The Influence of Family Adversities on Longitudinal Changes in Physical Inactivity Among Korean Adolescents During the COVID-19 Pandemic.

Objectives: Lack of physical activity has a critical effect on the physical and mental health of adolescents. This study examined the influence of family adversities on the longitudinal changes in physical inactivity among adolescents during the coronavirus disease 2019 (COVID-19) pandemic. Methods: The study used multi-wave data from the Korean Children and Youth Panel Survey, including 2590 Korean adolescents aged 12-14 years. The longitudinal trajectory of physical inactivity among adolescents and the effects of related factors were estimated using a latent growth modeling method. Results: Our results revealed a significant increase in physical inactivity among adolescents over time. At the onset of the pandemic, approximately one-seventh of Korean middle schoolers reported a lack of physical activity. However, 3 years later, during the quarantine, nearly one-fifth of these adolescents reported a significant increase in their physical inactivity. Initially, low level parental education was predictive of adolescents' physical inactivity, but this effect diminished over time, becoming statistically insignificant by the end of the 3-year period. Moreover, the increase in physical inactivity over the 3 years was significantly influenced by parental rejection. Conclusions: These findings suggest that adolescents who experience parental rejection are more likely to report an increase in sedentary behaviors in contexts such as the COVID-19 pandemic.

Understanding the Behavioral Health Needs of Hospice Patients and Their Family Caregivers: Perspectives of Hospice Medical Directors.

BACKGROUND: Behavioral health disorders are common among patients and caregivers in the hospice setting. Yet, limited data exist regarding what hospice providers perceive as the most common and challenging behavioral health disorders they encounter and how they manage these issues in practice. OBJECTIVE: To characterize the perspectives of hospice medical directors (HMDs) on addressing the behavioral health challenges when caring for patients enrolled in home hospice care and their family caregivers. METHODS: Semistructured interviews with seventeen certified HMDs were conducted. Data were analyzed using thematic analysis. RESULTS: Many HMDs agreed that delivering high-quality behavioral health care is a tenet for good end-of-life (EoL) care. HMDs shared that depression and anxiety were the most common behavioral health challenges they encountered, while among caregivers, substance use disorder was the most challenging. Participants mentioned that nurses and social workers played a vital role in detecting and managing behavioral health problems. HMDs also stated that providing additional training for frontline staff and incorporating behavioral health experts are potential solutions to help address current challenges. CONCLUSION: HMDs emphasized the importance of addressing behavioral health challenges among patients and caregivers to provide effective end-of-life care. Future studies should examine the viewpoints of additional key stakeholder groups (e.g., hospice interdisciplinary team members, family caregivers) and confirm them in quantitative studies. Designing and implementing evidence-based assessments and interventions to improve behavioral health care by addressing anxiety, depression, and caregiver substance use disorders is essential to improving care and care outcomes in the hospice setting.

Antimicrobial effect of two fluoride-releasing adhesive tapes on Streptococcus mutans biofilm.

Fluoride-releasing adhesive tapes have been developed as a new fluoride delivery agent. However, application as caries prevention agents remains underexplored. This study aimed at evaluating the antimicrobial activity of two fluoride-releasing adhesive tapes against S. mutans biofilm. Two polyvinyl alcohol (PVA) tapes were investigated: (i) a fluoride-PVA (F-PVA) tape, (ii) a pullulan incorporated F-PVA (PF-PVA) tape. S. mutan strains were cultured and treated with the tapes. Antimicrobial effects were evaluated using the agar diffusion test, field-emission scanning electron microscopy (FE-SEM), and confocal laser scanning microscopy (CLSM). F-PVA tapes showed higher inhibition-zone diameters than PF-PVA at 48 h and 72 h. However, there were no significant differences (p > 0.05) between the effects of F-PVA and PF-PVA. The bio-volume of S. mutans and extracellular polymeric substances significantly decreased in the F-PVA tapes than in the PF-PVA tapes (p < 0.05). FE-SEM micrographs revealed less S. mutans colonization in F-PVA. F-PVA exhibited better antimicrobial activity against S. mutans than PF-PVA.

