bluuebunny/crossref_metadata_2025 huggingface dataset:
The Major Factors Causing the Microspore Abortion of Genic Male Sterile Mutant NWMS1 in Wheat (Triticum aestivum L.)
Authors: Li Junchang , Zhang Jing , Li Huijuan , Niu Hao , Xu Qiaoqiao , Jiao Zhixin , An Junhang , Jiang Yumei , Li Qiaoyun , Niu Jishan
Published: December 2019

Male sterility is a valuable trait for genetic research and production application of wheat (Triticum aestivum L.). NWMS1, a novel typical genic male sterility mutant, was obtained from Shengnong 1, mutagenized with ethyl methane sulfonate (EMS). Microstructure and ultrastructure observations of the anthers and microspores indicated that the pollen abortion of NWMS1 started at the early uninucleate microspore stage. Pollen grain collapse, plasmolysis, and absent starch grains were the three typical characteristics of the abnormal microspores. The anther transcriptomes of NWMS1 and its wild type Shengnong 1 were compared at the early anther development stage, pollen mother cell meiotic stage, and binucleate microspore stage. Several biological pathways clearly involved in abnormal anther development were identified, including protein processing in endoplasmic reticulum, starch and sucrose metabolism, lipid metabolism, and plant hormone signal transduction. There were 20 key genes involved in the abnormal anther development, screened out by weighted gene co-expression network analysis (WGCNA), including SKP1B, BIP5, KCS11, ADH3, BGLU6, and TIFY10B. The results indicated that the defect in starch and sucrose metabolism was the most important factor causing male sterility in NWMS1. Based on the experimental data, a primary molecular regulation model of abnormal anther and pollen developments in mutant NWMS1 was established. These results laid a solid foundation for further research on the molecular mechanism of wheat male sterility.
High Mobility Group Box-1 and Diabetes Mellitus Complications: State of the Art and Future Perspectives
Authors: Biscetti Federico , Rando Maria Margherita , Nardella Elisabetta , Cecchini Andrea Leonardo , Pecorini Giovanni , Landolfi Raffaele , Flex Andrea
Published: December 2019

Diabetes mellitus (DM) is an endemic disease, with growing health and social costs. The complications of diabetes can affect potentially all parts of the human body, from the heart to the kidneys, peripheral and central nervous system, and the vascular bed. Although many mechanisms have been studied, not all players responsible for these complications have been defined yet. High Mobility Group Box-1 (HMGB1) is a non-histone nuclear protein that has been implicated in many pathological processes, from sepsis to ischemia. The purpose of this review is to take stock of all the most recent data available on the role of HMGB1 in the complications of DM.
Rheology of Dispersions of High-Aspect-Ratio Nanofibers Assembled from Elastin-Like Double-Hydrophobic Polypeptides
Authors: Sugawara-Narutaki Ayae , Yasunaga Sawako , Sugioka Yusuke , Le Duc H. T. , Kitamura Issei , Nakamura Jin , Ohtsuki Chikara
Published: December 2019

Elastin-like polypeptides (ELPs) are promising candidates for fabricating tissue-engineering scaffolds that mimic the extracellular environment of elastic tissues. We have developed a “double-hydrophobic” block ELP, GPG, inspired by non-uniform distribution of two different hydrophobic domains in natural elastin. GPG has a block sequence of (VGGVG)5-(VPGXG)25-(VGGVG)5 that self-assembles to form nanofibers in water. Functional derivatives of GPG with appended amino acid motifs can also form nanofibers, a display of the block sequence’s robust self-assembling properties. However, how the block length affects fiber formation has never been clarified. This study focuses on the synthesis and characterization of a novel ELP, GPPG, in which the central sequence (VPGVG)25 is repeated twice by a short linker sequence. The self-assembly behavior and the resultant nanostructures of GPG and GPPG were when compared through circular dichroism spectroscopy, atomic force microscopy, and transmission electron microscopy. Dynamic rheology measurements revealed that the nanofiber dispersions of both GPG and GPPG at an extremely low concentration (0.034 wt%) exhibited solid-like behavior with storage modulus G′ > loss modulus G” over wide range of angular frequencies, which was most probably due to the high aspect ratio of the nanofibers that leads to the flocculation of nanofibers in the dispersion.
SLC38A10 (SNAT10) is Located in ER and Golgi Compartments and Has a Role in Regulating Nascent Protein Synthesis
Authors: Tripathi Rekha , Hosseini Kimia , Arapi Vasiliki , Fredriksson Robert , Bagchi Sonchita
Published: December 2019

The solute carrier (SLC) family-38 of transporters has eleven members known to transport amino acids, with glutamine being a common substrate for ten of them, with SLC38A9 being the exception. In this study, we examine the subcellular localization of SNAT10 in several independent immortalized cell lines and stem cell-derived neurons. Co-localization studies confirmed the SNAT10 was specifically localized to secretory organelles. SNAT10 is expressed in both excitatory and inhibitory neurons in the mouse brain, predominantly in the endoplasmic reticulum, and in the Golgi apparatus. Knock-down experiments of SNAT10, using Slc38a10-specific siRNA in PC12 cells reduced nascent protein synthesis by more than 40%, suggesting that SNAT10 might play a role in signaling pathways that regulate protein synthesis, and may act as a transceptor in a similar fashion to what has been shown previously for SLC38A2 (SNAT2) and SNAT9(SLC38A9).
The Microbiota and Cancer Cachexia
Authors: Herremans Kelly M. , Riner Andrea N. , Cameron Miles E. , Trevino Jose G.
Published: December 2019

