bluuebunny/crossref_metadata_2025 huggingface dataset:
Remarkably Slow Rotation about a Single Bond between an sp3‐Hybridised Carbon Atom and an Aromatic Ring without ortho Substituents
Authors: Murrison Sarah , Glowacki David , Einzinger Christian , Titchmarsh James , Bartlett Stephen , McKeever‐Abbas Ben , Warriner Stuart , Nelson Adam
Published: January 2009

Look, no ortho substituents! A series of polycycles were prepared by using a three‐component Joullié–Ugi reaction. The rate of rotation about the bond between a highly hindered bridgehead and a phenyl ring with no ortho substituents was measured, and was highly dependent on the substitution. Rotamer half‐lives of up to 21 h at 298 K were observed (see figure). Rotamers resulting from this restricted rotation were isolated for the first time.

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A series of polycycles was prepared by using a three‐component Joullié–Ugi reaction. The rate of rotation about the bond between a highly hindered bridgehead and a phenyl ring with no ortho substituents was measured by using, in general, variable‐temperature HPLC. The rate of rotation was highly dependent on substitution and rotamer half‐lives of up to 21 h at 298 K were observed. Insights into the effect of substitution on the rate of rotation were gleaned through electronic structure calculations on closely related derivatives. Rotamers resulting from restricted rotation about a bond between an sp3‐hybridised carbon atom and a phenyl ring with no ortho substituents were isolated for the first time, and the equilibration of the separated rotamers was followed by using analytical HPLC. It was demonstrated, for the first time, that a highly hindered environment for the sp3‐hybridised atom is sufficient for slow bond rotation about a single bond between sp3‐ and sp2‐hybridised carbon atoms.
para‐Functionalized Aryl‐di‐tert‐butylfluorosilanes as Potential Labeling Synthons for 18F Radiopharmaceuticals
Authors: Iovkova Ljuba , Wängler Björn , Schirrmacher Esther , Schirrmacher Ralf , Quandt Gabriele , Boening Guido , Schürmann Markus , Jurkschat Klaus
Published: January 2009

Broad spectrum: Novel para‐functionalized aryl‐di‐tert‐butylfluorosilanes, p‐(tBu2FSi)C6H4X (X=functional group), have been made available and broaden the spectrum of silicon‐based 18F acceptors (SiFAs) for potential PET applications. For example, the [18F]maleimido derivative 1 has been employed for the synthesis of [18F]1‐ labeled rat serum albumin (RSA), the applicability of which for PET has been verified by in vivo experiments.

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The syntheses of the functionalized triorganofluorosilanes tBu2(p‐XC6H4)SiF (3 a, X=SH; 4 a, X=NCS; 4 b, X=NCO; 5, X=NC4H2O2; 7, X=COOH; 8 a, X=COONC4H4O2; 8 b, X=COOC6F5) are reported. These compounds display potential as silicon‐based fluoride acceptors (SiFAs). The molecular structures of compounds 5, 7, and 8 a have been determined by single‐crystal X‐ray diffraction studies. With the exception of compounds 8 a and 8 b, all of the compounds could be 18F‐labeled by isotopic exchange in good to high radiochemical yields (RCY) with good to excellent specific activities. As proof of applicability, the maleimido‐functionalized SiFA derivative 5, which is specific for thiol groups, has been used for the labeling of rat serum albumin (RSA) that had been derivatized with 2‐iminothiolane. The incorporation of [18F]5 into the derivatized RSA reached a maximum yield after 30 min at ambient temperature. After purification, the [18F]RSA was evaluated in a healthy rat by means of μPET and displayed an expedient in vivo stability over 180 min.
Organische Synthese im Mikroreaktor – Heterogen katalysierte Epoxidierung von 1,3‐Butadien
Authors: Otto T. , Pfeifer P. , Pitter S. , Powietzka B.
Published: January 2009

Diese Arbeit untersucht die Machbarkeit der Ag‐katalysierten Epoxidierung von 1,3‐Butadien (1,3‐BD) zu 3,4‐Epoxy‐1‐buten (EpB) in einem am Forschungszentrum Karlsruhe entwickelten Mikroreaktor (MR) [1]. Für Vorversuche kommt ein Rohrreaktor (RR) zum Einsatz. Als Katalysator wird ein α‐Al2O3‐Träger eingesetzt, auf dem die Aktivkomponenten aufgebracht sind. Die Epoxidierung erfolgt im Bereich von 180 °C bis 320 °C und Raumgeschwindigkeiten (RG) von 2950 h–1 bis 17 701 h–1 bei Umgebungsdruck in einem Katalysatorteststand. Die höchste EpB‐Selektivität von 52 % wird bei einem 1,3‐BD‐Umsatz von 2,1 % und einer RG von 8851 h–1 mit mikrostrukturierten Ti‐Folien bei 240 °C erreicht.
A Novel MALDI Matrix for Analyzing Peptides and Proteins: Paraffin Wax Immobilized Matrix
Authors: WEI Yuanlong , MEI Yuan , XU Zhe , WANG Cuihong , GUO Yinlong , DU Yiping , ZHANG Weibing
Published: January 2009

A new kind of MALDI matrix, termed paraffin wax immobilized matrix, was used to study peptide mixtures and proteins. During the preparation process, the paraffin wax was heated and coated on the stainless‐steel target plate, and then 2,5‐dihydrobenzoic acid (DHB) was deposited on the paraffin layer and stainless‐steel target plate to obtain different kinds of matrix spots. The morphology of matrices on different supports and peptide‐matrix co‐crystallization were observed by a high resolution digital‐video microscopy system. Peptide mixtures and bovine serum albumin (BSA) digests were used to investigate the performance of the immobilized matrices on the paraffin target. The MALDI‐FTMS analysis results also showed that the detection sensitivity of matrices immobilized in the paraffin sample support was better than that on other sample supports.
Probing the Subunit‐Subunit Interaction of the Tetramer of E. coli KDO8P Synthase by Electrospray Ionization Mass Spectrometry
Authors: LI Zhili , SAU Apurba Kumar
Published: January 2009