Understanding the home hospice experience of Puerto Rican caregivers.

Hospice use among Hispanic Medicare beneficiaries has declined in the last few years, and Hispanic caregivers have reported insufficient support around the emotional and spiritual aspects of care. Understanding the home hospice experience of Puerto Rican (PR) caregivers can yield insight into ways to improve hospice participation and quality of care for the Hispanic population. This exploratory study utilizes qualitative methods to identify PR caregivers' experience in the setting of home hospice care. Data from interviews with eight (n=8) bereaved PR caregivers of patients who received home hospice care were qualitatively analyzed. Participants were mostly well-educated (n=6/8) female caregivers caring for their parent (n=7/8) with mean age of 57 [standard deviation (SD) =13] years. Emerging domains from the study included (I) symptom management; (II) cultural and religious values; and (III) interaction with hospice providers. Caregivers found managing patients' loss of appetite, pain, anxiety, and confusion to be challenging. They identified family-centered values and religious support as culturally important, which manifested as the need for frequent communication from hospice providers and increased support and education at the end-of-life. Culturally tailored interventions that focus on managing symptoms, tailoring care to support family-centered values, integrating religious officials representative of the patient's beliefs into the hospice team, and communicating effectively with providers may reduce the burden experienced by PR caregivers in home hospice and improve outcomes for patients and caregivers. Additional research will aid in the development of evidence-based intervention and policies urging healthcare providers to offer culturally appropriate hospice care and resources to this population.

Pilot Testing Educational Videos for Black Caregivers Receiving Home Hospice Care.

Black caregivers face distinct challenges in symptom management when providing end-of-life care. Educational interventions may improve caregiver preparedness and competency by providing information on symptom management. This study pilot tested 4 culturally tailored caregiver educational videos about symptom management for Black caregivers receiving home hospice care at a large, urban, nonprofit hospice organization to determine feasibility and acceptability, along with their potential impact on caregiver outcomes. All participants (N = 10) agreed to watch the 4 videos and found the videos to be helpful; 90% (n = 9) shared that they would recommend them to other Black caregivers receiving home hospice care. Total preparedness scores increased from a mean score of 23.5 preintervention to 28.3 postintervention. Caregiver competency scores increased from 13.8 at preintervention to 14.3 at postintervention. Caregivers' comfort and knowledge scores increased from preintervention to postintervention for all 7 end-of-life topics presented in the 4 videos. This study found that it was feasible and acceptable to show Black caregivers culturally tailored educational videos related to issues regarding symptom management. Many found the videos to be helpful and the topics to be relatable. There were trends toward improvement in preparedness and competency. Future studies examining efficacy are needed to determine the impact of this intervention.

An Ultramicroporous Graphene-Based 3D Structure Derived from Cellulose-Based Biomass for High-Performance CO2 Capture.

The use of powered activated carbon is often limited by inconsistent particle sizes and porosities, leading to reduced adsorption efficiencies. In this study, we demonstrated a practical and environmentally friendly method for creating a 3D graphene nanostructure with highly uniform ultramicropores from wood-based biomass through a series of delignification, carbonization, and activation processes. In addition, we evaluated the capture characteristics of this structure for CO2, CH4, and N2 gases as well as its selectivity for binary-mixture gases. Based on textural and chemical analyses, the delignified monolith had a lamellar structure interconnected by cellulose-based fibers. Interestingly, applying the KOH vapor activation technique solely to the delignified samples led to the formation of a monolithic 3D network composed of interconnected graphene sheets with a high degree of crystallinity. Especially, the Act. 1000 sample exhibited a specific surface area of 1480 m2/g and a considerable pore volume of 0.581 cm3/g, featuring consistently uniform ultramicropores over 90% in the range of 3.5-11 Å. The monolithic graphene-based samples, predominantly composed of ultramicropores, demonstrated a notably heightened capture capacity of 6.934 mol/kg at 110 kPa for CO2, along with favorable selectivity within binary gas mixtures (CO2/N2, CO2/CH4, and CO2/CH4). Our findings suggest that this biomass-derived 3D structure has the potential to serve as a monolithic adsorbent in gas separation applications.

