bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Platform and Abutment Angulation on Peri-Implant Bone. A Three-Dimensional Finite Element Stress Analysis
Authors: Martini Ana Paula , Barros Rosália Moreira , Júnior Amilcar Chagas Freitas , Rocha Eduardo Passos , de Almeida Erika Oliveira , Ferraz Cacilda Cunha , Pellegrin Maria Cristina Jimenez , Anchieta Rodolfo Bruniera
Published: October 2012

The aim of this study was to evaluate stress distribution on the peri-implant bone, simulating the influence of Nobel Select implants with straight or angulated abutments on regular and switching platform in the anterior maxilla, by means of 3-dimensional finite element analysis. Four mathematical models of a central incisor supported by external hexagon implant (13 mm × 5 mm) were created varying the platform (R, regular or S, switching) and the abutments (S, straight or A, angulated 15°). The models were created by using Mimics 13 and Solid Works 2010 software programs. The numerical analysis was performed using ANSYS Workbench 10.0. Oblique forces (100 N) were applied to the palatine surface of the central incisor. The bone/implant interface was considered perfectly integrated. Maximum (σmax) and minimum (σmin) principal stress values were obtained. For the cortical bone the highest stress values (σmax) were observed in the RA (regular platform and angulated abutment, 51 MPa), followed by SA (platform switching and angulated abutment, 44.8 MPa), RS (regular platform and straight abutment, 38.6 MPa) and SS (platform switching and straight abutment, 36.5 MPa). For the trabecular bone, the highest stress values (σmax) were observed in the RA (6.55 MPa), followed by RS (5.88 MPa), SA (5.60 MPa), and SS (4.82 MPa). The regular platform generated higher stress in the cervical periimplant region on the cortical and trabecular bone than the platform switching, irrespective of the abutment used (straight or angulated).
Relação conjugal no contexto de reprodução assistida: o tratamento e a gravidez
Authors: Silva Isabela Machado , Lopes Rita de Cássia Sobreira
Published: October 2012

Neste estudo de caso coletivo, investigou-se a relação conjugal de três casais que conceberam com o auxílio das Técnicas de Reprodução Assistida (TRA). Os dados, obtidos a partir de entrevistas individuais semiestruturadas, foram submetidos à análise de conteúdo qualitativa, embasada em três categorias: coesão, sexualidade e comunicação, durante o tratamento e a gravidez. O tratamento mostrou-se fonte potencial de dificuldades nas três dimensões. Durante a gravidez, permaneceram algumas dificuldades, especialmente na sexualidade, mas relataram-se aumento na coesão e redução de conflitos. Identificou-se a interação das três dimensões, de forma que uma pode tanto compensar dificuldades nas demais como contribuir para o funcionamento destas. Destaca-se, assim, a importância de considerar as diferentes dimensões da relação conjugal, em estudos com casais.
Morphology and structure of heat-treated titania nanotubes
Authors: Hosseinpour Pegah M. , Panaitescu Eugen , Lim James , Morris Joshua , Lewis Laura H. , Menon Latika
Published: October 2012

Titania-based nanostructures have gained considerable attention in the past decade due to their potential for enabling energy-related applications, such as catalysis and photovoltaics. Successful development of these materials relies on optimization of their band structure, which is a sensitive function of their local crystal structure and morphology. In this study, a dependence of resultant nanoscale morphology and crystallinity on the postfabrication processing conditions of electrochemically synthesized arrays of titania nanotubes is demonstrated. The as-synthesized nanotubes are amorphous; onset temperature of crystallization to anatase occurs at TC ~280ºC when annealed in oxygen, and at a lower temperature of TC ~250ºC when annealed in an oxygen-deficient atmosphere (N2). However, it is found that annealing in the oxygen-deficient atmosphere causes a transformation of the nanotubular morphology to nanocubes with average dimension of up to 0·02 μm3, based on scanning electron microscopy data, leaving a porous tubular morphology behind. However, annealing in pure oxygen maintains the original tubular architecture. This study reveals the importance of postfabrication processing design to develop nanomaterials with tailored crystal structure and morphology, which in turn is critical for the optimization of the optical and transport properties for various energy-related applications.
Lateral force distribution on base-isolated structures under near-field earthquakes
Authors: Khoshnoudian Faramarz , Esrafili Saeed
Published: October 2012

In the current paper the accuracy of the International Building Code equivalent static method for base-shear distribution is evaluated to determine the response of seismically isolated structures under near-field earthquakes. For this purpose two-, three-, four- and six-storey building models are designed according to the equivalent lateral-response procedure for different elastomeric isolation systems of 2 s, 2·5 s and 3 s for periods of isolated structures and 6%, 8% and 11% for their damping ratio. Different lateral-force resisting systems such as ordinary steel moment frame, ordinary steel concentrically braced frame and ordinary reinforced concrete shear wall are employed as a superstructure and the effects of 13 near-field ground motions on vertical seismic force distribution, and the linear and non-linear properties of isolation systems are investigated. The results of the equivalent static procedure in vertical distribution of base shear are compared with results obtained from dynamic linear and non-linear analysis and the efficiency of their application is studied. Based on linear and non-linear dynamic analysis results of isolated structures, two new formulae are proposed for vertical distribution of base shear for the isolated structures under near field earthquakes. The proposed linear formula is based on the first mode shape of an isolated structure and the non-linear formula follows three first mode shapes which implies contribution of higher modes in more realistic non-linear analyses.
Conducting Ethically Sound Disaster Nursing Research
Authors: Shafer Michaela R. , Stocks Laurel
Published: October 2012

