bluuebunny/crossref_metadata_2025 huggingface dataset:
Perspectives for Very High-Resolution Climate Simulations with Nested Models: Illustration of Potential in Simulating St. Lawrence River Valley Channelling Winds with the Fifth-Generation Canadian Regional Climate Model
Authors: Cholette Mélissa , Laprise René , Thériault Julie
Published: April 2015

With the refinement of grid meshes in regional climate models permitted by the increase in computing power, the grid telescoping or cascade method, already used in numerical weather prediction, can be applied to achieve very high-resolution climate simulations. The purpose of this study is two-fold: (1) to illustrate the perspectives offered by climate simulations on kilometer-scale grid meshes using the wind characteristics in the St. Lawrence River Valley (SLRV) as the test-bench; and (2) to establish some constraints to be satisfied for the physical realism and the computational affordability of these simulations. The cascade method is illustrated using a suite of five one-way nested, time-slice simulations carried out with the fifth-generation Canadian Regional Climate Model, with grid meshes varying from roughly 81 km, successively to 27, 9, 3 and finally 1 km, over domains centered on the SLRV. The results show the added value afforded by very high-resolution meshes for a realistic simulation of the SLRV winds. Kinetic energy spectra are used to document the spin-up time and the effective resolution of the simulations as a function of their grid meshes. A pragmatic consideration is developed arguing that kilometer-scale simulations could be achieved at a reasonable computational cost with time-slice simulations of high impact climate events. This study lends confidence to the idea that climate simulations and projections at kilometer-scale could soon become operationally feasible, thus offering interesting perspectives for resolving features that are currently out of reach with coarser-mesh models.
A Diagnostic Model for Dementia in Clinical Practice—Case Methodology Assisting Dementia Diagnosis
Authors: Londos Elisabet
Published: April 2015

Dementia diagnosis is important for many different reasons. Firstly, to separate dementia, or major neurocognitive disorder, from MCI (mild cognitive impairment), mild neurocognitive disorder. Secondly, to define the specific underlying brain disorder to aid treatment, prognosis and decisions regarding care needs and assistance. The diagnostic method of dementias is a puzzle of different data pieces to be fitted together in the best possible way to reach a clinical diagnosis. Using a modified case methodology concept, risk factors affecting cognitive reserve and symptoms constituting the basis of the brain damage hypothesis, can be visualized, balanced and reflected against test results as well as structural and biochemical markers. The model’s origin is the case method initially described in Harvard business school, here modified to serve dementia diagnostics.
Statistical Correlations of the N-particle Moshinsky Model
Authors: Peng Hsuan , Ho Yew
Published: April 2015

We study the correlation of the ground state of an N-particle Moshinsky model by computing the Shannon entropy in both position and momentum spaces. We have derived the Shannon entropy and mutual information with analytical forms of such an N-particle Moshinsky model, and this helps us test the entropic uncertainty principle. The Shannon entropy in position space decreases as interaction strength increases. However, Shannon entropy in momentum space has the opposite trend. Shannon entropy of the whole system satisfies the equality of entropic uncertainty principle. Our results also indicate that, independent of the sizes of the two subsystems, the mutual information increases monotonically as the interaction strength increases.
Kinetic Theory Modeling and Efficient Numerical Simulation of Gene Regulatory Networks Based on Qualitative Descriptions
Authors: Chinesta Francisco , Magnin Morgan , Roux Olivier , Ammar Amine , Cueto Elias
Published: April 2015

In this work, we begin by considering the qualitative modeling of biological regulatory systems using process hitting, from which we define its probabilistic counterpart by considering the chemical master equation within a kinetic theory framework. The last equation is efficiently solved by considering a separated representation within the proper generalized decomposition framework that allows circumventing the so-called curse of dimensionality. Finally, model parameters can be added as extra-coordinates in order to obtain a parametric solution of the model.
Fluvial Transport Model from Spatial Distribution Analysis of Libyan Desert Glass Mass on the Great Sand Sea (Southwest Egypt): Clues to Primary Glass Distribution
Authors: Jimenez-Martinez Nancy , Ramirez Marius , Diaz-Hernandez Raquel , Rodriguez-Gomez Gustavo
Published: April 2015

Libyan Desert Glass (LDG) is a natural silica-rich melted rock found as pieces scattered over the sand and bedrock of the Western Desert of Egypt, northeast of the Gilf Kebir. In this work, a population mixture analysis serves to relate the present spatial distribution of LDG mass density with the Late Oligocene–Early Miocene fluvial dynamics in the Western Desert of Egypt. This was verified from a spatial distribution model that was predicted from the log-normal kriging method using the LDG–mass-dependent transformed variable, Y(x). Both low- and high-density normal populations (–9.2 < Y(x) < –3.5 and –3.8 < Y(x) < 2.1, respectively) were identified. The low-density population was the result of an ordinary fluvial LDG transport/deposition sequence that was active from the time of the melting process, and which lasted until the end of activity of the Gilf River. The surface distribution of the high-density population allowed us to restrict the source area of the melting process. We demonstrate the importance of this geostatistical study in unveiling the probable location of the point where the melting of surficial material occurred and the role of the Gilf River in the configuration of the observed strewn field.
Integrating Environmental and Human Health Databases in the Great Lakes Basin: Themes, Challenges and Future Directions
Authors: Bassil Kate , Sanborn Margaret , Lopez Russ , Orris Peter
Published: April 2015

