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Search Results: 1 - 10 of 144416 matches for " F. Sonnemann "
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Experimental and numerical analysis on PCB coupling in non uniform field environment
F. Sonnemann
Advances in Radio Science : Kleinheubacher Berichte , 2004,
Abstract: HPM and UWB pulses are capable of disrupting signal processing or even destroying semiconductor structures. Hence, it is useful to estimate the induced voltage levels on printed circuit boards (PCB) in response to different excitation signals. The considered PCB is integrated within a missile-like cylindrical structure, called GENEC, and is equipped with differential sensors to measure the E- and Hfield above the PCB. Standard transmission line theory is applied to develop a SPICE model that calculates the terminal voltages at the transmission line loads.
Comparative evaluation of the treatment efficacy of suberoylanilide hydroxamic acid (SAHA) and paclitaxel in ovarian cancer cell lines and primary ovarian cancer cells from patients
Jürgen Sonnemann, Jennifer G?nge, Sabine Pilz, Christine St?tzer, Ralf Ohlinger, Antje Belau, Gerd Lorenz, James F Beck
BMC Cancer , 2006, DOI: 10.1186/1471-2407-6-183
Abstract: We compared a prototypic histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), and paclitaxel for their treatment efficacy in ovarian cancer cell lines and in primary patient-derived ovarian cancer cells. The primary cancer cells were isolated from malignant ascites collected from five patients with stage III ovarian carcinomas. Cytotoxic activities were evaluated by Alamar Blue assay and by caspase-3 activation. The ability of SAHA to kill drug-resistant 2780AD cells was also assessed.By employing the cell lines OVCAR-3, SK-OV-3, and A2780, we established SAHA at concentrations of 1 to 20 μM to be as efficient in inducing cell death as paclitaxel at concentrations of 3 to 300 nM. Consequently, we treated the patient-derived cancer cells with these doses of the drugs. All five isolates were sensitive to SAHA, with cell killing ranging from 21% to 63% after a 72-h exposure to 20 μM SAHA, while four of them were resistant to paclitaxel (i.e., <10% cell death at 300 nM paclitaxel for 72 hours). Likewise, treatment with SAHA led to an increase in caspase-3 activity in all five isolates, whereas treatment with paclitaxel had no effect on caspase-3 activity in three of them. 2780AD cells were responsive to SAHA but resistant to paclitaxel.These ex vivo findings raise the possibility that SAHA may prove effective in the treatment of paclitaxel-resistant ovarian cancer in vivo.Ovarian cancer is the most lethal gynaecological neoplasm, accounting for over 6% of deaths from cancer in women [1]. The standard treatment is a combination of surgery and chemotherapy, the latter usually consisting of a taxane/platinum combination. By this regimen, initial response rates of more than 80% are achieved [2]. Unfortunately, in the vast majority of women, diagnosis occurs after the disease has already disseminated beyond the ovaries. These patients typically relapse and eventually die as the tumours become refractory to treatment. Actually, drug resistance is supposed to
Upper stratospheric ozone decrease events due to a positive feedback between ozone and the ozone dissociation rate
G. R. Sonnemann,P. Hartogh
Nonlinear Processes in Geophysics (NPG) , 2009,
Abstract: Ozone measurements taken with a ground based microwave instrument at Lindau (51.66° N, 10.13° E) over some years showed strong ozone decrease events within the stratopause region, particularly during the winter half-year. These events are characterized by a marked drop of the ozone mixing ratio from two to three ppmv to less than half a ppmv in extreme cases. Simultaneous water vapor measurements at the same place, also carried out by a microwave instrument, showed a strong increase of its mixing ratio and the temperature was also enhanced during these episodes. The theoretical analysis brought evidence that these events result from a positive feedback in the complex radiatively-chemical system between the ozone column density and the ozone dissociation rate.
