Mobile measurement of vehicle emission factors in a roadway tunnel: A concentration gradient approach

Tunnels are the preferred experimental environments for estimating vehicle emission factors (EFs) under real-world driving conditions. In this study, online measurements of traffic-related air pollutants (including CO₂, NO_X, SO₂, O₃, particulate matter [PM], and volatile organic compounds [VOCs]) were conducted using a mobile laboratory in the Sujungsan Tunnel in Busan, Korea. Mobile measurements generated concentration profiles of the target exhaust emissions inside the tunnel. These data were used to produce a zonation of the tunnel, i.e., mixing and accumulation zones. There were differences between the CO₂, SO₂, and NO_X profiles, and a starting point that was free from ambient air mixing effects could be set at 600 m from the tunnel entrance. The EFs of vehicle exhaust emissions were calculated using pollutant concentration gradients. The average EFs for CO₂, NO, NO₂, SO₂, PM₁₀, PM_2.5, and ∑VOCs were 149,000, 380, 55, 29.2, 9.64, 4.33, and 16.7 mg km^-1·veh^-1, respectively. Among the VOC groups, alkanes contributed more than 70% of the VOC EF. Mobile measurement-derived EFs were validated using the conventional EFs from stationary measurements. The EF results from the mobile measurements matched those from the stationary measurements, while the absolute concentration differences between them implied complex aerodynamic movements of the target pollutants inside the tunnel. This study demonstrated the usefulness and advantages of applying mobile measurements in a tunnel environment and indicated the potential of the approach for observation-based policymaking.

Emissions from ships' activities in the anchorage zone: A potential source of sub-micron aerosols in port areas

Busan Port is among the world's top ten most air-polluted ports, but the role of the anchorage zone as a significant contributor to pollution has not been studied. To assess the emission characteristics of sub-micron aerosols, a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed in Busan, South Korea from September 10 to October 6, 2020. The concentration of all AMS-identified species and black carbon were highest when the winds came from the anchorage zone (11.9 µg·m^-3) and lowest with winds from the open ocean (6.64 µg·m^-3). The positive matrix factorization model identified one hydrocarbon-like organic aerosol (HOA) and two oxygenated organic aerosol (OOA) sources. HOAs were highest with winds from Busan Port, while oxidized OOAs were predominant with winds from the anchorage zone (less oxidized) and the open ocean (more oxidized). We calculated the emissions from the anchorage zone using ship activity data and compared them to the total emissions from Busan Port. Our results suggest that emissions from ship activities in the anchorage zone should be considered a significant source of pollution in the Busan Port area, especially given the substantial contributions of gaseous emissions (NOx: 8.78%; volatile organic compounds: 7.52%) and their oxidized moieties as secondary aerosols.

Beyond image defined risk factors (IDRFs): a delphi survey highlighting definition of the surgical complexity index (SCI) in neuroblastoma

PURPOSE

Preoperative evaluation of Image Defined Risk Factors (IDRFs) in neuroblastoma (NB) is crucial for determining suitability for upfront resection or tumor biopsy. IDRFs do not all carry the same weighting in predicting tumor complexity and surgical risk. In this study we aimed to assess and categorize a surgical complexity (Surgical Complexity Index, SCI) in NB resection.

METHODS

A panel of 15 surgeons was involved in an electronic Delphi consensus survey to identify and score a set of shared items predictive and/or indicative of surgical complexity, including the number of preoperative IDRFs. A shared agreement included the achievement of at least 75% consensus focused on a single or two close risk categories.

RESULTS

After 3 Delphi rounds, agreement was established on 25/27 items (92.6%). A severity score was established for each item ranging from 0 to 3 with an overall SCI range varying from a minimum score of zero to a maximum score of 29 points for any given patient.

CONCLUSIONS

A consensus on a SCI to stratify the risks related to neuroblastoma tumor resection was established by the panel experts. This index will now be deployed to critically assign a better severity score to IDRFs involved in NB surgery.

Capillary flow velocity profile analysis on paper-based microfluidic chips for screening oil types using machine learning

We conceived a novel approach to screen oil types on a wax-printed paper-based microfluidic platform. Various oil samples spontaneously flowed through a micrometer-scale channel via capillary action while their components were filtered and partitioned. The resulting capillary flow velocity profile fluctuated during the flow, which was used to screen oil types. Raspberry Pi camera captured the video clips, and a custom Python code analyzed them to obtain the capillary flow velocity profiles. 106 velocity profiles (each with 125 frames for 5 s) were recorded from various oil samples to build a training database. Principal component analysis (PCA), support vector machine (SVM), and linear discriminant analysis (LDA) were used to classify the oil types into heavy-to-medium crude, light crude, marine fuel, lubricant, and diesel oils. The second-order polynomial SVM model with PCA as a pre-processing step showed the highest accuracy: 90% in classifying crude oils and 81% in classifying non-crude oils. The assay took less than 30 s from the sample to answer, with 5 s of the capillary action-driven flow. This simple and effective assay will allow rapid preliminary screening of oil types, enable early tracking, and reduce the number of suspect samples to be analyzed by laboratory fingerprinting analysis.

