bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of the CCL5/CCR5 Axis against the Progression of Gastric Cancer
Authors: Aldinucci Donatella , Casagrande Naike
Published: May 2018

Despite the progress made in molecular and clinical research, patients with advanced-stage gastric cancer (GC) have a bad prognosis and very low survival rates. Furthermore, it is challenging to find the complex molecular mechanisms that are involved in the development of GC, its progression, and its resistance to therapy. The interactions of chemokines, also known as chemotactic cytokines, with their receptors regulate immune and inflammatory responses. However, updated research demonstrates that cancer cells subvert the normal chemokine role, transforming them into fundamental constituents of the tumor microenvironment (TME) with tumor-promoting effects. C-C chemokine ligand 5 (CCL5) is a chemotactic cytokine, and its expression and secretion are regulated in T cells. C-C chemokine receptor type 5 (CCR5) is expressed in T cells, macrophages, other leukocytes, and certain types of cancer cells. The interaction between CCL5 and CCR5 plays an active role in recruiting leukocytes into target sites. This review summarizes recent information on the role of the CCL5 chemokine and its receptor CCR5 in GC cell proliferation, metastasis formation, and in the building of an immunosuppressive TME. Moreover, it highlights the development of new therapeutic strategies to inhibit the CCL5/CCR5 axis in different ways and their possible clinical relevance in the treatment of GC.
Synthesis, Molecular Structure, Anticancer Activity, and QSAR Study of N-(aryl/heteroaryl)-4-(1H-pyrrol-1-yl)Benzenesulfonamide Derivatives
Authors: Żołnowska Beata , Sławiński Jarosław , Brzozowski Zdzisław , Kawiak Anna , Belka Mariusz , Zielińska Joanna , Bączek Tomasz , Chojnacki Jarosław
Published: May 2018

A series of N-(aryl/heteroaryl)-4-(1H-pyrrol-1-yl)benzenesulfonamides were synthesized from 4-amino-N-(aryl/heteroaryl)benzenesulfonamides and 2,5-dimethoxytetrahydrofuran. All the synthesized compounds were evaluated for their anticancer activity on HeLa, HCT-116, and MCF-7 human tumor cell lines. Compound 28, bearing 8-quinolinyl moiety, exhibited the most potent anticancer activity against the HCT-116, MCF-7, and HeLa cell lines, with IC50 values of 3, 5, and 7 µM, respectively. The apoptotic potential of the most active compound (28) was analyzed through various assays: phosphatidylserine translocation, cell cycle distribution, and caspase activation. Compound 28 promoted cell cycle arrest in G2/M phase in cancer cells, induced caspase activity, and increased the population of apoptotic cells. Relationships between structure and biological activity were determined by the QSAR (quantitative structure activity relationships) method. Analysis of quantitative structure activity relationships allowed us to generate OPLS (Orthogonal Projections to Latent Structure) models with verified predictive ability that point out key molecular descriptors influencing benzenosulfonamide’s activity.
Lateral Membrane Heterogeneity Regulates Viral-Induced Membrane Fusion during HIV Entry
Authors: Molotkovsky Rodion J. , Alexandrova Veronika V. , Galimzyanov Timur R. , Jiménez-Munguía Irene , Pavlov Konstantin V. , Batishchev Oleg V. , Akimov Sergey A.
Published: May 2018

Sphingomyelin- and cholesterol- enriched membrane domains, commonly referred to as “rafts” play a crucial role in a large number of intra- and intercellular processes. Recent experiments suggest that not only the volumetric inhomogeneity of lipid distribution in rafts, but also the arrangement of the 1D boundary between the raft and the surrounding membrane is important for the membrane-associated processes. The reason is that the boundary preferentially recruits different peptides, such as HIV (human immunodeficiency virus) fusion peptide. In the present work, we report a theoretical investigation of mechanisms of influence of the raft boundary arrangement upon virus-induced membrane fusion. We theoretically predict that the raft boundary can act as an attractor for viral fusion peptides, which preferentially distribute into the vicinity of the boundary, playing the role of ‘line active components’ of the membrane (‘linactants’). We have calculated the height of the fusion energy barrier and demonstrated that, in the case of fusion between HIV membrane and the target cell, presence of the raft boundary in the vicinity of the fusion site facilitates fusion. The results we obtained can be further generalized to be applicable to other enveloped viruses.
Alpha-Mangostin Improves Insulin Secretion and Protects INS-1 Cells from Streptozotocin-Induced Damage
Authors: Lee Dahae , Kim Young-Mi , Jung Kiwon , Chin Young-Won , Kang Ki Sung
Published: May 2018