Many government, academic and research institutions collect environmental data that are relevant to understanding the relationship between environmental exposures and human health. Integrating these data with health outcome data presents new challenges that are important to consider to improve our effective use of environmental health information. Our objective was to identify the common themes related to the integration of environmental and health data, and suggest ways to address the challenges and make progress toward more effective use of data already collected, to further our understanding of environmental health associations in the Great Lakes region. Environmental and human health databases were identified and reviewed using literature searches and a series of one-on-one and group expert consultations. Databases identified were predominantly environmental stressors databases, with fewer found for health outcomes and human exposure. Nine themes or factors that impact integration were identified: data availability, accessibility, harmonization, stakeholder collaboration, policy and strategic alignment, resource adequacy, environmental health indicators, and data exchange networks. The use and cost effectiveness of data currently collected could be improved by strategic changes to data collection and access systems to provide better opportunities to identify and study environmental exposures that may impact human health.
Study of Linkage between Glutathione Pathway and the Antibiotic Resistance of Escherichia coli from Patients’ Swabs
Authors: Kominkova Marketa , Michalek Petr , Cihalova Kristyna , Guran Roman , Cernei Natalia , Nejdl Lukas , Smerkova Kristyna , Dostalova Simona , Chudobova Dagmar , Heger Zbynek , Vesely Radek , Gumulec Jaromir , Kynicky Jindrich , Xhaxhiu Kledi , Zitka Ondrej , Adam Vojtech , Kizek Rene
Published: April 2015

In this work, we focused on the differences between bacterial cultures of E. coli obtained from swabs of infectious wounds of patients compared to laboratory E. coli. In addition, blocking of the protein responsible for the synthesis of glutathione (γ-glutamylcysteine synthase—GCL) using 10 mM buthionine sulfoximine was investigated. Each E. coli showed significant differences in resistance to antibiotics. According to the determined resistance, E. coli were divided into experimental groups based on a statistical evaluation of their properties as more resistant and more sensitive. These groups were also used for finding the differences in a dependence of the glutathione pathway on resistance to antibiotics. More sensitive E. coli showed the same kinetics of glutathione synthesis while blocking GCL (Km 0.1 µM), as compared to non-blocking. In addition, the most frequent mutations in genes of glutathione synthetase, glutathione peroxidase and glutathione reductase were observed in this group compared to laboratory E.coli. The group of “more resistant” E. coli exhibited differences in Km between 0.3 and 0.8 µM. The number of mutations compared to the laboratory E. coli was substantially lower compared to the other group.
Efficiency of ITS Sequences for DNA Barcoding in Passiflora (Passifloraceae)
Authors: Giudicelli Giovanna , Mäder Geraldo , Brandão de Freitas Loreta
Published: April 2015

DNA barcoding is a technique for discriminating and identifying species using short, variable, and standardized DNA regions. Here, we tested for the first time the performance of plastid and nuclear regions as DNA barcodes in Passiflora. This genus is a largely variable, with more than 900 species of high ecological, commercial, and ornamental importance. We analyzed 1034 accessions of 222 species representing the four subgenera of Passiflora and evaluated the effectiveness of five plastid regions and three nuclear datasets currently employed as DNA barcodes in plants using barcoding gap, applied similarity-, and tree-based methods. The plastid regions were able to identify less than 45% of species, whereas the nuclear datasets were efficient for more than 50% using “best match” and “best close match” methods of TaxonDNA software. All subgenera presented higher interspecific pairwise distances and did not fully overlap with the intraspecific distance, and similarity-based methods showed better results than tree-based methods. The nuclear ribosomal internal transcribed spacer 1 (ITS1) region presented a higher discrimination power than the other datasets and also showed other desirable characteristics as a DNA barcode for this genus. Therefore, we suggest that this region should be used as a starting point to identify Passiflora species.
Role of Long-Range Protein Dynamics in Different Thymidylate Synthase Catalyzed Reactions
Authors: Abeysinghe Thelma , Kohen Amnon
Published: April 2015

Recent studies of Escherichia coli thymidylate synthase (ecTSase) showed that a highly conserved residue, Y209, that is located 8 Å away from the reaction site, plays a key role in the protein’s dynamics. Those crystallographic studies indicated that Y209W mutant is a structurally identical but dynamically altered relative to the wild type (WT) enzyme, and that its turnover catalytic rate governed by a slow hydride-transfer has been affected. The most challenging test of an examination of a fast chemical conversion that precedes the rate-limiting step has been achieved here. The physical nature of both fast and slow C-H bond activations have been compared between the WT and mutant by means of observed and intrinsic kinetic isotope effects (KIEs) and their temperature dependence. The findings indicate that the proton abstraction step has not been altered as much as the hydride transfer step. Additionally, the comparison indicated that other kinetic steps in the TSase catalyzed reaction were substantially affected, including the order of the substrate binding. Enigmatically, although Y209 is H-bonded to 3'-OH of 2'-deoxyuridine-5'-mono­phosphate (dUMP), its altered dynamics is more pronounced on the binding of the remote cofactor, (6R)-N5,N10-methylene-5,6,7,8-tetrahydrofolate (CH2H4folate), revealing the importance of long-range dynamics of the enzymatic complex and its catalytic function.
Correction: Mezei, Z.A., et al; Factor XIII B Subunit Polymorphisms and the Risk of Coronary Artery Disease. Int. J. Mol. Sci. 2015, 16, 1143–1159
Authors: Editorial Office IJMS
Published: April 2015