Chemical characterization of sub-micron aerosols over the East Sea (Sea of Japan)

Studies of the land-sea-air interactions of aerosol are scarce considering their significant role in global environmental changes. Here, we investigated potential sources of sub-micron aerosols over the East Sea (Sea of Japan), which is strongly influenced by continental and marine aerosols. A high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was used to measure the size-resolved chemical compositions of sub-micron aerosols during the period March 10-15, 2020. Concentrations of all AMS species, black carbon (BC), PM₁₀ (particulate matter <10 μm) and PM_2.5 (particulate matter <2.5 μm) were higher when cruising in industrialized coastal areas compared to the offshore region. A positive matrix factorization (PMF) model identified five distinct sources, i.e., hydrocarbon-like organic aerosol, semi-volatile and low-volatile oxygenated aerosols, methanesulfonic acid (MSA), and dimethyl sulfide (DMS; C₂H₆S) oxidation, which accounted for 5.98 %, 21.6 %, 28.3 %, 34.5 %, and 9.64 % of the total organic mass, respectively. The spatiotemporal variation of MSA, as well as the MSA to sulfate ratio (MSA:SO₄^2-) over the East Sea, was determined for the first time. The mass concentrations of MSA displayed a similar time series distribution pattern to those of DMS. The time series distributions of the MSA:SO₄^2- ratio displayed distinct differences, with higher ratios downwind of the ocean (0.216 ± 0.083 μg·m^-3) than land (0.089 ± 0.030 μg·m^-3). The growth of ultrafine particles (10-35 nm) was observed during two of the elevated MSA:SO₄^2- ratio events, suggesting a potential role of MSA in new particle formation.

Determination of anthropogenic organics in dichlomethane extracts of aerosol particulate matter collected from four different locations in China and Republic of Korea by GC-MS and FTICR-MS

In this study, the hypothesis that particulate matter in east of Korea peninsula would be significantly influenced by particulate matter originated from east of China was evaluated. To test the hypothesis, water-insoluble compounds in particulate matter samples collected from three different locations in Korea and one in China were characterized by atmospheric pressure photoionization (APPI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and gas chromatography mass spectrometry (GC-MS). Each sample was collected twice, in winter and in spring. The GC-MS data revealed the presence of high levels of polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]anthracene in the samples from Tianjin, China. The sample collected in the winter from Baengnyeong Island, which is the location in Korea that is geographically closest to the east coast of China was also rich in aromatic compounds. Meanwhile, the APPI FTICR-MS data showed that polycondensed PAHs and two- to four-ring PAHs with long alkyl chains were abundant in the winter samples from Tianjin and Baengnyeong Island which stems most likely from coal combustion in the eastern China. In contrast, nonaromatic compounds with a biogenic origin were mostly observed in samples collected from islands located in eastern (Ulleung Island) and southern (Jeju Island) Korea. A principal component analysis by FTICR-MS and GC-MS also showed that the samples from Tianjin and those collected from Baengnyeong Island in the winter are strongly associated with coal combustion, whereas the other samples are mainly influenced by vehicle emissions. Therefore, it is concluded that the atmosphere from east of China has significant influence over atmosphere in west of Korea peninsula.

Seawater contamination associated with in-water cleaning of ship hulls and the potential risk to the marine environment

In-water cleaning can clear-off foulants from ship hulls to prevent transportation of non-indigenous species and reduce hull friction and consequent fuel use. However, during cleaning, antifouling paint residues containing toxic substances can be released into the environment. To understand the potential risks of in-water hull cleaning, cleaning effluents were collected and analyzed for total suspended solid (TSS), particle size distribution, and metal concentrations. TSS concentrations were 97.3-249 mg/L, corresponding to release rates of 12.9-37.5 g/m² from the hull surface. Particles with sizes of ≥8 μm contributed 75-94% of the TSS. Average Cu and Zn concentrations in the effluents were 209 μg/L and 1510 μg/L, respectively, which were used for risk assessment in two port scenarios. Although the risks vary with the scale of the hull cleaning and the ports, in-water cleaning poses clear risks to marine environments, unless the effluents are recovered or treated before being released.

Development of a portable oil type classifier using laser-induced fluorescence spectrometer coupled with chemometrics

Due to the recurrent small spills, oil pollution along coastal regions is still a major environmental issue. Standardized oil fingerprinting techniques are useful for oil spill identifications, but time- and resource-consuming. There have been ongoing needs for simple yet rapid approach for field screening of oil spill. Laser induced fluorescence (LIF) technology can be incorporated into a spectrometer, and with the integration of chemometrics can be consolidated as a potentially useful portable oil type classification device. Using a LIF spectrometer, 775 oil spectra were calibrated into supervised classification models and validated with 162 oil spectra. Reliability of the device to accurately remove background emission from fluorescence spectra was verified. Prediction performance and model robustness were further validated by comparison between commonly used classification models such as partial least square discriminant analysis (PLS-DA) and support vector machine-discriminant analysis (SVM-DA). Robustness in both models were comparable with PLS-DA having a lower number of misclassification (PLS-DA: 5.50%, SVM-DA: 13.8%) while SVM-DA having a lower number of unassigned samples (PLS-DA: 10.9%; SVM-DA: 16 1.39%). This study explicitly demonstrated the development of a new convenient and handy device which can be used as part of the screening process for oil spill fingerprinting.

Selective use of Peptide Receptor Radionuclide Therapy following comparative imaging of Ga-68 DOTATATE PET/CT against I-131 MIBG scintigraphy in a small Asian cohort of Adult Neuroblastoma

Adult neuroblastoma (AN) is rare with an extremely poor prognosis. No standard therapy exists for this entity and treatment options are limited in recurrent or refractory disease. ¹³¹I-MIBG has been used in combination with myeloablative therapy before autologous bone marrow transplantation or in a salvage therapy setting. However, myelotoxicity is a dose-limiting factor in heavily pre-treated patients and response is not always sustained. Somatostatin receptor scintigraphy and theranostics with radiolabelled somatostatin receptor analogues are becoming more commonplace with the recognition of these receptors in over 90% of neuroblastoma cells. We describe three AN patients assessed for somatostatin receptor status and the novel use of ¹⁷⁷Lu-based peptide recep-tor radionuclide therapy (PRRT) in two of them and a literature review.

