bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rectum-conserving surgery in the era of chemoradiotherapy
Authors: Smith F M , Waldron D , Winter D C 
Published: September 2010

Abstract

Background
A complete pathological response occurs in 10–30 per cent of patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy (CRT). The standard of care has been radical surgery with high morbidity risks and the challenges of stomata despite the favourable prognosis. This review assessed minimalist approaches (transanal excision or observation alone) to tumours with a response to CRT.

Methods
A systematic review was performed using PubMed and Embase databases. Keywords included: ‘rectal’, ‘cancer’, ‘transanal’, ‘conservative’, ‘complete pathological response’, ‘radiotherapy’ and ‘neoadjuvant’. Original articles from all relevant listings were sourced. These were hand searched for further articles of relevance. Main outcome measures assessed were rates of local recurrence and overall survival, and equivalence to radical surgery.

Results
Purely conservative ‘watch and wait’ strategies after CRT are still controversial. Originally used for elderly patients or those who refused surgery, the data support transanal excision of rectal tumours showing a good response to CRT. A complete pathological response in the T stage (ypT0) indicates &lt; 5 per cent risk of nodal metastases.

Conclusion
Rectal tumours showing an excellent response to CRT may be suitable for local excision, with equivalent outcomes to radical surgery. This approach should be the subject of prospective clinical trials in specialist centres.
“OpenLAB”: A 2‐hour PCR‐based practical for high school students
Authors: Bouakaze Caroline , Eschbach Judith , Fouquerel Elise , Gasser Isabelle , Kieffer Emmanuelle , Krieger Sophie , Milosevic Sara , Saandi Thoueiba , Florentz Catherine , Maréchal‐Drouard Laurence , Labouesse Michel 
Published: September 2010

AbstractThe Strasbourg University PhD school in Life and Health Sciences launched an initiative called “OpenLAB.” This project was developed in an effort to help high school teenagers understand theoretical and abstract concepts in genetics. A second objective of this program is to help students in defining their future orientation and to attract them to biology. The general idea is a 2‐hour PCR‐based practical that is developed around a fictitious criminal investigation. The practical is taught by PhD graduate students who bring all the required reagents and modern equipment into the classroom. Running the PCR provides free time dedicated to discussions with students about their future plans after the high school diploma. A specific website and a powerpoint presentation were developed to provide appropriate scientific information. Starting on a modest scale in Strasbourg in December 2008, “OpenLAB” was rapidly and well received all around, visiting 53 classes spread over a 200 km area in Alsace until May 2009. It permitted interactions with almost one thousand students in their last year of high school, with the prospect to visit 20% more classes this school year. Our experience, along with feedback from students and their teachers, suggests that it is possible to reach out to many students and have a strong impact with a rather limited budget.
An experimental, hands‐on approach to epithelial ion transport
Authors: Bagdadi Andrea , Orona Nadia , Fernández Eugenio , Altamirano Anibal , Amorena Carlos 
Published: September 2010

AbstractWe have realized that our Biology undergraduate students learn biological concepts as established truths without awareness of the body of experimental evidence supporting the emerging models as usually presented in handbooks and texts in general. Therefore, we have implemented a laboratory practice in our course of Physiology and Biophysics, aimed to introduce the students in the way the scientific models and theories are built, through the measurement of Na+ transport in frog skin. Transepithelial Na+ transport was assessed in the frog skin, with measurements of short circuit currents. The mucosal Na+ and serosal K+ concentrations were modified and the effects were recorded. These effects were reversible. Addition of a drug that blocks epithelial Na+ channels (amiloride) to the mucosal side solution abolished the short circuit current. Sodium fluxes were calculated, and the results were adjusted to Michaelis‐Menten kinetics. The impact of the proposed practice on the students is discussed.
Introducing undergraduate students to real‐time PCR
Authors: Hancock Dale , Funnell Alister , Jack Briony , Johnston Jill 
Published: September 2010

