bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Clinical Trials of Nucleic Acid Medicines for Pancreatic Cancer Treatment
Authors: Yamakawa Keiko , Nakano-Narusawa Yuko , Hashimoto Nozomi , Yokohira Masanao , Matsuda Yoko
Published: August 2019

Approximately 30% of pancreatic cancer patients harbor targetable mutations. However, there has been no therapy targeting these molecules clinically. Nucleic acid medicines show high specificity and can target RNAs. Nucleic acid medicine is expected to be the next-generation treatment next to small molecules and antibodies. There are several kinds of nucleic acid drugs, including antisense oligonucleotides, small interfering RNAs, microRNAs, aptamers, decoys, and CpG oligodeoxynucleotides. In this review, we provide an update on current research of nucleic acid-based therapies. Despite the challenging obstacles, we hope that nucleic acid drugs will have a significant impact on the treatment of pancreatic cancer. The combination of genetic diagnosis using next generation sequencing and targeted therapy may provide effective precision medicine for pancreatic cancer patients.
Anti-Diabetic Countermeasures Against Tobacco Smoke-Dependent Cerebrovascular Toxicity: Use and Effect of Rosiglitazone
Authors: Sivandzade Farzane , Cucullo Luca
Published: August 2019

Tobacco smoking (TS) is one of the most addictive habit sand a main public health hazards, impacting the vascular endothelium through oxidative stress (OS) stimuli, exposure to nicotine, and smoking-induced inflammation in a dose-dependent manner. Increasing evidence also suggested that TS increases glucose intolerance and the risk factor of developing type-2 diabetes mellitus (2DM), which, along with TS, is connected to blood–brain barrier (BBB) injuries, and heightens the risk of cerebrovascular disorders. Although the exact mechanism of rosiglitazone (RSG) is unknown, our previous in vitro work showed how RSG, an oral anti-diabetic drug belonging to the family of thiazolidinedione class, can protect BBB integrity through enhancement of nuclear factor erythroid 2-related factor (Nrf2) activity. Herein, we have validated the protective role of rosiglitazone against TS-induced BBB impairment in vivo. Our results revealed that RSG as a peroxisome proliferator-activated receptor gamma (PPARγ), activates counteractive mechanisms primarily associated with the upregulation of Nrf2 and PPARγ pathways which reduce TS-dependent toxicity at the cerebrovascular level. In line with these findings, our results show that RSG reduces inflammation and protects BBB integrity. In conclusion, RSG offers a novel and promising therapeutic application to reduce TS-induced cerebrovascular dysfunction through activation of the PPARγ-dependent and/or PPARγ-independent Nrf2 pathway.
Kaempferia parviflora Extract Inhibits STAT3 Activation and Interleukin-6 Production in HeLa Cervical Cancer Cells
Authors: Suradej Benjamart , Sookkhee Siriwoot , Panyakaew Jukreera , Mungkornasawakul Pitchaya , Wikan Nitwara , Smith Duncan R. , Potikanond Saranyapin , Nimlamool Wutigri
Published: August 2019

Kaempferia parviflora (KP) has been reported to have anti-cancer activities. We previously reported its effects against cervical cancer cells and continued to elucidate the effects of KP on inhibiting the production and secretion of interleukin (IL)-6, as well as its relevant signaling pathways involved in cervical tumorigenesis. We discovered that KP suppressed epidermal growth factor (EGF)-induced IL-6 secretion in HeLa cells, and it was associated with a reduced level of Glycoprotein 130 (GP130), phosphorylated signal transducers and activators of transcription 3 (STAT3), and Mcl-1. Our data clearly showed that KP has no effect on nuclear factor kappa B (NF-κB) localization status. However, we found that KP inhibited EGF-stimulated phosphorylation of tyrosine 1045 and tyrosine 1068 of EGF receptor (EGFR) without affecting its expression level. The inhibition of EGFR activation was verified by the observation that KP significantly suppressed a major downstream MAP kinase, ERK1/2. Consistently, KP reduced the expression of Ki-67 protein, which is a cellular marker for proliferation. Moreover, KP potently inhibited phosphorylation of STAT3, Akt, and the expression of Mcl-1 in response to exogenous IL-6 stimulation. These data suggest that KP suppresses EGF-induced production of IL-6 and inhibits its autocrine IL-6/STAT3 signaling critical for maintaining cancer cell progression. We believe that KP may be a potential alternative anti-cancer agent for suppressing cervical tumorigenesis.
Development of SpyTag/SpyCatcher-Bacmid Expression Vector System (SpyBEVS) for Protein Bioconjugations Inside of Silkworms
Authors: Xu Jian , Kato Tatsuya , Park Enoch Y.
Published: August 2019

Protein conjugations at post-translational levels are known to be essential to protein stability and function. Recently, it has been proven that the split protein CnaB2 (SpyTag/SpyCatcher, ST/SC) from Streptococcus pyogenes can induce covalent conjugation rapidly and efficiently under various conditions. The protein of interest fused with the split protein SC/ST could be assembled spontaneously. In light of this finding, we introduced the ST/SC protein coupling concept into the silkworm-bacmid protein expression system (SpyBEVS). As a proof of concept, we first examined and confirmed that a competent ligation occurred between ST/SC-fused protein partners in vitro in cultured silkworm cells and in vivo in silkworm larvae by co-infection of several recombinant baculoviruses. The protein conjugation could be also achieved sufficiently by a simple one-step mixture of purified ST/SC-tagged peptide-protein pairs in vitro. Given the flexibility and robustness of silkworm-BEVS, our results on SpyBEVS show an alternative method for enabling the production of protein decorations in vitro and inside of silkworms.
Comparative Quantitative Analysis of Porcine Optic Nerve Head and Retina Subproteomes
Authors: Funke Sebastian , Schmelter Carsten , Markowitsch Sascha D. , Perumal Natarajan , Heyne Janis C. , Bell Katharina , Pfeiffer Norbert , Grus Franz H.
Published: August 2019

