bluuebunny/crossref_metadata_2025 huggingface dataset:
DispHred: A Server to Predict pH-Dependent Order–Disorder Transitions in Intrinsically Disordered Proteins
Authors: Santos Jaime , Iglesias Valentín , Pintado Carlos , Santos-Suárez Juan , Ventura Salvador
Published: August 2020

The natively unfolded nature of intrinsically disordered proteins (IDPs) relies on several physicochemical principles, of which the balance between a low sequence hydrophobicity and a high net charge appears to be critical. Under this premise, it is well-known that disordered proteins populate a defined region of the charge–hydropathy (C–H) space and that a linear boundary condition is sufficient to distinguish between folded and disordered proteins, an approach widely applied for the prediction of protein disorder. Nevertheless, it is evident that the C–H relation of a protein is not unalterable but can be modulated by factors extrinsic to its sequence. Here, we applied a C–H-based analysis to develop a computational approach that evaluates sequence disorder as a function of pH, assuming that both protein net charge and hydrophobicity are dependent on pH solution. On that basis, we developed DispHred, the first pH-dependent predictor of protein disorder. Despite its simplicity, DispHred displays very high accuracy in identifying pH-induced order/disorder protein transitions. DispHred might be useful for diverse applications, from the analysis of conditionally disordered segments to the synthetic design of disorder tags for biotechnological applications. Importantly, since many disorder predictors use hydrophobicity as an input, the here developed framework can be implemented in other state-of-the-art algorithms.
N6-(2-hydroxyethyl)-Adenosine Induces Apoptosis via ER Stress and Autophagy of Gastric Carcinoma Cells In Vitro and In Vivo
Authors: Xie Hongqing , Li Xiaotong , Yang Weiwei , Yu Liping , Jiang Xiasen , Chen Yajie , Shen Zhangfei , Li Conghui , Gu Meier , Shi Liangen
Published: August 2020

Gastric cancer is the most common malignant tumor of the digestive tract and is great challenge in clinical treatment. N6-(2-Hydroxyethyl)-adenosine (HEA), widely present in various fungi, is a natural adenosine derivative with many biological and pharmacological activities. Here, we assessed the antineoplastic effect of HEA on gastric carcinoma. HEA exerted cytotoxic effects against gastric carcinoma cells (SGC-7901 and AGS) in a dose and time-dependent manner. Additionally, we found that HEA induced reactive oxygen species production and mitochondrial membrane potential depolarization. Moreover, it could trigger caspase-dependent apoptosis, promoting intracellular Ca2+-related endoplasmic reticulum (ER) stress and autophagy. On the other hand, HEA could significantly inhibit the growth of transplanted tumors in nude mice and induce apoptosis of tumor tissues cells in vivo. In conclusion, HEA induced apoptosis of gastric carcinoma cells in vitro and in vivo, demonstrating that HEA is a potential chemotherapeutic agent for gastric carcinoma.
Suppression of SHROOM1 Improves In Vitro and In Vivo Gene Integration by Promoting Homology-Directed Repair
Authors: Zhao Zhihua , Zhang Hanshuo , Xiong Tuanlin , Wang Junyi , Yang Di , Zhu Dan , Li Juan , Yang Ye , Sun Changhong , Zhao Yuting , Xi Jianzhong Jeff
Published: August 2020

Homologous recombination (HR) is often used to achieve targeted gene integration because of its higher precision and operability compared with microhomology-mediated end-joining (MMEJ) or non-homologous end-joining (NHEJ). It appears to be inefficient for gene integration in animal cells and embryos due to occurring only during cell division. Here we developed genome-wide high-throughput screening and a subsequently paired crRNA library screening to search for genes suppressing homology-directed repair (HDR). We found that, in the reporter system, HDR cells with knockdown of SHROOM1 were enriched as much as 4.7-fold than those with control. Down regulating SHROOM1 significantly promoted gene integration in human and mouse cells after cleavage by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9), regardless of the donor types. The knock-in efficiency of mouse embryos could also be doubled by the application of SHROOM1 siRNA during micro-injection. The increased HDR efficiency of SHROOM1 deletion in HEK293T cells could be counteracted by YU238259, an HDR inhibitor, but not by an NHEJ inhibitor. These results indicated that SHROOM1 was an HDR-suppressed gene and that the SHROOM1 knockdown strategy may be useful for a variety of applications, including gene editing to generate cell lines and animal models for studying gene function and human diseases.
Increased miR-7641 Levels in Peritoneal Hyalinizing Vasculopathy in Long-Term Peritoneal Dialysis Patients
Authors: Díaz Raquel , Sandoval Pilar , Rodrigues-Diez Raul R. , del Peso Gloria , Jiménez-Heffernan José A , Ramos-Ruíz Ricardo , Llorens Carlos , Laham Gustavo , Alvarez-Quiroga Mabel , López-Cabrera Manuel , Ruiz-Ortega Marta , Bajo María A. , Selgas Rafael
Published: August 2020

