bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complexes of Monocationic Group 13 Elements with Pentaphospha‐ and Pentaarsaferrocene
Authors: Fleischmann Martin , Welsch Stefan , Krauss Hannes , Schmidt Monika , Bodensteiner Michael , Peresypkina Eugenia V. , Sierka Marek , Gröger Christian , Scheer Manfred 
Published: February 2014

AbstractReactions of the sandwich complexes [Cp*Fe(η5‐E5)] (Cp*=η5‐C5Me5; E=P (1), As (2)) with the monovalent Group 13 metals Tl+, In+, and Ga+ containing the weakly coordinating anion [TEF] ([TEF]=[Al{OC(CF3)3}4]−) are described. Here, the one‐dimensional coordination polymers [M(μ,η5:η1‐E5FeCp*)3]n[TEF]n (E=P, M=Tl (3 a), In (3 b), Ga (3 c); E=As, M=Tl (4 a), In (4 b)) are obtained as sole products in good yields. All products were analyzed by single‐crystal X‐ray diffraction, revealing a similar assembly of the products with η5‐bound E5 ligands and very weak σ‐interactions between one P or As atom of the ring to the neighbored Group 13 metal cation. By exchanging the [TEF] anion of 4 a for the larger [FAl] anion ([FAl]=[FAl{OC6F10(C6F5)}3]−), the coordination compound [Tl{(η5‐As5)FeCp*}3][FAl] (5) without any σ‐interactions of the As5‐ring is obtained. All products are readily soluble in CH2Cl2 and exhibit a dynamic coordination behavior in solution, which is supported by NMR spectroscopy and ESI‐MS spectrometry as well as by osmometric molecular‐weight determination. For a better understanding of the proceeding equilibrium DFT calculations of the cationic complexes were performed for the gas phase and in solution. Furthermore, the 31P{1H} magic‐angle spinning (MAS) NMR spectra of 3 a–c are presented and the first crystal structure of the starting material 2 was determined.
Unusual Nitrile–Nitrile and Nitrile–Alkyne Coupling of FcCN and FcCCCN
Authors: Becker Lisanne , Strehler Frank , Korb Marcus , Arndt Perdita , Spannenberg Anke , Baumann Wolfgang , Lang Heinrich , Rosenthal Uwe 
Published: February 2014

AbstractThe reactions of the Group 4 metallocene alkyne complexes, [Cp*2M(η2‐Me3SiC2SiMe3)] (1 a: M=Ti, 1 b: M=Zr, Cp*=η5‐pentamethylcyclopentadienyl), with the ferrocenyl nitriles, FcCN and FcCCCN (Fc=Fe(η5‐C5H5)(η5‐C5H4)), is described. In case of FcCN an unusual nitrile–nitrile CC homocoupling was observed and 1‐metalla‐2,5‐diaza‐cyclopenta‐2,4‐dienes (3 a, b) were obtained. As the first step of the reaction with 1 b, the nitrile was coordinated to give [Cp*2Zr(η2‐Me3SiC2SiMe3)(NC‐Fc)] (2 b). The reactions with the 3‐ferrocenyl‐2‐propyne‐nitrile FcCCCN lead to an alkyne–nitrile CC coupling of two substrates and the formation of 1‐metalla‐2‐aza‐cyclopenta‐2,4‐dienes (4 a, b). For M=Zr, the compound is stabilized by dimerization as evidenced by single‐crystal X‐ray structure analysis. The electrochemical behavior of 3 a, b and 4 a, b was investigated, showing decomposition after oxidation, leading to different redox‐active products.
Alternating Current Electrohydrodynamics Induced Nanoshearing and Fluid Micromixing for Specific Capture of Cancer Cells
Authors: Vaidyanathan Ramanathan , Rauf Sakandar , Dray Eloïse , Shiddiky Muhammad J. A. , Trau Matt 
Published: February 2014

