bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of injury‐induced glial aromatase reveals a wave of secondary degeneration in the songbird brain
Authors: Wynne Ryan D. , Walters Bradley J. , Bailey David J. , Saldanha Colin J. 
Published: October 2007

AbstractMechanical or anoxic/ischemic brain insult results in reactive gliosis and a pronounced wave of apoptotic secondary degeneration (WSD). Reactive glia express aromatase (estrogen synthase) and glial estrogen synthesis decreases apoptosis and the volume of degeneration. Whether aromatization by glia affects gliosis itself or the initiation/maintenance of the WSD remains unknown. Adult male zebra finches (Taeniopygia guttata) were injured with a needle that contained the aromatase inhibitor fadrozole or vehicle into contralateral hemispheres. Birds were killed at 0, 2, 6, 24, 72h, 2 or 6 weeks postinjury. Gliosis and degeneration were measured with vimentin‐ and Fluoro‐Jade B‐expression, respectively. Reactive gliosis was detectable at 6 h, reached asymptote at 72 h, and continued until 6 weeks postinsult. Gliosis extended further around fadrozole‐injury than vehicle, an effect driven by a larger area of gliosis around fadrozole‐ relative to vehicle‐injury at 72 h postinsult. Glial aromatase was inhibited for about 2 weeks postinjury since aromatase relative optical density was higher around fadrozole‐injury relative to vehicle‐injury until this time‐point. Degeneration around vehicle‐injury reached asymptote at 2 h postinsult, but that around fadrozole‐injury peaked 24–72 h postinjury and decreased thereafter. Thus, the injury‐induced WSD as described in mammals is detectable in zebra finches only following glial aromatase inhibition. In the zebra finch, injury‐induced estrogen provision may decrease reactive gliosis and severely dampen the WSD, suggesting that songbirds are powerful models for understanding the role of glial aromatization in secondary brain damage. © 2007 Wiley‐Liss, Inc.
Selenium‐Containing Heterocycles from Isoselenocyanates: Base‐Catalyzed Reaction of Malononitrile with Phenyl Isoselenocyanate and Bromoacetonitrile or α‐Halogenated Ketones
Authors: Sommen Geoffroy L. , Linden Anthony , Heimgartner Heinz 
Published: October 2007

AbstractThe reaction of phenyl isoselenocyanate (1a) with malononitrile (=propanedinitrile) in DMF in the presence of Et3N leads to the intermediate ketene N,Se‐hemiacetal 6a, which can be trapped with bromoacetonitrile or α‐halogenated ketones 12a and 12b (Scheme 3). The products are [(alkylseleno)(phenylamino)methylene]malononitriles 10 and 13, which are obtained in good yield. In the case of the (2‐oxoalkyl)seleno derivatives 13, they are in equilibrium with the cyclic hemiacetals 14. Chemical and spectroscopic evidence for the structures of the new compounds are described. The structure of 14a was established by X‐ray crystallography.
Affinity and Reaction Rates: Reconsideration of Experimental Data
Authors: Pekař Miloslav 
Published: October 2007

AbstractTwo published experimental confirmations of either the linear relationship between the reaction rate and its affinity, or the ‘thermodynamic coupling’ are revised. It is shown that ‘proved’ results are more consequences of a given experimental arrangement or of methods used for the treatment of experimental concentration data than outcomes of some general thermodynamic law. The affinity should be considered not as a quantity determining the value of the reaction rate but as an alternative quantity for description of the evolution of a reacting system, its distance from equilibrium. The affinity, perhaps, expresses some potential for a reaction, but its manifestation in the reaction rate is controlled by the very kinetics.
Synthesis, Structure, and Conformation of 2′,3′‐Fused Oxathiane and Thiomorpholine Uridines
Authors: Sun Jingbo , Wu Jinchang , Yang Hua 
Published: October 2007

