Quantitative Measurements Research Articles

Towards a lifelong personalized brain health program: empowering individuals to define, pursue, and monitor meaningful outcomes.

Incorporating person-centered outcomes into clinical trials for neurodegenerative diseases has been challenging due to a deficiency in quantitative measures. Meanwhile, the integration of personally meaningful treatment targets in clinical practice remains qualitative, failing to truly inform evaluations, therapeutic interventions and longitudinal monitoring and support. We discuss the current advances and future directions in capturing individualized brain health outcomes and present an approach to integrate person-centered outcome in a scalable manner. Our approach stems from the evidence-based electronic Person-Specific Outcome Measure (ePSOM) program which prompts an individual to define personally meaningful treatment priorities and report level of confidence in managing items that matter to the individual the most (e.g., "Do I feel confident in my ability to contribute to a conversation?"). Deployed either as a single version (person only) or a dyad version (person and care partner), our proposed tool could be used as an endpoint in clinical trials, offering proof of meaningful intervention benefits and in clinical practice, by establishing an anchor for the therapeutic objectives sought by the individual.

Postmortem imaging reveals patterns of medial temporal lobe vulnerability to tau pathology in Alzheimer’s disease

Our current understanding of the spread and neurodegenerative effects of tau neurofibrillary tangles (NFTs) within the medial temporal lobe (MTL) during the early stages of Alzheimer’s Disease (AD) is limited by the presence of confounding non-AD pathologies and the two-dimensional (2-D) nature of conventional histology studies. Here, we combine ex vivo MRI and serial histological imaging from 25 human MTL specimens to present a detailed, 3-D characterization of quantitative NFT burden measures in the space of a high-resolution, ex vivo atlas with cytoarchitecturally-defined subregion labels, that can be used to inform future in vivo neuroimaging studies. Average maps show a clear anterior to poster gradient in NFT distribution and a precise, spatial pattern with highest levels of NFTs found not just within the transentorhinal region but also the cornu ammonis (CA1) subfield. Additionally, we identify granular MTL regions where measures of neurodegeneration are likely to be linked to NFTs specifically, and thus potentially more sensitive as early AD biomarkers.

“It’s Time to see What I Can Do”: A Mixed-Methods Investigation into Trajectories of Resilience in Adolescents during the COVID-19 Pandemic

AbstractThere is a concern that adolescent mental well-being and resilience has been adversely affected by the COVID-19 pandemic. Consequently, the aim of the current investigation was to track adolescents’ resilience from the initial months of the pandemic (T1) to approximately two years later (T2) using both qualitative and quantitative methods. Through interviews, thirty-one adolescents narrated their COVID-19 experiences and reflected on their mental well-being across this timespan. Using these accounts, we identified four groups of adolescents exhibiting one of the following trajectories of resilience: (1) Enduring resilience, (2) Reaching resilience, (3) Declining resilience and (4) Enduring non-resilience. Our findings revealed that most adolescents were able to maintain or develop good resilience on prolonged exposure to COVID-19 adversity (trajectories 1 and 2). This finding is contrary to the prevailing notion that the majority of adolescents’ mental well-being and hence resilience was adversely impacted by COVID-19 in the short and long term. Further qualitative analysis identified key factors that contributed to maintaining and developing greater levels of resilience during the pandemic: quality of friendships, quality of family relationships and regaining a sense of control. Lastly, we found a lack of congruence between quantitative and qualitative measures of mental well-being and resilience, suggesting that they might tap into different constructs/experiences. Significantly, our findings highlight that the majority of teens showed adaptive resilience during the pandemic and highlight the need for further longitudinal qualitative and quantitative research to assess both adaptive and maladaptive impacts of adversity on the adolescents’ mental well-being and resilience.

