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Physical Review Letters Jun 2024We determine the adsorption rate of polymer melts by means of measurements of molecular mobility. We show that the complex set of molecular rearrangements involved in...
We determine the adsorption rate of polymer melts by means of measurements of molecular mobility. We show that the complex set of molecular rearrangements involved in the adsorption of polymers on flat surfaces can be modeled as an equilibration kinetics driven by the slow Arrhenius process (SAP), a recently discovered molecular mechanism. Our predictive model is based on the single hypothesis that the number of chains adsorbed per unit surface within the timescale of spontaneous fluctuations associated to the SAP is a temperature-invariant constant, not depending on the chemical structure of the polymer. Going beyond the qualitative arguments setting a correlation between equilibrium and nonequilibrium properties, we demonstrate that the rate at which an adsorbed layer grows does not depend on interfacial interactions. By considering simple physical arguments, we demonstrate that this quantity can be straightforwardly determined using the energy barrier of molecular motion as only input.
PubMed: 38949357
DOI: 10.1103/PhysRevLett.132.248101 -
Disability and Rehabilitation.... Jul 2024Disability influences activities of daily living, leading to unsafe conditions, poor quality of life, and dependence on others and assistive technologies. Despite...
BACKGROUND
Disability influences activities of daily living, leading to unsafe conditions, poor quality of life, and dependence on others and assistive technologies. Despite limited access and unmet needs, assistive technology enables users to participate in education and be independent members of their community. Students with disabilities in higher education face many challenges in their day-to-day activities and evidence is limited in the study area. Therefore, this study aimed to explore assistive technology experience and daily living challenges among students with disabilities in higher education.
METHOD
A descriptive qualitative study design was employed at the University of Gondar, Gondar, Ethiopia, between December 20, 2022, and January 20, 2023. A purposive sampling method was employed to recruit 14 students with disabilities. An in-depth interview was employed using semi-structured questionnaires. Open Code version 4 software for coding and reflexive thematic analysis approach was employed for the analysis.
RESULT
A total of 14 students with disabilities were included in an in-depth interview. Four main themes emerged, which included activities of daily living, attitudes toward people with disabilities, barriers to accessibility, and access to assistive technology.
CONCLUSION
Barriers to activities of daily living among students with disabilities were poor accessibility of infrastructural facilities, lack of teaching/learning materials in an accessible format, and negative attitudes. The present study's finding is needed to support students in higher education for their academic achievement and to design appropriate rehabilitation strategies and policies on the accessibility of physical infrastructures, inclusive education, and the provision of assistive technology.
PubMed: 38949131
DOI: 10.1080/17483107.2024.2362248 -
Innovation in Aging 2024In most western countries, older adults depend on private cars for transportation and do not proactively plan for driving cessation. The objective of this review was to... (Review)
Review
BACKGROUND AND OBJECTIVES
In most western countries, older adults depend on private cars for transportation and do not proactively plan for driving cessation. The objective of this review was to examine current research studies outlining effective interventions and strategies to assist older adults during their transition from driver to driving retirement or cessation.
RESEARCH DESIGN AND METHODS
A search was completed across 9 databases using key words and MeSH terms for drivers, cessation of driving, and older adult drivers. Eligibility screening of 9,807 titles and abstracts, followed by a detailed screening of 206 papers, was completed using the Covidence platform. Twelve papers were selected for full-text screen and data extraction, comprising 3 papers with evidence-based intervention programs and 9 papers with evidence-informed strategies.
RESULTS
Three papers met the research criteria of a controlled study for programs that support and facilitate driving cessation for older adults. Nine additional studies were exploratory or descriptive, which outlined strategies that could support older drivers, their families, and/or healthcare professionals during this transition. Driving retirement programs/toolkits are also presented.
DISCUSSION AND IMPLICATIONS
The driver retirement programs had promising results, but there were methodological weaknesses within the studies. Strategies extracted contributed to 6 themes: of the topic, is important, is critical, away from assessment to proactive planning, is needed, and should be the end result. Meeting the transportation needs of older adults will be essential to support aging in place, out-of-home mobility, and participation, particularly in developed countries where there is such a high dependency on private motor vehicles.