AbstractAn experiment is conducted, which in four 3 h laboratory sessions, introduces third year undergraduate Biochemistry students to the technique of real‐time PCR in a biological context. The model used is a murine erythroleukemia cell line (MEL cells). These continuously cycling, immature red blood cells, arrested at an early stage in erythropoiesis, can be induced to progress further through the process by 72 h exposure to 1.8% DMSO. This gives a control cell sample and a DMSO‐treated preparation. Students isolate RNA from both cell cultures, check its purity, yield and integrity by UV spectrophotometry and denaturing gel electrophoresis, then synthesized cDNA. The relative levels of three sequences: β globin, amino levulinate synthase, and carbonic anhydrase‐1 are estimated by real‐time PCR, using 18S rRNA as the reference sequence. The changes in gene expression are robust and reproducible, enabling students to experience a “cutting edge” research technique in an undergraduate lab setting. While the undergraduate student experience in practical classes with such sensitive techniques is often mixed, the changes in gene expression in this model are sufficiently great that students can gain the satisfaction of consistent results. In addition they gain experience at setting up checks and controls at stages throughout a multistep process and an appreciation of the difference between a reaction which has gone to completion with one that is measured as a rate. This experiment would also complement cell biology projects involving red cell development. It could also be extended to more thoroughly investigate the technique of real‐time PCR.
Problem‐solving test: Tryptophan operon mutants
Authors: Szeberényi József 
Published: September 2010

AbstractTerms to be familiar with before you start to solve the test: tryptophan, operon, operator, repressor, inducer, corepressor, promoter, RNA polymerase, chromosome‐polysome complex, regulatory gene, cis‐acting element, trans‐acting element, plasmid, transformation
Development and validation of a high‐throughput and robust LC–MS/MS with electrospray ionization method for simultaneous quantitation of oseltamivir phosphate and its oseltamivir carboxylate metabolite in human plasma for pharmacokinetic studies
Authors: Kanneti Ravi , Bhavesh Dasandi , Paramar Dharmesh , R Shivaprakash , Bhatt Parloop A. 
Published: September 2010

AbstractA rapid, sensitive and rugged solid‐phase extraction ultraperformance liquid chromatography tandem mass spectrometry (LC‐MS/MS) method was developed for determination of oseltamivir phosphate (OP) and oseltamivir carboxylate (OC) in human plasma. The procedure for sample preparation includes a simple SPE extraction procedure coupled with a Chromatopack C18 column (50 × 3.0 mm, i.d., 3.0 µm) with isocratic elution at a flow‐rate of 0.600 mL /min and acyclovir was used as the internal standard. The analysis was performed on a triple‐quadrupole tandem mass spectrometer by multiple reaction monitoring mode via electrospray ionization. Using 500 µL plasma, the methods were validated over the concentration ranges 0.92–745.98 and 5.22–497.49 ng/mL for OP and OC, with a lower limit of quantification of 0.92and 5.22 ng/mL. The intra‐ and inter‐day precision and accuracy of the quality control samples were within 10.1%. The recovery was 68.72, 70.66 and 71.59% for OP, OC and IS, respectively. Total run time was only 1.0 min. The method was highly reproducible with excellent chromatography properties. Copyright © 2010 John Wiley & Sons, Ltd.
PHOTOCHEMICAL AND ELECTROCHEMICAL PROPERTIES OF TE COMPLEXES cis‐[Co(N2O2)(acac)]
Authors: šima J. , Kotočová A. , Germuša R. , Kubát P. , Engst P. 
Published: September 2010

AbstractThe complexes cis‐[Co(N2O2)(acac)], (where N2O2 = tetradentate dianionic open‐chain ligands of acacen, salen or benacen‐type; acac = 2,4‐pentadionate anion) undergo photoredox reactions under the influence of ultraviolet radiation giving rise to Co(II). The quantum yield values of the Co(III) reduction, associated with the oxidation of the acac ligand, depend on the periphery (substituents R) of the N2O2‐ligands and the wavelength of incident light. The complexes are luminescent from their intraligand excited states.In acetonitrile solution the complexes exhibit an electrochemical oxidation response (Epa: 0.86 to 1,02 V vs SCE) of primarily ligand oxidation origin. A linear correlation has been obtained between the anodic peak potential, Epa and the inductive parameter,σ of the substituents R. The electrochemical reduction of the complexes was poorly resolved or missing within the solvent limit.
SYNTHESE DES PYRAZOLO[2,3‐a]TRIAZEPINO[3,2‐a]BENZIMIDAZOLES ET DES PYRAZOLO[3,2‐d][1,3,5]THIADIAZEPINO[3,2‐a]BENZIMIDAZOLES A PARTIR DES 1,5‐BENZODIAZEPINES
Authors: Essassi E. M. , Salem M. , Viallefont Ph. 
Published: September 2010

