bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for Fully Conjugated Double‐Stranded Cycles
Authors: Standera Malte , Häfliger Rolf , Gershoni‐Poranne Renana , Stanger Amnon , Jeschke Gunnar , van Beek Jacco D. , Bertschi Louis , Schlüter A. Dieter 
Published: September 2011

AbstractA chain of circumstantial evidence for the existence of the first fully conjugated, double‐stranded cycles is presented. The products have the structure of the belt‐region of fullerene C84 (D2) and carry either four hexyl chains or four phenyl groups. The unsubstituted parent cycle is also presented. The chain of evidence is mainly based on mass spectrometric analysis and trapping reactions, the latter being supported by quantum mechanical calculations. It is also of importance that the phenyl‐substituted and unsubstituted products cannot undergo a [1,5] hydrogen shift, the only reasonable side‐reaction that recently could not be excluded for the alkyl‐substituted analogue. It is concluded that the fully aromatic targets truly exist in the gas phase. Whether they can be generated in solution under the applied conditions cannot yet be firmly decided; theoretical evidence speaks against.
Neighboring‐Group Participation by C‐2 Ether Functions in Glycosylations Directed by Nitrile Solvents
Authors: Chao Chin‐Sheng , Lin Ching‐Yu , Mulani Shaheen , Hung Wei‐Cheng , Mong Kwok‐kong Tony 
Published: September 2011

AbstractEther‐protecting functions at C‐2 hydroxy groups have been found to play participating roles in glycosylations when the reactions are conducted in nitrile solvent mixtures. The participation mechanism is based on intramolecular interaction between the lone electron pair of the oxygen atom of the C‐2 ether function and the nitrile molecule when they are positioned in a cis configuration. A 1,2‐cis glycosyl oxazolinium intermediate is formed. This participation, in conjunction with the anomeric effect of the glycosyl donor, confers high 1,2‐trans selectivities on glycosylations. Further application of this concept has led to efficient preparations of α‐(1→5)‐arabinan oligomers.
Acetylene‐Expanded Dendralene Segments with Exotopic Phosphaalkene Units
Authors: Geng Xue‐Li , Ott Sascha 
Published: September 2011

AbstractBis‐TMS protected C,C‐diacetylenic phosphaalkene (A2PA) 1 (Mes*PC(C≡CTMS)2; Mes*=2,4,6‐tBu3Ph) has been used as a building block for the construction of butadiyne‐expanded dendralene fragments in which phosphaalkenes feature as exotopic double bonds. Treatment of 1 with CuCl gives rise to a CuI acetylide that is selectively formed at the acetylene trans to the Mes* group. The cis‐TMS‐acetylene engages in similar chemistry, albeit at higher temperatures and longer reaction times. The differentiation between the two acetylene termini of 1 allows for the controlled synthesis of the title compounds by a variety of different Cu‐ and Pd‐catalyzed oxidative acetylene homo‐ and heterocoupling protocols. Crystallographic characterization of A2PA 1 and dimeric Mes*PC(C≡CR1)C4(R2C≡C)CPMes* (3 b, R1=R2=Ph; 6, R1=R2=TMS), and 10 (R1=R2=C≡CPh) verifies that the stereochemistry across the PC bond is conserved during the coupling reactions, whereas spectroscopic evidence reveals cis/trans isomerization in an iodo‐substituted A2PA intermediate 4 (Mes*PC(C≡CTMS)(C≡CI). UV/Vis spectroscopic and electrochemical studies reveal that efficient π conjugation operates through the entire acetylenic phosphaalkene framework, even in the cross‐conjugated dimeric structures. The P centers contribute considerably to the frontier molecular orbitals of the compounds, thereby leading to smaller HOMO–LUMO gaps than in all‐carbon‐based congeners. Phenyl‐ and/or ethynylphenyl substituents at the A2PA framework influence the HOMO and LUMO to a varying degree depending on their relationship to the Mes* group, thus enabling a fine‐tuning of the frontier molecular orbitals of the compounds.
Discovery of a Pharmacologically Active Antagonist of the Two‐Pore‐Domain Potassium Channel K2P9.1 (TASK‐3)
Authors: Coburn Craig A. , Luo Yunfu , Cui Mingxiang , Wang Jiabing , Soll Richard , Dong Jingchao , Hu Bin , Lyon Michael A. , Santarelli Vincent P. , Kraus Richard L. , Gregan Yun , Wang Yi , Fox Steven V. , Binns Jacquelyn , Doran Scott M. , Reiss Duane R. , Tannenbaum Pamela L. , Gotter Anthony L. , Meinke Peter T. , Renger John J. 
Published: September 2011

