bluuebunny/crossref_metadata_2025 huggingface dataset:
Point of Interest Matching between Different Geospatial Datasets
Authors: Deng Yue , Luo An , Liu Jiping , Wang Yong
Published: October 2019

Point of interest (POI) matching finds POI pairs that refer to the same real-world entity, which is the core issue in geospatial data integration. To address the low accuracy of geospatial entity matching using a single feature attribute, this study proposes a method that combines the D–S (Dempster–Shafer) evidence theory and a multiattribute matching strategy. During POI data preprocessing, this method calculates the spatial similarity, name similarity, address similarity, and category similarity between pairs from different geospatial datasets, using the multiattribute matching strategy. The similarity calculation results of these four types of feature attributes were used as independent evidence to construct the basic probability distribution. A multiattribute model was separately constructed using the improved combination rule of the D–S evidence theory, and a series of decision thresholds were set to give the final entity matching results. We tested our method with a dataset containing Baidu POIs and Gaode POIs from Beijing. The results showed the following—(1) the multiattribute matching model based on improved DS evidence theory had good performance in terms of precision, recall, and F1 for entity-matching from different datasets; (2) among all models, the model combining the spatial, name, and category (SNC) attributes obtained the best performance in the POI entity matching process; and (3) the method could effectively address the low precision of entity matching using a single feature attribute.
Non-Lytic Antibacterial Peptides That Translocate Through Bacterial Membranes to Act on Intracellular Targets
Authors: Cardoso Marlon H. , Meneguetti Beatriz T. , Costa Bruna O. , Buccini Danieli F. , Oshiro Karen G. N. , Preza Sergio L. E. , Carvalho Cristiano M. E. , Migliolo Ludovico , Franco Octávio L.
Published: October 2019

The advent of multidrug resistance among pathogenic bacteria has attracted great attention worldwide. As a response to this growing challenge, diverse studies have focused on the development of novel anti-infective therapies, including antimicrobial peptides (AMPs). The biological properties of this class of antimicrobials have been thoroughly investigated, and membranolytic activities are the most reported mechanisms by which AMPs kill bacteria. Nevertheless, an increasing number of works have pointed to a different direction, in which AMPs are seen to be capable of displaying non-lytic modes of action by internalizing bacterial cells. In this context, this review focused on the description of the in vitro and in vivo antibacterial and antibiofilm activities of non-lytic AMPs, including indolicidin, buforin II PR-39, bactenecins, apidaecin, and drosocin, also shedding light on how AMPs interact with and further translocate through bacterial membranes to act on intracellular targets, including DNA, RNA, cell wall and protein synthesis.
Multilevel Regulation of Peroxisomal Proteome by Post-Translational Modifications
Authors: Sandalio Luisa M. , Gotor Cecilia , Romero Luis C. , Romero-Puertas Maria C.
Published: October 2019

Peroxisomes, which are ubiquitous organelles in all eukaryotes, are highly dynamic organelles that are essential for development and stress responses. Plant peroxisomes are involved in major metabolic pathways, such as fatty acid β-oxidation, photorespiration, ureide and polyamine metabolism, in the biosynthesis of jasmonic, indolacetic, and salicylic acid hormones, as well as in signaling molecules such as reactive oxygen and nitrogen species (ROS/RNS). Peroxisomes are involved in the perception of environmental changes, which is a complex process involving the regulation of gene expression and protein functionality by protein post-translational modifications (PTMs). Although there has been a growing interest in individual PTMs in peroxisomes over the last ten years, their role and cross-talk in the whole peroxisomal proteome remain unclear. This review provides up-to-date information on the function and crosstalk of the main peroxisomal PTMs. Analysis of whole peroxisomal proteomes shows that a very large number of peroxisomal proteins are targeted by multiple PTMs, which affect redox balance, photorespiration, the glyoxylate cycle, and lipid metabolism. This multilevel PTM regulation could boost the plasticity of peroxisomes and their capacity to regulate metabolism in response to environmental changes.
In Vivo Bone Regeneration Induced by a Scaffold of Chitosan/Dicarboxylic Acid Seeded with Human Periodontal Ligament Cells
Authors: Sukpaita Teerawat , Chirachanchai Suwabun , Suwattanachai Pornchanok , Everts Vincent , Pimkhaokham Atiphan , Ampornaramveth Ruchanee Salingcarnboriboon
Published: October 2019

Chitosan/dicarboxylic acid (CS/DA) scaffold has been developed as a bone tissue engineering material. This study evaluated a CS/DA scaffold with and without seeded primary human periodontal ligament cells (hPDLCs) in its capacity to regenerate bone in calvarial defects of mice. The osteogenic differentiation of hPDLCs was analyzed by bone nodule formation and gene expression. In vivo bone regeneration was analyzed in mice calvarial defects. Eighteen mice were divided into 3 groups: one group with empty defects, one group with defects with CS/DA scaffold, and a group with defects with CS/DA scaffold and with hPDLCs. After 6 and 12 weeks, new bone formation was assessed using microcomputed tomography (Micro-CT) and histology. CS/DA scaffold significantly promoted in vitro osteoblast-related gene expression (RUNX2, OSX, COL1, ALP, and OPN) by hPDLCs. Micro-CT revealed that CS/DA scaffolds significantly promoted in vivo bone regeneration both after 6 and 12 weeks (p < 0.05). Histological examination confirmed these findings. New bone formation was observed in defects with CS/DA scaffold; being similar with and without hPDLCs. CS/DA scaffolds can be used as a bone regenerative material with good osteoinductive/osteoconductive properties.
Special Issue “Computational Social Science”
Authors: Iñiguez Gerardo , Jo Hang-Hyun , Kaski Kimmo
Published: October 2019