High-throughput screening of oil fingerprint using FT-IR coupled with chemometrics

An important element of the oil spill emergency response is the ability to rapidly identify the properties of oil spilled. Chemometrics provides large numbers of multivariate analysis tools that allow for more extensive use of data. Fourier transformed infrared spectroscopy coupled with classification and prediction models such as partial least square (PLS) and PLS-DA (discriminant analysis) allows the rapid identification of oil type and characteristics. By searching for the maximum covariance with the variables of interest, PLS allows the visualization of relations between samples and variables. The framework of this study is based on two main steps: The first is classification of oil and the second is prediction of physicochemical properties. Separated into four main categories: crude, light fuel, heavy fuel, and lubricant, spectrums of 92 oils were calibrated to predict the oil type and physicochemical properties of 26 oils. The predictability and robustness of the model was further validated using weathered oil. The classification and prediction models have accuracy of >95%. Most of the PLS models have root mean square error of calibration and prediction ranging from 0.10-3.07 and 0.3-2.8, respectively. External cross validations using weathered oils showed high prediction accuracy (relative standard deviations <5%). By increasing the number of oil type and samples, this approach is a promising method and can be included as part of the oil spill fingerprinting protocols.

Stability of mechanically and chemically dispersed oil: Effect of particle types on oil dispersion

Oil spill dispersant (OSD) application is one of the preferred cleanup options to cope with oil spills at sea. OSD, in principle, can enhance biodegradation of oil because of its effectiveness in producing relatively small droplets and dispersing them into the water column. Under turbulent conditions, suspended particulate matter (SPM) which are present naturally in the environment can interact with oil to form aggregates known as oil-SPM aggregates (OSA) which also enhances biodegradation of oil. Despite its high dispersion effectiveness, chemically dispersed oil (CDO) has a tendency to resurface with increasing time which decreases the biodegradation potential. Meanwhile, the presence of SPM prevents recoalescence of dispersed oil which can enhance stability of oil droplets. This study focused on the effects of SPM on the dispersion effectiveness and stability of mechanically dispersed oil (MDO) and CDO. Dispersion tests of MDO and CDO extended to 72 h with and without SPM to see the initial effectiveness and the prolonged stability of dispersed oil. In the presence of SPM, the oil dispersed by MDO increased by 14.8-40.7%, while the resurfacing oil by CDO decreased by 8.7-19.4%. Regardless of SPM type, oil dispersion effectiveness and stability of MDO and CDO were significantly increased. Long-term stability test for 3 months showed that stability of OSA increased as the particle size decreased and particle counts increased.

Liquid Chromatographic Determination of Nicarbazin in Feeds and Premixes

A liquid chromatographic (LC) method has been developed for the determination of nicarbazin in premixes and poultry feed. Liquid chromatography of the 4,4'-dinitrocarbanilide (DNC) portion of nicarbazin is performed isocratically with a reverse phase octadecylsilica column and a UV detector set at 340 nm. The 2-hydroxy-4,6-dimethylpyrimidine (HDP) portion of nicarbazin is chromatographed isocratically with a reverse phase octylsilica column and a UV detector set at 305 nm. Nicarbazin concentration can be calculated by assaying both DNC and HDP, or by assaying DNC or HDP and assuming that nicarbazin is a 1:1 molar ratio of the two. Average recoveries of DNC and HDP added to poultry feed were 101% and 87%, respectively. This procedure provides an alternative to existing colorimetric procedures for determining nicarbazin in premixes and poultry feeds.

Environmental significance of lubricant oil: A systematic study of photooxidation and its consequences

Lubricant (lube) oil discharge from ships has been widely considered as normal "operational consumption", but is now deemed to be oil pollution. Despite the chronic contamination of the marine environment by lube oil, the number of studies related to its environmental impact, characteristics, and toxicity is limited. This study is the first attempt to investigate the environmental fate of lube oil subjected to photooxidation using in situ mesocosms. A tiered approach using thin-layer chromatography-flame ionization detection (TLC-FID), Fourier-transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) demonstrated compositional changes in lube oil and the water-soluble fraction (WSF). Total polycyclic aromatic hydrocarbons (ΣPAHs) in lube oil after 96 h of photooxidation were measured at 79.8 and 41 μg/g in the control (Con) and exposure (Exp) groups, respectively. Meanwhile, the ΣPAHs concentration in WSF after 96 h was very low, at 0.25 and 0.45 μg/L in Con and Exp, respectively. FTIR and GC-MS helped identify bond changes and photoproducts in WSF. A wide range of photoproducts, including carboxylic acids, esters, anhydrides, aldehydes and ketones, were identified in WSF. Toxic effects of WSF in both the Con and Exp groups obtained after 96 h of photooxidation were evaluated on olive flounder (Paralichthys olivaceus) embryos. Morphological defects, especially tail fin fold defects, were found to be significantly elevated in both the Con and Exp groups, with marginally higher frequency in Exp. The results of this study demonstrate the need for further research on lube oil weathering, including monitoring over prolonged periods of time.

Suspended particles enhance biodegradation of oil in sea

Biodegradation patterns of oil in four distinct phases were compared over a 14-day series of exposures. The dispersibility and stability of oil droplets in the water column were important factors affecting oil biodegradation. Due to the stability of oil droplets with particle interactions, oil-suspended particulate matter aggregates (OSA) showed a five-fold enhancement in biodegradation compared to non-dispersed oil. The reduction of total petroleum hydrocarbons was highest in OSA (51.45%), followed by chemically dispersed oil (33.5%), oil film (21.6%), and water-accommodated fractions (WAF, 14.3%). Polycyclic aromatic hydrocarbon (PAH) profiles and percentage weathering plots showed that reductions in PAHs in WAF, oil film, and chemically dispersed oil were mainly due to evaporation (41.5-69.5%) and only partially due to biodegradation (7.4-16.3%). However, the reduction of PAHs in OSA was driven more by biodegradation (36.8%) than evaporation (29.7%). The strong PAH-particle interactions in OSA inhibited evaporation of PAHs and enhanced microorganism biodegradation in the water column.

