bluuebunny/crossref_metadata_2025 huggingface dataset:
Regeneration in Annelids
Authors: Zoran Mark J
Published: September 2010

Annelids, like many other invertebrate animals, replace lost body parts in a process called regeneration. However, the ability to regenerate lost segments is present in some groups and not others, for example leeches do not regenerate lost segments. Anterior and posterior regeneration involves the formation of a bud containing stem cells that differentiate into the new head or tail segments. Annelid regeneration also involves remodelling of surviving body fragments. The ability of annelids to regenerate tail segments appears to be nearly universal among species capable of regeneration. The ability to regenerate head segments, although common, is not universal and can depend on the number of segments lost. The absence and presence of regeneration across annelid groups, including closely related species, suggests that regeneration ability may be an ancient trait that has been lost in some species during annelid evolution. Why regeneration varies among annelid species remains an intriguing question for life scientists.

Key Concepts:

Annelids vary in their capability for regenerating body segments, including among closely related species.

The ability of annelids to regenerate posterior segments appears to be nearly universal.

The ability of annelids to regenerate anterior segments, although common, is not universal and is often limited depending on the number of segments lost.

Annelid regeneration may involve both epimorphic and morphallactic mechanisms.

Multiple losses and gains of regeneration ability have likely occurred during annelid evolution.

Why regenerative ability among annelids varies extensively remains unclear.
Neurofibromatosis Type 2 Clinics and Genetics
Authors: Kluwe Lan , Mautner Victor‐F
Published: September 2010

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterised by multiple benign tumours of the nervous system. More than 90% of the patients develop bilateral vestibular schwannomas, which are the hallmark of NF2 and lead to progressive hearing loss in adult patients. Spinal tumours are as frequent as bilateral vestibular schwannomas, whereas approximately 1/3 of them cause neurological symptoms. Cranial nonvestibular schwannomas, meningiomas and ependymomas are also frequent in NF2, as well as ophthalmological lesions and peripheral polyneuropathy. With a birth incidence of around 1 in 25 000, the genetic cause for NF2 is the heterozygous inactivation of theNF2tumour suppressor gene on 22q. More than half (50–80%) of NF2 patients are founders who bearde novomutations which are present in a mosaic fashion in at least 25–30% of the patients. NF2 is a complex syndrome and demands interdisciplinal care, experienced specialists, social and psychological support and rehabilitation measures.

Key Concepts:

NF2 is a tumour suppressor gene syndrome and is characterised by multiple benign cerebral and spinal tumours.

Bilateral vestibular schwannomas are the hallmark of NF2.

The genetic cause for NF2 is the heterozygotic inactivating mutation of theNF2gene on 22q.

Mosaicism is frequent amongde novoNF2 patients (25–30%).

NF2 is a complex syndrome and demands interdisciplinal care, experienced specialists, coordinated social and psychological supports and rehabilitation measures.
Pathological Mutations in 5′ Untranslated Regions of Human Genes
Authors: Chatterjee Sangeeta , Berwal Sunil Kumar , Pal Jayanta K
Published: September 2010

The 5′ untranslated region (5′‐UTR) of a messenger
ribonucleic acid
(mRNA) plays a critical role in translation regulation by influencing mRNA stability and translation efficiency. Functional elements in the 5′‐UTR such as internal ribosome entry site (IRES), upstream open reading frames (uORFs) and iron responsive element (IRE) serve to fine tune protein expression in response to cellular requirement. Genetic variations such as mutations and single nucleotide polymorphisms (SNPs) in the 5′‐UTR are associated with a number of human diseases and increased susceptibility to diseases. Such pathological variations disrupt the motifs at the 5′‐UTR and cause diseases such as X‐linked Charcot‐Marie‐Tooth (CMTX) disease, multiple myeloma, hereditary hyperferritinaemia/cataract syndrome (HHCS), familial predisposition to melanoma, Marie Unna hereditary hypotrichosis (MUHH), oesophageal cancer and many others. Genetic and molecular profiling of many diseases has shown that a holistic approach of including the UTRs in regular diagnostic
deoxyribonucleic acid
(DNA) screening would aid in better disease profiling and disease management.

Key Concepts:

5′ Untranslated regions (UTRs) are noncoding regions of messenger RNAs (mRNAs).

The 5′‐UTR is delimited by transcription initiation site at 5′ end and the physiological start codon (AUG) at the 3′ end.

