bluuebunny/crossref_metadata_2025 huggingface dataset:
Obwaldner Forstgeschichte: Basis für eine erfolgreiche Zukunft | Forestry history of canton Obwald: a basis for future success
Authors: Lienert Peter
Published: July 2010

Canton Obwald has a total surface area of about 50 000 hectares. Approximately 40% of this area is covered by forest. According to maps detailing the protective forests, over 70% of the forest serves as a protection from natural hazards, above all in the places characterized by mountain torrents reaching the valley floor. But the Ob-wald forests, together with the open pastures, also offer a habitat for a great variety of animals and plants and are recreational areas for residents and guests alike. In the article, some sectors are presented in which the geographically small canton Obwald has played a pioneering role, such as: the creation of maps based on phytoso-ciological surveys, covering the whole area, and available since 1982; forest development management with the help of forest development planning and a level of exploitation fixed by the canton; the creation of canton-wide natural hazard maps and in addition the integral projects, in which projects for the protection from natural hazards are planned and carried out as a whole.
The zoological notes by Johann Reinhold and George Forster included in Buffon's Histoire Naturelle (1782)
Authors: ROOKMAAKER L. C.
Published: July 2010

Buffon added 14 notes contributed by one or both of the Forsters to the sixth supplement of the Histoire Naturelle published in Paris in 1782. All these additions deal with mammals, mainly South African: nine South African antelopes, the spring hare, tame sheep and three antelopes not found at the Cape of Good Hope. The descriptions are compared with the drawings by George Forster in the British Museum (Natural History) and with the Descriptiones Animalium written by J. R. Forster about 1775, but not published until 1844. Buffon included two plates engraved after drawings made by George Forster depicting the klipspringer and spring hare.
A nineteenth century botanical text-book in the Malagasy language
Authors: DORR LAURENCE J.
Published: July 2010

A botanical text-book written by the Rev. Richard Baron (1847–1907), an English missionary in Madagascar, and first published in 1882 in the Malagasy language is discussed. The text-book borrowed heavily from several nineteenth century English botanical texts that are identified. The book was used for classes at the London Missionary Society Theological College in Antananarivo, Madagascar and although there were two editions of it no copies of the first edition can be located, and only a few copies of the second edition appear to have survived.
Charles Darwin'sBeagleCollections in the Oxford University Museum
Authors: CHANCELLOR GORDON , DiMAURO ANGELO , INGLE RAY , KING GILLIAN
Published: July 2010

SUMMARY

One hundred and ten numbered lots of zoological specimens and several specimens of rocks collected by Charles Darwin during the second voyage of H.M.S. Beagle (1831–1836) are contained in the collections of the Oxford University Museum. The circumstances which led to their acquisition are outlined. Most of this material comprises “higher” crustaceans but a few other invertebrate groups are also represented. A systematic identification has been made of these specimens and their condition is briefly described.
Antoni Gaymans (ca 1630–1680) and his herbaria
Authors: HENIGER J. , SOSEF M. S. M.
Published: July 2010

SUMMARY

The Leiden pharmacist Antoni Gaymans made two herbaria. One dates from 1661 and includes many polynomials added by the English botanist William Sherard. A written statement from Thomas Molyneux states that the specimens were collected in the Leiden Hortus Botanicus. The second herbarium consists of three volumes and dates from 1669–1674 (-1676). The Leiden botanist Paul Hermann added many names. A comparison of its contents with an early catalogue of the Leiden Hortus and the presence of certain species leads to the conclusion that these specimens, too, probably originated in this garden. Many Mediterranean species and North American introductions are present in the herbaria. Five early introductions from the Cape of Good Hope are also present.
The “Shetland Mammoth”: its age, nature and possible origin
Authors: LONG D.
Published: July 2010

The alleged mammoth tusks which were trawled up off Shetland in the early 1930s have been reexamined. They are believed to be Recent elephant tusks. It is suggested that they originated from the cargo lost at sea by a ship of the Dutch East India Company in 1690.
William Smith's explanation of the colliers' dial, 1798
Authors: FULLER J.G.C.M.
Published: July 2010

There is a faintly pencilled note, dated 1798, in the William Smith archive at Oxford, which describes a colliers' method for measuring directions of dip and strike in the East Somerset coalfield. It explains some otherwise obscure passages in John Strachey's published records of local stratigraphy (Strachey, 1719; 1727), and it illuminates Smith's own interest in recording dip-directions of coals at collieries near High Littleton, where he had begun surveying work in 1791. His note is accompanied by drawings of two varieties of compass-dial, or circumferentor, naming these collieries.
The invention and first use of stratigraphic cross-sections by John Strachey, F.R.S., (1671–1743)
Authors: FULLER J.G.C.M.
Published: July 2010

Stratigraphic cross-sections, or horizontally extended representations of strata in profile, were introduced into scientific literature in the year 1719 by John Strachey, of Sutton Court, near Stowey Somersetshire, England. Before that time, English-language stratigraphical geology had been practised chiefly by drillers searching for coal, whose published records of vertical sequences of strata and of lateral correlations among subsurface borehole sections, go back to 1639.

Strachey's sections were new in several ways: they were drawings rather than lists of strata, they represented true dips, and most importantly they demonstrated stratigraphic correlation in the subsurface and across landscape gaps, where for structural or topographic reasons the intervening strata were obscured or missing.

