ObjectiveTo analyze the metabolomic characteristics of platelets in fibrinogen（FIB） overexpression rats of coronary heart disease with blood stasis syndrome（CHD-BSS）， explore potential biomarkers， and investigate the mechanism of FIB overexpression on CHD-BSS. MethodsSD rats were randomly divided into BSS group and BSS+FIB overexpression group（BSS+FIB group）， with 10 rats in each group. Both the BSS+FIB group and the BSS group were fed a high-fat diet combined with oral administration of vitamin D₃ and subcutaneous injection of isoproterenol， but rats in the BSS+FIB group were overexpressed with FIB during the initial modeling stage by transfection with adeno-associated virus（AAV）. The overexpression level of FIB in rat liver and plasma samples was detected by enzyme-linked immunosorbent assay（ELISA） and real-time fluorescence quantitative polymerase chain reaction（Real time PCR）， as well as the expression level of liver FIB A（FGA） mRNA. The characteristics of metabolites in rat platelet samples were analyzed by ultra-high performance liquid chromatography-quadrupole-electrostatic field orbital trap high-resolution mass spectrometry（UPLC-Q-Exactive Orbitrap-MS）， and the differential metabolites between groups were screened by principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA）， and the enriched pathways were analyzed. The accuracy of potential biomarkers in the diagnosis of CHD-BSS was evaluated by receiver operating characteristic（ROC） curve. The expression of autophagy related proteins phosphorylated adenosine monophosphate（AMP） activated protein kinase（p-AMPK）/AMPK， phosphorylated mammalian target of rapamycin（p-mTOR）/mTOR， microtubule-associated protein 1 light chain 3（LC3） Ⅱ/Ⅰ and p62 in platelets were detected by Western blot. ResultsCompared with the BSS group， the expression levels of FIB in liver and plasma samples of the BSS+FIB group were significantly increased（P<0.05， P<0.01）， and the expression level of FIB mRNA in the liver was remarkably increased（P<0.01）， indicating successful overexpression of FIB. Platelet metabolomics results showed significant differences in metabolic profiles between the BSS+FIB group and the BSS group， and a total of 25 significantly enriched metabolic pathways and 8 metabolites involved in these metabolic pathways， among which uric acid， guanosine and ribose 1-phosphate levels were up-regulated， while adenosine diphosphate（ADP）， AMP， guanosine diphosphate（GDP）， adenylosuccinate and norepinephrine levels were down-regulated. The diagnostic ability analysis of differential metabolites showed that all 8 differential metabolites had good diagnostic ability， with an area under the curve（AUC）>0.85. Western blot results showed that compared with the BSS group， the expression levels of p-mTOR/mTOR and p62 proteins in platelets of the BSS+FIB group was significantly reduced（P<0.01）， while the expression levels of p-AMPK/AMPK and LC3Ⅱ/Ⅰ proteins were increased， but the difference was not statistically significant. ConclusionOverexpression of FIB can change the metabolic characteristics of CHD-BSS rat model， involving multiple aspects such as vascular endothelial injury， platelet activation and myocardial function damage. Among them， overexpression of FIB may enhance the occurrence of platelet autophagy， thereby inducing platelet activation and promoting thrombus formation.

