bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generating and Dimerizing the Transient 16‐Electron Phosphinidene Complex [Cp*IrPAr]: A Theoretical and Experimental Study
Authors: Termaten Arjan T. , Nijbacker Tom , Ehlers Andreas W. , Schakel Marius , Lutz Martin , Spek Anthony L. , McKee Michael L. , Lammertsma Koop 
Published: July 2004

AbstractThe properties of the 16‐electron phosphinidene complex [CpRIrPR] were investigated experimentally and theoretically. Density functional theory calculations show a preferred bent geometry for the model complex [CpIrPH], in contrast to the linear structure of [CpIrNH]. Dimerization to give [{CpIrPH}2] and ligand addition to afford [Cp(L)IrPH] (L=PH3, CO) were calculated to give compounds that were energetically highly favorable, but which differed from the related imido complexes. Transient 16‐electron phosphinidene complex [Cp*IrPAr] could not be detected experimentally. Dehydrohalogenation of [Cp*IrCl2(PH2Ar)] in CH2Cl2 at low temperatures resulted in the novel fused‐ring systems 17 (Ar=Mes*) and 20 (Ar=Mes), with dimeric [{Cp*IrPAr}2] being the likely intermediate. Intramolecular CH bond activation induced by steric factors is considered to be the driving force for the irreversible formation of 17 and 20. ONIOM calculations suggest this arises because of the large steric congestion in [{Cp*IrPAr}2], which forces it toward a more reactive planar structure that is apt to rearrange.
Synthesis and Characterization of Pentachlorophenyl–Metal Derivatives with d0 and d10 Electron Configurations
Authors: Ara Irene , Forniés Juan , García‐Monforte M. Angeles , Martín Antonio , Menjón Babil 
Published: July 2004

AbstractBy reaction of [TiCl3(thf)3] with LiC6Cl5, the homoleptic organotitanium(III) derivative [Li(thf)4][TiIII(C6Cl5)4] (1) has been prepared as a paramagnetic (d1, S = 1/2, gav = 1.959(2)), extremely air‐sensitive compound. Oxidation of 1 with [N(C6H4Br‐4)3][SbCl6] gives the diamagnetic (d0) organotitanium(IV) species [TiIV(C6Cl5)4] (2). Compounds 1 and 2 are also electrochemically related (E1/2 = 0.05 V). The homoleptic, diamagnetic (d10) compounds [N(PPh3)2][Tl(C6Cl5)4] (3) and [Sn(C6Cl5)4] (4) have also been prepared. Nearly tetrahedral environments have been found for the d0, d10, and d1 metal centers in the molecular structures of compounds 2–4 as well as in that of [Li(thf)2(OEt2)2][TiIII(C6Cl5)4]⋅CH2Cl2 (1′) (X‐ray diffraction). The reaction of the heavier Group 4 metal halides, MCl4 (M = Zr, Hf) with LiC6Cl5 in the presence of [NBu4]Br gives, in turn, the heteroleptic species [NBu4][M(C6Cl5)3Cl2] (M = Zr (5), Hf (6)). Compounds 5 and 6 are isomorphous and isostructural, with the metal center in a trigonal‐bipyramidal (TBPY‐5) environment defined by two axial Cl ligands and three equatorial C6Cl5 groups (X‐ray diffraction). No redox features are observed for compounds 3–6 in CH2Cl2 solution between −1.6 and +1.6 V.
Biomimetic Synthesis of the Tumor‐Associated (2,3)‐Sialyl‐T Antigen and Its Incorporation into Glycopeptide Antigens from the Mucins MUC1 and MUC4
Authors: Dziadek Sebastian , Brocke Constanze , Kunz Horst 
Published: July 2004

