bluuebunny/crossref_metadata_2025 huggingface dataset:
An Evaluation of the Literature on Integrated Sugarcane Production Systems
Authors: Bezuidenhout C.N. , Baier T.J.A.
Published: April 2011

Logistically, the sugarcane supply and processing chain up to the raw sugar stage is driven by biophysical push factors rather than market-related pull factors. Sugarcane systems do not align fully with lean and agile supply chain thinking. This paper synthesizes a range of issues governing the sugarcane supply and processing chain. This synthesis was achieved through scientometrical analyses of a worldwide collection of publications. The aim was to develop a conceptual sugarcane supply chain framework and to evaluate research trends, knowledge gaps and limitations. Key system properties were identified from the literature and co-word analyses were carried out. Several exploratory exercises were executed on the co-occurrence matrix using the PAJEK software. The literature generally focuses on material handling issues in isolation from other factors, such as collaboration, information sharing and innovation. Impacts of harvesting on downstream processes remain a pertinent research topic. Also, emerging alternative products impose new complexities on the supply chain. Conflicting grower–miller relationships still suppress collaboration in most parts of the world. Mathematical modelling is a popular technique to produce innovative system improvements. Models, however, tend towards finding long-term solutions and lack the development of operational short-term applications. Production risk is an area that needs more focus. Researchers need to consider the supply chain more holistically, not only with respect to different dimensions in the chain (such as profitability, innovation, information and collaboration), but also within the local commercial socioeconomic regime.
Estimating Eco-Compensation Requirements for Forest Ecosystem Conservation
Authors: Fen Li , Wenhua Li , Lin Zhen , Heqing Huang , Yunjie Wei , Naomi Inoue
Published: April 2011

This study provides an estimation of the eco-compensation requirements for forest ecosystem conservation in Hainan province of China using the ecological location quotient (ELQ). It determines that the ecosystem services provided by the forest ecosystem need to be classified into predominant, secondary and potential types. Consequently, the appropriate levels of payment are calculated using the ecological valuation coefficient (EVC) method. The mechanisms and standards of payment are then determined for the corresponding stages in the context of the eco-compensation concept. In this way, guidelines are provided for practising eco-compensation, not only in Hainan province but also in the other parts of China.
Agroforestry Systems as Land Use Alternatives in Germany?
Authors: Reeg Tatjana
Published: April 2011

The growing and utilization of woody plants on agricultural land used to be a part of traditional land use systems in many countries, including Germany. In the tropics, ‘modern’ agroforestry systems have been propagated since the 1970s, and countries of the temperate zones have also been researching and testing them. In Germany, the question of (re)introducing agroforestry systems has been raised only in recent years. As yet, few plots have been established. How appealing is this kind of land use to German farmers? The current situation in Germany is analysed and compared with the reasons for the implementation of agroforestry systems elsewhere.
Smallholder Dairy Farming in Tanzania
Authors: Swai Emmanuel S. , Karimuribo Esron D.
Published: April 2011

Smallholder dairy farming is growing in Tanzania at a rate of 6% per year, with an estimated 190,000 registered farmers. Despite the fact that smallholder dairy farming is widespread in different parts of Tanzania where the climate is appropriate, the supply of milk and milk products in these regions has not kept pace with the rapid increase in the human population. Productivity in existing smallholder dairy herds is constrained by the small size of farms and their distance from markets, animal health and reproductive problems and lack of good-quality animal feeds in sufficient quantities. Other constraints include lack of infrastructure for input and output markets, unfavourable regulatory and taxation policies, poor flow of information, restricted access to credit and limited supply of dairy cattle. Nevertheless, the sector is acknowledged for its contribution to household food security, employment opportunities and as a regular source of income for farmers. Dairy production integrated into rural, peri-urban and urban smallholder mixed farming systems may increase and stabilize farm incomes and act as a catalyst for agricultural development and improved standards of living. The authors conclude that smallholder dairy production is an important undertaking and, if adequately supported by appropriate policies and adaptive research technologies, it may contribute significantly towards the household economy, self-sufficiency in milk and national gross domestic product.
Modelling the Economic Impact of International Tourism on the Chinese Economy: A CGE Analysis of the Beijing 2008 Olympics
Authors: Li Shina , Blake Adam , Cooper Chris
Published: April 2011

International inbound tourism to China has grown phenomenally since 1980 and the hosting of the Olympics in 2008 was an important milestone. This paper takes the first step in applying computable general equilibrium (CGE) modelling to forecasting the economic contribution of tourism generated by the Beijing Olympics. CGE modelling has been widely applied to different tourism issues in many countries. In China, it has been used in fields such as taxation and international trade. However, economic impact studies on China's tourism using CGE modelling have not been found. The paper includes two types of estimations: ex ante and ex post. The ex ante estimation was conducted before the Beijing Olympics and thus predicted the impact of international tourism based on historical data, such as previous literature and historical statistics. The ex post estimation was conducted several months after the Beijing Olympics and the estimation was based on up-to-date statistics published by the China National Tourism Administration. The economic impact generated from the two types of estimations is compared. It was found that, while the economic impact of international tourism was predicted to be positive in the ex ante estimation, this impact was analysed as negative in the ex post estimation.
An Empirical Study of the Influences of Recreational Park Visitation: The Case of US National Park Service Sites
Authors: McIntosh Christopher R. , Wilmot Neil
Published: April 2011