Abstract1,5‐benzodiazépine‐2‐thiones were used as precursors in the synthesis of new heterocyclic systems: pyrazolo‐[2,3‐a][1,3,5]triazepino[3,2‐a]benzimidazoles and pyrazolo[3,2‐d][1,3,5]thiadiazepino[3,2‐a]benzimidazoles.
ENANTIOSELEKTIVE KATALYSE, 89AZYKLISCHE UND MAKROZYKLISCHE BINAPHTHYLDERIVATE
Authors: Brunner H. , Schießling H. 
Published: September 2010

AbstractA new synthesis of 3,3′‐diformyl‐2,2′‐dihydroxy‐1,1′‐binaphthyl 1 is described. The macrocyclic compound 3 is formed by Schiff base condensation of two moles of 1 with two moles of (R,R)‐1,2‐Diamino‐1,2‐diphenylethane RR‐2. Reduction of 3 yields the macrocycle 7. The binaphthylketones S‐13 ‐ S‐15 are synthesised starting from (S)‐3,3′‐dicarboxy‐2,2′‐dihydroxy‐1,1′‐binaphthyl S‐16 which is reacted with the corresponding Li‐organic compound. By Schiff base condensation of S‐13 ‐ S‐15 with (R)‐ and (S)‐1‐amino‐1‐phenylethane the new imines 16 ‐ 21 are prepared. The compounds 3 and 16 ‐ 20 are used as optically active ligands in the copper(II)‐catalysed enantioselective cyclopropanation of styrene with ethyl diazoacetate. The product ethyl cis/trans‐2‐phenylcyclopropanecarboxylate is obtained with an optical induction up to 36.6%.
SYNTHESE DE L'ACIDE 3‐(3,6‐DIOXOPIPERAZIN‐2‐YL) PROPANOIQUE
Authors: Jerumanis Stanislas , Lefebvre Jean 
Published: September 2010

AbstractThe 3‐(3,6‐dioxopiperazin‐2‐yl) propanoic acid (8) was synthesized from L‐5‐methyl glutamate (1) and ethyl glycinate. The regioselectivity was controled by using t‐BOC‐ON and EEDQ.
GREEN'S FUNCTION ANALYSIS OF THE VIBRATIONS OF DIBROMOGERMANE
Authors: Kannan K. , Rathnaswami A. , Sankaran V. 
Published: September 2010

AbstractThe Green's function analysis of substituted and perturbed molecules is applied to the study of the vibrations of dibromogermane. The isotopic rules for the perturbation GeH2Br2 → GeD2Br2 are formulated and solved to arrive at the mixing parameter for each species of this molecule. The potential energy constants, mean amplitudes of vibration and Coriolis coupling constants are computed and compared with available literature values.
CONDENSATION INDOLE/NAPHTOQUINONE. SYNTHESE DUNE NOUVELLE SERIE D'INDOLYL‐1,4‐NAPHTOQUINONES
Authors: Henrion Jean‐Christophe , Jacquet Bernard , Hocquaux Michel , Lion Claude 
Published: September 2010

AbstractAddition of an indole, which does not have a group at the 3‐position, to 1,4‐naphthoquinone leads to the expected 2‐(3‐indolyl)‐1,4‐naphthoquinone. When the 1,4‐naphthoquinone is substituted at the 2‐position by an alkyl or aryl group, the 2‐substituted 3‐(3‐indolyl)‐1,4‐naphthoquinone is easily formed. However, when the 2‐substituent of the quinone is functional (OH, OMe, CI, Br, NC5H10, S‐C6H5), in addition to the new series of expected indolylnaphthoquinones, several by‐products resulting from elimination of the 2‐substituted and/or further reaction of these compounds are formed. The outcome at the reaction appears to be very sensitive to the experimental conditions.
DIASTEREOSPECIFICITE DE LA REACTION D'UN YLURE D'AZOMETHINE DERIVE DE LA 1‐PHENYL‐3‐METHOXYCARBONYL‐3,4‐DIHYDRO‐β‐CARBOLINE SUR QUELQUES DIPOLAROPHILES ETHYLENIQUES
Authors: Lakhlifi Takar , An Nguyen Dinh , Schmitt GÉRard , Laude Bernard , Mercier Marie‐France 
Published: September 2010