Entropy-based syntactic tree analysis for text classification: a novel approach to distinguishing between original and translated Chinese texts

Abstract This research focuses on classifying translated and non-translated Chinese texts by analyzing syntactic rule features, using an integrated approach of machine learning and entropy analysis. The methodology employs information entropy to gauge the complexity of syntactic rules in both text types. The methodology is based on the concept of information entropy, which serves as a quantitative measure for the complexity inherent in syntactic rules as manifested from tree-based annotations. The goal of the study is to explore whether translated Chinese texts demonstrate syntactic characteristics that are significantly different from those of non-translated texts, thereby permitting a reliable classification between the two. To do this, the research calculates information entropy values for syntactic rules in two comparable corpora, one of translated and the other of non-translated Chinese texts. Then, various machine learning models are applied to these entropy metrics to identify any significant differences between the two groups. The results show significant differences in the syntactic structures. Translated texts have a higher degree of entropy, indicating more complex syntactic constructs compared to non-translated texts. These findings contribute to our understanding of the effect of translation on language syntax, with implications for text classification and translation studies.

The dynamics of syntactic and lexical complexity measures in academic writing

This study explores the L2 production of university students enrolled in an English as a Medium of Instruction (EMI) course, by means of the analysis of the complexity of their academic writing performance. It focuses on syntactic and lexical complexity and their relationship with L2 writing quality and L2 proficiency. The participants were 182 L2 college-level students at difference levels of proficiency in English. The essays were evaluated by means of both global ratings of writing quality and quantitative measures of syntactic and lexical analysis. Results showed that the length of sentences and noun phrases, as well as subordination are all related to writing quality. In addition, the length of noun phrases along with lexical richness and diversity can differentiate proficiency levels. This study shows a greater use of complex phrasal constructions in the writing of more competent third-level students. Finally, our study that at advanced competence levels syntactic and lexical complexity are not synchronous, as syntactic complexity remains stable while lexical complexity continues increasing.

Effects and avoidance of photoconversion-induced artifacts in confocal and STED microscopy.

Fluorescence microscopy is limited by photoconversion due to continuous illumination, which results in not only photobleaching but also conversion of fluorescent molecules into species of different spectral properties through photoblueing. Here, we determined different fluorescence parameters of photoconverted products for various fluorophores under standard confocal and stimulated emission depletion (STED) microscopy conditions. We observed changes in both fluorescence spectra and lifetimes that can cause artifacts in quantitative measurements, which can be avoided by using exchangeable dyes.

Patient and Public Involvement and Engagement in the Development of a Platform Clinical Trial for Parkinson's Disease: An Evaluation Protocol.

Patient and public involvement and engagement (PPIE) in the design of trials is important, as participant experience critically impacts delivery. The Edmond J Safra Accelerating Clinical Trials in PD (EJS ACT-PD) initiative is a UK consortium designing a platform trial for disease modifying therapies in PD. The integration of PPIE in all aspects of trial design and its evaluation throughout the project. PwP and care partners were recruited to a PPIE working group (WG) via UK Parkinson's charities, investigator patient groups and participants of a Delphi study on trial design. They are supported by charity representatives, trial delivery experts, researchers and core project team members. PPIE is fully embedded within the consortium's five other WGs and steering group. The group's terms of reference, processes for effective working and PPIE evaluation were co-developed with PPIE contributors. 11 PwP and 4 care partners have supported the PPIE WG and contributed to the development of processes for effective working. A mixed methods research-in-action study is ongoing to evaluate PPIE within the consortium. This includes the Patient Engagement in Research Scale -a quantitative PPIE quality measure; semi-structured interviews -identifying areas for improvement and overall impressions of involvement; process fidelity- recording adherence; project documentation review - identifying impact of PPIE on project outputs. We provide a practical example of PPIE in complex projects. Evaluating feasibility, experiences and impact of PPIE involvement in EJS ACT-PD will inform similar programs on effective strategies. This will help enable future patient-centered research.