A systematic study of the effects of solvents on phenanthrene photooxidation

A systematic study of the photooxidation of phenanthrene under simulated environmental conditions was conducted in vitro using polar (methanol, acetonitrile) and non-polar (isooctane, hexane) solvents as media. In all solvents, phenanthrene concentration decreased exponentially as exposure time increased. Fourier-transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) analysis were used to investigate the structural changes induced by photooxidation. After 24 h of photooxidation, FTIR showed the formation of characteristic bands of carboxylic acid in all solvents. In non-polar solvents, characteristic phenanthrene peaks were completely depleted after 48 h. In polar solvents, phenanthrene peaks disappeared at a slower rate, with peaks in acetonitrile disappearing at 72 h and methanol persisting at trace levels at 96 h. The reaction rate was higher in non-polar solvents. The obtained half-lives were observed in the following order: isooctane (13.2 h) > hexane (13.5 h) > methanol (18.0 h) > acetonitrile (22.8 h). FTIR and GC-MS results were in good agreement and showed the formation of carboxylic acids, aldehydes, and ketones in polar solvents and carboxylic acids, alkanes, and alkanoic acids in non-polar solvents. Products such as primary amides induced by solvent effects were observed in acetonitrile. Based on the results, the solvents were rated and a solvent selection guide for photooxidation of PAHs was provided.

Fate of residual oils during remediation activities after the Wu Yi San oil spill

In this study, the fate of residual oils was investigated during remediation activities for a year after the Wu Yi San oil spill. Microscope observations showed that relatively large amounts of oil-suspended particulate matter aggregate (OSA) were formed. Negatively buoyant OSA was the dominant form (>95%), followed by neutrally (~5%) and positively buoyant (<1%) forms. To elucidate the dominance of negative buoyancy OSA, physicochemical properties of the mineral and residual oils were identified. Chemical analysis showed that the weathering percentage of residual oils was 43.7 ± 2.59%, which was the driving factor for sedimentation of OSA. As the density of oil increased with weathering stages, the density of OSA also increased simultaneously. These results showed that, during mechanical remediation activities, resurfaced residual oils can form negative buoyancy OSA which tends to sink and transfers oil contaminants from intertidal to benthic environments.

A preliminary study on the role of suspended particulate matter in the bioavailability of oil-derived polycyclic aromatic hydrocarbons to oysters

Suspended particulate matter (SPM) refers to fine-grained materials that are suspended in water columns. By providing a surface for the adsorption of non-polar organic compounds, SPM is a carrier for persistent and toxic contaminants. A wide range of organic pollutants, including polycyclic aromatic hydrocarbons (PAHs), can be adsorbed onto SPM. The formation of particle-associated PAHs can sequentially increase the potential for exposure to and bioaccumulation by organisms. Until recently, most oil exposure studies were performed using freely dissolved and dispersed forms, and therefore the role of SPM in influencing the bioavailability and bioaccumulation of PAHs has not been considered. This study found that SPM influences the bioavailability of petrogenic PAHs in the water column and their potential for accumulation in oysters. SPM significantly enhanced the water column entrainment of petrogenic PAHs, thus increasing the potentials for uptake by exposed organisms. PAHs in the water column was highest from mechanically dispersed oil (MDO; 2.27 μg/mL) ≥ oil-SPM aggregate (OSA; 1.96 μg/mL) > water accommodated fraction (WAF; 0.19 μg/mL) but the percentage of PAHs accumulated in oysters were highest from WAF (18.3%) > MDO (14.2%) > OSA (9.62%). Despite the high water column available PAHs, oysters exposed to SPM-associated oil accumulated PAHs at half the accumulation efficiency compared with those exposed to PAHs without SPM.

Contamination and Human Health Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Oysters After the Wu Yi San Oil Spill in Korea

After the collision of the Singapore-registered oil tanker M/V Wu Yi San into the oil terminal of Yeosu, Korea on January 31, 2014, approximately 900 m³ of oil and oil mixture were released from the ruptured pipelines. The oil affected more than 10 km of coastline along Gwangyang Bay. Emergency oil spill responses recovered bulk oil at sea and cleaned up the stranded oil on shore. As part of an emergency environmental impact assessment, region-wide monitoring of oil contamination in oyster had been conducted for 2 months. Highly elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) were detected at most of the spill affected sites. Four days after the spill, the levels of PAHs in oysters increased dramatically to 627-81,000 ng/g, the average of which was 20 times higher than those found before the spill (321-4040 ng/g). The level of PAHs in these oysters increased until 10 days after the spill and then decreased. Due to the strong tidal current and easterly winter winds, the eastern part of the Bay-the Namhae region-was heavily contaminated compared with other regions. The accumulation and depuration of spilled oil in oyster corresponded with the duration and intensity of the cleanup activities, which is the first field observation in oil spill cases. Human health risk assessments showed that benzo[a]pyrene equivalent concentrations exceeded levels of concern in the highly contaminated sites, even 60 days after the spill.

[What do medical students think of family medicine? Results of an online cross-sectional study in the federal state of Baden-Wuerttemberg]

BACKGROUND

In the context of physician shortages, critical factors influencing career choice need to be better understood. The aim of this study was to explore experiences students have had with family medicine in order to develop additional strategies for recruiting family medicine trainees.

