bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure‐Based Design of Platinum(II) Complexes as c‐myc Oncogene Down‐Regulators and Luminescent Probes for G‐Quadruplex DNA
Authors: Wang Ping , Leung Chung‐Hang , Ma Dik‐Lung , Yan Siu‐Cheong , Che Chi‐Ming 
Published: May 2010

AbstractA series of platinum(II) complexes with tridentate ligands was synthesized and their interactions with G‐quadruplex DNA within the c‐myc gene promoter were evaluated. Complex 1, which has a flat planar 2,6‐bis(benzimidazol‐2‐yl)pyridine (bzimpy) scaffold, was found to stabilize the c‐myc G‐quadruplex structure in a cell‐free system. An in silico G‐quadruplex DNA model has been constructed for structure‐based virtual screening to develop new PtII‐based complexes with superior inhibitory activities. By using complex 1 as the initial structure for hit‐to‐lead optimization, bzimpy and related 2,6‐bis(pyrazol‐3‐yl)pyridine (dPzPy) scaffolds containing amine side‐chains emerge as the top candidates. Six of the top‐scoring complexes were synthesized and their interactions with c‐myc G‐quadruplex DNA have been investigated. The results revealed that all of the complexes have the ability to stabilize the c‐myc G‐quadruplex. Complex 3 a ([PtIIL2R]+; L2=2,6‐bis[1‐(3‐piperidinepropyl)‐1H‐enzo[d]imidazol‐2‐yl]pyridine, R=Cl) displayed the strongest inhibition in a cell‐free system (IC50=2.2 μM) and was 3.3‐fold more potent than that of 1. Complexes 3 a and 4 a ([PtIIL3R]+; L3=2,6‐bis[1‐(3‐morpholinopropyl)‐1H‐pyrazol‐3‐yl]pyridine, R=Cl) were found to effectively inhibit c‐myc gene expression in human hepatocarcinoma cells with IC50 values of ≈17 μM, whereas initial hit 1 displayed no significant effect on gene expression at concentrations up to 50 μM. Complexes 3 a and 4 a have a strong preference for G‐quadruplex DNA over duplex DNA, as revealed by competition dialysis experiments and absorption titration; 3 a and 4 a bind G‐quadruplex DNA with binding constants (K) of approximately 106–107 dm3 mol−1, which are at least an order of magnitude higher than the K values for duplex DNA. NMR spectroscopic titration experiments and molecular modeling showed that 4 a binds c‐myc G‐quadruplex DNA through an external end‐stacking mode at the 3′‐terminal face of the G‐quadruplex. Intriguingly, binding of c‐myc G‐quadruplex DNA by 3 b is accompanied by an increase of up to 38‐fold in photoluminescence intensity at λmax=622 nm.
Nucleophilic Aromatic Addition Reactions of the Metallabenzenes and Metallapyridinium: Attacking Aromatic Metallacycles with Bis(diphenylphosphino)methane to Form Metallacyclohexadienes and Cyclic η2‐Allene‐Coordinated Complexes
Authors: Zhang Hong , Lin Ran , Hong Guangning , Wang Tongdao , Wen Ting Bin , Xia Haiping 
Published: May 2010