Quantifying tissue temperature changes induced by infrared neural stimulation: numerical simulation and MR thermometry

Infrared neural stimulation (INS) delivered via short pulse trains is an innovative tool that has potential for us use for studying brain function and circuitry, brain machine interface, and clinical use. The prevailing mechanism for INS involves the conversion of light energy into thermal transients, leading to neuronal membrane depolarization. Due to the potential risks of thermal damage, it is crucial to ensure that the resulting local temperature increases are within non-damaging limits for brain tissues. Previous studies have estimated damage thresholds using histological methods and have modeled thermal effects based on peripheral nerves. However, additional quantitative measurements and modeling studies are needed for the central nervous system. Here, we performed 7 T MRI thermometry on ex vivo rat brains following the delivery of infrared pulse trains at five different intensities from 0.1-1.0 J/cm2 (each pulse train 1,875 nm, 25 us/pulse, 200 Hz, 0.5 s duration, delivered through 200 µm fiber). Additionally, we utilized the General BioHeat Transfer Model (GBHTM) to simulate local temperature changes in perfused brain tissues while delivering these laser energies to tissue (with optical parameters of human skin) via three different sizes of optical fibers at five energy intensities. The simulation results clearly demonstrate that a 0.5 second INS pulse train induces an increase followed by an immediate drop in temperature at stimulation offset. The delivery of multiple pulse trains with 2.5 s interstimulus interval (ISI) leads to rising temperatures that plateau. Both thermometry and modeling results show that, using parameters that are commonly used in biological applications (200 µm diameter fiber, 0.1-1.0 J/cm2), the final temperature increase at the end of the 60 sec stimuli duration does not exceed 1°C with stimulation values of 0.1-0.5 J/cm2 and does not exceed 2°C with stimulation values of up to 1.0 J/cm2. Thus, the maximum temperature rise is consistent with the thermal damage threshold reported in previous studies. This study provides a quantitative evaluation of the temperature changes induced by INS, suggesting that existing practices pose minimal major safety concerns for biological tissues.

School Choice, Socioeconomic Status, and Stratified Enrollment in Urban Districts: Evidence From Detroit

Researchers and policymakers have often debated whether urban schools of choice enroll students who are relatively advantaged compared to their traditional public school peers. Existing research has not adequately answered this question due to a reliance on inadequate quantitative measures of socioeconomic status and an emphasis on differences between racial or class groups rather than within them. This mixed-methods study contributes new evidence based on novel survey data and interviews with parents and educational leaders in Detroit. Detroit charter schools enroll significantly fewer students living in deep poverty than neighborhood schools, and selective schools enroll a distinctly advantaged population. These stratified enrollment patterns result from differences in geographic constraints, the influence of social networks, school type reputations, and school practices.

The wellbeing shelf: A mixed methods study exploring the impact of a resilience web resource for first year nursing and midwifery students

BackgroundNurturing a resilient nursing and midwifery workforce is vital for the National Health Service's sustainability. Higher Education Institutions (HEIs) must support students, given the challenges and attrition rates. Nursing and midwifery education uniquely balances tuition and placements, posing challenges, especially for first-year students, who face stressors including lack of familiarity, knowledge gaps, and emotional exposure. ObjectivesThis study aimed to introduce and evaluate a co-designed web-based intervention called ‘The Wellbeing Shelf’ to enhance resilience among first-year nursing and midwifery students. DesignAn exploratory mixed methods approach was employed, combining quantitative pre- and post-intervention questionnaires and qualitative focus groups. Settings and participantsThe study involved 353 first-year nursing and midwifery students at Queen's University Belfast. Methods‘The Wellbeing Shelf’ was developed through co-design workshops. Quantitative measures included the Connor Davidson Resilience Scale (CD-RISC) and the Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS). Qualitative data were collected through focus group interviews. ResultsQuantitative data showed a decrease in both resilience and wellbeing scores over time. The CD-RISC scores decreased significantly from Time 1 to Time 3. Qualitative findings revealed three themes: “Acquiring” knowledge about wellbeing, “Actioning” self-care strategies, and “Advocating” for self-care among peers and family. ConclusionsThe study introduced ‘The Wellbeing Shelf’ as a resource to enhance resilience among nursing and midwifery students. Whilst the resource offered a variety of activities and fostered a sense of belonging, challenges in resource accessibility and student confidence were identified. The study also highlighted the importance of students advocating for self-care practices. Despite the resource's introduction, resilience and wellbeing scores decreased over time, suggesting a need for further research and potentially a control group. Understanding the initial lower resilience of nursing and midwifery students is crucial for future interventions in this high-demand program.

