bluuebunny/crossref_metadata_2025_split huggingface dataset:
A versatile synthesis of 4,5‐dihydropyrrolo[1,2‐a]quinoxalines
Authors: Abonia Rodrigo , Insuasty Braulio , Quiroga Jairo , Kolshorn Heinz , Meier Herbert 
Published: March 2009

AbstractThe reaction of 1‐(2‐aminophenyl)pyrrole with aromatic or heteroaromatic aldehydes in ethanol and catalytic amounts of acetic acid leads to 4,5‐dihydropyrrolo[1,2‐a]quinoxalines in high yields. When aliphatic aldehydes were used under the same conditions, a slow oxidation to the corresponding pyrrolo[1,2‐a]quinoxalines can occur; the oxidation can be avoided by preparing in situ the 5‐acetyl derivatives of the 4,5‐dihydropyrrolo[1,2‐a]quinoxalines.
Synthesis and [3+2] cycloaddition reaction of 3‐[(trimethylsilylmethylamino)(methylthio)‐methylene]heterocyclic compounds
Authors: Tominaga Yoshinori , Takada Satoshi , Kohra Shinya , Shigemitsu Yasumitsu 
Published: March 2009

Abstract3‐[(Trimethylsilylmethylamino)(methylthio)]methylene‐2‐coumaranone (4a) and 1‐methyloxindole (4b), readily prepared by reactions of the corresponding bis(methylthio)methylene heterocyclic compounds (2a, b), with (trimethylsilylmethyl)amine (3), were found to be synthetic equivalents of heterocyclic alkylidene‐azomethine ylides. Reactions of 4a, b with reactive heterodipolarophiles such as aldehydes and ketones and reactive alkenes in the presence of cesium fluoride gave the 1,3‐dipolar cycloadducts, 3‐(2‐oxazoli‐dinylidene)‐oxindole and ‐coumaran‐2‐one derivatives (8a‐j, 9a‐h), as well as pyrrolylidenecoumaran‐2‐one and oxindole derivatives (12‐15,17,18), via the 1,3‐elimination of (methylthio)trimethylsilane.
Triazolylbenzimidazolthiones and derivatives of the new 1,2,3‐triazolo[ 1,5‐a][ 1,3,5]benzotriazepine heterocycle
Authors: Biagi Giuliana , Giorgi Irene , Livi Oreste , Nardi Antonio , Scartoni Valerio 
Published: March 2009

AbstractFour new triazolylbenzimidazolthione derivatives (2a‐d), analogous to triazolylbenzimidazolone derivatives previously tested as activators of the BKCa potassium channels, were prepared and assayed without success. Some derivatives of a new tricyclic nitrogen heterocycle, 1,2,3‐triazolo[1,5‐a][1,3,5]benzo‐triazepine, bearing a carboxamido group in the 3 position, other substituents in the 8 position and a carbonyl (5a‐d) or thione (6a‐c) or methylthio (7a‐c) function in the 5 position were synthesised. The nucleophilic displacement of the methylthio substituent with morpholine or cyclopentylamine provided the 5‐amino‐substituted tricyclic derivatives 8a‐d. Starting from the l‐(2‐nitrophenyl)‐4‐cyano‐5‐amino‐1,2,3‐triazole (9), the 3‐cyano‐triazolobenzotriazepin‐5‐one derivative 12 was also obtained. The majority of the new compounds were tested towards the BKCa potassium channels, the benzodiazepine and adenosine A1 and A2a receptors, but no remarkable activity was detected.
The psuedo‐michael reaction of 2‐aminoimidazolines 2. Part 1. Synthesis and structure assignment of isomeric 5(1H)‐Oxo and 7(1H)‐Oxo‐2,3‐dihydroimidazo[1,2‐a]pyrimidine‐6‐carboxylates
Authors: Matosiuk Dariusz , Pihlaja Kalevi , Ovcharenko Vladimir V. , Dybała Izabela , Kozioł Anna E. , Gdaniec Maria , Szumiło Halina , Karczmarzyk Zbigniew 
Published: March 2009

