Value of T2-weighted-based radiomics model in distinguishing Warthin tumor from pleomorphic adenoma of the parotid.

OBJECTIVES: The differentiation of Warthin tumor and pleomorphic adenoma before treatment is crucial for clinical strategies. The aim of this study was to develop and test a T2-weighted-based radiomics model for differentiating pleomorphic adenoma from Warthin tumor of the parotid gland. METHODS: A total of 117 patients, including 61 cases of Warthin tumor and 56 cases of pleomorphic adenoma, were retrospectively enrolled from two centers between January 2010 and June 2022. The training set included 82 cases, and the validation set included 35 cases. From T2-weighted images, 971 radiomics features were extracted. Seven radiomics features remained after a two-step selection process. We used the seven radiomics features and clinical factors through multivariable logistic regression to build radiomics and clinical models, respectively. A radiomics-clinical model was also built that combined the independent clinical predictors with the radiomics features. Through ROC curves, the three models were evaluated and compared. RESULTS: In the radiomics model, AUCs were 0.826 and 0.796 in training and validation sets, respectively. In the clinical model, the AUCs were 0.923 and 0.926 in the training and validation sets, respectively. Decision curve analysis revealed that the radiomics-clinical model had the best diagnostic performance for distinguishing Warthin tumor from pleomorphic adenoma of the parotid gland (AUC = 0.962 and 0.934 for the training and validation sets, respectively). CONCLUSION: The radiomics-clinical model performed well in differentiating pleomorphic adenoma from Warthin tumor of the parotid gland. KEY POINTS: • The clinical model outperformed the radiomics model in distinguishing pleomorphic adenoma from Warthin tumor of the parotid gland. • The radiomics features extracted from T2-weighted images could help differentiate pleomorphic adenoma from Warthin tumor of the parotid gland. • The radiomics-clinical model was superior to the radiomics and the clinical models for differentiating pleomorphic adenoma from Warthin tumor of the parotid gland.

Research on the Effects of Drying Temperature for the Detection of Soil Nitrogen by Near-Infrared Spectroscopy.

Nitrogen nitrates play a significant role in the soil's nutrient cycle, and near-infrared spectroscopy can efficiently and accurately detect the content of nitrate-nitrogen in the soil. Accordingly, it can provide a scientific basis for soil improvement and agricultural productivity by deeply examining the cycle and transformation pattern of nutrients in the soil. To investigate the impact of drying temperature on NIR soil nitrogen detection, soil samples with different N concentrations were dried at temperatures of 50 °C, 65 °C, 80 °C, and 95 °C, respectively. Additionally, soil samples naturally air-dried at room temperature (25 °C) were used as a control group. Different drying times were modified based on the drying temperature to completely eliminate the impact of moisture. Following data collection with an NIR spectrometer, the best preprocessing method was chosen to handle the raw data. Based on the feature bands chosen by the RFFS, CARS, and SPA methods, two linear models, PLSR and SVM, and a nonlinear ANN model were then established for analysis and comparison. It was found that the drying temperature had a great effect on the detection of soil nitrogen by near-infrared spectroscopy. In the meantime, the SPA-ANN model simultaneously yielded the best and most stable accuracy, with Rc2 = 0.998, Rp2 = 0.989, RMSEC = 0.178 g/kg, and RMSEP = 0.257 g/kg. The results showed that NIR spectroscopy had the least effect and the highest accuracy in detecting nitrogen at 80 °C soil drying temperature. This work provides a theoretical foundation for agricultural production in the future.

A computed tomography-based radiomic nomogram for predicting lymph node metastasis in patients with early-stage papillary thyroid carcinoma.

