bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymethinfarbstoffe, III. Mitteil.) Über vinylen‐homologe Aldehyde der Pyrrolreihe
Authors: Strell Martin , Kreis Fritz 
Published: May 2007

AbstractEs wird eine Methode zur Darstellung der ersten Glieder von vinylenhomologen Pyrrolaldehyden beschrieben. Diese Verbindungen wurden u.a. charakterisiert durch ihre 2.4‐Dinitro‐phenylhydrazone. Außerdem konnten mit Hilfe dieser Aldehyde neue unsymmetrische Polymethinfarbstoffe dargestellt werden.
Einfluß von Substituenten auf die Farbreaktion von N‐Acetyl‐glucosamin mit p‐Dimethylamino‐benzaldehyd
Authors: Kuhn Richard , Gauhe Adeline , Baer Hans Helmut 
Published: May 2007

AbstractIn 4‐Stellung substituierte N‐Acetyl‐glucosamine geben die Morgan‐Elson‐Reaktion nicht.
Untersuchungen an Steroiden XLI: Darstellung der 1‐Methyl‐3.12‐dioxy ar, AB‐cholansäure aus Desoxycholsäure
Authors: Inhoffen Hans Herloff , Jahnke Heinz , Nehring Peter 
Published: May 2007

AbstractDie Überführung der Desoxycholsäure in die 1‐Methyl‐3.12‐dioxy‐ar, AB‐cholansäure wird beschrieben.
Herstellung und Reaktionen von 16‐Oxy‐pregnan‐Derivaten
Authors: Heusler Karl , Wettstein Albert 
Published: May 2007

AbstractEs wird die Aufspaltung des Oxido‐Rings in 16.17α‐Oxido‐20‐ketopregnenen beschrieben, welche jedoch nur unter milden Bedingungen 16β.17α‐disubstituierte Verbindungen liefert. Diese lagern sich außerordentlich leicht zu D‐Homo‐steroiden um, welche z. Tl. mit den kürzlich von H. H. Inhoffen und Mitarbb. als 16β.17α‐Dioxy‐pregnene bzw. ihre Acetate formulierten Stoffen identisch sind. Unter energischen sauren Spaltungsbedingungen entstehen Δ13‐17β‐Methyl‐18‐nor‐17α‐pregnene. Auf Grund des Verhaltens unserer 16β.17α‐disubstituierten Pregnene werden modifizierte Strukturformeln für Nologenin und Pennogenin vorgeschlagen.
Bis‐[2.3‐o‐diphenylen‐tetrazoliumsalze]
Authors: Jerchel Dietrich , Fischer Hans 
Published: May 2007

AbstractAus Bis‐tetrazoliumverbindungen entstehen bei Belichtung mit UV‐Licht in glatter Reaktion Bis‐[2.3‐o‐diphenylen‐tetrazoliumsalze]. Durch Reduktion mit Natriumdithionit oder Hydrazin gehen sie in tiefgefärbte Radikale über. Die katalytische Hydrierung führt zu Diphenazonen.
Über die Reaktion des Acetylchlorids mit Arsen (III)‐oxyd und die Bildung des Methylen‐bis‐dichlorarsins
Authors: Gutbier Heiner , Plust Heinz‐Günther 
Published: May 2007

AbstractDurch massenspektrometrische Untersuchung ergibt sich, daß die Reaktion des Arsen (III)‐oxyds mit Acetylchlorid zu Arsen (III)‐chlorid, Arsentriacetat, Acetanhydrid und in geringem Ausmaß zu Acetato‐arsendichlorid führt. Aus dem Arsentriacetat, dessen Pyrolyse ebenfalls massenspektrometrisch verfolgt wurde, entsteht in Gegenwart von Acetylchlorid, Aluminium (III)‐chlorid und überschüssigem Arsen (III)‐chlorid das Methylen‐bis‐dichlorarsin, dessen Bildungsmechanismus diskutiert wird. Für die Darstellung des Methylen‐bis‐dichlorarsins aus Arsentriacetat wird eine Arbeitsvorschrift mitgeteilt.
Mannich‐Basen als Zwischenprodukte bei der Umsetzung von CH‐aciden Verbindungen mit Formaldehyd und primären oder sekundären aromatischen Aminen zu kernsubstituierten Arylaminen
Authors: Thesing Jan , Zieg Hermann , Mayer Hans 
Published: May 2007