Sex Differences in Heart Rate Variability and Vascular Function Following High-Intensity Interval Training in Young Adults.

High-intensityintervaltraining (HIIT) issuperiortoothertrainingstrategies in both male andfemalehealthyindividuals. Understanding sex-specificdifferences in cardiac auto-regulation maycontributetothe optimal trainingstrategiesfor HIIT. The presentstudyaimedtoidentifysexdifferences in heart rate variability (HRV) andvascularfunctionfollowing HIIT in youngadults. Twenty-fourphysicallyactiveyoung male andfemaleadults (M: 12, F: 12, age: 19.5 yr, BMI: 22.1 kg·m-2) volunteeredtoparticipate in thestudy. Participantsperformed 10 boutsof HIIT including 20 s of high-intensitycycling at 115-130% Wmaxfollowedby 100 s ofrecovery. The cardiac auto-regulationsincluding HRV andvascularfunctionweremeasured at five different time points. The R-R interval, rMSSD, and SDNN wererecoveredfaster in malesthan in females after 15 min of HIIT. Thereweresexdifferences in theautonomicnervoussystemwhereln LF andln HF activitiesalongwithsympathovagalbalance (ln LF/HF) weregreater in femalescomparedwithmalesimmediatelyand 15 min after HIIT. However, nosignificantdifferences in bloodpressureand brachial-ankle pulse wavevelocitywereobservedbetween male andfemaleparticipants. Overall, HRV was moreactivated in femalesthan in malesfollowing HIIT, but theacuteresponse in vascularfunction was not different betweensexes. In futurestudies, sex-specificadaptationsofcardiacautoregulationfollowingrepeated HIIT mayneedtobeperformed.

Interventions for Family Caregivers of Patients Receiving Palliative/Hospice Care at Home: A Scoping Review.

There is a need for understanding the breadth of interventions for caregivers of individuals receiving hospice care at home, given the important role caregivers play in caring and the negative outcomes (e.g., depression) associated with their caregiving. Previous reviews were limited in scope to certain types of interventions or patient populations. The objective of this scoping review was to broadly examine the interventions targeting caregivers who provide care to terminally ill patients in home, with the purpose of (1) describing the characteristics of these interventions, (2) discussing key outcomes, limitations, and knowledge gaps, (3) highlighting intervention strengths, and (4) proposing future research directions. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Intervention studies that met the inclusion criteria and that were published up until October 2022 were obtained from the following databases: Ovid MEDLINE, Ovid EMBASE, CINAHL (EBSCO), and The Cochrane Library (Wiley). We analyzed 76 studies describing 55 unique interventions that took place in 14 countries. Interventions were largely delivered by nurses (n = 18, 24%), followed by an interdisciplinary team (n = 16, 21%), a health care provider (n = 10, 13%), research staff (n = 10, 13%), social worker (n = 5, 7%), and others (n = 11, 15%). Six interventions (8%) were self-administered. The most measured outcome was caregiver quality of life (n = 20, 26%), followed by anxiety (n = 18, 24%) and burden (n = 15, 20%). Missing data on patient and caregiver characteristics (i.e., age, gender) were common, and less than half of studies (n = 32, 42%) reported race/ethnicity data. Our review highlighted the current state of interventions for caregivers of patients receiving hospice care at home. Many of the interventions were in the early phases of development, raising the need for future studies to look at efficacy, effectiveness, and the ability to implement interventions in real-world settings.