AbstractThe syntheses of two 2′,3′‐fused bicyclic nucleoside analogues, i.e., 1‐[(4aR,5R,7R,7aS)‐hexahydro‐5‐(hydroxymethyl)‐4,4‐dioxidofuro[3,4‐b][1,4]oxathiin‐7‐yl]pyrimidine‐2,4(1H,3H)‐dione (1a) and 1‐[(4aS,5R,7R,7aS)‐hexahydro‐7‐(hydroxymethyl)‐1,1‐dioxido‐2H‐furo[3,4‐b][1,4]thiazin‐5‐yl]pyrimidine‐ 2,4(1H,3H)‐dione (1b), are described, the key step being an intramolecular hetero‐Michael addition. Their structures and conformations, previously solved by X‐ray crystallography, were analyzed in more detail, using 1D‐ and 2D‐NMR as well as HR‐MS analyses.
Synthesis and Structure of O,O‐Diethyl N‐[(trans‐4‐Aryl‐5,5‐dimethyl‐2‐oxido‐2λ5‐1,3,2‐dioxaphosphorinan‐2‐yl)methyl]phosphoramidothioates
Authors: Miao Zhiwei , Zhang Jianfeng , Cui Zhanwei , Wang Bin , Chen Ruyu 
Published: October 2007

AbstractA study on the synthesis of the novel N‐(cyclic phosphonate)‐substituted phosphoramidothioates, i.e., O,O‐diethyl N‐[(trans‐4‐aryl‐5,5‐dimethyl‐2‐oxido‐2λ5‐1,3,2‐dioxaphosphorinan‐2‐yl)methyl]phosphoramidothioates 4a–l, from O,O‐diethyl phosphoramidothioate (1), a benzaldehyde or ketone 2, and a 1,3,2‐dioxaphosphorinane 2‐oxide 3 was carried out (Scheme 1 and Table 1). Some of their stereoisomers were isolated, and their structure was established. The presence of acetyl chloride was essential for this reaction and accelerated the process of intramolecular dehydration of intermediate 5 forming the corresponding Schiff base 7 (Scheme 2).
Enzymatic Resolution of O‐(Methoxymethyl)‐Protected Tropane‐diols
Authors: Affolter Olena , Baro Angelika , Laschat Sabine , Fischer Peter 
Published: October 2007

AbstractA convenient synthetic route to enantiomerically pure tropane‐diol building blocks is described. The reaction sequence started from tropenone derivatives 1, which were dihydroxylated to give 6,7‐dihydroxytropanone derivatives 2. After introduction of the methoxymethyl (MOM) protecting group in diol 2a, a lipase‐mediated resolution of the resulting racemic mono‐MOM ether (±)‐5d with vinyl acetate and vinyl trifluoroacetate gave the acetates (−)‐6d and (−)‐6f, respectively, with 96–99% ee, and MOM ether (+)‐5d with up to 89% ee. Deacetylation of (−)‐6d afforded quantitatively MOM ether (−)‐5d with 99% ee, the absolute configuration of which was assigned via the modified Mosher method to be (R) at C(6). Enzymatic treatment of unprotected diol 2a with vinyl trifluoroacetate or alkoxycarbonylation resulted in the formation of Cs‐symmetrical products 9 and 12 rather than the desired desymmetrized derivatives.
Direct Amination of meso‐Tetraarylporphyrin Derivatives – Easy Route to A3B‐, A2BC‐, and A2B2‐Type Porphyrins Bearing Two Nitrogen‐Containing Substituents at the meso‐Positioned Phenyl Groups
Authors: Ostrowski Stanisław , Grzyb Sebastian , Mikus Agnieszka 
Published: October 2007