Escherichia coli 3‐Deoxy‐D‐manno‐octulosonate 8‐phosphate (KDO8P) synthase catalyzes the condensation reaction between D‐arabinose 5‐phosphate (A5P) and phosphoenolpyruvate (PEP) to form KDO8P and inorganic phosphate (Pi). This enzyme exists as a tetramer in solution, which is important for catalysis. Two different states of the enzyme were obtained: i) PEP‐bound and ii) PEP‐unbound. The effect of the substrates and products on the overall structure of KDO8P synthase in both PEP‐bound and unbound states was examined using electrospray ionization mass spectrometry. The analysis of our data showed that the complexes of the PEP‐unbound enzyme with PEP (or Pi) favored the formation of monomers, while the complexes with A5P (or KDO8P) mainly favored dimers. The PEP‐bound enzyme was found to exist in the monomer and dimer with a small amount of the tetramer, whereas the PEP‐unbound form primarily exists in the monomer and dimer, and no tetramer was observed, suggesting that the bound PEP have a role in stabilization of the tetrameric structure. Taken together, the results imply that the addition of the substrates or products to the unbound enzyme may alter the subunit‐subunit interactions and/or conformational change of the protein at the active site, and this study also demonstrates that the electrospray ionization mass spectrometric method may be a powerful tool in probing the subunit‐subunit interactions and/or conformational change of multi‐subunit protein upon binding to ligand.
Dynamic Covalent Self‐Assembly of Mono‐, Bi‐ and Trimacrocycles from Hydrogen Bonded Preorganized Templates
Authors: LIN Jianbin , WU Jing , JIANG Xikui , LI Zhanting
Published: January 2009

This paper describes the dynamic covalent assembly of three mono‐, bi‐ and trimacrocycles by utilizing hydrogen bonding‐driven zigzag anthranilamides as "leading" components. The monomacrocycle, a tetraamino molecule, was prepared from the [2+2] coupling reaction of a "U"‐shaped dialdehyde and a porphyrin diamine, followed by the reduction of the macrocyclic tetraimine by NaBH3CN, while the bi‐ and trimacrocycles were obtained through two six‐component coupling reactions with rigid tri‐ and tetraamino‐appended oligomers as templates.
Synthesis and Absolute Configuration of the Diynediol from Psathyrella scobinacea
Authors: WU Jianzhong , WU Yikang , JIAN Yajun , ZHANG Yihua
Published: January 2009

All the four isomers of Scobidiynediol (hepta‐4,6‐diyne‐2,3‐diol), a natural product isolated from white‐rot fungus Psathyrella scobinacea, were synthesized using either (R)‐ or (S)‐lactate as the source of chirality. The relative configurations of the diols were established by NOE experiments performed on the cyclic acetonides. The relative as well as absolute configurations of the natural Scobidiynediol was assigned as (2S,3S) through comparison of the optical rotation and 1H NMR data.
Synthesis of Tonghaosu Analogues
Authors: SUN Hai , LIN Yingjie , WU Yulin , WU Yikang
Published: January 2009

Several new analogues of natural antifeedant tonghaosu were synthesized via m‐CPBA (m‐chloroperoxybenzoic acid) oxidation of corresponding 3‐(α‐furyl)propanols, Luche reduction of the resulting enone, epoxidation, acid‐ mediated spiroketalization, and radical mediated dehydration.
KF‐Montmorillonite‐catalyzed Michael Addition Reaction of Malononitrile to α,β‐Unsaturated Ketones
Authors: SHI Daqing , WU Nan , ZHUANG Qiya
Published: January 2009

The Michael addition reaction of α,β‐unsaturated ketones with malononitrile catalyzed by KF‐montmorillonite was investigated. It was interesting to note that at different reaction temperatures the addition and cycloaddition reaction products were obtained. This method has the advantages of good yields, mild reaction conditions, easy work‐up and inexpensive reagents over the existing procedures.
Improvement of Hydrophobicity of Ionic Liquids by Partial Chlorination and Fluorination of the Cation
Authors: TAN Kuilong , LI Chunxi , MENG Hong , WANG Zihao
Published: January 2009

Two novel hydrophobic ionic liquids (IL) with partial substitution of chlorine and fluorine in the 1‐butyl‐3‐methylimidazolium cation (noted as [BMIM] or [C8H15N2] hereafter), viz. [C8H12.28Cl0.96F1.76N2]Cl and [C8H12.75Cl1.58F0.67N2][PF6], were reported, which were prepared from the precursors [BMIM]Cl and [BMIM][PF6], respectively through chlorination with chlorine gas and fluorination with potassium fluoride. The position of the chlorine substitution in the resulting IL was identified using proton nuclear magnetic resonance (1H NMR). The results showed that chlorination mainly took place in the imidazolium ring and partly in the methyl of butyl group. Moreover, the physico‐chemical properties of the resulting IL were measured experimentally including thermal stability, viscosity, and mutual solubility with water. It is showed that the hydrophobic property and viscosity of the IL [C8H12.28Cl0.96F1.76N2]Cl and [C8H12.75Cl1.58F0.67N2][PF6] increased greatly while the decomposition temperature decreased to some extent compared to their corresponding non‐modified IL [C8H15N2]Cl and [C8H15N2][PF6]. This study proposed an alternative and cost‐effective approach for tuning the hydrophobic property of IL.
A Concise Synthesis of (−)‐Indolizidines 209D and 209B
Authors: WU Hao , YU Menglong , ZHANG Yazhu , ZHAO Gang
Published: January 2009