Cancer cachexia is a multifactorial syndrome defined by weight loss, muscle wasting, and systemic inflammation. It affects the majority of patients with advanced cancer and is associated with poor treatment response, early mortality and decreased quality of life. The microbiota has been implicated in cancer cachexia through pathways of systemic inflammation, gut barrier dysfunction and muscle wasting. The imbalance of the microbiota, known as dysbiosis, has been shown to influence cancer cachexia. Bacteria that play beneficial and detrimental roles in the disease pathogenesis have been identified. The phenotype of cancer cachexia is associated with decreased levels of Lactobacillales and increased levels of Enterobacteriaceae and Parabacteroides. Currently, there are no treatment options that demonstrate increased survival or the quality of life in patients suffering from cancer cachexia. Through the manipulation of beneficial bacteria in the gut microbiota, different treatment options have been explored. Prebiotics and probiotics have been shown to improve outcomes in animal models of cachexia. Expounding on this mechanism, fecal microbiota transplant (FMT) holds promise for a future treatment of cancer cachexia. Further research is necessary to address this detrimental disease process and improve the lives of patients suffering from cancer cachexia.
Effects of Farnesiferol B on Ischemia-Reperfusion-Induced Renal Damage, Inflammation, and NF-κB Signaling
Authors: Zhang Lu , Fu Xianjun , Gui Ting , Wang Tianqi , Wang Zhenguo , Kullak-Ublick Gerd A. , Gai Zhibo
Published: December 2019

Background: G-protein-coupled bile acid receptor (TGR5), a membrane bile acid receptor, regulates macrophage reactivity, and attenuates inflammation in different disease models. However, the regulatory effects of TGR5 in ischemia/reperfusion (I/R)-induced kidney injury and inflammation have not yet been extensively studied. Therefore, we hypothesize that Farnesiferol B, a natural TGR5 agonist, could alleviate renal I/R injury by reducing inflammation and macrophage migration through activating TGR5. Methods: Mice were treated with Farnesiferol B before I/R or sham procedures. Renal function, pathological analysis, and inflammatory mediators were examined. In vitro, the regulatory effects of Farnesiferol B on the Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway in macrophages were investigated. Results: After I/R, Farnesiferol B-treated mice displayed better renal function and less tubular damage. Farnesiferol B reduced renal oxidative stress and inflammation significantly. In vitro, Farnesiferol B treatment alleviated lipopolysaccharide (LPS)-induced macrophage migration and activation, as well as LPS-induced NF-κB activation through TGR5. Conclusions: Farnesiferol B could protect kidney function from I/R-induced damage by attenuating inflammation though activating TGR5 in macrophages. Farnesiferol B might be a potent TGR5 ligand for the treatment of I/R-induced renal inflammation.
Resveratrol Treatment Enhances the Cellular Response to Leptin by Increasing OBRb Content in Palmitate-Induced Steatotic HepG2 Cells
Authors: Ardid-Ruiz Andrea , Ibars Maria , Mena Pedro , Del Rio Daniele , Muguerza Begoña , Arola Lluís , Aragonès Gerard , Suárez Manuel
Published: December 2019

The interaction of leptin with its hepatic longest receptor (OBRb) promotes the phosphorylation of signal transducer and activator of transcription-3 (STAT3), protecting the liver from lipid accumulation. However, leptin signalling is disrupted in hepatic steatosis, causing leptin resistance. One promising strategy to combat this problem is the use of bioactive compounds such as polyphenols. Since resveratrol (RSV) is a modulator of lipid homeostasis in the liver, we investigated whether treatment with different doses of RSV restores appropriate leptin action and fat accumulation in palmitate-induced steatotic human hepatoma (HepG2) cells. Both RSV metabolism and the expression of molecules implicated in leptin signalling were analysed. RSV at a 10 μM concentration was entirely metabolized to resveratrol-3-sulfate after 24 and counteracted leptin resistance by increasing the protein levels of OBRb. In addition, RSV downregulated the expression of lipogenic genes including fatty acid synthase (Fas) and stearoyl-CoA desaturase-1 (Scd1) without any significant change in Sirtuin-1 (SIRT1) enzymatic activity. These results demonstrate that RSV restored leptin sensitivity in a cellular model of hepatic steatosis in a SIRT1-independent manner.
New Species-Specific Primers for Molecular Diagnosis of Bactrocera minax and Bactrocera tsuneonis (Diptera: Tephritidae) in China Based on DNA Barcodes
Authors: Zheng Linyu , Zhang Yue , Yang Wenzhao , Zeng Yiying , Jiang Fan , Qin Yujia , Zhang Jiafeng , Jiang Zhaochun , Hu Wenzhao , Guo Dijin , Wan Jia , Zhao Zihua , Liu Lijun , Li Zhihong
Published: December 2019

Tephritidae fruit flies (Diptera: Tephritidae) are regarded as important damage-causing species due to their ability to cause great economic losses in fruit and vegetable crops. Bactrocera minax and Bactrocera tsuneonis are two sibling species of the subgenus Tetradacus of Bactrocera that are distributed across a limited area of China, but have caused serious impacts. They share similar morphological characteristics. These characteristics can only be observed in the female adult individuals. The differences between them cannot be observed in preimaginal stages. Thus, it is difficult to distinguish them in preimaginal stages morphologically. In this study, we used molecular diagnostic methods based on cytochrome c oxidase subunit I and species-specific markers to identify these two species and improve upon the false-positive results of previous species-detection primers. DNA barcode sequences were obtained from 900 individuals of B. minax and 63 individuals of B. tsuneonis. Based on these 658 bp DNA barcode sequences of the cytochrome c oxidase subunit I gene, we successfully designed the species-specific primers for B. minax and B. tsuneonis. The size of the B. minax specific fragment was 422 bp and the size of the B. tsuneonis specific fragment was 456 bp. A series of PCR trials ensured the specificity of these two pairs of primers. Sensitivity assay results demonstrated that the detection limit for the DNA template concentration was 0.1~1 ng/μL for these two species. In this study, we established a more reliable, rapid, and low-cost molecular identification method for all life stages of B. minax and B. tsuneonis. Species-specific PCR can be applied in plant quarantine, monitoring and control of B. minax and B. tsuneonis.
Mass-Rearing of Drosophila suzukii for Sterile Insect Technique Application: Evaluation of Two Oviposition Systems
Authors: Sassù Fabiana , Nikolouli Katerina , Caravantes Silvana , Taret Gustavo , Pereira Rui , Vreysen Marc J. B. , Stauffer Christian , Cáceres Carlos
Published: December 2019

