ObjectiveTo evaluate the therapeutic effects of Huanglian Jiedutang on cerebral infarction injury in a mouse model of middle cerebral artery occlusion （MCAO） and to explore its mechanism of action on oligodendrocytes， particularly its potential in myelin repair. MethodsMultiple experimental approaches were used to evaluate cerebral ischemic injury and the effects of drug intervention. Laser speckle imaging was used to detect changes in cerebral blood flow， 2，3，5-Triphenyltetrazolium chloride （TTC） staining was used to measure infarct volume， and neurological function was scored according to the Zea-Longa criteria. Brain tissues were routinely embedded in paraffin and subjected to HE and Nissl staining to observe tissue structure and neuronal damage. Animals were divided into a sham group （n=24）， model group （n=24）， Huanglian Jiedutang group （n=24）， and Ginkgo biloba extract （GBE） group （n=18）. After 1 week of acclimatization， intragastric administration was initiated. The sham and model groups received normal saline， the Huanglian Jiedutang group was administered 1.82 g·kg^-1， and the GBE group was administered 0.432 g·kg^-1 after preparation as a 2.16 g·L^-1 solution. All groups were treated for 5 consecutive days at a dose of 0.2 mL·（10 g）^-¹·d^-¹. The MCAO model was established after the final administration on day 6. Single-cell RNA sequencing was used to analyze brain tissue cellular composition and changes in oligodendrocyte subpopulations. Distinct subpopulations were identified by Uniform manifold approximation and projection （UMAP） dimensionality reduction and unsupervised clustering， and marker gene expression was analyzed. Pathway enrichment and causal inference were further performed using IPA. Finally， real-time quantitative PCR was used to verify mRNA expression changes of myelin-related genes. ResultsCompared with the sham group， the model group showed significantly increased neurological function scores （P<0.01）， significantly impaired blood flow （P<0.01）， significantly enlarged cerebral infarct area （P<0.01）， and pathological changes including disordered cortical structural arrangement， aggravated cytoplasmic vacuolization， and increased Nissl bodies. Compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly decreased neurological function scores （P<0.01）， markedly restored blood flow levels （P<0.01）， significantly reduced cerebral infarct area （P<0.01）， and improvement in cortical structural disorder， alleviation of cytoplasmic vacuolization， and a reduction in Nissl bodies. Single-cell data showed that a myelin-associated oligodendrocyte （Mye-OL） subpopulation existed among oligodendrocytes， which was closely related to myelin generation. Compared with the sham group， the number of Mye-OL cells decreased in the model group. Compared with the model group， the number of Mye-OL cells increased in the Huanglian Jiedutang group. This subpopulation promoted the expression of myelin-related genes， including MOG， MBP， and MAG， via transcription factors such as OLIG1， OLIG2， NKX2-2， and SOX10， thereby regulating myelin generation， restoring cognition， and exerting therapeutic effects on acute cerebral infarction. Compared with the sham group， the mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 were significantly downregulated in the model group （P<0.01）， and the mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG， were also significantly downregulated （P<0.01）. In contrast， compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly upregulated mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 （P<0.01）， and significantly upregulated mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG （P<0.01）. ConclusionHuanglian Jiedutang exerts therapeutic effects on acute cerebral infarction by regulating the OLIG1/2-NKX2-2-SOX10 signaling pathway to promote myelin generation by Mye-OL cells.