AbstractGlycoproteins on epithelial tumor cells often exhibit aberrant glycosylation profiles. The incomplete formation of the glycan side chains resulting from a down‐regulated glucosamine transfer and a premature sialylation results in additional peptide epitopes, which become accessible to the immune system in mucin‐type glycoproteins. These cancer‐specific structure alterations are considered to be a promising basis for selective immunological attack on tumor cells. Among the tumor‐associated saccharide antigens, the (2,3)‐sialyl‐T antigen has been identified as the most abundant glycan, found in several different carcinoma cell lines. According to a linear biomimetic strategy, the (2,3)‐sialyl‐T antigen was synthesized by a stepwise glycan chain extension of a protected galactosamine‐threonine precursor. For the construction of immunostimulating antigens combining both peptide and saccharide motifs, this antigen was incorporated into glycopeptide partial structures from the mucins MUC1 and MUC4 by sequential solid‐phase synthesis.
Olefins as Steering Ligands for Homogeneously Catalyzed Hydrogenations
Authors: Maire Pascal , Deblon Stephan , Breher Frank , Geier Jens , Böhler Carsten , Rüegger Heinz , Schönberg Hartmut , Grützmacher Hansjörg 
Published: July 2004

AbstractIridium(I) complexes containing a (5H‐dibenzo[a,d]cyclohepten‐5‐yl)‐phosphane (troppR; R = phosphorus‐bound substituent = Ph, Cyc) as a rigid, concave‐shaped, mixed phosphane olefin ligand were prepared and tested as catalyst precursors in the hydrogenation of imines. With the complex [Ir(troppCyc)(cod)]OTf, turnover frequencies (TOFs) of >6000 h−1 were reached in the hydrogenation of N‐phenyl‐benzylidenamine, PhNCHPh. Lower activities (TOF>80 h−1) are observed with N‐phenyl‐(1‐phenylethylidene)amine, PhNCMePh. Chiral tropp‐type ligands were prepared in few simple steps. Monosubstitution of the olefinic unit in the dibenzo[a,d]cycloheptenyl moiety with (R)‐ or (S)‐mentholate gave mixtures of diastereomers that could be separated and isolated in enantiomerically pure form. Iridium(I) complexes with these ligands are rare examples of side‐on bonded enolether complexes. In catalytic imine hydrogenations, complete conversion (>98 %) was reached in all cases (conditions: p[H2] = 50 bar, T = 50 °C, t = 2 h, substrate/catalyst 100:1). The best enantiomeric excess (ee = 86 % S isomer) was reached with PhNCMePh as substrate and the R,R form of the (10‐menthyloxy‐5H‐dibenzo[a,d]cyclohepten‐5‐yl)diphenylphosphane ligand. The iridium(I) complex containing the same phosphane gave a 60 % ee (S isomer) with the enamide N‐(1‐phenylvinyl)acetamide as substrate (conditions: p[H2] = 4 bar, T = 50 °C, t = 18 h, substrate/catalyst = 50:1). These reactions constitute the first examples in which chiral olefins have been used as steering ligands in catalytic enantioselective hydrogenations.
Binary Regiocontrol in the Reaction Between Pentadienyltin and Imines by Lewis Acids and N‐Substituents.
Authors: Nishigaichi Yutaka , Ishihara Masahiko , Fushitani Shigeo , Uenaga Kenji , Takuwa Akio 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Powerful, Practical and Chemoselective Synthesis of 2‐Anilinoalkanols Catalyzed by Bi(TFA)3 or Bi(OTf)3 in the Presence of Molten TBAB.
Authors: Khodaei Mohammd M. , Khosropour Ahmad R. , Ghozati Kazem 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Stereodivergent Synthesis of Chiral 2‐Alkenylaziridines: Palladium(0)‐Catalyzed 2,3‐cis‐Selective Aziridination and Base‐Mediated 2,3‐trans‐Selective Aziridination.
Authors: Ohno Hiroaki , Takemoto Yoshiji , Fujii Nobutaka , Tanaka Tetsuaki , Ibuka Toshiro 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Rapid Catalytic Asymmetric Synthesis of 1,3,4‐Trisubstituted Pyrrolidines.