AbstractThe pseudo‐Michael reaction of 1‐aryl‐2‐aminoimidazolines‐2 with diethyl ethoxymethylenemalonate (DEEM) was investigated. Extensive structural studies were performed to confirm the reaction course. For derivatives with N1 aromatic substituents, it was found that the reaction course was temperature dependent. When the reaction temperature was held at −10 °C only the formation of 1‐aryl‐7(1H)‐oxo‐2,3‐dihydroimi‐dazo[1,2‐a]pyrimidine‐6‐carboxylates (4) was observed in contrast to earlier suggestions. Under the room temperature conditions, the same reaction yielded mixtures, with varying ratio, of isomeric 1‐aryl‐7(1H)‐oxo‐ (4a‐4f) and 1‐aryl‐5(1H)‐oxo‐2,3‐dihydroimidazo[1,2‐a]pyrimidine‐6‐carboxylates (5a‐5f). The molecular structure of selected isomers, 4b and 5c, was confirmed by X‐ray crystallography. Frontal chro‐matography with delivery from the edge was applied for the separation of the isomeric esters. The isomer ratio of the reaction products depended on the character of the substituents on the phenyl ring. The 1‐aryl‐7(1H)‐oxo‐carboxylates (4a‐4f) were preferably when the phenyl ring contained H, 4‐CH3, 4‐OCH3 and 3,4‐Cl2 substituents. Chloro substitution at either position 3 or 4 in the phenyl ring favored the formation of isomers 5a‐5f. The isomer ratios were confirmed both by 1H NMR and chromatography. The reaction of the respective hydrobromides of 1‐aryl‐2‐aminoimidazoline‐2 with DEEM, in the presence of triethylamine, gave selectively 5(1H)‐oxo‐esters (5a‐5f).
Structure analysis of some α‐(n‐methyl‐n‐formylaminomethyl)‐quinolines
Authors: Maślankiewicz Andrzej , Michalik Ewa , Kowalski Andrzej 
Published: March 2009

AbstractThe 1H and 13C nmr spectra of the rotational isomers 3a and 3b of 6‐N‐methyl‐N‐formylaminomefhyl)‐thioquinanthrene were completely assigned with a combination of 1D and 2D nmr techniques. The key‐parts of this methodology were long‐range proton‐carbon correlations and NOE experiments with N‐methyl‐N‐formylaminomethyl substituent. The X‐ray study of 4‐methyl‐2‐N‐methyl‐N‐formylaminomethyl)quinoline 4a as well as 1H and 13C nmr spectra show that N‐methyl‐N‐formylaminomethyl substituent in 4a and 4b has a different steric arrangement than the same substituent in 3a and 3b.
Characterization and identification of cleavage products of 3‐glycosyl‐5‐substituted‐2‐isoxazoline
Authors: Gelabert Laura I. , Fascio Mirta L. , D'Accorso Norma B. 
Published: March 2009

AbstractWe report herein the synthesis of new synthons obtained by reductive opening of 3‐glycosyl‐5‐substituted‐2‐isoxazolines. Different cleavage products have been obtained depending on the substituents (aliphatic or aromatic) in position five of the heterocycle ring. The new compounds are characterized physically and spectroscopically.
Influence of scale, stoichiometry and temperature on the synthesis of 2,8‐dihalo analogues of tröger's base from the corresponding anilines and paraformaldehyde
Authors: Jensen Jacob , Strozyk Michal , Warnmark Kenneth 
Published: March 2009

AbstractThe yields of 2,8‐dihalo analogues of Tröger's base in the condensation between 4‐haloanilines and paraformaldehyde was found to be highly sensitive to the crucial reaction parameters of scale, stoichiometry and temperature. The reaction conditions were optimized allowing for the semi‐large scale synthesis of the 2,8‐diiodo‐ (2) and 2,8‐dibromo‐ (3) analogues, respectively.
Reaction of tetraazathiapentalene and thiadiazolopyrimidine derivatives with heterocumulenes: Cycloaddition and elimination reactions via hypervalent sulfur intermediates
Authors: Matsumura Noboru , Ito Atsushi , Tomura Masaaki , Okumura Yasuyuki , Mizuno Kazuhiko 
Published: March 2009