Abstractmeso‐Tetraarylporphyrinato complexes 1a–g (ZnII, CuII, and NiII) bearing one or two nitro‐substituted aryl moieties react with 1,1,1‐trimethylhydrazinium iodide in the presence of tBuOK in THF at 0–5° or in the presence of KOH in DMSO at 60–70° according to a nucleophilic substitution of an H‐atom, thus affording porphyrins 2a–g and 3f,g with amino‐functionalized meso‐positioned aryl substituents in yields up to 73% (Scheme 1 and Table). The products obtained are attractive intermediates for further derivatization of porphyrins and may be of potential use as sensitizers in photodynamic cancer therapy.
Generation, Spectroscopic Characterization by EPR, and Decay of a Pyranine‐Derived Radical
Authors: Aliaga Carolina , Arenas Andrea , Aspée Alexis , López‐Alarcón Camilo , Lissi Eduardo A. 
Published: October 2007

AbstractThe pyraninoxyl radical is readily formed from the MnO2‐promoted oxidation of pyranine. The free radical can be formed in high concentrations (mM), and presents a characteristic EPR spectrum that indicates a high spin‐density delocalization. It is relatively stable under nitrogen (half‐life ca. 50 min) but readily decays in presence of O2. In spite of its high stability, the radical readily reacts with antioxidants (phenols and ascorbic acid) with a partial recovery of the parent pyranine. High concentrations of the pyraninoxyl radical (ca. 9 μM) are present when pyranine is exposed to a free radical source (10 mM 2,2′‐azobis[2‐amidinopropane], 37°). The fact that these radicals readily react with antioxidants (ascorbic acid and caffeic acid) supports the proposal that protection by antioxidants of peroxyl radical‐promoted pyranine bleaching is mainly due to the occurrence of a repair mechanism.
Four New Podocarpane‐Type Trinorditerpenes from Aleurites moluccana
Authors: Liu Hai‐Yang , Li Shi‐Jin , Zhao Yi , Ni Wei , Hao Xiao‐Jiang , Li Jun‐Zhu , Hua Yan , Xie Bai‐Bo , Qing Chen , Chen Chang‐Xiang 
Published: October 2007

AbstractFour new podocarpane‐type trinorditerpenenes, (5β,10α)‐12,13‐dihydroxypodocarpa‐8,11,13‐trien‐3‐one (1), (5β,10α)‐12‐hydroxy‐13‐methoxypodocarpa‐8,11,13‐trien‐3‐one (2), (5β,10α)‐13‐hydroxy‐12‐methoxypodocarpa‐8,11,13‐trien‐3‐one (3), and (3α,5β,10α)‐13‐methoxypodocarpa‐8,11,13‐triene‐3,12‐diol (4), together with four known diterpenes, 12‐hydroxy‐13‐methylpodocarpa‐8,11,13‐trien‐3‐one (5), spruceanol (6), ent‐3α‐hydroxypimara‐8(14),15‐dien‐12‐one (7), and ent‐3β,14α‐hydroxypimara‐7,9(11),15‐triene‐12‐one (8), were isolated from the twigs and leaves of Aleurites moluccana. Their structures were elucidated by means of comprehensive spectroscopic analyses, including NMR and MS. Except 8, all compounds were evaluated for their cytotoxicity; compound 4 exhibited moderate inhibitory activity against Raji cells with an IC50 value of 4.24 μg/ml.
Reactions of Dimethoxycarbene with N‐Tosylated Imines
Authors: Mlostoń Grzegorz , Warkentin John , Linden Anthony , Heimgartner Heinz 
Published: October 2007

AbstractThe reactions of dimethoxycarbene (DMC; 2), which was generated in situ by thermal decomposition of 2,5‐dihydro‐2,2‐dimethoxy‐5,5‐dimethyl‐1,3,4‐oxadiazole (1), with N‐tosylated imines of xanthone and 2,3 : 6,7‐dibenzosuberenone, 3a and 3d, respectively, led to different adducts with rearranged skeletons. In the case of 3a, the 1 : 1 adduct 5 as well as the 2 : 1 adduct 6 were obtained (Scheme 2). The formation of both products can be explained by a migration of a MeO group of the DMC fragment in a zwitterionic intermediate. On the other hand, migration of a Me group of DMC is necessary for the formation of the two 1 : 1 adducts 13 and 14 of 2 and 3d (Scheme 5). The structures of all products have been established by X‐ray crystallography.
A Mild and Efficient Method for Chlorination of Baylis–Hillman Adducts Using PPh3/Cl3CCONH2
Authors: Das Biswanath , Chowdhury Nikhil , Damodar Kongara , Ravikanth Bommena 
Published: October 2007

