bluuebunny/crossref_metadata_2025_split huggingface dataset:
What Does it Really Take to Stabilize Complexes of Late Transition Metals with Terminal Oxo Ligands?
Authors: Limberg Christian 
Published: February 2009

AbstractSurprisingly stable: Noble‐metal complexes with terminal oxo ligands are frequently postulated as intermediates, but they are generally considered elusive, as their d electrons destabilize the MO units. Until recently, the isolation of such compounds was thought to require strong acceptor ligands, but now a remarkably stable PtO complex has been obtained employing a simple pincer ligand.magnified image
Ligand‐Stabilized Chalcogen Dications
Authors: Chivers Tristram , Konu Jari 
Published: February 2009

AbstractChalcogen‐transfer reagents? The bonding in the dicationic rings C2N2E2+ (see picture) differs from that in N‐heterocyclic carbenes and their isovalent p‐block analogues in accommodating a lone pair of electrons with π symmetry, as well as σ symmetry, on the chalcogen center. The labile electrophilic chalcogenium dications (E2+) are potentially versatile chalcogen‐transfer reagents in reactions with a variety of inorganic and organic substrates.magnified image
Morphology and rheological behavior of maltene–polymer blends. I. Effect of partial hydrogenation of poly(styrene‐block‐butadiene‐block‐styrene‐block)‐type copolymers
Authors: González‐Aguirre Paola , Medina‐Torres Luís , Schrauwen Cornelius , Fonteix Christian , Pla Fernand , Herrera‐Nájera Rafael 
Published: February 2009

AbstractBecause of the importance of the maltene–polymer interaction for the better performance of polymer‐modified asphalts, this article reports the effects of the molecular characteristics of two commercial poly(styrene‐block‐butadiene‐block‐styrene‐block) (SBS) polymers and their partially hydrogenated derivatives [poly{styrene‐block[(butadiene)1−x–(ethylene‐co‐butylene)x]‐block‐styrene‐block} (SBEBS)] on the morphology and rheological behavior of maltene–polymer blends (MPBs) with polymer concentrations of 3 and 10% (w/w). Each SBEBS and its parent SBS had the same molecular weight and polystyrene block size, but they differed from each other in the composition of the elastomeric block, which exhibited the semicrystalline characteristics of SBEBS. Maltenes were obtained from Ac‐20 asphalt (Pemex, Salamanca, Mexico), and the blends were prepared by a hot‐mixing procedure. Fluorescence microscopy images indicated that all the blends were heterogeneous, with polymer‐rich and maltene‐rich phases. The rheological behavior of the blends was determined from oscillatory shear flow data. An analysis of the storage modulus, loss modulus, complex modulus, and phase angle as a function of the oscillatory frequency at various temperatures allowed us to conclude that the maltenes behaved as pseudohomogeneous viscoelastic materials that could dissipate stress without presenting structural changes; moreover, all the MPBs were more viscoelastic than the neat maltenes, and this depended on both the characteristics and amount of the polymer. The MPBs prepared with SBEBS were more viscoelastic and possessed higher elasticity than those prepared with SBS. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Towards a metabolic and isotopic steady state in CHO batch cultures for reliable isotope‐based metabolic profiling
Authors: Deshpande Rahul , Yang Tae Hoon , Heinzle Elmar 
Published: February 2009

AbstractAttaining metabolic and isotopic balanced growth is one critical condition for physiological studies using isotope‐labeled tracers, but is very difficult to obtain in batch culture due to the extensive metabolite exchange with the surrounding medium and related physiological changes. In the present study, we investigated metabolic and isotopic behavior of CHO cells in differently designed media. We observed that the assumption of balanced cell growth cannot be justified in batch culture of CHO cells directly using conventional, commercially available media. By systematically redesigning media composition and characterizing metabolic steady state based on mass balances and measurement of labeling dynamics, we achieved balanced cell growth for the main cellular substrates in CHO cells. This was done in a step‐by‐step analysis of growth and primary metabolism of CHO cells with the use of [U‐13C]glucose feeding and adjusting concentrations of amino acids in the growth medium. The optimized media obtained at the end of the study provide balanced growth and isotopic steady state or at least asymptotic steady state. As a result, we established a platform to conduct isotope‐based physiological studies of mammalian systems more reliably and therefore well suited for later use in metabolic profiling of mammalian systems such as 13C‐labeled metabolic flux analysis.
Julius Adolph Stöckhardt. Zum 200. Geburtstag
Authors: Boeck Gisela 
Published: February 2009

