of a 67-year-old female with proximal chronic thromboembolic pulmonary hypertension (CTEPH), disqualified from pulmonary endarterectomy due to multiple comorbidities and high risk-to-benefit ratio as assessed by multidisciplinary CTEPH team. She was referred for balloon pulmonary angioplasty (BPA) and underwent three sessions with balloon catheters up to 8 mm diameter. During the second procedure, the elastic recoil phenomenon was observed in the treated post-thrombotic lesion of the right lower lobe artery, which made the balloon angioplasty ineffective. It was decided to implant a self-expanding stent for the prevention of restenosis. The procedure resulted in significant improvement of regional perfusion, as confirmed by control angiography. We feel that it contributed to the significant improvement of hemodynamic parameters and exercise capacity, as assessed three months after the last BPA procedure. In conclusion, pulmonary artery stenting may be an option in proximal CTEPH when elastic recoil phenomenon makes balloon angioplasty of a large vessel ineffective.
Bayesian Model Averaging with the Integrated Nested Laplace Approximation
Authors: Gómez-Rubio Virgilio , Bivand Roger S. , Rue Håvard
Published: June 2020

The integrated nested Laplace approximation (INLA) for Bayesian inference is an efficient approach to estimate the posterior marginal distributions of the parameters and latent effects of Bayesian hierarchical models that can be expressed as latent Gaussian Markov random fields (GMRF). The representation as a GMRF allows the associated software R-INLA to estimate the posterior marginals in a fraction of the time as typical Markov chain Monte Carlo algorithms. INLA can be extended by means of Bayesian model averaging (BMA) to increase the number of models that it can fit to conditional latent GMRF. In this paper, we review the use of BMA with INLA and propose a new example on spatial econometrics models.
Declining Protection for Vietnamese Agriculture under Trade Liberalization: Evidence from an Input–Output Analysis
Authors: Ho Dinh Bao , Nguyen Phuc Hai , Bui Trinh , Nguyen Hau
Published: June 2020

This study aims to assess the protection for Vietnamese agriculture under trade liberalization based on the input–output approach. From a theoretical perspective, the authors develop a general framework to estimate the effective rate of protection using an input–output table, taking into account tariffs, subsidies and value-added tax. Based on the data of 2012 and 2016, with a projection to 2020, the empirical results reveal that agricultural production, which is considered as Vietnam’s comparative advantage, is insignificantly protected. From the year 2012 to 2016, the effective rate of protection declined for primary agriculture and its supporting sectors, and would become negative by 2020. This implies that Vietnamese farmers are at a disadvantage due to the effect of trade liberalization. Furthermore, it is empirically revealed that the primary agricultural sector has a high value-added multiplier, which means a significant contribution to the domestic economy, is not protected by the government’s tax and tariff policies. Based on the study results, the authors suggest some policy recommendations to improve the situation, which are focused on the reduction of the value-added tax rate on inputs, while making industries with a high spillover effect to the domestic economy a key priority.
Validation of Forward Voltage Method to Estimate Cracks of the Solder Joints in High Power LED
Authors: Pinti Federica , Belli Alberto , Palma Lorenzo , Gattari Massimo , Pierleoni Paola
Published: June 2020

The Light Emitting Diode (LED) has many advantages compared to traditional lamps, such as a long lifetime, color rendering and energy saving. It requires good thermal management, since as the temperature increases, the lifetime decreases. Furthermore, the presence of cracks in the Solder Joint of an LED (SJL) compromises the correct dispersion of heat and causes the joint fatigue. This can lead to a decrease in the lifetime of the assembled LED. In this study, we validated that an SJL can be considered faulty if the Forward Voltage (Vf) acquired before and after thermal cycles increases by more than 2%. The voltage measurement method was validated by comparing the results with the techniques commonly used to evaluate the defects of a solder joint as the X-ray analysis and the metallographic section. The failure analysis results present the probability of failure and the lifetime of the SJL achieved by analyzing the data using the Norris–Landberg Model. The lifetime calculated over 1800 SJLs considered in the validation process is greater than 20 years for 95.9% of the tested LEDs.
Improvements on a Sensorless Scheme for a Surface-Mounted Permanent Magnet Synchronous Motor Using Very Low Voltage Injection
Authors: Pando-Acedo Jaime , Romero-Cadaval Enrique , Milanes-Montero Maria Isabel , Barrero-Gonzalez Fermin
Published: June 2020