The last centuries have seen a great surge in our understanding and control of “simple” physical, chemical, and biological processes through data analysis and the mathematical modeling of their underlying dynamics [...]
Osteoporosis from an Endocrine Perspective: The Role of Hormonal Changes in the Elderly
Authors: Cannarella Rossella , Barbagallo Federica , Condorelli Rosita A. , Aversa Antonio , La Vignera Sandro , Calogero Aldo E.
Published: October 2019

Introduction: Osteoporosis is increasingly prevalent in the elderly, with fractures mostly occurring in women and men who are older than 55 and 65 years of age, respectively. The aim of this review was to examine the evidence regarding the influence of hormones on bone metabolism, followed by clinical data of hormonal changes in the elderly, in the attempt to provide possible poorly explored diagnostic and therapeutic candidate targets for the management of primary osteoporosis in the aging population. Material and methods: An extensive Medline search using PubMed, Embase, and Cochrane Library was performed. Results: While the rise in Thyroid-stimulating hormone (TSH) levels has a protective role on bone mass, the decline of estrogen, testosterone, Insulin-like growth factor 1 (IGF1), and vitamin D and the rise of cortisol, parathyroid hormone, and follicle-stimulating hormone (FSH) favor bone loss in the elderly. Particularly, the AA rs6166 FSH receptor (FSHR) genotype, encoding for a more sensitive FSHR than that encoded by the GG one, is associated with low total body mass density (BMD), independently of circulating estrogen. A polyclonal antibody with a FSHR-binding sequence against the β-subunit of murine FSH seems to be effective in ameliorating bone loss in ovariectomized mice. Conclusions: A complete hormonal assessment should be completed for both women and men during bone loss evaluation. Novel possible diagnostic and therapeutic tools might be developed for the management of male and female osteoporosis.
Correlation between B7-H4 and Survival of Non-Small-Cell Lung Cancer Patients Treated with Nivolumab
Authors: Genova Carlo , Boccardo Simona , Mora Marco , Rijavec Erika , Biello Federica , Rossi Giovanni , Tagliamento Marco , Dal Bello Maria , Coco Simona , Alama Angela , Vanni Irene , Barletta Giulia , Bianchi Rita , Maggioni Claudia , Bruzzi Paolo , Grossi Francesco
Published: October 2019

Reliable predictors of benefit from immune checkpoint inhibitors in non-small-cell lung cancer (NSCLC) are still limited. We aimed to evaluate the association between the expression of selected molecules involved in immune response and clinical outcomes in NSCLC patients receiving nivolumab. In our study, the outcomes of 46 NSCLC patients treated with nivolumab in second or subsequent lines (Nivolumab Cohort) were compared with the expression of PD-L1, PD-L2, PD-1, B7-H3, and B7-H4 assessed by immunohistochemistry (IHC). Samples from 17 patients (37.0%) in the Nivolumab Cohort were positive for B7-H4 expression. At univariate analyses, only B7-H4 expression was associated with significantly decreased progression-free survival (PFS; 1.7 vs. 2.0 months; p = 0.026) and with a disadvantage in terms of overall survival (OS) close to statistical significance (4.4 vs. 9.8 months; p = 0.064). At multivariate analyses, B7-H4 expression was significantly associated with decreased PFS (hazard ratio (HR) = 2.28; p = 0.021) and OS (HR = 2.38; p = 0.022). Subsequently, B7-H4 expression was compared with clinical outcomes of 27 NSCLC patients receiving platinum-based chemotherapy (Chemotherapy Cohort), but no significant association was observed. Our results suggest a negative predictive role of B7-H4 in a population of NSCLC treated with immune checkpoint inhibitors, which deserves further research.
Investigating Risk Factors for Complications after Ileostomy Reversal in Low Anterior Rectal Resection Patients: An Observational Study
Authors: Rubinkiewicz Mateusz , Witowski Jan , Wysocki Michał , Pisarska Magdalena , Kłęk Stanisław , Budzyński Andrzej , Pędziwiatr Michał
Published: October 2019

Introduction: Defunctioning ileostomy has been widely used in patients undergoing low anterior rectal resection to reduce the rate of postoperative leakage. It is still not clear whether interval between primary procedure and ileostomy reversal has an impact on treatment outcomes. Methods: In our prospective observational study we reviewed 164 consecutive cases of patients who underwent total mesorectal excision with primary anastomosis. Univariate and multivariate regression models were used to search for risk factors for prolonged length of stay and complications after defunctioning ileostomy reversal. Receiver operating characteristic curves were utilized to set cut-off points for prolonged length of stay and perioperative morbidity. Results: In total, 132 patients were included in the statistical analysis. The median interval between primary procedure and defunctioning ileostomy reversal was 134 (range: 17–754) days, while median length of stay was 5 days (4–6 interquartile range (IQR)). Prolonged length of stay cut-off was established at 6 days. Regression models revealed that interval between primary surgery and stoma closure as well as complications after primary procedure are risk factors for complications after defunctioning ileostomy reversal. Prolonged length of stay has been found to be related primarily to interval between primary surgery and stoma closure. Conclusions: In our study interval between primary surgery and stoma closure along with complication occurrence after primary procedure are risk factors for perioperative morbidity and prolonged length of stay (LOS) after ileostomy reversal. The effort should be made to minimize the interval to ileostomy reversal. However, randomized studies are necessary to avoid the bias which appears in this observational study and confirm our findings.
Iron Deficiency in Acute Decompensated Heart Failure
Authors: Beale Anna , Carballo David , Stirnemann Jerome , Garin Nicolas , Agoritsas Thomas , Serratrice Jacques , Kaye David , Meyer Philippe , Carballo Sebastian
Published: October 2019