Motifs such as internal ribosome entry site (IRES), upstream open reading frames (uORFs), iron responsive element (IRE) and others are involved in mRNA stability and translation control.

mRNAs encoding regulatory proteins need to be strongly and precisely regulated. These mRNAs are often endowed with longer than average 5′‐UTR, uORFs and stable secondary structures that regulate their translation efficiency.

Mutations are changes in the DNA/genes of an organism which are heritable.

Mutations that disrupt the functional elements of the 5′‐UTR are often associated with diseases.

Single nucleotide polymorphisms (SNPs) in the 5′‐UTR are associated with individual's drug response and disease risk.
Molecular Genetics of Cardiovascular Disease
Authors: Lee Wai Kwong , Padmanabhan Sandosh , Dominiczak Anna F
Published: September 2010

Cardiovascular disease is a leading cause of mortality and morbidity worldwide. The presence of significant familial clustering of cardiovascular disease suggests a genetic component in addition to lifestyle and environmental factors in its aetiology. It is this subtle interplay between environment and genes that has made the study of cardiovascular disease at the molecular level very challenging. The polygenic multifactorial basis of cardiovascular traits requires collaborative efforts within the cardiovascular disease community not only to understand the genetic underpinnings of the phenotype but also to translate discoveries into clinically useful applications that will have a major impact on public health.

Key Concepts:

Familial clustering and heritability has provided evidence for the existence of a genetic component for CAD.

The success of finding susceptibility genes will be dependent on the genetic architecture of CAD.

Phenotype definition of a complex disorder and its importance in genetic studies.

Genomic approaches to the dissection of cardiovascular disease have included candidate gene studies, genome‐wide association studies and linkage studies.

The role of microRNA and its role in cardiovascular pathology.

‘Omic approaches’ to cardiovascular disease and the need to integrate each of the omic discliplines in elucidating both the genetic and proteomic factors involved in CVD.
Modifier Genes in the Haemoglobinopathies
Authors: Di Marzo Rosalba , Calzolari Roberta , Rund Deborah , Maggio Aurelio
Published: September 2010

Haemoglobinopathies, such as sickle cell disease (SCD) and thalassaemias, are prototypical single‐gene disorders caused by lesions that affect the
β‐globin
gene (SCD and β‐thalassaemia) or
α‐globin
gene (α‐thalassaemia). Haemoglobinopathies are among the most common human genetic disorders, and patients having the same genotypes can have variable pattern of clinical expression related to environmental as well as genetic factors. Several modifier genes have been identified which are able to influence the severity of these diseases, so at phenotypic level haemoglobinopathies are considered multigenic diseases. It is possible that additional modifiers could be uncovered using genetic approaches but success will depend on large sample sizes of well‐characterised patients with well‐defined phenotypes.

Improved understanding of the influence of modifier genes involved in modulating the complex pathophysiology of haemoglobinopathies may allow prediction of diseases’ phenotype and aid in management of the many complications of these diseases.

Key Concepts:

Haemoglobinopathies, such as sickle cell disease (SCD) and thalassaemias, are prototypical single‐gene disorders caused by lesions that affect the β‐globin gene (SCD and β‐thalassaemia) or α‐globin gene (α‐thalassaemia).

Patients having the same genotypes can have variable pattern of clinical expression related to environmental as well as genetic factors.

The phenotypic variability of the disease is due, at primary level, to the heterogeneity of the causative mutation, especially for thalassaemia.

Modifier genes are defined as inherited genetic variation that leads to a qualitative or quantitative difference in disease phenotype.

Several modifier genes have been identified able to influence the severity of haemoglobinopathies, so at phenotypic level they are considered multigenic diseases.

Alterations of other globin genes and the inheritance of different quantitative trait loci (QTLs) associated with the increase of fetal haemoglobin (HbF) production are the major genetic modifiers in haemoglobin diseases.

Variations in the phenotype of some complications in patients with beta‐thalassaemia and sickle cell anaemia may be affected by genetic variants.
Glioblastoma Models in
Drosophila Melanogaster
Authors: Jeibmann A , Kim SN , Paulus W , Klämbt C
Published: September 2010

Gliomas comprise the most common and most malignant intrinsic human brain tumours, with a very poor prognosis. Despite some recent therapeutic progress, there is still a large demand for novel drug targets to cope with the high recurrence rate. In the present article, we introduce the

Drosophila

model as a new tool in deciphering the mechanisms underlying the generation and progression of glial tumours. Despite the fact that

Drosophila

has only few glial cells and no vascular system with patrolling lymphocytes, the basic principles underlying glioblastoma biology appear very well conserved. The role of
epidermal growth factor
(EGF) receptor pathways, PVR (PDGF‐ and VEGF‐receptor related) and
phophatidylinositol 3‐kinase
(PI3K) signalling in

Drosophila

glioma models is discussed.