Drosophila suzukii (Diptera: Drosophilidae) is an invasive pest of a wide range of commercial soft-skinned fruits. To date, most management tactics are based on spraying of conventional and/or organic insecticides, baited traps, and netting exclusion. Interest has been expressed in using the sterile insect technique (SIT) as part of area-wide integrated pest management (AW-IPM) programs to control D. suzukii infestations. Mass-rearing protocols are one of the prerequisites for successful implementation of the SIT. To establish mass-rearing methods for this species, two different egg-collection systems were developed and compared with respect to the number of eggs produced, egg viability, pupa and adult recovery, adult emergence rate, and flight ability. Female flies kept in cages equipped with a wax panel produced significantly more eggs with higher viability and adult emergence rate, as compared to the netted oviposition system. The wax panel system was also more practical and less laborious regarding the collection of eggs. Furthermore, the wax panel oviposition system can be adapted to any size or design of an adult cage. In conclusion, this system bears great promise as an effective system for the mass production of D. suzukii for SIT.
Efficacy Study of Anti-Endomysium Antibodies for Celiac Disease Diagnosis: A Retrospective Study in a Spanish Pediatric Population
Authors: Roca María , Donat Ester , Marco-Maestud Natalia , Masip Etna , Hervás-Marín David , Ramos David , Polo Begoña , Ribes-Koninckx Carmen
Published: December 2019

The aim of this study was to assess the efficacy of anti-endomysium antibodies (EMA) as a serological marker for celiac disease (CD) diagnosis in a pediatric population. A retrospective study of pediatric patients who underwent a CD serological markers study: EMA and anti-tissue transglutaminase antibodies (anti-TG2). Clinical symptomatology, degree of histological lesion, human leukocyte antigen (HLA) haplotype compatible with CD (HLA DQ2 and/or DQ8), and final diagnosis were taken into account. We included 445 patients who were classified in two groups according to the final diagnosis. Group 1: 232 children with CD, 91.4% of whom exhibited small intestinal villous atrophy, 228 being EMA-positive and four EMA-negative. Group 2: 213 children with a non-CD diagnosis, 212 EMA negative and one EMA positive. Both antibodies, EMA and anti-TG2, reached similar sensitivities, 98% and 99% respectively, while EMA had a higher specificity (99%) than anti-TG2 (93%). By using both markers combined, compared to using anti-TG2 alone, 5.7% of patients are better diagnosed. However, when we compare the efficacy of EMA and anti-TG2 in asymptomatic and symptomatic patients, the sensitivity of EMA is 98% irrespective of symptoms, thus higher than for anti-TG2 ≥10 × upper limit of normal (ULN) (respectively 77% and 84%). Our results support the use of EMA to increase CD diagnostic accuracy in a non-biopsy approach, especially in asymptomatic children.
Dose-Ranging Study of Ramosetron for the Prevention of Nausea and Vomiting after Laparoscopic Gynecological Surgery: A Prospective Randomized Study
Authors: Cho Jin Sun , Kim Sang Wun , Lee Sugeun , Yoo Young Chul
Published: December 2019

Patients undergoing laparoscopic gynecologic surgery and receiving postoperative analgesia with opioids have a high risk of postoperative nausea and vomiting (PONV). We compared the antiemetic efficacy of three doses of ramosetron in this high-risk population. In this prospective, double-blind trial, 174 patients randomly received ramosetron 0.3 mg (R0.3 group; n = 58), 0.45 mg (R0.45 group; n = 58), or 0.6 mg (R0.6 group; n = 58) at the end of surgery. The primary outcome was the incidence of PONV during the first postoperative 48 h. Nausea severity, pain scores, adverse events, and patient satisfaction (1–4; 4, excellent) were assessed. The incidence of PONV was not different between groups (35%, 38%, and 35% in R0.3, R0.45, and R0.6 groups; p = 0.905). Nausea severity, pain scores, and incidence of adverse events (dizziness, headache, or sedation) were similar between groups. Compared to the R0.3 group, the R0.45 and R0.6 groups had lower incidence of premature discontinuation of fentanyl-based patient-controlled analgesia primarily because of intractable PONV (9% and 5% vs. 24%; p = 0.038), and higher satisfaction scores (3.4 ± 0.8 and 3.3 ± 0.7 vs. 2.4 ± 0.9; p = 0.005). Compared to ramosetron 0.3 mg, ramosetron 0.45 and 0.6 mg did not reduce PONV, but reduced premature discontinuation of patient-controlled analgesia and increased patient satisfaction, without increasing adverse events.
Toward Engineering the Mannose 6-Phosphate Elaboration Pathway in Plants for Enzyme Replacement Therapy of Lysosomal Storage Disorders
Authors: Zeng Ying , He Xu , Danyukova Tatyana , Pohl Sandra , Kermode Allison R.
Published: December 2019