The aim of this study was to characterize iron deficiency (ID) in acutely decompensated heart failure (ADHF) and identify whether ID is associated with dyspnea class, length of stay (LOS), biomarker levels, and echocardiographic indices of diastolic function in patients with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF). Consecutive patients admitted with ADHF at a single tertiary center were included. Demographic information, pathology investigations, and metrics regarding hospital stay and readmission were recorded. Patients were classified as having ‘absolute’ ID if they had a ferritin level <100 ng/mL; or ‘functional’ ID if they had a ferritin 100–200 ng/mL and a transferrin saturation <20%. Of 503 patients that were recruited, 270 (55%) had HFpEF, 160 (33%) had HFREF, and 57 (12%) had heart failure with mid-range ejection fraction. ID was present in 54% of patients with HFrEF and 56% of patients with HFpEF. In the HFpEF group, ID was associated with a LOS of 11 ± 7.7 vs. 9 ± 6 days in iron replete patients, p = 0.036, and remained an independent predictor of increased LOS in a multivariate linear regression incorporating comorbidities, age, and ID status. This study corroborates a high prevalence of ID in both HFrEF and HFpEF, and further shows that in patients with HFpEF there is a prolongation of LOS not seen in HFrEF which may indicate a more prominent role for ID in HFpEF.
Low Levels of Low-Density Lipoprotein Cholesterol and Mortality Outcomes in Non-Statin Users
Authors: Sung Ki-Chul , Huh Ji Hye , Ryu Seungho , Lee Jong-Young , Scorletti Eleonora , Byrne Christopher D , Kim Jang Young , Hyun Dae Sung , Ko Sang-Baek
Published: October 2019

We aimed to test the association between low-density lipoprotein cholesterol (LDL-C) and cardiovascular disease (CVD), cancer, and all-cause mortality in non-statin users. A total of 347,971 subjects in Kangbuk Samsung Health Study (KSHS.57.4% men, mean follow up: 5.64 ± 3.27 years) were tested. To validate these associations, we analyzed data from another cohort (Korean genome and epidemiology study, KoGES, 182,943 subjects). All subjects treated with any lipid-lowering therapy and who died during the first 3 years of follow up were excluded. Five groups were defined according to baseline LDL-C concentration (<70, 70–99, 100–129, 130–159, ≥160 mg/dL). A total of 2028 deaths occurred during follow-up in KSHS. The lowest LDL-C group (LDL < 70 mg/dL) had a higher risk of all-cause mortality (HR 1.95, 1.55–2.47), CVD mortality (HR 2.02, 1.11–3.64), and cancer mortality (HR 2.06, 1.46–2.90) compared to the reference group (LDL 120–139 mg/dL). In the validation cohort, 2338 deaths occurred during follow-up. The lowest LDL-C group (LDL < 70 mg/dL) had a higher risk of all-cause mortality (HR 1.81, 1.44–2.28) compared to the reference group. Low levels of LDL-C concentration are strongly and independently associated with increased risk of cancer, CVD, and all-cause mortality. These findings suggest that more attention is needed for subjects with no statin-induced decrease in LDL-C concentrations.
Long-Term Outcome and Rejection After Allogeneic Uterus Transplantation in Cynomolgus Macaques
Authors: Kisu Iori , Ishigaki Hirohito , Emoto Katsura , Kato Yojiro , Yamada Yohei , Matsubara Kentaro , Obara Hideaki , Masugi Yohei , Matoba Yusuke , Adachi Masataka , Banno Kouji , Saiki Yoko , Itagaki Iori , Kawamoto Ikuo , Iwatani Chizuru , Nakagawa Takahiro , Tsuchiya Hideaki , Sasamura Takako , Urano Hiroyuki , Ema Masatsugu , Ogasawara Kazumasa , Aoki Daisuke , Nakagawa Kenshi , Shiina Takashi
Published: October 2019

Uterus transplantation (UTx) is an option for women with uterine factor infertility to have a child, but is still in the experimental stage. Therefore, allogeneic animal models of UTx are required for resolution of clinical issues. In this study, long-term outcomes were evaluated in four recipients (cases 1–4) after allogeneic UTx in cynomolgus macaques. Immunosuppression with antithymocyte globulin induction and a triple maintenance regimen was used. Postoperative ultrasonography and biopsy of the transplanted uterus and immunoserological examinations were performed. All four recipients survived for >3 months after surgery, but continuous menstruation did not resume, although temporary menstruation occurred (cases 1 and 2). All animals were euthanized due to irreversible rejection and no uterine blood flow (cases 1, 2 and 4) and post-transplant lymphoproliferative disorder (case 3). Donor-specific antibodies against MHC class I and II were detected in cases 1, 2 and 4, but not in case 3. Peripheral lymphocyte counts tended to elevate for CD3+, CD20+ and NK cells in conjunction with uterine rejection, and all animals had elevated stimulation indexes of mixed lymphocyte reaction after surgery. Establishment of allogeneic UTx in cynomolgus macaque requires further exploration of immunosuppression, but the clinicopathological features of uterine rejection are useful for development of human UTx.
Pain Perception and Acceptance of Illness in Patients Undergoing Phacoemulsification Cataract Surgery under Drip Anesthesia
Authors: Kowalczuk Krystyna , Cybulski Mateusz , Cybulski Łukasz , Krajewska-Kułak Elżbieta
Published: October 2019