METHODS

Students from the five medical faculties in the federal state of Baden-Wuerttemberg were invited to participate in an online-survey via email. A purpose-built questionnaire was used. In addition to descriptive statistics, analysis included linear partial correlations controlled for age, gender, and semester, which were calculated between the variable "I believe family medicine is an attractive job" and the 31 variables of the survey. Linear regression was used to analyze the influence of experiences with family medicine and statements about family medicine to the perception of family medicine as an attractive specialty.

RESULTS

1299 students participated in the survey. About half of the participants (49.7 %) considered working as a primary care physician to be attractive or partly attractive. 49.6 % of students reported positive experiences with family medicine as a patient and 33.1 % as a family member. 24.3 % reported positive experiences during the compulsory 1-2 weeks general practice internship and 18.1 % during a four weeks elective placement. For 302 participants (23.3 %), family medicine is presented positively in the media. 178 (13.7 %) consider family medicine to have high importance in both undergraduate and postgraduate education. Positive influences on judging attractiveness of family medicine were: own experience with family medicine as a clinical elective (rpart= + 0.450), own experience with family medicine as a patient (rpart= + 0.218), perception that family medicine offers a diversified working day (rpart= + 0.259), and perception that family medicine offers a good salary (rpart= + 0.242).

CONCLUSION

To enable students during undergraduate studies to have practical experience with family medicine seems to be an important influence on judging family medicine attractive.

Delayed diagnosis of pseudoaneurysm formation in a patient with diaphyseal aclasis

A 15 year old boy, with known diaphyseal aclasis, presented with a swollen left leg. The diagnosis of popliteal pseudoaneurysm, a known and well understood vascular complication, was delayed due to presentation suggestive of a chondrosarcoma. In this age group, sarcomatous change is more common and a potentially sinister complication of diaphyseal aclasis. Following a sarcoma MDT referral, the correct diagnosis was confirmed by ultrasound and CT angiogram. This case identifies one of the largest, non-ruptured popliteal pseudoaneurysms reported and illustrates an unusual complication of a rare orthopaedic genetic condition, which is potentially limb threatening.

Swelling in the upper arm: the presentation and management of an isolated brachial artery aneurysm

True aneurysms of the brachial artery are uncommon. We describe the presentation and surgical management of an isolated, brachial artery aneurysm in a 64-year-old woman. Excision of the aneurysm and long saphenous venous interposition grafting was performed with no postoperative complications and histology demonstrated true aneurysmal degeneration.

[Development, factor-analytical control and psychometric evaluation of a questionnaire on specialty choices among medical students]

AIM OF THE STUDY

A questionnaire was developed and validated which assesses factors influencing career choices of medical students and their perception of possibilities in general practice.

METHODS

The first questionnaire version, which was developed based on a systematic literature review, was checked for comprehensibility and redundancy using concurrent think aloud. The revised version was filled out by a pilot sample of medical students and the factor structure was assessed using principal component analysis (PCA). The final version was filled out in an online survey by medical students of all 5 Medical Faculties in the federal state of Baden-Wuerttemberg. The factor structure was validated with a confirmatory factor analysis (CFA). Reliability was assessed as internal consistency using Cronbach's α.

RESULTS

The questionnaire comprises 2 parts: ratings of (A) the individual importance and of (B) the possibilities in general practice on 5-point scales. The first version comprising 118 items was shortened to 63 items after conducting interviews using concurrent think aloud. A further 3 items giving no information were removed after piloting the questionnaire on 179 students. The 27 items of part A were structured in 7 factors (PCA): image, personal ambition, patient orientation, work-life balance, future perspectives, job-related ambition, and variety in job. This structure had a critical fit in the CFA applied to the final version filled out by 1 299 students. Internal consistency of the factors was satisfactory to very good (Cronbach's α=0.55-0.81).

CONCLUSION

The questionnaire showed good psychometric properties. Further, not assessed factors influence career choice resulting in unexplained variance in our dataset and the critical fit of the model.

Personalizing mammography by breast density and other risk factors for breast cancer: analysis of health benefits and cost-effectiveness

BACKGROUND

Current guidelines recommend mammography every 1 or 2 years starting at age 40 or 50 years, regardless of individual risk for breast cancer.

OBJECTIVE

To estimate the cost-effectiveness of mammography by age, breast density, history of breast biopsy, family history of breast cancer, and screening interval.

DESIGN

Markov microsimulation model.

DATA SOURCES

Surveillance, Epidemiology, and End Results program, Breast Cancer Surveillance Consortium, and the medical literature.

TARGET POPULATION

U.S. women aged 40 to 49, 50 to 59, 60 to 69, and 70 to 79 years with initial mammography at age 40 years and breast density of Breast Imaging Reporting and Data System (BI-RADS) categories 1 to 4.

TIME HORIZON

Lifetime.

PERSPECTIVE

National health payer.

INTERVENTION

Mammography annually, biennially, or every 3 to 4 years or no mammography.

OUTCOME MEASURES

Costs per quality-adjusted life-year (QALY) gained and number of women screened over 10 years to prevent 1 death from breast cancer.

RESULTS OF BASE-CASE ANALYSIS

Biennial mammography cost less than $100,000 per QALY gained for women aged 40 to 79 years with BI-RADS category 3 or 4 breast density or aged 50 to 69 years with category 2 density; women aged 60 to 79 years with category 1 density and either a family history of breast cancer or a previous breast biopsy; and all women aged 40 to 79 years with both a family history of breast cancer and a previous breast biopsy, regardless of breast density. Biennial mammography cost less than $50,000 per QALY gained for women aged 40 to 49 years with category 3 or 4 breast density and either a previous breast biopsy or a family history of breast cancer. Annual mammography was not cost-effective for any group, regardless of age or breast density.

RESULTS OF SENSITIVITY ANALYSIS

Mammography is expensive if the disutility of false-positive mammography results and the costs of detecting nonprogressive and nonlethal invasive cancer are considered.

