bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Histone2BCerulean BAC transgene identifies differential expression of Phox2b in migrating enteric neural crest derivatives and enteric glia
Authors: Corpening Jennifer C. , Cantrell V. Ashley , Deal Karen K. , Southard‐Smith E. Michelle 
Published: March 2008

AbstractThe mammalian enteric nervous system (ENS) derives from migratory enteric neural crest–derived cells (ENCC) that express the transcription factor Phox2b. Studies of these enteric progenitors have typically relied on immunohistochemical (IHC) detection. To circumvent complicating factors of IHC, we have generated a mouse BAC transgenic line that drives a Histone2BCerulean (H2BCFP) reporter from Phox2b regulatory regions. This construct does not alter the endogenous Phox2b locus and enables studies of normal neural crest (NC) derivatives. The Phox2b‐H2BCFP transgene expresses the H2BCFP reporter in patterns that recapitulate expression of endogenous Phox2b. Our studies reveal Phox2b expression in mature enteric glia at levels below that of enteric neurons. Moreover, we also observe differential expression of the transgene reporter within the leading ENCC that traverse the gut. Our findings indicate that the wavefront of migrating enteric progenitors is not homogeneous, and suggest these cells may be fate‐specified before expression of mature lineage markers appears. Developmental Dynamics 237:1119–1132, 2008. © 2008 Wiley‐Liss, Inc.
Expression of the Drosophila secreted cuticle protein 73 (dsc73) requires shavenbaby
Authors: Andrew Deborah J. , Baker Bruce S. 
Published: March 2008

AbstractLow stringency genomic library screens with genomic fragments from the sex determination gene doublesex identified the Drosophila
secreted
cuticle protein 73 (dsc73) gene, which encodes an 852‐residue protein with an N‐terminal signal sequence. In embryos, dsc73 RNA and protein are expressed to high levels in the epidermal cells that secrete the larval cuticle as well as in other cuticle‐secreting tissues such as the trachea and salivary duct. Embryonic expression of dsc73 requires Shavenbaby, a transcription factor regulating cuticle formation. Double‐labeling experiments with αCrb and αSAS reveal that, as with chitin and other known cuticle proteins, Dsc73 is secreted apically. Zygotic loss of dsc73 results in larval lethality but loss does not result in overt patterning defects or overt morphological defects in the embryonic tissues in which it is expressed. Thus, dsc73 encodes a novel secreted protein, and it is conserved within the Drosophila group. dsc73 may serve as a useful embryonic marker for cuticular patterning. Developmental Dynamics 237:1198–1206, 2008. © 2008 Wiley‐Liss, Inc.
Discovery of transcription factors and other candidate regulators of neural crest development
Authors: Adams Meghan S. , Gammill Laura S. , Bronner‐Fraser Marianne 
Published: March 2008

AbstractNeural crest cells migrate long distances and form divergent derivatives in vertebrate embryos. Despite previous efforts to identify genes up‐regulated in neural crest populations, transcription factors have proved to be elusive due to relatively low expression levels and often transient expression. We screened newly induced neural crest cells for early target genes with the aim of identifying transcriptional regulators and other developmentally important genes. This yielded numerous candidate regulators, including 14 transcription factors, many of which were not previously associated with neural crest development. Quantitative real‐time polymerase chain reaction confirmed up‐regulation of several transcription factors in newly induced neural crest populations in vitro. In a secondary screen by in situ hybridization, we verified the expression of >100 genes in the neural crest. We note that several of the transcription factors and other genes from the screen are expressed in other migratory cell populations and have been implicated in diverse forms of cancer. Development Dynamics 237:1021–1033, 2008. © 2008 Wiley‐Liss, Inc.
Influence of Hormones and Hormone Metabolites on the Growth of Schwann Cells Derived From Embryonic Stem Cells and on Tumor Cell Lines Expressing Variable Levels of Neurofibromin
Authors: Roth Therese M. , Ramamurthy Poornapriya , Muir David , Wallace Margaret R. , Zhu Yuan , Chang Lou , Barald Kate F. 
Published: March 2008

