Influence of bismuth doping on structural, electrical and dielectric properties of Ni–Zn nanoferrites

Recent advances on synthesis, characterization and high frequency applications of Ni-Zn ferrite nanoparticles

Structural and magnetic properties of La0.6Ca0.4−xSrxMnO3 manganites have been investigated for x = 0.0, 0.1 and 0.4. The Rietveld analysis of X-ray diffraction data indicates that, with increasing Sr content, a structural phase transition from rhombohedral to orthorhombic is occurred. Structural parameters are calculated and found to be dependent upon the composition. The nanometric size of our samples estimated using Debye–Scherrer equation is confirmed by SEM images. Magnetic measurements according to the zero-field cooled and field cooled procedures are performed. The observed irreversibility between the two modes is assigned to the presence of magnetic anisotropy which has been explained as arising from the surface effects. The blocking temperature (TB) is estimated and found to increase as the particle size increases. Above TB, the materials show a superparamagnetic (SPM) behavior where the coercivity and remanence magnetizations are almost zero that favors their application in the biomedical field. Studying the thermal variation of dc susceptibility confirms the SPM nature of the studied compounds. The good fit of the magnetization vs. magnetic field curves with Langevin function supports our findings. From this simulation, the saturation magnetization is calculated and found to increase as particle size increases which is explained in terms of Core–shell model. With the reduction of particle size to the nanometric scale, single domain structure and SPM regime structure are detected.

Structural characterization and ZFC/FC magnetization study of La 0.6 Ca 0.4−x Sr x MnO 3 nanoparticle compounds

Spin glass freezing, magnetocapacitance and dielectric anomalies in 0.3NiFe2O4-0.7BiFeO3 nanocomposite

We report on structural, chemical and low-temperature magnetic properties of lead-free 0.6NiFe2O4-0.4Na0.5Bi0.5TiO3 composite. NiFe2O4 (NFO) and Na0.5Bi0.5TiO3 (NBTO) are seen to crystallize in inverse spinel and perovskite structure, respectively. 0.6NiFe2 O4-0.4Na0.5Bi0.5TiO3 composite exhibits both NFO and NBTO phases in appropriate composition. Zero field-cooled (ZFC) and field-cooled (FC) magnetization measurements carried out from 15 to 300 K shows a large bifurcation at room temperature. ZFC and FC magnetization measurement exhibit a hump at Tm $$\sim$$
 259.5 K, indicates the possible existence of competing magnetic interactions in 0.6NiFe2 O4-0.4Na0.5Bi0.5TiO3 composite. Saturation magnetization, remnant magnetization and coercivity values are observed to increase with decreasing the temperature. Temperature-dependent saturation magnetization is fit to the Bloch’s law. Magnetocrystalline anisotropy (K1) value at various temperatures are estimated and is seen to increase from 0.23 × 104 erg/cc (at 300 K) to 0.34 × 104 erg/cc (at 15 K).

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Structural, chemical and low-temperature magnetic properties of lead-Free 0.6NiFe2O4-0.4Na0.5Bi0.5TiO3 magnetoelectric composite

Competing magnetic interactions and superparamagnetism like behaviour in xNiFe2O4 - (1-x)BaTiO3 (x = 0.2 and 0.3) nano composites


