Size-dependent influence of NOx on the growth rates of organic aerosol particles.

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains largely unclear. Here, we examine the response of particle growth to the changes of HOM formation caused by NOx. We show that NOx suppresses particle growth in general, but the suppression is rather nonuniform and size dependent, which can be quantitatively explained by the shifted HOM volatility after adding NOx. By illustrating how NOx affects the early growth of new particles, a critical step of CCN formation, our results help provide a refined assessment of the potential climatic effects caused by the diverse changes of NOx level in forest regions around the globe.

Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry.

Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosol nucleation. Based on quantum chemical calculations it has been suggested that the quantitative detection of gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased in the presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was set up at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection of H2SO4 in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time in the CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF (Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutral sulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presence of dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS represents only a fraction of the total H2SO4, contained in the monomer and the clusters that is available for particle growth. Although it was found that the addition of dimethylamine dramatically changes the H2SO4 cluster distribution compared to binary (H2SO4-H2O) conditions, the CIMS detection efficiency does not seem to depend substantially on whether an individual H2SO4 monomer is clustered with a DMA molecule. The experimental observations are supported by numerical simulations based on A Self-contained Atmospheric chemistry coDe coupled with a molecular process model (Sulfuric Acid Water NUCleation) operated in the kinetic limit.

New particle formation in the free troposphere: A question of chemistry and timing.

New particle formation (NPF) is the source of over half of the atmosphere's cloud condensation nuclei, thus influencing cloud properties and Earth's energy balance. Unlike in the planetary boundary layer, few observations of NPF in the free troposphere exist. We provide observational evidence that at high altitudes, NPF occurs mainly through condensation of highly oxygenated molecules (HOMs), in addition to taking place through sulfuric acid-ammonia nucleation. Neutral nucleation is more than 10 times faster than ion-induced nucleation, and growth rates are size-dependent. NPF is restricted to a time window of 1 to 2 days after contact of the air masses with the planetary boundary layer; this is related to the time needed for oxidation of organic compounds to form HOMs. These findings require improved NPF parameterization in atmospheric models.

Freezing of stallion semen with addition of glycine betaine.

The effect of addition of glycine betaine to a lactose-EDTA freezing medium on the post-thaw motility of stallion semen was determined. The first three semen-rich fractions of nine stallions were collected with an open-end Krakow artificial vagina on consecutive weekdays. Semen was frozen using the Hannover method with freezing media containing glycine betaine in various concentrations from 0 to 5%. After thawing, sperm motility was analysed both by a light microscope and by a Hamilton-Thorn Motility Analyser. Total and progressive post-thaw motilities of semen containing 0.25-3% glycine betaine did not differ significantly from the total and progressive post-thaw motilities of semen frozen without glycine betaine. The total and progressive post-thaw motilities of semen containing 4 or 5% glycine betaine were significantly lower (P < 0.001) than those of semen without glycine betaine. In conclusion, glycine betaine did not show any beneficial effect on the post-thaw motility of stallion semen when semen was frozen using the Hannover method.

[Intrauterine device-associated genital actinomycosis. Diagnosis and therapy with reference to five case reports]. / Die Intrauterinpessar-assoziierte genitale Aktinomykose. Diagnostik und Therapie anhand von fünf Fallbeobachtungen.

Between 1992 and the beginning of 1993, 5 patients attending the gynecological department of the Charité Hospital in Berlin were treated for IUP-associated actinomycosis. The IUP had been used by these women for periods of between five and sixteen years. The primary diagnosis was established on the basis of a histological examination in three cases. In two cases, dysplasias had been diagnosed on the basis of the cytological examination. In one case, the primary diagnosis was suspected by the finding of actinomycetes in the cytological preparation. The treatment of choice is high-dose intravenous penicillin administered over the long term.

[Non-puerperal mastitis in real time and color Doppler ultrasound]. / Die Mastitis nonpuerperalis in der Realtime- und Farbdoppler-Sonographie.

Differential diagnosis distinguishing between nonpuerperal mastitis and inflammatory cancer of the breast is difficult, the conventional method being mammography. In our study, we present the typical findings gained by sonography of 16 patients with nonpuerperal mastitis. They do not differ significantly from those cases with breast cancer. From these 16 patients, 7 were additionally examined using Colour and Pulsed Wave Doppler Sonography. International literature offers little practical knowledge in this field. In the immediate surroundings of the inflammation, we were able to represent up to four arterial vessels per patient. The parameters of the flow velocity wave form of these vessels were compared to those of the vessels in the correspondent quadrant of the contralateral breast. In all cases, the maximum systolic and the minimum end diastolic velocities were higher than in the contralateral breast, giving evidence of an increased vascularity. In 6 cases, the pulsatility and resistance indices in the inflammatory vessels were lower because of a decreased peripheral resistance of the vessel. Under therapy with antibiotics or Bromocriptine, these parameters were equalized in both breasts. The model of nonpuerperal mastitis shows, that Colour and Pulsed Wave Doppler Sonography makes it possible to differentiate tumours of the breast on the basis of an analysis of their vascularity and the comparison with the parameters of the vessels in the contralateral breast. The effects of a pharmacological therapy on the vascularity of breast tumours can also be measured with this method.

[Mechanical recanalization of chronic coronary artery occlusion by balloon dilatation. Hemodynamic and ventricular kinetic long-term results]. / Mechanische Rekanalisation chronischer Koronararterienverschlüsse durch Ballondilatation. Hämodynamische und ventrikelkinetische Langzeitergebnisse.

Abundant collaterals may prevent infarction in a region of myocardium supplied by an acutely occluded coronary artery. However, these patients often present with severe angina on exertion which cannot be sufficiently treated with antianginal drugs but require revascularization. Beginning in 1984, recanalization of chronic coronary artery occlusion using balloon catheters was attempted in 48 patients at Medizinische Klinik III, University of Cologne. Interventional therapy was successful in 29/48 patients (60%). The mean diameter narrowing of residual stenoses was 35%. Invasive follow-up at 3 months was possible in 17 of these 29 patients. Restenosis was noted in 41% and reocclusion was found in 18%. In contrast to angiographic findings, clinical symptoms were clearly improved in the majority of cases (88%). This correlates with increased regional contractility of the myocardial region supplied by the previously occluded artery. Contractility was also improved in patients with significant restenosis. The clinical benefit and the improvement of regional myocardial function indicate that it is justified to attempt balloon recanalization in highly symptomatic patients with short distance coronary occlusions despite the relatively high incidence of restenosis and reocclusion.