PubMed: 38948542
DOI: 10.1093/geroni/igae054 -
Frontiers in Endocrinology 2024Obesity impairs bone marrow (BM) glucose metabolism. Adult BM constitutes mostly of adipocytes that respond to changes in energy metabolism by modulating their...
OBJECTIVES
Obesity impairs bone marrow (BM) glucose metabolism. Adult BM constitutes mostly of adipocytes that respond to changes in energy metabolism by modulating their morphology and number. Here we evaluated whether diet or exercise intervention could improve the high-fat diet (HFD) associated impairment in BM glucose uptake (BMGU) and whether this associates with the morphology of BM adipocytes (BMAds) in rats.
METHODS
Eight-week-old male Sprague-Dawley rats were fed either HFD or chow diet for 24 weeks. Additionally after 12 weeks, HFD-fed rats switched either to chow diet, voluntary intermittent running exercise, or both for another 12 weeks. BMAd morphology was assessed by perilipin-1 immunofluorescence staining in formalin-fixed paraffin-embedded tibial sections. Insulin-stimulated sternal and humeral BMGU were measured using [F]FDG-PET/CT. Tibial microarchitecture and mineral density were measured with microCT.
RESULTS
HFD rats had significantly higher whole-body fat percentage compared to the chow group (17% vs 13%, respectively; = 0.004) and larger median size of BMAds in the proximal tibia (815 µm vs 592 µm, respectively; = 0.03) but not in the distal tibia. Switch to chow diet combined with running exercise normalized whole-body fat percentage ( < 0.001) but not the BMAd size. At 32 weeks of age, there was no significant difference in insulin-stimulated BMGU between the study groups. However, BMGU was significantly higher in sternum compared to humerus ( < 0.001) and higher in 8-week-old compared to 32-week-old rats ( < 0.001). BMAd size in proximal tibia correlated positively with whole-body fat percentage (r = 0.48, = 0.005) and negatively with humeral BMGU (r = -0.63, = 0.02). HFD significantly reduced trabecular number ( < 0.001) compared to the chow group. Switch to chow diet reversed this as the trabecular number was significantly higher ( = 0.008) than in the HFD group.
CONCLUSION
In this study we showed that insulin-stimulated BMGU is age- and site-dependent. BMGU was not affected by the study interventions. HFD increased whole-body fat percentage and the size of BMAds in proximal tibia. Switching from HFD to a chow diet and running exercise improved glucose homeostasis and normalized the HFD-induced increase in body fat but not the hypertrophy of BMAds.
Topics: Animals; Male; Rats, Sprague-Dawley; Rats; Adiposity; Diet, High-Fat; Physical Conditioning, Animal; Bone Marrow; Glucose; Obesity; Adipocytes
PubMed: 38948514
DOI: 10.3389/fendo.2024.1422869 -
Frontiers in Pharmacology 2024"Kratom" refers to an array of bioactive products derived from , a tree indigenous to Southeast Asia. Most kratom consumers report analgesic and stimulatory effects, and...
BACKGROUND
"Kratom" refers to an array of bioactive products derived from , a tree indigenous to Southeast Asia. Most kratom consumers report analgesic and stimulatory effects, and common reasons for use are to address mental and physical health needs, manage pain, and to reduce use of other substances. Natural-history studies and survey studies suggest that many kratom consumers perceive benefits from those uses, but such studies are unlikely to capture the full range of kratom-use experiences.
METHODS
We collected text data from Reddit posts from 2020-2022 to qualitatively examine conceptualizations, motivations, effects, and consequences associated with kratom use among people posting to social media. Reddit posts mentioning kratom were studied using template thematic analysis, which included collecting descriptions of kratom product types and use practices. Network analyses of coded themes was performed to examine independent relationships among themes, and between themes and product types.
RESULTS
Codes were applied to 329 of the 370 posts that comprised the final sample; 134 posts contained kratom product descriptions. As Reddit accounts were functionally anonymous, demographic estimates were untenable. Themes included kratom physical dependence (tolerance, withdrawal, or use to avoid withdrawal), perceived addiction (net detrimental effects on functioning), and quitting. Extract products were positively associated with reports of perceived addiction, dependence, and experiences of quitting kratom. Many used kratom for energy and self-treatment of pain, fatigue, and problems associated with opioid and alcohol; they perceived these uses as effective. Consumers expressed frustrations about product inconsistencies and lack of product information.