AbstractEs wird nachgewiesen, daß bei den im sauren Medium zu p‐substituierten Anilinen führenden Umsetzungen von Indol, Antipyrin bzw. β‐Naphthol mit Formaldehyd und Anilin oder Methylanilin zunächst die entspr. Mannich‐Basen entstehen, die dann unter dem Einfluß der Säure mit dem eingesetzten aromatischen Amin zu p‐substituierten Anilinen reagieren.
Progress in the Understanding of Drug–Receptor Interactions, Part 2: Experimental and Theoretical Electrostatic Moments and Interaction Energies of an Angiotensin II Receptor Antagonist (C30H30N6O3S)
Authors: Soave Raffaella , Barzaghi Mario , Destro Riccardo 
Published: May 2007

AbstractA combined experimental and theoretical charge density study of an angiotensin II receptor antagonist (1) is presented focusing on electrostatic properties such as atomic charges, molecular electric moments up to the fourth rank and energies of the intermolecular interactions, to gain an insight into the physical nature of the drug–receptor interaction. Electrostatic properties were derived from both the experimental electron density (multipole refinement of X‐ray data collected atT=17 K) and the ab initio wavefunction (single molecule and fully periodic calculations at the DFT level). The relevance of S⋅⋅⋅O and S⋅⋅⋅N intramolecular interactions on the activity of1is highlighted by using both the crystal and gas‐phase geometries and their electrostatic nature is documented by means of QTAIM atomic charges. The derived electrostatic properties are consistent with a nearly spherical electron density distribution, characterised by an intermingling of electropositive and ‐negative zones rather than by a unique electrophilic region opposed to a nucleophilic area. This makes the first molecular moment scarcely significant and ill‐determined, whereas the second moment is large, significant and highly reliable. A comparison between experimental and theoretical components of the third electric moment shows a few discrepancies, whereas the agreement for the fourth electric moment is excellent. The most favourable intermolecular bond is show to be an NH⋅⋅⋅N hydrogen bond with an energy of about 50 kJ mol−1. Key pharmacophoric features responsible for attractive electrostatic interactions include CH⋅⋅⋅X hydrogen bonds. It is shown that methyl and methylene groups, known to be essential for the biological activity of the drug, provide a significant energetic contribution to the total binding energy. Dispersive interactions are important at the thiophene and at both the phenyl fragments. The experimental estimates of the electrostatic contribution to the intermolecular interaction energies of six molecular pairs, obtained by a new model proposed by Spackman, predict the correct relative electrostatic energies with no exceptions.
The Mechanism of CX (X=F, Cl, Br, and I) Bond Activation in CX4 by a Stabilized Dialkylsilylene
Authors: Chen Chi‐Hui , Su Ming‐Der 
Published: May 2007

AbstractThe potential‐energy surfaces for the abstraction and insertion reactions of dialkylsilylene with carbon tetrahalides (CX4) have been characterized in detail using density functional theory (B3LYP), including zero‐point corrections. Four CX4 species, CF4, CCl4, CBr4, and CI4, were chosen as model reactants. The theoretical investigations described herein suggest that of the three possible reaction paths, the one‐halogen‐atom abstraction (X abstraction), the one‐CX3‐group abstraction (CX3 abstraction), and the insertion reaction, the X‐abstraction reaction is the most favorable, with a very low activation energy. However, the insertion reaction can lead to the thermodynamically stable products. Moreover, for a given stable dialkylsilylene, the chemical reactivity has been found to increase in the order CF4≪CCl4<CBr4<CI4, that is, the heavier the halogen atom (X), the more facile is its reaction with a stable dialkylsilylene. In particular, halogen abstraction is always predicted to be much more favorable than abstraction of a CX3 group from both energetic and kinetic viewpoints. In brief, electronic as well as steric factors play a crucial role in determining the chemical reactivity of the haloalkane species, kinetically as well as thermodynamically. Our conclusions based on the results of our theoretical investigations are in accordance with available experimental observations. Furthermore, a configuration‐mixing model based on the work of Pross and Shaik has been used to rationalize the computational results. The results obtained allow a number of predictions to be made.
Evidence for a SN2‐Type Pathway for Phosphine Exchange in Phosphine–Phosphenium Cations, [R2PPR′3]+
Authors: Slattery John M. , Fish Cheryl , Green Michael , Hooper Thomas N. , Jeffery John C. , Kilby Richard J. , Lynam Jason M. , McGrady John E. , Pantazis Dimitrios A. , Russell Christopher A. , Willans Charlotte E. 
Published: May 2007