Health care professionals have always faced the threat of catastrophic disaster and pandemic infectious illness but have continued to practice without adequately considering the ethical consequences of many of the decision-making tools we currently have in place. Lack of research on these ethical decisions in the face of disasters regarding the 3Rs—rationing (triage and allocating scarce resources), restrictions (quarantine and the denial of care based on some criteria or the magnitude of the disaster), and responsibility (duty to treat and duty to report for work)—will leave nurses to make decisions in the throws of disaster rather than before the crisis occurs. This chapter focuses on conducting ethically sound nursing research in disasters. A survey of the literature on the topic to include current research on the 3Rs, frameworks, and methodological problems will be examined. This chapter concludes with a call to action for the nursing profession to accept their role as patient advocates and drive the research necessary to avoid the ethical pitfalls seen in recent disaster decisions and scenarios.
Target-Based Drug Discovery for Malaria, Leishmaniasis, and Trypanosomiasis
Authors: Werbovetz Karl A.
Published: October 2012

Advances in combinatorial chemistry, high-throughput screening, and molecular modeling have revolutionized the process of drug discovery in the pharmaceutical industry. Drug discovery efforts for the primary protozoal parasitic diseases of the developing world, malaria, leishmaniasis, and trypanosomiasis, have also begun to employ these tech-niques. Drug targets in these parasites, exemplified by cysteine proteases and trypanothione reductase, have been purified and used for inhibitor screening. Through this work, small molecules have been identified that inhibit both parasite proteins and the growth of the organisms. This review describes advances that have been made in examining the effects of small molecules on potential parasitic drug targets determined by biochemical and computer-based screening, and also details the activity of such compounds on parasites in vitro and in vivo. Based on these results, it is apparent that modern drug discovery techniques hold promise for the identification of antiparasitic drug candidates.
Inhibition of Transglycosylation Involved in Bacterial Peptidoglycan Synthesis
Authors: Goldman Robert C. , Gange David
Published: October 2012

The continuing specter of resistance to antimicrobial agents has driven a sustained search for new agents that possess activity on drug resistant bacteria. Although several paths are available to reach this goal, the most generalized would be the discovery and clinical development of an agent that acts on a new target which has not yet experienced selective pre-ssure in the clinical setting. Such a target should be essential to the growth and survival of bacteria, and sufficiently different from, or better still non-existent in, the human host. The transglycosylation reaction that polymerizes biochemical intermediates into peptidoglycan qualifies as such a target. This biochemical system accepts the basic unit N-acetylglucosamine-b-1,4- N-acetyl-muramyl-pentapeptide-pyrophosphoryl-undecaprenol (lipid II), and leads to polymerization of the N-acetylglucosamine -b-1,4-N-acetyl-muramyl-pentapeptide segment into peptidoglycan. Approaches to targeting this reaction include modification of known glycolipid and glycopeptide natural product antibiotics. The synthesis and antibacterial activity of synthetic analogs of moenomycin having novel antibacterial activities not present in the parent structure will be presented, together with the combinatorial chemistry and assay systems leading to their discovery. Likewise, we will discuss chemical modifications to specific glycopeptide antibiotics that have extended their spectrum to include vancomycin resistant enterococci that substitute D-alanyl-D-lactate for D-alanyl-D-alanine in their peptidoglycan. Two differing theories, one positing the generation of high affinity, specific binding to D-alanyl-D-lactate via glycopeptide dimerization and/or membrane anchoring, and the other supporting direct targeting of the modified glycopeptide to the transglycosylation complex, seek to explain the mechanism of action on vancomycin resistant enterococci. Biochemical evidence in support of these two theories will be discussed.
Exploring the Nature of Molecular Recognition in Nicotinic Acetylcholine Receptors
Authors: Schmitt Jeffrey D.
Published: October 2012

Nicotinic acetylcholine receptors (nAChRs) are the subject of ever increasing interest because of their presumed involvement in the etiology of numerous clinical disorders. Unfortunately, the absence of atomic-level structural data, as well as the pharmacological complexity of these receptors leaves many fundamental questions unanswered. An understanding of how ligands interact with the receptor and, in-turn, how these interactions lead to pharmacological effect is vital in the advancement of nAChR-based therapeutics. We will first explore physico-chemical themes that are evidenced to be of particular importance in nAChR molecular recognition; these are- p-cation interaction, conformational entropy and stereochemistry. The second objective of this review is an interpretive encapsulation of the extensive and disparate body of structure-activity data that now exists for nAChRs. Finally, this review will advocate a re-investigation of distance geometry based methods as well as the need for additional approaches in nicotinic receptor pharmacophore generation.
Sex Steroids and the Endothelium
Authors: Schnaper H. William , McGuire John , Runyan Constance , Hubchak Susan C.
Published: October 2012