AbstractThe reactions of phosphonium‐substituted metallabenzenes and metallapyridinium with bis(diphenylphosphino)methane (DPPM) were investigated. Treatment of [Os{CHC(PPh3)CHC(PPh3)CH}Cl2(PPh3)2]Cl with DPPM produced osmabenzenes [Os{CHC(PPh3)CHC(PPh3)CH}Cl2{(PPh2)CH2(PPh2)}]Cl (2), [Os{CHC(PPh3)CHC(PPh3)CH}Cl{(PPh2)CH2(PPh2)}2]Cl2 (3), and cyclic osmium η2‐allene complex [Os{CHC(PPh3)CH(η2‐CCH)}Cl2{(PPh2)CH2(PPh2)}2]Cl (4). When the analogue complex of osmabenzene 1, ruthenabenzene [Ru{CHC(PPh3)CHC(PPh3)CH}Cl2(PPh3)2]Cl, was used, the reaction produced ruthenacyclohexadiene [Ru{CHC(PPh3)CHC(PPh3)CH}Cl{(PPh2)CH2(PPh2)}2]Cl2 (6), which could be viewed as a Jackson–Meisenheimer complex. Complex 6 is unstable in solution and can easily be convert to the cyclic ruthenium η2‐allene complexes [Ru{CHC(PPh3)CH(η2‐CCH)}Cl{(PPh2)CH2(PPh2)}2]Cl2 (7) and [Ru{CHC(PPh3)CH(η2‐CCH)}Cl2{(PPh2)CH2(PPh2)}2]Cl (8). The key intermediates of the reactions have been isolated and fully characterized, further supporting the proposed mechanism for the reactions. Similar reactions also occurred in phosphonium‐substituted metallapyridinium [OsCl2{NHC(CH3)C(Ph)C(PPh3)CH}(PPh3)2]BF4 to give the cyclic osmium η2‐allene‐imine complex [OsCl2{NHC(CH3)C(Ph)(η2‐CCH)}{(PPh2)CH2(PPh2)}(PPh3)]BF4 (11).
Synthese mikroporöser Kohlenstoffschäume für katalytische Anwendungen
Authors: Etzold B. , Glenk F. , Schirmer M. , Gütlein S. 
Published: May 2010

AbstractMikroporöse Kohlenstoffschäume wurden über die Chlorierung von Carbiden zur Verwendung als strukturierte Katalysatorträger hergestellt. Die selbsttragenden Strukturen zeigten eine enge Mikroporenverteilung, welche Formselektivität induzieren können. Die Eignung dieser Materialien als Katalysatorträger wurde durch Nassimprägnierung von Pulver mit Platin und die Verwendung in einer Modellhydrierung von Olefinen getestet. Es ist anzunehmen, dass die Ergebnisse der Nassimprägnierung und Hydrierung auf Kohlenstoffschaumstrukturen übertragbar sind.
Zeolithkatalyse für die nachhaltige Chemie
Authors: Reschetilowski W. 
Published: May 2010

AbstractIn einer Zeit der begrenzten Verfügbarkeit von Erdöl, Erdgas und Kohle verbunden mit deren gleichzeitig steigendem Weltbedarf wird der Einsatz von alternativen Rohstoffen in der chemischen Industrie unumgänglich. Eine sich anbietende reale Strategie zur Deckung der Bedürfnisse hinsichtlich der benötigten Chemieprodukte und Kraftstoffe stellt die stoffliche Nutzung der Biomasse dar. Bei der Entwicklung neuer katalytischer Verfahren der Stoffwandlung unter Verwendung biobasierter Rohstoffe können wir von den Erfahrungen der modernen Chemieindustrie profitieren, in der viele stoffwandelnde Prozesse mit hocheffektiven Katalysatoren auf der Basis von Zeolithen oder zeolithähnlichen Materialien erfolgreich verlaufen und deshalb auch in Zukunft richtungsweisend bleiben. Anhand ausgewählter aktueller Beispiele werden die bereits erzielten Erfolge der neuen Strategie hinsichtlich des wissenschaftlichen und technischen Fortschritts beim Übergang vom „schwarzen zum grünen Gold”︁ demonstriert.
Zeolithe als Sorptionsmittel
Authors: Unger B. , Schumann K. , Brandt A. 
Published: May 2010

AbstractZeolithe bzw. zeolithische Molekularsiebe gehören zu den derzeit bedeutendsten technischen Adsorptionsmitteln. Die Adsorption stellt eine Alternativmöglichkeit zum Trennen von Stoffgemischen oder Reinigen von Stoffen dar. Bei der Stofftrennung durch Adsorption an zeolithischen Molekularsieben nutzt man sowohl die geometrischen als auch die elektronischen Unterschiede der zu trennenden Komponenten aus, wobei ein wesentlicher Vorteil von Zeolithen die Variabilität der Porengrößen ist. Zeolithische Systeme sind auch als Materialien zur Wärme‐ und Kälteerzeugung und zur Energiespeicherung geeignet. In diesem Artikel soll ein praxisorientierter Überblick aus der Sicht der für die Adsorption wichtigsten Zeolithe und deren vielseitige Einsatzgebiete gegeben werden
Neue nanoporöse Molekularsiebmembranen: Zeolithe contra MOFs – Gewinner und Verlierer
Authors: Caro J. 
Published: May 2010