Assessing the feasibility, acceptability, and preliminary efficacy of a novel symptom management care delivery intervention for caregivers receiving home hospice care: The I-HoME protocol.

BACKGROUND: Terminally ill patients experience high symptom burden at the end of life (EoL), even when receiving hospice care. In the U.S., family caregivers play a critical role in managing symptoms experienced by patients receiving home hospice services. Yet, most caregivers don't receive sufficient support or formal training in symptom management. Therefore, providing additional visits and education to caregivers could potentially improve outcomes for both patient and caregiver. In response, we developed the Improving Home hospice Management of End-of-life issues through technology (I-HoME) intervention, a program designed for family caregivers of home hospice patients. This paper describes the intervention, study design, and protocol used to evaluate the intervention. METHODS: The I-HoME study is a pilot randomized controlled trial aimed at reducing patient symptom burden through weekly tele-visits and education videos to benefit the patient's family caregiver. One hundred caregivers will be randomized to hospice care with (n = 50) or without (n = 50) the I-HoME intervention. Primary outcomes include intervention feasibility (e.g., accrual, attrition, use of the intervention) and acceptability (e.g., caregivers' comfort accessing the tele-visits and satisfaction). We will also examine preliminary efficacy using validated patient symptom burden and caregiver outcome measures (i.e., burden, depression, anxiety, satisfaction). CONCLUSION: The trial is evaluating a novel symptom management intervention that supports caregivers of patients receiving home hospice services. The intervention employs a multi-pronged approach that provides needed services at a time when close contact and support is crucial. This research could lead to advances in how care gets delivered in the home hospice setting.

Recruitment of family caregivers of persons with dementia: Lessons learned from a pilot randomized controlled trial.

Family caregivers play an essential role in supporting the health and well-being of older adults with dementia, a population projected to increase rapidly over the coming decades. Enrolling caregivers of people with dementia (PWD) in research studies is vital to generating the evidence necessary to support broader implementation of efficacious intervention programs in real-world care delivery, but a range of challenges impede recruitment and enrollment of sufficiently large and representative sample sizes. In this article, we characterize the challenges and lessons learned from recruiting caregivers of PWD to participate in a pilot randomized control trial. We utilize Bronfenbrenner's ecological model to categorize the challenges into three levels: individual (i.e., understanding caregivers' time constraints and motivations), community (i.e., reaching underrepresented populations and accessing caregiver support groups) and institutional (i.e., obtaining informed consent and navigating research registries). We found that establishing rapport and maintaining flexibility with participants was crucial for motivating individuals to enroll in our study. Building trust with local communities by collaborating with support group leaders, appointing a co-investigator who is already embedded within a given community, and establishing equitable partnerships with organizations increased recruitment rates. At the institutional level, engaging experts in regulatory affairs and geriatrics may help overcome barriers in obtaining approval from institutional review boards. We also recommend using research registries of individuals who offer their contact information to researchers. The lessons learned from our research-including the challenges and potential solutions to overcome them-may promote more effective and efficient recruitment in future research.

Black Caregivers' Symptom Management, Cultural, and Religious Experiences With Home Hospice Care.

CONTEXT: Informal Black or African American (Black/AA) caregivers are at high risk for caregiver burden due to both greater caregiving responsibilities and unmet needs. However, there has been minimal research on the challenges Black/AA caregivers face after hospice enrollment. OBJECTIVES: This study seeks to address this knowledge gap by applying qualitative methods to understand Black/AA caregivers' experiences around symptom management, cultural, and religious challenges during home hospice care. METHODS: Data from small group discussions with 11 bereaved Black/AA caregivers of patients who received home hospice care were qualitatively analyzed. RESULTS: Caregivers struggled most with managing patients' pain, lack of appetite, and decline near end of life (EoL). Cultural needs (e.g., knowing their language, having familiarity with foods) were perceived as not on top of mind for many Black/AA caregivers. However, there was a concern of stigma around mental health preventing care recipients from sharing their mental health concerns and seeking resources. Many caregivers relied on their personal religious networks rather than services provided by hospice chaplains. Lastly, caregivers reported increased burden during this phase of caregiving but were satisfied with the overall hospice experience. CONCLUSION: Our results suggest that tailored approaches that target mental health stigma in the Black/AA community and reduce caregiver distress around end of life symptoms may improve hospice outcomes among Black/AA hospice caregivers. Hospice spiritual services should consider offering services complementary to caregivers' existing religious networks. Future qualitative and quantitative studies should examine the clinical implications of these results in terms of patient, caregiver, and hospice outcomes.

