17 research outputs found
Quasi-spherical ice in convective clouds
Homogeneous freezing of supercooled droplets occurs in convective systems in low and midlatitudes. This droplet-freezing process leads to the formation of a large amount of small ice particles, so-called frozen droplets, that are transported to the upper parts of anvil outflows, where they can influence the cloud radiative properties. However, the detailed microphysics and, thus, the scattering properties of these small ice particles are highly uncertain. Here, the link between the microphysical and optical properties of frozen droplets is investigated in cloud chamber experiments, where the frozen droplets were formed, grown, and sublimated under controlled conditions. It was found that frozen droplets developed a high degree of small-scale complexity after their initial formation and subsequent growth. During sublimation, the small-scale complexity disappeared, releasing a smooth and near-spherical ice particle. Angular light scattering and depolarization measurements confirmed that these sublimating frozen droplets scattered light similar to spherical particles: that is, they had angular light-scattering properties similar to water droplets. The knowledge gained from this laboratory study was applied to two case studies of aircraft measurements in midlatitude and tropical convective systems. The in situ aircraft measurements confirmed that the microphysics of frozen droplets is dependent on the humidity conditions they are exposed to (growth or sublimation). The existence of optically spherical frozen droplets can be important for the radiative properties of detraining convective outflows.Peer reviewe
Aerosol characteristics and particle production in the upper troposphere over the Amazon Basin
Airborne observations over the Amazon Basin showed high aerosol particle concentrations in the upper troposphere (UT) between 8 and 15 km altitude, with number densities (normalized to standard temperature and pressure) often exceeding those in the planetary boundary layer (PBL) by 1 or 2 orders of magnitude. The measurements were made during the German–Brazilian cooperative aircraft campaign ACRIDICON–CHUVA, where ACRIDICON stands for Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems and CHUVA is the acronym for Cloud Processes of the Main Precipitation Systems in Brazil: A Contribution to Cloud Resolving Modeling and to the GPM (global precipitation measurement), on the German High Altitude and Long Range Research Aircraft (HALO). The campaign took place in September–October 2014, with the objective of studying tropical deep convective clouds over the Amazon rainforest and their interactions with atmospheric trace gases, aerosol particles, and atmospheric radiation.
Aerosol enhancements were observed consistently on all flights during which the UT was probed, using several aerosol metrics, including condensation nuclei (CN) and cloud condensation nuclei (CCN) number concentrations and chemical species mass concentrations. The UT particles differed sharply in their chemical composition and size distribution from those in the PBL, ruling out convective transport of combustion-derived particles from the boundary layer (BL) as a source. The air in the immediate outflow of deep convective clouds was depleted of aerosol particles, whereas strongly enhanced number concentrations of small particles ( 90 nm) particles in the UT, which consisted mostly of organic matter and nitrate and were very effective CCN.
Our findings suggest a conceptual model, where production of new aerosol particles takes place in the continental UT from biogenic volatile organic material brought up by deep convection and converted to condensable species in the UT. Subsequently, downward mixing and transport of upper tropospheric aerosol can be a source of particles to the PBL, where they increase in size by the condensation of biogenic volatile organic compound (BVOC) oxidation products. This may be an important source of aerosol particles for the Amazonian PBL, where aerosol nucleation and new particle formation have not been observed. We propose that this may have been the dominant process supplying secondary aerosol particles in the pristine atmosphere, making clouds the dominant control of both removal and production of atmospheric particles
Quasi-spherical Ice in Convective Clouds
Homogeneous freezing of supercooled droplets occurs in convective systems in low and midlatitudes. This
droplet-freezing process leads to the formation of a large amount of small ice particles, so-called frozen
droplets, that are transported to the upper parts of anvil outflows, where they can influence the cloud radiative
properties. However, the detailed microphysics and, thus, the scattering properties of these small ice particles
are highly uncertain. Here, the link between the microphysical and optical properties of frozen droplets is
investigated in cloud chamber experiments, where the frozen droplets were formed, grown, and sublimated
under controlled conditions. It was found that frozen droplets developed a high degree of small-scale complexity
after their initial formation and subsequent growth. During sublimation, the small-scale complexity
disappeared, releasing a smooth and near-spherical ice particle. Angular light scattering and depolarization
measurements confirmed that these sublimating frozen droplets scattered light similar to spherical particles:
that is, they had angular light-scattering properties similar to water droplets. The knowledge gained from this
laboratory study was applied to two case studies of aircraft measurements in midlatitude and tropical convective
systems. The in situ aircraft measurements confirmed that the microphysics of frozen droplets is
dependent on the humidity conditions they are exposed to (growth or sublimation). The existence of optically
spherical frozen droplets can be important for the radiative properties of detraining convective outflows
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Erosio interdigitalis blastomycetica: A review of interdigital candidiasis
Erosio interdigitalis blastomycetica (EIB) is a Candida infection affecting the third web space, between the third and fourth fingers. In 1915, Gougerot and Goncea first described saccharomycetic organisms isolated from the hands and feet. Johannes Fabry later named it in 1917, well before the genus Candida was introduced in 1923. EIB is most common among those who work with their hands frequently in water, such as dishwashers, launderers, bartenders, and homemakers. Clinical presentation most commonly consists of a central erythematous erosion surrounded by a rim of white macerated skin involving at least one interdigital web space. The differential diagnosis is narrow, consisting of irritant contact dermatitis (ICD), erythrasma, inverse psoriasis, and bacterial infection (i.e. impetigo). The diagnosis is made by clinical examination in addition to fungal culture and KOH testing. The prognosis is good and treatment options include avoidance of frequent water immersion and topical or oral antifungal agents. Suspicion for secondary infections such as erysipelas and cellulitis should remain high until lesions have resolved. This review aims to address the history, epidemiology, pathophysiology, histopathology, clinical presentation, differential diagnoses, diagnosis, prognosis, and management of EIB. It also suggests an alternative name in place of the current misnomer