Optic nerve head (ONH) and retina (RET) are the main sites of damage in neurodegenerative optic neuropathies including glaucoma. Up to date, little is known about the molecular interplay between these two adjoining ocular components in terms of proteomics. To close this gap, we investigated ONH and RET protein extracts derived from porcine eyes (n = 12) (Sus scrofa domestica Linnaeus 1758) using semi-quantitative mass spectrometry (MS)-based proteomics comprising bottom-up LC–ESI MS/MS and targeted SPE-MALDI-TOF MS analysis. In summary, more than 1600 proteins could be identified from the ONH/RET tissue complex. Moreover, ONH and RET displayed tissue-specific characteristics regarding their qualitative and semi-quantitative protein compositions. Gene ontology (GO)-based functional and protein–protein interaction analyses supported a close functional connection between the metabolic-related RET and the structural-associated ONH subproteomes, which could be affected under disease conditions. Inferred from the MS findings, stress-associated proteins including clusterin, ceruloplasmin, and endoplasmin can be proposed as extracellular mediators of the ONH/ RET proteome interface. In conclusion, ONH and RET show obvious proteomic differences reflecting characteristic functional features which have to be considered for future protein biomarker profiling studies.
Immunotherapy-Based Targeting and Elimination of Leukemic Stem Cells in AML and CML
Authors: Valent Peter , Sadovnik Irina , Eisenwort Gregor , Bauer Karin , Herrmann Harald , Gleixner Karoline V. , Schulenburg Axel , Rabitsch Werner , Sperr Wolfgang R. , Wolf Dominik
Published: August 2019

The concept of leukemic stem cells (LSC) has been developed with the idea to explain the clonal hierarchies and architectures in leukemia, and the more or less curative anti-neoplastic effects of various targeted drugs. It is now widely accepted that curative therapies must have the potential to eliminate or completely suppress LSC, as only these cells can restore and propagate the malignancy for unlimited time periods. Since LSC represent a minor cell fraction in the leukemic clone, little is known about their properties and target expression profiles. Over the past few years, several cell-specific immunotherapy concepts have been developed, including new generations of cell-targeting antibodies, antibody–toxin conjugates, bispecific antibodies, and CAR-T cell-based strategies. Whereas such concepts have been translated and may improve outcomes of therapy in certain lymphoid neoplasms and a few other malignancies, only little is known about immunological targets that are clinically relevant and can be employed to establish such therapies in myeloid neoplasms. In the current article, we provide an overview of the immunologically relevant molecular targets expressed on LSC in patients with acute myeloid leukemia (AML) and chronic myeloid leukemia (CML). In addition, we discuss the current status of antibody-based therapies in these malignancies, their mode of action, and successful examples from the field.
Recent Insights from Molecular Dynamics Simulations for G Protein-Coupled Receptor Drug Discovery
Authors: Zou Ye , Ewalt John , Ng Ho-Leung
Published: August 2019

G protein-coupled receptors (GPCRs) are critical drug targets. GPCRs convey signals from the extracellular to the intracellular environment through G proteins. Some ligands that bind to GPCRs activate different downstream signaling pathways. G protein activation, or β-arrestin biased signaling, involves ligands binding to receptors and stabilizing conformations that trigger a specific pathway. β-arrestin biased signaling has become a hot target for structure-based drug discovery. However, challenges include that there are few crystal structures available in the Protein Data Bank and that GPCRs are highly dynamic. Hence, molecular dynamics (MD) simulations are especially valuable for obtaining detailed mechanistic information, including identification of allosteric sites and understanding modulators’ interactions with receptors and ligands. Here, we highlight recent MD simulation studies and enhanced sampling methods used to study biased G protein-coupled receptor signaling and their conformational dynamics as well as applications to drug discovery.
Geographic and Ecological Dimensions of Host Plant-Associated Genetic Differentiation and Speciation in the Rhagoletis cingulata (Diptera: Tephritidae) Sibling Species Group
Authors: Doellman Meredith M. , Schuler Hannes , Jean Saint Gilbert , Hood Glen R. , Egan Scott P. , Powell Thomas H.Q. , Glover Mary M. , Bruzzese Daniel J. , Smith James J. , Yee Wee L. , Goughnour Robert B. , Rull Juan , Aluja Martin , Feder Jeffrey L.
Published: August 2019