LIMITATION

Results are not applicable to carriers of BRCA1 or BRCA2 mutations.

CONCLUSION

Mammography screening should be personalized on the basis of a woman's age, breast density, history of breast biopsy, family history of breast cancer, and beliefs about the potential benefit and harms of screening.

PRIMARY FUNDING SOURCE

Eli Lilly, Da Costa Family Foundation for Research in Breast Cancer Prevention of the California Pacific Medical Center, and Breast Cancer Surveillance Consortium.

[Aspirations of medical students: "planning for a secure career" - results of an online-survey among students at five medical schools in Germany]

BACKGROUND

In times of shortage of doctors, expectations and interests of the future generation of doctors towards their career aspiration is of major importance. The aim of this study was to analyze expectations of medical students at the five medical schools in the State of Baden-Wuerttemberg (Germany) concerning their career choice and factors influencing it.

METHODS

Between January and February 2010, 1299 medical students (out of 12 062 medical students at the five medical schools) participated in an online-survey. In addition to sociodemographic items, career choice and aspects of planning reliability were raised.

RESULTS

Three quarters of the students assign a medical profession for their future occupation. There is a dominance of internal medicine (n = 152), gynaecology (n = 127), paediatrics (n = 125), surgery (n = 115), anaesthesiology (n = 101), and family medicine (n = 88). The time point of decision varies between the different undergraduate years of medical school and specialty. Students at the beginning of their studies seem to be interested mostly in surgery. During medical school the interests towards internal medicine grows. Regarding planning dependability important aspects for medical students were to work in a job that has a future (61.2 % fully agree), to have a safe job (57.7 %), and to have a safe income (57.1 %). Less important seems to be to have good opportunity to earn money (29.6 %).

CONCLUSIONS

Interest in a certain specialty changes markedly at during medical school. Factors such as economical guarantee, good future prospects and also the studies itself have an essential impact for students on choosing a specific career. Strategies to face physicians' shortage in different specialties need to be close to the needs and expectations of future physicians. This is not only valid for the undergraduate time period but also for the work circumstances of their future.

Abstract B18: Personalizing the frequency of mammography: Cost effectiveness of screening mammography for women age 40 to 80 by breast density and other risk factors

Background: Current guidelines recommend mammography starting at age 40 or 50 years regardless of individual risk of breast cancer and do not take into account a woman's risk of breast cancer or breast density.

Methods: We used Markov microsimulation models to estimate the most cost-effectiveness intervals for screening mammography. Data about Breast Imaging Reporting and Data System (Bi-Rads) breast density, age, risk factors and risk of breast cancer, the natural history of breast cancer, estimates of progression in stages of breast cancer between mammograms, the cost of mammograms and medical care for breast cancer came from the Surveillance Epidemiology and End Results program, Breast Cancer Surveillance Consortium, and the medical literature. Simulations were done for cohorts receiving subsequent mammography between ages 40 to 79 years. We considered a strategy to be cost-effective if it cost ≤ $100,000 per lifetime quality adjusted life year (QALY) gained.

Results: Between ages 50 to 79, mammography every 2 years is cost-effective (&lt;$100,000 per QALY) for women with Bi-Rads-3 or −4 breast density, or with BI-RADS 1 or 2 and a family history of breast cancer or history of breast biopsy. Mammography is cost-effective if done less often -every 3 or 4 years — for women with lower (Bi-Rads-1 or −2) breast density and no family history of breast cancer or history of breast biopsy. For women age 40-49, mammography every 2 years is cost-effective for those with Bi-Rads-3 or −4 breast density plus a family history of breast cancer and/or a history of breast biopsy, but it is not cost-effective for 40 to 49 year olds without these risk factors and with lower breast density. In general, the most cost-effective screening interval is longer if false positive results cause a loss of quality of life.

Conclusions: The frequency of mammography should be personalized based on woman's risk of breast cancer, estimated from her age, breast density, family history of breast cancer, history of breast biopsy and the potential effect of false positive mammograms on her quality of life.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):B18.

Empiric antimicrobial therapy for pediatric skin and soft-tissue infections in the era of methicillin-resistant Staphylococcus aureus

OBJECTIVE

The goal was to compare the clinical effectiveness of monotherapy with beta-lactams, clindamycin, or trimethoprim-sulfamethoxazole in the outpatient management of nondrained noncultured skin and soft-tissue infections (SSTIs), in a methicillin-resistant Staphylococcus aureus (MRSA)-endemic region.

METHODS

A retrospective, nested, case-control trial was conducted with a cohort of patients from 5 urban pediatric practices in a community-acquired MRSA-endemic region. All subjects were treated as outpatients with oral monotherapy for nondrained noncultured SSTIs between January 2004 and March 2007. The primary outcome was treatment failure, defined as a drainage procedure, hospitalization, change in antibiotic, or second antibiotic prescription within 28 days.

RESULTS

Of 2096 children with nondrained noncultured SSTIs, 104 (5.0%) were identified as experiencing treatment failure and were matched to 480 control subjects. Compared with beta-lactam therapy, clindamycin was equally effective but trimethoprim-sulfamethoxazole was associated with an increased risk of failure. Other factors independently associated with failure included initial treatment in the emergency department, presence or history of fever, and presence of either induration or a small abscess.

CONCLUSIONS

Compared with beta-lactams, clindamycin monotherapy conferred no benefit, whereas trimethoprim-sulfamethoxazole was associated with an increased risk of treatment failure in a cohort of children with nondrained noncultured SSTIs who were treated as outpatients. Even in regions with endemic community-acquired MRSA, beta-lactams may still be appropriate, first-line, empiric therapy for children presenting with these infections.