AbstractSowohl Zeolith‐ als auch MOF (metal organic framework)‐Membranen sind potentiell in der Lage, ein fluides Gemisch nach Größe und Gestalt der Komponenten aufzutrennen und werden daher als Molekularsiebmembranen bezeichnet. In den letzten Jahren wurden wesentliche Fortschritte bei der Synthese, Charakterisierung und Anwendung von Zeolithmembranen erzielt. Dennoch sind die Fortschritte bei der Einführung von Zeolithmembranen in die industrielle Trenntechnik eher gering. Durch Anwendung der bei der Entwicklung von Zeolithmembranen entwickelten Präparationstechniken wie Seeding, Einsatz grobporöser Träger, Einstellen von Zeta‐Potenzialen während der Synthese, Mikrowellenheizen etc. konnten in vergleichsweise kurzer Zeit wesentliche Fortschritte bei der Entwicklung von MOF‐Molekularsiebmembranen erzielt werden. Als metall‐organisches Hybrid besitzen MOFs eine Reihe anwendungstechnischer Vorzüge, die ihren technischen Einsatz als Gastrennmembran aussichtsreich erscheinen lassen.
Zirkoniumdioxid mit definierter Partikelmorphologie und hierarchisch strukturiertem Porensystem durch kombinierte Exo‐ und Endotemplatsynthese
Authors: Gläser R. , Heinrich A. , With P. , Lutecki M. , Fichtner S. , Böhringer B. 
Published: May 2010

AbstractZirkoniumdioxid ist nicht nur thermisch und meachnisch sehr stabil, sondern kann auch mit großer spezifischer Oberfläche und großem spezifischen Porenvolumen hergestellt werden. Dadurch ist es als Katalysatorträger interessant. Die Herstellung von Partikeln mit größeren Abmessungen gelingt über Exotemplatsynthese unter Verwendung von Aktivkohle mit kugelförmigen Partikeln. Der Zusatz eines Endotemplats erzeugt ein zusätzliches Mesoporensytem, so dass Zirkoniumdioxid mit hierarchisch strukturiertem Porensystem und zugleich definierter Partikelmorphologie zugänglich wird.
Mesoporöse Glasmembranen als Modellsysteme zur Untersuchung der Gasdiffusion durch poröse Medien
Authors: Stoltenberg D. , Enke D. , Seidel‐Morgenstern A. 
Published: May 2010

AbstractPoröse Gläser in Form von Monolithen eignen sich auf Grund ihrer speziellen Eigenschaften als Modellsystem zur Untersuchung von porengrößenabhängigen Effekten. In dieser Studie wurde die Gaspermeation verschiedener adsorbierbarer und nicht adsorbierbarer Gase durch neue mesoporöse Glasmembranen untersucht. Dazu wurden Einzelgasmessungen mit einer modifizierten Wicke‐Kallenbach‐Zelle durchgeführt. Durch die Modifizierung der inneren Oberfläche der Glasmembranen war es möglich die Adsorptions‐ und Diffusionseigenschaften der Membranen zu beeinflussen.
Network models for capillary porous media: application to drying technology
Authors: Metzger T. , Tsotsas E. 
Published: May 2010

AbstractNetwork models offer an efficient pore‐scale approach to investigate transport in partially saturated porous materials and are particularly suited to study capillarity. Drying is a prime model application since it involves a range of physical effects: capillary pumping, viscous liquid flow, phase transition, vapor diffusion, heat transfer, but also cracks and shrinkage. This review article gives an introduction to this modern technique addressing required model input, sketching important elements of the computational algorithm and commenting on the nature of simulation results. For the case of drying, it is illustrated how network models can help analyze the influence of pore structure on process kinetics and gain a deeper understanding of the role of individual transport phenomena. Finally, a combination of pore network model and discrete element method is presented, extending the application range to mechanical effects caused by capillary forces.
Spektroskopische Charakterisierung von porösen Materialien – Stand der Technik und Zukunftsperspektiven
Authors: Hartmann M. 
Published: May 2010