BACKGROUND: Accurate assessment of lymph node metastasis (LNM) is important for the selection of the optimal therapeutic strategy in patients with papillary thyroid carcinoma (PTC). PURPOSE: To develop and validate a radiomics nomogram based on computed tomography (CT) for predicting LNM in patients with early-stage PTC. MATERIAL AND METHODS: A total of 92 patients with pathologically confirmed PTC were divided into a training cohort (n = 64) and validation cohort (n = 28). Radiomic features of the tumor and peritumoral interstitium were extracted from contrast-enhanced CT images. The radiomic signature was constructed and the radiomic score (Rad-score) was calculated. Combined with the Rad-score and independent clinical factors, a radiomic nomogram was constructed and its performance was assessed by receiver operating characteristic (ROC) curves and calibration plots. The comparison of ROC curves was performed with DeLong's test. RESULTS: A combined nomogram model of the thyroid tumor and peritumoral interstitium was constructed based on the Rad-score, tumor location, maximum diameter, and T stage, and it had areas under the ROC curve of 0.956 (95% confidence interval [CI] = 0.913-1.000) and 0.876 (95% CI = 0.741-1.000) in the training and validation cohorts, respectively. Decision curve analysis suggested that the combined nomogram model had better clinical usefulness than the other models. CONCLUSION: A CT-based radiomics nomogram incorporating the radiomic signature and the selected clinical predictors can be a reliable approach to preoperatively predict the LNM status in patients with early-stage PTC, which is helpful for treatment decisions and prognosis.

Enhanced antitumor activity of inulin-capped Se nanoparticles synthesized using Jerusalem artichoke tubers.

An inulin polysaccharide with a molecular weight of ~ 2600 Da was derived from Jerusalem artichoke tubers and referred to as "JAP". Previous studies have shown that inulin can improve glucose tolerance and the liver lipid profile; however, its antitumor activity remains to be examined in detail. Therefore, to investigate the possible improvement of the antitumor activity of JAP, a novel nanostructured biomaterial was constructed by capping Se nanoparticles with JAP using sodium selenite, via a redox reaction with ascorbic acid, and referred to as "JAP-SeNPs". Transmission electron microscopy revealed that the average diameter of JAP-SeNPs is ~ 50 nm, and the C:Se mass ratio in JAP-SeNPs was found to be 15.4:1 by energy-dispersive X-ray spectroscopy. The well-dispersed JAP-SeNPs exhibited a significant in vitro antiproliferative effect on mouse forestomach carcinoma cells at a concentration of 400 µg/mL when incubated for 48 h, with an inhibition rate of 41.5%. Moreover, 38.9% of later apoptotic cells were observed. These results reveal that a combination of Se and JAP can effectively enhance the antitumor activity of polysaccharides obtained from Jerusalem artichoke tubers.

BMSC-Derived Exosomes Ameliorate Osteoarthritis by Inhibiting Pyroptosis of Cartilage via Delivering miR-326 Targeting HDAC3 and STAT1//NF-κB p65 to Chondrocytes.

BACKGROUND: In the past decade, mesenchymal stem cells (MSCs) have been widely used for the treatment of osteoarthritis (OA), and noncoding RNAs in exosomes may play a major role. AIM: The present study is aimed at exploring the effect and mechanism of miR-326 in exosomes secreted by bone marrow mesenchymal stem cells (BMSCs) on pyroptosis of cartilage and OA improvement. METHODS: Exosomes from BMSCs (BMSC-Exos) were isolated and identified to incubate with OA chondrocytes. Proliferation, migration, specific gene and miR-326 expression, and pyroptosis of chondrocytes were detected. BMSCs or chondrocytes were transfected with miR-326 mimics or inhibitors to investigate the effect of miR-326 in BMSC-Exos on pyroptosis of chondrocytes and the potential mechanism. Finally, a rat OA model was established to verify the effect and mechanism of miR-326 in BMSC-Exos on cartilage of pyroptosis. RESULTS: Incubation with BMSC-Exos could significantly improve the survival rate, migration ability, and chondrocyte-specific genes (COL2A1, SOX9, Agg, and Prg4) and miR-326 expression of OA chondrocytes and significantly inhibit pyroptosis of chondrocytes by downregulation of the levels of inflammatory cytokines, Caspase-1 activity, and pyroptosis-related proteins such as GSDMD, NLRP3, ASC, IL-1ß, and IL-18 (P < 0.01). PKH26 labeling confirmed the uptake of BMSC-Exos by chondrocytes. Incubation with exosomes extracted from BMSCs overexpressing miR-326 can significantly repress the pyroptosis of chondrocytes, while knockdown of miR-326 had the opposite effect (P < 0.01). The same result was also demonstrated by direct interference with the expression level of miR-326 in chondrocytes (P < 0.01). In addition, we found that the overexpression of miR-326 significantly inhibited the expression of HDAC3 and NF-κB p65 and significantly promoted the expression of STAT1, acetylated STAT1, and acetylated NF-κB p65 in chondrocytes (P < 0.01). The targeted relationship between miR-326 and HDAC3 was verified by dual-luciferase reporter assay. Animal experiments confirmed the mechanism by which miR-326 delivered by BMSC-Exos inhibits pyroptosis of cartilage by targeting HDAC3 and STAT1/NF-κB p65 signaling pathway. CONCLUSION: BMSC-Exos can deliver miR-326 to chondrocytes and cartilage and improve OA by targeting HDAC3 and STAT1//NF-κB p65 to inhibit pyroptosis of chondrocytes and cartilage. Our findings provide a new mechanism for BMSC-Exos to treat OA.

