Multivalent presentation of mannose on hyperbranched polyglycerol and their interaction with concanavalin A lectin

We describe the synthesis of multivalent mannose derivatives by using hyperbranched polyglycerols (hPG) as a scaffold with different linker structures. Grafting of protected mannose (Man) units is achieved by using Cu(I) -catalyzed Huisgen click chemistry with either an anomeric azide or propargyl ether onto complementarily functionalized alkyne or azido polymer surfaces. NMR spectroscopy, dynamic light scattering (DLS), IR spectroscopy, size-exclusion chromatography (SEC), and elemental analysis have been used to characterize the hPG-Man compounds. The surface availability and bioactivity of Man-modified polymers were evaluated by using a competitive surface plasmon resonance (SPR)-based binding assay by interactions of the glycopolymers with concanavalin A (Con A), a lectin that binds mannose containing molecules. The results indicated that the novel glycoarchitectures presented in this work are efficient inhibitors of Con A-mannose recognition and resulted in inhibitor concentrations (mean IC(50)) from the micro- to the nanomolar range, whereas the corresponding monovalent mannoside (methyl-Man) requires millimolar concentrations. The results provide an interesting structure-activity relationship for libraries of materials that differ in the linkage of the sugar moiety presented on a biocompatible polyglycerol scaffold.     

Die dritte Welle – Die Biotechnologie erobert die Chemieindustrie

The Third Wave – Biotechnology Conquers the Chemical Industry Biotechnology is not longer limited to pharmaceutical industry and agriculture. Also the chemical industry can benefit from biotechnological production processes. Without an optimal environment in terms of acceptance and legislation, the potential of biotechnology, however, will not be used to its full extent. If Germany will not be able to provide such conditions competitors in other areas of the world will be more successful.     

Challenges and Opportunities to Enhance Flexibility in Design and Operation of Chemical Processes

Flexibility receives increased interest in chemical engineering and is discussed as one measure to deal with upcoming challenges for the chemical industry. In this paper, different types of flexibility are presented, and flexibility needs are illustrated. The focus is on the evaluation and classification of available solutions to enhance flexibility. Solutions and future challenges across all length scales of chemical engineering are discussed: from tailored catalyst properties to decoupling of processes by means of storage.     

Comparison of the Operating Range of a Wetted-Wall Column with a Packed Column for Distillation

In this paper, a newly designed distillation column consisting of a wetted wall with a rectangular cross section is analyzed and compared with a conventional packed column with regard to the operating range of both apparatuses. As expected, the pressure drop is considerably lower in the wetted-wall column and, therefore, it offers a higher range of operation. However, in the wetted-wall column, the separation efficiency decreases rapidly with increasing F factors. This effect can be overcome by the serial connection of two wetted-wall columns.     

Job strain and risk indicators for cardiovascular disease in young female nurses.

This study examined the possible effects of job demands, decision latitude, and job-related social support on risk indicators for cardiovascular disease (CVD) in 165 female nurses. Job strain was measured with the Job Content Questionnaire; CVD risk was measured with insulin, total cholesterol, triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), fibrinogen, tissue-type plasminogen activator (tPA) antigen, tPA activity, plasminogen activator inhibitor-1 antigen, and blood pressure. Multivariate analysis of covariance and regression analyses revealed no effects of either job strain or social support on these risk indicators. All risk indicators deteriorated with age and body mass index. Oral contraceptive use improved fibrinolytic potential and increased HDL-C but had adverse effects on TG levels. Results suggest that in healthy young women job strain is not associated with an unfavorable metabolic or fibrinolytic risk profile. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypergeometric Summation Algorithms for High-order Finite Elements

High-order finite elements are usually defined by means of certain orthogonal polynomials. The performance of iterative solution methods depends on the condition number of the system matrix, which itself depends on the chosen basis functions. The goal is now to design basis functions minimizing the condition number, and which can be computed efficiently. In this paper, we demonstrate the application of recently developed computer algebra algorithms for hypergeometric summation to derive cheap recurrence relations allowing a simple implementation for fast basis function evaluation.     

Predictive parameters of biologic behavior of early stage nonseminomatous testicular germ cell tumors

BACKGROUND: Thirty percent of patients presenting with clinical stage A nonseminomatous testicular germ cell tumors in fact have pathologic stage B disease. This pilot study was performed to determine whether DNA content and cell cycle analysis by flow cytometry and single-cell cytophotometry can improve clinical staging in these patients. METHODS: The orchiectomy specimens of 102 patients with clinical stage A disease were analyzed retrospectively using histopathologic classification, flow cytometry, and single-cell cytophotometry. All patients had undergone retroperitoneal lymph node dissection. RESULTS: The multivariate analysis in this group of patients resulted in the following model: If the primary tumor consisted of 100% embryonal carcinoma, the patient was classified as high risk for retroperitoneal metastasis. If the patient was found to have less than 100% embryonal carcinoma in the primary tumor, the percent of aneuploid tumor cells in S-phase as identified by flow cytometry was most predictive for pathologic stage. Using this approach, 91% of all patients with pathologic stage B, and 77% of the patients with pathologic stage A were correctly classified; test efficiency was 82%. CONCLUSIONS: These results demonstrate an improvement in clinical staging in this group of patients. This paradigm, developed from retrospective analysis, will be tested prospectively in consecutive patients to determine if it is clinically useful.