A general stereoselective synthetic route to 5‐substituted and 5,8‐disubstituted indolizidine alkaloids has been developed starting from commercially available L‐proline. (−)‐Indolizidines 209D and 209B were efficiently synthesized in 9.8% and 14.8% overall yields in seven and five‐step reactions from readily available aldehyde 3 and ketone 10, respectively. The key steps of this synthesis involve a substrate‐induced asymmetric addition of ethyl lithiopropiolate to aldehyde 3 or methyl ketone 10, and a two‐step one‐pot hydrogenation/cyclization sequence to construct the bicyclic skeleton.
Synthesis of Small Peptides and Their Use as Bifunctional Chelating Agents in Diagnostic Radiopharmaceuticals
Authors: TANG Chongzhi , LI Longjin , PANG Zhen , YUAN Zhibin
Published: January 2009

Three linear mercaptoacetyl tetrapeptides, MAG3‐Leu‐OH, MAG3‐Phe‐OH and MAG3‐Tyr‐OH, were synthesized via a liquid phase synthetic approach with high yields and high purities without using preparative HPLC technique. The obtained products could be radiolabeled easily with 99mTc under a mild condition and showed high stability in vitro and in vivo conditions. The scintigrams of the tested rabbit after injection of the radiolabeled products via mainline showed a normal biodistribution, which is definitely different from that of 99mTc‐MAG3, indicating different routes of metabolization between these two radiochemicals.
Selective Colorimetric Fluoride Sensor: A Heteroditopic Receptor Combining Pyrrolic Amide with Urea
Authors: YIN Zhenming , LIU Shangyuan
Published: January 2009

A heteroditopic anion receptor, bearing one pyrrolic amide site and a urea site, has been synthesized. UV‐Vis spectrum studies in CH3CN solution revealed that the receptor had higher anion binding ability than the homoditopic one. A naked‐eye detectable color change, from colorless to yellow, of the receptor solution took place when fluoride was added, which indicates that the receptor has potential application to selective colorimetric fluoride sensing.
Theoretical Study on Mechanism of Hydroformylation of Ethene Catalyzed by a Heterobimetallic Rh(I)‐Cr Complex
Authors: TANG Dianyong , ZHANG Yuanqin , HU Changwei
Published: January 2009

The mechanism of ethene hydroformylation catalyzed by a heterobimetallic complex HRh(CO)(PH3)(µ‐PH2)2‐ Cr(CO)4 was investigated by density functional theory (DFT). Both the associative and dissociative mechanisms were studied, and the results were compared. It was found that the introduction of Cr(CO)4 moiety did not remodel the mechanism of hydroformylation of simple alkenes. The dissociative mechanism is predominant. The carbonyl insertion is the rate‐limiting step for the whole catalytic cycle with a free energy barrier of 91.15 kJ/mol at 298.15 K and 101.325 kPa. The aldehyde elimination step was predicted to be irreversible. These results are in good agreement with the previous theoretical and experimental studies.
Salicylate‐selective Potential Response of an Electrode Based on a Copper(II)‐phthalocyanine Derivative as an Ionophore
Authors: XU Wenju , YUAN Ruo , CHAI Yaqin
Published: January 2009

Selectivity properties were established for salicylate‐selective electrodes prepared by incorporating 2,9,16,23‐copper(II)‐tetranitrophthalocyanine (Cu(II)TNPc) and 2,9,16,23‐copper(II)‐tetraaminophthalocyanine (Cu(II)TAPc) into plasticized poly(vinyl chloride) (PVC) membranes. The effect of nature of plasticizer, concentrations of ionophore and anionic and cationic additives on the potential response of the electrode was investigated. The PVC membrane electrode based on Cu(II)TNPc exhibited preferential selectivity for salicylate (Sal−) over other tested anions. The best potential response characteristics of a wide working concentration range 1.0×10−1–9.0×10−7 mol·L−1 and a limit of detection of 7.2×10−7 mol·L−1 with a slope of (−59.8±0.5) mV/decade were observed for the membrane containing (w/w) 3.0% Cu(II)TNPc, 67.0% o‐NPOE, 29.5% PVC, and 0.5% NaTPB. The proposed electrode with good stability and fast response could be used over a pH range of 3.0–7.0. And it was successfully applied to the determination of salicylate in actual samples with satisfactory results.
Auf malerischem Weg zur Chemie
Authors: Tomcin Romy , Reiners Christiane S.
Published: January 2009

Das Methodenwerkzeug Chemie‐Foto‐Storys ist eine alternative Form des Versuchsprotokolls, das im Chemieanfangsunterricht eingesetzt und erprobt wurde. In diesem Beitrag sollen die Ergebnisse einer Fallstudie vorgestellt und mögliche Vorteile gegenüber dem üblichen Versuchsprotokoll diskutiert werden.
Experimentierkastensystem „NAWIlino‐Box”︁
Authors: Bröll Leena , Friedrich Jens , Oetken Marco
Published: January 2009

Seit der Lehrplanreform im Jahr 2004 wird im Bildungsplan für Grundschulen in Baden‐Württemberg zur Stärkung naturwissenschaftlicher Themenfelder explizit die Erarbeitung bestimmter naturwissenschaftlicher Inhalte gefordert. Ähnliche Forderungen finden sich auch in den Bildungsplänen anderer Bundesländer.

Untersuchungen [z. B. 1, 2, 3, 4] haben gezeigt, dass diese Forderungen nur bedingt in die Realität umgesetzt werden können; neben einer im Grundschullehramt häufig nur unzureichend stattfindenden naturwissenschaftlichen Ausbildung und einer häufig nicht zufrieden stellenden materiellen Ausstattung der Grundschulen mangelt es vor allem an einem hinreichenden Fortbildungsangebot für naturwissenschaftliche Aus‐ und Weiterbildung im Primarbereich.

Hinsichtlich dieser Defizite wurde in der Abteilung Chemie der Pädagogischen Hochschule Freiburg im Rahmen der Aktivitäten um das Schülerlabor NAWIlino ein Experimentierkastensystem entwickelt, mit dem sich knapp 100 Experimente zu verschiedenen naturwissenschaftlichen Themenbereichen durchführen lassen. Im Rahmen von mehrtägigen Lehrerfortbildungen setzen sich die Lehrkräfte anhand des Experimentierkastensystems mit verschiedenen naturwissenschaftlichen Themenfeldern in Theorie und Praxis intensiv auseinander und bekommen im Anschluss die Experimentierbox für den weiteren Einsatz im Unterricht ausgehändigt.