AbstractTetraazathiapentalene derivative 1 reacts with heterocumulenes such as diphenylketene (2) and 2‐pyridylisothiocyanate (5) to give heterocycles 3, 6 and 7 with elimination of methylisothiocyanate. The reactions of thiadiazolopyrimidine derivatives 8a‐b with ethoxycarbonyl isothiocyanate (9) and carbon disulfide (11) gives heterocycles 10 and 12 via thermal decomposition of 1:1 cycloadducts C and D which have a hypervalent sulfur. The mechanistic and reactivity features of these reactions are described.
Synthesis and physicochemical characterization of fluorescent (E)‐2‐stilbenyloxyalkylthiouracils and isomer differentiation using EIMS
Authors: Wyrzykiewicz Elzbieta , Wendzonka Monika 
Published: March 2009

AbstractTwelve new fluorescent (E)‐2‐stilbenyloxyalkylthiouracils and 6‐methyluracils 5a‐51 were prepared. EI induced mass spectral fragmentation of these compounds was investigated. Fragmentation pathways are proposed on the basis of accurate mass and metastable transition measurements. Correlation between the intensities of the M+ and the selected fragment ions of these compounds is discussed. The data obtained permit a distinction of the metamers. The 1H and 13C NMR spectra of these compounds were assigned unambiguously using a combination of heteronuclear (HETCOR) spectra and the chemical shifts. The data derived from these spectra can be used to differentiate the isomers.
Novel nucleophilic CC bond‐forming tele‐reaction of imidazole ring
Authors: Ohta Shunsaku , Sato Kentaro , Kawasaki Ikuo , Yamaguchi Yuko , Nishio Satoko , Yamashita Masayuki 
Published: March 2009

AbstractReaction of 2‐(1‐chloro‐2,2‐dimethylpropyl)‐1‐methyl‐1H‐irnidazoles with diethyl methylmalonate in the presence of NaH gave a normal SN product, 2‐[(1,1‐diethoxycarbonylethyl)‐2,2‐dimethylpropyl]‐1‐methyl‐1H‐imidazole (2a), and two tele‐reaction products, 5‐(1,1‐diethoxycarbonylethyl)‐1‐methyl‐2‐(2,2‐dimethylpropyl)‐1H‐imidazole (3a) and trans‐4,5‐di‐(1,1‐diethoxycarbonylethyl)‐4,5‐dihydro‐1‐methyl‐2‐(2,2‐dimethylpropyl)‐1H‐imidazole (4a) in 5, 17 and 70% yields, respectively. The scope and mechanism of this reaction are discussed.
Preparation of pyrrole and pyrrolidine derivatives of pyrimidine. 1‐(2‐pyrimidinyl)pyrrole ‐ an inhibitor of X. phaseoli and X. malvacearum
Authors: Becker Irwin 
Published: March 2009

AbstractPyrrole and pyrrolidine derivatives of pyrimidine were prepared in which the nitrogen atom of the pyrrole or pyrrolidine ring is bonded directly to the 2‐ or 4‐carbon atom of the pyrimidine ring. Pyrrole derivatives were prepared by the dry distillation of an intimate mixture of an aminopyrimidine with mucic acid and by the reaction of a chloropyrimidine with potassium pyrrole. Pyrrolidine derivatives were prepared by the reaction of a chloropyrimidine with pyrrolidine and, in a single instance, by the catalytic hydrogenation of a pyrimidinylpyrrole. At a concentration of 200 mcg/mL, 1‐(2‐pyrimidinyl)pyrrole inhibited two plant pathogenic bacteria — Xanthomanus phaseoli (pathogenic on the bean plant) and Xanthomanus malvacearum (pathogenic on the cotton plant).
Where genetics and pathology meet: mulibrey nanism
Authors: Hes Frederik J , Morreau Hans 
Published: March 2009