Peritoneal hyalinizing vasculopathy (PHV) represents the cornerstone of long-term peritoneal dialysis (PD), and especially characterizes patients associated with encapsulating peritoneal sclerosis. However, the mechanisms of PHV development remain unknown. A cross sectional study was performed in 100 non-selected peritoneal biopsies of PD patients. Clinical data were collected and lesions were evaluated by immunohistochemistry. In selected biopsies a microRNA (miRNA)-sequencing analysis was performed. Only fifteen patients (15%) showed PHV at different degrees. PHV prevalence was significantly lower among patients using PD fluids containing low glucose degradation products (GDP) (5.9% vs. 24.5%), angiotensin converting enzyme inhibitors (ACEIs) (7.5% vs. 23.4%), statins (6.5% vs. 22.6%) or presenting residual renal function, suggesting the existence of several PHV protective factors. Peritoneal biopsies from PHV samples showed loss of endothelial markers and induction of mesenchymal proteins, associated with collagen IV accumulation and wide reduplication of the basement membrane. Moreover, co-expression of endothelial and mesenchymal markers, as well as TGF-β1/Smad3 signaling activation were found in PHV biopsies. These findings suggest that an endothelial-to-mesenchymal transition (EndMT) process was taking place. Additionally, significantly higher levels of miR-7641 were observed in severe PHV compared to non-PHV peritoneal biopsies. Peritoneal damage by GDPs induce miRNA deregulation and an EndMT process in submesothelial vessels, which could contribute to collagen IV accumulation and PHV.
Knockout of the Transducin-Like Enhancer of Split 6 Gene Affects the Proliferation and Cell Cycle Process of Mouse Spermatogonia
Authors: Feng Meiying , Bai Yinshan , Chen Yun , Wang Kai
Published: August 2020

Tle6 (Transducin-like enhancer of split 6) is a member of the Tle co-repressor superfamily, which is expressed in various tissues of invertebrates and vertebrates and participates in the developmental process. However, the current research has only found that the TLE6 mutation is related to infertility, and the key regulatory mechanism of TLE6 remains to be explored. In this study, we combined Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9 and the Tet-on system to construct mouse spermatogonia cell lines that induced TLE6 protein knockout (KO), and studied the effect of Tle6 on mouse spermatogonia proliferation and the cell cycle. The results showed that, after drug induction, the Tle6 gene in mouse spermatogonia was successfully knocked out at the genome and protein levels, and the Tle6 gene knockout efficiency was confirmed to be 87.5% with gene-cloning technology. At the same time, we also found that the mouse spermatogonia proliferated slowly after the Tle6 knockout. Using flow cytometry, we found that the cells did not undergo significant apoptosis, and the number of cells in the S phase decreased. After real-time quantity PCR (qRT-PCR) analysis, we found that the expression of cell-proliferation-related genes, CCAAT enhancer-binding protein α(C/ebp α), granulocyte-colony stimulating factor(G-csf), cyclin-dependent kinases 4(Cdk 4), Cyclin E, proliferating cell nuclear antigen(Pcna), and S-phase kinase-associated protein 2 (Skp2) was significantly reduced, which further affected cell growth. In summary, Tle6 can regulate spermatogonia cell proliferation and the cell cycle and provide a scientific basis for studying the role of TLE6 on spermatogenesis.
Can the Isothermal Calorimetric Curve Shapes Suggest the Structural Changes in Micellar Aggregates?
Authors: Łudzik Katarzyna , Woloszczuk Sebastian , Zając Wojciech , Jazdzewska Monika , Rogachev Andrey , Kuklin Alexander Ivanowicz , Zawisza Anna , Jóźwiak Małgorzata
Published: August 2020

Inspired by the unusual shapes of the titration curve observed for many surfactants and mixed colloidal systems, we decided to extend the analysis to isothermal titration calorimetric curves (ITC) by paying special attention to potential structural changes in micellar aggregates. In this paper, we used isothermal titration calorimetry in conjunction with Scanning Transmission Electron Microscopy (STEM), Small-Angle Neutron Scattering (SANS) and X-ray Scattering (SAXS) methods support by Monte Carlo and semiempirical quantum chemistry simulations to confirm if the isothermal calorimetric curve shape can reflect micelle transition phenomena. For that purpose, we analysed, from the thermodynamic point of view, a group of cationic gemini surfactants, alkanediyl-α,ω-bis(dimethylalkylammonium) bromides. We proposed the shape of aggregates created by surfactant molecules in aqueous solutions and changes thereof within a wide temperature range. The results provide evidence for the reorganization processes and the relationship (dependence) between the morphology of the created aggregates and the conditions such as temperature, surfactant concentration and spacer chain length which affect the processes.
The Longevity of Colonies of Fungus-Growing Termites and the Stability of the Symbiosis
Authors: Wisselink Margo , Aanen Duur K. , van ’t Padje Anouk
Published: August 2020

The agricultural mutualistic symbiosis between macrotermitine termites and Termitomyces fungi is obligate for both partners. The termites provide a protective growth environment for the fungus by cultivating it inside their colony and providing it with foraged plant material. The termites use the fungus for plant substrate degradation, and the production of asexual fruiting bodies for nourishment and re-inoculation of the fungus garden. The termite colony can reach an age of up to several decades, during which time it is believed that a single fungal monoculture is asexually propagated by the offspring of a single founding royal pair. The termite-fungus mutualism has a long evolutionary history dating back more than 30 million years. Both on the time-scale of a termite colony lifespan and that of the mutualistic symbiosis, questions arise about stability. We address the physical stability of the mound, the termite colony and the monoculture fungal garden during a colony’s lifetime. On the long-term evolutionary scale, we address the stability of the symbiosis, where horizontal transmission of the symbiotic fungus raises the question of how the mutualistic interaction between host and symbiont persists over generations.
High Endothelial Venule with Concomitant High CD8+ Tumor-Infiltrating Lymphocytes Is Associated with a Favorable Prognosis in Resected Gastric Cancer
Authors: Hong Soon Auck , Hwang Hye Won , Kim Min Kyoon , Lee Tae Jin , Yim Kwangil , Won Hye Sung , Sun Der Sheng , Kim Eun Young , Ko Yoon Ho
Published: August 2020