AbstractAbstraction of a Cl− ion from the P‐chlorophospholes, R4C4PCl (R=Me, Et), produced the PP bonded cations [R4C4PP(Cl)C4R4]+, which reacted with PPh3 to afford X‐ray crystallographically characterised phosphine–phosphenium cations [R4C4P(PPh3)]+ (R=Me, Et). Examination of the 31P‐{1H} NMR spectrum of a solution (CH2Cl2) of [Et4C4P(PPh3)]+ and PPh3 revealed broadening of the resonances due to both free and coordinated PPh3, and importantly it proved possible to measure the rate of exchange between PPh3 and [Et4C4P(PPh3)]+ by line shape analysis (gNMR programmes). The results established second‐order kinetics with ΔS≠=(−106.3±6.7) J mol−1 K−1, ΔH≠=(14.9±1.6) kJ mol−1 and ΔG≠ (298.15 K)=(46.6±2.6) kJ mol−1, values consistent with a SN2‐type pathway for the exchange process. This result contrasts with the dominant dissociative (SN1‐type) pathway reported for the analogous exchange reactions of the [ArNCH2CH2N(Ar)P(PMe3)]+ ion, and to understand in more detail the factors controlling these two different reaction pathways, we have analysed the potential energy surfaces using density functional theory (DFT). The calculations reveal that, whilst phosphine exchange in [Et4C4P(PPh3)]+ and [ArNCH2CH2N(Ar)P(PMe3)]+ is superficially similar, the two cations differ significantly in both their electronic and steric requirements. The high electrophilicity of the phosphorus center in [Et4C4P]+, combined with strong π–π interactions between the ring and the incoming and outgoing phenyl groups of PPh3, favours the SN2‐type over the SN1‐type pathway in [Et4C4P(PPh3)]+. Effective π‐donation from the amide groups reduces the intrinsic electrophilicity of [ArNCH2CH2N(Ar)P]+, which, when combined with the steric bulk of the aryl groups, shifts the mechanism in favour of a dissociative SN1‐type pathway.
Synthesis, Characterization, and Electrochemiluminescence of Luminol‐Reduced Gold Nanoparticles and Their Application in a Hydrogen Peroxide Sensor
Authors: Cui Hua , Wang Wei , Duan Chun‐Feng , Dong Yong‐Ping , Guo Ji‐Zhao 
Published: May 2007

AbstractIt was found that chloroauric acid (HAuCl4) could be directly reduced by the luminescent reagent luminol in aqueous solution to form gold nanoparticles (AuNPs), the size of which depended on the amount of luminol. The morphology and surface state of as‐prepared AuNPs were characterized by transmission electron microscopy, UV/visible spectroscopy, X‐ray photoelectron spectroscopy, FTIR spectroscopy, and thermogravimetric analysis. All results indicated that residual luminol and its oxidation product 3‐aminophthalate coexisted on the surface of AuNPs through the weak covalent interaction between gold and nitrogen atoms in their amino groups. Subsequently, a luminol‐capped AuNP‐modified electrode was fabricated by the immobilization of AuNPs on a gold electrode by virtue of cysteine molecules and then immersion in a luminol solution. The modified electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. The as‐prepared modified electrode exhibited an electrochemiluminescence (ECL) response in alkaline aqueous solution under a double‐step potential. H2O2 was found to enhance the ECL. On this basis, an ECL sensor for the detection of H2O2 was developed. The method is simple, fast, and reagent free. It is applicable to the determination of H2O2 in the range of 3×10−7–1×10−3 mol L−1 with a detection limit of 1×10−7 mol L−1 (S/N=3).
Mechanisms for the Dehydrogenation of Alkanes on Platinum: Insights Gained from the Reactivity of Gaseous Cluster Cations, Ptn+n=1–21
Authors: Adlhart Christian , Uggerud Einar 
Published: May 2007

