Ejecta from the DART-produced active asteroid Dimorphos.

Some active asteroids have been proposed to be formed as a result of impact events1. Because active asteroids are generally discovered by chance only after their tails have fully formed, the process of how impact ejecta evolve into a tail has, to our knowledge, not been directly observed. The Double Asteroid Redirection Test (DART) mission of NASA2, in addition to having successfully changed the orbital period of Dimorphos3, demonstrated the activation process of an asteroid resulting from an impact under precisely known conditions. Here we report the observations of the DART impact ejecta with the Hubble Space Telescope from impact time T + 15 min to T + 18.5 days at spatial resolutions of around 2.1 km per pixel. Our observations reveal the complex evolution of the ejecta, which are first dominated by the gravitational interaction between the Didymos binary system and the ejected dust and subsequently by solar radiation pressure. The lowest-speed ejecta dispersed through a sustained tail that had a consistent morphology with previously observed asteroid tails thought to be produced by an impact4,5. The evolution of the ejecta after the controlled impact experiment of DART thus provides a framework for understanding the fundamental mechanisms that act on asteroids disrupted by a natural impact1,6.

Momentum transfer from the DART mission kinetic impact on asteroid Dimorphos.

The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of the binary asteroid (65803) Didymos, at 23:14 UTC on 26 September 2022 as a planetary defence test1. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planetary defence, intended to validate kinetic impact as a means of asteroid deflection. Here we report a determination of the momentum transferred to an asteroid by kinetic impact. On the basis of the change in the binary orbit period2, we find an instantaneous reduction in Dimorphos's along-track orbital velocity component of 2.70 ± 0.10 mm s-1, indicating enhanced momentum transfer due to recoil from ejecta streams produced by the impact3,4. For a Dimorphos bulk density range of 1,500 to 3,300 kg m-3, we find that the expected value of the momentum enhancement factor, ß, ranges between 2.2 and 4.9, depending on the mass of Dimorphos. If Dimorphos and Didymos are assumed to have equal densities of 2,400 kg m-3, [Formula: see text]. These ß values indicate that substantially more momentum was transferred to Dimorphos from the escaping impact ejecta than was incident with DART. Therefore, the DART kinetic impact was highly effective in deflecting the asteroid Dimorphos.

THUMPD2 catalyzes the N2-methylation of U6 snRNA of the spliceosome catalytic center and regulates pre-mRNA splicing and retinal degeneration.

The mechanisms by which the relatively conserved spliceosome manages the enormously large number of splicing events that occur in humans (∼200 000 versus ∼300 in yeast) are poorly understood. Here, we show deposition of one RNA modification-N2-methylguanosine (m2G) on the G72 of U6 snRNA (the catalytic center of the spliceosome) promotes efficient pre-mRNA splicing activity in human cells. This modification was identified to be conserved among vertebrates. Further, THUMPD2 was demonstrated as the methyltransferase responsible for U6 m2G72 by explicitly recognizing the U6-specific sequences and structural elements. The knock-out of THUMPD2 eliminated U6 m2G72 and impaired the pre-mRNA splicing activity, resulting in thousands of changed alternative splicing events of endogenous pre-mRNAs in human cells. Notably, the aberrantly spliced pre-mRNA population elicited the nonsense-mediated mRNA decay pathway. We further show that THUMPD2 was associated with age-related macular degeneration and retinal function. Our study thus demonstrates how an RNA epigenetic modification of the major spliceosome regulates global pre-mRNA splicing and impacts physiology and disease.

PolyQ-expanded ataxin-2 aggregation impairs cellular processing-body homeostasis via sequestering the RNA helicase DDX6.

Ataxin-2 (Atx2) is a polyglutamine (polyQ) tract-containing RNA-binding protein, while its polyQ expansion may cause protein aggregation that is implicated in the pathogenesis of neurodegenerative diseases such as spinocerebellar ataxia type 2 (SCA2). However, the molecular mechanism underlying how Atx2 aggregation contributes to the proteinopathies remains elusive. Here, we investigated the influence of Atx2 aggregation on the assembly and functionality of cellular processing bodies (P-bodies) by using biochemical and fluorescence imaging approaches. We have revealed that polyQ-expanded (PQE) Atx2 sequesters the DEAD-box RNA helicase (DDX6), an essential component of P-bodies, into aggregates or puncta via some RNA sequences. The N-terminal like-Sm (LSm) domain of Atx2 (residues 82-184) and the C-terminal helicase domain of DDX6 are responsible for the interaction and specific sequestration. Moreover, sequestration of DDX6 may aggravate pre-mRNA mis-splicing, and interfere with the assembly of cellular P-bodies, releasing the endoribonuclease MARF1 that promotes mRNA decay and translational repression. Rescuing the DDX6 protein level can recover the assembly and functionality of P-bodies, preventing targeted mRNA from degradation. This study provides a line of evidence for sequestration of the P-body components and impairment of the P-body homeostasis in dysregulating RNA metabolism, which is implicated in the disease pathologies and a potential therapeutic target.

