bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydroraffinationskatalysatoren in der Erdölverarbeitung – Stand und Perspektiven
Authors: Reschetilowski W. 
Published: May 2007

AbstractDie Hydroraffination (Hydrotreating) hat sich in den vergangenen Jahrzehnten zu einem der wichtigsten katalytischen Verfahren in der Erdölverarbeitung entwickelt. Insbesondere ist die Herstellung schwefelfreier Kraftstoffe von großer Bedeutung für den Umweltschutz, da bei ihrer Verbrennung ein verkehrsbedingtes Auftreten von SO2‐Emissionen und eine schnelle Desaktivierung von Abgaskatalysatoren ausgeschlossen sind. In diesem Beitrag werden die wichtigsten Vertreter der Hydroraffinationskatalysatoren – von den Herstellungsmethoden über die Struktur und die Oberflächenchemie bis zum Wirkungsmechanismus – beschrieben. Ein besonderes Augenmerk wird auf die klassischen sulfidischen CoMo/Al2O3‐ sowie NiMo/Al2O3‐Katalysatoren zur katalytischen Hydrodesulfurierung (HDS) gerichtet, aber auch neue Katalysatorentwicklungen auf diesem Gebiet werden kurz beleuchtet.
Mikrostrukturreaktoren für die heterogene Katalyse
Authors: Klemm E. , Döring H. , Geißelmann A. , Schirrmeister S. 
Published: May 2007

AbstractSeit Anfang der 90er Jahre des letzten Jahrhunderts ist eine große Vielzahl heterogen katalysierter Reaktionen, vor allem Gasphasenreaktionen, in Labor‐Mikrostrukturreaktoren durchgeführt und deren prinzipielle Eignung und Potenziale in der heterogenen Katalyse nachgewiesen worden. Seit Beginn dieses Jahrhunderts steht die Übertragung der Mikrotechnologie vom Labor‐ in den Produktionsmaßstab im Vordergrund. Diese Übersicht widmet sich daher insbesondere den technischen Konzepten und den wirtschaftlichen Aspekten. Heterogen katalysierte Gasphasen‐ und Flüssigphasenprozesse werden dabei getrennt voneinander diskutiert. Die Präparation von Wandkatalysatoren ist in beiden Fällen eine entscheidende Schlüsseltechnologie, der ein eigener Abschnitt gewidmet wird. Abschließend erfolgt eine Bewertung des Entwicklungsstands.
Die oberflächenchemische Modifikation von Kohlenstoff‐Nanoröhren für die Anwendung in der heterogenen Katalyse
Authors: Xia W. , Naumann d'Alnoncourt R. , Muhler M. 
Published: May 2007

AbstractAufgrund ihrer einzigartigen Strukturen und Eigenschaften sind Kohlenstoff‐Nanoröhren (carbon nanotubes, CNTs) für die heterogene Katalyse von großem Interesse. Um Kohlenstoff‐Nanoröhren als Katalysator oder Trägermaterial einsetzen zu können, ist es nötig, deren Oberfläche und Morphologie geeignet zu verändern. In diesem Beitrag wird die Modifizierung von Kohlenstoff‐Fasern verschiedener Größe beschrieben, ausgehend von Nanoröhren bis hin zu Mikrofasern. Es wird die Rolle von Oberflächengruppen bei der Präparation von geträgerten Palladiumkatalysatoren durch chemische Gasphasenabscheidung erläutert, und es wird gezeigt, wie sich durch Verzweigungen die spezifische Oberfläche von Kohlenstoff‐Nanoröhren erhöhen lässt. Die Entwicklung von hierarchisch strukturierten Kohlenstoff‐Nanoröhren‐Kompositmaterialen wird detailliert beschrieben.
Heterogene Katalyse in überkritischen Medien – 1. Kohlendioxid
Authors: Kruse A. , Vogel H. 
Published: May 2007

AbstractÜberkritische Fluide haben in den letzten Jahren großes Interesse als Reaktionsmedien gefunden. Die Eigenschaften von überkritischen Fluiden liegen zwischen denen von Gasen und Flüssigkeiten. Die Dichten sind zwar geringer als in der flüssigen Phase, aber deutlich höher als in der Gasphase. Dies macht überkritische Fluide zu hervorragenden Lösungsmitteln für eine Vielzahl von Stoffen. Das gute Lösungsvermögen besteht nur im bzw. nahe dem überkritischen Bereich; Reaktionsprodukte lassen sich beispielsweise einfach durch Verminderung von Temperatur und Druck abtrennen. Dies kann zur Prozessintensivierung genutzt werden, da aufwendige Trennprozesse wie Destillationen vermieden werden.
Paddle‐Wheel Zinc Carboxylate Clusters as Building Units for Metal‐Organic Frameworks
Authors: Vagin S. , Ott A. K. , Rieger B. 
Published: May 2007