[Foundations of shared decision making and examples of its application in rehabilitation]

Enhanced patient participation in health care is demanded due to better knowledge of patients about diseases and their treatment, due to more treatment strategies in the course of scientific progress, due to ethical and legal considerations, and due to study results. With shared decision-making (SDM) a method was defined for the medical interview to involve patients in treatment decisions. Process steps for orientation are available for the procedure of the medical encounter. Transfer of shared decision-making into health care can be realized through three strategies, i. e., by physician training to enhance physicians' competencies in medical encounter, by decision aids for better information and preparation for decision making, and by patient education. For examination and fostering of SDM in German health care the German Ministry of Health initiated a research consortium in the years 2001 to 2007 called "Patient as a partner in medical decision making". In an additional research consortium of the German Ministry of Education and Research, the German Pension Insurance scheme as well as the associations of statutory and private health insurance, various projects for health services research on the subject of "Chronic Diseases and Patient Orientation" will be funded starting in 2008. This initiative with a focus on rehabilitation will foster studies about need-specific patient information, training programmes for chronically ill patients, and about the organisation of a more participative structure of health care delivery.

Achieving blood pressure goals globally: five core actions for health-care professionals. A worldwide call to action

The prevalence of hypertension continues to rise across the world, and most patients who receive medical intervention are not adequately treated to goal. A Working Group including representatives of nine international health-care organizations was convened to review the barriers to more effective blood pressure control and propose actions to address them. The group concluded that tackling the global challenge of hypertension will require partnerships among multiple constituencies, including patients, health-care professionals, industry, media, health-care educators, health planners and governments. Additionally, health-care professionals will need to act locally with renewed impetus to improve blood pressure goal rates. The Working Group identified five core actions, which should be rigorously implemented by practitioners and targeted by health systems throughout the world: (1) detect and prevent high blood pressure; (2) assess total cardiovascular risk; (3) form an active partnership with the patient; (4) treat hypertension to goal and (5) create a supportive environment. These actions should be pursued with vigour in accordance with current clinical guidelines, with the details of implementation adapted to the economic and cultural setting.

[Effects of a shared decision making model in psychiatric and neurologic practice]

Involving patients in medical decisions is increasingly being advocated in medical fields other than psychiatry and neurology. A model of shared decision making might prove to be an ideal way of bridging the gap between patient-centred and evidence-based medicine. This report provides a survey of this shared decision making model and a discussion of its implications in the fields of mental health and neurology.

Development and first validation of the shared decision-making questionnaire (SDM-Q)

OBJECTIVE

Due to a lack of valid German instruments measuring shared decision-making (SDM), a theory-driven questionnaire (SDM-Q) to measure the process of SDM was developed and validated.

METHODS

As a theoretical basis steps of the SDM process were defined in an expert panel. Item formulation was then conducted according to the Delphi method. For the first validation on a mixed sample Rasch analysis was used to eliminate items not fitting the construct thus receiving a unidimensional scale.

RESULTS

After eliminating 4 items the remaining 11 form a unidimensional scale with an acceptable reliability for person measures (0.77) and very good reliability for item difficulties (0.95). Analysis of subgroups revealed a different use of items in different conditions. Furthermore the scale showed high ceiling effects.

CONCLUSION

A new theory-driven instrument to measure the process of SDM has been developed and validated by use of a rigorous method revealing first promising results. Yet the ceiling effects require the addition of more discriminating items, and the different use of items in different conditions demands an in depth analysis.

PRACTICE IMPLICATIONS

While the concept of SDM is constantly receiving more attention in medical practice, its valid and reliable measurement remains challenging.

Spontaneously arising superficial temporal artery aneurysms: a report of two cases and review of the literature

The majority of superficial temporal artery (STA) aneurysms are due to trauma and are, in reality, false aneurysms. However, true STA aneurysms are extremely rare. Here, we present two cases of spontaneous superficial temporal artery aneurysms arising without any previous history of trauma.

A New Approach: Regional Nerve Blockade for Angioplasty of the Lower Limb

PURPOSE

An audit study investigated the pilot use of regional nerve block analgesia (as an alternative to sedative/opiate, general or central neuraxial anesthesia) performed by radiologists with the assistance of imaging techniques during complex prolonged angiography.

METHODS

Radiologists were trained by anesthetic consultants to administer and use lower limb peripheral nerve block for difficult prolonged angioplasty procedures for patients with severe lower limb rest pain who were unable to lie in the supine position. In a pilot study 25 patients with limb-threatening ischemia received sciatic and femoral nerve blockade for angioplasty. The technique was developed and perfected in 12 patients and in a subsequent 13 patients the details of the angiography procedures, peripheral anesthesia, supplementary analgesia, complications, and pain assessment scores were recorded. Pain scores were also recorded in 11 patients prior to epidural/spinal anesthesia for critical ischemic leg angioplasty.

RESULTS

All patients with peripheral nerve blockade experienced a reduction in their ischemic rest pain to a level that permitted angioplasty techniques to be performed without spinal, epidural or general analgesia. In patients undergoing complex angioplasty intervention, the mean pain score by visual analogue scale was 3.7, out of a maximum score of 10.

CONCLUSIONS

The successful use of peripheral nerve blocks was safe and effective as an alternative to sedative/opiate, epidural or general anesthesia in patients undergoing complex angiography and has optimized the use of radiological and anesthetic department resources. This has permitted the frequent radiological treatment of patients with limb-threatening ischemia and reduced delays caused by the difficulty in enlisting the help of anesthetists, often at short notice, from the busy operating lists.