To achieve such delineations in the form of drawings or “draughts”, Strachey assumed as selfevident that the strata were regular in their order of superposition and that they had lateral continuity through concealed areas. His published observations and measurements were widely copied, and William Smith, generally regarded as one of the fathers of geology, seems to have found significant inspiration among Strachey's writings.
The accumulation and disposal of Gideon Mantell's fossil collections and their role in the history of British palaeontology
Authors: CLEEVELY R.J. , CHAPMAN S.D.
Published: July 2010

Through his early interest in fossils, Mantell participated in the geological exploration of the Weald and the Chalk Downs around Lewes. The material he accumulated contributed to the descriptive phase of British palaeontology and formed his notable museums at Lewes and Brighton, before its eventual acquisition by the British Museum. The nature of his collections, their significance and use in the interpretation of both vertebrate and invertebrate fossils and our knowledge of Cretaceous faunas, are discussed.
The dates of Schmiedeknecht's Apidae Europaeae
Authors: BAKER D.B.
Published: July 2010

Otto Schmiedeknecht's Apidae Europaeae was published in fascicles at various dates between 1882 and 1886. The make-up of the book is complex, and subsequent authors have frequently given inexact dates when referring to Schmiedeknecht's work. The present paper seeks to establish the intended sequence of text elements and to indicate dates of publication.
Priorities of publication for some nineteenth-century works describing new taxa of Hymenoptera, principally Apoidea
Authors: BAKER D.B.
Published: July 2010

Various important taxonomic works on Hymenoptera, more particularly Apoidea, collided about the years 1841 and 1879, and erroneous dates appear in standard references and recent work. The present paper seeks to establish priorities for works of Léon Dufour, Wilhelm Ferdinand Erichson, Comte Amédée Lepeletier de Saint-Fargeau, Sándor Mocsáry, Jean Pérez and Frederick Smith.
The zoological collections of the British Museum (Natural History) – evacuation of the collections during the war years 1939–1945
Authors: WHEELER ALWYNE
Published: July 2010

The precautions taken to safeguard the type and other important specimens in the zoological collections of the British Museum (Natural History) before and during the 1939–1945 war are recounted.
Inspiration from Nature and some plays written by John O'Keeffe (1747–1833)
Authors: ARCHER JEAN BARBARA , DAVIES GORDON LESLIE HERRIES
Published: July 2010

The natural world inspires human minds into a multitude of varied forms of intellectual creativity. The outcome of that inspirational influence is works as different as Newton's Principia, the reclining forms of Henry Moore, and the five movements of Von Grofé's Grand Canyon suite. Among such creative minds, that of the playwright is seemingly less likely to be influenced by the observational realities of the non-human natural world than is that of the scientist, the sculptor, or the musician. The once popular Irish playwright John O'Keeffe (1747–1833) is nevertheless one writer for the theatre who did, upon several occasions, find his basic inspiration within the phenomena displayed by the natural world. Attention is drawn to three 'natural history' plays which certainly came from the pen of O'Keeffe, and there is mentioned a fourth play of similar genre which is probably to be attributed to the same author.
Characterization of Biomaterials by Soft X-Ray Spectromicroscopy
Authors: Leung Bonnie O. , Brash John L. , Hitchcock Adam P.
Published: July 2010

Synchrotron-based soft X-ray spectromicroscopy techniques are emerging as useful tools to characterize potentially biocompatible materials and to probe protein interactions with model biomaterial surfaces. Simultaneous quantitative chemical analysis of the near surface region of the candidate biomaterial, and adsorbed proteins, peptides or other biological species can be obtained at high spatial resolution via scanning transmission X-ray microscopy (STXM) and X-ray photoemission electron microscopy (X-PEEM). Both techniques use near-edge X-ray absorption fine structure (NEXAFS) spectral contrast for chemical identification and quantitation. The capabilities of STXM and X-PEEM for the analysis of biomaterials are reviewed and illustrated by three recent studies: (1) characterization of hydrophobic surfaces, including adsorption of fibrinogen (Fg) or human serum albumin (HSA) to hydrophobic polymeric thin films, (2) studies of HSA adsorption to biodegradable or potentially biocompatible polymers, and (3) studies of biomaterials under fully hydrated conditions. Other recent applications of STXM and X-PEEM to biomaterials are also reviewed.
Retrieval of Leaf Area Index (LAI) and Soil Water Content (WC) Using Hyperspectral Remote Sensing under Controlled Glass House Conditions for Spring Barley and Sugar Beet
Authors: Borzuchowski Jaromir , Schulz Karsten
Published: July 2010