AbstractGrowth of interest to a field of materials chemistry such as the metal‐organic frameworks (MOFs) demands the comprehensible surveying of new results, and the reviews systematizing and highlighting one or another trend in the MOF research appear periodically. Structural peculiarities of coordination polymers constructed by zinc paddle‐wheel clusters and the investigation of their microporosity are reviewed in detail to emphasize those features of the materials, which are interesting both for the pure and applied chemists.
Malaria Chemotherapeutics Part I: History of Antimalarial Drug Development, Currently Used Therapeutics, and Drugs in Clinical Development
Authors: Schlitzer Martin 
Published: May 2007

AbstractSince ancient times, humankind has had to struggle against the persistent onslaught of pathogenic microorganisms. Nowadays, malaria is still the most important infectious disease worldwide. Considerable success in gaining control over malaria was achieved in the 1950s and 60s through landscaping measures, vector control with the insecticide DDT, and the widespread administration of chloroquine, the most important antimalarial agent ever. In the late 1960s, the final victory over malaria was believed to be within reach. However, the parasites could not be eradicated because they developed resistance against the most widely used and affordable drugs of that time. Today, cases of malaria infections are on the rise and have reached record numbers. This review gives a short description of the malaria disease, briefly addresses the history of antimalarial drug development, and focuses on drugs currently available for malaria therapy. The present knowledge regarding their mode of action and the mechanisms of resistance are explained, as are the attempts made by numerous research groups to overcome the resistance problem within classes of existing drugs and in some novel classes. Finally, this review covers all classes of antimalarials for which at least one drug candidate is in clinical development. Antimalarial agents that are solely in early development stages will be addressed in a separate review.
Paclitaxel And Docetaxel Resistance: Molecular Mechanisms and Development of New Generation Taxanes
Authors: Galletti Elena , Magnani Matteo , Renzulli Michela L. , Botta Maurizio 
Published: May 2007

AbstractTaxanes represent one of the most promising classes of anticancer agents. Unfortunately, their clinical success has been limited by the insurgence of cellular resistance, mainly mediated by the expression of the MDR phenotype or by microtubule alterations. However, the remarkable relevance of paclitaxel and docetaxel in clinical oncology stimulated intensive efforts in the last decade to identify new derivatives endowed with improved activities towards resistant tumor cells, resulting in a huge number of novel natural and synthetic taxanes. Among them, several structurally different derivatives were found to exhibit a promising behavior against the MDR phenotype in terms of either MDR inhibiting properties, or enhanced cytotoxicity compared to parental drugs, or both. On the other hand, only in more recent years have the first taxanes retaining activity against resistant cancer cells bearing alterations of the tubulin/microtubule system emerged. This review describes the main molecular mechanisms of resistance to paclitaxel and docetaxel identified so far, focusing on the advances achieved in the development of new taxanes potentially useful for the treatment of resistant tumors.
Recent Developments in Ghrelin Receptor Ligands
Authors: Moulin Aline , Ryan Joanne , Martinez Jean , Fehrentz Jean‐Alain 
Published: May 2007

AbstractThe 28‐amino acid peptide ghrelin is a neuroendocrine hormone synthesized primarily in the stomach. It stimulates growth hormone secretion and appetite, thus promoting food intake and body‐weight gain. The pharmacological properties of this peptide are mediated by the growth hormone secretagogue receptor type 1a (GHS‐R1a). Given its wide spectrum of biological activities, it is evident that the discovery of ghrelin and its receptor has opened up many perspectives in the fields of neuroendocrine and metabolic research and has had an influence on such fields of internal medicine as gastroenterology, oncology, and cardiology. It is therefore increasingly likely that synthetic, peptidyl, and nonpeptidyl GHS‐R1a ligands, acting as agonists, partial agonists, antagonists, or inverse agonists, could have both clinical and therapeutic potential. This review summarizes the various types of GHS‐R1a ligands that have been described in the literature and discusses the recent progress made in this research area.
Pentostatin, cyclophosphamide, and rituximab regimen in older patients with chronic lymphocytic leukemia
Authors: Shanafelt Tait D. , Lin Thomas , Geyer Susan M. , Zent Clive S. , Leung Nelson , Kabat Brian , Bowen Deborah , Grever Michael R. , Byrd John C. , Kay Neil E. 
Published: May 2007