Alpha (α)-mangostin, a yellow crystalline powder with a xanthone core structure, is isolated from mangosteen (Garcinia mangostana), which is a tropical fruit of great nutritional value. The aim of the present study was to investigate the anti-diabetic effects of α-mangostin and to elucidate the molecular mechanisms underlying its effect on pancreatic beta (β)-cell dysfunction. To assess the effects of α-mangostin on insulin production, rat pancreatic INS-1 cells were treated with non-toxic doses of α-mangostin (1–10 μM) and its impact on insulin signaling was examined by Western blotting. In addition, the protective effect of α-mangostin against pancreatic β-cell apoptosis was verified by using the β-cell toxin streptozotocin (STZ). Our results showed that α-mangostin stimulated insulin secretion in INS-1 cells by activating insulin receptor (IR) and pancreatic and duodenal homeobox 1 (Pdx1) followed by phosphorylation of phospho-phosphatidylinositol-3 kinase (PI3K), Akt, and extracellular signal regulated kinase (ERK) signaling cascades, whereas it inhibited the phosphorylation of insulin receptor substrate (IRS-1) (Ser1101). Moreover, α-mangostin was found to restore the STZ-induced decrease in INS-1 cell viability in a dose-dependent manner. In addition, treatment of INS-1 cells with 50 μM STZ resulted in an increase in intracellular reactive oxygen species (ROS) levels, which was represented by the fluorescence intensity of 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA). This oxidative stress was decreased by co-treatment with 5 μM α-mangostin. Similarly, marked increases in the phosphorylation of P38, c-Jun N-terminal kinase (JNK), and cleavage of caspase-3 by STZ were decreased significantly by co-treatment with 5 μM α-mangostin. These results suggest that α-mangostin is capable of improving insulin secretion in pancreatic β-cells and protecting cells from apoptotic damage.
Effects of Sparassis crispa in Medical Therapeutics: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Authors: Thi Nhu Ngoc Le , Oh You-Kwan , Lee Young-Jong , Lee Young-Chul
Published: May 2018

In this study, we investigated the therapeutic potential and medical applications of Sparassis crispa (S. crispa) by conducting a systematic review of the existing literature and performing a meta-analysis. The original efficacy treatment of the mushroom extract is considered primarily and searched in electronic databases. A total of 623 articles were assessed, 33 randomized controlled experiments were included after the manual screening, and some papers, review articles, or editorials that did not contain data were excluded. A comparative standard means difference (SMD) and a funnel plot between control and S. crispa groups were used as parameters to demonstrate the beneficial effects of S. crispa for diabetes and cancer treatment, as well as anti-inflammatory, anti-fungal and antioxidant activities. The meta-analysis was carried out using Review Manager 5.1 software. Although for therapeutic diabetes there was heterogeneity in the subgroup analysis (I2 = 91.9%), the overall results showed statistically significant SMDs in major symptoms that decreased serum insulin levels (SMD = 1.92, 95% CI (1.10, 2.75), I2 = 0%), wound rates (SMD = 3.55 (2.56, 4.54), I2 = 40%) and contributions to an increase in nutrient intake content (SMD = 0.32 (−0.15, 0.78), I2 = 0%). Simultaneously, the study confirmed the utility of S. crispa treatment in terms of not only anti-cancer activity (reduction of tumor activity and survival of cancer cells I2 = 42 and 34%, respectively) but also anti-inflammatory, anti-fungal and antioxidant activities (I2 = 50, 44, and 10%, respectively). Our findings suggest that S. crispa extracts are useful for prevention and treatment of human diseases and might be the best candidates for future medicines.
A Rapid Screen for Host-Encoded miRNAs with Inhibitory Effects against Ebola Virus Using a Transcription- and Replication-Competent Virus-Like Particle System
Authors: Wang Zhongyi , Li Jiaming , Fu Yingying , Zhao Zongzheng , Zhang Chunmao , Li Nan , Li Jingjing , Cheng Hongliang , Jin Xiaojun , Lu Bing , Guo Zhendong , Qian Jun , Liu Linna
Published: May 2018

MicroRNAs (miRNAs) may become efficient antiviral agents against the Ebola virus (EBOV) targeting viral genomic RNAs or transcripts. We previously conducted a genome-wide search for differentially expressed miRNAs during viral replication and transcription. In this study, we established a rapid screen for miRNAs with inhibitory effects against EBOV using a tetracistronic transcription- and replication-competent virus-like particle (trVLP) system. This system uses a minigenome comprising an EBOV leader region, luciferase reporter, VP40, GP, VP24, EBOV trailer region, and three noncoding regions from the EBOV genome and can be used to model the life cycle of EBOV under biosafety level (BSL) 2 conditions. Informatic analysis was performed to select up-regulated miRNAs targeting the coding regions of the minigenome with the highest binding energy to perform inhibitory effect screening. Among these miRNAs, miR-150-3p had the most significant inhibitory effect. Reverse transcription polymerase chain reaction (RT-PCR), Western blot, and double fluorescence reporter experiments demonstrated that miR-150-3p inhibited the reproduction of trVLPs via the regulation of GP and VP40 expression by directly targeting the coding regions of GP and VP40. This novel, rapid, and convenient screening method will efficiently facilitate the exploration of miRNAs against EBOV under BSL-2 conditions.
Tau Fibril Formation in Cultured Cells Compatible with a Mouse Model of Tauopathy
Authors: Matsumoto Gen , Matsumoto Kazuki , Kimura Taeko , Suhara Tetsuya , Higuchi Makoto , Sahara Naruhiko , Mori Nozomu
Published: May 2018

