Retinal microcirculatory disorder is a key factor in the occurrence and development of diabetic retinopathy （DR）， and also an important link in the prevention and treatment of DR. The theory of "Gaozhuo" holds that the microcirculatory disorder in DR is based on the deficiency of spleen Qi and is characterized by the obstruction caused by "Gaozhuo" and blood stasis. The deficiency of spleen Qi is an essential precondition for the endogenous formation and accumulation of Gaozhuo， while Gaozhuo invasion is the direct cause of microcirculatory disorders in DR. The deficiency of spleen Qi and the endogenous formation of Gaozhuo mean the process in which glucose metabolism dysfunction induces an excessive production of inflammatory factors and lipid metabolites. The obstruction caused by "Gaozhuo" and blood stasis is the direct pathogenesis of microcirculatory disorders in DR， encompassing two stages： Gaozhuo obstruction and turbidity and stasis stagnation. Gaozhuo obstruction and turbidity and stasis stagnation represent the process in which inflammatory factors and lipid metabolites damage the retinal microcirculation and induce thrombosis， thus mediating microcirculatory disorders. Turbidity and stasis stagnation and blood extravasation outside the vessels reveal the progression to microvascular rupture and hemorrhage resulting from the microcirculatory disorders. According to the pathogenesis evolution of the theory of "Gaozhuo"， microcirculatory disorders in DR can be divided into deficiency of spleen Qi with Gaozhuo obstruction， deficiency of spleen Qi with turbidity and stasis stagnation， and turbidity and stasis stagnation with blood extravasation outside the vessels. Clinically， treatment principles should focus on strengthening the spleen and benefiting Qi， resolving turbidity， and dispersing stasis. Different syndrome patterns should be addressed with tailored therapies， such as enhancing the spleen and benefiting Qi while regulating Qi and reducing turbidity， strengthening the spleen and benefiting Qi while resolving turbidity and dispelling stasis， and strengthening the spleen and resolving turbidity while removing stasis and stopping bleeding. Representative prescriptions include modified Wendantang， modified Buyang Huanwutang， modified Danggui Buxuetang， Zhuixue Mingmu decoction， Tangmuqing， Shengqing Jiangzhuo Tongluo Mingmu prescription， Danhong Huayu decoction， and Yiqi Yangyin Huoxue Lishui formula.

ObjectiveTo investigate the ameliorative effects and related mechanisms of the Zuogui Jiangtang Shuxin prescription （ZJSP） on glucose and lipid metabolism disorders in MKR mice with diabetic cardiomyopathy （DCM）， with a focus on elucidating its regulatory role on the adenosine monophosphate-activated protein kinase （AMPK）/forkhead box protein O1 （FoxO1）/cluster of differentiation 36 （CD36） signaling pathway and lipid deposition. MethodsFifty 8-week-old male MKR mice were fed a high-fat diet for four weeks and then intraperitoneally injected with streptozotocin （STZ） while maintaining a high-fat diet to establish a DCM model. The mice were randomly divided into the model group， the low-dose（14.43 g·kg^-1）and high-dose（28.86 g·kg^-1） ZJSP groups， and the metformin group （0.25 g·kg^-1）， with age-matched FVB mice as a normal control group. Each group received intragastric administration of normal saline or corresponding concentrations of ZJSP at equal volumes. After four weeks， fasting blood glucose （FBG） and cardiac function were measured. Blood was collected from the eyeballs under anesthesia to detect fasting insulin （FINS） and blood lipid levels. Myocardial tissue morphology was observed by hematoxylin-eosin （HE） staining， and lipid deposition in the heart was assessed using oil red O staining. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the mRNA expression levels of AMPK， FoxO1， and CD36 in myocardial tissues. Western blot was employed to detect the protein expression levels of AMPK， p-AMPK， FoxO1， p-FoxO1， and CD36. ResultsCompared with the control group， the model group showed significantly increased levels of FBG and FINS （P<0.01）， elevated levels of triglycerides （TG）， total cholesterol （TC）， and low-density lipoprotein cholesterol （LDL-C） （P<0.01）， and significantly decreased left ventricular ejection fraction （EF） and fractional shortening （FS） values （P<0.01）. HE staining revealed marked cardiomyocyte hypertrophy， disarray， and widened intercellular spaces in myocardial tissues. Oil Red