AbstractBACKGROUND.The prevalence of chronic lymphocytic leukemia (CLL) increases with age. Although chemoimmunotherapy (CIT) has dramatically improved response rates in patients with CLL, some CIT regimens are not well tolerated by many patients ≥70 years of age.METHODS.Sixty‐four previously untreated patients with CLL and serum creatinine <1.5 times the upper limit of normal who met National Cancer Institute (NCI) 96‐WG criteria for treatment received pentostatin (2 mg/m2), cyclophosphamide (600 mg/m2), and rituximab (375 mg/m2). The authors measured performance status at study entry and used age, weight, and baseline creatinine to calculate creatinine clearance (CrCl).RESULTS.Eighteen of 64 (28%) patients were ages ≥70 years. Although individuals ages ≥70 years were more likely to have delayed treatment cycles (28% vs 7%; P = .03), there were no significant differences in the number of cycles administered, need for dose reductions, or grade 3–4 hematologic, infectious, or other toxicities. No significant differences in overall response rate, complete response rate, or progression‐free survival were observed by age. Twenty‐five (39%) patients had a CrCl < 70 mL/min (range, 34–67). Although individuals with CrCl < 70 were more likely to require dose reduction (24% vs 5%; P = .05), there were no significant differences in the number of cycles administered or grade 3–4 hematologic, infectious, or other toxicities. No significant difference in overall response rate, complete response rate, or progression‐free survival were observed between patients with CrCl ≥ 70 mL/min and those with CrCl < 70 mL/min.CONCLUSIONS.In this clinical trial, the PCR regimen was well tolerated by older patients and individuals with CrCl ≤ 70. The efficacy of PCR was not significantly affected by age or renal function. These findings suggest PCR may be a good therapeutic option for older patients and those with modestly decreased renal function. Cancer 2007; 109:2291–8. © 2007 American Cancer Society.
Prostate cancer‐specific mortality after radical prostatectomy or external beam radiation therapy in men with 1 or more high‐risk factors
Authors: D'Amico Anthony V. , Chen Ming‐Hui , Catalona William J. , Sun Leon , Roehl Kimberly A. , Moul Judd W. 
Published: May 2007

AbstractBACKGROUND.Estimates of prostate cancer‐specific mortality (PCSM) were determined after radical prostatectomy (RP) or radiation therapy (RT) in men with ≥1 high‐risk factors.METHODS.The study cohort comprised 948 men who underwent RP (N = 660) or RT (N = 288) for localized prostate cancer between 1988 and 2004 and had at least 1 of the following high‐risk factors: a prostate‐specific antigen (PSA) velocity >2 ng/mL/year during the year before diagnosis, a biopsy Gleason score of ≥7, a PSA level of ≥10 ng/mL, or clinical category T2b or high disease. Grays regression was used to evaluate whether the number and type of high‐risk factors were associated with time to PCSM.RESULTS.Multiple determinants of high risk were found to be significantly associated with a shorter time to PCSM after RP (P < .001) or RT (P ≤ .001). The solitary presence of a PSA velocity >2 ng/mL/year was associated with an increased risk of PCSM after RP (hazards ratio [HR] of 7.3; 95% confidence interval [95% CI], 1.0–59 [P = .05]) or RT (HR of 12.1; 95% CI, 1.4–105 [P = .02]) when compared with men with any other single high‐risk factor.CONCLUSIONS.Men with a PSA velocity >2 ng/mL/year had a significantly higher risk of PCSM compared with men who had any other single high‐risk factor. These men should be considered for randomized trials evaluating the impact on PCSM from adding systemic agents to standards of care for men with high‐risk PC. Cancer 2007. © 2007 American Cancer Society.
Molecularly targeted therapy for malignant glioma
Authors: Sathornsumetee Sith , Reardon David A. , Desjardins Annick , Quinn Jennifer A. , Vredenburgh James J. , Rich Jeremy N. 
Published: May 2007