Authors: Belyk Kevin M. , Beguin Charlotte D. , Palucki Michael , Grinberg Nelu , DaSilva Jimmy , Askin David , Yasuda Nobuyoshi 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Studies on Non‐Thiazolidinedione Antidiabetic Agents. Part 3. Preparation and Biological Activity of the Metabolites of TAK‐559.
Authors: Imoto Hiroshi , Matsumoto Mitsuharu , Odaka Hiroyuki , Sakamoto Junichi , Kimura Hiroyuki , Nonaka Masami , Kiyota Yutaka , Momose Yu 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Evaluation of 9‐Anilinothiazolo[5,4‐b]quinoline Derivatives as Potential Antitumorals.
Authors: Rodriguez‐Loaiza Pilar , Quintero Angelina , Rodriguez‐Sotres Rogelio , Solano Jose D. , Lira‐Rocha Alfonso 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Novel 2‐Nitroimidazole‐Tethered Tricyclic Quinolines, Bearing a Second Heteroatom, and Their in vitro Evaluation as Hypoxia‐Selective Cytotoxins and Radiosensitizers.
Authors: Papadopoulou Maria V. , Rosenzweig Howard S. , Bloomer William D. 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 2,3,8‐Trisubstituted 7H‐Isoindolo[5,6‐g]quinoxaline‐5,7,9,11(8H)‐tetraones.
Authors: Lee Heesoon , Cho Sungmoon , Choi Byeonggil , Namgoong Kwon , Jung Jae‐Kyung 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 2‐N,N‐Dimethylaminomethyl‐2,3,3a,12b‐tetrahydrodibenzo[b,f]furo [2,3‐d]oxepin Derivatives as Potential Anxiolytic Agents.
Authors: Trabanco Andres Avelino , Alonso Jose Manuel , Andres Jose Ignacio , Cid Jose Maria , Fernandez Javier , Iturrino Laura , Megens Anton 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Studies on Organophosphorus Compounds: Reactions of Benzosuberones with 2,4‐Bis(p‐methoxyphenyl)‐1,3,2,4‐dithiadiphosphetane‐2,4‐disulfide (Lawesson′s reagent).
Authors: Venkateswarlu Peesapati , Venkata Srikanth Chitty 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
X‐Ray, 1H/13C 2D and 3D NMR Studies of the Structures of Davallene (I) and Adipedatol (II), Two Triterpenes Isolated from American Adiantum capillus‐veneris.
Authors: Jankowski C. K. , Aumelas A. , Thuery P. , Reyes‐Chilpa R. , Jimenez‐Estrada M. , Barrios H. , Diaz E. 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient Synthesis of (.+‐.)‐γ‐Lycorane Employing Stereoselective Conjugate Addition to Nitroolefin.
Authors: Yasuhara Tomohisa , Osafune Emi , Nishimura Katsumi , Yamashita Mitsuaki , Yamada Ken‐ichi , Muraoka Osamu , Tomioka Kiyoshi 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Chemistry of Renieramycins. Part 4. Synthesis of a Simple Natural Marine Product, 6‐Hydroxy‐7‐methoxyisoquinolinemethanol.
Authors: Saito Naoki , Tanaka Chieko , Satomi Tomoo , Oyama Chigusa , Kubo Akinori 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Evaluation of New Arylsulfonamidomethylcyclohexyl Derivatives as Human Neuropeptide Y Y5 Receptor Antagonists for the Treatment of Obesity.
Authors: Moreno Antonio , Perez Silvia , Galiano Silvia , Juanenea Laura , Erviti Oihana , Frigola Carmen , Aldana Ignacio , Monge Antonio 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Structure—Activity Relationships of a Novel Class of Endothelin Receptor Selective Antagonists; 6‐Carboxy‐2‐isopropylamino‐5,7‐diarylcyclopenteno[1,2‐b]pyridines.
Authors: Ohtake Norikazu , et al. et al. 
Published: July 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Clinicopathologic characteristics of 143 patients with synchronous bilateral invasive breast carcinomas treated in a single institution
Authors: Intra Mattia , Rotmensz Nicole , Viale Giuseppe , Mariani Luigi , Bonanni Bernardo , Mastropasqua Mauro G. , Galimberti Viviana , Gennari Roberto , Veronesi Paolo , Colleoni Marco , Tousimis Eleni , Galli Arianna , Goldhirsch Aron , Veronesi Umberto 
Published: July 2004