In the recently published paper [1], Section 2.6 was inadvertently deleted during copyediting. This error was not detected by the handling editor or the authors during proofreading. [...]
Identification of Inhibitors of Biological Interactions Involving Intrinsically Disordered Proteins
Authors: Marasco Daniela , Scognamiglio Pasqualina
Published: April 2015

Protein–protein interactions involving disordered partners have unique features and represent prominent targets in drug discovery processes. Intrinsically Disordered Proteins (IDPs) are involved in cellular regulation, signaling and control: they bind to multiple partners and these high-specificity/low-affinity interactions play crucial roles in many human diseases. Disordered regions, terminal tails and flexible linkers are particularly abundant in DNA-binding proteins and play crucial roles in the affinity and specificity of DNA recognizing processes. Protein complexes involving IDPs are short-lived and typically involve short amino acid stretches bearing few “hot spots”, thus the identification of molecules able to modulate them can produce important lead compounds: in this scenario peptides and/or peptidomimetics, deriving from structure-based, combinatorial or protein dissection approaches, can play a key role as hit compounds. Here, we propose a panoramic review of the structural features of IDPs and how they regulate molecular recognition mechanisms focusing attention on recently reported drug-design strategies in the field of IDPs.
Thermoresponsive Interplay of Water Insoluble Poly(2-alkyl-2-oxazoline)s Composition and Supramolecular Host–Guest Interactions
Authors: R. de la Rosa Victor , Nau Werner , Hoogenboom Richard
Published: April 2015

A series of water insoluble poly[(2-ethyl-2-oxazoline)-ran-(2-nonyl-2-oxazoline)] amphiphilic copolymers was synthesized and their solubility properties in the presence of different supramolecular host molecules were investigated. The resulting polymer-cavitand assemblies exhibited a thermoresponsive behavior that could be modulated by variation of the copolymer composition and length. Interestingly, the large number of hydrophobic nonyl units across the polymer chain induced the formation of kinetically-trapped nanoparticles in solution. These nanoparticles further agglomerate into larger aggregates at a temperature that is dependent on the polymer composition and the cavitand type and concentration. The present research expands the understanding on the supramolecular interactions between water insoluble copolymers and supramolecular host molecules.
Insulin Induces Phosphorylation of Serine Residues of Translationally Controlled Tumor Protein in 293T Cells
Authors: Maeng Jeehye , Kim Miyoung , Lee Hyukjin , Lee Kyunglim
Published: April 2015

Insulin induces the activation of Na,K-ATPase while translationally controlled tumor protein (TCTP) inhibits this enzyme and the associated pump activity. Because binding of insulin with its membrane receptor is known to mediate the phosphorylation of multiple intracellular proteins, phosphorylation of TCTP by insulin might be related to the sodium pump regulation. We therefore examined whether insulin induces TCTP phosphorylation in embryonic kidney 293T cells. Using immunoprecipitation and Western blotting, we found that insulin phosphorylates serine (Ser) residues of TCTP. Following fractionation of the insulin-treated cells into cytosol and membrane fractions, phosphorylated TCTP at its Ser residue (p-Ser-TCTP) was detected exclusively in the cytosolic part and not in the membrane fraction. Phosphorylation of TCTP reached maximum in about 10 min after insulin treatment in 293T cells. In studies of cell-type specificity of insulin-mediated phosphorylation of TCTP, insulin did not phosphorylate TCTP in HeLa cells. Computational prediction and immunoprecipitation using several constructs having Ser to Ala mutation at potential p-Ser sites of TCTP revealed that insulin phosphorylated the serine-9 and -15 residues of TCTP. Elucidations of how insulin-mediated TCTP phosphorylation promotes Na,K-ATPase activation, may offer potential therapeutic approaches to diseases associated with vascular activity and sodium pump dysregulation.
The Interaction between Human Immunodeficiency Virus and Human Papillomaviruses in Heterosexuals in Africa
Authors: Williamson Anna-Lise
Published: April 2015

Sub-Saharan Africa has the highest incidence of human papillomavirus (HPV) and cervical cancer in the world, which is further aggravated by the burden of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) disease with invasive cervical cancer being an AIDS-defining cancer. The prevalence of HPV infection and associated disease is very high in HIV-infected people and continues to be a problem even after anti-retroviral therapy. In the genital tract, the interaction between HPV and HIV is complex, with infection with multiple HPV types reported to make both women and men more susceptible to HIV infection. Besides the national programmes to vaccinate girls against HPV and screen women for cervical cancer, there should be targeted cervical cancer screening, treatment and prevention programmes introduced into HIV treatment centres. There is evidence that in high HIV prevalence areas, HIV-positive women could cause increases in the prevalence of genital HPV infection in HIV-negative men and so increase the HPV circulating in the community. Condom use and circumcision reduce the acquisition of HIV-1, and also to some extent of HPV. This review will highlight what is known about the interaction of HIV and HPV, with an emphasis on research in Africa.
Safety and Efficacy Data on Vaccines and Immunization to Human Papillomavirus
Authors: Kash Natalie , Lee Michael , Kollipara Ramya , Downing Christopher , Guidry Jacqueline , Tyring Stephen
Published: April 2015

