Effectiveness of intensive medical therapy in type B aortic dissection: A single-center experience

ObjectiveAlthough the mainstay of managing acute descending thoracic aortic dissection (ADTAD) remains medical, certain patients will require emergency surgery for complications of rupture or ischemia. This study evaluates factors that affect outcome and determines which patients previously treated surgically would have been eligible for endovascular repair.MethodsA single-institution retrospective study was conducted of patients who presented with clinical signs of ADTAD that was confirmed by magnetic resonance angiography (MRA) or computed tomography (CT). All patients were admitted to the intensive care unit (ICU) and medically managed to maintain systolic blood pressure <120 mm Hg and heart rate <70 beats/min. Two treatment groups were identified: group 1 received medical treatment only; group 2 received medical treatment plus emergency surgery. Patient demographic and clinical data were correlated with 30-day group mortality and morbidity and need for emergency surgery. The MRA and CT scan images of group 2 were retrospectively reviewed to determine if currently available endovascular treatment could have been done. The Fisher exact test was used to compare between the groups, and P < .05 was considered significant.ResultsBetween 1991 and 2005, 83 patients (55 men) were treated for ADTAD. The mean age was 67 years (range, 38 to 85). Sixty-eight patients (82%) had hypertension, three (3.6%) had Marfan syndrome, and 51 (62%) were smokers. Twenty-five (32%) of the patients were receiving β-blocker therapy before the onset of their symptoms. Back pain was the most common initial symptom (72.2%). Emergency surgery was required in 19 patients (23%): 12 for rupture or impending rupture, four for mesenteric ischemia, and three for lower extremity ischemia. The need for emergency surgery was significantly higher in smokers (P = .03), in patients >70 years old (P = .035), and in patients who were not receiving β-blocker therapy before the onset of symptoms (P = .023). The combined overall morbidity rate was 33%, and the mortality rate was 9.6%. Morbidity in group 2 was 64% and significantly higher than the 23% in group 1 (P = .00227). The mortality rate was also higher in group 2 at 31.5% compared with group 1 at 1.6% (P = .0004). Factors affecting the overall mortality included age >70 years (P = .057), previous abdominal aortic aneurysm repair (P = .018), tobacco use (P = .039), and the presence of leg pain at initial presentation (P = .013). As determined from the review of radiologic data, 11 of 13 patients with scans available for review in group 2 could have been treated with currently available endovascular grafts.ConclusionsIntensive medical therapies are effective in preventing early mortality associated with ADTAD. Predictably, the need for emergency surgery carries a high morbidity and mortality rate. Most patients in this series requiring emergency surgery could have been candidates for endovascular therapy had it been available

Response of Soybean Insects to Foliar Applications of a Chitin Synthesis Inhibitor TH 6040

The activity of TH 6040, a chitin synthesis inhibitor, was determined against velvetbean caterpillar, Anticarsia gemmatalis Hübner, and other soybean defoliators in field tests in Georgia, South Carolina, and Brazil. Single applications at rates as low as 75 g AI/ha afforded adequate initial and excellent residual control of A. gemmatalis and some suppression of low populations of Plusia spp. Two applications at higher rates gave significant control of soybean looper, Pseudoplusia includens (Walker), and showed promise against green cloverworm, Plathypena scabra (F.), and Mexican bean beetle, Epilachna varivestis Mulsant. Populations of geocorids and nabids were lower in 1 test, possibly because of insecticidal activity, scarcity of prey, or both

Response of Soybean Insects to Foliar Applications of a Chitin Synthesis Inhibitor TH 6040

The activity of TH 6040, a chitin synthesis inhibitor, was determined against velvetbean caterpillar, Anticarsia gemmatalis Hübner, and other soybean defoliators in field tests in Georgia, South Carolina, and Brazil. Single applications at rates as low as 75 g AI/ha afforded adequate initial and excellent residual control of A. gemmatalis and some suppression of low populations of Plusia spp. Two applications at higher rates gave significant control of soybean looper, Pseudoplusia includens (Walker), and showed promise against green cloverworm, Plathypena scabra (F.), and Mexican bean beetle, Epilachna varivestis Mulsant. Populations of geocorids and nabids were lower in 1 test, possibly because of insecticidal activity, scarcity of prey, or both