AbstractSpektroskopische Methoden werden vielfältig zur Charakterisierung von porösen Materialien wie Zeolithen, Alumophosphaten, mesoporösen Silicaten und porösen Koordinationspolymeren (MOFs) im Hinblick auf strukturelle und physico‐chemische Eigenschaften eingesetzt. Dieser Beitrag gibt einen Überblick über die zur Verfügung stehenden Methoden und die gewinnbaren Informationen insbesondere im Hinblick auf den Einsatz dieser Materialien als Asorbentien und Katalysatoren.
Metallorganische Gerüstverbindungen (MOFs)
Authors: Kaskel S. 
Published: May 2010

AbstractBei der Suche nach immer neuen Adsorbentien mit höheren spezifischen Oberflächen und neuen Funktionalitäten haben insbesondere metallorganische Gerüstverbindungen (Metal‐Organic Frameworks, MOFs) zu enormen Fortschritten beigetragen. Als Applikationen werden heute Gasspeicherung, Gastrennprozesse, Medizintechnik bis hin zu Biomaterialien und Sensorik, aber auch Katalysatoren diskutiert. Daneben existieren auch funktionelle Nischen im Bereich der Optoelektronik, magnetische und ferroelektrische Eigenschaften sind noch wenig erforscht. MOFs sollten nicht als Substituenten für Zeolithe diskutiert werden. Ihre Stärke liegt in der extrem großen Porosität in Kombination mit molekularen Baugruppen, die spezifische Interaktionen mit zu adsorbierenden Molekülen eingehen können. Die modularen Konstruktionsprinzipien der MOFs werden auch auf andere Materialklassen zunehmend übertragen.
The Effect of Sleep Apnea on QT Interval, QT Dispersion, and Arrhythmias
Authors: Barta Kitti , Szabó Zoltán , Kun Csaba , Munkácsy Csaba , Bene Orsolya , Tünde Magyar Mária , Csiba László , Lörincz István 
Published: May 2010

AbstractBackgroundQT interval (QT) and QT dispersion (QTd) are electrocardiograph (ECG) parameters for the evaluation of myocardial repolarization. The inhomogeneity of ventricular repolarization is associated with ventricular arrhythmias. An increased QT, QTd, and increased incidence of nocturnal cardiac rhythm disturbances have been described in patients with obstructive sleep apnea (OSA), while other investigators did not find a relationship between ventricular arrhythmias and OSA.HypothesisThe aim of this study was to examine the occurrence of ventricular arrhythmias and to measure QT parameters in patients with untreated OSA using an ambulatory Holter‐ECG.MethodsA total of 25 patients with untreated OSA were studied. After routine biochemical investigation and 2‐dimensional, M‐mode echocardiography, a 24‐hour Holter‐ECG was recorded to detect cardiac arrhythmias and QT parameters. QT parameters were measured by the QT Guard system.ResultsOnly the QT interval increased significantly during the nighttime period (nocturnal QT interval: 423.1 ± 34.6 ms, daytime QT interval: 381.6 ± 33.8 ms, 24‐hour QT interval: 394.7 ± 31.1 ms). However, during the nighttime QT interval (422.8 ± 14.9 ms), QTd (31.2 ± 11.0 ms) and QT dispersion (30.5 ± 10.2 ms) did not show any change compared to 24‐hour (QTc interval: 423.7 ± 14.2 ms, QTd: 28.8 ± 9.4 ms, QTcd: 30.5 ± 9.43 ms) and daytime levels (QTc interval: 423.9 ± 14.3 ms, QTd: 27.3 ± 10.7 ms, QTcd: 29.9 ± 11.1 ms). None of the patients had ventricular arrhythmias.ConclusionsQTd and QTcd did not increase during the nighttime period. Our study did not show an increased risk of ventricular arrhythmias in this population during the monitoring period. Copyright © 2010 Wiley Periodicals, Inc.
Safety of Selective Serotonin Reuptake Inhibitor Use Prior to Coronary Artery Bypass Grafting
Authors: Xiong Glen L. , Jiang Wei , Clare Robert M. , Shaw Linda K. , Smith Peter K. , O'Connor Christopher M. , Ranga K. , Krishnan R. , Kristin Newby L. 
Published: May 2010