CD8+ tumor-infiltrating lymphocytes (TILs) play a major role in antitumor immunity. High endothelial venules (HEVs) are related to diverse immune cells in solid tumors. We analyzed CD8+ and Foxp3+ TILs in combination with HEVs to determine their prognostic role in advanced gastric cancer (AGC). We enrolled 157 patients with AGC in this study. The densities of CD8+ TILs and Foxp3+ TILs were calculated using immunohistochemical staining. HEVs were evaluated by MECA-79 expression. HEVs were identified in 60 (38.2%) cases and was significantly associated with an increased number of CD8+ TILs (p = 0.027) but not of Foxp3+ TILs (p = 0.455) and CD20+ TILs (p = 0.163). A high CD8+/HEV+ level was significantly associated with nodal metastasis (p = 0.048). In survival analysis, patients with high CD8+/HEV+ levels demonstrated the longest overall survival (OS) (p = 0.015). Furthermore, a high CD8+/HEV+ level was an independent prognostic factor in AGC (p = 0.011; hazard ratio (HR) = 0.435; 95% confidence interval (CI) = 0.245–0.837). HEVs were found to play an important role in antitumor immunity associated with CD8+ TILs in AGC. This analysis of HEVs and CD8+ TILs helps stratify patients with AGC and sheds light on tumor immunity.
Nafamostat Mesylate Improved Survival Outcomes of Sepsis Patients Who Underwent Blood Purification: A Nationwide Registry Study in Japan
Authors: Kamijo Hiroshi , Mochizuki Katsunori , Nakamura Yuta , Mori Kotaro , Ichikawa Michitaro , Nitta Kenichi , Imamura Hiroshi
Published: August 2020

Nafamostat mesylate (NM) is a synthetic serine protease inhibitor that can be used as an anticoagulant during blood purification in critically ill patients, as well as a treatment for disseminated intravascular coagulation. Although NM has been reported to reduce the risk of bleeding during blood purification, its effect on survival outcomes of patients who received blood purification treatments is unclear. We hypothesized that administration of NM during blood purification can reduce mortality in patients with sepsis. A post hoc analysis was conducted on a nationwide retrospective registry that included data from 3195 sepsis patients registered at 42 intensive care units throughout Japan. We evaluated the effect of NM on hospital mortality and bleeding complications using propensity score matching in 1216 sepsis patients who underwent blood purification in the intensive care unit (ICU). Two-hundred-and-sixty-eight pairs of propensity score-matched patients who received NM and conventional therapy were compared. Hospital and ICU mortality rates in the NM group were significantly lower than those in the conventional therapy group. However, rates of bleeding complications did not differ significantly between the two groups. These data suggest that administration of NM improved the survival outcomes of sepsis patients who underwent blood purification in the ICU.
Erratum: Mina, R.; et al. Minimal Residual Disease in Multiple Myeloma: State of the Art and Future Perspectives. J. Clin. Med. 2020, 9, 2142
Authors: Mina Roberto , Oliva Stefania , Boccadoro Mario
Published: August 2020

The authors sincerely apologize for the inaccuracies made during the revision that a product line has been associated with the wrong company [...]
Effect of Type 2 Diabetes Mellitus on the Hypoxia-Inducible Factor 1-Alpha Expression. Is There a Relationship with the Clock Genes?
Authors: López-Cano Carolina , Gutiérrez-Carrasquilla Liliana , Barbé Ferran , Sánchez Enric , Hernández Marta , Martí Raquel , Ceperuelo-Mallafre Vicky , Dalmases Mireia , Fernández-Veledo Sonia , Vendrell Joan , Hernández Cristina , Simó Rafael , Lecube Albert
Published: August 2020

Limited reports exist on the relationships between regulation of oxygen homeostasis and circadian clock genes in type 2 diabetes. We examined whether the expression of Hypoxia-Inducible Factor-1α (HIF-1α) and HIF-2α relates to changes in the expression of clock genes (Period homolog proteins (PER)1, PER2, PER3, Retinoid-related orphan receptor alpha (RORA), Aryl hydrocarbon receptor nuclear translocator-like protein 1 (ARNTL), Circadian locomotor output cycles kaput (CLOCK), and Cryptochrome proteins (CRY) 1 and CRY2) in patients with type 2 diabetes. A total of 129 subjects were evaluated in this cross-sectional study (48% with diabetes). The gene expression was measured by polymerase chain reaction. The lactate and pyruvate levels were used as surrogate of the hypoxia induced anaerobic glycolysis activity. Patients with diabetes showed an increased plasma concentration of both lactate (2102.1 ± 688.2 vs. 1730.4 ± 694.4 uM/L, p = 0.013) and pyruvate (61.9 ± 25.6 vs. 50.3 ± 23.1 uM/L, p = 0.026) in comparison to controls. However, this finding was accompanied by a blunted HIF-1α expression (1.1 (0.2 to 5.0) vs. 1.7 (0.4 to 9.2) arbitrary units (AU), p ≤ 0.001). Patients with diabetes also showed a significant reduction of all assessed clock genes’ expression. Univariate analysis showed that HIF-1α and almost all clock genes were significantly and negatively correlated with HbA1c concentration. In addition, positive correlations between HIF-1α and the clock genes were observed. The stepwise multivariate regression analysis showed that HbA1c and clock genes independently predicted the expression of HIF-1α. Type 2 diabetes modifies the expression of HIF-1α and clock genes, which correlates with the degree of metabolic control.
Precision Telemedicine through Crowdsourced Machine Learning: Testing Variability of Crowd Workers for Video-Based Autism Feature Recognition
Authors: Washington Peter , Leblanc Emilie , Dunlap Kaitlyn , Penev Yordan , Kline Aaron , Paskov Kelley , Sun Min Woo , Chrisman Brianna , Stockham Nathaniel , Varma Maya , Voss Catalin , Haber Nick , Wall Dennis P.
Published: August 2020

