bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of the Mitsunobu reaction to ephedrines and some related amino alcohols. Aspects of intramolecular participation of the amino group
Authors: Poelert Martin A. , Kellogg Richard M. , Hulshof L. A. 
Published: September 2010

AbstractInversion of configuration at the benzylic hydroxyl group of (1S,2S)‐pseudoephedrine (2) to afford (1R,2S)‐ephedrine is known to be a difficult process. The Mitsunobu reactions of 1 and 2 might offer a route to achieve such inversions. In fact Mitsunobu reactions on 1 and 2 are known to proceed via aziridines formed on intramolecular SN2 substitution by the amine functionality. The Mitsunobu reactions of N‐methylated and N‐benzylated ephedrines have been found to proceed via the corresponding aziridinium ions. These aziridinium ions can be opened (SN2 substitution) by nucleophiles like phthalimide and thiols. Intramolecular participation in 2 can be avoided by use of the tert‐butyloxycarbonyl‐ (BOC) or benzyloxycarbonyl‐ (CBZ) protected derivatives. Mitsunobu reactions on these derivatives lead to inversion of configuration at the benzylic hydroxyl center. In contrast the BOC and CBZ derivatives of 1 are deprotected under Mitsunobu conditions. The Mitsunobu reactions of threo (1S,2,S)‐2‐amino‐1,3‐propanediol have also been examined. An attempt to achieve protection by reaction with dimethylformamide dimethyl acetal led to the more substituted 2‐oxazoline as established by X‐ray crystallography. The desired inversion of configuration of the benzylic hydroxylic group was eventually achieved by protection of the amino substituent as the phthalimide and protection of the primary hydroxyl group as the tosylate.
Enantiomer separation of chiral inhalation anesthetics (enflurane, isoflurane and desflurane) by gas chromatography on a γ‐cyclodextrin derivative
Authors: Schurig Volker , Grosenick Heiko , Juza Markus 
Published: September 2010

AbstractThe preparative enantiomer separation of the inhalation anesthetics enflurane (1), isoflurane (2) and, for the first time, desflurane (3) in high chemical and enantiomeric purity by preparative gas chromatography on octakis(3‐O‐butanoyl‐2,6‐di‐O‐pentyl)‐γ‐cyclodextrin (4) dissolved in SE‐54 and coated on Chromosorb P (AW‐DMCS) is described. Thermodynamic data for the observed enantioselectivities are reported. A discrepancy between the chiroptical and gas‐chromatographic assignment of the relative configuration of2and3is discussed. The1H‐ and19F‐NMR spectra of racemic1in the presence of4show good separation of the resonances of the enantiomers of1. Thermodynamic complexation constants derived from the1H‐NMR spectra of the complexes formed by4and the enantiomers of1were in good agreement with those obtained by GC.
Solid support synthesis of a PNA‐DNA hybrid
Authors: van der Laan A. C. , Meeuwenoord N. J. , Kuyl‐Yeheskiely E. , Oosting R. S. , Brands R. , van Boom J. H. 
Published: September 2010

AbstractThe solid support synthesis of a homothymine PNA‐DNA octamer (i.e. hybrid 13) could be realized using tetrabutylammonium N‐(2‐(4‐methoxytrityl)‐aminoethyl)‐N‐((thymin‐1‐yl)acetyl)glycinate as PNA building block and the respective 2‐cyanoethyl‐N,N‐diisopropylphosphoramidite derivatives of both 5′‐O‐(4,4′‐dimethoxytrityl)thymidine and 5′‐N‐(4‐methoxytrityl)amino‐5′‐deoxythymidine.
Nanogel engineering for new nanobiomaterials: from chaperoning engineering to biomedical applications
Authors: Sasaki Yoshihiro , Akiyoshi Kazunari 
Published: September 2010