BackgroundPatients with chronic schizophrenia often suffer from cognitive impairment. Traditional cognitive rehabilitation training has problems such as a single form and poor compliance， making it urgent to develop new cognitive intervention methods. ObjectiveTo explore the intervention effect of smartphone games on the cognitive function of patients with chronic schizophrenia， and to analyze the differences in cognitive function improvement between patients of different genders， in order to provide references for the cognitive function intervention of these patients. MethodsThis study was a prospective cohort study. A total of 30 patients who were hospitalized in the Psychiatry Department of Chaohu Hospital Affiliated to Anhui Medical University from March to October 2021， met the diagnostic criteria for schizophrenia as defined in the International Classification of Diseases， tenth edition （ICD-10）， and had a disease duration of above 5 years， were selected as the research subjects. All patients received smartphone game intervention for 12 weeks， 5 times a week， each session lasting 1 hour， in addition to conventional antipsychotic drug treatment. At the baseline and at 3， 6， 9， and 12 weeks of the intervention， the cognitive function was evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status （RBANS）， the Positive and Negative Syndrome Scale （PANSS） was used to assess mental symptoms， and the Problematic Mobile Gaming Questionnaire （PMGQ） was used to assess addiction symptoms. ResultsA total of 26 patients （86.67%） completed the study， including 13 females and 13 males. The time effects， group effects， and interaction effect between time and group for the immediate memory factor score of RBANS in the female group and the male group were all statistically significant （F=36.682， 5.712， 3.090， P<0.05 or 0.01）， and the time effects and group effects for the verbal and delayed memory factors as well as the total score in both groups were also statistically significant （F=3.841， 6.149， 15.372， P<0.05 or 0.01）. The time effects and group effects of the total score of PANSS in both groups had no statistical significance （F=2.041， 0.623， P>0.05 for both）， and the interaction effect between time and group was statistically significant （F=5.728， P<0.01）. The time effects， group effects， and interaction effect of the total score of PMGQ in both groups were all without statistical significance （F=2.672， 0.166， 0.642， P>0.05 for both）. ConclusionSmartphone game intervention may help improve the cognitive function of patients with chronic schizophrenia （especially immediate memory， verbal function， and delayed memory）， and the benefits are greater for female patients. The smartphone game intervention did not induce game addiction， but no significant improvement in psychotic symptoms was observed. ［Funded by Excellent Young Talents Support Program of Anhui Provincial Department of Education （number， gxyqZD2022022）； www.chictr.org.cn number， ChiCTR2100044113］

ObjectiveTo evaluate the therapeutic effects of Huanglian Jiedutang on cerebral infarction injury in a mouse model of middle cerebral artery occlusion （MCAO） and to explore its mechanism of action on oligodendrocytes， particularly its potential in myelin repair. MethodsMultiple experimental approaches were used to evaluate cerebral ischemic injury and the effects of drug intervention. Laser speckle imaging was used to detect changes in cerebral blood flow， 2，3，5-Triphenyltetrazolium chloride （TTC） staining was used to measure infarct volume， and neurological function was scored according to the Zea-Longa criteria. Brain tissues were routinely embedded in paraffin and subjected to HE and Nissl staining to observe tissue structure and neuronal damage. Animals were divided into a sham group （n=24）， model group （n=24）， Huanglian Jiedutang group （n=24）， and Ginkgo biloba extract （GBE） group （n=18）. After 1 week of acclimatization， intragastric administration was initiated. The sham and model groups received normal saline， the Huanglian Jiedutang group was administered 1.82 g·kg^-1， and the GBE group was administered 0.432 g·kg^-1 after preparation as a 2.16 g·L^-1 solution. All groups were treated for 5 consecutive days at a dose of 0.2 mL·（10 g）^-¹·d^-¹. The MCAO model was established after the final administration on day 6. Single-cell RNA sequencing was used to analyze brain tissue cellular composition and changes in oligodendrocyte subpopulations. Distinct subpopulations were identified by Uniform manifold approximation and projection （UMAP） dimensionality reduction and unsupervised clustering， and marker gene expression was analyzed. Pathway enrichment and causal inference were further performed using IPA. Finally， real-time quantitative PCR was used to verify mRNA expression changes of myelin-related genes. ResultsCompared with the sham group， the model group showed significantly increased neurological function scores （P<0.01）， significantly impaired blood flow （P<0.01）， significantly enlarged cerebral infarct area （P<0.01）， and pathological changes including disordered cortical structural arrangement， aggravated cytoplasmic vacuolization， and increased Nissl bodies. Compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly decreased neurological function scores （P<0.01）， markedly restored blood flow levels （P<0.01）， significantly reduced cerebral infarct area （P<0.01）， and improvement in cortical structural disorder， alleviation of cytoplasmic vacuolization， and a reduction in Nissl bodies. Single-cell data showed that a myelin-associated oligodendrocyte （Mye-OL） subpopulation existed among oligodendrocytes， which was closely related to myelin generation. Compared with the sham group， the number of Mye-OL cells decreased in the model group. Compared with the model group， the number of Mye-OL cells increased in the Huanglian Jiedutang group. This subpopulation promoted the expression of myelin-related genes， including MOG， MBP， and MAG， via transcription factors such as OLIG1， OLIG2， NKX2-2， and SOX10， thereby regulating myelin generation， restoring cognition， and exerting therapeutic effects on acute cerebral infarction. Compared with the sham group， the mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 were significantly downregulated in the model group （P<0.01）， and the mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG， were also significantly downregulated （P<0.01）. In contrast， compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly upregulated mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 （P<0.01）， and significantly upregulated mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG （P<0.01）. ConclusionHuanglian Jiedutang exerts therapeutic effects on acute cerebral infarction by regulating the OLIG1/2-NKX2-2-SOX10 signaling pathway to promote myelin generation by Mye-OL cells.