Sowohl die Effektivität des Experimentierkastensystems als auch das angebotene Lehrerfortbildungskonzept werden in einer umfangreichen Langzeitstudie empirisch untersucht.
Die Untersuchung von Olivenöl im Chemieunterricht
Authors: Zimmermann Johannes , Teuscher Markus , Woest Volker
Published: January 2009

Olivenöl wird rein mechanisch ohne weitere Zusatzstoffe aus dem Fruchtfleisch der Olivensteinfrucht gewonnen und muss folglich nicht nachraffiniert werden. Es ist fruchtig, hat eine gewisse Schärfe, darf aber auch bitter sein und schmeckt zuweilen, je nach Klima, Boden und Reifegrad der Oliven, würzig oder mild, rassig oder fein, manchmal sogar mandelbitter [1].

Der Sektor Olivenöl wird in der EU durch eine Vielzahl von Verordnungen zur Produktion, zum Export und zur Vermarktung geregelt und ist zu einem der wichtigen Wirtschaftszweige für Europa geworden. Olivenöl wird außer als Nahrungsmittel auch für die Herstellung von Seifen und allgemein Kosmetika sowie für pharmazeutische Produkte verwendet [2, S. 29].

Zur qualitativen Charakterisierung von Olivenöl dienten früher chemische Kennzahlen, die durch moderne apparative Analysemethoden allerdings in den Hintergrund gedrängt wurden. Die aktuellen chemischen und sensorischen Prüfverfahren sind auf der Internetseite des Internationalen Olivenölrates (IOOC) http://www.internationaloliveoil.org zu finden. Aufgrund ihrer einfachen Durchführbarkeit bieten die wenig material‐ und arbeitsaufwändigen Untersuchungsmethoden der chemischen Kennzahlen aber eine gute Möglichkeit, mit dem Lebensmittel Olivenöl das Gebiet der Fette und fetten Öle im Chemieunterricht experimentell und analytisch beispielhaft zu behandeln.
Efficient Synthesis of Highly Active Phospha‐Isosteres of the Influenza Neuraminidase Inhibitor Oseltamivir
Authors: Carbain Benoit , Collins Patrick J. , Callum Lori , Martin Stephen R. , Hay Alan J. , McCauley John , Streicher Hansjörg
Published: January 2009

With a Hunsdiecker–Barton iododecarboxylation strategy, we converted the carboxylate group of the oseltamivir precursor into exemplary phosphonate monoesters. In all cases, Ki values towards influenza virus sialidase remained in the sub‐nanomolar range. We have thus made valuable structural space available for the design of novel oseltamivir‐based tools for influenza virus research.

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Diversity of participants in clinical trials in an academic medical center
Authors: Joseph Galen , Dohan Daniel
Published: January 2009

BACKGROUND:

Only 2.5% of adults and even fewer minorities participate in cancer therapeutic trials. Researchers have concluded that many barriers to participation stem from how recruitment is performed by clinician investigators. The objective of the current research was to document specifically how these barriers impede recruitment in the clinical setting.

METHODS:

The authors conducted a case study of recruitment in an academic medical center using ethnographic research methods (direct observation of provider‐patient interactions and in‐depth interviews with providers) to collect data. Qualitative data analysis was used to identify themes related to the provider's role in the recruitment processes.

RESULTS:

In the clinics that were studied, the authors observed that providers subjectively assessed which patients seemed to be ‘good study patients’ to target for recruitment. ‘Good study patients’ were identified as those who were able to adhere to complex trial protocols, thus helping clinician researchers to complete studies in a timely and efficient manner. These patients were perceived as meticulous, proactive, and compliant; they were considered good communicators; and they were embedded in the kinds of strong social support networks that facilitated their trials participation.

CONCLUSIONS:

The providers that were studied sought ‘good study patients’ for therapeutic trials because they wanted to perform studies in a timely and efficient manner. Future research should examine whether providers in other settings also target their recruitment efforts for this or other reasons. Further research also should consider whether differentially recruiting ‘good patients’ can impact the ethnic/racial diversity or other characteristics of trial participants in ways that may bias the outcomes or conclusions of therapeutic trials. Cancer 2009. © 2009 American Cancer Society.
Computed tomography scan‐driven selection of treatment for retroperitoneal liposarcoma histologic subtypes
Authors: Lahat Guy , Madewell John E. , Anaya Daniel A. , Qiao Wei , Tuvin Daniel , Benjamin Robert S. , Lev Dina C. , Pollock Ralphael E.
Published: January 2009

BACKGROUND:

Well differentiated (WD) and dedifferentiated (DD) retroperitoneal liposarcoma (RPLS) have distinct biologic behaviors. Consequently, the therapeutic approaches for these tumors differ and mandate an accurate preoperative diagnosis. The authors of this report evaluated whether computed tomography (CT) can be used to differentiate between WD and DD RPLS.

METHODS:

Imaging studies (CT, magnetic resonance imaging, and positron emission tomography‐CT) from 78 patients with RPLS who underwent surgery at the University of Texas M. D. Anderson Cancer Center (UTMDACC) between 2001 and 2007 were reviewed by a senior bone and soft tissue sarcoma radiologist who was blinded to the final histopathologic diagnosis. A focal nodular/water density area within an RPLS was interpreted as a marker suggestive of DD. Correlations between imaging diagnosis, histology, and clinical outcome were analyzed.

RESULTS:

The study radiologist identified 60 RPLS as DD and 17 RPLS as WD. A radiologic diagnosis of a WD was correlated with preoperative biopsy and postoperative histology in all patients (100%). Focal nodular/water density was a very sensitive marker of DD (97.8%); however, it had relatively low specificity (51.5%). Sixteen WD RPLS (48.5%) contained focal nodular/water density areas, leading to their misdiagnosis as DD; half of those tumors had hypercellular WD. Of 78 preoperative biopsies, 22 (28.2%) were performed at UTMDACC under CT guidance. Preoperative histologic diagnoses obtained from 12 biopsies derived from focal nodular/water density areas were confirmed as unchanged on final pathology; whereas, in 50% of biopsies that were not taken from a suspicious area, DD histology was misdiagnosed as WD.