Including debris cover effects in a distributed model of glacier ablation

Distributed glacier melt models generally assume that the glacier surface consists of bare exposed ice and snow. In reality, many glaciers are wholly or partially covered in layers of debris that tend to suppress ablation rates. In this paper, an existing physically based point model for the ablation of debris-covered ice is incorporated in a distributed melt model and applied to Haut Glacier d’Arolla, Switzerland, which has three large patches of debris cover on its surface. The model is based on a 10 m resolution digital elevation model (DEM) of the area; each glacier pixel in the DEM is defined as either bare or debris-covered ice, and may be covered in snow that must be melted off before ice ablation is assumed to occur. Each debris-covered pixel is assigned a debris thickness value using probability distributions based on over 1000 manual thickness measurements. Locally observed meteorological data are used to run energy balance calculations in every pixel, using an approach suitable for snow, bare ice or debris-covered ice as appropriate. The use of the debris model significantly reduces the total ablation in the debris-covered areas, however the precise reduction is sensitive to the temperature extrapolation used in the model distribution because air near the debris surface tends to be slightly warmer than over bare ice. Overall results suggest that the debris patches, which cover 10% of the glacierized area, reduce total runoff from the glacierized part of the basin by up to 7%

Portable ozone calibration source independent of changes in temperature, pressure and humidity for research and regulatory applications

A highly portable ozone (O3) calibration source that can serve as a U.S. EPA level 4 transfer standard for the calibration of ozone analyzers is described and evaluated with respect to analytical figures of merit and effects of ambient pressure and humidity. Reproducible mixing ratios of ozone are produced by the photolysis of oxygen in O3-scrubbed ambient air by UV light at 184.9&thinsp;nm light from a low-pressure mercury lamp. By maintaining a constant volumetric flow rate (thus constant residence time within the photolysis chamber), the mixing ratio produced is independent of both pressure and temperature and can be varied by varying the lamp intensity. Pulse width modulation of the lamp with feedback from a photodiode monitoring the 253.7&thinsp;nm emission line is used to maintain target ozone mixing ratios in the range 30–1000&thinsp;ppb. In order to provide a constant ratio of intensities at 253.7 and 184.9&thinsp;nm, the photolysis chamber containing the lamp is regulated at a temperature of 40&thinsp;°C. The resulting O3 calibrator has a response time for step changes in output ozone mixing ratio of &lt;&thinsp;30&thinsp;s and precision (σp) of 0.4&thinsp;% of the output mixing ratio for 10&thinsp;s measurements (e.g., σp = ±0.4&thinsp;ppb for 100&thinsp;ppb of O3). Ambient humidity was found to affect the output mixing ratio of ozone primarily by dilution of the oxygen precursor. This potential humidity interference could be up to a few percent in extreme cases but is effectively removed by varying the lamp intensity to compensate for the reduced oxygen concentration based on feedback from a humidity sensor.</p

Methamphetamine Use and Emergency Department Utilization: 20 Years Later

Background. Methamphetamine (MAP) users present to the emergency department (ED) for myriad reasons, including trauma, chest pain, and psychosis. The purpose of this study is to determine how their prevalence, demographics, and resource utilization have changed. Methods. Retrospective review of MAP patients over 3 months in 2016. Demographics, mode of arrival, presenting complaints, disposition, and concomitant cocaine/ethanol use were compared to a 1996 study at the same ED. Results. 638 MAP-positive patients, 3,013 toxicology screens, and 20,203 ED visits represented an increase in prevalence compared to 1996: 461 MAP-positive patients, 3,102 screens, and 32,156 visits. MAP patients were older compared to the past. Mode of arrival was most frequently by ambulance but at a lower proportion than 1996, as was the proportion of MAP patients with positive cocaine toxicology screens and ethanol coingestion. Admission rate was lower compared to the past, as was discharge to jail. The proportion of MAP patients presenting with blunt trauma was lower compared to the past and higher for chest pain. Conclusion. A significant increase in the prevalence of MAP-positive patients was found. Differences in presenting complaints and resource utilization may reflect the shifting demographics of MAP users, as highlighted by an older patient population relative to the past

First direct measurements of formaldehyde flux via eddy covariance: implications for missing in-canopy formaldehyde sources

We report the first observations of formaldehyde (HCHO) flux measured via eddy covariance, as well as HCHO concentrations and gradients, as observed by the Madison Fiber Laser-Induced Fluorescence Instrument during the BEACHON-ROCS 2010 campaign in a rural, Ponderosa Pine forest northwest of Colorado Springs, CO. A median noon upward flux of ~80 &amp;mu;g m&lt;sup&gt;&amp;minus;2&lt;/sup&gt; h&lt;sup&gt;&amp;minus;1&lt;/sup&gt; (~24 ppt&lt;sub&gt;v&lt;/sub&gt; m s&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) was observed with a noon range of 37 to 131 &amp;mu;g m&lt;sup&gt;&amp;minus;2&lt;/sup&gt; h&lt;sup&gt;&amp;minus;1&lt;/sup&gt;. Enclosure experiments were performed to determine the HCHO branch (3.5 &amp;mu;g m&lt;sup&gt;-2&lt;/sup&gt; h&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) and soil (7.3 &amp;mu;g m&lt;sup&gt;&amp;minus;2&lt;/sup&gt; h&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) direct emission rates in the canopy. A zero-dimensional canopy box model, used to determine the apportionment of HCHO source and sink contributions to the flux, underpredicted the observed HCHO flux by a factor of 6. Simulated increases in concentrations of species similar to monoterpenes resulted in poor agreement with measurements, while simulated increases in direct HCHO emissions and/or concentrations of species similar to 2-methyl-3-buten-2-ol best improved model/measurement agreement. Given the typical diurnal variability of these BVOC emissions and direct HCHO emissions, this suggests that the source of the missing flux is a process with both a strong temperature and radiation dependence