The authors examine which variables influence recreational visitation at 353 US National Park Service (NPS) sites. The paper provides evidence that variables other than lagged visitation, including various site designators, various regional dummies, lagged RDPI (inferior), alternative sites (complementary effect), the regional 9/11 terrorist attacks variable and the regional terrorism threat level variable (increase in threat level decreases visitation) are statistically and economically significant. Generally, the statistical significance and magnitude of the variable's influence increases as site visitation increases. These results should be of interest to planners and policy makers in general, and specifically to NPS planners in charge of a US$2.2 billion budget.
Yield Management and Airline Strategic Groups
Authors: Vila Natalia , Córcoles Manuel
Published: April 2011

A new strategic group of companies has appeared in Europe. This group, low-cost airlines, differs markedly from the traditional flagship companies. Focusing on a dynamic approach, the study discussed in this paper was developed to determine whether companies in different strategic groups adopted different price setting methods depending on which group they belonged to. The study is based on price information recorded at 11 different time periods for 12 airlines.
An Empirical Approach to Coastal Leisure Shipping in Greece and an Assessment of its Economic Contribution
Authors: Diakomihalis Mihail N. , Lagos Dimitris G.
Published: April 2011

This paper analyses coastal leisure shipping activity in Greece and estimates its economic contribution to the national economy. Even though the activity is encompassed by the shipping transport sector and is supervised by the Ministry of Merchant Marine, its product appears to be offered exclusively to tourists. The magnitude of the economic contribution of coastal leisure shipping to the Greek economy is assessed through the implementation of the Tourism Satellite Account (TSA). Although the contribution of coastal leisure shipping to the national economy is not very substantial, it is significant to the local economies of the insular and coastal regions. The tourist ‘day ships’ constitute a dependable means of connecting the small islands with the larger islands and the ports of continental Greece. The role of the daily sea tours for the inhabitants of small islands is purely that of a means of transportation, since for most of them the tourist boats are an alternative, or sometimes the only means of connection with the rest of the world.
Determinants of the Competitive Advantage of Residential Tourism Destinations in Spain
Authors: Ribes José Francisco Perles , Rodríguez Ana Ramón , Jiménez Martín Sevilla
Published: April 2011

This paper focuses on an analysis of the tourism competitiveness of residential destinations on the Spanish coast, applying Porter's competitive advantage theory. This analysis is conducted with a hypothesis test using a structural equation model based on Porter's competitive diamond. The paper shows that by analysing a range of variables, it is possible to develop attributes related to competitiveness which constitute Porter's diamond model, confirming that this theory is appropriate for explaining the tourism development processes in residential tourism destinations on the Spanish coast. The results show how the competitive difference between destinations in such a specific geographical area is based mainly on small details belonging to the advanced factors of the competitive advantage theory. Finally, there is cause for concern in the fact that the supporting and related sectors determinant has a negative influence on competitiveness.
Research Note: The Economic Impact of Opening a Gaming Venue in Australia
Authors: Lee Timothy Jeonglyeol
Published: April 2011

Research shows that opening a large gaming venue has economic impacts. This paper evaluates these impacts from the perspectives of the government, industry and the community. Though the effects are interrelated, the direct impact for each of these stakeholders is unique. For the government, direct taxation, tourism and investment are discussed, with a focus on the immediate effect on infrastructure. For industry, revenue generation, the multiplier effect, leakage, cannibalization and the trend of strategic cross-industry alliance are examined. For the community, average household disposable income, employment rate, direct competition, land speculation and the impact on standard of living are analysed.
Pricing the Time and Location of a Stay at a Hotel or Apartment
Authors: Juaneda Catalina , Raya Josep Maria , Sastre Francesc
Published: April 2011

This paper presents a comparative study of the price component of the physical characteristics and the location of apartments and hotels in order to compare their effect on the final price of both types of accommodation. In addition the authors carry out a comparative study of the price component of the point in time at which the stay was offered. For the price component of the actual place, substantial variability can be observed in the case of hotels, whereas little variability can be observed in the case of apartments. When seasonality is compared, slightly lower seasonality can be observed for hotels in relation to apartments throughout the period under study, and higher seasonality observed in the case of Spanish resorts (particularly the Balearic Islands) in comparison with French ones.
A New Species of the Genus Pholcus Walckenaer, 1805 (Araneae, Pholcidae) from Hainan Island, China
Authors: Peng Yan-Qiu , Zhang Feng
Published: April 2011

A new species belonging to the genus Pholcus from Hainan Island, China, is described and illustrated, and under the name Pholcus acerosus sp. nov.
Genetic Polymorphisms as Risk Stratification Tool in Primary Preventive ICD Therapy
Authors: Laszlo Roman , Busch Mathias C. , Schreieck Jüergen
Published: April 2011

More and more implantable cardioverter-defibrillators (ICDs) are implanted as primary prevention of sudden cardiac death (SCD). However, major problem in practice is to identify high-risk patients for SCD. Different methods for noninvasive risk stratification do not have a sufficient positive or negative predictive value. Since current approaches lead to implantation of ICDs in a large number of patients who will never suffer an arrhythmic event and simultaneously patients still die of SCD who currently did not seem eligible for primary preventive ICD implantation, there is a need for additional tools for risk stratification.
Epidemiological studies point to a hereditary risk of SCD. Different susceptibility of each person concerning arrhythmogenic events might be explained by genetic polymorphisms. By obtaining an individual “pattern” of polymorphisms of genes encoding for proteins which are important in arrhythmogenesis in one patient, risk stratification in primary prevention of SCD might by improved.
Unsteady Heat Transfer from an Equilateral Triangular Cylinder in the Unconfined Flow Regime
Authors: Dhiman Amit , Shyam Radhe
Published: April 2011