AbstractJulius Adolph Stöckhardt, der den damals üblichen Weg vom Apotheker zum Chemiker ging, hat auf vielen Gebieten seine Spuren hinterlassen. Der Wegweiser seines Handelns war die Anwendbarkeit der chemischen Kenntnisse in der Praxis. Stöckhardt war einer der wichtigsten Popularisatoren der Agrikulturchemie, auf sein Bemühen geht im Wesentlichen die Gründung der landwirtschaftlichen Versuchsstationen zurück. Er hat sich mit Rauchgasen und Folgen für den Forst, mit der Giftigkeit von Farben auseinandergesetzt, zahllose analytische Untersuchungen – auch von Gesteinen – vorgenommen, über Methoden eines guten naturwissenschaftlichen Unterrichts nachgedacht und die Anerkennung der Chemie als allgemeines Bildungsmittel angestrebt. Im Andenken an diesen Gelehrten tragen heute das 1885 an der Forstakademie Tharandt erbaute, nun zur TU Dresden Fakultät für Forst‐, Geo‐ und Hydrowissenschaften gehörende Labor, der Chemnitzer Förderklub für chemieinteressierte Schülerinnen und Schüler, ein Chemiewettbewerb und ein jährlich an der Technischen Universität Chemnitz durchgeführtes Kolloquium zu Fragen der Umweltchemie seinen Namen.
Dramatische pH‐Änderung der Ozeane
Authors: Groß Michael 
Published: February 2009

AbstractDie Weltmeere haben bisher einen mildernden Einfluss auf den Klimawandel durch von Menschen freigesetztes Kohlendioxid ausgeübt. Schätzungsweise ein Drittel des seit Beginn der Industrialisierung erzeugten CO2‐Überschusses hat sich im Meer gelöst und trägt damit vorerst nicht zum Treibhauseffekt bei. Erst vor einigen Jahren haben Experten bemerkt, dass dieser scheinbar positive Effekt katastrophale Nebenwirkungen mit sich bringt.
Symbiose ersetzt den Darm
Authors: Feil Sylvia 
Published: February 2009

AbstractUnweit der Mittelmeerküste trifft man im Sediment auf Ringelwürmer, deren Darm sich aufgrund einer erfolgreichen symbiontischen Lebensweise mit Bakterien zurück gebildet hat. Dieser Wurm heißt Olavius algarvensis. Er gehört zu einer Gruppe von Oligochaeten des Stammes Annelida, die weder Mund noch Darm noch Anus haben: Ihr gesamtes Verdauungssystem ist reduziert.
Hydroxidionen bilden Wasserstoffbrücken
Authors: Harrer Roswitha 
Published: February 2009

AbstractDas Hydroxidion in wässriger Lösung ist eines der universellsten negativ geladenen Teilchen. Dennoch sind die Kenntnisse seiner Hydratisierungsstruktur und seines Transports in wässriger Lösung noch unvollständig. Jetzt wiesen Forscher zum ersten Mal nach, dass hydratisierte Hydroxidionen auf umgebene Wassermoleküle selbst Wasserstoffbrückenbindungen ausbilden – als Wasserstoffdonor.
Approaches to determination of left ventricular volume and ejection fraction by real‐time two‐dimensional echocardiography
Authors: Parisi A. F. , Moynihan P. F. , Feldman C. L. , Folland E. D. 
Published: February 2009

AbstractLeft ventricular volumes and ejection fraction were derived from real time two‐dimensional echocardio‐graphic images (2 DE) and single plane (RAO) left ventricular cineangiograms in a series of 50 patients. Prospective application of a series of 6 alternate algorithms showed that a modified Simpson's rule approach using mitral and papillary muscle cross sections and an apical four chamber view provided the best 2 DE — angiographic correlations: for end‐diastolic volume r = 0.82, SEE = 39 ml; for end‐systolic volume r = 0.90, SEE = 29 ml and for ejection fraction r = 0.80, SEE = 0.09. The large SEE for volume determination indicates that further refinements are necessary to predict left ventricular volumes adequately; however, ejection fraction can be derived with an accuracy which allows practical clinical decisions in patients with satisfactory 2 DE images.
Comparison of plasma concentrations of thromboxane B2 in prinzmetal's variant angina and classical angina pectoris
Authors: Lewy R. I. , Wiener L. , Smith J. B. , Walinsky P. , Silver M. J. , Saia J. 
Published: February 2009