For many years, cataracts have been the main cause of vision loss and vision impairments in the world (43% and 33%, respectively). Currently, the most common surgical method for treating cataracts is phacoemulsification. The aim of this study was to assess the pain perception and acceptance of illness connected with awaiting phacoemulsification cataract surgery under intravenous drip anesthesia, as well as to determine the effect of selected sociodemographic factors on the above. Methods: The study was conducted in a group of patients of the Department of Ophthalmology, University Clinical Hospital in Białystok, Poland suffering from cataracts, who underwent phacoemulsification surgery under intravenous drip anesthesia. The study group consisted of 151 people. The study used an original short questionnaire and three standardized psychometric scales: The acceptance of illness scale (AIS), the Beliefs about Pain Control Questionnaire (BPCQ), and the Coping Strategies Questionnaire (CSQ). Results: The median overall AIS point value was 24 points, which is considered an average score in terms of disease acceptance. Respondents assessed the influence of individual factors on the level of perceived pain and the impact of individual strategies for coping with pain similarly. The level of perceived pain decreased with the patient’s age. People with a higher education level experienced a greater level of pain; however, this relationship was not statistically significant. The place of residence did not affect the level of pain experienced during the procedure. Women had a greater level of acceptance of illness. The respondents’ education level negligibly differentiated the approach to the disease. The place of residence also did not affect the assessment of illness acceptance as measured by the AIS. Whether the surgery pertained to the first or second eye did not significantly affect the approach to the disease. Conclusions: The level of acceptance of illness and pain perception were at a moderate level among the patients. The acceptance of illness was significantly influenced by the age of patients and the waiting period for phacoemulsification, and this level of acceptance decreased significantly with the increasing age of patients. The longer the waiting period for surgery, the lower the acceptance of illness. Sex significantly differentiated the level of pain experienced during the procedure. Education and place of residence did not significantly affect the acceptance of illness and the feeling of pain.
Growth Differentiation Factor-15 (GDF-15) Is a Biomarker of Muscle Wasting and Renal Dysfunction in Preoperative Cardiovascular Surgery Patients
Authors: Nakajima Toshiaki , Shibasaki Ikuko , Sawaguchi Tatsuya , Haruyama Akiko , Kaneda Hiroyuki , Nakajima Takafumi , Hasegawa Takaaki , Arikawa Takuo , Obi Syotaro , Sakuma Masashi , Ogawa Hironaga , Toyoda Shigeru , Nakamura Fumitaka , Abe Shichiro , Fukuda Hirotsugu , Inoue Teruo
Published: October 2019

Frailty and sarcopenia increase the risk of complications and mortality when invasive treatment such as cardiac surgery is performed. Growth differentiation factor-15 (GDF-15) involves various pathophysiological conditions including renal dysfunction, heart failure and cachexia. We investigated the pathophysiological roles of preoperative GDF-15 levels in cardiovascular surgery patients. Preoperative skeletal muscle index (SMI) determined by bioelectrical impedance analysis, hand-grip strength, 4 m gait speed, and anterior thigh muscle thickness (TMth) measured by echocardiography were assessed in 72 patients (average age 69.9 years) who underwent cardiovascular surgery. The preoperative serum GDF-15 concentration was determined by enzyme-linked immunosorbent assay. Circulating GDF-15 level was correlated with age, brain natriuretic peptide, and estimated glomerular filtration rate (eGFR). It was also negatively correlated with SMI, hand-grip strength, and anterior TMth. In multivariate analysis, eGFR and anterior TMth were the independent determinants of GDF-15 concentration even after adjusting for age, sex, and body mass index. Alternatively, the GDF-15 level was an independent determinant of eGFR and anterior TMth. We concluded that preoperative GDF-15 levels reflect muscle wasting as well as renal dysfunction in preoperative cardiovascular surgery patients. GDF-15 may be a novel biomarker for identify high-risk patients with muscle wasting and renal dysfunction before cardiovascular surgery.
Insights into Amyotrophic Lateral Sclerosis from a Machine Learning Perspective
Authors: Gordon Jonathan , Lerner Boaz
Published: October 2019

Objective: Amyotrophic lateral sclerosis (ALS) disease state prediction usually assumes linear progression and uses a classifier evaluated by its accuracy. Since disease progression is not linear, and the accuracy measurement cannot tell large from small prediction errors, we dispense with the linearity assumption and apply ordinal classification that accounts for error severity. In addition, we identify the most influential variables in predicting and explaining the disease. Furthermore, in contrast to conventional modeling of the patient’s total functionality, we also model separate patient functionalities (e.g., in walking or speaking). Methods: Using data from 3772 patients from the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) database, we introduce and train ordinal classifiers to predict patients’ disease state in their last clinic visit, while accounting differently for different error severities. We use feature-selection methods and the classifiers themselves to determine the most influential variables in predicting the disease from demographic, clinical, and laboratory data collected in either the first, last, or both clinic visits, and the Bayesian network classifier to identify interrelations among these variables and their relations with the disease state. We apply these methods to model each of the patient functionalities. Results: We show the error distribution in ALS state prediction and demonstrate that ordinal classifiers outperform classifiers that do not account for error severity. We identify clinical and lab test variables influential to prediction of different ALS functionalities and their interrelations, and specific value combinations of these variables that occur more frequently in patients with severe deterioration than in patients with mild deterioration and vice versa. Conclusions: Ordinal classification of ALS state is superior to conventional classification. Identification of influential ALS variables and their interrelations help explain disease mechanism. Modeling of patient functionalities separately allows relation of variables and their connections to different aspects of the disease as may be expressed in different body segments.
Electrochemical Study of a Hybrid Polymethyl Methacrylate Coating using SiO2 Nanoparticles toward the Mitigation of the Corrosion in Marine Environments
Authors: Maya-Cornejo José , Rodríguez-Gómez Francisco J. , Molina Gustavo A. , Galindo-de-la-Rosa Juan , Ledesma-García Janet , Hernández-Martínez Ángel R. , Esparza Rodrigo , Pérez Ramiro , Estévez Miriam
Published: October 2019