Local Management for Diabetic Foot Ulcers: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: This study evaluated the efficacy of various local management strategies for diabetic foot ulcers (DFUs). BACKGROUND: Several surgical and non-surgical local interventional approaches are available for the treatment of DFUs. The comparative effectiveness of different treatments is unknown, and it remains unclear which approach is the optimal choice for DFUs treatment due to limited direct comparisons. METHODS: We did a systematic review and meta-analysis to select the optimal approach to DFUs local management. We searched Medline, Embase, Web of Science, and ClinicalTrials.gov from inception to September 1, 2023, to identify relevant randomized controlled trials (RCTs). We analysed data by pairwise meta-analyses with a random-effects model. A network meta-analysis using the surface under the cumulative ranking curve (SUCRA) was performed to evaluate the comparative efficacy of different interventional approaches in the early (within 12 wk) and late stages (over 12 wk). RESULTS: 141 RCTs involving 14076 patients and exploring 14 interventional strategies were eligible for inclusion. Most studies (102/141) had at least one risk-of-bias dimension. Good consistency was observed during the analysis. Local pairwise comparisons demonstrated obvious differences in the early-stage healing rate and early- and late-stage healing times, while no significant difference in the late-stage healing rate or adverse events were noted. SUCRAs identified the standard of care (SOC) + decellularized dressing (DD), off-loading (OL), and autogenous graft (AG) as the three most effective interventions within 12 weeks for both healing rate (97%, mean rank: 1.4; 90%, mean rank: 2.3; 80.8%, mean rank: 3.5, respectively) and healing time (96.7%, mean rank: 1.4; 83.0%, mean rank: 3.0; 76.8%, mean rank: 3.8, respectively). After 12 weeks, local drug therapy (LDT) (89.5%, mean rank: 2.4) and OL (82.4%, mean rank: 3.3) ranked the highest for healing rate, and OL (100.0%, mean rank: 1.0) for healing time. With respect to adverse events, moderate and high risks were detected in the SOC + DD (53.7%, mean rank: 7.0) and OL (24.4%, mean rank: 10.8) groups, respectively. CONCLUSION: The findings suggest that OL provided considerable benefits for DFU healing in both the early and late stages, but the high risk of adverse events warrants caution. SOC+DD may be the preferred option in the early stages, with an acceptable risk of adverse events.

RNA-assisted sequestration of RNA-binding proteins by cytoplasmic inclusions of the C-terminal 35-kDa fragment of TDP-43.

TDP-43 (also known as TARDBP) is a nuclear splicing factor functioning in pre-mRNA processing. Its C-terminal 35-kDa fragment (TDP-35) forms inclusions or aggregates in cytoplasm, and sequesters full-length TDP-43 into the inclusions through binding with RNA. We extended the research to investigate whether TDP-35 inclusions sequester other RNA-binding proteins (RBPs) and how RNA-binding specificity has a role in this sequestration process. We have characterized T-cell restricted intracellular antigen-1 (TIA1) and other RBPs that can be sequestered into the TDP-35 inclusions through specific RNA binding, and found that this sequestration leads to the dysfunction of TIA1 in maturation of target pre-mRNA. Moreover, we directly visualized the dynamic sequestration of TDP-43 by the cytoplasmic TDP-35 inclusions by live-cell imaging. Our results demonstrate that TDP-35 sequesters some specific RBPs and this sequestration is assisted by binding with RNA in a sequence-specific manner. This study provides further evidence in supporting the hijacking hypothesis for RNA-assisted sequestration and will be beneficial to further understanding of the TDP-43 proteinopathies.