Gonadal steroids clearly influence the course of atherosclerotic cardiovascular disease in women. This observation has suggested that these hormones have beneficial effects on the physiology of the vascular wall. Increased arterial vascular caliber after estrogen treatment, decreased lipid levels in subjects receiving hormone replacement therapy, and the markedly decreased extent of atherosclerotic plaque formation in young women as compared with young men support a cardioprotective effect of ovarian steroids. Generally, it appears that the effects of 17b-estradiol are particularly beneficial, and the mechanism of action is targeted largely to the endothelial cell. This review describes the evidence for positive effects of estrogens on endothelial cell biology and considers potential mechanisms for estrogen actions on endothelial cell signal transduction.
Steroids and the Endometrium
Authors: Oehler Martin K. , Rees Margaret C.P. , Bicknell Roy
Published: October 2012

Abstract: Steroids are commonly employed in current clinical practice. The benefits of steroids in hormone replacement therapy, contraception and prevention or treatment of breast cancer are limited by their side effects arising from disorders in endometrial function. These side effects are complex and enclose bleeding problems and endometrial proliferation during hormone replacement therapy and antioestrogen treatment or menstrual disturbances during oral contraception. Numerous reports have identified gene targets influenced by steroids and have implicated these products as contributors to endometrial physiology or pathology. The expression of estrogen and progesterone receptors is regulated by steroids. The new estrogen receptor (ER) subtype ERb with different functional characteristics from ERa was recently described in endometrium. In addition, there is now increasing evidence that the functionally distinct progesterone receptor (PR) isoforms A and B are differentially expressed in this tissue. The relative proportions of these steroid receptors and their interaction determine the expression of specific genes upon steroidal stimulation. Steroids induce endometrial expression of various growth and angiogenic factors. Dysregulations of this steroid modulated expression is believed to be involved in the pathogenesis of many endometrial diseases. Irregular bleeding induced by steroidal contraception, for example, is thought to involve aberrant endometrial vascular development and expression of angiogenic growth factors. The antioestrogen tamoxifen induces growth factors like vascular endothelial growth factor and adrenomedullin which may be key mediators of endometrial neoplastic effects. This review describes recent advances regarding the mechanism of action of steroids on endometrium. The expression of oestrogen and progesterone receptors as well as steroid hormone dependent growth factors and angiogenic modulators are going to be discussed.
Approaches to the Design of Effective HIV-1 Protease Inhibitors
Authors: Lebon F. , Ledecq M.
Published: October 2012

Recently, western countries have recorded a decrease in the death rate imputed to AIDS. This success has been largely attributed to the presence on the market of chemotherapies that inhibit the infectivity of the predominant causative agent, the HIV-1 virus, by targeting essential viral enzymes. One of these is the protease (HIV-1 PR) whose activity is a prerequisite for viral replication. Two main sites have been identified as poten-tial targets for the inhibition of HIV-1 PR, the active site and the interface, the latter being largely responsible for the stabilization of the enzyme dimeric structure. The compounds that have reached clinical application so far target the active site of HIV-1 PR. These molecules act as transition state analogues and result from modifications of the peptidic scaffold into peptidomimetics. In order to improve their bioavailability, systematic biological screening and de novo design have been used to suggest new non-peptide inhibitors combining both antiviral potency and favorable pharmacokinetic properties. In parallel, compounds targeting other potential sites of inhibition have been tested. Peptides and peptidomimetics based on the terminal sequence of the enzyme, a site which is proposed to be less susceptible to mutations, have been shown to lead to HIV-1 PR inactivation. Cupric ion was described to bind a sequence on the protease surface, which includes cysteine and histidine residues, leading to the inhibition of the enzyme. In the future, these non-active site inhibitors could provide an alternative in anti-HIV drug combination strategies.
Characterization of Sulfur in Raw and Anaerobically Digested Municipal Wastewater Treatment Sludges
Authors: Du Weiwei , Parker Wayne
Published: October 2012

A microwave‐enhanced acid digestion method that was integrated with inductively coupled plasma‐atomic emission spectrometry was developed and validated for determining total, soluble, and precipitated sulfur in wastewater treatment sludges. The coefficient of variation of this method was less than 4.0%. The recovery of dosed sulfur from sludge samples was between 97.1% and 100.5%. The composition of sulfur in primary and waste‐activated sludge (WAS) before and after anaerobic digestion at 35 and 55 °C was characterized by employing this developed method. There was not an apparent relationship between the precipitated sulfur and nonsoluble iron concentrations in sludges. Raw WAS had a more consistent organic sulfur fractionation because of its relatively homogeneous composition. The organic‐sulfur‐containing components (proteins) of WAS had reduced degradability as compared with that in primary sludge during anaerobic digestion. Digestion at 55 °C increased solubilization but not ultimate conversion of organic sulfur in sludge.
Wastewater Collection Systems
Authors: Vallabhaneni Srinivas
Published: October 2012