AbstractRates for the dihydrogen elimination of methane, ethane, and propane with cationic platinum clusters, Ptn+ (1≤n≤21), were measured under binary collision conditions in a Fourier transform ion cyclotron resonance mass spectrometer (FTICR). The reaction rate for a given cluster, Ptn+, follows the trend k(CH4)<k (C2H6)<k(C3H8). Methane is particular in the sense that reactivity is highly variable; some clusters (n=1–3, 5–9, 11, 12, 15) are very reactive towards methane, while all other clusters react with low efficiency or not at all. For propane, all clusters react efficiently, while the reactivity of ethane lies in‐between that of methane and propane. By necessity, dihydrogen elimination of methane occurs according to a 1,1‐elimination mechanism. Ethane dehydrogenation takes place according to both a 1,1‐ and a 1,2‐mechanism. The difference between the 1,1‐ and 1,2‐mechanisms is well displayed in specifically increased rates for those clusters that were inefficient in the reaction with methane, as well as in the observed selectivity for H2, HD, and D2 elimination in the reaction with [D3]‐1,1,1‐ethane. Some twofold dihydrogen elimination is observed as well. The outcome of reactions with C2H6 in the presence of D2 demonstrates exchange of all hydrogen atoms in [PtnC2H4]+ with deuterium atoms. A potential energy diagram with a high barrier for the second H2 elimination summarizes these observations. For propane twofold dihydrogen elimination is dominating, and for these reactions a far less regiospecific and more random loss of the hydrogens can be inferred, as was demonstrated by the reactions with [D6]‐1,1,1,3,3,3‐propane.
Are MAP Kinases Drug Targets? Yes, but Difficult Ones
Authors: Margutti Simona , Laufer Stefan A. 
Published: May 2007

AbstractPharmaceutical companies are facing an increasing interest in new target identification and validation. In particular, extensive efforts are being made in the field of protein kinase inhibitors research and development, and the past ten years of effort in this field have altered our perception of the potential of kinases as drug targets. Therefore, in the drug discovery process, the selection of relevant, susceptible protein kinase targets combined with searches for leads and candidates have become a crucial approach. The success of recent launches of protein kinase inhibitors (Gleevec, Imatinib, Sutent, Iressa, Nexavar, Sprycel) gave another push to this field. Numerous other kinase inhibitors are currently undergoing clinical trials or clinical development. Some questions are nevertheless unanswered, mostly related to the great number of known kinases in the human genome, to their similarity with each other, to the existence of functionally redundant kinases for specific pathways, and also because the connection between particular pathways and diseases is not always clear. The review is leading the reader through a panoramic view of protein kinase inhibition with a major focus on MAPK, successful examples and clinical candidates.
Oxime and Oxime Ether Derivatives of 1,4‐Benzothiazine Related to Oxiconazole
Authors: Milanese Lara , Giacchè Nicola , Schiaffella Fausto , Vecchiarelli Anna , Macchiarulo Antonio , Fringuelli Renata 
Published: May 2007

AbstractThe synthesis, in vitro antifungal activity, and molecular docking experiments of some oxime and oxime ether derivatives of azole 1,4‐benzothiazine are reported herein, with the aim of evaluating the influence of a partially constrained scaffold that is structurally related to Oxiconazole and bearing the 1,4‐benzothiazine moiety, on the inhibition of Candida albicans CYP51.
Antibody‐mediated cell labeling of peripheral T cells with micron‐sized iron oxide particles (MPIOs) allows single cell detection by MRI
Authors: Shapiro Erik M. , Medford‐Davis Laura N. , Fahmy Tarek M. , Dunbar Cynthia E. , Koretsky Alan P. 
Published: May 2007