Neurofibrillary tangles composed of hyperphosphorylated tau protein are primarily neuropathological features of a number of neurodegenerative diseases collectively termed tauopathy. To understand the mechanisms underlying the cause of tauopathy, precise cellular and animal models are required. Recent data suggest that the transient introduction of exogenous tau can accelerate the development of tauopathy in the brains of non-transgenic and transgenic mice expressing wild-type human tau. However, the transmission mechanism leading to tauopathy is not fully understood. In this study, we developed cultured-cell models of tauopathy representing a human tauopathy. Neuro2a (N2a) cells containing propagative tau filaments were generated by introducing purified tau fibrils. These cell lines expressed full-length (2N4R) human tau and the green fluorescent protein (GFP)-fused repeat domain of tau with P301L mutation. Immunocytochemistry and super-resolution microscopic imaging revealed that tau inclusions exhibited filamentous morphology and were composed of both full-length and repeat domain fragment tau. Live-cell imaging analysis revealed that filamentous tau inclusions are transmitted to daughter cells, resulting in yeast-prion-like propagation. By a standard method of tau preparation, both full-length tau and repeat domain fragments were recovered in sarkosyl insoluble fraction. Hyperphosphorylation of full-length tau was confirmed by the immunoreactivity of phospho-Tau antibodies and mobility shifts by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). These properties were similar to the biochemical features of P301L mutated human tau in a mouse model of tauopathy. In addition, filamentous tau aggregates in cells barely co-localized with ubiquitins, suggesting that most tau aggregates were excluded from protein degradation systems, and thus propagated to daughter cells. The present cellular model of tauopathy will provide an advantage for dissecting the mechanisms of tau aggregation and degradation and be a powerful tool for drug screening to prevent tauopathy.
Downregulation of the S1P Transporter Spinster Homology Protein 2 (Spns2) Exerts an Anti-Fibrotic and Anti-Inflammatory Effect in Human Renal Proximal Tubular Epithelial Cells
Authors: Blanchard Olivier , Stepanovska Bisera , Starck Manuel , Erhardt Martin , Römer Isolde , Meyer zu Heringdorf Dagmar , Pfeilschifter Josef , Zangemeister-Wittke Uwe , Huwiler Andrea
Published: May 2018

Sphingosine kinase (SK) catalyses the formation of sphingosine 1-phosphate (S1P), which acts as a key regulator of inflammatory and fibrotic reactions, mainly via S1P receptor activation. Here, we show that in the human renal proximal tubular epithelial cell line HK2, the profibrotic mediator transforming growth factor β (TGFβ) induces SK-1 mRNA and protein expression, and in parallel, it also upregulates the expression of the fibrotic markers connective tissue growth factor (CTGF) and fibronectin. Stable downregulation of SK-1 by RNAi resulted in the increased expression of CTGF, suggesting a suppressive effect of SK-1-derived intracellular S1P in the fibrotic process, which is lost when SK-1 is downregulated. In a further approach, the S1P transporter Spns2, which is known to export S1P and thereby reduces intracellular S1P levels, was stably downregulated in HK2 cells by RNAi. This treatment decreased TGFβ-induced CTGF and fibronectin expression, and it abolished the strong induction of the monocyte chemotactic protein 1 (MCP-1) by the pro-inflammatory cytokines tumor necrosis factor (TNF)α and interleukin (IL)-1β. Moreover, it enhanced the expression of aquaporin 1, which is an important water channel that is expressed in the proximal tubules, and reverted aquaporin 1 downregulation induced by IL-1β/TNFα. On the other hand, overexpression of a Spns2-GFP construct increased S1P secretion and it resulted in enhanced TGFβ-induced CTGF expression. In summary, our data demonstrate that in human renal proximal tubular epithelial cells, SK-1 downregulation accelerates an inflammatory and fibrotic reaction, whereas Spns2 downregulation has an opposite effect. We conclude that Spns2 represents a promising new target for the treatment of tubulointerstitial inflammation and fibrosis.
Approaches in Polymeric Nanoparticles for Vaginal Drug Delivery: A Review of the State of the Art
Authors: Leyva-Gómez Gerardo , Piñón-Segundo Elizabeth , Mendoza-Muñoz Néstor , Zambrano-Zaragoza María , Mendoza-Elvira Susana , Quintanar-Guerrero David
Published: May 2018

The vagina is a region of administration with a high contact surface to obtain local or systemic effects. This anatomical area represents special interest for government health systems for different sexually transmitted infections. However, the chemical changes of the vagina, as well as its abundant mucus in continuous exchange, act as a barrier and a challenge for the development of new drugs. For these purposes, the development of new pharmaceutical forms based on nanoparticles has been shown to offer various advantages, such as bioadhesion, easy penetration of the mucosa, and controlled release, in addition to decreasing the adverse effects of conventional pharmaceutical forms. In order to obtain nanoparticles for vaginal administration, the use of polymers of natural and synthetic origin including biodegradable and non-biodegradable systems have gained great interest both in nanospheres and in nanocapsules. The main aim of this review is to provide an overview of the development of nanotechnology for vaginal drug release, analyzing the different compositions of polymeric nanoparticles, and emphasizing new trends in each of the sections presented. At the end of this review, a section analyzes the properties of the vehicles employed for the administration of nanoparticles and discusses how to take advantage of the properties that they offer. This review aims to be a reference guide for new formulators interested in the vaginal route.
Polymeric Micelles Based on Modified Glycol Chitosan for Paclitaxel Delivery: Preparation, Characterization and Evaluation
Authors: Liang Na , Sun Shaoping , Gong Xianfeng , Li Qiang , Yan Pengfei , Cui Fude
Published: May 2018