Key Concepts:

Gliomas are the most common and most malignant intrinsic human brain tumours, with a very poor prognosis.

In majority of the glioblastoma, the molecular cause of malignancy is due to an amplification of receptor tyrosine kinase genes. The role of EGF‐receptor pathways, PVR and PI3K signalling in
Drosophila
glioma models is introduced in the text.

Glial cell proliferation and glial cell migration is controlled by evolutionary conserved mechanisms.

The insect
Drosophila melanogaster
has a very simple structured nervous and glial cells perform similar tasks as their vertebrate counterparts.

The model organism
Drosophila
provides a rich source to decipher the mechanisms underlying the biology of human glioma and can be used to define novel drug targets.
BiasedDNASegregation
Authors: Karpowicz Phillip
Published: September 2010

Biased chromatid segregation refers to the nonrandom distribution of chromatids in mitotic cells so that specific daughters inherit specific chromosomes ordeoxyribonucleic acid(DNA) strands. This unusual behaviour has been documented primarily in the context of differentiation, when one cell divides to produce two daughter cells with distinct fates. When cells divide asymmetrically to produce such daughters, it has been noted that the DNA in these different daughter cells is dissimilar. Two controversial hypotheses to account for such data have been envisioned thus far: one in which stem cells retain all chromosomes carrying ancestral DNA strands, and one in which precursors segregate one or more, epigenetically dissimilar, strands nonrandomly. Several cases of biased DNA segregation are presented, and the implications of this theory are discussed with a view to general biological issues, the proximate mechanisms underlying these phenomena and the ultimate reasons these might occur.

Key Concepts:

The biased segregation of DNA might function to specify the fate of cells.

It has been proposed that biased DNA segregation reduces DNA mutation load in the cell that retains ancestral, or original, DNA strands.

Stem cell self‐renewal and multipotency, which are accounted for by asymmetric cell division, are also proposed to be an outcome of biased DNA segregation.
Behavioural Genomics: An Organismic Perspective
Authors: Wong Ryan Y , Hofmann Hans A
Published: September 2010

The behavioural patterns observed in many organisms generally result from the integration of both external and internal cues. Why do animals behave the way they do? The study of the proximate and ultimate mechanisms underlying animal behaviour tries to answer this question. Although various approaches have been developed for examining – often quantitatively and with increasing specificity and resolution – the roles genes play in the regulation of behaviour, until recently they were limited to individual candidate genes and often neglected ultimate mechanisms. Advances in genomic approaches in recent years have made it possible to examine gene expression patterns (in the brain and elsewhere) on a genomic scale even in nontraditional, yet ecologically and evolutionarily important model systems. As behavioural genomics begins to integrate proximate and ultimate mechanisms of animal behaviour, we may finally understand why animals behave the way they do.

Key Concepts:

A complete understanding of animal behaviour requires the integration of proximate (causation and development) and ultimate (function and evolution) mechanisms underlying the behaviour.

Genome‐wide expression profiling in the brain (via microarrays or RNA‐Seq) allows for an unbiased view of genes potentially underlying a behaviour.

The genome responds in a rapid and dynamic manner on onset of behaviour or stimulus presentation.

Studies of behavioural genomics open up numerous avenues for future research examining both the intra‐ and interspecific function(s) of candidate genes, gene networks underlying behaviour and the evolution of behaviour.
Analysis of Emerging Disinfection By‐Products in Drinking Water
Authors: Charrois Jeffrey W.A.
Published: September 2010