AbstractNanosize hydrogels (nanogels) are polymer nanoparticles with three‐dimensional networks, formed by chemical and/or physical cross‐linking of polymer chains. Recently, various nanogels have been designed, with a particular focus on biomedical applications. In this review, we describe recent progress in the synthesis of nanogels and nanogel‐integrated hydrogels (nanogel cross‐linked gels) for drug‐delivery systems (DDS), regenerative medicine, and bioimaging. We also discuss chaperone‐like functions of physical cross‐linking nanogel (chaperoning engineering) and organic‐inorganic hybrid nanogels. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Published online in Wiley InterScience (www.interscience.wiley.com)DOI 10.1002/tcr.201000008
Chlorophenol stress affects aromatic amino acid biosynthesis—a genome‐wide study
Authors: Yadav Vikas , Shitiz Kirti , Pandey Rishi , Yadav Jyoti 
Published: September 2010

AbstractChlorophenols are a class of chemicals commonly used in preservatives, disinfectants, algaecides, herbicides and pesticides. However, there is a growing evidence that these compounds are a threat to human health. This is alarming as many chlorophenols are common pollutants found in the global environment at potentially biohazardous levels. Despite chlorophenols being abundant, widely used and poisonous, we know relatively little about their mechanism of toxicity in eukaryotes. Thus, we performed genome‐wide growth screens usingSaccharomyces cerevisiaeto understand the molecular basis of chlorophenol toxicity. Of ∼4850 single gene knockout strains tested, 393 mutants showed growth sensitivity to treatment with 4‐chlorophenol (4‐CP), 2,4‐dichlorophenol (2,4‐DCP) or pentachlorophenol (PCP). Only eight mutants showed growth hypersensitivity to all the three treatments and harboured deletions in genes important for aromatic amino acid biosynthesis (ARO1, ARO7) or mitochondrial protein synthesis and respiration (ATP5, ISA1, RML2, GET2, SLS1, MRPL38). Copyright © 2010 John Wiley & Sons, Ltd.
Is it True that Injecting Palmar Finger Skin Hurts more than Dorsal Skin? New Level 1 Evidence
Authors: Wheelock Margaret E. , LeBlanc Martin , Chung Bryan , Williams Jason , Lalonde Donald H. 
Published: September 2010

Background Since the first texts on local anesthesia were written in the early 1900s, it has been widely quoted and believed that dorsal finger skin is less sensitive to needlestick pain than volar finger skin. The result is that the most commonly used finger block for local anesthesia is the dorsal two injection technique. Methods In this study, the needlestick discomfort associated with dorsal and volar finger skin was compared in a group of 78 volunteers who had the long finger of both hands poked with a 25 G needle; one in the midline of the volar side and the other in the lateral web space of the dorsal side. Volunteers then completed a pain scale for each needlestick and ranked which technique they would prefer for future injections. Results We found that there was no significant difference in needlestick pain or preference of future needle location between the dorsal and volar aspects of the finger. Conclusions We provide level 1 evidence that the needlestick of the SIMPLE block which has one needlestick on the volar side of the finger is not more painful than the needlestick of the dorsal finger block.
A life course approach: research orientations and future challenges
Authors: Heikkinen Eino 
Published: September 2010

Abstract
The need to study lifelong changes in health and functioning has resulted in increasing emphasis on a life course approach in different fields of inquiry. The aim of this approach is to explore how biological, psychological, and social risk factor trajectories, acting across the entire life course, influence age-related diseases, functional decline, and disability. The importance of the first years of life upon later development and adult characteristics was generally recognized already in the first half of the twentieth century, but it was not until the 1990s that different strands of medical and social research converge in the field of life course epidemiology, in which epidemiological processes are approached using different models such as biological programming, critical periods, pathways, and accumulation. The biological programming model holds that organ development in utero and early infancy determines the maximum functional capacity that an individual can attain and influences the development of certain chronic diseases later in life. The critical period model extends the idea to include child development and key social transitions over the entire life course. The pathway model focuses on the cumulative effect of life events along the developmental trajectories, with early advantage or disadvantage setting a person on a pathway to a later etiologically important exposure. The accumulation model describes the underlying social, behavioral, and biological processes that drive the impact of the life course on health. The growing focus on life course determinants of aging also has implications for studies of long-term changes in physical activity and their role in determining both gains and losses of health and functioning with aging. A life course approach presents great challenges for the continued development of testable theoretical models and effective study design and analysis.
Secondary immunodeficiency (immune paralysis) following spinal cord injury
Authors: Brommer B. , Kopp M.A. , Laginha I. , Schwab J.M. 
Published: September 2010