Leaf area index (LAI) and water content (WC) in the root zone are two major hydro-meteorological parameters that exhibit a dominant control on water, energy and carbon fluxes, and are therefore important for any regional eco-hydrological or climatological study. To investigate the potential for retrieving these parameter from hyperspectral remote sensing, we have investigated plant spectral reflectance (400–2,500 nm, ASD FieldSpec3) for two major agricultural crops (sugar beet and spring barley) in the mid-latitudes, treated under different water and nitrogen (N) conditions in a greenhouse experiment over the growing period of 2008. Along with the spectral response, we have measured soil water content and LAI for 15 intensive measurement campaigns spread over the growing season and could demonstrate a significant response of plant reflectance characteristics to variations in water content and nutrient conditions. Linear and non-linear dimensionality analysis suggests that the full band reflectance information is well represented by the set of 28 vegetation spectral indices (SI) and most of the variance is explained by three to a maximum of eight variables. Investigation of linear dependencies between LAI and soil WC and pre-selected SI’s indicate that: (1) linear regression using single SI is not sufficient to describe plant/soil variables over the range of experimental conditions, however, some improvement can be seen knowing crop species beforehand; (2) the improvement is superior when applying multiple linear regression using three explanatory SI’s approach. In addition to linear investigations, we applied the non-linear CART (Classification and Regression Trees) technique, which finally did not show the potential for any improvement in the retrieval process.
Cholera-Like Enterotoxins and Regulatory T cells
Authors: Basset Christelle , Thiam Fatou , Di Martino Cyrille , Holton John , Clements John D. , Kohli Evelyne
Published: July 2010

Cholera toxin (CT) and the heat-labile enterotoxin of E. coli (LT), as well as their non toxic mutants, are potent mucosal adjuvants of immunization eliciting mucosal and systemic responses against unrelated co-administered antigens in experimental models and in humans (non toxic mutants). These enterotoxins are composed of two subunits, the A subunit, responsible for an ADP-ribosyl transferase activity and the B subunit, responsible for cell binding. Paradoxically, whereas the whole toxins have adjuvant properties, the B subunits of CT (CTB) and of LT (LTB) have been shown to induce antigen specific tolerance when administered mucosally with antigens in experimental models as well as, recently, in humans, making them an attractive strategy to prevent or treat autoimmune or allergic disorders. Immunomodulation is a complex process involving many cell types notably antigen presenting cells and regulatory T cells (Tregs). In this review, we focus on Treg cells and cholera-like enterotoxins and their non toxic derivates, with regard to subtype, in vivo/in vitro effects and possible role in the modulation of immune responses to coadministered antigens.
Development of a System that Generates Structured Reports for Chest X-ray Radiography
Authors: Matsumura Y. , Mihara N. , Kawakami Y. , Sasai K. , Takeda H. , Nakamura H. , Hasegawa Y.
Published: July 2010

Objectives: Radiology reports are typically made in narrative form; this is a barrier to the implementation of advanced applications for data analysis or a decision support. We developed a system that generates structured reports for chest x-ray radiography.

Methods: Based on analyzing existing reports, we determined the fundamental sentence structure of findings as compositions of procedure, region, finding, and diagnosis. We categorized the observation objects into lung, mediastinum, bone, soft tissue, and pleura and chest wall. The terms of region, finding, and diagnosis were associated with each other. We expressed the terms and the relations between the terms using a resource description framework (RDF) and developed a reporting system based on it. The system shows a list of terms in each category, and modifiers can be entered using templates that are linked to each term. This system guides users to select terms by highlighting associated terms. Fifty chest x-rays with abnormal findings were interpreted by five radiologists and reports were made either by the system or by the free-text method.

Results: The system decreased the time needed to make a report by 12.5% compared with the free-text method, and the sentences generated by the system were well concordant with those made by free-text method (F-measure = 90%). The results of the questionnaire showed that our system is applicable to radiology reports of chest x-rays in daily clinical practice.

Conclusions: The method of generating structured reports for chest x-rays was feasible, because it generated almost concordant reports in shorter time compared with the free-text method.
Adiciones a la fauna de Piophilidae (Diptera) de Portugal, con nuevas citas
Authors: Prado e Castro C. , García M. D.
Published: July 2010

No disponible
Managing Brief Data from Users to Professionals
Authors: Noguera José Manuel
Published: July 2010

Microblogging‘s explosion has provoked changes in the Blogosphere (now bloggers prefer to publish brief content in microblogs), and it has changed some roles in journalism too. Twitter is the most important tool in this phenomenon and it has served to keep connected sources, journalists and audiences. In recent years, media and news agencies are being characterized by an intensive use of microblogs. Journalists start to be collaborate within communities of interests trough microblogging, in particular Twitter. Facts like California fires are a clear example of Twitter coverages, which were started by users and gathered by journalists. This is more than a brief and fast tool for journalism, it is related with making connections with audiences, witnesses and sources of breaking news. In this sense, this chapter will show several examples in order to explain how Twitter is a new way to design collaborative coverages. Hence, it is not just a platform on fashion.
Microfluidic Applications in Vascular Bioengineering
Authors: Srinivasan Anand , López-Ribot José L. , Ramasubramanian Anand K.
Published: July 2010

Microfluidics is the manipulation and control of fluids in small scale, and has heralded a new age in science as evidenced by the rapid increase in the amount and quality of academic and industrial research output in this area in the recent times. Microfluidics has shown tremendous promise in both fundamental and applied research in the field of vascular bioengineering. In this review, we outline the basic principles of microfluidic flow and fabrication techniques, and describe the recent advances in the applications of microfluidic devices in diagnostic and prognostic vascular bioengineering. The field is still in its infancy and has a great potential for research and development as it matures to deliver commercially viable products. This review, focusing on the current status of microfluidic applications to diagnose and treat blood-related disorders, should be a valuable and opportune addition to the literature of interest to both academia and industry.
Towards Cognitive Machines
Authors: Kinsner Witold
Published: July 2010

