Dynamic detection of electron spin accumulation in ferromagnet-semiconductor devices by ferromagnetic resonance

A distinguishing feature of spin accumulation in ferromagnet-semiconductor devices is precession of the non-equilibrium spin population of the semiconductor in a magnetic field. This is the basis for detection techniques such as the Hanle effect, but these approaches become less effective as the spin lifetime in the semiconductor decreases. For this reason, no electrical Hanle measurement has been demonstrated in GaAs at room temperature. We show here that by forcing the magnetization in the ferromagnet (the spin injector and detector) to precess at the ferromagnetic resonance frequency, an electrically generated spin accumulation can be detected from 30 to 300 K. At low temperatures, the distinct Larmor precession of the spin accumulation in the semiconductor can be detected by ferromagnetic resonance in an oblique field. We verify the effectiveness of this new spin detection technique by comparing the injection bias and temperature dependence of the measured spin signal to the results obtained using traditional methods. We further show that this new approach enables a measurement of short spin lifetimes (< 100 psec), a regime that is not accessible in semiconductors using traditional Hanle techniques.Comment: 4 figure

Return to activity following ACL Reconstruction with the Fertilized ACL: A retrospective study.

Background The objective of this retrospective study is to evaluate outcomes in patients who underwent the fertilized anterior cruciate ligament (ACL) reconstruction procedure. We aim to investigate the return to previous level of activity, safety, and re-rupture rates of the ACL reconstruction augmented with bone marrow concentrate, demineralized bone matrix, autograft bone, and a suture tape (the fertilized ACL). Methods A comprehensive review of medical records was conducted for patients treated with the fertilized ACL (FACL). Medical records of all the patients who underwent reconstruction surgery between July 2018 and January 2021 were evaluated. The inclusion criteria for the study were patients with a defined ACL tear based on clinical examination and magnetic resonance imaging testing who received FACL reconstruction between July 2018 and January 2021. Exclusion criteria included revision ACL reconstruction, non FACL reconstruction, and patients that underwent the FACL reconstruction outside of the defined time period. Thirteen patients underwent reconstruction using a Graftlink allograft (Lifenet Virginia Beach, Va) and 38 using quadriceps autografts. All patients received the FACL reconstruction using bone marrow concentrate, demineralized bone matrix, autograft bone, and suture tape. A phone survey was conducted to obtain patient-reported outcome measures including return to previous level of activity, International Knee Documentation Committee (IKDC), ACL Return to Sport After Injury (ACL RSI), and Visual Analogue Scale (VAS) values. A chart review was conducted for complications and questions were asked during the phone survey regarding return to operating room, infections, and re-ruptures. Results Data analysis revealed 94% of the patients returned to their previous level of activity. The average IKDC and ACL RSI scores were 94% (SD, 9.0) and 92% (SD,15.3), respectively. The average VAS score was .9/10 (SD, 1.2). One patient required reoperation for pain at 1 year. No re-ruptures were observed. Conclusion This retrospective study sheds light on the FACL, which adds biology and an internal brace to an ACL reconstruction, as a reliable and safe option when performing an ACL reconstruction. Very low complication rates were seen in this consecutive series followed for a mean of 2 years. Patients had an extremely high level of return to previous level of sport/activity

Understanding the patient experience in hepatocellular carcinoma: a qualitative patient interview study