AbstractMulibrey nanism is a rare autosomal recessive disorder with prenatal onset growth retardation (nanism) and dysmorphic features, including a wide range of abnormalities, such as cardiac disease (pericardial constriction, myocardial hypertrophy and fibrosis) and anomalies of muscle, liver, brain and eye, resulting in the acronym ‘mulibrey’. This commentary summarizes recent analysis of the diverse pathologies seen in this syndrome and highlights the need for pathologists and geneticists to work together. Insights into the pathology of rare genetic syndromes may have important lessons for our understanding of much commoner conditions. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Human view dynamics—The NATO approach
Authors: Handley Holly A. H. , Smillie Robert J. 
Published: March 2009

AbstractA methodology was established to use the data captured in the NATO Human View to populate a simulation model; this provides a dynamic instantiation of the Human View data. The Improved Performance Research Integration Tool (IMPRINT), provided by the U.S. Army Research Laboratory was used as the simulation environment. By creating the Human View Dynamics, the data captured in the static products can be evaluated through tradeoff analysis and performance criteria. The demonstrated interoperability of the Human View static products and the IMPRINT dynamic modeling capability resulted in a mapping between the two domains. Additionally, the capability of the Integrated Performance Modeling Environment (IPME) used by Canada and the United Kingdom as a simulation environment was reviewed. © 2009 Wiley Periodicals, Inc. Syst Eng
Laparoscopic Radical Nephrectomy for T2 Renal Cell Carcinoma
Authors: Ritchie Robert W. , Sullivan Mark E. , Jones Adam 
Published: March 2009

Background: Large volume centres from the USA suggest laparoscopic radical nephrectomy (LRN) for T2 (>7 cm) renal cell carcinoma (RCC) is safe and associated with few complications. Similar data for low and intermediate volume centres in Europe is lacking. Objective: To determine whether LRN for T2 RCC in two intermediate volume UK hospitals compares favourably with larger volume centres. To determine whether LRN for T2 RCC is associated with favourable outcomes when compared to LRN for T1 RCC. Patients and methods: Data from 118 consecutive LRN performed in Oxford, UK (tertiary academic centre, catchment population 2,000,000) and Reading, UK (large district general hospital, catchment population 500,000). All patients undergoing LRN from 2004 to 2008 were included; outcome data were collected prospectively. All patients underwent a standard 4-port trans-peritoneal LRN with intact specimen removal. Patients were divided into two groups—Group 1 (clinical T1 tumours) and Group 2 (clinical T2 tumours). Demographic data and operative outcome data were collected for every patient including age, weight, operative duration, estimated blood loss, transfusion rates, complications, hospital stay and histology. Data were compared using Chi-square test and the Student t-test. Results: Mean patient age was 62.5 years; 57% of tumours were right sided. Mean tumour dimension in Group 1 was 4.3cm and 9.3cm in Group 2. Demographics were similar between the two groups. Operative duration, estimated blood loss and transfusion rates were significantly greater in Group 2. Despite this, complication rates, conversion rates and hospital stay were similar. 12% of tumours were benign and nearly half of all clinical T2 tumours were ultimately staged T3 on final histology. Conclusions: LRN for T2 RCC can be performed safely in intermediate volume centres. The procedure is more challenging but operative outcomes are similar to LRN for smaller tumours. Many >7 cm RCC are T3 on final histology.
Daily interruption of sedative infusions in an adult medical–surgical intensive care unit: randomized controlled trial
Authors: Anifantaki Stella , Prinianakis Georgios , Vitsaksaki Efsevia , Katsouli Victoria , Mari Stella , Symianakis Antonios , Tassouli Georgia , Tsaka Eleni , Georgopoulos Dimitris 
Published: March 2009