Abstract
Infections are a leading cause of morbidi­ty and mortality in patients with acute spinal cord injury (SCI). It has recently become clear that SCI might increase susceptibility to infec­tion by central nervous system (CNS)-specific mechanisms: CNS injury induces a disrup­tion of the normally well-balanced interplay between the immune system and the CNS. As a result, SCI also leads to secondary im­munodeficiency (SCI injury-induced immu­nodepression, SCI-IDS) and infection. SCI-IDS (a) starts early after SCI (within 24 h), (b) af­fects both the innate and adaptive immune system, and (c) is independent of iatrogenic application of high-dose corticosteroids. The fact that increased immunosuppression cor­relates with lesion level underlines a neurogenic origin. Here we summarize the current understanding and main pathophysiological features of leukocyte dysfunction following SCI. A better understanding of this syndrome may provide insights into how the CNS controls the immune system. Furthermore, the identification of patients suffering from spi­nal cord injury as immunocompromised is a clinically relevant, yet widely underappreci­ated finding.
LINKING COMMUNITY-BASED SEED PRODUCERS TO MARKETS FOR A SUSTAINABLE SEED SUPPLY SYSTEM
Authors: WITCOMBE J. R. , DEVKOTA K. P. , JOSHI K. D. 
Published: September 2010

SUMMARYA review of the outcomes of past attempts at establishing sustainable seed producer groups in Nepal showed that after donor support was withdrawn a lack of marketing skills resulted in the groups no longer producing seed. Learning from this review, when we initiated new attempts at establishing sustainable seed producer groups in Chitwan district, Nepal, we emphasized the strengthening of their marketing and managerial capabilities rather than training in technical issues such as seed quality control. We imparted marketing skills to committee members of farmer groups at an initial training course in Chitwan in 2001. This inspired at least three existing farmer groups in Chitwan, already established for other agricultural activities, to enter into cereal and legume seed production and its marketing. Following their establishment in 2002 we supported them initially by purchasing some of their seed production. This was progressively withdrawn and, after three years, the groups independently marketed all of their substantial seed production. They built up capital reserves mainly from subsidies and by attracting funds from new shareholders with only a small contribution from retained profits that were only about 5% of total turnover. The capital reserves reduced or eliminated the need for loans thus increasing the chances that the enterprises would be sustainable. In contrast, other government-supported groups had practically no cash reserves despite substantial seed sales. By 2010, two of the three groups were still operating and had substantially increased turnover. Shareholders who were also seed producers benefited from being members of the group and from an increased income of 10% by producing seed instead of grain. Our intention in supporting these groups was to promote the scaling out of new rice varieties produced by client-oriented breeding (COB) or identified by participatory varietal selection but most of the seed that was produced was of obsolete varieties. Policies are needed to preferentially promote new varieties by supplying more information about them and increasing the subsidy on their seeds compared with older varieties. Continuing promotion by the organizations that bred them is also desirable but constrained by limited funding for COB.
Cholesteatoma imaging using modified echo-planar diffusion-weighted magnetic resonance imaging
Authors: Flook E , Izzat S , Ismail A 
Published: September 2010

AbstractIntroduction:Imaging of cholesteatomas can be useful especially in cases of recurrent disease. Computed tomography scans have been recommended before primary surgery, but cholesteatoma tissue looks similar to inflammatory tissue. Diffusion-weighted magnetic resonance imaging is both sensitive and specific in detecting cholesteatoma, which appears as a bright signal on a dark background. Non-echo-planar diffusion-weighted magnetic resonance imaging is superior to routine echo-planar diffusion-weighted magnetic resonance imaging as it minimises susceptibility artefacts; however, the addition of this facility involves expensive magnetic resonance scanner upgrading.Method:To avoid the cost of such upgrading, we modified our echo-planar diffusion-weighted magnetic resonance imaging parameters and then scanned 15 consecutive cases of suspected cholesteatoma or suspected recurrent cholesteatoma.Results:Imaging results correlated well with clinical and/or operative findings.Conclusion:These results indicate that software adjustments can enable echo-planar diffusion-weighted magnetic resonance imaging to detect cholesteatomas reliably, and as effectively as non-echo-planar diffusion-weighted magnetic resonance imaging. This discovery has the potential to facilitate reliable delayed post-operative screening of canal wall up mastoidectomies, avoiding the need for a ‘second look’ procedure.
A humanoid robot capable of carrying heavy objects
Authors: Choi Hyeung-Sik , Na Wonhyun , Kang Dongwan 
Published: September 2010