Mobilized telemedicine is becoming a key, and even necessary, facet of both precision health and precision medicine. In this study, we evaluate the capability and potential of a crowd of virtual workers—defined as vetted members of popular crowdsourcing platforms—to aid in the task of diagnosing autism. We evaluate workers when crowdsourcing the task of providing categorical ordinal behavioral ratings to unstructured public YouTube videos of children with autism and neurotypical controls. To evaluate emerging patterns that are consistent across independent crowds, we target workers from distinct geographic loci on two crowdsourcing platforms: an international group of workers on Amazon Mechanical Turk (MTurk) (N = 15) and Microworkers from Bangladesh (N = 56), Kenya (N = 23), and the Philippines (N = 25). We feed worker responses as input to a validated diagnostic machine learning classifier trained on clinician-filled electronic health records. We find that regardless of crowd platform or targeted country, workers vary in the average confidence of the correct diagnosis predicted by the classifier. The best worker responses produce a mean probability of the correct class above 80% and over one standard deviation above 50%, accuracy and variability on par with experts according to prior studies. There is a weak correlation between mean time spent on task and mean performance (r = 0.358, p = 0.005). These results demonstrate that while the crowd can produce accurate diagnoses, there are intrinsic differences in crowdworker ability to rate behavioral features. We propose a novel strategy for recruitment of crowdsourced workers to ensure high quality diagnostic evaluations of autism, and potentially many other pediatric behavioral health conditions. Our approach represents a viable step in the direction of crowd-based approaches for more scalable and affordable precision medicine.
Immunotherapy in Corticotroph and Lactotroph Aggressive Tumors and Carcinomas: Two Case Reports and a Review of the Literature
Authors: Duhamel Camille , Ilie Mirela Diana , Salle Henri , Nassouri Adjoa Sika , Gaillard Stephan , Deluche Elise , Assaker Richard , Mortier Laurent , Cortet Christine , Raverot Gérald
Published: August 2020

Once temozolomide has failed, no other treatment is recommended for pituitary carcinomas and aggressive pituitary tumors. Recently, the use of immune checkpoint inhibitors (ICIs) has raised hope, but so far, only one corticotroph carcinoma and one aggressive corticotroph tumor treated with immunotherapies have been reported in the literature. Here, we present two cases, one corticotroph carcinoma and one aggressive prolactinoma (the first one reported in the literature) treated with ipilimumab (1 mg/kg) and nivolumab (3 mg/kg) every three weeks, followed by maintenance treatment with nivolumab (3 mg/kg every 2 weeks) in the case of the corticotroph carcinoma, and we compare them with the two previously reported cases. Patient #1 presented a biochemical partial response (plasma ACTH decreased from 13,813 to 841 pg/mL) and dissociated radiological response to the combined ipilimumab and nivolumab—the pituitary mass decreased from 37 × 32 × 41 to 29 × 23 × 42 mm, and the pre-existing liver metastases decreased in size (the largest one from 45 to 14 mm) or disappeared, while a new 11-mm liver metastasis appeared. The maintenance nivolumab (21 cycles) resulted in a stable disease for the initial liver metastases, and in progressive disease for the newly appeared metastasis (effectively treated with radiofrequency ablation) and the pituitary mass. Patient #2 presented radiological and biochemical progressive disease after two cycles of ICIs—the pituitary mass increased from 38 × 42 × 26 to 53 × 57 × 44 mm, and the prolactin levels increased from 4410 to 9840 ng/mL. In conclusion, ICIs represent a promising therapeutic option for aggressive pituitary tumors and carcinomas. The identification of subgroups of responders will be key.
Protoenzymes: The Case of Hyperbranched Polymer-Scaffolded ZnS Nanocrystals
Authors: Mamajanov Irena , Caudan Melina , Jia Tony Z.
Published: August 2020

Enzymes are biological catalysts that are comprised of small-molecule, metal, or cluster catalysts augmented by biopolymeric scaffolds. It is conceivable that early in chemical evolution, ancestral enzymes opted for simpler, easier to assemble scaffolds. Herein, we describe such possible protoenzymes: hyperbranched polymer-scaffolded metal-sulfide nanocrystals. Hyperbranched polyethyleneimine (HyPEI) and glycerol citrate polymer-supported ZnS nanocrystals (NCs) are formed in a simple process. Transmission electron microscopy (TEM) analyses of HyPEI-supported NCs reveal spherical particles with an average size of 10 nm that undergo only a modest aggregation over a 14-day incubation. The polymer-supported ZnS NCs are shown to possess a high photocatalytic activity in an eosin B photodegradation assay, making them an attractive model for the study of the origin of life under the “Zn world” theory dominated by a photocatalytic proto-metabolic redox reaction network. The catalyst, however, could be easily adapted to apply broadly to different protoenzymatic systems.
Influence of Metallic Deposition on Ceramic Femoral Heads on the Wear Behavior of Artificial Hip Joints: A Simulator Study
Authors: Hembus Jessica , Rößler Lisa , Jackszis Mario , Klinder Annett , Bader Rainer , Zietz Carmen
Published: August 2020