Work characteristics and employee outcomes in local government

The overall objective of this study was to examine the work characteristics that make significant contributions to extra-role performance (as measured by the helping dimension of citizenship behaviour) and employee wellbeing (measured by job satisfaction and psychological health) in a local government. The work characteristics examined were based on the demand-control-support (DCS) model, augmented by organization-specific characteristics. The results indicate that characteristics described in the core DCS are just as relevant to extra-role performance as they are to more traditional indicators of job stress. Although the more situation-specific conditions were not predictive of citizenship behaviour, they made unique contributions to job satisfaction<br /

Missing peroxy radical sources within a summertime ponderosa pine forest

Organic peroxy (RO₂) and hydroperoxy (HO₂) radicals are key intermediates in the photochemical processes that generate ozone, secondary organic aerosol and reactive nitrogen reservoirs throughout the troposphere. In regions with ample biogenic hydrocarbons, the richness and complexity of peroxy radical chemistry presents a significant challenge to current-generation models, especially given the scarcity of measurements in such environments. We present peroxy radical observations acquired within a ponderosa pine forest during the summer 2010 Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H₂O, Organics and Nitrogen – Rocky Mountain Organic Carbon Study (BEACHON-ROCS). Total peroxy radical mixing ratios reach as high as 180 pptv (parts per trillion by volume) and are among the highest yet recorded. Using the comprehensive measurement suite to constrain a near-explicit 0-D box model, we investigate the sources, sinks and distribution of peroxy radicals below the forest canopy. The base chemical mechanism underestimates total peroxy radicals by as much as a factor of 3. Since primary reaction partners for peroxy radicals are either measured (NO) or underpredicted (HO₂ and RO₂, i.e., self-reaction), missing sources are the most likely explanation for this result. A close comparison of model output with observations reveals at least two distinct source signatures. The first missing source, characterized by a sharp midday maximum and a strong dependence on solar radiation, is consistent with photolytic production of HO₂. The diel profile of the second missing source peaks in the afternoon and suggests a process that generates RO₂ independently of sun-driven photochemistry, such as ozonolysis of reactive hydrocarbons. The maximum magnitudes of these missing sources (~120 and 50 pptv min⁻¹, respectively) are consistent with previous observations alluding to unexpectedly intense oxidation within forests. We conclude that a similar mechanism may underlie many such observations

Comprehensive screening and quantification of veterinary drugs in milk using UPLC–ToF-MS

Ultra-performance liquid chromatography combined with time-of-flight mass spectrometry (UPLC–ToF-MS) has been used for screening and quantification of more than 100 veterinary drugs in milk. The veterinary drugs represent different classes including benzimidazoles, macrolides, penicillins, quinolones, sulphonamides, pyrimidines, tetracylines, nitroimidazoles, tranquillizers, ionophores, amphenicols and non-steroidal anti-inflammatory agents (NSAIDs). After protein precipitation, centrifugation and solid-phase extraction (SPE), the extracts were analysed by UPLC–ToF-MS. From the acquired full scan data the drug-specific ions were extracted for construction of the chromatograms and evaluation of the results. The analytical method was validated according to the EU guidelines (2002/657/EC) for a quantitative screening method. At the concentration level of interest (MRL level) the results for repeatability (%RSD < 20% for 86% of the compounds), reproducibility (%RSD < 40% for 96% of the compounds) and the accuracy (80–120% for 88% of the compounds) were satisfactory. Evaluation of the CCβ values and the linearity results demonstrates that the developed method shows adequate sensitivity and linearity to provide quantitative results. Furthermore, the method is accurate enough to differentiate between suspected and negative samples or drug concentrations below or above the MRL. A set of 100 samples of raw milk were screened for residues. No suspected (positive) results were obtained except for the included blind reference sample containing sulphamethazine (88 μg/l) that tested positive for this compound. UPLC–ToF-MS combines high resolution for both LC and MS with high mass accuracy which is very powerful for the multi-compound analysis of veterinary drugs. The technique seems to be powerful enough for the analysis of not only veterinary drugs but also organic contaminants like pesticides, mycotoxins and plant toxins in one single method