Numerous attempts are being made to develop machines that could act not only autonomously, but also in an increasingly intelligent and cognitive manner. Such cognitive machines ought to be aware of their environments, which include not only other machines, but also human beings. Such machines ought to understand the meaning of information in more human-like ways by grounding knowledge in the physical world and in the machines’ own goals. The motivation for developing such machines range from self-evidenced practical reasons such as the expense of computer maintenance, to wearable computing in health care, and gaining a better understanding of the cognitive capabilities of the human brain. To achieve such an ambitious goal requires solutions to many problems, ranging from human perception, attention, concept creation, cognition, consciousness, executive processes guided by emotions and value, and symbiotic conversational human-machine interactions. An important component of this cognitive machine research includes multiscale measures and analysis. This article presents definitions of cognitive machines, representations of processes, as well as their measurements, measures, and analysis. It provides examples from current research, including cognitive radio, cognitive radar, and cognitive monitors.
Handling Large Medical Data Sets for Disease Detection
Authors: Kala Rahul , Shukla Anupam , Tiwari Ritu
Published: July 2010

The breakthrough in the field of intelligent systems has spread its fruits to the field of biomedical engineering as well; where a series of models are being applied to automatically detect diseases based on some parameters or inputs. The continuous research in this field has resulted in a large amount of database being created for many diseases which becomes very difficult to train. Also the number of attributes is under constant rise. This increases the dimensionality of the problem and ultimately leads to poor performance. In this chapter we deal with the methods to handle these situations. We discuss the mechanism to divide data between different sub-systems. We also discuss the method of division of the attributes to reduce the training time and complexity. The resultant systems are able to train better due to low computational cost and hence give better performance. We validated this with the Breast Cancer database from the UCI Machine Learning repository and found our algorithm optimal.
Medical Transcription a pioneer in the Healthcare Informatics
Authors: Srivastava Shilpi
Published: July 2010

Despite the importance of medical records, relatively little is known about medical transcription, a process through which voice files are transformed into healthcare documentation. This lack of knowledge is evident in academic research with no previous studies of medical transcriptionists (MTs) or the medical transcription service organizations (MTSOs) in existence despite the central role of the industry in the creation of healthcare documentation. The proposed chapter is a detailed ethnographic study of the medical transcription process. While its general aim is to document the impact of technology on the process of medical transcription, the topic resides in a broader array of issues that include the impact of technology on the workplace, and how assumptions of work drive technological design. The central issue being examined is what is the extent to which technology can replace workers and how design decisions impact practice by either facilitating or impeding it. Given the thing being produced is vital for medical treatment, resolving this question is not only of academic interest, but important to everyone who has a medical record.
Analysis and Prediction of DNA-Recognition by Zinc Finger Proteins
Authors: Sarkar Anita , Kumar Sonu , Punetha Ankita , Grover Abhinav , Sundar Durai
Published: July 2010

Zinc fingers are the most abundant class of DNA-binding proteins encoded in the eukaryotic genomes. Custom-designed zinc finger proteins attached to various DNA-modifying domains can be used to achieve highly specific genome modification, which has tremendous applications in molecular therapeutics. Analysis of sequence and structure of the zinc finger proteins provides clues for understanding protein-DNA interactions and aid in custom-design of zinc finger proteins with tailor-made specificity. Computational methods for prediction of recognition helices for C2H2 zinc fingers that bind to specific target DNA sites could provide valuable insights for researchers interested in designing specific zinc finger proteins for biological and biomedical applications. In this chapter, we describe the zinc finger protein-DNA interaction patterns, challenges in engineering the recognition-specificity of zinc finger proteins, the computational methods of prediction of proteins that recognize specific target DNA sequence and their applications in molecular therapeutics.
Moduli Spaces of Reflexive Sheaves of Rank 2
Authors: Kleppe Jan O.
Published: July 2010

Let ℱ be a coherent rank 2 sheaf on a scheme Y ⊂ ℙn of dimension at least two and let X ⊂ Y be the zero set of a section σ ∈ H0(ℱ). In this paper, we study the relationship between the functor that deforms the pair (ℱ, σ) and the two functors that deform F on Y, and X in Y, respectively. By imposing some conditions on two forgetful maps between the functors, we prove that the scheme structure of e.g., the moduli scheme MY(P) of stable sheaves on a threefold Y at (ℱ), and the scheme structure at (X) of the Hilbert scheme of curves on Y become closely related. Using this relationship, we get criteria for the dimension and smoothness of MY(P) at (ℱ), without assuming Ext2(ℱ,ℱ) = 0. For reflexive sheaves on Y = ℙ3 whose deficiencymodule M = H*1 (ℱ) satisfies 0Ext2(M,M) = 0 (e.g., of diameter at most 2), we get necessary and sufficient conditions of unobstructedness that coincide in the diameter one case. The conditions are further equivalent to the vanishing of certain graded Betti numbers of the free graded minimal resolution of H*0 (ℱ). Moreover, we show that every irreducible component of Mℙ3 (P) containing a reflexive sheaf of diameter one is reduced (generically smooth) and we compute its dimension. We also determine a good lower bound for the dimension of any component of Mℙ3 (P) that contains a reflexive stable sheaf with “small” deficiency module M.
Calculation of signal spectrum by means of stochastic inversion
Authors: Nygrén T. , Ulich Th.
Published: July 2010