O staining showed extensive red deposition areas and fine lipid droplet accumulation in the myocardial tissue. AMPK mRNA expression was decreased， while FoxO1 and CD36 mRNA expressions were significantly increased （P<0.01）. The p-AMPK/AMPK protein expression ratio in myocardial tissues was significantly reduced， while the p-FoxO1/FoxO1 protein expression ratio and CD36 protein expression levels were significantly increased （P<0.01）. Compared with the model group， all treatment groups exhibited significantly reduced FBG （P<0.01）， decreased FINS and blood lipid levels （TG， TC， LDL-C） （P<0.05， P<0.01）， improved cardiac function （P<0.05）， noticeable amelioration of myocardial histopathological morphology and lipid deposition， increased AMPK mRNA expression （P<0.01）， with significantly downregulated FoxO1 and CD36 mRNA expressions （P<0.01）， elevated p-AMPK/AMPK protein expression levels in myocardial tissue （P<0.05）， significantly decreased p-FoxO1/FoxO1 ratios （P<0.01）， and downregulated CD36 protein expression levels （P<0.05， P<0.01）. ConclusionZJSP exerts a protective effect on the heart in type 2 DCM of MKR mice， and its mechanism may be associated with the regulation of the AMPK/FoxO1/CD36 signaling pathway.

ObjectiveTo investigate the ameliorative effects and related mechanisms of the Zuogui Jiangtang Shuxin prescription （ZJSP） on glucose and lipid metabolism disorders in MKR mice with diabetic cardiomyopathy （DCM）， with a focus on elucidating its regulatory role on the adenosine monophosphate-activated protein kinase （AMPK）/forkhead box protein O1 （FoxO1）/cluster of differentiation 36 （CD36） signaling pathway and lipid deposition. MethodsFifty 8-week-old male MKR mice were fed a high-fat diet for four weeks and then intraperitoneally injected with streptozotocin （STZ） while maintaining a high-fat diet to establish a DCM model. The mice were randomly divided into the model group， the low-dose（14.43 g·kg^-1）and high-dose（28.86 g·kg^-1） ZJSP groups， and the metformin group （0.25 g·kg^-1）， with age-matched FVB mice as a normal control group. Each group received intragastric administration of normal saline or corresponding concentrations of ZJSP at equal volumes. After four weeks， fasting blood glucose （FBG） and cardiac function were measured. Blood was collected from the eyeballs under anesthesia to detect fasting insulin （FINS） and blood lipid levels. Myocardial tissue morphology was observed by hematoxylin-eosin （HE） staining， and lipid deposition in the heart was assessed using oil red O staining. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the mRNA expression levels of AMPK， FoxO1， and CD36 in myocardial tissues. Western blot was employed to detect the protein expression levels of AMPK， p-AMPK， FoxO1， p-FoxO1， and CD36. ResultsCompared with the control group， the model group showed significantly increased levels of FBG and FINS （P<0.01）， elevated levels of triglycerides （TG）， total cholesterol （TC）， and low-density lipoprotein cholesterol （LDL-C） （P<0.01）， and significantly decreased left ventricular ejection fraction （EF） and fractional shortening （FS） values （P<0.01）. HE staining revealed marked cardiomyocyte hypertrophy， disarray， and widened intercellular spaces in myocardial tissues. Oil Red O staining showed extensive red deposition areas and fine lipid droplet accumulation in the myocardial tissue. AMPK mRNA expression was decreased， while FoxO1 and CD36 mRNA expressions were significantly increased （P<0.01）. The p-AMPK/AMPK protein expression ratio in myocardial tissues was significantly reduced， while the p-FoxO1/FoxO1 protein expression ratio and CD36 protein expression levels were significantly increased （P<0.01）. Compared with the model group， all treatment groups exhibited significantly reduced FBG （P<0.01）， decreased FINS and blood lipid levels （TG， TC， LDL-C） （P<0.05， P<0.01）， improved cardiac function （P<0.05）， noticeable amelioration of myocardial histopathological morphology and lipid deposition， increased AMPK mRNA expression （P<0.01）， with significantly downregulated FoxO1 and CD36 mRNA expressions （P<0.01）， elevated p-AMPK/AMPK protein expression levels in myocardial tissue （P<0.05）， significantly decreased p-FoxO1/FoxO1 ratios （P<0.01）， and downregulated CD36 protein expression levels （P<0.05， P<0.01）. ConclusionZJSP exerts a protective effect on the heart in type 2 DCM of MKR mice， and its mechanism may be associated with the regulation of the AMPK/FoxO1/CD36 signaling pathway.

