bluuebunny/crossref_metadata_2025_split huggingface dataset:
Desymmetrization of meso‐N‐Acylaziridines with Benzenethiols Promoted by α,α‐Diaryl‐L‐prolinols
Authors: Lattanzi Alessandra , Della Sala Giorgio 
Published: March 2009

Abstractα,α‐Diaryl‐L‐prolinols were disclosed to promote the desymmetrization of meso‐N‐acylaziridines with benzenethiols to afford the products in good yields and moderate enantioselectivities (up to 61 % ee), which can be greatly improved to >90 % ee after a single recrystallization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Homocoupling of Arylboronic Acids Catalyzed by 1,10‐Phenanthroline‐Ligated Copper Complexes in Air
Authors: Kirai Naohiro , Yamamoto Yoshihiko 
Published: March 2009

AbstractThe efficient homocoupling of arylboronic acids was achieved by using the catalytic combination of inexpensive copper salts and 1,10‐phenanthroline as a ligand. The homocoupling reaction proceeds at ambient temperature in air without any additives such as base or oxidant. This method tolerates various substituents on the arylboronic acids such as halogens, carbonyls, and a nitro group. As a result, 25 symmetrical biaryls were obtained from readily availablearylboronic acids in 19–92 % isolated yields. A binuclear (μ‐hydroxido)copper complex is assumed as the catalytically active species, which undergoes efficient transmetalation with arylboronic acids to produce dinuclear arylcopper complexes. The binuclear structure is assumed to be essential for the bimetallic reductive elimination of biaryls as well as the oxidative restoration of the catalyst.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
The structural behaviour of timber joints subjected to bi‐axial bending
Authors: Chang Wen‐Shao , Shanks Jonathan , Kitamori Akihisa , Komatsu Kohei 
Published: March 2009

AbstractThis study investigates the structural performance of interior, exterior and corner traditional timber joints found in a traditional temple in Japan subjected to bi‐axial bending. A total of 36 half‐scale specimens were fabricated and tested under both uni‐axial and bi‐axial cyclic bending for comparison of their structural behaviour. The results show that the corner joints exhibit lower rotational stiffness than the interior and exterior joints. Further, connections subjected to only uni‐axial moments exhibit better performance with regard to moment resistance, energy dissipation and stiffness degradation as compared with those subjected to bi‐axial moments. Hence, this study suggests that if the timber joints are subjected to bi‐axial bending, this effect on timber joints should be considered during the design and evaluation process in the future. Copyright © 2009 John Wiley & Sons, Ltd.
Hepatic recruitment of the inflammatory Gr1+ monocyte subset upon liver injury promotes hepatic fibrosis #
Authors: Karlmark Karlin Raja , Weiskirchen Ralf , Zimmermann Henning W. , Gassler Nikolaus , Ginhoux Florent , Weber Christian , Merad Miriam , Luedde Tom , Trautwein Christian , Tacke Frank 
Published: March 2009

