THE SUPRA-CHONDRITIC 7LI/6LI IN THE HIBONITE-RICH FUN INCLUSION HIDALGO IN DAR AL GANI 027 (CO3): A HINT FOR THE FORMER PRESENCE OF BERYLLIUM-7?
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Astronomy and AstroPhysics↗
Engineering topics
Liu, M C
Publications and source records attributed to Liu, M C.
Ryugu's nucleosynthetic heritage from the outskirts of the Solar System
Little is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. Here we show that samples returned from Cbtype asteroid Ryugu have Fe isotopic anomalies indistinguishable from Ivunatype (CI) chondrites, which are distinct from all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate that Ryugu and CI chondrites formed in a reservoir that was different from the source regions of other carbonaceous asteroids. Growth and migration of the giant planets destabilized nearby planetesimals and ejected some inwards to be implanted into the Main Belt. In this framework, most carbonaceous chondrites may have originated from regions around the birthplaces of Jupiter and Saturn, while the distinct isotopic composition of CI chondrites and Ryugu may reflect their formation further away in the disk, owing their presence in the inner Solar System to excitation by Uranus and Neptune
58 GEOSCIENCES↗
The Timing of Early Solar System Reservoir Separation
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Geosciences↗
Radiotherapy Can Decrease Locoregional Recurrence and Increase Survival in Mastectomy Patients With T1 to T2 Breast Cancer and One to Three Positive Nodes With Negative Estrogen Receptor and Positive Lymphovascular Invasion Status
Purpose: To define a subgroup of patients at high risk of locoregional recurrence (LRR) who might be benefit from postmastectomy radiotherapy in invasive breast cancer and tumor size <5 cm with one to three involved axillary lymph nodes (T1-2 N1). Methods and Materials: Between April 1991 and December 2005, 544 patients with T1-2 N1 invasive breast cancer were treated with modified radical mastectomy. Of the 544 patients, 383 patients (70.4%) had no radiotherapy, and 161 patients (29.6%) received radiotherapy. We retrospectively compared these two patient groups. Results: With a median follow-up of 40.3 months, LRR occurred in 40 (7.4%) of 544 patients. On univariate analysis, high nuclear grade (p = 0.04), negative estrogen receptor (ER) status (p = 0.001), presence of lymphovascular invasion (LVI) (p = 0.003), and no radiotherapy (p = 0.0015) were associated with a significantly higher rate of LRR. Negative ER status (hazard ratio = 5.1) and presence of LVI (hazard ratio = 2.5) were the risk factors for LRR with statistical significance in the multivariate analysis. Radiotherapy reduced the LRR in patients with the following characteristics: age <40 years, T2 stage, high nuclear grade, negative ER status, and presence of LVI. For 41 patients with negative ER and positive LVI status, radiotherapy can reduce LRR from 10 of 25 (40%) to 2 of 16 (12.5%) and increase the 5-year overall survival from 43.7% to 87.1%. Conclusion: Radiotherapy can reduce LRR and increase survival in T1-2 N1 breast cancer patients with negative ER status and presence of LVI.
62 RADIOLOGY AND NUCLEAR MEDICINE↗