AbstractA new and convenient stereoselective synthesis of (Z)‐2‐(chloromethyl)alk‐2‐enoates has been achieved from Baylis–Hillman adducts by treatment with PPh3/Cl3CCONH2 at room temperature. The synthesis can proceed under mild and acid‐free conditions to form the products in high yields.
Diterpenoids of Isodon macrophylla
Authors: Qin Song , Chen Si‐Han , Guo Yue‐Wei , Gu Yu‐Cheng 
Published: October 2007

AbstractTwo new ent‐abietane diterpenoids, macrophynin E (1) and macrophynin F (2), and a known related ent‐abietanoid (−)‐lambertic acid (3), together with four known ent‐kauranoids, were isolated from the roots and aerial parts of Isodon macrophylla, respectively. The structures of the new compounds were elucidated on the basis of spectroscopic‐data analysis and chemical correlations.
Changes in flow conveyance and implication for flood protection, Sava River, Zagreb
Authors: Bonacci Ognjen , Ljubenkov Igor 
Published: October 2007

AbstractA low‐lying part of the Croatian capital, Zagreb, is exposed to flood risk from the Sava River. The biggest flood to data, with catastrophic consequences, occurred on 26 November 1964. To protect Zagreb from the Sava River floods, a flood control system was built and set in operation at the end of 1978. The Sava River's flood response changed over time as a result of this constructed system, as well as other anthropogenic and natural influences. The series of maximum annual Sava River stages and discharges measured at the Zagreb gauging station from 1926 to 2004 were analysed. Hydrological methods were used in order to assess Zagreb safety from the Sava River floods in the new conditions. This paper detects changes in high water occurrence in the Sava River near Zagreb. Long‐term stages and linear trends in discharges were examined. A simple technique for the conversion of stages to actual river channel morphology conditions was used. The technique presented in this paper enabled the recalculation of flood probabilities. It is stressed that for a complete understanding of floods, an examination should include the study of parameters of both maximum stages and maximum discharges. Copyright © 2007 John Wiley & Sons, Ltd.
Development of a continuous soil moisture accounting procedure for curve number methodology and its behaviour with different evapotranspiration methods
Authors: Kannan N. , Santhi C. , Williams J. R. , Arnold J. G. 
Published: October 2007

AbstractThe curve number (CN) method is widely used for rainfall–runoff modelling in continuous hydrologic simulation models. A sound continuous soil moisture accounting procedure is necessary for models using the CN method. For shallow soils and soils with low storage, the existing methods have limitations in their ability to reproduce the observed runoff. Therefore, a simple one‐parameter model based on the Soil Conservation Society CN procedure is developed for use in continuous hydrologic simulation. The sensitivity of the model parameter to runoff predictions was also analysed. In addition, the behaviour of the procedure developed and the existing continuous soil moisture accounting procedure used in hydrologic models, in combination with Penman–Monteith and Hargreaves evapotranspiration (ET) methods was also analysed. The new CN methodology, its behaviour and the sensitivity of the depletion coefficient (model parameter) were tested in four United States Geological Survey defined eight‐digit watersheds in different water resources regions of the USA using the SWAT model. In addition to easy parameterization for calibration, the one‐parameter model developed performed adequately in predicting runoff. When tested for shallow soils, the parameter is found to be very sensitive to surface runoff and subsurface flow and less sensitive to ET. Copyright © 2007 John Wiley & Sons, Ltd.
Estimating snow distribution over a large area and its application for water resources
Authors: Kazama So , Izumi Hirokazu , Sarukkalige Priyantha Ranjan , Nasu Takayuki , Sawamoto Masaki 
Published: October 2007