AbstractWe report a new tuneable alternating current (ac) electrohydrodynamics (ac‐EHD) force referred to as “nanoshearing” which involves fluid flow generated within a few nanometers of an electrode surface. This force can be externally tuned via manipulating the applied ac‐EHD field strength. The ability to manipulate ac‐EHD induced forces and concomitant fluid micromixing can enhance fluid transport within the capture domain of the channel (e.g., transport of analytes and hence increase target–sensor interactions). This also provides a new capability to preferentially select strongly bound analytes over nonspecifically bound cells and molecules. To demonstrate the utility and versatility of nanoshearing phenomenon to specifically capture cancer cells, we present proof‐of‐concept data in lysed blood using two microfluidic devices containing a long array of asymmetric planar electrode pairs. Under the optimal experimental conditions, we achieved high capture efficiency (e.g., approximately 90 %; % RSD=2, n=3) with a 10‐fold reduction in nonspecific adsorption of non‐target cells for the detection of whole cells expressing Human Epidermal Growth Factor Receptor 2 (HER2). We believe that our ac‐EHD devices and the use of tuneable nanoshearing phenomenon may find relevance in a wide variety of biological and medical applications.
A Clear‐Cut Example of Selective BpinBdan Activation and Precise Bdan Transfer on Boron Conjugate Addition
Authors: Cid Jessica , Carbó Jorge J. , Fernández Elena 
Published: February 2014

AbstractActivating the non‐symmetrical BpinBdan diboron reagent with alkoxide leads to the formation of two possible adducts: MeO−→BpinBdan or MeO−→BdanBpin. Experimental and theoretical investigation confirms that the MeO−→Bpin interaction is preferred and thus selective formation of a CBdan bond upon reaction with an activated CC bond.
Synthesis and Structural Data of Tetrabenzo[8]circulene
Authors: Miller Robert W. , Duncan Alexandra K. , Schneebeli Severin T. , Gray Danielle L. , Whalley Adam C. 
Published: February 2014

AbstractIn 1976, the first attempted synthesis of the saddle‐shaped molecule [8]circulene was reported. The next 37 years produced no advancement towards the construction of this complicated molecule. But remarkably, over the last six months, a flurry of progress has been made with two groups reporting independent and strikingly different strategies for the synthesis of [8]circulene derivatives. Herein, we present a third synthetic method, in which we target tetrabenzo[8]circulene. Our approach employs a Diels–Alder reaction and a palladium‐catalyzed arylation reaction as the key steps. Despite calculations describing the instability of [8]circulene, coupled with the reported instability of synthesized derivatives of the parent molecule, the addition of four fused benzenoid rings around the periphery of the molecule provides a highly stable structure. This increased stability over the parent [8]circulene was predicted by using Clar’s theory of aromatic sextets and is a result of the compound becoming fully benzenoid upon incorporation of these additional rings. The synthesized compound exhibits remarkable stability under ambient conditions—even at elevated temperatures—with no signs of decomposition over several months. The solid‐state structure of this compound is significantly twisted compared to the calculated structure primarily as a result of crystal‐packing forces in the solid state. Despite this contortion from the lowest‐energy structure, a range of structural data is presented confirming the presence of localized aromaticity in this large polycyclic aromatic hydrocarbon.
Hetero‐Epitaxial Approach by Using Labile Coordination Sites to Prepare Catenated Metal–Organic Frameworks with High Surface Areas
Authors: Zhu Nianyong , Lennox Matthew J. , Tobin Gerard , Goodman Lisa , Düren Tina , Schmitt Wolfgang 
Published: February 2014

AbstractA solid‐state approach that takes advantage of the ordered 3D arrangement of active secondary building units allows the preparation of new interlocked MOFs that grow hetero‐epitaxially on the crystal faces of a precursor phase that acts as a “topological blueprint”. The synthetic strategy is exemplified by using rigid acetylene‐based ligands to produce highly augmented CuII acetate‐based MOFs.
NIS‐Assisted Aza‐Friedel–Crafts Reaction with α‐Carbamoysulfides as Precursors of N‐Carbamoylimines
Authors: George Nicolas , Bekkaye Mathieu , Alix Aurélien , Zhu Jieping , Masson Géraldine 
Published: February 2014