 Background. Patient-reported outcomes (PROs) are increasingly recognized as a valuable component to understand treatment tolerability and toxicity among patients on clinical trials. We have implemented a system for monitoring patient reported outcomes (PROs), symptoms, and quality of life (QOL) using electronic PRO (ePRO) instruments for patients enrolled in the I-SPY2 trial. I-SPY2 is a phase II multi-site clinical trial evaluating the effect of novel neoadjuvant therapies for locally advanced breast cancer. We correlated patient demographic factors with symptoms, investigated the trajectory of symptoms throughout treatment, and sought to characterize symptoms associated with decline in physical function (PF). Methods. Our study population included 259 I-SPY2 patients that completed surveys on one of 9 study arms (including novel oral taxane/immunotherapy combinations, IV paclitaxel, checkpoint inhibitor+/- LAG3 inhibitor, and control IV paclitaxel +/- trastuzumab/pertuzumab). After the 12 week period of investigational agents, most patients received standard adriamycin and cyclophosphamide (AC). Symptom severity, frequency, and interference was assessed weekly using 33 items from the PRO-CTCAE item bank. PF was assessed using the NIH PROMIS instrument and was evaluated at baseline, inter-regimen (after 12 weeks of treatment), pre-surgery, and 1 and 6 months at follow-up. An odds ratio was used to assess univariate associations between age and race, and symptoms. Regularized multi-variate regression was used to evaluate early symptoms (prior to week 6) predictive of a clinically significant (>5 point T-score) decline in PF from baseline to post-treatment follow-up among all races and age groups. Results. Of 259 patients (mean age (SD) = 46.8 (13.6)), 160 (58%) were White, 13 (5%) were Asian, 26 (10%) were African American (AA), 25 (9.3%) were Hispanic, and 35 (13.5%) self-reported “Other”. At baseline, AA patients had a higher severity of joint pain than White patients (OR = 14.9, P < 0.05). During study treatment with paclitaxel and/or novel agent within the first 12 weeks of treatment, AA patients and non-white (NW) patients were more likely to report severe vomiting than White patients (OR =13.22 and 12.72, P< 0.05 and P< 0.03 respectively). During treatment with AC, NW patients were more likely to report higher severity of neuropathy than White patients (OR = 5.43, P< 0.03). Among all patients, in analysis of early symptoms predictive of a clinically significant decline in PF between baseline and 1 month post treatment, predictors included high frequency of diarrhea, severity of itching, and severity of joint pain. Further analysis of symptom trajectories revealed that frequency of diarrhea reported rose sharply between baseline and Cycle 2 with 9 patients (7%) reporting occasional or frequent diarrhea to 39 patients (28%) reporting occasional to almost constant diarrhea and remained stable at that proportion for the remainder of treatment. Frequency of diarrhea declined slightly during AC (17%) and dropped to baseline levels by follow-up. In contrast, severity of joint pain persisted post-treatment, rising consistently from baseline through follow- up with 3 patients (2%) reporting moderate to severe joint pain at baseline to 18 patients (35%) reporting moderate to severe joint pain at follow-up. Conclusion. Among I-SPY2 participants, when higher grade of diarrhea is persistent (or uncontrolled), it impacts physical function even after end of therapy. In some cases, race was also a determinant in symptom trajectory, although a higher enrollment of AA and NW patients will enable more robust estimates to be computed. While some of these early symptom predictors are transient and resolve by the time of follow-up, others persist long-term and contribute more directly towards impaired physical function at follow-up.
 Citation Format: Amrita Basu, Saumya Umashankar, Kaylee Blevins, Anna Northrop, Anika Christofferson, Ebunoluwa Olunuga, Jaeyoon Cha, Ananya Mittal, Julissa Molina-Vega, Laura Sit, Thelma Brown, Bev Parker, Diane Heditsian, Susie Brain, Carol Simmons, Alessandra Taboada, Tina J. Hieken, Kathryn Ruddy, Carolina Salvador, Candace Mainor, Anosheh Afghahi, Sarah Tevis, Anne Blaes, Irene M. Kang, Jane Perlmutter, Hope Rugo, Sai Kanaparthi, Garry Peterson, Lisa T. Weiss, Adam Asare, Laura J. Esserman, Michelle Melisko, Dawn Hershman. The Association Between Symptom Severity and Physical Function among Participants in I-SPY2 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-07-03.