ObjectiveTo investigate the effect of 1，25（OH）₂D₃ on the level of peroxisome proliferator-activated receptor-γ （PPAR-γ） in the liver， the phenotype of hepatic macrophages， and liver inflammation in a rat model of nonalcoholic steatohepatitis （NASH）， as well as the mechanism of 1，25（OH）₂D₃ improving liver inflammation. MethodsAfter 1 week of adaptive feeding， 24 specific pathogen-free Wistar rats were randomly divided into normal group ［choline-supplemented L-amino acid-defined （CSAA） diet］， normal+1，25（OH）₂D₃ group ［CSAA diet+1，25（OH）₂D₃］， model group ［choline-deficient L-amino acid-defined diet （CDAA） diet］， and model+1，25（OH）₂D₃ group ［CDAA diet+1，25（OH）₂D₃］， with 6 rats in each group. The dose of 1，25（OH）₂D₃ was 5 μg/kg for intraperitoneal injection twice a week for 12 weeks. The serum levels of aspartate aminotransferase （AST） and alanine aminotransferase （ALT） were measured， liver histopathology was observed， and SAF score was assessed. M1 hepatic macrophages and M2 hepatic macrophages were measured to analyze in the change in the phenotype of hepatic macrophages， and ELISA was used to measure the levels of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， interleukin-4 （IL-4）， and interleukin-10 （IL-10） in liver tissue， and qPCR was used to measure the mRNA level of PPAR-γ. The two-factor analysis of variance was use for comparison between groups， and the least significant difference t-test was used for further comparison； the Pearson method was used for correlation analysis. ResultsCompared with the normal group， the model rats with CDAA diet-induced NASH had significant increases in the serum levels of AST and ALT （P=0.019 and P<0.001）， the SAF score of liver histopathology （P<0.001）， the level of M1 hepatic macrophages （P<0.001）， and the ratio of M1 and M2 hepatic macrophages （P<0.001）， as well as a significant increase in the level of TNF-α （P<0.001） and a significant reduction in the level of IL-4 in liver tissue （P=0.025）. The 1，25（OH）₂D₃ group had significant reductions in the serum levels of ALT （P<0.001）， the SAF score of liver histopathology （P<0.001）， the level of M1 hepatic macrophages （P<0.001）， and the ratio of M1 and M2 hepatic macrophages （P=0.001）， the level of IL-1β （P<0.001） and a significant increase in the level of M2 hepatic macrophages （P=0.017）， the level of IL-10 （P=0.039）， the level of IL-4 （P<0.001）， the level of PPAR-γ （P=0.016）. There were significant interactions between CDAA diet-induced NASH model and 1，25（OH）₂D₃ in serum the levels of AST and ALT （P=0.007 and P=0.008）， the SAF scores of liver histopathology （P<0.001）， the level of M1 hepatic macrophages （P<0.001）， the level of M2 hepatic macrophages （P=0.008）， the ratio of M1 and M2 of hepatic macrophages （P=0.005）， the level of TNF-α （P<0.001）， the level of IL-10 （P=0.038）， the level of IL-4 （P<0.001） and the level of PPAR-γ （P=0.009）. The correlation analysis showed that PPAR-γ was negatively correlated with the ratio of M1 and M2 hepatic macrophages （r=-0.415， P=0.044） and was positively correlated with M2 hepatic macrophages （r=0.435， P=0.033）， IL-10 （r=0.433， P=0.035）， and IL-4 （r=0.532， P=0.007）. ConclusionThis study shows that 1，25（OH）₂D₃ improves liver inflammation in NASH by activating PPAR-γ to regulate the phenotypic transformation of hepatic macrophages.

Purpose: The aim of this study was to investigate the feasibility of an intelligent handheld ultrasound (US) device for assisting non-expert general practitioners (GPs) in detecting carotid plaques (CPs) in community populations. Methods: This prospective parallel controlled trial recruited 111 consecutive community residents. All of them underwent examinations by non-expert GPs and specialist doctors using handheld US devices (setting A, setting B, and setting C). The results of setting C with specialist doctors were considered the gold standard. Carotid intima-media thickness (CIMT) and the features of CPs were measured and recorded. The diagnostic performance of GPs in distinguishing CPs was evaluated using a receiver operating characteristic curve. Inter-observer agreement was compared using the intragroup correlation coefficient (ICC). Questionnaires were completed to evaluate clinical benefits. Results: Among the 111 community residents, 80, 96, and 112 CPs were detected in settings A, B, and C, respectively. Setting B exhibited better diagnostic performance than setting A for detecting CPs (area under the curve, 0.856 vs. 0.749; P<0.01). Setting B had better consistency with setting C than setting A in CIMT measurement and the assessment of CPs (ICC, 0.731 to 0.923). Moreover, measurements in setting B required less time than the other two settings (44.59 seconds vs. 108.87 seconds vs. 126.13 seconds, both P<0.01). Conclusion Using an intelligent handheld US device, GPs can perform CP screening and achieve a diagnostic capability comparable to that of specialist doctors.