Abstract. The standard method of calculating the spectrum of a digital signal is based on the Fourier transform, which gives the amplitude and phase spectra at a set of equidistant frequencies from signal samples taken at equal intervals. In this paper a different method based on stochastic inversion is introduced. It does not imply a fixed sampling rate, and therefore it is useful in analysing geophysical signals which may be unequally sampled or may have missing data points. This could not be done by means of Fourier transform without preliminary interpolation. Another feature of the inversion method is that it allows unequal frequency steps in the spectrum, although this property is not needed in practice. The method has a close relation to methods based on least-squares fitting of sinusoidal functions to the signal. However, the number of frequency bins is not limited by the number of signal samples. In Fourier transform this can be achieved by means of additional zero-valued samples, but no such extra samples are used in this method. Finally, if the standard deviation of the samples is known, the method is also able to give error limits to the spectrum. This helps in recognising signal peaks in noisy spectra.
Sex differences in relational and overt aggression in the late elementary school years
Authors: Kistner Janet , Counts‐Allan Carla , Dunkel Stephanie , Drew Catherine Hardee , David‐Ferdon Corinne , Lopez Cristina
Published: July 2010

Sex differences in relational and overt aggression among 3rd (n=176), 4th (n=179), and 5th graders (n=145) from three public schools (n=500; 278 girls) were examined. Nominations of relational aggression increased over time among 4th and 5th grade girls, but not among boys or 3rd grade girls. Among 3rd graders, boys received more nominations for relational aggression than girls. By the end of the 5th grade, girls received more relational aggression nominations than boys. There was also a significant rise in nominations of overt aggression among 5th grade girls, but not among 5th grade boys or younger boys and girls. As expected, boys were more likely than girls to be nominated for overt aggression at all grade levels. The findings are helpful for explaining inconsistencies of earlier research pertaining to sex differences in relational aggression and for advancing our understanding of the causes of aggression. Aggr. Behav. 36:282–291, 2010. © 2010 Wiley‐Liss, Inc.
The Effects of Moisture in Low‐Voltage Organic Field‐Effect Transistors Gated with a Hydrous Solid Electrolyte
Authors: Kaihovirta Nikolai , Aarnio Harri , Wikman Carl‐Johan , Wilén Carl‐Eric , Österbacka Ronald
Published: July 2010

The concept of using ion conducting membranes (50–150 μm thick) for gating low‐voltage (1 V) organic field‐effect transistors (OFETs) is attractive due to its low‐cost and large‐area manufacturing capabilities. Furthermore, the membranes can be tailor‐made to be ion conducting in any desired way or pattern. For the electrolyte gated OFETs in general, the key to low‐voltage operation is the electrolyte “insulator” (the membrane) that provides a high effective capacitance due to ionic polarization within the insulator. Hydrous ion conducting membranes are easy to process and readily available. However, the role of the water in combination with the polymeric semiconductor has not yet been fully clarified. In this work electrical and optical techniques are utilized to carefully monitor the electrolyte/semiconductor interface in an ion conducting membrane based OFET. The main findings are that 1) moisture plays a major part in the transistor operation and careful control of both the ambient atmosphere and the potential differences between the electrodes are required for stable and consistent device behavior, 2) the obtained maximum effective capacitance (5 μF cm−2) of the membrane suggests that the electric double layer is distributed over a broad region within the polyelectrolyte, and 3) electromodulation spectroscopy combined with current–voltage characteristics provide a method to determine the threshold gate voltage from an electrostatic field‐effect doping to a region of (irreversible) electrochemical perturbation of the polymeric semiconductor.
Palladium‐Catalyzed Aryl Amination Reactions of 6‐Bromo‐ and 6‐Chloropurine Nucleosides
Authors: Thomson Paul F. , Lagisetty Pallavi , Balzarini Jan , De Clercq Erik , Lakshman Mahesh K.
Published: July 2010

Palladium‐catalyzed CN bond forming reactions of 6‐bromo‐ as well as 6‐chloropurine ribonucleosides and the 2′‐deoxy analogues with arylamines are described. Efficient conversions were observed with palladium(II) acetate/Xantphos/cesium carbonate, in toluene at 100 °C. Reactions of the bromonucleoside derivatives could be conducted at a lowered catalytic loading [5 mol% Pd(OAc)2/7.5 mol% Xantphos], whereas good product yields were obtained with a higher catalyst load [10 mol% Pd(OAc)2/15 mol% Xantphos] when the chloro analogue was employed. Among the examples evaluated, silyl protection for the hydroxy groups appears better as compared to acetyl. The methodology has been evaluated via reactions with a variety of arylamines and by synthesis of biologically relevant deoxyadenosine and adenosine dimers. This is the first detailed analysis of aryl amination reactions of 6‐chloropurine nucleosides, and comparison of the two halogenated nucleoside substrates.
One‐Pot Synthesis of Polyfunctionalized 4H‐Chromenes and Dihydrocoumarins Based on Copper(II) Bromide‐Catalyzed CC Coupling of Benzylic Alcohols with Ketene Dithioacetals
Authors: Liang Deqiang , Wang Mang , Bekturhun Bahargul , Xiong Binbin , Liu Qun
Published: July 2010