Several retrieval studies have reported on metallic depositions on ceramic femoral heads, but the effect on the wear behavior of artificial hip joints has not been investigated in wear simulator studies. In the present study, retrieved ceramic heads with metallic depositions as third particles were tested against cross-linked ultra-high-molecular-weight polyethylene (UHMWPE) liners in a hip wear simulator. The amount of liner wear and expansion of metallic depositions on the heads were determined before and after wear testing with digital microscopy. The surface roughness of the heads was investigated in areas with and without metallic depositions by laser scanning microscopy. After five million load cycles, a non-significant reduction in the metallic formation on the retrieved heads was found. The metallic areas showed a higher surface roughness compared to unconcerned areas. The liners showed a higher wear rate of 1.57 ± 1.36 mg/million cycles for 28 mm heads and 2.42 ± 0.82 mg/million cycles for 36 mm heads with metallic depositions, in comparison with new ceramic heads with a 28 mm size ((−0.06 ± 0.89) mg/million cycles) and 36 mm size ((2.04 ± 0.46) mg/million cycles). Metallic transfer on ceramic heads can lead to an increased surface roughness and higher wear rates at the UHMWPE liners. Therefore, metallic contact of the ceramic femoral head should be avoided.
Percussion Drilling of Deep Holes Using Picosecond Ultrashort Pulse Laser in Ni-Based Superalloy Coated with Ceramic Thermal Barrier Coatings
Authors: Liu Haodong , Zhao Wanqin , Wang Lingzhi , Shen Xiaowei , Wang Ning , Wang Xu
Published: August 2020

Ni-based superalloy with ceramic thermal barrier coatings (TBCs) is a composite material, which can be used in special environments with high temperature and high pressure such as aeroengine blade. In order to improve the cooling effect of the aeroengine, it is necessary to perform multi-size and large-area holes processing on the surface of blades. As a non-contact processing method with fast processing speed, good processing quality and almost no deformation, laser processing has been one of the important processing methods for film cooling hole processing of aeroengine blades. Percussion drilling is presented using picosecond ultrashort pulse laser in order to explore processing of deep holes in Ni-based superalloy, ceramic TBCs, and ceramic TBCs/substrate multilayer material. The effects of pulses, threshold and wavelength on hole diameter have been discussed, and the experiment on the deep hole ablation with 1064 nm wavelength has been performed. By analyzing the hole size and morphological characteristics of multiple processing parameters, the variation of hole cylindricity is obtained. A high-quality hole, without spatters around the periphery of hole entrance and without recast layer on the side-wall surface, in Ni-based superalloy coated with ceramic TBCs has been drilled. This research has potential applications to blade film cooling holes.
Zr4+-Doped Anatase TiO2 Nanotube Array Electrode for Electrocatalytic Reduction of L-cystine
Authors: Wang Weizhen , Wang Guangxin , Zhao Xuhui , Zhang Xiaofeng , Tang Yuming , Zuo Yu
Published: August 2020

A Zr4+-doped anatase TiO2 nanotube array electrode was prepared using a process that included Ti anodizing, chemical immersion, and heat treatment. The compositions, microstructure, and electrochemical properties of the prepared electrodes were characterized. The results show that Zr4+ was successfully introduced into the TiO2 nanotube array electrodes. Because Zr4+ was doped into the crystal structure of the TiO2and replaced a part of Ti4+ to form more oxygen vacancies and Ti3+, the electrocatalytic activity of the prepared electrodes, for the reduction of L-cystine, was significantly improved.
A Particle-Based Cohesive Crack Model for Brittle Fracture Problems
Authors: Chen Hu , Zhang Y. X. , Zhu Linpei , Xiong Fei , Liu Jing , Gao Wei
Published: August 2020

Numerical simulations of the fracture process are challenging, and the discrete element (DE) method is an effective means to model fracture problems. The DE model comprises the DE connective model and DE contact model, where the former is used for the representation of isotropic solids before cracks initiate, while the latter is employed to represent particulate materials after cracks propagate. In this paper, a DE particle-based cohesive crack model is developed to model the mixed-mode fracture process of brittle materials, aiming to simulate the material transition from a solid phase to a particulate phase. Because of the particle characteristics of the DE connective model, the cohesive crack model is constructed at inter-particle bonds in the connective stage of the model at a microscale. A potential formulation is adopted by the cohesive zone method, and a linear softening relation is employed by the traction–separation law upon fracture initiation. This particle-based cohesive crack model bridges the microscopic gap between the connective model and the contact model and, thus, is suitable to describe the material separation process from solids to particulates. The proposed model is validated by a number of standard fracture tests, and numerical results are found to be in good agreement with the analytical solutions. A notched concrete beam subjected to an impact loading is modeled, and the impact force obtained from the numerical modeling agrees better with the experimental result than that obtained from the finite element method.
Diclofenac Embedded in Silk Fibroin Fibers as a Drug Delivery System
Authors: Opálková Šišková Alena , Kozma Erika , Opálek Andrej , Kroneková Zuzana , Kleinová Angela , Nagy Štefan , Kronek Juraj , Rydz Joanna , Eckstein Andicsová Anita
Published: August 2020