ObjectiveTo investigate the mechanism by which modified Shengjiangsan （MSJS） improves diabetic kidney disease （DKD） by activating mitochondrial autophagy. MethodsSixty SPF-grade male Sprague-Dawley rats aged 7-8 weeks were selected. A DKD model was established using a high-sugar， high-fat diet combined with intraperitoneal injection of streptozotocin （STZ）. After successful modeling， the rats were randomly divided into six groups： a normal control group， a model group， low-， medium-， and high-dose MSJS groups （7.7， 15.4， 30.8 g·kg^-1， respectively）， and an irbesartan group （0.384 g·kg^-1）. Each group received either normal saline or the corresponding drug by gavage once daily for 28 consecutive days. Blood glucose， body weight， and kidney weight were recorded. Serum creatinine （SCr） and blood urea nitrogen （BUN） levels were detected using an automatic blood analyzer. Enzyme-linked immunosorbent assay （ELISA） was used to determine urinary microalbumin （mALB）， and serum levels of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-6 （IL-6）. Histopathological changes in renal tissues were observed using hematoxylin-eosin （HE） staining， periodic acid-Schiff （PAS） staining， and transmission electron microscopy （TEM）. The expression levels of mitochondrial autophagy-related proteins in renal tissues were analyzed by Western blot. Immunofluorescence co-localization was employed to detect the co-expression of microtubule-associated protein 1 light chain 3 beta （LC3B） and cytochrome c oxidase subunit Ⅳ （COX Ⅳ）. ResultsCompared with the normal control group， the model group exhibited significant increases in renal index， blood glucose， and 24-hour urinary microalbumin （24 h mALB） （P<0.05， P<0.01）. The levels of serum SCr and BUN were significantly elevated （P<0.01）， and the serum levels of TNF-α， IL-1β， and IL-6 were markedly upregulated （P<0.01）. Histopathological examination revealed glomerular hypertrophy， mesangial expansion and increased deposition， podocyte foot process flattening and fusion， a decreased number of autophagosomes accompanied by mitochondrial swelling， vacuolar degeneration of renal tubular epithelial cells， and inflammatory cell infiltration in the renal interstitium. The expression levels of autophagy-related proteins LC3B， PTEN-induced putative kinase 1 （PINK1）， and E3 ubiquitin-protein ligase （Parkin） were significantly decreased （P<0.05， P<0.01）， while expression of the selective autophagy adaptor protein p62 was significantly increased （P<0.01）. Immunofluorescence signal intensity and LC3B-COX Ⅳ co-expression were both diminished. Compared with the model group， the MSJS treatment groups and the irbesartan group showed significant reductions in renal index， blood glucose， and 24 h mALB （P<0.05， P<0.01）. The serum SCr and BUN levels decreased significantly （P<0.05） and TNF-α， IL-1β， and IL-6 levels were significantly downregulated （P<0.05， P<0.01）. Histopathological damage was alleviated， including reduced glomerular hypertrophy， decreased mesangial deposition， and attenuated podocyte foot process fusion. The number of autophagosomes increased， and mitochondrial swelling was improved. The expression levels of LC3B， PINK1， and Parkin in renal tissues were significantly upregulated， whereas p62 expression was significantly downregulated （P<0.05， P<0.01） in MSJS groups. Immunofluorescence signal intensity was enhanced， and LC3B-COX Ⅳ co-expression was increased. ConclusionMSJS alleviates the inflammatory response in DKD rats and exerts renal protective effects by regulating the PINK1/Parkin signaling pathway and activating mitochondrial autophagy.

Objective: To classify the ABO blood group phenotypes of 5 cases from a family, and to explore the molecular mechanism for reduced B antigen expression in ABO blood group system. Methods: Serological identification of the ABO blood group was performed using microcolumn gel assay and saline tube method. The soluble antigens in saliva were detected by the agglutination inhibition assay. The full-length sequences and upstream promoter regions of ABO gene were sequenced for genotyping using PacBio SMRT sequencing technology. Results: The results of serological tests indicated the expression of B antigen decreased in 3 out of 5 blood samples. A mixed-field agglutination was observed with anti-B antibody. B antigen was not detected in all 5 saliva samples. The ABO genotype for all samples were ABO B.01/ABO O.01.02, and a novel mutation c. 28+5875C>T within the DNA-binding region of RUNX1 in +5.8-kb site were found in the B allele for 3 samples with reduced expression of B antigen. Conclusion: Results of serological and genetic analyses classify the 3 cases with reduced B antigen expression as B phenotype. The novel mutation c. 28+5875C>T of RUNX1 could be the key reason for reduced B antigen expression in 3 cases with B phenotype.