Ascertaining the causes of adaptive radiation is central to understanding how new species arise and come to vary with their resources. The ecological theory posits adaptive radiation via divergent natural selection associated with novel resource use; an alternative suggests character displacement following speciation in allopatry and then secondary contact of reproductively isolated but ecologically similar species. Discriminating between hypotheses, therefore, requires the establishment of a key role for ecological diversification in initiating speciation versus a secondary role in facilitating co-existence. Here, we characterize patterns of genetic variation and postzygotic reproductive isolation for tephritid fruit flies in the Rhagoletis cingulata sibling species group to assess the significance of ecology, geography, and non-adaptive processes for their divergence. Our results support the ecological theory: no evidence for intrinsic postzygotic reproductive isolation was found between two populations of allopatric species, while nuclear-encoded microsatellites implied strong ecologically based reproductive isolation among sympatric species infesting different host plants. Analysis of mitochondrial DNA suggested, however, that cytoplasmic-related reproductive isolation may also exist between two geographically isolated populations within R cingulata. Thus, ecology associated with sympatric host shifts and cytoplasmic effects possibly associated with an endosymbiont may be the key initial drivers of the radiation of the R. cingulata group.
Inappropriateness of Repeated Laboratory and Radiological Tests for Transferred Emergency Department Patients
Authors: Bertrand Jérôme , Fehlmann Christophe , Grosgurin Olivier , Sarasin François , Kherad Omar
Published: August 2019

Background: Laboratory and radiographic tests are often repeated during inter-hospital transfers from secondary to tertiary emergency departments (ED), despite available data from the sending structure. The aim of this study was to identify the proportion of repeated tests in patients transferred to a tertiary care ED, and to estimate their inappropriateness and their costs. Methods: A retrospective chart review of all adult patients transferred from one secondary care ED to a tertiary care ED during the year 2016 was carried out. The primary outcome was the redundancy (proportion of procedure repeated in the 8 h following the transfer, despite the availability of the previous results). Factors predicting the repetition of procedures were identified through a logistic regression analysis. Two authors independently assessed inappropriateness. Results: In 2016, 432 patients were transferred from the secondary to the tertiary ED, and 251 procedures were repeated: 179 patients (77.2%) had a repeated laboratory test, 34 (14.7%) a repeated radiological procedure and 19 (8.2%) both. Repeated procedures were judged as inappropriate for 197 (99.5%) laboratory tests and for 39 (73.6%) radiological procedures. Conclusion: Over half of the patients transferred from another emergency department had a repeated procedure. In most cases, these repeated procedures were considered inappropriate.
Temperature- and Time-Dependent Mechanical Behavior of Post-Treated IN625 Alloy Processed by Laser Powder Bed Fusion
Authors: Kreitcberg Alena , Inaekyan Karine , Turenne Sylvain , Brailovski Vladimir
Published: August 2019

The microstructure and mechanical properties of IN625 alloy processed by laser powder bed fusion (LPBF) and then subjected to stress relief annealing, high temperature solution treatment, and hot isostatic pressing were studied. Tensile testing to failure was carried out in the 25–871 °C temperature range. Creep testing was conducted at 760 °C under 0.5–0.9 yield stress conditions. The results of the present study provided valuable insights into the static and creep properties of LPBF IN625 alloy, as compared to a wrought annealed alloy of similar composition. It was shown that at temperatures below 538 °C, the mechanical resistance and elongation to failure of the LPBF alloy were similar to those of its wrought counterpart, whereas at higher temperatures, the elongation to failure of the LPBF alloy became significantly lower than that of the wrought alloy. The solution-treated LPBF alloy exhibited significantly improved creep properties at 760 °C as compared to the wrought annealed alloy, especially under intermediate and low levels of stress.
Effect of Ultrasonic Parameters on Electrochemical Chloride Removal and Rebar Repassivation of Reinforced Concrete
Authors: Liu Qingyang , Song Zijian , Cai Huanchun , Zhou Aiping , Wang Wanyi , Jiang Linhua , Liu Yongqi , Zhang Yingjie , Xu Na
Published: August 2019

Electrochemical chloride removal (ECR) from reinforced concrete can be considered as an environment-friendly technique since it can reduce the environmental issues arising from demolition and reconstruction. In this study, we used ultrasonic waves to promote the ECR efficiency without increasing the current density so as to shorten the overall power-on time, lowering the power consumption and electricity-induced material damage. Rebar-embedded cement mortar specimens were prepared and a set of ultrasonic-assisted ECR test devices was designed. For obtaining the optimal parameters, different ultrasonic frequencies and powers were adopted to conduct the ECR test. After that, the discharged and residual chloride ion amounts were detected to characterize the ECR efficiency. The corrosion behavior of rebar was characterized by electrochemical method. It was found that ultrasonic waves can not only promote the discharge of chloride ions, but also promote the passivation process of steel bar. For this investigation, the ultrasonic waves with a frequency of 40 Hz and a power of 60 W had the best auxiliary effect and could reduce the work time by 64%. It is considered that the ultrasound-assisted method has potential to promote the application possibilities of the ECR technique.
Effects of Substrate-Coating Materials on the Wound-Healing Process
Authors: Lin Jin-Young , Lo Kai-Yin , Sun Yung-Shin
Published: August 2019

The wound-healing assay is commonly and widely used for investigating collective cell migration under various physical and chemical stimuli. Substrate-coating materials are shown to affect the wound-healing process in a cell-type dependent manner. However, experiment-to-experiment variations make it difficult to compare results from different assays. In this paper, a modified barrier wound-healing assay was reported for studying the wound-healing process on different substrates in one single petri dish. In short, half of a dish was covered with the tape, and coating materials, poly-l-lysine and gelatin, were applied to the surface. After peeling off the tape, half of the surface was coated with the desired material. Then a customized barrier was placed inside the dish to create the wound. The results indicated that surface coating did not affect cell proliferation/viability, and the wound-healing rate increased in coated surfaces compared to uncoated ones. The present study provides a platform for further understanding the mechanisms of substrate coating-dependent wound-healing processes.
Stochastic Finite Element Analysis Framework for Modelling Mechanical Properties of Particulate Modified Polymer Composites
Authors: Ahmadi Moghaddam Hamidreza , Mertiny Pierre
Published: August 2019