CONCLUSIONS:

When CT features are suggestive of WD, no further diagnostic tests are needed for tumor characterization. Moreover, CT can accurately identify most DD, thereby rendering their under‐treatment unlikely; however, a CT‐guided biopsy is needed to differentiate between DD and WD RPLS that contain focal nodular/water density areas, thereby avoiding their over treatment. Cancer 2009. © 2009 American Cancer Society.
The atypical Spitz tumor of uncertain biologic potential
Authors: Ludgate Mathew W. , Fullen Douglas R. , Lee Julia , Lowe Lori , Bradford Carol , Geiger James , Schwartz Jennifer , Johnson Timothy M.
Published: January 2009

BACKGROUND:

Atypical Spitz tumors (AST) are rare spitzoid melanocytic proliferations with an uncertain malignant potential. ASTs have overlapping features of both Spitz nevi and spitzoid melanoma, and consequently generate controversy with diagnosis and management. Sentinel lymph node biopsy (SLNB) has been proposed as a possible means to gain additional insight into the true biologic potential of these tumors; however, previous reports on the use of SLNB in ASTs have been limited by small numbers of patients and short durations of follow‐up.

METHODS:

The authors extracted data from their institution's prospective melanoma database, collected between 1994 and 2007, for all patients with ASTs of uncertain biologic potential. They reviewed the clinical features of these patients, including the sentinel lymph node status, and the histological features of the tumors.

RESULTS:

A total of 67 patients with ASTs were identified, with a median age of 23.7 years. The mean depth was 2.4 mm. Of these, 57 had a SLNB performed, with 27 (47%) having a positive sentinel lymph node. SLNB‐positive cases had a significantly lower mean age than SLNB‐negative cases (17.9 vs 28.7 years; P = .013); however, no other significant differences were observed. All 27 patients with a positive SLNB were alive and disease free with median follow‐up of 43.8 months. One patient who did not receive a SLNB developed recurrent disease with regional and distant metastases.

CONCLUSIONS:

ASTs do not appear to behave like conventional melanoma. There is a high incidence of microscopic lymph node deposits in SLNBs, but despite this finding, patients have a favorable prognosis. Our findings raise several questions regarding the malignant potential of ASTs, and the role of SLNB in their management. Cancer 2009. © 2009 American Cancer Society.
O6‐methylguanine DNA methyltransferase immunoexpression in nonfunctioning pituitary adenomas
Authors: Widhalm Georg , Wolfsberger Stefan , Preusser Matthias , Woehrer Adelheid , Kotter Mark R. , Czech Thomas , Marosi Christine , Knosp Engelbert
Published: January 2009

BACKGROUND:

Currently, no effective alternative treatment exists for progressive, regrowing, nonfunctioning pituitary adenomas (NFPA) that are resistant to conventional multimodality therapy. Temozolomide (TMZ) was proposed as a treatment option for pituitary carcinomas and aggressive pituitary adenomas. Recently, it was suggested that the responsiveness of pituitary tumors to TMZ depends on the immunoexpression of O6‐methylguanine DNA methyltransferase (MGMT). Therefore, the authors of this report assessed MGMT expression in a series of patients with progressive, regrowing NFPAs to evaluate whether TMZ may serve as alternative treatment option.

METHODS:

On the basis of postoperative magnetic resonance imaging, 45 patients with NFPAs were allocated to either a group with progressive, regrowing tumors (n = 24) or a tumor‐free group (n = 21), which served as a control. MGMT expression was assessed semiquantitatively by immunohistochemistry (low expression was defined as ≤50% immunostained adenoma cells, and high expression was defined as >50% immunostained adenoma cells) and was compared between the 2 groups.

RESULTS:

At the time of initial surgery, low MGMT expression was observed in 12 of 24 patients (50%) in the study group with progressive, regrowing NFPAs. In the control group of tumor‐free patients, only 5 of 21 patients (24%) exhibited low MGMT expression. A comparable distribution of MGMT expression was observed in the specimens from repeat surgeries. A shorter interval to second surgery was observed in patients who had low MGMT expression.

CONCLUSIONS:

The current data has suggested that half of the patients with progressive, regrowing NFPAs exhibit low MGMT expression and are potential candidates for treatment with TMZ. These findings provide a rationale for the use of TMZ as an alternative treatment approach in this subgroup if conventional therapy, including reoperation, radiosurgery, and radiotherapy, fails. Cancer 2009. © 2009 American Cancer Society.
Locoregional recurrence of triple‐negative breast cancer after breast‐conserving surgery and radiation
Authors: Freedman Gary M. , Anderson Penny R. , Li Tianyu , Nicolaou Nicos
Published: January 2009

BACKGROUND:

The results of radiation on the local control of triple receptor‐negative breast cancer (negative estrogen [ER], progesterone [PR], and HER‐2/neu receptors) was studied.

METHODS:

Conservative surgery and radiation were used in 753 patients with T1‐T2 breast cancer. Three groups were defined by receptor status: Group 1: ER or PR (+); Group 2: ER and PR (−) but HER‐2 (+); and Group 3: triple‐negative (TN). Factors analyzed were age, menopausal status, race, stage, tumor size, lymph node status, presentation, grade, extensive in situ disease, margins, and systemic therapy. The primary endpoint was 5‐year locoregional recurrence (LRR) isolated or total with distant metastases.

RESULTS:

ER‐ and PR‐negative patients were statistically significantly more likely to be black, have T2 disease, have tumors detectable on both mammography and physical examination, have grade 3 tumors, and receive chemotherapy. There were no significant differences noted with regard to ER− and PR− patients by HER‐2 status. There was a significant difference noted in rates of first distant metastases (3%, 12%, and 7% for Groups 1, 2, and 3, respectively; P = .009). However, the isolated 5‐year LRR was not significantly different (2.3%, 4.6%, and 3.2%, respectively; P = .36) between the 3 groups.