AbstractBackgroundSelective serotonin reuptake inhibitors (SSRIs) have been shown to increase bleeding risks. This study examined the association of perioperative coronary artery bypass grafting (CABG) bleeding risks and SSRI use prior to CABG.HypothesisSSRI may be associated with increased bleeding risks after CABG resulting in elevated reoperation rates due to bleeding complications.MethodsPatients who underwent CABG between 1999 and 2003 (n = 4794) were identified in a tertiary medical center. SSRI use (n = 246) was determined using inpatient pharmacy records. Outcomes included primary end point of reoperation due to bleeding complications and other secondary measures. Multivariate regression models were constructed to adjust for baseline differences between SSRI and control groups.ResultsReoperation due to bleeding complications among SSRI users was not significantly different (odds ratio [OR]: 1.14 (0.52–2.47); P = 0.75) compared to the control group. Other secondary outcomes and 30‐day mortality (2.0% in SSRI vs 2.1% in control group; P = 0.92) between the 2 groups were similar. However, the adjusted total volume of postoperative red blood cell (RBC) units transfused was higher in the SSRI group.ConclusionWe conclude that there is no compelling evidence to limit the use of SSRIs among patients with coronary artery disease who undergo CABG given the current evidence. Further research may be needed on individual SSRI medications. Copyright © 2010 Wiley Periodicals, Inc.
Symptom Presentation in Patients Hospitalized with Acute Heart Failure
Authors: Goldberg Robert J. , Spencer Frederick A. , Szklo‐Coxe Mariana , Tisminetzky Mayra , Yarzebski Jorge , Lessard Darleen , Gore Joel M. , Gaasch William 
Published: May 2010

AbstractObjectivesThe objectives of this study were to examine the type and frequency of symptoms in patients hospitalized with acute heart failure (HF) as well as the relationship between symptom patterns and patient characteristics, treatment practices, and hospital outcomes in patients hospitalized with decompensated HF.MethodsThe study sample consisted of 4537 residents of the Worcester, MA metropolitan area hospitalized for decompensated HF at 11 greater Worcester medical centers in 1995 and 2000.ResultsThe average age of the study sample was 76 years; the majority (57%) were women, and three‐quarters of our patient population had been previously diagnosed with HF. Dyspnea (93%) was the most frequent complaint reported by patients followed by the presence of peripheral edema (70%), cough (51%), orthopnea (37%), and chest pain/discomfort (30%). Patients reporting few cardiac symptoms were less likely to be treated with effective cardiac therapies during hospitalization than patients with multiple cardiac signs and symptoms and experienced higher hospital (9.7% vs. 7.7%) as well as 30‐day (17.1% vs. 10.2%) death rates (P < 0.05).ConclusionsThe results of this study in residents of a large New England community suggest that patients with fewer reported symptoms of decompensated HF were less likely to receive effective cardiac treatments and had worse short‐term outcomes. Reasons for these differences in treatment practices and short‐term outcomes need to be elucidated and attention directed to these high‐risk patients. Copyright © 2010 Wiley Periodicals, Inc.
Subocclusion of the Sinus Node Artery During Coronary Angioplasty: Arrhythmological Considerations
Authors: D'Ascenzi Flavio , Iadanza Alessandro , Zacà Valerio , Pierli Carlo , Mondillo Sergio 
Published: May 2010

AbstractWe report the case of a 58‐year‐old man who developed atrial fibrillation as a result of iatrogenic subocclusion of a diseased sinus node artery, originating from the left circumflex artery (LCx), occurring during LCx stenting, suggestive of an ischemic etiology of sinus node dysfunction. Copyright © 2010 Wiley Periodicals, Inc.
Sinus Arrest due to Sertraline
Authors: Kocabay Gonenc , Yildiz Mustafa , Eksi Duran Nilufer , Ozkan Mehmet 
Published: May 2010