Abstract
In addition to liver-resident Kupffer cells, infiltrating immune cells have recently been linked to the development of liver fibrosis. Blood monocytes are circulating precursors of tissue macrophages and can be divided into two functionally distinct subpopulations in mice: Gr1hi (Ly6Chi) and Gr1lo (Ly6Clo) monocytes. The role of these monocyte subsets in hepatic fibrosis and the mechanisms of their differential recruitment into the injured liver are unknown. We therefore characterized subpopulations of infiltrating monocytes in acute and chronic carbon tetrachloride (CCl4)-induced liver injury in mice using flow cytometry and immunohistochemistry. Inflammatory Gr1hi but not Gr1lo monocytes are massively recruited into the liver upon toxic injury constituting an up to 10-fold increase in CD11b+F4/80+ intrahepatic macrophages. Comparing wild-type with C-C chemokine receptor (CCR2)-deficient and CCR2/CCR6–deficient mice revealed that CCR2 critically controls intrahepatic Gr1hi monocyte accumulation by mediating their egress from bone marrow. During chronic liver damage, intrahepatic CD11b+F4/80+Gr1+ monocyte-derived cells differentiate preferentially into inducible nitric oxide synthase–producing macrophages exerting proinflammatory and profibrogenic actions, such as promoting hepatic stellate cell (HSC) activation, T helper 1–T cell differentiation and transforming growth factor β (TGF-β) release. Impaired monocyte subset recruitment in Ccr2
−/− and Ccr2
−/−
Ccr6
−/− mice results in reduced HSC activation and diminished liver fibrosis. Moreover, adoptively transferred Gr1hi monocytes traffic into the injured liver and promote fibrosis progression in wild-type and Ccr2
−/−
Ccr6
−/− mice, which are otherwise protected from hepatic fibrosis. Intrahepatic CD11b+F4/80+Gr1+ monocyte-derived macrophages purified from CCl4-treated animals, but not naïve bone marrow monocytes or control lymphocytes, directly activate HSCs in a TGF-β–dependent manner in vitro. Conclusion: Inflammatory Gr1+ monocytes, recruited into the injured liver via CCR2-dependent bone marrow egress, promote the progression of liver fibrosis. Thus, they may represent an interesting novel target for antifibrotic strategies. (Hepatology 2009;50:261–274.)
Redundancy of the effect of TGFβ1 and β‐NGF on the second meiotic division of rat spermatocytes
Authors: Perrard Marie‐Hélène , Durand Philippe 
Published: March 2009

AbstractWe have previously shown that in cocultures of late pachytene/diplotene spermatocytes (PS/DS) with Sertoli cells, β‐nerve growth factor (β‐NGF) or transforming growth factor (TGFβ1) regulates the second meiotic division by blocking secondary spermatocytes in metaphase II, and thereby lowers round spermatid formation. In this study, we raised the question if β‐NGF and TGFβ1 have additional or redundant effects on this step. Hence, we addressed the effect of β‐NGF in combination with TGFβ1, as compared to those of β‐NGF or TGFβ1 separately, on the completion of meiosis by rat late PS/DS. Identification and counting of meiotic cells were performed by cytological methods. Under our culture conditions, some late PS/DS differentiated into round spermatids. When β‐NGF in combination with TGFβ1 was added to the culture medium, the numbers of PS/DS and of secondary spermatocytes were not modified by the treatment. By contrast, the number of round spermatids was about 2‐fold lower in treated cultures than in basal cultures, and an increase in metaphase II, but not metaphase I, over basal values was observed. Similar results were found when either β‐NGF or TGFβ1 was added to the culture medium. These results indicate a redundancy between β‐NGF and TGFβ1 on the negative regulation of the second meiotic division of rat spermatocytes. This suggests that β‐NGF and TGFβ1 share some common pathway of regulation of this step. In addition, these results reinforce the view that the adjustment of the number of round spermatids supported by Sertoli cells is a key event of the spermatogenic process. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.
An efficient and facile synthesis of pyrimidine and quinazoline derivatives via one‐pot three‐component reaction under solvent‐free conditions
Authors: Rong Liangce , Han Hongxia , Wang Haiying , Jiang Hong , Tu Shuajiang , Shi Daqing 
Published: March 2009

Abstract
magnified imageAn efficient and convenient method for the preparation of pyrimidine and quinazoline derivatives by the one‐pot reaction of aromatic aldehydes, cyclic ketones and guanidine carbonate, in the presence of sodium hydroxide under solvent‐free condition was reported. This method has the advantages of excellent yields, mild reaction conditions, easy work‐up, and being environmentally friendly over the existing procedures. J. Heterocyclic Chem., (2009).
γ‐Radiolysis of 2′‐deoxy‐5‐fluorouridine derivatives with sulfur‐containing substituents
Authors: Kuroda Tokuyuki , Hisamura Koji , Nakamizo Nobuhiro , Otsuji Yoshio 
Published: March 2009