SUMMARYA new type of 28-DOF (degree of freedom) full-size humanoid robot, driven by a closed-chain type of joint actuation system, is developed in this paper. Each leg of the robot is composed of six joints, where three are at the hip, one is at the knee, and two are at the ankle. The robot has six joints for each arm, one balancing joint, and three joints for the head, with two cameras. The weight of the robot is 75 kg, and its height is 168 cm.The actuation systems of the pitching joint for the arms and legs of the robot are designed based on a closed-chain mechanism composed of four bar links driven by a ball screw, and each leg of the robot is designed to support 95 kg weight to include a 20 kg payload that can be carried by the robot arms having very light designs (with weight 8.5 kg), but each capable of carrying a 10 kg payload.An analysis of the closed-chain joint actuation systems of a light arm capable of handling heavy objects is performed, and the light arm is designed via finite-element method analysis performed using ANSYS. In addition, the kinematic analysis and the detailed structure of the arm and leg of the robot are performed.The main controller uses the ARM processor and a distributed controller for the leg joints is developed using the TMS320c2407 processor with the communications between the main and joint controllers being performed via the CAN system.Good performances of the proposed robot is demonstrated by presenting several experimental results; these include (1) experimentally handling a 13 kg payload, (2) through walking experiments of the robot supporting a 85 kg load, and (3) measurements of the arm and leg joint motors while performing walking experiments.
Efficiency of an agrosystem designed for family farming in the pre-Amazon region
Authors: Aguiar Alana das Chagas Ferreira , de Freitas Idelfonso Colares , Carvalho Cristina Silva , Marques Monroe Paulo Henrique , de Moura Emanoel Gomes 
Published: September 2010

AbstractIn the humid tropics, the continuous use of the same area reduces nutrient availability and increases the incidence of weeds. To circumvent these obstacles, farmers practice itinerant agriculture associated with slashing and burning with negative effects on the local and global environment. In search for a suitable system for humid tropical agriculture, the objective of this study was to investigate the performance of no-till alley cropping in conjunction with the use of annual legume crops grown during the off-season. The experiment was implemented in a one-hectare alley cropping system in which the leguminous tree clitoria (Clitoria fairchildiana R.A. Howard) was used. The experimental design consisted of randomized blocks with four replications of the following treatments: Stylosanthis (Stylosanthis capitata), showey rattlebox (Crotalaria spectabilis), sunn hemp (Crotalaria juncea), jack bean (Canavalia ensiformis) and a control with clitoria alone, without an annual legume. In January 2007 and 2008, maize was planted in each alley. One hundred and twenty days after annual legumes were sown, the total biomass was recorded. Weed incidence was assessed 35 days after maize planting. Analyses of the C, N, P, K, Ca and Mg contents of the legumes were carried out. To assess soil organic matter (SOM), composite soil samples from the surface 0–5 cm were collected from experimental plots. Two adjacent areas were also sampled for comparison: a 10-year-old secondary forest and an area of conventional tillage. The SOM was fractionated using a densitometric and a granulometric method. Conventional systems reduce the silt and free light organic matter fractions more than no till. The use of annual legumes changes the composition of the weed community, replacing the more aggressive types with those less competitive. The use of showy rattlebox (C. spectabilis) may be an effective strategy for reducing weed density in the long-season crop. Furthermore, relative to the use of leguminous trees alone, higher yields of maize can be obtained with the use of showy rattlebox (C. spectabilis) and sunn hemp (C. juncea) without the application of additional N.
The Commensal Real-Time ASKAP Fast-Transients (CRAFT) Survey
Authors: Macquart Jean-Pierre , Bailes M. , Bhat N. D. R. , Bower G. C. , Bunton J. D. , Chatterjee S. , Colegate T. , Cordes J. M. , D'Addario L. , Deller A. , Dodson R. , Fender R. , Haines K. , Hall P. , Harris C. , Hotan A. , Johnston S. , Jones D. L. , Keith M. , Koay J. Y. , Lazio T. J. W. , Majid W. , Murphy T. , Navarro R. , Phillips C. , Quinn P. , Preston R. A. , Stansby B. , Stairs I. , Stappers B. , Staveley-Smith L. , Tingay S. , Thompson D. , van Straten W. , Wagstaff K. , Warren M. , Wayth R. , Wen L. ,   The CRAFT Collaboration
Published: September 2010