Objective·To investigate the effects of liraglutide on liver fibrosis in mice with non-alcoholic fatty liver disease(NAFLD)and the underlying mechanisms.Methods·Twenty 8-week-old C57BL/6J mice were randomly divided into a normal chow diet group(Chow group)and a methionine-choline-deficient(MCD)diet group(MCD group),with 10 mice per group.The MCD diet was used to induce NAFLD.Each group was further divided into two subgroups,resulting in four subgroups:Chow+saline,Chow+liraglutide,MCD+saline,and MCD+liraglutide group.After daily intraperitoneal injection of liraglutide(400 μg/kg)or an equivalent volume of saline for 4 weeks,an intraperitoneal glucose tolerance test(IPGTT)was performed.Serum levels of aspartate transaminase(AST),alanine aminotransferase(ALT),total cholesterol(TC),triglyceride(TAG),high-density lipoprotein cholesterol(HDL-C),and low-density lipoprotein cholesterol(LDL-C)were measured.Liver tissues were collected post-euthanasia to assess TAG content.Histopathological changes,lipid deposition,and fibrosis were evaluated via hematoxylin-eosin(HE)staining,Oil Red O staining,and Masson staining.Real-time quantitative PCR(qPCR)and Western blotting were used to analyze the expression of α-smooth muscle actin(α-SMA),fibronectin(FN),collagen type Ⅰ α(COL1A),matrix metalloproteinase 9(MMP9),tissue inhibitor of metalloproteinase 1(TIMP1),transforming growth factor β(TGF-β),SMAD3,and phosphorylated SMAD3(pSMAD3).Results·The IPGTT revealed that liraglutide intervention reduced blood glucose levels at 15,30,and 60 min,with a decreased area under the curve(AUC)(both P<0.05).Biochemical analysis showed that liraglutide lowered AST and ALT levels(both P<0.001),increased TC and HDL-C levels(both P<0.05),but had no significant effect on TAG or LDL-C in MCD mice.HE staining and Oil Red O staining revealed reduced lipid droplets,ballooning degeneration,and inflammatory infiltration in hepatocytes after liraglutide treatment.Masson staining indicated decreased collagen fiber deposition in the liver.qPCR and Western blotting analysis demonstrated upregulated expression of α-SMA,FN,COL1A,TIMP1,TGF-β,and pSMAD3/SMAD3,alongside downregulated MMP9 in MCD mice.Liraglutide reversed these changes,lowering α-SMA,FN,COL1A,TIMP1,TGF-β,and pSMAD3/SMAD3 expression while increasing MMP9 expression.Conclusion·Liraglutide ameliorates liver injury,lipid deposition,and fibrosis in NAFLD mice,through modulation of the TGF-β/SMAD3 pathway and regulating fibrosis-associated protein expression.