AbstractMalignant gliomas are relatively uncommon but lethal cancers. Despite recent research efforts in cancer therapy, the prognosis of patients with malignant gliomas has remained dismal. Understanding the molecular pathogenesis of glioma may lead to a rational development of new therapies. Despite the genetic heterogeneity of malignant gliomas, common aberrations in the signaling elements of the growth and survival pathways are found. New treatments have emerged to target molecules in these signaling pathways with the goal to increase specific efficacy and minimize toxicity. Monoclonal antibodies and low molecular‐weight kinase inhibitors are the most common classes of agents in targeted cancer treatment. Most clinical trials of these agents as monotherapies have failed to demonstrate survival benefit in unselected malignant glioma patient populations. Several mechanisms of treatment failure have been demonstrated. In response, multitargeted kinase inhibitors and combinations of single‐targeted kinase inhibitors have been developed to overcome therapeutic resistance. In addition, multimodality combinations of targeted agents with radiation, chemotherapy, or immunotherapy/vaccines may enhance treatment efficacy. Future development of these agents will require advances in discovery and validation of new molecular targets, improvement of therapeutic delivery, and identification of correlative biomarkers. Novel clinical trial designs and endpoints may increase the efficiency of new drug evaluation. In this review, the authors discussed the current understanding of molecular pathogenesis and the development of molecularly targeted therapies in malignant glioma. Cancer 2007. © 2007 American Cancer Society.
Characteristics of pediatric chemotherapy medication errors in a national error reporting database
Authors: Rinke Michael L. , Shore Andrew D. , Morlock Laura , Hicks Rodney W. , Miller Marlene R. 
Published: May 2007

AbstractBACKGROUND.Little is known regarding chemotherapy medication errors in pediatrics despite studies suggesting high rates of overall pediatric medication errors. In this study, the authors examined patterns in pediatric chemotherapy errors.METHODS.The authors queried the United States Pharmacopeia MEDMARX database, a national, voluntary, Internet‐accessible error reporting system, for all error reports from 1999 through 2004 that involved chemotherapy medications and patients aged <18 years.RESULTS.Of the 310 pediatric chemotherapy error reports, 85% reached the patient, and 15.6% required additional patient monitoring or therapeutic intervention. Forty‐eight percent of errors originated in the administering phase of medication delivery, and 30% originated in the drug‐dispensing phase. Of the 387 medications cited, 39.5% were antimetabolites, 14.0% were alkylating agents, 9.3% were anthracyclines, and 9.3% were topoisomerase inhibitors. The most commonly involved chemotherapeutic agents were methotrexate (15.3%), cytarabine (12.1%), and etoposide (8.3%). The most common error types were improper dose/quantity (22.9% of 327 cited error types), wrong time (22.6%), omission error (14.1%), and wrong administration technique/wrong route (12.2%). The most common error causes were performance deficit (41.3% of 547 cited error causes), equipment and medication delivery devices (12.4%), communication (8.8%), knowledge deficit (6.8%), and written order errors (5.5%). Four of the 5 most serious errors occurred at community hospitals.CONCLUSIONS.Pediatric chemotherapy errors often reached the patient, potentially were harmful, and differed in quality between outpatient and inpatient areas. This study indicated which chemotherapeutic agents most often were involved in errors and that administering errors were common. Investigation is needed regarding targeted medication administration safeguards for these high‐risk medications. Cancer 2007. © 2007 American Cancer Society.
Clinicopathologic significance of BRAF V600E mutation in papillary carcinomas of the thyroid
Authors: Lee Ju‐Han , Lee Eung‐Seok , Kim Young‐Sik 
Published: May 2007

AbstractBACKGROUND.Numerous studies have investigated the clinical significance of BRAF mutation in papillary thyroid carcinoma (PTC). However, there have been conflicting data on the usefulness of BRAF mutation as a prognostic marker of PTC. To address this controversy, the frequency of the BRAF mutation and the associations between BRAF mutation and clinicopathologic parameters in PTC were evaluated by meta‐analysis.METHODS.The relevant published studies were reviewed according to the defined selection criteria. The effect sizes of outcome parameters were estimated by odds ratio or weighted mean difference.RESULTS.The current meta‐analysis included 12 studies with a total of 1168 patients. The frequency of the BRAF mutation was 49%. The BRAF mutation was associated with histologic subtype, the presence of extrathyroidal extension, and higher clinical stage, but not with age, sex, race, or tumor size.CONCLUSIONS.The effect of the BRAF mutation on the poor prognosis of PTC patients was evident from the current meta‐analysis. The detection of the BRAF mutation may be used as an important prognostic marker of patients with PTC. Cancer 2007. © 2007 American Cancer Society.
Timing of biochemical failure and distant metastatic disease for low‐, intermediate‐, and high‐risk prostate cancer after radiotherapy
Authors: Morgan Peter B. , Hanlon Alexandra L. , Horwitz Eric M. , Buyyounouski Mark K. , Uzzo Robert G. , Pollack Alan 
Published: May 2007