AbstractWe are developing a purely commensal survey experiment for fast (<5 s) transient radio sources. Short-timescale transients are associated with the most energetic and brightest single events in the Universe. Our objective is to cover the enormous volume of transients parameter space made available by ASKAP, with an unprecedented combination of sensitivity and field of view. Fast timescale transients open new vistas on the physics of high brightness temperature emission, extreme states of matter and the physics of strong gravitational fields. In addition, the detection of extragalactic objects affords us an entirely new and extremely sensitive probe on the huge reservoir of baryons present in the IGM. We outline here our approach to the considerable challenge involved in detecting fast transients, particularly the development of hardware fast enough to dedisperse and search the ASKAP data stream at or near real-time rates. Through CRAFT, ASKAP will provide the testbed of many of the key technologies and survey modes proposed for high time resolution science with the SKA.
Probing electron transfer mechanisms in
Shewanella oneidensis
MR-1 using a nanoelectrode platform and single-cell imaging
Authors: Jiang Xiaocheng , Hu Jinsong , Fitzgerald Lisa A. , Biffinger Justin C. , Xie Ping , Ringeisen Bradley R. , Lieber Charles M. 
Published: September 2010

Microbial fuel cells (MFCs) represent a promising approach for sustainable energy production as they generate electricity directly from metabolism of organic substrates without the need for catalysts. However, the mechanisms of electron transfer between microbes and electrodes, which could ultimately limit power extraction, remain controversial. Here we demonstrate optically transparent nanoelectrodes as a platform to investigate extracellular electron transfer in
Shewanella oneidensis
MR-1, where an array of nanoholes precludes or single window allows for direct microbe-electrode contacts. Following addition of cells, short-circuit current measurements showed similar amplitude and temporal response for both electrode configurations, while in situ optical imaging demonstrates that the measured currents were uncorrelated with the cell number on the electrodes. High-resolution imaging showed the presence of thin, 4- to 5-nm diameter filaments emanating from cell bodies, although these filaments do not appear correlated with current generation. Both types of electrodes yielded similar currents at longer times in dense cell layers and exhibited a rapid drop in current upon removal of diffusible mediators. Reintroduction of the original cell-free media yielded a rapid increase in current to ∼80% of original level, whereas imaging showed that the positions of > 70% of cells remained unchanged during solution exchange. Together, these measurements show that electron transfer occurs predominantly by mediated mechanism in this model system. Last, simultaneous measurements of current and cell positions showed that cell motility and electron transfer were inversely correlated. The ability to control and image cell/electrode interactions down to the single-cell level provide a powerful approach for advancing our fundamental understanding of MFCs.
Measurement of collisional quenching rate of nitrogen states N2(C 3Πu, v = 0) and
Authors: Valk F , Aints M , Paris P , Plank T , Maksimov J , Tamm A 
Published: September 2010

This paper presents an experimental investigation of the effect of the electric field strength on the collisional quenching rate of nitrogen states N2(C
3Πu, v = 0) and
by nitrogen and oxygen molecules. In experiments, the pulses of non-self-sustained electrical discharge excite gas molecules. The range of reduced electric field strength is from 240 to 4000 Td at pressure range from 70 to 4300 Pa. The experiments show that the field strength has no effect on the quenching rate. The paper discusses the probable reasons for discrepancy of results obtained by different authors and proposes the preferable values for rate coefficients. These coefficients can be used for electric field determination in low temperature gas discharge plasmas via nitrogen emission spectrum, and are of interest to atmospheric air fluorescence investigations.