Metals from spacecraft reentry in stratospheric aerosol particles.

Large increases in the number of low earth orbit satellites are projected in the coming decades [L. Schulz, K.-H.

Pyrocumulonimbus affect average stratospheric aerosol composition.

Pyrocumulonimbus (pyroCb) are wildfire-generated convective clouds that can inject smoke directly into the stratosphere. PyroCb have been tracked for years, yet their apparent rarity and episodic nature lead to highly uncertain climate impacts. In situ measurements of pyroCb smoke reveal its distinctive and exceptionally stable aerosol properties and define the long-term influence of pyroCb activity on the stratospheric aerosol budget.

HCOOH in the remote atmosphere: Constraints from Atmospheric Tomography (ATom) airborne observations.

Formic acid (HCOOH) is an important component of atmospheric acidity but its budget is poorly understood, with prior observations implying substantial missing sources. Here we combine pole-to-pole airborne observations from the Atmospheric Tomography Mission (ATom) with chemical transport model (GEOS-Chem CTM) and back trajectory analyses to provide the first global in-situ characterization of HCOOH in the remote atmosphere. ATom reveals sub-100 ppt HCOOH concentrations over most of the remote oceans, punctuated by large enhancements associated with continental outflow.

The contribution of black carbon to global ice nucleating particle concentrations relevant to mixed-phase clouds.

Black carbon (BC) aerosol plays an important role in the Earth's climate system because it absorbs solar radiation and therefore potentially warms the climate; however, BC can also act as a seed for cloud particles, which may offset much of its warming potential. If BC acts as an ice nucleating particle (INP), BC could affect the lifetime, albedo, and radiative properties of clouds containing both supercooled liquid water droplets and ice particles (mixed-phase clouds). Over 40% of global BC emissions are from biomass burning; however, the ability of biomass burning BC to act as an INP in mixed-phase cloud conditions is almost entirely unconstrained.

Global Measurements of Brown Carbon and Estimated Direct Radiative Effects.

Brown carbon (BrC) is an organic aerosol material that preferentially absorbs light of shorter wavelengths. Global-scale radiative impacts of BrC have been difficult to assess due to the lack of BrC observational data. To address this, aerosol filters were continuously collected with near pole-to-pole latitudinal coverage over the Pacific and Atlantic basins in three seasons as part of the Atmospheric Tomography Mission.

Efficient In-Cloud Removal of Aerosols by Deep Convection.

Convective systems dominate the vertical transport of aerosols and trace gases. The most recent in situ aerosol measurements presented here show that the concentrations of primary aerosols including sea salt and black carbon drop by factors of 10 to 10,000 from the surface to the upper troposphere. In this study we show that the default convective transport scheme in the National Science Foundation/Department of Energy Community Earth System Model results in a high bias of 10-1,000 times the measured aerosol mass for black carbon and sea salt in the middle and upper troposphere.

Chemical and physical transformations of aluminosilicate clay minerals due to acid treatment and consequences for heterogeneous ice nucleation.

Mineral dust aerosol is one of the largest contributors to global ice nuclei, but physical and chemical processing of dust during atmospheric transport can alter its ice nucleation activity. In particular, several recent studies have noted that sulfuric and nitric acids inhibit heterogeneous ice nucleation in the regime below liquid water saturation in aluminosilicate clay minerals. We have exposed kaolinite, KGa-1b and KGa-2, and montmorillonite, STx-1b and SWy-2, to aqueous sulfuric and nitric acid to determine the physical and chemical changes that are responsible for the observed deactivation.

Formation of semisolid, oligomerized aqueous SOA: lab simulations of cloud processing.

Glyoxal, methylglyoxal, glycolaldehyde, and hydroxyacetone form N-containing and oligomeric compounds during simulated cloud processing with small amines. Using a novel hygroscopicity tandem differential mobility analysis (HTDMA) system that allows varied humidification times, the hygroscopic growth (HG) of each of the resulting products of simulated cloud processing was measured. Continuous water uptake (gradual deliquescence) was observed beginning at ∼ 40% RH for all aldehyde-methylamine products.

Heterogeneous ice nucleation on simulated secondary organic aerosol.

In this study, we have explored the phase behavior and the ice nucleation properties of secondary organic aerosol made from aqueous processing (aqSOA). AqSOA was made from the dark reactions of methylglyoxal with methylamine in simulated evaporated cloud droplets. The resulting particles were probed from 215 to 250 K using Raman spectroscopy coupled to an environmental cell.

Impact of organic coating on optical growth of ammonium sulfate particles.

Light extinction by particles in Earth's atmosphere is strongly dependent on particle size, chemical composition, hygroscopic growth properties, and particle mixing state. Here, the influence of an organic coating on particle optical growth was studied. The particle optical growth factor, fRHext, was measured using cavity ring-down aerosol extinction spectroscopy at 532 nm.

Assessment of disease behavior in patients with Crohn's disease by MR enterography.

Background: Magnetic resonance imaging (MRI) of the bowel is an increasingly used modality to evaluate patients with Crohn's disease. The Montreal classification of the disease behavior is considered as an excellent prognostic and therapeutic parameter for these patients. In our study, we correlated the behavior assessment performed by a radiologist based on MRI with the surgeons' clinical assessment based on the assessment during abdominal surgery.

[Clinical significance of conventional follow-through examinations of the gastrointestinal passage in a university hospital].

Purpose: The follow-through examination (FTE) is still a widely used radiological method. Modern sectional imaging techniques (CT, MRI, sonography) are established routine examinations offering a wider range of information. In this context the study tries to answer the question of the current significance of FTE of the gastrointestinal tract.