AbstractA benign human plexiform neurofibroma cell. Note the extensive tubulin networks (red), which become disrupted after addition of 2ME2, an estrogen metabolite implicated in tumor toxicity. The green staining represents S100 staining, indicating the Schwann Cell origin of the tumor cells. Blue is DAPI nuclear staining. See Roth et al., Developmental Dynamics 237:513–524, 2008. © 2008 Wiley‐Liss, Inc.
Synthetic Strategies for Oseltamivir Phosphate (Eur. J. Org. Chem. 11/2008)
Authors: Shibasaki Masakatsu , Kanai Motomu 
Published: March 2008

AbstractThe cover picture shows the chemical structure of oseltamivir phosphate (Tamiflu). Its representative starting materials and the asymmetric catalysts that provide its starting materials are also shown. Anybody can catch influenza. However, it is very scary, as it can be fatal. Oseltamivir phosphate is a potent antiinfluenza drug, that could protect humans from a possible influenza pandemic. The development of a synthetic route for oseltamivir phosphate that can satisfy its worldwide demand in a safe and environmentally friendly way is a great challenge today. In the Microreview by M. Shibasaki and M. Kanai on p. 1839 ff, synthetic strategies of oseltamivir are presented.
Hybrid and multi‐point formulations of the lowest‐order mixed methods for Darcy's flow on triangles
Authors: Younes Anis , Fontaine Vincent 
Published: March 2008

AbstractMixed finite element (MFE) and multipoint flux approximation (MPFA) methods have similar properties and are well suited for the resolution of Darcy's flow on anisotropic and heterogeneous domains.In this work, the link between hybrid and MPFA formulations is shown algebraically for the lowest order mixed methods of Raviart–Thomas (RT0) and Brezzi–Douglas–Marini (BDM1) on triangles. The efficiency of the four mixed formulations (Hybrid_RT0, MPFA_RT0, Hybrid_BDM1 and MPFA_BDM1) is investigated on high anisotropic and heterogeneous media and for unstructured triangular discretizations.Numerical experiments show that the MPFA_BDM1 formulation outperforms both Hybrid_RT0 and Hybrid_BDM1 in the case of anisotropic domains and highly unstructured meshes. Copyright © 2008 John Wiley & Sons, Ltd.
Differential parental transmission of markers in RUNX2 among cleft case‐parent trios from four populations
Authors: Sull Jae Woong , Liang Kung‐Yee , Hetmanski Jacqueline B. , Fallin Margaret Daniele , Ingersoll Roxann G. , Park Jiwan , Wu‐Chou Yah‐Huei , Chen Philip K. , Chong Samuel S. , Cheah Felicia , Yeow Vincent , Park Beyoung Yun , Jee Sun Ha , Jabs Ethylin Wang , Redett Richard , Jung Euiju , Ruczinski Ingo , Scott Alan F. , Beaty Terri H. 
Published: March 2008

AbstractIsolated cleft lip with or without cleft palate (CL/P) is among the most common human birth defects, with a prevalence around 1 in 700 live births. The Runt‐related transcription factor 2 (RUNX2) gene has been suggested as a candidate gene for CL/P based largely on mouse models; however, no human studies have focused on RUNX2 as a risk factor for CL/P. This study examines the association between markers in RUNX2 and isolated, nonsyndromic CL/P using a case‐parent trio design, while considering parent‐of‐origin effects. Case‐parent trios from four populations (77 from Maryland, 146 from Taiwan, 35 from Singapore, and 40 from Korea) were genotyped for 24 single nucleotide polymorphisms (SNPs) in the RUNX2 gene. We performed the transmission disequilibrium test on individual SNPs. Parent‐of‐origin effects were assessed using the transmission asymmetry test and the parent‐of‐origin likelihood ratio test (PO‐LRT). When all trios were combined, the transmission asymmetry test revealed a block of 11 SNPs showing excess maternal transmission significant at the P<0.01 level, plus one SNP (rs1934328) showing excess paternal transmission (P=0.002). For the 11 SNPs showing excess maternal transmission, odds ratios of being transmitted to the case from the mother ranged between 3.00 and 4.00. The parent‐of‐origin likelihood ratio tests for equality of maternal and paternal transmission were significant for three individual SNPs (rs910586, rs2819861, and rs1934328). Thus, RUNX2 appears to influence risk of CL/P through a parent‐of‐origin effect with excess maternal transmission. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Photocycloaddition Reactions of 5,5‐Dimethyl‐3‐(3‐methylbut‐3‐en‐1‐ynyl)cyclohex‐2‐en‐1‐one
Authors: Inhülsen Inga , Kopf Jürgen , Margaretha Paul 
Published: March 2008