Single-cell transcriptome landscape of zebrafish liver reveals hepatocytes and immune cell interactions in understanding nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease in the world. Immunity is the major contributing factor in NAFLD; however, the interaction of immune cells and hepatocytes in disease progression has not been fully elucidated. As a popular species for studying NAFLD, zebrafish, whose liver is a complex immune system mediated by immune cells and non-immune cells in maintaining immune tolerance and homeostasis. Understanding the cellular composition and immune environment of zebrafish liver is of great significance for its application in NAFLD. Here, we established a liver atlas that consists of 10 cell types using single-cell RNA sequencing (scRNA-seq). By examining the heterogeneity of hepatocytes and analyzing the expression of NAFLD-associated genes in the specific cluster, we provide a potential target cell model to study NAFLD. Additionally, our analysis identified two subtypes of distinct resident macrophages with inflammatory and non-inflammatory functions and characterized the successive stepwise development of T cell subclusters in the liver. Importantly, we uncovered the possible regulation of macrophages and T cells on target cells of fatty liver by analyzing the cellular interaction between hepatocytes and immune cells. Our data provide valuable information for an in-depth study of immune cells targeting hepatocytes to regulate the immune balance in NAFLD.

Combining antibiotic-loaded bone cement-based free vastus lateralis muscle-sparing flap with split-thickness skin grafts: A reliable strategy for reconstructing diabetic foot ulcers at non-weight-bearing areas.

Diabetic foot ulcers (DFUs) present significant challenges due to their associated amputation rates, mortality, treatment complexity and excessive costs. Our earlier work introduced a wound surgical integrated treatment (WSIT) for DFUs, yielding promising outcomes. This study focuses on a specific WSIT protocol employing antibiotic-loaded bone cement (ALBC) in the first Stage, and free vastus lateralis muscle-sparing (VLMS) flaps and split-thickness skin grafts (STSGs) in the second stage to repair non-weight-bearing DFUs. From July 2021 to July 2023, seven DFU patients (aged 47-71 years) underwent this treatment. Demographic data, hospital stay and repair surgery times were collected. Histological and immunohistochemical analyses assessed angiogenesis, collagen deposition and inflammation. SF-36 questionnaire measured pre- and postoperative quality of life. Preoperative ultrasound Doppler showed that the peak blood flow velocity of the recipient area artery was significantly >30 cm/s (38.6 ± 6.8 cm/s) in all patients. Muscle flap sizes varied from 8 × 3.5 × 1 to 18 × 6 × 2 cm. The operation time of the repair surgery was 156.9 ± 15.08 minutes, and the hospital stay was 18.9 ± 3.3 days. Histological analysis proved that covering DFUs with ALBC induced membrane formation and increased collagen, neovascularization and M2 macrophages fraction while reducing M1 macrophages one. All grafts survived without amputation during a 7- to 24-month follow-up, during which SF-36 scores significantly improved. A combination of ALBC with free VLMS flaps and STSGs proved to be safe and effective for reconstructing non-weight-bearing DFUs. It rapidly controlled infection, enhanced life quality and foot function, and reduced hospitalization time. We advocate integrating this strategy into DFU treatment plans.

Human Cytomegalovirus Hijacks WD Repeat Domain 11 for Virion Assembly Compartment Formation and Virion Morphogenesis.

Human cytomegalovirus (HCMV) has a large (∼235 kb) genome with more than 200 predicted open reading frames that exploits numerous cellular factors to facilitate its replication. A key feature of HCMV-infected cells is the emergence of a distinctive membranous cytoplasmic compartment termed the virion assembly compartment (vAC). Here, we report that host protein WD repeat domain 11 (WDR11) plays a key role in vAC formation and virion morphogenesis. We found that WDR11 was upregulated at both mRNA and protein levels during HCMV infection. At the late stage of HCMV replication, WDR11 relocated to the vAC and colocalized with markers of the trans-Golgi network (TGN) and vAC. Depletion of WDR11 hindered HCMV-induced membrane reorganization of the Golgi and TGN, altered vAC formation, and impaired HCMV secondary envelopment and virion morphogenesis. Further, motifs critical for the localization of WDR11 in TGN were identified by alanine-scanning mutagenesis. Mutation of these motifs led to WDR11 mislocation outside the TGN and loss of vAC formation. Taken together, these data indicate that host protein WDR11 is required for efficient viral replication at the stage of virion assembly, possibly by facilitating the remodeling of the endomembrane system for vAC formation and virion morphogenesis. IMPORTANCE During the late phase of human cytomegalovirus (HCMV) infection, the endomembrane system is dramatically reorganized, resulting in the formation of a unique structure termed the virion assembly compartment (vAC), which is critical for the assembly of infectious virions. The mechanism of HCMV-induced vAC formation is still not fully understood. In this report, we identified a host factor, WDR11, that plays an important role in vAC formation. Our findings argue that WDR11 contributes to the relocation of the Golgi and trans-Golgi network to the vAC, a membrane reorganization process that appears to be required for efficient virion maturation. The present work provides new insights into the vAC formation and HCMV virion morphogenesis and a potential novel target for antiviral treatment.