Construction of a Colorimetric and Near-Infrared Ratiometric Fluorescent Sensor and Portable Sensing System for On-Site Quantitative Measurement of Sulfite in Food.

Sulfites play imperative roles in food crops and food products, serving as sulfur nutrients for food crops and as food additives in various foods. It is necessary to develop an effective method for the on-site quantification of sulfites in food samples. Here, 7-(diethylamino) quinoline is used as a fluorescent group and electron donor, alongside the pyridinium salt group as an electron acceptor and the C=C bond as the sulfite-specific recognition group. We present a novel fluorescent sensor based on a mechanism that modulates the efficiency of intramolecular charge transfer (ICT), CY, for on-site quantitative measurement of sulfite in food. The fluorescent sensor itself exhibited fluorescence in the near-infrared light (NIR) region, effectively minimizing the interference of background fluorescence in food samples. Upon exposure to sulfite, the sensor CY displayed a ratiometric fluorescence response (I447/I692) with a high sensitivity (LOD = 0.061 μM), enabling accurate quantitative measurements in complex food environments. Moreover, sensor CY also displayed a colorimetric response to sulfite, making sensor CY measure sulfite in both fluorescence and colorimetric dual-signal modes. Sensor CY has been utilized for quantitatively measuring sulfite in red wine and sugar with recoveries between 99.65% and 101.90%, and the RSD was below 4.0%. The sulfite concentrations in live cells and zebrafish were also monitored via fluorescence imaging. Moreover, the sulfite assimilated by lettuce leaves was monitored, and the results demonstrated that excessive sulfite in leaf tissue could lead to leaf tissue damage. In addition, the sulfate-transformed sulfite in lettuce stem tissue was tracked, providing valuable insights for evaluating sulfur nutrients in food crops. More importantly, to accomplish the on-site quantitative measurement of sulfite in food samples, a portable sensing system was prepared. Sensor CY and the portable sensing system were successfully used for the on-site quantitative measurement of sulfite in food.

Fuzzy Testing Model Built on Confidence Interval of Process Capability Index CPMK

A variety of process capability indices are applied to the quantitative measurement of the potential and performance of processes in manufacturing. As it is easy to understand the formulae of these indices, this method is easy to apply. Furthermore, a process capability index is frequently utilized by a manufacturer to gauge the quality of a process. This index can be utilized by not only an internal process engineer to assess the quality of the process but also as a communication tool for an external sales department. When the manufacturing process deviates from the target value T, the process capability index CPMK can be quickly detected, which is conducive to the promotion of smart manufacturing. Therefore, this study applied the index CPMK as an evaluation tool for process quality. As noted by some studies, process capability indices have unknown parameters and therefore must be estimated from sample data. Additionally, numerous studies have addressed that it is essential for companies to establish a rapid response mechanism, as they wish to make decisions quickly when using a small sample size. Considering the small sample size, this study proposed a 100 (1 − α)% confidence interval for the process capability index CPMK based on suggestions from previous studies. Subsequently, this study built a fuzzy testing model on the 100 (1 − α)% confidence interval for the process capability index CPMK. This fuzzy testing model can help enterprises make decisions rapidly with a small sample size, meeting their expectation of having a rapid response mechanism.

Micron-sized fiber diamond probe for quantum precision measurement of microwave magnetic field

Abstract We present a quantitative measurement of the horizontal component of the microwave magnetic field of a coplanar waveguide using a quantum diamond probe in fiber format. The measurement results are compared in detail with simulation, showing a good consistence. Further simulation shows fiber diamond probe brings negligible disturbance to the field under measurement compared to bulk diamond. This method will find important applications ranging from electromagnetic compatibility test and failure analysis of high frequency and high complexity integrated circuits.