Effects of Reynolds number on the heat transfer characteristics of a long (heated) equilateral triangular cylinder are investigated for the range of conditions Re = 50–150 (in the steps of 10) and Prandtl number = 0.71 (air) in the unconfined unsteady cross-flow regime. In order to simulate the present situation, the computational grid is created by using commercial grid generator GAMBIT and the numerical computations are carried out by using FLUENT (6.3). The SIMPLE method is used to solve continuity, Navier-Stokes and energy equations along with the appropriate boundary conditions. The second order upwind scheme is used to discretize the convective terms, while the central difference scheme is used to discretize the diffusive terms in the governing equations. The present results are in an excellent agreement with the literature values. The temperature isotherms and temporal history of Nusselt number are presented in detail. The local as well as time-averaged Nusselt numbers are calculated. The time-averaged Nusselt number increases with increasing Reynolds number for the fixed value of the Prandtl number. Finally, the present numerical results are used to develop the simple heat transfer correlation for the range of conditions covered here.
Boron, Elemental
Authors: Jansen Linda H.
Published: April 2011

Boron is unique in that it is the only nonmetal in group 13(IIIA) of the Periodic Table. Boron has more similarity to carbon and silicon than to to the elements in Group 13. A widespread boron mineral is tourmaline, a complex borosilicate. However, the most common ores are alkali and alkaline‐earth borates. Borax is the most important ore of boron. Boron is produced by the reduction of boric acid with magnesium (the Moissan process). Boron is a trace element that is essential to human health and behavior There have been no reports of toxicity in humans. Elemental boron is used in many diverse industries including metallurgy, ceramics, glass, fibers, energy as fuels and in batteries, agriculture, pyrotechnics, and radiation shielding. Boron alloys containing aluminum and magnesium have been found to be of a hardness nearly equal to that of diamond.
Calcium and Calcium Alloys
Authors: Vrana Lisa M.
Published: April 2011

Calcium, a member of Group 2 (IIA) of the Periodic Table between magnesium and strontium, is classified, together with barium and strontium, as an alkaline‐earth metal.The word calcium is derived from calx, the Latin word for lime. Pure calcium is a bright silvery white metal. Under normal atmospheric conditions. freshly exposed surfaces of calcium quickly become covered with an oxide layer. Calcium is manufactured by electrolysis or the aluminothermal method. Because of its extreme chemical reactivity, calcium metal must be carefully packaged for shipment and storage. Calcium metal can produce damaging effects if inhaled. It is also the most abundant metal in the human body and is a key constituent of bones and teeth and has key metabolic functions. Calcium is used for the improvement of steel, in battery manufacture, and as a reducing agent. Alloys of calcium with silicon are used in ferrous metallurgy.
Corrosion and Corrosion Control
Authors: Policastro Steven , Martin Farrel , Natishan Paul , Moran Pat
Published: April 2011

This article discusses the various types of corrosion and the fundamental mechanisms responsible for corrosion. The importance of electrochemical reactions in causing and controlling corrosion phenomena is emphasized. The influence of environmental factors and metallurgical variables is reviewed and the predominant corrosion modes for technologically significant metal and alloy systems are discussed. The various methods of corrosion prevention such as cathodic protection, coatings, and inhibitors are also described. Throughout the article, references to additional information are included.
Wood‐Based Composites and Laminates
Authors: Lehmann William F.
Published: April 2011

Wood is one of the oldest construction materials and extremely valuable today. It is important more than ever to manage forests as sustainable and renewable resources. In the conversion of timber to lumber, only about one‐half of the log becomes lumber. The rest becomes waste in the form of bark, slabs ,edgings. shavings. etc. These residues remained largely unused until recently. Today virtually the entire wood stem is converted to wood products. Recycling has also added to the yield. Currently these wastes and residues are used to create useful composite materials which have become an important segment of the entire system. The composites can be used in a myriad products, such as flooring, roofing, construction panels, furniture, etc. The conventional wood‐based composites are plywood, oriented strandboard, fiberboard, and particleboard. Their manufacture and uses are detailed. Glulam timber and structural composite lumber are included in the discussion. Natural and synthetic adhesives are a major part of laminate production. An important consideration in the production of wood laminates is the emission of formaldehyde from manufactured products. Green building certifications also address the formaldehyde issue. The new U.S. law on standards for formaldehyde emissions will play a role in world markets.
Biocatalytic Concurrent Processes
Authors: Bisogno Fabricio R. , Lavandera Iván , Gotor Vicente
Published: April 2011