THUMPD3-TRMT112 is a m2G methyltransferase working on a broad range of tRNA substrates.

Post-transcriptional modifications affect tRNA biology and are closely associated with human diseases. However, progress on the functional analysis of tRNA modifications in metazoans has been slow because of the difficulty in identifying modifying enzymes. For example, the biogenesis and function of the prevalent N2-methylguanosine (m2G) at the sixth position of tRNAs in eukaryotes has long remained enigmatic. Herein, using a reverse genetics approach coupled with RNA-mass spectrometry, we identified that THUMP domain-containing protein 3 (THUMPD3) is responsible for tRNA: m2G6 formation in human cells. However, THUMPD3 alone could not modify tRNAs. Instead, multifunctional methyltransferase subunit TRM112-like protein (TRMT112) interacts with THUMPD3 to activate its methyltransferase activity. In the in vitro enzymatic assay system, THUMPD3-TRMT112 could methylate all the 26 tested G6-containing human cytoplasmic tRNAs by recognizing the characteristic 3'-CCA of mature tRNAs. We also showed that m2G7 of tRNATrp was introduced by THUMPD3-TRMT112. Furthermore, THUMPD3 is widely expressed in mouse tissues, with an extremely high level in the testis. THUMPD3-knockout cells exhibited impaired global protein synthesis and reduced growth. Our data highlight the significance of the tRNA: m2G6/7 modification and pave a way for further studies of the role of m2G in sperm tRNA derived fragments.

Coaggregation of polyglutamine (polyQ) proteins is mediated by polyQ-tract interactions and impairs cellular proteostasis.

Nine polyglutamine (polyQ) proteins have already been identified that are considered to be associated with the pathologies of neurodegenerative disorders called polyQ diseases, but whether these polyQ proteins mutually interact and synergize in proteinopathies remains to be elucidated. In this study, 4 polyQ-containing proteins, androgen receptor (AR), ataxin-7 (Atx7), huntingtin (Htt) and ataxin-3 (Atx3), are used as model molecules to investigate their heterologous coaggregation and consequent impact on cellular proteostasis. Our data indicate that the N-terminal fragment of polyQ-expanded (PQE) Atx7 or Htt can coaggregate with and sequester AR and Atx3 into insoluble aggregates or inclusions through their respective polyQ tracts. In vitro coprecipitation and NMR titration experiments suggest that this specific coaggregation depends on polyQ lengths and is probably mediated by polyQ-tract interactions. Luciferase reporter assay shows that these coaggregation and sequestration effects can deplete the cellular availability of AR and consequently impair its transactivation function. This study provides valid evidence supporting the viewpoint that coaggregation of polyQ proteins is mediated by polyQ-tract interactions and benefits our understanding of the molecular mechanism underlying the accumulation of different polyQ proteins in inclusions and their copathological causes of polyQ diseases.

Echinacoside exerts its protective effects in a type 2 diabetes mellitus injury model via the AKT pathway.

Echinacoside (ECH) is the main compound of Cistanche deserticola, which possesses antioxidant, antitumor, antifatigue, and anti-inflammatory properties. The present study investigated the protective effects of echinacoside on type 2 diabetes mellitus (T2DM)-induced injury in T2DM injury db/db mice model and insulin-resistant LO2 cell model. The results demonstrated that ECH probably alleviated T2DM-induced injury by mediating the AKT pathway, which provided a new direction for the treatment of T2DM-induced injury.

GAUSS - genesis of asteroids and evolution of the solar system: A sample return mission to Ceres.