AbstractWe have reported that thromboxane B2 is present in plasma of Prinzmetal's angina patients measured by radioimmunoassay but is below detection limits, <0.5 pmol/ml, in normals. To determine whether this metabolite of thromboxane A2 (a coronary vasoconstrictor) is present in the peripheral blood in classical angina pectoris, we studied 14 patients with fixed obstructive coronary artery disease (2.5 lesions per patient) in whom angina was induced by atrial pacing. Thromboxane B2 at rest was barely detectable (0.537±0.16 pmol/ml), but rose during pacing (0.747±0.18 pmol/ml) and was maximal (p<0.05) 5–10 min after pacing (1.237±0.36 pmol/ml). In eight variant angina patients, resting levels of thromboxane B2 were not statistically different during spontaneous angina and angina‐free intervals (2.837±0.56 and 1.577±0.34 pmol/ml), but the mean 5–10 min after angina was higher than during angina (6.41 7±1.46 pmol). The means of preanginal, anginal, and postanginal samples were all higher than the corresponding means of the classical angina group, and thromboxane B2 levels in variant angina patients in the absence of angina, during angina, and 5–10 min after angina were all significantly higher (p<0.025) compared to the classical angina group measured prior to pacing. Unlike the case with variant angina, thromboxane B2 is indetectable in classical angina pectoris patients at rest. Furthermore, spontaneous angina in variant angina or pacing‐induced angina in classical angina pectoris are both followed by increased thromboxane B2, although the latter responses are smaller. The role of these phenomena in the pathogenesis of coronary artery spasm and ischemia remains to be clarified.
Giant lambl's excrescences of papillary muscle and aortic valve: echocardiography, angiographic, and pathologic findings
Authors: Cha S. D. , Incarvito J. , Fernandez J. , Chang K. S. , Maranhao V. , Gooch A. S. 
Published: February 2009

AbstractA 54‐year‐old female with rheumatic heart disease was found to have a mass in the left ventricle by echocardiography and angiography. Subsequently, giant Lambl's excrescences of papillary muscle and aortic valve were confirmed by operation and pathologic examination. Possible complication from cardiac catheterization could be avoided by the utilization of echocardiography prior to catheterization.
Prostaglandin inhibition and myocardial infarct size
Authors: Jugdutt B. I. , Becker L. C. 
Published: February 2009

AbstractIn parallel with experimental research into methods for salvage of ischemic myocardium after acute myocardial infarction (AMI) over the last decade, there has been a growing interest in prostaglandins (PG) and their inhibition by aspirin‐like drugs or nonsteroidal anti‐inflammatory drugs (NSAID). The finding of enhanced PG release during myocardial ischemia and its blockade by the NSAID indomethacin led to the hypothesis that PG might influence the infarction process. Because PG differ in vasoactive, cellular, and metabolic properties, and PG inhibitors also differ in their ability to inhibit synthesis of different PG and their metabolites, some PG inhibitors might be expected to reduce myocardial ischemic injury and infarct size. In addition, the NSAID may directly modify cellular events during infarction. Experiments with NSAID in the anesthetized and conscious animals have demonstrated a reduction of myocardial infarct size with ibuprofen, but an increase in infarct size with indomethacin. The opposite effects of these agents on infarct size might have been related to the different doses used, different degrees of inhibition of PG and their metabolites, and different effects on factors influencing myocardial oxygen supply and demand, metabolic and cellular events during infarction. It has recently been suggested that some of these agents might also influence the healing process after AMI and, therefore, late complications. Thus, further critical studies are needed before embarking on clinical trials of these agents during AMI in humans
A Computerized approach to evaluating rest and exercise‐induced ecg/vcg changes after cardiac rehabilitation
Authors: Watanabe K. , Bhargava V. , Froelicher V. 
Published: February 2009

AbstractSummary: A computerized method of acquiring and analyzing rest and exercise test 12‐lead electrocardiographic and three‐dimensional lead vectorcardiographic data before and after cardiac rehabilitations is described. Fourteen coronary heart disease patients were exercise tested before and after a mean of five months of aerobic exercise training. The only significant ST‐segment improvements were found in three‐dimensional space. Spatial measurements should be considered in the assessment of electrocardiographic changes secondary to exercise training.
Echo‐ and electrocardiographic findings in relation to autopsy in myocardial infarction
Authors: Lindvall K. , Erhardt L. , Sjogren A. 
Published: February 2009