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Growth of mobile applications in dermatology - 2017 update
Background: More than 80% of households in the US have a smartphone. Growth of mobile applications (apps) has grown in parallel with access to smartphones. Mobile health apps are used in medical fields, including dermatology. These apps allow patients to access information regarding dermatology conditions as well as access physicians via teledermatology.Purpose: To analyze changes in number of dermatology mobile apps since 2014 and discuss benefits and drawbacks of mobile application growth to dermatology.Methods: Apple, Android, and Windows were queried for dermatology-related apps. The apps were categorized by purpose and compared to previously published data to assess growth and change in dermatology apps.Results: A total of 526 dermatology mobile apps were found corresponding to an 80.8% growth in dermatology apps since 2014. The market share of teledermatology increased from 11.0% in 2014 to 20.1% in 2017.Conclusions: Dermatology apps continue to grow at a comparable pace to general app growth. Teledermatology apps experienced significant growth from 2014 to 2017. This growth has allowed time-efficient and cost-effective access to dermatologists, especially in rural areas. The growth of dermatology apps targeting patients allows for patient autonomy but also can result in access to inaccurate information regarding dermatology conditions
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Industry payments to dermatologists: updates from the 2016 open payment data
Payments made to dermatologists by pharmaceutical and medical device manufacturing companies have become better understood following the advent of the Open Payments program. The purpose of this study was to analyze payments made to dermatologists in 2016 and evaluate trends in the payments from the previously published 2014 data
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Editorial boards of dermatology journals and their potential financial conflict of interest
Background: Financial relationships between editorial board members of peer-reviewed journals and pharmaceutical and medical device manufacturing companies can potentially lead to biases and loss of objectivity of the medical literature. The purpose of this study was to evaluate the potential financial conflicts of interest that exist among editorial board members of dermatology journals.Methods: Editorial board members for 36 dermatology journals were identified and searched using the Open Payments database on the Center for Medicare and Medicaid Services website. The total amount of general payments made to these physician editors were collected and stratified using a tier system: 1) nothing reported, 2) >0 and <10,000, 3) >10,000 and <100,000, and 4) >100,000.Conclusions: Financial relationships exist between editorial board members of dermatology journals and pharmaceutical/medical device manufacturing companies, which could lead to financial conflicts of interest. Publications coming from journals with highly paid physician editors have more potential to be biased
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Editorial boards of dermatology journals and their potential financial conflict of interest
Background: Financial relationships between editorial board members of peer-reviewed journals and pharmaceutical and medical device manufacturing companies can potentially lead to biases and loss of objectivity of the medical literature. The purpose of this study was to evaluate the potential financial conflicts of interest that exist among editorial board members of dermatology journals.Methods: Editorial board members for 36 dermatology journals were identified and searched using the Open Payments database on the Center for Medicare and Medicaid Services website. The total amount of general payments made to these physician editors were collected and stratified using a tier system: 1) nothing reported, 2) >0 and <10,000, 3) >10,000 and <100,000, and 4) >100,000.Conclusions: Financial relationships exist between editorial board members of dermatology journals and pharmaceutical/medical device manufacturing companies, which could lead to financial conflicts of interest. Publications coming from journals with highly paid physician editors have more potential to be biased
Liver retraction system by C3-muco-adhesive polymer films for laparoscopic surgery
Background:
Conventional laparoscopic instruments used for retraction may cause trauma at the retraction site. Alternative retraction/lifting especially of heavy solid organs such as the liver may be obtained by other means. The present study was designed to explore the use of C3-muco-adhesive polymers (C3-MAPs), which exhibit strong binding to the liver shortly after application to the organ and which retain strong adhesion for sufficient time, to enable sustained retraction during laparoscopic operations.
Methods and materials:
C3-muco-adhesive polymers were produced specifically for the study. In an ex vivo experimental set-up, discs of C3-MAPs were placed on the surface of porcine livers for adhesion and retraction studies involving objective measurements by tensiometry.
Results:
Experiments were carried out on 14 porcine livers. The force required to detach the C3-MAPs from the liver exceeded 2.0 N 30 s after application. The adhesion force by C3-MAPs files was sufficient to enable sustained retraction force necessary for exposure of the gall bladder, which was achieved by a mean retraction force of 4.85 N (SD = 0.63). This was sustained for a mean of 130 min (range 17.0-240.0). In the adhesion studies, the forces at 30 s required to detach the polymer discs from the liver exceeded 20 N (upper limit of the load cells of the Instron). The duration of the adhesion enabled sustained optimal gall bladder exposure for periods ranging from 17 to 240 min, with a mean of 130 ± 91 min.
Conclusions:
The results of the present study demonstrate that the adhesion and retraction properties of the engineered C3-MAP films are sufficient to enable complete exposure of the gall bladder for a period exceeding 1 h, confirming their potential for atraumatic retraction in laparoscopic and other minimal-access surgical approaches