Feasibility and measurement stability of smartwatch-based cuffless blood pressure monitoring: A real-world prospective observational study.

Cuffless wearable devices are currently being developed for long-term monitoring of blood pressure (BP) in patients with hypertension and in apparently healthy people. This study evaluated the feasibility and measurement stability of smartwatch-based cuffless BP monitoring in real-world conditions. Users of the first smartwatch-based cuffless BP monitor approved in Korea (Samsung Galaxy Watch) were invited to upload their data from using the device for 4 weeks post calibration. A total of 760 participants (mean age 43.7 ± 11.9, 80.3% men) provided 35,797 BP readings (average monitoring 22 ± 4 days [SD]; average readings 47 ± 42 per participant [median 36]). Each participant obtained 1.5 ± 1.3 readings/day and 19.7% of the participants obtained measurements every day. BP showed considerable variability, mainly depending on the day and time of the measurement. There was a trend towards higher BP levels on Mondays than on other days of the week and on workdays than in weekends. BP readings taken between 00:00 and 04:00 tended to be the lowest, whereas those between 12:00 and 16:00 the highest. The average pre-post calibration error for systolic BP (difference in 7-day BP before and after calibration), was 6.8 ± 5.6 mmHg, and was increased with higher systolic BP levels before calibration. Smartwatch-based cuffless BP monitoring is feasible for out-of-office monitoring in the real-world setting. The stability of BP measurement post calibration and the standardization and optimal time interval for recalibration need further investigation.

What Motivates Physicians to Address Caregiver Needs? The Role of Experiential Similarity.

Despite the significant stress of family caregiving, caregivers' needs and risks are often overlooked in healthcare settings. This study examined the factors associated with primary care physicians' perceived responsibility to identify and address caregiver needs and risks. Using a national random sample of U.S. primary care physicians (N = 106), multivariable logistic regression analyses were conducted to examine associations of physicians' perceived responsibility to assess caregivers' needs with experiential similarity (personal experience with caregiving), structural similarity (being older and female), and secondary exposure variables (time seeing older adults in the outpatient setting). Most (76.5%) physicians felt responsible for identifying caregivers' needs and risks. In multivariable models, physicians who had personal experience with caregiving were four times more likely than those without it to feel responsible for identifying caregivers' needs and risks and assessing caregivers' mental health concerns. Thus, physicians may benefit from educational interventions that immerse them in caregivers' lived experiences.

High-Performance Electrochromic Devices Based on Size-Controlled 2D WO3 Nanosheets Prepared Using the Intercalation Method.

It is difficult to obtain ultrathin two-dimensional (2D) tungsten trioxide (WO3) nanosheets through direct exfoliation from bulk WO3 in solution due to the strong bonding between interlayers. Herein, WO3 nanosheets with controllable sizes were synthesized via K+ intercalation and the exfoliation of WO3 powder using sonication and temperature. Because of the intercalation and expansion in the interlayer distance, the intercalated WO3 could be successfully exfoliated to produce a large quantity of individual 2D WO3 nanosheets in N-methyl-2-pyrrolidone under sonication. The exfoliated ultrathin WO3 nanosheets exhibited better electrochromic performance in an electrochromic device than WO3 powder and exfoliated WO3 without intercalation. In particular, the prepared small WO3 nanosheets exhibited excellent electrochromic properties with a large optical modulation of 41.78% at 700 nm and fast switching behavior times of 9.2 s for bleaching and 10.5 s for coloring. Furthermore, after 1000 cycles, the small WO3 nanosheets still maintained 86% of their initial performance.

