Search Results - (Author, Cooperation:M. Heinemann)

2012-05-05

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Adaptation, Physiological ; Adenosine Triphosphate/metabolism ; Aerobiosis ; Algorithms ; Bacteria/growth & development/*metabolism ; *Biological Evolution ; Biomass ; Computer Simulation ; Escherichia coli/genetics/growth & development/*metabolism ; Glucose/metabolism ; *Metabolic Networks and Pathways ; Models, Biological

1077-3118

AIP Digital Archive

Physics

This letter presents experimental results of a scheme for encrypted acoustic communication in the reverberant environment of an enclosure using single-channel time-reversal acoustics. Because time-reversal acoustics in an enclosure can focus a signal within a half wavelength of sound, it possesses natural encryption for points other than the intended receiver. In this way, distinct multiple messages can be sent simultaneously from one source to different locations in the enclosure. The communication scheme is based on multiple broadband signals with identical bandwidth and windowed source spectra.

Electronic Resource

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource

0005-2744

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0039-6028

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0375-9474

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0375-9474

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0375-9474

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0375-9474

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0304-4165

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

0304-4165

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

1432-1440

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

0169-4332

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

1433-0458

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] UNTIL now, there has been only one physical method for detecting Gurwitsch rays, namely, with the Geiger-Müller, electron counter. Using this method, some workers1 have got positive results, whilst other investigators2 have not been able to confirm them. The method ...

Electronic Resource

1432-1076

Key words Inhaled nitric oxide ; Platelet aggregation ; Platelet surface receptors ; Platelet adhesion molecules ; Intracellular cyclic guanosine monophosphate

Springer Online Journal Archives 1860-2000

Medicine

Abstract Nitric oxide (NO) reduces platelet aggregation in vitro. However, repeated measurements of platelet aggregation in infants and small children are impossible due to the large blood samples required. Instead, the expression of different platelet receptors mediating platelet adhesion (CD 36 and CD 42b), activation (CD 42b and CD 61) and aggregation (CD 41a) was measured repeatedly by flow cytometry. First, the expression of platelet receptors was quantified in platelet suspensions of 20 healthy volunteers after incubation with different concentrations of NO (0, 25, 100 and 640 ppm) and compared to changes in platelet aggregation and intrathrombocytic cGMP levels. It was then studied in 21 infants and children before, during and up to 3 days after cardiopulmonary bypass surgery. Seven of these patients required NO inhalation postoperatively. The in vitro experiments showed a reduced expression of the CD 41a, CD 42b and CD 61 receptors with increasing doses of NO, predominantly affecting the CD 41a receptor (−11% at 100 ppm and −20% at 640 ppm). This significant effect is in keeping with the observed NO-induced inhibition of platelet aggregation (−44% at 100 ppm) and the rise in platelet cGMP levels (+69% at 100 ppm). In patients without inhaled NO, the expression of CD 41a was slightly attenuated during cardiopulmonary bypass surgery (−15%) but increased significantly afterwards (2 h: +31%, 1st day: +129%, 2nd day: +120%, 3rd day: +111%). Comparable results were obtained regarding the other adhesion molecules CD 36, CD 42b and CD 61. In patients with inhaled NO the same pattern was observed and analysis of variance did not reveal any significant difference between both groups of patients. Conclusions NO (≥100 ppm) decreases the expression of different platelet adhesion molecules and platelet aggregation, presumably via an increase in intracellular cGMP. However, due to the low dose range used in the clinical setting (1–40 ppm) this is clinically not relevant. Immediately after cardiopulmonary bypass surgery the expression of these adhesion molecules is reduced, but recovers on the 1st postoperative day.

Electronic Resource

1615-6714

Springer Online Journal Archives 1860-2000

Medicine

Summary Fortythree out of 148 patients who had undergone velopharyngeal flap graft between 1980 and 1992 to treat velopharyngeal insufficiency, and for whom pre- and postoperative data were available, were studied for the purpose of determining the long term morphological functional results of the treatment. Almost all of the 43 patients (93,5%) had received a velopharyngeal flap graft according toSanvenero-Rosselli. The remaining 4.7% had received a velopharyngeal adhesion according toStellmach. Four physicians from the fields of oral surgery, orthodontics, phoniatries, and logopedies evaluated the pre- and postoperative data as well as the results of the follow-up examination according to subjective criteria from their respective disciplines. All four physicians judged that following velopharyngeal flap graft a gradual improvement in the ability to speak had been achieved in 86% of the patients in the follow-up study. At the time of the follow-up examination 70% of these cases were judged to have achieved a “good” qualitative level of articulation and 21% were judged to have achieved a “usefull” level. The best results were obtained in patients who had been operated on before the age of six. The reason is that in these young patients muscular malfunction and pathological movement patterns can be more easily modified than in okler patients. In many cases additional speech improvement was achieved through logopedical therapy following the velopharyngeal flap graft. In the most difficult cases intensive therapy while the patients were still hospitalized proved to be especially effective. The pre-operative use of transnasal flexible endoscopy to evaluate the interaction of the structures bearing on velopharyngeal closure proved its value in evaluating velopharyngeal flap graft's chances of success. Velopharyngeal flap graft thus offers the possibility of an efficacious treatment of velopharyngeal insufficiency, if both the preoperative diagnosis and postoperative therapy draw on the expertise of the above noted fields in an interdisciplinary common effort in which the limits of the treatment method are clearly taken into consideration.