AbstractLabeling cells with iron oxide is a useful tool for MRI based cellular imaging. Here it is demonstrated that peripheral rat T cells can be labeled in whole blood, in vitro, with streptavidin‐coated micron‐sized iron oxide particles (MPIOs), achieving iron concentrations as high as 60 pg iron per cell. This is 30 times the amount of labeling reported with ultrasmall particles of iron oxide (USPIOs). Labeling was mediated by use of a biotinylated anti‐CD5 antibody, which is specific for peripheral T cells. Such labeling allowed the in vitro detection of single lymphocytes by MRI, using conditions well suited for in vivo animal work. Electron microscopic analysis demonstrated that MPIOs remained largely extracellular after labeling, with some evidence of intracellular uptake. Cell viability and early and late cytokine release studies showed no significant differences between labeled and unlabeled cells. Therefore, the use of MPIOs for achieving high iron concentrations for cellular MRI is potentially an effective new modality for non‐invasive imaging of lymphocytes. Published in 2007 by John Wiley & Sons, Ltd.
Non‐Hodgkin lymphoma of the breast
Authors: Ganjoo Kristen , Advani Ranjana , Mariappan M. Rajan , McMillan Alex , Horning Sandra 
Published: May 2007

AbstractBACKGROUND.Primary lymphoma of the breast has been reported to have a high local and central nervous system recurrence (CNS) rate, suggesting the need for consolidation radiotherapy and CNS prophylaxis. A retrospective study was done to evaluate the institutional experience in this patient population.METHODS.In all, 37 patients with lymphoma involving the breast at initial diagnosis and managed at Stanford University from 1981–2005 were included. Diagnostic tissue biopsies were obtained either from the breast mass or an involved lymph node. Treatment and response data, patterns of recurrence, and outcomes were reviewed.RESULTS.Diffuse large B cell lymphoma (DLBCL) was the most common histologic subtype seen in 18 of 37 (49%) patients. Follicular and marginal zone subtypes were seen in 38%. Most patients presented with an incidental breast mass in stage IE or IIE. Four (11%) patients presented with bilateral breast involvement, with only 1 patient presenting with CNS disease. DLBCL patients received doxorubicin‐based chemotherapy, with 70% receiving involved field radiotherapy and a single patient receiving intrathecal therapy. No recurrences occurred in the involved breast and a single parenchymal CNS recurrence was recorded. Among the DLBCL patients, the 5‐year progression‐free survival (PFS) was 61%, with a median follow‐up of 3.8 years (range, 5 months to 19 years) and the 5‐year overall survival (OS) was estimated at 82%. Patients with indolent lymphoma had an estimated 5‐year PFS of 76% and an OS of 92%.CONCLUSIONS.DLBCL of the breast was successfully treated with doxorubicin‐based chemotherapy alone or with involved field radiotherapy in an estimated 61% of patients at 5 years. A single CNS recurrence was observed in our series of patients, most of whom presented with limited disease. Cancer 2007. © 2007 American Cancer Society.
Micropapillary bladder cancer
Authors: Kamat Ashish M. , Dinney Colin P. N. , Gee Jason R. , Grossman H. Barton , Siefker‐Radtke Arlene O. , Tamboli Pheroze , Detry Michelle A. , Robinson Tracy L. , Pisters Louis L. 
Published: May 2007