The goal of Project GAUSS (Genesis of Asteroids and evolUtion of the Solar System) is to return samples from the dwarf planet Ceres. Ceres is the most accessible candidate of ocean worlds and the largest reservoir of water in the inner Solar System. It shows active volcanism and hydrothermal activities in recent history. Recent evidence for the existence of a subsurface ocean on Ceres and the complex geochemistry suggest past habitability and even the potential for ongoing habitability. GAUSS will return samples from Ceres with the aim of answering the following top-level scientific questions: What is the origin of Ceres and what does this imply for the origin of water and other volatiles in the inner Solar System?What are the physical properties and internal structure of Ceres? What do they tell us about the evolutionary and aqueous alteration history of dwarf planets?What are the astrobiological implications of Ceres? Is it still habitable today?What are the mineralogical connections between Ceres and our current collections of carbonaceous meteorites?

[Quantitative NMR spectroscopy and its application in quality control of Chinese medicinal injection].

Chinese medicinal injection, made of active components extracted from Chinese medicine or Chinese medicinal compound, is a novel dosage form of Chinese patent medicine in China and is pivotal in the traditional Chinese medicine(TCM) industry. The quality control standard of Chinese medicinal injection determines its safety and efficacy. The quantitative nuclear magnetic resonance(qNMR) spectroscopy is a non-targeted, non-invasive, and non-destructive technique with high reproducibility, short measurement time, convenient sample preparation, a broad range of linearity, and no requirement on the reference substance of tested components, which is advantageous as compared with traditional chromatographic methods, and it can provide information about the molecular composition of the tested samples. Therefore, in light of multiple challenges in the quality control of Chinese medicinal injection, such as complex composition, difficulties in quantitative analysis, and the shortage of reference substances, the application of qNMR spectroscopy combined with chemometrics techniques was proposed for the quality evaluation of Chinese medicine reference substances, Chinese medicinal injection, and intermediates in the production process, as well as for the stability analysis of Chinese medicinal injection. This study is expected to provide references for the application of qNMR spectroscopy in the quality control of Chinese medicinal injection.

[Quality evaluation of ginsenoside reference substances based on qNMR spectroscopy].

The present study established a quality evaluation method for ginsenoside reference substances based on quantitative nuclear magnetic resonance(qNMR) spectroscopy. ~1H-NMR spectra were collected on Bruker Avance Ⅲ 500 MHz NMR spectrometer equipped with a 5 mm BBO probe. The acquire parameters were set up as follows: pulse sequence of 30°, D_1=20 s, probe temperature= 303 K, and the scan number = 32. Dimethyl terephthalate, a high-quality ~1H-qNMR standard, was used as the internal standard and measured by the absolute quantitative method. Methyl peaks of comparatively good sensitivity were selected for quantification, and linear fitting deconvolution was adopted to improve the accuracy of integration results. The qNMR spectroscopy-based method was established and validated, which was then used for the quality evaluation of ginsenoside Rg_1, ginsenoside Re, ginsenoside Rb_1, ginsenoside Rd, and notoginsenoside R_1. The results suggested that the content of these ginsenoside reference standards obtained from the qNMR spectroscopy-based method was lower than that detected by the normalization method in HPLC provided by the manufacturers. In conclusion, the qNMR spectroscopy-based method can ensure the quality of ginsenoside reference substances and provide powerful support for the accurate quality evaluation of Chinese medicine and its preparations. The qNMR spectroscopy-based method is simple, rapid, and accurate, which can be developed for the quantitative assay of Chinese medicine standard references.

[Fingerprint of Shenmai Injection based on ~1H-NMR technique].

Shenmai Injection is a Chinese medicinal injection prepared from Ginseng Radix et Rhizoma Rubra and Ophiopogonis Radix, which is widely used in clinical practice for the treatment and adjuvant therapy of cardiovascular diseases with significant pharmacological effects. Proton nuclear magnetic resonance spectroscopy(~1H-NMR) has the advantages of simple and nondestructive sample pretreatment, fast analysis, abundant chemical information, quantification and no need to follow the standard curve. It is widely used in the analysis and research of complex mixtures of traditional Chinese medicine, clinical blood and urine samples. In this study, the ~1H-NMR fingerprint of Shenmai Injection was established. Thirty-two chemical components were identified, including seven amino acids, eight small molecular organic acids, one alkaloid, four sugars, two nucleosides, seven saponins, and three other components. Pearson's correlation coefficient and multivariate analysis of variance(principal component analysis combined with hierarchical cluster analysis) were applied based on the ~1H-NMR fingerprint to evaluate the quality consistency. The results showed high-quality consistency of 82 batches of Shenmai Injection. This study confirms that the ~1H-NMR fingerprint has great potential in the application of quality control of Chinese medicinal injection.