Amphiphilic polymer of α-tocopherol succinate modified glycol chitosan (TS-GC) was successfully constructed by conjugating α-tocopherol succinate to the skeleton of glycol chitosan and characterized by Fourier-transform infrared (FT-IR) and proton nuclear magnetic resonance (1H-NMR). In aqueous milieu, the conjugates self-assembled to micelles with the critical aggregation concentration of 7.2 × 10−3 mg/mL. Transmission electron microscope (TEM) observation and dynamic light scattering (DLS) measurements were carried out to determine the physicochemical properties of the micelles. The results revealed that paclitaxel (PTX)-loaded TS-GC micelles were spherical in shape. Moreover, the PTX-loaded micelles showed increased particle sizes (35 nm vs. 142 nm) and a little reduced zeta potential (+19 mV vs. +16 mV) compared with blank micelles. The X-ray diffraction (XRD) spectra demonstrated that PTX existed inside the micelles in amorphous or molecular state. In vitro and in vivo tests showed that the PTX-loaded TS-GC micelles had advantages over the Cremophor EL-based formulation in terms of low toxicity level and increased dose, which suggested the potential of the polymer as carriers for PTX to improve their delivery properties.
Isoviolanthin Extracted from Dendrobium officinale Reverses TGF-β1-Mediated Epithelial–Mesenchymal Transition in Hepatocellular Carcinoma Cells via Deactivating the TGF-β/Smad and PI3K/Akt/mTOR Signaling Pathways
Authors: Xing Shangping , Yu Wenxia , Zhang Xiaofeng , Luo Yingyi , Lei Zhouxi , Huang Dandan , Lin Ji , Huang Yuechun , Huang Shaowei , Nong Feifei , Zhou Chunhua , Wei Gang
Published: May 2018

Dendrobium officinale is a precious medicinal herb and health food, and its pharmacological actions have been studied and proved. However, the mechanisms by which its active flavonoid glycosides affect epithelial–mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) cells, such as HepG2 and Bel-7402 cells, have not been previously investigated. Therefore, we investigated whether isoviolanthin extracted from the leaves of Dendrobium officinale inhibits transforming growth factor (TGF)-β1-induced EMT in HCC cells. In this study, the physicochemical properties and structure of isoviolanthin were identified by HPLC, UV, ESIMS, and NMR and were compared with literature data. HCC cells were pretreated with 10 ng/mL TGF-β1 to induce EMT and then treated with isoviolanthin. Herein, we found that isoviolanthin exhibited no cytotoxic effects on normal liver LO2 cells but notably reduced the migratory and invasive capacities of TGF-β1-treated HCC cells. Additionally, isoviolanthin treatment decreased matrix metalloproteinase (MMP)-2 and -9 levels, and remarkably altered the expression of EMT markers via regulating the TGF-β/Smad and PI3K/Akt/mTOR signaling pathways; Western blot analysis confirmed that the effects of the inhibitors SB431542 and LY294002 were consistent with those of isoviolanthin. These findings demonstrate the potential of isoviolanthin as a therapeutic agent for the treatment of advanced-stage metastatic HCC.
Supplementation with IL-6 and Muscle Cell Culture Conditioned Media Enhances Myogenic Differentiation of Adipose Tissue-Derived Stem Cells through STAT3 Activation
Authors: Seo Eunhui , Kang Hwansu , Lim Oh-Kyung , Jun Hee-Sook
Published: May 2018

Mature skeletal muscle cells cannot be expanded in culture systems. Therefore, it is difficult to construct an in vitro model for muscle diseases. To establish an efficient protocol for myogenic differentiation of human adipose tissue-derived stem cells (hADSCs), we investigated whether addition of IL-6 and/or myocyte-conditioned media (CM) to conventional differentiation media can shorten the differentiation period. hADSCs were differentiated to myocytes using the conventional protocol or modified with the addition of 25 pg/mL IL-6 and/or C2C12 CM (25% v/v). The expression of MyoD and myogenine mRNA was significantly higher at 5–6 days after differentiation using the modified protocol than with the conventional protocol. mRNA and protein expression of myosin heavy chain, a marker of myotubes, was significantly upregulated at 28 and 42 days of differentiation using the modified protocol, and the level achieved after a 4-week differentiation period was similar to that achieved at 6 weeks using the conventional protocol. The expression of p-STAT3 was significantly increased when the modified protocol was used. Similarly, addition of colivelin, a STAT3 activator, instead of IL-6 and C2C12 CM, promoted the myogenic differentiation of ADSCs. The modified protocol improved differentiation efficiency and reduced the time required for differentiation of myocytes. It might be helpful to save cost and time when preparing myocytes for cell therapies and drug discovery.
Sensitivity Analysis of BLISK Airfoil Wear
Authors: Kellersmann Andreas , Reitz Gerald , Friedrichs Jens
Published: May 2018

The decreasing performance of jet engines during operation is a major concern for airlines and maintenance companies. Among other effects, the erosion of high-pressure compressor (HPC) blades is a critical one and leads to a changed aerodynamic behavior, and therefore to a change in performance. The maintenance of BLISKs (blade-integrated-disks) is especially challenging because the blade arrangement cannot be changed and individual blades cannot be replaced. Thus, coupled deteriorated blades have a complex aerodynamic behavior which can have a stronger influence on compressor performance than a conventional HPC. To ensure effective maintenance for BLISKs, the impact of coupled misshaped blades are the key factor. The present study addresses these effects on the aerodynamic performance of a first-stage BLISK of a high-pressure compressor. Therefore, a design of experiments (DoE) is done to identify the geometric properties which lead to a reduction in performance. It is shown that the effect of coupled variances is dependent on the operating point. Based on the DoE analysis, the thickness-related parameters, the stagger angle, and the max. profile camber as coupled parameters are identified as the most important parameters for all operating points.
Microstructural and Microhardness Evolution from Homogenization and Hot Isostatic Pressing on Selective Laser Melted Inconel 718: Structure, Texture, and Phases
Authors: Seede Raiyan , Mostafa Ahmad , Brailovski Vladimir , Jahazi Mohammad , Medraj Mamoun
Published: May 2018