Extraction and Purification of Squalene from Virgin Olive Oil via Catalytic Transesterification and Molecular Distillation

Squalene, a highly valuable compound abundant in various natural sources, shows great potential in pharmaceutical, cosmetic, and nutraceutical applications. This research article outlines a comprehensive methodology for extracting and purifying squalene from virgin olive oil, a rich source of the compound. The extraction process begins with degumming, which involves heating the olive oil to 60-70°C to reduce viscosity, followed by the addition of 2-3% warm water to hydrate phospholipids. Food-grade phosphoric acid is then added to react with the phospholipids, forming precipitates. The mixture is stirred for 20-30 minutes and allowed to rest for an additional 20-30 minutes, enabling impurities to settle. The upper layer of degummed oil is separated via decantation or centrifugation and washed with warm water for pH adjustment. Next, transesterification is performed by mixing 100 ml of virgin olive oil with 25% methanol (w/w) and a catalyst (0.5% sodium methoxide or PTSA), and heating the mixture to 80-90°C under reflux for 1-2 hours. Following transesterification, the solvent and acetone are distilled out, and acetone precipitation is repeated 2-3 times to remove unsaponified matter, which is then filtered and evaporated. The concentrated oil undergoes molecular distillation at 180°C and 0.0033 bar pressure for 1 hour, yielding the distillate and residue for further analysis. Qualitative analysis using Thin Layer Chromatography (TLC) involves Merck TLC plates with silica gel 60 F254 and a hexane: chloroform (9:1) mobile phase. Spots are developed with a 10% HCl solution, confirming the presence of squalene with an RF value of 0.93. Quantitative analysis via High-Performance Thin-Layer Chromatography (HPTLC) employs Merck TLC plates with cyclohexane as the mobile phase and CAMAG at 254 nm and 366 nm wavelengths, revealing a squalene purity of 67% and a recovery rate of 69.8%. The initial purification through transesterification facilitated the conversion of ester groups, yielding squalene-rich fractions, while acetone precipitation effectively removed saponified matter. Molecular distillation further enhanced squalene purity. TLC analysis confirmed the qualitative presence of squalene, and HPTLC provided precise quantitative measurements. The obtained squalene purity of 67% significantly enriches the initial content in virgin olive oil, though further optimization could enhance purity and yield. Complementary techniques like GC-MS or HPLC could validate the purification process. This study presents an efficient, replicable procedure for extracting and purifying squalene from virgin olive oil, with significant implications for pharmaceutical, cosmetic, and nutraceutical industries. The findings support a sustainable and ethical shift towards vegetable-derived squalene, meeting market demands while ensuring high-quality production.

Quantitative measurement of spatial distribution of effective refractive index induced by local electron concentration at a nano slit

Abstract Surface plasmon polaritons (SPPs) have found their key applications in high-sensitivity biomolecular detection and integrated photonic devices for optical communication via light manipulation at nanostructures. Despite their broad utility, SPPs are known to be accompanied by other complex near-field propagation modes, such as quasi-cylindrical waves (QCWs) and composite diffracted evanescent waves (CDEWs), whose electromagnetic and quantum propagation effects have not been comprehensively understood especially regarding their mutual interaction with SPPs. In this study, we addressed this complexity by employing a nano groove structure and a high-stability broadband femtosecond laser as a light source, the spatial phase distribution around the nano slit edge was measured with relative stability of a 4.6 × 10−11 at an averaging time of 0.01 s. Through this spatial phase spectrum, we precisely measured the nonlinear distribution of effective refractive index changes with an amplitude of 10−2 refractive index units at the edge of the nano slit–groove structure. These results reveal that the near-field effects on local electron concentration induced by nanostructure’s discontinuity can be quantitatively measured, which can contribute to a deeper understanding of SPP phenomena in nanostructures for the optimal design and utilization of the SPP effects in diverse nano-plasmonic applications.

"Broken fragments or a breathtaking mosaic": A mixed methods study of self-reported attributes and aspirations of siblings of individuals with and without neurodevelopmental conditions.