[~1H-qNMR quantification of total ginsenosides in Shenmai Injection].

A content determination method based on ~1H-qNMR was developed for the determination of total ginsenosides in Shenmai Injection. The parameters were optimized with CD_3OD as the solvent, dimethyl terephthalate as the internal standard, the peak at δ 8.11 as the internal standard peak, and the peaks at δ 1.68 and δ 0.79 as quantitative peaks of total ginsenosides. The developed ~1H-qNMR-based method was validated methodologically. The results showed that the method could achieve accurate measurement of total ginsenosides in Shenmai Injection in the range of 0.167 6-3.091 1 mmol·L~(-1). The developed ~1H-qNMR-based method for total ginsenosides is simple in operation, short in analysis time, strong in specificity, independent of accompanying standard curve, and small in sample volume, which can serve as a reliable mean for the quality control of Shenmai Injection. This study is expected to provide new ideas for the development of quantification methods of total ginsenosides.

[NMR method for simultaneous determination of 21 chemical components in Danhong Injection].

Danhong Injection, a compound Chinese medicine injection prepared from Salviae Miltiorrhizae Radix et Rhizoma and Carthami Flos, is used in the clinical treatment of coronary heart disease, cerebral thrombosis, myocardial infarction, angina pectoris and other cardiovascular and cerebrovascular diseases. In this study, a quantitative method for simultaneous determination of multiple components in Danhong Injection was developed based on ~1H-qNMR technology and then methodological verification was carried out. The results showed that the established method had good methodological indexes. This method can simultaneously determine the content of 21 chemical components including 6 amino acids, 4 small molecular organic acids, 5 sugars and their derivatives, 1 nucleoside, and 5 aromatic compounds in Danhong Injection. The total content accounted for about 85% of the total solid mass, which reflected the great advantage of ~1H-qNMR method in the analysis of Chinese medicine injections. The ~1H-qNMR method for simultaneous determination of multiple components in Danhong Injection developed in this study has simple operation, short analysis time, and wide application range, which has practical significance for the quality evaluation of Danhong Injection and provides reference for the development of quality control methods for Chinese medicine injections.

Identification of 2-substituted pyrrolo[1,2-b]pyridazine derivatives as new PARP-1 inhibitors.

A library of new 2-substituted pyrrolo[1,2-b]pyridazine derivatives were rapidly assembled and identified as PARP inhibitors. Structure-activity relationship for this class of inhibitor resulted in the discovery of most potent compounds 15a and 15b that exhibited about 29- and 5- fold selective activity against PARP-1 over PARP-2 respectively. The antiproliferative activity of the as-prepared compounds were demonstrated by further celluar assay in BRCA2-deficient V-C8 and BRCA1-deficient MDA-MB-436 cell lines, displaying that compound 15b could robustly reduce the corresponding cell proliferation and growth with CC50s of 340 and 106 nM respectively. The PK property of 15b was also investigated here.

Achieving healthy ageing through the perspective of sense of coherence among senior-only households: a qualitative study.

Objectives: Explore perceptions towards healthy ageing through the perspective of sense of coherence among older adults residing in senior-only households.Methods: A qualitative study using focus group interviews was conducted and appreciative inquiry was adopted as a strengths-based interviewing approach. 27 older adults who either live alone or with their spouses only were involved in six focus group discussions at a community centre in Singapore. Data saturation was achieved and thematic analysis was performed to analyse the data.Results: The four emerging themes were (1) contending evolving vulnerabilities, (2) intrinsic value of health, (3) taking care of oneself is a personal responsibility, and (4) taking one day at a time: outlook towards later part of life. Older adults' underlying pathogenic orientation towards health contributed to their perceived unpredictable confrontations with vicissitudes including illness and death. This played a part to their short outlook towards old age. Consequently, this could limit their will and abilities to seek meaningful pursuits or valued aspirations and movement towards the salutogenic health pole.Conclusion: By reframing the definition of health to pursuing and fulfilling valued accomplishments, optimal health can be achieved regardless of physical health state. This study suggested that sense of coherence towards the pursuit of healthy ageing can be addressed by reducing the unpredictability of ageing-related processes and vulnerabilities (comprehensibility), supporting active adoption of actions which promotes physical, mental and social health (manageability) and individual reflection in making sense of old age to seek motivation in living each day purposefully (meaningfulness).