AbstractA general and practical N‐iodosuccinimide (NIS)‐promoted aza‐Friedel–Crafts reaction of various aromatic nucleophiles with N‐acylimines generated in situ from α‐amidosulfides to give a rapid access to highly functionalized amines is described. The newly developed methodology is very mild, fast, efficient, and complementary.
Impact of Obstructive Sleep Apnea on Cardiovascular Outcomes in Patients Treated With Percutaneous Coronary Intervention: Rationale and Design of the Sleep and Stent Study
Authors: Loo Germaine , Koo Chieh‐Yang , Zhang Junjie , Li Ruogu , Sethi Rithi , Ong Thun‐How , Tai Bee‐Choo , Lee Chi‐Hang 
Published: February 2014

ABSTRACTElucidating the effects of obstructive sleep apnea (OSA) on cardiovascular outcomes is crucial in risk assessments and therapeutic recommendations for affected individuals. The Sleep and Stent Study is a multicenter observational study investigating the relationships between OSA and cardiovascular outcomes in patients treated with percutaneous coronary intervention (PCI). Eight centers in 5 countries (Singapore, China and Hong Kong, India, Myanmar, and Brazil) are participating in the study, and the recruitment target is 1600 patients. Adult patients age 18 to 80 years who have undergone successful PCI are eligible. Recruited patients will undergo an overnight sleep study using a level‐3 portable diagnostic device before hospital discharge. The sleep tracings will be analyzed by a certified sleep technologist and audited by a sleep physician, both of whom will be blinded to other study data. The patients will be divided into 2 groups based on apnea‐hypopnea index (AHI): OSA (AHI ≥15) and non‐OSA (AHI <15) groups. The primary study endpoint of cardiovascular death, myocardial infarction, stroke, and unplanned revascularization will be compared between the OSA and non‐OSA groups at a median follow‐up of 2 years. Secondary endpoints include all‐cause mortality, target‐vessel revascularization, stent thrombosis, and hospitalization for heart failure. As of December 31, 2013, a total of 1358 patients have been recruited. Based on the complete preliminary results of the first 785 recruited patients, the prevalence of OSA was 48.3%. We expect the follow‐up for primary endpoint to be completed in late 2015; study results will be presented in 2016.
Reliable Exclusion of Acute Coronary Syndrome Among Hospitalized Patients With Elevated Troponin
Authors: Davis Melinda B. , Shafton Asher , Desai Aken , Childers David , Bach David S. 
Published: February 2014

ABSTRACTBackgroundElevated cardiac troponin I (cTnI) occurs in acute coronary syndrome (ACS) as well as various scenarios not associated with ACS.HypothesisSimple clinical criteria can reliably exclude ACS among hospitalized patients with elevated cTnI.MethodsRecords for patients hospitalized from January to April 2011 with elevated cTnI (>0.29 ng/dL) and an available echocardiogram were retrospectively reviewed. Patients with ST‐segment elevation myocardial infarction were excluded. Based on available clinical data, patients were classified as having ACS or elevation of cTnI unrelated to ACS (non‐ACS). Median follow‐up was 365 days.ResultsOf 265 records meeting inclusion criteria, 82 (31%) had ACS and 183 (69%) had non‐ACS. In multivariable analysis, odds ratios for non‐ACS were 7.6 (95% confidence interval [CI]: 3.8‐15.3) for peak cTnI <2 ng/dL, 6.3 (95% CI: 3.1‐13.0) for absent wall‐motion abnormality, and 4.4 (95% CI: 2.2‐8.6) for no prior coronary artery disease history. The area under the receiver operating curve for a model using these 3 variables was 0.86, with a 98% negative predictive value for excluding ACS. Patients who met these 3 criteria had no ACS‐related deaths over 1‐year follow‐up.ConclusionsHospitalized patients with peak Tn level <2 ng/dL, no prior history of coronary artery disease, and no new echocardiographic wall‐motion abnormality appear to have a very low likelihood of ACS. Prospective validation of these results is needed to determine whether additional diagnostic testing could be safely avoided in hospitalized patients meeting these simple clinical criteria.
Towards Matched Pairs of Porphyrin–ReI/99mTcI Conjugates that Combine Photodynamic Activity with Fluorescence and Radio Imaging
Authors: Gianferrara Teresa , Spagnul Cinzia , Alberto Roger , Gasser Gilles , Ferrari Stefano , Pierroz Vanessa , Bergamo Alberta , Alessio Enzo 
Published: February 2014