Artificial intelligence in urologic oncology: the actual clinical practice results of IBM Watson for Oncology in South Korea.

Background: Artificial intelligence (AI) is changing our life, including the medical field. Repeated machine learning using big data made various fields more predictable and accurate. In medicine, IBM Watson for Oncology (WFO), trained by Memorial Slone Kettering Cancer Center (MSKCC), was first introduced and applied in 14 countries worldwide.Our study was designed to assess the feasibility of WFO in actual clinical practice. We aimed to investigate the concordance rate between WFO and multidisciplinary tumor board (MTB) in Urologic cancer patients. Materials and methods: We reviewed retrospectively collected data for consecutive patients who underwent WFO and MTB simultaneously in the diagnosis of urologic malignancy before determining further treatment between August 2017 and September 2020. We compared the recommendation of the AI system, WFO (IBM Watson Health, Cambridge, MA), with the opinion of MTB for further managing all patients diagnosed with urologic malignancies such as prostate, bladder, and kidney cancer. Results: A total of 55 patients were enrolled in our study. The number of patients with prostate cancer was 48. The number of bladder and kidney cancer patients was 5 and 2, respectively. The overall concordance rate between WFO and MTB was 92.7%. Three patients could not suggest proper treatment options using WFO, and the recommended choice of WFO was not feasible in the Korean Health Insurance Review and Assessment Service. Conclusions: The decision of WFO showed a high concordance rate with a multidisciplinary tumor board for urologic oncology. However, some recommendations of WFO were not feasible in actual practice, and WFO still has some points to improve and modify. Interestingly, applying WFO is likely to facilitate a multidisciplinary team approach.

Vaccines against SARS-CoV-2 variants and future pandemics.

INTRODUCTION: Vaccination continues to be the most effective method for controlling COVID-19 infectious diseases. Nonetheless, SARS-CoV-2 variants continue to evolve and emerge, resulting in significant public concerns worldwide, even after more than 2 years since the COVID-19 pandemic. It is important to better understand how different COVID-19 vaccine platforms work, why SARS-CoV-2 variants continue to emerge, and what options for improving COVID-19 vaccines can be considered to fight against SARS-CoV-2 variants and future pandemics. AREA COVERED: Here, we reviewed the innate immune sensors in the recognition of SARS-CoV-2 virus, innate and adaptive immunity including neutralizing antibodies by different COVID-19 vaccines. Efficacy comparison of the several COVID-19 vaccine platforms approved for use in humans, concerns about SARS-CoV-2 variants and breakthrough infections, and the options for developing future COIVD-19 vaccines were also covered. EXPERT OPINION: Owing to the continuous emergence of novel pathogens and the reemergence of variants, safer and more effective new vaccines are needed. This review also aims to provide the knowledge basis for the development of next-generation COVID-19 and pan-coronavirus vaccines to provide cross-protection against new SARS-CoV-2 variants and future coronavirus pandemics.

High-throughput functional evaluation of human cancer-associated mutations using base editors.

Comprehensive phenotypic characterization of the many mutations found in cancer tissues is one of the biggest challenges in cancer genomics. In this study, we evaluated the functional effects of 29,060 cancer-related transition mutations that result in protein variants on the survival and proliferation of non-tumorigenic lung cells using cytosine and adenine base editors and single guide RNA (sgRNA) libraries. By monitoring base editing efficiencies and outcomes using surrogate target sequences paired with sgRNA-encoding sequences on the lentiviral delivery construct, we identified sgRNAs that induced a single primary protein variant per sgRNA, enabling linking those mutations to the cellular phenotypes caused by base editing. The functions of the vast majority of the protein variants (28,458 variants, 98%) were classified as neutral or likely neutral; only 18 (0.06%) and 157 (0.5%) variants caused outgrowing and likely outgrowing phenotypes, respectively. We expect that our approach can be extended to more variants of unknown significance and other tumor types.

