Search Results - (Author, Cooperation:A. Guenther)

2018-12-11

American Physical Society (APS)

1098-0121

1095-3795

Physics

Magnetism

2016-04-12

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Aerosols/chemistry ; Atlantic Ocean ; Atmosphere/*chemistry ; Nitrates/analysis/chemistry ; Nitric Acid/chemistry ; Nitrogen/*analysis/*chemistry ; Nitrogen Oxides/*analysis/*chemistry ; Nitrous Acid/analysis/chemistry ; North Carolina ; Oxidants/chemistry ; Photolysis ; Seawater/*chemistry ; South Carolina

0263-6484

Gout ; purine nucleotide interconversion ; allopurinol ; xanthine oxidase ; CTP synthetase ; Chemistry ; Biochemistry and Biotechnology

Wiley InterScience Backfile Collection 1832-2000

Biology

Medicine

The synthesis of uric acid from purine bases, nucleosides and nucleotides has been measured in reaction mixtures containing rat liver supernatant and each one of the following compounds at 1 mM concentration (except xanthine, 0·5 mM and guanosine and guanine, 0·1 mM). The rates of the reaction, expressed as nanomoles of uric acid synthesized g-1 of wet liver min-1 were: ATP, 10; ADP, 37; AMP, 62; adenosine, 108; adenine 6; adenylo-succinate, 9; IMP 32; inosine, 112; hypoxanthine, 50; GTP, 19; GDP, 19; GMP, 27; guanosine, 34; guanine, 72; XMP, 10; xanthosine, 24; xanthine, 144. These figures divided by 55 correspond to nanomoles of uric acid synthesized min-1 per mg-1 of protein. The rate of synthesis of uric acid obtained with each one of those compounds at 0·1 and 0·05 mM concentrations was also determined. ATP (1 nM) strongly inhibited uric acid synthesis from 0·05 mM AMP (91 per cent) and from 0·05 mM ADP (88 per cent), but not from adenosine. CTP or UTP (1 mM) also inhibited (by more than 90 per cent) the synthesis of uric acid from 0·05 mM AMP. Xanthine oxidase was inhibited by concentrations of hypoxanthine higher than 0·012 mM. The results favour the view that the level of uric acid in plasma may be an index of the energetic state of the organism. Allopurinol, besides inhibiting uric acid synthesis, reduced the rate of degradation of AMP. The ability of crude extracts to catabolize purine nucleotides to uric acid is an important factor to be considered when some enzymes related to purine nucleotide metabolism, particularly CTP synthase, are measured in crude liver extracts.

4 Ill.

Electronic Resource

0263-6484

Artemia ; purine nucleotide interconversion ; purine nucleosides ; adenosine ; guanosine ; inosine ; xanthosine ; diet ; mycophenolic acid ; Chemistry ; Biochemistry and Biotechnology

Wiley InterScience Backfile Collection 1832-2000

Biology

Medicine

Artemia uses the stored diguanosine tetraphosphate as a source of adenine and guanine nucleotides during development from the encysted gastrula to the free swimming larva. Further development of the larvae depends on a dietary source of purine rings. We have investigated the growth of Artemia in axenic cultures supplemented with 0·6 mg ml-1 of adenosine, guanosine, inosine or xanthosine. The total protein and soluble nucleotide content of Artemia grown in the presence of adenosine, guanosine or inosine was very similar, around (2 A260 units and 500 mg protein) and (4 A260 units and 1000 mg protein) after 4 and 6 days of postlarval development, respectively. The nucleotide pattern of those extracts subjected to HPLC were almost identical, the major peaks corresponding to ATP, ADP and AMP. Other nucleotides, not well characterized, were also present in those extracts. Mycophenolic acid (10 μg ml-1) inhibited the growth of Artemia (as measured by their protein and soluble nucleotide content) in the presence of adenosine and inosine as the purine source, and had no appreciable effect in the presence of guanosine. A quantitative analysis of the chromatographic peaks obtained from Artemia grown in the presence of any of the three nucleosides ± mycophenolic acid showed that the effect of the antibiotic on each one of the chromatographic peaks was very similar, suggesting that Artemia, and probably other organisms as well, tend to maintain a balance between all nucleotides and to adjust the overall level to the limiting step(s) in their rates of synthesis/interconversion. Xanthosine was not able to support the development of Artemia.

3 Ill.

Electronic Resource

article

2003

Erinnerung ; Deutschunterricht ; Gegenwartsliteratur ; Lektüre ; Literatur ; Antisemitismus ; Mitgutsch, Waltraud Anna ; Österreich

Informationen zur Deutschdidaktik, Bd. 27 (2003) H. 1, S. 97-100, 0721-9954

German

Literaturangaben

article

2003

Sachinformation ; Gestein ; Archäometrie ; Bestimmung ; Naturwissenschaften ; Lumineszenz ; Physik ; Archäologie ; Alter ; Verfahren

Praxis der Naturwissenschaften - Physik in der Schule, Bd. 52 (2003) H. 4, S. 160-166, 0177-8374

1617-5689

German

Internetadressen

article

2002

Sachinformation ; Chemie ; Magnesium ; Medizin ; Naturwissenschaften ; Werkstoff ; Anwendung ; Material

Praxis der Naturwissenschaften - Chemie in der Schule, Bd. 51 (2002) H. 4, S. 20-24, 0177-9516

1617-5638

German

Tabellen

article

2003

Sachinformation ; Bestimmung ; Naturwissenschaften ; Physik ; Archäologie ; Alter ; Verfahren