Sensorless control of electrical drives is still a difficult task, especially in the lower speed region. Moreover, when the machine has a low saliency such as in the case of Surface Mounted Permanent Magnet Synchronous Motor (SMPMSM), high frequency injection techniques are even more challenging. In this paper, an enhanced demodulation algorithm for the sensorless control of a SMPMSM is proposed. The new scheme uses the high frequency injection in the Synchronous Reference Frame (SRF) and employs also the negative sequence content of the measured current for improved accuracy. This allows an improved performance with a lower amplitude of the injected signal, thus reducing the noise and additional losses in the motor. It is found that, by using both components with the algorithm developed the estimation ripple can be greatly reduced and the system can operate properly with a voltage injection of only 2.17% of the rated motor voltage, which is lower than most found in the literature, specially for low saliency machines. Simulations tests are carried out for the validation of the proposed method and experimental results in a 6.7 kW SMPMSM confirm its usefulness and correct operation with a reduced voltage injection, both in no-load and load conditions, for different low speeds, including start-up.
Singularly Perturbed Modeling and LQR Controller Design for a Fuel Cell System
Authors: Kodra Kliti , Zhong Ningfan
Published: June 2020

Modeling and control of proton-exchange membrane fuel cells (PEMFC) has become a very popular research topic lately due to the increasing use of renewable energy. Despite this fact, most of the work in the current literature only studies standard dynamical models without taking into consideration possible parasitics such as small gas flow perturbations that could be available in the system. This paper addresses this issue by elaborating on time-scale modeling of an augmented eighteenth-order PEMFC-reformer system via singular perturbation theory. The latter captures time scales that arise in the model due to the presence of small perturbations. Specifically, a novel and efficient algorithm that helps identify the presence of different time-scales is developed. In addition, the method converts an implicit singularly perturbed model into an explicit equivalent where the time-scales are evident. Using this algorithm, a complete singularly perturbed dynamic model of the augmented eighteenth-order PEMFC-reformer system is obtained. Modeling of the PEMFC-reformer system is followed by linear quadratic regulator (LQR) design for the individual time-scales present in the system.
Maritime Transport in a Life Cycle Perspective: How Fuels, Vessel Types, and Operational Profiles Influence Energy Demand and Greenhouse Gas Emissions
Authors: Seithe Grusche J. , Bonou Alexandra , Giannopoulos Dimitrios , Georgopoulou Chariklia A. , Founti Maria
Published: June 2020

A “Well-to-Propeller” Life Cycle Assessment of maritime transport was performed with a European geographical focus. Four typical types of vessels with specific operational profiles were assessed: a container vessel and a tanker (both with 2-stroke engines), a passenger roll-on/roll-off (Ro-Pax) and a cruise vessel (both with 4-stroke engines). All main engines were dual fuel operated with Heavy Fuel Oil (HFO) or Liquefied Natural Gas (LNG). Alternative onshore and offshore fuel supply chains were considered. Primary energy use and greenhouse gas emissions were assessed. Raw material extraction was found to be the most impactful life cycle stage (~90% of total energy use). Regarding greenhouse gases, liquefaction was the key issue. When transitioning from HFO to LNG, the systems were mainly influenced by a reduction in cargo capacity due to bunkering requirements and methane slip, which depends on the fuel supply chain (onshore has 64% more slip than offshore) and the engine type (4-stroke engines have 20% more slip than 2-stroke engines). The combination of alternative fuel supply chains and specific operational profiles allowed for a complete system assessment. The results demonstrated that multiple opposing drivers affect the environmental performance of maritime transport, a useful insight towards establishing emission abatement strategies.
Real Time Design and Implementation of State of Charge Estimators for a Rechargeable Lithium-Ion Cobalt Battery with Applicability in HEVs/EVs—A Comparative Study
Authors: Tudoroiu Nicolae , Zaheeruddin Mohammed , Tudoroiu Roxana-Elena
Published: June 2020

Estimating the state of charge (SOC) of Li-ion batteries is an essential task of battery management systems for hybrid and electric vehicles. Encouraged by some preliminary results from the control systems field, the goal of this work is to design and implement in a friendly real-time MATLAB simulation environment two Li-ion battery SOC estimators, using as a case study a rechargeable battery of 5.4 Ah cobalt lithium-ion type. The choice of cobalt Li-ion battery model is motivated by its promising potential for future developments in the HEV/EVs applications. The model validation is performed using the software package ADVISOR 3.2, widely spread in the automotive industry. Rigorous performance analysis of both SOC estimators is done in terms of speed convergence, estimation accuracy and robustness, based on the MATLAB simulation results. The particularity of this research work is given by the results of its comprehensive and exciting comparative study that successfully achieves all the goals proposed by the research objectives. In this scientific research study, a practical MATLAB/Simscape battery model is adopted and validated based on the results obtained from three different driving cycles tests and is in accordance with the required specifications. In the new modelling version, it is a simple and accurate model, easy to implement in real-time and offers beneficial support for the design and MATLAB implementation of both SOC estimators. Also, the adaptive extended Kalman filter SOC estimation performance is excellent and comparable to those presented in the state-of-the-art SOC estimation methods analysis.
Influence of Operating Conditions on the Thermal Behavior and Kinetics of Pine Wood Particles Using Thermogravimetric Analysis
Authors: Fraga Lelis Gonzaga , Silva João , Teixeira Senhorinha , Soares Delfim , Ferreira Manuel , Teixeira José
Published: June 2020