AbstractThe title cyclohexenone 1d undergoes photodimerization selectively at the exocyclic CC bond to give a 1 : 1 mixture of 1,2‐dialkynyl‐1,2‐dimethylcyclobutanes 6 and 7. On irradiation in the presence of 2,3‐dimethylbuta‐1,3‐diene, 1d affords bicyclo[8.4.0]tetradeca‐1,2,3,7‐tetraen‐11‐one 9. This – formal – (6+4)‐cycloadduct undergoes quantitative isomerization to 3‐cycloheptadienyl‐2,5,5‐trimethylcyclohex‐2‐enone 11 on treatment with basic silica gel.
Stability of 7,8‐Dihydropterins in Air‐Equilibrated Aqueous Solutions
Authors: Dántola M. Laura , Vignoni Mariana , Capparelli Alberto L. , Lorente Carolina , Thomas Andrés H. 
Published: March 2008

Abstract6‐Substituted 7,8‐dihydropterins (=2‐amino‐7,8‐dihydropteridin‐4(1H)‐ones) are heterocyclic compounds that occur in a wide range of living systems and participate in relevant biological functions. In air‐equilibrated aqueous solutions, these compounds react with dissolved O2 (autooxidation). The rates of these reactions as well as the products formed strongly depend on the chemical structure of the substituents. 7,8‐Dihydro‐6‐methylpterin and 7,8‐dihydro‐6,7‐dimethylpterin that bear electron‐donor groups as substituents are the most reactive derivatives and undergo oxidation of the pterin moiety to yield the corresponding oxidized derivatives (6‐methylpterin and 6,7‐dimethylpterin, resp.). The oxidations of 7,8‐dihydrobiopterin, 7,8‐dihydroneopterin, and 7,8‐dihydrofolic acid are slower, and they yield 7,8‐dihydroxanthopterin as the main product. 7,8‐Dihydroxanthopterin, 6‐formyl‐7,8‐dihydropterin, and sepiapterin are rather stable, and their consumption in air‐equilibrated solutions is negligible for several days. The pseudo‐first‐order rate constants of the reactions between these compounds and O2 at 25° and 40° are reported. The biological implications of the results obtained are also discussed.
Diels–Alder Additions, Ene Reactions, and Condensations of 4‐(Acylamino)‐5‐nitrosopyrimidines – Synthesis of 8‐Substituted Guanines and of 6‐Substituted Pteridinones
Authors: Steinlin Thomas , Vasella Andrea 
Published: March 2008