Siblings of individuals with neurodevelopmental conditions (NDCs) experience distinct challenges and have unique strengths compared to siblings of individuals without NDCs. The present study examined attributes and aspirations of siblings of individuals with and without neurodevelopmental conditions, and analyzed the association between qualitative responses and quantitative measures of growth mindset, positive and negative valence, and mental health diagnoses. A novel mixed methods thematic analysis was employed to explore the experiences of 166 siblings (75 NDC and 91 controls, aged 14-26, 66.27% female) completing an online survey as part of a larger study on sibling mental health. The overarching theme described The Process of Self-Actualization and Integration, reflecting the journey siblings undergo in seeking to understand themselves and others amidst psychological challenges. It encompassed three subthemes: Personal Growth and Identity Formation; Connection and Belonginess; and Societal Perspective and Global Consciousness. Qualitative responses were analyzed within a Research Domain Criteria (RDoC) framework, and associations between phenomenology and mental health diagnoses examined. NDC siblings had higher negative valence and lower positive valence embedded in their responses, and quantitatively lower self-reported growth mindset (i.e., beliefs about the capacity for personal growth), compared to control siblings, which correlated with self-reported mental health diagnoses. Findings suggest clinical practice may focus on optimizing self-identified strengths and offer opportunities for self-actualization of hopes and ambitions, while providing support for families to attenuate bioecological factors impacting mental health.

Association between comorbidity clusters and mortality in patients with cancer: A machine learning analysis of data from the US National Health and Nutrition Examination Survey 1999–2018.

11132 Background: Multimorbidity is common among patients with cancer; however, research on cancer prognosis has predominantly focused on cancers in isolation. This study identified comorbidity clusters among patients with cancer using machine learning and examine their associations with survival outcomes in a nationally representative sample of the US. Methods: This study used 10 survey cycles of the National Health and Nutrition Examination Survey from 1999 to 2018. Participants aged ≥20 years with a self-reported history of cancer were included. Comorbidities were ascertained through self-reports and quantitative measurements. Machine learning techniques, including Bernoulli mixture model and partition-based methods, were used to identify comorbidity clusters. Cox proportional hazards models were used to analyze the associations between comorbidity clusters and mortality outcomes, including all-cause mortality and cause-specific mortality (cancer, cardiovascular disease [CVD], and respiratory diseases), adjusting for relevant covariates. Results: The study included 4,390 participants. Four comorbidity clusters were identified: Low Comorbidity, Metabolic, CVD, and Respiratory. After adjusting for confounders, participants in the Respiratory Cluster had the highest risk of all-cause mortality (adjusted hazard ratio[aHR]=1.62, 95% confidence interval [CI]=1.26-2.08, p<0.001), followed by the CVD Cluster (aHR=1.50, 95%CI = 1.26-1.80, p<0.001) and the Metabolic Cluster (aHR=1.15, 95%CI=1.02-1.29, p=0.03) compared to the Low Comorbidity Cluster. The Metabolic, CVD, and Respiratory clusters were associated with higher risks of cardiovascular disease-related mortality (aHR=1.48-3.05, p<0.003), but no significant differences in cancer mortality were observed among the clusters. The effects of comorbidity clusters on all-cause mortality were modified by income-to-poverty ratio ( p for interaction=0.04), diet quality ( p for interaction=0.02), time since cancer diagnosis ( p for interaction=0.009), and cancer prognosis ( p for interaction=0.005). Conclusions: High comorbidity burden clusters showed increased all-cause and CVD-related mortality. Moreover, diet quality and socioeconomic status modified these associations. Machine learning approaches can provide valuable insights into complex multimorbidity profiles in patients with cancer. Further research is needed to deepen understanding of the relationships between multimorbidity, mortality, and cancer-specific outcomes.