Polymers have become indispensable in many engineering applications because of their attractive properties, including low volumetric mass density and excellent resistance to corrosion. However, polymers typically lack in mechanical, thermal, and electrical properties that may be required for certain engineering applications. Therefore, researchers have been seeking to improve properties by modifying polymers with particulate fillers. In the research presented herein, a numerical modeling framework was employed that is capable of predicting the properties of binary or higher order composites with randomly distributed fillers in a polymer matrix. Specifically, mechanical properties, i.e., elastic modulus, Poisson’s ratio, and thermal expansion coefficient, were herein explored for the case of size-distributed spherical filler particles. The modeling framework, employing stochastic finite element analysis, reduces efforts for assessing material properties compared to experimental work, while increasing the level of accuracy compared to other available approaches, such as analytical methods. Results from the modeling framework are presented and contrasted with findings from experimental works available in the technical literature. Numerical predictions agree well with the non-linear trends observed in the experiments, i.e., elastic modulus predictions are within the experimental data scatter, while numerical data deviate from experimental Poisson’s ratio data for filler volume fractions greater than 0.15. The latter may be the result of morphology changes in specimens at higher filler volume fractions that do not comply with modelling assumptions.
Microstructure and Properties of Ni–Co Composite Cladding Coating on Mould Copper Plate
Authors: Liu Yu , Liu Ying , Gao Yali , Dong Chao , Wang Shoubo
Published: August 2019

In this study, a Ni–Co composite coating was fabricated successively on a copper substrate by laser, and the microstructure and properties of the composite coating were studied. Our results show that the elements from Ni and Co alloy powder were uniformly distributed in the binding region, which obtained a good metallurgical bonding with the substrate. The microhardness of Co-based coatings was 646 HV0.1, which was approximately 7.6 times greater than the hardness of Cu substrate. The Ni-based coating hardness was a little lower than that of the Co-based coating, which was approximately 7.0 times higher than the hardness of Cu substrate. The Co-based coating was comprised of reinforced phases, such as Co, Ni–Cr–Co–Mo, M7C3 and {Fe, Ni}. The wear volume of Co-based coatings was approximately 0.164 mm3 after the sliding wear test at 60 min, which was only 4% of the substrate’s wear volume. Meanwhile, the heat shock resistance experiment was carried out at 800 °C for 75 times before the Ni–Co composite coating was peeled off. It was shown that this Ni–Co composite coating had good wear resistance and high temperature properties, which is helpful to improve the service life of a mould copper plate. It not only saves the economic cost of steel plants, but also improves the quality of slabs and products.
Pure Mandibular Incisor Intrusion: A Finite Element Study to Evaluate the Segmented Arch Technique
Authors: de Brito Gabriela Meyge , Brito Hélio Henrique de Araújo , Marra Gabriel Goulart Mendes , Freitas Laíze Rosa Pires , Hargreaves Bernardo Oliveira , Magalhães Pedro Américo Almeida , Oliveira Dauro Douglas
Published: August 2019

Leveling the curve of Spee is a commonly-used strategy to correct deep bites. Although several techniques have been proposed to intrude mandibular incisors (MI), flaring of these teeth is often observed and in many instances undesired. A three-dimensional (3D) finite element model (FEM) was used to locate the ideal point of force application (PFA) to achieve pure MI intrusion with the three-piece arches’ technique. It comprised (1) a 0.021 × 0.025 in. stainless steel (SS) wire that passively filled the slots of the canine and premolar brackets and the first and second molar tubes, bilaterally; (2) a 0.0215 × 0.0275 in. SS intrusion base arch (IBA) inserted into the MI brackets, that presented a step down distal to the lateral incisors brackets and a posterior extension arm; (3) titanium-molybdenum tip-back springs designed to apply the intrusion force, fitted inside the first molar gingival tube. Four PFA on the IBA were simulated (FEM 1, 2, 3, and 4). FEM 3 resulted in pure MI and was considered the ideal PFA. FEM1 and 2 showed intrusion and buccal crown flaring of the MI, whereas FEM4 resulted in intrusion and lingual crown flaring of those teeth. Clinicians may consider three-piece arch mechanics to achieve pure MI intrusion. However, they must be aware that when force was applied anteriorly or posteriorly to the ideal PFA, the incisors would incline labially or lingually, respectively.
Kinetics of Zinc Corrosion in Concrete as a Function of Water and Oxygen Availability
Authors: Pokorný Petr , Kouřil Milan , Kučera Vojtěch
Published: August 2019

This paper studies the effect of water as an oxidation agent and also of oxygen on zinc corrosion kinetics in active state in concrete, using high-sensitivity electrical resistance sensors. It was proven that zinc corrosion in active state is strongly affected by the presence of water at its surface. Zinc corrosion in real concrete in the absence of water can be misinterpreted as salt passivity. The presence of oxygen results in an increase of zinc corrosion rate, however at pH 12.6, passivity can occur. It was verified that corrosion products consisting primarily of Ca[Zn(OH)3]2·2H2O cannot effectively passivate zinc surface in concrete, even after 1800 h of exposure and zinc, or hot-dip galvanized steel can corrode at an unacceptable corrosion rate (more than 4 µm·a−1).
Penigrisacids A–D, Four New Sesquiterpenes from the Deep-Sea-Derived Penicillium griseofulvum
Authors: Xing Cui-Ping , Xie Chun-Lan , Xia Jin-Mei , Liu Qing-Mei , Lin Wei-Xiang , Ye De-Zan , Liu Guang-Ming , Yang Xian-Wen
Published: August 2019