Biologie in unserer Zeit, Bd. 33 (2003) H. 5, S. 302-308, 0045-205X

German

book

1985

Schulverwaltung ; Geschichte (Histor) ; Hochschulschrift ; Baden

German

Bonn, Univ., Diss., 1983.

article

1989

Sachinformation ; Gestein ; Erdgeschichte ; Geochronologie ; Geowissenschaften ; Paläogeografie ; Physische Geografie ; Datierungsmethode ; Messverfahren ; Grafische Darstellung

Geographische Rundschau, Bd. 41 (1989) H. 9, S. 507-512, 0016-7460

German

article

1992

Methode ; Gestein ; Sedimentation ; Datierungsmethode ; Naturwissenschaften ; Radiolumineszenz ; Lumineszenz ; Physik ; Radiometrie ; Eiszeit ; Alter ; Datierung ; Verfahren

Spektrum der Wissenschaft, (1992) H. 4, S. 40-48, 0170-2971

German

Literaturangaben

article

2012

Liebe ; Deutschunterricht ; Gegenwartsliteratur ; Liebesgeschichte ; Romantik ; Novalis ; Schlegel, Friedrich von ; Deutschland

Deutschmagazin, Bd. 9 (2012) H. 6, S. 18-21, 1613-0693

German

book

1994

Medienarbeit ; Medienerziehung ; Medienpädagogik ; Außerschulische Jugendbildung ; Jugendarbeit ; Verzeichnis ; Institution ; Berlin

German

Register

2018-04-12

American Association for the Advancement of Science (AAAS)

2375-2548

Natural Sciences in General

2018-06-22

American Physical Society (APS)

1050-2947

1094-1622

Physics

Quantum optics, physics of lasers, nonlinear optics, classical optics

1365-2044

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Erythrocyte sedimentation rates from 40 suspensions of packed red blood cells in modified fluid gelatin, 4% albumin solution, 6% hydroxyethyl starch and normal saline were measured at room temperature using Westergren's method. The erythrocyte sedimentation rate was extremely high in gelatin and this increase was significant after 10–60 min when compared with the other fluids. Erythrocyte sedimentation rates in albumin, hydroxyethyl starch and normal saline were low and there were no differences between these fluids [erythrocyte sedimentation after 60 min, median (interquartile range): gelatin 128 (111.2–130.0) mm, albumin 2 (1.5–2.0) mm, hydroxyethyl starch 1.5 (1.0–1.6) mm, normal saline 2 (1.9–2.5) mm, p 〈 0.0001]. The addition of twice the volume of modified fluid gelatin to a volume of red blood cells leads to rapid acceleration of the erythrocyte sedimentation rate. This is caused by increased erythrocyte aggregation, and in clinical practice this effect may be useful for the haemoconcentration of diluted blood from cardiopulmonary bypass circuits or cell-saver autotransfusion in paediatric surgery.

Electronic Resource

1365-3121

Blackwell Publishing Journal Backfiles 1879-2005

Geosciences

Tectonomagmatic similarities between the modern Chilean flat-slab region and pre-Neogene magmatic episodes suggest that they represent analogues to flat subduction. Evolutionary patterns in each magmatic suite include (i) increasing La/Yb ratios and Sr-and Nd-isotopic enrichment through time, (ii) eastward-migration of magmatism after periods of transpressional/transtensional intra-arc deformation, and (iii) subsequent termination and virtual absence of main-arc activity for 5–10 Myr. These patterns may reflect slab shallowing followed by flat subduction and thickening of the overlying crust. If repeated, they require interchanging episodes of slab steepening. Increasing convergence rates force slab kinking and eventual failure of the oversteepened slab, followed by rebound of the slab tip (owing to lack of further slab pull), flat subduction and termination of subduction-related magmatism. Rapid subduction leads to shallow overriding of the detached slab fragment. Eclogitization of the gradually steepening slab tip at depth and subsequent slab pull permits asthenospheric corner flow and subduction-related magmatism.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] This event occurred at approximately 11 a.m. in the entrance hall of the Plockenhaus, a restaurant below the Plockenpass in the Carnic Alps (Austria). Students from a field trip of the Geology Department of the Universitat Heidelberg were staying inside this restaurant because of a thunderstorm ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] I AM indebted to Dr. John Murray for drawing my attention to an error in the address which I had the honour of delivering before the Linnean Society on May 24. In referring to the discovery and subsequent remarkable disappearance of the Tile-fish (Lopholatilus chamœleonticeps), I stated that ...

Electronic Resource

1432-1440

Insulin infusion pump ; Implantation ; CSII ; Intravenous, intraperitoneal insulin infusion

Springer Online Journal Archives 1860-2000

Medicine

Summary Five type I diabetic patients were followed prospectively during treatment with continuous subcutaneous insulin infusion by externally worn pumps and during the first 12 months after implantation of a remote-controlled insulin infusion device (ID1, Siemens AG). Stabilized insulin (Hoe 21 GH, Hoechst AG) was infused intravenously in two and intraperitoneally in three patients. Total observation time was 47.2 patient-months after implantation. Two devices had to be explanted prematurely, one because of a technical failure after 101 days, one due to a skin necrosis over the implant after 236 days. HbA1, frequency of hypoglycemia, total insulin dose, and basal rate infusion did not change after implantation. There was a reduction in the insulin antibodies 6 months after start of intravenous or intraperitoneal insulin delivery. Fasting plasma free insulin levels could be normalized only by intraperitoneal insulin infusion. Although a technical and a surgical problem was observed, our data show the successful implantation and clinical use of programmable dosing devices and stabilized insulin.

Electronic Resource