Despite being one of the most common oral mucosal diseases and recognized as early as 1866, oral lichen planus (OLP) is still a disease without a clear etiology or pathogenesis, and with uncertain ...premalignant potential. More research is urgently needed; however, the research material must be based on an accurate diagnosis. Accurate identification of OLP is often challenging, mandating inclusion of clinico-pathological correlation in the diagnostic process. This article summarizes current knowledge regarding OLP, discusses the challenges of making an accurate diagnosis, and proposes a new set of diagnostic criteria upon which to base future research studies. A checklist is also recommended for clinicians to provide specific information to pathologists when submitting biopsy material. The diagnostic process of OLP requires continued clinical follow-up after initial biopsy, because OLP mimics can manifest, necessitating an additional biopsy for direct immunofluorescence study and/or histopathological evaluation in order to reach a final diagnosis.
The Kepler mission was designed to determine the frequency of Earth-sized planets in and near the habitable zone of Sun-like stars. The habitable zone is the region where planetary temperatures are ...suitable for water to exist on a planet's surface. During the first 6 weeks of observations, Kepler monitored 156,000 stars, and five new exoplanets with sizes between 0.37 and 1.6 Jupiter radii and orbital periods from 3.2 to 4.9 days were discovered. The density of the Neptune-sized Kepler-4b is similar to that of Neptune and GJ 436b, even though the irradiation level is 800,000 times higher. Kepler-7b is one of the lowest-density planets (approximately 0.17 gram per cubic centimeter) yet detected. Kepler-5b, -6b, and -8b confirm the existence of planets with densities lower than those predicted for gas giant planets.
Metal Plates and Foils for Closure of Oroantral Fistulae Steiner, Martin, DDS; Gould, Alan R., DDS, MS; Madion, Daniel C., DDS, MD ...
Journal of oral and maxillofacial surgery,
07/2008, Letnik:
66, Številka:
7
Journal Article
•Significant variation is seen in the fracture location of segmental femur fractures, especially with regards to the proximal fracture.•Good outcomes in terms of alignment and union can be expected ...in segmental femur fractures.•A simple radiographic cover-up test can guide the choice of fixation and result in the gold standard of fixation being used for most fractures.
Segmental femur fractures often pose management challenges regarding the optimal fixation choice and sequence of surgical events.
Retrospective review of clinical records and radiographic data of adult patients with segmental femur fractures treated by a conceptual radiographic cover-up test to determine the ideal fixation method between January 2019 and December 2020.
Forty patients with 84 individual fractures underwent fracture fixation. The most consistent fracture combinations were intertrochanter-diaphysis (AO31A-AO32) fractures (25%, n = 10) and femur neck-diaphysis (AO31B-AO32) fractures (20%, n = 8). Compared to evidence-based fracture management, the gold standard treatment was used for the fixation of 78 fractures (93%). One patient required revision for fixation failure of a diaphyseal fracture, and two fractures, both open diaphysis injuries, developed fracture-related infections.
Anatomical alignment and high union rates are possible for segmental femur fractures treated by evidence-based fracture fixation principles. A conceptual radiographic cover-up test assists in matching the best possible implant for each fracture.
Abstract
We present the occurrence rates for rocky planets in the habitable zones (HZs) of main-sequence dwarf stars based on the Kepler DR25 planet candidate catalog and Gaia-based stellar ...properties. We provide the first analysis in terms of star-dependent instellation flux, which allows us to track HZ planets. We define
η
⊕
as the HZ occurrence of planets with radii between 0.5 and 1.5
R
⊕
orbiting stars with effective temperatures between 4800 and 6300 K. We find that
η
⊕
for the conservative HZ is between
(errors reflect 68% credible intervals) and
planets per star, while the optimistic HZ occurrence is between
and
planets per star. These bounds reflect two extreme assumptions about the extrapolation of completeness beyond orbital periods where DR25 completeness data are available. The large uncertainties are due to the small number of detected small HZ planets. We find similar occurrence rates between using Poisson likelihood Bayesian analysis and using Approximate Bayesian Computation. Our results are corrected for catalog completeness and reliability. Both completeness and the planet occurrence rate are dependent on stellar effective temperature. We also present occurrence rates for various stellar populations and planet size ranges. We estimate with 95% confidence that, on average, the nearest HZ planet around G and K dwarfs is ∼6 pc away and there are ∼4 HZ rocky planets around G and K dwarfs within 10 pc of the Sun.
We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise ...Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities (FPPs) for all of the transiting planets (41 of 42 have an FPP under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than three times the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify six planets with densities above 5 g cm super(-3), suggesting a mostly rocky interior for them. Indeed, the only planets that are compatible with a purely rocky composition are smaller than ~2 R sub(+ in circle). Larger planets evidently contain a larger fraction of low-density material (H, He, and H sub(2)O).
Chasing Shadows DeVore, Edna; Gould, Alan
The Science teacher (National Science Teachers Association),
03/2017, Letnik:
84, Številka:
3
Journal Article
Recenzirano
The solar eclipse coming August 21 offers students the opportunity not only to explore the geometry of the solar system but also to learn about exoplanets transiting distant stars. Students can ...glimpse a great frontier of science: the search for other worlds and life. This article presents information on exoplanets, discovering planets around distant stars, and an activity to incorporate into the classroom.
PDF