Abstract2′‐Deoxy‐5‐fluorouridine (5‐FUdR) derivatives having various types of sulfur‐containing substituents at the 5′‐O‐position were synthesized and their γ‐radiolyses were studied in aqueous solutions. The γ‐radiolysis of compounds having 1,3‐dithiol‐2‐yl and 1,3‐dithian‐2‐yl substituents at the 5′‐O‐position efficiently gave 5‐FUdR, specifically via the attack of hydroxyl radical. On the other hand, the γ‐radiolysis of a compound having a sulfonylmethyl substituent at the 5′‐O‐position gave less efficiently 5‐FUdR, specifically via the attack of the hydrated electron. The mechanistic features of these reactions are discussed.
Complete 1H and 13C NMR spectral characterization of 1,6‐dioxapyrene and related compounds. An unusual coupling interaction through hydrogen bond in three precursors
Authors: Platzer N. , Buisson J.‐P. , Demerseman P. 
Published: March 2009

AbstractThe 1H and 13C nmr studies of 1,6‐dioxapyrene show the disruption of extended delocalization of the π electrons in this recently synthesized heterocyclic skeleton. A surprising coupling interaction through hydrogen bonding was detected in the precursors bearing formyl and hydroxyl groups in peri positions.
Methyl substituent effects for methyltryptophans in 13C nmr
Authors: Lee Minsu , Phillips Robert S. 
Published: March 2009

AbstractThe 13C and 1H nmr spectra of methyltryptophans 2–5 in 0.1 N sodium deuteroxide methanol‐d4 were assigned based on 1‐D and 2‐D nmr techniques, including COSY, inverse‐detected direct (HMQC) and long‐range (HMBC) correlation. Methyl substituent effects in chemical shifts (SCS) for the indole ring of tryptophan were calculated and compared with those of indole. The correlations were linear except for 4‐methyltryptophan, which suggest structural changes in the indole ring of 4‐methyltryptophan and 4‐methylindole. The results of molecular modeling and NOE experiments supported that suggestion.
On triazoles. XXVII. The acylation, carbamoylation and thiocarbamoylation of tetrahydropyrido[4,3‐d][1,2,4]triazolo[1,5‐a]pyrimidinones
Authors: Rivó Endre , Reiter József 
Published: March 2009

AbstractIsomeric 6,7,8,9‐tetrahydropyrido[4,3‐d][1,2,4]triazolo[1,5‐a]pyrimidine‐5(10H)‐ones 3, and ‐6(10H)‐ones 4 were synthesised. Isomers 3 were converted to their 7‐acyl 7, 7‐carbamoyl 8 and 7‐thiocarbamoyl 9 derivatives.
Ring‐chain‐transformations : Synthesis of ω‐functionalized alkylthio‐1,2,4‐triazoles by reaction of cyclic S‐analogous N‐cyano or N‐aroylcarbonimidoesters with hydrazines
Authors: Pätzel Michael , Schulz Andreas , Liebscher Jürgen , Richter Wolfgang , Richter Monika 
Published: March 2009

AbstractCyclic N‐cyanocarbonimidodithioesters 4 or N‐aroylcarbonimidothioic acid esters 10 react regioselectively with arylhydrazines and methylhydrazine by a ring chain transformation reaction forming ω‐functionalized 3‐alkylthio‐1,2,4‐triazoles 8 and 11 or 5‐alkylthio‐1,2,4‐triazoles 9.
A direct synthesis of indolocarbazoles via new dinitroterphenyl precursors
Authors: Kistenmacher Axel , Müllen Klaus 
Published: March 2009

AbstractThe two indolocarbazoles 2 and 4 were synthesized via the reductive ring closure of dinitrodiphenylbenzenes with triethylphosphite as reducing agent in a high boiling solvent. The electrochemical behaviour of the title systems is discussed.
Kinetic study on the anelation of heterocycles. 3. Pyrazino[2,3‐d]pyrimidine derivatives synthesized by the hinsberg reaction
Authors: Abasolo Maria Inés , Fernández Beatriz M. , Magrini Edgardo 
Published: March 2009