Mucopolysaccharidosis (MPS) I is a severe lysosomal storage disease caused by α-L-iduronidase (IDUA) deficiency, which results in accumulation of non-degraded glycosaminoglycans in lysosomes. Costly enzyme replacement therapy (ERT) is the conventional treatment for MPS I. Toward producing a more cost-effective and safe alternative to the commercial mammalian cell-based production systems, we have produced recombinant human IDUA in seeds of an Arabidopsis mutant to generate the enzyme in a biologically active and non-immunogenic form containing predominantly high mannose N-linked glycans. Recombinant enzyme in ERT is generally thought to require a mannose 6-phosphate (M6P) targeting signal for endocytosis into patient cells and for intracellular delivery to the lysosome. Toward effecting in planta phosphorylation, the human M6P elaboration machinery was successfully co-expressed along with the recombinant human IDUA using a single multi-gene construct. Uptake studies using purified putative M6P-IDUA generated in planta on cultured MPS I primary fibroblasts indicated that the endocytosed recombinant lysosomal enzyme led to substantial reduction of glycosaminoglycans. However, the efficiency of the putative M6P-IDUA in reducing glycosaminoglycan storage was comparable with the efficiency of the purified plant mannose-terminated IDUA, suggesting a poor in planta M6P-elaboration by the expressed machinery. Although the in planta M6P-tagging process efficiency would need to be improved, an exciting outcome of our work was that the plant-derived mannose-terminated IDUA yielded results comparable to those obtained with the commercial IDUA (Aldurazyme® (Sanofi, Paris, France)), and a significant amount of the plant-IDUA is trafficked by a M6P receptor-independent pathway. Thus, a plant-based platform for generating lysosomal hydrolases may represent an alternative and cost-effective strategy to the conventional ERT, without the requirement for additional processing to create the M6P motif.
Ceramide Content in Liver Increases Along with Insulin Resistance in Obese Patients
Authors: Razak Hady Hady , Błachnio-Zabielska Agnieszka U. , Szczerbiński Łukasz , Zabielski Piotr , Imierska Monika , Dadan Jacek , Krętowski Adam J.
Published: December 2019

The liver plays a central role in the glucose and lipid metabolism. Studies performed on animal models have shown an important role of lipid accumulation in the induction of insulin resistance. We sought to explain whether in obese humans, the insulin resistance is associated with hepatic ceramide accumulation. The experiments were conducted on obese men and women. Each gender was divided into three groups: Normal glucose tolerance group (NGT), Impaired glucose tolerance group (IGT), and Type 2 diabetic subjects (T2D). Ceramide (Cer) content was analyzed with the use of LC/MS/MS. An oral glucose tolerance test (OGTT), glycosylated hemoglobin (HbA1c), percentage body fat (FAT%), and body mass index (BMI) was also measured. Total hepatic ceramide was significantly higher in T2D females as compared to NGT females (p < 0.05), whereas in males, total ceramide was significantly higher in IGT and T2D as compared to NGT (p < 0.05). In both, men and women, the highest increase in T2D subjects, was observed in C16:0-Cer, C18:0:-Cer, C22:0-Cer, and C24:0-Cer (p < 0.05) as compared to NGT group. Interestingly, glucose (at 0′ and at 120′ in OGTT) and HbA1c positively correlated with the ceramide species that most increased in T2D patients (C16:0-Cer, C18:0-Cer, C22:0-Cer, and C24:0-Cer). In men glucose and HbA1c significantly correlated with only C22:0-Cer. This is one of the few studies comparing hepatic ceramide content in severely obese patients. We found that, ceramide content increased in diabetic patients, both in men and women, and the content of ceramide correlated with glycemic parameters. These data indicate ceramide contribution to the induction of hepatic insulin resistance.
Tax Arrears Versus Financial Ratios in Bankruptcy Prediction
Authors: Lukason Oliver , Andresson Art
Published: December 2019

This paper aims to compare the usefulness of tax arrears and financial ratios in bankruptcy prediction. The analysis is based on the whole population of Estonian bankrupted and survived SMEs from 2013 to 2017. Logistic regression and multilayer perceptron are used as the prediction methods. The results indicate that closer to bankruptcy, tax arrears’ information yields a higher prediction accuracy than financial ratios. A combined model of tax arrears and financial ratios is more useful than the individual models. The results enable us to outline several theoretical and practical implications.
Investigation of Electrically-Assisted Rolling Process of Corrugated Surface Microstructure with T2 Copper Foil
Authors: Xue Shaoxi , Wang Chunju , Chen Pengyu , Xu Zhenhai , Cheng Lidong , Guo Bin , Shan Debin
Published: December 2019

Electrically-assisted (EA) forming is a low-cost and high-efficiency method to enhance the formability of materials. In the study, EAF tensile tests are carried out to study the properties of T2 copper foil in an annealed state, and the effect of the electric current on the forming quality of corrugated foils is further studied in the EA rolling forming process. The result shows that the current reduces the flow stress and the fracture strain, which is different from the result of rolled samples. The joule heating effect on mechanical properties is significant in EA tension, and the softening effect of the surface layer can be observed at tensile strength, due to the grain size effect. Moreover, the current can weaken the grain size effect. In the rolling forming process, the influence of different electrical parameters on the forming height is remarkable, especially for the rolled T2 copper. The appropriate electrical parameters can improve the forming height, while keeping a small thickness thinning. Nevertheless, the high current density will lead to local rupture. This study proves that the current can improve the forming quality of the corrugated foils and is a promising surface texture forming process.
Ultrasound-Assisted Preparation, Characterization, and Antibacterial Activity of Montmorillonite Modified by ε-Polylysine Hydrochloride
Authors: Yuan Xinfu , Zhang Jinli , Zhang Rui , Liu Jingyuan , Wang Wentao , Hou Hanxue
Published: December 2019