Since the discovery of the causal association between human papillomavirus (HPV) and cervical cancer, efforts to develop an effective prophylactic vaccine to prevent high-risk HPV infections have been at the forefront of modern medical research. HPV causes 530,000 cervical cancer cases worldwide, which is the second most common cause of cancer deaths in women; a worldwide collaboration among epidemiologists, molecular biologists, vaccinologists, virologists, and clinicians helped lead to the development of two highly effective prophylactive HPV vaccines. The first, Gardasil, is a quadrivalent vaccine made up of recombinant HPV L1 capsid proteins from the two high-risk HPV types (16/18) responsible for 70% of cervical cancer cases as well as two low-risk HPV types (6/11) which are the causative agent for genital warts. The second, Cervarix, is a bivalent vaccine that was FDA approved three years after Gardasil and is also composed of L1 capsid proteins from HPV types 16/18. This review article focuses on the safety and efficacy data of both FDA-approved vaccines, as well as highlighting a few advances in future HPV vaccines that show promise in becoming additional treatment options for this worldwide disease.
Laser Therapy for Onychomycosis: Fact or Fiction?
Authors: Liddell Lucette , Rosen Ted
Published: April 2015

Onychomycosis is a common fungal infection, afflicting some 10% of the adult population in industrialized countries. Aside from cosmetic concerns, onychomycosis can be the cause of toe and foot pain, as well as the underlying etiology for serious secondary bacterial infections and traumatic ulcerations. In select populations, such as diabetics, the latter conditions may even result in loss of all or part of the lower extremity. Thus, a simple, cost-effective and safe treatment for onychomycosis is highly desirable. Although both topical and oral systemic antifungal agents are available for this purpose, they are not always effective, carry some medical risks, are associated with potentially significant drug-drug interactions, and may be unacceptable to patient and healthcare provider alike. Physical modalities, such as laser therapy, therefore appear appealing. The question is whether laser treatment is sufficiently efficacious and safe to warrant the current high cost per treatment. The readily available literature on this controversy will be reviewed herein.
Covalent Binding of Heparin to Functionalized PET Materials for Improved Haemocompatibility
Authors: Kolar Metod , Mozetič Miran , Stana-Kleinschek Karin , Fröhlich Mirjam , Turk Boris , Vesel Alenka
Published: April 2015

The hemocompatibility of vascular grafts made from poly(ethylene terephthalate) (PET) is insufficient due to the rapid adhesion and activation of blood platelets that occur upon incubation with whole blood. PET polymer was treated with NHx radicals created by passing ammonia through gaseous plasma formed by a microwave discharge, which allowed for functionalization with amino groups. X-ray photoelectron spectroscopy characterization using derivatization with 4-chlorobenzaldehyde indicated that approximately 4% of the –NH2 groups were associated with the PET surface after treatment with the gaseous radicals. The functionalized polymers were coated with an ultra-thin layer of heparin and incubated with fresh blood. The free-hemoglobin technique, which is based on the haemolysis of erythrocytes, indicated improved hemocompatibility, which was confirmed by imaging the samples using confocal optical microscopy. A significant decrease in number of adhered platelets was observed on such samples. Proliferation of both human umbilical vein endothelial cells and human microvascular endothelial cells was enhanced on treated polymers, especially after a few hours of cell seeding. Thus, the technique represents a promising substitute for wet-chemical modification of PET materials prior to coating with heparin.
Heterogeneous Catalysis of Polyoxometalate Based Organic–Inorganic Hybrids
Authors: Ren Yuanhang , Wang Meiyin , Chen Xueying , Yue Bin , He Heyong
Published: April 2015

Organic–inorganic hybrid polyoxometalate (POM) compounds are a subset of materials with unique structures and physical/chemical properties. The combination of metal-organic coordination complexes with classical POMs not only provides a powerful way to gain multifarious new compounds but also affords a new method to modify and functionalize POMs. In parallel with the many reports on the synthesis and structure of new hybrid POM compounds, the application of these compounds for heterogeneous catalysis has also attracted considerable attention. The hybrid POM compounds show noteworthy catalytic performance in acid, oxidation, and even in asymmetric catalytic reactions. This review summarizes the design and synthesis of organic–inorganic hybrid POM compounds and particularly highlights their recent progress in heterogeneous catalysis.
Initial Work on the Characterization of Additive Manufacturing (3D Printing) Using Software Image Analysis
Authors: Straub Jeremy
Published: April 2015

A current challenge in additive manufacturing (commonly known as 3D printing) is the detection of defects. Detection of defects (or the lack thereof) in bespoke industrial manufacturing may be safety critical and reduce or eliminate the need for testing of printed objects. In consumer and prototype printing, early defect detection may facilitate the printer taking corrective measures (or pausing printing and alerting a user), preventing the need to re-print objects after the compounding of a small error occurs. This paper considers one approach to defect detection. It characterizes the efficacy of using a multi-camera system and image processing software to assess printing progress (thus detecting completion failure defects) and quality. The potential applications and extrapolations of this type of a system are also discussed.
Fractional Diffusion in Gaussian Noisy Environment
Authors: Hu Guannan , Hu Yaozhong
Published: April 2015