AbstractThe synthesis of the 1‐phenyl‐3‐methoxycarbonyl‐3,4‐dihydro‐β‐carboline was described. This compound is an azomethine ylid precursor which reacts diastereo‐specifically with activated dipolarophilic olefines to yield cycloadducts involving at the same time, the b‐carboline and the dehydro‐nor‐tropane moities. The diastereochemistry of the 1,3‐dipolar cycloaddition of cyclic azomethine ylids towards the endo rule was reinvistigated.
Intramolecular Diels‐Alder Reactions of 2(1H)‐Pyrazinones: Synthesis of Dihydrofuro‐ and Dihydropyrrolo[2,3‐c]Pyridin‐7(6H)‐ones
Authors: Vandenberghe Didier M. , Hoornaert Georges J. 
Published: September 2010

Abstract2(1H)‐pyrazinones carrying a dienophilic side chain at the 3‐position undergo Intramolecular Diels‐Alder reactions to give new dihydrofuro[2,3‐c/pyridin‐7(6H)‐ones and dihydropyrrolo[2,3‐c]pyridin‐7(6H)‐ones.
Polystyrene Immobilized Ir(III) Complex as a new Material for Optical Oxygen Sensing
Authors: Vander Donckt E. , Camerman B. , Hendrick F. , Heme R. , Vandeloise R. 
Published: September 2010

AbstractThe luminescence spectra of tris(phenylpyridine)iridium embedded in Amberlite (polystyrene adsorbent) have been measured under various O2/N2 mixtures (total pressure = 1 atm). It is shown that the Stern‐Volmer plots are downward curved and that the curvature can be explained either by a two‐site model or by a negative deviation from Henry's law. A curve fitting procedure cannot distinguish between the two models.Using a frequency modulated blue LED and a fiber optic set‐up, O2 partial pressure of 0.4 mbar could be detected. Oxygen can be determined at 200 mbar with a 1.5% accuracy.
Heterocyclisations of 3‐Trifluoroacetyl‐1‐Methyl‐Lactams with 1,4‐Bis‐Nucleophiles
Authors: Bouillon J. P. , Wynants C. , Janousek Z. , Viehe H. G. , Tinant B. , Feneau‐Dupont J. , Declercq J. P. 
Published: September 2010

AbstractHeterocyclizations of 1,4‐bis‐nucleophiles with the new 3‐trifluoroacetyl‐lactams 1a‐c differ from 1,2‐ or 1,3‐bisnucleophiles since they proceed without opening of the lactam structure to give benzoxazolidines 4‐6, benzothiazolidines 7‐9 and benzimidazolidines 13 as mixtures of two diastereoisomers in various proportions. The structure and the absolute configuration of these heterocycles were established by X‐Ray diffraction analysis and by comparison of 19F‐and 13C‐NMR data.
Erythritol: A Versatile Precursor for C‐4 Chiral Building Blocks
Authors: Pottie M. , De Lathauwer G. , Vandewalle M. 
Published: September 2010

AbstractStarting from erythritol, enzyme catalyzed construction of C4 chiral building blocks is described. The four diastereomeric protected tetroses are available from this single compound. Also an approach to L‐ and D‐hexose‐derivatives is presented.
Rearrangement and Cyclization of β‐Mesyloxy Ketones. Synthesis of δ‐Sultones
Authors: Kimpe Norbert De , Boeykens Marc , Lazar Laszio , Szakonyi Zsolt , Kemme Andrejs , Duburs Gunars 
Published: September 2010

AbstractThe reactivity of β‐mesyloxy ketones towards N‐nucleophiles and bases was evaluated. In the presence of titanium(IV) chloride, the reaction with primary amines leads to the formation of β‐mesyloxy imines and β‐amino imines. Upon base treatment, β‐mesyloxy ketones underwent cyclization to δ‐sultones. Increasing steric hindrance in β‐mesyloxy ketones changed the reaction course and gave rise to the formation of cyclobutanones and 2‐methyleneoxetanes.
Thermolysis of 4‐Heteroaryl Substituted 5‐AZIDO‐1H‐1,2,3‐Triazoles: Competition Between Rearrangement and Decomposition
Authors: L'Abbé Gerrit , Vercauteren Karin , Dehaen Wim 
Published: September 2010