AbstractTitle.  Daily interruption of sedative infusions in an adult medical–surgical intensive care unit: randomized controlled trial. Aim.  This article is a report of a study conducted to determine if a nursing‐implemented protocol of daily interruption of sedative infusions vs. sedation as directed by the intensive care unit team would decrease duration of mechanical ventilation.Background.  Continuous rather than intermittent infusion of sedative and analgesic agents leads to greater stability in sedation level, but has been correlated with prolongation of mechanical ventilation and hospitalization of critical care patients. Daily interruption of sedative infusions in mechanically ventilated patients has reduced the duration of mechanical ventilation and length of stay in intensive care.Method.  A randomized controlled trial was carried out from November 2004 to March 2006 with 97 patients receiving mechanical ventilation and continuous infusion of sedative drugs in an intensive care unit in Greece. The primary outcome measure was the duration of mechanical ventilation. Secondary outcomes were length of intensive care unit stay, length of hospital stay, overall mortality, total doses of sedative and analgesic medicines and Ramsay scores and duration of cessation of sedative infusions per day.Results.  The median duration of mechanical ventilation was 8·7 days vs. 7·7 days (P = 0·7). Length of intensive care unit stay (median: 14 vs. 12, P = 0·5) and in the hospital (median: 31 vs. 21, P = 0·1) was similar between the intervention and control groups. The absence of statistically significant differences in these variables remained when patients with brain injury were examined separately.Conclusion.  The nursing‐implemented protocol of daily interruption of sedative infusions was neither beneficial nor harmful compared with usual practice, which has as its primary target the earliest possible awakening of patients.
Origin of Mediterranean insular endemics in the Boraginales: integrative evidence from molecular dating and ancestral area reconstruction
Authors: Mansion Guilhem , Selvi Federico , Guggisberg Alessia , Conti Elena 
Published: March 2009

AbstractAim  The presence of numerous reliable fossils and the occurrence of many endemic island species make the Boraginales particularly suitable for integrative biogeographical studies. In this paper we aim to elucidate the time frame and events associated with the origin of selected borages endemic to the Mediterranean climate zone. More specifically, we describe and examine the alternative palaeo‐ and neoendemic hypotheses for their origin.Location  Corsica and Sardinia (continental fragment islands) and the Canary Islands (an oceanic island archipelago).Methods  Eighty‐nine accessions, representing 30 genera from five families ascribed to the Boraginales, were examined for six chloroplast DNA regions. We used an integrative approach including phylogenetic analyses (MrBayes), Bayesian molecular dating (T3 package) with four fossil constraints on nodes, and biogeographical reconstructions (diva) to elucidate the temporal and spatial origins of the Corso‐Sardinian and Canary Island endemics.Results  Species of Echium endemic to the Canary Islands diverged from their continental sister clade during the Miocene (15.3 ± 5.4 Ma), probably after the rise of the oldest islands (c. 20 Ma). Corso‐Sardinian endemics of Borago diverged from their primarily North African sister clade during the late Miocene‐Pliocene (c. 6.9 ± 3.6 Ma), well after the initial fragmentation of the islands (c. 30 Ma). Similarly, Corso‐Sardinian endemics of Anchusa diverged from the South African Anchusa capensis during the Pliocene–Pleistocene (c. 2.7 ± 2.1 Ma).Main conclusions  The present study reveals an Anatolian origin for Anchusa, Borago and Echium and underlines the importance of the Eastern Mediterranean region as a possible reservoir for plant evolution in the Mediterranean Basin. For Anchusa and Borago, the divergence from their respective sister clades on the two types of islands post‐dated the formation of the islands, thus supporting the neo‐endemic hypothesis, whereas the dating results for the origin of Echium endemics were less conclusive.
Risk factors for oral clefts: a population‐based case‐control study in Shenyang, China
Authors: Wang Wei , Guan Peng , Xu Wei , Zhou Baosen 
Published: March 2009