[Development and validation of assessment instruments for shared decision making]

The German Ministry for Health and Social Security is funding ten projects to introduce shared decision making into clinical practice. The medical problems the projects are focussing on were chosen from among various diseases (e. g. depression, multiple sclerosis, cancer). The ten projects achieved consensus on a core set of instruments for the measurement of process and outcome of the shared decision making. Instruments developed in German-speaking countries are currently not available. Thus, linguistic and cultural validation had to be performed for the core set instruments. The results of the data analysis as well as patient interviews demonstrate the need for improving these instruments. Therefore, the members of the methodological working group concentrated on the integration of these results in a new instrument. In a first step the construct of "shared decision making" was defined, followed by a definition of the process elements characterising shared decision making. Thereafter, items were developed on the basis of the process elements. The new instrument will now be validated for different diseases.

Entwicklung und Evaluation eines Fortbildungsprogramms zur Partizipativen Entscheidungsfindung f�r die haus�rztliche Versorgung depressiver Patienten

Patient surveys show that many patients want broad information about their disease and treatment. Often they are interested to participate in the process of medical decision making, which could be realised with the concept of shared decision making where patient's values and needs are considered to the same extent as the treatment recommendations of evidence-based medicine. In depression care, it has been demonstrated so far that the active involvement of patients contributes to higher motivation for treatment. For enhancing patient's acceptance and motivation to avail themselves of medical treatment, a training program for general practitioners was developed and evaluated. It was the aim of the training to involve depressive patients in medical decision making. The training consists of depression-specific components (e. g. diagnosis, patient information, therapy) and general components (communication and shared decision making). The training was carried out in five sessions within a 6-month period (May to October 2003) embracing 20 h of training. Participants were 20 general practitioners in Southwest Germany. Physician's satisfaction with the training program is high. Especially in the fields of diagnosis and shared decision making the physicians clearly benefited. Transfer of shared decision making into daily routine was assessed as possible by the large majority of the trainees. Application of the training concept to other diseases and evaluation on the basis of daily routine is recommended. The training effects on medical care are presently being assessed in a randomised controlled trial.

Fr�h- und Basisintervention bei Patienten mit schizophrenen St�rungen

THEORETICAL BACKGROUND

Of all outpatients with a diagnosis of schizophrenia, 30-40% refuse a psychiatrist's care. For this group of patients the general practitioner holds a key position for such different tasks as detection of prodromal schizophrenia or early warning signs of relapse and identification of risk variables for deteriorating outcome, gatekeeping (referral to specialists or other services), integration, and counseling of key relatives. Fifty percent of GPs are interested in disease-specific medical education programs.

STUDY DESIGN AND METHODS

A control trial examined the changes that participating GPs intended to make in three main topics of the curriculum: (1) changing attitudes (pessimistic outcome expectation, low self-esteem), (2) enhancement of detection skills (prodromal schizophrenia, early warning signs of relapse, and risk factors for poor social and vocational integration), and (3) enhancement of management skills (dosing schemes, motivational interviewing).

RESULTS

In the assessment 2 weeks after the training session, we found significant changes in favor of the trained group in detection and management skills and also improved self-confidence of GPs.

CONCLUSIONS

Problem-oriented and case-based learning strategies should be preferred to lectures in training programs for psychiatric skills in primary care.

Pharmacokinetic model of iodine-131-G250 antibody in renal cell carcinoma patients

A model that describes the pharmacokinetic distribution of 131I-labeled G250 antibody is developed.

METHODS

Previously collected pharmacokinetic data from a Phase I-II study of 131I-G250 murine antibody against renal cell carcinoma were used to develop a mathematical model describing antibody clearance from serum and the whole body. Survey meter measurements, obtained while the patient was under radiation precautions, and imaging data, obtained at later times, were combined to evaluate whole-body clearance kinetics over an extended period.

RESULTS

A linear two-compartment model was found to provide good fits to the data. The antibody was injected into Compartment 1, the initial distribution volume (Vd) of the antibody, which included serum. The antibody exchanged with the rest of the body, Compartment 2, and was eventually excreted. Data from 13 of the 16 patients fit the model with unique parameters; the maximum, median and minimum values for model-derived Vd were 6.3, 3.7 and 2.11, respectively. The maximum, median and minimum values for the excretion rate were 8 x 10(-2), 2.4 x 10(-2) and 1.3 x 10(-2) hr(-1), respectively. Parameter sensitivity analysis showed that a change in the transfer rate constant from serum to the rest of the body had the greatest effect on serum cumulative activity and that the rate constant for excretion had the greatest effect on whole-body cumulative activity.

CONCLUSION

A linear two-compartment model was adequate in describing the serum and whole-body kinetics of G250 antibody distribution. The median initial distribution volume predicted by the model was consistent with the nominal value of 3.81. A wide variability in fitted parameters was observed among patients, reflecting the differences in individual patient clearance and exchange kinetics of G250 antibody. By selecting median parameter values, such a model may be used to evaluate and design prolonged multiple administration radioimmunotherapy protocols.

Hypercoagulable states in patients with leg ischaemia

Hypercoagulable states are found in up to 10 per cent of patients with a history of unexplained venous thrombosis. To investigate the prevalence in arterial thrombosis, thrombophilia screening was performed on 124 patients who had previously undergone lower-limb revascularization, 45 claudicants and 27 controls. Of the patients who had undergone revascularization 40 per cent had a hypercoagulation abnormality (low levels of protein C, protein S and antithrombin III or presence of the lupus anticoagulant) in comparison with 27 per cent of claudicants and 11 per cent of controls (P < 0.01). Furthermore, patients who had suffered reocclusion after revascularization were significantly more likely to have a hypercoagulation abnormality than those who had not (P < 0.05), even if the occlusion had occurred more than 6 months previously. Lupus anticoagulant was the abnormality most frequently detected and, like low protein C levels, was found only in patients with peripheral vascular disease. It appears that hypercoagulable states are common in patients with arterial disease and may predispose to failure of revascularization.