AbstractTWIK‐related acid‐sensitive K+ (K2P9.1, TASK‐3) ion channels have the capacity to regulate the activity of neuronal pathways by influencing the resting membrane potential of neurons on which they are expressed. The central nervous system (CNS) expression of these channels suggests potential roles in neurologic disorders, and it is believed that the development of TASK‐3 antagonists could lead to the therapeutic treatment of a number of neurological conditions. While a therapeutic potential for TASK‐3 channel modulation exists, there are only a few documented examples of potent and selective small‐molecule channel blockers. Herein, we describe the discovery and lead optimization efforts for a novel series of TASK‐3 channel antagonists based on a 5,6,7,8‐tetrahydropyrido[4,3‐d]pyrimidine high‐throughput screening lead from which a subseries of potent and selective inhibitors were identified. One compound was profiled in detail with respect to its physical properties and demonstrated pharmacological target engagement as indicated by its ability to modulate sleep architecture in rodent electroencephalogram (EEG) telemetry models.
Salvage stereotactic radiosurgery for breast cancer brain metastases
Authors: Kelly Paul J. , Lin Nancy U. , Claus Elizabeth B. , Quant Eudocia C. , Weiss Stephanie E. , Alexander Brian M. 
Published: September 2011

AbstractBACKGROUND:Salvage stereotactic radiosurgery (SRS) is often considered in breast cancer patients previously treated for brain metastases. The goal of this study was to analyze clinical outcomes and prognostic factors for survival in the salvage setting.METHODS:The authors retrospectively examined 79 consecutive breast cancer patients who received salvage SRS (interval of >3 months after initial therapy), 76 of whom (96%) received prior whole‐brain radiation therapy. Overall survival (OS) and central nervous system (CNS) progression‐free survival rates were calculated from the date of SRS using the Kaplan‐Meier method. Prognostic factors were evaluated using the Cox proportional hazards model.RESULTS:Median age was 50.5 years. Fifty‐eight percent of this population was estrogen receptor positive, 62% was HER2 positive, and 10% was triple negative. At the time of SRS, 95% had extracranial metastases, with 81% of extracranial metastases at other visceral sites (lung/pleura/liver). Forty‐eight percent had stable extracranial disease. Median interval from initial brain metastases therapy to SRS was 8.4 months. Median CNS progression‐free survival after SRS was 5.7 months (interquartile range [IQR], 3.6‐11 months), and median OS was 9.8 months (IQR, 3.8‐18 months). Eighty‐two percent of evaluable patients received further systemic therapy after SRS. HER2 status (adjusted hazard ratio [HR], 2.4; P = .008) and extracranial disease status (adjusted HR, 2.7; P = .004) were significant prognostic factors for survival on multivariate analysis.CONCLUSIONS:In patients with good Karnofsky performance status, salvage SRS for breast cancer brain metastases is a reasonable treatment option, given an associated median survival in excess of 9 months. Furthermore, patients with HER2‐positive tumors at diagnosis or stable extracranial disease at the time of SRS have an improved clinical course, with median survival of >1 year. Cancer 2012. © 2011 American Cancer Society.
Identification of novel immunogenic human leukocyte antigen‐A*2402‐binding epitopes of human papillomavirus type 16 E7 for immunotherapy against human cervical cancer
Authors: Jang Sunphil , Kim Young Tae , Chung Hye Won , Lee Kyoung‐Ryul , Lim Jong‐Baeck , Lee Kyungwon 
Published: September 2011