CONCLUSIONS:

Patients with TN breast cancer do not appear to be at a significantly increased risk for isolated LRR at 5 years and therefore remain appropriate candidates for breast conservation. Cancer 2009. © 2009 American Cancer Society.
Incidence of bisphosphonate‐associated osteonecrosis of the jaws in breast cancer patients
Authors: Walter Christian , Al‐Nawas Bilal , du Bois Andreas , Buch Laura , Harter Philipp , Grötz Knut A.
Published: January 2009

BACKGROUND:

Bisphosphonate‐associated osteonecrosis of the jaws (BP‐ONJ) is a relatively new disease. The aim of this study was to evaluate the prevalence of BP‐ONJ in breast cancer patients with osseous metastasis and bisphosphonate therapy.

METHODS:

A retrospective study was conducted in a EUSOMA accredited breast unit in Germany. All patients treated from January of 2000 to March of 2006 with metastatic breast cancer and bisphosphonate therapy were reviewed. All patients were contacted, and missing data were completed through structured interviews with their dentists and physicians (n = 75). Primary outcome was the development of BP‐ONJ and the detection of possible additional trigger factors for the development of BP‐ONJ.

RESULTS:

A total of 117 patients with breast cancer fulfilled the inclusion criteria, and data for 75 still living patients were included. Of these 75, 4 patients developed a BP‐ONJ, resulting in a prevalence of 5.3%: 3 patients received zoledronate only; 1 patient had first pamidronate followed by zoledronate and ibandronate. A tooth extraction could be identified as an additional trigger factor for 2 patients.

CONCLUSIONS:

With a prevalence of 5.3%, BP‐ONJ in breast cancer patients has become a relevant disease that should be discussed with patients for whom bisphosphonates have been recommended. Appropriate dental care before bisphosphonate therapy commences has been advised to reduce the occurrence of BP‐ONJ. Cancer 2009. © 2009 American Cancer Society.
Frequent loss of heterozygosity of chromosome 1q in esophageal adenocarcinoma
Authors: Maru Dipen M. , Luthra Rajyalakshmi , Correa Arlene M. , White‐Cross Jill , Anandasabapathy Sharmila , Krishnan Sunil , Guha Sushovan , Komaki Ritsuko , Swisher Stephen G. , Ajani Jaffer A. , Hofstetter Wayne L. , Rashid Asif
Published: January 2009

BACKGROUND:

Previous microarray expression profiling studies have shown that genes located on chromosome region 1q21‐23 were down‐regulated in the progression of Barrett esophagus to esophageal adenocarcinoma and that, among patients with the latter condition, these genes were differentially expressed between responders and nonresponders of preoperative chemoradiation therapy. It was unclear whether this difference was due to loss of heterozygosity (LOH) or to other genetic alterations at this locus.

METHODS:

The status of chromosome 1q LOH was retrospectively evaluated in formalin‐fixed, paraffin‐embedded pretreatment biopsy specimens from 33 patients with locally advanced esophageal adenocarcinoma who were treated with preoperative neoadjuvant therapy, and the findings were correlated with clinicopathologic features and overall survival duration. LOH was determined by polymerase chain reaction analysis of 7 dinucleotide microsatellite markers that spanned chromosomal region 1q21‐23.

RESULTS:

Allelic loss of chromosome 1q with any marker was found in 66% of tumors; 58% of tumors demonstrated loss of chromosome 1q21, and 45% of tumors demonstrated loss of chromosome 1q23. Patients with loss of chromosome 1q21.3 had shorter overall survival duration than patients without loss of chromosome 1q21.3 (P = .02). The difference in survival with loss of the chromosome 1q21.3 region was also found to be significant in a subset of patients with incomplete pathologic response to preoperative therapy (P = .024).

CONCLUSIONS:

Loss of chromosome 1q was a frequent finding in esophageal adenocarcinoma cases, and loss of the 1q21.3 region was associated with shorter overall survival duration. Cancer 2009. © 2009 American Cancer Society.
Sugar fuels cancer
Authors: Penson Richard T.
Published: January 2009

Pre‐op plasma glucose is a prognostic factor in ovarian cancer, and may reflect important metabolic and oncogenic pathways that link obesity and cancer.
A Facile Method to Assemble PNIPAM‐Containing Microgel Photonic Crystals
Authors: Zhou Mi , Xing Fubao , Ren Meilin , Feng Yan , Zhao Yongqiang , Qiu Haixia , Wang Xiaodong , Gao Chunjuan , Sun Feifei , He Yongqiang , Ma Zhiqing , Wen Pu , Gao Jianping
Published: January 2009

Structural colors: Poly(N‐isopropyl acrylamide) based microgel photonic crystals are fabricated by using a new method called “high‐temperature‐induced hydrophobic assembly”. The assembling conditions affect the water content of the crystals, thus determining their structural color (see image). The obtained photonic crystals are sensitive to solvents, and the reversible changes in their color can be observed with the naked eye.

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Two‐Color Two‐Photon Excitation of Intrinsic Protein Fluorescence: Label‐Free Observation of Proteolytic Digestion of Bovine Serum Albumin
Authors: Quentmeier Stefan , Quentmeier Claudia C. , Walla Peter J. , Gericke Karl‐Heinz
Published: January 2009

Two into one: Simultaneous absorption of two photons of different colors (2c2p) extends the applicable wavelength range of the Ti:Sa laser beyond that of conventional two‐photon excitation (TPE) into the UV region (see schematic). The intrinsic fluorescence of bovine serum albumin during proteolytic cleavage by subtilisin (see plot) are monitored without exposing the protein to damaging UV radiation.