Objective: To investigate the nutritional status and influencing factors among Tibetan and Mongolian children and adolescents aged 7-18 years in high-altitude regions, so as to provide evidence for early prevention and control of malnutrition in this population. Methods: From May to June 2022, a cluster sampling method was employed to recruit 1 019 Tibetan and Mongolian children and adolescents aged 7-18 years from two primary and secondary schools in Golmud City. Physical examinations, dietary frequency questionnaires, and physical activity assessments were conducted. Nutritional status was classified as obesity, combined overweight/obesity, underweight, or central obesity according to national standards including Screening for Overweight and Obesity among School-age Children and Adolescents, Screening Standard for Malnutrition of School-age Children and Adolescents, Blue Book on Obesity Prevention and Control in China. Chi-square tests, t-test and Logistic regression analyses were performed to identify factors associated with different nutritional statuses. Results: The detection rates of obesity, combined overweight/obesity, underweight, and central obesity were 8.0%, 18.1%, 5.2%, and 19.7%, respectively. The height of children and adolescents across all age groups was generally lower than the national standard values. Tibetan participants exhibited significantly lower height-for-age Z-scores (HAZ)(9-10, 13-17 years, Z =2.01, 2.78, 4.16, 3.38, 4.12, 3.63, 3.00) and BMI-for-age Z-scores (BAZ) compared to Mongolian participants ( Z =-2.95, -2.47, -2.31, -2.89, -2.14, -2.17)( P < 0.05 ). Multivariate Logistic regression revealed that Mongolian children and adolescents had higher risks of obesity ( OR =2.20) and combined overweight/obesity ( OR = 2.18 ) ( P <0.05). Additionally, insufficient moderate-to-vigorous physical activity (MVPA) was associated with an increased risk of central obesity ( OR =1.48, P <0.05), compared with children and adolescents who meet the standard of MVPA. Conclusions The rates of overweight and obesity among Tibetan and Mongolian children and adolescents in Golmud City are higher, influenced by multiple factors. Nutrition interventions and physical activity strategies tailored to ethnic characteristics should be implemented, with emphasis on promoting MVPA to improve nutritional outcomes in this population.

ObjectiveTo elucidate the critical role of rehabilitation medical records (including electronic records) in rehabilitation medicine's clinical practice and management, comprehensively analyzed the structure, core content and data standards of rehabilitation medical records, to develop a standardized medical record data architecture and core dataset suitable for rehabilitation medicine and to explore the application of rehabilitation data in performance evaluation and payment. MethodsBased on the regulatory documents Basic Specifications for Medical Record Writing and Basic Specifications for Electronic Medical Records (Trial) issued by National Health Commission of China, and referencing the World Health Organization (WHO) Family of International Classifications (WHO-FICs) classifications, International Classification of Diseases (ICD-10/ICD-11), International Classification of Functioning, Disability and Health (ICF), and International Classification of Health Interventions (ICHI Beta-3), this study constructed the data architecture, core content and data standards for rehabilitation medical records. Furthermore, it explored the application of rehabilitation record summary sheets (home page) data in rehabilitation medical statistics and payment methods, including Diagnosis-related Groups (DRG), Diagnosis-Intervention Packet (DIP) and Case Mix Index. ResultsThis study proposed a systematic standard framework for rehabilitation medical records, covering key components such as patient demographics, rehabilitation diagnosis, functional assessment, rehabilitation treatment prescriptions, progress evaluations and discharge summaries. The research analyzed the systematic application methods and data standards of ICD-10/ICD-11, ICF and ICHI Beta-3 in the fields of medical record terminology, coding and assessment. Constructing a standardized data structure and data standards for rehabilitation medical records can significantly improve the quality of data reporting based on the medical record summary sheet, thereby enhancing the quality control of rehabilitation services, effectively supporting the optimization of rehabilitation medical insurance payment mechanisms, and contributing to the establishment of rehabilitation medical performance evaluation and payment based on DRG and DIP. ConclusionStructured rehabilitation records and data standardization are crucial tools for quality control in rehabilitation. Systematically applying the three reference classifications of the WHO-FICs, and aligning with national medical record and electronic health record specifications, facilitate the development of a standardized rehabilitation record architecture and core dataset. Standardizing rehabilitation care pathways based on the ICF methodology, and developing ICF- and ICD-11-based rehabilitation assessment tools, auxiliary diagnostic and therapeutic systems, and supporting terminology and coding systems, can effectively enhance the quality of rehabilitation records and enable interoperability and sharing of rehabilitation data with other medical data, ultimately improving the quality and safety of rehabilitation services.