Zusammenfassung Von 148 Patienten, bei denen im Zeitraum von 1980 bis 1992 wegen einer velopharyngealen Insuffizienz eine Velopharyngoplastik durchgeführt wurde sowie prä- und postoperative Befunde vorlagen, wurden 43 Betroffene zur Einschätzung der morphologischen und funktionellen Spätresultate nachuntersucht. Bei 95,3% aller nachuntersuchten Patienten wurde eine Velopharyngoplastik nachSanvenero-Rosselli [15] und bei 4,7% eine Velopharynxadhäsion nachStellmach [19] durchgeführt. Die prä- und postoperative Beurteilung sowie die Nachuntersuchung erfolgten dabei nach subjektiven Kriterien durch Fachvertreter der Kieferchirurgie, Kieferorthopädie, Phoniatrie und Logopädie. Bei 86% der nachuntersuchten Patienten konnte nach Beurteilung aller Fachvertreter eine graduelle Sprachverbesserung mit einer Velopharyngoplastik erreicht werden. Zum Zeitpunkt der Nachuntersuchung war die Sprachqualität in 70% der Fälle gut und bei 21% branchbar beurteilt worden. Bei einer sprachverbessernden Operation vor dem sechsten Lebensjahr wirden die besten Ergebnisse erreicht, da zu diesem Zeitpunkt muskuläre Fehlfunktionen und pathologische Bewegungsmuster noch leichter umgestellt werden können. Eine weitere Verbesserung der Sprachqualität konnte in vielen Fällen durch eine logopädische Übungsbehandlung nach der Velopharyngoplastik erzielt werden. Die stationäre Intensivtherapie hat sich besonders bei schweren Fällen bewährt. Zur Abschätzung der Erfolgsaussichten einer Velopharyngoplastik hat sich die präoperative transnasale flexible Endoskopie zur Beurteilung des Zusammenspiels der am velopharyngealen Verschluß beteiligten Strukturen bewährt. Bei einer sachgerechten Indikationsstellung und effektiven Behandlung unter kritischer Berücksichtigung der Grenzen dieser Methodik in interdisziplinärer Zusammenarbeit ist die Velopharyngoplastik eine gute Möglichkeit zur Behandlung der velopharyngealen Insuffienz.

Electronic Resource

1435-4373

Springer Online Journal Archives 1860-2000

Medicine

Abstract The efficacy and safety of a combination of ganciclovir plus GM-CSF was evaluated in AIDS patients with cytomegalovirus retinitis. In phase A, patients were randomized to receive ganciclovir, 5 mg/kg every 12 h for 14 days followed by 5 mg/kg daily, with (n=24) or without (n=29) GM-CSF (1–8 µg/kg daily subcutaneously) to maintain absolute neutrophil counts between 2500 and 5000 cells/µl. In phase B, after 16 weeks zidovudine was added to the regimen of 16 patients receiving ganciclovir plus GM-CSF and 20 receiving ganciclovir alone. At this stage, GM-CSF was added to the treatment protocol of any patient receiving ganciclovir plus zidovudine who became neutropenic. In phase A, patients in the ganciclovir plus GM-CSF group had significantly higher neutrophil counts than ganciclovir-alone patients (p=0.0001). Overall, 12.5 % of patients treated with GM-CSF developed neutropenia (absolute neutrophil counts〈500/µl phase A and〈750/µl phase B) compared with 45 % of patients treated without GM-CSF. GM-CSF patients missed 10 of a possible 4705 scheduled doses of ganciclovir compared with 34 missed doses of a possible 6584 in the ganciclovir-alone group (p=0.011). There was a trend, although not statistically significant, for patients in the GM-CSF group to experience delayed progression of their retinitis. There was no consistent evidence that GM-CSF stimulated the proliferation of cytomegalovirus or human immunodeficiency virus in the GM-CSF group compared with patients receiving ganciclovir alone. The addition of GM-CSF to standard ganciclovir therapy for the treatment of cytomegalovirus retinitis reduced the haematological toxicity of the antiviral drug and allowed closer adherence to the dosage schedule. In addition, patients were able to receive concomittant zidovudine therapy.

Electronic Resource

1435-4373

Springer Online Journal Archives 1860-2000

Medicine

Abstract  The in vitro effects of meropenem on Pseudomonas aeruginosa were examined by studying (i) the inhibitory and bactericidal concentrations of meropenem versus those of imipenem for clinical isolates; (ii) changes in bacterial morphology during in vitro culture; and (iii) release of endotoxin induced by meropenem compared with that induced by other antipseudomonal compounds. Meropenem MIC90 and MBC90 values for 108 clinical isolates were 2 and 4.8 mg/l compared to 4.5 and 9.6 mg/l for imipenem. Morphological studies using phase-contrast and scanning electron microscopy showed that meropenem induced the formation of indeterminate bacterial cell forms at drug concentrations of 1–2.5 mg/l (0.5- to 1.25-fold the MIC), while spheroplasts predominated at drug levels exceeding 5 mg/l (2.5-fold the MIC). Determination of free and EDTA-releasable endotoxin activity by means of the Limulus lysate test showed that both meropenem and imipenem liberated significantly less endotoxin than did ceftazidime. Therefore, although meropenem binds to penicillin-binding proteins (PBPs) 2 and 3 (in contrast to imipenem, which binds to PBP2 only), endotoxin release should not be a cause of concern when treating systemic gram-negative infections with this drug.

Electronic Resource

1572-946X

Springer Online Journal Archives 1860-2000

Physics

Abstract Stellar winds from a binary star pair will interact with each other along a contact discontinuity. We discuss qualitatively the geometry of the flow and field resulting from this interaction in the simplest case where the stars and winds are identical. We consider the shape of the critical surface (defined as the surface where the flow speed is equal to the sound speed) as a function of stellar separation and the role of shock waves in the flow field. The effect of stellar spin and magnetic sectors on the field configuration is given. The relative roles of mass loss and magnetic torque in the evolution of orbital parameters are discussed.

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