Disinfection by‐products (DBPs) were detected in drinking water over 35 years ago. Since then identification of DBP species has closely paralleled advances in analytical chemistry. Today over 600 individual DBP species, representing several chemical classes, have been identified in drinking water. Potential DBP health concerns reported by some toxicology and epidemiology studies include elevated risks of developing certain cancers or adverse reproductive outcomes. New drinking water regulations must be evidence‐based, requiring next‐generation DBP studies that better link advances in analytical methods with a focus on DBPs that have the biological plausibility to cause the adverse outcomes we seek to avoid. The strategic development of the nationwide DBP occurrence study in the United States has helped to refocus today's global DBP research agenda toward a new generation of emerging DBPs of health significance. Notable DBP classes now being studied include: halonitromethanes, haloamides, halogenated furanones, haloaldehydes, haloquinones, as well as N‐nitrosamines and iodo‐DBPs. Improvements in extraction, separation, and detection technologies have improved our ability to identify DBP species that were once difficult, if not impossible, to detect by gas chromatography methods. Liquid chromatography/mass spectrometry applications are providing new insights into the monitoring of nonvolatile, high‐molecular‐weight, highly polar, hydrophilic, and thermally labile target compounds in drinking water. On‐line monitoring and expanded studies evaluating swimming pool exposures are the latest innovations in the ongoing interdisciplinary research related to the analysis of emerging DBPs.
Microelectrodes for Electroanalytical Chemistry
Authors: Hyk Wojciech , Stojek Zbigniew
Published: September 2010

Voltammetric/amperometric microelectrodes are well established in electroanalysis. Their dimension is usually in the range of micrometers and less. They may have very different shapes and may work in the form of assemblies. The most popular are microdisk‐ and microcylindrical electrodes. The unique properties of microelectrodes have allowed analysts to create new analytical methods and procedures. On the other hand they can also be used successfully in the areas where regular electrodes dominated for years. It is relatively easy to get steady‐state currents while working with microelectrodes. This feature appeared to be particularly useful in electrochemistry and, in general, in physicochemical investigations. The theory of voltammetry and amperometry with microelectrodes is well developed. This article focuses on the formulas that can be employed while working with microelectrodes under a variety of conditions including the mixed diffusional and migrational transport.
Group Dynamics Processes for Improved Decision Making
Authors: Phillips Lawrence D.
Published: September 2010

This review of group dynamic processes covers those main features that are relevant for operations research (OR) practitioners who work with groups. The review brings together disparate literatures reporting experiences with groups, research from empirical studies, observational studies of on‐going groups working under stress, and systems for improved decision making. Acquaintance with group dynamics can help OR practitioners to see and understand the life of the group, to provide insights about what goes on under the surface, and to better help their clients achieve their objectives.
L
atin–
I
bero–
A
merican
A
ssociation for Operational Research
Authors: Cancela Héctor
Published: September 2010

The Latin–Ibero–American Association for Operational Research, usually known as
Asociación Latino–Ibero–Americana de Investigación Operativa
(ALIO), is the association of the national operational research societies in Latin America and the Iberian Peninsula. This article includes a brief sketch of the history of ALIO and a description of the main activities organized by this association.
Randomized Simplex Algorithms
Authors: Gärtner Bernd
Published: September 2010

A randomized simplex algorithm is a variant of the simplex method in which the rule for choosing the entering variable is randomized. This means that in each pivot step, the choice of the entering variable may depend in a well‐defined way on the outcome of a random experiment. The performance of a randomized simplex algorithm on a given linear program is measured in terms of the expected number of pivot steps taken. Randomized simplex algorithms are studied in the context of the complexity of the simplex method. Randomization allows to beat the known worst‐case complexity bounds of deterministic simplex algorithms.
Russian Scientific Operations Research Society
Authors: Malashenko Yury
Published: September 2010

In 1996, consolidation of representatives of all scientific departments in the field of Operations Research (OR) in the Soviet Union and Russian Federation since 1960 resulted in the establishment of Russian Scientific Operations Research Society (RSORS). The scientific works of Society members are published in leading Russian scientific journals. Scientific conferences organized by the Society attract great interest in OR community and beyond. OR members tested the effectiveness of the application of OR methods in various spheres of human activity including economics, environmental protection, finances, and the computer‐aided design of complex technical systems.
S
lovak Society for Operations Research
Authors: Ivanicova Zlatica
Published: September 2010

In this article, we give the short history of the Slovak Society. Then, we describe the goals of the Society, which have been divided into four classes. The most important is the support of the development of OR as a scientific discipline. Also, we present the activities of the Society as well as the heads of the Society from the year 1993. The principal activity of the Society is organizing the international conference known as “Quantitative Methods in Economics (Multiple criteria decision making).”
Molecular Structure of Metal Enolates
Authors: Babić‐Samardžija Ksenija , Sovilj Sofija P. , Jovanović Vladislava M.
Published: September 2010