We study the fractional diffusion in a Gaussian noisy environment as described by the fractional order stochastic heat equations of the following form: \(D_t^{(\alpha)} u(t, x)=\textit{B}u+u\cdot \dot W^H\), where \(D_t^{(\alpha)}\) is the Caputo fractional derivative of order \(\alpha\in (0,1)\) with respect to the time variable \(t\), \(\textit{B}\) is a second order elliptic operator with respect to the space variable \(x\in\mathbb{R}^d\) and \(\dot W^H\) a time homogeneous fractional Gaussian noise of Hurst parameter \(H=(H_1, \cdots, H_d)\). We obtain conditions satisfied by \(\alpha\) and \(H\), so that the square integrable solution \(u\) exists uniquely.
Stability of Chitosan—A Challenge for Pharmaceutical and Biomedical Applications
Authors: Szymańska Emilia , Winnicka Katarzyna
Published: April 2015

Chitosan—one of the natural multifunctional polymers—due to its unique and versatile biological properties is regarded as a useful compound in medical and pharmaceutical technology. Recently, considerable research effort has been made in order to develop safe and efficient chitosan products. However, the problem of poor stability of chitosan-based systems restricts its practical applicability; thus, it has become a great challenge to establish sufficient shelf-life for chitosan formulations. Improved stability can be assessed by controlling the environmental factors, manipulating processing conditions (e.g., temperature), introducing a proper stabilizing compound, developing chitosan blends with another polymer, or modifying the chitosan structure using chemical or ionic agents. This review covers the influence of internal, environmental, and processing factors on the long-term stability of chitosan products. The aim of this paper is also to highlight the latest developments which enable the physicochemical properties of chitosan-based applications to be preserved upon storage.
Recent Advances in Exopolysaccharides from Paenibacillus spp.: Production, Isolation, Structure, and Bioactivities
Authors: Liang Tzu-Wen , Wang San-Lang
Published: April 2015

This review provides a comprehensive summary of the most recent developments of various aspects (i.e., production, purification, structure, and bioactivity) of the exopolysaccharides (EPSs) from Paenibacillus spp. For the production, in particular, squid pen waste was first utilized successfully to produce a high yield of inexpensive EPSs from Paenibacillus sp. TKU023 and P. macerans TKU029. In addition, this technology for EPS production is prevailing because it is more environmentally friendly. The Paenibacillus spp. EPSs reported from various references constitute a structurally diverse class of biological macromolecules with different applications in the broad fields of pharmacy, cosmetics and bioremediation. The EPS produced by P. macerans TKU029 can increase in vivo skin hydration and may be a new source of natural moisturizers with potential value in cosmetics. However, the relationships between the structures and activities of these EPSs in many studies are not well established. The contents and data in this review will serve as useful references for further investigation, production, structure and application of Paenibacillus spp. EPSs in various fields.
Marine Extremophiles: A Source of Hydrolases for Biotechnological Applications
Authors: Dalmaso Gabriel , Ferreira Davis , Vermelho Alane
Published: April 2015

The marine environment covers almost three quarters of the planet and is where evolution took its first steps. Extremophile microorganisms are found in several extreme marine environments, such as hydrothermal vents, hot springs, salty lakes and deep-sea floors. The ability of these microorganisms to support extremes of temperature, salinity and pressure demonstrates their great potential for biotechnological processes. Hydrolases including amylases, cellulases, peptidases and lipases from hyperthermophiles, psychrophiles, halophiles and piezophiles have been investigated for these reasons. Extremozymes are adapted to work in harsh physical-chemical conditions and their use in various industrial applications such as the biofuel, pharmaceutical, fine chemicals and food industries has increased. The understanding of the specific factors that confer the ability to withstand extreme habitats on such enzymes has become a priority for their biotechnological use. The most studied marine extremophiles are prokaryotes and in this review, we present the most studied archaea and bacteria extremophiles and their hydrolases, and discuss their use for industrial applications.
Bioactive Terpenes from Marine-Derived Fungi
Authors: Elissawy Ahmed , El-Shazly Mohamed , Ebada Sherif , Singab AbdelNasser , Proksch Peter
Published: April 2015

Marine-derived fungi continue to be a prolific source of secondary metabolites showing diverse bioactivities. Terpenoids from marine-derived fungi exhibit wide structural diversity including numerous compounds with pronounced biological activities. In this review, we survey the last five years’ reports on terpenoidal metabolites from marine-derived fungi with particular attention on those showing marked biological activities.
Factors Influencing Production of Fusaristatin A in Fusarium graminearum
Authors: Hegge Anne , Lønborg Rikke , Nielsen Ditte , Sørensen Jens
Published: April 2015

Fusarium graminearum is a ubiquitous plant pathogen, which is able to produce several bioactive secondary metabolites. Recently, the cyclic lipopeptide fusaristatin A was isolated from this species and the biosynthetic gene cluster identified. Fusaristatin A consists of a C24 reduced polyketide and the three amino acids dehydroalanine, β-aminoisobutyric acid and glutamine and is biosynthesized by a collaboration of a polyketide synthase and a nonribosomal peptide synthetase. To gain insight into the environmental factors, which controls the production of fusaristatin A, we cultivated F. graminearum under various conditions. We developed an LC-MS/MS method to quantify fusaristatin A in F. graminearum extracts. The results showed that yeast extract sucrose (YES) medium was the best medium for fusaristatin A production and that the optimal pH was 7.5 and temperature 25–30 °C. Furthermore, production of fusaristatin A was more than four times higher in stationary cultures than in agitated cultures when F. graminearum was grown in liquid YES medium. The results also showed that fusaristatin A was only present in the mycelium and not in the liquid, which suggests that fusaristatin A is stored intracellulally and not exported to the extracellular environment.
Use of Phosphate Solubilizing Bacteria to Leach Rare Earth Elements from Monazite-Bearing Ore
Authors: Shin Doyun , Kim Jiwoong , Kim Byung-su , Jeong Jinki , Lee Jae-chun
Published: April 2015