AbstractWe recently prepared two novel water soluble porphyrins bearing a single peripheral chelator, either diethylenetriamine (1) or bipyridyl (2), tethered to one meso position. The preparation of their conjugates with a fac‐{99mTc(CO)3}+ fragment and the potential of these resulting conjugates as fluorescence and radio imaging tools were also described. In this work, we focused on the corresponding non‐radioactive analogues that bear the fac‐{Re(CO)3}+ fragment (diethylenetriamine 3 and bipyridyl 4). We report on the uptake, in vitro PDT activity, and cellular localization of ReI conjugates 3 and 4 in comparison to the parent porphyrins 1 and 2. Compounds 1–4 have modest or negligible cytotoxicity in the dark against HeLa human cervical cancer cells but become remarkably cytotoxic after exposure to moderate doses of red visible light (590–700 nm). This phototoxicity was found to be directly proportional to the total light dose. Although the four compounds show distinct uptake patterns, they have comparable PDT activity. Confocal fluorescence measurements showed that porphyrin 1 and its ReI conjugate 3 have different cellular localization patterns in HeLa cells.
Effects of the Tumor‐Vasculature‐Disrupting Agent Verubulin and Two Heteroaryl Analogues on Cancer Cells, Endothelial Cells, and Blood Vessels
Authors: Mahal Katharina , Resch Marcus , Ficner Ralf , Schobert Rainer , Biersack Bernhard , Mueller Thomas 
Published: February 2014

AbstractTwo analogues of the discontinued tumor vascular‐disrupting agent verubulin (Azixa®, MPC‐6827, 1) featuring benzo‐1,4‐dioxan‐6‐yl (compound 5 a) and N‐methylindol‐5‐yl (compound 10) residues instead of the para‐anisyl group on the 4‐(methylamino)‐2‐methylquinazoline pharmacophore, were prepared and found to exceed the antitumor efficacy of the lead compound. They were antiproliferative with single‐digit nanomolar IC50 values against a panel of nine tumor cell lines, while not affecting nonmalignant fibroblasts. Indole 10 surpassed verubulin in seven tumor cell lines including colon, breast, ovarian, and germ cell cancer cell lines. In line with docking studies indicating that compound 10 may bind the colchicine binding site of tubulin more tightly (Ebind=−9.8 kcal mol−1) than verubulin (Ebind=−8.3 kcal mol−1), 10 suppressed the formation of vessel‐like tubes in endothelial cells and destroyed the blood vessels in the chorioallantoic membrane of fertilized chicken eggs at nanomolar concentrations. When applied to nude mice bearing a highly vascularized 1411HP germ cell xenograft tumor, compound 10 displayed pronounced vascular‐disrupting effects that led to hemorrhages and extensive central necrosis in the tumor.
GluN2B‐Selective N‐Methyl‐d‐aspartate (NMDA) Receptor Antagonists Derived from 3‐Benzazepines: Synthesis and Pharmacological Evaluation of Benzo[7]annulen‐7‐amines
Authors: Benner Andre , Bonifazi Alessandro , Shirataki Chikako , Temme Louisa , Schepmann Dirk , Quaglia Wilma , Shoji Osami , Watanabe Yoshihito , Daniliuc Constantin , Wünsch Bernhard 
Published: February 2014