In this work, the microstructure, texture, phases, and microhardness of 45° printed (with respect to the build direction) homogenized, and hot isostatically pressed (HIP) cylindrical IN718 specimens are investigated. Phase morphology, grain size, microhardness, and crystallographic texture at the bottom of each specimen differ from those of the top due to changes in cooling rate. High cooling rates during the printing process generated a columnar grain structure parallel to the building direction in the as-printed condition with a texture transition from (001) orientation at the bottom of the specimen to (111) orientation towards the specimen top based on EBSD analysis. A mixed columnar and equiaxed grain structure associated with about a 15% reduction in texture is achieved after homogenization treatment. HIP treatment caused significant grain coarsening, and engendered equiaxed grains with an average diameter of 154.8 µm. These treatments promoted the growth of δ-phase (Ni3Nb) and MC-type brittle (Ti, Nb)C carbides at grain boundaries. Laves phase (Fe2Nb) was also observed in the as-printed and homogenized specimens. Ostwald ripening of (Ti, Nb)C carbides caused excessive grain growth at the bottom of the HIPed IN718 specimens, while smaller grains were observed at their top. Microhardness in the as-fabricated specimens was 236.9 HV and increased in the homogenized specimens by 19.3% to 282.6 HV due to more even distribution of secondary precipitates, and the nucleation of smaller grains. A 36.1% reduction in microhardness to 180.5 HV was found in the HIPed condition due to   γ ″ phase dissolution and differences in grain morphology.
Credit Rating and Pricing: Poles Apart
Authors: Blöchlinger Andreas
Published: May 2018

Corporate credit ratings remove the information asymmetry between lenders and borrowers to find an equilibrium price. Structured finance ratings, however, are informationally insufficient because the systematic risk of equally rated assets can vary substantially. As I demonstrate in a Monte Carlo analysis, highly-rated structured finance bonds can exhibit far higher non-linear systematic risks than lowly-rated corporate bonds. I value credit instruments under a four-moment CAPM, between and within some markets there is no one-to-one relation between expected loss (rating) and credit spread (pricing). The linear CAPM beta is insufficient, buyers and sellers need also the same information on non-linear risk to have an equilibrium.
Tensile Property of ANSI 304 Stainless Steel Weldments Subjected to Cavitation Erosion Based on Treatment of Laser Shock Processing
Authors: Zhang Lei , Liu Yue-Hua , Luo Kai-Yu , Zhang Yong-Kang , Zhao Yong , Huang Jian-Yun , Wu Xu-Dong , Zhou Chuang
Published: May 2018

Tensile property was one important index of mechanical properties of ANSI 304 stainless steel laser weldments subjected to cavitation erosion (CE). Laser shock processing (LSP) was utilized to strengthen the CE resistance, and the tensile property and fracture morphology were analyzed through three replicated experiment times. Results showed tensile process of treated weldments was composed of elastic deformation, plastic deformation, and fracture. The elastic limit, elastic modulus, elongation, area reduction, and ultimate tensile strength of tensile sample after CE were higher in view of LSP. In the fracture surface, the fiber zone, radiation zone and shear lip zone were generated, and those were more obvious through LSP. The number and size of pores in the fracture surface were smaller, and the fracture surface was smoother and more uniform. The dimples were elongated along the unified direction due to effects of LSP, and the elongated direction was in agreement with the crack propagation direction. Their distribution and shape were uniform with deeper depth. It could be reflected that the tensile property was improved by LSP and the CE resistance was also enhanced.
The Effect of Negative Pressure Wound Therapy with and without Instillation on Mature Biofilms In Vitro
Authors: Tahir Shamaila , Malone Matthew , Hu Honghua , Deva Anand , Vickery Karen
Published: May 2018

Background: To investigate the effect of negative pressure wound therapy (NPWT) with and without instillation (NPWTi) on in vitro mature biofilm. Methods: Mature biofilms of Pseudomonas aeruginosa and Staphylococcus aureus were grown under shear (130 rpm) on polycarbonate coupons in a CDC biofilm reactor for 3 days. Coupons containing biofilms were placed in a sterile petri dish and sealed using NPWT or NPWTi. Coupons were exposed to treatment for 24 h with NPWT alone or with instillation of: Povidone iodine solution (PVP-I) (10% w/v equivalent to 1% w/v available iodine, BETADINE®, Mundipharma, Singapore), surfactant based antimicrobial solution with polyhexamethylene biguanide (SBPHMB) (Prontosan®, B Braun Medical, Melsungen, Germany), Gentamicin 1 µg/mL (GM) (G1264 Sigma-Aldrich Pty Ltd., Castle Hill, Australia) Rifampicin 24 µg/mL (RF) (R3501 Sigma-Aldrich Pty Ltd., Castle Hill, Australia) and NaCl 0.9% (Baxter, Deerfield, IL, USA). Bacterial cell viability and biofilm architecture pre-and post-treatment were assessed using colony forming units (cfu), Live/Dead viability staining, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Results: Significant reductions were obtained in S. aureus biofilm thickness (65%) and mass (47%) when treated with NPWTi as compared to NPWT only. NPWTi with instillation of SBPHMB, PVP-I and RF achieved between 2 and 8 log10 reductions against S. aureus biofilm (p < 0.05–0.001). Conversely, PVP-I and SBMO achieved a 3.5 log10 reduction against P. aeruginosa (p < 0.05). Conclusions: NPWT alters biofilm architecture by reducing biofilm thickness and mass, but this does not affect bacterial cell viability. NPWT with instillation of certain antimicrobials solutions may provide a further synergistic effect in reducing the number of viable biofilm microorganisms. Our in vitro model may be used for screening the effectiveness of antimicrobials used under instillation prior to animal or human studies.
Evolution of Grain Interfaces in Annealed Duplex Stainless Steel after Parallel Cross Rolling and Direct Rolling
Authors: Wang Ming , Li Haoqing , Tian Yujing , Guo Hong , Fang Xiaoying , Guo Yuebin
Published: May 2018