In line with the new governmental initiatives and industrial demands related to the “Green Chemistry” principles, the design of sustainable processes according to them and applicable at industrial scale is highly desirable. One of the possible strategies is to employ multistep chemical synthesis with efficient catalytic reactions that improve the “atom economy” of the process. In this context, concurrent methodologies in which multiple catalysts operate simultaneously in “one pot”, circumventing the time‐consuming and yield‐reducing isolation and purification of intermediates are gaining momentum nowadays. Thus, elegant examples of tandem or cascade methodologies are being described in order to perform stereoselective processes, such as deracemization protocols of hydroxy derivatives, or the simultaneous coupling of selective reactions to achieve, e.g., interconnected double kinetic resolutions or a desymmetrization plus a kinetic resolution. Many examples deal with oxidoreductases taking advantage of efficient cofactor recycling systems, but other works have shown that enzymes like hydrolases, transferases or lyases can also be employed in these processes with high efficiency. Furthermore, novel cooperative protocols in which an organo‐ or metal‐catalyst is combined with a biocatalyst are opening the scope and possibilities of implementing biocatalysts in integrated multistep synthetic pathways. Some of these examples are discussed focusing on the concept behind, as well as on their possible synthetic applicability.
Data Interpretation and Correlation
Authors: Buzzi‐Ferraris Guido , Manenti Flavio
Published: April 2011

Data interpretation and correlation lie at the very foundations of all technological fields and scientific areas that involve experimentation and measures. This entry explores the fundamental contents of data analysis, such as data samples, linear regressions, and nonlinear regressions. Its main aim is to describe the most important methods and techniques designed to tackle problems that can significantly affect data interpretation and result in misleading estimates. The problems involved in outlier detection are discussed specifically, and robust identification methods are explained and compared under a variety of relevant and widespread headings, such as masking and swamping effects, heteroscedasticity condition, collinearity, and so on.
Flooring Materials
Authors: Schmidle Claude J. , Conger Robert P. , Boranian Armen
Published: April 2011

Flooring materials containing polymers include resilient sheet goods and tile, prefinished and acrylic impregnated hardwood, and seamless, monolithic, and troweled surface coatings. The principle area of use is resilient flooring, the largest portion of which is poly(vinyl chloride) (PVC) homopolymer or copolymers containing vinyl acetate. Significant amounts of acrylics, polyurethanes, and butadiene‐styrene resins are also used.
Foundry Resins
Authors: Langer Heimo J. , Dunnavant William R.
Published: April 2011

The foundry industry uses several procedures for casting metal parts: permanent mold casting, centrifugal casting, and sand casting. Permanent molds are made of metal, graphite, or a ceramic. In sand casting, molds and cores are used. Cores are required for hollow castings and must be removed after the metal has solidified. Cores are used in both sand and permanent molds.

Binders were developed to strengthen the cores, which are the most fragile part of a mold assembly. Although the use of binders in mold production is increasing, most sand casting employs so‐called green sand molds, which are made of sand, clay, and additives. Inorganic binders such as clay, cement, or sodium silicate are inexpensive materials that have long been used in the production of foundry molds and cores. This article is limited to synthetic organic resin‐based binders, which, because of their versatility and performance, have resulted in significant labor and energy savings and higher foundry productivity.
Organoselenium and organotellurium compounds: Toxicology and pharmacology
Authors: Nogueira Cristina W. , Rocha João B. T.
Published: April 2011

In the last three decades, the interest in the field of synthesis and reactivity of organoselenium and organotellurium compounds has increased; particularly, in view of the observations that they can exhibit important biological activities. The data presented in this chapter clearly indicate the potential pharmacological and therapeutic uses of organoselenium and organotellurium compounds. Indeed, these classes of molecules exhibit a variety of interesting biological effects, namely antioxidant properties, which can account for theirin vitroandin vivobeneficial effects in a wide range of models of different human pathologies. We can conclude that the future of “medicinal chemistry“ of organoselenium and organotellurium compounds will depend on the rational development of new molecules, which can be guided by chemical and biological approaches. Moreover, the structure‐activity relationship for a given class of organoselenium or organotellurium compounds should be used as a toll for screening molecules with high probability of exhibiting low toxicity and high pharmacological activity in mammals.
Electrochemistry of Organic Selenium and Tellurium Compounds
Authors: Jaworski Jan S.
Published: April 2011

Electrochemical synthesis of organic selenium and tellurium compounds as well as different mechanisms of their anodic and cathodic reactions were reviewed. The first part includes the review of the direct synthesis of the title compounds from the elemental selenium and tellurium, the synthesis by anodic reactions using mainly the generation of arylselenium or tellurium cations and the cathodic reduction based on the generation of organoselenium and tellurium anions. These synthetic applications, more interesting for the wider group of organic chemists, are discussed in more detail. Examples of the anodic functionalization (such as acetoxylation or fluorination) leading to new organic chalcogen compounds are also given.

The detailed discussion of the anodic behavior of the title compounds is divided into separate parts, each of them devoted to the different class of compounds. They include first of all diaryl, dialkyl and alkylarylselenides and tellurides, most widely investigated for many years, and next diaryl and dialkyl diselenides. However, anodic reactions of some typical heterocyclic selenides and tellurides are also briefly reviewed. Some electrode reactions in which the title compounds play only the role of intermediates are mentioned as well. Finally, electroreduction mechanisms of organoselenium and tellurium compounds are discussed.
Civic Building: Forte, Gimenes & Marcondes Ferraz Arquitetos (FGMF), São Paulo
Authors:   FGMF
Published: April 2011