Neutrophil extracellular traps(NETs)are net-like complexes released by neutrophils and play a crucial role in antimicrobial defense. In addition, NETs can exacerbate inflammatory responses associated with various diseases, including diabetes, cardiovascular diseases, and autoimmune diseases. Currently, the role of NETs in ocular diseases has received extensive attention. This article systematically summarizes the formation mechanism of NETs and their role in maintaining intraocular homeostasis under physiological conditions. At the same time, it focuses on elaborating the pathogenic role of NETs in the field of ophthalmic diseases, such as dry eye, keratitis, uveitis, diabetic retinopathy, retinal vein occlusion, and age-related macular degeneration, emphasizing the importance of NETs as therapeutic targets for ocular diseases and the potential application value as new markers for ocular diseases. Future in-depth research on the mechanism of NETs in ocular diseases will provide a stronger theoretical basis for the treatment of related eye diseases.

ObjectiveTo study the effect and mechanism of fibrinogen （Fib） overexpression on mitochondrial quality control system in the rat model of coronary heart disease with the syndrome of blood stasis. MethodsForty male SD rats were randomly assigned into normal， model， Fib， and empty vector （AAV） groups， with 10 rats in each group. The model， Fib， and AAV groups were fed with a high-fat diet adaptively and administrated with 3×10⁶ U·kg^-1 vitamin D3 powder by gavage after 7 days and 2×10⁶ U·kg^-1 vitamin D3 solution after 14 days. After being fed with a high-fat diet for 7 weeks， rats in each group received subcutaneous injection of isoproterenol （5 mg·kg^-1） for 3 days. During the modeling period， rats in the normal group were fed with ordinary feed without any special treatment. The changes in blood lipid and hemorheological indexes of rats in each group were measured. The aorta tissue was stained with hematoxylin-eosin （HE）， and the standard lead Ⅱ electrocardiograms （ECGs） of rats in each group were recorded. Enzyme-linked immunosorbent assay （ELISA） and real-time PCR were employed to verify the overexpression levels of Fib in the liver and plasma. Western blotting was employed to determine the protein levels of mitofusin 2 （Mfn2）， optic atrophy protein 1 （OPA1）， dynamin-related protein 1 （Drp1）， phosphorylated adenosine monophosphate-activated protein kinase （p-AMPK）/adenosine monophosphate-activated protein kinase （AMPK）， peroxisome proliferator-activated receptor γ-coactivator-1α （PGC-1α）， PTEN-induced putative kinase 1， and Parkin. Real-time PCR was employed to determine the mRNA levels of AMPK and PGC-1α in the myocardial tissue. The changes in levels of adenosine triphosphate （ATP） and adenosine monophosphate （AMP） in the myocardial tissue were determined by ELISA. ResultsCompared with the normal group， the other three groups showed elevated levels of total cholesterol and low-density lipoprotein cholesterol （P<0.01） and no significant changes in levels of triglyceride and high-density lipoprotein cholesterol. Compared with the model group， the Fib and AAV groups showed risen levels of total cholesterol （P<0.05， P<0.01）. Compared with the normal group， the model and Fib groups presented increases in low shear viscosity and middle shear viscosity （P<0.05， P<0.01）， and the Fib group showcased an increase in high shear viscosity （P<0.01）. Compared with the model group， the Fib group showed increases in low shear viscosity， middle shear viscosity， and high shear viscosity （P<0.05， P<0.01）. Compared with the Fib group， the AAV group demonstrated decreases in low shear viscosity， middle shear viscosity， and high shear viscosity （P<0.05， P<0.01）. The normal group had an complete aortic structure with well arrangement of elastic fibers. In the model group， the vascular wall became thickened and the intima was rough with inflammatory infiltration. In the Fib group， the intima calcification formed a cavity structure and the intima was abnormally proliferated， while in the AAV group， the intima smooth muscle was slightly proliferated with local calcification. The