AbstractBACKGROUNDSynchronous bilateral invasive breast carcinoma (SBIBC) ranged in incidence from 0.3% to as high as 12%.METHODSBetween April 1997 and February 2003, 143 consecutive patients with SBIBC were treated at the European Institute of Oncology (Milan, Italy). Their information was collected prospectively in a database. The bilateral tumors were divded into left and right tumors. Tumor size, histology, grade, lymph node status, estrogen (ER) and progesterone receptor (PgR) status, HER‐2 expression, peritumoral vascular invasion (PVI), Ki‐67 expression, extensive in situ component (EIC), and multifocality between the two groups were analyzed. During the same time period, 6218 patients with unilateral invasive breast carcinoma (UIBC) were analyzed in the same manner for comparison with the patients with SBIBC.RESULTSThere were no significant differences between left and right tumors, and the observed histopathologic agreement within the same patient was significantly superior than statistically expected for all characteristics except size, lymph node status, and multifocality. When compared with patients with UIBC, patients with SBIBC were more likely to present with smaller tumors and showed a higher frequency of invasive lobular carcinoma, lower histologic grade, higher rate of ER and PgR positivity, and lower PVI and Ki‐67 expression.CONCLUSIONSThe high concordance of histopathologic characteristics between SBIBC within the same patient could reflect a particular hormonal environment that influenced either the initiation and development of these lesions simultaneously and independently from the single or multi‐clonal origin, either a less aggressive biological behavior compared with UIBC. In particular, the strong agreement of the observed EIC in SBIBC within the same patient seemed to definitively exclude the metastatic origin of these tumors. Cancer 2004. © 2004 American Cancer Society.
Small cell carcinoma of the urinary bladder
Authors: Cheng Liang , Pan Chong‐Xian , Yang Ximing J. , Lopez‐Beltran Antonio , MacLennan Gregory T. , Lin Haiqun , Kuzel Timothy M. , Papavero Veronica , Tretiakova Maria , Nigro Kelly , Koch Michael O. , Eble John N. 
Published: July 2004

AbstractBACKGROUNDSmall cell carcinoma of the urinary bladder is an uncommon tumor that has been described in case reports or small series. Herein, the authors report a series of 64 patients with small cell carcinoma of the urinary bladder.METHODSHistologic slides and medical records from 64 patients with small cell carcinoma of the urinary bladder were reviewed for morphologic, demographic, and clinical data. All patients fulfilled the criteria established for small cell carcinoma according to the World Health Organization classification system. The 2002 tumor, lymph node, and metastasis (TNM) system was used for pathologic staging. The correlations of various clinicopathologic characteristics with survival were analyzed.RESULTSPatients ranged in age from 36 years to 85 years (mean age, 66 years). The male‐to‐female ratio was 3.3:1.0. Among patients with clinical information available, 65% had a history of cigarette smoking, and 88% presented with hematuria. All but one patient had muscle‐invasive disease at presentation. Thirty‐eight patients (59%) underwent cystectomy. Sixty‐six percent of patients had lymph node metastasis at the time of cystectomy. Twenty patients (32%) had pure small cell carcinoma, and 44 patients (68%) had small cell carcinoma with other histologic types (35 patients had urothelial carcinoma, 4 patients had adenocarcinoma, 2 patients had sarcomatoid urothelial carcinoma, and 3 patients had both adenocarcinoma and urothelial carcinoma). With a mean follow‐up of 21 months, 68% of patients died of bladder carcinoma. None of the clinicopathologic parameters studied (age, gender, presenting symptoms, smoking history, the presence of a nonsmall cell carcinoma component, chemotherapy, or radiation therapy) were associated with survival. No significant survival difference was found between patients who did and did not undergo cystectomy (P = 0.65). Patients who had organ‐confined disease had marginally better survival compared with patients who had nonorgan‐confined disease (P = 0.06). The overall, 1‐year, 18‐month, 3‐year, and 5‐year disease‐specific survival rates were 56%, 41%, 23%, and 16%, respectively.CONCLUSIONSThe prognosis for patients with small cell carcinoma of the urinary bladder remains poor, even though the overall survival for patients with bladder carcinoma has improved significantly over the last decade. Cancer 2004. © 2004 American Cancer Society.
On the synthesis and characterization of La doped MgB2 superconductor
Authors: Shekhar C. , Giri R. , Tiwari R. S. , Srivastava O. N. 
Published: July 2004