Silk fibroin is a biocompatible, non-toxic, mechanically robust protein, and it is commonly used and studied as a material for biomedical applications. Silk fibroin also gained particular interest as a drug carrier vehicle, and numerous silk formats have been investigated for this purpose. Herein, we have prepared electrospun nanofibers from pure silk fibroin and blended silk fibroin/casein, followed by the incorporation of an anti-inflammatory drug, diclofenac. Casein serves as an excipient in pharmaceutical products and has a positive effect on the gradual release of drugs. The characteristics of the investigated composites were estimated by scanning electron microscope, transmission electron microscope, thermogravimetric analysis, and a lifetime of diclofenac by electron paramagnetic resonance analysis. The cumulative release in vitro of diclofenac sodium salt, together with the antiproliferative effect of diclofenac sodium salt-loaded silk nanofibers against the growth of two cancer cell lines, are presented and discussed.
Thermal and Mechanical Characterization of Banana Fiber Reinforced Composites for Its Application in Injection Molding
Authors: Kusić Dragan , Božič Uroš , Monzón Mario , Paz Rubén , Bordón Pablo
Published: August 2020

Several natural materials and vegetable waste have relevant mechanical properties, mainly in its fiber format. Particularly, banana fiber (BF) provides a close behavior to the widely spread glass fibers, which places it in an advantageous position for use as a reinforcing material in plastic composites. This work characterizes the behavior of acrylonitrile butadiene styrene (ABS), high impact polystyrene (HIPS), and high density polyethylene (HDPE) reinforced with short fibers of bananas from the Canary Islands for its application in molding processes. Several thermal analyses (Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Melt Flow Index (MFI)) and mechanical tests (tensile, flexural, impact, and Dynamic Mechanical Analysis (DMA)) were carried out in composites with different percentages of banana fiber. The thermal results show that the use of banana fiber is viable as a reinforcement in composites for injection molding processes and the mechanical tests indicate an increase in stiffness and an improvement in maximum flexural stress by increasing the fiber content in composites, so the banana fiber turns out to be a natural alternative for the reinforcement of injected plastic components.
Durability and Time-Dependent Properties of Low-Cement Concrete
Authors: Robalo Keila , Soldado Eliana , Costa Hugo , Carvalho Luís , do Carmo Ricardo , Júlio Eduardo
Published: August 2020

The sustainability concerns of concrete construction are focused both on the materials’ eco-efficiency and on the structures’ durability. The present work focuses on the characterization of low cement concrete (LCC), regarding time-dependent and durability properties. LCC studies which explore the influence of the formulation parameters, such as the W/C (water/cement ratio), W/Ceq, (which represents the mass ratio between water and equivalent cement), W/B (water/binder) ratio, and the reference curves, on the aforementioned properties are limited. Thus, several LCC mixtures were formulated considering two dosages of binder powder, 350 and 250 kg/m3, the former with very plastic consistency and the latter with dry consistency, which were combined with a large spectrum of cement replacement rates (up to 70%), through adding fly ash and limestone filler, and with different compactness levels. The main objectives were to study the influence of the formulation parameters on the properties: shrinkage and creep, accelerated carbonation and water absorption, by capillarity, and by immersion. The lifetime of structures produced with the studied LCC was estimated, considering the durability performance, regarding the carbonation effect on the possible corrosion of the steel reinforcement. LCC mixtures with reduced cement dosage and high compactness, despite the high W/C ratios, have low shrinkage and those with higher strength have reduced creep, however depending on W/Ceq ratio. Those mixtures can be formulated and produced presenting good performance regarding carbonation resistance and, consequently, a long lifetime, which is mandatory for a sustainable construction. LCC with 175 kg/m3 of cement dosage is an example with higher lifetime than current concrete with 250 kg/m3 of cement; depending on the XC exposure classes (corrosion induced by carbonation), the amount of cement can be reduced between 37.5% and 42%, since the LCC with 175 kg/m3 of cement allows reducing the concrete cover below the minimum recommended, ensuring simultaneously the required lifetime for current and special structures.
Properties of a Three-Component Mineral Road Binder for Deep-Cold Recycling Technology
Authors: Owsiak Zdzisława , Czapik Przemysław , Zapała-Sławeta Justyna
Published: August 2020

This study examined the physical properties of a three-component mineral binder that is typically used in deep-cold recycling. Test binders were produced using Portland cement, hydrated lime, and cement bypass dust (CBPD) as a byproduct derived from cement production. The suitability of CBPD for use in road binders was assessed. Effects of the three-component binder composition on the setting time, soundness, consistency, and tensile and compressive strengths of the cement pastes and mortars were determined. The pastes and mortars of the same consistency obtained at different w/b ratios were tested. On this basis, the mixture proportions resulting in road binders satisfying the requirements of PN-EN 13282-2:2015 were determined. By mixing cement, lime, and CBPD during the tests, binder classes N1 to N3 were obtained. The replacement of 40% of cement mass with the CBPD high in free lime produced road binders suitable for recycled base layers. The total content of CBPD and hydrated lime in the road binder should not exceed 50% by mass. The potential risk of mortar strength reduction due to KCl recrystallization was discussed.
Decreasing Resistivity of Silicon Carbide Ceramics by Incorporation of Graphene
Authors: Cai Ningning , Guo Daidong , Wu Guoping , Xie Fangmin , Tan Shouhong , Jiang Nan , Li He
Published: August 2020