Carbon Nanoparticles Inhibit Α-Glucosidase Activity and Induce a Hypoglycemic Effect in Diabetic Mice.

New, improved therapies to reduce blood glucose are required for treating diabetes mellitus (DM). Here, we investigated the use of a new nanomaterial candidate for DM treatment, carbon nanoparticles (CNPs). CNPs were prepared by carbonization using a polysaccharide from Arctium lappa L. root as the carbon source. The chemical structure and morphology of the CNPs were characterized using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, elemental analysis, and transmission electron microscopy. CNPs were spherical, 10-20 nm in size, consisting of C, H, O, and N, and featuring various functional groups, including C=O, C=C, C-O, and C-N. In vitro, the as-prepared CNPs could inhibit α-glucosidase with an IC50 value of 0.5677 mg/mL, which is close to that of the reference drug acarbose. Moreover, in vivo hypoglycemic assays revealed that the CNPs significantly reduced fasting blood-glucose levels in mice with diabetes induced by high-fat diet and streptozocin, lowering blood glucose after intragastric administration for 42 days. To the best of our knowledge, this is the first report of CNPs exhibiting α-glucosidase inhibition and a hypoglycemic effect in diabetic mice. These findings suggest the therapeutic potential of CNPs for diabetes.

Up-Regulation of TGF-ß Promotes Tendon-to-Bone Healing after Anterior Cruciate Ligament Reconstruction using Bone Marrow-Derived Mesenchymal Stem Cells through the TGF-ß/MAPK Signaling Pathway in a New Zealand White Rabbit Model.

BACKGROUND/AIMS: This study aimed to explore the role of TGF-ß in tendon-to-bone healing after anterior cruciate ligament (ACL) reconstruction using bone marrow-derived mesenchymal stem cells (BMSCs) through the TGF-ß/MAPK signaling pathway in a New Zealand white rabbit model. METHODS: A total of 72 healthy male New Zealand white rabbits were selected for these experiments. Flow cytometry and immunofluorescence were used to detect the expression of BMSC surface markers, and qRT-PCR was performed to detect TGF-ß mRNA expression. The ACL reconstruction model was established with autografts. The rabbits were randomly divided into the following groups: inhibition of TGF-ß (inhibition), over-expression of TGF-ß (over-expression), empty vector and untreated (n = 18 per group). Hematoxylineosin (HE) staining, toluidine blue staining and Masson trichrome staining were conducted to observe any chondrocyte-like cell growth, and biomechanical tests were used to calculate the maximum load and rigidity. Three-dimensional CT imaging and Western blotting were applied to detect changes in bone tunnel size and bone density and the expression levels of TGF-ß/MAPK signaling pathway-related proteins, respectively. RESULTS: CD90 and CD44 were positively expressed, while CD11b was not detected. Compared with the empty vector and untreated groups, TGF-ß mRNA expression was significantly decreased in the inhibition group but increased in the over-expression group; the latter group had a larger number of fibroblasts, a tighter tendon-bone interface, an increased number of chondrocyte-like cells and fibrochondrocytes, and more collagen fibers than the inhibition, empty vector and untreated groups. Compared with the empty vector and untreated groups, the maximum load and rigidity; the CT values of bone tunnel and bone tunnel margin; and the protein expression levels of TGF-ß, p-ERK1/2, p-p38, p-JNK, c-jun and c-myc were significantly down-regulated in the inhibition group but up-regulated in the over-expression group. CONCLUSION: Our study indicated that up-regulating TGF-ß expression in BMSCs from New Zealand white rabbits could promote tendon-to-bone healing after ACL reconstruction by regulating the TGF-ß/MAPK signaling pathway.