In the present study, the feasibility to use phosphate solubilizing bacteria (PSB) to develop a biological leaching process of rare earth elements (REE) from monazite-bearing ore was determined. To predict the REE leaching capacity of bacteria, the phosphate solubilizing abilities of 10 species of PSB were determined by halo zone formation on Reyes minimal agar media supplemented with bromo cresol green together with a phosphate solubilization test in Reyes minimal liquid media as the screening studies. Calcium phosphate was used as a model mineral phosphate. Among the test PSB strains, Pseudomonas fluorescens, P. putida, P. rhizosphaerae, Mesorhizobium ciceri, Bacillus megaterium, and Acetobacter aceti formed halo zones, with the zone of A. aceti being the widest. In the phosphate solubilization test in liquid media, Azospirillum lipoferum, P. rhizosphaerae, B. megaterium, and A. aceti caused the leaching of 6.4%, 6.9%, 7.5%, and 32.5% of calcium, respectively. When PSB were used to leach REE from monazite-bearing ore, ~5.7 mg/L of cerium (0.13% of leaching efficiency) and ~2.8 mg/L of lanthanum (0.11%) were leached by A. aceti, and Azospirillum brasilense, A. lipoferum, P. rhizosphaerae and M. ciceri leached 0.5–1 mg/L of both cerium and lanthanum (0.005%–0.01%), as measured by concentrations in the leaching liquor. These results indicate that determination of halo zone formation was found as a useful method to select high-capacity bacteria in REE leaching. However, as the leaching efficiency determined in our experiments was low, even in the presence of A. aceti, further studies are now underway to enhance leaching efficiency by selecting other microorganisms based on halo zone formation.
Chemical Compositions and Antioxidant Activities of Polysaccharides from the Sporophores and Cultured Products of Armillaria mellea
Authors: Zhang Shanshan , Liu Xiaoqian , Yan Lihua , Zhang Qiwei , Zhu Jingjing , Huang Na , Wang Zhimin
Published: April 2015

Armillaria mellea is a traditional Chinese medicinal and edible mushroom. Many cultured products of A. mellea have been used to develop commercial medicines in recent years. The chemical composition and activities of the major bioactive chemical components—polysaccharides—may be different because of differences in the raw materials used. Four polysaccharides (SP, CMP, CFBP and CFMP) were obtained from wild sporophores and cultured products (including mycelia, fermentation broth and fermentation mixture) of A. mellea. Their yields, carbohydrate contents, monosaccharide compositions, FT-IR spectra, NMR spectroscopy and antioxidant activities were investigated. All of the polysaccharides were composed of xylose, glucose and galactose without protein. Glucose was the dominant monosaccharide in SP, CMP and CFMP, whereas galactose was the dominant monosaccharide in CFBP. SP and CMP showed higher scavenging DPPH• and ABTS•+ activities and reducing power among four polysaccharides. The carbohydrate content and corresponding glucose percentage were positive influences on the antioxidant activities, whereas the corresponding xylose and galactose percentage were negative influences. A. mellea polysaccharides are potential natural antioxidants. Polysaccharides from cultured products, especially mycelia, are good substitutes for SP and are also potential sources for both dietary supplements and food industries.
Strophalloside Induces Apoptosis of SGC-7901 Cells through the Mitochondrion-Dependent Caspase-3 Pathway
Authors: Zhang Xue-Jiao , Mei Wen-Li , Tan Guang-Hong , Wang Cai-Chun , Zhou Song-Lin , Huang Feng-Ru , Chen Bin , Dai Hao-Fu , Huang Feng-Ying
Published: April 2015

Cardenolides with special chemical structures have been considered as effective anti-cancer drugs in clinic trials. Strophalloside is a cardenolide we recently isolated from Antiaris toxicaria obtained from Hainan, China. The aim of this study was to investigate the possible anticancer effects induced by strophalloside and the underlying molecular mechanism. Gastric carcinoma SGC-7901 cells were treated with strophalloside at various concentrations for different times, and resulting cell viability was determined by the MTT assay, and the motility and invasion of tumor cells were assessed by the Transwell chamber assay. Apoptosis were measured by Annexin V-FITC/PI and Hoechst staining. The changes of mitochondrial transmembrane potential were examined by a JC-1 kit. The expressions of pro-apoptotic protein cytochrome c, caspase-3 and caspase-9 were detected by western blotting analysis. The results showed that strophalloside was capable of reducing cell viability, inhibiting cell growth, and suppressing cell migration and invasion in a time- and dose-dependent manner. Mitochondrial membrane potential declined and the concentration of cytochrome c increased in cytoplasm and caspase-3 and caspase-9 were cleaved into activated states, suggesting that cytochrome c was released from the mitochondrion to cytoplasm and finally activated the caspase-dependent apoptosis pathway. Our results indicate that strophalloside is a potential anticancer drug.
Synthesis and QSAR Study of Novel 6-Chloro-3-(2-Arylmethylene-1-methylhydrazino)-1,4,2-benzodithiazine 1,1-Dioxide Derivatives with Anticancer Activity
Authors: Sławiński Jarosław , Żołnowska Beata , Brzozowski Zdzisław , Kawiak Anna , Belka Mariusz , Bączek Tomasz
Published: April 2015