AbstractSummary: Left ventricular (LV) wall motion studied by echocardiography (Echo) may give additional information of site and extension of myocardial damage in myocardial infarction (MI) compared to conventional ECG. We have therefore investigated patients with apparent poor short‐term prognosis in the acute phase of an MI. Adequate autopsy data were available in 17 patients who died within a stipulated 2‐month period. The left ventricle was divided into 16 segments and concomitant evaluation with ECG and Echo was possible in 164 (56%) of 272 (16 × 17) segments. The Echo parameter mean systolic wall velocity (V) was used with its percent deviation (PD‐V) from that obtained in a healthy group. A reduction in PD‐V by 30% was used for separating healthy from infarcted segments. This limit gives the method a sensitivity (S) of 92%, specificity (SP) 66%, and predictive accuracy (PA) of 79% with highest PA for anterior and posteroseptal segments (78–87%) in contrast to inferior and lateral segments (73%). Sensitivity for single ECG leads is lower (76%) with SP and PA of 76 and 75%, respectively. PA was highest for an‐teroseptal and lateral segments (83%) as compared to 60% for inferoposterior segments. In 11 patients the MI was predominantly anterior which was adequately reflected by both Echo and ECG. Extension beyond this site was better evidenced by Echo than ECG. ECG was nondiagnostic in true posterior extension in contrast to Echo which was correct in all. In 6 patients the MI was predominantly inferior. Echo correctly identified this in 82% of segments and ECG in 71%. Again extensions beyond this site were better evidenced by Echo. Extensions to the true posterior and anterolateral walls were indicated in 79–100% by Echo, while ECG indicated MI in two posterior segments only. We conclude that Echo mapping provides useful information of segmental LV wall function in MI. In comparison to ECG additional information is obtained of MI involvement of especially the basal segments as well as the apical‐posteroseptal segments and also of extension beyond the conventional anterior and inferior locations.
Assessment of Diagnostic Value of Dipyridamole Testing in Angina Pectoris
Authors: Deambroggi L. , Barbieri P. , Debiash A. M. , Repetto S. , Radice M. 
Published: February 2009

AbstractSummary: In order to assess the diagnostic value of dipyridamole (D) testing, we studied the responses of 34 patients with chest pain and 10 normal subjects. Blood pressure and 12‐lead ECG were recorded during and after intravenous infusion of 0.6 mg/kg dipyridamole for 10 minutes. Coronary arteriography and maximal or symptom‐limited exercise tests were performed in the 34 patients with chest pain. During infusion 13 patients presented ischemic ST changes and 5 with anginal pain only. The latter group had normal coronary arteries. Among the 13 patients with ischemic ST changes, 7 had at least two critical coronary stenoses and the remaining 6 had no coronary lesions. Dipyridamole tests showed poor sensitivity (44%) and specificity (39%) with respect to coronary arteriography. The relatively high number of positive responses in subjects with normal coronary arteries indicates that the coronary steal phenomenon is not the sole cause of “ischemic” response to the drug. Indirect indexes of myocardial oxygen consumption were higher in patients with a positive response to drug infusion than in those with a negative response; however the value of rate‐pressure product at infusion end never reached that observed at ischemic threshold during exercise testing in the same patient. This suggests that neither can oxygen consumption increase be considered as entirely responsible for ischemic response to dipyridamole. In conclusion dipyridamole test cannot be proposed for predicting critical coronary stenoses.
Propranolol effects on autonomic function in hypertensive men
Authors: O'Connor D. T. , Preston R. A. 
Published: February 2009

AbstractSummary: Beta blocker antihypertensive effects are incompletely understood, and may involve alterations in the autonomic nervous system. We studied autonomic function in 12 essential hypertensive men during treatment with placebo and chronic oral propranolol. Propranolol reduced blood pressure and heart rate (both p<0.01) with an associated increase in baroreflex sensitivity during phenylephrine testing (p<0.02), though amyl nitrite‐tested baroreflex sensitivity was unchanged; blood pressure decrement did not correlate with baroreflex enhancement. Response to the cold pressor test and the blood pressure decrement to phentolamine alpha blockade were unaltered by propranolol, suggesting unchanged efferent sympathetic function; nor were several biochemical indices of sympathetic nervous activity influenced by propranolol. Propranolol does perturb autonomic function in man, but the perturbations do not correlate with blood pressure decrement; nor are physiologic or biochemical indices of efferent sympathetic activity reduced by propranolol.
Primary versus secondary mitral valve prolapse: Clinical features and implications
Authors: Levine H. J. , Isner J. M. , Salem D. N. 
Published: February 2009