The demand for hydrophobic polymer-based protective coatings to impart high corrosion resistance has increased recently. The increase of the hydrophobicity in a hybrid coating is a new challenge, for that reason and in order to protect a metallic surface of oxidant agents, a poly (methyl methacrylate) (PMMA) coating with the addition of a different amount of silicon dioxide (SiO2) was developed. The hybrid coating was applied on a sample of stainless steel AISI 304 by the dip-coating method. The characterization of the coatings was determined by electrochemical impedance spectroscopy and with a scanning electrochemical microscopy. The best coatings were PMMA and PMMA + SiO2 0.01% that exhibits a real impedance in the Nyquist diagram of 760 and 427,800 MΩ⋅cm2, respectively, and the modulus of the real impedance in the Bode diagram present values of 2.2 × 108 and 3.3 × 108 Ω⋅cm2. Moreover, the phase angle presents constant values around 75° to 85° and 85° for the PMMA and PMMA + SiO2 0.01%, respectively. Moreover, the values of the real resistance for the PMMA + SiO2 0.01% coating present values in the order of Mega-ohms despite the coating exhibits an artificial defect in their surface. The contact angle test showed that the hydrophobicity of the hybrid PMMA + SiO2 0.01% coating is higher than that of the pure PMMA coatings. The hybrid PMMA + SiO2 coatings developed in this work are a very interesting and promising area of study in order to develop efficient products to protect metallic surfaces from corrosion phenomenon.
Ab Initio Study of Ternary W5Si3 Type TM5Sn2X Compounds (TM = Nb, Ti and X = Al, Si)
Authors: Papadimitriou Ioannis , Utton Claire , Tsakiropoulos Panos
Published: October 2019

The adhesion of the scale formed on Nb-silicide based alloys at 1473 K improves when Al and Sn are in synergy with Si and Ti. This improvement is observed when there is segregation of Sn in the microstructure below the alloy/scale interface and a layer rich in intermetallics that include TM5Sn2X compounds is formed at the interface. Data for the ternary compounds is scarce. In this paper elastic and thermodynamic properties of the Nb5Sn2Al, Ti5Sn2Si, Ti5Sn2Al and Nb5Sn2Si compounds were studied using the first-principles, pseudopotential plane-wave method based on density functional theory. The enthalpy of formation of the ternary intermetallics was calculated using the quasi-harmonic approximation. The calculations suggest that the Nb5Sn2Si is the stiffest; that the Nb5Sn2Al and Ti5Sn2Si are the most and less ductile phases respectively; and that Nb significantly increases the bulk, shear and elastic moduli of the ternary compound compared with Ti.
Optical Properties, Morphology, and Stability of Iodide-Passivated Lead Sulfide Quantum Dots
Authors: Skurlov Ivan D. , Korzhenevskii Iurii G. , Mudrak Anastasiia S. , Dubavik Aliaksei , Cherevkov Sergei A. , Parfenov Petr S. , Zhang Xiaoyu , Fedorov Anatoly V. , Litvin Aleksandr P. , Baranov Alexander V.
Published: October 2019

Iodide atomic surface passivation of lead chalcogenides has spawned a race in efficiency of quantum dot (QD)-based optoelectronic devices. Further development of QD applications requires a deeper understanding of the passivation mechanisms. In the first part of the current study, we compare optics and electrophysical properties of lead sulfide (PbS) QDs with iodine ligands, obtained from different iodine sources. Methylammonium iodide (MAI), lead iodide (PbI2), and tetrabutylammonium iodide (TBAI) were used as iodine precursors. Using ultraviolet photoelectron spectroscopy, we show that different iodide sources change the QD HOMO/LUMO levels, allowing their fine tuning. AFM measurements suggest that colloidally-passivated QDs result in formation of more uniform thin films in one-step deposition. The second part of this paper is devoted to the PbS QDs with colloidally-exchanged shells (i.e., made from MAI and PbI2). We especially focus on QD optical properties and their stability during storage in ambient conditions. Colloidal lead iodide treatment is found to reduce the QD film resistivity and improve photoluminescence quantum yield (PLQY). At the same time stability of such QDs is reduced. MAI-treated QDs are found to be more stable in the ambient conditions but tend to agglomerate, which leads to undesirable changes in their optics.
The Relationship between Residual Amount of Sr and Morphology of Eutectic Si Phase in A356 Alloy
Authors: Zhang Wenda , Ma Shixuan , Wei Zhenhua , Bai Peikang
Published: October 2019