A series of new 6-chloro-3-(2-arylmethylene-1-methylhydrazino)-1,4,2-benzodithiazine 1,1-dioxide derivatives were effectively synthesized from N-methyl-N-(6-chloro-1,1-dioxo-1,4,2-benzodithiazin-3-yl)hydrazines. The intermediate compounds as well as the products, were evaluated for their cytotoxic effects toward three human cancer cell lines. All compounds shown moderate or weak cytotoxic effects against the tested cancer cell lines, but selective cytotoxic effects were observed. Compound 16 exhibited the most potent cytotoxic activity against the HeLa cell line, with an IC50 value of 10 µM, while 14 was the most active against the MCF-7 and HCT-116 cell lines, affording IC50 values of 15 µM and 16 µM, respectively. The structure-activity relationship was evaluated based on QSAR methodology. The QSAR MCF-7 model indicated that natural charge on carbon atom C13 and energy of highest occupied molecular orbital (HOMO) are highly involved in cytotoxic activity against MCF-7 cell line. The cytotoxic activity of compounds against HCT-116 cell line is dependent on natural charge on carbon atom C13 and electrostatic charge on nitrogen atom N10. The obtained QSAR models could provide guidelines for further development of novel anticancer agents.
A New 9,10-Dihydrophenanthrene and Cell Proliferative 3,4-δ-Dehydrotocopherols from Stemona tuberosa
Authors: Kil Yun-Seo , Park Jiyoung , Han Ah-Reum , Woo Hyun , Seo Eun-Kyoung
Published: April 2015

A new compound, 9,10-dihydro-5-methoxy-8-methyl-2,7-phenanthrenediol (1), was isolated from the roots of Stemona tuberosa Lour. (Stemonaceae) together with two new optically active compounds, (2S,4'R,8'R)-3,4-δ-dehydrotocopherol (2) and (2R,4'R,8'R)-3,4-δ-dehydrotocopherol (3). The structures of compounds 1–3 were determined on the basis of spectroscopic data analysis. Compounds 2 and 3 were each purified from a stereoisomeric mixture of 2 and 3 by preparative HPLC using a chiral column for the first time. The absolute configurations at C-2 of 2 and 3 were determined by Circular Dichroism (CD) experiments. As a part of the research to find natural wound healing agents, all isolates and the mixture of 2 and 3 were evaluated for their cell proliferative effects using a mouse fibroblast NIH3T3 and a HeLa human cervical cancer cell line. As a result, 1, 2, 3, or the mixture of 2 and 3 showed 41.6%, 78.4%, 118.6%, 38.2% increases of cell proliferation in the mouse fibroblast NIH3T3 respectively, compared to 28.4% increase of δ-tocopherol. Moreover, none of them induced cancer cell proliferation. Therefore, 3,4-δ-dehydrotocopherols, especially pure isomers 2 and 3 can be suggested as potential wound healing agents.
Band Structure Simulations of the Photoinduced Changes in the MgB2:Cr Films
Authors: Kityk Iwan , Fedorchuk Anatolii , Ozga Katarzyna , AlZayed Nasser
Published: April 2015

An approach for description of the photoinduced nonlinear optical effects in the superconducting MgB2:Cr2O3 nanocrystalline film is proposed. It includes the molecular dynamics step-by-step optimization of the two separate crystalline phases. The principal role for the photoinduced nonlinear optical properties plays nanointerface between the two phases. The first modified layers possess a form of slightly modified perfect crystalline structure. The next layer is added to the perfect crystalline structure and the iteration procedure is repeated for the next layer. The total energy here is considered as a varied parameter. To avoid potential jumps on the borders we have carried out additional derivative procedure.
Synthesis and Adsorption Property of SiO2@Co(OH)2 Core-Shell Nanoparticles
Authors: Meng Yongde
Published: April 2015

Silica nanoparticles were directly coated with cobalt hydroxide by homogeneous precipitation of slowly decomposing urea in cobalt nitrate solution. The cobalt hydroxide was amorphous, and its morphology was nanoflower-like. The BET (Brunauer-Emmett-Teller) surface area of the core-shell composite was 221 m2/g. Moreover, the possible formation procedure is proposed: the electropositive cobalt ions were first adsorbed on the electronegative silica nanoparticles surface, which hydrolyzed to form cobalt hydroxide nanoparticles. Then, the cobalt hydroxide nanoparticles were aggregated to form nanoflakes. Finally, the nanoflakes self-assembled, forming cobalt hydroxide nanoflowers. Adsorption measurement showed that the core-shell composite exhibited excellent adsorption capability of Rhodamine B (RB).
Biomarkers of Selenium Status
Authors: F. Combs, Jr. Gerald
Published: April 2015