AbstractA kinetic study on the obtainment of pyrazinopyrimidine derivatives (pteridines) was performed. The regioselective synthesis of compounds 6‐methylpyrazino[2,3‐d]pyrimidin‐7(8H)‐one (5a) and 7‐methylpyraz‐ino[2,3‐d]pyrimidin‐6(5H)‐one (5b), in good yields, was expected by the Hinsberg reaction because the synthesis of both isomers analytically pure was never reported to date. This Hinsberg reaction gave good results to obtain compound 5a, regioselectively and in good yields, either in pH 5 aqueous buffer solution or in methylene chloride, among several organic solvents. However, structural and solvation factors prevented the synthesis of the isomer 5b, which was regioselectively formed in very acid solutions (Ho  −0.89), but in very poor yield.
Studies on pyrrolidones. Synthesis and N‐alkylation of β‐enaminoesters derived from pyroglutamic acid
Authors: Fasseur Dominique , Rigo Benoît , Leduc Catherine , Cauliez Pascal , Couturier Daniel 
Published: March 2009

AbstractThe condensation of iminoether 7, derived from pyroglutamic acid (4), with active methylene reagents such as Meldrum's acid or methyl cyanoacetate, lead to β‐enaminoesters 2. Solid‐liquid phase transfer N‐alkylation of these compounds is described.
Natural product chemistry. Part 153 . Synthesis and possible anticancer activity of 8‐nitronoracronycine
Authors: Reisch Johannes , Dziemba Peter 
Published: March 2009

AbstractSince the strategy for the synthesis of 9‐, 10‐ and 11‐nitronoracronycine [3,4] could not be applied to the 8‐nitronoracronycine 9, we here report the preparation of the latter by a fusion of methyl 2‐amino‐6‐nitrobenzoate 2 and phloroglucinol 3. The fusion of 2 and 3 gave 1,3‐dihydroxy‐8‐nitro‐9(10H)‐acridinone 6. Subsequent methylation, demethylation and reaction with 2‐chloro‐2‐methyl‐3‐butyne afforded the desired 8‐nitronoracronycine 9. Compound 9, 1,3‐dimethoxy‐10‐methyl‐8‐nitro‐9(10H)‐acridinone 7 and 1,3‐dihydroxy‐10‐methyl‐8‐nitro‐9(10H)‐acridinone 8 were tested by the National Cancer Institute (NCI) for possible anticancer activity.
Addition‐rearrangement reactions of 5‐imino‐Δ3‐1,2,4‐thiadiazolines with trichloroacetonitrile
Authors: L'Abbé Gerrit , Albrecht Ernestine , Toppet Suzanne 
Published: March 2009

AbstractThe reactions of 2‐alkyl‐3‐phenyl‐Δ3‐1,2,4‐thiadiazolin‐5‐imines 5a,b with trichloroacetonitrile at room temperature yield rearranged products, which are shown by 1H and 13C nmr spectroscopy to exist in two tautomeric structures 6 and 7.
Synthesis of mesoionic triazolo[4,3‐a]quinoxalines
Authors: Kurasawa Yoshihisa , Kawano Tae , Katoh Ritsuko , Takada Atsushi , Kim Ho Sik , Okamoto Yoshihisa 
Published: March 2009

AbstractThe reaction of 6‐chloro‐2‐(1‐methylhydrazino)quinoxaline 4‐oxide 1 or 6‐chloro‐2‐(1‐methylhydrazino)‐quinoxaline 5 with phenyl isothiocyanate under reflux in N,N‐dimethylformamide gave 7‐chloro‐3‐methyl‐1,2,4‐triazolo[4,3‐a]quinoxalin‐3‐ium‐1‐thioate 4, which was also obtained by refluxing of 6‐chloro‐2‐[1‐methyl‐2‐(N‐phenylthiocarbamoyl)hydrazino]quinoxaline 4‐oxide 2b or 6‐chloro‐2‐[1‐methyl‐2‐(N‐phenylthiocarbamoyl)hydrazino]quinoxaline 6 in N,N‐dimethylformamide.
Acid catalyzed rearrangements in the arylimino indoline series. Part IV. Reactions of 1,2‐dihydro‐2‐phenyl‐2‐(indol‐3‐yl‐derivatives)‐3‐phenylimino‐3H‐indole with trichloroacetic and hydrochloric acids. Crystal structure of 1,2‐dihydro‐2‐phenyl‐2‐(indol‐3‐yl)‐3‐phenylimino‐3H‐indole
Authors: Cardillo Barbara , Conti Carla , Giorgini Elisabetta , Greci Lucedio , Stipa Pierluigi , Tosi Giorgio , Rizzoli Corrado , Sgarabotto Paolo , Ugozzoli Franco 
Published: March 2009