[摘 要] 目的：探讨同源异型盒蛋白D11（HOXD11）对Ki-67的转录调控作用及其对喉鳞状细胞癌（LSCC）细胞恶性生物学行为的影响和机制。方法：结合高通量测序数据，通过GEO、UALCAN数据库分析HOXD11在LSCC中差异表达。收集2022年1月至2025年1月联勤保障部队第九八〇医院手术切除的60例LSCC患者的癌及癌旁组织标本，以及人LSCC细胞系AMC-HN-8、TU-177、TU-686和人正常喉上皮细胞（HNLEC），构建敲低或过表达HOXD11的细胞系，将细胞分为对照组、HOXD11敲低组及HOXD11过表达组。通过RT-qPCR法检测HOXD11和Ki-67基因在LSCC组织和细胞中mRNA表达水平，免疫组织化学（IHC）法分析两者在LSCC组织中的蛋白表达及分布，WB法进一步验证蛋白差异表达。采用MTS、克隆形成实验及Transwell实验分别检测敲低或过表达HOXD11对LSCC细胞增殖、迁移与侵袭的影响。通过双萤光素酶报告基因实验和染色质免疫沉淀（ChIP）实验验证HOXD11对Ki-67启动子活性的调控作用。结果：GEO和UALCAN数据库分析表明，HOXD11在LSCC中高表达（P < 0.01）。在LSCC组织中HOXD11和Ki-67 mRNA和蛋白表达均显著高于癌旁组织（均P < 0.01），同时，两者表达水平之间存在正相关（r = 0.26，P < 0.05）；LSCC细胞系中HOXD11 mRNA表达显著高于HNLEC（均P < 0.01）。敲低HOXD11显著抑制LSCC细胞的增殖、迁移和侵袭能力（均P < 0.01），而过表达HOXD11则促进细胞的这些恶性生物学行为（均P < 0.01）。双萤光素酶报告基因实验及ChIP实验均证实，HOXD11可直接结合到Ki-67启动子区上，调控其表达（P < 0.01）。回复实验显示，过表达Ki-67可部分逆转敲低HOXD11对LSCC细胞增殖、迁移与侵袭的抑制作用（均P < 0.01）。结论：HOXD11在LSCC组织及细胞系中均呈高表达，其机制在于通过直接调控Ki-67的转录活性，从而增强LSCC细胞的增殖、迁移及侵袭能力。

Objective: To systematically review the effect of physical activity (PA) on health related quality of life (HRQoL) among children and adolescents and the magnitude of association, so as to provide an evidence based support for optimizing health promotion strategies for children and adolescents. Methods: Medline (PubMed), EMBASE, the Cochrane Library, SCIELO, PEDro, CNKI, Wanfang and VIP databases were searched to collect literature on PA and HRQoL in children and adolescents, which were published up to January 1, 2025. Cochrane ROB tool and specific evaluation system were used to assess literature quality, Stata 16.0 software was used for Meta analysis. For descriptive studies, correlation( r ) and 95% confidence interval( CI ) were used as effect indicators, and the inverse variance method was used to merge the data. Standardized mean difference( SMD ) and 95% CI were used to calculate the combined effect size of intervention studies. Results: A total of 22 studies involving 27 303 healthy children and adolescents were included, including 9 descriptive studies and 13 intervention studies. The results of descriptive analysis showed that PA level was positively correlated with HRQoL ( r =0.27, 95% CI =0.21-0.32, P <0.01). The analysis of intervention studies showed that PA had significant effects on overall HRQoL ( SMD =0.10, 95% CI =0.05-0.16), physical functioning ( SMD =0.16, 95% CI =0.08-0.23), and mental functioning ( SMD =0.17, 95% CI =0.10-0.25)( P <0.01). Subgroup analysis found that the effects of physical activity on overall HRQoL, physiological function, and psychological function in children and adolescents were maximized when the intervention duration was less than 6 months ( SMD =0.13, 0.18, 0.20), the frequency was≥5 times per week ( SMD =0.13, 0.19, 0.24) and there was a supplementary plan( SMD =0.10, 0.18, 0.23)( P <0.01). Conclusion PA is an important factor affecting the HRQoL of healthy children and adolescents, and the systematic PA intervention has a effect on improving the HRQoL.