Four new (penigrisacids A–D, 1–4) and one known (5) carotane sesquiterpenoids were isolated from the deep-sea-derived fungus Penicillium griseofulvum, along with four known compounds (6–9). The planar structures and relative configurations of the new compounds were determined by extensive analysis of the NMR and HRESIMS data. The absolute configurations were established by comparison of the experimental and calculated ECD (electronic circular dichroism) spectra or OR (optical rotation) value. Compound 9 exhibited potent anti-food allergic activity with IC50 value of 28.7 μM, while 4 showed weak cytotoxicity against ECA-109 tumor cells (IC50 = 28.7 μM).
Worms’ Antimicrobial Peptides
Authors: Bruno Renato , Maresca Marc , Canaan Stéphane , Cavalier Jean-François , Mabrouk Kamel , Boidin-Wichlacz Céline , Olleik Hamza , Zeppilli Daniela , Brodin Priscille , Massol François , Jollivet Didier , Jung Sascha , Tasiemski Aurélie
Published: August 2019

Antimicrobial peptides (AMPs) are natural antibiotics produced by all living organisms. In metazoans, they act as host defense factors by eliminating microbial pathogens. But they also help to select the colonizing bacterial symbionts while coping with specific environmental challenges. Although many AMPs share common structural characteristics, for example having an overall size between 10–100 amino acids, a net positive charge, a γ-core motif, or a high content of cysteines, they greatly differ in coding sequences as a consequence of multiple parallel evolution in the face of pathogens. The majority of AMPs is specific of certain taxa or even typifying species. This is especially the case of annelids (ringed worms). Even in regions with extreme environmental conditions (polar, hydrothermal, abyssal, polluted, etc.), worms have colonized all habitats on Earth and dominated in biomass most of them while co-occurring with a large number and variety of bacteria. This review surveys the different structures and functions of AMPs that have been so far encountered in annelids and nematodes. It highlights the wide diversity of AMP primary structures and their originality that presumably mimics the highly diverse life styles and ecology of worms. From the unique system that represents marine annelids, we have studied the effect of abiotic pressures on the selection of AMPs and demonstrated the promising sources of antibiotics that they could constitute.
Analysis on Electromagnetic Field of Continuous Casting Mold Including a New Integral Method for Calculating Electromagnetic Torque
Authors: Li Shaoxiang , Xiao Hong , Wang Pu , Liu Huasong , Zhang Jiaquan
Published: August 2019

Based on the Maxwell’s equations, a finite element model is established to study the characteristics of electromagnetic field in the mold of billet and bloom continuous casting with electromagnetic stirring (M-EMS). A novel integral method for calculating electromagnetic torque is proposed to evaluate the stirring intensity of stirrer. In order to verify the accuracy of the model, a well-designed electromagnetic torque detecting device is fabricated. The predicted value of electromagnetic torque and magnetic flux density are consistent with the measured data. The optimum frequency is determined by the maximal electromagnetic torque of the strand. The effect of stirring current intensity and different stirrer positions along the length of mold on the electromagnetic field has been studied numerically. The results show that the optimum frequency is smaller when the copper tube of the mold is thicker and the section size is bigger. Besides, the electromagnetic torque of the strand is a quadratic function of the running current intensity. Moreover, the installation position of stirrer strongly affects the prediction of electromagnetic field distribution, further influencing the optimum frequency and the electromagnetic torque of strand.
The Effects of Recrystallization on Strength and Impact Toughness of Cold-Worked High-Mn Austenitic Steels
Authors: Park Minha , Kang Moon Seok , Park Geon-Woo , Choi Eun Young , Kim Hyoung-Chan , Moon Hyoung-Seok , Jeon Jong Bae , Kim Hyunmyung , Kwon Se-Hun , Kim Byung Jun
Published: August 2019

High-Mn austenitic steels have been recently developed for a storage or transportation application of liquefied natural gas (LNG) in cryogenic fields. Since the structural materials are subjected to extremely low temperature, it requires excellent mechanical properties such as high toughness strength. In case of high-Mn steels, twinning deformation during the cold-working process is known to increase strength yet may cause embrittlement of heavy deformed twin and anisotropic properties. In this study, a recrystallization process through appropriate annealing heat treatments after cold-working was applied to improve the impact toughness for high-Mn austenitic steels. Microstructure and mechanical properties were performed to evaluate the influence of cold-worked and annealed high-Mn austenitic steels. Mechanical properties, such as strength and impact toughness, were investigated by tensile and Charpy impact tests. The relationship between strength and impact toughness was determined by microstructure analysis such as the degree of recrystallization and grain refinement. Consequently, both elongation and toughness were significantly increased after cold-working and subsequent annealing at 1000 °C as compared to the as-received (hot-rolled) specimen. The cold-worked high-Mn steel was completely recrystallized at 1000 °C and showed a homogeneous micro-structure with high-angle grain boundaries.
A Silicon Resonant Accelerometer Embedded in An Isolation Frame with Stress Relief Anchor
Authors: Cui Jian , Yang Haibing , Li Dong , Song Ziyang , Zhao Qiancheng
Published: August 2019