This paper studied the relationship between the residual amount of Sr and the morphology of the eutectic Si phase in A356 obtained through different modification treatment processes; additionally, the cooling rates of molds were studied. The eutectic Si phase revealed a satisfactory modification effect at residual Sr amounts above 0.01 wt % in A356 alloys cast using an iron mould. Complete modification of the eutectic Si phase could be achieved at a Sr additive amount 0.03 wt % in an A356 melt. The addition of higher amounts of Sr (~0.04–0.06 wt %) did not improve the modification effect. With the addition of 0.06 wt % Sr into A356 alloy melt and holding at 750 °C, the anti-fading capacity of Sr modification effect could be sustained for 120 minutes. More Sr is needed to obtain a good modification of eutectic Si for an A356 alloy cast using a sand mold.
Topological Design of a Lightweight Sandwich Aircraft Spoiler
Authors: Liu Jie , Ou Haifeng , He Junfeng , Wen Guilin
Published: October 2019

In this study, a lightweight sandwich aircraft spoiler (AS) with a high stiffness-to-weight ratio was designed. Excellent mechanical properties were achieved by the synthetic use of topology optimization (TO), lattice structure techniques, and high-performance materials, i.e., titanium alloy and aluminum alloy. TO was first utilized to optimize the traditional aircraft spoiler to search for the stiffest structure with a limited material volume, where titanium alloy and aluminum alloy were used for key joints and other parts of the AS, respectively. We then empirically replaced the fine features inside the optimized AS with 3D kagome lattices to support the shell, resulting in a lightweight sandwich AS. Numerical simulations were conducted to show that the designed sandwich AS exhibited good mechanical properties, e.g., high bending rigidity, with a reduction in weight by approximately 80% when compared with that of the initial design model. Finally, we fabricated the designed model with photosensitive resin using a 3D printing technique.
Thermo-Mechanical Fatigue Lifetime Assessment of Spheroidal Cast Iron at Different Thermal Constraint Levels
Authors: Ghodrat Sepideh , Kalra Aakarshit , Kestens Leo A.I. , Riemslag Ton (A.C.)
Published: October 2019

In previous work on the thermo-mechanical fatigue (TMF) of compacted graphite iron (CGI), lifetimes measured under total constraint were confirmed analytically by numerical integration of Paris’ crack-growth law. In current work, the results for CGI are further validated for spheroidal cast iron (SGI), while TMF tests at different constraint levels were additionally performed. The Paris crack-growth law is found to require a different C P a r i s parameter value per distinct constraint level, indicating that Paris’ law does not capture all physical backgrounds of TMF crack growth, such as the effect of constraint level. An adapted version of Paris’ law is developed, designated as the local strain model. The new model considers cyclic plastic strains at the crack tip to control crack growth and is found to predict TMF lifetimes of SGI very well for all constraint levels with a single set of parameters. This includes not only full constraint but also over and partial constraint conditions, as encountered in diesel engine service conditions. The local strain model considers the crack tip to experience a distinct sharpening and blunting stage during each TMF cycle, with separate contributions to crack-tip plasticity, originating from cyclic bulk stresses in the sharpening stage and cyclic plastic bulk strains in the blunting stage.
Flaw Detection in Aluminum Plates Using a Rotating Uniform Eddy Current Probe with Two Pairs of Excitation Coils
Authors: Repelianto Ageng S. , Kasai Naoya , Sekino Kouichi , Matsunaga Masaki , Trung Le Q.
Published: October 2019

The use of eddy currents for detecting flaws in specimens is of considerable significance in the industrial sector. In this study, a new design of a rotating uniform eddy current (UEC) probe, termed the rotating butterfly probe, is presented. The probe consists of two pairs of excitation coils arranged perpendicular to each other, positioned in two layers, and in a detection coil. The excitation and detection coils were installed the pancake orientation, which provides larger induction and enhances the sensitivity of flaws detection. In addition, to generate a rotating UEC distribution with same amplitude in all directions, the number of turns between first and second layers of the excitation coils and the amplitude of excitation current were arranged. Finite element simulations were conducted to confirm that rotating UEC distribution has the same amplitude in all directions. The experiment with the rotating butterfly probe was then conducted. In the experiment, the measured results with the probe was indicated the self-differential and self-nulling properties. Moreover, the probe was successful in detecting flaws in all directions on an aluminum plate. This attribute can be used for the effective inspection of test pieces.
Chemical Stability of Zirconolite for Proliferation Resistance under Conditions Typically Required for the Leaching of Highly Refractory Uranium Minerals
Authors: Nikoloski Aleksandar N. , Gilligan Rorie , Squire Jonathan , Maddrell Ewan R.
Published: October 2019