A review of the literature published in 2011 on topics relating to wastewater collection systems is presented. This review is divided into the following sections: sewer system evaluation/modeling/RTC, sewer condition and rehabilitation assessment, green infrastructure, system design, operation/maintenance, regulatory issues, and asset and risk management. Synthesized, analyzed, and comprehensive material related to these wastewater collection system topics selected from major literature sources are presented in this review.
Physico‐Chemical Processes
Authors: Chelme‐Ayala Pamela , Afzal Atefeh , Ding Ning , Moustafa Ahmed M.A. , Pourrezaei Parastoo , Alpatova Alla , Drzewicz Przemysław , Hwang Geelsu , Kim Eun‐Sik , Liu Yang , El‐Din Mohamed Gamal
Published: October 2012

This review of the literature published in 2011 deals with the physico‐chemical processes used for water and wastewater treatment. The review is divided into seven sections, including coagulation/flocculation, sorption processes, filtration, sedimentation, flotation, oxidation, and air stripping.
Anaerobic Processes
Authors: Kasiri Sepideh , Mah Fraser , Zhang Chonggang , Haveroen Melissa , Ellsworth Scott , Ulrich Ania
Published: October 2012

The anaerobic processes literature review contains a comprehensive discussion of articles published in 2011, including both original research and review articles. Specific attention is paid to studies on design and optimization of systems using anaerobic processes, as well as characterizing the microflora involved in such processes. This year's anaerobic processes literature review is divided into the following sections: biogas treatment and use, integrated approaches, modeling advances, process technology, hydrogen production, microbiology, anammox, treatability studies, and toxicity.
Biosolids and Sludge Management
Authors: Brisolara Kari F.
Published: October 2012

This review section covers journal articles and conference papers related to biosolids and sludge management that were published in 2011. The literature review has been divided into the following sections:  • Biosolids regulations and management issues,  • Biosolids characteristics and measurement including microconstituents, metals and pathogens,  • Sludge treatment technologies including pretreatment and sludge minimization, conditioning and dewatering, anaerobic digestion, aerobic digestion, composting,  • Disposal and reuse including combustion/incineration, land application and innovative alternatives for reuse,  • Odor and air emissions, and  • Risk analysis
Agricultural Wastes
Authors: Zhang Zhenyuan , Gonzalez Andrea M. , Davies Evan G. R. , Liu Yang
Published: October 2012

Agricultural wastes have become an increasing concern in recent years, as they may cause significant environmental problems; however, they may also be used for several beneficial purposes, as feed stock for energy production, and for chemical recovery and chemical or dye adsorption. This review is divided into the following four sections: agricultural waste characterization, waste reuse and recycling, waste treatment, and waste management and minimization.
Substratum‐Associated Microbiota
Authors: Francoeur Steven N. , Sander Bianca , Liess Antonia
Published: October 2012

A review of the literature published in 2011 on topics relating to on the subject of ecology of substratum‐associated microbiota (algae, bacteria, and fungi). We also highlighted some of the new methods that can be applied to the study of substratum‐associated microbiota and included newly described taxa.
Effects of Pollution on Marine Organisms
Authors: Mearns Alan J. , Reish Donald J. , Oshida Philip S. , Ginn Thomas , Rempel‐Hester Mary Ann , Arthur Courtney
Published: October 2012

This review covers selected 2011 articles on the biological, chemical and physical effects of natural and anthropogenic pollutants on marine and estuarine plants and animals. The review, based largely on journal articles, covers field and laboratory measurement activities (concentrations of contaminants, field surveys, toxicity testing and biomarkers). Reviewed papers focus further on pollution issues of current interest including endocrine disrupters, wastewater discharges, dredging and disposal, etc. Special emphasis is placed on oil spills and marine debris due in part to the catastrophic Deepwater Horizon blowout in the Gulf of Mexico and ongoing cleanup and the 2011 Japanese tsunami. Several topical areas reviewed in the past were dropped this year due to circumstances beyond our control. Further, the focus is on effects, not pollutant fate and transport. There is considerable overlap across subject areas (e.g. some bioaccumulation papers may be cited in other topical categories). As always, readers should only use this as a guide and must consult the original papers before citing them, including double‐checking units.
Ecological and Human Health Risk Assessment
Authors: Biksey Tom , Schultz Amy Couch , Bernhardt Aaron , Peterson Chrissy , Taylor Kelly
Published: October 2012

This literature review covers the risk assessment process and addresses both ecological and human receptors. The review covers the risk assessment literature including methodology, analysis, interpretation, management, uncertainty, policy, and regulatory guidance. The review is divided into ecological and human health sections. The focus of the review is on the risk assessment process as it is applied to ecological systems and human health, site investigation and remediation, and natural resources. The objective is to provide an overview of the scope of the literature published in 2011.
Insider Trading, Litigation Concerns, and Auditor Going-Concern Opinions
Authors: Chen Chen , Martin Xiumin , Wang Xin
Published: October 2012

We investigate whether insider selling affects the likelihood of firms receiving auditor going-concern opinions. Prior studies document significant negative market reactions to the issuance of going-concern opinions, indicating that such opinions convey bad news to investors. Insider sales followed by negative news are likely to attract regulators' scrutiny and investor class-action lawsuits. Therefore, we predict that, to reduce the risk of litigation, managers have incentives to avoid receiving going-concern opinions after their insider sales by pressuring auditors for clean audit opinions. We evaluate this prediction empirically and find that the probability of receiving a going-concern opinion is negatively associated with the level of insider selling. Further analysis indicates that this negative relation is more pronounced for firms that are economically significant to their auditors but less pronounced when (1) auditors have concerns about litigation exposure and reputation loss and (2) audit committees are more independent. Finally, the negative relation between going-concern opinions and insider sales is significantly weakened after SOX.