AbstractBACKGROUND:A study was undertaken to identify new immunogenic human leukocyte antigen (HLA)‐A*2402‐restricted epitopes from human papillomavirus (HPV) type 16 E7 protein for immunotherapy against cervical cancer.METHODS:Synthetic overlapping peptides were screened by measuring the frequency of CD8+ cytotoxic T lymphocytes (CTLs) producing intracellular interferon‐γ (IFN‐γ) using flow cytometry and were validated in SiHa cells with a Cr release cytotoxicity assay. In vivo antitumor effects of peptide‐sensitized peripheral blood mononuclear cells (PBMCs) and isolated CD8+ CTLs were evaluated using BALB/c nude mice with SiHa cell xenotransplants.RESULTS:Among 14 overlapping 15‐amino acid peptides, E761‐75(CDSTLRLCVQSTHVD) and E767‐81(LCVQSTHVDIRTLED) induced significantly higher IFN‐γ production (P < .05) and showed higher in vitro cytotoxicity against SiHa cells than did cells sensitized with the negative control. To determine the exact HLA‐A*2402‐restricted epitopes, a total of 25 overlapping 9‐ or 10‐amino acid peptides spanning E761‐75 and E767‐81 were synthesized. E761‐69(CDSTLRLCV) and E767‐76(LCVQSTHVDI) induced significantly greater IFN‐γ production as well as increased in vitro cytotoxicity against SiHa cells compared with those of other peptides and the negative control (P < .01), and the antitumor effects of these peptide‐sensitized PBMCs were induced by CD8+ CTLs. E761‐69‐sensitized and E767‐76‐sensitized PBMCs and isolated CD8+ CTLs showed a much greater suppression of tumor growth in vivo compared with that of control groups treated with PBS (P < .01). The authors also confirmed the synergistic antitumor effect of cisplatin followed by E767‐76‐sensitized PBMCs in vivo.CONCLUSIONS:E761‐69 and E767‐76 were identified as novel HPV type 16 E7 epitopes for HLA‐A*2402, which could be used for immunotherapy against cervical cancer. Cancer 2012. © 2011 American Cancer Society.
Clinicopathologic characteristics of carcinomas that develop after a biopsy containing columnar cell lesions
Authors: Boulos Fouad I. , Dupont William D. , Schuyler Peggy A. , Sanders Melinda E. , Page David L. , Fedda Faysal A. , Simpson Jean F. 
Published: September 2011

AbstractBACKGROUND:Columnar cell lesions are frequently associated with atypical ductal hyperplasia, lobular neoplasia, and tubular carcinoma, and have been suggested as a precursor lesion for low‐grade carcinomas. However, in long‐term follow‐up studies, columnar cell lesions are associated with only a slight increase in later breast cancer development. If columnar cell lesions are precursor lesions, one would expect subsequent cancers to develop at the same site as the biopsy and to be preferentially of low grade. The goal of this article is to review the clinical and pathologic features of carcinomas that develop after a diagnosis of columnar cell lesion to try to establish whether these lesions are precursors to low‐grade invasive carcinoma.METHODS:The authors reviewed biopsies containing columnar cell lesions, using the criteria of Schnitt and Vincent‐Salomon, from 77 women in the Nashville Breast Cohort who developed subsequent breast carcinoma. Clinicopathologic features including laterality, type, and grade of the subsequent cancer were recorded.RESULTS:Breast cancer developed a median of 11 years after initial biopsy. The median age at diagnosis was 60 years. The majority of invasive carcinomas were of no special type and of intermediate grade. Moreover, the carcinomas were as likely to occur in the contralateral breast as in the breast that was originally diagnosed with columnar cell lesion, regardless of columnar cell lesion subtype (P = .48).CONCLUSIONS:Carcinoma subsequent to columnar cell lesions may occur in either breast and tends to show a similar grade and type distribution as sporadic breast cancer. These findings argue against columnar cell lesions being a true precursor for low‐grade invasive carcinoma. Cancer 2012. © 2011 American Cancer Society.
Disparities in receipt of adjuvant radiation therapy after breast‐conserving surgery among the cancer‐reporting regions of California
Authors: Parise Carol A. , Bauer Katrina R. , Caggiano Vincent 
Published: September 2011

AbstractBACKGROUND:Incidence and mortality of breast cancer vary according to demographic factors such as age, race/ethnicity, socioeconomic status (SES), and geographic region. This study assesses the variation of these factors in the use of adjuvant radiation therapy (RT) after breast‐conserving surgery (BCS) among 8 regions of California.METHODS:The authors identified 85,574 cases of first primary female invasive breast cancer with complete data diagnosed between January 1, 2000 and December 31, 2007. Logistic regression was used to determine the association between race/ethnicity, age, SES, and receipt of RT after BCS within each of the regions of California. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed.RESULTS:Age was a significant predictor of receipt of RT after BCS in all regions. In Los Angeles (LA), lower SES was associated with decreasing odds of RT. Racial disparities were evident only in LA, where black (OR, 0.85; 95% CI, 0.74‐0.97) and Hispanic (OR, 0.86; 95% CI, 0.78‐0.96) women were about 15% less likely to receive RT than white women.CONCLUSIONS:Racial disparities in the receipt of RT after BCS exist only in LA, where African American and Hispanic women are less likely to receive this form of adjuvant treatment. Lower SES was also associated with a reduced likelihood of receipt of RT in LA. Women age 70 years and older are less likely to receive RT after BCS in all regions of California. Cancer 2012. © 2011 American Cancer Society.
Semi‐implicit numerical modeling of axially symmetric flows in compliant arterial systems
Authors: Casulli Vincenzo , Dumbser Michael , Toro Eleuterio F. 
Published: September 2011