Introduction

Vibrational Spectra

UV
‐vis Spectra

NMR
Spectra

EPR
Spectra

Mass Spectra

Molecular Characteristics and Application Perspectives

Acknowledgments
Organomanganese‐Mediated Radical Reactions
Authors: Friestad Gregory K.
Published: September 2010

Free radical reactions offer functional group compatibility which complements that of carbanion reagents. A variety of synthetically useful transformations proceeding via free radicals, including reductions, carbonylations, reductive additions, cyclizations and polymerizations, may be induced by organomanganese reagents. These generate carbon‐centered radicals from organic halides; photolysis with dimanganese decacarbonyl leads to halogen atom abstraction, or triorganomanganate reagents effect electron transfer followed by loss of halide ion. Synthetic methods employing these reagents are reviewed, with emphasis on carbon‐carbon bond construction, stereoselectivity, and applications in natural product synthesis. Reductive dehalogenation, Wurtz coupling, intermolecular radical additions and carbonylations, radical cyclizations including atom transfer methods, and radical addition to imino compounds are discussed in the context of recent developments using organomanganese reagents.
Processing of Ceramic Foams with Hierarchical Cell Structure
Authors: Ceron‐Nicolat Bruno , Fey Tobias , Greil Peter
Published: September 2010

Silicon carbide‐based cellular ceramics characterized by a hierarchical pore structure were processed. An open‐cellular PU foam template with a mean cell density of 10 pores per inch (ppi), equivalent to a cell diameter of 4 mm and a strut thickness of 250 µm, was coated with a primary SiC slurry. Cross‐linking of a polysiloxane binder at 190 h resulted in a SiC filled reticulated thermoset foam (first generation). Subsequently, this matrix foam was infiltrated with a second slurry of slightly different polysiloxane composition which upon heating to 290 °C caused bubble nucleation and formation of a second generation foam filling the cell space in the matrix foam skeleton. After pyrolysis at 1000 °C a SiC/SiOC reaction bonded composite foam with a hierarchical cell structure and a fractional density of 0.31 was obtained. SEM and X‐ray µ‐CT analyses confirm both generations of matrix as well as infiltrated foam to be open cellular but with a pronounced difference in cell size (matrix foam cell size 2.5 mm versus infiltrated foam cell size 0.29 mm). While the matrix foam skeleton provides control of macroscopic shape as well as density distribution in the component, single‐ or multistep foam infiltration may offer a high potential for improving the mechanical properties of hierarchical cellular materials. Thus, hierarchical structure formation offers a high potential to fabricate low density cellular ceramics which might be of interest for lightweight design of novel engineering materials.
Heterointegration of Pt/Si/Ag Nanowire Photodiodes and Their Photocatalytic Properties
Authors: Qu Yongquan , Xue Teng , Zhong Xing , Lin Yung‐Chen , Liao Lei , Choi Jina , Duan Xiangfeng
Published: September 2010

Photocatalyst mediated photoelectrochemical processes can make use of the photogenerated electrons and holes onsite for photocatalytic redox reactions, and enable the harness and conversion of solar energy into chemical energy, in analogy to natural photosynthesis. However, the photocatalysts available to date are limited by either poor efficiency in the visible light range or insufficient photoelectrochemical stability. Here, it is shown that a Pt/Si/Ag nanowire heterostructure can be rationally synthesized to integrate a nanoscale metal‐semiconductor Schottky diode encased in a protective insulating shell with two exposed metal catalysts. The synthesis of Pt/Si/Ag nanowire diodes involves a scalable process including the formation of silicon nanowire array through wet chemical etching, electrodeposition of platinum and photoreduction of silver. The Pt/Si/Ag diodes exhibit highly efficient photocatalytic activity for a wide range of applications including environmental remediation and solar fuel production in the visible range. In this article, photodegradation of indigo carmine and 4‐nitrophenol are used to evaluate the photoactivity of Pt/Si/Ag diodes. The Pt/Si/Ag diodes also show high activity for photoconversion of formic acid into carbon dioxide and hydrogen.
Tuning the Composition and Nanostructure of Pt/Ir Films via Anodized Aluminum Oxide Templated Atomic Layer Deposition
Authors: Comstock David J. , Christensen Steven T. , Elam Jeffrey W. , Pellin Michael J. , Hersam Mark C.
Published: September 2010