On the two-day oscillations and the day-to-day variability in global 3-D-modeling of the chemical system of the upper mesosphere/mesopause region
G. R. Sonnemann ,M. Grygalashvyly
Nonlinear Processes in Geophysics (NPG) , 2005,
Abstract: The integration of the photochemical system of the upper mesosphere/mesopause region brought evidence that the system is able to respond in a nonlinear manner under certain conditions. Under the action of the diurnally-periodic insolation, the system creates subharmonic oscillations or chaos if disregarding strong diffusion, and under special conditions it possesses multiple solutions. The models used in the past were simplified and idealized in view of the number of dimensions and the consideration of the full dynamics. On the basis of our global 3-D-model of the dynamics and chemistry of the middle atmosphere (COMMA-IAP), we also found a nonlinear response in the photochemistry under realistic conditions. The model under consideration is not yet self-consistent, but the chemical model uses the dynamical fields calculated by the dynamic model. From our calculations we got period-2 oscillations of the photochemical system within confined latitudinal regions around the solstices but not during the equinoxes. The consequence of the period-2 oscillation of the chemical active minor constituents is that a marked two-day variation of the chemical heating rates is an important thermal pumping mechanism. We discuss these findings particularly in terms of the influence of realistic dynamics on the creation of nonlinear effects.
Long-term trends of the concentration of the minor constituents in the mesosphere – a model study
M. Grygalashvyly,G. R. Sonnemann,P. Hartogh
Atmospheric Chemistry and Physics Discussions , 2007,
Abstract: We investigate the influence of the rising concentrations of methane, dinitrogen oxide and carbon dioxide since the pre-industrial era upon the chemistry of the mesosphere. We use for calculations our global 3D-model COMMA-IAP designed for the exploration of the MLT-region and particularly the extended mesopause region. In order to get approximated data of the solar Lyman-α flux back to the pre-industrial time, we derived a quadratic fit using the sunspot number available since 1749 as the only solar proxy for the Lyman-α flux before 1947. The Lyman-α flux values are employed to determine the water vapor dissociation rate. The water vapor trend analysis utilizes estimated methane trends since the pre-industrial era. An unsolved problem for the model calculations consists of the water vapor mixing ratio at the hygropause during the time range of trend calculation. We assume that the hygropause was dryer at the pre-industrial time than currently. As a consequence of the methane oxidation, the middle atmosphere became more humid according to the rising methane concentration, but depending on height and with a small time delay of few years. The solar influence on the water vapor mixing ratio is insignificant below about 80 km within summery high latitudes, but it becomes increasingly more important above this altitude. The growing water vapor concentration increases the hydrogen radical concentration and reduces the mesospheric ozone. A second region of stronger ozone decrease is located in the vicinity of the stratopause. Increasing CO2 concentration enhances slightly the concentration of CO in the mesosphere, but its influence upon the chemistry is small and its main effect is connected with a cooling of the upper atmosphere. We discuss the trends particularly in view of the impact on the NLC region.
Long-term behavior of the concentration of the minor constituents in the mesosphere – a model study
M. Grygalashvyly,G. R. Sonnemann,P. Hartogh
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2009,
Abstract: We investigate the influence the rising concentrations of methane, nitrous oxide and carbon dioxide which have occurred since the pre-industrial era, have had on the chemistry of the mesosphere. For this investigation we use our global 3-D-model COMMA-IAP which was designed for the exploration of the MLT-region and in particular the extended mesopause region. Assumptions and approximations for the trends in the Lyman-α flux (needed for the water vapor dissociation rate), methane and the water vapor mixing ratio at the hygropause are necessary to accomplish this study. To approximate the solar Lyman-α flux back to the pre-industrial time, we derived a quadratic fit using the sunspot number record which extends back to 1749 and is the only solar proxy available for the Lyman-α flux prior to 1947. We assume that methane increases with a constant growth rate from the pre-industrial era to the present. An unsolved problem for the model calculations consists of how the water vapor mixing ratio at the hygropause should be specified during this period. We assume that the hygropause was dryer during pre-industrial times than the present. As a consequence of methane oxidation, the model simulation indicates that the middle atmosphere has become more humid as a result of the rising methane concentration, but with some dependence on height and with a small time delay of few years. The solar influence on the water vapor mixing ratio is insignificant below about 80 km in summer high latitudes, but becomes increasingly more important above this altitude. The enhanced water vapor concentration increases the hydrogen radical concentration and reduces the mesospheric ozone. A second region of stronger ozone decrease is located in the vicinity of the stratopause. Increases in CO2 concentration enhance slightly the concentration of CO in the mesosphere. However, its influence upon the chemistry is small and its main effect is connected with a cooling of the upper atmosphere. The long-term behavior of water vapor is discussed in particular with respect to its impact on the NLC region.