The synthesis of polyfunctionalized 4H‐chromenes 3 and dihydrocoumarins 4 has been developed from the same substrates. Catalyzed by copper(II) bromide (0.3 equiv.), the reactions of the easily available ketene dithioacetals 1 with 2‐(hydroxymethyl)phenols 2 lead to 4H‐chromenes 3 in high to excellent yields in dichloromethane solvent, whereas, 3,4‐trans‐disubstituted dihydrocoumarins 4 are obtained in high yields with high diastereoselectivities by prolonging the reaction time or changing the solvent from dichloromethane to acetonitrile.
Regio‐ and Stereoselective Intermolecular Hydroalkoxylation of Alkynes Catalysed by Cationic Gold(I) Complexes
Authors: Corma Avelino , Ruiz Violeta R. , Leyva‐Pérez Antonio , Sabater María J.
Published: July 2010

Vinyl ethers and ketals are obtained from the reaction of phenylacetylene derivatives and dimethyl acetylenedicarboxylate (DMAD) with alcohols in good yields and levels of stereoselectivity by using cationic gold(I)‐phosphine complexes as catalysts. By choosing the appropriate phosphine, the selective formation of the Z or the E isomer of the vinyl ether can be tuned, and the undesired formation of the ketal can be controlled. The isomerisation of fumarates (Z‐isomer) to maleates (E‐isomer) is a gold‐catalysed process that can be conducted in one‐pot. When using polyols, 5‐membered cyclic ketals are easily isolated by extraction with hexane and the gold complex can be reused.
Palladium on Carbon‐Catalyzed Synthesis of Benzil Derivatives from 1,2‐Diarylalkynes with DMSO and Molecular Oxygen as Dual Oxidants
Authors: Mori Shigeki , Takubo Masato , Yanase Takayoshi , Maegawa Tomohiro , Monguchi Yasunari , Sajiki Hironao
Published: July 2010

A palladium on carbon (Pd/C)‐catalyzed synthetic method for the preparation of benzil derivatives from 1,2‐diarylalkynes has been established using dimethyl sulfoxide (DMSO) and molecular oxygen as dual oxidants. Regardless of the electrical nature of the functional groups on the aromatic rings, 1,2‐diarylalkynes were oxidized to the corresponding benzil derivatives in high to excellent yields. Furthermore, the oxidation could efficiently be catalyzed by both the dry and wet types of Pd/C under atmospheric conditions.
Applicability domains and accuracy of prediction of soft sensor models
Authors: Kaneko Hiromasa , Arakawa Masamoto , Funatsu Kimito
Published: July 2010

Soft sensors are used to estimate process variables that are difficult to measure online. However, the predictive accuracy gradually decreases with changes in the state of chemical plants. Regression models can be updated, but if the model is updated with abnormal data, the predictive ability deteriorates. In practice, when the prediction error of an objective variable exceeds a threshold, an abnormal situation is detected. However, no effective method exists to decide this threshold. We have proposed a method to estimate the relationships between applicability domains and the accuracy of prediction of soft sensor models quantitatively. The larger the distances to models (DMs), the lower the estimated accuracy of prediction. Hence, the model between DMs and accuracy can separate variations in process variables and y‐analyzer fault. This method was applied to real industrial data. The fault detection ability of the proposed method was better than that of the traditional one. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Conductance of inhomogeneous systems: Real‐time dynamics
Authors: Branschädel A. , Schneider G. , Schmitteckert P.
Published: July 2010

Numerical time evolution of transport states using time dependent Density Matrix Renormalization Group (td‐DMRG) methods has turned out to be a powerful tool to calculate the linear and finite bias conductance of interacting impurity systems coupled to non‐interacting one‐dimensional leads. Several models, including the Interacting Resonant Level Model (IRLM), the Single Impurity Anderson Model (SIAM), as well as models with different multi site structures, have been subject of investigations in this context. In this work we give an overview of the different numerical approaches that have been successfully applied to the problem and go into considerable detail when we comment on the techniques that have been used to obtain the full I–V‐characteristics for the IRLM. Using a model of spinless fermions consisting of an extended interacting nanostructure attached to non‐interacting leads, we explain the method we use to obtain the current–voltage characteristics and discuss the finite size effects that have to be taken into account. We report results for the linear and finite bias conductance through a seven site structure with weak and strong nearest‐neighbor interactions. Comparison with exact diagonalisation results in the non‐interacting limit serve as a verification of the accuracy of our approach. Finally we discuss the possibility of effectively enlarging the finite system by applying damped boundaries and give an estimate of the effective system size and accuracy that can be expected in this case.
Pd nanoparticles dispersed on solid supports: synthesis, characterization and catalytic activity on selective hydrogenation of olefins in aqueous media
Authors: Lim Minkyung , De Castro Kathlia A. , Oh Seungchan , Lee Kangsuk , Chang Young‐Wook , Kim Hokun , Rhee Hakjune
Published: July 2010