In this study, synthetic zirconolite samples with a target composition Ca0.75Ce0.25ZrTi2O7, prepared using two different methods, were used to study the stability of zirconolite for nuclear waste immobilisation. Particular focus was on plutonium, with cerium used as a substitute. The testing of destabilisation was conducted under conditions previously applied to other highly refractory uranium minerals that have been considered for safe storage of nuclear waste, brannerite and betafite. Acid (HCl, H2SO4) leaching for up to 5 h and alkaline (NaHCO₃, Na2CO3) leaching for up to 24 h was done to enable comparison with brannerite leached under the same conditions. Ferric ion was added as an oxidant. Under these conditions, the synthetic zirconolite dissolved much slower than brannerite and betafite. While the most intense conditions were observed previously to result in near complete dissolution of brannerite in under 5 h, zirconolite was not observed to undergo significant attack over this timescale. Fine zirconolite dissolved faster than the coarse material, indicating that dissolution rate is related to surface area. This data and the long term stability of zirconolite indicate that it is a good material for long-term sequestration of radioisotopes. Besides its long term durability in the disposal environment, a wasteform for fissile material immobilisation must demonstrate proliferation resistance such that the fissile elements cannot be retrieved by leaching of the wasteform. This study, in conjunction with the previous studies on brannerite and betafite leaching, strongly indicates that the addition of depleted uranium to the wasteform, to avert long term criticality events, is detrimental to proliferation resistance. Given the demonstrated durability of zirconolite, long term criticality risks in the disposal environment seem a remote possibility, which supports its selection, above brannerite or betafite, as the optimal wasteform for the disposition of nuclear waste, including of surplus plutonium.
Atom Probe Tomography of Aluminium Alloys: A Systematic Meta-Analysis Review of 2018
Authors: Ceguerra Anna V. , Marceau Ross K.W.
Published: October 2019

Atom probe tomography (APT) is a microscopy technique that provides a unique combination of information, specifically the position and elemental identity of each atom in three dimensions. Although the mass and spatial resolution is not perfect, we are still able to gain insights into materials science questions that we cannot access using other techniques. This systematic meta-analysis review summarises research in 2018 that used APT to study materials science questions in aluminium alloys.
Effect of Si Addition on Mechanical and Electrochemical Properties of Al-Fe-Cu-La Alloy for Current Collector of Lithium Battery
Authors: Xu Yawu , Ding Dongyan , Yang Xin , Zhang Wenlong , Gao Yongjin , Wu Zhanlin , Chen Guozhen , Chen Renzong , Huang Yuanwei , Tang Jinsong
Published: October 2019

The increasing demand for high-performance current collectors of lithium ion secondary batteries requires that the employed aluminum alloys have better mechanical properties and superior electrochemical performance. The effect of Si addition on the microstructure, tensile and electrochemical performance of Al-Fe-Cu-La alloy was investigated by optical microscopy, X-ray diffraction, scanning electron microscopy, a tensile test, conductivity test and Tafel polarization curve test. Experimental results indicated that Si addition to the Al-Fe-Cu-La alloy helped to refine the longitudinal grain size of the alloy. The Si-containing phase (AlFeSi) nucleated and grew along the surface of the AlFeLa phase. The Si addition to the Al-Fe-Cu-La alloy could greatly increase the tensile strength in the temperature range of −20 °C to 50 °C and improve high temperature stability of the alloy. Also, the addition of Si promoted the formation of the AlFeSi ternary phase, which helped to improve the corrosion resistance of the alloy.
Ore Geology, Fluid Inclusion Microthermometry and H-O-S Isotopes of the Liyuan Gold Deposit, Central Taihang Mountains, North China Craton
Authors: Zhu Xiaoqiang , Wang Jingbin , Pang Zhenshan , Zhen Shimin , Yang Fan , Xue Jianling , Jia Hongxiang , Shi Guangyao
Published: October 2019

The Liyuan gold deposit, located in the central Taihang Mountains, North China Craton, forms an important part of the Taihang polymetallogenic belt. The origin of ore-forming fluids and the genesis of this deposit remains controversial. In this paper, fluid inclusions (FIs) microthermometry and H-O-S isotopes analysis are conducted to constrain the origin of ore-forming fluids and genesis. The main findings are as follows: (1) Three hydrothermal metallogenic stages are identified: Quartz–pyrite, quartz–polymetallic sulfide, and quartz–carbonate stages; (2) three types of primary FIs are recognized: CO2-aqueous (type I), pure CO2 (type II), and aqueous FIs (type III); (3) ore-forming fluids are characterized by medium–low temperatures, medium–low salinity, and H2O-CO2-NaCl ± CH4 system; (4) H-O isotopes indicate that the ore-forming fluids mainly have a magmatic origin and late-stage ore fluids mixed with meteoric water; (5) S isotopes further confirm that the sulfides most likely have a deep magma source with variation caused by changes in oxygen fugacity; and (6) fluid immiscibility and water–rock interactions are considered to be the two main mechanisms of gold deposition. Due to the lack of large granite bodies exposed in this ore district, we infer that the fluids of gold deposit and quartz porphyry may have both been exsolved from a concealed granite pluton at deeper locations, and we further propose that Liyuan gold deposit is typical magmatic–hydrothermal gold deposits.
The Synthesis of NiCo2O4–MnO2 Core–Shell Nanowires by Electrodeposition and Its Supercapacitive Properties
Authors: Yan Ai-Lan , Wang Wei-Dong , Chen Wen-Qiang , Wang Xin-Chang , Liu Fu , Cheng Ji-Peng
Published: October 2019

Hierarchical composite films grown on current collectors are popularly reported to be directly used as electrodes for supercapacitors. Highly dense and conductive NiCo2O4 nanowires are ideal backbones to support guest materials. In this work, low crystalline MnO2 nanoflakes are electrodeposited onto the surface of NiCo2O4 nanowire films pre-coated on nickel foam. Each building block in the composite films is a NiCo2O4–MnO2 core–shell nanowire on conductive nickel foam. Due to the co-presence of MnO2 and NiCo2O4, the MnO2@NiCo2O4@Ni electrode exhibits higher specific capacitance and larger working voltage than the NiCo2O4@Ni electrode. It can have a high specific capacitance of 1186 F·g−1 at 1 A·g−1. When the core–shell NiCo2O4–MnO2 composite and activated carbon are assembled as a hybrid capacitor, it has the highest energy density of 29.6 Wh·kg−1 at a power density of 425 W·kg−1 with an operating voltage of 1.7 V. This work shows readers an easy method to synthesize composite films for energy storage.
A Hydrothermal-Assisted Ball Milling Approach for Scalable Production of High-Quality Functionalized MoS2 Nanosheets for Polymer Nanocomposites
Authors: Ahmadi Mojtaba , Zabihi Omid , Li Quanxiang , Fakhrhoseini Seyed Mousa , Naebe Minoo
Published: October 2019

