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Search Results: 1 - 10 of 2012 matches for " Harald Pasch "
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Synthesis of Oligomers of 12-Acryloyloxydodecanoic Acid via Reversible Addition Fragmentation Transfer (RAFT) Polymerisation
Lilian Tichagwa,Ron D. Sanderson,Harald Pasch
International Journal of Chemistry , 2009, DOI: 10.5539/ijc.v1n2p20
Abstract: A long chain fatty acid carrying an acryloyl functionality, 12-acryloyloxydodecanoic acid (12-ADA), was prepared from 11-hydroxydodecanoic acid and acryloyl chloride and used as monomer in the synthesis of oligomers of 12-ADA via the RAFT controlled polymerisation process. Reversible Addition Fragmentation Transfer (RAFT) reagents were prepared and used to control the polymerisation process and produced an oligomeric product with few monomeric units instead of a high molecular weight polymer of 12-ADA. The transfer reagents were prepared from Grignard intermediates from a reaction of dithioacids with free radical initiators 2,2-azobisisobutyronitrile (AIBN) and 4,4-azobis(4-cyanopropanoic acid) (ACP). It was found that short-chain oligomers in the form of dimers and trimers characterized by Electrospray Mass Spectrometry, ESMS and Gel Permeation chromatography, GPC were the major products obtained when RAFT reagents had been used in the controlled polymerisation. As a control, polymerisation was carried out in the absence of RAFT reagents and high molecular-weight polymers were obtained. This confirmed the effectiveness of the prepared RAFT reagents as polymerisation controllers and provided a way for the synthesis of oligomers. Here, the preparation of oligomers of 12-ADA using AIBN-RAFT reagents is reported. The method is expected to provide one way of preparing oligomers of controlled chain length/molecular mass which also carry a carboxylic acid functional group at one end.
Automated Monitoring of the Establishment of the Adsorption Equilibrium: Adsorption of Polyethylene from 1,2,4-Trichlorobenzene onto a Zeolite at Temperature C
Tibor Macko,Robert Brüll,Christoph Brinkmann,Harald Pasch
Journal of Analytical Methods in Chemistry , 2009, DOI: 10.1155/2009/357026
Abstract: The automated procedure for the monitoring of the adsorption process in the solute-sorbent-solvent system has been elaborated. It uses commercially available instrument CRYSTAF model 200. The application of CRYSTAF enabled monitoring of adsorption of linear polyethylene with weight average molar masses of 2, 14, and 53 kg/mol from 1,2,4-trichlorobenzene onto zeolite SH-300 at temperature as high as 140°C. It is the authors' understanding that this is the first demonstration of an adsorption isotherms for polyethylene. The measurement with the CRYSTAF instrument reduces manual manipulations with dangerous solvents at high temperature and enables automated long-time monitoring of the concentration of the solute in an adsorption system.
Structure and Oligomers Distribution of Commercial Tara (Caesalpina spinosa) Hydrolysable Tannin
Samuele GIOVANDO,Antonio PIZZI,Harald PASCH,Naomi PRETORIUS
Pro Ligno , 2013,
Abstract: Solvent extracted commercial Tara tanninextract have been examined by Matrix Assisted LaserDesorption/Ionisation Time-of-Flight (MALDI-TOF)mass spectrometry and by High Pressure LiquidChromatography (HPLC). The Tara extract has beenfound to be composed of a series of oligomers ofpolygallic acid attached by an ester link to one quinicacid. They constitute the oligomers in higherproportion in the extract. Other polygallic chains linkedto one only or two repeating units such as caffeic acidand methylated quinic, methylated gallic andmethylated caffeic acids are also present. Negativeion mode MALDI-TOF showed that somecarbohydrate residues appear to still be present,linked to the polyphenolic material of the extract buttheir proportion is very low as would be expected of asolvent extracted tannin.
Beck, Rose Marie & Frank Wittmann (eds.) 2004. African Media Cultures – Transdisciplinary Perspectives. Cultures de médias en Afrique. Perspectives transdisciplinaires - Topics in African Studies, Vol. 2, K ln: K ppe Verlag, 320 pages, 2 b/w photos, 17 tables, 15 graphs, €34,80
Pasch, Helma
Afrikanistik Online , 2006,
Abstract:
Impacto da pesquisa laboratorial de trombofilia na preven o secundária e orienta o dos doentes com tromboembolismo venoso Impact of the laboratory screening on thrombophilia for the secondary prevention and management of patients with venous thromboembolism
Adilson Ferraz Pasch?a
Jornal Vascular Brasileiro , 2006, DOI: 10.1590/s1677-54492006000400016
Abstract:
Different typologies of workplace conflict and their connections with post traumatic embitterment disorder (PTED)  [PDF]
Harald Ege
Health (Health) , 2010, DOI: 10.4236/health.2010.23033
Abstract: Reported is an empirical study which shows that Post-Traumatic Embitterment Disorder (PTED) is the most appropriate psychological diagnosis for victims of workplace conflicts, particularly bullying. A group of 118 people all reporting conflict at work were evaluated with the LIPT questionnaire, the PTED self-rating scale and a guided psychological interview. 91.5% proved to be affected by a PTED, the slight majority males, aged between 31 and 40 years and subjected to bullying. The evidence suggests that some workplace conflict victims who are presently diagnosed and treated as depression or phobia can be in fact cases of PTED. The treatment may be adjusted and the PTED scale may be used as a screening in-strument similar to scales for anxiety and depressive disorders.