Treatment of Rhinitis Sicca Anterior with Ectoine Containing Nasal Spray
Uwe Sonnemann,Olaf Scherner,Nina Werkh?user
Journal of Allergy , 2014, DOI: 10.1155/2014/273219
Abstract: Objectives. The safety and efficacy of ectoine nasal spray and ectoine nasal spray with dexpanthenol in the treatment of rhinitis sicca were evaluated in two studies. Design and Methods. Two noninterventional observational studies were performed to evaluate the efficacy and safety of a nasal spray containing ectoine (study 1) and ectoine/dexpanthenol (study 2) over a period of two weeks including comparable numbers of patients suffering from rhinitis sicca anterior. Patients and physicians were asked to rate the efficacy in reducing symptoms and the tolerability over the treatment phase. Results. The treatment in both studies resulted in a clinical and statistical significant reduction of the main diagnosis parameters, nasal airway obstruction, and crust formation. There was also a significant reduction in the secondary diagnosis parameters in both studies. Importantly, the tolerability was very good. During the whole observational study, neither patients nor doctors stopped the medication due to unwanted effects. Conclusion. Rhinitis sicca could be successfully treated with a nasal spray containing ectoine and a nasal spray combining ectoine with dexpanthenol. The combination of both substances led to slight advantages. 1. Introduction Rhinitis sicca or generally speaking dry nose is a rather frequent problem involving many people. The term “dry nose” has not yet been uniformly defined [1]. Otolaryngologists often use the terms “rhinitis sicca” or “dry rhinitis,” although no clear definition exists. Many symptoms during dry nose could be encountered ranging from subjective sensation of the dry nose and itching up to mild burning, nasal obstruction, crusting associated with unpleasant smell, epistaxis, and diminished sense of smell. Rhinitis sicca anterior means a chronic inflammation in the region of the anterior part of the nose, affecting the anterior and caudal septum and/or the corresponding lateral nasal vestibule. Mechanical as well as environmental irritations lead to crust formation. In rare cases, patients suffer from a slight stench due to bacterial colonization of the crust formations. The treatment of rhinitis sicca involves mainly elimination of promoting factors, moistening, sufficient daily drinking amount, cleansing of the crusts, care of the mucosa and inhibition of possible infections, or in rare cases the elimination of overlarge endonasal space [1]. The main treatment for rhinitis sicca consists of humidification of the nose, especially the mucus, focusing in a real wash-out of possible inflammatory triggers and application of a
Treatment of Allergic Rhinitis with Ectoine Containing Nasal Spray and Eye Drops in Comparison with Azelastine Containing Nasal Spray and Eye Drops or with Cromoglycic Acid Containing Nasal Spray
Nina Werkh?user,Andreas Bilstein,Uwe Sonnemann
Journal of Allergy , 2014, DOI: 10.1155/2014/176597
Abstract: Objectives. Allergic rhinitis is a common disease with increasing prevalence and high impact on economic burden and comorbidities. As treatment with pharmacological drugs is not always satisfactory due to side effects and incomplete efficacy, alternative treatment strategies are needed. Ectoine is an osmolyte with membrane stabilizing and inflammation reducing capacities. Nasal spray and eye drops containing ectoine are promising new treatment regimens for allergic rhinitis sufferers. Design and Methods. The current two noninterventional trials evaluated the efficacy and safety of ectoine containing nasal spray and eye drops for treating allergic rhinitis in comparison with either azelastine or cromoglycic acid containing products. Nasal and ocular symptom developments as well as judgment of tolerability and efficacy were assessed both by investigators and patients over a time period of one to two weeks. Results. Both trials confirmed that ectoine containing products reduced nasal and ocular symptoms in allergic rhinitis patients. Results clearly demonstrated good safety profiles of the ectoine products comparable to those of azelastine and even better to those of cromoglycate products. Conclusion. Ectoine containing nasal spray and eye drops are interesting new treatment strategies for sufferers of allergic rhinitis, combining both good efficacy and absence of side effects. 1. Introduction Allergic rhinitis is a common disease affecting 10–20% of the population [1]. Since it has great impact on patients’ quality of life, school performance, work productivity, and comorbid conditions such as asthma, it is considered as an important health problem. Allergic rhinitis is defined as an allergic reaction (most often IgE-dependent) to offending allergens such as dust mites, insects, animal dander, and pollens. Symptoms include rhinorrhea, nasal obstruction, nasal and nasopharyngeal itching, sneezing, and postnasal drip. Often, allergic rhinitis is accompanied by allergic conjunctivitis with ocular symptoms such as itchy and watery eyes, resulting in the term allergic rhinoconjunctivitis. According to its length of duration, allergic rhinitis is classified into intermittent (symptoms present <4 days a week of <4 weeks) and persistent (symptoms present ≥ 4 days a week and for at least 4 weeks) forms. Symptom severity is used to classify allergic rhinitis into mild or moderate-severe forms. A number of pharmacological treatments of allergic rhinitis exist, such as, for example, oral and topical antihistamines, leukotriene receptor antagonists, intranasal