Objective: To explore the association of physical activity and sugar sweetened beverage consumption with psychological sub health among middle school students in Bao an District, Shenzhen, so as to provide a reference for adolescent mental health promotion. Methods: A questionnaire survey was conducted in November 2024 by a stratified cluster random sampling method to select 6 926 junior and senior middle school students from 5 middle schools in Shenzhen. The questionnaire from Youth Risk Behavior Surveillance System was used to assess the consumption of sugar sweetened beverages, and physical activity Rating Scale was used to assess the level of physical activity, and Brief Instrument on Psychological Health of Youths was used to evaluate the psychological sub health status. The Chi -square test was used to analyze the differences in the detection rates of psychological sub health among different groups of middle school students, and a multivariate Logistic regression model was established to analyze the effects of physical activity and sugar sweetened beverage consumption and their combined effects on the psychological sub health of middle school students. Results: The detection rate of psychological sub health among middle school students in Bao an District, Shenzhen was 18.93%. Multivariate Logistic regression analysis showed that, after controlling for confounding factors such as gender, school stage, family residence, family economic status, parental literacy, academic stress and number of friends, lack of physical activity or excessive sugar sweetened beverage consumption were associated with increased risks of psychological sub health among middle school students ( OR =1.36, 1.45); and the highest risk of psychological sub health was found in middle school students who were lack of physical activity and excessive sugar sweetened beverage consumption ( OR =2.59) ( P <0.01). Further analysis by school stages showed that junior high school students with sufficient physical activity and excessive intake of sugary drinks ( ROR =2.10), lack of physical activity and excessive intake of sugary drinks ( ROR =2.31) were at higher risks of psychological sub health than senior high school students( P <0.05). Conclusions Insufficient physical activity and excessive sugar sweetened beverage consumption are closely associated with an increased risk of psychological sub health among middle school students. Effective interventions should be targeted to reduce the risk of psychological sub health problems among middle school students.

Hepatic stellate cells (HSCs) are the primary fibrogenic cells in the liver, and their activation plays a crucial role in the development and progression of hepatic fibrosis. Here, we report that retinoid X receptor-alpha (RXRα), a unique member of the nuclear receptor superfamily, is a key modulator of HSC activation and liver fibrosis. RXRα exerts its effects by modulating calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ)-mediated activation of AMP-activated protein kinase-alpha (AMPKα). In addition, we demonstrate that K-80003, which binds RXRα by a unique mechanism, effectively suppresses HSC activation, proliferation, and migration, thereby inhibiting liver fibrosis in the CCl₄ and amylin liver NASH (AMLN) diet animal models. The effect is mediated by AMPKα activation, promoting mitophagy in HSCs. Mechanistically, K-80003 activates AMPKα by inducing RXRα to form condensates with CaMKKβ and AMPKα via a two-phase process. The formation of RXRα condensates is driven by its N-terminal intrinsic disorder region and requires phosphorylation by CaMKKβ. Our results reveal a crucial role of RXRα in liver fibrosis regulation through modulating mitochondrial activities in HSCs. Furthermore, they suggest that K-80003 and related RXRα modulators hold promise as therapeutic agents for fibrosis-related diseases.