Abstract5‐Azidotriazoles bearing a thiazole, benzothiazole or pyridine ring at the 4‐position were synthesized and thermolyzed at 60°C. Whereas the 5‐azido‐4‐(thiazol‐2‐yl)triazole 4 decomposed with extrusion of nitrogen and formation of the triazene 5 as the sole reaction product, the 5‐azido‐4‐(benzothiazol‐2‐yl)triazoles 11a,b furnished mixtures of the triazenes 12a,b and the tetrazoles 14a,b. In the case of the 5‐azido‐4‐(2‐pyridyl)triazoles 17a‐d, the product distribution was found to depend strongly on the N‐1 aryl substituent, favouring the tetrazole 20 by increasing the electron‐withdrawing capacity of this group.
Xanthate Transfer Cyclisation of Glycine Radicals; Synthesis of 5‐ and 6‐Membered Ring Nitrogen Heterocycles
Authors: Udding Jan H. , Giesselink J. P. M. , Hiemstra Henk , Nico Speckamp W. 
Published: September 2010

AbstractXanthate transfer radical cyclisations of several glycine derivatives and substituted N‐methylcarbamates are reported. These reactions proceed via 2‐aza‐5‐alkenyl and 2‐aza‐6‐alkenyl radicals as intermediates which bear an electron‐withdrawing carbonyl substituent at nitrogen. The xanthate‐mediated cyclisation method renders slow radical cyclisation processes successful, leading to ring systems which are not readily accessible by other methods. The γ‐thio substituent incorporated into the cyclisation product allows the synthesis of two conformationally restricted methionine analogues. An X‐ray crystal structure of one of the cyclization products is presented.
1,3‐Dipolar Cycloadditions of Phenanthridinium‐Based Azomethine Ylides
Authors: Dostál Jiří , Potáček Milan , Humpa Otakar , Marek JaromÍR 
Published: September 2010

AbstractAzomethine ylides generated from 5‐(alkoxycarbonylmethyl)phenanthridinium cations were studied in 1,3‐dipolar cycloadditions with dimethyl maleate and dimethyl fumarate as dipolarophiles. The cycloadducts with the pyrrolidino[1,2‐f]phenanthridine skeleton easily underwent dehydrogenation. The structure of products was determined by X‐ray, NMR and MS.
Synthese de derives de l'acide pipecolique par reaction d'aza‐diels‐alder: Cycloadditions activees par l'iodure de zinc entre la 1‐(phenyl)‐ethylimine du glyoxylate de methyle et les dienes riches en electrons
Authors: Abraham HervÉ , Théus Elisabeth , Stella Lucien 
Published: September 2010

AbstractThe methyl N‐(1‐phenylethyl)‐α‐iminoacetate undergoes zinc iodide activated aza‐Diels‐Alder cycloaddition reactions with electron rich conjugated dienes. Cyclic α‐amino‐acids are formed in good yields, with complete regioselectivity, but the extent of asymmetric induction by the chiral phenethyl group on the nitrogen is low.
Synthesis of L‐Erythro‐α,β‐Dihydroxy‐GABA and γ‐Hydroxy‐L‐Erythronine by Oxidative Degradation of Amino‐4‐Pentenediols
Authors: Kirschbaum Bettina , Stahl Ulrich , Volker Jäger  
Published: September 2010

AbstractThe regioisomeric epoxy‐4‐pentenols B and D, readily accessible from 1,4‐pentadiene‐3‐ol A in high stereoisomer purity by Sharpless epoxidation, have been shown to produce various regio‐ and stereoisomers of amino‐4‐pentenediols in a controlled manner. The N‐protected derivatives of 1‐ and 3‐aminopentenediols 2 and 11, respectively, are suitable for oxidative degradation to amino acid derivatives. Subsequent hydrolysis provides the rare amino‐dihydroxy‐butyric acid hydrochlorides 9 and 15.
1,4‐Photoaddition of Five Captodative 2‐Aminoacrylonitriles to Methyl 1‐Naphthoate
Authors: Dietrich Döpp  , Mlinaric Birgit 
Published: September 2010