In this study, two types of antibacterial montmorillonites (Mt) were prepared using a facile method. The Mt modified with ε-polylysine hydrochloride (ε-PL) was named PL-Mt, while the Mt dually modified with dioctadecyl dimethylammonium chloride (D1821) and ε-PL was named PL-OMt. The results of the X-ray diffraction, Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) of the PL-Mt indicated that 30% ε-PL was the most suitable amount for intercalating the Mt. The particle size and distribution of the ε-PL in the solution demonstrated that the Mt d-value could not be further increased owing to the increasing ε-PL diameter. The result of the X-ray diffraction of PL-OMt displayed that ultrasonic treatment at 600 W facilitated ε-PL to intercalate into the OMt interlayer space. The PL-OMt prepared with ultrasonic treatment at 600 W exhibited antibacterial activity against Escherichia coli and Bacillus subtilis superior to that of the PL-OMt prepared with higher-power ultrasonic treatment. Thus, the addition of 30% ε-PL based on the dry Mt mass is the most suitable ratio for preparing PL-Mt, while ultrasonic treatment at 600 W is the most suitable for preparing PL-OMt. These findings may expand the application fields of ε-PL.
Experimental Investigation and Optimal Prediction of Maximum Forming Angle and Surface Roughness of an Al/SUS Bimetal Sheet in an Incremental Forming Process Using Machine Learning
Authors: Abd Ali Raneen , Chen Wenliang , Al-Furjan M.S.H. , Jin Xia , Wang Ziyu
Published: December 2019

Bimetal sheets have superior properties as they combine different materials with different characteristics. Producing bimetal parts using a single-point incremental forming process (SPIF) has increased recently with the development of industrial requirements. Such types of sheets have multiple functions that are not applicable in the case of monolithic sheets. In this study, the correlation between the operating variables, the maximum forming angle, and the surface roughness is established based on the ensemble learning using gradient boosting regression tree (GBRT). In order to obtain the dataset for the machine learning, a series of experiments with continuous variable angle pyramid shape were carried out based on D-Optimal design. This design is created based on numerical variables (i.e., tool diameter, step size, and feed rate) and categorical variable (i.e., layer arrangement). The grid search cross-validation (CV) method was used to determine the optimum GBRT parameters prior to model training. After the parameter tuning and model selection, the model with a better generalization performance is obtained. The reliability of the predictive models is confirmed by the testing samples. Furthermore, the microstructure of the aluminum/stainless steel (Al/SUS) bimetal sheet is analyzed under different levels of operating parameters and layer arrangements. The microstructure results reveal that severe cracks are attained in the case of a small tool diameter while a clear refinement is observed when a high tool diameter value with small step down is used for both Al and SUS layers.
Frost Resistance Number to Assess Freeze and Thaw Resistance of Non-Autoclaved Aerated Concretes Containing Ground Granulated Blast-Furnace Slag and Micro-Silica
Authors: Sharafutdinov Eldar , Shon Chang-Seon , Zhang Dichuan , Chung Chul-Woo , Kim Jong , Bagitova Saltanat
Published: December 2019

Aerated concrete (AC), such as cellular concrete, autoclaved aerated concrete (AAC), and non-autoclaved aerated concrete (NAAC), having excellent insulation properties, is commonly used in buildings located in cold regions, such as Nur-Sultan in Kazakhstan, the second coldest capital city in the world, because it can contribute to a large energy saving. However, when the AC is directly exposed to the repeated freeze and thaw (F-T) cycles, its F-T resistance can be critical because of lower density and scaling resistance of the AC. Moreover, the evaluation of the F-T resistance of the AC based on the durability factor (DF) calculated by using the relative dynamic modulus of elasticity may overestimate the frost resistance of the AC due to the millions of evenly distributed air voids in spite of its weak scaling resistance. In the present study, the F-T resistance of NAAC mixtures with various binary or ternary combinations of ground granulated blast-furnace slag (GGBFS) and micro-silica was assessed mainly using the ASTM C 1262/C1262M-16 Standard Test Method for Evaluating the Freeze-Thaw Durability of Dry-Cast Segmental Retaining Wall Units and Related Concrete Units. Critical parameters to affect the F-T resistance performance of the NAAC mixture such as compressive strength, density, water absorption, air–void ratio (VR), moisture uptake, durability factor (DF), weight loss (Wloss), the degree of saturation (Sd), and residual strength (Sres) were determined. Based on the determined parameter values, frost resistance number (FRN) has been developed to evaluate the F-T resistance of the NAAC mixture. Test results showed that all NAAC mixtures had good F-T resistance when they were evaluated with DF. Binary NAAC mixtures generally showed higher Sd and Wloss and lower DF and Sres than those of ternary NAAC mixtures. It was determined that the Sd was a key factor for the F-T resistance of NAAC mixtures. Finally, the developed FRN could be an appropriate tool to evaluate the F-T resistance of the NAAC mixture.
Scanning Magnetic Microscope Using a Gradiometric Configuration for Characterization of Rock Samples
Authors: Araujo Jefferson F. D. F. , Reis Andre L. A. , Correa Angela A. P. , Yokoyama Elder , Oliveira Vanderlei C. , Mendoza Leonardo A. F. , Pacheco Marcos A. C. , Luz-Lima Cleanio , Santos Amanda F. , Osorio G. Fredy G. , Brito Giancarlo E. , Araujo Wagner W. R. , Tahir  , Bruno Antonio C. , Del Rosso Tommaso
Published: December 2019