The most known analogue of graphene, molybdenum disulfide (MoS2) nanosheet, has recently captured great interest because it can present properties beyond graphene in several high technological applications. Nonetheless, the lack of a feasible, sustainable, and scalable approach, in which synthesizing and functionalization of 2H-MoS2 nanosheets occur simultaneously, is still a challenge. Herein, a hydrothermal treatment has been utilised to reduce the effect of breaking mechanisms on the lateral size of produced nanosheets during the ball milling process. It was demonstrated that the hydrothermal pre-treatment led to the initial intercalation of an organic molecule such as 4,4′-diaminodiphenyl sulfone (DDS) within the stacked MoS2 sheets. Such a phenomenon can promote the horizontal shear forces and cause sliding and peeling mechanisms to be the dominated ones during low energy ball milling. Such combined methods can result in the production of 2H functionalized MoS2 nanosheets. The resultant few layers showed an average lateral dimension of more than 640 nm with the thickness as low as ~6 nm and a surface area as high as ~121.8 m2/g. These features of the synthesised MoS2 nanosheets, alongside their functional groups, can result in fully harnessing the reinforcing potential of MoS2 nanosheets for improvement of mechanical properties in different types of polymeric matrices.
A Prospective Study Evaluating the Effects of a Nutritional Supplement Intervention on Cognition, Mood States, and Mental Performance in Video Gamers
Authors: Tartar Jaime L. , Kalman Douglas , Hewlings Susan
Published: October 2019

Cognitive function is critical for successful prolonged performance in eSports. This double-blind placebo-controlled study examined the effect of an inositol-enhanced arginine silicate oral supplement on cognitive performance and energy in eSports athletes. Sixty healthy men and women who spent 5 or more hours a week playing video games were randomly assigned to take supplement or placebo for 7 days. On day 1 and 7, before and 15 min after dosing, subjects completed the Trail Making Test (TMT), Parts A and B; Stroop Test; and Profile of Mood States (POMS) questionnaire, and then played a video game for 60 min. Immediately after, cognitive tests were repeated. Self-reported energy levels increased, anger decreased, and TMT-B test errors decreased in the supplement group compared to placebo (p < 0.05). Fatigue, TMT-B time, and TMT B-A score improved in the supplement group compared to baseline (p < 0.05). After 60 min of gaming, supplementation decreased Stroop Test errors and TMT-A time (p < 0.05). Adverse events were minimal and not different between groups. These data appear to support the use of the studies product (nooLVL®) in eSports gamers looking to improve their accuracy, decision making, and reaction time during gaming.
Combining Mechanistic Modeling and Raman Spectroscopy for Monitoring Antibody Chromatographic Purification
Authors: Feidl Fabian , Garbellini Simone , Luna Martin F. , Vogg Sebastian , Souquet Jonathan , Broly Hervé , Morbidelli Massimo , Butté Alessandro
Published: October 2019

Chromatography is widely used in biotherapeutics manufacturing, and the corresponding underlying mechanisms are well understood. To enable process control and automation, spectroscopic techniques are very convenient as on-line sensors, but their application is often limited by their sensitivity. In this work, we investigate the implementation of Raman spectroscopy to monitor monoclonal antibody (mAb) breakthrough (BT) curves in chromatographic operations with a low titer harvest. A state estimation procedure is developed by combining information coming from a lumped kinetic model (LKM) and a Raman analyzer in the frame of an extended Kalman filter approach (EKF). A comparison with suitable experimental data shows that this approach allows for the obtainment of reliable estimates of antibody concentrations with reduced noise and increased robustness.
The Multisensor Array Based on Grown-On-Chip Zinc Oxide Nanorod Network for Selective Discrimination of Alcohol Vapors at Sub-ppm Range
Authors: Bobkov Anton , Varezhnikov Alexey , Plugin Ilya , Fedorov Fedor S. , Trouillet Vanessa , Geckle Udo , Sommer Martin , Goffman Vladimir , Moshnikov Vyacheslav , Sysoev Victor
Published: October 2019

We discuss the fabrication of gas-analytical multisensor arrays based on ZnO nanorods grown via a hydrothermal route directly on a multielectrode chip. The protocol to deposit the nanorods over the chip includes the primary formation of ZnO nano-clusters over the surface and secondly the oxide hydrothermal growth in a solution that facilitates the appearance of ZnO nanorods in the high aspect ratio which comprise a network. We have tested the proof-of-concept prototype of the ZnO nanorod network-based chip heated up to 400 °C versus three alcohol vapors, ethanol, isopropanol and butanol, at approx. 0.2–5 ppm concentrations when mixed with dry air. The results indicate that the developed chip is highly sensitive to these analytes with a detection limit down to the sub-ppm range. Due to the pristine differences in ZnO nanorod network density the chip yields a vector signal which enables the discrimination of various alcohols at a reasonable degree via processing by linear discriminant analysis even at a sub-ppm concentration range suitable for practical applications.