Abstract2‐Phenyl‐3‐phenylimino‐3H‐indole reacts with indole, 2‐methylindole and 1,2‐dimethylindole in the presence of stoichiometric trichloroacetic acid to form 1,2‐dihydro‐2‐phenyl‐2‐(indol‐3‐yl‐derivatives)‐3‐phenylimino‐3H‐indole, which during a longer period of time (16 hours) undergoes indolyl transposition to carbon‐3 and elimination of aniline affording the 3,3′‐bis‐indolyls. In the case of 1,2‐dimethylindole the intermediate coming from the indolyl migration may undergo a nucleophilic addition to carbon‐2 of another molecule of indole; the new intermediate leads to the formation of 2‐phenyl‐3,3′‐di‐(1,2‐dimethylindol‐3‐yl)‐3H‐indole by elimination of aniline and migration to carbon‐3 of the second molecule of indole. By treatment with hydrochloric acid in refluxing ethanol, 1,2‐dihydro‐2‐phenyl‐2‐(indol‐3‐yl‐derivatives)‐3‐phenylimino‐3H‐indole afford to 3,3′‐bis‐indolyls and 1,2‐dihydro‐2‐phenyl‐2‐(indol‐3‐yl‐derivatives)‐3H‐indol‐3‐one (indoxyls). The crystal structure of 1,2‐dihydro‐2‐phenyl‐2‐(indol‐3‐yl)‐3‐phenylimino‐3H‐indole is also reported. The latter compound does not give rearrangement products by acid treatment, only untreatable tarry material.
Difunctional heterocycles: A convenient one pot synthesis of novel bis(benzoxazoles) from bis(o‐aminophenols)
Authors: Jois Yajnanarayana H. R. , Gibson Harry W. 
Published: March 2009

AbstractNew bis(benzoxazoles) 14 and 17 have been synthesized in excellent yields from the corresponding bis(o‐aminophenols) by refluxing with triethyl orthoformate. 6,6′‐Bis(benzoxazole) (14) has also been prepared utilizing Gold's reagent. Compound 14 is inert to Reissert reaction conditions. However, the Reissert reaction on 5,5′‐bis(benzoxazole) (17) led to ring opened product 20.
Development of transient head cavities during early organogenesis of the Nile Crocodile (Crocodylus niloticus)
Authors: Kundrát Martin , Janáček Jiří , Martin Samuel 
Published: March 2009

AbstractThree consecutive pairs of head cavities (premandibular, mandibular, and hyoid) found in elasmobranchs have been considered as remnants of preotic ‘head’ somites—serial homologues of the myotomic compartments of trunk somites that give rise to the extraoccular musculature. Here, we study a more derived vertebrate, and show that cavitation is more complex in the head of Crocodylus niloticus, than just the occurrence of three pairs of cavities. Apart from the premandibular cavities, paired satellite microcavities, and unpaired extrapremandibular microcavities are recognized in the prechordal region as well. We observed that several developmental phenomena occur at the same time as the formation of the head cavities (premandibular, satellite, extrapremandibular, mandibular, and hyoid) appear temporarily in the crocodile embryo. These are 1) rapid growth of the optic stalk and inflation of the optic vesicle; 2) release of the intimate topographical relationships between the neural tube, notochord and oral gut; 3) tendency of the prechordal mesenchyme to follow the curvature of the forebrain; and 4) proliferation of the prechordal mesenchyme. On the basis of volumetric characters, only the hyoid cavity and hyoid condensation is comparable to the trunk somitocoel and somite, respectively. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.
Effect of the climate shift around mid 1970s on the relationship between wintertime Ural blocking circulation and East Asian climate
Authors: Wang Lin , Chen Wen , Zhou Wen , Chan Johnny C. L. , Barriopedro David , Huang Ronghui 
Published: March 2009