AbstractThe spatial and temporal distribution of the snow water equivalent (SWE), snow density and snow depth were estimated by a method combining remote sensing technology and degree‐day techniques over a study area of 370 000 km2. The advantages of this simulation model are its simplicity and the availability of degree‐day parameters, which can be successively evaluated by referring to snow area maps created from satellite images. This simulation worked very well for estimating SWE and helped to separate the areas of thin snow cover from heavier snowfall. However, shallow snow in warm regions led to some misjudgments in the snow area maps because of the time lag between when the satellite image was acquired and the simulation itself. Vulnerable areas, where a large variation in the amount of snow affects people's life, could be identified from the differences between heavy and light snow years. This vulnerability stems from a predicted lack of irrigation water for rice production caused by future climate change. The model developed in this study has the potential to contribute to water management activities and decision‐making processes when considering necessary adaptations to future climate change. Copyright © 2007 John Wiley & Sons, Ltd.
Modelling hydrological response to different land‐use and climate change scenarios in the Zamu River basin of northwest China
Authors: Wang Sufen , Kang Shaozhong , Zhang Lu , Li Fusheng 
Published: October 2007

AbstractChanges in climate and land use can significantly influence the hydrological cycle and hence affect water resources. Understanding the impacts of climate and land‐use changes on streamflow can facilitate development of sustainable water resources strategies. This study investigates the flow variation of the Zamu River, an inland river in the arid area of northwest China, using the Soil and Water Assessment Tool distributed hydrological model. Three different land‐use and climate‐change scenarios were considered on the basis of measured climate data and land‐use cover, and then these data were input into the hydrological model. Based on the sensitivity analysis, model calibration and verification, the hydrological response to different land‐use and climate‐change scenarios was simulated. The results indicate that the runoff varied with different land‐use type, and the runoff of the mountain reaches of the catchment increased when grassland area increased and forestland decreased. The simulated runoff increased with increased precipitation, but the mean temperature increase decreased the runoff under the same precipitation condition. Application of grey correlation analysis showed that precipitation and temperature play a critical role in the runoff of the Zamu River basin. Sensitivity analysis of runoff to precipitation and temperature by considering the 1990s land use and climate conditions was also undertaken. Copyright © 2007 John Wiley & Sons, Ltd.
Simulating the surface waters of the Amazon River basin: impacts of new river geomorphic and flow parameterizations
Authors: Coe Michael T. , Costa Marcos H. , Howard Erica A. 
Published: October 2007

AbstractThis paper describes the impacts of new river geomorphic and flow parameterizations on the simulated surface waters dynamics of the Amazon River basin. Three major improvements to a hydrologic model are presented: (1) the river flow velocity equation is expanded to be dependent on river sinuosity and friction in addition to gradient forces; (2) equations defining the morphological characteristics of the river, such as river height, width and bankfull volume, are derived from 31 622 measurements of river morphology and applied within the model; (3) 1 km resolution topographic data from the Shuttle Radar Topography Mission (SRTM) are used to provide physically based fractional flooding of grid cells from a statistical representation of sub‐grid‐scale floodplain morphology. The discharge and floodplain inundation of the Amazon River is simulated for the period 1968–1998, validated against observations, and compared with results from a previous version of the model. These modifications result in considerable improvement in the simulations of the hydrological features of the Amazon River system. The major impact is that the average wet‐season flooded area on the Amazon mainstem for the period 1983–1988 is now within 5% of satellite‐derived estimates of flooded area, whereas the previous model overestimates the flooded area by about 80%. The improvements are a consequence of the new empirical river geomorphologic functions and the SRTM topography. The new formulation of the flow velocity equation results in increased river velocity on the mainstem and major tributaries and a better correlation between the mean monthly simulated and observed discharge. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of infiltration of 2D trickle irrigation under multiple‐line sources
Authors: Chen Jiann‐Mou , Tan Yih‐Chi , Wu Yu‐Zhang 
Published: October 2007