AbstractSummary: This study considers the implications that two types of mitral valve prolapse exist. One is primary, and consists of a basic abnormality of the mitral apparatus. While the etiology of this lesion may not always be the same, the major gross abnormalities are usually constant. Secondary mitral valve prolapse generally exists merely as a consequence of reduced or abnormal ventricular dimensions, and usually appears to be a benign phenomenon.
Ventricular septal defect and mitral regurgitation complicating acute myocardial infarction
Authors: Corbally F. , Lowney J. D. , Schiff S. , Gottlieb R. , Papa L. A. 
Published: February 2009

AbstractWe report a case of rare incidence of both ventricular septal rupture and mitral regurgitation that followed an acute myocardial infarction in a 77‐year‐old woman. The literature contains few reports of such cases. The following reports both events and the progression of the clinical events.
Prolonged persistence of a large pericardial effusion and hemodynamic evidence of cardiac tamponade during treatment of myxedema
Authors: Das S. , Lieberman A. N. , Schussler G. C. 
Published: February 2009

AbstractWe describe clinical, echocardiographic, and catheterization findings that were present initially and during therapy in a myxedematous patient with a large pericardial effusion and tamponade. Treatment with thyroxine resulted in a marked improvement of most of the clinical features of hypothyroidism and some improvement in cardiac function. However, the pericardial effusion as well as clinical and laboratory evidence of tamponade persisted for 2 months after full replacement doses of T4 had been achieved. The tamponade was finally relieved by fenestration of the parietal pericardium. These findings are consistent with evidence of an abnormality of pericardial drainage that persists for months after other thyroid hormone dependent functions are normalized by thyroxine replacement. Therefore prompt surgical drainage rather than dependence on medical therapy alone is indicated in myxedematous patients who have cardiac tamponade.
The pulmonary circulation and its systemic arterial supply in pulmonary atresia
Authors: Schneeweiss A. , Shem‐Tov A. , Dicker D. , Blieden L. C. , Deutsch V. , Neufeld H. N. 
Published: February 2009

AbstractThe pulmonary circulation and its systemic arterial supply in cases of pulmonary atresia were studied angiocardiographically. In 69% of the cases the pulmonary arteries were hypoplastic and supplied by a patent ductus arteriosus or a few large systemic arteries. A classification into four groups is suggested, and a developmental paradox represented by this classification is discussed.
Suppression of ventricular arrhythmia by acebutolol
Authors: Santoso T. , Nursyirwan E. F. , Trisnohadi H. B. , Manurung D. , Rahman A. M. , Abdurahman N. 
Published: February 2009

AbstractTo study the efficacy of acebutolol in suppressing ventricular arrhythmia, 20 consecutive patients with more than 10 premature ventricular contractions (PVCs) per hour (averaged over 24 hours) were studied. Arrhythmias were not precipitated either by remediable clinical conditions or acute myocardial infarction. Digitalis and antiarrhythmic drugs were discontinued at least 5 days prior to entry into the trial. Besides routine clinical, laboratory, and ECG examinations, all patients also underwent serial 24‐h Holter monitoring every 10 days and echocardiographic examinations before and 20 days after treatment. The total duration of the trial was 30 days. The dosage of acebutolol was 400 mg/d during the first 10 days and was increased to 600 mg/d in the next 10 days as necessary, provided also that no significant side effects occurred. The drug was withdrawn for the last 10 days in order to establish drug withdrawal effects. Drug efficacy was assessed quantitatively by calculating the number of PVCs per day, and qualitatively by using the Lown grading system. There were 3 dropouts. Of the 17 patients who completed the trial, 10 (59%) showed a reduction of PVCs of at least 65%, and in 9 (53%) this occurred on a dosage of 400 mg/d. Elimination of grade 4A or 4B arrhythmia was observed in 6 (67%) of 9 patients. Although most patients were normotensive before entry into trial, none developed a drop in systolic blood pressure to 100 mmHg or less. The heart rate decreased slightly but significant bradycardia was not noted. Acebutolol did not adversely affect left ventricular function as assessed echocardiographically. We conclude that acebutolol is safe and effective for the treatment of PVCs And in most patients may be administered in a dosage of 200 mg twice daily.