Bias thermal sensitivity is a significant performance parameter of a silicon resonant accelerometer (SRA) and is normally used to evaluate the degree of engineering practicability. Theoretical analysis demonstrates that temperature-induced stress is the dominant factor that determines the bias temperature drift of the custom-designed SRA. To solve this issue, this paper presents an SRA embedded in an isolation frame with stress insensitive anchor that prevents the resonant beams suffering from the thermal stress along the sense axis and thus improving the bias stability. Moreover, a high sensitivity device is achieved by integrating the vibrating beams with the comb fingers without conventional additional mass design. The experimental results show that the nominal resonant frequency of the SRA is around 93 kHz with the sensitivity and nonlinearity of 223.7 Hz/g and 5.1‰. The thermal sensitivities of the two resonant beams are −27.6 ppm/°C and −28.8 ppm/°C, respectively, which can be considered as the results owing to temperature change of the Young’s modulus without the thermal stress effect. The bias thermal sensitivity and the stability (1σ) after compensation are tested to be approximately 0.7 mg/°C and 1 mg over the temperature range from −40 °C to 60 °C with ±80 g measurement range.
Using Micromachined Molds, Partial-curing PDMS Bonding Technique, and Multiple Casting to Create Hybrid Microfluidic Chip for Microlens Array
Authors: Chen Pin-Chuan , Zhang Ren-Hao , Chen Liang-Ta
Published: August 2019

In a previous study, we presented a novel manufacturing process for the creation of 6 × 6 and 8 × 8 microlens arrays (MLAs) comprising lenses with diameters of 1000 μm, 500 μm, and 200 μm within an area that covers 10 mm × 10 mm. In the current study, we revised the manufacturing process to allow for the fabrication of MLAs of far higher density (15 × 15 and 29 × 29 within the same area). In this paper, we detail the revised manufacturing scheme, including the micromachining of molds, the partial-curing polydimethylsiloxane (PDMS) bonding used to fuse the glass substrate and PDMS, and the multi-step casting process. The primary challenges that are involved in creating MLAs of this density were ensuring uniform membrane thickness and preventing leakage between the PDMS and glass substrate. The experiment results demonstrated that the revised fabrication process is capable of producing high density arrays: Design I produced 15 × 15 MLAs with lens diameter of 0.5 mm and fill factor of 47.94%, while Design II produced 29 × 29 MLAs with lens diameter of 0.25 mm and fill factor of 40.87%. The partial-curing PDMS bonding system also proved to be effective in fusing PDMS with glass (maximum bonding strength of approximately six bars). Finally, the redesigned mold was used to create PDMS membranes of high thickness uniformity (coefficient of variance <0.07) and microlenses of high lens height uniformity (coefficient of variance <0.15).
Simulation and Experimental Study on the Surface Generation Mechanism of Cu Alloys in Ultra-Precision Diamond Turning
Authors: Zhang Quanli , Guo Nan , Chen Yan , Fu Yucan , Zhao Qingliang
Published: August 2019

The surface generation mechanism of the Cu alloys in ultra-precision diamond turning is investigated by both simulation and experimental methods, where the effects of the cutting parameters on the surface characteristics are explored, including the workpiece spindle speed, the cutting depth, the feed rate and the nose radius of the diamond tool. To verify the built model, the cutting experiments are conducted at selected parameters, where the causes of the error between the simulation and the machining results are analyzed, including the effects of the materials microstructure and the diamond tool wear. In addition, the nanometric surface characteristics of the Cu alloys after the diamond turning are identified, including the finer scratching grooves caused by the tool wear, the formation of the surface burs and the adhesion of graphite. The results show that the built model can be basically used to predict the surface topography for the selection of the appropriate machining parameters in the ultra-precision diamond turning process.
Staphylococcus aureus and the Cutaneous Microbiota Biofilms in the Pathogenesis of Atopic Dermatitis
Authors: Di Domenico Enea Gino , Cavallo Ilaria , Capitanio Bruno , Ascenzioni Fiorentina , Pimpinelli Fulvia , Morrone Aldo , Ensoli Fabrizio
Published: August 2019

Biofilm is the dominant mode of growth of the skin microbiota, which promotes adhesion and persistence in the cutaneous microenvironment, thus contributing to the epidermal barrier function and local immune modulation. In turn, the local immune microenvironment plays a part in shaping the skin microbiota composition. Atopic dermatitis (AD) is an immune disorder characterized by a marked dysbiosis, with a sharp decline of microbial diversity. During AD flares biofilm-growing Staphylococcus aureus emerges as the major colonizer in the skin lesions, in strict association with disease severity. The chronic production of inflammatory cytokines in the skin of AD individuals concurs at supporting S. aureus biofilm overgrowth at the expense of other microbial commensals, subverting the composition of the healthy skin microbiome. The close relationship between the host and microbial biofilm resident in the skin has profound implications on human health, making skin microbiota an attractive target for the therapeutic management of different skin disorders.
Glendonite-Like Carbonate Aggregates from the Lower Ordovician Koporye Formation (Russian Part of the Baltic Klint): Detailed Mineralogical and Geochemical Data and Paleogeographic Implications
Authors: Mikhailova Kseniia , Vasileva Kseniia , Fedorov Petr , Ershova Victoria , Vereshchagin Oleg , Rogov Mikhail , Pokrovsky Boris
Published: August 2019