Two types of Pd nanoparticle catalysts were prepared having 2–4 nm particle size using silica gel and porous polymer beads as solid supports. 2‐Pyridinecarboxaldehyde ligand was anchored on commercially available 3‐aminopropyl‐functionalized silica gel followed by Pd metal dispersion. Bead‐shaped cross‐linked poly(4‐vinylpyridine‐co‐styrene) gel was prepared by an emulsifier‐free emulsion polymerization of 4‐vinylpyridine, styrene and divinylbenzene in the presence of ammonium persulfate and subsequently dispersing the Pd metal on the synthesized polymer. These catalysts were characterized by SEM, TEM and ICP techiniques with respect to appearance, size and possible leaching out, respectively. Furthermore, the reactivity of these catalysts was tested on hydrogenation of various α,β‐unsaturated carbonyl compounds using aqueous solvent under a hydrogen balloon (1 atm). The results showed that the Pd dispersed on silica was a more efficient catalyst than Pd dispersed on polymer and the former could be recycled more than 10 times without considerable loss in activity. Copyright © 2010 John Wiley & Sons, Ltd.
Study on morphology control and how to affect mechanical properties of polyimide/silica hybrid films
Authors: Jiaqiang Qin , Zhen Li , Yi Gu
Published: July 2010

A series of polyimide (PI)/silica hybrid films were prepared by sol–gel method, using hydrolyzed tetraethoxysilane and poly amic acid‐imides (PAA‐Is), which were different imidization degree controlled by chemical imidization method. The imidization degree was characterized by Fourier transform infrared spectra and their corresponding morphology was characterized by scanning electron microscopy. The results show that there are two kinds of silica particles and their formative morphology obeys the double phase separation mechanism. According to the increase of PAA‐I imidization degree, amount of nano silica particles decreased and the diameter of macro silica particles increased in the hybrid films. Tensile testing, dynamic mechanical analysis, and thermal mechanical analysis results show that, according to the amount of nano silica particles increasing, the hybrids have the higher the mechanical properties, glass transition temperature (Tg), and thermal expansion coefficient. Through controlling PI/silica hybrid films microstructure, its mechanical properties can be controlled. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of zwitterionic organogels based on Schiff base chemistry
Authors: Tarannum Nazia , Singh Meenakshi
Published: July 2010

Poly(sulfobetaine)s and poly(carboxybetaine)s have been extensively studied for their zwitterionic and biocompatible nature. The specific features that make such zwitterionic structures technologically important are their chemical structure, a straight forward synthetic route, high ionic contents with interesting dilute solution, and solid state properties. The objective of this work is to synthesize novel zwitterionic polymers having gel characteristics. Here, p‐phenylene diamine/melamine react as nucleophiles with glutaraldehyde to produce poly(schiff base)s. In the subsequent step, the poly(sulfobetaine)s and poly(carboxybetaine)s were produced on treatment with 1,3‐propane sultone/γ‐butyrolactone. Hence, a catalyst free facile approach to novel zwitterionic polymers was obtained. The polymers were characterized by elemental analyses, FTIR, XRD analyses, SEM, pH metric titrations, conductometric titrations, and thermal analyses (TGA/DTA). The polymeric samples carry the gel characteristics, showing lamellar structure with porous network. XRD pattern shows Bragg peaks indicative of superstructures. Thermal analysis indicates the Hoffman elimination of β hydrogen and subsequent release of sulfopropyl/carboxybutyl group. One of the gel polymers shows fluorescence also. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Nanofibers as carrier systems for antimicrobial microemulsions. II. Release characteristics and antimicrobial activity
Authors: Kriegel C. , Kit K. M. , McClements D. J. , Weiss J.
Published: July 2010

Antimicrobial nanofibers were prepared by electrospinning microemulsions composed of the essential oil component eugenol solubilized in an aqueous nonionic micellar surfactant solution (Surfynol®465) with poly(vinyl alcohol) (PVA). Nanofibers contained microemulsions composed of 0.75–1.5 wt% eugenol and 5–10 wt % Surfynol. Scanning electron microscopy revealed substantial difference in fiber morphology depending on microemulsion composition with fiber diameters increasing as the concentration of either surfactant or essential oil component in the fibers increased. Release studies suggested a burst release of the encapsulated eugenol, potentially due to the hydrophilicity of the polymeric carrier resulting in rapid dissolution of the carrier matrix and high‐fiber porosity. The eugenol release rate depended on the amount of eugenol and surfactant incorporated within the fibers. The antimicrobial activity of nanofibers carrying eugenol was evaluated against two strains of Salmonella typhimurium (2476 and 2576) and Listeria monocytogenes (Scott A and 101) using a macrobroth dilution assay. Presence of nanofibers in bacterial suspensions successfully suppressed growth of foodborne pathogens and in some cases decreased initial cell numbers. Generally, nanofibers were more efficient against Gram‒negative than Gram‒positive bacterial strains. Results suggest that addition of microemulsions carrying lipophilic components to polymer solutions subjected to electrospinning offers a novel means to further enhance the functionality of nanofibers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Properties improvement of PMMA using nano TiO2
Authors: Chatterjee Amit
Published: July 2010