São Paulo‐based practice Forte, Gimenes & Marcondes Ferraz (FGMF) places particular importance on developing relationships between architecture, its environment and the user. This is apparent in its two projects featured here: the FDE Public School at Várzea Paulista, for which the firm created concrete brise‐soleils ; and the Edifício Projeto Viver, a community building at Morumbi, which it retained as a gateway for the favela it serves. Copyright © 2011 John Wiley & Sons, Ltd.
Universities as Mediators: The Cases of Buenos Aires, Lima, Mexico and São Paulo
Authors: Leguía Mariana
Published: April 2011

Stepping into the vacuum left by state and public services, architecture departments in universities have become key players in the development of their regions. As guest‐editor of this issue, Mariana Leguía explains how this has led to a new teaching and research model, where universities act as mediators between government, private investors, NGOs and local communities. She looks at the activities of institutions in Argentina, Peru, Mexico and Brazil that are proactive in this field. Copyright © 2011 John Wiley & Sons, Ltd.
In Situ Carbon Nanotube Formation in Templated Pores of Polymer‐Derived Ceramics
Authors: Terry Craig S. , Scheffler Franziska , Torrey Jessica D. , Bordia Rajendra K. , Scheffler Michael
Published: April 2011

Multi‐walled carbon nanotubes (MWCNTs) have been formed in situ in porous, polymer derived ceramics, using polystyrene (PS) microbeads as pore formers. The microbeads were coated with nickel acetate, as a transition metal catalyst precursor, and then introduced into the preceramic polymer methylphenylpolysiloxane (PMPS). The PMPS served as a precursor for the ceramic matrix and as carbon source for CNT formation. The PS microbead burnout was observed between 200 and 400 °C, leaving behind nickel nanoparticles at the surface of the templated pore walls. Thermal conversion of the precursor to ceramic was carried out in the temperature range between 500 and 1 200 °C. MWCNTs were formed in the templated pores during the pyrolysis step by converting the carbon from the decomposition of PMPS. The oxidation resistance of these composites has been studied and an interesting catalytic oxidation phenomenon was observed that may be quite important for the oxidation of carbon nanotubes.
Magnetic Nanoparticles: A Versatile Method for the Reductive, One‐Pot Synthesis of Bare, Hydrophilic and Hydrophobic Magnetite Nanoparticles (Adv. Funct. Mater. 8/2011)
Authors: Yathindranath Vinith , Rebbouh Leila , Moore David F. , Miller Donald W. , van Lierop Johan , Hegmann Torsten
Published: April 2011

A biocompatible, reliable, and particularly versatile synthesis of magnetic iron oxide nanoparticles (IONPs) is presented that uses iron(III) acetylacetonate Fe(acac)3 as an iron precursor and sodium borohydride as a reducing agent. Both the reaction temperature and the concentration of the reducing agent have considerable effects on the IONP size. These dependencies can be used to prepare IONPs ranging in size from 5 to 8 nm, as determined by transmission electron microscopy (TEM). Synthesis at room temperature or with higher sodium borohydride concentrations always resulted in smaller particle sizes. Powder X‐ray diffraction patterns show the presence of an iron oxide phase with a cubic unit cell and allow for the determination of the lattice parameters and average crystallite sizes for all synthesized IONPs. Transmission Mössbauer spectroscopy shows that the as‐synthesized IONPs are pure magnetite (Fe3O4) and is further used to elucidate the reaction pathway by analyzing iron intermediates formed prior to nanoparticle formation and precipitation. TEM and high‐resolution TEM reveal quasi‐spherical shapes and lattice fringes for most IONPs. With only minor modifications of the synthesis procedure, this versatile, one‐pot synthesis is proven to be suitable for the production of bare (uncoated) IONPs, IONPs with hydrophilic poly(ethylene glycol), L‐arginine, and L‐glutamic acid coatings, as well as IONPs with hydrophobic coatings such as oleic acid. All coated IONPs were characterized by FT‐IR spectroscopy. In addition, the bare IONPs could easily be modified post‐synthesis with a suitable capping agent using ultrasonication. To verify the biocompatibility of the IONPs, in vitro cytotoxicity studies were carried out on bare IONPs with intestinal (Caco2) and liver epithelial (HepG2) cell cultures using an 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. Phase contrast microscopy after hematoxylin‐eosin staining showed the intact morphology of the Caco2 and HepG2 cells treated with IONPs.
Surface‐Plasmon Assisted Energy Conversion in Dye‐Sensitized Solar Cells
Authors: Ding Bo , Lee Bong Jae , Yang Mengjin , Jung Hyun Suk , Lee Jung‐Kun
Published: April 2011

In this study, the effect of plasmonic core‐shell structures, consisting of dielectric cores and metallic nanoshells, on energy conversion in dye‐sensitized solar cells (DSSCs) is investigated. The structure of the core‐shell particles is controlled to couple with visible light so that the visible component of the solar spectrum is amplified near the core‐shell particles. In core‐shell particle – TiO2 nanoparticle films, the local field intensity and light pathways are increased due to the surface plasmons and light scattering. This, in turn, enlarges the optical cross‐section of dye sensitizers coated onto the mixed films. When 22 vol% of core‐shell particles are added to a 5 μm thick TiO2 film, the energy conversion efficiency of DSSCs increases from 2.7% to 4.0%, in spite of a more than 20% decrease in the amount of dyes adsorbed on the composite films. The correlation between core‐shell particle content and energy conversion efficiency in DSSCs is explained by the balance among near‐field effects, light scattering efficiency, and surface area in the composite films.
Polyhydrated ionogen enhances postoperative sinonasal ciliated remucosalization
Authors: DePoortere David , Kofonow Jennifer M. , Chiu Alexander G. , Cohen Noam A.
Published: April 2011

Background

Mucosalization of the sinonasal cavity following surgery is critical for successful outcomes. Recently a novel anti‐protease compound, polyhydrated‐ionogen (PHI) with Mg2+/Br−, demonstrated improved dermal wound healing. We set out to investigate the effect of PHI Mg2+/Br− on sinus remucosalization following surgery.