Noninterventional Open-Label Trial Investigating the Efficacy and Safety of Ectoine Containing Nasal Spray in Comparison with Beclomethasone Nasal Spray in Patients with Allergic Rhinitis
Uwe Sonnemann,Marcus M?ller,Andreas Bilstein
Journal of Allergy , 2014, DOI: 10.1155/2014/297203
Abstract: Objectives. The current study aimed to compare the efficacy and safety of a classical anti-inflammatory beclomethasone nasal spray in comparison to a physic-chemical stabilizing ectoine containing nasal spray in the treatment of allergic rhinitis. Design and Methods. This was a noninterventional, open-label, observational trial investigating the effects of beclomethasone or ectoine nasal spray on nasal symptoms and quality of life. Over a period of 14 days, patients were asked to daily document their symptoms. Efficacy and tolerability were assessed by both physicians and patients. Results. Both treatments resulted in a significant decrease of TNSS values. An equivalence test could not confirm the noninferiority of ectoine treatment in comparison with beclomethasone treatment. Although clear symptom reduction was achieved with the ectoine products, the efficacy judgment showed possible advantages for the beclomethasone group. Importantly, tolerability results were comparably good in both groups, and a very low number of adverse events supported this observation. Both treatments resulted in a clear improvement in the quality of life as assessed by a questionnaire answered at the beginning and at the end of the trial. Conclusion. Taken together, it was shown that allergic rhinitis can be safely and successfully treated with beclomethasone and also efficacy and safety were shown for ectoine nasal spray. 1. Introduction Allergic rhinitis is a common disease with estimated 600 million patients suffering from this disease worldwide [1]. According to a large scale investigation, about 20% of the European population suffers from allergic rhinitis [2] and numbers are increasing, particularly in industrial states. Although not being a life-threatening disease, allergic rhinitis has a considerable impact on general well-being and work/school performance, and particularly its impact on comorbidities such as, for example, asthma reflects the need for good treatment options. A number of pharmacological treatments against allergic rhinitis exist, such as antihistamines, leukotriene receptor agonists, mast cell stabilizing agents, and glucocorticosteroids. According to the ARIA (Allergic Rhinitis and its Impact on Asthma) guidelines, intranasal glucocorticosteroids are recommended as pharmacological treatment of allergic rhinitis and should be prescribed preferable to intranasal antihistamines and oral leukotriene receptor agonists [1]. However, many patients have reservations to use corticosteroids, and phobia of their usage can result in bad compliance [3]. This
β-Actin and γ-Actin Are Each Dispensable for Auditory Hair Cell Development But Required for Stereocilia Maintenance
Benjamin J. Perrin,Kevin J. Sonnemann,James M. Ervasti
PLOS Genetics , 2010, DOI: 10.1371/journal.pgen.1001158
Abstract: Hair cell stereocilia structure depends on actin filaments composed of cytoplasmic β-actin and γ-actin isoforms. Mutations in either gene can lead to progressive hearing loss in humans. Since β-actin and γ-actin isoforms are 99% identical at the protein level, it is unclear whether each isoform has distinct cellular roles. Here, we compared the functions of β-actin and γ-actin in stereocilia formation and maintenance by generating mice conditionally knocked out for Actb or Actg1 in hair cells. We found that, although cytoplasmic actin is necessary, neither β-actin nor γ-actin is required for normal stereocilia development or auditory function in young animals. However, aging mice with β-actin– or γ-actin–deficient hair cells develop different patterns of progressive hearing loss and distinct pathogenic changes in stereocilia morphology, despite colocalization of the actin isoforms. These results demonstrate overlapping developmental roles but unique post-developmental functions for β-actin and γ-actin in maintaining hair cell stereocilia.
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