AbstractThe analysis of infiltration of 2D trickle irrigation under multiple‐line sources, governed by the celebrated Richards equation, is performed, aiming at determining the efficiency of trickle irrigation so as to reduce the water demand. A closed‐form solution is explicitly obtained by utilizing the Fourier integral transformation, and this serves as a means to compute the distribution of volumetric water content during trickle irrigation. Results for the infiltration of 2D trickle irrigation under single line and multiple‐line sources are presented, which illustrate the distribution of infiltration water that diffuses into the soil, and make it possible to calculate the period of time required for trickle irrigation for different plants. The results can be applied to verify complicated solutions from other numerical models. Copyright © 2007 John Wiley & Sons, Ltd.
Increased flexibility in base flow modelling using a power law transmissivity profile
Authors: Rupp David E. , Woods Ross A. 
Published: October 2007

AbstractThe hydrological catchment model known as TOPMODEL, in its original and most widely‐used form, assumed that subsurface transmissivity decreases exponentially as subsurface water storage decreases. It has been shown that this leads to recession curves of discharge Q that take the form − dQ/dt = aQb, where a is a constant and b = 2. In order to reproduce a wider range of recession, or base flow, behaviour, a power function for transmissivity was subsequently incorporated into TOPMODEL as an alternative to the exponential function. This was claimed to extend the realistic values of b to range from 1 to 2, inclusive. We show here that the power transmissivity function can also generate values of b > 2 without making unrealistic assumptions (beyond those arguably made in the original TOPMODEL), thus generating recession curves consistent with catchments showing prolonged base flow. Furthermore, the power transmissivity function can generate recession curves that steepen with time (b < 1). Copyright © 2007 John Wiley & Sons, Ltd.
Changes in rainfall and relative humidity in river basins in northwest and central India
Authors: Singh Pratap , Kumar Vijay , Thomas T. , Arora Manohar 
Published: October 2007

AbstractSeasonal and annual trends of changes in rainfall, rainy days, heaviest rain and relative humidity have been studied over the last century for nine different river basins in northwest and central India. The majority of river basins have shown increasing trends both in annual rainfall and relative humidity. The magnitude of increased rainfall for considered river basins varied from 2–19% of mean per 100 years. The maximum increase in rainfall is observed in the Indus (lower) followed by the Tapi river basin. Seasonal analysis shows maximum increase in rainfall in the post‐monsoon season followed by the pre‐monsoon season. There were least variations in the monsoon rainfall during the last century and winter rainfall has shown a decreasing trend. Most of the river basins have experienced decreasing trends in annual rainy days with a maximum decrease in the Mahanadi basin. The heaviest rain of the year has increased from 9–27 mm per 100 years over different river basins with a maximum of 27 mm for the Brahamani and Subaranrekha river basins. A combination of increase in heaviest rainfall and reduction in the number of rainy days suggest the possibility of increasing severity of floods. Such information is useful in the planning, development and management of water resources in the study area. Further, the majority of river basins have also experienced an increasing trend in relative humidity both on seasonal and annual scales. An increase in annual mean relative humidity for six river basins has been found in the range of 1–18% of mean per 100 years, while a decrease for three river basins from − 1 to − 13% of mean per 100 years was observed, providing a net increase in the study area by 2·4% of mean per 100 years. It is understood that an increase in areal extent of vegetation cover as well as rainfall over the last century has increased the moisture in the atmosphere through enhanced evapotranspiration, which in turn has increased the relative humidity. Copyright © 2007 John Wiley & Sons, Ltd.