Methods

A total of 24 rabbits underwent bilateral medial‐wall maxillary mucosal stripping followed by placement of an indwelling irrigation catheter. In a randomized fashion 1 side received 3 cc normal saline (NS) daily, while the contralateral side received PHI Mg2+/Br−. Following a 14‐day therapeutic trial, remucosalization was assessed by hematoxylin and eosin (H&E) staining and immunohistochemistry for β‐tubulin, a marker of cilia. A semiquantitative grading of ciliated remucosalization was applied with a chi‐square test used to compare distributions for each treatment.

Results

H&E staining comparison demonstrated NS treated sinuses (n = 24) had substantial bare areas with predominant ciliation scores under 30%. The PHI Mg2+/Br−‐treated group (n = 24) achieved a statistically significant improvement in reciliation (>60%) when compared with NS (p < 0.01). These results were confirmed with Type IV β‐tubulin staining (p < 0.01).

Conclusion

Poor postsurgical sinonasal mucosa healing results in adverse clinical outcomes. In a rabbit model of sinonasal mucosal healing, daily irrigation for 14 days with PHI Mg2+/Br−‐enhanced ciliated remucosalization compared to saline. © 2011 ARS‐AAOA, LLC.
Oral corticosteroid therapy in chronic rhinosinusitis without polyposis: a systematic review
Authors: Lal Devyani , Hwang Peter H.
Published: April 2011

Background

Recognition of inflammation in the pathophysiology of chronic rhinosinusitis (CRS) has caused corticosteroid therapy in CRS to gain favor. A systematic evaluation of oral steroid use in CRS without nasal polyps (CRSsNP) has not been previously conducted. The objective of the study was to assess evidence on oral steroid therapy in CRSsNP, via a systematic literature review.

Methods

Ovid and PubMed databases were searched for studies on oral steroid therapy in CRSsNP. Manuscripts were reviewed and graded by evidence‐based medicine (EBM) level.

Results

A total of 33 studies met inclusion criteria; 30 on CRSsNP and 3 on allergic fungal sinusitis (AFS). CRSsNP studies did not include any randomized controlled trial (RCT) or any clinical study employing systemic corticosteroids alone. They included 20 reviews/expert opinions (Level 5) with differing recommendations, and 4 treatment guidelines (Level 4) with weak recommendations on use. Three studies, 2 retrospective (Level 4) and 1 prospective study (Level 3), used oral steroids in combination with antibiotics and nasal steroids. The multidrug regimen improved symptoms, radiologic findings, short‐term relapses, nasal endoscopy, and cytokine pattern expression. An experimental study (Level 5) found oral steroids to reverse sinonasal tissue inflammation. Two studies in animal models (Level 5) found no benefit of adding systemic steroids to antibiotics. Three clinical AFS studies, 1 RCT (Level 1) and 2 prospective (Level 3), found oral steroids to benefit postoperative recurrence, endoscopy or computed tomography (CT).

Conclusion

No study has employed systemic corticosteroids alone in treating CRSsNP. Evidence supporting oral steroid therapy in CRSsNP is mostly Level 4 or 5; there is lack of any RCT to support use. © 2011 ARS‐AAOA, LLC.
Periostin and osteopontin are overexpressed in chronically inflamed sinuses
Authors: Daines Steven Marc , Wang Yong , Orlandi Richard R.
Published: April 2011

Objective

In chronic rhinosinusitis (CRS), the inflammation leads to a proliferative response in the extracellular matrix (ECM). Periostin and osteopontin are 2 ECM proteins which have received attention for their roles in tissue remodeling in inflammatory diseases of the upper and lower airways. Transforming growth factor beta‐1 (TGFβ1) is an inflammatory cytokine that has been implicated in fibrotic conditions affecting virtually every organ. In this study we seek to evaluate the differential expression of periostin, osteopontin, and TGFβ1 in the ethmoid sinus and nasal floor of patients with CRS. Furthermore, we seek to determine if a correlation exists between their differential expression in the nose and sinuses of patients with CRS.

Methods

Biopsies from ethmoid sinus and nasal floor mucosa were taken from 15 patients undergoing functional endoscopic sinus surgery (FESS) for CRS. Complementary DNA (cDNA) microarray analysis demonstrated upregulation of periostin and osteopontin in the ethmoid sinus samples. Quantitative real‐time polymerase chain reaction (RT‐PCR) was performed for periostin, osteopontin, and TGFβ1. Statistical analysis was undertaken to examine correlations between the 3 genes of interest.

Results

RT‐PCR confirmed that periostin and osteopontin were overexpressed in the ethmoid samples compared to the nasal floor. The differential expression of both periostin and osteopontin showed significant correlation with TGFβ1.