Abstract P5-07-03: The Association Between Symptom Severity and Physical Function among Participants in I-SPY2


 Background. Immunotherapy has emerged as an important component of neoadjuvant therapy for some patients with breast cancer (BC). As a result, immune-related adverse events (irAEs) are increasing and have effects on both short and long term symptoms significantly impacting patient quality of life. BC patients may develop new conditions including arthralgias, gastrointestinal issues, endocrinopathies, and fatigue during or after cancer therapy that may be acute or long-lasting in nature. Monitoring for early onset and severity of symptoms, and adjusting treatment and symptom management could optimize therapy for a particular patient, maximizing potential efficacy while mitigating toxicity. We sought to identify patient demographic characteristics and symptom patterns associated with risk for development of irAEs in the context of a randomized trial for patients with early-stage high-risk breast cancer. Methods. I-SPY2 is a multi-center, phase 2 trial using response-adaptive randomization for high-risk early-stage women with BC. The study population for this analysis includes enrolled patients receiving combinations of experimental immunotherapy and chemotherapy. Groups considered for statistical comparisons included those that developed an irAE versus those that did not develop an irAE up until the surgery timepoint. In I-SPY adverse events are documented through the Common Terminology Criteria for Adverse Events (CTCAEv5.0). Hypothyroidism, adrenal insufficiency, and pneumonitis were the irAEs considered in this study. A chi-square test was used to assess associations between race and ethnicity (White, Asian, Black, non-Hispanic) and irAEs. One-way ANOVA was used to evaluate the association between age (>50 vs < 50) and irAEs. 33 symptoms reported at CTCAE grade 2 or higher were included in the analyses and a symptom burden score was calculated using area under curve (AUC) which combined the duration of each symptom between baseline and week 6 of treatment, and grade of adverse event. Regularized regression using leave-one out cross validation was used to evaluate early symptoms (as quantified by the symptom burden score) as predictors, and irAEs as surrogate responses. Results. Out of 461 patients, percentages of patients wth irAEs of interest included hypothyroidism (13%), adrenal insufficiency (9%), and pneumonitis (4%). Demographic information was available for 333 patients, of which 270 (81%) were White, 23 (7%) were Asian, 37 (11%) were African American (AA) and 278 (17%) were non-Hispanic. There were proportionately higher number of white patients that developed hypothyroidism than non-white patients (35 of 265 (13%) vs 2 of 63 (3%), P < 0.04). Pneumonitis was more common in patients over 50 years old than under 50 years old (P < 0.02). Symptoms that were most commonly reported up to week 6 of treatment among patients who developed an irAE included: diarrhea (36%), fatigue (15%), dizziness (12%) and shortness of breath (SOB) (11%). Symptoms associated with the development of hypothyroidism included fatigue (15%, mean AUC=11.8 vs 5.8 for those that did not develop irAE), SOB (11%, 4.3 vs 2.8), and blurry vision (1%, 1.0 vs 0.12). Development of adrenal insufficiency was associated with early reports of diarrhea (36%, 19.0 vs 10.5), SOB (11%, 7.8 vs 2.6), joint pain (3%, 2.29 vs 0.58), decreased appetite (3%, 3.55 vs 0.91), and constipation (1%, 3.6 vs 0.02). No significant early symptoms emerged for pneumonitis due to a limited number of events. Conclusion. Our study utilizes an analysis framework that is aimed to determine symptom clusters that predict the development of irAEs. We describe specific symptoms presenting early with the development of hypothyroidism and adrenal insufficiency, in recognition of allowing physicians to be more diligent in active and post treatment monitoring.
 Citation Format: Amrita Basu, Saumya Umashankar, Michelle Melisko, Ruixiao Lu, Hongmei Yu, Christina Yau, Smita Asare, Maria Pitsouni, Rebecca A. Shatsky, Claudine Isaacs, Angela DeMichele, Dawn Hershman, Rita Nanda, Mi-Ok Kim, Laura J. Esserman, Hope Rugo. Identification of symptoms that are associated with irAEs in the I-SPY clinical trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS5-04.

S. Umashankar

Papers

Competing magnetic interactions and superparamagnetism like behaviour in xNiFe2O4 - (1-x)BaTiO3 (x = 0.2 and 0.3) nano composites

Abstract P5-07-03: The Association Between Symptom Severity and Physical Function among Participants in I-SPY2

Abstract GS5-04: Identification of symptoms that are associated with irAEs in the I-SPY clinical trial