On a New Mechanism for Separating two Components in a Stationary Flow through Mesopores  [PDF]
Harald Morgner
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.25070
Abstract: When simulating the behavior of fluids in a stationary flow through mesopores we have observed a phenomenon that may prove useful in some cases as basis for separating fluid components. The scheme works at constant temperature which makes it energy efficient as are other schemes like (molecular) sieves or chromatography. Sieves rely on differences in molecular size and chromatography on different affinity of components to the solid material of the ‘packing’. The scheme presented here may sometimes complement the established techniques in that it is based on a different mechanism. The fluids to be separated can have the same molecular size and the same affinity to solid material they are in contact with. The only requirement for the scheme to work is that the miscibility behavior varies somewhat with pressure or density. From literature it is known that virtually any mixture reacts on strong variations of pressure. Even a mixture that behaves almost ideally at ambient pressure will show slight deviations from ideal miscibility when exposed to extreme pressure. The strong differences in pressure are not created by external means but by exploiting the spontaneous behavior of fluids in mesopores. If the experiment is designed correctly, strong pressure gradients show up in mesopores that are far beyond any gradient that could be established by technical means. Our simulations are carried out for situations where pressure inside the pores varies between a few hundred bar positive pressure and a few hundred bar negative pressure while the pressure in the gas phase outside the pores amounts to ca.170 mbar.
From Thaer and Thünen until Today: Past and Future of Agricultural Landscape Use in Germany  [PDF]
Harald Kaechele, Sunil Nautiyal
Natural Resources (NR) , 2010, DOI: 10.4236/nr.2010.12006
Abstract: This article intends to present the historical development of German agriculture sector in last two centuries and underlined the benefit of the advancement in agriculture sector to fulfil the growing food demand. At the same time the article discussed the ecological and socio-economic perspectives of rapid technological development of agriculture sector in Germany. This article would facilitate the debate on technological development in agriculture sector, which rapidly growing throughout the world, in view point of sustainable socio-ecological development.
Matrix Metalloproteinase MMP-9 Promotes K/BxN Serum Induced Arthritis in Mice  [PDF]
Narendiran Rajasekaran, Harald Illges
Open Journal of Rheumatology and Autoimmune Diseases (OJRA) , 2014, DOI: 10.4236/ojra.2014.41003
Abstract: Matrix metalloproteinases (MMPs) are matrix-degrading enzymes that are over-expressed in joints of rheumatoid arthritis (RA) patients. However, the contribution of specific MMPs for the development of arthritic joints is unknown. This study is aimed at studying the role of matrix metalloproteinase-9 (MMP-9) in mice, using the K/BxN serum-transfer model of RA. Arthritis was induced in Balb/c mice by injecting K/BxN serum. Development of arthritis was followed in these mice by measuring ankle thickness and clinical index score. MMP-9 expression in the joints of mice killed at various time points during the disease progression was determined by gelatin zymography using ankle lysates. We found that MMP-9 expression increased with the severity of arthritis. Importantly MMP-9 deficient mice injected with K/BxN serum showed a milder form of arthritis in comparison to the control C57BL/6 mice injected with K/BxN serum. We therefore conclude that MMP-9 promotes arthritis in mice.
The validation of a home food inventory
Jayne A Fulkerson, Melissa C Nelson, Leslie Lytle, Stacey Moe, Carrie Heitzler, Keryn E Pasch
International Journal of Behavioral Nutrition and Physical Activity , 2008, DOI: 10.1186/1479-5868-5-55
Abstract: A home food inventory (HFI) was developed and tested with two samples. Sample 1 included 51 adult participants and six trained research staff who independently completed the HFI in participants' homes. Sample 2 included 342 families in which parents completed the HFI and the Diet History Questionnaire (DHQ) and students completed three 24-hour dietary recall interviews. HFI items assessed 13 major food categories as well as two categories assessing ready-access to foods in the kitchen and the refrigerator. An obesogenic household food availability score was also created. To assess criterion validity, participants' and research staffs' assessment of home food availability were compared (staff = gold standard). Criterion validity was evaluated with kappa, sensitivity, and specificity. Construct validity was assessed with correlations of five HFI major food category scores with servings of the same foods and associated nutrients from the DHQ and dietary recalls.Kappa statistics for all 13 major food categories and the two ready-access categories ranged from 0.61 to 0.83, indicating substantial agreement. Sensitivity ranged from 0.69 to 0.89, and specificity ranged from 0.86 to 0.95. Spearman correlations between staff and participant major food category scores ranged from 0.71 to 0.97. Correlations between the HFI scores and food group servings and nutrients on the DHQ (parents) were all significant (p < .05) while about half of associations between the HFI and dietary recall interviews (adolescents) were significant (p < .05). The obesogenic home food availability score was significantly associated (p < .05) with energy intake of both parents and adolescents.This new home food inventory is valid, participant-friendly, and may be useful for community-based behavioral nutrition and obesity prevention research. The inventory builds on previous measures by including a wide range of healthful and less healthful foods rather than foods targeted for a specific intervention.A
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