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Two‐color two‐photon (2c2p) excitation fluorescence is used to monitor the enzymatic cleavage of bovine serum albumin (BSA) by subtilisin. Fluorescence is generated by irradiation with spatially and temporally overlapping femtosecond laser beams resulting in simultaneous absorption of an 800 and a 400 nm photon. Thereby, excitation of the fluorescent amino acid tryptophan present in BSA corresponds to an effective one‐photon wavelength of 266 nm. The progress of protein cleavage is monitored by time‐resolved fluorescence analysis. The fluorescence lifetime of tryptophan decreases during the reaction. This demonstrates a novel label‐free multiphoton observation technique for conformational changes of proteins containing tryptophan. Due to the strong 2c2p fluorescence signal it is suitable for fast evaluation and monitoring of protein reactions. The course of the reaction is monitored simultaneously by gel electrophoresis. In contrast to conventional one‐photon techniques, 2c2p excitation enables label‐free protein fluorescence studies without irradiating the sample with UV light. Due to the dependence of the excitation on the power of both laser beams, excitation is limited to a relatively small focal volume. This results in dramatically reduced overall photodamage compared to direct UV irradiation. This method can be easily extended to microscopy imaging techniques.
A Theoretical Study on the Electronic States and O‐Loss Photodissociation of the NO2+ Ion
Authors: Chang Hai‐Bo , Huang Ming‐Bao
Published: January 2009

At a loss: CASPT2 geometry optimization calculations assign the eight low‐lying ionic states observed in the photoelectron spectra of NO2+. CASPT2 potential energy curves for O‐loss dissociation from the 11A′ (X1Σg+), 13A′ (a3B2), 13A′′ (b3A2), 11A′′ (A1A2), 21A′ (B1B2), and 23A′′ states of the NO2+ ion are shown in the figure.

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CASPT2 (multiconfiguration second‐order perturbation theory) calculations were performed at the molecular geometry for 17 low‐lying singlet and triplet states of the NO2+ ion. The CASPT2 vertical relative energies (Tv′) were obtained and the characters of these ionic states (primary or shake‐up ionization states) were determined. For the eight low‐lying states, we performed CASPT2 geometry optimization calculations and obtained the CASPT2 adiabatic relative energies (T0). We conclude that the 11A1, 13B2, 13A2, 11A2, 11B2, 13A1, 23B1, and 33B2 states of NO2+ correspond to the X1Σg+, a3B2, b3A2, A1A2, B1B2, c3A1, d3B1, and (3b2)−1 3B2 states (the eight ionic states below 20 eV observed in the photoelectron spectra of Brundle et al.1 and Baltzer et al.2), respectively. The 11A1, 13B2, 13A2, 11A2, 11B2, 13A1, and 33B2 states are primary ionization states, and the CASPT2 Tv′ and T0 values of these states are close to the corresponding experimental values from refs. [1] and [2]. The 23B1 state is not a typical primary ionization state, and the CASPT2 Tv′ and T0 values for 23B1 are in reasonable agreement with the experimental values for d3B1 from refs. [1] and [2] (the CASPT2 T0 value for 13B1 is more than 2.5 eV smaller than the experimental values). Based on our CASPT2 T0 calculations, we comment on the assignments of the d3A1, C1B1, and D1B2 states below 20 eV observed by Jarvis et al. and on the MRCI T0 values of Hirst for the 13B1, 11B1, and 3A1 states. On the basis of the CASPT2 potential energy curve (PEC) and CASSCF singlet/triplet minimum‐energy crossing point (MECP) calculations, we reach the following conclusions concerning O‐loss photodissociation from the X1Σg+, a3B2, b3A2, A1A2, and B1B2 states, which are in line with the experimental facts. The adiabatic dissociation process of the X1Σg+ state to the second limit [NO+(X1Σ+)+O(1D)] cannot occur due to a high energy barrier (>5.0 eV) along the PEC, and the nonadiabitic process of X1Σg+ to the first limit [NO+(X1Σ+)+O(3P)] via the triplet states is unlikely since the MECPs lie very high above X1Σg+. For the a3B2 and b3A2 states, adiabatic dissociation processes to the first limit may occur. Both the A1A2 and B1B2 states can undergo processes of predissociation to the first limit by a repulsive 23A′′ state, since the MECPs lie low above A1A2 and B1B2 and the calculated spin–orbit couplings at the MECPs are not small.
Epithelioid angiomyolipoma of the liver with striking giant cell component: Fine‐needle aspiration biopsy findings of a rare neoplasm
Authors: Alatassi Houda , Sahoo Sunati
Published: January 2009

Angiomyolipoma (AML) is a uncommon benign neoplasm of the liver with cyto‐ and histologic features similar to the more commonly encountered renal AML. Tumors composed predominantly of epithelioid cells have been referred to as epithelioid AML. Because most liver lesions are first evaluated by fine‐needle aspiration biopsy (FNAB), it is important to distinguish this variant of AML from more common hepatic neoplasms such as hepatocellular carcinoma (HCC) or metastatic tumors. Rare reports of epithelioid AML of the liver diagnosed by FNAB are in the literature. Here, we describe the cytologic findings of a unique case of epithelioid AML with numerous giant cells. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
Fine‐needle aspiration biopsy of a papillary thyroid carcinoma involved by malignant plasma cell disease: A case report
Authors: Bhanote Monisha , Vazquez Madeline F.
Published: January 2009

We described the fine‐needle aspiration biopsy findings in a case of papillary thyroid carcinoma involved by a malignant plasma cell disease of the thyroid gland in a 54‐year‐old female. Although papillary thyroid carcinoma is the most common malignant tumor of the thyroid gland, involvement by plasma cell disease is exceptionally unusual. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
Medullary thyroid carcinoma presenting as rectangular cell type on fine‐needle aspiration
Authors: Schreiner Andrew M. , Yang Grace C. H.
Published: January 2009

