Search

This randomized trial of fractionation after breast reconstruction (FABREC) sought to compare quality-of-life (QOL) and clinical outcomes of hypofractionated (HF) vs. conventionally-fractionated (CF) postmastectomy radiation therapy (PMRT) in the setting of immediate prosthetic reconstruction. Between 3/2018 and 11/2021, 400 patients at 18 centers with Stage 0-III breast cancer and immediate placement of tissue expander (TE) or implant (I) after mastectomy were randomized 1:1 to HF or CF photon PMRT. Respective doses in the two arms were 42.56 Gy/16 fractions to the chest wall (CW), with or without axillary/supraclavicular lymph node (LN) radiation (39.9 Gy/15 fractions) and 50 Gy in 25 fractions to CW (46-50 Gy to axillary LNs). A boost was not permitted; bolus was used at physician discretion. CW toxicity was defined as any grade ≥3 adverse event (CTCAE) after PMRT initiation. Patients were censored at study withdrawal or at diagnosis of distant recurrence. Participants completed QOL instruments (FACT-B, BREAST-Q, Lymph-ICF) at baseline, 6, 12 and 18-months from PMRT initiation. Questions regarding financial burden were included with the 6-month survey. Primary endpoint of the study was improvement in the Physical Well-Being (PWB) domain of FACT-B at 6 months with pre-specified stratification by age (younger than 45 vs. 45 years or older). QOL scores were compared using Student's t-test. Median follow-up for the 385 patients analyzed was 31.8 months (range, 6.9-54.4); median age was 47.0 years (range, 23-79). Preoperative chemotherapy was used in 67.8% and preoperative endocrine therapy (ET) in 21.5% of the cohort. There were 16 distant (8 in each arm), and 2 local-regional (1 in each arm) recurrences. CW toxicity occurred in 35 patients (19 HF, 16 CF, p=0.58) at medians of 3.4 and 4.8 months after RT initiation in the HF and CF arms, respectively (p=0.82). Post-operative infection before RT (HR=3.31, p=0.03), irradiation of TE vs I (HR=7.74, p=0.046), preoperative endocrine therapy (HR=3.45, p=0.0007) and number of LNs removed (HR=1.06/node, p=0.02) were significant for developing CW toxicity on multivariate analysis, while fractionation was not (HF HR=1.19, p=0.63). There was no significant difference in overall change in PWB scores at 6 months between the two treatment arms (p=0.71) or separately in younger (p=0.15) and older cohorts (p=0.27). However, HF patients younger than 45 were less bothered by side-effects of treatment (p=0.045) and nausea (p=0.02) vs. CF patients younger than 45. Among patients who took unpaid time off from work during treatment (n=51), those receiving HF required fewer hours off than those receiving CF (73.7 vs. 125.8, p=0.046). Physical well-being and overall toxicity profile of HF PMRT were comparable between HF and CF PMRT. HF was associated with better 6-month QOL in some domains among younger patients. Our early results support the use of HF PMRT in the setting of TE- or implant-based breast reconstruction. [ABSTRACT FROM AUTHOR]

Ferromagnetic layered structure has been made at sub-surface of the antiferromagnetic FeRh bulk samples by high energy He ion beam irradiation. In accordance with the Transport of Ions in Matter simulation, such ion beam can effectively deposit the elastic collision energy in several lm regions in the depth from the surface. Measurement with a superconducting quantum interference device reveals the irradiated samples to be ferromagnetic. Assuming that only the part the energy deposited can be modified to be ferromagnetic, the corresponding irradiation induced magnetization is consistent with the data that we previously reported. On the other hand, the X-ray magnetic circular dichroism (XMCD) spectra for the irradiated samples are totally unchanged as those for the unirradiated samples. Since XMCD signal in total emission yield method is considered to be surface sensitive with a typical probing depth of several nm, the surface magnetic state is maintained to be antiferromagnetic. By utilizing these phenomena, three-dimensional magnetic patterning of FeRh can be realized, which may potentially be used for future magnetic exchange device application such as nano-scale sensors and memories. [ABSTRACT FROM AUTHOR]

Little is known about the ecology of insect species in the hyporheic zone of rivers, despite its importance in understanding how species survive in specialized habitats. We report on the life history and trophic characteristics of the hyporheic stonefly species Alloperla ishikariana Kohno, 1953 (Order: Plecoptera, Family: Chloroperlidae) in a gravel-bed river in northern Japan, using year-round sampling of both benthic and hyporheic larvae, as well as flying adults in the riparian zone. Adults emerged between May and August, and the larval cohort structure consisted of three sized groups with some sex dimorphism in their body size, with an average growth rate of 0.0043 mg/day. Diet analyses based on C and N stable isotope ratios indicated minimal ontogenetic diet shifts. In contrast, the temporal diet shift was more apparent with higher dependence on Oligochaeta in winter, with an increasing dependence on Chironomidae in spring and early summer. Other insect taxa, namely, Leuctridae and small-sized Lepidostoma, demonstrated a high to moderate affinity for the hyporheic zone. Alloperla ishikariana spent most of its larval stage in the hyporheic zone. With adults living from 7 to 10 days, A. ishikariana completes a life span of approximately 3 years with its larval stage in the dark. [ABSTRACT FROM AUTHOR]

For a two-group comparative study, a stratified inference procedure is routinely used to estimate an overall group contrast to increase the precision of the simple two-sample estimator. Unfortunately, most commonly used methods including the Cochran-Mantel-Haenszel statistic for a binary outcome and the stratified Cox procedure for the event time endpoint do not serve this purpose well. In fact, these procedures may be worse than their two-sample counterparts even when the observed treatment allocations are imbalanced across strata. Various procedures beyond the conventional stratified methods have been proposed to increase the precision of estimation when the naive estimator is consistent. In this paper, we are interested in the case when the treatment allocation proportions vary markedly across strata. We study the stochastic properties of the two-sample naive estimator conditional on the ancillary statistics, the observed treatment allocation proportions and/or the stratum sizes, and present a biased-adjusted estimator. This adjusted estimator is asymptotically equivalent to the augmentation estimators proposed under the unconditional setting. Moreover, this consistent estimation procedure is also equivalent to a rather simple procedure, which estimates the mean response of each treatment group first via a stratum-size weighted average and then constructs the group contrast estimate. This simple procedure is flexible and readily applicable to any target patient population by choosing appropriate stratum weights. All the proposals are illustrated with the data from a cardiovascular clinical trial, whose treatment allocations are imbalanced. [ABSTRACT FROM AUTHOR]

A method for fabricating adhesively bonded joints with graded properties along the bond-line was proposed. By utilizing two types of acrylic adhesives, one hard and the other soft, the properties of the mixture were changed by controlling the mixing ratio. An applicator for the adhesives was developed and used for the experiments, in which property-graded adhesive layers were actually produced. The properties, i.e., stress-strain curves at various points of the property-graded adhesive layer, were experimentally measured, and the validity of the proposed method was confirmed. The Young's moduli at multiple points of the adhesive layer changed from 34.7 MPa to 634 MPa by changing the mixing ratio of the adhesives. [ABSTRACT FROM AUTHOR]