CONCLUSION
As in previous studies, kratom was deemed helpful for some and a hindrance to others, but we also found evidence of notable negative experiences with kratom products that have not been well documented in surveys. Daily kratom use may produce mild-moderate physical dependence, with greater severity being possibly more common with concentrated extracts; however, there are currently no human laboratory studies of concentrated kratom extracts. Such studies, and detailed kratom product information, are needed to help inform consumer decision-making.
PubMed: 38948457
DOI: 10.3389/fphar.2024.1412397 -
PeerJ 2024Iron deficiency is known to impair muscle function and reduce athletic performance, while vitamin D has been reported to induce iron deficiency. However, the mechanism...
BACKGROUND
Iron deficiency is known to impair muscle function and reduce athletic performance, while vitamin D has been reported to induce iron deficiency. However, the mechanism underlying exercise-induced changes in iron metabolism and the involvement of vitamins in this mechanism are unclear. The present study examined changes in biological iron metabolism induced by continuous training and the effects of vitamin D on these changes.
METHODS
Diet, physical characteristics, and blood test data were collected from 23 female high school students in a dance club on the last day of each of a 2-month continuous training period and a 2-week complete rest periods.
RESULTS
Serum hepcidin-25 levels were significantly lower during the training period than the rest period ( = 0.013), as were the red blood cell count, hemoglobin, and hematocrit (all < 0.001). Serum erythropoietin was significantly higher ( = 0.001) during the training period. Significant positive correlations were observed between 25(OH)D levels and serum iron, serum ferritin, and transferrin saturation during the training period. Multiple regression analysis with serum 25(OH)D level as the dependent variable and serum ferritin and iron levels as independent variables during the training period revealed a significant association with serum ferritin.
CONCLUSION
Continuous training may promote hemolysis and erythropoiesis, contributing to the suppression of hepcidin expression. The relationship between serum 25(OH)D and iron may be closely related to metabolic changes induced by the exercise load.
Topics: Humans; Hepcidins; Female; Adolescent; Vitamin D; Ferritins; Athletes; Iron; Exercise
PubMed: 38948227
DOI: 10.7717/peerj.17566 -
MLife Jun 2024The silencing information regulator (SIR) complex contains up to four proteins, namely Sir1, Sir2, Sir3, and Sir4. While Sir2 encodes a NAD-dependent histone... (Review)
Review
The silencing information regulator (SIR) complex contains up to four proteins, namely Sir1, Sir2, Sir3, and Sir4. While Sir2 encodes a NAD-dependent histone deacetylase, other SIR proteins mainly function as structural and scaffold components through physical interaction with various proteins. The SIR complex displays different conformation and composition, including Sir2 homotrimer, Sir1-4 heterotetramer, Sir2-4 heterotrimer, and their derivatives, which recycle and relocate to different chromosomal regions. Major activities of the SIR complex are transcriptional silencing through chromosomal remodeling and modulation of DNA double-strand-break repair pathways. These activities allow the SIR complex to be involved in mating-type maintenance and switching, telomere and subtelomere gene silencing, promotion of nonhomologous end joining, and inhibition of homologous recombination, as well as control of cell aging. This review explores the potential link between epigenetic regulation and DNA damage response conferred by the SIR complex under various conditions aiming at understanding its roles in balancing cell survival and genomic stability in response to internal and environmental stresses. As core activities of the SIR complex are highly conserved in eukaryotes from yeast to humans, knowledge obtained in the yeast may apply to mammalian Sirtuin homologs and related diseases.
PubMed: 38948145
DOI: 10.1002/mlf2.12108 -
World Journal of Stem Cells Jun 2024Proliferation and differentiation of intestinal stem cell (ISC) to replace damaged gut mucosal epithelial cells in inflammatory states is a critical step in ameliorating...