Objective: There were associations between emotional abuse and neglect (EAN) and depression, but few studies had tested potential mechanisms underlying these relationships. We aimed to provide insights on how (the mediation role of neuroticism), and under what conditions (the moderator role of psychological resilience), led to a higher level of depression. Methods: This study was a cross-sectional study that used a random cluster sampling method. We randomly selected 3,993 participants from four junior middle schools in northern city of China. Participants were asked to complete four self-reported questionnaires, including the Childhood Trauma Questionnaire, Children Depression Inventory-Short Form, Chinese Big Five Personality Inventory Brief Version, and Chinese Resilience Scale. Results: The results showed that neuroticism mediated the associations between EAN and depression. In addition, the mediating effect of neuroticism was moderated by psychological resilience (p<0.05). Conclusion EAN and neuroticism could have an adverse impact on depression, and psychological resilience could alleviate these negative effects as a moderator. Our model suggested psychological resilience could be a particularly effective intervention point for victims of EAN.

Objective:To explore the correlation between serum ferritin (SF) and risk of lean non-alcoholic fatty liver disease (NAFLD), so as to provide the basis for the prevention and treatment of lean NAFLD.Methods:A total of 7 187 people without NAFLD at baseline who took at least 2 physical examinations in the Health Management Center of the Second Hospital of Dalian Medical University from January 2014 to December 2023 and met the selection criteria were selected as the research subjects, and all the subjects had no NAFLD at baseline. Subjects were divided into four groups according to baseline SF quartiles: 1 797 cases in the first quartile ( Q1) group, 1 797 cases in the second quartile ( Q2) group, 1 797 cases in the third quartile ( Q3) group, and 1 796 cases in the fourth quartile ( Q4) group. The incidence of lean NAFLD in each group were observed. Kaplan-Meier curve was plotted to calculate the cumulative incidence of lean NAFLD which compared by log-rank test. Cox proportional hazard regression model was used to analyze the correlation between SF and new-onset lean NAFLD, Q1, Q2, Q3 and Q4 of SF were taken as continuous variables into the model for trend test.The stability of the results was verified by two item sensitivity analyses. Time-dependent receiver operating characteristic curve (ROC) was plotted to evaluate the predictive value of SF for the onset of lean NAFLD. Results:The cumulative follow-up were 25 076 person-years. There were 230 new cases of lean NAFLD, and the incidence density was 9.172/1 000 person-years. The incidence densities of lean NAFLD in Q1, Q2, Q3 and Q4 groups were 6.915/1 000 person-years, 8.552/1 000 person-years, 9.641/1 000 person-years, 12.003/1 000 person-years, respectively. Kaplan-Meier curve indicated that the incidence of lean NAFLD was increased with the increment of SF, and the difference was statistically significant (log-rank test, χ2=9.92, P=0.019). Cox proportional hazard regression model results showed that the risk of developing lean NAFLD in Q4 group increased by 72.8% ( HR=1.728, 95% confidence interval (95% CI): 1.059 to 2.820) compared with Q1 group. Trend analysis revealed that the risk of lean NAFLD increased by 18.9% for each one-quartile increase of SF( HR=1.189, 95% CI: 1.012 to 1.396). Two sensitivity analyses indicated that the risk of NAFLD in Q4 group was 1.795 times ( HR=1.795, 95% CI: 1.083 to 2.975) or 1.654 times ( HR=1.654, 95% CI: 1.022 to 2.678) higher than that in Q1 group. The area under the curve (95% CI) of SF for predicting the incidence of lean NAFLD at 2-, 3-, 7- and 8-year follow-up based on time-dependent ROC were 0.645 (0.593 to 0.698), 0.652 (0.603 to 0.700), 0.605 (0.539 to 0.672) and 0.716 (0.597 to 0.836), respectively. Conclusion:SF is an independent risk factor for lean NAFLD and has predictive value for the new-onset of lean NAFLD.