UBE2I regulates the nuclear translocation of hnRNPA2B1 by contributing to SUMO modification in osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a progressive condition affecting the joints that lacking effective therapy. However, the underlying molecular mechanism has not been fully clarified. METHODS: A model of OA was established in Sprague-Dawley (SD) rats through intra-articularly injected with monoiodoacetate (MIA). Western blot analysis was used to identify the levels of UBE2I and hnRNPA2B1 in articular cartilage. Overexpression and siRNA vectors for UBE2I were constructed and transfected into rat chondrocytes. CCK-8, TUNEL and transwell assay were utilized to assess the cell viability, apoptosis and migration ability. Western blot analysis was used to determine the levels of chondrogenic-specific genes including SOX9, COL2A1, Aggrecan, and PRG4. Then, molecular interactions were confirmed by immunoprecipitation. RESULTS: We observed significant upregulation of UBE2I and hnRNPA2B1 expression in articular cartilage samples of OA. The Pearson correlation analysis revealed positive correlation between UBE2I and hnRNPA2B1 levels. Functional experiments showed that increased UBE2I expression significantly suppressed cell growth, migration, and reduced the expression of chondrogenic-specific genes, while decreasing UBE2I levels had the opposite effects. Molecular interactions between UBE2I and hnRNPA2B1were determined via co-localization and immunoprecipitation. SUMO1 and SUMO3 proteins were enriched by immunoprecipitation using hnRNPA2B1 antibodies. Rescue experiments were performed using SUMOylation inhibitor (2-D08) and SUMOylation activator (N106). Overexpression of UBE2I increased the expression of hnRNPA2B1 in the cytoplasm and decreased the level in the nucleus, which was reversed by the treatment of 2-D08. Conversely, UBE2I knockdown and N106 treatment had the opposite effect. CONCLUSIONS: UBE2I modulated the nuclear translocation of hnRNPA2B1 by promoting SUMOylation in OA.

Molecular cloning, sequence identification and expression analysis of novel caprine MYLPF gene.

Skeletal muscle genes are important potentially functional candidate genes for livestock production and meat quality. Myosin regulatory light chain (MLC) regulates myofilament activation via phosphorylation by Ca(2+) dependent myosin light chain kinase. The cDNA of the myosin light chain, phosphorylatable, fast skeletal muscle (MYLPF) gene from the longissimus dorsi of Tianfu goat was cloned and sequenced. The results showed that MYLPF full-length coding sequence consists of 513 bp and encodes 170 amino acids with a molecular mass of 19.0 kD. Two EF-hand superfamily domain of MYLPF gene conserved between caprine and other animals. The deduced amino acid sequence of MYLPF shared significant identity with the MYLPF from other mammals. A phylogenetic tree analysis revealed that the caprine MYLPF protein has a close genetic relationship and evolutional distance with MYLPF in other mammals. Analysis by RT-PCR showed that the MYLPF mRNA was detected in heart, liver, spleen, lung, kidney, gastrocnemius, abdominal muscle and longissimus dorsi. In particular, high expression levels of MYLPF mRNA were detected in the longissimus dorsi, gastrocnemius and abdominal muscle, and low level of expressions were observed in liver, spleen, lung and kidney. In addition, the temporal expression analysis further showed MYLPF expression decreased gradually with age in the skeletal muscle. This may be important as muscle growth occurs mainly in young age in goats. Western blotting results detected the MYLPF protein in four of the tissues in which MYLPF was shown to be expressed; the four exceptions were liver, spleen, lung and kidney.