TiO2 nanofillers (5 nm, 0–15% weight) have been introduced in the PMMA matrix using a twin screw extruder to increase the performance of PMMA. The twin screw extrusion process is optimized to disperse the particles into PMMA. Nanofiller infusion improves the thermal, mechanical, and UV absorption properties of PMMA. TiO2‐PMMA nanocomposites exhibit the increase in tensile modulus (˜90%), decomposition temperature (˜31%), dimension stability (∼ 60%) and UV absorption (∼ 410%). Properties of the nanoTiO2‐PMMA composites are depending on the dispersion of TiO2 in the PMMA matrix. It is interrelated with loading. Formation and disappearance of the peaks in FTIR confirm the chemical interaction of PMMA with TiO2. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Electrochemical synthesis of poly(methylsilyne) and investigation of the effects of parameters on the synthesis
Authors: Eroglu Damla , Nur Yusuf , Bayram Goknur , Toppare Levent K.
Published: July 2010

This study aims to synthesize poly(methylsilyne) by electrochemical reduction of methyltrichlorosilane at a constant potential of −6 V, while investigating the effects of parameters such as the nature of the electrode, solvent and supporting electrolyte, the monomer/solvent ratio, and the reaction time on the properties of the products. The polymer was characterized by 1H‐NMR (Proton Nuclear Magnetic Resonance Spectroscopy), FTIR (Fourier Transform Infrared Spectroscopy), UV‐Visible Spectroscopy, and TGA (Thermogravimetry Analysis). Copper (Cu) electrodes were used as stainless steel introduced impurities into the system. In an electrolytic media consisting of acetonitrile (AN), sodium dodecyl sulfate (SDS), and Cu electrodes, increasing the monomer/solvent ratio and the reaction time affected the system negatively based on the purity of poly(methylsilyne) in the final product. Reproducible results were only achieved in an electrolytic media containing 1,2‐dimethoxyethane (DME) and tetrabutylammonium perchlorate (TBAP). In this system, the purity of the products was less dependent on monomer/solvent ratio and reaction time. The color and the 1H‐NMR, FTIR, and UV‐Visible spectra proved that the product is poly(methylsilyne). In addition, the significantly high‐average decomposition temperature obtained from TGA results revealed that the polymer is a good candidate as an additive for improving thermal stability and flame retardancy in thermoplastics. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Stress cracking and chemical degradation of poly(ethylene terephthalate) in NaOH aqueous solutions
Authors: Teófilo E. T. , Silva S. M. L. , Rabello M. S.
Published: July 2010

Stress cracking is one of the most frequent causes of premature failure of polymers, affecting also engineering polymers like PET. In this work, the stress cracking behavior of injection moulded PET was investigated using sodium hydroxide (NaOH) aqueous solutions in various concentrations as active fluids. The application of mechanical load to the sample bars was done in a tensile testing machine, using the ordinary tensile test and also a relaxation procedure. The results showed that all NaOH solutions were aggressive stress cracking agents for PET, reducing mechanical properties and causing catastrophic failure with a significant surface damage. The occurrence of hydrolysis reactions was also observed when NaOH solutions were applied in combination with tensile loads, causing a reduction in molar mass of PET molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Using a Combination of Magnetic Anisotropic Effects for the Configurational Assignment of Amino Alcohols
Authors: Leiro Victoria , Seco José Manuel , Quiñoá Emilio , Riguera Ricardo
Published: July 2010

The combined magnetic anisotropic effects generated by two auxiliary moieties of 2‐methoxy‐2‐phenylacetic acid (MPA), introduced on two families of terminal 1,2‐amino alcohols (prim/sec and sec/prim), determine the signs of the ΔδRS parameters—the differences in chemical shifts between the bis‐(R)‐MPA and the bis‐(S)‐MPA esters—of the hydrogen atoms placed at both sides of the stereogenic carbon atoms, thereby allowing the determination of the absolute configuration of those heterobifunctional compounds. Theoretical (AM1, B3LYP) and experimental (CD, 3J, low‐temperature NMR spectroscopy, isotopic labeling) studies, together with testing with a number of representative compounds, permit one to establish the foundations of this methodology.
Magnetic resonance imaging-detected lymph nodes close to the mesorectal fascia are rarely a cause of margin involvement after total mesorectal excision
Authors: Shihab O C , Quirke P , Heald R J , Moran B J , Brown G
Published: July 2010

Background

In rectal cancer the management of suspicious magnetic resonance imaging (MRI)-detected lymph nodes lying close to the mesorectal fascia poses an ongoing dilemma. Key decisions in treatment planning are commonly based on the prediction of margin status. However, it is unclear whether a lymph node that appears to contain tumour close to the mesorectal fascia will result in a positive margin.

Methods

Some 396 patients with rectal cancer were included. MRI assessment of mesorectal nodes, the pathologically involved circumferential resection margin (CRM) rate and causes of margin involvement were analysed to establish the clinical significance of MRI-detected suspicious lymph nodes at the resection margin.

Results

Fifty (12·6 per cent) of 396 patients had a positive CRM on histopathological analysis, five (10 per cent) solely due to an involved lymph node. Four of the five malignant nodes were not predicted on MRI. Thirty-one of the 396 MRI studies had suspicious nodes 1 mm or less from the CRM. None of these patients had a positive CRM owing to nodal involvement.

Conclusion

Involvement of the CRM by lymph node metastases alone is uncommon.