Objective·To investigate the effects of liraglutide on liver fibrosis in mice with non-alcoholic fatty liver disease(NAFLD)and the underlying mechanisms.Methods·Twenty 8-week-old C57BL/6J mice were randomly divided into a normal chow diet group(Chow group)and a methionine-choline-deficient(MCD)diet group(MCD group),with 10 mice per group.The MCD diet was used to induce NAFLD.Each group was further divided into two subgroups,resulting in four subgroups:Chow+saline,Chow+liraglutide,MCD+saline,and MCD+liraglutide group.After daily intraperitoneal injection of liraglutide(400 μg/kg)or an equivalent volume of saline for 4 weeks,an intraperitoneal glucose tolerance test(IPGTT)was performed.Serum levels of aspartate transaminase(AST),alanine aminotransferase(ALT),total cholesterol(TC),triglyceride(TAG),high-density lipoprotein cholesterol(HDL-C),and low-density lipoprotein cholesterol(LDL-C)were measured.Liver tissues were collected post-euthanasia to assess TAG content.Histopathological changes,lipid deposition,and fibrosis were evaluated via hematoxylin-eosin(HE)staining,Oil Red O staining,and Masson staining.Real-time quantitative PCR(qPCR)and Western blotting were used to analyze the expression of α-smooth muscle actin(α-SMA),fibronectin(FN),collagen type Ⅰ α(COL1A),matrix metalloproteinase 9(MMP9),tissue inhibitor of metalloproteinase 1(TIMP1),transforming growth factor β(TGF-β),SMAD3,and phosphorylated SMAD3(pSMAD3).Results·The IPGTT revealed that liraglutide intervention reduced blood glucose levels at 15,30,and 60 min,with a decreased area under the curve(AUC)(both P<0.05).Biochemical analysis showed that liraglutide lowered AST and ALT levels(both P<0.001),increased TC and HDL-C levels(both P<0.05),but had no significant effect on TAG or LDL-C in MCD mice.HE staining and Oil Red O staining revealed reduced lipid droplets,ballooning degeneration,and inflammatory infiltration in hepatocytes after liraglutide treatment.Masson staining indicated decreased collagen fiber deposition in the liver.qPCR and Western blotting analysis demonstrated upregulated expression of α-SMA,FN,COL1A,TIMP1,TGF-β,and pSMAD3/SMAD3,alongside downregulated MMP9 in MCD mice.Liraglutide reversed these changes,lowering α-SMA,FN,COL1A,TIMP1,TGF-β,and pSMAD3/SMAD3 expression while increasing MMP9 expression.Conclusion·Liraglutide ameliorates liver injury,lipid deposition,and fibrosis in NAFLD mice,through modulation of the TGF-β/SMAD3 pathway and regulating fibrosis-associated protein expression.

Objective To explore the objective characteristics of tongue in primary immune thrombocytopenia(ITP);To provide references for accurate syndrome differentiation.Methods Totally 112 patients with ITP were divided into groups according to their platelet count,TCM symptoms and drug treatment lines.Infrared thermal imager,hygrometer,colorimetry and image analysis software were used to detect the temperature,humidity,colorimetry and morphology of tongue body(TB),tongue coating(TC)and sublingual vessel(SV),and analyze their characteristics.The tongue was divided into five areas:tip of tongue(T),middle of tongue(M),behind of tongue(B),middle left of tongue(ML)and middle right of tongue(MR),and its temperature was measured.Humility(H)of tongue and tongue coating were measured by hygrometer.The images of tongue body,tongue coating and sublingual collaterals were taken,and the chromaticity indexes of R,G,B,L,a,b were analyzed by Adobe Photoshop 2023.The width,length and tortuosity of sublingual collaterals were under morphological analysis.Results ① Comparison of platelet count groups:compared with 30-50 platelet count group and more than 100 platelet count group,the TB-R of 51-100 platelet count group decreased(P<0.05,P<0.01),and compared with 30-50 platelet count group,the TB-a of 51-100 platelet count group decreased(P<0.01);compared with platelet<30 group and platelet 30-50 group,the TC-H of platelet>100 group increased(P<0.05,P<0.01);compared with platelet>100 group,the length of sublingual collaterals in platelet<30 group was longer(P<0.05).② Comparison of different TCM symptom groups:compared with the bleeding group and asymptomatic group,the M and SV-B in the fatigue group decreased(P<0.05,P<0.01);compared with the asymptomatic group,the TC-b in the anxious group was significantly higher(P<0.05).③ Comparison of administration groups:compared with the Danazol group and Chinese materia medica group,the TC-H in the glucocorticoid group was significantly higher(P<0.05,P<0.01).Conclusion There are differences in tongue characteristic indexes among ITP patients with different platelet counts,TCM symptoms and drug treatment lines,which can measure of tongue indexes to provide references for accurate syndrome differentiation of ITP.