Proliferation and differentiation of intestinal stem cell (ISC) to replace damaged gut mucosal epithelial cells in inflammatory states is a critical step in ameliorating gut inflammation. However, when this disordered proliferation continues, it induces the ISC to enter a cancerous state. The gut microbiota on the free surface of the gut mucosal barrier is able to interact with ISC on a sustained basis. Microbiota metabolites are able to regulate the proliferation of gut stem and progenitor cells through transcription factors, while in steady state, differentiated colonocytes are able to break down such metabolites, thereby protecting stem cells at the gut crypt. In the future, the gut flora and its metabolites mediating the regulation of ISC differentiation will be a potential treatment for enteropathies.
PubMed: 38948097
DOI: 10.4252/wjsc.v16.i6.619 -
World Journal of Stem Cells Jun 2024Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease that affects premature infants. Although mounting evidence supports the therapeutic effect of...
BACKGROUND
Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease that affects premature infants. Although mounting evidence supports the therapeutic effect of exosomes on NEC, the underlying mechanisms remain unclear.
AIM
To investigate the mechanisms underlying the regulation of inflammatory response and intestinal barrier function by umbilical cord mesenchymal stem cell (UCMSCs) exosomes, as well as their potential in alleviating NEC in neonatal mice.
METHODS
NEC was induced in 5-d-old C57BL/6 pups through hypoxia and gavage feeding of formula containing lipopolysaccharide (LPS), after which the mice received human UCMSC exosomes (hUCMSC-exos). The control mice were allowed to breastfeed with their dams. Ileal tissues were collected from the mice and analyzed by histopathology and immunoblotting. Colon tissues were collected from NEC neonates and analyzed by immunofluorescence. Molecular biology and cell culture approaches were employed to study the related mechanisms in intestinal epithelial cells.
RESULTS
We found that autophagy is overactivated in intestinal epithelial cells during NEC, resulting in reduced expression of tight junction proteins and an increased inflammatory response. The ability of hUCMSC-exos to ameliorate NEC in a mouse model was dependent on decreased intestinal autophagy. We also showed that hUCMSC-exos alleviate the inflammatory response and increase migration ability in intestinal epithelial cells induced by LPS.
CONCLUSION
These results contribute to a better understanding of the protective mechanisms of hUCMSC-exos against NEC and provide a new theoretical and experimental foundation for NEC treatment. These findings also enhance our understanding of the role of the autophagy mechanism in NEC, offering potential avenues for identifying new therapeutic targets.
PubMed: 38948093
DOI: 10.4252/wjsc.v16.i6.728 -
The Yale Journal of Biology and Medicine Jun 2024In the Netherlands, one out of two people will be confronted with the diagnosis of cancer sometime in their life. Against this increased number of patients, a large... (Review)
Review
In the Netherlands, one out of two people will be confronted with the diagnosis of cancer sometime in their life. Against this increased number of patients, a large proportion luckily can be cured. Today, a rather high proportion of people receive treatment to control cancer growth or stabilize the disease, sometimes, for the rest of their lives. If such long-standing treatment is administered for more than 10-20 years, the stage of cancer is presently often not referred to as "palliative" anymore, but much more often as "chronic." It could be argued that regardless of the cancer disease stage you are in and whether you are or can be cured, your cancer diagnosis nevertheless has become part of your life, including the experience of chronicity. Discussions surrounding the chronicity of cancer in the context of cancer are still ongoing. This is especially the case because "experiencing chronicity" is dependent on the type of cancer and is less applicable in cancers where the prognosis is often less than one year, such as is more frequently the case with lung or pancreatic cancer. In all situations, experiencing chronicity nevertheless brings along uncertainty, either with or without chronic stress. Combatting stress by choosing the right wording, maintaining an optimistic stance along with physical activity and/or psychosocial education seems important to optimize well-being and to stabilize tumor growth or remove the tumor. In conclusion, chronicity in the context of treating and caring for cancer seems a somewhat gray area. However, regardless in how we, as medical professionals, speak about cancer with long-standing disease trajectories (that sometimes even can be cured), it first of all seems important to approach, take care, and treat patients well. This can facilitate discussions with patients about their disease and disease experiences. Moreover, it can stimulate patients themselves to take responsibility for their own health, which can be of added value to the entire disease trajectory.
Topics: Humans; Neoplasms; Netherlands
PubMed: 38947106
DOI: 10.59249/FQVX3500