SUMMARYBlood flow in arterial systems is described by the three‐dimensional Navier–Stokes equations within a time‐dependent spatial domain that accounts for the viscoelasticity of the arterial walls. These equations are simplified by assuming cylindrical geometry, axially symmetric flow, and hydrostatic equilibrium in the radial direction. In this paper, an efficient semi‐implicit method is formulated in such a fashion that numerical stability is obtained at a minimal computational cost. The resulting computer model is relatively simple, robust, accurate, and extremely efficient. These features are illustrated on nontrivial test cases where the exact analytical solution is known and by an example of a realistic flow through a complex arterial system. Copyright © 2011 John Wiley & Sons, Ltd.
Intrinsic Viscosities of Polyelectrolytes: Determination and Modeling of the Effects of Extra Salt
Authors: Eich Andreas , Wolf Bernhard A. 
Published: September 2011

AbstractBased on early measurements of J. J. Hermans and co‐workers (D. T. F. Pals, J. J. Hermans, Recl. Trav. Chim. Pays‐Bas 1952, 71, 513–520; D. T. F. Pals, J. J. Hermans, J. Polym. Sci. 1950, 5, 733–734; D. T. F. Pals, J. J. Hermans, J. Polym. Sci. 1948, 3, 897–898), the present contribution demonstrates how primary data should be evaluated in order to obtain reliable intrinsic viscosities. This procedure yields detailed information on the changes of the intrinsic viscosities and of the corresponding viscometric interaction parameters caused by an increasing salinity of water. Both quantities decline from a maximum value in the pure solvent to a minimum value, which is approached in the limit of sufficiently high salt concentrations, and can be modeled quantitatively by means of a Boltzmann sigmoid. Particular attention is paid to the significance of results obtained by means of the method of isoionic dilution, proposed by J. J. Hermans and co‐workers.
Performance analysis of dynamic channel allocation based on the greedy approach for orthogonal frequency‐division multiple access downlink systems
Authors: Oh Eunsung , Woo Choongchae 
Published: September 2011

SUMMARYThis paper presents a performance analysis of dynamic channel allocation (DCA) based on the greedy approach (GA) for orthogonal frequency‐division multiple access downlink systems over Rayleigh fading channels. The GA‐based DCA achieves its performance improvement using multiuser diversity. We analyze the statistics of the number of allocable users that represents the multiuser diversity order at each allocation process. The derived statistics are then used to analyze the performance of GA‐based DCA. The analysis results show that the number of subcarriers allocated to each user must be equal to achieve the maximum system performance based on outage probability and data throughput. Copyright © 2011 John Wiley & Sons, Ltd.
In vitro metabolism of tiletamine, zolazepam and nonbenzodiazepine sedatives: Identification of target metabolites for equine doping control
Authors: Fenwick Susanna J. , Scarth James P. 
Published: September 2011

AbstractWithin horseracing, the detection of prohibited substance doping often requires urine analysis; hence, it is necessary to understand the metabolism of the drugs in question. Here, the previously unknown equine metabolism of eight sedatives is reported in order to provide information on target metabolites for use in doping control. Phase I metabolite information was provided by incubation with equine liver S9 fraction. In vitro techniques were chosen in order to reduce the ethical and financial issues surrounding the study of so many compounds, none of which are licensed for use in horses in the UK.Several metabolites of each drug were identified using liquid chromatography‐high resolution mass spectrometric (LC‐HRMS) analysis on an LTQ‐Orbitrap. Further structural information was obtained by tandem mass spectrometry (MS/MS) analysis; allowing postulation of the structure of some of the most abundant in vitro metabolites. The most abundant metabolites of alpidem, etifoxine, indiplon, tiletamine, zaleplon, zolazepam, zolpidem, and zopiclone related to hydroxylation/N‐oxidation, deethylation, demethylation, deethylation, hydroxylation/N‐oxidation, demethylation, hydroxylation/N‐oxidation and hydroxylation/N‐oxidation, respectively. In many cases, further work would be required to fully elucidate the precise positioning of the functional groups involved.The results of this study provide metabolite information that can be used to enhance equine anti‐doping screening methods. However, the in vitro metabolites identified are at present only a prediction of those that may occur in vivo. In the future, any positive findings of these drugs and/or their metabolites in horse urine samples could help validate these findings and/or refine the choice of target metabolites. Copyright © 2011 John Wiley & Sons, Ltd.
Differential role for CD277 as a co‐regulator of the immune signal in T and NK cells
Authors: Messal Nassima , Mamessier Emilie , Sylvain Aude , Celis‐Gutierrez Javier , Thibult Marie‐Laure , Chetaille Bruno , Firaguay Guylène , Pastor Sonia , Guillaume Yves , Wang Qian , Hirsch Ivan , Nunès Jacques A. , Olive Daniel 
Published: September 2011