JEL Classifications: G18; M42; G48.
Preserving Yeast Genetic Heritage through DNA Damage Checkpoint Regulation and Telomere Maintenance
Authors: Baldo Veronica , Liang Jason , Wang Guoliang , Zhou Huilin
Published: October 2012

In order to preserve genome integrity, extrinsic or intrinsic DNA damages must be repaired before they accumulate in cells and trigger other mutations and genome rearrangements. Eukaryotic cells are able to respond to different genotoxic stresses as well as to single DNA double strand breaks (DSBs), suggesting highly sensitive and robust mechanisms to detect lesions that trigger a signal transduction cascade which, in turn, controls the DNA damage response (DDR). Furthermore, cells must be able to distinguish natural chromosomal ends from DNA DSBs in order to prevent inappropriate checkpoint activation, DDR and chromosomal rearrangements. Since the original discovery of RAD9, the first DNA damage checkpoint gene identified in Saccharomyces cerevisiae, many genes that have a role in this pathway have been identified, including MRC1, MEC3, RAD24, RAD53, DUN1, MEC1 and TEL1. Extensive studies have established most of the genetic basis of the DNA damage checkpoint and uncovered its different functions in cell cycle regulation, DNA replication and repair, and telomere maintenance. However, major questions concerning the regulation and functions of the DNA damage checkpoint remain to be answered. First, how is the checkpoint activity coupled to DNA replication and repair? Second, how do cells distinguish natural chromosome ends from deleterious DNA DSBs? In this review we will examine primarily studies performed using Saccharomyces cerevisiae as a model system.
Striatal Volume Increases in Active Methamphetamine-Dependent Individuals and Correlation with Cognitive Performance
Authors: Jan Reem , Lin Joanne , Miles Sylvester , Kydd Rob , Russell Bruce
Published: October 2012

The effect of methamphetamine (MA) dependence on the structure of the human brain has not been extensively studied, especially in active users. Previous studies reported cortical deficits and striatal gains in grey matter (GM) volume of abstinent MA abusers compared with control participants. This study aimed to investigate structural GM changes in the brains of 17 active MA-dependent participants compared with 20 control participants aged 18–46 years using voxel-based morphometry and region of interest volumetric analysis of structural magnetic resonance imaging data, and whether these changes might be associated with cognitive performance. Significant volume increases were observed in the right and left putamen and left nucleus accumbens of MA-dependent compared to control participants. The volumetric gain in the right putamen remained significant after Bonferroni correction, and was inversely correlated with the number of errors (standardised z-scores) on the Go/No-go task. MA-dependent participants exhibited cortical GM deficits in the left superior frontal and precentral gyri in comparison to control participants, although these findings did not survive correction for multiple comparisons. In conclusion, consistent with findings from previous studies of abstinent users, active chronic MA-dependent participants showed significant striatal enlargement which was associated with improved performance on the Go/No-go, a cognitive task of response inhibition and impulsivity. Striatal enlargement may reflect the involvement of neurotrophic effects, inflammation or microgliosis. However, since it was associated with improved cognitive function, it is likely to reflect a compensatory response to MA-induced neurotoxicity in the striatum, in order to maintain cognitive function. Follow-up studies are recommended to ascertain whether this effect continues to be present following abstinence. Several factors may have contributed to the lack of more substantial cortical and subcortical GM changes amongst MA-dependent participants, including variability in MA exposure variables and difference in abstinence status from previous studies.
A Comparison of Wind Flow Models for Wind Resource Assessment in Wind Energy Applications
Authors: Gasset Nicolas , Landry Mathieu , Gagnon Yves
Published: October 2012

The objective of this work was to assess the accuracy of various coupled mesoscale-microscale wind flow modeling methodologies for wind energy applications. This is achieved by examining and comparing mean wind speeds from several wind flow modeling methodologies with observational measurements from several 50 m met towers distributed across the study area. At the mesoscale level, with a 5 km resolution, two scenarios are examined based on the Mesoscale Compressible Community Model (MC2) model: the Canadian Wind Energy Atlas (CWEA) scenario, which is based on standard input data, and the CWEA High Definition (CWEAHD) scenario where high resolution land cover input data is used. A downscaling of the obtained mesoscale wind climate to the microscale level is then performed, where two linear microscale models, i.e., MsMicro and the Wind Atlas Analysis and Application Program (WAsP), are evaluated following three downscaling scenarios: CWEA-WAsP, CWEA-MsMicro and CWEAHD-MsMicro. Results show that, for the territory studied, with a modeling approach based on the MC2 and MsMicro models, also known as Wind Energy Simulation Toolkit (WEST), the use of high resolution land cover and topography data at the mesoscale level helps reduce modeling errors for both the mesoscale and microscale models, albeit only marginally. At the microscale level, results show that the MC2-WAsP modeling approach gave substantially better results than both MC2 and MsMicro modeling approaches due to tweaked meso-micro coupling.
Injurious Effects of Emodin on Maturation of Mouse Oocytes, Fertilization and Fetal Development via Apoptosis
Authors: Chang Mei-Hui , Chang Shao-Chung , Chan Wen-Hsiung
Published: October 2012