Improved arthroscopic high-strength suture fixation for the treatment of posterior cruciate ligament avulsion fracture.

Background: To investigate the curative effects of improved non-absorbable high-strength fixation under arthroscopy on posterior cruciate ligament (PCL) avulsion fracture. Methods: A retrospective analysis was performed on 16 cases of PCL avulsion fracture in 15 patients who underwent high-strength suture fixation under arthroscopy from December 2017 to November 2019. According to the Meyers-McKeever classification, there were 2 cases of type II and 14 cases of type III. The fracture was reduced under arthroscopy, and knotted and fixed under the anterior and medial skin of the knee joint with high-strength sutures and a button plate. Regular follow-up of the knee joint healing and stability, the range of motion and the functional recovery of affected limb was conducted. The last follow-up was completed after the button plate was taken out. The Lysholm score was used to assess the recovery situation. Results: The button plate was taken out 6-9 months (average 7.2 months) after surgery. At the last follow-up, the fractures of the 15 patients were all healed. Moreover, six patients were positive for posterior drawer test within Grade 1 and the others were negative. All patients had no knee extension limitation, and the range of knee flexion reached more than 120°, with an average of (132.4 ± 3.6)°. The average Lysholm score was (93.1 ± 4.7). There were significant differences in knee flexion angle and Lysholm score at different time points after operation, p = 0.000. Conclusion: For the treatment of PCL avulsion fracture, the optimized arthroscopic high-strength suture fixation is easy to perform and repeat, and the fixation is strong and solid. The functions of the knee joint experienced good recovery after the surgery.

How to Frame Destination Foodscapes? A Perspective of Mixed Food Experience.

Foodscape conceptualizes the dynamic human-food-place nexus. Tourism provides a cross-cultural context where tourists can consume different destination foods and places, during which multiple types of destination foodscapes are produced. However, few studies explore how to frame the types and connotations of destination foodscape. Tourists' travelogues provide a rich database to examine this question. Through netnography, this study collects and analyzes 86 posts of travelogues published from 2012 to 2019 in Mafengwo, a famous Chinese online travel community, about Chinese tourists' food experiences in Chiang Mai, Thailand. We summarize five types of destination foodscapes, globalized recreational foodscape, staged local foodscape, glocalized foodscape, authentic local foodscape, and overseas ethnic foodscape in which tourists obtain different familiar-novelty hybrid experiences. This study contributes to interdisciplinary dialogue between food and tourism literature by proposing a coordinate framework with two axes, the spectrum of cultural distance and the spectrum of serving tourists/locals, to classify destination foodscape and a six-dimensional network construct to reveal the connotations of destination foodscape. Relevant strategies for promoting destination food and tourism development are also provided.

The Escalating Effects of Wildlife Tourism on Human-Wildlife Conflict.

Human-wildlife conflict is a barrier to achieving sustainable biodiversity conservation and community development in protected areas. Tourism is often regarded as a tool to mitigate such conflict. However, existing studies have mainly adopted a socio-economic perspective to examine the benefits of tourism for communities, neglecting the ecological effects of tourism. This case study of macaque tourism on a peninsula in China illustrates that tourism can escalate rather than mitigate human-wildlife conflict. Fifty-three stakeholders were interviewed and secondary data were collected to understand the development of rhesus macaque (Macaca mulatta) tourism and community-macaque conflict. The results show that food provision and tourist-macaque interactions rapidly increased the macaques' population, habituation, and aggressive behaviors, which led them to invade the surrounding community more often and exacerbated human-macaque conflict. Meanwhile, low community participation in tourism generated few benefits for residents and did not help alter residents' hostile attitudes towards the macaques. Local residents gradually retreated from agriculture as the macaques became more intrusive. A holistic approach to evaluating the role of wildlife tourism in resolving community-wildlife conflict is proposed and practical suggestions for alleviating such conflict are given.