Scanning magnetic microscopy is a tool that has been used to map magnetic fields with good spatial resolution and field sensitivity. This technology has great advantages over other instruments; for example, its operation does not require cryogenic technology, which reduces its operational cost and complexity. Here, we presented a spatial domain technique based on an equivalent layer approach for processing the data set produced by magnetic microscopy. This approach estimated a magnetic moment distribution over a fictitious layer composed by a set of dipoles located below the observation plane. For this purpose, we formulated a linear inverse problem for calculating the magnetic vector and its amplitude. Vector field maps are valuable tools for the magnetic interpretation of samples with a high spatial variability of magnetization. These maps could provide comprehensive information regarding the spatial distribution of magnetic carriers. In addition, this approach might be useful for characterizing isolated areas over samples or investigating the spatial magnetization distribution of bulk samples at the micro and millimeter scales. This technique could be useful for many applications that require samples that need to be mapped without a magnetic field at room temperature, including rock magnetism.
Linear Tuning of Phase-Matching Temperature in LiNbO3:Zr Crystals by MgO Co-Doping
Authors: Kong Tengfei , Liu Hongde , Xue Liyun , Wang Weiwei , Saeed Shahzad , Zheng Dahuai , Liu Shiguo , Chen Shaolin , Zhang Ling , Kong Yongfa , Xu Jingjun
Published: December 2019

We grew a series of co-doped LiNbO3 crystals with fixed 1.5 mol % ZrO2 and various MgO concentrations (1.0, 3.0, 4.0, 6.0 mol %), and investigated their optical properties and defect structures. By 3.0 mol % MgO co-doping, the optical damage resistance at 532 nm reached 6.5 × 106 W/cm2, while the phase-matching temperature for doubling 1064 nm was only 29.3 °C—close to room temperature—which was conducive to realizing the 90° phase matching at room temperature by slightly modulating the incident angle of the fundamental beam. Notably, we found that the phase-matching temperature increased linearly with the increase of MgO doping, and this linear dependence helped us to grow the high-quality crystal for room temperature 90° phase matching. Moreover, the defect analysis indicated that the linear tuning of phase-matching temperature might be attributed to Mg Li + + Zr Nb − neutral pairs in crystals.
Influence of Secondary Reinforcement on Behaviour of Corbels with Various Types of High-Performance Fiber-Reinforced Cementitious Composites
Authors: Md Zin Nasuha , Al-Fakih Amin , Nikbakht Ehsan , Teo Wee , Anwar Gad Mahmoud
Published: December 2019

An experimental study is conducted to determine the influence of secondary reinforcement on the behaviour of corbels fabricated with three different types of high-performance fiber-reinforced cementitious composites, including engineered cementitious concrete (ECC); high-performance steel fiber-reinforced composite (HPSFRC); and hybrid fiber-reinforced composite (HyFRC). Two shear span-to-depth ratios (a/d = 0.75 and 1.0) are explored. The mechanical properties of the composites in terms of tensile, compressive, and flexural strengths are investigated. Next, the structural behaviour of the high-performance cementitious composite corbels in terms of ultimate load capacity, ductility, and failure modes under the three-point bending test are investigated. The secondary reinforcement is proven to significantly affect stiffness and ultimately load capacity of all three high-performance composite corbels with an aspect ratio of 0.75. However, the secondary reinforcement was more impactful for the HPSFRC corbels, with 51% increase of ultimate strength. Moreover, in terms of damage, fewer cracks occurred in ECC corbels. HPSFRC corbels displayed the highest level of ductility and deformation capacity compared to the other specimens. The results were comparatively analyzed against the predicted results using truss and plastic truss models which provided relatively reliable shear strength.
A Study of Second-Phase Precipitates and Dispersoid Particles in 2024 Aluminum Alloy after Different Aging Treatments
Authors: Staszczyk Anna , Sawicki Jacek , Adamczyk-Cieslak Boguslawa
Published: December 2019

Aluminum alloys such as AA2024 are popular in the automotive and aircraft industries. The application of artificial aging significantly improves their mechanical properties by precipitation hardening. However, commercial alloys very often contain different amounts of elements such as Si and Fe that make the evolution of the microstructure harder to control. Large intermetallic particles can influence the overall results of heat treatment and cause deterioration of material properties. The authors decided to examine changes in the microstructure of three commercial 2024 alloys with varying chemical compositions by applying three different types of aging treatments. The results show considerable differences in the amount, size and morphologies of the precipitates. Second-phase Al2Cu and Al2CuMg precipitates were identified in one of the alloys. Other interesting types of multiphase particles were discovered in alloys with higher Si contents. The results show that even small variations in the composition can lead to a completely different microstructure.
Reverse Problem in Surface Texture Analysis—One-Process Profile Modeling on the Basis of Measured Two-Process Profile after Machining or Wear
Authors: Pawlus Pawel , Reizer Rafal , Wieczorowski Michal
Published: December 2019

The method of the base (valley) one-process profile modeling on the basis of the measured two-process profile was developed. The base one-process random profile of the Gaussian ordinate distribution is characterized by the standard deviation of the profile height and the correlation length. The problem of estimation of the correlation length of this one-process profile exists. In the procedure of the correlation length estimation, information about the averaged shape of the autocorrelation functions of many one-process profiles after the same type of machining is required. The correlation length of the base one-process profile can be obtained on the basis of the vertical truncation of the measured two-process profile. The average error of the correlation length estimation was not higher than 7%, while the maximum error was not larger than 14%. This method can be extended to simulate the one-process texture of 3D (areal) surface topography.
Standard Hot Pressing as a Possible Solution to Obtain Dense K0.5Na0.5NbO3 Ceramic Doped by Er2O3 and Yb2O3
Authors: Rutkowski Paweł , Huebner Jan , Graboś Adrian , Kata Dariusz , Grzybek Dariusz , Sapiński Bogdan
Published: December 2019