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a major constituent of rhubarb, has a wide range of therapeutic applications. Previous studies have established that emodin induces apoptosis in the inner cell mass and trophectoderm of mouse blastocysts and leads to decreased embryonic development and viability, indicating a role as an injury risk factor for normal embryonic development. However, the mechanisms underlying its hazardous effects have yet to be characterized. In the current study, we further investigated the effects of emodin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, emodin induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with emodin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments using an in vivo mouse model disclosed that consumption of drinking water containing 20–40 μM emodin led to decreased oocyte maturation and in vitro fertilization, as well as early embryonic developmental injury. Notably, pretreatment with a caspase-3-specific inhibitor effectively prevented emodin-triggered injury effects, suggesting that impairment of embryo development occurs via a caspase-dependent apoptotic process.
The Proteomics Big Challenge for Biomarkers and New Drug-Targets Discovery
Authors: Savino Rocco , Paduano Sergio , Preianò Mariaimmacolata , Terracciano Rosa
Published: October 2012

In the modern process of drug discovery, clinical, functional and chemical proteomics can converge and integrate synergies. Functional proteomics explores and elucidates the components of pathways and their interactions which, when deregulated, lead to a disease condition. This knowledge allows the design of strategies to target multiple pathways with combinations of pathway-specific drugs, which might increase chances of success and reduce the occurrence of drug resistance. Chemical proteomics, by analyzing the drug interactome, strongly contributes to accelerate the process of new druggable targets discovery. In the research area of clinical proteomics, proteome and peptidome mass spectrometry-profiling of human bodily fluid (plasma, serum, urine and so on), as well as of tissue and of cells, represents a promising tool for novel biomarker and eventually new druggable targets discovery. In the present review we provide a survey of current strategies of functional, chemical and clinical proteomics. Major issues will be presented for proteomic technologies used for the discovery of biomarkers for early disease diagnosis and identification of new drug targets.
Novel High-Viscosity Polyacrylamidated Chitosan for Neural Tissue Engineering: Fabrication of Anisotropic Neurodurable Scaffold via Molecular Disposition of Persulfate-Mediated Polymer Slicing and Complexation
Authors: Kumar Pradeep , Choonara Yahya E. , Toit Lisa C. du , Modi Girish , Naidoo Dinesh , Pillay Viness
Published: October 2012

Macroporous polyacrylamide-grafted-chitosan scaffolds for neural tissue engineering were fabricated with varied synthetic and viscosity profiles. A novel approach and mechanism was utilized for polyacrylamide grafting onto chitosan using potassium persulfate (KPS) mediated degradation of both polymers under a thermally controlled environment. Commercially available high molecular mass polyacrylamide was used instead of the acrylamide monomer for graft copolymerization. This grafting strategy yielded an enhanced grafting efficiency (GE = 92%), grafting ratio (GR = 263%), intrinsic viscosity (IV = 5.231 dL/g) and viscometric average molecular mass (MW = 1.63 × 106 Da) compared with known acrylamide that has a GE = 83%, GR = 178%, IV = 3.901 dL/g and MW = 1.22 × 106 Da. Image processing analysis of SEM images of the newly grafted neurodurable scaffold was undertaken based on the polymer-pore threshold. Attenuated Total Reflectance-FTIR spectral analyses in conjugation with DSC were used for the characterization and comparison of the newly grafted copolymers. Static Lattice Atomistic Simulations were employed to investigate and elucidate the copolymeric assembly and reaction mechanism by exploring the spatial disposition of chitosan and polyacrylamide with respect to the reactional profile of potassium persulfate. Interestingly, potassium persulfate, a peroxide, was found to play a dual role initially degrading the polymers—“polymer slicing”—thereby initiating the formation of free radicals and subsequently leading to synthesis of the high molecular mass polyacrylamide-grafted-chitosan (PAAm-g-CHT)—“polymer complexation”. Furthermore, the applicability of the uniquely grafted scaffold for neural tissue engineering was evaluated via PC12 neuronal cell seeding. The novel PAAm-g-CHT exhibited superior neurocompatibility in terms of cell infiltration owing to the anisotropic porous architecture, high molecular mass mediated robustness, superior hydrophilicity as well as surface charge due to the acrylic chains. Additionally, these results suggested that the porous PAAm-g-CHT scaffold may act as a potential neural cell carrier.
Superoxide Dismutase as a Novel Macromolecular Nitric Oxide Carrier: Preparation and Characterization
Authors: Chen Ssu-Han , Chiu Shih-Jiuan , Hu Teh-Min
Published: October 2012