Stellate and plate-like carbonate bodies, traditionally called anthraconites, are found throughout the Baltic-Ladoga Klint in bituminous shale of the Koporye Formation (Tremadocian, Lower Ordovician). Although this time interval is usually considered as a greenhouse, there is some evidence for the existence of at least temporary cold conditions during the Cambrian–Ordovician. However, the origin of anthraconites is still strongly debated. We studied the mineralogical, petrographic, cathodoluminescence, geochemical, and isotopic characteristics of anthraconites from five sections of the Russian part of the Baltic paleobasin. A close similarity between the morphological, petrographic, cathodoluminescence, and isotopic characteristics of the studied anthraconites with those of glendonites allow us to suggest that these bodies formed in a similar paleo-environment and should be considered as pseudomorphs of the mineral ikaite. The oxygen and carbon isotope ratios reveal that ikaite precipitation occurred in low-temperature conditions on the seafloor. The carbon isotopic values reveal influence of inorganic seawater carbon along with organic matter decomposition and/or methane oxidation during ikaite-glendonite transformations. The oxygen isotopic composition significantly changed after deposition due to meteoric diagenesis. We propose that the studied Tremadocian anthraconites formed under a region of upwelling, where cold phosphate-rich deep waters rose to the relatively shallow part of the Baltic paleobasin, providing favorable conditions for ikaite precipitation. Based on our cathodoluminescence study, we suggest that ikaite was transformed to calcite over several stages during diagenesis. Mineralogical studies also reveal that primary calcite was transformed to sulfate (gypsum) or dolomite during late superimposed processes.
Development of the Tumor-Specific Antigen-Derived Synthetic Peptides as Potential Candidates for Targeting Breast and Other Possible Human Carcinomas
Authors: Okarvi Subhani M. , AlJammaz Ibrahim
Published: August 2019

The human epidermal growth factor receptor 2 (HER2) represents one of the most studied tumor-associated antigens for cancer immunotherapy. The receptors for HER2 are overexpressed in various human cancers, such as breast and ovarian cancer. The relatively low expression of this antigen on normal tissues makes it a clinically useful molecular target for tumor imaging and targeted therapy. HER2 overexpression is correlated with aggressive tumor behavior and poor clinical outcomes. Thus, HER2 has become an important prognostic and predictive factor, as well as a potential molecular target. Due to the heterogeneity of breast cancer and possible discordance in HER2 status between primary tumors and distant metastases, assessment of HER2 expression by noninvasive imaging is important. Molecular imaging of HER2 expression may provide essential prognostic and predictive information concerning disseminated cancer and aid in the selection of an optimal therapy. Another tumor-specific antigen is MUC1, which is silent on normal tissues, but overexpressed in almost all human epithelial cell cancers, including >90% of human breast, ovarian, pancreatic, colorectal, lung, prostate, and gastric cancers and is a promising tumor antigen with diagnostic as well as the therapeutic potential of cancer. Radiolabeled small peptide ligands are attractive as probes for molecular imaging, as they reach and bind the target receptor efficiently and clear from blood and non-target organs faster than bulky antibodies. In this study, HER2 and MUC1-based peptides were synthesized and preclinically evaluated in an effort to develop peptide-based SPECT radiopharmaceuticals derived from tumor-associated antigens for the detection of breast cancer. Our findings demonstrate that the tumor antigen peptides radiolabeled efficiently with 99mTc and showed high metabolic stability in human plasma in vitro. The data from breast tumor cell binding confirmed the high affinity (in low nanomolar range) towards respective breast cancer cell lines. In healthy mice, 99mTc-labeled peptides displayed favorable pharmacokinetics, with high excretion by the renal system. In tumor xenografts nude mice models, good uptake by the SKBR3, MCF7, and T47D tumors were found, with good tumor-to-blood and tumor to muscle ratios. Additionally, tumor lesions can be seen in γ-camera imaging. Our data suggest that based on its ability to detect HER2- and MUC1-positive breast cancer cells in vivo, 99mTc-HER2 and 99mTc-MUC1-targeted peptides may be promising tumor imaging probes and warrant further investigation.
Nanocellulose-Reinforced Polyurethane for Waterborne Wood Coating
Authors: Kong Linglong , Xu Dandan , He Zaixin , Wang Fengqiang , Gui Shihan , Fan Jilong , Pan Xiya , Dai Xiaohan , Dong Xiaoying , Liu Baoxuan , Li Yongfeng
Published: August 2019

With the enhancement of people’s environmental awareness, waterborne polyurethane (PU) paint—with its advantages of low release of volatile organic compounds (VOCs), low temperature flexibility, acid and alkali resistance, excellent solvent resistance and superior weather resistance—has made its application for wood furniture favored by the industry. However, due to its lower solid content and weak intermolecular force, the mechanical properties of waterborne PU paint are normally less than those of the traditional solvent-based polyurethane paint, which has become the key bottleneck restricting its wide applications. To this end, this study explores nanocellulose derived from biomass resources by the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation method to reinforce and thus improve the mechanical properties of waterborne PU paint. Two methods of adding nanocellulose to waterborne PU—chemical addition and physical blending—are explored. Results show that, compared to the physical blending method, the chemical grafting method at 0.1 wt% nanocellulose addition results in the maximum improvement of the comprehensive properties of the PU coating. With this method, the tensile strength, elongation at break, hardness and abrasion resistance of the waterborne PU paint increase by up to 58.7%, ~55%, 6.9% and 3.45%, respectively, compared to the control PU; while the glossiness and surface drying time were hardly affected. Such exploration provides an effective way for wide applications of water PU in the wood industry and nanocellulose in waterborne wood coating.
Isothiocyanate-Functionalized Mesoporous Silica Nanoparticles as Building Blocks for the Design of Nanovehicles with Optimized Drug Release Profile
Authors: Martínez-Edo Gabriel , Llinàs Maria C. , Borrós Salvador , Sánchez-García David
Published: August 2019