In this study, the influence of the addition of rare earth oxides on the phase composition and density of KNN piezoelectric ceramics was investigated. The initial powders of Na2CO3 and K2CO3 were dried at 150 °C for 2 h. Then, a powder mixture for synthesis was prepared by adding a stoichiometric amount of Nb2O5 and 5 and 10 wt % overabundance of Na2CO3. All powders were mixed by ball-milling for 24 h and synthesized at 950 °C. The phase composition of the reaction bed was checked by means of X-ray diffraction (XRD). It had an appearance of tetragonal and monoclinic K0.5Na0.5NbO3 (KNN) phases. Then, 1 and 2 wt % of Er2O3 and Yb2O3, were added to the mixture. Green samples of 25 mm diameter and 3 mm thickness were prepared and sintered by hot pressing at 1000 °C for 2 h under 25 MPa pressure. The final samples were investigated via scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS), XRD, Rietveld, and ultrasonic methods. Phase analysis showed tetragonal and orthorhombic KNN phases, and a contamination of (K2CO3·1.5H2O) was present. The obtained KNN polycrystals had a relative density above 95%. Texturing of the material was confirmed as a result of hot pressing.
Effect of Travel Speed on Microstructure and Mechanical Properties of FSW Joints for Al–Zn–Mg Alloy
Authors: Lin Sen , Tang Jianguo , Liu Shengdan , Deng Yunlai , Lin Huaqiang , Ji Hua , Ye Lingying , Zhang Xinming
Published: December 2019

The microstructures and mechanical properties of friction stir welded (FSW) Al–Zn–Mg alloy plate under different travel speeds were investigated. Both the average grain sizes (AGSs) of the shoulder affected zone (SAZ), nugget zone (NZ), and the widths of thermo-mechanically affected zone (TMAZ) decreased with the increase of travel speed. Moreover, the AGSs of NZ are always about 60% of that of SAZ at different travel speeds. The fractions of high-angle grain boundaries (HAGBs) in the FSW joints reduce with the distance away from the stir zone (SZ). Furthermore, the initial η’ strengthening precipitates in NZ and TMAZ dissolve and GP zones form during subsequent natural aging, so that the hardness is similar in the two zones. The precipitate evolution in the heat-affected zone (HAZ) at hardness minima are affected by travel speeds, which induce the hardness minima and ultimate tensile strength (UTS) of FSW joints and increase with the increase of travel speed, and a fracture tends to occur at hardness minima location of HAZ during tensile testing.
Modeling of One-Side Surface Modifications of Graphene
Authors: Savin Alexander V. , Kosevich Yuriy A.
Published: December 2019

We model, with the use of the force field method, the dependence of mechanical conformations of graphene sheets, located on flat substrates, on the density of unilateral (one-side) attachment of hydrogen, fluorine or chlorine atoms to them. It is shown that a chemically-modified graphene sheet can take four main forms on a flat substrate: the form of a flat sheet located parallel to the surface of the substrate, the form of convex sheet partially detached from the substrate with bent edges adjacent to the substrate, and the form of a single and double roll on the substrate. On the surface of crystalline graphite, the flat form of the sheet is lowest in energy for hydrogenation density p < 0.21 , fluorination density p < 0.20 , and chlorination density p < 0.16 . For higher attachment densities, the flat form of the graphene sheet becomes unstable. The surface of crystalline nickel has higher adsorption energy for graphene monolayer and the flat form of a chemically modified sheet on such a substrate is lowest in energy for hydrogenation density p < 0.47 , fluorination density p < 0.30 and chlorination density p < 0.21 .
There Is a Future for N-Heterocyclic Carbene Iron(II) Dyes in Dye-Sensitized Solar Cells: Improving Performance through Changes in the Electrolyte
Authors: Karpacheva Mariia , Wyss Vanessa , Housecroft Catherine E. , Constable Edwin C.
Published: December 2019

By systematic tuning of the components of the electrolyte, the performances of dye-sensitized solar cells (DSCs) with an N-heterocyclic carbene iron(II) dye have been significantly improved. The beneficial effects of an increased Li+ ion concentration in the electrolyte lead to photoconversion efficiencies (PCEs) up to 0.66% for fully masked cells (representing 11.8% relative to 100% set for N719) and an external quantum efficiency maximum (EQEmax) up to approximately 25% due to an increased short-circuit current density (JSC). A study of the effects of varying the length of the alkyl chain in 1-alkyl-3-methylimidazolium iodide ionic liquids (ILs) shows that a longer chain results in an increase in JSC with an overall efficiency up to 0.61% (10.9% relative to N719 set at 100%) on going from n-methyl to n-butyl chain, although an n-hexyl chain leads to no further gain in PCE. The results of electrochemical impedance spectroscopy (EIS) support the trends in JSC and open-circuit voltage (VOC) parameters. A change in the counterion from I− to [BF4]− for 1-propyl-3-methylimidazolium iodide ionic liquid leads to DSCs with a remarkably high JSC value for an N-heterocyclic carbene iron(II) dye of 4.90 mA cm−2, but a low VOC of 244 mV. Our investigations have shown that an increased concentration of Li+ in combination with an optimized alkyl chain length in the 1-alkyl-3-methylimidazolium iodide IL in the electrolyte leads to iron(II)-sensitized DSC performances comparable with those of containing some copper(I)-based dyes.
Theoretical and Experimental Study of 13.4 kV/55 A SiC PiN Diodes with an Improved Trade-Off between Blocking Voltage and Differential On-Resistance
Authors: Liu Yuewei , Yang Ruixia , Wang Yongwei , Zhang Zhiguo , Deng Xiaochuan
Published: December 2019