SummaryShenyang in Northern China has one of the highest reported prevalence rates of oral clefts in the world. To explore the risk factors for oral clefts in Shenyang, we carried out a population‐based case‐control study. A total of 360 990 births in 2000 to 2007 were screened for oral clefts; the overall prevalence was 1.76 per 1000. The ratio of cleft lip with or without cleft palate (CL ± P) : cleft palate only (CP) was 5.60:1. The overall male : female ratio was 2.02:1. CLP and CL were more common in males than in females with a sex ratio (SR) of 2.88:1 and 1.86:1 respectively, whereas CP was more common in females with an SR of 0.71:1.Using a multivariable conditional logistic regression model, 586 oral clefts cases were compared with 1172 control mothers. Maternal factors significantly associated with increased risk for oral clefts were history of a fever or cold (adjusted OR 2.34, 95% CI 1.06, 5.60); use of analgesic and antipyretic drugs (adjusted OR 3.10, 95% CI 1.41, 6.86); poor ventilation during heating (adjusted OR 2.25, 95% CI 1.10, 4.60); and consumption of pickled vegetables >6 per week (adjusted OR 3.86, 95% CI 1.11, 13.47) during pregnancy. Factors which appeared to be protective were meat consumption ≥4 times per week (adjusted OR 0.43, 95% CI 0.28, 0.67); and legume consumption >6 times per week (adjusted OR 0.60, 95% CI 0.41, 0.89). Differences in risk were found between the two most common phenotypes, CL ± P and CP only. Most of the environmental factors had stronger associations with risk for CL ± P rather than CP, whereas history of oral clefts, as well as legume consumption, were more strongly associated with the risk for CP than for CL ± P. The findings suggest that aetiological heterogeneity may exist between CL ± P and CP.
Delayed fluorescence as a universal tool for the measurement of circadian rhythms in higher plants
Authors: Gould Peter D. , Diaz Patrick , Hogben Claire , Kusakina Jelena , Salem Radia , Hartwell James , Hall Anthony 
Published: March 2009

SummaryThe plant circadian clock plays an important role in enhancing performance and increasing vegetative yield. Much of our current understanding of the mechanism and function of the plant clock has come from the development of Arabidopsis thaliana as a model circadian organism. Key to this rapid progress has been the development of robust circadian markers, specifically circadian‐regulated luciferase reporter genes. Studies of the clock in crop species and non‐model organisms are currently hindered by the absence of a simple high‐throughput universal assay for clock function, accuracy and robustness. Delayed fluorescence (DF) is a fundamental process occurring in all photosynthetic organisms. It is luminescence‐produced post‐illumination due to charge recombination in photosystem II (PSII) leading to excitation of P680 and the subsequent emission of a photon. Here we report that the amount of DF oscillates with an approximately 24‐h period and is under the control of the circadian clock in a diverse selection of plants. Thus, DF provides a simple clock output that may allow the clock to be assayed in vivo in any photosynthetic organism. Furthermore, our data provide direct evidence that the nucleus‐encoded, three‐loop circadian oscillator underlies rhythms of PSII activity in the chloroplast. This simple, high‐throughput and non‐transgenic assay could be integrated into crop breeding programmes, the assay allows the selection of plants that have robust and accurate clocks, and possibly enhanced performance and vegetative yield. This assay could also be used to characterize rapidly the role and function of any novel Arabidopsis circadian mutant.
Expression of cyclin D2 is an independent predictor of the development of hepatic metastasis in colorectal cancer
Authors: Sarkar R. , Hunter I. A. , Rajaganeshan R. , Perry S. L. , Guillou P. , Jayne D. G. 
Published: March 2009

AbstractIntroduction  Cyclin D1 has been implicated in the progression of several cancers by virtue of its influence on progression of the G1/S phase of the cell cycle. However, little is known about the possible roles of cyclin D2 and D3 in colorectal cancers (CRCs).Method  We investigated the expression levels of cyclin D2 and D3 in 84 CRC specimens. Antigen expression was determined by immunohistochemical analysis of cyclin D1, D2, D3, p16INK4A and Ki67 on tissue microarrays constructed using core samples from tumour centres and margins.Results  For the whole cohort, expression of cyclin D2 at the margin was associated with vascular invasion (P = 0.039), lymph node metastasis (P = 0.020) and liver metastasis (P < 0.001). In patients with stage I and II tumours (n = 84), elevated cyclin D2 and D3 were associated with vascular invasion (P = 0.014 and 0.028 respectively), liver metastasis (P = 0.001 and 0.007 respectively) and reduced disease specific survival (Cyclin D2, P < 0.022). No association was noted between the proliferative marker Ki‐67 and the D‐type cyclins.Conclusion  These findings suggest that cyclin D2 expression at the invasive margin of CRCs is associated with liver metastasis and may serve as a useful prognostic marker and indicator of the need for adjuvant therapy.