Age-related changes in muscle quality and development of diagnostic cutoff points for myosteatosis in lumbar skeletal muscles measured by CT scan.

BACKGROUND & AIMS: We have sought to develop proper and useful indices for muscle quality measurements other than muscle attenuation (Hounsfield unit; HU) and to determine the diagnostic cutoff points for myosteatosis by using those indices measured at the L3 lumbar vertebrae level by CT scan. METHODS: This cross-sectional analysis included 20,664 healthy adult subjects (12,697 men and 7967 women) who underwent abdominal CT scans. Total abdominal muscle area (TAMA), on the L3 vertebra was demarcated using predetermined thresholds. Intermuscular adipose tissue area (IMAT) and skeletal muscle area (SMA) were measured. SMA was divided into normal attenuation muscle area (NAMA) and low attenuation muscle area (LAMA). Their various indices were calculated. We identified the sex-specific mean values of NAMA, LAMA, IMAT, and their indices and the cutoff points equivalent to the T-scores in the young reference group. RESULTS: The mean values of the NAMA and NAMA indices decreased with age in both sexes, LAMA, IMAT, and their indices showed an increasing tendency with age in both sexes. When using T-score < -2.0 as the cutoff for myosteatosis, the sex-specific cutoff points of NAMA, NAMA/BMI, NAMA/TAMA index, and SMA and TAMA attenuation in men and women were 103.0 and 64.5 cm2, 4.0 and 2.8, 66.4 and 65.1, 40.2 and 39.9 HU, and 34.1 and 33.5 HU, respectively. Using these cutoff points, the prevalence of myosteatosis by NAMA, NAMA/BMI, NAMA/TAMA index, or SMA or TAMA attenuation ranged from 5.9 to 8.8% in men and from 10.2 to 20.5% in women. CONCLUSIONS: The NAMA/TAMA index developed in this study was useful for assessing myosteatosis. This is the first study to report the sex-specific diagnostic cutoff points for myosteatosis of trunk muscles based on T-scores measured by CT scans in healthy population. These diagnostic cutoff points may be particularly useful in the treatment and prevention of sarcopenia and myosteatosis.

Recording of elapsed time and temporal information about biological events using Cas9.

DNA has not been utilized to record temporal information, although DNA has been used to record biological information and to compute mathematical problems. Here, we found that indel generation by Cas9 and guide RNA can occur at steady rates, in contrast to typical dynamic biological reactions, and the accumulated indel frequency can be a function of time. By measuring indel frequencies, we developed a method for recording and measuring absolute time periods over hours to weeks in mammalian cells. These time-recordings were conducted in several cell types, with different promoters and delivery vectors for Cas9, and in both cultured cells and cells of living mice. As applications, we recorded the duration of chemical exposure and the lengths of elapsed time since the onset of biological events (e.g., heat exposure and inflammation). We propose that our systems could serve as synthetic "DNA clocks."

An impedance-based formulation of frequency-domain nonlinearity indicators in finite-amplitude sound propagation.

Since the Morfey-Howell Q/S was introduced as a single-point frequency-domain nonlinearity indicator for propagation of intense broadband noise [AIAA J. 19, 986-992 (1981)], there has been debate about its validity, utility, and interpretation. In this Letter, the generalized Burgers equation is recast in terms of specific acoustic impedance along with linear absorption and dispersion coefficients, normalized quadspectral density (Q/S), and newly proposed normalized cospectral density (C/S). The formulation leads to a rather straightforward interpretation in which Q/S and C/S, respectively, represent the additional absorption and dispersion at a locale, produced by the passage of a finite-amplitude wave.