AbstractSertraline is a selective serotonin reuptake inhibitor with established safety for the treatment of depression. Among the common adverse effects associated with sertraline are nausea, insomnia, diarrhea, somnolence, and dizziness. Cardiac arrest had not been reported in the literature, although tachycardia was frequently seen. In this case report, a patient was presented who had adverse reactions such as nausea, dizziness, insomnia under citalopram treatment, and after his drug was changed to sertraline, developed sinus arrest on the fourth day of treatment. Copyright © 2010 Wiley Periodicals, Inc.
Improving Myocardial Perfusion by Percutaneous Coronary Intervention Reduces Central Sympathetic Activity in Stable Angina
Authors: Gomes Marc E. , Aengevaeren Wim R. , Lenders Jacques W. , Verheugt Freek W. , Smits Paul , Tack Cees J. 
Published: May 2010

AbstractBackgroundBy stimulating sympathetic afferents, repetitive myocardial ischemia induces a state of increased sympathetic tone.HypothesisRemoving the ischemic trigger by revascularization using percutaneous coronary intervention (PCI) might thus reduce central sympathetic activity in symptomatically stable angina patients.MethodsA total of 20 patients with stable angina ≥ New York Heart Association (NYHA) class II with persistent symptoms despite maximal pharmacological therapy and a clinical indication for PCI, were included in our study. Sympathetic nervous system activity was measured before and 1 month after PCI by a combination of techniques: direct muscle sympathetic nerve activity (MSNA), neurochemical (plasma catecholamine levels), and heart rate variability (HRV).ResultsAll patients completed the study. After PCI there was a significant reduction in MSNA (pre‐PCI 72 ± 4 to post‐PCI 53 ± 4 burst/100 beats, P < .05) and low frequency/high frequency (LF/HF) ratio (3.7 ± 0.6 vs 2.4 ± 0.4, P < .05) consistent with a decline in sympathetic activity. Plasma norepinephrine levels were reduced after PCI, but this difference did not reach statistical significance (1.84 ± 0.17 vs 1.73 ± 0.13 nmol/L, P = not significant).ConclusionCoronary revascularization by PCI reduces sympathetic activity in patients with established myocardial ischemia. Copyright © 2010 Wiley Periodicals, Inc.
Prolonged Postsurgical Survival Without a Pulmonic Valve: Case Report and Review of the Literature
Authors: Te Charles C. , Bauer Christopher E. , Abu‐Fadel Mazen S. , Peyton Marvin , Sivaram C.A. 
Published: May 2010

AbstractPulmonic valve stenosis is usually congenital and causes right‐sided heart failure secondary to pressure overload. We report the case of a 56‐year‐old male with congenital pulmonary valve stenosis who presented with severe right heart failure 32 years after pulmonary valvectomy. He subsequently underwent pulmonary valve replacement and did well. Pulmonary valvectomy is an uncommon treatment for pulmonary stenosis and this is the longest documented survival of a patient without a pulmonic valve. Copyright © 2010 Wiley Periodicals, Inc.
Apolipoprotein E Polymorphism and the Characteristics of Diseased Vessels in Male Chinese Patients With Angiographic Coronary Artery Disease: A Case‐Case Study
Authors: Li Shao‐Sheng , Yang Jie , Li Lan‐Sun , Wang Hai‐Chang 
Published: May 2010

AbstractBackgroundVariations in the apolipoprotein E (apo E) gene may predict the incidence of coronary artery disease (CAD). However, the correlation between apo E polymorphism and the severity of CAD is still unclear.HypothesisApolipoprotein E polymorphism can predict CAD.MethodsUsed a case‐case study of 213 Chinese angiographically‐defined CAD patients who were screened for apo E genotypes. The characteristics of their diseased vessels were recorded.ResultsApolipoprotein E4 carriers had > 75% stenosis, more wide‐ranging and longer vessel disease, a greater number of diseased vessels, and a higher Gensini score than apo E2 carriers or individuals with the apo E3/3 genotype. Apolipoprotein E2 carriers had ≤75% stenosis and a shorter length of vessel disease than individuals with the apo E3/3 genotype or apo E4 carriers. The severity of stenosis, length of vessel disease, and number of diseased vessels were affected by the interaction between genotype and body mass index, family history of CAD, total plasma cholesterol level, smoking history, and hypertension history.ConclusionThe apo E4 allele may serve as an independent genetic marker predicting severity of CAD. Other CAD risk factors may accelerate the process of pathogenesis. The apo E2 allele may play a protective role. Copyright © 2010 Wiley Periodicals, Inc.