Changes in various grain interfaces, including the grain boundary and phase boundary, are a strong indication of microstructural changes, particularly ultra-fined grains achieved by large strain deformation and subsequent annealing. After direct rolling and cross rolling with the same strain of ε = 2, the distributions of the interfaces in annealed UNS S32304 duplex stainless steel were investigated using electron backscatter diffraction (EBSD) in this study. The ferrite experienced continued recovery, and a high density of low-angle grain boundaries (LAGBs) was produced. The percentage and number of twin boundaries (TBs) and LAGBs varied within the austenite. TBs were frequently found within austenite, showing a deviation from the Kurdjumov-Sachs (K-S) orientation relationship (OR) with ferrite matrix. However, LAGBs usually occur in austenite, with the K-S OR in the ferrite matrix. LAGBs were prevalent in the precipitated austenite grains, and therefore a strong texture was introduced in the cross-rolled and annealed samples, in which the precipitated austenite readily maintained the K-S OR in the ferrite matrix. By contrast, more TBs and a less robust texture were found in the precipitated austenite in direct-rolled and annealed samples, deviating from the K-S OR.
Fe-Based Nano-Materials in Catalysis
Authors: Theofanidis Stavros Alexandros , Galvita Vladimir V. , Konstantopoulos Christos , Poelman Hilde , Marin Guy B.
Published: May 2018

The role of iron in view of its further utilization in chemical processes is presented, based on current knowledge of its properties. The addition of iron to a catalyst provides redox functionality, enhancing its resistance to carbon deposition. FeOx species can be formed in the presence of an oxidizing agent, such as CO2, H2O or O2, during reaction, which can further react via a redox mechanism with the carbon deposits. This can be exploited in the synthesis of active and stable catalysts for several processes, such as syngas and chemicals production, catalytic oxidation in exhaust converters, etc. Iron is considered an important promoter or co-catalyst, due to its high availability and low toxicity that can enhance the overall catalytic performance. However, its operation is more subtle and diverse than first sight reveals. Hence, iron and its oxides start to become a hot topic for more scientists and their findings are most promising. The scope of this article is to provide a review on iron/iron-oxide containing catalytic systems, including experimental and theoretical evidence, highlighting their properties mainly in view of syngas production, chemical looping, methane decomposition for carbon nanotubes production and propane dehydrogenation, over the last decade. The main focus goes to Fe-containing nano-alloys and specifically to the Fe–Ni nano-alloy, which is a very versatile material.
Microstructures Evolution and Micromechanics Features of Ni-Cr-Si Coatings Deposited on Copper by Laser Cladding
Authors: Zhang Peilei , Li Mingchuan , Yu Zhishui
Published: May 2018

Three Ni-Cr-Si coatings were synthesized on the surface of copper by laser cladding. The microstructures of the coatings were characterized by optical microscopy (OM), X-ray diffraction (XRD), and scanning electron microscopy (SEM) with an energy dispersive spectrometer (EDS). According to the analysis results of phase compositions, Gibbs free energy change and microstructures, the phases of three coatings appeared were Cr3Si+γ-Ni+Cuss (Coating 1, Ni-26Cr-29Si), Cr6Ni16Si7+Ni2Si+Cuss (Coating 2, Ni-10Cr-30Si) and Cr3Ni5Si2+Cr2Ni3+Cuss (Coating 3, Ni-29Cr-16Si). The crystal growth in the solidification process was analyzed with a modified model, which is a combination of Kurz-Giovanola-Trivedi (KGT) and Lipton-Kurz-Trivedi (LKT) models. The dendrite tip undercooling in Coating 2 was higher than those of Coating 1 and Coating 3. Well-developed dendrites were found in Coating 2. A modification of Hunt’s model was adopted to describe the morphological differences in the three coatings. The results show that Coating 1 was in the equiaxed dendrite region, while Coatings 2 and 3 were in the columnar dendrite region. The average friction coefficients of the three coatings were 0.45, 0.5 and 0.4, respectively. Obvious plastic deformation could be found in the subsurface zone of Coatings 2 and 3.
Cu(II)–N6-Alkyladenine Complexes: Synthesis, X-ray Characterization and Magnetic Properties
Authors: Martínez María Soledad , Bauzá Antonio , Caubet Amparo , García-Raso Ángel , Terrón Ángel , Fiol Juan J. , Molins Elies , Barceló-Oliver Miquel , Frontera Antonio
Published: May 2018

