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Sponges are probably the earliest branching animals and their fossil record dates back to the Precambrian. Identifying their skeletal structure and composition is thus a crucial step in improving our understanding of the early evolution of metazoans. Here, we present the discovery of 505–million-year-old chitin, found in exceptionally well preserved Vauxia gracilenta sponges from the Middle Cambrian Burgess Shale. Our new findings indicate that, given the right fossilization conditions, chitin is stable for much longer than previously suspected. The preservation of chitin in these fossils opens new avenues for research into other ancient fossil groups.

Electroactive polymers (EAPs) are functional materials that, stimulated by an electric field, change its composition or molecular structure so that the material expands, contracts, or bends (Guzmán et al. in J Appl Polymer Sci 112:3284–32931, 2009) and (Rappaport et al. in A glucose fuiel cell for implantable brain machine interfaces, Massachusetts Institute of Technology, Cambridge, 2012). The literature has shown that Chitin and Chitosan are considerably versatile and promising biomaterials to be used as EAPs in medical and biomedical applications as cochlear implant, and due to its chemical structure, is considered a biocompatible, bio-adhesive and biodegradable polymer (Falguni et al. in Proceedings of the 2010 IEEE Students Technology Simposium, IIT Kharagpur, 2010). Their amino and hydroxyl groups can be easily modified by organic (Younes et al. in Process Biochem 47:2032–2039, 2012) or cross-linked reactions, to obtain sophisticated functional medical devices (Wongpaint et al. in Micromol Biosci 5:1001–1012, 2005). This research collaboration aims to prove that Chitosan-based membranes could be synthetized as EAPs; as well as determine that there are useful ionic flow and movement responses on them. Chitosan-based membranes were prepared by the film-casting traditional method, treated with Tetraammineplatinum (II) chloride hydrate and Silver Nitrate by the ion exchange polymer method; and then cast with Sodium and Potassium Chloride as conductive salts. Membranes were tested at different voltages, as well as the chemical tests as FTIR, XRD, TGA and tensile strength and elongation as a function of the treatment applied. Film properties depended on its morphology, which is affected by Molecular Weight, degree of N -acetylation (DDA%), solvent evaporation and free amine regenerating mechanism (Younes et al. in Process Biochem 47:2032–2039, 2012) and (Wongpaint et al. in Micromol Biosci 5:1001–1012, 2005). Samples exhibited good displacement increasing as the applied voltage increased; best tip displacement was located as 17 mm at 7 V; and best theoretical δ value is found at 29.6 mm.

SummaryBy reacting esterification of phenolphtalein with methacrylate chloride, phenolphtalein dimethacrylate was obtained. Based on the results of elemental analysis, FTIR, 1H-NMR and 13C-NMR spectra, the structure of the product was proposed. The dimethacrylate was used as new crosslinker to crosslink poly(methyl methacrylate) (PMMA). The influence of the amount dimethacrylate on the crosslink density and some properties of the crosslinked polymers networks such as swelling, mechanical properties (tensile strength and elongation at break) and thermal stability were examined.

The current study examines daily stress processes as risk factors for comprised mental health in midlife and later life, specifically for gender differences in depression risk. Using data from the Midlife in the United States (MIDUS) study and the National Study of Daily Experiences (NSDE), we examine (1) gender differences in depression; (2) the prospective effects of differential exposure and affective responses on 10-year depression status; (3) gender differences in daily stress-depression links. Furthermore, we explore whether the protective factor of help-seeking behavior moderates the effects of daily stress on depression. Participants included 1289 (mage = 55; SD = 12; range = 34–83; 56% female) individuals who completed the second waves of MIDUS and the 8-day NSDE daily diary protocol and participated in the third wave of MIDUS approximately 10 years later. Respondents completed assessments of depression and their seeking assistance from a psychiatrist, mental health professional, counselor, or religious leader. Covariate-adjusted logistic regression analyses revealed increased odds of depression among women compared to men, but no significant gender difference after taking daily stress into account. Higher levels of stressor exposure, negative affect, and affective reactivity were associated with increased odds of depression for both men and women. Compared to those who did not engage in help-seeking behavior, those who did had significantly greater odds of depression, and there were asymmetric patterns of daily stress effects across groups. These findings highlight differential exposure, negative affect, and affective responses to daily stress as potentially accessible intervention targets for reducing stress in daily life and mitigating longer-term depression risk during mid- and later life.