AbstractWe report the synthesis of La doped MgB2 superconductors with nominal compositions Mg1‐xLaxB2 (with x = 0.01, 0.03, 0.05, 0.07) by solid state reaction at ambient pressure. A special encapsulation technique has been used by us to prepare high quality superconducting MgB2 samples. The bulk polycrystalline samples possess superconducting transition temperature Tc(R=0) ranging between 36‐39 K. It has been found that transport critical current density Jc of the samples change significantly with the doping level of La. A high transport (Jc) value ∼1.9 x 103 A/cm2 at 15 K has been achieved for Mg0.97La0.03B2 sample. The XRD and TEM investigations indicate that the samples prepared by encapsulation method are devoid of MgO, which is generally found when synthesis of MgB2 is done through sintering of Mg and B powders. The detailed microstructural investigations of Mg0.97La0.03B2 specimens by transmission electron microscopy (TEM) reveal the presence of partial dislocation network, moiré fringes and superlattice structure in the as synthesized samples. The higher transport critical current density observed in Mg0.97La0.03B2 superconductor has been attributed to the partial dislocations which are capable of providing pinning centres. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the dimensions of species participating in the growth of ammonium oxalate monohydrate crystals from viscosity data of concentrated aqueous solutions
Authors: Sangwal K. , Frej H. , Misztal R. 
Published: July 2004

AbstractThe experimental data of the temperature and concentration dependence of viscosity of concentrated aqueous ammonium oxalate solutions are analysed using the hole theory of liquids and Einstein's model of viscosity. Analysis of the data revealed that the dimensions of the species participating in the growth of ammonium oxalate monohydrate crystals are 3‐5 times larger than the dimensions of individual NH4+ and C2O42‐ ions composing them. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive joint beamforming and B‐MMSE detection for CDMA signal reception under multipath interference
Authors: Chen Hsiao‐Hwa , Lee Jen‐Siu 
Published: July 2004

AbstractThe combination of antenna array beamforming with multiuser detection can effectively improve the detection efficiency of a wireless system under multipath interference, especially in a fast‐fading channel. This paper studies the performance of an adaptive beamformer incorporated with a block‐wise minimum mean square error(B‐MMSE) detector, which works on a unique signal frame characterized by training sequence preamble and data blocks segmented by zero‐bits. Both beam‐former weights updating and B‐MMSE detection are carried out by either least mean square (LMS) or recursive least square (RLS) algorithm. The comparison of the two adaptive algorithms applied to both beamformer and B‐MMSE detector will be made in terms of convergence behaviour and estimation mean square error. Various multipath patterns are considered to test the receiver's responding rapidity to changing multipath interference. The performance of the adaptive B‐MMSE detector is also compared with that of non‐adaptive version (i.e. through direct matrix inversion). The final performance in error probability simulation reveals that the RLS/B‐MMSE scheme outperforms non‐adaptive B‐MMSE by 1–5 dB, depending on the multipath channel delay profiles of concern. The obtained results also suggest that adaptive beamformer should use RLS algorithm for its fast and robust convergence property; while the B‐MMSE filter can choose either LMS or RLS algorithm depending on antenna array size, multipath severity and implementation complexity. Copyright © 2004 John Wiley & Sons, Ltd.
Hybrid prioritized multiple access protocols for bank LANs
Authors: Sklira M. , Pomportsis A. S. 
Published: July 2004