In this paper, a 13.4 kV/55 A 4H-silicon carbide (SiC) PiN diode with a better trade-off between blocking voltage, differential on-resistance, and technological process complexity has been successfully developed. A multiple zone gradient modulation field limiting ring (MGM-FLR) for extremely high-power handling applications was applied and investigated. The reverse blocking voltage of 13.4 kV, close to 95% of the theoretical value of parallel plane breakdown voltage, was obtained at a leakage current of 10 μA for a 100 μm thick, lightly doped, 5 × 1014 cm−3 n-type SiC epitaxial layer. Meanwhile, a fairly low differential on-resistance of 2.5 mΩ·cm2 at 55 A forward current (4.1 mΩ·cm2 at a current density of 100 A/cm2) was calculated for the fabricated SiC PiN with 0.1 cm2 active area. The highest Baliga’s figure-of-merit (BFOM) of 72 GW/cm2 was obtained for the fabricated SiC PiN diode. Additionally, the dependence of the breakdown voltage on transition region width, number of rings in each zone, as well as the junction-to-ring spacing of SiC PiN diodes is also discussed. Our findings indicate that this proposed device structure is one potential candidate for an ultra-high voltage power system, and it represents an option to maximize power density and reduce system complexity.
Pharmaceutical Development and Safety Evaluation of a GMP-Grade Fucoidan for Molecular Diagnosis of Cardiovascular Diseases
Authors: Chauvierre Cédric , Aid-Launais Rachida , Aerts Joël , Chaubet Frédéric , Maire Murielle , Chollet Lucas , Rolland Lydia , Bonafé Roberta , Rossi Silvia , Bussi Simona , Cabella Claudia , Dézsi Laszlo , Fülöp Tamas , Szebeni Janos , Chahid Youssef , Zheng Kang H. , Stroes Erik S. G. , Le Guludec Dominique , Rouzet François , Letourneur Didier
Published: December 2019

The adhesion molecule P-selectin is present on the cell surface of both activated endothelium and activated platelets. The present study describes the pharmaceutical development, safety evaluation, and preclinical efficacy of a micro-dosed radiotracer. The macromolecular nanoscale assembly consisted of a natural compound made of a sulfated fucose-rich polysaccharides (fucoidan) and a radionuclide (technetium-99m) for the detection of P-selectin expression in cardiovascular diseases. After extraction and fractionation from brown seaweeds, the good manufacturing practice (GMP) production of a low molecular weight (LMW) fucoidan of 7 kDa was achieved and full physicochemical characterization was performed. The regulatory toxicology study in rats of the GMP batch of LMW fucoidan revealed no adverse effects up to 400 μg/kg (×500 higher than the expected human dose) and pseudoallergy was not seen as well. In a myocardial ischemia-reperfusion model in rats, the GMP-grade LMW fucoidan labeled with technetium-99m detected P-selectin upregulation in vivo. The present study supports the potential of using 99mTc-fucoidan as an imaging agent to detect activated endothelium in humans.
Investigation on Contact Heating of Aluminum Alloy Sheets in Hot Stamping Process
Authors: Geng Huicheng , Wang Yilin , Wang Zijian , Zhang Yisheng
Published: December 2019

Application of the hot stamping process on heat-treatable aluminum alloys effectively solves the problems of large springback and poor ductility during forming at room temperature, which expands the range of applications of aluminum alloys in the transportation industry. Sheet heating plays an important role in the hot stamping process, and increasing the heating rate can improve the hot stamping efficiency to some extent. In this paper, the feasibility of applying contact heating techniques with higher heating rates in the hot stamping process was studied. A contact heating device was designed, and the temperature distribution of the device contact surface was observed. Furthermore, the heating characteristics of 7075 aluminum alloy sheets during the contact heating process were explored by experiments and finite element simulation. Finally, the rapid solution treatment of aluminum alloy was carried out with a contact heating device, which was compared with the furnace heating solution treatment. The experimental and simulation results indicate that the device contact surface has a relatively uniform temperature distribution, and the aluminum alloy sheets can be heated to close to the set temperature in 15 s using contact heating techniques. Meanwhile, the rapid solution treatment of aluminum alloy sheets can be achieved within 15–20 s by contact heating techniques, obtaining superior mechanical properties. This suggests that the contact heating process can be used for rapid heating and rapid solution treatment of aluminum alloy sheets in hot stamping process.
Automatic Micro-Robotic Identification and Electrical Characterization of Graphene
Authors: Garnica B. Sergio A. , Knaust Marius , Fatikow Sergej
Published: December 2019

Micromechanically exfoliating graphene on S i / S i O 2 substrates is commonplace for graphene researchers, but locating actual graphene flakes on these substrates is a high-effort and tiresome task. The main purpose of this work was to establish a completely automated procedure to identify those graphene flakes with as little human interaction as possible, improving on the limitations of current methods. Furthermore, automatic electrical characterization of the identified flakes was performed. The proposed micro-robotic automation sequence consists of three main steps. To start, a sample surface plane is calculated, based on multiple foci points across the substrate. Secondly, flakes on the substrate are identified in the hue, saturation, and value (HSV) color space, with an implementation to fit the measurement probe, used to avoid undersized samples and adjust the flake orientation. Finally, electrical characterization is performed based on four point probe measurements with the Van der Pauw method. Results of the successfully implemented automation sequence are presented together with flake electrical properties and validation.