AbstractBroadband (λ ≥ 280 nm) UV excitation of methyl 1‐naphthoate (1) in cyclohexane solution in the presence of 2‐aminoacrylonitriles 2b‐f results in a highly regio‐ and stereoselective [4+2]addition with formation of the tricyclic adducts 3b‐f as major products accompanied by minor amounts of one or two byproducts of hitherto unclarified connectivity and structure. The rel‐(1R,4R,9R)‐configuration is assigned to the main products on the basis of analogy and NOE‐intensity enhancement studies with compounds 3b,c.
Fused‐Skeleton Saturated Six‐Membered 1,3‐N,O, N,N and N,S Heterocycles. Fused‐Skeleton Aryl‐Substituted Saturated Isoindolones
Authors: Bernáth G. 
Published: September 2010

AbstractIn the introduction, a brief survey is given of the main types of fused‐skeleton saturated six‐membered 1,3‐heterocycles serving as model compounds in our earlier investigations and as starting compounds in the present studies. The synthesis and conformational analysis of aryl‐substituted fused‐skeleton saturated 1,3‐oxazines and of aryl‐substituted hetero‐condensed saturated isoindolones are treated. cis‐trans isomerization in the saturated isoindolone moiety of the resulting tricyclic, tetracyclic and pentacyclic systems is discussed in connection with the ring‐closure reactions of cis‐ and trans‐1,2‐disubstituted 1,2‐ and 1,3‐difunctional alicyclic compounds to give alicycle‐fused six‐membered 1,3‐heterocycles. The cycloaddition reactions of dihydro‐1,3 and 3,1‐oxazines and the conformations of the alicycle‐fused tetrahydrooxazine‐azetidinone derivatives obtained are presented. Methods are given for the preparation of saturated thiazolo‐ and thiazino[2,3‐b]quinazolinones. Unambiguous, mainly one‐pot syntheses for the preparation of 1,3‐heterocycles by a retro Diels‐Alder method are discussed.
Heterocycles of Hypervalent Sulfur and Selenium: New Syntheses and Structures
Authors: Reid D. H. , Ding Y. , Lai L. L. , Luh B. J. , Ngoi T. H. 
Published: September 2010

AbstractThis article describes synthetic and structural studies of heterocycles based on hypervalent sulfur and selenium, in particular 1,6,6aλ4‐triheterapentalenes, their monocyclic precursors and related compounds. What may be termed classical 1,6,6aλ4‐triheterapentalenes conform to structure (1), in which Y = S, Se or Te and X and Z are O, S, Se or NR [1]. Many aza analogues of (1) are known in which one or more ring carbon atoms at positions 2, 3, 4 and 5 are replaced by nitrogen atoms. In the majority of known 1,6,6aλ4‐triheterapentalenes, Y = S. Relatively few analogues are known in which Y = Se, and still fewer are known in which Y = Te. Analogues in which X and/or Ze is Te or PR have not hitherto been prepared.
2(1H)‐Pyrazinones and 2H‐1,4‐Oxazin‐2‐ones and their use in Heterocyclic Synthesis
Authors: Hoornaert Georges 
Published: September 2010

AbstractThe synthesis and functionalization of 3,5 dichloro‐2(1H)pyrazinones and the corresponding 2H‐1,4‐oxazin‐2‐ones is described. The use of their multifunctionalized 2‐azadiene system in cycloaddition reactions with electron‐rich and electron‐poor dienophiles and subsequent eliminations from the adducts of alkynes or nitriles is discussed. In this way pyridine or pyrazine derivatives can be obtained. Application of an intramolecular version of the cycloaddition‐elimination process is shown to yield c‐anellated 2(1H)pyridin(on)es from 2(1H)pyrazinones anchored with an appropriate side chain in position 3 or 6. The specific combination of a 2‐azadiene system, 3‐chlorimine group and a reactive lactone function in the 2H‐1,4‐oxazin‐2‐ones is demonstrated to generate specifically substituted oxazoles, triazoles and tetrazoles on reaction and further conversion with specific nucleophiles. The mechanism of these processes is briefly mentioned together with their application in the synthesis of nucleoside or alkaloid‐type compounds.