Hepatocellular carcinoma; Quality of life; SymptomsCarcinoma hepatocelular; Calidad de vida; SíntomasCarcinoma hepatocel·lular; Qualitat de vida; SímptomesPurpose This study aimed to elucidate the patient experience of hepatocellular carcinoma (HCC) to guide patient-centered outcome measurement in drug development. Methods Patients with HCC participated in qualitative interviews to elicit disease-related signs/symptoms and impacts, using discussion guides developed from literature searches and discussions with oncologists. Interview participants rated the disturbance of their experiences (0–10 scale). A conceptual model was developed and mapped against patient-reported outcome (PRO) instruments identified from database reviews. Results Interviews were conducted with 25 individuals with HCC (68% were men; median age: 63 years; 12% Barcelona clinic liver cancer (BCLC) stage A; 32% stage B; and 56% stage C) in the USA. Fifty-one HCC-related concepts were identified from the interviews and were grouped into eight sign/symptom categories (eating behavior/weight changes; extremities [arms, legs]; fatigue and strength; gastrointestinal; pain; sensory; skin; other) and four impact categories (emotional; physical; cognitive function; other) for the conceptual model. The most prevalent and disturbing experiences across the disease stages were fatigue/lack of energy and emotional impacts such as frustration, fear, and depression. Abdominal pain and skin-related issues were particularly common and disturbing in individuals with HCC stage C. The EORTC QLQ-C30 and HCC18 were identified as commonly used PRO instruments in HCC studies and captured the relevant signs/symptoms associated with the patient experience. Conclusion Patients with HCC reported a range of signs/symptoms and impacts that negatively affect daily functioning and quality of life. Including PRO measures in HCC clinical trials can provide meaningful patient perspectives during drug development.This qualitative study was funded by AstraZeneca

Understanding Patient Experience in Biliary Tract Cancer: A Qualitative Patient Interview Study

Cáncer del tracto biliar; Estudio de entrevista; Investigación cualitativaCàncer del tracte biliar; Estudi d'entrevista; Recerca qualitativaBiliary tract cancer; Interview study; Qualitative researchIntroduction Patients living with biliary tract cancer (BTC) experience a decline in health-related quality of life (HRQoL). This study aimed to obtain a comprehensive understanding of the patient experience of BTC-related signs/symptoms and the impacts of these on daily functioning and HRQoL. Methods Patients with BTC participated in qualitative semi-structured concept elicitation interviews. Signs/symptoms and impacts of BTC were initially explored by targeted literature searches and interviews with five clinicians. Patient interviews were transcribed and coded using qualitative research software. Concept saturation was assessed over five interview waves. A sign/symptom or impact was defined as “salient” if mentioned by ≥ 50% of patients, with a mean disturbance rating of ≥ 5 (0–10 scale). A conceptual model of the patient experience of BTC-related signs/symptoms and impacts was produced. Results Twenty-three patients from the USA (78% women; median age: 54 years), diagnosed as having early (n = 3), locally advanced (n = 11) or metastatic (n = 9) disease, were interviewed. Sixty-six signs/symptoms and 12 impacts were identified. Of these, 46 signs/symptoms and 8 impacts were not identified from the targeted literature or clinician interviews. Concept saturation was reached by the fourth of five interview waves. Fourteen disease-related signs/symptoms (including fatigue/lack of energy, abdominal pain, lack of appetite, insomnia and diarrhoea) and three impacts (physical, emotional and cognitive impacts) were deemed “salient”. The conceptual model included 50 signs/symptoms and 12 impacts. Conclusion Patients with BTC reported a range of signs/symptoms and impacts that negatively affect daily functioning and HRQoL.This project was funded by AstraZeneca, Gaithersburg, MD, USA. Research and publication fees are funded by the study sponsor

Examining the Electrical Excitation, Calcium Signaling, and Mechanical Contraction Cycle in a Heart Cell

As the leading cause of death in the United States, heart disease has become a principal concern in modern society. Cardiac arrhythmias can be caused by a dysregulation of calcium dynamics in cardiomyocytes. Calcium dysregulation, however, is not yet fully understood and is not easily predicted; this provides motivation for the subsequent research. Excitation-contraction coupling (ECC) is the process through which cardiomyocytes undergo contraction from an action potential. Calcium induced calcium release (CICR) is the mechanism through which electrical excitation is coupled with mechanical contraction through calcium signaling. The study of the interplay between electrical excitation, calcium signaling, and mechanical contraction has the potential to improve our understanding of the regular functioning of the cardiomyocytes and help us understand how any dysregulation can lead to potential cardiac arrhythmias. ECC, of which CICR is an important part, can be modeled using a system of partial differential equations that link the electrical excitation, calcium signaling, and mechanical contraction components of a cardiomyocyte. We extend a previous model [Angeloff et al., Spora, 2016] to implement a seven-variable model that includes for the first time the mechanical component of the ECC. We study how the interaction of electrical and calcium systems can impact the cardiomyocyte\u27s levels of contraction