A straightforward methodology for the synthesis of isothiocyanate-functionalized mesoporous silica nanoparticles (MSNs) by exposure of aminated MSNs to 1,1′-thiocarbonyldi-2(1H)-pyridone is reported. These nanoparticles are chemically stable, water tolerant, and readily react with primary amines without the formation of any by-product. This feature allows the easy modification of the surface of the nanoparticles for tuning their physical properties and the introduction of gatekeepers on the pore outlets. As a proof-of-concept, amino-isothiocyanate-functionalized MSNs have been used for the design of a nanocontainer able to release the drug Ataluren. The release profile of the drug can be easily fine-tuned with the careful choice of the capping amine.
Facile Interfacial Engineering of Mesoporous TiO2 for Low-Temperature Processed Perovskite Solar Cells
Authors: Nam Jiyoon , Nam Inje , Song Eun-Jin , Kwon Jung-Dae , Kim Jongbok , Kim Chang Su , Jo Sungjin
Published: August 2019

The mesoporous TiO2 nanoparticle-based scaffold structure is the best electron transport layer (ETL) for perovskite solar cells (PSCs) and is still used in most PSCs with optimal photovoltaic characteristics. However, the high sintering temperature of TiO2 nanoparticles required to remove binders from the TiO2 paste limits PSC application to flexible electronics. In this study, a simple interface modification process involving ethanol rinsing is developed to enhance the photovoltaic characteristics of low-temperature processed PSCs. This easy and fast technique could enable remarkable performance by PSCs by significantly increasing the fill factor and current density, leading to a power conversion efficiency more than four times that of untreated solar cells.
Food Packaging Based on Nanomaterials
Authors: López-Rubio Amparo , Fabra Maria José , Martínez-Sanz Marta
Published: August 2019

The use of nanomaterials for food applications is a rapidly evolving field and, given the specific properties of nanomaterials and their tremendous potential, an increased number of material innovations that contribute to improved food quality and safety are foreseen [...]
Linear-Polyethyleneimine-Templated Synthesis of N-Doped Carbon Nanonet Flakes for High-performance Supercapacitor Electrodes
Authors: Xia Dengchao , Quan Junpeng , Wu Guodong , Liu Xinling , Zhang Zongtao , Ji Haipeng , Chen Deliang , Zhang Liying , Wang Yu , Yi Shasha , Zhou Ying , Gao Yanfeng , Jin Ren-hua
Published: August 2019

Novel N-doped carbon nanonet flakes (NCNFs), consisting of three-dimensional interconnected carbon nanotube and penetrable mesopore channels were synthesized in the assistance of a hybrid catalytic template of silica-coated-linear polyethyleneimine (PEI). Resorcinol-formaldehyde resin and melamine were used as precursors for carbon and nitrogen, respectively, which were spontaneously formed on the silica-coated-PEI template and then annealed at 700 °C in a N2 atmosphere to be transformed into the hierarchical 3D N-doped carbon nanonetworks. The obtained NCNFs possess high surface area (946 m2 g−1), uniform pore size (2–5 nm), and excellent electron and ion conductivity, which were quite beneficial for electrochemical double-layered supercapacitors (EDLSs). The supercapacitor synthesized from NCNFs electrodes exhibited both extremely high capacitance (up to 613 F g−1 at 1 A g−1) and excellent long-term capacitance retention performance (96% capacitive retention after 20,000 cycles), which established the current processing among the most competitive strategies for the synthesis of high performance supercapacitors.
Electrical Conductivity of New Nanoparticle Enhanced Fluids: An Experimental Study
Authors: Chereches Elena Ionela , Minea Alina Adriana
Published: August 2019

In this research, the electrical conductivity of simple and hybrid nanofluids containing Al2O3, TiO2 and SiO2 nanoparticles and water as the base fluid was experimentally studied at ambient temperature and with temperature variation in the range of 20–60 °C. A comparison of the experimental data with existing theoretical models demonstrated that the theoretical models under-predict the experimental data. Consequently, several correlations were developed for nanofluid electrical conductivity estimation in relation to temperature and volume concentration. The electrical conductivity of both simple and hybrid nanofluids increased linearly with both volume concentration and temperature upsurge. More precisely, by adding nanoparticles to water, the electrical conductivity increased from 11 times up to 58 times for both simple and hybrid nanofluids, with the maximum values being attained for the 3% volume concentration. Plus, a three-dimensional regression analysis was performed to correlate the electrical conductivity with temperature and volume fraction of the titania and silica nanofluids. The thermo-electrical conductivity ratio has been calculated based on electrical conductivity experimental results and previously determined thermal conductivity. Very low figures were noticed. Concluding, one may affirm that further experimental work is needed to completely elucidate the behavior of nanofluids in terms of electrical conductivity.