Abstract4‐(Acylamino)‐5‐nitrosopyrimidines react either by a reductive condensation to provide 8‐substituted guanines, or by a Diels–Alder cycloaddition, or an ene reaction, to provide 6‐substituted pteridinones, depending on the nature of the acyl group and the reaction conditions. Experimental details are provided for the transformation of (acylamino)‐nitrosopyrimidines to 8‐substituted guanines, and the scope of the reaction is further demonstrated by transforming the trifluoro acetamide 25 to the 8‐(trifluoromethyl)guanine (27), and the N,N′‐bis(nitrosopyrimidinyl)‐dicarboxamide 29 to the (R,R)‐1,2‐di(guan‐8‐yl)ethane‐1,2‐diol (32). An intramolecular Diels–Alder reaction of the N‐sorbyl (=N‐hexa‐2,4‐dienoyl) nitrosopyrimidine 10, followed by a spontaneous elimination to cleave the N,O bond of the initial cycloaddition product provided the pteridinones 14 or 15, characterized by a (Z)‐ or (E)‐3‐hydroxyprop‐1‐enyl group at C(6). Treatment of 10 with Ph3P led to the C(8)‐penta‐1,3‐dienyl‐guanine 18. The ene reaction of the N‐crotonyl (=N‐but‐2‐enoyl) nitrosopyrimidine 19 provided the 6‐vinyl‐pteridinone 20a that dimerized readily to 21a, while treatment of 19 with Ph3P led in high yield to 8‐(prop‐1‐enyl)guanine (23). The structure of the dimer 21 was established by X‐ray analysis of its bis(N,N‐dimethylformamidine) derivative 21b. The crystal structure of the nitroso amide 10 is characterized by two molecules in the centrosymmetric unit cell. Intermolecular H‐bonds connect the amino group to the amide carbonyl and to N(1). The crystalline bis(purine) 30 forms a left‐handed helix with four molecules per turn and a pitch of 30.2 Å.
Three New Glycosides from the Stems of Miliusa balansae
Authors: Lei Yu , Wu Li‐Jun , Shi Hai‐Ming , Tu Peng‐Fei 
Published: March 2008

AbstractThree new glycosides with the same saccharides, namely miliusoside A (1), miliusoside B (2), and miliusoside C (3), together with five known compounds were isolated from the stems of Miliusa balansae. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison with the spectra of related model compounds. There was a rarely encountered α‐D‐apiose moiety occurring in all new compounds.
On the Most Powerful Chemical Traps for Bis(methoxycarbonyl)carbene (=2‐Methoxy‐1‐(methoxycarbonyl)‐2‐oxoethylidene)
Authors: Shevchenko Vladimir V. , Zhegalova Natalya G. , Borzenko Andey O. , Nikolaev Valerij A. 
Published: March 2008

AbstractThe efficiency and validity of different chemical substrates for trapping bis(methoxycarbonyl)carbene (=2‐methoxy‐1‐(methoxycarbonyl)‐2‐oxoethylidene; 1) is dependent on the conditions of carbene generation. On conventional photolysis of dimethyldiazomalonate (=2‐diazopropanedioic acid dimethyl ester; 2) by long‐wave UV light (through a Pyrex filter, λ>290 nm), the most powerful trap for carbene 1 in the series of substrates Me2S, MeOH, cyclohexane, and pyridine is Me2S (with an efficiency ratio of ca. 6 : 4 : 2 : 1, resp.). When short‐wave decomposition of diazomalonate 2 is employed (through a quartz filter, λ>210 nm), more reliable and useful chemical traps for bis(methoxycarbonyl)carbene (1) are pyridine and cyclohexane, whose adducts with 1 are rather stable under short‐wave‐irradiation conditions. Application of alcohols for the trapping of 1 proves to be preferential when simultaneous monitoring of carbene and oxoketene formation during photolysis is necessary.
Synthesis and Conformational Analysis of Pentapeptides Containing Enantiomerically Pure 2,2‐Disubstituted Glycines
Authors: Brun Kathrin A. , Linden Anthony , Heimgartner Heinz 
Published: March 2008