Nanostructured metal films have been widely studied for their roles in sensing, catalysis, and energy storage. In this work, the synthesis of compositionally controlled and nanostructured Pt/Ir films by atomic layer deposition (ALD) into porous anodized aluminum oxide templates is demonstrated. Templated ALD provides advantages over alternative synthesis techniques, including improved film uniformity and conformality as well as atomic‐scale control over morphology and composition. Nanostructured Pt ALD films are demonstrated with morphological control provided by the Pt precursor exposure time and the number of ALD cycles. With these approaches, Pt films with enhanced surface areas, as characterized by roughness factors as large as 310, are reproducibly synthesized. Additionally, nanostructured PtIr alloy films of controlled composition and morphology are demonstrated by templated ALD, with compositions varying systematically from pure Pt to pure Ir. Lastly, the application of nanostructured Pt films to electrochemical sensing applications is demonstrated by the non‐enzymatic sensing of glucose.
Asymmetric Catalytic Reactions Using P*‐Mono‐, P*,N‐ and P*,P*‐Bidentate Diamidophosphites with BINOL Backbones and 1,3,2‐Diazaphospholidine Moieties: Differences in the Enantioselectivity
Authors: Gavrilov Konstantin N. , Zheglov Sergey V. , Rastorguev Eugenie A. , Groshkin Nikolay N. , Maksimova Marina G. , Benetsky Eduard B. , Davankov Vadim A. , Reetz Manfred T.
Published: September 2010

A new series of P*‐chiral diamidophosphites with 1,3,2‐diazaphospholidine rings, based on (Sa)‐ or (Ra)‐BINOL and their easily accessible derivatives, has been synthesized for the first time and tested in asymmetric transition metal catalysis. Up to 99% ee was achieved in the rhodium‐catalyzed asymmetric hydrogenation of functionalized olefins and in the palladium‐catalyzed allylic substitution. The influence of the nature of the donor atoms and denticity on the asymmetric induction is discussed. In addition, the first example of a successful platinum‐catalyzed asymmetric allylic amination (up to 86% ee) with participation of organophosphorus ligands is considered.
Feedstock handling and processing effects on biochemical conversion to biofuels
Authors: Inman Daniel , Nagle Nick , Jacobson Jacob , Searcy Erin , Ray Allison E.
Published: September 2010

Abating the dependence of the United States on foreign oil by reducing oil consumption and increasing biofuels usage will have far‐reaching global effects. These include reduced greenhouse gas emissions and an increased demand for biofuel feedstocks. To support this increased demand, cellulosic feedstock production and conversion to biofuels (e.g. ethanol, butanol) is being aggressively researched. Thus far, research has primarily focused on optimizing feedstock production and ethanol conversion, with less attention given to the feedstock supply chain required to meet cost, quality, and quantity goals. This supply chain comprises a series of unit operations from feedstock harvest to feeding the conversion process. Our objectives in this review are (i) to summarize the peer‐reviewed literature on harvest‐to‐reactor throat variables affecting feedstock composition and conversion to ethanol; (ii) to identify knowledge gaps; and (iii) to recommend future steps. © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd
Brazilian ethanol: an attractive proposition
Authors: Jagger Anna
Published: September 2010

With the consolidation of Brazil's sugarcane ethanol sector, increased production capacities, and lower operating costs, the Brazilian industry is seeing large‐scale companies enter the sector. It seems that these recent changes have benefitted the sector and helped the country strengthen its position as the world's second‐largest ethanol producer. Anna Jagger looks at the new partnerships being formed and at some of the plans Petrobras, BP, and Shell have for the future. © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd
Rectum-conserving surgery in the era of chemoradiotherapy
Authors: Smith F M , Waldron D , Winter D C
Published: September 2010

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 < 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

The 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

We 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

An 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

Terms 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

A 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

The 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

1,5‐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

A 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

The 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

The 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

Addition 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

The 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

2(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

The 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

Heterocyclizations 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

Starting 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

The 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

5‐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

Xanthate 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

Azomethine 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

The 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.
Thiolation with Dialkoxy Disulfanes ‐ a New Method for the Preparation of Dithioesters
Authors: Hoepping Alexander , Mayer Roland
Published: September 2010

CH‐acidic methyl groups can easily be converted into dithioesters by use of sulfur transfer reagents possessing a S2‐unit and two leaving groups. A possible mechanism is discussed.