Conclusion

Periostin and osteopontin appear to be involved in ECM remodeling seen in CRS. TGFβ1 may be an upstream inducer of CRS‐related changes in ethmoid sinus mucosa. © 2011 ARS‐AAOA, LLC.
The efficacy of hemostatic techniques in the sheep model of carotid artery injury
Authors: Valentine Rowan , Boase Sam , Jervis‐Bardy Josh , Dones Cabral Jay‐Dee , Robinson Simon , Wormald Peter‐John
Published: April 2011

Background

The most dramatic complication in endonasal surgery is inadvertent injury to the internal carotid artery (ICA) with massive bleeding. Nasal packing is the favored technique for control; however, this often causes complete carotid occlusion or carotid stenosis, contributing to the morbidity and mortality of the patient. The aim of this study is to compare the efficacy of endoscopically applied hemostatic techniques that maintain vascular flow in an animal model of carotid artery injury.

Methods

A total of 20 sheep underwent ICA dissection/isolation followed by the placement of the artery within a modified “sinus model otorhino neuro trainer” (SIMONT) model. A standardized 4‐mm carotid artery injury was created endoscopically. Randomization of sheep to receive 1 of 5 hemostatic techniques was performed (Floseal, oxidized regenerated cellulose, Chitosan gel, muscle patch, or the U‐Clip anastomotic device). Specific outcome measures were time to hemostasis, duration of time mean arterial pressure (MAP) was >55 mmHg, blood loss, and survival time.

Results

Muscle patch hemostasis and the U‐Clip anastomotic device were significantly more effective at achieving primary hemostasis rapidly, reducing total blood loss, and increasing survival time and time MAP was >55 mmHg more than Floseal, oxidized regenerated cellulose, and Chitosan gel (p < 0.05). Additionally, all muscle patch–treated and U‐Clip device–treated sheep achieved primary hemostasis and reached the endpoint of observation, while maintaining vascular patency. Floseal and oxidized regenerated cellulose failed to achieve hemostasis in any animal, with all animals exsanguinating prematurely.

Conclusion

In the sheep model of endoscopic ICA injury, the muscle patch and U‐Clip anastomotic device significantly improved survival, reduced blood loss, and achieved primary hemostasis while maintaining vascular patency. © 2011 ARS‐AAOA, LLC.
Die Chemie und der Wurm: Caenorhabditis elegans als Plattform für das Zusammenführen von chemischer und biologischer Forschung
Authors: Hulme S. Elizabeth , Whitesides George M.
Published: April 2011

Dieser Aufsatz diskutiert die Nützlichkeit des Wurms Caenorhabditis elegans als Modellorganismus für Chemiker, die an der Untersuchung lebender Systeme interessiert sind. C. elegans, ein 1 mm langer Rundwurm, ist ein beliebter Modellorganismus in nahezu allen Gebieten der modernen Biologie. Der Wurm hat zahlreiche Eigenschaften, die ihn für die Biologie attraktiv machen: Er ist klein (<1000 Zellen), transparent und genetisch leicht zu manipulieren. Trotz seiner Schlichtheit weist der Wurm komplexe Phänotypen auf, die mit seiner Mehrzelligkeit zusammenhängen: Er hat differenzierte Zelltypen und Organe, er altert und hat eine wohldefinierte Lebenserwartung, er kann lernen und besitzt ein Erinnerungsvermögen. Der Aufsatz will verdeutlichen, dass diese Mischung aus Einfachheit und Komplexität den Wurm zu einem besonders nützlichen Werkzeug macht, um die Beziehungen zwischen Phänomenen auf molekularer Ebene und der Ebene des Gesamtorganismus zu erforschen (Altern, Verhalten, Kognition, Anfälligkeit für Krankheiten). Es werden vornehmlich solche Forschungsarbeiten vorgestellt, die chemisch relevant sind. Außerdem werden Instrumente und Arbeitstechniken – biologischer, chemischer und physikalischer Natur – vorgestellt, die uns zur Erforschung des Wurms zur Verfügung stehen.
A simple non‐minimum phase zero's predictor for open‐loop unstable processes
Authors: Nasution Anggi Arifin , Jeng Jyh‐Cheng , Huang Hsiao‐Ping
Published: April 2011

This paper proposes a Smith‐type predictive compensator for open‐loop unstable processes that have non‐minimum phase zero. It has been well‐recognized that this type of predictor reported in the literature encounters internally unstable problem when applied to an open‐loop unstable process. To satisfy the internal stability, the proposed predictor utilizes the partial internal model principle. And, the controller is designed by internal mode control principal to have H2 optimal performance. Simulation examples are presented to illustrate that the proposed control scheme can give satisfactory performance and robustness. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
An Adamantane‐Based Building Block for DNA Networks
Authors: Pathak Richa , Marx Andreas
Published: April 2011

DNA governs the storage and transfer of genetic information through generations in all living systems with the exception of some viruses. Its physicochemical nature and the Watson–Crick base pairing properties allow molecular constructions at nanometer length, thereby enabling the design of desired structural motifs, which can self‐assemble to form large supramolecular arrays and scaffolds. The tailor‐made DNAs have been an interesting material for such designed nanoscale constructions. However, the synthesis of specific structures with a desired molecular function is still in its infancy and therefore has to be further explored. To add a new dimension to this approach, we have synthesized a rigid three‐way branched adamantane motif, which is capable of forming highly stable DNA networks. The moiety generated could serve as a useful building block for DNA‐based nanoconstructions.
Growing muscle has different sarcolemmal properties from adult muscle: A proposal with scientific and clinical implications
Authors: Grounds Miranda D. , Shavlakadze Thea
Published: April 2011