Personalized approaches to behavior change to improve mental and physical health outcomes are needed. Reducing the intensity, duration, and frequency of stress responses is a mechanism for interventions to improve health behaviors. We developed an ambulatory, dynamic stress measurement approach that can identify personalized stress responses in the moments and contexts in which they occur; we propose that intervening in these stress responses as they arise (ie, just in time; JIT) will result in positive impacts on health behaviors. This study aims to (1) use an experimental medicine approach to evaluate the impact of a smartphone-delivered JIT stress management intervention on the frequency and intensity of person-specific stress responses (ie, stress reactivity, nonrecovery, and pileup); (2) evaluate the impact of the JIT intervention on the enactment of health behaviors in everyday life (physical activity and sleep); and (3) explore whether changes in stress responses mediate the interventions' effects on health behaviors. In a 2-arm phase 2 clinical trial, we will enroll 210 adults in either a JIT stress management intervention or an active control condition. For 4 weeks, participants will complete 8 brief smartphone surveys each day and wear devices to assess sleep and physical activity. After a 1-week run-in period, participants will be randomized into the JIT intervention or an active control condition for 2 weeks. Participants in the JIT intervention will receive very brief stress management activities when reporting greater than typical stress responses, whereas control participants will receive no personalized stress management activities. Participants enrolled in both conditions will engage in self-monitoring for the entire study period and have access to a general stress management education module. Self-report outcomes will be assessed again 1 month after the intervention. We will use mixed-effects models to evaluate differences in person-specific stress responses between the intervention and control groups. We will conduct parallel analyses to evaluate whether the intervention is associated with improvement in health behavior enactment (ie, sleep and physical activity). The Pennsylvania State University Institutional Review Board approved all study procedures (STUDY00012740). Initial participant recruitment for the trial was initiated on August 15, 2022, and enrollment was completed on June 9, 2023. A total of 213 participants were enrolled in this period. Data are currently being processed; analyses have not yet begun. We anticipate that this research will contribute to advancing stress measurement, thereby enhancing understanding of health behavior change mechanisms and, more broadly, providing a conceptual roadmap to advance JIT interventions aimed at improving stress management and health behaviors. Clinicaltrials.gov NCT05502575; https://clinicaltrials.gov/study/NCT05502575. DERR1-10.2196/58985.

Greater perceived control is often associated with better responses to life’s stressors. One reason for this link may be that greater perceived control is related to the ability to resolve these stressful experiences. Using longitudinal data from the National Study of Daily Experiences ( N  = 1766, Mage = 56.25, SD = 12.20, 57% women, 43% men), we examined associations between perceived control over daily stressors and the likelihood of stressor resolution, and how associations varied over a decade. In two waves conducted in ~2005 and ~2015, participants reported perceived control and resolution of their daily stressors across eight consecutive days. Generalized multilevel models adjusted for trends across days and waves, as well as number of stressors, gender, education, and race. People experiencing greater stressor control across the study days were more likely to report stressor resolution (OR = 1.92, 95%CI: 1.74–2.13, p < 0.001). Further, individuals were more likely to report stressor resolution on days when they reported greater control over their stressors than usual (OR = 1.66, 95%CI: 1.57–1.77, p < 0.001). This within-person association increased in magnitude across waves (OR = 1.21, 95%CI: 1.06–1.39, p < 0.01), resulting in a stronger association between stressor control and resolution when individuals were 10 years older (OR = 1.89, 95%CI: 1.69–2.12, p  < 0.001). Results indicate perceived control is a psychosocial correlate of stressor resolution and an important appraisal resource for daily stress processes across the adult lifespan. Using longitudinal data from the National Study of Daily Experiences, results indicate perceived control is a psychosocial correlate of stressor resolution and an important appraisal resource for daily stress processes across the adult lifespan.