Objective:To explore the correlation between serum ferritin (SF) and risk of lean non-alcoholic fatty liver disease (NAFLD), so as to provide the basis for the prevention and treatment of lean NAFLD.Methods:A total of 7 187 people without NAFLD at baseline who took at least 2 physical examinations in the Health Management Center of the Second Hospital of Dalian Medical University from January 2014 to December 2023 and met the selection criteria were selected as the research subjects, and all the subjects had no NAFLD at baseline. Subjects were divided into four groups according to baseline SF quartiles: 1 797 cases in the first quartile ( Q1) group, 1 797 cases in the second quartile ( Q2) group, 1 797 cases in the third quartile ( Q3) group, and 1 796 cases in the fourth quartile ( Q4) group. The incidence of lean NAFLD in each group were observed. Kaplan-Meier curve was plotted to calculate the cumulative incidence of lean NAFLD which compared by log-rank test. Cox proportional hazard regression model was used to analyze the correlation between SF and new-onset lean NAFLD, Q1, Q2, Q3 and Q4 of SF were taken as continuous variables into the model for trend test.The stability of the results was verified by two item sensitivity analyses. Time-dependent receiver operating characteristic curve (ROC) was plotted to evaluate the predictive value of SF for the onset of lean NAFLD. Results:The cumulative follow-up were 25 076 person-years. There were 230 new cases of lean NAFLD, and the incidence density was 9.172/1 000 person-years. The incidence densities of lean NAFLD in Q1, Q2, Q3 and Q4 groups were 6.915/1 000 person-years, 8.552/1 000 person-years, 9.641/1 000 person-years, 12.003/1 000 person-years, respectively. Kaplan-Meier curve indicated that the incidence of lean NAFLD was increased with the increment of SF, and the difference was statistically significant (log-rank test, χ2=9.92, P=0.019). Cox proportional hazard regression model results showed that the risk of developing lean NAFLD in Q4 group increased by 72.8% ( HR=1.728, 95% confidence interval (95% CI): 1.059 to 2.820) compared with Q1 group. Trend analysis revealed that the risk of lean NAFLD increased by 18.9% for each one-quartile increase of SF( HR=1.189, 95% CI: 1.012 to 1.396). Two sensitivity analyses indicated that the risk of NAFLD in Q4 group was 1.795 times ( HR=1.795, 95% CI: 1.083 to 2.975) or 1.654 times ( HR=1.654, 95% CI: 1.022 to 2.678) higher than that in Q1 group. The area under the curve (95% CI) of SF for predicting the incidence of lean NAFLD at 2-, 3-, 7- and 8-year follow-up based on time-dependent ROC were 0.645 (0.593 to 0.698), 0.652 (0.603 to 0.700), 0.605 (0.539 to 0.672) and 0.716 (0.597 to 0.836), respectively. Conclusion:SF is an independent risk factor for lean NAFLD and has predictive value for the new-onset of lean NAFLD.

Objective:To investigate transition pattern of health status among middle-aged and elderly population in China based on frailty index.Methods:In this retrospective cohort study, middle-aged and elderly people were selected from the China Health and Retirement Longitudinal Study (CHARLS) in 2011; and 1 434 subjects were followed up to 2015. The frailty index was calculated from the prevalence of chronic diseases, daily activity ability and blood biomarkers, and the frailty state was divided by quartiles of the frailty index. Markov models were constructed to determine the transition probabilities of different frailty states.Results:The mean age of the 1 434 subjects was (59.0±9.4) years and the mean frailty index was 0.11±0.05. In the healthy individuals, 63.0% remained healthy after a four-year follow-up; during the same follow-up period, 40.9% of the mildly frail individuals and 23.0% of the moderately frail individuals remained in their baseline frailty status. Increasing age leaded to a gradual increase in the probability of the population shifting to a severely frailty state. Women were more likely to shift to severe frailty status than men (0.029 vs 0.019, Z=3.03, P=0.002). Conclusion:Among middle-aged and elderly population in China, the transition of health states follows a pattern where higher frailty levels are associated with lower stability. Advanced age and female gender are identified as risk factors for progression to severe frailty.