AbstractThe synthesis and conformational analysis of model pentapeptides with the sequence Z‐Leu‐Aib‐Xaa‐Gln‐Valol is described. These peptides contain two 2,2‐disubstituted glycines (α,α‐disubstituted α‐amino acids), i.e., Aib (aminoisobutyric acid), and a series of unsymmetrically substituted, enantiomerically pure amino acids Xaa. These disubstituted amino acids were incorporated into the model peptides via the ‘azirine/oxazolone method’. Conformational analysis was performed in solution by means of NMR techniques and, in the solid state, by X‐ray crystallography. Both methods show that the backbones of these model peptides adopt helical conformations, as expected for 2,2‐disubstitued glycine‐containing peptides.
Variability of shallow overland flow velocity and soil aggregate transport observed with digital videography
Authors: Sidorchuk A. , Schmidt J. , Cooper G. 
Published: March 2008

AbstractField experiments at Tiramoana station 30 km north of Christchurch, New Zealand using an erosion plot 16·5 m long, 0·6 m wide, and with a slope of 14–14·5° on rendzina soil aimed to measure the variability of flow velocity and of soil aggregates transport rate in shallow overland flow. Discharge/cross‐section area ratio was used to estimate mean velocity, and high‐speed digital video camera and image analysis provided information about flow and sediment transport variability. Six flow runs with 0·5–3·0 L s−1 discharges were supercritical with Froude numbers close to or more than 1. Mean flow velocity followed Poiseuille law, float numbers were more than 1·5 and hydraulic resistance was an inverse proportional function of the Reynolds number, which is typical for laminar flows. Hence actual velocity varied through time significantly and the power spectrum was of ‘red‐noise’, which is typical for turbulent flow. Sediment transport rates had even higher variability, and soil aggregates transport was a compound Poisson process. Copyright © 2008 John Wiley & Sons, Ltd.
Use of Nash's IUH and DEMs to identify the parameters of an unequal‐reservoir cascade IUH model
Authors: Li Chaoqun , Guo Shenglian , Zhang Wenhua , Zhang Jun 
Published: March 2008

AbstractUnder the assumption that hydrograph generation was affected by n linear reservoirs with the same value of storage coefficient k, Nash proposed the formulation of the Instantaneous Unit Hydrograph (IUH), which has been widely used in rainfall–runoff simulation and flood forecasting. However, the assumption of the parameter k having the same value in all reservoirs is obviously unphysical as it results in the estimated value of n not being integral. In this study, for parameter n integral, the different k value for each reservoir was derived using the Laplace transform and developing a general rule for the equation of the IUH of any order. The relationship between parameter k and the slope of the river channel estimated using digital elevation model (DEM) data is established, the parameter estimation procedures are given. As in most unit hydrograph studies, only isolated storm events are considered here. Seventeen flood events in three catchments were selected for the case studies. Application results show that the proposed method is slightly better than Nash's IUH with higher model efficiency and smaller absolute relative errors. This work provides a new methodology for the formulation of the IUH. Copyright © 2008 John Wiley & Sons, Ltd.
Runoff curve numbers for steep hillslopes with natural vegetation in semi‐arid tropical highlands, northern Ethiopia
Authors: Descheemaeker Katrien , Poesen Jean , Borselli Lorenzo , Nyssen Jan , Raes Dirk , Haile Mitiku , Muys Bart , Deckers Jozef 
Published: March 2008

AbstractDaily runoff from 27 plots (5 m × 2 m) recorded during two rainy seasons in the Tigray highlands (Ethiopia) were analysed together with daily rainfall to calculate runoff curve numbers for hillslopes covered by semi‐natural vegetation in varying stages of vegetation restoration. Curve number model parameters were derived using a least squares fitting procedure on the collected rainfall–runoff datasets. Curve numbers varied from 29 to 97. Land use type was an important explanatory factor for the variation in curve numbers, whereas hydrologic soil group was not. Curve numbers were negatively correlated with vegetation cover. Taking into account antecedent soil moisture conditions did not improve runoff prediction using the curve number method. As runoff prediction was less accurate in areas with low curve numbers, two separate regression functions relating curve numbers with vegetation cover were proposed for different land use types. Copyright © 2008 John Wiley & Sons, Ltd.
Storm‐event rainfall–runoff modelling approach for ungauged sites in Taiwan
Authors: Wang Yu‐Chi , Chen Shien‐Tsung , Yu Pao‐Shan , Yang Tao‐Chang 
Published: March 2008