AbstractGiven their high neuroprotective potential, ligands that block GluN2B‐containing N‐methyl‐D‐aspartate (NMDA) receptors by interacting with the ifenprodil binding site located on the GluN2B subunit are of great interest for the treatment of various neuronal disorders. In this study, a novel class of GluN2B‐selective NMDA receptor antagonists with the benzo[7]annulene scaffold was prepared and pharmacologically evaluated. The key intermediate, N‐(2‐methoxy‐5‐oxo‐6,7,8,9‐tetrahydro‐5H‐benzo[7]annulen‐7‐yl)acetamide (11), was obtained by cyclization of 3‐acetamido‐5‐(3‐methoxyphenyl)pentanoic acid (10 b). The final reaction steps comprise hydrolysis of the amide, reduction of the ketone, and reductive alkylation, leading to cis‐ and trans‐configured 7‐(ω‐phenylalkylamino)benzo[7]annulen‐5‐ols. High GluN2B affinity was observed with cis‐configured γ‐amino alcohols substituted with a 3‐phenylpropyl moiety at the amino group. Removal of the benzylic hydroxy moiety led to the most potent GluN2B antagonists of this series: 2‐methoxy‐N‐(3‐phenylpropyl)‐6,7,8,9‐tetrahydro‐5H‐benzo[7]annulen‐7‐amine (20 a, Ki=10 nM) and 2‐methoxy‐N‐methyl‐N‐(3‐phenylpropyl)‐6,7,8,9‐tetrahydro‐5H‐benzo[7]annulen‐7‐amine (23 a, Ki=7.9 nM). The selectivity over related receptors (phencyclidine binding site of the NMDA receptor, σ1 and σ2 receptors) was recorded. In a functional assay measuring the cytoprotective activity of the benzo[7]annulenamines, all tested compounds showed potent NMDA receptor antagonistic activity. Cytotoxicity induced via GluN2A subunit‐containing NMDA receptors was not inhibited by the new ligands.
CMOS based Q‐switch for low‐power pulsed14N quadruple resonance
Authors: Aissani Sarra , Guendouz Laouès , Canet Daniel 
Published: February 2014

ABSTRACTIn order to reduce the recovery time of the nuclear quadrupole resonance probe (which implies the insertion of a dead time between the end of the pulse and the beginning of signal acquisition), several strategies have been proposed in the case of high‐power radio frequency (rf) pulses. In fact, these strategies rely on a common principle, which is to lower, for an appropriate duration, the probe quality factor immediately after the transmit pulse. The quality factor is then restored for the receive period. In the case of a low‐power rf pulses, we propose a very simple circuit that can alleviate the ringing following the rf pulse just by controlling a rf complementary metal–oxide–semiconductor (CMOS) switch inside the probe circuit. Such a technology features a low insertion loss and a low consumption, the switch being driven by a single‐pin low voltage CMOS or transistor‐transistor logic (TTL) control input. These properties are quite suitable for portable applications. Moreover, we have found that, for simple one‐pulse experiments, this technology provides undistorted 14N quadrupole resonance spectra along with a significant improvement of the signal‐to‐noise ratio in the case of relatively broad lines involving a fine structure. © 2014 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 44B: 12–17, 2014
Analytical expressions for magnetic fields and field gradients of current‐carrying triangles
Authors: Forthmann Peter , Amthor Thomas 
Published: February 2014

ABSTRACTWe present an analytical method for calculating magnetic field gradients generated by arbitrary triangulated surfaces. Our work builds upon the results published by Pissanetzky and Xiang, who presented formulas for calculating the magnetic field of current‐carrying faceted surfaces. We show that the analytical gradient expressions can be computed considerably faster than finite field value differences. We also find that the aforementioned published expressions for the magnetic field can be simplified and optimized substantially. Closer inspection of the algorithms, for both field and gradient, reveals a number pathological parameter constellations, which require special treatment. We present a detailed discussion on this. Our results can be directly applied in the optimization of complex magnetic field coils, such as magnetic resonance gradient coils. © 2014 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 44B: 18–25, 2014
Prognostic significance of cytoskeleton‐associated membrane protein 4 and its palmitoyl acyltransferase DHHC2 in hepatocellular carcinoma
Authors: Li Shuang‐Xi , Tang Gu‐Sheng , Zhou Dong‐Xun , Pan Yu‐Fei , Tan Ye‐Xiong , Zhang Jian , Zhang Bo , Ding Zhi‐Wen , Liu Li‐Juan , Jiang Tian‐Yi , Hu He‐Ping , Dong Li‐Wei , Wang Hong‐Yang 
Published: February 2014