Nitric oxide (NO) is an important molecule that exerts multiple functions in biological systems. Because of the short-lived nature of NO, S-nitrosothiols (RSNOs) are believed to act as stable NO carriers. Recently, sulfhydryl (SH) containing macromolecules have been shown to be promising NO carriers. In the present study, we aimed to synthesize and characterize a potential NO carrier based on bovine Cu,Zn-superoxide dismutase (bSOD). To prepare S-nitrosated bSOD, the protein was incubated with S-nitrosoglutathione (GSNO) under varied experimental conditions. The results show that significant S-nitrosation of bSOD occurred only at high temperature (50 °C) for prolonged incubation time (>2 h). S-nitrosation efficiency increased with reaction time and reached a plateau at ~4 h. The maximum amount of NO loaded was determined to be about 0.6 mol SNO/mol protein (~30% loading efficiency). The enzymatic activity of bSOD, however, decreased with reaction time. Our data further indicate that NO functionality can only be measured in the presence of extremely high concentrations of Hg2+ or when the protein was denatured by guanidine. Moreover, mildly acidic pH was shown to favor S-nitrosation of bSOD. A model based on unfolding and refolding of bSOD during preparation was proposed to possibly explain our observation.
Bacterial Exopolysaccharides: Functionality and Prospects
Authors: Nwodo Uchechukwu U. , Green Ezekiel , Okoh Anthony I.
Published: October 2012

Diverse structural, functional and valuable polysaccharides are synthesized by bacteria of all taxa and secreted into the external environment. These polysaccharides are referred to as exopolysaccharides and they may either be homopolymeric or heteropolymeric in composition and of diverse high molecular weights (10 to 1000 kDa). The material properties of exopolysaccharides have revolutionized the industrial and medical sectors due to their retinue of functional applications and prospects. These applications have been extensive in areas such as pharmacological, nutraceutical, functional food, cosmeceutical, herbicides and insecticides among others, while prospects includes uses as anticoagulant, antithrombotic, immunomodulation, anticancer and as bioflocculants. Due to the extensive applications of bacterial exopolysaccharides, this overview provides basic information on their physiologic and morphologic functions as well as their applications and prospects in the medical and industrial sectors.
The Making of a CYP3A Biomarker Panel for Guiding Drug Therapy
Authors: Wang Danxin , Sadee Wolfgang
Published: October 2012

CYP3A ranks among the most abundant cytochrome P450 enzymes in the liver, playing a dominant role in metabolic elimination of clinically used drugs. A main member in CYP3A family, CYP3A4 expression and activity vary considerably among individuals, attributable to genetic and non-genetic factors, affecting drug dosage and efficacy. However, the extent of genetic influence has remained unclear. This review assesses current knowledge on the genetic factors influencing CYP3A4 activity. Coding region CYP3A4 polymorphisms are rare and account for only a small portion of inter-person variability in CYP3A metabolism. Except for the promoter allele CYP3A4*1B with ambiguous effect on expression, common CYP3A4 regulatory polymorphisms were thought to be lacking. Recent studies have identified a relatively common regulatory polymorphism, designated CYP3A4*22 with robust effects on hepatic CYP3A4 expression. Combining CYP3A4*22 with CYP3A5 alleles *1, *3 and *7 has promise as a biomarker predicting overall CYP3A activity. Also contributing to variable expression, the role of polymorphisms in transcription factors and microRNAs is discussed.
Insurance Coverage Policies for Personalized Medicine
Authors: Hresko Andrew , Haga Susanne B.
Published: October 2012

Adoption of personalized medicine in practice has been slow, in part due to the lack of evidence of clinical benefit provided by these technologies. Coverage by insurers is a critical step in achieving widespread adoption of personalized medicine. Insurers consider a variety of factors when formulating medical coverage policies for personalized medicine, including the overall strength of evidence for a test, availability of clinical guidelines and health technology assessments by independent organizations. In this study, we reviewed coverage policies of the largest U.S. insurers for genomic (disease-related) and pharmacogenetic (PGx) tests to determine the extent that these tests were covered and the evidence basis for the coverage decisions. We identified 41 coverage policies for 49 unique testing: 22 tests for disease diagnosis, prognosis and risk and 27 PGx tests. Fifty percent (or less) of the tests reviewed were covered by insurers. Lack of evidence of clinical utility appears to be a major factor in decisions of non-coverage. The inclusion of PGx information in drug package inserts appears to be a common theme of PGx tests that are covered. This analysis highlights the variability of coverage determinations and factors considered, suggesting that the adoption of personal medicine will affected by numerous factors, but will continue to be slowed due to lack of demonstrated clinical benefit.
Platinum-Group Minerals in Chromitites of the Niquelândia Layered Intrusion (Central Goias, Brazil): Their Magmatic Origin and Low-Temperature Reworking during Serpentinization and Lateritic Weathering
Authors: Garuti Giorgio , Zaccarini Federica , Proenza Joaquin , Thalhammer Oskar , Angeli Nelson
Published: October 2012