Three new dinuclear copper(II) complexes [Cu2(μ–HLn)2(μ-Cl)2Cl2]Cl2 (1–3) have been synthesized and structurally characterized by single-crystal X-ray diffraction, where HLx, (HL1 = N6-propyladeninium, HL2 = N6-butyladeninium and HL3 = N6-isobutyladeninium) are N6-alkyl bidentate NN donor adenine bases. Complexes 1–3 exhibit a coplanar arrangement of both N6-alkyladeninium moieties with UD conformation, with the terms U(up) or D(down) referring to the coordination of each pyrimidinic N3 atoms to the upper or lower metal center. In the three complexes, both copper atoms are five-coordinated (N2Cl3 donor set), resembling a compressed trigonal bipyramid. Each adenine moiety is protonated in N1 and the positive charge balanced by chloride counterions. Magnetic measurements of complexes 1 and 3 in the 2–300 K temperature range indicate antiferromagnetic coupling with J = −156.1(7) and J = −151(2) cm−1, respectively. Density functional theory calculations have also been performed in order to estimate the exchange coupling constants in these complexes. The theoretically calculated J values are in good agreement with the experimental values.
Attenuation of Metabolic Syndrome by EPA/DHA Ethyl Esters in Testosterone-Deficient Obese Rats
Authors: Bhandarkar Nikhil S. , Kumar Senthil Arun , Martin Jarad , Brown Lindsay , Panchal Sunil K.
Published: May 2018

Inducing testosterone deficiency, as the standard treatment of prostate cancer, may cause metabolic disorders including insulin resistance, dyslipidemia, central obesity, cardiovascular diseases, and type 2 diabetes. This study measured responses to testosterone deficiency in high-carbohydrate, high-fat (H) diet-fed rats. We then tested whether eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) ethyl esters (Omacor) reversed these metabolic changes. Male Wistar rats (8–9 weeks old) were divided into eight groups with four groups fed corn starch and four groups fed H diet. For each diet, one group received diet only; one group was orchidectomized; one group was given leuprolide (gonadotrophin-releasing hormone agonist, 2 mg/kg every 4th week); and the last group was treated with leuprolide and their diet was supplemented with 3% Omacor for the last eight weeks. The protocol was for 16 weeks. Leuprolide worsened metabolic syndrome symptoms and cardiovascular function, and orchidectomy produced greater responses. In H fed leuprolide-treated rats, Omacor decreased systolic blood pressure and left ventricular diastolic stiffness, reduced infiltration of inflammatory cells and collagen deposition in the heart, and reduced lipid accumulation and inflammatory cell infiltration without improving liver damage. These results suggest that Omacor has potential to attenuate metabolic complications in prostate cancer patients with induced testosterone deprivation.
Multigene Family of Pore-Forming Toxins from Sea Anemone Heteractis crispa
Authors: Leychenko Elena , Isaeva Marina , Tkacheva Ekaterina , Zelepuga Elena , Kvetkina Aleksandra , Guzev Konstantin , Monastyrnaya Margarita , Kozlovskaya Emma
Published: May 2018

Sea anemones produce pore-forming toxins, actinoporins, which are interesting as tools for cytoplasmic membranes study, as well as being potential therapeutic agents for cancer therapy. This investigation is devoted to structural and functional study of the Heteractis crispa actinoporins diversity. Here, we described a multigene family consisting of 47 representatives expressed in the sea anemone tentacles as prepropeptide-coding transcripts. The phylogenetic analysis revealed that actinoporin clustering is consistent with the division of sea anemones into superfamilies and families. The transcriptomes of both H. crispa and Heteractis magnifica appear to contain a large repertoire of similar genes representing a rapid expansion of the actinoporin family due to gene duplication and sequence divergence. The presence of the most abundant specific group of actinoporins in H. crispa is the major difference between these species. The functional analysis of six recombinant actinoporins revealed that H. crispa actinoporin grouping was consistent with the different hemolytic activity of their representatives. According to molecular modeling data, we assume that the direction of the N-terminal dipole moment tightly reflects the actinoporins’ ability to possess hemolytic activity.
Texture Control of Pure Titanium Sheet by the Surface Effect during Phase Transformation
Authors: Li Kai , Yang Ping , Cui Feng-e , Mao Weimin
Published: May 2018

The texture evolution of cold rolled pure titanium through different annealing parameters was investigated and different processes for various textures controls were proposed for further industrial application. Columnar grains with strong {11–20}//RD (rolling direction) texture was produced through cold rolling and a cooling-controlled annealing at 1100 °C with the Ar atmosphere. The preferred nucleation on the surface and the lowest strain energy of variant pairs during grain growth caused the formation of columnar grains and variant selection. Texture inheritance was discovered both in the cold-rolled and warm rolled-pure titanium sheets following 1000 °C annealing. The stored energy during cold rolling was the main reason causing the texture inheritance. Basal texture could be produced through warm rolling and subsequent annealing. The 30°-rotated around RD from basal texture could be preserved through both recrystallized annealing and transformed annealing.
Structure and Mechanical Properties of a Copper Combustion Chamber throughout Its Life Cycle
Authors: Vaz Diana , Piedade Ana Paula
Published: May 2018