Medullary thyroid carcinoma typically presents as dyscohesive plasmacytoid, spindled, or polygonal cells on fine‐needle aspiration smears. We recently encountered a case of sporadic medullary thyroid carcinoma that presented as a hypercellular aspirate composed of cohesive aggregates of rectangle‐shaped cells. The case was mistakenly reported as a hypercellular follicular neoplasm on cytology. Subsequent thyroidectomy revealed medullary carcinoma. We draw attention to this distinctive rectangular cell type as an additional morphology for medullary thyroid carcinoma. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
Extranodal lymphomas: Review of clinicopathologic and cytologic features
Authors: Siddiqui Momin T. , Pitelka Lisa A. , Gattuso Paolo
Published: January 2009

Extranodal lymphomas can be challenging for a practicing cytopathologist, especially in the fine needle aspiration clinic setting. These lymphomas can vary in type from one extranodal site to another. A variety of these lymphomas have very specific clinicopathologic features. They also may be associated with underlying autoimmune diseases, immunodeficiency syndromes, infection, or be noted in unique ethnic communities. This article reviews some of the commonly encountered lymphomas in extranodal sites with an emphasis on clinicopathologic and cytologic features. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
Alkaline Earth Metal Salts of 5‐Nitro‐2H‐tetrazole: Prospective Candidates for Environmentally Friendly Energetic Applications
Authors: Klapötke Thomas M. , Sabaté Carles Miró , Welch Jan M.
Published: January 2009

Deprotonation of ammonium 5‐nitrotetrazolate in aqueous or alcoholic solution upon reaction with a suitable alkaline earth metal (M2+) hydroxide or carbonate (M2+ = Mg2+, Ca2+, Sr2+ or Ba2+) leads to the synthesis of a family of sensitive energetic metal salts based on the 5‐nitrotetrazolate anion (NT–). These new compounds were characterized by IR, Raman and NMR (1H, 13C and 14N) spectroscopy as well as by mass spectrometry and elemental analysis. In addition, the crystal structure of the calcium salt was determined by low‐temperature X‐ray measurements [orthorombic, space group Pna2; a = 6.8960(2), b = 32.575(1), c = 6.2399(2) Å; V = 1401.73(8) Å3]. All compounds show good thermal stabilities at or above 180 °C, as proved by DSC measurements, and the sensitivity of the salts towards impact and friction increases with the size of the cation (Mg < Ca < Sr < Ba). Lastly, the 5‐nitro‐2H‐tetrazole salts presented here show promise for future use as energetic compounds.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Operational stability of immobilised lipase/acyltransferase during interesterification of fat blends
Authors: Osório Natália Melo , Dubreucq Eric , da Fonseca Maria Manuela R. , Ferreira‐Dias Suzana
Published: January 2009

The lipase/acyltransferase from Candida parapsilosis is an unusual enzyme that preferably catalyses alcoholysis over hydrolysis in biphasic aqueous/organic media. The aim of this study was to evaluate the operational stability of an immobilised form of this enzyme during the interesterification of fat blends containing n‐3 polyunsaturated fatty acids, in solvent‐free media, at 60 °C, carried out continuously and batchwise. When the interesterification was performed in a continuous fluidised‐bed reactor, an operational half‐life of 9 h was estimated. The biocatalyst was also reused in consecutive 23‐h batches, in a total of four batches, either using fresh medium with no water addition or adding water to rehydrate the biocatalyst. When no water and extra water was added to the reaction medium, the obtained half‐lives were 10 and 18 h, respectively. Thus, the loss of activity may be explained by a progressive dehydration occurring along the reaction rather than by product or substrate inhibition effects. The interesterification activity was accompanied by changes in the acylglycerol profile. An increase in compounds of low equivalent carbon number (ECN) and in triacylglycerols (TAG) of ECN 42 and 44 was observed. This increase was accompanied by the consumption of TAG of ECN 46, 48 and 50.
Pronounced Catalytic Effect of a Micellar Solution of Sodium Dodecylsulfate (SDS) Upon a Three‐Component Reaction of Aldehydes, Amines, and Ketones Under Neutral Conditions
Authors: Jafari Abbas Ali , Moradgholi Fatemeh , Tamaddon Fatemeh
Published: January 2009

A micellar solution of anionic, cationic or neutral surfactants can be used as an excellent medium for three‐component Mannich reactions of aldehydes, amines, and ketones at room temperature. Sodium dodecylsulfate turned out to efficiently catalyze the reaction in neutral pure water (pH ≈ 7), and the corresponding desired β‐amino ketones precipitate while the reactions proceedes. This method provides a novel and improved modification of the three‐component Mannich reaction in terms of mild reaction conditions, clean reaction profile, improved yields, and excellent regio‐ and diastereoselectivities with a simple workup. Interesting examples of click chemistry under neutral conditions in water were observed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Screening and confirmatory methods for the analysis of macrocyclic lactone mycotoxins by CE with amperometric detection
Authors: Arribas Alberto Sánchez , Bermejo Esperanza , Zapardiel Antonio , Téllez Helena , Rodríguez‐Flores Juana , Zougagh Mohammed , Ríos Ángel , Chicharro Manuel
Published: January 2009

A simple analytical scheme for the screening and quantification of zearalenone and its metabolites, α‐zearalenol and β‐zearalenol, is reported. Extracts from maize flour samples were collected by supercritical fluid extraction and afterwards, they were analyzed by CE with amperometric detection. This scheme allowed a rapid and reliable identification of contaminated flour samples according to the reference value established for zearalenone by directive 2005/38/EC (200 μg/kg). The sample screening method was carried out by CZE using 25 mM borate separation buffer at pH 9.2 and 25.0 kV as separation voltage, monitoring the amperometric signal at +700 mV with a carbon paste electrode. In this way, total amount of mycotoxins was determined and samples were processed in 4 min with a detection limit of 12 μg/L, enough to discriminate between positive (more than 200 μg/L total mycotoxins) and negative samples (less than 200 μg/L total mycotoxins). Positive samples were then subjected to CZE separation and quantification of each analyte was done with 50 mM borate running buffer modified with 30% methanol at pH 9.7 and 17.5 kV as separation voltage. Under these conditions, separation was achieved in 15 min with detection limits from 20 to 35 μg/L for each analyte.