AbstractBank communication networks support four classes of traffic: Alarm, BSC, SNA and IP traffic, with each class of traffic having different priority requirements. In this paper, a framework for the design of multiple access protocols which are capable of handling the above priority classes is introduced. Furthermore, a hybrid multiple access protocol that has been designed according to the proposed framework is presented and evaluated by means of extensive simulation results. The proposed protocol, is applicable to a broad range of prioritized LANs. Copyright © 2004 John Wiley & Sons, Ltd.
TFRC friendliness and the case of ECN
Authors: Bakthavachalu Sivakumar , Labrador Miguel A. 
Published: July 2004

AbstractThe TFRC protocol has been proposed as a TCP‐friendly protocol to transport streaming media over the Internet. However, its deployment is still questionable because it has not been compared to other important protocols, analysed in the presence of important mechanisms, such as the explicit congestion notification (ECN), and studied under more realistic network conditions. In this paper, we address these three aspects, including other congestion control protocols not considered before in the same investigation, such as TCP Tahoe, Reno, Newreno, Vegas, Sack, GAIMD, and the Binomial algorithms, the effect of using ECN in the friendliness of the protocols, and the fairness of the protocols under static and dynamic network conditions. We found that TFRC can be safely deployed in the Internet if competing with TCP Tahoe, New Reno and SACK since fairness is achieved under all scenarios considered. We also found that ECN actually helps in achieving better fairness. However, fairness problems arise when TFRC competes with TCP Reno, GAIMD, SQRT or IIAD in static or dynamic conditions, or both. We used normalized throughput, fairness index, and convergence time as the main performance metrics for comparison. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and Biological Evaluation of Phorbol‐Resiniferatoxin (RTX) Hybrids
Authors: Appendino Giovanni , Bertolino Andrea , Minassi Alberto , Annunziata Rita , Szallasi Arpad , de Petrocellis Luciano , Di Marzo Vincenzo 
Published: July 2004

AbstractPhorboid 20‐homovanillates modified on ring C to mimic the constitution and conformation of the ultrapotent vanilloid resiniferatoxin (RTX) and on the AB ring system to suppress the tumour‐promoting potential of the terpenoid core were prepared. Several unexpected reactions were discovered, and the structure‐activity relationships for this class of vanilloid ligands were expanded. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Measuring horizontal inequity in Belgian health care using a Gaussian random effects two part count data model
Authors: Van Ourti Tom 
Published: July 2004

AbstractWe estimate the determinants of utilisation of physician and hospital services in Belgium using a one‐ and two‐part panel count data model, and a one‐ and two‐part pooled count data model. We conclude that the two‐part panel count data model is most appropriate as it controls for unobserved heterogeneity and allows for a two‐part decision‐making process. The estimates of the determinants of utilisation of health care are then used to calculate indices of horizontal inequity. We find that inequity for general practitioner and hospital services is stable across time and in favour of low‐income individuals, in the sense that, overall, they consume more than one would expect on the basis of their need, albeit the indices for hospital care are not significant. Horizontal equity applies to specialist care in all years, but from 1999 onwards, some evidence (although not statistically significant) of pro‐rich inequity is found. Copyright © 2004 John Wiley & Sons, Ltd.