AbstractThe human butyrophilin (BTN) 3 or CD277 molecules belong to the B7 family members and are expressed in various immune cells such as T and NK cells. Here, we show that CD277 triggering considerably enhances TCR‐induced cytokine production and cell proliferation, even when another co‐stimulatory molecule, CD28, is engaged. These CD277‐induced additive functional effects are in accordance with the detection of early T‐cell activation events such as TCR‐induced cell signaling being increased upon CD277 engagement. However, we found that CD277 triggering is not involved in CD16‐ or NKp46‐induced NK cell activation. BTN3/CD277 comprises three structurally related members, BTN3A1, BTN3A2 and BTN3A3. CD277 antibodies recognize all isoforms and we describe a differential expression of BTN3 isoforms between T and NK cells that could explain differential CD277 functions between T and NK cells. Our results show that, while T cells express all BTN3/CD277 transcripts, NK cells express mostly BTN3A2, which lacks the B30.2 intracellular domain. Furthermore, NKp30‐induced cytokine production is decreased by the specific engagement of BTN3A2, but not by BTN3A1 triggering. Thus, we provide new insights into the CD277 co‐stimulatory pathway that may differentially participate in the regulation of various cell‐mediated immune responses.
Putting the Anion into the Cage – Fluoride Inclusion in the Smallest Trisimidazolium Macrotricycle
Authors: Amendola Valeria , Boiocchi Massimo , Fabbrizzi Luigi , Fusco Nadia 
Published: September 2011

AbstractThe trisbenzimidazolium cyclophane receptor 23+ incorporates the F– anion in MeCN solution, which was inferred by spectrophotometric and 1H NMR titration experiments, with an association constant log K > 7. On the basis of geometric considerations, it is assumed that F– lies in the middle of the triangle 3C, whose vertices are the carbon atoms of the three imidazolium C–H fragments, and profits from three C–H···F H‐bonds. No other anion is encapsulated by 23+ for reasons of size. The parent trisbenzimidazolium tripodal receptor 43+ does not exert size exclusion selectivity and forms 1:1 complexes not only with F–, but also with other mono‐ (Br–) and polyatomic anions (NO3–). X‐ray diffraction studies on [4···Br]2+ and [4···NO3]2+ complexes indicated that, due to the steric restraints of the tripodal receptor, the anion is not positioned in the middle of the 3C triangle but stays below it, profiting from H‐bonds. Cage effects are observed in the higher thermodynamic stability of the [2···F]2+ complex with respect to [4···F]2+ and in its resistance to excess F–. In fact, on addition of excess fluoride, the tripodal [4···F]2+ complex decomposes with deprotonation of a C–H fragment and formation of the very stable HF2– complex.
A Combined Vinylogous Mannich/Diels–Alder Approach for the Stereoselective Synthesis of Highly Functionalized Hexahydroindoles
Authors: Ruff Bettina M. , Zhong Sabilla , Nieger Martin , Sickert Marcel , Schneider Christoph , Bräse Stefan 
Published: September 2011

AbstractA versatile strategy for the formation of hydroindole derivatives is reported. The molecules synthesized are highly functionalized and bear up to six stereogenic centers. We were able to develop a stereoselective route starting from nonchiral commercially available materials. Key steps in the formation of the bicyclic products are an organocatalytic vinylogous Mukaiyama–Mannich and a Diels–Alder reaction. The former uses a 1,1′‐bi‐2‐napthol (BINOL)‐based chiral Brønsted acid catalyst to build the first stereogenic center. The [4+2] cycloaddition proceeds highly diastereoselectively and furnishes one main stereoisomer, which represents the scaffold of the mycotoxins Rostratin B–D. Other transformations include iodolactonization, a Curtius rearrangement, additions, oxidations, and reductions.