In this study, the level of the chemokine CXCL4, which is secreted by plasmacytoid dendritic cells, was elevated in patients with systemic sclerosis and correlated with the presence and progression of complications. Systemic sclerosis (also called scleroderma) is a complex heterogeneous fibrosing autoimmune disorder with an unknown pathogenesis. The way in which its three major pathologic hallmarks — extensive fibrosis, vasculopathy, and immune dysfunction — are interconnected is unknown. Mechanistic understanding is limited, in part, by a lack of animal models and by clinically heterogeneous patient populations. 1 This disorder is classified into two major subtypes on the basis of the extent of cutaneous fibrosis: limited cutaneous and diffuse cutaneous systemic sclerosis. 2 Pulmonary fibrosis and pulmonary arterial hypertension are the two most serious complications — currently the major causes of death among patients . . .

Background: It has recently been reported by several sources that original (i.e., present in vivo ) glioma cell phenotypes or genotypes cannot be maintained in vitro . For example, glioblastoma cell lines presenting EGFR amplification cannot be established. Methods and results: IDH1 sequencing and loss of heterozygosity analysis was performed for 15 surgery samples of astrocytoma and early and late passages of cells derived from those and for 11 archival samples. We were not able to culture tumour cells presenting IDH1 mutations originating from currently proceeded 10 tumours; the same results were observed in 7 samples of archival material. Conclusion: The IDH1 mutation is expected to be almost mutually exclusive with EGFR amplification, so glioma cells with IDH1 mutations seem to represent a new group of tumour cells, which cannot be readily analysed in vitro because of their elimination. The reasons for this intriguing phenomenon should be investigated since its understanding can help to define a new therapeutic approach based on simulating in vivo conditions, responsible for tumour cells elimination in vitro . Moreover, a new model for culturing glioma cells in vitro should be designed since the current one does not provide conditions corresponding to in vivo growth.

Theories of stress, emotion and aging posit age-related decreases in emotional reactivity to stressors. Ecological momentary assessment (EMA) and end-of-day diary (EOD) approaches have been employed to study age differences in stressor-related increases in negative affect, yielding mixed results. Some studies show age benefits, some show age decrements, and others show no difference. Data from 7 independent studies, 5 EMA and 6 EOD, were analyzed to address these inconsistencies. Preliminary analyses of 2 EMA (Study 1: N=240, 14 days, 5 beeps/day, Ages=25–65; Study 2: N=175, 7 days, 5 beeps/day, Ages=20–80) and EOD (Study 1: N=2,022, 8 days, Ages=35–84; Study 2: N=311, 8 days, Ages=21–63) studies revealed significant stressor-related increases in negative affect across all studies. Age-related decreases in reactivity were observed across all studies, but only statistically significant for EOD studies. Discussion will focus on design and measurement considerations for EMA and EOD studies for understanding stress processes and aging.

Abstract Retirement is an important transition in later life, associated with changes in social roles. It is unclear, however, whether the retirement transition modifies aging-related changes in mental, physical, and cognitive health. Using data from the Health and Retirement Study, we examined changes in depressive symptoms, self-rated health, and memory prior to, at, and after the retirement transition among 6,830 participants (Ages=50-97, 58% female) assessed biennially up to 10 times from 1992-2010. Preliminary results indicate a sudden and significant increase in depressive symptoms and decreases in self-rated health and memory at the transition to retirement (ps<.05). These effects increased among individuals retiring at older ages (ps<.01). Further, aging-related increases in depressive symptomatology became faster after retirement (p<.01). Aging-related decreases in self-rated health and memory were unchanged by the transition. Discussion will focus on the contribution of transitions to understanding trajectories of mental, physical, and cognitive health in later life.