ECG of the normal group indicated sinus rhythm， and that of the model group presented ST segment oblique elevation （>0.1 mV）. The ECG of the Fib group presented characteristic ST segment arch back elevation with T-wave towering， and that of the AAV group presented ST segment oblique elevation. Compared with the normal group， the model and Fib groups showed elevations in levels of liver Fib， plasma Fib， and liver Fibα mRNA （P<0.01）， and the AAV group had risen levels of Fib and Fibα mRNA （P<0.01）. Compared with the model group， the Fib group presented risen levels of liver Fib and Fibα mRNA （P<0.01）. Compared with the Fib group， the AAV group presented decreases in levels of liver Fib， plasma Fib， and liver Fibα mRNA （P<0.01）. Compared with the normal group， the other three groups had down-regulated protein and mRNA levels of Mfn2， OPA1， PINK1， Parkin， p-AMPK/AMPK， and PGC-1α （P<0.05， P<0.01） and up-regulated protein levels of Drp1 （P<0.01）. Compared with those in the model group， the mRNA and protein levels of Mfn2， OPA1， PINK1， Parkin， p-AMPK/AMPK， and PGC-1α were all down-regulated （P<0.05， P<0.01） and the protein level of Drp1 was up-regulated （P<0.01） in the Fib group. Compared with the Fib group， the AAV group showed differences in protein levels of OPA1， PGC-1α， Parkin， and Drp1 （P<0.05， P<0.01） and an increasing trend in the mRNA levels of AMPK and PGC-1α with no significant difference. Compared with the normal group， the other three groups had elevated levels of ATP in the myocardial tissue （P<0.01）. Compared with the model group， the Fib group showed elevated levels of ATP and AMP （P<0.01）. Compared with the Fib group， the AAV group exhibited lowered levels of ATP and AMP （P<0.01）. ConclusionFib can achieve the overexpression effect in the rat model of coronary heart disease with the syndrome of blood stasis. At the same time， the overexpression of Fib can induce the damage of the mitochondrial quality control system in the myocardial tissue， inhibit mitochondrial dynamics and mitochondrial biosynthesis， and down-regulate mitochondrial autophagy， thereby aggravating myocardial injury in the rat model.

ObjectiveTo explore the clinical safety of Feilike Mixture （FLK） in the real world. MethodsThe safety of all children who received FLK from 29 institutions in 12 provinces between January 21，2021 and December 25，2021 was evaluated through prospective centralized surveillance and a nested case control study. ResultsA total of 3 035 juveniles were included. There were 29 research centers involved，which are distributed across 12 provinces，including one traditional Chinese medicine （TCM） hospital and 28 general hospitals. The average age among the juveniles was （4.77±3.56） years old，and the average weight was （21.81±12.97） kg. Among them，119 cases （3.92%） of juveniles had a history of allergies. Acute bronchitis was the main diagnosis for juveniles，with 1 656 cases （54.46%）. FLK was first used in 2 016 cases （66.43%），and 142 juvenile patients had special dosages，accounting for 4.68%. Among them，92 adverse drug reactions （ADRs） occurred，including 73 cases of gastrointestinal system disorders，10 cases of metabolic and nutritional disorders，eight cases of skin and subcutaneous tissue diseases，two cases of vascular and lymphatic disorders，and one case of systemic diseases and various reactions at the administration site. The manifestations of ADRs were mainly diarrhea，stool discoloration，and vomiting，and no serious ADRs occurred. The results of multi-factor analysis indicated that special dosages （the use of FLK）［odds ratio （OR） of 2.642， 95% confidence interval （CI） of 1.105-6.323］，combined administration： spleen aminopeptide （OR of 4.978， 95%CI of 1.200-20.655），and reason for combined administration： anti-infection （OR of 1.814， 95%CI of 1.071-3.075） were the risk factors for ADRs caused by FLK. Conclusion92 ADRs occurred among 3 035 juveniles using FLK. The incidence of ADRs caused by FLK was 3.03%，and the severity was mainly mild or moderate. Generally，the prognosis was favorable after symptomatic treatment such as drug withdrawal or dosage reduction，suggesting that FLK has good clinical safety.