The material of a combustion chamber is subjected to high thermal and mechanical fatigue that can result in premature failure. Nevertheless, there is very little information in the literature concerning its characterization. In this work, the study of some properties of the copper combustion chambers in water heaters throughout their life cycle is described. The microstructure, hardness, morphology, mechanical strength and roughness were evaluated, from the pristine copper sheet to a chamber subjected to 53,000 cycles. Throughout the whole cycle, changes were detected in the organization of the crystalline structure. Both after conformation and after completing the manufacturing process, the material exhibits a preferential orientation according to the direction [110], which is the most favorable to degradation of the material by thermal fatigue. The prevalence of the less dense crystallographic planes of the material in all stages of the life cycle allowed a better diffusion of the oxidant species facilitating the corrosion of the material. The oxidation products did not form a passivated layer and detached from the bulk copper, causing a progressive deterioration of the material.
In-Vivo NMR Spectroscopy: A Powerful and Complimentary Tool for Understanding Environmental Toxicity
Authors: Bastawrous Monica , Jenne Amy , Tabatabaei Anaraki Maryam , Simpson André J.
Published: May 2018

Part review, part perspective, this article examines the applications and potential of in-vivo Nuclear Magnetic Resonance (NMR) for understanding environmental toxicity. In-vivo NMR can be applied in high field NMR spectrometers using either magic angle spinning based approaches, or flow systems. Solution-state NMR in combination with a flow system provides a low stress approach to monitor dissolved metabolites, while magic angle spinning NMR allows the detection of all components (solutions, gels and solids), albeit with additional stress caused by the rapid sample spinning. With in-vivo NMR it is possible to use the same organisms for control and exposure studies (controls are the same organisms prior to exposure inside the NMR). As such individual variability can be reduced while continual data collection over time provides the temporal resolution required to discern complex interconnected response pathways. When multidimensional NMR is combined with isotopic labelling, a wide range of metabolites can be identified in-vivo providing a unique window into the living metabolome that is highly complementary to more traditional metabolomics studies employing extracts, tissues, or biofluids.
Nanostructure-Enabled and Macromolecule-Grafted Surfaces for Biomedical Applications
Authors: Small Madeline , Faglie Addison , Craig Alexandra , Pieper Martha , Fernand Narcisse Vivian , Neuenschwander Pierre , Chou Shih-Feng
Published: May 2018

Advances in nanotechnology and nanomaterials have enabled the development of functional biomaterials with surface properties that reduce the rate of the device rejection in injectable and implantable biomaterials. In addition, the surface of biomaterials can be functionalized with macromolecules for stimuli-responsive purposes to improve the efficacy and effectiveness in drug release applications. Furthermore, macromolecule-grafted surfaces exhibit a hierarchical nanostructure that mimics nanotextured surfaces for the promotion of cellular responses in tissue engineering. Owing to these unique properties, this review focuses on the grafting of macromolecules on the surfaces of various biomaterials (e.g., films, fibers, hydrogels, and etc.) to create nanostructure-enabled and macromolecule-grafted surfaces for biomedical applications, such as thrombosis prevention and wound healing. The macromolecule-modified surfaces can be treated as a functional device that either passively inhibits adverse effects from injectable and implantable devices or actively delivers biological agents that are locally based on proper stimulation. In this review, several methods are discussed to enable the surface of biomaterials to be used for further grafting of macromolecules. In addition, we review surface-modified films (coatings) and fibers with respect to several biomedical applications. Our review provides a scientific update on the current achievements and future trends of nanostructure-enabled and macromolecule-grafted surfaces in biomedical applications.
Energy Harvesting Combat Boot for Satellite Positioning
Authors: Akay Haluk , Xu Ruize , Han Dexter Chew Xuan , Teo T. Hui , Kim Sang-Gook
Published: May 2018

Most portable electronic devices are power-limited by battery capacity, and recharging these batteries often interrupts the user’s experience with the device. The product presented in this paper provides an alternative to powering portables by converting regular human walking motion to electricity. The device harvests electric power using air bulbs, distributed in the sole of a shoe to drive a series of micro-turbines connected to small DC motors. The number and position of air bulbs is optimized to harvest the maximum airflow from each foot-strike. The system is designed to continuously drive the micro-turbines by utilizing both outflow and inflow from the air bulbs. A prototype combat boot was fitted on the right foot of a 75 kg test subject, and produced an average continuous power on the order of 10 s of mW over a 22 Ω load during walking at 3.0 mph. This combat boot provides enough electric power to a passive GPS tracker that periodically relays geographical coordinates to a smartphone via satellite without battery replacement.
Comparing the Recombinant Protein Production Potential of Planktonic and Biofilm Cells
Authors: Soares Alexandra , Gomes Luciana Calheiros , Mergulhão Filipe José
Published: May 2018

Recombinant protein production in bacterial cells is commonly performed using planktonic cultures. However, the natural state for many bacteria is living in communities attached to surfaces forming biofilms. In this work, a flow cell system was used to compare the production of a model recombinant protein (enhanced green fluorescent protein, eGFP) between planktonic and biofilm cells. The fluorometric analysis revealed that when the system was in steady state, the average specific eGFP production from Escherichia coli biofilm cells was 10-fold higher than in planktonic cells. Additionally, epifluorescence microscopy was used to determine the percentage of eGFP-expressing cells in both planktonic and biofilm populations. In steady state, the percentage of planktonic-expressing cells oscillated around 5%, whereas for biofilms eGFP-expressing cells represented on average 21% of the total cell population. Therefore, the combination of fluorometric and microscopy data allowed us to conclude that E. coli biofilm cells can have a higher recombinant protein production capacity when compared to their planktonic counterparts.