AbstractBlocking variability over the Ural Mountain region in the boreal winter and its relationship with the East Asian winter climate is investigated. The climate shift around mid 1970s has been shown to exert a significant influence on the blocking pattern. In contrast with the years before 1976/1977, the Ural blocking signal after 1976/1977 is found to propagate less into the stratosphere and more eastward in the troposphere to East Asia, which therefore exerts more influence on the East Asian winter climate. This enhanced Ural blocking–East Asian climate relationship amplifies the impact of Ural blocking on East Asia and, with the background of decreasing Ural blocking, contributes to the higher frequency of warm winters in this region. Further analyses suggest that the NAM‐related stratospheric polar vortex strength and its modulation on the propagation of atmospheric stationary waves can account for this change, with the key area being located in the North Atlantic region. Copyright © 2009 Royal Meteorological Society
Nonstationary models for exploring and mapping monthly precipitation in the United Kingdom
Authors: Lloyd C. D. 
Published: March 2009

AbstractSpatial statistical algorithms are used widely for both the exploration and mapping of environmental variables such as precipitation amount. One limitation of standard approaches to characterization and spatial interpolation is the usual assumption of stationarity. In short, spatial variation is assumed to be constant across the region of interest. Much research effort has been extended in developing approaches that allow for local variation in spatial structure. Simple moving window approaches are examples of such developments. The purpose of this paper is to apply selected methods for exploring and mapping monthly precipitation amount in the UK. Global regression, moving window regression (MWR) and geographically weighted regression (GWR) are used to explore the relationship between altitude and precipitation amount. Inverse distance weighting (IDW) is used as a basic approach to spatial prediction. Global and local variogram models are estimated and modelled to assess variation in spatial structure of precipitation amount and to inform spatial prediction using ordinary kriging (OK), kriging with an external drift (KED) and simple kriging with local means (SKlm). In the latter case, local means are derived using global regression, MWR (using ordinary least squares (OLS) and generalized least squares (GLS)) and GWR. The importance of choice of algorithm for the estimation of the variogram and for spatial prediction is assessed. The benefits of local as against global approaches and multivariate as against univariate prediction procedures are considered. It is demonstrated that use of elevation data to inform the prediction process reduces prediction errors and that there is also a small reduction in prediction errors when local variogram models are used. In this study, KED based on local variogram models provides more accurate predictions (as judged by cross‐validation statistics) than any other approach. The paper concludes by considering some key issues and possible avenues for future work. Copyright © 2009 Royal Meteorological Society
Mulberry nutrient management for silk production in Hubei Province of China
Authors: Chen Fang , Lu Jianwei , Zhang Mingchu , Wan Kaiyuan , Liu Dongbi 
Published: March 2009

AbstractThe silk industry is important for south China's rural economy. Leaves of mulberry (Morus spp.) are used for silkworm production. Hubei province is one of the main silk‐producing provinces in China. The objectives of this research were to survey the fertilization practices in the mulberry‐producing regions in the province and to determine the best nutrition‐management practice for mulberry plantations. A survey and a series of field experiments with N, P, K, and micronutrients were conducted from 2001 to 2002. In addition, a silkworm‐growth experiment was also conducted by feeding leaves harvested from various fertilization treatments. The results indicate that poor soil fertility and unbalanced fertilization were the main factors limiting mulberry‐leaf yield and quality in Hubei province. Nitrogen fertilization of mulberry has reached a high level (454 kg ha–1 y–1) in Hubei province, but P‐ and K‐fertilization rates have not been matched with N‐fertilization rates as farmers are not aware of the significance of P and K. Balanced fertilization showed positive nutrient interactions with respect to mulberry yield and quality. Potassium application increased yield and quality (protein and sugar concentration) of mulberry leaves. Silkworm growth and cocoon quality were improved when silkworms were fed with the leaves derived from K‐fertilized plants in comparison with those taken from control plots. Application of Mg, S, and B also significantly improved leaf sugar, essential and total amino acid concentrations, but did not increase leaf yield significantly. It is concluded that a fertilizer dose of 375 kg N ha–1, 66 kg P ha–1, and 125 kg K ha–1 is suitable for the cultivation of mulberry in the Hubei province along with Mg, S, and B, wherever necessary, for the improvement of yield and quality of mulberry leaves.