Health tourism destinations as therapeutic landscapes: Understanding the health perceptions of senior seasonal migrants.

Health-driven seasonal tourism has become a new way of providing for the aged, which demonstrates a profound relationship between place and health. Therapeutic landscapes strongly suggest a causal relationship between health tourism destination and individual health. However, the quantitative validation of such relationship remains neglected and possible mechanisms underlying the relationship lack a strong theoretical basis. Based on therapeutic landscape theory and the REPLACE framework, this study quantitatively examines health promotion mechanisms of health tourism destinations by using data collected in Sanya, China, in January 2019. The effect of personal traits of dispositional optimism on health perceptions is also considered. The results show that physical, social, and symbolic landscapes positively influence health perceptions through restorative experiences. Social landscapes, symbolic landscapes and dispositional optimism positively affect health perception, while physical landscapes do not directly have a significant impact on health perception. It is expected that this study will fill the knowledge gap and advance our knowledge of therapeutic landscapes by exploring how they can influence health.

Val109Asp Polymorphism of the Omentin-1 Gene and Incidence of Knee Osteoarthritis in a Chinese Han Population: A Correlation Analysis.

OBJECTIVE: To investigate the correlation of the Val109Asp polymorphism of the omentin-1 gene with the risk and severity of knee osteoarthritis (KOA) in a Chinese Han population. METHODS: This study enrolled 383 patients with primary KOA and 460 healthy controls. The genotypes were determined by the detection of single nucleotide polymorphism. To explore the interaction between omentin-1 gene polymorphism and obesity and age, the body mass index (BMI) of 25 kg/m2 and the age of 55 years old were preset as the cut-off value of stratified analysis. Furthermore, enzyme-linked immunosorbent assay was used to determine the levels of omentin-1, interleukin (IL)-1ß, IL-6 in peripheral blood and synovial fluid and the contents of IL-1ß, IL-6, metalloproteinase (MMP)-13 and collagen (COL)-II in the supernatant of knee joint cartilage tissue. RESULTS: The Val109Asp polymorphism of the omentin-1 gene showed no obvious correlation with KOA. Compared with Asp/Asp genotype carriers with BMI <25 kg/m2 and age <55 years old, Val109 allele carriers with BMI≥25 kg/m2 and age ≥55 years old had obviously increased risk of KOA (adjusted OR = 1.416, p = 0.042; adjusted OR = 1.735, p = 0.038, respectively). In the KOA group, only the omentin-1 levels were significantly lower in the plasma and synovial fluid of Ala/Ala genotype carriers than in those of Asp/Asp genotype carriers. Meanwhile, the proportion of patients with moderate-severe K-L Classification, the levels of IL-1ß, IL-6 in synovial fluid and the expression levels of IL-1ß, IL-6 and MMP-13 in cartilage tissue significantly increased (p < 0.05). By contrast, the expression level of COL-II in cartilage tissue significantly decreased (p < 0.05). CONCLUSIONS: The Val109Asp polymorphism of the omentin-1 gene may not be the primary pathogenic factor of KOA in Chinese. The Val/Val genotype can be regarded as a potential biomarker for the risk of KOA progression.

[Increased proportion and abnormal phenotype of NK cells in peripheral blood of patients with knee osteoarthritis].

Objective To investigate the distribution and phenotypic characteristics of natural killer (NK) cells in the peripheral blood of knee osteoarthritis (KOA) patients. Methods Flow cytometry was used to detect and compare the distribution of NK cells and the expression of their surface functional receptors in the peripheral blood of healthy controls without KOA and patients with KOA, such as human leukocyte antigen DR (HLA-DR) and natural cytotoxicity receptor 3 (NCR3/NKP30). Results The proportion of NK cells in the peripheral blood of KOA patients was significantly up-regulated, especially CD16bright NK cells. The expression of HLA-DR molecules on the surface of NK cells with KOA was up-regulated, while the expression of NKP30 was significantly down-regulated. Conclusion The proportion of NK cells in the peripheral blood of KOA patients increases, and the cells show the up-regulated expression of CD16 and HLA-DR and the down-regulated expression of NKP30.