The essential trace element, selenium (Se), has multiple biological activities, which depend on the level of Se intake. Relatively low Se intakes determine the expression of selenoenzymes in which it serves as an essential constituent. Higher intakes have been shown to have anti-tumorigenic potential; and very high Se intakes can produce adverse effects. This hierarchy of biological activities calls for biomarkers informative at different levels of Se exposure. Some Se-biomarkers, such as the selenoproteins and particularly GPX3 and SEPP1, provide information about function directly and are of value in identifying nutritional Se deficiency and tracking responses of deficient individuals to Se-treatment. They are useful under conditions of Se intake within the range of regulated selenoprotein expression, e.g., for humans <55 μg/day and for animals <20 μg/kg diet. Other Se-biomarkers provide information indirectly through inferences based on Se levels of foods, tissues, urine or feces. They can indicate the likelihood of deficiency or adverse effects, but they do not provide direct evidence of either condition. Their value is in providing information about Se status over a wide range of Se intake, particularly from food forms. There is need for additional Se biomarkers particularly for assessing Se status in non-deficient individuals for whom the prospects of cancer risk reduction and adverse effects risk are the primary health considerations. This would include determining whether supranutritional intakes of Se may be required for maximal selenoprotein expression in immune surveillance cells. It would also include developing methods to determine low molecular weight Se-metabolites, i.e., selenoamino acids and methylated Se-metabolites, which to date have not been detectable in biological specimens. Recent analytical advances using tandem liquid chromatography-mass spectrometry suggest prospects for detecting these metabolites.
Low Maternal Vitamin B12 Status Is Associated with Lower Cord Blood HDL Cholesterol in White Caucasians Living in the UK
Authors: Adaikalakoteswari Antonysunil , Vatish Manu , Lawson Alexander , Wood Catherine , Sivakumar Kavitha , McTernan Philip , Webster Craig , Anderson Neil , Yajnik Chittaranjan , Tripathi Gyanendra , Saravanan Ponnusamy
Published: April 2015

Background and Aims: Studies in South Asian population show that low maternal vitamin B12 associates with insulin resistance and small for gestational age in the offspring. Low vitamin B12 status is attributed to vegetarianism in these populations. It is not known whether low B12 status is associated with metabolic risk of the offspring in whites, where the childhood metabolic disorders are increasing rapidly. Here, we studied whether maternal B12 levels associate with metabolic risk of the offspring at birth. Methods: This is a cross-sectional study of 91 mother-infant pairs (n = 182), of white Caucasian origin living in the UK. Blood samples were collected from white pregnant women at delivery and their newborns (cord blood). Serum vitamin B12, folate, homocysteine as well as the relevant metabolic risk factors were measured. Results: The prevalence of low serum vitamin B12 (<191 ng/L) and folate (<4.6 μg/L) were 40% and 11%, respectively. Maternal B12 was inversely associated with offspring’s Homeostasis Model Assessment 2-Insulin Resistance (HOMA-IR), triglycerides, homocysteine and positively with HDL-cholesterol after adjusting for age and BMI. In regression analysis, after adjusting for likely confounders, maternal B12 is independently associated with neonatal HDL-cholesterol and homocysteine but not triglycerides or HOMA-IR. Conclusions: Our study shows that low B12 status is common in white women and is independently associated with adverse cord blood cholesterol.
Enteral Nutrition in Dementia: A Systematic Review
Authors: Brooke Joanne , Ojo Omorogieva
Published: April 2015

The aim of this systematic review is to evaluate the role of enteral nutrition in dementia. The prevalence of dementia is predicted to rise worldwide partly due to an aging population. People with dementia may experience both cognitive and physical complications that impact on their nutritional intake. Malnutrition and weight loss in dementia correlates with cognitive decline and the progress of the disease. An intervention for long term eating difficulties is the provision of enteral nutrition through a Percutaneous Endoscopic Gastrostomy tube to improve both nutritional parameters and quality of life. Enteral nutrition in dementia has traditionally been discouraged, although further understanding of physical, nutritional and quality of life outcomes are required. The following electronic databases were searched: EBSCO Host, MEDLINE, PubMed, Cochrane Database of Systematic Reviews and Google Scholar for publications from 1st January 2008 and up to and including 1st January 2014. Inclusion criteria included the following outcomes: mortality, aspiration pneumonia, pressure sores, nutritional parameters and quality of life. Each study included separate analysis for patients with a diagnosis of dementia and/or neurological disease. Retrospective and prospective observational studies were included. No differences in mortality were found for patients with dementia, without dementia or other neurological disorders. Risk factors for poor survival included decreased or decreasing serum albumin levels, increasing age or over 80 years and male gender. Evidence regarding pneumonia was limited, although did not impact on mortality. No studies explored pressure sores or quality of life.
Quantum Dot Laser for a Light Source of an Athermal Silicon Optical Interposer
Authors: Hatori Nobuaki , Urino Yutaka , Shimizu Takanori , Okano Makoto , Yamamoto Tsuyoshi , Mori Masahiko , Nakamura Takahiro , Arakawa Yasuhiko
Published: April 2015

This paper reports a hybrid integrated light source fabricated on a silicon platform using a 1.3 μm wavelength quantum dot array laser. Temperature insensitive characteristics up to 120 °C were achieved by the optimum quantum dot structure and laser structure. Light output power was obtained that was high enough to achieve an optical error-free link of a silicon optical interposer. Furthermore, we investigated a novel spot size convertor in a silicon waveguide suitable for a quantum dot laser for lower energy cost operation of the optical interposer.