AbstractBACKGROUNDMicropapillary bladder carcinoma is a rare variant of urothelial carcinoma. To improve understanding of this disease, the authors performed a retrospective review of their experience.METHODSThe authors reviewed the records of 100 consecutive patients with micropapillary bladder cancer who were evaluated at The University of Texas M. D. Anderson Cancer Center.RESULTSThe mean age of the patients was 64.7 years, with a male:female ratio of 10:1. The TNM stage of disease at the time of presentation was Ta in 5 patients, carcinoma in situ (CIS) in 4 patients, T1 in 35 patients, T2 in 26 patients, T3 in 7 patients, T4 in 6 patients; N+ in 9 patients, and M+ in 8 patients. Kaplan‒Meier estimates of 5‒year and 10‒year overall survival (OS) rates were 51% and 24%, respectively. Bladder‒sparing therapy with intravesical bacillus Calmette–Guerin therapy was attempted in 27 of 44 patients with nonmuscle‒invasive disease; 67% (18 patients) developed disease progression (≥cT2), including 22% who developed metastatic disease. Of 55 patients undergoing radical cystectomy for surgically resectable disease (≤cT4a), 23 received neoadjuvant chemotherapy and 32 were treated with initial cystectomy, with no significant difference noted in stage distribution between the 2 groups. For the 23 patients treated with neoadjuvant chemotherapy, the median OS was 43.2 months with 32% of patients still alive at 5 years. For the 32 patients treated with initial cystectomy, the median survival had not been reached at the time of last follow‒up, with 71% still alive at 5 years.CONCLUSIONSMicropapillary bladder cancer is associated with a poor prognosis. Intravesical therapy appears to be ineffective in this disease and patients with surgically resectable disease should be offered early radical cystectomy. Cancer 2007. © 2007 American Cancer Society.
The value of combined‐modality therapy in elderly patients with stage III nonsmall cell lung cancer
Authors: Schild Steven E. , Mandrekar Sumithra J. , Jatoi Aminah , McGinnis William L. , Stella Phillip J. , Deming Richard L. , Jett James R. , Garces Yolanda I. , Allen Katie L. , Adjei Alex A. ,   for the North Central Cancer Treatment Group
Published: May 2007

AbstractBACKGROUND.The objective of this study was to assess the value of combined‐modality therapy in elderly patients by comparing the differences in outcome between patients who received radiotherapy (RT) alone and patients who received RT plus chemotherapy for stage III nonsmall cell lung cancer (NSCLC).METHODS.The North Central Cancer Treatment Group performed 2 recent Phase III trials for stage III NSCLC. The first trial, NCCTG 90‐24‐51, included 3 arms: once‐daily RT (QDRT) alone, twice‐daily RT (BIDRT) alone, and concurrent chemotherapy plus BIDRT. The second trial, NCCTG 94‐24‐52, included 2 arms and compared concurrent chemotherapy with either QDRT or BIDRT. The chemotherapy arms of both trials included etoposide and cisplatin administered concurrently with RT. Only the patients aged ≥65 years (elderly) who participated in those trials were included in this analysis.RESULTS.Of the 166 elderly patients who were included in this analysis, 37 patients received RT alone, and 129 patients received concurrent chemotherapy plus RT. The median and 5‐year survival rates were 10.5 months and 5.4% for the RT alone group compared with 13.7 months and 14.7% for the RT plus chemotherapy group (log‐rank P = .05). Patients who received RT plus chemotherapy experienced significantly greater severe toxicity (grade ≥3) compared with patients who received RT alone (89.9% vs 32.4%; P < 0.01).CONCLUSIONS.Elderly patients who participated in these trials appeared to gain a survival advantage from RT and chemotherapy compared with RT alone. As is the case with younger patients, this benefit came at the cost of additional toxicity. Cancer 2007. © 2007 American Cancer Society.
Multiscale algorithm with patches of finite elements
Authors: Picasso Marco , Rappaz Jacques , Rezzonico Vittoria 
Published: May 2007

AbstractWe develop a discretization and solution technique for elliptic problems whose solutions may present strong variations, singularities, boundary layers and oscillations in localized regions. We start with a coarse finite element discretization with a mesh sizeH, and we superpose to it local patches of finite elements with finer mesh sizeh≪ Hto capture local behaviour of the solution. The two meshes (coarse and patch) are not necessarily compatible. Similar to mesh adaptation methods, the location of the fine patches is identified by ana posteriorierror estimator. Unlike mesh adaptation, no remeshing is involved. We discuss the implementation and illustrate the method on an industrial example. Copyright © 2007 John Wiley & Sons, Ltd.