Therapeutic landscapes and longevity: Wellness tourism in Bama.

Due to the rising demand for healthcare products and concern over environmental pollution, wellness tourism has been booming in China in recent years. The therapeutic landscape theory provides a multi-scale interpretation of wellness tourism to explore how wellness tourists achieve health in healing places. By presenting the results of 83 interviews conducted in Bama, China, this study reveals that the "longevity village" Bama, endorsed by centenarians, provides a retreat that combines natural beauty and a harmonious neighbourhood for wellness tourists. This article argues that although three themes-natural environment, social interaction and symbolic landscape-work together in the healing process of tourists, the symbolic landscape, which is significantly shaped by the longevity culture, plays a dominant role. Longevity in Chinese culture symbolizes the alignment of a strong body, graceful mind, and pleasant habitat. Furthermore, tourism reinforces the importance of symbols and imagination (of a place), the perception of longevity demonstrates the symbolic landscape and thus increases tourists' attachment to the place, and the unusual environment leads to a different therapeutic landscape from that of daily life. Finally, since to date there has been very few works on therapeutic landscapes in China, it is expected that this study will fill the knowledge gap and broaden the scope of application as well as conceptualization of the therapeutic landscape.

Seasonal mobility and well-being of older people: The case of 'Snowbirds' to Sanya, China.

Seasonal retired migrants have increased rapidly in developing countries in recent years. This article adopts a relational perspective to understand the relationships between older people's seasonal mobility and well-being. It shows that the complex spatiotemporal dynamics of seasonal mobility and the non-western sociocultural context influence older people's relations with their places of origin and destination, which in turn shape their well-being experiences during seasonal mobility. Narrative analysis of interview data from five pairs of 'snowbirds' to Sanya, China, reveals that seasonal mobility and well-being of older people are evolving processes, interwoven with risks and opportunities. Older people construct routinized daily activities, stable social relations, and peer-supporting and active-aging environments in their place of destination to maintain short-term well-being. However, they encounter difficulties in integrating the corporeal and social dimensions of their bodily experiences and constructing long-term well-being due to their separations from their lifelong relations in their places of origin. But overall, seasonal mobility creates alternative options for aging across multiple places and promotes leisure-oriented aging life.

TGF-ß1 promoted chondrocyte proliferation by regulating Sp1 through MSC-exosomes derived miR-135b.

OBJECTIVE: The aim of this study was to investigate the molecular mechanism of TGF-ß1 in regulating chondrocyte proliferation through MSC-exosomes. METHODS: An osteoarthritis (OA) rat model was established. Cartilage degradation was quantified by using OARSI score. TGF-ß1 was used to stimulate MSCs. The expressions of miR-135b and Sp1 in MSCs, MSC-exosomes and C5.18 cells were detected. The cell viability of C5.18 cells was measured using MTT assay. RESULTS: TGF-ß1 stimulation enhanced miR-135b expression in MSC-exosomes, and MSC-exosomes derived miR-135b increased the cell viability of C5.18 cells. Moreover, miR-135b negatively regulated Sp1 expression. The cell viability of C5.18 cells in TGF-ß1+miR-135b inhibitor+si-control group was reduced, while the cell viability in TGF-ß1+miR-135b inhibitor+si-Sp1 group was enhanced. In rat experiments, OARSI score was decreased and the number of chondrocytes was increased in OA+TGF-ß1+MSC-exosome group, while the score and the number had an opposite trend in OA+TGF-ß1+MSC-miR135b inhibitor-exosome group. CONCLUSION: TGF-ß1 promoted chondrocyte proliferation by regulating Sp1 through MSC-exosomes derived miR-135b, then promoted cartilage repair.