Although there are many studies available in literature about biomass pyrolysis or devolatilization using thermogravimetric analysis (TGA), the effects of important operating parameters have infrequently been investigated for pine wood particle combustion. Consequently, the present study investigates the influence of particle size (63 µm to 1 mm), heating rate (5 to 243 °C/min), and air flow rate (10 to 150 mL/min) on the mass loss of pine wood using TGA. Additionally, the kinetic parameters considering the different conditions were determined to be incorporated in a numerical model. The effect of the heating rate on the thermal decomposition behavior has shown that the thermogravimetric and derivative thermogravimetric curves were shifted to higher temperatures with the increase in the heating rate. In this way, the heating rate affects the temperature at which the highest mass loss rate occurs as well as its value. Furthermore, comparing the higher and lower heating rate, the time to complete the combustion and the release are around 22 times higher when a higher heating rate is applied. On the other hand, the effects of four different air flow rates were compared and similar results were obtained. Regarding the kinetic analysis, it was verified at various heating and air flow rates with different particle sizes that the highest activation energy was mostly obtained during char combustion (~131–229 kJ/mol). Furthermore, in the second stage higher heating rates had the highest reactivity, and in the third stage there were not too many changes. In terms of the effect of air flow rates, a maximum variation of 15 kJ/mol was obtained in the third stage and, therefore, no significant effect on the reactivity for all particles was found.
Fast Production of High Performance LiNi0.815Co0.15Al0.035O2 Cathode Material via Urea-Assisted Flame Spray Pyrolysis
Authors: Yudha Cornelius Satria , Muzayanha Soraya Ulfa , Rahmawati Mintarsih , Widiyandari Hendri , Sutopo Wahyudi , Nizam Muhammad , Santosa Sigit Puji , Purwanto Agus
Published: June 2020

The high throughput and rapid flame-assisted spray pyrolysis method has been adapted to synthesize cathode materials LiNi0.apCo0.15Al0.035O2 (NCA). This method is considered low cost and simple. By varying the precursor solution concentration and sintering temperature, the optimal condition was established at temperature sintering of 800 °C and precursor solution concentration of 1 M. X-ray diffraction patterns showed the as-prepared NCA particles exhibit a pure well-ordered hexagonal layer structure with high crystallinity. Polyhedral shaped micro-sized particles are confirmed by SEM images. Galvanostic charge–discharge tests were conducted using cylindrical full-cell utilizing artificial graphite as the anode. The highest specific initial discharge capacity measured between 2.7 and 4.3 V is 155 mAh g−1 with capacity retention of 92% after cycled at 0.2 C for 50 cycles. Thus, this method is considered as a satisfying approach for NCA mass production.
A Review of the Tools and Methods for Distribution Networks’ Hosting Capacity Calculation
Authors: Zain ul Abideen Mohammad , Ellabban Omar , Al-Fagih Luluwah
Published: June 2020

Integration of distributed energy resources (DERs) has numerous advantages as well as some disadvantages. To safely integrate DERs into a given distribution network and to maximize their benefits, it is important to thoroughly analyze the impact of DERs on that particular network. The maximum amount of DERs that a given distribution network can accommodate without causing technical problems or without requiring infrastructure modifications is defined as the hosting capacity (HC). In this work, a review of the recent literature regarding the HC is presented. The major limiting factors of HC are found to be voltage deviation, phase unbalance, thermal overload, power losses, power quality, installation location and protection devices’ miscoordination. The studies are found to employ one of four different methods for HC calculation: (i) deterministic, (ii) stochastic, (iii) optimization-based and (iv) streamlined. Commercially available tools for HC calculation are also presented. The review concludes that the choice of tools and methods for HC calculation depends on the data available and the type of study that is to be performed.
Hybrid Machine Learning Models for Classifying Power Quality Disturbances: A Comparative Study
Authors: Bravo-Rodríguez Juan Carlos , Torres Francisco J. , Borrás María D.
Published: June 2020

The economic impact associated with power quality (PQ) problems in electrical systems is increasing, so PQ improvement research becomes a key task. In this paper, a Stockwell transform (ST)-based hybrid machine learning approach was used for the recognition and classification of power quality disturbances (PQDs). The ST of the PQDs was used to extract significant waveform features which constitute the input vectors for different machine learning approaches, including the K-nearest neighbors’ algorithm (K-NN), decision tree (DT), and support vector machine (SVM) used for classifying the PQDs. The procedure was optimized by using the genetic algorithm (GA) and the competitive swarm optimization algorithm (CSO). To test the proposed methodology, synthetic PQD waveforms were generated. Typical single disturbances for the voltage signal, as well as complex disturbances resulting from possible combinations of them, were considered. Furthermore, different levels of white Gaussian noise were added to the PQD waveforms while maintaining the desired accuracy level of the proposed classification methods. Finally, all the hybrid classification proposals were evaluated and the best one was compared with some others present in the literature. The proposed ST-based CSO-SVM method provides good results in terms of classification accuracy and noise immunity.