Silicon carbide (SiC) ceramic is an ideal material for mechanical seal because of its super hardness, high strength, low friction coefficient, good thermal conductivity, and resistance to friction and wear. However, due to relatively high resistivity of SiC ceramic, the triboelectric charge caused by rubbing of mechanical seal end-faces could not be released. It is terrible that the accumulation of triboelectric charge could cause electrochemical corrosion, which would accelerate wear. To decrease the resistivity of SiC ceramic is a desire for improving the performance of mechanical seal. In this research, decreasing resistivity of pressureless sintered SiC ceramic was investigated by conductive pathways through semiconductive grains in a body by incorporation of graphene, which has an extremely low resistivity. With the increasing of graphene from 0 to 2 wt.%, the volume resistivity of SiC ceramics sintered with graphene decreased logarithmically from >106 to around 200 Ω·cm, and the bulk density decreased gradually, from 3.132 to 3.039 g/cm3. In order to meet the requirements of mechanical seal, SiC ceramic sintered with 1 wt.% of graphene, for which the volume resistivity is of 397 Ω·cm, the bulk density is of 3.076 g/cm3, and the flexural strength is of 364 MPa, was optimized when all properties were taken into consideration. It is possible to fabricate low-resistivity SiC ceramic as a useful friction pair material for mechanical seal in a special condition, without excessive loss of their excellent mechanical properties by the introduction of partially connected graphene as conductive pathway into semiconducting ceramic.
Explicit Continuity Conditions for G1 Connection of S-λ Curves and Surfaces
Authors: Hu Gang , Li Huinan , Abbas Muhammad , Miura Kenjiro T. , Wei Guoling
Published: August 2020

The S-λ model is one of the most useful tools for shape designs and geometric representations in computer-aided geometric design (CAGD), which is due to its good geometric properties such as symmetry, shape adjustable property. With the aim to solve the problem that complex S-λ curves and surfaces cannot be constructed by a single curve and surface, the explicit continuity conditions for G1 connection of S-λ curves and surfaces are investigated in this paper. On the basis of linear independence and terminal properties of S-λ basis functions, the conditions of G1 geometric continuity between two adjacent S-λ curves and surfaces are proposed, respectively. Modeling examples imply that the continuity conditions proposed in this paper are easy and effective, which indicate that the S-λ curves and surfaces can be used as a powerful supplement of complex curves and surfaces design in computer aided design/computer aided manufacturing (CAD/CAM) system.
Oxidative Stress and Marine Carotenoids: Application by Using Nanoformulations
Authors: Genç Yasin , Bardakci Hilal , Yücel Çiğdem , Karatoprak Gökçe Şeker , Küpeli Akkol Esra , Hakan Barak Timur , Sobarzo-Sánchez Eduardo
Published: August 2020

Carotenoids are natural fat-soluble pigments synthesized by plants, algae, fungi and microorganisms. They are responsible for the coloration of different photosynthetic organisms. Although they play a role in photosynthesis, they are also present in non-photosynthetic plant tissues, fungi, and bacteria. These metabolites have mainly been used in food, cosmetics, and the pharmaceutical industry. In addition to their utilization as pigmentation, they have significant therapeutically applications, such as improving immune system and preventing neurodegenerative diseases. Primarily, they have attracted attention due to their antioxidant activity. Several statistical investigations indicated an association between the use of carotenoids in diets and a decreased incidence of cancer types, suggesting the antioxidant properties of these compounds as an important factor in the scope of the studies against oxidative stress. Unusual marine environments are associated with a great chemical diversity, resulting in novel bioactive molecules. Thus, marine organisms may represent an important source of novel biologically active substances for the development of therapeutics. Marine carotenoids (astaxanthin, fucoxanthin, β-carotene, lutein but also the rare siphonaxanthin, sioxanthin, and myxol) have recently shown antioxidant properties in reducing oxidative stress markers. Numerous of bioactive compounds such as marine carotenoids have low stability, are poorly absorbed, and own very limited bioavailability. The new technique is nanoencapsulation, which can be used to preserve marine carotenoids and their original properties during processing, storage, improve their physiochemical properties and increase their health-promoting effects. This review aims to describe the role of marine carotenoids, their potential applications and different types of advanced nanoformulations preventing and treating oxidative stress related disorders.
Integrated Membrane–Electrocoagulation System for Removal of Celestine Blue Dyes in Wastewater
Authors: Saad Muhammad Syaamil , Balasubramaniam Lila , Wirzal Mohd Dzul Hakim , Abd Halim Nur Syakinah , Bilad Muhammad Roil , Md Nordin Nik Abdul Hadi , Adi Putra Zulfan , Ramli Fuad Nabil
Published: August 2020

The textile industry provides for the needs of people especially in apparel and household items. The industry also discharges dye-containing wastewater that is typically challenging to treat. Despite the application of the biological and chemical treatments for the treatment of textile wastewater, these methods have their own drawbacks such as non-environment friendly, high cost and energy intensive. This research investigates the efficiency of the celestine blue dye removal from simulated textile wastewater by electrocoagulation (EC) method using iron (Fe) electrodes through an electrolytic cell, integrated with nylon 6,6 nanofiber (NF) membrane filtration for the separation of the flocculants from aqueous water. Based on the results, the integrated system achieves a high dye removal efficiency of 79.4%, by using 1000 ppm of sodium chloride as the electrolyte and 2 V of voltage at a constant pH of 7 and 10 ppm celestine blue dye solution, compared to the standalone EC method in which only 43.2% removal was achieved. Atomic absorption spectroscopy analysis was used to identify the traces of iron in the residual EC solution confirming the absence of iron. The EC-integrated membrane system thus shows superior performance compared to the conventional method whereby an additional 10–30% of dye was removed at 1 V and 2 V using similar energy consumptions.
Application of Vacuum Techniques in Shell Moulds Produced by Additive Manufacturing
Authors: Rodríguez-González P. , Robles Valero P. E. , Fernández-Abia A. I. , Castro-Sastre M. A. , Barreiro García J.
Published: August 2020