OBJECTIVE: To investigate the relationship between peripheral blood circular RNA Bardet-Biedl syndrome 9 (circBBS9) and circRNA catenin beta 1 (circCTNNB1) and weaning failure of mechanical ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). METHODS: A prospective, observational cohort study was conducted. The patients with AECOPD who received invasive mechanical ventilation and passed the spontaneous breathing test (SBT) admitted to the First Affiliated Hospital of Hebei North University from January 2022 to February 2024 were selected as the study subjects. According to the outcome of weaning, the patients were divided into failed weaning group and successful weaning group. At admission and before SBT, the expression levels of circBBS9 and circCTNNB1 in peripheral blood were detected by fluorescence quantitative polymerase chain reaction (PCR). General information, acute physiology and chronic health evaluation II (APACHEII) score within 24 hours of admission, vital signs before SBT and the most recent laboratory indicators before SBT of the patients were collected. The differences in circBBS9 and circCTNNB1 expression levels and clinical data between the two groups were compared. Multivariate Logistic regression was used to analyze the influencing factors of the weaning failure. Receiver operator characteristic curve (ROC curve) was used to analyze the predictive value of each index on weaning failure. RESULTS: Ultimately, 132 patients with AECOPD who underwent invasive mechanical ventilation and passed the SBT were enrolled in the study. Among them, 82 patients were successfully weaned from mechanical ventilation, while 50 patients failed to be weaned, resulting in a weaning failure rate of 37.88%. There was no statistically significant difference in the expression levels of circBBS9 and circCTNNB1 in the peripheral blood at admission of patients between the two groups. The expression level of circBBS9 in the peripheral blood before SBT of patients in the failed weaning group was significantly higher than that in the successful weaning group (2^-ΔΔCt: 131.64±30.24 vs. 100.00±21.32), and the expression level of circCTNNB1 was significantly lower than that in the successful weaning group (2^-ΔΔCt: 79.90±16.82 vs. 100.00±26.43), and the differences were statistically significant (both P < 0.05). The APACHEII score within 24 hours of admission and the levels of RSBI, SCr, and PCT before SBT in the failed weaning group were significantly higher than those in the successful weaning group [APACHEII score: 22.54±4.62 vs. 16.56±4.58, RSBI: 81.90±16.56 vs. 63.25±17.00, SCr (μmol/L): 100.20±17.27 vs. 89.93±26.29, PCT (μg/L): 1.08±0.18 vs. 0.87±0.22], and the Alb level before SBT was significantly lower than that in the successful weaning group (g/L: 29.71±2.73 vs. 33.93±2.89), and the differences were statistically significant (all P < 0.05). There was no statistically significant difference in other clinical data between the two groups. Multivariate Logistic regression analysis showed that circBBS9 [odds ratio (OR) = 1.291, 95% confidence interval (95%CI) was 1.049-1.588] and APACHEII score (OR = 2.897, 95%CI was 1.004-8.353), RSBI (OR = 1.413, 95%CI was 1.057-1.890) were independent risk factors for weaning failure (all P < 0.05), and circCTNNB1 (OR = 0.812, 95%CI was 0.688-0.959) and Alb (OR = 0.149, 95%CI was 0.036-0.614) were protective factors (both P < 0.05). ROC curve analysis showed that circBBS9, circCTNNB1, APACHEII score, RSBI, and Alb all had certain value for predicting weaning failure. The area under the ROC curve (AUC) and 95%CI were 0.820 (0.750-0.890), 0.755 (0.674-0.835), 0.827 (0.757-0.897), 0.795 (0.715-0.876), and 0.854 (0.791-0.919), respectively. Using the multivariate Logistic regression equation as the combined indicator, the AUC for predicting weaning failure reached 0.997 (95%CI was 0.993-1.000), which was significantly higher than that of the single indicators including circBBS9, circCTNNB1, APACHEII score, RSBI, and Alb (the Z value was 5.582, 6.093, 5.771, 5.932, and 5.182, respectively, all P < 0.05). CONCLUSIONS High expression of circBBS9 and low expression of circCTNNB1 in the peripheral blood of AECOPD patients receiving invasive mechanical ventilation before SBT are associated with weaning failure. circBBS9, circCTNNB1 combined with APACHEII score, RSBI and Alb are helpful for predicting the failure of weaning in these patients.