The anisotropic and region-dependent mechanical response of wrap-around tendons under tensile, compressive and combined multiaxial loads

The present work reports on the multiaxial region and orientation-dependent mechanical properties of two porcine wrap-around tendons under tensile, compressive and combined loads based on an extensive study with n=175 samples. The results provide a detailed dataset of the anisotropic tensile and compressive longitudinal properties and document a pronounced tension-compression asymmetry. Motivated by the physiological loading conditions of these tendons, which include transversal compression at bony abutments in addition to longitudinal tension, we systematically investigated the change in axial tension when the tendon is compressed transversally along one or both perpendicular directions. The results reveal that the transversal compression can increase axial tension (proximal-distal direction) in both cases to orders of 30%, yet by a larger amount in the first case (transversal compression in anterior-posterior direction), which seems to be more relevant for wrap-around tendons in-vivo. These quantitative measurements are in line with earlier findings on auxetic properties of tendon tissue, but show for the first time the influence of this property on the stress response of the tendon, and may thus reveal an important functional principle within these essential elements of force transmission in the body. Statement of significanceThe work reports for the first time on multiaxial region and orientation-dependent mechanical properties of wrap-around tendons under various loads. The results indicate that differences in the mechanical properties exist between zones that are predominantly in a uniaxial tensile state and those that experience complex load states. The observed counterintuitive increase of the axial tension upon lateral compression points at auxetic properties of the tendon tissue which may be pivotal for the function of the tendon as an element of the musculoskeletal system. It suggests that the tendon’s performance in transmitting forces is not diminished but enhanced when the action line is deflected by a bony pulley around which the tendon wraps, representing an important functional principle of tendon tissue.

Rates and predictors of reimplantation of matrix-induced autologous chondrocyte implantation following first stage cartilage harvest: A cohort study

PurposeTo assess the reimplantation rate and predictors of patients requiring second-staged matrix-induced autologous chondrocyte implantation (MACI) reimplantation after initial first stage cartilage biopsy. MethodsA retrospective review was performed from 2018 to 2022 among patients who underwent only phase I MACI biopsy procedure (biopsy group) or both phase I with transition to phase II implantation of chondrocytes (implantation group) at a single tertiary center. Demographic, qualitative, and quantitative measurements were recorded, and univariate and multivariate regression analysis was performed to assess predictors of ultimately requiring second stage MACI implantation. ResultsA total of 71 patients (51% female, age 27.7 ± 10.6 years (range 12–50)) were included in this study. Eventually, 25 of 71 patients (35.2%) experienced persistence of symptoms after initial MACI biopsy and other concomitant procedures, requiring second-stage implantation. Univariate analysis showed the implantation group compared to the biopsy group had a greater lesion size (5.2 cm2 ± 3.3 vs. 3.3 cm2 ± 1.4, p = 0.024), a higher proportion patients ≥ 26 years of age (76% vs. 43%, p = 0.009), a medial femoral condyle lesion more commonly (33% vs 11%, p = 0.005), were more often female (72% vs. 39%, p = 0.008), and had less often soft tissue repair at time of biopsy (32% vs. 61%, p = 0.020). Backward multivariate logistic regression analysis revealed that size of the lesion (OR 1.43, p = 0.031) and age ≥ 26 years old at time of biopsy (OR 3.55, p = 0.042) were independent predictors of not responding to initial surgery and requiring implantation surgery. ConclusionThis study found that 35% of patients undergoing MACI phase I biopsy harvest eventually required autologous implantation. Independent risk factors for progressing to implantation after failed initial surgery were larger defect size and older age.Level of Evidence: III, Cohort Study.

Consideration of quantitative risk reduction and risk achievement measures in safe NPP design

Abstract In the models developed by probabilistic safety analyses (PSA) and in their applications associated with nuclear power plants (NPPs), the risk importance of a particular feature can be, most generally, divided into two categories: importance with respect to the risk-increase potential and importance with respect to the risk-decrease potential. A representative measure of the first category is risk achievement worth (RAW), while a representative measure of the second category is risk reduction worth (RRW). The present paper discusses the use of RAW and RRW in achieving safe design and points out some implications of their mutual dependency on the selection of a risk-reduction strategy. A simple example is provided to illustrate the differences between the two basic strategies and point out to the main issues and conclusions.