AbstractBACKGROUND.The relation of prostate cancer risk‐group stratification and the timing of biochemical failure (BF) and distant metastasis (DM) is not well defined. The authors hypothesized that early failures due to subclinical micrometastasis at presentation could be differentiated from late failures due to local persistence.METHODS.A total of 1833 men with clinically localized prostate cancer treated with 3D‐conformal radiotherapy with or without short‐term androgen deprivation were retrospectively analyzed. By using American Society for Therapeutic Radiology and Oncology (ASTRO) and Phoenix (Nadir+2) definitions (developed at the ASTRO‐RTOG [Radiation Therapy Oncology Group] consensus meeting, Phoenix, Arizona, January 21, 2005), the interval hazard rates of BF and DM were determined for men with low‐risk, intermediate‐risk, and high‐risk disease.RESULTS.Median follow‐up was 67 months. Multivariate analysis showed that increasing risk group was independently associated with higher ASTRO BF (P < .0001) and Nadir+2 BF (P < .0001). The preponderance (87%) of ASTRO BF occurred ≤4 years after radiotherapy, whereas Nadir+2 BF was more evenly spread over Years 1–12, with 43% at >4 years. The hazard of Nadir+2 BF persisted in Years 8–12 in all risk groups. The interval hazard function for DM appeared to be biphasic (early peak followed by a drop and late increase) for intermediate‐risk and high‐risk patients, but no distinct early wave was evident for low‐risk patients.CONCLUSIONS.Because of backdating, ASTRO BF underestimates late BF. Local persistence of disease is suggested by delayed Nadir+2 BF and subsequent late DM in every risk group. The paucity of early DM among those with low‐risk tumors supports the hypothesis that occult micrometastases contributed to the early wave. Cancer 2007. © 2007 American Cancer Society.
Promoter methylation as a common mechanism for inactivating E‐cadherin in human salivary gland adenoid cystic carcinoma
Authors: Zhang Chun‐Ye , Mao Li , Li Lei , Tian Zhen , Zhou Xiao‐Jian , Zhang Zhi‐Yuan , Li Jiang 
Published: May 2007

AbstractBACKGROUND.The role of promoter methylation in the inactivation of E‐cadherin (E‐cad) in salivary gland adenoid cystic carcinoma (ACC) is unknown. The objective of this study was to determine the role and potential clinical implications of promoter methylation of E‐cad in salivary gland ACC.METHODS.The promoter methylation status of E‐cad was determined by using methylation‐specific polymerase chain reaction (PCR) analysis in 60 primary salivary gland ACC tissues and 3 ACC cell lines. The level of E‐cad protein expression was determined by immunohistochemical analysis of each tumor. E‐cad protein and messenger RNA (mRNA) expression levels were examined by immunohistochemical analysis and reverse transcriptase‐PCR in 3 ACC cell lines. Associations between molecular alterations and patients' clinicopathologic characteristics were analyzed statistically. E‐cad mRNA expression was examined in a 5‐azacytidine‐treated ACC‐2 cell line.RESULTS.Promoter methylation of E‐cad was detected in 34 of 60 tumors (57%). Of those 34 tumors, 18 tumors (53%) showed no E‐cad protein expression, whereas only 5 of the remaining 26 tumors (19%) without E‐cad promoter methylation showed no E‐cad protein expression (P = .01). Tumors that had E‐cad promoter methylation had a significantly higher histologic grade (P = .01) and more perineural invasion (P = .02) compared with tumors that did not have methylation. All 3 ACC cell lines exhibited E‐cad promoter methylation and a lack of E‐cad mRNA and protein expression, whereas 5‐azacytidine restoredE‐cad mRNA expression in the ACC‐2 cell line.CONCLUSIONS.E‐cad frequently is inactivated in salivary gland ACC through promoter methylation, and E‐cad promoter methylation may play a role in tumor cell differentiation and perineural invasion. Cancer 2007. © 2007 American Cancer Society.