We hypothesise that the sarcolemma of an actively growing myofibre has different properties to the sarcolemma of a mature adult myofibre. Such fundamentally different properties have clinical consequences for the onset, and potential therapeutic targets, of various skeletal muscle diseases that first manifest either during childhood (e.g. Duchenne muscular dystrophy, DMD) or after cessation of the main growth phase (e.g. dysferlinopathies). These characteristics are also relevant to the selection of both tissue culture and in vivo models employed to study such myopathies and the molecular regulation of adult myofibres. During growth, multinucleated myofibres increase enormously in size and volume with dramatic increases in length (up to ∼600 mm). This is in striking contrast with most mononucleated cells such as fibroblasts, that remain at a relatively small size (∼10–20 µm diameter). The consequences of a dynamic, expanding sarcolemma during growth, compared with that of an adult myofibre of a fixed length, are discussed with respect to various aspects of muscle biology.
Synthesis of β‐Pyrrolic‐Modified Porphyrins and Their Incorporation into DNA
Authors: Stephenson Adam W. I. , Partridge Ashton C. , Filichev Vyacheslav V.
Published: April 2011

A synthetic methodology for the synthesis of various β‐pyrrolic‐functionalised porphyrins and their covalent attachment to 2′‐deoxyuridine and DNA is described. Palladium(0)‐catalysed Sonogashira and copper(I)‐catalysed Huisgen 1,3‐dipolar cycloaddition reactions were used to insert porphyrins into the structure of 2′‐deoxyuridine and DNA. Insertion of a porphyrin into the middle of single‐stranded CT oligonucleotides possessing a 5′‐terminal run of four cytosines was shown to trigger the formation of pH‐ and temperature‐dependent i‐motif structures. Porphyrin insertion also led to the aggregation of single‐stranded purine–pyrimidine sequences, which could be dissociated by heating at 90 °C for 5 min. Parallel triplexes and anti‐parallel duplexes were formed in the presence of the appropriate complementary strand(s). Depending on the modification, porphyrins were placed in the major and minor grooves of duplexes and were used as bulged intercalating insertions in duplexes and triplexes. In general, the thermal stabilisation of parallel triplexes possessing porphyrin‐modified triplex‐forming oligonucleotide (TFO) strands was observed, whereas anti‐parallel duplexes were destabilised. These results are compared and discussed on the basis of the results of molecular modelling calculations.
Enantioselective Copper‐Catalysed Propargylic Substitution: Synthetic Scope Study and Application in Formal Total Syntheses of (+)‐Anisomycin and (−)‐Cytoxazone
Authors: Detz Remko J. , Abiri Zohar , le Griel Remi , Hiemstra Henk , van Maarseveen Jan H.
Published: April 2011

A copper catalyst with a chiral pyridine‐2,6‐bisoxazoline (pybox) ligand was used to convert a variety of propargylic esters with different side chains (R=Ar, Bn, alkyl) into their amine counterparts in very high yields and with good enantioselectivities (up to 90 % enantiomeric excess (ee)). Different amine nucleophiles were applied in the reactions and the highest enantioselectivities were obtained for aniline and its analogues. Interestingly, some carbon nucleophiles could also be used and with indoles excellent ee values were obtained (up to 98 % ee). The versatility of the propargylic amines obtained was demonstrated by their further elaboration to formal total syntheses of the antibiotic (+)‐anisomycin and the cytokine modulator (−)‐cytoxazone.
Virus‐Sized DNA Nanoparticles for Gene Delivery Based on Micelles of Cationic Calixarenes
Authors: Rodik Roman V. , Klymchenko Andrey S. , Jain Namrata , Miroshnichenko Stanislav I. , Richert Ludovic , Kalchenko Vitaly I. , Mély Yves
Published: April 2011

Macrocyclic amphiphilic molecules based on calix[4]arenes are highly attractive for controlled supramolecular assembly of DNA into small nanoparticles, since they present a unique conical architecture and can bear multiple charged groups. In the present work, we synthesized new amphiphilic calixarenes bearing cationic groups at the upper rim and alkyl chains at the lower rim. Their self‐assembly in aqueous solution was characterized by fluorescent probes, fluorescence correlation spectroscopy, dynamic light scattering, gel electrophoresis and atomic force microscopy. We found that calixarenes bearing long alkyl chains (octyl) self‐assemble into micelles of 6 nm diameter at low critical micellar concentration and present the unique ability to condense DNA into small nanoparticles of about 50 nm diameter. In contrast, the short‐chain (propyl) analogues that cannot form micelles at low concentrations failed to condense DNA, giving large polydisperse DNA complexes. Thus, formation of small DNA nanoparticles is hierarchical, requiring assembly of calixarenes into micellar building blocks that further co‐assemble with DNA into small virus‐sized particles. The latter showed much better gene transfection efficiency in cell cultures relative to the large DNA complexes with the short‐chain analogues, which indicates that gene delivery of calixarene/DNA complexes depends strongly on their structure. Moreover, all cationic calixarenes studied showed low cytotoxicity. Thus, this work presents a two‐step hierarchical assembly of small DNA nanoparticles for gene delivery based on amphiphilic cone‐shaped cationic calixarenes.