This research shows the feasibility of the additive manufacturing technique (AM), Binder Jetting (BJ), for the production of shell moulds, which are filled by vacuum suction in the field of aluminium parts production. In addition, this study compares the gravity pouring technique and highlights the advantages of using vacuum techniques in AM moulds. A numerical simulation was carried out to study the behaviour of the liquid metal inside the moulds and the cooling rate of parts was analysed. The results show that in the gravity-pouring mould, the velocity in the gate causes moderate turbulence with small waves. However, vacuum suction keeps the velocity constant by eliminating waves and the filling process is homogeneous. Regarding dimensional accuracy, the staircase effect on the surface of the 3D moulds was the most critical aspect. The vacuum provides very homogeneous values of roughness across the entire surface of the part. Similarly, 3D scanning of castings revealed more accurate dimensions thanks to the help of vacuum forces. Finally, the microstructure of the cross section of the moulded parts shows that the porosity decreases with the vacuum filled. In both cases, the origin of the pores corresponds to gas entrapment and shrinkage during the filling process, the binder vaporization and nucleation points creation, leading to pores by shrinkage, gas entrapment or a mixture of both. This is the first study that uses vacuum filling techniques in moulds created by BJ, demonstrating the feasibility and advantages of AM using vacuum techniques, as an alternative to traditional casting.
Fatigue Life Assessment of Revised Cope-Hole Details in Steel Truss Bridges
Authors: Liao Ping , Qu Bing , Huang Yaolong , Jia Yi , Wang Yongbao , Zhu Haifeng
Published: August 2020

In recent years, various welded details with complex local structure, ambiguous fatigue performance have appeared in fully welded steel truss bridges, however, they are not covered in the current design specifications. In order to study the fatigue performance of revised cope-hole details, fatigue performance experiments were designed and carried out on three specimens of revised detail with the same dimensions but subjected to different stress amplitude. Local finite element model of the revised cope-hole detail was established for further stress analysis. The results of finite element analysis were basically consistent with the static test results at majority of measurement points. Based on the existing fatigue test data and fatigue strength of cope-hole details defined in Eurocode and JSSC design code, the fatigue performance of revised cope-hole details was evaluated. The S-N fitting curve with the failure probability of 2.3% was obtained from the fatigue experiment results. The fatigue stress amplitude was 59.5 MPa when fatigue loading cycle was 2 × 106. It can be concluded that the fatigue performance of revised cope-hole detail was better than that of previous welded detail, which indicated that the revised detail had a significant improvement.
Recent Advances in EBSD Characterization of Metals
Authors: Carneiro Íris , Simões Sónia
Published: August 2020

Electron backscatter diffraction (EBSD) has been attracting enormous interest in the microstructural characterization of metals in recent years. This characterization technique has several advantages over conventional ones, since it allows obtaining a wide range of characterization possibilities in a single method, which is not possible in others. The grain size, crystallographic orientation, texture, and grain boundary character distribution can be obtained by EBSD analysis. Despite the limited resolution of this technique (20–50 nm), EBSD is powerful, even for nanostructured materials. Through this technique, the microstructure can be characterized at different scales and levels with a high number of microstructural characteristics. It is known that the mechanical properties are strongly related to several microstructural aspects such as the size, shape, and distribution of grains, the presence of texture, grain boundaries character, and also the grain boundary plane distribution. In this context, this work aims to describe and discuss the possibilities of microstructural characterization, recent advances, the challenges in sample preparation, and the application of the EBSD in the characterization of metals.
Associations of BMI and Body Fat with Urine Metabolome in Adolescents Are Sex-Specific: A Cross-Sectional Study
Authors: Brachem Christian , Langenau Julia , Weinhold Leonie , Schmid Matthias , Nöthlings Ute , Oluwagbemigun Kolade
Published: August 2020

Epidemiologic studies examining the relationship between body composition and the urine metabolome may improve our understanding of the role of metabolic dysregulation in body composition-related health conditions. Previous studies, mostly in adult populations, have focused on a single measure of body composition, body mass index (BMI), and sex-specific associations are rarely explored. We investigate sex-specific associations of two measures of body composition—BMI and body fat (BF)—with the urine metabolome in adolescents. In 369 participants (age 16–18, 49% female) of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study, we examined sex-specific associations of these two measures of body composition, BMI and BF, and 1407 (467 unknown) 24 h urine metabolites analyzed by untargeted metabolomics cross-sectionally. Missing metabolites were imputed. We related metabolites (dependent variable) to BMI and BF (independent variable) separately using linear regression. The models were additionally adjusted for covariates. We found 10 metabolites associated with both BMI and BF. We additionally found 11 metabolites associated with only BF, and nine with only BMI. None of these associations was in females. We observed a strong sexual dimorphism in the relationship between body composition and the urine metabolome.