BACKGROUNDThe functions of cytoskeleton‐associated membrane protein 4 (CKAP4), one kind of type II transmembrane protein, are associated with the palmitoyl acyltransferase DHHC2. The objective of the current study was to investigate CKAP4/DHHC2 expression and its prognostic significance in patients with hepatocellular carcinoma (HCC).METHODSTwo independent cohorts of 416 patients with HCC were enrolled. All the patients included had defined clinicopathologic and follow‐up data. Using real‐time polymerase chain reaction and immunohistochemical assay, CKAP4 and DHHC2 expression were evaluated. The association between CKAP4/DHHC2 expression and HCC‐specific disease‐free survival and overall survival was analyzed by Kaplan‐Meier curves, the log‐rank test, and Multivariate Cox regression analyses.RESULTSThe data documented that CKAP4 expression was much higher in HCC tumor tissues compared with adjacent normal tissues and its expression was significantly correlated with tumor size, intrahepatic metastases, portal venous invasion, and Barcelona Clinic Liver Cancer stage of disease in 2 cohorts of patients. On survival analysis, patients with high CKAP4 expression appeared to have a favorable overall survival and a longer disease‐free survival compared with those with low expression. DHHC2 expression was also examined in tissue microarray analysis by immunohistochemistry and the results demonstrated that 87.6% of the cases had low expression of DHHC2. Kaplan‐Meier analysis indicated that a high level of DHHC2 expression predicted favorable overall survival and disease‐free survival rates in both the training cohort and validation set. Furthermore, the combination of CKAP4 and DHHC2 was found to have a more powerful efficiency in prognosis prediction than either one alone.CONCLUSIONSTo the best of our knowledge, the current study is the first to demonstrate that the expression of CKAP4 and its palmitoyl acyltransferase DHHC2 correlates with disease progression and metastasis in patients with HCC and may provide prognostic and therapeutic value. Cancer 2014;120:1520–1531. © 2014 American Cancer Society.
Reprocessing unsatisfactory ThinPrep Papanicolaou tests using a modified SurePath preparation technique
Authors: Randolph Melissa L. , Wu Howard H. , Crabtree William N. 
Published: February 2014

BACKGROUNDThe frequency of unsatisfactory gynecologic specimens has increased in the study laboratory over the last few years due to the advent of personal lubricants. Similarly, lysed blood, protein, and necrotic debris present a challenge in terms of negative cell transference caused by a clogged filter. In the current study, the authors evaluated the potential use of a modified SurePath reprocessing technique to decrease the frequency of unsatisfactory specimens.METHODSAn aliquot for human papillomavirus testing was set aside and the remaining specimen in the ThinPrep vial was submitted for sedimentation. A methanol wash was performed using preservative that was added to the remaining sediment. The specimen was vortexed and a protein wash of Tris‐buffered deionized water was added before processing. The specimens were stained using the ThinPrep staining protocol. Both the original specimen and the reprocessed specimens were manually reviewed by 1 cytotechnologist and 2 pathologists to determine specimen adequacy.RESULTSA total of 1937 ThinPrep Papanicolaou tests were reprocessed and examined. Of these, 1093 (56%) specimens were satisfactory, 624 of which (57%) demonstrated evidence of a transformation zone component. Epithelial cell abnormalities were identified in 116 specimens (10.6%), including 11 high‐grade squamous intraepithelial lesion specimens (1.0%); 5 specimens with a classification of atypical squamous cells, cannot rule out a high‐grade lesion (0.5%); 21 low‐grade squamous intraepithelial lesion specimens (1.9%); and 79 specimens classified as atypical squamous cells of undetermined significance (7.2%).CONCLUSIONSThe modified SurePath processing technique was adept at handling nearly all of the challenges that biological and environmental conditions (blood, protein, lubricant, etc) present in liquid‐based filter preparations. A total of 1093 (56%) of 1937 unsatisfactory ThinPrep Papanicolaou tests were converted to a satisfactory state, resulting in 116 abnormalities (10.6%) being diagnosed that otherwise would have gone undetected. Cancer (Cancer Cytopathol) 2014;122:343–348. © 2014 American Cancer Society.