AbstractThis work develops a top‐down modelling approach for storm‐event rainfall–runoff model calibration at unmeasured sites in Taiwan. Twenty‐six storm events occurring in seven sub‐catchments in the Kao‐Ping River provided the analytical data set. Regional formulas for three important features of a streamflow hydrograph, i.e. time to peak, peak flow, and total runoff volume, were developed via the characteristics of storm event and catchment using multivariate regression analysis. Validation of the regional formulas demonstrates that they reasonably predict the three features of a streamflow hydrograph at ungauged sites. All of the sub‐catchments in the study area were then adopted as ungauged areas, and the three streamflow hydrograph features were calculated by the regional formulas and substituted into the fuzzy multi‐objective function for rainfall–runoff model calibration. Calibration results show that the proposed approach can effectively simulate the streamflow hydrographs at the ungauged sites. The simulated hydrographs more closely resemble observed hydrographs than hydrographs synthesized using the Soil Conservation Service (SCS) dimensionless unit hydrograph method, a conventional method for hydrograph estimation at ungauged sites in Taiwan. Copyright © 2008 John Wiley & Sons, Ltd.
Periodic changes of stream flow in the last 40 years in Tarim River Basin, Xinjiang, China
Authors: Chen Yaning , Pang Zhonghe , Hao Xingming , Xu Changchun , Chen Yapeng 
Published: March 2008

AbstractUsing the annual runoff series for the last 40 years from the Tarim River Basin, their periodic properties were analysed and their future trends predicted. Runoff data were collected at five hydrological gauging stations in the three main branches of the Tarim River. An extrapolation method and variance analysis were used to identify periods in annual runoff, and a trend superposition model to predict future changes. Results show that, there is a common period of 17 years in annual runoff changes for all three branches, with Hotan River showing an additional period of 10 years. Based on this trend, it is suggested that the annual runoff of the Tarim River should decrease in the period of 2006–2008, but increase in year 2009, and the flow may possibly begin to decrease significantly in year 2010. The long term trend of runoff in Tarim Basin has followed the global prediction of GCMs, i.e. began to increase in accordance with global increase of air temperature and precipitation in 1990. However, it has shown a local feature of uneven changes among the head streams in the same basin, which needs to be further investigated. Copyright © 2008 John Wiley & Sons, Ltd.
Apatite‐mineralized polycaprolactone nanofibrous web as a bone tissue regeneration substrate
Authors: Yu Hye‐Sun , Jang Jun‐Hyeog , Kim Tae‐Il , Lee Hae‐Hyoung , Kim Hae‐Won 
Published: March 2008

AbstractDegradable synthetic polymers with a nanofibrous structure have shown great promise in populating and recruiting cells for the reconstruction of damaged tissues. However, poor cell affinity and lack of bioactivity have limited their potential usefulness in bone regeneration. We produced polymeric nanofiber poly(ε‐caprolactone) (PCL) with its surface mineralized with bone‐like apatite for use as bone regenerative and tissue engineering matrices. PCL was first electrospun into a nanofibrous web, and the surface was further mineralized with apatite following a series of solution treatments. The surface of the mineralized PCL nanofiber was observed to be almost fully covered with nanocrystalline apatites. Through mineralization, the wettability of the nanofiber matrix was greatly improved. Moreover, the murine‐derived osteoblastic cells were shown to attach and grow actively on the apatite‐mineralized nanofibrous substrate. In particular, the mineralized PCL nanofibrous substrate significantly stimulated the expression of bone‐associated genes, including Runx2, collagen type I, alkaline phosphatase, and osteocalcin, when compared with the pure PCL nanofiber substrate without mineralization. The currently developed polymer nanofibrous web with the bioactive mineralized surface is considered to be potentially useful as bone regenerative and tissue engineering matrices. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009