A variety of platinum-group-minerals (PGM) have been found to occur associated with the chromitite and dunite layers in the Niquelândia igneous complex. Two genetically distinct populations of PGM have been identified corresponding to phases crystallized at high temperatures (primary), and others formed or modified during post-magmatic serpentinization and lateritic weathering (secondary). Primary PGM have been found in moderately serpentinized chromitite and dunite, usually included in fresh chromite grains or partially oxidized interstitial sulfides. Due to topographically controlled lateritic weathering, the silicate rocks are totally transformed to a smectite-kaolinite-garnierite-amorphous silica assemblage, while the chromite is changed into a massive aggregate of a spinel phase having low-Mg and a low Fe3+/Fe2+ ratio, intimately associated with Ti-minerals, amorphous Fe-hydroxides, goethite, hematite and magnetite. The PGM in part survive alteration, and in part are corroded as a result of deep chemical weathering. Laurite is altered to Ru-oxides or re-crystallizes together with secondary Mg-ilmenite. Other PGM, especially the Pt-Fe alloys, re-precipitate within the altered chromite together with kaolinite and Fe-hydroxides. Textural evidence suggests that re-deposition of secondary PGM took place during chromite alteration, controlled by variation of the redox conditions on a microscopic scale.
A Robust Static Decoupling Algorithm for 3-Axis Force Sensors Based on Coupling Error Model and ε-SVR
Authors: Ma Junqing , Song Aiguo , Xiao Jing
Published: October 2012

Coupling errors are major threats to the accuracy of 3-axis force sensors. Design of decoupling algorithms is a challenging topic due to the uncertainty of coupling errors. The conventional nonlinear decoupling algorithms by a standard Neural Network (NN) are sometimes unstable due to overfitting. In order to avoid overfitting and minimize the negative effect of random noises and gross errors in calibration data, we propose a novel nonlinear static decoupling algorithm based on the establishment of a coupling error model. Instead of regarding the whole system as a black box in conventional algorithm, the coupling error model is designed by the principle of coupling errors, in which the nonlinear relationships between forces and coupling errors in each dimension are calculated separately. Six separate Support Vector Regressions (SVRs) are employed for their ability to perform adaptive, nonlinear data fitting. The decoupling performance of the proposed algorithm is compared with the conventional method by utilizing obtained data from the static calibration experiment of a 3-axis force sensor. Experimental results show that the proposed decoupling algorithm gives more robust performance with high efficiency and decoupling accuracy, and can thus be potentially applied to the decoupling application of 3-axis force sensors.
Catalytic and Inhibitory Kinetic Behavior of Horseradish Peroxidase on the Electrode Surface
Authors: Huang Jitao , Huang Wei , Wang Titi
Published: October 2012

Enzymatic biosensors are often used to detect trace levels of some specific substance. An alternative methodology is applied for enzymatic assays, in which the electrocatalytic kinetic behavior of enzymes is monitored by measuring the faradaic current for a variety of substrate and inhibitor concentrations. Here we examine a steady-state and pre-steady-state reduction of H2O2 on the horseradish peroxidase electrode. The results indicate the substrate-concentration dependence of the steady-state current strictly obeys Michaelis-Menten kinetics rules; in other cases there is ambiguity, whereby he inhibitor-concentration dependence of the steady-state current has a discontinuity under moderate concentration conditions. For pre-steady-state phases, both catalysis and inhibition show an abrupt change of the output current. These anomalous phenomena are universal and there might be an underlying biochemical or electrochemical rationale.
Providing Self-Healing Ability for Wireless Sensor Node by Using Reconfigurable Hardware
Authors: Yuan Shenfang , Qiu Lei , Gao Shang , Tong Yao , Yang Weiwei
Published: October 2012

Wireless sensor networks (WSNs) have received tremendous attention over the past ten years. In engineering applications of WSNs, a number of sensor nodes are usually spread across some specific geographical area. Some of these nodes have to work in harsh environments. Dependability of the Wireless Sensor Network (WSN) is very important for its successful applications in the engineering area. In ordinary research, when a node has a failure, it is usually discarded and the network is reorganized to ensure the normal operation of the WSN. Using appropriate WSN re-organization methods, though the sensor networks can be reorganized, this causes additional maintenance costs and sometimes still decreases the function of the networks. In those situations where the sensor networks cannot be reorganized, the performance of the whole WSN will surely be degraded. In order to ensure the reliable and low cost operation of WSNs, a method to develop a wireless sensor node with self-healing ability based on reconfigurable hardware is proposed in this paper. Two self-healing WSN node realization paradigms based on reconfigurable hardware are presented, including a redundancy-based self-healing paradigm and a whole FPAA/FPGA based self-healing paradigm. The nodes designed with the self-healing ability can dynamically change their node configurations to repair the nodes’ hardware failures. To demonstrate these two paradigms, a strain sensor node is adopted as an illustration to show the concepts. Two strain WSN sensor nodes with self-healing ability are developed respectively according to the proposed self-healing paradigms. Evaluation experiments on self-healing ability and power consumption are performed. Experimental results show that the developed nodes can self-diagnose the failures and recover to a normal state automatically. The research presented can improve the robustness of WSNs and reduce the maintenance cost of WSNs in engineering applications.