Humans ; Pulmonary Disease, Chronic Obstructive/blood* ; Prospective Studies ; Ventilator Weaning ; RNA, Circular/blood* ; Respiration, Artificial ; Male ; Female ; Aged

Objective To discuss the application of ultrasound multimodal diagnostic mode combined with ultrasonic precision interventional technology in differentiating the benign from malignant solid breast masses.Methods A total of 396 patients who underwent breast surgery at the Wuwei Cancer Hospital of China from May 2021 to July 2023 were enrolled in this study.Within 2 weeks before surgery,multimodal ultrasound examination(including two-dimensional ultrasound,color Doppler ultrasound,elastic ultrasound,breast three-dimensional ultrasound,and contrast-enhanced ultrasound)and ultrasound-guided needle biopsy were performed in all patients.The consistency between the results of multimodal ultrasound examination,ultrasound-guided needle biopsy,combination diagnosis and the postoperative pathological diagnoses was analyzed.Results Of the 396 patients with solid breast mass,malignant lesion was seen in 237(59.85％)and benign lesion was seen in 159(40.15％).The sensitivity of multimodal ultrasound in diagnosing benign and malignant solid breast masses was 77.64％(184/237),the specificity was 90.57％(144/159),the positive predictive value was 92.46％(184/199),the negative predictive value was 73.10％(144/197),the accuracy was 82.83％(328/396),and the consistency with the postoperative pathological diagnosis was 0.656.The sensitivity of ultrasound-guided needle puncture in diagnosing benign and malignant solid breast masses was 94.51％(224/237),the specificity was 100.00％(159/159),the positive predictive value was 100.00％(224/224),the negative predictive value was 92.44％(159/172),the accuracy was 96.72％(383/396),and the consistency with the postoperative pathological diagnosis was 0.933.The sensitivity of multimodal ultrasound combined with ultrasound-guided needle puncture in diagnosing benign and malignant solid breast masses was 100.00％(228/228),the specificity was 94.64％(159/168),the positive predictive value was 96.20％(228/237),the negative predictive value was 100.00％(159/159),the accuracy was 97.73％(387/396),and the consistency with the postoperative pathological diagnosis was 0.937.Conclusion The ultrasound multimodal diagnostic mode and ultrasonic precision interventional technology can be used in differentiating the benign from malignant solid breast masses with high diagnostic accuracy.

OBJECTIVE: To compare the short-term effectiveness between Gamma 3 intramedullary nails and Gamma 3 U-Blade system in the treatment of osteoporotic intertrochanteric fractures in the elderly. METHODS: A retrospective analysis was conducted on the clinical data of 124 elderly patients with osteoporotic intertrochanteric fractures, who were admitted between February 2020 and February 2023 and met the selection criteria. The fractures were fixed with Gamma 3 intramedullary nails in 65 patients (control group) and Gamma 3 U-Blade systems in 59 patients (UB group). The differences between the two groups were not significant in age, gender, body mass index, American Society of Anesthesiologists (ASA) classification, bone mineral density, time from injury to operation, fracture classification, and affected side ( P>0.05). The operation time, intraoperative blood loss, hospital stay, and fracture healing time were recorded; the tip-apex distance, fracture reduction quality, and lag screw position were evaluated on X-ray films at immediate after operation; the lag screw sliding distance and change value of neck-shaft angle were measured on X-ray films at last follow-up. Harris hip score at 1 year after operation and the occurrence of internal fixation-related complications were compared between the two groups. RESULTS: The operation time, intraoperative blood loss, and hospital stay in the UB group increased compared to the control group, but the differences were not significant ( P>0.05). All patients in both groups were followed up 12-24 months (mean, 17.1 months). At 12 months after operation, there was no significant difference in the Harris hip score between the two groups ( P<0.05). Radiological examination showed that there was no significant difference between the two groups ( P>0.05) in terms of tip-apex distance, fracture reduction quality, and lag screw position. Fractures healed in both groups, and there was no significant difference in healing time ( P>0.05). At last follow-up, the change value of neck-shaft angle and lag screw sliding distance in the UB group were significantly lower than those in the control group ( P<0.05). During follow-up, no related complications occurred in the UB group, while 6 cases (9.2%) in the control group experienced complications, and the difference in the incidence was significant ( P<0.05). CONCLUSION For the osteoporotic intertrochanteric fractures in the elderly, the Gamma 3 U-Blade system fixation can achieve good short-term effectiveness, with better imaging results compared to Gamma 3 intramedullary nails fixation.
Humans ; Retrospective Studies ; Hip Fractures/surgery* ; Male ; Female ; Aged ; Fracture Fixation, Intramedullary/methods* ; Osteoporotic Fractures/surgery* ; Bone Nails ; Bone Screws ; Aged, 80 and over ; Treatment Outcome ; Fracture Healing ; Operative Time ; Length of Stay