Depositional ice nucleation on monocarboxylic acids: effect of the O:C ratio.

The heterogeneous ice nucleation efficiency of a series of thin C3-C6 monocarboxylic acid films between 180 and 200 K has been investigated using a Knudsen cell flow reactor. At each temperature, the critical ice saturation ratio for depositional nucleation as well as the effective contact angle was found to be strongly dependent on the chemical nature of the film. For the organic acids used in this study, increasing the O:C ratio lowered the supersaturation required for the onset of heterogeneous ice nucleation and decreased the effective angle of contact.

Comparison of high-resolution ultrasound and MR-enterography in patients with inflammatory bowel disease.

Aim: To compare the results of high-resolution ultrasound (HR-US) and magnetic resonance enterography (MRE) examinations in patients with inflammatory bowel disease (IBD).

Methods: The reports of 250 consecutive cases with known IBD, who had an MRE and HR-US examination, were retrospectively analyzed. Using a patient-based approach we evaluated morphological disease features such as affected bowel wall, stenosis, abscess and fistula.

Influence of percutaneous abscess drainage on severe postoperative septic complications in patients with Crohn's disease.

Purpose: Severe postoperative intra-abdominal septic complications (IASC) such as an anastomotic leak, intra-abdominal abscess, and fistula are significantly associated with the presence of spontaneous intra-abdominal abscess at the time of laparotomy in patients with Crohn's disease (CD). The purpose of this study was to compare the incidence of severe postoperative IASC in patients undergoing intestinal resections with and without preoperative percutaneous abscess drainage (PAD) before definitive surgery.

Methods: Using a prospective surgical database, we searched for patients with CD and spontaneous intra-abdominal abscesses who underwent intestinal resection at our hospital from May 2005 to February 2009.

Pharmacy-based bone mass measurement to assess osteoporosis risk.

Objective: To evaluate elderly women's knowledge of their skeletal status, assess adequacy of calcium intake, determine the prevalence of low bone density, and determine whether peripheral bone density testing led to medical interventions in a group of rural, elderly Wisconsin women recruited in community pharmacies.

Design: Recruiting notices were posted in each pharmacy, and eligible women were enrolled in the order in which they volunteered. Each completed a fracture-risk questionnaire.

Osteoporosis screening by community pharmacists: use of National Osteoporosis Foundation resources.

Objectives: To assess the feasibility of establishing an osteoporosis screening program in rural community pharmacies based on information and resources provided by the National Osteoporosis Foundation (NOF), to survey primary care providers regarding the usefulness of this screening program, and to recommend strategies for pharmacists interested in working with patients at risk for osteoporosis.

Design And Participants: Pharmacists and/or nurses enrolled women 65 years of age and older into the study, measured calcaneal bone density, administered a questionnaire to ascertain subjects' osteoporosis risk factors, and provided NOF literature to subjects. With their agreement, women's bone mass data and risk factor assessments were provided to primary care providers along with NOF's Physician's Guide to Prevention and Treatment of Osteoporosis.

Retention processes on alpha 1-acid glycoprotein-bonded stationary phase.

Stereoselective separations of charged enantiomers on CHIRAL-AGP can be controlled by varying the pH and adding charged and uncharged additives to the mobile phase. The interaction with the selector, alpha 1-acid glycoprotein, was studied by monitoring the effects of the variables on retention and by indirect detection, in part using a simple multivariate design. The stereoselectivity is due to simultaneous retention processes involving ion-exchange and ion-pairing mechanisms.

Liquid chromatographic separation of the enantiomers of metoprolol and its alpha-hydroxy metabolite on Chiralcel OD for determination in plasma and urine.

The two enantiomers of metoprolol and the four enantiomeric forms of alpha-hydroxymetoprolol were separated by liquid chromatography on a Chiralcel OD column containing a cellulose tris(3,5-dimethyl-phenylcarbamate) chiral stationary phase. The column efficiency was strongly dependent on the flow-rate and the enantioselectivity was influenced by temperature. Of utmost importance for the chiral separation was the water content of the mobile organic phase.

Enantioselective determination of metoprolol in plasma by liquid chromatography on a silica-bonded alpha 1-acid glycoprotein column.

The enantiomers of metoprolol were determined in plasma samples after direct resolution on a silica bonded alpha 1-acid glycoprotein column. Metoprolol was extracted from plasma into a diethyl ether-dichloromethane mixture and after back extraction to dilute phosphoric acid and adjustment of pH the sample was injected on a Chiral-AGP column for separation of R- and S-metoprolol. It was possible to measure down to 2 nmol per litre plasma with a relative standard deviation of less than 15% by use of gradient elution and fluorescence detection.

Application of indirect detection methods in biomedical analysis.

Indirect detection is a technically simple method to follow and quantify compounds without inherent detector response in high-performance liquid chromatography. A detectable component is added to the mobile phase and peaks are obtained for injected solutes as well as for mobile phase additives (system peaks). The underlying principle can be expressed by simple equations which show how the detection sensitivity can be optimized.

Chiral separations of cationic and anionic drugs on an alpha 1-acid glycoprotein-bonded stationary phase (EnantioPac). II. Influence of mobile phase additives and pH on chiral resolution and retention.

The influence of mobile phase additives and pH on chiral resolution and retention on a high performance liquid chromatographic chiral stationary phase composed of alpha 1-acid glycoprotein bonded to diethylaminoethyl silica (EnantioPac) has been investigated. Cationic and anionic compounds of widely differing structures were chromatographed and drastic effects on stereoselectivity were observed with hydrophobic charged modifiers. For cationic solutes, a decrease in the pH of the mobile phase from 7.